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1.
The purpose of this study was to determine whether the thickness of the intimal hyperplasia (IH) layer that accumulates within Palmaz-Schatz stents is dependent on stent size. Intravascular ultrasound (IVUS) and quantitative angiographic (QCA) studies were performed after stent implantation and at follow-up (5.4 +/- 3.8 months) in 161 patients with 177 lesions treated with 221 Palmaz-Schatz stents. Stent and lumen cross-sectional area (CSA) were measured. IH CSA and thickness at follow-up were calculated and compared with stent CSA and circumference. Maximum IH CSA and thickness were measured at the smallest follow-up lumen CSA; mean IH CSA and thickness was averaged over the length of the stent. Maximum IH CSA measured 4.8 +/- 2.4 mm2, and mean IH CSA measured 2.8 +/- 2.2 mm2. Maximum IH thickness (at the smallest follow-up lumen CSA) measured 0.60 +/- 0.36 mm, and mean IH thickness (over the length of the stent) measured 0.30 +/- 0.19 mm. There was a weak, but significant correlation between mean and maximum IH CSA versus stent CSA (r = 0.215, p <0.0001 and r = 0.355, p <0.0001, respectively). However, there was no correlation between mean or maximum IH thickness versus stent CSA (r = 0.018, p = 0.643 and r = 0.056, p = 0.463, respectively) or stent circumference (r = 0.002, p = 0.956 and r = 0.069, p = 0.361, respectively). IH thickness was found to be independent of the stent size. This explains the known higher frequency of restenosis in smaller stents compared with larger stents.  相似文献   

2.
[Correction Notice: An erratum for this article was reported in Vol 103(1) of Behavioral Neuroscience (see record 2008-10623-002). The plate for this article appears on page 996. The information should read, "Plate B. Photographs of the dorsal side of the brains showing the minimum (top) and maximum (bottom) extent of the lesion produced unilaterally in the sham group (left) and bilaterally in the single- and two-stage groups (right)."] Multiple-staged brain lesions produce fewer and smaller behavioral effects than single surgery (the serial lesion effect, SLE). Two hypotheses were tested: the reduced deficit hypothesis and the serial recovery hypothesis. Effects of lesions of the medial frontal cortex on sensorimotor behavior were investigated in 7 rats that received bilateral damage in single surgery, 16 in 2 unilateral stages separated by 3 wks, or 5 with unilateral damage followed 3 wks later by sham surgery. Unilateral damage produced deficits on the contralateral side in response to visual, tactile, and olfactory stimuli and impairments in roll-over and paw withdrawal responses. All impairments except visual placement recovered over the next 3 wks. A 2nd unilateral lesion on the contralateral side produced the same symptoms on the opposite side. Bilateral damage incurred in a single stage produced the same deficits on both sides. Because the effects of the 2nd unilateral lesion in the 2-stage group produced comparable contralateral effects to those produced in the single-stage group, but no reinstatement of ipsilateral deficits, the reduced deficit hypothesis was rejected. It was concluded that SLE occurred as a result of serial recovery of the deficits. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

3.
BACKGROUND: Target lesion calcium is a marker for significant coronary artery disease and a determinant of the success of transcatheter therapy. METHODS AND RESULTS: Eleven hundred fifty-five native vessel target lesions in 1117 patients were studied by intravascular ultrasound (IVUS) and coronary angiography. The presence, magnitude, location, and distribution of IVUS calcium were analyzed and compared with the detection and classification (none/mild, moderate, and severe) by angiography. Angiography detected calcium in 440 of 1155 lesions (38%): 306 (26%) moderate calcium and 134 (12%) severe. IVUS detected lesion calcium in 841 of 1155 (73%, P < .0001 versus angiography). The mean arc of lesion calcium measured 115 +/- 110 degrees; the mean length measured 3.5 +/- 3.7 mm. Target lesion calcium was only superficial in 48%, only deep in 28%, and both superficial and deep in 24%. The mean arc of superficial calcium measured 85 +/- 108 degrees; the mean length measured 2.4 +/- 3.4 mm. Three hundred seventy-three of 1155 reference segments (32%) contained calcium (P < .0001 compared with lesion site). The mean arc of reference calcium measured 42 +/- 80 degrees; the mean length measured 1.7 +/- 3.6 mm. Only 44 (4%) had reference calcium in the absence of lesion calcium. Angiographic detection and classification of calcium depended on arcs, lengths, location, and distribution of lesion and reference segment calcium. By discriminant analysis, the classification function for predicting angiographic calcium included the arc of target lesion calcium, the arc of superficial calcium, the length of reference segment calcium, and the location of calcium within the lesion. This model correctly predicted the angiographic detection of calcification in 74.4% of lesions and the angiographic classification (none/moderate/severe) of calcium in 62.8% of lesions. CONCLUSIONS: IVUS detected calcium in > 70% of lesions, significantly more often than standard angiography. Although angiography is moderately sensitive for the detection of extensive lesion calcium (sensitivity, 60% and 85% for three- and four-quadrant calcium, respectively), it is less sensitive for the presence of milder degrees.  相似文献   

