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Biomedical subjects

D Banerjee

Publications and source records attributed to D Banerjee.

At least 163 records · Page 9Linked to original sources
PubMed1994

Molecular detection and characterization of clonal cell populations in acute lymphocytic leukemia by analysis of conformational polymorphisms of cRNA molecules of rearranged T-cell-receptor-gamma and immunoglobulin heavy-chain genes.

Junctional regions of rearranged T-cell-receptor-gamma (TCR) and immunoglobulin heavy-chain (IgH) genes represent an idiotypic DNA sequence for an individual lymphocytic cell, and any clone or clonal disease developing from this cell. In this study, a novel methodology for detection and characterization of clone specific DNA sequences in patients with acute lymphocytic leukemia (ALL) was developed. Junctional regions of rearranged TCR-gamma IgH genes in specimens of bone marrow aspirates of patients with ALL (precursor-B-ALL ten, T-ALL two, null-ALL one; ALL not classified one), of a patient with lymphoid blast crisis of chronic myeloid leukemia, of a B-cell chronic lymphocytic leukemia, and in DNA from peripheral blood mononuclear cells of ten healthy volunteers were amplified by polymerase chain reaction (PCR). The PCR products were transcribed into complementary RNA (cRNA). Conformational polymorphisms of cRNA molecules were analyzed by non-denaturing polyacrylamide gel electrophoresis. A specific cRNA banding pattern for rearranged TCR-gamma or IgH genes was observed in all patients with lymphocytic leukemia. In contrast, analysis of DNA from healthy volunteers yielded a smear of confluent polymorphisms representing multiple different cRNA molecules. In two patients with precursor-B-ALL, cRNA banding patterns of junctional regions of rearranged TCR-gamma genes were analyzed in sequential bone marrow aspirates. The banding patterns disappeared after chemotherapy and achievement of blast clearance. This novel and rapid molecular assay offers several advantages as compared to Southern blot analyses and previous PCR based methodologies for the detection of clonal lymphocytic populations. With this methodology, studies on the clonal evolution of lymphoproliferative disorders (e.g. the prognostic significance of the emergence of additional clones) can be performed more easily than with any other traditional molecular method.

B-Lymphocytes↗
PubMed1993

Transcriptional regulation of the gene encoding apolipoprotein AI in chicken LMH cells.

Previous studies indicated that the differential expression of the chicken gene (ApoAI) encoding apolipoprotein AI (ApoAI) in the QMLA-29 and LMH cell lines may be the result of altered cis-elements and/or trans-acting factors. To examine the cis-elements, LMH DNA was used as a template and the 5'-upstream region of ApoAI was PCR amplified. The nucleotide sequence of the LMH ApoAI upstream region was identical to that obtained from young chicken liver DNA. Band shift analyses of the -87 to +90 bp upstream DNA of ApoAI showed differences in the shifting patterns when nuclear proteins from LMH and liver cells were used. Southwestern blots with the same DNA fragment and nuclear proteins from liver and LMH also showed differences. There was one common band of approx. 65 kDa. In addition, LMH had a trans-acting factor of approx. 26 kDa, while liver had an approx. 46-kDa protein. These data suggest that LMH has a different trans-acting factor which may downregulate ApoAI expression.

Animals↗
PubMed1993

Metallothionein in testicular germ cell tumors and drug resistance. Clinical correlation.

BACKGROUND: Metallothioneins (MT) are endogenous metalloproteins involved in the homeostasis of essential metals and detoxification of toxic metals. Some recent experimental studies suggested tumor resistance to cisdiamminedichloroplatin may be associated with overexpression of MT in the tumor. METHODS: The presence of MT in 33 primary testicular germ cell tumor specimens was assessed immunohistochemically using a rabbit polyclonal rat liver MT antibody that cross-reacted with human MT. The data were correlated with the patients' clinical course. RESULTS: Seminomas stained weakly or not at all for MT, regardless of the clinical stage. Most nonseminomas stained heavily for MT. The more advanced staged nonseminomas tended to stain more heavily for MT. CONCLUSIONS: In view of the considerable experimental evidence as well as some inferential clinical data involving MT in cis-diamminedichloroplatin resistance, there appears to be a role for MT in cis-diamminedichloroplatin resistance in germ cell tumors. Further studies to elucidate the role of MT in germ cell tumor chemoresistance are warranted.

Cisplatin↗
PubMed1993

Problems with the "dural tail" sign.

Prominent enhancement of the dura mater, the "dural tail" adjacent to a peripherally located mass on gadolinium-enhanced MRI has been described as being characteristic of meningiomas. We present a cerebral glioma showing the classical "dural tail".

