应用HMM和加权距离判别法的真核基因识别程序研究

根据现代科学对基因的认识，应用了隐马尔科夫模型(HMM)的算法，以大量核酸序列为信息来源，通过计算机计算来寻找未知基因的大体位置；再通过基因的固有结构特征及密码子使用的偏向性，使用加权距离判别法来准确地定位基因，以图形及文本的形式输出，从而极大地方便了实验室的研究工作。考虑到基因的许多特征还不为人们所了解，而且不同物种之间基因结构又有一定的差异，所以还开发了程序自学习功能，不断地存储已知的基因，再据此改变一些已有固有数据，以便更好地适应和了解不同生物基因结构的特异性，更加准确地寻找未知基因的位置。     

中药导入气流弥散法治疗便秘的临床观察

便秘是临床常见病，常见症状有不能自主排便，排便间隔时间延长，大便干结、排出困难等。该疾病复发率高，口服药物治疗效果不佳，难于治愈。我院用朱传娣首创的CHD—1000A型气、液多功能自动全结肠给药器（曾于1996年获国家专利，专利号ZL96231968．6）实行中药导人气流弥散法治疗，将朱传娣研制的中药——芪黄肠康液用射流式肛管自肛门插管灌人全结肠治疗该病，取得了较满意的疗效。     

乳腺良恶性病变的磁共振T2*W首过灌注成像与血管生成相关性研究

Objective： To study the diagnostic value of T2^＊-weighted first-pass perfusion imaging in breast tumors. Methods： We analyzed the magnetic resonance imaging （MRI） information along with the pathological and immunohistochemistry results. Magnetic resonance imaging was performed in 28 patients with breast tumor. The time to signal intensity curves were generated according to the T2^＊-weighted first-pass perfusion imaging. The curve＇s maximal signal intensity drop rate and maximal signal intensity decrease time were analyzed and compared with the pathological diagnoses after surgery. Results： Malignant breast lesions showed higher maximal signal intensity drop rate （44.69% ± 17.07 vs. 17.22% ±7.49, P 〈 0.001） than benign lesions, but there was no significant difference of maximal signal decrease time between those two lesions （23.94 s ± 4.92 vs. 20.02 s ± 6.83, P 〉 0.05）. Conclusion： The T2^＊-weighted first-pass perfusion imaging has enough sensitivity and specificity in breast tumor diagnosis.     

美国科学家制造出扫描速度更快的CT

美国北卡罗来纳大学教堂丘分校的科学家们使用碳纳米管X线发展出了一种新的计算机断层成像（CT）技术。这种技术与以往的CT相比，扫描速度快很多，并且使用更低的峰值功率。他们的工作发表在最新一期的《Applied Physics Letters》上。     

ADC图和动态增强平面回波MR序列评价头颈部癌的颈部淋巴结转移

目的：评价ADC图和动态增强平面回波MR序列对诊断头颈部癌颈部淋巴结转移的临床应用价值。方法：对51名头颈部癌伴颈部淋巴结病变的患行扩散加权（DWI）和动态增强T2。灌注加权。DWI采用单次激发EPI序列，b值为500和1000s／mm^2，并重建出ADC图。多层面MR灌注成像采用单次激发平面回波T2WI，在首过团注Gadolinium-DTPA（0．2ml mol／kgBW）后每两秒采集一次，共采集2min以获得信号强度时间曲线。计算出淋巴结的ADC值和最大信号强度下降的百分比，并与组织病理学进行对照。     

外伤性高位截瘫41例影像检查诊断价值

目的：探讨X线、CT、MRI等检查手段在外伤性高位截瘫诊断中的价值。方法：4l例外伤性高位截瘫的临床及影像资料作回顾性分析，脊椎损伤采用Denis系统分型；脊髓损伤采用ASIA损伤分级评价其神经功能；以MRI颈髓损伤及临床表现为参照探讨影像检查方法间的相互关系。结果：颈椎损伤：过屈型7列、过伸型12例、轴向负荷型22例；脊髓的压迫程度：Ⅰ型5例、Ⅱ型27例、Ⅲ型9例；椎体骨折34处，附件骨折23处，脱位11处。结论：X线、CT、MRI等检查手段在高位截瘫诊断中相互补充，是颈部分外伤患者不可缺少的检查手段，应当作为常规检查。     

磁共振成像对子宫腺肌症诊断及鉴别诊断价值研究

子宫腺肌症(adenomyosis)是异位的子宫内膜侵入肌层而产生的,发病率为25%~40%,近年来有明显上升趋势[1],是妇科的常见病之一。由于子宫腺肌症的临床症状、体征、实验室理化指标均没有特异性,临床上与子宫肌瘤很难鉴别,且有21%~40%的病例与子宫肌瘤并发,给临床诊断带来一定困难[     

