Melatonin in maturation media fails to improve oocyte maturation, embryo development rates and DNA damage of bovine embryos

Melatonin (MEL) acts as a powerful scavenger of free radicals and direct gonadal responses to melatonin have been reported in the literature. Few studies, however, have evaluated the effect of MEL during in vitro maturation (IVM) on bovine embryos. This study tested the addition of MEL to maturation medium (MM) with no gonadotropins on nuclear maturation and embryo development rates and the incidence of DNA damage in resulting embryos. Cumulus-oocyte complexes were aspirated from abattoir ovaries and cultured in MM (TCM-199 medium supplemented with 10% fetal calf serum - FCS) at 39ºC and 5% CO2 in air. After 24 hours of culture in MM with 0.5 µg mL-1 FSH and 5.0 µg mL-1 LH; 10-9 M MEL) or 10-9 M MEL, 0.5 µg mL-1 FSH and 5.0 µg mL-1 LH, the oocytes were stained with Hoechst 33342 to evaluate nuclear maturation rate. After in vitro fertilization and embryo culture, development rates were evaluated and the blastocysts were assessed for DNA damage by Comet assay. There was no effect of melatonin added to the MM, alone or in combination with gonadotropins, on nuclear maturation, cleavage and blastocyst rates. These rates ranged between 88% to 90%, 85% to 88% and 42% to 46%, respectively. The extent of DNA damage in embryos was also not affected by MEL supplementation during IVM. The addition of 10-9 M MEL to the MM failed to improve nuclear maturation and embryo development rates and the incidence of DNA damage in resulting embryos, but was able to properly substitute for gonadotropins during IVM.

Sensitivity to halothane and its relationship to the development of PSE (Pale, Soft, Exudative) meat in female lineage broilers

This work aimed to evaluate female lineage broilers for halothane sensitivity and for their susceptibility to the subsequent development of PSE meat. The halothane test was carried out in an anesthetic chamber with 3.0% halothane. The unconscious birds were examined for leg muscle rigidity. If one or both legs became extended and rigid, the birds were classified as halothane sensitive (HAL+), while unresponsive birds were classified as halothane negative (HAL-). The results showed that of 298 birds aged 42 days old, 95.6% were HAL- and 4.4% were HAL+. A sample of pectoralis major muscle was collected from HAL- (n=105) and HAL+ (n=13) birds. The pH and breast fillet color were determined at 4ºC, 24 hours post-mortem. Interestingly, only 2.5% of HAL+ birds displayed PSE meat characteristics compared to 12.7% of HAL- individuals. The halothane test demonstrated that female lineage broilers displayed very little sensitivity towards halothane, indicating that the development of PSE meat is related to other environmental factors.

Desidratação e recomendações para a reposição hídrica em crianças fisicamente ativas

OBJETIVO: A prática de exercícios físicos, devido à produção inerente de calor, pode conduzir à desidratação. A maioria dos estudos que abordam os riscos da desidratação e fornecem recomendações de reposição hídrica é direcionada a indivíduos adultos residentes em regiões de clima temperado, porém, em regiões tropicais, pouco é conhecido sobre as necessidades de reposição hídrica em crianças fisicamente ativas. Esta revisão discute as recomendações para esta população e estabelece os riscos da prática esportiva em ambiente de clima tropical. FONTES DE DADOS: Análise sistemática com levantamento da literatura nacional (SciELO) e internacional (Medline) de artigos publicados entre 1972 e 2009, com os seguintes descritores isolados ou em combinação: hidratação, crianças, desidratação e reposição hídrica. Foram selecionados artigos publicados nas línguas portuguesa e inglesa. SÍNTESES DE DADOS: Observou-se que há riscos de desidratação e possível desenvolvimento de um quadro de hipertermia principalmente se as crianças são submetidas a condições climáticas desfavoráveis sem reposição hídrica adequada. O principal fator desencadeante da hipertermia é a menor adaptação das crianças aos extremos de temperatura, em comparação aos adultos, por possuírem área maior de superfície corporal e capacidade menor de termorregulação por evaporação. CONCLUSÕES: Conhecidos os fatores intervenientes da desidratação, a melhor recomendação, perante uma condição climática sabidamente desfavorável, é estabelecer um plano impositivo de hidratação com bebida com sabor e acréscimo de carboidratos e sódio, evitando-se uma perda hídrica significativa, diminuição da performance e, principalmente, com o objetivo de reduzir os riscos à saúde impostos pela hipertermia e desidratação a crianças fisicamente ativas.

