1.The Mechanism of Blue Light in Inactivating Microorganisms and Its Applications in The Food and Medical Fields
Ruo-Hong BI ; Rong-Qian WU ; Yi LÜ ; Xiao-Fei LIU
Progress in Biochemistry and Biophysics 2025;52(5):1219-1228
Blue light inactivation technology, particularly at the 405 nm wavelength, has demonstrated distinct and multifaceted mechanisms of action against both Gram-positive and Gram-negative bacteria, offering a promising alternative to conventional antibiotic therapies. For Gram-positive pathogens such as Bacillus cereus, Listeria monocytogenes, and methicillin-resistant Staphylococcus aureus (MRSA), the bactericidal effects are primarily mediated by endogenous porphyrins (e.g., protoporphyrin III, coproporphyrin III, and uroporphyrin III), which exhibit strong absorption peaks between 400-430 nm. Upon irradiation, these porphyrins are photoexcited to generate cytotoxic reactive oxygen species (ROS), including singlet oxygen, hydroxyl radicals, and superoxide anions, which collectively induce oxidative damage to cellular components. Early studies by Endarko et al. revealed that (405±5) nm blue light at 185 J/cm² effectively inactivated L. monocytogenes without exogenous photosensitizers, supporting the hypothesis of intrinsic photosensitizer involvement. Subsequent work by Masson-Meyers et al. demonstrated that 405 nm light at 121 J/cm² suppressed MRSA growth by activating endogenous porphyrins, leading to ROS accumulation. Kim et al. further elucidated that ROS generated under 405 nm irradiation directly interact with unsaturated fatty acids in bacterial membranes, initiating lipid peroxidation. This process disrupts membrane fluidity, compromises structural integrity, and impairs membrane-bound proteins, ultimately causing cell death. In contrast, Gram-negative bacteria such as Salmonella, Escherichia coli, Helicobacter pylori, Pseudomonas aeruginosa, and Acinetobacter baumannii exhibit more complex inactivation pathways. While endogenous porphyrins remain central to ROS generation, studies reveal additional photodynamic contributors, including flavins (e.g., riboflavin) and bacterial pigments. For instance, H. pylori naturally accumulates protoporphyrin and coproporphyrin mixtures, enabling efficient 405 nm light-mediated inactivation without antibiotic resistance concerns. Kim et al. demonstrated that 405 nm light at 288 J/cm² inactivates Salmonella by inducing genomic DNA oxidation (e.g., 8-hydroxy-deoxyguanosine formation) and disrupting membrane functions, particularly efflux pumps and glucose uptake systems. Huang et al. highlighted the enhanced efficacy of pulsed 405 nm light over continuous irradiation for E. coli, attributing this to increased membrane damage and optimized ROS generation through frequency-dependent photodynamic effects. Environmental factors such as temperature, pH, and osmotic stress further modulate susceptibility, sublethal stress conditions (e.g., high salinity or acidic environments) weaken bacterial membranes, rendering cells more vulnerable to subsequent ROS-mediated damage. The 405 nm blue light inactivates drug-resistant Pseudomonas aeruginosa through endogenous porphyrins, pyocyanin, and pyoverdine, with the inactivation efficacy influenced by bacterial growth phase and culture medium composition. Intriguingly, repeated 405 nm exposure (20 cycles) failed to induce resistance in A. baumannii, with transient tolerance linked to transient overexpression of antioxidant enzymes (e.g., superoxide dismutase) or stress-response genes (e.g., oxyR). For Gram-positive bacteria, porphyrin abundance dictates sensitivity, whereas in Gram-negative species, membrane architecture and accessory pigments modulate outcomes. Critically, ROS-mediated damage is nonspecific, targeting DNA, proteins, and lipids simultaneously, thereby minimizing resistance evolution. The 405 nm blue light technology, as a non-chemical sterilization method, shows promise in medical and food industries. It enhances infection control through photodynamic therapy and disinfection, synergizing with red light for anti-inflammatory treatments (e.g., acne). In food processing, it effectively inactivates pathogens (e.g., E. coli, S. aureus) without altering food quality. Despite efficacy against multidrug-resistant A. baumannii, challenges include device standardization, limited penetration in complex materials, and optimization of photosensitizers/light parameters. Interdisciplinary research is needed to address these limitations and scale applications in healthcare, food safety, and environmental decontamination.
