1,362 research outputs found
Adaptive Dispersion Compensation for Remote Fiber Delivery of NIR Femtosecond Pulses
We report on remote delivery of 25 pJ broadband near-infrared femtosecond
light pulses from a Ti:sapphire laser through 150 meters of single-mode optical
fiber. Pulse distortion due to dispersion is overcome with pre-compensation
using adaptive pulse shaping techniques, while nonlinearities are mitigated
using an SF10 rod for the final stage of pulse compression. Near transform
limited pulse duration of 130 fs is measured after the final compression.Comment: 3 pages, 4 figure
Plasmodium falciparum Apicomplexan-Specific Glucosamine-6-Phosphate N-Acetyltransferase Is Key for Amino Sugar Metabolism and Asexual Blood Stage Development
UDP-N-acetylglucosamine (UDP-GlcNAc), the main product of the hexosamine biosynthetic pathway, is an important metabolite in protozoan parasites since its sugar moiety is incorporated into glycosylphosphatidylinositol (GPI) glycolipids and N- and O-linked glycans. Apicomplexan parasites have a hexosamine pathway comparable to other eukaryotic organisms, with the exception of the glucosamine-phosphate N-acetyltransferase (GNA1) enzymatic step that has an independent evolutionary origin and significant differences from nonapicomplexan GNA1s. By using conditional genetic engineering, we demonstrate the requirement of GNA1 for the generation of a pool of UDP-GlcNAc and for the development of intraerythrocytic asexual Plasmodium falciparum parasites. Furthermore, we present the 1.95 A resolution structure of the GNA1 ortholog from Cryptosporidium parvum, an apicomplexan parasite which is a leading cause of diarrhea in developing countries, as a surrogate for P. falciparum GNA1. The indepth analysis of the crystal shows the presence of specific residues relevant for GNA1 enzymatic activity that are further investigated by the creation of site-specific mutants. The experiments reveal distinct features in apicomplexan GNA1 enzymes that could be exploitable for the generation of selective inhibitors against these parasites, by targeting the hexosamine pathway. This work underscores the potential of apicomplexan GNA1 as a drug target against malaria. IMPORTANCE Apicomplexan parasites cause a major burden on global health and economy. The absence of treatments, the emergence of resistances against available therapies, and the parasite''s ability to manipulate host cells and evade immune systems highlight the urgent need to characterize new drug targets to treat infections caused by these parasites. We demonstrate that glucosamine-6-phosphate N-acetyltransferase (GNA1), required for the biosynthesis of UDP-N-acetylglucosamine (UDP-GlcNAc), is essential for P. falciparum asexual blood stage development and that the disruption of the gene encoding this enzyme quickly causes the death of the parasite within a life cycle. The high-resolution crystal structure of the GNA1 ortholog from the apicomplexan parasite C. parvum, used here as a surrogate, highlights significant differences from human GNA1. These divergences can be exploited for the design of specific inhibitors against the malaria parasite
Effect of OAS genes on SARS-CoV-2 infection and the induction of innate immune responses
Resumen del trabajo presentado en el 8th European Congress of Virology, celebrado en Gdańsk (Polonia), del 4 al 7 de mayo de 2023Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) infections cause different clinical symptoms ranging from
asymptomatic patients to patients suffering severe respiratory disease leading to death in some of them. Genetic and
functional studies have shown inborn-errors of interferon (IFN)-related genes in severe COVID-19 patients explaining
why some young patients devoid of co-morbidities succumbed to infection. In addition, very large genomic studies
identified common genetic variants affecting the expression and splicing of IFN-stimulated genes (ISGs) of the 2",5"-
oligoadenylate (2-5A) synthetase (OAS) family associated with COVID-19 severity. We have sequenced the whole
genome of 274 patients who required hospitalization after SARS-CoV-2 infection, finding ultrarare mutations in OAS1
and OAS3 genes. Upon double-stranded (ds)RNA binding, the OAS1, OAS2, and OAS3 proteins synthetize 2¿-
5¿olygoadenylates which activate the endonuclease RNAseL. This endonuclease degrades viral and cellular RNAs,
inhibiting viral replication. We have analyzed the effect of OAS1 and OAS3 genetic variants identified in our patients,
and found that some of them impair the RNAseL activation. In addition, by using OAS3 knock-out cells generated in
our laboratory and performing overexpression experiments, we have shown that OAS3 negatively modulates proinflammatory
responses induced by immune challenges, and that the activation of the RNAseL activity seems
necessary for this function. In addition, by using OAS3 knock-out mice infected with SARS-CoV-2 or treated with the
double-stranded RNA analog poly(I:C), we have shown that OAS3 deficiency leads to a higher mouse susceptibility to
SARS-CoV-2 infection and that OAS3 counteracts the induction of innate immune responses in the mouse infectedlungs,
leading to a higher inflammatory response in OAS3 knock-out mice, compared to the parental mice. Given the
contribution of exacerbated inflammatory responses to COVID-19 disease severity, our results suggest that
