802 research outputs found
Acute fasting before conception affects metabolic and endocrine status without impacting follicle and oocyte development and embryo gene expression in the rabbit.
Food deprivation affects female reproduction. The goal of the present study was to elucidate in the rabbit model the effects of acute energy restriction on ovarian function (follicle development, atresia rate and in vitro oocyte maturation) and embryonic development and gene expression of some candidate genes. Serum metabolic parameters (non-esterified fatty acids (NEFA), triglycerides, glucose, insulin and leptin concentrations) and endocrine markers (oestradiol-17β and progesterone concentrations) were also studied. A control group of nulliparous does fed ad libitum and a 72-h fasted group were used. At the end of the nutritional treatment, the ovaries of half of the animals were retrieved while the other animals were re-fed and artificially inseminated to recover embryos at 84 h after insemination, during the luteal phase. At the end of fasting, increased serum NEFA and decreased leptin concentrations were observed in the fasted group, but no differences appeared in serum steroid concentrations, follicle population and atresia rate or nuclear and cytoplasmic oocyte maturation. In the luteal phase, insulin concentrations increased notably in the fasted group. The number of recovered embryos per female and the speed of embryo development were reduced in the food-deprived group. Acute fasting altered both metabolic and endocrine markers and embryo development, but follicle and oocyte development and embryo gene expression were not affected
Localization of gravity on a de Sitter thick braneworld without scalar fields
In this work we present a simple thick braneworld model that is generated by
an intriguing interplay between a 5D cosmological constant with a de Sitter
metric induced in the 3-brane without the inclusion of scalar fields. We show
that 4D gravity is localized on this brane, provide analytic expressions for
the massive Kaluza-Klein (KK) fluctuation modes and also show that the spectrum
of metric excitations displays a mass gap. We finally present the corrections
to Newton's law due to these massive modes. This model has no naked
singularities along the fifth dimension despite the existence of a mass gap in
the graviton spectrum as it happens in thick branes with 4D Poincare symmetry,
providing a simple model with very good features: the curvature is completely
smooth along the fifth dimension, it localizes 4D gravity and the spectrum of
gravity fluctuations presents a mass gap, a fact that rules out the existence
of phenomenologically dangerous ultralight KK excitations in the model. We
finally present our solution as a limit of scalar thick branes.Comment: 11 pages in latex, no figures, title and abstract changed, a new
section and some references adde
Orientation of the Calcium Channel β Relative to the α12.2 Subunit Is Critical for Its Regulation of Channel Activity
BACKGROUND: The Ca(v)beta subunits of high voltage-activated Ca(2+) channels control the trafficking and biophysical properties of the alpha(1) subunit. The Ca(v)beta-alpha(1) interaction site has been mapped by crystallographic studies. Nevertheless, how this interaction leads to channel regulation has not been determined. One hypothesis is that betas regulate channel gating by modulating movements of IS6. A key requirement for this direct-coupling model is that the linker connecting IS6 to the alpha-interaction domain (AID) be a rigid structure. METHODOLOGY/PRINCIPAL FINDINGS: The present study tests this hypothesis by altering the flexibility and orientation of this region in alpha(1)2.2, then testing for Ca(v)beta regulation using whole cell patch clamp electrophysiology. Flexibility was induced by replacement of the middle six amino acids of the IS6-AID linker with glycine (PG6). This mutation abolished beta2a and beta3 subunits ability to shift the voltage dependence of activation and inactivation, and the ability of beta2a to produce non-inactivating currents. Orientation of Ca(v)beta with respect to alpha(1)2.2 was altered by deletion of 1, 2, or 3 amino acids from the IS6-AID linker (Bdel1, Bdel2, Bdel3, respectively). Again, the ability of Ca(v)beta subunits to regulate these biophysical properties were totally abolished in the Bdel1 and Bdel3 mutants. Functional regulation by Ca(v)beta subunits was rescued in the Bdel2 mutant, indicating that this part of the linker forms beta-sheet. The orientation of beta with respect to alpha was confirmed by the bimolecular fluorescence complementation assay. CONCLUSIONS/SIGNIFICANCE: These results show that the orientation of the Ca(v)beta subunit relative to the alpha(1)2.2 subunit is critical, and suggests additional points of contact between these subunits are required for Ca(v)beta to regulate channel activity
