Search results for "caffeine"
showing 10 items of 118 documents
Coordinate mutation and transformation of mouse fibroblasts: induction by nitroquinoline oxide and modulation by caffeine
1981
Mutation and malignant transformation were followed in the same cells. Mouse fibroblasts (C3H 10T 1/2) were mutated and transformed by 4-nitroquinoline-1-oxide with similar, approximately linear dose-responses. The presence of caffeine immediately after exposure to 4-nitroquinoline-1-oxide potently inhibited mutation and transformation at high but not at low doses of 4-nitroquinoline-1-oxide. Whilst the coordinate induction of mutation and transformation could be explained by both a common target (DNA) or a common reactive species hitting several targets, the identical modulation by a DNA repair inhibitor of both end points suggests fundamental similarities in the nature of the lesions lead…
Evidence that depletion of internal calcium stores sensitive to noradrenaline elicits a contractile response dependent on extracellular calcium in ra…
1993
1. Noradrenaline 1 microM induced a contractile response in rat isolated aorta in the presence or in the absence of extracellular Ca2+ with depletion of intracellular Ca2+ stores. Thereafter, during incubation in the presence of Ca2+, an increase in the resting tone was observed. Such a contractile response did not occur after exposure to caffeine or 5-hydroxytryptamine. 2. This increase in tension was inhibited in a concentration-dependent manner by alpha-adrenoceptor antagonists (prazosin, phentolamine and yohimbine), the non-specific relaxing compound, papaverine and by the Ca(2+)-entry blocker, nifedipine. Therefore, this contractile process is related to depletion of Ca2+ stores sensit…
Methylphenidate, modafinil, and caffeine for cognitive enhancement in chess: A double-blind, randomised controlled trial.
2017
Stimulants and caffeine have been proposed for cognitive enhancement by healthy subjects. This study investigated whether performance in chess - a competitive mind game requiring highly complex cognitive skills - can be enhanced by methylphenidate, modafinil or caffeine. In a phase IV, randomized, double-blind, placebo-controlled trial, 39 male chess players received 2×200mg modafinil, 2×20mg methylphenidate, and 2×200mg caffeine or placebo in a 4×4 crossover design. They played twenty 15-minute games during two sessions against a chess program (Fritz 12; adapted to players' strength) and completed several neuropsychological tests. Marked substance effects were observed since all three subs…
Salivary protein profiles and sensitivity to the bitter taste of caffeine.
2011
WOS: 000298381900008; International audience; The interindividual variation in the sensitivity to bitterness is attributed in part to genetic polymorphism at the taste receptor level, but other factors, such as saliva composition, might be involved. In order to investigate this, 2 groups of subjects (hyposensitive, hypersensitive) were selected from 29 healthy male volunteers based on their detection thresholds for caffeine, and their salivary proteome composition was compared. Abundance of 26 of the 255 spots detected on saliva electrophoretic patterns was significantly different between hypo- and hypersensitive subjects. Saliva of hypersensitive subjects contained higher levels of amylase…
P5313The association between coffee and caffeine consumption and renal function: insight from individual-level data, Mendelian randomization, and met…
2019
Abstract Background The reported relationship between coffee intake and renal function is poorly understood. Purpose By applying on two-sample Mendelian randomization (MR) and systematic review and meta-analysis we investigated the association between caffeine and coffee intake with prevalent CKD and markers of renal function. Methods For the individual data analysis we analysed the NHANES data on renal function markers and caffeine intake. MR was implemented by using summary-level data from genome-wide association studies conducted on coffee intake (N=91,462) and kidney function (N=133,413). Inverse variance weighted method (IVW), weighted median-based method, MR-Egger, MR-RAPS, MR-PRESSO …
The potential link between episodes of diverticulitis or hemorrhoidal proctitis and diets with selected plant foods : a case-control study
2021
Diverticulitis and hemorrhoidal proctitis in the population are significant public health problems. We studied the potential association between the intake of certain plant foods and diverticulitis or hemorrhoidal episodes through a case–control study including 410 cases and 401 controls. We used a semiquantitative food frequency questionnaire. The intake was additionally quantified according to a 24 h recall. The plant foods or derived food products were categorized by their main chemical components into ethanol, caffeine/theine/theobromine, capsaicin, alliin, acids, eugenol, and miscellaneous foods such as curcumin. The mean score for overall intake of plant foods under consideration was …
Crystal structure of the tetraaquabis(thiocyanato-kappa N)cobalt(II)-caffeine-water (1/2/4) co-crystal
2017
In the structure of the title compound, [Co(NCS)2(H2O)4]·2C8H10N4O2·4H2O, the cobalt metal lies on an inversion centre and is coordinated in a slightly distorted octahedral geometry. In the crystal, the complex molecules interact with the caffeine molecules through O—H⋯N, O—H⋯O, C–H⋯S hydrogen bonds and π–π interactions.
Effects of Caffeine as an Adjuvant to Morphine in Advanced Cancer Patients
2001
Psychomotor abnormalities are one of the complications of opioid therapy in advanced cancer patients. Caffeine has potential properties to counteract the central effects of morphine. Twelve patients receiving stable doses of slow release morphine with adequate pain relief were scheduled for this double-blind placebo-controlled crossover trial. The treatment consisted of an intravenous dose of 1/6 of the daily morphine dose, using an intravenous/oral conversion ratio of 1:3. The dose calculated was administered in 5 minutes. Patients were randomly divided to received in a double-blind manner an infusion of 200 mg of caffeine or saline solution intravenously over one hour. A crossover took pl…
Plasma Metabolites Associated with Coffee Consumption: A Metabolomic Approach within the PREDIMED Study
2019
Few studies have examined the association of a wide range of metabolites with total and subtypes of coffee consumption. The aim of this study was to investigate associations of plasma metabolites with total, caffeinated, and decaffeinated coffee consumption. We also assessed the ability of metabolites to discriminate between coffee consumption categories. This is a cross-sectional analysis of 1664 participants from the PREDIMED study. Metabolites were semiquantitatively profiled using a multiplatform approach. Consumption of total coffee, caffeinated coffee and decaffeinated coffee was assessed by using a validated food frequency questionnaire. We assessed associations between 387 metabolit…
A cross-cultural study using Napping (R): Do Korean and French consumers perceive various green tea products differently?
2013
http://www.elsevier.com/locate/foodres ; WOS:000323239400065; International audience; With the increasing demands of global trading, interests in cross-cultural comparisons have increased to gain understanding in the differences of sensory perception and consumer acceptability. The objective of this study was to compare the differences in perception by Korean and French consumers of green tea produced in Korea, China, and Japan, using Napping (R) followed by ultra flash profile. In addition, overall acceptability was examined in both countries. The results of Napping (R) showed that the Korean consumers were able to discriminate the green teas according to their origins and processing metho…