Search results for "Pressure"
showing 10 items of 4493 documents
Pathomechanism of Brain Oedema in Experimental Intracerebral Mass Haemorrhage
1988
The prognosis of intracerebral haemorrhage is extremely poor when arterial hypertension is present. We investigated elastance of the brain tissue and brain hydraulic conductivity in normotensive (MAP ~ 110 mmHg) and hypertensive (MAP ~ 170 mmHg/angiotensin infusion) cats following a stereotactically produced intracerebral haemorrhage. For 12 hours after the onset of haemorrhage we registered the course of ICP, subsequently the water content of cortex, white matter and basal ganglia as well as the interstitial concentration of serum proteins in the corresponding regions were determined (Evans-Blue, immunofluorescence). Hypertension was associated with a slight increase in ICP and tissue wate…
SELDI-TOF-MS ProteinChip array profiling of tears from patients with dry eye.
2005
Protein and peptides in tears play an important role in ocular surface diseases. In previous studies, changes have been demonstrated in the electrophoretic protein profiles of patients with dry eye. The purpose of this work was to determine the usefulness of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) ProteinChip Array (Ciphergen Biosystems, Inc., Fremont, CA) technology for the automated analysis of proteins and peptides in tear fluid.Patients with dry eye (DRY, n = 88) and healthy subjects (CTRL, n = 71) were examined. Their tear proteins were analyzed using SELDI-TOF-MS ProteinChip Arrays with three different chromatographic surfaces (CM10…
Use of photoplethysmography to determine gastrointestinal perfusion pressure: an experimental canine model.
2002
<i>Objectives:</i> To develop an experimental model to assess the parietal perfusion pressure (PPP) of the digestive tract using photoplethysmography. <i>Materials and Methods:</i> Twenty-two mongrel dogs were used. Progressive external compression was applied to the intestinal wall and the PPP was assessed with photoplethysmography. The study group was divided into two groups. In group 1 PPP was measured at the levels of the stomach, duodenum, jejunum and transverse colon. In group 2 PPP was measured after temporary occlusion of the truncal and marginal circulation of the jejunum to provide further variables. <i>Results:</i> The PPP decreased significant…
Remote estimation of blood pulse pressure via temporal tracking of reflected secondary speckles pattern
2011
We present a novel technique for remote noncontact blood pulse pressure measurement. It is based on tracking both temporal and amplitude changes of reflected secondary speckle produced in human skin when illuminated by a laser beam. The implemented technique extracts the difference between the systolic and the diastolic blood pressure. Experimental results are presented showing good agreement when compared with conventional measurement methods.
Structural heteropolysaccharides as air-tight sealants of the human pleura
2018
Pulmonary "air leaks," typically the result of pleural injury caused by lung surgery or chest trauma, result in the accumulation of air in the pleural space (pneumothorax). Air leaks are a major source of morbidity and prolonged hospitalization after pulmonary surgery. Previous work has demonstrated structural heteropolysaccharide (pectin) binding to the mouse pleural glycocalyx. The similar lectin-binding characteristics and ultrastructural features of the human and mouse pleural glycocalyx suggested the potential application of these polymers in humans. To investigate the utility of pectin-based polymers, we developed a simulacrum using freshly obtained human pleura. Pressure-decay leak t…
Clearance of Edema Fluid into Cerebrospinal Fluid
1983
The formation of cerebral edema appears to be the response of the brain to injury from a diversity of causes, in association with tumors, trauma, and infections, as well as toxic, anoxic, and metabolic disorders. The classification by Klatzo14 of cerebral edema into two major categories, vasogenic edema and cytotoxic edema, has clarified our understanding of this pathological problem. A third category has been termed interstitial 10 or hydrocephalic 17 edema. The various processes are not mutually exclusive. In ischemic brain edema, changes characteristic of vasogenic and cytotoxic cerebral edema occur, and in subarachnoid hemorrhage, all three types of edematous changes may develop. Nevert…
Visualization of alveolar recruitment in a porcine model of unilateral lung lavage using3He-MRI
2009
BACKGROUND: In the acute respiratory distress syndrome potentially recruitable lung volume is currently discussed. (3)He-magnetic resonance imaging ((3)He-MRI) offers the possibility to visualize alveolar recruitment directly. METHODS: With the approval of the state animal care committee, unilateral lung damage was induced in seven anesthetized pigs by saline lavage of the right lungs. The left lung served as an intraindividual control (healthy lung). Unilateral lung damage was confirmed by conventional proton MRI and spiral-CT scanning. The total aerated lung volume was determined both at a positive end-expiratory pressure (PEEP) of 0 and 10 mbar from three-dimensionally reconstructed (3)H…
Control of brain temperature during experimental global ischemia in rats.
1999
Temperature control during experimental ischemia continues to be of major interest. However, if exposure of brain tissue is necessary during the experiment, regional heat loss may occur even when the core temperature is maintained. Furthermore, valid non-invasive brain temperature monitoring is difficult in small rodents. This paper describes a method for both monitoring and maintenance of brain temperature during small animal preparations in a stereotaxic frame. The device used includes an ear-bar thermocouple probe and a small near-infrared radiator. The new equipment permitted to maintain peri-ischemic brain temperature at a desired level while carrying out non-invasive continuous record…
Interrelationship between mean arterial blood pressure, blood flow, and vascular resistance in solid tumor tissue of DS-carcinosarcoma
1975
In vivo-Untersuchungen der Tumordurchblutung an Implantationstumoren eines DS-Carcinosarkoms in der Rattenniere zeigen eine deutliche Abhangigkeit der Durchblutungsgrosse vom Tumorgewicht. Bei Variation des arteriellen Mitteldrucks zwischen 40 und 135 mm Hg steigt die Durchblutung der einzelnen Tumoren linear mit zunehmendem Perfusionsdruck an. Eine zunehmende Rarefizierung der terminalen Strombahn mit ansteigendem Tumorgewicht wird belegt durch eine starke Zunahme des Stromungswiderstandes, der schon bei sehr jungen Tumoren wesentlich hohere Werte als bei verschiedenen Organen aufweist.
Cerebral Oxygen Supply in Brain Edema and During Ventriculo-Cisternal Perfusion
1976
Numerous brain injuries and brain tumors lead to edema in brain tissue which can have consequences for the oxygen supply to the damaged tissue as well as to adjacent tissue areas. In studies made of the blood flow and oxygen supply in perifocal edematous tissue of brain tumors and lesions in patients undergoing various brain operations a direct relationship between the regional blood flow and the water content could be demonstrated (3). As the water content of the tissue increased, the blood flow through it diminished. In many cases, the reduction of the blood flow in the brain tissue induced an insufficient oxygen supply. In the tissue samples under investigation, the CrP and ATP concentra…