脑星形细胞瘤影像表现与病理对照研究

目的:分析不同级别脑星形细胞瘤的影像表现,探讨影像表现与脑星形细胞瘤病理分级的相关性。方法:收集经CT及MRI诊断和手术病理证实的脑星形细胞瘤85例,按病理诊断标准分为四级,Ⅰ级13例,Ⅱ级21例,Ⅲ级28例,Ⅳ级23例。对肿瘤大小、密度、水肿、钙化、强化程度、强化类型等CT表现与病理分级进行对照研究,采用卡方检验;对MRI表现的8个特征(信号不均匀性、囊变坏死、出血、越过中线、水肿、边界、强化程度及强化不均匀性)与星形细胞瘤病理分级进行统计分析,采用卡方检验。结果:(1)肿瘤的大小、钙化等情况在各组间差异无显著性(P>0.05);而肿瘤密度、瘤周水肿、强化程度及类型在各组间差异存在显著性(P<0.05)或高度显著性(P<0.01);(2)除越过中线外,其余7个MRI征象均对星形细胞瘤分级有较大的帮助,尤其是囊变坏死、边界、水肿、肿瘤强化程度及强化不均匀性在各级星形细胞瘤之间差异均有极显著性意义(P<0.01)。结论:星形细胞瘤影像表现与其病理分级有一定的相关性,CT及MRI对星形细胞瘤的分级诊断有较大的价值。     

脑星形细胞瘤的瘤周水肿与MMP-9表达和血管形成相关性的研究

目的:探讨脑星形细胞瘤瘤周水肿与基质金属蛋白酶-9 (MMP-9)表达和血管形成的关系。方法:采用免疫组织化学(SP)法,用抗MMP-9抗体及CD34单抗对40例星形细胞瘤组织标本进行标记分析,并测定MRI图像上肿瘤瘤周水肿范围。结果:脑星形细胞瘤恶性程度越高,MMP-9的表达和微血管密度(MVD)值越高(P<0.01);随着MMP-9表达的增高和新生血管的增多,瘤周水肿范围越大 (P<0.01)。结论:星形细胞瘤的瘤周水肿与MMP-9、MVD的表达密切相关。     

幕上星形细胞瘤MR征象与肿瘤血管形成的对照研究

目的　探讨星形细胞瘤MR征象与肿瘤血管形成的相关性。方法　研究 68例幕上星形细胞瘤 ,术前进行MRI检查及术后病理证实的幕上星形细胞瘤石蜡标本进行免疫组化染色 ,测定微血管密度 (MVD) ,并测量MR图像上肿瘤大小、坏死、出血、信号均匀度、瘤周水肿范围、增强扫描强化程度及形态。结果　MR图像中 ,星形细胞瘤坏死、出血、信号不均匀 ,水肿及强化程度与MVD密切相关 ,且随肿瘤恶性度增加 ,MVD值增高 (P <0 .0 1)。结论　星形细胞瘤MR征象与肿瘤血管形成密切相关 ,MRI能间接反映星形细胞瘤的分子生物学行为。     

星形细胞瘤VEGF表达与瘤周水肿、瘤脑界面问关系的CT研究

目的研究星形细胞瘤瘤周水肿、瘤脑界面与血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)间的关系,探讨其CT征象的分子生物学意义.方法运用SP免疫组化法,检测52例术后经病理证实的星形细胞瘤VEGF.分析瘤周水肿、瘤脑界面与VEGF间的关系.结果肿瘤边缘、瘤周水肿、占位效应与VEGF表达密切相关.随水肿、占位程度的增加,VEGF阳性率亦显著增高(P＜0.01).边缘模糊组的VEGF阳性率分别69.2±19.0,与边缘清楚组间的VEGF阳性率存在统计学差异(P＜0.05).结论星形细胞瘤的VEGF异常表达,对瘤周水肿及瘤脑界面等CT征象有明显影响.     

周围型肺癌16层螺旋CT征象与肿瘤微血管密度相关性研究

目的:探讨周围型肺癌16层螺旋CT征象与肿瘤内微血管密度的关系。为将16层螺旋CT作为一种评价肿瘤血管生成的无刨性检查手段应用于临床提供理论依据。方法:收集48例经手术及病理证实的周围型肺癌(鳞癌27例,腺癌21例)。术前行16层螺旋CT扫描,用S-P免疫组化法检测病理标本的微血管密度。结果:周围型肺癌中腺癌微血管密度(microvesseldensity,MVD)明显高于鳞癌,分别为61.57±10.29和52.46±11.32(P<0.05)。肺癌MVD值与16层螺旋CT影像上肿瘤直径、分叶征、血管集束征、胸膜凹陷征及纵隔淋巴结转移均有密切关系(P<0.05)。结论:周围型肺癌16层螺旋CT征象与其微血管密度值有密切关系。可用于预测肺癌的组织学类型和评价其恶性程度。     

脑星形胶质细胞瘤CT表现及与手术、病理对照研究

目的:通过分析脑星形胶质细胞瘤的CT表现与手术、病理分级间对应关系,探讨CT表现的病理基础。方法:报道82例脑星形胶质细胞瘤的CT、手术、病理分级对照资料,并将病理分级分为3组:良性组(Ⅰ~Ⅱ级)16例,交界组(Ⅱ级)31例,恶性组(Ⅱ~Ⅳ级)35例,对3组间肿瘤大小、密度、水肿、强化程度、钙化、出血、囊变坏死等CT表现进行对照研究。结果:肿瘤的大小、钙化、血供、边界情况3组间无显著性差异;而肿瘤密度、瘤周水肿、强化程度及类型、瘤内囊变坏死、肿瘤硬度等3组间或两组间(良性组与交界组合并为一组)则存在显著性或高度显著性差异,其中恶性组趋向于呈混杂密度、中?蛐重度混杂强化、中?蛐重度瘤周水肿、瘤内多见坏死囊变、肿瘤硬度偏软等特征,良性组则相反。结论:不同病理分级的脑星形胶质细胞瘤的CT表现各有其特点,可作为肿瘤分级提示性诊断的依据。     

