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Biomedical subjects

A K Banerjee

Publications and source records attributed to A K Banerjee.

At least 19 recordsLinked to original sources

A six year prospective study of fibrinogen and other risk factors associated with mortality in stable claudicants.

A total of 333 patients with stable intermittent claudication at recruitment were followed up for 6 years to determine risk factors associated with subsequent mortality. Cardiovascular diseases were the underlying cause of death in 78% of the 114 patients who died. The strongest independent predictor of death during the follow-up period was the plasma fibrinogen level, an increase of 1 milligram being associated with a nearly two-fold increase in the probability of death within the next 6 years. Age, low ankle/brachial pressure index and a past history of myocardial infarction also increased the probability of death during the study period. The plasma fibrinogen level is a valuable index of those patients with stable intermittent claudication at high risk of early mortality. The results also provide further evidence for the involvement of fibrinogen in the pathogenesis of arterial disease.

Aged

Phosphorylation by cellular casein kinase II is essential for transcriptional activity of vesicular stomatitis virus phosphoprotein P.

We have previously shown that phosphorylation of vesicular stomatitis virus (VSV) phosphoprotein P by cellular protein kinase activity is an essential prerequisite for its transcriptional function. We have now purified this protein kinase by monitoring its ability to phosphorylate bacterially expressed, unphosphorylated P protein. Biochemical studies showed that the kinase is indistinguishable from casein kinase II, a ubiquitous cyclic AMP-independent protein kinase present in a wide variety of eukaryotic cells and tissues. Functional VSV transcription could be reconstituted with viral L protein, N-RNA template, and P protein phosphorylated by either purified cellular protein kinase or purified casein kinase II. The unusual role of casein kinase II in the transcription process of a nonsegmented negative-strand RNA virus would have important implications in host-virus interactions and antiviral therapy.

Capsid

Surgical treatment of hidradenitis suppurativa.

The management of hidradenitis suppurativa is frequently unsatisfactory. No method satisfies all requirements for the ideal treatment--quick healing, no hospital admission, minimal patient inconvenience and low recurrence--but greater awareness of the strengths and weaknesses of existing methods should lead to improved management. Good reports of the relative cure rates of the different surgical options are scarce and controlled trials non-existent, but existing evidence is reviewed critically and summarized. The operation of choice in most instances is wide local excision and healing by secondary intention.

Hidradenitis Suppurativa

Relationship between eye and skin irritation in rabbits using a series of textile fiber finishes.

A series of 76 fiber finishes, typically composed of blends of lubricants, emulsifiers, antistatic agents and fatty acid soaps, were tested in rabbits to determine both the eye and the skin irritation potential. Each finish was classified as being either non-, slightly, mildly, moderately or severely irritating to the target tissue during a 48-h post-treatment period. Seven (9.2%) of the finishes tested were severely irritating to both the skin and the eye; two (2.6%) were determined to be non-irritating to both tissues. While occasionally finishes produced equal degrees of damage resulting in similar irritancy classifications, seven (9.2%) finishes were found to be severely irritating to the skin without producing any irritation in the eye. Conversely, one finish was found to be a severe eye irritant without producing any skin irritation. The suggested use of the skin irritation data to predict the ocular reaction needs to be carefully examined, particularly with materials such as these fiber finishes. The prediction that a severe skin irritant is also a severe eye irritant was demonstrated to be in error with 8 of 75 (10.5%) of the finishes studied. Further, there is little predictive association between the skin and eye irritation for these compounds.

Animals

RNA editing in the phosphoprotein gene of the human parainfluenza virus type 3.