Two-dimensional gel electrophoretic protein profile analysis during seed development of Ocotea catharinensis: a recalcitrant seed species

The aim of the present work was to characterize changes in the protein profile throughout seed development in O. catharinensis, a recalcitrant species, by two-dimensional gel electrophoresis. Protein extraction was undertaken by using a thiourea/urea buffer, followed by a precipitation step with 10% TCA. Comparative analysis during seed development showed that a large number of proteins were exclusively detected in each developmental stage. The cotyledonary stage, which represents the transition phase between embryogenesis and the beginning of metabolism related to maturation, presents the highest number of stage-specific spots. Protein identification, through MS/MS analysis, resulted in the identification of proteins mainly related to oxidative metabolism and storage synthesis. These findings contribute to a better understanding of protein metabolism during seed development in recalcitrant seeds, besides providing information on established markers that could be useful in defining and improving somatic embryogenesis protocols, besides monitoring the development of somatic embryos in this species.

A systematic review of diapoma (teleostei: characiformes: characidae: stevardiinae: diapomini) with descriptions of two new species from southern Brazil

Diapoma is reviewed and four species are recognized: (1) Diapoma thauma, new species, from streams of the rio Jacuí basin, state of Rio Grande do Sul; (2) D. pyrrhopteryx, new species collected from the rio Canoas and streams flowing into this basin in the states of Rio Grande do Sul and Santa Catarina, Brazil; (3) Diapoma terofali, from streams flowing into rio Uruguay in Uruguay and Rio Grande do Sul, Brazil and streams flowing into rio de la Plata, Argentina; and (4) Diapoma speculiferum, from lowland coastal streams in Rio Grande do Sul, Brazil and Uruguay. Diapoma pyrrhopteryx possess the posteroventral opercular elongation typical of D. speculiferum, type species of the genus, but which is absent in D. thauma and D. terofali. Nonetheless, all the diapomin species have the caudal pouch organ about equally developed in both sexes and the dorsal portion of the pouch opening bordered by a series of 3 to 8 elongated scales, the two derived features that characterize the group. The two previously described species, D. speculiferum and D. terofali, are redescribed. Previous hypotheses of relationships among the diapomin genera Planaltina, Diapoma and Acrobrycon are discussed on the basis of preliminary morphological information. It is proposed that the Diapomini is a monophyletic group. An identification key, information on sexual dimorphism, gonad anatomy, reproductive mode and distribution of the species of Diapoma are provided.

Reproductive behavior, development and eye regression in the cave armored catfish, Ancistrus cryptophthalmus Reis, 1987 (Siluriformes: Loricariidae), breed in laboratory

The troglobitic armored catfish, Ancistrus cryptophthalmus (Loricariidae, Ancistrinae) is known from four caves in the São Domingos karst area, upper rio Tocantins basin, Central Brazil. These populations differ in general body shape and degree of reduction of eyes and of pigmentation. The small Passa Três population (around 1,000 individuals) presents the most reduced eyes, which are not externally visible in adults. A small group of Passa Três catfish, one male and three females, reproduced spontaneously thrice in laboratory, at the end of summertime in 2000, 2003 and 2004. Herein we describe the reproductive behavior during the 2003 event, as well as the early development of the 2003 and 2004 offsprings, with focus on body growth and ontogenetic regression of eyes. The parental care by the male, which includes defense of the rock shelter where the egg clutch is laid, cleaning and oxygenation of eggs, is typical of many loricariids. On the other hand, the slow development, including delayed eye degeneration, low body growth rates and high estimated longevity (15 years or more) are characteristic of precocial, or K-selected, life cycles. In the absence of comparable data for close epigean relatives (Ancistrus spp.), it is not possible to establish whether these features are an autapomorphic specialization of the troglobitic A. cryptophthalmus or a plesiomorphic trait already present in the epigean ancestor, possibly favoring the adoption of the life in the food-poor cave environment. We briefly discuss the current hypotheses on eye regression in troglobitic vertebrates.

