AIM:To compare the differences of ocular biometric parameters of age-related cataract between Tibetan and Han ethnic groups, and to analyze the distribution characteristics of ocular biometric parameters in Tibetan cataract patients.METHODS:Retrospective cohort study. A total of 661 patients(1 030 eyes)with age-related cataract confirmed in the hospital between January 2019 and December 2020 were enrolled. The parameters of axial length, anterior chamber depth, keratometry, corneal astigmatism and astigmatic axis were measured by IOL Master 500 in 483 cases(739 eyes)of Tibetan age-related cataract patients and 178 cases(291 eyes)of Han patients.RESULTS:The axial length, anterior chamber depth and corneal astigmatism of the Tibetan patients with age-related cataract were 23.33(22.81, 23.86)mm, 3.04(2.79, 3.30)mm and 0.73(0.47, 1.07)D. The mean keratometry was 43.89±1.35 D. The results indicated that Tibetan cataract patients had shorter axial lengths and smaller keratometry compared to Han patients(all P<0.05). Age in Tibetan patients was negatively correlated with axial length and anterior chamber depth, and positively correlated with keratometry(all P<0.05). Tibetan male patients had longer axial lengths, deeper anterior chambers, and flatter corneas compared to female patients(all P<0.05).CONCLUSION:There were differences in ocular biometric parameters between age-related cataract patients of Tibetan and Han ethnicities. The distribution of ocular biometric parameters in Tibetan cataract patients varied across different age groups and gender groups.

Cartilage is solid connective tissue that recovers slowly from injury, and pain and dysfunction from cartilage damage affect many people. The treatment of cartilage injury is clinically challenging and there is no optimal solution, which is a hot research topic at present. With the rapid development of 3D printing technology in recent years, 3D bioprinting can better mimic the complex microstructure of cartilage tissue and thus enabling the anatomy and functional regeneration of damaged cartilage. This article reviews the methods of 3D printing used to mimic cartilage structures, the selection of cells and biological factors, and the development of bioinks and advances in scaffold structures, with an emphasis on how 3D printing structure provides bioactive cargos in each stage to enhance the effect. Finally, clinical applications and future development of simulated cartilage printing are introduced, which are expected to provide new insights into this field and guide other researchers who are engaged in cartilage repair.

OBJECTIVE：To establish the metho d for the concentration det ermination of foretinib derivative LWK- 126 in liver microsomes，and to study its metabolism stability in liver microsomes of rats ，Beagle dogs and human. METHODS ：In the in vitro incubation system of liver microsomes ，LWK-126 was dissolved in liver microsomal incubation systems of rats ，Beagle dog and human initiated by reduced nicotinamide adenine dinucleotide phosphate solution. After incubation in water at 37 ℃ for 0，5，10，20， 30 and 60 min，the reaction was terminated with acetonitrile containing internal standard （1 μg/mL tolbutamide）. UPLC-MS/MS method was applied to determine the concentration of LWK- 126 in the incubation systems. The determination was performed on Waters BEH C 18 column with mobile phase consisted of water （containing 0.1％ formic acid ）-acetonitrile（containing 0.1％ formic acid）by gradient elution at the flow rate of 0.4 mL/min. The column temperature was 30 ℃，and the sample size was 2 μL. The mass spectral analysis was performed in a positive electrospray ionization mode ，and the full MS experiment was run with the selective reaction monitoring mode with a scanning range of m/z 50→1 200. Taking the concentration of LWK- 126 at 0 min as reference，the remaining percentage and the enzyme kinetic parameters were calculated. RESULTS ：The linear range of LWK- 126 was 0.05-15 μg/mL（R 2＝0.999 2）；the lower limit of quantification was 0.05 μg/mL，and the lowest detection limit was 0.01 μg/mL. The precision，accuracy，extraction recovery and matrix effect all met the analysis requirements of biological samples. The remaining percentage of LWK- 126 in liver microsomes of human ，rats and Beagle dogs for 60 min were （33.17±4.52）％，（3.14± 6.73）％，（1.38±5.85）％；t1/2 of them were 33.15，11.76，5.62 min；the clearance rates were 38.45，118.81，245.76 μL（/ min·mg）， respectively. CONCLUSIONS ：The method for the content ； determination of LWK- 126 in liver microsomes is established successfully. The order of metabolic stability of LWK- 126 in 〔2016〕4015） liver microsomes of different species is human ＞rats＞Beagle dogs.

