Age-related differences in perception and coding of attractive odorants in mice

Hedonic perception deeply changes with aging, significantly impacting health and quality of life in elderly. In young adult mice, an odor hedonic signature is represented along the antero-posterior axis of olfactory bulb, and transferred to the olfactory tubercle and ventral tegmental area, promoting approach behavior. Here, we show that while the perception of unattractive odorants was unchanged in older mice (22 months), the appreciation of some but not all attractive odorants declined. Neural activity in the olfactory bulb and tubercle of older mice was consistently altered when attraction to pleasant odorants was impaired while maintained when the odorants kept their attractivity. Finally, in a self-stimulation paradigm, optogenetic stimulation of the olfactory bulb remained rewarding in older mice even without ventral tegmental area's response to the stimulation. Aging degrades behavioral and neural responses to some pleasant odorants but rewarding properties of olfactory bulb stimulation persisted, providing new insights into developing novel olfactory training strategies to elicit motivation even when the dopaminergic system is altered as observed in normal and/or neurodegenerative aging.

Long-term olfactory enrichment promotes non-olfactory cognition, noradrenergic plasticity and remodeling of brain functional connectivity in older mice

Brain functional and structural changes lead to cognitive decline during aging, but a high level of cognitive stimulation during life can improve cognitive performances in the older adults, forming the cognitive reserve. Noradrenaline has been proposed as a molecular link between environmental stimulation and constitution of the cognitive reserve. Taking advantage of the ability of olfactory stimulation to activate noradrenergic neurons of the locus coeruleus, we used repeated olfactory enrichment sessions over the mouse lifespan to enable the cognitive reserve buildup. Mice submitted to olfactory enrichment, whether started in early or late adulthood, displayed improved olfactory discrimination at late ages and interestingly, improved spatial memory and cognitive flexibility. Moreover, olfactory and non-olfactory cognitive performances correlated with increased noradrenergic innervation in the olfactory bulb and dorsal hippocampus. Finally, c-Fos mapping and connectivity analysis revealed task-specific remodeling of functional neural networks in enriched older mice. Long-term olfactory enrichment thus triggers structural noradrenergic plasticity and network remodeling associated with better cognitive aging and thereby forms a promising mouse model of the cognitive reserve buildup.

Correlations between clinical motor scores and CMAP in patients with type 2 spinal muscular amyotrophy treated with nusinersen

BACKGROUND

Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by the degeneration of the anterior horn cells of the spinal cord. Nusinersen for the treatment of SMA has been covered by public healthcare in France since May 2017.

OBJECTIVE

Our aim was to investigate whether there is a correlation between clinical and compound motor action potential (CMAP) measurements in SMA patients treated with nusinersen after 3  years' follow-up.

METHOD

Motor skills were evaluated regularly between M0 and M36 using the Motor Function Measure (MFM) score. CMAP measurements were collected regularly between M0 and M22.

RESULTS

Data for 10 patients with SMA type 2 were collected and divided into two age groups (< 5 years and > 5 years). Motor function improved, but not significantly, regarding distal motor skills (D3) in both groups, and in axial and proximal motor function (D2) in the younger group. CMAP measurements improved in all patients. CMAP increased significantly for the median nerve, and this improvement correlated significantly with global MFM and with axial and proximal tone (D2).

CONCLUSION

Our study shows gain in distal motor function with nusinersen, especially in younger patients with SMA type 2. These results encourage the screening of SMA patients and treatment as early as possible. CMAP measurements of the median nerve show clear improvement in patients treated with nusinersen and could be performed as routine follow-up.

Prediction of therapeutic intensity level from automatic multiclass segmentation of traumatic brain injury lesions on CT-scans

The prediction of the therapeutic intensity level (TIL) for severe traumatic brain injury (TBI) patients at the early phase of intensive care unit (ICU) remains challenging. Computed tomography images are still manually quantified and then underexploited. In this study, we develop an artificial intelligence-based tool to segment brain lesions on admission CT-scan and predict TIL within the first week in the ICU. A cohort of 29 head injured patients (87 CT-scans; Dataset1) was used to localize (using a structural atlas), segment (manually or automatically with or without transfer learning) 4 or 7 types of lesions and use these metrics to train classifiers, evaluated with AUC on a nested cross-validation, to predict requirements for TIL sum of 11 points or more during the 8 first days in ICU. The validation of the performances of both segmentation and classification tasks was done with Dice and accuracy scores on a sub-dataset of Dataset1 (internal validation) and an external dataset of 12 TBI patients (12 CT-scans; Dataset2). Automatic 4-class segmentation (without transfer learning) was not able to correctly predict the apparition of a day of extreme TIL (AUC = 60 ± 23%). In contrast, manual quantification of volumes of 7 lesions and their spatial location provided a significantly better prediction power (AUC = 89 ± 17%). Transfer learning significantly improved the automatic 4-class segmentation (DICE scores 0.63 vs 0.34) and trained more efficiently a 7-class convolutional neural network (DICE = 0.64). Both validations showed that segmentations based on transfer learning were able to predict extreme TIL with better or equivalent accuracy (83%) as those made with manual segmentations. Our automatic characterization (volume, type and spatial location) of initial brain lesions observed on CT-scan, publicly available on a dedicated computing platform, could predict requirements for high TIL during the first 8 days after severe TBI. Transfer learning strategies may improve the accuracy of CNN-based segmentation models.Trial registrations Radiomic-TBI cohort; NCT04058379, first posted: 15 august 2019; Radioxy-TC cohort; Health Data Hub index F20220207212747, first posted: 7 February 2022.

Intracranial pressure monitoring with and without brain tissue oxygen pressure monitoring for severe traumatic brain injury in France (OXY-TC): an open-label, randomised controlled superiority trial

BACKGROUND

Optimisation of brain oxygenation might improve neurological outcome after traumatic brain injury. The OXY-TC trial explored the superiority of a strategy combining intracranial pressure and brain tissue oxygen pressure (PbtO2) monitoring over a strategy of intracranial pressure monitoring only to reduce the proportion of patients with poor neurological outcome at 6 months.

