Expression of Arabidopsis Bax Inhibitor‐1 in transgenic sugarcane confers drought tolerance

The sustainability of global crop production is critically dependent on improving tolerance of crop plants to various types of environmental stress. Thus, identification of genes that confer stress tolerance in crops has become a top priority especially in view of expected changes in global climatic patterns. Drought stress is one of the abiotic stresses that can result in dramatic loss of crop productivity. In this work, we show that transgenic expression of a highly conserved cell death suppressor, Bax Inhibitor‐1 from Arabidopsis thaliana (AtBI‐1), can confer increased tolerance of sugarcane plants to long‐term (>20 days) water stress conditions. This robust trait is correlated with an increased tolerance of the transgenic sugarcane plants, especially in the roots, to induction of endoplasmic reticulum (ER) stress by the protein glycosylation inhibitor tunicamycin. Our findings suggest that suppression of ER stress in C₄ grasses, which include important crops such as sorghum and maize, can be an effective means of conferring improved tolerance to long‐term water deficit. This result could potentially lead to improved resilience and yield of major crops in the world.     

Novel point mutations in the ERG11 gene in clinical isolates of azole resistant Candida species

The azoles are the class of medications most commonly used to fight infections caused by Candida sp. Typically, resistance can be attributed to mutations in ERG11 gene (CYP51) which encodes the cytochrome P450 14α-demethylase, the primary target for the activity of azoles. The objective of this study was to identify mutations in the coding region of theERG11 gene in clinical isolates of Candidaspecies known to be resistant to azoles. We identified three new synonymous mutations in the ERG11 gene in the isolates of Candida glabrata (C108G, C423T and A1581G) and two new nonsynonymous mutations in the isolates of Candida krusei - A497C (Y166S) and G1570A (G524R). The functional consequence of these nonsynonymous mutations was predicted using evolutionary conservation scores. The G524R mutation did not have effect on 14α-demethylase functionality, while the Y166S mutation was found to affect the enzyme. This observation suggests a possible link between the mutation and dose-dependent sensitivity to voriconazole in the clinical isolate of C. krusei. Although the presence of the Y166S in phenotype of reduced azole sensitivity observed in isolate C. kruseidemands investigation, it might contribute to the search of new therapeutic agents against resistant Candida isolates.     

Impact of dietary selenium intake on cardiac health: experimental approaches and human studies

Selenium, a dietary trace mineral, essential for humans and animals, exerts its effects mainly through its incorporation into selenoproteins. Adequate selenium intake is needed to maximize the activity of selenoproteins, among which glutathione peroxidases have been shown to play a major role in cellular defense against oxidative stress initiated by excess reactive oxygen species. In humans, a low selenium status has been linked to increased risk of various diseases, including heart disease. The main objective of this review is to present current knowledge on the role of selenium in cardiac health. Experimental studies have shown that selenium may exert protective effects on cardiac tissue in animal models involving oxidative stress. Because of the narrow safety margin of this mineral, most interventional studies in humans have reported inconsistent findings. Major determinants of selenium status in humans are not well understood and several nondietary factors might be associated with reduced selenium status. In this review, we discuss recent studies regarding the role of selenoproteins in the cardiovascular system, the effect of dietary intake on selenium status, the impact of selenium status on cardiac health, and the cellular mechanisms that can be involved in the physiological and toxic effects of selenium.     

Immunohistochemical analysis of smooth muscle cells and volumetric density of the elastic system fibers of wild boar (Sus scrofa) penis

The purpose of the present study was to verify the smooth muscle cell distribution and elastic system fibers volumetric density (Vv) in the corpus spongiosum and corpus cavernosum of the wild boar penis. Adult wild boars (n=13) were used. The penile mid shaft fragments were fixed with 4% phosphate buffered formalin solution and/or Bouin's liquid during 24-48 h, and processed using standard histological techniques. The sections were stained with Weigert's Resorcin-Fucsin with previous oxidation. The elastic system fibers Vv was determined in 25 random fields of each fragment using M42 test system. For immunohistochemical analysis, monoclonal anti-alpha actin smooth muscle was used. The histochemical methods detected elastic system fibers in both corpus spongiosum and corpus cavernosum of all animals. The elastic fibers Vv average was 36.6%+/-0.9 for corpus spongiosum and 11.7%+/-0.5 for corpus cavernosum. Through immunocitochemistry, a small quantity of smooth muscle cells was visualized in intimate relationship with blood vessels wall. The great amount of elastic fibers and the smooth muscle cell distribution beneath the endothelium suggest that these fibers may have an important role in penile erection process in the penis of wild boars.     

