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Objective To explore the inhibitory effect of tetramethylpyrazine (TMP) on ultraviolet A-induced senescence as well as matrix metalloproteinase-1 (MMP-1) and-3 (MMP-3) mRNA expressions in human dermal fibroblasts (HDFs).Methods HDFs were isolated from the prepuce by enzymatic digestion, and subjected to primary culture.Cultured HDFs were randomly divided into several groups: control group cultured in high-glucose DMEM medium and receiving no treatment, three TMP groups treated with 20, 50 and 100 mg/L TMP respectively, UVA group receiving UVA radiation alone, UVA + TMP groups pretreated with 20, 50 and 100 mg/L TMP respectively for different durations followed by UVA radiation.UVA radiation was given once daily for 5 consecutive days.The 55th passage HDFs served as the P55 group (senescence control group).Subsequently, CCK-8 assay was performed to evaluate the proliferative activity of HDFs in vitro, optical microscopy to observe the morphologic changes of HDFs after UVA radiation, β-galactosidase staining to estimate the senescence in HDFs, and real-time fluorescence-based quantitative PCR to quantify the mRNA expressions of MMP-1 and MMP-3 in HDFs.Statistical analysis was carried out by one-way analysis of variance (ANOVA) followed by least significant difference (LSD)-t test or Dunnett's T3 test.Results Compared with the control group, the proliferation of HDFs was significantly but transiently inhibited in vitro after the treatment with 100 mg/L TMP for 48 hours (P ＜ 0.05), but showed no significant changes after the treatment with 20 or 50 mg/L TMP for 24, 48 or 72 hours or after the treatment with 100 mg/L TMP for 24 or 72 hours (all P ＜ 0.05).The pretreatments with TMP of 20, 50 and 100 mg/L for 24, 48 and 72 hours all promoted the proliferation of HDFs to a certain degree in the UVA + TMP groups compared with the UVA group, with significant differences in cellular proliferative activity among the UVA group, UVA + TMP groups and control group at 24, 48 and 72 hours (F =17.451,15.231, 23.535, all P ＜ 0.01).Compared with the UVA group, the proliferative activity of HDFs was significantly increased in UVA + 100-mg/L TMP group at 24, 48, 72 hours, UVA + 50-mg/L TMP group at 24 and 72 hours and UVA + 20-mg/L TMP group at 72 hours.After repetitive UVA radiation, HDFs in the UVA group experienced an increase in cell volume, granule acount, and β-galactosidase expression, which was similar to the changes in the P55 group, while the pretreatments with 20, 50 and 100 mg/L TMP for 24 hours suppressed these UVA-induced changes in HDFs.The percentage of β-galactosidase-positive HDFs was 68.417％ ± 1.181％ in the UVA group, 58.167％ ± 5.620％ in the UVA + 20-mg/L TMP group, 45.167％ ± 5.502％ in the UVA + 50-mg/L TMP group, 43.000％ ± 2.000％ in the UVA + 100-mg/L TMP group, 33.667％ ± 5.865％ in the control group, and 76.000％ ± 6.557％ in the P55 group, with significant differences among these groups (F =45.918, P ＜ 0.01).Furthermore, the UVA group significantly differed from the UVA + TMP groups and control group in the percentage of β-galactosidase-positive HDFs and mRNA expressions of MMP-1 and MMP-3 (all P ＜ 0.05).Conclusion TMP can protect HDFs against senescence induced by repetitive UVA radiation, and down-regulate the mRNA expressions of MMP-1 and MMP-3 during senescence.
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Objective To develop questionnaires to indentify research motivation and its related psychological factors for medical postgraduates.Methods The questionnaire was developed based on previous literature and case interview by using self-determination theory as the theoretical framework.Delphi method and stratified factor analysis were used to examine the reliability and validity of the questionnaire.Results The questionnaires included 2 sections:research motivation questionnaire and related psychological factors questionnaire.The Cranach's α of each questionnaire was 0.89 and 0.90 and test-retest reliability coefficient was 0.74 and 0.80.The content validity (CVI) of each questionnaire was 0.958 and 0.935,and stratified factor analysis demonstrated that the items of each dimension could account for more than 40％ of the accumulated variance.Conclusion The questionnaires have good reliability and validity and could be applied.
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Objective The current status of achievement motive levels and autonomous learning ability of nursing students was studied and compared in order to put forward suggestions to improve the achievement motive levels accordingly.Methods 119 nursing students were investigated about their achievement motive levels and autonomous learning ability by questionnaires.Then these students were divided into three groups according to their achievement motive scores and the autonomous learning ability was compared.Results The scores of Success-oriented motive of nursing students were significantly higher than that of failure-threatened motive.The total score of autonomous learning ability was(88.653+9.373)and the autonomous learning ability among these three groups was statistically different(P＜0.01).Conclusion The achievement motive greatly influenced the autonomous learning ability of nursing students.Measures should be adopted to improve the achievement motives so as to enhance their autonomous learning ability.
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Objective To investigate the protective effect of short-term moderate exercise on ischemic/reperfused myocardium and its correlation to the activation of protein kinase C(PKC).Methods Fourty Wistar rats were randomly divided into 4 groups(n=10 respectively): control group(CON group),exercise group(EXE group),exercise + PKC inhibitor group(E+C group) and PKC inhibitor group(CHE group).The occurrence of arrhythmia,the recovery of cardiac function,and infarct size were observed by using the Langendorff-ischemia/reperfusion model in isolated rat heart in vitro.Results Recovery rate of LVDP(on the 30th and 60th minute of reperfusion) and RPP(on the 20th,30th and 60 minute of reperfusion) of EXE group were higher than those of CON and E+C groups(P
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AIM: To investigate the effects of Lobelia Chinensis Lour alkaloid (LCLA) on the proliferation of cultured vascular smooth muscle cells (VSMC) induced by ET-1. METHODS: Human umbilical artery VSMC was cultured and divided into five groups: ET group, ET+LCLA group, ET+BQ-123 group,ET+ staurosporine (ST) group and control group. The cell proliferation activity was subsequently quantified by cell counting kit-8 (CCK-8) and [3H]-TdR incorporation. Flow cytometry was used to examine cell cycle. Quantitative immunohistochemical technique was used to investigate the expression of proliferating cell nuclear antigen (PCNA) and confocal microscope was used to measure the fluorescent intensity of Ca 2+. Cytotoxicity was measured by Trypan blue exclusion and LDH colorimetry tests. RESULTS: BQ-123 (10 -6mol/L), ST (10 -7mol/L) and LCLA (100, 200 and 400 mg/L) inhibited the increase in cell number, [3H]-TdR incorporation, the percentage of the S phase and markedly decreased the expression of PCNA and fluorescent intensity of Ca 2+ in response to ET-1 of VSMC (P