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Biomedical subjects

A Agrawal

Publications and source records attributed to A Agrawal.

At least 163 records · Page 9Linked to original sources
PubMed1988

Depressant effect of acetate in isolated cardiac tissue.

Because acetate may have cardiodepressant properties in vitro, but previous studies have not separated out effects of acetate from possible effects of osmolality, sodium concentration, or calcium complexing, the effects of isosmotic acetate substitution (at a constant calcium concentration) on contractility were studied in isolated rat atrial tissue and in an isolated perfused non-working whole heart preparation. In spontaneously contracting right atrial tissue acetate induced dose dependent inhibition of isometric tension in the clinically important dose range of 4 to 16 mmol.litre-1. Bath acetate concentrations of 4, 16, or 64 mmol.litre-1 reduced peak tension (mean(SEM] to 78(2.7)%, 56(2.5)%, or 61(4.6)% respectively of control values. Because the calcium concentrations of the acetate baths were set equal to that of the control bath, calcium complexing by acetate could not have accounted for acetate's cardiodepressant effect. The inhibitory action was demonstrable with both isosmotic and hyperosmotic acetate solutions. Acetate had no effect on the spontaneous rate of atrial contraction. Inhibition of contractility (+dP/dt) by acetate in the whole heart preparation was also demonstrable at bath acetate concentrations of 8 and 16 mmol.litre-1. The results suggest that acetate has a myocardial depressant effect in vitro at concentrations achievable in the plasma during haemodialysis. The myocardial depressant action is not dependent on calcium complexing or on changes in bath osmolality or sodium concentration.

Acetates↗
PubMed1987

Sensitivity of protein and RNA synthesis to emetine in axenic Entamoeba histolytica.

The action of emetine on the incorporation of (14C)1-DL-valine and (14C)-8-adenine in TCA insoluble fraction of axenic Entamoeba histolytica was investigated. These compounds were almost exclusively incorporated in the 'protein' and 'RNA' fractions, respectively. Incorporation of the purine showed a significantly higher sensitivity to emetine. While the percentage inhibition of valine incorporation by emetine decreased with increasing pH, the susceptibility of adenine incorporation was greater in the alkaline range.

Adenine↗
PubMed1981

Production of beta-galactosidase from Kluyveromyces fragilis grown on whey.

Optimum conditions for beta-galactosidase production by K. fragilis were studied. Enzyme production has a maximum after 8-12 h of incubation. Composition of whey (from different sources) did not affect enzyme production. Different heart treatments also had no effect. Whey reconstituted to 8-12% total solids and adjusted to pH 4.0 afforded maximum enzyme production. Whereas inorganic nitrogen sources (specially ammonium salts) only slightly stimulated enzyme production, organic nitrogen sources (specially partially digested proteins) provided a nearly four-fold increase in enzyme production. Yeast extract and beef extract and industrial by-products like corn-steep liquor significantly stimulated enzyme production. Manganese and magnesium salts had a very little stimulation effect.

Animals↗
PubMed1981

Effect of procarbazine on benzodiazepine receptor in mouse brain.

Procarbazine, a non-benzodiazepine tranquilizer and anti-convulsant, significantly decreased the binding of [3H]diazepam to mouse cerebellar membranes. The drug treatment reduced both the affinity and density of the receptor. The effect, however, was more pronounced on the number of binding sites suggesting occupation of the receptor by procarbazine. The results suggest that benzodiazepine receptors may also be involved in the pharmacological action of non-benzodiazepine drugs.

Animals↗
PubMed1977

Bacteremia after upper gastrointestinal endoscopy.

