Patient satisfaction after distal upper limb surgery under WALANT versus axillary block: A propensity-matched comparative cohort study

Distal upper limb surgery is performed under WALANT (Wide Awake Local Anesthesia No Tourniquet) in many outpatient centers because the benefits are numerous: simple, low-cost technique, with fast turnover and short length of stay. In view of a paucity of data concerning patient satisfaction, this non-randomized cohort study was designed to compare EVAN-LR anesthesia satisfaction questionnaire results (information, pain, expectation, attention, discomfort: 0-100 points) between patients receiving WALANT or axillary nerve block (AxB). After IRB approval, patients (>18 years, stable ASA 1-3) scheduled for outpatient distal upper limb surgery were prospectively enrolled in the two groups. At discharge, patients in both groups received standard information on postoperative recovery and care, with a multimodal analgesic regime (acetaminophen and ketoprofen for 5 days). The primary endpoint was EVAN-LR score before discharge. Secondary endpoints were pain relief and side-effects over a 7-day period. Results were recorded as median and 25-75% interquartile range. Propensity-score-matched analysis was performed. Over the study period, from October 2019 to November 2020, 183 patients were included; 48 WALANT patients were propensity-score matched to 48 AxB patients. Pre-procedural APAIS anxiety score was lower in the WALANT than the AxB group: 9 (IQR, 6-12) vs 12 (IQR, 8-14) (p = 0.01). EVAN-LR scores were similar between the WALANT (78 [72-82]) and the AxB group (73 [67-80]). Incidences of paresthesia and of pain (NRS pain score, opioid rescue) were similar. WALANT patients had shorter length of stay: 135 (110-175) min vs 170 (110-250) min (p = 0.01). The present study demonstrated that WALANT was associated with a high level of patient satisfaction. For clinical relevance and quality of care, WALANT should be proposed in first line for distal limb surgery.

P15.07.A Predicting sites of local tumour progression - what should be our imaging biomarker?

Background

Glioblastoma is the most aggressive primary brain tumour diagnosed in adults. Despite intensive treatment of maximal safe resection and chemoradiotherapy, the prognosis remains grim due to invasive tumour cells. Current treatment and standard imaging methods are highly limited in terms of managing these invasive cells as they are often located outside the area of surgical resection and are generally resistant to chemoradiation. DTI appears to be a promising tool for imaging tumour cell invasion and predicting the site of recurrence especially when decomposed into its anisotropic (q) and isotropic (p) components. The aim of this study is to investigate the sensitivity of imaging biomarkers as predictors of recurrence.

Material and Methods

All pre-op and recurrence sequences were co-registered to the pre-op post-contrast T1-weighted images as reference. Co-registration of images was performed using FSL and ANTs. The ROIs for 49 patients with a primary diagnosis of GBM were segmented using 3DSlicer. Each voxel was assigned to one of four status: true negative, false negative, true positive and false positive. Sensitivity and specificity between the pre-op ROIs and the progression region were calculated using FSL. The significance of the differences in sensitivity and specificity between the ROIs was computed in MATLAB.

Results

The sensitivity for the contrast enhancing region was 48.77 ± 26.13 (Mean ± SD) and 62.40 ± 23.07 (Mean ± SD). The abnormal q alone has a significantly greater sensitivity than the contrast enhancing region (t = -2.7327, df = 96, p-value = 0.0075). The sensitivity for the ROI of combined contrast enhancement and abnormal q was 65.86 ± 23.29 (Mean ± SD). There is an even more significant increase in sensitivity when the contrast enhancing ROI is combined with abnormal q region (t = -3.4133, df = 96, p-value = 9.4123e-04) compared to when it is alone. There was no statistical difference in the specificities of the different ROIs.

Conclusion

Current surgical and radiation volumes focus solely on pre-op contrast enhancement. However, these results suggest that combining the abnormal q with the standard contrast enhancing region is a more sensitive predictor of tumour recurrence than contrast enhancement alone, while still retaining high specificity. The higher sensitivity is an indicator of correct identification of tumour recurrence while the high specificity correctly identifies normal brain, or non-recurrent regions. These results are currently being prospectively assessed in a multi-centre study (PRaM-GBM).

