Effects of metformin on behavioral alterations produced by chronic sucrose consumption in male rats.

Excessive consumption of sugary drinks negatively impacts the developing brain, producing long-lasting behavioral and metabolic disorders. Here, we study whether treatment with the antihyperglycemic agent metformin prevents some of the anxiety and memory alterations produced by chronic sucrose consumption. Male Sprague-Dawley rats had unrestricted access to water (control group) and a bottle containing a 10% sucrose solution (sucrose group, SUC) for 35 days. In parallel, a group of animals from SUC received metformin (25 mg/kg or 50 mg/kg, orally; MET 25 and MET 50 groups, respectively). After 2 weeks of metformin treatment, the animals weighed less than controls. SUC and MET 50 groups compensated for the caloric intake from the sugary solution by consuming less chow. In contrast, total energy intake in MET 25 was higher than the rest of the groups, but they still weighed less than control and SUC groups, suggesting that at this concentration, metformin delays body growth. The animals were then tested for the open field (OF), elevated plus maze (EPM) and novel object location (NOL) tests. In the OF, SUC animals spent more time in the central zone of the arena, evidenced by an increased number of entries and the distance traveled there. In the EPM, SUC animals spent more time in the open arms and less time in the central square. Metformin treatment prevented the decreased anxiety observed in SUC animals in the OF and EPM. In the NOL test, SUC animals showed less interest in novelty and metformin treatment did not improve this alteration. The preference for open spaces in the OF and EPM were associated with increased serum triglycerides (TG) and malondialdehyde levels in the medial prefrontal cortex (mPFC) and the hippocampus (HIP), while poor memory performance was associated with high basal blood glucose levels. In conclusion, the decreased anxiety-like behavior produced by chronic sucrose consumption was prevented by metformin treatment, through a mechanism that probably involves normalization of TG levels and decreased oxidative stress in mPFC and HIP.

Reconstructing the Last Common Ancestor: Epistemological and Empirical Challenges.

Reconstructing the genetic traits of the Last Common Ancestor (LCA) and the Tree of Life (TOL) are two examples of the reaches of contemporary molecular phylogenetics. Nevertheless, the whole enterprise has led to paradoxical results. The presence of Lateral Gene Transfer poses epistemic and empirical challenges to meet these goals; the discussion around this subject has been enriched by arguments from philosophers and historians of science. At the same time, a few but influential research groups have aimed to reconstruct the LCA with rich-in-detail hypotheses and high-resolution gene catalogs and metabolic traits. We argue that LGT poses insurmountable challenges for detailed and rich in details reconstructions and propose, instead, a middle-ground position with the reconstruction of a slim LCA based on traits under strong pressures of Negative Natural Selection, and for the need of consilience with evidence from organismal biology and geochemistry. We defend a cautionary perspective that goes beyond the statistical analysis of gene similarities and assumes the broader consequences of evolving empirical data and epistemic pluralism in the reconstruction of early life.

Importância e metodologias para mensuração dos esteroides sexuais em ruminantes / Importance and methodologies to measure sexual steroids progesterone and estradiol in ruminants

As dosagens dos esteroides sexuais, como progesterona e estradiol, pela sua importância, foram econtinuam sendo largamente utilizadas nas pesquisas em reprodução animal, nos estudos de fisiologia, patologiae biotecnologia reprodutiva. Vários métodos para quantificação desses esteroides foram desenvolvidos, porémcada metodologia analítica possui vantagens e limitações. O radioimunoensaio é o mais amplamente utilizado,pela sua eficiência e aplicabilidade em diversas espécies, mas tem como principal desvantagem o envolvimentode material radioativo. A preocupação nesse setor, aliada às exigências das legislações nacionais e internacionaisem questões ambientais, tem aumentado a necessidade do desenvolvimento de novas técnicas sem a utilização dematerial radioativo. Uma possibilidade que se apresenta é a tecnologia xMAP-Multiplex®. Esta tecnologiaapresenta vantagens sobre o radioimunoensaio, como ausência de radioatividade e detecção simultânea dehormônios, promovendo a diminuição do tempo gasto para dosagem e menor custo por amostra dosada. Porém,ainda sem estudos na endocrinologia reprodutiva de animais domésticos, torna-se necessária avaliá-la e validá-lapara cada espécie.

