BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

ObjectiveTo investigate the influence of histone deacetylase 3 (HDAC3) on the occurrence, development of psoriasis-like inflammation in mice, and the relative immune mechanisms. MethodsHealthy C57BL/6 mice aged 6-8 weeks were selected and randomly divided into 3 groups: control group (Control), psoriasis model group (IMQ), and HDAC3 inhibitor RGFP966-treated psoriasis model group (IMQ+RGFP966). One day prior to the experiment, the back hair of the mice was shaved. After a one-day stabilization period, the mice in Control group was treated with an equal amount of vaseline, while the mice in IMQ group was treated with imiquimod (62.5 mg/d) applied topically on the back to establish a psoriasis-like inflammation model. The mice in IMQ+RGFP966 group received intervention with a high dose of the HDAC3-selective inhibitor RGFP966 (30 mg/kg) based on the psoriasis-like model. All groups were treated continuously for 5 d, during which psoriasis-like inflammation symptoms (scaling, erythema, skin thickness), body weight, and mental status were observed and recorded, with photographs taken for documentation. After euthanasia, hematoxylin-eosin (HE) staining was used to assess the effect of RGFP966 on the skin tissue structure of the mice, and skin thickness was measured. The mRNA and protein expression levels of HDAC3 in skin tissues were detected using reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB), respectively. Flow cytometry was employed to analyze neutrophils in peripheral blood and lymph nodes, CD4⁺ T lymphocytes, CD8⁺ T lymphocytes in peripheral blood, and IL-17A secretion by peripheral blood CD4⁺ T lymphocytes. Additionally, spleen CD4⁺ T lymphocyte expression of HDAC3, CCR6, CCR8, and IL-17A secretion levels were analyzed. Immunohistochemistry was used to detect the localization and expression levels of HDAC3, IL-17A, and IL-10 in skin tissues. ResultsCompared with the Control group, the IMQ group exhibited significant psoriasis-like inflammation, characterized by erythema, scaling, and skin wrinkling. Compared with the IMQ group, RGFP966 exacerbated psoriasis-like inflammatory symptoms, leading to increased hyperkeratosis. The psoriasis area and severity index (PASI) skin symptom scores were higher in the IMQ group than those in the Control group, and the scores were further elevated in the IMQ+RGFP966 group compared to the IMQ group. Skin thickness measurements showed a trend of IMQ+RGFP966>IMQ>Control. The numbers of neutrophils in the blood and lymph nodes increased sequentially in the Control, IMQ, and IMQ+RGFP966 groups, with a similar trend observed for CD4⁺ and CD8⁺ T lymphocytes in the blood. In skin tissues, compared with the Control group, the mRNA and protein levels of HDAC3 decreased in the IMQ group, but RGFP966 did not further reduce these expressions. HDAC3 was primarily located in the nucleus. Compared with the Control group, the nuclear HDAC3 content decreased in the skin tissues of the IMQ group, and RGFP966 further reduced nuclear HDAC3. Compared with the Control and IMQ groups, RGFP966 treatment decreased HDAC3 expression in splenic CD4⁺ and CD8⁺ T cells. RGFP966 treatment increased the expression of CCR6 and CCR8 in splenic CD4⁺ T cells and enhanced IL-17A secretion by peripheral blood and splenic CD4⁺ T lymphocytes. Additionally, compared with the IMQ group, RGFP966 reduced IL-10 protein levels and upregulated IL-17A expression in skin tissues. ConclusionRGFP966 exacerbates psoriatic-like inflammatory responses by inhibiting HDAC3, increasing the secretion of the cytokine IL-17A, and upregulating the expression of chemokines CCR8 and CCR6.

