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M Banerjee

Publications and source records attributed to M Banerjee.

At least 127 records · Page 7Linked to original sources
PubMed1987

GAL1-GAL10 divergent promoter region of Saccharomyces cerevisiae contains negative control elements in addition to functionally separate and possibly overlapping upstream activating sequences.

The upstream activating sequence (UASG) of the adjacent and divergently transcribed GAL1 and GAL10 promoters of Saccharomyces cerevisiae regulates the induction of the corresponding genes in response to the presence of galactose. We constructed chimeric yeast promoters in which a different UAS, UASC from the iso-1-cytochrome c (CYC1) gene of S. cerevisiae, was fused at different locations upstream of GAL1 (UASC-GAL1 promoters) or GAL10 (UASC-GAL10 promoters) and used to monitor the activity of UASG in cells grown in the presence or absence of galactose. Though the CYC1 promoter is fully induced in yeast grown in glycerol medium, UASC-GAL chimeric promoters containing UASG were repressed as much as 400-fold (UASC-GAL1) or 1350-fold (UASC-GAL10) in this growth medium. Several distinct portions of the GAL1-GAL10 divergent promoter region blocked the UASC-induced expression of the GAL1 and GAL10 promoters, whereas others did not, suggesting that several distinct negative control elements are present that may repress transcription of GAL1 and GAL10 in the absence of galactose. The approximate locations of these negative control elements were delimited to sites adjacent to or possibly overlapping the sites at which the positive control protein GAL4 binds in UASG. Deletion derivatives of GAL4 that fail to induce transcription from the wild-type GAL promoters but retain the DNA binding domain significantly derepressed the expression of the UASC-GAL chimeric promoters. These results, combined with those of earlier studies, suggest the possibility that GAL4 normally induces transcription of GAL1 and GAL10 by blocking the activity of these negative control elements, in addition to stimulating transcription by a mechanism of positive control.

Chromosome Mapping↗
PubMed1987

Involvement of heat shock proteins in bacteriophage Mu development.

Growth of bacteriophage Mu was severely inhibited at elevated temperature in mutants defective in the heat shock genes dnaK, groEL, and groES and in the rpoH (htpR) regulatory mutant, but not in mutants defective in the heat shock genes dnaJ or grpE; growth of a mutant of Mu deficient in functions encoded in the accessory region of the Mu genome was inhibited in the latter two host mutants. Phage production in the dnaJ mutant was restored by growth in low-salt medium. The stage in Mu development primarily affected in all except the groE mutants was phage late transcription. In contrast, the groE mutants did not support growth of Mu at any temperature; neither Mu DNA replication nor transcription was inhibited in these strains, suggesting that groE is required for phage morphogenesis as observed with several other coliphages.

Bacteriophage mu↗
PubMed1986

Differential responses of carcinogen-induced fibrosarcoma of mice to altered regimes of cold exposure.

The effect of chronic and intermittent cold exposure was studied in benzo(a)pyrene-induced fibrosarcoma of mice. Chronic exposure to 5 degrees C caused decrease in incidence, increase in latent period, and inhibition of tumor growth. Intermittent exposures to +5 degrees C and -10 degrees C induced significant enhancement of tumor growth which increased with the lowering of temperature. Concomitant with the tumor growth alterations, stress reactions assessed by plasma corticosterone levels, differed in these two regimes. The elevation of plasma corticosterone levels correlates with the tumor growth enhancement which is probably mediated by corticosterone-induced immuno-suppression. Inhibition of tumors appears to be a result of adaptation to chronic stress, or metabolic alterations in cold. Physiological alterations of the host, depending upon the nature and duration and severity of the "stress" exposure, determines in our opinion probably the course of neoplastic development.

Animals↗
PubMed1985

Mapping of the c-myc, pvt-1 and immunoglobulin kappa genes in relation to the mouse plasmacytoma-associated variant (6;15) translocation breakpoint.

A variant mouse plasmacytoma (MPC)-associated translocation chromosome has arisen by pericentric inversion and exchange of the distal segments of a Robertsonian 6;15 fusion chromosome in the CAK TEPC 1198 mouse plasmacytoma, as described earlier. In situ hybridization was performed on the normal and the inverted Rb chromosomes, using myc and kappa probes. On the normal Rb chromosome, myc was in the 15 D2/3 region, whereas kappa hybridized in the 6 C2 area, as expected. On the inverted Rb chromosome, myc remains on the centrometric side of the translocation breakpoint on the chromosome 15-derived portion, whereas kappa has moved to the chromosome 6-derived segment that joined the same breakpoint on the telomeric side. Taken together with our recent demonstration that the murine c-myc locus is oriented 'head up' on chromosome 15, and with the results of Cory and co-workers concerning the relationship between the kappa gene and the associated pvt-1 region in the CAK TEPC 1198 tumor, the following conclusions can be drawn: (i) in the variant translocation of the CAK TEPC 1198 MPC, the breakage occurs 3' of the c-myc gene, as in the human Burkitt lymphoma-associated variant translocations; (ii) the pvt-1 gene on chromosome 15 is distal to the myc gene; (iii) the kappa light chain locus is oriented 'head up' on mouse chromosome 6 and faces pvt-1 and, beyond it, c-myc, in a head-to-tail configuration.