OBJECTIVE：To establish the method for determining protein binding rate of dipeptidyl peptidase- 4 inhibitor LGT- 6 in different species of plasma ，and to compare their difference. METHODS ：By equilibrium dialysis ，LGT-6（3，30，300，3 000 nmol/L）was equilibrated in rat ，monkey and human plasma （i. e. internal dialysis solution ）for 48 h，using phosphate buffer as the external dialysis solution. The concentration of LGT- 6 in internal and external dialysis solution was determined by UPLC-MS/MS using tolbutamide as internal standard ，and the plasma protein binding rate was calculated. The determination was performed on ACQUITY UPLC HSS T 3 column with water （containing 0.01％ formic acid ）-acetonitrile（containing 0.01％ formic acid ）as mobile phase at the flow rate of 0.6 mL/min. The column temperature was 40 ℃，and the sample size was 2 μL. The ion source was electrospray ion source ，and the multiple ion monitoring mode was used to carry out positive ionization scanning. The ion pairs for quantitative analysis were m/z 487.0→434.3（LGT-6），m/z 271.1→172.0（internal standard ），respectively. RESULTS ：At the concentrations of 3，30，300，and 3 000 nmol/L，the protein binding rates of LGT- 6 in rat plasma were （96.25±0.97）％，（84.16± 1.24）％，（78.25±0.61）％，（66.63±0.95）％；the protein protein binding rates in monkey plasma were （98.54±0.58）％，（87.27± 1.01）％，（79.35±0.86）％，（66.69±0.54）％；the protein binding rates in human plasma were （99.40±1.03）％，（84.48± 1.15）％，（77.62±0.77）％，（66.93±0.48）％. At the same concentration ，the protein binding rates of LGT- 6 in rat ，monkey and human plasma had no significant difference （P＞0.05）. In the same species of plasma ，there were significant differences in the plasma protein binding rates of different concentration of LGT-6 among those groups （P＜0.05），and it decreased with 才〔2016〕4015） the increase of drug concentration. CONCLUSIONS ： The method for the determination of plasma protein binding rate of LGT-6 is successfully established. The data revealed that the protein binding rate of LGT- 6 is concentration-dependent ， there was no obvious spec ies difference on protein binding rates of LGT- 6 in rat ，monkey and human plasma under the same concentration.

Objective: To evaluate the safety and efficacy of foam sclerotherapy for bleeding internal hemorrhoids. Methods: Consecutive adult patients (aged 18-60 years) with bleeding hemorrhoids were prospectively enrolled between March 2017 and March 2018. All patients were randomly assigned to the foam sclerotherapy (FS) group and the liquid sclerotherapy (LS) group. The foam and liquid sclerotherapy of hemorrhoids nucleus was performed by cap-assisted colonic endoscopy. Results: A total of 108 patients were enrolled, including 62 males (57.4%) with mean age of 44.0±7.6 years. There was no significant difference in gender, age, or body mass index between the FS (n = 55) group and the LS (n =53) group. The total amount of lauromacrogol injection in the FS group was 3.7±0.9 mL, which was significantly lower than that in the LS group (8.0±2.2 mL, P<0.001). In the LS group, 8 patients (15.1%) developed bleeding after needle removal, which was significantly higher than that in the FS group [5.5%(3/53), P=0.022]. Significant pain was found in 2 patients (3.8%) in the LS group and 0 in the FS group (P= 0.025). The short-term cure rate and effective rate of the FS group were 87.3% (48/55) and 9.1% (5/55), while those were 69.8% (37/53) and 22.6% (12/53) in the LS group, respectively (P=0.046). Conclusion Foam sclerotherapy is safe and effective in the treatment of bleeding internal hemorrhoids.

The dissertation review and defense process of medical science degree graduate stu-dents has become a mere formality because of the manner of postgraduates cultivation, cultural factors and objective factors, resulting in poor quality of degree dissertation. This paper deeply analyzed the reasons for the above problems, and proposed five aspects of adjustment through the reviewer choosing, review process, evaluation scale, evaluation content and evaluation opinions to perfect the eval uation system. It also proposed four aspects of adjustment through strengthen the significance, thesis defense, defense supervision content development process and the detalled reply results to perfect defense system.