Brain↗
PubMed1993

Sustained indomethacin and ranitidine with intermittent continuous infusion interleukin-2 in advanced malignant melanoma: a phase II study.

Experimental work has shown that, during the development of tumours, host macrophages are triggered to produce high levels of prostaglandin E2 which inactivates natural killer cells and suppresses lymphokine activated killer cell development. Sustained, uninterrupted indomethacin treatment, when combined with interleukin-2 (IL-2), can totally eradicate experimental metastases. Most trials utilizing high dose IL-2 employ indomethacin and ranitidine in order to alleviate or prevent IL-2 toxicity, but only administer these medications concurrently with IL-2 therapy. A Phase II trial was conducted in patients with advanced melanoma. Patients received 50-75 mg indomethacin three times daily and 150 mg ranitidine twice daily, starting at least 1 week prior to IL-2 and continuing until intolerance or disease progression. Continuous venous infusion IL-2 was administered for three courses, each consisting of 5 days of treatment at 18 x 10(6) iu/m2/day for the first course with escalation of dose for the subsequent courses if toxicity allowed. Twenty-one patients were eligible to receive all components of therapy. Three patients achieved an objective response (one complete and two partial), giving a response rate of 14%. However, two of these objective responses (one complete and one partial) were achieved on indomethacin and ranitidine alone, prior to the commencement of IL-2 therapy. In this study, indomethacin and ranitidine, without IL-2, have been shown to have antitumour activity in advanced melanoma; continuous infusion IL-2 appeared to add little to the response seen with these two agents.

Adult↗
PubMed1993

Sustained oral indomethacin and ranitidine with intermittent continuous infusion interleukin-2 in advanced renal cell carcinoma.

Experimental work in murine models has shown that, during the development of tumors, prostaglandin E2 produced by host macrophages inactivates natural killer cells and suppresses lymphokine-activated killer (LAK) cell development. Chronic indomethacin therapy when combined with interleukin-2 (IL-2) can totally eradicate experimental lung metastases in these models. A phase II trial was performed to study the clinical efficacy of chronic indomethacin and intermittent IL-2 therapy in patients with advanced renal cell carcinoma. Patients were placed on indomethacin and ranitidine orally at least one week prior to commencing therapy with IL-2. IL-2 was given by continuous infusion for three courses, each consisting of 5 days of treatment with 6 days of rest. Initial dose of IL-2 was 18.0 x 10(6) IU/m2/day for the first course with escalation to 27.0 x 10(6) IU/m2/day for the second and 36.0 x 10(6) IU/m2/day for the third course, if toxicity allowed. Patients were admitted to a general oncology ward for therapy with IL-2, and vasopressor agents were not used. Thirty-two patients were eligible, with 7 patients withdrawing early from the study. Twenty-five patients went on to receive at least one course of IL-2. Two complete and three partial responses were seen for an objective response rate of 5/25 (20%) for eligible and treated patients or 5/32 (16%) for all patients entered onto the study, regardless of treatment status. The response rate to this regimen is comparable with other high dose IL-2 regimens in renal cell carcinoma, including those employing adoptive therapy with lymphokine-activated killer cells.

Carcinoma, Renal Cell↗
PubMed1993

Characterization of the chicken apolipoprotein A-I gene 5'-flanking region.

Apolipoprotein A-I (apoA-I) is a major protein component of plasma high-density lipoprotein in all species studied, and plays an important role in cholesterol homeostasis. In an earlier study, we cloned and structurally characterized the chicken apoA-I gene. In this study, the 5'-flanking region of the chicken apoA-I gene was sequenced and functionally characterized. Sequence analysis of the 510-nucleotide 5' upstream region revealed the presence of TATA and CCAAT boxes. In addition, we identified binding sites for several transcription factors such as Sp1, AP1, and NFI.2. When the 5' fragment was ligated into a promoterless CAT vector and transfected into a chicken hepatocarcinoma cell line (LMH), the bacterial chloramphenicol acetyl transferase (CAT) gene was expressed, suggesting transcriptional regulation is associated with this region. Transfection studies with other 5' deletion constructs revealed that the sequence spanning the region -82 to +87 contained the major transcriptional activity. DNase I footprinting, gel retardation, and Southwestern blot analyses showed that the fragment interacts with nuclear proteins.

Animals↗
PubMed1993

Gastroduodenal tuberculosis.

