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Biomedical subjects

A K Banerjee

Publications and source records attributed to A K Banerjee.

At least 307 records · Page 17Linked to original sources
PubMed1987

Intergenic sequences of the vesicular stomatitis virus genome (New Jersey serotype): evidence for two transcription initiation sites within the L gene.

The intergenic sequences of vesicular stomatitis virus of the New Jersey serotype [VSV (NJ): Ogden strain] have been determined by dideoxy sequencing across the gene junctions of the viral RNA genome using deoxyoligonucleotide primers. The N-NS, NS-M, and M-G intergenic sequences of VSV (NJ) are identical to the consensus intergenic sequence for VSV of the Indiana serotype [VSV (IND)]: 3'-AUACU7GAUUGUCNNNAG-5' (genome sense; N denotes any nucleotide), where 3'-AUACU7-5' encodes the 3' terminus and the start of the polyadenylate tract of the preceding mRNA, 3'-UUGUCNNNAG-5' encodes the 5' terminus of the succeeding mRNA, and 3'-GA-5' is a nontranscribed dinucleotide. Notably, the NS-M junction of VSV (NJ) does not contain the anomalous dinucleotide 3'-CA-5' which is found at the NS-M junction of VSV (IND). In striking contrast to VSV (IND), the G-L intergenic sequence of VSV (NJ) contains a 19-base insertion between the nontranscribed dinucleotide and the consensus mRNA start sequence. During in vitro transcription, the L mRNA of VSV (NJ) may initiate at two distinct sites: the first start site (3'-CCUUAUCUUC-5') is that flanking the nontranscribed dinucleotide, and the second start site is a consensus mRNA start sequence located 20 bases downstream from the nontranscribed dinucleotide. However, the L mRNA isolated form VSV (NJ)-infected cells appears to initiate only at the consensus start sequence. The possible role of these start sites in L mRNA synthesis is discussed.

Amino Acid Sequence↗
PubMed1987

Selective inhibition of protein synthesis by synthetic and vaccinia virus-core synthesized poly(riboadenylic acids).

Studies were undertaken to compare the effect of poly(A)s from various sources on selective inhibition of protein synthesis in the reticulocyte lysate system programmed with viral and cellular mRNAs. RNA synthesized in vitro by vaccinia virus cores in the presence of only ATP inhibited overall HeLa cell polypeptide synthesis by over 80% with a minimal effect on translation of vaccinia virus mRNAs. Hybridization of the [alpha-32P]AMP-labeled RNA made in vitro by vaccinia virus cores in the presence of only ATP, showed no complementary to HindIII restriction fragments of vaccinia virus DNA indicating that the in vitro product was poly(A). Fractionation of synthetic and core-synthesized poly(A) into three size classes showed that the larger the size of poly(A), the greater its inhibitory activity of protein synthesis in the cell-free system. Inhibition of translation of mRNAs from vaccinia virus-infected HeLa cells was also observed in the presence of poly(A). However, virus-induced polypeptide synthesis was more resistant to the effect of poly(A) than were cellular polypeptides. Oligo(dT) when added to the reticulocyte lysate system was capable of reversing the inhibition of protein synthesis caused by both core-synthesized poly(A) and core-transcribed RNAs. These results indicate that poly(A) synthesized by the virion-associated enzyme has inhibitory properties similar to those of synthetic poly(A).

Cell-Free System↗
PubMed1987

Sequences of Chandipura virus N and NS genes: evidence for high mutability of the NS gene within vesiculoviruses.

The nucleotide sequence of the 3' end of the genome of Chandipura (CHP) virus, including the complete sequences of the nucleocapsid (N) and phosphoprotein (NS) genes was determined, principally from cloned cDNAs of the N and NS mRNAs. The NS mRNA of CHP virus is 908 bases in length and encodes a protein of 293 amino acids. Comparison of the CHP virus NS protein sequence with those of vesicular stomatitis virus of the New Jersey serotype (VSV (NJ)) and of the Indiana serotype (VSV (IND] revealed homologies of only 23 and 21%, respectively, with no consecutive stretches of more than four amino acids identical among the three sequences. As with the two VSV serotypes, the highest homology between the NS proteins of CHP and VSV was in a 20-amino acid region near the carboxy termini of the proteins. Of the potential phosphorylation sites, there are eight conserved serine or threonine residues among the three sequences. Despite the dissimilarity among primary sequences of the NS proteins, their overall structure, as assessed by amino acid composition and by the relative hydropathicities of the sequences, has been conserved throughout evolution. The N mRNA of CHP virus is 1291 bases long and encodes a protein of 422 amino acids. In contrast to the NS protein, the CHP N protein is at least 50% homologous to the N proteins of each of the VSV serotypes. We have identified a region near the center of these N protein sequences which is conserved among members of both the rhabdovirus and paramyxovirus families. This extent of conservation of the N protein sequences underscores the high rate of mutability of the NS protein sequences among the vesiculoviruses.

Amino Acid Sequence↗
PubMed1987

Complete nucleotide sequence of the matrix protein mRNA and three intergenic junctions of human parainfluenza virus type 3.

