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Biomedical subjects

D Banerjee

Publications and source records attributed to D Banerjee.

298 records · Page 17Linked to original sources
PubMedDate not supplied

Natural killer-like cells found in B-cell compartments of human lymphoid tissues.

Natural killer (NK) cells have been implicated in natural resistance to tumours, particularly lymphomas. Recently, they have been implicated in the regulation of human erythropoiesis. The distribution of NK cells in peripheral lymphoid tissues has not been fully documented. NK activity in human or murine lymph nodes is significantly lower than in the spleen or peripheral blood. In Hodgkin's disease, affected lymph nodes and spleens have higher NK activity than non-involved nodes or spleens. Using a monoclonal antibody (Leu 7) that defines the human NK antigen HNK-1 (ref. 8), only a small number of HNK-1+ cells were found in lymph nodes, tonsils or thymus, with greater numbers in the spleen. We report here the topographical distribution of HNK-1+ cells in normal human lymph nodes, tonsils and spleen and preliminary observations in various forms of malignant lymphoma. The most striking observation was that HNK-1+ cells were not distributed uniformly in these tissues but specifically localized in the B-cell compartments (follicular centres).

Antigens, Surface↗
PubMedDate not supplied

Malaria chemoprophylaxis in UK general practitioners traveling to South Asia.

BACKGROUND: Imported malaria continues to be a significant cause of morbidity and mortality in the United Kingdom. Low uptake and poor compliance of chemoprophylaxis are thought to be contributory factors. Little information is available on how well health care physicians comply with malaria chemoprophylaxis when they travel to malarial areas. The aim of this study was to determine the usage and compliance of malarial chemoprophylaxis by general practitioners who have traveled to South Asia. METHOD: A telephone survey of 172 general practitioners practicing in the West Yorkshire area of the UK who have traveled to South Asia. RESULTS: Of the 145 (84%) responding to the survey, 50 (35%) took no chemoprophylaxis, 28 (19%) did not complete the chemoprophylaxis course, and 67 (46%) were fully compliant. The reasons for noncompliance were; the belief the area visited was free from malaria (34%), no wish to take prophylaxis (18%), previous side-effects (10%), the belief of possessing long-term immunity (10%), no time to obtain prophylaxis (4%), malaria is easier to treat than to prevent (2%), costs of purchasing prophylaxis (2%), went for a short period of time and took the risk (2%), and no specific reason (18%). CONCLUSIONS: This study has shown that a large proportion of general practitioners questioned did not take the recommended antimalarial prophylaxis. If they themselves do not keep to the guidelines, it is of concern that they may not reinforce the taking of chemoprophylaxis by their patients. Training in travel medicine may improve chemoprophylaxis uptake by general practitioners, but until then, such physicians should not be regarded as the main provider of pretravel advice. All travelers including health care physicians should be aware, and should comply with malarial prophylaxis guidelines, with emphasis on chemoprophylaxis compliance and mosquito avoidance.

Antimalarials↗
PubMedDate not supplied

Pretreatment of endometrial carcinoma cell lines with butyrate results in upregulation of Bax and correlates with potentiation of radiation induced cell kill.

BACKGROUND: Endometrial carcinoma is the most common gynecologic malignancy. Surgery has been the standard therapy for stage I and II endometrial carcinoma and radiation therapy either before or after surgery has been used to improve local control especially for high grade lesions. We have used Sodium Butyrate (BA) in order to examine whether endometrial carcinoma cells can be rendered more sensitive to radiation therapy. METHODS: Endometrial carcinoma cells in culture were pretreated with sodium butyrate and then irradiated. Clonogenic survival assay was used to determine percentage of surviving cells. Changes in Bax and Bcl-2 protein levels were determined by Western blot analyses. Effect of Bcl-2 overexpression on induction of Bax in response to butyrate pretreatment was studied in cells transfected with Bcl-2. RESULTS: A 24 h pretreatment of SKUT2 and Hec-1A cells with BA has an additive effect with radiation. Analysis of pro and anti-apoptotic protein levels revealed that the 24 h pretreatment with BA resulted in increased expression of the proapoptotic protein Bax which correlated with potentiation of radiation induced cell kill. Treatment of cells over expressing Bcl-2 with BA did not show induction of Bax suggesting that higher levels of Bcl-2 can block butyrate induced increase in levels of Bax. CONCLUSIONS: Use of BA at lower than toxic doses to upregulate the proapoptotic potential of cancer cells may be useful in an adjuvant or neoadjuvant setting but its success may depend upon the intrinsic Bcl-2 levels in the tumor.

Adenocarcinoma↗
PubMedDate not supplied

Interface between drug use and sex work in Manipur.

