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Biomedical subjects

M Labeeuw

Publications and source records attributed to M Labeeuw.

At least 37 records · Page 2Linked to original sources
PubMed1993

31P NMR spectroscopy investigation of muscle metabolism in hemodialysis patients.

Calf muscle metabolism of six patients with end-stage chronic renal failure undergoing maintenance hemodialysis and of six control subjects was studied using 31P nuclear magnetic resonance spectroscopy at 4.7 Tesla. Spectra were obtained at rest, during exercise and recovery. At rest, the inorganic phosphate, ATP and phosphocreatine concentrations, and the intracellular pH were similar in both groups of subjects. In the patients, the maximum workload achieved at the end of exercise led to a 84% and 46% depletion of phosphocreatine and ATP, respectively; under this condition, the intracellular pH fell to 6.50 +/- 0.09. In control subjects, a maximum workload caused no change in ATP concentration at the end of exercise, but a phosphocreatine depletion and an intracellular pH fall similar to those observed in the patients. Although the rate of phosphocreatine depletion during exercise was not different in the two groups of subjects, the decrease in intracellular pH was more rapid in the patients than in control subjects. At the end of maximum exercise, the rates of recovery of both phosphocreatine and intracellular pH were significantly reduced in the muscle of hemodialysis patients when compared to normal subjects. These results suggest that, in the calf muscle of hemodialysis patients, energy production via oxidative metabolism is impaired and compensated for by an increase in anaerobic glycolysis.

Adenosine Triphosphate↗
PubMed1993

Is erythropoietin treatment safe and effective in myeloma patients receiving hemodialysis?

Still few data are available on efficacy and safety of recombinant erythropoietin (rEPO) in patients with myeloma and end-stage renal failure (ESRF); two such hemodialysed patients are reported in whom only partial response was observed, despite iron, folic acid supplementation and, in one case, high doses of rEPO (320 IU/kg/week). Despite improvement in well being and no need of further transfusion, hemoglobin did not reach 80 g/l. One patient developed recurrence 4 weeks after starting rEPO. Patients with ESRF and myeloma should benefit from rEPO but particular attention should be paid to marrow proliferation.

Anemia↗
PubMed1992

Controlled low protein diets in chronic renal insufficiency: meta-analysis.

OBJECTIVE: To determine whether low protein diets retard the development of end stage renal disease. DESIGN: Meta-analysis of 46 trials since 1975, from which six randomised controlled trials were selected. SETTING: Five trials in Europe and one in Australia between 1982 and 1991. SUBJECTS: 890 patients with mild to severe chronic renal failure who were followed up for at least one year. 450 patients received a low protein diet and 440 a control diet. INTERVENTION: Difference in protein intake between control and treated groups of at least 0.2 g protein/kg/day. MAIN OUTCOME MEASURE: Number of renal deaths (the necessity to start dialysis or death of patient during study). RESULTS: 156 renal deaths were recorded, 61 in the low protein diet group and 95 in the control group, leading to an odds ratio of low protein to control of 0.54 with a 95% confidence interval of 0.37 to 0.79. CONCLUSIONS: This result, obtained on a large population of patients suffering from chronic renal insufficiency, strongly supports the effectiveness of low protein diets in delaying the onset of end stage renal disease.

Adolescent↗
PubMed1992

Renal venous erythropoietin concentrations in hypertensive patients with unilateral renal disease.

In 24 hypertensive patients with unilateral renal disease, the erythropoietin (Epo) concentration ratio in the renal veins was compared with the renin ratio. Seven patients showed moderately elevated peripheral Epo values. Epo and plasma renin activity were significantly positively correlated both in peripheral and renal veins. This suggests that the reduction of renal blood flow was a common, but not unique, stimulating factor of Epo and renin secretion. Epo ratio appeared insensitive since it was greater than 1.5 in only 30% of patients with a renin ratio > 2. Our results indicate that the Epo concentration ratio in renal veins cannot be proposed as a substitute for the currently used renin ratio.

