Load-dependent electrophysiological and structural cardiac remodelling studied in ultrathin myocardial slices.

Introduction: Myocardial slices are becoming an established system to study cardiac electrophysiology and pharmacological research and development. Unlike other preparations, cardiac slices are a multicellular preparation that has an intermediate, adequate complexity required for this research. Previous studies have successfully obtained slices from human biopsies and animal models, where the electrical and structural parameters could be maintained for several hours – a process which is comparable to other preparation types. Therefore, we aimed to use left ventricular myocardial slices obtained from rat models of mechanical unloading (HAHLT) and from two models of overload (TAC and SHR), to investigate electrophysiological and structural alterations in these models. Methods: Mechanical unloading was achieved by heterotopic abdominal heart and lung transplantation (HAHLT, 8 weeks) and overload was induced by thoracic aortic constriction (TAC, 10 and 20 weeks) in male Lewis rats. Spontaneous hypertensive rats (SHR) were also used as a second model of overload and were primarily induced by hypertension (3, 12 and 20 months). Brown Norway and Wistar Kyoto rats were used as the control groups for SHR. Myocardial slices from the left ventricle (LV) free wall were cut (300-350 µm thick) tangentially to the epicardial surface using a high-precision slow-advancing Vibratome and were point-stimulated using a multi-electrode array system (MEA), therefore, acquiring field potentials (FPs). Field potential duration (FPD) and conduction velocity (CV) were analysed locally and transmurally across the LV free wall. In addition, FPD heterogeneity within each slice was calculated. For the SHR group, the same slices used for the MEA recording were preserved and used subsequently to measure Cx43, Nav1.5 protein levels and fibrosis. Results: Slices obtained from normal rat hearts that are chronically unloaded were found to develop atrophy at a whole heart level. They showed an increase in FPD and its heterogeneity with preserved conduction properties when compared to controls. In TACs, an in vivo whole heart function assessment confirmed hypertrophy with no signs of cardiac dysfunction. Slices from TAC rats showed an increase in FPD at both 10 and 20 weeks after banding. FPD heterogeneity was increased at 10 weeks but normalised at 20 weeks. Changes in CV properties were observed in this group, showing a faster CV and longitudinal conduction velocity (CVL) at 10 weeks and no change at 20 weeks. Transverse conduction velocity (CVT) was unchanged in the TAC group. In SHRs, however, hypertrophy was confirmed and signs of dysfunction in the aged group (20 months) were observed due to the decrease in EF by 18%, especially when compared to the 12 months group. FPD and its heterogeneity was unchanged in SHR when compared to controls. Disease and age-related abnormalities in CV properties were observed in SHR and these were associated with changes in Cx43, Nav1.5 protein level and fibrosis. Conclusion: Myocardial slices are a suitable multicellular preparation to study electrophysiological remodelling obtained from different rat models of cardiovascular disease. In addition, it was possible to investigate the changes in CV and FPD transmurally in rats using this type of preparation method. Thus, this study supports the use of this multicellular preparation in understanding the mechanisms of cardiac disease and the testing of new treatments and therapeutic targets.Open Acces

Risk Analysis for Intermittent Water Supply Systems

Systémy s přerušovanou dodávkou vody jsou dnes běžně realizovány v některých rozvojových zemích a to z důvodu minimalizace problémů způsobených nedostatkem vody. Proměnlivé hydraulické podmínky v distribučních systémech, nízké tlaky, vysoké riziko kontaminace, plýtvání vodou, nárůst cen, které platí spotřebitelé a poskytovatelé vody, poruchy a problémy při měření spotřeby vody a nepříjemnosti pro spotřebitele s tím spojené, to jsou některé důsledky provozování takovýchto systémů. Za použití Studie nebezpečí a provozuschopnosti HAZOP (HAZard and OPerability technique) byla vyvinuta metodika rizikové analýzy pro systémy s přerušovanou dodávkou vody a byl vytvořen katalogový seznam potenciálních nežádoucích stavů (NS), které mohou nastat v systému tohoto typu. V této práci je také popsáno použití rozvinuté metodiky a Analýzy stromu poruchových stavů FTA (Fault Tree Analysis), která je použita k analýze pravděpodobností a důsledků včetně ohodnocení stupně rizika s nejistotou pro jeden z nežádoucích stavů NS_Nízký provozní tlakIntermitted Water Supply strategy is implemented commonly in some developing countries nowadays in order to minimize the water scarcity problems. Unstable hydraulic conditions in the distribution system, low pressure, high risk of water contamination, wasting water, rising costs paid by consumers and water providers, failures and problems with consumption metering and inconvenience to consumers are some of the consequences. Risk Analysis Methodology is developed to handle with intermittent water supply systems in developing countries conditions that include undesired events identification; risk estimation and risk evaluation and reduction plan, the catalogue list of potential undesired events (UE) which may occur in these types of systems have been also developed using the HAZard and OPerability technique (HAZOP). The developed methodology is implemented and tested in this research on one of the potential undesired events UE _ Low operational pressure

