Search results for "Cyclic compound"
showing 10 items of 819 documents
Gentamicin, norfloxacin and lysozyme concentration in human tears: in vivo and in vitro study
1992
Hen's egg lysozyme (HEL) activity was measured in vitro with gentamicin and norfloxacin by a turbidimetric technique. Gentamicin at the concentration of 10(-3) M inhibited HEL activity by 39%, while 10(-3) M norfloxacin did not affect HEL activity. However, an in vivo study in healthy persons did not show any significant statistical difference in tear lysozyme activity when 0.3% gentamicin or 0.3% norfloxacin were topically applied.
Metabolism of [3-14C]coumarin to polar and covalently bound products by hepatic microsomes from the rat, Syrian hamster, gerbil and humans.
1992
The metabolism of 0.19 and 2.0 mM-[3-14C]coumarin to polar products and covalently bound metabolites has been studied with hepatic microsomes from the rat, Syrian hamster, Mongolian gerbil and humans. [3-14C]Coumarin was metabolized by liver microsomes from all species to a number of polar products and to metabolite(s) that became covalently bound to microsomal proteins. The polar products included 3-, 5- and 7-hydroxycoumarins, o-hydroxyphenylacetaldehyde and o-hydroxyphenylacetic acid. Coumarin 7-hydroxylation was observed in all species except the rat. With 0.19 mM-[3-14C]coumarin, 7-hydroxycoumarin was the major metabolite in human liver microsomes, whereas in the other species with 0.1…
Cytochrome P-450 mRNA expression in human liver and its relationship with enzyme activity.
2001
CYP activity and protein contents have been measured in human liver using different techniques. In contrast, CYP mRNA data are scarce and the relationships between CYP mRNA contents and activities have not been established. These studies deserve further attention because mRNA determinations by RT-PCR require a very small amount of material (e.g., liver needle biopsy) and could provide important data regarding CYP expression regulation. In this study we measured in 12 human liver samples the mRNA contents of 10 CYPs by quantitative RT-PCR and the metabolic activities using specific substrates. mRNA contents and activities showed high correlation coefficients for CYP1A1, CYP1A2, CYP3A4, CYP2D…
Doxepin and its metabolites in plasma and cerebrospinal fluid in depressed patients
1997
Little information exists on the concentrations of antidepressants and their metabolites in CSF. We measured plasma and CSF levels of trans-doxepin (trans-DOX) and DOX metabolites in 12 depressed patients treated with DOX (250 mg/day) for 6 days. Spinal taps and blood samples were taken on day 7, 10 h after drug administration. Trans-DOX, cis-desmethyldoxepin (cis-DM-DOX), trans-desmethyldoxepin (trans-DM-DOX) and di-desmethyldoxepin (DDM-DOX) were analyzed in CSF and plasma samples by HPLC with column-switching. Although DOX was given as a mixture of 85% trans-DOX and 15% of the pharmacologically more active cis-DOX, we found similar amounts of cis-DM-DOX and trans-DM-DOX in plasma (59.8 +…
Tap water consumers differ from non-consumers in chlorine flavor acceptability but not sensitivity
2010
International audience; Unpleasant taste and especially chlorine flavor is one of the most common reasons advocated for choosing tap water alternatives as drinking water. As a consequence, the putative link between sensitivity to chlorine flavor and tap water consumption is an issue in drinking water habits studies. In the present study, we set out to examine such a link following a strategy in which we measured chlorine flavor perception at threshold and supra-threshold level for two groups of participants selected on their drinking water consumption habits. The first group included exclusive tap water consumers and the second group included exclusive bottled water consumers. In a first ex…
Adapting to the pandemic: longitudinal effects of social restrictions on time perception and boredom during the Covid-19 pandemic in Germany
2022
AbstractWith the Covid-19 pandemic, many governments introduced nationwide lockdowns that disrupted people’s daily routines and promoted social isolation. We applied a longitudinal online survey to investigate the mid-term effects of the mandated restrictions on the perceived passage of time (PPT) and boredom during and after a strict lockdown in Germany. One week after the beginning of the lockdown in March 2020, respondents reported a slower PPT and increased boredom compared to the pre-pandemic level. However, in the course of the lockdown, PPT accelerated and boredom decreased again until August 2020. Then, in October 2020, when incidence rates sharply rose and new restrictions were int…
Disinfection by-products effect on swimmers oxidative stress and respiratory damage.
2015
Disinfection by-products (DBPs) are generated through the reaction of chlorine with organic and inorganic matter in indoor swimming pools. Different DBPs are present in indoor swimming pools. This study evaluated the effects of different chlorinated formations in oxidative stress and lung damage in 20 swimmers after 40 min of aerobic swimming in 3 indoor pools with different characteristics. Biological samples were collected to measure lung damage (serum-surfactant-associated proteins A and B), oxidative stress parameters (plasma protein carbonylation and malondialdehyde, and whole-blood glutathione oxidation), and swimming exertion values (blood lactate) before and after exercise. Free chl…
Can Graduated Compressive Stockings Reduce Muscle Activity During Running?
2017
Purpose: Graduated compressive stockings (GCS) have been suggested to influence performance by reducing muscle oscillations and improving muscle function and efficiency. However, no study to date has analyzed the influence of GCS on muscle activity during running. The objective of the study was to analyze the influence of GCS on the perception of comfort and muscle activation of the main muscles of the lower leg during running. Method: Thirty-six participants ran on a treadmill with (GCS) or without (control) GCS. The running tests consisted of a 10-min warm-up followed by a 20-min intense run at 75% of the athlete’s maximal aerobic speed. Surface electromyography of the tibialis anterior, …
AZT treatment induces molecular and ultrastructural oxidative damage to muscle mitochondria. Prevention by antioxidant vitamins.
1998
AIDS patients who receive zidovudine (AZT) frequently suffer from myopathy. This has been attributed to mitochondrial (mt) damage, and specifically to the loss of mtDNA. This study examines whether AZT causes oxidative damage to DNA in patients and to skeletal muscle mitochondria in mice, and whether this damage may be prevented by supranutritional doses of antioxidant vitamins. Asymptomatic HIV-infected patients treated with AZT have a higher urinary excretion (355+/-100 pmol/kg/d) of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxo-dG) (a marker of oxidative damage to DNA) than untreated controls (asymptomatic HIV-infected patients) (182+/-29 pmol/kg/d). This was prevented (110+/-79 pmol/kg/d)…
Effect of alpha-linolenic acid in combination with the flavonol quercetin on markers of cardiovascular disease risk in healthy, non-obese adults: A r…
2019
Abstract Objectives Alpha-linolenic acid (ALA) and quercetin are characteristic compounds in plant-based diets. Cardioprotective effects have been described for both substances, although a possible benefit of combining ALA and quercetin has not, to our knowledge, been evaluated yet. The aim of this study was to investigate the potential independent and additive effects of ALA and quercetin on blood pressure (BP) and lipid and glucose metabolism, as well as on biomarkers of inflammation, oxidative stress, and antioxidant status in healthy, non-obese men and women. Another aim was to examine whether chronic supplementation of supranutritional doses of quercetin would result in an accumulation…