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Biomedical subjects

S Edwards

Publications and source records attributed to S Edwards.

At least 91 records · Page 5Linked to original sources
PubMed1997

Hormone replacement therapy, reproductive history, and colon cancer: a multicenter, case-control study in the United States.

Hormonal factors have been inconsistently associated with colon cancer risk in women. The associations between reproductive events, menstrual factors, exogenous hormones, and colon cancer were evaluated in a large case-control study (894 female cases and 1,120 female age-matched population-based controls) in the United States, stratifying by age at diagnosis, tumor site, family history and other potential risk factors. Overall, higher parity was associated with a marginally decreased risk of colon cancer (five or more births compared with nulliparous: odds ratio [OR] = 0.75, 95 percent confidence interval [CI] = 0.53-1.06) after adjusting for age at diagnosis, family history of colorectal cancer, vigorous lifetime physical activity, body mass index (BMI) (wt/ht1.5), total energy intake, and aspirin use. No important associations were observed for other reproductive or menstrual events. An inverse association between recent use of hormone replacement therapy (HRT) and colon cancer was observed (OR = 0.71, CI = 0.56-0.89). Although interaction terms were not significant, this inverse association appeared to be more pronounced for those with an older age at diagnosis; for those without a first-degree relative with colorectal cancer; and for those with a relatively low BMI. The reduced risk associated with HRT use did not appear to be explained by other behaviors related to HRT use.

Adult↗
PubMed1997

Localised oral histoplasmosis lesions associated with HIV infection.

Opportunistic fungal infections account for a significant amount of morbidity associated with HIV disease. We report here a case of localised oral histoplasmosis without evidence of disseminated disease in a patient who lacked stigmata of HIV disease at the time of initial presentation. The diagnosis is based on histology with special stains, complement fixing antibodies in serum, and culture of the organism from fresh tissues. Activation of subclinical disease following an infection in Uganda may explain the development of these exophytic oral lesions in this British resident.

AIDS-Related Opportunistic Infections↗
PubMed1997

The effect of botulinum toxin on hand function after incomplete spinal cord injury at the level of C5/6: a case report.

OBJECTIVE: To investigate the benefits of the focal use of botulinum toxin in spasticity in the forearm seen after incomplete spinal cord injury. DESIGN: A single case study with standardized assessment before and at three-week intervals after injection. INTERVENTION: EMG-guided selective injection of botulinum toxin. SUBJECT: A 23-year-old man, 18 months post injury. MEASURES: Rivermead Motor Assessment; grip strength; Jebsen hand tests; visual analogue scale; Ashworth spasticity scale. RESULTS: Weakness was seen as expected with some functional losses, but the patient made gains in the areas of concern: shaking hands, typing, using the hand to drink. These gains were sustained at 12 weeks. CONCLUSION: Selective use of botulinum toxin to weaken muscles can lead to functional benefit.

Adult↗
PubMed1997

Life stressors, neighborhood disadvantage, and resources: a focus on inner-city children's adjustment.

Examined the contribution of particular stressors and resources to inner-city children's adjustment. Fourth, 5th, and 6th graders (N = 315; 66% from ethnic minority groups) reported on their recent exposure to stressful events and neighborhood disadvantage, their perceptions of self-worth and social support, and their behavioral and academic adjustment. Hierarchical regressions indicated unique contributions of stressful events and neighborhood disadvantage to predicting antisocial behavior; higher levels of self-worth and family support were related to lower levels of antisocial behavior, but higher levels of peer support were related to higher levels of antisocial behavior. Furthermore, whereas family support buffered the relation between stressful events and antisocial behavior, peer support exacerbated the effect of stressors on behavioral maladjustment.

Achievement↗
PubMed1997

Recording blood pressure.

The blood pressure can reveal much about a patient's state of health. A number of variables can affect blood pressure measurement.

Blood Pressure↗
PubMed1996

A description of age, sex, and site distributions of colon carcinoma in three geographic areas.

