OBJECTIVE To establish a method for simultaneous determination of plasma concentration of lamotrigine（LTG）， levetiracetam（LEV） and perampanel（PER） in children with epilepsy and apply this method in clinical practice. METHODS Plasma proteins were precipitated with acetonitrile. Using PER-D 5 as internal standard， ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） method was adopted. The determination was performed on ACQUITY UPLC HSS T3 C 18 column with mobile phase consisted of 0.1% formic acid with 5 mmol/L ammonium acetate-acetonitrile （gradient elution） at the flow rate of 0.3 mL/min. The column temperature was 40 ℃， and sample size was 5 μL. The analysis time was 5 min. The electrospray ionization source and multiple reaction monitoring mode were used for positive ion scanning. The ion pairs used for quantitative analysis of LTG， LEV， PER and internal standard were m / z 255.9→144.9， m / z 171.1→126.1， m / z 350.1→219.0 and m / z 354.9→220.2， respectively. The steady-state trough concentrations of the aforementioned drugs in the plasma of 14 pediatric epilepsy patients receiving combination therapy were determined using the same UPLC-MS/MS method as above. RESULTS The linear ranges of LTG， LEV and PER were 0.15-24 μg/mL （ R 2 ＞0.993）， 0.312 5-50 μg/mL （ R 2 ＞0.997） and 6.25-1 000 ng/mL （ R 2 ＞0.997）， respectively. The lower limits of quantification were 0.15 μg/mL， 0.312 5 μg/mL and 6.25 ng/mL， respectively. RSDs of intraday and interday precision tests of the three drugs were no more than 9.83%， and the accuracies （relative errors） were between －9.33% and 13.72%（ n ＝6 or n ＝18）； the average extraction recovery rates were 86.4%-97.9%， and the average matrix effects were 86.9%-110.0% （ n ＝6）. The absolute values of the relative errors in the stability tests were all below 15%. The steady-state trough concentrations of LTG， LEV and PER were （5.64±4.03）μg/mL， （10.67±8.78）μg/mL and（450.20±251.27）ng/mL， respectively； the rates of achieving target trough concentrations were 71.4%， 37.5% and 84.6%， respectively. CONCLUSIONS The established UPLC-MS/MS method is specific， rapid and suitable for the plasma concentration monitoring in epileptic children receiving combination therapy.

ObjectiveTo investigate the effects of metformin on the immune functions of immature dendritic cells （imDCs） and the underlying mechanisms. MethodsMouse bone marrow-derived imDCs were treated with different concentrations of metformin. The working concentration and treatment time of metformin in this study were determined based on the results of cell apoptosis and cell viability assays. The effects of metformin on the phagocytic capacity of imDCs was evaluated using an antigen endocytosis assay. The expression of cluster of differentiation 205 （CD205）， the polymerization of filamentous actin （F-actin）， and the underlying regulatory mechanisms were investigated through flow cytometry， laser confocal fluorescence microscopy， and Western blot. ResultsThe working concentrations of metformin were 1， 2， 4 mmol/L for 24 h determined by the apoptosis and cell viability assays.Metformin significantly suppressed the phagocytic capacity of imDCs， down-regulated the expression of the mannose receptor CD205 on the cell surface， which was closely associated with phagocytic function； metformin inhibited the RhoA-ROCK1-LIMK1-Cofilin signaling pathway， which inhibited the polymerization of F-actin and disturbed its dynamic remodeling of imDCs. ConclusionMetformin can inhibit the expression of CD205 and disrupt the remodeling of F-actin， thereby suppressing the antigen-capturing capacity of imDCs.

