932 resultados para RECENT HUMAN-EVOLUTION


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Polyphenols represent a group of chemical substances common in plants, structurally characterized by the presence of one or more phenol units. Polyphenols are the most abundant antioxidants in human diets and the largest and best studied class of polyphenols is flavonoids, which include several thousand compounds. Numerous studies confirm that they exert a protective action on human health and are key components of a healthy and balanced diet. Epidemiological studies correlate flavonoid intake with a reduced incidence of chronic diseases, such as cardiovascular disease, diabetes and cancer. The involvement of reactive oxygen species (ROS) in the etiology of these degenerative conditions has suggested that phytochemicals showing antioxidant activity may contribute to the prevention of these pathologies. The present review deals with phenolic compounds in plants and reports on recent studies. Moreover, the present work includes information on the relationships between the consumption of these compounds, via feeding, and risk of disease occurrence, i.e. the effect on human health. Results obtained on herbs, essential oils, from plants grown in tropical, subtropical and temperate regions, were also reported.

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This literature review analyzes David Buss' evolutionary theory of emotions, which addresses some possible hindrances to positive emotions in today's society. The social function of emotions, sustained happiness, and competition will be looked at in comparison to Buss' article. Buss' theory will then be analyzed to the extent it applies to the human condition today. This review is not exhaustive but merely a brief analysis.

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Background: The complex natural history of human papillomavirus (HPV) infections following a single HPV test can be modeled as competing-risks events (i.e., no-, transient- or persistent infection) in a longitudinal setting. The covariates associated with these compet ng events have not been previously assessed using competing-risks regression models. Objectives: To gain further insights in the outcomes of cervical HPV infections, we used univariate- and multivariate competing-risks regression models to assess the covariaies associated with these competing events. Study Design and Methods: Covariates associated with three competing outcomes (no-, transient- or persistent HR-HPV infection) were analysed in a sub-cohort of 1,865 women prospectively followed-up in the NIS (n = 3,187) and LAMS Study (n = 12,114). Results: In multivariate competing-risks models (with two other outcomes as competing events), permanently HR-HPV negative outcome was significantly predicted only by the clearance of ASCUS+Pap during FU, while three independent covariates predicted transient HR-HPV infections: i) number of recent (< 12 months) sexual partners (risk increased), ii) previous Pap screening history (protective), and history of previous CIN (increased risk). The two most powerful predictors of persistent HR-HPV infections were persistent ASCUS+Pap (risk increased), and previous Pap screening history (protective). In pair-wise comparisons, number of recent sexual partners and previous CIN history increase the probability of transient HR-HPV infection against the HR-HPV negative competing event, while previous Pap screening history is protective. Persistent ASCUS+Pap during FU and no previous Pap screening history are significantly associated with the persistent HR-HPV outcome (compared both with i) always negative, and ii) transient events), whereas multiparity is protective. Conclusions: Different covariates are associated with the three main outcomes of cervical HPV infections. The most significant covariates of each competing events are probably distinct enough to enable constructing of a risk-profile for each main outcome.

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Recent studies indicate that ascidians are efficiently dispersed by human transport. We have chosen the mitochondrial gene cytochrome c oxidase subunit I (COI) to address whether Clavelina oblonga is an introduced species in the Brazilian coast. Colonies of C. oblonga were sampled in different localities along Atlantic coasts of USA, Panama, and Brazil. The sequencing of 92 colonies resulted in three haplotypes for the species, two unique to Florida and the other shared by exemplars collected in Brazil and Panama; the latter haplotype is identical to the published sequence of Azores. Our evidence, including the absence of C. oblonga in the country's northern tropical waters, its association with artificial habitats and lack of COI variation suggest that the species has been introduced in the southeastern and southern Brazilian coasts. Previous records (85 years old) suggest that it could be a relatively long-term introduction.

