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3894420
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We have examined the relationship between insulin-induced receptor downregulation and the induction of a postreceptor defect in the insulin-stimulated glucose transport system in rat adipocytes, and found that downregulation was linked to the expression of the postreceptor defect. When recycling of insulin receptors was inhibited by 20 mM Tris, insulin pretreatment (100 ng/ml) for 4 h at 37 degrees C induced both net loss (65%) of cell-surface receptors and a 63% decrease in maximal insulin responsiveness. In contrast, when cells were treated with insulin alone for 4 h at 37 degrees C so that receptors could recycle, or treated at 16 degrees C with Tris plus insulin to inhibit receptor internalization, neither receptor downregulation nor a postreceptor defect was observed. Induction of the postreceptor defect was specific for insulin under conditions when downregulation would occur, since treatment of cells with Tris and the insulin mimicker spermine did not result in receptor loss or the postreceptor defect. Other experiments revealed that receptor downregulation occurred first without loss of insulin responsiveness, but, once the postreceptor defect appeared, its severity was correlated to the degree of further receptor loss, as a function of insulin dose and exposure time. Tris (20 mM) alone acutely decreased maximally stimulated glucose transport rates slightly (22%), but this effect was rapidly reversible after Tris removal and could not have been directly responsible for the lasting and profound postreceptor defect seen after pretreatment with insulin plus Tris. Taken together, these data suggest that insulin-induced receptor loss is linked to the induction of the postreceptor defect. The postreceptor defect was due to an inability to maximally increase the maximum velocity of glucose transport. Furthermore, the expression of the postreceptor defect depended upon the extent to which the glucose transport system was allowed to deactivate; maintaining the glucose transport system in an activated state prevented its expression. Thus, the mechanism could involve rapid inactivation or sequestration of glucose transporters during deactivation such that they become refractory to the subsequent stimulatory effects of insulin. In conclusion, (a) insulin does not acutely induce a postreceptor defect in the glucose transport system of adipocytes without loss of cell-surface insulin receptors; (b) the defect in stimulated glucose transport has been induced distal to the insulin receptor via a mechanism linked to receptor loss; and (c) the postreceptor lesion is due to decreased number of intrinsic activity of glucose transporters on the cell-surface in the presence of a maximally effective insulin concentration. These data suggest that insulin receptor downregulation and postreceptor defects in insulin action, which frequently co-exist both in vivo and in vitro, may be linked mechanistically.
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3894422
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The bare lymphocyte syndrome is a disorder in which class I histocompatibility antigens fail to be expressed normally on the surface of lymphocytes. Utilizing complementary DNA probes for both beta 2-microglobulin and class I genes, the molecular basis for this syndrome was investigated in a family with two siblings exhibiting the bare lymphocyte syndrome. Southern blot analysis demonstrated no gross internal defect in either class I or beta 2-microglobulin genes. Northern blot analysis of class I and beta 2-microglobulin messenger RNAs also revealed no qualitative difference between affected and unaffected family members. In contrast, quantitation of both class I and beta 2-microglobulin transcripts demonstrated each to be decreased in patients when compared to controls. Moreover, the decrease in both transcripts was coordinate. These results suggest that the bare lymphocyte syndrome may represent a pretranslational regulatory defect of both class I and beta 2-microglobulin gene expression.
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3894423
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A brief period of starvation (2-3) depletes the hepatic glycogen stores but results in only a limited reduction of the muscle glycogen depots. In this situation insulin resistance contributes to the glucose intolerance, but it is not known which tissue or tissues are responsible for the decreased insulin sensitivity. The present study was therefore undertaken to examine the influence of a 60-h fast on insulin sensitivity in splanchnic and peripheral tissues in normal humans. Euglycemic (95 mg/dl) 1-mU insulin and hyperglycemic (215-225 mg/dl) glucose clamp studies were conducted for 2 h in overnight (12 h) and prolonged (60 h) fasted nonobese subjects. Splanchnic exchange of glucose and gluconeogenic precursors was measured using the hepatic vein catheter technique. During the euglycemic clamp, insulin infusion resulted in similar steady state insulin levels in 60-h and 12-h fasted subjects (73 +/- 7 vs. 74 +/- 5 microU/ml). Total glucose disposal was reduced by 45% after 60 h of fasting (4.0 +/- 0.3 vs. 7.6 +/- 1.1 mg/kg per min, P less than 0.05) and the splanchnic glucose balance reverted from a net release in the basal state (12 h fast, -1.7 +/- 0.2, and 60-h fast, -0.9 +/- 0.1 mg/kg per min, P less than 0.01) to a net uptake during the clamps that was similar after 60 h and 12 h of fasting (0.6 +/- 0.1 vs. 0.6 +/- 0.2 mg/kg per min). During the hyperglycemic clamp, insulin levels rose rapidly in all subjects. In the 12-h fasted group this rise was followed by a further gradual one, reaching significantly higher values than in 60-h fasted subjects during the second hour (67 +/- 15 vs. 25 +/- 2 microU/ml, P less than 0.05). Total glucose disposal was lower, though not significantly so, after the 60-h fast (2.6 +/- 0.4 vs. 5.4 +/- 1.3 mg/kg per min, 0.05 less than P less than 0.10), and as with the euglycemic clamp, the splanchnic glucose balance was altered from a basal net release to a net uptake during the clamp (1.3 +/- 0.2 vs. 1.1 +/- 0.2 mg/kg per min). After an overnight fast, splanchnic lactate uptake fell and the arterial lactate concentration rose in response to both hyperglycemia and hyperinsulinemia, whereas these variables were unchanged in the 60-h fasted subjects during both types of clamp studies.
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3894424
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One consequence of B-lymphocyte activation is immunoglobulin production, which can be quantitated by various techniques. We have compared assay of plaque forming cell (PFC) and determination of immunoglobulins by ELISA in culture supernatants of human lymphocytes stimulated with pokeweed mitogen and with Staphylococcus aureus. These assays correlated well (r greater than 0.77) in all major immunoglobulin classes studied. The close correlation suggests that determination of secreted immunoglobulins by ELISA may be substituted for the PFC assay.
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3894426
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This paper reports a non equilibrium competitive enzyme immunoassay method using enzyme-labeled antibodies, for the quantitation of melatonin in chloroform-extracted samples. Its principle is as follows: methoxytryptamine hemisuccinate-human serum albumin conjugate physically absorbed onto a polystyrene sphere and melatonin to be measured, compete for a limited and fixed amount of peroxidase-labeled anti melatonin IgG. After incubation and washings the enzymatic activity bound to the sphere was measured with a chromogenic substrate. This simple method can detect as low as 22 fm of melatonin and is fairly precise. We also present its application to the determination of melatonin in serum and pineal gland.
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3894425
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A biotin-avidin amplified enzyme-linked immunosorbent assay (ELISA) for the measurement of human IgA in serum, colostrum, gastric juice, and supernatants of in vitro mitogen-stimulated human peripheral blood mononuclear cells is described. The ELISA reproducibly detects as little as one nanogram of IgA in a fifty microliter sample (20 ng/ml).
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3894427
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Heat-treatment of proteins from human sera and bovine serum albumin caused an increase in their binding to microplates in a temperature-dependent manner. Quantitative data were obtained for 125I-labelled human IgG, with binding of up to 400 ng of 56 degrees-treated IgG per untreated well. However, only a minor increase in available antibody activity of adsorbed rabbit antibody was found upon pretreatment at 56 degrees. The increased binding to microplates as a result of pre-incubation at raised temperatures was by high pressure liquid gel permeation chromatography demonstrated to be accompanied by polymerization. Inhibition of the direct binding of the proteins to plastic surface was achieved most efficiently by coating with non-interfering proteins followed by non-ionic detergent (Tween 20), which should also be present in the wash buffer.
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3894430
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An enzyme immunoassay technique based on the direct detection of Chlamydia trachomatis antigen in urethral or cervical swabs was used for the rapid diagnosis of chlamydial genital infection. Urethral and cervical samples from 140 patients were tested in parallel by enzyme immunoassay and cell culture using iodine staining. The direct test had a sensitivity of 92.5% and specificity of 97.2% when compared with the cell culture system. The enzyme immunoassay technique provides a rapid and simple method for diagnosing chlamydial genital infection and may be performed on a large number of samples in laboratories which do not have tissue culture facilities or a trained microscopist.
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3894429
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A simple, sensitive enzyme linked fluorescence immunoassay has been developed to detect IgM antibodies against Chlamydia trachomatis. Reticulate bodies and elementary bodies from C trachomatis L2/434 Bu strain were isolated and used as antigens in the assay. Of 113 serum samples obtained from infants with pneumonia, 27 (23.9%) had IgM antibodies to C trachomatis L2 reticulate bodies and nine (8.0%) had IgM antibodies to C trachomatis L2 elementary bodies (titre greater than or equal to 1/500). Specific IgM antibodies were not detected in 20 control serum samples obtained from healthy adults and children. The possible use of enzyme linked fluorescence assay to determine IgM antibodies in the serodiagnosis of C trachomatis infection is discussed.
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3894431
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Fifty jejunal biopsy specimens obtained from normal subjects and from untreated and treated patients with coeliac disease were assessed blindly by three independent observers, each of them using different morphometric techniques-namely, linear measurement, stereology, and computer aided microscopy. In two of 26 control biopsy specimens linear measurement was not possible because of distortion of villi. Highly significant (p less than 0.001) correlation coefficients were found between the different techniques. With all methods significant differences between controls and patients with coeliac disease and between treated and untreated coeliac patients were found. Only by stereology, however, was there no overlap between results for patients and those for controls. In view of the limitations of linear measurement and the high cost and complexity of computer aided microscopy, we propose that a simple stereological technique using an eyepiece graticule is the method of choice in the quantitative assessment of mucosal architecture in jejunal biopsy specimens.
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3894432
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Two immunofluorescence procedures to evaluate antinuclear antibodies were compared in a series of 221 patients with chronic liver disorders of various aetiologies. The use of HEp-2 cells allowed us to discriminate with more confidence between the homogeneous and speckled patterns, to show the presence of associated patterns in the same serum, and, above all, to identify two specificities, unrecognizable on tissue sections. The anticentromere antibody was found in 10% of cases of primary biliary cirrhosis and occasionally in other conditions; the antibody staining multiple nuclear dots was strictly confined to primary biliary cirrhosis (17%). With the exception of autoimmune chronic active hepatitis the prevalence of antinuclear antibodies increased in all groups, particularly in primary biliary cirrhosis. Homogeneous antinuclear antibody was associated by both immunofluorescence procedures with autoimmune chronic active hepatitis. The multiple nuclear dot antinuclear antibody turned out to be an additional marker of primary biliary cirrhosis, helpful for the positive diagnosis of primary biliary cirrhosis in a proportion of cases negative for antimitochondrial antibody. Absorption experiments showed that multiple nuclear dot and antimitochondrial antibody are antigenically distinct. Moreover, multiple nuclear dot antinuclear antibody was associated with the finding of a dry Schirmer's test.
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3894434
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The present study was performed to determine whether the healing of periodontal intraosseous defects could be improved through the combined use of citric acid conditioning of the root surfaces and grafting of autogenous intraoral cancellous bone. 28 proximal defects in 19 patients were treated surgically including acid conditioning of the root surfaces. Another 25 defects in these patients were treated with acid conditioning combined with osseous grafts using the maxillary tuberosity areas as donor sites. Both therapies, e.g., citric acid conditioning alone and acid conditioning combined with osseous grafting resulted in approximately 1 mm gains of probing attachment and probing bone levels. Within the parameters of this study, osseous grafting did not enhance the effect of citric acid conditioning alone. Limited improvement of the treated defects of the present study was obtained in spite of the use of supplementary regenerative techniques.
