1.Perioperative immune dynamics and clinical outcomes in patients undergoing on-pump cardiac surgery
Zhiyuan CHENG ; Xinyi LIAO ; Juan WU ; Ping YANG ; Tingting WANG ; Qinjuan WU ; Wentong MENG ; Zongcheng TANG ; Jiayi SUN ; Jia TAN ; Jing LIN ; Dan LUO ; Hao WANG ; Chaonan LIU ; Jiyue XIONG ; Liqin LING ; Jing ZHOU ; Lei DU
Chinese Journal of Blood Transfusion 2026;39(1):31-43
Objective: To characterize perioperative dynamic changes in immune-cell phenotypes and inflammatory cytokines in patients undergoing CPB (cardiopulmonary bypass) cardiac surgery, and to explore their associations with postoperative outcomes. Methods: In this prospective cohort study, 120 adult patients who underwent elective cardiac surgery under CPB at West China Hospital from May 2022 to March 2023 were enrolled. Perioperative immune-cell phenotypes and concentrations of 40 inflammation-related cytokines were measured. The primary outcomes were the sequential organ failure assessment (SOFA) score at 24 h after surgery and ΔSOFA (the peak SOFA score within 48 h after surgery minus the preoperative SOFA score). Secondary outcomes included major adverse cardiovascular events (MACE), acute kidney injury (AKI), respiratory failure, severe liver injury, and infection. Results: The mean age of enrolled patients was 57±10 years. Of these, 52% (62/120) were male and 90% (108/120) underwent valve surgery. During the rewarming to the end of CPB, neutrophil counts rapidly increased (7.39×10
/L vs preoperative 3.07×10
/L, P<0.001), with significant upregulation of CD11b (7.30×10
/L vs preoperative 3.05×10
/L, P<0.001) and CD54 (7.15×10
/L vs preoperative 2.99×10
/L, P<0.001). Lymphocyte counts increased at the end of CPB (1.75×10
/L vs preoperative 1.12×10
/L, P<0.001) but decreased significantly at 24 h after surgery (0.59×10
/L vs preoperative 1.12×10
/L, P<0.001). Plasma analysis showed that multiple pro-inflammatory cytokines increased during CPB and remained elevated up to 24 h after surgery; five chemokines and the anti-inflammatory cytokine IL-10 peaked at the end of CPB. The SOFA score increased from 1 (1, 2) preoperatively to 7 (5, 10) at 24 h after surgery, with a ΔSOFA of 6 (4, 8). Within 30 days after surgery, 48 patients (40.0%) developed AKI, 17 (14.2%) developed infection, 4 (3.3%) developed severe liver injury, 3 (2.5%) developed respiratory failure, and 3 (2.5%) experienced MACE. During the 2-year follow-up, 8 patients (6.7%) experienced MACE and 5 (4.2%) died. Conclusion: Multi-organ dysfunction is common after cardiac surgery under CPB (median ΔSOFA, 6), accompanied by perioperative activation of multiple immune-cell subsets and upregulation of pro-inflammatory, anti-inflammatory, and chemotactic mediators. This study provides data-driven evidence and research clues for further investigation of the associations between CPB-related immune perturbations and postoperative organ dysfunction and clinical outcomes.
2.Finite element analysis of stress distribution of anchors at different implantation depths under different bone density conditions in rotator cuff tears
Meng WANG ; Tan LU ; Minjie LI ; Zhicheng LIU ; Xiaoyong GUO
Chinese Journal of Tissue Engineering Research 2026;30(3):561-569
BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5<T value<-1.0)and osteoporosis(T value<-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.
3.Finite element analysis of stress distribution of anchors at different implantation depths under different bone density conditions in rotator cuff tears
Meng WANG ; Tan LU ; Minjie LI ; Zhicheng LIU ; Xiaoyong GUO
Chinese Journal of Tissue Engineering Research 2026;30(3):561-569
BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5<T value<-1.0)and osteoporosis(T value<-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.