Objective To evaluate the role of distortion product otoacoustic emissions (DPOAE) testing in evaluating early hearing loss among noise-exposed workers. Methods A total of 174 noise-exposed workers in a metal shipbuilding enterprise were selected as the research subjects by the convenience sampling method. Pure tone audiometry (PTA), DPOAE and the level of noise exposure were conducted on the workers. The rank correlation analysis was used to analyze the correlation between DPOAE amplitude and PTA threshold. The multilevel model was used to analyze the effects of gender, age, noise exposure intensity, cumulative noise exposure (CNE), hearing loss classification and PTA threshold on DPOAE results. Results At the frequencies of 0.50, 1.00, 2.00, 3.00, 4.00, 6.00 and 8.00 kHz, the DPOAE amplitude was negatively correlated with the PTA threshold (rank correlation coefficients were -0.12, -0.48, -0.47, -0.18, -0.23, -0.44, -0.19, respectively, all P<0.01). At the most frequencies, DPOAE amplitude was negatively correlated with age and CNE (all P<0.05). The results of multilevel model analysis showed that there were significant differences in DPOAE amplitudes at certain frequencies across gender, age, noise intensity, CNE, and hearing loss classification (all P<0.05). Significant differences in DPOAE responses were found among different CNE and hearing loss groups (all P<0.01). Conclusion DPOAE testing can objectively reflect the hearing status of noise-exposed workers and could be considered for inclusion in routine hearing monitoring to facilitate early detection of noise-induced hearing loss.

[摘 要] 目的：构建程序性死亡受体1（PD-1）高表达的细菌质膜纳米囊泡（BMV）BMV-PD-1，评估其对小鼠肺癌移植瘤组织的靶向性。方法：通过质粒转化将PD-1与膜孔蛋白细胞溶素A（ClyA）融合质粒ClyA-PD-1-EGFP转入大肠杆菌BL21-Codonplus，使用激光共聚焦显微镜、SDS-PAGE和WB法检测融合蛋白ClyA-PD-1-EGFP的表达。提取质膜并采用挤出法，利用挤出器制备BMV-PD-1。采用透射电子显微镜（TEM）、纳米粒子跟踪分析（NTA）技术分别对BMV-PD-1的形态、粒径和膜电位进行检测，用WB鉴定PD-1蛋白的携带情况。采用激光共聚焦成像检测Lewis肺癌LLC细胞对BMV-PD-1的摄取。建立肺癌LLC细胞C57BL/6J小鼠皮下移植瘤模型，采用小动物活体成像系统评估BMV-PD-1的肿瘤靶向性。结果：激光共聚焦显微成像结果显示，质粒ClyA-PD-1-EGFP被转入BL21-Codonplus并成功表达蛋白。SDS-PAGE结果表明，ClyA-PD-1-EGFP在BL21-Codonplus中过表达。WB分析表明，PD-1在细菌中表达且在BMV-PD-1上呈高表达（P < 0.001）状态。NTA和TEM分析表明，BMV-PD-1是一种粒径为（145 ± 14） nm、表面呈负电性的球状囊泡。激光共聚焦成像显示，PD-1高表达能显著提升肺癌细胞对BMV-PD-1的摄取（P < 0.01），小动物活体成像也进一步证实PD-1高表达能有效提升BMV-PD-1的肿瘤靶向性（P < 0.01）。结论：本研究成功构建了PD-1高表达的细菌纳米囊泡BMV-PD-1，发现PD-1高表达可显著提高BMV-PD-1的肺癌LLC细胞移植瘤组织的靶向性，为进一步开发以BMV-PD-1为载体的肿瘤靶向药物递送系统奠定基础。

