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Biomedical subjects

F H Lee

Publications and source records attributed to F H Lee.

28 records · Page 2Linked to original sources
PubMed1978

High-performance liquid chromatographic determination of plasma and urinary 1-ethyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3,7-dicarboxylic acid.

A high-performance liquid chromatographic method for the analysis of 1-ethyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3,7-dicarboxylic acid (I) in plasma and urine is described. A statistical evaluation of the assay technique has shown acceptable accuracy and precision at concentrations as high as 2.0 microgram/ml of plasma or 29.0 microgram/ml of urine for samples augmented with 1. As little as 0.08 microgram/ml of I in plasma or 0.42 microgram/ml of I in urine were quantitatively determined. The mean relative error for the assay of unknown concentrations of I in plasma and urine was +/- 8% and +/- 3%, respectively. This method was used for the analysis of I in the plasma and urine of rhesus monkeys following oral administration of 200 mg/kg of nalidixic acid.

Animals↗
PubMed1978

Perfluorooctyl bromide concentration in plasma and tissues of beagle dogs.

Plasma levels were determined frequently after single doses of perfluorooctyl bromide were administered to beagle dogs at doses of either 30.8 g/kg po or 3.9 g/kg intratracheally. The apparent first-order half-life during the terminal elimination phase was about 1 day after oral medication and about 7 days after intratracheal administration. Analysis of tissues revealed the highest concentrations of the compound in abdominal fat of dogs autopsied 4 weeks later.

Animals↗
PubMed1975

Determination of dicumarol metabolites in bile of rats.

After intravenous administration of dicumarol-14C to rats, the bile excreted over the next 24 hr contained from 32 to 46% of the administered radioactivity. At least three primary metabolites and a small amount of unchanged dicumarol were present in the bile. Over 91% of the primary metabolites was converted to dicumarol and 7-hydroxydicumarol by hydrolysis with beta-glucuronidase. Some primary metabolites were hydrolyzed simply by acidification to pH 3 or by treatment under the acidic conditions utilized in the enzymatic hydrolysis. The three primary metabolites contain carboxylic acid groups, as indicated by their electrophoretic mobility-pH profiles, and some are simple glucuronides of dicumarol and 7-hydroxydicumarol. The possibility that others are derivatives of these compounds in which a coumarin lactone ring is opened cannot be ruled out. When the metabolites released by either acidification or enzymatic hydrolysis were chromatographed in n-butanol-3 M ammonia, artifacts were produced, presumably as a result of decomposition of 7-hydroxydicumarol. The question is raised whether a previously reported metabolite (B055) is an artifact.

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PubMed1966

Dual care.

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England↗
PubMedDate not supplied

Soy fiber delays disease onset and prolongs survival in experimental Clostridium difficile ileocecitis.

Clostridium difficile colitis is a disabling complication in critically ill patients who commonly receive broad-spectrum antibiotics and liquid diets. To date, there is no experimental model specifically designed to investigate the effects of liquid diets on this type of colitis. The addition of fiber to liquid diets normalizes gut structure and improves absorptive function in selected conditions of intestinal dysfunction. The purposes of this study were the following: (1) to develop a reproducible model to examine the interaction of acute C difficile-induced colitis and liquid diets, (2) to determine whether the addition of soy fiber to a liquid diet improves disease, and (3) to investigate possible mechanisms of fiber-mediated disease improvement. Syrian hamsters were pair-fed with either a polymeric liquid diet or the same diet with 1.4% soy fiber for 10 days. Animals were given either clindamycin and C difficile (to produce ileocecitis), or equivalent volumes of saline. Mean survival time and systematic stool examinations for C difficile toxin positivity, liquidity, and percent water were performed to determine the effect of soy fiber on disease. Survival time was prolonged by 34% (p < .05), and C difficile toxin positivity and stool liquidity were significantly reduced (p < .05) with fiber. Additional animals were studied to determine possible mechanisms for improved survival in fiber-supplemented animals. Cecal histology, colonic water absorption, cecal microflora, and gastric to anus transit time were measured in these animals. Colonic water absorption and gastric to anus transit time were significantly increased (p < .05) and decreased (p < .05) with fiber, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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