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Biomedical subjects

R Ganguly

Publications and source records attributed to R Ganguly.

At least 19 recordsLinked to original sources
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↗
PubMed1979

Influence of virus infection on the leaf protein yield.

Influence of cowpea mosaic virus (CPMV) and common bean mosaic virus (CBMV) infection on the yield of extractable leaf protein of cowpea cvs. Pusa Phaguni, Pusa Barsati, and Yard Long was studied. An increase as well as decrease in the yield of leaf protein concentrate (LPC), due to virus infection, has been observed. CPMV infection increased LPC yield in all the cowpea cvs., but CBMV decreased it in cys. Pusa Phaguni and Yard Long. Variation in percentage of extractable nitrogen and protein in LPC was also notices. However, total N and protein in leaf and LPC were increased due to virus infection, but total sugar and starch decreased.

Carbohydrates↗
PubMed1979

Glucocorticoid modulation of casein gene transcription in mouse mammary gland.

The influence of cortisol and prolactin on casein gene expression in the mammary gland of lactating BALB/c mice was measured by using a specific cDNA probe to 15S casein mRNA (cDNAcsn). Casein mRNA (mRNAcsn) level in the mammary gland was decreased by 85% 5 days after adrenal ablation, but then was increased 4.4-fold 12 hr after a single injection of hydrocortisone-21-acetate. An 80% decrease in serum prolactin level, induced by the prolactin inhibitor 2-bromo-alpha-ergocryptin (CB-154), did not alter the level of mRNAcsn in the gland. Specific transcription of the casein gene in nuclei isolated from lactating mammary glands was measured by cDNAcsn hybridization to the in vitro synthesized Hg-CTP-containing RNA (Hg-RNA), which was purified by SH-agarose chromatography. The level of the mRNAcsn in Hg-RNA synthesized in the isolated nuclei was 0.09% and this was decreased 85% by alpha-amanitin, indicating that the mRNAcsn sequences in the Hg-RNA were the products of RNA polymerase II-directed DNA-dependent RNA synthesis. Transcription of the mRNAcsn in isolated nuclei was decreased by 70% 5 days after adrenalectomy and a single injection of the glucocorticoid then increased the transcription level 2-fold at 6 hr. Essentially no alteration of the level of transcription was detectable in mammary nuclei isolated from lactating mice with 80% decreased serum prolactin level, induced by CB-154 treatment. The results thus demonstrate a glucocorticoid involvement on the modulation of casein gene expression at the transcriptional level of control.

Adrenalectomy↗
PubMed1979

Lack of effect of an interferon inducer, N,N-dihexadecyl-m-xylylenediamine, on rhinovirus challenge in humans.

CP-28,888-27 and placebo nasal sprays were compared in 62 normal volunteers challenged with rhinovirus type 13 or 21 in two randomized, double-blind studies. Half of the subjects received CP-28,888-27 and half received nasal placebo administered at 24, 20, and 16 h before challenge and 4 and 8 h after challenge. In each study, the number of subjects shedding virus in nasal washes, the number developing fourfold or greater serum antibody responses, and the number developing afebrile or febrile upper respiratory tract illness were not significantly different comparing subjects given CP-28,888-27 and those given placebo. Interferon was detected in nasal washes from 5 of 15 volunteers tested in the CP-28,888-27 group compared to 2 of 15 volunteers from the placebo group.

Adult↗
PubMed1979

Guinea pig lung lavage cells after intranasal BCG sensitization.

Recent studies have suggested that intranasal administration of antigen can induce local cell-mediated immunity in lung lavage cells. The present study was designed to examine the changes in composition of lung lavage cells and their capacity to produce the lymphokine migration inhibitory factor after intranasal immunization with BCG in guinea pigs. Results indicate that guinea pigs responded to respiratory tract BCG infection with an increase in immunocompetent cells in the bronchoalveolar tract and with production of migration inhibitory factor. After local pulmonary BCG administration, the total number of cells increased as compared with that of the uninfected animals, the increase being statistically significant within 2 weeks. This marked increase in the total cell population is due to a more than doubling of the number of macrophages in the lavage fluid. Animals also developed at this time positive delayed hypersensitivity to intradermally administered purified protein derivative. A significant increase in the total lymphoid cells and macrophage population was observed again at 6 weeks after sensitization, suggesting that the response is biphasic in nature. At 6 weeks, however, there was also a significant rise in total lymphocytes and T cell population in addition to macrophage numbers. This increase in T cells correlated with an increase in production of migration inhibitory factor in the presence of purified protein derivative. These data suggest that the immune response of the respiratory tract after BCG challenge involves increased recruitment of immunocompetent cells locally at the site of infection and that these cells are capable of producing effector molecules in terms of the elaboration of migration inhibitory factor.

Animals↗
PubMed1978

Studies on oral adjuvants against murine salmonellosis.

