Resistance, molecular epidemiology and virulence gene of non-A-F group serotype isolates of Salmonella enterica enteric subspecies isolated from children / 中华检验医学杂志

Objective:To analyze the anti-drug resistance, molecular epidemiology and virulence gene distribution of non-A-F group serotype isolates of Salmonella enterica enteric subspecis, so as to provide epidemiological basis for clinical diagnosis and treatment.Methods:Serotyping, antimicrobial susceptibility test and whole genome sequencing were performed on 11 isolates of non-A-F group serotype isolates of Salmonella enterica enteric subspecies that were isolated from The Children′s Hospital, Zhejiang University School of Medicine between 2017 and 2020. The serotype, multilocus sequence typing and virulence gene of the whole genome sequencing results were analyzed. Results:In our hospital, the detection rate of non-A-F group serotype isolates of Salmonella enterica enteric subspecies was low (1.13%). Among the 11 strains, there were 3 strains belong to Jangwani serotype, 2 strains of Hvittingfoss serotype, and Wandsworth, Pomona, Kedougou, Urbana, Poona and Kumasi serotypes have 1 strain each. Except for the two multi-drug resistant strains, the other strains were sensitive to most antibiotics, and the MICs were at low levels. A total of 9 ST types were detected in the 11 strains, the 3 Jangwani serotype strains were ST3918, and the other isolates were of different ST types. The phylogenetic tree shown that the three strains of Jangwani serotype were closely related. A total of 103 virulence genes were detected in the 11 strains, including 78 genes related to secretion system, 21 genes related to adherence, 2 genes related to magnesium uptake, 1 gene related to resistance to antimicrobial peptides and 1 gene related to typhoid toxin. Conclusions:The detection rate of the non-A-F group serotype isolates of Salmonella enterica enteric subspecies was low, and the sensitivity of the isolates to common antibiotics was high. The ST types and genetic relationship showed diversity. Clinical laboratory should pay attention to the detection of the non-A-F group serotype isolates of Salmonella enterica enteric subspecies, and the changes in drug resistance and virulence genes of the isolates should be closely monitored.

Distribution of pathogen species in cerebrospinal fluid culture from 2007 to 2019 / 中华检验医学杂志

Objective:To investigate the distribution of pathogen species isolated from cerebrospinal fluid culture (CSF) in children and analyze the antibiotic-resistance of the main isolates in vitro, which provides reference for interpreting the pathogens and choosing antibiotics in empiric therapy for pediatric patients. Methods:The results of cerebrospinal fluid culture were collected by checking laboratory information system of the Children′s Hospital of Zhejiang University and the clinical characteristics of these children were analyzed retrospectively by checking electronic medical record system.Results:A total of 1 312 isolates were detected, including 1 294 isolates of bacteria and 18 isolates of fungi. A total of 497 (37.9%) isolates were pathogenic microorganisms, of which 288 (57.9%) isolates were gram-positive, 200 (40.3%) isolates were gram-negative, and 9 (1.8%) isolates were fungi. The top 5 pathogens were Escherichia coli (102 isolates, 20.5%), Streptococcus pneumoniae (64 isolates, 12.9%), Streptococcus agalactiae (52 isolates, 10.5%), Enterococcus faecium (33 isolates, 6.6%) and Staphylococcus aureus (28 isolates, 5.6%). Most of the Streptococcus pneumoniae strains were isolated from children more than 1 year old (76.6%, 49/64), while the other top 4 bacteria were mainly isolated from infants less than 1 year old, with the rate of 95.1%(97/102) for Escherichia coli, 98.1%(51/52) for Streptococcus agalactiae, 81.8%(27/33) for Enterococcus faecium and 71.4% (20/28) for Staphylococcus aureus. A total of 815 (62.1%) isolates were considered to be contaminated pathogens according to the analysis on clinical manifestations and other laboratory findings in CSF, and coagulase-negative Staphylococcus (680 isolates), Micrococcus (50 isolates), Corynebacterium (28 isolates) and Enterococcus faecium (23 isolates), which accounted for 41.1% (23/56) of the total detected Enterococcus faecium, were the top 4 contaminated bacteria. During the study period, the isolation rate of the pathogenic microorganisms increased year by year (χ2=34.84, P<0.001), while the isolation rate of the contaminated pathogens, which detected mainly in summer and autumn, decreased year by year (χ2=13.26, P<0.001). Conclusions:The predominant bacteria causing pediatric purulent meningitis were Escherichia coli, Streptococcus pneumoniae, Streptococcus agalactiae, Enterococcus faecium and Staphylococcus aureus. Coagulase-negative Staphylococcus, Micrococcus, Corynebacterium and Enterococcus faecium were common contaminated bacteria in CSF culture, therefore clinicians should interpret the results of CSF culture cautiously according to the bacterial species and clinical manifestations.

