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Biomedical subjects

S Lewis

Publications and source records attributed to S Lewis.

At least 91 records · Page 5Linked to original sources
PubMed2001

A case-control study of risk factors for asthma in New Zealand children.

OBJECTIVE: As in other English-speaking countries, asthma is a major and increasing health problem in New Zealand. This study examined the risk factors for asthma in children aged 7-9. METHODS: Cases and controls were randomly selected from participants in the Wellington arm of the International Study of Asthma and Allergies in Childhood (ISAAC). Cases were children with a previous diagnosis of asthma and current medication use (n=233), and controls were children with no history of wheezing and no diagnosis of asthma (n=241). RESULTS: After controlling for confounders, factors significantly associated with asthma were maternal (OR=3.36, 95% CI 1.88-5.99) and paternal asthma (OR-2.67, 95% CI 1.42-5.02), and male sex (OR=1.81, 95% CI 1.17-2.81). Children from social classes 5 and 6 or with unemployed parents (OR=2.32, 95% CI 1.22-4.44) were significantly more likely to have asthma than children in social classes 1 and 2. There was no significant association between having polio vaccination (OR=2.48, 95% CI 0.83-7.41), hepatitis B vaccination (OR=0.66, 95% CI 0.42-1.04) or measles/mumps/rubella vaccination (OR=1.43, 95% CI 0.85-2.41) and asthma. CONCLUSIONS: This study has confirmed the associations of family history and lower socio-economic status with current asthma in 7-9 year old children. The role of vaccinations requires further research.

Asthma↗
PubMed2001

Risk of early death and recurrent stroke and effect of heparin in 3169 patients with acute ischemic stroke and atrial fibrillation in the International Stroke Trial.

BACKGROUND AND PURPOSE: We sought to investigate the apparently high risk of early death after an ischemic stroke among patients with atrial fibrillation (AF), identify the main factors associated with early death, and assess the effect of treatment with different doses of subcutaneous unfractionated heparin (UFH) given within 48 hours. METHODS: We studied the occurrence of major clinical events within 14 days among 18 451 patients from the International Stroke Trial, first for all treatment groups combined. Then, among patients with AF, we examined the effects of treatment with subcutaneous UFH started within 48 hours and continued until 14 days after stroke onset. RESULTS: A total of 3169 patients (17%) had AF. Seven hundred eighty-four patients were allocated to UFH 12 500 IU SC BID, 773 to UFH 5000 IU SC BID, and 1612 to no heparin. Within each of these groups, half of the patients were randomly assigned to aspirin 300 mg once daily. Compared with patients without AF, patients with AF were more likely to be female (56% versus 45%), to be old (mean age, 78 versus 71 years), to have an infarct on prerandomization CT (57% versus 47%), and to have impaired consciousness (37% versus 20%). The initial ischemic stroke type was more often a large-artery infarct (36% versus 21%). A lacunar stroke syndrome was less common (13% versus 26%). Death within 14 days was more common in patients with AF (17% versus 8%) and more often attributed to neurological damage from the initial stroke (10% versus 4%). The frequency of recurrent ischemic or undefined stroke was not significantly different (3.9% versus 3.3%). The proportion of AF patients with further events within 14 days allocated to UFH 12 500 IU (n=784), UFH 5000 IU (n=773), and to no-heparin (n=1612) groups were as follows: ischemic stroke, 2.3%, 3.4%, 4.9% (P=0.001); hemorrhagic stroke, 2.8%, 1.3%, 0.4% (P<0.0001); and any stroke or death, 18.8%, 19.4% and 20.7% (P=0.3), respectively. No effect of heparin on the proportion of patients dead or dependent at 6 months was apparent. CONCLUSIONS: Acute ischemic stroke patients with AF have a higher risk of early death, which can be explained by older age and larger infarcts but not by a higher risk of early recurrent ischemic stroke, although slightly more patients with AF died from a fatal recurrent stroke of ischemic or unknown type (1.3% versus 0.9%). In patients with AF the absolute risk of early recurrent stroke is low, and there is no net advantage to treatment with heparin. These data do not support the widespread use of intensive heparin regimens in the acute phase of ischemic stroke associated with AF.

Acute Disease↗
PubMed2000

2-Aryl tryptamines: selective high-affinity antagonists for the h5-HT2A receptor.

A series of 2-aryl tryptamines have been identified as high-affinity h5-HT2A antagonists. Structure-activity relationship studies have shown that h5-HT2A affinity can be attained via modifications to the tryptamine side chain and that selectivity over h5-HT2C and hD2 receptors can be controlled by suitable C-2 aryl groups.

