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Biomedical subjects

A Girault

Publications and source records attributed to A Girault.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Dissociation of hypotensive and renal hemodynamic effects of an angiotensin converting enzyme inhibitor in insulin-dependent diabetic patients with incipient nephropathy].

The mechanism of action of angiotensin converting enzyme (ACE) inhibitors on urinary albumin excretion (UAE) in diabetics is controversial. In order to dissociate the hypotensive and intrarenal effects, 16 insulin-dependant diabetics with permanent microalbuminuria (30-300 mg/24 h) without hypertension were given Ramipril, a long acting ACE inhibitor, at hypotensive (treatment A 5 mg/day; N = 8) and at sub-hypotensive doses (treatment B, 1.25 mg/day; N = 8) over a 6 week period in parallel double-blind study. Blood pressure, UAE, glomerular filtration renal blood flow (continuous 125I-Iodothalamate + 131I-Hippurate infusion) and converting enzyme activity (Liebermann's method), before and after treatment. In treatment group A, the blood pressure fell from 133 +/- 5/79 +/- 4 (mean +/- SE) to 125 +/- 4/77 +/- 2 mmHg (p less than 0.05 for systolic blood pressure) whereas it remained stable in treatment group B (132 +/- 7/79 +/- 4 to 128 +/- 5/80 +/- 4 mmHg). The UAE decreased in both groups: group A from an average of 74 (40-198) to 47 (5-202) mg/24 h (p = 0.07; group B, from an average of 77 (50-136) to 19 (15-120) mg/24 h (p less than 0.005), as did ACE activity: group A from 332 +/- 44 to 163 +/- 33 iu/l (p less than 0.004), group B from 423 +/- 39 to 191 +/- 28 iu/l (p less than 10-4).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[In vitro effects of 1,25-dihydroxycholecalciferol on alkaline phosphatase and gamma-glutamyltransferase activity in hypophysectomized rats].

Effects in vitro of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) on alkaline phosphatase (PAL), gamma-glutamyltransferase (gamma-GT) and acid phosphatase (PAC) activities were investigated on renal cortex from hypophysectomized rats. In these animals the biosynthesis of 1,25-(OH)2D3 and the specific activities of kidney PAL and gamma-GT were decreased. The course of these effects was determined from 45 min to 8 h. In the presence of 1,25-(OH)2D3 (2 x 10(-6) M) a delayed (5h) but simultaneous stimulation of the three enzymes was observed. It reached a maximum at 6h and disappeared at 8h. The dose-response relation was studied at 6h. In the presence of 1,25-(OH)2D3 (5 x 10(-7) M), the three enzymes were activated. The effect was maximal at 10(-6) M; it was +22% for PAL, +17% and +15% respectively for gamma-GT and PAC compared with controls. Cycloheximide suppressed the induction of PAL but not of gamma-GT activity. The effects of the secosteroid on renal enzymes seems to be a pharmacological more than a physiological one.

Acid Phosphatase↗
PubMed1990

[Urinary excretion of albumin and lipid abnormalities in hypertensive insulin-dependent diabetics].

Patients with insulin dependent diabetes mellitus (IDDM) often suffer from cardiovascular diseases as renal failure occurs. Elevated albumin excretion rate (AER) is a predictive value of this event. Relations between AER, blood pressure, serum lipids and apoproteins concentrations in 100 patients with IDDM have been surveyed. Twenty one hypertensive patients (HT group) were compared to 21 patients without hypertension (n HT group), matched for sex, age, diabetes duration, and metabolic control, assessed by glycosylated haemoglobin. Comparison of both groups showed HT group had elevated systolic blood pressure (137 +/- 12 vs 126 +/- 20 mmHg; p less than .05), elevated diastolic blood pressure (80 +/- 7 vs 71 +/- 8 mmHg; p less than .001), increase in AER (27 range 3-4023 vs 6 range 2-51 mg/day; p less than .001), slightly elevated serum creatinine (95 +/- 32 vs 78 +/- 15 mumol/l; p less than .05). In HT group, serum lipid composition showed: raise in total cholesterol (251 +/- 43 vs 221 +/- 41 mg/dl; p less than 0.5), elevated apoprotein B (130 +/- 30 vs 99 +/- 21 mg/dl; p less than .001) elevated apoprotein B/apoprotein A1 ratio (.91 +/- .32 vs .66 +/- .27; p less than .001), elevated triglycerides (157 +/- 53 vs 98 +/- 43 mg/dl; p less than .005) and elevated LDL-cholesterol (170 +/- 42 vs 143 +/- 33 mg/dl; p less than .05). Levels of apoprotein A1 and HDL-cholesterol were not significantly different. Body mass index, daily insulin requirement and tobacco usage were similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Use of 6 serum pools in standardization of the determination of apolipoproteins AI and B in the human serum].