4.
BACKGROUND: Intravascular ultrasound imaging of the pulmonary arteries has been demonstrated to be a reliable method of quantifying vessel diameter, luminal area and pulsatility. Simultaneous measurement of flow velocity and its response to vasodilators allows the relationship between morphology and functional compromise to be studied, especially endothelial dysfunction. METHODS: In 51 patients (mean age = 49.8 +/- 12.6 years, 17 female) we performed right heart catheterization and simultaneous intravascular ultrasound of pulmonary artery branches. The patients were divided in two groups: group 1 with normal pulmonary artery pressure and pulmonary vascular resistance, and group 2 with pulmonary hypertension (peak pulmonary artery pressure > 30 mmHg and/or mean pulmonary artery pressure > 20 mmHg). Vessel wall and lumen were studied using a 2.9 F intravascular ultrasound catheter with a 30 MHz phased array transducer. Measurement of blood flow velocity was accomplished by a Doppler flow wire (0.018 inch). The maximal flow change during acetylcholine infusion (adjusted to 10(-6); 10(-5), and 10(-4) M concentration in the blood vessel) was measured. RESULTS: There were no significant differences between groups 1 and 2 with respect to age (48.5 +/- 14.3 years vs 50.3 +/- 12.3 years; P = ns), gender (4 female/8 male vs 13 female/26 male; P = ns), luminal area of the vessel segment in which the intravascular ultrasound measurements were obtained (11.8 +/- 6.1 mm2 vs 16.7 +/- 14.3 mm2; P = ns), internal diameter (3.9 +/- 1.2 mm vs 4.2 +/- 1.7 mm; P = ns), and external diameter (6.1 +/- 1.3 mm vs 6.9 +/- 2.1 mm; P = ns). Cross-sectional images of the pulmonary artery wall demonstrated a single ring with high echodensity with a thin inner layer regarded as intima in group 1. In contrast, the majority of patients (n = 35/39) in group 2 demonstrated a thickening of the intimal layer and/or a disturbance of layering of the echogenic arterial wall. The relative wall thickness was higher in group 2 than in group 1 (22.5 +/- 10.4% vs 15.3 +/- 6.5%; P < 0.05). There were no significant correlations between pulmonary artery pressure and wall thickness pulmonary artery pressure and area change in the cardiac cycle, acetylcholine-dependent increase in pulmonary flow and morphological changes in the vessel wall. CONCLUSION: We conclude that intravascular ultrasound is capable of detecting morphological changes in the pulmonary vessel wall in pulmonary hypertension and that vessel wall hypertrophy of small pulmonary segment arteries, as detected by intravascular ultrasound, is not predictive of functional vasodilatory response of resistance vessels of the same vessel area.  相似文献   

5.
Recent evidence has suggested that depressive symptomatology is a risk factor for the development of coronary heart disease (CHD) in patients with diabetes mellitus, although little is understood about mechanisms that may explain this association. The Pittsburgh Epidemiology of Diabetes Complications (EDC) Study is a natural history study of 658 men and women with childhood-onset Type I diabetes. Participants from the EDC Study who reported the fewest depressive symptoms on the Beck Depression Inventory at baseline examination were least likely to develop CHD over 10 years. Differences in insulin resistance, autonomic dysregulation, inflammation, smoking, and complications associated with Type I diabetes appear to help explain this relationship. Future research should clarify causal pathways between depressive symptomatology, behavioral and physiological processes, and CHD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

6.
OBJECTIVE: Before balloon dilation, failure of compensatory enlargement and even arterial shrinkage are frequently observed at the lesion site in response to plaque accumulation. Balloon angioplasty may be regarded as artificial remodeling to enlarge the artery. The prevalence of the different types of arterial wall remodeling after applied stretch by balloon angioplasty is unknown. METHODS AND RESULTS: In 181 patients an intravascular ultrasound study was performed after coronary balloon angioplasty (n = 200 lesions). The vessel area was measured at a proximal and distal reference site and at the lesion site. Subsequently, the relative vessel area [(Vessel area lesion site)/Vessel area reference site) x 100] was calculated. Lesions were classified in three groups on the basis of their relative vessel areas: > or =105%, <105% but >95%, and < or =95%. A relative vessel area > or =105%, indicating enlargement compared with the reference site, was observed in 84 (44%) lesions. A relative vessel area <105% but >95% was observed in 43 (22%) lesions. A relative vessel area < or =95%, indicating "shrinkage" compared with the reference site, was observed in 66 (34%) lesions. CONCLUSIONS: After balloon angioplasty, the vessel area was found to be smaller compared with the reference site in 34% of the lesions. This small vessel area at the lesion site compared with a reference site may be a reflection of insufficient stretch by balloon angioplasty.  相似文献   

