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3896245
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The effects of debrisoquin, administered daily for 4 days to rats (40 mg/kg, i.p.) and guinea pigs (4 mg/kg, i.p.), were determined for urinary excretion of several acidic and neutral amine metabolites, including the norepinephrine metabolites, 3-methoxy-4-hydroxyphenethylene glycol (MHPG) and vanillylmandelic acid (VMA), the dopamine metabolites, 3,4-dihydroxyphenethanol (DHPE), 3-methoxy-4-hydroxyphenethanol (MHPE), and homovanillic acid (HVA), and the octopamine metabolite, p-hydroxyphenylglycol (pHPG). The excretion of MHPG was reduced to 32% of control in rats and to 46% in guinea pigs, HVA was reduced to 64 and 80% in these two species, respectively, and MHPE was lowered to 59% of control in the rat but was not affected in the guinea pig. DHPE and pHPG were not altered significantly in either species. VMA was a minor metabolite in both species, being less than 6% of MHPG, and its formation was blocked only partially (rat) or not at all (guinea pig) by debrisoquin. The data refute the idea based on previous in vitro studies that VMA is a major metabolite of norepinephrine in the periphery of the guinea pig as it is in man.
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3896252
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The aim of this study was to determine whether the amount of LDL that had accumulated in the coronary arteries of cynomolgus monkeys during an 18-month period on a hypercholesterolemic (H) diet was reduced during subsequent periods of 6 and 12 months on a normolipemic (N) diet. This was performed by assessing the accumulation of LDL in the left anterior descending (LAD) branch of the left coronary artery within an area 4 mm from its origin, since this region contained the largest lesions in the LAD. LDL accumulation was estimated by measuring the percent cross-sectional area of artery occupied by reaction product depicting apo B by an immunoperoxidase procedure. The following reduction in mean (+/- SD) percent cross-sectional area occupied by reaction product was found in 8 animals on the progression diet (group I), 7 animals on the 6-month regression diet (group II), and 9 animals on the 12-month regression diet (group III), respectively: 21.7 +/- 4.7, 6.9 +/- 5.5, and 2.3 +/- 1.3. Differences between group I and either group II or III were statistically significant (using the Wilcoxon signed-ranks test). In group I, LDL was localized primarily in the necrotic core and around pools of foam cells. In groups II and III fewer foam cells and smaller pools of extracellular debris were qualitatively evident, and LDL was localized closer to the lumen and along collagen fibers. These results suggest that lowering of the plasma LDL level following termination of a hypercholesterolemic diet also induces a decrease in the LDL content in coronary artery lesions, even without significant reductions in lesion size, and that this decrease might be responsible for the decrease in foam cells.
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3896253
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An experimental review of the Feulgen and gallocyanine-chrome-alum stains for quantitative cytophotometry of DNA in tissue sections yielded information on the preparation and staining of tissue for quantitative absorbance microspectrophotometry. (1) Tissues routinely fixed in formalin are suitable for either stain. Specimens fixed with glutaraldehyde-containing fixatives are not satisfactory for Feulgen staining, nor are ethanol-fixed specimens, unless they are post-fixed in formalin. (2) The pararosaniline dyes, used in the Feulgen stain, are sufficiently pure to use if a solution of the dye in ethanol shows an absorbance peak at 543 to 546 nm. (3) The Feulgen stain provides good reproducibility when the staining solution is adjusted to pH 1.5. (4) Gallocyanine is the best stain to use on Bouin-fixed or glutaraldehyde-fixed tissues. (5) Where fixation is an option, Carnoy and methanol-formalin-glacial acetic acid are excellent fixatives that can be followed by either stain. (6) Selection of the thickness of a tissue section involves a compromise. Requirements of minimum nuclear overlap and sharp focusing favor a section thickness of 4 micron to 6 micron. On the other hand, the requirement for full nuclear thickness, as judged by absorbance equivalent to that of a touch preparation, demands sections as thick as 8 micron in the case of mouse liver. Within this range, the optimum thickness, therefore, is determined by the particular tissue, the range of its nuclear sizes and its packing density. (7) The refractive index of the mounting medium should be closely matched to that of the background structure of the tissue sections. For animal tissues, we found that media with refractive indices of 1.54 to 1.56 are suitable.
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3896254
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The nuclear DNA content in morphologically identified tumor cells was analyzed in 4-micron histologic sections from 58 patients with lung carcinoma who survived for at least five years. Thirty-three of the carcinomas were invasive squamous bronchial carcinomas and 25 were pulmonary adenocarcinomas. In all squamous carcinomas, the majority of tumor cells were found to exhibit DNA values exceeding the normal tetraploid and/or diploid region. In contrast, some of the pulmonary adenocarcinomas were found to be composed of a majority of tumor cells with DNA values in the normal diploid region. The results indicate that invasive squamous bronchial carcinomas, in general, are tumors with aneuploid DNA patterns indicative of a high malignant potential and that malignancy grading based on DNA measurements does not add any significant prognostic information to that obtained by morphologic diagnosis.
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3896255
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Nuclear DNA ploidy measurements based on tissue sections, although technically tedious and time consuming, can provide useful diagnostic and prognostic information. Methods for minimizing distributional errors and optimizing interpretation of DNA histograms are presented, and the diagnostic and prognostic significance of DNA ploidy measurements in gynecologic cancer and its precursors is reviewed.
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3896256
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We report on a rapid method for the isolation and purification of the yeast ribosomal proteins L3 and L2 using a simple instrumentation. Preparative dodecyl sulfate polyacrylamide gel electrophoresis was applied to the separation of cytoplasmatic ribosomal proteins of the large subunit from the yeast Saccharomyces cerevisiae. The polypeptides were removed from gel slices by electrophoretic elution. Subsequent analytical electrophoresis showed groups of proteins in all but two fractions. The latter were further analysed by a two-dimensional gel electrophoresis system which disclosed the purity of two polypeptides. They were identified as L3 and L2. Their molecular masses were 51.5 and 44 kDa as estimated from the gels. A possible application to the isolation of other yeast ribosomal proteins is discussed. An antiserum against the polypeptide L3 was raised in a rabbit. Applying an enzyme-linked immunosorbent assay (ELISA) we were able to determine the relative antibody concentration. Its specificity was demonstrated by immunoblotting.
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3896258
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Some characteristics of an enzyme-linked immunosorbent assay for the determination of immunoglobulin M anti-Salmonella lipopolysaccharide antibodies have been assessed. Immunoglobulin M anti-lipopolysaccharide antibodies in serum samples from most patients with typhoid fever cross-reacted with S. typhimurium lipopolysaccharide. However, absorbance values with S. typhi lipopolysaccharide were always higher than with the heterologous antigens. Serum samples from two patients with S. paratyphi B infection failed to show significant immunoglobulin M binding to S. typhi lipopolysaccharide. Serum samples from six rheumatoid arthritis patients were negative in this immunoenzymatic assay with S. typhi or S. typhimurium lipopolysaccharide as coating antigen. Finally, interference by specific immunoglobulin G in the immunoglobulin M anti-S. typhi lipopolysaccharide antibodies determination was excluded.
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3896261
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Vaccination represents a great success in clinical immunology and new approaches for designing vaccines of the future are now available. Protective antigens could be obtained by recombinant DNA technology or by synthesis. These new immunogens are likely to be poor immunogens and require the use of carrier and adjuvants. Both carrier and adjuvant present some limitations. In this report we consider how synthetic glycopeptides analogous to muramyl dipeptide (MDP) can be used as adjuvants under suitable conditions and can also overcome some problems due to the carrier. Muramyl dipeptides and chiefly Murabutide (NAcMur-L-Ala-D-Gln-alpha-n-butyl-ester) which is a derivative currently undergoing clinical trials can enhance the immune response to conventional purified vaccines. They can be also used in synthetic vaccines. In this case they are more active when covalently linked to the immunogen. Several examples of semisynthetic monovalent and polyvalent vaccines (Streptococcus, diphtheria toxin, Hepatitis B, Plasmodium) are described as well as totally synthetic vaccines (LH-RH, Foot-and-Mouth disease virus). They demonstrate that by using Murabutide biologically active antibodies can be produced under conditions applicable to human use.
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3896263
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Previous studies suggested that insulin requirement in type I diabetics could be split in a "basal" insulin requirement, mainly related to body weight and in a "post-prandial" insulin requirement, mainly related to carbohydrates intake. In the present study we wanted to investigate the occurrence and the magnitude of insulin response to protein only or fat only meals in normal subjects, trying to obtain some evidences for an insulin requirement possibly related to these substrates in diabetic subjects. Fat only meals did not evoke any insulin response while a small but significant increase in plasma insulin was observed after a protein only meal (from 16.6 +/- 2.85 to 25.83 +/- 2.52 microU at 90', p less than 0.05). Blood glucose remained unchanged after fat or protein meals. It is concluded that a small sovrabasal insulin dose would be probably required by diabetic patients after a protein meal: this is however so small that a carbohydrates related insulin dose given before a normal mixed meal would be able to normalize aminoacids as well as glucose metabolism.
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3896271
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The essentiality of zinc for humans was recognized in the early 1960s. The causes of zinc deficiency include malnutrition, alcoholism, malabsorption, extensive burns, chronic debilitating disorders, chronic renal diseases, following uses of certain drugs such as penicillamine for Wilson's disease and diuretics in some cases, and genetic disorders such as acrodermatitis enteropathica and sickle cell disease. In pregnancy and during periods of growth the requirement of zinc is increased. The clinical manifestations in severe cases of zinc deficiency include bullous-pustular dermatitis, alopecia, diarrhea, emotional disorder, weight loss, intercurrent infections, hypogonadism in males; it is fatal if unrecognized and untreated. A moderate deficiency of zinc is characterized by growth retardation and delayed puberty in adolescents, hypogonadism in males, rough skin, poor appetite, mental lethargy, delayed wound healing, taste abnormalities, and abnormal dark adaptation. In mild cases of zinc deficiency in human subjects, we have observed oligospermia, slight weight loss, and hyperammonemia. Zinc is a growth factor. Its deficiency adversely affects growth in many animal species and humans. Inasmuch as zinc is needed for protein and DNA synthesis and for cell division, it is believed that the growth effect of zinc is related to its effect on protein synthesis. Whether or not zinc is required for the metabolism of somatomedin needs to be investigated in the future. Testicular functions are affected adversely as a result of zinc deficiency in both humans and experimental animals. This effect of zinc is at the end organ level; the hypothalamic-pituitary axis is intact in zinc-deficient subjects. Inasmuch as zinc is intimately involved in cell division, its deficiency may adversely affect testicular size and thus affect its functions. Zinc is required for the functions of several enzymes and whether or not it has an enzymatic role in steroidogenesis is not known at present. Thymopoeitin, a hormone needed for T-cell maturation, has also been shown to be zinc dependent. Zinc deficiency affects T-cell functions and chemotaxis adversely. Disorders of cell-mediated immune functions are commonly observed in patients with zinc deficiency. Zinc is beneficial for wound healing in zinc-deficient subjects. In certain zinc-deficient subjects, abnormal taste and abnormal dark adaptation have been noted to reverse with zinc supplementation.