The proliferation of commercial immunoassays for the determination of apolipoproteins AI and B as parameters of risk for coronary heart disease and the discordance between the values obtained with the systems have made more urgent than ever the need for standardization of these assays. The authors report here the results of a collaborative study on the standardization of the values between the "Comité Française de Coordination des Recherches sur l'Athérosclérose et le Cholestérol (ARCOL)" and 13 Companies providing 15 different analytical systems. The results show that standardized measurements are not possible using a "consensus international standard" and that the major problem is related to the enormous variability of the analytical systems. In contrast, the present study demonstrates that six different serum pools containing increasing amounts of apolipoproteins AI and B can be used to generate a common reference curve which permits calibration of all immunoassays and standardization of results.

Apolipoprotein A-I↗
PubMed1989

Reactivity of HDL subfractions towards lecithin-cholesterol acyltransferase. Modulation by their content in free cholesterol.

(1) Human HDL2 (d 1.070-1.125) and HDL3 (d 1.125-1.21) labelled with unesterified [14C]cholesterol, were incubated with a source of lecithin-cholesterol acyltransferase. For optimal activity, the reaction required the addition of albumin in excess, at least 3-times greater than the concentration of HDL-free cholesterol. Under such conditions, the reaction appeared saturable. HDL3 was found the most efficient substrate and the Vmax values expressed for 1.5 IU LCAT/ml and with an albumin/free cholesterol ratio of 3, were 8.3 nmol free cholesterol esterified/ml per h and 4.1 nmol/ml per h for HDL3 and HDL2, respectively. (2) HDL3 were modified in the presence of VLDL by inducing triacylglycerol lipolysis with a semipurified lipoprotein lipase from bovine milk. The newly formed HDL had gained free cholesterol and phospholipids, so that about 50% of these modified HDL, referred to as light-LIP-HDL3, were reisolated in the HDL2 density range. Light-LIP-HDL3 were enriched mostly in free cholesterol (+ 160%) and in phospholipid (+ 40%). Their reactivity towards LCAT was half-reduced compared to parent HDL3, which correlated well with a decrease in their phospholipid/free cholesterol molar ratio. Moreover, HDL3 artificially enriched in free cholesterol and exhibiting a comparable PL/FC behaved like lipolysis-modified HDL in their reactivity towards LCAT. (3) HDL3 were also modified by co-incubation with VLDL (post-VLDL-HDL3), or with VLDL and a source of lipid transfer protein (CET-HDL3). The latter treatment greatly affected the lipid composition of the core particle (-25% esterified cholesterol, +190% TG). In both cases, the moderate decreasing LCAT reactivity observed could be related to the phospholipid/free cholesterol ratio. Thus, like in artificial substrates, the lipid composition of the HDL surface may control the rate of LCAT-mediated cholesterol esterification.

Animals↗
PubMed1989

[In vitro stimulation of alkaline phosphatase and gamma- glutamyltransferase in the kidney of hypophysectomized rat by the mixture of 1,25 and 24,25 dihydroxycholecalciferols].

The present study was undertaken to investigate the in vitro effects of two cholecalciferol metabolites 1,25(OH)2CC and 24,25(OH)2CC on the renal cortex alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT) and acid phosphatase (ACP) activities in hypophysectomized rats. We found that both 1,25-CC and 24,25-CC stimulated ALP and GGT. An additive effect was obtained on ALP and GGT after incubation with one with the other metabolites. When 1,25-CC was used alone, it increased ACP; in presence of 24,25-CC, this stimulating effect disappeared. In the rat, together 1,25-CC and 24,25-CC correct in vitro ALP and GGT activities decreased by hypophysectomy. Physiological signification of these effects remains again unknown.

24,25-Dihydroxyvitamin D 3↗
PubMed1989

Effects of keto-analogues on phosphocalcic and aminoacid metabolism in dialysed patients: a crossover study.

