59 research outputs found

    Multiple poliovirus-induced organelles suggested by comparison of spatiotemporal dynamics of membranous structures and phosphoinositides

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    At the culmination of poliovirus (PV) multiplication, membranes are observed that contain phosphatidylinositol-4-phosphate (PI4P) and appear as vesicular clusters in cross section. Induction and remodeling of PI4P and membranes prior to or concurrent with genome replication has not been well studied. Here, we exploit two PV mutants, termed EG and GG, which exhibit aberrant proteolytic processing of the P3 precursor that substantially delays the onset of genome replication and/or impairs virus assembly, to illuminate the pathway of formation of PV-induced membranous structures. For WT PV, changes to the PI4P pool were observed as early as 30 min post-infection. PI4P remodeling occurred even in the presence of guanidine hydrochloride, a replication inhibitor, and was accompanied by formation of membrane tubules throughout the cytoplasm. Vesicular clusters appeared in the perinuclear region of the cell at 3 h post-infection, a time too slow for these structures to be responsible for genome replication. Delays in the onset of genome replication observed for EG and GG PVs were similar to the delays in virus-induced remodeling of PI4P pools, consistent with PI4P serving as a marker of the genome-replication organelle. GG PV was unable to convert virus-induced tubules into vesicular clusters, perhaps explaining the nearly 5-log reduction in infectious virus produced by this mutant. Our results are consistent with PV inducing temporally distinct membranous structures (organelles) for genome replication (tubules) and virus assembly (vesicular clusters). We suggest that the pace of formation, spatiotemporal dynamics, and the efficiency of the replication-to-assembly-organelle conversion may be set by both the rate of P3 polyprotein processing and the capacity for P3 processing to yield 3AB and/or 3CD proteins

    Diagnóstico de arritmias ventriculares en pacientes con síndrome post COVID-19

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    Objective. To identify ventricular arrhythmias in patients suffering from this disease (post VOCID-19 syndrome). Materials and methods. Descriptive, prospective and cross-sectional study. The sample corresponded to 79 patients infected by VOCID-19 diagnosed, treated and discharged from a Venezuelan institution. The most important study variables were: severity by VOCID-19 and types of ventricular arrhythmias. A data collection instrument validated by expert judgement was used. Rhythm Holter was used for cardiovascular evaluation. Descriptive statistics and graphs-figures were used. Results. 45.57% of the patients were female and 54.43% male, the average age was 56 years, with predomium of the age group between 41 and 60 years (49.4%). According to the symptomatology, 31.65% of the patients had a mild disease, 59.5% moderate and 8.86% severe. The most frequent types of arrhythmias according to the type of VOCID-19 suffered were: sinus rhythm (28%) in mild cases; sinus tachycardias (26%) and inappropriate (26%) for moderate cases and ventricular tachycardia (43%) in severe cases. As for the clinical evolution of the patient, in the process of mild disease the evolution was satisfactory of 100%; in the moderate the evolution was 88.5%, and in the severe 16.6%. Conclusion. Holter was able to determine the type of arrhythmia suffered by patients, which was different according to the degree of severity of the disease, so this information could be considered as a predictive factor.Objetivo. Identificar arritmias ventriculares en pacientes que padecieron esta enfermedad (síndrome post COVID-19). Materiales y métodos. Estudio descriptivo, prospectivo y transversal. La muestra correspondió a 79 pacientes infectados por COVID-19 diagnosticados, tratados y egresados de una institución venezolana. Las variables de estudio más importantes fueron: severidad por COVID-19 y tipos de arritmias ventricular. Se utilizó un instrumento de recolección de datos validado por juicio de expertos. Se empleó el Holter del ritmo para la evaluación cardiovascular. Se utilizo estadísticos descriptivos y gráficos-figuras. Resultados. El 45,57% de los pacientes fueron femeninos y 54,43% masculino, la edad promedio fue de 56 años, con predomio del grupo etario entre 41 y 60 años (49,4%). De acuerdo con la sintomatología, el 31,65% de los pacientes tuvo una enfermedad leve, el 59,5% moderada y un 8,86% severa. Los tipos de arritmias más frecuentes según el tipo de COVID-19 padecido, fueron: Ritmo Sinusal (28%) en casos leves; las Taquicardias Sinusal (26%) e Inapropiada (26%) para moderados y Taquicardia Ventricular (43%) en los casos severos. En cuanto a la evolución clínica del paciente, en el proceso de la enfermedad leve la evolución fue satisfactoria de un 100%; en la moderada la evolución tuvo un 88,5%, y en la severa de 16,6%. Conclusión. A través del Holter se pudo determinar el tipo de arritmia que padecían los pacientes, la cual fue diferente de acuerdo al grado de severidad de la enfermedad, por lo que esta información pudiera ser considerada como un factor predictivo

