Search results for "Kinetic"
showing 10 items of 3064 documents
Progressive versus rapid rate of contraction during 7 wk of isometric resistance training.
2001
The aim of this study was to compare the effects of isometric training performed with progressive versus rapid rate of contraction on the knee extensor neuromuscular properties over a 7-wk period.Sixteen healthy male subjects trained quadriceps femoris muscle in a leg extension machine three times a week during 7 wk. The training sessions consisted of six sets of six maximal isometric contractions. A first group trained by performing progressive contractions lasting 4 s, whereas a second group performed contractions with a rapid rate of contraction (i.e., ballistic contractions) lasting about 1 s.Both groups significantly increased the isometric and isokinetic voluntary torque, and the resp…
Effects of fatigue and recovery on electromyographic and isometric force- and relaxation-time characteristics of human skeletal muscle
1986
Effects of fatigue produced by a maintained 60% isometric loading on electromyographic and isometric force-time and relaxation-time characteristics of human skeletal muscle were studied in 21 males accustomed to strength training. Fatigue loading resulted in a slight but not significant change in the maximal integrated EMG of a maximal isometric contraction, and a large decrease (20.4 +/- 6.3%, p less than 0.001) in maximal force. Fatigue loading increased (p less than 0.05-0.01) neural activation of the muscles during rapidly produced submaximal isometric forces, but had a considerable adverse effect (p less than 0.001) on the corresponding force-time characteristics. Correlations between …
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…
Selection of optimal prophylactic aminoglycoside dosage in cancer patients: population pharmacokinetic approaches.
1994
We report an alternative dose-finding approach for the selection of optimal prophylactic aminoglycoside dosage in specific (sub)populations of patients. Relative a priori utility of several intervals of gentamicin or tobramycin (AMG) peak and trough serum levels were assigned by a group of pharmacokinetics experts, assuming prophylactic administration for laryngectomy interventions. A group of 27 adult patients, with normal renal function, undergoing elective surgery for laryngeal problems and treated prophylactically with gentamicin (80 mg t.i.d.) or tobramycin (100 mg t.i.d.) was studied. Two blood samples (peak and trough) were drawn at steady-state for AMG assay. Three different methods…
Retrobulbar adipocytes and humoral immunity in Graves' ophthalmopathy
1993
As CT and MR-imaging revealed an enlargement of retrobulbar fat tissue in patients with Graves' ophthalmopathy, the role of the retrobulbar adipocytes in the pathogenesis of this disorder remains to be elucidated. To evaluate the in vitro influence of humoral immunity on retrobulbar adipose tissue, the effects of IgG and sera from 56 euthyroid ophthalmopathy patients and 53 controls on both porcine and human (patients' and controls') retrobulbar adipocytes were measured by means of several assays: An enzyme-linked immunosorbent assay was employed to reveal specific binding of antibodies to the adipocytes. Metabolic activity was determined by means of a colorimetric dimethyl thiazolium-diphe…
Augmented glucose-6-phosphate dehydrogenase activity and normal penetration and metabolism of dehydroepiandrosterone in mononuclear leukocytes in pso…
1986
The aim of the study was to determine a biochemical basis for the augmented oxidative metabolism found in mononuclear leukocytes (MNL) of patients with active psoriasis. Dehydroepiandrosterone (DHEA) is known to inhibit glucose-6-phosphate dehydrogenase (G-6-PDH). We determined the activity of G-6-PDH as well as the penetration and metabolism of DHEA - diminished plasma concentrations of which have been found in psoriatics previously - in 16 patients with active psoriasis and 16 controls. MNL in patients with psoriasis possessed 52% more (p less than 0.05) G-6-PDH activity, based on cell number, and 34% more (p less than 0.05) activity, based on soluble protein. No difference in DHEA penetr…
Elimination of beta-hexachlorocyclohexane in occupationally exposed persons.
1997
The elimination of beta-hexachlorocyclohexane (beta-HCH) in humans was investigated in a group of 40 former workers of a lindane-producing plant by analyzing at least 2 blood specimens (3 specimens in 3 workers) from different time points. Assuming a first-order kinetic model for excretion, the median half-life of beta-HCH is 7.2 yr calculated by concentrations in whole blood and 7.6 yr calculated by concentrations in extractable lipids. In univariate analyses an influence of age, percent body fat, and liver disease (additionally in whole blood an influence of contents of extractable lipids) on clearance was observed. All factors show a positive correlation with half-life. According to a mu…
Functional correlates of vertical gaze palsy and other ocular motor deficits in PSP: An FDG-PET study
2014
Abstract Objective To determine the functional correlates of vertical gaze palsy and other ocular motor deficits in patients with progressive supranuclear palsy (PSP) using [ 18 F]fluorodeoxyglucose (FDG-)PET. Methods Twenty-six patients with PSP underwent clinical examination of vertical gaze combined with FDG-PET scans to assess regional cerebral glucose metabolism as a marker of neuronal activity. Of these, eighteen PSP patients were also investigated by electrical nystagmography to determine horizontal ocular motor deficits. Statistical parametric mapping analyses were performed to correlate regional neuronal activity with ocular motor functions. Results In categorical comparisons, pati…
Optokinetic stimulation affects temporal estimation in healthy humans
2007
The representation of time and space are closely linked in the cognitive system. Optokinetic stimulation modulates spatial attention in healthy subjects and patients with spatial neglect. In order to evaluate whether optokinetic stimulation could influence time perception, a group of healthy subjects performed "time-comparison" tasks of sub- and supra-second intervals before and after leftward or rightward optokinetic stimulation. Subjective time perception was biased by the direction of optokinetic stimulation. Rightward optokinetic stimulation induced an overestimation of time perception compared with baseline and leftward optokinetic stimulation. These results indicate a directional bias…
3D characterisation of the dynamics of foot joints of adults during walking. Gait pattern identification
2017
A detailed description of the kinematics and kinetics of the ankle, midtarsal and metatarsophalangeal joints of the feet of a healthy adult male population during barefoot walking is provided. Plots of the angles and moments in each plane during the stance phase are reported, along with the mean and standard deviation values of 87 different parameters that characterise the 3D dynamics of the foot joints. These parameters were used to check for similarities between subjects through a hierarchical analysis that allowed three different gait patterns to be identified, most of the differences corresponding to the frontal and transverse planes.