PubMed Health⌕ Search

Biomedical subjects

R Upadhyay

Publications and source records attributed to R Upadhyay.

At least 19 recordsLinked to original sources
PubMed1999

Trans-acting factors that interact with the proximal promoter sequences of ovalbumin gene are tissue-specific and age-related.

Aging or deterioration of functions of various organs occurs after adulthood due to alterations in the expression of genes that maintain adulthood functions. Molecular changes that occur in regulation of genes in higher organisms after adulthood can be understood by using genes whose timing and rate of expression run parallel with specific functions during the life span. One such function is egg formation in birds which is dependent on the expression of egg protein genes, ovalbumin, lysozyme, vitellogenin, etc. Trans-acting factors are known to play a pivotal role in the regulation of transcription of genes. We show here a decrease in the level/binding of nuclear trans-acting factors with specific cis-acting elements of the promoter of the ovalbumin gene of oviduct of old Japanese quail. This parallels the decrease in the expression of the ovalbumin gene in the oviduct after adulthood. These factors are tissue-specific and bind in a cooperative and sequential manner to the ovalbumin gene promoter.

Age Factors↗
PubMed1998

Activation of vitellogenin II gene expression by steroid hormones in the old Japanese quail.

Alterations in the basal transcription rates of eukaryotic genes are believed to involve the binding of trans-acting factor(s) with specific DNA sequences in the promoter. We show here two interrelated events for the VTGII gene of the old, non-egg laying Japanese quail: alterations in the structure of the chromatin encompassing the gene, and binding of trans-acting factors to the promoter of the gene. Estradiol/progesterone alone or together cause alterations in the conformation of the chromatin of the promoter region of the gene. This may allow free access of nuclear protein(s) to the cis-acting elements, ERE, PRE and NF1, in the promoter of the gene and cause activation of transcription.

Aging↗
PubMed1997

Molecular biology of ageing.

The process of deterioration or ageing of functions that occurs in all organisms after the attainment of reproductive ability is the sum total of the decline in activity of various organs. The functions of different organs begin to deteriorate at different times of the life span and at different rates. It is believed that different genes are involved in the ageing of different organs. Studies on isoenzyme patterns of enzymes show that the genes responsible for coding of different subunits of the enzymes are sequentially expressed during the life span. Also, the decrease in the levels of enzymes seen after adulthood is reversible and can be raised to adult level by inducing their genes by steroid hormones. Another factor that contributes to the decrease in the levels of enzymes is increasing compaction of the chromatin that houses the genes as seen from digestion of chromatin by DNase I and MNase. This decreases the rate of transcription of genes. The expression of many genes declines after adulthood which is due to the decrease in trans-acting nuclear proteins that bind to specific cis-acting sequences in the promoter regions of genes. These proteins are inducible by steroid hormones. Hence the deterioration of functions that occurs after adulthood can be delayed, and the adulthood period can by prolonged by manipulation of the expression of genes.

Adult↗
PubMed1996

Age-related changes in the ovalbumin gene of the Japanese quail.

Northern hybridization studies showed that the level of ovalbumin mRNA decreases in the oviduct of the Japanese quail after adulthood. In order to find out if this is due to changes in the conformation of the chromatin containing the promoter region of the gene, nuclei of the oviduct of young, adult and old birds were digested by DNaseI and micrococcal nuclease (MNase). Southern hybridization with the labelled promoter showed that this region is less sensitive to the two enzymes in the old birds. Both the endonucleases recognized the same hypersensitive sites. The results indicate that the chromatin containing the promoter is present in an open conformation in adult birds. Gel mobility shift assay using a 20-mer dsDNA containing the CAAT-box and nuclear extract of oviduct shows the presence of trans-acting factors that bind to this region. The levels of these factors are lower in old birds. This may be the reason for the lower expression of the gene in old birds.

Aging↗
PubMed1991

Protection from gastrointestinal side-effects by azapropazone by its incorporation into a glucose-sodium acid citrate formulation.

Addition of glucose and sodium citrate to azapropazone, in proportions of 1:1:1 by weight reduced gastric mucosal damage in rats and there was a trend towards reduction in radiolabelled faecal red cell loss in human volunteers compared with that with azapropazone alone. The glucose and citrate did not affect the pharmacokinetics of azapropazone, or its therapeutic efficacy. While no difference was observed in endoscopic injury and in symptomatic gastrointestinal complaints in a multicentre comparison in rheumatic patients, a striking reduction in symptoms was observed in those patients with a history of severe gastrointestinal intolerance to non-steroidal anti-inflammatory drugs.

Adolescent↗
PubMed1990

Iron deficiency anaemia in patients with rheumatic disease receiving non-steroidal anti-inflammatory drugs: the role of upper gastrointestinal lesions.

