Objective To investigate the species and drug resistance of pathogens causing bloodstream infections in hospitalized patients,and provide scientific evidence for antimicrobial use and control of healthcare-associated blood-stream infection.Methods From January 1 to December 31,2012,16 428 blood specimens were performed blood culture,pathogens were isolated and performed antimicrobial susceptibility testing.Results Of 16 428 blood speci-mens from 5 546 patients,384 (6.92%)were positive for blood culture,398 pathogenic isolates were detected,of which gram-positive bacteria,gram-negative bacteria,and fungi accounted for 23.62% (n=94),68.34% (n=272),and 8.04% (n=32)respectively,positive rate of blood culture were highest in 61-80 age group(8.26%), the top five departments of positive rate of blood culture were departments of burn,traditional Chinese medicine, cardiac intensive care unit,transplantation and traumatology;gram-positive cocci were highly susceptible to vanco-mycin,teicoplanin and linezolid,one Enterococcus faecium strain was found to be resistant to vancomycin;Among gram-negative bacilli,Enterobacteriaceae were highly susceptible to amikacin and carbapenems;drug resistance rates of Acinetobacterbaumannii and Pseudomonasaeruginosa to carbapenems was 70.97% and 35.90% respective-ly.Conclusion Gram-negative bacteria are the major pathogens causing bloodstream infection,positive rate of blood culture of elderly people is high.It is necessary to conduct regular surveillance on distribution and drug resistance of pathogens.

We analyzed the minus of present medical education,basing on questionnaires of 1773 medical students,including the students' participation rates in lectures of multiple fields and their demands on future lectures.We gave some pieces of advice to solve the problems as well as some references to boost our lectures.

ObjectiveTo determine the cerebral protection effect and mechanism of propofol on global cerebral ischemia and reperfusion damage in rats.Methods19 adult male Wistar rats were randomly divided into 3 groups, ischemia group (n=7), propofol group (n=7), and sham injury group (n=5). Global cerebral ischemia and reperfusion model were made by means of Pulsinelli's method. Rats in propofol group were anesthesia with propofol at the dosage of 1.5 ml/h for 30 min at the beginning of reperfusion. Apoptosis and necrosis rate were detected by cytometry. In the same time, bcl-2, Bax and p53 protein expression in hippocampus neurons were detected. ResultsThe apoptosis and necrosis rate in propofol group were significantly decreased as compared with ischemia group ( P<0.05). Bax and p53 protein expression in hippocampus neurons were also significantly decreased as compared with ischemia group (P<0.05), however, no significant findings in bcl-2 protein expression (P>0.05).ConclusionPropofol can decrease apoptosis and necrosis rate in cerebral ischemia reperfusion injured neuron, and the mechanism maybe related to decreasing the expression of Bax, p53 protein.

Objective To investigate the relationship between antibiotic use and antimicrobial resistance in Acinetobacter bau-mannii for rational use of antibiotics.Methods Antibiotic use density (AUD)of common antibiotics in hospitalized patients were collected in a tertiary hospital between 2006 and 2010.Clinical isolates of A.baumannii from those patients were collect-ed.The resistance to common antimicrobial agents were tested by disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI,2012)guidelines.Relationship between antibiotic use and antimicrobial resistance in A.baumannii was analysed by SPSS 16.0.Results The resistant rates of A.baumannii isolated from inpatients were high.Consumption of cephalosporins and quinolones were large.There was a positive correlation between the resistant rate of A.baumannii to imi-penem and AUD of carbapenems (r=0.975,P <0.05).The resistant rate of A.baumannii to meropenem showed significantly positive relation to AUD of carbapenems (r= 0.975,P <0.05).Resistant rates of aminoglycosides,quinolones,cephalospo-rins and beta-lactamase inhibitors was not correlated to AUD of those antibiotics.Conclusions We should pay more attention to the high prevalence of resistant A.baumannnii strains.Application of imipenem and meropenem should be strictly controlled.Amikacin and beta-lactamase inhibitors are better choice for empirical antibiotic therapy in the treatment of infections caused by A. baumannii.

This paper elaborates on the importance and necessity of implementing information technology in medical education,the application of information technology in the whole process of medical education,the conceptual construction of medical students' life-long education,the construction of practical teaching resources and the cultivation of information capacity both in teachers and students,etc.In the meantime,this paper introduces the basic framework of medical network and remote education center of Sun Yat-sen University under construction.

OBJECTIVETo identify the human hematopoietic stem cells from the human/goat xenogeneic model with molecular techniques.

METHODSDNA and total RNA were extracted from 11 transplanted goat peripheral blood cells. Human CD(34), GPA and SRY genes were amplified with PCR in these samples, and CD(34), GPA mRNA transcripts were detected using RT-PCR in 5 and 6 goat peripheral blood cells, respectively. Southern blot analysis was performed in 8 goat DNAs to detect the human specific alpha-satellite sequence. Meanwhile FISH was also performed to detect the human cells in goat blood with a probe of human Y chromosome.

