Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Aim To investigate the effects of berberine(BBR)combined with 5'-n-ethylformamidoadenosine(NECA)on myocardial H9c2 and HL-1 cell damage induced by hypoxia/reoxygenation(H/R).Methods H9c2 and HL-1 cells were divided into the Control group,BBR group,NECA group,combined administra-tion group,H/R group,BBR+H/R group,NECA+H/R group,and combined administration+H/R group.CCK-8 was used to detect cell viability in each group.The TMRE kit was used to detect MMP.DCFH-DA was used to detect ROS content.The Mito SOX Red fluorescent probe was used to detect mitochondrial su-peroxide.The expressions of COX Ⅳ,Tom20,and Tim23 were detected by Western blot.The expression of COX Ⅳ and Tom20 genes was detected by qRT-PCR.Results In H9c2 cells,the cell viability and TMRE fluorescence intensity in the H/R group were significantly decreased compared with the Control group.The protein expressions of COX Ⅳ,Tom20,and Tim23,gene expressions of COX Ⅳ and Tom20,ROS,and mitochondrial superoxide contents were significant-ly increased.Compared with the H/R group,the cell viability of BBR and NECA were enhanced after ad-ministration alone.The contents of ROS and mitochon-drial superoxide were significantly decreased.In HL-1 cells,cell viability in the H/R group was significantly decreased compared with the Control group.The con-tents of ROS and mitochondrial superoxide were signifi-cantly increased.Compared with the H/R group,BBR and NECA alone and combined administration en-hanced cell viability.The contents of ROS and mito-chondrial superoxide were significantly decreased.Conclusion The administration of BBR and NECA a-lone or in combination can reduce the production of mi-tochondrial superoxide and cell ROS,thereby allevia-ting mitochondrial damage,alleviating oxidative stress damage,and ultimately reducing H/R-induced myocar-dial cell damage.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Chlamydia psittaci is a worldwide distributed zoonotic pathogen that infects a variety of birds.In order to char-acterization of the duck originated C.psittaci strains,lung samples were collected from suspected infection ducks and was de-tected by real-time PCR.The positive samples were homogenized in phosphate buffered saline with kanamycin and streptomy-cin,and then inoculated onto L929 cells monolayer.After several sets of passages,chlamydial inclusions of the isolate in cul-tured cells were observed after Giemsa staining or by electron microscope.For species identification,16S rRNA,16-23S IGS gene fragments were sequenced and analyzed.Genotyping of the isolate was performed by comparative analysis of the obtained ompA gene sequence with that of different genotype of C.psittaci strains.A C.psittaci strain was successfully isolated from the lung sample of duck by cell culture and was identified as genotype A.This study expanded our understanding of the host range of genotype A C.psittaci strain,and provided basis for further research on the pathogenicity,transmission,and public health risk of this pathogen.

Objective:To investigate the effect of genetic polymorphism of MTHFR C677T (rs1801133) on methotrexate (MTX) related toxicity in pediatric mature B-cell lymphoma patients. Methods:Fifty-eight intermediate and high risk patients under 18 years of age with mature B-cell lymphoma who received 5 g/m2 MTX (24 h intravenous infusion) in Sun Yat-sen University Cancer Center from August 2014 to December 2021 were included,and their toxicity of high-dose MTX (HD-MTX) were monitored and analyzed. Results:Among the 58 pediatric patients,the number of CC,CT,and TT genotypes for MTHFR C677T was 33,19 and 6,respectively. A total of 101 courses of HD-MTX therapy were counted,of which plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion were observed in 35 courses,≤0.2 μmol/L in 66 courses. Inter-group comparison showed that plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion increased the risk of developing oral mucositis (P<0.05). Compared with wild-type (CC genotype),patients in the mutant group (CT+TT genotype) were more likely to develop myelosuppression,manifested as anemia,leucopenia,neutropenia and thrombocytopenia. However,plasma MTX level at 48 h was not associated with MTHFR C677T gene polymorphism. Conclusion:The risk of developing oral mucositis in children with mature B-cell lymphoma is associated with plasma MTX concentration. Polymorphism of MTHFR C677T gene is not related to plasma MTX concentration in children with mature B-cell lymphoma,but is related to grade Ⅲ to Ⅳ hematological toxicity.

Objective:To investigate the clinical and genetic characteristics of a male carrier of exceptional complex chromo-some rearrangement(CCR)and the outcome of preimplantation genetic testing for chromosomal structural rearrangement(PGT-SR).Methods:Using the modified high resolution G banding technique and whole-genome low-coverage sequencing(WGLCS),we analyzed the cellular karyotype and molecular karyotype of a male carrier of CCR,performed an analysis of the single-sperm chromosome copy number and conducted PGT-SR for the patient by next-generation sequencing(NGS).In addition,we reviewed the literature on repor-ted male carriers of CCRs and summarized their normal/balanced sperm ratios and PGT-SR outcomes.Results:The karyotype of the patient was 46,XY,der(5)inv(5)(q14.3q23.2)t(5;14;11)(q23.2;q31.1;q21),der(11)t(5;14;11);der(14)t(5;14;11),with the translocation breakpoints located in the intergenic region.Single-sperm sequencing revealed 20.0%(7/35)of normal haploids in the male's spermatozoa,and the results PGT-SR showed a proportion of 25.0%(4/16)of normal/balanced embryos.After thawing and transferring of 2 euploid blastocysts,a healthy male infant was successfully delivered.Conclusion:The proportion of normal hap-loids in the spermatozoa of male CCR carriers may be higher than theoretically predicted,and PGT-SR can effectively improve the preg-nancy outcome in male CCR carriers and provide valuable data for genetic counseling.

