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Biomedical subjects

R Ganguly

Publications and source records attributed to R Ganguly.

At least 37 records · Page 2Linked to original sources
PubMed1993

Parathyroid adenoma in northern Nigeria.

A middle-aged farmer and a female student presented with osteitis fibrosa cystica with nephrocalcinosis in the former and nephrolithiasis in the latter due to primary hyperparathyroidism. Hypercalcaemia was present in both cases and neck exploration revealed a large solitary parathyroid adenoma which was excised. Because primary hyperparathyroidism is less common in tropical countries doctors may be less familiar with the early manifestations of the disease. The number of patients thus undiagnosed and untreated is unknown.

Adenoma↗
PubMed1992

Characterization of a Drosophila melanogaster gene similar to the mammalian genes encoding the tyrosine/tryptophan hydroxylase activator and protein kinase C inhibitor proteins.

A cloned 1.3-kb cDNA that hybridizes to genomic clone 549, containing genes predominantly expressed in the head of Drosophila melanogaster, was characterized. DNA sequencing showed that the cDNA-encoded protein is similar to a family of mammalian proteins, called 14-3-3, which activate tyrosine hydroxylase (TyrOHase) and tryptophan hydroxylase (TrpOHase), the two key enzymes regulating biosynthesis of biogenic monoamine neurotransmitters, such as dopamine and serotonin, in the brain. The putative D. melanogaster 14-3-3 protein (D14-3-3) shares 72.4, 74.3 and 78.3% amino acid (aa) sequence identity and 83.5, 87.7 and 85.9% aa sequence similarity with the beta, gamma and eta forms of bovine 14-3-3 protein, respectively. A lower (71%), but significant level of aa sequence identity was also found between D14-3-3 and sheep brain protein kinase C inhibitor protein (KCIP). The D14-3-3 gene expresses 1.0-, 1.9- and 2.9-kb mRNAs which show differential expression patterns. While the 2.9-kb mRNA is expressed only in the head, the other two mRNAs are found both in the head and body. Compared to the 1.9- and 2.9-kb mRNAs, the 1.0-kb mRNA is more abundant in the ovary and is probably maternally inherited. The 1.9-kb mRNA is the most predominant species in the embryos and its level peaks between 6-15 h of embryogenesis. The D14-3-3 gene is predominantly expressed in the ventral nerve cord of the embryo, and in the neural tissues of the head.(ABSTRACT TRUNCATED AT 250 WORDS)

14-3-3 Proteins↗
PubMed1992

The Drosophila G protein gamma subunit gene (D-G gamma 1) produces three developmentally regulated transcripts and is predominantly expressed in the central nervous system.

A genomic clone, 536, located at the 44CD region of polytene chromosomes of Drosophila melanogaster, has been characterized for its neurobiological importance. We found that this clone contains a gene which produces 2.6-, 1.3- and 1.1-kilobase (kb) RNAs. While the 2.6-kb RNA is expressed only in the head, the 1.3-kb RNA is present exclusively in the body. The 1.1-kb RNA, however, is found in both the head and body, but in much higher concentration in the head. DNA sequence analysis of a 2.6-kb RNA-specific cDNA showed that this gene encodes a 70-amino acid polypeptide which is the putative Drosophila homologue to the gamma subunit of the bovine G-protein. The Drosophila protein, named D-G gamma 1, shares 46, 43, and 28% identity, and 59, 52, and 60% similarity, with the gamma 2, gamma 3, and gamma t proteins of bovine G proteins, respectively. Sequencing of the 1.1-kb RNA-specific cDNA clone revealed that the 1.1-kb RNA is produced from the 2.6-kb transcription unit by usage of an alternative polyadenylation site, and has a coding region identical to that of the 2.6-kb RNA. Genomic Southern blot hybridization indicated that the Drosophila genome has only one D-G gamma 1 gene. Throughout development the 1.1-kb RNA is found to be the most prevalent species; its level peaks between 9 and 12 h of embryogenesis. As is the case for the other G protein genes of Drosophila, the D-G gamma 1 gene is predominantly expressed in the central nervous system of the fly.