Prevention and consideration for the biosafety of laboratory testing under epidemic condition / 中华检验医学杂志

Laboratory testing plays an important role in the diagnosis and treatment of patients with Novel Coronavirus pneumonia. However, the lack of understanding of the virus in the early stage led to great difficulties in biosafety protection for clinical laboratories. Based on the latest researches and findings about the virus, this paper provides some personal opinions on the biosafety prevention in clinical laboratorians under epidemic condition for the reference of laboratory workers.

Genetic background of human lactoferrin transgenic goats / 生物工程学报

The genetic background such as copy number, integration site and chromosome karyotype of exogenous genes of transgenic animals obtained by random integration is still unclear. There may be some problems such as silent integration, invalid integration, toxic integration and unpredictable expression level of exogenous genes. In this study, six primary (F0) and their corresponding offspring (F1) of human lactoferrin (hLF) transgenic goats were selected as the research objects, and blood samples were collected from jugular vein and DNA were extracted. The genetic background and expression level of exogenous genes were studied by chromosome karyotype analysis, real-time quantitative PCR (qPCR), ELISA and Western blotting. The chromosomes of six F0 transgenic goats had no obvious morphological variation, number change and other abnormalities. The relative copy number was different (2-16) and could be steadily inherited to the next generation. The copy number of F0 and F1 hLF gene was the same. The highest expression level of hLF was 1.12 g/L in F1 transgenic goats (L3-1, 8 copies). The results proved that the integrated exogenous genes could steadily inherit the next generation, and did not cause obstacles to the growth and development of transgenic goat individuals. Moreover, there was no obvious correlation between the number of copies and the expression level of hLF. This laid a foundation for the new varieties cultivation of transgenic goats and other transgenic animals, and analysis of genetic background.

Prevention and consideration for the biosafety of laboratory testing under epidemic condition / 中华检验医学杂志

Laboratory testing plays an important role in the diagnosis and treatment of patients with novel coronavirus pneumonia. However, the lack of understanding of the virus in the early stage led to great difficulties in biosafety protection for clinical laboratories. Based on the latest researches and findings about the virus, this paper provides some personal opinions on the biosafety prevention in clinical laboratorians under epidemic condition for the reference of laboratory workers.

Survey on the concept and practice of antiplatelet therapy to prevent cardiovascular diseases among community general practitioners in 11 cities of China / 中华全科医师杂志

