79 research outputs found
A Pneumococcal Carriage Study in Danish Pre-school Children before the Introduction of Pneumococcal Conjugate Vaccination
We present data on pneumococcal carriage before the introduction of the heptavalent-pneumococcal conjugated vaccine (PCV7) in Denmark. In the pre-PCV7 period, the incidence of invasive pneumococcal disease (IPD) among children younger than 5 years was approximately 25 per 100.000 population, with the highest incidence rates observed in children younger than 2 years of age. The study included 437 children aged 12-72 months attending day care centres (DCC) and was conducted during 48 months. In total, 56% (n=247) of children were pneumococcal carriers with the highest prevalence in children aged 12–23 months (69%), the proportion significantly declining with increasing age. PCV7 serotypes accounted for 33%, PCV10 for 34%, and PCV13 for 57% of all carried isolates. The proportion of serotypes included in the three conjugate vaccines was higher among IPD isolates compared to carrier isolates (range 35– 90%). We found that the frequency of carriage was high among Danish pre-school children attending DCC and serotypes were not frequently covered by PCV7 in the pre-PCV7 period
SARS-CoV-2 and risk of psychiatric hospital admission and use of psychopharmaceuticals: A nationwide registry study of 4,585,083 adult Danish citizens
Abstract
Background
Current evidence on the risk of admission- or medication-requiring psychiatric sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is limited to selected populations, short durations, and loss to follow-up. This study examined if SARS-CoV-2 infection was associated with increased long-term risk of psychiatric admissions and de novo prescription of psychoactive medication in the general population of Denmark.
Methods
Adults (≥18 years) were assigned to either the control or SARS-CoV-2 group based on polymerase chain reaction (PCR) tests between 1 January 2020 and 27 November 2021. Infected subjects were matched 1:5 to control subjects by propensity score. Incidence rate ratios (IRRs) were calculated. Adjusted Cox regression was applied to the unmatched population with SARS-CoV-2 infection as a time-dependent covariate. Follow-up time was 12 months or until the end of the study.
Results
A total of 4,585,083 adults were included in the study. Approximately 342,084 had a PCR-confirmed SARS-CoV-2 infection and were matched 1:5 with 1,697,680 controls. The IRR for psychiatric admission was 0.79 in the matched population (95% confidence interval [CI]: 0.73–0.85, p < 0.001). In the unmatched population, the adjusted hazard ratios (aHR) for psychiatric admission were either below 1.00 or with a 95% CI lower limit of 1.01. SARS-CoV-2 infection was associated with an increased risk of de novo prescription of psychoactive medication in both the matched (IRR 1.06, 95% CI: 1.02–1.11, p < 0.01) and unmatched population (HR 1.31, 95% CI: 1.28–1.34, p < 0.001).
Conclusions
We found a signal of increased use of psychoactive medication, specifically benzodiazepines, among SARS-CoV-2-positive persons, but the risk of psychiatric admissions did not increase
Investigation of tumor hypoxia using a two-enzyme system for in vitro generation of oxygen deficiency
<p>Abstract</p> <p>Background</p> <p>Oxygen deficiency in tumor tissue is associated with a malign phenotype, characterized by high invasiveness, increased metastatic potential and poor prognosis. Hypoxia chambers are the established standard model for <it>in vitro </it>studies on tumor hypoxia. An enzymatic hypoxia system (GOX/CAT) based on the use of glucose oxidase (GOX) and catalase (CAT) that allows induction of stable hypoxia for <it>in vitro </it>approaches more rapidly and with less operating expense has been introduced recently. Aim of this work is to compare the enzymatic system with the established technique of hypoxia chamber in respect of gene expression, glucose metabolism and radioresistance, prior to its application for <it>in vitro </it>investigation of oxygen deficiency.</p> <p>Methods</p> <p>Human head and neck squamous cell carcinoma HNO97 cells were incubated under normoxic and hypoxic conditions using both hypoxia chamber and the enzymatic model. Gene expression was investigated using Agilent microarray chips and real time PCR analysis. <sup>14</sup>C-fluoro-deoxy-glucose uptake experiments were performed in order to evaluate cellular metabolism. Cell proliferation after photon irradiation was investigated for evaluation of radioresistance under normoxia and hypoxia using both a hypoxia chamber and the enzymatic system.</p> <p>Results</p> <p>The microarray analysis revealed a similar trend in the expression of known HIF-1 target genes between the two hypoxia systems for HNO97 cells. Quantitative RT-PCR demonstrated different kinetic patterns in the expression of carbonic anhydrase IX and lysyl oxidase, which might be due to the faster induction of hypoxia by the enzymatic system. <sup>14</sup>C-fluoro-deoxy-glucose uptake assays showed a higher glucose metabolism under hypoxic conditions, especially for the enzymatic system. Proliferation experiments after photon irradiation revealed increased survival rates for the enzymatic model compared to hypoxia chamber and normoxia, indicating enhanced resistance to irradiation. While the GOX/CAT system allows independent investigation of hypoxia and oxidative stress, care must be taken to prevent acidification during longer incubation.</p> <p>Conclusion</p> <p>The results of our study indicate that the enzymatic model can find application for <it>in vitro </it>investigation of tumor hypoxia, despite limitations that need to be considered in the experimental design.</p
Pediatric invasive pneumococcal disease caused by vaccine serotypes following the introduction of conjugate vaccination in Denmark.
