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Biomedical subjects

A Large

Publications and source records attributed to A Large.

7 recordsLinked to original sources
PubMed2002

Changing the diagnostic criteria for myocardial infarction in patients with a suspected heart attack affects the measurement of 30 day mortality but not long term survival.

OBJECTIVES: To explore the effects of alternative methods of defining myocardial infarction on the numbers and survival patterns of patients identified as having sustained a confirmed myocardial infarct. DESIGN: An inclusive historical cohort of patients admitted with a suspected heart attack. Patients were recoded from raw clinical data (collected at the index admission) to the epidemiological definitions of myocardial infarction used by the Nottingham heart attack register (NHAR), the World Health Organization (MONICA), and the UK heart attack study. SETTING: Single health district. PATIENTS: The NHAR identified all patients admitted in 1992 with suspected myocardial infarction. OUTCOME MEASURES: Survival at 30 days and four year postdischarge. RESULTS: 2739 patients were identified, of whom 90% survived to discharge. Recoding increased the numbers of patients defined as having confirmed myocardial infarction from 26% under the original NHAR classification to 69%, depending on the classification system used. In confirmed myocardial infarction, subsequent 30 day survival from admission varied from 77-86% depending on the classification system; four year survival after discharge was not affected. The distribution of important prognostic variables differed significantly between groups of patients with confirmed myocardial infarction defined by different systems. Patients with suspected but unconfirmed myocardial infarction under all classification systems had a worse postdischarge mortality. CONCLUSIONS: The classification system used had a substantial effect on the numbers of patients identified as having had a myocardial infarct, and on the 30 day survival. There were significant numbers of patients with more atypical presentations, not labelled as myocardial infarction, who did badly following discharge. More research is needed on these patients.

Age Factors↗
PubMed2001

The inebri-actometer: a device for measuring the locomotor activity of Drosophila exposed to ethanol vapor.

Drosophila melanogaster can be used as a model organism for probing the genetic basis for alcohol sensitivity. In this paper, we describe a new device, the inebri-actometer, which measures the locomotor activity of up to 128 individual flies simultaneously. The device consists of 128 pairs of emitter/detector photodiodes connected in series through a computer interlink. A single fly is placed in each of the 128 chambers and humidified air or air containing variable amounts of ethanol vapor is pumped through the chambers. When a fly blocks the infrared signal transmitted by an emitter photodiode, the computer records one movement for that fly. We present preliminary results showing the effect of ethanol on the activity of wild-type Oregon R Drosophila. Five preliminary runs with 95% ethanol vapor revealed that this concentration induces an approximately 3- to 4-fold increase in locomotor activity which peaks at about 5 min after the addition of ethanol vapor. This is followed by a gradual decrease in activity leading to a nearly total cessation of movement after 30 min. Statistically significant dose-related activity increases were obtained for ethanol concentrations of 8, 19, 50, and 100% of maximum, assessed in two replications at each dose. Unlike the complete suppression of locomotion seen in the last 10 min of the session at maximum ethanol exposure, the initial stimulation effect at the 19% concentration was maintained across the 30-min session.

Alcoholism↗
PubMed2001

D-Aspartate oxidase and D-amino acid oxidase are localised in the peroxisomes of terrestrial gastropods.

D-Aspartate oxidase and D-amino acid oxidase were found in high activity in the tissues of representative species of terrestrial gastropods. Analytical subcellular fractionation demonstrated that both of these oxidases co-localised with the peroxisome markers, acyl-CoA oxidase and catalase, in the digestive gland homogenate. Electron microscopy of peak peroxisome fractions showed particles of uniform size with generally well preserved variably electron-dense matrices bounded by an apparently single limiting membrane. Many of the particles exhibited a core region of enhanced electron density. Catalase cytochemistry of peak fractions confirmed the peroxisome identity of the organelles. Peroxisome-enriched subcellular fractions were used to investigate the properties of gastropod D-aspartate oxidase and D-amino acid oxidase activities. The substrate and inhibitor specificities of the two activities demonstrated that two distinct enzymes were present analogous to, but not identical to, the equivalent mammalian peroxisomal enzymes.

Amino Acid Oxidoreductases↗
PubMed2000

Gastropod mollusc aliphatic alcohol oxidase: subcellular localisation and properties.

The digestive gland and other tissues of several species of terrestrial gastropod mollusc contain an aliphatic alcohol oxidase activity (EC1.1.3.13). The enzyme is FAD dependent, consumes oxygen and generates hydrogen peroxide and the corresponding aldehyde. Saturated primary alcohols are favoured as substrates with octanol preferred with an apparent Km of 3-4 microM. The activity is clearly distinguishable from previously reported molluscan aromatic alcohol oxidase (EC1.1.3.7) on the basis of FAD dependence, sensitivity to heat treatment and high salt concentration and with regard to substrate preferences. The aliphatic alcohol oxidase is membrane associated and most likely localised to the endoplasmic reticulum. Extraction of membranes with 1% Igipal solubilises the enzyme in active form. This enzyme is a further example of an oxidase apparently restricted to molluscs.

Alcohol Oxidoreductases↗
PubMed1990

Lithium clearance in healthy humans: effects of sodium intake and diuretics.

In summary, our experiments clearly demonstrate that lithium reabsorption occurs by frusemide- and bumetanide-sensitive reabsorption, but we have failed to identify the mechanism(s) responsible for the lower CLi and FELi in salt-depletion. It is possible that some, as yet unknown, factor increases the activity of the Na, K, 2Cl cotransporter and, hence, increases lithium reabsorption in the thick ascending limb in salt-depleted subjects. However, it is equally possible that a fraction of proximal tubular reabsorption is inhibited by frusemide and bumetanide. If this is correct, CLi in humans are reasonable markers of proximal tubular function even in conditions of avid salt retention and in salt depletion, when fractional reabsorption of salt and water in the proximal tubules is enhanced.

Amiloride↗