Objective:To assess the concept and clinical practice of general practitioners in community health service centers (CHCs) on the use of antiplatelet drugs (APD) to prevent cardiovascular diseases(CVD).Methods:Based on the eastern, western, southern and northern regions of the country, 350 CHCs were selected from 11 cities across the country with stratified sampling method for study sites, and one general practitioner was selected from each CHC. The questionnaire survey was conducted from March 12 to April 20, 2018 among 350 participants. The content of the questionnaire included the situation of CVD patients, application of APD in primary/secondary prevention of CVD (schemes and regimes), the prescription concept of APD, and influencing factors.Results:Total 350 valid questionnaires were recovered. The survey showed that among all patients general practitioners routinely took care, 46% (30%, 60%) were hypertensive patients; 96.6% (338/350) of the general practitioners said that they had carried out primary prevention, mainly for patients with hypertension, diabetes, dyslipidemia or carotid artery plaque, and 34% (20%, 45%) of the patients had taken primary prevention drugs; the use of APD only accounted for 47% (35%, 60%) , among which 87% (80%, 95%) was aspirin. The main impediments were lack of awareness of disease from patients[ (8.0±1.4) points] and lack of awareness of primary prophylaxis from general practitioners[ (7.3±1.4) points]. The survey also showed that 28% (20%, 35%) and 17% (10%, 20%) patients were diagnosed as coronary heart disease and stroke, respectively; 83% (80%, 95%) of patients with coronary heart disease or stroke used APD for secondary prophylaxis; for coronary heart disease patients, 82% (70%, 95%) taking aspirin or clopidogrel, 18% (5%, 30%) taking aspirin and clopidogrel for 11 months; for stroke patients, 85% (80%, 95%) taking aspirin or clopidogrel, 15% (5%, 20%) taking aspirin and clopidogrel for 9 months. Compared with clopidogrel, aspirin had a relatively high score for clinical experience (8.3±1.1) and reasonable cost of treatment (8.3±1.3) .Most coronary heart disease patients (68%±15%) and stroke patients (70%±17%) took APD regularly. The lack of knowledge of disease [(8.4±1.1) points] and awareness of regular medication [(8.2±1.2) points] were the main factors affecting compliance of patients.Conclusion:The use of APD in primary prevention of CVD for general practitioners is insufficient, and there is still a big gap between the standardization and the practice in secondary prevention; in particular, the selection of APDs and treatment course should strictly follow the guidelines.

Survey on concept of antihypertensive therapy and hypertension management among general practitioners in community health centers in 11 cities of China / 中华全科医师杂志

Objective:To survey the status of antihypertensive therapy knowledge and hypertension management among general practitioners in community health centers (CHCs) in China.Methods:Based on the eastern, western, southern and northern regions of the country, 350 CHCs were selected from 11 cities across the country with stratified sampling method for study sites, and one general practitioner was selected from each CHC. The questionnaire survey was conducted from March 12 to April 20, 2018 among 350 participants. The content of the questionnaire included the proportion of hypertensive patients in the consultation, treatment target rate, antihypertensive drugs and protocol, the medication compliance, follow-up, blood pressure self-measurement, and the impact of hierachical medical system on CHC.Results:Total 350 valid questionnaires were recovered. The survey showed that: (1) Among the patients treated by general practitioners, 46% (30%, 60%) were hypertensive patients including 41% (40%, 55%) with primary hypertension and 42% (40%, 50%) with secondary hypertension; 72% (60%, 80%) of the patients had comorbidities, including dyslipidemia, diabetes, and coronary heart disease. (2) Western medicine was the main antihypertensive treatment [90% (82%, 100%) ], calcium channel blockers were the most commonly used antihypertensive drug [46%(30%,60%)], the therapeutic protocol was mainly single agent [35% (25%, 50%) ]or free combination [50% (40%, 60%) ]; the stable(9.1±0.8), long-acting (9.0±0.9) and high standard reaching rate (8.1±1.1) antihypertensive drugs were first considered, and the standard reaching rate of hypertension treatment was 61% (50%, 75%) . (3) The regular follow-up rate, adherence to blood pressure self-test rate and long-term regular medication rate was 60%(50%,70%), 51%(40%,70%) and 65%(50%,70%), respectively. The factors affecting patients′ compliance were history of cardiovascular diseases (8.4±1.1)and patients′ cognition of disease(8.3±1.1). General practitioners believed that the positive effects of the hierarchical diagnosis and treatment system include helping to establish a closer relationship with patients [62.6% (219/350)] and improving patient compliance for community preferential reimbursement policies[58.6% (205/350) ]. The challenges faced by CHC included higher patient expectations [52.8% (185/350)] and increased outpatient visits [52.6% (184/350)]. Insufficient diagnostic equipment [68.3% (239/350)], inadequate dispensing [52.3% (183/350)] and other issues restricted the development of CHC, and the clinical competence of general practitioners [51.7% (181/350)] need to be improved.Conclusion:Patients with hypertension account for about half of the total number of visits in community health service centers, and most of them are comorbid with cardiovascular and cerebrovascular diseases or risk factors. The long-term treatment compliance and self-management of blood pressure need to be further improved.

