首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Dilated cardiomyopathy is a common cause of heart failure with systolic dysfunction. Medications used to treat this condition are usually for symptomatic relief. We studied the effect of atenolol in heart failure caused by dilated cardiomyopathy in a double blinded randomized fashion. There were 17 males and 5 females. All patients underwent right and left heart catheterization, coronary angiography, endomyocardial biopsy, exercise testing and doppler echocardiography. By 3 months, atenolol significantly reduced resting and exercise heart rate and pulmonary capillary wedge pressure. There was no difference in exercise capacity. We conclude from this study that atenolol improve hemodynamic condition in patients with dilated cardiomyopathy without improving exercise capacity during this short observation period.  相似文献   

2.
3.
The mean blood pressure is an accurate estimate of the end-systolic aortic pressure in children. The aim of this study was: 1) to assess the relationship between the pressure at the incisura (PIAo) and the mean (MAoP) and pulse (PAoP) pressures of the supravalvular aorta in adults: and 2) to evaluate MAoP as an estimate of PIAo in adults. High fidelity pressure recordings were carried out in the supravalvular aorta in 17 men. The pressures were measured at rest in 10 consecutive beats and. In 6 subjects, during a Valsalva manoeuvre. At rest, PIAo was greater than the MAoP (109 +/- 17.9 versus 99.6 +/- 12.5 mmHg, p = 0.0001). There was a positive linear correlation between PIAo and MAoP (r = 0.93) and between PIAo and PAoP (r' = 0.77) whereas no correlation was observed between PIAo and heart rate, cardiac output or estimated total systemic arterial compliance. A beat-to-beat relationship was observed between PIAo and MAOP: 1) at rest in 16 of the 17 subjects and 2) in each subject who performed a Valsalva manoeuvre. Both at rest and during Valsalva, MAOP underestimated PIAo significantly, especially when PIAo was increased (p = 0.0001). The authors conclude that end-systolic supraaortic pressure is mainly related to the mean component of aortic pressure. MAOP slightly but constantly underestimated PIAo and this should lead to caution in assimilating MAOP to end-systolic aortic pressure in adults, especially in subjects with very high aortic pressures.  相似文献   

4.
Describes a mechanism by which content and structure interact. In particular, semantic analyses of a passage are involved in the identification of the passage's structure. To examine the plausibility of the proposed mechanism, stories were constructed in which minor variations in content influenced the kind of relationship existing between statements and presumably varied the stories' episode structures. The stories consisted of 4 episodes (the basic higher order unit of recent story grammars), which were either logically related or logically independent. 20 1st and 20 3rd graders were told the stories and asked to retell them. Ss could more accurately recall the structure of the logically organized episodes than that of the temporally listed episodes. The introduced variations in story content, therefore, did influence the stories' processing. Other measures of structure, namely, those describing the organization of information within the episodes, indicate that the findings are more parsimoniously explained in terms of passage structure than in terms of an ill-defined set of semantic situations. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

5.
In this study, significant correlations were discovered between the following three parameters: (i) pH values of human hair, (ii) K, Ca, Mg, Zn contents of human hair and (iii) sex. We also discovered that most trace elements are not significantly correlated with hair pH.  相似文献   

6.
The aortic arch has 3D distortions in the transverse arch in the axial view, and we previously reported that this distortion is a risk factor in the pathogenesis of arch aneurysms. In this study, we evaluated blood flow and movement of the aortic arch. In 10 healthy young volunteers, ECG-gated cine magnetic resonance imaging was carried out in the axial plane of the transverse arch, the coronal plane of the ascending arch, and the long axial plane along the entire arch. 1. Left anterolateral movements around the midpoint of the transverse arch in the systolic phase were observed in all of the men (6.3 +/- 1.59 mm) and women (4.8 +/- 0.73 mm). 2. A jet flow was detected in the systolic phase along the right side of the aortic wall. At the top of the plane, this jet flow turned to the left in a clockwise rotation in the anterior view. 3. In the long axial plane, a turbulent flow in the systolic phase was observed distal to the left subclavian arterial orifice in 6 of the 7 cases. In conclusion, this turbulent flow and left anterolateral wall motion of the transverse arch are due to anatomical three-dimensional distortion of the transverse arch. We propose that these phenomena may be important risk factors in the pathogenesis of arch aneurysms.  相似文献   

