Three-year prospective validation of a pre-endoscopic risk stratification in patients with acute upper-gastrointestinal haemorrhage.

Objective: To assess the accuracy of a risk stratification that is used at initial assessment to identify groups with increased risk of mortality and requirement for urgent treatment intervention.

Design: Prospective assessment of risk stratification in consecutive patients with acute upper-gastrointestinal haemorrhage.

Methods: Over a 3-year period, 1349 consecutive patients with acute upper-gastrointestinal haemorrhage presenting to a single teaching hospital were prospectively risk stratified before endoscopy and followed up for outcome.

Covert attention affects the psychometric function of contrast sensitivity.

We examined the effect of transient covert attention on the psychometric function for contrast sensitivity in an orientation discrimination task when the target was presented alone in the absence of distracters and visual masks. Transient covert attention decreased both the threshold (consistent with a contrast gain mechanism) and, less consistently, the slope of the psychometric function. We assessed performance at 8 equidistant locations (4.

The common retroviral insertion locus Dsi1 maps 30 kilobases upstream of the P1 promoter of the murine Runx3/Cbfa3/Aml2 gene.

The Dsi1 locus was identified as a common integration site for Moloney murine leukemia virus (MLV) in rat thymic lymphomas, but previous efforts to identify a gene affected by these insertions were unsuccessful. We considered the Runx3 gene a potential candidate on the basis of genetic mapping which showed that Dsi1 and Runx3 are closely linked on mouse chromosome 4 and the precedent of the related Runx2 gene, which emerged recently as a Myc-collaborating gene activated by retroviral insertion in thymic lymphomas of CD2-MYC mice. We now report the physical mapping of the Dsi1 locus to a site 30 kb upstream of the distal (P1) promoter of the murine Runx3 gene.

Characterizing visual performance fields: effects of transient covert attention, spatial frequency, eccentricity, task and set size.

We investigated whether transient covert attention would differentially affect 'performance fields' (shape depicted by percent correct performance at particular locations in the visual field) for orientation discrimination, detection and localization tasks, while manipulating a number of visual factors. We found that although attention improved overall performance, it did not affect performance fields. Two patterns were observed regardless of the presence of a local post-mask, the stimulus orientation, or the task.

The deafening silence of AIDS.

For most of those attending the XIII International AIDS Conference in Durban, the Jonathan Mann Memorial Lecture delivered by Justice Edwin Cameron on Monday, 10 July 2000, was one of the highlights of the conference. The presentation is a passionate and compelling appeal to make medical care and treatment accessible and affordable to the more than 30 million people in resource-poor countries who face death from AIDS.

Esophageal aspiration of air through the drain tube of the ProSeal laryngeal mask.

Two patients experienced partial upper airway obstruction while breathing spontaneously with the ProSeal laryngeal mask airway. This resulted in esophageal aspiration of air through the drain tube.

Effects of helpers on juvenile development and survival in meerkats.

Although breeding success is known to increase with group size in several cooperative mammals, the mechanisms underlying these relationships are uncertain. We show that in wild groups of cooperative meerkats, Suricata suricatta, reductions in the ratio of helpers to pups depress the daily weight gain and growth of pups and the daily weight gain of helpers. Increases in the daily weight gain of pups are associated with heavier weights at independence and at 1 year of age, as well as with improved foraging success as juveniles and higher survival rates through the first year of life.

Selection for loss of p53 function in T-cell lymphomagenesis is alleviated by Moloney murine leukemia virus infection in myc transgenic mice.

Thymic lymphomas induced by Moloney murine leukemia virus (MMLV) have provided many examples of oncogene activation, but the role of tumor suppressor pathways in these tumors is less clear. These tumors display little evidence of loss of heterozygosity, and MMLV is only weakly synergistic with the Trp53 null genotype, suggesting that viral lymphomagenesis involves mechanisms which do not require mutational loss of Trp53 function. To explore this relationship in greater depth, we infected CD2-myc transgenic mice with MMLV and examined the role of Trp53 in the genesis of these tumors.

Ethanol, errors, and the speed-accuracy trade-off.

Ethanol has been shown to have a relatively greater effect on error rates in speeded tasks than temazepam, and this may be due to a differential effect on the speed-accuracy trade-off (SATO). This study used different instruction sets to influence the SATO. Forty-nine healthy volunteers (24 males, aged 18-41 years) were allocated at random to one of three instruction conditions--emphasising accuracy, neutral, and emphasising speed.

Validity and sensitivity of a pen computer battery of performance tests.

This study compared administration of performance tests and visual analogue scales (VAS) using a newly developed pen computer (PenC) battery with established tests using either pencil-and-paper (PP) or conventional computer. The performance of 47 subjects (23 male, age 18-45 years, weight 51-112 kg) was compared on the two systems after a dose of ethanol (0.8 g/kg up to a maximum of 60 g for males, 50 g for females) or placebo in a double-blind two-period randomized crossover study.