2.Research progress on the influencing factors of psychological distress in patients with coronary heart disease
Xiaotian DUAN ; Hongshi CAO ; Taiyu BI ; Haiyan WANG ; Songyu WANG ; Quantong ZHAO ; Ran WANG ; Chunjing WU
Sichuan Mental Health 2025;38(1):89-96
Coronary heart disease is a chronic and lifelong disease, which places a dual burden on the physiological and psychological well-being of patients, and can easily lead to psychological distress and affect their prognosis and quality of life. This article provides a systematic review, in which the current status, evaluation tools, influencing factors and intervention methods of psychological distress in patients with coronary heart disease are explored, aiming to provide key information beneficial for identifying and preventing psychological distress, and to improve the overall management and treatment effectiveness of coronary heart disease patients. In this paper, 18 articles were included, and the demographic, physiological, psychological and social factors affecting the psychological distress of patients with coronary heart disease were systematically analyzed, thus to provide a deeper understanding of psychological distress and offering references for formulating targeted intervention strategies.
3.Role of ferroptosis in fibrosis: From mechanism to potential therapy
Xuemeng QIU ; Qing BI ; Jiyue WU ; Zejia SUN ; Wei WANG
Chinese Medical Journal 2024;137(7):806-817
Fibrosis, which is a manifestation of the physiological response to injury characterized by excessive accumulation of extracellular matrix components, is a ubiquitous outcome of the repair process. However, in cases of repetitive or severe injury, fibrosis may become dysregulated, leading to a pathological state and organ failure. In recent years, a novel form of regulated cell death, referred to as ferroptosis, has been identified as a possible contributor to fibrosis; it is characterized by iron-mediated lipid peroxidation. It has garnered attention due to the growing body of evidence linking ferroptosis and fibrogenesis, which is believed to be driven by underlying inflammation and immune responses. Despite the increasing interest in the relationship between ferroptosis and fibrosis, a comprehensive understanding of the precise role that ferroptosis plays in the formation of fibrotic tissue remains limited. This review seeks to synthesize previous research related to the topic. We categorized the different direct and indirect mechanisms by which ferroptosis may contribute to fibrosis into three categories: (1) iron overload toxicity; (2) ferroptosis-evoked necroinflammation, with a focus on ferroptosis and macrophage interplay; and (3) ferroptosis-associated pro-fibrotic factors and pathways. Furthermore, the review considers the potential implications of these findings and highlights the utilization of ferroptosis-targeted therapies as a promising strategy for mitigating the progression of fibrosis. In conclusion, novel anti-fibrotic treatments targeting ferroptosis could be an effective treatment for fibrosis.
4.mfat-1 gene therapy prevents and ameliorates multiple sclerosis in mice
Min-Yi TANG ; Xin-Yun BI ; Shuai WANG ; Chao-Feng XING ; Xiao-Li WU ; Zi-Jian ZHAO ; Fang-Hong LI
Chinese Pharmacological Bulletin 2024;40(10):1930-1936
Aim To investigate the preventive and therapeutic effects of the mfat-1 gene therapy on exper-imental autoimmune encephalomyelitis in mice.Meth-ods mfat-1 gene therapy was used to render the host endogenous capability of producing ω-3 PUFAs,con-comitantly reduce the levels of ω-6 PUFAs,and change the proportion of ω-3/ω-6 PUFAs.Then,the levels of PUFAs in blood were analyzed by gas chromatography.The neurological deficits in mice were evaluated by neurological dysfunction score.HE staining and LFB staining of mouse spinal cord slices were used to ob-serve central nervous system inflammation infiltration and demyelinating lesions.Flow cytometry microsphere microarray technology was used to detect the content of cytokines in serum.Results The mfat-1 gene therapy could significantly raise the proportion of ω-3/ω-6 PU-FAs(P<0.05),markedly delay the incubation period and peak period and reduce neurological dysfunction scores(P<0.05),and improve inflammation and de-myelination of spinal cords(P<0.05).It could also greatly increase the levels of IL-2,IFN-γ,IL-4 and IL-17 in serum(P<0.05).Conclusion The pro-portion of ω-3/ω-6 PUFAs in blood circulation en-hanced by mfat-1 gene therapy can effectively prevent and treat experimental autoimmune encephalomyelitis in mice.
