Search results for "Perfusion"

Flow and Pressure during Liver Preservation under ex situ and in situ Perfusion with University of Wisconsin Solution and Histidine-Tryptophan-Ketogl…

2006

Effective preservation of liver grafts is the first essential step for successful liver transplantation. Insufficient perfusion leads to ischemic-type biliary lesions after transplantation. Perfusion of the graft can be performed either in situ or ex situ, with gravity flow or pressure-controlled. Mainly University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions are used widespread in clinical liver transplantation. Due to a persistent lack of data, we performed this systematic investigation of in situ and ex situ perfusion of liver grafts with HTK (low-viscous) and UW (high-viscous) solutions at different pressure steps on the perfusion solution (gravity flow, 50, …

Rat liver preservation by hypothermic oscillating liver perfusion compared to simple cold storage.

1998

Rat livers were preserved hypothermically for 10 or 24 h in vitro as if for transplantation. Two methods of preservation were compared using physiological and biochemical parameters: simple storage and oscillating perfusion. By measuring the nucleotides after preservation the calculated energy charge was significantly higher after 10 and 24 h of oscillating perfusion compared to the simple storage group. In addition, a significant energy charge loading was demonstrated by 10 h oscillating perfusion compared to the initial value prior to perfusion. The oscillating, computer-controlled perfusion permits continuous monitoring of perfusate temperature, O2 consumption, pCO2, portal vein pressure…

Inflammation-responsive focal constrictors in the mouse ear microcirculation

2006

In many capillary exchange beds, blood flow is locally regulated by precapillary sphincter-like activity. In this study, we used intravascular tracers and scanning electron microscopy to investigate precapillary blood flow regulation in the mouse ear. Gelatin ink injections of the normal mouse ear demonstrated 6.8 +/- 2.3 axial vessels with a cutoff of detectable tracer in the early branches: 19 +/- 11 focal constrictions were observed along the 1st to 5th order branches of the axial vessels. A perfusion tracer consisting of biotinylated anti-endothelial lectins (Ricinus Communis Agglutin, Lycopersicon Esculentum and Griffonia Simplicifolia) was circulated for 30 min under physiological con…

Upregulation of antibody response to heat shock proteins and tissue antigens in an ocular ischemia model.

2011

PURPOSE. The aim of this study was to characterize the serum antibody reactivities occurring after ocular ischemia reperfusion. The time course of serum antibody responses was examined. METHODS. Wistar rats were exposed to transient ocular ischemia by elevating intraocular pressure to 130 mm Hg for 60 minutes. Axonal damage was evaluated on optic-nerve sections 2 and 4 weeks later. Blood samples collected before and several times after ischemia were used for antibody detection via customized protein microarrays. Different tissue antigens, including heat shock proteins (HSPs) and crystallins, were selected based on previous identification of antibody reactivities in studies on ischemic event…

Non-viral VEGF(165) gene therapy--magnetofection of acoustically active magnetic lipospheres ('magnetobubbles') increases tissue survival in an overs…

2008

Abstract Adenoviral transduction of the VEGF gene in an oversized skin flap increases flap survival and perfusion. In this study, we investigated the potential of magnetofection of magnetic lipospheres containing VEGF165-cDNA on survival and perfusion of ischemic skin flaps and evaluated the method with respect to the significance of applied magnetic field and ultrasound. We prepared perfluoropropane-filled magnetic lipospheres (‘magnetobubbles’) from Tween60-coated magnetic nanoparticles, Metafectene, soybean-oil and cDNA and studied the effect in an oversized random-pattern-flap model in the rats (n= 46). VEGF-cDNA-magnetobubbles were administered under a magnetic field with simultaneousl…

Time sequence and site of fluid accumulation in experimental neurogenic pulmonary edema.

1976

The initial phase of pulmonary edema development following intracranial pressure elevation was studied by means of transmission electron microscopy. Using perfusion fixation and application of a blood tracer (HRP horseradish peroxidase) the time sequence and site of fluid leakage out of pulmonary vessels was demonstrated: - passage of edema fluid through intercellular clefts of alveolar capillary endothelium - edema accumulation in alveolar interstitial tissue - draining of edema fluid from the alveolar septum to the interstitium of terminal bronchioli and to lymphatic vessels. An early interepithelial fluid leakage out of the alveolar wall remains questionable.

Photodynamic therapy within edematous brain tissue: Considerations on sensitizer dose and time point of laser irradiation

1996

Photosensitizer is known to spread with vasogenic edema fluid arising from a cerebral lesion (Neurosurg 33:1075-1082, 1993), which may be essential for sensitizing malignant cells outside the main tumor mass. The present experiments seek to elucidate whether resultant necrosis of perifocal brain tissue after laser irradiation follows a corresponding time pattern and whether damage depends on the photosensitizer dose. Male Wistar rats were anaesthetized with chloralhydrate for venous cannulation, craniotomy and focal cold lesion in order to induce vasogenic edema. Simultaneously, Photofrin II (PF II) was administered at a dose of 5 mg kg-1. The animals were re-anaesthetized after either 4, 1…

Intestinal ischemia/reperfusion promotes brain damage via microglia activation: can we do something now?

2012

Perfusion Index and Pulse Oximetry Screening for Congenital Heart Defects

2017

Objective To evaluate the efficacy of combined pulse oximetry (POX) and perfusion index (PI) neonatal screening for severe congenital heart defects (sCHD) and assess different impacts of screening in tertiary and nontertiary hospitals. Study design A multicenter, prospective study in 10 tertiary and 6 nontertiary maternity hospitals. A total of 42 169 asymptomatic newborns from among 50 244 neonates were screened; exclusion criteria were antenatal sCHD diagnosis, postnatal clinically suspected sCHD, and neonatal intensive care unit admission. Eligible infants underwent pre- and postductal POX and PI screening after routine discharge examination. Targeted sCHD were anatomically defined. Posi…

Splenic blood flow and intrasplenic flow distribution in rats

1977

In 75 rats, anesthetized with pentobarbital and breathing spontaneously, regional splenic blood flow (rSBF) was measured by means of the85Kr(β)-clearance technique after an intraaortic slug injection of the dissolved indicator. In the normal and undisturbed spleen in situ rSBF is linearly related to the mean arterial blood pressure (MABP) within the range of 30–140 mm Hg. Mean rSBF is 0.71 ml/g/min, the mean arterial blood pressure being 105 mm Hg. In normal rats rSBF decreases significantly with increasing body weight or age. After total obstruction of the open circulation by application of rigid spherocytes, mean rSBF is reduced to 0.26 ml/g/min and is independent of the mean arterial blo…