Anais da Academia Brasileira de Ciencias最新文献

Disorders of gastrointestinal motility are the major physiologic problem in chagasic megacolon. The contraction mechanism is complex and controlled by different cell types such as enteric neurons, smooth muscle, telocytes, and an important pacemaker of the intestine, the interstitial cells of Cajal (ICCs). The role of ICCs in the progression of acute and chronic Chagas disease remains unclear. In the present work, we investigate the aspects of ICCs in a long-term model of Chagas disease that mimics the pathological aspects of human megacolon. Different subsets of ICCs isolated from Auerbach's myenteric plexuses and muscle layers of control and Trypanosoma cruzi infected animals were determined by analysis of CD117, CD44, and CD34 expression by flow cytometer. Compared with the respective controls, the results showed a reduced frequency of mature ICCs in the acute phase and three months after infection. These results demonstrate for the first time the phenotypic distribution of ICCs associated with functional dysfunction in a murine model of chagasic megacolon. This murine model proved valuable for studying the profile of ICCs as an integrative system in the gut and as a platform for understanding the mechanism of chagasic megacolon development.

Elderly women are more susceptible to the development of chronic non-communicable diseases. Among these, diabetes mellitus (DM) and systemic arterial hypertension (SAH) stand out. This work aimed to carry out an expanded study on the interactions of anthropometric, biochemical and inflammatory parameters associated with the risk of severity in elderly women with hypertension and diabetes. The study involved the evaluation of 126 elderly women with hypertension and diabetes mellitus. The women were divided according disease severity (low, moderate, high and very high). Anthropometric data were collected by bioimpedance analysis. The inflammatory and biochemical data were obtained from volunteer blood samples. Waist circumference, waist circumference/height ratio, and systolic and diastolic pressures increased with severity. Biochemical marker levels increased with risk of severity, except HDLc. In the very high risk group, there was a higher IL-1β, IFN-γ and TNF-α production, however, lower IL-10 levels were observed. The very high risk group showed change values for the IL-10/IL-1β, IL-10/IL-17 and IL-10/TNF-α ratios. The results showed to be extensively altered in the very high risk group, where the inflammatory profile loses its responsiveness. This is the first study that shows an expanded view of the different parameters evaluated in elderly women with hypertension and diabetes.

The ecology of movement is an expanding area, marked by the diversity of analytical methods and protocols, which enables this integrative reading. We investigated movement ecology aspects of Coleodactylus meridionalis in southern Bahia, northeastern Brazil, using fluorescent powder with mineral oil to track individuals. We monitored 69 individuals of C. meridionalis that walked an average distance of 148 cm in 2h. We identified this movement as foraging due to the orientation of the step sequence and microenvironments used. We find no significant differences between walking distance and weight. However, we found a decrease in activity over the follow-up period. Most of the lizard's movements were directed north, while south, east, and west were followed equally. The individuals stayed predominantly on the ground (leaf litter), but it was possible to observe the use of other surfaces, such as trunks and burrows on the ground. Therefore, we studied the movement in three dimensions (ground height, distance traveled, and orientation of steps). We observed the lizard's foraging, one of the most common and least investigated movements in small lizards like C. meridionalis. This involves not only the species' activity schedule but other intrinsic and extrinsic factors that shape the movement decisions of individuals.

The current study proposes to investigate the diversity and phylogeny of trypanosomes parasitizing wild birds from the Brazilian Atlantic Forest. Cytological examination was carried out by light microscopy of blood smears and positive birds were selected for amplification of the 18S rDNA sequence through PCR. The resulting amplicons were subjected to purification, cloning, and sequencing analysis. Phylogenetic reconstruction was conducted, including all avian trypanosomes representative's lineages. A total of ten bird samples from species of Turdus flavipes (N=1/12), T. albicollis (N=1/8), Tachyphonus coronatus (N=6/121), Thamnophilus caerulescens (N=1/22) and Synallaxis spixi (N=1/8) were positive for Trypanosoma spp. In the six specimens of T. coronatus, five distinct lineages of Trypanosoma spp. 18S-rRNA were observed in ninety sequences obtained, and using the strategy of cloning independent PCR, it was possible to observe that two of them were related to T. avium (JB01/JB02), and three were closed related to T. bennetti (JB03/ JB04/JB05). Addionaly, all fifteen sequences obtained from T. caerulescens/ S. spixi/T. flavipes/T. albicollis were identical. The present research is the first study to access molecular diversity and polyparasitism by avian trypanosomes in Brazil. The current research exhibits the wide genetic variability in avian trypanosomes and its non-specific relationship with its avian hosts.

