青岛地区结核分枝杆菌embB306基因突变特征与乙胺丁醇耐药的关系

目的：探讨青岛地区结核分枝杆菌 embB306突变特征与乙胺丁醇耐药的关系。方法应用聚合酶链反应（PCR）-DNA 测序法对来自青岛地区36株乙胺丁醇耐药和48株乙胺丁醇敏感的结核分枝杆菌的 embB 基因片段进行分析。结果48株乙胺丁醇敏感菌株中均未发生 embB306突变,而36株乙胺丁醇耐药菌株中有20株发生了embB306突变,突变率为55．6％;embB306突变在乙胺丁醇敏感菌株和乙胺丁醇耐药菌株中的分布差异具有统计学意义（χ2＝35．000,P ＜0．01）。结论在青岛地区,embB306的突变是青岛地区结核分枝杆菌对乙胺丁醇耐药的主要机制。     

结核分枝杆菌乙胺丁醇耐药的分子机制及其快速鉴定

目的：了解结核分枝杆菌乙胺丁醇(EMB)耐药的临床分离株embB基因突变的情况，并探索快速检测结核分枝杆菌EMB耐药性的实验方法。方法：应用聚合酶链反应-单链构象多态性(PCR-SSCP)技术和PCR扩增产物测序方法。分析结核分枝杆菌EMB耐药和敏感各30株的embB基因。结果：以结核分枝杆菌H37RV标准株为对照。发现30株EMB耐药株中有11株(36．7％)embB基因扩增产物SSCP泳动异常，部分耐药菌株测序分析证实为306位密码子突变；而30株敏感株的embB基因扩增产物SSCP泳动均无异常。结论：embB基因突变是结核分枝杆菌EMB耐药的重要机制之一；PCR-SSCP技术可能成为一种检测结核分枝杆菌EMB耐药性的准确和快速的实验方法。     

结核杆菌耐药性调查与基因突变分析

目的了解结核分支杆菌耐药性与基因突变情况,分析耐药表型与基因突变的相关性。方法从临床标本中分离培养、鉴定结核分支杆菌;应用药敏试验、单链探针反向杂交试验技术(LiPA)和基因测序分析结核分支杆菌耐药性与基因突变情况。结果50株结核分支杆菌中,12株耐异烟肼(INH),7株耐利福平(RFP),15株耐链霉素(SM),2株耐乙胺丁醇(EMB)。LiPA检测耐RFP菌株,4株rpoB基因531位TCG→TTG突变;耐INH菌株中5株KatG基因315位AGC→ACC突变;耐SM菌株中6株、SM敏感株1株rpsl基因43位AAG→AGG突变,1株耐SM菌株rpsl基因88位AAG→AGG突变;rrs基因未检测到突变;1株耐EMB菌株与1株EMB敏感株的embB基因306位发生ATG→GTG突变。结论本市结核分支杆菌的耐药性增加的趋势显著,加强监测与综合干预非常必要。     

耐多药结核分枝杆菌中embB基因突变与乙胺丁醇耐药的相关性研究

目的 研究耐多药结核分枝菌中embB基因突变与乙胺丁醇耐药的相关性. 方法 比例法检测84株耐多药结核分枝杆菌的乙胺丁醇(EMB)耐药性,基因测序检测embB基因的突变,2检验分析二者之间的相关性. 结果 84株耐多药结核分枝杆菌中有43株(51.2%)对EMB耐药,41株(48.8%)对EMB敏感,57株耐多药菌株(67.9%)的embB基因发生突变.在43株EMB耐药菌株中,embB基因突变的菌株为40株(93.0%),而41株EMB敏感菌株中,embB基因突变的菌株为17株(41.5%),embB基因在耐药菌株中的突变频率远高于敏感菌株(2=25.58,P=0.00).embB306是最常见的突变位点,其在耐药菌株的突变率也高于敏感菌株(2=12.37,P=0.00),embB基因和embB306位点检测EMB耐药的敏感度、特异度和准确性分别为93.0%和65.1%,58.5%和73.2%,76.2%和69.0%. 结论 EMB耐药的产生与embB基因和embB306突变有关,二者用于检测EMB耐药有一定的参考意义.     

PCR-DNA测序技术检测结核分支杆菌耐多药基因突变的研究

目的应用PCR—DNA测序技术快速检测同时耐利福平和异烟肼结核分支杆菌分离株rpoB、KatG基因突变，评价其在检测结核分支杆菌耐多药性方面的价值。方法47株耐利福平和异烟肼结核分支杆菌临床分离株及30株结核分支杆菌敏感分离株用PCR—DNA测序技术分别检测rpoB、KatG基因突变。结果47株耐多药结核分支杆菌分离株中，检出43株rpoB基因突变，突变检出率为91．5％（43／47）；31株KatG基因突变，突变检出率为66．0％（31／47）；rpoB和KatG基因同时突变者31株，突变检出率为66．0％（31／47）。30株结核分支杆菌敏感株检出1株KatG基因突变。结论PCR—DNA测序技术方法敏感、准确、特异，可快速检测结核分支杆菌rpoB、KatG耐药基因突变，有利于耐多药结核分支杆菌耐药性的快速检测。     

结核分枝杆菌embB基因突变检测的研究进展

乙胺丁醇（EMB）是具有广谱抗分枝杆菌活性的一线抗结核合成药物。被广泛应用于结核分枝杆菌和鸟分枝杆菌、堪萨斯分枝杆菌等多种非结核分枝杆菌感染的治疗。近年来。结核病疫情呈上升趋势．其耐药问题也日趋严峻，乙胺丁醇（EMB）作为主要的抗结核药物，在原发和复发结核病患者中的耐药率有上升趋势．据报道在一些国家获得性EMB耐药率已达13．7％。有研究表明MTB耐乙胺丁醇与阿拉伯糖基转移酶的编码基因EMB操纵子突变或EMB蛋白过度表达有关。该操纵子由embA、embB、embC3个基因组成．其中embB基因（尤其是306位密码子）突变是EMB耐药的主要原因。现就EMB的药理作用、耐药机制、检测方法做一综述。     