BACKGROUND: In India, drug use is seen predominantly as a problem among men. This study attempts to address the interface between drug use and sex work among women drug users in Manipur and the prevalence of HIV, hepatitis B and other sexually transmitted infections in them. METHODS: This cross-sectional survey was conducted between April and October 1997 at the time of an ethnic clash in imphal, the capital of Manipur. Sixty-nine women drug users were interviewed through street-based outreach workers; 38 women (55%) were injecting drug users. Data were generated with the help of a semi-structured questionnaire on sociodemography, drug use practice and health issues after obtaining informed consent from the participants. Subsequently, consent was also obtained from 60 respondents for collecting blood for unlinked anonymous tests for HIV and hepatitis B surface antigen. Clinical examination for reproductive tract infections, offered to all the study participants, generated data on sexually transmitted diseases. RESULTS: The prevalence of HIV infection in injecting drug users was 57% (20/35) compared to 20% (5/25) among non-injecting drug users (p = 0.001), although the prevalence of hepatitis B surface antigen was similar in the two groups, 48% v. 56%, respectively. Eighty per cent of the respondents, many of whom migrated following the ethnic clash, reported having sex with non-regular partners, two-thirds reported sex in exchange for money or drugs. Eighty-one per cent (29/36) of women who agreed to have a clinical examination had abnormal vaginal discharge, of which 10 had endocervical discharge. The presence of infection was confirmed in only 24% of those with vaginal discharge--4 had bacterial vaginosis and 3 trichomoniasis. CONCLUSION: Environmental interventions to reduce civil unrest and forced migration have an important role to play in HIV containment. The high rate of HIV infection, and the probability of a high rate of sexually transmitted infections in women drug users suggests that a targeted intervention in this population group is a public health need. An innovative outreach strategy should be designed for effective implementation of interventions among women injecting drug users and non-injecting drug users who operate from the streets as sex workers to support their drug habit as well as livelihood.

Adolescent↗
PubMedDate not supplied

Potential of the proteasomal inhibitor MG-132 as an anticancer agent, alone and in combination.

Proteasomal activity is required for normal cellular functions including cell division, where entry and exit from mitosis is strictly regulated by cyclins and cyclin-dependent kinases which are among the important substrates of the proteasomal degradative machinery. Inhibitors of proteasomal activity have been shown to be effective inducers of apoptosis in tumor cells and may be useful as anticancer agents, either alone or in combination with other drugs. We have examined the effect of MG-132, a dipeptide proteasomal inhibitor, on various human cancer cell lines. We have also examined the effect of MG-132 on normal CD34+ enriched primary human peripheral blood stem cells. Our results indicate that MG-312 is a potent anticancer agent with cytotoxic effects on a variety of human cancer cell lines irrespective of their p53 status. MG-132 was found to be more effective in combination with drugs such as doxorubicin and etoposide that act in the S/G2-phase of the cell cycle via a mechanism that involves stabilization of cyclin B1 and increased expression of Bax. Further, MG-132 inhibits CFU-GM colony formation of the CD34+ enriched PBSC population and this inhibition correlates with release of cyt C into the cytosol.

Antineoplastic Agents↗
PubMedDate not supplied

The treatment of pain following photorefractive keratectomy.

The most effective management of the pain that follows excimer laser photorefractive keratectomy (PRK) appears to be the use of topical nonsteroidal anti-inflammatory agents. A bandage contact lens for 2 days after photorefractive keratectomy is additive to pain relief. The helpfulness of patching was not confirmed. Surprisingly, drops of local anesthetic were not an efficacious means of managing the pain. This was possibly because they were not used frequently enough. The findings showed trends, but were not statistically significant.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

Purine salvage rescue by xanthine-guanine phosphoribosyltransferase (XGPRT) potentiates methotrexate resistance conferred by transfer of a mutated dihydrofolate reductase gene.

We have previously shown that successful gene transfer of a mutated dihydrofolate reductase (DHFR) cDNA confers resistance to methotrexate (MTX) upon infected cells. We constructed a retrovirus vector, DC/SV6S31GPT, which carries both the Escherichia coli xanthine-guanine phosphoribosyltransferase gene and the mutated Serine 31 DHFR gene. Mouse fibroblast NIH3T3 cells infected with DC/SV6S31 GPT are more resistant to MTX than cells infected with DC/SV6S31, which carries the Serine 31 DHFR and the neomycin resistance gene cDNA. The mechanism of this augmented resistance is the increased salvaging of purines due to expression of xanthine-guanine phosphoribosyltransferase, as the augmentation does not occur when dialyzed serum, containing little xanthine or guanine, is used for cytotoxicity assays. These results indicate that coexpression of a metabolically related gene can potentiate the resistance carried by a drug resistance gene. This vector may be useful in clinical gene therapy to protect bone marrow from the toxic effects of MTX.

3T3 Cells↗