OBJECTIVE To investigate antibiotic resistance and distribution of meticillin-resistant Staphylococcus(MRS) and provide reference evidence in using antibiotics reasonably.METHODS Antibiotic susceptibility test was performed by K-B method and MRS were identified according to NCCLS(1999,2004).RESULTS Among 253 strains of Staphylococcus,meticillin-resistant S.aureus(MRSA) isolated ratio was 29.9% and meticillin-resistant coagulate-negative S.aureus(MRCNS)was 31.3%.The resistant ratio to clindamycin,erythromycin and ciprofloxacin in MRSA and MRCNS were higher than in meticillin-sensitive Staphylococcus(MSS) significantly.CONCLUSIONS The isolating ratio of MRSA and MRCNS is on rise.We should pay more attention to the identification and report of resistant strains and it is important to supervise nosocomial infection caused by Staphylococcus efficiently.

OBJECTIVE: To facilitate the implementation of Prescription Administrative Policy ( "Policy" for short), and provide basis for Medical Administrative Departments to perfect prescription management. METHODS: 218 questionnaires collected from medical staffs in 14 primary level hospitals were subjected to an aggregate analysis in respect of their cognition on the "Policy" , prescription standards and the enforcement condition of the "Policy" . RESULTS: Of the 218 medical staff, 36.7% had the knowledge on prescription standards in "Policy" , 35.78% had the knowledge of generic names of the prescribed medicines. Among the 14 primary level medical institutions, only 36.36% used the standard emergency prescriptions and paediatric prescriptions, and 47.76% kept samples of doctors' signatures. CONCLUSIONS: The "Policy" was poorly implemented in the primary level medical institution. Therefore, it is necessary to strengthen the education and training of the medical staff, meanwhile the Medical Administrative Departments should strengthen their administrative leadership and guidance, and put forward the relevant policy and bylaws aimed at the confusions existing with the medical institutes so as to facilitate a better implementation of the Policy.

Objective To observe some current dilemmas in the treatment of extremely preterm infants and to explore the method to solve the problems.Methods To analyze the problems with Bioethics.Results To advance some methods for solving the bioethical problems associated with medical staffs,parents,and the society.Conclusions Medical staffs should keep studying professional knowledge,understand the advances in the treatment of extremely preterm infants,improve the ability and skills to inform parents,diagnose and treat according to related guidelines,respect the rights and decision of the parents,and provide scientific guidance.The parents should be actively involved in medical activities and informed the rights,responsibilities in the treatment of their infants.Society should also take into consideration the interests of this special group in the field of insurance with the development of economy.

Objective To develop a new Multiplex Allele-Specific polymerase chain reaction(MAS-PCR) assay to detect the main point mutations in the katG and rpoB genes, which has been reported to account for the majority of clinical Mycobaterium tuberculosis resistant to isoniazid and rifampin. Methods Based on the sequences of katG and rpoB genes, specific primers were designed to carry out the MAS-PCR to detect the most common mutations in codon315 of katG and codons 531,526,516 of rpoB gene. Results The purified DNA preparation of 96 clinical Mycobacterium tuberculosis strains were used to optimize PCR. No mutation was detected in 19 isoniazid-sensitive strains. The 315Ser point mutation was detected in 79.2%(61/77)of isoniazid-resistant strains, the type of mutation includes the most common S315T and the less common S315N, which could’t be detected by PCR-RFLP(polymerase chain reaction-restriction fragment length polymorphism). However, S315G couldn’t be detected by MAS-PCR and that will make a false negative. The mutations in codons 531,526,516 were detected by the MAS-PCR. Compared with the results of direct sequencing of rpoB gene, no mutation was detected in sensitive strains. For rifampin-resistant strains, the total sensitivity was 81.5%(66/81). Conclusions MAS-PCR is a new molecular method with high sensitivity and specificity, which can be used to detect the point mutation in katG and rpoB gene rapidly and economically. It can be used in clinical laboratories to detect drug-resistant tuberculosis strains. Simultaneous detection for katG and rpoB gene mutations in one MAS-PCR system will help to improve the efficiency of this method.

Objective To investigate the variability of katG gene in Mycobacterium tuberculosis strains isolated in China,and screen the new isoniazid resistance related mutation sites meanwhile. Methods 429 clinical Mycobacterium tuberculosis isolates were included in our research.PCR-RFLP method was applied to screen for the S315T mutation firstly.Whole katG gene sequencing was done in those resistant strains without S315T mutation to explore the unknown mutated sites associated with isoniazid resistance.Results S315 mutation were found in 76.9% (166/216)resistant stains. Complete or part deletion of katG gene was detected in 2 highly-resistant isolates.Sequencing in 48 resistant strains showed that 315,463 and 234 sites were the most frequent mutation sites,other sites were also found but distributed dispersedly with low prevalence rate as less than 5%.Besides S315T, S315N were also common in China (8.7%).The most common variation is still site mutation.Con- clusions The results from the study of genotypes associated with most common clinical resistant phe notypes can be helpful to develop new methods to detect the resistant M.tuberculosis.

Objective To clone and express inhA gene from mycobacterium tuberculosis , and purify the inhA protein. Methods Recombinant plasmid pET 24b/inhA was constructed and transferred into Escherichia coli . After restriction enzyme analysis and sequencing, the host bacteria were induced by IPTG and the product was identified by SDS PAGE. Furthermore, the overexpressed inhA protein was purified by Nit NTA Superflow system. Results The inhA gene was overexpressed in E. coli, the production was corresponding to 30 percent of total cell protein. Using Nit NTA Superflow,we can get more than 99% purified protein. Conclusions The cloning, expression and purification of inhA gene are successful.

