Spermatogenesis is a highly ordered and spatiotemporally regulated developmental process in the male reproductive system, during which spermatogonial stem cells (SSCs), supported by the seminiferous tubule microenvironment, sequentially undergo mitosis, meiosis, and spermiogenesis to ultimately generate structurally intact spermatozoa. This complex process is accompanied by extensive transcriptional reprogramming, chromatin remodeling, and finely tuned post-transcriptional regulation. Precise control of RNA fate is therefore essential for maintaining the continuity and fidelity of spermatogenesis, and its disruption represents a major molecular basis of male infertility. N⁶-methyladenosine (m⁶A), the most abundant internal RNA modification in eukaryotes, has emerged as a critical regulator of post-transcriptional gene expression. m⁶A methyltransferases (“writers”) catalyze the addition of a methyl group to the N⁶ position of adenosine, m⁶A demethylases (“erasers”) remove the modification, and m⁶A-binding proteins (“readers”) recognize m⁶A-modified transcripts. Through the coordinated actions of these factors, m⁶A regulates transcript fate at multiple levels, including RNA splicing, nuclear export, stability, translation, and decay. Emerging evidence indicates that m⁶A-mediated regulation is essential across multiple stages of spermatogenesis, including SSC self-renewal and differentiation, meiotic progression, maintenance of chromosomal stability, and sperm morphogenesis. Beyond its intrinsic functions in germ cells, m⁶A also contributes to the regulation of the testicular microenvironment. In sertoli cells, m⁶A is involved in maintaining blood-testis barrier integrity, RNA processing, and paracrine signaling, thereby providing structural and metabolic support for germ cell development. In Leydig cells, m⁶A regulates steroidogenesis, particularly testosterone synthesis, and participates in cellular stress responses and metabolic homeostasis. Through these mechanisms, m⁶A indirectly influences spermatogenesis by modulating the functional state of testicular somatic cells, highlighting an integrated regulatory mode that combines cell-intrinsic and microenvironment-mediated effects. Notably, distinct classes of m⁶A regulators exhibit pronounced stage-specific functions and coordinated division of labor, collectively forming a multilayered and dynamic regulatory network. Writers often display dosage- and temporal window-dependent effects; erasers contribute to stage-specific demethylation and functional compensation; while readers function through a “switch-buffer” dual-layer architecture, and RNA-binding proteins (RBPs) participate in substrate selection and post-transcriptional regulation. Importantly, emerging evidence suggests that some m⁶A-related proteins can function through noncanonical mechanisms independent of m⁶A recognition, such as intrinsic RNA-binding activity, helicase function, or ribonucleoprotein complex assembly, thereby expanding the functional landscape of the m⁶A regulatory system. Dysregulation of m⁶A machinery can lead to multiple spermatogenic defects, including impaired SSC self-renewal, meiotic arrest, abnormal chromatin remodeling, and defective sperm formation, ultimately resulting in male infertility. Despite substantial advances, several critical questions remain unresolved, including the distinction between m⁶A-dependent and -independent mechanisms, the spatiotemporal dynamics of m⁶A modifications at single-cell resolution, and the coordination and antagonism among different regulatory factors. In this review, we systematically summarize the dual regulation of spermatogenesis by germ cell-intrinsic mechanisms and the testicular microenvironment, and delineate the molecular mechanisms and stage-specific functions of the dynamic m⁶A regulatory network. We further discuss the current limitations in the field and propose feasible experimental strategies for future investigation. Collectively, this work aims to provide a comprehensive framework for understanding the epitranscriptomic regulation of spermatogenesis and to offer theoretical insights into the pathogenesis and clinical management of male infertility.