METHODS

We did an open-label, randomised controlled superiority trial at 25 French tertiary referral centres. Within 16 h of brain injury, patients with severe traumatic brain injury (aged 18-75 years) were randomly assigned via a website to be managed during the first 5 days of admission to the intensive care unit either by intracranial pressure monitoring only or by both intracranial pressure and PbtO2 monitoring. Randomisation was stratified by age and centre. The study was open label due to the visibility of the intervention, but the statisticians and outcome assessors were masked to group allocation. The therapeutic objectives were to maintain intracranial pressure of 20 mm Hg or lower, and to keep PbtO2 (for those in the dual-monitoring group) above 20 mm Hg, at all times. The primary outcome was the proportion of patients with an extended Glasgow Outcome Scale (GOSE) score of 1-4 (death to upper severe disability) at 6 months after injury. The primary analysis was reported in the modified intention-to-treat population, which comprised all randomly assigned patients except those who withdrew consent or had protocol violations. This trial is registered with ClinicalTrials.gov, NCT02754063, and is completed.

FINDINGS

Between June 15, 2016, and April 17, 2021, 318 patients were randomly assigned to receive either intracranial pressure monitoring only (n=160) or both intracranial pressure and PbtO2 monitoring (n=158). 27 individuals with protocol violations were not included in the modified intention-to-treat analysis. Thus, the primary outcome was analysed for 144 patients in the intracranial pressure only group and 147 patients in the intracranial pressure and PbtO2 group. Compared with intracranial pressure monitoring only, intracranial pressure and PbtO2 monitoring did not reduce the proportion of patients with GOSE score 1-4 (51% [95% CI 43-60] in the intracranial pressure monitoring only group vs 52% [43-60] in the intracranial pressure and PbtO2 monitoring group; odds ratio 1·0 [95% CI 0·6-1·7]; p=0·95). Two (1%) of 144 participants in the intracranial pressure only group and 12 (8%) of 147 participants in the intracranial pressure and PbtO2 group had catheter dysfunction (p=0.011). Six patients (4%) in the intracranial pressure and PbtO2 group had an intracrebral haematoma related to the catheter, compared with none in the intracranial pressure only group (p=0.030). No significant difference in deaths was found between the two groups at 12 months after injury. At 12 months, 33 deaths had occurred in the intracranial pressure group: 25 (76%) were attributable to the brain trauma, six (18%) were end-of-life decisions, and two (6%) due to sepsis. 34 deaths had occured in the intracranial pressure and PbtO2 group at 12 months: 25 (74%) were attributable to the brain trauma, six (18%) were end-of-life decisions, one (3%) due to pulmonary embolism, one (3%) due to haemorrhagic shock, and one (3%) due to cardiac arrest.

INTERPRETATION

After severe non-penetrating traumatic brain injury, intracranial pressure and PbtO2 monitoring did not reduce the proportion of patients with poor neurological outcome at 6 months. Technical failures related to intracerebral catheter and intracerebral haematoma were more frequent in the intracranial pressure and PbtO2 group. Further research is needed to assess whether a targeted approach to multimodal brain monitoring could be useful in subgroups of patients with severe traumatic brain injury-eg, those with high intracranial pressure on admission.

FUNDING

The French National Program for Clinical Research, La Fondation des Gueules Cassées, and Integra Lifesciences.

A randomized controlled trial of the intraoperative use of noninvasive ventilation versus supplemental oxygen by face mask for procedural sedation in an electrophysiology laboratory

PURPOSE

The efficacy of noninvasive ventilation (NIV) during procedures that require sedation and analgesia has not been established. We evaluated whether NIV reduces the incidence of respiratory events.

METHODS

In this randomized controlled trial, we included 195 patients with an American Society of Anesthesiologists Physical Status of III or IV during electrophysiology laboratory procedures. We compared NIV with face mask oxygen therapy for patients under sedation. The primary outcome was the incidence of respiratory events determined by a computer-driven blinded analysis and defined by hypoxemia (peripheral oxygen saturation < 90%) or apnea/hypopnea (absence of breathing for 20 sec on capnography). Secondary outcomes included hemodynamic variables, sedation, patient safety (composite scores of major or minor adverse events), and adverse outcomes at day 7.

RESULTS

A respiratory event occurred in 89/98 (95%) patients in the NIV group and in 69/97 (73%) patients with face masks (risk ratio [RR], 1.29; 95% confidence interval [CI], 1.13 to 1.47; P < 0.001). Hypoxemia occurred in 40 (42%) patients in the NIV group and in 33 (34%) patients with face masks (RR, 1.21; 95% CI, 0.84 to 1.74; P = 0.30). Apnea/hypopnea occurred in 83 patients (92%) in the NIV group vs 65 patients (70%) with face masks (RR, 1.32; 95% CI, 1.14 to 1.53; P < 0.001). Hemodynamic variables, sedation, major or minor safety events, and patient outcomes were not different between the groups.

CONCLUSIONS

Respiratory events were more frequent among patients receiving NIV without any safety or outcome impairment. These results do not support the routine use of NIV intraoperatively.

STUDY REGISTRATION

ClinicalTrials.gov (NCT02779998); registered 4 November 2015.

Validation of quantitative real-time PCR for detection of Legionella pneumophila in hospital water networks

BACKGROUND

Rapid monitoring of Legionella pneumophila (Lp) is essential to reduce the risk of Legionnaires' disease in healthcare facilities. However, culture results take at least eight days, delaying the implementation of corrective measures. Here, we assessed the performance of a qPCR method and determined qPCR action thresholds for the detection of Lp in hospital hot water networks (HWNs).

METHODS

Hot water samples (n=459) were collected from a hospital HWNs. Lp were quantified using iQ-Check® Quanti real-time PCR Quantification kits (Bio-Rad) and the results were compared with those of culture. qPCR thresholds corresponding to the culture action thresholds of 10 and 1,000 CFU/L were determined on a training dataset and validated on an independent dataset.

