Search results for "excretion"
showing 10 items of 145 documents
Internal exposure of firefighting instructors to polycyclic aromatic hydrocarbons (PAH) during live fire training
2019
Firefighting instructors in live fire training are inevitably exposed to emissions containing, carcinogenic PAH. The study investigated PAH uptake in a group of firefighting instructors during short-term exposure in live fire training by urinary biomonitoring. Six firefighting instructors (non-smokers) completed five 2 h-training sessions each in a carbonaceous-fired simulation unit using self-containing breathing apparatuses (SCBA). Complying with a minimum time interval of six days between the individual training sessions, the participants provided urine samples before and immediately after, as well as 1, 3, 6, 9, 11, and 18 h after each training session. Samples were analyzed for 10 mono…
Internal exposure of the general population to DEHP and other phthalates--determination of secondary and primary phthalate monoester metabolites in u…
2003
A number of phthalates and their metabolites are suspected of having teratogenic and endocrine disrupting effects. Especially the developmental and reproductive effects of di(2-ethylhexyl)phthalate (DEHP) are under scrutiny. In this study we determined the concentrations of the secondary, chain oxidized monoester metabolites of DEHP, mono(2-ethyl-5-hydroxyhexyl)phthalate (5OH-MEHP) and mono(2-ethyl-5-oxo-hexyl)phthalate (5oxo-MEHP) in urine samples from the general population. The utilization of the secondary metabolites minimized any risk of contamination by the ubiquitously present phthalate parent compounds. Included in the method were also the simple monoester metabolites of DEHP, dioct…
Teacher stress over an autumn term: relationships between subjective stress and catecholamine excretion during night rest
1987
The relationships between subjective stress and catecholamine excretion during night rest were investigated in a group of 137 teachers. The research design was longitudinal and consisted of repeated assessment (six times in an autumn term) of the stress indicators. At the beginning of the term adrenaline excretion rate showed negative and at the end of the term positive correlations with subjective stress feelings. Cluster analysis revealed three stable profile types among the teachers, in which the stress indicators were related to each other in different ways. The subjective stress process was better reflected in noradrenaline excretion than in adrenaline excretion. The findings were inte…
Uptake and elimination of permethrin related to the use of permethrin treated clothing for forestry workers
2014
Wearing of permethrin treated clothing usually implicates an uptake of permethrin by the user. Aim of our study was to examine the kinetics of internal permethrin exposure in volunteers during and after a single 8h-use of treated clothing as well as factors potentially influencing permethrin uptake. 28 male volunteers (age: 20-34 years) were equipped with permethrin treated jackets and pants from two different suppliers. The clothing was worn for 8h, simulating differing external conditions, including comfort conditions as well as conditions of increased temperature and humidity without and with additional physical workload. Internal permethrin exposure was monitored by determination of per…
Urinary excretion of heptanones, heptanoles and 2,5-heptanedione after controlled acute exposure of volunteers to n-heptane.
2018
A lack of well-established parameters and assessment values currently impairs biomonitoring of n-heptane exposure. Using controlled inhalation experiments, we collected information on urinary n-heptane metabolite concentrations and the time course of metabolite excretion. Relationships between external and internal exposure were analysed to investigate the suitability of selected metabolites to reflect n-heptane uptake. Twenty healthy, non-smoking males (aged 19-38 years, median 25.5) were exposed for 3 h to 167, 333 and 500 ppm n-heptane, each. Spot urine samples of the volunteers, collected before exposure and during the following 24 h, were analysed for heptane-2-one, 3-one, 4-one, 2,5-d…
Pharmacokinetics, pharmacodynamics, and safety of moss-aGalactosidase A in patients with Fabry disease.
2019
Moss-aGalactosidase A (moss-aGal) is a moss-derived version of human α-galactosidase developed for enzyme replacement therapy in patients with Fabry disease. It exhibits a homogenous N-glycosylation profile with >90% mannose-terminated glycans. In contrast to mammalian cell produced α-galactosidase, moss-aGal does not rely on mannose-6-phosphate receptor mediated endocytosis but targets the mannose receptor for tissue uptake. We conducted a phase 1 clinical trial with moss-aGal in six patients with confirmed diagnosis of Fabry disease during a 28-day schedule. All patients received a single dose of 0.2 mg/kg moss-aGal by i.v.-infusion. Primary endpoints of the trial were safety and pharmaco…
Interest of genotyping and phenotyping of drug-metabolizing enzymes for the interpretation of biological monitoring of exposure to styrene
2002
In the field of occupational and/or environmental toxicology, the measurement of specific metabolites in urine may serve to assess exposure to the parent compounds (biological monitoring of exposure). Styrene is one of the chemicals for which biological monitoring programs have been validated and implemented in environmental and occupational medicine. However, inter-individual differences in the urinary excretion exist both for the main end-products (mandelic acid and phenylglyoxylic acid) and for its specific mercapturic acids (phenylhydroxyethylmercapturic acids, PHEMA). This limits to a certain extent the use of these metabolites for an accurate assessment of styrene exposure. In a group…
Insulin-dependent diabetes mellitus and glycosaminoglycans.
1995
The influence of diabetic nephropathy on urinary glycosaminoglycan distribution was assessed in 96 patients with insulin-dependent diabetes mellitus (IDDM, 49 female, age: 16 - 64 yrs, median 35; duration of IDDM: 0 - 43 yrs, median 13 yrs) in comparison to 103 healthy controls (57 female, 17 - 82 yrs, median 40 yrs). Glycosaminoglycan concentration of 24 h urine samples was determined by means of precipitation with cethylpyridinium chloride and potassium acetate in ethanol followed by a colorimetric test with carbazole. A marked difference (p = 0.0008) in urinary glycosaminoglycan excretion between patients (19.0, 12.4, 35.6 mg/24 h, median, 25th, 75th percentile) and controls (15.8, 10.4,…
Prevalence of residual B-cell function related to age at onset and genetic profile in newly diagnosed type I diabetics.
1987
Patients with type I (insulin-dependent) diabetes mellitus maintain B-cell function for a varying period of time after onset. This is commonly held to account for post-initial remission. To estimate residual B-cell function we measured plasma and 24-h urinary C-peptide in 68 type I diabetic patients (age range 4-35 years, within 10-180 days of the onset of symptoms, typed for HLA-A, -B, -C and DR loci. A positive correlation (r = 0.26; p less than 0.05) was found between urinary C-peptide levels and the age of the patient. The analysis of variance of urinary C-peptide values on the basis of the presence or absence of DR3 and DR4 antigens revealed that the DR3-positive patients had reduced e…
Simultaneous assessment of endothelial function, nitric oxide synthase activity, nitric oxide-mediated signaling, and oxidative stress in individuals…
2007
Abstract Background: Endothelial function is impaired in hypercholesterolemia and atherosclerosis. Based on mostly indirect evidence, this impairment is attributed to reduced synthesis or impaired biological activity of endothelium-derived nitric oxide (NO). It was the aim of this study to directly estimate and compare whole-body NO production in normo- and hypercholesterolemia by applying a nonradioactive stable isotope dilution technique in vivo. Methods: We enrolled 12 normocholesterolemic and 24 hypercholesterolemic volunteers who were all clinically healthy. To assess whole-body NO synthesis, we intravenously administered l-[guanidino-(15N2)]-arginine and determined the urinary excreti…