RNA editing of the human parainfluenza virus type 3 (HPIV3) phosphoprotein (P) gene was found to occur for the accession of an alternate discontinuous cistron. Editing occurred within a purine-rich sequence (AAUUAAAAAAGGGGG) found at the mRNA nucleotides 791-805. This sequence resembles an HPIV3 consensus transcription termination sequence and is located at the 5'-end of the putative D protein coding sequences. Editing at an alternate site (AAUUGGAAAGGAAAGG), mRNA nucleotides 1121-1136, for accession of a conserved V cistron, which is present in a number of paramyxovirus P genes, was not found to occur in HPIV3. In contrast with many other paramyxoviruses, editing was indiscriminate with the insertion of 1-12 additional G residues not present in the gene template. RNA editing was found to occur in both in vivo (HPIV3 infected cells) and in vitro (purified nucleocapsid complexes) synthesized mRNAs. Further, the in vitro prepared mRNA was edited regardless of whether the nucleocapsid complexes were transcribed in the presence or absence of uninfected human lung carcinoma (HLC) cell lysates. These results support the notion that RNA editing appears to be exclusively a function of viral proteins.

Amino Acid Sequence

Bifrontal oligodendroglioma with bilateral symmetrical posterior communicating artery aneurysms.

A case of bifrontal oligodendroglioma with bilateral posterior communicating artery aneurysms, one symptomatic and the other incidental, is presented. This is the first instance of such a combination. Clipping of the aneurysm, along with partial tumour excision, was performed at the same sitting, successfully. Literature on this association is reviewed and the pathogenesis is discussed.

Brain Neoplasms

Endoscopic transthoracic sympathectomy in the treatment of hyperhidrosis.

A 5-year experience of 50 endoscopic transaxillary dorsal sympathectomies is presented. The procedure was successful in either curing or improving the symptoms of hyperhidrosis in the great majority of patients. The commonest side effects were compensatory sweating (75%) and gustatory sweating (48%); despite this, there was an extremely high level of patient satisfaction. Permanent Horner's syndrome did not occur. The procedure is effective, simple, cheap, and requires only an overnight stay; and is recommended as the method of choice for the surgical treatment of upper limb hyperhidrosis.

Adolescent

Restricted replication of vesicular stomatitis virus in T lymphocytes is coincident with a deficiency in a cellular protein kinase required for viral transcription.

Vesicular stomatitis virus (VSV) fails to replicate in mouse T lymphocytes unless the cells have been mitogenically stimulated with concanavalin A (Con A). We have examined the possibility that the failure of VSV to replicate in unstimulated T lymphocytes can be attributed to a deficiency in a host protein kinase which activates the viral P protein by phosphorylation, thus rendering it transcriptionally competent. Soluble extracts were prepared from purified mouse T lymphocytes, with or without prior treatment with Con A. The ability of these extracts to phosphorylate bacterially synthesized P protein of two VSV serotypes was measured in vitro. Activity of the protein kinase on the P proteins of the Indiana or New Jersey serotypes of VSV increased, on average 2.4- and 2.1-fold respectively, after treatment of the cells with 3 micrograms/ml Con A. Higher concentrations of Con A induced proportional increases (up to 10-fold) in the activity of the host protein kinase. Activities of the kinase phosphorylating the P protein in separate populations of CD4- and CD8-containing murine T lymphocytes increased similarly on mitogenic activation. No biochemical or immunological differences were observed between the T cell protein kinase and the previously characterized protein kinase (casein kinase II) from BHK-21 cells. The activity of the kinase that phosphorylates the P protein did not vary in CV-1 cells on treatment with alpha- or gamma-interferon, both of which inhibited VSV replication. Similarly, casein kinase II activities in Raji and SIRC cells, which do not normally support VSV growth, were the same as in BHK-21 cells. Thus restriction of VSV replication in these cells, in contrast to T lymphocytes, was not associated with a deficiency in the host casein kinase II activity.

Animals

Unilateral subungual hyperkeratosis following a cerebrovascular incident in a patient with psoriasis.

The prevalence of nail abnormalities in psoriasis is reported to be between 50 and 90% of affected adults. These include pitting, nail discoloration, onycholysis and subungual hyperkeratosis. Although nail changes may be associated with neurological disease, there are no previous reports of psoriatic nail changes following cerebrovascular events. We report the first case to our knowledge of unilateral subungual hyperkeratosis in a psoriatic patient which developed following a cerebrovascular event.

Cerebrovascular Disorders

Phosphorylation of specific serine residues within the acidic domain of the phosphoprotein of vesicular stomatitis virus regulates transcription in vitro.

