1.Bactericidal effect of a novel peptide on oral microorganisms
Xiu YING ; Yingming SUN ; Rui TAO ; Mengjie ZHANG ; Xiu JIANG
Journal of Medical Postgraduates 2016;29(4):359-363
Objective Antimicrobial peptides are the focus of recent research in oral microbiology .This study aimed to eval-uate the activity of a novel antimicrobial peptide pm 11 against oral microorganisms and its action mechanisms . Methods We ana-lyzed the effect of pm11 on oral microorganisms and determined its antimicrobial activity in the saliva environment by measuring its min -imal inhibitory concentration (MIC), minimal bactericide concentration (MBC), and bactericidal kinetics.We observed its bacteri-cidal activity on the biofilms of streptococcus mutans by confocal laser scanning microscopy (CLSM) and the structural changes in the bacterial membrane by scanning electron microscopy (SEM). Results The antimicrobial activity of pm11 varied greatly against dif-ferent oral microorganisms , with its MIC values ranging from 2 μg/mL to 256 μg/mL and its MBC values from 2 μg/mL to >256μg/mL.The bactericidal kinetics showed a decreasing survival rate of bacteria with the lengthening of the intervention time .The inhib-itory-zone diameters exhibited no significant indifference between the water solution and the sterile saliva solution .CLSM revealed an increased number of dead bacteria in the pm 11-treated biofilms , while SEM manifested obvious changes in the shape of the bacteria membrane treated with pm11. Conclusion Our findings suggest that pm11 has a broad spectrum of antimicrobial activities on oral mi-croorganisms and a potential value of clinical application .
3.Action mechanisms of acid-resistant Streptococcus sanguis against Streptococcus mutans
Xiu JIANG ; Yingming SUN ; Rui TAO ; Mengjie ZHANG ; Mengyao HOU
Journal of Medical Postgraduates 2017;30(4):371-375
Objective Streptococcus sanguis is a possible candidate bacterium for the caries replacement therapy, which has no advantages in the acidic environment.The aim of the study was to construct acid-resistant strains of Streptococcus sanguis, determine its acid tolerance, and explore the mechanism of its antagonism against Sterptococcus mutans.Methods By gradually reducing the pH value of the medium, we constructed acid-resistant strains of Streptococcus sanguis, observed their growth and measured their acid tolerance according to their survival rate against lethal pH.We evaluated the competitive relationship between Streptococcus sanguis and Streptococcus mutans by plate experiment and detected the changes of related acid resistance genes by real-time quantitative PCR.Results The growth of Streptococcus sanguis and its acid-resistant strains were limited by the pH value, and that of Streptococcus sanguis was better in either acidic or normal environment.The lethal pH value of Streptococcus sanguis was 3.6, that of its acid-resistant strains was 2.3, and the survival rate of the acid-resistant strains was 66.59% in the pH 3.6 environment.In comparison, the lethal pH value of Streptococcus mutans was 2.5, that of its acid-resistant strains was 2.1, and the survival rate of the acid-resistant strains was 2.55% in the pH 2.5 environment.In the presence of chloramphenicol, the acid-resistant strains could not survive in the original lethal pH.In the sub-lethal pH environment, the expressions of the acid resistance-related genes Groel and Dnak in the acid-resistant strains were significantly up-regulated as compared with those in the original Streptococcus sanguis (P<0.05).Conclusion Streptococcus sanguis has an acid adaptability and can enhance acid resistance in the sub-lethal pH environment.Acid-resistant Streptococcus sanguis in the replacement therapy may provide some new ideas for the treatment of dental caries.
4.Nursing intervention on the pregnant women with syphilis during pregnancy
Qi-Yan CHEN ; Rong-Lian ZHANG ; Ning HUANG ; Xiu-Min JIANG ; Xiao-Yan XIU
Chinese Journal of Modern Nursing 2012;18(9):1012-1015
Objective To explore the nursing intervention on the pregnant women with syphilis during pregnancy so as to reduce the harm to maternal and baby.Methods Many information such as age,occupation,dwelling environment,marriage and sexual life,curing during pregnancy,pregnant and perinatal infant outcome from medical records were reviewed. Gestational syphilis women of 847 cases were randomly divided into nursing intervention group with 427 cases and control group with 420 cases.Nursing intervention group received one-by-one psychological care and health education,got cooperation from families,and received routine blood test and cure cooperation,while control group only received routine blood test and curing cooperation.Patients were followed up for seven days.Results The rate of adherence to treatment in nursing intervention group was 98.1% which was significantly higher than 61.7% in control group ( x2 =176.2,P < 0.01 ),and the rate of accepting standard treatment between early and late pregnancy,middle and late pregnancy were significantly higher than that in control group ( x2 =17.8,P < 0.01 ).The week was shorter for receiving nursing intervention and the patients' compliance was better ( P < 0.01 ). Only 23 syphilis infection babies in the nursing intervention group were born,but 149 babies in control group were infected by syphilis,and the difference was significantly different( x2 =123.2,P < 0.01 ).Conclusions Nursing intervention can effectively increase the compliance of pregnant women with syphilis and improve the outcome of pregnancy and perinatal infant.