A seven-valent pneumococcal conjugate vaccine (PCV7) was introduced in the Danish childhood immunization program (2+1 schedule) in October 2007, followed by PCV13 starting from April 2010. The nationwide incidence of IPD among children younger than 5 years nearly halved after the introduction of PCV7 in the program, mainly due to a decline in IPD caused by PCV7-serotypes. We report the results from a nationwide population-based cohort study of laboratory confirmed IPD cases in children younger than 5 years during October 1, 2007 to December 31, 2010 and describe the characteristics of children suspected to present with a vaccine failure. The period between April 19 and December 31, 2010 was considered a PCV7/PCV13 transitional period, where both vaccines were offered. We identified 45 episodes of IPD caused by a PCV7 serotype (23% of the total number) and 105 (55%) caused by one of the 6 additional serotypes in PCV13. Ten children had received at least one PCV7 dose before the onset of IPD caused by a PCV7 serotype. Seven children were considered to be incompletely vaccinated before IPD, but only three cases fulfilled the criteria of vaccine failure (caused by serotypes 14, 19F and 23F). One case of vaccine failure was observed in a severely immunosuppressed child following three PCV7 doses, and two cases were observed in immunocompetent children following two infant doses before they were eligible for their booster. None of the IPD cases caused by the additional PCV13 serotypes had been vaccinated by PCV13 and there were therefore no PCV13-vaccine failures in the first 8-months after PCV13 introduction in Denmark
Pneumococcal Serotypes and Mortality following Invasive Pneumococcal Disease: A Population-Based Cohort Study
Analyzing population-based data collected over 30 years in more than 18,000 patients with invasive pneumococcal infection, Zitta Harboe and colleagues find specific pneumococcal serotypes to be associated with increased mortality
Nitric Oxide Synthase Inhibitors into the Clinic at Last
The 1998 nobel prize in medicine and physiology for the discovery of nitric oxide, a nitrogen containing reactive oxygen species (also termed reactive nitrogen or reactive nitrogen/oxygen species) stirred great hopes. Clinical applications, however, have so far pertained exclusively to the downstream signaling of cgmp enhancing drugs such as phosphodiesterase inhibitors and soluble guanylate cyclase stimulators. All clinical attempts, so far, to inhibit nos have failed even though preclinical models were strikingly positive and clinical biomarkers correlated perfectly. This rather casts doubt on our current way of target identification in drug discovery in general and our way of patient stratification based on correlating but not causal biomarkers or symptoms. The opposite, no donors, nitrite and enhancing no synthesis by enos/nos3 recoupling in situations of no deficiency, are rapidly declining in clinical relevance or hold promise but need yet to enter formal therapeutic guidelines, respectively. Nevertheless, nos inhibition in situations of no overproduction often jointly with enhanced superoxide (or hydrogen peroxide production) still holds promise, but most likely only in acute conditions such as neurotrauma (stover et al., j neurotrauma 31(19):1599–1606, 2014) and stroke (kleinschnitz et al., j cereb blood flow metab 1508–1512, 2016; casas et al., proc natl acad sci u s a 116(14):7129–7136, 2019). Conversely, in chronic conditions, long-term inhibition of nos might be too risky because of off-target effects on enos/nos3 in particular for patients with cardiovascular risks or metabolic and renal diseases.graphical abstractnitric oxide synthases (nos) and their role in health (green) and disease (red). Only neuronal/type 1 nos (nos1) has a high degree of clinical validation and is in late stage development for traumatic brain injury, followed by a phase ii safety/efficacy trial in ischemic stroke. The pathophysiology of nos1 (kleinschnitz et al., j cereb blood flow metab 1508–1512, 2016) is likely to be related to parallel superoxide or hydrogen peroxide formation (kleinschnitz et al., j cereb blood flow metab 1508–1512, 2016; casas et al., proc natl acad sci u s a 114(46):12315–12320, 2017; casas et al., proc natl acad sci u s a 116(14):7129–7136, 2019) leading to peroxynitrite and protein nitration, etc. Endothelial/type 3 nos (nos3) is considered protective only and its inhibition should be avoided. The preclinical evidence for a role of high-output inducible/type 2 nos (nos2) isoform in sepsis, asthma, rheumatic arthritis, etc. Was high, but all clinical development trials in these indications were neutral despite target engagement being validated. This casts doubt on the role of nos2 in humans in health and disease (hence the neutral, black coloring).keywordsnitric oxidenitric oxide synthasenosnos inhibitor nos isoforms
HYPOXIC STRESS, HEPATOCYTES AND CACO-2 VIABILITY AND SUSCEPTIBILITY TO Shigella flexneri INVASION