The phosphorylated state of the vesicular stomatitis virus phosphoprotein (P), an essential component of the virion-associated RNA polymerase complex, has been shown to be important for the transcriptional activity of the complex. Recent studies indicate that phosphorylation within the acidic domain of the P protein by cellular casein kinase II is necessary for its activity. In an attempt to identify the exact location of the cell kinase-mediated phosphorylation, we altered specific serine and threonine residues within the acidic domain of the New Jersey serotype of P protein by site-directed mutagenesis. The altered P proteins were then tested to determine what effect these mutations had on the phosphorylated state of the protein in vivo as well as its transcriptional activity in vitro. We report that serine residues 59 and 61 within the acidic domain of the P protein must be phosphorylated for it to be functionally active in a reconstituted transcription assay. These results demonstrate the importance of site-specific phosphorylation in the transcriptional activity of a negative-strand RNA viral phosphoprotein and the crucial role played by a cell protein kinase in this process.

Base Sequence

Sequential phosphorylation of the phosphoprotein of vesicular stomatitis virus by cellular and viral protein kinases is essential for transcription activation.

The phosphoprotein (P) and the large protein (L) constitute the RNA-dependent RNA polymerase of vesicular stomatitis virus (VSV). We show that phosphate-free P protein expressed in bacteria is transcriptionally inactive when reconstituted with L protein and viral N-RNA template free of cellular protein kinase. Phosphorylation of P protein by a cellular kinase(s) was essential for transcription as well as for further phosphorylation by an L-associated kinase, the two kinases acting in a sequential (cascade) manner. Phosphate groups introduced by cell kinase were stable, whereas those due to L kinase underwent a turnover which was coupled to ongoing transcription. We present a model for the phosphorylation pathway of P protein and propose that continued phosphorylation and dephosphorylation of P protein may represent a transcriptional regulatory (on-off) switch of nonsegmented negative-strand RNA viruses.

Animals

Studies of gut mucosal protein synthesis in a non-steroidal anti-inflammatory drug (NSAID) model of inflammatory bowel disease.

The extent to which defects in protein synthesis occurred in an experimental indomethacin induced rat model of nonsteroidal enteropathy has been examined. Male rats (nine) were fed indomethacin (8 mg/kg/day) for three days mixed with a powdered form of chow. The control group of rats (nine) were fed the same diet for three days without indomethacin. After the feeding period, both groups were fed a normal solid diet for four days. At the end of this period, the fractional rates of intestinal protein synthesis was determined by the 'flooding dose' technique. The mucosal protein, RNA and DNA contents in the proximal ileum of animals with enteropathy were not significantly different from controls (p greater than 0.05). Experimental enteropathy induced selective increases in the fractional rates of protein synthesis (26% increase, p less than 0.03) and RNA activities (23% increase, p less than 0.04). There were no significant changes in any of these variables in the duodenum (p greater than 0.05 in all instances). These changes may partly reflect the activity of those processes responsible for the pathogenic changes in NSAID enteropathy.

Animals

Intracranial olfactory neuroblastoma: evidence for olfactory epithelial origin.

AIMS: To determine the possible histogenesis of the intracranial variant of olfactory neuroblastoma. METHODS: Four specimens from three cases of intracranial olfactory neuroblastoma were studied by light microscopy and immuno-histochemistry, and electron microscopy in two cases. RESULTS: Light microscopical examination showed small cell tumour with additional features of epithelioid cells in one case and ganglion cells in another. Olfactory and Homer-Wright rosettes were present. All the specimens showed a uniform positive reaction to neurone specific enolase, S-100, and cytokeratin antibodies. Glial fibrillary acidic protein was absent. The salient electron microscopic features were the presence of cell junctions, cytoplasmic intermediate filaments, basal bodies and cytolasmic processes. Dense cored vesicles were absent. CONCLUSIONS: The results strongly support the view that intracranial olfactory neuroblastomas are of olfactory epithelial origin and differ from conventional neuroblastomas.

Adult