5.Antimicrobial resistance and resistance gene carriage by Salmonella bacteria in environmental sewage in Guangzhou
Bi-Hui SU ; Guang-Hong DU ; Xiao-Ying WU ; Gang HE ; Jun YUAN ; Chao-Jun XIE
Chinese Journal of Zoonoses 2024;40(5):442-447
This study explored the antibiotic resistance and resistance gene carriage of 140 Salmonella strains isolated from environmental sewage in Guangzhou city between March 1,2022,and November 30,2022.The micro broth dilution method was used to select 17 antibiotics for susceptibility testing.According to whole genome sequencing results,the CARD resistance database was used to obtain corresponding resistance genes.High antimicrobial resistance rates above 80%were observed a-gainst ampicillin,tetracycline,streptomycin,chloramphenicol,and cotrimoxazole.The intermediation rate of polymyxin E and ciprofloxacin exceeded 60%.The multiple drug resistance status was severe,and the rate of multiple drug resistance was as high as 92.86%.The strains carried multiple types of resistance genes,particularly for aminoglycosides,with a carriage rate as high as 92.68%.The resistance of Salmonella in environmental wastewater in Guangzhou to one or more drugs was severe,and the overall multi-drug resistance rate gradually increased over time.The resistance spectrum was diverse,and the resistance mechanism,mediated by mobile genetic elements such as re-sistance genes,was found to be the main cause of resistance to one or more drugs.
6.Urogenital Chlamydia trachomatis infection and genotyping in an outpatient clinic in Hainan
WU Jie ; LIN Lihua ; WANG Bi ; WANG Huangyu ; ZHONG Na
China Tropical Medicine 2024;24(3):315-
Objective To conduct preliminary research on the prevalence and genotyping of urogenital Chlamydia trachomatis (CT) infection in sexually transmitted disease (STD) clinics in Hainan Province, to understand the epidemiological characteristics and genotype features of the population infected with urogenital CT, and to provide evidence for the formulation of scientific prevention strategies and measures. Methods From 2018 to 2022, a total of 5 551 male urethral swabs and female cervical swabs were collected for detection of CT infection by real-time fluorescent quantitative polymerase chain reaction (RT-PCR). The OMPL gene was amplified from the DNA of some CT positive individuals by nested PCR, and the positive results were sequenced. Sequencing results were uploaded to BLAST website to find sequence similarity and construct a phylogenetic tree to determine the genotype. Results Out of the 5 551 tested patients, 846 were positive for Chlamydia trachomatis infection, with a positivity rate of 15.2%, the positive detection rate of CT-DNA was 18.6% in male and 13.4% in female, the positive detection rate of male was higher than that of female. There were statistically significant differences in the CT-DNA positivite detection rate among different age groups (P<0.05), and the highest positivite rate CT-DNA was 58.0% in 20-<30 years old, while it was the lowest, at 1.0%, in those over 50; there were also significant differences in CT-DNA positivity detection rate between seasons (P<0.05), with the highest being 36.4% in the summer and the lowest at 9.6% in the winter. Genotyping of the CT-OMPL gene VS1-VS2 nucleotide sequence in some samples from the Hainan region identified six genotypes, including types D, E, G, F, J, and K, with type F being the main prevalent dominant type. Conclusions CT infection in Hainan is associated with gender, age, and season, and the genotypes are diversified. It is necessary to further strengthen the screening of CT infection in the reproductive tract of men and women of childbearing age in the future STD prevention and treatment work to improve the fertility rate.