Background: Adrenocortical hormones, particularly 11-oxygenated androgens, are pivotal in female reproductive health and fertility. Standardized detection kits and population-specific reference intervals are lacking in China, hindering related clinical applications. Methods: A HPLC-tandem mass spectrometry (HPLC-MS/MS) pipeline was developed, rigorously validated, and applied to simultaneously quantify corticosterone, cortisone, cortisol, 18-OH cortisol, androstenedione (A4), 11β-hydroxyandrostenedione (11-OH A4), dehydroepiandrosterone, and dehydroepiandrosterone sulfate in serum samples from 455 reproductive-aged women (18–45 yrs) in Guangxi, China. Age-dependent concentration trends were analyzed, and reference intervals stratified by age (2.5th to 97.5th percentiles) were established. Correlations with body-composition metrics, ethnicity, and the menstrual cycle were investigated. Results: The HPLC-MS/MS method demonstrated high precision (intra- and inter-assay CVs < 15%), accuracy, and sensitivity. All eight hormones exhibited significant age-related declines (P < 0.001 for seven hormones; P = 0.001 for 11-OH A4). Notably, 11-OH A4 levels were significantly lower in the 35–45-yr (3.05 nmol/L) and 25–34-yr (3.09 nmol/L) age groups than in the 18–24-yr (3.57 nmol/L) age group, whereas no significant difference was observed between the 35–45-yr and 25–34-yr age groups. Weak negative correlations were observed between the body mass index and corticosterone and cortisone levels, whereas ethnicity and the menstrual cycle showed no significant associations with hormone levels. Conclusions We developed an HPLC-MS/MS-based method for simultaneously quantifying eight adrenocortical hormones, including 11-OH A4, and defined age-specific reference intervals for reproductive-aged Chinese women. These findings advance the clinical utility of adrenocortical hormones in diagnosing and managing reproductive disorders.

ObjectiveTo investigate the association between noninvasive liver fibrosis markers and carotid plaque （CP） in patients with lean metabolic dysfunction-associated fatty liver disease （MAFLD）， and to provide a basis for screening high-risk populations. MethodsA total of 957 patients with lean MAFLD who underwent physical examination in Subei People’s Hospital from January 2021 to June 2023 was enrolled as the observation cohort， with the presence or absence of CP as the outcome， and fibrosis-4 （FIB-4） index and nonalcoholic fatty liver disease fibrosis score （NFS） were used to assess liver fibrosis degree. The independent-samples t test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； the chi-square test was used for comparison of categorical data between two groups. The multivariate logistic regression analysis， the restricted cubic spline analysis， the receiver operating characteristic curve， and the mediation effect analysis were used to investigate the association between liver fibrosis degree and CP. ResultsThe prevalence rate of CP was 36.6% in the lean MAFLD population. Compared with the non-CP group（n=607）， the CP group （n=350） had a significantly higher proportion of male patients， a significantly higher proportion of patients with smoking/diabetes/hypertension， and significantly higher levels of age， creatinine， blood urea nitrogen， triglycerides， fasting blood glucose， aspartate aminotransferase， aspartate aminotransferase/alanine aminotransferase ratio， NFS， and FIB-4 index， as well as significantly lower levels of platelet count and albumin （all P<0.05）. The multivariate logistic regression analysis showed that after adjustment for confounding factors， FIB-4 index （odds ratio［OR］=2.979， 95% confidence interval［CI］：2.141 — 4.219， P<0.001） and NFS （OR=1.747， 95%CI： 1.499 — 2.046， P<0.001） were positively correlated with CP. Both FIB-4 index and NFS had a good value in predicting CP. Hypertension had a significant indirect effect on the prevalence rate of CP through its impact on liver fibrosis markers， and its mediating effect accounted for 39.5% — 40.8% of the total effect （P<0.001）. ConclusionIn patients with lean MAFLD， NFS and FIB-4 index are significantly positively correlated with the prevalence rate of CP， and they can be used as potential epidemiological predictive indicators. Liver fibrosis markers may play a mediating role in the association between hypertension and CP. Interventions targeting hypertension and liver fibrosis markers may help to prevent and delay the progression of CP.

The construction of a training system for visiting physicians in the department of rare diseases in China is an important measure to improve the overall diagnosis and treatment capacity for rare diseases and address the critical challenge of insufficient knowledge and skills among clinicians in practice. This article systematically describes the visiting physician training system established by the Department of Rare Diseases at Peking Union Medical College Hospital. It summarizes the training objectives and positioning, design logic, and learning modules of the system, aiming to provide a reference for the construction of the specialized talent team for rare diseases in China.