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3894435
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Since Actinobacillus actinomycetemcomitans appears to be a key etiologic agent in localized juvenile periodontitis, this study determined the effectiveness of different treatment modalities in suppressing A. actinomycetemcomitans in localized juvenile periodontitis lesions. A total of 25 deep periodontal lesions from 7 patients with localized juvenile periodontitis were included in the study. The test periodontal lesions either received scaling and root planing alone, scaling and root planing together with soft tissue curettage, or modified Widman flap surgery. Subgingival A. actinomycetemcomitans were enumerated using selective culturing. Clinical measurements included changes in probing periodontal attachment level, probing periodontal pocket depth, gingival index, plaque index, and digital subtraction of standardized serial radiographs. The microbiological and clinical effects of treatment were monitored over a period of 16 weeks. All periodontal lesions studied demonstrated high numbers of A. actinomycetemcomitans prior to treatment. Scaling and root planing alone did not markedly change the subgingival A. actinomycetemcomitans counts, nor any of the clinical parameters studied. In contrast, soft tissue curettage as well as modified Widman flap surgery suppressed A. actinomycetemcomitans to undetectable levels immediately after therapy in more than 80% of the lesions studied. A total of 5 periodontal lesions exhibited gain of probing periodontal attachment after subgingival curettage or Widman flap treatment; 3 of these sites revealed no detectable A. actinomycetemcomitans, and the remaining 2 sites harbored only low levels of A. actinomycetemcomitans. 5 periodontal lesions which lost probing attachment after treatment all demonstrated high numbers of subgingival A. actinomycetemcomitans. Changes in alveolar bone, assessed by digital subtraction of serial radiographs, correlated with changes in probing periodontal attachment level, confirming the clinical results. The present study revealed a close relationship between post-treatment A. actinomycetemcomitans levels and the clinical response to treatment, which supports the concept that A. actinomycetemcomitans is an important organism in the etiology of localized juvenile periodontitis. This study also showed that a substantial suppression of subgingival A. actinomycetemcomitans cannot be achieved by periodontal scaling and root planing alone, but can be accomplished by surgical removal of periodontal tissues.(ABSTRACT TRUNCATED AT 400 WORDS)
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3894436
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64 sites with probing pocket depth greater than or equal to 6 mm from 11 patients were treated with plaque control instruction and one episode of root planning. Subsequently, selected sites in each patient were irrigated with either chlorhexidine, tetracycline, saline or served as non-irrigated control sites. Irrigation immediately followed instrumentation, and was repeated every 2 weeks for 24 weeks. Healing was monitored at 8, 16, and 24 weeks clinically and at 7, 15, and 23 weeks with subgingival washings for determination of % as well as total number of spirochetes. The following changes were apparent from comparing pooled site means at 24 weeks with pretreatment data: (1) bleeding sites decreased from 62 of 64 sites initially to 22 of 64 at 24 weeks; (2) spirochetes decreased from 34% to 2%; (3) probing pocket depths decreased from 7.6 to 4.7 mm; (4) probing attachment levels showed a gain of 1.2 mm. The improvement of the chlorhexidine and tetracycline irrigated sites was similar to that of the saline irrigated and non-irrigated control sites. Thus, biweekly chlorhexidine, tetracycline or saline irrigation of deep pockets did not appear to augment the effects of non-surgical periodontal therapy.
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3894437
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Fluoxetine hydrochloride, a new antidepressant, was administered to 10 obsessive-compulsive patients, and the effects of treatment were examined in a single-blind placebo design. The effects of fluoxetine were examined with respect to depressive symptomatology and obsessions and compulsions per se. The results suggest that fluoxetine affected depressive symptoms but also had an effect on self-reported measures of obsessions and ritualistic behavior. Results are discussed in terms of improvement in obsessive-compulsive disorder, the relation of improvement to initial levels of depression, and patients' ability to tolerate the drug.
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3894438
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This article reviews the available evidence regarding the incidence of tongue thrust swallowing and the possible relation between this deglutition pattern, tongue tip position at rest, and sigmatism. It is found that tongue thrust swallowing a) is the rule rather than the exception in children under 10 years of age, b) is not correlative with low tongue tip position at rest, c) is not closely linked up with dental malocclusion, and d) does not prevent, but may delay, the acquisition of correct sibilant articulation.
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3894439
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The CT findings in two patients with the unusual presentation of malignant lymphoma in the skull are described. The dominant CT findings were contrast enhanced large soft tissue masses without calcifications on both sides of the bone with very little or no changes in the bone itself. This characteristic CT appearance may be helpful to differentiate primary lymphoma of the skull from other bone tumors and osteomyelitis.
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3894441
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The ability to distinguish between pleural and peritoneal fluid is important in the management of patients with peridiaphragmatic fluid collections. The differentiation of subphrenic fluid from pleural effusion by CT may be difficult and requires a detailed understanding of the normal appearance of the diaphragm on transaxial images. We report 12 patients in whom peridiaphragmatic fluid collections could potentially be misinterpreted as peritoneal rather than pleural fluid. In all cases the presence of subsegmental, basilar atelectasis with subpulmonic fluid created confusing CT images. Subsegmental atelectasis formed a curvilinear band at the lung base that simulated the hemidiaphragm. Fluid anterior to the atelectasis caused a false impression of subdiaphragmatic (peritoneal) fluid. Computed tomography through the upper abdomen excluded intraabdominal fluid in all cases. In four cases ultrasonography confirmed fluid in a supradiaphragmatic, subpulmonic location, excluded peritoneal fluid, and identified subsegmental atelectasis. The presence of subpulmonic fluid and subsegmental atelectasis requires meticulous interpretation of transaxial CT images to avoid the incorrect localization of peridiaphragmatic fluid collections.
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3894446
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A teat dip containing 1.94% linear dodecyl benzene sulfonic acid and 12% glycerine, an anionic detergent formulation, was evaluated in two field trials on a commercial dairy. In Trial 1, the teat dip was compared to an undipped control in a split-herd design. Incidence of infection with Streptococcus agalactiae was reduced 57.8%; infections with presumptively identified Staphylococcus aureus were not reduced. Milking machine function and milking procedures may have affected teat dip effectiveness and incidence of udder infection. Streptococcus agalactiae was eradicated prior to Trial 2 in which the detergent teat dip was compared to a 1% iodophor product of proven efficacy. Incidence of Staphylococcus aureus infection was 40.5% lower in the detergent than in the iodophor group. Taxonomic studies on Staphylococcus species indicated that presumptive microbial identification resulted in erroneous conclusions concerning efficacy of the teat dip products. Importance of speciation of staphylococcal isolates is discussed.
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3894445
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Gonadotropin-releasing hormone administered at breeding enhances fertility of dairy cows, so a study was designed to evaluate the mechanism for enhanced fertility following administration of gonadotropin-releasing hormone at first postpartum breeding. Twenty-four cows were assigned randomly to one of two treatments, 100 micrograms of gonadotropin-releasing hormone intramuscular or saline vehicle intramuscular at insemination. Blood samples for luteinizing hormone assay were taken at 2-h intervals prior to breeding and .5-h intervals for 3 h after insemination. Composite morning milk samples for progesterone assay were collected for 30 days after insemination or until next estrus. Cows given gonadotropin-releasing hormone had higher luteinizing hormone concentrations in blood serum following treatment than cows given saline, 13.2 versus 3.0 ng/ml. There was no relationship between luteinizing hormone and subsequent conception. Progesterone for cows that became pregnant was higher throughout sampling days. Mean progesterone concentrations were 4.6 versus 2.2 ng/ml in pregnant and nonpregnant cows during the first 4 days after insemination. Cows treated with gonadotropin-releasing hormone that conceived had higher progesterone than other cows, and that was evident at the first 4 days postbreeding.
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3894442
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The CT and ultrasound findings in a case of an adrenal pseudocyst are reported. The pathology, etiology, usual manifestations, and differential diagnosis of adrenal cysts are discussed.
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3894447
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In dairy cows, two distinct and important aspects of the interrelationship between stray voltage problems on the farm and dairy cow productivity can be identified. One is behavioral modification that increases in intensity when currents associated with neutral-to-earth voltages above .7 V find a pathway through the cow. The other is immediate endocrine response. Results of research are less clear on the current necessary for the latter to occur; it may require 8 mA or more. This implies, depending on the pathway and the cow's pathway resistance, that voltage difference between two cow contact points must exceed 3 V. Resistance of different cow pathways range from 350 to 1700 omega. Milk production is more likely to be affected adversely when cows are subjected to shock patterns both intermittent and irregular. Less than 10% of the dairy cow population are thought to perceive any electrical currents upon contact with conductive grounding equipment provided voltages on the farm electrical neutral system remain below .35 V. This paper also identifies various sources of stray voltage problems and discusses appropriate procedures for correction.
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3894448
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Animal environment is affected by climatic factors that include temperature, humidity, radiation, and wind. Extremes in climate alter energy transfer between the animal and its environment and can affect deleteriously reproduction. Seasonal variation of environment, nutrition, and management alters estrous activity and duration of estrus. Conception rates are reduced under stress of heat and cold. Endocrine functions are altered by climatic extremes. In hyperthermia, adrenal function is reduced, and this may allow the animal to cope with the environment because of the lower calorigenic actions of glucocorticoids. Estrogens are lower during the proestrus to metestrus period of the estrous cycle and during late gestation and appear to manifest their physiological actions through shorter duration of estrus and lower calf birth weights, respectively. Season alters endocrine profiles and influences fertility of males. Spermatogenesis is impaired, and testosterone is lower during early exposure to hyperthermia. Environmental modifications can alleviate stress of heat and cold to some extent. Experimentation using indices of environmental measures is needed to assess interactive effects of environment on reproduction.
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3894449
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Feed costs are, and will continue to be, the largest single expense for milk production. Gross efficiency of milk production is greater for high-producing cows because a lower proportion of total feed intake is used for maintenance of the cow. High milk production and high feed intake are positively correlated. The challenge for the future is to continue the remarkable progress in milk yield potential and increased feed efficiency realized in the recent past. Some areas of research that show promise for improving our knowledge and ability to feed cows for even greater efficiency include studies of energy metabolism, protein metabolism, voluntary feed intake, ruminal fermentation and fiber requirements, effects of growth hormone on milk production and animal metabolism, mineral nutrition, buffers, and vitamins. Practical studies on treatment and utilization of by-product feeds, manipulation of milk composition through nutrition, and continued development of better computer models for feeding and management decisions will have a significant effect on the efficiency and profitability of the dairy enterprise.
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3894440
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Three noninvasive imaging methods, CT, scintigraphy with 201TlCl and 99mTcO4-, and ultrasonography, were performed on 36 patients with chronic renal failure and secondary hyperparathyroidism. The patients subsequently underwent total parathyroidectomy and parathyroid autograft. The detection rates of the three methods for the 143 excised parathyroid glands were compared according to gland weight and location. Computed tomography detected 53.8% of all glands and 77.6% of 76 glands weighing more than 500 mg. Scintigraphy detected 51.0% of all glands and 77.6% of glands heavier than 500 mg. Ultrasonography detected 42.7% of all glands and 65.8% of glands heavier than 500 mg. The detection rate of upper glands was best with CT (53.5 and 87.9%): that of lower glands was best with scintigraphy (62.0 and 78.6%). Although the combination of the three methods diagnosed 66.4% of all glands and 89.5% of glands heavier than 500 mg, CT and scintigraphy, the best two combinations, visualized 64.3 and 88.2%.