7.Chemical constituents from the leaves of Citrus reticulata and their anti-inflammatory activities
Fa-Ke YANG ; Xing YANG ; Zhi-Bi ZHANG ; Rui YIN ; Hong-Chuan ZHANG ; Xu-Li DENG ; Wei-Mao DONG ; Yi-Mou WANG ; Hong-Ping HE ; Fa-Wu DONG
Chinese Traditional Patent Medicine 2024;46(9):2972-2979
AIM To study the chemical constituents from the leaves of Citrus reticulata Blanco and their anti-inflammatory activities.METHODS The 85%ethanol extract from the leaves of C.reticulata was isolated and purified by silica gel,D101 macroporous resin,MCI,ODS and Sephadex LH-20,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The Griess method was used to determine their inhibitory activities on lipopolysaccharide-induced NO production in macrophages RAW 264.7 cells.The mice foot swelling inflammation model induced by carrageenan was established,and the levels of IL-1β,TNF-α were detected.RESULTS Twelve compounds were isolated and identified as nobiletin(1),tangeretin(2),5-demethylinoblitin(3),5,4'-dihydroxy-6,7,8,3'-tetramethoxy flavone(4),5-hydroxy-7,8,3',4'-trimethoxyflavanone(5),3,5,6,7,8,3',4'-heptamethoxyflavanone(6),hesperetin(7),5-hydroxy-6,7,3',4'-tetramethoxyphenone(8),β-balsam alcohol(9),stigmaster-5-en-3β-alcohol(10),p-hydroxybenzaldehyde(11),vanillin(12).Compounds 1,4,6,7,10 and 12 had strong inhibitory activites on NO release in LPS-induced RAW 264.7 cells,and the IC50 values were(25.21±2.10),(37.77±0.50),(38.19±1.58),(21.89±1.73),(43.81±1.18),(47.98±2.55),(41.23±1.11),(43.80±1.43)μmol/mL,respectively.Compounds 2-3 reduced IL-1β and TNF-α levels(P<0.05,P<0.01).CONCLUSION Compounds 6-7,9 are isolated from this plant for the first time.Compounds 1-4,8 exhibit strong in vitro anti-inflammatory activities,and compounds 2-3 exhibit significant in vivo anti-inflammatory activities.
8.Constructing a diagnostic prediction model for antibody-mediated rejection after kidney transplantation based upon bioinformatics and machine learning algorithms
Jiyue WU ; Zejia SUN ; Qing BI ; Xuemeng QIU ; Wei WANG
Chinese Journal of Organ Transplantation 2024;45(10):718-727
Objective:To construct a diagnostic prediction nomogram for antibody-mediated rejection (AMR) after kidney transplantation (KT) based upon peripheral blood gene expression profiling and preliminarily screening potential drugs for AMR.Methods:Seven large kidney transplant cohort datasets related to AMR were retrieved from the database of GEO. Differential expression analysis was utilized for identifying differentially expressed genes between AMR and normal recipients. Multiple machine learning algorithms of random forest (RF), extreme gradient boosting (XGB), support vector machine (SVM) and generalized linear model (GLM) were employed for constructing diagnostic models for AMR after kidney transplantation. Receiver operating characteristic (ROC) curve was plotted for comparing the accuracy of each model. The key genes of optimal model were integrated for creating a diagnostic prediction nomogram for AMR. Calibration curve and decision curve analyses were employed for evaluating the accuracy of nomogram. The differentially expressed genes from biopsy tissues of AMR recipients were uploaded to the database of CMap for identifying potential therapeutic drugs through screening Top 5 compounds with opposite expression patterns to AMR.Results:Seven genes of CXCL10, FCGR1B, GBP5, CD69, LY96, BCL2A1 and EVI2A were over-expressed in both peripheral blood and biopsy tissues of AMR