Objective To evaluate the influence of different field-strength magnets(1.5 T and 3.0 T)on MRI artifacts caused by Ni-Cr alloy fixed prostheses.Methods The crown,bridge and upper denture fixed prostheses with different thickness were produced by Ni-Cr alloy as test samples,and were one by one put on the centre of water phantom for MR scanning with different field-strength magnets(1.5 T and 3.0 T).The artifact areas on these two field-strength magnets were measured and statistically compared.The plastic prostheses with the same shape and thickness as the test samples were served as controls.Results Ni-Cr alloy fixed prostheses could cause MRI artifacts,and the artifact areas increased with the mass of prostheses.However,no artifact area was found in controls.Compared with those on 1.5 T magnet,the MRI artifact areas significantly increased on 3.0 T magnet(P

Methods of ELISA, nonradioactive molecular hybridiz ation and RT-PCR were applied in the detection of rice grassy stunt virus (RGSV ). The detection sensitivity of indirect ELISA using antiserum against fusion p rotein GST-NC was 1 mg of infected leaves or 84 ng of purified virus. The metho d of dot hybridization using NC, a DIG-labelled DNA probe was 50 μg diseased l e aves, or 6 ng purified preparations. The detection endpoint of RT-PCR was 10 μg diseased leaves, or 2 ng purified virus preparation. Comparisons of sensitivit y and maneuverability were made among these methods.

AIM: To explore the relationship between the expression of caspase-2 and caspase-3 and the apoptosis in retinal ischemia/reperfusion (I/R) injury of rats, as well as the therapeutic effects of brain derived neurotrophic factor (BDNF)on the ischemic and reperfused retina.METHODS: This experiment was conducted at the laboratory of Affiliated Hospital of Qingdao University Medical College from February 2007 to July 2007. The models of retinal ischemia/reperfusion injury were made by transiently elevating intraocular pressure. A total of 28 rats were divided into Normal and Operative Groups. Operative group was divided into six subgroups. In each subgroup there were four rats. The left eyes of rats were used for I/R and the right eyes were used for intravitreal injection of brain-derived neurotrophic factor (BDNF) as treatment group. After reperfusion we divided our subgroups according to the reperfusion time as 1, 6, 12, 24, 48, 72 hours. The retinal ganglion cell number was counted by using optic microscope(BX-51,Olympus). Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) method, and the expression of caspase-2,caspase-3 was studied by enzyme linked immunosorbent assay (ELISA) and strept avidin-biotin complex (SABC)immunohistochemistry.RESULTS: No positive apoptotic cells were observed in the normal rats' retinae, but there were a significant number of positive apoptosis cells in 6-24 hours after transient ischemia followed by a decrease at 48 hours. The number of apoptotic cells reached a maximum at 24 hours after ischemia .The expression of caspase-2 gradually increased as early as at 6 hours, reached a peak at 24 hours, then decreased between 48 and 72 hours. Similarly, caspase-3 has the same rule with caspsae-2 in the time courses of expression in retinal tissues.BDNF administered before reperfusion inhibited the expression of apoptosis and ameliorated the retinal tissue damage. It also decreased caspase-2 and caspase-3 expression in ischemic/reperfused retina.CONCLUSION: Retinal ischemia-reperfusion can induce apoptosis of cells in the retina. BDNF rescues retinal ganglion cells (RGCs) from retinal ischemia/reperfusion injury through down-regulation of cell apoptosis and caspase-2 and caspase-3 expression. BDNF have a neuroprotective effect on retina.

Cell Transformation, Neoplastic ; drug effects ; genetics ; Dimethyl Sulfoxide ; pharmacology ; Electroporation ; methods ; HL-60 Cells ; Humans ; Membrane Proteins ; genetics ; Neoplasm Proteins ; genetics ; RNA Interference ; RNA, Small Interfering ; genetics ; Stromal Interaction Molecule 1 ; Transfection

Objective To explore the characteristics viral pathogens in hospitalized children with lower respiratory infection,and to provide reference data for diagnosis and treatment.Methods Nasopharyngeal secretion(NPS) samples were collected from hospitalized patients with lower respiratory infection(LRI) from Dec.2005 to Apr.2006.The NPS samples were detected for 7 respiratory virus antigens including respiratory syncytial virus(RSV),influenza virus A and B(IVA and IVB),parainfluenza virus 1,2,3(PIV 1,2,3) and adenovirus(ADV) by indirect immunofluorescent assay.Results Nine hundred and thirty-five NPS samples were collected from children(597 boys,338 girls) with LRI.The mean age was 7.5 months(range from 1 day to 6 years).Viral pathogens were identified in 516(55.2%) samples.The positive rate of RSV decreased with increasing of age,whereas the positive rate of IV and PIV increased.ADV was only detected in children less than 3 years of age,accounting for 0.6%-6.2%.Conclusions Viral pathogens are the main etiology of LRI in young children in Beijing area from Dec.2005 to Apr.2006.RSV is the most frequent viral pathogens,followed by IV and PIV.

