Search results for "clearance"
showing 10 items of 116 documents
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…
Albumin clearance from human skeletal muscle during prolonged steady-state running.
2001
This study was designed to find out if the lymph flow, indicated as albumin clearance, from active skeletal muscle is maintained constant during a prolonged steady-state exercise. 99mTc-labelled albumin was injected bilaterally into the vastus lateralis muscles of eight endurance-trained men. The radioactivity at the injection site was monitored by a gamma-camera before, frequently during, and after a 2 h run at a controlled steady intensity of 69 +/- 4% of the maximal heart rate. The fractional clearance rate of albumin was calculated for each monitoring interval, and was expressed as percentage clearance per minute (% min(-1)). During the first 15 min of exercise the clearance rate was fi…
Transforming growth factor beta1 T29C gene polymorphism and hypertension: relationship with cardiovascular and renal damage.
2008
Distribution of T29C TGFβ1 gene polymorphism was analysed in 260 hypertensive and 134 normotensive subjects. Circulating TGFβ1 and procollagen type III levels, microalbuminuria, left ventricular geometry and function were evaluated in all the hypertensives subgrouped according to T29C TGFβ1 gene polymorphism. Circulating TGFβ1 by ELISA technique, procollagen type III by a specific radioimmunoassay, microalbuminuria by radioimmunoassay, left ventricular geometry and function by echocardiography were determined. All groups were comparable for gender, age and sex. Regarding T29C TGFβ1 gene polymorphism, prevalence of TC or CC genotypes was significantly (p < 0.05) higher in hypertensives th…
Comparison of creatinine and inulin clearances in multiple trauma
1990
Creatinine clearance (Ccr) is a good predictor of renal dysfunction. However, numerous analytical interferences have been observed with the classical measurement of creatinine by Jaffé's procedure. This prospective study was conducted to compare 4 methods for determining creatinine; and also endogenous creatinine clearance with inulin clearance (Cin) to estimate the glomerular filtration rate. The 4 different techniques for measuring creatinine were: 1) 2 techniques using Jaffé's colorimetric reaction: one with rapid and the other with slow kinetics: 2) 2 more selective methods: enzymatic procedure and high performance liquid chromatography (HPLC). Measurements were performed in 13 multiple…
The exposure of healthy volunteers to 200 ppm 1,1,1-trichloroethane increases the concentration of proinflammatory cytokines in nasal secretions
1999
Objectives: Irritating effects of organic solvents have usually been measured by means of questionnaires. The aim of the present study was to evaluate the sensitivity of different methods of detecting subclinical irritating effects. Methods: Twelve healthy, non-smoking students were exposed to 200 ppm and to 20 ppm 1,1,1-trichloroethane in an exposure chamber, using a crossover design. The amounts of interleukins (IL)-1β, IL-6 and IL-8 and prostaglandin E2 (PGE2) in nasal secretions were measured. Mucociliary transport time was determined with the saccharine test. Ciliary beat frequency of nasal epithelial cells was measured with video-interference contrast microscopy. Subjective symptoms w…
Elevated [18F]FDOPA utilization in the periaqueductal gray and medial nucleus accumbens of patients with early Parkinson's disease
2010
Udgivelsesdato: 2010-Feb-15 PET studies with the DOPA decarboxylase substrate 6-[(18)F]fluoro-l-DOPA (FDOPA) reveal the storage of [(18)F]-fluorodopamine within synaptic vesicles, mainly of dopamine fibres. As such, FDOPA PET is a sensitive indicator of the integrity of the nigrostriatal dopamine innervation. Nonetheless, there have been several reports of focal elevations of FDOPA utilization in brain of patients with Parkinson's disease (PD), all based on reference tissue methods. To investigate this phenomenon further, we used voxel-wise steady-state kinetic analysis to search for regions of elevated FDOPA utilization (K; ml g(-1) min(-1)) and steady-state trapping (V(d); ml g(-1)) in a …
Estimation of pharmacokinetic parameters of lithium from saliva and urine
1974
The salivary and urinary excretion of lithium was studied in three healthy male sub;ects after oral administration of two or three different doses. In all individuals the concentration of lithium in salivary fluid was found to be 2.2 to 3.3 times as high as the concentration in plasma. In each sub;ect the saliva:plasma concentration ratio remained constant over more than a 100 fold concentration range for at least 3 months. This ratio was not markedly affected by about tenfold changes in saliva flow rate. Thus, pharmacokinetic parameters obtained from salivary excretion data are in agreement with those obtained from plasma concentration and urinary excretion rate data, and renal clearance o…
Lymph flow dynamics in exercising human skeletal muscle as detected by scintography
1997
1. The effects of dynamic and isometric muscle contractions on the lymph flow dynamics in human skeletal muscle were studied with a scintographic method. 2. Radioactively labelled human serum albumin (99mTc-HSA) was injected bilaterally into the vastus lateralis muscles of eight men (n = 16), four of whom had had an endurance training background. The subjects performed 100 submaximal contractions in 10 min as (i) dynamic knee extensions (CONS), (ii) isometric contractions with the knees at full extension (IMExt), or (iii) isometric contractions with knees fixed at 90 deg angle flexion (IMFlex). The exercises were separated by 65 min periods in supine rest. The level of radioactivity at the …
Radiofrequency, high-frequency, and electrocautery treatments vs partial inferior turbinotomy: microscopic and macroscopic effects on nasal mucosa.
2009
Objective To compare the microscopic and macroscopic effects of radiofrequency, high-frequency, and electrocautery therapies with partial inferior turbinotomy in the treatment of nasal obstruction caused by inferior turbinate hypertrophy. Design Nonrandomized controlled trial. Setting Department of Otolaryngology–Head and Neck Surgery, University of Genoa. Patients The study included 80 patients affected by nasal obstruction from hypertrophied inferior turbinates. Interventions Homogeneous patient groups A, B, C, and D underwent radiofrequency, high-frequency, and electrocautery treatments and partial inferior turbinotomy, respectively, to surgically reduce hypertrophied inferior turbinates…
A Multicenter Trial of Specific Local Nasal Immunotherapy
2000
Objective: To assess the efficacy and safety of specific local nasal immunotherapy (LNIT) in powder form in patients with allergic rhinitis, using subjective and objective parameters. Study Design: A double-blind randomized multicenter trial of 102 patients with allergic rhinitis who were treated with specific LNIT for 8 consecutive months. Methods: After identifying allergens with the skin prick test and sensitization threshold dose with the specific nasal provocation test, 102 patients were selected, of whom 55 were allergic to mites and 47 were allergic to Graminaceae or Parietaria pollen. The specific treatments were self-administered using an insufflator in two phases (phase 1: increas…