969 Intra-Abdominal Rectal Perforation Post Haemorrhoidal Artery Ligation Operation (HALO) And Converted Ligasure Open Haemorrhoidectomy

Case Report

Symptomatic prolapsing haemorrhoids are usually treated with either haemorrhoidal artery ligation operation (HALO), stapled haemorrhoidopexy or open haemorrhoidectomy. Complications are rare with serious complications like rectal perforation reported scarcely in literature. We report a case of intraperitoneal rectal perforation following transanal haemorrhoidal artery ligation and converted open Ligasure-assisted haemorrhoidectomy in a 74-year-old lady with background portal hypertension secondary to primary biliary cirrhosis. We present this case to highlight the importance of preoperative medical optimisation of portal hypertension prior to surgical intervention and consideration of primary open techniques in grade 4 haemorrhoid surgery.

The novel vasopressin receptor (V1aR) antagonist SRX246 reduces anxiety in an experimental model in humans: a randomized proof-of-concept study

RATIONALE

Arginine vasopressin (AVP) is a neuropeptide that modulates both physiological and emotional responses to threat. Until recently, drugs that target vasopressin receptors (V1a) in the human central nervous system were unavailable. The development of a novel V1a receptor antagonist, SRX246, permits the experimental validation of vasopressin's role in the regulation of anxiety and fear in humans.

OBJECTIVES

Here, we examined the effects of SRX246 in a proof-of-concept translational paradigm of fear (phasic response to imminent threat) and anxiety (prolonged response to potential threat).

METHODS

Healthy volunteers received both SRX246 and placebo in a randomized, double-blind, counter-balanced order separated by a 5-7-day wash-out period. Threat consisted of unpleasant electric shocks. The "NPU" threat test probed startle reactivity during predictable threat (i.e., fear-potentiated startle) and unpredictable threat (i.e., anxiety-potentiated startle).

RESULTS

As predicted, SRX246 decreased anxiety-potentiated startle independent of fear-potentiated startle.

CONCLUSIONS

As anxiety-potentiated startle is elevated in anxiety and trauma-associated disorders and decreased by traditional anxiolytics such as SSRIs and benzodiazepines, the V1a receptor is a promising novel treatment target.

Drug safety profiles in geriatric patients with Parkinson's disease using the FORTA (Fit fOR The Aged) classification: results from a mono-centric retrospective analysis

To reduce potentially inappropriate medications, the FORTA (Fit fOR The Aged) concept classifies drugs in terms of their suitability for geriatric patients with different labels, namely A (indispensable), B (beneficial), C (questionable), and D (avoid). The aims of our study were to assess the medication appropriateness in PD inpatients applying the FORTA list and drug-drug interaction software, further to assess the adequacy of FORTA list for patients with PD. We retrospectively collected demographic data, comorbidities, laboratory values, and the medication from the discharge letters of 123 geriatric inpatients with PD at the university hospital of Hannover Medical School. Patients suffered on average from 8.2 comorbidities. The majority of the medication was labeled A (60.6% of PD-specific and 40.9% of other medication) or B (22.3% of PD-specific and 26.9% of other medication). Administered drugs labeled with D were amantadine, clozapine, oxazepam, lorazepam, amitriptyline, and clonidine. Overall, 545 interactions were identified, thereof 11.9% severe interactions, and 1.7% contraindicated combinations. 81.3% of patients had at least one moderate or severe interaction. The FORTA list gives rational recommendations for PD-specific and other medication, especially for general practitioners. Considering the demographic characteristics and the common multimorbidity of geriatric PD patients, this study underlines the importance of awareness, education, and preventive interventions to increase drug safety.

Internet-delivered cognitive behavioural therapy for post-traumatic stress disorder: systematic review and meta-analysis

OBJECTIVE

To determine whether Internet-delivered cognitive behavioural therapy (i-CBT) is an effective treatment for those who meet diagnostic criteria for post-traumatic stress disorder (PTSD).

