Search results for "Roca"
showing 10 items of 1893 documents
Digoxin concentrations in serum and cantharides blister fluid: correlations with cardiac response.
1987
The relationship between the pharmacokinetics and dynamics of digoxin was investigated using a skin blistering technique that allows experimental access to tissue fluid concentrations. Eight healthy volunteers received digoxin, 1.0 mg, and placebo intravenously according to a double-blind crossover design. Drug concentrations were determined during a 72-hour period in serum, urine, and cantharides blister fluid (CBF). Digoxin levels in the hypothetic peripheral compartments were calculated from serum concentrations. Digoxin effects (total electromechanical systole [QS2c], left ventricular ejection time [LVETc], preejection period [PEPc], QTc time, heart rate, and T wave amplitude) were meas…
Dose-response relationships and plasma concentrations of digitalis glycosides in man.
1978
An inter-individual, randomized, double-blind study of digitoxin (Dt) and β-acetyl digoxin (D) was performed in 120 healthy male volunteers. Groups of 10 persons each received orally D 0, 0.1, 0.2, 0.3, 0.4, 0.5 or 0.6 mg and Dt 0.04, 0.08, 0.12, or 0.16 mg daily for 7 days; Loading doses were given for the first three days. Plasma levels were measured with an86Rb-erythrocyte assay 24 h after the last dose. ECG, carotid artery pulse and phonocardiogram were recorded prior to (b) and 24 h after (a) the last dose. QTc, amplitude of T-waves in V2 to V6, electromechanical systole (QS2c) and left ventricular ejection time (LVETc) were measured. The differences between a and b (Δ-values) reflect …
Investigation into isoprenaline resistance in patients with obstructive lung disease
1974
12 patients with chronic obstructive lung disease have been studied in an investigation regarding the causes of resistance to isoprenaline. The effects of repeated intravenous doses of 10 µg isoprenaline were assessed by cross over comparison before and after infusions of isoprenaline and a placebo; the infusions lasted for 35 to 40 min and the amount of isoprenaline infused was 0.5 µg/min. Total resistance, thoracic gas volume (whole-body plethysmography) and heart rate (ECG) were measured. No decrease in bronchospasmolytic or positive chronotopic effects on single isoprenaline injections could be demonstrated after prolonged infusions of isoprenaline.
Gabor frames for classification of paroxysmal and persistent atrial fibrillation episodes
2016
[EN] In this study, we propose a new classification method for early differentiation of paroxysmal and persistent atrial fibrillation episodes, i.e. those which spontaneously or with external intervention will return to sinus rhythm within 7 days of onset from the ones where the arrhythmia is sustained for more than 7 days. Today, clinicians provide patients classification once the course of the arrhythmia has been disclosed. This classification problem is dealt with in this study. We study a sparse representation of surface electrocardiogram signals by means of Gabor frames and afterwards we apply a linear discriminant analysis. Thus, we provide an early discrimination, obtaining promising…
Papillary Thyroid microcarcinomas: a comparative study of the characteristics and risk factors at presentation in two cancer registries
2013
Papillary thyroid microcarcinoma (PTMC) is an indolent neoplasia, often asymptomatic and discovered incidentally. Some PTMCs, however, exhibit a more aggressive behavior, frequently recur, and can even cause cancer-related death.The aim of this study was to evaluate the prevalence of PTMCs and the associated risk factors at presentation in 2 thyroid cancer registries from areas with different genetic and environmental characteristics.We conducted a retrospective, observational study of all incident cases of PTMCs recorded over a 5-year period in the Sicilian Regional Registry for Thyroid Cancer (SRRTC) and in the Surveillance Epidemiology and End Results (SEER) US registry.The study took pl…
NOA-05 phase 2 trial of procarbazine and lomustine therapy in gliomatosis cerebri.
2011
The NOA-05 multicenter trial was performed to analyze the efficacy of primary chemotherapy with procarbazine and lomustine (PC) in patients with gliomatosis cerebri (GC) and to define clinical, imaging, and molecular factors influencing outcome.Thirty-five patients with previously untreated GC were treated with up to six 56-day courses of 110mg/m(2) lomustine on day 1 and 60mg/m(2) procarbazine on days 8 to 21. The primary endpoint was the rate of patients without therapy failure (defined as progressive disease, death from any cause, or termination of PC therapy before the end of course 4) at 8 months after the beginning of PC chemotherapy.The failure-free survival rate at 8 months was 50.3…
Investigating cardiac and respiratory determinants of heart rate variability in an information-theoretic framework.
2014
This study was aimed at comparing two alternative information-theoretic approaches for the combined analysis of heart rate variability (HRV) and respiration variability (RV). The approaches decompose the predictive information about HRV in two terms, quantifying respectively the information stored into HRV and that transferred to HRV from RV. Storage and transfer were assessed by the popular self entropy (SE) and transfer entropy (TE) measures, as well as by the alternative conditional SE (cSE) and cross entropy (CE) measures. The comparison was performed at a theoretical level, computing the exact values of the four measures for simulated cardiorespiratory dynamics, and on real data, estim…
Brain slow waves preceding time-locked visuo-motor performance.
1993
According to previous findings (Konttinen and Lyytinen, 1992), the slow brain negativity preceding the trigger pull in rifle‐shooting tends to be decreased in successful shots among experienced marksmen, whereas no such pattern is found among inexperienced subjects. This effect was interpreted as resulting mainly from optimal arousal. However, another explanation is examined here. The aim of the experiment was to investigate slow electrocortical changes associated with motor regulation and visual aiming related to shooting performance. Four variations on a shooting task were used, in which the visual and motor components were contrasted. Motor activity related to gun stabilization was found…
Predictive biomarkers for complicated acute appendicitis: A prospective Ecuadorian study.
2020
The aim of the study was to determine the usefulness of known biomarkers as pre-operative predictors of complicated acute appendicitis (CAA) and perforated appendicitis (PA).This was an observational, analytic, cross-sectional, and prospective study at Hospital Teodoro Maldonado Carbo (August 2016-December 2017). Evaluated biomarkers: white blood cells count, neutrophil percentage (N%), neutrophil-to-lymphocyte ratio, glucose, total bilirubin, C-reactive protein, and procalcitonin (PCT). The statistical analysis was performed by means of the area under the receiver operating characteristics (AUROC) curve estimation. Biomarkers' cutoff point was identified using Youden's index. Sensitivity, …
In-hospital complications of acute myocardial infarction in hypertensive subjects
2005
Recent studies have shown a worse in-hospital outcome in hypertensive than in normotensive patients with acute myocardial infarction (AMI), which has been attributed to more frequent complications. The aim of this study was to investigate clinical patterns, risk factors, and in-hospital complications in hypertensive and normotensive patients with AMI.Of 4994 consecutive patients with AMI admitted to the intensive care unit, hypertensive patients with first infarction (n = 915; mean age 68.8 +/- 11.4 years) and 915 gender- and age-matched normotensive subjects were retrospectively studied.In the univariate analysis, hypertensive subjects presented more frequently non-Q-wave infarction and ST…