Search results for "Constriction"
showing 10 items of 254 documents
Modulation of Spatial O2Tension Distribution in Experimental Tumors by Increasing Arterial O2Supply
1995
Tumor oxygenation has been measured polarographically in s.c. implanted DS-sarcomas on the dorsum of the hind foot of male Sprague-Dawley rats. pO2 was determined in all 3 spatial dimensions and 3-dimensional pO2 distributions as well as the mean extent of confluent areas with pO25 mmHg were calculated. Finally, the effect of elevating arterial pO2 (by carbogen breathing) as well as of increasing tumor blood flow (by angiotensin infusion) on the spatial pO2 distribution was analyzed. Depending on the tumor volume, the spatial pO2 distribution is more or less anisotropic. In smaller tumors, areas with physiological pO2 values are found adjacent to large hypoxic areas whereas larger tumors ar…
Intrahepatic bile duct dilation and gallbladder hydrops due to a cystic duct stenosis in a 2-month-old boy.
2015
A 2-month-old boy presented with slight diffuse abdominal pain after an uncomplicated pregnancy and perinatal period. Height (62 cm) and weight (5.5 kg) were according to the age. Routine blood tests showed no abnormalities except for a minimal elevation of aspartate aminotransferase to 38 units/L (reference range 5–35 U/L). Primary abdominal ultrasound showed a dilation of the common bile duct and a gallbladder hydrops (figure 1). MR cholangiopancreatography (MRCP) was indicated to detect the cause for these incidental findings. Contrary to normal bile ducts in …
Radiation exposure in biliary procedures performed to manage anastomotic strictures in pediatric liver transplant recipients: comparison between radi…
2013
The aim of this study was to estimate radiation exposure in pediatric liver transplants recipients who underwent biliary interventional procedures and to compare radiation exposure levels between biliary interventional procedures performed using an image intensifier-based angiographic system (IIDS) and a flat panel detector-based interventional system (FPDS). We enrolled 34 consecutive pediatric liver transplant recipients with biliary strictures between January 2008 and March 2013 with a total of 170 image-guided procedures. The dose-area product (DAP) and fluoroscopy time was recorded for each procedure. The mean age was 61 months (range 4–192), and mean weight was 17 kg (range 4–41). The…
Nutcracker syndrome due to left renal vein compression by an aberrant right renal artery
2007
Classic nutcracker syndrome is caused by left renal vein compression between the superior mesenteric artery and aorta, leading to retrograde venous hypertension associated with such urinary abnormalities as hematuria or proteinuria. We describe a case of symptomatic nutcracker syndrome treated by means of stent placement in which hypertension in the left renal vein was caused by stenosis of this vein compressed by an aberrant right renal artery at a point closer to the inferior vena cava.
Antihypertensive Mechanism of Lactoferrin-Derived Peptides: Angiotensin Receptor Blocking Effect
2013
Texto del artículo, no incluye figuras ni tablas.
Different muscarinic receptors mediate autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat isolated perfused heart
1990
Experiments were carried out on rat isolated perfused hearts with both vagus nerves attached. The acetylcholine stores were labelled with [14C]-choline. The effects of muscarinic receptor antagonists on the [14C]-overflow and increase in perfusion pressure evoked by vagus nerve stimulation (10 Hz, 4-10 mA) were studied in order to determine the muscarinic receptor type involved in autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat heart. Stimulation of the vagus nerves (1200 pulses) caused an increase in [14C]-overflow and in perfusion pressure which was significantly reduced by hexamethonium 500 mumol/l and abolished by tetrodotoxin 0.3 mumol/l or perfu…
Nitric oxide and prostacyclin lower suprasystemic pulmonary hypertension after cardiopulmonary bypass
1993
In a 3-week-old male newborn persistent suprasystemic pulmonary hypertension developed after surgical valvulotomy for a critical aortic valve stenosis. Because of a residual transvalvular pressure gradient of 35 mmHg and postoperative left as well as right ventricular dysfunction, treatment with inhaled nitric oxide (NO) and intravenously infused prostacyclin (PGI2) was attempted. Low-dose inhaled NO and low dose PGI2 corrected severe pulmonary hypertension and led to an increase in cardiac output. Treatment with NO but not PGI2 was accompanied by a rise in PaO2 and systemic blood pressure. Interruption of NO administration led to a rapid increase in pulmonary arterial pressure to suprasyst…
Novel antihypertensive hexa- and heptapeptides with ACE-inhibiting properties: From the in vitro ACE assay to the spontaneously hypertensive rat
2011
Bioactive ACE inhibiting peptides are gaining interest in hypertension treatment. We have designed and screened six synthetic heptapeptides (PACEI48 to PACEI53) based on two hexapeptide leads (PACEI32 and PACEI34) to improve ACE inhibitory properties and assess their antihypertensive effects. ACE activity was assayed in vitro and ex vivo. Selected peptides were administered to spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats. In vitro cytotoxicity was assessed with the MTT reduction test. The six heptapeptides at low micromolar concentration produced different degrees of in vitro inhibition of ACE activity using the synthetic substrate HHL or the natural subst…
Influence of nitric oxide on neurogenic contraction and relaxation of the human gastroepiploic artery.
2003
Abstract Background The objective of this study was to characterize the neurogenic contraction and relaxation of the human gastroepiploic artery and to determine whether the responses are mediated by nitric oxide (NO) from neural or endothelial origin. Methods Rings of human gastroepiploic artery were obtained from 18 patients (12 men, 6 women) undergoing gastrectomy. The rings were suspended in organ baths for isometric recording of tension. We studied the contractile and relaxant responses to electrical field stimulation. Results In arteries under resting conditions, electrical field stimulation (2 to 8 Hz) caused frequency-dependent contractions that were of greater magnitude in arteries…
Role of endothelium in the responses to noradrenaline in normal and sensitized guinea-pig aorta
1993
1. The pharmacological reactivity of sensitized blood vessels has been less studied than that of the airways. Aorta rings were obtained from normal (non-sensitized) and actively sensitized guinea-pigs, and prepared for isometric recording of tension changes. 2. Noradrenaline (10 nM-0.1 mM), histamine (0.1 microM-0.1 mM) and KCl (10-100 mM) produced concentration-related contractions of normal tissues. Removal of endothelium resulted in a marked leftward and upward shift of the concentration-response curve for noradrenaline but it did not alter histamine- or KCl-induced responses. Pretreatment with L-NG-nitroarginine (L-NOARG, 30 microM), haemoglobin (5 microM) or ibuprofen (10 microM) enhan…