recipients. There were statistically significant differences with recipients without AMR (FDR<0.05). The AMR diagnostic model based upon RF algorithm demonstrated the highest AUC value (0.904) among various machine learning algorithms. Its AUC values were 0.876 and 0.824 in external datasets of GSE50084 and GSE175718. As for the diagnostic prediction nomogram constructed through integrating five key genes of BCL2A1, CXCL10, FCGR1BP, CD69 & EVI2A from RF model, calibration curve indicated that the predicted outcomes of nomogram approximated actual outcomes. Decision curve indicated that net benefit rate of nomogram was higher than that of extreme curves over a wide range of horizontal axis. The predicted results of CMap suggested that Top 5 compounds were raltegravir, rilmenidine, hydrastine, metyrapone and valproic acid.Conclusions:The nomogram constructed based upon peripheral blood gene expression profiling demonstrates high accuracy and generalizability in the diagnosis of AMR. As predicted by CMap, raltegravir, rilmenidine, hydrastine, metyrapone and valproic acid may be potential therapeutic drugs for AMR.
9.The effects of plasma spraying tantalum-coated titanium on osseointegration in rats
Xiaoyan WU ; Miao YU ; Xiao GE ; Xiuting BI ; Chen YU ; Ti LI
Journal of Practical Stomatology 2024;40(4):473-479
Objective:To study the osseointegration and new bone formation of titanium implants treated by sandblasting acid etching combined with plasma spraying tantalum coating in rats.Methods:After polishing and cleaning of the pure titanium specimens(SLA),the tantalum coating was prepared by plasma spraying after sandblasting and acid etching(SLA-Ta).The surface feature of the samples was observed by SEM,EDS and contact angle meter.The samples of SLA and SLA-Ta were respectively implanted into femur condyle at each side of 18 SD rats(SLA group and SLA-Ta group),and the rats were double-fluorescent labeled after surgery.The rats were sacrificed 4 and 12 weeks after implantation respectively(n=9),the samples of implants and surrounding tissue were examined by mi-cro-CT scanning,fluorescence microscopy and histological staining,the new bone formation and osseointegration around the implant were analyzed.Results:Micro-nano Porous structureed tantalum coating was successfully prepared on the surface of SLA titanium.In vivo experiments showed that 4 and 12 weeks after implantation,the amount of new bone and osseointegration around the implant in the SLA-Ta group were significantly higher than those in the SLA group.Conclusion:The micro-nano multi-level structure formed by SLA combined with plasma sprayed tantalum can promote new bone formation,accelerate mineralization deposition,and improve the osseoin-tegration capacity of the implant.
10.A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020
Cai-Yun WANG ; Hong-Mei XU ; Gang LIU ; Jing LIU ; Hui YU ; Bi-Quan CHEN ; Guo ZHENG ; Min SHU ; Li-Jun DU ; Zhi-Wei XU ; Li-Su HUANG ; Hai-Bo LI ; Dong WANG ; Song-Ting BAI ; Qing-Wen SHAN ; Chun-Hui ZHU ; Jian-Mei TIAN ; Jian-Hua HAO ; Ai-Wei LIN ; Dao-Jiong LIN ; Jin-Zhun WU ; Xin-Hua ZHANG ; Qing CAO ; Zhong-Bin TAO ; Yuan CHEN ; Guo-Long ZHU ; Ping XUE ; Zheng-Zhen TANG ; Xue-Wen SU ; Zheng-Hai QU ; Shi-Yong ZHAO ; Lin PANG ; Hui-Ling DENG ; Sai-Nan SHU ; Ying-Hu CHEN
Chinese Journal of Contemporary Pediatrics 2024;26(2):131-138
Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

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