7.
BACKGROUND: The non-uniform extent and distribution of atherosclerotic plaque at bifurcations have been described by necropsy studies and they are related to local blood-flow disturbances. Systematic evaluation of plaque extent and distribution upstream and downstream of major coronary side-branches has not yet been evaluated in vivo. METHODS: We used intravascular ultrasound imaging in 41 patients with atherosclerotic disease to study the region of 73 major coronary side-branches at 2 mm increments proximal and distal to the side-branch (657 images: 73 at origin of side-branch; 292 proximal; 292 distal). The maximum (MXT) and minimum (MINT) plaque thickness and the plaque burden percentage (% PB) were measured in all the segments. The angle of distribution of maximum plaque thickness with respect to the origin of the side-branch was determined in each cross-section and assigned to S1 when located on the semicircle in the direction of the origin of the side-branch and to S2 when located on the opposite wall. RESULTS: The mean value of maximum plaque thickness and the plaque burden percentage were similar at the origin and in the two adjacent segments proximal and distal to the side-branch (1.0 +/- 0.48 mm, 1.06 +/- 0.48 mm and 0.98 +/- 0.48 mm; 45 +/- 19%, 46 +/- 19% and 44 +/- 18%). In distal sites of analysis, the plaque was more frequently eccentric in comparison to proximal sites (presence of an arc of plaque-free wall: 79% versus 62% in very distal and in very proximal sites respectively; p < 0.05). The prevalence of maximum plaque in S2 was higher at the origin (84%) and in adjacent distal segments (86%) as compared with the adjacent proximal segments (60%; p < 0.0001). CONCLUSIONS: The distribution of plaque is influenced by the origin of a major coronary side-branch in patients with coronary atherosclerosis: in distal sites the location of maximum plaque is almost always eccentrically distributed on the wall opposite the take-off.  相似文献   

8.
Reports an error in "Recovery of sensorimotor function after frontal cortex damage in rats: Evidence that the serial lesion effect is due to serial recovery" by John M. de Castro and Mark C. Zrull (Behavioral Neuroscience, 1988[Dec], Vol 102[6], 843-851). The plate for this article appears on page 996. The information should read, "Plate B. Photographs of the dorsal side of the brains showing the minimum (top) and maximum (bottom) extent of the lesion produced unilaterally in the sham group (left) and bilaterally in the single- and two-stage groups (right)." (The following abstract of the original article appeared in record 1989-28759-001.) Multiple-staged brain lesions produce fewer and smaller behavioral effects than single surgery (the serial lesion effect, SLE). Two hypotheses were tested: the reduced deficit hypothesis and the serial recovery hypothesis. Effects of lesions of the medial frontal cortex on sensorimotor behavior were investigated in 7 rats that received bilateral damage in single surgery, 16 in 2 unilateral stages separated by 3 wks, or 5 with unilateral damage followed 3 wks later by sham surgery. Unilateral damage produced deficits on the contralateral side in response to visual, tactile, and olfactory stimuli and impairments in roll-over and paw withdrawal responses. All impairments except visual placement recovered over the next 3 wks. A 2nd unilateral lesion on the contralateral side produced the same symptoms on the opposite side. Bilateral damage incurred in a single stage produced the same deficits on both sides. Because the effects of the 2nd unilateral lesion in the 2-stage group produced comparable contralateral effects to those produced in the single-stage group, but no reinstatement of ipsilateral deficits, the reduced deficit hypothesis was rejected. It was concluded that SLE occurred as a result of serial recovery of the deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

9.
Extensive prosthodontic treatment often requires fabrication of long-term provisional restorations. Numerous materials and techniques have been described for prolonged insertion of interim restorations. This article describes a procedure for fabrication of long-term reinforced heat-processed provisional restorations based on a diagnostic wax-up. Reinforced heat-processed provisional restorations reduced flexure, which minimizes progressive loss of cement and diminished the possibility of recurrent decay. Occlusal stability and vertical dimension were maintained because of greater wear resistance. Occlusion, tooth contours, and pontic design developed in the provisional restoration were duplicated in the definitive restoration. The use of a matrix from a diagnostic wax-up facilitated fabrication of the prosthesis, and made the procedure less time-consuming and more predictable.  相似文献   