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3896276
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Recently in senile dementia of Alzheimer type, neuronal loss of cholinergic neurons in the substantia innominata is described. However these findings are based on morphological studies and, so far, these neurons have not been identified physiologically. In this study we tried to record these neurons electrophysiologically by antidromic activation. Cats were anesthetized with sodium pentobarbital and paralyzed with gallamine triethiodide. Three arreys of 3 or 4 silver-ball stimulating electrodes were fixed to the surface of the cerebral cortex. Each electrode was stimulated by rectangular pulses of 1 msec duration. Recording electrodes were glass micropipettes filled with 2 M NaCl saturated with fast green FCF and inserted into the ipsilateral substantia innominata stereotaxically. Twenty-eight neurons were constituted of mainly negative component; suggesting that they were recorded from cell bodies, not from axons. Also they responded in an all-or-none manner and showed constant latencies when stimulus intensities were at threshold level. When paired stimuli were applied, the latency of the action potential to the second stimulus was equal to that of the first one. These neurons were, therefore, considered to be activated antidromically. These neurons had axons of very slow conduction velocities. They are divided into two groups according to conduction velocities. The first group had mean conduction velocity of 2.3 m/sec and they responded to rather high frequency stimuli. The second group had mean conduction velocity of 1.0 m/sec and neurons belonging to this group showed quite long refractory periods. Based on conduction velocity analysis, the former is thought to include neurons with myelinated axons and the latter those with unmyelinated ones.(ABSTRACT TRUNCATED AT 250 WORDS)
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3896274
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Application of NMR, whether in imaging or in spectroscopy, is evolving rapidly and its clinical feasibility is to be fully assessed. It is not clear if speculation today will hold true tomorrow, but here present status of NMR in medicine, especially in its roles in research of the central nervous system are discussed as follow; NMR imaging in brain tumors, cerebrovascular diseases, degenerative diseases, trauma, spinal cord diseases, Imaging by surface coil, Contrast material in NMR imaging, Blood flow measurement by NMR, Chemical shift imaging, Studies of metabolism by 31P NMR spectroscopy, Recent advances and possible future role of NMR in medicine.
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3896278
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Fifty patients with mild essential (primary) hypertension entered a double-blind, parallel-group study with either nicardipine 30 mg three times daily or placebo, randomly assigned as monotherapy for 6 weeks. At the end of 6 weeks, the nicardipine-treated group had a statistically significant reduction in mean supine systolic/diastolic pressure of 21.2/15.0 mm Hg (P less than 0.001) compared with the nonsignificant reduction of 0.7/2.9 mm Hg in the placebo-treated group. The difference in mean response between the nicardipine- and placebo-treated groups was significant (P less than 0.001). In the nicardipine-treated group, the reduction in mean standing systolic/diastolic blood pressure, 17.9/13.8 mm Hg, was significant (P less than 0.001), whereas in the placebo-treated group the change was +3.0/-1.5 mm Hg. The difference between the two treatment groups was significant (P less than 0.001). In both treatment groups, changes in pulse rate were minor, and there was no evidence of tachyphylaxis occurring with nicardipine. Adverse experiences were minor in all cases except for one patient with muscle pain during treatment with nicardipine. Patients who received nicardipine showed a mean increase of 52% in plasma renin activity (PRA) after 6 weeks (P less than 0.01). Initial basal or stimulated PRA did not correlate with blood pressure reduction on nicardipine. Nicardipine 30 mg three times daily is a well-tolerated and effective antihypertensive agent.
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3896280
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The dose-response effects of oral nicardipine on the systemic blood pressure were examined in 54 patients with uncomplicated essential hypertension (DBP greater than or equal to 100 mm Hg). The study was designed in four sequential stages. A 2 week single-blind placebo run-in period was followed by dose titration with nicardipine at 2 week intervals. Patients achieving the target DBP less than or equal to 95 mm Hg were then crossed over to placebo for 2 weeks, following which the previous dose of nicardipine was readministered for 6 weeks. Forty-eight patients completed the dose-titration phase. The target DBP 95 mm Hg was achieved in 33; in eight after 10 mg three times daily, in 21 after 20 mg three times daily, in three after 30 mg three times daily and in one after 40 mg three times daily. In the 48 patients, systolic blood pressure was reduced from 188 +/- 25 to 158 +/- 21 mm Hg (P less than 0.001) and diastolic blood pressure from 111 +/- 9 to 93 +/- 13 mm Hg (P less than 0.001); heart rate increased from 81 +/- 7 to 87 +/- 13 beats min-1 (P less than 0.01). Thirty-one of the 33 patients completed the crossover to placebo, which was accompanied by a significant increase towards pretreatment blood pressure levels. Reinstitution of nicardipine at the previous dose resulted in a reduction of SBP and DBP to levels not significantly different from those at the end of the dose-titration stage.(ABSTRACT TRUNCATED AT 250 WORDS)
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3896279
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The purpose of this study was to test tolerance and the antihypertensive effect of nicardipine, a new calcium antagonist, in 31 elderly patients aged 57-95 years. The study was conducted as a double-blind trial. The patients were allocated randomly to either active or placebo treatment. Sixteen patients were given 10-30 mg of nicardipine three times a day (mean dose, 69.4 mg per day); 15 other patients received a matching placebo. After 4 weeks, nicardipine lowered mean blood pressure, and the changes in systolic and diastolic blood pressure were significantly greater in the nicardipine group than in the placebo group. Nicardipine was tolerated very well, and orthostatic hypotension was never observed. There was no change in heart rate. Plasma renin activity (PRA) was measured in eight patients. There was no correlation between PRA and the antihypertensive effect of nicardipine. A pharmacokinetic study performed in 15 elderly patients showed a fast rate of absorption and also higher plasma levels than those observed in hypertensive adults (mean age, 54 years). This trial demonstrates the effectiveness of nicardipine in elderly hypertensive patients.
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3896281
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Anti-ischaemic effects and safety of nicardipine were assessed in 14 patients with vasospastic angina using a placebo comparison, cross-over design study for 8-13 weeks. The average daily dose of nicardipine for optimal angina prevention was 84 mg (range 40-160 mg). Nicardipine administration, as compared with placebo, significantly reduced anginal frequency and nitroglycerin consumption during the single- and double-blind phases of the study. Nicardipine appears to be effective in the prevention of vasospastic angina and not to cause major adverse effects.
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3896282
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The intent of this study was to determine whether or not increased calcium-influx-mediated vasoconstriction is a primary pathogenetic disturbance in essential hypertension. Ten normotensive subjects (NT) (aged 45 +/- 12 years) and 23 patients with essential hypertension (EH) were studied. Twelve of the patients (aged 42 +/- 12 years) were classified as having mild EH and 11 patients (aged 49 +/- 11 years) as having moderate EH. Forearm blood flow and intra-arterial blood pressure were measured. Forearm vascular resistance (FVR) was calculated under basal conditions, during reperfusion following 10 min arterial occlusion, and after infusion into the brachial artery of sodium nitroprusside (0.15 and 0.6 microgram min-1 100 ml-1 tissue for 2 min each) and the calcium-influx inhibitors nicardipine (5 and 40 micrograms min-1 100 ml-1 tissue for 1 min each) and verapamil (80 micrograms min-1 100 ml-1 tissue for 1 min). FVR after 10 min arterial occlusion was lower in mild EH than in moderate EH and still lower in NT. FVR was comparable in the three groups following infusion of maximal doses of sodium nitroprusside, nicardipine, and verapamil. To allow for the vasodilator response to arterial occlusion, the decrease in FVR measured after each drug was divided by that obtained after arterial occlusion in each individual. The adjusted vasodilator response to nicardipine and verapamil, but not to sodium nitroprusside, was greater in moderate EH than in NT and mild EH. In the latter two groups the adjusted vasodilator responses were comparable.(ABSTRACT TRUNCATED AT 250 WORDS)
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3896283
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The effect of nicardipine on insulin secretion was examined in two double-blind, randomised, cross-over, placebo-controlled studies in normal volunteers. In the first study, the effect of acute dosing (via an intravenous infusion of 5 mg h-1 for 3 h) on the glucose, insulin, hormonal, and intermediary metabolite responses to an intravenous glucose tolerance test was determined in six healthy male volunteers. In the second study, the glucose, insulin, and C-peptide responses to intravenous tolbutamide (200 mg) was determined in another six male volunteers after oral dosing with nicardipine 30 mg three times daily for 1 week. A relative increase in insulin secretion was the principal finding of the first study. No other response was affected significantly. No significant differences between the nicardipine- and placebo-treated groups were noted in the insulin, glucose, and C-peptide measurements of the second study. In conclusion, treatment with nicardipine does not appear to impair insulin secretion in response either to an intravenous glucose load or intravenously administered tolbutamide.
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3896285
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Seven untreated patients with essential hypertension but without target organ damage were admitted to hospital. Urine was collected the following day from 08.00 to 13.00 h, 13.00 to 18.00 h, and 18.00 to 08.00 h. The protocol was repeated the next day following 30 mg oral nicardipine. Intra-arterial blood pressure (IABP), plasma volume, and plasma renin activity (PRA) also were measured daily. Following the single-dose study, the patients were treated as outpatients and received oral nicardipine 20, 30, or 40 mg four times daily. They were readmitted 2 months later for further study, at which time the protocol was repeated. Urine output between 08.00 and 13.00 h significantly increased after the single- and multiple-dose studies. Following the single-dose study, this diuresis was associated with a natriuresis. Urine output increased over the 24 h following multiple-dose treatment, but this increase was not statistically significant. During the multiple-dose 24 h study, there was an increase in urinary potassium (P less than 0.05). Mean IABP was reduced significantly after the single- and multiple-dose studies (P less than 0.02 and less than 0.05, respectively). During the study, there were no significant changes in plasma volume, weight, or plasma renin activity.
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3896284
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The influence of the calcium antagonist nicardipine on intrarenal sodium handling and angiotensin II induced secretion of aldosterone was investigated in 18 normotensive volunteers after the first dose and after 1 week of treatment (20 mg three times daily). A short-lasting natriuresis was observed, which was caused by a decreased reabsorption of sodium localised in both proximal and distal tubules. Log plasma renin activity (PRA) fell significantly on each day during angiotensin II infusion, while log-plasma aldosterone (PA) rose significantly. The log PRA/log PA ratio was increased during nicardipine treatment. The secretion of aldosterone, induced by angiotensin II, was not influenced by nicardipine treatment. No effect of the drug on adrenal responsiveness to angiotensin II was found.
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3896288
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In the Medical Research Council's IVth trial in Myelomatosis the possible benefit of adding vincristine to first line treatment with intermittent melphalan and prednisone has been assessed. This was analysed in 530 patients who were randomly allocated to receive vincristine or not. Survival was not improved by the addition of vincristine. A total of 268 patients reached plateau phase on first line therapy. Of these 226 patients were rerandomised either to continue receiving first line therapy for a further year or to cease therapy. At the present time there is a slight but not significant survival advantage in the group which received no further treatment on reaching plateau.
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3896289
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The practical usefulness of a panel of monoclonal antibodies recognising epithelial and lymphoid antigens has been evaluated on a series of 10 routinely processed thyroid tumours of uncertain origin. All 6 small cell tumours were shown to be of lymphoid origin whereas of the 4 large cell tumours two were lymphomas and two carcinomas. Two of the tumours, one large cell and one small cell, were undiagnosable due to technical reasons (crush artefact or small size of biopsy) and emphasized the value of immunohistology in this context. Clinical follow-up of all 10 cases indicated that these distinctions are of both prognostic and therapeutic value. It is concluded that immunocytochemistry using a carefully selected panel of monoclonal antibodies is a valuable and convenient means of making an objective distinction between anaplastic thyroid tumours of epithelial or lymphoid origin.
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3896292
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The dermal collagen of a patient with lipoid proteinosis was investigated by immunohistochemistry and biochemical analysis. The affected skin was found to contain significantly less collagen per unit dry weight than normal dermis but showed elevated levels of type 3 collagen with respect to type I. Purification of collagen types from affected skin after pepsin digestion showed no novel forms, but a doubling in the yield of type 5 collagen. These results correlated well with those of immunohistochemistry which showed a patchy, diffuse, widely distributed type 3 collagen and an increase in types 4 and 5 collagens associated with 'onion skin' endothelial basement membrane thickening. Estimation of collagen cross-links showed an abnormal pattern with a preponderance of the keto-imine form not normally associated with skin. These results strongly suggest that lipoid proteinosis involves a primary perturbation of collagen metabolism.
