884 resultados para Embryonic mortality
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Background: There is little information regarding the impact of diet on disease incidence and mortality in Switzerland. We assessed ecologic correlations between food availability and disease.Methods: In this ecologic study for the period 1970-2009, food availability was measured using the food balance sheets of the Food and Agriculture Organization of the United Nations. Standardized mortality rates (SMRs) were obtained from the Swiss Federal Office of Statistics. Cancer incidence data were obtained from the World Health Organization Health For All database and the Vaud Cancer Registry. Associations between food availability and mortality/incidence were assessed at lags 0, 5, 10, and 15 years by multivariate regression adjusted for total caloric intake.Results: Alcoholic beverages and fruit availability were positively associated, and fish availability was inversely associated, with SMRs for cardiovascular diseases. Animal products, meat, and animal fats were positively associated with the SMR for ischemic heart disease only. For cancer, the results of analysis using SMRs and incidence rates were contradictory. Alcoholic beverages and fruits were positively associated with SMRs for all cancer but inversely associated with all-cancer incidence rates. Similar findings were obtained for all other foods except vegetables, which were weakly inversely associated with SMRs and incidence rates. Use of a 15-year lag reversed the associations with animal and vegetal products, weakened the association with alcohol and fruits, and strengthened the association with fish.Conclusions: Ecologic associations between food availability and disease vary considerably on the basis of whether mortality or incidence rates are used in the analysis. Great care is thus necessary when interpreting our results.
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OBJECTIVE: To update trends in mortality from coronary heart diseases (CHD) and cerebrovascular diseases (CVD) over the period 1981-2004 in Europe, the USA, Latin America, Japan and other selected areas of the world. METHODS: Age-standardized mortality rates were derived from the World Health Organization database. Joinpoint analysis was used to identify significant changes in trends. RESULTS: In the European Union (27 countries), CHD mortality in men declined from 139/100,000 in 1985-1989 to 93/100,000 in 2000-2004 (-33%). In women, the fall was from 61/100,000 to 44/100,000 (-27%). In this area, a decline by over 30% was also registered in CVD mortality for both sexes. In the Russian Federation and other countries of the former Soviet Union, CHD rates in 2000-2004 were exceedingly high, around 380/100,000 men and 170/100,000 women in Russia, 430 for men and 240 for women in Ukraine, 420 and 200 in Belarus. For CVD, a similar situation was registered, with mortality rates of 226/100,000 for men and 159/100,000 for women in 2004 in the Russian Federation, and more than 24% increase since the late 1980s for men and 15% for women. CHD and CVD mortality continued to decline in most Latin American countries, Australia and other areas considered, including Asia (even if with marked differences). CONCLUSION: Although mortality from CHD and CVD continues to decline in several areas of the world including most countries of Europe and of the America providing data and Australia, unfavourable trends were still observed in the Russian Federation and other countries of the former Soviet Union, whose recent rates remain exceedingly high.
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This paper measures the degree of inequality in child mortality rates across districts in India, using data from the 1981, 1991 and 2001 Indian population censuses. The results show that child mortality is more concentrated in less developed districts in all three census years. Further, between 1981 and 2001, the inequality in child mortality seems to have increased to the advantage of the more developed districts (i.e., there was an increasing concentration of child mortality in less developed districts). However, the inequality in female child mortality rates seems to have declined between 1991 and 2001, even as it increased – albeit at a slower rate than before – for male child mortality rates. In the decomposition analysis, it is found that while a more equitable distribution of medical facilities and safe drinking water across districts did contribute towards reducing inequality in child mortality between 1981 and 1991, different levels of structural change among districts were responsible for a very large part of the inequality in child mortality to the advantage of the more developed districts in all three census years. Other variables which played important roles in increasing inequality included a measure of infrastructure development, female literacy, and a social group status variable. The paper concludes with some brief comments on the policy implications of the findings.
