Novel mRNA-specific effects of ribosome drop-off on translation rate and polysome profile.

The well established phenomenon of ribosome drop-off plays crucial roles in translational accuracy and nutrient starvation responses during protein translation. When cells are under stress conditions, such as amino acid starvation or aminoacyl-tRNA depletion due to a high level of recombinant protein expression, ribosome drop-off can substantially affect the efficiency of protein expression. Here we introduce a mathematical model that describes the effects of ribosome drop-off on the ribosome density along the mRNA and on the concomitant protein synthesis rate. Our results show that ribosome premature termination may lead to non-intuitive ribosome density profiles, such as a ribosome density which increases from the 5' to the 3' end. Importantly, the model predicts that the effects of ribosome drop-off on the translation rate are mRNA-specific, and we quantify their resilience to drop-off, showing that the mRNAs which present ribosome queues are much less affected by ribosome drop-off than those which do not. Moreover, among those mRNAs that do not present ribosome queues, resilience to drop-off correlates positively with the elongation rate, so that sequences using fast codons are expected to be less affected by ribosome drop-off. This result is consistent with a genome-wide analysis of S. cerevisiae, which reveals that under favourable growth conditions mRNAs coding for proteins involved in the translation machinery, known to be highly codon biased and using preferentially fast codons, are highly resilient to ribosome drop-off. Moreover, in physiological conditions, the translation rate of mRNAs coding for regulatory, stress-related proteins, is less resilient to ribosome drop-off. This model therefore allows analysis of variations in the translational efficiency of individual mRNAs by accounting for the full range of known ribosome behaviours, as well as explaining mRNA-specific variations in ribosome density emerging from ribosome profiling studies.

Health related quality of life in patients with community-acquired pneumococcal pneumonia in France.

BACKGROUND: Community Acquired Pneumococcal Pneumonia is a lung infection that causes serious health problems and can lead to complications and death. The aim of this study was to observe and analyze health related quality of life after a hospital episode for patients with community acquired pneumococcal pneumonia in France. METHODS: A total of 524 individuals were enrolled prospectively in the study and were followed for 12 months after hospital discharge. Presence of streptococcus pneumoniae was confirmed by microbiological sampling. Quality of life was reported at four different points of time with the EQ-5D-3 L health states using the French reference tariff. Complete data on all four periods was available for 269 patients. We used descriptive and econometric analysis to assess quality of life over time during follow-up, and to identify factors that impact the utility indexes and their evolution through time. We used Tobit panel data estimators to deal with the bounded nature of utility values. RESULTS: Average age of patients was 63 and 55% of patients were men. Negative predictors of quality of life were the severity of the initial event, history of pneumonia, smokers, age and being male. On average, quality of life improved in the first 6 months after discharge and stabilized beyond. At month 1, mean utility index was 0.53 (SD: 0.34) for men and 0.45 (SD: 0.34) for women, versus mean of 0.69 (SD: 0.33) and 0.70 (SD: 0.35) at Month 12. "Usual activities" was the dimension the most impacted by the disease episode. Utilities for men were significantly higher than for women, although male patients were more severe. Individuals over 85 years old did not improve quality of life during follow-up, and quality of life did not improve or deteriorated for 34% of patients. We found that length of hospital stay was negatively correlated with quality of life immediately after discharge. CONCLUSION: This study provides with evidence that quality of life after an episode of community acquired pneumococcal pneumonia improves overall until the sixth month after hospital discharge, but older patients with previous history of pneumonia may not experience health gains after the initial episode.

Ceftaroline for the treatment of prosthetic valve endocarditis due to methicillin-resistant Staphylococcus aureus.

The case is described of a frail patient who developed prosthetic valve endocarditis due to methicillin-resistant Staphylococcus aureus (MRSA). Conventional antimicrobial treatments either failed or were contraindicated, and the patient was judged unsuitable for a further valve replacement. A salvage therapy with high doses of a new cephalosporin, ceftaroline, given three times daily was undertaken; subsequently, the patient had not relapsed at two months after completing a six-week course of ceftaroline. Ceftaroline deserves major attention as an alternative choice in difficult-to-treat MRSA endocarditis.

Two-species totally asymmetric simple exclusion process model: From a simple description to intermittency and traveling traffic jams.

