Objective:To study the mechanisms of imipenem resistance in Pseudomonas aeruginosa.Methods:Drug resistance of 69 isolates of imipenem-resistant Pseudomonas aeruginosa(IRPA)were tested by Kirby-Bauer disk diffusion method;IMP and VIM genes of metallo-?-lactamases,and outer membrane protein D2(OprD2)gene of IRPA were detected and analyzed by PCR method.Results: All 69 isolates were multidrug resistant,and the sensitivity rates of AMK,CFS and FEP were highe.The positive rates for IMP gene and VIM gene were 2.9%(2/69)and 5.8%(4/69),respectively.46 of 69(66.7%)isolates presented with deletion for OprD2 gene. Conclusion:The drug resistance of IRPA is a serious issue.The deletion mutation of OprD2 gene is one of important mechanisms of imipenem resistance in these tested P.aeruginosa isolates.

Objective:To investigate the drug resistance and genotypes of extended-spectrum ?-lactamase(ESBL)-producing Enterobacteriaceae bacteria in our hospital.Methods:257 strains of Enterobacteriaceae bacteria were isolated from clinical specimens in our hospital from Sept.2002 to Oct.2003.Sixty-three strains of ESBLs-producing isolates were detected by phenotypic confirmatory test according to NCCLS M100-S9.The susceptibility test of them to the antibiotics were detected with Bio-Merieux ATB G-5.The SHV-type,TEM-type,CTX-M-type encoding genes were amplified by PCR.Results:The resistant rates of the 63 strains to IMP,MERO,CXT,FEP,CAZ,AKN,CTX and CIP were 1.6%,1.6%,38.1%,39.7%,46.0%,55.6%,63.5% and 95.2%,repectively.The rates of Enterobacteriaceae bacteria carrying SHV-type,TEM-type,CTX-M-type ESBLs were 84.1%,47.6% and 25.4%,repectively.Conclusion:Multidrug resistance of the ESBLs-producing strains in our hospital is obvious.IMP and MERO are still the best choices for treatment of the infections caused by ESBLs-producing bacteria.Most of the ESBLs-producing strains carry SHV-type.CTX-M-type ?-lactamase exists prevalently in our hospital.

BACKGROUND: Beta-adrenergic activation can enhance signal-transduction pathway of endothelial nitric oxide (NO). Vascular endothelial NO production in response to β -adrenergic activation is important in the normal control of vessel tone by the sympatheadrenal system. Previous trials have demonstrated that endothelial nitric oxide synthase (eNOS) activated by isoprenaline, β -adrenergic agonist, may be correlated with phosphorylation of eNOS. OBJECTIVE: To investigate the possible protein kinase involved in the signal transduction of the eNOS activation by β -adrenoceptor (β AR) stimulation in human vascular endothelium. DESIGN: Comparative observation. SETTING: Department of Geriatrics, First Affiliated Hospital of Zhengzhou University. MATERIALS: The experiment was performed at the Open Key Clinic Medical Experimental Laboratory of University of Henan Province between September 2006 and June 2007. Fresh umbilical cords were obtained following delivery of healthy babies to healthy normotensive mothers, either by vaginal delivery or by elective Caesarean section. The written informed consent was obtained from all donors. Approval was granted by the Affiliated Hospital of Zhengzhou University. Isoprenaline, H-89, Wortmannin, [3H]-L-arginine were from Sigma, USA. METHODS: Blank control group, H-89 group (protein kinase inhibitor), Wortmannin group (phosphatidylinositol 3-kinase inhibitor) and H-89+Wortmannin group were set up, and isoprenaline subgroup and blank subgroup were subdivided with 3 tubes in each group. Human umbilical vein endothelial cells (HUVECs) were cultured with H-89 and Wortmannin, separately for 10 minutes, then agonist isoprenaline or vehicle was added and the incubation continued for another 30 minutes, eNOS activity was determined by the conversion of [3H]-L-arginine to [3H]-L-citrulline. The results were corrected by protein concentration in the corresponding cellular extracts. MAIN OUTCOME MEASURES: Changes in eNOS activity of each group. RESULTS: ①Basal [3H]-L-citrulline production was (3 085.62±272.72) mBq per 1 μ g protein, lsoprenaline increased [3H]-L-citrulline formation by (30.72 ± 3.91 )% compared with the control group (P < 0.001 ). H-89 or Wortmannin alone did not alter eNOS activity [(0.44± 1.00)%, (0.36±1.47)%, P > 0.051. ②The increase of eNOS activity by isoprenaline wassignificantly inhibited by pretreatment of H-89 and Wortmannin [(4.73±2.19)%, (17.35±3.72)%, P < 0.001]. ③The inhibition of protein kinase and phosphatidylinositol 3-kinase to isoprenaline-induced increase in eNOS activity [(4.92± 0.99)%] was similar to protein kinase alone, but not in an additive effect (P > 0.05). CONCLUSION: Protein kinase and phosphatidylinositol 3-kinase are involved in the signal transduction of β- adrenoceptors mediated eNOS activation.

