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D Banerjee

Publications and source records attributed to D Banerjee.

At least 37 records · Page 2Linked to original sources
PubMed2002

Estimation of the rate of unrecognized cross-contamination with mycobacterium tuberculosis in London microbiology laboratories.

Isolates from patients with confirmed tuberculosis from London were collected over 2.5 years between 1995 and 1997. Restriction fragment length polymorphism (RFLP) analysis was performed by the international standard technique as part of a multicenter epidemiological study. A total of 2,779 samples representing 2,500 individual patients from 56 laboratories were examined. Analysis of these samples revealed a laboratory cross-contamination rate of between 0.54%, when only presumed cases of cross-contamination were considered, and 0.93%, when presumed and possible cases were counted. Previous studies suggest an extremely wide range of laboratory cross-contamination rates of between 0.1 and 65%. These data indicate that laboratory cross-contamination has not been a common problem in routine practice in the London area, but in several incidents patients did receive full courses of therapy that were probably unnecessary.

Bacterial Typing Techniques↗
PubMed2002

Study of primary amenorrhoea with special reference to cytogenetic evaluation.

An attempt has been made to find out the proportion of genetic causes in cases of primary amenorrhoea and to analyse different chromosomal pattern. Cases were analysed according to clinical profile, X-ray, laparoscopy/pneumography, hormone profile, USG, Gonadal Biopsy and Cytogenetic study including Sex Chromatin (Barr body) and Karyotyping. Among the 72 cases studied, the aetiological factors were Mullerian duct abnormalities in 27 cases (37.5%) Gonadal agenesis in 13 cases (18.05%). Turner stigmata in 18 cases (25%), Y cell line in 6 cases (8.33%). Delayed menarche in 4 cases (5.55%), systemic disease like Tuberculosis and Idiopathic 2 cases (2.77%) each. Chromosomal aberration was seen in 24 cases (33.33%) and it comes second most common cause of primary amenorrhoea after mullerian duct abnormalities.

Amenorrhea↗
PubMed2001

A randomized study of a flexible booster dosing regimen of VAQTA in adults: safety, tolerability, and immunogenicity.

BACKGROUND: VAQTA (hepatitis A vaccine inactivated, Merck & Co., Inc., West Point, PA) is licensed for use in healthy adults in a two-dose schedule at 0 and 6 months. OBJECTIVE: to determine whether the responses to a booster dose of VAQTA administered to adults 12 or 18 months after the first dose were similar to the response when the booster dose was administered 6 months after the first dose. METHODS: healthy adults were randomized to receive 50-U of VAQTA at 6 (Group I), 12 (Group II), or 18 months (Group III) following receipt of Dose 1 on Day 0. Blood samples were collected immediately prior to Doses 1 and 2 and then, 4 weeks following Dose 2. Seropositivity rates (SPRs), geometric mean titers (GMTs) in milli-international units per milliliter (mIU/ml) and booster response rates (BRRs) were compared among treatment groups. Safety data were collected on Vaccination Report Cards. RESULTS: no serious adverse experiences were reported, and the vaccine was well-tolerated by subjects in the three treatment groups. One month following the booster dose, SPRs and GMTs for Groups I, II, and III, respectively, were, 100% (102/102) and 6726.4 mIU/ml; 97.9% (93/95) and 4863.8 mIU/ml; 100% (86/86) and 6068.3 mIU/ml. The BRRs were 88.2% (Group I), 90.2% (Group II) and 94.2% (Group III). CONCLUSION: responses to the booster dose were comparable regardless of the timing (i.e. 6, 12, or 18 months following Dose 1). Flexibility in the timing of the booster dose of VAQTA in adults would allow the vaccination schedule to be the same for adults, adolescents, and children and may increase the likelihood that adults receive the booster dose.

Adult↗
PubMed2001

Colorimetric assay method for determination of the tannin acyl hydrolase (EC 3.1.1.20) activity.

A new colorimetric method of tannase (tannin acyl hydrolase, EC 3.1.1.20) assay has been developed using its specific substrate tannic acid. It is based on the changes in optical density of substrate tannic acid after enzymatic reaction at 530 nm. The residual tannic acid was measured by a modified BSA precipitation method. This assay is very simple, reproducible, and very convenient, and with it tannase activity can be measured in relation to the growth of the organism.