We extend the paradigmatic and versatile totally asymmetric simple exclusion process (TASEP) for stochastic 1D transport to allow for two different particle species, each having specific entry and exit rates. We offer a complete mean-field analysis, including a phase diagram, by mapping this model onto an effective one-species TASEP. Stochastic simulations confirm the results, but indicate deviations when the particle species have very different exit rates. We illustrate that this is due to a phenomenon of intermittency, and formulate a refined "intermittent" mean-field theory for this regime. We discuss how nonstationary effects may further enrich the phenomenology.

Trends in the relation between hyperglycemia correction and active Charcot neuroarthropathy: results from the EPICHAR study.

INTRODUCTION: The pathophysiology of Charcot neuroarthropathy (CN) remains unclear. There are a number of hypotheses but these are not exclusive. In its clinical presentation, this complication intersects with the semiology of diabetic-induced neuropathy, such as peripheral hypervascularization and the appearance of arteriovenous shunt. The EPICHAR study is as yet an unpublished cohort of people living with diabetes complicated by CN (in active or chronic phase). Based on the findings of the EPICHAR study, this study aimed to investigate whether a reduction in the rate of hyperglycemia accompanies the onset of an active phase of CN. RESEARCH DESIGN AND METHODS: Hemoglobin A1c (HbA1c) levels were assessed 3 months (M3) and 6 months (M6) before the diagnosis of active CN (M0). RESULTS: 103 patients living with diabetes and presenting active CN were included between January and December 2019 from the 31 centers participating in this study (30 in France and 1 in Belgium). The mean age of the participants was 60.2±12.2 years; the vast majority were men (71.8%) living with type 2 diabetes (75.5%). Mean HbA1c levels significantly declined between M6 (median 7.70; Q1, Q3: 7.00, 8.55) and M3 (median 7.65; Q1, Q3: 6.90, 8.50) (p=0.012), as well as between M6 and M0 (median 7.40; Q1, Q3: 6.50, 8.50) (p=0.014). No significant difference was found between M3 and M0 (p=0.072). CONCLUSIONS: A significant reduction in HbA1c levels seems to accompany the onset of the active phase of CN. TRIAL REGISTRATION NUMBER: NCM03744039.

Costs associated with community acquired pneumonia in France.

OBJECTIVES: Pneumocost is a prospective study that aimed at documenting the costs of the management of patients hospitalized with a pneumococcal pneumonia and the post-discharge costs during a 6-month period in the French context. METHODS: Billing data were used to document hospital costs. Resource use during the follow-up period was collected through phone interviews at month 1, 3 and 6. Descriptive statistics and multivariate analyses were performed. We used generalized linear models with log-link functions to estimate parameters associated with hospital and follow-up costs of patients. RESULTS: Five hundred twenty-four patients were enrolled in 40 public centers from October 2011 to April 2014. Average age was 63 (SD 17); 55.0% of them were male. Average length of stay was 15 days (SD 23). Average cost of stay for the French Sickness Fund was €7293 (SD €7363). Average cost of follow-up was €1242 (SD €3000) and decreased steadily through time. When controlling for patient's socioeconomic characteristics, severity of disease and hospital stay, results showed a concave relationship between hospital costs and age. Obesity, the severity of the disease and comorbidities were associated with constantly increasing inpatient costs. Concerning follow-up costs, we found the same concave relationship with age, while gender, a history of pneumonia and severity of the disease were the most important predictors of high costs after discharge. CONCLUSION: Pneumocost is the first French study providing a robust estimation of the cost of managing invasive pneumococcal pneumonia in the French context.

An Addison disease revealed with a serious hyponatremia.

We present the case of an Addison's disease revealed by a serious hyponatremia. The serum concentration of ACTH and 21-hydroxylase antibodies were increased and lead to the diagnosis. The cortisol blood level was lowered but required to take into account the stress induced by the hospitalisation of the patient. Addison's disease is characterized by the destruction of the adrenal cortex. Autoimmune adrenalitis is the main cause of adrenal insufficiency. Treatment involves normalisation of sodium concentration and corticosteroids replacement. With a good patient compliance, the survival rate of Addisonian patient is similar to that of the normal population. Management of patient requires vigilance because of the occurrence of others autoimmunes diseases during patient life.

Genotyping of Candida albicans oral strains from healthy individuals by polymorphic microsatellite locus analysis.

Analysis of a polymorphic microsatellite locus was applied to 85 Candida albicans strains from healthy individuals. Comparison with strains from nonhealthy individuals previously analyzed in our laboratory showed an overall similarity, suggesting that all commensal strains have the ability to develop as pathogens.