Responses of Mammalian Cells to Membrane-Disrupting Peptides.

Responses of cultured mouse fibroblasts, human erythrocytes, bovine erythrocytes, and liposomes with different phosphatidylcholine (PC) and sphingomyelin (SPM) ratios to both natural and synthetic lytic peptides were characterized. Peptide-induced morphological alterations of the plasma membrane of cells were examined by various light microscopic techniques and scanning electron microscopy (SEM). The ability of natural and synthetic peptides to kill cells and cause increased permeability of liposomes was evaluated using Trypan Blue (TB) dye exclusion assay and fluorescent dye leakage assay, respectively. Differential interference contrast microscopy, SEM, and fluorescence studies revealed characteristic structural and lipid changes in the plasma membrane of lytic peptide-treated fibroblasts, and these alterations were accompanied by simultaneous changes in the cell permeability as indicated by the uptake of TB. Formation of membrane vesicles, composed primarily of lipids, was demonstrated in cells treated with a low lethal dose of melittin and eventually resulted in the liberation of membrane lipids. SEM revealed that much of the plasma membrane was lost by 5 minutes following peptide exposure. Confocal microscopy confirmed the translocation of membrane proteins from the cell surface to cytoplasmic areas in peptide-treated cells. A fluorescently labeled peptide was used to demonstrate the reaction of the peptides with the plasma membrane. The measurements of the ability of natural and synthetic peptides to kill fibroblasts allowed classification of these peptides into four groups. The results also suggested that peptide length and substitution of glycine for alanine affected the potency of synthetic peptides. Differential susceptibility of different cell types to destruction by the same peptides was demonstrated in mouse fibroblasts and human and bovine erythrocytes. These peptides were less efficient in lysing erythrocytes than in destroying fibroblasts. This difference in activity was possibly due to the higher content of membrane SPM in the resistant RBCs. Lytic peptides demonstrated less ability to permeate liposomes composed of 70% SPM. Synergistic effects were demonstrated in mammalian cells using weak lytic peptides and exogenous phospholipases. The effect was dependant upon the phospholipid composition of the target cells. Cell susceptibility and synergy between peptides and membrane reactive enzymes are important factors in the selection of therapeutic peptides

Explore the Common Measuring Errors and Quantify the Errors of New Noise Barrier Designs for Mitigating Traffic Noise

Background and Objective: Noise pollution from road traffic has been a persistent problem in Hong Kong and there has been increasing attention on its association with risks to human health and well-being. Much research has been done in searching for an improved design of noise barriers as a direct noise abatement solution. Reflecting on the experience of supervising a recent acoustic barrier design project involving open field tests and using prototypes, this paper aims to explore the common errors in working and performing experiments with scaled models. Materials and Methods: The project team conducted tests in an open field for the three designs of noise barriers. Amplifiers were used to mimic traffic noise of 800-1200 kHz. The 3-D printing was deployed to make templates for casting concrete panels for their noise barrier models. Results: Test results showed some inconsistency with the teamʼs expectations. All models were capable of reducing sound at all the measurement points of different heights. At lower heights, the reduction was 4 to 11 dB(A), At higher heights, the reduction decreased to only 3 to 5 dB(A). When the data were plotted on a graph, sound measurements of all three designs showed a non-linear path by height. Therefore, it was difficult for the team to draw convincing conclusions from them. There are lessons learned at every stage of the project, from idea formulation to prototyping and experimentation. Conclusion: Hopefully, these lessons and suggested resolves will help in the future, especially those involving the use and testing of scale model prototypes

Piperacillin/tazobactam Induced Myelosuppression

Neutropenia, secondary to immune destruction or maturation arrest, is the most commonly described adverse haematological effect of beta-lactam antibiotics. We describe a case of reversible pancytopenia, with evidence of hypocellular marrow, after a prolonged course of piperacillin/tazobactam for 26 days

Mindfulness-based cognitive therapy v. group psychoeducation for people with generalised anxiety disorder: randomised controlled trial

Background: Research suggests that an 8-week mindfulness-based cognitive therapy (MBCT) course may be effective for generalised anxiety disorder (GAD). Aims: To compare changes in anxiety levels among participants with GAD randomly assigned to MBCT, cognitive–behavioural therapy-based psychoeducation and usual care. Method: In total, 182 participants with GAD were recruited (trial registration number: CUHK_CCT00267) and assigned to the three groups and followed for 5 months after baseline assessment with the two intervention groups followed for an additional 6 months. Primary outcomes were anxiety and worry levels. Results: Linear mixed models demonstrated significant group × time interaction (F(4,148) = 5.10, P = 0.001) effects for decreased anxiety for both the intervention groups relative to usual care. Significant group × time interaction effects were observed for worry and depressive symptoms and mental health-related quality of life for the psychoeducation group only. Conclusions: These results suggest that both of the interventions appear to be superior to usual care for the reduction of anxiety symptoms

A Brief Mindfulness-Based Family Psychoeducation Intervention for Chinese Young Adults With First Episode Psychosis: A Study Protocol