4.The Mechanisms of Neurotransmitters and Their Receptors in Exercise Central Fatigue
Lu-Lu GUAN ; Bo-Te QI ; Du-Shuo FENG ; Jing-Wang TAN ; Meng CAO ; Yu ZOU
Progress in Biochemistry and Biophysics 2025;52(6):1321-1336
Exercise fatigue is a complex physiological and psychological phenomenon that includes peripheral fatigue in the muscles and central fatigue in the brain. Peripheral fatigue refers to the loss of force caused at the distal end of the neuromuscular junction, whereas central fatigue involves decreased motor output from the primary motor cortex, which is associated with modulations at anatomical sites proximal to nerves that innervate skeletal muscle. The central regulatory failure reflects a progressive decline in the central nervous system’s capacity to recruit motor units during sustained physical activity. Emerging evidence highlights the critical involvement of central neurochemical regulation in fatigue development, particularly through neurotransmitter-mediated modulation. Alterations in neurotransmitter release and receptor activity could influence excitatory and inhibitory signal pathways, thus modulating the perception of fatigue and exercise performance. Increased serotonin (5-HT) could increase perception of effort and lethargy, reduce motor drive to continue exercising, and contribute to exercise fatigue. Decreased dopamine (DA) and noradrenaline (NE) neurotransmission can negatively impact arousal, mood, motivation, and reward mechanisms and impair exercise performance. Furthermore, the serotonergic and dopaminergic systems interact with each other; a low 5-HT/DA ratio enhances motor motivation and improves performance, and a high 5-HT/DA ratio heightens fatigue perception and leads to decreased performance. The expression and activity of neurotransmitter receptors would be changed during prolonged exercise to fatigue, affecting the transmission of nerve signals. Prolonged high-intensity exercise causes excess 5-HT to overflow from the synaptic cleft to the axonal initial segment and activates the 5-HT1A receptor, thereby inhibiting the action potential of motor neurons and affecting the recruitment of motor units. During exercise to fatigue, the DA secretion is decreased, which blocks the binding of DA to D1 receptor in the caudate putamen and inhibits the activation of the direct pathway of the basal ganglia to suppress movement, meanwhile the binding of DA to D2 receptor is restrained in the caudate putamen, which activates the indirect pathway of the basal ganglia to influence motivation. Furthermore, other neurotransmitters and their receptors, such as adenosine (ADO), glutamic acid (Glu), and γ‑aminobutyric acid (GABA) also play important roles in regulating neurotransmitter balance and fatigue. The occurrence of central fatigue is not the result of the action of a single neurotransmitter system, but a comprehensive manifestation of the interaction between multiple neurotransmitters. This review explores the important role of neurotransmitters and their receptors in central motor fatigue, reveals the dynamic changes of different neurotransmitters such as 5-HT, DA, NE, and ADO during exercise, and summarizes the mechanisms by which these neurotransmitters and their receptors regulate fatigue perception and exercise performance through complex interactions. Besides, this study presents pharmacological evidence that drugs such as agonists, antagonists, and reuptake inhibitors could affect exercise performance by regulating the metabolic changes of neurotransmitters. Recently, emerging interventions such as dietary bioactive components intake and transcranial electrical stimulation may provide new ideas and strategies for the prevention and alleviation of exercise fatigue by regulating neurotransmitter levels and receptor activity. Overall, this work offers new theoretical insights into the understanding of exercise central fatigue, and future research should further investigate the relationship between neurotransmitters and their receptors and exercise fatigue.
