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Biomedical subjects

V de Précigout

Publications and source records attributed to V de Précigout.

At least 19 recordsLinked to original sources
PubMed2002

[Does nutrition affect the prognosis of aged hemodialysis patients?].

Most authors agree that the prevalence of malnutrition is increased in patients treated by dialysis, particularly in the elderly. Malnutrition is a powerful risk factor for mortality; however, the strong association between nutritional status and mortality does not mean a causal relationship. It has been proposed that nutritional disorders that may occur in dialysis patients are mainly related to two different mechanisms. The first type of malnutrition is associated with a low protein and energy intake due to uremic toxicity, to physical changes and to psychosocial and psycho economic factors frequently found in the elderly. The second type of malnutrition is associated with increased protein catabolism from inflammatory origin. In the later case there are strong interactions between atherosclerotic cardiovascular disease, inflammation and nutritional parameters. Up to now the treatments have aimed at improving nutritional intake by increasing dialysis doses in association with dietary counselling and protein/calories supplementation. Complementary anti-inflammatory therapies acting on the inflammatory component of malnutrition may have a beneficial effect on the outcome of these patients.

Biomarkers↗
PubMed2000

No change of hyperleptinemia despite a decrease in insulin concentration in patients with chronic renal failure on a supplemented very low protein diet.

Chronic renal failure (CRF) is often accompanied by hyperleptinemia caused by deficient renal metabolism of leptin and possibly increased leptin production, which in turn may result from the hyperinsulinemia and increased proinflammatory cytokine levels in patients with CRF. The hyperinsulinemia and insulin resistance observed in patients with CRF improve on supplemented very low protein diets (SVLPDs). The goal of our study is to determine whether the correction of hyperinsulinemia and insulin resistance in patients with CRF by SVLPDs is accompanied by improvement in hyperleptinemia. Thirteen patients were studied before and 1 year after following SVLPDs providing 0.3 g/kg/d of protein, supplemented with amino acids and ketoanalogues. After 1 year, patients showed markedly less hyperinsulinemia (7.4 +/- 1.6 versus 13.8 +/- 2 microU/mL at the start of diet; P: = 0.05) and insulin resistance, whereas serum leptin levels remained unchanged (16.1 +/- 4.7 versus 19.1 +/- 7.4 ng/mL at start of the study; P: = not significant). The initial correlation between serum leptin level and percentage of body fat persisted during follow-up. No correlation was found between insulin and leptin levels or between the variation of these two parameters during the study. Our study shows that the correction of hyperinsulinemia and insulin resistance in patients with CRF by SVLPDs is not accompanied by improvement in hyperleptinemia, which consequently does not appear to result from changes in carbohydrate metabolism.

Dietary Proteins↗
PubMed1999

Outcome of nutritional status and body composition of uremic patients on a very low protein diet.

Concern has been raised about the nutritional adequacy of a very low protein diet (VLPD). Monthly clinical evaluation by a physician and dietitian and quarterly dietary records, anthropometric measurements, blood testing, and dual energy X-ray absorptiometry (DEXA) were used to assess the course of nutritional status for 1 year in 10 clinically stable patients (six men, four women; age, 57.1 +/- 9.3 years) with advanced chronic renal failure (mean glomerular filtration rate, 13.2 +/- 4.8 mL/min/1.73 m(2)). These patients received a VLPD providing 0.3 g/kg/d of protein and were supplemented with amino acids and ketoanalogues. Conventional nutritional markers remained unchanged after 1 year of the VLPD. However, during the same period, whole-body DEXA showed a significant decrease in lean tissue from 46.2 +/- 10.2 to 45.0 +/- 9. 8 kg (P < 0.02); limb-trunk lean tissue ratio was reduced from 0.86 +/- 0.12 to 0.82 +/- 0.12 (P < 0.02), total-body fat increased from 20.0 +/- 6.9 to 21.4 +/- 7.0 kg (P < 0.05), and the percentage of total-body fat increased from 29.2% +/- 8.7% to 31.7% +/- 8.8% (P < 0.03). These different modifications occurred abruptly during the first 3 months, then stabilized or slightly improved thereafter. These mild changes do not appear to be deleterious given the favorable long-term outcome of these patients, even after they began treatment by dialysis or after renal transplantation.

Absorptiometry, Photon↗
PubMed1999

Volume flow measurement in hemodialysis shunts using time-domain correlation.