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Although therapeutic advancements have made Hodgkin's lymphoma (HL) a largely curable disease, trends in HL mortality have been variable across countries. To provide updated information on HL mortality in the Americas, overall and 20-44 years age-standardized (world population) mortality rates from HL were derived for the 12 Latin American countries providing valid data to the World Health Organization database and with more than two million of inhabitants. For comparative purpose, data for the United States and Canada were also presented. Trends in mortality over the 1997 to 2008 period are based on joinpoint regression analysis. Declines in HL mortality were registered in all Latin American countries except in Venezuela. In most recent years, HL mortality had fallen to about 0.3/100,000 men and 0.2/100,000 women in Argentina, Brazil, Chile, Colombia, Ecuador and Guatemala, that is, to values similar to North America. Despite some declines, rates remained high in Cuba (1/100,000 men and 0.7/100,000 women), Costa Rica and Mexico as well as in Venezuela (between 0.5 and 0.6/100,000 men and between 0.3 and 0.5/100,000 women). In young adults, trends were more favorable in all Latin American countries except Cuba, whose rates remained exceedingly high (0.8/100,000 men and 0.6/100,000 women). Thus, appreciable declines in HL mortality were observed in most Latin America over the last decade, and several major countries reached values comparable to North America. Substantial excess mortality was still observed in Cuba, Costa Rica, Mexico and Venezuela, calling for urgent interventions to improve HL management in these countries.
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Social deprivation can have negative effects on the lives of social animals, including humans, yet little is known about the mechanisms by which social withdrawal affects animal health. Here we show that in the carpenter ant Camponotus fellah, socially isolated workers have a greatly reduced life span relative to ants kept in groups of ten individuals. By using a new tracking system, we found that social isolation resulted in important behavioral changes and greatly increased locomotor activity. The higher activity of single ants and their increased propensity to leave the nest to move along the walls suggested that the increased mortality of isolated ants might stem from an imbalance of energy income and expenditure. This view was supported by the finding that while isolated ants ingested the same amount of food as grouped ants, they retained food in the crop, hence preventing its use as an energy source. Moreover, the difference in life span between single and grouped individuals vanished when ants were not fed. This study thus underlines the role of social interactions as key regulators of energy balance, which ultimately affects aging and health in a highly social organism.
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Several groups have demonstrated the existence of self-renewing stem cells in embryonic and adult mouse brain. In vitro, these cells proliferate in response to epidermal growth factor, forming clusters of nestin-positive cells that may be dissociated and subcultured repetitively. Here we show that, in stem cell clusters derived from rat embryonic striatum, cell proliferation decreased with increasing number of passages and in response to elevated concentrations of potassium (30 mM KCl). In monolayer culture, the appearance of microtubule-associated protein type-5-immunoreactive (MAP-5(+)) cells (presumptive neurons) in response to basic fibroblast growth factor (bFGF) was reduced at low cell density and with increasing number of passages. In the presence of bFGF, elevated potassium caused a more differentiated neuronal phenotype, characterized by an increased proportion of MAP-5(+) cells, extensive neuritic branching, and higher specific activity of glutamic acid decarboxylase. Dissociated stem cells were able to invade cultured brain cell aggregates containing different proportions of neurons and glial cells, whereas they required the presence of a considerable proportion of glial cells in the host cultures to become neurofilament H-positive. The latter observation supports the view that astrocyte-derived factors influence early differentiation of the neuronal cell lineage.