RESULTSHuman CD(34) and GPA genes could be detected with PCR in all the 11 goats, and SRY gene did in 5 goats transplanted with hematopoietic stem cells derived from male human babies. Southern blot showed that human specific alpha-satellite sequence was present in 8 goats. By RT-PCR, human CD(34) mRNA was detected in 5 experimental goats, GPA mRNA was found in the other 6 experimental goats and FISH assay showed that some peripheral blood cells of the human/goat xenogeneic model were positive.

CONCLUSIONExistence of human cells in the recipient goats was identified by molecular detection, which was feasible for the examination of human/goat xenogeneic models.

Animals ; Antigens, CD34 ; genetics ; Blotting, Southern ; Female ; Genes, sry ; genetics ; Glycophorin ; genetics ; Goats ; Hematopoietic Stem Cell Transplantation ; methods ; Hematopoietic Stem Cells ; cytology ; metabolism ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Polymerase Chain Reaction ; Transplantation Chimera ; genetics ; Transplantation, Heterologous

OBJECTIVETo establish a high sensitive and specific method of interphase fluorescence in situ hybridization (IFISH) to detect the low-frequency human cells in human/goat xenogeneic models.

METHODSHuman-specific Y-chromosome satellite DNA CEPY and 17-chromosome satellite DNA p17H8 were used as probes for IFISH. The peripheral blood samples from 2 goats transplanted with human male hematopoietic stem cells (HSC), 1 normal negative goat and 1 normal man were analyzed. The actual FISH efficiency was confirmed by serial dilutions (1/100, 1/500 and 1/1000) of the cell mixture of normal man and normal negative goat. A set of signal scoring criteria was determined to guarantee the stability and reliability of the method.

RESULTSPositive cell (human cell) frequencies were consistent with the established frequencies for the human/goat cell mixture. The average frequencies of positive cells were 98.60% (CEPY) and 100% (p17H8) for normal man, 0 for normal negative goat, 0.23% (CEPY) and 0.11% (p17H8) for human/goat xenogeneic models. The results demonstrated that low-frequency human cells (male cells confirmed by Y-chromosome probe) existed in human/goat xenogeneic models.

CONCLUSIONThe IFISH developed in this study is of high sensitivity and specificity and can identify the actual frequency of human cells, which offers a direct, sensitive and specific approach to the detection of low-frequency human cells in human/goat xenogeneic models.

Animals ; Chromosomes, Human, Pair 17 ; genetics ; Chromosomes, Human, Y ; genetics ; DNA Probes ; Goats ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; cytology ; metabolism ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Interphase ; genetics ; Microsatellite Repeats ; genetics ; Transplantation Chimera ; blood ; genetics ; Transplantation, Heterologous

Objective To study the relationship between aquaporin 9 (AQP 9) gene and brain edema in neonatal rats of hypoxic-ischemic brain damage (HIBD) and the therapeutic mechanism of mannitol.Method Healthy and 7-day-old SD rats were randomly assigned into three groups:sham-operated group,HIBD group and mannitol group.Both HIBD and mannitol group were established on HIBD model.The mannitol group was given mannitol intraperitoneally at 0,24,48 h of HIBD.2 ml/kg of 2％ Evans blue (EB) were injected intraperitoneally before sacrifice.0,6,12,24,48 and 72 h after HIBD,the outcomes were analyzed including the brain water content,the expression of AQP 9 mRNA measured using RT-PCR and immunofluorescence staining methods,and the permeability of blood-brain barrier (BBB) measured with EB.Result In HIBD group,the brain water content was higher comparing with sham-operated group at 0 h after HIBD(P ＜ 0.05),and gradually increased over time,reaching peak at 48 h (89.3％ ± 1.9％) and then decreased.In mannitol group,brain water content started to decrease from 1 h after mannitol administration to the bottom at 12 h (86.5％ ±0.6％),then increased to peak at 72 h (87.2％ ± 1.7％),and brain water content were decreased during 0 ～ 48 h comparing with HIBD group.HIBD group's EB were higher than sham-operated group (P ＜ 0.05);Mannitol group's EB were decreased comparing with HIBD group (except 0 h,P ＜ 0.05).AQP 9 mRNA expression in the HIBD group was decreased at 0 h,and reached the bottom at 48 h (0.09 ± 0.07).Comparing with sham-operated group,it was higher in the HIBD group at0,6,72 h,and lower (P＜ 0.05) at 12,24,48 h.Higher AQP 9 mRNA expression were detected in mannitol group than HIBD group and sham-operated group at each time point (with the exception of 48 h) (P ＜ 0.05).AQP 9,which was closely related to water metabolism,were widely found in the pia mater and ependyma using immunofluorescence staining.After ischemia and hypoxia insult,an increasedecrease-increase pattern of AQP 9 expression was found.Conclusion AQP 9 is widely existed in various parts of the brain,influencing brain edema through a variety of pathways.AQP 9 also plays a role in alleviating brain edema in mannitol therapy.

