Cholinesterase activity and histopatological changes in the Mediterranean crab, Carcinus maenas, exposed to environmental contaminants

Marine environments are continuously being threatened by a large number of pollutants including heavy metals and organophosphorous pesticides from anthropogenic sources. These compounds can cause a serious environmental problem. The present study aimed: (1) to measure sensitivity of acetylcholinesterase (AChE) activity to in vivo exposure to the organophosphorous chlorpyriphos-ethyl (CPF) and to the heavy metals cadmium (Cd) and copper (Cu) and (2) to use the histopathological lesions as tissue biomarkers for biomonitoring of different contaminations. The results clearly showed that the AChE activity in different tissues (digestive gland, muscle and eyes) of Carcinus maenas was relatively sensitive to the concentrations of CPF and tended to have different patterns in response to Cd, Cu and Cu+Cd mixture exposure. The transfer of treated crabs to the clean sea water allowed to recover totally or partially the lost activity depending on selected tissues and contaminant exposure (metals or organophosphorous compounds). Histopathological biomarkers in C. maenas exposed to different contaminants showed the presence of different lesions which altered the digestive gland after 7 days of contamination

EFFECTS OF OLIVE DRYING AND STORAGE ON THE OXIDATIVE STATUS, AROMA, CHLOROPHYLL AND FATTY ACIDS COMPOSITION OF OLIVE OIL

Objective: In this study, we thoroughly investigate the effect of drying and storage of olives from four Tunisian cultivars (Chetoui, Chemlali, Oueslati and Picholine) on the final composition of olive oil.Methods: Olives were dried using three different methods: ambient air, infrared radiation and oven heating. Oven-dried olives were stored during six months. Extraction was conducted using a soxhlet apparatus. Its quality was assessed by analyzing the fatty acid and aroma composition on one hand, and on the other hand by evaluating the total chlorophyll content and measuring specific extinctions at 232 and 270 nm.Results: The main results show that air dried fruits (Chetoui cultivar) gave the most pigmented oil (3.32 ppm of total chlorophylls) followed by oven dried olives (1.12 ppm), whereas infra-red dried olives had the least amount of chlorophylls (0.98 ppm). Furthermore, the highest amount of total aroma was found in oven dried fruits whereas the lowest one characterized infrared dried olives. Fatty acid composition of our oils wasn't affected by drying techniques. Also, oven dried and stored olives showed an insignificant change in chlorophyll contents and aroma composition (Chetoui variety), coupled with a decreased level of total fatty acid amount as of the third month of preservation.Conclusion: Drying techniques and storage affected aroma compounds, while oil oxidation, chlorophyll and fatty acid composition were unaffected. A better control for drying and storage should be developed to insure a better quality of olive oil. A comparison should be done between the current study and salt and dried olive preservation in order to offer hypertensive patients fruits with preserved nutritional values and the peculiar delicate flavour characteristic of olive oilÂ

Drug Abuse-Induced Cardiac Arrhythmias: Mechanisms and Management

Toxicomania is a worldwide emerging problem threatening young population. Several reports highlighted its hazardous cardiovascular effects. Sudden cardiac death secondary to cardiac arrhythmias is the most occupying issue. Different forms of cardiac rhythm disorders may be induced by illicit drug abuse according to the type of drug and the mechanism involved. In this review, we exposed the main ventricular and supraventricular arrhythmia complicating the common recreational drugs, and we explained their different mechanisms as well as the particularities of management

Cholinesterase activity as biomarker of neurotoxicity: utility in the assessment of aquatic environment contamination * Actividade da colinesterase como biomarcador de neurotoxicidade: avaliação da contaminação em ambientes aquáticos ** ** Portuguese Titl

AbstrAct Cholinesterase can take place in aquatic organisms under a series of environmental adverse conditions. The study of cholinesterases in these organisms can give important information about their physiological status and about environmental health. However, it is very important to know how the environmental factors such as fluctuation of physicochemical parameters associated to the presence of pollutants might affect these cholinesterase activities. We studied the response of cholinesterase activity in the caged cockle Cerastoderma glaucum. In addition, we evaluated the potential uses of cholinesterase activity in the common sole, which inhabit the Tunisian coast, subjected to different stress conditions, such as the exposure to different contaminants. This review summarizes the data obtained in some studies carried out in organisms from the Tunisian aquatic environment. Keyword