Family psychoeducation (FPE) has been recommended as a major component in the treatment of psychosis. Many previous studies have implemented an intensive program design that often only emphasized improvements in patients’ illness outcomes but the benefits for caregivers were limited. There have been calls for a time-limited but cost-effective FPE program to mitigate the looming reality of the suffering of people with psychosis and their families. A Brief Mindfulness-Based Family Psychoeducation for psychosis program is developed to reduce caregivers’ burden and promote young adult’s recovery. A randomized controlled trial will be conducted to compare this intervention with an ordinary FPE intervention. Both arms will involve six sessions, with a total contact time of 12 h. 300 caregivers of young adults who have experienced first episode psychosis within last 3 years will be recruited. Program effectiveness will be assessed by comparing outcomes measuring the caregivers’ burden, mental health symptoms, positive well-being, and the young adult’s mental health symptoms during the study and at 9-month post-randomization. The role of expressed emotions, interpersonal mindfulness, and non-attachment in mediating these outcomes will be explored. An additional qualitative approach Photovoice is selected to explore the complex family experiences and the benefits of mindfulness from the caregivers’ personal perspectives.Trial Registration: The trial is registered with the United States Clinical Trials Registry (ClinicalTrials.gov): NCT03688009

Fractionation and extraction of bio-oil for production of greener fuel and value-added chemicals : Recent advances and future prospects

Bio-oil is a highly valuable product derived from biomass pyrolysis which could be used in various downstream applications upon appropriate upgrading and refining. Extraction and fractionation are two promising methods to upgrade bio-oil by separating the complex mixture of bio-oil compounds into distinct fine chemicals and fractions enriched in certain classes of chemical compounds. In this review, various extraction techniques for bio-oil (organic solvent extraction, water extraction, supercritical fluid extraction, distillation, adsorption, chromatography, membrane, electrosorption and ionic liquid extraction), their associated features (extraction mechanisms involved, advantages and disadvantages), the characteristics of bio-oil extracts and their applications are presented and critically discussed. It was revealed that the most promising technique is via organic solvent extraction. Furthermore, the technological gaps and bottlenecks for each separation techniques are disclosed, as well as the overall challenges and future prospects of oil palm biomass-based bio-oil value chain. This review aims to provide key insights on bio-oil upgrading via extraction and fractionation, and a proposed way forward via technology integration in establishing a sustainable palm oil mill-based biorefinery

「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

Gene Expression Profiling on the Molecular Action of Danshen-Gegen Formula in a Randomized Placebo-Controlled Trial of Postmenopausal Women with Hypercholesterolemia

The Danshen-Gegen formula (DG) is a traditional Chinese herbal formula which has long been used to treat cardiovascular disease. DG was found to be a cardiovascular tonic in our recent research. However, a comprehensive investigation of the molecular mechanism of DG in cardiovascular disease has not been performed. The aim of this study was to clarify the transcriptional profiling of genes modulated by DG on postmenopausal women by using DNAmicroarray technology. We obtained 29 whole blood samples both from DG-treated and placebo-treated subjects. Blood lipid profile and intima-media thickness (IMT) were measured. Affymetrix GeneChip was used to identify differentially expressed genes (DEGs), followed by validation by the real-time PCR method. The results showed that DG-treated group has a significant improvement in IMT and lipid profile as compared to placebo-treated group. For the genomic study, the DG-treated group has a higher number of DEGs identified as compared to the placebo-treated group. Two important biological processes of “regulation of systemic arterial blood pressure by hormone” and “regulation of smooth muscle proliferation” have been identified by GePS in the DG-treated group. No significant biological process and cellular components were identified in the placebo-treated group. This genomic study on the molecular action of DG in postmenopausal women gathered sufficient molecular targets and pathways to reveal that DG could improve neointima thickening and hypertension

Deleted in Liver Cancer 1 (DLC1) Negatively Regulates Rho/ROCK/MLC Pathway in Hepatocellular Carcinoma

Aims: Deleted in liver cancer 1 (DLC1), a member of RhoGTPase activating protein (GAP) family, is known to have suppressive activities in tumorigenicity and cancer metastasis. However, the underlying molecular mechanisms of how DLC1 suppresses cell motility have not been fully elucidated. Rho-kinase (ROCK) is an immediate down-stream effector of RhoA in mediating cellular cytoskeletal events and cell motility. In the present study, we aimed to investigate the effects of DLC1 on Rho/ROCK signaling pathway in hepatocellular carcinoma (HCC). Methodology/Principal Findings: We demonstrated that DLC1 negatively regulated ROCK-dependent actomyosin contractility. From immumofluorescence study, we found that ectopic expression of DLC1 abrogated Rho/ROCK-mediated cytoskeletal reorganization including formation of stress fibers and focal adhesions. It also downregulated cortical phosphorylation of myosin light chain 2 (MLC2). These inhibitory events by DLC1 were RhoGAP-dependent, as RhoGAP-deficient mutant of DLC1 (DLC1 K714E) abolished these inhibitory events. In addition, from western study, DLC1 inhibited ROCK-related myosin light chain phosphatase targeting unit 1 (MYPT1) phosphorylation at Threonine 853. By examining cell morphology under microscope, we found that ectopic expression of dominant-active ROCK released cells from DLC1-induced cytoskeletal collapse and cell shrinkage. Conclusion: Our data suggest that DLC1 negatively regulates Rho/ROCK/ MLC2. This implicates a ROCK-mediated pathway of DLC1 in suppressing metastasis of HCC cells and enriches our understanding in the molecular mechanisms involved in the progression of hepatocellular carcinoma. © 2008 Wong et al.published_or_final_versio