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Biomedical subjects

B Lacour

Publications and source records attributed to B Lacour.

At least 199 records · Page 11Linked to original sources
PubMed1985

Effect of oral carnitine supplementation on disturbances of lipid metabolism in the uremic rat.

Carnitine deficiency has recently been incriminated in the pathogenesis of the disturbed lipid metabolism observed in hemodialysis patients. The present study was performed to investigate the effects of L-carnitine administration on the lipid metabolism of rats with experimental chronic renal failure as compared to normal rats. Three groups of rats were studied: the first had induced chronic uremia, the second was sham-operated and pair-fed with the first, and the third was sham-operated and fed ad libitum. Serum triglycerides were significantly higher in uremic rats than in control animals of both groups. In addition to triglycerides, serum total cholesterol and phospholipids were also increased in uremic rats. The fractional clearance rate of Intralipid [K2(%)] was decreased in uremic as compared to control animals. The in vivo oxidation of radiolabeled palmitate was lower in uremic than in ad libitum-fed control animals but not lower than in pair-fed control rats. The daily oral administration of L-carnitine to uremic rats was associated with stable serum triglycerides. On the contrary, serum triglycerides increased significantly in the untreated uremic rats over the same period of time. Serum total cholesterol and phospholipids remained similar in the presence and the absence of L-carnitine treatment. The intravenous fat tolerance test of carnitine-supplemented uremic rats improved slightly, although not significantly, when compared to that of untreated uremic rats. In conclusion, oral L-carnitine supplementation in chronically uremic rats had only modest or no effects on several plasma lipid parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1985

Renal magnesium and phosphate wastage in a patient with hypercalciuria and nephrocalcinosis: effect of oral phosphorus and magnesium supplements.

We report a 29-year-old man with a mild decrease in glomerular filtration, nephrocalcinosis, hypercalciuria and a renal magnesium leak. He had other features of 'congenital magnesium-losing kidney', such as arthritis and hyperuricemia, short stature and recurrent urinary tract infections, but had no radiological chondrocalcinosis. In addition, pallidal calcification was found. The patient also had a renal phosphate leak. Phosphorus supplements resulted in a decrease in urinary calcium excretion, indicating that hypercalciuria was at least partially a consequence of phosphorus depletion. Plasma and urine magnesium were not affected by phosphorus supplements. Addition of magnesium supplements resulted in a transient and modest decrease in urinary calcium excretion, with no modification in plasma magnesium.

Administration, Oral↗
PubMed1985

Comparison of several atherogenicity indices by the analysis of serum lipoprotein composition in patients with chronic renal failure with or without haemodialysis, and in renal transplant patients.

We investigated serum lipoproteins in uraemic and kidney transplant patients, and compared the results with those from normal persons. In uraemic patients, with or without haemodialysis, and in kidney transplant patients, the ratio of HDL-cholesterol to total cholesterol minus HDL-cholesterol, the ratio of HDL-phospholipids to total phospholipids minus HDL-phospholipids, and the ratio of apolipoprotein A to apolipoprotein B are all decreased, though to different extents, when compared with healthy control subjects. Furthermore, important differences exist in the relative HDL composition between the 3 patient groups and healthy control subjects. Thus, the ratio of apolipoprotein A/HDL-cholesterol and that of HDL-cholesterol/HDL-phospholipids are significantly altered in uraemic haemodialyzed patients, while the ratio of apolipoprotein A/HDL-phospholipids is normal. By contrast, the 3 ratios are normal in uraemic undialyzed patients, and the 2 ratios, apolipoprotein A/HDL-cholesterol and apolipoprotein A/HDL-phospholipids are normal in renal transplant patients. The last ratio, HDL-cholesterol/HDL-phospholipids, is increased in this group of patients. Thus, it appears that HDL-cholesterol, HDL-phospholipids, and total apolipoprotein A represent different aspects of the same lipoprotein. The determination of all three parameters could lead to a different approach in the evaluation of the so-called cardiovascular risk, at least for uraemic patients and renal transplant patients.

Arteriosclerosis↗
PubMed1985

[Inorganic pyrophosphates and parathormone in hypophosphatasia. Study of a family].

