Objective To investigate the effect of ovariectomy and estrogen on secretion function and number of pancreatic islet beta cell in low-dose streptozotocin-induced diabetic rats. Methods Thirty female SD rats were randomly divided into five groups: normal control(NC) group, streptozotocin(STZ) group, ovariectomized(OVX) group, OVX + STZ(OS) group and OVX+STZ+estradiol(OSE) group. OVX, OS and OSE groups underwent ovariectomy, while NC and STZ groups underwent just sham operation. After surgery, OSE group was treated subcutaneously with estradiol 0.2 mg/kg twice weekly. At the end of 3 weeks, STZ, OS and OSE groups were induced by a single intraperitoneal injection of 40 mg/kg STZ. Then eight days later, plasma glucose and insulin levels were tested. The insulin protein, the average beta cell area and the relative beta cell mass were tested by streptavidin peroxidase conjugation method (SP). The quantification of beta cell apoptosis was performed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). The expressions of proliferating cell nuclear antigen(PCNA) protein, Bax and Bcl-2 were tested. Results With the administration of low-dose STZ, the plasma glucose was significantly higher and the insulin secretion curve after glucose loading, △I30/△G30 and modified beta cell function index(MBCI) were lower in OVX group than in other groups(all P<0.05). At the same time, the insulin protein, the relative beta cell mass and the beta cell area were dramatically decreased(all P<0.05). The beta cell apoptotic index was increased (t = 2.957, P< 0.05), the expression ratio of Bcl-2/Bax was decreased (0.41±0.03 vs. 0.76±0.05, P<0.05). Estrogen replacement therapy could obviously inhibit these changes. Compared with OS group, glucose disturbances and insulin secretion were improved dramatically in OSE group(all P<0.05); the insulin content, the relative beta cell mass and the average beta cell area were all enhanced (all P<0.05); the beta cell apoptotic rate was decreased(t =2.482, P<0.05), and the expression tatio of Bcl-2/Bax was increased (0.71±0.05 vs. 0.41±0.03, P<0.05). Conclusions The ovx rats are significantly more susceptible to low-dose STZ toxicity than in control rats. Under the effect of STZ, the ability of insulin secretion of beta cell is obviously decreased, while apoptosis is increased, which induces a higher glucose level and a lower insulin secretion. Administration of estrogen may protect OVX rats from the metabolic disturbances.

Objective To compare the myocardial damage in patients with severe valvular heart disease undergoing open heart surgery under propofol and sevoflurane combined anesthesia.Methods Thirty-two patients with severe heart valvular disease undergoing open heart surgery were randomized into 3 groups:midazolam group (group M,n =8),propofol group (group P,n =12) and sevoflurane group (group S,n =12).Midazolam 1-5 mg,vecuronium 0.15 mg/kg and fentanyl 10-20 μg/kg were injected intravenously in group M.Propofol 1-2 mg/kg,vecuronium 0.15 mg/kg and fentanyl 10 μg/kg were injected intravenously in group P.In group S,the patients inhaled sevoflurane until the eyelash reflex disappeared,the end-tidal concentration of sevoflurane was 0.5 ％-2.0％,and vecuronium 0.15 mg/kg and fentanyl 10μg/kg were injected intravenously.The patients were mechanically ventilated after tracheal intubation.Anesthesia was maintained with iv infusion of midazolam 0.1 mg· kg-1 · h-1,fentanyl 0.2 μg· kg-1 · min-1,and vecuronium 0.12 mg· kg-1 · h-1 in group M,with iv infusion of propofol 150 μg· kg-1 · min-1 and fentanyl μg· kg-1 · min-1 in group P,or with inhalation of 0.5％-2.0％sevoflurane in group S.CPB was established routinely.The concentration of sevoflurane was 0.5 ％-1.0％ during CPB.Venous blood samples were collected before anesthesia (T1),at 20 min and 2 h after aortic unclamping (T2,3),and at 24 h after operation (T4) for determination of the levels of plasma lactic dehydrogenase (LDH),creatine kinase (CK),creatine kinase MB (CK-MB),cardiac troponin Ⅰ (cTnⅠ),superoxide dismutase (SOD)and tumor necrosis factor (TNF)-α.Myocardial tissues were taken at T2 for determination of heme oxygenase-1 (HO-1) expression and for examination of the myocardial ultrastructure.Results Compared with group M,the levels of plasma LDH,CK-MB,and CK were significantly decreased at T2-4,the levels of plasma SOD and cTnⅠ were significantly increased at T2,3,and the expression of HO-1 was up-regulated at T2 in groups P and S,and the levels of plasma TNF-α were significantly decreased at T2-4 in group P and at T2,3 in group S (P ＜ 0.05).The pathologic changes induced by I/R were less severe in groups P and S than in group M.Conclusion Both propofol and sevoflurane can attenuate the myocardial damage in patients with severe valvular heart disease undergoing open heart surgery and the effects are comparable.

