New miRNA labeling method for bead-based quantification

Background  

microRNAs (miRNAs) are small single-stranded non-coding RNAs that act as crucial regulators of gene expression. Different methods have been developed for miRNA expression profiling in order to better understand gene regulation in normal and pathological conditions. miRNAs expression values obtained from large scale methodologies such as microarrays still need a validation step with alternative technologies.     

Cougar Predation on Black-and-Gold Howlers on Mutum Island,Southern Brazil<Superscript>1</Superscript>

Researchers consider predation rates by terrestrial animals to be lower in the case of arboreal primates, particularly among large-bodied species. We recorded the consumption of black-and-gold howlers (Alouatta caraya) by cougars (Puma concolor) as evidence of predation on an island of the upper Paraná River. We collected and processed fecal samples of the felid in 2004 and 2005. We identified items in the laboratory by comparison with museum specimens. We considered each species in a fecal sample as a single occurrence. Based on analysis of the cuticle scale pattern, we identified the felid as cougar. Howlers occurred in 4 out of the 8 fecal samples (40% of the occurrences). In addition to howlers, we also recorded 5 occurrences of agouti (Dasyprocta azarae; 50%) and a small unidentified sigmodontine rodent (10%). The abundance of howlers and the low forest canopy in a successional vegetation might have facilitated the predation of the large primates by a primarily terrestrial predator. The versatility of cougars is corroborated by the consumption of prey species that were abundant in the region and that were available in different forest strata, such as howlers and agoutis.     

Paracoccidioidomycosis in wild monkeys from Paraná State, Brazil

The aim of this study was to evaluate the seroprevalence of Paracoccidioides brasiliensis infection in wild New World monkeys (Cebus sp. and Alouatta caraya). A total of 93 animals (Cebus sp., n = 68 and Alouatta caraya, n = 25) were captured in the Paraná River basin, Paraná State, Brazil and the serum samples were analyzed by ELISA and immunodiffusion using P. brasiliensis gp43 and exoantigen as antigens, respectively. The seropositivity observed by ELISA was 44.1% and 60% for Cebus sp. and A. caraya, respectively, while by immunodiffusion test Cebus sp. showed positivity of 2.9% only. No significant difference was observed in relation to age and sex. This is the first report of paracoccidioidomycosis in wild capuchin monkeys and in wild-black and golden-howler monkeys. The high positivity to P. brasiliensis infection in both species evaluated in our study and the positivity by immunodiffusion test in Cebus sp. suggest that natural disease may be occurring in wild monkeys living in paracoccidioidomycosis endemic areas.     

Species distribution and antifungal susceptibility patterns of <Emphasis Type="Italic">Candida</Emphasis> spp. bloodstream isolates from a Brazilian tertiary care hospital

In this work, we collect data from surveys of bloodstream Candida isolates performed in Brazil from 1996 to 2004. Besides, we analyzed the species distribution of bloodstream Candida isolates together with potential risk factors for candidemia and the susceptibility profile of these isolates in patients from Hospital das Clínicas in Goiania city, Brazil. Blood samples were collected in the admission day and on every 7 days, in the intensive care unit (ICU) of a tertiary hospital. Candida isolates were identified by standard protocols that included germ tube formation, chlamydoconidia production on cornmeal agar and sugar fermentation and assimilation tests. Data of patients were recorded and analyzed according to age at the time of diagnosis, gender and presence of potential risk factors. Statistical analysis was used to determine if the time of hospital permanence increased Candida colonization in ICU patients’ blood. The antifungal susceptibility testing was performed by broth microdilution method according to document NCCLS/CLSI M27–A2. Among the 345 blood samples cultured, candidemia was recovered in 33 patients, which were isolated 51.5% of Candida non-albicans. Fungemia was associated with long-term hospitalization. Fluconazole, itraconzole, voriconazole and amphotericin B exhibited a potent activity against all isolates of Candida. Voriconazole MICs were much low for all isolates tested. This work confirms data of increase of Candida non-albicans species in bloodstream in ICU and shows that voriconazole in vitro activity was higher than those of itraconazole, fluconazole and amphotericin B.     

Epidemiology, Relative Invasive Ability, Molecular Characterization, and Competitive Performance of Campylobacter jejuni Strains in the Chicken Gut

One hundred forty-one Campylobacter jejuni isolates from humans with diarrhea and 100 isolates from retailed poultry meat were differentiated by flaA typing. The bacteria were isolated in a specific geographical area (Dunedin) in New Zealand over a common time period. Twenty nine flaA types were detected, one of which (flaA restriction fragment length polymorphism type 15 [flaA-15]) predominated among isolates from humans (~30% of isolates). This strain was of low prevalence (5% of isolates) among poultry isolates. flaA-15 strains were five to six times more invasive of HEp2 cells in an in vitro assay than a flaA type (flaA-3) that was commonly encountered on poultry meat (23% of isolates) but was seldom associated with human illness (5%). Competitive-exclusion experiments with chickens, utilizing real-time quantitative PCR to measure the population sizes of specific strains representing flaA-15 (T1016) and flaA-3 (Pstau) in digesta, were carried out. These experiments showed that T1016 always outcompeted Pstau in the chicken intestine. Genomic comparisons of T1016 and Pstau were made using DNA microarrays representing the genome of C. jejuni NCTC 11168. These comparisons revealed differences between the strains in the gene content of the Cj1417c-to-Cj1442c region of the genome, which is associated with the formation of capsular polysaccharide. The strains differed in Penner type (T1016, O42; Pstau, O53). It was concluded that poultry meat was at least one source of human infection with C. jejuni, that some Campylobacter strains detected in poultry meat are of higher virulence for humans than others, and that bacterial attributes affecting strain virulence and commensal colonization ability may be linked.     