The serum concentration of parathormone is usually normal in hypophosphatasia, a rare disease with a defect of bone mineralisation and low serum alkaline phosphatase activity. Nevertheless there are three cases in the literature presenting a hyperparathyroidism with or without hypercalcemia. No anomaly of parathyroid was found at autopsy. The authors describe the first cases of hypophosphatasia with low serum concentration of parathormone and raise the possibility of a trouble in the calcium-parathormone feed-back. They also emphasize the interest of the urinary pyrophosphate excretion. Its increase seem to be the most constant and the most specific biological disorder.

Adult↗
PubMed1985

Does vitamin K excess induce ectopic calcifications in hemodialysis patients?

Vitamin K promotes the formation of gamma-carboxylated glutamic acid (Gla) residues within different protein classes such as vitamin K-dependent clotting factors, bone Gla-protein (BGP or osteocalcin), and atherocalcin. Gla-containing proteins have a high affinity for the Ca2+ ion. In addition to bone and atheromatous plaques they are also regularly found in ectopic calcifications, but not in uncalcified soft tissue. In the present study we investigate the possibility that vitamin K and BGP, in addition to previously recognized factors, may play a role in soft tissue calcification of chronic hemodialysis patients. Patients without radiovisible ectopic calcifications (group A) are compared to patients with such Ca deposits (group B). Both patient groups have comparable values of predialysis plasma Ca, P, alkaline phosphatases, parathyroid hormone (PTH) and 25 hydroxyvitamin D. The CaxP product is slightly higher in group B than in group A patients. Plasma vitamin K1 levels of group B patients are increased to more than twice the values observed in group A patients. Plasma BGP, even though not significantly different, shows a trend towards decreased levels in group B patients. A positive correlation exists between plasma vitamin K1 and BGP for patient group A alone, but not for group B alone. A correlation is also observed between plasma PTH and BGP (all patients) and between serum alkaline phosphatases and plasma BGP (all patients). Taken together, these results favor the hypothesis that in addition to an increased CaxP product a vitamin K excess may induce soft tissue calcification in hemodialysis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Immune lysis of hepatocytes in culture: accurate detection by aspartate aminotransferase release measurement.

Determination of the immune lysis of epithelial cells, especially of hepatocytes, in short term culture is dealt with inadequately because of the lack of accuracy inherent in most classical methods of measurement of cell lysis or because of the high spontaneous release of the lytic marker. We have studied different methods of detection of lysis of rat hepatocytes cultured for a short term (24-48 h) at a concentration of 10 000 cells/50 microliters. The determination of aspartate aminotransferase (ASAT) release, measured with a centrifugal analyser parallels lactate dehydrogenase (LDH) release and trypan blue dye staining which are indisputable markers of cell death, but ASAT release is a more sensitive determination. Surprisingly, 51chromium release (1.72%/h) is much higher than ASAT release (0.51%/h) for an experimental period of 24 h. In cell mediated cytotoxicity tests, the ASAT content of lymphocytes, in contrast to that of LDH, is much lower than that of hepatocytes and this makes determination of ASAT release a sensitive marker of cytotoxicity under these conditions.

Animals↗
PubMed1984

Determination of placental alkaline phosphatase phenotypes by starch-gel and acrylamide gel electrophoresis.

The polymorphism of placental alkaline phosphatase (ALP) is usually studied by butanol extraction followed by starch gel electrophoretic separation at two different pH's, 8.6 and 6.0. Acrylamide gel electrophoresis (7.5%) in the presence of Triton X-100 is shown to be preferable in speed, reliability and reproducibility of results. All the placental ALP phenotypes detected had the same molecular mass by gradient acrylamide electrophoresis. The enzyme butanol extract is not sufficiently pure to enable the different placental ALP's to be distinguished by isoelectric focusing on polyacrylamide gels.

Alkaline Phosphatase↗
PubMed1984

[Incidence of lithiasic recurrence after a diuretic therapy, alone or combined with treatment by a thiazide diuretic or phosphorus].

