Modulation of membrane physical properties by natural insecticidal ketones.

The insecticidal activity of Mentha oil and its main components has been tested and established for various insects/pests. Several mint ketones have demonstrated to act on GABAA receptors (GABAA-R), a transmembrane channel target of several important insecticides whose activity can be modulated by surface-active compounds and by changes in the physical properties of the lipid membrane. In the present work, we analyze the capacity of monoterpenic ketones most commonly found in Mentha species, pulegone and menthone, to interact with DPPC membranes by molecular dynamics (MD) simulations and Langmuir monolayers. The experimental results indicate that the presence of menthone and pulegone in the subphase modify the interfacial characteristics of DPPC isotherms. The changes were reflected as expansion of the isotherms and disappearance or bringing forward of DPPC phase transition. MD simulation corroborate these results and indicate that both ketones are located at the region of the carbonyl group, at the interface with the acyl chains. Ketone intercalation between lipid molecules would induce an increasing intermolecular interaction, diminishing the film elasticity and causing an ordering effect. Our results suggest that the insecticidal activity of both ketones could involve their interaction with lipid molecules causing disturbance of the cell membrane as postulated for several larvicide compounds, or at least modulating the receptor surrounding.

Distribution of non-native suckermouth armoured catfish Pterygoplichthys ambrosettii in the upper Paraná River basin, Brazil.

This study describes the invasion of the upper Paraná River basin by Pterygoplichthys ambrosettii based on a literature review and field samples. Pterygoplichthys ambrosettii has been reported in 42 localities throughout the upper Paraná River basin, including the Tietê, Paranapanema, Paraná, Grande and Aguapeí rivers. The ascent of P. ambrosettii after the inundation of the Sete Quedas Falls on the Paraná River and the release of individuals by aquarium hobbyists were the primary drivers of this invasion.

First record of non-native hybrid catfish Pseudoplatystoma reticulatum × Leiarius marmoratus in the Upper Paraná River basin, Brazil.

The aim of this study is to report the presence of a three non-native hybrid long-whiskered catfishes (family Pimelodidae) in the Upper Paraná River basin, Brazil. Genetic analyses demonstrated that the three presumptive hybrids were a result of the crossbreeding of Pseudoplatystoma reticulatum (central Amazonas River basin and Lower Paraná River) and Leiarius marmoratus (Amazonas, Essequibo and Orinoco rivers), producing a hybrid commonly known in Brazil as cachandiá. The potential threat to biodiversity, due to possible genetic contamination, competition and predation of wild stocks, of such artificially produced hybrid fishes is discussed.

The SOS Chromotest applied for screening plant antigenotoxic agents against ultraviolet radiation.

In this work, we investigated the usefulness of the SOS Chromotest for screening plant antigenotoxic agents against ultraviolet radiation (UV). Fifty Colombian plant extracts obtained by supercritical fluid (CO2) extraction, twelve plant extract constituents (apigenin, carvacrol, ß-caryophyllene, 1,8-cineole, citral, p-cymene, geraniol, naringenin, pinocembrin, quercetin, squalene, and thymol) and five standard antioxidant and/or photoprotective agents (curcumin, epigallocatechin gallate, resveratrol, α-tocopherol, and Trolox®) were evaluated for their genotoxicity and antigenotoxicity against UV using the SOS Chromotest. None of the plant extracts, constituents or agents were genotoxic in the SOS Chromotest at tested concentrations. Based on the minimal extract concentration that significantly inhibited UV-genotoxicity (CIG), five plant extracts were antigenotoxic against UV as follows: Baccharis nítida (16 µg mL-1) = Solanum crotonifolium (16 µg mL-1) > Hyptis suaveolens (31 µg mL-1) = Persea caerulea (31 µg mL-1) > Lippia origanoides (62 µg mL-1). Based on CIG values, the flavonoid compounds showed the highest antigenotoxic potential as follows: apigenin (7 µM) > pinocembrin (15 µM) > quercetin (26 µM) > naringenin (38 µM) > epigallocatechin gallate (108 µM) > resveratrol (642 µM). UV-genotoxicity inhibition with epigallocatechin gallate, naringenin and resveratrol was related to its capability for inhibiting protein synthesis. A correlation analysis between compound antigenotoxicity estimates and antioxidant activity evaluated by the oxygen radical absorbance capacity (ORAC) assay showed that these activities were not related. The usefulness of the SOS Chromotest for bioprospecting of plant antigenotoxic agents against UV was discussed.

