A

Abstract:  Non-Alcoholic Fatty Liver Disease (NAFLD) is considered a clinical manifestation of Metabolic Syndrome (MS). The hepatic lipid overload generates an excesive production of reactive oxygen species inducing oxidative stress (OS), there are still no standardized studies on effective treatments or consensus on the appropriate drug for each patient. Assess in MS the pharmacological response of atorvastatin and metformin on levels of inflammatory and OS biomarkers and possible liver modifications. 40 Male Wistar rats were used (8 per group): (A)Control, (B)MS, C) MS+Atorvastatin, D) MS+Metformin, E) MS+Atorvastatin+Metformin. MS was induced by 10% fructose for 6 week. The inflammatory and OS state were verify by Fibrinogen (mg/dL), Nitric oxide (NO)(µM) and superoxide dismutase (SOD)(U/mL) by means of spectrophotometry. The liver tissue was analyzed by optical microscopy(OM). ANOVA and hotelling as a post hoc test, p significance level<0.05. Fibrinogen concentration increased in (B)(288.83±6.8) with respect to (A)(203.33±6.8)(p<0.001), and in groups (C)(196±7.45), (D)(242±7.45) and (E)(104,33±6,8) showed significant regression of hyperfibrinogenemia (p<0.001). Levels of NO significantly decreased in (B)(14.76±1.86) compared to (A)(27.09±1.95)(p<0.001) and normalized their levels in the groups (C)(25.48±2.06), (D)(22.2±2,33) and (E)(31.25±2,18)(p<0,001). SOD activity in (B)(178.64±10.23) increased significantly contrasted with (A)(134.5±10.73)(p<0.001), (D)(195.71±12,82) and (E)(222,17±15.17)(p<0.001), however in group (C)(145.71±12.82) there was a significant decreased from (B)(p<0.001). In the hepatic OM (B), centrilobular and sinusoidal congestion with the presence of binucleated hepatocytes and vacuolization phenomena was evidenced. Our results indicated a pro-oxidative and inflammatory state with hepatic repercussion in (B). Atorvastatin normalizing biomarkers and retrograde the liver injury. Metformin achieves the reversal of inflammation and OS with restoration of liver tissue by showing the absence of cellular and inflammatory lesions. The pharmacological combination demonstrated superior efficacy than monotherapy, each drug acting on its biological targets, achieving greater effectiveness in normalizing biochemical variables and in regression of histological lesions. The current evidence on MS shows that in the face of a complex etiopathogenic mechanism, therapeutic approaches with multiple objectives are necessary such as the implementation of these drugs instead of waiting for an ideal drug that includes all the altered molecular pathways.Resumen:  Enfermedad del hígado graso asociada a disfunción metabólica(MAFLD, siglas inglés),es considerada una manifestación clínica del Síndrome Metabólico(SM). La sobrecarga hepática de lípidos genera producción excesiva de especies reactivas de oxígeno induciendo Estrés Oxidativo(EO), aún no hay estudios estandarizados sobre tratamientos efectivos ni consenso sobre el fármaco adecuado para cada paciente. Valorar en SM la respuesta farmacológica de atorvastatina y metformina sobre niveles de biomarcadores inflamatorios, de EO y las posibles modificaciones hepáticas. Utilizamos 40 ratas machos Wistar (n=8 por grupo): A)Control, B)SM, C)SM+Atorvastatina, D)SM+Metformina y E)SM+Atorvastatina+Metformina. SM inducido mediante fructuosa al 10% diluida en agua durante 6 semanas. Atorvastatina 0,035mg/día/rata y 1,78mg/día/rata de metformina durante 45 días. El estado inflamatorio y EO se constató por Fibrinógeno (mg/dL), óxido nítrico (NO)(µM) y superóxido dismutasa(SOD)(U/mL) por espectrofotometría. Se analizó histología hepática por microscopía óptica(MO). ANOVA y Hotelling como test post-hoc, significación p<0.05. Fibrinógeno aumentó en (B)(288,83±6,8) respecto a (A)(203,33±6,8)(p<0,001), los grupos (C)(196±7,45), (D)(242±7,45) y (E)(104,33±6,8) evidenciaron una regresión significativa de hiperfibrinogenemia(p<0,001). Los niveles de NO disminuyeron en (B)(14,76±1,86) comparado con (A)(27,09±1,95)(p<0,001), su concentración se normalizó en los grupos (C)(25,48±2,06), (D)(22,2±2,33) y (E)(31,25±2,18)(p<0,001). SOD aumentó en (B)(178,64±10,23), (D)(195,71±12,82) y  (E)(222,17±15,17)(p<0,001) contrastado con (A)(134,5±10,73)(p<0,001), sin embargo en (C)(145,71±12,82) evidenció disminución significativa respecto a (B)(p<0,001). MO hepática en (B) evidencio congestión centrolobulillar y leve congestión sinusoidales con presencia de hepatocitos binucleados y fenómenos de vacuolización. Los grupos (C), (D) y (E) demostraron regresión de las lesiones descriptas en (B).  Nuestros resultados indicaron un estado prooxidativo e inflamatorio con repercusión hepática en (B).Atorvastatina normalizando los biomarcadores analizados y retrogradando las lesiones hepáticas. Metformina logra una reversión de inflamación y EO, con restitución del tejido hepático al evidenciar ausencia de lesiones celulares e inflamatorias. La combinación farmacológica demostró eficacia superior que la monoterapia, actuando cada fármaco en sus blancos biológicos logrando una mayor efectividad en la normalización de las variables bioquímicas y en la regresión de lesiones histológicas. La evidencia actual sobre MAFLD demuestra que ante un mecanismo etiopatogénico complejo es necesario enfoques terapéuticos con múltiples objetivos, la implementación de estos fármacos en lugar de esperar un fármaco ideal que contemple todas las vías moleculares alteradas.