BACKGROUND: Site of the carcinoma within the colon in relation to age and sex may provide clues into the etiology of the disease. Incidence of colon carcinoma by age, sex, and tumor site at a population-based level are reported infrequently. The goal of this study was to describe the distribution of colon carcinoma (excluding cancers of the rectosigmoid junction and rectum) by age at diagnosis, sex, and site of the tumor within the colon. These factors were also evaluated in conjunction with disease stage at the time of diagnosis. METHODS: Data from three geographically distinct populations were used to describe rates of colon carcinoma and the distribution of tumors by age, tumor site, and stage at diagnosis. All colon carcinoma cases diagnosed within a 3-year period within the areas are included. RESULTS: Approximately 50% of all cancers in men and greater than 50% of cancers in women were in the proximal segment of the colon. Men who were diagnosed prior to age 50 and both men and women diagnosed at age 70 or older had predominantly proximal cancers. People with proximal cancers and people diagnosed prior to age 50 were more likely to have more advanced disease. CONCLUSIONS: Both men and women have more proximal cancers with advancing age, which are associated with more advanced disease. Observed trends in cancer site distributions could reflect screening practices, environmental and genetic factors, or a combination of these variables.

Adult↗
PubMed1996

Molecular, functional and evolutionary characterization of the gene encoding HMG-CoA reductase in the fission yeast, Schizosaccharomyces pombe.

The synthesis of mevalonate, a molecule required for both sterol and isoprene biosynthesis in eukaryotes, is catalysed by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Using a gene dosage approach, we have isolated the gene encoding HMG-CoA reductase hmgl+, from the fission yeast Schizosaccharomyces pombe (Accession Number L76979). Specifically, hmgl+ was isolated on the basis of its ability to confer resistance to lovastatin, a competitive inhibitor of HMG-CoA reductase. Gene disruption analysis showed that hmgl+ was an essential gene. This result provided evidence that, unlike Saccharomyces cerevisiae, S. pombe contained only a single functional HMG-CoA reductase gene. The presence of a single HMG-CoA reductase gene was confirmed by genomic hybridization analysis. As observed for the S. cerevisiae HMGlp, the hmgl+ protein induced membrane proliferations known as karmellae. A previously undescribed 'feed-forward' regulation was observed in which elevated levels of HMG-CoA synthase, the enzyme catalysing the synthesis of the HMG-CoA reductase substrate, induced elevated levels of hmgl+ protein in the cell and conferred partial resistance to lovastatin. The amino acid sequences of yeast and human HMG-CoA reductase were highly divergent in the membrane domains, but were extensively conserved in the catalytic domains. We tested whether the gene duplication that produced the two functional genes in S. cerevisiae occurred before or after S. pombe and S. cerevisiae diverged by comparing the log likelihoods of trees specified by these hypotheses. We found that the tree specifying post-divergence duplication had significantly higher likelihood. Moreover, phylogenetic analyses of available HMG-CoA reductase sequences also suggested that the lineages of S. pombe and S. cerevisiae diverged approximately 420 million years ago but that the duplication event that produced two HMG-CoA reductase genes in the budding yeast occurred only approximately 56 million years ago. To date, S. pombe is the only unicellular eukaryote that has been found to contain a single HMG-CoA reductase gene. Consequently, S. pombe may provide important opportunities to study aspects of the regulation of sterol biosynthesis that have been difficult to address in other organisms and serve as a test organism to identify novel therapies for modulating cholesterol synthesis.

Amino Acid Sequence↗
PubMed1996

Beneficial effects of RheothRx injection in patients receiving thrombolytic therapy for acute myocardial infarction. Results of a randomized, double-blind, placebo-controlled trial.

