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91.
Prevalence of silent myocardial ischemia in asymptomatic individuals with subclinical atherosclerosis detected by electron beam tomography 总被引:3,自引:0,他引:3
Anand D. Vijay Lim Eric Raval Usha Lipkin David Lahiri Avijit 《Journal of nuclear cardiology》2004,11(4):450-457
BACKGROUND: Electron beam tomography coronary calcium imaging is an evolving technique for the early detection of coronary atherosclerosis, and recent studies have established its prognostic value in asymptomatic individuals. The relationship of coronary artery calcium scores (CAC) to obstructive coronary artery disease (CAD) has been poorly studied but is clinically relevant because it determines which individuals are likely to benefit from revascularization procedures. Hence, we prospectively evaluated the prevalence of myocardial ischemia in asymptomatic patients with cardiovascular risk factors and subclinical atherosclerosis. METHODS AND RESULTS: We studied 864 asymptomatic patients with no previous CAD but with cardiovascular risk factors, referred for electron beam tomography coronary calcium imaging to our institution over an 18-month period. From this group, 220 consecutive patients (85% men; mean age, 61 +/- 9 years; age range, 31-84 years) with moderate to severe atherosclerotic disease (coronary calcium score > or =100 Agatston units) were prospectively evaluated by technetium 99m sestamibi single photon emission computed tomography (SPECT). Patients were followed up (mean follow-up, 14 months) and data regarding their subsequent clinical management recorded. Of the 220 patients, 119 had moderate atherosclerosis (CAC score of 100-400 Agatston units) and 101 had severe atherosclerosis (CAC score > or =400 Agatston units). Abnormal SPECT findings were seen in 18% of patients with moderate atherosclerosis (n = 21) and 45% of patients with severe atherosclerosis (n = 45). Increasing severity of atherosclerosis was related to increasing ischemic burden (summed difference score = 1 +/- 0.2 for CAC score of 100-400 Agatston units and 3.2 +/- 0.5 for CAC score > or =400 Agatston units). In a multivariate linear regression model incorporating risk factors, CAC was the only predictor of silent ischemia. CONCLUSION: In comparison to previously published data, we detected a higher prevalence of silent ischemia even in patients with moderate coronary atherosclerosis (18%). This may reflect the differing risk factor profile of our patient population. When coronary calcium screening is used to preselect asymptomatic patients with cardiovascular risk factors for myocardial perfusion imaging, the optimum coronary calcium score threshold will depend on the population prevalence of risk factors and asymptomatic obstructive CAD. 相似文献
92.
JH-2000血液透析机研制 总被引:3,自引:0,他引:3
详细阐述国产JH-2000血液透析机的基本原理、组成和性能. 相似文献
93.
94.
W. B. Quay 《Journal of neural transmission (Vienna, Austria : 1996)》1981,52(1-2):107-115
Summary Quantitative aspects of the microanatomy of the pineal gland and other neuroendocrine and circumventricular structures were studied in a small, reproductively suppressed, female Naked Mole-rat from central Kenya, Africa. The atrophic pineal is the smallest in absolute size (0.002135 mm3) of any so far described in a species of rodent, and in size relative to body weight is second only to that of another tropical species. The subcommissural organ and posterior collicular recess are also relatively small and less well differentiated than those in most other examined rodent species. In contrast, the subfornical organ, OVLT and median eminence are large and well vascularized. It is concluded that the pineal in this species follows the previously described trend among rodents of relatively smaller size in species whose centers of distribution are in lower latitudes. Although the pineal is atrophic, the Naked Mole-rat still exhibits 24-hour and seasonally timed patterns of behavior and seasonal reproduction. However, in this species these events are probably cued by moisture, temperature and social factors rather than by photic information. 相似文献
95.
D. Le Elizabeth Eric R. Powers Jian-Ping Bin Howard Leong-Poi N. Craig Goodman Sanjiv Kaul 《Journal of nuclear cardiology》2007,14(2):207-214
Background The mechanism by which transmyocardial revascularization (TMR) offers clinical benefit is controversial. We hypothesized that
TMR ameliorates ischemia by reversing paradoxical catecholamine-induced vasoconstriction.