RESULTS

Lp concentrations measured by culture and qPCR were correlated for both the training dataset (Spearman's correlation coefficient ρ = 0.687, p-value < 0.0001) and the validation dataset (ρ = 0.661, p-value < 0.0001). Lp qPCR positivity thresholds corresponding to culture action thresholds of 10 CFU/L was 91 genome units (GU) per liter (sensitivity, 86.4%; negative predictive value - NPV, 93.3%) and that corresponding to culture action thresholds of 1,000 CFU/L was 1,048 GU/L (sensitivity, 100%; NPV, 100%).

CONCLUSION

Detection of Lp by qPCR could be implemented with confidence in hospitals as a complement to culture in the monitoring strategy to speed up the implementation of corrective measures.

Is cardiac magnetic resonance of additional help in premature ventricular contraction work-up?

Background

Premature ventricular contractions (PVCs) are common in routine medical practice. PVCs are commonly asymptomatic but can also result in palpitations, dyspnea, presyncope or PVC-induced cardiomyopathy that may lead to sudden death. Cardiovascular magnetic resonance (CMR) provides morphological, functional, and tissue characterization in a single setting. CMR imaging proved to reliably identify fibrotic lesions and, hence, has developed into a valuable tool for etiological orientation in patients with PVCs.

Objectives

The aims of this study were: 1) to evaluate which ventricular arrythmia (VA) characteristics predicted CMR abnormalities and 2) the diagnostic yield and the impact in the management of CMR-based imaging versus non-CMR-based imaging in patients referred for PVCs.

Methods

This monocentric retrospective study was conducted in patients with PVCs referred for CMR imaging. Their baseline interview and characteristics, physical examination, surface electrocardiogram (ECG) analysis, ambulatory monitoring, echocardiography and treadmill exercise test data were collected when they were available. The CMR (1,5 T and 3.0 T) protocol included cine imaging and late gadolinium enhancement (LGE) using standard cardiac geometries.

Results

We analyzed 168 patients (65% males, mean age 54.2±16.8 years) referred to our center for PVCs over a two-year period. CMR reported abnormal findings in 73 patients (43.5%) with the diagnosis of structural heart disease (SHD) in 46 patients (27.4%). Left-ventricular late gadolinium-enhancement was documented in 43 patients with abnormal CMR. Using a multivariate analysis, age (p=0.026), sustained ventricular tachycardia (p=0.002) and presence of cardiomyopathy on echocardiography (p&lt;0.001) significantly predicted the presence of abnormal findings on CMR. Compared to non-CMR-based imaging, CMR had a diagnostic yield, by modifying the presumed diagnosis or by finding abnormalities requiring follow-up in 73 patients (43.5%).

Conclusions

Age, sustained ventricular tachycardia and presence of cardiomyopathy on echocardiography were the strongest predictors of positive CMR imaging results. Although echocardiography is generally used in first intention for the diagnosis of cardiomyopathy in patients with PVCs, this study showed that CMR-based imaging has a robust diagnostic yield in this indication.

Funding Acknowledgement

Type of funding sources: None.

Variability in the indication of brain CT scan after mild traumatic brain injury. A transnational survey

PURPOSE

Clinical guidelines have been developed to standardize the management of mild traumatic brain injury (mTBI) in the emergency room, in particular the indication of brain CT scan and the use of blood biomarkers. The objective of this study was to determine the degree of adherence to guidelines in the management of these patients across four countries of Southern Europe.

METHODS

An electronic survey including structural and general management of mTBI patients and six clinical vignettes was conducted. In-charge physicians from France, Spain, Greece and Portugal were contacted by telephone and email. Differences among countries were searched using an unconditional approach test on contingency tables.

RESULTS

One hundred and eighty eight physicians from 131 Hospitals (78 Spain, 36 France, 12 Greece and 5 Portugal) completed the questionnaire. There were differences regarding the in-charge specialist across these countries. There was variability in the use of guidelines and their adherence. Spain was the country with the least guideline adherence. There was a global agreement in ordering a brain CT for patients receiving anticoagulation or platelet inhibitors, and for patients with seizures, altered consciousness, neurological deficit, clinical signs of skull fracture or signs of facial fracture. Aging was not an indication for CT in French centres. Loss of consciousness and posttraumatic amnesia were considered as indications for CT more frequently in Spain than in France. These findings were in line with the data from the 6 clinical vignettes. The estimated use of CT reached around 50% of mTBI cases. The use of S100B is restricted to five French centres.

CONCLUSIONS

There were large variations in the guideline adherence, especially in the situations considered to order brain CT after mTBI.

Unusual cause of obstructive shock following esophagectomy: a case report

Obstructive shock usually has an intrathoracic origin, such as pneumothorax, pericardial tamponade or pulmonary embolism. We report a case of hemo- dynamic shock in a 74-year-old patient four days after esophagectomy, just after the start of mechanical ventilation for bilateral pneumonia. The sudden onset of severe abdominal distension and the presence of air in the intra-abdominal drain suggested tension pneumoperitoneum, confirmed by radiography. No pneumothorax was associated. Urgent decompression was required to improve hemodynamics. Perforation of the gastrointestinal tract was ruled out. The cause was a bronchopleural fistula opened by mechanical ventilation. Rarely, cardiorespiratory failure may occur after tension pneumoperitoneum by reducing lung volume and cardiac preload, similar to obstructive shock from the usual intrathoracic causes or acting as an abdominal compartment syndrome (ACS). Its recognition and abdominal decompression are key steps in the patient’s recovery. Tension pneumoperitoneum related to mechanical ventilation and airway injury without associated pneumothorax is exceptional and, to our knowledge, has never been reported as a postoperative complication of esophagectomy.

Identification of TB space-time clusters and hotspots in Ouest département, Haiti, 2011-2016

BACKGROUND

Haiti has the highest incidence rate of TB in the Western Hemisphere, with an estimated 170 cases per 100,000 in 2019. Since 2010, control efforts have focused on targeted case-finding activities in urban areas, implementation of rapid molecular diagnostics at high-volume TB centers, and improved reporting. TB analyses are rarely focused on lower geographic units; thus, the major goal was to determine if there were focal areas of TB transmission from 2011 to 2016 at operational geographic levels useful for the National TB Control Program (PNLT).