The shortfall and rise in energy deposition and combustion via OpenFOAM

In the energy deposition process, a heat source is used to melt a powder or wire as it is being deposited onto the face of a material. While powder provides for greater deposition accuracy, wire appears to be more resource efficient than powder. The procedure involves layering materials and allowing them to harden in a melt pool to create new features. Experiments that explore energy deposition are expensive. As a result, Computational Fluid Dynamics (CFD) may be used to simulate the flame or energy deposition. Fick's law is used to describe the transmission of mass fraction species and energy deposition in this model. Fourier's law is used to calculate the temperature field in the CFD model. For the flow of flame, the Navier-Stokes equations of motion are used. Based on the combustion and energy deposition, this verified CFD model may be used to optimize the operational parameters for regulating the size of the flame and the temperature distribution of the flame. The rise in energy deposition near thin channel and combustion tank is examined in the study. The simulation of the issue is done using the Finite Volume Method (FVM). OpenFOAM is being used in producing the graphical results

Cardiomyopathy induced by incessant ventricular tachycardia originating in the vicinity of the His bundle

A 04-year-old boy was referred to our institution with severe, progressive heart failure of 4-months duration associated with a persistent wide QRS tachycardia with left bundle branch block and severe left ventricular dysfunction. Because of incessant wide QRS tachycardia refractory to antiarrhythmic drugs, he was referred for electrophysiological study. The ECG was suggestive of VT arising from the right ventricle near the His area. Electrophysiological study revealed that origin of tachycardia was septum of the right ventricle, near His bundle, however the procedure was not successful and an inadvertent complete atrioventricular conduction block occurred. The same ventricular tachycardia recurred. A second procedure was performed with a retrograd aortic approach to map the left side of the interventricular septum. The earliest endocardial site for ablation was localized in the anterobasal region of left ventricle near His bundle. In this location, one radiofrequency pulse interrupted VT and rendered it not inducible. The echocardiographic evaluation showed partial reversal of left ventricular function in the first 3 months. The diagnosis was idiopathic parahisian left ventricular tachycardia leading to a tachycardia mediated cardiomyopathy, an extremely rare clinical picture in children. Keywords: Parahisian ventricular tachycardia, Tachycardia mediated cardiomyopathy, Radiofrequency catheter ablation, Childre

Adherence of North-African Pulmonologists to the 2017-Global Initiative for Chronic Obstructive Lung Disease (GOLD) Pharmacological Treatment Guidelines (PTGs) of Stable Chronic Obstructive Pulmonary Disease (COPD)

Background. No previous study has investigated the adherence rate of North-African pulmonologists to the 2017-GOLD PTGs. Aims. To investigate the adherence rate of Tunisian pulmonologists to the 2017-GOLD PTGs and to identify the barriers to their adherence. Methods. This was a cohort study involving clinically stable COPD patients who presented to a pulmonology outpatient consultation. The patients were classified as having been appropriately and inappropriately (over- or undertreatment) treated for the GOLD group. Logistic regression was performed to determine the adherence barriers to the 2017-GOLD PTGs. Results. A total of 296 patients were included (88.1% males, mean age: 68±10 years; GOLD A (7.1%), B (36.1%), C (4.1%), and D (52.7%)). The pulmonologists’ adherence rate to the 2017-GOLD PTGs was 29.7%. There was a significant statistical difference between the adherence rates among the four GOLD groups (A: 19.0%, B: 20.6%, C: 8.3%, and D: 39.1%; p=0.001). Differences were statistically significant between the GOLD group D and groups B (p=0.001) and C (p=0.033). The multivariate analysis showed that age (odds ratio (OR): 0.968), socioeconomic level (high/medium vs. low; OR: 2.950), insurance type (national health insurance vs. others; OR: 2.851), and GOLD groups (A/B vs. C/D; OR: 3.009) significantly influenced the adherence rate to the 2017-GOLD PTGs. Conclusion. The adherence rate of Tunisian pulmonologists to the 2017-GOLD PTGs is low. It seems that the patients’ age, socioeconomic level, national health insurance coverage, and GOLD groups influenced their adherence