Adolescent↗
PubMed1991

Stress-induced renal functional alterations in normotensives.

This study was performed to assess changes in renal function accompanying cardiovascular responses to mental stress. Glomerular filtration rate (GFR, inulin clearance), renal plasma flow (RPF, PAH clearance), filtration fraction (FF), sodium excretion, and segmental sodium tubular reabsorption (lithium clearance) were measured in 15 normal volunteers during rest and stress. The psychological stress test used is based on a computerized version of the Stroop word color conflict test. Stress induced a significant (P less than .05) and sustained increase in blood pressure and heart rate. During stress, GFR and RPF did not change whereas FF increased significantly (P less than .05) and sodium excretion tended to decrease. The decrease in sodium excretion was due to a significant (P less than .05) increase in proximal reabsorption, which may be mediated by renal hemodynamic changes. The observed significant increase in FF suggests an increase in postglomerular arteriolar resistances, which may account for the increase in proximal sodium reabsorption through an alteration in peritubular Starling forces. In the long run, the stress-associated increase in sodium reabsorption may contribute to the development of hypertension.

Adult↗
PubMed1991

Cystine stones: the impact of new treatment.

The hardness and frequent recurrence of cystine stones present a special challenge to the urologist. In this study, 15 cystinuric patients (11 males, 4 females; mean age 36 years, range 17-54) were treated and followed up over a period of 30 months (range 2-40). Most patients had previous history of open surgery. The diagnosis of cystinuria was confirmed by metabolic studies and infrared spectrometry of stones. Over the follow-up period recurrence was observed in 23 instances in 11 patients, leading to 38 "stone treatments" on 74 cystine stones. The percutaneous approach was used alone in 9 cases and in association with extracorporeal shock wave lithotripsy (ESWL) in 9 cases. ESWL was used alone in 18 cases. Medical treatment included high fluid intake, alkalinisation and Thiola (tiopronin, N-(2-mercaptopropionyl)glycine) in 6 patients. The overall stone-free rate assessed 3 months after treatment was 44.7%, which compares poorly with the rate for non-cystine stones. The recurrence rate is very high and instrumental treatment should not therefore be used excessively; it is indicated only for stones that are symptomatic or refractory to intensive medical therapy.

Adolescent↗
PubMed1991

[Diseases associated with renal amyloidosis. Apropos of 216 cases].

Diseases associated with renal amyloidosis were evaluated in 216 patients observed between 1956 and 1989. The percentage of secondary amyloidosis decreased from 72 to 47%, where it has remained for the past 20 years, despite the clear diminution in the tuberculosis rate; this is due to its increased incidence of association with rheumatoid diseases. Dysglobulinemia was found in more than 75% of the patients with AL amyloidosis. Amyloidosis associated with this dysglobulinemia, of which 30% were myelomatous, represented more than 25% of the cases observed during the past decade and constituted, with rheumatoid arthritis, the two most common etiologies.

Adolescent↗
PubMed1991

[Renal function during stress in hypertensive patients].

In this study, the measurement of blood pressure values, glomerular filtration rate (GFR, inulin clearance), renal plasma flow (RPF, PAH clearance), the filtration fraction (GFR/RPF), natiuresis and proximal sodium resorption (measured by lithium clearance), was performed at rest and during a computerised psychological stress test (Stroop word color conflict test) in 12 normotensive and 10 hypertensive subjects. The stress induced in the normotensives induced a significant increase of the filtration fraction and proximal tubule sodium resorption. The hypertensive kidney, submitted to a basal vasoconstriction greater than that of the normotensive kidney, does not react to stress. In the hypertensives, proximal sodium resorption occurs but is not significantly greater than at rest. In the long-term, the increased sodium resorption during stress could contribute to the development and the persistence of essential hypertension.

