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范高阳王业忠许晖刘祺姬云翔赵冬 《现代生物医学进展》2011,11(20):3860-3863
目的:建立一种可重复的、有典型神经损伤症状的自发性蛛网膜下腔出血(SAH)动物模型,为研究蛛网膜下腔出血后早期脑损伤(EBI)的机制提供可靠的动物模型。方法:选用新西兰大耳白兔60只,随机分为实验组、对照组、空白组。采用枕大池穿刺一次注入自体动脉血法建立SAH模型。在4h、8h、12h、24h、48h、72 h时间点,观察比较行为学与脑组织形态学的变化。结果:(1)实验组枕大池和蛛网膜下腔内发现大量的血凝块和血液。(2)实验组光镜下可观察到蛛网膜下腔大量红细胞,神经元细胞水肿,电镜下可见胶质细胞空泡样改变,神经元细胞线粒体肿胀,髓鞘内存在空泡和板层分离现象。(3)实验组造模后均出现明显的神经系统损伤,对照组4h出现典型神经系统损伤表现,12h后恢复正常,空白组未见神经系统损伤表现。结论:枕大池一次注血法是一种简便、可重复的症状性自发性蛛网膜下腔出血早期脑损伤模型,适宜于研究早期脑损伤的致病机制。 相似文献
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Beaufort A Rudelle S Gnanou-Besse N Toquin MT Kerouanton A Bergis H Salvat G Cornu M 《Letters in applied microbiology》2007,44(4):406-411
AIM: To investigate Listeria monocytogenes contamination and behaviour in naturally contaminated French cold-smoked salmon (CSS). METHOD AND RESULTS: Between 2001 and 2004, L. monocytogenes was detected in 104 of 1010 CSS packs, produced by nine French plants, with different prevalence (from 0% to 41%). The initial contamination, measured with a sensitive filtration method, was low (92% of contaminated products below 1 CFU g(-1)) and growth was limited. CONCLUSION: Growth was consistent with results of a predictive model including microbial competition. SIGNIFICANCE AND IMPACT OF THE STUDY: To be included in a quantitative risk assessment. 相似文献
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S. Börjesson A. Matussek S. Melin S. Löfgren P.E. Lindgren 《Journal of applied microbiology》2010,108(4):1244-1251
Aims: (i) To cultivate methicillin‐resistant Staphylococcus aureus (MRSA) from a full‐scale wastewater treatment plant (WWTP), (ii) To characterize the indigenous MRSA‐flora, (iii) To investigate how the treatment process affects clonal distribution and (iv) To examine the genetic relation between MRSA from wastewater and clinical MRSA. Methods: Wastewater samples were collected during 2 months at four key sites in the WWTP. MRSA isolates were characterized using spa typing, antibiograms, SSCmec typing and detection of Panton–Valentine leukocidin (PVL). Conclusions: MRSA could be isolated on all sampling occasions, but only from inlet and activated sludge. The number of isolates and diversity of MRSA were reduced by the treatment process, but there are indications that the process was selected for strains with more extensive antibiotic resistance and PVL+ strains. The wastewater MRSA‐flora had a close genetic relationship to clinical isolates, most likely reflecting carriage in the community. Significance and Impact of the Study: This study shows that MRSA survives in wastewater and that the WWTP may be a potential reservoir for MRSA. 相似文献
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Background: Fine needle aspiration cytology (FNAC) of pancreas is a widely accepted method of diagnosis of pancreatic mass lesions. We have performed a retrospective analysis of all radiological (CT/ultrasound) and endoscopic ultrasound guided procedures at our institution.
Aim: (1) To review the results of FNAC of pancreas from January 2000 to April 2006. (2) To calculate the inadequate rate. (3) To account for discrepancies between the cytological and histological diagnoses. (4) To identify any false positive cases if present.
