AIM: This experiment was performed to evalu at e the significance of the expression of different types of protein kinase C (PKC ) in lung squamous cell carcinoma induced by methylcholanthrene(MAC).METHODS: Lung squamous cell carcinoma in Wistar rats was induced with MAC for 12 weeks. The stage of the cancer development was determined histop athologically. Immunohistochemistry method was used to study the expression of different types of protein kinase C ?,?,?,? in lung squamous cell carcinoma. RESULTS: The level of expression of PKC ? in lung squamous cel l car cinoma was significantly higher than that in peripheral lung tissues and normal lung tissues (24.08%?2.93%,5.00%?2.10%,1.96%?0.29%,respectively. P

AIM:To investigate the changes of histone modifications during the activation of primarily cultured rat hepatic stellate cells ( HSCs) and the relationship between histone modification patterns andα-smooth muscle actin (α-SMA) expression, and to explore the roles of histone modifications in the activation of HSCs.METHODS:The rat HSCs were isolated by in situ perfusion of collagenase combined with density gradient centrifugation, cultured in vitro and identi-fied by immunofluorescence staining.The morphological features of the cells were observed under inverted microscope.The changes of desmin and α-SMA during the activation of HSCs were detected by immunofluorescence staining and Western blotting.The levels of histone 3 lysine 4 dimethylation (H3K4me2), histone 3 lysine 9 dimethylation (H3K9me2), his-tone 3 lysine 9 acetylation (acH3K9) and histone 4 lysine 12 acetylation (acH4K12) in quiescent HSCs and activated HSCs were determined by Western blotting.RESULTS: The morphology of HSCs shifted from a quiescent phenotype to highly activated myofibroblast during the culture.Immunofluorescence staining and Western blotting showed that the expres-sion levels of α-SMA and desmin were increased over time and reached maximum at 15 d.According to the results of cell morphology and immunofluorescence staining, the cells cultured for 24 h and 15 d were quiescent and activated HSCs, re-spectively.Compared with quiescent HSCs, there were higher H3K4me2 and lower H3K9me2, acH3K9 and acH4K12 modification levels in activated HSCs ( P<0.01 ) .CONCLUSION: Histone modifications show anomalous expression during the activation of primarily cultured rat HSCs.Histone modifications may contribute to the transdifferentiation of HSCs and the development of hepatic fibrosis.

Objective To determine the effects of histone deacetylase inhibitor suberoylanilide hydroxamic acid(SAHA) on the cell proliferation and apoptosis of the human hepatic stellate cell line LX-2.The possible underlying mechanisms were also investigated.Methods The LX-2 cells were treated with SAHA in vitro.The morphology of LX-2 cells in different concentrations groups was observed by inverted microscope;the proliferation of LX-2 cells was measured by MTT assay;the Annexin V-FITC and PI staining was used to detect the apoptosis of LX-2 cells by flow cytometry and fluorescence microscope;the expression of α-SMA,collagen Ⅰ,acH3K9,acH3K14 and acH3K18 were detected by Western blot.Results The morphology change of LX-2 cells showed that SAHA inhibited the proliferation rate of LX-2 cells and in a dose dependent manner(P<0.05).The LX-2 cells were sensitive to SAHA along with time increasing,and in a time-dependent manner(P<0.05).Western blot showed that the expression levels of α-SMA and collagen-Ⅰ were significantly lower(P<0.05),on the contrary,the acetylation levels of acH3K9,acH3K14 and acH3K18 were significantly higher (P<0.05).Conclusions The increased acetylation of the histone acH3K9,acH3K14,acH3K18 and the lower expressed α-SMA and collagen-Ⅰ in LX-2 cells may be one of the mechanisms of SAHA.

AIM: To study the role of TGF-?/Smad pathway in the development of renal fibrosis in diabetic nephropathy.METHODS: Rats were induced to diabetic nephropathy by using tail intravenous injection of STZ.The expression of TGF-?_1,Smad2/3 protein and mRNA in kidney were examined at 2,4,8 and 16 weeks after STZ induction.CTGF,collagen-Ⅲ,PAI-1 mRNA expression in kidney at 16 weeks of STZ-induced diabetic nephropathy and normal rats were studied by RT-PCR.RESULTS: Weak TGF-?_1,Smad2/3 protein were detected in normal renal tissues while strong TGF-?_1,Smad2/3 staining were observed in renal tissues of diabetic nephropathy(0.057?0.030/0.223?0.040;0.017?0.010/0.153?0.010,respectively,P

