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111.
112.
NMR microscopy is currently being used as an investigational tool for the evaluation of micromorphometric parameters of trabecular bone as a possible means to assess its strength. Since, typically, the image voxel size is not significantly smaller than individual trabecular elements, partial volume blurring can be a major complication for accurate tissue classification. In this paper, a Bayesian segmentation technique is reported that achieves improved subvoxel tissue classification. Each voxel is subdivided either into eight subvoxels twice the original resolution, or up to four subvoxels along the transaxial direction and the subvoxels optimally classified as either bone or marrow. Based on a statistical model for partial volume blurring, the likelihood for the number of marrow subvoxels in each voxel can be computed on the basis of its measured signal. To resolve the ambiguity of the location of the marrow subvoxels, a Gibbs distribution is introduced to model the interaction between the subvoxels. Neighboring subvoxel pairs with the same tissue label are encouraged, and pairs with distinct labels are penalized. The segmentation is achieved by maximizing the a posteriori probability of the label image using the block ICM (iterative conditional mode) algorithm. The potential of the proposed technique is demonstrated in real and synthetic NMR microscopic images. 相似文献
113.
114.
L. A. Cassis L. P. Dwoskin 《Journal of neural transmission (Vienna, Austria : 1996)》1994,98(2):159-164
Summary To determine if acute or chronic (21 days) losartan (10mg/kg, s.c.) regulates the renin-angiotensin system in interscapular brown adipose tissue, angiotensin II (AII) content and [3H]overflow from slices preloaded with [3H]norepinephrine were examined. Acute or chronic losartan administration had no effect on AII content. AII increased evoked [3H]overflow from slices from control rats. Losartan administration did not alter basal [3H]outflow or evoked [3H]overflow. Acute losartan administration inhibited AII-induced enhancement of evoked [3H]overflow. Tolerance developed to the inhibitory effect of losartan following chronic administration.Supported by a grant from the American Heart Association (Local Kentucky Affiliate) and by a gift from DuPont Merck Pharmaceuticals. Portions of this work have been presented in abstract form [The Pharmacologist 34(3): 157, 1992] 相似文献
115.
Fluid-fluid levels in cavernous hemangioma of soft tissue 总被引:3,自引:0,他引:3
Shigeru Ehara M.D. Miyuki Sone Yoshiharu Tamakawa Jun Nishida Masataka Abe Junichi Hachiya 《Skeletal radiology》1994,23(2):107-109
Five cases of cavernous hemangioma with fluid-fluid levels on magnetic resonance imaging and/or computed tomography are reported. The signal characteristics were those of blood and histological analysis of the fluid-fluid levels showed that they were blood-filled cavities in the tumor. Although this finding itself is not specific, it may help in confirming the diagnosis of cavernous hemangioma. 相似文献
116.
基质金属蛋白酶及其抑制剂在子宫内膜癌的侵袭和转移中发挥着重要的作用。肿瘤的新生血管对肿瘤的发生、发展、转移及预后有着重要作用。微血管密度是衡量血管生成的定量指标。基质金属蛋白酶抑制剂可抑制血管的生成和MMPs对细胞外基质的降解。现将他们与子宫内膜癌的关系综述如下。 相似文献
117.
脱细胞异体皮肤细胞外基质——医用组织补片在美容外科的应用 总被引:4,自引:0,他引:4
目的介绍脱细胞异体皮肤细胞外基质医用组织补片在美容外科中的临床应用经验。方法自2002年3月至2005年10月,应用脱细胞异体皮肤细胞外基质医用组织补片,对患者不同部位进行填充的美容手术,其中头面部填充于皮下浅筋膜层,唇部、颏部、唇裂合并牙槽裂部填充于皮下深筋膜层或肌肉浅层,隆乳术中用于胸大肌减张。结果本组115例患者经1~27个月随访,1例唇裂合并牙槽裂者因补片填充量不足凹陷未完全矫正;1例鼻唇沟填充者其左侧出现血肿、局部出现硬结,于2个月后将左侧假体取出重新填充,但术后6个月仍有不平整,其余患者均获得良好的美容效果。结论脱细胞异体皮肤细胞外基质医用组织补片可以广泛地应用于美容外科的临床填充术。 相似文献
118.
J. STEFFEL†‡ C. ARNET† A. AKHMEDOV† S. M. ISELI† T. F. LÜSCHER†‡ F. C. TANNER†‡ 《Journal of thrombosis and haemostasis》2006,4(11):2452-2460
BACKGROUND: Histamine plays an important role in vascular disease. Tissue factor (TF) expression is induced in vascular inflammation and acute coronary syndromes. OBJECTIVES: This study examined the effect of histamine on tumor necrosis factor-alpha- (TNF-alpha-) vs. thrombin-induced endothelial TF expression. METHODS AND RESULTS: Histamine (10(-8)-10(-5) mol L-1), TNF-alpha (5 ng mL-1), and thrombin (1 U mL-1) induced TF expression in human endothelial cells. Although TF expression by TNF-alpha and thrombin was identical, histamine augmented TNF-alpha-induced expression 7.0-fold, but thrombin-induced expression only 2.6-fold. Similar responses occurred with TF activity. The H1-receptor antagonist mepyramine abrogated these effects. Differential augmentation by histamine was also observed at the mRNA level. Histamine-induced p38 activation preceded a weak second activation to both TNF-alpha and thrombin. Histamine-induced c-Jun NH2-terminal kinase (JNK) activation was followed by a strong second activation to TNF-alpha, and less to thrombin. Selective inhibition of this second JNK activation by SP600125 reduced TF induction to histamine plus TNF-alpha by 67%, but to histamine plus thrombin by only 32%. Histamine augmented TNF-alpha- and thrombin-induced vascular cell adhesion molecule 1 (VCAM-1) expression to a similar extent. Consistent with this observation, VCAM-1 induction to TNF-alpha and thrombin was mediated by p38, but not by JNK. CONCLUSIONS: Histamine differentially augments TNF-alpha- vs. thrombin-induced TF expression and activity, which is mediated by the H1-receptor, occurs at the mRNA level, and is related to differential JNK activation. 相似文献
119.
A M Abdel Gader A A Al-Mishari S A Awadalla N M Buyuomi T Khashoggi M Al-Hakeem 《International journal of gynaecology and obstetrics》2006,95(3):248-253
OBJECTIVE: To clarify the role played by tissue factor pathway inhibitor (TFPI) in pregnancy hypertension. METHODS: Using enzyme-linked immunosorbent assays, hemostatic measurements were obtained for women with pre-eclampsia (n=51), nonproteinuric hypertension of pregnancy (n=62), postpartum pre-eclampsia 24 h after childbirth (n=31), and no hypertension (healthy pregnant controls, n=100). RESULTS: There was a significant increase in circulating free TFPI levels in women with pre-eclampsia (9.7+/-6.2 ng/mL) or nonproteinuric hypertension of pregnancy (8.3+/-5.3 ng/mL) compared with healthy controls (5.3+/-2.1 ng/mL). In women with pre-eclampsia the levels remained elevated after placental delivery (10.6+/-4.0 ng/mL). Free protein S levels were significantly higher in women with pre-eclampsia (40.0%+/-10.7%), nonproteinuric hypertension of pregnancy (37.1%+/-12.5%), or postpartum pre-eclampsia (39.3%+/-9.1%) than in healthy pregnant controls (32.2%+/-8.5%). CONCLUSION: Increased levels of the physiologically active free forms of TFPI and free protein S, 2 coagulation inhibitors, may protect women with pregnancy-induced hypertension from the risks of hemostatic activation. 相似文献
120.