Biomedical subjects
R S Barsoum
Publications and source records attributed to R S Barsoum.
Use of the low-dose desferrioxamine test to diagnose and differentiate between patients with aluminium-related bone disease, increased risk for aluminium toxicity, or aluminium overload.
BACKGROUND: Aiming at a safe method in the diagnosis of aluminium-related bone disease (ARBD)/aluminium overload the low-dose desferrioxamine (DFO) test was developed. In a multicentre study histological and histochemical data and aluminium bulk analysis of bone biopsies of 77 dialysis patients were correlated with the results of both the 5 mg/kg and 10 mg/kg DFO tests. METHODS: ARBD was considered to be present when > 15% of the bone surface was positively stained for aluminium and the bone formation rate was below 220 microns 2/mm2/day. Patients in which the Aluminon staining was positive (> 0%) were considered at an increased risk for aluminium toxicity independent of the type of renal osteodystrophy. Patients were considered aluminium overloaded when the bone aluminium content was > 15 micrograms/g wet weight and/or the Aluminon staining was positive (> 0%). RESULTS: Using the proposed criteria 15 patients were found to have ARBD; 13 of them presenting with a serum iPTH below 150 ng/l. In conjunction with an iPTH measurement the DFO test had a more than acceptable sensitivity and specificity in the diagnosis of ARBD. The test was considered positive when a post-DFO serum aluminium increment (delta sA1) above 50 micrograms/l (5 mg/kg) or 70 micrograms/l (10 mg/kg) together with a serum iPTH below 150 ng/l was found. Using these cut-off levels the 5 and 10 mg/kg tests in the diagnosis of ARBD had a sensitivity of 87% and a specificity of 95% and 92% respectively whereas the predictive value for a positive test for the population under study was 80% (5 mg/kg). Not a single patient with a serum iPTH > 650 ng/l had a positive staining (> 0%) even when the bone aluminium level was elevated (> 15 micrograms/g wet weight). In the detection of patients at risk for aluminium toxicity delta sA1 thresholds of 50 micrograms/l (5 mg/kg) and 70 micrograms/l (10 mg/kg) in combination with a serum iPTH < 650 ng/l had a sensitivity of 92% and specificity of 86% and 84% respectively. In the clinical setting of aluminium overload, threshold delta sA1 levels of 50 micrograms/l (5 mg/kg) and 70 micrograms/l (10 mg/kg) had a sensitivity of 91% and a specificity of 95% and 90% respectively. CONCLUSIONS: The low-dose DFO test is a reliable test for the detection of aluminium overload; however, it is not specific enough to differentiate between ARBD, increased risk of aluminium toxicity, and aluminium overload unless it is used in combination with a serum iPTH measurement. In conjunction with a serum iPTH measurement it is an important tool in the differential diagnosis and may avoid the necessity of a bone biopsy in the majority of patients. Data obtained in the present study have allowed us to update the strategies for monitoring, diagnosis and patient follow-up proposed at the Consensus Conference on Diagnosis and Treatment of Aluminium Overload in End-Stage Renal Failure; Paris, 1992.
Schistosomal glomerulopathies.
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The Egyptian transplant experience.
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Recurrent haematuria in Schistosoma infection.
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Hepatic macrophage function in schistosomal glomerulopathy.
Hepatic fibrosis in the pathogenesis of schistosomal glomerulopathy cannot be explained by any positive influence of hepatocellular injury. In order to examine the potential role of impairment of hepatic macrophage function, the t1/2 plasma clearance of 99mTc-sulphur colloid was studied in 30 patients with schistosomal glomerulopathy, ten normal volunteers, ten cases of uncomplicated intestinal schistosomiasis, ten non-schistosomal cirrhotic patients and ten non-schistosomal nephrotic patients. Liver and renal biopsies were obtained from appropriate groups and examined by light microscopy and glomerular immunofluorescence. There was a significant correlation between t1/2 of sulphur colloid clearance and proteinuria, mesangial hypercellularity, and predominance of IgA glomerular deposits. These data indicate that hepatic macrophage dysfunction is an important factor in the pathogenesis of schistosomal glomerulopathy, and that IgA plays a major role in advanced glomerular lesions. The degree of impairment of hepatic macrophage function may influence the pattern and severity of glomerular lesions depending upon the affection of IgA clearance mechanisms.
Schistosomal glomerulopathy: selection factors.
Of several hundreds of millions of people infested with schistosomiasis, only a few hundreds have, so far, been documented to have one or other of the three schistosoma-associated immune-mediated glomerulopathies, namely proliferative glomerulonephritis, focal and segmental sclerosis, and amyloidosis. Regardless of undoubted under-reporting, some factors must be involved in the selection of those who develop such glomerulopathies. On the basis of experimental and clinical evidence, this review highlights the importance of parasitic species, associated salmonellosis, genetic predisposition and impaired hepatic macrophage activity. It also discusses the potential pathogenic role of the prevailing parasite 'strains', intensity of infestation, associated infections with hepatitis B, and common urinary pathogens and impairment of hepatocellular function. Selection ultimately seems to be multifactorial, but there is evidence that inefficiency of the hepatic macrophage system plays a key role by allowing both schistosomal antigens and IgA polymers to escape hepatic clearance and/or modulation.