Objective To explore the effects of multidrug resistance-associated protein 4 (MRP4) inhibition on pulmonary vascular endothelial barrier dysfunction in septic rats.Methods Sixty Sprague Dawley rats were randomly (random number) divided into three groups:sham-operated group,sepsis group,and sepsis plus MRP4 inhibitor treatment group,with 20 rats in each group.Sepsis was induced by cecal ligation and puncture.MRP4 inhibitor MK571 (20 mg/kg) was administrated by intraperitoneal injection 30 minutes before induction of sepsis.Twenty-four later,serum interlukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) levels were measured by enzyme-linked immunosorbent assay.Lung injury was assessed by histopathological examination.Lung vascular permeability was evaluated by quantitation of Evans blue dye extravasation from vascular space to lung parenchyma.Results Compared with sham group,serum IL-6 and TNF-α levels were significantly higher in sepsis group.In addition,lung injury and lung vascular permeability were elevated in sepsis group compared to sham group.Importantly,MRP4 inhibitor treatment significantly decreased serum IL-6 and TNF-α levels,improved lung injury and reduced lung vascular permeability in septic rats.Conclusions Inhibition of MRP4 protects against pulmonary vascular endothelial barrier dysfunction in septic rats.

Objective By investigating the actualities of career development potential of eight-year program medical students, to explore a direction of training mode innovation aiming to improve career development potential. Methods Eight-year program medical graduates, their tutors, and di-rectors of their clinical department in a university hospital were the subjects of the current study. Questionnaire method was applied to evaluate professional competence including clinical skills, re-search capabilities and integrative ability . Anonymous questionnaires were dispensed to eight-year program medical graduates for self-evaluation. Distinct anonymous questionnaires were dispensed to tutors directors for evaluation. Traditional doctoral graduates (professional degree or academic degree) were set as standard for comparison of specific ability of eight-year program medical students. Results 74 out of 85 (87%) questionnaires for Eight-year program medical graduates were available. 53 out of 63 (84%) questionnaires for tutors were available. 21 out of 26 (81%) questionnaires for directors of clinical departments were available. In clinical capabilities, according to 43 percent (32 persons) of the eight-year MD graduates' self-assessment and the evaluation of 94%(50 persons) mentors and 81%(17 people) department directors, eight-year program medical graduates were regarded as lower-skilled clinicians compared with doctoral graduates with professional degree . Eight-year program medical graduates were also considered with worse research capabilities than doctoral graduates with profes-sional degree by themselves (76%, n=56), their tutors (91%, n=48), and their department directors (86%, n=18). Conclusions The survey shows that to some extent, the current eight-year clinical doctoral graduates lack of career development potential, reflecting the current training mode cannot lead to the given training goals. We suggest that both clinical skills and research capabilities should be enhanced to make sure that eight-year program medical graduates deserve the title of academic physicianorphysician scientists.

Background:The incidence of ulcerative colitis (UC)in developed countries is higher than that in developing countries,which may be related with westernized lifestyle,especially high animal protein and low complex carbohydrate diet. With the increased high fat and meat intake,synthesis and secretion of bile acid in liver is also increased,which may have an impact on the occurrence of UC. Aims:To investigate the expressions of farnesoid X receptor (FXR)and G protein-coupled bile acid receptor 5 (TGR5)in patients with UC. Methods:Thirty patients with active UC from January 2013 to June 2016 at the Affiliated Jiangning Hospital of Nanjing Medical University were enrolled,and 30 healthy subjects were served as controls. Expressions of FXR and TGR5 were determined by immunohistochemistry. Results:Compared with control group,expression of FXR was significantly decreased in UC patients (4. 63 ± 2. 07 vs. 6. 91 ± 2. 62,P =0. 00),however,no significant difference in expression of TGR5 was found between the two groups (6. 70 ± 2. 90 vs. 6. 11 ± 2. 44,P = 0. 40). Expression of FXR was significantly increased in right hemicolon colitis than in left hemicolon colitis (P < 0. 05). Conclusions:There is a significant decrease in FXR in active UC patients,indicating that FXR may have some role in the pathogenesis of UC,however,TGR5 may have no obvious effect in the pathogenesis of UC.

