Infarction (Total 419537 Papers Found)

BACKGROUND AND PURPOSE Continuous arterial spin-labeled perfusion MRI (CASL-PI) uses electromagnetically labeled arterial blood water as a diffusible tracer to noninvasively measure cerebral blood flow (CBF). We hypothesized that CASL-PI could detect perfusion deficits and perfusion/diffusion mismatches and predict outcome in acute ischemic stroke. METHODS We studied 15 patients with acute ischemic stroke within 24 hours of symptom onset. With the use of a 6-minute imaging protocol, CASL-PI wa ...
Using high-resolution positron emission tomography and the oxygen 15 continuous inhalation method, we examined the changes in cerebral metabolic rate of oxygen, blood flow, blood volume, and oxygen extraction fraction as a function of age in 25 optimally healthy, unmedicated volunteers who ranged in age from 20 to 68 years. Subjects were strictly selected for absence of cerebrovascular risk factors, dementia, or mental disorders; they had neither biological nor clinical abnormalities, and no foc ...
BACKGROUND Drug-eluting coronary-artery stents have been shown to decrease restenosis and therefore the likelihood that additional procedures will be required after percutaneous coronary intervention (PCI). We evaluated the use of a drug-eluting stent in patients undergoing PCI for acute myocardial infarction with ST-segment elevation. METHODS We randomly assigned 619 patients presenting with an acute myocardial infarction with ST-segment elevation to receive either a paclitaxel-eluting stent ...
Elderly patients are more prone than younger patients to develop cerebral desaturation because of the reduced physiologic reserve that accompanies aging. To evaluate whether monitoring cerebral oxygen saturation (rSO(2)) minimizes intraoperative cerebral desaturation, we prospectively monitored rSO(2) in 122 elderly patients undergoing major abdominal surgery with general anesthesia. Patients were randomly allocated to an intervention group (the monitor was visible and rSO(2) was maintained at & ...
A sensitive method was developed for detecting stiffness changes in the left ventricle. Stress-strain relationships (cr—e) were obtained in the form do~/de = ko~ + c from published studies on eight normal canine hearts, five infarcted canine hearts, and seven isolated cat papillary muscles. Utilizing pressure-volume relationships, the elastic stiffness (dcr/de) and the stiffness constant (k) were also evaluated in patients with normal ventricles, inappropriate hypertrophy, and congestive cardi ...
OBJECTIVES This study was designed to compare contemporary surgical revascularization (coronary artery bypass graft surgery [CABG]) versus TAXUS Express (Boston Scientific, Natick, Massachusetts) paclitaxel-eluting stents (PES) in diabetic and nondiabetic patients with left main and/or 3-vessel disease. BACKGROUND Although the prevalence of diabetes mellitus is increasing, the optimal coronary revascularization strategy in diabetic patients with complex multivessel disease remains controversia ...
BACKGROUND Caffeine is the most widely consumed stimulant in the world, and individual differences in response to its stimulating effects may explain some of the variability in caffeine consumption within a population. OBJECTIVE We examined whether genetic variability in caffeine metabolism [cytochrome P450 1A2 (CYP1A2) -163A-->C] or the main target of caffeine action in the nervous system [adenosine A(2A) receptor (ADORA2A) 1083C-->T] is associated with habitual caffeine consumption. ...
1. Ischaemia was simulated in the isolated sheep cardiac Purkinje fibre and guinea-pig papillary muscle by immersing the preparations in paraffin oil. Ion-selective microelectrodes recorded potassium (Ks+) and pH (pHs) in the thin film of Tyrode solution trapped at the fibre surface while other microelectrodes recorded intracellular pH (pHi), membrane potential and action potentials (AP) (evoked by field stimulation), or membrane current (two-microelectrode voltage clamp in shortened Purkinje fi ...
In the setting of difficult dissection of Calot’s triangle during laparoscopic cholecystectomy, conversion is commonly advocated. An alternative approach aimed at preventing bile duct injury is laparoscopic partial cholecystectomy (LPC). The safety and efficacy of this procedure are unclear. A systematic review of the literature was performed independently by three researchers. The outcomes were conversion rate, hospital length of stay (LOS), bile duct injury, bile leak, symptomatic gallstones ...
Plasminogen activator inhibitor type-1 (PAI-1) is a major physiological inhibitor of fibrinolysis, with its plasma levels correlating with the risk for myocardial infarction and venous thrombosis. The regulation of PAI-1 transcription by endothelial cells (ECs), a major source of PAI-1, remains incompletely understood. Adipocytes also produce PAI-1, suggesting possible common regulatory pathways between adipocytes and ECs. Peroxisomal proliferator-activated receptor-gamma (PPAR)gamma is a ligand ...
OBJECTIVE To investigate the association between migraine and ischaemic or haemorrhagic stroke in young women. DESIGN Hospital based case-control study. SETTING Five European centres participating in the World Health Organisation Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. SUBJECTS 291 women aged 20-44 years with ischaemic, haemorrhagic, or unclassified arterial stroke compared with 736 age and hospital matched controls. INTERVENTION Questionnaire. ...
