Home About us Contact
|
Home About us Contact | ||
|
|
||
Morphologic Characteristics (morphologic + characteristic)
Selected AbstractsMorphologic Characteristics of the Left Atrial Appendage, Roof, and Septum: Implications for the Ablation of Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2006WANWARANG WONGCHAROEN M.D. Introduction: The left atrium (LA) ablation in different regions, including LA appendage (LAA), LA roof, and LA septum, has recently been proposed to improve the success rate of treating patients with atrial fibrillation (AF). The purpose of this study was to investigate the anatomy of LAA, LA roof, and LA septum, using computed tomography (CT). Methods and Results: Multidetector CT scan was used to depict the LA in 47 patients with drug-refractory paroxysmal AF (39 males, age = 50 ± 12 years) and 49 control subjects (34 males, age = 54 ± 11 years). The area of LAA orifice, neck, and the length of roof line were greater in AF group than in control subjects. Three types of LAA locations and two types of LAA ridges were observed. Higher incidence of inferior LAA was noted in AF patients. The different morphologies of LA roof were described. Roof pouches were revealed in 15% of AF and 14% of controls. Moreover, we found septal ridge in 32% of AF and 23% of controls. Conclusions: Considerable variations of LAA and LA roof morphologies were demonstrated. Peculiar structures, including roof pouches and septal ridges, were delineated by CT imaging. These findings were important for determining the strategy of AF ablation and avoiding the procedure-related complications. [source] Muscle Fiber Regeneration in Human Permanent Lower Motoneuron Denervation: Relevance to Safety and Effectiveness of FES-Training, Which Induces Muscle Recovery in SCI SubjectsARTIFICIAL ORGANS, Issue 3 2005Ugo Carraro Abstract:, Morphologic characteristics of the long-term denervated muscle in animals suggest that some original fibers are lost and some of those seen are the result of repeated cycles of fiber regeneration. Muscle biopsies from lower motoneuron denervated patients enrolled in the EU Project RISE show the characteristics of long-term denervation. They present a few atrophic or severely atrophic myofibers dispersed among adipocytes and connective tissue (denervated degenerated muscle, DDM). Monoclonal antibody for embryonic myosin shows that regenerative events are present from 1- to 37-years postspinal cord injury (SCI). After 2- to 10-years FES-training the muscle cryosections present mainly large round myofibers. In the FES-trained muscles the regenerative events are present, but at a lower rate than long-term denervated muscles (myofiber per mm2 of cryosection area: 0.8 ± 1.3 in FES vs. 2.3 ± 2.3 in DDM, mean ± SD, P = 0.011). In our opinion this is a sound additional evidence of effectiveness of the Kern's electrical stimulation protocol for FES of DDM. In any case, the overall results demonstrate that the FES-training is safe: at least it does not induce more myofiber damage/regeneration than denervation per se. [source] Neural connectivity in hand sensorimotor brain areas: An evaluation by evoked field morphologyHUMAN BRAIN MAPPING, Issue 2 2005Franca Tecchio Abstract The connectivity pattern of the neural network devoted to sensory processing depends on the timing of relay recruitment from receptors to cortical areas. The aim of the present work was to uncover and quantify the way the cortical relay recruitment is reflected in the shape of the brain-evoked responses. We recorded the magnetic somatosensory evoked fields (SEF) generated in 36 volunteers by separate bilateral electrical stimulation of median nerve, thumb, and little fingers. After defining an index that quantifies the shape similarity of two SEF traces, we studied the morphologic characteristics of the recorded SEFs within the 20-ms time window that followed the impulse arrival at the primary sensory cortex. Based on our similarity criterion, the shape of the SEFs obtained stimulating the median nerve was observed to be more similar to the one obtained from the thumb (same median nerve innervation) than to the one obtained from the little finger (ulnar nerve innervation). In addition, SEF shapes associated with different brain regions were more similar within an individual than between subjects. Because the SEF morphologic characteristics turned out to be quite diverse among subjects, we defined similarity levels that allowed us to identify three main classes of SEF shapes in normalcy. We show evidence that the morphology of the evoked response describes the anatomo-functional connectivity pattern in the primary sensory areas. Our findings suggest the possible existence of