5.Meta-analysis of association between atmospheric ozone exposure and atherosclerotic cardiovascular disease
Bingqian WANG ; Teng YANG ; Shuting XIE ; Meng TAN ; Guoxing LI ; Jing HUANG
Journal of Environmental and Occupational Medicine 2025;42(6):740-747
Background Atherosclerotic cardiovascular disease (ASCVD) is a major contributor to the global burden of cardiovascular diseases. However, evidence from meta-analyses on the association between ambient ozone exposure and ASCVD risk remains relatively insufficient. Objective To explore the epidemiological association between ambient ozone exposure and ASCVD, providing scientific evidence for ASCVD prevention and control from the perspective of environmental risk factor management. Methods We systematically searched PubMed, Web of Science, Embase, the Cochrane Library, CNKI, Wanfang Database, CBM, and VIP for published epidemiological studies on the relationship between ambient ozone exposure and ASCVD from January 2007 to December 2023. We performed quality assessment and data extraction of the included studies, and utilized meta-analysis to evaluate the effects of short-term and long-term ozone exposure on different ASCVD outcomes, including mortality and incidence of ischemic heart disease (IHD) and ischemic stroke (IS). Results A total of 24 studies were included based on a set of predetermined eligibility criteria. The meta-analysis results indicated that short-term ozone exposure was associated with an increased risk of ASCVD mortality and incidence. Specifically, short-term ozone exposure was significantly associated with an elevated risk of IHD mortality (combined RR=1.011, 95%CI: 1.008, 1.015; P < 0.05). Additionally, short-term ozone exposure was significantly linked to increased IS mortality (combined RR=1.005, 95%CI: 1.003, 1.008; P < 0.05) and incidence (combined RR=1.015, 95%CI: 1.003, 1.027; P < 0.05). Conclusion Short-term exposure to ambient ozone significantly elevates acute cardiovascular disease risk. However, the epidemiological association between long-term ozone exposure and ASCVD remains inconclusive. Future high-quality cohort studies with refined exposure assessment methods are warranted to elucidate the chronic cardiovascular effects of ozone exposure.
6.Pathogenesis of Chronic Heart Failure with Anxiety and Depression and Therapeutic Mechanisms of Bupleuri Radix-based Formulas from Theory of Shaoyang Pivot
Duoting TAN ; Kun LIAN ; Hao LIANG ; Lichong MENG ; Zhixi HU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(16):156-164
Chronic heart failure (CHF), as the terminal stage of various cardiovascular diseases, is characterized by a prolonged clinical course and recurrent exacerbations. The coexistence of CHF with anxiety and depression falls under the category of psycho-cardiological diseases. Studies have demonstrated that anxiety and depression are closely associated with adverse outcomes including elevated risks of cardiovascular events and increased mortality in CHF patients. The complex pathogenesis poses challenges to modern medical treatments, which often face limited efficacy and concurrent side effects. According to the theory of Shaoyang Pivot in traditional Chinese medicine (TCM), this paper elucidates that obstructed Shaoyang Pivot—manifested as Qi transformation disorder, dysregulated fluid metabolism, and abnormal distribution of ministerial fire-serves as a critical pathological basis for CHF with anxiety and depression. Bupleuri Radix-based Formulas, such as Xiao Chaihu Tang, Chaihu Guizhi Tang, and Chaihu Jia Longgu Muli Tang, aim to harmonize lesser Yang to restore the Qi transformation, activate Yang to promote water excretion, and redistribute ministerial fire, thus effectively alleviating pathological states such as Qi stagnation, blood stasis, water retention, and phlegm-fire disturbing the heart in CHF patients with anxiety and depression. Consequently, they mitigate symptoms of this psycho-cardiological disease. Mechanism studies have revealed that Bupleuri Radix-based formulas exhibit multi-target effects, including modulation of neurotransmitters, suppression of inflammatory responses, regulation of lipid metabolism, protection of cardiomyocytes, and improvement of the endothelial function. By interpreting the TCM pathogenesis of CHF with anxiety and depression from the theory of Shaoyang Pivot, this paper delves into the therapeutic principles and mechanisms of Bupleuri Radix-based formulas, providing a theoretical foundation for optimizing TCM diagnosis and treatment strategies for psycho-cardiological diseases.
7.Risk and protective factors associated with adolescent depression in Singapore: a systematic review.
Wei Sheng GOH ; Jun Hao Norman TAN ; Yang LUO ; Sok Hui NG ; Mohamed Sufyan Bin Mohamed SULAIMAN ; John Chee Meng WONG ; Victor Weng Keong LOH
Singapore medical journal 2025;66(1):2-14
INTRODUCTION:
Adolescent depression is prevalent, and teen suicide rates are on the rise locally. A systemic review to understand associated risk and protective factors is important to strengthen measures for the prevention and early detection of adolescent depression and suicide in Singapore. This systematic review aims to identify the factors associated with adolescent depression in Singapore.