Effects of type and level of training on variation in physician knowledge in the use and acquisition of blood cultures: a cross sectional survey

BACKGROUND: Blood culture (BCX) use is often sub-optimal, and is a user-dependent diagnostic test. Little is known about physician training and BCX-related knowledge. We sought to assess variations in caregiver BCX-related knowledge, and their relation to medical training. METHODS: We developed and piloted a self-administered BCX-related knowledge survey instrument. Expert opinion, literature review, focus groups, and mini-pilots reduced > 100 questions in multiple formats to a final questionnaire with 15 scored content items and 4 covariate identifiers. This questionnaire was used in a cross-sectional survey of physicians, fellows, residents and medical students at a large urban public teaching hospital. The responses were stratified by years/level of training, type of specialty training, self-reported practical and theoretical BCX-related instruction. Summary scores were derived from participant responses compared to a 95% consensus opinion of infectious diseases specialists that matched an evidence based reference standard. RESULTS: There were 291 respondents (Attendings = 72, Post-Graduate Year (PGY) = 3 = 84, PGY2 = 42, PGY1 = 41, medical students = 52). Mean scores differed by training level (Attending = 85.0, PGY3 = 81.1, PGY2 = 78.4, PGY1 = 75.4, students = 67.7) [p ≤ 0.001], and training type (Infectious Diseases = 96.1, Medicine = 81.7, Emergency Medicine = 79.6, Surgery = 78.5, Family Practice = 76.5, Obstetrics-Gynecology = 74.4, Pediatrics = 74.0) [p ≤ 0.001]. Higher summary scores were associated with self-reported theoretical [p ≤ 0.001] and practical [p = 0.001] BCX-related training. Linear regression showed level and type of training accounted for most of the score variation. CONCLUSION: Higher mean scores were associated with advancing level of training and greater subject-related training. Notably, house staff and medical students, who are most likely to order and/or obtain BCXs, lack key BCX-related knowledge. Targeted education may improve utilization of this important diagnostic tool

