Tebuconazole-induced toxicity and the protective effect of Ficus carica extract in Neotropical fruit-eating bats.

Tebuconazole (TEB) is a triazole fungicide widely used in agriculture known to cause metabolic and endocrine disorders in mammals. Several plant extracts have shown to be beneficial against pesticide effects due to their hepatoprotective, antioxidant and anti-inflammatory properties. As fruit bats play a critical role in rainforest regeneration and are constantly exposed to pesticides, we aimed at evaluating TEB-induced toxicity and the possible protective effect of the Ficus carica plant extract in Neotropical fruit-eating bats (Artibeus lituratus). Bats were captured and assigned to 4 experimental groups, offered: 1) CTL (n = 6): papaya; 2) DMSO (n = 6): papaya treated with 1.25% dimethyl sulfoxide (DMSO); 3) TEB (n = 6): papaya treated with tebuconazole (commercial formulation) 0.1%; and 4) TEBFC (n = 6): papaya treated with tebuconazole 0.1% and Ficus carica extract (20%) in DMSO (1.25%). After seven days of exposure, TEB bats showed increased lipid peroxidation, increased superoxide dismutase (SOD) and catalase (CAT) activities, vascular congestion and inflammatory infiltrate in the liver, and increased serum transaminase enzyme activities. We found the same alterations in oxidative stress parameters in the breast muscles of TEB-exposed bats. In the testes, all oxidative stress markers were increased in TEB bats and corroborate findings of histopathological and increased serum testosterone levels observed following TEB exposure. The co-administration of the fungicide with the F. carica plant extract attenuated most oxidative stress markers in exposed bats' liver and testes and decreased liver damage, but failed to revert the steroid imbalance caused by the fungicide exposure.

Effects of subchronic exposure to environmentally relevant concentrations of the herbicide atrazine in the Neotropical fish Astyanax altiparanae.

Atrazine (ATZ) is among the most widely used herbicides in the world, and yet it has a potential to contaminate aquatic environments due to pesticide leaching from agricultural areas. In the Neotropical region, studies about the effects of this herbicide in native aquatic wildlife is scarce.Our study aimed at investigating the effects of a 30-day exposure to a commercial atrazine formulation on oxidative stress parameters, histopathology in testis and liver, and hormone levels in males and female of yellow-tailed tetra fish (Astyanax altiparanae). Adults were exposed to low but environmentally relevant concentrations of atrazine as follows: 0 (CTL-control), 0.5 (ATZ0.5), 1 (ATZ1), 2 (ATZ2) and 10 (ATZ10) µg/L. Our results showed decreased GST activity in gills in all groups of exposed animals and increased CAT activity in gills from the ATZ10 group. In the liver, there was an increase in lipid peroxidation in fish from ATZ1 and ATZ2 groups. Histological analysis of the liver showed increased percentage of sinusoid capillaries in ATZ2 fish, increased vascular congestion in ATZ1 and increased leukocyte infiltration in the ATZ10 group. Hepatocyte diameter analysis revealed a decrease in cell size in all groups exposed to ATZ, and a decrease in hepatocyte nucleus diameter in ATZ1, ATZ2 and ATZ10 groups. Endocrine parameters did not show significant changes following ATZ exposure, although an increase of triiodothyronine/thyroxine (T3/T4) ratio was observed in ATZ2 fish. Our results provide evidence that even low, environmentally relevant concentrations of ATZ produced oxidative damage and histological alterations in adult yellow-tailed tetra.

Descriptive morphometry and stereology of the tubular compartment in the wild rodent Hylaeamys megacephalus (Rodentia: Cricetidae) from Central Brazil.

