Pulsed ultrasound Doppler velocimetry in the assessment of microvascular hemodynamics

Pulsed ultrasonic Doppler velocimetry (20 MHz) (PUDVM) has evolved considerably in the last 10 years. Engineering development has resulted in a computer-controlled vessel-scanning instrument whose backscattered frequency shift spectra are analyzed using fast Fourier transforms (FFT). Benchtop and theoretic studies indicate accurate (error less than 5%) velocity and volumetric flow rate measurements in vessels with a lumen diameter as small as 1.2 mm. Clinical application of the PUDVM has provided transcutaneous measurements of blood flow variables in normal human digital arteries. Experimental application to arteries 1.0-1.5 mm has provided information on the hemodynamic effects of topical vasodilators, standard microarteriorrhaphy, variations in microvascular technique, interpositional grafts, and early wound repair. With improving computer capabilities and technical modifications, the PUDVM will be an increasingly important tool in clinical and experimental microsurgery.     

Detection of abnormal lesions recorded by capsule endoscopy: A prospective study comparing endoscopist''s and nurse''s accuracy

BACKGROUND AND STUDY AIM: Capsule endoscopy is a non-invasive technique for small bowel examination but its evaluation is time consuming. The aim of this study was to assess whether, following adequate training, an endoscopy nurse is capable of picking up all significant images without reducing the diagnostic accuracy of the procedure. PATIENTS AND METHODS: Between April 2003 and December 2004, a total of 41 consecutive capsule endoscopy studies were blindly reviewed by both an endoscopy nurse and an endoscopist. The two operators had to select all significant images independently and to complete a structured questionnaire. Thirty-nine capsule endoscopy examinations (two studies discharged for premature battery failure) were evaluated. The agreement between the two operators was calculated by kappa statistics (coefficient of agreement). RESULTS: Agreement was excellent for all kind of selected lesions (mean kappa>0.85); the agreement was complete (kappa=1) for site identification, active bleeding, stenosis and negative studies. The greater disagreement (kappa=0.77) was found in cases of subtle mucosal abnormalities (i.e. reduction of villi), which were over-estimated by the nurse. CONCLUSIONS: The preview recordings made by the nurse may increase the cost/effectiveness of the study, by considerably reducing the time needed for the endoscopist to make the final report (about 5-10 min), without compromising final diagnosis.     

Intra-observer and inter-observer agreement of the manual examination of the lumbar spine in chronic low-back pain

Examination is a cornerstone in the manual procedures leading to mobilisation/manipulation of the low back. The observer variation of the more specific segmental tests remains to be investigated. Two skilled specialists in manual medicine examined the segmental changes in the lumbar spine. The patients were unknown to the examiners and no information of the case history was given. All test results were recorded by an observer present in the room who ensured that no conversation was allowed during the examination. The primary outcome measures were the kappa values for each test. The matching was defined as acceptable (acc) within two neighbouring levels and perfect (per) on the same level. Intra-observer variation (tested in 33 patients and 10 subjects without low-back pain): The agreement between first and second segmental diagnosis examination was 70% (per) and 82% (per + acc). Kappa values were: segmental diagnosis 0.60 (per) and 0.70 (per + acc), multifidus test 0.51 (per) and 0.60 (per + acc), sideflexion 0.57 (per) and 0.69 (per + acc), and ventral flexion 0.31 (per) and 0.45 (per + acc). Inter-observer variation (tested in 60 patients): The agreement for segmental diagnosis between the examiner A and B was 42% (per) and 75% (per + acc). Kappa values were: segmental diagnosis 0.21 (per) and 0.57 (acc), multifidus test 0.12 (per) and 0.48 (acc), sideflexion 0.22 (per) and 0.45 (acc), and ventralflexion 0.22 (per) and 0.44 (acc). By manual tests, skilled examiners seem to be able to diagnose segmental dysfunctions in the low back. The clinical implication of these dysfunctions remains to be clarified.     

Autoradiographic localization of kappa opiate receptors in CNS taste and feeding areas

Recent evidence suggests that kappa opiate receptors may play a key role in the regulation of appetite. Such evidence implies that kappa receptors might be localized within specific brain areas known to regulate ingestive behaviors. On the basis of this implication we employed an in vitro film autoradiographic technique using 3H-ethylketocyclazozine as ligand to identify putative kappa receptors within CNS "taste" nuclei and surrounding areas. Coronal cryostat sections of rat brain were incubated with ligand in the presence of D-Ala2, D-Leu5-enkephalin (DADLE) and morphine, apposed to LKB Ultrofilm for 60 days, processed and kappa receptor densities evaluated with the aid of a hand held photometer and video image analyzer. Highest kappa receptor densities were found within various gustatory and feeding sites including the rostral pole of the nucleus of the solitary tract, parabrachial nuclei, ventral posterior and medial portions of the thalamus, medial hypothalamus, medial nuclei of the amygdala and bed nucleus of the stria terminalis. Various other midline and medial limbic areas also showed significant kappa densities.     

Antisense mapping KOR-1: evidence for multiple kappa analgesic mechanisms

In binding assays, both dynorphin B and alpha-neoendorphin are relatively selective for the kappa1b site, unlike U50,488H which has high affinity for both kappa1a and kappa1b sites. In vivo, U50,488H, dynorphin B and alpha-neoendorphin analgesia are reversed by the kappa1-selective antagonist, nor-binaltorphimine (norBNI). Antisense mapping the three exons of KOR-1 revealed that probes targeting all three exons blocked U50,488H analgesia, as expected. However, the selectivity profile of dynorphin B and alpha-neoendorphin analgesia towards the various antisense oligodeoxynucleotides differed markedly from U50,488H, implying a different receptor mechanism of action.     

