968 resultados para Human beings, Origin of.
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To determine whether human X-linked neonatal diabetes mellitus, enteropathy and endocrinopathy syndrome (IPEX; MIM 304930) is the genetic equivalent of the scurfy (sf) mouse, we sequenced the human ortholog (FOXP3) of the gene mutated in scurfy mice (Foxp3), in IPEX patients. We found four non-polymorphic mutations. Each mutation affects the forkhead/winged-helix domain of the scurfin protein, indicating that the mutations may disrupt critical DNA interactions.
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Conservation of biodiversity can generate considerable indirect economic value and this is being increasingly recognized in China. For a forest ecosystem type of a nature reserve, the most important of its values are its ecological functions which provide human beings and other living things with beneficial environmental services. These services include water conservancy, soil protection, CO2 fixation and O-2 release, nutrient cycling, pollutant decomposition, and disease and pest control. Based on a case study in Changbaishan Mountain Biosphere Reserve in Northeast China, this paper provides a monetary valuation of these services by using opportunity cost and alternative cost methods. Using such an approach, this reserve is valued at 510.11 million yuan (USD 61.68 mill.) per year, 10 times higher than the opportunity cost (51.78 mill. yuan/ha.a) for regular timber production. While China has heeded United Nations Environmental Program (UNEP)'s call for economic evaluation of ecological functions, the assessment techniques used need to be improved in China and in the West for reasons mentioned.
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It has been established that modern humans were living in the Levant and Africa ca. 100 ka ago. Hitherto, this has contrasted with the situation in China where no unequivocal specimens of this species have been securely dated to more than 30 ka. Here we present the results of stratigraphic studies and U-series dating of the Tongtianyan Cave, the discovery site of the Liujiang hominid, which represents one of the few well-preserved fossils of modern Homo sapiens in China. The human fossils are inferred to come from either a refilling breccia or a primarily deposited gravel-bearing sandy clay layer. In the former case, which is better supported, the fossils would date to at least similar to 68 ka, but more likely to similar to 111-139 ka. Alternatively, they would be older than, similar to 153 ka. Both scenarios would make the Liujiang hominid one of the earliest modem humans in East Asia, possibly contemporaneous with the earliest known representatives from the Levant and Africa. Parallel studies on other Chinese localities have provided supporting evidence for the redating of Liujiang, which may have important implications for, the origin of modem humans. (C) 2002 Elsevier Science Ltd. All rights reserved.
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Background The ability of T cells, acting independently of antibodies, to control malaria parasite growth in people has not been defined. If such cell-mediated immunity was shown to be effective, an additional vaccine strategy could be pursued. Our aim was to ascertain whether or not development of cell-mediated immunity to Plasmodium falciparum blood-stage infection could be induced in human beings by exposure to malaria parasites in very low density. Methods We enrolled five volunteers from the staff at our research institute who had never had malaria. We used a cryopreserved inoculum of red cells infected with P falciparum strain 3D7 to give them repeated subclinical infections of malaria that we then cured early with drugs, to induce cell-mediated immune responses. We tested for development of immunity by measurement of parasite concentrations in the blood of volunteers by PCR of the multicopy gene STEVOR and by following up the volunteers clinically, and by measuring antibody and cellular immune responses to the parasite. Findings After challenge and a extended period without drug cure, volunteers were protected against malaria as indicated by absence of parasites or parasite DNA in the blood, and absence of clinical symptoms. Immunity was characterised by absence of detectable antibodies that bind the parasite or infected red cells, but by the presence of a proliferative T-cell response, involving CD4+ and CD8+ T cells, a cytokine response, consisting of interferon gamma but not interleukin 4 or interleukin 10, induction of high concentrations of nitric oxide synthase activity in peripheral blood mononuclear cells, and a drop in the number of peripheral natural killer T cells. Interpretation People can be protected against the erythrocytic stage of malaria by a strong cell-mediated immune response, in the absence of detectable parasite-specific antibodies, suggesting an additional strategy for development of a malaria vaccine.
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The N-methyl-D-aspartate (NMDA)-selective subtype of ionotropic glutamate receptor is of importance in neuronal differentiation and synapse consolidation, activity-dependent forms of synaptic plasticity, and excitatory amino acid-mediated neuronal toxicity [Neurosci. Res. Program, Bull. 19 (1981) 1; Lab. Invest. 68 (1993) 372]. NMDA receptors exist in vivo as tetrameric or pentameric complexes comprising proteins from two families of homologous subunits, designated NR1 and NR2(A-D) [Biochem. Biophys. Res. Commun. 185 (1992) 826]. The gene coding for the human NR1 subunit (hNR1) is composed of 21 exons, three of which (4, 20 and 21) can be differentially spliced to generate a total of eight distinct subunit variants. We detail here a competitive RT-PCR (cRT-PCR) protocol to quantify endogenous levels of hNR1 splice variants in autopsied human brain. Quantitation of each hNR1 splice variant is performed using standard curve methodology in which a known amount of synthetic ribonucleic acid competitor (internal standard) is co-amplified against total RNA. This method can be used for the quantitation of hNR1 mRNA levels in response to acute or chronic disease states, in particular in the glutamatergic-associated neuronal loss observed in Alzheimer's disease [J. Neurochem. 78 (2001) 175]. Furthermore, alterations in hNR1 mRNA expression may be reflected at the translational level, resulting in functional changes in the NMDA receptor. (C) 2003 Elsevier Science B.V. All rights reserved.
