123 research outputs found
Cytoplasmic Compartmentalization of the Fetal piRNA Pathway in Mice
Derepression of transposable elements (TEs) in the course of epigenetic reprogramming of the mouse embryonic germline necessitates the existence of a robust defense that is comprised of PIWI/piRNA pathway and de novo DNA methylation machinery. To gain further insight into biogenesis and function of piRNAs, we studied the intracellular localization of piRNA pathway components and used the combination of genetic, molecular, and cell biological approaches to examine the performance of the piRNA pathway in germ cells of mice lacking Maelstrom (MAEL), an evolutionarily conserved protein implicated in transposon silencing in fruit flies and mice. Here we show that principal components of the fetal piRNA pathway, MILI and MIWI2 proteins, localize to two distinct types of germinal cytoplasmic granules and exhibit differential association with components of the mRNA degradation/translational repression machinery. The first type of granules, pi-bodies, contains the MILI-TDRD1 module of the piRNA pathway and is likely equivalent to the enigmatic “cementing material” first described in electron micrographs of rat gonocytes over 35 years ago. The second type of granules, piP-bodies, harbors the MIWI2-TDRD9-MAEL module of the piRNA pathway and signature components of P-bodies, GW182, DCP1a, DDX6/p54, and XRN1 proteins. piP-bodies are found predominantly in the proximity of pi-bodies and the two frequently share mouse VASA homolog (MVH) protein, an RNA helicase. In Mael-mutant gonocytes, MIWI2, TDRD9, and MVH are lost from piP-bodies, whereas no effects on pi-body composition are observed. Further analysis revealed that MAEL appears to specifically facilitate MIWI2-dependent aspects of the piRNA pathway including biogenesis of secondary piRNAs, de novo DNA methylation, and efficient downregulation of TEs. Cumulatively, our data reveal elaborate cytoplasmic compartmentalization of the fetal piRNA pathway that relies on MAEL function
Myeloid-Derived Suppressor Cells Show Different Frequencies in Diabetics and Subjects with Arterial Hypertension
Type 2 diabetes mellitus (DM2) is strongly associated with other comorbidities such as obesity, atherosclerosis, and hypertension.
Obesity is associated with sustained low-grade inflammatory response due to the production of proinflammatory cytokines. This inflammatory process promotes the differentiation of some myeloid cells, including myeloid-derived suppressor cells (MDSCs). In this study, two groups of individuals were included: DM2 patients and non-DM2 individuals with similar characteristics.
Immunolabeling of CD15+ CD14- and CD33+ HLA-DR-/low was performed from whole peripheral blood, and samples were analyzed by flow cytometry, and frequencies of MDSCs and the relationship of these with clinical variables, cytokine profile (measured by cytometric bead array), and anthropometric variables were analyzed. The frequency of CD33+ HLA-DR-/low MDSCs (that produce IL-10 and TGF-β, according to an intracellular detection) is higher in patients with DM2 (P < 0:05), and there is a positive correlation between the frequency of CD15+ CD14- and CD33+ HLA-DR-/low MDSC phenotypes. DM2 patients have an increased concentration of serum IL-5 (P < 0:05). Also, a negative correlation between the frequency of CD15+CD14- MDSCs and LDL cholesterol was found. Our group of DM2 patients have an increased frequency of mononuclear MDSC CD33+ HLA-DR-/low that produce TGF-β and IL-10. These cytokines have been associated with immune modulation and reduced T cell responses. DM2 and non-DM2 subjects show a similar cytokine profile, but the DM2 patients have anincreased concentration of IL-5
Nuclear Translocation of b-Catenin during Mesenchymal Stem Cells Differentiation into Hepatocytes Is Associated with a Tumoral Phenotype
Wnt/b-catenin pathway controls biochemical processes related to cell differentiation. In committed cells the alteration of
this pathway has been associated with tumors as hepatocellular carcinoma or hepatoblastoma. The present study evaluated
the role of Wnt/b-catenin activation during human mesenchymal stem cells differentiation into hepatocytes. The
differentiation to hepatocytes was achieved by the addition of two different conditioned media. In one of them, b-catenin
nuclear translocation, up-regulation of genes related to the Wnt/b-catenin pathway, such as Lrp5 and Fzd3, as well as the
oncogenes c-myc and p53 were observed. While in the other protocol there was a Wnt/b-catenin inactivation. Hepatocytes
with nuclear translocation of b-catenin also had abnormal cellular proliferation, and expressed membrane proteins involved
in hepatocellular carcinoma, metastatic behavior and cancer stem cells. Further, these cells had also increased auto-renewal