Systematic review and cladistic analysis of the Hernandariinae (Opiliones: Gonyleptidae)

The harvestmen subfamily Hernandariinae is reviewed and a new classification is proposed based on cladistic analysis using 67 morphological characters. The subfamily is composed of six genera and 23 species and occurs in south-southeastern Brazil, Paraguay, and northeastern Argentina. Fourteen new combinations are proposed: Hernandaria armatifrons (Roewer, 1917); H. una (Mello-Leitão, 1927); Acrogonyleptes granulatus (H. Soares, 1966); A. pectinifemur (Soares & Soares, 1947); Acanthogonyleptes alticola (Mello-Leitão, 1922); A. editus (Roewer, 1943); A. fallax (Mello-Leitão, 1932); A. fulvigranulatus (Mello-Leitão, 1922); A. marmoratus (Mello-Leitão, 1940); A. pictus (Piza, 1942); A. singularis (Mello-Leitão, 1935); A. soaresi (Mello-Leitão, 1944); A. variolosus (Mello-Leitão, 1944). Seven synonymies are proposed: Proweyhia Mello-Leitão, 1927 and Metaxundarava Mello-Leitão, 1927 = Hernandaria Sørensen, 1884; Apembolephaenus calcaratus Soares & Soares, 1945 = H. armatifrons (Roewer, 1917); Sphaerobunus Rower, 1917 and Paraproweyhia Soares & Soares, 1947 = Acrogonyleptes Roewer, 1917; Paraproweyhia curitibae Soares & Soares, 1947 = Acrogonyleptes exochus (Mello-Leitão, 1931); and Melloleitaniana curitibae B. Soares, 1943 = Acrogonyleptes spinifrons Roewer, 1917. Three species are revalidated: Acrogonyleptes granulatus (H. Soares, 1966), A. pectinifemur (Soares & Soares, 1947), and A. spinifrons Roewer, 1917. Seven new species are described: Hernandaria sundermannorum sp. nov. (São Paulo State, Brazil), Hernandaria anitagaribaldiae sp. nov. (Santa Catarina State, Brazil), Hernandaria zumbii sp. nov. (Santa Catarina State, Brazil), Hernandaria chicomendesi sp. nov. (Santa Catarina State, Brazil), Acrogonyleptes cheguevarai sp. nov. (Rio Grande do Sul State, Brazil), Pseudotrogulus pagu sp. nov. (São Paulo State, Brazil), Pseudotrogulus trotskyi sp. nov. (Paraná State, Brazil).

Cation size effects-modified phase and PTCR development in Er3+ and Ca2+ co-doped BaTiO3 ceramics during sintering

Development of the positive temperature coefficient of resistivity (PTCR) in Er3+ and Ca2+ co-doped ferroelectric BaTiO3 was studied in this work, with Er3+ being used to act as a donor doping. Irrespective of all the materials showing high densities after sintering at 1200 to 1300 ºC, these revealed insulator at the lowest sintering temperature, changing to semiconducting and PTCR-type materials only when the sintering temperature was further increased. Observations from X-ray diffraction help correlating this effect with phase development in this formulated (Ba,Ca,Er)TiO3 system, considering the formation of initially two separated major (Ba,Ca)TiO3- and minor (Ca,Er)TiO3-based compounds, as a consequence of cation size-induced stress energy effects. Thus, appearance and enhancement here of the semiconducting and PTCR responses towards higher sintering temperatures particularly involve the incorporation of Er3+ into the major phase, rendering finally possible the generation and "percolative-like" migration of electrons throughout the whole material.

Aerobic and anaerobic metabolism for the zebrafish, Danio rerio, reared under normoxic and hypoxic conditions and exposed to acute hypoxia during development

In order to verify the influence of chronic and acute ambient oxygen levels from egg to adult stage of the zebrafish, in vivo oxygen consumption (MO2), critical tensions of oxygen (Pcrit), heart rate (fH) and total body lactate concentration (Lc) were determined for Danio rerio (Hamilton, 1822) raised at 28 °C under normoxic (7.5 mgO2.L-1 or 80 mm.Hg-1) and hypoxic conditions (4.3 mgO2.L-1) and exposed to acute hypoxia during different developmental stages. Our findings confirmed that very early stages do not respond effectively to ambient acute hypoxia. However, after the stage corresponding to the age of 30 days, D. rerio was able to respond to acute hypoxia through effective physiological mechanisms involving aerobic and anaerobic metabolism. Such responses were more efficient for the fishes reared under hypoxia which showed that D. rerio survival capability increased during acclimation to mild hypoxia. Measurements of body mass and length showed that moderate hypoxia did not affect growth significantly until the fish reached the stage of 60 days. Moreover, a growth delay was verified for the hypoxic-reared animals. Also, the D. rerio eggs-to-larvae survival varied from 87.7 to 62.4% in animals reared under normoxia and mild hypoxia, respectively. However, the surviving animals raised under moderated hypoxia showed a better aptitude to regulate aerobic and anaerobic capacities when exposed to acute hypoxia.

