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Biomedical subjects

R Banerjee

Publications and source records attributed to R Banerjee.

At least 181 records · Page 10Linked to original sources
PubMed1991

Transmission of viable Mycobacterium leprae by Aedes aegypti from lepromatous leprosy patients to the skin of mice through interrupted feeding.

Female Aedes aegypti which took partial blood meals from the skin lesions of untreated lepromatous leprosy (LL) patients were then allowed to continue feeding on 72-96-hr-old Swiss albino suckling mice (Rockefeller strain). The bitten portion of skin was removed, divided into two parts and processed for the extraction of bacilli by two different methods using chloroform and petroleum ether. The proboscis of some of the fed mosquitoes was dissected out and examined for viable bacilli (stained by fluorescein diacetate and ethidium bromide) and acid-fast bacilli (AFB). Out of 50 probosces dissected 45 were found positive for AFB, with bacillary counts ranging up to 246 (average 40.20 +/- SD 41.80) per proboscis. The average percentage of viable bacilli (green solid) in the probosces immediately after feeding on LL patients was 43.90 and thereafter it decreased gradually to 3 on the seventh day. In the petroleum ether extract of mouse skin viable bacilli were observed in numbers up to 37 (average 15.25 +/- SD 10.25) per smear. The number of fluorescing bacilli (green and red) correlated with the total number of AFB.

Aedes↗
PubMed1990

Selective inhibition of hepatitis B virus and human immunodeficiency virus sequence-promoted gene expression by cotransfected poly(I):poly(C).

The transient expression of hepatitis B virus (HBV) surface and "eJ" antigens caused by transfection of human hepatoblastoma HepG2 cells with HBV DNA was markedly inhibited by cotransfection with poly(I):poly(C). Cotransfection with poly(I):poly(C) also inhibited the expression of bacterial chloramphenicol acetyltransferase (CAT) gene which was under the control of either the HBV core promoter or the human immunodeficiency virus (HIV-1) long terminal repeat. This inhibition was much more pronounced on the expression of HBV-promoted CAT than HIV-promoted CAT. The uptake of reporter plasmid was not affected by cotransfected poly(I):poly(C). The inhibition was found to be at the steady-state CAT mRNA level and appeared to be specific for HBV and HIV regulatory sequences since CAT expression directed by other viral and cellular regulatory sequences was not inhibited. Cotransfection with a mixture of equal amounts of poly(I) and poly(C) had similar inhibitory effects whereas cotransfection with poly(l) or poly(C) alone, or other double-stranded ribo- or deoxyribonucleotides, did not have such strong effects. The addition of poly(l):poly(C) to the culture medium of cells transfected with these reporter plasmids caused little inhibition. Transfection with poly(l):poly(C) induced a minimal amount of intracellular interferon-alpha in HepG2 cells which may be involved in selective inhibition of HBV-and HIV-1-directed gene expression. 2-Aminopurine, an inhibitor of double-stranded RNA activated protein kinase known to block interferon gene induction by poly(l):poly(C), partially reversed the poly(l):poly(C)-induced inhibitory effect on HBV-CAT expression.

2',5'-Oligoadenylate Synthetase↗
PubMed1990

Transmission of Mycobacterium leprae from lepromatous leprosy patients to the skin of mice through intermittent feeding.

Batches of hungry Aedes aegypti mosquitoes which partially sucked blood from the skin lesions of proved untreated lepromatous leprosy (LL) patients were allowed immediately to feed on a portion of the skin of a cleanly shaved swiss mouse. The portion of the skin was cut, homogenized on the same day and extracted with chloroform. Out of 10 extracts, stained for acid fast bacilli (AFB), Mycobacterium leprae were demonstrated in eight, indicating transfer of bacilli mechanically to the biting spot through intermittent feeding. Out of 50 probosces dissected and stained for AFB, M. leprae were demonstrated in 45.

Aedes↗
PubMed1990

Heterotypic and homotypic cell-cell adhesion molecules in endothelial cells.

