The development of bone in human body and the maintenance of bone mass in adulthood are regulated by a variety of biological factors. Myocyte enhancer factor 2C (MEF2C), as one of the many factors regulating bone tissue development and balance, has been shown to play a key role in bone development and metabolism. However, there is limited systematic analysis on the effects of MEF2C on bone tissue. This article reviews the role of MEF2C in bone development and metabolism. During bone development, MEF2C promotes the development of neural crest cells (NC) into craniofacial cartilage and directly promotes cartilage hypertrophy. In terms of bone metabolism, MEF2C exhibits a differentiated regulatory model across different types of osteocytes, demonstrating both promoting and other potential regulatory effects on bone formation, with its stimulating effect on osteoclasts being determined. In view of the complex roles of MEF2C in bone tissue, this paper also discusses its effects on some bone diseases, providing valuable insights for the physiological study of bone tissue and strategies for the prevention of bone diseases.
Humans ; MEF2 Transcription Factors/physiology* ; Bone and Bones/metabolism* ; Animals ; Bone Development/physiology* ; Osteogenesis/physiology* ; Myogenic Regulatory Factors/physiology*

OBJECTIVE: To explore the optimal vertical traction weight, clinical efficacy, and safety of bidirectional cervical traction in the treatment of cervical kyphosis. METHODS: A total of 130 patients with neck pain and cervical kyphosis confirmed by cervical DR who visited the hospital from April 2023 to April 2024 were enrolled. They were divided into 4 groups according to the vertical traction weight accounting for 5%, 10%, 15%, and 20% of their body weight, respectively. The 5% body weight traction group included 33 cases (13 males and 20 females) with an average age of (34.00±10.58) years old;the 10% body weight traction group included 35 cases (17 males and 18 females) with an average age of (32.23±8.39) years old;the 15% body weight traction group included 32 cases (14 males and 18 females) with an average age of (33.88±10.09) years old;the 20% body weight traction group included 30 cases (11 males and 19 females) with an average age of (36.20±9.13) years old. Each group received treatment for 2 weeks. The visual analogue scale (VAS) score, neck disability index (NDI), and C₂-C₇ Cobb angle on cervical lateral X-ray films before and after treatment were recorded to evaluate the clinical efficacy of the 4 groups. RESULTS: When the traction weight was 10% and 15% of body weight, the pain VAS and NDI were significantly improved, and the C₂-C₇ Cobb angle increased, with statistically significant differences (P<0.05), and no adverse reactions occurred. However, in the 5% body weight group, the above indicators showed no significant changes, with no statistically significant differences (P>0.05). In the 20% body weight group, some patients could not tolerate the treatment, and adverse reactions such as dizziness, nausea, and aggravated neck pain occurred. CONCLUSION The optimal vertical traction weight of bidirectional cervical traction for cervical kyphosis is 10%-15% of body weight, which can effectively improve neck pain and cervical function, increase the C₂-C₇ Cobb angle of the cervical spine, with high safety, and is worthy of promotion and application.
Humans ; Male ; Female ; Traction/methods* ; Kyphosis/physiopathology* ; Adult ; Cervical Vertebrae/physiopathology* ; Middle Aged ; Neck Pain ; Young Adult

This study aimed to investigate the associations between the post-wash total progressively motile sperm count (TPMSC) in the first intrauterine insemination (IUI) cycle and pregnancy outcomes of the second IUI cycle. Data were retrieved from the clinical database at the Reproductive Center of Peking University Third Hospital (Beijing, China) between January 2011 and December 2022. Couples were included in this retrospective cohort study if they had unexplained or mild male factor infertility and were treated with IUI for two consecutive cycles using the same protocol. A total of 8290 couples were included in the analysis. The mean ± standard deviation (s.d.) age of women was 32.0 ± 3.5 years. We categorized groups based on the post-wash TPMSC (×10 6 ) levels in the first IUI cycle: group 1 (0 < TPMSC < 1, n = 1290), group 2 (1 ≤ TPMSC < 2, n = 863), group 3 (2 ≤ TPMSC < 3, n = 800), group 4 (3 ≤ TPMSC < 4, n = 783), group 5 (4 ≤ TPMSC < 5, n = 1541), group 6 (5 ≤ TPMSC < 6, n = 522), group 7 (6 ≤ TPMSC < 7, n = 547), group 8 (7 ≤ TPMSC < 8, n = 175), group 9 (8 ≤ TPMSC < 9, n = 556), group 10 (9 ≤ TPMSC < 10, n = 192), and group 11 (TPMSC ≥ 10), n = 1021). The primary outcome was live birth rate of the second IUI cycle. Live birth rates were 7.9%, 5.8%, 7.6%, 7.4%, 7.3%, 8.4%, 7.5%, 7.4%, 8.8%, 8.9%, and 7.6% in each group, respectively. There were no statistically significant differences in clinical pregnancy rates or live birth rates between any groups and those with the post-wash TPMSC <1 × 10 6 . In an IUI program for unexplained and mild male factor infertility, the post-wash TPMSC in the first IUI cycle was not significantly associated with the live birth rate in the second IUI cycle.
Humans ; Female ; Male ; Pregnancy ; Adult ; Retrospective Studies ; Sperm Count ; Pregnancy Rate ; Sperm Motility/physiology* ; Insemination, Artificial/methods* ; Pregnancy Outcome ; Infertility, Male/therapy* ; Insemination, Artificial, Homologous ; Live Birth