Objective: To analyze the latent tuberculosis infection and preventive treatment in the school tuberculosis epidemic, so as to provide theoretical and technical support for tuberculosis prevention and control in schools. Methods: Information on latent infection, preventive treatment and tuberculosis incidence were collected from five tuberculosis outbreaks in schools in Hunan Province from January to December 2023. Statistical analysis was conducted by using Chisquare test and Fishers exact test. Results: The prevalence of tuberculosis patients in close contacts (7.69%) and the latent infection rate of Mycobacterium tuberculosis (31.87%) were higher than those in nonclose contacts (0.12%, 6.29%), and the differences were statistically significant (P＜0.01). The subsequent incidence of close contacts with latent infection was higher (8.62%) than that of nonclose contacts (0), the rate of close contacts receiving prophylactic treatment (63.30%) was higher than that of nonclose contacts (47.37%), and the proportion of close contacts receiving prophylactic treatment (68.12%) was higher than that of nonclose contacts (45.56%), and the differences were statistically significant (P＜0.05). The latent infection rate of Mycobacterium tuberculosis in college students (13.58%) was higher than that in middle school students (7.08%) (χ2=37.77, P<0.01). The proportion of college students receiving preventive treatment (100.00%) was higher than that of middle school students (40.34%), and the subsequent incidence of latent infection (6.67%) was higher than that of middle school students (0.54%); the rate of middle school students who should receive preventive treatment (70.41%) was higher than that of college students (30.77%), and the rate of middle school students who received preventive treatment (100.00%) was higher than that of college students (62.50%), and the differences were statistically significant (P<0.01). Among the latent infected persons, 144 who completed preventive treatment did not get sick, and 10 of the 177 who did not complete preventive treatment got sick, with an incidence rate of 5.65%. The incidence rate of close contacts (19.23%) was higher than that of nonclose contacts (0) (P<0.01). There was no significant difference in the incidence of pulmonary tuberculosis between university (8.18%) and middle school (1.49%) among latent infected persons who did not complete preventive treatment (P=0.09). Conclusion Actively promoting preventive treatment for latent infections, especially among close contacts, and ensuring that all eligible individuals receive treatment can reduce tuberculosis incidence in schools and help control the scale of school tuberculosis outbreaks.

ObjectiveNon-invasive magnetic stimulation technology has been widely used in the treatment of Alzheimer’s disease (AD), but there is a lack of convenient and timely methods for evaluating and providing feedback on the effectiveness of the stimulation, which can be used to guide the adjustment of the stimulation protocol. This study aims to explore the possibility of heart rate variability (HRV) in diagnosing AD and guiding AD magnetic stimulation intervention techniques. MethodsIn this study, we used a 40 Hz, 10 mT pulsed magnetic field to expose AD mouse models to whole-body exposure for 18 d, and detected the behavioral and electroencephalographic signals before and after exposure, as well as the instant electrocardiographic signals after exposure every day. ResultsUsing one-way ANOVA and Pearson correlation coefficient analysis, we found that some HRV indicators could identify AD mouse models as accurately as behavioral and electroencephalogram(EEG) changes (P<0.05) and significantly distinguish the severity of the disease (P<0.05), including rMSSD, pNN6, LF/HF, SD1/SD2, and entropy arrangement. These HRV indicators showed good correlation and statistical significance with behavioral and EEG changes (r>0.3, P<0.05); HRV indicators were significantly modulated by the magnetic field exposure before and after the exposure, both of which were observed in the continuous changes of electrocardiogram (ECG) (P<0.05), and the trend of the stimulation effect was more accurately observed in the continuous changes of ECG. ConclusionHRV can accurately reflect the pathophysiological changes and disease degree, quickly evaluate the effect of magnetic stimulation, and has the potential to guide the pattern of magnetic exposure, providing a new idea for the study of personalized electromagnetic neuroregulation technology for brain diseases.