Clinical efficacy of a narrow pedicle cross-finger flap in treatment of distal fingertip degloving injuries / 中华医学美学美容杂志

Objective To investigate the application of a narrow pedicle cross-finger flap in the treatment of fingertip degloving injuries.Methods Between June 2011and May 2013,23 patients (23 fingers) suffered from fingertip degloving injuries were treated with a narrow pedicle cross-finger flap.There were 15 males (15 fingers) and 8 females (8 fingers).Defects were caused by machine crush injury in 11 cases,girdle crush injury in 7 cases and punch press injury in 5 cases.The defects were located on the index finger in 10 cases,long finger in 2 cases,ring finger in 7 cases,and little finger in 4 cases.The flaps sized 2.6 cm × 1.9 cm to 6.5 cm × 2.2 cm.After six months,according to Zhang's curative effect satisfaction score method,the efficacy of the treatment was evaluated by five aspects of skin flap healing:flap fleeing,skin flap,flap outline,flap temperature and donor site scar.Results The island flaps were survived completely in 23 patients.After followed-up for 6 to 18 months (one case was lost to follow-up).The color and texture of the flap were the same to the surrounding normal skin,and the finger shape was satisfactory.There was no pigmentation and contraction relapse ofthe injured finger.The mean values of static 2-point discrimination were (6.1 ± 1.3) mm (range,5-8 mm) of the flap.Conclusions The narrow pedicle cross-finger flap can be used to repair the fingertip degloving injuries with the flexible flap design and reliable blood supplement.The flap survives well and the repair area is good.Therefore,it is a good method and strongly recommended for fingertip degloving injuries repair in clinics.

Clinical characteristics and antimicrobial resistance of pneumococcal infections from 9 children's hospitals in 2016 / 中华儿科杂志

Objective@#To describe the clinical characteristics of pneumococcal infections and drug resistance of Streptococcus pneumoniae isolates from children's hospitals, which would provide reference for preventing and treating pneumococcal diseases.@*Methods@#This was a prevalence survey. In this study, the age, specimen type, monthly distribution characteristics, and antimicrobial resistance of Streptococcus pneumoniae isolates from 9 children's hospitals in China were investigated between January 1, 2016 and December 31, 2016. The WHONET 5.6 software was used to analyze the antibiotic susceptibility of Streptococcus pneumoniae. The comparison of rates was performed by Chi-square test.@*Results@#A total of 6 200 isolates of streptococcus pneumoniae were obtained, namely, 95.1% (5 876/6 177) from the respiratory tract specimens, 2.2% (136/6 177) from blood specimens and 0.4% (24/6 177) from cerebrospinal fluid specimens. The isolates were mainly from children older than 1 and younger than 5 years (54.7%, 3 381/6 185) . Most of strains (33.2%, 1 184/3 563) were isolated in November, December and January. Streptococcus pneumoniae isolates were completely sensitive to vancomycin (100.0%, 6 189/6 189) , linezolid (100.0%, 6 030/6 030) , moxifloxacin (100.0%, 3 064/3 064) , highly sensitive to levofloxacin (99.8%, 5 528/5 540), ertapenem (98.8%, 3 024/3 061) and lowly sensitive to erythromycin (1.7%, 102/6 016), clindamycin (3.7%, 116/3 136), and tetracycline (5%, 244/4 877), respectively. According to the parenteral susceptibility breakpoints for non-meningitis isolates, the sensitivity of Streptocococus pneumoniae to penicillin from children's hospital of Chongqing Medical University (49.3%, 892/1 809) was significantly lower than those of other hospitals (χ2=1 268.161, P<0.05) .@*Conclusions@#Streptococcus pneumoniae is mainly isolated from respiratory tract, from children older than 1 and younger than 5 years and during November to January in tertiary children's hospital of China. The Streptococcus pneumoniae from children is highly sensitive to vancomycin, linezolid, moxifloxacin, levofloxacin. There are also significant differences in the sensitivity of penicillin for Streptococcus pneumoniae from different hospitals.