Spermatogenesis is a highly ordered and spatiotemporally regulated developmental process in the male reproductive system, during which spermatogonial stem cells (SSCs), supported by the seminiferous tubule microenvironment, sequentially undergo mitosis, meiosis, and spermiogenesis to ultimately generate structurally intact spermatozoa. This complex process is accompanied by extensive transcriptional reprogramming, chromatin remodeling, and finely tuned post-transcriptional regulation. Precise control of RNA fate is therefore essential for maintaining the continuity and fidelity of spermatogenesis, and its disruption represents a major molecular basis of male infertility. N⁶-methyladenosine (m⁶A), the most abundant internal RNA modification in eukaryotes, has emerged as a critical regulator of post-transcriptional gene expression. m⁶A methyltransferases (“writers”) catalyze the addition of a methyl group to the N⁶ position of adenosine, m⁶A demethylases (“erasers”) remove the modification, and m⁶A-binding proteins (“readers”) recognize m⁶A-modified transcripts. Through the coordinated actions of these factors, m⁶A regulates transcript fate at multiple levels, including RNA splicing, nuclear export, stability, translation, and decay. Emerging evidence indicates that m⁶A-mediated regulation is essential across multiple stages of spermatogenesis, including SSC self-renewal and differentiation, meiotic progression, maintenance of chromosomal stability, and sperm morphogenesis. Beyond its intrinsic functions in germ cells, m⁶A also contributes to the regulation of the testicular microenvironment. In sertoli cells, m⁶A is involved in maintaining blood-testis barrier integrity, RNA processing, and paracrine signaling, thereby providing structural and metabolic support for germ cell development. In Leydig cells, m⁶A regulates steroidogenesis, particularly testosterone synthesis, and participates in cellular stress responses and metabolic homeostasis. Through these mechanisms, m⁶A indirectly influences spermatogenesis by modulating the functional state of testicular somatic cells, highlighting an integrated regulatory mode that combines cell-intrinsic and microenvironment-mediated effects. Notably, distinct classes of m⁶A regulators exhibit pronounced stage-specific functions and coordinated division of labor, collectively forming a multilayered and dynamic regulatory network. Writers often display dosage- and temporal window-dependent effects; erasers contribute to stage-specific demethylation and functional compensation; while readers function through a “switch-buffer” dual-layer architecture, and RNA-binding proteins (RBPs) participate in substrate selection and post-transcriptional regulation. Importantly, emerging evidence suggests that some m⁶A-related proteins can function through noncanonical mechanisms independent of m⁶A recognition, such as intrinsic RNA-binding activity, helicase function, or ribonucleoprotein complex assembly, thereby expanding the functional landscape of the m⁶A regulatory system. Dysregulation of m⁶A machinery can lead to multiple spermatogenic defects, including impaired SSC self-renewal, meiotic arrest, abnormal chromatin remodeling, and defective sperm formation, ultimately resulting in male infertility. Despite substantial advances, several critical questions remain unresolved, including the distinction between m⁶A-dependent and -independent mechanisms, the spatiotemporal dynamics of m⁶A modifications at single-cell resolution, and the coordination and antagonism among different regulatory factors. In this review, we systematically summarize the dual regulation of spermatogenesis by germ cell-intrinsic mechanisms and the testicular microenvironment, and delineate the molecular mechanisms and stage-specific functions of the dynamic m⁶A regulatory network. We further discuss the current limitations in the field and propose feasible experimental strategies for future investigation. Collectively, this work aims to provide a comprehensive framework for understanding the epitranscriptomic regulation of spermatogenesis and to offer theoretical insights into the pathogenesis and clinical management of male infertility.

