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Biomedical subjects

R Verma

Publications and source records attributed to R Verma.

At least 19 recordsLinked to original sources
PubMed1992

Regulation of the yeast DNA replication genes through the Mlu I cell cycle box is dependent on SWI6.

In Saccharomyces cerevisiae, at least 17 DNA replication genes are coordinately expressed at the G1/S boundary during the cell cycle. All of these genes have the DNA sequence element ACGCGT in their 5' upstream regulatory regions. This sequence has been shown to be essential for periodic expression of the POL1, CDC9, and TMP1 genes. The cyclin (CLN1 and CLN2) and HO genes are another subset of genes that are expressed with the same timing as the DNA replication genes. Their periodic expression requires the participation of two well-characterized transcriptional activators: the SWI4 and SWI6 gene products. In this study, we present evidence that SWI6 contributes to the regulation of DNA replication genes as well. Surprisingly, a preferential requirement for SWI6 over SWI4 is observed in our studies of ACGCGT-dependent reporter gene expression in vivo. This selectivity has not been observed for the other G1/S genes. Correlating with the in vivo results, protein-DNA complexes formed in vitro on multimeric ACGCGT elements are either abolished or reduced in swi6 delta deletion mutants.

Base Sequence↗
PubMed1992

Randomised controlled trial of cardioprotective diet in patients with recent acute myocardial infarction: results of one year follow up.

OBJECTIVE: To test whether a fat reduced diet rich in soluble dietary fibre, antioxidant vitamins, and minerals reduces complications and mortality after acute myocardial infarction. DESIGN: Randomised, single blind, controlled trial. SETTING: Primary and secondary care research centre for patients with myocardial infarction. SUBJECTS: 505 patients with suspected acute myocardial infarction. Those with definite or possible acute myocardial infarction and unstable angina based on World Health Organisation criteria were assigned to diet A (n = 204) or diet B (n = 202) within 24-48 hours of infarction. INTERVENTIONS: Both groups were advised to follow a fat reduced diet. Group A was also advised to eat more fruit, vegetables, nuts, and grain products. MAIN OUTCOME MEASURES: Mortality from cardiac disease and other causes. Serum lipid concentrations and compliance with diet. RESULTS: Blood lipoprotein concentrations and body weight fell significantly in patients in group A compared with those in group B (cholesterol fell by 0.74 mmol/l in group A v 0.32 mmol/l in group B, 95% confidence interval of difference 0.14 to 0.70, and weight by 7.1 v 3.0 kg, 0.52 to 7.68). The incidence of cardiac events was significantly lower in group A than group B (50 v 82 patients, p less than 0.001). Group A also had lower total mortality (21 v 38 died, p less than 0.01) than group B. CONCLUSIONS: Comprehensive dietary changes in conjunction with weight loss immediately after acute myocardial infarction may modulate blood lipoproteins and significantly reduce complications and mortality after one year.

Adult↗
PubMed1992

An Indian experiment with nutritional modulation in acute myocardial infarction.

In a randomized, single-blind intervention trial, 406 patients 24 to 48 hours after acute myocardial infarction (AMI) were assigned to either diet A (204 patients, group A) or B (202 patients, group B) for 6 weeks. At entry to the study, mean age, male sex, risk factors, complications, possible and definite AMI, and drug therapy were comparable between the 2 groups. Dietary adherence to intervention and control diets was checked by questionnaire, and drug therapy by tablet count. Group A received significantly lower calories, a higher percentage of calories from complex carbohydrates, vegetable/fish proteins, polyunsaturated fatty acids, and a higher polyunsaturated/saturated fat ratio diet than did group B (higher total calories and saturated fatty acids). Group A also received less dietary cholesterol, salt and caffeine, and higher soluble dietary fiber, vitamins and minerals than did group B. After 6 weeks, group A had a significant decrease in mean serum total (-20.5 vs -8.6 mg/dl) and low-density lipoprotein (-16.6 vs -6.4 mg/dl) cholesterols, and triglycerides (-15.5 vs -7.6 mg/dl), with no decrease in high-density lipoprotein cholesterol (-1.5 vs -1.3 mg/dl) compared with the initial levels and changes in group B. Group A also had a greater decrease in mean body weight (3.4 vs 1.3 kg) than that of group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Identification and purification of DBF-A, a double-stranded DNA-binding protein from Saccharomyces cerevisiae.