Amino Acid Sequence↗
PubMed1992

A BamHI repeat element is predominantly associated with the degenerating neo-Y chromosome of Drosophila miranda but absent in the Drosophila melanogaster genome.

In Drosophila miranda, females have two X1 and two evolving X2 chromosomes, and males have one of each of these two X chromosomes and a Y chromosome. In males, the homologue of the X2 chromosome, the neo-Y chromosome, is attached to the Y chromosome and is under the process of degenerative evolution. We have examined a developmentally regulated X2/neo-Y chromosome-linked gene, 549mr, of D. miranda and found that the neo-Y chromosome-linked copy of this gene (549mr-NY) contains an insertional DNA. We discovered that sequences similar to those in the insertional DNA are present in multiple copies in the genome of both sexes of D. miranda but are more abundant in the males. The insertional DNA also identified a 1.1-kilobase BamHI repeat that is present in at least 6-fold excess in the male genome as compared to the female. This BamHI repeat and similar DNA sequences are predominantly concentrated on the evolving neo-Y chromosome, but very few are found on the homologous X2 and other chromosomes. The BamHI repeat also hybridizes with 2.0- and 1.8-kb RNAs and many other RNA species, which together are also approximately 6-fold greater in males. No sequences similar to the BamHI repeat are found in Drosophila melanogaster. Moreover, the BamHI repeat is not homologous to P, copia, or other D. melanogaster transposable elements. This repeat, named the NY element, may be involved in gene disruption and the process of degenerative evolution of the neo-Y chromosome.

Animals↗
PubMed1991

Dosage compensation of a retina-specific gene in Drosophila miranda.

The X1R chromosome of Drosophila miranda and the 3L autosome of Drosophila melanogaster are thought to have originated from the ancestral D chromosomal element and therefore may contain the same set of genes. It is expected that these genes will be dosage compensated in D. miranda because of their X linkage. To test these possibilities and to study evolution of the dosage compensation mechanism, we used the 3L-linked autosomal head-specific gene 507 ml of D. melanogaster to isolate the homologous gene (507mr) from a D. miranda genomic library. In situ hybridization showed that gene 507 is located at the 12A region of the X1R chromosome of D. miranda, indicating that the chromosomal homology deduced by cytogenetic means is correct. Restriction analysis and cross-specific DNA and RNA blot hybridization revealed the presence of extensive restriction pattern polymorphism and lack of sequence similarity in some areas of the 507mr and 507 ml DNA, including the 3' portion of the transcribed region. However, the 5' portion of the transcribed region and the DNA sequences, located approximately 0.8 kb upstream and 3 kb downstream from the 507 ml gene showed a high degree of similarity with the DNA sequences of comparable regions of the 507mr gene. In both species gene 507 codes for a highly abundant 1.8 kb RNA which is expressed in the retina of the compound eye. Although in D. miranda the males have one and the females have two copies of the 507 gene, the steady-state levels of the 507 mRNA in both sexes were found to be similar, indicating that gene 507 is dosage compensated in D. miranda.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol Dehydrogenase↗
PubMed1989

Factors affecting immunization rate in a cohort of elderly veterans: a retrospective pilot study of influenza vaccine compliance.

A survey of aged veterans greater than or equal to 85 years old was undertaken to determine their vaccination behaviour prior to mounting a local education campaign on influenza vaccine. A questionnaire inquiring into circumstances which may have influenced their decision to be immunized against influenza was mailed to all 300 elderly veterans (greater than or equal to 85) obtained from the register at the James A. Haley Veterans' Hospital. Ninety-two persons responded in self addressed stamped envelopes and data were analysed six months following mailing date. The most important reason for not being immunized was lack of information concerning vaccine recommendations and its availability (48%). Fear of 'shots' and side effects was the next most important reason for not taking the vaccine (19%). Amotivation and transportation difficulties played comparatively minimal roles (10%, 13%). These data suggest that health education measures may improve vaccine compliance in the elderly population who suffer from higher death rates and complications from influenza.