7.
8.
Leptin released from adipose tissue is believed to participate in a negative feedback loop regulating appetite, and malfunction of this mechanism could lead to obesity. We measured plasma leptin and body composition (dual energy x-ray absorptiometry) in 70 healthy subjects, divided into 3 age groups (young, 25 +/- 1 yr; middle-aged, 53 +/- 1 yr; old, 70 +/- 1 yr), while on a 5-day weight-maintaining diet. Pairwise correlations were assessed using product-moment correlation, and regression analysis was used to evaluate relationships between leptin and other variables. Leptin concentrations and relative body fat content were correlated in young females (r = 0.71; P = 0.009) and in young males (r = 0.76; P = 0.007), but not in the combined middle-aged and elderly groups (r = 0.19; P = 0.36 and r = 0.19; P = 0.38 in females and males, respectively). Regression analysis showed a clear correlation between circulating leptin and relative fat mass in the young subjects (P = 0.0001), but not in the older subjects (P = 0.199). We conclude that body fat content in young subjects correlates with plasma leptin in both genders, whereas this relationship is disrupted in elderly subjects, thus possibly contributing to the obesity occurring with age.  相似文献   

9.
Sought to determine the relationship between body fat and various components of gross motor proficiency. 10 tests of gross motor performance, previously shown by E. A. Fleishman (1964) to be reliable diagnostic indexes of 9 separate gross motor factors, were administered to 56 students in the US Naval School of Diving and Salvage. Six anthropometric indicators of body fat were also obtained from each S. Factor analyses confirmed the structure of the measures of physical proficiency and indicated the presence of a single dimension for body fatness. Tests of the relationships between body fatness and the components of physical proficiency revealed a selective effect where body fatness was significantly related to performance on only 3 of the 9 component measures: dynamic strength, gross body coordination, and stamina. Controlling for S age reduced the magnitude of the correlations by a slight degree but did not otherwise alter the relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

10.
RENAL DAMAGE CAUSED BY HYPERTENSION: Renal vasoconstriction seems to be a key factor in the origin of arterial hypertension and accounts for the decrease in renal blood flow commonly observed in patients with hypertension. An inverse correlation has been found between renal blood flow and clinic blood pressure levels in established hypertension. Other features of renal damage attributable to high blood pressure have also been correlated with clinic blood pressure levels. Microalbuminuria is a good example of an alteration in renal function that depends in part on blood pressure levels. EFFECTS OF ANTIHYPERTENSIVE AGENTS: Antihypertensive agents can prevent or ameliorate renal vascular damage secondary to arterial hypertension, including renal failure. Ambulatory blood pressure monitoring is an excellent method of studying blood pressure levels in relation to end-organ damage and the blood pressure response to antihypertensive agents. Preliminary studies using this technique indicate that changes in renal function are closely correlated with the average daily blood pressure in arterial hypertension. CONCLUSIONS: Further studies are needed on the mechanisms of renal deterioration and on how to preserve renal function in arterial hypertension.  相似文献   

11.
目的探讨血液流变学指标异常对不孕症的影响.方法对治疗组48例不孕症患者治疗前、治疗后分别进行血液流变学指标检测,并与对照组20例健康育龄女性的血液流变学指标进行比较.结果治疗组治疗前与对照组比较全血黏度高切、中切、低切均增高(P<0.01),红细胞压积增高(P<0.05),血浆黏度、红细胞沉降率与对照组比较无明显差异(P>0.05).经活血理气中医治疗后治疗组治疗后较治疗前比较全血黏度高切、中切、低切均下降(P<0.05),红细胞压积下降(P<0.05).治疗组治疗后血流变学指标与对照组比较,无显著性差异(P>0.05).结论血液黏稠度增高导致的气滞血瘀证可能是引起不孕的原因之一,通过活血理气治疗,改善微循环,增加局部组织器官血液灌注,对受孕有积极意义.  相似文献   