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3896290
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Infection with Plasmodium berghei leads to a rapidly lethal disease in different strains of mice. Nude athymic mice are not able to produce circulating antibodies (IgG or IgM) against plasmodial antigens. Nevertheless, plasmodium-related antigens can be detected in the glomeruli of nude mice, in relation to the rising parasitaemia. This deposition is unrelated to the deposition of other immunoreactants (IgG, IgM or C3). The presence of the latter as well as the circulating auto-antibodies did not correlate with the intercurrent infection and control and experimental animals behaved likewise. These results indicate an intraglomerular localization of free malarial antigens. It is suggested that this may represent a basic mechanism for in situ formation of immune complexes in immunocompetent mice.
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3896295
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50 cases of advanced, intermediate (18) and high grade (32) non-Hodgkin's lymphoma (NHL) including 16 with Burkitt lymphoma have been treated with very high dose chemotherapy and autologous bone marrow transplantation (ABMT). These cases represent a retrospective analysis of the combined experience of a recently established collaborative group. 31 patients were treated with a protocol used in Lyon, 12 with that used in Marseille and seven with that used in London. Although the details of drug administration differed, each protocol was based on high dose alkylating agent (cyclophosphamide or melphalan), BCNU and cytosine arabinoside. 16 patients had drug resistant progressive NHL. Of these 11 responded to high dose treatment (nine CR, two PR). The duration of CR in this group was short (median 104d) and only one patient was in CR at 1 year. 19 patients had relapsed on previous therapy but were still responding to conventional rescue therapy. Following high dose therapy 47% of these patients are in continuous CR with a median time of observation of 300 d (73-962 d). Seven patients were partial responders to conventional induction therapy. Of these, six had a CR with high dose treatment and are still in CR (range 39-1230 d, median 200 d). Eight patients received high dose therapy as intensification after a long delay to CR with conventional treatment. Of these, four are alive and in remission 124-763 d after treatment. The high dose protocols produced significant morbidity with 25 patients (50%) having major or minor treatment-related complications, and there were seven treatment related deaths (14%). However, these results indicate that durable responses can be obtained with high dose chemotherapy in patients who have been heavily treated and indicate a role for this type of treatment at an earlier stage in advanced non-Hodgkin's lymphoma.
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3896296
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Thirty-nine patients with severe aplastic anaemia were transplanted from HLA identical sibling donors. Irradiation was not used in the pre-transplant immunosuppressive protocol and cyclosporine was used as the post graft immunosuppressive agent. The incidence of primary graft failure (no take) was low occurring in 3/38 evaluable patients. Late graft failure 4-7.5 months post BMT occurred in five patients and was associated with withdrawal of cyclosporine therapy. Mixed lymphocyte chimaerism was demonstrated in 3/5 cases at the time of late graft failure and subsequent marrow recovery was autologous in four patients. Mortality from graft failure was low with 2/38 evaluable patients (5%) dying from this complication.
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3896297
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Many investigators have concluded that polymorphonuclear leucocytes (PMN) express ABH antigens in parallel to red cells (RBC). We have examined human PMN for ABH antigens using human isoantibodies and mouse monoclonal antibodies with three highly sensitive and specific two-stage assay systems: fluorescence flow cytometry, immunofluorescence microscopy, and avidin-biotin immunoperoxidase microscopy. In all three assays the ABH antigens could not be detected on the surface of PMN. Previous reports alleging that ABH antigens occur on PMN probably represent false positive reactions due to inherent technical problems.
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3896298
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Soluble crosslinked fibrin derivatives (XDP) in serum were determined by enzyme immunoassay utilizing monoclonal antibodies and compared with serum fibrinogen/fibrin degradation products (FDP) assayed by conventional techniques. In healthy subjects and patients with miscellaneous disorders not usually associated with activation of the haemostasis mechanism, mean XDP levels were 45 and 70 ng/ml respectively. However, elevated levels of XDP occurred in conditions commonly associated with intravascular and possibly extravascular activation of the coagulation system. Markedly raised mean XDP values (677-6900 ng/ml) occurred in treated pulmonary embolism, disseminated neoplasia, severe inflammatory disorders and complicated postoperative states, and lesser but significant elevation (mean 150-400 ng/ml) in treated venous thrombosis, uneventful postsurgical states, localized neoplasia, liver disease and symptomatic arterial disease. Levels during initial streptokinase therapy (mean 24 000 ng/ml) fell tenfold as treatment was continued. The degree of XDP elevation over normal values was significantly higher than that of FDP in conditions with a propensity for venous thrombosis (post-operative states, disseminated neoplasia and inflammatory diseases) than in liver disease, localized neoplasia or patients receiving heparin therapy for venous thromboembolism.
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3896301
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Until recently induction of ovulation in patients resistant to clomiphene has required gonadotrophin therapy. This has entailed intensive biochemical monitoring to ascertain the correct dosage and to avoid ovarian hyperstimulation. Described here is a simple, safe effective method of ovulation induction, using pulsed luteinizing hormone releasing hormone and requiring only minimal, readily available monitoring methods.
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3896302
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Methanol oxidase isolated from Hansenula polymorpha contains two distinct flavin cofactors in approximately equal amounts. One has been identified as authentic FAD and the other as a modified form of FAD differing only in the ribityl portion of the ribityldiphosphoadenosine side chain. The significance of this finding is as yet unknown. Previous studies have shown that cyclopropanol irreversibly inactivates methanol oxidase [Mincey, T., Tayrien, G., Mildvan, A. S., & Abeles, R. H. (1980) Proc. Natl. Acad. Sci. U.S.A. 77, 7099-7101]. We have now established that inactivation is accompanied by covalent modification of the flavin cofactor. The stoichiometry of this reaction is 1 mol of cyclopropanol/mol of active flavin. The structure of the covalent adduct was determined by NMR, IR, and UV spectral studies to be an N5,C4a-cyclic 4a,5-dihydroflavin. Reduction of the covalent adduct with NaBH4 at pH 9.0 before removal from the enzyme converted it to the 1-(ribityldiphosphoadenosine)-substituted 4-(3-hydroxypropyl)-2,3-dioxoquinoxaline. Cyclopropyl ring cleavage accompanies inactivation, and covalent bond formation occurs between a methylene carbon of cyclopropanol and N5 of flavin. Methanol oxidase was also reconstituted with 5-deazaflavin adenine dinucleotide (dFAD). Reconstituted enzyme did not catalyze the oxidation of alcohols to the corresponding aldehydes, nor did reduced reconstituted enzyme catalyze the reverse reaction. Incubation of reconstituted enzyme with cyclopropanol resulted in an absorbance decrease at 399 nm, but no irreversible covalent modification of the deazaflavin cofactor. A reversible addition complex between cyclopropanol and dFAD is formed. The structure of that complex was not definitively established, but it is likely that it is formed through the addition of cyclopropoxide to C5 of dFAD. The failure of dFAD-reconstituted methanol oxidase to catalyze the oxidation of substrate, as well as the lack of reaction with cyclopropanol, supports a radical mechanism for alcohol oxidation and cyclopropanol inactivation. Methanol oxidase catalyzes the oxidation of cyclopropylcarbinol to the corresponding aldehyde. No ring-opened products were detected. The failure to form ring-opened products has been used as an argument against radical processes [MacInnes, I., Nonhebel, D. C., Orsculik, S. T., & Suckling, C. J. (1982) J. Chem. Soc., Chem. Commun., 121-122]. We present arguments against this interpretation.
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3896303
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Functional groups of the highly conserved uridine at position 33 in the anticodon loop of yeast tRNAPhe were altered by a synthetic protocol that replaces U-33 with any desired nucleotide and leaves all other nucleotides of the tRNA intact. The U-33-substituted tRNAs were prepared in an eight-step protocol that begins with partial cleavage of tRNAPhe at U-33 by ribonuclease A. By use of the combined half-molecules as substrate, U-33 was removed from the 5' half-molecule in three steps and then replaced by using RNA ligase to add the desired nucleoside 3',5'-bisphosphate. Each position 33 substituted 5' half-molecule was isolated and annealed to the original 3' half-molecule from the ribonuclease A digestion. The two halves were then rejoined in three steps to give a full-size tRNAPhe variant. This protocol should be applicable to other RNA molecules where a nucleotide substitution is desired at the 5' side of an available unique cleavage site. Seven substituted tRNAPheS containing uridine, pseudouridine, 3-methyluridine, 2'-O-methyluridine, cytidine, deoxycytidine, and purine riboside at position 33 were assayed for aminoacylation with yeast phenylalanyl-tRNA synthetase. Each of the seven tRNAs aminoacylated normally. Thus, unlike the adjacent guanine residue at position 34, U-33 is not involved in the interaction between yeast tRNAPhe and yeast phenylalanyl-tRNA synthetase.
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3896304
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The forward and reverse kinetics of open complex formation between Escherichia coli RNA polymerase and the lac UV5 promoter have been studied in the temperature range of 15-42 degrees C. The standard two-step model, involving the formation of a closed intermediate, RPc, followed by an isomerization that leads to the active complex RPo, could not account for the present data. The promoter-enzyme lifetime measurements showed an inverse temperature dependence (apparent activation energy, -35 kcal/mol). A third step, which is very temperature dependent and which is very rapid at 37 degrees C, was postulated to involve the unstacking of DNA base pairs that immediately precedes open complex formation. Evidence for incorporating a new binary complex, RPi, in the pathway was provided by experiments that distinguished between stably bound species and active promoter after temperature-jump perturbations. These experiments allowed measurement of the rate of reequilibration between the stably bound species and determination of the corresponding equilibrium constant. They indicated that the third step became rate limiting below 20 degrees C; this prediction was checked by an analysis of the forward kinetics. A quantitative evaluation of the parameters involved in this three-step model is provided. Similar experiments were performed on a negatively supercoiled template: in this case the third equilibrium was driven toward formation of the open complex even at low temperature, and the corresponding step was not rate limiting.
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3896305
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By chemical and enzymatic methods, two stable complexes between Escherichia coli RNA polymerase and a linear DNA fragment carrying the lac UV5 promoter have been identified. In these binary complexes, DNA can adopt two alternate conformations as a function of temperature. Contacts between RNA polymerase and the DNA phosphate backbone are indistinguishable in these two forms, as revealed by probing with pancreatic DNase I. Protection of enhancement of the reactivity of the bases toward (CH3)2SO4 occurs, however, only in the form that predominates above 22 degrees C, RPo. The form stable at low temperature, RPi, is a "closed" complex since no single-stranded region is detectable in the DNA. The strong temperature dependence of the equilibrium constant, the midpoint value of the transition, and the rate of conversion between these two forms are in close agreement with a series of measurements performed by using a transcriptional assay and reported in the preceding paper [Buc, H., & McClure, W. R. (1985) Biochemistry (preceding paper in this issue)]. These data further support the postulated mechanism of open complex formation involving three sequential steps: R + P in equilibrium RPc in equilibrium RPi in equilibrium RPo. The binary complex RPc, which accumulates transiently at 37 degrees C before the isomerization leading to open complex formation, is not significantly protected against enzymatic cleavage or chemical modification and is therefore distinct from RPi and RPo.(ABSTRACT TRUNCATED AT 250 WORDS)
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3896306
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A rapid large-scale procedure for the purification of the LexA repressor of Escherichia coli is described. This procedure allows one to get more than 100 mg of purified protein from 100 g of bacterial paste with a purity of at least 97%. This method is comparable to earlier, far more complicated purification procedures giving clearly smaller yields. It is shown that the LexA protein may be identified spectroscopically by a large A235/A280 ratio and very pronounced ripples in the absorption spectrum arising from a high amount of phenylalanine residues with respect to that of the other aromatic amino acids. Polyacrylamide gel electrophoresis has been used to study the specific interaction of LexA with a recA operator fragment. The quaternary structure of LexA has been studied by equilibrium ultracentrifugation and sedimentation velocity measurements. The sedimentation coefficient increases with increasing LexA concentration, indicating that LexA is involved in self-association. This finding has been confirmed by equilibrium ultracentrifugation. The results are best described by a monomer-dimer and a subsequent dimer-tetramer equilibrium, with an association constant of 2.1 X 10(4) M-1 for the dimer and 7.7 X 10(4) M-1 for the tetramer formation. These relatively small association constants determined under near-physiological pH and salt conditions suggest that in vivo LexA should be essentially in the monomeric state. The degree to which LexA decreases the electrophoretic mobility of a 175 base pair fragment harboring the recA operator suggests that the recA operator interacts nevertheless with a LexA dimer. However, our results may be also explained by the binding of a LexA monomer with a simultaneous bending of the DNA fragment.