Evaluation of longevity modeling censored records in Nellore.

The aim of the present study was to evaluate the prediction ability of models that cope with longevity phenotypic expression as uncensored and censored in Nellore cattle. Longevity was defined as the difference between the dates of last weaned calf and cow birth. There were information of 77 353 females, being 61 097 cows with uncensored phenotypic information and 16 256 cows with censored records. These data were analyzed considering three different models: (1) Gaussian linear model (LM), in which only uncensored records were considered; and two models that consider both uncensored and censored records: (2) Censored Gaussian linear model (CLM); and (3) Weibull frailty hazard model (WM). For the model prediction ability comparisons, the data set was randomly divided into training and validation sets, containing 80% and 20% of the records, respectively. There were considered 10 repetitions applying the following restrictions: (a) at least three animals per contemporary group in the training set; and (b) sires with more than 10 progenies with uncensored records (352 sires) should have daughters in the training and validation sets. The variance components estimated using the whole data set in each model were used as true values in the prediction of breeding values of the animals in the training set. The WM model showed the best prediction ability, providing the lowest χ 2 average and the highest number of sets in which a model had the smallest value of χ 2 statistics. The CLM and LM models showed prediction abilities 2.6% and 3.7% less efficient than WM, respectively. In addition, the accuracies of sire breeding values for LM and CLM were lower than those obtained for WM. The percentages of bulls in common, considering only 10% of sires with the highest breeding values, were around 75% and 54%, respectively, between LM-CLM and LM-WM models, considering all sires, and 75% between LM-CLM and LM-WM, when only sires with more than 10 progenies with uncensored records were taken into account. These results are indicative of reranking of animals in terms of genetic merit between LM, CLM and WM. The model in which censored records of longevity were excluded from the analysis showed the lowest prediction ability. The WM provides the best predictive performance, therefore this model would be recommended to perform genetic evaluation of longevity in this population.

Estimates of genetic parameters for reproductive traits in Brahman cattle breed.

This study was designed to estimate genetic parameters for the following traits of Brahman cattle in Brazil: age at first calving (AFC), calving interval (CI), rebreeding (REB), and stayability (STAY). For REB, the value 1 was assigned to heifers that rebred and calved after first calving and the value 0 was assigned to heifers that failed to rebreed after first calving. Likewise, for STAY, the value 1 was assigned to cows that calved at least 3 times by the time they reach 6 yr of age; otherwise, the value 0 was assigned. A bivariate analysis was used to estimate covariances components by using linear animal model for CI and AFC and threshold animal model for REB and STAY. The mean h(2) were 0.10, 0.02, 0.22, and 0.10 for AFC, CI, REB, and STAY, respectively. The genetic correlations were ­0.13 between AFC and CI, ­0.35 between AFC and REB, ­0.57 between AFC and STAY, and 0.32 between REB and STAY, which reveal that cows that remain productive for longer periods in the herd also start breeding younger and present greater chances to REB. The selection of Brahman cattle for reproductive traits, such as AFC, CI, REB, and STAY, will render low magnitude and long-term responses.

Associations between single nucleotide polymorphisms and carcass traits in Nellore cattle using high-density panels.

The objective of this study was to evaluate associations between single nucleotide polymorphism (SNP) markers and carcass traits measured postmortem in Nellore cattle. Records of loin eye area (LEA) and backfat thickness (BF) from 740 males and records of hot carcass weight (HCW) from 726 males were analyzed. All of the animals were genotyped using the BovineHD BeadChip. Association analyses were performed by the restricted maximum likelihood method that considered one SNP at a time. Significant SNPs were identified on chromosomes 2 and 6 for LEA and on chromosomes 7, 1, and 2 for BF. For HCW, associations with SNPs were found on chromosomes 13, 14, and 28, in addition to genome regions that were directly related to this trait, such as the EFCAB8 and VSTM2L genes, and to bone development (RHOU). Some SNPs were located in very close proximity to genes involved in basal metabolism (BLCAP, NNAT, CTNNBL1, TGM2, and LOC100296770) and the immune system (BPI).