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Glucose, an almost universally used energy and carbon source, is processed through several well-known metabolic pathways, primarily glycolysis. Glucose uptake is considered to be the first step in glycolysis. In kinetoplastids, a protozoan group that includes relevant human pathogens, the importance of glucose uptake in different phases of the life cycles is well established, and hexose transporters have been proposed as targets for therapeutic drugs. However, little is known about the evolutionary history of these hexose transporters. Hexose transporters contain an intracellular N- and C-termini, and 12 transmembrane spans connected by alternate intracellular and extracellular loops. In the present work we tested the hypothesis that the evolutionary rate of the transmembrane span is different from that of the whole sequence and that it is possible to define evolutionary units inside the sequence. The phylogeny of whole molecules was compared to that of their transmembrane spans and the loops connecting the transmembrane spans. We show that the evolutionary units in these proteins primarily consist of clustered rather than individual transmembrane spans. These analyses demonstrate that there are evolutionary constraints on the organization of these proteins; more specifically, the order of the transmembrane spans along the protein is highly conserved. Finally, we defined a signature sequence for the identification of kinetoplastid hexose transporters.

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The non-classical human leukocyte antigen (HLA) class I genes present a very low rate of variation. So far, only 10 HLA-E alleles encoding three proteins have been described, but only two are frequently found in worldwide populations. Because of its historical background, Brazilians are very suitable for population genetic studies. Therefore, 104 bone marrow donors from Brazil were evaluated for HLA-E exons 14. Seven variation sites were found, including two known single nucleotide polymorphisms (SNPs) at positions +424 and +756 and five new SNPs at positions +170 (intron 1), +1294 (intron 3), +1625, +1645 and +1857 (exon 4). Haplotyping analysis did show eight haplotypes, three of them known as E*01:01:01, E*01:03:01 and E*01:03:02:01 and five HLA-E new alleles that carry the new variation sites. The HLA-E*01:01:01 allele was the predominant haplotype (62.50%), followed by E*01:03:02:01 (24.52%). Selective neutrality tests have disclosed an interesting pattern of selective pressures in which balancing selection is probably shaping allele frequency distributions at an SNP at exon 3 (codon 107), sequence diversity at exon 4 and the non-coding regions is facing significant purifying pressure. Even in an admixed population such as the Brazilian one, the HLA-E locus is very conserved, presenting few polymorphic SNPs in the coding region.

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BACKGROUND: Brazilian blood centers ask candidate blood donors about the number of sexual partners in the past 12 months. Candidates who report a number over the limit are deferred. We studied the implications of this practice on blood safety. STUDY DESIGN AND METHODS: We analyzed demographic characteristics, number of heterosexual partners, and disease marker rates among 689,868 donations from three Brazilian centers between July 2007 and December 2009. Donors were grouped based on maximum number of partners allowed in the past 12 months for each center. Chi-square and logistic regression analysis were conducted to examine associations between demographic characteristics, number of sex partners, and individual and overall positive markers rates for human immunodeficiency virus (HIV), human T-lymphotropic virus Types 1 and 2, hepatitis B virus, hepatitis C virus, and syphilis. RESULTS: First-time, younger, and more educated donors were associated with a higher number of recent sexual partners, as was male sex in Sao Paulo and Recife (p < 0.001). Serologic markers for HIV and syphilis and overall were associated with multiple partners in Sao Paulo and Recife (p < 0.001), but not in Belo Horizonte (p = 0.05, p = 0.94, and p = 0.75, respectively). In logistic regression analysis, number of recent sexual partners was associated with positive serologic markers (adjusted odds ratio [AOR], 1.2-1.5), especially HIV (AOR, 1.9-4.4). CONCLUSIONS: Number of recent heterosexual partners was associated with HIV positivity and overall rates of serologic markers of sexually transmitted infections. The association was not consistent across centers, making it difficult to define the best cutoff value. These findings suggest the use of recent heterosexual contacts as a potentially important deferral criterion to improve blood safety in Brazil.