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Those over sixty years of age accounted for 6.6% of the total population of Brazil in 1985, in the Federal Republic of Germany this proportion was 20.3% in 1984. As early as 1950 it had been 14.5%. This proportion will not even be reached in Brazil in the year 2000 when persons aged sixty years and older are only projected to make up 8.8% of the total population. Similarly, in 1982/84 life expectancy at birth in the Federal Republic was 70.8 years for men and 77.5 for women; in Brazil the figures for 1980/85 were, by contrast, "only" 61.0 and 66.0. Against this background it is easy to understand why the discussion concerning an ageing society with its many related medical, economic, individual and social problems has been so slow in coming into its own in Brazil. As important as a more intensive consideration of these aspects may be in Brazil at present, they are, nevertheless, only one side of the story. For a European historical demographer with a long-term perspective of three of four hundred years, the other side of the story is just as important. The life expectancy which is almost ten years lower in Brazil is not a result of the fact that no one in Brazil lives to old age. In 1981 people sixty-five years and older accounted for 34.4% of all deaths! At the same time infants accounted for only 22.1% of total mortality. They are responsible, along with the "premature" deaths among youths and adults, for the low, "average" life expectancy figure. In Europe, by contrast, these "premature" deaths no longer play much of a role. In 1982/84 more than half of the women (52.8%) in the Federal Republic of Germany lived to see their eightieth birthdays and almost half of the men (47.3%) lived to see their seventy-fifth. Our biological existence is guaranteed to an extent today that would have been unthinkable a few generations ago. Then, the classic troika of "plague, hunger and war" threatened our forefathers all the time and everywhere. The radical transition from the formerly uncertain to a present-day certain lifetime, which is the result of the repression of "plague, hunger and war", led to unexpected consequences for our living together. Our forefathers were forced to live in closely knit Gemeinschaften in the interest of physical survival and to subordinate their egoistic goals to a common value, but now these pressures have, for the most part, fallen away. Correspondingly, this much more certain EGO has taken center stage. An ever greater number of us chooses to live life as single beings: the number of marriages is lower every year; the number of divorces is on the increase; in Berlin (West) more than half (sic! 52.3%) of all households are already composed on only one person. For the last dozen years the annual number of births in the Federal Republic has been insufficient to ensure population replacement. Not a population explosion but rather the opposite, a population implosion, is our problem. Human beings do not appear to be "social animals", as was axiomatically assumed for so long. They were only forced to behave as such for as long as "plague, hunger and war" forced them to do so. When these life endangering conditions no longer exist and life becomes certain even without their being integrated into a Gemeinschaft then humans suddenly show themselves more and more to be independent single beings. It is not the percentage of the population that is over sixty or sixty-five that is decisive in this context but rather how certain adults perceive their biological lives to be, since they are the ones who organize their lives, who build communities or who are ever more often willing only to enter into means-to-an-end personal unions without lasting or close ties and mutual responsibilities. There are many signs which seem to point to a development in this direction in Brazil as well. More and more adults in Brazil are caught up in the deep-seated transition from an uncertain to a certain lifetime. A third of them die after having reached their sixty-fifth birthday. It therefore seems to me to be high time that one began to give more consideration to the other side of the story in Brazil as well. And who is more suited intensively to consider the long-term perspectives than those engaged in the public health sector in whose competence, after all, such aspects, as "life certainty", "life expectancy" and "age at death" belong?
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Dissertação de Mestrado, Património, Museologia e Desenvolvimento, 2 de Outubro de 2015, Universidade dos Açores.
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Dissertação de Mestrado, Geologia do Ambiente e Sociedade, 15 de Fevereiro de 2016, Universidade dos Açores.
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Conferência: 9th International Symposium on Occupational Safety and Hygiene (SHO) Guimaraes, Portugal - FEB 14-15, 2013
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Cell mediated immune response was studied in patients with recent and chronic Schistosoma mansoni infection. Precultured peripheral mononuclear cells showed significantly higher responses to S. mansoni adult worm antigen (SAWA) when compared to fresh cell preparations. The addition of each patient serum to the precultured cells reactions to SAWA or recall antigens demonstrated a strong inhibitory serum action, which was also noted on allogeneic cells derived from healthy subjects. The CD4 subset was the main responding cell to SAWA being this reactivity highly suppressed by the presence of the monocyte macrophage accessory cells. We stressed the simultaneous inhibitory action of humoral and cellular factors on the specific cell response to S. mansoni.