METHODS

We created a geocoder to locate TB cases at the smallest geographic level. Kulldorff's space-time permutation scan, Anselin Moran's I, and Getis-Ord Gi* statistics were used to determine the spatial distribution and clusters of TB.

RESULTS

With 91% of cases linked using the geocoder, TB clusters were identified each year. Getis-Ord Gi* analysis revealed 14 distinct spatial clusters of high incidences in the Port-au-Prince metropolitan area. One hundred retrospective space-time clusters were detected.

CONCLUSION

Our study confirms the presence of TB hotspots in the Ouest département, with most clusters in the Port-au-Prince metropolitan area. Results will help the PNLT and its partners better design case-finding strategies for these areas.

Role of Adult-Born Versus Preexisting Neurons Born at P0 in Olfactory Perception in a Complex Olfactory Environment in Mice

Olfactory perceptual learning is defined as an improvement in the discrimination of perceptually close odorants after passive exposure to these odorants. In mice, simple olfactory perceptual learning involving the discrimination of two odorants depends on an increased number of adult-born neurons in the olfactory bulb, which refines the bulbar output. However, the olfactory environment is complex, raising the question of the adjustment of the bulbar network to multiple discrimination challenges. Perceptual learning of 1 to 6 pairs of similar odorants led to discrimination of all learned odor pairs. Increasing complexity did not increase adult-born neuron survival but enhanced the number of adult-born neurons responding to learned odorants and their spine density. Moreover, only complex learning induced morphological changes in neurons of the granule cell layer born during the first day of life (P0). Selective optogenetic inactivation of either population confirmed functional involvement of adult-born neurons regardless of the enrichment complexity, while preexisting neurons were required for complex discrimination only.

Neural processing of the reward value of pleasant odorants

Pleasant odorants are represented in the posterior olfactory bulb (pOB) in mice. How does this hedonic information generate odor-motivated behaviors? Using optogenetics, we report here that stimulating the representation of pleasant odorants in a sensory structure, the pOB, can be rewarding, self-motivating, and is accompanied by ventral tegmental area activation. To explore the underlying neural circuitry downstream of the olfactory bulb (OB), we use 3D high-resolution imaging and optogenetics and determine that the pOB preferentially projects to the olfactory tubercle, whose increased activity is related to odorant attraction. We further show that attractive odorants act as reinforcers in dopamine-dependent place preference learning. Finally, we extend those findings to humans, who exhibit place preference learning and an increase BOLD signal in the olfactory tubercle in response to attractive odorants. Thus, strong and persistent attraction induced by some odorants is due to a direct gateway from the pOB to the reward system.

In situ characterisation of pathogen dynamics during a Pacific oyster mortality syndrome episode

Significant mortality of Crassostrea gigas juveniles is observed systematically every year worldwide. Pacific Oyster Mortality Syndrome (POMS) is caused by Ostreid Herpesvirus 1 (OsHV-1) infection leading to immune suppression, followed by bacteraemia caused by a consortium of opportunistic bacteria. Using an in-situ approach and pelagic chambers, our aim in this study was to identify pathogen dynamics in oyster flesh and in the water column during the course of a mortality episode in the Mediterranean Thau lagoon (France). OsHV-1 concentrations in oyster flesh increased before the first clinical symptoms of the disease appeared, reached maximum concentrations during the moribund phase and the mortality peak. The structure of the bacterial community associated with oyster flesh changed in favour of bacterial genera previously associated with oyster mortality including Vibrio, Arcobacter, Psychrobium, and Psychrilyobacter. During the oyster mortality episode, releases of OsHV-1 and opportunistic bacteria were observed, in succession, in the water surrounding the oyster lanterns. These releases may favour the spread of disease within oyster farms and potentially impact other marine species, thereby reducing marine biodiversity in shellfish farming areas.

Study protocol for investigating the performance of an automated blood test measuring GFAP and UCH-L1 in a prospective observational cohort of patients with mild traumatic brain injury: European BRAINI study

INTRODUCTION

Mild traumatic brain injury (mTBI) is a common cause of clinical consultation in the emergency department. Patients with mTBI may undergo brain CT scans based on clinical criteria. However, the proportion of patients with brain lesions on CT is very low. Two serum biomarkers, glial fibrillar acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), have been shown to discriminate patients regarding the presence or absence of brain lesions on initial CT scan when assessed within the first 12 hours after TBI. However, the current technique for measuring serum concentrations of GFAP and UCH-L1 is manual and time consuming, which may hinder its use in routine clinical practice. This study assesses the diagnostic accuracy of an automated assay for the measurement of serum GFAP and UCH-L1 in a cohort of patients with mTBI who received a CT scan as the standard of care.

METHODS AND ANALYSIS

This is a prospective multicentre observational study of 1760 patients with mTBI recruited in France and Spain across 16 participating sites. Adult patients with an initial Glasgow Coma Scale score of 13-15 and a brain CT scan underwent blood sampling within 12 hours after TBI. The primary outcome measure is the diagnostic performance of an automated assay measuring serum concentrations of GFAP and UCH-L1 for discriminating between patients with positive and negative findings on brain CT-scans. Secondary outcome measures include the performance of these two biomarkers in predicting the neurological status and quality of life at 1 week and 3 months after the trauma.

ETHICS AND DISSEMINATION

Ethics approval was obtained by the Institutional Review Board of Sud-Ouest Outre Mer III in France (Re#2019-A01525-52) and Hospital 12 de Octubre in Spain (Re#19/322). The results will be presented at scientific meetings and published in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT04032509.