Effect of Different Essential Oils on the Shelf Life of Concentrated Yogurt

Aims: The objective of this study is to use different essential oils (cinnamon, clove, rosemary, almond sweet, sesame, wheat germ, and cedar wood) in concentrated yoghurt as antimicrobial agents to increase shelf life of concentrated yoghurt. Place and Duration of Study: Department of Food Technology, Faculty of Science and Technology, Al-Quds University, Palestine, between January 2015 to August 2016. Methodology: Essential oils were added to concentrated yogurt at a concentration of 250 μl\kg. Antibacterial activity and properties of major borne bacteria such as total aerobic count bacteria, yeast, mold, Staphylococcus aureus, were evaluated by plate count method, (pouring plate method). All yogurt samples were sensory evaluated for flavor, body and texture, and appearance. Total solid content, and titratable acidity of different yogurt samples were also determined. Results: Total solids and pH of concentrated yogurt samples treated with essential oils were only slightly affected. The best three essential oils used in terms of influence on total bacterial viable count and mold count were found to be cinnamon, clove and rosemary. The most acceptable organoleptic properties of treated concentrated yogurt were those samples treated with sesame and rosemary oils. Conclusion: The addition of cinnamon, clove and rosemary essential oils could increase the shelf life of concentrated yogurt.The authors thank Al- Jibrini for food industries - Hebron, West Bank, Palestine

Use of cinnamon, wheat germ, and eucalyptus oils to improve quality and shelf life of concentrated yogurt (Labneh)

Three essential oils, namely cinnamon, eucalyptus, and wheat germ were added to concentrated yogurt (Labneh) at a concentration of 600 μL\kg. The chemical, microbiological and organoleptic properties of freshly prepared and stored Labneh at 5°C ± 1 for 6 weeks were determined. Addition of essential oils affected slightly the pH, acidity, total solids, and dry matter values of concentrated yogurt. Total viable counts, as well as counts of Streptococcus aureus, molds, and yeast in the treated Labneh were affected during storage period. The most acceptable organoleptic properties of treated Labneh were those samples treated with cinnamon, and eucalyptus oils, and to a lesser extent wheat germ oil. Cinnamon and eucalyptus oils were also found to inhibit yeast and mold count. It has been also found that cinnamon and eucalyptus essential oils decreased significantly the growth of S. aureus. No Coliforms or E. coli bacteria were detected in the treated Labneh, as well as in the positive control. This study showed that wheat germ oil had lesser effect compared to cinnamon, and eucalyptus. This study concluded that, addition of cinnamon and eucalyptus essential oils at 600 μL\kg could increase the shelf life of Labneh up to 6 weeks at 5 ± 1°C with acceptable taste, flavor and texture without addition of any chemical preservative.Acknowledgements The authors thank Al- Jibrini for food industries- Hebron, West Bank, Palestine. Funding The authors received no direct funding for this research

The development and validation of a multivariable model to predict the bleeding risk score for patients with non-valvular atrial fibrillation using direct oral anticoagulants in the Arab population.

Background Frequently used models, such as the HAS-BLED, ATRIA, ORBIT, and GARFIELD-AF evaluate the risk of bleeding when using an anticoagulant, for example warfarin, in patients with non-valvular atrial fibrillation. Limited studies are available reporting a model with a good discriminative ability to predict the bleeding risk score when using direct oral anticoagulants. Methods Patient data were collected from King Abdulaziz Medical City, King Fahad Cardiac Center, and Prince Sultan Cardiac Center in Riyadh, from outpatients, inpatients, or primary care clinics. In total, 1722 patients with a prescription for a new oral anticoagulant, Dabigatran, Rivaroxaban, or Apixaban, were enrolled. A resampling approach for variable selection was used and a five-fold cross-validation to assess the model fit and misclassification probabilities. The analysis used the receiver operating characteristics curve (ROC) and the concordance (c) statistic to assess the validation models’ discriminative power. The final penalized likelihood parameters were used for the development of the risk prediction tool. The accuracy of a classification and the prediction are reported with the sensitivity, specificity, and Brier score. Results Bleeding occurred in 11.15% of cases, of which 23.08% required a blood transfusion and 51.65% had a reduction in haemoglobin of more than 2 gm. The variable selection model identified 15 predictors associated with major bleeding. The discriminative ability of the model was good (c-statistic 0.75, p = 0.035). The Brier score of the model was 0.095. With a fixed cut-off probability value of 0.12 for the logistic regression equation, the sensitivity was 72.7%, and the specificity 66.3%. Conclusion This model demonstrated a good performance in predicting the bleeding risk in Arab patients treated with novel oral anticoagulants. This easy to use bleeding risk score will allow the clinician to quickly classify patients according to their risk category, supporting close monitoring and follow-up for high-risk patients, without laboratory and radiological monitoring