Methods and Results Chronic ischemic cardiomyopathy was created in 11 dogs by placing ameroid constrictors on the proximal coronary arteries and
their major branches. Six weeks later, 35 channels were created percutaneously in the left circumflex artery region, with
the left anterior descending artery region serving as control. At rest, wall thickening and myocardial blood flow did not
change in the treated region, whereas they deteriorated in the control bed. Contractile and myocardial blood flow reserve
increased in the treated region but deteriorated in the control region. There was diminished iodine 123 metaiodobenzylguanidine
uptake and a significant reduction in noradrenergic nerves in the treated region compared with the control region, with a
corresponding reduction in tissue tyrosine hydroxylase activity.
Conclusions We conclude that the absence of a catecholamine-induced reduction in MBF reserve and contractile reserve in the TMR-treated
region with associated evidence of neuronal injury indicates that the relief of exercise-induced ischemia after TMR most likely
results from reversal of paradoxical catecholamine-induced vasoconstriction. These findings may have implications in selecting
patients who would benefit from TMR.
Supported in part by grants from the National Institutes of Health (R01-HL66034 and K-08-HL074290-01). Bethesda. Md. The radio-labeled
microspheres were provided by DuPont Pharmaceuticals, North Billerica. Mass, and the ultrasound equipment was supplied by
Philips. Andover, Mass. Dr Leong-Poi was the recipient of a Fellowship Training Grant from the Canadian Institute of Health
Research and the Heart and Stroke Foundation of Canada. 相似文献
96.
Takuro Yoshikawa Yasuyuki Suzuki Yasuhiro Fujino Keitaro Kakinoki Shiri Li Tadahiro Goto Tomohiro Tanaka Ippei Matsumoto Tetsuya Sakai Yasuki Tanioka Hiroshi Yokozaki Yoshikazu Kuroda 《American journal of transplantation》2005,5(9):2135-2142
Small bowel transplantation (SBT) is associated with a high incidence of infectious complications because of ischemia/reperfusion (I/R) mucosal injury concomitant with potent immunosuppression. In this study, we evaluated whether the cavitary two-layer method (cTLM) could reduce I/R injury and allow early mucosal restoration, particularly after prolonged preservation and transplantation. Canine heterotopic segmental SBT was performed immediately without preservation (group 1), after 24-h preservation in UW solution (group 2) or by the cTLM (group 3). The graft samples were taken 1 h after reperfusion and on days 1, 4 and 7. We assessed graft mucosa with detailed microscopic and electromicroscopic analyses. In Group 3, histological injury and cell apoptosis after transplantation were significantly alleviated and rapidly recovered to a similar level of group 1. The mucosal restoration was morphologically completed within 4 days. In contrast, in group 2, more pronounced mucosal injury and delayed recovery were noted. Crypt cell proliferation activity was well maintained in groups 1 and 3 throughout the experimental period. Our ultrastructural analysis suggested that mitochondrial integrity achieved by the cTLM was a basal mechanism under the prompt mucosal restoration. The cTLM could reduce I/R injury, facilitate mucosal regeneration and restore the nearly normal structure early after SBT. 相似文献
97.
晶体心脏停搏液优于血液心脏停搏液对风湿性心脏病患者的心肌保护 总被引:1,自引:0,他引:1
目的比较血液心脏停搏液和晶体停搏液对风湿性心脏病患者心肌保护的效果,为临床选择提供依据。方法将75例择期手术的风湿性心脏病患者分为两组:血液心脏停搏液组(B-rh)和晶体心脏停搏液组(C-rh)。分别于术前1d,术后1,3,5,8d晨分别取静脉血,测定血清天门冬氨酸氨基转氨酶(AST),肌酸激酶(CK)及同工酶MB(CK-MB),乳酸脱氢酶(LDH)及同工酶1(LDH-1)。结果术前除B-rh的LDH略高于正常水平外其它心肌酶的测定结果均在正常范围;术后1d两组的心肌酶分别升高到术前的3~19倍(P<0.05);术后3d两组的CK-MB虽说已恢复到正常值,但五种心肌酶仍明显高于术前水平(P<0.05);术后5dC-rh的CK和CK-MB,B-rh的CK,CK-MB和AST与术前相比已无明显差别(P>0.05);术后8d两组的LDH与LDH-1仍未恢复正常(P<0.05)。两组间有显著差异的心肌酶释放均是B-rh的高。心肌酶的释放量与主动脉阻断时间(CCT)和体外循环时间(ECCT)呈良好的正相关。两组患者的年龄,体重和ECCT无明显差异(P>0.05),CCT以B-rh为短[(77.2±34.6)min比(61.7±26.7)min,P<0.05]。结论从心肌酶的释放来判断,晶体心脏停搏液优于血液心脏停搏液对风湿性心脏病患者的心肌保护效果。 相似文献
98.