Objective:To analyze the learning curve of TiRobot-assisted lumbar pedicle screw fixation (LPSF) by cumulative sum (CUSUM) test method.Methods:The clinical data of 50 patients who underwent TiRobot-assisted LPSF from January 2020 to December 2022 in Beijing Friendship Hospital, Capital Medical University were retrospectively analyzed. CUSUM analysis and learning curve fitting were performed with robot usage time as the main indicator with the time for each step refined (robot registration time, path planning time and guide wire placement time), to select the best learning curve fitting model with the R2 value closest to 1. Using the turning point of the learning curve as the boundary, the learning curve was divided into two stages as learning stage and maturity stage, and then the observation indexes were compared between the two stages. Results:All 50 patients successfully completed the surgery without perioperative complications, with a total of 244 pedicle screws implanted. The total robot usage time and robot registration time showed a gradually decreasing trend with the increase of case number, and the learning curves were successfully fitted and reached their peaks at the seventeenth and thirteenth cases respectively. The entire learning process was divided into learning stage (17 cases) and maturity stage (33 cases) based on the turning point of the learning curve of total robot usage time. The path planning time and guide wire placement time did not show significant changes with the increase in the case number. The total robot usage time, robot registration time and the intraoperative blood loss in the learning stage were significantly higher than those in the maturity stage: (35.35 ± 1.58) min vs. (30.61 ± 0.43) min, (20.83 ± 1.56) min vs. (14.94 ± 0.29) min and 400 (150, 500) ml vs. 200 (110, 300) ml, the guide wire placement time of per screw was significantly lower than that in the maturity stage: 2.00 (1.83, 2.34) min/screw vs. 2.33 (2.13, 2.69) min/screw, and there were statistical differences ( P<0.05 or <0.01). There were no statistical difference in the path planning time, path planning time of per screw, guide wire placement time and the accuracy of screw placement between two stages ( P>0.05). Conclusions:TiRobot-assisted LPSF is a new technology with safety and effectiveness, and it has a relatively short learning curve. To achieve technological maturity, at least 17 surgeries are required with accumulated experience, and the robot registration is the main step of the learning process. After reaching maturity stage, the robot usage time is significantly shortened and intraoperative trauma is significantly reduced while the relatively high screw placement accuracy is ensured.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

Objective:To explore the biological efficacy and molecular mechanism of the new 6449Da active peptide against gastric adenocarcinoma.Methods:Effect 6449Da active peptides on SGC-7901 gastric adenocarcinoma cells line was studied and mRNA and protein expression levels of key factors relating to apoptosis, proliferation and notch signaling pathway was detcted.Results:The 6449Da functional fragment WSGC peptide located on the cell membrane relatively specifically inhibited the growth of gastric adenocarcinoma cells, but had a weak effect on normal gastric mucosal cells [cell doubling time , SGC-7901, 1.2 μmol/ml: (38.22±6.80) h vs. 0 μmol/ml: (25.65±1.82) h, P<0.05; GES-1, 1.2 μmol/ml: (33.37±3.15) h vs. 0 μmol/ml: (29.25±1.26) h, P>0.05].After treatment of SGC-7901 cells by IC80 (48 h),the cell apoptosis rate was higher than that in the control group (IC80: 0.421±0.036 vs. control group: 0.028±0.004, P<0.001), while the cell proliferation coefficient,number of transmembrane invasive cells and relative migration rate were all lower than those of the control group (all P<0.01).Compared with the control group, the mRNA and protein expression levels of Bax and Caspase-3 were higher than those in the control group(all P<0.01).Compared with the control group, the mRNA and protein expression levels of Ki67, PCNA, NOTCH1,Jagged 1, MAML3, CSL and HES1 were significantly lower than those in the control group (all P<0.01).After treatment with WSGC bioactive peptides, tumor weight was significantly lower than that of the control group [40 nmol/g: (0.463±0.031) g, 80 nmol/g: (0.340±0.040) g vs. control group: (1.667±0.373) g, all P<0.01]. Conclusion:6449Da functional fragment WSGC active peptide relatively specifically interferes with the growth of gastric adenocarcinoma cells by inhibiting the Notch signaling pathway, and has the biological effects of promoting apoptosis,inhibiting proliferation, transmembrane invasion and migration.