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3894450
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Reproductive performance affects profit of dairy herds because it directly affects milk produced per cow per day, number of replacements produced, and rates of voluntary and involuntary culling. High producing cows will reproduce at a satisfactory rate if they are managed properly. There appears to be direct relationship between herd management and reproductive performance. Thus, reproductive performance and profit respond positively to improvements of rates of detection of estrus, improvements of rates of conception, and improvements of management of the periparturient cow. Pharmacological procedures are now available for controlling time of estrus and insemination in groups of cattle. It is feasible to limit the breeding period in a herd to 1 wk of each 3-wk interval. Primary benefits of controlled breeding are convenience and efficient use of labor for detection of estrus and insemination. Biotechnical procedures such as embryo transfer and insertion of specific genes may enhance rates of genetic improvement for important economic traits.
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3894451
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Relationships between animal health and economic efficiency were examined using data from genetic investigations and management studies. Genetic investigations have indicated that cows bred for high production do require more health care, but that increased costs for health care negate only a small fraction of the greater returns from cows that are genetically superior for yield traits. These same studies have identified age of cow and stage of lactation as important sources of variation in health care costs. Health care costs increase with age and are highest at parturition and immediately thereafter, and decrease to much lower levels as lactation progresses. Animal health issues considered from a management perspective were macro-environment (climate, housing, facilities), nutrition-reproduction complex, replacement management, mastitis and udder health, and herd health preventive medicine programs. Most advances in management of animal health were beneficial, but some are economical only for large herds. Improvement of udder health through continued and expanded research on milking procedures and equipment design is an area of unusual promise. Additional research appears needed to cope with stress and fatigue to legs and feet in modern facilities. Preventive medicine programs become more cost effective as herds become larger and should be used by a larger percentage of dairy producers. The economic efficiency of many management practices is uncertain due to a paucity of data. Animal scientists should plan to incorporate economic comparisons into much more of their research.
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3894453
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The periodontal ligaments from single human teeth were dissected free of the root surface and plated into culture dishes. In each case two populations of cells were obtained: fibroblasts and epithelial cells. These two populations were separated and grown in culture. The epithelial nature of the epithelioid-appearing cells was confirmed by staining for keratin, exclusively an epithelial cell protein.
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3894454
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Maturation ameloblasts of rat incisor teeth have smooth-ended and ruffle-ended apical membrane configurations. It has also been reported that maturation ameloblasts have several lateral membrane configurations. The purpose of this study was to determine the correlation between the modulations of lateral and apical cell membranes of murine incisor ameloblasts in the maturation stage of amelogenesis. Maxillary and mandibular incisors were dissected, demineralized, embedded in paraffin, sectioned and then de-paraffinized, and the enamel organs were prepared for scanning electron microscopy. Additional mouse and rat incisor enamel organs were fixed and teased apart during dehydration, then observed in the SEM. The lengths of smooth- and ruffle-ended ameloblast segments were measured, and the site, length, and frequency of each lateral membrane configuration were determined within each segment. The lateral membrane configuration with folds forming from 12 to 14 channels around the periphery of the cells was most predominant in both smooth- and ruffle-ended cells. Cells surrounded by from six to eight channels were the only other lateral membrane configuration observed in ruffle-ended ameloblasts. Smooth-ended ameloblasts had lateral membrane configurations with either dense or sparse microvillous projections in addition to both types of channel cells. The observation that channelled extracellular spaces are always associated with ruffle-ended cells suggests that channels somehow function in conjunction with the ruffled apical membrane in resorption and removal of enamel matrix proteins. The smooth-ended ameloblasts lack tight apical junctions, and their microvillous lateral membranes permit the passage of plasma fluids around cells to the maturing enamel surface.(ABSTRACT TRUNCATED AT 250 WORDS)
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3894452
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A wax bite impression can serve as a reliable identification of missing and unknown children, particularly in the absence of caries and restorations. Dental crown heights in bite impressions made from noncontoured and contoured wax wafers were compared in ten patients, ranging in age from three to eight years. The contoured wax wafer produced significantly greater crown heights in the casts which were fabricated from it. The differences were most pronounced in the anterior teeth; but generally true for all the teeth.
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3894455
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The creep rates of six alloys for porcelain-fused-to-metal (PFM) restorations were determined as a function of flexural stress and temperature. Although two Pd-Cu alloys demonstrated excellent resistance to creep at low-stress, high-temperature conditions, they were especially susceptible to deformation at high stresses and temperatures near the glass transition temperature of dental porcelains. In comparison, a Ni-Cr alloy and a Pd-Co alloy demonstrated superior creep resistance at high-stress, low-temperature conditions. This indicates a relatively low potential for deformation due to stresses which may result from a thermal contraction differential between these two alloys and incompatible dental porcelains.
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3894467
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This paper is based on a study which investigated the perceptions and expectations held by nominated nurse experts from Hong Kong, concerning the future developments of nursing education in the local context. A modified Delphi survey method was utilized to gain a consensus of opinion regarding the leadership role that the Hong Kong Polytechnic's newly established Nursing Studies Section should play. The findings suggested that the present plans proposed by the section were inadequate and in juxtaposition with the expectations held by nursing education experts working in this field. The respondents indicated that the section should take total responsibility for post-basic nursing education, nursing research activities, curriculum development in association with the hospital schools of nursing and assisting clinical staff in the development of clinical and management practice.
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3894468
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A content analysis of 141 articles on breast feeding by discipline revealed differences in the factors considered necessary for breast feeding success and in the criteria used to determine success. Whereas medical articles focused on maternal factors prenatally and infant health post-natally, or the length of time breast feeding was maintained, lay articles focused on the relationship of the mother with her infant (the nursing couple) and the mother's ability to manage breast feeding within the family context. The implications of this discrepancy for nursing practice and research are discussed.
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3894470
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Using data from a randomized trial in health insurance, this paper examines the effect of cost sharing on use of dental services. The data come from a sample of the nonaged, noninstitutionalized civilian population of six urban and rural sites. We find that: reducing the level of cost sharing increases demand for dental services; and dental expenses rise 46% when the coinsurance rate falls from 95% to 0%, subject to a catastrophic limit on out-of-pocket expenses. Of this increase, two-thirds is attributable to an increase in the likelihood of visiting a dentist during the year. Moreover, there is a substantial surge in demand during the first year of more generous coverage. The first-year response to cost sharing is nearly twice the second-year response.
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3894473
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The role of prostanoids in a swine model of coronary artery spasm was examined. Eighteen miniature pigs underwent endothelial denudation of the left coronary artery (left circumflex branch in 14 pigs and left anterior descending branch in 4 pigs) followed by high cholesterol feeding. Three months after the denudation, when coronary artery spasm was repeatedly provoked along the denuded portion of the coronary artery by histamine, the vasoconstrictive effect of thromboxane A2 and the preventive effects of indomethacin and prostacyclin against histamine-induced coronary artery spasm were examined. Intracoronary administration of thiothromboxane A2, 200 micrograms, a stable thromboxane A2 analog, failed to provoke coronary artery spasm (seven of seven cases) but nonselectively constricted the coronary artery by 33%. Intravenous administration of indomethacin, 2 mg/kg, or continuous intravenous infusion of prostacyclin, 50 ng/kg per min, failed to prevent histamine-induced coronary artery spasm (four of four and eight of eight cases, respectively), yet the spasm was all but prevented by intravenous pretreatment with diphenhydramine at a dose of 1 mg/kg. Thus, in this swine model, prostanoids may not play a primary role in the occurrence of coronary artery spasm.
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3894474
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Maximal treadmill exercise testing at 1, 3 and 8 hours was used to assess the onset, duration and antianginal efficacy of the dihydropyridine slow channel calcium-blocking agent, nisoldipine, in an oral dose range of 5, 10 and 20 mg. A double-blind, randomized, placebo-controlled design was used involving 12 patients with stable effort angina. Exercise tolerance was significantly increased 3 hours after each dose, when the maximal beneficial effect occurred. The improvement was observed as early as 1 hour after the 10 and 20 mg dose, and persisted for 8 hours after the 20 mg dose. At 3 hours, the onset of an exercise-induced ST segment depression of 0.1 mV or greater was increased by 62 (p less than 0.05), 75 (p less than 0.01) and 117 seconds (p less than 0.01) with the 5, 10 and 20 mg dose of nisoldipine, respectively, compared with placebo. Similarly, time to onset of angina was significantly increased. The sum of exercise-induced ST segment depression at peak exercise was significantly decreased (p less than 0.05) from 8.7 +/- 2.3 to 6.7 +/- 1.8 and 6.4 +/- 2.0 mm, respectively, after the 10 and 20 mg dose of nisoldipine. The rate-pressure product was significantly greater with nisoldipine than with placebo at the onset of ischemia and at peak exercise (22.8 +/- 1.1 versus 20 +/- 1.4 X 10(3) U for the 20 mg dose; p less than 0.01). Thus, nisoldipine is an effective antianginal agent with a rapid onset of action that improves exercise tolerance, increases angina threshold and persists for at least 8 hours after oral dosing.
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3894475
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The automatic implantable cardioverter-defibrillator continuously monitors the heart, identifies malignant ventricular tachyarrhythmias and then delivers electrical countershock to restore normal rhythm. There are two defibrillating electrodes which are also used for waveform analysis; one is located in the superior vena cava and the other is placed over the cardiac apex. A third bipolar right ventricular electrode is used for rate counting and R wave synchronization. When ventricular fibrillation occurs, a 25 J pulse is delivered; when ventricular tachycardia faster than the preset rate is detected, the discharge is R wave-synchronized. The clinical evaluation study of this therapeutic method began in February 1980 in patients with recurrent refractory life-threatening ventricular tachyarrhythmias. So far, the device has been implanted in nearly 500 patients with a follow-up period of up to 59 months. The risks and complications associated with this treatment were found to be moderate. Actuarial analysis has demonstrated significant impact on the survival rate of the patients receiving implants with 1 year arrhythmic mortality rate reduced to 2% or less in all groups analyzed. The available data indicate that the automatic cardioverter-defibrillator can reliably identify and correct potentially lethal ventricular tachyarrhythmias, leading to a substantial improvement in survival in properly selected high risk patients.
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3894476
|
A 33 year old woman with chronic myelogenous leukemia presented with clinical symptoms and hemodynamic signs suggestive of pulmonary embolism. Initial angiographic studies supported the diagnosis of a massive saddle pulmonary embolus, and an inferior vena cava filter was inserted. However, subsequent autopsy revealed unsuspected angioinvasive pulmonary aspergillosis with secondary in situ thrombosis. The clinical features and diagnostic considerations in immunocompromised patients presenting with the clinical picture of pulmonary embolism are discussed.
