微酸性次氯酸水用于口腔综合治疗台水路消毒的研究

目的　检测不同浓度微酸性次氯酸水（slightly acidic hypochlorite water,SAHW）应用于口腔综合治疗台水路（dental unit waterlines,DUWLs）的消毒效果。方法    选取32台口腔综合治疗台（dental chair unit,DCU）,随机均分为4组（1个对照组和3个实验组,每组8台DCU）。首先,采集高速手机和三用枪基础水样行细菌培养、菌落计数;然后,实验组分别用有效氯含量8 ~ 12 mg/L（实验1组）、18 ~ 22 mg/L（实验2组）、28 ~ 32 mg/L（实验3组）的SAHW供水DUWLs,连续7 d采集高速手机和三用枪水样行细菌培养、菌落计数。第8 d始改用无菌蒸馏水（distilled water,DW）供水DUWLs后采集水样菌落培养计数;对照组用DW替代消毒水,同样程序流动冲洗DUWLs后收集高速手机和三用枪水样菌培养后菌落计数。数据采用SPSS 20.0软件进行统计分析。结果    与基础水样比较,SAHW消毒1 d,3个实验组的高速手机和三用枪水样菌落计数均显著下降（P < 0.05）;SAHW消毒2 d,实验3组高速手机和三用枪水样菌落计数均小于消毒合格水样上限值（100 CFU/mL）;SAHW消毒3 d开始,实验3组菌落计数为0 CFU/mL,实验1组和2组菌落计数均显著小于100 CFU/mL。更换为DW供水后1 ~ 2 d,3个实验组的高速手机和三用枪水样菌落计数维持小于100 CFU/mL,组间差异无统计学意义（P > 0.05）;3 ~ 7 d,3个实验组的高速手机和三用枪水样菌落计数持续增加（149 ~ 1014 CFU/mL）,实验1、2、3组的组内不同时间点检测数据比较差异均有统计学意义（均P < 0.05）,且均明显大于合格水样上限值（P < 0.05）。结论    高有效氯含量较低有效氯含量的SAHW消毒效果更稳定;低有效氯含量8 ~ 12 mg/L的SAHW持续作用于DUWLs内环境亦可有效控制菌落计数,消毒效果明显。     

In vitro selection and characterization of resistance to macrolides and related antibiotics in Mycoplasma pneumoniae

Macrolide-resistant mutants of Mycoplasma pneumoniae were selected in vitro from the susceptible reference strain M129, by 23 to 50 serial passages in subinhibitory concentrations of macrolides and related antibiotics, erythromycin A, azithromycin, josamycin, clindamycin, quinupristin, quinupristin-dalfopristin, pristinamycin, and telithromycin. Mutants for which the MICs are increased could be selected with all antibiotics except the streptogramin B quinupristin. Portions of genes encoding 23S rRNA (domains II and V) and ribosomal proteins L4 and L22 of mutants were amplified by PCR, and their nucleotide sequences were compared to those of the susceptible strain M129. No mutation could be detected in domain II of 23S rRNA. Two point mutations in domain V of 23S rRNA, C2611A and A2062G, were selected in the presence of erythromycin A, azithromycin, josamycin, quinupristin-dalfopristin, and telithromycin. Mutants selected in the presence of clindamycin and telithromycin harbored a single amino acid change (H70R or H70L, respectively) in ribosomal protein L4, whereas insertions of one, two, or three adjacent glycines at position 60 (M. pneumoniae numbering) were selected in the presence of both streptogramin combinations. Telithromycin was the sole antibiotic that selected for substitutions (P112R and A114T) and deletions ((111)IPRA(114)) in ribosomal protein L22. Three sequential mutational events in 23S rRNA and in both ribosomal proteins were required to categorize the strain as resistant to the ketolide. Azithromycin and erythromycin A were the only selector antibiotics that remained active (MICs, 0.06 and 1 micro g/ml, respectively) on their mutants selected after 50 passages.     