Production de bioéthanol à partir d'hydrolysats enzymatiques de substrats (ligno)cellulosiques prétraités par des liquides ioniques

The lignocellulosic biomass (LCB), derived from forest and/or agricultural residues, represents a promising and renewable feedstook to produce second generation bioethanol and to handle the depletion of fossil fuels. The bioethanol production process applied in this study starts with a LCB pretreatment using two hydrophilic imidazolium-based ionic liquids (ILs), the 1-éthyl-3-méthylimidazolium acétate [Emim][OAc] and the 1-éthyl-3-méthylimidazolium méthylphosphonate [Emim][MeO(H)PO2], followed by an enzymatic hydrolysis by cellulases from Trichoderma reesei and xylanases from Trichoderma longibrachiatum and a microbial ethanolic fermentation tested with four yeast species: Saccharomyces cerevisiae, Kluyveromyces marxianus, Scheffersomyces shehatae and Scheffersomyces stipitis. Two real LCBs were studied : the white willow (forest residue) and the destarched wheat bran (agricultural residue). The results showed that IL-pretreatment of LCBs at 35°C improves the polysaccharides enzymatic digestibility (up to +56.7% for glucose yields and up to +31.1% for xylose yields) in comparison with the control without pretreatment. In addition, the performance of ethanolic fermentation processes is enhanced by a factor of 1.3 to 4.6 depending on the substrate studied and the yeast species used. Thus, ILs are promising solvents for the pretreatment of (ligno)cellulose at low temperatures allowing an improvement in enzymatic hydrolysis and ethanolic production yieldsLa biomasse lignocellulosique (BLC), composée des déchets végétaux agricoles et/ou forestiers, représente une ressource renouvelable prometteuse pour la production de bioéthanol de deuxième génération et faire face à l'épuisement des énergies fossiles. Le procédé de valorisation de la BLC appliqué ici comprend une étape de prétraitement par deux liquides ioniques (LI) hydrophiles dérivés d'imidazolium, le 1-éthyl-3-méthylimidazolium acétate [Emim][OAc] et le 1-éthyl-3-méthylimidazolium méthylphosphonate [Emim][MeO(H)PO2], puis une hydrolyse enzymatique par des cellulases de Trichoderma reesei et des xylanases de Trichoderma longibrachiatum, suivie d'une étape de fermentation éthanolique microbienne testée sur quatre espèces de levures: Saccharomyces cerevisiae, Kluyveromyces marxianus, Scheffersomyces shehatae et Scheffersomyces stipitis. Deux BLC réelles ont été étudiées : le saule blanc (résidu forestier) et le son de blé désamidonné (résidu agricole). Les résultats ont montré que le prétraitement des BLC aux LI à 35°C permet une augmentation de la digestibilité enzymatique des polysaccharides (rendements en glucose jusqu'à +56,7% et rendements en xylose jusqu'à +31,1%) par rapport au contrôle sans prétraitement. De plus, la performance des procédés de fermentation éthanolique est améliorée d'un facteur 1,3 à 4,6 en fonction du substrat étudié et de l'espèce de levure utilisée. Ainsi, les LI sont des solvants prometteurs pour le prétraitement de la (ligno)cellulose à basse température permettant une hausse des rendements d'hydrolyse enzymatique et de production éthanoliqu

Generation and Correction of a Novel Mouse Model of Farber Disease

Farber disease is a fatal inherited disorder of lipid metabolism. It is characterized by a deficiency of the lysosomal enzyme acid ceramidase (AC), resulting in the buildup of the bio-effector molecule ceramide. A previous attempt to generate a Farber mouse model by Asah1 knockout was unsuccessful owing to embryonic lethality in homozygous embryos. Here, we successfully generated viable homozygotes that developed Farber disease by introducing a single-nucleotide human patient mutation into a conserved region of murine Asah1 (P361R). Indeed, homozygotes manifested Farber disease symptoms and died within 7-13 weeks. Furthermore, treatment of neonatal pups with intravenous injections of AC lentiviral vectors (LVs) yielded homozygotes with intermediate Farber phenotypes highlighted by reduced symptoms and increased longevity. Therefore, this first model of Farber disease can facilitate the advancement of experimental therapies and offer mechanistic insights into the integral roles of acid ceramidase, ceramide, and related sphingolipids in cell signaling, growth, and oncogenesis.MAS