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Texte intégral: http://www.springerlink.com/content/3q68180337551r47/fulltext.pdf
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The ability of the developing myocardium to tolerate oxidative stress during early gestation is an important issue with regard to possible detrimental consequences for the fetus. In the embryonic heart, antioxidant defences are low, whereas glycolytic flux is high. The pro- and antioxidant mechanisms and their dependency on glucose metabolism remain to be explored. Isolated hearts of 4-day-old chick embryos were exposed to normoxia (30 min), anoxia (30 min), and hyperoxic reoxygenation (60 min). The time course of ROS production in the whole heart and in the atria, ventricle, and outflow tract was established using lucigenin-enhanced chemiluminescence. Cardiac rhythm, conduction, and arrhythmias were determined. The activity of superoxide dismutase, catalase, gutathione reductase, and glutathione peroxidase as well as the content of reduced and oxidized glutathione were measured. The relative contribution of the ROS-generating systems was assessed by inhibition of mitochondrial complexes I and III (rotenone and myxothiazol), NADPH oxidases (diphenylene iodonium and apocynine), and nitric oxide synthases (N-monomethyl-l-arginine and N-iminoethyl-l-ornithine). The effects of glycolysis inhibition (iodoacetate), glucose deprivation, glycogen depletion, and lactate accumulation were also investigated. In untreated hearts, ROS production peaked at 10.8 ± 3.3, 9 ± 0.8, and 4.8 ± 0.4 min (means ± SD; n = 4) of reoxygenation in the atria, ventricle, and outflow tract, respectively, and was associated with arrhythmias. Functional recovery was complete after 30-40 min. At reoxygenation, 1) the respiratory chain and NADPH oxidases were the main sources of ROS in the atria and outflow tract, respectively; 2) glucose deprivation decreased, whereas glycogen depletion increased, oxidative stress; 3) lactate worsened oxidant stress via NADPH oxidase activation; 4) glycolysis blockade enhanced ROS production; 5) no nitrosative stress was detectable; and 6) the glutathione redox cycle appeared to be a major antioxidant system. Thus, the glycolytic pathway plays a predominant role in reoxygenation-induced oxidative stress during early cardiogenesis. The relative contribution of mitochondria and extramitochondrial systems to ROS generation varies from one region to another and throughout reoxygenation.
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Hexaflumuron, an insect growth regulator (IGR), was found to greatly affect the development of immatures and emergence of adults of three species of vector mosquitoes, Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi, when larvae were subjected to short time exposure of < or = 1h. This IGR could completely prevent adult emergence even at a minimum exposure time of 10 min at 0.001, 0.01 and 0.1 mg/l. On treatment, larval and pupal mortality as well as varying degrees of morphogenetic abnormalities were induced in immatures and adults of the three species. Four weeks of control achieved in a slow moving sullage canal breeding Culex quinquefasciatus indicates that this IGR can be of use in such breeding habitats.
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A cohort of 100 eggs of Triatoma mazzottii Usinger was studied to obtain information on its life cycle. Egg incubation took 24 days; mean duration of 1st, 2nd, 3rd, 4th, and 5th instar nymphs was 27, 36, 39, 46 and 64 days respectively; mean time from egg to adult was 236 days. The total duration of the nymphal stages was 212 days. The total nymph mortality in cohort was 16.3% and the embryonic egg mortality was 14.0%. The grater mortality occured in the 2nd instar. The average number of eggs/female/week was 9.8 during 15 weeks of observation. Of the total eggs laid (2,514), only 58.7% hatched. The total of insects that achieved the adult stage (72), 38 were females (52.8%), and 34 were males (47.2%). The influence of age and feeding on the first mating of T. mazzottii were also studied. It was found that the first mating depended on the male's age and it was on the average 30 days after the last imaginal molt. The female could be mating since 2nd days after the imaginal life. The nutritional status did not play an important role in the capacity of the insect for the first mating.
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L-Type Ca(2+) and K(ATP) Channels in Pacing-Induced Cardioprotection. AIMS: The L-type Ca(2+) channel, the sarcolemmal (sarcK(ATP)), and mitochondrial K(ATP) (mitoK(ATP)) channels are involved in myocardial preconditioning. We aimed at determining to what extent these channels can also participate in pacing-induced cardioprotection. METHODS: Hearts of 4-day-old chick embryos were paced in ovo during 12 hour using asynchronous intermittent ventricular stimulation at 110% of the intrinsic rate. Sham operated and paced hearts were then submitted in vitro to anoxia (30 minutes) and reoxygenation (60 minutes). These hearts were exposed to L-type Ca(2+) channel agonist Bay-K-8644 (BAY-K) or blocker verapamil, nonselective K(ATP) channel antagonist glibenclamide (GLIB), mitoK(ATP) channel agonist diazoxide (DIAZO), or antagonist 5-hydroxydecanoate. Electrocardiogram, electromechanical delay (EMD) reflecting excitation-contraction (E-C) coupling, and contractility were determined. RESULTS: Under normoxia, heart rate, QT duration, conduction, EMD, and ventricular shortening were similar in sham and paced hearts. During reoxygenation, arrhythmias ceased earlier and ventricular EMD recovered faster in paced hearts than in sham hearts. In sham hearts, BAY-K (but not verapamil), DIAZO (but not 5-hydroxydecanoate) or GLIB accelerated recovery of ventricular EMD, reproducing the pacing-induced protection. By contrast, none of these agents further ameliorated recovery of the paced hearts. CONCLUSION: The protective effect of chronic asynchronous pacing at near physiological rate on ventricular E-C coupling appears to be associated with subtle activation of L-type Ca(2+) channel, inhibition of sarcK(ATP) channel, and/or opening of mitoK(ATP) channel.
