[To discuss the vancomycin-resistant staphylococcus aureus and vancomycin-resistant enterococcus from laboratory view].
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Clinical Laboratory Techniques↗
Biomedical subjects
Ying-chun Xu
Publications and source records attributed to Ying-chun Xu.
[Molecular mechanism of multiple-drug and pan-drug resistance among Acinetobacter species].
OBJECTIVE: To investigate the molecular mechanism of multiple-drug and pan-drug resistance among Acinetobacter species. METHODS: Non-repetitive 90 carbapenem-resistant strains of Acinetobacter species were collected in Beijing, Guangzhou, and Fuzhou 1999-2004. The homology of the isolates was determined by both pulsed field gel electrophoresis and randomly amplified polymorphic DNA typing. Seven representative clones were selected from the 90 strains of Acinetobacter isolated from different hospitals to be used for further study. Analytical isoelectric focusing was used to measure the isoelectric point of the beta-lactamase. Plasmid DNA was extracted and purified Genes of different beta-lactamase, including bla(TEM--), bla(SHV-), bla(PER-), blaI(MP-), bla(VIM-), and bla(OXA-) genes, in these clone strains were amplified and sequenced. PCR was used to analyze the integrons. RESULTS: The P clone strain isolated during an outbreak of pan-drug-resistant Acinetobacter species in Peking Union Medical College Hospital 2004 was not susceptible to most common antimicrobial agents tested. The 7 representative clones produced multiple beta-lactamases: TEM-1, high-level AmpC, SHV-type, OXA-23 carbapenemase and IMP-8 and metalloenzyme respectively. One clone produced PER-1 enzyme. These 7 clone strains were resistant to most beta-lactams (including carbapenems), erythromycin, chloramphenicol, and rifampin. Two clone strains were susceptible to cefoperazone/sulbactam and amikacin while 4 clone strains susceptible to levofloxacin. All of the 7 clones were susceptible to minocycline and colistin. Five different integrons were found, harboring the genes mediating the resistance to aminoglycosides, rifampin, chloramphenicol, and carbapenems (bla(IMP-8)). CONCLUSION: The molecular bases of multiple-drug or pan-drug resistance in Acinetobacter species include production of OXA-23 carbapenemase or IMP type metalloenzyme and integrons with different resistance gene cassettes. Pan-drug-resistant Acinetobacter species are susceptible to old antimicrobials agents, such as colistin and minocycline.
Acinetobacter↗
[Clinical study on drug-seperated moxibustion at Shenque (CV 8) for treatment of ulcerative colitis].
OBJECTIVE: To observe the therapeutic effect of drug-separated moxibustion at Shenque (CV 8) on ulcerative colitis (UC) and the influence on autoimmunity level, and study on the mechanism. METHODS: Sixty cases were randomly divided into a treatment group and a control group, 30 cases in each group. The treatment group were treated with drug-separated moxibustion at Shenque (CV 8) and the control group with oral administration of sulphasalazine and metronidazole tablets. The main symptoms, pathological changes of the intestinal mucosa and the total therapeutic effect in the two groups before and after treatment, and the changes of the content of blood serum immunoglobulin, peripheral blood T-cell subgroup and NK cell were observed. RESULTS: The markedly effective rate and the total effective rate in the treatment group were 60.0% and 86.7% respectively, much higher than the control group (P<0.05, P<0.01). IgG content in the treatment group after treatment significantly decreased with a significant difference as compared with the control group (P<0.05); there were no significant differences in IgA and IgM before and after the treatment (P>0.05). After treatment, peripheral blood T-cell subgroup and NK cell in the treatment group increased to a certain extent, which was correlated positively to the therapeutic effect. CONCLUSION: The drug-separated moxibustion at Shenque (CV 8) is a satisfactory method for treatment of ulcerative colitis, and it exerts therapeutic effect possibly through regulating immunological function of the organism.
Acupuncture Points↗
[Effects of irrigation volume on growth and quality of Lonicera japonica].
OBJECTIVE: To study the effects of irrigation volume on the growth and quality of Lonicera japonica. METHOD: Different volume of irrigation water was applied to the potted L. japonica before the first florescence of honeysuckle in order to keep the relative moisture content of the soil as 100%, 80%, 50%, 30%, and observe the growth and development of shoot and leaves, yield and quality of honeysuckle. RESULT: As the of irrigation volume was reduced, the internodal elongation of shoot and the increase of the knot were restrained, and the yield of honeysuckle dropped. But the content of chlorogen acid in the buds treated by 80% irrigation volume was not affected, while that of the other treatment all decreased. The moisture contents of the leaves treated by 30% irrigation volume was significantly lower than that of the CK, while the specific leaf weight (SLW) increased significantly comparing to the CK. The content of chlorophyl in the leaves of 50% and 30% increased, while the ratio of chlorophyl A and B fell significantly. The content of dissoluble suger in the leaves of 80% and 50% irrigation volume was much higher than that in the CK. The results also showed that, the content of dissoluble protein in the leaves of 30% irrigation volume increased comparing with that in 50%, and the content of proline in leaveas of 30% irrigation volume increased significantly. CONCLUSION: Using less irrigation volume (keeping 80% of relative moisture content of the soil) does not affect the quality of honeysuckle, but decreased dry weight of honeysuckle. It is necessary to take irrigation management during cultivation of honeysuckle.