ObjectiveTo investigate the chemical constituents of Chuanxiong Rhizoma-Paeoniae Radix Rubra（CRPRR） that cross the blood-brain barrier in rats with ischemic stroke， their brain-protective effects， and their impact on inflammatory factors including tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-18 （IL-18） based on ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF-MS） and pharmacodynamic experiments. MethodsA focal cerebral ischemia-reperfusion injury model was established in rats via the middle cerebral artery occlusion/reperfusion （MCAO/R） method using intraluminal suture. Neurological function was evaluated using behavioral scoring. UPLC-Q-TOF-MS was employed to identify the chemical constituents of CRPRR that crossed the blood-brain barrier and entered the cerebrospinal fluid in MCAO/R model rats. Male Sprague-Dawley rats were randomly divided into six groups： sham operation group， model group， low-， medium-， and high-dose CRPRR groups （1.35， 2.7， 5.4 g·kg^-1， respectively）， and an edaravone group （5 mg·kg^-1）， with 12 rats in each group. The sham and model groups received normal saline， while the treatment groups received the respective doses of CRPRR once daily by gavage for three consecutive weeks. The brain-protective effects of CRPRR were assessed using the Longa five-point scoring method， open field test， Morris water maze， 2，3，5-triphenyltetrazolium chloride （TTC） staining， hematoxylin and eosin （HE） staining， and transmission electron microscopy. ResultsNine chemical constituents were identified in the cerebrospinal fluid containing CRPRR， namely paeoniflorin， senkyunolide F， senkyunolide G， paeonimetabolin Ⅰ， paeoniflorin derivative， senkyunolide H， benzoylpaeoniflorin， senkyunolide A， and ligustilide. Animal experiment results showed that compared with the sham operation group， the model group exhibited disordered neuronal arrangement， severe vacuolation， nuclear pyknosis， and evident mitochondrial swelling. Chromatin aggregation and peripheralization were also observed. Neurological scores and the number of crossings in the central region were significantly increased （P<0.01）， while platform crossings were significantly decreased （P<0.01）， and clear infarct areas were present （P<0.01）. Serum levels and protein expression of TNF-α， IL-1β， and IL-18 were significantly elevated （P<0.01）. Compared with the model group， all dose groups of CRPRR showed marked improvement in neuronal morphology which was close to the normal level， with mitochondrial swelling alleviated and chromatin distribution more uniform. The medium- and high-dose groups significantly reduced neurological scores （P<0.01）， while the low-， medium-， and high-dose groups significantly reduced the number of central crossings （P<0.01） and infarct volume （P<0.01）， and decreased TNF-α， IL-1β， and IL-18 levels （P<0.05， P<0.01） compared with the model group. Furthermore， the medium- and high-dose groups significantly reduced TNF-α protein expression （P<0.05，P<0.01）， and the high-dose group significantly reduced IL-1β and IL-18 protein expression （P<0.01）. ConclusionThis study confirmed that CRPRR improves neurological function and alleviates brain tissue damage in MCAO/R rats. Its mechanism may be associated with the downregulation of inflammatory factors TNF-α， IL-1β， and IL-18， as well as the presence of nine active chemical constituents in cerebrospinal fluid， namely paeoniflorin， senkyunolide F， senkyunolide G， paeonimetabolin Ⅰ， paeoniflorin derivative， senkyunolide H， benzoylpaeoniflorin， senkyunolide A， and ligustilide， which are closely related to their brain-protective effects.

