Search results for "Constriction"
showing 10 items of 254 documents
Riociguat versus sildenafil on hypoxic pulmonary vasoconstriction and ventilation/perfusion matching
2017
Introduction Current treatment with vasodilators for pulmonary hypertension associated with respiratory diseases is limited by their inhibitory effect on hypoxic pulmonary vasoconstriction (HPV) and uncoupling effects on ventilation-perfusion (V'/Q'). Hypoxia is also a well-known modulator of the nitric oxide (NO) pathway, and may therefore differentially affect the responses to phosphodiesterase 5 (PDE5) inhibitors and soluble guanylyl cyclase (sGC) stimulators. So far, the effects of the sGC stimulator riociguat on HPV have been poorly characterized. Materials and methods Contraction was recorded in pulmonary arteries (PA) in a wire myograph. Anesthetized rats were catheterized to record …
Cross-clamping a porcelain aorta: an alternative technique for high-risk patients
2018
Background Aortic cross-clamping in patients with porcelain aorta is associated with high mortality and morbidity rates. The aim is to establish a new approach to improve the outcome in this high-risk population. Methods Between September 2007 and November 2012, 42 patients with an aortic (N.=33; 81.3±6.4 years) or mitral valve disease (N.=9; 80.3±5.7) combined with a porcelain aorta underwent aortic (AVR) or mitral valve replacement (MVR). After arterial cannulation via distal aortic arch or femoral artery, longitudinal aortotomy under total cardiopulmonary bypass (CPB) was performed. The aorta was slowly clamped, thus mobilized atherosclerotic material could leave the aorta through the op…
Endoscopic cytology in biliary strictures. Personal experience
2008
The differential diagnosis between malignant and benign biliary strictures is the cornerstone of the management of jaundiced patients. The aim of our study is to define the role of cytology of the bile withdrawn during endoscopic retrograde cholangiopancreatography (ERCP), to reach a diagnosis of the nature of biliary stricture.This retrospective study was conducted on 67 consecutive patients affected of ingravescent obstructive jaundice who underwent ERCP+/-PTE (percutaneous transhepatic endoscopic)+bile withdrawn+stenting. We founded hilar stricture in 21 patients (31.3%), middle third the common duct stricture in 17 (25.3%), and lower third stricture in 28 patients (41.4%). In one patien…
Late neointimal tissue growth behind the stent after intravascular gamma-radiation.
2003
To determine the nature of the changes of the vascular wall after intravascular brachytherapy in stented arteries leading to incomplete stent apposition.Stents were implanted in the infrarenal aortas of rabbits, and gamma-intravascular brachytherapy (18 Gy) or a sham radiation procedure was immediately implemented. The arteries were harvested at 6 months for histologic analyses.The external elastic lamina area, as well as the vascular wall area behind the stent, were significantly greater in irradiated vs. control arteries (8.94 +/- 0.68 mm2 vs. 6.87 +/- 0.40 mm2 [p0.001] and 1.56 +/- 0.13 mm2 vs. 0.72 +/- 0.07 mm2 [p0.001], respectively). The ratio of the intimal area behind the stent rela…
Effects of taurine on pulmonary responses to antigen in sensitized Brown-Norway rats.
