Mechanistic Insight into Bunyavirus-Induced Membrane Fusion from Structure-Function Analyses of the Hantavirus Envelope Glycoprotein Gc.

Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS) or of hantavirus pulmonary syndrome (HPS), depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic ß-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha- and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single "fusion loop". We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal "tail" that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens.

Aggregate culture of human embryonic stem cell-derived hepatocytes in suspension are an improved in vitro model for drug metabolism and toxicity testing.

Early phase drug development relies on primary human hepatocytes for studies of drug metabolism, cytotoxicity, and drug-drug interactions. However, primary human hepatocytes rapidly lose metabolic functions ex vivo and are refractory to expansion in culture and thus are limited in quantity. Hepatocytes derived from human pluripotent stem cells (either embryonic stem (ES) or induced pluripotent stem (iPS) cells), have the potential to overcome many of the limitations of primary human hepatocytes, but to date the use of human pluripotent stem cell-derived hepatocytes has been limited by poor enzyme inducibility and immature metabolic function. Here, we present a simple suspension culture of aggregates of ES cell-derived hepatocytes that compared to conventional monolayer adherent culture significantly increases induction of CYP 1A2 by omeprazole and 3A4 by rifampicin. Using liquid chromatography-tandem mass spectrometry, we further show that ES cell-derived hepatocytes in aggregate culture convert omeprazole and rifampicin to their human-specific metabolites. We also show that these cells convert acetaminophen (APAP) to its cytotoxic metabolite (N-acetyl-p-benzoquinone imine (NAPQI)), although they fail to perform APAP glucuronidation. In summary, we show that human pluripotent stem cell-derived hepatocytes in aggregate culture display improved enzymatic inducibility and metabolic function and is a promising step toward a simple, scalable system, but nonetheless will require further improvements to completely replace primary human hepatocytes in drug development.

Malignant fibrous histiocytoma of the head and neck: a case series.

PURPOSE: The study objective is to evaluate the clinical features and outcomes of patients treated for head and neck malignant fibrous histiocytoma at a tertiary care medical facility. MATERIALS AND METHODS: This is a retrospective case series of 17 adult subjects with malignant fibrous histiocytoma of the head and neck who were treated between January 1, 1965, and December 31, 2010. This study was conducted using patient charts at a tertiary medical center. Subject selection was conducted using Current Procedural Terminology numbers; International Classification of Diseases, Ninth Revision, codes; and a search of the tumor registry. RESULTS: Chart review of the 17 identified subjects revealed an overwhelming male predominance (88%) with an overall mean age of 69 years(52-87 years). Thirteen patients (78%) underwent some form of surgical resection, 6 patients (35%) received radiation therapy, and 6 (35%) were given chemotherapy over the course of treatment. Nine tumors (53%) had a cutaneous origin, whereas 8 lesions (47.1%) were found in the soft tissue of the head and neck region. The local recurrence rate following a single resection was 46%. Overall median survival following diagnosis was found to be 65 months, with a 5-year survival rate of 52%. Median disease-free survival was 20 months, with a 5-year disease-free survival rate of 37%. Overall median and 5-year survival rates were found to increase with clear surgical margins, as was 5-year survival. CONCLUSIONS: Aggressive surgical management to achieve clear margins is central to the effective treatment of malignant fibrous histiocytoma of the head and neck. Metastatic disease portends a dismal prognosis.

Brazilian university technology transfer to rural areas / Transferência de tecnologia de universidades brasileiras na área rural

In agriculture, there is a difference between average yield obtained by farmers and crop potential. There is technology available to increase yields, but not all farmers have access to it and/or use this information. This clearly characterizes an extension and technology transference problem. There are several technology transfer systems, but there is no system to fit all conditions. Therefore, it is necessary to create extension solutions according to local conditions. Another rural extension challenge is efficiency, despite continuous funding reductions. One proposal that has resulted from extension reform worldwide has suggested integration between the public and private sectors. The public universities could play the role of training and updating technical assistance of human resources, which is the one of the main aspects that has limited technology transfer. The objective of this study was to identify approaches to promote technology transfer generated in Brazilian public universities to rural areas through literature review. An experimental approach of technology transfer is presented here where a Brazilian university extension Vice-chancellor incorporates professionals from consolidated research groups according to demand. In this way, public universities take part of their social functions, by integrating teaching, research, and extension.