METHOD

A systematic review was undertaken according to Cochrane Collaboration Guidelines. The primary outcome measures were reduction in PTSD symptoms and drop-out. Categorical outcomes were meta-analysed as risk ratios (RRs) and continuous outcomes as mean differences (MDs) or standardised mean differences (SMDs).

RESULTS

Ten studies with 720 participants were included. Evidence showed that i-CBT may be associated with a clinically important reduction in post-treatment PTSD symptoms compared with wait list (SMD -0.60, 95% confidence interval -0.97 to -0.24; N = 560); however, only three studies reported follow-up data, and there was no evidence to support the maintenance of symptom improvement at follow-up of 3-6 months. There was no evidence of a difference in PTSD symptoms between i-CBT and Internet-delivered non-CBT post-treatment. There was evidence of greater treatment effect from trauma-focused i-CBT than i-CBT without a trauma focus, as well as evidence that treatment effect was increased by the provision of guidance.

CONCLUSIONS

While the review found some beneficial effects of i-CBT for PTSD post-treatment, the quality of the evidence was very low because of the small number of included trials and there was insufficient evidence to support the maintenance of improvement at follow-up of 3-6 months. Further work is required to establish non-inferiority to current first-line interventions; to determine long-term efficacy; to explore mechanisms of effect; and to establish optimal levels of guidance.

Neuroradiological Changes Following Single or Repetitive Mild TBI

Objectives

To test the hypothesis that there are differences in neuroradiological measures between single and repeated mild traumatic brain injury using multimodal MRI.

Methods

A closed-head momentum exchange model was used to produce one or three mild head injuries in young adult male rats compared to non-injured, age and weight-matched controls. Six-seven weeks post-injury, rats were studied for deficits in cognitive and motor function. Seven-eight weeks post-injury changes in brain anatomy and function were evaluated through analysis of high resolution T2 weighted images, resting-state BOLD functional connectivity, and diffusion weighted imaging with quantitative anisotropy.

Results

Head injuries occurred without skull fracture or signs of intracranial bleeding or contusion. There were no significant differences in cognitive or motors behaviors between experimental groups. With a single mild hit, the affected areas were limited to the caudate/putamen and central amygdala. Rats hit three times showed altered diffusivity in white matter tracts, basal ganglia, central amygdala, brainstem, and cerebellum. Comparing three hits to one hit showed a similar pattern of change underscoring a dose effect of repeated head injury on the brainstem and cerebellum. Disruption of functional connectivity was pronounced with three mild hits. The midbrain dopamine system, hippocampus, and brainstem/cerebellum showed hypoconnectivity. Interestingly, rats exposed to one hit showed enhanced functional connectivity (or hyperconnectivity) across brain sites, particularly between the olfactory system and the cerebellum.

Interpretation

Neuroradiological evidence of altered brain structure and function, particularly in striatal and midbrain dopaminergic areas, persists long after mild repetitive head injury. These changes may serve as biomarkers of neurodegeneration and risk for dementia later in life.

The mir-200 family regulates key pathogenic events in ascending aortas of individuals with bicuspid aortic valves

BACKGROUND

An individual with a bicuspid aortic valve (BAV) runs a substantially higher risk of developing aneurysm in the ascending aorta compared to the normal population with tricuspid aortic valves (TAV). Aneurysm formation in patients with BAV and TAV is known to be distinct at the molecular level but the underlying mechanisms are undefined. Here, we investigated the still incompletely described role of microRNAs (miRNAs), important post-transcriptional regulators of gene expression, in such aortic disease of patients with BAV as compared with TAV.