AIM To study the chemical constituents of dichloromethane fraction from Hypericum perforatum L.METHODS The dichloromethane fraction from H.perforatum was isolated and purified by silica gel,ODS,Sephadex LH-20,semi-preparative HPLC and etc.The structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Eleven compounds were isolated and identified as hypernorpoleketone A(1),α-onocerin(2),(3R)-thunberginol C(3),2-geranyloxy-1-(2-methylpropanoyl)-phloroglucinol(4),4,6-dihydroxy-2-O-(3″,7″-dimethyl-2″,6″-octadienyl)-1-(2′-methylbutanoyl)benzene(5),norhyperpalum G(6),garsubellin A(7),garsubellin B(8),(2″R/S)-kellerine C(9),kobusone(10),eriodictyol(11).CONCLUSION Compound 1 is a new compound.Compounds 2-3 are isolated from the plants of family Guttiferae for the first time.Compounds 4-10 are isolated from this plant for the first time.

Objective:To compare the efficacy between vonoprazan fumarate and rabeprazole for the treatment of artificial ulcers after endoscopic submucosal dissection (ESD).Methods:In this prospective randomized controlled study, patients who underwent ESD between December 2021 and August 2023 at Jiangsu Province Hospital were enrolled and randomly divided into two groups. Vonoprazan fumarate combined with rebamipide (vonoprazan group) or rabeprazole combined with rebamipide (rabeprazole group) were given respectively from the 4th day after ESD. After 8 weeks, the healing of the ulcers was compared.Results:Ninety-one patients were enrolled in the study, including 51 in the vonoprazan group and 40 in the rabeprazole group. The ulcer area reduction rate of the vonoprazan group was significantly higher than that of the rabeprazole group (92.86%±3.80% VS 90.04%±4.28%, t=3.281, P=0.001), but there was no significant difference in the healing rate [15.69% (8/51) VS 7.50% (3/40), χ2=1.414, P=0.234] or the adverse event occurrence ( P>0.05) between the two groups. Conclusion:Vonoprazan fumarate can achieve better ulcer treatment without increasing the risk of adverse events.

Objective To explore the relevant risk factors of H.pylori infection,and provide reference for prevention and treatment of H.pylori in this area,and further provide theoretical basis for the prevention and treatment of gastric cancer.Methods A total of 1200 residents in four districts of Haikou city were investigated by questionnaire and urea 14 C breath test by holistic stratified random sampling to calculate the population infection rate and analyze the risk factors of infection.Results The total infection rate was 32.5％,which was lower than the national H.pylori infection rate.No consumption of fruits and vegetables,no habit of washing hands before meals,and people with gastrointestinal symptoms,are independent risk factors of H.pylori infection.No consumption of pickled products is of great significance to prevent H.pylori infection.Conclusion The prevalence of H.pylori infection in the population of Haikou is lower than the national average,and H.pylori infection is closely related to the poor living habits of residents.

Objective:To evaluate the efficacy and safety of hypomethylating agents (HMA) in patients with myelodysplastic syndromes (MDS) .Methods:A total of 409 MDS patients from 45 hospitals in Zhejiang province who received at least four consecutive cycles of HMA monotherapy as initial therapy were enrolled to evaluate the efficacy and safety of HMA. Mann-Whitney U or Chi-square tests were used to compare the differences in the clinical data. Logistic regression and Cox regression were used to analyze the factors affecting efficacy and survival. Kaplan-Meier was used for survival analysis. Results:Patients received HMA treatment for a median of 6 cycles (range, 4-25 cycles) . The complete remission (CR) rate was 33.98% and the overall response rate (ORR) was 77.02%. Multivariate analysis revealed that complex karyotype ( P=0.02, OR=0.39, 95% CI 0.18-0.84) was an independent favorable factor for CR rate. TP53 mutation ( P=0.02, OR=0.22, 95% CI 0.06-0.77) was a predictive factor for a higher ORR. The median OS for the HMA-treated patients was 25.67 (95% CI 21.14-30.19) months. HMA response ( P=0.036, HR=0.47, 95% CI 0.23-0.95) was an independent favorable prognostic factor, whereas complex karyotype ( P=0.024, HR=2.14, 95% CI 1.10-4.15) , leukemia transformation ( P<0.001, HR=2.839, 95% CI 1.64-4.92) , and TP53 mutation ( P=0.012, HR=2.19, 95% CI 1.19-4.07) were independent adverse prognostic factors. There was no significant difference in efficacy and survival between the reduced and standard doses of HMA. The CR rate and ORR of MDS patients treated with decitabine and azacitidine were not significantly different. The median OS of patients treated with decitabine was longer compared with that of patients treated with azacitidine (29.53 months vs 20.17 months, P=0.007) . The incidence of bone marrow suppression and pneumonia in the decitabine group was higher compared with that in the azacitidine group. Conclusion:Continuous and regular use of appropriate doses of hypomethylating agents may benefit MDS patients to the greatest extent if it is tolerated.