Nine patients with gastroduodenal tuberculosis (GDTB) were seen over a period of 2 years at a tertiary level referral institute. Clinical presentation of GDTB is similar to that of peptic ulcer disease. Endoscopic biopsy and/or laparotomy and biopsy establish the diagnosis. Medical treatment is the mainstay of therapy, although surgical intervention may be required for the management of complications. Gastroduodenal tuberculosis should be suspected in patients, residing in areas where the disease is endemic, with a short history suggestive of peptic ulcer disease and an early onset of gastric outlet obstruction.

Adult↗
PubMed1993

Prognosis and management of membraneous nephropathy.

Patients of idiopathic membranous nephropathy (MGN) were randomly assigned to received steroid and cyclophosphamide every other month (Gr-I) and steroid alone (Gr-II). Of 36 patients in Gr.I, 33 patients achieved complete remissions, 2 had relapsing course with remission on further courses of therapy and only one has reached end stage renal failure. In contrast, of the 35 patients in Gr. II, 15 (P < 0.001) achieved complete remission, 7 are in partial remission, 5 have no response, another 5 have deterioration of renal function of which two required dialysis, and 3 have relapsing course after the initial remission. Mean follow up period was 46 +/- 10.2 months. We conclude that steroid and cyclophosphamide every other month is highly effective in achieving remission in patients with membranous nephropathy.

Adolescent↗
PubMed1993

Acute diarrhoea caused by Vibrio mimicus in Calcutta.

Out of 539 acute diarrhoea cases studied, Vibrio mimicus was isolated as a sole pathogen in the faeces of 7 (1.3%) cases. The chief clinical presentations of the seven cases were watery diarrhoea and vomiting. Bloody diarrhoea was observed in 2 (28.5%), abdominal pain in 2 (28.57%) and fever in one (14.29) cases. All cases could be effectively treated with ORS except 3 (42.85%) cases who required IV Ringer's lactate. All V. mimicus strains isolated in the study were uniformly susceptible to tetracycline, chloramphenicol, norfloxacin and ciprofloxacin.

Acute Disease↗
PubMed1993

Mutations leading to antifolate resistance in Chinese hamster ovary cells after exposure to the alkylating agent ethylmethanesulfonate.

Chinese hamster ovary cells with a single allele for dihydrofolate reductase were used as a model system to study the effect of exposure to an alkylating agent, ethylmethanesulfonate, on rates and types of mutations at the dihydrofolate reductase locus leading to antifolate resistance. After overnight exposure to 400 micrograms/ml ethylmethanesulfonate, cells were allowed to recover for 3 days, and resistant colonies were selected in 8 x 10(-8) M trimetrexate. Trimetrexate, rather than methotrexate, was used as the selecting agent to increase the probability of obtaining mutations in dihydrofolate reductase, rather than in the reduced folate transport carrier protein. Seven of several hundred surviving colonies were selected at random, and cell lines were established. Cell lines 1-3 were maintained in culture in the presence of 8 x 10(-8) M trimetrexate and were 66-170-fold resistant to the drug. Cell lines 4-7 were initially expanded in 8 x 10(-8) M trimetrexate but were then maintained in the absence of the drug. These cell lines were 4.4-26-fold resistant to the drug, compared with the parental cell line. Cell line 1 was found to have an increase in dihydrofolate reductase activity, a corresponding increase in mRNA for dihydrofolate reductase, and amplification of this gene. Cell lines 2 and 6 had a mutated dihydrofolate reductase with altered trimetrexate- and methotrexate-binding properties. Cell line 3 had a 3-fold increase in dihydrofolate reductase activity. In cell lines 4, 5, and 7 the mechanisms of resistance to trimetrexate remain unknown.

Alkylating Agents↗
PubMed1992

Assembly and secretion of fibrinogen. Degradation of individual chains.

Hep G2 cells produce surplus A alpha and gamma fibrinogen chains. These excess chains, which are not secreted, exist primarily as free gamma chains and as an A alpha-gamma complex. We have determined the intracellular location and the degradative fate of these polypeptides by treatment with endoglycosidase-H and by inhibiting lysosomal enzyme activity, using NH4Cl, chloroquine, and leupeptin. Free gamma chain and the gamma component of A alpha-gamma are both cleaved by endoglycosidase-H, indicating that the gamma chains accumulate in a pre-Golgi compartment. Lysosomal enzyme inhibitors did not affect the disappearance of free gamma chains but inhibited A alpha-gamma by 50%, suggesting that A alpha-gamma is degraded in lysosomes. The degradative fate of individual chains was determined in transfected COS cells which express but do not secrete single chains. Leupeptin did not affect B beta chain degradation, had very little affect on gamma chain, but markedly inhibited A alpha chain degradation. Antibody to immunoglobulin heavy chain-binding protein (GRP 78) co-immunoprecipitated B beta but not A alpha or gamma chains. Preferential binding of heavy chain-binding protein to B beta was also noted in Hep G2 cells and in chicken hepatocytes. Taken together these studies indicate that B beta and gamma chains are degraded in the endoplasmic reticulum, but only B beta is bound to BiP. By contrast A alpha chains and the A alpha-gamma complex undergo lysosomal degradation.