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The distribution of heavy metals in recent sediments deposited along the Tiete River, a highly polluted river in southeast region of Brazil was studied. Around the metropolitan area of Silo Paulo city (25 million people), the pollution is related to municipal wastes and industrial effluents with reinforced downstream by agricultural activities. The observed increase of heavy metal concentrations is particularly important for Zn in the upper basin and Cu, Co and Cr at mouth. Geo-accumulation index calculation, related to the regional background, showed that the sediments along the basin are seriously polluted by heavy metals of anthropogenic origin, mainly Cu, Co, Cr and Zn. Calculated index suggests medium to very strongly pollution.

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Access to fluoridated water is a known protective factor against dental caries. In 1974, fluoridation of the public water supply became mandatory by law in Brazil, resulting in improved coverage, especially in more developed regions of the country. Coverage increased across the country as a priority under the national oral health policy. This article systematizes information on the implementation and expansion of fluoridation in Sao Paulo State from 1956 to 2009, using secondary data from technical reports, official documents, and the Information System for Surveillance of Water Quality for Human Consumption (SISAGUA). In 2009, fluoridation covered 546 of 645 counties in Sao Paulo State (84.7%), reaching 85.1% of the total population and 93.5% of the population with access to the public water supply. The results indicate that fluoridation has been consolidated as part of State health policy. However, the challenge remains to implement and maintain fluoridation in 99 counties, benefiting 6.2 million inhabitants that are still excluded from this service.

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The study of "jellyfish blooms" provides important data toward determining the causes and consequences of these phenomena; however, the definition of "bloom" remains controversial and different concepts have been adopted in recent works. By addressing the biological and convenience definitions, this study tested the adequacy of the different concepts of "blooms" for the Class Staurozoa (Cnidaria). From seasonal monitoring data of some species of Staurozoa, we concluded that stauromedusae bloom if we used the biological concept of "bloom", which considers the life cycle and resulting changes in the abundances of these animals. By contrast, the small, benthic, inconspicuous, and non-harmful stauromedusae do not bloom if we use the convenience concept of "bloom", which constrains the events to those that humans can observe and that cause damage to human activities. In other words, the same group of organisms either is or is not capable of blooming depending on which concept of "bloom" is used. In fact, previous literature has suggested that Staurozoa could not bloom, which indicates that the study of "jellyfish blooms" can be biased, considering convenience rather than biological reasoning.

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Male squid produce intricate spermatophores that, when transferred to the female, undergo the spermatophoric reaction, a complex process of evagination that leads to the attachment of the spermatangium, that is, the everted spermatophore containing the sperm mass. While this process is still not completely understood, the medical literature includes several reports of "oral stinging" (i.e., punctured wounds in the human oral cavity) following consumption of raw male squid, which contains undischarged spermatophores able to inflict such wounds. Here, we revisit a recent medical report of oral stinging by Shiraki et al. (Pathol Int 61:749-751, 2011), providing an in-depth reanalysis of their histological biopsies and revealing vital information on the functioning of squid spermatophores. The morphology of the spermatangia attached within the oral cavity is similar to the condition found in spermatangia naturally attached to female squids. The spermatangia were able to superficially puncture the superficial layers of the oral stratified squamous epithelium, and numerous, minute stellate particles from the squid spermatophore were found adhered to the oral epithelium. These findings corroborate previous hypotheses on the functioning of squid spermatophores, namely that spermatophore attachment generally involves tissue scarification, and that stellate particles play a vital role in the attachment process. Moreover, spermatophore attachment is confirmed to be autonomous (i.e., performed by the spermatophore itself) in another squid species (possibly a loliginid), and the results strongly indicate that the attachment mechanism is not dependent upon a specialized epithelium, nor a mate's specific chemical stimulus. From the pathological point of view, the best prophylactic measure at present is the removal of the internal organs of the raw squid prior to its consumption.