Adult↗
PubMed1991

[Treatment of cystine calculi using intra-urologic methods and extracorporeal lithotripsy].

The hardness and frequent recurrence of cystine stones represent a special challenge for the urologist. Fifteen cystinuric patients were treated in our department and followed over a mean period of 30 months. Most patients had a previous history of open surgery (1.5 pyelolithotomy/patient). Diagnosis of cystinuria was confirmed by metabolic studies and stone analysis. Over the follow-up period recurrence was observed in 23 instances in 11 patients thus leading to 38 stone treatments on 74 cystine stones. Stone size was less than 10 mm: 35 (47%); 10-20 mm: 21 (28%); 20-30 mm: 14 (19%); 30 mm: 4 (staghorn stones). A percutaneous approach was used in 9 cases as monotherapy (55% success) and in association with ESWL in 10 cases (50% success). ESWL was employed 18 times as monotherapy (39% success). Medical treatment included high fluid intake, alkalinisation and thiola in 6 patients. In conclusion, results obtained are poor in terms of stone clearance when compared to non-cystine stones. Recurrence rate is very high. Instrumental treatment should not be used excessively and is only indicated in symptomatic stones or refractory to intensive medical therapy.

Adolescent↗
PubMed1990

[Is it possible to use creatinine for following the development of renal insufficiency?].

Accurate methods of measuring glomerular filtration rate are usually considered as expansive and time consuming. Therefore, alternative methods (creatinine clearance, either calculated or measured, reciprocal plasma creatinine, slopes of creatinine vs time) have frequently been used to assess the rate of progression of renal failure and predict the time of dialysis. The present review underlines the limitations of such techniques frequently underestimated in recent trials intending to evaluate the potential benefit of protein restriction. It delimitates the restrictive conditions in which such methods could be used for clinical but not research purposes.

Creatinine↗
PubMed1990

Cyclosporin A-sensitive nephrotic syndrome preceding Hodgkin's disease by 32 months.

A 20-year-old man developed a massive nephrotic syndrome, rapidly complicated by pulmonary embolism and septicemia. Two renal biopsies taken 3 months apart showed minimal change glomerulonephritis. Treatment with prednisolone 1.5 mg/kg/day failed to induce a sustained remission, then monotherapy with cyclosporin A (CsA, 5 mg/kg/day) was started. Complete remission was obtained after 15 weeks. CsA was gradually tapered to 3 mg/kg/day. Twenty-two months after starting CsA, a routine examination disclosed a right sub-clavicular lymph node, of which histological examination showed a class 4 large cell Hodgkin's lymphoma. CsA was abruptly withdrawn and a polychemotherapy resulted in lymphoma remission after four courses. Ten months later, Hodgkin's disease is currently in remission and there is no relapse of proteinuria.

Adult↗
PubMed1989

The influence of renal insufficiency and haemodialysis on the kinetics of ciprofibrate.

1. The kinetics of the hypolipidaemic drug, ciprofibrate, were studied after a single oral dose (100 mg) in subjects with normal renal function (n = 6), patients with mild (n = 6) and severe (n = 6) renal insufficiency as well as in haemodialysed patients (n = 5). 2. Under fasting conditions, ciprofibrate, was absorbed rapidly in subjects with normal renal function, and its apparent elimination half-life was approximately 81 h. Both renal clearance (0.15 ml min-1) and cumulative renal excretion (less than 7% of the administered dose) were low. 3. Mild renal insufficiency did not alter the pharmacokinetics of ciprofibrate, but severe renal impairment significantly reduced both its renal clearance and cumulative urinary excretion and increased the apparent elimination half-life. 4. A 5 h haemodialysis session did not lower the plasma concentrations of ciprofibrate. 5. It is concluded that, from a pharmacokinetic point of view, a reduction in the dosage of ciprofibrate should be considered in patients with a glomerular filtration rate below 30 ml min-1/1.73 m2.

Adult↗