Muscle delta13C change in Nile tilapia (Oreochromis niloticus) fingerlings fed on C3-or C4-cycle plants grain-based diets

The effects of grain-based diets from C3 or C4-cycle plants on muscle delta(13)C change process in Nile tilapia (Oreochromis niloticus) fingerlings were investigated. Two groups of sex reversal males Nile tilapia fingerlings were fed with isoproteic (32.0% DP) and isocaloric (3200 kcal DE/kg) diets, differing from each other by their delta(13)C. Muscle samples were collected and the carbon isotopic composition was measured. For C4 diet, the formula for the muscle delta(13)C change related to the intake time of a new diet was delta(13)C=-14.88-9.21e(-0.0209t) and the half-life (T) of the muscle carbon was 33.2 days. For C3 diet, the formula was delta(13)C=-25.43+8.59e(-0.0533t) with T=13 days. The C3 diet was considered more appropriate based on its palatability and consequent larger food intake than the C4 diet, resulting in an increased muscle delta(13)C change rate. However, for future studies, would be necessary to mix both the C3 and C4 feedstuffs to formulate diets nutritionally appropriated, with contrasting stable isotopes signatures. Tissue delta(13)C change rate is therefore indicated as a promising tool to better understand the biotic and abiotic factors that influence nutrients utilization from the diet and animal growth.     

Cell-based tissue engineering for lung regeneration

Emphysema is a chronic lung disease characterized by alveolar enlargement and tissue loss. Tissue engineering represents an attractive potential for regeneration of several organ systems. The complex three-dimensional architectural structure of lung parenchyma requiring connections of alveolar units to airways and the pulmonary circulation makes this strategy less optimistic. In the present study, we used Gelfoam sponge as a scaffold material, supplemented with fetal rat lung cells as progenitors, to explore the potential application of cell-based tissue engineering for lung regeneration in adult rats. After injection into lung parenchyma, the sponge showed porous structures similar to alveolar units. It did not induce severe local inflammatory response. Fetal lung cells in the sponge were able to survive in the adult lung for at least 35 days, determined by CMTMR [5-(and-6)-{[(4-chloromethyl)benzoyl]amino}tetramethylrhodamine] labeling. Proliferation of cells within the sponge was demonstrated in vivo by bromodeoxyuridine (BrdU) labeling. Cells formed "alveolar-like structures" at the border between the sponge and the surrounding lung tissue with positive immunohistochemical staining for epithelial and endothelial cells. Neovascularization of the sponge was demonstrated with India ink perfusion. The sponge degraded after several months. This study suggests that cell-based tissue engineering possesses the potential to regenerate alveolar-like structures, an important step towards our ultimate goal of lung regeneration.     

Colonic healing after portal ischemia and reperfusion: an experimental study with oxidative stress biomarkers

This experimental study aimed to evaluate colon healing after portal ischemia followed by reperfusion. Seventy male Wistar rats randomly distributed in four groups were used: Group 1, colonic anastomosis (n = 20); Group 2, portal ischemia-reperfusion (n = 20); Group 3, colonic anastomosis and portal ischemia-reperfusion (n = 20); and Group 4, control (n = 10). In the postoperative period, these rats were re-allocated into subgroups and lipid peroxidation and protein oxidation plasma levels were evaluated on days 1 and 5 by thiobarbituric acid reactive substances (TBARS) and slot-blotting assays, respectively. A segment of the right colon was also removed for collagen analysis. Both malondialdehyde (MDA) and protein carbonyl levels (oxidative markers of lipids and proteins) presented a significant increase after reperfusion in Group 3 on days 1 (P < 0.002) and 5 (P < 0.0001). In this same group, an extensive inflammatory process showing decreased fibroplasia was observed, with deficiency in collagen deposition on both sides of the anastomosis edges. Taken together, these results indicate that portal congestion followed by reperfusion induces an oxidative stress, which impaired the mechanism of colon anastomotic healing.     

Squamate richness in the Brazilian Cerrado and its environmental–climatic associations

We investigate patterns of species richness of squamates (lizards, snakes, and amphisbaenians) in the Brazilian Cerrado, identifying areas of particularly high richness, and testing predictions of large‐scale richness hypotheses by analysing the relationship between species richness and environmental climatic variables. We used point localities from museum collections to produce maps of the predicted distributions for 237 Cerrado squamate species, using niche‐modelling techniques. We superimposed distributions of all species on a composite map, depicting richness across the ecosystem. Then, we performed a multiple regression analysis using eigenvector‐based spatial filtering (Principal Coordinate of Neighbour Matrices) to assess environmental–climatic variables that are best predictors of species richness. We found that the environmental–climatic and spatial filters multiple regression model explained 78% of the variation in Cerrado squamate richness (r² = 0.78; F = 32.66; P < 0.01). Best predictors of species richness were: annual precipitation, precipitation seasonality, altitude, net primary productivity, and precipitation during the driest quarter. A model selection approach revealed that several mechanisms related to the different diversity hypothesis might work together to explain richness variation in the Cerrado. Areas of higher species richness in Cerrado were located mainly in the south‐west, north, extreme east, and scattered areas in the north‐west portions of the biome. Partitioning of energy among species, habitat differentiation, and tolerance to variable environments may be the primary ecological factors determining variation in squamate richness across the Cerrado. High richness areas in northern Cerrado, predicted by our models, are still poorly sampled, and biological surveys are warranted in that region. The south‐western region of the Cerrado exhibits high species richness and is also undergoing high levels of deforestation. Therefore, maintenance of existing reserves, establishment of ecological corridors among reserves, and creation of new reserves are urgently needed to ensure conservation of species in these areas.