Prevalencia de ventilación mecánica en pacientes pediátricos con sepsis internados en Cuidados Intensivos / Prevalence of ventilation Mechanics in patients pediatric patients with sepsis interned in Intensive Care

Objetivo: Describir las características sociodemográficas y clínicas de niños con sepsis y ventilación mecánica. Métodos: Estudio observacional, transversal, multicéntrico, de un año de duración, en 19 Unidades de Cuidados Intensivos Pediátricos. Los datos se recolectaron a través de la página www.sepsisencolombia.com. Los pacientes fueron clasificados por diagnósticos, según tuvieran criterios de sepsis, sepsis grave, choque séptico y falla orgánica múltiple, y la necesidad o no de ventilación mecánica. Resultados: Se incluyeron 1051 pacientes con sepsis y el 67,7% de ellos requirió ventilación mecánica. El 43,1% eran niñas, la mediana de la edad era de 12 meses (rango intercuartílico 1-59). La mediana de estancia en la Unidad de Cuidados Intensivos Pediátricos de los pacientes ventilados fue de 8 días (rango intercuartílico 5-15) y de 4 días (rango intercuartílico 3-6) de los no ventilados. En el 97,1%, se conoció el origen de la sepsis, el más frecuente fue el aparato respiratorio. Se encontró relación entre tener sepsis y no requerir ventilación mecánica (rango intercuartílico 0,279-0,439) (p = 0,0000) y de requerirla, si había choque séptico (rango intercuartílico 0,694-0,781) (p = 0,0000). Los pacientes que requirieron ventilación mecánica tuvieron más probabilidad de morir (odds ratio 30,0; rango intercuartílico 11,5-78,6). Conclusiones: La sepsis y desarrollar choque séptico hacen más probable la necesidad de ventilación mecánica y hay una asociación entre ésta y mayor probabilidad de muerte.(AU)

Objective: To describe the sociodemographic and clinical characteristics of children with sepsis and mechanical ventilation. Methods: Observational, cross-sectional, multicenter study in 19 pediatric intensive care units. Data were collected through the website www. sepsisencolombia.com. Patients were classified by diagnosis, according to the following criteria: sepsis, severe sepsis, septic shock and multiple organ failure, with or without mechanical ventilation. Results: 1051 patients with sepsis were included and 67.7% of them required mechanical ventilation. 43.1% were female, median age: 12 months (interquartile range 1-59). The median stay in the PICU of ventilated patients was 8 days (interquartile range 5-15) and 4 days (interquartile range 3-6) of those without ventilation. The origin of sepsis was known in 97.1%, the most frequent source was the respiratory system. Relationship was found between having sepsis and not requiring mechanical ventilation (interquartile range 0.279 to 0.439) (p = 0.0000) and requiring it was found, if there was septic shock (interquartile range 0.694 to 0.781) (p = 0.0000). Patients who required mechanical ventilation were more likely to die (odds ratio 30.0; interquartile range 11.5 to 78.6. Conclusions: Sepsis and the development of septic shock make it more likely to need mechanical ventilation and there is an association between this and increased probability of death.(AU)

Importance of fasting in preparing dogs for abdominal ultrasound examination of specific organs.

OBJECTIVE: To describe the effect of fasting on the technical success of abdominal ultrasonography specifically in respect of examination of the gall bladder, duodenum, pancreas, adrenal glands and portal vein in dogs. METHODS: Randomised, prospective study of 150 dogs with a variety of physical characteristics. Animals were divided into two groups of 75 dogs each. Dogs in Group 1 were fasted for 8 to 12 hours before ultrasonographic evaluation and those in Group 2 were not but received food anytime between 10 minutes and 2 hours before the procedure. RESULTS: Intraluminal gas can influence the visibility of organs, but intraluminal gas accumulation occurred independently of fasting status. The assessment of abdominal organs was not affected by whether or not an animal was fasted. CLINICAL SIGNIFICANCE: Routine fasting of dogs before abdominal ultrasonography is not essential.

