Arginine vasopressin-induced glucagon release: interaction with glucose and cyclic AMP-dependent protein kinase

The first study purpose was to investigate the glucose dependency of arginine vasopressin (AVP)-induced insulin, glucagon and somatostatin release from the perfused rat pancreas. AVP (30 or 300 pmol/L) was tested in the presence of glucose concentrations of 0, 1.4, 5.5 (basal level), or 20 mmol/L. The findings from this study suggested that AVP may increase insulin and glucagon release by a direct action on beta- and alpha-cells, respectively. These increases are glucose-dependent; the higher the glucose concentration, the greater the enhancement of AVP-induced insulin release. In contrast, the lower the glucose concentration, the greater the enhancement of AVP-induced glucagon release. AVP not only can enhance glucose-induced insulin release, but also can initiate insulin release. alpha-cells are much more sensitive to AVP than beta-cells in hormone release. Furthermore, our results confirmed the previous findings that hypoglycemia directly increases glucagon and decreases insulin release.;The second study purpose was to characterize the mechanisms by which cAMP/PKA enhances AVP-induced glucagon release and provide further details in the intracellular molecular components involved in this enhancement, particularly at the level of exocytosis. Increasing intracellular cAMP levels by forskolin or IBMX enhanced AVP-induced glucagon release from the perfused rat pancreas and the clonal alpha-cells InR1G9. cAMP/PKA did not increase [Ca 2+]i nor did it;enhance AVP-induced [Ca2+]i increase. Forskolin and IBMX enhanced AVP-induced glucagon release in Ca2+-containing but not in Ca2+-free medium. InR1G9 cells were loaded with styryl dye FM1-43 to measure the size of readily releasable pool (RRP). The combination of AVP and forskolin induced higher increase in fluorescence intensity than AVP or forskolin alone, which reflects an increase in the size of the RRP. Secretory granules in the reserve pool (RP) are thought to be reversibly connected to the actin-based cytoskeleton by synapsin I. Pretreatment with antisynapsin I antibody abolished the effect of forskolin/AVP-induced glucagon release. In addition, FM1-43 loading experiments showed that synapsin I is involved in recruitment of secretory granules from RP to RRP. Our results suggested that cAMP, acting through PKA, increases the number of secretory granules in the RRP by mobilization of granules from the RP, an action mediated by synapsin I

Correlation between Antibacterial Activity and Free-Radical Scavenging: In-Vitro Evaluation of Polar/Non-Polar Extracts from 25 Plants

Objectives: The current study aimed to measure the antioxidant and antibacterial activities of 25 wild Palestinian edible plants, which were subjected to extraction by polar and non-polar solvents. Correlations between free radical scavenging activity and antibacterial activity of the extracts were assessed for both polar and non-polar fractions. Materials: Twenty-five wild edible plant species that are frequently consumed by people in Palestine (mainly in a rural area) were examined. Among them, 10 plant species were among those with the highest mean cultural importance values, according to an ethnobotanical survey that was conducted in the West Bank, Palestine, a few years ago. Method: The protocol of the DPPH assay for testing free-radical scavenging was utilized for determining EC50 values, while microdilution tests were conducted to determine the 50% inhibitory concentration (IC50) of the extracts for the microorganism Staphylococcus mutans. Results and Discussion: Eight extracts (non-polar fractions) were found to possess an antibacterial IC50 of less than 20 ppm, such as Foeniculum vulgare, Salvia palaestinafruticose, Micromeria fruticose, Trigonella foenum-graecum, Cichorium pumilum jacq, Salvia hierosolymitana boiss, Ruta chalepensis, and Chrysanthemum coronarium. The polar fractions possess higher antioxidant activity, while non-polar fraction possess higher antibacterial activity. Looking at all the results together can deceive and lead to the conclusion that there is no correlation between antibacterial activity against S. mutans and free radical scavenging (R2 equals 0.0538). However, in-depth analysis revealed that non-polar plant extracts with an EC50 of free radical scavenging 100 ppm have a four-fold order of enrichment toward more activity against S. mutans. These findings are of high importance for screening projects. A four-fold order of enrichment could save plenty of time and many in screening projects. The antibacterial active extracts marked by low-medium free radical scavenging might act through a mechanism of action other than that of highly active, free radical scavenging extracts. Conclusion: The screening of antioxidant and antimicrobial activity performed on 25 selected wild plant extracts revealed a satisfactory free radical scavenging and antimicrobial potential that could be of value in the management of oxidative stress. Further studies are recommended to explore novel and highly active natural antibacterial products.The Al-Qasemi Research Authority, and the Faculty of Medicine of Al Najah University, supported this work. We declare that the funders had no role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript

تحسين أنظمة دعم القرار في نظم التعليم باستخدام تقنيات التنقيب عن البيانات و التعلم الآلي

يهدف التنقيب عن البيانات التعليمية إلى دراسة البيانات المتوفرة في المجال التعليمي وإخراج المعرفة المخفية منه بغية الاستفادة منها في تعزيز عملية التعليم واتخاذ قرارات ناجحة من شأنها تحسين الأداء الأكاديمي للطالب. تقترح هذه الدراسة استخدام تقنيات التنقيب عن البيانات لتحسين التنبؤ بأداء الطلاب، حيث تم تطبيق ثلاث خوارزميات تصنيف Naïve Bayes, J48, Support Vector Machine)) على قاعدة بيانات أداء الطلاب ، ثم تم تصميم مصنف جديد لدمج نتائج تلك المصنفات الفردية باستخدام تقنية الدمج Voting Method  . تم استخدام الأداة   WEKAالتي تدعم الكثير من خوارزميات و طرائق التنقيب في البيانات. تظهر النتائج أن مصنف الدمج لديه أعلى دقة للتنبؤ بمستويات الطلاب مقارنة بالمصنفات الأخرى ، حيث حقق دقة تعرف وصلت  إلى74.8084 %  . و أفادت خوارزمية العنقدةsimple k-means  في تجميع الطلاب المتشابهين في مجموعات منفصلة  بالتالي فهم مميزات كل مجموعة مما يساعد على قيادة وتوجيه كل مجموعة على حدى.                       