The study evaluated the use of nano copper in semi-purified diets for laying quails and its effect on performance, metabolic state, and bioavailability. A total of 160 (180-days-old) quails were distributed in a completely randomized design, in a 3x3+1 factorial. The copper sources used were copper sulfate, copper oxide, and nano copper oxide, at levels of 200, 400, and 800 ppm each, totaling nine treatments plus a negative control (with no copper inclusion). The following variables were determined: weight gain, feed intake, egg production, egg weight, hemoglobin, hematocrit, Cu in the tissues and Cu bioavailability. Data were subjected to analysis of variance at 5% probability. The effect of sources and levels, as well as the interaction between the factors were evaluated. When interaction was observed, the effect of sources was evaluated separately by the Tukey's test and the effect of levels by regression, both at 5% probability. Copper nano oxide can be used at up to 800 ppm in the diet of laying quails without altering the productive performance, and with higher bioavailability than conventional copper oxide. Hemoglobin increases with the inclusion of 200 and 400 ppm of nano copper oxide and the hematocrit with 400 ppm.

Trophic plasticity is a distinctive feature of freshwater fishes, representing an essential strategy for fish living in resource-variable environments. We analyzed the stomach contents of individuals sampled in two Atlantic Forest streams to identify the primary food sources consumed by Psalidodon aff. fasciatus and verify the existence of spatial, seasonal, and ontogenetic variations. The diet was determined by analyzing the stomach contents using the Volume Method to quantify the importance of food items. In general, Psalidodon aff. fasciatus was classified as an omnivorous species, consuming mainly insects, plant material, and filamentous algae. The results also showed significant effects for all factors considered (spatial, seasonal, and ontogenetic). Finally, Psalidodon aff. fasciatus demonstrated considerable trophic plasticity, which can result in better use of available resources in the environment and improved resource partitioning, reducing intraspecific and interspecific competition.

The genus Flavivirus comprises approximately 80 different viruses. Phylogenetic relationships among its members indicate a clear ecological separation between those viruses transmitted by mosquitoes, ticks, with no known vector, and insect-specific Flaviviruses. The diversity and phylogenetic relationships among insect-specific flaviviruses circulating in the central and northern regions of Argentina were studied by performing molecular detection and characterization of the NS5 protein gene in mosquitoes collected in Córdoba, Chaco and Tucumán provinces. Overall, 68 out of 1776 pools were positive. CxFV, KRV and CFAV circulate in the 3 studied provinces. Several mosquito species (Aedes aegypti, Culex bidens, Cx. dolosus, Cx. interfor, Cx. quinquefasciatus, Cx. saltanensis, Haemagogus spegazzini) were found infected. A wide circulation of CxFV was observed in the central-northern region of Argentina. CxFV strains detected in our study clustered with strains circulating in Santa Fe and Buenos Aires provinces (Argentina), and other countries such as Indonesia, Mexico, Uganda and Taiwan. The presence of these viruses in mosquitoes could play an important role from the public health perspective, because it has been shown that previous CxFV infection can increase or block the infection of the mosquito by other pathogenic flaviviruses.

The following work presents the first study applying the passive acoustic monitoring of anurans at lotic environments for a long time. This study aims to test the efficiency of the passive acoustic monitoring method and active monitoring in detecting anurans in lotic environments of Itinguçu State Park. Specifically, we tested whether species richness differs when comparing active and passive monitoring surveys. Therefore, this study aims to test the efficiency of the passive acoustic monitoring method and active monitoring in detecting anurans in lotic environments of the Itinguçu State Park. The passive acoustic monitoring period was 72 uninterrupted hours at each collection point with intervals of 45 days. Finally, species richness was calculated, and the efficiency of the methods was compared in different scenarios. Our results demonstrated that the park has species that vocalize day and night, but most at night, there is overlapping acoustic niche; waterfall environments harm the quality of recordings; and in lotic environments the active monitoring method was more efficient than the passive acoustic monitoring in all sampling scales. Although the passive acoustic monitoring was not as efficient in a low temporal scale, it tends to increase in efficiency with longer sampling duration.

The objective of this study was to evaluate the effects and economic viability of diets containing different levels of antibiotic and buriti oil (BO) on performance, carcass and cut yields, and relative weight of organs of broilers. A total of 432 one- to 42-day-old male chicks were distributed in a completely randomized experimental design with six treatments, each consisting of six replicates of 12 birds. The treatments consisted of one diet with antibiotic without BO, one diet without antibiotic (DWA) without BO, and four DWA containing increasing levels of BO (0.2, 0.4, 0.6, and 0.8%). Average weight and weight gain (WG) of broilers fed with DWA + BO were similar to those of birds fed control diet. Feed intake and feed conversion (FC) were not different among treatments. Relative weight of pancreas linearly increased in the birds fed diets containing BO. The inclusion of 0.45 and 0.40% of BO in the diets promoted the improvement of WG and FC, respectively. Cost of feed management, ratio, gross margin, and gross income did not differ among treatments. It was concluded that the inclusion of 0.45% of BO in diets without antibiotics is economically feasible and allows recovering the performance of broilers.