BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

BACKGROUND:Exercises can reduce blood lipids and slow down the development of atherosclerosis.Atherosclerosis begins with mitochondrial dysfunction,and prohibitin 2 is involved in mitophagy by endurance training. OBJECTIVE:To explore the role of endurance training in the intervention of prohibitin 2 protein in the mitophagy autophagy pathway in atherosclerosis. METHODS:A total of 40 Wistar rats were randomly divided into control group,exercise group,atherosclerosis group and atherosclerosis combined with exercise group,with 10 rats in each group.A rat model of atherosclerosis was constructed by combining a high-fat diet(9 weeks)with vitamin D injections(weeks 1,3,and 6)in the latter two groups,while the two exercise groups were subjected to progressing intensity endurance training for 9 weeks.After the intervention,lipid and pathological detections were conducted to observe the modeling and interventional effects.Mitochondrial membrane potential and mitophagy proteins were detected by microplate reader and western blot.Immunofluorescence staining was used to observe the co-localization of mitophagy proteins in aortic tissue. RESULTS AND CONCLUSION:Lipid and pathological sections showed that compared with the atherosclerosis group,the serum low-density lipoprotein cholesterol and total cholesterol levels and aortic lipid deposition area were significantly reduced in the atherosclerosis combined with exercise group(P<0.001).The results of mitochondrial membrane potential showed that the significant decrease in mitochondrial membrane potential of the aorta in the atherosclerosis combined with exercise group was reversed(P<0.01).The results of western blot assay showed that compared with the control group,the mitochondrial protein expression of prohibitin 2,LC3Ⅱ/Ⅰ,PINK1 and Parkin was significantly increased(P<0.05),and the protein expression of PARL and PGAM5 decreased(P<0.05).Compared with the atherosclerosis group,the protein expression of PINK1 and Parkin in the mitchondria of rats in the atherosclerosis combined with exercise group was significantly decreased(P<0.05),and the protein expressions of prohibitin 2,LC3Ⅱ/Ⅰ,PARL and PGAM5 were significantly increased(P<0.05).Immunofluorescence results showed that compared with the control group,the co-localization of LC3 and PINK1 with TOMM20 was significantly increased in the atherosclerosis group(P<0.05),while compared with the atherosclerosis group,the co-localization of LC3 and PINK1 with TOMM20 was significantly increased in the atherosclerosis combined with exercise group(P<0.05).Co-localization of LC3 and PARL with prohibitin 2 was significantly increased in the atherosclerosis group compared with the control group(P<0.01),co-localization of LC3 with prohibitin 2 was significantly increased in the atherosclerosis combined with exercise group compared with the atherosclerosis group(P<0.01),and co-localization of PARL protein with prohibitin 2 was significantly decreased in the atherosclerosis combined with exercise group compared with the atherosclerosis group(P<0.01).To conclude,endurance training can induce the expression of prohibitin 2 in the inner mitochondrial membrane and promote the binding of prohibitin 2 to the mitophagy junction protein to complete mitophagy,restore mitochondrial function,and slow down the occurrence of atherosclerosis.

Objective To investigate the lifestyle and cardiovascular disease in the elderly and analyze their association. Methods A simple random sampling method was used to select the elderly aged 60 years and above in a community of Xining from September 2022 to September 2023 as the study subjects. General demographic characteristics, prevalence of cardiovascular disease, living habits and activity status were collected by questionnaire. Demographic characteristics and life behavior habits were compared between the diseased and non-diseased groups, and multivariate logistic regression was used to analyze the influencing factors of cardiovascular disease in the elderly. Results A total of 784 subjects, 259 (33.04%) suffered from cardiovascular disease, with coronary heart disease and hypertension being the most common. In terms of disease risk, males were 1.378 times higher than females, non-income groups were 1.394 times higher than income groups, receiving health education/popular science < 1 time/month groups were 1.533 times higher than ≥ 2 times/month groups, combined diabetes or obesity groups were 1.490 times and 1.470 times higher than non-diabetes or obesity groups, salty fresh taste groups were 1.690 times higher than light taste groups, fresh fruit intake frequency ≤ 3 times/week groups were 1.492 times higher than ＞7 times/week groups, smoking ≥ 30 cigarettes/month groups were 2.257 times higher than non-smoking groups, drinking ≥ 2 liquors or 500 ml beer/day groups were 1.569 times higher than non-drinking groups, irregular physical examination habits groups were 1.619 times higher than regular physical examination habits groups, aerobic exercise did not reach the standard groups were 1.454 times higher than the standard groups. Conclusion Lifestyle is associated with cardiovascular disease in the elderly. It is important to carry out targeted health education and advocate healthy behavior lifestyle to prevent and treat cardiovascular disease.