Volume flow was measured in 58 hemodialysis shunts (32 grafts and 26 radial fistulas) using the color velocity imaging-quantification method. This method is based on time-domain correlation for velocity calculation and integration of time-varying velocity profiles generated by M-mode sampling. Measurements were made in the brachial artery to estimate radial fistula flow or directly in the grafts. Intraoperator reproducibility was 14.9% for fistulas and 11.6% for grafts. Flow rate was significantly lower in abnormal shunts associated with a functional disorder or a morphologic complication (808 ml/min +/- 484) than in shunts associated with no abnormalities (1401 ml/min +/- 562). Receiver operating characteristic curves showed that a flow rate of 900 ml/min for fistulas and 1300 ml/min for grafts provided 81% and 79% sensitivity and 79% and 67% specificity, respectively. A functional disorder or a morphologic complication was associated with all fistulas and grafts in which flow rates were lower than 500 ml/min and 800 ml/min, respectively.

Adolescent↗
PubMed1996

Improvement in lipid profiles and triglyceride removal in patients on polyamide membrane hemodialysis.

Cardiovascular morbidity and mortality in hemodialyzed patients are increased due to the frequently abnormal lipid metabolism. It has been reported that this abnormal lipid metabolism could be partially corrected by some highly permeable membranes, such as polysulfone or cellulose triacetate. We investigated the influence of 4 months of dialysis with a polyamide membrane upon the course of lipid parameters in 6 patients presenting a hypertriglyceridemia > 2 mmol/l while on bicarbonate dialysis with a cellulose membrane. Lipid parameters improved after 4 months of hemodialysis with a polyamide membrane. Serum triglyceride and cholesterol levels decreased, while HDL cholesterol and HDL levels rose significantly (p < 0.05). Apolipoprotein B decreased significantly (p < 0.05). Following heparin administration, lipoprotein lipase activity improved (p < 0.02), associated with a decrease apolipoprotein C3 (p < 0.05). The fractional clearance rate of triglycerides rose significantly (p < 0.01). The use of highly permeable polyamide membranes results in a significant improvement in lipid disturbances of dialysis patients due to an increased lipoprotein lipase activity, induced perhaps by the removal of circulating inhibitors such as apolipoprotein C3.

Apolipoproteins↗
PubMed1996

[Role of phosphorus in hyperparathyroidism secondary to non-dialysed adult chronic renal insufficiency].

Secondary hyperparathyroidism (HPT II) occurs early in the course of chronic renal failure (CRF), mainly because of decreased calcitriol levels, low levels of serum calcium, retention of phosphorus, abnormal parathyroid gland function and hyperplasia, and peripheral resistance to the action of parathormone (PTH). Amongst these factors, phosphorus retention plays a crucial role in moderate and advanced CRF, by inhibiting renal calcitriol synthesis, lowering serum calcium levels and stimulating PTH secretion. In patients with mild CRF, phosphorus restriction prevents the development of HPT II by increasing renal calcitriol secretion. In patients with advanced CRF, the suppressive effect of phosphorus restriction may be obtained independent of any changes in plasma calcitriol levels, suggesting a direct effect of phosphorus on parathyroid function. Phosphorus restriction should be used in the early stages of CRF, together with a sufficient intake of calcium in the form of phosphorus chelating salts. When phosphorus and calcium serum concentrations are normalised but PTH levels are not in the target range, 1 alpha hydroxy vitamin D3 derivatives may be used, with a careful monitoring to avoid high serum levels of phosphorus or calcium.

Adult↗
PubMed1995

Evaluation of red blood cell lipoperoxidation in hemodialysed patients during erythropoietin therapy supplemented or not with iron.

To investigate the effects of erythropoietin (rHuEPO) therapy supplemented or not with iron on hemolysis in hemodialysed patients (HD) we evaluated lipoperoxidation (LPO) by assaying (i) the red blood cell (RBC) antioxidant enzymatic system including superoxide dismutase (SOD), glutathione peroxidase, and catalase (Cat), (ii) RBC polyunsaturated fatty acids (PUFA) and (iii) malondialdehyde (MDA). Group 1 included 12 HD patients, group 2 had 7 HD patients with iron supplementation, group 3 comprised 12 HD patients with rHuEPO therapy and group 4 included 9 HD patients with both iron and rHuEPO therapies. No LPO was found in group 1 as regards MDA and PUFA levels. However, SOD and Cat activities were significantly elevated as compared to controls (p < 0.001). In the second group, a significant decrease in PUFA percentage was observed, particularly in 20:4(n-6) and 22:4(n-6) (the main ones involved in LPO) as compared to the other groups, whereas total MDA level was higher than that of the other groups. Similarly a decreased SOD activity was observed as compared to group 1 (p < 0.001), indicating its inactivation subsequent to an hyperproduction of reactive oxygen species through iron injection. In groups 3 and 4 no change was observed in MDA levels or PUFA percentages indicating no LPO. However, marked differences were observed in the enzymatic defense system. Particularly in group 3, SOD and Cat activities decreased when compared to group 1 (p < 0.001) whereas the association of erythropoietin and iron (group 4) increased the three enzymatic activities (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Long-term control of hyperparathyroidism in advanced renal failure by low-phosphorus low-protein diet supplemented with calcium (without changes in plasma calcitriol).