Bacteria and Risk Factors of Acne Vulgaris in Northern West Bank, Palestine

Bacterial species and risk factors were examined in acne vulgaris patients inNorthern West Bank. Samples were obtained from face and upper trunk lesions of138 patients (age: 15-34 years) at Dermatology clinics. Samples were incubatedin blood agar plates under aerobic and anaerobic conditions. Patients were askedto answer a questionnaire and all provided written informed consent. Bacteriawere isolated from 88% of the patients including Propionibacterium acnes,Staphylococcus epidermidis and Staphylococcus aureus. Risk factors mentionedby patients included emotional stress, high temperature, sweating and localpressure. Chocolate, nuts and fatty food were mentioned as exacerbating, andvegetables and fruits as ameliorating foods for their acne, respectively. Resultsshow high correlation between acne and bacteria with no relation between riskfactors and specific bacterial strains.Keywords: Acne vulgaris, Palestine, West Bank, risk facto

The transmission dynamics of Campylobacter jejuni among broilers in semi-commercial farms in Jordan

Campylobacter is the leading cause of foodborne bacterial gastroenteritis in humans worldwide, often associated with the consumption of undercooked poultry. In Jordan, the majority of broiler chicken production occurs in semi-commercial farms, where poor housing conditions and low bio-security are likely to promote campylobacter colonisation. While several studies provided estimates of the key parameters describing the within-flock transmission dynamics of campylobacter in typical high-income countries settings, these data are not available for Jordan and Middle-East in general. A Bayesian model framework was applied to a longitudinal dataset on Campylobacter jejuni infection in a Jordan flock to quantify the transmission rate of C. jejuni in broilers within the farm, the day when the flock first became infected, and the within-flock prevalence (WFP) at clearance. Infection with C. jejuni is most likely to have occurred during the first 8 days of the production cycle, followed by a transmission rate value of 0.13 new infections caused by one infected bird/day (95% CI 0.11–0.17), and a WFP at clearance of 34% (95% CI 0.24–0.47). Our results differ from published studies conducted in intensive poultry production systems in high-income countries but are well aligned with the expectations obtained by means of structured questionnaires submitted to academics with expertise on campylobacter in Jordan. This study provides for the first time the most likely estimates and credible intervals of key epidemiological parameters driving the dynamics of C. jejuni infection in broiler production systems commonly found in Jordan and the Middle-East and could be used to inform Quantitative Microbial Risk Assessment models aimed to assess the risk of human exposure/infection to campylobacter through consumption of poultry meat

Deposition of nanostructures derived from electrostatically stabilised TiO2 aqueous suspension onto a biocomposite

A nanostructure derived from TiO2 particle deposition onto a biocomposite surface derived from coir dust (CD) was developed to control degradation using a spray dry technique. To stabilise and reduce the size of dispersed particles, the TiO2 powder was prepared in deionised water at pH 10 and sonicated at 20kHz and 400W. The coir dust was obtained from coconut kernel waste and underwent drying treatment before it was mixed with polypropylene (PP) as the substrate. The suspension consisted of particles with an average size and zeta value of 285nm and -19.2mV, respectively. The suspension was spray dried onto a hot-pressed substrate (biocomposite) with a surface roughness between 0.23 and 1.57μm at ambient temperature. Scanning electron microscopy image analysis and Fourier transform infrared spectroscopy analysis indicated that the TiO2 particles were successfully deposited onto the substrate, shown by the existence of a carboxylic acid group (COOH) in the CD matrix. Moreover, the weight of the deposited substrate increased exponentially with deposition time compared to pure PP substrate. However, the deposition rate of TiO2 nanoparticles was limited by the ratio of the substrate surface roughness to particle diameter, as predicted by a previous study

Unveiling the noxious effect of polystyrene microplastics in aquatic ecosystems and their toxicological behavior on fishes and microalgae

Microplastic (MP) particles are considered noxious pollutants due to their presence in aquatic habitats at almost every level of the food chain. Thus, the entry of MP particles into marine waterbodies has triggered a common research interest. Until recently, the toxicity of polystyrene towards aquatic creatures in comparison to other polymers has not been widely investigated. This article provides an extensive overview of the occurrence of microplastic particles, the route of polystyrene (PS) in the aquatic ecosystem, the PS properties characterization, and its noxious effects on the aquatic biota, particularly fishes and microalgae. Alarming high levels of polystyrene were found in urban, coastal, and rural surface waters and sediments. The fast-screening technique began with a stereoscope to determine the polystyrene particles’ shape, size, and color on the organism. SEM and complemented by micro FTIR or Raman spectroscopy were used to evaluate MP’s polymer structures. The findings present evidence suggesting that polystyrene buildup in fish can have long-term and unknown consequences. Meanwhile, the presence of polystyrene on microalgae causes a decrease in chlorophyll concentration and photosynthetic activity, which may disrupt photosynthesis by interfering with the electron characters and leading to the production of reactive oxygen species (ROS)