BACKGROUND:Previous studies of the research group have found that icariin-containing serum can delay the progression of knee osteoarthritis,promote chondrocyte proliferation and stem cell cartilage differentiation in rats,but there is still a lack of sufficient basis for clinical application.OBJECTIVE:To investigate the repair effect of icariin-containing serum on lipopolysaccharide-induced inflammatory damage of human chondrocytes.METHODS:The effect of icariin-containing serum on chondrocyte viability was detected by cell counting kit-8 method,and the optimal volume fraction and time of icariin-containing serum were screened.The cells were then divided into blank group,lipopolysaccharide group,icariin-containing serum group and lipopolysaccharide+icariin-containing serum group.After grouping,immunofluorescence was used to detect the secretion of type Ⅱ collagen in chondrocytes in each group.Real-time PCR was used to detect the expression of related genes.RESULTS AND CONCLUSION:(1)Icariin-containing serum showed good biosafety characteristics for human chondrocytes,and the cell viability reached the highest level after 48 hours of intervention when the icariin-containing serum volume fraction was 15％,and the follow-up experiments were carried out according to the conditions.(2)Compared with the blank group,lipopolysaccharide significantly inhibited the expression of type Ⅱ collagen in chondrocytes,while icariin-containing serum showed a positive mobilization effect,which could effectively promote the secretion of type Ⅱ collagen in chondrocytes under normal and inflammatory conditions.(3)The mRNA expression of type Ⅱ collagen and Aggrecan in chondrocytes decreased significantly under lipopolysaccharide stimulation,and the mRNA expression levels of matrix metalloproteinase 13 and a disintegrin-like and metalloproteinase with thrombospondin motifs-5 increased significantly.Icariin-containing serum promoted the mRNA expression of type Ⅱ collagen in human chondrocytes under inflammatory conditions and reduced the mRNA expression of matrix metalloproteinase 13 and a disintegrin-like and metalloproteinase with thrombospondin motifs-5 in chondrocytes after lipopolysaccharide intervention.Therefore,these findings indicate that the icariin-containing serum has good safety for human chondrocytes and plays an important role in maintaining the normal physiological functions of chondrocytes,promoting the synthesis of extracellular matrix,and inhibiting the secretion of inflammatory factors.

BACKGROUND:Previous studies of the research group have found that icariin-containing serum can delay the progression of knee osteoarthritis,promote chondrocyte proliferation and stem cell cartilage differentiation in rats,but there is still a lack of sufficient basis for clinical application.OBJECTIVE:To investigate the repair effect of icariin-containing serum on lipopolysaccharide-induced inflammatory damage of human chondrocytes.METHODS:The effect of icariin-containing serum on chondrocyte viability was detected by cell counting kit-8 method,and the optimal volume fraction and time of icariin-containing serum were screened.The cells were then divided into blank group,lipopolysaccharide group,icariin-containing serum group and lipopolysaccharide+icariin-containing serum group.After grouping,immunofluorescence was used to detect the secretion of type Ⅱ collagen in chondrocytes in each group.Real-time PCR was used to detect the expression of related genes.RESULTS AND CONCLUSION:(1)Icariin-containing serum showed good biosafety characteristics for human chondrocytes,and the cell viability reached the highest level after 48 hours of intervention when the icariin-containing serum volume fraction was 15％,and the follow-up experiments were carried out according to the conditions.(2)Compared with the blank group,lipopolysaccharide significantly inhibited the expression of type Ⅱ collagen in chondrocytes,while icariin-containing serum showed a positive mobilization effect,which could effectively promote the secretion of type Ⅱ collagen in chondrocytes under normal and inflammatory conditions.(3)The mRNA expression of type Ⅱ collagen and Aggrecan in chondrocytes decreased significantly under lipopolysaccharide stimulation,and the mRNA expression levels of matrix metalloproteinase 13 and a disintegrin-like and metalloproteinase with thrombospondin motifs-5 increased significantly.Icariin-containing serum promoted the mRNA expression of type Ⅱ collagen in human chondrocytes under inflammatory conditions and reduced the mRNA expression of matrix metalloproteinase 13 and a disintegrin-like and metalloproteinase with thrombospondin motifs-5 in chondrocytes after lipopolysaccharide intervention.Therefore,these findings indicate that the icariin-containing serum has good safety for human chondrocytes and plays an important role in maintaining the normal physiological functions of chondrocytes,promoting the synthesis of extracellular matrix,and inhibiting the secretion of inflammatory factors.

Objective: To investigate the regional differences in the incidence of urothelial carcinoma among kidney transplant recipients between northern and southern China，so as to provide reference for early diagnosis of this disease. Methods: A comprehensive search was conducted across multiple databases，including CNKI，Wanfang，CBM，and PubMed，using the keywords “kidney transplantation” and “tumor” to collect clinical data from qualified kidney transplant centers.The latest and most complete literature data published by 17 transplant centers in northern China and 14 in southern China were included.Statistical analyses were performed to compare the incidence of post-transplant urothelial carcinoma and non-urothelial malignancies. Results: A total of 37 475 kidney transplant recipients were included，among whom 837 (2.23%) developed post-transplant malignancies，including urothelial carcinoma (366/837，43.73%)，non-urothelial carcinoma (444/837，53.05%)，and malignancies with unspecified pathology (27/837，3.23%).The incidence of malignancies was significantly higher in northern China than in southern China [(2.82±1.39)% vs. (1.67±0.83)%，P=0.011]，with a particularly pronounced difference in the incidence of urothelial carcinoma [(1.68±1.12)% vs. (0.32±0.32)%，P<0.001].No significant difference was observed in the incidence of non-urothelial carcinoma between the two regions [(1.11±0.56)% vs. (1.35±0.65)%，P=0.279].Additionally，female transplant recipients exhibited a higher incidence of malignancies than males in both regions (southern China：2.38% vs. 1.80%; northern China：8.93% vs. 2.52%). Conclusion: The incidence of urothelial carcinoma following kidney transplantation is significantly higher in northern China than in southern China，underscoring the importance of implementing regular tumor screening for kidney transplant recipients，particularly for female patients in northern China，to facilitate early diagnosis and timely intervention.