Effect of stress-induced lipid peroxidation on functions of rat peritoneal macrophages

The aim of the present study was to investigate the effects of stress-induced lipid peroxidation on macrophages' functions. Animals were subjected to 4 h immobilization at 4 degrees C in restraining devices. The peritoneal macrophages obtained from rats exposed to cold and restraint stress exhibited an increase in lipid peroxidation and a decline of chemotaxis and phagocytosis compared with control rats. After supplementation with vitamin E, the increment in thiobarbituric acid reactive substances (TBARS) content as the oxidative stress marker and the decline of chemotaxis and phagocytosis in peritoneal macrophages observed during cold-restraint stress was significantly removed. No significant change in catalase activity of peritoneal macrophages was observed in groups exposed to cold-restraint stress and treated with vitamin E. These findings indicate that phagocytic and chemotactic capacities of peritoneal macrophages are decreased by cold-restraint stress and this effect of stress may be related to lipid peroxidation.     

Spermatogenesis in goats with and without scrotum bipartition

The objective of the present research was to quantify the seminiferous epithelium cells, spermatogenesis efficiency and characterize the ultrastrucure of Sertoli cells in goats. Eighteen goats were used and divided into three groups: Group I - goats without bipartition of the scrotum; Group II - animals with bipartition of the scrotum in up to 50% of the testicular length; Group III - goats with bipartition of the scrotum in more than 50% of the testicular length. The goat testes in Group III had a greater number of primary spermatocytes (25.37 ± 4.55 cells per cross sections), spermatids (112 ± 15.12 cells per cross sections), and Sertoli cells (9.46 ± 1.74 cells per cross sections) than the animals in Groups I and II (P<0.05). The spermatogenic mitotic, meiotic, and general efficiency were greater in animals in Group III (1.25 ± 0.28; 5.12 ± 1.63; 6.44 ± 1.96) when compared to those in Groups I and II. Sheet-like processes originated from the Sertoli cell body as simple and smooth structures which involved almost all the surface of germ cells. Slender cord-like processes originated from Sertoli cells and also from the sheet-like processes. The relative frequency of the cycle stages showed differences among the groups of goats studied, and the highest frequency was in Stage 3 (20.68% for goats in Group I, 21.15% for those in Group II, and 16.89% for the animals in Group III). In conclusion, goats with bipartition of the scrotum have a greater number of germ and Sertoli cells per cross section of seminiferous tubule, that indicated a greater sperm production when compared to the other groups, and the ultrastructure of the Sertoli cell process did not present any relationship with bipartition of the scrotum.     

Tamoxifen Ameliorates Peritoneal Membrane Damage by Blocking Mesothelial to Mesenchymal Transition in Peritoneal Dialysis

Mesothelial-to-mesenchymal transition (MMT) is an auto-regulated physiological process of tissue repair that in uncontrolled conditions such as peritoneal dialysis (PD) can lead to peritoneal fibrosis. The maximum expression of peritoneal fibrosis induced by PD fluids and other peritoneal processes is the encapsulating peritoneal sclerosis (EPS) for which no specific treatment exists. Tamoxifen, a synthetic estrogen, has successfully been used to treat retroperitoneal fibrosis and EPS associated with PD. Hence, we used in vitro and animal model approaches to evaluate the efficacy of Tamoxifen to inhibit the MMT as a trigger of peritoneal fibrosis. In vitro studies were carried out using omentum-derived mesothelial cells (MCs) and effluent-derived MCs. Tamoxifen blocked the MMT induced by transforming growth factor (TGF)-β1, as it preserved the expression of E-cadherin and reduced the expression of mesenchymal-associated molecules such as snail, fibronectin, collagen-I, α-smooth muscle actin, and matrix metalloproteinse-2. Tamoxifen-treatment preserved the fibrinolytic capacity of MCs treated with TGF-β1 and decreased their migration capacity. Tamoxifen did not reverse the MMT of non-epitheliod MCs from effluents, but it reduced the expression of some mesenchymal molecules. In mice PD model, we demonstrated that MMT progressed in parallel with peritoneal membrane thickness. In addition, we observed that Tamoxifen significantly reduced peritoneal thickness, angiogenesis, invasion of the compact zone by mesenchymal MCs and improved peritoneal function. Tamoxifen also reduced the effluent levels of vascular endothelial growth factor and leptin. These results demonstrate that Tamoxifen is a therapeutic option to treat peritoneal fibrosis, and that its protective effect is mediated via modulation of the MMT process.