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3896308
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Monoclonal antibodies directed against antigenic determinants on the beta and beta' subunits of the Escherichia coli RNA polymerase were characterized by using d(A-T)n-directed transcription assays. Antibodies were prepared by using purified subunits as immunogens, and seven anti-beta and five anti-beta' monoclonal antibodies were generated. Inhibitory anti-beta monoclonal antibodies were found to affect RNA polymerase during synthesis of r(A-U)n, abortive initiation of pApU and UpApU, and elongation by preformed ternary complexes. A comparative enzyme study of r(A-U)n synthesis showed the core polymerase to be more sensitive to inhibition by the anti-beta monoclonal antibody than was the holoenzyme. In contrast, the inhibition effected by the anti-beta' monoclonal antibody was found to be 90% or greater for each of the d(A-T)n-directed assays used. The different inhibitory patterns exhibited by the anti-beta and anti-beta' monoclonal antibodies suggest that the beta and beta' subunits engage in different roles during transcription. Kinetic analysis of the abortive initiation reaction in the presence and absence of the inhibitory antibodies resulted in distinctive but complex modes of inhibition. Inhibition by the anti-beta monoclonal antibody 210E8 was noncompetitive with regard to UTP and competitive for UpA incorporation; at increased UpA concentration, the inhibition was completely reversed. Inhibition of the abortive synthesis of UpApU by the anti-beta' monoclonal antibody 311G2 was noncompetitive with regard to both UpA and UTP incorporation. When the preformed ternary elongation complex was used, inhibition by the anti-beta monoclonal antibody was mixed with regard to the ribonucleoside triphosphate substrates.(ABSTRACT TRUNCATED AT 250 WORDS)
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3896307
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The complex of Artemia salina ribosomes and Escherichia coli acetylvalyl-tRNA could be cross-linked by irradiation with near-UV light. Cross-linking required the presence of the codon GUU, GUA being ineffective. The acetylvalyl group could be released from the cross-linked tRNA by treatment with puromycin, demonstrating that cross-linking had occurred at the P site. This was true both for pGUU- and also for poly(U2,G)-dependent cross-linking. All of the cross-linking was to the 18S rRNA of the small ribosomal subunit. Photolysis of the cross-link at 254 nm occurred with the same kinetics as that for the known cyclobutane dimer between this tRNA and Escherichia coli 16S rRNA. T1 RNase digestion of the cross-linked tRNA yielded an oligonucleotide larger in molecular weight than any from un-cross-linked rRNA or tRNA or from a prephotolyzed complex. Extended electrophoresis showed this material to consist of two oligomers of similar mobility, a faster one-third component and a slower two-thirds component. Each oligomer yielded two components on 254-nm photolysis. The slower band from each was the tRNA T1 oligomer CACCUCCCUVACAAGp, which includes the anticodon. The faster band was the rRNA 9-mer UACACACCGp and its derivative UACACACUG. Unexpectedly, the dephosphorylated and slower moving 9-mer was derived from the faster moving dimer. Deamination of the penultimate C to U is probably due to cyclobutane dimer formation and was evidence for that nucleotide being the site of cross-linking. Direct confirmation of the cross-linking site was obtained by "Z"-gel analysis [Ehresmann, C., & Ofengand, J. (1984) Biochemistry 23, 438-445].(ABSTRACT TRUNCATED AT 250 WORDS)
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3896309
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Five des-Trp1,Cha3,X6 analogues of alpha-factor, where X = Ala, Val, Ile, Nle, or D-Leu and X = Leu in the natural alpha-factor sequence, were prepared by solution-phase techniques utilizing isobutyl chloroformate or 1-hydroxybenzotriazole accelerated active esters as the coupling agents. Purification to 98% or greater homogeneity was accomplished by high-performance liquid chromatography on a reversed-phase muBondapak C18 column with methanol/water/trifluoroacetic acid as the mobile phase. Three of the synthesized analogues (X6 = Val, Ile, Nle) induced morphogenesis and increased agglutinability in a cells. These substitutions demonstrate that a gamma-branched side chain at position 6 is not essential for biological activity. All of the active analogues induced morphogenesis at lower concentrations than they induced enhanced agglutinability. These results and other structure-activity relationships [Baffi, R. A., Shenbagamurthi, P., Terrance, K., Becker, J. M., Naider, F., & Lipke, P. (1984) J. Bacteriol. 158, 1152-1156] indicate that the agglutination and morphological responses to alpha-factor can be varied independently. Replacement of Leu6 with Ala or D-Leu resulted in inactive analogues that were not antagonistic for alpha-factor activity. Cell-mediated hydrolysis experiments indicated that the biological activities of the alpha-factor analogues are independent of their rates of degradation. All position 6 analogues were hydrolyzed more slowly than the parent compound, suggesting that the enzyme which degrades alpha-factor is highly specific for the native structure.
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3896315
|
The fluorescence lifetime of oxygen-forming photosynthetic systems as a function of closed traps has been studied by several groups using light and poisons (usually 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)) to fix the closed trap state during the experiment. These measurements have now been carried out using light alone, by means of pump and probe laser pulses and a very efficient fast photomultiplier-digitizing system. It is found that the absolute amplitude of fast fluorescence (mean tau, approx. 0.3 ns) remains constant until over half the traps are filled. The amplitude of the slow fluorescence (tau approximately equal to 1.2 ns) increases with pump energy, and its response is best fit with a lag or finite rise-time of approx. 200 ps. This novel result is consistent with the hypothesis that the slow component of the fluorescence is actually recombination luminescence in the trap. Thus, the full trapping time, i.e., the time to form the P+I- state from an excitation in the O2 photosystem, is relatively slow.
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3896319
|
Previous reports regarding the modulation of prostaglandin release from tissues by serum components did not identify these components. We have found that inhibition of prostacyclin release from human umbilical artery by human serum is attributable to serum macromolecules. We demonstrate that such inhibitory activity depends on macromolecular size and may result from macromolecule/cell surface interactions.
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3896320
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Although diabetogenic and insulin-like activities are intrinsic properties of the growth hormone (GH) molecule, it has been frequently suggested that the hormone must be proteolytically processed for these activities to be expressed. If this is correct, then derivatives of GH having resistance to appropriate proteolytic attack might not have diabetogenic and/or insulin-like activity. The purpose of the present study was to prepare derivatives of human GH that are resistant to digestion by trypsin and to determine whether they possess diabetogenic or insulin-like activity. Three derivatives were prepared from purified native human GH in which lysine residues were modified with methyl acetimidate, citraconic anhydride or S-ethyl-thioltrifluoroacetate, and one in which arginine residues were modified with camphorquinone-10-sulfonic acid. Comparisons of peptide maps of tryptic digests of these derivatives with that of unmodified human GH indicated that all four were resistant to proteolysis by trypsin. All of these trypsin-resistant forms of human GH were found to possess significant growth-promoting, diabetogenic and insulin-like activities, although all activities were attenuated to some extent in each derivative. The relative potencies of the human GH derivatives in a radioimmunoassay for human GH were somewhat similar to their order of potency in the growth-promoting and diabetogenic assays. These results suggest that if proteolytic processing of the GH molecule is involved in the expression of one or more of its biological activities, such processing probably does not involve a trypsin-like proteinase.
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3896318
|
When accumulation of squalene was used as a measure of the flow of carbon into the sterol pathway in whole cells of semi-anaerobic Saccharomyces cerevisiae, both ergosterol and cholesterol were found to be inhibitory. However, at equivalent concentrations in the medium ergosterol was substantially the more potent inhibitor. Marked differences found in the absorption and esterification of the two sterols failed to account for the observed difference in their capacities to act as feedback agents. Cholesterol was much more effectively absorbed as well as esterified, but, when the abilities of the two sterols to lower the squalene level were calculated on the basis of free sterol in the cells, ergosterol remained more effective by a factor of four.
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3896322
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The lateral motion of membrane lipids on lipopolysaccharide-stimulated murine B lymphocytes was measured using photobleaching recovery techniques. The mobility of the phospholipid analog 3,3'-dioctadecylindocarbocyanine iodide (DiI) was measured at 37 degrees C on B lymphocytes 48 h after stimulation by various concentrations of lipopolysaccharide. DiI mobility on lymphoblasts from cultures stimulated with 10 micrograms/ml lipopolysaccharide was reduced 50% compared with unstimulated, small B cells. However, both lower and higher lipopolysaccharide concentrations caused some decrease in lipid mobility. Lipid mobility was measured on B cells stimulated with 10 micrograms/ml lipopolysaccharide at zero time, on lymphoblasts at 18, 24, 48 and 72 h, and on immunoglobulin (Ig) -secreting lymphocytes at 96 h. The diffusion coefficient of DiI on both control and lipopolysaccharide-treated cells at zero time is 6.3 X 10(-9) cm2 X s-1. This value remains unchanged for unstimulated cells over 72 h. Lipid mobility of lipopolysaccharide-activated lymphoblasts decreased during incubation with lipopolysaccharide to 5.0, 3.4, 2.8 and 2.4 X 10(-9) cm2 X s-1 after 18, 24, 48 and 72 h, respectively. DiI mobility on immunoglobulin (Ig) -secreting lymphocytes identified at the foci of Protein A-coated sheep red blood cells plaques is 8.6 X 10(-9) cm2 X s-1, a value similar to that of unstimulated B cells. The effect of introducing various concentrations of a synthetic glucocorticoid, triamcinolone acetonide (TA), to 48 h lipopolysaccharide-stimulated cells for 6 h was examined. Maximal TA effect was observed at a concentration of 10(-7) M, which caused an increase in lipid mobility to 7.5 X 10(-9) cm2 X s-1. Exposing resting B cells (t = 0) or lymphoblasts (t = 24, 48 or 72 h) to TA for 3 h had no effect on lipid mobility. Treatment for 6 h with 10(-7) MTA increased DiI diffusion to 12.6, 9.9, 7.5 and 6.8 X 10(-9) cm2 X s-1 on control cells and on 24, 48 and 72 h lipopolysaccharide-activated lymphoblasts, respectively. A longer incubation of 12 h with 10(-7) MTA caused no further change in lipid lateral diffusion. The response was glucocorticoid-specific. In lymphoblasts (48 h) incubated an additional 6 h with 10(-7) MTA and a 100-fold excess of cortexolone or progesterone, the increase in lipid mobility was substantively blocked; estradiol and testosterone had no effect on lipid lateral diffusion.(ABSTRACT TRUNCATED AT 400 WORDS)
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3896321
|
Largomycin, an antibiotic and antitumor protein, purified from the culture broth of Streptomyces pluricolorescens, displayed specific proteolytic activity. Pure largomycin did not degrade a number of substrates commonly used for detection of aminopeptidase, endopeptidase and carboxypeptidase activity. Pure largomycin degraded angiotensin II, bradykinin, a few dipeptides and a number of proteins of KB cell plasma membranes. The biological activity and the proteolytic activity of largomycin showed similar temperature-dependent patterns, suggesting that one protein is responsible for both activities. The apoprotein of largomycin, which did not show antibiotic activity, contained the proteolytic activity.
