Evoked potentials in children with chronic renal failure,treated conservatively or by continuous ambulatory peritoneal dialysis

Children with chronic renal failure (CRF) show developmental, intellectual and motor disturbances. It is questionable if an early start of renal replacement therapy may prevent or delay these disturbances. We studied the neurological and intellectual development of children <5 years suffering from CRF (creatinine clearance <20% of normal) prospectively, over a period of 3 years. As part of the neurological study, brainstem auditory evoked potentials (BAEP) and somatosensory evoked potentials (SSEP) were recorded. Measurements were performed in a group of 22 children every 6 months. In 18 of these children CRF was present from birth. Sufficient data were available for analysis in 19 (BAEP) and 22 (SSEP), respectively. A delay of peak I of BAEP gave indications for peripheral conduction disturbances, possibly due to cochlear dysfunction. Brainstem conduction was normal. There were no differences between the children treated conservatively (n = 9) and those treated with continuous ambulatory peritoneal dialysis (CAPD) (n = 10). In children <2.5 years SSEP showed a delayed thalamocortical conduction, which was not observed in older children. This might indicate a delayed myelination in young children with CRF. No differences were found between the children treated conservatively (n = 10) and those treated with CAPD (n = 12).     

Deoxyribonuclease activity in T and B lymphocytes of haemodialysed patients with uraemia

Deoxyribonuclease (DNase) activity and metal ion concentrations in lymphocytes of patients with chronic renal failure and in healthy controls were studied. The data suggest that T and B lymphocyte nuclei of patients with renal failure show increased DNase activity when compared to their healthy counterparts. It is suggested that the enhancement of enzyme activity is a result of increased metal ion concentration rather than increased enzyme copy count. The data strongly suggest that haemodialysis of uraemic patients is more effective for improvement of lymphocyte metabolism than the conservative chemical treatment.     

Low protein diet causes a decrease in serum concentrations of leptin and tumour necrosis factor-alpha in patients with conservatively treated chronic renal failure

BACKGROUND: Chronic renal failure (CRF) provokes derangement in various hormonal regulations of food intake and energy expenditure. In the present study, we have examined the effect of a low protein, low phosphorus diet on circulating levels of leptin, tumour necrosis factor (TNF)-alpha, and insulin in patients with CRF. METHODS: Seventeen male, non-diabetic subjects with conservatively treated CRF (estimated creatinine clearance 39.5 +/- 11.1 mL/min), and proteinuria below 2 g/day were prospectively studied. Measurements of hormonal, metabolic and anthropometric parameters were performed before and after 16 weeks of dietary treatment (protein 0.6 g/kg of ideal body mass, 30% of calories derived from fat, 62% of calories derived from carbohydrates and 10 mg/kg of phosphorus). Actual dietary intake in patients was measured by using 3-day food records and was supervised by the dietician. RESULTS: Body mass index and body fat mass remained unchanged during the 4 months of dietary treatment. Urea, leptin, and TNF-alpha serum concentrations decreased significantly. CONCLUSIONS: A low protein, low phosphorus diet reduces TNF-alpha and leptin levels in plasma. The effect on leptin appears not to be mediated by an insulin-dependent mechanism.     

Platelet count and thrombopoietic activity in patients with chronic renal failure

The frequency of thrombocytopenia in patients with chronic renal failure (CRF) is controversial. This study was undertaken to investigate the platelet count in 55 patients with end-stage renal disease on maintenance hemodialysis and in 19 patients with CRF before hemodialysis had begun. In both groups platelet counts were similar and significantly reduced, 175,000 +/- 6,500 and 181,000 +/- 10,800 compared to 253,000 +/- 3,700/mm3 in the control (p less than 0.0001). 31% of hemodialysis patients had thrombocytopenia (platelet count less than 150,000/mm3). The megakaryocyte number in their bone marrow aspirate was not reduced. Primary renal disease, androgen treatment or parathyroidectomy did not affect the platelet count. Thrombopoietic activity using 75Se-selenomethionine incorporation into platelets measured in 7 thrombocytopenic patients was found to be reduced, 6.77 +/- 0.29 vs. 9.06 +/- 0.27 (X 10(-2)%: p less than 0.001). This study shows that the platelet count is reduced and mild thrombocytopenia is frequent in patients with CRF. A possible cause for the platelet count reduction is insufficient thrombopoietic activity.     

Myoinositol incorporation into lymphocytes of chronic renal failure patients is impaired

Incorporation of myo-[2-³H]-inosital into peripheral blood mononuclearcells (PBMNC) and T-cell enriched lymphocytes was evaluatedin in-vitro experiments in chronic renal failure (CRF) patientsand healthy subjects. Incorporation of myo-[2-³H]-inosital intothe cells of CRF patients on conservative and haemodialysistreatment was found to be impaired in comparison with that observedin normal cells. Following PHA stimulation of the cells of CRFpatients myo-[2-³H]-inosital incorporation decreased even further,while it increased in normal cells. Five hour haemodialysissession significantly depressed myoinositol incorporation intoPBMNC, while its incorporation into T-cell enriched lymphocytesremained unaffected. Myoinositol incorporation into PBMNC andT-cell enriched lymphocytes was inhibited by prostaglandinsand leukotrienes and was inversely related to the extent ofpertussis toxinsensitive G protein activation. Reduced myoinositolincorporation into uraemic PHA-stimulated PBMNC may depend atleast in part on their enhanced PGE₂ and LTB₄ release accompaniedby increased intracellular cAMP production. In CRF impairedmyoinositol incorporation into immune cells may prove the disarrangementin the early events of transmembrane signal transduction, whichmay share the responsibility for the cell-mediated immune defectin these patients.     