Objective To investigate the effect of multidrug resistance protein 4 (MRP4) overexpression on lipopolysaccharide (LPS)-induced vascular endothelial hyperpermeability of rat pulmonary micro-vascular endothelial cells (PMVECs) and its molecule mechanism. Methods Three to six passages of PMVECs were cultured in vitro, and they were divided into three groups: the cells in LPS group were only challenged by LPS 10 μg/mL after being cultured in serum-free medium for 24 hours; the cells in Ad-shRNA and Ad-MRP4 groups were infected with the empty virus control or recombinant adenovirus expressing MRP4 for 2 hours, and then were cultured in serum-free medium for 24 hours followed by stimulation of LPS 10 μg/mL. Endothelial permeability was assayed by the Transwell chamber models at 2, 6, 12, and 24 hours after LPS stimulation. Intracellular cyclic adenosine monophosphate (cAMP) levels were detected by enzyme-linked immunosorbent assay (ELISA). The morphological characteristics and distribution of F-actin was determined by laser confocal fluorescence microscope. The protein expressions of MRP4,β-catenin, vascular endothelium-cadherin (VE-cad) and ZO-1 were measured by Western Blot. Results ① After LPS stimulation, endothelium permeability and intracellular cAMP levels in PMVECs were significantly increased, peaked at 12 hours, and then decreased after 24 hours. Compared with LPS group and Ad-shRNA group, PMVECs of Ad-MRP4 group were exhibited a significant increase in endothelial permeability [12-hour permeability (A value):1.88±0.06 vs. 1.12±0.17, 1.10±0.18] and a significant decrease in intracellular cAMP level [12-hour cAMP (μg/L):2.39±0.02 vs. 2.97±0.01, 3.00±0.02, all P < 0.05]. There was no significant difference in endothelium permeability and intracellular cAMP levels at all time points between the LPS group and the Ad-shRNA group (all P > 0.05).② Under laser confocal fluorescence microscope, after LPS stimulation, the stress fiber formation was induced in three groups. But there were pronounced irregular aggregation of fiber in PMVECs of Ad-MRP4 group. ③ Furthermore, compared with LPS group and Ad-shRNA group, protein expression of MRP4 in Ad-MRP4 group was dramatically increased (gray value: 0.76±0.03 vs. 0.44±0.02, 0.43±0.02, both P < 0.05), and the protein expressions of β-catenin, VE-cad, and ZO-1 were significantly decreased [β-catenin (gray value): 0.14±0.03 vs. 0.23±0.04, 0.23±0.03);VE-cad (gray value): 0.21±0.01 vs. 0.34±0.02, 0.35±0.04; ZO-1 (gray value): 0.14±0.02 vs. 0.37±0.06, 0.33±0.07, all P < 0.05]. There was no significant difference in all protein expressions between the LPS group and Ad-shRNA group (all P > 0.05). Conclusion MRP4 overexpression can decrease intracellular cAMP levels, reduce intercellular junction protein expression, and then exaggerate LPS-induced vascular endothelial hyperpermeability.

Objective To investigate the protective effect of multidrug resistant associated protein 4 (MRP4) inhibitor on rats with sepsis-induced acute lung injury (ALI). Methods Sixty Sprague-Dawley (SD) rats were randomly divided into sham group, sepsis group and MRP4 inhibitor MK571 treatment group, with 20 rats in each group. Sepsis model was reproduced by cecal ligation and puncture operation (CLP), and the rats in sham group were only received celiotomy without ligation and puncture. Rats in MK571 treatment group were intraperitoneally injected with MRP4 inhibitor MK571 (20 mg/kg) 30 minutes before model reproduction, while rates in sham group and sepsis group were given the same amount of normal saline. Twenty-four hours later, the femoral artery blood of mice was collected, and arterial blood gas analysis was measured. Serum tumor necrosis-α (TNF-α) was determined by enzyme-linked immunosorbent assay (ELISA). The lung tissues were collected, and the wet/dry weight ratio (W/D) was calculated. The expression of MRP4 protein in lung tissue was determined by Western Blot. Results Compared with sham group, arterial blood pH value and arterial partial pressure of oxygen (PaO2) were significantly lowered [pH value: 7.18±0.03 vs. 7.40±0.03; PaO2 (mmHg, 1 mmHg = 0.133 kPa): 63.15±6.24 vs. 98.05±2.58], while arterial partial pressure of carbon dioxide (PaCO2) was dramatically higher in the sepsis group (mmHg: 56.60±8.30 vs. 37.85±3.18), serum TNF-α level in the sepsis group was significantly increased (ng/L: 146.24±19.99 vs. 25.77±9.83), the W/D ratio of lung tissue was significantly increased (7.75±0.47 vs. 4.09±0.58), and the expression of MRP4 protein was up-regulated in the sepsis group (gray value: 0.153±0.006 vs. 0.087±0.005, all P < 0.05). Compared with the sepsis group, arterial blood pH value (7.30±0.02 vs. 7.18±0.03) and PaO2 (mmHg: 80.30±5.34 vs. 63.15±6.24) were significantly elevated in the MK571 treatment group, while PaCO2 was dramatically decreased (mmHg: 29.25±3.24 vs. 56.60±8.30), the serum level of TNF-α was significantly decreased (ng/L: 97.96±16.72 vs. 146.24±19.99), the W/D ratio of lung tissue was significantly reduced (5.89±0.51 vs. 7.75±0.47), and MRP4 protein expression was significantly down-regulated (gray value: 0.124±0.006 vs. 0.153±0.006, all P < 0.05). Conclusion MRP4 inhibitor may improve lung function in rats with sepsis-induced ALI by down-regulating MRP4 protein expression and reducing levels of inflammatory cytokines, which exerts protective effect on ALI.