The complete sequence of the gene encoding the matrix protein (M) of human parainfluenza virus type 3 (PIV-3) was determined from cDNA clones and from primer extension dideoxy sequencing of the viral genome. The M mRNA is 1150 nucleotides in length, exclusive of polyadenylate, and codes for a protein of 353 amino acids, having a calculated molecular weight of 39,480. The M protein of PIV-3 was found to have a high degree of sequence homology with that of a closely related paramyxovirus, Sendai virus, and to a lesser extent it contained sequence homology with two more distant paramyxoviruses, measles virus and canine distemper virus. We also determined the sequences of the intergenic junctions for the first four genes of PIV-3: NP, P, M, and F. Comparison of these sequences yielded a consensus mRNA start sequence of 5'-AGGANNAAAGA-3', an mRNA end sequence of 5'-UAAGAAAAA-3', and an intergenic sequence of 5'-CUU-3'. The end sequence of the M gene is unusual in that it contains an eight base insertion prior to the A5 tract found in the consensus sequence. This disruption appears to cause a high frequency of readthrough by the viral transcriptase at this junction.

Amino Acid Sequence↗
PubMed1987

Congenital intramedullary spinal ependymal cyst.

A rare case of congenital intramedullary ependymal cyst of the dorsal cord in a 7-year-old boy associated with kyphoscoliosis and rachidian malformations of the dorsal spine is reported. Myelography suggested an intramedullary lesion. The posterior location and presence of a clear plane of cleavage from the medullary tissue enabled total enucleation of the cyst. Histological differentiation from other similar intradural cysts is discussed and the relevant literature is reviewed. This is the fifth such case reported in the literature.

Child↗
PubMed1987

Intramedullary spinal cysticercosis. Case report and review of literature.

Intramedullary spinal cysticercosis is extremely uncommon; only 29 cases have been reported previously. A case of solitary intramedullary spinal cysticercosis is described. Factors accounting for the rarity of intramedullary cysticerci are reviewed and the probability of reaching a preoperative diagnosis is discussed. This is the fifth such case reported from India.

Adult↗
PubMed1987

Two separate domains within vesicular stomatitis virus phosphoprotein support transcription when added in trans.

The structural phosphoprotein NS of vesicular stomatitis virus, in association with the virion-associated RNA polymerase L protein, transcribes the genome ribonucleoprotein template in vitro. It contains an acidic N-terminal domain and two distinct domains at the C-terminal end that are involved in binding to the polymerase protein and the template RNA enwrapped with the nucleocapsid protein. In the present study, the portions of the NS gene that encode the N- and C-terminal domains of the protein were cloned in pGEM vectors and expressed by in vitro transcription and translation. It was shown that two polypeptides obtained by translation of the encoded mRNAs support RNA synthesis in vitro in a reconstitution reaction when they are added together in trans. Moreover, the N-terminal domain can be functionally substituted by structurally similar polypeptides.

Capsid↗
PubMed1987

Gastritis and gastric campylobacter-like organisms in patients without peptic ulcer.

Gastric biopsy specimens were obtained from 83 patients without peptic ulcer disease and analysed histologically. Culture and serological studies were done on the last 64 patients. The patients were divided into two age groups (young and old groups.) In 34 patients with chronic superficial gastritis, gastric campylobacter-like organisms (GLCO) were identified histologically in 91% and grown on culture in 88%: antibody to GCLO was detected in 81%. No age-related difference in the prevalence of the organism was demonstrated. In the 23 patients with atrophic gastritis (all elderly), presence of the organisms appeared to be related to the presence of an inflammatory cell infiltrate into the gastric mucosa. These figures for the prevalence of the organism in this selected group of patients are similar to those reported in previous studies of unselected patients which included those with peptic ulcer. This suggests that GCLO is unlikely to be causally related to peptic ulcer.

Adult↗
PubMed1987

An alternative method for the decontamination of rats carrying Mycoplasma pulmonis without the use of germfree isolators.

Two strains of Lewis rat were successfully freed from Mycoplasma pulmonis infection by using a combination of oral treatment with oxytetracycline hydrochloride and obtaining young by hysterectomy. Laminar flow cabinets were used to perform hysterectomies on donor animals and for rearing hysterectomy-derived animals. After thorough microbiological examination the rats were brought to the breeding colony of the Laboratory Animal Centre. Periodic laboratory tests using both cultural and enzyme-linked immunosorbent assay methods showed that the animals have remained free from M. pulmonis for the last 3 years.

Animals↗
PubMed1987

Acute diarrhoeal disease in rabbit: bacteriological diagnosis and efficacy of oral rehydration in combination with loperamide hydrochloride.

Acute outbreaks of diarrhoea with high mortality rates are frequently observed in rabbits. Amongst various aetiological factors Escherichia coli or its toxins have been found to be commonly incriminated. Sulphonamides or antibiotics are used to treat rabbits with bacterial diarrhoea. The result of the antibiotic treatment is moderately successful. We had good results using oral rehydration treatment in combination with loperamide hydrochloride (Immodium) in a colony of rabbits with E. coli diarrhoea.

Acute Disease↗
PubMed1987

Gastrointestinal transit following intrathecal or subcutaneous narcotic analgesics.

This paper reports investigations on the effects on gastrointestinal transit of subcutaneous or intrathecal administration of opiates: morphine, sufentanil and alfentanil. Subcutaneous administration of opiates produced a significant dose-dependent decrease in transit of a charcoal meal test. Intrathecal administration of morphine to Wistar rats with catheter chronically implanted in the subarachnoid space did not cause a decrease in gastrointestinal transit. However, in freshly prepared rats with intrathecal catheter in the subarachnoid space, morphine significantly decreased intestinal transit of charcoal meal. In addition, sufentanil and alfentanil, on intrathecal administration in rats with chronically implanted catheters, caused a marked dose-dependent slowing of the passage of meal. Prior s.c. administration of the opiate antagonist naloxone completely blocked the depression of gastrointestinal transit caused by high doses of intrathecal sufentanil and s.c. administered morphine.

Alfentanil↗