Method: The results of all pancreatic FNAC reported at our institute from January 2000 to April 2006 were identified from the laboratory system. All results were classified as follows: Inadequate, inconclusive, benign, suspicious and malignant. The results were further categorised depending on whether they were CT/ultrasound guided or EUS guided. The histological diagnosis where available was used as the gold standard and where discrepancies were present the cytological preparations were reviewed.
Results: Seventy-three patients underwent pancreatic FNAC during the study period. Table 1 illustrates our results.
Aim: (1) To review the results of FNAC of pancreas from January 2000 to April 2006. (2) To calculate the inadequate rate. (3) To account for discrepancies between the cytological and histological diagnoses. (4) To identify any false positive cases if present.
Method: The results of all pancreatic FNAC reported at our institute from January 2000 to April 2006 were identified from the laboratory system. All results were classified as follows: Inadequate, inconclusive, benign, suspicious and malignant. The results were further categorised depending on whether they were CT/ultrasound guided or EUS guided. The histological diagnosis where available was used as the gold standard and where discrepancies were present the cytological preparations were reviewed.
Results: Seventy-three patients underwent pancreatic FNAC during the study period. Table 1 illustrates our results.
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彩色多普勒超声对原位肝移植术后血流动力学研究 总被引:1,自引:1,他引:0
目的:探讨彩色多普勒超声(CDI)在原位肝移植术后对移植肝血流动力学变化的诊断价值。方法:应用CDI连续观察6例原位肝移植患者移植肝脏形态学变化,肝动脉峰值流速(HAmax)、门静脉及肝静脉平均流速(PVmean,HVmean)等指标,并以30例健康成人男性肝脏的血流动力学参数作为正常对照组。结果:在术后2周内肝脏移植组的HAmax低于正常对照组,1周内表现更为明显;术后1周内移植肝脏组的PVmean高于正常对照组,1周后表现不明显;移植肝脏组的Hvmean与正常对照组相比无明显差异。2周后,HA、PV和HV的血流速度基本上趋于正常。结论:CDI技术对了解肝移植术后移植肝的灌注情况,及早发现肝移植术后早期的并发症有重要意义。 相似文献
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MOTIVATION: To construct a multiple sequence alignment (MSA) of a large number (> approximately 10,000) of sequences, the calculation of a guide tree with a complexity of O(N2) to O(N3), where N is the number of sequences, is the most time-consuming process. RESULTS: To overcome this limitation, we have developed an approximate algorithm, PartTree, to construct a guide tree with an average time complexity of O(N log N). The new MSA method with the PartTree algorithm can align approximately 60,000 sequences in several minutes on a standard desktop computer. The loss of accuracy in MSA caused by this approximation was estimated to be several percent in benchmark tests using Pfam. AVAILABILITY: The present algorithm has been implemented in the MAFFT sequence alignment package (http://align.bmr.kyushu-u.ac.jp/mafft/software/). SUPPLEMENTARY INFORMATION: Supplementary information is available at Bioinformatics online. 相似文献
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目的:研究尼古丁对Wistar大鼠冠状动脉平滑肌大电导钙激活钾通道(BKca)活性的抑制作用及其细胞信号转导机制。方法:8周雄性Wistar大鼠随机分为两组:生理盐水组和尼古丁组;分别予以生理盐水和尼古丁2mg/(kg.d)注射21 d,蛋白酶法分离冠状动脉血管平滑肌细胞,将两组平滑肌细胞分别以对氯苯硫基环腺苷酸(CPT-cAMP,100μmol/L)和佛司可林(forskolin,10μmol/L)干预,单通道膜片钳记录干预前后平滑肌细胞单通道电流的平均开放时间(To)、平均关闭时间(Tc)、平均开放概率(Po)。结果:CPT-cAMP和Forskolin均能显著延长生理盐水组大鼠BKca的平均开放时间,缩短平均关闭时间,增加通道开放概率(P均<0.01)。对尼古丁组BKca的To、Tc、Po均无明显影响。结论:尼古丁促使冠状动脉血管收缩的生理机制是通过抑制cAMP/PKA途径诱导的大电导钙激活钾通道活性增加实现的。 相似文献
