Histopathological and immunohistochemical study of the hepatic lesions experimentally induced by Entamoeba dispar

The sequence of hepatic necrotic-inflammatory events produced by Entamoeba dispar are originally described in this work. For the first time the experimental lesions produced by E. dispar were described in details, as well as the distribution of the trophozoites detected by the immunohistochemistry. Animals experimentally infected with E. dispar presented necrosis, thrombosis and chronic granulomatous inflammation. Immunoreactive products derived from trofozoites were observed close or associated with trophozoites, epithelioid cells, leucocytes and hepatocytes. Few are the articles on the literature about virulence of E. dispar, which is approximately 9 times more frequent than to Entamoeba histolytica (E. histolytica). Variation in the virulence is therefore expected and signalizing the need of the continuity of studies with E. dispar strains from different places in the world. Taking into account that E. dispar is a closely related species to E. histolytica, these studies could determine new elements involved with E. histolytica pathogenesis, helping us to better understand the disease

Extending the Ehresmann-Schein-Nambooripad Theorem

We extend the `join-premorphisms' part of the Ehresmann-Schein-Nambooripad Theorem to the case of two-sided restriction semigroups and inductive categories, following on from a result of Lawson (1991) for the `morphisms' part. However, it is so-called `meet-premorphisms' which have proved useful in recent years in the study of partial actions. We therefore obtain an Ehresmann-Schein-Nambooripad-type theorem for meet-premorphisms in the case of two-sided restriction semigroups and inductive categories. As a corollary, we obtain such a theorem in the inverse case.Comment: 23 pages; final section on Szendrei expansions removed; further reordering of materia

Relationship between polymorphism of growth hormone and precocity traits in Nellore heifers

Avaliaram-se as relações entre o polimorfismo do gene do hormônio do crescimento (GH) e as características de precocidade, em novilhas da raça Nelore. Amostras de sangue periférico foram obtidas de 181 animais de três rebanhos distintos do estado da Bahia, nas quais foi realizada a extração de DNA e a amplificação por PCR, seguidas por digestão com enzima de restrição AluI. Os fragmentos resultantes da digestão enzimática foram analisados em gel de agarose 2% para determinação dos respectivos genótipos. A frequência do alelo Leu nas amostras analisadas foi estimada em 100%. Em decorrência da alta incidência de homozigose para o alelo Leu, sugere-se que o restriction fragment lenght polymorphism AluI do gene GH não possa ser considerado como marcador molecular para precocidade sexual em novilhas Nelore nesses rebanhos.The relationships between polymorphism of growth hormone gene (GH) and precocity traits in Nellore heifers were evaluated. A total of 181 animals from three different farms of Bahia state, Brazil, were blood sampled. The DNA of each animal was extracted, amplified by PCR, and digested by "AluI" restriction enzyme, and the resultant fragments were analyzed in 2% agarose gel for genotype identification. The frequency of Leu allele in the analyzed samples was estimated in 100%. Due to the high incidence of homozygose for the Leu allele, it is suggested that the restriction fragment lenght polymorphism AluI of GH gene can not be considered as a molecular marker for sexual precocity in Nellore heifers of those herds.Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Assessment of neural networks training strategies for histomorphometric analysis of synchrotron radiation medical images

Abstract Micro-computed tomography (μCT) obtained by synchrotron radiation (SR) enables magnified images with a high space resolution that might be used as a non-invasive and non-destructive technique for the quantitative analysis of medical images, in particular the histomorphometry (HMM) of bony mass. In the preprocessing of such images, conventional operations such as binarization and morphological filtering are used before calculating the stereological parameters related, for example, to the trabecular bone microarchitecture. However, there is no standardization of methods for HMM based on μCT images, especially the ones obtained with SR X-ray. Notwithstanding the several uses of artificial neural networks (ANNs) in medical imaging, their application to the HMM of SR-μCT medical images is still incipient, despite the potential of both techniques. The contribution of this paper is the assessment and comparison of well-known training algorithms as well as the proposal of training strategies (combinations of training algorithms, sub-image kernel and symmetry information) for feed-forward ANNs in the task of bone pixels recognition in SR-μCT medical images. For a quantitative comparison, the results of a cross validation and a statistical analysis of the results for 36 training strategies are presented. The ANNs demonstrated both very low mean square errors in the validation, and good quality segmentation of the image of interest for application to HMM in SR-μCT medical images

Contextual and individual determinants of non-utilization of dental services among Brazilian adults

OBJECTIVES: To examine the association of contextual and individual determinants with non-utilization of dental services among Brazilian adults. METHODS: Data were from adults aged 35-44 years (N = 7,265) from the 2010 Brazilian Oral Health Survey (SB Brasil Project). Non-utilization of dental services was assessed whether the individual has never had a dental visit over the whole life time. Independent variables were selected according to Andersen's behavioral model. Contextual variables included Human Development Index-longevity (HDI-Longevity) (predisposing demographic), HDI-Education and Gini index (predisposing social), integration of oral health teams into Primary Care (enabling health policy), and HDI-Income (enabling financing). Individual data were age and sex (predisposing demographic), ethnicity and schooling (predisposing social), family monthly income (predisposing enabling), perceived dental treatment (perceived need), and decayed teeth (evaluated need). The relationship of contextual and individual variables with non-utilization of dental services was assessed through multilevel logistic regression analysis to estimate odds ratios (ORs) and 95% confidence intervals (95% CI). RESULTS: The prevalence of non-utilization of dental services was 4.7 percent. Adults living in cities with high HDI-Income were less likely to never have a dental visit. The odds of non-utilization of dental services were lower for adults living in cities with high HDI-Longevity. Sex, skin color, dental treatment needs, poor socioeconomic characteristics, perceived dental treatment needs, and decayed teeth were also associated with non-utilization of dental services. CONCLUSIONS: The results suggest that contextual enabling and predisposing factors, individual sociodemographic, and needs-related characteristics influence non-utilization of dental services by Brazilian adults