a thalamo-cortico-thalamic responsiveness loop related to the different classes. Hum Brain Mapp 24:99,108, 2005. © 2004 Wiley-Liss, Inc. [source] Routine intraoperative Doppler sonography in the evaluation of complications after living-related donor liver transplantationJOURNAL OF CLINICAL ULTRASOUND, Issue 9 2007Jin-Young Choi MD Abstract Purpose To determine whether quantitative and qualitative analysis of intraoperative Doppler sonography data are predictive of vascular complications after living-related donor liver transplantation. Methods Intraoperative sonograms of 81 transplanted livers (right lobe in 61 patients, left lobe in 20 patients) were analyzed for the presence of blood flow, resistance index, systolic acceleration time (SAT), peak systolic velocity, and morphologic characteristics of spectral waveform of the hepatic artery. Peak velocity and spectral waveforms of portal and hepatic veins were also analyzed. Intraoperative sonography results were compared with information obtained with multidetector-row CT (MDCT) angiography or conventional angiography. The time interval between operation and angiography ranged from 1 to 23 days (mean, 8.5 days). Results Hepatic artery stenosis (HAS) was identified in 20 patients via MDCT angiography, conventional angiography, or both. The Doppler parameters found helpful for predicting HAS were tardus-parvus pattern and delayed SAT. The sensitivity, specificity, and negative predictive value (NPV) were 60.0%, 73.7%, and 84.9%, respectively, for tardus-parvus pattern and 40.0%, 83.6%, and 80.9%, respectively, for delayed SAT. Peak velocities of the portal and hepatic veins were not reliable indicators of vascular complication. Loss of triphasity of the hepatic vein had a 98.4% NPV for venous obstruction. Conclusions Delayed SAT of the hepatic artery and loss of triphasity of the hepatic vein had a >80% for specificity for predicting vascular complications. Tardus-parvus pattern, delayed SAT of the hepatic artery, and loss of triphasity of the hepatic vein showed an acceptable NPV for identifying vascular complications. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007 [source] Human fetal cortical and striatal neural stem cells generate region-specific neurons in vitro and differentiate extensively to neurons after intrastriatal transplantation in neonatal ratsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2006Therése Kallur Abstract Human fetal brain is a potential source of neural stem cells (NSCs) for cell replacement therapy in neurodegenerative diseases. We explored whether NSCs isolated from cortex and striatum of human fetuses, aged 6,9 weeks post-conception, maintain their regional identity and differentiate into specific neuron types in culture and after intrastriatal transplantation in neonatal rats. We observed no differences between cortex- and striatum-derived NSCs expanded as neurospheres in proliferative capacity, growth rate, secondary sphere formation, and expression of neural markers. After 4 weeks of differentiation in vitro, cortical and striatal NSCs gave rise to similar numbers of GABAergic and VMAT2- and parvalbumin-containing neurons. However, whereas cortical NSCs produced higher number of glutamatergic and tyrosine hydroxylase- and calretinin-positive neurons, several-fold more neurons expressing the striatal projection neuron marker, DARPP-32, were observed in cultures of striatal NSCs. Human cortical and striatal NSCs survived and migrated equally well after transplantation. The two NSC types also generated similar numbers of mature NeuN-positive neurons, which were several-fold higher at 4 months as compared to at 1 month after grafting. At 4 months, the grafts contained cells with morphologic characteristics of neurons, astrocytes, and oligodendrocytes. Many of neurons were expressing parvalbumin. Our data show that NSCs derived from human fetal cortex and striatum exhibit region-specific differentiation in vitro, and survive, migrate, and form mature neurons to the same extent after intrastriatal transplantation in newborn rats. © 2006 Wiley-Liss, Inc. [source] Induction of umbilical cord blood,derived ,2m,c-Met+ cells into hepatocyte-like cells by coculture with CFSC/HGF cellsLIVER TRANSPLANTATION, Issue 6 2005Yunfang Wang Several studies have indicated that adult stem cells derived from bone marrow (BM) and cord blood (CB) can differentiate into hepatocyte-like cells. This ability is important for the treatment of hepatic diseases with BM or CB as a potential approach. However, methods are still being developed for the efficient induction of stem cell differentiation and expansion to get enough cells to be useful. In the present study, we enriched a