Characterization of the oligosaccharides of plasma sex hormone binding globulin from noncirrhotic alcoholic patients

In previous reports we have demonstrated high plasma levels of sex hormone-binding globulin (SHBG) in asymptomatic alcoholic men. In the present work the physicochemical properties of SHBG from plasma of noncirrhotic alcoholic patients have been further compared with SHBG of control subjects. Steroid binding to SHBG was similar for the two groups: alcoholic men, K(d) of 0.62 +/- 0.07 nM and control individuals, K(d) of 0.70 +/- 0.10 nM. The structure of oligosaccharides attached to SHBG from controls and alcoholic men were determined by using serial chromatography. Our data indicated that 7% of SHBG of control individuals was not retarded by the Con-A column, whereas approximately 30% of SHBG of alcoholic men eluted in the void volume of Con A. Approximately 46% of SHBG of alcoholics applied to Con A, possessed biantennary complex oligosaccharides, as indicated by the fact that it could be eluted with methyl-alpha-D-glucopyranoside and by its retention on wheat germ agglutinin; in contrast, when SHBG from control men was analyzed, approximately 51% was eluted with methyl-alpha-D-glucopyranoside. Approximately 9% of the biantennary complex oligosaccharides on SHBG of control men and none of those on SHBG from alcoholic men were fucosylated on the chitobiose core, as determined by chromatography on Lenn culinaris lectin. Galactosylated oligosaccharides were also present on the SHBG fraction as indicated by its interaction with Ricinus communis-I. Approximately 24% of SHBG of alcoholic men and 39% of those on SHBG from control individuals applied to Con-A were retained and could be eluted with methyl-alpha-D-mannopyranoside. Evidence based on the binding on mannoside-eluted SHBG to Con-A, wheat germ agglutinin, and R. communis-I indicated that at least the SHBG in this fraction, from alcoholics or controls, contained two glycosylation sites and that the sites were differentially glycosylated.     

Non-enzymatic in vitro DNA labeling and label immunoquantification

In the present work, a label immunoquantification procedure was developed in order to determine the number of markers introduced into DNA. A non-enzymatic, in vitro labeling method for introducing the p-bromobenzoyl radical (label), through transamination and acylation reactions of the cytidine nucleotides in calf thymus DNA, was carried out. Three spacer arms with different lengths were used for separating the label from the nucleotide and three labeled DNA were obtained. Anti-p-bromobenzoyl chicken IgY polyclonal antibodies were obtained. The antibodies detected the label, into three-labeled DNA, with different sensitivities, in relation to spacer arm length used. About 3-11 labels per 4 x 10(6) bases into thermally denatured DNA were immunoquantified.     

Association of the p53 codon 72 polymorphism to gastric cancer risk in a hight risk population of Costa Rica

Gastric cancer is the second most common cancer associated death cause worldwide. Several factors have been associated with higher risk to develop gastric cancer, among them genetic predisposition. The p53 gene has a polymorphism located at codon 72. which has been associated with higher risk of several types of cancer, including gastric cancer. The aim of this study was to determine the association of p53, codon 72 polymorphism. with the risk of gastric cancer and pre-malignant lesions in a high-risk population from Costa Rica. The genotyping was carried out by PCR-RFLP in 58 gastric cancer patients, 99 controls and 41 individuals classified as group I or II. according to the Japanese histological classification. No association was found for p53. codon 72 polymorphism with neither the risk of gastric cancer nor the risk of less severe gastric lesions in the studied population. Based on this study and taking into account other studies carried out with p53, codon 72 polymorphism. the role of this polymorphismn in the development of gastric cancer remains unclear. De novo mutations on p53 gene produced during neoplasic development of this disease might play a greater role than germinal polymorphisms of the gene. Other polymorphic genes have been associated with higher risk to develop gastric cancer.     

