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Biomedical subjects

B Brodsky

Publications and source records attributed to B Brodsky.

78 records · Page 5Linked to original sources

High-performance liquid chromatographic assay of chloramphenicol in serum.

A new method for the analysis of serum chloramphenicol by reversed-phase, high-performance liquid chromatography (HPLC) is described. The method involves a preliminary extraction of 0.1 ml of serum with ethyl acetate containing an internal standard, chromatography with a reversed-phase C18 microparticulate column with an acetonitrile-acetate buffer mobile phase, and detection by measuring UV absorbance at 270 nm. Assay performance was compared with an existing microbiological assay. The HPLC method demonstrated both increased precision and increased sensitivity. The specificity of the HPLC method was also evaluated. The new method presents an alternative approach to the analysis of clinical specimens.

Chloramphenicol↗

Comparison of homogeneous enzyme immunoassay and high-pressure liquid chromatography for the determination of theophylline concentration in serum.

A comparison of the new homogeneous enzyme-multiplied immunoassay technique (EMIT, Syva) with a high-pressure liquid chromatographic technique for the determination of theophylline concentration is presented. The accuracy, precision, and specificity of the methods were compared. In addition, 100 samples from 61 pediatric patients receiving theophylline were assayed by both methods. The accuracy, precision, and specificity of the enzyme immunoassay support the use of this method for the quantification of theophylline concentration in clinical specimens. A significant correlation (R = 0.981, P less than 0.001) was found between results generated by enzyme immunoassay and high-pressure liquid chromatography for patient samples. The regression line relating these results had an intercept of 0.22 microgram per ml, a slope of 1.05, and a standard error of the estimate of 1.36 microgram per ml.

Caffeine↗

Dioxin exposure and public health in Chapaevsk, Russia.

One of the largest environmental polluters in Chapaevsk (Samara Region, Russia) is the Middle Volga chemical plant. From 1967 to 1987, it produced hexachlorocyclohexane (lindane) and its derivatives. Currently, it produces crop protection chemicals (liquid chlorine acids, methyl chloroform, vinyl chloride, and some other chemicals). Dioxins were detected in air (0.116 pg/m3), in soil (8.9-298 ng/kg), in the town's drinking water (28.4-74.1 pg/liter), and in the cow's milk (the content of 2,3,7,8-TCDD was 17.32 pg TEQ/g fat). The mean content of dioxins in seven pooled samples of human milk (40 individual trials) was 42.26 pg TEQ/g fat, in four female workers' blood samples -412.4 pg TEQ/g fat, in six residents blood samples (those who lived 1-3 km from the chemical plant) -75.2 pg TEQ/g fat, in four residents' blood samples (5-8 km from the plant) -24.5 pg TEQ/g fat. To assess cancer risk and reproductive health status, official medical statistical information was used. In general, the male cancer mortality observed rate in Chapaevsk is higher than expected. The SMR is higher for lung cancer 3.1(C.I. 2.6-3.8), urinary organs 2.6(C.I. 1.7-3.6). Chapaevsk women have a higher risk overall due to breast cancer 2.1(C.I. 1.6-2.7) and cervix cancer 1.8(C.I. 1.0-3.1). The incidence rates were higher for lung cancer in males and for female breast cancer in all age groups compared to Russia and Samara Region in 1998. Significant disruptions in reproductive function were detected. The mean frequency of spontaneous abortions in the last seven years was statistically higher 24.4% in Chapaevsk (compared to other of the towns region). The average rate of premature labor was 45.7 per 1000 women in Chapaevsk that is significantly higher than in most Samara Region towns. The frequency of newborns with low birth weight was 7.4%. In Russia and in most of the Samara Region towns, this rate is lower (6.2-5.1%) but not statistically different. For the determination of congenital morphogenetic conditions (CMGC), 369 children born between 1990 and 1995 were examined. The average number of CMGC per child was significantly higher, 4.5 for boys and 4.4 for girls. The first results indicated serious disruptions associated with high dioxin levels in human milk and blood in Chapaevsk. We suggest that Chapaevsk is an incredibly interesting site for further environmental-epidemiological research to assess the impact of dioxins on human health.

Adult↗

Release of amino acids, fluorescamine-reactive substances and substance P from the epidermis of the living animal.

The present study demonstrates a procedure for extraction and determination of stratum corneum amines in the living animal. A nonleaky well, containing 10 mM Tris-HCl buffer, pH 7.0, was constructed on the shaved backs of anesthetized animals. It was found that Ser, Ala, Gly and Pro are mainly released from the stratum corneum of 4-month-old guinea pigs, and in 2-month-old rats, Gly, Ser and Arg show the highest degree of release. Much lower amino acid concentrations were observed in 20-month-old rats. This was also reflected by the high levels of fluorescamine-reactive substances released from young rat skin as compared to the old animals. The release of the neuropeptide substance P into the aqueous medium was increased 3.2 times upon heat stimulus as compared to control skin. Amines and other compounds released from the skin may serve as markers for skin aging or for certain skin disorders, leading to a new approach for their treatments.

Aging↗