Phosphorus (Pi) retention linked to chronic renal failure (CRF) favors secondary hyperparathyroidism (HPT). Reduction of Pi and protein intake has been shown to prevent the development of HPT in CRF. The aim of the present study was to assess in patients with advanced CRF the long-term effects on phosphate and calcium metabolism of a low-Pi (5-7 mg/kg/day), low-protein (0.4 g/kg/day) diet providing 300 mg/day calcium (Ca) and supplemented with amino acids and ketoacids, Ca carbonate (400-800 mg/day) and vitamin D2 (1,000 IU/day). Twenty-nine patients with advanced CRF (glomerular filtration rate (GFR) 13.7 +/- 4.5 ml/min) were selected for the study, on the basis of a follow-up of a least 2 years and a satisfactory compliance to the prescribed diet. At the start of the study, biological evidence of HPT was present with increased plasma PTH concentration (144 +/- 95 pg/ml), increased plasma Pi (1.57 +/- 0.33 mmol/l), an increase in alkaline phosphatase activity and plasma osteocalcin concentration. Plasma PTH concentration was positively correlated with plasma Pi and inversely with plasma Ca concentrations and GFR. Pi and protein restriction induced a significant correction of HPT within 3 months after starting the diet. After 2 years of diet, despite the diminution of GFR (11.1 +/- 3.7 ml/min, p < 0.0001), plasma PTH was still lower than at the start of the diet (88 +/- 57 pg/ml, p < 0.01), as was plasma Pi (1.32 +/- 0.24 mmol/l, p < 0.001), total plasma Ca being higher (p < 0.01). Plasma PTH levels were correlated only to plasma Ca concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Correction of chronic metabolic acidosis in haemodialysed patients by acetate-free biofiltration does not influence parathyroid function.

In eight patients remaining acidotic after more than 1 year of bicarbonate haemodialysis, we studied the effect of correcting the chronic metabolic acidosis using acetate-free biofiltration for 4 months on the course of secondary hyperparathyroidism. An AN69 capillary membrane was employed with a bicarbonate infusion rate initially set at 1.8 l/h in all patients and then adjusted in each one to obtain a predialysis bicarbonate of > or = 23 mmol/l. Standard blood chemistry parameters were determined every 2 weeks. Measurements of PTH, calcifediol and calcitriol, as well as calcium-PTH curves were determined at the beginning and end of the study. While acetate-free biofiltration appears to be an adequate technique for the correction of chronic metabolic acidosis when bicarbonate dialysis fails, this study indicates that it does not influence secondary hyperparathyroidism in haemodialysed patients. The level of intact PTH did not vary significantly and the calcium-PTH curves at 0 and 4 months were superimposable with no significant differences in the set point and the slope of the curves.

Acidosis↗
PubMed1995

[Nutrition and continuous ambulatory dialysis].

Nearly 50% of patients treated by CAPD develop a more or less severe state of denutrition with which morbidity and mortality are closely linked. Though many biological and biophysical examinations have been proposed to evaluate the nutritional status of patients, it appears that, from a practical standpoint, the information furnished by the medical history, anthropometric parameters, nitrogen balance and serum protein levels are sufficient. The prevention and/or treatment of this malnutrition can only be achieved by correcting the two principal contributing factors which are the reduced energetico protidic supply (especially protidic) and the inadequate dialysis in connection particularly with the progressive loss of the residual renal function.

Blood Proteins↗
PubMed1995

Clinical evaluation of an optimized 1.1% amino-acid solution for peritoneal dialysis.