Animals↗
PubMed2000

Dietary vitamin E, IgE concentrations, and atopy.

Vitamin E inhibits IgE responses to allergic stimuli in animals. We investigated the relation between dietary vitamin E intake and serum IgE concentrations and atopy, measured as allergen skin sensitisation, in a random sample of 2633 adults. Higher concentrations of vitamin E intake were associated with lower serum IgE concentrations and a lower frequency of allergen sensitisation. These findings may explain the beneficial effect of dietary vitamin E on the incidence of asthma.

Adult↗
PubMed2000

Avoidance of drilled gastropod shells by the hermit crab Pagurus longicarpus at Nahant, Massachusetts.

Most hermit crabs depend on empty gastropod shells for shelter; competition for appropriate shells is often severe. This study determined whether shells that have been drilled by naticid gastropods are suitable for occupancy by the hermit crab Pagurus longicarpus. Differences in the characteristics of empty shells and those occupied by hermit crabs were assessed at two adjacent field sites in Nahant, Massachusetts. Drilling damage was far more frequent in empty gastropod shells than in shells occupied by hermit crabs, suggesting that individuals of P. longicarpus avoid drilled shells. They did not appear to avoid shells with other forms of damage. Laboratory experiments confirmed that these hermit crabs preferentially chose intact shells over drilled shells, even when the intact shells offered were most suitable for crabs half the weight of those tested. Final shell choices were generally made within 1 h. The hermit crabs apparently discriminated between intact and drilled shells based on tactile cues, since crabs kept in the dark showed the same preference for intact shells. The hermit crabs strongly avoided, to nearly the same extent, artificially drilled shells, naturally drilled shells, and shells with holes artificially drilled on the opposite side of the shell from where they would normally be located. Possible selective forces causing P. longicarpus to show such strong behavioral avoidance of drilled shells include increased vulnerability of crabs in drilled shells to osmotic stress, predation, and eviction by conspecifics.

Journal Article↗
PubMed2000

Comparative genomics of the eukaryotes.

A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.

Animals↗
PubMed2000

Risk of cryptogenic fibrosing alveolitis in metal workers.

We report increased proportional mortality from cryptogenic fibrosing alveolitis in the workforce of a major UK engineering company. Measures of metal exposure from unbiased historical occupational records showed that among employees who have worked with metal, the risk of death from or with cryptogenic fibrosing alveolitis increased in relation to the duration of metal-working.

Aged↗
PubMed2000

A comparison of the morphology of testicular, epididymal, and ejaculated sperm from fertile men and men with obstructive azoospermia.

OBJECTIVE: To assess the morphology of testicular, epididymal, and ejaculated sperm. DESIGN: Morphology of the three types of sperm was assessed by using Tygerberg strict criteria. SETTING: The Regional Fertility Center, Royal Maternity Hospital, Belfast, Northern Ireland, United Kingdom. PATIENT(S): Thirty-two men with obstructive azoospermia and 10 fertile men. INTERVENTION(S): Trucut needle testicular biopsy and percutaneous epididymal sperm aspiration under local anesthetic. MAIN OUTCOME MEASURE(S): Percentages of normal sperm and sperm with head, midpiece, and tail defects for testicular, epididymal, and ejaculated sperm. Testicular sperm morphology in men with obstructive azoospermia was compared with that of fertile men. RESULT(S): The percentage of normal testicular sperm (4.3%) differed significantly from the percentages of normal epididymal (10. 8%) and ejaculated sperm (9.6%). Testicular sperm morphology in men with obstructive azoospermia did not differ from that in fertile men. CONCLUSION(S): Tygerberg strict criteria are not suitable for the assessment of testicular sperm morphology.

Ejaculation↗
PubMed2000

Editorial

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Journal Article↗
PubMed2000

Annotating eukaryote genomes.

The Genome Annotation Assessment Project tested current methods of gene identification, including a critical assessment of the accuracy of different methods. Two new databases have provided new resources for gene annotation: these are the InterPro database of protein domains and motifs, and the Gene Ontology database for terms that describe the molecular functions and biological roles of gene products. Efforts in genome annotation are most often based upon advances in computer systems that are specifically designed to deal with the tremendous amounts of data being generated by current sequencing projects. These efforts in analysis are being linked to new ways of visualizing computationally annotated genomes.

Animals↗