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Biomedical subjects

B Owens

Publications and source records attributed to B Owens.

27 records · Page 2Linked to original sources
PubMed1989

Acute and chronic renal effects of radiocontrast in diabetic rats. Role of anesthesia and risk factors.

The acute and chronic renal effects of the intravenous injection of meglumine diatrizoate sodium 76% (CM), 5 mL/kg body weight were studied in diabetic (DM) and age-matched normal (C) female Sprague-Dawley rats. In acute studies, the effect of anesthesia was assessed for 2 hours. Although anesthesia decreased 14C-inulin clearance (Cin) in both DM and C rats (P less than .001 vs. conscious values), there was no impairment of Cin in either group after administration of CM. In chronic studies, creatinine clearance (Ccr) was followed for 3-4 days after CM administration. Four protocols to assess risk factors in DM and C were used: adult rats with normal hydration (2A); old dehydrated rats with DM of long duration (2B); rats with prior decreased Ccr (remnant kidney, 2C); and DM rats treated with insulin (2D). No clear-cut nephrotoxicity was apparent in these studies, except that proteinuria increased with CM in Study 2C. A greater severity of renal dysfunction, renal disease, or the association of multiple risk factors may be necessary to induce CM-related nephrotoxicity in the experimental animal. The rat, diabetic or not, may have an inherent resistance to CM-induced renal injury.

Aging↗
PubMed1982

Impaired glucagon-stimulated glucose output in livers of acutely uremic rats.

The role of glucagon in the pathogenesis of abnormalities of glucose metabolism associated with renal failure remains undefined. We have evaluated glucagon-stimulated glucose and cyclic AMP output and amino acid uptake in isolated perfused livers of rats with experimentally-induced ARF and sham-operated controls. ARF animals exhibited azotemia, hyperglycemia, hyperinsulinemia, and hyperglucagonemia. During stimulation with physiologic (3 X 10-10M) or supraphysiologic (3 X 10-8M) glucagon concentrations, glucose output was lower in livers of ARF rats than in those of controls, whereas cyclic AMP responses were similar or exceeded those of controls. Hepatic glycogen content was lower in rats with ARF and the stores were exhausted at the end of perfusions. Additional studies in livers of fasted animals revealed no significant differences in glucose output or amino acid uptake between ARF and control livers perfused with physiologic levels of glucagon. These experiments suggest that the decreased glucagon-stimulated glucose output in isolated perfused livers in acutely uremic rats is due primarily to glycogen depletion rather than to impaired gluconeogenesis. Normal or increased cyclic AMP responses to glucagon suggests intactness of the hormone receptor-adenylate cyclase.

Amino Acids↗
PubMed1980

Urea synthesis by perfused rat liver in experimental uremia.

Urea synthesis was examined in experimental uremia using the isolated perfused rat liver in order to assure strict control of substrate (NH4Cl) presented to the liver. Acute uremia was created in female Sprague-Dawley rats by bilateral nephrectomy (n = 7) 48 h prior to studies. Chronic uremia (8--14 weeks) was produced by right nephrectomy and segmental infarction of the left kidney in 7 rats. At infusion rates of NH4Cl (8.3 mumol/min) which resulted in prehepatic perfusate ammonia levels approximately twice the previously described Km value, livers of chronically uremic rats had slightly higher rates of urea production than controls (controls: 0.41 +/- 0.03; chronic uremia: 0.54 +/- 0.04 mumol/min/g of wet liver weight; p less than 0.02). In acute uremia, urea production was higher (0.66 +/- 0.05 mumol/min/g) than in sham-operated rats (0.59 +/- 0.05 mumol/min/g) but the differences did not achieve statistical significance. Simultaneously performed taurocholate transport studies did not reveal significant functional differences between the livers of uremic and control animals. The data suggest that urea production by livers of uremic rats is increased when compared to that of control animals.

Acute Disease↗
PubMed1979

Techniques for laparoscopy on patients with previous abdominal surgery.

Many clinicans are hesitant to perform laparoscopy on patients with previous intra-abdominal surgery, because of increased risk of hemorrhage or intestinal perforation in the presence of abdominal adhesions. Experiences and techniques used in Grady Memorial Hospital to increase the safety of laparoscopic procedures performed on patients with extensive abdominal adhesions are discussed.

Female↗
PubMed1977

Effect of acute uremia on arginine metabolism and urea and guanidino acid production by perfused rat liver.

Since arginine is a precursor of urea and other guanidino derivatives, we have evaluated its metabolism in acute uremia using the isolated perfused rat liver. Female Sprague-Dawley rats underwent bilateral nephrectomy (n = 5) or sham operation (n = 5) 48 h prior to liver perfusion. Fifty microCi of L-[guanidino 14C] arginine and unlabelled arginine and aspartic acid were added to the recycling perfusate 15 min prior to liver perfusion. Perfusate concentrations of urea and other guanidino derivatives were measured with high-pressure liquid chromatography. After the initial 30 min of perfusion, net uptake of arginine was lower, and net release of guanidino-succinic acid (GSA) was higher in the livers of acutely uremic rats. Net release of urea was also higher in uremia but the results did not achieve statistical significance. In uremia, the percent conversion of 14C arginine to 14C urea was significantly higher (79 +/- 5 [SE]%) than in controls (58 +/- 7%). These results demonstrate increased GSA production by livers of acutely uremic rats and suggest that acute uremia may be associated with increased arginine utilization and increased production of urea.

Acute Kidney Injury↗
PubMedDate not supplied

Clinical and economic outcomes of infants receiving breast milk in the NICU.

ISSUES AND PURPOSE: This study compared clinical and economic outcomes for infants who were exclusively fed breast milk and infants who were fed commercial formula. DESIGN AND METHODS: A retrospective medical record review from a regional neonatal intensive care unit (N = 80) using consultation logs from the lactation coordinator and a matched sample of formula-fed infants. RESULTS: Neither clinical (weight gain, length of stay, days of parenteral nutrition) nor economic outcomes (direct variable costs, net revenue) differed significantly between the groups. PRACTICE IMPLICATIONS: While it may not be possible to demonstrate sufficient cost savings while the infant resides within the NICU to justify a lactation coordinator, long-term clinical and economic outcomes may be sensitive to this specialized nursing service.

Cost Savings↗