capability as shown in spheroids formation assay. Comparison of both differentiation protocols by 2D-DIGE proteomic
analysis revealed differential expression of 11 proteins with altered expression in hepatocellular carcinoma. Cathepsin B and
D, adenine phosphoribosyltransferase, triosephosphate isomerase, inorganic pyrophosphatase, peptidyl-prolyl cis-trans
isomerase A or lactate dehydrogenase b-chain were up-regulated only with the protocol associated with Wnt signaling
activation while other proteins involved in tumor suppression, such as transgelin or tropomyosin b-chain were downregulated
in this protocol. In conclusion, our results suggest that activation of the Wnt/b-catenin pathway during human
mesenchymal stem cells differentiation into hepatocytes is associated with a tumoral phenotyp
Seroprevalence of bovine viral diarrhea virus (BVDV) in cattle from Sotaquirá, Colombia
Worldwide distributed Bovine Viral Diarrhea Virus (BVDV) represents a high risk of infection in most bovine farms, in which it is associated with gastrointestinal, respiratory, and reproductive diseases. The purpose of this research was to establish the seroprevalence and the main risk factors associated with the presentation of BVDV in the municipality of Sotaquirá, Colombia. Samples were taken from 1000 cattle of Holstein, Ayrshire, Jersey, Normande Gyr and Holstein x Gyr. Epidemiological surveys were implemented, reproductive and management variables were taken into consideration. Indirect ELISA was performed to detect specific antibodies against BVDV using the commercial kit SERELISA® BVD p80 Ab Mono Blocking. The overall seroprevalence of antibodies against BVDV was 42.5% (425/1000), where the Gyr breed (59.1% apparent prevalence (AP); 60.3% real prevalence (PR)) and the age group > 4 years (53.0% PA; 54.4% PR) presented the highest seroprevalences. A significant statistical association was found for the breed, age, management practices evaluated and the presentation of PI3 (p ≤ 0.05). Age group > 4 years, Normande breed, presentation of PI3 and grazing lease were established as risk factors associated with BVDV in the herds. These infections are mainly associated with dairy cattle and herds with many animals, so it is important to consider vaccination plans as a preventive system and follow up on the most common diseases
Detección de Fasciola hepatica por medio de ELISA indirecto en ovinos y caprinos de Boavita, Colombia
The aim of this study was to determine the seroprevalence of Fasciola hepatica by indirect ELISA in sheep and goats from Boavita (Boyaca, Colombia). A descriptive cross-sectional study with simple random sampling was carried out. A total of 297 blood samples from sheep and 337 from goats of different breeds and age groups were collected. The sera were analyzed by the indirect ELISA technique with the commercial ELISA kit BIO K 211 - Monoscreen AbELISA F. hepatica. Additionally, an epidemiological survey was carried out. The seroprevalence of F. hepatica was 67.34% (200/297) in sheep and 59.94% (202/337) in goats. Likewise, seroprevalence was higher in males (sheep: 77.78%, 21/27; goats: 63.89%, 23/36), in sheep older than 3 years (83.33%, 50/60) and in goats less than 1 year of age. (69.77%, 60/86), as well as in Creole breed (sheep: 69.84%; goats: 61.79%). Sheep over 3 years of age were determined as a risk factor, while in goats the Creole breed variables and extensive grazing were identified as risk factors.El objetivo del estudio fue determinar la seroprevalencia de Fasciola hepatica por medio de ELISA indirecto en ovinos y caprinos de Boavita (Boyacá, Colombia). Se realizó un estudio descriptivo de corte transversal con muestreo aleatorio simple. Se colectaron 297 muestras de sangre de ovinos y 337 de caprinos de diferentes grupos raciales y etarios. Los sueros fueron analizados mediante la técnica ELISA indirecta con el kit comercial ELISA BIO K 211 - Monoscreen AbELISA F. hepatica. Adicionalmente se realizó una encuesta epidemiológica. La seroprevalencia de F. hepatica fue de 67.34% (200/297) en ovinos y de 59.94% (202/337) en caprinos. Asimismo, la seroprevalencia fue mayor en los machos (ovinos: 77.78%. 21/27; caprinos: 63.89%, 23/36), en ovinos mayores de 3 años (83.33%, 50/60) y en caprinos menores de 1 año (69.77%, 60/86), así como en los de raza criolla (ovinos: 69.84%; caprinos: 61.79%). Los ovinos mayores de 3 años se determinaron como factor de riesgo, en tanto que en los caprinos las variables raza criolla y el pastoreo extensivo se identificaron como factores de riesgo. El estudio demuestra una alta seropositividad de la enfermedad en la zona
Antimicrobial stewardship programs in adult intensive care units in Latin America: Implementation, assessments, and impact on outcomes
OBJECTIVE: To assess the impact of antimicrobial stewardship programs (ASPs) in adult medical-surgical intensive care units (MS-ICUs) in Latin America.