10.
The relationship between parental divorce occurring during adolescence and young adult psychosocial adjustment was examined, as was the role of family process variables in clarifying this relationship. Participants were young Caucasian adults from divorced (n = 119) and married (n = 123) families. Assessments were conducted during adolescence and 6 years later during early adulthood. Young adults from married families reported more secure romantic attachments than those from divorced families; however, differences were not evident in other domains of psychosocial adjustment after demographic variables were controlled. Three family process variables (parent-adolescent relationship, interparental conflict, and maternal depressive symptoms) were examined as potential mediators and moderators of the association between parental divorce and young adult adjustment. No evidence supporting mediation or moderation was found; however, the parent-adolescent and parent-young adult relationships, particularly when the identified parent was the father, emerged as significant predictors of young adult psychosocial adjustment.  相似文献   

11.
The unique nature of the ORBIS teaching mission is reflected in many arenas. The ORBIS organization recognizes that the nurse's role is critical to achieving their mission of preventing blindness through education, hence the emphasis on nurse education. The roles of the head nurse, nurse educator, staff nurses, and the biomedical engineering department are discussed briefly with emphasis on the needs assessment and the different programs offered to meet the identified needs.  相似文献   

12.
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14.
In 2 experiments with male Sprague-Dawley rats, alloxan-diabetic rats were hyperphagic when fed diets containing little fat, but they ate normal amounts of food when given diets rich in fat. Normal Ss increased food intake to the same degree when the caloric density of their diet was decreased by reducing the content of fats or carbohydrates in isocaloric amounts. Diabetic Ss did not respond substantially to changes in caloric density of their diet which were produced by altering the content of dietary carbohydrates, but they systematically increased food intake as the amount of fat in their diet was reduced. Diabetic Ss ate normal amounts of a high-fat diet despite continued loss of nutrients in urine and persisting impairments in glucose utilization, fat storage, and liver glycogen deposition. Findings suggest that hyperphagia in experimental diabetes mellitus is a compensatory response to a lack of utilizable fat fuels rather than the result of a metabolic disturbance per se. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

15.
BACKGROUND AND PURPOSE: Vasospasm in aneurysmal subarachnoid hemorrhage results in proliferative vasculopathy. Systemic hypertension also causes vascular hypertrophy. Both of these histological changes can lead to rigidity of the cerebrovascular system, reducing its autoregulatory capacity. METHODS: Blood flow velocity (BFV) in the middle cerebral artery at rest and cerebrovascular reserve capacity (CVRC) (percent rise in BFV after acetazolamide stimulation) measured by means of transcranial Doppler sonography were studied many years after aneurysmal subarachnoid hemorrhage in patients with proven cerebral vasospasm (mean BFV > 160 cm/s). The BFV under resting conditions and the CVRC values of the ipsilateral and the contralateral hemispheres were measured in 29 patients (mean age, 43 years; mean follow-up, 4.6 years) and compared with those of control subjects. RESULTS: Persistent high BFV (> 120 cm/s) was found in three patients in the peripheral branch of the ipsilateral middle cerebral artery. In the main trunks of the arteries of the anterior circle of Willis, BFV was normal in all cases. CVRC was normal in all patients (ipsilateral, 52 +/- 21%; contralateral, 56 +/- 17%); values did not differ significantly from each other or from the control value (45 +/- 18%). The higher value of CVRC on the contralateral side was found to be statistically significant in selected groups (hypertensive patients and patients with residual infarct on late CT). CONCLUSIONS: Proliferative vasculopathy developed at the time of vasospasm must have resolved and did not reduce late vasoreactivity. Comorbidity with hypertension also did not seem to influence the late vasoreactivity toward normalization.  相似文献   

16.
In order to identify previously undiagnosed cases of non-insulin dependent diabetes (NIDDM) in general practice, we measured non-fasting blood-glucose in all risk patients (n = 1,790) between 35-69 years old belonging to 29 general practices in Kolding. Patients at risk for NIDDM were defined as those suffering from one or more of the following: overweight, arterial hypertension, coronary heart disease, hyperlipidaemia, stroke, gout, cataract, Dupuytren's contracture, peripheral atherosclerosis or recurrent urinary- or skin-infections. A positive result, defined as a non-fasting blood-glucose of > or = 8.0 mmol/l using the same stix-lot-nr. on Refloflux S machines, was found in 86 individuals. These were then followed up with two fasting blood-glucose measurements carried out in a central laboratory, whereby 34 patients with NIDDM were identified. The newly-diagnosed NIDDM patients mostly suffered from diseases related to the insulin resistance syndrome, and we thus recommend measurement of non-fasting blood-glucose as a screening procedure in such patients. When carrying out measurements in general practice, it is important to know the precision and accuracy of the apparatus used.  相似文献   

