The artifacts in magnetic resonance imagines(MRI) seriously degrade the imagine quality and affect the exact diagnosis. The reasons that may cause artifacts in magnetic resonance imaging and the suppressing methods are presented in this paper. One of the intractability appeared in researches is how to restrain all kinds of artifacts quickly and efficiently. It is important to search for new methods to solve this problem. It may provide reliable basis for medical observation and clinical diagnosis.

Objective To explore the clinical significance of coagulation factor and fibrinolytic indexes in viral hepatitis and pregnant hepatitis. Methods 142 inpatients with viral hepatitis classified into five subgroups (acute hepatitis; mild chronic hepatitis; chronic moderate/severe hepatitis; cirrhosis and severe hepatitis),and 35 cases of pregnant hepatitis were measured eight indexes of FV:C、FVⅡ:C、FX:C、PL:A、t-PA:A、PAI:A、D-D和FDP respectively and the results were compared with that of 90 cases from normal control group and 32 cases of normal pregnant women. Results Compared with control, plasma FV: C increased evidently in acute hepatitis (P

Drug addiction is a chronic relapsing brain disease that is characterized by compulsive drug use and persistence of drug craving. Drug abuse can lead to changes in the neuron structure and function of plasticity,alterations in molecules and cells,and ultimately to individual abnormal behavior. Current studies have found that epigenetic changes leading to the sustainability of gene expression is an important mechanism of drug addiction. In this review,we will systematically summarize the latest advances in epigenetic mechanisms of drug addiction. This review is expected to provide robust evidence that repeated exposure to drugs of abuse induces changes within the brain′s reward regions in three major modes of epigenetic regulation-histone modifications such as acetylation and methylation , DNA methylation,and non-coding RNAs. It promises a new perspective from which to gain insights into the genetic and epigenetic mechanisms of drug addiction and a new area for epigenetic research on clinical drug addiction treatment.

Objective To study the antimicrobial resistance changes of common pathogenic bacterial isolates in Guangzhou. Methods Disc diffusion test was used to measure the antibiotic susceptibility of 5063 strains collected from 13 hospitals in Guangzhou from 1998 to 2000 (Fastidious bacteria were detected by E test). Results From 1998 to 2000, the percentage of methicillin resistant Staphylococcus aureus was 45.3%,53.0%, and 50.8%, respectively, and that of methicillin resistant coagulase negative Staphylococcus was 64.1%, 86.0%, and 79.0% accordingly. There was no resistance to vancomycin in the strains of Staphyloccocas and there were 40.7%, 31.8% and 36.4% in E.coli and 43.1%, 42.7%, and 31.5% in Klebsiella found to be extended spectrum lactamases producing in the 3 years. Resistant rates of Enterobacter spp against the third generation cephalosporins increased. Resistant rates of P.aeruginosa against cefoperazone/sulbactam, ceftazidime,amikacin were changed unmarkedly in recent years. Conclusions The antimicrobial resistance of common pathogenic bacteria is serious in Guangzhou area. The surveillance of antimicrobial susceptibility is of great significance.

Objective To explore the effect of the standardized swallowing assessment (SSA) on extubation time for patients with nasal feeding. Methods One hundred patients with nasal feeding in our department from January 2013 to December 2014 were divided into the observation group and control group randomly with 50 in each group. The control group was treated with education on aspiratioin prevention and the right time for extubation was decided following doctor′s order. SSA was used in the observation group with weekly SSA and swallowing function, then the patients took pertinent functional exercises till a right time for extubation was decided. The two groups were compared in terms of incidences of re-intubation and aspiration pneumonia. Result The observation group had significantly lower incidences of re-intubation and aspiration pneumonia than the control one (P<0.01). Conclusions SSA is used to assess the swallowing function as well as the aspiration risks , which helps patients to take functional exercise and helps nurses to decide the right time for extubation. It can effectively lower the incidences of re-intubation and aspiration pneumonia and improve patients′prognosis.

OBJECTIVE To analyze the sequence of IMP-4 metallo-?-lactamases(MBLs) encoding gene from clinical isolates of multiple-drug-resistant Klebsiella oxytoca strains and attempt to know the integrons composing the drug resistance gene box.METHODS The antibiotic sensitivity test of multi-resistant K.oxytoca strains was done according to Kirby-Bauer method of CLSI 2005,and the double disk synergy test and Etest were for detecting their MBLs.The Class 1 integrons were detected by PCR.The purified amplicons of Class l integrons were sequenced.The type and order of gene cassettes in integrons were analyzed by searching GenBank.RESULTS The K.oxytoca was resistant to carbapenems,the third-generation cephalosporins,cefoxitin,quinolones,cefoperazone/sulbactam,sulfamethoxazole/trimethoprim,amoxicillin/clavulanate,ticacillin/clavulanate,piperacillin,cefepime,rifampicin and piperacillin/tazobatam,only susceptible to amikacin and polymyxin B.The IMP-4 metallo-?-lactamases,aadA1,AmpC,CTX-M-14,qacE△1-sull and intI1 were positive.CONCLUSIONS Integrons are important molecular mechanism in the development of multidrug resistance.There are resistance gene boxes in them.