CT评价肝细胞癌血管生成和凋亡抑制蛋白表达的价值

目的:探讨增强CT评价肝细胞癌(HCC)组织中血管生成以及凋亡抑制蛋白bcl-2和bcl-xl表达的价值。材料与方法:对38例共40个经病理证实且行动静脉双期CT增强扫描的HCC病灶进行分析,用免疫组化SP法检测癌组织中微血管密度(MVD)以及bcl-2和bcl-xl的表达情况,将CT增强表现特征与免疫组化的结果进行对照分析。结果:所有病灶的平均MVD为39.3±8.40,bcl-2和bcl-xl的阳性表达率分别为27.5%(11?/40)和50%(20/40)。bcl-2和bcl-xl之间具有一定的相关性(P<0.01),在bcl-xl表达的阴性组和阳性组,MVD分别是34.70±8.13和41.34±6.95,存在明显差异(P<0.05)。CT显示的病灶大小与bcl-xl的表达具有一定的关系(P<0.05);另外CT显示的病灶边缘欠清组、瘤内出现液化坏死组以及侵袭转移组的MVD分别大于病灶边缘清晰组、瘤内无液化坏死组及无侵袭转移组(P<0.05)。结论:FⅧRA、bcl-2和 bcl-xl等蛋白在HCC组织中呈现不同程度的表达,CT在一定程度上评价HCC的血管生成价值要大于评价凋亡抑制蛋白的表达。     

微血管密度在骨巨细胞瘤中的表达及意义

目的探讨不同组织学分级、放射学分级的骨巨细胞瘤中CD34的表达及与肿瘤复发的相关性,为骨巨细胞瘤生物学行为和预后判断提供依据。方法本实验运用EnV ision法检测CD34在37例骨巨细胞瘤中的表达,分析其与临床病理特征、肿瘤复发的关系。结果骨巨细胞瘤中微血管密度(MVD)平均值为169±33,组织学分级Ⅲ级(202±14)者显著高于Ⅰ级(159±28)者(P<0.01),与Ⅱ级比较差异无统计学意义(P>0.05)。复发组(194±22)明显高于未复发组(155±30),二者比较差异有统计学意义(P<0.01)。结论MVD值与肿瘤复发有关,可作为预后判断的指标。     

VEGF与星形细胞瘤血管生成和瘤周脑水肿的相关性研究

目的探讨星形细胞瘤的血管内皮细胞生长因子(VEGF)表达与血管生成和瘤周脑水肿(PTBE)及病理分级的关系.方法术前进行MRI检查且经手术病理证实的34例星形细胞瘤患者.在MRI计算星形细胞瘤的瘤体体积和瘤周脑水肿体积,从瘤周脑水肿与肿瘤本身的体积之比获得水肿指数(EI),估价脑水肿的程度.采用免疫组化方法(SP法)检测 34例星形细胞瘤VEGF表达;Ⅷ因子相关抗原单克隆抗体免疫组织化学(SP法)染色显示微血管,测量微血管密度(MVD)表示肿瘤血管生成.结果 VEGF表达与脑星形细胞瘤的血管生成、瘤周脑水肿均呈显著正相关(r=0.77,P<0.001;r=0.336,P=0.05);高级别星形细胞瘤VEGF、MVD、EI分别显著高于低级别星形细胞瘤(t=7.08,3.37,2.74;P=0.01,0.011,0.025).结论 VEGF可能通过参与星形细胞瘤血管生成和脑水肿发生,对胶质瘤的恶性演进起促进作用;MRI瘤周脑水肿征象能间接反映星形细胞瘤的肿瘤血管形成和预测星形细胞瘤的恶性程度.     

高、低级别脑星形细胞瘤瘤周区CTP研究

目的：探讨高、低级别星形细胞瘤瘤周区CT灌注成像（CTP）参数的差异及其病理基础。方法：对30例手术与病理证实的脑星形细胞瘤（低级别星形细胞瘤10例、高级别星形细胞瘤20例）行术前CT平扫、增强及CTP检查,测量强化区近侧1cm处或低强化区距边缘1cm处的脑血流量（CBF）、脑血容量（CBV）、平均通过时间（MTT）及脑血管表面通透性（PS）值。比较高、低级别脑星形细胞瘤瘤周区CTP参数差异。对照影像学,采用肿瘤切除前活检的方法取得标本,观察瘤周区病理表现。结果：高级别星形细胞瘤瘤周区CBF、CBV、MTT及PS值高于低级别星形细胞瘤瘤周区。CBF、CBV、MTT及PS值,高级别星形细胞瘤瘤周区分别为（50.05±14.05）ml?蛐（min·100g）、（3.50±1.79）ml?蛐100g、（5.84±2.95）s及（1.23±1.75）ml?蛐（min·100g）,低级别星形细胞瘤瘤周区分别为（25.20±8.67）ml?蛐（min·100g）、（1.61±0.68）ml?蛐100g、（4.83±1.63）s及（0.33±0.27）ml?蛐（min·100g）,二组间CBF、CBV差异有统计学意义（P<0.05）。组织学上,高级别与低级别星形细胞瘤瘤周区均可见散在肿瘤细胞,前者肿瘤细胞密度较大、血管较多。结论：高级别与低级别脑星形细胞瘤瘤周区CBF、CBV有明显差别,其病理基础不同。     

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.