Publications by authors named "Kopple J"

This study evaluated the potential contribution of the liver to glucose intolerance and insulin resistance in acute uremia. Eight bilaterally nephrectomized dogs and eight sham-operated dogs were studied, while awake, 24 to 30 hours after surgery. Blood levels and hepatic balance of glucose, lactate, and amino acids were measured during a baseline period and during a 90-minute infusion of glucose and insulin that maintained plasma glucose at 9 to 10 mmol/L.

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An increase in plasma insulin-like growth factor I (IGF-I) levels by growth hormone injection or IGF-I infusion can raise renal plasma flow and glomerular filtration rate. However, it is not known whether a more physiological stimulus for IGF-I will also increase IGF-I in the kidney and whether the increase in renal or serum IGF-I is correlated with the increase in renal plasma flow and glomerular filtration rate. Male rats were pair fed either a high-protein (36% protein, N = 9) or a low-protein but isocaloric diet (9% protein, N = 9) for 10 to 14 days.

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Since carnitine deficiency has been reported in some patients undergoing maintenance hemodialysis, we studied the effects of intravenous infusion of L-carnitine or placebo at the end of each dialysis treatment. The trial, which lasted seven months (one month baseline, 6 months treatment) was multicenter, double blind, placebo controlled, and randomized. Eighty-two long-term hemodialysis patients, who were given either carnitine (N = 38) or placebo (N = 44), completed this study.

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Previous studies have reported conflicting results of carnitine supplementation on plasma lipids in patients with chronic renal failure. We therefore performed a four center, double-blind placebo controlled trial to evaluate the effects of post-hemodialysis intravenous injection of L-carnitine in ESRD patients on maintenance hemodialysis. Thirty-eight patients received up to six months of L-carnitine infusions (20 mg/kg) post-dialysis and 44 patients received placebo infusions.

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To evaluate the effects of long-term total parenteral nutrition (TPN) on eye function, 27 adults and 12 children in the UCLA Home TPN Clinic underwent ophthalmoscopic examination and visual-function testing. Direct inspection of the fundus showed a marked granularity of the retinal pigmented epithelium in some patients. About one-half of the children and one-third of the adults tested had at least one and usually two abnormalities in their electroretinogram.

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Thirty-four adults undergoing long-term parenteral nutrition (TPN) were treated either with or without intravenous taurine for less than or equal to 24 mo. Statistical comparisons were carried out in eight patients randomly assigned to receive intravenous taurine, usually 10 mg.kg-1.

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People in developed nations such as the United States and Canada have an increased risk of colon cancer. Fecal mutagens have been detected in the feces of individuals at high risk for colon cancer. We describe a rapid, sensitive, reliable, reproducible high-pressure liquid chromatography (HPLC) method for detecting fecapentaenes, the most active and chief mutagen found in human stool.

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There is growing evidence that taurine is a biologically valuable nutrient. However, there are few published data concerning the taurine content of different foods. We measured the taurine content of 29 meats, including both cooked and uncooked samples, nine dairy products, 17 infant or adult-feeding solutions and 48 plant foods (including vegetables, nuts or seeds, fruits and legumes.

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To evaluate the contribution of the splanchnic area to the carbohydrate abnormalities associated with chronic uremia, the splanchnic exchange of glucose and gluconeogenic substrates was quantitated basally and after an iv glucose load in nine uremic patients with impaired glucose tolerance and seven control subjects. In the basal state, blood glucose and splanchnic glucose production were similar in the two groups. During glucose infusion (33 mumol/kg.

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Growth hormone increases renal plasma flow and glomerular filtration rate and reduces total renal vascular resistance. Evidence presented in this paper indicates that these effects of growth hormone are mediated by insulin-like growth factor I (IGF-I). Published literature indicates that growth hormone and IGF-I have a number of other physiological and morphological effects on the kidney.

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Although angiotensin-converting enzyme (ACE) inhibitors may lower urinary protein excretion, it is not known whether these agents can completely eliminate microalbuminuria. This study examined whether the ACE inhibitor, enalapril, can abolish low levels of microalbuminuria in diabetic patients. Six men with adult-onset, insulin-dependent diabetes mellitus, most of whom had low levels of microalbuminuria, were studied in a clinical research center, where they ate a controlled diet and performed regulated exercises daily.

