Polycythemia vera (PV) is a chronic clonal myeloproliferative disorder of hematopoietic stem cell characterized by a pronounced symptom burden, including fatigue, pruritus, and symptomatic splenomegaly, along with an increased risk of thrombosis and the potential for evolution to myelofibrosis (MF) and secondary acute myeloid leukemia. Research on pathogenesis, diagnosis and treatment of PV has made a great progress since the discovery of JAK2 V617F mutation in 2005. The change of epigenetics plays an important role in the progression of PV, and the drugs for apparent genetic alteration may improve the life quality of PV patients.

Objective To investigate the association of platelet-derived growth factor(PDGF)-B gene single nucleotide polymorphism(SNP) and plasma PDGF-BB level with in-stent restenosis(ISR) in elderly patients.Methods 157 patients who had undergone coronary artery stenting for more than half year were divided into ISR group(n=74) and NISR group(non-ISR,n=83) according to the angiographic diagnosis of in-stent restenosis (ISR).Plasma level of PDGF-BB was measured by enzyme-linked immunosorbent assay(ELISA).DNA was isolated from leukocytes.Two SNPs of the PDGF-B gene(rs1800818 and rs1800817) were determined by Taqman Quantitative Real-Time PCR with TaqMan-MGB probe.Results There were no significant differences in genotype frequency of rs1800818 AA,AG,GG between ISR group and NISR group(x2 =4.48,P＞0.05).The frequency of rs1800818A allele was much higher in ISR group than in NISR group(x2 =5.33,P＜0.05).There were no significant differences in genotype frequency of SNP rs1800817 AA and AC(x2 =0.06,P＞ 0.05) and allele frequency of SNP rs1800817 A and C(x2 =0.06,P＞0.05) between ISR group and NISR group,while genotype CC was not found.The plasma level of PDGF-BB was higher in ISR group than in NISR group [(6.53±3.65) ng/L vs.(5.07±2.45) ng/L,t=2.92,P＜0.01].Plasma level of PDGF-BB in patients with rs1800818 AA genotype was significantly higher in ISR group than in NISR group [(9.94 ± 4.60) ng/L vs.(5.90 ± 2.98) ng/L,t =2.69,P＜0.05].Multivariable logistic regression analysis showed that plasma PDGF-BB level was the risk factor for ISR (OR =1.187,95.0％ CI:1.054 1.337,P＜0.01).Conclusions High plasma PDGF-BB level is the risk factor for ISR,but PDGF-B gene SNPs rs1800818 and rs1800817 are not associated with the occurrence of ISR.

Objective To investigate the relationship between plasma level of platelet derived growth factor-BB (PDGF-BB), coronary heart disease (CHD) and the severity of coronary artery stenosis. Methods A total of 262 patients hospitalized in Department of Cardiology, Tianjin Chest Hospital were collected in this study. According to the medical history, symptoms, laboratory examination and the results of coronary angiography, patients were divided into stable angina pectoris (SAP) group (n=57), acute coronary syndrome (ACS) group (n=119) and normal control group (n=86). The ACS group was divided into three subgroups:single vessel group (n=38), double vessel group (n=35) and multiple vessel group (n=46). The general clinical data, biochemical parameters and plasma PDGF-BB levels were compared between SAP group, ACS group and control group. Spearman correlation analysis was used to analyze the relationship between PDGF-BB level, high-sensitivity C-reactive protein (hs-CRP) and Gensini scores. Logistic regression analysis was used to analyze the risk factors of coronary heart disease. Results (1) The plasma levels of hs-CRP and PDGF-BB were significantly higher in ACS group than those in control group and SAP group (P<0.05). (2) Spearman correlation analysis showed that there was no correlation between plasma levels of PDGF-BB and hs-CRP and Gensini score (P>0.05). (3) There was no significant difference in plasma level of PDGF-BB between single vessel group, double vessel group and multiple vessel group (P > 0.05). (4) Logistic regression analysis showed that high plasma level of PDGF-BB was the risk factor for coronary heart disease. Conclusion PDGF-BB plasma level is associated with the pathogenesis of coronary heart disease, which may reflect the instability of coronary atherosclerotic plaques, but it is not an index to evaluate the severity of coronary stenosis.

Mitogen activated protein kinase(MAPK)is one of the four biggest signal transduction systems which contain four subtribes named p38,ERK5/BMK1,ERK and JNK/SAPK respectively.Previous studies have shown that MAPK pathway is involved in growth,cell differentiation,perishing,the synchronization of cell function and so on.ERK/MAPK,one of the members of MAPK family,and Sma-and MAD-related(Smad)play important roles in the proliferation of fibroblast,modulating inflammation mediator production as well as transferring factors activity in the process of pulmonary fibrosis(PF).This review focuses on relationship between Smads and ERK in the pathogenesis and progression of PF.

