Search results for "scanning"
showing 10 items of 1808 documents
Prostasome-like vesicles stimulate acrosome reaction of pig spermatozoa
2007
Abstract Background The presence of small membranous particles characterizes the male genital fluids of different mammalian species. The influence of semen vesicles, denominated prostasomes, on sperm functional properties has been well documented in humans, but their biological activity is scarcely known in other species. The present work investigated prostasome-like vesicles in pig semen for their ability to interact with spermatozoa and to affect acrosome reaction. Methods Prostasome-like vesicles have been isolated from pig seminal plasma by high-speed centrifugation and Sephadex G-200 gel chromatography. Morphology of purified vesicles has been checked by scanning electron microscopy wh…
Microvascular perfusion 1 week and 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging
2006
To characterise the evolution of myocardial perfusion during the first 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging (CMR) and determine its significance.Prospective cohort design.Single-centre study in a teaching hospital in Spain.40 patients with a first ST-elevation myocardial infarction, single-vessel disease and thrombolysis in myocardial infarction (TIMI) grade 3 flow (stent in 33 patients) underwent rest and low-dose dobutamine CMR 7 (SD 1) and 184 (SD 11) days after infarction. Microvascular perfusion was assessed at rest by visual assessment and quantitative analysis of first-pass perfusion CMR. Of the 640 segments, 290 segme…
[Myocardial echocardiography with intracoronary injection of contrast in post-infarction patients. Implications and comparison with angiography and m…
2004
We analyzed the safety and feasibility of myocardial echocardiography with intracoronary injection of contrast, its effect on left ventricular remodeling and systolic function, and its relationship with angiography and magnetic resonance imaging (MRI) for the evaluation of post-infarction coronary microcirculation.Thirty patients with a first ST-elevation myocardial infarction and a patent infarct-related artery were studied. Mean perfusion score of the infarcted area was analyzed with myocardial echocardiography. TIMI and Blush grades (angiography) were determined. Mean perfusion score (MRI-perfusion), end-diastolic volume index and ejection fraction were determined with MRI. At 6 months a…
Perfusion computed tomography of intracranial meningiomas: In vivo correlation of cerebral blood volume and vascular permeability
2015
Background A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Methods Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour w…
Robotic assisted prostatic surgery in the Trendelenburg position does not impair cerebral oxygenation measured using two different monitors: A clinic…
2014
Robotic assisted prostatic surgery is frequently used because of its reduced side-effects compared with conventional surgery. During surgery, an extreme Trendelenburg position and CO2 pneumoperitoneum are necessary, which may lead to cerebral oedema, can potentially reduce brain perfusion and therefore could impair cerebral oxygenation. Cerebral oxygen saturation can be measured non-invasively using near-infrared spectroscopy (NIRS).The hypothesis of the present study was that steep Trendelenburg positioning during robotic assisted prostatic surgery impairs cerebral oxygen saturation measured using two different NIRS monitors.Clinical observational study.Primary care university hospital, st…
Additional diagnostic value of systolic dysfunction induced by dipyridamole stress cardiac magnetic resonance used in detecting coronary artery disea…
2009
Dipyridamole stress perfusion cardiovascular magnetic resonance (CMR) is used to detect coronary artery disease (CAD). However, few data are available on the diagnostic value of the systolic dysfunction induced by dipyridamole. This study investigated whether the induction of systolic dysfunction supplements the diagnostic information provided by perfusion imaging in the detection of CAD.Overall, 166 patients underwent dipyridamole CMR and quantitative coronary angiography, with CAD being defined as a stenosisor =70%. Systolic dysfunction at rest, systolic dysfunction with dipyridamole, induced systolic dysfunction, and stress first-pass perfussion deficit (PD) and delayed enhancement were …
Abnormal Myocardial Perfusion After Infarction in Patients With Persistent TIMI Grade-3 Flow. Only an Acute Phenomenon?
2007
Introduction and objectives It has been suggested that abnormal perfusion as derived from cardiovascular magnetic resonance imaging (CMR) is a transient dysfunction of microcirculation after myocardial infarction (MI) with TIMI 3 flow. We hypothesized that defects of myocardial perfusion may persist during the following months. Methods Forty-seven patients with MI and sustained TIMI 3 flow underwent intracoronary myocardial contrast echocardiography (MCE) 1 week and 6 months after infarction. Abnormal perfusion by MCE was regarded as >1 hypoperfused segment. Results At one week, 20 patients showed abnormal perfusion as derived from MCE. At six months 10 patients displayed chronic abnormal p…
Impaired Cerebrovascular Autoregulation in Large Vessel Occlusive Stroke after Successful Mechanical Thrombectomy: A Prospective Cohort Study
2020
Abstract Introduction: Successful thrombectomy improves morbidity and mortality after stroke. The present prospective, observational cohort study investigated a potential correlation between the successful restoration of tissue perfusion by mechanical thrombectomy and intact cerebrovascular autoregulation (CA). Objective: Status of CA in patients with large vessel occlusive stroke after thrombectomy. Methods: After thrombectomy CA was measured using transcranial Doppler ultrasound. For this purpose a moving correlation index (Mxa) based on spontaneous arterial blood pressure fluctuations and corresponding cerebral blood flow velocity changes was calculated. CA impairment was defined by Mxa …
Blood-brain barrier disruption by low-frequency ultrasound.
2006
Background and Purpose— A recent study showed a dramatic increase in cerebral hemorrhage comprising atypical locations with low-frequency ultrasound–mediated recombinant tissue plasminogen activator–thrombolysis in humans. Here, we provide a possible explanation for this phenomenon by a side effect observed in a study using the similar ultrasound device. Methods— The study was originally undertaken to investigate by transcranial Doppler sonography, positron emission tomography and perfusion MRI whether transcranial application of wide-field low-frequency ultrasound (300 kHz) improves cerebral hemodynamics in patients with cerebral small vessel disease. Results— Showing no clear positive ef…
Echinostoma caproni: Differential tegumental responses to growth in compatible and less compatible hosts
2010
Abstract The topography of the tegument of Echinostoma caproni adults collected from high (mice) and low (rats) compatible hosts was compared by SEM. In the oral (OS) and the ventral sucker (VS) areas, a worm age–host species interaction was found with regard to the density of spines. There was a decrease in the density of spines in the adults collected from mice, whereas an increase occurred in the OS area in worms from rats over time. The tegumentary spines in adults from mice became larger and blunter. Some spines from the VS area in adults from mice at 4 wpi were multipointed. The spines of adults from rats were sharper, not covered by the tegument and no multipointed spines were observ…