Brain-Derived Neurotrophic Factor Gene Val66Met Polymorphism Modulates Reversible Cerebral Vasoconstriction Syndromes

BACKGROUND: Reversible cerebral vasoconstriction syndrome (RCVS) could be complicated by cerebral ischemic events. Hypothetical mechanisms of RCVS involve endothelial dysfunction and sympathetic overactivity, both of which were reported to be related to brain-derived neurotrophic factor (BDNF). The study investigated the association between functional BDNF Val66Met polymorphism and RCVS. METHODS: Patients with RCVS and controls were prospectively recruited and genotyped for the BDNF Val66Met polymorphism. Magnetic resonance angiography (MRA) and transcranial color-coded Doppler sonography were employed to evaluate cerebral vasoconstriction. Genotyping results, clinical parameters, vasoconstriction scores, mean flow velocities of the middle cerebral artery (V(MCA)), and Lindegaard indices were analyzed. Split-sample approach was employed to internally validate the data. PRINCIPAL FINDINGS: Ninety Taiwanese patients with RCVS and 180 age- and gender-matched normal controls of the same ethnicity completed the study. The genotype frequencies did not differ between patients and controls. Compared to patients with Met/Met homozygosity, patients with Val allele had higher mean vasoconstriction scores of all arterial segments (1.60±0.72 vs. 0.87±0.39, p<0.001), V(MCA) values (116.7±36.2 vs. 82.7±17.9 cm/s, p<0.001), and LI (2.41±0.91 vs. 1.89±0.41, p = 0.001). None of the Met/Met homozygotes, but 38.9% of the Val carriers, had V(MCA) values of >120 cm/s (p<0.001). Split-sample validation by randomization, age, entry time or residence of patients demonstrated concordant findings. CONCLUSIONS: Our findings link BDNF Val66Met polymorphism with the severity of RCVS for the first time and implicate possible pathogenic mechanisms for vasoconstriction in RCVS

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Ecological strategies of tree species in the laurel forest of Tenerife (Canary Islands): an insight into cloud forest natural dynamics using long‑term monitoring data

In Tenerife (Canary Islands), the laurel forest is considered one of the most biodiverse ecosystems of the archipelago. This study aims at providing useful information about tree species strategies and their natural dynamics in order to improve understanding of the functioning of this ecosystem. The knowledge gained would be of great importance for laurel forest conservation, not only in the Canaries, but also in Madeira and the Azores. Our main research question is: ‘Are the ecological groups of laurel forest tree species, described in earlier studies based exclusively on regeneration strategies, consistent with species functional traits, growth patterns and spatial distributions?’ We used data from six 50 × 50 m permanent plots established in 1999 and re-measured in 2015, combined with information on twelve functional traits from newly produced data or extracted from previous studies. For each species, we analyzed the abundance of seedlings/suckers, saplings and adults inside the permanent plots. Two ordination methods were used to assess multivariate differences in functional traits between species. Different mixed-effect models were tested to investigate effects of sites, individual tree size and competition on tree growth rates. Finally we analyzed the spatial distribution of both saplings and adults and their interaction within the six permanent plots. Our results were consistent with a classification of species into different ecological groups based on (1) their shade tolerance: light-demanding versus shade-tolerant species and (2) their reproductive strategies: sexual (i.e., seedlings), asexual (i.e., suckers) or both. These differences between light-demanding versus shade-tolerant and/or seedling-producing species versus sucker-producing species were consistently observed across the species functional traits, growth patterns and spatial distributions. Only one species, Viburnum rigidum Vent., presented singularities compared with its previously established group. Because V. rigidum is mostly an understory species, we proposed to add a third aspect to the classification scheme: understory versus canopy species. This led to a total of six ecological groups within fourteen laurel forest tree species. Finally, this study also showed that the Tenerife laurel forest is still maturing and becoming richer in species, which outlines the importance of its preservation

Eficácia do halosulfuron no controle de tiririca (Cyperus rotundus) na cultura da cana-de-açúcar Efficacy of halosulphuron for the control of purple nutsedge in the sugar cane

