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Biomedical subjects

S N Chatterjee

Publications and source records attributed to S N Chatterjee.

At least 73 records · Page 4Linked to original sources
PubMed1984

Peroxidation of the dried thin film of lipid by high-energy alpha particles from a cyclotron.

High-energy alpha particles produced a dose-dependent linear increase in different lipid peroxidation products (e.g., malondialdehyde (MDA), conjugated dienes, and hydroperoxides) in the dried thin film state. An inverse dose-rate effect was observed when the dose rate was varied by changing either the alpha-particle fluence rate or the alpha-particle energy. The antioxidants alpha-tocopherol and butylated hydroxytoluene (BHT) suppressed the alpha-particle-induced lipid peroxidation in the dried thin film state, and in this respect alpha-tocopherol was found superior to BHT. It was found that alpha-tocopherol was equally efficient in inhibiting lipid peroxidations by alpha particles and ultraviolet light.

Alpha Particles↗
PubMed1983

DNA damage, prophage induction and mutation by furazolidone.

Ultraviolet absorption data and thermal chromatography through hydroxyapatite (HAP) column revealed that furazolidone treatment of Vibrio cholerae cells produced more than 80% of DNA reversibly bihelical due to the formation of interstrand cross-links and the reaction obeyed a first order relation. Sensitivities of the Escherichia coli strains to the lethal action of the drug were in the order: AB 2480(uvr- rec-) greater than AB 2463(rec-) greater than AB 1886(uvr-) greater than AB 1157(repair proficient) or AB 4401(wild type). Furazolidone was 'Rec test' positive, produced dose-dependent prophage induction in E. coli cells and also dose-dependent streptomycin-resistance forward mutation in V. cholerae cells. The quantitative aspect and also the mode of furazolidone action on DNA were discussed.

DNA Repair↗
PubMed1983

Killing of bacteria during solar eclipse and its biological implications.

Enhanced killing of bacteria was obtained by radiation reaching the earth during total solar eclipse (February 16, 1980) than during the corresponding time of a normal day (February 26, 1980). The killing was not due to the formation of sunlight induced photoproducts of tryptophan. The damage to the bacteria exposed to sunlight could be repaired by photoreactivation.

Escherichia coli↗
PubMed1983

Lipid peroxidation by ultraviolet light and high energy alpha particles from a cyclotron.

High energy alpha-particles (approximately 16 MeV) and 254 nm ultraviolet light produced dose dependent linear increase of lipid hydroperoxides in the dried thin film state. For both types of radiation, an inverse dose-rate effect, i.e., a protracted radiation dose was more effective than a shorter, more intense one of larger size, was observed. Ultraviolet light (254 nm) produced higher yields of hydroperoxides in the aqueous liposomal suspension of lipid than in its dried thin film state.

Alpha Particles↗
PubMed1982

A prospective study of oropharyngeal excretion of Epstein-Barr virus in renal homograft recipients.

This prospective study was undertaken to examine the incidence of oropharyngeal excretions of Epstein-Barr virus (EBV) in the period after transplantation in human renal allograft recipients. Throat gargles from 23 recipients were tested for EBV. Five patients were already EBV excretors when the first specimens were tested. Of the remaining 18 patients 15 converted to positive within the first 7 months following transplantation. Three patients never excreted EBV in their throat gargles. This prospective study showed that 15/18 (83%) renal homograft recipients acquired active EBV infection (as indicated by excretion of EBV) after transplantation; 10/15 (66%) acquired active infection between 3-7 months after transplantation. We conclude that renal homograft recipients are highly susceptible to active EBV infection especially after the second month of transplantation.

Adult↗
PubMed1981

Radiomimetic property of furazolidone and the caffeine enhancement of its lethal action on the vibrios.