结核分枝杆菌耐乙胺丁醇分离株embB基因突变的研究

目的 了解结核分枝杆菌耐乙胺丁醇（EMB）分离株embB基因突变情况,研究其应用价值。方法 通过聚合酶链反应－单链构象多态性（PCR－SSCP)、CPR－限制性片段长度多态性（RFLP）和PCR－直接测序技术分析102株结核分枝杆菌临床分离株embB基因。结果 以H37Rv标准株为对照,102株结核分枝杆菌临床分离株的162rDNA SSCP电泳图谱均与结核分枝杆菌标准株相同。41株药物敏感株的embB基因SSCP均泳动正常,RFLP和测序分析与对照株相同。61株耐EMB分离株可,23株（37．7％）embB基因SSCP泳动异常;8株RFLP分析异常;测序分析23株均为306位密码子突变,其EMB MICs均≥20μg/ml,其中8株为ATG→ATA或ATT突变,13株为ATG→GTG或CTG突变,后者EMB MICs均≥30μg/ml。结论 部分结核分枝杆菌耐EMB是由于其embB基因突变所致,PCR－SSCP技术可能成为测定部分结核分枝杆菌EMB耐药基因型,简便、快速的方法。     

应用聚合酶链反应-寡核苷酸探针快速检测结核菌耐药基因突变

目的应用聚合酶链反应(PCR)-寡核苷酸探针快速检测结核菌耐药基因突变，建立一种新的分子药敏试验方法。方法以传统药敏试验、PCR-单链构象多态性和PCR-直接测序方法为对照，对利福平、链霉素(SM)和乙胺丁醇耐药的结核菌基因rpoB、rpsL、ITS和embB的寡核苷酸探针，通过反向斑点杂交检测78株结核菌临床分离株PCR产物。结果18株结核菌药物敏感株的4种耐药基因均为野生型。60株结核菌耐药分离株中，59株为耐RFP株，rpoB基因突变率为93．2％，最常见的突变位点为531位和526位密码子，33株为耐SM株，rpsL基因突变率为75．8％，均为43位密码子AAD AGG突变，ITS基因突变率为9．1％，均为513位A→C突变，rpsL和ITS基因总突变率为84．8％；43株为耐EMB株，embB基因突变率为58．1％，均为306位密码子突变。结论应用PCR一寡核苷酸探针反向斑点杂交技术可简便、快速、准确地分析大多数结核菌耐药基因突变，检测其耐药性。     

用反向斑点杂交法检测结核杆菌对链霉素和乙胺丁醇的耐药性

目的建立结核分支杆菌对链霉素（SM）和乙胺丁醇（EMB）耐药基因突变的快速检测方法。方法根据结核分支杆菌标准株H37Rv序列,自行设计针对rpsL和embB基因常见耐药突变的系列寡核苷酸探针,制成膜芯片,并对64例结核分支杆菌临床株的基因突变情况进行检测。结果在34株SM耐药菌中,有25株被检出在rpsL基因分析部位发生突变,检出率为73．5％（25／34）,其中23株（67．6％）为第43位密码子AAG→AGG突变,2株（5．9％）为第88位密码子AAG→AGG突变;在32株EMB耐药菌中,有19株在embB基因分析部位发生突变,检出率为59．4％（19／32）,其中12株（37．5％）为ATG→GTG突变;6株（18．8％）为ATG→ATA突变;1株（3．1％）为ATG-＊CTG突变。膜芯片检出的突变与基因测序结果一致。结论用膜芯片检测结核分支杆菌对链霉素和乙胺丁醇的耐药性,具有较高的特异性和敏感性,可作为常规药敏方法的补充,用于指导开展早期、有效的临床化疗。     

embB基因突变与乙胺丁醇药敏表型及耐多药关系的研究

目的 研究结核分枝杆菌(Mycobacterium tuberculosis,MTB)embB306位点及其他突变位点与乙胺丁醇(ethambutol,EMB)的耐药表型及耐多药(multidrug resistant,MDR)的关系;分析embB基因突变与EMB药敏表型及MDR的关系. 方法 对临床分离的MTB采用BD MGIT 960 SIRE试剂比例法进行药敏试验,取48株EMB耐药、46株EMB敏感但耐其他药及7株四药均敏感MTB提取核酸并扩增embB基因全序列,对扩增产物进行测序分析embB基因序列,与H37Rv标准株序列比对,分析embB基因各突变位点、形式及频率. 结果 101株MTB发现embB基因序列上有17个不同位点突变形式.53株MTB在embB基因序列上发生突变,其中46株为EMB耐药,7株为EMB敏感;embB基因野生型的MTB有48株,其中2株为EMB耐药,46株为EMB敏感;embB突变型与embB野生型的MTB之间EMB耐药率有显著性差异(x2=68.95,P＜0.01).101株MTB中MDR有51株,其中有42株发生embB突变,9株为embB基因野生型,embB基因突变率在MDR和非MDR之间有显著性差异(x2=36.9,P＜0.01). 结论 embB306位点与EMB耐药及MDR中度相关,embB基因突变与EMB耐药及耐多药结核菌(multidrug resistant-Mycobacteriumtuberculosis,MDR-TB)高度相关,embB基因突变可作为MDR-TB的检测分子标记物,指导临床用药.     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.