The preventive affects on recurrent renal calcium stones of water diuresis alone or combined with drugs aimed at lowering urinary calcium were evaluated prospectively in 51 patients with calcium nephrolithiasis. Following clinical and metabolic examination, the patients were allocated at random to 3 treatment groups: water diuresis alone (group I, n = 19) or associated with hydrochlorothiazide 50 mg/day (group II, n = 19) or with a neutral phosphate preparation 1500 mg/day (group III, n = 13). Results were assessed on the number of recurrences; 24-h urinary calcium was measured at regular intervals. The mean follow-up (2 years; range 1-4 years) was the same in all 3 groups. A significant fall in recurrence rate as compared with pre-treatment values was observed in groups I and II. The recurrence rate was the same in both groups during treatment. However, less patients had recurrences in group I (1/19) than in group II (5/19). No significant fall in recurrence rate was observed in group III, owing to some patients in this group having frequent recurrences. The recurrence rate was unrelated to clinical findings and biochemical values ( oxaluria , calciuria) measured before treatment and to the urinary Ca/Cr ratio calculated during treatment. This study confirms that water diuresis is effective in preventing recurrent renal calcium stones and that diuretics of the thiazide group reduce the number of patients with recurrences.

Adult↗
PubMed1984

Total parathyroidectomy and delayed parathyroid autotransplantation using a simplified cryopreservation technique: human and animal studies.

Following earlier studies using a simplified cryopreservation method in rats, we report the successful use of this technique in a hemodialysis patient who had previously undergone total parathyroidectomy. In additional studies, parathyroid glands from rats were conserved by this rapid freezing procedure after total parathyroidectomy. Six weeks after parathyroid autotransplantation the animals were submitted to a low-calcium diet and their parathyroid gland function compared to that of rats that had previously undergone sham operation, immediate autotransplantation, or delayed autotransplantation using the classical cryopreservation method. With both cryopreservation techniques, plasma calcium, phosphorus, and 1,25 (OH)2 vitamin D concentrations after low-calcium diet were similar although results were less satisfactory than with immediate autotransplantation or after sham operation. We suggest that this simplified cryopreservation technique, developed in rats, yields functioning parathyroid gland tissue and can be successfully used in the human.

Adult↗
PubMed1984

[Comparative variations in natriuresis and urinary calcium in patients with hypercalciuric lithiasis treated with thiazide diuretics].

Because of the close relation between sodium (Na) and calcium (Ca) tubular reabsorption, restriction of sodium intake has been proposed in hypercalciuric stone formers. We simultaneously measured urinary concentrations of both ions in 30 recurrent stone formers (19 male, 11 female, mean age 40,8 +/- 10,2 years) with fasting hypercalciuria, before and after reduction of calciuria using long-term thiazide (TZ) treatment associated with moderate restriction of calcium intake, without concomitant Na restriction. No recurrence of stones was observed in this group with a 12 to 49 month follow-up. UCa strongly correlated with UNa in both conditions. However, UCa significantly decreased with TZ (128 +/- 32 vs 73 +/- 26 mumol/kg/day, p less than 0.001), whereas neither UNaV (190 +/- 60 vs 202 +/- 57 mmol/day) nor diuresis significantly varied. We conclude that calciuria can be lowered without reduction in Na intake in hypercalciuric stone formers controlled by thiazide treatment.

Adult↗
PubMed1984

[Effects of intravenous urography using sodium and meglumine ioxitalamate (Telebrix 38) on blood creatinine and urinary excretion of N-acetyl-beta-D-glucosaminidase].

We evaluated the effect of intravenous pyelography (IVP) with sodium ioxitalamate and meglumine (Telebrix 38) on serum creatinine levels and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG). Both values were significantly elevated 24 and 48 hours following intravenous pyelography. The increase of urinary NAG however, was much greater than that of the serum creatinine level. In patients with normal serum creatinine levels prior to the IVP, urinary NAG was very elevated at 24 hours and had returned to almost normal values 48 hours after intravenous pyelography. On the contrary, urinary NAG was increased at 48 hours as well as at 24 hours in patients with chronic renal failure following administration of Telebrix 38. It was not possible to demonstrate any correlation between NAG urinary excretion and the amount of iodinated contrast material administered, even in patients with normal renal function.