三七总皂苷对大鼠心肌肥厚的保护作用

目的:研究三七总皂苷(total saponins of panax notoginseng, PNS)对异丙肾上腺素所致大鼠心肌肥厚的保护作用.方法:背部皮下注射用异丙肾上腺素(isoproterenol, ISO)5 mg/(kg·d),连续7 d,建立大鼠心肌肥厚模型.造模第二天开始给大鼠腹腔注射PNS 25和50 mg/(kg·d),连续14 d,测定全心重量指数(HW/BW),左心室重量指数(LVW/BW即LVI);采用试剂盒用分光光度法检测左心室心肌组织中羟脯氨酸(Hyp)和一氧化氮(NO)含量;用放免分析法检测左心室心肌组织中血管紧张素Ⅱ(AngⅡ)含量.结果:ISO模型组大鼠的HW/BW、LVI明显升高;左心室HyP、AngⅡ含量增高,NO水平下降.PNS能明显提高心肌组织NO水平,降低胶原的含量,抑制AngⅡ产生,使HW/BW及LVI下降,抑制心肌肥厚.结论:PNS对ISO所致大鼠心肌肥厚具有保护作用.     

温莪术内生真菌的分离及其抗菌活性的初步研究

 目的研究温莪术内生真菌的种群组成及其代谢产物抗菌活性。方法采用内生菌常规分离法对健康温莪术植株体内的内生真菌进行了分离鉴定。以大肠杆菌、金黄色葡萄球菌、链球菌、沙门氏菌、巴氏杆菌为测试菌种,对温莪术根、茎、叶中分离的56株内生真菌进行抗菌活性筛选。结果经初步鉴定,这些内生真菌为5目、6科、24属;抑菌实验表明,56株内生真菌中有39株对5种测试菌均有不同程度的抑制作用。结论温莪术植物含有丰富多样的内生真菌,且多数内生真菌都表现为较高的抑菌活性。     

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??Value of preoperative lymphoscintigraphy in sentinel lymph node biopsy of breast cancer SUN Xiao*, LIU Juan-juan, WANG Yong-sheng, et al. *Breast Cancer Center, Shandong Cancer Hospital, Jinan 250117, China
Correcponding author: WANG Yong-sheng, E-mail: wangysh2008@yahoo.com.cn
Abstract Objectives Background Although preoperative lymphoscintigraphy for sentinel lymph nodes biopsy (SLNB) in breast cancer patients is undergone commonly, its clinical significance remains controversial. Methods Firstly, a database containing 716 consecutive breast cancer patients who received preoperative lymphoscintigraphy before SLNB was retrospectively analyzed. Secondly, 565 consecutive breast cancer patients were prospectively randomized into groups with or without preoperative lymphoscintigraphy before SLNB. Results In the retrospective study, sentinel lymph nodes (SLNs) were well imaged by lymphoscintigraphy in 86.6% patients, and negative lymphoscintigraphy results were associated with axillary node metastases. Failure of identification of SLNs by isotope alone was associated with whether axillary hot spot was imaged by lymphoscintigram (P<0.001). There were no significant differences in the false negative rate (P=0.731) of SLNB by isotope alone, in the identification rate (P=0.174) and the false negative rate (P=0.947) of SLNB by combination of dye and isotope between patients who had axillary hot spot in lymphoscintigram and those who had not. In the prospective study, 290 patients were randomized into the group with preoperative lymphoscintigraphy (82.1% patients were well imaged by lymphoscintigraphy) and 275 patients without. There were no significant differences between two groups in the identification rate (P=0.757) and the false negative rate (P=1.00) of SLNB by isotope alone, also in the identification rate (P=1.00) and the false negative rate (P=1.00) of SLNB by combination of dye and isotope. Conclusion Preoperative lymphoscintigraphy could not improve the identification rate and reduce the false negative rate of SLNB in breast cancer patients, and it is not a prerequisite for SLNB.     

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??Ultrasound characteristics of thyroid microcarcinoma PAN Fu-shun*??XIE Xiao-yan??LI Xiao-xi??et al. *Department of Ultrasound, the First Affiliated Hospital of Sun Yat-sun University, Guangzhou 510080,China
Corresponding author??XIE Xiao-yan??E-mail??xxy1992@live.cn
Abstract Objective To investigate the ultrasound characteristics of thyroid microcarcinoma. Methods The ultrasound imaging of thirty-four cases of thyroid microcarcinoma confirmed by surgery and pathology between January 2003 and January 2009 at the First Affiliated Hospital of Sun Yat-sun University was analyzed retrospectively. Results Thirty-two (94.1%) cases were detected as hypo-echo nodules. Twenty-eight (85.3%) cases were with irregular shape. Twenty-six (76.5%) cases were with irregular edges calcification. Blood flow was detected in 7 cases with CDFI and lymph node metastasis was found in 4 cases. Conclusion Hypo-echo nodules, regular shape, irregular edges and calcification are the ultrasound characteristic. Comprehending the characteristics may improve the pre-operation diagnosis efficacy.