High Prevalence of Human-Associated Escherichia coli in Wetlands Located in Eastern France

Escherichia coli that are present in the rivers are mostly brought by human and animal feces. Contamination occurs mostly through wastewater treatment plant (WWTP) outflows and field amendment with sewage sludge or manure. However, the survival of these isolates in river-associated wetlands remains unknown. Here, we assessed E. coli population structure in low-anthropized wetlands located along three floodplains to identify the major source of contamination of wetlands, whose functioning is different from the rivers. We retrieved 179 E. coli in water samples collected monthly from 19 sites located in eastern France over 1 year. Phylogroups B1 and B2 were dominant in the E. coli population, while phylogroup A was dominant in isolates resistant to third-generation cephalosporins, which harbored the extended-spectrum β-lactamase (ESBL) encoding genes bla_CTX–M–15 and bla_CTX–M–27 in half of the cases. The high proportion of isolates from human source can be attributed to WWTP outflows and the spread of sewage sludge. We analyzed the distribution of the isolates belonging to the most human-associated phylogroups (B2 and D) on a phylogenetic tree of the whole species and compared it with that of isolates retrieved from patients and from WWTP outflows. The distribution of the three E. coli populations was similar, suggesting the absence of a specific population in the environment. Our results suggest that a high proportion of E. coli isolates that reach and survive in low-anthropized environments such as wetlands are from human source. To the best of our knowledge, this is the first study assessing E. coli contamination and resistance genes in natural freshwater wetlands.

Introducing new and repurposed TB drugs: the endTB experience

In 2015, the initiative Expand New Drug Markets for TB (endTB) began, with the objective of reducing barriers to access to the new and repurposed TB drugs. Here we describe the major implementation challenges encountered in 17 endTB countries. We provide insights on how national TB programmes and other stakeholders can scale-up the programmatic use of new and repurposed TB drugs, while building scientific evidence about their safety and efficacy. For any new drug or diagnostic, multiple market barriers can slow the pace of scale-up. During 2015-2019, endTB was successful in increasing the number of patients receiving new and repurposed TB drugs in 17 countries. The endTB experience has many lessons, which are relevant to country level introduction of new TB drugs, as well as non-TB drugs and diagnostics. For example: the importation of TB drugs is possible even in the absence of registration; emphasis on good clinical monitoring is more important than pharmacovigilance reporting; national guidelines and expert committees can both facilitate and hinder innovative practice; clinicians use new and repurposed TB drugs when they are available; data collection to generate scientific evidence requires financial and human resources; pilot projects can drive national scale-up.

Producing three-dimensional printed models of the hepatobiliary system from computed tomography imaging data

INTRODUCTION

Macroscopic anatomy has traditionally been taught using cadaveric material, lectures and a variety of additional resources including online modules and anatomical models. Traditional plastic models are effective educational tools yet they have significant drawbacks such as a lack of anatomical detail, a lack of texturisation and cost. Three-dimensional printed models stand to solve these problems and widen access to high-quality anatomical teaching. This paper outlines the use of three-dimensional multiplanar imaging (computed tomography) in the development of an accurate model of the hepatobiliary system.

MATERIALS AND METHODS

Computed tomography scans were used to construct a virtual three-dimensional model of the hepatobiliary system. This was printed locally as a full-size colour model. We give a complete account of the process and software used.

DISCUSSION

This study is among the first of a series in which we will document the newly formed Oxford Library of Anatomy. This series will provide the methodology for the production of three-dimensional models from computed tomography and magnetic resonance imaging scans, and the library will provide a complete collection of the most complex anatomical areas. We hope that these models will form an important adjunct in teaching anatomy to medical students and surgical trainees.

Fifty years of ecological changes: Regime shifts and drivers in a coastal Mediterranean lagoon during oligotrophication

Thau lagoon is a large Mediterranean coastal lagoons and it supports traditional shellfish farming activities. It has been subject to eutrophication leading to major anoxic events associated with massive mortalities of shellfish stocks. Since the 1970s, improvements have been made to wastewater treatment systems, which have gradually led to oligotrophication of the lagoon. The aim of our study was to determine how the decrease in nutrient inputs resulted in major ecological changes in Thau lagoon, by analysing five decades of time-series (1970-2018) of observations on pelagic and benthic autotrophic communities. We were able to identify two periods during the oligotrophication process. Period 1 (1970-1992) was considered a eutrophic period, characterised by the shift from seagrass dominance to dominance of red macroalgae. Period 2 (1993-2018), characterised by improved eutrophication status, was further divided into three: a transition phase (1993-2003) during which the water column continued to recover but the benthic community lagged behind in recovery and in partial resilience; a regime shift (2003-2006), after which the water column became oligotrophic and seagrass began to recover (2007-2018). Considering anoxia crises as indicators of ecosystem resilience and resistance, we used a generalised linear model to analyse meteorological and environmental data with the aim of identifying the triggers of summer anoxia over the study period. Among the meteorological variables studied, air temperature had the strongest positive effect, followed by the period and wind intensity (both negative effects) and by rainfall in July (positive effect). The risk of triggering anoxia was lower in period 2, evidence for the increasing resistance of the ecosystem to climatic stress throughout the oligotrophication process. At the ecosystem scale and in the long term perspective, the ecological gains related to oligotrophication are especially important in the context of climate change, with more frequent and severe heat waves predicted.

Comparison of strategies for monitoring and treating patients at the early phase of severe traumatic brain injury: the multicentre randomised controlled OXY-TC trial study protocol

INTRODUCTION

Intracranial hypertension is considered as an independent risk factor of mortality and neurological disabilities after severe traumatic brain injury (TBI). However, clinical studies have demonstrated that episodes of brain ischaemia/hypoxia are common despite normalisation of intracranial pressure (ICP). This study assesses the impact on neurological outcome of guiding therapeutic strategies based on the monitoring of both brain tissue oxygenation pressure (PbtO₂) and ICP during the first 5 days following severe TBI.