ObjectiveTo analyze the epidemiological and clinical characteristics of pertussis in Baoshan District, Shanghai from 2017 to 2024, so as to provide an evidence-based reference for optimizing prevention and control strategies. MethodsData on pertussis cases were collected from the China Disease Prevention and Control Information System, Shanghai Integrated Management and Immunization Service Information System, and follow-up epidemiological investigations. Descriptive epidemiological analyses were performed to analyze the epidemiological characteristics, clinical manifestations, and vaccine effectiveness. Joinpoint regression analyses were used to examine the temporal trends in incidence rates, and a Poisson model was constructed for spatiotemporal scan analyses. ResultsA total of 1 634 pertussis cases were reported in Baoshan District from 2017 to 2024, with a male-to-female ratio of 1.08∶1. More cases were observed in males than in females, with the age ranged from 20 days to 81 years. Among them, 59.92% were in the 6‒<11 years age group, and 63.34% were students. Low-level sporadic incidence persisted during 2017‒2023, followed by a sharp increase in 2024 (71.37/100 000). Starting in January 2024, the incidence rate showed an upward trend, peaking in May before declining. The majority of cases occurred between April and June. The trend in reported pertussis incidence rates in Baoshan District from 2017 to 2023 showed no statistically significant change (APC=10.039%, t=2.586, P=0.150). Incidence rate rose from January 2024, peaked in May (APC=133.641%, t=3.841, P=0.006), then declined significantly (APC=-47.816%, t=2.586, P<0.001). The 12 subdistricts of Baoshan District were divided into low, medium, and high population density areas, with an average annual reported incidence rate of 6.09/100 000, 8.19/100 000 and 11.96/100 000, respectively. The reported incidence rate increased with an increase in population density. Spatiotemporal scan analyses showed that cases clustered in the southwest and northeast of Baoshan District. Epidemiological follow-up investigations of 1 520 cases revealed that the main clinical symptoms were cough (97.63%) and sputum production (41.58%), and 98.13% of the cases were confirmed by positive nucleic-acid test results. Among the 1 475 cases with immunization records, 83.53% had completed the four-dose pertussis vaccine before onset. The complication incidence rates, from high to low, were in the 0-dose vaccination group, 1‒3-dose vaccination group and 4-dose vaccination group. The duration of cough, from long to short, was observed in the the 0-dose vaccination group, 1‒3-dose vaccination group and 4-dose vaccination group, correspondingly. ConclusionIt is recommended to improve the pertussis surveillance system in medical institutions and establish an active monitoring network, prioritizing deployment in school settings and areas with high population density. Enhancing diphtheria-tetanus-pertussis (DTP) vaccination coverage among 6-year-old children and further optimizing the pertussis immunization strategies are essential to prevent and reduce the risk of pertussis among school-aged children.

Objective:To evaluate the perioperative application effect of enhanced recovery after surgery (ERAS) clinical pathway in percutaneous vertebro plasty (PVP).Methods:The clinical data of 274 patients who underwent PVP treatment for osteoporotic vertebral compression fracture (OVCF) in Beijing Friendship Hospital, Capital Medical University from May 2023 to August 2024 were retrospectively analyzed. The patients were divided into two groups according to the different numbers of surgical segments: the single-segment group ( n=211) and the multisegment group ( n=63). Patients in the single-segment group underwent single-segment surgery, while patients in the multisegment group underwent surgery on ≥2 segments. The core points of the ERAS clinical pathway adopted in this study include perioperative education, pain management, early mobilization, application of "outfast", and joint guidance from the departments of nutrition and rehabilitation. Comparison was made between the two groups of patients in terms of visual analog scale (VAS) scores for low back pain at preoperative, 2 h, 6 h, 24 h postoperatively, and on the day of discharge; Oswestry disability index (ODI) scores preoperatively and on the day of discharge; time to first ambulation postoperatively, total length of hospital stay, postoperative length of stay, perioperative complications, and perioperative application of Opioid consumption. Measurement data were expressed as mean±standard deviation ( ± s), and the independent sample t-test was used for comparison between groups; count data were expressed as cases and percentage, and the Chi-square test was used for comparison between groups. The VAS pain scores at each stage of the perioperative period were evaluated using repeated measures analysis of variance or generalized estimating equations. Results:Compared with that before the operation [(6.17±0.93) points, (6.29±0.83) points], the VAS scores of low back pain of patients in the single-segment group and the multisegment group at 2 hours after surgery [(3.09±0.82) points, (3.27±0.65) points], 6 hours after surgery [(2.60±0.79) points, (2.62±0.55) points], and 24 hours after surgery [(1.89±0.77) points, (1.97±0.72) points] and on the day of discharge [(1.72±0.71) points, (1.81±0.64) points] were significantly decreased, and the differences were statistically significant ( P<0.05). At the same stage, the VAS scores of low back pain in both groups were not statistically significant ( P>0.05). The ODI scores of patients in the single-segment group and the multisegment group on the day of discharge [(24.21±2.35) points, (24.63±3.31) points] were significantly lower than those before the operation [(64.50±4.81) points, (65.52±4.08) points], and the differences were statistically significant ( P<0.05). There were no statistically significant differences in perioperative complications and the proportion of Opioid drug application between the two groups of patients ( P>0.05). Conclusion:For patients with single-segment or multisegment OVCF, PVP surgical treatment under ERAS clinical pathway management can achieve immediate pain relief, early ambulation exercise, and satisfactory perioperative efficacy.