    Peri-conception and first trimester diet modifies reproductive development in bulls

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    Nutritional perturbation during gestation alters male reproductive development in rodents and sheep. In cattle both the developmental trajectory of the feto–placental unit and its response to dietary perturbations is dissimilar to that of these species. This study examined the effects of dietary protein perturbation during the peri-conception and first trimester periods upon reproductive development in bulls. Nulliparous heifers (n = 360) were individually fed a high- or low-protein diet (HPeri and LPeri) from 60 days before conception. From 24 until 98 days post conception, half of each treatment group changed to the alternative post-conception high- or low-protein diet (HPost and LPost) yielding four treatment groups in a 2 × 2 factorial design. A subset of male fetuses (n = 25) was excised at 98 days post conception and fetal testis development was assessed. Reproductive development of singleton male progeny (n = 40) was assessed until slaughter at 598 days of age, when adult testicular cytology was evaluated. Low peri-conception diet delayed reproductive development: sperm quality was lowered during pubertal development with a concomitant delay in reaching puberty. These effects were subsequent to lower FSH concentrations at 330 and 438 days of age. In the fetus, the low peri-conception diet increased the proportion of seminiferous tubules and decreased blood vessel area in the testis, whereas low first trimester diet increased blood vessel number in the adult testis. We conclude that maternal dietary protein perturbation during conception and early gestation may alter male testis development and delay puberty in bulls

    In Vitro and In Vivo High-Throughput Assays for the Testing of Anti-Trypanosoma cruzi Compounds

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    The treatment of Trypanosoma cruzi infection (the cause of human Chagas disease) remains a significant challenge. Only two drugs, both with substantial toxicity, are available and the efficacy of these dugs is often questioned – in many cases due to the limitations of the methods for assessing efficacy rather than to true lack of efficacy. For these reasons relatively few individuals infected with T. cruzi actually have their infections treated. In this study, we report on innovative methods that will facilitate the discovery of new compounds for the treatment of T. cruzi infection and Chagas disease. Utilizing fluorescent and bioluminescent parasite lines, we have developed in vitro tests that are reproducible and facile and can be scaled for high-throughput screening of large compound libraries. We also validate an in vivo screening test that monitors parasite replication at the site of infection and determines the effectiveness of drug treatment in less than two weeks. More importantly, results in this rapid in vivo test show strong correlations with those obtained in long-term (e.g. 40 day or more) treatment assays. The results of this study remove one of the obstacles for identification of effective and safe compounds to treat Chagas disease

    Combination of probenecid-sulphadoxine-pyrimethamine for intermittent preventive treatment in pregnancy

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    The antifolate sulphadoxine-pyrimethamine (SP) has been used in the intermittent prevention of malaria in pregnancy (IPTp). SP is an ideal choice for IPTp, however, as resistance of Plasmodium falciparum to SP increases, data are accumulating that SP may no longer provide benefit in areas of high-level resistance. Probenecid was initially used as an adjunctive therapy to increase the blood concentration of penicillin; it has since been used to augment concentrations of other drugs, including antifolates. The addition of probenecid has been shown to increase the treatment efficacy of SP against malaria, suggesting that the combination of probenecid plus SP may prolong the useful lifespan of SP as an effective agent for IPTp. Here, the literature on the pharmacokinetics, adverse reactions, interactions and available data on the use of these drugs in pregnancy is reviewed, and the possible utility of an SP-probenecid combination is discussed. This article concludes by calling for further research into this potentially useful combination

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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