神经元烟碱乙酰胆碱受体受阻滞所致早老型痴呆动物模型的建立

海马区内注射Ｋ－银环蛇毒素（Ｋ－ＢＧＴ）可造成小鼠学习记忆明显障碍,以建立早老性痴呆（ＡＤ）患者学习记忆缺损模型。对小鼠的损害作用随Ｋ－ＢＧＴ剂量增加而明显增加。水迷宫多项指标测试结果表明,Ｋ－ＢＧＴ损害组小鼠与对照组小鼠相比,空间学习和记忆能力显著下降。明暗回避反应实验结果也表明,Ｋ－ＢＧＴ损害小鼠潜伏期明显缩短,错误次数增多;两种检测方法均表明Ｋ－ＢＧＴ可导致小鼠学习记忆明显障碍,而且这种损害具有持久的作用。     

关于眼球轴线和角度的研究进展

在眼球这个复杂的光学系统中,存在着各种不同的轴线(视轴、光轴、瞳孔轴)和角度(Alpha角和Kappa角).视轴指连接光源和视网膜黄斑中心凹并通过节点的连线,瞳孔轴是经过瞳孔中心垂直角膜前平面的线,两者之间的夹角被称作Kappa角.Alpha角是指视轴和光轴之间的夹角.在屈光手术确定角膜削切中心的正确位置和斜视手术设计更为准确的矫正量时,Kappa角是一个很重要的参数;在白内障手术植入多焦点人工晶状体时,Alpha角和Kappa角是很重要的参数.近年来,眼科医生对Kappa角越来越关注,认为Kappa角的大小会影响植入多焦点人工晶状体患者的视觉质量.本文回顾Alpha角和Kappa角认识的历程,阐述两者的定义和影响因素,并对两者在眼科领域的应用进行综述.     

巴戟天水提取物对间充质干细胞成骨分化中OPG/RANKL表达的影响

目的 在成骨诱导条件下,探讨巴戟天水提取物对骨髓间充质干细胞(MSCs)中骨保护素(OPG)和核因子κB受体活化因子配体(RANKL)表达的影响.方法 取原代大鼠MSCs,行碱性磷酸酶(ALP)和茜素红染色,确定其成骨分化能力;使用0 (对照组)、10 g/L (M1组)及100 g/L (M2组)浓度的巴戟天水提取物处理MSCs细胞,在成骨诱导的条件下干预7 d,收集细胞培养液,并提取细胞的总RNA及总蛋白,采用ELISA法检测培养液中OPG/RANKL的分泌水平,采用Real-time PCR及Western Blot检测MSCs的OPG/RANKL基因和蛋白表达水平.结果 经ALP和茜素红染色可见MSCs着色明显.M1处理组和M2处理组OPG/RANKL基因表达水平较对照组上升,分别为(29.0±6.3)%和(60.0±5.4)%;同时M1及M2组细胞培养液中OPG/RANKL的蛋白分泌水平分别较对照组上升(17.0±4.1)%和(39.0±6.4)%;通过Western Blot检测,M1组及M2组OPG/RANKL的蛋白表达较对照组上升(20.0±4.3)%和(35.0±4.3)%.以上结果经统计学分析,其差异均有统计学意义(P<0.05).结论 巴戟天水提取物可以提升MSCs细胞分泌的OPG/RANKL水平,改善骨质疏松患者OPG/RANKL比例失衡状况,这是巴戟天抗骨质疏松的主要机制.     

N-乙酰半胱氨酸联合抗坏血酸对大鼠重症急性胰腺炎时急性肺损伤的作用

目的:探讨N-乙酰半胱氨酸(NAC)联合抗坏血酸对大鼠重症急性胰腺炎(SAP)时急性肺损伤(ALI)的作用及机制.方法:40只SD大鼠随机分为假手术(SO)组、SAP+ALI组、NAC治疗组、NAC+抗坏血酸治疗组4组.采用胰胆管逆行注射4%的牛磺胆酸钠(0.1 ml/100 g)诱导SAP+ALI模型,NAC治疗组于...     

脂肪组织TLR-4/NF-κB信号通路与高脂饮食诱导小鼠胰岛素抵抗的关系

目的采用高脂饮食诱导小鼠胰岛素抵抗,了解脂肪组织Toll样受体4（Toll-like receptor 4,TLR-4）、神经因子κB（nuclear factorκappa B,NF-κB）信号通路与胰岛素抵抗的关系。方法 C57BL/6雄性小鼠80只,随机分为2组,分别给予普通饮食和高脂饮食喂养,每组随机抽样分为4亚组,各5只小鼠,分别于喂养12周后监测体质量、空腹血糖、血清胰岛素水平;处死后取脂肪组织,经苏木精-伊红（Hematoxylin-Eosin,HE）染色观察脂肪组织形态变化;Western blot法检测小鼠脂肪组织TLR-4、NF-κB蛋白表达。免疫组化法检测肿瘤坏死因子α（tumor necrosis factorαlpha,TNF-α）及白细胞介素6（interleukin 6,IL-6）表达。结果高脂喂养小鼠胰岛素抵抗模型建立成功;高脂组发生胰岛素抵抗,对照组未发生胰岛素抵抗;高脂组小鼠的体质量、空腹血糖、胰岛素水平较对照组明显升高（P〈0.05）,脂肪组织HE染色显示脂肪细胞逐渐增大;脂肪组织TLR-4/NF-κB蛋白从第3天开始出现高表达,到第5天开始达到高峰,并且一直持续在较高水平,同时脂肪细胞也出现TNF-α、IL-6的明显表达。结论高脂饮食可激活脂肪细胞TLR-4/NF-κB信号通路,并与胰岛素抵抗之间具有关联性。