Sensitivities of the strains belonging to four vibrio biotypes to the action of furazolidone were investigated. Vibrio cholerae (classical) was most and Vibrio parahaemolyticus least sensitive to this drug. Statistical analyses revealed significant differences between any two of the four types of vibrio in respect of their sensitivity to furazolidone. The drug was radiomimetic in action, the doses of UV light (DUV) and furazolidone (Df) required for 10% survival of the vibrios being correlated by the equation, Df = 0.28 exp. (0.008 DUV). Caffeine exhibited lethal synergism with furazolidone and the synergistic effect depended on the mode of caffeine treatment, the effect being maximum when caffeine was present along with and also after furazolidone treatment. UV spectrophotometric study revealed that caffeine did not bind with native DNA but did so with denatured DNA resulting in a bathochromic shift and a quenching of the caffeine absorption maximum at 209.4 nm. The binding isotherm (Scatchard plot) indicated the presence of a heterogeneity in the binding sites and that the parameters for the strongest mode of bonding were n = 0.254 and k = 7.5 X 10(5) M-1.

Caffeine↗
PubMed1981

Ascorbic acid metabolism in diabetes mellitus.

In contrast to normal subjects diabetic patients and very low plasma ascorbic acid and significantly high (p less than 0.001) dehydroascorbic acid irrespective of age, sex, duration of the disease, type of treatment, and glycemic control. However, there was no significant difference between the mean leukocyte ascorbate concentrations of the two populations. The in vitro rates of dehydroascorbate reduction in the hemolysate and the erythrocyte reduced glutathione levels and the glucose-6-phosphate dehydrogenase activities, which regulate the dehydroascorbate reduction, were similar in normal and diabetic subjects. The turnover of ascorbic acid was higher in the diabetics than that in the normal volunteers. Experiments with diabetic rats indicated that the increased turnover of ascorbic acid was probably due to increased oxidation of ascorbate to dehydroascorbate in tissue mitochondria. Ascorbic acid supplementation at a dose of 500 mg per day for a brief period of 15 days resulted in an increase in the plasma ascorbate level temporarily, but it did not lower the blood glucose level of the diabetic patients.

Adolescent↗
PubMed1981

Antibiotic blood concentrations in patients successfully treated with tobramycin.

Thirty-nine patients with severe Gram-negative infections were treated with parenteral tobramycin. Thirty-one (79%) were cured of their infection. Tobramycin was most effective in the therapy of patients with urinary tract infections, arthritis and skin and soft tissue infections and relatively less effective in patients with septicaemia, pneumonia, and osteomyelitis. The infection was cured more frequently in patients who achieved a high ratio between the peak serum concentration of tobramycin and the minimal inhibitory concentration of tobramycin against the pathogenic organism (so-called therapeutic ratio). The ratio was greater than 4.0 in 11 of 13 (85%) assays performed in 12 cured patients, whereas this ratio was achieved in only 3 of 10 (30%) instances in 5 patients in whom the therapy failed (P less than 0.05). The latter group also included a greater proportion of patients with an ultimately fatal illness, such as lung cancer and uraemia, compared to the former successfully treated group. Adverse effects of tobramycin on renal function were transitory. No significant effect of tobramycin on the hearing was observed.

Adult↗
PubMed1981

Polyacrylamide gel electrophoresis and infrared spectroscopy of vibrio biotypes.

Polyacrylamide gel electrophoresis and infrared spectroscopy were used to study the relationship between Vibrio cholerae (classical), Vibrio cholerae (El Tor), and nonagglutinable (NAG) vibrios. Acid extracts of the different strains produced type-specific electrophoretic patterns, and the infrared spectra revealed broad absorption maxima which largely correspond to those found in other organisms. With the exception of the NAG vibrios, the infrared spectra of cholera El Tor vibrios were identical. Strain-specific differences were found in the exoprotein spectra of these organisms by the sodium dodecyl sulphate - polyacrylamide gel electrophoretic technique.

Bacterial Proteins↗
PubMed1981

Early evaluation of Ia monoclonal antibodies in prolonging non-human primate skin allograft survival.

Monoclonal antibodies (MCA) specific against one subset of lymphocytes (anti-B) were used in treating skin allograft rejection in Rhesus monkeys. Rhesus monkeys were treated daily with intravenous MCA until the skin graft was rejected. The dose of the MCA was adjusted according to the peripheral B-cell counts obtained by rosetting technique as well as by indirect immunofluorescence. We finally achieved a safe dose, though the margin of safety was narrow. We also noted that the B-cell count dropped to a significant degree and that the survival of the skin graft was prolonged.

Animals↗