PFOS-elicited metabolic perturbation in liver and fatty acid metabolites in testis of adult mice

IntroductionMultiple factors can contribute to sub-fecundity, including genetics, lifestyle, and environmental contaminants. PFASs are characterized as “forever chemicals” due to their ubiquitous contamination and their persistence in the environment, wildlife, and humans. Numerous studies have demonstrated that PFAS exposure adversely affects multiple bodily functions, including liver metabolism and gonadal function. It is unclear, however, how the disruption of hepatic fatty acid metabolism affects testicular function.MethodsIn this study, male mice were administered 0.3 and 3 μg/g body weight of PFOS for 21 days.ResultsOur data showed that PFOS exposure caused hepatic steatosis, as evidenced by significant increases in triglyceride levels, expression of ATP-citrate lyase, and fatty acid synthase, as well as fasting insulin levels. PFOS perturbed the expression levels of hepatokines, of which fibroblast growth factor-21 (Fgf-21), leukocyte cell-derived chemotaxin-2 (Lect-2), and retinol-binding protein-4 (Rbp-4) were significantly reduced, whereas angiopoietin-like 4 (Angptl4) was noticeably increased. While Rbp-4 and Fgf-21 are known to contribute to spermatogenesis and testosterone synthesis. In PFOS-exposed groups, testicular ATP, and testosterone decreased significantly with a significant increase in the expression of peroxisome proliferator-activated receptor-coactivator 1α. Mass spectrophotometry imaging revealed the localization of PFOS in testes, along with significant increases in fatty acid metabolites. These included arachidonic acid, dihomo-α-linolenic acid, dihomo-γ-linolenic acid, oxidized ceramide, diacylglycerol, phosphatidylcholine, and phosphatidylethanolamine, which are associated with inflammation and post-testicular causes of infertility.DiscussionThis study revealed potential links between PFOS-elicited changes in hepatic metabolism and their impacts on testicular biology. This study provides insights into alternative targets elicited by PFOS that can be used to develop diagnostic and therapeutic strategies for improving testicular dysfunction

「回首．動情．傳承」長者生命故事計劃

嶺南大學亞太老年學研究中心獲華人永遠墳場管理委員會（「華永會」）資助為期一年的「回首．動情．傳承」長者生命故事計劃(「計劃」)。此計劃旨在讓青年人認識長者生命經驗，學習克服困難與挫折以提升抗逆力，建立正向人生觀。 近年，主流媒體經常批評年輕人的負面人生觀，例如：「躺平主義」、「享樂主義」、「犬儒心態」等，亦不時看到青年人輕生的新聞。我們曾在大學內處理過不少受情緒困擾及企圖自殺的個案，與學生深入交流後，發現他們面對着沉重的學業壓力、財政困難或複雜的家庭關係，內心充滿掙扎不安。 此計劃讓嶺大學生與長者導師進行深度的對談，透過了解長者走過的路、他們經歷過的挫折和教訓，給予年輕人生命的啟示。如果我們以旅遊比喻人生，長者就像環遊世界的資深背包客，即使大家遊覽不同的地點、觀賞過不同的風景，他們總能夠分享一些旅遊的心得，讓新手遊客走少一點冤枉路，或領悟到旅遊的樂趣和意義。長者亦可以藉由敍述人生片段回顧他們生命中的故事，學習接納過去，增加自我認同感。青年人創作生命教育書冊，將長者積極的人生觀傳給年輕一代，並藉此鼓勵其他長者豁達地度過餘年。 我們於2022年初招募嶺南大學學生接受「生命故事敍述」培訓，內容包括：本港的人口老化現象、敍述治療理論、與長者溝通的技巧及模擬實踐練習等，以裝備同學的知識和技巧。本中心再向屯門、元朗區的長者機構發邀請信，誠邀長者擔任生命導師接受訪問。 嶺大安排同學以兩人一組的小隊形式，於2022年6至7月期間前往長者中心、日間護理中心、嶺南大學或長者家中，與十二位長者進行深入訪談。訪談結束後，同學根據訪談的內容，為長者書寫他們獨特的生命故事。例如在人離鄉賤的異國環境下，努力打拼事業的Alfred；堅持不懈持續進修的淑芹和馮春林；即使沒機會求學，仍憑一雙巧手闖出一片天的譚惠；在文化大革命的漩渦中，憑着熱忱而改變命運的蘭英；還有為家人無私奉獻的鳳群、歐婆婆、雅芳及細女；離鄉別井勇闖異地的阿美和阿水；即使被家人賣去做「妹仔」，仍能以「阿Q精神」面對的諒餘。 為保障長者的私隱權益，本書內所有刊登之故事皆經過受訪者或社工審閱，部份受訪者選擇以化名的形式來分享自己的故事，我們亦移除了部份敏感的個人資料。https://commons.ln.edu.hk/apias_guide/1008/thumbnail.jp