Seleção de características morfofuncionais de cavalos da raça Mangalarga Marchador por meio da análise de componentes principais / Identification of morphofunctional traits in Mangalarga Marchador horse using principal component analysis

Dados de 14.288 animais da raça Mangalarga Marchador, nascidos de 1990 a 2005, foram utilizados para avaliar a redução da dimensionalidade do espaço multivariado para características morfofuncionais, por meio da análise de componentes principais. Foram consideradas as características: altura na cernelha, altura na garupa, comprimento da cabeça, comprimento do pescoço, comprimento do dorso, comprimento da garupa, comprimento da espádua, comprimento do corpo, largura da cabeça, largura das ancas, perímetro do tórax, perímetro da canela e a pontuação da marcha. Para tais características, obtiveram-se sete componentes principais, a partir da matriz de correlação, que apresentaram variância inferior a 0,7 (autovalor inferior a 0,7). Isso sugere sete variáveis para descarte, por apresentarem maiores coeficientes de ponderação, em valor absoluto, a partir do último componente principal. A razão para isso é que variáveis altamente correlacionadas com os componentes de menor variância representam variação praticamente insignificante. Com base nesses resultados, recomendam-se as seguintes características para serem mantidas em trabalhos futuros com esta base de dados: pontuação da marcha, altura na garupa, comprimento do dorso, comprimento da garupa, largura da cabeça e perímetro da canela.

Records from 14,288 animals of the Mangalarga Marchador breed, born from 1990 to 2005, were used to discard morphofunctional traits in a principal component analysis. The following traits were used: height at withers, height at croup, lengths of head, neck, back, croup, hip length and body, widths of head, hip width, thorax perimeter, cannon bone circumference and gait score. For the traits considered it was observed that 7 principal components showed variation lower than 0.7; suggesting that seven variables could be discarded. The reason is that when variable are highly correlated with the principal components of smaller variance, their variation is practically insignificant. Based on those results the recommendation is to maintain the following traits for future research with this database: gait score, height at croup, length of back, length of croup, width of head and cannon bone circumference.

Seleção de características morfofuncionais de cavalos da raça Mangalarga Marchador por meio da análise de componentes principais / Identification of morphofunctional traits in Mangalarga Marchador horse using principal component analysis

Dados de 14.288 animais da raça Mangalarga Marchador, nascidos de 1990 a 2005, foram utilizados para avaliar a redução da dimensionalidade do espaço multivariado para características morfofuncionais, por meio da análise de componentes principais. Foram consideradas as características: altura na cernelha, altura na garupa, comprimento da cabeça, comprimento do pescoço, comprimento do dorso, comprimento da garupa, comprimento da espádua, comprimento do corpo, largura da cabeça, largura das ancas, perímetro do tórax, perímetro da canela e a pontuação da marcha. Para tais características, obtiveram-se sete componentes principais, a partir da matriz de correlação, que apresentaram variância inferior a 0,7 (autovalor inferior a 0,7). Isso sugere sete variáveis para descarte, por apresentarem maiores coeficientes de ponderação, em valor absoluto, a partir do último componente principal. A razão para isso é que variáveis altamente correlacionadas com os componentes de menor variância representam variação praticamente insignificante. Com base nesses resultados, recomendam-se as seguintes características para serem mantidas em trabalhos futuros com esta base de dados: pontuação da marcha, altura na garupa, comprimento do dorso, comprimento da garupa, largura da cabeça e perímetro da canela.(AU)

Records from 14,288 animals of the Mangalarga Marchador breed, born from 1990 to 2005, were used to discard morphofunctional traits in a principal component analysis. The following traits were used: height at withers, height at croup, lengths of head, neck, back, croup, hip length and body, widths of head, hip width, thorax perimeter, cannon bone circumference and gait score. For the traits considered it was observed that 7 principal components showed variation lower than 0.7; suggesting that seven variables could be discarded. The reason is that when variable are highly correlated with the principal components of smaller variance, their variation is practically insignificant. Based on those results the recommendation is to maintain the following traits for future research with this database: gait score, height at croup, length of back, length of croup, width of head and cannon bone circumference.(AU)

GABAergic pharmacological activity of propofol related compounds as possible enhancers of general anesthetics and interaction with membranes.

