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Biomedical subjects

M A Koyle

Publications and source records attributed to M A Koyle.

56 records · Page 4Linked to original sources

Evaluation of the utility of indium-111 oxine platelet imaging in renal transplant patients on cyclosporine.

Twenty five In-111 oxine platelet imaging procedures were performed in 21 renal transplant patients to assess the value of this study for diagnosis of renal transplant rejection in recipients receiving cyclosporine (CYS) for immunosuppression. Fourteen biopsies were performed, and an extensive, in-depth review of the clinical progress of each patient was obtained. There was no ideal "gold standard" to which our imaging results could be compared, but we used a combination of biopsy findings, clinical impressions, and changes in renal function after pulsing with steroids and/or decreasing CYS dosage as the basis for our diagnoses. We were unable to distinguish between renal rejection and CYS toxicity using platelet imaging. The sensitivity of the platelet procedure for diagnosing rejection or CYS toxicity was 100%. The specificity for rejection or CYS toxicity was only 76.5%. In view of the inability of this test to distinguish between rejection and CYS toxicity, its rather low specificity, and its relatively high cost, it is not a particularly helpful study for the diagnosis of renal transplant rejection in patients on CYS.

Blood Platelets↗

Immunohistochemical distribution of renal prostaglandin endoperoxide synthase and prostacyclin synthase: diminished endoperoxide synthase in the hepatorenal syndrome.

To evaluate possible causes of the diminished prostaglandin production in advanced hepatorenal syndrome, prostaglandin endoperoxide synthase and prostacyclin synthase were localized and semiquantitated by immunofluorescence in postmortem, biopsy and nephrectomy renal tissues. In normal kidneys, antiprostacyclin synthase serum caused intense staining in peritubular capillaries, in the adjacent renal interstitial cells and in glomerular mesangial regions. Antiprostaglandin endoperoxide synthase serum caused staining of collecting duct epithelial cells, cells of the thin ascending limb and possibly glomerular mesangial cells. Prostacyclin synthase-positive staining was graded 5+ (scale of 0+ to 5+) in all kidney samples. Medullary collecting tubule prostaglandin endoperoxide synthase-positive staining was graded 4+ or 5+ in kidney samples from patients with acute tubular necrosis or acute tubulointerstitial nephritis and from patients with liver failure without the hepatorenal syndrome. However, prostaglandin endoperoxide synthase-positive staining was markedly diminished or absent (average 1+) in patients with the hepatorenal syndrome. These data suggest that loss of the medullary prostaglandin endoperoxide synthase is the cause of diminished urinary prostaglandin E2 excretion in the hepatorenal syndrome.

Adult↗