OBJECTIVE To explore production of ?-lactamase induced by antibiotics in Pseudomonas aeruginosa biofilm and planktonic bacteria.METHODS In vitro models of P.aeruginosa biofilm were built up.The planktonic bacteria and P.aeruginosa biofilms were exposed to different concentrations of imipenem and ceftazidime.The quantitative analysis of ?-lactamase was undertaken.The class of ?-lactamase was verified by modified cefoxitin three-dimensional test.RESULTS Both P.aeruginosa biofilm and planktonic bacteria showed significant ?-lactamase activity in the presence of antibiotics.The maximal ?-lactamase activities of both were significantly different with the statistic method of test(P

Objective To explore the effects of TNF-? on the function of Leydig cells, in order to elucidate the possible mechanisms involved. Methods Highly pure primary Leydig cells were obtained by Percoll discontinuous density gradient method. HE stain was used to observe the morphology of the cultured cells. The Leydig cells were treated with different doses of rat TNF-? (0.1, 1, 10, 100 ng/ml) for 48h, and then the supernatants of culture medium were collected every 24 hours at the 1st, 2nd, 3rd and 4th day. The testosterone level in the supernatant was measured by radioimmunoassay. The proliferation and TNF-?-induced apoptosis of Leydig cells were examined by MTT assay, flow cytometry (FCM) as well as acridine orange (AO) stain. Results The purity of Leydig cells was 70%-80% after purification with Percoll discontinuous density gradient method. The Leydig cells were rich in cytoplasm, which contained some secretory granules and round nucleus. After TNF-? treatment in different concentrations (0.1, 1, 10, 100ng/ml) for 24h, the inhibition rates of TNF-? on testosterone secretion of Leydig cells were 22.0%, 35.0%, 53.0% and 74.8%, respectively, and the decrease showed a time-dependent manner, but no statistically significant difference was found in each group at every time point except for 100ng/ml group. High concentration of TNF-? (10 and 100 ng/ml) could inhibit the proliferation and promote apoptosis of Laydig cells. Compared to control group, the inhibition rate and apoptosis rate in 10ng/ml and 100ng/ml group showed significant difference (respectively 38.4%?4.1%, 76.4%?8.7% and 13.2%?1.1%, 26.4%?5.8%). In addition, significant apoptosis could be seen in the high concentration groups as shown with AO staining. Conclusion The present study suggests that TNF-? can inhibit the basal testosterone secretion of Leydig cells, which might be related to the inhibition and apopotosis-induced effects of high concentration of TNF-?.

Objective To evaluate the sensitivity and specificity of DNA micro-array in early detection of infectious pathogens on burn wounds,including 9 species of potential infectious pathogens namely Staphylococcus aureus,Escherichia coli and Pseudomonas aeruginosa,etc.Methods Serial dilutions of each targeted bacteria in saline were examined with VITEK automated microbial test systems(routine methods) as well as by DNA micro-array to compare the sensitivity between these two methods.Sixty-two strains of infectious pathogens collected from burn wounds,were identified by routine methods,and they were also subjected to DNA micro-array examination to determine coincidence.One hundred and three examinations of smear specimens collected from fresh burn wounds were performed with both methods synchronously.The difference in positive result of identification of bacteria between routine method and micro-array technology in sensitivity and specificity was compared.Results The identification of bacteria by micro-array was more convenient and rapid than that by routine method.A 10 to 100 fold higher sensitivity was found in bacterial identification by DNA micro-array than by routine methods.The positive and negative coincidence of bacterial identification was 100% between these two methods.All the strains found by the routine methods were successfully identified by DNA micro-array.In a few instances,more strains of bacteria were detected with micro-anay method than rowtine method.Conclusion The extremely high coincidence and sensitivity of micro-array method with the routine method was confirmed.The detection of bacteria from burn wounds and other contaminated or infected wounds using micro-array method has a bright prospect though some improvements are still necessary.

Objective To establish a method of GS-MS for determination of polychlorinated biphenyls (PCBs) in human cerumen. Methods The PCBs in cerumen samples was separated by n-hexane extraction, liquid-liquid extraction separation and column chromatography purification, then was analyzed quantitatively by gas chromatography and affirmed qualitatively by mass spectroscopy. Results The detection limit, average recovery rate and precision of this method were 0.15 ?g/g fat, 92.1% and 3.0%-4.6% (n=12) respectively. The contents of PCBs in 90 cerumen samples collected in polluted and control areas were detected. The levels(0.00-18.42 ?g/g fat) of PCBs in cerumen collected in polluted area were significantly higher than that in the control area(P

Objective: To study the effect of processing on the content of organic acids in the different processed products of Fructus Crataegi. Methods: The determinations of the crude Fructus Crataegi, five kinds of different processed products and newly fried product were carried out by titration. Results: There were significant differences in organic acid contents among different processed products and the crude. Conclusion: Different processed method and temperature can effect the contents of organic acid on Fructus crataegi.