Knowledge,attitude and practice related to schistosomiasis control among rural residents in Wanjiang River region after a flood / 中国血吸虫病防治杂志

Objective To investigate the status of knowledge,attitude and behavior of schistosomiasis control of rural resi-dents in Wanjiang River region after a flood,so as to provide the reference for targeted health education. Methods The multi-stage sampling was applied to select the respondents in rural residents in Wanjiang River region,and the self-designed question-naire was used to investigate the current situation of knowledge,attitude and behavior of schistosomiasis prevention and control of the rural residents. Results The total awareness rate of knowledge about the prevention and control of schistosomiasis was 47.92%. The age,education,family income,relatives and friends with medical background,and health education significantly influenced the awareness rate(χ2=12.76,89.19,18.19,50.83 and 92.60 respectively,all P<0.05). The accuracy rates of at-titude and behavior in schistosomiasis control were 62.89%and 52.37%respectively. Conclusion The awareness rate of knowl-edge about the prevention and control of schistosomiasis,and the accuracy rates of attitude and behavior in schistosomiasis con-trol of the rural residents in Wanjiang River region are all inefficient,and therefore,the targeted health education should be strengthened to decrease the risk of schistosomiasis transmission.

Efficacy of full ankle arthroscopy in treatment of Tillaux-Chaput fractures / 中华创伤杂志

Objective To investigate the clinical result of treating Tillaux-Chaput fractures using the full ankle arthroscopy technique.Methods A retrospective analysis was made on 21 patients with Tillaux-Chaput fractures followed up after treatment by the full ankle arthroscopy technique from May 2013 to May 2015.There were 16 males and 5 females,with the age range of 6-55 years [(25.5 ± 12.8)years].Right ankle was involved in 12 patients and left ankle in 4 patients.Sixteen patients had single TillauxChaput fractures and 5 patients had combined proximal fibular fractures.Diagnosis of Tillaux-Chaput fractures was confirmed by X-rays in 18 patients an CT in 3 patients.Ankle arthroscopy was used through the anterolateral and anteriormedal approaches for closed reduction and internal fixation using one or two Herbert screws.Wound healing,bone union and visual analogue score (VAS) were detected postoperatively.Function assessment was performed using the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scoring system.Results All incisions healed by first intention,without evidence of nerve,vessel and tendon injuries.Period of follow-up was (15.3 ± 7.1) months (range,12-25 months).Fracture healed within 12 to 36 weeks [(22.6 ±4.6)weeks] after operation.VAS was (0.8 ± 0.3) points after operation,obviously lower than preoperative (8.3 ± 1.3) points (P ＜ 0.05).At the final follow-up,all patients regained normal ankle function and normal walking gait,without the presence of ankle pain and weight-bearing walking pain.AOFAS score was improved from preoperative (51.2 ± 12.5) points to postoperative (92.7 ± 16.5) points (P ＜ 0.05).Based on the AOFAS score,the results were excellent in 19 patients and good in 2 patients,with the excellent-good rate of 100％.Conclsion Full ankle arthroscopy by the anterolateral and anterionnedal approaches provides a precise and effective method for closed reduction and internal fixation of Tillaux-Chaput fractures and deserves clinical application.

Proximal dorsal digital artery pedicled island flaps for reconstruction of adjacent finger soft-tissue defect / 中华创伤杂志