Phenol compounds, such as propofol and thymol, have been shown to act on the GABAA receptor through interaction with specific sites of this receptor. In addition, considering the high lipophilicity of phenols, it is possible that their pharmacological activity may also be the result of the interaction of phenol molecules with the surrounding lipid molecules, modulating the supramolecular organization of the receptor environment. Thus, in the present study, we study the pharmacological activity of some propofol- and thymol-related phenols on the native GABAA receptor using primary cultures of cortical neurons and investigate the effects of these compounds on the micro viscosity of artificial membranes by means of fluorescence anisotropy. The phenol compounds analyzed in this article are carvacrol, chlorothymol, and eugenol. All compounds were able to enhance the binding of [(3)H]flunitrazepam with EC50 values in the micromolar range and to increase the GABA-evoked Cl(-) influx in a concentration-dependent manner, both effects being inhibited by the competitive GABAA antagonist bicuculline. These results strongly suggest that the phenols studied are positive allosteric modulators of this receptor. Chlorothymol showed a bell-type effect, reducing its positive effect at concentrations >100 µM. The concentrations necessary to induce positive allosteric modulation of GABAA receptor were not cytotoxic. Although all compounds were able to decrease the micro viscosity of artificial membranes, chlorothymol displayed a larger effect which could explain its effects on [(3)H]flunitrazepam binding and on cell viability at high concentrations. Finally, it is suggested that these compounds may exert depressant activity on the central nervous system and potentiate the effects of general anesthetics.

Errors in abdominal ultrasonography in dogs and cats.

OBJECTIVES: To compare ultrasonographic diagnoses with the findings of surgical exploration to identify and classify potential diagnostic errors. METHODS: A cross-sectional prospective study of surgically confirmed ultrasound findings was conducted over a period of 29 months in two veterinary hospitals. Any errors in diagnosis made by the sonographer were classified as perceptual, cognitive, equipment-related, inevitable or multifactorial. RESULTS: One hundred and five ultrasound examinations were performed in 88 dogs and 17 cats. Errors in ultrasound diagnosis occurred in 17 animals (16·2%). These errors were identified as cognitive in 10 animals, inevitable in 5 and multifactorial in 2. CLINICAL SIGNIFICANCE: This study demonstrates that whilst errors of diagnosis do occur during ultrasonographic examination of the abdomen, understanding the causes of these errors will contribute to the development of this imaging modality.

Modelos lineares generalizados mistos na avaliação genética da prenhez precoce na raça Nelore / Generalized linear mixed models on genetic evaluation of early pregnancy in Nellore breed

Utilizaram-se os modelos lineares generalizados com as funções de ligação probit e logit na avaliação da prenhez precoce, e observaram-se os efeitos na variabilidade genética e na seleção de reprodutores quando diferentes idades são adotadas na definição dessa característica. A prenhez precoce foi estudada aos 15 (PP15) e 21 meses (PP21). Correlações entre os valores genéticos preditos e a porcentagem de touros em comum, considerando 10% dos touros com maiores valores genéticos (TOP10), entre a classificação dos modelos com função de ligação logit e probit e em cada modelo entre PP15 e PP21, foram calculadas. As herdabilidades para PP15 e PP21 foram próximas entre os modelos, exceto para PP15 utilizando a função de ligação probit. Aquelas entre os modelos e a TOP/10 foram altas. Os critérios de Akaike e Bayesiano apresentaram-se semelhantes entre os modelos. As correlações entre PP15 e PP21 e a TOP10, considerando o mesmo modelo, foram de média magnitude.

This study aimed to use the generalized linear models with probit and logit link function to evaluate early pregnancy, and to observe the effects on genetic variability and on sire selection when different ages are adopted in the definition of this trait. Early pregnancy was studied at 15 (EP15), and 21 (EP21) months. The analysis was done in R software. Pearson correlations (PC), between genetic predicted values and percentage of bulls in common considering only 10% of bulls with higher genetic values (TOP 10), between classification by logit and probit models and in each model among EP15 and EP21, were calculated. The heritability for EP15 and EP21 were close between models, except for EP15 using probit link function. PC and TOP10 among models were high. The Akaike and Bayesian criteria reported was similar between models. TOP10, considering the same model, among EP15-EP21 were moderated between EP15-EP21.

