OBJECTIVETo investigate the distribution characteristics and influencing factors of mental workload of teachers in primary schools.

METHODSNational Aeronautics and Space Administration-Task Load Index (NASA-TLX) was used to assess the mental workload levels for 397 teachers of primary schools in a city.

RESULTSThe mental workload (64.34+10.56) of female teachers was significantly higher than that (61.73+ 9.77) of male teachers (P<0.05). The mental workload (65.66+10.42) of "-35" years old group was the highest. When age of teachers was younger than 35 years old, there was a positive correlation between the mental workload and age (r=0.146, P<0.05). When age of teachers was older than 35 years old, there was a negative correlation between the mental workload and age (r=-0.190, P<0.05). The teachers with higher education level felt higher mental workload (unstandardized coefficients B=1.524, standardized coefficients /=0.111, P<0.05). There was a positive correlation between the mental workload and working hours per day (unstandardized coefficients B =4.659, standardized coefficients/3 =0.223, P<0.001).

CONCLUSIONMental workload of the teachers in primary schools is closely related to age, educational level and work hours per day. Work hours per day is an important risk factor for mental workload. Reducing work hours per day (8 hours) is an effective measure of alleviating the mental workload of teachers in primary schools.

Adolescent ; Adult ; Aged ; Faculty ; Female ; Humans ; Male ; Middle Aged ; Schools ; Stress, Psychological ; epidemiology ; Surveys and Questionnaires ; Workload ; psychology ; Young Adult

AIMTo demonstrate the specific killing of folate receptor (FR)-positive tumor cells can be achieved by folate-targeted penicillin-G amidase (PGA) combined with its prodrug substrate N-(phenylacetyl) doxorubicin (DOXP).

METHODSFolic acid was covalently linked to PGA and folate content value was determined by quantitative UV spectrophotometry. The ability of folate conjugated PGA to hydrolyze DOXP was measured by RP-HPLC. Visual demonstration of uptake by FR (+) HeLa and SKOV3 cells was detected by using FITC labeled folate-PGA and a fluorescence microscopy. The cytotoxicity of DOXP towards the cells in the presence or absence of folate-PGA was assayed by using MTT method.

RESULTSThe folate-PGA has a specific activity of 29. 8 U x mg(-1) (protein). FR selectivity was confirmed by fluorescence microscopy. The combination of DOXP prodrug with folate-PGA generated higher cytotoxicity towards the FR (+) cells than free doxorubicin. The IC50 was 0.72 micromol x L(-1) for HeLa cells and 0.75 micromol x L(-1) for SKOV3 cells, respectively. Further, the enhanced cytotoxicity reduced greatly with the addition of free folic acid.

CONCLUSIONFolate conjugated PGA did not significantly compromise PGA catalytic activity and enabled binding prodrug-activating enzyme PGA to folate receptor expressing cells, and increased the sensitivity of the cells to doxorubicin followed by administration of its prodrug substrate.

Antibiotics, Antineoplastic ; pharmacology ; Carrier Proteins ; metabolism ; Cell Line, Tumor ; Doxorubicin ; analogs & derivatives ; pharmacology ; Drug Delivery Systems ; Female ; Folate Receptors, GPI-Anchored ; Folic Acid ; chemistry ; pharmacology ; HeLa Cells ; Humans ; Inhibitory Concentration 50 ; Ovarian Neoplasms ; pathology ; Penicillin Amidase ; chemistry ; pharmacology ; Prodrugs ; pharmacology ; Receptors, Cell Surface ; metabolism

BACKGROUNDRetinal pigment epithelial (RPE) cells play an important role in the occurrence of choroidal neovascularization (CNV). Vascular endothelial growth factor (VEGF) as a positive regulatory growth factor is produced by the RPE in an autocrine or paracrine manner, promoting CNV development. Duplexes of 21 nt RNAs, known as short interfering RNAs (siRNAs), efficiently inhibit gene expression by RNA interference when introduced into mammalian cells. We searched for an efficient siRNA to interfere with VEGF expression in RPE cells and shed light on the treatment of CNV.

