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A Hadj-Aïssa

Publications and source records attributed to A Hadj-Aïssa.

5 recordsLinked to original sources

Influence of the level of hydration on the renal response to a protein meal.

Recent studies have suggested that the renal effects of high protein intake could be mediated, at least in part, by vasopressin and/or an increase in the urinary concentrating activity. The present study investigated the influence of the level of hydration, and hence of the activity of the concentrating process, on the renal response to an acute oral protein load. Clearance studies were performed before (Control) and during three hours after a protein meal (1.5 g/kg body wt protein as cooked meat) in ten healthy volunteers. This study was performed twice at a two to three week interval under either constant low (LowH) or high (HighH) hydration. In spite of the marked difference in initial diuresis (3.1 +/- 0.3 in LowH vs. 13.9 +/- 0.7 ml/min in HighH) and urine osmolality (501 +/- 42 in LowH vs. 99 +/- 3 mOsm/kg H2O in HighH), a similar relative decrease in urine flow rate was observed following the meal in both conditions. TcH2O increased progressively by 70% in LowH whereas CH2O decreased by 40% in HighH. Plasma vasopressin showed a progressive increase with time in LowH (from 1.10 +/- 0.26 in control, to 1.98 +/- 0.35 pg/ml at the third hour after the PM, P < 0.05) but not in HighH (0.53 +/- 0.09 to 0.70 +/- 0.17 pg/ml). Glomerular filtration rate (inulin clearance) increased significantly on the second post-prandial hour under LowH but not under HighH. Excretions rates of Na, Cl, K, and urea increased after the meal, however, not to the same extent nor with the same time course in the two conditions. Significant positive correlations were observed between GFR and TcH2O, urine osmolality, or the ratio of urine-to-plasma urea concentrations in LowH. These results suggest that the protein-induced hyperfiltration is partially blunted by a high water intake, and hence is dependent, directly or indirectly, on the urine concentrating activity.

Adult

Acute renal failure with preserved renal plasma flow induced by cancer immunotherapy.

Adoptive immunotherapy in patients with advanced cancer produces significant regression of metastatic disease in selected patients, but it is complicated by severe side effects. Prevention of these complications is still limited because their precise mechanisms remain unknown. For this reason we have investigated renal function and hemodynamic parameters in 16 patients with renal cell carcinoma before and during treatment with a combination of high doses of both recombinant interleukin-2 (rIL2) and recombinant alpha-interferon. After patients had received three injections of combined immunotherapy, there was a decrease in mean blood pressure (-20%), glomerular filtration rate (-25%), urine output (-50%), and fractional sodium excretion (-0.8%). This was associated with an increase in heart rate (+30%), plasma creatinine level (+30%), fractional potassium excretion (+14%) and microalbuminuria (+130%). However, renal plasma flow remained constant. The increment in microalbuminuria may reflect an alteration of glomerular capillary permeability. The reduction in GFR may be accounted either for a decrease in efferent to afferent arteriolar resistance ratio, leading to a decrease in glomerular capillary pressure, or for a decrease in ultrafiltration coefficient, or both. Nonsteroidal antiinflammatory drugs, such as ketoprofen, used to minimize side effects, could considerably worsen renal function and should be avoided in patients treated by rIL2. Our results bring new insights into the pathogenesis of functional acute renal failure and provide a rational basis for the use of vasopressors in the treatment of cytokine-induced acute renal failure.

Acute Kidney Injury

Microalbuminuria is acutely increased during anesthesia and surgery.

Microalbuminuria is known to increase in various diseases with potential repercussion on the kidneys and indicates an increase in glomerular intracapillary pressure or changes in permeability characteristics. In this study, we measured whether albumin excretion is affected in patients undergoing anesthesia and surgery, which are both known to induce dramatic changes in renal function and in the release of vasoactive substances such as catecholamines, vasopressin, angiotensin, and prostaglandins. Seven patients with normal renal function and physiological microalbuminuria prior to surgery were studied. Urine samples were collected before anesthesia, just before the beginning of surgery, and thereafter 30 min following incision, and 30 min after the end of surgery. Anesthesia induced a significant increase in microalbuminuria, which further increased during surgery. After the end of surgical procedure, microalbuminuria decreased but remained significantly higher than control. This phenomenon may be due to an increase in intracapillary glomerular pressure and/or an alteration in glomerular permeability induced by a direct effect of drugs, or to the action of vasoactive substances on the glomerular structure.

Adult