Instrument d’aide au diagnostic en psychophysiologie : Cas de l’activite electrodermale (AED)

Les progrès de l’électronique et en particulier ceux réalisés en instrumentation ont rendu possible la modernisation des électrophysiographes et  l’émergence de la neuro-imagerie. Toutefois malgré les bases posées par FERE et TARCHANOFF depuis 1888, un retard s’observe dans les domaines  de la psychophysiologie compte tenu de la quasi-inexistence d’un outil fiable d’aide au diagnostic. Dans cet article, un appui est pris sur la méthode  de FERE pour concevoir et réaliser un instrument d’enregistrement et d’analyse de l’activité électrodermale. En effet, peu exploitée dans les  diagnostics psychiatriques, l’activité électrodermale est un paramètre physiologique qui traduit de façon instantanée l’état émotif ou mental d’une  personne à travers la variation de la conductance cutanée. Ainsi, une tension continue constante de 500 mV appliquée aux bornes de deux  électrodes placées sur les phalanges distales de l’index et du majeur de la main non dominante de cinq (5) candidats, défendant leur mémoire de fin  de formation, a permis d’enregistrer les variations de la conductance de leur peau. La valeur analogique mesurée est échantillonnée par le  convertisseur analogique-numérique de l’ATmega168, avant d’être transmise via une liaison série sur l’ordinateur pour enfin faire l’objet d’une  analyse d’amplitude.   Advances in electronics and in particular those made in instrumentation have made possible the modernization of electrophysiographs and the  emergence of neuro-imaging. However despite the groundwork laid by FERE and TARCHANOFF since 1888, a delay occurs in the field of psychiatry  and psychophysiology, given the virtual absence of a tool for diagnosis. In this project, basis is taken on the method of FERE to design and  implement an instrument for recording and analysis of ElectroDermal Activity. Indeed, little used in psychiatric diagnosis, electrodermal activity is a  physiological parameter which expresses the instantaneous emotional or mental state of a person through the change in skin conductance or  potential. Thus, we applied a constant voltage of 500 mV at the terminals of two electrodes placed on the distal phalanges of index and middle  fingers of the non-dominant hand of five (5) candidates, defending their thesis at the end of training, and we recorded the changes in conductance  of their skin. The measured analog value is sampled by the analog-digital converter of the ATmega168, before being transmitted via a serial port on  the computer for amplitude analysis.&nbsp

Medical devices in Sub-Saharan Africa : optimal assistance via a computerized maintenance management system (CMMS) in Benin

In limited resources settings, Health Technology Management (HTM) presents specific challenges, which significantly differ from those faced in higher income settings. In Sub-Saharan Africa (SSA), HTM requires holistic approaches based on reliable information on medical devices operationalized in local medical locations, which may differ significantly from the USA or European ones. Computerized Maintenance Management System (CMMS) tools offer unprecedented opportunities to optimize medical device organization and management in SSA. Nonetheless, CMMS for SSA should be designed to meet real local needs and facing local economic and organizational constraints

Catch-up validation study of an in vitro skin irritation test method based on an open source reconstructed epidermis (phase II)

AbstractTo replace the Draize skin irritation assay (OECD guideline 404) several test methods based on reconstructed human epidermis (RHE) have been developed and were adopted in the OECD test guideline 439. However, all validated test methods in the guideline are linked to RHE provided by only three companies. Thus, the availability of these test models is dependent on the commercial interest of the producer. To overcome this limitation and thus to increase the accessibility of in vitro skin irritation testing, an open source reconstructed epidermis (OS-REp) was introduced. To demonstrate the capacity of the OS-REp in regulatory risk assessment, a catch-up validation study was performed. The participating laboratories used in-house generated OS-REp to assess the set of 20 reference substances according to the performance standards amending the OECD test guideline 439. Testing was performed under blinded conditions. The within-laboratory reproducibility of 87% and the inter-laboratory reproducibility of 85% prove a high reliability of irritancy testing using the OS-REp protocol. In addition, the prediction capacity was with an accuracy of 80% comparable to previous published RHE based test protocols. Taken together the results indicate that the OS-REp test method can be used as a standalone alternative skin irritation test replacing the OECD test guideline 404

A systematic review of occupational radiation individual dose monitoring among healthcare workers exposed in Africa

