***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Anemia is one of the most serious complications in patients on dialysis .  Erythropoietin improves the anemia . However , erythropoietin resistance is sometimes encountered from causes such as functional iron deficiency , secondary hyperparathyroidism , blood loss , or interaction with other drugs . To clarify the interaction between erythropoietin and the renin-angiotensin system , we studied the maintenance dose of recombinant human erythropoietin ( rHuEPO ) in patients on continuous ambulatory peritoneal dialysis ( CAPD ) with and without angiotensin converting enzyme inhibitor ( ACEIs ) , angiotensin II type I receptor blockers ( ARBs ) , and calcium channel blockers . We divided 36 hypertensive patients on CAPD into three groups -- an ACEI group ( n = 12 ) , an ARB group ( n = 12 ) , and a Ca channel blocker group ( n = 12)-- and then we compared the doses of rHuEPO required to maintain the patients ' hematocrit ( Hct ) above 30 % . In the Ca channel blocker group , the weekly dose of erythropoietin had not changed significantly at the end of the study ( 74 + /- 7 U/kg at the end vs. 76 + /- 8 U/kg at the start ) . The ( oral ) ACEI group needed a significantly higher weekly dose of erythropoietin at the end of the study ( 89 -/+ 9 U/kg at the end vs. 74 -/+ 8 U/kg at the start , p < 0.01 ) . The ( oral ) ARB group also needed a significantly higher weekly dose of erythropoietin at the end of the study ( 82 -/+ 10 U/kg at the end vs. 76 + /- 8 U/kg at the start , p < 0.05 ) . Furthermore , the weekly dose of erythropoietin required in the ACEI group was significantly larger than that required in the ARB group . We conclude that treatment with ACEIs and ARBs induces erythropoietin resistance in patients on CAPD . The inhibitory effect of ARBs on erythropoiesis is less than that of ACEIs In patients with renal anemia , iron therapy can be administered intermittently or regularly at a low dose . We performed a r and omized clinical trial in pediatric patients with end-stage renal failure on hemodialysis and absolute or functional iron deficiency . The study group received maintenance iron therapy according to the ferritin serum levels and the control group received intermittent 10-weekly doses . Success was defined as stabilization of ferritin levels between 100 and 800 μg/l and transferrin saturation ( TSAT ) between 20 % and 50 % , in addition to an increase in the hemoglobin level . The major reason for exclusion was iron overload . The study group received 6 mg/kg per month of parenteral iron [ 95 % confidence interval ( CI ) 3.3–8.8 ] and the control group 14.4 mg/kg per month ( 95 % CI 12–16.8 ) ( P<0.001 ) . After 4 months of treatment , ferritin levels increased to 66 μg/l ( 95 % CI 69–200 ) in the study group and to 334 μg/l ( 95 % CI 145–522 ) in the control group ( P=0.009 ) . Maintenance therapy and intermittent weekly doses were successful in 73 % and 38 % , respectively . After 3 months of treatment , hemoglobin levels increased to 10 g/dl , with no difference between the groups . However , in the control group the increase in hemoglobin levels was unsustained , and 3 patients needed transfusion . Patients in the control group had a higher risk of iron overload than patients in the study group ( 70 % vs. 19 % ) . Thus , the regimen based on assessment of serum ferritin levels was more efficient than the intermittent regimen because it increased and maintained the hemoglobin levels with lower iron doses and a lower risk of iron overload In a prospect i ve study , 40 maintenance hemodialysis patients , r and omized in two equal groups , were treated with recombinant human erythropoietin ( rHuEPO ) for their renal anemia , for a period of 2 years . One group was treated for 2 years , while the other was untreated control during the first year , but received rHuEPO during the second year of the study . Anemia was corrected in all treated patients and hematocrit maintained between 30 and 35 vol% by low-dose subcutaneous treatment with Recormon ( Boehringer Mannheim GmbH , Germany ) , according to the study protocol . Bone marrow biopsy ( BMB ) , from the posterior iliac crest , was taken by the