AIM:To explore the effects of confluent endothelial progenitor cells (EPCs) derived from young and aged rats on the phenotype conversion, proliferation and migration of vascular smooth muscle cells ( SMCs) .METH-ODS:Mononuclear cells were obtained from the bone marrow of young (1~2 month old) and aged (19 to 26 month old) Sprague-Dawley rats and cultured with medium DMEM/F12 ( containing 15% fetal bovine serum, endothelial cell growth supplements (ECGs) 100 g/L, 1 ×105 units/L of penicillin and streptomycin, respectively).EPCs were characterized as double positive for DiI-Ac-LDL uptake and lectin binding.Abdominal aorta was obtained from 1 to 2 month old Sprague-Dawley rats.Vascular SMCs were cultured by tissue explant method and identified byα-SM-actin immunofluorescence.In transwell co-culture system, the confluent EPCs located in the upper chamber and SMCs were seeded on the lower cham-ber.The experiments were divided into passage 3 SMCs group (P3), passage 4 SMCs group (P4), passage 4 SMCs co-culture with EPCs derived from young rats group (P4YE) and passage 4 SMCs co-culture with EPCs derived from aged rats group (P4AE).The protein expression ofα-SM-actin and osteopontin was detected by Western blotting.[3H]-TdR incor-poration assay was used to determine the proliferation.SMC migration was analyzed by scratch wound healing assay.RE-SULTS:Compared with P3 group,α-SM-actin expression in P4 group significantly decreased and osteopontin protein ex-pression obviously increased, whereas no significant change was found in P4YE group.Compared with P4 group, confluent EPCs derived from young and aged rats both markedly increased α-SM-actin and decreased osteopontin expression in P4 SMCs.Compared with aged rat-derived EPCs, young rat-derived EPCs were more effectively to induce a delayed SMC phe-notype transition (from contractile phenotype to a synthetic phenotype), and to inhibit SMC proliferation and migration. CONCLUSION:Co-culture of confluent EPC induces a delayed vascular SMC phenotype transition and inhibits SMCs pro-liferation and migration.Young rat derived EPCs are more effective to induce a delayed vascular SMC phenotype transition and has stronger inhibitory effects on SMCs proliferation and migration compared with that derived from aged rats.

Objective To increase the awareness of the incidence trend of ischemic colitis and improve the level of diagnosis and treatment.Methods From January 2004 to December 2013,the clinical data of 89 in patients with ischemic colitis were retrospectively analyzed.At the same period,100 patients diagnosed as chronic colitis were enrolled as control group.The laboratory findings of patients with ischemic colitis were compared with those of control group.Non normal distribution data were analysed by non parametric test.Results The annual person-times of patients with ischemic colitis and the percentages accounted in the whole hospital annual person-times increased year by year in recent 10 years,which was one person time and 0.01％ in 2004 increased to 41 person-times and 0.11％ in 2013.The average age of the 89 patients was (63.5±12.7) years,and the male to female ratio was 1∶2.18.The most common underlying disease in the 89 patients was hypertension,accounted for 43.8％.Thirty-eight patients had a history of abdominal surgery,and eighteen patients with appendectomy,accounted for 20.2％.Seventy-eight patients had abdominal pain and defecation desire.Seventy-four patients complained of hematochezia.Compared with control group,there was no statistically significant difference in fasting blood glucose,triglyceride,total cholesterol,blood platelet levels and prothrombin time (all P＞0.05).While the levels of C reactive protein and Ddimer were higher than those of control group (89.21 mg/L vs 61.29 mg/L,90.13 μg/L vs 59.39 μg/L; Z=-3.959,-4.377; both P＜0.05).The images of computed tomography (CT) indicated thickened bowel wall in lesion segment.The results of colonoscopy showed that in the left colon and rectum were the predilection sites,accounted for 93.88％ (138/147).The average hospital stay was (10.59 ± 5.97) days and t he recurrence rate was 3.37 ％ (3 / 89).The percentage of chronic cases was 2.25 ％ (2/89),and no death was reported.Conclusions The incidence of ischemic colitis significantly increased in recent years.Patients with abdominal pain and/or hematochezia should be considered,especially those over 60 years old.Receiving colonoscopy as earlier as possible was helpful for the diagnosis.

Cadmium (Cd) is a well-known hepatotoxic environmental pollutant. We used rat hepatocytes as a model to study oxidative damage induced by Cd, effects on the antioxidant systems, and the role of N-acetylcysteine (NAC) in protecting cells against Cd toxicity. Hepatocytes were incubated for 12 and 24 h with Cd (2.5, 5, 10 microM). Results showed that Cd can induce cytotoxicity: 10 microM resulted in 36.2% mortality after 12 h and 47.8% after 24 h. Lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase activities increased. Additionally, reactive oxygen species (ROS) generation increased in Cd-treated hepatocytes along with malondialdehyde levels. Glutathione concentrations significantly decreased after treatment with Cd for 12 h but increased after 24 h of Cd exposure. In contrast, glutathione peroxidase activity significantly increased after treatment with Cd for 12 h but decreased after 24 h. superoxide dismutase and catalase activities increased at 12 h and 24 h. glutathione S-transferase and glutathione reductase activities decreased, but not significantly. Rat hepatocytes incubated with NAC and Cd simultaneously had significantly increased viability and decreased Cd-induced ROS generation. Our results suggested that Cd induces ROS generation that leads to oxidative stress. Moreover, NAC protects rat hepatocytes from cytotoxicity associated with Cd.
Acetylcysteine/*metabolism ; Animals ; Antioxidants/*metabolism ; Cadmium/*toxicity ; Cell Survival/drug effects ; Cells, Cultured ; Environmental Pollutants/*toxicity ; Hepatocytes/drug effects/metabolism ; *Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/*metabolism