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3894477
|
Eight normotensive obese subjects participated in an inpatient study designed to determine the effect of a constant sodium intake (150 mEq) on the renin-aldosterone axis during 12 weeks of weight reduction. Two 800-calorie (3,200 kj) ketogenic diets, differing in carbohydrate content (10 g vs 70 g) were used for the study. Supine and upright plasma renin activity (PRA) and serum aldosterone (SA) were determined at the baseline and every 4 weeks. Total body water (TBW) was determined by the tritiated water technique at the baseline and 12 weeks after dieting. Extracellular water (ECW) was determined by 77Br space. Routine serum chemistries were obtained at 2-week intervals. Analysis of variance indicated no significant differences in the PRA and SA between the two diets. At the baseline, while on a self-selected 150 mEq sodium diet, there was a 3- to 4-fold increase in PRA after 2 h of ambulation (supine PRA 0.83 +/- 0.22 increased to 3.41 +/- 0.96 ng/ml/h). After the hypocaloric diets were instituted, the absolute values for PRA in the supine and upright positions declined. However, the magnitude of the postural response (3- to 4-fold increase) remained unchanged during the 12 weeks of weight reduction. There was no decline in the absolute values for supine or upright SA, during the entire study. Weight loss was significant (from 102.56 +/- 6.0 to 81.7 +/- 3.7 kg; P less than .001) and was accompanied by a mean +/- SE reduction in the TBW of 3.01 +/- 0.88 liters (P less than .011).(ABSTRACT TRUNCATED AT 250 WORDS)
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3894478
|
We developed an ELISA by use of monoclonal anti-IgE to measure allergen-specific IgE. We measured perennial ryegrass (PRG) specific immunoglobulin E (sIgE) with conventional single incubations and with the recently reported transfer method to decrease interference in the assay. Paired sera in 10 patients before and during immunotherapy with PRG extract were analyzed for PRG sIgE with single serum incubations and with the sum of five serial serum incubations. A standardized reference serum and patient sera were incubated 12 hours and then transferred to a second well, incubated 12 hours more, and transferred again. The process was repeated until five pairs of wells had been incubated with each serum dilution. Color was developed, and optical density was measured. PRG sIgE was calculated by interpolation from the reference curve. Evidence of interference was inferred when less PRG sIgE was detected by single incubation than by transfer. Inhibition of 71.3% occurred in the sera drawn during immunotherapy. Inhibition of 32.9% was found before immunotherapy. Also, a late peaking of the well-to-well curve of optical density was observed in nine of 10 sera drawn during immunotherapy (the exception had not reached full strength), whereas all of the sera drawn before immunotherapy had normal curves. This suggests that sIgE determinations performed in microtiter plate format with single incubations will usually underestimate the sIgE level. This drawback needs to be kept in mind by the clinician interpreting the results of these assays.
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3894479
|
A monoclonal antibody (H4) against tryptase purified from human pulmonary mast cells was prepared and used as an immunoreactive marker for the cellular localization of tryptase in normal human skin and in lesional skin from subjects with systemic mastocytosis. Mast cells had characteristic metachromatic staining of cytoplasmic granules with Giemsa reagent and were detected in small numbers about superficial vessels in the papillary dermis of nonlesional skin and in large numbers about deep as well as superficial vessels of lesional skin. By both direct immunofluorescence with fluorescein isothiocyanate-H4 and indirect immunoperoxidase cytochemistry with H4, all mast cells were selectively stained. The reactivity was confined to the cytoplasm and was granular in character. In addition, keratinocytes in epidermal tissue and in cell suspensions stained diffusely with H4 antibody. A tryptase-like activity that cleaved tosyl-L-arginine methyl ester (0.003 U/10(6) cells) and was not inhibited by soy bean and lima bean trypsin inhibitors was detected in sonicated suspensions of purified epidermal keratinocytes. Monoclonal antitryptase antibody represents an immunologic probe for the presence of tryptase, a preformed mediator of human mast cells, in tissues and cells.
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3894480
|
Syringes used in intradermal skin testing have commonly been used for multiple patients. Recently the safety of this practice was questioned, raising the possibility that these syringes may transmit disease from one patient to another. Since this practice is so widespread and because of a scarcity of articles linking the spread of disease with this practice, we repeated these studies and performed other experiments to test this hypothesis. With the use of Escherichia coli, Staphylococcus aureus, and tritiated thymidine, we found contamination of syringe contents that indicated a clear potential for common syringes to spread disease. These studies and studies reported elsewhere suggest that common syringes should not be used in skin testing.
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3894481
|
This study evaluated the administration of albuterol syrup (0.1 mg/kg/6 hr) or placebo to 2- to 6-year old children whose extrinsic asthma was treated with maintenance theophylline in a prerandomized, double-blind crossover study design. Albuterol/theophylline treatment produced peak expiratory flow rates 2 hours after administration that were significantly higher than in the theophylline/placebo-treated group (119.3 L/min versus 83 L/min) p less than 0.01. The theophylline/placebo-treated group also required higher serum concentrations of theophylline to control wheezing, 10.5 micrograms/ml versus 5.0 micrograms/ml (p less than 0.01). The average symptom scores for the albuterol/theophylline-treated patients (72.5) were less than that of theophylline/placebo-treated group (97.6) p less than 0.02. Side effects such as tremor, irritability, or insomnia occurred in only two of 17 patients. Serial EKG recordings demonstrated no evidence of cardiotoxicity, such as arrhythmias, or indication of myocardial injury. The addition of albuterol to theophylline improved control of severe asthma in children 2 to 6 years of age demonstrated by improvement in pulmonary function, decrease in theophylline dosage requirement, and improvement in symptoms. It was free of any known cardiotoxicity.
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3894483
|
There appears to be a close interrelationship among airway responsiveness to mediators and to natural stimuli, the presence and severity of asthma, and endogenous mediator release in the airways. Histamine and methacholine have been most commonly used to measure airway responsiveness. Airway responsiveness to the two drugs is increased in patients with current symptoms of asthma, and the degree of increase relates closely to the degree of variable airflow obstruction and the therapy to control symptoms. The degree of airway responsiveness to histamine also correlates closely with the degree of responsiveness to methacholine and less closely with responsiveness to PGF2 alpha and to natural stimuli such as exercise and allergens. The less close correlations with responsiveness to exercise and allergens is probably because of variations in the ease and type of endogenous mediator release in the airways by these stimuli. Endogenous mediator release from a number of stimuli including allergens and ozone causes inflammation in the airways, asthma, and airway hyperresponsiveness. These various interrelationships indicate that the treatment of asthma should be directed to reduce airway responsiveness, prevent mediator release, and prevent or reverse inflammation.
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3894482
|
We have previously demonstrated that peanut oil is not allergenic to peanut-sensitive individuals. Seven soybean-sensitive patients were enrolled in a double-blind crossover study to determine whether ingestion of soybean oil can induce adverse reactions in such patients. All subjects had histories of systemic allergic reactions (urticaria, angioedema, wheezing, dyspnea, and/or vomiting) after soybean ingestion and had positive puncture skin tests with a 1:20 w/v glycerinated-saline whole soybean extract. Sera from six of the seven subjects were tested by RAST assay for the presence of specific IgE antibodies to soybean allergens. All patients had elevated levels of serum IgE antibodies to the crude soybean extract; binding values ranged from 2.3 to 28.1 times that of a negative control serum. Before the oral challenges, all patients demonstrated negative puncture skin tests to three commercially available soybean oils and to olive oil (control). On four separate days, patients were challenged with the individual soybean oils and olive oil in random sequence. At 30-minute intervals, under constant observation, patients ingested 2, 5, and 8 ml of one of the soybean oils or olive oil contained in 1 ml capsules. No untoward reactions were observed with either the commercially available soybean oils or olive oil. Soybean oil ingestion does not appear to pose a risk to soybean-sensitive individuals.
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3894486
|
Microwave-oven technology has been improved by the use of low power. With the utilization of low-power techniques, studies showed equal or better retention of nutrients for microwave, as compared with conventional, reheated foods for thiamin, riboflavin, pyridoxine, folacin, and ascorbic acid. Beef roasts microwaved at "simmer" were comparable with conventionally cooked roasts in sensory quality, while vegetables cooked by an institutional (1,150 w) microwave oven were superior to those cooked in a domestic (550 w) microwave oven. Microwave-cooked bacon had lower levels of nitrosamines than conventionally cooked bacon; however, the use of a new alpha-tocopherol coating system has been found to be a safe N-nitrosamine inhibitor regardless of cooking method used.
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3894488
|
Gilbert's probable screen memory of having been kidnapped, along with his persistent preoccupations with babyhood, remembering and forgetting, stress the intensity of his struggle against remembering the painful experiences from his childhood. His creative efforts function as an obsessional defense; they divert his attention from the experiences themselves to a fascination with the process of remembering and forgetting, while the painful affects are reversed into playful, good-natured humor. The results are some of his most treasured anecdotes. Watson (1918) quotes Gilbert's story of the amateur burglar who badly bungled an attempted robbery and ended up being arrested and jailed under the most humiliating circumstances. For years afterward, every time he though of the incident, he felt wretchedly uncomfortable, and he tried vainly to drive the occurrence from his mind. The story concludes with a statement which, remarks Watson, only Gilbert could have written: "Gradually one detail after another slipped from my recollection, and one lovely morning last May I found to my intense delight that I had absolutely forgotten all about it" (p. 94).
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3894491
|
The authors analyse the ultrasound aspects of normal and abnormal corpora lutea after reviewing the techniques for studying ovaries. The abnormalities include unruptured luteal follicles, cystic corpora lutea, haemorrhage into corpora lutea and ovarian hyperstimulation.
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3894495
|
A 65-year-old man presented with massive lower gastrointestinal tract hemorrhage. Minimal changes were noted on sigmoidoscopy, no bleeding lesions were identified on arteriography or red blood cell scan, and barium enema examination demonstrated only diverticular disease and minimal cecal deformity, interpreted as secondary to a recent appendectomy. Colonoscopy demonstrated multiple deep cecal ulcers. These were presumed to be due to an infectious etiology, since the stools were culture-positive for Salmonella typhimurium. The hemorrhage stopped within 24 hours of treatment with Ampicillin, Flagyl, and Gentamicin. The patient has remained well over a 12-month follow-up period. Repeat colonoscopy demonstrated healing of the cecal ulcers and there was also clearing of the Salmonella from the stools. This case report serves to remind us of the different methods used to diagnose lower gastrointestinal tract hemorrhage, and the importance of considering infectious causes of colitis.
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3894494
|
The efficacy of antacid in the treatment of benign gastric ulcer is less well established than in the treatment of duodenal ulcer. The objective of this study was to monitor ulcer healing and symptom relief in 38 patients with gastric ulceration treated for 6 weeks with cimetidine (Tagamet) 300 mg q.i.d. or an aluminum-magnesium containing antacid (Mylanta II) 10 ml q.i.d. (acid neutralizing capacity 203.2 mEq/day). The study was single-blind; the study physicians and those providing endoscopic assessments were not aware of the patients' treatment. Entered into the study were 19 male and 19 female patients ranging in age from 17 to 70 years, with a mean age of 52 years. None of the patients had taken cimetidine in the previous month, and none abused alcohol or nonsteroidal anti-inflammatory agents, but two-thirds of the patients were smokers. Five patients in the antacid group withdrew for numerous reasons including continued pain, noncompliance, and side effects. All patients in the cimetidine group completed the study, and no side effects were noted. There was no difference between the antacid- and the cimetidine-treated patients in the relief of symptoms. There was a significant difference in the 6-week ulcer healing between the groups, with 14/19 (74%) healed in the cimetidine group compared with only 6/14 (43%) healed in the antacid group (p less than 0.025). Thus, Mylanta II, 10 ml four times daily, is comparable to cimetidine 300 mg q.i.d. in the symptomatic relief of benign gastric ulceration, but ulcer healing was superior using cimetidine.