OAS1/OAS3 could play a role limiting the severity of the clinical symptoms after SARS-CoV-2 infection
Evidencias farmacológicas de la participación del sistema opioide endógeno en la respuesta inflamatoria local de la pata de la rata
Hemos investigado el papel del sistema opioide endógeno (SOE) en la respuesta inflamatoria inducida por la inyección subplantar (SP) de salino (SS) y carragenina (CA) en la pata trasera de la rata. Se usó naloxona intraperitoneal (IP) para desenmascarar los efectos de los opiáceos endógenos liberados durante la inflamación periférica. Tres grupos de ratas recibieron uno de los siguientes tratamientos SP: SS, CA o ninguna inyección (NI). En condiciones basales y 3 horas después del tratamiento fueron evaluados el umbral del dolor por presión (PPT), el volúmen de la pata (edema) y la temperatura local. En cada grupo fueron también investigados los efectos del vehículo IP, naloxona y (+)-naloxona (0,1 mg/kg). Los grupos SS y CA indujeron una significativa respuesta inflamatoria con hiperalgesia, edema e hiperemia local. La administración IP de naloxona pero no de (+)-naloxona, 15 minutos antes de la prueba, incrementó significativamente el edema en todos los grupos de tratamiento (p< 0,05) sin alterar el PPT o la temperatura local. El ANOVA de dos vías, reveló que el tratamiento y los fármacos, así como sus interacciones tenían un impacto significativo en el edema el cual estaba relacionado con los efectos de la CA y la naloxona. Nuestros hallazgos ilustran la implicación del sistema opioide endógeno a la respuesta fisiológica a la lesión local, regulando la fuga microvascular en los tejidos inflamados
Cost-effectiveness of exercise referral schemes enhanced by self-management strategies to battle sedentary behaviour in older adults: Protocol for an economic evaluation alongside the SITLESS three-armed pragmatic randomised controlled trial
Introduction: Promoting physical activity (PA) and reducing sedentary behaviour (SB) may exert beneficial effects on the older adult population, improving behavioural, functional, health and psychosocial outcomes in addition to reducing health, social care and personal costs. This paper describes the planned economic evaluation of SITLESS, a multicountry three-armed pragmatic randomised controlled trial (RCT) which aims to assess the short-term and long-term effectiveness and cost-effectiveness of a complex intervention on SB and PA in community-dwelling older adults, based on exercise referral schemes enhanced by a group intervention providing self-management strategies to encourage lifestyle change.
Methods and analysis: A within-trial economic evaluation and long-term model from both a National Health Service/personal social services perspective and a broader societal perspective will be undertaken alongside the SITLESS multinational RCT. Healthcare costs (hospitalisations, accident and emergency visits, appointment with health professionals) and social care costs (eg, community care) will be included in the economic evaluation. For the cost-utility analysis, quality-adjusted life-years will be measured using the EQ-5D-5L and capability well-being measured using the ICEpop CAPability measure for Older people (ICECAP-O) questionnaire. Other effectiveness outcomes (health related, behavioural, functional) will be incorporated into a cost-effectiveness analysis and cost-consequence analysis.
The multinational nature of this RCT implies a hierarchical structure of the data and unobserved heterogeneity between clusters that needs to be adequately modelled with appropriate statistical and econometric techniques. In addition, a long-term population health economic model will be developed and will synthesise and extrapolate within-trial data with additional data extracted from the literature linking PA and SB outcomes with longer term health states.
Methods guidance for population health economic evaluation will be adopted including the use of a long-time horizon, 1.5% discount rate for costs and benefits, cost consequence analysis framework and a multisector perspective.
Ethics and dissemination: The study design was approved by the ethics and research committee of each intervention site: the Ethics and Research Committee of Ramon Llull University (reference number: 1314001P) (Fundació Blanquerna, Spain), the Regional Committees on Health Research Ethics for Southern Denmark (reference number: S-20150186) (University of Southern Denmark, Denmark), Office for Research Ethics Committees in Northern Ireland (ORECNI reference number: 16/NI/0185) (Queen’s University of Belfast) and the Ethical Review Board of Ulm University (reference number: 354/15) (Ulm, Germany). Participation is voluntary and all participants will be asked to sign informed consent before the start of the study.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 634 270. This article reflects only the authors' view and the Commission is not responsible for any use that may be made of the information it contains.
The findings of the study will be disseminated to different target groups (academia, policymakers, end users) through different means following the national ethical guidelines and the dissemination regulation of the Horizon 2020 funding agency.
Use of the EuroQol was registered with the EuroQol Group in 2016.
Use of the ICECAP-O was registered with the University of Birmingham in March 2017.