Infertility is a common reproductive disorder affecting millions of couples worldwide. It is estimated that male factors account for about 30%-50% of infertility cases, and some studies have found that the concentration of male sperm gradually decreases over time, a trend that suggests the importance of male fertility. Many factors contribute to the decline of male fertility, among which environmental factors have received widespread attention. After reaching adulthood, spermatogonial stem cells will continue to produce sperm, but these cells exist outside the blood testicular barrier, which makes them highly sensitive to environmental conditions such as air pollution, tobacco smoke, radiation, and heavy metals. It is reported that exposure to these adverse environmental factors not only causes oxidative stress and DNA damage to germ cells, but also leads to abnormal epigenetic modification of sperm DNA, thereby causing a series of diseases. This article reviewed the abnormal methylation changes in DNA associated with exposure to environmental pollutants during spermatogenesis and how these changes affect the quantity, quality, and function of spermatozoa.

Alcohol exposure, as a widespread environmental factor, is highly toxic and teratogenic. Embryonic stem cells (ESCs) are pluripotent and key to development, and their gene expression is tightly regulated, allowing the cells to differentiate without self-renewal. Numerous studies showed that alcohol is an important factor affecting the differentiation of ESCs. In this paper, we systematically summarized four major molecular mechanisms underlying alcohol associated differentiation of ESCs: (1) inhibition of the Wnt signaling pathway; (2) restriction of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway; (3) alteration of the expression of pluripotent transcription factors; and (4) activation of the nuclear transcriptional program. Through the above mechanisms, alcohol induces aberrant expression of differentiation-related genes and alters the direction of cellular differentiation towards specific lineages, thereby affecting normal embryonic development. Based on the studies on ESCs modeling and other in vitro and in vivo differentiation experiments, the molecular basis of how alcohol affects differentiation by interfering with signaling networks and transcriptional regulation was elucidated, and the results of current research in this field were also summarized, which is crucial for understanding alcohol-mediated toxic effects.

Objective:To investigate the acute effects of persistent high exposure to atmospheric fine particulate matter (PM 2.5) on residents' outpatient visits for respiratory diseases. Methods:We collected daily outpatient records from 92 hospitals in 13 cities across the Beijing-Tianjin-Hebei region, along with daily PM 2.5, nitrogen dioxide (NO 2), and meteorological data from 2013 to 2018. Five persistent high PM 2.5 exposure scenarios were defined in terms of daily mean PM 2.5 concentrations (>75 μg/m 3 and >150 μg/m 3), duration (≥2 days and ≥3 days), and whether or not there was concurrent exposure to high levels of NO 2 (daily mean NO 2 concentration >50 μg/m 3). A two-stage statistical analysis strategy based on a generalized linear model was applied to conduct a time-series analysis to assess the exposure-response relationship between persistent high PM 2.5 exposure scenarios and residents' outpatient visits for a variety of respiratory diseases, and to estimate excess outpatient visits. Results:During the period, M ( Q1, Q3) PM 2.5 and NO 2 concentrations were 61.2 (42.3, 95.1) μg/m 3 and 40.2 (31.4, 54.4) μg/m 3, respectively, and the daily respiratory disease outpatient visits were 57 (52, 66) cases. When compared with non-permanent high PM 2.5 exposure periods, exposure scenarios with PM 2.5 >75 μg/m 3 and lasting for ≥2 days caused an increased risk of outpatient visits for respiratory diseases by 2.10% (95% CI: 1.44%-2.77%), and resulted in 43 787 (95% CI: 30 025-57 757) excess visits; in this scenario, the concurrent exposure to high levels of NO 2 had a greater acute effect on respiratory disease visits than the absence of exposure to high levels of NO 2 ( P<0.001). The risk of respiratory disease visits increased substantially by 4.41% (95% CI: 3.15%-5.68%) when the daily mean PM 2.5 concentration exceeded 150 μg/m 3 for ≥2 days. Subgroup disease analyses showed that scenarios with daily mean PM 2.5 concentrations exceeding 75 μg/m 3 for ≥3 days caused a significant increase in the risk of lower respiratory tract infections, chronic lower respiratory disease, and asthma visits. Conclusions:Sustained persistent high PM 2.5 exposure increases the risk of outpatient visits for various respiratory diseases; concurrent exposure to high concentrations of NO 2 leads to a greater risk of visiting the clinic, suggesting that the prevention and control of PM 2.5 pollution should be synchronized with the control of mobile source emissions, to synergistically manage the compound pollution of PM 2.5 and NO 2 in the atmosphere.