Divergent Modulation of Neuronal Differentiation by Caspase-2 and -9

Human Ntera2/cl.D1 (NT2) cells treated with retinoic acid (RA) differentiate towards a well characterized neuronal phenotype sharing many features with human fetal neurons. In view of the emerging role of caspases in murine stem cell/neural precursor differentiation, caspases activity was evaluated during RA differentiation. Caspase-2, -3 and -9 activity was transiently and selectively increased in differentiating and non-apoptotic NT2-cells. SiRNA-mediated selective silencing of either caspase-2 (si-Casp2) or -9 (si-Casp9) was implemented in order to dissect the role of distinct caspases. The RA-induced expression of neuronal markers, i.e. neural cell adhesion molecule (NCAM), microtubule associated protein-2 (MAP2) and tyrosine hydroxylase (TH) mRNAs and proteins, was decreased in si-Casp9, but markedly increased in si-Casp2 cells. During RA-induced NT2 differentiation, the class III histone deacetylase Sirt1, a putative caspase substrate implicated in the regulation of the proneural bHLH MASH1 gene expression, was cleaved to a ∼100 kDa fragment. Sirt1 cleavage was markedly reduced in si-Casp9 cells, even though caspase-3 was normally activated, but was not affected (still cleaved) in si-Casp2 cells, despite a marked reduction of caspase-3 activity. The expression of MASH1 mRNA was higher and occurred earlier in si-Casp2 cells, while was reduced at early time points during differentiation in si-Casp9 cells. Thus, caspase-2 and -9 may perform opposite functions during RA-induced NT2 neuronal differentiation. While caspase-9 activation is relevant for proper neuronal differentiation, likely through the fine tuning of Sirt1 function, caspase-2 activation appears to hinder the RA-induced neuronal differentiation of NT2 cells

Mitigating effects of vaccination on influenza outbreaks given constraints in stockpile size and daily administration capacity

<p>Abstract</p> <p>Background</p> <p>Influenza viruses are a major cause of morbidity and mortality worldwide. Vaccination remains a powerful tool for preventing or mitigating influenza outbreaks. Yet, vaccine supplies and daily administration capacities are limited, even in developed countries. Understanding how such constraints can alter the mitigating effects of vaccination is a crucial part of influenza preparedness plans. Mathematical models provide tools for government and medical officials to assess the impact of different vaccination strategies and plan accordingly. However, many existing models of vaccination employ several questionable assumptions, including a rate of vaccination <it>proportional </it>to the population at each point in time.</p> <p>Methods</p> <p>We present a SIR-like model that explicitly takes into account vaccine supply and the <it>number </it>of vaccines administered per day and places data-informed limits on these parameters. We refer to this as the <it>non-proportional </it>model of vaccination and compare it to the proportional scheme typically found in the literature.</p> <p>Results</p> <p>The proportional and non-proportional models behave similarly for a few different vaccination scenarios. However, there are parameter regimes involving the vaccination campaign duration and daily supply limit for which the non-proportional model predicts smaller epidemics that peak later, but may last longer, than those of the proportional model. We also use the non-proportional model to predict the mitigating effects of variably timed vaccination campaigns for different levels of vaccination coverage, using specific constraints on daily administration capacity.</p> <p>Conclusions</p> <p>The non-proportional model of vaccination is a theoretical improvement that provides more accurate predictions of the mitigating effects of vaccination on influenza outbreaks than the proportional model. In addition, parameters such as vaccine supply and daily administration limit can be easily adjusted to simulate conditions in developed and developing nations with a wide variety of financial and medical resources. Finally, the model can be used by government and medical officials to create customized pandemic preparedness plans based on the supply and administration constraints of specific communities.</p

