Molecular epidemiology of Western equine encephalitis virus in Brazil, 2023-2024.

During the ongoing western equine encephalitis virus (WEEV) outbreak in South America, we described three fatal cases in horses from Rio Grande do Sul, Brazil. We sequenced WEEV strains and identified a novel lineage causing these cases. Continued surveillance and horse immunization are needed to mitigate the WEEV burden.

Effects of castration and of testosterone replacement on alpha(1)-adrenoceptor subtypes in the rat vas deferens.

The contractions of the rat vas deferens in response to noradrenaline are mediated through alpha(1A)-adrenoceptors. We observed participation of alpha(1B)-adrenoceptors in these contractions after castration. We now investigated the time course of this plasticity and the effects of testosterone by determining the actions of competitive antagonists on noradrenaline-induced contractions after 7, 14, 21 and 30 days of castration. BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7,9-dione dihydrochloride) antagonised noradrenaline-induced contractions in control and castrated rats with low pA(2) values (approximately = 6.8). In control vas deferens, WB 4101 (2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane hydrochloride) had a slope in the Schild plot no different from 1.0, while slopes lower than 1.0 (approximately 0.6) were observed for vas deferens from castrated rats. Chloroethylclonidine was ineffective in the control vas while it inhibited noradrenaline-induced contractions in vasa from castrated rats and converted the complex antagonism by WB 4101 into simple competitive antagonism. Treatment of castrated rats with testosterone prevented the effects of castration. The results suggest that alpha(1B)-adrenoceptors are detectable in vas deferens from at least the 7th through the 30th day after castration and that testosterone prevents this plasticity.

Functional characterisation of alpha(1)-adrenoceptors in denervated rat vas deferens.

We investigated whether or not surgical denervation of the rat vas deferens changes the alpha(1)-adrenoceptor subtypes involved in the contractions to noradrenaline. Denervated vas deferens was approximately 22 times more sensitive to noradrenaline (pD(2)=7.35+/-0.04) than control vas (pD(2)=6.01+/-0.03). This difference in noradrenaline potency was eliminated when cocaine (6 microM) was added to control vas (pD(2)=7.22+/-0.04). The noradrenaline-induced contractions of control and denervated vas deferens were insensitive to the alpha(1B)/alpha(1D)-adrenoceptor alkylating agent chloroethylclonidine (100 microM, 45 min). The concentration-response curves to noradrenaline in control and denervated vas deferens were competitively antagonised by prazosin (pA(2) approximately equal to 9.6), WB-4101 (pA(2) approximately equal to 9.5), 5-methyl urapidil (pA(2) approximately equal to 8.4), phentolamine (pA(2) approximately equal to 8.7), yohimbine (pA(2) approximately equal to 6.9), BMY 7378 (pA(2) approximately equal to 6.9) and indoramin (pA(2) approximately equal to 8.7). After the treatment of control and denervated vas deferens with phenoxybenzamine, the partial agonist oxymetazoline antagonised competitively the concentration-response curves to noradrenaline showing pA(2) values approximately 7.4 in both groups. We conclude that noradrenaline-induced contractions in control and denervated rat vas deferens are mediated by alpha(1A)-adrenoceptors and that surgical denervation of the rat vas deferens is not able to change the alpha(1)-adrenoceptor subtypes involved in the contractions to noradrenaline.

Effects of castration on alpha 1-adrenoceptor subtypes in the rat aorta.

The expression of alpha 1-adrenoceptor subtypes in several tissues is regulated by gonadal hormones. In this study, we investigated whether castration regulates the alpha 1-adrenoceptor subtypes mediating the contractions of the aorta from male rats to noradrenaline. Noradrenaline induced similar concentration-dependent contractions in the aorta from control and castrated rats. Treatment of the aorta from both control and castrated rats with the alpha 1B/alpha 1D-adrenoceptor alkylating agent chloroethylclonidine resulted in approximately 1600-fold rightward shift in the concentration-response curves to noradrenaline. The pA2 values found for WB 4101, benoxathian (alpha 1A-selective) and BMY 7378 (alpha 1D-selective) indicate that alpha 1D-adrenoceptors are involved in the contractions of the aorta from control and castrated rats to noradrenaline. However, there was a 15-fold difference between the pKB estimated through the lowest effective concentrations of the alpha 1A-adrenoceptor selective antagonist 5-methyl-urapidil in the aorta from control and castrated rats. The pKB estimated in aorta from control rats is consistent with the interaction with alpha 1D-adrenoceptors (7.58 +/- 0.06), while that calculated in organs from control rats is consistent with alpha 1A-adrenoceptors (8.76 +/- 0.09). These results suggest that castration induces plasticity in the alpha 1-adrenoceptor subtypes involved in the contractions of the aorta to noradrenaline.

Corpo humano e sexualidade na revista Ciência Hoje das Crianças (2001 a 2010) / Human body and sexuality in Ciência Hoje das Crianças magazine (2001 to 2010)

É de grande importância que o professor busque outros recursos educacionais além do livro didático para trabalhar os temas corpo humano e sexualidade nas aulas de Ciências. As revistas de divulgação científica poderiam ser usadas como fonte referencial. Neste trabalho, foi analisado como a revista Ciência Hoje das Crianças aborda o assunto e sua adequação como apoio didático­pedagógico. A amostragem consistiu de publicações de janeiro de 2001 a dezembro de 2010. Os temas corpo e sexualidade foram mencionados em 69% das revistas, mas apenas 15% fizeram referência à sexualidade. Esses temas ocuparam somente 7% do total de páginas. Dessa pequena parcela, 89% das páginas referiam­se ao corpo. Foram encontradas 133 referências: 113 sobre o corpo humano e 20 sobre sexualidade. Os resultados demonstraram uma abordagem limitada ao corpo biológico ao se tratar da fisiologia e anatomia do organismo e dos processos patológicos. Como os leitores da revista estão na fase de construção de conhecimentos e valores, a discussão sobre sexualidade contribuiria para atitudes mais conscientes e esclarecidas na adolescência.(AU)

It is very important that the teacher seeks other educational resources beyond the textbook to work the human body and sexuality issues in Science lessons. Scientific magazines could be used as a reference source. This study analyzed as Ciência Hoje das Crianças magazine discusses the subject and its suitability as didactic and pedagogical support. The sample consisted of publications from January 2001 to December 2010. Body and sexuality were mentioned by 69% of the magazines, but only 15% of the magazines referred to sexuality. These issues were only 7% of total pages, and, in this small part, 89% of pages were related to body. There were 133 references: 113 about human body and 20 about sexuality. The results showed a limited approach to the biological body, concerned to physiology and anatomy of the organism and pathologic processes. As its readers are building their knowledge and principles, the discussion about sexuality would contribute to more informed and enlightened attitudes in adolescence.(AU)