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Biomedical subjects

K R Murthy

Publications and source records attributed to K R Murthy.

33 records · Page 2Linked to original sources
PubMed1987

Polycyclic aromatic hydrocarbons in C8 isomer aromatic feed: analysis by GC, GC/MS, and GC/FTIR techniques.

Polycyclic aromatic hydrocarbons (PAHs), apart from their carcinogenic and mutagenic nature, create many problems in the petrochemical industry due to their tendency toward carbonization. Compounds in C8 aromatic isomer feed are analyzed by means of sample concentration, followed by separation of individual compounds by gas chromatography on a stainless steel OV-101 phase capillary column and identification by gas chromatography/mass spectrometry and gas chromatography/Fourier transform infrared spectroscopy. Various compounds belonging to different classes (mainly monocyclic, dicyclic, and tricyclic aromatics), oxygenated aromatics, and aliphatic saturates are quantified in the concentrated hydrocarbon residue of C8 isomer feed. Both unsubstituted and alkyl substituted ring type compounds are present. Concentrations obtained for PAH compounds in the C8 isomer feed range from 0.2 to 0.42 micrograms/mL.

Chromatography, Gas↗
PubMedDate not supplied

Peroxidase: a novel pathway for chemical oxidation in human term placenta.

Hydrogen peroxide-dependent oxidation of xenobiotics in a crude fraction of human term placental membranes (nuclei, mitochondria and microsomes) was investigated. Guaiacol was employed as a model substrate. The rate of its oxidation was found to be dependent on the concentration of protein, H2O2 and the substrate as well as the pH of the buffer. Several other classical substrates for peroxidases from different sources viz. pyrogallol, benzidine, p-PDA, DMBD, ABTS, TMPD and TMBD and endogenous chemicals such as bilirubin and epinephrine were also found to undergo oxidation. The xenobiotic oxidizing capacity of the membranes was retained by CaCl2 (0.5 M) extract as well as by the partially purified enzyme obtained by affinity (Con A) chromatography. The H2O2-dependent chemical oxidation by the partially purified peroxidase was inhibited by NaN3 and KCN (IC50 values 41 and 23 microM respectively). These results suggest that peroxidase may be a major enzyme in human term placenta capable of oxidation of endogenous chemicals and xenobiotics.

Bilirubin↗
PubMedDate not supplied

Immunotherapy in allergic conjunctivitis.

Eighty patients with allergic conjunctivitis were treated with immunotherapy employing specific allergens. Sixty-two percent of these showed beneficial response. In cases of vernal conjunctivitis needing topical steroid preparations frequently for control of symptoms, immunotherapy is worth attempting to cause remission of symptoms.

Adolescent↗