DESIGN: Quasi-experimental prospective with continuous time series.
SETTING: The study included 77 MS-ICUs in 9 Latin American countries.
PATIENTS: Adult patients admitted to an MS-ICU for at least 24 hours were included in the study.
METHODS: This multicenter study was conducted over 12 months. To evaluate the ASPs, representatives from all MS-ICUs performed a self-assessment survey (0-100 scale) at the beginning and end of the study. The impact of each ASP was evaluated monthly using the following measures: antimicrobial consumption, appropriateness of antimicrobial treatments, crude mortality, and multidrug-resistant microorganisms in healthcare-associated infections (MDRO-HAIs). Using final stewardship program quality self-assessment scores, MS-ICUs were stratified and compared among 3 groups: ≤25th percentile, \u3e25th to \u3c75th \u3epercentile, and ≥75th percentile.
RESULTS: In total, 77 MS-ICU from 9 Latin American countries completed the study. Twenty MS-ICUs reached at least the 75th percentile at the end of the study in comparison with the same number who remain within the 25th percentile (score, 76.1 ± 7.5 vs 28.0 ± 7.3; P \u3c .0001). Several indicators performed better in the MS-ICUs in the 75th versus 25th percentiles: antimicrobial consumption (143.4 vs 159.4 DDD per 100 patient days; P \u3c .0001), adherence to clinical guidelines (92.5% vs 59.3%; P \u3c .0001), validation of prescription by pharmacist (72.0% vs 58.0%; P \u3c .0001), crude mortality (15.9% vs 17.7%; P \u3c .0001), and MDRO-HAIs (9.45 vs 10.96 cases per 1,000 patient days; P = .004).
CONCLUSION: MS-ICUs with more comprehensive ASPs showed significant improvement in antimicrobial utilization
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BioTIME: A database of biodiversity time series for the Anthropocene.
MotivationThe BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables includedThe database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grainBioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2).Time period and grainBioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurementBioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format.csv and .SQL
Short-course combination treatment for experimental chronic Chagas disease
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, affects millions of people in the Americas and across the world, leading to considerable morbidity and mortality. Current treatment options, benznidazole (BNZ) and nifurtimox, offer limited efficacy and often lead to adverse side effects because of long treatment durations. Better treatment options are therefore urgently required. Here, we describe a pyrrolopyrimidine series, identified through phenotypic screening, that offers an opportunity to improve on current treatments. In vitro cell-based washout assays demonstrate that compounds in the series are incapable of killing all parasites; however, combining these pyrrolopyrimidines with a subefficacious dose of BNZ can clear all parasites in vitro after 5 days. These findings were replicated in a clinically predictive in vivo model of chronic Chagas disease, where 5 days of treatment with the combination was sufficient to prevent parasite relapse. Comprehensive mechanism of action studies, supported by ligand-structure modeling, show that compounds from this pyrrolopyrimidine series inhibit the Qi active site of T. cruzi cytochrome b, part of the cytochrome bc1 complex of the electron transport chain. Knowledge of the molecular target enabled a cascade of assays to be assembled to evaluate selectivity over the human cytochrome b homolog. As a result, a highly selective and efficacious lead compound was identified. The combination of our lead compound with BNZ rapidly clears T. cruzi parasites, both in vitro and in vivo, and shows great potential to overcome key issues associated with currently available treatments.</p
Short-course combination treatment for experimental chronic Chagas disease
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, affects millions of people in the Americas and across the world, leading to considerable morbidity and mortality. Current treatment options, benznidazole (BNZ) and nifurtimox, offer limited efficacy and often lead to adverse side effects because of long treatment durations. Better treatment options are therefore urgently required. Here, we describe a pyrrolopyrimidine series, identified through phenotypic screening, that offers an opportunity to improve on current treatments. In vitro cell-based washout assays demonstrate that compounds in the series are incapable of killing all parasites; however, combining these pyrrolopyrimidines with a subefficacious dose of BNZ can clear all parasites in vitro after 5 days. These findings were replicated in a clinically predictive in vivo model of chronic Chagas disease, where 5 days of treatment with the combination was sufficient to prevent parasite relapse. Comprehensive mechanism of action studies, supported by ligand-structure modeling, show that compounds from this pyrrolopyrimidine series inhibit the Qi active site of T. cruzi cytochrome b, part of the cytochrome bc1 complex of the electron transport chain. Knowledge of the molecular target enabled a cascade of assays to be assembled to evaluate selectivity over the human cytochrome b homolog. As a result, a highly selective and efficacious lead compound was identified. The combination of our lead compound with BNZ rapidly clears T. cruzi parasites, both in vitro and in vivo, and shows great potential to overcome key issues associated with currently available treatments.</p
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