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Biomedical subjects

A Hadj-Aissa

Publications and source records attributed to A Hadj-Aissa.

29 records · Page 2Linked to original sources
PubMed1987

Cyclosporine A nephrotoxicity: evidence for mesangial foam-cells in dogs.

Nephrotoxicity of cyclosporine A was studied in dog after 3 weeks' administration of the drug at high doses (20 mg/kg/day). Cyclosporine A concentrations measured in different organs revealed a high ratio between renal tissue and plasma. Renal histopathology showed non-specific tubular lesions and glomerular modifications. There were lipids in the mesangial cells which took on a foamy aspect. Ultrastructural study and lipid staining confirmed these findings, and non-specific esterase reaction revealed no macrophagic infiltration. Using anti-CSA antibodies it was not possible to demonstrate CSA in the mesangial cells. This alteration has never been described before in CSA therapy and its meaning is not clear; however, it does suggest that there occur modifications in the lipid metabolism or in the phagocytic function of the mesangial cells when cyclosporine A is administered over long periods.

Animals↗
PubMed1986

Acute renal effects of beta-blockers.

The effects on renal function of a single dose of six different beta-blockers (atenolol, propranolol, metoprolol, acebutolol, nadolol, and pindolol) have been evaluated in 51 hypertensive patients with normal glomerular filtration rate (GFR). Most drugs, except pindolol, induce a 10-20% decrease in GFR and renal plasma flow, although differences in the magnitude and the pattern of this fall are evident. The fractional excretion of sodium is generally depressed by 20-40%. These data suggest a limited renal tolerance of most beta-blockers during acute administration, irrespective of their pharmacological characteristics.

Adrenergic beta-Antagonists↗
PubMed1986

Surgical versus medical treatment in renovascular hypertension. Retrospective study of 166 cases.

A retrospective study of 166 cases of renovascular hypertension was performed. Before 1979, 114 patients were treated for renovascular hypertension. Forty underwent surgery. In this group, therapy resulted in cure or improvement in 45% of the patients. Seventy-four patients underwent medical therapy: 88% of these patients had improvement of blood pressure when beta-blockers were used, but only 41% when they were not. More recently (from 1979 to 1983), 52 patients were treated for renovascular hypertension, of which 31 patients have been operated for fibromuscular renal artery stenosis (62%) or atherosclerotic renal artery stenosis (32%). In this group, 90% of the patients were considered to be cured or improved with a mean follow-up of 36 months. Eighteen of thirty-one patients underwent autotransplantation with satisfactory results on blood pressure control. Twenty-one patients were treated by antihypertensive drugs: 86% of the patients were improved or cured (71.5% of the patients had atherosclerotic lesions) with a mean follow-up of 46.8 months.

Adult↗
PubMed1986

[Course of renal function in malignant hypertension. Effect of treatment. Study of 30 cases followed for 5 to 18 years].

Renal insufficiency is the most frequent complication of malignant hypertension (MHT). The initiation of effective hypotensive treatment is generally followed by a rapid improvement of renal functions, but the long-term evolution has been only rarely studied. A group of 30 patients was retrospectively selected on the following criteria: Malignant hypertension: mean DBP 138 +/- 20 mmHg, hypertensive retinopathy stage III-IV; Early renal insufficiency: mean Inulin clearance (CIN) 66 +/- 26 ml/min, mean PAH clearance (CPAH) 364 +/- 161 ml/min; Clinical and functional follow-up ranging from 5 to 18 years. Among these patients, two groups were defined according to the quality of BP control: good or fair responders (GR) with a DBP always less than 110 mmHg, poor responders (PR) with a DBP occasionally greater than or equal to 110 mmHg. The results show in the two groups an improvement of CIN at 3 years, followed by a stabilization then a decrease after the 6th year. However the early improvement is significantly lower in PR. Despite similar initial values (GR = 54.7 +/- 31.3; PR = 51.4 +/- 13.2), CIN remains always lower in PR (at 9 years = GR 72.4 +/- 30.6; PR 56.0 +/- 19.8). During the first 3 years, CPAH increases in GR, whereas it decreases in PR, resulting in significantly different values at 3 years. At 9 years, CPAH remains improved in GR (329.1 +/- 109.3 vs 281.7 +/- 173.8 initially) but decreased in PR (256.0 +/- 166.9 vs 307.3 +/- 119.5 initially). The parallel improvement of CIN and CPAH in GR confirms a favorable effect of BP control on early vascular lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Renal glucose transport after kidney transplantation.

Tubular maximal transport of glucose (TmG), plasma glucose threshold ( PGT ) and fractional maximal tubular reabsorption (TmG/GFR) were measured in fourteen kidney-grafted patients. Seven patients showed decreased PGT and normal or decreased TmG/GFR (type A or B renal glycosuria (RG) ), whereas seven other patients showed normal values. No difference was found between the two groups with respect to parameters of renal function and to clinical parameters characterizing kidney transplantation. The only difference observed between the two groups was the rate of decrease of plasma creatinine levels during the 1st week after transplantation: it was faster in the group without renal glycosuria. No difference was seen between the two groups of patients with respect to the number of rejection episodes occurred over the first 12 months.

Adult↗
PubMed1983

Ranitidine kinetics in chronic renal impairment.