Upper gastrointestinal lesions associated with non-steroidal anti-inflammatory drug (NSAID) treatment are commonly implicated as the cause for iron deficiency anaemia in patients with rheumatic diseases. Such patients, however, may also have other causes for iron deficiency, including blood loss from the intestine. One hundred and four patients (mean age 58 years; male 21, female 83; smokers 14) with rheumatic disease (rheumatoid 91, others 13) and absent bone marrow iron stores (mean haemoglobin 83 g/l) were examined. At endoscopy 47 of 104 (45%) had upper gastrointestinal lesions (oesophageal ulcer 4, gastric ulcer 25, gastric erosion 13, duodenal ulcer 4, gastric ulcer and duodenal ulcer 1). Endoscopic healing was assessed in 23 patients with upper gastrointestinal lesions. Eighteen of 23 (78%) lesions healed with treatment. An improvement of anaemia occurred in 10 of 18 (56%) patients with healed lesions. Twenty three of 104 (22%) patients had dyspeptic symptoms. Ten of 23 (43%) patients with dyspepsia had an upper gastrointestinal lesion as compared with 30 of 81 (37%) patients without dyspepsia. A faecal occult blood test result was available in 53 patients. Of these, 13 were positive while 40 were negative. An upper gastrointestinal lesion was present in seven of 13 (54%) patients positive for the faecal occult blood test as compared with 14 of 40 (35%) negative for the test. Thus upper gastrointestinal lesions have previously been overestimated as the cause of iron deficiency anaemia in patients receiving NSAIDs. A positive faecal occult blood test or the presence of dyspepsia is not associated with upper gastrointestinal lesions in such patients.

Adult↗
PubMed1990

Helicobacter pylori: bridging the credibility gap.

In summary, therefore, there are interesting associations between H pylori, duodenal ulcer, and non-ulcer dyspepsia. In type B gastritis there may be enough evidence to suggest a causal role. The relation between gastritis and upper gastrointestinal symptomatology, however, remains contentious. The relation between H pylori and acid secretion may be more intimate than was previously thought. 'Pylorites' must temper their enthusiasm and provide hard data; 'Schwartzians' must broaden their horizons.

Campylobacter Infections↗
PubMed1990

Gastric antral vascular ectasia (watermelon stomach)--therapeutic options.

We have encountered five cases of chronic iron deficiency anaemia due to bleeding from gastric antral vascular ectasia (watermelon stomach). Two cases were associated with a lymphoma and in three cases there was evidence of portal hypertension. Two patients were treated conservatively by blood transfusions. The other patients required either surgery or tranexamic acid or endoscopic laser therapy to control the chronic haemorrhage.

Aged↗
PubMed1990

Gastric mucosal prostaglandin synthesis in the presence of Campylobacter pylori in patients with gastric ulcers and non-ulcer dyspepsia.

It is unclear how Campylobacter pylori (CP) interacts with gastric mucosal prostaglandins (PG). In a double-blind study we measured gastric PG synthesis in 22 patients with benign gastric antral ulcers (GU) and 26 with non-ulcer dyspepsis (NUD). CP status was determined by histology and bacteriology: 26 (16 GU plus 10 NUD) were CP positive, and 22 (6 GU plus 16 NUD) were CP negative. Patients with severe gastritis regardless of CP status) had significantly higher PGE2 and PGI2 values than those with mild gastritis. Severe gastritis was found in 36% of CP-negative subjects and 77% of the CP-positive patients (chi 2 = 8.64, p less than 0.01), but no significant differences in PG values were found between CP-positive or -negative patients.

Adult↗
PubMed1989

Campylobacter pylori and gastroduodenal disease. Is there a relationship?

Much has been discovered about Campylobacter pylori in the past 6 years. Yet, many questions remain: Is the organism commensal or is it a pathogen? What is its environmental source? How is it transmitted? What is its role in gastroduodenal disease? The authors of this article discuss these and other issues relating to this common organism.

Breath Tests↗
PubMed1988

Campylobacter pylori associated gastritis in patients with rheumatoid arthritis taking nonsteroidal anti-inflammatory drugs.

Fifty-two patients with rheumatoid arthritis taking nonsteroidal anti-inflammatory drugs were studied in order to assess the carriage rate of Campylobacter pylori (C. pylori) with reference to dyspeptic symptoms, endoscopic appearance and antral histology. All patients were interviewed using a standard gastrointestinal symptom scoring questionnaire and underwent endoscopy at which two antral biopsies were obtained. Sections were examined for the presence and severity of gastritis and of C. pylori. Forty-four of 52 patients (85%) had histological evidence of gastritis. Twenty-six of 44 (59%) patients with gastritis were positive for C. pylori. Twenty-six of 28 patients with 'active' (polymorph infiltration) chronic gastritis were positive for C. pylori (p less than 0.002). Sixteen of 26 bacteria-positive patients had gastrointestinal symptoms compared with eight of 26 bacteria-negative patients (p less than 0.05) and this may have therapeutic implications. There was no correlation between the presence of organisms and the appearances at endoscopy.

Adult↗
PubMed1985

Results of simple aspiration of pneumothoraces.

The results of simple aspiration in 30 cases of pneumothorax are presented. The procedure was successful in 33% of cases with known pre-existing lung disease, and in 83% of those without. Aspiration was also more successful in those patients under 50 years of age and if the estimated degree of lung collapse was less than 50%.

Adult↗