PubMed Health⌕ Search

Biomedical subjects

R Chandrasekar

Publications and source records attributed to R Chandrasekar.

12 recordsLinked to original sources

Fresh water fishes as indicators of Kaveri River pollution.

The survey of fish fauna in Kaveri River at polluted and unpolluted sites revealed a direct effect on the distribution of fishes in that 14 species were observed in unpolluted site and only 6 species in polluted site. Further, the haemotological parameters like RBC, WBC and haemoglobin content increased in fishes collected from polluted site whereas the organic constituents of muscle decreased in the above fishes when compared to the fishes of unpolluted site. The reason for the above changes is discussed.

Animals↗

Separation of xylidine isomers by micellar electrokinetic chromatography.

Xylidines are important precursors for the production of dyes, drugs, and various other products. Because of the high carcinogenic nature of some xylidine isomers it becomes very essential and relevant to develop suitable analytical procedures to separate isomers as well as enhance detection at very low concentrations. Micellar electrokinetic chromatography has been standardized at various influencing parameters such as pH, ionic strength, and micelle modifiers, and the optimum conditions have been ascertained for the best separation and sensitivity of standard mixtures. The applicability of the procedure in environmental samples is studied.

Journal Article↗

Upper limb venous gangrene, a lethal condition.

Venous gangrene of the upper extremity is rare. It was the mode of presentation in a 41-year-old woman who died 10 days later of heart failure due to acute myocardial infarction. There is evidence from this and previous publications that patients with this condition tend to have characteristics in common. Most have either advanced malignant disease or seriously impaired myocardial function and venous gangrene usually occurs as a pre-terminal event. Treatment should be directed primarily at the underlying illness but there may be a case for early amputation if permitted by the general condition of the patient.

Adult↗

Intra-arterial injection of temazepam in drug abusers.

The effects of intra-arterial injection of Temazepam are described in 11 drug abusers admitted over a 6 month period. All patients suffered severe ischaemia, and injection into the radial artery invariably resulted in tissue loss leading to amputation. The pathogenesis and options for treatment are discussed.

Adult↗

The methoxatin semiquinone: a pulse radiolysis study.

Methoxatin is a novel o-quinone found in bacterial dehydrogenases and mammalian plasma amine oxidase. This is the first report of the redox potential and spectrum of the 1-electron reduced methoxatin semiquinone obtained by the method of pulse radiolysis in aqueous solution.

Kinetics↗

Methylamine dehydrogenase and cytochrome c552 from the bacterium W3A1.

We describe a two-step purification of the methoxatin-containing enzyme methylamine dehydrogenase from crude extracts of the bacterium W3A1, and a longer purification of cytochrome c552 from the same organism. Some of the kinetic properties of the dehydrogenase are presented, together with the demonstration that c552 is an electron acceptor for this enzyme. Cytochrome c552 is the only hemeprotein we observed in the visible spectrum of intact W3A1 cells that were grown under the same culture conditions used for the protein purifications. Addition of methylamine to whole cells causes an increase in the rate of O2 uptake together with an abrupt reduction of c552. We propose that, in vivo, the electrons from the amine reach the hemeprotein through the dehydrogenase.

Bacteria↗

Determination of crude fat in meat by supercritical fluid extraction: direct method: PVM 3:2000.

Meat samples are prepared by passing meat through a food chopper, bowl cutter, or food processor, subsampling the meat, and mixing the meat with granular diatomaceous earth. No drying step is necessary. Supercritical CO2 is then used to extract crude fat (which is defined as the components of meat that are extractable with petroleum ether, without digestion of the sample). Extracted material is deposited on glass wool contained in collection vials. After removal of any residual moisture from the extracts, percent crude fat is determined by weight gain of the collection vial. This method has been peer-verified by 3 laboratories, for a wide variety of raw and processed meat products containing 6-28% crude fat. Samples were prepared at the submitting laboratory. Ground samples were split into 4 portions, packed in Whirlpack bags, and immediately frozen. Frozen samples were sent by overnight room temperature, and percent fat was determined (in triplicate), without further processing of the samples. Analysis of the samples was completed within 1 week of sample prepara. tion. On the basis of this study, it can be estimated that all repeatability and reproducibility values are <3.0. Mean accuracy of the direct gravimetric supercritical fluid extraction method for meat samples ranged from +0.22 to -1.41 when the method was compared with AOAC Method 960.39. Interferences are unlikely but would include any nonfat substance that is added to (processed) meat, is soluble in nonpolar solvents, and is present in a quantity that would alter results. This method is expected to perform equally well for all meats with fat content within the stated range of applicability.

Animals↗