Tracheobronchial adenoid cystic carcinoma （TACC） is a low-grade malignant tumor originating from the airway mucosa. Despite its slow progression，it is characterized by high invasiveness，frequent recurrence，and a strong tendency for metastasis. Preclinical studies have shown that vascular-targeted therapy holds significant potential. However，an effective systemic treatment for TACC has not been established yet. This study explored TACC from the perspective of "Feiji" in traditional Chinese medicine （TCM） as the starting point. It deeply investigated the mechanisms of abnormal collaterals and tumor vascular recruitment and further elaborated on the theoretical connection between abnormal collaterals and tumor vascular recruitment. Firstly，collateral hyperactivity led to disordered and erratic pulmonary collaterals. Their abnormal structures were similar to the disorderly and tortuous nature of tumor （pseudo）angiogenesis. This resulted in imbalances in the functions of circulation，perfusion，and reverse injection of the pulmonary collaterals，and then led to unrestrained collateral dysfunction and the accumulation of pathogenic factors. Secondly，the remodeling of the extracellular matrix （ECM） and epithelial-mesenchymal transition （EMT） in TACC were critical processes in vascular co-option （VCO），representing the micro-level manifestation of the displacement of nutrient and defense. During this process，ECM remodeling made TACC cells more likely to hijack normal blood vessels，creating a complex vascular microenvironment conducive to tumor growth. In terms of treatment，this study proposed a TCM strategy of "regulating collaterals to expel pathogenic factors and nourishing collaterals to strengthen the healthy Qi"，and listed potential TCM. These were intended to regulate the Qi and blood in the collaterals，repair the functions of abnormal collaterals，and intervene in the vascular recruitment process of TACC. Future research should focus on improving the TCM clinical syndrome characteristics of TACC. Through modern molecular biology techniques，it is necessary to deeply analyze the micro-level pattern of vascular recruitment in TACC. This would enrich the understanding of the profound connection between abnormal collaterals and tumor vascular recruitment，providing empirical evidence for TCM-targeted therapies for vascular recruitment in TACC.

AIM: To delineate the specific mutation responsible for retinitis pigmentosa(RP)in a Yi pedigree, and to analyze the correlation of RHO gene mutation with clinical phenotype.METHODS:A comprehensive clinical evaluation was conducted on the proband diagnosed with RP and other familial members, complemented by a thorough ophthalmic examination. Peripheral blood samples were obtained from the proband and familial members, from which genomic DNA was extracte. Subsequent whole exome sequencing(WES)was employed to identify the variant genes in the proband. The identified variant gene was validated through Sanger sequencing, then an in-depth analysis of the mutation genes was carried out using genetic databases to ascertain the pathogenic mutation sites. Furthermore, an exhaustive analysis was performed to delineate the genotype and phenotype characteristics.RESULTS:The RP pedigree encompasses 5 generations with 42 members, including 19 males and 23 females. A total of 13 cases of RP were identified, consisting of 4 males and 9 females, which conforms to the autosomal dominant inheritance pattern. The clinical features of this family include an early onset age, rapid progression, and a more severe condition. The patients were found to have night blindness around 6 years old, representing the earliest reported case of night blindness in RP families. The retina was manifested by progressive osteocytoid pigmentation of the fundus, a reduced visual field, and significantly decreased or even vanished a and b amplitudes of ERG. The combined results of WES and Sanger sequencing indicated that the proband had a heterozygous missense mutation of the RHO gene c.1040C>T:p.P347L, where the 1 040 base C of cDNA was replaced by T, causing codon 347 to encode leucine instead of proline. Interestingly, this mutation has not been reported in the Chinese population.CONCLUSION:This study confirmed that the mutant gene of RP in a Yi nationality pedigree was RHO(c.1040C>T). This variant leads to the change of codon 347 from encoding proline to encoding leucine, resulting in a severe clinical phenotype among family members. This study provides a certain molecular, clinical, and genetic basis for genetic counseling and gene diagnosis of RHO.