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Brain bank of the Brazilian aging brain study group—a milestone reached and more than 1,600 collected brains 总被引:2,自引:0,他引:2
Grinberg LT Ferretti RE Farfel JM Leite R Pasqualucci CA Rosemberg S Nitrini R Saldiva PH Filho WJ;Brazilian Aging Brain Study Group 《Cell and tissue banking》2007,8(2):151-162
INTRODUCTION: Brain banking remains a necessity for the study of aging brain processes and related neurodegenerative diseases. In the present paper, we report the methods applied at and the first results of the Brain Bank of the Brazilian Aging Brain Study Group (BBBABSG) which has two main aims: (1) To collect a large number of brains of elderly comprising non-demented subjects and a large spectrum of pathologies related to aging brain processes, (2) To provide quality material to a multidisciplinar research network unraveling multiple aspects of aging brain processes and related neurodegenerative diseases. METHODS: The subjects are selected from the Sao Paulo Autopsy Service. Brain parts are frozen and fixated. CSF, carotids, kidney, heart and blood are also collected and DNA is extracted. The neuropathological examinations are carried out based on accepted criteria, using immunohistochemistry. Functional status are assessed through a collateral source based on a clinical protocol. Protocols are approved by the local ethics committee and a written informed consent form is obtained. RESULTS: During the first 21 months, 1,602 samples were collected and were classified by Clinical Dementia Rating as CDR0: 65.7%; CDR0.5:12.6%, CDR1:8.2%, CDR2:5.4%, and CDR3:8.1%. On average, the cost for the processing each case stood at 400 US dollars. To date, 14 laboratories have been benefited by the BBBABSG. CONCLUSION: The high percentage of non- demented subjects and the ethnic diversity of this series may be significantly contributive toward aging brain processes and related neurodegenerative diseases understanding since BBBABSG outcomes may provide investigators the answers to some additional questions. 相似文献
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To elucidate the mechanism of sunlight-induced skin damage, guinea pigs were exposed to UV light (280-320 nm, UV B, 4 J/cm2) and a homogenate of the epidermis was examined by means of the thiobarbituric acid (TBA) test. Three hours after the exposure, TBA-malondialdehyde adducts had increased while glutathione reductase activity had decreased, indicating lipid peroxidation. To detect the initial species, spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was applied to a suspension of illuminated epidermal cells (0.5 J/cm2). An ESR signal obtained only with irradiation comprised a 1:2:2:1 quartet [a(N)= a(beta H) = 1.49 mT] attributable to a spin adduct of hydroxyl radicals. These results suggest that sunlight exposure of skin may lead to hydroxyl radical generation and simultaneous lipid peroxidation. 相似文献
10.
凝结芽胞杆菌对大鼠降糖作用的实验研究 总被引:1,自引:1,他引:0
