Search results for "Circulation"
showing 10 items of 1137 documents
Role of M1, M3, and M5 muscarinic acetylcholine receptors in cholinergic dilation of small arteries studied with gene-targeted mice
2011
Acetylcholine regulates perfusion of numerous organs via changes in local blood flow involving muscarinic receptor-induced release of vasorelaxing agents from the endothelium. The purpose of the present study was to determine the role of M1, M3, and M5 muscarinic acetylcholine receptors in vasodilation of small arteries using gene-targeted mice deficient in either of the three receptor subtypes (M1R−/−, M3R−/−, or M5R−/− mice, respectively). Muscarinic receptor gene expression was determined in murine cutaneous, skeletal muscle, and renal interlobar arteries using real-time PCR. Moreover, respective arteries from M1R−/−, M3R−/−, M5R−/−, and wild-type mice were isolated, cannulated with mic…
A Scanning Technique to Measure Regional Cerebral Blood Flow and Oxyhemoglobin Level
2001
OBJECTIVE: The application of a laser scanning technique to measure regional cerebral blood flow (CBF) and tissue hemoglobin oxygenation (HbO 2 ) using the rat closed cranial window preparation is described. METHODS: Twenty-nine male Wistar rats were used to consecutively measure local CBF by laser Doppler flowmetry and tissue HbO 2 by a microspectrophotometric method at multiple corresponding cortical locations. The scanning technique used a computer-controlled micromanipulator. Data from three experimental models are presented: the whisker stimulation model, the ischemia-reperfusion model, and the sinus-vein thrombosis model. Sequential changes in local CBF and HbO 2 data before, during, …
A Model‐Based Workflow to Benchmark the Clinical Cholestasis Risk of Drugs
2021
We present a generic workflow combining physiology-based computational modeling and in vitro data to assess the clinical cholestatic risk of different drugs systematically. Changes in expression levels of genes involved in the enterohepatic circulation of bile acids were obtained from an in vitro assay mimicking 14 days of repeated drug administration for 10 marketed drugs. These changes in gene expression over time were contextualized in a physiology-based bile acid model of glycochenodeoxycholic acid. The simulated drug-induced response in bile acid concentrations was then scaled with the applied drug doses to calculate the cholestatic potential for each compound. A ranking of the cholest…
Rapid palatal expansion: the role of microcirculation
2015
Transverse palate modifications fall under expansive orthopedic therapy of the upper maxilla. The only practical approach to the problem on the transverse plane is that of performing the expansion of the maxillary arch through an opening of the median palatal suture. It is important to understand the changes of the vascular network in midpalatal suture following the starting of rapid maxillary expansion. It is critical to maintain the blood supply and circulation for the osteogenesis and bone remodeling after the expansion. The aim of this research was to evaluate the effects of rapid orthopedic expansion (REP) at the microcirculatory level through capillaroscopic examination. METHODS: Fift…
ASSOCIATION OF RENAL RESISTIVE INDEX WITH MARKERS OF EXTRARENAL VASCULAR CHANGES IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS
2016
Introduction: Recent data suggest that renal hemodynamic parameters obtained by duplex Doppler sonography, especially the intrarenal resistive index (RRI), may be associated with systemic vascular changes. However, limited and conflicting data exist about the relationship between aortic stiffness and RI in autoimmune diseases, like systemic lupus erythematosus (SLE). Aim: To evaluate the relationship between RRI and arterial stiffness, assessed by aortic pulse wave velocity (aPWV), and between RRI and carotid atherosclerosis, evaluated by intima-media thickness (IMT) measurement in patients with SLE. Methods: In this cross-sectional study, we enrolled 39 SLE subjects (mean age 39 years) tha…
Extracorporeal Shock Wave Stimulates Angiogenesis and Collagen Production in Facial Soft Tissue.
2019
Abstract Background This study investigated the efficacy of extracorporeal shock wave (ESW) application in stimulating dermal thickness, vascularity, and collagen synthesis of facial skin in a large animal model. Materials and methods The facial skin of the maxillary and mandibular areas of goats (n = 6 per group) was treated with ESWs of different intensities (0.15 and 0.45 mJ/mm2; 1000 pulses). After 4 d, histology and immunohistochemistry were used to evaluate the following: dermal thickness, total number and abundance of microvessels, amount of type 1 collagen, and α-smooth muscle actin expression. Results Dermal thickness, number and abundance of microvessels, and collagen synthesis in…
Immune escape mechanism: defective resting and stimulated leukocyte-endothelium interaction in hepatocellular carcinoma of the rat.
2004
Hepatocellular carcinoma represents an increasing therapeutic challenge due to its high incidence and early metastasis. Numerous studies have demonstrated the influence of the vascular system on tumor growth and development. In addition, the role of leukocyte-endothelium interaction in tumor vessels is of particular significance with regard to immunological tumor therapy. In this study we used an experimental in vivo animal model that allows a quantitative analysis on vessel morphology, microcirculation, and leukocyte-endothelium interaction. The vessel architecture in tumor tissue was found to be extremely heterogeneous, with a consecutively variable blood flow velocity. Following superfus…
Glutathione protects metastatic melanoma cells against oxidative stress in the murine hepatic microvasculature.
1998
Calcein-labeled B16 melanoma (B16M) cells were injected intraportally, and in vivo video microscopy was used to study the distribution and damage of cancer cells arrested in the liver microvasculature over a period of 4 hours. The contribution of glutathione (GSH)-dependent antioxidant machinery to the possible oxidative stress-resistance mechanism of B16M cell was determined by in vitro incubation with the selective inhibitor of GSH synthesis L-buthionine (S,R)-sulphoximine (BSO) before B16M cell injection in untreated and 0.5-mg/kg lipopolysaccharide (LPS)-treated mice. In addition, untreated and LPS-treated isolated syngeneic hepatic sinusoidal endothelial cells (HSE) were used to determ…
Prognostic indicators for squamous cell carcinoma of the oral cavity: a clinicopathologic correlation.
1997
Fifty-three patients with T1 squamous cell cancer of the floor of mouth and ventral surface of the tongue with a known clinical outcome were retrospectively analyzed and arbitrarily divided into "aggressive" and "nonaggressive" groups based on their clinical behavior. Various host and tumor factors were then evaluated in an attempt to determine whether the tumor behavior could have been predicted. The paraffin-embedded tumor specimens were evaluated for tumor differentiation, tumor thickness and tumor invasion, microvessel density, and p53 expression. In addition, a composite morphologic grading score was obtained by combining cell differentiation, nuclear polymorphism, mitosis activity, de…
Structural adaptations in the murine colon microcirculation associated with hapten-induced inflammation
2007
Objectives: Blood flowing across the vascular endothelium creates wall shear stress, dependent on flow velocity and vessel geometry, that tends to disrupt lymphocyte-endothelial cell adhesion. To identify structural adaptations during acute colitis that may facilitate transmigration, we investigated the microcirculation in a murine model of acute colitis. Methods: In trinitrobenzenesulfonic acid (TNBS)- induced acute colitis, the infiltrating cells and colonic microcirculation was investigated by cellular topographic mapping as well as corrosion casting and 3- dimensional (3D) scanning electron microscopy. Colonic blood velocimetry was performed using intravital microscopy. Results: Clinica…