Objective To study the therapeutical effects and mechanisms of quercetin on hepatic fibrosis in schistosome-infected mice and compare the effects with praziquantel. Methods Eighty mice were divided into four groups: among them three groups were infected by Schistosoma japonica. After 8 weeks, one group was treated with quercetin 30 mg/(kg?d) for 8 weeks, one group was treated with praziquantel 500 mg/(kg?d) for 2 d and the other was taken as model group without any treatment. The fourth group was taken as normal group. HE staining, RT-PCR, and immunohistochemical technique were used to observe the expression of hepatic c-fos and c-jun mRNA, and the changes of hepatic TGF-?1, type Ⅰ, and type Ⅲ collagen in mice infected by S. japonica before and after treatments. Results Quercetin obviously relieved the degree of hepatic fibrosis, significantly reduced the expression of c-fos, c-jun mRNA, TGF-?1, type Ⅰ, and type Ⅲ collagen compared to the model group (P

Objective To observe the effect of depside salt from Salvia Miltiorrhiza on platelet endothelial nitric oxide synthase(eNOS) activity in health adults.Methods Peripheral venous blood was collected,platelets were isolated with gel-filtration chromatography and incubated with eNOS agonist histamine,eNOS inhibitor L-NAME and different concentrations of depside salt from Salvia Miltiorrhiza(0.1,1,10,100,1000 mg/L) for 30 minutes,then eNOS activity was measured as formation of 3H-L-citrulline from 3H-L-arginine.Results(1)Platelet eNOS activity was significantly inhibited after incubated platelets with L-NAME and increased after incubated with histamine(P

Caveolae, specialized vesicular invaginations of the plasma membrane ,have attracted increasing attentions to those who are studing siginal transduction .Many proteins involved in signal transduction have been found enriched in these microdomains.Caveolins,as marker proteins of caveolae,form a scaffold onto which many classes of signaling molecules can assemble at steady state or after ligand-induced activiton .In addition to concentrating these signal transducers within a distinct region of the plasma membrane ,caveolin binding may functionally regulate the activation state of caveolae-associated signaling molecules.Thus,an emerging notion is that caveolae are signaling processing centers which orchestrate signaling events at the cell surface that influence cell function .

Objective: To investigate the expression of ER, PR, HER-2, PCNA and P53 in breast cancer patients in Shanghai and the relevant clinical significance. Methods: Expressions of ER, PR, HER-2, PCNA and P53 in the breast cancer tissues of 544 patients in Shanghai were detected by immunohistochemistry methods. Statistical analysis was applied to analyze the relationship of these immunohistochemical indices with the clinicopathological features of breast cancer. Results: The positive rates of ER, PR, HER-2, PCNA and P53 in the breast cancer tissues of 544 patients were 62.2%, 57.2%, 15.1%, 82.6% and 58.5%, respectively. The expressions of ER, PCNA and P53 were correlated with the tumor size (P<0.05, P<0.01). The expressions of HER-2 and PCNA were correlated with axillary lymphatic metastasis (P<0.05, P<0.01). ER expression was positively correlated with PR expression(r=0.452, P=0.000) and PR expression was positively correlated with P53 expression (r=0.520, P=0.03). The 123 (22.6%) patients with triple-negative breast cancer (TNBC) had a higher axillary lymphatic positive rate than patients with non-TNBC (P<0.01). Co-expression of HER-2 with PCNA and co-expression of HER-2 with P53 were positively correlated with lymphatic metastasis (P<0.05). Conclusion: Population aging has a influence on the immunohistochemical characteristics of breast cancer patients patients in Shanghai. Combined examination of ER, PR, HER-2, PCNA and P53 is of clinical significance in the diagnosis, treatment, and prognosis prediction of breast cancer patients.

Objective To compare the efficiency of detecting YMDD mutations by direct DNA sequencing and real time fluerescence PCR, and to explore the significance of the mutations of drug-resistance gene other than YMDD mutation. Methods 92 serum samples from 89 patients with chronic hepatitis B were collected and all the samples were detected by real-time PCR for YMDD mutation. HBV DNA was extracted from serum and was amplified by nest PCR to achieve HBV P gene RT region sequence. The PCR products were sequenced at both directions, and the sequencing results were contrasted through NTI program. The other 11 known drug-resistance mutation sites at the HBV RT region were also analyzed. Results Among the 37 samples with no YMDD mutation detected by real-time PCR, 33 samples were with M204M (without mutation), 1 sample with M204I and 3 samples with M204V by direct sequencing. Mutation and wild-type standard sequences were all coexisted in the 4 positive samples. There were 7 samples detected with ADV resistant mutation, accounting for 18.9% (7/37). Among the 55 samples with YMDD mutation detected by real-time PCR, 52 samples were detected by DNA sequencing, the accordance rate was 94.5% (52/55); 5 samples with ADV or ETV resistant mutation were detected, accounting for 9.1% (5/55). Conclusions Direct DNA sequencing is a high sensitive, repeatable method to detect drug-resistance mutation at RT region of HBV P gene. The result is well consistent with that attained by real-time PCR. Direct DNA sequencing can also detect various drug-resistance mutations as well as YMDD mutation, which is helpful to generally understand the nucleoside analogue resistant mutation and adopt more reasonable therapy projects against HBV.

Atrial fibrillation ( AF) is the most common sustained arrhythmia in clinical practice and it is associated with an in-creased thromboembolism risk , due mainly to embolism from the left atrial appendage ( LAA) .Percutaneous left atrial appendage clo-sure ( PLAAC) provides a valid alternative to oral anticoagulation ( OAC) mainly in patients who cannot tolerate this therapy due to a high bleeding risk .Recent studies showed PLAAC can substantially reduce stroke incidence .This article reviews the safety and efficacy of PLAAC preventing thromboembolism by retrospectively analyzing related studies of PLAAC .

Objectives:To investigate the relationship between coronoid process hyperplasia(CPH)and temporomandibular joint ankylosis(TMJA) and to analyze its pathologic mechanism and clinical meaning.Methods:28 patients with TMJA from 1984 to 2004 were retrospectively studied.The length of coronoid process and the mouth-opening degree were measured on their depicting map of panoramic radiographs.106 subjects with normal TMJ were enrolled as the controls.The relationship between CPH and case history of TMJA was statistically analysed.Results:Coronoid process in TMJA subjects was longer than that in the controls(P