Histone methylation is one of the epigenetic modifications. Histone methylation influences constitutive heterochromatin, genomic imprinting, inactivation of X-chromosome and gene transcription regulation. Abnormality of histone methylation is associated with several carcinomas. The discovery of enzymes that reverse histone methylation challenges the current understanding that histone methylation is a stable epigenetic marker and provides a novel way to study histone modifications.

OBJECTIVE:To provide reference for promoting the development of related legislation work on ensuring pediatric drug use in China. METHODS:The legislation process of pediatric drug use in US,the effects of current Best Pharmaceuticals for Children Act and Pediatric Research Equity Act on pediatric drug use in US were intrduced and analyzed,suggestions on guarantee-ing the accessibility and safety on pediatric drug use in China were put forward. RESULTS & CONCLUSIONS:The policy6-month period of pediatric exclusive protectionin Best Pharmaceuticals for Children Act has motivated the enthusiasm of phar-maceutical companies developing pediatric studies,while it affects the marketing of generic drugs. Pediatric Research Equity Act has achieved remarkable effect in terms of ensuring the safety of pediatric drug use by forcing pharmaceutical companies to carry out pediatrics assessments,while there is no enough force for the marketed drugs that has not been widely used for children. En-couragement and enforcement are useful methods for promoting development of pediatric drug use. It is suggested to take measures like modifingone drug two formsin Prescription Management Regulations,accelerating approvals of related pediatric drugs on the premise that safety is guaranteed,implementing tax preference for related pharmaceutical companies that produced pediatric drugs,promoting the entry of drug reimbursement list and empowering CFDA to force pharmaceutical companies to implement pedi-atric studies to promote the accessibility and safety of pediatric drugs.

Objective To investigate how patients′ suicide events affects the nurses psychologically ,and seeking for the proper intervention when it happens .Methods Using the Zung self‐evaluating forms (SAS)and self‐made questionnaire to investi‐gate 41 oncology nurse and analyze the data .Results Three days after the patients′ suicide events ,the nurses′ SAS score was (63 .30 ± 9 .21) ,which was prominently different from the average score of nurses who did not face incidents like this (P< 0 .05) ;during the following four weeks ,the nurses′ working state and personal life experience was hugely influenced ,experience of mental stress were severe .Conclusion The management should realize that the impact ,which was caused by these incidents that the pa‐tients committed suicide ,would render psychological damage to the nurses .Therefore ,it is necessary to build up an intervention sys‐tem to prevent the nurses from suffering psychological problems .

Objective To investigate the activation and clinical significance of the mammalian target of rapamycin (mTOR) pathway related protein and eukaryotic translation factor 4E-binding protein 1 (4E-BP1) in gastric cancer.Methods The activation of mTOR and 4E-BP1 in gastric cancer tissues of 38 surgical patients were detected by immunohistochemical method.The differences of phosphorylated mTOR and 4E-BP1 expression among cancerous tissues,para-cancerous tissues and normal gastric mucosa tissues and dinicopathological variables were analyzed by Chi square test and Kruskal-Wallis test.Results The positive expression rate of phosphorylated mTOR in the gastric cancerous tissues was significantly higher than that of para-cancerous tissues and normal tissues [71.1％ (27/38),50.0 ％ (19/38) and 44.7 ％ (17/38),x2 =11.031,P =0.026].The positive expression rate of downstream protein 4E-BP1 in the gastric cancer tissues was also significantly higher than that of paracancerous tissues and normal tissues [68.4％(26/38),57.9％(22/38) and 28.9％ (11/38),x2 =13.943,P=0.007].There was no correlation between phosphorylated mTOR and 4E-BP1 expression and tumor Lauren's sub-type,infiltration,differentiation degree,lymph node metastasis and patient's age.There was statistical significant difference between activated 4E-BP1 expression and tumor size in gastric cancer (H=3.86,P＜0.05).Conclsions mTOR pathway was over activated in gastric cancer.There was difference between phosphorylation degree of its downstream protein 4E-BP1 and the tumor size.