METHODSHuman primary RPE (hRPE) cells were cultured and identified. Three pairs of siRNAs were designed according to the sequence of VEGF 1-5 extrons and synthesized by T7 RNA polymerase transcription in vitro. To evaluate the inhibitory activity of T7-siRNAs, hRPE cells were transfected via siPORT Amine. The interfering effect of T7-siRNAs in hRPE cells was examined by semiquantitative reverse transcription-polymerase chain reaction and immunofluorescence.

RESULTSThree pairs of T7-siRNAs synthesized by in vitro transcription with T7 RNA polymerase suppressed VEGF gene expression with efficiency from 65% to 90%. T7-siRNA (B), targeted region at 207 nt to 228 nt and double stranded for 21 nt with 2 nt UU 3' overhangs, was the most effective sequence tested for inhibition of VEGF expression in hRPE cells. Compared with nontransfected cells, the mean fluorescence in hRPE cells transfected with T7-sRNAs was significantly less (P < 0.01). siRNA with a single-base mismatch and ssRNA(+) did not show suppressing effect. Furthermore, it was found that siRNAs had a dose dependent inhibitory effect (5 to 10 pmol).

CONCLUSIONT7-siRNA can effectively and specifically suppress VEGF expression in hRPE cells and may be a new way to treat CNV.

Base Sequence ; Cells, Cultured ; Choroidal Neovascularization ; therapy ; DNA-Directed RNA Polymerases ; metabolism ; Humans ; Molecular Sequence Data ; Pigment Epithelium of Eye ; cytology ; metabolism ; RNA Interference ; RNA, Small Interfering ; biosynthesis ; pharmacology ; Transcription, Genetic ; Vascular Endothelial Growth Factor A ; antagonists & inhibitors ; genetics ; Viral Proteins ; metabolism

OBJECTIVETo observe different effects of moxibustion on extracellular potassium ion in acupoint under physiological and pathological status and provide experimental evidence for exploring action mechanism of moxibustion on acupoint local.

METHODSForty female SD rats were randomly divided into a blank group, a blank-moxibustion group, a model group and a model-moxibustion group, 10 cases in each one. The complete Freund's adjuvant(CFA) was adopted to establish model of adjuvant arthritis (AA) in the model group and model-moxibustion group. No treatment was given in the blank group and model group while moxibustion was applied at "Zusan-li" (ST 36) for 30 min in the blank-moxibustion group and model-moxibustion group. The tissue fluid in "Zusanli" (ST 36) was collected with microdialysis and real-time analyzed by electrolytic analyzer. The change of concentration of potassium ion in "Zusanli" (ST 36) was observed.

RESULTS(1) Under physiological status, the concentration of extracellular potassium ion in the blank group was not changed within 150 min (P > 0.05); before the moxibustion, the concentration of extracellular potassium ion in the blank-moxibustion group was (1.21 +/- 0.31) mmol/L, and after treatment it was gradually increased and reached its peak at (2.38 +/- 0.42) mmol/L after 60 min (P < 0.05), then it was reduced. 150 min after the treatment, concentration of potassium ion was slightly higher than that before moxibustion as well as that in the blank group. The concentration in the blank-moxibustion group at 60 min was statistically significant compared with that in the blank group (P < 0.05). (2) Under pathological status, the concentration of extracellular potassium ion in the model group was not changed within 150 min, differences of which at each time point was not statistically significant (all P > 0.05). Before the moxibustion, the concentration of extracellular potassium ion was (1.09 +/- 0.12) mmol/L in the model-moxibustion group, and it was immediately increased to (1.96 +/- 0.18) mmol/L after moxibustion. 60 min and 90 min after the moxibustion, it still maintained a higher level, which was (1.87 +/- 0.29) mmol/L and (1.59 +/- 0.16) mmol/L respectively (both P < 0.05). The differences of each time point after moxibustion in the model-moxibustion group were statistically significant compared with those in the model group (all P < 0.05).