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We describe a new species of Bothrops from Vitoria Island, off the coast of Sao Paulo, southeastern Brazil. The new species differs from the mainland coastal populations of B. jararaca mostly in its smaller and stouter body, number and form of scales, and hemipenial morphology. From B. insularis and B. alcatraz, both related species endemic to islands in southeastern Brazil, B. otavioi sp. nov. differs mainly in its body form and number of scales. The new species has the twist common mitochondrial haplotype for mainland populations of B. jararaca, which is also found in B. alcatraz. A mitochondrial genealogy (gene tree) shows the new species nested within the northern clade of B. jararaca. This genealogical pattern can be explained by a recent speciation event for B. otavioi sp. nov. The isolation of insular species of Bothrops from continental ancestor populations are probably related to the same vicariant process, the oscillations of sea level during the Pleistocene. The new species feeds on small hylid frogs, and attains sexual maturity at 388 mm snout-vent length (SVL; males) and 692 mm SVL (females). Bothrops facial sp. nov. is endemic to Vitoria Island, and should be listed as critically endangered because it is known from only a single area (an island), its geographic range covers less than 100 km(2), and there is a projected continuing decline in the quality of its habitat because of increasing human settlement.

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Human Parvovirus B19 (B19V) is a recognized cause of life-threatening conditions among patients with hemoglobinopathies. This study investigates B19V infection in patients with sickle cell disease and beta-thalassemia using different experimental approaches. A total of 183 individuals (144 with sickle cell disease and 39 with beta-thalassemia major) and 100 healthy blood donors were examined for B19V using anti-B19V IgG enzyme immunoassay, quantitative PCR, DNA sequencing, and phylogenetic analysis. Viremia was documented in 18.6% of patients and 1% of donors, and was generally characterized by low viral load (VL); however, acute infections were also observed. Anti-B19V IgG was detected in 65.9% of patients with sickle cell disease and in 60% of donors, whereas the patients with thalassemia exhibited relatively low seroreactivity. The seroprevalence varied among the different age groups. In patients, it progressively increased with age, whereas in donors it reached a plateau. Based on partial NS1 fragments, all isolates detected were classified as subgenotype 1A with a tendency to elicit genetically complex infections. Interestingly, quasispecies occurred in the plasma of not only patients but also donors with even higher heterogeneity. The partial NS1 sequence examined did not exhibit positive selection. Quantitation of B19V with a conservative probe is a technically and practically useful approach. The extensive spread of B19V subgenotype 1A in patients and donors and its recent introduction into the countryside of the Sao Paulo State, Brazil were demonstrated; however, it is difficult to establish a relationship between viral sequences and the clinical outcomes of the infection. J. Med. Virol. 84:16521665, 2012. (c) 2012 Wiley Periodicals, Inc.

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During the last century, great improvements have been made in rectal cancer management regarding preoperative staging, pathologic assessment, surgical technique, and multimodal therapies. Surgically, there was a move from a strategy characterized by simple perineal excision to complex procedures performed by means of a laparoscopic approach, and more recently with the aid of robotic systems. Perhaps the most important advance is that rectal cancer is no longer a fatal disease as it was at the beginning of the 20th century. This achievement is definitely due in part to Ernest Mile's contribution regarding lymphatic spread of tumor cells, which helped clarify the natural history of the disease and the proper treatment alternatives. He advocated a combined approach with the rationale to clear "the zone of upward spread." The aim of the present paper is to present a brief review concerning the evolution of rectal cancer surgery, focusing attention on Miles' abdominoperineal excision of the rectum (APR) and its controversies and refinements over time. Although APR has currently been restricted to a small proportion of patients with low rectal cancer, recent propositions to excise the rectum performing a wider perineal and a proper pelvic floor resection have renewed interest on this procedure, confirming that Ernest Miles' original ideas still influence rectal cancer management after more than 100 years.