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics. Similarities and variations of components present significant analytical challenges. A two-dimensional (2D) liquid chromatography-mass spectrometr (LC-MS) method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium (CMS). A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated. For efficient and high-accuracy screening of CMS, a targeted method based on a self-constructed high resolution (HR) mass spectrum database of CMS components was established. The database was built based on the commercial MassHunter Personal Compound Database and Library (PCDL) software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening. On this basis, the unknown peaks in the CMS chromatograms were deduced and assigned. The molecular formula, group composition, and origins of a total of 99 compounds, of which the combined area percentage accounted for more than 95% of CMS components, were deduced by this 2D-LC-MS method combined with the MassHunter PCDL. This profiling method was highly efficient and could distinguish hundreds of components within 3 h, providing reliable results for quality control of this kind of complex drugs.

Objective To analyze the influencing factors of death in the elderly with coronavirus disease 2019(COVID-19).Methods The case data of death caused by COVID-19 in West China Fourth Hospital from January 1 to July 8,2023 were collected,and surviving cases from the West China Elderly Health Cohort infected with COVID-19 during the same period were selected as the control.LASSO-Logistic regression was adopted to analyze the data after propensity score matching and the validity of the model was verified by drawing the receiver operating characteristic curve.Results A total of 3 239 COVID-19 survivors and 142 deaths with COVID-19 were included.The results of LASSO-Logistic regression showed that smoking(OR=3.33,95%CI=1.46-7.59,P=0.004),stroke(OR=3.55,95%CI=1.15-10.30,P=0.022),malignant tumors(OR=19.93, 95%CI=8.52-49.23, P<0.001),coronary heart disease(OR=7.68, 95%CI=3.52-17.07, P<0.001),fever(OR=0.51, 95%CI=0.26-0.96, P=0.042),difficulty breathing or asthma symptoms(OR=21.48, 95%CI=9.44-51.95, P<0.001),and vomiting(OR=8.19,95%CI=2.87-23.58, P<0.001)increased the risk of death with COVID-19.The prediction model constructed based on the influencing factors achieved an area under the curve of 0.889 in the test set.Conclusions Smoking,stroke,malignant tumors,coronary heart disease,fever,breathing difficulty or asthma symptoms,and vomiting were identified as key factors influencing the death risk in COVID-19.
Humans ; COVID-19/mortality* ; Aged ; Propensity Score ; China/epidemiology* ; Risk Factors ; Logistic Models ; Smoking ; SARS-CoV-2 ; Male ; Female ; Stroke ; Neoplasms

In recent years, nucleic acid therapy, as a revolutionary therapeutic tool, has shown great potential in the treatment of genetic diseases, infectious diseases and cancer. Lipid nanoparticles (LNPs) are currently the most advanced mRNA delivery carriers, and their emergence is an important reason for the rapid approval and use of COVID-19 mRNA vaccines and the development of mRNA therapy. Currently, mRNA therapeutics using LNP as a carrier have been widely used in protein replacement therapy, vaccines and gene editing. Conventional LNP is composed of four components: ionizable lipids, phospholipids, cholesterol, and polyethylene glycol (PEG) lipids, which can effectively load mRNA to improve the stability of mRNA and promote the delivery of mRNA to the cytoplasm. However, in the face of the complexity and diversity of clinical diseases, the structure, properties and functions of existing LNPs are too homogeneous, and the lack of targeted delivery capability may result in the risk of off-targeting. LNPs are flexibly designed and structurally stable vectors, and the adjustment of the types or proportions of their components can give them additional functions without affecting the ability of LNPs to deliver mRNAs. For example, by replacing and optimizing the basic components of LNP, introducing a fifth component, and modifying its surface, LNP can be made to have more precise targeting ability to reduce the side effects caused by treatment, or be given additional functions to synergistically enhance the efficacy of mRNA therapy to respond to the clinical demand for nucleic acid therapy. It is also possible to further improve the efficiency of LNP delivery of mRNA through machine learning-assisted LNP iteration. This review can provide a reference method for the rational design of engineered lipid nanoparticles delivering mRNA to treat diseases.