Acetylglucosaminidase↗
PubMed1984

Modification in the renal phosphate handling after oral administration of glucose to conscious rats.

We studied the modification of tubular reabsorption of phosphate (TRPi) in conscious rats given glucose either intravenously or orally. These rats served as their own controls, and were also compared to rats given vehicle intravenously or orally. 30-min urine collections were performed just before the administration of glucose or vehicle, and 15 and 75 min afterwards. Plasma was sampled at the end of each urine collection. Plasma glucose (PG) increased significantly in rats given glucose either intravenously or orally. Intravenous administration of glucose reduced TRPi slightly but significantly, a result also observed in control rats infused with vehicle. On the other hand, a significant decline in TRPi was noted in rats given oral glucose whether or not they had been fasted for the preceding 24 h, but not in those given oral vehicle. The maximal decrease in TRPi was of the same order of magnitude in both fasted and nonfasted rats given glucose orally, although it was delayed in the latter group and significantly higher than in rats infused with glucose. These results suggest a relationship between some factor secreted concomitantly with the ingestion of glucose and the renal handling of phosphate.

Animals↗
PubMed1983

Pyridoxal 5'-phosphate deficiency in uremic undialyzed, hemodialyzed, and non-uremic kidney transplant patients.

In this study, we have investigated plasma pyridoxal 5'-phosphate (PLP) concentrations in undialyzed and dialyzed uremic patients and in kidney transplant subjects, using an enzymatic technique with thermal deproteinization to liberate PLP from plasma proteins. The specificity of the reaction indicates no interference with pyridoxal and only 3% interference with pyridoxamine phosphate. In 17 hemodialyzed patients, a deficiency of about 50% of plasma PLP concentration is found as compared to 25 healthy subjects (22.2 +/- 2.47 vs. 48.8 +/- 3.00 nmol . l-1), as mean +/- SEM). In seven undialyzed uremic patients with end-stage renal failure, the plasma PLP concentration is also decreased (29.3 +/- 1.74 nmol . l-1). The absence of PLP in plasma ultrafiltrates demonstrates that no loss of PLP occurs due to hemodialysis. The daily oral supplementation with 250-750 mg pyridoxal induces a supraphysiological increase in plasma PLP concentration in hemodialyzed as well as in undialyzed patients. In 116 non-uremic kidney transplant subjects, the mean plasma PLP concentration was 33.8 +/- 3.50 nmol . l-1). In 65% of these patients, a marked deficit (below 20 nmol . l-1) was observed. In conclusion, uremic patients have a deficient vitamin B6 state. Its correction with pyridoxal to restore physiological plasma PLP concentration necessitates oral supplementation with lower doses that those widely used at present. In kidney transplant patients a similar plasma PLP deficiency is observed in the absence of chronic renal failure.

Adult↗
PubMed1983

[Urinary excretion of lithogenic substances in hospitalized patients with calcium lithiasis. Physiopathologic meaning and prognostic value].

The urinary excretion of various substances involved in kidney stone formation was evaluated in 67 patients with hypercalciuric lithiasis (HCl), 36 lithiasis patients with normal calciuria (NCl) and 21 controls without urinary stones. All subjects were hospitalized for 3 days and given a calcium, phosphorous and sodium-controlled diet. The 24-hour urine volume was significantly larger in the HCl and NCl groups than in controls. The 24-hour Ca, Na and uric acid excretion was significantly greater in the HCl group than in the NCl and control groups. Oxalate and pyrophosphate excretion was the same in all three groups. Urinary Ca correlated with urinary creatinine in the HCl and control groups, but the slope and ordinate of the regression line were significantly higher in the former group. Similarly, urinary Na correlated with urinary creatinine in the HCl and control groups with a significantly steeper slope in the HCl group. These data are suggestive of abnormalities in the tubular reabsorption of Ca and Na in HCl patients. Finally, there was no correlation between the values obtained and the activity of the disease, as evaluated by the finding of at least 3 urinary stones or one staghorn calculus during the 5 years preceding the study. It is concluded that measurements of Ca, Na, uric acid, creatine, oxalates and phosphates during a stay in hospital provide pathophysiological information but cannot be taken as indices of urolithiasis activity.

Calcium↗