Quantifications of sexual steroids, such as progesterone and estradiol, because of their importance,have been widely used in many researches of animal´s reproduction to study reproductive physiology, pathologyand biotechnology. Several methods to quantify these steroids have been developed, but each analyticalmethodology has advantages and limitations. Radioimmunoassay is the most widely used method because of itsefficiency and applicability in several species, but it has as major disadvantage the use of radioactive material.These concerns added to the requirements of national and international´s legislations about environmentaltopics have increased the need to develop new techniques without the use of radioactive material. One newpossibility is the xMAP-Multiplex® technology. This technology offers advantages over radioimmunoassay, suchas absence of radioactivity and simultaneous detection of hormones, which decreases the time taken to quantifythem and lower price for each quantified sample. Although, there are no studies at reproductive endocrinologyat domestic animals and it is necessary to evaluate and validate it for each specie.

Importância e metodologias para mensuração dos esteroides sexuais em ruminantes / Importance and methodologies to measure sexual steroids progesterone and estradiol in ruminants

As dosagens dos esteroides sexuais, como progesterona e estradiol, pela sua importância, foram econtinuam sendo largamente utilizadas nas pesquisas em reprodução animal, nos estudos de fisiologia, patologiae biotecnologia reprodutiva. Vários métodos para quantificação desses esteroides foram desenvolvidos, porémcada metodologia analítica possui vantagens e limitações. O radioimunoensaio é o mais amplamente utilizado,pela sua eficiência e aplicabilidade em diversas espécies, mas tem como principal desvantagem o envolvimentode material radioativo. A preocupação nesse setor, aliada às exigências das legislações nacionais e internacionaisem questões ambientais, tem aumentado a necessidade do desenvolvimento de novas técnicas sem a utilização dematerial radioativo. Uma possibilidade que se apresenta é a tecnologia xMAP-Multiplex®. Esta tecnologiaapresenta vantagens sobre o radioimunoensaio, como ausência de radioatividade e detecção simultânea dehormônios, promovendo a diminuição do tempo gasto para dosagem e menor custo por amostra dosada. Porém,ainda sem estudos na endocrinologia reprodutiva de animais domésticos, torna-se necessária avaliá-la e validá-lapara cada espécie.(AU)

Quantifications of sexual steroids, such as progesterone and estradiol, because of their importance,have been widely used in many researches of animal´s reproduction to study reproductive physiology, pathologyand biotechnology. Several methods to quantify these steroids have been developed, but each analyticalmethodology has advantages and limitations. Radioimmunoassay is the most widely used method because of itsefficiency and applicability in several species, but it has as major disadvantage the use of radioactive material.These concerns added to the requirements of national and international´s legislations about environmentaltopics have increased the need to develop new techniques without the use of radioactive material. One newpossibility is the xMAP-Multiplex® technology. This technology offers advantages over radioimmunoassay, suchas absence of radioactivity and simultaneous detection of hormones, which decreases the time taken to quantifythem and lower price for each quantified sample. Although, there are no studies at reproductive endocrinologyat domestic animals and it is necessary to evaluate and validate it for each specie.(AU)

Innovative strategies for superovulation in cattle

Although superstimulatory protocols in cattle are usually initiated during mid-cycle, the elective control follicular wave emergence and ovulation have had a great impact on the application of on-farm embryo transfer. However, the most commonly used approach for the sinchronization of follicular wave emergence invoolves the use of estradiol which cannot be used in many parts of the world. Therefore, the need for alternative treatments has driven recent research. An approach that has shown promise is to initiate FSH treatments at the time of the emergence of the first follicular wave folliwing GnRH-induced ovulation. Alternatively, it has been shown that that it may be possible to ignore follicular wave status, and by extending the treatment protocol induce smaller follicles to grow and reach maturity and superovulate. Finally , the short half-life of pintuitary FSH necessitates twice daily treatments which are times consuming, stressful and subject to error. Recent treatment protocols have permitted supertimulation with a single or alternatively two-FSH treatments, reducing the need for animal handling during FSH treatments.

Innovative strategies for superovulation in cattle

Although superstimulatory protocols in cattle are usually initiated during mid-cycle, the elective control follicular wave emergence and ovulation have had a great impact on the application of on-farm embryo transfer. However, the most commonly used approach for the sinchronization of follicular wave emergence invoolves the use of estradiol which cannot be used in many parts of the world. Therefore, the need for alternative treatments has driven recent research. An approach that has shown promise is to initiate FSH treatments at the time of the emergence of the first follicular wave folliwing GnRH-induced ovulation. Alternatively, it has been shown that that it may be possible to ignore follicular wave status, and by extending the treatment protocol induce smaller follicles to grow and reach maturity and superovulate. Finally , the short half-life of pintuitary FSH necessitates twice daily treatments which are times consuming, stressful and subject to error. Recent treatment protocols have permitted supertimulation with a single or alternatively two-FSH treatments, reducing the need for animal handling during FSH treatments.(AU)