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Over the last decade, mortality from oral and pharyngeal cancer has been declining in most European countries, but it had been increasing substantially in Hungary, Slovakia and a few other countries of central Europe, reaching rates comparable to those of lung cancer in several western European countries in males. To update trends in oral cancer mortality and further analyse the recent epidemic in central Europe, official death certifications for oral and pharyngeal cancer for 37 European countries were derived over the period 1970-2007, and an age-period-cohort model was fitted for selected countries. Male oral cancer mortality continued to decline in most European countries, including the Russian Federation, and, more importantly, it also started to decline in some of the countries with the highest male rates, i.e. Hungary and Slovakia; persisting rises were, however, observed in Belarus, Bulgaria and Romania. Oral cancer mortality rates for women were lower than in men and showed no appreciable trend over recent periods in the EU overall. Estimates from the age-period-cohort analysis for most selected countries showed a fall in effects for the cohorts born after the 1950s. For the period effect displayed a rise for the earlier periods, an inversion in the 1990s and a continuous fall up to the last studied period. Only some former non-market economy countries, like Romania, Ukraine and Lithuania, had rising cohort effect trends up to most recent generations. The major finding of this updated analysis of oral cancer mortality is the leveling of the epidemic for men in most European countries, including Hungary and other central European countries, where mortality from this cancer was exceedingly high. These trends essentially reflect the changes in alcohol and tobacco consumption in various populations.
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Glutaryl-CoA dehydrogenase (GCDH, EC 1.3.99.7) deficiency, known as glutaric acidemia type I, is one of the more common organic acidurias. To investigate the role of this pathway in different organs we studied the tissue-specific expression pattern of rat Gcdh. The open reading frame cDNA of the rat Gcdh gene was cloned from rat brain mRNA by RT-PCR, allowing the synthesis of digoxigenin-labeled in situ hybridization (ISH) riboprobes. Gcdh mRNA expression was analyzed by ISH on cryosections of adult rat brain, kidney, liver, spleen and heart muscle, as well as on E15 and E18 rat embryos. Gcdh was found expressed in the whole rat brain, almost exclusively in neurons. Gcdh was absent from astrocytes but expressed in rare oligodendrocytes. Strong Gcdh expression was found in liver and spleen, where expression appears predominant to lymphatic nodules. In kidney, the highest Gcdh expression is found in the juxtamedullar cortex (but not in glomerula), and at lower levels in medulla. Heart muscle was negative. During embryonic development, Gcdh was found well expressed in liver, intestinal mucosa and skin, as well as at lower levels in CNS. Further studies are ongoing to provide evidence on the presence of the entire pathway in CNS in order to understand the mechanisms leading to neurotoxicity in glutaric aciduria. The high expression of Gcdh in kidney may explain why certain patients with residual enzyme activity are low excretors at the urine metabolite level.
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The role of public health has been a central topic on the classical debate about the historical mortality decline in Europe. One of these health initiatives were the Milk Depots. Spain set up those centres from the late 19th century until the beginning of the Civil War. The goal of this paper is to evaluate the effect of this health intervention on the infant mortality decline during this period. This study works out three kinds of sources: Statistical Yearbooks, Official documents and local records produced by the same Milk Depot. It analyses data available for all the country and one local case such as the Barcelona’s Milk Depot (1904-1935). The main methodological issue deals with the measurement of the effect of the Milk Depot activities on the pattern of changes of infant mortality. Results suggest that Milk Depots have a positive but quite moderate effect on the improving of overall levels of child survival.