The sera of 206 cases with hydatid disease diagnosed by B-ultrasound and X-ray in survey scene had been examined by Dot-ELISA and IHA with Qinghai cystic hydatid antigen, ELISA With Xingjiang cystic hydatid antigen and Em18-EliB with alveolar hydatid antigen. The results showed that the sero-positive rates were 90. 37％ and 91.98％ in these cases with cystic hydatid disease by Dot EliSA and IHA with Qinghai cystic hydatid antigen respectively. The sero-positive rate was 75. 94％ in same cases by ELISA with Xingjiang cystic hydatid antigen. The sero-positive rateswere 77.27％ 81. 82％ and 65. 91 ％ in those cases with the whole calcific cystic hydatid disease by above three methods respectively, and the sero-positive rates were lower in whole calcific cystic hydatid than that in other cystic hydatid disease. The sero-negative cases belonged to cystic hydatid disease which located in lungs of livers alone. The results by EM18-ELIB with alveolar hydatid antigen showed that the sero-positive rates were 73. 68％ and 5. 88％ in those cases with alveolar hydatid disease and with cystic hydatid disease diagnosed by B-ultrasound and X-ray respectively,and the sero-positive rate was 15.91 ％ in whole calcific cystic hydatid disease. The ratio of the number of positive seras to that of negative seras was 1 to 7 approximately. The value and mean of different serological methods in diagnosis and judge diagnosis for cystic and alveolar hydatid disease had been discussed.

Objective To investigate the expression of Ezrin protein and c-met in esophageal squamous cell carcinoma, their significance in the progress of esophageal squamous cell carcinoma development and metastasis. Methods The expression of Ezrin protein and c-met in 50 patients with esophageal squamous cell carcinoma was studied using immunohistochemical (SP) method. The correlation of each score according to the intensity and percentage of labeled cells or intercellular substance with relevant clinical data was statistically analyzed. Results In normal esophageal squamous epithelium, the positive expression of Ezrin protein was 34 %, the positive expression of c-met was 8.0 %. In esophageal squamous cell carcinoma, the positive expression of Ezrin protein was 76.0 %, the positive expression of c-met was 58.0 %. The expression of Ezrin protein had close relation to depth of invasion and lymph node metastasis(P < 0.05). The positive rate of c-met protein expression in lymph node metastasis was obviously higher than those without lymph node metasis (P <0.05). The expressinn of Ezrin protein in c-met positive eases was obviously higher than those of c-met negative cases(P <0.05). Conclusion The test of Ezrin protein and c-met may have significant prognostic value for assessing the degree of malignancy and potential lymph node metastasis probability of esophageal squamous cell carcinoma. Ezrin protein may be a target to evaluate the tumor prognosis.

Objective To observe the changes in cerebral microcirculation after subarachnoid hemorrhage(SAH) and to study its correlation with cerebral vasospasm(CVS).Methods Eighty-five SAH patients and 35 controls,enrolled in this study as perspective study subjects,were divided into SAH group and control group,CVS group and non-CVS group(nCVS),symptomatic CVS(sCVS) group and asymptomatic CVS(asCVS) group.All the subjects underwent CT perfusion(CTP) and the associated parameters,including cerebral blood flow(CBF),cerebral blood volume(CBV) and mean transit time(MTT),were recorded for final analysis.Results Compared to the control group,the CBF and MTT were significantly changed in SAH group(P

In recent five years,brain imaging studies suggested that internet addicts' neural pathway have abnormalities in reward circuits,executive control system,and decision-making system when they are in resting state or induced state.For internet addicts,in the aspect of reward circuits,they showed decreased metabolism level when undergoing a resting-state fMRI scan,and enhanced reward sensitivity as well as decreased loss sensitivity when functioning.In the aspect of executive control system,the related brain areas were associated with reduced white matter integrity and disrupted functional comnectivity in resting-state.When the task was internet-related,internet addicts showed enhanced executive control function.However,when the task was not internet-related,they showed reduced executive control function.In the aspect of decision-making system,reduced cortical thickness in related brain areas was found when internet addicts are in resting-state,and they possess high impulsivity and high risk tendency when they are in induced state.These findings are consistent with the conclusions of substance addicts which are based on the research of brain imaging,therefore,we preliminary think the internet addiction is a new type of addictive mental disorder.

OBJECTIVE:To establish the HS-GC method for the content determination of menthol in Qiangli Pipa syrup,and the content of menthol in 56 batches of Qiangli Pipa syrup commercially available was determined. METHODS:HS-GC was per-formed on the column of Agilent HP-INNOWAX,column temperature was 130 ℃(maintaining 7 min),FID was used as detector, inlet temperature was 200 ℃,detector temperature was 250 ℃,carrier gas was high-purity nitrogen,flow rate was 3 ml/min,split ratio was 10∶1 and the injection volume was 1 000 μl. RESULTS:The linear range of menthol was 0.007 07-0.141 40 mg/ml(r=0.999 1);RSDs of precision,reproducibility and stability tests were no more than 3.37%;average recovery was 94.3%-99.6%(RSD=1.86%,n=6). There was significant difference in the contents of menthol in 56 batches Qiangli Pipa syrup. CONCLU-SIONS:The method is simple,sensitive,accurate and reliable,and can be used for content determination of menthol in Qiangli Pi-pa syrup. The sampling results show it is necessary to update the detecting items for the content of Qiangli pipa loquat and strength-en the quality control of it.