METHODS:
A systematic search on the following databases was performed on 21 May 2020: PubMed, EMBASE and PsycINFO. Full texts were reviewed for eligibility, and the included studies were appraised for quality using the Newcastle Ottawa Scale. Narrative synthesis of the finalised articles was performed through thematic analysis.
RESULTS:
In total, eight studies were included in this review. The four factors associated with adolescent depression identified were: (1) sociodemographic factors (gender, ethnicity); (2) psychological factors, including childhood maltreatment exposure and psychological constructs (hope, optimism); (3) coexisting chronic medical conditions (asthma); and (4) lifestyle factors (sleep inadequacy, excessive internet use and pathological gaming).
CONCLUSION
The identified factors were largely similar to those reported in the global literature, except for sleep inadequacy along with conspicuously absent factors such as academic stress and strict parenting, which should prompt further research in these areas. Further research should focus on current and prospective interventions to improve mental health literacy, targeting sleep duration, internet use and gaming, and mitigating the risk of depression in patients with chronic disease in the primary care and community setting.
Humans
;
Singapore/epidemiology*
;
Adolescent
;
Risk Factors
;
Depression/etiology*
;
Protective Factors
;
Male
;
Female
;
Life Style
;
Suicide
8.Singapore consensus statements on the management of obstructive sleep apnoea.
Leong Chai LEOW ; Chuen Peng LEE ; Sridhar VENKATESWARAN ; Michael Teik Chung LIM ; Oon Hoe TEOH ; Ruth CHANG ; Yam Cheng CHEE ; Khai Beng CHONG ; Ai Ping CHUA ; Joshua GOOLEY ; Hong Juan HAN ; Nur Izzianie KAMARUDDIN ; See Meng KHOO ; Lynn Huiting KOH ; Shaun Ray Han LOH ; Kok Weng LYE ; Mark IGNATIUS ; Yingjuan MOK ; Jing Hao NG ; Thun How ONG ; Chu Qin PHUA ; Rui Ya SOH ; Pei Rong SONG ; Adeline TAN ; Alvin TAN ; Terry TAN ; Jenny TANG ; David TAY ; Jade TAY ; Song Tar TOH ; Serene WONG ; Chiang Yin WONG ; Mimi YOW
Annals of the Academy of Medicine, Singapore 2025;54(10):627-643
INTRODUCTION:
Obstructive sleep apnoea (OSA) is common in Singapore, with moderate to severe OSA affecting around 30% of residents. These consensus statements aim to provide scientifically grounded recommendations for the management of OSA, standar-dise the management of OSA in Singapore and promote multidisciplinary collaboration.
METHOD:
An expert panel, which was convened in 2024, identified several areas of OSA management that require guidance. The expert panel reviewed the current literature and developed consensus statements, which were later independently voted on using a 3-point Likert scale (agree, neutral or disagree). Consensus (total ratings of agree and neutral) was set a priori at ≥80% agreement. Any statement not reaching consensus was excluded.
RESULTS:
The final consensus included 49 statements that provide guidance on the screening, diagnosis and management of adults with OSA. Additionally, 23 statements on the screening, diagnosis and management of paediatric OSA achieved consensus. These 72 consensus statements considered not only the latest clinical evidence but also the benefits and harms, resource implications, feasibility, acceptability and equity impact of the recommendations.
CONCLUSION
The statements presented in this paper aim to guide clinicians based on the most updated evidence and collective expert opinion from sleep specialists in Singapore. These recommendations should augment clinical judgement rather than replace it. Management decisions should be individualised, taking into account the patient's clinical characteristics, as well as patient and caregiver concerns and preferences.
Humans
;
Sleep Apnea, Obstructive/diagnosis*
;
Singapore
;
Consensus
;
Adult
9.Mechanism of mitochondrial oxidative phosphorylation disorder in male infertility.