Investigación de lateralidad en recién nacidos prematuros
O estudo objetivou investigar a existência de coordenação mão-boca e preferência manual em recém-nascidos (RNs) prematuros a partir da estimulação gustativa, comparando a lateralidade dos bebês e seus genitores. Trata-se de estudo experimental e analÃtico, com procedimento duplo-cego. Participaram 90 RNs prematuros de uma maternidade pública de Sergipe. O teste durou 15 minutos, dividido em 3 perÃodos de 5 minutos. Nos primeiros 5 minutos, linha de base inicial - LB1, nenhum estÃmulo foi aplicado. No segundo momento, houve estimulação gustativa com sacarose para análise (PA) a 12% ou água, em 5 doses de 0,2 mL a cada minuto; e no último perÃodo, linha de base final - LB2, houve observação do recém-nascido sem aplicação de estÃmulo, durante 5 minutos. Foi realizado registro da frequência e duração dos comportamentos das mãos direita (MBD) e/ou esquerda (MBE) na região oral e sucção das mãos direita (SMD) e/ou esquerda (SME) dos RNs durante os estados comportamentais (sono profundo, sono leve, sonolento, alerta, agitado/irritado e choro) apresentados por estes. Os dados foram executados no software Statistical Package for the Social Sciences. Como resultado encontrou-se correlação forte de MBD e SMD na LB2, independente do estÃmulo recebido, evidenciando que a estimulação aumentou a correlação dos comportamentos do lado direito do corpo. Sugere-se realização de novas pesquisas sobre lateralidade, contemplando maior número de pais sinistros na amostra. _________________________________________________________________________________________ RESUMEN: El objetivo del estudio fue investigar la existencia de coordinación mano-boca y la preferencia manual en recién nacidos prematuros a partir de la estimulación gustativa, comparando la lateralidad de los bebes y sus progenitores. Se trata de un estudio experimental y analÃtico, con procedimiento doble ciego. Participaron 90 recién nacidos prematuros de una maternidad pública de Sergipe. El test duró 15 minutos, dividido en tres perÃodos de cinco minutos. En los primeros cinco minutos, lÃnea de base inicial - LB1, ningún estÃmulo fue aplicado. En un segundo momento, existió estimulación gustativa con sacarosa PA a 12% o agua, en cinco dosis de 0,2 mL a cada minuto, y en el último perÃodo, lÃnea de base final - LB2, existió observación del recién nacido sin aplicación de estÃmulo, durante cinco minutos. Fue realizado registro de la frecuencia y duración de los comportamientos en la mano derecha (MBD) y/o mano izquierda (MBI) en la región oral y succión de la mano derecha (SMD) y/o izquierda (SMI) de los recién nacidos durante los estados comportamentales (sueño profundo, sueño leve, somnoliento, alerta, agitado/irritado y llanto) presentados por estos. Los datos fueron analizados en el software Stastistical Package for the Social Sciences. Como resultado se encontró correlación fuerte de MBD y SMD en la LB2, independiente del estÃmulo recibido, evidenciando que la estimulación aumentó la correlación de los comportamientos del lado derecho del cuerpo. Se sugiere realización de nuevas investigaciones sobre lateralidad, contemplando mayor número de padres zurdos en la muestra
Genetic variability in five populations of Partamona helleri (Hymenoptera, Apidae) from Minas Gerais State, Brazil
Partamona is a Neotropical genus of stingless bees that comprises 33 species distributed from Mexico to southern Brazil. These bees are well-adapted to anthropic environments and build their nests in several substrates. In this study, 66 colonies of Partamona helleri from five localities in the Brazilian state of Minas Gerais (São Miguel do Anta, Teixeiras, Porto Firme, Viçosa and Rio Vermelho) were analyzed using nine microsatellite loci in order to assess their genetic variability. Low levels of observed (Ho = 0.099-0.137) and expected (H e = 0.128-0.145) heterozygosity were encountered and revealed discrete genetic differentiation among the populations (F ST = 0.025). AMOVA further showed that most of the total genetic variation (94.24%) in P. helleri was explained by the variability within local populations
Decolonisation of MRSA, S. aureus and E. coli by Cold-Atmospheric Plasma Using a Porcine Skin Model In Vitro
