Siesta and the risk of coronary heart disease: results from a population-based, case-control study in Costa Rica.
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BACKGROUND: The siesta (afternoon nap or rest), a common traditional behaviour in tropical areas, may increase the risk of myocardial infarction (MI) since the post siesta cardiovascular response very closely resembles the period soon after waking up in the morning when the onset of acute cardiovascular events is high. METHODS: We studied 505 MI survivors and 522 randomly selected controls, matched for age, gender, and area of residence, in a population-based case-control study in Costa Rica. Participation rates were 97% for cases and 90% for controls. All subjects completed a physical activity questionnaire that included occupational and leisure time components with specific questions on siesta. Five siesta frequency categories (<1/wk, 1-4/wk, 5-6/wk, daily [> or =1 h and <2 h], and daily [> or =2 h and <3:30 h]) were used to calculate the odds ratio (OR) by multiple logistic regression. RESULTS: Compared to controls, cases were more likely to take daily siestas (44 versus 35%, P = 0. 01), and spend more time per siesta (1:07 +/- 0:04 versus 0:54 +/- 0:04 h:min, P = 0.002). As compared to subjects with the lowest siesta frequency (<1/wk), the OR for MI among those in the highest category was 1.51 (95% CI : 1.02-2.25, P for trend = 0.006). After adjusting for risk factors, lifestyle, and health history the OR across the siesta categories were 1.0, 0.77, 1.28. 1.66, and 1.40 (P for trend = 0.02). CONCLUSIONS: Our data suggest that the practice of daily siesta is associated with increased risk of MI. (+info)
Virus-specific adaptations for the production of a pseudorecombinant virus formed by two distinct bipartite geminiviruses from Central America.
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Most whitefly-transmitted geminiviruses possess bipartite genomes comprising DNAs A and B. The production of viable pseudorecombinants by reassortment of infectious cloned components is generally limited to isolates/strains of a particular virus. Following exchange of cloned genomic components of Sida golden mosaic virus from Costa Rica (SiGMV/Co) and Sida golden mosaic virus from Honduras (SiGMV/Ho(yv)), the pseudorecombinant viruses were infectious in various plant species. Three DNA B components (B(1), B(2), B(3)), different in a few nucleotides, were isolated from Sida rhombifolia naturally infected with SiGMV/Ho(yv). Only SiGMV/Ho(yv) DNA B(2) was able to form a viable pseudorecombinant with SiGMV/Co DNA A. In protoplasts, as well as in inoculated leaves, SiGMV/Co DNA A trans-replicated the heterogenomic SiGMV/Ho(yv) DNA B(1) component, indicating that impaired movement is involved in the deficiency of SiGMV/Ho(yv) DNA B(1) to form a pseudorecombinant virus with SiGMV/Co DNA A. Even after extensive mutation analysis of SiGMV/Ho(yv) DNA B(1) and B(2), we were unable to pinpoint differences in SiGMV/Ho(yv) DNA B(2) that allowed the formation of a pseudorecombinant virus with SiGMV/Co DNA A. We observed a gradual increase of infectivity from noninfectious SiGMV/Co DNA A/SiGMV/Ho(yv) DNA B(1) and B(3) pseudorecombinant virus to pseudorecombinant viruses showing normal systemic spread of both genomic components associated with symptomatic plants. (+info)
Neopolystoma fentoni n. sp. (Monogenea: Polystomatidae) a parasite of the conjunctival sac of freshwater turtles in Costa Rica.
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Neopolystoma fentoni n. sp. is described from the conjunctival sac of Kinosternon leucostomum (Dumeril, Bibron, and Dumeril 1851) and Rhinoclemmys pulcherrima (Gray 1855) from the Guanacaste Conservation Area in Costa Rica. The new species differs from all other species of Neopolystoma, except N. elizabethae Platt 2000 in possessing a circle of eight genital spines that are recurved and possess a crescent-shaped base. N. fentoni n. sp. differs from N. elizabethae in lacking cecal diverticula and in a number of morphometric criteria. (+info)
A second locus for an axonal form of autosomal recessive Charcot-Marie-Tooth disease maps to chromosome 19q13.3.