Kai MENG ; Qian LIU ; Yiding QIN ; Wenjie QIN ; Ziming ZHU ; Longlong SUN ; Mingchao JIANG ; Joseph ADU-AMANKWAAH ; Fei GAO ; Rubin TAN ; Jinxiang YUAN
Chinese Medical Journal 2025;138(4):379-388
Male infertility has become a global concern, accounting for 20-70% of infertility. Dysfunctional spermatogenesis is the most common cause of male infertility; thus, treating abnormal spermatogenesis may improve male infertility and has attracted the attention of the medical community. Mitochondria are essential organelles that maintain cell homeostasis and normal physiological functions in various ways, such as mitochondrial oxidative phosphorylation (OXPHOS). Mitochondrial OXPHOS transmits electrons through the respiratory chain, synthesizes adenosine triphosphate (ATP), and produces reactive oxygen species (ROS). These mechanisms are vital for spermatogenesis, especially to maintain the normal function of testicular Sertoli cells and germ cells. The disruption of mitochondrial OXPHOS caused by external factors can result in inadequate cellular energy supply, oxidative stress, apoptosis, or ferroptosis, all inhibiting spermatogenesis and damaging the male reproductive system, leading to male infertility. This article summarizes the latest pathological mechanism of mitochondrial OXPHOS disorder in testicular Sertoli cells and germ cells, which disrupts spermatogenesis and results in male infertility. In addition, we also briefly outline the current treatment of spermatogenic malfunction caused by mitochondrial OXPHOS disorders. However, relevant treatments have not been fully elucidated. Therefore, targeting mitochondrial OXPHOS disorders in Sertoli cells and germ cells is a research direction worthy of attention. We believe this review will provide new and more accurate ideas for treating male infertility.
Male
;
Humans
;
Infertility, Male/metabolism*
;
Oxidative Phosphorylation
;
Mitochondria/metabolism*
;
Spermatogenesis/physiology*
;
Sertoli Cells/metabolism*
;
Oxidative Stress/physiology*
;
Animals
;
Reactive Oxygen Species/metabolism*
10.Function of flavoprotein monooxygenases in natural product biosynthesis.
Meng-Ya CHENG ; Chang LIU ; He-Xin TAN
China Journal of Chinese Materia Medica 2025;50(1):71-77
Flavoprotein monooxygenases(FPMOs) and cytochrome P450(CYP450) oxygenases are pivotal monooxygenases in nature, catalyzing crucial redox reactions in diverse biological processes and contributing to the synthesis of highly complex natural products. While CYP450 enzymes have been extensively reported and studied, numerous FPMOs have also been discovered in past research endeavors, yet their classification, catalytic reactions, and catalytic mechanisms remain to be systematically analyzed. This paper comprehensively reviews the latest advancements in FPMOs research, initiating with a classification based on sequence similarities and distinct structural features. It delves into the catalytic characteristics of three subfamilies(FMO, BVMO, and NMO) within Class B FPMOs of plants, which are integral to biosynthetic pathways of natural products. Class B FPMOs encompass two canonical Rossmann fold motifs(FAD-binding GxGxxG and NADPH-binding GxGxxA), along with a central FMO recognition motif FxGxxxHxxxF/Y/W. These enzymes play a key role in regulating various metabolic routes and precisely modulate plant growth and development. Furthermore, the review summarizes the applications of Class B FPMOs of plants, showcasing through concrete examples their potential in synthesizing natural products such as auxins, indigo, and cyanogenic glycosides. These insights will broaden and deepen our understanding of FPMOs, fostering their transition from fundamental research to practical applications. More optimized biosynthetic pathways can be devised by leveraging FPMOs, conducive to the development of novel strategies and tools for agriculture, plant protection, natural product biosynthesis, and synthetic biology.
Biological Products/metabolism*
;
Mixed Function Oxygenases/chemistry*
;
Flavoproteins/chemistry*
;
Plants/metabolism*
;
Plant Proteins/chemistry*
;
Cytochrome P-450 Enzyme System/genetics*

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