OBJECTIVETo investigate the antibacterial activity of silver sulfadiazine (SD-Ag), mupirocin, and clotrimazole used alone or in combination against methicillin-resistant Staphylococcus aureus (MRSA) isolated from burn wounds.

METHODSEighteen MRSA isolates from wound excretion of 18 burn patients hospitalized in our unit from July to December 2011 were collected continuously and non-repetitively. (1) Minimum inhibitory concentration (MIC), 50% MIC (MIC50), and 90% MIC (MIC90) of SD-Ag, mupirocin, and clotrimazole used alone, those of SD-Ag and mupirocin used in combination, and those of SD-Ag, mupirocin, and clotrimazole used in combination to MRSA were determined by checkerboard agar dilution method. (2) Fractional inhibitory concentration (FIC) index was calculated to determine the combined effect of SD-Ag plus mupirocin, and SD-Ag plus mupirocin and clotrimazole. Synergy with FIC index less than or equal to 0.5 or additivity with FIC index more than 0.5 and less than or equal to 1.0 was regarded as effective, and indifference with FIC index more than 1.0 and less than or equal to 4.0 or antagonism with FIC index more than 4.0 was regarded as ineffective. The effective ratio was compared with overall ratio (assumed as 0) by unilateral binomial distribution test.

RESULTSThe MIC, MIC50, and MIC90 of SD-Ag, mupirocin, and clotrimazole used alone against 18 MRSA isolates were respectively 8, 8, 16 µg/mL; 2, 16, 64 µg/mL; 2, 2, 2 µg/mL. MIC of antimicrobial agents used in combination decreased from 3.1% to 50.0% as compared with that of individual agent used alone. Compared with those of single application of SD-Ag and mupirocin, MIC50 of SD-Ag and that of mupirocin both decreased 75.0%, and MIC90 of them decreased 87.5% when SD-Ag and mupirocin were used in combination. Compared with those of single application of SD-Ag, mupirocin, and clotrimazole, MIC50 of SD-Ag, mupirocin, and clotrimazole respectively decreased 75.0%, 87.5%, and 50.0%; MIC90 of them respectively decreased 87.5%, 96.9%, and 50.0% when SD-Ag, mupirocin, and clotrimazole were used in combination. Among the 18 MRSA isolates, the combined effect of SD-Ag and mupirocin was synergic in 9 isolates, additive in 7 isolates, indifferent in 2 isolates, and antagonistic in 0 isolate; the combined effect of SD-Ag, mupirocin, and clotrimazole was additive in 16 isolates, indifferent in 2 isolates, and antagonistic in 0 isolate. There were statistically significant differences between effective ratio and overall ratio of 18 MRSA isolates treated with combined antimicrobial agents (P values all above 0.01).

CONCLUSIONSFor burn wounds at middle and late stages infected with Staphylococcus aureus or Staphylococcus aureus and Fungus, low dose of SD-Ag or combination of above-mentioned antimicrobial agents can effectively control infection and decrease the adverse effect of antimicrobial agents on wound healing.

Adolescent ; Adult ; Aged ; Anti-Bacterial Agents ; administration & dosage ; adverse effects ; pharmacology ; Burns ; microbiology ; Child ; Child, Preschool ; Clotrimazole ; administration & dosage ; adverse effects ; pharmacology ; Drug Therapy, Combination ; Female ; Humans ; Infant ; Male ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; isolation & purification ; Middle Aged ; Mupirocin ; administration & dosage ; adverse effects ; pharmacology ; Silver Sulfadiazine ; administration & dosage ; adverse effects ; pharmacology ; Young Adult

Aristolochic acids (AAs) have long been considered as a potent carcinogen due to its nephrotoxicity. Aristolochic acid I (AAI) reacts with DNA to form covalent aristolactam (AL)-DNA adducts, leading to subsequent A to T transversion mutation, commonly referred as AA mutational signature. Previous research inferred that AAs were widely implicated in liver cancer throughout Asia. In this study, we explored whether AAs exposure was the main cause of liver cancer in the context of HBV infection in mainland China. Totally 1256 liver cancer samples were randomly retrieved from 3 medical centers and a refined bioanalytical method was used to detect AAI-DNA adducts. 5.10% of these samples could be identified as AAI positive exposure. Whole genome sequencing suggested 8.41% of 107 liver cancer patients exhibited the dominant AA mutational signature, indicating a relatively low overall AAI exposure rate. In animal models, long-term administration of AAI barely increased liver tumorigenesis in adult mice, opposite from its tumor-inducing role when subjected to infant mice. Furthermore, AAI induced dose-dependent accumulation of AA-DNA adduct in target organs in adult mice, with the most detected in kidney instead of liver. Taken together, our data indicate that AA exposure was not the major threat of liver cancer in adulthood.