Carboxylic Ester Hydrolases↗
PubMed2001

Metallothionein expression in patients with small cell carcinoma of the lung: correlation with other molecular markers and clinical outcome.

BACKGROUND: Patients with small cell carcinoma of the lung (SCLC) are known to have an extremely poor prognosis, with a 5-year survivor rate of only 5%. Chemotherapeutic drug resistance is a major obstacle to curative therapy in patients with SCLC. METHODS: The authors evaluated retrospectively the expression of metallothionen (MT), proliferating cell nuclear antigen (PCNA), p53, and retinoblastoma gene product (RBGP) in biopsy samples from 58 patients with SCLC prior to standard chemotherapy. The objective was to study the correlation between MT and other molecular markers in SCLC and correlate these data with the clinical outcome of patients. The authors studied 28 short-term survivors (STS; survival < 24 months) and 30 long-term survivors (LTS; survival > 24 months). RESULTS: In line with expectations, the authors found a strong inverse association between stage and survival. Of 58 patients with SCLC, 26 patients (45%; 17 STS and 9 LTS) showed MT expression, 55 patients (94%; 28 STS and 27 LTS) were positive for PCNA, 28 patients (48%; 16 STS and 12 LTS) were positive for p53, and only 6 patients (10%; 1 STS and 5 LTS) showed positivity for RBGP. On comparing the percent positivity of various markers in the two survivor groups, there was greater frequency of expression of MT, PCNA, and p53 and lower RBGP expression in the STS group compared with the LTS group. However, only the difference in expression of MT between the two survivor groups was statistically significant (Fisher exact test; P = 0.034). Multivariable analysis using a logistic regression model showed a significant association between MT expression and patient survival after adjusting for disease stage (chi-square test; P = 0.022). There was also a statistically significant association between MT expression and p53 expression (chi-square test; P = 0.001). CONCLUSIONS: In this study, of the molecular markers studied, the authors demonstrated that only MT overexpression was independently predictive of short-term survival in patients with SCLC undergoing chemotherapy.

Adult↗
PubMed2001

Effects of overexpression of gamma-Glutamyl hydrolase on methotrexate metabolism and resistance.

Intracellular metabolism of methotrexate (MTX) to MTX-polyglutamates (MTXPG) is one determinant of cytotoxicity. Steady-state accumulation of MTXPG seems to depend on the activity of two enzymes: folylpolyglutamate synthetase (FPGS), which adds glutamate residues, and gamma-glutamyl hydrolase (GGH), which removes them. Overexpression of GGH would be expected to decrease intracellular MTXPG, thereby increasing efflux of MTX and decreasing cytotoxicity. Increased expression of GGH has been shown to be associated with resistance to MTX in human sarcoma cell lines and a rat hepatoma cell line. To clarify the specific role of GGH in determining MTX sensitivity, we investigated the phenotype produced by forced GGH overexpression in two cell types. Furthermore, because MTX and folic acid share metabolic pathways, we measured the effects of GGH overexpression on folic acid metabolism. The full-length cDNA for GGH, subcloned into a constitutive expression vector, was transfected into a human fibrosarcoma (HT-1080) and a human breast carcinoma (MCF-7) cell line. Compared with the clones containing an empty vector, the GGH-overexpressing cells express 15- to 30-fold more GGH mRNA, more GGH protein, and 15- to 90-fold more GGH enzyme activity. GGH overexpression altered MTX accumulation and metabolism to long-chain polyglutamates. In contrast to expectations, however, GGH overexpression did not confer resistance to short MTX exposures in either cell line. Changes in MTX metabolism were found to be balanced by alterations in accumulation and metabolism of folic acid. The ratio of MTX:folate accumulation may be a better predictor of MTX cytotoxicity than the accumulation of either alone. We conclude that, at least for these two cell lines, GGH overexpression alone is insufficient to produce clinical resistance to MTX.

Antimetabolites, Antineoplastic↗
PubMed2001

Cloning and structural characterization of ECTACC, a new member of the transforming acidic coiled coil (TACC) gene family: cDNA sequence and expression analysis in human microvascular endothelial cells.