Contribution of non-ionic interactions on bile salt sequestration by chitooligosaccharides: potential hypocholesterolemic activity

Chitooligosaccharides have been suggested as cholesterol reducing ingredients mostly due to their ability to sequestrate bile salts. The nature of the chitooligosaccharides-bile salts binding is usually linked with the ionic interaction. However, at physiological intestinal pH range (6.4 to 7.4) and considering chitooligosaccharides pKa, they should be mostly uncharged. This highlights that other type of interaction might be of relevance. In this work, aqueous solutions of chitooligosaccharides with an average degree of polymerization of 10 and 90 % deacetylated, were characterized regarding their effect on bile salt sequestration and cholesterol accessibility. Chitooligosaccharides were shown to bind bile salts to a similar extent as the cationic resin colestipol, both decreasing cholesterol accessibility as measured by NMR at pH 7.4. A decrease in the ionic strength leads to an increase in the binding capacity of chitooligosaccharides, in agreement with the involvement of ionic interactions. However, when the pH is decreased to 6.4, the increase in charge of chitooligosaccharides is not followed by a significant increase in bile salt sequestration. This corroborates the involvement of non-ionic interactions, which was further supported by NMR chemical shift analysis and by the negative electrophoretic mobility attained for the bile salt-chitooligosaccharide aggregates at high bile salt concentrations. These results highlight that chitooligosaccharides non-ionic character is a relevant structural feature to aid in the development of hypocholesterolemic ingredients.publishe

Fine-tuning of defensive behaviors in the dorsal periaqueductal gray by atypical neurotransmitters

This paper presents an up-to-date review of the evidence indicating that atypical neurotransmitters such as nitric oxide (NO) and endocannabinoids (eCBs) play an important role in the regulation of aversive responses in the periaqueductal gray (PAG). Among the results supporting this role, several studies have shown that inhibitors of neuronal NO synthase or cannabinoid receptor type 1 (CB1) receptor agonists cause clear anxiolytic responses when injected into this region. The nitrergic and eCB systems can regulate the activity of classical neurotransmitters such as glutamate and γ-aminobutyric acid (GABA) that control PAG activity. We propose that they exert a ‘fine-tuning’ regulatory control of defensive responses in this area. This control, however, is probably complex, which may explain the usually bell-shaped dose-response curves observed with drugs that act on NO- or CB1-mediated neurotransmission. Even if the mechanisms responsible for this complex interaction are still poorly understood, they are beginning to be recognized. For example, activation of transient receptor potential vanilloid type-1 channel (TRPV1) receptors by anandamide seems to counteract the anxiolytic effects induced by CB1 receptor activation caused by this compound. Further studies, however, are needed to identify other mechanisms responsible for this fine-tuning effect

Interference of environmental factors in serum bilirubin levels - a preliminary study

Bilirubin is a toxic metabolite produced by the normal catabolism of hemoglobin and other proteins. It is also a key marker of liver and hematological disorders. In absence of disease, there are considerable variations of bilirubin levels within subjects that have been reported to be associated with genetic background, but some reports suggest the involvement of environmental factors. The aim of this work was to evaluate the effect of environmental factors that could contribute for the changes of bilirubin levels in a normal Portuguese population. This study was performed in 80 volunteer healthy young adults. Venous blood samples were collected and processed to determine the bilirubin serum levels. A questionnaire was performed which included several parameters, namely: smoking habits, oral contraceptive therapy, caloric intake, fasting status and physical activity. Results showed that: in a population of 17 males and 66 females (average age: 20.3 ± 1.9 years) the mean (± SD) serum bilirubin levels was 10.9 ± 5,5 m mol/L; a trend to higher bilirubin levels was found in males than in females (12.83 ± 5.98 mmol/L vs. 10.77 ± 6.33 mmol/L); higher serum bilirubin levels were found in non-smoking subjects (11.63 ± 6.84 vs 9.58 ± 2.56 mmol/L, p=0.044), and in female subjects that were under oral contraceptive therapy (15.57 ± 9.06 vs. 9.75 ± 4.45 mmol/L, p=0.003). Statistically significant correlations were found between bilirubin serum levels and fasting time (r=0.365, p=0.001), as well as, between bilirubin serum levels and caloric intake (r=-0.254; p=0.021). Multiple regression analysis identified oral contraceptive therapy (b=0.36; p=0.01), smoking status (b=-0.25; p=0.04) and caloric intake (b=0.052; p=0.018) as independent variables significantly associated with total serum bilirubin levels (R2=0.264). Our preliminary data show that bilirubin levels are dependent and influenced by smoking status, caloric intake, fasting time, and oral contraceptive use. Further studies are required to better understand the impact of the environmental factors, besides the genetic background, in the bilirubin serum levels