Cyclin-dependent kinases (CDKs) are proline-induced serine/threonine kinases that are primarily involved in the regulation of cell cycle, gene transcription, and cell differentiation. In general, CDKs are activated by binding to specific regulatory subunits of cell cycle proteins and are regulated by phosphorylation of specific T-loops by CDK activated kinases. In the CDKs family, cyclin-dependent kinase 5 (CDK5) is a specialized member whose activity is triggered only by interaction with p35 and p39, which do not have the same sequence as the cell cycle proteins, and this may be one reason why CDK5 is distinguished from other CDK members by its structural and functional differences. In addition, unlike most CDK members that require phosphorylation at specific sites to function, CDK5 does not require such phosphorylation, and it can be activated simply by binding to p35 and p39. More notably, inhibitors that are commonly used to inhibit the activity of other CDK members have almost zero effect on CDK5. In contrast, CDK5, as a unique CDK family member, plays an important role in the development of numerous diseases. In metabolic diseases, elevated CDK5 expression leads to decreased insulin secretion, increased foam cell formation and triggers decreased bone mass in the body, thus accelerating metabolic diseases, and the role of CDK5 in bone biology is gradually gaining attention, and the role of CDK5 in bone metabolic diseases may become a hotspot for research in the future; in neurodegenerative diseases, hyperphosphorylation of Tau protein is an important hallmark of Alzheimer’s disease development, and changes in CDK5 expression are associated with Tau protein phosphorylation and nerve death, indicating that CDK5 is highly related to the development of the nervous system; in tumor diseases, the role of CDK5 in the proliferation, differentiation and migration and invasion of tumor cells marks the development of tumorigenesis, but different researchers hold different views, and further studies are needed in the follow-up. Therefore, the study of its mechanism of action in diseases can help to reveal the pathogenesis and pathological process of diseases. Appropriate exercise not only helps in the prevention of diseases, but also plays a positive role in the treatment of diseases. Exercise-induced mechanical stress can improve bone microstructure and increase bone mass in osteoporosis patients. In addition, exercise can effectively inhibit neuronal apoptosis and improve mitochondrial dysfunction, more importantly, appropriate exercise can inhibit the proliferation of cancer cells to a certain extent. It can be seen that exercise occupies a pivotal position in the prevention and treatment of pathologic diseases. It has been shown that exercise can reduce the expression of CDK5 and affect the pathological process of neurological diseases. Currently, there is a dearth of research on the specific mechanisms of CDK5’s role in improving disease outcomes through exercise. In order to understand its effects more comprehensively, subsequent studies need to employ diverse exercise modalities, targeting patients with various types of diseases or corresponding animal models for in-depth exploration. This article focuses on the pathological functions of CDK5 and its relationship with exercise, with a view to providing new insights into the prevention and treatment of disease by CDK5.

2-(4-Methylthiazol-5-yl) ethyl nitrate hydrochloride (W1302) is a nitro containing derivative of clomethiazole, which is a novel neuroprotective agent with both carbon monoxide (NO) donor and weak γ-aminobutyric acid type A (GABA_A) receptor allosteric regulatory excitatory effect. The current study used a rat model of transient middle cerebral arteryocclusion (tMCAO) brain injury to evaluate the therapeutic effect of W1302 on ischemic stroke and explore its potential mechanisms of action. This experiment has been reviewed and approved by the Laboratory Animal Management and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences (ethical review forms No. 620, 632, 5013). The results showed that gavage administration of 1, 3, and 10 mg·kg^-1 of W1302 can significantly reduce the volume of cerebral infarction in rats with ischemia for 2 h and reperfusion for 24 h, and the therapeutic effect was better than that of 200 mg·kg^-1 of DL-3n-butylphthalide. W1302 significantly increased NO levels in blood and brain tissue. It increased cerebral blood flow and brain adenosine triphosphate (ATP) content after reperfusion, as well as, inhibited the expressions of inflammatory factors tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in brain tissue. The time window of W1302 was between 120-180 min after ischemia. These research results demonstrated that W1302 could increase NO release, dilate blood vessels, and increase cerebral blood flow, improve energy supply to brain tissue and increase ATP levels, and inhibit neuro-inflammation, which playing the protective roles in tMCAO stroke model rats. This provides theoretical support for the clinical application of W1302 in the treatment of ischemic stroke.

