Search results for "Ostas"
showing 10 items of 874 documents
A homeostatic mechanism counteracting K+-evoked choline release in adult brain
2002
Choline (Ch) is an essential nutrient as the biosynthetic precursor of acetylcholine (ACh) and phospholipids. Under resting conditions, the intracellular accumulation of Ch (above 10-fold), which is positively charged, is governed by the membrane potential and follows the Nernst equation. Accordingly, in synaptosomes from adult rats during depolarization, we observed a linear relationship between release of free cytoplasmic Ch and KCl concentration (2.7-120 mm). The K(+) -evoked Ch release was Ca(2+) -independent and did not originate from ACh or phospholipid hydrolysis. In superfused brain slices of adult rats, however, a K(+) -induced Ch efflux was absent. Also, under in vivo conditions, …
Glucocorticoids as modulators of expression and activity of Antithrombin (At): potential clinical relevance.
2014
Abstract Introduction An inverse relationship has been reported between decreased postoperative Antithrombin (AT) plasmatic levels and the incidence of complications. We hypothesized that Nuclear Hormone Receptors could modulate the expression of SERPINC1 , encoding AT, through a Hormone Regulatory Element present in its promoter, and thus hormone analogs could be a pharmacological complement in surgical procedures to activate endogenous AT synthesis. Materials and Methods The expression of SERPINC1 was analyzed in HepG2 cells by quantitative RT-PCR and Western Blot. Two studies were conducted with (a) patients submitted to cardiac surgery with cardiopulmonary bypass receiving (n =17) or no…
Minor hepatic resection using heat coagulative necrosis
2009
Intra- and postoperative bleeding represents an extremely serious and frequent complication of hepatic surgery. In this study, we evaluated the effectiveness of a radiofrequency (RF) device using heat to cause coagulative necrosis of the hepatic parenchyma to control hemostasis in minor hepatic resection. Between December 2005 and November 2007, a study was conducted of 21 patients undergoing 22 hepatic resections with the RF-assisted technique. Sixteen of these were affected by hepatocellular carcinoma and five had liver metastases from colorectal cancer. Intraoperative blood loss, the need for blood transfusion, the complication rates, operating times, and the duration of postoperative h…
Minor hepatic resection for hepatocellular carcinoma in cirrhotic patients: Kelly clamp crushing resection versus heat coagulative necrosis with bipo…
2011
Hemorrhage and postoperative liver insufficiency are frequent and serious complications of hepatic resection in cirrhotic patients. The aim of this study was to assess retrospectively whether the surgical techniques using Kelly clamp crushing resection or heat coagulative necrosis with a bipolar radiofrequency device can reduce the incidence of the above complications and an eventual recurrence of neoplasia on the liver slice. We retrospectively reviewed the results of 35 patients who had undergone resection for monofocal hepatocellular carcinoma at our center. Thirteen patients (Group A) had undergone liver resection with Kelly clamp crushing resection, 22 patients (Group B) had had liver…
Murine tissue factor disulfide mutation causes a bleeding phenotype with sex specific organ pathology and lethality.
2019
Tissue factor is highly expressed in sub-endothelial tissue. The extracellular allosteric disulfide bond Cys186-Cys209 of human tissue factor shows high evolutionary conservation and in vitro evidence suggests that it significantly contributes to tissue factor procoagulant activity. To investigate the role of this allosteric disulfide bond in vivo, we generated a C213G mutant tissue factor mouse by replacing Cys213 of the corresponding disulfide Cys190-Cys213 in murine tissue factor. A bleeding phenotype was prominent in homozygous C213G tissue factor mice. Pre-natal lethality of 1/3rd of homozygous offspring was observed between E9.5 and E14.5 associated with placental hemorrhages. After b…
Impaired cerebrovascular autoregulation in patients with severe sepsis and sepsis-associated delirium
2012
Introduction Sepsis-associated delirium (SAD) increases morbidity in septic patients and, therefore, factors contributing to SAD should be further characterized. One possible mechanism might be the impairment of cerebrovascular autoregulation (AR) by sepsis, leading to cerebral hypo- or hyperperfusion in these haemodynamically unstable patients. Therefore, the present study investigates the relationship between the incidence of SAD and the status of AR during sepsis. Methods Cerebral blood flow velocity was measured using transcranial Doppler sonography and was correlated with the invasive arterial blood pressure curve to calculate the index of AR Mx (Mx>0.3 indicates impaired AR). Mx was m…
Total Thyroidectomy Performed With the Starion Vessel Sealing System Versus the Conventional Technique: A Prospective Randomized Trial
2010
Meticulous dissection and accurate hemostasis are required in thyroid surgery. The authors recently performed a number of thyroidectomies using a new device that combines heat and pressure for sealing and cutting tissue. A prospective randomized trial was conducted on 98 patients subjected to total thyroidectomy for benign disease: 49 patients (group A) with the Starion tissue welding system and 49 (group B) with the clamp-and-tie technique. The 2 groups were comparable in mean age, gender, thyroidal volume (20-60 mL), incision length (<35 mm), and pathology. The authors evaluated operative time, postoperative serum calcemia, dosage and length of postoperative calcium and vitamin D trea…
Uptake and metabolism of choline by rat brain after acute choline administration.
1992
The present study is concerned with the uptake and metabolism of choline by the rat brain. Intraperitoneal administration of choline chloride (4-60 mg/kg) caused a dose-dependent elevation of the plasma choline concentration from 11.8 to up to 165.2 microM within 10 min and the reversal of the negative arteriovenous difference (AVD) of choline across the brain to positive values at plasma choline levels of greater than 23 microM. Net choline release and uptake were linearly dependent on the plasma choline level in the physiological range of 10-50 microM, whereas the CSF choline level was significantly increased only at plasma choline levels of greater than 50 microM. The bolus injection of …
Impaired Cerebrovascular Autoregulation in Large Vessel Occlusive Stroke after Successful Mechanical Thrombectomy: A Prospective Cohort Study
2020
Abstract Introduction: Successful thrombectomy improves morbidity and mortality after stroke. The present prospective, observational cohort study investigated a potential correlation between the successful restoration of tissue perfusion by mechanical thrombectomy and intact cerebrovascular autoregulation (CA). Objective: Status of CA in patients with large vessel occlusive stroke after thrombectomy. Methods: After thrombectomy CA was measured using transcranial Doppler ultrasound. For this purpose a moving correlation index (Mxa) based on spontaneous arterial blood pressure fluctuations and corresponding cerebral blood flow velocity changes was calculated. CA impairment was defined by Mxa …
Human leukocyte/endothelial cell interactions and mitochondrial dysfunction in type 2 diabetic patients and their association with silent myocardial …
2013
OBJECTIVE Diabetes is associated with oxidative stress and increased mortality, but a possible correlation between leukocyte-endothelium interactions, oxidative stress, and silent myocardial ischemia (SMI) is yet to be confirmed. RESEARCH DESIGN AND METHODS Mitochondrial dysfunction and interactions between leukocytes and human umbilical vein endothelial cells were evaluated in 200 type 2 diabetic patients (25 with SMI) and 60 body composition– and age-matched control subjects. A possible correlation between these parameters and the onset of SMI was explored, and anthropometric and metabolic parameters were also analyzed. RESULTS Waist, levels of triglycerides, proinflammatory cytokines (i…