Differential Regional Immune Response in Chagas Disease

Following infection, lymphocytes expand exponentially and differentiate into effector cells to control infection and coordinate the multiple effector arms of the immune response. Soon after this expansion, the majority of antigen-specific lymphocytes die, thus keeping homeostasis, and a small pool of memory cells develops, providing long-term immunity to subsequent reinfection. The extent of infection and rate of pathogen clearance are thought to determine both the magnitude of cell expansion and the homeostatic contraction to a stable number of memory cells. This straight correlation between the kinetics of T cell response and the dynamics of lymphoid tissue cell numbers is a constant feature in acute infections yielded by pathogens that are cleared during the course of response. However, the regional dynamics of the immune response mounted against pathogens that are able to establish a persistent infection remain poorly understood. Herein we discuss the differential lymphocyte dynamics in distinct central and peripheral lymphoid organs following acute infection by Trypanosoma cruzi, the causative agent of Chagas disease. While the thymus and mesenteric lymph nodes undergo a severe atrophy with massive lymphocyte depletion, the spleen and subcutaneous lymph nodes expand due to T and B cell activation/proliferation. These events are regulated by cytokines, as well as parasite-derived moieties. In this regard, identifying the molecular mechanisms underlying regional lymphocyte dynamics secondary to T. cruzi infection may hopefully contribute to the design of novel immune intervention strategies to control pathology in this infection

Sensitivity of South American tropical forests to an extreme climate anomaly

The tropical forest carbon sink is known to be drought sensitive, but it is unclear which forests are the most vulnerable to extreme events. Forests with hotter and drier baseline conditions may be protected by prior adaptation, or more vulnerable because they operate closer to physiological limits. Here we report that forests in drier South American climates experienced the greatest impacts of the 2015–2016 El Niño, indicating greater vulnerability to extreme temperatures and drought. The long-term, ground-measured tree-by-tree responses of 123 forest plots across tropical South America show that the biomass carbon sink ceased during the event with carbon balance becoming indistinguishable from zero (−0.02 ± 0.37 Mg C ha−1 per year). However, intact tropical South American forests overall were no more sensitive to the extreme 2015–2016 El Niño than to previous less intense events, remaining a key defence against climate change as long as they are protected

A transcriptomal analysis of bovine oviductal epithelial cells collected during the follicular phase versus the luteal phase of the estrous cycle

BACKGROUND: Reproductive success depends on a functional oviduct for gamete storage, maturation, fertilization, and early embryonic development. The ovarian-derived steroids estrogen and progesterone are key regulators of oviductal function. The objective of this study was to investigate luteal and follicular phase-specific oviductal epithelial cell function by using microarray-based transcriptional profiling, to increase our understanding of mRNAs regulating epithelial cell processes, and to identify novel genes and biochemical pathways that may be found to affect fertility in the future. METHODS: Six normally cycling Angus heifers were assigned to either luteal phase (LP, n = 3) or follicular phase (FP, n = 3) treatment groups. Heifers in the LP group were killed between day 11 and 12 after estrus. Heifers in the FP group were treated with 25 mg PGF(2α) (Lutalyse, Pfizer, NY) at 8 pm on day 6 after estrus and killed 36 h later. Transcriptional profiling by microarray and confirmation of selected mRNAs by real-time RT-PCR analyses was performed using total RNA from epithelial cells isolated from sections of the ampulla and isthmus collected from LP and FP treatment groups. Differentially expressed genes were subjected to gene ontology classification and bioinformatic pathway analyses. RESULTS: Statistical one-way ANOVA using Benjamini-hochberg multiple testing correction for false discovery rate (FDR) and pairwise comparison of epithelial cells in the ampulla of FP versus LP groups revealed 972 and 597 transcripts up- and down-regulated, respectively (P < 0.05). Within epithelial cells of the isthmus in FP versus LP groups, 946 and 817 transcripts were up- and down-regulated, respectively (P < 0.05). Up-regulated genes from both ampulla and isthmus were found to be largely involved in cholesterol biosynthesis and cell cycle pathways, while down-regulated genes were found in numerous inflammatory response pathways. CONCLUSIONS: Microarray-based transcriptional profiling revealed phase of the cycle-dependent changes in the expression of mRNA within the epithelium of the oviducts’ ampulla and isthmus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12958-015-0077-1) contains supplementary material, which is available to authorized users