Animals↗
PubMed1985

A new approach to gene mapping by in situ hybridization on isolated chromosomes.

A new technique was developed for in situ hybridization on isolated murine chromosomes. The safety and relative rapidity of the method is due to the ready availability of large numbers of isolated "target" chromosomes with well preserved morphology. Its applicability was demonstrated by mapping c-myc to band 15D of Robertsonian (6;15) fusion chromosomes. This localization coincides with the cytogenetic mapping of the translocation breakpoints in mouse plasmacytomas that carry the typical rcpt (12;15) translocation.

Animals↗
PubMed1978

Single dose therapy of giardiasis with tinidazole and metronidazole.

In random order, a single dose of either tinidazole or metronidazole, calculated as 50mg/kg body weight, was given to 100 children with symptomatic giardiasis. Follow-up was done for 16 days and consisted of 4 clinical, parasitological and biochemical assessments at intervals of 4 days. The actual mean dose of the drugs received by the patients was 55.5 mg/kg of tinidazole and 52.0mg/kg of metronidazole. Success, i.e. parasitic clearance and symptomatic relief, was achieved in 80% of patients given tinidazole as opposed to 36% of patients given metronidazole (p less than 0.01). Moreover, control of diarrhoea and negative stool conversion for G. lamblia occurred earlier with tinidazole than with metronidazole (p less than 0.01). The incidence of gastrointestinal side-effects was 12% for tinidazole and 4% for metronidazole. Neither drug caused any abnormality of the blood count, blood urea, urine analysis or liver function tests.

Child↗
PubMed1977

Single-dose treatment of giardiasis in children: a comparison of tinidazole and metronidazole.

One hundred children suffering from symptomatic giardiasis were treated with either tinidazole or metronidazole in random order. Both the drugs were given as a single oral dose calculated on the basis of 50 mg/kg body weight. Parasitological and clinical cure was obtained in 40 (80%) of 50 patients given tinidazole and in 18(36%) of 50 patients given metronidazole. This difference in cure rates was significant (p less than 0.01). Furthermore, control of diarrhoea and negative stool conversion for G. lamblia were achieved earlier with tinidazole than with metronidazole, the differences being significant (p less than 0.01) from the 8th post-treatment day. Gastro-intestinal side-effects of mild degree occurred in 6 patients on tinidazole and in 2 patients on metronidazole; they comprised nausea, vomiting, and bitter taste. Neither drug caused any abnormal deviation in blood counts or in biochemical tests of liver and kidney function.

Child, Preschool↗
PubMed1976

Uneven ventilation in smokers.

A body plethysmographic technique designed to detect small degrees of uneven ventilation in the lungs is presented. The technique is based on the same theoretical model as the frequency dependence of compliance. It has the advantage of requiring little time, no cooperation by the subject and no computation. Signs of uneven ventilation were found in 3 of the 42 normal controls, in 6 of 51 light smokers and in 66 of 103 heavy smokers. The data are compared with measurements of closing volume, of the slope of phase III of the single breath nitrogen washout and of maximal mid-expiratory flow rate.

Adult↗
PubMed1976

Blood of the common indian weaver birds Ploceus philippinus and Ploceus benghalensis (Linnaeus).

The blood contents of two common Indian weaver birds, Ploceus philippinus and Ploceus benghalensis have been studied. Morphology of RBC and WBC, total differential count, the number of RBC and WBC, Hb contents, PCV, MCV, MCH, MCHC, ESR, haemin crystal structures, coagulation and prothrombin time, glucose and cholesterol contents were calculated and compared with the haematological data recorded for other birds and vertebrates. Variation with respect to length and breadth of the erythrocytes and length of the nucleus of the RBC were also discussed. Males have higher RBC number and Hb content in these birds. The mean RBC number and Hb content were also more than in fishes, amphibians and reptiles but little less than in man. The RBC number for males of both the species do not differ significantly but the Hb contents in males and females of P. benghalensis differ significantly but this was not found in P. philippinus. Again the Hb content in male of both the species differ significantly but this was not true in females. Like Passer and Columba large number of polymorphs and lymphocytes were present but only a few basophils was observed in most of the slide preparations. No special type of haemin crystals were observed in any sex of both the species. The coagulation time was more than Passer and Columba but less than in man. There was also no marked difference in both the species with respect to prothrombin time. In both the species blood glucose was more in female than male but there was no marked difference in both the species.

Animals↗