12.
The muramic lactam content of spores of Bacillus sphaericus mutants defective in meso-diaminopimelic acid synthesis increases almost linearly with an increase of meso-diaminopimelic acid concentration in the medium. Since muramic lactam content is a measure of cortex content, the amount of cortex in spores of the mutants can be easily varied by changing the meso-diaminopimelic acid concentration in the medium. Characteristic properties were tested in spores containing different amounts of cortex. Critical amounts of cortex were associated with different spore properties. Refractility and dipicolinic acid accumulation in the spores both required about 20% of the maximum cortex content (although refractility is independent of dipicolinic acid content). For xylene octanol resistance, about 25% of the maximum cortex content was required.  相似文献   

13.
14.
15.
Post-milking measurements of teat skin chapping score, teat thickness and colonization by Staphylococcus aureus were determined for 11.5 d. Three teats on each of twelve Holstein cows, free from Staph. aureus intramammary infections, were immersed in 1 M-NaOH solution to induce teat chapping; the fourth teat served as a control. To achieve different degrees of chapping, one teat per cow received one immersion after each milking for three consecutive milking periods, a second teat received two immersions, and the third teat received one immersion which coincided with the last immersion of the other two teats. All teats were challenged twice with a skim milk broth culture of Staph. aureus (5 x 10(6) cfu) after the first and second milking following NaOH treatment. Measures were initiated with the milking following the last Staph. aureus challenges. Tissue thickness of the lateral side of the teat (barrel) and colonization by Staph. aureus declined with time. Thickness of the teat end varied more erratically. Teat skin chapping score was positively correlated (P < 0.001) with tissue thickness of the barrel and Staph. aureus colonization. Thickness of the barrel was not significantly correlated with Staph. aureus colonization. Barrel thickness as a covariate had a significant effect (P < 0.05) on teat skin colonization of Staph. aureus, whereas teat skin score and teat end thickness had no significant effect. Thus, thickness of the lateral side of the teat explained the greatest variation in Staph. aureus teat skin colonization in the model tested.  相似文献   

16.
BACKGROUND: Histamine, a product of mast cells, is an effective vasoconstrictor of atherosclerotic coronary arteries. Because it has been suggested that coronary spasm plays a role in acute coronary syndromes such as myocardial infarction (MI), we quantified and characterized the mast cells in the adventitia of infarct-related coronary arteries. METHODS AND RESULTS: In a series of 17 autopsied MI patients, we identified the segment of the left coronary artery with ruptured plaque responsible for the infarction. More distal segments from the infarct-related coronary artery, either with nonruptured plaques or with normal intima, were also studied. Corresponding segments taken from left coronary arteries obtained from 17 patients who had died of noncardiac causes served as controls. Adventitial mast cells in the infarct-related and the control coronary arteries were identified immunohistochemically by staining for tryptase. In the infarct-related coronary arteries, we also stained for chymase and histamine. Moreover, T lymphocytes and macrophages were identified immunohistochemically and counted. In the infarct-related coronary arteries, significantly larger numbers of mast cells were present in the adventitia backing ruptured plaques (98+/-40 mast cells/mm2, mean+/-SD) than in the adventitia backing nonruptured plaques (41+/-12 mast cells/mm2; P<0.001) or backing normal intima (19+/-8 mast cells/mm2; P<0.001). No such difference was found among the 3 different segments in the control coronary arteries. The majority of mast cells contained not only tryptase but also chymase. Mast cells were the only cells in the coronary adventitia that contained histamine. The proportion of adventitial mast cells that were degranulated was highest in the segments with ruptured plaques. The numbers of adventitial macrophages and T lymphocytes were also increased in the segments with plaque rupture. CONCLUSIONS: In infarct-related coronary arteries, the number of degranulated mast cells in the adventitia backing ruptured plaques is increased. Histamine released from the degranulated mast cells may reach the media, where it may locally provoke coronary spasm and thus contribute to the onset of MI.  相似文献   