目的:考察凝结芽胞杆菌(简称TQ33)对糖尿病大鼠病理模型的降血糖作用及糖耐量的影响,方法:以四氧嘧啶制备糖尿病大鼠病理模型后,灌服TQ33口服液,以氧化酶法测定大鼠血清中血糖含量。结果:TQ33对正常大鼠的空腹血糖基本无影响,对糖耐量的Cmax有明显的降低作用,并促进血糖水平迅速恢复;TQ33可降低实验性糖尿病大鼠的血糖水平,对糖耐量的Cmax有明显的降低作用,使糖耐量减低现象好转,结论:TQ33对由于四氧嘧\啶造成的糖尿病大鼠模型有一定的治疗作用。 相似文献
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Patterson SS Smith MW Casper ET Huffman D Stark L Fries D Paul JH 《Journal of applied microbiology》2006,101(4):956-963
AIMS: To use molecular beacon based nucleic acid sequence-based amplification (NASBA) to develop a rapid, sensitive, specific detection method for norovirus (NV) genogroupII (GII). METHODS AND RESULTS: A method to detect NV GII from environmental samples using real-time NASBA was developed. This method was routinely sensitive to 100 copies of target RNA and intermittent amplification occurred with as few as 10 copies. Quantitative estimates of viral load were possible over at least four orders of magnitude. CONCLUSIONS: The NASBA method described here is a reliable and sensitive assay for the detection of NV. This method has the potential to be linked to a handheld NASBA device that would make this real-time assay a portable and inexpensive alternative to bench-top, lab-based assays. SIGNIFICANCE AND IMPACT OF THE STUDY: The development of the real-time NASBA assay described here has resulted in a simple, rapid (<1 h), convenient testing format for NV. To our knowledge, this is the first example of a molecular beacon based NASBA assay for NV. 相似文献
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目的:探讨血清降钙素原(PCT)作为早期诊断新生儿败血症指标的临床价值。方法:应用免疫色谱法对101例新生儿进行PCT水平测定,并与C反应蛋白(CRP)作比较。将患儿按出院诊断分为败血症组、一般感染组、非感染组进行分析。结果:败血症组患儿血清PCT和CRP明显高于一般感染组和非感染组,差异有统计学意义(P<0.05);一般感染组与非感染组血清PCT、CRP比较差异有统计学意义(P<0.05)。以0.5ng/mL为临界值,PCT诊断新生儿败血症的敏感度为92.11%,特异度为78.79%;以8.0mg/L为临界值,诊断败血症的敏感度为65.79%,特异度为69.70%。与CRP相比,PCT诊断败血症的敏感性、特异性更高。经有效抗生素治疗后,血清PCT下降幅度明显大于血清CRP下降幅度。结论:新生儿血清中PCT水平的检测对败血症的早期诊断及病情程度判断、治疗效果的评价具有重要价值。 相似文献
15.
Role of puncture and aspiration in expectant management of simple ovarian cysts: a randomised study.
G. Zanetta A. Lissoni V. Torri C. Dalla Valle D. Trio G. Rangoni C. Mangioni 《BMJ (Clinical research ed.)》1996,313(7065):1110-1113
OBJECTIVES: To assess the potential of expectant management for simple ovarian cysts diagnosed by transabdominal or transvaginal ultrasonography. To compare the results of needle aspiration with those achieved with simple observation. DESIGN: Randomised trial. SETTING: Hospital department of obstetrics and gynaecology. SUBJECTS: 278 women with simple cysts randomly allocated to simple observation (143) or ultrasound guided fine needle aspiration (135) between 1990 and 1994. MAIN OUTCOME MEASURES: Resolution of cyst or development of malignancy. RESULTS: After six months 269 were available for follow up. The rate of resolution was 46% (59/128) with aspiration and 44.6% (63/141) with observation. Only the diameter of the cyst (P < 0.0001) was a significant independent prognostic factor for resolution in a multivariate analysis. Age and treatment had no significant effect. One woman was subsequently found to have borderline malignant changes on histopathological examination. Her cyst was detected by transabdominal ultrasonography. CONCLUSIONS: Expectant management for up to six months does not cause risks for the patients and allows spontaneous resolution in over a third of cases, avoiding the costs and risks of unnecessary surgery. Aspiration does not provide better results than simple observation. 相似文献
