Trace Elements in Plankton, Benthic Organisms, and Forage Fish of Lake Moreno, Northern Patagonia, Argentina

The Northern Patagonian Andean range shared by Chile and Argentina has numerous glacial oligotrophic lakes protected in a series of National Parks. Recent baseline surveys indicated that concentrations in muscle and liver tissues from various fish species from across Nahuel Huapi and Los Alerces National Parks in Argentina were comparable or higher than similar fish species from other parts of the world. As a result, Lake Moreno, in Nahuel Huapi National Park, was chosen to investigate multiple element sinks, trends, and transfer in a representative Patagonia aquatic food web. The metals and metalloids Ag, As, Ba, Br, Cs, Co, Cr, Fe, Hg, K, Na, Rb, Se, and Zn were analyzed in three size plankton fractions, submerged macrophytes, biofilm, insect larvae, amphipods, decapods, gastropods (snails), annelids (earthworms), and forage fish. Except for nanoplankton (10–53 μm; small-celled algae, rotifers) and microplankton (53–200 μm; larger algae, ciliates, zooplankton nauplii), which share elemental compositional similarities, each taxon category had its own distinctive compositional pattern, revealed by principal component analysis. Nano- and microplankton tend to be relatively elevated in some metals, including As, Co, Cr, Fe, Hg, Zn, and Rb, followed by biofilm. Shredder-scrapper Trichoptera (caddisflies) have higher concentration of most of the studied elements than other insect larvae taxa, especially carnivorous Odonata (Anisoptera, dragonflies), which were associated with lower elemental contents. Those trends point to an overall tendency for biodiminishing element concentrations with trophic level in the benthos of Lake Moreno.     

Geostatistical analysis of fruit yield and detachment force in coffee

The aim of this study was to use geostatistical analysis to evaluate the spatial variation in the detachment force of coffee fruit and coffee yield by variograms and kriging for precision agriculture. This study was conducted at Brej?o farm, Três Pontas, Minas Gerais, Brazil. The detachment force of green and mature coffee fruit was measured with a prototype dynamometer and georeferenced. The yield data were obtained from manual harvesting and were georeferenced. The data were evaluated by variograms estimated by residual maximum likelihood (REML), which provided a satisfactory approach for modeling all the variables with a small sample size. Spherical and exponential models were fitted, the first provided the better fit to mature fruit detachment force and the latter provided the better fit to coffee yield and green fruit detachment force. They were used to describe the structure and magnitude of spatial variation in the variables studied. Kriged estimates were obtained with the best fitting variogram models and mapped. The statistical and geostatistical analyses enabled us to characterize the spatial variation of the detachment force of green and mature coffee fruit and coffee yield and to visualize the spatial relations among these variables. The precision agriculture techniques used in this paper to collect, map and analyze the variables studied will help coffee farmers to manage their fields. Maps of coffee yield will enable farmers to apply nutrients site-specifically and manage harvesting either manually or mechanically. In addition, maps of detachment force of coffee fruit can enable farmers to harvest coffee selectively by choosing the appropriate places and the right time to start. This will improve the quality of the final product and also increase profits.     

In vitro culture of bovine embryos in murine ES cell conditioned media negatively affects expression of pluripotency-related markers OCT4, SOX2 and SSEA1

Despite extensive efforts, establishment of bovine embryonic stem (ES) cell lines has not been successful. We hypothesized that culture conditions for in vitro-produced (IVP) embryos, the most used source of inner cell mass (ICM) to obtain ES cells, might affect their undifferentiated state. Therefore, the aim of this work was to improve pluripotency of IVP blastocysts to produce suitable ICM for further culturing. We tested KSR and foetal calf serum (FCS) supplements in SOF medium and ES cell conditioned medium (CM) on IVC (groups: KSR, KSR CM, FCS and FCS CM). Cleavage and blastocyst rates were similar between all groups. Also, embryonic quality, assessed by apoptosis rates (TUNEL assay), total cell number and ICM percentage did not differ between experimental groups. However, expression of pluripotency-related markers was affected. We detected down-regulation of OCT3/4, SOX2 and SSEA1 in ICM of FCS CM blastocysts (p < 0.05). SOX2 gene expression revealed lower levels (p < 0.05) on KSR CM blastocysts and a remarkable variation in SOX2 mRNA levels on FCS-supplemented blastocysts. In conclusion, pluripotency-related markers tend to decrease after supplementation with ES cell CM, suggesting different mechanisms regulating mouse and bovine pluripotency. KSR supplementation did not differ from FCS, but FCS replacement by KSR may produce blastocysts with stable SOX2 gene expression levels.     

Intraocular signet-ring cell melanoma in a hamster (Cricetulus griseus)

A two‐and‐a‐half year‐old male Chinese hamster (Cricetulus griseus) was referred for evaluation of an intraorbital mass involving the right eye. Based on ophthalmic examination and ultrasonography, a diagnosis of intraocular neoplasia was made. Enucleation of the affected eye was performed. The mass was histologically diagnosed as a primary malignant intraocular signet‐ring cell melanoma. No signs of recurrence were detected, and the hamster remained clinically healthy until it died 6 months after surgery. This case report attempts to contribute to the limited body of knowledge available in the literature on primary intraocular neoplasms in hamsters.     