CONCLUSIONThe moxibustion could increase the concentration of potassium ion in rat's acupoint local under physiological status but time of effect is short; with moxibustion at "Zusanli" (ST 36) under pathological status, the concentration of local potassium ion is obviously increased and maintains for a long time.

Acupuncture Points ; Animals ; Arthritis, Experimental ; metabolism ; therapy ; Disease Models, Animal ; Female ; Humans ; Moxibustion ; Potassium ; metabolism ; Rats ; Rats, Sprague-Dawley

Objective:To investigate the relationship between the expression of EZH2 and the prognosis of elderly patients with rectal cancer and the mechanism of EZH2 in the progression of rectal cancer.Methods:36 cases of elderly patients with rectal cancer who underwent surgery in our hospital from January to June 2010 were included in this study.The expression of EZH2 in colorectal cancer tissues and adjacent tissues was analyzed and the differences were analyzed.All the patients were divided into positive and negative groups according to the expression level of EZH2.The correlation factors and risk factors of EZH2 expression were analyzed.All patients were followed up for 1 year to assess the quality of life of patients with prognosis and to analyze the correlation with the expression of EZH2;5-year follow-up of patients in both groups compared to 5-year progression-free survival rate of progression-free survival And overall survival(PFS) and overall survival (OS) survival curves were recorded.Results:The positive rate of EZH2 was 69.44％ in CRC and 38.89％ in cancerous tissues,and the positive rate of EZH2 in cancer tissues was significantly higher than that in adjacent tissues (P＜0.01).Age,pathologic type,The positive rate of EZH2 expression in lymph node metastasis group was significantly higher than that in lymph node metastasis group (P＜0.05).Logistic regression analysis showed that EZH2 expression was an independent risk factor of CRC lymph node metastasis.The QLQ-30 quality of life score was significantly higher in EZH2 low-expression group than that in EZH2 high-expression group (P＜0.01).The expression level of EZH2 was negatively correlated with QLQ-30 quality of life score (r=-0.573,P＜0.01).The 5-year progression-free survival rate of the 5-year EZH2 low-expression group was 86.67％ and the 5-year overall survival rate was 93.33％.The 5-year progression-free survival rate was 52.38％ 61.90％.The 5-year progression-free survival rate and 5-year overall survival rate of EZH2 low expression group were significantly higher than those of EZH2 high expression group (P＜0.05).Conclusion:The high expression of EZH2 is closely related to the progression of rectal cancer.It can be used as an important predictor of prognosis quality of life,progression-free survival time and overall survival time.

Objective:To study the expression of tumor suppressor factors SEMA3F,CYLD and miR-454 in rectal cancer.Methods:21 patients with colorectal cancer admitted in our hospital from January to March in 2016 were selected as the study materials.The tumor inhibitoryfactor SEMA3F in rectal cancer tissue,cancerous surrounding tissue and normal rectum tissue were detected respectively,CYLD and miR-454,and to analyze the correlation between tumor suppressor factors SEMA3F,CYLD and miR-454,and to explore their roles in the carcinogenesis and progression of rectal cancer.Results:The expression of SEMA3F,CYLD and miR-454 in cancer tissue,paracancer tissue and normal tissue were statistically significant (P＜0.01).The levels of SEMA3F and CYLD were significantly lower in patients with metastasis than those without metastasis,and miR-454 was significantly higher than that in patients without metastasis (P＜0.01).The expression level of SEMA3F and CYLD in CRC tissues was significantly higher than that in moderately and poorly differentiated tissues,and the expression of miR-454 was significantly lower than that in moderately and poorly differentiated ones (P＜0.01).There was significant negative correlation between tumor suppressor CYLD and miR-454 (r=-0.971,P＜0.01).There was a significant negative correlation between tumor inhibitory factor SEMA3F and miR-454(r=-0.955,P＜0.01).Conclusion:The tumor suppressor factors SEMA3F and CYLD play an important role in inhibiting the formation and proliferation of cancer cells in colorectal cancer.The expression of tumor suppressor factors SEMA3F and CYLD in colorectal cancer is high in the early stage and gradually declines with the progression of the disease.MiR-454 can promote the growth of rectal cancer cells The expression of tumor suppressor factors SEMA3F,CYLD and miR-454 in colorectal carcinoma were significantly higher than those in SEMA3F and CYLD.The expression of tumor suppressor factors such as SEMA3F,CYLD and miR-454 were significantly correlated with the progression and prognosis of rectal cancer The evaluation has important reference value.