Objective:To evaluate the effects of wearing N95 mask on the quality of chest compression and fatigue.Methods:A total of 80 participants from Zhongnan Hospital with basic life support (BLS) certification conferred by American Heart Association (AHA) within two years were enrolled. After reviewing the key points of cardiopulmonary resuscitation (CPR) and grasping the operation on the manikin, they were randomized (random number) into two groups: wearing surgical masks (SM group, n=40) and wearing N95 masks (N95 group, n=40) during CPR. Each participant performed a 2-minute chest compression-only CPR on the manikin. Participants' height, body weight, Borg scores and physiological parameters before and after CPR were recorded. The quality of chest compression (including compression depth, compression rate, adequate depth proportions, adequate rate proportions, hand position and complete chest recoil) were recorded by Laerdal QCPR ? software. Student's t test and Mann-Whitney test were used to compare the differences of chest compression quality indexes between the two groups. Results:Compared with the SM group, participants in the N95 group had significantly increased median of Borg scores after CPR (16 vs 14, P=0.027), and decreased quality of chest compression, including the decline in compression depth (mean 47 mm vs 52 mm, P=0.020), compression rate (107 times/min vs 118 times/min, P=0.004), complete chest recoil rate (89.8% vs 98.1%, P=0.046), adequate depth proportions (67.4% vs 89.6%, P<0.01) and adequate rate proportions (60.6% vs 74.8%, P<0.01). Conclusions:Wearing N95 masks during CPR decreases the quality of chest compression and aggravates rescuers’ fatigue. Therefore, it is necessary to exchange rescuers more frequently to ensure the quality of chest compression when wearing N95 masks.

Nanofibers have been considered as a potential kind of sorbent for solid phase extraction, accordingly nanofiber-based solid phase extraction ( Nanofibers based solid phase extraction, NFs-SPE ) becomes a popular research point of sample pretreatment technique. This article reviewed in and abroad research status of practical application in food, environmental and biological sample preparation based on nanofibers mat, and proposed that there was a dual “structure”-“activity” relationship between target adsorption efficiency and the two structures ( nanometer morphological structure and molecular structure ) of nanofibers, which would be the key breakthrough to explore adsorption mechanism.

Aim To study the effect of genistein on contractility of isolated papillary muscles in guinea pig and its mechanisms.Methods Isolated guinea pig papillary muscles were suspended in organ baths containing KH solution,and the effect of genistein on contractility of myocardium was observed after an equilibration period.Results Genistein and isoprenaline hydrochloride showed positive inotropic effects on contractility of myocardium in a dose-dependent manner(1～100 ?mol?L~(-1)) Propranolol(1 ?mol?L~(-1)) and verapamil hydrochloride(0.5 ?mol?L~(-1)) attenuated the positive inotropic effect of isoprenaline hydrochloride(2 ?mol?L~(-1)),but did not change the effect of genistein(100 ?mol?L~(-1)).Furthermore,the enhancement of the contractility induced by elevation of extracellular Ca~(2+) concentration in papillary muscles did not show any change after pretreatment with genistein(1,10 ?mol?L~(-1)).Finally,the positive inotropic effect of genistein was attenuated partially by tamoxifen(1 ?mol?L~(-1)),however,was not influenced by sodium orthovanadate(1 ?mol?L~(-1)).Conclusions Genistein has the positive inotropic effect on guinea pig papillary muscles,which is not related to the activation of Ca~(2+) channel on cell membrane,? adrenoceptor and tyrosine kinase pathway,but this effect may involve in uptake and utilization of sarcoplasmic reticulum Ca~(2+).