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3896325
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We analyzed the DNA sequences taking as an elementary pattern segments of increasing length from the codon to the gene. We have thus been able to identify part of the constraints from which originates the use of the code degeneracy in each gene. Our results show that the strategy of codon use is not solely related to the translation apparatus characteristics.
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3896326
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Using learning techniques previously described in this journal, we have built an expert system able to point to the start DNA point of a sequence and therefore to recognize a promoter. However, to build this system, we have focused on the TATA box and its environment. We have used this expert system to look for new promoters and also to construct new promoters. The results obtained are discussed.
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3896323
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A method for measuring the microbial cell dynamic loss modulus has been developed. The acoustic wave relaxation coefficient in the suspension of Escherichia coli cells was measured in relation to ultra-sound frequency and cell concentration. Using these data and proceeding from the ideas on acoustic and viscous properties of suspensions the volume dynamic loss modulus of cells was calculated. The obtained results were compared with the data on the loss modulus of albumin globules aggregates.
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3896328
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The transfer of de novo synthesized lipids from microsomes to lipid non-synthesizing membranes was studied in vivo and in vitro from the ratios of specific radioactivities of [14C]cholesterol, [14C] and [32P]phosphatidylcholine and [32P]phosphatidylethanolamine in the nuclei and mitochondria to that in microsomes. The radioactivity of lipids transferred from microsomes to mitochondria and nuclei was identical both in vitro and in vivo and when the lipid-exchange protein of the 105 000 g supernatant was used. Acceleration of lipid metabolism in the liver of gamma-irradiated rats was concomitant with the increase in the rate of labeled cholesterol transfer cation to liver cell nuclei and mitochondria, but remained unchanged in in vitro studies involving lipid-exchange protein. The reduction of phosphatidylethanolamine transfer to the nuclei in vitro and in vivo diminished in the same way. The existence in the cell of mechanisms of transfer of de novo synthesized cholesterol other than lipid-exchange protein is postulated.
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3896327
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We examine the implications of significant inseparable behaviour in centre-surround retinal cell types. From the form of a spatiotemporal centre-surround (CS) model which agrees qualitatively with physiological observations, we find that the sustained/transient dichotomy is a poor distinction for X-type/Y-type retinal ganglion cells since both exhibit inseparability. Static centre-surround models and spatiotemporal separable models are not valid for time-varying stimuli. Our results contradict the models for X- and Y-type ganglion cells proposed by Marr and Hildreth (1980) and Marr and Ullman (1981), and raise doubts about the physiological validity of Marr's zero-crossing theory. The CS filter is an attractive precursor to the extraction of 2-d motion information.
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3896330
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The ASIF index which combines both steric and electronic factors is applied to the comparative study of the reactivity of yeast tRNAAsp and yeast tRNAPhe using the coordinates deduced from their crystal structures. The results compared with the known experimental reactivities in solution are somewhat less perfect for tRNAAsp than for tRNAPhe. The reasons for this situation are probably related to the differences existing between the structures of tRNAAsp in the crystal and in solution.
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3896329
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The work presented here aims at investigating the in vitro relationship between amino acids and pancreatic hormonal release in the suckling rat. Among the 20 most usual amino acids, 12 of them were tested on perifused pieces of pancreas in 5.5-day-old rats at a low glucose concentration. Their effects were compared to those induced by a 20 amino acid mixture. A 20 amino acid mixture (10.3 mM) stimulated glucagon and insulin release (154 and 208%, respectively). In the mixture, the 4 pooled amino acids Ala-Gly-Ser-Thr (at 1.4 instead of 4.2 mM) did not induce further modification of the glucagon or insulin release. However, the 3 branched chain amino acids Ile-Leu-Val (at 2.9 instead of 1.4 mM) or the following amino acids Arg-Asn-Phe-Pro-Tyr (at 3.2 instead of 1.6 mM) modulated glucagon or insulin release in the presence of the amino acid mixture. In the absence of Ile-Leu-Val, the amino acid mixture had no effect on the insulin release: 122 compared to 208%. This seems specific to the chemical nature of Ile-Leu-Val since in the absence of Arg-Asn-Phe-Pro-Tyr, the amino acid mixture was still effective on the insulin release (178 compared to 208%). In the absence of Ile-Leu-Val, the amino acid mixture was effective on glucagon release, and revealed the cellular specificity of the branched chain amino acid action.
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3896331
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Base-pairing properties of O-methylated nucleic-acid bases have been systematically investigated using both semi-empirical quantum-mechanical methods and a second-order perturbation formalism. The energetic, steric and electronic properties of (a) the individual methylated bases, (b) possible base-pairs formed between O-methylated and normal bases, and (c) mini-helices incorporating O-methylated bases were calculated. Two types of base-paired complexes were obtained: Those involving classical linear hydrogen bonds, and those involving bifurcated hydrogen-donor-hydrogen-acceptor interactions. In most complexes the presence of mispairs in the helical structure of nucleic acids is expected to create a local perturbation in the structure of the helix. Even though the most stable planar configurations of the mispairs may deviate markedly from those in the regular double helix, the induced deformations in the structure of the backbone are relatively small. Internal energies and geometries of mispairs are strongly affected by the conformation of the exocyclic group of the methylated bases. Another important contribution to the stability of various base-pairing schemes comes from stacking interactions.
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3896334
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An insulin dependent diabetic patient was resistant to all but central venous insulin administration. For this reason plasma exchange was tried and it restored insulin responsiveness. An anti-insulin IgG antibody was identified in the patient's plasma. Plasma exchange reduced antibody levels and these correlated with daily insulin requirements. Kinetic analysis of anti-insulin antibodies, however caused us to doubt that they were the sole cause of the problem. Although the mechanism remains unclear, plasmapheresis proved to be an effective method of treating this patient's insulin resistance.
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3896324
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A review of modern concepts of conformational motions in proteins is presented. Problems relevant to the theory of the dynamic behavior of different structural elements of biomacromolecules and a protein globule as a whole are discussed. A theory of electron-conformation interactions is presented and its applications to electron-transport reactions, the enzymic act, and the diffusion of the ligands in the proteins are discussed.
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3896336
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Rats with a gentic deficiency of phosphorylase kinase have been treated with the 1,4-alpha-glucosidase inhibitor, Acarbose. Lysosomal glycogen metabolism has been markedly altered and the results support the concept of a feedback control mechanism operating on the uptake mechanism into the lysosomal compartment.
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3896337
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3-O-methyl-D-glucose (which is not metabolized in isolated parenchymal cells) was used to characterize the hexose transport process in hepatocytes prepared from 24 h fasted rats. The Vmax and Km obtained were 161 +/- 12 nmol/mg dry wt./min and 39 +/- 4 mM respectively (Europe-Finner GN, 1984, Biosci. Rep. 4, 483-489). Streptozotocin-induced diabetes decreased the Km of the system by 50% to a value of 19 +/- 6 mM without causing any change in the Vmax. Short term insulin treatment of cells prepared from 24 h diabetic rats appeared to partially return the system to normal.
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3896338
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The rates of utilization of both glucose and glutamine are high in rapidly dividing cells such as enterocytes, lymphocytes, thymocytes, tumour cells; the oxidation of both glucose and glutamine is only partial, glucose to lactate and glutamine to glutamate, alanine or aspartate; and these partial processes are termed glycolysis and glutaminolysis respectively. Both processes generate energy and also provide precursors for important biosynthetic processes in such cells. However, the rates of utilization of precursors for macromolecular biosynthesis are very low in comparison to the rates of partial oxidation, and energy generation per se may not be the correct explanation for high rates of glycolysis and glutaminolysis in these cells since oxidation is only partial and other fuels can be used to generate energy. Both the high fluxes and the metabolic characteristics of these two processes can be explained by application of quantitative principles of control as applied to branched metabolic pathways (Crabtree & Newsholme, 1985). If the flux through one branch is greatly in excess of the other, then the sensitivity of the flux of the low-flux pathway to regulators is very high. Hence, it is suggested that, in rapidly dividing cells, high rates of glycolysis and glutaminolysis are required not for energy or precursor provision per se but for high sensitivity of the pathways involved in the use of precursors for macromolecular synthesis to specific regulators to permit high rates of proliferation when required - for example, in lymphocytes in response to a massive infection.
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3896340
|
Suramin that accumulates in rat liver Kupffer cell lysosomes and inhibits the intralysosomal proteolysis was used to suppress the functional activity of these particles during liver damage (acute CCl4 hepatitis). Polyvinylpyrrolidone that does not disturb protein catabolism in liver lysosomes was employed for reference. According to the characteristic changes in lysosomes induced by suramin (inhibition of acid phosphatase, decrease of the rate of the intralysosomal proteolysis in the liver) and PVP the damaged liver was able to accumulate the lysosomotropic substances under study. Suramin aggravated liver damage and increased the lysosomal labilization, whereas PVP exhibited the protective action. The unfavourable effect of suramin may be linked with the suppression of catabolism of Kupffer cell lysosomes. The data obtained suggest the lack of safety of using the inhibitors of intralysosomal proteolysis in patients with acute hepatitis.
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3896339
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It has been shown that in postnatal animals, the activity of lysosomal proteinases in the distal part of the small intestine was considerably higher than in the proximal one. With transition from milk to definitive nutrition, the activity of lysosomal proteinases gets equalized in the proximal and distal parts of the small intestine. The data concerning the proximo-distal gradient of distribution of the activity of lysosomal proteinases have been supported. Transition from milk to definitive nutrition has given rise to ultrastructural alterations in the lysosomal apparatus.
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3896341
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Forty-eight fractions of polypeptides including 39 fractions with a molecular weight of 14-95 kD were identified in chick adenohypophysis by sodium dodecyl sulphate electrophoresis in 10-20% gradient polyacrylamide gel slabs. The immunochemical identification of the polypeptides was performed with the aid of the electroblotting of proteins and antisera to human STH, to bovine prolactin, and to the tissue-specific antigen A-1 of chick adenohypophysis. Antisera to human STH and to antigen A-1 reacted with the same major polypeptide fraction, m.w. 26 kD, characteristic of the caudal lobe of the adenohypophysis. Immunoreactive prolactin was present in chick adenohypophysis in the form of a polypeptide fraction with a molecular weight of 25 kD and in the form of two minor fractions of polypeptides with molecular weights of 27 and 28 kD. The data obtained indicate the identity of the adenohypophyseal tissue-specific antigen A-1 to chick STH.
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3896342
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Using polyclonal antibodies to an interspecies antigen of erythroblasts (Ag-Eb) with a molecular weight 69 000 D this antigen was revealed by immunofluorescence on the cells of the peripheral blood of patients with erythroleukemias and, in several cases, in those with undifferentiated leukemias. The possibility was shown of using these antibodies as a diagnostic tool when studying erythroleukemias and acute undifferentiated leukemias.
