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Biomedical subjects

S R Dunn

Publications and source records attributed to S R Dunn.

28 records · Page 2Linked to original sources
PubMed1984

Analysis for and intestinal metabolism of precursor nitroso compounds in normal subjects and in patients with chronic renal failure.

We have demonstrated that patients with chronic renal failure generate increased amounts of both dimethylamine and N-nitrosodimethylamine in the small bowel in association with aerobic and anaerobic bacterial overgrowth. The significance of these findings in relation to the reported increased incidence of cancer in patients with chronic renal failure has not yet been defined.

Chromatography, Gas↗
PubMed1983

Generation of dimethylnitrosamine in water purification systems. Detection in human blood samples during hemodialysis.

Dimethylnitrosamine (DMNA), a carcinogen, was detected at levels up to 32 micrograms/L in dialysate from five of 16 dialysis units surveyed. Blood drawn from patients at one of these units in which DMNA was raised in the dialysate showed a significant increase in the amount of DMNA in the patient's blood when predialysis levels were compared with 15-minute intradialysis levels. The presence of a mixed-bed deionizer without an antecedent carbon filter appeared to be necessary for DMNA production. These data suggest that DMNA is generated in certain water purification systems and may then diffuse into the patient's blood. Guidelines for deionizer-treated water should be revised to include an activated carbon filter.

Adolescent↗
PubMed1983

Evidence for generation of the precarcinogen nitrosodimethylamine in the small intestine in chronic renal failure.

We have previously reported raised concentrations of dimethylamine and also bacterial overgrowth in the small intestine in CRF. Evidence for in vivo NDMA formation in the same site in CRF is now presented. Gastroduodenal intubation was performed in 9 healthy volunteers and 7 patients with advanced chronic renal failure. Blood, gastric, and duodenal aspirates were analyzed for NDMA. NDMA levels in control and CRF patients for blood were normal, but for gastric aspirate they were 67 +/- 13 and 312 +/- 68 (P less than 0.001) and for duodenal aspirate they were 70 +/- 21 and 319 +/- 47 (P less than 0.001), respectively. The results of bacterial cultures confirmed small intestinal bacterial overgrowth. We thus demonstrated statistically significant differences between NDMA concentrations in the control subjects and patients for both gastric and duodenal aspirates. This suggests that there is increased intestinal generation of NDMA in uremia. The presence of this precarcinogen may be linked with the reported increase in the incidence of cancer in CRF.

Bacteria↗
PubMed1975

Emphysematous pyelonephritis: report of 3 cases treated by nephrectomy.

Three cases of emphysematous pyelonephritis are presented. All 3 patients were diabetics, they all had Escherichia coli and there was evidence of ureteral obstruction in 1 case only. All 3 patients underwent nephrectomy and survived. Initial evaluation should be performed to rule out ureteral obstruction. Treatment should consist of a brief trial of high dose antibiotic therapy with serious consideration of nephrectomy in the face of persistent symptoms or gas. Incision and drainage are reserved for poor surgical risk patients. All patients should remain on antibacterial therapy and have frequent followup examinations.

Abscess↗