Modelos lineares generalizados mistos na avaliação genética da prenhez precoce na raça Nelore / Generalized linear mixed models on genetic evaluation of early pregnancy in Nellore breed

Utilizaram-se os modelos lineares generalizados com as funções de ligação probit e logit na avaliação da prenhez precoce, e observaram-se os efeitos na variabilidade genética e na seleção de reprodutores quando diferentes idades são adotadas na definição dessa característica. A prenhez precoce foi estudada aos 15 (PP15) e 21 meses (PP21). Correlações entre os valores genéticos preditos e a porcentagem de touros em comum, considerando 10% dos touros com maiores valores genéticos (TOP10), entre a classificação dos modelos com função de ligação logit e probit e em cada modelo entre PP15 e PP21, foram calculadas. As herdabilidades para PP15 e PP21 foram próximas entre os modelos, exceto para PP15 utilizando a função de ligação probit. Aquelas entre os modelos e a TOP/10 foram altas. Os critérios de Akaike e Bayesiano apresentaram-se semelhantes entre os modelos. As correlações entre PP15 e PP21 e a TOP10, considerando o mesmo modelo, foram de média magnitude.(AU)

This study aimed to use the generalized linear models with probit and logit link function to evaluate early pregnancy, and to observe the effects on genetic variability and on sire selection when different ages are adopted in the definition of this trait. Early pregnancy was studied at 15 (EP15), and 21 (EP21) months. The analysis was done in R software. Pearson correlations (PC), between genetic predicted values and percentage of bulls in common considering only 10% of bulls with higher genetic values (TOP 10), between classification by logit and probit models and in each model among EP15 and EP21, were calculated. The heritability for EP15 and EP21 were close between models, except for EP15 using probit link function. PC and TOP10 among models were high. The Akaike and Bayesian criteria reported was similar between models. TOP10, considering the same model, among EP15-EP21 were moderated between EP15-EP21.(AU)

Ultrasonography of small intestinal obstructions: a contemporary approach.

OBJECTIVES: To assess the accuracy of intestinal ultrasound for diagnosis of intestinal obstruction in dogs and cats. METHODS: A prospective clinical study was performed. Inclusion criteria were dogs and cats with clinical signs suggestive of gastrointestinal obstruction. Animals with no obstruction detected on ultrasound were excluded if they could not be monitored for 48 hours to confirm absence of obstruction. Sonographic diagnosis of small intestinal obstruction was based on identification of at least two findings suggestive of intestinal obstruction. RESULTS: Ninety-two patients suspected of having intestinal obstruction were included. Correct diagnosis of intestinal obstruction was made in 21 cases (23%), and in 68 (74%) this diagnosis was excluded. Interpretation of the images on prospective analysis had sensitivity, positive predictive, specificity and negative predictive values of 100%, 87.5%, 95.8% and 100%, respectively. CLINICAL SIGNIFICANCE: Ultrasonography is an excellent method for investigation of animals with gastrointestinal disorders, and is particularly useful for excluding obstructive processes.

Avaliação genética para peso corporal em um rebanho Nelore / Genetic evaluation for body weight in a Nellore herd

Estimaram-se as herdabilidades para os efeitos genéticos direto e materno e as correlações genéticas entre essas variáveis para os pesos ao desmame (P205), ao ano (P365) e ao sobreano (P550) em um rebanho Nelore do norte de Minas Gerais. O modelo estatístico incluiu os efeitos aditivos direto e materno, os efeitos fixos de grupo de contemporâneos (fazenda, sexo, regime alimentar, estação (seca e água) e ano de nascimento do animal) e o efeito da covariável idade da vaca ao parto (linear e quadrático). Os componentes de variância e os valores genéticos foram estimados utilizando-se o método REML. A tendência genética foi obtida utilizando-se a regressão do valor genético médio anual em relação ao ano de nascimento dos animais. As estimativas de herdabilidade do efeito aditivo direto (H2O) para P205, P365 e P550 foram 0,60, 0,69 e 0,75, respectivamente. Estes coeficientes de H2O são de alta magnitude, indicando que o rebanho apresenta variabilidade genética aditiva relativa e, portanto, espera-se progresso genético considerável utilizando a seleção. Pela análise da tendência genética, verificou-se que houve evolução nos valores genéticos dos animais ao longo dos anos estudados.(AU)

