Search results for "Cross-Over Studies"

Influence of St John's wort on catecholamine turnover and cardiovascular regulation in humans

2004

BACKGROUND: St John's wort (Hypericum perforatum) is a popular over-the-counter antidepressant. Its antidepressive effect has been attributed in part to inhibition of monoamine transporters and monoamine oxidase, on the basis of in vitro studies. METHODS: In a double-blind, randomized, placebo-controlled, crossover study, 16 healthy subjects (11 men and 5 women; mean age, 31 +/- 5 years) ingested either St John's wort (300 mg three times daily) or placebo for 7 days. Imipramine treatment (50 mg three times daily) in 7 subjects served as a positive control. After treatment, physiologic and biochemical tests included cardiovascular reflex testing, graded head-up tilt testing, and plasma catec…

The effects of an amine fluoride/stannous fluoride and an antimicrobial host protein mouthrinse on supragingival plaque regrowth.

2004

BACKGROUND: Chlorhexidine (CHX)-containing mouthrinses are recommended as adjuncts to mechanical oral hygiene. The problem associated with side effects, however, has stimulated the search for alternative antiplaque agents. The aim of this study was to investigate the plaque inhibitory effects of two mouthrinses containing amine fluoride/stannous fluoride (ASF) and antimicrobial host proteins (lactoperoxidase, lysozyme and lactoferrin; LLL), respectively. METHODS: The study was an observer-masked, randomized 4x4 Latin square cross-over design balanced for carryover effects, involving 12 healthy volunteers in a 4-day plaque regrowth model. A 0.12% CHX mouthrinse and a saline solution served a…

The effect of olive oil polyphenols on antibodies against oxidized LDL. A randomized clinical trial

2010

summary Background & aim: Oxidized LDL (oxLDL) is a highly immunogenic particle that plays a key role in the development of atherosclerosis. Some data suggest a protective role of OxLDL autoantibodies (OLAB) in atherosclerosis. Our aim was to assess the effect of olive oil polyphenols on the immunogenicity of oxLDL to autoantibody generation. Methods: In a crossover, controlled trial, 200 healthy men were randomly assigned to 3-week sequences of 25 mL/day of 3 olive oils with high (366 mg/kg), medium (164 mg/kg), and low (2.7 mg/kg) phenolic content. Results: Plasma OLAB concentration was inversely associated with oxLDL (p < 0.001). Olive oil phenolic content increased OLAB generation, with…

Effects of the NMDA-receptor antagonist ketamine on perceptual correlates of long-term potentiation within the nociceptive system

2007

We recently reported perceptual correlates of long-term potentiation (LTP) of synaptic strength within the nociceptive system demonstrating the functional relevance of LTP for human pain sensation. LTP is generally classified as NMDA-receptor dependent or independent. Here we show that low doses of the NMDA-receptor antagonist ketamine (0.25 mg/kg) prevented the long-term increase in perceived pain to electrical test stimuli, which was induced by high-frequency electrical stimulation (HFS) of nociceptive afferents. Whereas in a control experiment HFS led to a stable increase in perceived pain by 51% for the entire observation period of 1 h HFS given 4 min after i.v. ketamine was ineffective…

Zolmitriptan inhibits neurogenic inflammation and pain during electrical stimulation in human skin.

2014

Background Triptans are agonists to 5-HT 1B/D/F receptors, which are present on nociceptive neurons not only within but also beyond the trigeminal system. The aim of this study was to investigate whether zolmitriptan interacts with peptidergic nociceptive afferents in human skin. Methods Twenty participants (13 women, median age: 25; interquartile range: 23–26 years) entered the randomized, double-blind, cross-over study. Electrically induced neurogenic flare and pain was assessed after either placebo or zolmitriptan on the ventral thigh. Mechanical pain thresholds were investigated at baseline and after electrical stimulation at the stimulation site. Results The size of the neurogenic flar…

Activation of the cortical pain network by soft tactile stimulation after injection of sumatriptan.

2006

The anti-migraine drug sumatriptan often induces unpleasant somatosensory side effects, including a dislike of being touched. With a double-blind cross-over design, we studied the effects of sumatriptan and saline on perception (visual analogue scale) and cortical processing (functional magnetic resonance imaging) of tactile stimulation in healthy subjects. Soft brush stroking on the calf (n = 6) was less pleasant (p < 0.04) and evoked less activation of posterior insular cortex in the sumatriptan compared to the saline condition. Soft brushing activated pain processing regions (anterior insular, lateral orbitofrontal, and anterior cingulate cortices, and medial thalamus) only in the sumatr…

Acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects.

2013

Abstract The German MAK value of 1-methoxypropanol-2 has been fixed at 100 ppm. The aim of this study was to evaluate possible acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects. Twenty subjects were exposed in a crossover design to 100 ppm 1-methoxypropanol-2 and to air in an exposure chamber for 4 h. Subjective symptoms were assessed by questionnaire. Olfactory thresholds for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1β and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1β, 6 and 8, tumor necrosis factor α, granulocyte-m…

Effects of hawthorn (Crataegus laevigata) on platelet aggregation in healthy volunteers

2011

Tiotropium Respimat® in asthma: a double-blind, randomised, dose-ranging study in adult patients with moderate asthma

2013

Tiotropium, a once-daily long-acting anticholinergic bronchodilator, when administered via Respimat® SoftMist™ inhaler (tiotropium Respimat®) significantly reduces the risk of severe exacerbations and improves lung function in patients with severe persistent asthma that is not fully controlled despite using inhaled corticosteroids (ICS) and long-acting β2-agonists. To further explore the dose–response curve in asthma, we investigated the efficacy and safety of three different doses of tiotropium Respimat® as add-on to ICS in symptomatic patients with moderate persistent asthma. In this randomised, double-blind, placebo-controlled, four-way crossover study, patients were randomised to tiotro…

The effect of challenge method on methacholine-induced changes in sensitivity and air trapping

2010

Summary Background The methacholine challenge test performed with the tidal breathing method induces a greater fall in FEV 1 than the dosimeter method; however, the effect of the challenge method on methacholine-induced fall in FVC has not been investigated. Objective To determine the influence of the challenge method on methacholine-induced changes in FEV 1 and FVC. Methods Airway responsiveness to methacholine was determined by dosimeter method and tidal breathing method in 37 subjects with suspected asthma. The dosimeter was modified to deliver an identical volume to that obtained with the tidal breathing method and the same nebulizer model was used for the two challenges. The response w…