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.

Breast cancer， as one of the major cancers threatening women's health globally， is characterized by high aggressiveness， high malignancy， and poor prognosis. In 2022， according to the World Health Organization， breast cancer ranked second in the incidence of female cancers globally， accounting for 11.6% of all new cancer cases. Western medical doctors mainly use surgery， chemotherapy， radiotherapy， endocrine therapy， and molecular targeted therapy to treat breast cancer， which can effectively improve the recurrence rate and death rate of breast cancer patients and prolong the survival period of patients. However， its treatment process is often accompanied by a series of side effects， which bring challenges to patients' quality of life. However， traditional Chinese medicine （TCM） has demonstrated significant therapeutic effects in inhibiting the proliferation and metastasis of breast cancer cells， reducing toxic side effects produced by chemotherapy， and improving patients' survival rate and quality of life. It is therefore particularly necessary to investigate the pharmacological effects and mechanisms of TCM in breast cancer treatment. The authors combed the pharmacological effects and mechanisms of the etiology and pathogenesis of breast cancer， identification and treatment of breast cancer， TCM compound， TCM single medicine， TCM monomer， and external treatment of TCM to prevent and control breast cancer and found that TCM has a therapeutic effect on breast cancer. It can play a role in increasing the effectiveness， reducing the toxicity， and alleviating the adverse reactions. It can inhibit breast cancer cell proliferation， cell cycle， migration， invasion， immune escape， epithelial-mesenchymal transition （EMT）， aerobic glycolysis， mitochondrial biosynthesis， aminoacyl-tRNA biosynthesis， reduce drug resistance， promote apoptosis， ferroptosis， cell autophagy， and regulate the tumor immune microenvironment by regulating signaling pathways. This paper aims to provide new ideas and methods for experimental research and clinical treatment of breast cancer.

Epigenetic pathways play a critical role in the initiation, progression, and metastasis of cancer. Over the past few decades, significant progress has been made in the development of targeted epigenetic modulators (e.g., inhibitors). However, epigenetic inhibitors have faced multiple challenges, including limited clinical efficacy, toxicities, lack of subtype selectivity, and drug resistance. As a result, the design of new epigenetic modulators (e.g., degraders) such as PROTACs, molecular glue, and hydrophobic tagging (HyT) degraders has garnered significant attention from both academia and pharmaceutical industry, and numerous epigenetic degraders have been discovered in the past decade. In this review, we aim to provide an in-depth illustration of new degrading strategies (2017-2023) targeting epigenetic proteins for cancer therapy, focusing on the rational design, pharmacodynamics, pharmacokinetics, clinical status, and crystal structure information of these degraders. Importantly, we also provide deep insights into the potential challenges and corresponding remedies of this approach to drug design and development. Overall, we hope this review will offer a better mechanistic understanding and serve as a useful guide for the development of emerging epigenetic-targeting degraders.

Three 2,3-diketoquinoxaline alkaloids were isolated from Heterosmilax yunnanensis Gagnep. Their structures were determined through 1D and 2D NMR, HR-ESI-MS, UV, and IR as 1-[5′-(3″-hydroxy-3″-methyl) glutaryl] ribityl-2,3-diketo-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline (1), 1-[2′-(3″-hydroxy-3″-methyl) glutaryl]ribityl-2,3-diketo-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline (2), and 1-ribityl-2,3-diketo-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline (3). Compounds 1 and 2 are novel compounds, and 3 was isolated from H. yunnanensis for the first time. The hepatoprotective activity of these three compounds was evaluated, with compound 3 showing promising hepatoprotective activity.

Objective To observe the efficacy and safety of flumatinib conversion in chronic myelogenous leukemia-chronicphase(CML-CP)patients with suboptimal TKI response or intolerance.Methods Patients who did not have the best response or intolerance to first-line imatinib,dasatinib,and nilotinib and switched to flumatinib(600 mg/d)from February 2020 to August 2022 were collected from 5 hospitals from Chongqing and affiliated hospitals of North Sichuan Medical College.The efficacy and safety of flumatinib were observed.The optimal response rate,major molecular response(MMR),cumulative complete cytogenetic response(CCyR)rate,cumulative MMR rate,cumulative deep molecular response(DMR),progression-free survival(PFS),event-free survival(EFS)and adverse reactions in 3,6 and 12 months after treatment were observed and analyzed.Results A total of 100 patients with CML-CP were enrolled,with a median follow-up of 18(3～36)months.The optimal response rate was 92.6％(88/95),94.4％(85/90)and 92.9％(79/85)respectively,at 3,6 and 12 months after treatment.Till August 20,2023,the cumulative CCyR and MMR rate was 98.0％(98/100)and 81.9％(77/94),respectively,the median time to reach CCyR and MMR was 3 months,and cumulative DMR rate was 51.0％(51/100).PFS rate was 100.0％(100/100)and 1-year EFS rate was 85.6％(75/90).The most common non-hematologic adverse reactions of flumatinib were diarrhea and abdominal pain(7.0％),followed by renal dysfunction(6.0％)and musculoskeletal pain(2.0％).The main hematologic adverse reactions were thrombocytopenia(12.0％),anemia(6.0％)and leukopenia(2.0％).Conclusion Flumatinib has better MMR and DMR and is well tolerated in CML-CP patients with TKI resistance or intolerance.

Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.

Objective:To investigate the effects of unilateral ureteral obstruction on renal pelvic peristalsis and pacemaker cells in neonatal rats.Methods:An animal experimental study.Thirty-six 2-day-old newborn SD rats were randomly divided into the partial unilateral ureteral obstruction (PUUO) group, complete unilateral ureteral obstruction (CUUO) group, and sham operation group, with 12 rats in each group.One week after surgery, all rats were subjected to renal pelvic pressure (RPP) measurement by puncture.After measurement, the rats were euthanized, and their left renal pelvis and ureter were removed and fixed for histological examination.Parameters such as RPP, peristaltic wave frequency and amplitude at different perfusion speeds were recorded and compared, and the changes in pacemaker cells (atypical smooth muscle cells and Cajal-like interstitial cells) were also compared.The independent samples t-test was used for comparison between 2 groups, and the one-way ANOVA of variance was used for comparison among 3 groups. Results:In the sham operation group, the RPP increased gradually with the increase of perfusion speed; the frequency of peristaltic waves rose rapidly and then dropped after reaching the highest level with the increase of perfusion speed; similarly, the amplitude of peristaltic waves first increased and then decreased as the perfusion speed increased.In the PUUO group, the RPP increased rapidly with the increase of perfusion speed, higher than that in the sham operation group; the frequency of peristaltic waves was higher than that in the sham operation group, and it was relatively constant under the perfusion speed of 40 mL/h, but when the perfusion speed increased again, the frequency began to decline; the amplitude of peristaltic waves increased quickly and then declined at a faster rate than the sham operation group with the increase of perfusion speed.In the CUUO group, the basic RPP was 12 cmH 2O(1 cmH 2O=0.098 kPa); at the perfusion speed of 5 mL/h, the RPP rose gradually, and no plateau appeared; when the RPP reached 73 cmH 2O, the perfusate retrograded from the side of the puncture needle, then the RPP slightly decreased and then balanced, and no regular peristaltic waves were observed in the renal pelvis throughout the whole perfusion process.Immunofluorescence staining analysis showed the pacemaker cells were all located in the smooth muscle of the renal pelvic wall.The sham operation group had the highest positive rate, followed by the PUUO group and then the CUUO group. Conclusions:Ureteral obstruction has a significant impact on the peristalsis of the renal pelvis, and its impact on the peristaltic wave frequency and amplitude and RPP can be predicted.The reduction of pacemaker cells in the renal pelvis may be involved in the changes of renal pelvic peristalsis caused by ureteral obstruction, but further research is needed on how pacemaker cells regulate the peristalsis of the renal pelvis and ureter.

Objective To investigate the application value of quantitative relaxation parameters based on synthetic MRI technology in the differential diagnosis of parotid gland tumors.Methods Conventional MRI and synthetic MRI data of 59 patients with patho-logically confirmed parotid gland tumors were analyzed retrospectively.T1,T2,and proton density(PD)values of the tumor were extracted from T1,T2 and PD mapping.The differences in quantitative relaxation parameters of pleomorphic adenomas,Warthin tumors,and malignant tumors were further compared.Diagnostic performance of each quantitative relaxation parameter was assessed and com-pared via receiver operating characteristic(ROC)curve and DeLong test.Results T2 value was significantly higher in pleomorphic adenomas than that in malignant tumors(P<0.05).The T1,T2,and PD values of pleomorphic adenomas and malignant tumors were significantly higher than those of Warthin tumors(P<0.05).The area under the curve(AUC)of the T2 value in differentia-ting pleomorphic adenomas from malignant tumors was 0.794.The AUC for T1 value(0.939)in differentiating Warthin tumors from malignant tumors was significantly higher than that of T2(0.873,P=0.341)and PD(0.927,P=0.891)values,without sta-tistically significant difference.The AUC for T2 value(0.968)in differentiating pleomorphic adenomas from Warthin tumors was significantly higher than that of T1(0.931,P=0.360)and PD(0.876,P=0.120)values,without statistically significant difference.Conclusion Quantitative relaxation parameters based on synthetic MRI technology may contribute to differentiating pleomorphic adenomas,Warthin tumors,and malignant tumors of the parotid gland.