Sickle red blood cells display an abnormal propensity to adhere to cultured bovine aortic endothelial cells when compared to normal red blood cells. The adherence was potentiated three-fold by endothelial cell derived conditioned medium, enriched in multimers of von Willebrand factor. Such adherence was ablated by 80% by either the synthetic peptide (RGDS) or antibody to GPIIb/IIIa, indicating the presence of RGD peptide recognition domain/receptor in either endothelial cells or sickle cells or both. The adherence was also inhibited by 70% by phosphatidylserine, but not by other phospholipids, indicating the presence of putative receptors for this phospholipid in endothelial cells. The labeling of cultured bovine aortic endothelial cells with monoclonal antibodies revealed the localization of MAB D2 to regions of cell-cell contact. The antigen on endothelial cells which cross-reacts with this antibody has a Mr of 130,000. The addition of such an antibody during the plating of endothelial cells disrupted monolayer formation. It appears that a 130-kDa polypeptide antigen in endothelial cells which is recognized by MAB D2, may be a cell-cell adhesion molecule.

Amino Acid Sequence↗
PubMed1989

Banerjee replies.

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Journal Article↗
PubMed1989

Tumor necrosis factor-alpha induces a kappa B sequence-specific DNA-binding protein in human hepatoblastoma HepG2 cells.

Tumor necrosis factor-alpha is an inducer of acute-phase protein synthesis in liver cells. The mechanism by which tumor necrosis factor-alpha alters gene expression in these cells is largely unknown. In this study, we demonstrate that tumor necrosis factor-alpha stimulates human immunodeficiency virus-1 long terminal repeat-promoted gene expression in the human hepatoblastoma HepG2 cell line and increased binding of trans-activating factors to kappa B (kappa B) DNA sequences. In contrast to lymphocytic cells where the nuclear factors recognizing the kappa B sequences are activated by both tumor necrosis factor-alpha and phorbol-12-myristate-13-acetate through a posttranslational mechanism, in HepG2 cells phorbol-12-myristate-13-acetate does not activate these factor(s), and de novo protein synthesis seems to be required in HepG2 cells for gene activation by tumor necrosis factor-alpha.

Base Sequence↗
PubMed1989

Inhibition of the replication of hepatitis B virus by the carbocyclic analogue of 2'-deoxyguanosine.

We report that treatment of 2.2.15, a human hepatoblastoma-derived cell line in which hepatitis B virus is actively replicating, with the carbocyclic analogue of 2'-deoxyguanosine [Shealy, Y. F., O'Dell, C. A., Shannon, W. M. & Arnett, G. (1984) J. Med. Chem. 27, 1416-1421] resulted in the nearly complete cessation of viral replication, as monitored by the absence of both intracellular episomal and secreted viral DNAs and by the absence of viral DNA polymerase activity. The drug was nontoxic in concentrations up to 200 times the minimum effective inhibitory concentration.

Antiviral Agents↗
PubMed1988

Inhibition of c-H-ras oncogene induced transformation of rat embryo fibroblasts by cotransfected polynucleotides containing alternating purine-pyrimidine sequences.

When Rat 6 cultures were cotransfected with an activated c-H-ras oncogene (pT24) and poly(dG-m5dC), a synthetic polymer that has the potential to form Z DNA, there was marked inhibition of cell transformation. Cotransfection of pT24 DNA with poly(dG-dC) caused somewhat less inhibition, poly(dA-dC). (dG-dT) caused moderate inhibition, and poly(dG). (dC) exerted negligible inhibition. Evidence was obtained that the inhibition seen with poly(dG-m5dC) was not simply due to an inhibition of cellular uptake of the pT24 DNA. Our results suggest that certain polymers that have the potential to form Z DNA can inhibit the integration and expression of a transfected oncogene.

Animals↗
PubMed1988

Preferential cytotoxicity on tumor cells by caffeic acid phenethyl ester isolated from propolis.

The honeybee hive product, propolis, is a folk medicine employed for treating various ailments. Many important pharmaceutical properties have been ascribed to propolis, including anti-inflammatory, antiviral, immunostimulatory and carcinostatic activities. Propolis extracts have provided an active component identified as caffeic acid phenethyl ester (CAPE), which was readily prepared in one step. Differential cytotoxicity has been observed in normal rat/human versus transformed rat/human melanoma and breast carcinoma cell lines in the presence of CAPE.