Information on reproductive characteristics of wild rodents is scarce in the literature. This study aimed to assess the testis morphometry and stereology of Hylaeamys megacephalus. We used five animals in the study, captured in forest fragments in southwestern Goias State, between April and August 2009. The testes were fixed in Karnovsky solution, dehydrated, and embedded in methacrylate. Two-micrometer-thick sections from each sample were stained with toluidine blue/sodium borate 1%. Images of the testicular parenchyma were obtained from photomicroscope and morphometric and stereological analyses were carried out using the Image Pro-Plus software. The average body weight observed in the specimens of H. megacephalus in the study was 47.84 g, of which, 0.40% is allocated to the gonads (GSI) and 0.36% to the seminiferous tubules (TSI). These parameters suggest promiscuous reproductive behavior, of the polyandrous type, favoring males with higher sperm production and consequently, larger testes. The volume density of the seminiferous tubules was 94.46%, which represented a volume of 0.18 mL. The volume density and volume of the interstitium were 5.54% and 0.011 mL, respectively. The diameter of the seminiferous tubules was 206.5 µm and the height of seminiferous epithelium was 71.27 µm. H. megacephalus presents 5.06 m of seminiferous tubules and an average of 27.96 m of seminiferous tubules per gram of testis. The mitotic and meiotic indexes showed losses of 85 and 42%, respectively and an overall loss of 90% over the full spermatogenic process. The number of Sertoli cells per testis and per gram of testis was 7.8×10(6) and 95.28×10(6), respectively. Most of the morphometric parameters evaluated in H. megacephalus in this study are within the range of values described for most mammals.

Estrutura e celularidade de meniscos frescos de coelhos (Oryctolagus cuniculus) preservados em glicerina / Structure and cellularity of the fresh menisci (Oryctolagus cuniculus) of rabbits and the menisci preserved in glycerin

No presente estudo foi avaliada a arquitetura tecidual, a população celular, assim como a integridade e a distribuição dos tipos celulares em meniscos frescos de coelhos e preservados em glicerina 98 por cento. Foram analisados meniscos mediais de coelhos recém abatidos, que foram distribuídos em três grupos: o grupo MF (n=7), composto por meniscos frescos, correspondeu ao grupo controle; o grupo MG (n=7), composto por meniscos preservados em glicerina 98 por cento, por 30 dias, e o grupo MR (n=7), por meniscos preservados em glicerina 98 por cento e reidratados em NaCl 0,9 por cento, por 12 horas. Em todos os meniscos foram identificados e quantificados os diferentes tipos celulares: fibroblastos/fibrócitos e condrócitos. A população celular foi estatisticamente semelhante nos três grupos de meniscos, sendo que os meniscos preservados, grupos MG e MR, apresentaram menor intensidade de coloração e retração das fibras colágenas, diminuição de volume e maior intensidade de coloração dos núcleos (condensação da cromatina), em relação aos meniscos frescos (MF), caracterizando o fenômeno de lise celular. A matriz fibrocartilaginosa dos meniscos preservados revelou- se bem preservada mantendo a arquitetura tecidual dos meniscos. Conclui-se que a glicerina 98 por cento é uma opção de meio de preservação para meniscos objetivando aloenxerto, com matriz colágena desvitalizada.

In the present study was evaluated the tissue architecture, the percentage of cellular population, as well as viability and distribution of cells in fresh menisci of rabbits and preserved in 98 percent glycerin. Were analyzed medial menisci of rabbits freshly slaughtered, which were distributed into three groups: the MF group (n=7), composed of fresh menisci, corresponded to the control group; the MG group (n=7), composed by menisci preserved in 98 percent glycerin, for 30 days, and the MR group (n=7) by menisci preserved in 98 percent glycerin and rehydrated in NaCl 0.9 percent for 12 hours. In all menisci were identified and quantified the different cell types: fibroblasts/fibrocytes and condrocytes. The cell population percentage was statistically similar in all groups. All menisci preserved in the MG and MR groups showed a lower intensity of color and shrinkage of collagen fibers, reduced volume and higher intensity of staining of nucleus (chromatin condensation), as compared to fresh menisci (MF), featuring the phenomenon of cell lysis. The cartilaginous matrix of preserved menisci proved to be well preserved because the tissue architecture was maintained. It was concluded that 98 percent glycerin is an optional preservation mean for meniscal allografts with a devitalized collagenous matrix.