2001
Oxidative stress appears relevant to asthma. Therefore, the effects of the antioxidant taurine (oral, 1 and 3 mmol x kg(-1) x day(-1) for 7 days before challenge) were examined on antigen-induced responses in sensitized Brown-Norway rats. Taurine did not reduce the bronchospasm produced by aerosol antigen but prevented airway hyperreactivity to 5-hydroxytryptamine (5-HT) at 24 h after antigen exposure, and reduced the eosinophils (from 0.178+/-0.038x10(6) to 0.044+/-0.014x10(6)* and 0.048+/-0.013x10(6)* cells ml(-1) in antigen and antigen+taurine 1 or 3 mmol x kg(-1), respectively; *P0.05 vs. antigen), lipid hydroperoxides, and Evans blue dye extravasation in bronchoalveolar lavage fluid. T…
Late-onset Crohn's disease: a comparison of disease behaviour and therapy with younger adult patients: the Italian Group for the Study of Inflammator…
2019
BACKGROUND Disease phenotype and outcome of late-onset Crohn's disease are still poorly defined. METHODS In this Italian nationwide multicentre retrospective study, patients diagnosed ≥65 years (late-onset) were compared with young adult-onset with 16-39 years and adult-onset Crohn's disease 40-64 years. Data were collected for 3 years following diagnosis. RESULTS A total of 631 patients (late-onset 153, adult-onset 161, young adult-onset 317) were included. Colonic disease was more frequent in late-onset (P < 0005), stenosing behaviour was more frequent than in adult-onset (P < 0003), but fistulising disease was uncommon. Surgery rates were not different between the three age groups. Syste…
Antihypertensive properties of lactoferricin B-derived peptides.
2010
A set of eight lactoferricin B (LfcinB)-derived peptides was examined for inhibitory effects on angiotensin I-converting enzyme (ACE) activity and ACE-dependent vasoconstriction, and their hypotensive effect in spontaneously hypertensive rats (SHR). Peptides were derived from different elongations both at the C-terminal and N-terminal ends of the representative peptide LfcinB(20-25), which is known as the LfcinB antimicrobial core. All of the eight LfcinB-derived peptides showed in vitro inhibitory effects on ACE activity with different IC(50) values. Moreover, seven of them showed ex vivo inhibitory effects on ACE-dependent vasoconstriction. No clear correlation between in vitro and ex viv…
Inhibition of myosin light chain kinase reduces brain edema formation after traumatic brain injury.
2010
The role of the endothelial contractile apparatus in the process of brain edema formation after brain trauma is not characterized. Phosphorylation of myosin light chains by myosin light chain kinases (MLCK) activates endothelial contractile elements and results in a rearrangement of the cytoskeleton. This may enhance post-traumatic blood-brain barrier dysfunction. In order to investigate the role of the MLCK on brain edema formation and blood-brain barrier permeability after brain injury, mice were anesthetized and subjected to a controlled cortical impact (CCI). MLCK expression is significantly up-regulated after CCI with a maximum 12 h post-injury. Specific inhibition of MLCK by ML-7 resu…
Pharmacological activity of PF-904 in guinea pig in vivo, and on human bronchus and neutrophils in vitro.
1997
The effects of PF-904 (4-amino-1-ethyl-6-methylpyrazino[2,3-c][1,2,6]thiadiazine 2,2-dioxide), a pyrazinothiadiazine derivative, were examined in guinea-pig airways in vivo, in human isolated bronchus and human polymorphonuclear leukocytes. PF-904 (12.5-200 mg/kg, intraduodenal) reduced bronchoconstriction in response to histamine, arachidonic acid, platelet-activating factor (PAF) and methacholine. PF-904 (50-200 mg/kg) prevented PAF-induced airways hyperreactivity and inhibited antigen-induced bronchoconstriction, airway microvascular leakage and eosinophil lung accumulation, but antigen-induced airways hyperresponsiveness was not reduced. PF-904 (1 microM-1 mM) produced complete inhibiti…
Role of Ca2+-Activated K+ Channels on Adrenergic Responses of Human Saphenous Vein
2006
Background We studied the participation of K + channels on the adrenergic responses in human saphenous veins as well as the intervention of dihydropyridine-sensitive Ca 2+ channels on modulation of adrenergic responses by K + channels blockade. Methods Saphenous vein rings were obtained from 40 patients undergoing coronary artery bypass surgery. The vein rings were suspended in organ bath chambers for isometric recording of tension. Results Iberiotoxin (10 −7 mol/L), an inhibitor of large conductance Ca 2+ -activated K + channels, and charybdotoxin (10 −7 mol/L), an inhibitor of both large and intermediate conductance Ca 2+ -activated K + channels, enhanced the contractions elicited by elec…