International audienceDosimetric monitoring is useful to limit exposures to ionising radiation in medical occupational settings, and reduce subsequent health risks. Scientific literatures, such as the UNSCEAR report 2017 and International Atomic Energy Agency Report 2014b, updated information on this subject; however, few African works have been found. This is the reason why we undertook this study, which summarises existing information on monitoring external radiation exposure doses for the whole body, using data from medical workers on this continent. Using standard terms and combining different keyword searches for radiation dose monitoring among radiology healthcare workers in Africa, from the titles, abstracts, and full texts, we found 3139 articles in the PubMed/MEDLINE, Google Scholar and INIS databases. Two reviewers screened the retrieved publications based on predefined eligibility criteria to identify relevant studies, extract key information from each, and summarise the data in table form. A total of 20 potentially relevant articles were identified. Among these 20 articles, 15 reported the overall average annual effective dose. Studies included in this systematic review represent an inventory of the radiation protection of medical workers in various African countries, with a focus on the monitoring of occupational radiation exposure. The size of studied populations ranged between 81 and 5152 occupational exposed workers. The mean annual effective doses ranged from 0.44 to 8.20 mSv in all specialities of medical sectors, while diagnostic radiology ranged from 0.07 to 4.37 mSv. For the nuclear medicine and radiotherapy from medical groups, the mean annual effective dose varied between 0.56 and 6.30 mSv. Industrial and research/teaching sectors data varied between 0.38 to 19.40 mSv. In conclusion, more studies implemented on dosimetric monitoring in Africa are needed to get a real picture of occupational exposure in the continent

Antifungal Properties of Pimenta racemosa (Mill.) and Mentha x piperita (L.) Essential Oils against Fusarium oxysporum Causing Tomato Fruit Rot

peer reviewedFungal pathogens are responsible for the rot of tomatoes and cause health hazards to consumers as well as economic loss. The aims of this study were to evaluate the efficacy of essential oils from Pimenta racemosa (Mill.) and Mentha x piperita (L.) leaves as plant-based fungicide against Fusarium oxysporum strains associated with tomato rot. The chemical composition of the essential oils was determined by GC-MS analysis. Antifungal effects of essential oils against strain of F. oxysporum obtained from rotted tomato, were evaluated through the determination of Minimal Fungicide Concentration (MFC) and the Minimal Inhibitory Concentration (MIC). Results indicated that β-myrcene (19.48%), chavicol (15.39 %), and eugenol (46.65%) were the major components of the essential oil of Pimenta racemosa (Mill.). L-menthone (17.19 %), menthol (24.79%), and menthofuran (26.78 %) were the major components of the essential oil of Mentha x piperita (L.). Essential oil of Pimenta racemosa (Mill.) exhibited the highest antifungal activity against the growth of Fusarium oxysporum strain tested with a MIC and MFC of 0.75 and 1.25 μl.ml-1 respectively. These results provide an experimental basis for further research on the use of these plant extracts in the development of eco-friendly preservatives against fungi causing rots of tomato in post-harvest

Experimental Assessment of Workplace Radiation Exposure in Diagnostic X-ray Medical Imaging Centres in Benin from 2019 to 2020

International audienceThe ease of prescribing radiological examinations has prompted an expansion in radiological procedures and, consequently, an increase of occupational dose to medical imaging workers. However, little is known about radiation exposure in the workplace of medical radiology professionals in many countries, and in Benin particularly. The purpose of this study was to assess ambient radiation doses in diagnostic X-ray medical facilities in Benin and to observe whether exposure levels are below reference levels. A total of 72 public and private medical imaging centres participated in a cross-sectional study carried out from June 2019 to February 2020 in Benin. These centres had 59 X-ray, four chest and six computed tomography (CT) scan rooms. A calibrated radiameter able to measure short, pulsed or continuous X fields and gamma/beta (50 nSv to 10 Sv) was used to measure exposure levels in these functional rooms. Scattered X-ray doses and exposure time from radiological examinations both behind the lead glass of the control area to assess the levels of exposure of professionals and outside of the examination room to evaluate the level of exposure of the public (including non-exposed workers) have been provided. Equivalent doses estimated per hour were compared with the reference levels of 7.50 and 0.05 µSv per hour for workers and the public, respectively. At the control area, the mean/median (min-max) equivalent doses were 0.09/0.07 (0.00-0.21), 2.39/0.13 (0.00-75.67), and 228.39/28.65 (0.39-869.75) µSv per hour for the chest, X-ray, and CT-scan rooms, respectively. Among 69 examination rooms, 13.04% of the equivalent dose estimated in the workplace behind the lead glass was greater than 7.50 µSv per hour; 65 out of 69 examination rooms showed that 40.00% of the equivalent dose estimated behind the doors was greater than 0.05 µSv per hour. These results demonstrated that current controls, including leaded glass separating the control panel and leaded doors between the examination room and the corridor, are inadequate to limit radiation exposures. The controls must be upgraded and a dosimetry program should be implemented to monitor exposures of employees, patients, and visitors