Objective:To evaluate the safety and effectiveness of one-stop hybrid therapy for triple-vessel coronary disease.Methods:Totally 34 patients with triple vessel coronary disease were treated by off-pump coronary artery bypass graft (OPCAB)combined with percutaneous coronary intervention(PCI)from Jan.2011 to Jun.2014.All 34 patients received PCI firstly,46 stents implanted in coronary arteries,and then OPCAB were performed,41 distal anastomosis were completed. Results:The one-stop hybrid procedure was successful in all patients.Selective coronary angiography immediately after one-stop hybrid procedure showed that grafts and stents were unobstructed.There was no death during the operation and perioperative period,no episodes of angina attack,no cardio-cerebrovascular events,no bleeding postoperatively and second exploratory thoracotomy.All patients remained free from angina,cardiac function improved significantly and no patient need medical intervention during the(36 ± 8)months follow-up period.Conclusions:One-stop hybrid cardiac surgery provides a reasonable,feasible,and safe alternative for treating patients with coronary artery triple-vessel lesions,and it has good prognosis.

OBJECTIVETo evaluate the response rate and adverse reactions of exemestane (a new aromatase inactivator) in the treatment of postmenopausal women with advanced breast cancer.

METHODSOne hundred and seventy-three patients with advanced breast cancer entered this study with two patients excluded because of postmenopausal time being less than one year. Therefore, 173 patients could be evaluated for adverse events and 171 patients could be evaluated for efficacy. Exemestane, 25 mg orally daily for 4 weeks as one cycle was given.

RESULTSIn the 171 patients evaluated for efficacy, 4 (2.3%) experienced a complete response (CR) and 40 (23.4%) a partial response (PR), with the overall response rate of 25.7%. Ninety patients (52.6%) had stable disease (SD), with 25 having SD for at least 24 weeks. The clinical benefit (CR + PR + SD > or = 24 weeks) was shown in 69 (40.4%) patients. Progressive disease (PD) was shown in 37 (21.6%) patients. The untreated patients had a higher objective response rate (33.8%) than the retreated ones (18.1%) with significant difference (P = 0.019 7). The response rates for soft-tissue, bone involvement and visceral metastasis were 32.8%, 23.9%, and 12.4% (P = 0.002). There was no significant difference in different ages, time of menopause, disease-free interval or receptor status (P > 0.05). Drug-related adverse events were gastric discomfort (17.9%), malaise (17.9%), nausea (13.9%), hot flushes (11.0%) and dysphoria (5.8%). Other side reactions and abnormal laboratory parameters were observed occasionally which were irrelevant.

CONCLUSIONExemestane can be used to treat postmenopausal women with advanced breast cancer giving only mild adverse reactions which are well tolerated.

Adult ; Aged ; Androstadienes ; adverse effects ; therapeutic use ; Antineoplastic Agents ; therapeutic use ; Aromatase Inhibitors ; Breast Neoplasms ; drug therapy ; Enzyme Inhibitors ; therapeutic use ; Female ; Humans ; Middle Aged ; Postmenopause

OBJECTIVETo discuss the effect of different positive criteria on the sensitivity and specificity of sputum cytology screening for lung cancer among Yunnan tin miners.