Animals↗
PubMed1988

Cystic mucinous tumours of the mesentery and retroperitoneum: report of three cases.

A mucinous cystadenoma of the mesentery and two borderline mucinous cystadenocarcinomas of the mesentery and retroperitoneum are reported. The patients were females, aged 38, 47 and 58 years. The cysts showed identical features to those commonly seen in the appendix and ovary. One of our cases, with 'borderline' histology, developed metastases to mediastinal lymph nodes, 4 years after diagnosis. We suggest that these tumours develop through mucinous metaplasia in pre-existing mesothelium-lined cysts, the latter being the commonest cysts in this location.

Adult↗
PubMed1988

Identification of protein-binding sites in the hepatitis B virus enhancer and core promoter domains.

We have investigated the role of liver-specific trans-acting factor(s) in the regulation of hepatitis B virus (HBV) gene expression. A recorder plasmid (pEcoAluCAT; HBV nucleotides 1 through 1878) was constructed containing the HBV enhancer and the promoter region of the pregenomic RNA, which was ligated to the bacterial chloramphenicol acetyltransferase (CAT) gene. Upon transfecting this plasmid into various cell lines, the CAT gene was expressed only in cells of liver origin. Moreover, competition cotransfections with pEcoAluCAT and plasmids containing HBV enhancer sequences in human hepatoblastoma-derived HepG2 cells indicated the presence of titratable trans-acting factor(s) in these cells. Gel mobility shift assays using HBV enhancer and core promoter domains confirmed the existence of sequence-specific DNA-binding proteins in liver cell nuclear extract which bound to these regions. These binding sites encompass 17- and 12-nucleotide palindromes in the HBV enhancer and core promoter domains, respectively, when mapped by the methylation interference assay.

Base Sequence↗
PubMed1987

Effect of internal irradiation on the maturing Purkinje cells in the rat. A Golgi study.

Continuous irradiation in utero is reported to produce mental retardation and gross abnormalities of the brain in the human. A few experimental studies conducted so far also report gross brain defects in animals exposed to continuous irradiation in utero. Despite the increasing use of nuclear energy for power and radioisotopes in medicine, there is hardly any literature available on the effect of continuous irradiation on the structural details of the developing brain. After intraperitoneal injections of different doses of 131I (8, 18 and 32 microCi) and 32P (10 microCi) in new-born rats on the 6th postnatal day, cerebella stained by Golgi techniques were cut sagittally and the sections were examined on the 10th, 15th and 21st postnatal days. In the animals injected with 18 and 32 microCi of 131I and 10 microCi of 32P a large number of Purkinje cells showed morphological alterations not seen in the control groups or in the groups injected with 8 microCi of 131I. The changes observed included persistence of the perisomatic processes beyond the 10th postnatal day, multiple primary dendrites, angulation of the primary dendrites, long segments of primary dendrites without branches and significantly reduced dendritic volume. The number of affected cells was less on the 21st postnatal day. The effective radiation dose estimated in these groups ranged from 15 to 26 rad. Since the rats irradiated with 6 rad had not shown such changes it is believed that there is a threshold dose of radiation beyond which only changes are perceptible at neuronal level.

Age Factors↗
PubMed1987

Biliary neoplasia in Gardner's syndrome.

Familial adenomatous polyposis coli is now known to encompass a more complicated spectrum of anomalies than was initially suspected. The term Gardner's syndrome, broadened from its original definition, currently includes all cases of familial polyposis coli with extracolonic neoplasms. Small-bowel adenomata occur in approximately 12% of these patients, and sporadic instances of biliary neoplasia have also been reported. We describe multifocal adenomatous change with severe dysplasia of the gallbladder in a young woman known to have familial adenomatous polyposis coli. Review of this and other such cases in the literature leads us to conclude that neoplasms of the biliary tree constitute a new component of Gardner's syndrome.

Adenoma↗