Objective To investigate the effect and mechanism of Imatinib mesilate (Imatinib) on intimal hyperplasia of rabbit carotid arteries after balloon injury. Methods Thirty adult Newzealand rabbits were randomly divided into three groups:group A, B and C. Their right carotid arteries were injuried then administered with 0, 25 or 50 mg/kg of Imatinib dai?ly for 14 consecutive days when the rabbits were sacrificed. The carotid arteries were harvested and sectioned for HE-stain?ing and immunohistochemisty staining. Real-Time PCR was used to examine transcription levels of PDGF-B and PDGFR-βmRNA. The plasma level of PDGF-BB was assayed by ELISA. Results Arterial intimal hyperplasia and stenosis following balloon injury were seen in three groups. Thickness and area of neointima, ratio of thickness of intima to media, ratio of area of intima to media and mRNA level of PDGF-β are all higher in group A than those in group B than those in group C (P<0.01). By contrast, the mRNA transcription level of PDGFR-β increased significantly in group C than that in group A (1.236±0.356 vs 0.708±0.372;t=2.91;P<0.01). Plasma level of PDGF-BB increased in all three groups after balloon injury than that in the baseline (P<0.01). The transcription level of PDGF-BB is higher in group A than that in group B and in group C (ng/L:23.464±3.542, 19.504±2.454, 16.588±1.207, F=17.322, P<0.05). There was no difference between group B and C. There was positive correlation between mRNA transcription level of PDGF-B and plasma level of PDGF-BB ( r=0.806, P<0.01). Conclusion Vascular injury can cause intimal hyperplasia and increased PDGF-B mRNA transcription. Imatinib mesilate could inhibit the intimal hyperplasia through down regulating PDGF-B mRNA transcription.

Objective To explore the distribution and antimicrobial resistance of pathogens causing healthcare-associated infection(HAI) in a hospital,and provide theoretical basis for rational use of antimicrobial agents and control of HAL Methods HAI occurred in patients in this hospital between 2011 and 2015 were chosen,distribution of major pathogens causing HAI and antimicrobial resistance were analyzed.Results A total of 852 pathogenic strains were isolated,including 458 (53.75 ％) strains of gram-negative bacteria,259 (30.40 ％) fungi,and 135 (15.85 ％) gram-positive bacteria,the top 4 pathogens were Klebsiella pneumoniae (n =159,18.66 ％),Candida albicans (n =119,13.97％),Acinetobacter baumannii (n =81,9.51％),and Escherichia coli (n =74,8.69 ％).Isolation rate of gram-negative bacteria increased from 47.41 ％ in 2012 to 61.57％ in 2015,fungi increased from 24.78％ in 2011 to 34.45％ in 2014 (2015 was 27.95％),gram-positive bacteria decreased from 26.55％ in 2011 to 10.48％ in 2015.Resistance rates of Escherichia coli and Klebsiella pneumoniae to imipenem and meropenem were 8.11％-12.58％;Acinetobacter baumannii had the lowest resistance rate to cefoperazone/sulbactam(23.46％),resistance rate of Candida albicans to fluconazole was up to 59.66％,vancomycin-resistant gram-positive bacteria was not found.Conclusion The major pathogens causing HAI are opportunistic pathogens,antimicrobial resistance is serious,the species and distribution varies with different years,it is necessary to enhance specimen detection rate,strengthen the monitoring on pathogen resistance,and use antimicrobial agents rationally.

Objective To investigate the predictive value of the non-invasive indicator deceleration capacity of heart rate (DC) in the sudden cardiac death (SCD) after acute myocardial infarction. Methods A total of 417 myocardial infarc?tion patients with ST-segment elevation in sinus rhythm were enrolled in this study. DC was assessed from data of 24-hour ECG Holter. Regular follow-ups were carried out within 12 months. The SCD events were recorded and compared with pa?tients without SCD. Results During 12 months of follow-up, 20 patients were died due to SCD (4.8%). Compared with sur?vival group, patients showed significantly lower left ventricular ejection fraction (LVEF, 0.393 ± 0.065 vs 0.528 ± 0.042, P<0.05) and DC [(2.85±1.66) ms vs (5.49±1.71) ms,P<0.05]in SCD group. Multivariate Cox proportional hazard regression analysis showed that lower LVEF(<0.35)[RR: 2.167(1.384-4.661), P=0.013]and DC (DC<4.5 ms)[RR: 3.706(2.709-5.374),P=0.020]were risk factors for the occurrence of SCD. The prediction sensitivity by the decreased LVEF and DC was 52.1%and 76.4%respectively, and the specificity was 84.5%and 86.1%respectively. Conclusion The decreased value of DC after acute myocardial infarction can predict the SCD events.