The heritabilities for direct and maternal genetic effects and genetic correlations between these effects were estimated for weight at 205 (P205), 365 (P365), and 550 days (P550) in a Nelore herd in northern Minas Gerais. The statistical model included direct and maternal additive effects, in addition to the fixed effects of contemporary group (farm, gender, diet, season - dry and water -, and year of birth) and the covariate age of cow at calving (linear and quadratic effects). The variance components and genetic values were estimated by REML method. The genetic trend was obtained using the regression of the annual mean genetic value in relation to the year birth. The heritability estimates for the direct additive effect (H2O) for P205, P365, and P550 were equal to 0.60, 0.69, and 0.75, respectively. These coefficients showed high magnitude, indicating that the herd in question presents a great additive genetic variability and therefore it is expected a great progress using genetic selection. By the analysis of genetic trend, it was verified a development in animals genetic values over the years studied.(AU)

Avaliação genética para peso corporal em um rebanho Nelore / Genetic evaluation for body weight in a Nellore herd

Estimaram-se as herdabilidades para os efeitos genéticos direto e materno e as correlações genéticas entre essas variáveis para os pesos ao desmame (P205), ao ano (P365) e ao sobreano (P550) em um rebanho Nelore do norte de Minas Gerais. O modelo estatístico incluiu os efeitos aditivos direto e materno, os efeitos fixos de grupo de contemporâneos (fazenda, sexo, regime alimentar, estação (seca e água) e ano de nascimento do animal) e o efeito da covariável idade da vaca ao parto (linear e quadrático). Os componentes de variância e os valores genéticos foram estimados utilizando-se o método REML. A tendência genética foi obtida utilizando-se a regressão do valor genético médio anual em relação ao ano de nascimento dos animais. As estimativas de herdabilidade do efeito aditivo direto () para P205, P365 e P550 foram 0,60, 0,69 e 0,75, respectivamente. Estes coeficientes de são de alta magnitude, indicando que o rebanho apresenta variabilidade genética aditiva relativa e, portanto, espera-se progresso genético considerável utilizando a seleção. Pela análise da tendência genética, verificou-se que houve evolução nos valores genéticos dos animais ao longo dos anos estudados.

The heritabilities for direct and maternal genetic effects and genetic correlations between these effects were estimated for weight at 205 (P205), 365 (P365), and 550 days (P550) in a Nelore herd in northern Minas Gerais. The statistical model included direct and maternal additive effects, in addition to the fixed effects of contemporary group (farm, gender, diet, season - dry and water -, and year of birth) and the covariate age of cow at calving (linear and quadratic effects). The variance components and genetic values were estimated by REML method. The genetic trend was obtained using the regression of the annual mean genetic value in relation to the year birth. The heritability estimates for the direct additive effect () for P205, P365, and P550 were equal to 0.60, 0.69, and 0.75, respectively. These coefficients showed high magnitude, indicating that the herd in question presents a great additive genetic variability and therefore it is expected a great progress using genetic selection. By the analysis of genetic trend, it was verified a development in animals genetic values over the years studied.

Flunitrazepam partitioning into natural membranes increases surface curvature and alters cellular morphology.

In recent studies, we showed that flunitrazepam (FNTZ) and other benzodiazepines interact with artificial phospholipid membranes locating at the polar head group region, inducing a membrane expansion, reducing the molecular packing and reorganising molecular dipoles. In the present paper we investigated the possibility that those phenomena could be transduced into changes in the curvature of membranes from natural origin. Hence we studied the effect of FNTZ on cellular morphology using human erythrocyte as a natural assay system. Shape changes of erythrocytes were evaluated by light microscopy and expressed as a morphological index (MI). FNTZ induced echinocytosis in a time-dependent manner with MI values significantly higher than those of control (without drug) or DMSO (vehicle) samples. Lidocaine, a local anesthetic known to induce stomatocytosis by incorporating in the inner monolayer, counterbalanced the concentration-dependent FNTZ crenating effects. FNTZ induced protective effects, compared with control and DMSO, against time-dependent hemolysis. Hypotonic-induced hemolysis, was also lowered by FNTZ in a concentration-dependent manner. Both antihemolytic effects suggested a drug-induced membrane expansion allowing a greater increase in cell volume before lysis. In such a complex system like a cell, curvature changes triggered by drug partitioning towards the plasma membrane, might be an indirect effect exerted through modifications of ionic-gradients or by affecting cytoskeleton-membrane linkage. In spite of that, the curvature changes can be interpreted as a mechanism suitable to relieve the tension generated initially by drug incorporation into the bilayer and may be the resultant of the dynamic interactions of many molecular fluxes leading to satisfy the spontaneous membrane curvature.