996 resultados para larva-development
Resumo:
Patients with primary head and neck cancers have a higher risk of developing esophageal cancer. The aim of this study was to investigate esophageal cancer prevalence, its risk factors (ethanol and tobacco consumption) and dietary habits in patients with head and neck cancer. Three hundred and twenty-six adults with primary head and neck cancer were followed by a retrospective observational study in a general university hospital in Sao Paulo, Brazil. Flexible videoendoscopy with lugol chromoscopy was the method used to investigate esophageal cancer prevalence. All subjects were interviewed face-to-face, revealing detailed information about their tobacco and alcohol use, as well as their dietary habits. Thirty-six patients with esophageal cancer were diagnosed and the overall prevalence rate was 11.04%. Patients who developed second esophageal tumors had the following characteristics: earlier age of initial ethanol consumption (P < 0.05), longer duration period of ethanol consumption (P < 0.05) and higher weekly consumption rate (P < 0.05). There was an increased risk of esophageal carcinoma in those patients who both smoked and drank (P < 0.05). There was no association between carcinoma of the esophagus and dietary habits in patients who developed esophageal neoplasms, compared with those who did not. Prevalence rate of esophageal neoplasms was 11.04% in patients with head and neck carcinoma, whose ethanol consumption was associated with esophageal cancer. There was an increased risk between ethanol and tobacco consumption and esophageal carcinoma development. On the other hand, there was no association regarding dietary habits between patients who developed esophageal cancer and those who did not.
Resumo:
An increased risk of early pregnancy loss in women briefly exposed to high levels of ambient particulate matter during the preconceptional period was recently observed. The effects of this exposure on early embryo development are unknown. This study was designed to assess the dose-response and biological effects of diesel exhaust particles (DEP) on in vitro embryo development using the in vitro fertilization (IVF) mouse model. Zygotes obtained from superovulated mice after IVF were randomly cultured in different DEP concentrations (0, 0.2, 2, and 20 mu g/cm(2)) for 5 days and observed for their capacity to attach and develop on a fibronectin matrix until day 8. Main outcome measures included blastocyst rates 96 and 120 h after insemination, hatching discriminatory score, total cell count, proportion of cell allocation to inner cell mass (ICM) and trophectoderm (TE), ICM morphology, attachment rate and outgrowth area, apoptosis and necrosis rates, and Oct-4 and Cdx-2 expression. Multivariate analysis showed a negative dose-dependent effect on early embryo development and hatching process, blastocyst cell allocation, and ICM morphology. Although blastocyst attachment and outgrowth were not affected by DEP, a significant impairment of ICM integrity was observed in day 8 blastocysts. Cell death through apoptosis was significantly higher after DEP exposure. Oct-4 expression and the Oct-4/Cdx-2 ratio were significantly decreased in day 5 blastocysts irrespective of DEP concentration. Results suggest that DEP appear to play an important role in disrupting cell lineage segregation and ICM morphological integrity even at lower concentrations, compromising future growth and viability of the blastocyst.
Resumo:
Several differences have been described between neonatal and adult immune responses. The predisposition in early life to Th2-type response or tolerance makes it a susceptible period for infections and allergic sensitization. The aim of this work was to evaluate the effects of CpG-containing oligodeoxynucleotides on neonatal and adult immunization with ovalbumin and Blomia tropicalis extract and compare the CpG effects on B and T cells of neonatal and adult mice. Mice that received CpG showed reduced immunoglobulin E (IgE) antibody production in both neonatal and adult periods, in parallel to increased IgG2a antibody levels. We observed that spleen cells of mice that received CpG in early life produced increased amounts of interferon-gamma upon anti-CD3 stimulation. Negative regulation of IgE response was more pronounced in adult than neonate mice; further, CpG decreased anaphylactic antiovalbumin IgG1 only in adults. Also, an upregulation of toll-like receptor 9 expression was detected in adult B cells, but not in neonatal, upon CpG stimuli. Neonatal B cells showed enhanced interleukin (IL)-10 expression and decreased IL-6 levels than adult B cells in response to CpG. When we analyzed in vitro activation of CD4+ T cells, an increased expression of B7 molecules on T cells in neonates was suppressed by CpG. Altogether, we verified qualitative and quantitative evidences regarding CpG effect on neonatal and adult allergens immunizations, which points to the importance of understanding neonatal immune system to establish immunomodulatory strategies for prevention of allergic diseases.
Resumo:
Objective: To evaluate effects of pre- and/or postnatal exposure to ambient fine particulate matter on fertilization, embryo development, and cell lineage segregation in preimplantation blastocysts using the IVF mouse model. Design: Animal model. Setting: Academic institution. Animal(S): Six-week-old, superovulated mice. Intervention(s): Pre- and postnatal exposure to filtered air (FA-FA), filtered-ambient air (FA-AA), or ambient air (AA-AA) in exposure chambers 24 hours a day for 9 weeks. Main Outcome Measure(S): Gestation length, litter size, sex ratio, ovarian response to superovulation, fertilization rate, embryo development, blastocyst and hatching rates, total cell count, and proportion of cell allocation to inner-cell mass (ICM) and trophectoderm (TE). Result(S): Gestation length, litter size and birth weight, live-birth index, and sex ratio were similar among exposure groups. Ovarian response was not affected by the exposure protocol. A multivariate effect for pre- and/or postnatal exposure to ambient fine particulate matter on IVF, embryo development, and blastocyst differential staining was found. Cell counts in ICM and ICM/TE ratios in blastocysts produced in the FA-FA protocol were significantly higher than in blastocysts produced in the FA-AA and AA-AA protocols. No difference in total cell count was observed among groups. Conclusion(S): Our study suggests that exposure to ambient fine particulate matter may negatively affect female reproductive health by disrupting the lineage specification at the blastocyst stage without interfering in early development of the mouse embryo. (Fertil Steril (R) 2009;92:1725-35. (C) 2009 by American Society for Reproductive Medicine.)
Resumo:
Context: Although numerous studies have examined the role of latent variables in the structure of comorbidity among mental disorders, none has examined their role in the development of comorbidity. Objective: To study the role of latent variables in the development of comorbidity among 18 lifetime DSM-IV disorders in the World Health Organization World Mental Health Surveys. Design: Nationally or regionally representative community surveys. Setting: Fourteen countries. Participants: A total of 21 229 survey respondents. Main Outcome Measures: First onset of 18 lifetime DSM-IV anxiety, mood, behavior, and substance disorders assessed retrospectively in the World Health Organization Composite International Diagnostic Interview. Results: Separate internalizing (anxiety and mood disorders) and externalizing (behavior and substance disorders) factors were found in exploratory factor analysis of lifetime disorders. Consistently significant positive time-lagged associations were found in survival analyses for virtually all temporally primary lifetime disorders predicting subsequent onset of other disorders. Within-domain (ie, internalizing or externalizing) associations were generally stronger than between-domain associations. Most time-lagged associations were explained by a model that assumed the existence of mediating latent internalizing and externalizing variables. Specific phobia and obsessive-compulsive disorder (internalizing) and hyperactivity and oppositional defiant disorders (externalizing) were the most important predictors. A small number of residual associations remained significant after controlling the latent variables. Conclusions: The good fit of the latent variable model suggests that common causal pathways account for most of the comorbidity among the disorders considered herein. These common pathways should be the focus of future research on the development of comorbidity, although several important pairwise associations that cannot be accounted for by latent variables also exist that warrant further focused study.
Schumpeter and the Dynamics of Capitalism: Industrial Development, Economic Evolution and Innovation