Aged↗
PubMed1988

Nucleotide sequence of the Drosophila glucose-6-phosphate dehydrogenase gene and comparison with the homologous human gene.

Glucose-6-phosphate dehydrogenase (G6PD) has a major role in NADPH production and is found in almost all cell types. The structural gene for G6PD is X-linked in Drosophila melanogaster, as it is in most eukaryotic organisms, and due to its ubiquitous expression, it can be considered a typical 'housekeeping' gene. Here we present the complete nucleotide (nt) sequence of G6PD cDNAs as well as the genomic copy of the G6PD gene. The G6PD gene has three introns so that the protein-coding region is divided into four segments. The 5'-end of mature G6PD mRNA is located 289 +/- 1 nt upstream from the start codon. The sequence upstream from the transcription start point is G + T-rich and contains no commonly found transcription regulatory elements, such as a TATA box or GGGCGG sequence. D. melanogaster G6PD is 65% homologous with the human G6PD protein but has no homology with the human sequence for the first 42 amino acid residues. The G6PD gene was shown to be active when transduced to autosomal positions. For each transformant, G6PD activity in both male and female adults was not significantly different, indicating that the transduced gene, unlike the resident G6PD, is not dosage-compensated in males.

Amino Acid Sequence↗
PubMed1988

Immunostimulating agents against influenza virus infection in senescent rats.

This study investigated the nonspecific immunomodulatory effects of Bacillus Calmette-Guerin (BCG), muramyl dipeptide (MDP) and ascorbic acid (vitamin C) on virus infection of the respiratory tract in Fischer-344 rats. Groups of young adult (12-16 months old) and aged (24-30 months old) rats were given BCG or MDP intranasally or vitamin C orally 6 weeks and again 3 days before an intranasal challenge with influenza virus A/Bangkok/H3N2 (10(6) 50% EID). Titers of hemagglutinin in lung homogenates and the presence of leukocytes in the respiratory tracts served as indices of infection. Lung macrophage functions of animals were determined by measuring random migration and phagocytic yeast cell killing in vitro. Clearance of Staphylococcus aureus from the respiratory tracts of the animals was also measured 4 hours after challenge. - Following BCG treatment, significantly fewer animals developed virus infection. MDP and vitamin C treatments also reduced the numbers of infected rats but did not differ significantly from the untreated control groups. BCG and MDP treatments significantly reduced the numbers of lung leukocytes in virus infected animals. Mean virus titers in the lung homogenates were significantly lower in all treatment groups by the third day of infection. Following all treatments, duration of virus infection was significantly shorter in the aged compared to the young adult groups. Lung macrophage functions increased in all treatment groups. The improvement of aged groups over their controls was greater than that of the young adults compared to their controls. BCG had the greatest protective effects in both the young adult and aged animals; MDP and vitamin C, in that order, were less effective.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Immunologic competence of hemodialysis patients following withdrawal of vitamin C supplement.

Twelve stable nondiabetic patients on chronic hemodialysis were studied for their immunobiologic competence while receiving vitamin C supplement and 1-2 months following its withdrawal. These subjects, on prescribed diets, were checked for their food intake at the beginning of the study and at 1-month intervals thereafter. Immunological parameters tested were: (1) plasma vitamin C levels; (2) number of mononuclear cells isolated from blood and their vitamin C contents; (3) lymphocyte blastogenic response to mitogens; (4) leukocyte metabolic functions in presence of endotoxin by nitroblue tetrazolium reduction test, and (5) delayed hypersensitivity to skin-testing antigens, e.g. Candida and mumps antigens and purified protein derivative. Patients on vitamin C had significantly higher plasma ascorbic acid levels compared to normal healthy subjects. These decreased to low normal levels 1 month following withdrawal of the supplement and stayed comparable thereafter, up to 12 months of the study period. Ascorbic acid contents in the isolated mononuclear cells remained unchanged in patients on or off vitamin C. The number of blood mononuclear cells isolated and mitogenic responses to concanavalin A and phytohemagglutinin did not change following withdrawal of vitamin C supplement. All patients had positive delayed hypersensitivity to Candida, 60% to mumps and all were unresponsive to purified protein derivative. Leukocyte metabolic functions by nitroblue tetrazolium reduction test were higher in patients on vitamin C than when off, but this was not statistically significant. Vitamin C supplement is not necessary in hemodialysis patients when they are on an adequate diet.

