Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evaluation of left ventricular performance in aortic stenosis, aortic regurgitation and mitral regurgitation from the stroke work/left ventricular mass ratio. Europ. J. Cardiol., 10/4, 279--294. 132 patients with a pure valvular dysfunction affecting a single orifice, namely aortic stenosis, aortic or mitral regurgitation, were studied. All patients, including 20 control subjects, underwent hemodynamic examination of both right and left heart chambers including left cineangiography. Using the stroke work index/myocardial mass ratio (SWI/MLV), for which the limits in normal subjects are narrow (0.81 +/- 0.03 . g-1) it was possible to divide these patients into three groups: Group I (SWI/MLV greater than 0.87 gm . g-1) characterized by a proportionately greater increase in stroke work index than myocardial mass (hyperfunctioning ventricle). Group II (0.87 gm . g-1 greater than or equal to SWI/MLV greater than or equal to 0.75 gm . g-1) characterized by a parallel increase in stroke work index and myocardial mass (normally functioning ventricle). Group III (SWI/MLV less than 0.75 gm . g-1) for which the increase in myocardial mass was proportionately greater than that of the stroke work index (hypofunctioning ventricle). As one progresses from group I to III, there is a concomitant fall in ventricular function with decreased mean velocity of circumferential fiber shortening (VCF), ejection fraction (EF) and increased enddiastolic volume (EDV) together with the hypertrophy of the left ventricle during the last stage. We conclude that the SWI/MLV ratio is an easy to calculate index, independent of the unerlying dysfunction, which evaluates left ventricular function by taking into account the myocardial mass.
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PMID:Evaluation of left ventricular performance in aortic stenosis, aortic regurgitation and mitral regurgitation from the stroke work/left ventricular mass ratio. 15 81

Scintillation angiocardiography was performed around the point of time when the injected RI mainly passed through the left ventricle. Gating permitted the radiophotography of the end-diastolic and end-systolic image of the left ventricle. Critiques of the techniques gave result that the best available image could be obtained when the cumulative count was 20,000, aperture setting 4/5 and brightness of cathode ray tube 8. Studies with mechanical model showed that the condition of high-flow, combined with the use of relatively small dose of RI resulted in a marked underetimation of the left ventricular image. Clinical studies was performed using SWI-LVEDV plots, giving the plot of stroke index (SWI) against the left ventricular end-diastolic volume (LVEDV). It was thus formed that the patients with enlarged left ventricles responded to the administration of digitalis with shrinkage of the heart, while the patients with relatively small heart responded to it with increase in SWI at the unchanged level of LVEDV. Studies with systolic time intervals particularly PEP/LVET, showed that relatively high values of PEP/LVET applied to those whose left ventricular SWI-LVEDV plots were located low and to the right, while relatively low values of PEP/LVET applied to those patients whose SWI-LVEDV plots were located high and towards the left, indicating relatively good LV performance.
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PMID:Determination of the left ventricular volume by scinticamera --basic studies and clinical application--. 32 13

Sixteen patients with cardiogenic shock complicating acute myocardial infarction underwent serial hemodynamic studies during intra-aortic balloon counterpulsation (IABC) at an assist frequency of 1:1. Significant increase was noted during the first 12 hours of IABC in the systemic artery peak diastolic pressure (assisted), cardiac index, stroke index, and stroke work index. During the second 12 hours further significant improvement was noted in the latter three parameters and, in addition, the systemic artery systolic pressure increased significantly. The pulmonary wedge pressure fell as did the total systemic resistance (TSR) during the first 24 hours of IABC. Patients found to be balloon independent after reduction in balloon assist frequency demonstrated significantly greater increase in systemic artery peak diastolic pressure during the first 12 hours of IABC than did those patients found to be balloon dependent. Likewise, the improvement noted in CI, SI, and SWI during the second 12 hours of IABC was of greater magnitude in balloon-independent than in balloon-dependent patients. The data suggest late hemodynamic deterioration after 48 hours of IABC. It is concluded that IABC is effective in improving the deranged hemodynamics of cardiogenic shock. Maximum response is noted between 24 and 48 hours. It is suggested that patients who are balloon independent may be distinguished from those who are balloon dependent by the hemodynamic response within the first 24 hours of IABC.
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PMID:The hemodynamic response to intra-aortic balloon counterpulsation in patients with cardiogenic shock complicating acute myocardial infarction. 84 26

