170 research outputs found
Experimental Behavior of Sulfur Under Primitive Planetary Differentiation Processes, the Sulfide Formations in Enstatite Meteorites and Implications for Mercury.
Enstatite meteorites are the most reduced naturally-occuring materials of the solar system. The cubic monosulfide series with the general formula (Mg,Mn,Ca,Fe)S are common phases in these meteorite groups. The importance of such minerals, their formation, composition and textural relationships for understanding the genesis of enstatite chondrites (EC) and aubrites, has long been recognized (e.g. [1]). However, the mechanisms of formation of these sulfides is still not well constrained certainly because of possible multiple ways to produce them. We propose to simulate different models of formation in order to check their mineralogical, chemical and textural relevancies. The solubility of sulfur in silicate melts is of primary interest for planetary mantles, particularly for the Earth and Mercury. Indeed, these two planets could have formed, at least partly, from EC materials (e.g. [2, 3, 4]). The sulfur content in silicate melts depends on the melt composition but also on pressure (P), temperature (T) and oxygen fugacity fO2. Unfortunately, there is no model of general validity in a wide range of P-T-fO2-composition which describes precisely the evolution of sulfur content in silicate melts, even if the main trends are now known. The second goal of this study is to constrain the sulfur content in silicate melts under reducing conditions and different temperatures
Protean proteases: At the cutting edge of lung diseases
Proteases were traditionally viewed as mere protein-degrading enzymes with a very restricted spectrum of substrates. A major expansion in protease research has uncovered a variety of novel substrates, and it is now evident that proteases are critical pleiotropic actors orchestrating pathophysiological processes. Recent findings evidenced that the net proteolytic activity also relies upon interconnections between different protease and protease inhibitor families in the protease web.In this review, we provide an overview of these novel concepts with a particular focus on pulmonary pathophysiology. We describe the emerging roles of several protease families including cysteine and serine proteases.The complexity of the protease web is exemplified in the light of multidimensional regulation of serine protease activity by matrix metalloproteases through cognate serine protease inhibitor processing. Finally, we will highlight how deregulated protease activity during pulmonary pathogenesis may be exploited for diagnosis/prognosis purposes, and utilised as a therapeutic tool using nanotechnologies.Considering proteases as part of an integrative biology perspective may pave the way for the development of new therapeutic targets to treat pulmonary diseases related to intrinsic protease deregulation
Mild Dyslipidemia in Mice following Targeted Inactivation of the Hepatic Lipase Gene
In order to gain better understanding of the function of hepatic lipase (HL) in vivo, we have generated mice that lack HL using gene targeting in embryonic stem cells. No mRNA for HL was detected in the liver of homozygous mutants, and no HL activity was detected in their plasma. Total cholesterol levels in plasma of mutant mice were increased by about 30% compared with wild type animals. Plasma phospholipids and high density lipoprotein (HDL) cholesterol were also increased, but plasma levels of triglycerides were not altered. Analysis of density fractions of plasma lipoproteins revealed that HDL1 (d = 1.02-1.04) was increased in homozygous mutants fed regular chow. In response to a diet containing high fat and high cholesterol, HDL cholesterol was doubled in the mutants, but was slightly decreased in the wild type mice. These results clearly demonstrate the importance of HL in HDL remodeling and metabolism in vivo. Various earlier studies suggested a role of HL in metabolism of triglyceride-rich particles, but the mutant mice appear to have no impairment in clearing them; the mutants clear exogenously introduced chylomicrons from plasma at a normal rate, and they tolerate acute fat loading as well as normal animals unless the loading is extreme. These differences may reflect species differences. However, it is also possible that the consequence of absence of HL as in our mutants is different from the consequence when nonfunctional HL protein is present as in the human HL-deficient patients and in rats treated with HL antibodies. We hypothesize that absence of HL in mutant mice allows other lipases to bind to the sites in the liver normally occupied by HL and facilitate the clearance of triglyceride-rich particles in these mice
Parents’ experiences with a sick or injured child during the COVID-19 lockdown: an online survey in the Netherlands
ObjectiveTo assess the impact of the COVID-19 lockdown on parents’ health-seeking behaviour and care for a sick or injured child in the Netherlands.Design and settingAn online survey on parents’ experiences with a sick or injured child during the COVID-19 lockdown periods was disseminated through social media.ParticipantsParents living in the Netherlands with a sick or injured child during the lockdown periods from March to June 2020 and from December 2020 to February 2021 were eligible to participate.Outcome measuresDescriptive statistics and thematic analysis were used to analyse family and children’s characteristics, parents’ response to a sick or injured child, and the perceived impact of the lockdown on child’s severity of illness and treatment reported by parents. Analyses were stratified for children with and without chronic conditions.ResultsOf the 105 parents who completed the survey, 83% reported they would have sought medical help before lockdown compared with 88% who did seek help during lockdown for the same specific medical problem. Parents reported that changes in health services affected their child’s severity of illness (31%) and their treatment (39%), especially for children with chronic conditions. These changes included less availability of healthcare services and long waiting lists, which mostly led to worsening of the child’s illness. During lockdown, there was no change in health-seeking behaviour by parents of children with a chronic condition (N=51) compared with parents of children without a chronic condition.ConclusionParents in the Netherlands who completed the survey were not deterred from seeking medical help for their sick or injured child during the COVID-19 lockdown periods. However, changes in health services affected child’s severity of illness and treatment, especially for children with chronic conditions.</jats:sec
Sex-specific differences in children attending the emergency department: prospective observational study
Objective To assess the role of sex in the presentation
and management of children attending the emergency
department (ED).