Zinc in patients with chronic renal failure

In order to assess zinc status in patients with chronic renal failure (CRF) plasma and erythrocyte zinc levels were determined in 13 patients undergoing regular haemodialysis. Additional determinations of plasma copper, plasma and erythrocyte magnesium and potassium were also performed. The mean plasma zinc level was slightly less than normal, but the difference was not statistically significant. The erythrocyte zinc content, however, as well as erythrocyte magnesium and potassium levels were significantly increased (p<0.001). This increase may be partly related to haemolysis in uraemia. Plasma copper concentration in CRF patients did not differ significantly from the control level. The almost normal plasma zinc concentration, elevated erythrocyte zinc, and normocupraemia do not indicate zinc deficiency in CRF patients.     

慢性肾功能衰竭患者的高同型半胱氨酸血症

目的 研究慢性肾功能衰竭（ＣＲＦ）患者血浆同型半胱氨酸（Ｈｃｙ）水平、影响因素以及与心、脑血管疾病的关系。方法 采用荧光偏振免疫分析法测定１６０例ＣＲＦ患者血浆总同型半胱氨酸（ｔＨｃｙ）水平，以３１例冠心病患者和４５例正常人为对照。结果 以正常组血浆ｔＨｃｙｘ±２ｓ为９５％可信度上限，ＣＲＦ患者高同型半胱氨酸血症的发生率为８２．５０％，明显高于冠心病组（２２．５８％）（Ｐ＜０．０１）；血液透析（ＨＤ）组血浆ｔＨｅｙ水平［（２４．１３±１２．６８）μｍｏｌ／Ｌ，ｎ＝７３］明显高于持续性非卧床腹膜透析（ＣＡＰＤ）组［（１６．４３ ±５．５８）μｍｏｌ／Ｌ，ｎ＝１９］、冠心病组［（１１．１３±４．９７）μｍｏｌ／Ｌ，ｎ＝３１］以及正常组（７．９７±２．６５）μｍｏｌ／Ｌ，ｎ＝４５，Ｐ均＜０．０１。９２例透析治疗的ＣＲＦ患者中有明确心、脑血管病者的血浆ｔＨｃｙ水平［（２７．１２±１５．９４）μｍｏｌ／Ｌ，ｎ＝３０］明显高于无此类病史的患者［（２０．１７±８．７１）μｍｏｌ／Ｌ，ｎ＝６２］。未经透析的 ＣＲＦ患者血浆 ｔＨｃｙ水平与内生肌酐清除率呈负相关（ｒ＝－０．３７４，Ｐ＜０．０１），与患者年龄、血葡萄糖、血脂及血浆白     

End-stage chronic renal failure in patients treated by antireflux operation]

We report 3 patients progressed to end-stage chronic renal failure after antireflux surgery. Preoperatively, the 3 patients had proteinuria, probably due to reflux nephropathy. Surgical procedures used were Paquin's method in 1 patient and Politano-Leadbetter's method in 2. Rapid deterioration of renal function was observed from puberty in all patients. In addition, renal hypoplasia was suspected in 2 patients. We concluded that both reflux nephropathy and renal hypoplasia played important roles in the progression of renal insufficiency.     

Major surgery in patients with chronic renal failure

To determine the risks of performing major surgical procedures on patients with chronic renal failure, the charts of twenty-nine hemodialysis patients who underwent thirty-eight elective and nine emergency operations were reviewed. Preoperative preparation included adequate hemodialysis of the patients, 88 per cent of whom were dialyzed within 24 hours of surgery. Azotemia was well controlled prior to administration of anesthesia. The average preoperative hematocrit was 26 per cent, and only one patient was hyperkalemic preoperatively. There were no intraoperative complications attributable to the patients' impaired renal function. Postoperative complications were frequent and are discussed in detail. Hemodialysis was done immediately postoperatively in five patients and on the first postoperative day in twenty-three additional patients with no problems. There were only two deaths (4.3 per cent) in the series. With careful monitoring during the perioperative period, major surgical procedures can safely be performed on patients with chronic renal failure.     

