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.

OBJECTIVE To analyze the clinical characteristics of aplastic anemia （AA）/pure red cell aplasia （PRCA） induced by pembrolizumab， and provide reference for clinical safe drug use. METHODS Using search terms as “pembrolizumab”， “keytruda”， “anemia” and “aplastic anemia” in both Chinese and English， the literature related to AA/PRCA induced by pembrolizumab were retrieved from PubMed， Embase， CNKI， Wanfang and VIP databases， and then analyzed descriptively and statistically. RESULTS A total of 10 patients were included from 10 literature； among these 10 patients， there were 5 males and 5 females， with 5 patients being aged 65 or above. The primary disease was mainly metastatic melanoma （4 cases）. AA/PRCA occurred 13 d-3 years after the first dose of pembrolizumab. The main clinical manifestations included fatigue， dyspnea， oral/nasal bleeding， diffuse purpura， etc.； 8 cases developed moderate anemia and 2 cases developed severe anemia. After discontinuation and receiving supportive therapy， 5 cases improved， 1 case worsened in anemia， and 4 cases died. CONCLUSIONS When using pembrolizumab in clinical practice， blood routine should be regularly monitored. When AA/PRCA and other related symptoms occur， pembrolizumab should be stopped in time and a therapy regimen should be formulated according to the patient’ condition， to ensure the safety of medication.

Pulmonary electrical impedance tomography (EIT), a noninvasive, continuous, dynamic, and radiation-free bedside imaging technique for monitoring pulmonary ventilation, is now widely utilized in the diagnosis and management of critically ill patients. Beyond ventilation monitoring, hypertonic saline contrast-enhanced EIT for bedside pulmonary perfusion assessment has recently garnered significant attention. This article describes the application of hypertonic saline contrast-enhanced EIT to evaluate pulmonary perfusion in two patients following pulmonary endarterectomy, providing a reference for its perioperative application in such patients.

ObjectiveThe nucleolar protein PES1 (Pescadillo homolog 1) plays critical roles in ribosome biogenesis and cell cycle regulation, yet its involvement in cellular senescence remains poorly understood. This study aimed to comprehensively investigate the functional consequences of PES1 suppression in cellular senescence and elucidate the molecular mechanisms underlying its regulatory role. MethodsInitially, we assessed PES1 expression patterns in two distinct senescence models: replicative senescent mouse embryonic fibroblasts (MEFs) and doxorubicin-induced senescent human hepatocellular carcinoma HepG2 cells. Subsequently, PES1 expression was specifically downregulated using siRNA-mediated knockdown in these cell lines as well as additional relevant cell types. Cellular proliferation and senescence were assessed by EdU incorporation and SA-β-gal staining assays, respectively. The expression of senescence-associated proteins (p53, p21, and Rb) and SASP factors (IL-6, IL-1β, and IL-8) were analyzed by Western blot or qPCR. Furthermore, Northern blot and immunofluorescence were employed to evaluate pre-rRNA processing and nucleolar morphology. ResultsPES1 expression was significantly downregulated in senescent MEFs and HepG2 cells. PES1 knockdown resulted in decreased EdU-positive cells and increased SA‑β‑gal-positive cells, indicating proliferation inhibition and senescence induction. Mechanistically, PES1 suppression activated the p53-p21 pathway without affecting Rb expression, while upregulating IL-6, IL-1β, and IL-8 production. Notably, PES1 depletion impaired pre-rRNA maturation and induced nucleolar stress, as evidenced by aberrant nucleolar morphology. ConclusionOur findings demonstrate that PES1 deficiency triggers nucleolar stress and promotes p53-dependent (but Rb-independent) cellular senescence, highlighting its crucial role in maintaining nucleolar homeostasis and regulating senescence-associated pathways.

Aquaporin 5(AQP5),as the main water transport protein in the body,can regulate lung diseases by regulating airway mucus secretion,pulmonary inflammation,and lung function.Programmed cell death(PCD)plays a crucial role in chronic obstructive pulmonary disease(COPD).AQP5 may affect the development of COPD by regulating PCDs.This article reviews the molecular regulatory mechanism of AQP5 on apoptosis,autophagy,iron death and pyroptosis in PCDs in recent years,and further discusses its effect on COPD in order to provide theoretical support for clinical prevention and treatment of COPD.

Background Bisphenol compounds are non-persistent environmental endocrine disruptors and frequently detected in drinking water systems, indicating potential human health risks through drinking water. Objective To establish and optimize a simultaneous determination method for 16 BPs in drinking water by online solid-phase extraction-ultra high-performance liquid chromatography-triple quadrupole mass spectrometry, in order to efficiently monitoring BPs in drinking water. Methods Candidate online solid-phase extraction conditions, chromatographic columns, mobile phase systems, mass spectrometry parameters, and other conditions were compared by chromatographic peaks of BPs, and processing conditions such as water sample preservation and pretreatment were optimized. The pH level of drinking water samples was adjusted and solid particles were removed. After extraction and purification by an online solid-phase extraction system, samples were detected by ultra-high performance liquid chromatography tandem mass spectrometry and quantified by isotope internal standard method. The proposed method was verified by pure water and terminal tap water, and evaluated by spiked recovery rate and relative standard deviation. Eighty-eight tap water samples from different regions of local pipeline network were collected for method application. Results For the 16 BPs, the calibration curves showed good linearity between 1.0 and 75 ng·L⁻¹ and the correlation coefficients were greater than 0.995. The detection limit of the method was less than 0.30 ng·L⁻¹, and the quantification limit of the method was less than 1.0 ng·L⁻¹. When the spiked concentrations for the 16 BPs were 5.0, 15, and 40 ng·L⁻¹, the average spiked recovery rates of the test substances were between (100 ± 10)%, and the relative standard deviations were all below 10%. In the method application to the local terminal water samples, the positive rates of bisphenol S (BPS), bisphenol A (BPA), and bisphenol AF (BPAF) were as high as 93.2%, 77.3%, and 29.5%, respectively. The concentrations of BPS were from not detected (N.D.) to 37.8 ng·L⁻¹, and the concentrations of BPA were from N.D. to 52.0 ng·L⁻¹. Conclusion The method using an online solid-phase extraction system is established, featuring simple pre-treatment, small sample volume, high degree of automation, low detection limit, and good accuracy and precision. This method can be applied to the quantitative monitoring of 16 BPs at ng·L⁻¹ level in drinking water.

