Lipid peroxidation and generation of hydrogen peroxide in frozen-thawed ram semen supplemented with catalase or Trolox

Semen manipulation and cryopreservation-thaw procedures may accelerate the generation of reactive oxygen species (ROS). Sperm exposure to large amounts of ROS has been shown to cause membrane lipid peroxidation and cellular injury to the sperm. The objective of this study was to overcome the ROS production in frozen-thawed ram semen by the addition of the antioxidants catalase or Trolox to semen following thawing. Frozen-thawed ram semen (100 x 10(6) sperm/straw) was supplemented with PBS (control group), 100 mu g/ml catalase, or 100 mu M Trolox/10(8) sperm (catalase and Trolox being dissolved in PBS) and incubated (37 degrees C) for 5 min. Under the experimental conditions used in this study, the catalase and Trolox antioxidants failed to protect the sperm from the spontaneous production of ROS. However, when lipid peroxidation was induced by iron (FeSO(4)), the addition of Trolox promoted a reduction (P < 0.05) in the formation of TBARS in the semen, compared to the control and catalase semen samples. The generation of TBARS and H(2)O(2) occurred in the extender alone, without the presence of sperm cells. In conclusion, the addition of Trolox to frozen-thawed ram semen could be beneficial as it decreases the production of TBARS when oxidative stress is induced. It is possible that a longer incubation period could lead to different results. The concentration of catalase also needs to be further evaluated. The extender could contribute to the oxidative stress of sperm, as it is a source of ROS during the cryopreservation of semen. (C) 2010 Elsevier B.V. All rights reserved.

Lipid peroxidation and generation of hydrogen peroxide in frozen-thawed ram semen cryopreserved in extenders with antioxidants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Occurrence of Odontogenic Infections in Patients Treated in a Postgraduation Program on Maxillofacial Surgery and Traumatology

This study assessed the occurrence and characteristics of oral and maxillofacial infections in patients treated at a Brazilian oral and maxillofacial emergency service during a 7-year period. The clinical files of all patients treated at the Oral and Maxillofacial Surgery and Traumatology Service of the Aracatuba Dental School, São Paulo State University, Brazil, between 2002 and 2008 were reviewed. From a population of 3645 patients treated in this period, the study sample consisted of 93 subjects who presented odontogenic infections. Data referring to the patients' sex, age, medical history, and the etiology, diagnosis, complications, drug therapy/treatment, and evolution of the pathologic diseases were collected and analyzed using the Epi Info 2000 software. of these patients, 54 were men (58.1%) and 39 were women (41.9%). Most patients were in the 31- to 40-year-old (20.7%) and 21- to 30-year-old (19.6%) age groups. The most frequent etiology was pulp necrosis due to caries (80.6%). Regarding the treatment, antibiotics were administered to all patients, surgical drainage was done in 75 patients (82.4%), and 44 patients (47.3%) needed hospital admission. First-generation cephalosporin alone or combined with other drugs was the most prescribed antibiotic (n = 26) followed by penicillin G (n = 25). Most patients (n = 85, 91.4%) responded well to the treatment. Five cases had complications: 3 patients needed hospital readmission, 1 case progressed to descending mediastinitis, and 1 patient died. Odontogenic infections can be life-threatening and require hospital admission for adequate patient care. Complications from odontogenic infections, although rare, may be fatal if not properly managed.

Rhamnolipids as biosurfactants from renewable resources: Concepts for next-generation rhamnolipid production

Several microorganisms are known to produce a wide variety of surface-active substances, which are referred to as biosurfactants. Interesting examples for biosurfactants are rhamnolipids, glycolipids mainly known from Pseudomonas aeruginosa produced during cultivation on different substrates like vegetable oils, sugars, glycerol or hydrocarbons. However, besides costs for downstream processing of rhamnolipids, relatively high raw-material prices and low productivities currently inhibit potential economical production of rhamnolipids on an industrial scale. This review focuses on cost-effective and sustainable production of rhamnolipids by introducing new possibilities and strategies regarding renewable substrates. Additionally, past and recent production strategies using alternative substrates such as agro-industrial byproducts or wastes are summarized. Requirements and concepts for next-generation rhamnolipid producing strains are discussed and potential targets for strain-engineering are presented. The discussion of potential new strategies is supported by an analysis of the metabolism of different Pseudomonas species. According to calculations of theoretical substrate-to-product conversion yields and current world-market price analysis, different renewable substrates are compared and discussed from an economical point of view. A next-generation rhamnolipid producing strain, as proposed within this review, may be engineered towards reduced formation of byproducts, increased metabolic spectrum, broadened substrate spectrum and controlled regulation for the induction of rhamnolipid synthesis. (C) 2012 Elsevier Ltd. All rights reserved.

Generation of Nutrients and Detoxification: Possible Roles of Yeasts in Leaf-Cutting Ant Nests.