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3896344
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Autologous bone marrow transplantation (BMT) was utilized as therapy for 23 patients with acute lymphoblastic leukemia (ALL) in second or greater remission. Bone marrow was treated in vitro with a combination of monoclonal antibodies, consisting of BA-1, BA-2, BA-3, and baby rabbit complement (BRC'). All patients were prepared for transplantation with cyclophosphamide and fractionated total body irradiation. Engraftment occurred in all 23 patients. Seven of 23 patients remain relapse-free from six to 32 months (median, 21.4 months) posttransplant. Failures were due to relapse with the exception of one patient who died of infection. This study demonstrates that autologous BMT using in vitro marrow treatment with BA-1, BA-2, BA-3, and BRC' is safe, allows engraftment, and results in prolonged survival for some patients with ALL in second or greater remission.
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3896345
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The murine bone marrow culture technique was used to prepare donor marrow for bone marrow transplantation across minor histocompatibility complex differences. Previous studies have shown that theta-positive cells are rapidly lost from such cultures and that transplantation of cultured marrow across major histocompatibility complex differences results in a delay in the development of lethal graft-v-host disease (GVHD). In this study, a total of 1 to 2 X 10(7) nonadherent cells (740 to 1560 CFUs [colony-forming units]) from three-day-old cultures were used as a source of donor marrow. Three strain combinations were evaluated; LP/J into C57BL/6; BIO.BR into CBA/J; and C57BL/6 into LP/J. Donor mice were immunized with recipient spleen cells prior to culture in order to increase the graft-v-host response. For LP/J marrow into C57BL/6 mice, 5 X 10(7) donor spleen cells transplanted along with the marrow were needed to induce lethal GVHD. However, lethal GVHD was seen without the addition of spleen cells for BIO.BR into CBA/J and C57BL/6 into LP/J strain combinations. Most animals receiving fresh marrow were dead of GVHD five weeks after transplantation. With the use of cultured marrow the three-month survival was 80%, 51%, and 93%, respectively, for LP/J into C57BL/6, BIO.BR into CBA/J, and C57BL/6 into LP/J strain combinations. Long-term donor engraftment in all recipient animals receiving cultured marrow was confirmed by analyzing hemoglobin polymorphisms between the strain combinations. These results demonstrate that in contrast to transplantation across major histocompatibility complex differences, the use of cultured cells for bone marrow transplantation across minor histocompatibility complex differences allows for engraftment while reducing the risk of lethal GVHD.
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3896343
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Cryostatic sections of rat large bowel tumors induced by 1,2-dimethylhydrazine were stained with monoclonal antibodies against different proteins of intermediate filaments: (a) against prekeratin (mol. mass 49 000, PK49) found in many epithelial cells and (b) against vimentin, a constituent of intermediate filaments of mesenchymal cells. Immunofluorescence study showed that large bowel tumor cells as well as normal cells of this organ contain PK49 but not vimentin. High sensitivity of the method allowed one to clearly identify small invasive nodules and groups of tumor cells not visible in usual histologic preparations. Moreover, in some cases single atypical tumor cells were identified in tumor stroma and in the submucosal layer underlying the tumor, that were indistinguishable from normal mesenchymal cells at the light microscopy level.
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3896346
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The alpha-thalassemic mouse has a hereditary microcytic anemia, almost certainly has a shortened RBC life span, and is a potential candidate for cell replacement therapy. In a routine study of bone marrow repopulating capacity using hemoglobin as a cell marker, normal donor marrow cells, but not alpha-thalassemic donor marrow cells, completely replaced the host cells. Further analysis showed that at least 30 times more alpha-thalassemic cells were required to outcompete normal donor cells injected simultaneously. The results were more extreme then expected and suggested a defect in a stem cell population as well as in the RBCs. Evidence that the multipotent and erythroid-committed stem cells in alpha-thalassemic mice are not decreased was shown by CFU-S and CFU-E assays. The combined results indicate that the deletion expresses itself most conspicuously in the RBC population. Tests were also performed to analyze repopulation kinetics in the Hbath-J/+ mice. In unirradiated alpha-thalassemic hosts, the hemoglobin from a normal donor persisted but did not replace the host hemoglobin. Sublethally irradiated alpha-thalassemic hosts, on the other hand, were easily repopulated with normal cells. We conclude that the alpha-thalassemic mouse is a good model for cell replacement therapy.
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3896347
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The monoclonal antibodies (MoAb) T101, G3.7, 35.1, and TA-1 were conjugated to intact ricin using a thioether linkage. These MoAb detect, respectively, the CD5[gp67], CD7[p41], CD2[p50], and [gp95, 170] determinants that are found in the vast majority of cases of T cell acute lymphocytic leukemia (T-ALL). The resulting immunotoxins (ITs) and an equimolar mixture of these ITs were evaluated as potential purgative reagents for autologous transplantation in T-ALL. Leukemic cell lines were used to compare the kinetics of protein synthesis inactivation mediated by each IT. The cells were treated with IT in the presence of lactose in order to block the native binding of ricin. The observed rates of protein synthesis inactivation correlated with target antigen expression detected by fluorescence-activated cell sorter analysis. Of the four ITs, T101-ricin (T101-R) exhibited the fastest rate of inactivation, followed in order by G3.7-ricin, TA-1-ricin, and 35.1-ricin. At concentrations greater than 300 ng/mL, a cocktail containing an equimolar amount of all four ITs (referred to as the four-IT cocktail) exhibited kinetics that were as fast or faster than those of T101-R. The long-term cytotoxic effects of individual ITs and the four-IT cocktail were evaluated using a sensitive clonogenic assay. Each IT was specifically cytotoxic and inhibited 1 to 4 logs of clonogenic leukemic cells at doses (300 to 600 ng/mL) that can be used clinically. The four-IT cocktail was highly cytotoxic; a concentration of 300 ng/mL inhibited greater than 4 logs of leukemic cells while sparing the majority of committed (CFU-GM, CFU-E) and pluripotent (CFU-GEMM) hematopoietic stem cells. The determination of both short-term kinetics of protein synthesis inactivation and longer-term inhibition of clonogenic growth allowed new insight into cell killing by IT. Our results suggest that ITs continue to act on clonogenic target cells for a period of three to five days. Interestingly, the four-IT cocktail was not as potent against clonogenic leukemic cells as T101-R alone, although it exhibited kinetics of protein synthesis inhibition that were as fast as those of T101-R alone. This finding suggests that internalized ITs may differ in the length of time they remain active within the cell. Our results also demonstrate the importance of using several different assays to evaluate IT reagents.
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3896348
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We report results of a pilot study designed to evaluate the effects of in vitro depletion of T lymphocytes from donor marrow in patients receiving HLA-identical marrow grafts for treatment of hematologic malignancies. Twenty patients aged 31 to 50 years were prepared for transplantation with cyclophosphamide (120 mg/kg) and fractionated total body irradiation (12.0 or 15.75 Gy). All received cyclosporine after grafting. The donor marrows were treated with a mixture of eight murine monoclonal antibodies and rabbit serum complement in a manner that achieved a 2- to 3-log depletion of T cells in most patients. Initial engraftment occurred promptly in 19 of the patients, and only three had clinically significant acute graft-versus-host disease. Depletion of donor T cells, however, was associated with an increased incidence of graft failure, which occurred as late as 244 days after transplantation. Graft failure was transient in one patient but apparently was irreversible in seven others. Three of the seven patients had cytogenetic but not morphological evidence of leukemic relapse at the time of graft failure. All seven patients with irreversible graft failure have died, six after receiving second bone marrow transplants. Seven of the eight cases of graft failure occurred among the 11 patients prepared for transplantation with 12.0 Gy of total-body irradiation, and only one occurred among the nine patients with advanced malignancies who received 15.75 Gy of total-body irradiation. This association with irradiation dose suggests that host factors were partly responsible for the graft failures. Because graft failure seldom occurs in irradiated recipients of unmodified HLA-identical allogeneic marrow transplants, it appears that T cells in the donor marrow may serve a beneficial function in helping to maintain sustained engraftment possibly by eliminating host cells that can cause graft failure. Optimal application of in vitro manipulation of donor marrow as a method for preventing graft-versus-host disease will require more effective immunosuppression of the recipient in order to assure sustained engraftment and function of donor stem cells.
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3896351
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In order to study the posttransplant evolution of serum immunoglobulin levels, we measured serum IgG, IgA and IgM levels in 50 recipients of allogeneic bone marrow before transplantation and at different intervals thereafter (days 39, 120, 365 and 730). IgG and IgM levels were depressed for 1 year and IgA levels for 2 years posttransplant. Immunoglobulin deficiency was more severe and prolonged in patients with graft versus-host-disease. Hypogammaglobulinemia may contribute to the frequent infections observed in these patients, especially those with chronic graft-versus-host disease.
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3896352
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Chromosomal and molecular biologic studies of human breast cancer are beginning to provide insight into the basic biology of this important disease. The current state of knowledge of both cytogenetic evaluation and assessment of expression and amplification of cellular oncogenes in breast cancer will be outlined in this brief review.
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3896353
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A multi-institutional randomized clinical trial was carried out to evaluate the effect of vincristine (V) added to cyclophosphamide, methotrexate, 5-fluorouracil, and prednisone (CMFP) for the treatment of metastatic breast cancer. There were 427 patients entered into the study and randomly assigned to one of the two treatments, i.e. the five drug therapy CMFPV or the four drug therapy CMFP. The differences in patient survival and tumor response between the two treatment groups were not statistically significant. The data were also analyzed using multivariate procedures to determine those factors ascertained at entry into the study which were predictors of survival or predictors of response to therapy. The one factor that predicted both response and survival was performance status. An additional important predictor of survival was sites of metastatic involvement. Other significant predictors of response were menopausal age, BUN, and hematocrit.
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3896354
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As part of a multi-centre study on tinnitus maskers, a controlled study with random allocation of patients to treatment groups was performed. The two therapists subdivided the patients according to whether or not they experienced hearing difficulties in addition to their tinnitus. Those with no hearing difficulties were randomly assigned to a control group with no instrumental treatment, or to treatment with one of two types of masker. Those with hearing difficulties were assigned to hearing aid, combination instrument, or masker treatment. No significant differences were found between treatment groups for those with no hearing difficulties. The differences between treatment groups for those fitted with maskers were small, but tended to indicate increased benefit derived from maskers. A number of interesting inter-therapist effects were found.
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3896355
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This report describes a three-centre study of the effectiveness of tinnitus maskers, combination instruments (masker plus hearing aid), and hearing aids in the management of tinnitus. Some 472 patients entered the study with 382 reaching the first evaluation session after a minimum period of 6 months from fitting, and 206 reaching the second evaluation not less than 6 months after the first. The study included two control groups, by which to assess the comparative benefit to be derived solely from the investigation and counselling of such patients. The principal results were as follows: thorough investigation and careful counselling do much to help the patient; much further benefit is given by tinnitus masking instruments of various kinds; maskers are more often effective than hearing aids, although the latter are frequently the most appropriate first treatment of those patients who have substantial (but not yet treated or insufficiently treated) hearing difficulties as well; there is no evidence of masking having any harmful effect on hearing. None of the audiometric or tinnitus tests currently employed can be regarded as predictive, either of tinnitus severity, or of the eventual outcome of masking therapy, however certain measurements may help as a guide to patient management.
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3896356
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Because medical school is a logical place for information retrieval capabilities to be introduced to future physicians, a survey was conducted at the Pritzker School of Medicine of the University of Chicago in August 1984 to determine the students' awareness and use of MEDLINE. The study found that many students were unaware of MEDLINE and its capabilities, and that the MEDLINE orientation for students during the first week of medical school was inadequate. Suggestions for improving the orientation were solicited from the students, and these have been analyzed and discussed.
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3896357
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Fielding H. Garrison's paper "The medical periodical and the scientific society" cited the Buffalo Medical Journal in the company of eminent periodicals published in Berlin, Boston, and Edinburgh. This article provides an overview of the Journal and places it in context of 19th-century medical journalism. The Journal is assessed in terms of original scientific contributions and as a source of social and local history.