OBJECTIVES The aim of this study was to determine whether cardiac magnetic resonance (CMR) in vivo T1 mapping can measure myocardial area at risk (AAR) compared with microspheres or T2 mapping CMR. BACKGROUND If T2-weighted CMR is abnormal in the AAR due to edema related to myocardial ischemia, then T1-weighted CMR should also be able to detect and accurately quantify AAR. METHODS Dogs (n = 9) underwent a 2-h coronary occlusion followed by 4 h of reperfusion. CMR of the left ventricle was pe ...
Preamble It is becoming more apparent each day that despite a strong national commitment to excellence in health care, the resources and personnel are finite. It is, therefore, appropriate that the medical profession examine the impact of developing technology on the practice and cost of medical care. Such analysis, carefully conducted, could potentially have an impact on the cost of medical care without diminishing the effectiveness of that care. Therapeutic Cardiovascular Procedures with the f ...
BACKGROUND In a group of patients admitted for unstable angina, we investigated whether C-reactive protein (CRP) plasma levels remain elevated at discharge and whether persistent elevation is associated with recurrence of instability. METHODS AND RESULTS We measured plasma levels of CRP, serum amyloid A protein (SAA), fibrinogen, total cholesterol, and Helicobacter pylori and Chlamydia pneumoniae antibody titers in 53 patients admitted to our coronary care unit for Braunwald class IIIB unstabl ...
Sodium-glucose cotransporter-2 (SGLT2) inhibitors, including empagliflozin, dapagliflozin, and canagliflozin, are now widely approved antihyperglycemic therapies. Because of their unique glycosuric mechanism, SGLT2 inhibitors also reduce weight. Perhaps more important are the osmotic diuretic and natriuretic effects contributing to plasma volume contraction, and decreases in systolic and diastolic blood pressures by 4 to 6 and 1 to 2 mm Hg, respectively, which may underlie cardiovascular and k ...
BACKGROUND We, and others, have previously reported a strong correlation between increased inter-ventricular dispersion of repolarization and the occurrence of fatal arrhythmia in animal models of CHF. The existence of this and other such distinct electrophysiologic phenotypes in right (RV) vs. left ventricles (LV) could be explained by chamber-specific patterns of gene expression. METHODS We employed microarray gene profiling of 13824 sequence-verified, nonredundant rodent cDNAs to compare my ...
BACKGROUND Central nervous system primary malignant melanoma accounts for approximately 1% of all the cases of melanoma; reports in the literature are relatively rare. CASE DESCRIPTION A 74-year-old man was hospitalized because of an episode of aphasia. The neuroradiologic examinations demonstrated a round homogeneous lesion extending near the left sylvian fissure. He had no extracranial abnormalities. The patient underwent a neurosurgical procedure and the tumor was macroscopically totally ex ...
BACKGROUND & AIMS It is unclear whether patients with hepatic encephalopathy (HE) have disturbed brain oxygen metabolism and blood flow. METHODS We measured cerebral oxygen metabolism rate (CMRO(2)) by using (15)O-oxygen positron emission tomography (PET); and cerebral blood flow (CBF) by using (15)O-water PET in 6 patients with liver cirrhosis and an acute episode of overt HE, 6 cirrhotic patients without HE, and 7 healthy subjects. RESULTS Neither whole-brain CMRO(2) nor CBF differed signi ...
Most ischemic strokes are caused by an embolic or thrombotic occlusion of an intracranial artery. The immediate aims of acute stroke treatment are recanalization of the occluded artery and reperfusion of the ischemic brain region. Currently, intravenous thrombolysis that is administered within 4.5 hours after the onset of a stroke is the only proven treatment.1,2 However, recanalization rates within 24 hours after the administration of intravenous tissue plasminogen activator (t-PA) are low when ...
OBJECTIVE In acute type A dissection long-term results of conservative aortic root surgery were compared with the outcome of primary valve and/or root replacement. METHODS Between 1985 and 1995, 199 patients (mean age 59 years, 154 men) were operated on. The aortic root was involved in the dissection process and valve incompetence of varying degree was present without exception. Replacement of a proximal aortic segment was standard procedure in all patients. The aortic valve was preserved in 1 ...
Ischemic preconditioning renders the heart resistant to infarction by an unknown mechanism. This study tests whether preconditioning may be working through activation of ATP-sensitive potassium channels. If that were the case, then blockade of the channels should eliminate preconditioning's protection, and activation of these channels should mimic it. Thirty minutes of regional coronary ischemia followed by 3 hours of reperfusion caused 38.0 +/- 3.7% of the risk zone to become infarcted in contr ...