The possible roles played by yeasts in attine ant nests are mostly unknown. Here we present our investigations on the plant polysaccharide degradation profile of 82 yeasts isolated from fungus gardens of Atta and Acromyrmex species to demonstrate that yeasts found in ant nests may play the role of making nutrients readily available throughout the garden and detoxification of compounds that may be deleterious to the ants and their fungal cultivar. Among the yeasts screened, 65% exhibited cellulolytic enzymes, 44% exhibited pectinolytic activity while 27% and 17% possess enzyme systems for the degradation of protease and amylase, respectively. Galacturonic acid, which had been reported in previous work to be poorly assimilated by the ant fungus and also to have a negative effect on ants' survival, was assimilated by 64% and 79% of yeasts isolated from nests of A. texana and Acromyrmex respectively. Our results suggest that yeasts found in ant nests may participate in generation of nutrients and removal of potentially toxic compounds, thereby contributing to the stability of the complex microbiota found in the leaf-cutting ant nests.

Interaction between Advanced Glycation End Products Formation and Vascular Responses in Femoral and Coronary Arteries from Exercised Diabetic Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

p53, p16 and Fhit Proteins Expressions in Chronic Esophagitis and Chagas Disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A first generation whole genome RH map of the river buffalo with comparison to domestic cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of the vagus nerve in the generation of cardiorespiratory interactions in a neotropical fish, the pacu, Piaractus mesopotamicus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for resonant second generation slepton production at the Fermilab Tevatron

We present a search for supersymmetry in the R-parity violating resonant production and decay of smuons and muon sneutrinos in the channels mu ->chi(0)(1)mu, mu ->chi(0)(2,3,4)mu, and nu(mu)->chi(+/-)(1,2)mu. We analyzed 0.38 fb(-1) of integrated luminosity collected between April 2002 and August 2004 with the D0 detector at the Fermilab Tevatron Collider. The observed number of events is in agreement with the standard model expectation, and we calculate 95% C.L. limits on the slepton production cross section times branching fraction to gaugino plus muon, as a function of slepton and gaugino masses. In the framework of minimal supergravity, we set limits on the coupling parameter lambda(')(211), extending significantly previous results obtained in Run I of the Tevatron and at the CERN LEP collider.

Search for first-generation scalar leptoquarks in p(p)over-bar collisions at root s=1.96 TeV

We report on a search for pair production of first-generation scalar leptoquarks (LQ) in p (p) over bar collisions at root s=1.96 TeV using an integrated luminosity of 252 pb(-1) collected at the Fermilab Tevatron collider by the D0 detector. We observe no evidence for LQ production in the topologies arising from LQ(LQ) over bar -> eqeq and LQ(LQ) over bar -> eq nu q, and derive 95% C.L. lower limits on the LQ mass as a function of beta, where beta is the branching fraction for LQ -> eq. The limits are 241 and 218 GeV/c(2) for beta=1 and 0.5, respectively. These results are combined with those obtained by D0 at root s=1.8 TeV, which increases these LQ mass limits to 256 and 234 GeV/c(2).

Search for pair production of second generation scalar leptoquarks in p(p)over-bar collisions at root s-=1.96 TeV

We report on a search for the pair production of second generation scalar leptoquarks (LQ(2)) in p (p) over bar collisions at the center-of-mass energy, root s = 1.96 TeV, using data corresponding to an integrated luminosity of 294 19 pb(-1) recorded with the DO detector. No evidence for a leptoquark signal in the LQ(2)LQ(2) -> mu q mu q channel has been observed, and upper bounds on the product of cross section times branching fraction were set. This yields lower mass limits of m(LQ2) > 247 GeV/c(2) for beta = B(LQ(2) -> mu q) = 1 and m(LQ2) > 182 GeV/c(2) for beta = 1/2. Combining these limits with previous DO results, the lower limits on the mass of a second generation scalar leptoquark are m(LQ2) > 251 GeV/c(2) and m(LQ2) > 204 GeV/c(2) for beta = I and beta = 1/2, respectively. (c) 2006 Elsevier B.V. All rights reserved.

Mass generation from Lie algebra extensions

Applied to the electroweak interactions, the theory of Lie algebra extensions suggests a mechanism by which the boson masses are generated without resource to spontaneous symmetry breaking. It starts from a gauge theory without any additional scalar field. All the couplings predicted by the Weinberg-Salam theory are present, and a few others which are nevertheless consistent within the model.

The origin of the first and third generation fermion massesin a technicolor scenario

We argue that the masses of the first and third fermionic generations, which are respectively of the order of a few MeV up to a hundred GeV, originate from a dynamical symmetry breaking mechanism leading to masses of the order alphamu, where alpha is a small coupling constant, and mu, in the case of the first fermionic generation, is the scale of the dynamical quark mass (approximate to250 MeV). For the third fermion generation mu is the value of the dynamical techniquark mass (approximate to250 GeV). We discuss how this possibility can be implemented in a technicolor scenario, and how the mass of the intermediate generation is generated.

Resonant production of scalar diquarks at the next generation electron-positron colliders

We investigate the potential of TESLA and JLC/NLC electron-positron linear collider designs to observe diquarks produced resonantly in processes involving hard photons.