Erythropoietin (Epo) transduces mitogenic and chemoattractant signals to human endothelial cells. Identifications of Epo-responsive genes are important for understanding the molecular nature of Epo signaling in endothelial cells. The effects of Epo on differential expression of various genes were examined in human microvascular endothelial cells (HMVEC) by differential display reverse transcriptase polymerase chain reaction (RT-PCR). In the current study we obtained from Epo-treated HMVEC a cDNA fragment with characteristics of the 3' end of mRNA. Using the cDNA fragment, we then selectively isolated a full-length clone by screening an unamplified endothelial cell cDNA library followed by 5' rapid amplification of cDNA ends by polymerase chain reaction (RACE-PCR). The nucleotide sequence of the longest cDNA revealed an open reading frame of 3311 nucleotides that encodes a protein consisting of approximately 906 amino acids with a predicted MW of approximately 100 kDa. The nucleotide sequence of the cDNA is nearly identical to that of transforming acidic coiled coil-containing (TACC2) and anti-zuai-1 (AZU-1) cDNA clones except at the 5'- and 3'-ends. Northern blot analysis showed an increase in endothelial-TACC-related mRNA levels in Epo-treated cells in comparison to that of the control cells. Endothelial-TACC-related mRNA was highly expressed in heart and skeletal muscle tissue. Placenta and brain tissue exhibited low levels of expression of endothelial-TACC-related gene. Southern blot analysis of genomic DNA from somatic cell hybrids showed that endothelial-TACC-related cDNA maps to chromosome 10. Immunofluorescence microscopy and the occurrence of several putative phosphorylation and SH3 binding sites on the deduced protein suggest that endothelial-TACC-related protein may be involved in Epo signaling cascades in endothelial cells.

Amino Acid Sequence↗
PubMed2001

Randomized, double-blind study in healthy adults to assess the boosting effect of Vaqta or Havrix after a single dose of Havrix.

A randomized, double-blind, multicenter study was conducted to investigate the boosting effect of Vaqta or Havrix in 537 healthy adults 18-53 years of age who had received a single dose of Havrix either 24 or 52 weeks earlier. Subjects were randomized in a 2 : 1 ratio to receive either Vaqta or Havrix for their second dose of vaccine and followed for clinical reactions for 14 days after dose 2 was administered. Serum samples were collected immediately before dose 2 was administered and again 4 weeks later and evaluated for hepatitis A antibody (modified hepatitis A virus antibody assay). The booster response rate after administration of the second dose of either vaccine was similar (86.1% for Vaqta vs. 80.1% for Havrix). The geometric mean titers were also similar: 3274 mIU/mL (95% confidence interval [CI], 2776-3858) for Vaqta versus 2423 mIU/mL (95% CI, 1911-3074) for Havrix. The proportion of subjects who reported > or =1 injection-site adverse experiences was lower in the patients receiving Vaqta than in those receiving Havrix (36.6% vs. 59.7%; P<.001). The results of this study indicate that a regimen of Havrix followed by Vaqta is generally well tolerated and highly immunogenic.

Adolescent↗
PubMed2001

Production and characterization of extracellular and intracellular tannase from newly isolated Aspergillus aculeatus DBF 9.

A comparative study on the simultaneous production of extra and intracellular tannase was made from newly isolated fungal strain Aspergillus aculeatus DBF 9. This strain produced five times more intracellular enzyme within 24 h in liquid culture than the extracellular form. Maximum tannase production occurred in the culture broth containing 1-2% (w/v) tannic acid and 0.05-0.1% (w/v) glucose. The pH and temperature optima of both the enzymes were found at 5.0 and 50-60 degrees C, respectively. Extra and intracellular tannase showed good stability at higher temperature, pH values and salt (NaCl) concentration. These properties make the enzyme suitable for pollution control and bioprocess industry.

Aspergillus↗
PubMed2001

Generation of dual resistance to 4-hydroperoxycyclophosphamide and methotrexate by retroviral transfer of the human aldehyde dehydrogenase class 1 gene and a mutated dihydrofolate reductase gene.