屈颈MRI对青年性上肢远端肌萎缩症的诊断价值

目的评价屈颈MRI对青年性上肢远端肌萎缩症的诊断价值。方法男性患者5例，平均年龄21岁，临床表现为一侧或两侧上肢远端肌萎缩。对照组为健康志愿者，21岁男性8例。2组均行常规及屈颈颈椎MR平扫，矢状、轴面SET1WI、T2WI、液体衰减反转恢复（FLAIR）序列扫描。结果常规颈椎扫描：5例患者下段颈髓变细；屈颈位MR扫描：下颈段颈6以下脊髓前屈、变扁平，矢状径4～6mm，硬膜囊后壁前移，硬膜后间隙明显增宽，可见多发条状、迂曲流空信号影及软组织信号。对照组：常规扫描，下颈段脊髓（颈6～胸2）可见颈膨大，屈颈位脊髓略变细（6～7mm），硬膜囊后壁无前移，硬膜后间隙未见扩张血管影。结论屈颈MRI有助于显示下颈段脊髓及硬膜囊改变，结合临床资料可准确诊断青年性上肢远端肌萎缩症。     

^1H-magnetic resonance spectroscopy screening for animals with acute cerebral infraction suitable forthrombolytic therapy

BACKGROUND: As a non-invasive technique which can provide comprehensive biological information, 1H-magnetic resonance spectroscopy (1H-MRS) may provide valuable reference data for irreversible recovery or reversible changes in ischemic tissue after stroke. OBJECTIVE: To monitor and evaluate the effect of the urokinase thrombolytic therapy after experimental acute cerebral ischemia by 1H-MRS technology and investigate its adaptability. DESIGN: Randomly controlled animal study. SETTINGS: Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science. MATERIALS: Eleven healthy adult Sprague-Dawley (SD) rats, weighing 260–300 g and of both genders, were supplied by Experimental Animal Center of Tongji Medical Collage, Huazhong University of Science and Technology [SCXK (e) 2004-007]. 4.7T superconducting nuclear magnetic resonance meter was provided by Brucker Company. METHODS: The experiment was carried out in Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science from August 2003 to December 2005. ① The rats were randomly divided into 30-minute self-thrombo-embolism group (n =6) and 60-minute self-thrombo-embolism group (n =5). Six rats in 30-minute self-thrombo-embolism group were occluded with clot embolus for 30 minutes and 5 rats in 60-minute self-thrombo-embolism group were occluded for 60 minutes. 10 000 U/kg urokinase was dissolved in 2 mL saline and the operation lasted for 5 minutes. ② 1H-MRS was performed before thrombolysis and at 3 hours and 24 hours after successful embolization. The metabolic changes of N-acetyl-L-aspartic acid (NAA)/phosphocreatine (PCr) + creatine (Cr), choline phosphate (Cho)/PCr+Cr and lactic acid (Lac)/PCr+Cr in the region of interests were analyzed. ③ The T2W image was conducted 24 hours after the thrombolytic therapy with TR=500 ms and TE=25 ms. ④ The subjects were sacrificed immediately after 1H-MRS and the brain tissues were cut into pieces and stained with HE method; in addition, pathological changes were observed under optic microscope. MAIN OUTCOME MEASURES: ① Metabolic changes of NAA/PCr+Cr, Cho/PCr+Cr and Lac/PCr+Cr in the region of interests; ② T2W image at 24 hours after the thrombolysis; ③ pathological observation of brain tissue. RESULTS: Eleven rats were all involved in the final analysis. ① Metabolic changes in the region of interests : In 30-minute self-thrombo-embolism group, the Lac peak emerged immediately after the embolism, but the ischemic zone decreased 3 hours after the thrombolytic therapy (0.252±0.01, 0.603±0.01, P < 0.01). Lac/(PCr+Cr) ratio was 0.290±0.01 at 24 hours after thrombolysis, which was higher than that at 3 hours after thrombolysis (P < 0.01). The NAA/ (PCr+Cr) ratio decreased significantly at 3 hours after the thrombolysis as compared with that before thrombolysis (0.922±0.16, 1.196±0.01, P < 0.05). In 60-minute self-thrombo-embolism group, the Lac/(PCr+Cr) ratio was higher at 3 hours after thrombolysis than that before thrombolysis (0.846±0.12, 0.601±0.11, P < 0.05) and the NAA/(PCr+Cr) decreased at 3 hours after the embolism. Fluctuation of NAA/ (PCr+Cr) ranged from 0.68 to 0.75 before thrombolysis and from 0.71 to 0.75 at 3 hours after thrombolysis. ② T2W image: T2W image showed that 2 subjects in 30-minute self-thrombo-embolism group whose Lac/NAA was higher than 0.7 suffered from intracranial hemorrhage. This meant that the subjects with Lac/NAA > 0.7 were more likely to suffer from intracranial hemorrhage. ③ Histological and morphological examinations: Optic microscope demonstrated that interspace surrounding nerve cells was widened at ischemic center; neurons were swelling; nucleus was stained lightly; pyknosis and mesenchymal edema were mainly observed in lateral cortex of brow and vertex and in lateral part of corpus striatum. CONCLUSION: ①Compound parameters in ischemic area before thrombolysis should be regarded as an important predicting marker for thrombolytic therapy, effect evaluation and termination. ② 1H-MRS combining with other imaging technique is a detecting way for screening cases who are suitable for thrombolytic therapy.