METHODS AND RESULTS

Using a system biology approach, based on data obtained from proteomic analysis of non-dilated aortas from BAV and TAV patients, we constructed a gene-interaction network of regulatory microRNAs associated with the observed differential protein signature. The miR-200 family was the highest ranked miRNA, hence potentially having the strongest effect on the signalling network associated with BAV. Further, qRT-PCR and ChIP analyses showed lower expression of miR-200c, higher expression of miR-200 target genes, ZEB1/ZEB2 transcription factors, and higher chromatin occupancy of the miR-200c promoter by ZEB1/ZEB2 in BAV patients, indicating a miR-200c/ZEBs negative feedback loop and induction of endothelial/epithelial mesenchymal transition (EndMT/EMT).

CONCLUSION

We propose that a miR-200-dependent process of EndMT/EMT is a plausible biological mechanism rendering the BAV ascending aorta more prone to aneurysm development. Although initially supported by a miR-200c/ZEB feedback loop, this process is most probably advanced by cooperation of other miRNAs.

[Aripiprazole as dopamine partial agonist model: Basic concepts and clinical impact]

Aripiprazole may be viewed as the prototype of third-generation antipsychotics. This concept is based on the notion of D2 partial agonism, whereas all molecules of first-and second generation were D2 antagonists. After reviewing the basic pharmacological notions linked to such concepts, the mechanisms of action of these molecules are addressed, with a particular focus on functional selectivity and biased ligand. One of the essential pharmacological properties of D2 agonists, and particularity aripiprazole, is their ability to not induce D2 supersensitivity as well as to reverse this supersensitivity when it has been induced by D2 antagonists. In clinical practice, this impacts the choice of treatment in first episode psychosis as well as in refractory schizophrenia. Animal research shows that D2 supersensitivity could contribute to worsen addictive trends. The pharmacokinetic incidence of D2 supersensitivity tends to favour the long-acting forms of partial agonists. The notion of partial agonism could finally lead to design fourth-generation antipsychotics, on the basis on research focusing on functional selectivity.

A new pharmacokinetic model for 90Y-ibritumomab tiuxetan based on 3-dimensional dosimetry

Monoclonal antibodies (mAbs) are key components in several therapies for cancer and inflammatory diseases but current knowledge of their clinical pharmacokinetics and distribution in human tissues remains incomplete. Consequently, optimal dosing and scheduling in clinics are affected. With sequential radiolabeled mAb-based imaging, radiation dosing in tissues/organs can be calculated to provide a better assessment of mAb concentrations in tissues. This is the first pharmacokinetic model of ⁹⁰Y-Ibritumomab tiuxetan (⁹⁰Y-IT) in humans to be described, based on three-dimensional (3D) dosimetry using single-photon emission computed-tomography coupled with computed-tomography. 19 patients with follicular lymphoma were treated initially with ⁹⁰Y-IT in the FIZZ trial. Based on a compartmental approach individualising the vascular compartment within studied organs, this study proposes a reliable pharmacokinetic (PK) five-compartment model replacing the currently used two-compartment model and constitutes a new direction for further research. This model provides exchange constants between the different tissues, Area Under the Curve of ¹¹¹In-IT in blood (AUC) and Mean Residence Time (MRT) that have not been reported so far for IT. Finally, the elimination process appears to occur in a compartment other than the liver or the spleen and suggests the metabolism of mAbs may take place mainly on the vascular compartment level.

Use of a Computer for Compiling and Holding a Medical Thesaurus

A method is described to compile and hold a medical thesaurus through a combination of intellectual effort and the widest possible use of computerization. Various techniques, such as the automatic generation of relationships among terms, are discussed.

Certains suggestions are offered as to the kind of assistance a computer can provide.

Factors Generating Glucose Degradation Products In Sterile Glucose Solutions For Infusion: Statistical Relevance Determination Of Their Impacts

Sterilising glucose solutions by heat promotes the generation of a large number of glucose degradation products (GDPs). It has been shown that high levels of GDPs may result in Advanced Glycation End products that have an impact on cellular homeostasis and health in general. If data is available for peritoneal dialysis solutions, little has been published for glucose infusion fluids. It is essential to identify the parameters causing the formation of GDPs and so limit the risk of exposing patients to them. After quantifying both 5-hydroxymethyl-2-furfural, considered as an important indicator of degradation, and 2-furaldehyde, an ultimate GDP of one degradation pathway, in marketed solutions, the aim of this work is to build a model integrating all the parameters involved in the formation rates of these two GDPs: supplier, glucose amount, container material, oxygen permeability coefficient and time-lapse since manufacture. Our results show a good logarithmic relationship between GDP formation rates and time-lapse since manufacture for both GDPs. The amount of GDPs in the glucose solutions for infusion depends on the initial glucose amount, the polymer of the container, the time elapsed since manufacturing and the supplier.