1) Attempts were made to develop oral adjuvants against murine salmonellosis. 2) Streptomycin, levamisole and PHA show potential immunoenhancing properties against salmonella infection. 3) The mode of action of these agents remain to be elucidated. Observed results of PHA enhancement may be related to its blastogenic effects in the splenic T-cells. 4) Decrease in certain bacterial flora resulting in less antigenic competition may be the mode of action of streptomycin as adjuvant when added to oral salmonella vaccine.

Adjuvants, Immunologic↗
PubMed1978

Effect of CP-20,961, an interferon inducer, on upper respiratory tract infections due to rhinovirus type 21 in volunteers.

Topically administered CP-20,961 is known to stimulate nasal interferon. Studies in volunteers given the drug prior to challenge with rhinovirus have yielded both fairly good results and only fair or poor results. This study was undertaken in an attempt to settle the differences between the results of these trials and to evaluate the possible effectiveness of CP-20, 961 when given after virus challenge. Sixty volunteers were randomly divided into four groups. One group received placebo, the second received the drug on the day before and the day of challenge, the third was given the drug for two days beginning 24 hr after challenge, and the fourth received the drug for two days beginning 48 hr after challenge. The average number and severity of symptoms in the group that received CP-20,961 prior to challenge were about half of those in the control group. There was no decrease, however, in the number and severity of symptoms in the groups that received the drug after challenge.

Adolescent↗
PubMed1978

RNA synthesis in isolated nuclei of lactating mammary cells in presence of unmodified and mercury-labeled CTP.

Isolated nuclei of lactating mouse mammary gland were capable of supporting DNA-dependent RNA synthesis in vitro in presence of unmodified and mercurated CTP (Hg-CTP) at high ionic condition at 25 degrees C. In presence of unmodified CTP, [3H]UMP incorporation into RNA increased linearly upto 180 min. The kinetic pattern of the reaction and the rate of RNA synthesis were essentially similar when CTP was replaced by Hg-CTP. Both in unmodified and Hg-CTP containing reactions, 70-80% of RNA synthesis was inhibited by alpha-amanitin. Presence of poly(A) in a small portion of the in vitro synthesized messenger-like RNA was detectable by oligo(dT) cellulose chromatography. Both poly(A)+ and poly(A)- RNAs sedimented with a clear peak around 15S region in a formamide-sucrose denaturing gradient. The Hg-RNA after separation from endogenous nuclear RNA by SH-agarose affinity column chromatography also sedimented around 15S region in a formamide-sucrose gradient. The Hg-RNA synthesized in the isolated mammary cell nuclei in vitro should now permit monitoring hormonal regulation of specific gene (casein) transcription in the mammary cells by molecular hybridization of the Hg-RNA with cDNA to casein mRNA.

Amanitins↗
PubMed1977

Therapeutic efficacy of inosiplex (Isoprinosine) in rhinovirus infection.

Inosiplex (Isoprinosine), the paracetamidobenzoic acid salt of inosine dimethylaminoisopropanol, has shown antiviral activity in cell culture and in animals. Controlled challenge studies using the drug in a prophylactic fashion, however, have been disappointing. In vitro studies, as well as uncontrolled clinical trials, have suggested that the drug might be more effective when used therapeutically. We therefore undertook to test inosiplex in a controlled, double-blind, therapeutic study of volunteers challenged with rhinovirus. Thirty-nine volunteers were randomly divided into groups receiving either inosiplex or placebo tablets. Drug or placebo was started either at the time of, or 48 hours after challenge with rhinovirus Type 21. Illness was assessed in terms of the classical common cold symptoms, and infection was also determined by viral isolation from daily nasal wash specimens and by serum antibody rises. Five of 19 volunteers in the inosiplex group became ill, whereas 14 of 20 in the placebo group were sick (p less than 0.01). There was no difference between the control and inosiplex groups in the number of volunteers from whom rhinovirus was isolated. There was, however, a reduction in the duration of virus shedding in the inosiplex group. Seroconversion was also slightly less common in the inosiplex group. Immunologic studies suggest that inosiplex stimulates the lymphocyte mitogenic response. The results suggest that inosiplex exerts significant therapeutic benefits in rhinovirus infection.

Adult↗
PubMed1977

Nonspecific protection of mice against influenza virus infection by local or systemic immunization with Bacille Calmette-Guérin.

Bacille Calmette-Guérin (BCG) has been used effectively to protect nonspecifically against bacterial infections and neoplasms, probably by enhancement of cell-mediated immunity. It has been suggested that cell-mediated immunity plays a role in the host defense against certain viral infections. In recent in vitro studies, macrophages from animals sensitized by BCG were more effective in lowering the titer of influenza virus than were macrophages from control animals. The purpose of this study was to investigate the in vivo effectiveness of nonspecific immune stimulation with BCG on influenza virus infection in mice. Immunization with BCG resulted in significant protection of mice. Also, the local (nasal) route of immunization was more effective than the systemic (intraperitoneal) route against the intranasal inoculum of virus, a finding which suggests that important role of local immunity, i.e., either earlier stimulation of secretory antibody or nonspecific cell-mediated immunity. The time course of the resistance ot infection suggests that interferon was not the protective mechanism.

Administration, Intranasal↗