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Autosomal recessive Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of disorders affecting the peripheral nervous system. The axonal form of the disease is designated as "CMT type 2" (CMT2), and one locus (1q21.2-q21.3) has been reported for the autosomal recessive form. Here we report the results of a genomewide search in an inbred Costa Rican family (CR-1) affected with autosomal recessive CMT2. By analyzing three branches of the family we detected linkage to the 19q13.3 region, and subsequent homozygosity mapping defined shared haplotypes between markers D19S902 and D19S907 in a 5.5-cM range. A maximum two-point LOD score of 9.08 was obtained for marker D19S867, at a recombination fraction of.00, which strongly supports linkage to this locus. The epithelial membrane protein 3 gene, encoding a PMP22 homologous protein and located on 19q13.3, was ruled out as being responsible for this form of CMT. The age at onset of chronic symmetric sensory-motor polyneuropathy was 28-42 years (mean 33.8 years); the electrophysiological data clearly reflect an axonal degenerative process. The phenotype and locus are different from those of demyelinating CMT4F, recently mapped to 19q13.1-13.3; hence, the disease affecting the Costa Rican family constitutes an axonal, autosomal recessive CMT subtype (ARCMT2B). (+info)
Composition and gene expression of the cag pathogenicity island in Helicobacter pylori strains isolated from gastric carcinoma and gastritis patients in Costa Rica.
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The composition and in vitro expression of the cag pathogenicity island genes in a group of Helicobacter pylori strains obtained from patients suffering from chronic gastritis-associated dyspepsia (n = 26) or gastric carcinoma (n = 17) were analyzed. No significant difference in the distribution of the 10 studied regions was found between the cases and the controls. Nine strains did not harbor any of the selected regions: eight (30.8%) isolated from patients with gastritis only and one (5.9%) from a patient with gastric carcinoma. No association was found between the number of repeated sequences at the 3' end of the cagA gene or the presence of tyrosine phosphorylation motifs and the clinical origin of the strains. The virB10 homolog gene was the sole gene studied to be significantly expressed more often in cancer strains than in gastritis strains (P = 0.03). (+info)
Linkage analysis of a complex pedigree with severe bipolar disorder, using a Markov chain Monte Carlo method.
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Recently developed algorithms permit nonparametric linkage analysis of large, complex pedigrees with multiple inbreeding loops. We have used one such algorithm, implemented in the package SimWalk2, to reanalyze previously published genome-screen data from a Costa Rican kindred segregating for severe bipolar disorder. Our results are consistent with previous linkage findings on chromosome 18 and suggest a new locus on chromosome 5 that was not identified using traditional linkage analysis. (+info)
Population genetic structure and vocal dialects in an amazon parrot.
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The relationship between cultural and genetic evolution was examined in the yellow-naped amazon Amazona auropalliata. This species has previously been shown to have regional dialects defined by large shifts in the acoustic structure of its learned contact call. Mitochondrial DNA sequence variation from a 680 base pair segment of the first domain of the control region was assayed in 41 samples collected from two neighbouring dialects in Costa Rica. The relationship of genetic variation to vocal variation was examined using haplotype analysis, genetic distance analysis, a maximum-likelihood estimator of migration rates and phylogenetic reconstructions. All analyses indicated a high degree of gene flow and, thus, individual dispersal across dialect boundaries. Calls sampled from sound libraries suggested that temporally stable contact call dialects occur throughout the range of the yellow-naped amazon, while the presence of similar dialects in the sister species Amazona ochrocephala suggests that the propensity to form dialects is ancestral in this clade. These results indicate that genes and culture are not closely associated in the yellow-naped amazon. Rather, they suggest that regional diversity in vocalizations is maintained by selective pressures that promote social learning and allow individual repertoires to conform to local call types. (+info)
Estimating risks in declining populations with poor data.
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Census data on endangered species are often sparse, error-ridden, and confined to only a segment of the population. Estimating trends and extinction risks using this type of data presents numerous difficulties. In particular, the estimate of the variation in year-to-year transitions in population size (the "process error" caused by stochasticity in survivorship and fecundities) is confounded by the addition of high sampling error variation. In addition, the year-to-year variability in the segment of the population that is sampled may be quite different from the population variability that one is trying to estimate. The combined effect of severe sampling error and age- or stage-specific counts leads to severe biases in estimates of population-level parameters. I present an estimation method that circumvents the problem of age- or stage-specific counts and is markedly robust to severe sampling error. This method allows the estimation of environmental variation and population trends for extinction-risk analyses using corrupted census counts--a common type of data for endangered species that has hitherto been relatively unusable for these analyses. (+info)