Objective To introduce a new modified percutaneous dilational tracheostomy and compare the application effect of percutaneous dilational tracheostomy with modified percutaneous dilational tracheostomy in the treatment of critically ill patients. Methods A total of 60 critically ill patients undergoing tracheotomy were selected , and they were randomly divided into two groups according to the methods of tracheotomy. Sex, age, weight, body mass index, acute physiology and chronic health evaluation, operation time, incision size, intraoperative blood loss, incision healing time, incidences of complications after operation were compared between the two groups. Results There were not statistically significant differences of in sex, age, weight, body mass index, and acute physiology and chronic health evaluation between percutaneous dilational tracheostomy group and modified percutaneous dilational tracheostomy group (P>0.05). Operation time, incision size and intraoperative blood loss of modified percutaneous dilational tracheostomy group was statistically significantly shorter than that of percutaneous dilational tracheostomy group [(5.80 ± 1.19) min vs. (7.65 ± 1.05) min, (8.33 ± 3.30) ml vs. (11.33 ± 4.34) ml, (1.08 ± 2.96) cm vs. (1.27 ± 2.54) cm] (P<0.05). The incision healing time and incidence of complications after operation of percutaneous dilational tracheostomy group had no statistical significance compared with modified percutaneous dilational tracheostomy group (P>0.05). Conclusions The modified percutaneous dilational tracheostomy can save operation time, and reduce intraoperative blood loss, so it can be widely used.

17β-estradiol(E2), progesterone (P) and testosterone (T) were investigated for their effects on the proliferation and differentiation of primary rat calvarial osteoblasts in vitro. Rat calvarial osteoblasts were cultured with l0-10 mol/L E2, 10-9-10-6 mol/L P and l0-10 mol/L T for 20days. Cell proliferation was determined by 3H-thymidine incorporation and cell counting. Cell differentiation was examined by measuring alkaline phosphatase (ALP) activity, osteocalcin gene expression and production, bone nodule formation in different periods of culture. Our results showed that no effect of three sex hormones was observed on cell proliferation, but, the responses of cell differentiation to the hormones were more or less different. Among these three hormones used in this study, P appeared to have multi-stimulating effect on cell differentiation. Effect of T seemed not so significant as that of P on cell differentiation. Although ALP activity and osteocalcin production were increased significantly by T, it had slight effect on osteocalcin mRNA and bone nodule formation. Besides, E2 did not demonstrate any effect on cell differentiation. It is concluded that the proliferation of rat calvarial osteoblasts was independent of the presence of sex hormones. However, the differentiation of these cells were stimulated in different levels and to different extent either by P or T. P appeared to be a multi-stimulator on differentiation of such cells.

17β-estradiol(E2), progesterone (P) and testosterone (T) were investigated for their effects on the proliferation and differentiation of primary rat calvarial osteoblasts in vitro. Rat calvarial osteoblasts were cultured with l0-10 mol/L E2, 10-9-10-6 mol/L P and l0-10 mol/L T for 20days. Cell proliferation was determined by 3H-thymidine incorporation and cell counting. Cell differentiation was examined by measuring alkaline phosphatase (ALP) activity, osteocalcin gene expression and production, bone nodule formation in different periods of culture. Our results showed that no effect of three sex hormones was observed on cell proliferation, but, the responses of cell differentiation to the hormones were more or less different. Among these three hormones used in this study, P appeared to have multi-stimulating effect on cell differentiation. Effect of T seemed not so significant as that of P on cell differentiation. Although ALP activity and osteocalcin production were increased significantly by T, it had slight effect on osteocalcin mRNA and bone nodule formation. Besides, E2 did not demonstrate any effect on cell differentiation. It is concluded that the proliferation of rat calvarial osteoblasts was independent of the presence of sex hormones. However, the differentiation of these cells were stimulated in different levels and to different extent either by P or T. P appeared to be a multi-stimulator on differentiation of such cells.