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3894498
|
Copper-zinc superoxide dismutase (CuZn SOD) has been localized in formalin-fixed rat tissues. Staining with a modified immunoenzyme bridge technique using the avidin-biotin-peroxidase complex revealed abundant endogenous CuZn SOD in cells that function in transporting ions, either cellularly, as in the case of tracheal, bronchiolar, and colonic epithelial cells, gastric oxyntic cells, and cells lining the salivary ducts and proximal convoluted tubules in the nephron, or intracellularly, as exemplified by skeletal muscle and neurons. Additionally, the enzyme was consistently demonstrable in hepatocytes, endocrine cells of the islets of Langerhans, and the highly membranous oligodendrocytes in the central nervous system. Cellular processes that maintain high ionic gradients appear especially vulnerable to the superoxide anion, thus necessitating the presence of CuZn SOD to scavenge toxic free radicals of oxygen. Comparison of these observations with other immunocytochemical reports indicates that the cellular distribution of CuZn SOD varies between different species.
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3894497
|
Gel-eluted bovine chromogranin (CG), the 75,000 dalton acidic protein abundantly present in adrenal chromaffin granules, was used as immunogen to prepare anti-CG serum. The specificity of the antiserum was demonstrated in immunoblots of electrophoresed bovine CG and in immunohistochemical studies of bovine adrenal medulla. In the immunoblots, the predominant immunoreactive band had a molecular weight of 75,000 daltons. Bands with a higher or lower molecular weight were also immunoreactive and may represent CG precursors or breakdown products. In the adrenal gland, only adrenal chromaffin cells contained CG immunoreactivity. Immunoblots and immunohistochemistry were also used to characterize the distribution of CG in bovine tissues. CG was expressed by cells of the diffuse neuroendocrine system (DNS) including: adrenal chromaffin cells, enterochromaffin cells, pancreatic islet cells, cells of the adenohypophysis, thyroid C cells, parathyroid cells, and submandibular gland. CG was also seen in four locations not previously recognized to express this antigen: thymic epithelial cells, neurons, the inner segment of rods and cones, and the submandibular gland. We demonstrate a wider distribution of CG than previously recognized and that the molecule detected in tissue by immunohistochemistry is indeed CG. We conclude that CG is expressed by neurons, cells of the DNS, and by a few other cells that may or may not be related to the DNS. The antiserum described here should prove valuable in developing an understanding of the function(s) of CG.
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3894499
|
Immunofluorescence microscopy of cultured animal cells is often performed after detergent permeabilization of formaldehyde-fixed cellular membranes so that antibodies may have access to intracellular antigens. A comparison was made of the ability of several detergents, after formaldehyde fixation, to affect localization of intracellular proteins or to permeabilize different organelles to antibodies. Saponin, a detergent-like molecule that can permeabilize cholesterol-containing membranes, was also used. Four monoclonal antibodies were found to have a bright, discrete fluorescence localization with saponin alone, but were almost undetectable when the cells were treated with nonionic detergents such as Triton X-100 or NP-40. These immunoglobulin G antibodies included two against lysosomal membrane glycoproteins, one against an integral membrane protein found in the plasma membrane and endocytic vesicles, and one against a membrane protein in the endoplasmic reticulum and the nuclear envelope. However, antigens localized in mitochondria and the nucleus required the use of a detergent such as Triton X-100 for their detection. The detection of a number of other membrane or cytoplasmic proteins was unaffected by Triton X-100 treatment. It was concluded that nonionic detergents such as Triton X-100 cause artifactual loss of detection of some membrane proteins, and saponin is a favorable alternative reagent for immunofluorescence detection of intracellular membrane antigens in many organelles.
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3894500
|
The resolution of indirect immunoperoxidase methods for localizing antigens on the surface of plasma membranes of cultured cells was tested using dissociated monolayer cultures of ciliary ganglion neurons prelabeled with cationic ferritin. Clusters of ferritin were produced on the cell surface by warming the cells to 37 degrees C after the ferritin, rabbit anti-ferritin, and goat anti-rabbit immunoglobulin coupled to horseradish peroxidase had all been applied. Intense 3,3'-diaminobenzidine tetrahydrochloride (DAB) staining was limited to the regions immediately surrounding the ferritin clusters. The lateral spread of the DAB reaction product beyond the outer ferritin particles in each cluster averaged 54-81 nm in four experiments. A second type of increased density, coinciding with the thickness of the plasma membrane, was also seen. These stained plasma membranes extended 161-339 nm from the ferritin clusters.
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3894501
|
A new conjugate for the detection of anti-trinitrophenyl(TNP) antibodies was developed to study the localization pattern of specific antibody containing cells and extracellular antibody in vivo. By means of a bridging molecule, poly-L-lysine, nine TNP groups and six horseradish peroxidase (HRP) groups were joined in one conjugate. Thus a higher specificity (more hapten) was united with a higher staining intensity (more enzyme) in the same conjugate. This conjugate made possible the simultaneous detection of anti-TNP antibody containing cells and establishment of their class (immunoglobulin M (IgM) and IgG). It was also used for the demonstration of anti-TNP antibodies in tissues where a TNP-alkaline phosphate (AP) conjugate could not be used due to high AP (endogenous) background staining. Thus we demonstrated anti-TNP antibody containing cells in gut associated lymphoid tissue and anti-TNP-(TNP-ovalbumin) immune complexes in the glomeruli of the kidney. We suggest that poly-L-lysine is a suitable bridging molecule for the preparation of hapten-HRP conjugates.
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3894503
|
A study was undertaken to obtain baseline information for future studies of H-antigen expression in urothelial tumors. The influence of ABO- and Lewis genes on H-antigen expression in human ureters was investigated. Thirty two ureters of different ABO- and Lewis types were stained by the Tween 20-modified immunoperoxidase staining technique using Ulex europaeus agglutinin I (32 cases) and two monoclonal anti-H antibodies (10 cases). Ureters from A and AB individuals were also stained using monoclonal anti-A and Dolichos biflorus agglutinin (14 cases). The H-antigen expression in endothelium of all cases and in urothelium of Lea-b+ and Lea-b- individuals was correlated to ABO blood type. H antigen was never detected in urothelium of Lea+b- individuals. Endothelial H-antigen expression was not influenced by the Lewis types. In A and AB individuals, urothelial and endothelial H- and A-antigen and Dolichos biflorus reactivities were mainly insignificantly related, with correlation coefficients ranging numerically from 0.10 to 0.72. The study stresses the importance of relating blood group antigen H expression in urothelial tumors to the ABO-, Lewis, and secretors types of the individual.
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3894504
|
An immunohistochemical method was developed to detect histamine in tissues. The aim of this study was to reveal the cellular stores of histamine in the gastrointestinal tract, pituitary, and adrenal gland. Histamine-containing nerve fibers were found in both rat and guinea pig gut. The origin of at least some of these fibers in the rat ileum was the submucous ganglion cell layer. In the rat stomach, numerous enterochromaffin-like cells exhibited histamine immunofluorescence, and endocrine cells in the ileum and jejunum contained histamine. Only mast cells contained histamine in the neurohypophysis. A large number of process-bearing cells in the guinea pig but not in the rat adrenal medulla contained histamine. The study shows that histamine is present in peripheral nerves and endocrine cells in addition to mast cells, and may function as a neurotransmitter or hormone.
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3894505
|
A specific monoclonal antibody against rat tissue kallikrein was used as the primary antibody for indirect immunoperoxidase staining of rat hypothalamus. Kallikrein was localized in the epithelial cells (ependyma) lining the third ventricle as well as in cell bodies of arcuate, supraoptic, paraventricular, and ventromedial nuclei.
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3894506
|
The cellular localization and regional distribution of peptides of the gastrin/cholecystokinin family was investigated in human fetal, neonatal and adult brains by use of immunohistochemical techniques. It could be revealed that a cholecystokinin-like immunoreactivity is already present in human brain at the 11/12th gestational weeks. With the 19th week a strong increase in number of CCK reactive cells and the reaction intensity is obvious. The data are compared with the distribution pattern of the adult brain. Our data permit to conclude that gastrin/CCK-related material might play roles independent of neurotransmitter functions during early human brain development.
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3894507
|
d-Tartrate dehydrase of Salmonella java is an oxygen-sensitive enzyme active in cultures incubated under the poorly aerated conditions of static culture but not in fully aerated shaken cultures nor on plates incubated aerobically. On plates of d-tartrate minimal agar incubated anaerobically the enzyme or the degradation products of d-tartrate are exported from d-tartrate-positive cells and are available to d-tartrate-negative bacteria. This may give misleading growth results when d-tartrate-positive and d-tartrate-negative strains are tested for growth on the same plate of d-tartrate minimal agar. The lead-acetate test terminated at 24 h, the 24 h turbidity test and the ability to grow on d-tartrate minimal agar within 48 h differentiated 53 S. paratyphi B strains that were negative in each of the three tests from 76 S. java that were positive in each of the tests. An intermediate group of eight strains utilized d-tartrate in Difco bacto-peptone water to give a positive lead acetate reaction at 2 days, were stimulated to a varying degree by d-tartrate in Oxoid peptone water within the same period of incubation and grew poorly on d-tartrate minimal agar. These latter strains may be deficient in a permease controlling uptake of d-tartrate or export of d-tartrate dehydrase. Inability to utilize d-tartrate is unlikely to be the single character accountable for the reputed enhanced pathogenicity of S. paratyphi B when compared with S. java. Indications for the existence of an enzyme, complementary to and mutually exclusive with d-tartrate dehydrase, that has a positive correlation with pathogenicity are discussed.
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3894508
|
Four thousand two hundred and forty six samples of retail processed food were examined for the presence of Escherichia coli. Overall 12% of samples contained this organism, cakes and confectionery being more frequently contaminated (28%) than meat and meat based products (9%). Contamination was more frequent in the summer months than in the colder weather and 27% of the contaminated foods contained greater than 10(3) E. coli/g. E. coli from meat and meat based products were more commonly resistant to one or more antibiotics (14%) than were confectionery strains (1%). The significance of these findings in relation to the E. coli population of the human bowel is discussed.
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3894509
|
Three of four extreme methods of immunization completely failed to protect mice against challenge with the homologous strain of Fusobacterium necrophorum. Unsuccessful vaccines included (1) broth culture killed by mild heat and emulsified with Freund's complete adjuvant, and (2) a homogenate of heavily infected mouse brains, inactivated by mild heat and given in two doses. Also unsuccessful as a method of immunization was the production of a severe subcutaneous infection with F. necrophorum, followed by curative treatment with metronidazole. Slight but significant protection against subcutaneous challenge resulted, however, from two such infections given in rapid succession. It would appear that the main virulence factors of F. necrophorum are only weakly immunogenic, and the experiments give little encouragement to the prospect of an effective necrobacillosis vaccine.