method of Jamshidi from 32 patients . Fourteen patients from the control group were biopsied twice : once at baseline and the second time at 12 months of treatment , while 15 patients from the other group were biopsied only once , at 24 months of rHuEPO treatment . The biopsies were embedded in wax and in epoxy resin , and after staining for light and electron microscopy , they were semiquantitatively examined for several parameters : cellularity , myeloid : erythroid ( M : E ) ratio , megakaryocytes , fatty tissue , megaloblasts , and marrow iron . Cellularity of the bone marrow increased significantly at 12 months of treatment and it remained so at 24 months . M : E ratio was significantly reduced indicating expansion of the erythroid pool , both at 12 and 24 months of therapy . The number of megakaryocytes in the bone marrow increased significantly at 12 months and remained high at 24 months of treatment , while fatty tissue was significantly reduced at 12 and 24 months compared to the baseline values . There was no significant change in the percentage of megaloblasts in the bone marrow . Hemosiderin was reduced after treatment indicating mobilization of the bone marrow iron stores upon treatment with rHuEPO . We concluded that rHuEPO had a beneficial long-term effect on bone marrow Small-solute clearance targets for peritoneal dialysis ( PD ) have been based on the tacit assumption that peritoneal and renal clearances are equivalent and therefore additive . Although several studies have established that patient survival is directly correlated with renal clearances , there have been no r and omized , controlled , interventional trials examining the effects of increases in peritoneal small-solute clearances on patient survival . A prospect i ve , r and omized , controlled , clinical trial was performed to study the effects of increased peritoneal small-solute clearances on clinical outcomes among patients with end-stage renal disease who were being treated with PD .  A total of 965 subjects were r and omly assigned to the intervention or control group ( in a 1:1 ratio ) . Subjects in the control group continued to receive their preexisting PD prescriptions , which consisted of four daily exchanges with 2 L of st and ard PD solution . The subjects in the intervention group were treated with a modified prescription , to achieve a peritoneal creatinine clearance ( pCrCl ) of 60 L/wk per 1.73 m(2 ) . The primary endpoint was death . The minimal follow-up period was 2 yr . The study groups were similar with respect to demographic characteristics , causes of renal disease , prevalence of coexisting conditions , residual renal function , peritoneal clearances before intervention , hematocrit values , and multiple indicators of nutritional status . In the control group , peritoneal creatinine clearance ( pCrCl ) and peritoneal urea clearance ( Kt/V ) values remained constant for the duration of the study . In the intervention group , pCrCl and peritoneal Kt/V values predictably increased and remained separated from the values for the control group for the entire duration of the study ( P < 0.01 ) . Patient survival was similar for the control and intervention groups in an intent-to-treat analysis , with a relative risk of death ( intervention/control ) of 1.00 [ 95 % confidence interval ( CI ) , 0.80 to 1.24 ] . Overall , the control group exhibited a 1-yr survival of 85.5 % ( CI , 82.2 to 88.7 % ) and a 2-yr survival of 68.3 % ( CI , 64.2 to 72.9 % ) . Similarly , the intervention group exhibited a 1-yr survival of 83.9 % ( CI , 80.6 to 87.2 % ) and a 2-yr survival of 69.3 % ( CI , 65.1 to 73.6 % ) . An as-treated analysis revealed similar results ( overall relative risk = 0.93 ; CI , 0.71 to 1.22 ; P = 0.6121 ) . Mortality rates for the two groups remained similar even after adjustment for factors known to be associated with survival for patients undergoing PD ( e.g. , age , diabetes mellitus , serum albumin levels , normalized protein equivalent of total nitrogen appearance , and anuria ) . This study provides evidence that increases in peritoneal small-solute clearances within the range studied have a neutral effect on patient survival , even when the groups are stratified