AIM: To investigate the effect of a Chinese medicime, Dan-Shao-Hua-Xian capsule, on liver fibrosis induced by CCl_4 by observation of apoptosis and cell cycle variation in the liver cells. METHODS: Animal models were produced through eight-week treatment of the rats with CCl_4, alcohol and diet of high fat/low proteins, and then administration of Dan-Shao-Hua-Xian to the rats (1 g/kg) via stomach-tube-pouring for eight weeks was performed. Liver index, serum hyaluronic acid (HA) and glutamate pyruvate transaminase (ALT) were measured and hydroxyproline (Hyp) content in urine were determined. The extent of the liver fibrosis was observed under light microscope and apoptosis and cell cycle were also examined by cytometry between the two groups. RESULTS: Compared to the liver fibrosis group, the liver index, serum HA, ALT in the treatment group decreased, the development of liver fibrosis delayed, the urine Hyp and the number of apoptosed cells and the ratio of G_0/G_1 cells increased, as well as the S phase cells decreased, yet unable to return to normal. All those changes detected were statistically significant. CONCLUSIONS: The Dan-Shao-Hua-Xian is effective in treating the CCl_4-induced liver fibrosis in rats partly by virtue of inhibition of the growth of hepatic stellate cells and induction of apoptosis.

Objective:To investigate the current situation of students' academic procrastination behavior in medical colleges and universities and its influencing factors, and to put forward suggestions to reduce the academic procrastination of medical students.Methods:A total of 1 327 undergraduate students from three medical colleges and universities in Heilongjiang Province were randomly selected to receive questionnaire investigation on life satisfaction, anxiety, and academic procrastination. SPSS 23.0 was used for data analysis.Results:①The total procrastination scores of medical students were (35.00±8.92) points. ②There were statistical differences in the academic procrastination of medical students with different genders, whether the only children, the reasons for choosing the major, and the level of achievement ( P < 0.05). There was no statistical difference in academic procrastination among medical students of different ages and grades ( P > 0.05). ③Medical students' procrastination was positively correlated with their anxiety level ( r = 0.102, P < 0.01), and negatively correlated with life satisfaction ( r = -0.117, P < 0.01). ④Regression analysis showed that the following six predictive variables including the level of achievement, gender, life satisfaction, anxiety, reasons for choosing the major, and whether the only children could effectively explain the variance of 14.2% academic procrastination of medical students. Conclusion:The overall degree of academic procrastination of medical students is higher than that of non-medical students. And the students' achievement level, gender, life satisfaction, anxiety, the reasons for choosing this major and whether the only child are the influencing factors of academic procrastination.

AIM:To study the effects of suberoylanilide hydroxamic acid (SAHA) on the apoptosis of hepatic stellate cells (HSCs) and expression of associated proteins, and to investigate the mechanisms of SAHA to induce apoptosis.METHODS:The rat HSCs were isolated by OptiPrep gradient centrifugation method.The effect of SAHA on HSC proliferation was detected by real-time cell analyzer.The morphological changes of HSCs treated with SAHA at different concentrations were observed under inverted microscope.The apoptotic rates of HSCs were analyzed by flow cytometry with Annexin V-FITC/PI staining and fluorescence microscopy.The protein expression of α-smooth muscle actin (α-SMA), collagen I, tissue inhibitor of metalloproteinase 1 (TIMP1), glucose-regulated protein 78 (GRP78) and histone deacetylase 6 (HDAC6) was detected by Western blotting.The interaction of GRP78 with HDAC6 in the HSCs was determined by co-immunoprecipitation.RESULTS:HSCs were successfully isolated and cultured for 14 d, during which the HSCs changed gradually from rest state to active state.SAHA significantly inhibited the proliferation of HSCs in a time-and dose-dependent manner (P<0.05).The results of Western blotting showed that the protein expression levels of α-SMA, TIMP1, collagen-I and HDAC6 were significantly decreased (P<0.05), while GRP78 was significantly increased (P<0.05).Compared with activated HSCs, GRP78 and total acetyl-lysine protein were significantly increased in the co-immunoprecipitated HSCs treated with SAHA, while HDAC6 protein was significantly decreased, indicting that GRP78 formed a complex with HDAC6.CONCLUSION:The anti-hepatic fibrosis effect of SAHA may be related to down-regulation of HDAC6 and up-regulation of acetylated GRP78, thus inducing endoplasmic reticulum stress of HSCs and promoting the apoptosis of HSCs.