[Impact of education program and clinical posting in psychiatry on medical students' stigmatizing attitudes towards psychiatry and psychiatric disorders]

OBJECTIVE

The aim of the study was to explore whether a medical student education program and clinical posting in psychiatry had an impact on medical students' stigmatizing attitudes towards psychiatry and psychiatric disorders.

METHODS

Medical students from the University of Bordeaux were recruited during their 4-year course at the beginning of the academic education program in psychiatry. Medical students who were concomitantly in a clinical posting in wards of psychiatry or neurology were invited to participate in the study. The medical student version of the scale Mental Illness: Clinicians' Attitudes (MICA) was used to measure their attitudes towards psychiatry and persons with psychiatric disorder. This 16-item scale is designed to measure attitudes of health care professionals towards people with mental illness, a higher score indicating more stigmatizing attitudes. Items exploring history of psychiatric disorders in close persons were added at the end of the MICA scale. The questionnaire was completed twice by each student, at the beginning and the end of the 11-week clinical posting. All questionnaires were strictly anonymized. Multivariate linear regression analyses were used to identify the variables independently associated with MICA total score.

RESULTS

At the beginning of the education program and clinical posting, 174 students completed the MICA scale: the mean MICA total score was equal to 46.4 (SD 6.9) in students in clinical posting in psychiatry (n=72) and 45.1 (SD 7.01) in those in neurology (n=102). At the end of the academic and clinical training, 138 students again completed the questionnaire, with mean MICA total scores equal to 41.4 (SD 8.1) in students in clinical posting in psychiatry (n=51) and 43.5 (SD 7.3) in those in neurology (n=87). Multivariate analyses showed that lower total MICA scores were independently associated with the time of assessment (lower scores at the end of education program and clinical posting) (b=-2.8; P=0.001), female gender (b=-1.8; P=0.03) and history of a psychiatric disorder in a close person (b=-1.92; P=0.02). Type of clinical posting (psychiatry vs. neurology) was not independently associated with MICA total scores (b=-0.02; P=0.98). A significant interaction was found between the variables "time of assessment" and "type of clinical posting" (P=0.05): stratified analyses showed that MICA total scores decreased significantly only when the clinical posting was in psychiatry (b=-4.66; P=0.001), with no significant change in medical students in neurology wards (b=-1.45; P=0.16).

CONCLUSION

Stigmatizing attitudes of medical students towards psychiatry and psychiatric disorders are reduced by an education program in psychiatry, with a positive impact more marked when the education program is concomitant to a clinical posting in psychiatry. As future health professionals in charge of persons with psychiatric disorders, medical students are key targets of actions aimed at reducing stigma towards mental health disorders. It is hence of great importance to promote clinical training in psychiatric wards during medical studies for all future practitioners, irrespective of their future specialty.

Analysis of plasticizers in PVC medical devices: Performance comparison of eight analytical methods

A wide variety of medical devices (MDs) used in hospitals are made of flexible plasticized polyvinylchloride (PVC). Different plasticizers are present in variable amounts in the PVC matrix of the devices and can leach out into the infused solutions and may enter into contact with the patients. The ARMED¹ project aims to assess the migration of these plasticizers from medical devices and therefore the level of exposure in patients. For the first task of the project, eight methods were developed to directly detect and quantify the plasticizers in the PVC matrix of the MDs. We compared the overall performances of the analytical methods using standardized and validated criteria in order to provide the scientific community with the guidance and the technical specifications of each method for the intended application. We have shown that routine rapid screening could be performed directly on the MDs using the FTIR technique, with cost-effective analyses. LC techniques may also be used, but with limits and only with individual quantification of the main plasticizers expected in the PVC matrix. GC techniques, especially GC-MS, are both more specific and more sensitive than other techniques. NMR is a robust and specific technique to precisely discriminate all plasticizers in a MD but is limited by its cost and its low ability to detect and quantify plasticizer contamination, e.g. by DEHP. All these results have been confirmed by a real test, called the " blind test " carried out on 10 MD samples.