To control the quality of Humulus scandens, the quality standard was established in this study. According to the method recorded in the Appendix of Chinese Pharmacopoeia (2010 Edition) , the water and ash inspections were carried out. The component luteoloside and cosmosiin in Humulus scandens were identified and assayed by TLC and HPLC. The results showed a strong characteristics microscopic of Humulus scandens, and trichoromethane-methanol-formic acid (10: 3: 0. 3) as the mobile phase of TLC, the spots at 365 nm with a UV lamp was clear. The 16 batches of samples were analyzed by HPLC with a gradient elution of acetonitrile and phosphate solution (0.2%) at a flow rate of 1.0 mL · min(-1) and detected at 350 nm. The content of luteoloside was 0.015%- 0.651% (average 0.148%); the content of cosmosiin was 0.003%-0.118% (average 0.036%). The linear calibration curve of luteoloside and cosmosiin was acquired in the ranges of 0.011-0.364 g · L(-1) (r = 1.000 0) and 0.003-0.096 g · L(-1) (r = 1.000 0), respectively. The average recovery was 100.5% and 98.5%, respectively. The methods are convenient and reliable, which can be ap- plied for quality assessment of Humulus scandens.
China ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; analysis ; standards ; Humulus ; anatomy & histology ; chemistry ; Quality Control

Objective To evaluate a new system,Vitek 2 Compact,for antimicrobial susceptibility testing(AST)of gram-negative and gram-positive bacteria.Methods Eighty-nine clinical isolates of Peking Union Medical College Hospital,including 48 gram-negative strains and 41 gram-positive strains,and 66 reference strains kept in our laboratory,including 41 gram-negative strains and 25 gram-positive strains, were studied.The antimicrobial susceptibility of these strains were tested by Vitek 2 Compact with AST- GN09(for gram-negative bacteria),AST-P536(for Staphylococci),AST-P534(for Enterococci and S.agalactiae),and AST-P533(for S.pneumoniae)susceptibility cards.The Etest was used as the reference method for comparision.Thirty-two ESBL-producing strains assessed with the confirmatory tests for ESBLs of CLSI(16 strains of them had been confirmed by PCR amplified and sequencing)were detected for ESBLs by Vitek 2 Compact.Results According to the breakpoints of Clinical and Laboratory Standards Institute (CLSI),for the 1 626 microorganism-antibiotic combinations,Vitek 2 Compact gave 90.83% strains with category agreement(CA),4.91% strains with very major errors(VME),2.09% strains with major errors (ME),6.40% minor errors(MIE).The AST for more than 90% of Enterobacteriaceae,nonfermenting bacteria,micrococci and streptococci were completed within 11h,13h,11h and 12h,respectively.The ESBLs tests for thirty-two strains by V-itek 2 Compact are all positive.Conclusions Vitek 2 Compact system can give rapid,reliable and reproducible result with high sensitivity and specificity in assessment of antimicrobial susceptibility testing for clinically relevant gram-negative and gram-positive bacteria,and would become a powerful tool in clinical microbiology laboratory.

Objective To evaluate a new system,Vitek 2 Compact,for identification of bacteria and yeasts.Methods 185 clinical isolates of Peking Union Medical College Hospital,including 69 gram- positive strains,66 gram-negative strains and 50 yeasts,and 50 reference strains in our laboratory,including 25 gram-positive and gram-negative strains respectively,were studied.All the strains were identified by Vitek 2 Compact with GP,GN or YST identification cards.The API method was used as the reference method.Results Among the 93 gram-positive strains,85 strains(91.40%)were correctly identified, including 5 low discrimination identified strains,and 8 strains(8.60%)were correctly identified to the genus level,but misidentified to the species level.About 90% of gram-positive strains were identified within 7 h.Out of 91 gram-negative strains,90 strains(98.90%)were correctly identified,with 5 low discrimination identified strains,only 1 strain(1.1%)was correctly identified to the genus level,but misidentified to the species level.Above 90% of Enterobacteriaceae were identified within 5 h,and over 90% of nonfermenting bacteria were identified within 10 h.In the 50 strains of yeasts,46 strains(92%) were correctly identified,including 8 low discrimination identified strains,and 4 strains(8%)were correctly identified to the genus level,but misidentified to the species level.In all the yeasts,45 strains (90%)were identified in 18.25 h,and another 5 strains(10%)were identified in 18.50 h.Conclusions As Vitek 2 Compact system can give us reliable identification results of clinically relevant bacteria and yeasts,together with its significant reduction of handling time,it will definitely become a powerful tool in clinical microbiology laboratory.

Objective To compare BACTEC Plus aerobic and anaerobic bottles with BacT/ALERT FA aerobic bottles and FN anaerobic bottles in the ability of detecting simulated bacteremia specimens.Methods The 202 pairs of specimens were composed of 5ml sterile blood and defined loads of microorganisms.112 pairs of specimens in them also contained defined doses of antibiotics to simulate the patients undertaking antibiotic therapy.Time-to-detect(TTD)and positive percentages were evaluated in four groups,including aerobic bottles detecting aerobic bacteria,anaerobic bottles detecting anaerobic bacteria and facultative anaerobic bacteria,and aerobic bottles contained antibiotics detecting aerobic bacteria.Results The positive percentages of two kinds of aerobic bottles were both 100%.For the specimens with bacterial concentration of 10~2 and 10~3 CFU/ml,average TTDs of BACTEC Plus aerobic bottles[(13.69?3.74)h,(11.54?2.87)h]were faster than those of BacT/ALERT FA bottles [(16.76?5.62)h,(14.47?4.30)h;t=-5.674,-7.294,P

It is an important task to lab of clinical microbiology to surveille multi-drag or pan-drug resistant strains,such as penicillin-or macrolide-resistant Streptococcus pneumoniae,methicillin-resistant Staphylococcus aureus(MRSA),3rd generation cephalosporin-or quinolone-resistant Enterobacteriaceae, carbapenem-resistant Pseudomonas aeruginosa or Acinetobacter baumannii,and so on.We must understand characteristics of these resistant strains to guide doctors' empirical therapy of infective diseases.