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3896362
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Pressor responses to exogenous arginine vasopressin were assessed in adult rats that had been treated neonatally with capsaicin or its vehicle. Measurements were made under control conditions, after inhibition of baroreflexes (with pentolinium), and after inhibition of baroreflexes (with pentolinium) and the production of angiotensin II (with captopril). Resting arterial blood pressures and pressor sensitivities to exogenous arginine vasopressin were similar in capsaicin-treated and vehicle-injected rats. Sixty minutes after the administration of pentolinium, systolic and diastolic blood pressures were reduced in both groups of rats and the pressor responses to arginine vasopressin were similarly and significantly enhanced. In both groups of rats 60 min after administration of pentolinium and captopril, systolic and diastolic blood pressures were lower than in the presence of pentolinium alone, but pressor responses were not different from those seen in control conditions. The possibility that the present results are explicable in terms of baroreflexes, the renin-angiotensin system and endogenous vasopressin interacting to influence the pressor sensitivity to exogenous vasopressin is discussed. From the present findings, it seems that our previous observation of impaired, vasopressin-mediated blood pressure recovery following acute hypotension in capsaicin-treated rats cannot be attributed to a reduced pressor sensitivity to the hormone.
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3896363
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The vasomotor responses of individual cerebral pial arterioles on the convexity of the cerebral cortex to subarachnoid perivascular micro-injections of dopamine and the putative dopamine receptor agonists, apomorphine, SKF 38393 and LY 141865, have been examined in 38 anaesthetized cats. The perivascular microapplication of dopamine (10(-9)-10(-3)M) effected dose-dependent reductions in pial arteriolar calibre, with the maximum reductions in calibre (22 +/- 2% from preinjection levels: mean +/- s.e.) being observed at 10(-3)M. The cerebrovascular constriction produced by dopamine (10(-5)M) could be significantly attenuated by the concomitant perivascular administration of phentolamine (10(-6)M) or methysergide (10(-6)M). The perivascular microapplication of apomorphine (10(-8)-10(-4)M) effected dose-dependent increases in arteriolar calibre, with the maximum increase (31 +/- 6%) being observed with apomorphine (10(-5)M). The perivascular administration of the putative dopamine D1-receptor agonist, SKF 38393 (10(-9)-10(-4)M) increased arteriolar calibre, with the maximum response (24 +/- 3%) being observed with injection of 10(-7)M. The putative dopamine D2-receptor agonist, LY 141865, also increased cerebral arteriolar calibre, but only at high concentrations (maximum calibre increase 25 +/- 6.1 with 10(-4)M). The cerebrovascular dilatations elicited by apomorphine and by SKF 38393 were markedly attenuated by the concomitant perivascular microapplication of the putative dopamine D1-receptor antagonist, SCH 23390 (10(-8)M). The perivascular administration of SCH 23390 (10(-9)-10(-5)M) per se did not alter arteriolar calibre nor the arteriolar dilatation provoked by microinjections of acidic cerebrospinal fluid. These results point to the presence on cat cerebral arterioles of dopamine receptors (probably of D1 subtype) mediating dilation.
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3896365
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9 beta-Methyl carbacyclin (9 beta Me; ciprostene) is a synthetic, chemically stable analogue of prostacyclin (PGI2; epoprostenol). The platelet anti-aggregating and cardiovascular effects of 9 beta Me have been compared to PGI2 in anaesthetized monkeys and dogs. In addition, their haemodynamic effects have been compared in open-chest anaesthetized dogs and conscious dogs. Intravenous infusion of 9 beta Me and PGI2 to the anaesthetized monkey resulted in a dose-dependent hypotension, tachycardia and inhibition of ex vivo ADP-induced platelet aggregation. 9 beta Me was 72 times less active than PGI2 both as a hypotensive and anti-aggregating agent. Intravenous infusion of 9 beta Me and PGI2 to the anaesthetized beagle dog resulted in a qualitatively similar haemodynamic profile. Thus both substances induced a dose-dependent hypotension accompanied initially by a slightly increased heart rate, a dose-dependent increase in cardiac output, stroke volume and an increased peak LV dP/dt. At the higher doses studied, the initial increases in the parameters measured were succeeded by dose-dependent falls. 9 beta Me was 76 times less active than PGI2 as a hypotensive agent. In the anaesthetized greyhound, a dose-dependent anti-aggregating and hypotensive effect was seen with either drug, with 9 beta Me being 23 and 40 times less active than PGI2, respectively. Intravenous infusion of 9 beta Me and PGI2 to the conscious beagle dog induced a dose-dependent hypotension and a variable effect on heart rate. 9 beta Me was 33 times less active than PGI2 as an hypotensive agent. The duration of the hypotensive response induced by 9PMe was not significantly different from that induced by PGI2 in either monkey or beagle dog.
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3896364
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The effects of some agonists on isolated preparations of guinea-pig ileum, atria and bronchial muscle have been compared with those of carbachol. The concentrations producing comparable responses were used to estimate the equipotent molar ratio relative to carbachol. Arecaidine propargyl ester was 4 to 5 times as active as carbachol on the ileum but more than 10 times as active as carbachol on atrial rate or atrial force, so the results confirm that this compound has a 2 to 3 fold selectivity for receptors in atria. Ethoxyethyltrimethylammonium iodide was one-quarter to one-third as active as carbachol on ileum but only one-tenth as active as carbachol on atrial rate or atrial force and so shows a 3 to 4 fold selectivity for receptors in ileum. The other compounds tested, which included acetylcholine, methacholine, n-pentyltrimethyl-ammonium iodide and bethanechol showed less selectivity. There were no obvious differences between effects on atrial rate and effects on atrial force, though with esters it was often difficult to obtain effects on atrial rate in the absence of an inhibitor of cholinesterase. Activity on bronchial muscle was generally similar to activity on ileum.
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3896366
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The function of 18 human kidney grafts was studied before and 3 months after autotransplantation without prior bench surgery on the parenchyma or the vessels. Kidney protection was accomplished by pre-treating the patient with mannitol and low molecular weight dextran solution and flushing the kidney with a Xylocaine-heparin mixture and cold Sacks' II solution. The mean cold ischaemia time was 239 min (range 140-345 min). The glomerular filtration rate (GFR) remained unchanged post-operatively in terms of both total and split kidney GFR. Proximal and distal tubular integrity, as studied by determination of beta2-microglobulin excretion and concentration ability respectively, was also preserved.
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3896367
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A method of measuring residual urine volume using ultrasound is described. The volume is computed from serial parallel sections of the bladder. This method is found to be significantly more accurate than previously reported techniques and is quick and easy to perform.
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3896368
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This study was undertaken to analyse the results in 192 patients who 3 to 4 years earlier had undergone transurethral resection (TUR) in a controlled clinical trial on the value of a short peri-operative course of antibiotics. The survival rate was comparable in both groups. Most deaths were due to cardiovascular disease and/or cancer of the prostate and the gastrointestinal tract. Infectious events predominated in the control group and more antibiotics were prescribed for these patients during follow-up than for the patients in the peri-operative antibiotic group. Bacteriuria was found in 24% of patients, evenly distributed between the groups. Eighty-three per cent were satisfied with the results of prostatectomy but 38% complained of symptoms from the lower urinary tract. The maximum urinary flow rate was not influenced by the presence of bacteriuria and/or symptoms. There was no difference between the groups regarding mortality or morbidity except for the frequency of post-operative urethral stricture formation, which was significantly higher in the controls. It was concluded that prospective long-term follow-up is indicated to assess the effect of short peri-operative antibiotic courses.
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3896369
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Serial transrectal needle biopsies were taken from 146 patients (657 specimens) with advanced prostatic cancer (T3/T4, M1/MO) admitted to a trial of two forms of oestrogen therapy. Histological grading by Gleason and Mostofi techniques on the initial biopsy showed no correlation either with extent of disease or its eventual outcome on treatment. Change in grade was dissociated from the response of bone metastases to hormone treatment and did not appear to influence survival. However, the prognosis of 16 patients showing clearance of tumour from their serial biopsies was generally good.
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3896373
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Using a Clark oxygen electrode and a 133Xe clearance technique, tissue oxygen tension (T02) and blood flow have been determined in the small and large bowel of a rabbit experimental model. The predictive value of perianastomotic T02 in colonic anastomoses was determined, healing being assessed by leakage rate, tensile strength and hydroxyproline content. The effect of suture technique on colonic perianastomotic T02 has also been studied. Colonic and small intestinal T02 correlated with blood flow (r = 0.93). Basal colonic blood flow and oxygen tension were significantly lower than in the small intestine (P less than 0.01). Interrupted and continuous suture techniques decreased colonic perianastomotic T02, although mean T02 in the continuous group was significantly lower than in the interrupted group (P less than 0.01). The leakage rate was 10 per cent (1/10) for anastomoses constructed with a perianastomotic T02 above 55 mmHg compared with 100 per cent (10/10) if less than 25 mmHg (P less than 0.001). Perianastomotic T02 correlated with breaking energy (P less than 0.001), breaking strength (P less than 0.01) and hydroxyproline content (P less than 0.05).
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3896372
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One hundred and eighteen patients undergoing low colorectal anastomoses were randomly allocated to reconstitution by either single layer interrupted extramucosal sutures or circular staple gun. In the 60 patients undergoing sutured anastomosis there were 2 (3 per cent) clinical leaks and 4 (7 per cent) radiological leaks, and no failures. Of the 58 patients who underwent stapled anastomosis there were 4 failures, 7 (12 per cent) clinical leaks, 14 (24 per cent) radiological leaks and 1 death. Stapled anastomoses were more than ten times as expensive as sutured anastomoses and there were no savings in time or numbers of associated colostomies. An interrupted extramucosal suture technique remains the ultimate standard for low colorectal anastomosis.
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3896390
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The immunocytochemical localization of the enzyme choline acetyltransferase (ChAT) was examined in the guinea pig organ of Corti to determine if both lateral and medial systems of efferents would show immunoreactive labeling for this specific enzyme marker of cholinergic neurons. Cochleae were also examined after lesion of efferents to determine if ChAT-like immunoreactivity is confined to efferents. ChAT-like immunoreactivity was seen in the inner spiral bundle, tunnel spiral bundle and by the bases of inner hair cells corresponding to the lateral system of efferents. ChAT-like immunoreactivity was also seen in crossing fibers and puncta at the bases and by the nuclei of outer hair cells corresponding to the medial system of efferents. With the use of video enhanced contrast microscopy more than 9 ChAT-like immunoreactive puncta at the bases of outer hair cells could be resolved. In cochleae examined 6 weeks after ipsilateral lesion of efferents, no ChAT-like immunoreactivity was observed. These results add strong evidence that acetylcholine is a transmitter of both the medial and lateral systems of efferents.
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3896389
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Opiates, morphine and [D-Ala2-D-Leu5]-enkephalin (DADLE), inhibited the K+-stimulated release of cholecystokinin (CCK) from the hypothalamus of both Zucker obese (fa/fa) and lean (Fa/-) rats, in vitro. Morphine and DADLE did not inhibit the K+-stimulated release of CCK from frontal cortex from either strain. The opiates did not affect basal efflux of CCK and their effects were all blocked by equimolar concentrations of naloxone. These studies indicate a regional specificity for the effect of opiates on CCK release, and may provide evidence for a cellular mechanism by which endogenous opiates modulate feeding behavior.
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3896392
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Vasopressin-and neurophysin-immunoreactive cells have recently been demonstrated in the rat locus coeruleus (A6) and subcoeruleus (A7). Using consecutive 5 microns thick frozen sections, medium-sized cells throughout the locus coeruleus area, but predominantly in the posterior parts of the A6 displayed coexistence for vasopressin and noradrenaline or neurophysin and noradrenaline immunoreactivity. The putative projection areas of putative fibers from vasopressin-containing cells in the locus coeruleus still remain to be elucidated.