METHODS AND ANALYSIS

Multicentre, open-labelled, randomised controlled superiority trial with two parallel groups in 300 patients with severe TBI. Intracerebral monitoring must be in place within the first 16 hours post-trauma. Patients are randomly assigned to the ICP group or to the ICP + PbtO₂ group. The ICP group is managed according to the international guidelines to maintain ICP≤20 mm Hg. The ICP + PbtO₂ group is managed to maintain PbtO₂ ≥20 mm Hg in addition to the conventional optimisation of ICP. The primary outcome measure is the neurological status at 6 months as assessed using the extended Glasgow Outcome Scale. Secondary outcome measures include quality-of-life assessment, mortality rate, therapeutic intensity and incidence of critical events during the first 5 days. Analysis will be performed according to the intention-to-treat principle and full statistical analysis plan developed prior to database freeze.

ETHICS AND DISSEMINATION

This study has been approved by the Institutional Review Board of Sud-Est V (14-CHUG-48) and from the National Agency for Medicines and Health Products Safety (Agence Nationale de Sécurité du Médicament et des produits de santé) (141 435B-31). Results will be presented at scientific meetings and published in peer-reviewed publications.The study was registered with ClinTrials NCT02754063 on 28 April 2016 (pre-results).

Feasibility of the single-incision subxiphoid approach for video-assisted thoracoscopic surgery in dogs

OBJECTIVES

To report early results of uniportal video-assisted thoracoscopic surgery in dogs using a single-incision subxiphoid approach.

MATERIALS AND METHODS

Retrospective study of 10 client-owned dogs with: pyothorax (n=5), pericardial effusion (n=2), bilateral pneumothorax (n=1), retained surgical swab (n=1), cranial mediastinal mass (n=1). With the dog in dorsal recumbency a 3-4 cm incision was made over the xiphoid process. After resection of the xiphoid process, a tunnel was created towards the pleura and open access maintained with an Alexis™ wound retractor. The pleural cavity was explored with a 10 mm 30° or 5 mm 0° telescope and straight laparoscopic instruments.

RESULTS

Median surgical time was 75 minutes. The SISA technique was performed successfully in five of 10 cases and allowed easy and adequate inspection of the intra-thoracic structures. One case was converted to lateral thoracotomy after laceration of the vena cava and one converted to median sternotomy because of adhesions. An additional port was placed in three cases to facilitate triangulation and surgical manipulation. No other intra-operative complications were encountered.

CLINICAL SIGNIFICANCE

In this initial report of uniportal thoracic approach in dogs, this technique allowed excellent access and treatment of mediastinal structures. Further cases are required to assess its suitability for pulmonary surgery.

Post-natal co-development of the microbiota and gut barrier function follows different paths in the small and large intestine in piglets

Gut microbiota and intestinal barrier co-develop after birth, establishing a homeostatic state whereby mucosal cells cohabit with commensal bacteria. We hypothesized that this post-natal co-development follows different timings depending on the intestinal site considered. Jejunal, ileal, and colonic luminal contents and mucosa were sampled in suckling piglets at post-natal day (PND) 0, 2, 7, 14, and 28. Jejunal, ileal, and colonic luminal microbiota (evaluated by 16S DNA sequencing followed by beta-diversity analysis) clustered at PND2 but colonic microbiota diverge afterwards (P < .05). Mucosal permeability, evaluated in Ussing chambers, increased with age in the jejunum and ileum (P < .05) but not the colon. Expression of pattern recognition receptor (PRR) exhibited different patterns (gradual or sharp increase, decrease, or no change with age, P < .05) depending on PRR and intestinal site considered. Principal component analysis of mucosa data revealed clear clustering of colonic samples, irrespective of the age and clustering of jejunal and ileal samples, with gradual changes with age. Correlation analysis highlighted three families correlating with mucosal parameters: Enterobacteriaceae in the jejunum, Peptostreptococcaceae in the ileum, and Micrococcaceae in the colon. In conclusion, small and large intestine display close microbiota composition early in life but distinct mucosal phenotype and follow very different post-natal development.

Enhanced emergence of antibiotic-resistant pathogenic bacteria after in vitro induction with cancer chemotherapy drugs

BACKGROUND

Infections with antibiotic-resistant pathogens in cancer patients are a leading cause of mortality. Cancer patients are treated with compounds that can damage bacterial DNA, potentially triggering the SOS response, which in turn enhances the bacterial mutation rate. Antibiotic resistance readily occurs after mutation of bacterial core genes. Thus, we tested whether cancer chemotherapy drugs enhance the emergence of resistant mutants in commensal bacteria.

METHODS

Induction of the SOS response was tested after the incubation of Escherichia coli biosensors with 39 chemotherapeutic drugs at therapeutic concentrations. The mutation frequency was assessed after induction with the SOS-inducing chemotherapeutic drugs. We then tested the ability of the three most highly inducing drugs to drive the emergence of resistant mutants of major bacterial pathogens to first-line antibiotics.

RESULTS

Ten chemotherapeutic drugs activated the SOS response. Among them, eight accelerated the evolution of the major commensal E. coli, mostly through activation of the SOS response, with dacarbazine, azacitidine and streptozotocin enhancing the mutation rate 21.3-fold (P < 0.001), 101.7-fold (P = 0.01) and 1158.7-fold (P = 0.02), respectively. These three compounds also spurred the emergence of imipenem-resistant Pseudomonas aeruginosa (up to 6.21-fold; P = 0.05), ciprofloxacin-resistant Staphylococcus aureus (up to 57.72-fold; P = 0.016) and cefotaxime-resistant Enterobacteria cloacae (up to 4.57-fold; P = 0.018).

CONCLUSIONS

Our results suggest that chemotherapy could accelerate evolution of the microbiota and drive the emergence of antibiotic-resistant mutants from bacterial commensals in patients. This reveals an additional level of complexity of the interactions between cancer, chemotherapy and the gut microbiota.