The hemodynamic effects of ibopamine (SB-7505), the orally active 3,4-diisobutyryl ester of N-methyldopamine, were studied in 12 patients with congestive heart failure (CHF) after acute dosing, after 20 days of maintenance therapy and after 20 days of drug discontinuation. Acute ibopamine administration increased at rest cardiac index (CI p less than 0.05) and stroke work index (SWI p less than 0.05), and reduced pulmonary capillary wedge pressure (PCWP), mean pulmonary arterial pressure (PAP), total systemic (SVR p less than 0.05) and pulmonary vascular resistance (PVR). These beneficial hemodynamic effects were maintained during supine bicycle exercise: CI and SWI increased more markedly (p less than 0.05) and PCWP increased at a lower extent (p less than 0.05) after ibopamine than on control conditions. PVR exhibited a more pronounced decrease (p less than 0.02), while SVR showed superimposable reductions before and after ibopamine. After chronic therapy with the drug, hemodynamics and left ventricular function again improved during exercise, while withdrawal of ibopamine resulted in hemodynamic deterioration. Heart rate and systemic arterial pressure did not change significantly after the drug. This study demonstrates that ibopamine is able to improve cardiac performance during exercise in CHF patients after both acute and chronic administration.
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PMID:Hemodynamic evaluation during exercise test after acute and chronic ibopamine treatment in patients with congestive heart failure. 370 52

Thyroid hormones influence cardiac performance directly and indirectly via changes in peripheral circulation. Little, however, is known about the effect on myocardial oxidative metabolism and its relation to cardiac function and geometry. Patients with a history of thyroidectomy for thyroid cancer present a unique model to investigate the cardiac effects of hypothyroidism. Ten patients without heart disease were investigated in the hypothyroid state and again 4-6 weeks later under euthyroid conditions. Myocardial oxidative metabolism was measured by positron emission tomography with [11C]acetate and the clearance constant k(mono). Cine magnetic resonance imaging was applied to determine left ventricular geometry. A stroke work index (SWI = stroke volume x systolic blood pressure/ventricular mass) was calculated. Then, to estimate myocardial efficiency, a work metabolic index [WMI = SWI x heart rate/k(mono)] was obtained. Compared to hormone replacement, systemic vascular resistance and left ventricular mass were significantly higher in hypothyroidism. Ejection fraction and SWI were significantly lower. Despite an additional reduction of k(mono), the WMI was significantly lower, too. In summary, cardiac oxygen consumption is reduced in hypothyroidism. This reduction is associated with increased peripheral resistance and reduced contractility. Estimates of cardiac work are more severely suppressed than those of oxidative metabolism, suggesting decreased efficiency. These findings may provide an explanation for development or worsening of heart failure in hypothyroid patients with preexisting heart disease.
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PMID:Effect of thyroid hormones on cardiac function, geometry, and oxidative metabolism assessed noninvasively by positron emission tomography and magnetic resonance imaging. 1084 59

1. Extracardiac constraint and sensitivity to arterial pressure may be critical factors that limit the functional reserves of the developing fetal heart in utero. We hypothesise that extracardiac constraint is the predominant factor that limits fetal stroke volume (SV). To test this hypothesis we studied six chronically instrumented fetal sheep to determine the relative roles that extracardiac constraint and arterial pressure play in determining left ventricular (LV) function. 2. Pregnant ewes (128-131 days gestation, term = 147 days) were anaesthetised (5 mg kg(-1) Propofol I.V., then 1.5 % halothane, 50 % O(2), balance N(2)O by inhalation) and instrumented using sterile surgical techniques to record LV end-diastolic pressure (P(lved)), aortic pressure (P(ao)), pericardial pressure (P(per)), and LV SV. 3. After a minimum of 72 h recovery, LV function was assessed by altering fetal blood volume to vary P(lved). Ventricular function curves were generated using two measures of ventricular function, SV and stroke work index (SWI = SV x P(ao)), and two measures of ventricular filling, P(lved) and LV end-diastolic transmural pressure (P(lved,tm) = P(lved) - P(per)). 4. Although decreasing P(lved) from the resting level decreased SV, increasing P(lved) from the resting level did not increase SV because the ventricular function curve plateaued. This plateau was not explained solely by an increase in aortic pressure, as the plateau remained present in the SWI versus P(lved) curve. When extracardiac constraint was accounted for (SV against P(lved,tm)), the plateau was largely eliminated (approximately 80 %). The remaining portion of the plateau (approximately 20 %) was eliminated when both extracardiac constraint and arterial pressure were accounted for (SWI versus P(lved,tm)). 5. Thus, the major limitation upon LV function in the near-term fetus results from extracardiac constraint limiting ventricular filling while, at the same time, a much smaller limitation arises from increasing arterial pressure.
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PMID:Left ventricular stroke volume in the fetal sheep is limited by extracardiac constraint and arterial pressure. 1150 72