Measles outbreak in a refugee settlement in Calais, France: January to February 2016

We report a measles outbreak in a refugee settlement in Calais, France, between 5 January and 11 February 2016. In total, 13 confirmed measles cases were identified among migrants, healthcare workers in hospital and volunteers working on site. A large scale vaccination campaign was carried out in the settlement within two weeks of outbreak notification. In total, 60% of the estimated target population of 3,500 refugees was vaccinated during the week-long campaign.

Nicotine and Cotinine Levels With Electronic Cigarette: A Review

BACKGROUND

Since their introduction in 2004, electronic cigarettes (e-cigarettes) have gained popularity worldwide. E-cigarettes are marketed as nicotine delivery devices. Commonly reported reasons for use include to quit smoking, to reduce urge to smoke, or the perceived lower risk alternative to smoking. But what are the actual amounts of nicotine delivered?

AIM

This review summarizes all the published studies concerning nicotine or cotinine levels following e-cigarette use.

METHODS

A literature search was conducted from the PubMed database, from 1985 to January 2014, using the following terms: electronic cigarette(s), e-cigarette(s), electronic nicotine delivery system, cotinine, and nicotine. Articles were excluded if they were not pertinent according to our criteria. References of all relevant articles were also evaluated.

RESULTS

Eight studies were included in this review. The following information was extracted from the articles: population size, age of participants, recruitment, inclusion and exclusion criteria, concentration of nicotine in refills liquids, study sample design, and observed concentrations. Following design of studies, plasma nicotine Cmax was observed between 0 and 5 ng/mL (no significant changes) or between 13.9 and 16.3 ng/mL (similar to a tobacco cigarette) with a Tmax between 70 and 75 minutes. Cotinine levels after "vaping" an e-cigarette are similar to a tobacco cigarette.

CONCLUSION

This review summarizes e-cigarette studies that contain information on nicotine or cotinine levels. The peak concentration of nicotine appears to be dependent on the use and dose level of e-cigarette cartridge. The value of this peak concentration is similar to the value found with a tobacco cigarette. However, the time corresponding to the peak concentration is delayed compared to a tobacco cigarette.

Attention-deficit/hyperactivity disorder (ADHD) in adults: Specific clinical and therapeutic issues

Attention-deficit/hyperactivity disorder (ADHD) was initially considered as a childhood psychiatric disorder. However, longitudinal observations have revealed that ADHD symptoms may persist in adulthood among approximately 50% of the patients . Adult ADHD is associated with impaired social outcome and frequent comorbidities such as mood disorders, personality disorders, and substance use disorders [2,3]. Correctly identifying and treating ADHD can significantly improve the global functioning and cognition of adult subjects, and reduce the intensity and frequency of the comorbid states [2,3]. Nonetheless, the clinical features of adult ADHD are clearly different from the youth form [1,2], and ADHD symptoms are easily mixed up in adults with symptoms of the comorbid conditions [2,3]. These clinical intricacies can make the diagnosis of ADHD difficult in adults. Moreover, the management of methylphenidate in adult subjects is also associated with specific risks and pitfalls, such as abuse and tampering behaviors, and additional safety risks . Put together, it appears crucial to identify and treat ADHD in adults, but the clinical and therapeutic complexities of adult ADHD require improved expertise and caution from adult psychiatrists and addiction specialists. In this thematic session of the 2015 French Psychiatry Congress, three French leading experts of adult ADHD will address the aforementioned clinical and therapeutic issues of the adulthood form of this disorder. David Da Fonseca, professor of child psychiatry in Marseille, will disentangle the clinical features of adult ADHD from the typical symptoms observed in the youth form. Mélina FATSEAS, associate professor of psychiatry and addiction medicine in Bordeaux, will specifically focus on the many and complex relationships observed between adult ADHD and substance use disorders. Last, Nicolas Simon, professor of addiction medicine and psychopharmacology in Marseille, will synthesize what are the very risks and issues with prescribing methylphenidate in adults.