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目的:从产品开发角度分析全球合成生物学发展现状和趋势。方法:在伍德罗·威尔逊国际学者中心的合成生物学产品和应用清单(synthetic biology products and applications inventory)的数据基础上,对全球合成生物学产品的开发状态、市场应用和发展前景等进行补充检索和分析。结果:至2015年,全球至少已有81家企业(或研究机构)的116种合成生物学产品得到了市场应用开发,主要开发者为美国企业(或研究机构),产品主要集中于化学和医药领域。结论:合成生物学实现了从生物学分析向生物学合成的范式转移,其产品开发将给一系列的行业带来深刻的变革。 相似文献
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云南下关地区大绒鼠(Eothenomys miletus)体温调节和产热特征日节律的初步研究 总被引:1,自引:0,他引:1
为探讨横断山区小型哺乳动物体温调节和产热特征的日节律,对横断山区固有种大绒鼠(Eothenomys mile-tus)在24h中4个时间段(05:00—07:00、11:00—13:00、17:00—19:00、23:00—01:00)的体温、基础代谢率、非颤抖性产热进行了测定。结果显示大绒鼠的体温、基础代谢率、非颤抖性产热在24h内具有节律性波动,且变化趋势基本同步;各生理参数的最高值和最低值都分别出现在05:00—07:00和11:00—13:00时间段。结果表明,横断山区大绒鼠的基础代谢率、非颤抖性产热在其体温调节的日节律中起到了重要作用,同时,大绒鼠其夜间体温调节、产热特征显著高于白天,以适应横断山日温差大、食物资源丰富的特征。 相似文献
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目的:1.建立犬食管气管瘘动物模型;2.观察食管壁双瓣修补气管缺损术局部组织病理学改变、愈合情况及该术式的治疗效果。方法:犬16只,随机分为2组,实验组(12只)建立犬食管气管瘘动物模型,行食管壁双瓣修补气管缺损术,对照组(4只)正常犬作为空白对照,术后支气管镜检查,术后1,2,8周处死动物,观察实验动物一般情况、修补局部的大体改变和组织病理学改变,测定气管狭窄指数。结果:成功建立了犬食管气管瘘动物模型;食管双瓣修补术后,实验组动物呛咳症状消失,均存活至预定时间,修补瓣和气管之间愈合良好,修补瓣血供良好,未出现气管狭窄情况,气管通畅度良好。结论:通过手术方式建立食管气管瘘模型方法可靠;食管双瓣修补术治疗TEF效果良好,值得进一步研究及推广。 相似文献
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开发缺氧调控载体用于肾性贫血的基因治疗 总被引:1,自引:1,他引:0
目的:开发具有缺氧调控活性的基因治疗载体,其表达可由缺氧选择性诱导,用于肾性贫血的逆转和治疗。方法:合成源于各种缺氧应答基因的缺氧应答元件(HRE)寡核苷酸序列,与CMV启动子连接组合,测定荧光素酶的相对活性以确定缺氧转录活性。结果:在各种缺氧调控载体中,由鼠PGK(mPGK)基因的HRE序列和CMV启动子组合成的缺氧应答启动子显示出14.6倍的高缺氧应答性,而且缺氧诱导的表达水平与完整的CMVI.E启动子在常氧环境下的转录水平相近。结论:3HRE/mPGK/CMV缺氧调控载体对于肾性贫血等一系列疾病实现目的基因的精确调控表达可能非常有用。 相似文献
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Dynamic analyses of the expression of the HISTONE::YFP fusion protein in arabidopsis show that syncytial endosperm is divided in mitotic domains
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Boisnard-Lorig C Colon-Carmona A Bauch M Hodge S Doerner P Bancharel E Dumas C Haseloff J Berger F 《The Plant cell》2001,13(3):495-510
During early seed development, nuclear divisions in the endosperm are not followed by cell division, leading to the development of a syncytium. The simple organization of the Arabidopsis endosperm provides a model in which to study the regulation of the cell cycle in relation to development. To monitor nuclear divisions, we constructed a HISTONE 2B::YELLOW FLUORESCENT PROTEIN gene fusion (H2B::YFP). To validate its use as a vital marker for chromatin in plants, H2B::YFP was expressed constitutively in Arabidopsis. This enabled the observation of mitoses in living root meristems. H2B::YFP was expressed specifically in Arabidopsis syncytial endosperm by using GAL4 transactivation. Monitoring mitotic activity in living syncytial endosperm showed that the syncytium was organized into three domains in which nuclei divide simultaneously with a specific time course. Each mitotic domain has a distinct spatiotemporal pattern of mitotic CYCLIN B1;1 accumulation. The polar spatial organization of the three mitotic domains suggests interactions between developmental mechanisms and the regulation of the cell cycle. 相似文献