Extracellular Inosine is Modulated by H2O2 and Protects Sertoli Cells against Lipoperoxidation and Cellular Injury

Extracellular purines are involved in the regulation of a wide range of physiological processes, including cytoprotection, ischemic preconditioning, and cell death. These actions are usually mediated via triggering of membrane purinergic receptors, which may activate antioxidant enzymes, conferring cytoprotection. Recently, it was demonstrated that the oxidative stress induced by cisplatin up-regulated A¹ receptor expression in rat testes, suggesting an involvement of purinergic signaling in the response of testicular cells to oxidant injury. In this article, we report the effect of hydrogen peroxide on purinergic agonist release by cultured Sertoli cells. Extracellular inosine levels are strongly increased in the presence of H²O², suggesting an involvement of this nucleoside on Sertoli cells response to oxidant treatment. Inosine was observed to decrease H²O²-induced lipoperoxidaton and cellular injury, and it also preserved cellular ATP content during H²O² exposure. These effects were abolished in the presence of nucleoside uptake inhibitors, indicating that nucleoside internalisation is essential for its action in preventing cell damage.     

The controversial effects of dehydrated powder of Gracilaria birdiae as a food supplement to juvenile male rats

Journal of Applied Phycology - The present study aimed to characterize in vitro antioxidant properties of red algae (Gracilaria birdiae) powder and to investigate its potential protective and...     

Niche measures and growth rate do not predict interspecific variation in spatial synchrony of phytoplankton

Limnology - Spatial synchrony occurs when local populations exhibit correlated dynamics over time. Recent studies, both experimental and observational, have indicated that the magnitude of spatial...     

Tayassu pecari (Link, 1795) (Mammalia,Cetartiodactyla): comments on its South American fossil record,taxonomy and paleobiogeography

Tayassu pecari is widely distributed across the Neotropical region, from northern Argentina to south-eastern Mexico. However, its fossil record is scarce; it is recorded since the middle Pleistocene to Holocene in Argentina, Brazil and Uruguay. This paper aims to: (1) update the systematic synonymy of this species; (2) review and update its geographic chronologic distribution and provide a new Lujanian record of Tayassu pecari in Buenos Aires Province and (3) discuss the paleoenvironmental and paleobiogeographical implications of this record. Considering the quantitative analysis performed, the fossil here recorded clearly integrates the group of Tayassu pecari. This specimen corresponds to the first record of Tayassu pecari in the central-northern region of the Buenos Aires Province. During Late Pleistocene, Tayassu pecari was distributed southern to its recent range, probably evidencing different paleoenvironment conditions. This species is the better adapted peccary to tropical and subtropical rainforests, but may also be present in arid environments. Consequently, Tayassu by itself is insufficient to infer the prevailing environmental conditions. However, according to the fauna associated with the specimen described here, it is possible to infer an open or semi-open and arid or semi-arid environment for the central-northern Buenos Aires region by Late Pleistocene times.     

Assessment of the nursery species pool for restoring landscapes in southeastern Brazil

Brazil has committed to fulfilling international restoration goals and to enforcing environmental legislation that will require private landowners to undertake ecological restoration of 21 million hectares of degraded and deforested landscapes. To support a broad range of restoration practices, a well‐established supply chain capable of representing regional plant diversity is essential. This study investigated the restoration species pool in native plant nurseries in São Paulo state, located in southeastern Brazil, and evaluated their geographic distribution, similarity of their plant stocks, and the proportion of species represented from regional floras. Despite a lack of technical assistance and a significant presence of nonnative species (126 species, average 7.5 species/nursery), we found an impressive native species richness in plant nurseries (561 species, average 86.4 species/nursery) from both the Atlantic Forest and Cerrado domains, representing 38–44% of regional floras. There was a huge bias toward tree and shrub species (96.6%) and an absence or underrepresentation of other growth forms, as well as of savanna specialists, animal‐dispersed, and threatened species. The dissimilarity of species observed among the different nurseries surveyed highlights their role in representing regional diversity, which reflects their regional seed collection practices. Effective assistance and training are essential to address issues related to misidentification of species, underrepresentation of most functional plant groups, and the presence of nonnative species, as well as to support the supply chain, which is currently undergoing a market downturn.