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Biomedical subjects

G P Butrimovitz

Publications and source records attributed to G P Butrimovitz.

8 recordsLinked to original sources
PubMed1983

Extremely low seminal lead concentrations and male fertility.

Seminal lead concentrations in normal and vasectomized males with no history of lead exposure were measured by flameless atomic absorption spectrophotometry. Extremely low concentrations of 3.8 micrograms/dl were found in normal males versus 4.1 micrograms/dl in vasectomized males. No significant correlation between lead and sperm count or sperm motility existed. It is suggested that the major contribution of lead in human semen is from the prostate and/or seminal vesicles and that very low lead levels may not have measurable effect on fertility indices.

Adult↗
PubMed1983

Micromethod for determination of lactate dehydrogenase isoenzyme C4 activity in human seminal plasma.

We have developed an automated enzymatic assay for LDH-C4, a lactate dehydrogenase (EC 1.1.1.27) isoenzyme found exclusively in spermatozoa, as a marker of human spermatogenesis. LDH-C4 activity is assayed bichromatically in the Abbott ABA-100 spectrophotometer, with 2-oxohexanoate as substrate. As many as 27 samples (2.5 microL) of human seminal plasma can be analyzed sequentially, with apparent zero-order kinetic conditions and with a precision (CV) of 5%. The apparent Km for the 2-oxohexanoate reaction is 11.2 mmol/L. Electrophoretic and enzymatic studies indicate that LDH-C4 acts on this substrate to produce hydroxyhexanoate, in contrast to lactate dehydrogenase isoenzymes 1 and 5--further evidence for the uniqueness of LDH-C4. The sensitivity, specificity, and speed of this assay system makes it practicable for studies on, and evaluation of, male fertility.

Caproates↗
PubMed1982

Interactions among enzyme, antibody, drug, and time in enzyme immunoassays for drugs of abuse.

Published information on the major interactive variables of enzymic immunoassays for drugs, whether in urine or serum, is scanty. Using the Syva EMIT-dau Barbiturates assay as an example, we examined the following interactive variables with respect to test response: concentrations of enzyme, antibody, and drug; urine matrix; and time. The results suggest a process for optimizing this type of enzyme immunoassay. Transformation of the data gives indirect evidence of heterogeneous antibody reactions that are drug-concentration dependent.

Antibodies↗
PubMed1979

Resolution of age-dependent reference intervals: polynomial regression methodology with applicability to plasma zinc levels in a childhood population.

We present a systematic parametric method for resolving age-related reference intervals based on differential-polynomial regression analysis. Application of this method to plasma zinc concentrations in a childhood population results in a third degree polynomial expression from which two statistically independent age-reference intervals are derived. The method appears to be useful in describing age-dependent concentration trends particularly for pediatric and geriatric populations.

Adolescent↗
PubMed1979

An improved micromethod for theophylline determination by reversed-phase liquid chromatography.

We describe an improved micro-scale method for determining serum theophylline by reversed-phase liquid chromatography. Samples are deproteinized with two volumes of methanol containing beta-hydroxyethyltheophylline as an internal standard. The supernate is chromatographed with a methanol/sodium acetate buffer (15/85 by vol) mobile phase, and the amount of theophylline is calculated from the ratio between peak heights for theophylline and the internal standard at 273 nm. We also monitor for chemical interferences at 254 nm. We found no interferences from ampicillin, methicillin, cephalosporin, and cephalothin. None of the drugs tested or metabolites and compounds related to theophylline have been found to interfere. The method is rapid, accurate, sensitive, and specific for theophylline.

Chromatography, High Pressure Liquid↗
PubMed1978

Zinc nutrition and growth in a childhood population.

Plasma zinc concentrations are a useful indicator of the zinc nutritional status in humans. This study was designed to evaluate plasma zinc levels in a population stressed by a low-income diet and rapid growth. Plasma zinc concentrations of an inner city childhood population are analyzed by polynominal regression analysis. The resultant age-related plasma zinc curves for male and female subjects are markedly different. Concentrations are lowest during the years of rapid growth, infancy and puberty. The growth velocities (growth indices) of these two populations are calculated and mirror the variation of plasma zinc concentrations. The data suggest that lowered plasma zinc concentrations result from inadequate zinc nutrition during periods of rapid growth.

Adolescent↗