Biomedical subjects
Publications and source records attributed to A K Banerjee.
The presentation of peptic ulcer in 132 elderly patients is compared with that in 67 younger patients. Abdominal pain was not present in one third of the elderly group. Absence of pain was associated with the older age group to a highly significant degree (P less than 0.001).
Soluble transcriptase containing the L and the NS proteins was isolated from purified vesicular stomatitis virus and its binding with the template ribonucleoprotein containing the N protein-RNA complex was studied with respect to its ability to initiate and synthesize RNA in vitro. By using u.v.-irradiated template reconstituted with soluble transcriptase, it was shown that the synthesis of leader RNA and other small initiated mRNA sequences continued while full-length mRNA synthesis decreased by 90%. In the presence of ATP and CTP, the reconstituted complex synthesized polyphosphorylated oligonucleotides which include AC, AAC and AACA which represent 5'-terminal sequences transcribed from the leader template and genes coding for mRNAs. In the presence of arabinosyl ATP, an inhibitor of RNA synthesis in vitro, the synthesis of leader RNA was found to be inhibited considerably more than other small initiated mRNA sequences. Reconstitution of RNA synthesis with soluble transcriptase and template in the presence of viral matrix (M) protein at low ionic condition resulted in virtual cessation of leader RNA synthesis, although the synthesis of small initiated N mRNA, 11 to 14 bases, continued. These results suggest that transcriptase can bind at multiple sites on the genome template and initiate RNA chains.
Two dissociable proteins, L and NS, and N-RNA template were purified from two serologically distinct vesicular stomatitis viruses, Indiana [VSV(IND)] and New Jersey [VSV(NJ)]. Requirements for RNA synthesis in heterologous reconstitution reactions in vitro were studied. The L and NS proteins of VSV(NJ) failed to synthesize full-length leader RNA and mRNAs in vitro when reconstituted with N-RNA(IND) template. However, when purified homologous NS(IND) was added to the reaction mixture, mRNA synthesis ensued. The requirements for transcription of N-RNA(NJ) template were different from those for N-RNA(IND). For RNA synthesis, transcription specifically required L(NJ), but the NS(NJ) and NS(IND) proteins were interchangeable. This suggests that there are specific domains on the L(NJ) protein, at which NS proteins of both serotypes may interact to form an active RNA polymerase complex, whereas L(IND) lacked such domains for interaction with NS(NJ). The function of the L protein appeared primarily to initiate RNA chains, and the NS protein was required for chain elongation. The results of these in vitro complementation experiments are discussed in light of previous in vivo complementation studies.
A rare case of actinomycotic osteomyelitis with an intracranial granuloma is presented. The computerized tomography findings are probably the first of their kind. Both the site of osteomyelitis and clinical presentation are unusual. The pertinent literature is reviewed.
A totally cystic giant cavernous hemangioma is described in a 3-year-old girl. The clinical presentation and computerized tomography findings were both unique. The patient was successfully treated by surgery.
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.
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.
Explore the source record for details and available documents.
Twenty four young (mean age 29.2 years, range 25-35) and 21 elderly (mean age 66.5, range 60-80) healthy subjects collected their urine in timed aliquots over 24 hours. The elderly subjects had been selected for their fitness by clinical and laboratory examinations and all lived independently at home. Sodium and potassium excretions were reduced in the elderly subjects compared with the young subjects, potassium excretion considerably so. This was despite similar 24 hour urine volumes and total solute excretion by both groups. The ratios of rates of excretion of water, electrolytes, and solutes during the night to the rates of excretion during the day were found to be higher in the elderly than the young subjects. Reduced day to night ratios of urinary excretion may be partly responsible for complaints of nocturia and sleep disturbance in elderly people.
Microinjection of purified transcriptionally active ribonucleoprotein (RNP) complex of vesicular stomatitis virus in vero cells resulted in the production and release of virus. Compared to the release of virus by cells treated with RNP in the presence of DEAE-dextran, the microinjection technique was highly efficient. Microinjection in Xenopus oocytes also resulted in initiation of infection as shown by the synthesis of virus-specific proteins in the cell cytoplasm. It was further observed that RNP stripped of L protein but containing residual NS protein was capable of initiating virus production or protein synthesis when microinjected in vero cells or in oocytes, respectively. Since L and NS proteins are essential for in vitro transcription by RNP, these results suggest that a trace amount of L protein may remain bound to the RNP and a host factor may stimulate residual L activity in vivo.
A soluble protein fraction containing L, NS, G and M proteins of vesicular stomatitis virus was prepared by treatment of Triton-disrupted virions with 0.8M NaCl. Incubation of the soluble fraction with beta-32P GDP followed by analysis of the proteins by polyacrylamide gel electrophoresis showed specific labeling of the NS protein. The NS-GDP complex was sensitive to phosphatase treatment, suggesting non-covalent binding. No binding of GDP to NS protein was detected when the soluble fraction was pre-heated at 100 degrees C for 1 min. or Mg++ was omitted from the incubation mixture. The binding was inhibited by ATP consistent with competition for a common nucleotide binding site.
A streptomycete producing an antibiotic having antifungal and antibacterial activity was isolated from a soil sample of West Bengal. It was characterized and identified as Streptomyces galbus. The antibiotic was isolated from the fermented broth by treatment with activated charcoal and purified by chromatography on alumina and paper. It is a colourless, odourless, hygroscopic, amorphous compound. Although homogeneous by paper and thin-layer chromatography, the possibility of the presence of two components was indicated by gel filtration. Its physico-chemical characteristics and UV-absorption spectrum suggest a non-polyenic nature. It is active against a wide variety of fungi and bacteria. It has some phytotoxic effect, but is relatively non-toxic to rats.