Em agricultura, há diferenças entre a produtividade média obtida pelos produtores e o potencial produtivo dos cultivos. Há informação tecnológica disponível para aumentar a produtividade, mas nem todos os produtores têm acesso e/ou usam a informação. Isso caracteriza claramente um problema de extensão e transferência de tecnologia. Há vários sistemas de transferência de tecnologia, mas, como não há sistema que se ajuste a todas as condições, é necessário criar alternativas adequadas às condições de cada local. Outro desafio da extensão rural é ser eficiente, apesar da contínua redução de recursos. Uma proposta advinda das constantes reformas na extensão verificada ao redor do mundo é o trabalho integrado entre a iniciativa privada e o poder público. A universidade pública contribuiria para o treinamento e a atualização dos recursos humanos envolvidos com assistência técnica, apontado como um dos aspectos limitantes na transferência de tecnologia. O objetivo deste estudo foi identificar, por meio de revisão bibliográfica, alternativas de promover a transferência de tecnologias geradas nas universidades públicas brasileiras para a área rural. Assim, é apresentada uma proposta de transferência de tecnologia a ser gerenciada pelas Pró-reitorias de extensão das universidades brasileiras, tendo como base os grupos consolidados de pesquisa, nos quais poderiam ser incorporados outros profissionais de acordo com a necessidade. Dessa forma, a universidade pública recuperaria parte da sua função social, integrando ensino, pesquisa e extensão.

Profundidade de localização do herbicida imazetapir + imazapique no solo sobre a fitotoxicidade em de plantas de arroz não resistente / Depth of placement of the herbicide imazethapyr + imazapic in soil profile on non-tolerant rice injury

Os herbicidas imazetapir e imazapique, usados em cultivares de arroz Clearfield®, possuem alta persistência e mobilidade no solo, ocasionando danos em genótipos de arroz não resistentes cultivados em rotação. Tais herbicidas podem lixiviar e atingir maiores profundidades ao longo do perfil. Esse posicionamento em profundidade pode ser um fator de seletividade e explicar parcialmente os diferentes resultados encontrados na literatura sobre o efeito residual do herbicida no solo. O objetivo do estudo foi avaliar o efeito da profundidade de localização no solo e da mistura formulada pelos herbicidas imazetapir e imazapique (75 e 25g e.a. L-1) na fitotoxicidade em genótipos de arroz não resistentes. Nesse sentido, foram conduzidos dois experimentos em solo com 15 por cento de argila e 1,2 por cento de matéria orgânica, em casa-de-vegetação, no campus da Universidade Federal de Pelotas (UFPel), em Pelotas, Rio Grande do Sul (RS). O experimento I consistiu de estudo preliminar visando a determinar a profundidade máxima de localização do herbicida no solo que causa danos ao arroz não resistente, e o herbicida foi alocado nas profundidades de 0, 5, 10, 20, 30, 50 e 70cm. O experimento II também consistiu na alocação do herbicida em profundidades ao longo do perfil do solo de 3, 6, 9, 12, 15 e 18cm. As variáveis analisadas foram fitotoxicidade, massa da matéria seca e estatura das plantas. O herbicida resultante da mistura formulada de imazetapir com imazapique localizado próximo à superfície do solo causa danos intensos em plantas de arroz não resistente, porém, quando alocado em profundidades maiores que 20cm da superfície do solo, não prejudica o desenvolvimento de genótipos de arroz não resistentes a essa mistura de herbicidas.

The herbicides imazethapyr and imazapic, used in Clearfield® rice, have high mobility and persistence in the soil, causing injury to non-resistant rice grown in rotation. These herbicides can leach and reach greater depths along the profile. This positioning can be a in-depth selectivity factor and partially explain the different results found in literature about carryover of imidazolines. To understand this effect, this study had the objective of to evaluate the effect of the positioning of the mixture of imazethapyr and imazapic (75g ai L-1 and 25g ai L-1) on the injury to non-resistant rice crop. Two experiments were carried out in soil with 15 percent clay and 1.2 percent organic matter in a greenhouse at the Universidade Federal de Pelotas, Pelotas, RS, Brazil. Experiment I consisted of a preliminary study to verify the location depth of the herbicide in the soil profile that causes injury to rice non-tolerant rice, and the herbicides has been allocated at depths of 0, 5, 10, 20, 30, 50 e 70cm. Experiment II also consisted in the allocation of herbicide at depths in the soil profile of 3, 6, 9, 12, 15 and 18cm. The variables were visual plant injury, plant shoot dry weight and plant height. The formulated mixture of imazethapyr + imazapic located near the soil surface cause injury to non resistant rice plants but when allocated at depths greater than 20cm of the soil surface does not affect the development of non-resistant rice.

Synthesis of 4-oxo-4,7-dihydrofuro[2,3-b]pyridine-5-carboxamides with broad-spectrum human herpesvirus polymerase inhibition.

A versatile synthesis of 4-oxo-4,7-dihydrofuro[2,3-b]pyridine-5-carboxylate esters has been developed which has lead to the identification of a new series of non-nucleoside inhibitors of human herpesvirus polymerases HCMV, HSV-1, EBV, and VZV with high specificity compared to human DNA polymerases.

2-Aryl-2-hydroxyethylamine substituted 4-oxo-4,7-dihydrothieno[2,3-b]pyridines as broad-spectrum inhibitors of human herpesvirus polymerases.

A novel series of 2-aryl-2-hydroxyethylamine substituted 4-oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carboxamides have been identified as potent antivirals against human herpesviruses. These compounds demonstrate broad-spectrum inhibition of the herpesvirus polymerases HCMV, HSV-1, EBV, and VZV with high specificity compared to human DNA polymerases.