Objective To investigate the effects of pretreatment with remifentanil on hemorrhagic shock (HS)-induced acute liver injury in rabbits.Methods Thirty-two New Zealand white rabbits,weighing 2.0-2.5 kg,were randomly divided into 4 groups (n=8 each): sham operation group (group S) ; group HS,low-dose remifentanil group (group RL) ; high-dose remifentanil group (group RH).Remifentanil was infused at 0.66 and 1.32 μg· kg-1 · min-1 for 145 min in groups RL and RH respectively,while the equal volume of normal saline was infused in group C.HS was induced by withdrawing blood from the left femoral artery at 15 min after continuous infusion of normal saline or remifentanil and mean arterial pressure (MAP) was reduced to 40 mm Hg.MAP was reduced to 35-45 mm Hg and maintained at this level for 120 min in groups HS,RL and RH.Blood samples were taken for determination of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities before administration (T0),immediately before blood letting (T1),and at 10,30,60 and 90 min after blood letting (T3-6).The animals were then sacrificed and the livers were immediately removed for microscopic examination.Results Compared with group S,the serum ALT activity at T5 and T6 and serum AST activity at T4-T6 were significantly increased in the other three groups (P ＜ 0.05).Compared with group HS,the serum ALT activity at T5 and T6,and serum AST activity at T4-T6 were significantly decreased in group RH,and no significant change was found in group RL (P ＞ 0.05).Compared with group RL,the serum ALT activity at T5 and T6,and serum AST activity at T4-T6 were significantly decreased in group RH (P ＜ 0.05).The serum ALT activity at T5 and T6 and serum AST activity at T4-T6 were significantly increased in groups HS,R and RH than those at T0 (P ＜ 0.05 or 0.01).The patho1ogical injury was attenuated in group RH compared with groups HS and RL.Conclusion Remifentanil pretreatment can attenuate HS-induced acute liver injury in rabbits,and the effect is related to the dose.

OBJECTIVE:To provide basic industrial research and development recommendations for the supply-side structural reform in drug distribution in China. METHODS:Structure-conduct-performance(SCP)analysis paradigm from Harvard was used for in-depth study of market structure,business conduct and business performance in China since 2010. RESULTS:Since 2010, drug distribution industry in China had shown the scale of decline in the growth rate,low market concentration,increased barriers to entry,the leading of state-owned capital,etc. Though corporate mergers and acquisitions and public financing expanded the scale,management information,third-party logistics,Internet+and pharmacy alliance business model flourished,the industry op-erating performance was poor,state-owned enterprises showed poor performance. CONCLUSIONS:The transformation and upgrad-ing of the industry business model should be promoted by targetedly accelerating the supply-side structural reforms in the drug distri-bution industry,encouraging corporate finance mergers,breaking local protectionism,developing cooperative pharmacies and phar-maceutical third-party logistics alliances and leveraging the Internet.

Objective:To evaluate the effects of different denture cleaners on the discoloration of heat-cured denture base resin and artificial teeth.Methods:40 same specifications of the heat-curing denture base resin and 40 artificial central incisors were immerced in an acombination stain of coffee,tea and soy sauce for 4 weeks.Then specimens and artificial teeth were randomly distributed into 4 groups and soaked in Polident,Steradent,0.5％ sodium hypochlorite solution and distilled water for 4 hours respectivelly(n =10).Color differences(△E) were measured by using a colorimeter and a denture spectrophotometer before and after staining,and after cleaning.Results:Before or after staining there was no difference of △E among the groups of denture base risn or artificial teeth(P ＞ 0.05).After cleaning the denture base resin and the artificial teeth in the group of 0.5％ sodium hypochlorite solution presented higher △E than the other groups(P ＜ 0.05),in group of distilled water presented lower △E than the other groups(P ＜ 0.05).No significant difference was found between Polident group and Steradent group(P ＞0.05).The △E of the denture base resin and artificial teeth.in distilled water group before staining and after cleaning were the highest among the groups(P ＜0.05).Conclusion:0.5％ sodium hypochlorite solution,Polident and Steradent are effective in removing the discoloration from the heat-cured acrylic resin and artificial teeth.0.5％ sodium hypochlorite solution is the most effective,Polident and Steradent are the similar.