Controlo químico de infestantes

Uma planta é considerada infestante quando nasce espontaneamente num local e momento indesejados, podendo interferir negativamente com a cultura instalada. As infestantes competem com as culturas para o espaço, a luz, água e nutrientes, podendo atrasar e prejudicar as operações de colheita, depreciar o produto final e assegurarem a reinfestação nas culturas seguintes. Dado o modo de propagação diferenciado das diversas espécies de infestantes, com as anuais a propagarem-se por semente e as perenes ou vivazes a assegurarem a sua propagação através de órgãos vegetativos (rizomas, bolbos, tubérculos, etc.), assim, também o seu controlo quer químico, quer mecânico terá que ser diferenciado, ou seja, para controlar infestantes anuais será suficiente destruir a sua parte aérea, enquanto para controlar infestantes perenes teremos que destruir os seus órgãos reprodutivos. O controlo de infestantes poderá ser químico, através da utilização de herbicidas, ou mecânico pela utilização de alfaias agrícolas, tais como a charrua de aivecas, a charrua de discos, a grade de discos, o escarificador e a fresa. Quando a técnica utilizada na instalação das culturas é a sementeira directa, o controlo das infestantes terá que ser obrigatoriamente químico, enquanto se o recurso à mobilização do solo for a técnica mais utilizada (sistema de mobilização tradicional ou sistema de mobilização reduzida), o controlo das infestantes tanto poderá ser químico como mecânico. Neste trabalho iremos abordar apenas, o controlo químico de infestantes

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Primary Immunodeficiency Diseases: Current and Emerging Therapeutics

Primary immunodeficiency diseases (PID) result from defects in genes affecting the immune and other systems in many and varied ways (1, 2). Until the last few years, treatments have been largely supportive, with the exception of bone marrow transplantation. However, recent advances in immunobiology, genetics, and the explosion of discovery and commercialization of biologic modifiers have drastically altered the landscape and opportunities in clinical immunology. Therapeutic options and life expectancy of PID patients have also improved dramatically, in large part as a result of better prevention and treatment of infections as well as better understanding and treatment of autoimmune complications (3). As early-life infection-related mortality declines we should anticipate the emergence of other conditions that were previously not appreciated, including malignancies and degenerative disorders unmasked by increasing longevity (4). The genomic revolution has identified literally hundreds of new genetic etiologies of immune dysfunction, many of which are or will soon be eligible for targeted therapies. These emerging immunomodulatory agents represent new therapeutic options in PIDs (5)

Risk Factors for Disseminated Coccidioidomycosis, United States

Of 150,000 new coccidioidomycosis infections that occur annually in the United States, ≈1% disseminate; one third of those cases are fatal. Immunocompromised hosts have higher rates of dissemination. We identified 8 patients with disseminated coccidioidomycosis who had defects in the interleukin-12/interferon-γ and STAT3 axes, indicating that these are critical host defense pathways

Complications of Tumor Necrosis Factor-± Blockade in Chronic Granulomatous Disease—Related Colitis

Background. Chronic granulomatous disease (CGD) is a genetic disorder of the phagocyte NADPH oxidase, which predisposes patients to infections and inflammatory complications, including severe colitis. Management of CGD colitis is a challenge because standard immunosuppressive therapy increases the risk of infection in already immunocompromised hosts

Increased Migratory and Activation Cell Markers of Peripheral Blood Lymphocytes in an Experimental Model of Nephrotic Syndrome

The present study aimed to evaluate the expression of CD80 and CD18 in subpopulations of peripheral blood leukocytes and oxidative kidney damage in rats with nephrotic syndrome (NS) induced by doxorubicin (Dox) in comparison to control animals at different time points. Male adult Wistar rats were submitted to 24-hour urine and blood collection for biochemical and immunological analysis at 7, 14, 21, and 28 days after Dox injection. After euthanasia, the kidneys were removed for histological analysis and the evaluation of oxidative stress. The phenotypic characterization of leukocytes was performed using flow cytometry. Dox-injected animals exhibited increased CD18 expression in cytotoxic T lymphocytes, NK cells, and monocytes and high CD80 expression in monocytes. Kidney oxidative damage was positively correlated with CD80 expression in monocytes and serum levels of creatinine. These results suggest that phagocytic and cytotoxic cells are preferentially recruited to the tissue injury site, which may contribute to kidney dysfunction in this animal model of NS. The blockade of integrin and costimulatory molecules may provide new therapeutic opportunities for NS