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3894510
|
Caecal samples from 350 Danish bacon pigs were investigated for salmonella using three methods of isolation. (1) Direct inoculation of 1 g of faeces into 10 ml of Muller-Kaufmann medium (MK medium) with addition of 0.3% Teepol 610 and subculture on Brilliant Green lactose sucrose phenol-red agar (BLSF agar) with 0.3% Teepol 610. (2) Pre-enrichment of 5 g of faeces into buffered peptone water with addition of 1% Teepol 610 followed by enrichment of 1 ml in 10 ml MK medium with 1% Teepol 610 and subculture on BLSF agar with 0.3% Teepol. (3) Incubation of 0.1 ml of the pre-enrichment (2) into 10 ml Rappaport-Vassiliadis medium (RV 10 medium) incubated at 43 degrees C, subculture on BLSF agar. The MK media with and without pre-enrichment yielded higher findings than the RV 10 media. In total, 28 (8%) of the pigs were found positive, representing 11 (7.4%) of a total of 142 herds investigated. Lymph glands were collected at a later date from six of the positive herds. Five of the herds were found positive. The number of salmonellas in the glands was low, probably less than ten per gram.
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3894512
|
I. I. Mechnikoff's contribution to various aspects of immunology is evaluated. The 25 years' struggle of this scientist for the existence of phagocytosis theory is briefly described. Works of I. I. Mechnikoff dealing with several factors of humoral immunity and cytotoxins are reviewed. The significance of I. I. Mechnikoff's studies providing analysis of immune processes in the phylogenetic sense as well as his ideas about the nervous system role in immunity processes is stressed.
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3894511
|
Four recently weaned pigs were dosed orally with oxytetracycline. This caused a rapid increase in the incidence of tetracycline resistance (TcR) among Escherichia coli isolates from the faecal flora. The isolates were differentiated further on the basis of O-serogroup, biotype and resistance pattern. There was no evidence that the administration of the antibiotic selected for a few TcR clones, but rather a relatively large number of TcR strains were identified during the dosing period. Using selective isolation media a proportion of these strains were demonstrated in the minority faecal Esch. coli flora before dosing, while the remainder were recognized for the first time after dosing commenced. The incidence of TcR among Esch. coli isolates also increased after weaning in other pigs which were not dosed with oxytetracycline or any other antibacterial agent. In a proportion of these animals this increase was associated with the dominance of a TcR enteropathogenic serotype (0149:K 91, K 88a, c) in the faecal Esch. coli flora which was probably ingested in small numbers before weaning. The source of other TcR strains was probably the environment in which each pig was placed after weaning.
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3894513
|
Oral administration of the angiotensin I-converting enzyme inhibitor captopril produced a substantial reduction of blood pressure in DOCA-salt hypertensive rats. After oral administration of captopril (30 mg/kg), mean blood pressure decreased from 172 +/- 11 to 148 +/- 9 mmHg (P less than 0.01) in one hour and its antihypertensive effects lasted for the next seven hours. Plasma vasopressin levels showed a marked elevation in DOCA-salt hypertensive rats compared with control values (22 +/- 5 versus 5 +/- 3 pg/ml). This increase in vasopressin was significantly reduced by captopril from 25 +/- 5 to 8 +/- 6 pg/ml. In addition, whole body vascular reactivity to norepinephrine was examined. Responsiveness was at first attenuated but returned to control value in spite of reduction of both plasma vasopressin and blood pressure. Thus, captopril reduces blood pressure in DOCA-salt hypertensive rats and the fall in blood pressure is accompanied by reduction of plasma vasopressin and attenuation of vascular reactivity.
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3894515
|
Twenty-nine patients with essential hypertension were studied while on their normal diets, on the 5th day of a high sodium diet (around 350 mmol/day) and on the 5th day of a low sodium diet (10 mmol/day). The fall in mean arterial pressure on changing from the high sodium to the low sodium diet was 9.0 +/- 1.6 mmHg and the rise in the plasma renin activity in the same period was 2.52 +/- 0.41 ng/ml/h, these two variables being significantly correlated (r = -0.45; P less than 0.02). An infusion of saralasin was given on the 5th day of the low sodium diet. A highly significant negative correlation was found between the fall in blood pressure on sodium restriction and the change in blood pressure with saralasin (r = -0.52; P less than 0.005); this correlation was still significant when corrected for the severity of the hypertension (r = -0.41; P = 0.03) while it became non-significant if controlled for plasma renin activity on the low sodium diet (r = -033; NS). These results provide direct evidence that the fall in blood pressure which is seen on reducing sodium intake in many patients with essential hypertension is, at least in part, directly mediated by the reactivity of the renin angiotensin system.
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3894516
|
Eighteen male Sprague-Dawley rats were fed a sodium-free diet and given NaCl (154 mmol/l) labelled with 22Na (37 Bq/l [1 microCi/l]) to drink. Following equilibration, each had a unilateral nephrectomy; 10 days later the animals started a series of 10 injections of deoxycorticosterone (12.5 mg twice-weekly for 5 weeks). Thereafter the animals were split into two groups, one to continue with DOC injections and diet as previously (DOC-salt), the other to stop DOC injections and continue a sodium-free diet and labelled saline of lower concentration (89 mmol/l) (post-DOC). During the period of DOC injections to both groups, blood pressure and exchangeable sodium rose significantly and were significantly correlated. In the post-DOC group, hypertension persisted and was not significantly different from that in the DOC-salt group. However, in the post-DOC-salt group, exchangeable sodium fell to levels similar to those found in uninephrectomized control animals of similar age which had never been given DOC or a high salt intake and had never been hypertensive. Thus an expanded sodium space does not contribute to maintenance of hypertension in the post-DOC-salt model.
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3894517
|
Regional blood flows were measured with radioactive microspheres in 35 conscious dogs at various times (between 1 h and 28 days) after creation of a stenosis of the descending thoracic aorta. Mean arterial pressure increased moderately proximal to the stenosis. Distally, arterial pressure decreased below control values immediately after stenosis, then returned gradually toward preconstriction values over 28 days. Plasma renin activity increased sixfold, after aortic constriction of 1 and 6 h, and remained significantly elevated for four days. Blood volume did not change significantly. In some of the vascular beds exposed to the elevated proximal pressure, significant increases in blood flow were noted in the early stages, mainly in the myocardium, the brain, the skeletal muscles and the bones. After 28 days, however, blood flows were significantly reduced in most tissues exposed to the proximal pressure. At this stage, vascular conductance was significantly decreased in the myocardium, the brain, the muscles, the skin and the bones as compared with a sham-operated control group. Several vascular beds perfused by the distal arterial pressure also showed a significant fall in flow after 28 days, notably the small intestine, the skin, the skeletal muscles and the bones. At that stage, vascular conductance was decreased in the small intestine, the muscles, the skin and the bones. Thus, aortic coarctation in dogs was characterized by a late generalized increase in vascular resistance extending to tissues which were never exposed to increased arterial pressure nor to an increased blood flow. These findings suggest that a systemic vasoconstrictor influence overrides local mechanisms in the control of regional circulations in coarctation hypertension.
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3894518
|
Lymphokine-activated killer (LAK) cells are demonstrable within 2 wk after syngeneic or allogeneic (H-2-compatible) bone marrow transplantation in mice. Classical cytotoxic T lymphocytes (CTL) are not active until at least 4 wk after transplant. Both LAK cells and CTL bear the Thy-1 marker and do not possess the murine natural killer cell marker asialo GM.
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3894519
|
In this study, we describe the isolation and characterization of My23, a human myeloid antigen defined by the monoclonal antibody (MoAb) AML-2-23. Cells of the HL-60 human promyelocytic cell line, when cultured in the presence of 1,25-dihydroxyvitamin D3 (calcitriol), express a surface protein of approximately 50 to 55 kilodaltons (Kd) which was immunoprecipitated with the AML-2-23 MoAb. Furthermore, after 2 days of exposure to calcitriol, HL-60 cells began to release My23 into culture medium, as determined by the ability of culture supernatant from these cells to block the binding of AML-2-23 to myeloid cells. My23 release was almost totally inhibited by incubation of cells at 4 degrees C, and was partially blocked by treatment of cells with cycloheximide or tunicamycin. The culture supernatant blocking factor, soluble My23, was identified as a 45 to 50 Kd protein by Western blot/immune overlay, using AML-2-23 and an 125I-labeled second antibody. My23, which was affinity-purified from culture supernatant, retained the ability to block AML-2-23 binding to myeloid cells. The affinity-purified antigen migrated on SDS-PAGE as a diffuse band in the m.w. range of 44 to 52 Kd. On treatment with endoglycosidase, the apparent m.w. of My23 decreased to approximately 40,000, indicating the presence of carbohydrate residues on My23. Serum from mice immunized with the purified antigen reacted with the same spectrum of myeloid cells as AML-2-23 MoAb, reacted with the My23 soluble protein in immunoblots, and competed with AML-2-23 for binding to myeloid cells. Binding of this antiserum to myeloid cells was blocked by cell supernatant from both monocytes and calcitriol-treated HL-60 cells, suggesting, along with results from m.w. determinations of the two preparations, that the soluble and cell surface forms of My23 are similar. Moreover, based on our finding that human plasma specifically inhibits the binding of AML-2-23 to myeloid cells, My23 may also be released in vivo. The enhanced expression of My23 on activated and more mature myeloid cells and its shedding or secretion by these cells is consistent with a functional role for My23.
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3894520
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In the present study we investigated some of the cellular mechanisms for the generation of macrophage-activating factor(s) (MAF) in immune responses to tumor antigens. C3H/HeN mice were immunized to syngeneic MH134 hepatoma or MCH-1-A1 fibrosarcoma by intradermal inoculation of viable tumor cells, followed by the surgical resection of the tumor. Spleen and lymph node cells from these tumor-immune mice were stimulated in vitro with the corresponding tumor cells, and supernatant from such a culture was tested for an ability to activate macrophages to exert their cytostatic and cytolytic activities as detected on tumor cells unrelated to immunizing tumors. Peritoneal adherent cells as a macrophage source, which were preincubated with supernatant from co-culture of tumor-unimmunized normal spleen and lymph node cells plus tumor cells, failed to exhibit any significant antitumor effect on unrelated X5563 tumor cells, whereas the addition of supernatant from cultures containing immune lymphocytes to adherent cells resulted in appreciably potent cytostatic and cytolytic effects on X5563 tumor cells, indicating the generation of MAF in culture supernatant. The activation of tumor-immune spleen and lymph node cells for MAF generation was tumor-specific, because anti-MH134- and anti-MCH-1-A1-immune lymphocytes produced MAF by the stimulation with the respective but not with the other alternative tumor cells. Such MAF production was abolished by treatment of tumor-immune spleen and lymph node cells with anti-Thy-1.2 or anti-Lyt-1.1 but not with anti-Lyt-2.1 antibody plus complement before culturing. These results indicate that the tumor-specific Lyt-1+2- T cell subset has a crucial role in generating MAF by which an adherent cell population as a source of macrophages acquires the potential for inducing a cytolytic as well as a cytostatic effect on tumor cells.
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3894521
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A micro enzyme-linked immunoassay (EIA) has been developed for the rapid and sensitive detection of either human or mouse monoclonal antibodies reactive with cell bound antigens. Whole intact cells are immobilized onto 96-well flat bottom microtiter plates by drying in an oven at 37 degrees C overnight prior to the start of the assay. This method of attachment was suitable for all cell types tested, regardless of origin, size and chromosomal content. The dried cells were then rehydrated, incubated with the appropriate test hybridoma supernatant, followed with subsequent analysis by EIA. The plates can be stored at 4 degrees C up to 1 month for future EIA analysis. This assay offers high sensitivity, requires only small amounts of target cells and test hybridoma supernatant, and can be completed within 3 h. This EIA is well suited for the rapid screening of large numbers of hybridoma supernatants and can also be adapted to include cells of any species, providing the appropriate antibody reagents are available.