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3896391
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We have estimated the number of dentate granule cells in Sprague-Dawley and Wistar rats at 1, 4 and 12 months of age. In Sprague-Dawley rats the number of granule cells is relatively constant throughout this period at about 1 million. In Wistar rats, on the other hand, there is a progressive increase in the number from about 700,000 at 1 month to 1 million at 4 months; thereafter the number declines to about 800,000 at 1 year. Estimates of the numbers of cells in the polymorphic zone that can be stained immunohistochemically for somatostatin, cholecystokinin, vasoactive-intestinal peptide, and glutamic acid decarboxylase show no appreciable differences in the two strains.
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3896393
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Acute insulin stress increased plasma catecholamine levels in both the Syrian hamster and albino rat within 3 h after an intraperitoneal injection of either 5 or 10 units of insulin. In the rat, this stress caused a concurrent increase in pineal serotonin N-acetyltransferase (NAT) activity and melatonin content with no observable change in hydroxyindole-O-methyltransferase (HIOMT) activity. In the hamster, on the other hand, acute insulin stress did not alter pineal NAT activity, but depressed both HIOMT activity and melatonin content up to 3 h after the stress. These results present further evidence that catecholamines do not control hamster pineal melatonin synthesis by the same mechanism as observed in the rat.
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3896394
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Angiotensin II (AII)-immunoreactive cell bodies were found in all parts of the paraventricular nucleus of the hypothalamus (PVH) in the normal, colchicine-treated rat. The greatest concentration of cells was found in the posterior part of the magnocellular division of the nucleus, while scattered cells were found in all 5 parts of the parvocellular division. In comparison, the Brattleboro rat showed similar cell staining in parvocellular parts of the PVH, although a substantial decrease in the number of AII-stained cells was found in the magnocellular division. In the normal animal, fiber staining was evident in both laminae of the median eminence. This immunostaining was selectively enhanced in the internal lamina following water deprivation, and was selectively enhanced in the external lamina following adrenalectomy. The Brattleboro rat was similar to the normal animal with regard to staining of the external lamina, but, consistent with the diminished number of immunoreactive magnocellular neurons, little immunostaining in the internal lamina was detected. Unilateral lesions of the PVH selectively diminished staining of fibers and varicosities in the ipsilateral external lamina, while bilateral lesions virtually eliminated staining on both sides. The findings in the Brattleboro rat indicate that specific subpopulations of both parvocellular and magnocellular neurons in the PVH contain an antigen that is immunologically similar to synthetic AII and unrelated to vasopressin or its prohormone.(ABSTRACT TRUNCATED AT 250 WORDS)
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3896396
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No specific function has been ascribed to the high gonadotropin-releasing hormone (GnRH) content of the organum vasculosum lamina terminalis (OVLT). The objective of this study was to determine whether levels of GnRH within the OVLT are altered during cyclic gonadotropin secretion. GnRH levels were determined at various times during an estrogen/progesterone (E/P)-induced LH surge. Groups of E/P and sesame oil-treated animals were decapitated at 12.00 h, 14.00 h, 16.00 h, 18.00 h, and 22.00 h following the P or oil treatment. Morphological localization, as well as quantitation of immunoreactive GnRH within discrete regions of the brain was achieved by combining unlabeled antibody immunocytochemistry with computerized image analysis. Analysis of GnRH levels in the OVLT revealed that at any of the 5 times examined, there was: (1) no significant difference among controls, (2) no significant difference among E/P-treated animals, and (3) no significant difference between E/P-treated versus control animals. In contrast, ME GnRH levels in E/P-treated rats showed the expected decrease prior to the onset of the LH surge. These findings suggest that the level of GnRH detected in axon terminals within the OVLT cannot be related directly to the serum LH status of ovariectomized, E/P-treated rats. It is therefore possible that GnRH within the OVLT might function in a neuromodulatory role, rather than as a direct regulator of cyclic gonadotropin secretion.
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3896395
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An antibody to des-pyroglutamyl ranatensin (RT 2-11) has been prepared and has been used to histochemically and biochemically identify ranatensin-like immunoreactivity (irRT) in the rat brain. The most most prominent stained cell group was situated in the dorsal tegmental pons. Areas of immunoreactive fibers were found in the ventral hippocampus, septal area and the hypothalamus. A similar distribution was found by radioimmunoassay data. The distribution of irRT was compared to that of bombesin-like immunoreactivity (irBN). The two peptides have different though partly overlapping distributions. Gel filtration of brain extracts show that the molecular size of irRT is similar to that of synthetic RT. However, HPLC characterization of irRT indicated that the immunoreactive material is different from synthetic RT and also different from irBN and irGRP. These results indicate the presence of two separate peptide systems, one RT-like, the other BN-like, in the mammalian CNS.
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3896397
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The development of specific markers for retinal ganglion cells is an area of great interest in retinal research. In this study we report on a monoclonal antibody (AB5) which specifically labels ganglion cells in rabbit, cat and monkey, as well as a variety of other mammalian species. Labelling of ganglion cells was also observed in isolated cell preparations of rabbit retina.
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3896398
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Dissociated fetal rabbit brain cells were grown on petri dishes coated with collagen. Culture medium consisted of Dulbecco's Modified Eagles Medium plus 10% serum. The mitotic inhibitor 1-beta-D-arabinofuranosylcytosine was added at 6 days for a 2 day period to inhibit over-growth by glial cells and fibroblasts. In some cases cultures were chronically exposed to 0.5, 1.0 or 2.0 microM betamethasone. Examination of cultures by phase microscopy and acetylcholinesterase (AChE) staining demonstrated that cultures incubated with 1.0 and 2.0 microM betamethasone contained 2-2.5 times as many neurons as compared to control cultures. Furthermore, there was an increase in the specific activities of both AChE and choline acetyltransferase (ChAT) which were proportional to the increase in neuronal cell numbers obtained from phase microscopy and AChE staining. These results suggested that betamethasone enhanced survival of cholinergic neurons. Cultures were also examined for neuron specific gamma-aminobutyric acid (GABA) uptake. Again GABA uptake was approximately 2-2.5 times as great in cultures incubated with 1-2 microM betamethasone when compared to controls. Thus, the increase in GABA uptake paralleled the increase in neurons observed by phase microscopy and AChE staining, suggesting that the survival effect of betamethasone was not specific to cholinergic neurons. While betamethasone treated cultures always contained greater numbers of neurons the percentage of neurons lost from all cultures after 2 weeks was the same.(ABSTRACT TRUNCATED AT 250 WORDS)
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3896399
|
Using an antibody against GABA, neurons within the guinea pig hindbrain, midbrain and forebrain auditory nuclei were identified which demonstrate GABA-like immunoreactivity. GABA-positive cells were localized in the cochlear nucleus, superior olivary complex, lateral lemniscus, inferior colliculus, and medial geniculate body. GABA-positive terminals could be seen surrounding globular and spherical cells in ventral cochlear nucleus and principal cells in medial nucleus of the trapezoid body. In addition, numerous positive, punctate terminals appeared throughout the hindbrain auditory nuclei and, although fewer in number, in midbrain and forebrain auditory nuclei.
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3896400
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Primary cultures of the 21 day foetal rat brain contain a cohort of astroblasts that concertedly acquire glial fibrillary acidic protein (GFAP) filaments between the 16th and 18th hour after plating. This burst of cytoskeletal differentiation is not observed in cultures initiated from the 18 day foetal brain and is not effected by the addition of cytosine arabinoside, an inhibitor of glial cell proliferation.
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3896402
|
Intracerebroventricular microinjection of endotoxin in mice resulted in powerful hypoglycemia. The effect was reproduced by the biologically active moiety of endotoxin, lipid A, and prevented by coadministration of the polycationic peptide antibiotic polymyxin B (PMB) or by detoxification of endotoxin by means of mild alkaline hydrolysis. Central treatment with PMB also attenuated the hypoglycemic response to systemic administration of endotoxin or lipid A. These results suggest a direct role of the CNS in the mechanism of endotoxin hypoglycemia.
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3896403
|
Histamine is widely distributed in various mammalian tissues and it has been shown that histamine is located in mast cells as well as in other structures. Biochemical evidence has been presented that histamine acts as a neurotransmitter in the central nervous system. Immunohistochemical studies have demonstrated the location of histamine-immunoreactive neuronal cells in both the central and peripheral nervous system. Biochemical studies have shown that histamine is present in the adrenal gland, while the location of histamine in the adrenal medulla is not known. There is pharmacological and biochemical evidence that exogenous histamine affects the catecholamine secretion of the adrenal medulla. The present study was undertaken to examine the location of histamine in the rat adrenal medulla by an indirect immunofluorescence method using a specific histamine antiserum. We now report the presence of histamine-immunoreactive endocrine cells in the adrenal medulla of the rat and suggest that histamine is located in the noradrenaline-secreting cells.
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3896401
|
The effect on cholinergic neurons in the basal nucleus of exposing the cortex to excitotoxic amino acids was examined in the rat. Kainic or N-methyl-D-aspartic acid were applied extradurally over the cerebral cortex of one side. This resulted in a severe depletion in the numbers of neurons in the underlying cortex. The immunohistochemically identified cholinergic neurons of the ipsilateral basal nucleus showed a significant shrinkage, -31% of their mean cell area, which was comparable with the retrograde degeneration seen following direct mechanical damage of the cortex. These findings suggest that cholinergic neurons of the basal nucleus can undergo transneuronal retrograde degeneration.
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3896404
|
L-Histidine decarboxylase [L-histidine carboxylyase, HDC, EC 4.1.1.22] is an enzyme distinct from L-DOPA decarboxylase [L-aromatic amino acid carboxylyase, DDC, EC 4.1.1.28]: the two decarboxylases from fetal rat liver were completely separated from each other by DEAE-cellulose column chromatography and by affinity chromatography with L-carnosine as a ligand. The antibody raised against this HDC inhibited the HDC's from rat and guinea-pig brains very strongly, but their DDCs very weakly. However, in immunofluorescent histochemical studies, the antibody cross-reacted with DDC-like immunoreactive structures, such as chromaffin cells of the adrenal medulla, the raphe nucleus, the substantia nigra, and the locus coeruleus of the brain of guinea-pigs, but not of rats, suggesting that these two decarboxylases share some antigenic structures.
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3896405
|
The technique of principal-component analysis was used to define anatomically the semicircular canal planes of the rhesus and squirrel monkeys with respect to the stereotaxic coordinate system. The analyses were performed on a series of points obtained from the dissected osseous labyrinths. A planar equation was defined for each canal plane in the stereotaxic coordinate system and angles were calculated between the 3 ipsilateral canal planes, between synergistic canal pairs and between each canal plane and the stereotaxic planes. The data from both species are similar: the ipsilateral canal planes are nearly orthogonal; synergistic pairs of canal planes are approximately parallel with angles of 2 degrees-12 degrees between pairs in the rhesus monkey and 13 degrees-16 degrees between pairs in the squirrel monkey. The horizontal canal planes form angles of 22 degrees and 18 degrees with the horizontal stereotaxic plane in the rhesus and squirrel monkeys, respectively. A head position of 15 degrees (pitch nose-down) was calculated to produce an optimal head position in both species for maximally stimulating the horizontal canals and minimally stimulating the vertical canals during horizontal angular acceleration. The radii of curvature (R) of the horizontal, anterior and posterior canals were also measured for both species using a calibrated reticle. These measurements indicate that the anterior canal of both species has the largest radius of curvature. This anatomical information is discussed in relation to the available physiological data.
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