In the last twenty years new antibacterial agents approved by the U.S. FDA decreased whereas in parallel the resistance situation of multi-resistant bacteria increased. Thus, community and nosocomial acquired infections of resistant bacteria led to a decrease in the efficacy of standard therapy, prolonging treatment time and increasing healthcare costs. Therefore, the aim of this work was to demonstrate the applicability of cold atmospheric plasma for decolonisation of Gram-positive (Methicillin-resistant Staphylococcus aureus (MRSA), Methicillin-sensitive Staphylococcus aureus) and Gram-negative bacteria (E. coli) using an ex vivo pig skin model. Freshly excised skin samples were taken from six month old female pigs (breed: Pietrain). After application of pure bacteria on the surface of the explants these were treated with cold atmospheric plasma for up to 15 min. Two different plasma devices were evaluated. A decolonisation efficacy of 3 log10 steps was achieved already after 6 min of plasma treatment. Longer plasma treatment times achieved a killing rate of 5 log10 steps independently from the applied bacteria strains. Histological evaluations of untreated and treated skin areas upon cold atmospheric plasma treatment within 24 h showed no morphological changes as well as no significant degree of necrosis or apoptosis determined by the TUNEL-assay indicating that the porcine skin is still vital. This study demonstrates for the first time that cold atmospheric plasma is able to very efficiently kill bacteria applied to an intact skin surface using an ex vivo porcine skin model. The results emphasize the potential of cold atmospheric plasma as a new possible treatment option for decolonisation of human skin from bacteria in patients in the future without harming the surrounding tissue
Comparative Effectiveness of Guidelines for the Management of Hyperlipidemia and Hypertension for Type 2 Diabetes Patients
Background: Several guidelines to reduce cardiovascular risk in diabetes patients exist in North America, Europe, and Australia. Their ability to achieve this goal efficiently is unclear. Methods and Findings: Decision analysis was used to compare the efficiency and effectiveness of international contemporary guidelines for the management of hypertension and hyperlipidemia for patients aged 40-80 with type 2 diabetes. Measures of comparative effectiveness included the expected probability of a coronary or stroke event, incremental medication costs per event, and number-needed-to-treat (NNT) to prevent an event. All guidelines are equally effective, but they differ significantly in their medication costs. The range of NNT to prevent an event was small across guidelines (6.5-7.6 for males and 6.5-7.5 for females); a larger range of differences were observed for expected cost per event avoided (ranges, 157,186 for males and 163,775 for females). Australian and U.S. guidelines result in the highest and lowest expected costs, respectively. Conclusions: International guidelines based on the same evidence and seeking the same goal are similar in their effectiveness; however, there are large differences in expected medication costs. © 2011 Shah et al
Mannose-binding lectin-deficient genotypes as a risk factor of pneumococcal meningitis in infants
OBJECTIVES: The objective of this study was to evaluate to evaluate the role of mannose-binding-lectin deficient genotypes in pneumococcal meningitis (PM) in children. METHODS: We performed a 16-year retrospective study (January 2001 to March 2016) including patients ≤ 18 years with PM. Variables including attack rate of pneumococcal serotype (high or low invasive capacity) and MBL2 genotypes associated with low serum MBL levels were recorded. RESULTS: Forty-eight patients were included in the study. Median age was 18.5 months and 17/48 episodes (35.4%) occurred in children ≤ 12 months old. Serotypes with high-invasive disease potential were identified in 15/48 episodes (31.2%). MBL2 deficient genotypes accounted for 18.8% (9/48). Children ≤ 12 months old had a 7-fold risk (95% CI: 1.6-29.9; p 12 months old. A sub-analysis of patients by age group revealed significant proportions of carriers of MBL2 deficient genotypes among those ≤ 12 months old with PM caused by opportunistic serotypes (54.5%), admitted to the PICU (Pediatric Intensive Care Unit) (46.7%) and of White ethnicity (35.7%). These proportions were significantly higher than in older children (all p<0.05). CONCLUSIONS: Our results suggest that differences in MBL2 genotype in children ≤12 months old affects susceptibility to PM, and it may have an important role in the episodes caused by non-high invasive disease potential serotypes
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