Search results for "models"
showing 10 items of 8211 documents
Neurological impairment in experimental antiphospholipid syndrome is associated with increased ligand binding to hippocampal and cortical serotonergi…
2013
The antiphospholipid syndrome (APS) is an autoimmune disease where the presence of high titers of circulating autoantibodies causes thrombosis with consecutive infarcts. In experimental APS (eAPS), a mouse model of APS, behavioral abnormalities develop in the absence of vessel occlusion or infarcts. Using brain hemispheres of control and eAPS mice with documented neurological and cognitive deficits, we checked for lymphocytic infiltration, activation of glia and macrophages, as well as alterations of ligand binding densities of various neurotransmitter receptors to unravel the molecular basis of this abnormal behavior. Lymphocytic infiltrates were immunohistochemically characterized using a…
The Presence of Gestational Diabetes is Associated with Increased Detection of Anti-HLA-class II Antibodies in the Maternal Circulation
2006
Problem Gestational diabetes (GD) may be associated with temporarily reduced immune tolerance toward alloantigens for the time of pregnancy. The aim of this study was to assess anti-HLA-class I and -II antibodies as markers for an aberrant immunostimulation in women with GD. Method of study The percentage of anti-HLA-class I and -II antibodies was estimated in women with GD, normal term delivery and fetal distress, which was confirmed by demonstrating low cord blood pH for this patient group. These antibodies may cross the placental barrier and cause interleukin-6 (IL-6) release from fetal monocytes by cross-linking monocytes with antibody-loaded cells. Therefore we estimated the percentage…
Information transfer and information modification to identify the structure of cardiovascular and cardiorespiratory networks
2017
To fully elucidate the complex physiological mechanisms underlying the short-term autonomic regulation of heart period (H), systolic and diastolic arterial pressure (S, D) and respiratory (R) variability, the joint dynamics of these variables need to be explored using multivariate time series analysis. This study proposes the utilization of information-theoretic measures to measure causal interactions between nodes of the cardiovascular/cardiorespiratory network and to assess the nature (synergistic or redundant) of these directed interactions. Indexes of information transfer and information modification are extracted from the H, S, D and R series measured from healthy subjects in a resting…
Heritability of corneal refraction and corneal astigmatism: a population-based twin study among 66- to 79-year-old female twins.
2012
. Purpose: To examine the heritability of corneal refraction power (CR) and corneal astigmatism (AST) in older women. Methods: Corneal refraction and AST were measured by IOL master in 52 monozygotic (MZ) and 47 dizygotic (DZ) female twin pairs aged 66–79 years. The relative contribution of genetic and environmental factors to individual differences in CR was estimated by applying an independent pathway model to the twin data and AST by intraclass correlations (ICC). Results: For the right eye, mean CR was 44.58 dioptres (D) (standard deviation (SD) ±1.28) When comparing CR of the right and left eye between MZ and DZ, no significant difference was found. Mean AST was 0.77 D (SD ±0.44) wi…
Canal transportation caused by a new instrumentation technique and three standard techniques
1996
The ability of three different enlarging techniques (balanced force concept, step-back, and recapitulation) and a prototype system to maintain the original canal path during root canal preparation were compared, in vitro, with a theoretical ideally prepared root canal. Measurements were made at the concave and convex sides of the canal at four different levels (1, 4, 5, and 7 mm from apical, respectively). Simulated root canals embedded in clear casting resin and an enlarging computer-supported device were used for this study. The results showed that none of the enlarging techniques used in this study was able to prepare a canal ideally. The prototype system, at level 1, showed an ideal amo…
Intra-operative locally injected pharmacotherapy as a novel strategy for adhesion prophylaxis.
2012
Abstract Background Pharmacotherapy for peritoneal adhesion prophylaxis has been a focus for intensive research. Previous strategies included intravenous and intraperitoneal application of suitable pharmaceutical agents. However, success of these strategies in humans has been limited. Here we describe intra-operative local injection of pharmaceuticals as a novel strategy for adhesion prophylaxis. Methods N = 208 peritoneal lesions were created in 26 adult Wistar rats. In each animal, lesions on one flank were randomly chosen for treatment with locally injected prednisolone whereas the contralateral side was injected with normal saline. Half of the animals were randomly selected for early a…
A nonlinear biomechanical model for evaluation of cerebrospinal fluid shunt systems.
1994
In view of complications arising from physical properties of cerebrospinal fluid shunts, a biomechanical model of hydrocephalus was set up to study in vivo parameters that may influence their function. These include: intracranial pressure, compliance and pulses, intrathoracic, intra-abdominal, and subcutaneous pressures, and the effects of siphonage and repeated valve flushing. Each of these factors was studied separately upon shunt implantation in the model. Results of testing of a sample low-pressure valve with antisiphon device conformed with consumer information in regard to valve opening pressure and pressure flow measurements. No customer information, however, was supplied concerning …
An experimental study on magnetic esophageal compression anastomosis in piglets.
2019
Abstract Introduction Fashioning a patent, watertight anastomosis in patients with esophageal atresia is a challenging task in pediatric surgery, particularly when performed under tension. A reproducible suture-less alternative would decrease operative time. We evaluated magnetic esophageal compression anastomoses in a novel bypass-loop swine model. Methods Eight-week-old piglets underwent thoracotomy to mobilize the esophagus at the carina to create a U-shaped loop. Custom-made 8 mm diameter Neodymium Magnets were inserted into the esophagus proximal and distal to the loop, then mated side-to-side at the future anastomosis site. Pigs were observed for 8 (n = 4), 10 (n = 6), and 12 (n = 2) …
Initiation and progression of atherosclerosis – enzymatic or oxidative modification of low-density lipoprotein?
2006
AbstractAtherosclerosis is widely regarded as a chronic inflammatory disease that develops as a consequence of entrapment of low-density lipoprotein (LDL) in the arterial intima. Native LDL lacks inflammatory properties, so the lipoprotein must undergo biochemical alterations to become atherogenic. Among several other candidates, two different concepts of lipoprotein modification are propagated, the widespread oxidation hypothesis and the less common E-LDL hypothesis, which proposes that modification of LDL occurs through the action of ubiquitous hydrolytic enzymes (enzymatically modified LDL or E-LDL) rather than oxidation. By clearly distinguishing between the initiation and progression o…
Automatic detection of lung nodules in CT datasets based on stable 3D mass–spring models
2012
We propose a computer-aided detection (CAD) system which can detect small-sized (from 3 mm) pulmonary nodules in spiral CT scans. A pulmonary nodule is a small lesion in the lungs, round-shaped (parenchymal nodule) or worm-shaped (juxtapleural nodule). Both kinds of lesions have a radio-density greater than lung parenchyma, thus appearing white on the images. Lung nodules might indicate a lung cancer and their early stage detection arguably improves the patient survival rate. CT is considered to be the most accurate imaging modality for nodule detection. However, the large amount of data per examination makes the full analysis difficult, leading to omission of nodules by the radiologist. We…