Objective To investigate the combined inhibition effect and the potential mechanism of rapamycin (mammalian target of rapamycin inhibitor) and PD98059 (mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) inhibitor) on mouse colorectal cancer (CRC). Methods S-ICR mice were subcutaneously injected with 20 mg/kg of 1,2-dimethylhydrazine dihydrochloride in the nape for 20 weeks to induce CRC. From the 16th week, the mice were treated with alone or combined injection with 0.25 mg/kg rapamycin and 2.5 mg/kg PD98059. The drugs were administered for 8 weeks. Subsequently, the animals were sacrificed and dissected, the tumor sizes were measured, and the tumors were harvested for pathological assay. Furthermore, the phosphorylation of mTOR, p70S6K, and 4E-BPl proteins was detected by using immunohistoehemistry. Results The mice treated with rapamycin (44. 44 %) or PD 98059 (either alone (38.89%) or combination treatment (6.67%) were significantly less likely to develop cancer compared with mice receiving none of them (77.78%, P<0. 05). The average size of tumors was (6.15±2. 192), (8.85±3. 983), (2.917±0. 191), (16.36±6.855) mm3 respectively (P<0.05).The anti-cancer effect of the combination treatment was substantially significant. The proteins of phospho-mTOR, phospho-p70s6K and phospho-4E-BPl were significantly down-regulated after treatments (all P values < ,0.05). Conclusions Combined treatment was more effective than single-drug treatments of rapamycin or PD98059 alone for the prevention and treatment of mouse CRC. The mTOR signal pathway might be involved in the inhibitory mechanism.

Background and purpose: Thyroid carcinoma cells spread mainly through lymph node metastasis, and lymphangiogenesis plays an important role during the lymph node metastasis, but it is not very clear to understand the formation mechanism. This study was to investigate the correlative expressions of HPSE, VEGF-C, D2-40 and lymphangiogenesis in thyroid carcinoma. Methods: Immunohistochemistry SP method was used to detect the expressions of HPSE, VEGF-C and D2-40 in 77 patients with thyroid carcinoma including papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC),medullary thyroid carcinoma (MTC), 32 of them with lymph node metastasis was enrolled into the study, D2-40 stained the lymphatic vessels, and lymphatic vessel density (LVD) was scanned under the light-microscope, and the correlation among the above indexes in different thyroid carcinoma types were analyzed respectively. Results: The expressions of HPSE, VEGF-C and D2-40 were observed to have a different degree in thyroid carcinoma, and the highest expression of the protein could be seen in the patients with papillary carcinoma (P<0.05),The expression ratios of HPSE,VEGF-C and D2-40 in different carcinoma types were 54.9%, 68.6%, 12.8±5.7 for PTC, 37.5%, 50%, 8.6±1.7 for FTC, 20% and 20%, 4.9±0.8 for MTC, respectively. There were significant different expressions of HPSE, VEGF-C and D2-40 between the patients with lymph node-positive group and node-negative group (P=0.014, P=0.048, respectively). In addition, the expressions of them were positively correlated (P<0.001, r=0.616). Conclusion: HPSE, VEGF-C and D2-40 have a close relationship with lymph node metastasis, HPSE and VEGF-C are related to the lymphangiogenesis.

Objective To investigate the effects of endogenous estrogen on blood glucose level,serum insulin level,and plasma total antioxidant capacity in streptozotocin-induced diabetic female mice,and to explore possible protective effects of estrogen on pancreatic islet cells.Methods Female mice were randomly according to body weight divided into four groups:( 1 ) Sham( Sham operation and vehicle administration) ; ( 2 ) Ovx( ovariectomy and vebicle administration ) ; ( 3 ) Sham + STZ ( Sham operation and STZ administration ) ; and ( 4 ) Ovx + STZ ( ovariectomy and STZ administration).The diabetic mice were induced by intraperitoneal injection of streptozotocin (STZ,50 mg/kg ).Blood glucose levels were measured once a week.Results The blood glucose level and malondialdehyde of Ovx group were higher than that in Sham group,while total anti-oxidant capacity ( T-AOC ) was lower than those in Sham group.the blood glucose level and MDA of Ovx+ STZ group were higher than those in Sham +STZ group,while T-AOC and serum insulin level were lower than those in Sham + STZ group.Conclusions Endogenous estrogen may have some protective effects on pancreatic islet function from streptozotocin-induced diabetes mellitus in female mice.