Biomedical subjects
Publications and source records attributed to M Maiti.
The structural polypeptides of the cholera bacteriophage phi 2 have been analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Eight different polypeptides were identified. The apparent molecular weights of the polypeptides were 143 000, 96 500, 68 000, 53 000, 37 500, 29 500, 21 000, and 13 500, respectively. The percentage of total protein corresponding to each polypeptide was estimated.
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.
Explore the source record for details and available documents.
Purified preparations of cholera bacteriophage phi2 were treated with cold phenol and the nucleic acid examined for its hydroxyapatite chromatographic pattern, thermal denaturation profile, base composition and mol. wt.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Bacteriophage phi 149 which was propagated in Vibrio cholerae (classical) OGAWA 154 strain, killed Vibrio cholerae (El Tor) strain MAK 757 without phage propagation. El Tor vibrios underwent a small degree of lysis only when infected by the phage phi 149 at a high multiplicity of infection and lost their viability at a rate-dependent multiplicity of phage infection. Evidence was obtained with 32P-labelled bacteriophage phi 149 for penetration of phage DNA into both bacterial strains. In host strain (OGAWA 154) phage particle synthesis occurred normally. In El Tor strain MAK 757 the phage DNA was not degraded but its expression was blocked. The killing effect of phi 149 on El Tor strain MAK 757 is supposed to be due to damage of the cytoplasmic membrane, which could not be repaired under the influence of phage information. This was indicated by a blockage of cellular respiration and RNA and protein synthesis.
Explore the source record for details and available documents.
Cholera and El Tor lipopolysaccharide (LPS) were identical in respect of chemical composition except that the hexosamine content was significantly lower and galactosamine was absent in El Tor LPS. Mukerjee's group IV cholera phage phi149 was inactivated by cholera LPS but was resistant to El Tor LPS.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
DN forms a complex with furazolidone producing thereby a quenching and a bathochromic shift of the drug absorption pattern. The binding isotherm was a non-linear one indicating involvement of more than one binding process in the formation of the furazolidone - DNA complex. The furazolidone - DNA complex inhibited digestion of DNA by DNAase and stabilized DNA against thermal strand separation by a significant degree.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Furazolidone in concentrations which had little effect on the growth of host organisms greatly reduced the yield of phage phi149 from the host Vibrio cholerae OGAWA 154. This phage was resistant to the in vitro action of the drug. The phage yield of infected bacteria depended significantly on the time of addition or withdrawal of the drug. The average burst size of the drug-treated and infected bacteria decreased exponentially with increase in drug concentration. The latent period of phage multiplication and also the eclipse period did not change significantly from the control values. A concentration of 0.05 mug of furazolidone per ml inhibited DNA synthesis by about 50% in phage-infected cells and only by about 18% in noninfected ones, relative to the respective controls. RNA and protein synthesis were affected by a much smaller degree both in infected and noninfected cells. Quantitative deduction of the length of furazolidone-treated cells from their phage adsorption characteristics and its agreement with previous electron microscopy data indicated that furazolidone did not affect the phage receptors.
Explore the source record for details and available documents.