上颌扩弓治疗纠正早期功能性下颌偏斜 总被引:7,自引:0,他引:7
目的:通过头颅定位后前位片(P-A)测量,探讨上颌扩弓纠正单侧后牙反牙合,改善早期功能性下颌偏斜. 方法:混合牙列或早期恒牙列,单侧后牙反牙合伴有或不伴有前牙反牙合, 下颌功能性偏斜患者16名,采用上颌Quad-Helix扩弓的方法,矫治前后头颅定位后前位片P-A测量分析,用统计软件处理数据. 结果:单侧后牙反牙合矫正后,下颌骨两侧结构不对称性有明显改善. 下颌骨两侧综合长度差亦减小(P<0.01),两侧下颌体长度差明显减小(P<0.01). 结论:混合牙列或早期恒牙列,由于单侧后牙反牙合导致的功能性下颌偏斜,采用扩大上颌牙弓,可以使下颌骨的不对称得到一定的改善,是早期纠正下颌功能性偏斜的有效手段. 相似文献
99.
保留后方韧带复合体在胸腰椎骨折治疗中的意义 总被引:1,自引:1,他引:0
[目的]探讨保留后方韧带复合体在胸腰椎骨折治疗中的意义。[方法]1998~2002年单一节段胸腰椎爆裂骨折治疗中保留后方韧带复合体44例,同期行胸腰椎爆裂骨折治疗切除后方韧带复合体者35例。两种方法分别有15例(定义为A组)和12例(定义为B组)行2次手术取出内固定物,比较AB两组间2次手术前后腰椎功能JOA评分。[结果]2次手术前腰椎功能JOA评分:A组平均24.5分(19~29分);B组平均22.8分(19~29分),二者无显著性差异(P〉0.05)。2次手术后JOA评分:A组平均24.8分(20~29分),B组平均17.5分(13~26分)。二组有显著性差异(P〈0.05)。[结论]胸腰椎骨折治疗中保留后方韧带复合体,利于术后腰椎功能恢复。 相似文献
100.
鼠脑缺血再灌注损伤炎症反应及环磷酰胺影响 总被引:8,自引:0,他引:8
目的 探讨脑缺血再灌注不同缺血区域炎症反应特点及环磷酰胺影响.方法 将大鼠随机分为假手术组、对照组、环磷酰胺预处理组,建立局灶性脑缺血再灌注模型.用免疫组化法和生化法观察额顶部皮质和基底节区P-选择素表达、髓过氧化物酶(MPO)活性变化;并进行TTC染色和HE染色.结果 (1)再灌注3h缺血侧额顶部皮质和基底节区出现P-选择素表达,12h达高峰.环磷酰胺预处理组和对照组相比较,差异无显著性(P>o.05).(2)再灌注12h以后MPO活性明显升高.基底节区的MPO活性在再灌注48h达到高峰后下降.额顶部皮质MPO活性在再灌注24h达到高峰后至96h仍维持较高水平.和对照组相比较,环磷酰胺预处理组MP(活性升高受抑制(P<0.05).(3)环磷酰胺预处理可显著缩小脑梗死体积(P<0.05).结论 (1)脑缺血再灌注损伤存在主动性炎症反应,额顶部皮质比基底节区的炎症反应更持久和剧烈.(2)环磷酰胺减少缺血侧中性粒细胞浸润数量,具有神经保护作用,但不直接影响P-选择素的表达. 相似文献