Objective To detect rpoB mutations in rifampin resistant mycobacterium tuberculosis strains isolated from Shanghai, and to evaluate the implication of applicating line probe assay (LiPA). Methods A fragment (213bp) of rpoB gene of 58 Mycobacterium tuberculosis isolates was amplified and sequenced, 18 rifampin resistant strains and 10 susceptible strains were selected to detect mutation by LiPA. Results Mutations of rpoB gene in 17 strains of the 18 rifampin resistant isolates were found by LiPA, and there were no mutations in any of the 10 susceptible strains. The sensitivity of LiPA was 94.4% and the concordance with drug susceptibility of Mycobacterium tuberculosis was 96.4%. Conclusions LiPA is a useful method for the rapid detection of mutations of rpoB gene in rifampin resistant Mycobacterium tuberculosis with high sensitivity.

Objective To investigate the signaling mechanisms underlying synergistic induction of MUC5AC mucin by nontypeable Haemophilus influenzae(NTHi)and epidermal growth factor (EGF).Methods The expression of MUC5AC was measured by real-time quantitative polymerase chain reaction(PCR)and Luciferase assay.Western blot was performed to examine the synergistic induction of phosphorylation of P38,extracellular signal-regulated kinase(ERK)and P21-activated kinase(PAK)4 or the effect of dominant negative mutant of PAK4 on the synerglstic induction of phosphorvlation of P38 mitogen-activated protein kinase(P38MAPK)and ERK in HM3 cells treated with NTHi and EGF.Luciferase asgay was also performed to examine the effect of P38,ERK inhibitors or dominant negative mutants of P38MAPK and ERK on synergistic enhancement of NTHi-induced MUC5AC up-regulation by EGF at transcriptional level.Real-time quantitative PCR was performed to examine the effect of PAK4 siRNA on synergistic induction of NTHi-induced MUC5AC up-regulation by EGF.ResuIts NTHi induced MUC5AC mucin expression at both mRNA and transcriptional levels.Synergistic induction of phosFIhorylation of P38MAPK,ERK and PAK4 were observed in HM3 cells treated with NTHi and EGF.Either SB203580,a specific inhibitor for P38MAPK or PD98059,a specific inhibitor for ERK inhibited synergistic induction of MUC5AC at transcription level.Furthmore, overexpressing dominant negative mutant of P38MAPK and ERK also inhibited synergistic induction of MUC5AC at transcription level. PAK4 siRNA inhibited the synergistic induction of MUC5AC by NTHi and EGF. Overexpressing dominant negative mutant of PAK4 also reduccd synergistic induction of phosphorylation of P38 and ERK. Conclusion Synergistic induction of MUC5AC mucin by NTHi is up-regulated by EGF via PAK4-dependent P38MAPK and ERK pathways.

OBJECTIVE To observe the effect of mannitol on oxidative stress of human kidney tubular epithelial cells(HK-2). METHODS MTT assay was applied to detect HK-2 cell viability after ex?posure to different concentrations(50,100,150,200,250,300,350 and 400 mmol · L-1)of mannitol for 4,10,24,48 and 72 h. DCFH-DA method was used to determine the level of reactive oxygen species (ROS)after HK-2 cells were exposed to mannitol 100 and 250 mmol · L-1 for 4 h. Furthermore,cell morphology and indexes of oxidative stress such as malondialdehyde(MDA) content,superoxide dismutase(SOD )activity and glutathione(GSH) content were observed at different time points. RESULTS HK-2 cell viability decreased by about 50%after being treated with mannitol 250 mmol · L-1 for 72 h (P<0.05). ROS production in mannitol 250 mmol · L-1 treated group (68.7 ± 3.6) was higher than in solvent control group(50.3 ± 4.6)(P<0.05). HK-2 cells exhibited morphological changes after treatment with mannitol 250 mmol · L-1 for 4-72 h,including cell swelling,vacuoles and fall off. After treatment with mannitol 250 mmol · L-1 for 4,10,24,48 ahd 72 h,the MDA content increased signifi?cantly(P<0.05),while the activity of SOD and the content of GSH decreased significantly compared with solvent control group(P<0.05). CONCLUSION Over-production of ROS in HK-2 cells induced by high concentration(250 mmol·L-1)of mannitol may cause lipid peroxidation and injure the ability of an?tioxidation,which may contribute to mannitol induced cytotoxicity.

Objective To compare image quality and radiation dose of the new imaging plate (IP) with the used IP on computed radiography (CR),and to investigate the using principle in the two kinds of IP. Methods The dark noise, uniformity and erasure thoroughness of the new and the used IP were measured respectively.Based on threshold contrast-detail detectability(TCCD) technique,the phantom T0.16 photography was done at 75 kV,and with the two kinds of IP respectively.Three observers scored each image sequence using double blind method,calculated the threshold detection index (HT).The volunteers were randomly divided into three groups:the knee joint group,the chest group and the lumbar group.Each group had 50 cases and checked with the same condition as the phantom.Three radiologists using double blind method evaluated the imaging quality of knee joint,chest and lumbar.Results The physical characteristic indexes of the new and the used IP were similar to each other.Under the same condition,the detection ability of the new IP was better than that of the used one.When the dose of exposure was raised about 20%,the detection ability of the used IP was close to that of the new one.Conclusions The dose of exposure can be raised to keep the same imaging quality with the increase times of IP used.The detection ability of IP can decrease with the same dose as before,and the image quality decreases too.