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Biomedical subjects

P Robitaille

Publications and source records attributed to P Robitaille.

64 records · Page 4Linked to original sources
PubMed1973

Relationship between deoxyribonucleoprotein and deoxyribonucleic acid antibodies in systemic lupus erythematosus.

A soluble preparation of nucleoprotein (sNP), a complex of native deoxyribonucleic acid (DNA) and histones, was isolated from calf thymus nuclei and labeled with [(125)I]iodide. Isotope-labeled antigen ([(125)I]sNP) was used in a primary binding radioimmunoassay method to detect antibodies to both sNP and native DNA. Sera with antibody to native DNA reacted with the DNA moiety of sNP and bound [(125)I] sNP, but this binding was completely inhibited by addition of unlabeled native DNA. Antibody to sNP which reacted with DNA-histone complex was not inhibited in the radioimmunoassay by addition of unlabeled DNA. Thus, antibodies to sNP and native DNA could be detected and differentiated by use of a single isotopically labeled antigen. In systemic lupus erythematosus (SLE), sera with binding to [(125)I]sNP was present in 21/36 (58%) patients. The majority (18/21) had antibodies to sNP and native DNA present simultaneously, one had antibody only to sNP and two had antibody only to DNA. In contrast, patients with other connective tissue diseases rarely showed binding to [(125)I]sNP. Serial studies on SLE patients showed that high serum binding to [(125)I]sNP paralleled renal disease activity as reflected by the degree of proteinuria. A fall in binding was observed with subsidence of renal disease and reappearance of increased binding coincided with exacerbation. In these patients, antibodies to sNP and DNA appeared or disappeared pari passu suggesting that in addition to the previously demonstrated role of antibody to native DNA, antibody to sNP might also be implicated in the pathogenesis of immunologically-mediated tissue lesions such as SLE nephritis.

Antibodies↗
PubMed1971

The effect of ketone bodies on renal ammoniogenesis.

Infusion of ketone bodies to ammonium chloride-loaded acidotic dogs was found to induce significant reduction in urinary excretion of ammonia. This effect could not be attributed to urinary pH variations. Total ammonia production by the left kidney was measured in 25 animals infused during 90 min with the sodium salt of D,L-beta-hydroxybutyric acid adjusted to pH 6.0 or 4.2. Ketonemia averaged 4.5 mM/liter. In all experiments the ammonia content of both urine and renal venous blood fell markedly so that ammoniogenesis was depressed by 60% or more within 60 min after the onset of infusion. Administration of equimolar quantities of sodium acetoacetate adjusted to pH 6.0 resulted in a 50% decrease in renal ammonia production. Infusion of ketone bodies adjusted to pH 6.0 is usually accompanied by a small increase in extracellular bicarbonate (3.7 mM/liter). However infusion of D,L-sodium lactate or sodium bicarbonate in amounts sufficient to induce a similar rise in plasma bicarbonate resulted in only a slight decrement in ammonia production (15%). The continuous infusion of 5% mannitol alone during 90-150 min failed to influence renal ammoniogenesis. Infusion of pure sodium-free beta-hydroxybutyric acid prepared by ion exchange (pH 2.2) resulted in a 50% decrease in renal ammoniogenesis in spite of the fact that both urinary pH and plasma bicarbonate fell significantly. During all experiments where ketones were infused, the renal extraction of glutamine became negligible as the renal glutamine arteriovenous difference was abolished. Renal hemodynamics did not vary significantly. Infusion of beta-hydroxybutyrate into the left renal artery resulted in a rapid decrease in ammoniogenesis by the perfused kidney. The present study indicates that ketone bodies exert their inhibitory influence within the renal tubular cell. Since their effect is independent of urinary or systemic acid-base changes, it is suggested that they depress renal ammoniogenesis by preventing the transformation of glutamine and glutamate into alpha-ketoglutarate in the mitochondria of the renal tubular cell.

Acetoacetates↗
PubMedDate not supplied

Long-term assessment of renal function under cyclosporine in pediatric heart transplant recipients.

Renal function was monitored in eight children who were long-term survivors of heart transplantation and who were treated with cyclosporine. Both creatinine clearance and true glomerular filtration rate remained normal 17 to 69 months after transplantation. The survival rate was 80% at 6, 12, and 24 months, and the rejection rate in survivors was only 0.37. Thus adequacy of renal function can be preserved, without jeopardizing overall transplant results, by using small doses of cyclosporine.

Azathioprine↗
PubMedDate not supplied

[Continuous peritoneal dialysis in children].

Thirty-two uremic children were treated by chronic peritoneal dialysis (CPD) since February 1982. Fifteen chose chronic ambulatory peritoneal dialysis (CCPD) while the 17 others were treated by continuous cycle peritoneal dialysis (CCPD). To this day, 10 patients (31%) are alive with a functioning kidney transplant, 16 (50%) are still treated by CPD awaiting a transplant, 5 have died (16%) and one went back to hemodialysis (3%). Complication in ranking order were peritonitis, mechanical drainage problems of the catheter and hernias. Linear growth was from good to excellent in the majority of patients. Globally, CPD was found to be attractive mainly because it allows a good quality of life.

Adolescent↗
PubMedDate not supplied

Local renal graft irradiation in children.

Between 1974-1979, 64 renal cadaveric transplants were performed in 54 pediatric recipients at our institution. Forty eight of these 64 transplants experienced at least one episode of acute rejection. These patients were divided in two equal groups including 24 transplants in 21 recipients, one group treated with chemical immunosuppression alone, the other group treated by chemical immunosuppression and radiotherapy. Kidney survival at 2 years was 54.1% (13/24) in the control group treated by chemical immunosuppression alone. In the group treated by radiotherapy and immunosuppression, kidney survival after 2 years gave a success rate of 45.8% (11/24). Thus, it would appear that addition of radiotherapy to standard immunosuppressive treatment exerted no beneficial long term effect in acutely rejected renal transplants. In view of the disappointing results obtained with radiotherapy, it is felt that this mode of treatment should be restricted to use in particular circumstances as a temporary means of immunosuppression where systemic immunosuppression is hazardous.

Adolescent↗