Objective To assay the clinical effect of proximal dorsal digital artery pedicled island flap in treatment and sensory reconstruction of adjacent finger soft-tissue defect.Methods The study enrolled 21 cases of soft-tissue defect in 21 fingers treated from January 2013 to January 2014.All the defects were covered with the proximal dorsal artery pedicled island flaps raised from the adjacent finger.Index finger was injured in 7 patients,middle finger in 9 patients,ring finger in 4 patients,and little finger in 4 patients.Defect and flap dimensions varied from 1.9 cm × 1.5 cm to 4.3 cm × 2.3 cm and from 2.0 cm × 1.7 cm to 4.5 cm × 2.5 cm respectively.Donor site was resurfaced with a fullthickness skin harvested from medial side of the upper arm.Postoperative flap appearance and two-point discrimination were evaluated.Total active motion (TAM) of the finger was evaluated after operation.Results All the flaps and skin grafts survived after operation.Duration of the follow-up was 6-18 months (mean,14.7 months).Through the final follow-up,appearance and function of the flap were satisfactory,donor site healed well,and two-point discrimination was 5-9 mm (mean,6.3 mm).TAM evaluation was excellent in 19 patients and good in 2 patients with the excellent-good rate of 100％.Conclusion The proximal dorsal artery pedicled island flap raised from the adjacent finger is an ideal choice in finger soft-tissue reconstruction,for the technique has advantages of high survival rate,satisfactory appearance and sensory function as well as few complications.

Effect of Acupuncture on HDAC2 Activity in Peripheral Blood of COPD Rats / 世界科学技术-中医药现代化

This article was aimed to explore the effect of acupuncture on HDAC2 activity in peripheral blood of chronic obstructive pulmonary disease (COPD) rats. The COPD rat model was established by cigarette smoking. Acupuncture was given for 3 consecutive weeks. The lung ventilation of rat was detected by equipment. Peripheral blood of rat was taken after 3 weeks. The HDAC2 enzyme activity was detected by fluorescence technology. ELISA was used in the detection of IL-10, IL-8 and TNF-αexpression in peripheral blood. The results showed that after acupuncture treatment, the lung ventilation was obviously increased compared with the model group (P < 0.05). Meanwhile, the HDAC2 activity in the peripheral blood of rat was obviously increased (P < 0.05). However, the expression of inflammatory cytokines IL-10, IL-8 and TNF-α was obviously reduced (P < 0.05). It was concluded that acupuncture treatment had a good efficacy on COPD rat. It indicated that acupuncture treatment might regulate HDAC2 activity to reduce inflammation.

Efficacy observation on repair of finger pulp defects and sensory reconstruction of children with the perforator propeller flaps based on the end dorsal branch of digital proper artery in the same finger / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the clinical outcomes of the use of the perforator propeller flaps based on the end dorsal branch of digital proper artery in the same finger in repair of finger pulp defects and sensory reconstruction in children.</p><p><b>METHODS</b>Twenty-three children (31 fingers) with index, middle, ring or little finger pulp defects were hospitalized from September 2012 to December 2013. The area of finger pulp defects ranged from 1.2 cm × 1.0 cm to 2.0 cm × 1.5 cm. The perforator propeller flaps based on the end dorsal branch of digital proper artery in the same finger were used to repair the defects, with the flap size ranging from 1.3 cm × 1.2 cm to 2.2 cm × 1.6 cm. The dorsal branch of the digital proper nerve of the flap was conducted end-to-end anastomosis with the broken end of the nerve of the wound to reconstruct sensation. The donor sites were covered with autologous full-thickness skin obtained from inner aspect of the thigh.</p><p><b>RESULTS</b>Primary healing of the wounds and donor sites were achieved in all 23 children. All the flaps and skin grafts of donor sites survived. All the patients were followed up for 6 to 20 months, with mean time of 14 months. At the last follow-up, the flaps and donor sites were in good appearance, the finger pulps were mellow and plump, with no obvious pigmentation or cicatricial contracture. The sensation of finger pulps reached S3(+), and the distance of two-point discrimination ranged from 4.5 to 6.0 mm, with mean distance of 5.1 mm. Twenty-one parents of the patients were strongly satisfied with the appearance of the repaired fingers, and the other 2 parents also expressed satisfaction.</p><p><b>CONCLUSIONS</b>Transplantation of the perforator propeller flap based on the end dorsal branch of digital proper artery in the same finger is a safe and reliable method for the repair of index, middle, ring, and little finger pulp defects and sensory reconstruction of children. The flaps are with good blood supply, appearance and sensory function after operation.</p>