Ammonium Chloride↗
PubMed1992

Effect of indomethacin plus ranitidine in advanced melanoma patients on high-dose interleukin-2.

Preclinical models of advanced melanoma have shown that chronic indomethacin therapy combined with interleukin 2 (IL-2) can eradicate experimental metastases. A phase II trial was done in patients with advanced melanoma. Indomethacin and ranitidine were begun at least one week before IL-2. Of the objective responses in 3 patients, 2 were achieved on ranitidine and indomethacin alone, before start of IL-2. Indomethacin and ranitidine may be responsible for some responses in melanoma patients previously attributed to IL-2.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Biosynthesis of lipoprotein: location of nascent apoAI and apoB in the rough endoplasmic reticulum of chicken hepatocytes.

Our previous studies showed that in hepatic RER of young chickens, nascent apoAI is not associated with lipoprotein particles and only becomes part of these lipoprotein structures in the Golgi. In this study, we have used three different methodologies to determine the locations of apoAI and apoB in the RER and compared them to that of albumin. Immunoelectron microscopic examination of the RER cell fractions showed that both apoAI and apoB were associated only with the RER membrane whereas albumin was located both within the lumen and on the limiting membrane of the vesicles. To examine the possibility of membrane integration of nascent apoAI and apoB in the RER, we administered L-[3H]leucine to young chickens for 10 min, isolated RER, treated this cell fraction with buffers of varying pH, and measured the release of radioactive albumin, apoAI, and apoB. The majority of nascent apoAI (64%), nascent apoB (100%), and nascent albumin (97%) was released from RER vesicles at pH 11.2, suggesting that, like albumin, apolipoproteins are not integrated within the membrane. To determine if nascent apoproteins are exposed to the cytoplasmic surface, we administered L-[3H]leucine to young chickens and at various times isolated RER and Golgi cell fractions. Radioactive RER and Golgi cell fractions were treated with exogenous protease and the percent of nascent apoAI and apoB accessible to proteolysis was determined and compared to that of albumin. At 5, 10, and 20 min of labeling, 35-56% of nascent apoAI and 60-75% of apoB in RER were degraded, while albumin was refractive to this treatment. At all times both apolipoproteins and albumin present in Golgi cell fractions were protected from proteolysis. These biochemical and morphological findings indicate that apoAI and apoB are associated with the rough microsomal membrane and are partially exposed to the cytoplasmic surface at early stages of secretion. They may later enter the luminal side of the ER and, on entering the Golgi, form lipoprotein particles.

Albumins↗
PubMed1992

Comparison of the expression of a mutant dihydrofolate reductase under control of different internal promoters in retroviral vectors.

To determine the effect of different promoters on the expression of an altered dihydrofolate reductase (DHFR) gene conferring methotrexate (MTX) resistance in different cell types, double-copy retroviral vectors were constructed carrying a murine mutant DHFR under the control of five different promoters, i.e., human adenosine deaminase (ADA), simian virus 40 (SV40), thymidine kinase (TK), human beta-actin, and cytomegalovirus (CMV). Their expression was compared in NIH-3T3 cells, three human leukemia cell lines, and mouse bone marrow. The variant DHFR is readily expressed from these various promoters in retroviral vectors at a selectable level. In 3T3 cells, the DHFR constructs containing the SV40 promoter conferred the highest levels of resistance to MTX. In K562 and Raji cells, the construct with the TK promoter produced the highest level of resistance. However granulocyte-macrophage colony-forming unit (CFU-GM) colonies from mouse marrow were more resistant to MTX when infected with vectors containing the SV40 promoter and ADA promoter as compared to the other promoter constructs. These studies show that mouse fibroblast cell lines such as NIH-3T3 do not predict the effectiveness of retroviral-mediated gene transfer for marrow progenitor cells, and that the activity of retroviral vector-encoded promoters vary in an unpredictable manner from cell type to cell type. Possible implications for basic gene transfer studies and clinical applications are discussed.

3T3 Cells↗