ISSN:1660-8151    

DOI:10.1159/000187881

出版商:S. Karger AG    

年代:1994

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000187882

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Blood urea concentration is artificially low immediately following high-efficiency dialysis of duration T and will rise (‘rebound’) due to the continued diffusion of urea from the intracellular to the extracellular space. This leads to an overestimate of the efficiency of the dialysis given by KT/V (where V is the total distribution volume of urea and K is the urea clearance of the dialyser) if the true equilibrium blood concentration of urea is not used in the calculation of KT/V by the single-pool urea kinetic model (UKM). The measurement of the equilibrium urea concentration entails an additional blood sample 60 min after dialysis, but an estimate may be calculated using a blood sample taken 80 min following the start of dialysis together with an approximate formula derived from the 2-pool model. In 14 patients, an average error in the calculation of KT/V of 35% (range 19-75%) by the single-pool UKM was reduced to 13% (range 1-55%, but 8 measurements to < 7%) using the approximate technique. It is concluded that the approximate technique significantly improves the accuracy of dose estimation in high-efficiency dialysis without inconveniencing the pati

ISSN:1660-8151    

DOI:10.1159/000187883

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Prior to beginning to administration erythropoietin (EPO) in 1989, we examined the relationships of hematocrit (HCT), mean corpuscular volume (MCV), and serum ferritin (FER) in one group of hemodialysis patients (group A, n = 117) and replicated the findings in a second group (group B, n = 73). The groups had similar mean ( ± SD) HCT (A: 25.7 ± 5.3%; B: 25.2 ± 5.1%), MCV (A: 83.3 ± 6.5 fl; B: 83.5 ± 7.5 fl) and FER (A: 607 ± 1446 µg/l; B: 374 + 601 µg/l). For group A, iron stores [log (FER)] correlated inversely with HCT (r = -0.44, p < 10-4) and directly with MCV (r = 0.32, p < 10-3). After dividing group A into octiles by the FER level, the lowest octile (mean FER 17.8 ± 6.2 µg/l) had the highest mean HCT (29.5 ± 6.4%) and lowest mean MCV (80.8 ± 7.1 fl), while the highest octile (mean FER 3,312 ± 3,005 µg/l) had the lowest mean HCT (21.9 ± 2.8%) and the second-highest mean MCV (86.4 ± 4.9 fl). The trends were similar in group B. We conclude that increased erythropoiesis appeared to cause or, at least, unmask iron deficiency in HD patients even prior to the advent of EPO therapy. Variations in the level of erythropoiesis among these patients (presumably due to variation in EPO levels, chronic inflammation) strongly influenced the determinants of iron stores (i.e., marrow utilization of iron, transfusion need); iron stores, in turn,

ISSN:1660-8151    

DOI:10.1159/000187884

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Slow hemodialysis (HD) was performed for 10 h during the day in 11 critically ill patients with renal failure. The dialysis method was a modification of the pump-driven continuous venovenous HD. A nonsterile bicarbonate-containing hemodialysate was passed into the EVAL membrane dialyzer at a flow rate of 30 ml/min. No patient developed further hemodynamic instability during the treatment. The serum urea level was maintained below 20 mmol/l within 4 days of initiating the treatment. It allowed the patients to rest without interruption at night. This method was safely conducted by general nursing staff under the supervision of nephrologists on duty during the day. This schedule offers an approach to renal replacement therapy for hemodynamically unstable patients without any potential problem in the extracorporeal circulation at night.

ISSN:1660-8151    

DOI:10.1159/000187885

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Lipid peroxidation products, both lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS) were determined in the plasma of 31 uremic patients treated with maintenance hemodialysis. Whereas patients had significantly elevated TBARS compared to 93 healthy controls (4.25 ± 1.53 vs. 1.66 ± 0.50 μmol/l; p 0.01). However, when the TBARS were corrected for hemoconcentration by relating TBARS to the plasma cholesterol concentrations a statistically significant decrease of TBARS was observed (1.02 ± 0.63 μmol TBARS/mmol cholesterol vs. 0.84 ± 0.60 μmol TBARS/mmol cholesterol; p < 0.01) after 240 min of hemodialysis. There was no evidence for the formation of plasma lipid hydroperoxides in the extracorporeal circulation. It is therefore suggested that elevated TBARS in chronic renal failure are not caused by the dialysis

ISSN:1660-8151    

DOI:10.1159/000187886

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Intermittent bolus administration of calcitriol – i.e., 1,25-dihydroxycholecalcife-rol or 1,25-(OH)2D3 20 pmol/l, normal 1-6 pmol/l) levels were randomly allocated to daily administration of 0.75 μg calcitriol (continuous) or twice weekly administration (intermittent); the two protocols provided an identical total weekly doses of 5.25 μg calcitriol. Patients were dialyzed with a dialysate Ca concentration of 1.75 mmol/l and had oral CaCO3 or Ca acetate. 1,84-iPTH (immunoradiometric assay) and serum Ca and Pi levels were measured weekly. At the beginning of the study, the median 1,84-iPTH value was 37 pmol/l (range 20-115) in the intermittent versus 36 pmol/l (range 21-72) in the continuous calcitriol group. After 2 weeks, the median 1,84-iPTH level was 18.5 pmol/l (range 1.4-106) versus 18 pmol/l (range 1.2-48). After 12 weeks, 11 of 21 of the patients in the intermittent and 18 of 24 patients in the continuous group had reached the treatment goal, i.e., 1,84-iPTH 2.2 mm