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3894522
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Optimal conditions of culture and assay for identification of feline immunoglobulin-secreting mononuclear cells were determined for the staphylococcal protein A-reverse hemolytic plaque assay (SpA-RHPA). Hemolytic plaques were most distinct and numerous when peripheral blood mononuclear cells were stimulated with 6.9 micrograms/ml pokeweed mitogen for 7 days. Immunoglobulin-secreting cells were identified morphologically within a zone of hemolysis utilizing a 1:5 dilution of rabbit anti-cat IgG and a 1:30 dilution of guinea pig complement as developing reagents. The SpA-RHPA system should contribute to an understanding of normal feline T- and B-lymphocyte interactions and will likely aid in the identification and understanding of immune cell dysfunctions associated with chronic feline leukemia virus infection.
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3894523
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Pulmonary mast cells were obtained from guinea pig lung using a combination of enzymatic digestion of tissue, centrifugal elutriation, and density gradient centrifugation on Percoll. In the initial procedure, lung tissue was enzymatically digested with collagenase and elastase in four 30 min incubations. Typically, monodispersed cell suspensions contained 4% mast cells. Further purification of these lung mast cells using elutriation and Percoll gradients consistently yielded mast cells of 40-78% (mean 51%) purity. These cells were morphologically intact, viable and found to be functional as determined by histamine release evoked by antigen and anti-guinea pig IgG1 antibody.
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3894524
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Three different methods, [3H]uridine uptake, viable count and 51Cr-release were used to assess the intracellular survival of a strain of Candida albicans, 19321, which was lethal for mice injected intravenously. Intracellular survival 1 h after ingestion ranged from 50 to 80% depending on the method employed and the detergent used to lyse the phagocytes. Inhibition of uridine uptake by detergents used to lyse the phagocytes led to difficulty in assessment of intracellular killing by this method.
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3894525
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Soluble human plasma fibronectin or collagen types I or IV, when preincubated with tissue culture plastic dishes, were effective spreading agents for cultured human keratinocytes and increased spreading in a time-and concentration-dependent manner. Spreading on fibronectin, but not on type IV collagen, was inhibited by antifibronectin; therefore, the contribution of fibronectin to the spreading activity of the natural matrix produced by keratinocytes could not be determined using antifibronectin. Fibronectin mediated spreading at both high (1.1 mM) and low (0.1 mM) Ca++ concentrations, and spreading was not altered by cycloheximide. Insoluble fibronectin deposited by keratinocytes correlated with phagokinetic tracks on particulate gold salts, and added fibronectin, as well as type I collagen and type IV collagen, enhanced motility of keratinocytes. These studies show that production of fibronectin and responsiveness to it are similar in fibroblasts and keratinocytes and demonstrate that fibronectin can act as a matrix factor for keratinocytes.
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3894536
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Serum levels of TA-4, a tumor associated antigen of cervical squamous cell carcinoma, were measured in various gynecologic tumors with a RIA kit (DAINABOT). Immunohistochemical localization of TA-4 was also evaluated in the squamous cell carcinoma of the cervix. Serum TA-4 levels were elevated in 8.3% of patients with CIS, in 25% with stage Ia, in 56% with stage Ib, in 83% with stage II, in 75% with stage III and IV and in 100% with recurrent squamous cell carcinoma of the cervix, respectively. No patients were positive for TA-4 in endometrial and ovarian cancers. Serum TA-4 levels declined distinctively after treatment in accordance with the disappearance of initial tumors in some patients with advanced carcinoma. TA-4 was demonstrated immunohistochemically in 2 out of 8 CIS, 3 out of 8 microinvasive carcinoma, 4 out of 4 keratinizing type, 7 out of 7 large cell type and 3 out of 6 small cell type of invasive squamous cell carcinoma, respectively. In each type of carcinoma, TA-4 was positive in the differentiated cells. Similarly, it was found in the differentiated layers of normal squamous epithelium excluding the immature cells of the basal layer.
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3894535
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Immunohistochemical staining was performed for carcinoembryonic antigen (CEA) in tissues taken from 41 cases of cervical and 67 cases of endometrial adenocarcinomas. Utilizing this method, smear specimens from 21 cases with cervical and 25 cases with endometrial adenocarcinomas were investigated at the cell level.
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3894537
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Incidence and characterization of antibodies to zona pellucida (Z.P.) in human sera were studied and the following results were obtained. Some human sera showed positive immunofluorescent staining of porcine Z.P. after absorption with porcine red blood cells, liver and kidney. The incidence of immunofluorescence positive sera in infertile women was not significantly different from pregnant women and healthy men after absorption with porcine red blood cells, liver and kidney. Among sixteen sera with positive staining of porcine Z.P. after absorption, only two showed positive staining of human oocytes. The gammaglobulin fraction from the above two sera also stained human Z.P. but neither precipitated on the surface of Z.P. nor blocked human spermatozoa to penetrate into Z.P. of human oocytes. There was no correlation between the incidences of antibody to porcine Z.P. and of sperm immobilizing antibody in human sera. Some human sera blocked monoclonal antibodies to porcine Z.P. with different specificities to bind the solubilized porcine Z.P. antigens in an enzyme linked immunosorbent assay. The incidences of the positive sera were not significantly different among the groups of infertile women, pregnant women and healthy men. These results clearly indicate that anti Z.P. antibodies detected by the immunofluorescent staining of porcine Z.P. had no correlation with infertility. The presence of such antibodies, even in the sera of men, suggests that they might be the antibodies produced to some foreign antigens cross-reactive to porcine Z. P. but not autoantibodies produced to human Z.P.
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3894538
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Circulating antibody levels to the phenolic glycolipid from Mycobacterium leprae and soluble M. leprae antigens were monitored before, during and following ENL episodes in 12 patients. It was observed that during ENL reaction, there was a fall in circulating antibody levels to the phenolic glycolipid but not to the soluble antigens from M. leprae. When the patients had recovered from their ENL reactions, the anti-glycolipid antibody levels usually increased again to levels similar to those observed before the ENL reaction.
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3894539
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Phagocytic and bactericidal activities were studied in Mycobacterium leprae-infected normal (NI) and thymectomized/irradiated (TRI) mice at different time periods. No significant differences were seen in the phagocytic activity for Staphylococcus aureus at 3, 6, and 9 months in the normal infected (NI) and normal control (NC) mice. A slight but significant decrease in the phagocytosis of S. aureus was seen in the TRI as compared to the NI group at 3 months which recovered at 6 months. Phagocytosis of sheep erythrocytes was depressed in the TRI as compared to the NI group at 6 months only. No significant differences in the phagocytosis of latex particles were seen in any of the groups at any time of infection. Bactericidal activity was significantly reduced in the NI group as compared to the NC group and, similarly, in the TRI group as compared to the TRC group at all periods of infection. The M. leprae-infected T/R 900 group (TRI) showed more decrease in bactericidal activity when compared to the normal infected (NI) group.
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3894540
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The structures of multiplication by transverse fission found in the lepromas and livers of nude mice and nine-banded armadillos inoculated with Mycobacterium leprae isolated from human lepromas, a nine-banded armadillo with naturally acquired leprosy-like disease, and a nine-banded armadillo inoculated with M. leprae isolated from the mangabey monkey with naturally acquired leprosy infection are described. The images of multiplication by transverse fission of M. leprae were almost always found inside the phagolysosomes of lepra cells. At the time of multiplication by transverse fission, band structures were observed generally at both sides of the fission line. According to these results, multiplication of M. leprae by transverse fission is done inside the phagolysosomes of lepra cells of nude mice and nine-banded armadillos.
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3894551
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Transdermal scopolamine medication has been evaluated in 30 cases of acute peripheral vertigo. The double blind study revealed favourable effects, e.g. in Menière's disease. The best compromise between effect and side-effects was one active medication patch. The side-effects were those described for scopolamine, such as blurred vision and dryness of the mouth. Transdermal scopolamine seems to offer an alternative form of medication in acute peripheral vertigo.
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3894553
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In a multicentre, retrospective observational study on carcinomas of the oral cavity, including the lips and oropharynx, data material of 1021 patients has been analysed. The specific goals of this study were: Review of existing proposals for classification. Analysis of prognostically relevant factors of the tumour disease. Construction of a prognostic index for the determination of individual and collective prognoses. The following results were achieved: ad 1: All existing TNM-Classifications of oral cavity carcinomas so far fail to meet the requirements of the necessary criteria. ad 2: The multivariate analyses of prognostically relevant factors were performed with and without taking therapeutic factors into account. The results show unequivocally that reliable prognoses are only possible if various treatment modalities are considered. ad 3: This led to the construction of the treatment-dependent prognostic index TPI, which will be eligible for use in clinical-therapeutic cancer research and in clinical practice.
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3894557
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The effect of restricting placental growth on maternal glucose, insulin and placental lactogen was investigated in 16 ewes carrying singleton lambs. Uterine caruncles were removed from seven ewes (caruncle ewes) before pregnancy, resulting in reduced placental size and retarded intra-uterine fetal growth. The concentration of insulin in maternal plasma was similar in both control and caruncle ewes. The concentration of glucose was significantly higher in the caruncle than in the control ewes (3.26 +/- 0.15 (S.E.M.) mmol/l, number of observations (n) = 9, vs 2.75 +/- 0.1, n = 9, P less than 0.02, and 3.27 +/- 0.16, n = 7, vs 2.46 +/- 0.11, n = 12, P less than 0.001, for the carotid artery and utero-ovarian vein respectively). The concentration of ovine placental lactogen (oPL) in the utero-ovarian vein was reduced in the caruncle compared with the control ewes (283 +/- 65 micrograms/l, n = 8, and 705 +/- 106 micrograms/l, n = 18, P less than 0.02, respectively). Restriction of placental growth by removal of endometrial caruncles similarly reduced the concentrations of oPL in maternal arterial plasma (231 +/- 54 micrograms/l, n = 9, and 621 +/- 96 micrograms/l, n = 18, P less than 0.002). Production of oPL by the placenta was also reduced by limiting placental growth to 30 +/- 11 micrograms/min, n = 8, compared with 133 +/- 43 micrograms/min, n = 15, P less than 0.05, for the controls. Production of oPL per gram of placenta in the caruncle group, although only 34% of the control value, was not reduced significantly.(ABSTRACT TRUNCATED AT 250 WORDS)
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3894558
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Lipogenesis was determined at two times (07.00 and 16.00 h) during a 14-h daily photoperiod (08.00-22.00 h) in freshly prepared hamster hepatocytes with or without addition of insulin. The hamsters were pretreated for 5 days with bromocriptine (to inhibit prolactin secretion), bromocriptine and prolactin replacement, or control saline injections. Lipogenesis was determined by incorporation of [14C]acetate into total cell lipids over a 30-min interval. Lipogenesis was three times greater at 07.00 than at 16.00 h and insulin was effective in stimulating further lipogenesis only at 07.00 h. Bromocriptine pretreatment severely reduced incorporation of radiolabel at 07.00 h to levels comparable with controls at 16.00 h and completely inhibited the stimulatory effect of insulin at 07.00 h. Prolactin replacement in bromocriptine-treated hamsters reversed the inhibitory effect of bromocriptine on hepatocyte lipogenesis and promoted dramatic lipogenic responses to insulin at 07.00 h. These results indicate that insulin stimulates hepatic lipogenesis only during some portion of a day and that prolactin facilitates the lipogenic response.