Successful renal transplantation in a presensitized recipient after multiple blood transfusions.
A presensitized uremic patient, initially considered unfit for transplantation, lost his cytotoxic antibodies during prospective multiple transfusion therapy. He subsequently received a graft from his brother, despite a previously positive crossmatch. Hyperacute rejection did not take place. A mild acute rejection episode on the fourth day readily responded to pulse doses of prednisolone. Graft function is excellent at one month. The possible value of intraoperative blood transfusion is discussed.
Acute renal failure in the 1973 Middle East war--experience of a specialized base hospital: effect of the site of injury.
All battle casualties admitted to a specialized base hospital were surveyed for early signs of acute renal failure (ARF), and diuresis was induced in high-risk subjects. Sixty of 1.147 cases developed ARF. Statistical analysis showed that ARF was more frequently observed with multiple injuries, as well as with single injuries of the abdomen, proximal lower limb, and the head and cervical spine. These were therefore considered as critical sites of injury. The relation of urine output, incidence of septic complications, and mortality rate to the site(s) and multiplicity of trauma is discussed, along with the probable mechanism(s) of ARF following each of the critical injuries.
Renal amyloidosis and schistosomiasis.
A retrospective study of 60 renal biopsies obtained from nephrotic subjects with schistosomiasis showed amyloid deposits in 10 cases. Distribution was usually segmental, mainly mesangial and overlapped with the conventional mesangio-proliferative lesions of schistosomiasis. The invariable clinical presentation was proteinuria with generalized oedema of insidious onset and a slowly progressive or intermittent course. Differences from conventional schistosomal nephropathy are described. Response to anti-schistosomal treatment was very poor. Repeat renal biopsies showed no regression of the lesions. The possible links between schistosomiasis and amyloidosis are discussed and causes of amyloid deposition suggested.
Amyloidosis in hepatosplenic schistosomiasis.
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Renal disease in hepatosplenic schistosomiasis: a clinicopathological study.
Thirty-nine cases of hepatosplenic schistosomiasis associated with renal disease are included. They were investigated for renal function, serum and urinary immunoglobulins, some serological tests, and bacteriological studies for evidence of associated salmonellosis. Renal biopsy was obtained from 23 subjects and studied by light microscopy. It was possible to distinguish two groups of cases "salmonella-negative" and "salmonella-positive". The former group was characterized by marked glomerular lesions, mainly membrano-proliferative, in different phases of evolution. Salmonella-positive cases were categorized into those with clinical, laboratory and histological evidence of interstitial nephropathy (six cases), that seems to result from salmonella pyelonephritis; and those with overt glomerular lesions (17 cases). The latter group differed from salmonella-negative cases in having mainly proliferative glomerular lesions with minimal or no basement membrane thickening; the lesions were diffuse and appeared in the same stage of evolution. The possible relation of schistosomiasis and associated salmonellosis to the pathogenesis of these lesions is discussed, suggesting an immunological basis for the glomerular injury and outlining the possible significance of hepatic fibrosis.
On the mechanism of cell-mediated immunodeficiency in chronic renal failure.
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Plasma immunoreactive insulin (IRI) and glucose tolerance in bilharzial hepatic fibrosis.
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Renal biopsy in Schistosoma-Salmonella associated nephrotic syndrome.
Percutaneous needle biopsy of the kidney on eight nephrotic patients with Schistosoma mansoni and chronic Salmonella paratyphi A infection showed diffuse proliferative glomerular change in all biopsies. Capillary basement membrane was normal. Diffuse granular deposits were detected in the glomerular mesangial cells by direct staining with fluorescein labelled anti-IgG anti-IgM. No fluorescence was obtained with rabbit anti-Salmonella paratyphi A. After treatment with ampicillin and niridazole, a reduction of cellular proliferation and mesangial matrix expansion was observed. Simultaneously following treatment there occurred a dramatic clinical improvement with cessation of proteinuria and a return of plasma protein levels and serum complement (C3) to normal values.
The ileocecal bladder: a new method for urinary diversion after radical cystectomy (a preliminary report).
Ten patients underwent radical cystectomy and ileocecal bladder reconstruction for carcinoma of the bladder. The ileocecal region was used as an artificial bladder, its valve protecting the kidneys from back pressure exerted by the external urethral sphincter. The ureters were anastomosed to the ileal part and the cecum was anastomosed to the prostatic urethra in 7 men and to the bladder neck in 2 women and 1 man. Two patients died postoperatively. All patients had perfect control of micturition during the day. Those in whom the bladder neck was preserved were also fully continent at night. The remaining patients had a minor degree of nocturnal enuresis with only a few drops of urine voided involuntarily during sleep. All patients feel the desire to void when the bladder is full. Voiding cystograms in all patients did not reveal reflux in the ureters. IVP's done up to 11 months postoperatively showed preservation and improvement of kidney function and configuration. Followup cystometric studies and serum electrolyte determinations are under investigation.