Objective:To study the clinical characteristics and etiological distribution characteristics of plastic bronchitis in children, analyze its early warning indicators, and evaluate the clinical diagnosis and treatment effect of flexible bronchoscopy.Methods:The clinical data of 232 children with severe pneumonia admitted to Guiyang Maternal and Child Health Hospital from January 2019 to February 2021 were retrospectively analyzed.The children were divided into the plastic bronchitis group and non-plastic bronchitis group according to bronchoscopic results.The gender, age, clinical manifestations, auxiliary examinations, imaging features, bronchoscopy findings and treatment of the children were collected, compared and analyzed, comparison between two groups by t test and χ2 test. Results:A total of 232 children were included in this study, including 98 cases in the plastic bronchitis group and 134 cases in the non-plastic bronchitis group.The main symptoms of both groups were fever, cough and shortness of breath.The age of onset in the plastic bronchitis group was (54.640±37.085) months, and the age of onset in the non-plastic bronchitis group was (14.870±19.813) months.The difference in the age of onset between the two groups was statistically significant ( t=9.656, P<0.001). The average hospitalization days of the plastic and non-plastic bronchitis groups were (16.133±6.227) d and (12.690±4.287) d, respectively.Significant difference was found in the average hospitalization days between the two groups ( t=4.721, P<0.001). The average fever days of the plastic bronchitis group were (10.090±3.473) d, and the average fever days of the non-plastic bronchitis group were (6.030±4.850) d. There was significant difference in the average fever days between the two groups ( t=5.654, P<0.001). The age of onset, hospitalization days, and fever days of the plastic bronchitis group were larger than those of the non-plastic bronchitis group (all P<0.001). The physical examination suggested that 40% (39/98) of patients in the plastic bronchitis group had reduced the breath sounds, and this percentage was significantly higher than that in the non-plastic bronchitis group[6%(8/134)]. The plastic bronchitis group had lower partial pressure of blood oxygen (PO 2) and oxygen saturation (SO 2) levels than the non-plastic bronchitis group (all P<0.01). The plastic bronchitis group had a higher percentage of neutrophils (N), C-reactive protein (CRP) level, procalcitonin (PCT) level, lactate dehydrogenase (LDH) level and D-dimer level than the non-plastic bronchitis group (all P<0.01). According to the imaging results, in the plastic bronchitis group, lung consolidation was found in 72 cases (73%, 72/98), atelectasis in 32 cases (33%, 32/98), and pleural effusion in 33 cases (34%, 33/98). In the non-plastic bronchitis group, 65%(87/134) cases had lung consolidation, 5%(7/134) cases had atelectasis, 3.7% (5/134) cases had pleural effusion.The first pathogen detected in 46.9% of the patients in the plastic bronchitis group was Mycoplasma pneumoniae (MP), and the percentage was significantly higher that in the non-plastic bronchitis group (11.1%). Flexible bronchoscopy was performed on both groups at their admission.The plastic bronchitis group received the flexible bronchoscopy check for (2.960±1.157) times on average, and the non-plastic bronchitis group was tested for (1.140±0.371) times on average.Of 98 children in the plastic bronchitis group, 95 cases were improved and discharged, 2 cases were transferred, and 1 case died.All 134 children in the non-plastic bronchitis group were improved and discharged. Conclusions:Preschool and school-age children, fever ≥10 d, PCT, CRP, LDH, D-dimer levels are early warning signs of plastic bronchitis clinically.MP is still the primary pathogen causing plastic bronchitis.Flexible bronchoscopy technique is a key measure for timely diagnosis and effective treatment of plastic bronchitis.

Objective To examine the current situation of the career plateau among anesthesiologists and analyze the impact of occupational stressors on it. Methods A questionnaire survey was conducted on the anesthesiologists. A total of 300 questionnaires were distributed and 278 questionnaires were effectively collected. Statistical analysis using SPSS 19.0 was performed to assess the status quo of career plateau among anesthesiologists. Pearson correlation analysis and stepwise regression analysis were used to analyze the influence of occupational stressors on career plateau . Results The average value of occupational stressors among anesthesiologists was (3.22±0.55), and the average value of career plateau was (3.90±0.70). Occupational interest in the occupational stressors of anesthesiologists is negatively correlated with the occupational plateau (r=-0.552, P<0.01), and career development is negatively correlated with occupational plateau (r=-0.541, P<0.01) as well. Both occupational interest and career development show a negative predictive effect on the career plateau (β=-0.359, P<0.01 andβ=-0.334, P<0.01, respectively). Conclusion Career plateau among anesthesiologists is at a medium-to-high level. Occupational interest and occupational development in occupational stressors have a negative predictive effect on occupational plateaus, so hospital managers should pay attention to them.