Runx2: a novel oncogenic effector revealed by in vivo complementation and retroviral tagging.

The Runx2 (Cbfa1, Pebp2alphaA, Aml3) gene was previously identified as a frequent target for transcriptional activation by proviral insertion in T-cell lymphomas of CD2-MYC transgenic mice. We have recently shown that over-expression of the full-length, most highly expressed Runx2 isoform in the thymus perturbs T-cell development, leads to development of spontaneous lymphomas at low frequency and is strongly synergistic with Myc. To gain further insight into the relationship of Runx2 to other lymphomagenic pathways, we tested the effect of combining the CD2-Runx2 transgene either with a Pim1 transgene (E(mu)-Pim1) or with the p53 null genotype, as each of these displays independent synergy with Myc.

Stimulus probability directs spatial attention: an enhancement of sensitivity in humans and monkeys.

We examined whether improvements in sensory processing, defined as changes in sensitivity, could be elicited in a simple luminance discrimination task without eliciting concomitant changes in decision processing. To this end we developed a task, for use in both humans and monkeys, in which prior knowledge about where a discriminative stimulus was likely to appear (1) offered no decisional advantage in solving our task and (2) could be parametrically varied to yield a psychometric function. We found that if we parametrically varied the quality of prior knowledge, by increasing the probability, and thus the certainty, that a discriminative stimulus would appear at a particular location under these conditions, luminance discrimination improved for both human and monkey subjects.

Evaluation of the effect of intravenous l-carnitine on quality of life in chronic hemodialysis patients.

Aim: The aim of this study was to determine the effect of l-carnitine on quality of life (QOL) in chronic hemodialysis patients.

Patients And Methods: This trial used a randomized, prospective, placebo-controlled, double-blind, crossover design. Inclusion criteria were patients who were older than 18 years, had been on dialysis for a minimum of one year, and had at least two of the following symptoms: intradialytic hypotension, muscle cramping, lack of energy, muscle weakness or myopathy, cardiomyopathy, or lack of responsiveness to erythropoietin (EPO).

Tests for cooperative behaviour between stallions.

Breeding groups with multiple stallions occur sympatrically with single-stallion breeding groups in feral horse, Equus caballus, populations. Mutualism and reciprocal altruism between stallions have been proposed to explain the origin and functioning of multistallion bands. However, empirical support for these hypotheses is contradictory and incomplete.

Pulmonary endothelial permeability and circulating neutrophil-endothelial markers in patients undergoing esophagogastrectomy.

Objective: Esophagogastrectomy is an established surgical treatment for esophageal malignancy. The postoperative period may be complicated by the development of acute lung injury syndromes and thus, may provide a useful model in which to study the early pathogenic mechanisms of inflammatory lung injury.

Design: Open, prospective study.

Individual mares bias investment in sons and daughters in relation to their condition.

The Trivers-Willard hypothesis (TWH) predicts that a mother will treat a son or daughter differently depending on her ability to invest and the impact of her investment on offspring reproductive success. Although many studies have investigated the hypothesis, few have definitively supported or refuted it because of confounding factors or an inappropriate level of analysis. We studied maternal investment in sons and daughters in feral horses, Equus caballus, which meet the assumptions of the TWH with a minimum of confounding variables.

Repair of pulmonary vein rupture after deceleration injury.

Injuries to the major pulmonary vessels are uncommon and are extremely difficult to manage. We report a case of an isolated pulmonary vein injury following a road traffic accident that was repaired successfully.

Rupture of the pectoralis major: a meta-analysis of 112 cases.

Of about 150 cases reported in the literature on pectoralis major ruptures, 108 were selected as presenting enough data to be analyzed for cause, rupture site, injury mechanism, and treatment outcome. We added data on four of our own cases reported here. All patients yet reported have been men.

Fas-independent apoptosis in T-cell tumours induced by the CD2-myc transgene.

Depending on the cellular context, the Myc oncoprotein is capable of promoting cell proliferation or death by apoptosis. These observations suggest that apoptosis in response to deregulated gene expression may represent a natural brake to tumour development. The pathways by which Myc induces apoptosis are as yet poorly characterised although recent observations on rat fibroblasts over-expressing Myc have demonstrated a requirement for the Fas pathway.

Sensitivity to myc-induced apoptosis is retained in spontaneous and transplanted lymphomas of CD2-mycER mice.

To study the effects of the Myc oncoprotein in a regulatable in vivo system, we generated lines of transgenic mice in which a tamoxifen inducible Myc fusion protein (c-mycER) is expressed under the control of the CD2 locus control region. Activation of the Myc oncoprotein resulted in both proliferation and apoptosis in vivo. Lines with a high transgene copy number developed spontaneous lymphomas at low frequency, but the tumour incidence was significantly increased with tamoxifen treatment.