Acute heat stress impairs performance parameters and induces mild intestinal enteritis in broiler chickens: role of acute hypothalamic-pituitary-adrenal axis activation

Studies on the environmental consequences of stress are relevant for economic and animal welfare reasons. We recently reported that long-term heat stressors (31 ± 1°C and 36 ± 1°C for 10 h/d) applied to broiler chickens (Gallus gallus domesticus) from d 35 to 42 of life increased serum corticosterone concentrations, decreased performance variables and the macrophage oxidative burst, and produced mild, multifocal acute enteritis. Being cognizant of the relevance of acute heat stress on tropical and subtropical poultry production, we designed the current experiment to analyze, from a neuroimmune perspective, the effects of an acute heat stress (31 ± 1°C for 10 h on d 35 of life) on serum corticosterone, performance variables, intestinal histology, and peritoneal macrophage activity in chickens. We demonstrated that the acute heat stress increased serum corticosterone concentrations and mortality and decreased food intake, BW gain, and feed conversion (P < 0.05). We did not find changes in the relative weights of the spleen, thymus, and bursa of Fabricius (P > 0.05). Increases in the basal and the Staphylococcus aureus-induced macrophage oxidative bursts and a decrease in the percentage of macrophages performing phagocytosis were also observed. Finally, mild, multifocal acute enteritis, characterized by the increased presence of lymphocytes and plasmocytes within the lamina propria of the jejunum, was also observed. We found that the stress-induced hypothalamic-pituitary-adrenal axis activation was responsible for the negative effects observed on chicken performance and immune function as well as for the changes in the intestinal mucosa. The data presented here corroborate with those presented in other studies in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.     

Apoptosis in T lymphocytes from spleen tissue and peripheral blood of L. (L.) chagasi naturally infected dogs

Dogs are the main domestic reservoirs of L. (L.) chagasi. Once in the vertebrate host, the parasite may cause visceral leishmaniasis, which can also be transmitted to humans. Infected symptomatic dogs show disorganization in the white pulp in spleen tissue and a reduction in T lymphocytes in peripheral blood. To investigate whether apoptosis is involved in white pulp disorganization and diminished T cell counts in peripheral blood, apoptotic T cells from the spleen and peripheral blood of dogs naturally infected with L. (L.) chagasi and presenting clinical manifestations were quantified and compared with healthy dogs. Thirteen symptomatic adult dogs infected by L. (L.) chagasi and six healthy dogs from a nonendemic area (controls) were included in the study. Samples from spleen and peripheral blood were used to quantify apoptosis in CD3 lymphocytes by flow cytometry using Anexin V and Multicaspase kits; the results were compared using the Mann Whitney test. The percentage of total T cells was lower in Leishmania infected dogs compared to healthy controls (P<0.05). Apoptosis levels in T cells from PBMC and spleen were higher in infected dogs than in controls (P<0.05). The least squares method test was used to determine the effect between the degree of structural organization of spleen white pulp and the percentage of apoptosis in the spleen. A significant effect on the level of white pulp morphological disorganization and percentage of apoptosis in spleen T cells was observed (F=20.45; P=0.0014). These data suggest that apoptosis is an important for the immunopathogenesis of canine visceral leishmaniasis.     

Biological control of goat gastrointestinal helminthiasis by Duddingtonia flagrans in a semi-arid region of the northeastern Brazil

The aim of this study was to test a pellet formulation in a sodium alginate matrix of Duddingtonia flagrans in the biological control of goat gastrointestinal helminths kept in a native pasture in a semi-arid region of Paraíba state, northeastern Brazil. An area of 2.4 ha was divided into three paddocks, where groups of seven goats ware formed. Each group received the following treatments during the months of March to August 2011: D. flagrans group, received 3g of pellets containing D. flagrans (AC001) for each 10 kg/l.w., twice a week; Moxidectin 0.2% group, received 0.2mg/kg of Moxidectin 0.2% orally, every 30 days; Control group, received 3g of pellets without fungi per 10 kg/l.w., twice a week. Each month, a tracer goat was placed in each group for 30 days and then sacrificed and necropsied. The D. flagrans group showed a greater reduction in EPG, increased weight gain, higher rates of packed cell volume and lower parasitic load burden in the tracer goats compared to Moxidectin 0.2% and Control groups. D. flagrans was efficient in controlling goat gastrointestinal helminthiasis in a semi-arid region of northeastern Brazil.     

Prevalence, risk factors, and biochemical markers in dogs with ultrasound-diagnosed biliary sludge

Regarded as an incidental finding, biliary sludge is often diagnosed in dogs on abdominal ultrasound. The aims of the present study were to assess the risk factors, biochemical markers and ultrasonographic findings and to estimate the prevalence and influence of different breeds, sexes, and ages on biliary sludge in dogs. Results demonstrate that the prevalence of biliary sludge is high, especially in senior dogs. The biochemical markers did not have a significant correlation with biliary sludge, and the type of diet was not considered to be the major risk factor. Hepatomegaly was frequently observed on the ultrasound scan of affected animals and of dogs on different systemic drugs and with cardiopathies, which have been referred to as risk groups for the development of inspissated bile.     

The effect of IGF-1 and FSH on the in vitro development of caprine secondary follicles and on the IGF-1, IGFR-I and FSHR mRNA levels

This study verified the in vitro effects of IGF-1, FSH or both on caprine preantral follicle development and mRNA levels encoding IGF-1, IGFR-1 and FSHR. Secondary follicles were cultured for six days with FSH, IGF-1 or IGF-1+FSH. The results showed that IGF-1 and/or FSH addition did not influence follicular development for six days. The interaction between IGF-1 and FSH increased the mRNA levels of IGF-1 and FSHR, and FSH increased the expression of the IGFR-1 mRNA. Thus, IGF-1 and/or FSH increased IGF-1, IGFR-1 and FSHR mRNA levels in in vitro cultured caprine secondary follicles, but they did not influence their development after six days of in vitro culture.