AIM: To delineate the specific mutation responsible for retinitis pigmentosa(RP)in a Yi pedigree, and to analyze the correlation of RHO gene mutation with clinical phenotype.METHODS:A comprehensive clinical evaluation was conducted on the proband diagnosed with RP and other familial members, complemented by a thorough ophthalmic examination. Peripheral blood samples were obtained from the proband and familial members, from which genomic DNA was extracte. Subsequent whole exome sequencing(WES)was employed to identify the variant genes in the proband. The identified variant gene was validated through Sanger sequencing, then an in-depth analysis of the mutation genes was carried out using genetic databases to ascertain the pathogenic mutation sites. Furthermore, an exhaustive analysis was performed to delineate the genotype and phenotype characteristics.RESULTS:The RP pedigree encompasses 5 generations with 42 members, including 19 males and 23 females. A total of 13 cases of RP were identified, consisting of 4 males and 9 females, which conforms to the autosomal dominant inheritance pattern. The clinical features of this family include an early onset age, rapid progression, and a more severe condition. The patients were found to have night blindness around 6 years old, representing the earliest reported case of night blindness in RP families. The retina was manifested by progressive osteocytoid pigmentation of the fundus, a reduced visual field, and significantly decreased or even vanished a and b amplitudes of ERG. The combined results of WES and Sanger sequencing indicated that the proband had a heterozygous missense mutation of the RHO gene c.1040C>T:p.P347L, where the 1 040 base C of cDNA was replaced by T, causing codon 347 to encode leucine instead of proline. Interestingly, this mutation has not been reported in the Chinese population.CONCLUSION:This study confirmed that the mutant gene of RP in a Yi nationality pedigree was RHO(c.1040C>T). This variant leads to the change of codon 347 from encoding proline to encoding leucine, resulting in a severe clinical phenotype among family members. This study provides a certain molecular, clinical, and genetic basis for genetic counseling and gene diagnosis of RHO.

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

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.

Electromagnetic fields can regulate the fundamental biological processes involved in bone remodeling. As a non-invasive physical therapy, electromagnetic fields with specific parameters have demonstrated therapeutic effects on bone remodeling diseases, such as fractures and osteoporosis. Electromagnetic fields can be generated by the movement of charged particles or induced by varying currents. Based on whether the strength and direction of the electric field change over time, electromagnetic fields can be classified into static and time-varying fields. The treatment of bone remodeling diseases with static magnetic fields primarily focuses on fractures, often using magnetic splints to immobilize the fracture site while studying the effects of static magnetic fields on bone healing. However, there has been relatively little research on the prevention and treatment of osteoporosis using static magnetic fields. Pulsed electromagnetic fields, a type of time-varying field, have been widely used in clinical studies for treating fractures, osteoporosis, and non-union. However, current clinical applications are limited to low-frequency, and research on the relationship between frequency and biological effects remains insufficient. We believe that different types of electromagnetic fields acting on bone can induce various “secondary physical quantities”, such as magnetism, force, electricity, acoustics, and thermal energy, which can stimulate bone cells either individually or simultaneously. Bone cells possess specific electromagnetic properties, and in a static magnetic field, the presence of a magnetic field gradient can exert a certain magnetism on the bone tissue, leading to observable effects. In a time-varying magnetic field, the charged particles within the bone experience varying Lorentz forces, causing vibrations and generating acoustic effects. Additionally, as the frequency of the time-varying field increases, induced currents or potentials can be generated within the bone, leading to electrical effects. When the frequency and power exceed a certain threshold, electromagnetic energy can be converted into thermal energy, producing thermal effects. In summary, external electromagnetic fields with different characteristics can generate multiple physical quantities within biological tissues, such as magnetic, electric, mechanical, acoustic, and thermal effects. These physical quantities may also interact and couple with each other, stimulating the biological tissues in a combined or composite manner, thereby producing biological effects. This understanding is key to elucidating the electromagnetic mechanisms of how electromagnetic fields influence biological tissues. In the study of electromagnetic fields for bone remodeling diseases, attention should be paid to the biological effects of bone remodeling under different electromagnetic wave characteristics. This includes exploring innovative electromagnetic source technologies applicable to bone remodeling, identifying safe and effective electromagnetic field parameters, and combining basic research with technological invention to develop scientifically grounded, advanced key technologies for innovative electromagnetic treatment devices targeting bone remodeling diseases. In conclusion, electromagnetic fields and multiple physical factors have the potential to prevent and treat bone remodeling diseases, and have significant application prospects.

ObjectivePhotoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected. MethodsThe advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively. ResultsIn the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice. ConclusionThis work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.