The genetic transfer of drug resistance to hematopoietic cells is an attractive approach to overcoming myelosuppression caused by high-dose chemotherapy. Because cyclophosphamide (CTX) and methotrexate (MTX) are commonly used non-cross-resistant drugs, generation of dual drug resistance in hematopoietic cells that allows dose intensification may increase anti-tumor effects and circumvent the emergence of drug-resistant tumors. We constructed a retroviral vector containing both a human cytosolic ALDH-1 cDNA and a human doubly mutated DHFR cDNA (Phe22/Ser31; termed F/S in the description of constructs) to generate increased resistance to both CTX and MTX. Infection of NIH3T3 cells resulted in increased resistance to both 4-hydroperoxycyclophosphamide (4HC) (1.9 +/- 0.1-fold) and MTX (73 +/- 2.8-fold). Transduced human CD34(+) enriched hematopoietic progenitor cells were also resistant to both 4HC and MTX by CFU-GM readout. Lethally irradiated mice transplanted with SFG-ALDH-IRES-F/S or mock-transduced bone marrow cells were treated with high-dose pulse CTX or high-dose CTX/MTX. Animals receiving marrow not transduced with ALDH-1 or mutated DHFR cDNA died from CTX or CTX/MTX toxicity, whereas mice transduced with ALDH-1 and mutated DHFR cDNA-containing marrow were able to tolerate the same doses of CTX or CTX/MTX treatment posttransplant. These data taken together indicate that ALDH-1 overexpression and mutant DHFR increased both 4HC and MTX resistance in vitro and in the in vivo mouse model. This construct may be useful for protecting patients from high-dose CTX- and MTX-induced myelosuppression.

3T3 Cells↗
PubMed2001

Uncommon presentation of medulloblastoma.

INTRODUCTION: Medulloblastoma commonly occurs in children as a midline posterior fossa mass arising from the vermis, which appears as a hyperdense, homogeneously enhancing mass on CT scan and is associated with the clinical profile of posterior fossa syndrome. This unique clinico-radiological pattern is considered 'typical', but then medulloblastomas do not follow the typical clinico-radiological pattern in a significant number of cases. PATIENTS: Out of the 42 cases of medulloblastoma operated on at SGPGIMS from 1988 to 1998, 29 cases were retrospectively and 13 cases were prospectively studied to detect the atypical clinico-radiological features. The typical radiological feature of a hyperdense homogeneously enhancing mass was seen in only 23 of the 42 patients, while 5 patients had hypodense nonenhancing masses, 13 had cystic changes, and 6 patients had calcifications in their tumours. Three patients presented with tumours in a very unusual location, i.e. the cerebellopontine angle cistern. RESULTS: During follow-up, which ranged from a minimum period of 1 year to a maximum of 9 years, patients came back with metastases at very unusual sites. There were 5 cases of metastases in the frontal and subfrontal area (developed between 5 months and 5 years following surgery), and 1 patient developed a cervical intramedullary metastasis. Two patients developed abdominal metastases and ascites 2 years after definitive surgery and ventriculo-peritoneal shunting. Each of these 2 patients, however, had received a full course of craniospinal irradiation following surgery. Thus, we had a number of cases with an unusual clinical, radiological and metastatic pattern.

Cerebellar Neoplasms↗
PubMed2001

Retroviral transduction of human dihydropyrimidine dehydrogenase cDNA confers resistance to 5-fluorouracil in murine hematopoietic progenitor cells and human CD34+-enriched peripheral blood progenitor cells.