17.
Isolation of the rat pup from the nest and dam for one hour per day from PN 2-9 is a useful paradigm for producing stress in the neonate. These previously isolated rats respond to an amphetamine challenge with alterations in activity at the juvenile stage or as adults. Furthermore, when dopamine release is measured in the nucleus accumbens, juveniles release 3 times more dopamine after amphetamine than do controls. This study describes changes in behavior and brain dopamine systems at PN 10. Experiment 1 determined an appropriate amphetamine dose that could be used for behavioral activation at PN 10. Experiment 2 produced significant evidence of enhanced behavioral activation after the isolation paradigm and indicated that brain regions innervated by the mesolimbic dopamine system, septum, and hypothalamus display increased dopamine turnover and that the nigrostriatal pathway is less active. Likewise, in Experiment 3, in vivo microdialysis of the nucleus accumbens indicated that previously isolated pups respond to an amphetamine challenge with a several-fold increase in dopamine release over a 4-hour session.  相似文献   

18.
To investigate the relationship between polymorphisms of the angiotensin-converting enzyme (ACE) and the angiotensin II type 1 receptor (AT1R) genes and structural phenotypes of arteries, we studied a cohort of 340 subjects (aged 49+/-12 years) without evidence of cardiovascular disease and who had never been treated previously with any cardiovascular treatments. Structural phenotypes (wall thickness and internal diameter) were evaluated for the common carotid and the radial arteries using high-resolution echo-tracking devices (NIUS-02 and Wall Track System). The influence of ACE insertion/deletion (I/D) and AT1R A/C1166 polymorphism genotypes on structural parameters was tested by ANOVA and logistic regression analysis. For the radial artery, mean wall thickness among subjects according to the ACE I/D or AT1R A/C1166 genotypes was not different. This lack of association persisted in a logistic regression analysis or when the comparison was restricted to a subgroup of subjects potentially at high genetic risk (DD and CC or AC) compared with subjects at low genetic risk (AA and II or ID). Also, no association was observed between the carotid artery intima-media thickness and the 2 polymorphisms. In conclusion, the ACE I/D and the AT1R A/C1166 gene polymorphisms are not markers of vascular hypertrophy in subjects with no evidence of cardiovascular disease. These results suggest that these gene polymorphisms have an undetectable role in the geometry of the radial and carotid arteries compared with usual determinants such as blood pressure and age.  相似文献   

19.
Experiments are conducted to determine how the calculation of the parameters of cold pipe rolling, taking primary account of the metal propagation, affects the variation in pipe wall thickness.  相似文献   

20.
OBJECTIVE: To investigate the relationship between body mass index (BMI) and transvaginal ultrasonographic endometrial thickness. MATERIALS AND METHODS: Two hundred and twelve postmenopausal Japanese women (mean age, 62.1+/-8.0 years; range 47-85) with histologically proven normal endometrium and with endometrial thickness more than 1.0 mm were studied. Baseline characteristics including age, years since menopause, and BMI were recorded for each subject. The relationship between sonographic endometrial thickness and baseline characteristics was assessed in each subject. RESULTS: BMI was significantly correlated with endometrial thickness (r=0.40, p<0.001), but age and years since menopause were not correlated. On stepwise regression analysis only BMI was still associated with endometrial thickness (R2=0.16, p<0.001). CONCLUSION: Sonographic endometrial thickness differs with BMI in postmenopausal women. Higher BMI is associated with greater endometrial thickness.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号