Gorham-Stout disease(GSD) is a rare osteolytic disorder characterized by spontaneous and progressive osteolysis, along with abnormal angiogenesis and lymphangiogenesis, with no new bone formation. We present a case of a 15-year-old female admitted due to " recurrent right leg pain for 5 years, 11 months after undergoing right femoral fracture surgery". Through comprehensive integration of the patient's clinical phenotype, laboratory tests, imaging findings, pathological examinations, and molecular biological test results, GSD was considered highly likely. A multidisciplinary treatment approach was conducted, including a combination of zoledronic acid and sirolimus to inhibit osteolysis, along with rehabilitation training and orthopedic intervention, providing a personalized and comprehensive treatment strategy.

Rheumatoid arthritis （RA） is a common autoimmune disease characterised clinically by symmetrical joint pain， swelling， and stiffness. Long-term chronic synovial inflammation can lead to severe joint damage and even disability， thereby affecting quality of life for patients. Current clinical treatment of RA emphasises an integrated approach combining traditional Chinese and Western medicine， with traditional Chinese medicine offering certain advantages in reducing disease activity of RA， preventing relapses， and other aspects. Modern clinical evidence confirms that Guizhi Shaoyao Zhimutang （GSZT） is effective in improving symptoms such as immune metabolism， joint stiffness， and joint pain in RA patients. Pharmacological studies have revealed that GSZT primarily contains components such as cinnamaldehyde， total glucosides of paeony， total alkaloids of Aconiti Lateralis Radix Praeparata， glycyrrhetinic acid， zingiberone， isoimperatorin， ephedra polysaccharides， and cedrol. It improves RA symptoms via multiple mechanisms and targets， including enhancing immune responses， exerting anti-inflammatory and analgesic effects， regulating relevant signalling pathways， inhibiting cell apoptosis， and suppressing bone destruction. This paper reviewed the syndrome patterns and pharmacological basis of GSZT in the treatment of RA， as well as its clinical applications and related mechanisms， thereby providing a theoretical basis and reference for the further development and utilisation of GSZT in the treatment of RA.

Rheumatoid arthritis （RA） is a common autoimmune disease characterised clinically by symmetrical joint pain， swelling， and stiffness. Long-term chronic synovial inflammation can lead to severe joint damage and even disability， thereby affecting quality of life for patients. Current clinical treatment of RA emphasises an integrated approach combining traditional Chinese and Western medicine， with traditional Chinese medicine offering certain advantages in reducing disease activity of RA， preventing relapses， and other aspects. Modern clinical evidence confirms that Guizhi Shaoyao Zhimutang （GSZT） is effective in improving symptoms such as immune metabolism， joint stiffness， and joint pain in RA patients. Pharmacological studies have revealed that GSZT primarily contains components such as cinnamaldehyde， total glucosides of paeony， total alkaloids of Aconiti Lateralis Radix Praeparata， glycyrrhetinic acid， zingiberone， isoimperatorin， ephedra polysaccharides， and cedrol. It improves RA symptoms via multiple mechanisms and targets， including enhancing immune responses， exerting anti-inflammatory and analgesic effects， regulating relevant signalling pathways， inhibiting cell apoptosis， and suppressing bone destruction. This paper reviewed the syndrome patterns and pharmacological basis of GSZT in the treatment of RA， as well as its clinical applications and related mechanisms， thereby providing a theoretical basis and reference for the further development and utilisation of GSZT in the treatment of RA.

National biological standards for antibiotics are critical components of the antibiotic quality control system and serve as reference materials for measuring and calibrating the biological activity of antibiotics. This article systematically reviews the classification, definition of potency units, and current research status of commercially available national antibiotic biological standards in China. At present, these standards can be categorized based on chemical structure, number of components, and development methods. The definition of potency units has evolved from an early “arbitrarily assigned unit” to “being represented by the mass of the antibiotic salt” and, more recently, to the current mainstream approach of “being represented by the mass of the active ingredient”. This evolution reflects a shift in quality control philosophy from primarily biological analysis to a system dominated by chemical analysis supplemented by biological methods. Current research focuses on optimizing potency determination methods, studying the unification of content and potency, and implementing dual quality control of both the potency and the ratio/content of active components in multi-component antibiotics. For complex multi-component antibiotics, the microbiological assay based on biological activity remains irreplaceable in quality control. Future efforts should emphasize further method optimization, ensuring batch-to-batch consistency of standards, and advancing precision quality control as key research priorities for antibiotic biological standards.