Using oligonucleotide affinity chromatography with DNase I footprinting as an assay we have looked for proteins that interact with sequence elements within the yeast origin of replication, autonomously replicating sequence 1 (ARS1). In this work we describe a protein that binds with high affinity to DNA but displays only moderate sequence specificity. It is eluted at 0.7 M salt from an ARS1 oligonucleotide column. Footprinting analysis on ARS1 at a high protein concentration revealed at least three sites of protection flanking element A and its repeats. Element A itself is rendered hypersensitive to DNase I digestion upon protein binding. This pattern is also observed for the H4 and HMR-E ARSs, suggesting that the protein alters the DNA conformation at element A and its repeats. The affinity-purified fraction is also capable of supercoiling a relaxed, covalently closed plasmid in the presence of topoisomerase. Highly purified preparations of the protein are enriched in an 18-kDa polypeptide which can be renatured from a denaturing gel and shown to bind ARS1 DNA. We have designated this protein DBF-A, DNA-binding factor A.

Adenosine Triphosphate↗
PubMed1992

Age-specific development of malate-aspartate shuttle in the liver and kidney of mice.

The activities of malate-aspartate shuttle enzymes were measured in the liver and kidney of 15-, 30-, and 60-day old mice. The results indicate that the activities (U/mg protein) of both isoenzymes (cytosolic and mitochondrial) of both malate dehydrogenase and aspartate aminotransferase are significantly higher in the liver of 15-day old mice than in the liver of 30- and 60-day old animals. However, the shuttle enzymes showed a peak value in the kidney of 30-day old mice. In vitro reconstitution of malate-aspartate shuttle showed a similar pattern of activity in the tissues studied. These findings suggest that the activity of malate-aspartate shuttle is expressed differentially in these tissues of mice at different postnatal ages.

Aging↗
PubMed1991

Identification and purification of a factor that binds to the Mlu I cell cycle box of yeast DNA replication genes.

In Saccharomyces cerevisiae, the genes encoding at least 10 enzymes involved in DNA replication are periodically expressed in the late G1 and S phases of the cell cycle. All of these genes have one copy or more of the sequence ACGCGT, which conforms to the recognition site for the Mlu I restriction endonuclease. For the CDC21, CDC9, and POL1 genes, the Mlu I site has been shown to be absolutely required for periodic transcription. Using nuclear extracts fractionated by conventional and oligonucleotide affinity chromatography, we have purified a 17-kDa protein that recognizes the Mlu I motif. Synthetic oligonucleotides containing mutated Mlu I sites do not bind the protein. In contrast, synthetic oligonucleotides derived from the CDC2, CDC6, and CDC21 genes, which are expressed with the same timing as POL1, bind purified protein efficiently.

Bacterial Proteins↗
PubMed1991

A district-wide anaesthetic audit.

A district-wide anaesthetic audit has been implemented by the Derby anaesthetic department. Data for every anaesthetic are collected on a specially designed audit form which is read into a computerised database using an optical mark reader. The implementation of the audit, problems encountered and some benefits realised are described.

Anesthesia↗
PubMed1989

Pain on injection and venous sequelae following two formulations of etomidate.

In forty patients (aged 21-76 years) scheduled for elective surgery, anaesthesia was induced with either etomidate in propylene glycol (n = 20) or etomidate in ethanol (n = 20) injected via a 23-G needle over 30 s. The overall incidence of pain on injection was 60%. No statistically significant difference was found between the two groups. The incidence of venous sequelae was 5%, in both groups.

Adult↗
PubMed1988

Modulation of expression of the stress-inducible p118 of Saccharomyces cerevisiae by cAMP. II. A study of p118 expression in mutants of the cAMP cascade.

In the preceding paper, we have identified a protein of Mr = 118,000 which is induced by stress conditions that lead to cessation of DNA synthesis and cell division (Verma, R., Iida, H., and Pardee, A.B. (1988) J. Biol. Chem. 263, 8569-8575). In the current study, we have investigated the possible role this protein may play in cellular proliferation by studying p118 expression in mutants of the cAMP metabolic pathway. The cyr 1-2 mutant gene encodes a thermolabile adenylate cyclase whose activity is only 7% of wild type even at permissive temperatures (23 degrees C). We have found that at 23 degrees C, the G1 period was 5-fold longer in cyr 1-2 than in CYR1+ cells and that p118 was constitutively expressed in these slow cycling mutants. Addition of 8-bromo-cAMP to cyr 1-2 mutants restored growth at both the restrictive and permissive temperatures and resulted in a shut-off in the synthesis of p118. The effect of the analog on p118 expression was rapid, preceding the increase in cell number and percentage-budded cells. In contrast to wild type cells, p118 synthesis was not induced by sulfur starvation in RAS2val19 mutants possessing high levels of adenylate cyclase activity and bcy1 mutants defective in the regulatory subunit of cAMP-dependent protein kinase. A large body of evidence exists supporting a role of cAMP in positive control of cell proliferation. It is therefore possible that conditions which decrease cAMP arrest growth through a chain of events that include p118 induction.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1988

Identification of a novel stress-inducible glycoprotein in Saccharomyces cerevisiae. I. Preliminary characterization.