METHODS9223 Yunnan tin miners who received at least one annual sputum cytology screening for lung cancer during the period between 1992 and 1999 were recruited in the study. At time of enrollment, all participants were aged over 40 years old, had at least 10 years of employment as an underground miner and(or) smelter, and had not been diagnosed with malignancy. In our study, a true positive was categorized as having at least one prior positive sputum screening and a diagnosis of lung cancer, while a true negative, by our definition, signified negative sputum examinations and no diagnosis of lung cancer during the follow up time. Based on different positive criteria, sensitivity and specificity of sputum cytology were computed and receiver operating characteristic (ROC) curve analysis was conducted. Z statistic was used to test the differences of the area under ROC based on Hanley and McNeil method.

RESULTSBy the end of following up on December 31, 2001, a total 500 lung cancer cases were diagnosed among 9223 participants: most were squamous cell carcinoma (55.8% (222/398)) and central lung cancers (68.5% (316/461)). 150 lung cancer cases had a previous positive sputum screening result. When positive criteria were taken as grave atypical metaplasia, moderate atypical metaplasia and slight atypical metaplasia, the corresponding sensitivities were 30.0% (150/500), 36.4% (182/500), 53.0% (265/500) respectively; while the corresponding specificities were 98.9% (8628/8723), 95.1% (8611/8723), 77.9% (7033/8723) respectively. The areas under ROC curve according to different positive criterias were 0.645 (95%CI: 0.635 - 0.654), 0.657 (95%CI: 0.668 - 0.667), 0.655 (95%CI: 0.645 - 0.664) respectively. There were no significant differences found in the comparisons between grave and moderate atypical metaplasia, grave and slight atypical metaplasia, moderate and slight atypical metaplasia(Z statistics were 0.780, 0.645, 0.209 respectively, all P values > 0.05).

CONCLUSIONWhile the standard of positive criteria for diagnosis of lung cancer decreased, the sensitivity of sputum cytology screening increased and the specificity decreased. Since there were no significant differences of accuracy for different positive criteria.

Cytodiagnosis ; methods ; standards ; Female ; Humans ; Lung Neoplasms ; diagnosis ; Male ; Mass Screening ; methods ; Sensitivity and Specificity ; Sputum ; cytology

Ornithine decarboxylase (ODC) is the rate-limiting enzyme in polyamine biosynthesis and a target for chemoprevention. Hydroxydibenzoylmethane (HDB), a derivative of dibenzoylmethane of licorice, is a promising chemopreventive agent. In this paper, we investigated whether HDB would inhibit the ODC pathway to enhance apoptosis in human promyelocytic leukemia HL-60 cells. We found ODC enzyme activity was reduced during HDB treatment. Overexpression of ODC in HL-60 parental cells could reduce HDB-induced apoptosis, which leads to loss of mitochondrial membrane potential (Deltapsim), through lessening intracellular ROS. Furthermore, ODC overexpression protected cytochrome c release and the activation of caspase-3 following HDB treatment. The results demonstrated HDB-induced apoptosis was through a mechanism of down-regulation of ODC and occurred along a ROS-dependent mitochondria-mediated pathway.
Apoptosis/*drug effects ; Caspase 3/metabolism ; Chalcones/metabolism/*pharmacology ; Chemoprevention ; Cytochromes c/biosynthesis/secretion ; Down-Regulation ; Gene Expression ; HL-60 Cells ; Humans ; Immunoblotting ; Leukemia, Myeloid/*enzymology/pathology ; Membrane Potential, Mitochondrial/drug effects ; Mitochondria/enzymology ; Ornithine Decarboxylase/antagonists & inhibitors/genetics/*metabolism ; Reactive Oxygen Species/analysis/metabolism ; Reverse Transcriptase Polymerase Chain Reaction