BACKGROUND: RheothRx (poloxamer 188) is a surfactant with hemorheological and antithrombotic properties that reduces myocardial reperfusion injury in animal models of myocardial infarction. The purpose of the present study was to evaluate the safety and efficacy of adjunctive therapy with poloxamer 188 in patients receiving thrombolytic therapy for acute myocardial infarction. METHODS AND RESULTS: In this multicenter trial, we randomized 114 patients to a 48-hour infusion of poloxamer 188 or vehicle placebo beginning immediately after the initiation of thrombolytic therapy. Tomographic imaging with 99mTc sestamibi before reperfusion and again 5 to 7 days after the infarction was used to determine myocardium at risk for infarction, infarct size, and myocardial salvage. Radionuclide angiography at 5 to 7 days after infarction was used to measure left ventricular ejection fraction. The treated and control groups had comparable baseline characteristics, time to thrombolytic administration, and time to treatment with poloxamer 188 or placebo. Poloxamer 188-treated patients demonstrated a 38% reduction in median myocardial infarct size (25th and 75th percentile) compared with placebo (16% [7, 30] versus 26% [9, 43]; P = .031), greater median myocardial salvage (13% [7, 20] versus 4% [1, 15]; P = .033), and a 13% relative improvement in median ejection fraction (52% [43, 60] versus 46% [35, 60]; P = .020). Poloxamer 188 treatment also resulted in a reduced incidence of reinfarction (1% versus 13%; P = .016). Poloxamer 188 was well tolerated without adverse hemodynamic effects or significant organ toxicity. CONCLUSIONS: Adjunctive therapy with poloxamer 188 resulted in substantial benefit in this randomized trial, including significantly smaller infarcts, greater myocardial salvage, better left ventricular function, and a lower incidence of in-hospital reinfarction. Although the mechanisms are unproven, poloxamer 188 treatment may accelerate thrombolysis, reduce reocclusion, and ameliorate reperfusion injury.

Adult↗
PubMed1996

Enhanced secretory ability for the human factor VIII light chain produced in baculovirus-infected insect cells.

The light and truncated heavy chains of human factor VIII, expressed separately in baculovirus-infected insect cells, exhibited different secretory behaviour when compared with each other and with a biologically active fusion molecule of the truncated heavy and light chains. The light chain was very efficiently secreted into culture medium, as judged by high extracellular protein levels and the absence of evidence for light chain retention within cells. Alternatively, proteins containing the heavy chain sequence were poorly secreted and appeared to be sequestered within cells, suggesting that regions within the heavy chain are responsible for the low levels of secreted protein which have generally been observed for recombinant factor VIII.

Animals↗
PubMed1996

A demonstration of virtual reality in free-flying honeybees: Apis mellifera.

Two experiments are reported on virtual reality illusion in free-flying honeybees. In the first experiment, subjects are trained on a simultaneous discrimination between two colored targets, one of which contains a sucrose reward. The ability to be influenced by a virtual reality illusion was assessed during an extinction test in which the training stimuli were a mirage of those used during acquisition. The results indicate that the bees consistently attempt to land on the previously rewarded color despite the fact that it is not there. In a second experiment, bees were unable to discriminate between two simultaneously presented, identically colored targets--one of which was real, the other a mirage.

Animals↗
PubMed1996

Effects of caffeine, practice, and mode of presentation on Stroop task performance.

A series of experiments were designed to investigate the effects of 125 and 250 mg caffeine, or placebo, on performance of the Stroop task. Caffeine had no effect on performance of either the classic colour-word version or a numerical version of the task, either using computerised presentation of the stimuli or a traditional card version. However, significant practice effects were found using a within-subjects design with the card version of the task, and differences were found between performance in the card and computerised versions of the task. It is concluded that at these doses, caffeine does not significantly affect Stroop performance. It is also suggested that practice effects in studies using within-subject designs may be a problem when attempting to detect subtle effects of drugs on cognitive performance, and that the computerised version of the Stroop task may not be an exact analogue of the traditional card version.

Adolescent↗
PubMed1996

Antibody isotype responses to experimental infection with bovine herpesvirus 1 in calves with colostrally derived antibody.

Calves, both positive and negative for maternal antibody to bovine herpesvirus 1 (BHV-1), were infected with BHV-1 and their serum antibody isotype responses were measured post-infection. In the case of maternal antibody negative calves there was a classical humoral response to the virus with an early IgM peak followed by IgG1 and IgG2 responses. In maternal antibody positive calves, although infection was established, no active antibody response was detected in serum except for a transient IgM peak in a single calf. By contrast, a delayed-type hypersensitivity test response could be elicited in both groups of calves by intradermal inoculation of nucleocapsid antigen at 4.5 months after the initial infection. The intradermal antigen also stimulated an antibody response. In calves with high levels of maternal antibody at the start of the experiment, and which were not subsequently infected, maternal antibody waned to negative levels by seven months of age. They were skin test negative and did not show a serological response to skin test antigen. It was concluded that isotype specific serology could not be used to distinguish calves with passive immunity to BHV-1 from those with active immunity and putative latent infection. Although the skin test had potential to provide such a distinction, it could compromise future serological monitoring of the animals.

Animals↗