Adrenal function in patients with chronic renal failure

Previous studies have reported divergent findings on the function of the hypothalamic-pituitary-adrenal axis in patients with chronic renal failure (CRF). The low-dose adrenocorticotropin (ACTH) test offers the possibility of unmasking adrenal dysfunction, which might remain undiscovered using the ACTH test with the standard 250-microg dose. Furthermore, the choice of renal replacement therapy (either hemodialysis or continuous ambulatory peritoneal dialysis [CAPD]) might have an impact on adrenal function. To investigate these possibilities, ACTH tests were performed with three different doses (ie, 1, 5, and 250 microg) in 14 CRF patients and in seven healthy controls. Seven of the CRF patients were receiving chronic hemodialysis and seven were receiving CAPD. Basal plasma concentrations of cortisol were comparable in the three groups tested (5.3+/-0.4 microg/dL in the controls, 6.6+/-0.7 microg/dL in the hemodialysis patients, and 7.9+/-1.0 microg/dL in the CAPD patients), whereas basal ACTH concentrations were significantly elevated in the CRF patients (28.5+/-3.8 pg/mL in the hemodialysis patients and 33.0+/-6.0 pg/mL in the CAPD patients) when compared with normal controls (17.0+/-1.4 pg/mL; P < 0.05). All three doses of ACTH resulted in a rapid increase of plasma cortisol concentrations that was comparable in all three groups. In the hemodialysis patients, a trend toward a diminished response to the lowest dose of 1 microg was noticed. We conclude, therefore, that adrenal response to ACTH in various doses is unaffected in CRF independent of whether hemodialysis or CAPD is chosen for renal replacement therapy.     

Energy expenditure in patients with chronic renal failure

Although nondialyzed, chronically uremic patients and patients undergoing maintenance hemodialysis often show evidence for wasting and calorie malnutrition and have low dietary energy intakes, their energy expenditure has never been systematically evaluated. It is possible that low energy intakes are an adaptive response to reduced energy needs; alternatively, energy expenditure could be normal or high and the low energy intakes would be inappropriate. Energy expenditure was therefore measured by indirect calorimetry in 12 normal individuals, 10 nondialyzed patients with chronic renal failure, and 16 patients undergoing maintenance hemodialysis. Energy expenditure was measured in the resting state, during quiet sitting, during controlled exercise on an exercise bicycle, and for four hours after ingestion of a test meal. Resting energy expenditure (kcal/min/1.73 m2) in the normal subjects, chronically uremic patients and hemodialysis patients was, respectively, 0.94 +/- 0.24 (SD), 0.91 +/- 0.20, and 0.97 +/- 0.10. There was also no difference among the three groups in energy expenditure during sitting, exercise, or the postprandial state. Within each group, energy expenditure during resting and sitting was directly correlated. During bicycling, energy expenditure was directly correlated with work performed, and the regression equation for this relationship was similar in each of the three groups. These findings suggest that for a given physical activity, energy expenditure in nondialyzed, chronically uremic patients and maintenance hemodialysis patients is not different from normal. The low energy intakes of many of these patients may be inadequate for their needs.     

Hip arthroplasty in patients with chronic renal failure

Patients with chronic renal failure who underwent total hip arthroplasty were retrospectively evaluated. Thirty hips in patients with renal transplants and 16 hips in patients on chronic renal dialysis were reviewed. The average follow-up period was 54 months. The renal transplant patients exhibited generally satisfactory results. Their postoperative course was comparable to that of patients with avascular necrosis undergoing hip reconstruction without underlying renal disease. However, patients undergoing hip arthroplasty while on chronic renal dialysis had poor results (81%), including a deep infection rate of 19%. It was concluded that total hip arthroplasty be reserved for patients who are expecting a renal transplant or preferably for those who have already received a successful transplant.     

Calcitriol metabolism in patients with chronic renal failure

We studied calcitriol metabolism in white patients with chronic renal failure and in age- and sex-matched normal subjects. The plasma levels of calcitriol (21.9 +/- 1.6 pg/mL, n = 7, v control, 37.4 +/- 2.9 pg/mL, P less than 0.001), metabolic clearance rate (MCR) of calcitriol (0.45 +/- .01 mL/min/kg v control, 0.58 +/- .02 mL/min/kg, P less than 0.001), and production rate (PR) of calcitriol (14.2 +/- 1.0 ng/kg/d v control, 31.8 +/- 3.2 ng/kg/d, P less than 0.001) were significantly lower in patients with moderate renal failure (average creatinine clearance, 0.59 +/- 0.01 mL/s [35.1 +/- 6.1 mL/min]) when compared with the respective values of normal control subjects. The MCR of calcitriol was determined again in patients with renal failure after they received calcitriol, 1 microgram/d, for 1 week. The MCR remained unchanged (0.46 +/- .04 mL/min/kg, n = 7) and plasma levels of calcitriol were increased to 34.6 +/- 2.77 pg/mL. The mechanism by which the MCR of calcitriol decreases in renal failure is partly due to the presence of inhibitory factors of degradation enzymes in uremic plasma. When the ultrafiltrates of uremic plasma obtained from hemodialysis patients were infused to normal Sprague-Dawley rats, the MCRs of calcitriol (0.20 +/- .01 mL/min/kg, n = 6) were markedly suppressed in comparison to those of rats infused with the ultrafiltrates of normal plasma (0.37 +/- .01 mL/min/kg, n = 6, P less than 0.001). The uremic plasma also contained factors that inhibit the synthesis of calcitriol. We conclude that metabolic degradation of calcitriol is decreased in patients with renal failure, and uremic plasma contains inhibitory factors that suppress the synthesis and degradation of calcitriol.