A flora daninha infestante de um canavial é bastante específica e bem característica. O uso contínuo do mesmo herbicida é um dos fatores relacionados ao manejo, que mais tem contribuído para essa seleção. A tiririca (Cyperus rotundus) aparece como uma das principais espécies daninhas infestantes dos canaviais. O objetivo do presente trabalho foi avaliar a eficiência do controle químico da tiririca, através da utilização do herbicida halosulfuron, pertencente ao grupo químico das sulfoniluréias, na cultura da cana-de-açúcar. O experimento foi instalado na EPAMIG, em Prudente de Morais - MG, em 24 de março de 1994, com a variedade RB-72454, em solo de várzea Glei Pouco Úmido, textura argilo-siltosa com pH 5,8 e 2,9% de matéria orgânica. O delineamento experimental adotado foi o de blocos ao acaso com seis tratamentos e quatro repetições. Os herbicidas halosulfuron e 2,4-D (produto utilizado para comparação) foram aplicados em pós-emergência, em área total (cana-planta com altura média de 65cm), com pulverizador costal à pressão constante de 2,4kgf/cm2 ; munido de barra com dois bicos de jato plano (tipo "leque") 110.03, e vazão de 260 l/ha. No momento da aplicação a tiririca encontrava se no final da fase vegetativa e início do florescimento, com altura variando entre 15 e 30cm. O herbicida halosulfuron foi aplicado em mistura com o surfactante do grupo Tallow Amina, a 0,5% v/v. Foram realizadas avaliações de controle de plantas daninhas aos 15, 30, 60 e 90 dias após a aplicação dos herbicidas, baseando-se na contagem do número de manifestações epígeas vivas em 0,2m2 por parcela. Pelos resultados obtidos o halosulfuron, na dosagem de 131,25 g i.a./ha, mostrou-se altamente eficiente no controle pós-emergente da tiririca na cultura da cana-de-açúcar, proporcionando, aos 60 dias após a aplicação, um controle superior a 90%. Testes de viabilidade de tubérculos coletados 90 dias após a aplicação dos herbicidas, até a profundidade de 0,20m, mostraram que doses de 93,75; 112,5 e 131,25 g i.a./ha de halosulfuron chegaram a reduzir em respectivamente 47,7%, 52,7% e 60,7% o número de tubérculos viáveis. Esse resultado foi muito superior ao obtido com a aplicação do 2,4-D, que apresentou redução de apenas 23% no número de tubérculos viáveis. O produto mostrou-se totalmente seletivo à cultura, tendo sido aplicado em pós-emergência, na área total, não tendo sido observado qualquer sintoma de injúria caracterizado por necrose ou redução do crescimento das plantas.<br>The weed flora infesting sugar cane fields is specific and well characterized. The continuous use of the same hebicide is one of the crop managing factors which has mostly contributed to this weed selection. The purple nutsedge (Cyperus rotundus) is one of most important weed species infesting sugar cane fields. The objective of this studv was to evaluate the efficiency of the chemical control of purple nutsedge bv the herbicide halosulphuron, a sulphonylurea, ln the sugar cane crop. The experiment was set up at the EPAMIG Experimental Station, Prudente de Morais - MG, March 24, 1994, with the variety RB-72454, in a humic-glev silt-clay lowland soil, pH 5.8 and 2.9 organic matter. The experimental lavout was a randomized block design, with six tratments and five replications. The herbicides halosulphuron and 2,4-D (control) were applied as post-emergence, covering the whole area (sugar cane plants were 65cm tall), with a hand-held, 2,4kgf/cm2 constant pressure spraver, with two 110.03 flat spray tips, at the rate of 260 l/ha. During herbicide application, 15-30cm high purple nutsedges were terminating their vegetative growth and begining to flower. Halosulphuron was applied in a mixture wlth a Tallow Amine surfactant, 0.5% v/v. Weed control evaluation were done at 15, 30, 60 and 90 days after herbicide application, couting the number of live sproutings ln 0.2m2/plot . Results showed that halosulphuron, at the rate of 131,25 g i.a./ha gave better than 90% weed control 90 days after application. Viability tests performed in tubers collected 20cm deep, 90 days after herbicide application, showed that halosulphuron rates of 93,75; 112,5 and 131,25 g i.a./ha reduced viable tubers by 47,7%, 52,7% and 60,7% respectively. These results are significantlv better than those obtained with 2,4-D, which reduced viable tubers by only 23%. Halosulphuron appeared to be selective to sugar cane when applied in post-emergence covering the hole area, showing no injury svmptoms such as necrosis or stunted growth