Long-chain aliphatic wax esters isolated from the sponge Chalinula saudensis (Demospongia) along the Jeddah coast of the Red Sea

A esponja Chalinula saudensis ocorre ao longo da costa de Jeddah, Arabia Saudita, mas apenas recentemente foi isolada e identificada. No presente estudo a matéria orgânica total da esponja foi extraída por solventes e o extrato foi separado por partição sucessiva através do emprego de hexano e água, clorofórmio e água e finalmente t-butanol e água. A camada contendo clorofórmio foi então separada por cromatografia em sílica. Os resultados mostraram a presença de ésteres de quatro ácidos graxos de cadeira longa (C28H56O2, C30H60O2, C32H62O2 e C36H70O2), sendo que o segundo deles foi também identificado nos corais Millepora dichotoma e Millepora platyphylla. Não se tem evidência da presença dos demais compostos em outros organismos marinhos, embora haja relatos para ésteres semelhantes de cadeia longa, mas contendo diferentes cadeias alifáticas e diferentes pesos moleculares. Os compostos isolados em C. saudensis são geralmente ceras e sua presença na esponja tem importância não só nas rotas de biosíntese, mas servem como isolantes nas variações sazonais adversas.The sponge Chalinula saudensis, which occurs along the Jeddah coast, has only recently been isolated and identified. In this study, the total crude organic matter of the sponge was extracted by solvents. The total crude extract was further separated by partitioning it with hexane and water, then with water and chloroform, and finally with water and t-butanol. The chloroform layer was subjected to separation by preparative layer chromatography on silica. One fraction contained four long-chain fatty acid esters, C28H56O2, C30H60O2, C32H62O2 and C36H70 O2. The second ester, C30H60O2, has been identified in the fire corals Millepora dichotoma and Millepora platyphylla. The others have not previously been reported from marine organisms; however similar long-chain esters with different long aliphatic chains and with different molecular weights have been identified from other marine organisms. These compounds are normally waxy and their presence in Chalinula saudensis plays a vital role in the biosynthetic pathways. They also act as insulators against seasonal variations

Study of biochemical changes after plateletpheresis in healthy male donors

BACKGROUND: There is relatively little information about endogenous biochemical changes in a response to plateletpheresis in healthy donors. We aimed to investigate the changes in different biochemical parameters including glycemic status, insulin resistance, iron status, lipid profile and inflammatory markers after plateletpheresis in healthy male donors with normal glycemic status. METHODS: In this study we enrolled 10 male subjects. The glycemic status in all subjects was assessed using an oral glucose tolerance test pre- and post-plateletpheresis at different time intervals (1, 8 and 22 days). Different biochemical parameters including glucose, HbA1c, insulin, lipids, uric acid, transferrin, ferritin, C-reactive protein and insulin resistance were measured. Repeated ANOVA was utilized for the purpose of statistical comparison of means between different days. RESULTS: Fasting glucose, transferrin, cholesterol, triglycerides, HDL-C, and LDL-C were significantly altered (-3.9%, p<0.05; -2.7%, p<0.05; -3.9%, p<0.05; 23.9%, p<0.05; -5.5%, p<0.01; and -9.2%, p<0.05 respectively) at day 1 following plateletpheresis. There was a gradual reduction in HbA1c and ferritin levels during the time-course of the study, and by day 22, both were significantly lower (-2.0%, p<0.01; -18.1%, p<0.05 respectively) when compared to the pre-plateletpheresis levels. CONCLUSIONS: Post-plateletpheresis, several biochemical parameters may change significantly in healthy donors. The changes were particularly evident one and 22 days after donation. The potential effects of plateletpheresis need to be considered when interpreting biochemical tests

Coral Communities, in Contrast to Fish Communities, Maintain a High Assembly Similarity along the Large Latitudinal Gradient along the Saudi Red Sea Coast

The Saudi Arabian Red Sea coast is characterized by a strong environmental gradient from north (28.5°N) to south (16.5°N) with challenging conditions for coral growth particularly in the south (high temperature and nutrient input). We investigated whether assemblies of reef-building corals and the distribution of functional groups follow a latitudinal pattern in the Red Sea, and whether these changes affect the assembly structure of coral associated organisms (e.g. fishes). Functional groups were defined based on life-history traits and functional role. 13 reefs along the north-south gradient, including 5 potentially polluted reefs were investigated. Results showed a substantially weaker latitudinal shift in the assembly structure of coral communities than of fishes communities and of other benthic reef taxa. Competitive fast growing branching and tabular species (mainly Acropora), as well as rather stresstolerant slow growing bulky species (e.g. Porites, Goniastrea, Favites, Favia) were fairly evenly distributed along the north-south axis despite strong changes of environmental conditions. This seems on the one hand attributable to the high species richness within a given functional group (functional redundancy) and on the other hand to a high acclimatization / adaptation potential of some Red Sea coral species. The prime ecosystem service of the coral community, the provision of a habitat complex, is thereby maintained throughout the gradient. In contrast to the coral community, the assembly of the fish community shifts along the environmental gradient with higher abundances of small wrasses and butterfly fishes in the north, and overall higher abundance of fishes including large fishes in the south. This shift seems linked to higher food availability in the south. Altered assembly structures of coral communities were found in reefs close to a source of pollution with either an increased relative abundance of stresstolerant species or a general decrease of coral abundance, latter case accompanied by a substantial reduction in fish abundance

Defining criteria for disease activity states in systemic juvenile idiopathic arthritis based on the systemic Juvenile Arthritis Disease Activity Score