according to a variety of factors ( age , diabetes mellitus , serum albumin levels , normalized protein equivalent of total nitrogen appearance , and anuria ) known to affect survival . No clear survival advantage was obtained with increases in peritoneal small-solute clearances within the range achieved in this study BACKGROUND Intravenous ascorbic acid ( IVAA ) administration is reported to enhance erythropoiesis in hemodialysis ( HD ) patients with functional iron deficiency . We explored the effects of IVAA on erythropoiesis and health-related quality of life ( HRQOL ) in unselected HD patients . METHODS Sixty-one HD patients were divided into two groups ; 30 patients received 100 mg of IVAA ( IVAA group ) and 31 patients did not ( control group ) after each dialysis session . Hematocrit ( Hct ) , reticulocyte hemoglobin content , transferrin saturation , ferritin , weekly recombinant human erythropoietin ( rHuEPO ) dosage , weekly intravenous iron ( IVFE ) dosage , and MOS Short Form 36 ( SF-36 ) scale scores were measured at baseline and after 6 months of treatment . RESULTS Mean changes in Hct in the IVAA and control groups were -0.5 and -0.6 mg/dL , respectively , while mean changes in SF-36 scale scores were : physical functioning -1.6 in the IVAA group and 0.38 in the controls ; role physical ( RP ) 3.8 and 9.4 ; bodily pain 9.7 and 0.81 ; general health perception 3.7 and -0.68 ; vitality 4.3 and -7.5 ; social functioning 2.7 and 0.43 ; role emotional ( RE ) 6.9 and 4.9 ; mental health 3.6 and -1.7 . The IVAA group showed significantly higher adverse events ( chest pain : n=1 , nausea : n=2 and fatigue : n=2 ) compared to the controls ( no event ) . CONCLUSIONS The beneficial effects of IVAA on erythropoiesis and HRQOL were not demonstrated in unselected HD patients . Indication of IVAA for HD patients leaves room for further study One hundred and fifty patients undergoing regular haemodialysis for end-stage renal failure entered a trial of treatment for anaemia with recombinant human erythropoietin ( r-HuEPO ) . At data cut-off 37 patients ( 24.6 % ) had dropped out for various reasons ; most of them ( n = 22 ) discontinued because of kidney transplantation ( after 3 - 17 months of treatment ) . The initial dose was 24 U/kg i.v . thrice weekly , with subsequent dose escalations after a minimum of 2 weeks if the haemoglobin ( Hb ) was less than 10 % above the pretreatment baseline . One hundred and forty-three patients who were eligible for efficacy analysis achieved an Hb increase of greater than or equal to 2 g/dl , and all 139 patients eligible for ' full response ' analysis ( Hb between 10 and 12 g/dl ) were dose titrated to reach this arbitrarily defined optimal range . Patients ' response to r-HuEPO treatment was independent of age , weight , nephric state or duration of dialysis treatment . To maintain the Hb within the range of 10 - 12 g/dl during 1 year 's treatment ( n = 96 ) a median weekly r-HuEPO dose of 200 U/kg ( range 150 - 300 ) divided into one , two , or three administrations appeared to be adequate . This maintenance dose depends slightly on the patient 's baseline Hb . The study provides evidence that long-term treatment with r-HuEPO is safe . In 48 patients ( of whom 12 had no history of hypertension ) elevation of blood pressure required additional treatment , which was effective in all but one who was withdrawn from the study . Four patients had seizures and one suffered hypertensive encephalopathy without convulsions . ( ABSTRACT TRUNCATED AT 250 WORDS BACKGROUND The optimal haemoglobin concentration ( [ Hb ] ) for patients with end-stage renal failure is uncertain . In particular , it is unclear whether Hb normalization may be an advantage to such patients who are otherwise well . METHODS A prospect i ve , r and omized , double-blind cross-over study was completed in 14 haemodialysis patients ( 12 male ) aged between 23 and 65 years over a 
    Output:
    
Hb > or = 133 g/L was not associated with a reduction in the risk of all-cause mortality compared with 120 g/L in dialysis and pre-dialysis patients .
Lower Hb targets were significantly associated with an increased risk for seizures but a reduced risk of hypertension .