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Peritoneal dialysate immunoglobulin (Ig)G concentrations were measured in 120 continuous ambulatory peritoneal dialysis (CAPD) patients evaluated at four dialysis centers in different countries to assess the normal range for dialysate IgG and to investigate the relationships of this protein levels with peritoneal episodes, For 65 of these patients, plasma IgG levels were determined, and IgG clearances were calculated. The mean dialysate concentration of IgG was 6.9 +/- 4.

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Taurine (2-aminoethanesulfonic acid) was evaluated as an antimutagen in the Ames Salmonella tester strain assay. Taurine inhibited mutagenesis by doxorubicin (-74%), bleomycin (-55%), mitomycin C (-56%), and 2-aminofluorene (-52%), but not danthrone or benzo(a)pyrene, in strain TA102. In strain TA98, doxorubicin mutagenicity, but not that of 2-aminofluorene or benzo(a)pyrene, was inhibited by taurine.

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There have now been many studies on the effects of growth hormone (GH) on renal function. Chronically elevated GH levels, such as occur in acromegaly, are associated with an increase in renal plasma flow (RPF), glomerular filtration rate (GFR) and kidney size. When GH falls in these individuals (such as, after hypophysectomy in acromegalic patients), RPF, GFR and renal size decrease.

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This study evaluated the nutritional status of 95 patients with chronic renal insufficiency who participated in the feasibility phase of the NIH funded Modification of Diet in Renal Disease (MDRD) Study. All patients were seen monthly by a physician and dietitian. After a baseline period, the patients were randomly assigned either to a mildly protein-restricted control diet or to one of three low protein, low phosphorus diets.

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Growth hormone is reported to increase renal plasma flow (RPF) and glomerular filtration rate (GFR) in some but not all studies. The discrepant results could be due to a delay in the effects of growth hormone on renal function. We therefore examined whether a growth hormone injection does increase RPF and GFR, whether this increase is delayed, and whether elevation in RPF and GFR is associated with increased plasma levels of insulin-like growth factor I (IGF-I).

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Although maintenance hemodialysis (MHD) patients are often wasted, little is known about their dietary energy needs. We studied four men and two women in a clinical research center while they received diets providing 45, 35 and 25 kcal/kg desirable body weight/day; diets were fed, in random order, for 21 to 23 days each. Protein intake, 1.

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The mechanisms whereby growth hormone may increase renal plasma flow (RPF) and GFR are not known, but circumstantial evidence has implicated insulin-like growth factor I (IGF-I) as a mediator of this effect. This study examined whether an infusion of IGF-I will increase RPF and GFR, whether this effect occurs quickly, and if this effect is dependent on eicosanoids or peptide hormones known to affect renal function. Rats fasted for 3 d to reduce IGF-I and IGF-I plasma binding proteins were anesthetized; then the rats received an intravenous injection of 25 micrograms/kg IGF-I, and an infusion of 25 micrograms/kg IGF-I within 20 min.

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A prospective study was undertaken to assess the utility of the renal biopsy as a tool in the clinical practice of nephrology. Nephrologists performing this procedure were surveyed concerning prebiopsy diagnosis, plans for therapy and estimation of prognosis, before and after biopsy results were disclosed. On the basis of 108 specimens from both academic centers and community hospitals, clinical and pathological diagnoses differed in 63% and therapeutic approach was altered in 34% of the cases.

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Nonsteroidal anti-inflammatory drugs (NSAIDs), such as indomethacin, suppress renal prostaglandins and markedly reduce renal perfusion and diuretic response in some renal disorders. Mild renal impairment may occur in healthy subjects. Pharmacodynamic characteristics of certain NSAIDs, such as the nonacetylated salicylates, suggest that they may have less deleterious renal effects.

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This study examined whether patients with insulin-dependent diabetes mellitus and normal renal function have an altered response to an amino acid infusion when they are pretreated with a converting-enzyme inhibitor. Three groups of adults received amino acid infusions for 20 min on two occasions separated by a 240-min interval. Groups 1 (6 normals) and 2 (6 diabetics) ingested captopril (12.

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Plasma amino acid concentrations were measured in 15 children aged 4-65 months who received home parenteral nutrition (PN) and in 10 normal controls. In seven patients (Group I), PN was the only source of nutrition. Eight patients (Group II) ingested 30%-70% of their total energy requirements and received the remainder intravenously.

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