Objective To develop and validate cutoff values in the systemic Juvenile Arthritis Disease Activity Score 10 (sJADAS10) that distinguish the states of inactive disease (ID), minimal disease activity (MiDA), moderate disease activity (MoDA), and high disease activity (HDA) in children with systemic juvenile idiopathic arthritis (sJIA), based on subjective disease state assessment by the treating pediatric rheumatologist. Methods The cutoffs definition cohort was composed of 400 patients enrolled at 30 pediatric rheumatology centers in 11 countries. Using the subjective physician rating as an external criterion, 6 methods were applied to identify the cutoffs: mapping, calculation of percentiles of cumulative score distribution, Youden index, 90% specificity, maximum agreement, and ROC curve analysis. Sixty percent of the patients were assigned to the definition cohort and 40% to the validation cohort. Cutoff validation was conducted by assessing discriminative ability. Results The sJADAS10 cutoffs that separated ID from MiDA, MiDA from MoDA, and MoDA from HDA were ≤ 2.9, ≤ 10, and > 20.6. The cutoffs discriminated strongly among different levels of pain, between patients with or without morning stiffness, and between patients whose parents judged their disease status as remission or persistent activity/flare or were satisfied or not satisfied with current illness outcome. Conclusion The sJADAS cutoffs revealed good metrologic properties in both definition and validation cohorts, and are therefore suitable for use in clinical trials and routine practice

Predictors and outcomes of extubation failures in a pediatric intensive care unit: A retrospective study

الملخص: أهداف البحث: تهدف هذه الدراسة إلى تحديد معدل فشل نزع الأنبوب في وحدة العناية المركزة للأطفال والتأكيد على المسببات وعوامل الخطر المرتبطة بها والنتيجة. طريقة البحث: أجرينا دراسة بأثر رجعي على 335 مريضا من الأطفال الذين تم إدخالهم إلى مستشفى جامعة الملك عبد العزيز في الفترة من 2018 إلى 2020، وتتراوح أعمارهم بين شهر واحد و14 عاما، ويحتاجون إلى تهوية ميكانيكية غزوية لمدة تزيد عن 24 ساعة. تم تحديد جاهزية نزع الأنبوب للمرضى من قبل طبيب العناية المركزة للأطفال المعالج بناء على الحالة السريرية ومعايير الاستعداد لنزع الأنبوب. النتائج: ومن بين مجموعة مكونة من 335 مريضا، واجه 42 فردا مشكلات أثناء عملية نزع الأنبوب، وبلغت ذروتها بمعدل فشل قدره 12.5%. كانت أمراض القلب والأوعية الدموية (42.9٪) هي حالة القبول الأولية الملحوظة إلى حد كبير لدى مرضى فشل نزع الأنبوب. كان المرضى الأصغر سنا مرتبطين بشكل كبير بحدوث فشل نزع الأنبوب مقارنة بالمرضى الذين تم نزع أنبوبهم بنجاح مع ارتفاع معدل الوفيات المتوقع ودرجة معيار خطر وفيات الأطفال 3. علاوة على ذلك، لوحظت فترات الإقامة الطويلة في وحدة العناية المركزة ومتطلبات أطول للتهوية الميكانيكية قبل نزع الأنبوب لدى مرضى فشل نزع الأنبوب المرتبطين بمعدل وفيات مرتفع. ومن المثير للاهتمام أن إعطاء الديكساميثازون قبل عملية نزع الأنبوب خفف بشكل كبير من خطر فشل نزع الأنبوب لدى المرضى. الاستنتاجات: توضح دراستنا ارتفاع معدل فشل نزع الأنبوب لدى المرضى الأصغر سنا الذين يحتمل أن يكونوا مرتبطين بإقامات أطول في وحدة العناية المركزة، ومتطلبات طويلة الأمد للتهوية الميكانيكية قبل نزع الأنبوب، وحالة التشخيص الأولية. وقد لوحظ أن الديكساميثازون فعال في التخفيف من حدوث فشل نزع الأنبوب. هناك حاجة إلى مزيد من البحث الذي يتضمن تصميم دراسة أكثر جوهرية قائمة على الأدلة لإثبات العوامل المذكورة كمنبئات لفشل نزع الأنبوب ووضع استراتيجيات للحد منه. Abstract: Objectives: This study was aimed at determining the extubation failure (EF) rate in a pediatric intensive care unit (PICU), and assessing the etiology, associated risk factors, and outcomes. Methods: We conducted a retrospective study on 335 pediatric patients admitted to King Abdulaziz University Hospital between 2018 and 2020, ranging in age from 1 month to 14 years, who required invasive mechanical ventilation (MV) for >24 h. Extubation readiness was determined by the attending pediatric intensive care physician, according to the patients’ clinical status and extubation readiness criteria. Results: In the cohort of 335 patients, 42 experienced issues during extubation (failure rate, 12.5%). Cardiovascular disease (42.9%) was the main primary admission condition in patients with EF. Younger age (median, interquartile range [IQR]: 4, 1.38–36 months) was strongly associated with EF compared with successful extubation (median, IQR: 12, 2–48; p = 0.036), and with a high predicted mortality rate (10.9%; p < 0.001) and Pediatric Risk of Mortality III (PRISM) score (13; p < 0.001). Furthermore, prolonged ICU stay (25.5 days; p < 0.001) and longer MV requirements (4 days; p < 0.001) before extubation in patients with EF were associated with a high mortality rate (∼12%; p < 0.001). Interestingly, dexamethasone administration before extubation significantly alleviated EF risk (28.3%; p < 0.001). Conclusion: A higher EF rate in younger patients may potentially be associated with longer ICU stays, prolonged MV requirements before extubation, and the primary diagnostic condition. Dexamethasone effectively alleviated EF incidence. Further research with a rigorous evidence-based study design is necessary to substantiate the factors identified as predictors of EF and to develop strategies to avoid EF