Loss to follow-up among patients receiving anti-tuberculosis treatment, Haiti, 2011-2015

Setting: Tuberculosis (TB) treatment facilities in Haiti. Objective: To assess factors associated with loss to follow-up (LTFU) among patients receiving treatment for tuberculosis (TB) in Haiti. Design: We analyzed Haiti's national surveillance data for patients started on anti-tuberculosis treatment from 2011 to 2015 to determine factors associated with LTFU using multivariable logistic regression and describe LTFU in terms of subnational units to target future intervention strategies. We also conducted a survival analysis to estimate hazard ratios of factors associated with time to LTFU. Results: Of 81 490 TB cases reported, 7423 (9.1%) were LTFU during anti-tuberculosis treatment, increasing from 7.1% in 2011 to 10.3% in 2015. Six high-volume facilities had significantly higher rates of LTFU (14.3-31.9%) than the rest of the country, accounting for 18.8% of all TB cases reported, but 41.7% of all LTFU patients. Male sex, previous treatment history, and human immunodeficiency virus infection were associated with higher rates of LTFU. The median time to LTFU was 94 days. Conclusion: A small number of facilities accounted for disproportionately high rates of LTFU. These results identify characteristics of facilities and individuals leading to concentrated interventions to reduce LTFU and improve treatment success.

Body size and temperature effects on standard metabolic rate for determining metabolic scope for activity of the polychaete Hediste (Nereis) diversicolor

Considering the ecological importance and potential value of Hediste diversicolor, a better understanding of its metabolic rate and potential growth rates is required. The aims of this study are: (i) to describe key biometric relationships; (ii) to test the effects of temperature and body size on standard metabolic rate (as measure by oxygen consumption) to determine critical parameters, namely Arrhenius temperature (T_A ), allometric coefficient (b) and reaction rate; and (iii) to determine the metabolic scope for activity (MSA) of H. diversicolor for further comparison with published specific growth rates. Individuals were collected in a Mediterranean lagoon (France). After 10 days of acclimatization, 7 days at a fixed temperature and 24 h of fasting, resting oxygen consumption rates (VO₂ ) were individually measured in the dark at four different temperatures (11, 17, 22 and 27 °C) in worms weighing from 4 to 94 mgDW (n = 27 per temperature). Results showed that DW and L3 were the most accurate measurements of weight and length, respectively, among all the metrics tested. Conversion of WW (mg), DW (mg) and L3 (mm) were quantified with the following equations: DW = 0.15 × WW, L3 = 0.025 × TL(mm) + 1.44 and DW = 0.8 × L3^3.68. Using an equation based on temperature and allometric effects, the allometric coefficient (b) was estimated at 0.8 for DW and at 2.83 for L3. The reaction rate (VO₂ ) equaled to 12.33 µmol gDW^-1 h^-1 and 0.05 µmol mm L3^-1 h^-1 at the reference temperature (20 °C, 293.15 K). Arrhenius temperature (T_A ) was 5,707 and 5,664 K (for DW and L3, respectively). Metabolic scope for activity ranged from 120.1 to 627.6 J gDW^-1 d^-1. Predicted maximum growth rate increased with temperature, with expected values of 7-10% in the range of 15-20 °C. MSA was then used to evaluate specific growth rates (SGR) in several experiments. This paper may be used as a reference and could have interesting applications in the fields of aquaculture, ecology and biogeochemical processes.

Opposite regulation of inhibition by adult-born granule cells during implicit versus explicit olfactory learning

Both passive exposure and active learning through reinforcement enhance fine sensory discrimination abilities. In the olfactory system, this enhancement is thought to occur partially through the integration of adult-born inhibitory interneurons resulting in a refinement of the representation of overlapping odorants. Here, we identify in mice a novel and unexpected dissociation between passive and active learning at the level of adult-born granule cells. Specifically, while both passive and active learning processes augment neurogenesis, adult-born cells differ in their morphology, functional coupling and thus their impact on olfactory bulb output. Morphological analysis, optogenetic stimulation of adult-born neurons and mitral cell recordings revealed that passive learning induces increased inhibitory action by adult-born neurons, probably resulting in more sparse and thus less overlapping odor representations. Conversely, after active learning inhibitory action is found to be diminished due to reduced connectivity. In this case, strengthened odor response might underlie enhanced discriminability.

Downregulation of heat shock protein B8 decreases osteogenic differentiation potential of dental pulp stem cells during in vitro proliferation

OBJECTIVES

Tissue-derived stem cells, such as dental pulp stem cells (DPSCs), reduce differentiation capability during in vitro culture. We found that cultured DPSCs reduce expression of heat shock protein B8 (HspB8) and GIPC PDZ domain containing family member 2 (Gipc2). Our objectives were to evaluate the changes in DPSC composition during in vitro proliferation and to determine whether HspB8 and Gipc2 have function in differentiation potential of DPSCs.

MATERIALS AND METHODS

Different passages of rat DPSCs were evaluated for changes in CD90+ and/or CD271+ stem cells and changes in osteogenic potential. Real-time RT-PCR and immunostaining were conducted to determine expression of HspB8 and Gipc2. Expression of the genes in DPSCs was knocked down by siRNA, followed by osteogenic induction to evaluate the function of the genes.

RESULTS

About 90% of cells in the DPSC cultures were CD90+ and/or CD271+ cells without dramatic change during in vitro proliferation. The DPSCs at passages 3 to 5 (P3 to P5) possess strong osteogenic potential, but such potential was greatly reduced at later passages. Expression of HspB8 and Gipc2 was significantly reduced at P11 versus P3. Knock-down of HspB8 expression abolished osteogenic potential of the DPSCs, but knock-down of Gipc2 had no effect.

CONCLUSIONS

CD90+ and CD271+ cells are the major components of DPSCs in in vitro culture. High-level expression of HspB8 was critical for maintaining differentiation potential of DPSCs.

Strain-Gradient Position Mapping of Semiconductor Quantum Dots

We introduce a nondestructive method to determine the position of randomly distributed semiconductor quantum dots (QDs) integrated in a solid photonic structure. By setting the structure in an oscillating motion, we generate a large stress gradient across the QDs plane. We then exploit the fact that the QDs emission frequency is highly sensitive to the local material stress to map the position of QDs deeply embedded in a photonic wire antenna with an accuracy ranging from ±35  nm down to ±1  nm. In the context of fast developing quantum technologies, this technique can be generalized to different photonic nanostructures embedding any stress-sensitive quantum emitters.

