Serum, gonadotrophins, growth factors, and steroid hormones stimulate the in vitro maturation (IVM) of competent oocytes, acting, directly or indirectly, upon the adenylate cyclase pathway to produce the intracellular messenger, cAMP. The intracellular levels of cAMP in cattle cumulus-oocyte complexes (COC) were manipulated by adding to the collection and maturation media invasive adenylate cyclase (iAC), a toxin produced by the bacterium, Bordetella pertussis. High concentrations of iAC (1 or 5 microgram/ml) in the maturation medium inhibited the resumption of meiosis, while low concentrations (0.1 or 0.01 microgram/ml) resulted in high rates of maturation to the MII stage (92.6 +/- 2.5 and 98.5 +/- 1.4% respectively). The same low concentrations of iAC in the maturation medium resulted in rates of development to the blastocyst stage 8 days post insemination (30.1 +/- 4.2 and 45.1 +/- 3.9%, respectively), which were either not different, or significantly better, than those obtained after IVM in medium supplemented only with serum and gonadotrophins (36.1 +/- 2.9%). Finally, the addition of 0.1 microgram/ml iAC and 0.5 mM 3-isobutyl 1-methylxanthine (IBMX) in the collection medium significantly improved the blastocyst rate when IVM was performed in control medium or medium supplemented with 0.01 microgram/ml iAC (31.9 +/- 5.5 vs. 12.1 +/- 1.6 and 45.5 +/- 2.9 vs. 19.1 +/- 2.3% respectively). It is concluded that the maintenance of an optimal intracellular concentration of cAMP before and during IVM ensures a high developmental competence of bovine oocytes matured in medium without serum and hormones. Mol. Reprod. Dev. 54:86-91,1999.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect a broad range of human tissues by using the host receptor angiotensin-converting enzyme 2 (ACE2). Individuals with comorbidities associated with severe COVID-19 display higher levels of ACE2 in the lungs compared to those without comorbidities, and conditions such as cell stress, elevated glucose levels and hypoxia may also increase the expression of ACE2. Here, we showed that patients with Barrett's esophagus (BE) have a higher expression of ACE2 in BE tissues compared to normal squamous esophagus, and that the lower pH associated with BE may drive this increase in expression. Human primary monocytes cultured in reduced pH displayed increased ACE2 expression and higher viral load upon SARS-CoV-2 infection. We also showed in two independent cohorts of 1,357 COVID-19 patients that previous use of proton pump inhibitors is associated with 2- to 3-fold higher risk of death compared to those not using the drugs. Our work suggests that pH has a great influence on SARS-CoV-2 Infection and COVID-19 severity.

The disease burden of yellow fever virus infection (YFV) is quite high in the tropics where vaccination coverage is low. To date, vaccination is the most effective control strategy to mitigate and eliminate the burden of YF disease. The licensed YF vaccines are safe and effective and serious adverse events are rare. Herein, we report three cases of neurological syndrome, compatible with meningoencephalitis following 17DD vaccination. In all cases, YFV-specific IgM antibodies were detected in the cerebrospinal fluid. Our observations confirm the development of YF vaccine-associated neurotropic disease, a rare serious adverse event, from which all three patients have fully recovered without any long-term sequelae. This report reinforces the need for awareness among health professionals to recognize and effectively manage such events in a timely manner.

Measles is a highly contagious acute febrile disease responsible for sporadic but explosive outbreaks worldwide. Although it was considered eliminated from the Americas, the disease reemerged in 2017. This reemergence was linked to reduced immunization rates. Vaccination, early identification of cases, and blocking of the transmission chain are the most effective tools to combat measles, for which there is not a specific antiviral treatment. In this Brazilian prospective cross-sectional study, we investigated the prevalence of measles antibodies in children, a population vulnerable to significant morbidity and mortality from exposure to infection. Between December 2018 to November 2019, blood samples from 252 children were collected and assessed for the presence of measles-specific IgG antibodies and an overall prevalence of 75.8% was observed. We further stratified the cohort into age subgroups, none of which exhibited antibody presence levels above the herd immunity threshold of 94%. Moreover, the calculated number of secondary cases resulting from a case in any age group ranged from 3 to 4, demonstrating that even with partial vaccination coverage this disease is still concerning and highly transmissible. Despite global warnings about measles and previous efforts to combat the advance of the disease, data on antibody prevalence and vaccination coverage in several countries are still concerning and indicate that significant parts of the population could be affected. Seroprevalence studies like this one are important to highlight actual epidemiological conditions and emphasize the need for additional strategies to encourage immunization and avoid the potential impacts of measles, particularly in children who can be severely affected.

O desenvolvimento de Tecnologias Interativas da Web (TIW), associado às caracterí­sticas da Geração Y e às extensas cargas horárias dos cursos das áreas da saúde, demonstra a necessidade de mudanças no processo de ensino-aprendizagem no ensino superior. A utilização dessas tecnologias para orientação de iniciação cientí­fica possibilita driblar os problemas de tempo e espaço impostos pelo modelo tradicional presencial. Visando verificar os benefí­cios das TIW no processo de comunicação e orientação às pesquisas acadêmicas, este estudo analisou a utilização dos softwares Mendeley, Facebook e FAMERP Virtual por grupo de discentes de iniciação cientí­fica dos cursos de Medicina e Enfermagem, da Faculdade de Medicina de São José do Rio Preto/SP. Foram levantadas referências bibliográficas relacionadas ao tema, além de análise dos registros dos softwares escolhidos no modelo computacional. Realizou-se uma análise quantitativa dos dados e calculou-se a efetividade do modelo proposto a partir do coeficiente de interatividade. Os dados encontrados corroboram os í­ndices do coeficiente de efetividade avaliados, identificando maior adesão ao software Facebook, grande utilidade na ferramenta Mendeley para armazenamento e compartilhamento de textos cientí­ficos e necessidades de reestruturação da proposta apresentada pela plataforma FAMERP Virtual. Verificou-se, ainda, a importância da atuação do docente como fomentador desse processo para integrar essas ferramentas na de orientação de iniciação cientí­fica, de modo a facilitar o contato e a troca de informação entre orientando e orientador. Sugere-se a continuidade das pesquisas e a necessidade de uma avaliação dos participantes dessa, para identificar as razões para maior efetividade de uma ferramenta perante as outras no processo de orientação, auxiliando na reformulação do modelo proposto, de modo a torná-lo mais efetivo e intuitivo, trazendo máximos benefí­cios ao orientador e seus orientandos.Palavras-chave: tecnologias interativas da web, rede social, saúde, iniciação cientí­fica.