A significant percentage of dialysed patients have inadequate protein intake. One strategy for treating the protein malnutrition in peritoneal dialysis patients is to replace glucose in the dialysis solution by amino acids. A new peritoneal dialysis solution containing 1.1% amino acids in a formulation optimized for renal patients and with a lactate concentration of 40 mmol/l has been evaluated. Fifteen CAPD patients completed a non-randomized prospective 3-month study. Each patient received 2 litres of the optimised 1.1% amino acid solution for the second exchange of the day with a dwell time of 5-6 h. Indicators of efficacy were serum albumin and transferrin. After 3 months of intraperitoneal amino acids, serum albumin levels significantly increased from 32.7 +/- 2.3 to 35.1 +/- 2.2 g/l (mean +/- SD; P < 0.01). This occurred in parallel with a significant increase in transferrin levels from 2.21 +/- 0.26 to 2.39 +/- 0.27 g/l (P < 0.05). As expected, urea rose from 23.7 +/- 6.8 to 29.9 +/- 9.4 mmol/l. Interestingly bicarbonate did not change (25.5 +/- 4.2 versus 25.2 +/- 3.3 mmol/l). These results suggest that the optimized formulation is effective in improving nutritional parameters in CAPD patients while avoiding unwanted side-effects such as acidosis.

Adult↗
PubMed1994

Granulocyte activation and adhesion molecules during hemodialysis with cuprophane and a high-flux biocompatible membrane.

Hemodialysis with complement-activating membranes, such as cuprophane, induces neutropenia and expression of the granulocyte adhesion receptor Mac-1 (CD11b/CD18), while hemodialysis with noncomplement-activating membranes does not. Increased expression of CD11b by neutrophils may mediate cuprophane-induced leukopenia. However, the rebound granulocytosis that follows leukopenia is not fully understood. Ten patients on regular hemodialysis were included in a cross-over study. Hemodialysis was performed for 2 weeks with cuprophane and 2 weeks with polyamide, a high-flux noncomplement-activating membrane. At the end of each period, the following parameters were determined during a hemodialysis session: C5a concentration by enzyme immunoassay and the neutrophil expression of CD11b, LFA-1 (CD11a/CD18), and the antigen recognized by MoF11 (MoF11 Ag), a monoclonal antibody that recognizes activated neutrophils, by immunofluorescence flow cytometry. Hemodialysis with cuprophane induced an increase in C5a concentration and in the expression of CD11b and MoF11 Ag, which were maximal after 15 minutes of hemodialysis, at the nadir of neutropenia. CD11b expression was maintained throughout hemodialysis, despite the reversal of neutropenia. Conversely, after peak expression, C5a and MoF11 Ag decreased as the neutrophil count increased to baseline values. Polyamide hemodialysis did not induce variations in C5a concentration, nor in CD11b and MoF11 Ag expression. CD11a/CD18 expression remained stable during hemodialysis with both membrane types. Neutrophil activation, as determined by MoF11 Ag expression, was correlated with the evolution of neutrophil count and C5a concentration during cuprophane hemodialysis, while CD11b expression was not correlated with neutrophil count throughout dialysis. A decrease in neutrophil activation could explain in part the detachment of neutrophils previously bound to endothelium and, therefore, the reversal of neutropenia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Comparison of different monitoring techniques for vascular access in chronic hemodialysis].

Aim of the study was to compare different techniques of monitoring for vascular accesses in our chronic hemodialysis patients. Twenty seven patients (14 men, 13 women) were investigated. The accesses studied consisted of 19 arteriovenous fistulas and 8 vascular protheses. Twenty-four were trouble free, venous pressure was high in two, one was difficult to puncture. Three measurements of recirculation percentage were made for each patient, as well as a color Doppler flow imaging, and a digital angiography of the access. Recirculation measurements were normal for all patients including those with functional abnormalities. A stenosis was found 9 times with the Doppler and 10 times by angiography, there being disagreement between the two techniques in one case. The location of the stenosis was the same in the 9 concordant cases. There was a very strong correlation between the degree of stenosis found using the two techniques (p < 0.0001). In conclusion, measurement of recirculation appears to us to be of no interest for verifying a vascular access. On the other hand, the color Doppler seems to be an excellent choice for detecting an abnormality. An arteriographic confirmation seems necessary before correction.

Adolescent↗
PubMed1993

[Cystine lithiasis and its treatment with d-penicillamine. The experience in a nephrology service in a 23-year period. Apropos of 26 patients].

From 1968 through 1990, 26 patients with cystine lithiasis were followed-up for a mean of 10.6 +/- 6.7 years in the department of Nephrology of the Pellegrin Hospital in Bordeaux, France. Clinical and surgical features in these patients are reported as well as the experience acquired with the use of D-penicillamine over the 23-year study period. Long-term D-penicillamine treatment can be used in patients with cystinuria and is both effective and safe. Use of other thiol compounds for preventing cystine stone formation was not necessary in our patients.

Adolescent↗