Aged↗
PubMed1986

Longitudinal follow-up of chronic hemodialysis patients without vitamin supplementation.

Vitamin supplementation for dialysis patients is still controversial. In our study, we followed longitudinally over a period of a year, 15 patients on chronic hemodialysis who were deprived of vitamin supplementation. Microbiological assays were used to determine the levels of five vitamins of the B group (folate, niacin, B12, B6, and thiamine). Vitamin C was measured chemically. During the observation period when vitamins were not supplemented, a marked drop of many of these vitamins in blood levels were encountered. For vitamins B12 and C, the plasma levels remained within the normal range in all the subjects studied. For the other vitamins, the blood levels were found to be low in a few patients. Our data suggest that vitamin supplementation is probably not needed in most stable hemodialysis patients as it is recommended now, and that perhaps, if supplementation is indicated, less should be given than is presently prescribed. Further research is needed in this area.

Adult↗
PubMed1985

Isolation and characterization of the glucose-6-phosphate dehydrogenase gene of Drosophila melanogaster.

To investigate the molecular basis of dosage compensation in Drosophila, a recombinant lambda phage containing the Drosophila melanogaster glucose-6-phosphatase dehydrogenase (G6PD) gene was isolated by differential screening of a Drosophila genomic lambda library with poly(A)+RNA obtained from polyribosomes enriched for or depleted of G6PD mRNA sequences. Of 44 000 plaques screened, a single phage, lambda DmG21, showed hybridization with the enriched poly(A)+RNA but not the depleted one. Confirmation that the Drosophila DNA fragment cloned in lambda DmG21 contains the G6PD gene sequence is based on the following observations. lambda DmG21 DNA shows hybridization only to the 18D region of the salivary gland X-chromosome, which is the known cytological locus for the G6PD gene. In vitro translation of the poly(A)+mRNA selected by hybridization to lambda DmG21 DNA sequences shows a polypeptide product of apparent Mr 55 000, identical to that of the monomeric unit of G6PD. When the putative coding sequence of G6PD is cloned into the expression vector lambda gt11, recombinant plaques are recognized by anti-G6PD immunoglobulin. A transcriptional map of the G6PD gene shows that it is divided into two exons, 0.9 kb (exon I) and 1.8 kb (exon II) long, which are separated by a 2.4-kb intron. The G6PD mRNA is 2.0 kb in length and the steady-state level of the mRNA is similar in both sexes. Measurement of the copy number of the G6PD gene in males and females shows the gene to be present once per X-chromosome in both sexes. No amplification of the gene sequence was observed in males. These results are, therefore, in agreement with the previous suggestion that dosage compensation is the result of enhanced transcription of X-linked genes in males.

Animals↗
PubMed1985

Age interference of lymphokine production by lung derived lymphocytes.

Young adult and aged guinea pigs, 1 and 3 years old respectively, were sensitized intranasally with Bacillus Calmette Guérin (BCG). Lung lavage cells were harvested at 2, 3, 6 and 7 weeks following sensitization and tested for migration inhibitory factor (MIF) production in Mackaness chambers with purified protein derivative (PPD). Oil induced normal pig macrophages were used as indicator cells. Aged guinea pigs, compared to young adult guinea pigs, showed significant delay and reduced levels of MIF production at 2 to 3 weeks. Delayed hypersensitivity skin reaction (DHS) to PPD was also less pronounced at 6 weeks. Senescent immune lung cells were inhibitory to migration of indicator cells in absence of PPD.

Aging↗