Osteoporosis leads to an imbalance in bone remodelling, where bone resorption is greater than bone formation and osteoclast degradation increases, resulting in severe bone loss. Autophagy is a lysosomal degradation pathway that regulates the proliferation, differentiation, and apoptosis of various bone cells (including osteoblasts, osteoclasts, and osteoclasts), and is deeply involved in the bone remodelling process. In recent years, the role of autophagy in the progression of osteoporosis and related bone metabolic diseases has received more and more attention, and it has become a research hotspot in this field. Summarising the existing studies, it is found that senile osteoporosis is the result of a combination of factors. On the one hand, it is the imbalance of bone remodelling and the increase of bone resorption/bone formation ratio with ageing, which causes progressive bone loss. On the other hand, aging leads to a general decrease in the level of autophagy, a decrease in the activity of osteoblasts and osteoclasts, and an inhibition of osteogenic differentiation. The lack of oestrogen leads to the immune system being in a low activation state, and the antioxidant capacity is weakened and inflammatory response is increased, inducing autophagy-related proteins to participate in the transmission of inflammatory signals, excessive accumulation of reactive oxygen species (ROS) in the skeleton, and negatively regulating bone formation. In addition, with aging and the occurrence of related diseases, glucocorticoid treatments also mediate autophagy in bone tissue cells, contributing to the decline in bone strength. Exercise, as an effective means of combating osteoporosis, improves bone biomechanical properties and increases bone density. It has been found that exercise induces oxidative stress, energy imbalance, protein defolding and increased intracellular calcium ions in the organism, which in turn activates autophagy. In bone, exercise of different intensities activates messengers such as ROS, PI3K, and AMP. These messengers signal downstream cascades, which in turn induce autophagy to restore dynamic homeostasis in vivo. During exercise, increased production of AMP, PI3K, and ROS activate their downstream effectors, AMPK, Akt, and p38MAPK, respectively, and these molecules in turn lead to activation of the autophagy pathway. Activation of AMPK inhibits mTOR activity and phosphorylates ULK1 at different sites, inducing autophagy. AMPK and p38 up-regulate per-PGC-1α activity and activate transcription factors in the nucleus, resulting in increased autophagy and lysosomal genes. Together, they activate FoxOs, whose transcriptional activity controls cellular processes including autophagy and can act on autophagy key proteins, while FoxOs proteins are expressed in osteoblasts. Exercise also regulates the expression of mTORC1, FoxO1, and PGC-1 through the PI3K/Akt signalling pathway, which ultimately plays a role in the differentiation and proliferation of osteoblasts and regulates bone metabolism. In addition, BMPs signaling pathway and long chain non-coding RNAs also play a role in the proliferation and differentiation of osteoblasts and autophagy process under exercise stimulation. Therefore, exercise may become a new molecular regulatory mechanism to improve osteoporosis through the bone autophagy pathway, but the specific mechanism needs to be further investigated. How exercise affects bone autophagy and thus prevents and treats bone-related diseases will become a future research hotspot in the fields of biology, sports medicine and sports science, and it is believed that future studies will further reveal its mechanism and provide new theoretical basis and ideas.

AIM To study the extraction process,enzymatic properties and practical application of glucuronic hydrolase in Scutellaria baicalensis stems and leaves(sbsl GUS).METHODS With granularity,water consumption,extraction time and extraction frequency as influencing factors,enzymatic activity as an evaluation index,the extraction process was optimized by orthogonal test on the basis of single factor test.The relationship between substrate(baicalin)concentration and enzymolysis rate,after which Vmax and Km were calculated,the effects of pH value,temperature and metal ion on enzymatic activity were investigated,pH stability and heat stability were evaluated.sbsl GUS was adotped in the enzymolysis of baicalin to prepare baicalein,then the effects of pH value,temperature,reaction time,initial substrate concentration and enzyme addition on transfer rate were investigated.RESULTS The optimal extraction process was determined to be 40 mesh for granularity,10 times for water consumption,15 min for extraction time,and 3 times for extraction frequency.The enzymolysis accorded with the kinetics of enzymatic reaction,Km was 0.006 3 mol/L,Vmax was 70.42 μmol/h,the strongest enzymatic activity was found at the pH value of 6.0,temperature of 45℃and metal ion of 100 mmol/L Cu2+,sbsl GUS demonstrated good stability at the ranges of 4.0-7.0 for pH value and 4-30℃for temperature.The optimal preparation process was determined to be 6.0 for pH value,45℃for temperature,more than 12 h for reaction time,67.2 mmol/L for initial substrate concentration,and 1 mL/0.269 mmol baicalin for enzyme addition,the transfer rate was 97.83%.CONCLUSION sbsl GUS enzymolysis exhibits high efficiency and mild condition,which can provide a simple preparation method for obtaining baicalein,and expand the application path of Scutellaria baicalensis stems and leaves.