Search results for "laser"
showing 10 items of 3161 documents
Nicotinamide exerts different acute effects on microcirculatory function and tissue oxygenation in rat tumors
1993
Abstract Purpose : Nicotinamide has been reported to preferentially radiosensitize tumor tissue, supposedly through a reduction in tumor hypoxia. This may occur as a result of nicotinamide-induced changes in tumor blood flow and therefore the present study was undertaken to evaluate the effect of nicotinamide on circulatory parameters in skeletal muscle and tumor tissue (subcutaneously-implanted DS-sarcomas) of the rat. Methods and Materials : Mean arterial blood pressure (measured in the common carotid artery using a pressure transducer) and red blood cell flux (as measured by laser Doppler flowmetry) were continuously monitored for 120 min following a single intraperitoneal application of…
No improvement in perfusion and oxygenation of experimental tumors upon application of vasodilator drugs
2001
The oxygen deficiency seen in solid tumors is predominantly caused by an insufficient O2 supply as a result of inadequate tumor perfusion. The aim of this study was to analyze whether a number of vasodilator drugs might be suitable to increase tumor perfusion and consequently improve the oxygenation status of experimental tumors. Rats with s.c. DS-sarcomas were treated with either Na+-nitroprusside (7-25 microg x min(-1) x kg(-1) BW) or nifedipine (10 microg x min(-1) x kg(-1) BW). Red blood cell (RBC) flux was assessed continuously using laser-Doppler flowmetry and mean tumor pO2 was measured polarographically using O2-sensitive catheter electrodes. Systemic application of the vasodilator …
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, …
Metabolic syndrome triggered by high-fructose diet favors choroidal neovascularization and impairs retinal light sensitivity in the rat
2014
Diabetic retinopathy and age-related macular degeneration are the leading causes of blindness in Western populations. Although it is a matter of controversy, large-scale population-based studies have reported increased prevalence of age-related macular degeneration in patients with diabetes or diabetic retinopathy. We hypothesized that metabolic syndrome, one of the major risk factors for type 2 diabetes, would represent a favorable environment for the development of choroidal neovascularization, the main complication of age-related macular degeneration. The fructose-fed rat was used as a model for metabolic syndrome in which choroidal neovascularization was induced by laser photocoagulatio…
Low-level laser therapy and anesthetic infiltration for orofacial pain in patients with fibromyalgia : a randomized clinical trial
2018
Background To compare the analgesic effect of anesthetic infiltration of lidocaine 2% and low-level laser therapy (LLLT) by GaAlAs into tender points of patients with orofacial pain and fibromyalgia (FM). Material and Methods A randomized clinical trial was performed with adults (N=66) that were allocated into two groups (1:1): Group A received LLLT irradiation by Diode Laser GaAlAs (780nm) with expositions twice a week during six weeks and Group B was treated with anesthetic infiltration of lidocaine 2% without vasoconstrictor once a week for four weeks. The pain assessment included the Visual Analogic Scale (VAS) and tenderness to palpation. Results No dropout and adverse effect was obser…
Identification of α-tubulin as an autoantigen recognized by sera from patients with neuropsychiatric systemic lupus erythematosus.
2011
In a previous study we found in 50% of patients with neuropsychiatric manifestations of systemic lupus erythematosus (NP-SLE) organ specific antibodies to 45-56 kD proteins in a 100,000 g supernatant (SN) from bovine brain mitochondria. Aim of the present study was to identify the corresponding target antigen. A 100,000 g SN from bovine brain mitochondria was applied to SDS-gel electrophoresis. A 50 kD band recognized by sera from patients with NP-SLE in the Western blot (WB) was excised from the gels and applied to mass spectrometry. The identified protein was expressed in Escherichia coli and retested against sera from eleven patients with NP-SLE (severe symptoms n=6, mild symptoms n=5), …
Local barrier dysfunction identified by confocal laser endomicroscopy predicts relapse in inflammatory bowel disease
2011
Objectives: Loss of intestinal barrier function plays an important role in the pathogenesis of inflammatory bowel disease (IBD). Shedding of intestinal epithelial cells is a potential cause of barrier loss during inflammation. The objectives of the study were (1) to determine whether cell shedding and barrier loss in humans can be detected by confocal endomicroscopy and (2) whether these parameters predict relapse of IBD. Methods: Confocal endomicroscopy was performed in IBD and control patients using intravenous fluorescein to determine the relationship between cell shedding and local barrier dysfunction. A grading system based on appearances at confocal endomicroscopy in humans was devise…
Microcirculatory alterations in a mongolian gerbil sinus-vein thrombosis model
2001
Summary Background and purpose. The pathophysiology of sinus-vein thrombosis (SVT) is still controversial in patients and experimental animals, the microcirculatory alterations in particular. This study was designed to develop a new sinus-vein thrombosis model and to further elucidate pathophysiological events such as the relationship between local and regional cerebral blood flow and haemoglobin oxygen saturation (HbSO2), changes of the microvasculature, leukocyte behaviour and brain tissue damage. Methods. In a first experimental series, animals were divided into two groups which resulted from different procedures of inducing SVT. In the SSS middle occlusion group (SMO group), SVT was ind…
Cerebral blood flow alterations in a rat model of cerebral sinus thrombosis.
1993
Outcome from sinus vein thrombosis is very variable, with symptoms from headache to coma. Experimental findings suggest that an involvement of cortical veins is necessary to affect the cerebral microcirculation. Laser Doppler flowmetry was used to investigate the regional and temporal changes in local cortical blood flow after experimental occlusion and thrombosis of the superior sagittal sinus and tributary cortical veins in rats. Thrombosis was induced by slow injection of kaolin-cephalin suspension after frontal and caudal ligation of the sagittal sinus in rats. Local cerebral blood flow was measured by laser Doppler flowmetry and correlated with parenchymal damage found 24 hours after i…
Sub-cellular tumor identification and markerless differentiation in the rat brain in vivo by multiphoton microscopy
2012
Objective/Background Aim of the current study was to localize and differentiate between tumor (glioma) and healthy tissue in rat brains on a cellular level. Near-infrared multiphoton microscopy takes advantage of the simultaneous absorption of two or more photons to analyze various materials such as cell and tissue components via the observation of endogenous fluorophores such as NAD(P)H, FAD, porphyrins, melanin, elastin, and collagen, with a very high resolution, without inducing the problems of photo-bleaching on out-of-focus areas. Methods In vitro and in vivo studies on healthy rat brains as well as C6 glioma cell line allografts have been performed. Near-infrared laser pulses (λ = 690…