ObjectiveTo investigate the chemical constituents of Chuanxiong Rhizoma-Paeoniae Radix Rubra（CRPRR） that cross the blood-brain barrier in rats with ischemic stroke， their brain-protective effects， and their impact on inflammatory factors including tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-18 （IL-18） based on ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF-MS） and pharmacodynamic experiments. MethodsA focal cerebral ischemia-reperfusion injury model was established in rats via the middle cerebral artery occlusion/reperfusion （MCAO/R） method using intraluminal suture. Neurological function was evaluated using behavioral scoring. UPLC-Q-TOF-MS was employed to identify the chemical constituents of CRPRR that crossed the blood-brain barrier and entered the cerebrospinal fluid in MCAO/R model rats. Male Sprague-Dawley rats were randomly divided into six groups： sham operation group， model group， low-， medium-， and high-dose CRPRR groups （1.35， 2.7， 5.4 g·kg^-1， respectively）， and an edaravone group （5 mg·kg^-1）， with 12 rats in each group. The sham and model groups received normal saline， while the treatment groups received the respective doses of CRPRR once daily by gavage for three consecutive weeks. The brain-protective effects of CRPRR were assessed using the Longa five-point scoring method， open field test， Morris water maze， 2，3，5-triphenyltetrazolium chloride （TTC） staining， hematoxylin and eosin （HE） staining， and transmission electron microscopy. ResultsNine chemical constituents were identified in the cerebrospinal fluid containing CRPRR， namely paeoniflorin， senkyunolide F， senkyunolide G， paeonimetabolin Ⅰ， paeoniflorin derivative， senkyunolide H， benzoylpaeoniflorin， senkyunolide A， and ligustilide. Animal experiment results showed that compared with the sham operation group， the model group exhibited disordered neuronal arrangement， severe vacuolation， nuclear pyknosis， and evident mitochondrial swelling. Chromatin aggregation and peripheralization were also observed. Neurological scores and the number of crossings in the central region were significantly increased （P<0.01）， while platform crossings were significantly decreased （P<0.01）， and clear infarct areas were present （P<0.01）. Serum levels and protein expression of TNF-α， IL-1β， and IL-18 were significantly elevated （P<0.01）. Compared with the model group， all dose groups of CRPRR showed marked improvement in neuronal morphology which was close to the normal level， with mitochondrial swelling alleviated and chromatin distribution more uniform. The medium- and high-dose groups significantly reduced neurological scores （P<0.01）， while the low-， medium-， and high-dose groups significantly reduced the number of central crossings （P<0.01） and infarct volume （P<0.01）， and decreased TNF-α， IL-1β， and IL-18 levels （P<0.05， P<0.01） compared with the model group. Furthermore， the medium- and high-dose groups significantly reduced TNF-α protein expression （P<0.05，P<0.01）， and the high-dose group significantly reduced IL-1β and IL-18 protein expression （P<0.01）. ConclusionThis study confirmed that CRPRR improves neurological function and alleviates brain tissue damage in MCAO/R rats. Its mechanism may be associated with the downregulation of inflammatory factors TNF-α， IL-1β， and IL-18， as well as the presence of nine active chemical constituents in cerebrospinal fluid， namely paeoniflorin， senkyunolide F， senkyunolide G， paeonimetabolin Ⅰ， paeoniflorin derivative， senkyunolide H， benzoylpaeoniflorin， senkyunolide A， and ligustilide， which are closely related to their brain-protective effects.

To investigate the prevalence and associated factors of fall risk among Chinese older adults, and to examine the roles of urban-rural differences, regional disparities, physical health status, and psychosocial factors in falls among this population, thereby providing evidence for tailored fall prevention strategies.

Objective: To establish a database of CD36 antigen-negative donors through large-scale screening of apheresis platelet donors in Shenzhen for CD36 deficiency subtypes and blood group distribution, and to assess clinical demand and blood supply capacity through a retrospective analysis of the apheresis platelet donation volumes from 2019 to 2023. Methods: Flow cytometry with fluorescent CD36 monoclonal antibodies was employed to screen platelet/monocyte CD36 deficiency (Type I and Ⅱ), and statistical analyses were conducted using SPSS software (version 27.0). Results: Among 11 603 apheresis platelet donors, 248 (2.14%) exhibited CD36 deficiency, comprising 51 type Ⅰ (0.43%, 51/11, 603) and 197 type Ⅱ (1.70%, 197/11, 603) cases, with significant difference (P<0.001). CD36 deficient platelets were mainly distributed in blood group B (2.28%, 902.3/39 602.1) and AB (2.14, 269/12 544.5), significantly exceeding those in blood group A (1.43%, 667/46 508.4) and O (1.64%, 1 000/60 965.6) (P<0.001). The proportion of donors with 10-100 U from CD36 deficient donors was the highest (51%, 1 446.4/2 838.3). Conclusion: Sustained screening for CD36-deficient donors is recommended to meet the clinical transfusion needs for immunized patients and those requiring antigen-negative products. Regional resource-sharing mechanisms should be optimized to maximize utilization of CD36-deficient platelet inventories.