5.Significance of visual electrophysiological techniques in the early diagnosis of glaucoma
Xiao-Pei, ZHANG ; Xiu-Ming, SU ; Mu-Di, YAO ; Qin, JIANG ; Guo-Fan, CAO
International Eye Science 2016;16(11):2044-2047
Glaucoma is a group of diseases which can threaten and damage the optic nerve and its visual pathway, leading to visual impairment as a result. Glaucomatous optic neuropathy is a chronic disease accompanied by apoptosis of retinal ganglion cells ( RGCs ) , visual field defect and cupping of optic nerve head. The gold standard in functional glaucoma evaluation is standard automated perimetry ( SAP) , but it is often limited to the subjective feelings of the patients. Still, visual electrophysiological techniques cannot replace the conventional inspection, but with its rapid development, it has provided a new strategy for the early diagnosis of glaucoma as a supplement because it can show changes in amplitude and latency before visual field defect. Here we review three special electroretinograms and multifocal focal visually evoked potentials in the early diagnosis of glaucoma.
6.Comparative cardiotoxicity of propofol and thiopental in neonatal primary myocardial cell cultures
Tie-Zheng ZHANG ; Feng-Xue WANG ; Xiao-Jiang XIU ; Chao-Ren WANG ;
Chinese Journal of Clinical Pharmacology and Therapeutics 1999;0(04):-
Aim To investigate the cardiotoxicity of propofol and thiopental. Methods 4day-old contracting neonatal primary myocardial cells obtained from 2-to 3-day-oldWistar rats were divided into 5 groups, with normal contrast group, and the cellcultures in groups PL, PH, TL and TH, were treated with propofol(3 ? 10-5 and3 ? 10-4 mol? L) and thiopental (1 ? 10-5 and 1 ? 10-4 mol?L) for 8 h.The con-tractility and morphology of the cells were observed and the cytoplasmic enzyme(LDH, AST, CK and ALP) release content of myocardial cell and the concentrationof electrolytes (K +, Na +, Cl - and Ca2+ ) in the medium were measured 8 h afterintravenous anesthetics administration. Results In groupPH and TL decreasedsignificantly (P
7.Evaluation of Vitek 2 Compact for identification of clinically relevant bacteria and yeasts
Yao WANG ; Ying-Chun XU ; Xiu-Li XIE ; Xiao-Jiang ZHANG ; Min-Jun CHEN ;
Chinese Journal of Laboratory Medicine 2001;0(01):-
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.
8.Evaluation of Vitek 2 Compact for antimicrobial susceptibility testing of clinically relevant bacteria
Yao WANG ; Ying-Chun XU ; Xiu-Li XIE ; Xiao-Jiang ZHANG ; Min-Jun CHEN ;
Chinese Journal of Laboratory Medicine 2003;0(09):-
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.
9.Study on the Separation and Purification Technology of Catalpol from Rehmannia by Macroporous Adsorption Resins
Xiu-Li ZHANG ; Jing-Yun WANG ; Bo JIANG ; Yan CHANG ; Li-Jia AN ;
China Biotechnology 2006;0(01):-
A separation technology of catalpol from Rehmannia with macroporpus adsorbent resins was investigated. The content of catalpol in the extract was determined by high performance liquid chromatography (HPLC). Nine different kinds of macroporous adsorbent resins were studied on the static capacity of adsorption and desorption, and D101 resin was best for the separation of the extraction solution of Rehmannia. The results showed that D101 resin had the highest static adsorption capacity of 69.2mg/g dry resin and its isotherm curve can be well described by Langmuir and Freudlich equation. The 5% ethanol elution on removal of the solvent under reduced pressure provided a brown powder, which was subjected to an open column chromatography on silica gel eluted with a CHCl3–MeOH gradient. The fraction eluted with CHCl3-MeOH (8∶2) was identified as catalpol and the purity of the compound was more than 90% purity by HPLC analysis. The yield of this separation technology was 6%.
10.Mesohepatectomy for treatment of central liver tumors
Changming WANG ; Shibing SONG ; Bin JIANG ; Yimu JIA ; Dianrong XIU ; Tonglin ZHANG
Chinese Journal of Hepatobiliary Surgery 2010;16(8):563-566
Objective To summarize the initial experience in application of mesohepatectomy for the treatment of central liver tumors while focusing on its indication, short-term and long-term prognosis and especially outlining its technical details. Methods The clinical data of 3 patients receiving mesohepatectomy from December 2007 to March 2009 in our hospital were retrospectively analyzed.The imaging characteristics were summarized to convey the indication details. The technique details of the operation were outlined so as to reduce blood loss or other complications during and after the operation. The post-operative course and follow-up data were also collected and analyzed. Results Two patients suffered from primary hepatocellular carcinoma with liver cirrhosis and the other from giant hemangioma. The tumors were located in Couinaud yegment Ⅳ and/or Ⅷ. The average blood loss and operative duration were 800 ml and 7 h, respectively. Blood liver function tests returned to normal within 7 days postoperatively and the patients were discharged after that. No complications occurred. The follow-up for 7-15 months showed that there was no recurrence. Conclusion Mesohepatectomy is the principal choice of treatment for centrally located liver tumors. For the safety and avoidance of complications, the doctor should abide by the concept of segment-oriented hepatectomy and apply the updated techniques such as CUSA (Cavitron ultrasonic surgical aspirator). For patients with compromised liver function, mesohepatectomy might be superior to extended bepatectomy. Thus, the application of mesohepatectomy should be expanded. Meanwhile, further investigation is needed for its full evaluation.