subset of umbilical cord blood ,2m,c-Met+ cells (UCBCCs) and investigated the combination effect of liver nonparenchymal cells (cirrhotic fat-storing cells [CFSCs]) and hepatocyte growth factor (HGF) on the induction of UCBCCs into hepatocyte-like cells. UCBCCs were cocultured with CFSC/HGF feeder layers either directly or separately using insert wells. Flow cytometric analysis showed that most UCBCCs were CD34+/,CD90+/,CD49f+CD29+Alb+AFP+. After cocultured with transgenic feeder layers for 7 days, UCBCCs displayed some morphologic characteristics of hepatocytes. Reverse-transcription polymerase chain reaction (RT-PCR) and immunofluorescence cell staining proved that the induced UCBCCs expressed several hepatocyte specific genes including AFP, Alb, CYP1B1 and cytokeratins CK18 and CK19. Furthermore, the induced cells displayed liver specific functions of indocyanine green (ICG) uptake, ammonium metabolism and albumin secretion. Hence, our data have demonstrated that UCBCCs might represent a novel subpopulation of CB-derived stem/progenitor cells capable of successful differentiation into hepatocyte-like cells when incubated with CFSC/HGF cells. In conclusion, not only HGF but also CFSCs and/or the secreted extracellular matrix (ECM) have been shown to be able to serve as essential microenvironment for hepatocyte differentiation. (Liver Transpl 2005;11:635,643.) [source] Visualisation of reverse pupillary block using AC-OCT in primary pigment dispersion syndromeACTA OPHTHALMOLOGICA, Issue 2007R LAEMMER Purpose: To describe morphologic characteristics associated with secondary IOP elevation due to pigment release after pupil dilation in primary melanin dispersion syndrome. Methods: The history of a 49 year old male patient with primary pigment dispersion syndrome and secondary ocular hypertension is described. Besides detailed ophthalmologic examination including slit lamp biomicroscopy, gonioscopy as well as IOP and Laser-Flare measurement (KOWA FC-1000; Kowa, Tokyo, Japan) before and after pupil dilation, anterior segment optical coherence tomography was performed before and after Nd:YAG laser iridotomy and in medical miosis. Results: After pupil dilatation IOP increased up to 46 mmHg at the right eye but no IOP elevation was recognised at the left eye. Measurement by Laser-Flare Cell Meter revealed no cells in undilated state but 13.4 cells/ 0.075 ,l at the right and 4.0 cells/ 0.075 ,l at the left eye after mydriasis. Nd:YAG laser iridotomy was recommended for the right eye to the patient recently. Iris configuration detected by OCT demonstrates a concave shape before iridotomy more pronounced temporal than nasal which resolves after application of pilocarpin as well as after performance of Nd:YAG laser iridotomy. Conclusions: The effect of Nd:YAG laser iridotomy as a prophylactic but potentially causal treatment in pigmentary glaucoma can be easily visualized by OCT as a fast and non-contact procedure. [source] Frequency of atrial septal aneurysm in patients with recent stroke: Preliminary results from a multicenter studyCLINICAL CARDIOLOGY, Issue 4 2001Michele Aquilina M.D. Abstract Background: The role of atrial septal aneurysm (ASA) as a risk factor for cerebral ischemia of unknown etiology is controversial. Recent studies have found an association between ASA and focal ischemic events, while results from other studies suggest a low incidence of embolism in patients with ASA. Hypothesis: The present study was designed to evaluate the frequency of ASA, a minor cardioembolic source, in patients with a recent stroke presenting with normal carotid arteries. Methods: In all, 394 patients with cerebral ischemic stroke were referred to our institutions. Patients underwent transthracic and transesophageal echocardiography and carotid artery ultrasound examination. The study population included 215 patients without significant arterial disease. Frequency and morphologic characteristics of ASA were evaluated. Results: Transthoracic examination showed ASA in 39 patients (18%), while transesophageal echocardiography showed ASA in 61 patients (28%). A patent foramen ovale was found in 47 patients (21.8%) and was associated with ASA in 40 patients (65.5%). We observed an increased thickness of the aneurysmatic wall (3.80 ± 1.7 mm) in all patients with ASA. Conclusions: The present study confirms the relationship between ASA and stroke in patients with normal carotid arteries. The most common abnormality associated with ASA was patent foramen ovale. We suggest that patients who have a stroke in the absence of significant carotid disease undergo transesophageal echocardiography to identify possible underlying septal abnormalities. [source] | |||||||||||||