Proteasomes are the main non-lysosomal, multicatalytic proteinase complexes involved in the degradation of most intracellular proteins and in numerous cell processes. Studies from isolated cell models indicate that agents that induce oxidative stress may also damage proteasomes. Similarly, continuous oxidative stress during cell aging may impair proteasome activity. In ischemia-reperfusion models of organ injury, proteasomes may be involved in several ways. First, proteasomes were found to be targets of ischemia-reperfusion injury of the brain and heart. Second, proteasome activity increased in liver models of ischemia-reperfusion. Third, proteasome inhibition prevented ischemia-reperfusion injury of the brain, heart and kidney. A major mechanism by which proteasome inhibitors may confer tissue protection is inactivation of transcription activator nuclear factor-kappaB resulting in a block of expression of cytokines and cell adhesion molecules during the reperfusion phase. Thus, proteasome inhibition represents a novel strategy for the treatment of pathologies such as stroke, infarction, and kidney failure.
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PMID:Emerging roles of proteasomes in ischemia-reperfusion injury of organs. 1508 63

The INK4b-ARF-INK4a locus encodes for two cyclin-dependent kinase inhibitors, p15(INK4b) and p16(INK4a) and a regulator of the p53 pathway, ARF. In addition ANRIL, a non-coding RNA, is also transcribed from the locus. ARF, p15(INK4b) and p16(INK4a) are well-established tumor suppressors which function is frequently disabled in human cancers. Recent studies showed that single nucleotide polymorphisms mapping in the vicinity of ANRIL are linked to a wide spectrum of conditions, including cardiovascular disease, ischemic stroke, type 2 diabetes, frailty and Alzheimer's disease. The INK4b-ARF-INK4a locus is regulated by Polycomb repressive complexes (PRCs), and its expression can be invoked by activating signals. Other epigenetic modifiers such as the histone demethylases JMJD3 and JHDM1B, the SWI/SNF chromatin remodeling complex and DNA methyltransferases regulate the locus interplaying with PRCs. In view of the intimate involvement of the INK4b-ARF-INK4a locus on disease, to understand its regulation is the first step for manipulate it to therapeutic benefit.
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PMID:Epigenetic regulation of the INK4b-ARF-INK4a locus: in sickness and in health. 2071 61

Using magnetic resonance imaging (MRI) protocols of T(2)-, T(2)*-, diffusion- and susceptibility-weighted imaging (T2WI, T2*WI, DWI, and SWI, respectively) with a 7T system, we tested the hypothesis that treatment of embolic stroke with erythropoietin (EPO) initiated at 24 hr and administered daily for 7 days after stroke onset has benefit in repairing ischemic cerebral tissue. Adult Wistar rats were subjected to embolic stroke by means of middle cerebral artery occlusion (MCAO) and were randomly assigned to a treatment (n = 11) or a control (n = 11) group. The treated group was given EPO intraperitoneally at a dose of 5,000 IU/kg daily for 7 days starting 24 hr after MCAO. Controls were given an equal volume of saline. MRI was performed at 24 hr and then weekly for 6 weeks. MRI and histological measurements were compared between groups. Serial T2WI demonstrated that expansion of the ipsilateral ventricle was significantly reduced in the EPO-treated rats. The volume ratio of ipsilateral parenchymal tissue relative to the contralateral hemisphere was significantly increased after EPO treatment compared with control animals, indicating that EPO significantly reduces atrophy of the ipsilateral hemisphere, although no significant differences in ischemic lesion volume were observed between the two groups. Angiogenesis and white matter remodeling were significantly increased and occurred earlier in EPO-treated animals than in the controls, as evident from T2*WI and diffusion anisotropy maps, respectively. These data indicate that EPO treatment initiated 24 hr poststroke promotes angiogenesis and axonal remodeling in the ischemic boundary, which may potentially reduce atrophy of the ipsilateral hemisphere.
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PMID:Cerebral tissue repair and atrophy after embolic stroke in rat: a magnetic resonance imaging study of erythropoietin therapy. 2072 71

To investigate the correlation between the SWI findings and prognosis of the cerebrovascular disorders. From July 2008 to July 2010, 299 ischemic stroke patients were found in our hospital. The gender ratio is as male and female being 157 to 142. The mean age of all patients is 65.4, mean female age is 69.1, and mean male age is 62.6. There were 86 patients who had satisfactory pre-and post-treatment of CT, MRI with SWI. 23 of these 86 patients had catheter cerebral angiography. 50 of these 86 patients had MR angiogram or CT angiogram. 13 of these 86 patients did not have angiogram. We have also collected 7 severe cardiac arrested and cessation of cerebral circulation and 2 patients with chronic venous hypertension. Among the 86 patients, 23 patients who had negative with deoxygenated vessel on SWI were with small infarction on DWI. Thirty-one patients had negative on initial CT head scan. CT finding did not accord with presence of hypointense vessel on SWI. Sixty-three patients had varied degree of abnormal hypointense vessels on SWI as deoxygenated vessels. The initial small foci on DWI may result with a larger infarction if there were with prominent hypointense vessels.
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PMID:Susceptibility weighted imaging and cerebrovascular disorders. 2405 79


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