Design The TrIAGE project (TRiage Improvements Across
General Emergency departments), a prospective observational
study based on curated electronic health record data.
Setting Five diverse European hospitals in four countries
(Austria, The Netherlands, Portugal, UK).
Participants All consecutive paediatric ED visits of
children under the age of 16 during the study period (8–36
months between 2012 and 2015).
Main outcome measures The association between
sex (male of female) and diagnostic tests and disease
management in general paediatric ED visits and in
subgroups presenting with trauma or musculoskeletal,
gastrointestinal and respiratory problems and fever.
Results from the different hospitals were pooled in a
random effects meta-analysis.
Results 116172 ED visits were included of which
63042 (54%) by boys and 53715 (46%) by girls. Boys
accounted for the majority of ED visits in childhood, and
girls in adolescence. After adjusting for age, triage urgency
and clinical presentation, girls had more laboratory tests
compared with boys (pooled OR 1.10, 95%CI 1.05 to 1.15).
Additionally, girls had more laboratory tests in ED visits for
respiratory problems (pooled OR 1.15, 95%CI 1.04 to 1.26)
and more imaging in visits for trauma or musculoskeletal
problems (pooled OR
Presentations of children to emergency departments across Europe and the COVID-19 pandemic: A multinational observational study
BACKGROUND: During the initial phase of the Coronavirus Disease 2019 (COVID-19) pandemic, reduced numbers of acutely ill or injured children presented to emergency departments (EDs). Concerns were raised about the potential for delayed and more severe presentations and an increase in diagnoses such as diabetic ketoacidosis and mental health issues. This multinational observational study aimed to study the number of children presenting to EDs across Europe during the early COVID-19 pandemic and factors influencing this and to investigate changes in severity of illness and diagnoses. METHODS AND FINDINGS: Routine health data were extracted retrospectively from electronic patient records of children aged 18 years and under, presenting to 38 EDs in 16 European countries for the period January 2018 to May 2020, using predefined and standardized data domains. Observed and predicted numbers of ED attendances were calculated for the period February 2020 to May 2020. Poisson models and incidence rate ratios (IRRs), using predicted counts for each site as offset to adjust for case-mix differences, were used to compare age groups, diagnoses, and outcomes. Reductions in pediatric ED attendances, hospital admissions, and high triage urgencies were seen in all participating sites. ED attendances were relatively higher in countries with lower SARS-CoV-2 prevalence (IRR 2.26, 95% CI 1.90 to 2.70, p < 0.001) and in children aged <12 months (12 to <24 months IRR 0.86, 95% CI 0.84 to 0.89; 2 to <5 years IRR 0.80, 95% CI 0.78 to 0.82; 5 to <12 years IRR 0.68, 95% CI 0.67 to 0.70; 12 to 18 years IRR 0.72, 95% CI 0.70 to 0.74; versus age <12 months as reference group, p < 0.001). The lowering of pediatric intensive care admissions was not as great as that of general admissions (IRR 1.30, 95% CI 1.16 to 1.45, p < 0.001). Lower triage urgencies were reduced more than higher triage urgencies (urgent triage IRR 1.10, 95% CI 1.08 to 1.12; emergent and very urgent triage IRR 1.53, 95% CI 1.49 to 1.57; versus nonurgent triage category, p < 0.001). Reductions were highest and sustained throughout the study period for children with communicable infectious diseases. The main limitation was the retrospective nature of the study, using routine clinical data from a wide range of European hospitals and health systems. CONCLUSIONS: Reductions in ED attendances were seen across Europe during the first COVID-19 lockdown period. More severely ill children continued to attend hospital more frequently compared to those with minor injuries and illnesses, although absolute numbers fell. TRIAL REGISTRATION: ISRCTN91495258 https://www.isrctn.com/ISRCTN91495258
Management of children visiting the emergency department during out-of-office hours: An observational study
Background The aim was to study the characteristics
and management of children visiting the emergency
department (ED) during out-of-office hours.
Methods We analysed electronic health record data from
119 204 children visiting one of five EDs in four European
countries. Patient characteristics and management
(diagnostic tests, treatment, hospital admission and
paediatric intensive care unit admission) were compared
between children visiting during office hours and evening
shifts, night shifts and weekend day shifts. Analyses were
corrected for age, gender, Manchester Triage System
urgency, abnormal vital signs, presenting problems and
hospital.
Results Patients presenting at night were younger
(median (IQR) age: 3.7 (1.4–8.2) years vs 4.8 (1.8–9.9)),
more often classified as high urgent (16.3% vs 9.9%) and
more often had ≥2 abnormal vital signs (22.8% vs 18.1%)
compared with office hours. After correcting for disease
severity, laboratory and radiological tests were less likely
to be requested (adjusted OR (aOR): 0.82, 95% CI 0.78–
0.86 and aOR: 0.64, 95% CI 0.60–0.67, respectively);
treatment
- …