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Biomedical subjects

R Verma

Publications and source records attributed to R Verma.

At least 73 records · Page 4Linked to original sources
PubMed1994

Use of cutoff pigtail catheters with intraluminal guidewires in interventional procedures in congenital heart disease.

Advances in interventional cardiac catheterization have necessitated technique modifications to ensure patient safety while allowing data acquisition. The use of cutoff pigtail catheters over guidewires for pressure recordings and angiography exemplifies such a modification. The primary purpose of this study was to ascertain contrast volume and flow rates achievable using such a system. A total of 140 used catheters of various sizes, with intraluminal guidewires (0.035 inch in 6, 7, and 8F; 0.025 inch in 5F) were subjected to contrast injections at increasing rates and volumes until rupture occurred. The 7F catheters allowed volume delivery at 15-40 ml at 15 ml/sec, 8F catheters 40 ml at 30 ml/sec, and 5 and 6F catheters 10 ml at 10 ml/sec. All ruptured within 3 cm of the hub, at < or = 900 PSI. A review of 737 clinical procedures revealed adequate pressure recordings and angiographic details in all, uncomplicated save for one intracardiac wire dislodgement.

Cardiac Catheterization↗
PubMed1994

Idiopathic hypertrophic cranial pachymeningitis: a case report.

Hypertrophic pachymeningitis is a rare fibrosing inflammatory process involving dura mater and tentorium. In this report we are presenting contrast enhanced MRI findings of an unusual case of pachymeningitis which presented with a periorbital mass due to dural sinuses occlusion and retrograde filling of periorbital veins through superior sagittal sinus.

Adult↗
PubMed1993

The pre- and postnatal development of Na+/K(+)-ATPase in gastrointestinal organs of the rat: effect of betamethasone treatment.

Developmental changes in Na+/K(+)-ATPase enzyme activity have been documented postnatally in a number of organs, but little is known about prenatal levels or the factors affecting them. This study determined the normal developmental patterns of Na+/K(+)-ATPase activity in the pancreas, liver, small intestine, kidneys, and colon of pre- and postnatal rats. In addition the effect of betamethasone administration on enzyme activity was determined both antenatally and postnatally. The individual organs showed a variable pattern of maturational change in enzyme activity. In the pancreas, changes in Na+/K(+)-ATPase activity appeared to reflect the changing ratio of ductular to acinar cells. The pattern of enzyme activity in the small intestine was similar to that of the kidney and was inversely related to that of the colon. Enzyme induction by administration of betamethasone was also variable and bore no relationship to the DNA/protein ratio. In the preterm rat, betamethasone increased the Na+/K(+)-ATPase activity only in the colon. Use of steroids to increase enzyme activity in the colon at an early stage of development may have therapeutic implications for treating abnormalities of potassium and sodium homeostasis in the preterm infant.

Animals↗
PubMed1993

Recent improvement in outcome using transcatheter embolization techniques for neonatal aneurysmal malformations of the vein of Galen.

Vein of Galen malformations may present as congestive heart failure in the neonate and are usually fatal if untreated. Early studies using transcatheter embolization techniques, in a series of 22 patients, had a 50% mortality rate and a 37% incidence of severe mental retardation in survivors. Modifications of embolization techniques and neonatal care have improved the outlook in a more recent series of 11 patients. The diagnosis was established within 3 days of life in 91% of the cases. No mortality occurred, and 6 of the patients were functionally normal at up to 30 months' follow-up. Although two patients had severe neurologic deficits and/or a seizure disorder, only one case was possibly temporally associated with the embolization procedure. Some developmental delay was noted in one other patient. These improvements result, in part, from modifications of the treatment protocol, including earlier diagnosis, avoidance of digoxin, improvement in the application of newer microcatheters and acrylic polymers (n-butylcyanoacrylate), avoidance of overly aggressive neurosurgical procedures, and the use of stable central vascular access for total parenteral nutrition accompanying other general improvements in neonatal care.

Catheterization↗
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↗