Osteoarthritis (OA), a highly prevalent degenerative joint disease worldwide, is defined by articular cartilage degradation, abnormal bone remodeling, and persistent chronic inflammation. It severely compromises patients’ quality of life, and currently, there is no radical cure. Abnormal mechanical stress is widely regarded as a core driver of OA pathogenesis, and the exploration of mechanical signal perception and transduction mechanisms has become crucial for deciphering OA’s pathophysiological processes. Piezo1, a key mechanosensitive cation channel belonging to the Piezo protein family, has recently gained significant attention due to its pivotal role in mediating cellular responses to mechanical stimuli in joint tissues. This review systematically examines Piezo1’s expression patterns, regulatory mechanisms, and pathological functions in OA, with a particular focus on its dual roles in modulating chondrocyte homeostasis and bone metabolism disorders, while also delving into the underlying molecular signaling pathways and potential therapeutic implications. Piezo1, consisting of approximately 2 500 amino acids and forming a unique trimeric propeller-like structure, is widely expressed in chondrocytes, osteocytes, mesenchymal stem cells, and synovial cells. It exhibits permeability to cations such as Ca²⁺, K⁺, and Na⁺, and directly responds to membrane tension changes induced by mechanical stimuli like fluid shear stress and mechanical overload. In OA patients and animal models, Piezo1 expression is significantly upregulated, especially in cartilage regions subjected to abnormal mechanical stress (e.g., human temporomandibular joint cartilage). This overexpression is closely associated with aggravated cartilage degeneration, increased chondrocyte apoptosis, accelerated cellular senescence, and intensified inflammatory responses. Mechanical overload and pro-inflammatory cytokines (e.g., IL-1β) are key inducers of Piezo1 upregulation: IL-1β activates the PI3K/AKT/mTOR signaling pathway to enhance Piezo1 expression, forming a pathogenic positive feedback loop that inhibits chondrocyte autophagy, promotes apoptosis, and further accelerates joint degeneration. Mechanistically, Piezo1 mediates OA progression through multiple interconnected pathways. When activated by mechanical stress, Piezo1 triggers excessive Ca²⁺ influx, leading to endoplasmic reticulum stress (ERS) and mitochondrial dysfunction, which directly induce chondrocyte apoptosis. This process involves the activation of downstream signaling cascades such as cGAS-STING and YAP-MMP13/ADAMTS5. YAP, a transcriptional regulator, upregulates the expression of matrix metalloproteinase 13 (MMP13) and aggrecanase (ADAMTS5), thereby accelerating cartilage matrix degradation. Additionally, Piezo1-driven Ca²⁺ overload promotes the accumulation of reactive oxygen species (ROS) and upregulates senescence markers (p16 and p21), accelerating chondrocyte senescence via the p38MAPK and NF-κB pathways. Senescent chondrocytes secrete senescence-associated secretory phenotype (SASP) factors (e.g., IL-6, IL-1β), further amplifying joint inflammation. In terms of bone metabolism, Piezo1 maintains joint homeostasis by promoting the differentiation of fibrocartilage stem cells into chondrocytes and balancing bone formation and resorption through regulating the FoxC1/YAP axis and RANKL/OPG ratio. Therapeutically, targeting Piezo1 shows promising potential. Preclinical studies have demonstrated that Piezo1 inhibitors (e.g., GsMTx4) can reduce joint damage and alleviate pain in OA mice. Simultaneously, siRNA-mediated co-silencing of Piezo1 and TRPV4 (another mechanosensitive channel) decreases intracellular Ca²⁺ concentration, inhibits chondrocyte apoptosis, and promotes cartilage repair. Conditional knockout of Piezo1 using Gdf5-Cre transgenic mice alleviates cartilage degeneration in post-traumatic OA models by downregulating MMP13 and ADAMTS5 expression. Despite existing challenges, such as off-target effects of inhibitors, inefficient local drug delivery, and interindividual genetic variability, strategies like developing selective Piezo1 antagonists, optimizing targeted nanocarriers, and combining Piezo1-targeted therapy with physical therapy provide viable avenues for clinical translation. The authors propose that Piezo1 serves as a critical therapeutic target for OA, and future research should focus on deciphering its context-dependent regulatory networks, developing tissue-specific intervention strategies, and validating their efficacy and safety in clinical trials to address the unmet medical needs of OA patients.