Biomass↗
[Effects of water stress on the growth of Lonicera japonica and quality of honeysuckle].
OBJECTIVE: Effects of water stress on the growth of Lonicera japonica and quality of honeysuckle were studied. METHODS: Different extent water stress treatment imposed to potted plants before the first florescence of honeysuckle, and the growth and related physiological indexes of Lonicera japonica were determined. RESULTS: Shoot grow slowly as well as the increases of specific weight of leaf and the decrease of the yield of honeysuckle under water stress. The contents of chlorophyl in the leaves treated water stress all increased, and the content of soluble suger had a rising stream. The content of soluble protein in leaves of plant imposed by minor stress treatment was obviously higher than that of CK and severe stress treatment. As the stress was hard, the content of proline in leaves increased significantly. With water stress severing, the content of chlorogenic acid in the flower bud decreased very significantly than CK. CONCLUSION: Water condition was a important factor affected the growth and development of shoots, leaves and flower buds as well as the quality of honeysuckle. In the cultivation of Loniccra japonica, irrigation timing and certain irrigation condition was necessary.
Chlorogenic Acid↗
[The relationship between abnormal MDR gene expression and chemotherapy response in lymphoid malignancies].
OBJECTIVE: To investigate the expression of multidrug resistance-1 (MDR(1)), Topoisomerase II (Topo II), glucocorticoid receptor (GCR) and their correlation with relapse rate and chemotherapy response in lymphoid malignancies. METHODS: The expression of MDR(1), Topo II and GCR in 189 patients with lymphoid neoplasms was examined by RT-PCR, slot blot and ligand-labelled methods. RESULTS: (1) The expressions of MDR(1), Topo II, GCR in untreated and relapsed/refractory patients with ALL, NHL, NHL-L, MM were significantly abnormal at varying levels, especially in the relapsed/refractory group. (2) The complete remission (CR) rate of MDR(1) high expression group (MDR(1)(+)) was significantly lower than that of MDR(1) negative expression (MDR(1)(-)) group (P < 0.05), and the relapse rate of MDR(1)(+) group was significantly higher than that of MDR(1)(-) group (P < 0.05). In untreated patients, the relapse rate in the Topo II low expression (Topo II(-)) group was positively higher than Topo II high expression (Topo II(+)) group (P < 0.05), whereas in the relapsed/refractory patients, the CR rate of Topo II(-) group was significantly lower than that of Topo II(+) group (P < 0.05). In the untreated and relapsed/refractory patients, the CR rates of low GCR expression (GCR(-)) group was obviously lower than that in the normal GCR expression group (P < 0.05). (3) Considering mono-drug resistance mechanism, CR rate of MDR(1)(+) group was the lowest, Topo II(-) group took the second place and GCR(-) group was the highest. As multiple drug resistance mechanisms coexisted, the CR rate of MDR(1)(+) + Topo II(-) + GCR(-) group and MDR(1)(+) + Topo II(-) group (11.1% and 15.4%, respectively) were significantly lower than that of MDR(1)(+), Topo II(-) and GCR(-) group (36.7%, 48.0% and 53.8%, respectively; P < 0.05 - P < 0.001). CONCLUSION: There are primary and acquired drug resistance in lymphoid neoplasms. The high expression of MDR(1), low expression of Topo II and GCR are positively related to low chemotherapy response rate and high 2-year relapse rate. Co-analysis of MDR(1), Topo II and GCR may play an important role on chemotherapy response and prognostic judgment in lymphoid neoplasms.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
[Mechanism of carbapenems resistance in Acinetobacter baumannii].
OBJECTIVE: To investigate the mechanism of carbapenems resistance in Acinetobacter baumannii. METHODS: WHONET-5 software was used to analyze the trend of carbapenem resistance in Acinetobacter baumannii collected from 1999 to 2001 at Peking Union Medical College Hospital. Analytical isoelectric focusing was used to measure the pI of the beta-lactamase. Conjugation experiment was used to study the transfer of carbapenem resistance and plasmid DNA was extracted and purified with Qiagen Plasmid Mini Kit. The homology of the isolates was determined by pulsed field gel electrophoresis (PFGE). Integrase genes and blaIMP-, blaVIM-, blaOXA- genes for resistant isolates were amplified and sequenced. RESULTS: Imipenem resistance in A. baumannii was ranged from 1.8%-8.5%, but only 9 resistant isolates were viable. They were co-resistant to other carbapenems, ceftazidime, aztreonam, and gentamicin, and four isolates were resistant to ciprofloxacin. Impipenem resistance could not be transferred to susceptible strains. No plasmid was extracted. Each isolate produced TEM-1, AmpC, and two enzymes (pI 6.7, 6.0), which can not be inhibited by cloxacillin and clavulanic acid. Each isolate had class I intergase gene. Nine isolates were all negative for PCR of blaIMP- and blaVIM- genes, but positive for blaOXA-23 specific PCR. Sequencing found 100% homology with blaOXA-23. PFGE found 3 clones (A type: 5 isolates; B type: 3 isolates; C type: 1 isolate). Control isolates (imipenem-susceptible, but ceftazidime, ciprofloxacin, and gentamicin resistant) were also A clone. CONCLUSIONS: Production of OXA-23 carbapenemase in A. baumannii was one of the main mechanisms of carbapenems resistance at our hospital. It brings concern that imipenem-resistant clone has evoluted from nosocomial multiple-resistant strains.
Acinetobacter baumannii↗