The effects of moderate to severe renal impairment on kinetics of the H2-blocker ranitidine were investigated in 16 patients divided into two groups. Mean inulin clearance (ClIn) was 35 +/- 18.3 ml/min/1.73 m2 in group I and 7.4 +/- 3.5 ml/min/1.73 m2 in group II. Each patient received a single 150-mg oral dose of ranitidine. Values determined were maximum plasma concentration (MC) and time of occurrence, AUC, elimination t 1/2 (t 1/2 beta), total amount of unchanged ranitidine recovered in urine, and ranitidine renal clearance (ClR). MC values were higher and longer delayed than values reported in subjects with normal renal function. The t 1/2 beta was longer in group I and group II and correlated with the degree of renal impairment. The amount of ranitidine excreted within the first 24 hr decreased (18% of the dose in group I and 6% of the dose in group II), and ClR correlated strongly with ClIn, indicating that the observed changes in ranitidine kinetics are mainly related to changes in its renal excretion.

Adult↗
PubMed1982

Ranitidine kinetics in normal subjects.

A 1-mg/kg IV bolus injection and a 150-mg (one tablet) oral dose of ranitidine were given to seven normal subjects. At least 1 wk separated the two doses. Ranitidine disappeared from plasma with a half-life of about 2.5 hr. Half of the oral dose was effectively absorbed and half of the absorbed amount was found unchanged in urine. Total body clearance was 10.1 ml/min/kg. Urinary clearance was the same after oral and intravenous doses (6.4 and 6.9 ml/min/kg, P greater than 0.10). Intravenous ranitidine kinetics included three phases, with a central distribution volume of 0.2 l/kg and a total distribution volume of 1.2 l/kg. Absorption kinetics were apparently order zero: of the 150-mg dose, 75 mg was absorbed during 5 hr at a constant rate of 15 mg/hr.

Administration, Oral↗
PubMed1980

Activity of a new high efficiency diuretic in man: piretanide (HOE 118).

1 The pharmacological actions of piretanide, a new high efficiency diuretic, were studied in sixteen patients with GFR (inulin clearance) varying from 0.1--2.5 ml/s. 2 After hydration and following two control periods, a single dose of 6 mg piretanide was ingested. Thereafter, urine was collected every 30 min for 2 h and every hour for the next 4 h. Fluid losses were replaced. 3 The following measurements were made: urine flow rate, clearances of inulin, PAH, urea, creatinine, uric acid, osmolar and free water clearances, excretion rates of sodium, chloride, potassium, calcium, phosphate, bicarbonate, ammonium, titratable acidity and urine pH. 4 Main results showed piretanide was efficient in the group with normal GFR (inulin clearance greater than 1.5 ml/s) and in the group with slightly decreased GFR (1.0 less than inulin clearance less than 1.4 ml/s), in terms of diuresis, natriuresis, kaliuresis and calciuresis. It was inefficient in the group with severe renal insufficiency (inulin clearance less than 0.3 ml/s). 5 Free water clearance showed preservation of diluting ability to a large extent. 6 In the three groups, no significant change in inulin clearance and PAH clearance occurred.

Adult↗
PubMedDate not supplied

[Improving the interlaboratory variation for creatinine serum assay].

PURPOSE: To assess inter-assay variation and accuracy of blood creatinine measurements as well as the effect of the standardization of the calibration procedures on inter-assay variation. METHODS: Inter-assay variation and accuracy were assessed using 30 frozen human sera and 3 certified reference materials, which were analysed by 17 creatinine assays (colorimetric: 12, enzymatic: 4, HPLC: 1). Usual calibration procedure was compared with two common calibration procedures using either a reference material (404.1 micromol/L), or secondary sera calibrators (69, 115 et 180 micromol/L). RESULTS: Most of the commercially available methods display inaccuracy, > 10% for creatininemia < 150 micromol/L in most cases. For this concentration range, the mean creatininemia was statistically significantly different as a function of the assay used (p < 0.001). Enzymatic assays produced lower results than colorimetric ones for low creatinine levels but higher results for high creatinine levels. Assays being calibrated according to the manufacturer's recommendations, the median dispersion factor was 14% for the 20 samples between 45 and 150 micromol/L, and 8% for the 10 samples between 250 and 350 micromol/L. The calibration procedure modified inter-assay variation significantly (p < 0.001) but we gained little advantage from both common calibration procedures. A significant decrease of inter-assay variation occurred within each technical group (colorimetric or enzymatic) when a common calibration was performed using calibrators which concentration(s) was(were) close to the concentrations to be measured. CONCLUSIONS: Inter-assay variation is too high to allow prediction of glomerular filtration rate (GFR) or creatinine clearance from serum creatinine level. Our results highlight the interest of a calibration procedure using several concentrations with at least one between 90 and 150 micromol/L. The marketing of such a calibrator should be considered in order to decrease inter-assay variation in the range of creatinine levels which defines a mild chronic renal failure. Such an approach will certainly reduce inter-assay variation only within each technical group but could allow to include technical group as a co-variable in the algorithms developed for predicting GFR or creatinine clearance. A global transferability will certainly need the correlation of all types of creatinine assays versus a definitive method, whom definition remains uncertain.

Blood Chemical Analysis↗