It has been suggested that calcium salts of keto-analogues (KA) have beneficial effects on phosphocalcic and aminoacid (AA) metabolism. To confirm this, their short-term effects were evaluated on chronic dialyzed patients. In a prospective, randomised, crossover study, eight and seven patients were put on KA (200 mg/kg/d) and assigned either a low-protein diet (LP:0.4 g/kg/d) or a normal one (NP: 1 g/kg/d) for 15 days. The two treatments were interchanged after 15 days of washout. KA.LP was accompanied by: a) decreases in calorie intake (12%; p = 0.001) and in blood concentrations of albumin (5%, p = 0.004), urea (32%, p = 0.001), phosphate (29%, p = 0.001), parathormone (27%, p = 0.008), isoleucine (24%, p = 0.04), 1 and 3 methyl-histidine (71%, p = 0.03; 24%, p = 0.005), valine (19%, p = 0.004) and hydroxyproline (85%, p = 0.009); b) increases in calcemia (9%, p = 0.002), cystathionine (991%, p = 0.0001) and threonine (22%, p = 0.04). KA.NP was accompanied by: a) decreases in phosphatemia (15%, p = 0.03) and parathormone (18%, p = 0.06); b) increases in calcemia (9%, p = 0.002), cystathionine (427%, p = 0.0001), and phenylalanine (28%, p = 0.013). Calcium salts of keto-analogues together with a low or normal protein diet thus seem to reduce blood concentrations of phosphates and parathormone, and raise calcium; however their action on aminoacids needs further investigation.

Aged↗
PubMed1988

Membrane fluidity of Toxoplasma gondii: a fluorescence polarization study.

Toxoplasma gondii membrane fluidity was investigated by fluorescence polarization. We used 1,6-diphenyl 1,3,5-hexatriene (DPH) as a fluorescent hydrophobic probe. Fluorescence anisotropy (r) and degree of order (s) showed high fluidity properties. Chemical analysis was performed on this parasite. We found a low cholesterol/phospholipid ratio, many unsaturated fatty acids chains, and high phosphatidylcholine and low sphingomyelin amounts. These results were in good agreement with the observed high fluidity. This may be related to the great adaptability of Toxoplasma gondii in infesting a wide variety of host cells.

Animals↗
PubMed1987

[Prognostic value of the early determination of plasma volume in arterial hypertension during pregnancy].

The authors have estimated the maternal plasma volume ine 243 patients by undertaking 282 calculations. The samples were taken often a fairly long time before the delivery, the mean being 4.05 weeks and the maximum being 16 weeks. The results were compared between normal pregnancies and those with hypertension that had no effect on the mother or fetus. The increase in the plasma volume was however significantly far less when the hypertension was severe or when there was intra-uterine growth retardation, either by itself or in association with hypertension. There is a positive correlation between the plasma volume and the fetal weight and thus a good index of normal growth can be worked out. Measuring the plasma volume, therefore, can be used as an early screening technique for severe hypertension with high risk for the fetus.

Birth Weight↗
PubMed1986

Toxoplasma gondii: demonstration of intrinsic peroxidase activity during lacto-peroxidase mediated radioiodination of tachyzoites.

Tachyzoites of Toxoplasma gondii have been radioiodinated under various conditions with or without lactoperoxidase, with glucose oxidase being used to generate hydrogen peroxide. Erythrocytes were iodinated simultaneously as a control. In our conditions, tachyzoites were more intensely labelled in the absence of lactoperoxidase. This result can be explained by the existence of an intrinsic peroxidase activity which interfere with the exogenously added enzyme during surface radioiodination.

Animals↗
PubMed1983

Absence of functional messenger RNA for glycogen phosphorylase in the muscle of two patients with McArdle's disease.

(1) Two unrelated cases of McArdle's disease (glycogen storage disease type V, deficiency in muscle-type glycogen phosphorylase, EC.2.4.1.1) with no detectable inactive protein, and two heterozygous relatives of one patient, have been investigated for the presence or absence of functional messenger RNA. Methods were developed and scaled down to be compatible with clinical-size biopsies. (2) Total muscle RNA was prepared and translated in a rabbit reticulocyte cell-free system. Neosynthesized products were isolated by immunoaffinity microchromatography. Phosphorylase was compared with control enzymes neosynthesized and purified under the same conditions. (3) No functional mRNA for phosphorylase could be detected in the muscles of the two patients. A decreased amount of messenger for phosphorylase, compared with the control enzymes, was found in the muscles of the two heterozygotes. (4) Exploration of functional messenger RNA in clinical enzymopathies should be readily adaptable to a number of enzymatic diseases.

Adolescent↗