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3894559
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We have investigated the possibility that microfilaments are involved in the priming effect of LH-releasing hormone (LHRH) by ultrastructural morphometry of hemipituitary glands from adult female mice. Glands incubated for 2 consecutive hours with 8.5 nmol LHRH/l responded with a marked increase in the amount of LH released into the medium during the second hour compared with the first hour of incubation. This priming effect of LHRH on LH secretion was accompanied by a significant margination of secretory granules and a drop in the total granule content of the gonadotrophs. Although the number of microfilaments remained the same, there was an increase in their length and a change in orientation so that the angle between the microfilaments and the plasmalemma was significantly reduced after both the first and second hour of exposure of LHRH. The addition of 14.3 mumol cytochalasin B/1 to the incubation medium significantly increased the amount of LH released in the first hour of incubation when compared with the amount of LH released by LHRH alone, but completely abolished the priming effect of LHRH. Cytochalasin B also prevented the LHRH-induced increase in the length and the change in orientation of the microfilaments. These results indicate that LHRH priming involves an increase in length of microfilaments and a change in their orientation relative to the plasmalemma.
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3894560
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Cortisol implants in normal and diabetic rats reduced body weight, adiposity, insulin receptor concentration and both basal and insulin-stimulated rates of lipogenesis in isolated adipocytes, whilst insulin sensitivity was unchanged. In normal but not diabetic rats these changes were accompanied by increased serum glucose and insulin concentrations. In contrast, progesterone implants in normal and diabetic rats increased body weight gain, adiposity, insulin receptor concentration and both basal and insulin-stimulated rates of lipogenesis in adipose tissue, again without affecting insulin sensitivity. Progesterone did not affect serum insulin concentrations in normal or diabetic rats but accelerated the decline in serum glucose concentrations which occurred during an overnight fast in diabetic rats. The results suggest that cortisol inhibits lipogenesis in adipose tissue without affecting insulin sensitivity, cortisol reduces insulin binding in adipose tissue without a requirement for hyperinsulinaemia, which might itself indirectly lead to down-regulation of the insulin receptor, and in diabetic rats progesterone stimulates lipogenesis in adipose tissue without any increase in food intake or serum insulin concentrations suggesting that progesterone may have a direct anabolic role in adipose tissue.
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3894561
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Early theorists (Skinner, Spence) interpreted discrimination learning in terms of the strengthening of the response to one stimulus and its weakening to the other. But this analysis does not account for the increasing independence of the two performances as training continues or for increases in control by dimensions of a stimulus other than the one used in training. Correlation of stimuli with different densities of reinforcement produces an increase in the behavior necessary to observe them, and greater observing of and attending to the relevant stimuli may account for the increase in control by these stimuli. The observing analysis also encompasses errorless training, and the selective nature of observing explains the feature-positive effect and the relatively shallow gradients of generalization generated by negative discriminative stimuli. The effectiveness of the observing analysis in handling these special cases adds to the converging lines of evidence supporting its integrative power and thus its validity.
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3894563
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Treatment of BALB/c mice with purified pig antiidiotype to 11-4.1 (anti-H-2Kk) monoclonal antibody has been found previously to induce the appearance of idiotype-bearing molecules (Id') in the serum of these mice, in the absence of detectable antigen-binding activity. In the present study we examined the effect of subsequent immunization of such antiidiotype-primed mice with the original H-2Kk antigen. Skin grafting of virgin BALB/c mice with BALB.K skin did not generate any detectable Id' antibodies when tested by enzyme-linked immunosorbent assay (ELISA). In contrast, grafting of antiidiotype-primed mice with BALB.K skin specifically boosted ther serum level of Id' molecules. Challenge of antiidiotype-primed mice with either B10.D2 or rat skin had no effect on the production of such Id' molecules. Absorption studies demonstrated that the majority of Id' molecules induced by H-2Kk antigenic stimulus and detected in ELISA are antigen-nonbinding molecules, thus indicating specific restimulation by the original H-2Kk antigen of nonbinding idiotype-positive B cell clones. The relevance of these findings to the existence of network interactions in the immune response to H-2 antigens is discussed.
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3894562
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We have determined the DNA sequence of a gene encoding a thymus leukemia (TL) antigen in the BALB/c mouse, and have more definitively mapped the cloned BALB/c Tla-region class I gene clusters. Analysis of the sequence shows that the Tla gene is less closely related to the H-2 genes than H-2 genes are to one another or to a Qa-2,3-region genes. The Tla gene, 17.3A, contains an apparent gene conversion. Comparison of the BALB/c Tla genes with those from C57BL shows that BALB/c has more Tla-region class I genes, and that one of the genes absent in C57BL is gene 17.3A.
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3894565
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Changes in amino acid concentrations in plasma during a 100 g oral glucose tolerance test were investigated in patients with liver cirrhosis and in healthy controls. In the controls, almost all amino acid concentrations reached a nadir about 3 hours after glucose loading, then returned to initial levels after 6 hours. Immunoreactive insulin levels reached a peak about 30 minutes after loading, then decreased gradually, reaching initial levels after 6 hours. In the controls, the decrease ratios, defined as maximum decrease during the 3 hours after loading/initial concentration in plasma, were 0.607 and 0.554 for isoleucine (Ile) and leucine (Leu) respectively and 0.382 for valine (Val) which is significantly lower than for Ile or Leu. A similar tendency was recognized in patients with liver cirrhosis. The initial concentration of tyrosine (Tyr) and phenylalanine (Phe) in liver cirrhosis was significantly higher and their decrease ratios were significantly lower than in controls. Though no difference was observed between initial concentrations of tryptophan (Trp) in controls and liver cirrhosis patients, the decrease ratio of Trp in liver cirrhosis was lower (0.061) than that of controls (0.279) (p less than 0.001). The value, t-Trp/BCAA + AAA, i.e. total Trp concentration (mmol/l)/concentration (mmol/l) of branched chain amino acids (BCAA, Ile + Leu + Val) plus aromatic amino acids (AAA, Tyr + Phe), which is known to correlate with the brain Trp concentration of rats (Fernstrom, J. D. & Wurtman, R. J. (1972) Science 178, 414-416), changed significantly from 9.6 +/- 2.4 (mean +/- 1 SD) at the initiation to 12.9 +/- 3.3 at 3 hours after loading in controls (p less than 0.001), and in liver cirrhosis it changed from 10.3 +/- 1.9 to 15.8 +/- 3.1 (p less than 0.001).
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3894564
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Immunoelectron microscopy with protein A gold has been used to determine the subcellular location of the ring-infected erythrocyte surface antigen (RESA) of Plasmodium falciparum. RESA was associated with dense vesicles presumed to be micronemes within merozoites. RESA was not detected on the surface of merozoites but was located at the membrane of erythrocytes infected with ring-stage parasites. RESA within merozoites was largely soluble in the nonionic detergent Triton X-100, but was insoluble in this detergent when associated with the erythrocyte membrane.
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3894566
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The physician, skilled in facilitating communication, can help the family of a terminally ill patient cope with stress. Lowering stress levels can reduce the risk of permanent psychological and physical damage to surviving members. This article illustrates appropriate interview techniques in five common stress areas: (1) social unacceptability of presenting symptoms and of death itself; (2) helplessness, anger, and guilt; (3) sexual feelings and expectations; (4) specific preparation for death; and (5) bereavement and grief after death. The physician's investment of modest amounts of time in direct care and in building ancillary resources can result in a significant service to grieving families.
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3894569
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Extracellular polymeric material (EP) was isolated from culture supernatants of Candida albicans grown on carbon sources (50 mM-glucose, 500 mM-sucrose or 500 mM-galactose) known to promote yeast adhesion to different extents. Galactose-grown yeasts, which are the most adherent, produced more EP than sucrose-grown organisms, particularly after incubation for 5 d, while glucose-grown yeasts (the least adherent) gave the lowest yield. EP produced on all three carbon sources was of similar composition and contained carbohydrate (65 to 82%; mannose with some glucose), protein (7%), phosphorus (0.5%) and glucosamine (1.5%). Serological studies indicated that these EP preparations were immunologically identical but that galactose-grown yeasts had more antigenic determinants than sucrose-grown organisms while glucose-grown yeasts had the fewest determinants. Antigenic differences were apparent between EP preparations of some strains of C. albicans. Pretreatment of acrylic strips with EP to form a polymeric coating promoted yeast adhesion to the acrylic surface, but similar pretreatment of buccal epithelial cells with EP inhibited subsequent yeast adhesion. These results indicate that EP originates from the cell surface of C. albicans and that it contains the surface component(s), probably mannoprotein in nature, responsible for yeast adhesion.
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3894570
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Candida albicans undergoes yeast to mycelial conversion under both in vivo and in vitro conditions but the relative pathogenicity of the two forms of growth is still unknown. By adapting a recently developed 51Cr radiolabel release assay, we have quantified the killing ability of different murine effector cell populations for the hyphal form of C. albicans. Up to 50% of specific 51Cr release from the mycelial form could be detected after incubation for only 1 h, with no requirement for opsonization, provided that appropriate effector: target cell ratios were used. The specific 51Cr release correlated well with viability, as assessed by dye exclusion tests, and with pathogenicity potential in cyclophosphamide-immunodepressed mice. Comparison of the activity of different murine effectors against yeast and hyphal forms showed that hyphal forms were killed by murine effectors to a similar, if not greater, extent than yeast forms. In particular, thioglycollate-induced murine polymorphonuclear neutrophils were able to kill hyphal cells extracellularly and without an opsonic requirement.
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3894571
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Mercury volatilization (Hg2+ reductase) activity has been found with Hg2+-resistant isolates of three Streptomyces species and with three Hg2+-resistant strains of group B Streptococcus from clinical sources in Japan. Hg2+ reductase activities in crude cell extracts showed the temperature sensitivity, the requirement for an added thiol compound and the characteristic dependence on NAD(P)H cofactors of similar enzymes isolated from other bacteria.
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3894572
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Phospholipase A and lysophospholipase activities were measured in the culture fluid and in the blastospores of Candida albicans. When phospholipase activity was measured in six yeasts (four strains of C. albicans and a single strain each of Candida parapsilosis and Saccharomyces cerevisiae) a correlation was found between this activity and two potential parameters of pathogenicity. The C. albicans isolates which adhered most strongly to buccal epithelial cells and were most pathogenic in mice had the highest phospholipase activities. Non-pathogenic yeasts, including C. albicans isolates which did not adhere and did not kill mice, had lower phospholipase activities.
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3894573
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We have examined the effects of wall populations on coexistence between strains of Escherichia coli in the liquid phase of mixed (two-strain) chemostats. The wall populations of the two competing strains became established soon after the start of the cultures and, although the relative abundance of the strains in the liquid phase could change over time by several orders of magnitude, the composition of an established wall population did not change markedly. The bacterial strains examined could not displace an established wall population of a competing strain. The presence of a permanent wall population allowed a strain that was less fit in the liquid phase to coexist with a superior strain. The resulting coexistence did not require that the inferior strain attached to the vessel wall better than the superior strain. We believe that the coexistence developed because the inferior strain survived and reproduced on the vessel wall. The progeny from that wall population then provided replacements for the bacteria that the inferior strain lost through a selective disadvantage in the liquid phase of the culture. By replacing the chemostat vessel, hence eliminating the wall populations, we could distinguish between cases where the coexistence depended on the presence of a wall population and where it resulted from some alternative mechanism.
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