SUMMARY Inflammation due to Shigella flexneri can cause damage to the colonic mucosa and cell death by necrosis and apoptosis. This bacteria can reach the bloodstream in this way, and the liver through portal veins. Hypoxia is a condition present in many human diseases, and it may induce bacterial translocation from intestinal lumen. We studied the ability of S. flexneri to invade rat hepatocytes and Caco-2 cells both in normoxic and hypoxic microenvironments, as well as morphological and physiological alterations in these cells after infection under hypoxia. We used the primary culture of rat hepatocytes as a model of study. We analyzed the following parameters in normoxic and hypoxic conditions: morphology, cell viability, bacterial recovery and lactate dehydrogenase (LDH) released. The results showed that there were fewer bacteria within the Caco-2 cells than in hepatocytes in normoxic and hypoxic conditions. We observed that the higher the multiplicity of infection (MOI) the greater the bacterial recovery in hepatocytes. The hypoxic condition decreased the bacterial recovery in hepatocytes. The cytotoxicity evaluated by LDH released by cells was significantly higher in cells submitted to hypoxia than normoxia. Caco-2 cells in normoxia released 63% more LDH than hepatocytes. LDH increased 164% when hepatocytes were submitted to hypoxia and just 21% when Caco-2 cells were in the same condition. The apoptosis evaluated by Tunel was significantly higher in cells submitted to hypoxia than normoxia. When comparing hypoxic cells, we obtained more apoptotic hepatocytes than apoptotic Caco-2 cells. Concluding our results contribute to a better knowledge of interactions between studied cells and Shigella flexneri. These data may be useful in the future to define strategies to combat this virulent pathogen
Do different anesthesia regimes affect hippocampal apoptosis and neurologic deficits in a rodent cardiac arrest model?
N-acetylglucosaminidase participation during the hamster gametes interaction
La interacción entre gametas está mediada por los oligosacáridos de la cubierta del ovocito (la zona pelúcida, ZP) y proteínas complementarias del espermatozoide. En este trabajo se estudió la participación de los carbohidratos en las distintas etapas del proceso de interacción entre el espermatozoide de hámster y ZP. La presencia de GlcNAc fue capaz de inhibir la unión del espermatozoide a la ZP, revelando que es el azúcar más relevante en este proceso de interacción. El monosacárido también inhibió la reacción acrosomal (RA) espontánea e inducida por ZP. Usando un modelo que nos permitió tener capacitación y unión a ZP sin RA, pudimos verificar que la GlcNAc está involucrada en la unión primaria a través de sitios de unión para el azúcar en el espermatozoide. Utilizando ensayos de fertilización in vitro (FIV), analizamos la participación de GlcNAc en los diferentes pasos de la interacción espermatozoide-ovocito, pero no hallamos evidencias de su participación más allá de la unión primaria. La ZP fue reconocida como un ligando por la β-N-acetilglucosaminidasa (NAG) de espermatozoides de hámster. Esta enzima estaría distribuida en dos poblaciones: una acrosomal y otra débilmente asociada a la membrana plasmática. La actividad total de NAG disminuyó como consecuencia de la activación y liberación de un modulador luego de la capacitación y RA. Ligandos de NAG fueron capaces de inhibir la unión primaria del espermatozoide a la ZP. En ensayos de FIV, no se detectó efecto alguno cuando un inhibidor de NAG fue agregado luego de que la unión primaria tuviera lugar. Por otro lado, el agregado de NAG exógena fue capaz de inhibir la interacción entre gametas. En conclusión, los resultados presentados en este trabajo indican que una NAG de membrana del espermatozoide actuaría como proteína de unión para los residuos GlcNAc terminales de la ZP, mediando de esta manera la unión primaria entre ambas gametas.Gamete interaction is mediated by the oligosaccharides of the egg extracellular coat (the zona pellucida, ZP) and complementary proteins in the spermatozoa. In this study, the participation of carbohydrates in the different steps of hamster sperm interaction with the ZP was analyzed. The presence of GlcNAc inhibited sperm binding to the ZP, revealing that it is the most relevant sugar in this interaction process. The monosaccharide also inhibited the spontaneous and ZP-induced acrosome reaction (AR). Taken advantage of a method that allowed capacitation and ZP binding without AR, the involvement of sperm GlcNAc binding sites in primary binding to the ZP was verified. Carrying out in vitro fertilization (IVF) assays, the participation of GlcNAc in the different steps involved in sperm-oocyte interaction was analyzed, but no evidences for its involvement beyond primary binding was found. Soluble ZP was recognized as a ligand by the hamster sperm β-N-acetylglucosaminidase (NAG). This enzyme seems to be distributed in two populations in sperm: one within the acrosome and another one weakly associated to the plasma membrane. Total NAG activity diminished as a consequence of the activation and release of a regulatory molecule after capacitation and AR. NAG ligands were able to inhibit sperm primary binding to ZP. During IVF assays, no effect was detected when a NAG inhibitor was added after primary binding took place. Additionally, exogenous NAG was able to inhibit gamete interaction. In conclusion, results suggest that a membrane sperm NAG would be acting as a binding protein for the ZP terminal GlcNAc residues during primary binding between gametes.Fil: Zitta, Karina S.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
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