Severe 5-fluorouracil (5-FU) toxicity has been reported among patients lacking dihydropyrimidine dehydrogenase (DPD) enzymatic activity. DPD is the principal enzyme involved in the degradation of 5-FU to 5'-6'-dihydrofluorouracil, which is further metabolized to fluoro-beta-alanine. We demonstrate here that overexpression of human DPD confers resistance to 5-FU in NIH3T3 cells, mouse bone marrow cells, and in human CD34+-enriched hematopoietic progenitor cells. An SFG-based dicistronic retroviral vector containing human DPD cDNA, an internal ribosomal entry site (IRES), and the neomycin phosphotransferase (Neo) gene was constructed (SFG-DPD-IRES-Neo). Transduced NIH3T3 cells demonstrated a 2-fold (ED50) increase in resistance to a 4-hour exposure of 5-FU in comparison to nontransduced cells. Expression of DPD was confirmed by Northern and Western blot analyses, and DPD enzyme activity was detectable only in transduced cells. Infection of mouse bone marrow cells with this retroviral construct resulted in an increased number of 5-FU-resistant CFU-GM colonies, compared to mock-transduced bone marrow in both 4-hour and 12- to 14-day exposures. Infection of human CD34+-enriched cells with this construct and incubation with 5-FU (10(-6) M) for 14 days also resulted in an increased number of 5-FU-resistant colonies. Retroviral transduction of human hematopoietic progenitor cells with a cDNA-expressing human DPD conferred resistance to 5-FU in NIH3T3 cells, mouse bone marrow cells, and human CD34+-enriched cells. These results encourage the use of this gene as a method to protect patients from 5-FU myelotoxicity.

3T3 Cells↗
PubMed2001

The leucine-rich repeat domain can determine effective interaction between RPS2 and other host factors in arabidopsis RPS2-mediated disease resistance.

Like many other plant disease resistance genes, Arabidopsis thaliana RPS2 encodes a product with nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains. This study explored the hypothesized interaction of RPS2 with other host factors that may be required for perception of Pseudomonas syringae pathogens that express avrRpt2 and/or for the subsequent induction of plant defense responses. Crosses between Arabidopsis ecotypes Col-0 (resistant) and Po-1 (susceptible) revealed segregation of more than one gene that controls resistance to P. syringae that express avrRpt2. Many F(2) and F(3) progeny exhibited intermediate resistance phenotypes. In addition to RPS2, at least one additional genetic interval associated with this defense response was identified and mapped using quantitative genetic methods. Further genetic and molecular genetic complementation experiments with cloned RPS2 alleles revealed that the Po-1 allele of RPS2 can function in a Col-0 genetic background, but not in a Po-1 background. The other resistance-determining genes of Po-1 can function, however, as they successfully conferred resistance in combination with the Col-0 allele of RPS2. Domain-swap experiments revealed that in RPS2, a polymorphism at six amino acids in the LRR region is responsible for this allele-specific ability to function with other host factors.

Alleles↗
PubMed2001

Concentrations of gatifloxacin in plasma and pulmonary compartments following a single 400 mg oral dose in patients undergoing fibre-optic bronchoscopy.

The concentrations of gatifloxacin achieved after a single 400 mg oral dose were measured in plasma, epithelial lining fluid (ELF), alveolar macrophages (AMs) and bronchial mucosa (BM) using a microbiological assay. Fourteen patients undergoing fibre-optic bronchoscopy were studied. Mean plasma, ELF, AMs and BM concentrations, respectively, at 2, 4 and 12 h were as follows: 2 h: 3.96 mg/L, 6.00 mg/L, 69.10 mg/L, 6.24 mg/kg; 4 h: 3.22 mg/L, 6.16 mg/L, 77.32 mg/L, 5.32 mg/kg; 12 h: 1.74 mg/L, 2.98 mg/L, 61.95 mg/L, 3.00 mg/kg. These concentrations exceed the MIC(90)s for common respiratory pathogens such as Streptococcus pneumoniae (0.5 mg/L), Haemophilus influenzae (0.013 mg/L), Moraxella catarrhalis (0.05 mg/L), Chlamydia pneumoniae (0.125 mg/L) and Mycoplasma pneumoniae (0.06 mg/L).

Administration, Oral↗
PubMed2001

Fragile X syndrome in Calcutta, India.

Fragile-X-linked mental retardation usually results from amplification of the CGG repeat in the 5' untranslated region of the FMR1 gene. To assess the extent of variation of the CGG repeat in the population from the eastern region of India we studied 98 mentally retarded individuals living in and around Calcutta and identified 21 distinct alleles ranging in size from 8 to 44 CGG repeats. A repeat size of 28 was the most frequent; this value is different from the most frequent repeat size found in other studies, indicating a racial or ethnic variation. Patients with the clinical features of the syndrome have been found to carry expanded CGG repeats. Thus, it can be inferred that the expansion of CGG repeats may be a frequent cause of the syndrome in our population.

Adolescent↗