OBJECTIVE To investigate the genotypes of aminoglycoside-modifying enzymes(AMEs)genes of Acinetobacter baumannii.METHODS Clinical isolates of A.baumannii were collected from 2003 to 2006,and their resistance to gentamicin,amikacin and tobramycin were tested by K-B method.Twenty-three isolates were chosen because of their resistance to aminoglycoside antibiotics(at least resistant to one kind of the drugs).Nine types of the AMEs were detected by PCR.RESULTS Drug resistant rates of 23 isolates of A.baumannii to gentamicin,amikacin and tobramycin,were 86.96%,56.5% and 69.56%,respectively.The detection rates of the 9 AMEs,including ant(3')-Ⅰ,aac(3)-Ⅰ、aac(6')-Ⅰ,aph(3')-Ⅵ,aac(3)-Ⅱ,aac(6')-Ⅱ and ant(2″)-Ⅰ were 69.56%,60.87%,56.52%,47.82%,30.4%,26.09% and 21.73%,respectively.CONCLUSIONS The resistance to aminoglycoside antibiotics of A.baumannii is mainly caused by AMEs.

ObjectiveTo evaluate the discriminative stimulus effects of nicotine on the basis of a rat model of heroin discrimination.MethodsMale Sprague-Dawley rats were trained to discriminate 0.3 mg/kg heroin from saline under a fixed-ratio (FR10) schedule of food reinforcement.After training,different doses of heroin and nicotine were used to substitute for training dose of heroin,the dose-response curve for heroin and the discriminative stimulus effects of nicotine were identified in rats.ResultsAll rats reliably discriminated 0.3 mg/kg heroin from saline.Different doses of heroin ( 0.03,0.1,0.3,0.56 mg/kg ) produced ( 33.9 ± 15.0 ) ％,( 43.3 ± 13.3 ) ％,(98.7 ± 0.5 ) ％,(99.4 ± 0.2 ) ％ total responding on heroin associated lever,heroin at the doses of lower than 0.3 mg/kg produced the dose-dependent relationship in heroin-appropriate responding.In heroin-trained rats,nicotine at the dose of 0.03,0.1 mg/kg produced(1.9 ±1.1)％,(13.7 ±5.6)％ total responding on heroin associated lever,there were extremely significant differences with 0.3 mg/kg heroin control (P＜0.01).However,nicotine at the dose of 0.3,0.5 mg/kg produced ( 60.4 ± 16.1 ) ％,(65.9 ± 16.4) ％ total responding on heroin associated lever,there were no significant differences with 0.3 mg/kg heroin control (P＞ 0.05 ).ConclusionNicotine at the dose of 0.3,0.5 mg/kg can partially produce heroin-like discriminative stimulus effects.

Objective By making models of premature animal,explores the effects of dexamethasone on the brain development of premature rats and its mechanisms.Methods Eighteen SD rats were randomly divided into high-dexamethasone(H-Dex) group,low-dexamethasone (L-Dex) group and normal saline(NS) control group,with 6 rats in each group.The pregnant rats in L-Dex group were injected with dexamethasone [0.1 mg/(kg·d)] from 16 to 18 days of pregnancy,while the pregnant rats in H-Dex group were injected with dexamethasone [0.5 mg/(kg· d)] ; the pregnant rats in NS control group were injected with 0.9％ NaCl of the same volume.All of the fetal rats were received after administrating caesarean operation on the day 19 of pregnancy.Rats were sacrificed at the directed time and brain tissue was prepared.Histological feature and the water content of the brains were observed.Level of apoptosis was measured by flow cytometry.The expressions of myelin basic protein (MBP) and interleukin(IL)-1β in brain tissue homogenate were detected by ELISA.Results (1) The brain water contents of rats in H-Dex group,L-Dex group and NS control group were (85.94 ± 0.54) ％,(86.08 ± 1.01) ％,(86.94 ± 0.82) ％.Compared with NS control group,the water contents of Dex group were lower (P ＜ 0.05).(2) Glial cells of brain cortex in L-Dex group and H-Dex group were more mature than in NS control group,and the changes in H-Dex group was more significant.(3) The expressions of MBP in brain tissue of H-Dex group,L-Dex group and NS control group were (5.73 ± 1.06) μg/mg,(5.46 ±0.77) μg/mg and (2.42 ±0.52) μg/mg.Compared with NS control group,Dex group was higher(P ＜0.05).While the expressions of IL-1β in brain tissue of H-Dex group,L-Dex group and NS control group were (249.05 ± 11.29) pg/g,(257.47 ± 9.33) and (292.66 ± 21.51) pg/g.Compared with NS control group,Dex group was lower(P ＜ 0.05).There was no significant difference between H-Dex group and L-Dex group(P ＞ 0.05).(4) The level of apoptosis in H-Dex group,L-Dex group and NS control group were (18.07 ± 1.63) ％,(6.88 ± 0.47) ％ and (2.00 ± 0.32) ％.Compared with NS control group,the level of apoptosis in Dex group was higher(P ＜0.05),and H-Dex group was higher than that in L-Dex group.Conclusion (1) Using dexamethasone prophylactic could promote the development of glial cells,reduce the water content,increase the expressions of MBP,and decrease the expressions of IL-1β in brain tissues.It indicates that dexamethasone may play a major role in maturation of fetal brain.(2) Using dexamethasone prophylactic could increase the amounts of the apoptosis cells,and this effect is dose-dependent.It indicates that dexamethasone may have a negative effect on the fetal brain and suggestes that using dexamethasone in premature infant should be cautious,and if it has to,using a lower dose.