Trial registration number: NCT02629666; Pre-results
Simultaneous Treatment with Statins and Aspirin Reduces the Risk of Prostate Cancer Detection and Tumorigenic Properties in Prostate Cancer Cell Lines
Nowadays prostate cancer is the most common solid tumor in men from industrialized countries and the second leading cause of death. At the ages when PCa is usually diagnosed, mortality related to cardiovascular morbidity is high; therefore, men at risk for PCa frequently receive chronic lipid-lowering and antiplatelet treatment. The aim of this study was to analyze how chronic treatment with statins, aspirin, and their combination influenced the risk of PCa detection. The tumorigenic properties of these treatments were evaluated by proliferation, colony formation, invasion, and migration assays using different PCa cell lines, in order to assess how these treatments act at molecular level. The results showed that a combination of statins and aspirin enhances the effect of individual treatments and seems to reduce the risk of PCa detection (OR: 0.616 (95% CI: 0.467-0.812), P < 0.001). However, if treatments are maintained, aspirin (OR: 1.835 (95% CI: 1.068-3.155), P = 0.028) or the combination of both drugs (OR: 3.059 (95% CI: 1.894-4.939), P < 0.001) represents an increased risk of HGPCa. As observed at clinical level, these beneficial effects in vitro are enhanced when both treatments are administered simultaneously, suggesting that chronic, concomitant treatment with statins and aspirin has a protective effect on PCa incidence
A record-linkage study of the development of hepatocellular carcinoma in persons with hepatitis C infection in Scotland
We investigated trends in first time hospital admissions and deaths attributable to hepatocellular carcinoma (HCC) in a large population based cohort of 22 073 individuals diagnosed with hepatitis C viral (HCV) infection through laboratory testing in Scotland in 1991 2006. We identified new cases of HCC through record linkage to the national inpatient hospital discharge database and deaths registry. A total of 172 persons diagnosed with HCV were admitted to hospital or died with first time mention of HCC. Hepatocellular carcinoma incidence increased between 1996 and 2006 (average annual change of 6.1, 95% confidence interval (CI):0.9 11.6%, P¼0.021). The adjusted relative risk of HCC was greater for males (hazard ratio¼2.7, 95% CI: 1.7 4.2), for those aged 60 years or older (hazard ratio ¼2.7, 95% CI: 1.9 4.1) compared with 50 59 years, and for those with a previous alcohol related hospital admission (hazard ratio¼2.5, 95% CI: 1.7 3.7). The risk of individuals diagnosed with HCV developing HCC was greatlyincreased compared with the general Scottish population (standardised incidence ratio¼127, 95% CI: 102 156). Owing to the advancing age of the Scottish HCV diagnosed population, the annual number of HCC cases is projected to increase, with a consequent increasing burden on the public healthcare system
Accurate ab initio spin densities
We present an approach for the calculation of spin density distributions for
molecules that require very large active spaces for a qualitatively correct
description of their electronic structure. Our approach is based on the
density-matrix renormalization group (DMRG) algorithm to calculate the spin
density matrix elements as basic quantity for the spatially resolved spin
density distribution. The spin density matrix elements are directly determined
from the second-quantized elementary operators optimized by the DMRG algorithm.
As an analytic convergence criterion for the spin density distribution, we
employ our recently developed sampling-reconstruction scheme [J. Chem. Phys.
2011, 134, 224101] to build an accurate complete-active-space
configuration-interaction (CASCI) wave function from the optimized matrix
product states. The spin density matrix elements can then also be determined as
an expectation value employing the reconstructed wave function expansion.
Furthermore, the explicit reconstruction of a CASCI-type wave function provides
insights into chemically interesting features of the molecule under study such
as the distribution of - and -electrons in terms of Slater
determinants, CI coefficients, and natural orbitals. The methodology is applied
to an iron nitrosyl complex which we have identified as a challenging system
for standard approaches [J. Chem. Theory Comput. 2011, 7, 2740].Comment: 37 pages, 13 figure
Importancia del agua en la hidratación de la población española: documento FESNAD 2010
For any healthy individual, thirst is an appropriate sign to drink water, except for babies, sportsmen, and most of ill and elderly people. In these instances, it is convenient to schedule appropriate times to drink water since great demands and the physiological mechanisms that determine thirst in these situations may condition water unbalances with important consequences for health and the physical and intellectual performance. The human body has a number of mechanisms that allow keeping constant the water content by adjusting intakes and wastes. Water balance is determined by intake (consumed water, beverages, and water contained in foods) and wastes (urine, stools, the skin, and expired air from the lungs). Failure of these mechanisms and subsequent impairments in water balance may produce severe disarrangements that may threaten somebody's life. In the present document, we analyze the evidences regarding the factors conditioning water needs in the different life stages and physiological situations, as well as the consequences of water unbalance under different situations. A proper hydration may be achieved by feeding and the use of water and other liquids. Although water is the beverage by excellence and represents the ideal way of restoring the losses and get hydrated, we should be aware that, from the very beginning, we have sought other liquid sources with hydration properties. In the last decades we have increased the consumption of different beverages, with a proliferation of sugar-containing beverages. Since excessive sugar consumption has been related to obesity and other chronic conditions, it is evident that the use of these caloric beverages should be rationalized, especially in children. In this document all the considerations regarding hydration are presented and different recommendations are expose
- …