During 24 months, 200 upper gastrointestinal endoscopies were performed on 193 patients. Blood cultures were obtained before and five and 30 minutes after the procedure using thiol (50 ml) and trypticase soy broth (100 ml) media. The mean endoscopic time was 34 minutes. Sixteen patients developed bacteremia (8%). Twelve groups of microorganisms were detected in positive blood cultures: Streptococcus (5 species), Lactobacillus sp, Veillonella alcalescens, Staphylococcus aureus, Staph epidermidis, Propioni-bacterium acnes, Corynebacterium acnes, and Bacillus subtilis. Seven patients had positive blood cultures at five and 30 minutes, eight at five minutes, and one at 30 minutes only. There was no clear correlation of bacteremia with the age or previous history of the patient, biopsy, active bleeding, endoscopic time, or findings. A follow-up study of all patients for six months to two years indicated no complications related to endoscopy and/or bacteremia.

Adult↗
PubMedDate not supplied

Two cases of cutaneous phaeohyphomycosis caused by Curvularia pallescens.

Two cases of cutaneous phaeohyphomycosis caused by Curvularia pallescens are described. Lesions were found on the feet, thigh and thumb and were irregularly marginated, pruritic black and occasionally purulent. Histopathology revealed heavy infection of the stratum corneum and other cutaneous layers as well as host tissue response. The fungus appeared as dark, aggregated to simple branched hyphae. Oxiconazole was most effective 'in vitro' against the pathogen. This is the first report of C. pallescens as an opportunistic pathogen of human skin.

Adult↗
PubMedDate not supplied

Secretion of acid phosphatase by axenic Entamoeba histolytica NIH-200 and properties of the extracellular enzyme.

Entamoeba histolytica (NIH-200) secreted large amounts of acid phosphatase in its external environment when grown axenically in modified TPS-II medium. Fractionation by DEAE-cellulose chromatography of the precipitate obtained from the cell-free medium at 60% ammonium sulfate saturation yielded 3 distinct peaks of enzyme activity. The enzyme in all the peaks showed resistance to tartrate but was inhibited by fluoride, cupric chloride, ethylene diamine-tetra acetic acid, ammonium molybdate and cysteine; however, enzyme associated with different peaks differed in its polyacrylamide gel electrophoretic profiles and behavior towards concanavalin A.

Acid Phosphatase↗
PubMedDate not supplied

GEM: a proposal for a more comprehensive guideline document model using XML.

OBJECTIVE: To develop a guideline document model that includes a sufficiently broad set of concepts to be useful throughout the guideline life cycle. DESIGN: Current guideline document models are limited in that they reflect the specific orientation of the stakeholder who created them; thus, developers and disseminators often provide few constructs for conceptualizing recommendations, while implementers de-emphasize concepts related to establishing guideline validity. The authors developed the Guideline Elements Model (GEM) using XML to better represent the heterogeneous knowledge contained in practice guidelines. Core constructs were derived from the Institute of Medicine's Guideline Appraisal Instrument, the National Guideline Clearinghouse, and the augmented decision table guideline representation. These were supplemented by additional concepts from a literature review. RESULTS: The GEM hierarchy includes more than 100 elements. Major concepts relate to a guideline's identity, developer, purpose, intended audience, method of development, target population, knowledge components, testing, and review plan. Knowledge components in guideline documents include recommendations (which in turn comprise conditionals and imperatives), definitions, and algorithms. CONCLUSION: GEM is more comprehensive than existing models and is expressively adequate to represent the heterogeneous information contained in guidelines. Use of XML contributes to a flexible, comprehensible, shareable, and reusable knowledge representation that is both readable by human beings and processible by computers.

Algorithms↗
PubMedDate not supplied

Transcatheter closure of a large coronary artery fistula with Amplatzer duct occluder: a new approach.

We report a new retrograde approach for the successful closure of a large right coronary artery fistula in a 27-year-old man using the Amplatzer duct occluder. The device was deployed through a coronary angioplasty-guiding catheter that had been advanced through the aorta and the dilated right coronary artery into the fistula. This method simplified the procedure by eliminating the need for making a femoral artery-to-femoral vein wire loop.

Adult↗