17.
Arteries may demonstrate compensatory enlargement in response to plaque accumulation. It has been proposed that enlargement is achieved by the expansion of the nondiseased (plaque-free) vessel wall. In this study, we assessed this hypothesis. Post mortem, 32 atherosclerotic coronary arteries (left anterior descending, n = 10; left circumflex, n = 11; and right coronary, n = 11) and 54 atherosclerotic femoral arteries were pressure fixed. Cross sections (coronary arteries, n = 537; femoral arteries, n = 1602) were obtained for analysis every 2.5 mm for the coronary arteries and every 5.0 mm for the femoral arteries. From these cross sections, we determined the degree of remodeling and an eccentricity index. Finally, we measured the extent of plaque-free vessel wall. The plaque-free vessel wall was defined as (1) no plaque present or (2) plaque thickness < 0.5 mm. A very weak, negative correlation was observed between the degree of remodeling and the extent of the plaque-free vessel wall (coronary arteries: no plaque r2 = .13, P < .01; < 0.5 mm plaque r2 = .15, P < .05; femoral arteries: no plaque r2 = .02, P < .01; < 0.5 mm plaque r2 = 0.04, P < .01). The degree of remodeling did not correlate with the eccentricity index (coronary arteries r2 = .002, P > .05 and femoral arteries r2 = .001, P > .05). Thus, compensatory enlarged segments did not reveal a larger circumference of plaque-free vessel wall compared with segments that failed to enlarge. This study provides no support for the hypothesis that nondiseased vessel-wall expansion is responsible for compensatory enlargement in atherosclerotic arteries.  相似文献   

18.
Eight streptozotocin-injected Wistar rats and eight controls were fixed by whole-body perfusion 4 months after beginning of the experiment, the nervus radialis was dissected and processed for light and electron microscopy. After light-microscopic study standard photographs of nerve cross sections were measured by means of a semiautomatic image analyzer. The following measurements were obtained: (1) surface of fibers, axons, and myelin sheaths, (2) ratio of myelin to axon surface, and (3) percent of endoneural space. Group means and standard deviations were calculated, and cumulated size class distributions were made. Representative nerve specimens from all animals were also studied by electron microscopy. The quantitative study revealed in the diabetics a severe reduction of the average myelin surface, a mild increase of axonal cross section and of endoneural space, a reduction of myelin/axon ratio and a mild reduction in cross section of the nerve. Ultrastructural lesions of minor degree were found in the cytoplasm of Schwann and mesenchymal cells, no lesion was observed in axons. These findings demonstrate the presence of neuropathy 4 months after induction of diabetes and support the pathogenetic role of the Schwann cell in our experimental model.  相似文献   

19.
During the performance of PTCA, the operator must be able to differentiate true complications from pseudocomplications. Mechanical coronary shortening and vessel wall invagination due to accordion effect, "pseudo-transection", dissection, coronary spasm, and localized thrombosis are sources of iatrogenic obstruction during angioplasty. We report a case in which straightening of a right tortuous coronary artery during angioplasty produced an iatrogenic lesion that has a typical invaginate appearance. Conservative management is indicated in the absence of definitive angiographic aspect of vessel trauma, because they disappear after withdrawal of angioplasty equipment or adequate management of the guidewire.  相似文献   

20.
BACKGROUND: A cost- and time efficient ultrasound-Doppler-test is introduced to evaluate the function of autonomic innervation of the upper limb. A voluntary inspiratory vasoconstrictor episode (VICE) after a provoked deep inspiration, transmitted via sympathetic nervous system, can be demonstrated at the radial artery using basic Doppler equipment. PATIENTS AND METHOD: VICEs were investigated in 30 healthy subjects (group A), in 20 patients with diabetes mellitus without clinical signs of polyneuropathy (group B) and in 20 patients with clinically manifest polyneuropathy (group C). RESULTS: In all healthy subjects a two minutes arterial occlusion led to a decrease of resistance index (RI) lower than 0.9 indicating sufficient hyperemia. RI during VICE increased to 1.0 in all healthy subjects. In 50% of the patients of group B as well as in 50% of the patients of group C the test revealed abnormal findings suggesting a disorder of the functional peripheral neurovascular unity.  相似文献   

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