Detection of a new qnrA7 genotypes in Shewanella algae / 中华微生物学和免疫学杂志

Objective To research the distribution and the characteristics of the plasmid mediated quinolone resistant genes in Shewanella algae. Methods The qnr, qepA, aac(6')-Ib-cr genes were amplified by PCR, then the positive PCR products were sequenced to determine the gene type. The transferability of plasmid mediated quinolone resistance was ensured by conjugation experiment. MICs were measured by E-test. qnrA gene was mapped to plasmids to locate it. Results The qnrA gene were detected in the Shewanella algae, this is a newfound subgroup qnrA7, the GenBank accession no. was GQ463707, qnrB, qnrS,qnrC, qnrD, qepA and aac(6')-Ib-cr genes were not detected. qnrA7 reside in a plasmid about 33 kb, conjugation experiment was unsuccessful. The strain was susceptible to quinolones. Conclusion It deserves paying close attention to the report of an original qnrA subgroup in an isolate of water-borne species of Shewanella algae.

Sequence analysis of plasmid in Klebsiella pneumoniae KF3 / 中华微生物学和免疫学杂志

Objective To study the structures of the plasmids of Klebsiella pneumoniae KF3 at the genome metagenome level througth with whole plasmid DNA sequencing, to analyze the functional genes carried by plasmid and to identify the correlation of resistance and pathogenicity between the plasmids and the host strains. Methods The alkaline lysis method was used to extract plasmids. We constructed the small insert pUC18 library and the large insert Forsmid library, sequenced and used the Phred / Phrap / Consed package to assemble these sequences and gained a complete sequence. The open reading frame(ORFs) were predicted by the Glimmer software and annotated, analyzed the functions of these genes. Results We successfully constructed the pUC18 library and the Fosmid libraries for the plasmid DNA and obtained three circular double-stranded DNA plasmids: pKF3-70 (69 477 bp), pKF3-90 (91 327 bp) and pKF3-147 ( 147 416 bp). There were drug resistant genes, conjugative transfer genes and mobile DNA elements identified on three plasmids. Conclusion The three plasmids of KF3 could be transferred among different strains. It would lead to the dissemination of the resistant genes.

The Monolayer Culturing of The Neural Stem Cell Clone and Its Qualification / 生物化学与生物物理进展

The primary neural stem cells were isolated from SD rat and formed the neuropheres, the neuropheres were passaged and planted on the dish coated with 0.1% gelatin, the colony was picked up under the microscope, then dispersed and cultured, to obtain the clone proliferated from one cell, passaging and picking up the cells 5～6 times at least. The NSC and its differentiated cells were identified with the marker genes respectively. The results showed that the neural stem cells were isolated from the SD rat embryos and the real clone were obtained by picking up the cells again and again, and then cultured in the form of monolayer. The marker genes of the neural stem cells and its differentiated cells could be detected at last. It will provide the rat model the resource of the cells for the treatment and the basic research for the morphology standard.

Nerve regeneration factor promotes nerve regeneration after sciatic nerve injury in rats / 第二军医大学学报

Objective:To investigate the promoting effect of nerve regeneration factor(NRF) on nerve regeneration after sciatic nerve injury in rats.Methods: Thirty Sprague-Dawely rats,including 15 females and 15 males,were equally randomized into 3 groups: low dose NRF group,high dose NRF group and control group.Rats' sciatic nerves were injured by crushing and sciatic function index(SFI) was determined by walking tract analysis at days 10,15 and 20 after crushing.Then sciatic nerves on both sides were dissociated for electrophysiology study and the recovery rate of nerve conduction velocity(NCV) was calculated.Then,2 rats were randomly selected from each group and the ultrastructure of regenerated sciatic nerves was observed by electron microscope.Meanwhile,the spinal cord segments(L_4-L_6),the distal site of injured sciatic nerve and the injured gastrocnemius muscle in other rats were observed by light microscope.The count of motor neurons of anterior horn,the number of myelinated fibers,the transverse section area of gastrocnemius muscle cells and other parameters were determined.Results: At day 10 after crushing,SFI scores had no significant difference between 3 groups;at day 15 after crushing,SFI score of high dose NRF group was significantly higher than that of the control group(P