Objective:To evaluate preoperative malnutrition risk in patients with osteoporotic vertebral compression fracture (OVCF) based on mini nutritional assessment short form (MNA-SF) and analyze the related clinical risk factors.Methods:A cross-sectional study was conducted using clinical data from 129 OVCF patients who underwent percutaneous vertebroplasty at Beijing Friendship Hospital, Capital Medical University, between May 2023 and December 2023. The cohort included 26 males and 103 females, aged (74.71±9.13) years(ranging from 48-98 years). According to MNA-SF scoring method, they were divided into three groups, the malnutrition group ( n=6), the nutritional risk group ( n=40), and the good nutrition group ( n=83). Nutritional risk and malnutrition rates were evaluated using the MNA-SF score. Measurement data with normal distribution were expressed as mean±standard deviation ( ± s) and compared using one-way ANOVA. The comparison between groups of count data was conducted using chi-square test. Univariate analysis and multivariate logistic regression were performed to identify independent risk factors for malnutrition and nutritional risk. Results:According to the MNA-SF score, among 129 patients, the malnutrition rate was 4.7%, the nutritional risk rate was 31.0%, and 64.3% exhibited adequate nutrition based on MNA-SF scores. The results of one-way ANOVA showed that gender ( P=0.023) and BMI ( P<0.001) were significantly correlated with malnutrition and nutritional risk; Logistic regression analysis suggested that the influencing factors of nutritional risk included gender ( P=0.002) and BMI ( P<0.001), while the only dangerous factor of malnutrition was BMI ( P<0.001). Conclusions:Bsed on MNA-SF, OVCF patients undergoing percutaneous vertebroplasty have a higher incidence of malnutrition and nutritional risk. The risk factors for nutritional risk in patients are gender and BMI, while the risk factor for malnutrition is only BMI.

Objective To explore the feasibility and corresponding implementation methods of constructing a sample resource bank based on individual-level data of completed clinical trials and using it to construct external controls for drug/device clinical trials.Methods Taking the pre-marketing clinical trial of transcatheter active valve replacement(TAVR)for the treatment of aortic valve stenosis as an example,the individual-level databases of multiple trials were standardized to form a sample bank.The original data of any trial in the sample bank were selected as the experimental group,and the remaining samples were selected as the control group.The potential confounding was handled by using the propensity score matching and stratification methods to clarify the process of constructing external controls based on the sample bank of individual-level data of clinical trials.Results This study included individual-level data of single-group trials of 4 TAVR devices,with a total of 569 subjects(59.2%male).The number of subjects in Trials 1 to 4 was 120,120,163,and 166,respectively.Propensity score matching enabled the matching of 113,117,125,and 147 subjects with comparable or similar characteristics from individual-level data from other trials,respectively,demonstrating a high matching success rate.The PS score distribution plot after stratification showed that the proportions of subjects in the experimental and control groups in strata 1 to 5 in scheme 1 were 4/103,11/103,22/92,32/87,and 51/64,respectively.For all constructed external controlled trials,a certain number of control samples with similar baseline characteristics to the experimental groups were distributed within each propensity score stratum.The results of the simulation test also reflected the potential differences between different devices in the 12-month all-cause mortality rate.Conclusions The sample bank constructed with individual-level data from clinical trials,as a high-quality data source,can serve as a source of external control for single-arm trials in the same field,and as a useful supplement to the external control scenario of real-world evidence to support drug and device development.At the same time,targeted research on research methods and bias control measures in related fields is also needed.

Hypercholesterolemia is pathologically characterized by abnormal accumulation of low-density lipoprotein cholesterol,which is closely associated with metabolic dysfunction-associated fatty liver disease and increased cardiovascular risks.Hepatocytes maintain cholesterol homeostasis through LDL receptor-mediated uptake and esterification storage mechanisms.However,chronic cholesterol overload induces mitochondrial dysfunction,reactive oxygen species accumulation,and endoplasmic reticulum stress,leading to hepatocyte injury.Moreover,systemic hypercholesterolemia disrupts gut microbiota balance and impairs short-chain fatty acid and ketone metabolism,exacerbating metabolic disturbances and aggravating hepatic injury through enhanced metabolic stress.In this article,we review the advance of studies on hypercholesterolemia in recent years and summary its association with hepatic injury,which can provide theoretical support for further research.