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A Dot enzyme-linked immunosorbent assay (Dot-ELISA) was standardized and evaluated for the serodiagnosis of human toxoplasmosis. Out of 538 serum samples tested by the immunofluorescence test for toxoplasmosis (IFAT-IgG) as reference test, 183 (34%) were positive at cut off 1:16 and 192 (36%) were positive for Dot-ELISA-IgG at cut-off 1:256. For Dot-ELISA, co-positivity was 0.94, co-negativity 0.94 and concordance 0.88 in relation to IFAT-IgG. These results suggest the usefulness of Dot-ELISA (cut-off titer of 1:256) for the serodiagnosis of human toxoplasmosis. The main advantage of this technique is simplicity, positive test can be visually identified (colored precipitate). It does not require a special equipment and it can be used as a qualitative test to screen large numbers of samples or as a quantitative assay to determine end-point titration of individual sera.
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The mechanisms used by Paracoccidioides brasiliensis to survive into phagocytic cells are not clear. Cellular iron metabolism is of critical importance to the growth of several intracellular pathogens whose capacity to multiply in mononuclear phagocytes is dependent on the availability of intracellular iron. Thus, the objective of this paper was to investigate the role of intracellular iron in regulating the capacity of P. brasiliensis yeast cells to survive within human monocytes. Treatment of monocytes with deferoxamine, an iron chelator, suppressed the survival of yeasts in a concentration-dependent manner. The effect of deferoxamine was reversed by iron-saturated transferrin (holotransferrin) but not by nonsaturated transferrin (apotransferrin). These results strongly suggest that P. brasiliensis survival in human monocytes is iron dependent.
Protective and risk factors for toxocariasis in children from two different social classes of Brazil
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The aim of this study was to analyze the prevalence of Toxocara spp. antibodies in children from two different socioeconomic classes in the Presidente Prudente municipality, São Paulo State, Brazil, and the protective and risk factors associated with toxocariasis. One hundred and twenty-six middle-class (MC) and 126 disadvantaged children (DC) were included in this study. Anti-Toxocara ELISA test was performed in order to evaluate seroprevalence. A survey was applied to the children's guardians/parents in order to analyze the protective and risk factors. The overall prevalence was 11.1%, and of 9.5% (12/126) and 12.7% (16/126) for MC and DC subgroups, respectively. Toxocara seropositivity was inversely proportional to the family income. A high household income was considered a protective factor for toxocariasis in the total population and in both MC and DC subgroups. Being a girl was considered a protective factor for the total population and for both subgroups. Whilst being an owner of cat was a risk factor for children belonging to the total and for both MC and DC subgroups, having dog was considered as a risk factor for only the MC. Epidemiologic protective/factor risks can be distinct depending on the strata of the same population. Thus, it is relevant to evaluate these factors independently for different socioeconomic classes in order to design future investigations and programs for preventing the infection of human beings by Toxocara spp. and other geohelminths.
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work presented in the context of the European Master’s program in Computational Logic, as the partial requirement for obtaining Master of Science degree in Computational Logic
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In 1970, searching for the interspecies transmission of influenza viruses led to the first study on influenza viruses in domestic animals. Birds and mammals, including human beings, are their natural hosts; however, other animals may also play a role in the virus epidemiology. The objective was to investigate the incidence of influenza viruses in adult dogs raised in rural (9, 19.56%) and urban (37, 80.43%) areas in the state of São Paulo, Brazil. Dog serum samples were examined for antibodies to influenza viruses by the hemagglutination inhibition (HI) test using the corresponding antigens from the circulating viruses in Brazil. Dogs from rural areas presented antibodies to influenza A H3N2, and influenza A H7N7 and H3N8. In rural areas, dog sera displayed mean titers as 94.37, 227.88, 168.14, 189.62 HIU/25 µL for subtypes H1N1, H3N2, H7N7, H3N8, respectively. About 84% and 92% of dogs from urban areas exhibited antibodies to human influenza A H1N1 and H3N2, respectively, with statistical difference at p < 0.05 between the mean titers of antibodies to H1N1 and H3N2. About 92% and 100% were positive for H7N7 and H3N8, respectively. In dogs from urban areas, the mean titers of antibodies against influenza A H1N1, H3N2, H7N7 and H3N8, were 213.96, 179.42, 231.76, 231.35 HIU/25 µL respectively. The difference among them was not statistically significant at p > 0.05. In conclusion, these dogs were positive for both human and equine influenza viruses. The present study suggests the first evidence that influenza viruses circulate among dogs in Brazil.