From Patient Discharge Summaries to an Ontology for Psychiatry

Psychiatry aims at detecting symptoms, providing diagnoses and treating mental disorders. We developed ONTOPSYCHIA, an ontology for psychiatry in three modules: social and environmental factors of mental disorders, mental disorders, and treatments. The use of ONTOPSYCHIA, associated with dedicated tools, will facilitate semantic research in Patient Discharge Summaries (PDS). To develop the first module of the ontology we propose a PDS text analysis in order to explicit psychiatry concepts. We decided to set aside classifications during the construction of the modu le, to focus only on the information contained in PDS (bottom-up approach) and to return to domain classifications solely for the enrichment phase (top-down approach). Then, we focused our work on the development of the LOVMI methodology (Les Ontologies Validées par Méthode Interactive - Ontologies Validated by Interactive Method), which aims to provide a methodological framework to validate the structure and the semantic of an ontology.

Limit theorems for supercritical age-dependent branching processes with neutral immigration

We consider a branching process with Poissonian immigration where individuals have inheritable types. At rate θ, new individuals singly enter the total population and start a new population which evolves like a supercritical, homogeneous, binary Crump-Mode-Jagers process: individuals have independent and identically distributed lifetime durations (nonnecessarily exponential) during which they give birth independently at a constant rateb. First, using spine decomposition, we relax previously known assumptions required for almost-sure convergence of the total population size. Then, we consider three models of structured populations: either all immigrants have a different type, or types are drawn in a discrete spectrum or in a continuous spectrum. In each model, the vector (P1,P2,…) of relative abundances of surviving families converges almost surely. In the first model, the limit is the GEM distribution with parameter θ /b.

Toward evidence-based medical statistics: Re-evaluate the efficacy of antidepressants by using Bayes factors

Introduction

Studies have been reported the similar efficacy of antidepressants (effect size around 0.3), and it is difficult for clinicians to select an antidepressant. This may partly due to the use of a p<.05 null-hypothesis significance testing (NHST) framework to evaluate “substantial evidence”. This framework only allows dichotomous conclusions and does not quantify the strength of evidence supporting efficacy. In addition, meta-analyses based on publications may offer positively biased results due to selective publications.

Objectives

Demonstrate that the Bayesian framework can provide valuable information on the strength of the evidence for drug efficacy.

Aims

Re-evaluate the efficacy of FDA-approved antidepressants applied to anxiety disorders and depression by means of Bayes factors.

Methods

To avoid selective publication, data of double-blind placebo-controlled trials for FDA-approved antidepressants for the treatment of anxiety disorders and depression were extracted from the FDA. Bayes factors (BFs) were calculated and compared with the results obtained under NHST framework.

Results

A large variance of evidence for the efficacy of antidepressants was found for both depression and anxiety disorders. Among trials providing “substantial evidence” according to the FDA for anxiety disorders, only 27 out of 59 dose groups obtained strong support for efficacy according to the typically used cut-off of BF≥20. For depression, all FDA-approved antidepressants had BF≥20, except for bupriopion. Moreover, it was shown that the tested antidepressants can be differentiated based on the strength of evidence and effect size.

Conclusions

The BFs quantified the comparative evidence base for the efficacy of antidepressants.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Evaluation by obstetric care providers of simulated postpartum blood loss using a collector bag: a French prospective study

OBJECTIVE

Postpartum hemorrhage (PPH) is one of the most common causes of mortality in obstetrics worldwide. Accuracy in the estimated blood loss is a priority in determining appropriate treatment. The aim of this study was to evaluate the accuracy of estimating blood loss by obstetrics care providers during simulated training sessions.

METHOD

A prospective study occurred in 2013 in a maternity ward at a teaching hospital. Simulation training sessions recreated a vaginal delivery in which six different scenarios were presented and proposed to each participant for them to estimate the blood loss (from 350 ml to 2500 ml) while using a collector bag graduated every 100 ml from 0 ml to 1500 ml. The primary endpoint was to determine if participants could accurately evaluate blood loss within a 20% error margin.

RESULTS

About 90.7% of the medical staff participated. Ninety-three to 98% of the participants were accurate in their answer depending on which volume they had to estimate. For the lowest volume (350 ml), there was 11.1% overestimation between the estimated volume of blood loss (EBV) and the real volume of blood loss (RBV). However, there was an 8.8% underestimation found for the highest volume.

CONCLUSION

The accuracy of the estimated blood loss for the obstetrical medical staff, using the collector bag, is more than 96%.

Effect of crude oil exposure and dispersant application on meiofauna: an intertidal mesocosm experiment

Dispersant application is used as a response technique to minimize the environmental risk of an oil spill. In nearshore areas, dispersant application is a controversial countermeasure: environmental benefits are counteracted by the toxicity of dispersant use. The effects of the use of chemical dispersants on meiobenthic organisms and nematodes were investigated in a mesocosm experiment. A 20 day experiment was performed in four experimental sets of mesocosms. In three of them, sediments were contaminated, respectively by oil (500 mg kg(-1)), dispersed oil (oil + 5% dispersant), and dispersant alone, whereas in the last set sediments were kept undisturbed and used as a reference (Re). Our results showed that the meiobenthic response to oil contamination was rapid, for copepods and nematodes. One-way ANOVA showed a significant decrease of the abundance of copepods. In the case of nematodes, univariate and multivariate analyses indicated a clear decrease of the abundance of the species after only 20 days of pollutant exposure and thus reducing Shannon-Wiener diversity and Pielou's evenness. In contrast, Sphaerolaimus gracilis and Sabateria sp. became more frequent within disturbed assemblages and appeared to be resistant and/or opportunistic species in the presence of these kinds of toxicants. Moreover, responses of copepods and nematodes to the treatment seemed to be the same irrespective of whether only oil or oil + dispersant was performed. The main toxicities of dispersed oil come not from the "composition of a newly formed oil and oil spill dispersant mixture" but from the "quantities of increased dispersed oil droplets".