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

圓桌討論 : 網絡出版 = Roundtable on online publication

適逢《文化研究@嶺南》已出版至第五十期，文化研究系想藉此機會回顧與前瞻《文化研究@嶺南》以及其他網絡出版、重要性、功能、目標定位、未來發展等議題上暢所欲言

Radiomics from Various Tumour Volume Sizes for Prognosis Prediction of Head and Neck Squamous Cell Carcinoma: A Voted Ensemble Machine Learning Approach

Background: Traditionally, cancer prognosis was determined by tumours size, lymph node spread and presence of metastasis (TNM staging). Radiomics of tumour volume has recently been used for prognosis prediction. In the present study, we evaluated the effect of various sizes of tumour volume. A voted ensemble approach with a combination of multiple machine learning algorithms is proposed for prognosis prediction for head and neck squamous cell carcinoma (HNSCC). Methods: A total of 215 HNSCC CT image sets with radiotherapy structure sets were acquired from The Cancer Imaging Archive (TCIA). Six tumour volumes, including gross tumour volume (GTV), diminished GTV, extended GTV, planning target volume (PTV), diminished PTV and extended PTV were delineated. The extracted radiomics features were analysed by decision tree, random forest, extreme boost, support vector machine and generalized linear algorithms. A voted ensemble machine learning (VEML) model that optimizes the above algorithms was used. The receiver operating characteristic area under the curve (ROC-AUC) were used to compare the performance of machine learning methods, including accuracy, sensitivity and specificity. Results: The VEML model demonstrated good prognosis prediction ability for all sizes of tumour volumes with reference to GTV and PTV with high accuracy of up to 88.3%, sensitivity of up to 79.9% and specificity of up to 96.6%. There was no significant difference between the various target volumes for the prognostic prediction of HNSCC patients (chi-square test, p > 0.05). Conclusions: Our study demonstrates that the proposed VEML model can accurately predict the prognosis of HNSCC patients using radiomics features from various tumour volumes

Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally

The surgical safety checklist and patient outcomes after surgery: a prospective observational cohort study, systematic review and meta-analysis

© 2017 British Journal of Anaesthesia Background: The surgical safety checklist is widely used to improve the quality of perioperative care. However, clinicians continue to debate the clinical effectiveness of this tool. Methods: Prospective analysis of data from the International Surgical Outcomes Study (ISOS), an international observational study of elective in-patient surgery, accompanied by a systematic review and meta-analysis of published literature. The exposure was surgical safety checklist use. The primary outcome was in-hospital mortality and the secondary outcome was postoperative complications. In the ISOS cohort, a multivariable multi-level generalized linear model was used to test associations. To further contextualise these findings, we included the results from the ISOS cohort in a meta-analysis. Results are reported as odds ratios (OR) with 95% confidence intervals. Results: We included 44 814 patients from 497 hospitals in 27 countries in the ISOS analysis. There were 40 245 (89.8%) patients exposed to the checklist, whilst 7508 (16.8%) sustained ≥1 postoperative complications and 207 (0.5%) died before hospital discharge. Checklist exposure was associated with reduced mortality [odds ratio (OR) 0.49 (0.32–0.77); P\u3c0.01], but no difference in complication rates [OR 1.02 (0.88–1.19); P=0.75]. In a systematic review, we screened 3732 records and identified 11 eligible studies of 453 292 patients including the ISOS cohort. Checklist exposure was associated with both reduced postoperative mortality [OR 0.75 (0.62–0.92); P\u3c0.01; I2=87%] and reduced complication rates [OR 0.73 (0.61–0.88); P\u3c0.01; I2=89%). Conclusions: Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine

Critical care admission following elective surgery was not associated with survival benefit: prospective analysis of data from 27 countries

This was an investigator initiated study funded by Nestle Health Sciences through an unrestricted research grant, and by a National Institute for Health Research (UK) Professorship held by RP. The study was sponsored by Queen Mary University of London