ISSN:1660-8151    

DOI:10.1159/000187887

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Chronic phosphate depletion (PD) causes a rise in basal level of cytosolic calcium ([Ca2+]i) in rat brain synaptosomes, a decrease in their ATP content and a reduction in Vmax of their Ca2+ ATPase and Na+-K+ ATPase. The chronology of the events that lead to these derangements is not elucidated. The present study examined this issue by evaluating the changes in rat in these parameters in brain synaptosomes during the evolution of PD over a period of 6 weeks. The results show that the initial derangement is a rise in the Vmax of Ca2+ ATPase during the first 2 weeks of PD. This is followed by a rise in [Ca2+]i, a fall in ATP content and decrease in the Vmax of Ca2+ ATPase and Na+-K+ ATPase by the end of the 3 week and most of these derangement worsened during the 4th to 6th weeks of PD. Taken together our data are consistent with the notion that PD is associated with an initial increase in calcium influx into the synaptosomes. This is followed by a modest but significant rise in [Ca2+]i which in turn would inhibit mitochondrial oxidation and ATP generation leading to a decrease in ATP content. The latter compromises the activity of Ca2+ ATPase and Na+-K+ ATPase which are involved, directly or indirectly, in calcium extrusion out of the synaptosomes. The increased entry of calcium combined with decreased calcium extrusion are followed by a further rise in basal levels of [Ca2+]i. This sequence of events continues until a steady state is reached and is characterized by reduced basal ATP content, reduced Vmax of Ca2+ ATPase and Na+-K+ ATPase and elevated basal level of [Ca2+]i.

ISSN:1660-8151    

DOI:10.1159/000187888

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The treatment of membranoproliferative glomerulonephritis (MPGN) is considered by most authors as unrewarding, and the disease progresses to end-stage renal disease (ESRD). We studied the effectiveness of a new immunosuppressive (IS) regimen by analyzing the rates of remission, relapse and progression to ESRD in 19 patients with MPGN. The treatment consisted of 4 phases: (1) induction with intravenous boluses of methylprednisolone plus cyclophosphamide (CPM) orally; (2) maintenance with oral prednisone (PDN) in an alternateday regimen and CPM in a daily oral dose; (3) tapering during which PDN alone was slowly decreased; (4) discontinuation when CPM was omitted and PDN slowly withdrawn according to the steroid withdrawal schedule. At the end of the treatment that lasted on average 10 ± 1 months, 15 patients remitted, 3 improved and 1 progressed. There were 8 relapses in 6 patients: 4 in 3 patients were treated with repeat cycles and remitted completely. Four patients who had relapsed after 4, 8,11 and 13 years of remission refused retreatment and progressed rapidly to ESRD. All patients treated and retreated after relapsing had remissions, while renal failure and disease progression occurred in 1 patient only. Plasma creatinine averaged, in the whole group, 165 ± 26 before, 156 ± 30 after treatment and 224 ± 57 μM/1 at the end of 7.4 ± 0.8 years of follow-up. An intensive IS regimen combining steroids and alkylating agents in high doses and for a prolonged time is effective in inducing remission and halting progression to ESRD in patients with

ISSN:1660-8151    

DOI:10.1159/000187889

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Cyclosporine (CsA) nephrotoxicity is partially mediated by renal vasoconstriction due to an imbalance between vasodilator and vasoconstrictor eicosanoids. LSL 90202 is a purified lysine salt of eicosapentaenoic acid which is a known inhibitor of renal eicosanoid synthesis. The aim of the present work was to determine if chronic dietary supplementation with LSL 90202 prevented CsA nephrotoxicity and to establish the role of thromboxane and prostacyclin in renal tissue. Thirty-three male Sprague-Dawley rats were divided into 4 groups: group 1, CsA in olive oil (n = 10); group 2, isovolumetric olive oil (n = 7); group 3, CsA in olive oil plus LSL 90202 (n = 8); group 4, isovolumetric olive oil plus LSL 90202 (n = 8). CsA and LSL 90202 were given at 20 mg/kg/day. Weight and creatinine clearance (CrCl) were determined before and on days 14 and 30. On day 30 whole-blood CsA was determined and renal tissue processed for renal malondialdehyde, thromboxane B2 and 6-keto-PGF1α measurement and for conventional histology. CrCl was severely reduced in the CsA in olive oil group compared to olive oil and LSL 90202 control groups. On day 30, CrCl in the CsA in olive oil plus LSL 90202 group showed a slight decrease, but the mean CrCl was significantly higher than in the CsA in olive oil group. Trough whole blood CsA levels were not significantly different in both groups given the drug. No morphological differences were found between groups. Renal content of thromboxane B2 and 6-keto-PGF1α (the stable metabolites of thromboxane A2 and prostacyclin, respectively) was higher in CsA in olive oil group than in olive oil control group. In contrast, both eicosanoids were similarly low in both groups receiving LSL 90202. The difference between group 1 and group 3 was statistically significant. In summary, our results suggest that LSL 90202 modifies CsA nephrotoxicity and that its benefitial effect may be due to its influence on intrarenal biosynthesis of thomboxane A2 and prostacycli

ISSN:1660-8151    

DOI:10.1159/000187890

出版商:S. Karger AG    

年代:1994

数据来源: Karger