Development of instrumentation for amperometric and coulometric detection using ultramicroelectrodes

In this work it is presented the development of a simple, portable and inexpensive instrumentation for amperometric and coulometric detection in different analytical instrumentation systems utilizing ultramicroelectrodes. The software, developed in LabVIEW 7.1TM, is capable to carry out three main detection techniques (amperometric, pulsed amperometric and coulometric detection) and a voltammetric technique (cyclic voltammetry). The instrumentation was successfully evaluated using the following systems: cyclic voltammograms of metallic electrodes in alkaline solutions, flow electrochemical detection of glucose and glycine and direct determination of herbicide glyphosate (electrochemical detection coupled to HPLC).

High prevalence of drug-resistant tuberculosis and other mycobacteria among HIV-infected patients in Brazil: a systematic review

There is a little-noticed trend involving human immunodeficiency virus (HIV)-infected patients suspected of having tuberculosis: the triple-treatment regimen recommended in Brazil for years has been potentially ineffective in over 30% of the cases. This proportion may be attributable to drug resistance (to at least 1 drug) and/or to infection with non-tuberculous mycobacteria. This evidence was not disclosed in official statistics, but arose from a systematic review of a few regional studies in which the diagnosis was reliably confirmed by mycobacterial culture. This paper clarifies that there has long been ample evidence for the potential benefits of a four-drug regimen for co-infected patients in Brazil and it reinforces the need for determining the species and drug susceptibility in all positive cultures from HIV-positive patients.

Photodynamic antimicrobial chemotherapy (PACT) for the treatment of malaria, leishmaniasis and trypanosomiasis

A photodynamic effect occurs when photosensitiser molecules absorb light and dissipate the absorbed energy by transferring it to biological acceptors (usually oxygen), generating an excess of reactive species that are able to force cells into death pathways. Several tropical diseases present physiopathological aspects that are accessible to the application of a photosensitiser and local illumination. In addition, disease may be transmitted through infected blood donations, and many of the aetiological agents associated with tropical diseases have been shown to be susceptible to the photodynamic approach. However, there has been no systematic investigation of the application of photoantimicrobial agents in the various presentations, whether to human disease or to the disinfection of blood products or even as photo-insecticides. We aim in this review to report the advances in the photoantimicrobial approach that are beneficial to the field of anti-parasite therapy and also have the potential to facilitate the development of low-cost/high-efficiency protocols for underserved populations.

Development and validation of a simple and rapid capillary zone electrophoresis method for determination of nnrti nevirapine in pharmaceutical formulations

A simple and fast capillary zone electrophoresis (CZE) method has been developed and validated for quantification of a non-nucleoside reverse transcriptase inhibitor (NNRTI) nevirapine, in pharmaceuticals. The analysis was optimized using 10 mmol L-1 sodium phosphate buffer pH 2.5, +25 kV applied voltage, hydrodynamic injection 0.5 psi for 5 s and direct UV detection at 200 µm. Diazepam (50.0 µg mL-1) was used as internal standard. Under these conditions, nevirapine was analyzed in approximately less than 2.5 min. The analytical curve presented a coefficient of correlation of 0.9994. Limits of detection and quantification were 1.4 µg mL-1 and 4.3 µg mL-1, respectively. Intra- and inter-day precision expressed as relative standard deviations were 1.4% and 1.3%, respectively and the mean recovery was 100.81%. The active pharmaceutical ingredient was subjected to hydrolysis (acid, basic and neutral) and oxidative stress conditions. No interference of degradation products and tablet excipients were observed. This method showed to be rapid, simple, precise, accurate and economical for determination of nevirapine in pharmaceuticals and it is suitable for routine quality control analysis since CE offers benefits in terms of quicker method development and significantly reduced operating costs.

Development of a flow through photo-reactor to study degradation of organic compounds by Sequential Injection Analysis (SIA)

This work describes a photo-reactor to perform in line degradation of organic compounds by photo-Fenton reaction using Sequential Injection Analysis (SIA) system. A copper phthalocyanine-3,4',4²,4²¢-tetrasulfonic acid tetrasodium salt dye solution was used as a model compound for the phthalocyanine family, whose pigments have a large use in automotive coatings industry. Based on preliminary tests, 97% of color removal was obtained from a solution containing 20 µmol L-1 of this dye.