Training has been shown to induce cardioprotection. The mechanisms involved remain still poorly understood. Aims of the study were to examine the relevance of training intensity on myocardial protection against ischemia/reperfusion (I/R) injury, and to which extent the beneficial effects persist after training cessation in rats. Sprague-Dawley rats trained at either low (60% $$ {\dot{{V}}\text{O}}_{2\max } $$ ) or high (80% $$ {\dot{{V}}\text{O}}_{2\max } $$ ) intensity for 10 weeks. An additio ...
BACKGROUND AND PURPOSE Hyperfibrinogenemia is a known cardiovascular risk factor, but its role as a risk factor for ischemic stroke remains controversial. Most studies on this topic did not consider the different etiologies of ischemic stroke. We designed this study to compare plasma fibrinogen concentrations in patients with acute ischemic stroke due to large vessel disease (LVD) or small vessel disease (SVD). MATERIAL AND METHODS We studied 203 patients with acute ischemic stroke, including ...
Few haematological or lipid risk factors have been identified for stroke, by contrast with coronary heart disease. To find out whether a marker of endogenous fibrinolytic function might be associated with stroke risk, we measured tissue plasminogen activator (tPA) antigen concentrations in baseline plasma samples from 88 healthy participants in the Physicians' Health Study who subsequently had first-ever strokes (71 thromboembolic, 12 haemorrhagic, 5 indeterminate) and from 471 participants who ...
Animals transgenic (Tg) for reporter genes would be useful to following a given cell lineage during differentiation and regeneration processes. Here, we established a beta-galactosidase (lacZ) Tg rat to use as a tool for regenerative research. Strong lacZ expression was observed in the skeletal muscles, myocardium, pancreas, and skin obtained from these lacZ-Tg rats, and moderate lacZ expression was observed in the liver, spleen, kidney, and cartilage. In contrast, brain, vessels, lung, adrenal ...
The success of a primary percutaneous intervention (PCI) in the setting of ST elevation myocardial infarction depends on the functional and structural integrity of coronary microcirculation. Coronary microvascular dysfunction and obstruction (CMVO) occurs in up to half of patients submitted to apparently successful primary PCI and is associated to a much worse outcome. The current review summarizes the complex mechanisms responsible for CMVO, including pre-existing coronary microvascular dysfunc ...
A remarkable aspect of adult neurogenesis is that the tight regulation of subventricular zone (SVZ) neuroblast migration is altered after ischemic stroke and newborn neurons emigrate towards the injury. This phenomenon is an essential component of endogenous repair and also serves to illuminate normal mechanisms and rules that govern SVZ migration. Stroke causes inflammation that leads to cytokine and chemokine release, and SVZ neuroblasts that express their receptors are recruited. Metalloprote ...
Pregnant CD rats were treated subcutaneously with 0, 5 or 10 mg/kg/day of imipramine (IMI) on days 8-20 of gestation. Behavioral and neurochemical endpoints were measured at different postnatal days (PND). Three behavioral tests were conducted: negative geotaxis on PNDs 7-9; auditory startle habituation (ASH) on PNDs 14, 16 and 18; locomotor activity before and after intraperitoneal (i.p.) injection of saline or 0.5 mg/kg d-amphetamine on PND 21. Catecholamine levels, B-adrenergic and muscarinic ...
To define the sensitivity, specificity and predictive accuracy of two-dimensional echocardiographic detection of left ventricular thrombus, the echocardiograms of 78 patients who had independent proof of the presence or absence of a left ventricular thrombus were interpreted without knowledge of any clinical data. The presence of thrombus was established by autopsy in four patients, by aneurysmectomy in three, and by indium-111 platelet imaging in 15; the absence of thrombus was proved by autops ...
BACKGROUND Inherent limitations of conventional cytology often result in a failure to diagnose lymphomatous meningitis in cerebrospinal fluid (CSF) specimens from patients who actually have the disease. The development of polymerase chain reaction (PCR) techniques for the diagnosis of lymphoma based on the detection of clonal rearrangements of the immunoglobulin or T-cell receptor genes offers an alternative, DNA-based test for the diagnosis of lymphoma in the CSF. METHODS In this retrospectiv ...
BACKGROUND Factors related to socioeconomic status and health care quality and management may influence mortality and morbidity rates due to acute myocardial infarction (AMI). OBJECTIVE To compare mortality and morbidity in patients with AMI hospitalized in public and private hospitals. METHODS An observational study, with comparison groups. Clinical evaluation on admission, and recording of diagnostic, therapeutic and evolution data until discharge or death. Comparison of clinical character ...
Isoflurane mimics the cardioprotective effect of acute ischemic preconditioning with an acute memory phase. We determined whether isoflurane can induce delayed cardioprotection, the involvement of ATP-sensitive potassium (K(ATP)) channels, and cellular location of the channels. Neonatal New Zealand White rabbits at 7-10 days of age (n = 5-16/group) were exposed to 1% isoflurane-100% oxygen for 2 h. Hearts exposed 2 h to 100% oxygen served as untreated controls. Twenty-four hours later resistance ...