As the predominant toxic constituent within the Aconitum genus, Aconitum alkaloids (ATs) exhibit both significant pharmaceutical value and substantial toxicity, have been widely used in traditional Chinese medicine and the realm of contemporary clinical medicine. However, owing to their high toxicity, inappropriate employment of ATs in pharmaceuticals, edibles, and the environment will pose serious threats to human health, inciting a series of toxic incidents. Consequently, it is very important to develop effective analytical methods. This paper presents a comprehensive review of the advancements in research pertaining to the pretreatment and detection methods in common substrates, including high performance liquid chromatography, liquid chromatography-mass spectrometry and rapid detection methods. To explore the specific sources of ATs in actual poisoning cases, the comprehensive traceability strategy based on plant morphology, chemical fingerprint analysis and DNA barcoding technology was discussed, proposing a comprehensive prospect for the development of ATs analysis and traceability, in order to provide guidance for related research within the forensic science domain.

The pathogenesis of depression is complex, and some existing monoamine antidepressants have problems such as drug resistance or off-target failure. Traditional Chinese medicine has the characteristics of "multi-component and multi-target", and has been used in the treatment of depression in clinical practice. Yueju pill is effective in the treatment of depression. Geniposide and ligustrazine, the active ingredients of Gardeniae fructus and Ligusticum sinense 'Chuanxiong', play a key role in the treatment of depression. In this study, based on the neuroprotective activity of genipin and the rapid antidepressant activity of tetramethylpyrazine, a series of novel genipin derivatives were designed and synthesized through pharmacophore assembly principle, and their neuroprotective activity and antidepressant effect were investigated. The results showed that the novel genipin derivatives had well neuroprotective activity on the glutamate-induced HT-22 cell model, with compounds W-1 and W-3 showing better protective activity. In behavioral despair depression (BDD) model mice, compound W-3 was found to have better antidepressant activity than W-1 in tail suspension test and forced swimming test. Further study on the behavior of chronic unpredictable mild stress (CUMS) model mice showed that W-3 could significantly improve the depression-like behavior of model mice. All animal experiments were approved by the Experimental Animal Ethics Committee of Anhui University of Chinese Medicine (approval number: AHUCM-mouse-2022027). The effects of the preferred compound W-3 on protein kinase A (PKA), cAMP response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), 5-hydroxytryptamine 1A (5-HT_1A) receptor, N-methyl-D-aspartate ionic glutamate receptor 2A (GluN2A) and N-methyl-D-aspartate ionic glutamate receptor 2B (GluN2B) were analyzed by Western blot. W-3 treatment significantly up-regulated the protein expression of PKA, CREB, BDNF and 5-HT_1A, and down-regulated the protein expression of GluN2A and GluN2B. The results of qRT-PCR were consistent with those of Western blot. According to the above results, compound W-3 has a potential antidepressant effect, and its mechanism may be related to the activation of PKA-CREB-BDNF signaling pathway by regulating the expression of GluN2A, GluN2B and 5-HT_1A receptor proteins.

Objective To study the application of CE-Chirp in the evaluation of hearing impairment in forensic medicine by testing the auditory brainstem response(ABR)in adults using CE-Chirp to ana-lyze the relationship between the V-wave response threshold of CE-Chirp ABR test and the pure tone hearing threshold.Methods Subjects(aged 20-77 with a total of 100 ears)who underwent CE-Chirp ABR test in Changzhou De'an Hospital from January 2018 to June 2019 were selected to obtain the V-wave response threshold,and pure tone air conduction hearing threshold tests were conducted at 0.5,1.0,2.0 and 4.0 kHz,respectively,to obtain pure tone listening threshold.The differences and statistical differences between the average pure tone hearing threshold and V-wave response threshold were compared in different hearing levels and different age groups.The correlation,differences and statistical differences between the two tests at each frequency were analyzed for all subjects.The lin-ear regression equation for estimating pure tone hearing threshold for all subjects CE-Chirp ABR V-wave response threshold was established,and the feasibility of the equation was tested.Results There was no statistical significance in the CE-Chirp ABR response threshold and pure tone hearing threshold dif-ference between different hearing level groups and different age groups(P>0.05).There was a good correlation between adult CE-Chirp ABR V-wave response threshold and pure tone hearing threshold with statistical significance(P<0.05),and linear regression analysis showed a significant linear correla-tion between the two(P<0.05).Conclusion The use of CE-Chirp ABR V-wave response threshold can be used to evaluate subjects'pure tone hearing threshold under certain conditions,and can be used as an audiological test method for forensic hearing impairment assessment.

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.