We have identified a novel stress-inducible protein in Saccharomyces cerevisiae by pulse-labeling with [35S]methionine and two-dimensional gel analysis. The protein was characterized biochemically to gain further insight into mechanisms regulating the stress response. It has a Mr = 118,000 and exists in two forms of pI = 4.2 (p118A) and pI = 4.3 (p118B). p118A and p118B are modified by N-glycosylation. Tunicamycin treatment revealed the presence of precursor proteins of Mr = 105,000, pI = 4.1 (p105A) and pI = 4.25 (p105B). The synthesis of p118A and p118B was almost completely shut off in cycling cells and was increased 11-fold following a mild heat shock. Both forms of p118 decayed in a biphasic manner under induced conditions. A tight correlation was observed in the kinetics of thermotolerance induction and p118A synthesis. Other forms of stress such as sulfur starvation which lead to arrest in the unbudded phase also resulted in enhanced synthesis of both p118A and p118B. However, in cell division cycle mutants blocked at various stages at the restrictive temperature, p118A and p118B had different synthetic patterns. Taken together, these data imply a role for induced p118 in proliferation arrest in the unbudded state.

Electrophoresis, Polyacrylamide Gel↗
PubMed1988

Early intervention with propranolol after acute myocardial infarction: serial left ventricular function determined by M-mode and cross-sectional echocardiography.

Fifty patients (mean age 48.6 +/- 9.4 years) with uncomplicated acute myocardial infarction were randomly assigned to propranolol therapy (n = 25) or placebo (n = 25) in a double-blind manner within 24 hours of their presentation with acute symptoms. M-mode and cross-sectional echocardiography were performed at one week and three months to evaluate the left ventricular function. A comparison of the two groups revealed that the group receiving propranolol had higher left ventricular ejection fraction (69% vs 52%, P less than 0.001), fractional shortening (32% vs 24%, P less than 0.01), lower mitral E-point septal separation (6 mm vs 14 mm, P less than 0.001) and wall motion abnormality score (2.5 vs 6.0, P less than 0.001) than the group receiving placebo therapy. At three months there was further significant improvement in wall motion abnormality score (1.1 vs 2.5, P less than 0.001) in the propranolol-treated group as compared to the placebo group, whereas the other parameters remained unchanged. We conclude that the left ventricular function detected by M-mode and cross-sectional echocardiography showed significant improvement in patients with acute myocardial infarction after early intervention with propranolol. This is possibly due to a reduction in the size of infarction.

Acute Disease↗
PubMed1988

Choledochal cyst.

Explore the source record for details and available documents.

Adolescent↗
PubMed1987

Intrathoracic complications of acute pancreatitis.

Acute pancreatitis has an incidence of approximately 50 cases per million of the United Kingdom population and a mortality of 10-18%. Intrathoracic complications have been implicated as the major factor in 22-29% and a contributing factor in a further 29-39% of all deaths. Sixty per cent of deaths occur in the first week of hospital admission and in these the pleuropulmonary complication rate is 94%. In the survivors there is little residual lung damage and the recovery of the pulmonary function is invariably complete. Knowledge of the pleuropulmonary complications of acute pancreatitis may aid with the identification of high risk groups so that supportive measures (including mechanical ventilation) can be implemented early in the course of the illness. This article reviews the major intrathoracic complications of acute pancreatitis (Fig. 1) under the broad headings of: 1. pleural effusion 2. acute pulmonary dysfunction (a) hypoxaemia without pulmonary infiltrates (b) hypoxaemia with pulmonary infiltrates (including the adult respiratory distress syndrome; ARDS).

Acute Disease↗
PubMed1987

Respiratory sensitivity to carbon dioxide in schizophrenia.

Respiratory sensitivity was evaluated in 10 patients with schizophrenia and 10 normal control subjects utilizing a rebreathing system and measurements of the changes in the mouth occlusion pressure in 100 ms and ventilation in response to the increase in end-tidal PCO2 (PetCO2). Although ventilation response was similar in both groups, we noted that the occlusion pressure response was more variable (coefficient of variability, CV = 17.5%) and the correlation coefficient (r = 0.75 +/- 0.13) lower in the patients with schizophrenia compared to controls (CV = 4.6%; r = 0.90 +/- 0.04). Apnea threshold was also lower in patients with schizophrenia (29.03 +/- 12.73 Torr, mean +/- SD) compared to controls (39.5 +/- 4.5 Torr). Furthermore, schizophrenia patients showed a significant positive and negative correlation between occlusion pressure response and age (r = 0.73; p less than 0.001) and estimated duration of schizophrenia (r = 0.65; p less than 0.05). We conclude that the apnea threshold is lower and the respiratory sensitivity to CO2 is more variable in patients with schizophrenia compared to normal subjects.

Adult↗