Effet longitudinal d’une administration aiguë d’éthanol sur le GABA et le glutamate : une étude en spectroscopie par résonance magnétique in vivo chez le rat

Introduction

Les effets cliniques de l’intoxication alcoolique aiguë seraient liés à une modulation des systèmes de neurotransmission du GABA et du glutamate. Les caractéristiques longitudinales de cette modulation et l’impact de la dose d’éthanol absorbée restent mal connus. Nous avons voulu étudier in vivo les effets aigus de l’éthanol sur les niveaux de GABA et de glutamate du cortex préfrontal en spectroscopie par résonance magnétique (SRM).

Matériel et méthodes

Après une première acquisition de SRM (zone préfrontale), trois groupes de rats Wistar mâles (363 ± 27 g) ont reçu par voie intrapéritonéale (IP) :

– éthanol 1 g/kg (n = 6) ;

– éthanol 2 g/kg (n = 8) ;

– sérum physiologique (n = 5).

Des acquisitions répétées de SRM ont été réalisées jusque 300 minutes post-injection. Une cinétique de l’éthanolémie a également été réalisée dans des groupes similaires de rats Wistar. Après alcoolisation par voie IP, des prélèvements sanguins successifs ont été réalisés jusque 180 minutes pour le groupe 1 g/kg (n = 6) et 300 minutes pour le groupe 2 g/kg (n = 14). Pour la SRM, des analyses statistiques inter- et intragroupes ont été effectuées à l’aide d’un modèle linéaire mixte visant à étudier la variation des taux de GABA et glutamate.

Résultats

La cinétique de l’éthanolémie était superposable à celle de la cinétique cérébrale. En SRM, une diminution significative du GABA, de 11,4 % ± 3,8 % (p < 0,0059) dans le groupe 1 g/kg et du glutamate de 13,8 % ± 2,6 % dans le groupe 2 g/kg (p < 0,0001) ont été observées, sans modification significative dans les autres groupes. La variation du ratio GABA/glutamate s’est montrée différente entre les deux groupes éthanol avec une augmentation dans le groupe 2 g/kg et une diminution dans le groupe 1 g/kg (p < 0,01).

Conclusion

La dose d’éthanol détermine les variations des niveaux de GABA et de glutamate du cortex préfrontal, pouvant expliquer les différents effets cliniques induits par l’alcool selon la dose.

Interplay between the genetic clades of Micromonas and their viruses in the Western English Channel

The genus Micromonas comprises distinct genetic clades that commonly dominate eukaryotic phytoplankton community from polar to tropical waters. This phytoplankter is also recurrently infected by abundant and genetically diverse prasinoviruses. Here we report on the interplay between prasinoviruses and Micromonas with regard to the genetic diversity of this host. For 1 year, we monitored the abundance of three clades of Micromonas and their viruses in the Western English Channel, both in the environment using clade-specific probes and flow cytometry, and in the laboratory using clonal strains of Micromonas clades to assay for their viruses by plaque-forming units. We showed that the seasonal fluctuations of Micromonas clades were closely mirrored by the abundance of their corresponding viruses, indicating that the members of Micromonas genus are susceptible to viral infection, regardless of their genetic affiliation. The characterization of 45 viral isolates revealed that Micromonas clades are attacked by specific virus populations, which exhibit distinctive clade specificity, life strategies and genetic diversity. However, some viruses can also cross-infect different host clades, suggesting a mechanism of horizontal gene transfer within the Micromonas genus. This study provides novel insights into the impact of viral infection for the ecology and evolution of the prominent phytoplankter Micromonas.