Search results for "Perfusion"
showing 10 items of 714 documents
Functional MR imaging of pulmonary ventilation using hyperpolarized noble gases.
2000
The current status of experimental and clinical applications for functional MR imaging of pulmonary ventilation using hyperpolarized noble gases are reviewed. 3-helium (3He) and 129-xenon (129Xe) can be hyperpolarized by optical pumping techniques such as spin exchange or metastability exchange in sufficient amounts. This process leads to an artificial, non-equilibrium increase of the density of excited nuclei which represents the source of the MR signal. Those hyperpolarized gases are administered mostly via inhalation, and will fill airways and airspaces allowing for ventilation imaging. Recent human studies concentrate on imaging the airways and airspaces with high spatial resolution. N…
Effect of fluid resuscitation on cerebral integrity: A prospective randomised porcine study of haemorrhagic shock.
2021
BACKGROUND The treatment of haemorrhagic shock is a challenging task. Colloids have been regarded as standard treatment, but their safety and benefit have been the subject of controversial debates. Negative effects, including renal failure and increased mortality, have resulted in restrictions on their administration. The cerebral effects of different infusion regimens are largely unknown. OBJECTIVES The current study investigated the impact of gelatine-polysuccinate, hydroxyethyl starch (HES) and balanced electrolyte solution (BES) on cerebral integrity, focusing on cerebral inflammation, apoptosis and blood flow in pigs. DESIGN Randomised experimental study. SETTING University-affiliated …
Short-Time Ocular Ischemia Induces Vascular Endothelial Dysfunction and Ganglion Cell Loss in the Pig Retina
2019
Visual impairment and blindness are often caused by retinal ischemia-reperfusion (I/R) injury. We aimed to characterize a new model of I/R in pigs, in which the intraocular pathways were not manipulated by invasive methods on the ocular system. After 12 min of ischemia followed by 20 h of reperfusion, reactivity of retinal arterioles was measured in vitro by video microscopy. Dihydroethidium (DHE) staining, qPCR, immunohistochemistry, quantification of neurons in the retinal ganglion cell layer, and histological examination was performed. Retinal arterioles of I/R-treated pigs displayed marked attenuation in response to the endothelium-dependent vasodilator, bradykinin, compared to sham-tre…
Heat Shock Protein-60 and Risk for Cardiovascular Disease
2011
Cardiovascular disease (CVD) is a leading cause of morbidity and mortality worldwide. There is growing evidence that molecularchaperones, many of which are heat shock proteins HSPs, are involved in CVD pathogenesis. In this review we focus on HSP60,the human mitochondrial chaperone that also displays extramitochondrial and extracellular functions. HSP60 is typically cytoprotectivebut a number of stress conditions determine its conversion to a potentially toxic molecule for cells and tissues. We present illustrative examplesof specific subtypes of CVD where HSP60 is implicated in the initiation and/or progression of disease. The data not only indicatea pathogenic role for HSP60 but also its …
Optimizing the Personalized, Risk-Adjusted Management of Pulmonary Embolism: An Integrated Clinical Trial Programme
2018
Acute pulmonary embolism (PE) contributes significantly to the global burden of cardiovascular disease. The severity of the acute PE event determines the expected estimated risk of early death. This risk is influenced by the degree of dysfunction of the right ventricle (RV), as assessed by the presence of acute RV pressure overload on imaging and/or elevated cardiac biomarkers, and by demographic and clinical factors, including relevant comorbidities. Haemodynamic instability and cardiogenic shock is at the top of the PE severity spectrum, as it represents the most extreme manifestation of RV failure and a key determinant of poor prognosis. Ideally, risk-adjusted treatment should implement:…
Simple and convenient remote photoplethysmography system for monitoring regional anesthesia effectiveness
2017
Simple and inexpensive remote photoplethysmography system for monitoring the effectiveness of regional anesthesia was developed and tested. The system involves surgical lamp as light source, compact video camera and computer with custom developed software. Data from eight patients were processed and the effectiveness of regional anesthesia was calculated. The results showed that the standard surgical lamp can be used as a light source together with camera for remote monitoring of regional anesthesia effectiveness.
Novel dual-flow perfusion bioreactor for in vitro pre-screening of nanoparticles delivery: design, characterization and testing
2021
An advanced dual-flow perfusion bioreactor with a simple and compact design was developed and evaluated as a potential apparatus to reduce the gap between animal testing and drug administration to human subjects in clinical trials. All the experimental tests were carried out using an ad hoc Poly Lactic Acid (PLLA) scaffold synthesized via Thermally Induced Phase Separation (TIPS). The bioreactor shows a tunable radial flow throughout the microporous matrix of the scaffold. The radial perfusion was quantified both with permeability tests and with a mathematical model, applying a combination of Darcy's Theory, Bernoulli's Equation, and Poiseuille's Law. Finally, a diffusion test allowed to in…
The effect of Betanin parenteral pretreatment on Jejunal and pulmonary tissue histological architecture and inflammatory response after Jejunal ische…
2019
Intestinal ischemic-reperfusion (IR) injury has detrimental effects on both local and distant organs in the body. Betanin is known for its antioxidant properties, and it is found mostly in vegetables. Therefore, the aim of the present study was to test the hypothesis that betanin administration prior intestinal IR, may be beneficial in protecting jejunal mucosa and lung parenchyma against IR damage. Male specific pathogen-free Charles River Wistar rats were used (n = 42). Betanin (50 mg/kg) was administered intraperitoneally 30 min before ischemia of the superior mesenteric artery lasting 1 h, followed by 1, 4 and 24 h of reperfusion. Immunohistochemical as well as histomorphometrical analy…
Glaucoma e pressione arteriosa sistemica
2008
L’autore descrive il ruolo controverso dell’ipertensione arteriosa nell’evoluzione del glaucoma. La progressione del glaucoma, infatti, sembra essere correlata alla riduzione delle velocità di flusso ematico a livello retro bulbare che è finemente regolato per adattarsi alle variazioni dei bisogni metabolici durante il cambiamento della funzione visiva e per compensare il variare delle pressioni di perfusione. Questa autoregolazione però è presente finché la pressione di perfusione si mantiene entro un range di 25-60 mmHg. Una pressione arteriosa bassa comporta una perdita di autoregolazione e ad un'ischemia della papilla ottica . L'ipotensione notturna,pertanto, rilevata durante il trattam…