BACKGROUND:The stability of the pelvis is mainly determined by the posterior pelvic ring and the sacroiliac joint.The posterior pelvic ring injury and the dislocation of the sacroiliac joint caused by high energy impacts such as car accidents increase year by year.Surgical treatment is the best method,and there are many kinds of endophytorepair methods in clinical practice,but which treatment method has the best biomechanical properties is still controversial. OBJECTIVE:To compare the biomechanical properties of three kinds of internal implants:anterior double plates,posterior bridging plate and tension nail in the repair of unilateral unstable pelvic posterior ring injury,to provide a reference for the clinical treatment and development of a new pelvic tension screw. METHODS:(1)Finite element simulation:Mimics,Wrap and SolidWorks were used to establish normal pelvic model,unilateral injured pelvis model,and three kinds of internal implant repaired models(anterior double plates,posterior bridging plate and tension nail).Ansys was used to analyze the stress and deformation of the models.(2)Biomechanical test:A total of 15 intact pelvic specimens were randomly grouped into five groups,normal pelvic model,unilateral injured pelvis model,anterior double plates,posterior bridging plate and tension nail groups.The mechanical test was performed using an Instron E10000 testing machine. RESULTS AND CONCLUSION:(1)Simulation:In the normal pelvic model,the average displacement of the sacrum was 0.174 mm,and the maximum stress of the sacral iliac bone was 10.51 MPa,and the stress distribution was uniform.The mean sacral displacement of the unilateral injured pelvis model was 0.267 mm,and the stress concentration of the model was obvious.The mean displacement of the sacrum in the three repaired models was close to that in the normal pelvic model,and the stress distribution of the sacral iliac bone in the tension nail repaired model was uniform.(2)Mechanical test:The stiffness of the normal pelvic model was(226.38±4.18)N/mm,and that of the unilateral unstable pelvic model was the smallest(130.02±2.19)N/mm.The deviation of the normal pelvic model stiffness and the three repaired models'stiffness were all within(±10%),and the repair effect was obvious.(3)The simulation results were in agreement with the experimental results.(4)The biomechanics of the tension nail repaired model was the most similar to that of the normal pelvis,and this method was the best.The repairing stiffness of the anterior double plate was too large,and the stress shielding effect was more significant.The posterior bridging plate repair could not solve the compensatory effect of the normal side soft tissue and had defects.This study provides an optimal basis for clinical surgery.(5)The new type of pelvic tension nail should be improved from the point of view of the tension nail to retain the good biomechanical properties of the tension nail,while adding other advantages,such as being used for the osteoporotic pelvis.

Objective To summarize the epidemiological and clinical features of infectious diseases of the central nervous system(CNS)by a single-center analysis.Methods A retrospective analysis was conducted on the data of 1247 cases of CNS infectious diseases diagnosed and treated in the First Medical Center of PLA General Hospital from 2001 to 2020.Results The data for this group of CNS infectious diseases by disease type in descending order of number of cases were viruses 743(59.6％),Mycobacterium tuberculosis 249(20.0％),other bacteria 150(12.0％),fungi 68(5.5％),parasites 18(1.4％),Treponema pallidum 18(1.4％)and rickettsia 1(0.1％).The number of cases increased by 177 cases(33.1％)in the latter 10 years compared to the previous 10 years(P<0.05).No significant difference in seasonal distribution pattern of data between disease types(P>0.05).Male to female ratio is 1.87︰1,mostly under 60 years of age.Viruses are more likely to infect students,most often at university/college level and above,farmers are overrepresented among bacteria and Mycobacterium tuberculosis,and more infections of Treponema pallidum in workers.CNS infectious diseases are characterized by fever,headache and signs of meningeal irritation,with the adductor nerve being the more commonly involved cranial nerve.Matagenomic next-generation sequencing improves clinical diagnostic capabilities.The median hospital days for CNS infectious diseases are 18.00(11.00,27.00)and median hospital costs are ￥29,500(￥16,000,￥59,200).The mortality rate from CNS infectious diseases is 1.6％.Conclusions The incidence of CNS infectious diseases is increasing last ten years,with complex clinical presentation,severe symptoms and poor prognosis.Early and accurate diagnosis and standardized clinical treatment can significantly reduce the morbidity and mortality rate and ease the burden of disease.