774 resultados para Placebo
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OBJECTIVES: The aim of this single-blind randomized crossover study was to evaluate specific effects of manual acupuncture on central and vegetative nervous system activity measured by quantitative electroencephalography (qEEG) and heart rate variability (HRV). DESIGN: Twenty (20) healthy volunteers (mean: 25.2 +/- 3.6 years) were monitored simultaneously using a qEEG system and a 12-channel electrocardiogram recorder during verum acupuncture (VA) at acupuncture point Large Intestine 4 (Hegu) (LI4) or placebo acupuncture (PA) at a sham point. RESULTS: In the EEG conduction of the occipital area, needle stimulation in VA increased alpha1-frequency significantly, and the ratio alpha1/theta was shifted to the benefit of alpha1 over all electrodes. The HRV parameters showed a significant increase of the low frequency/high frequency (HF) ratio during the first minute of stimulation in VA, indicating an initial increase of sympathetic activation. However, an increase of HF power in the minute after stimulation followed by a decrease in heart rate suggests delayed vagal activation. De qi (a sensation that is typical of acupuncture needling) occurred in 16 subjects during VA and in 9 volunteers during PA (80% versus 45%). CONCLUSIONS: Manual stimulation on LI4 seems to lead to specific changes in alpha EEG-frequency and in HRV parameters. A linear relationship between the HRV parameters and the alpha EEG band might point to a specific modulation of cerebral function by vegetative effects during acupuncture.
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BACKGROUND: Constipation is a significant side effect of opioid therapy. We have previously demonstrated that naloxone-3-glucuronide (NX3G) antagonizes the motility-lowering-effect of morphine in the rat colon. AIM: To find out whether oral NX3G is able to reduce the morphine-induced delay in colonic transit time (CTT) without being absorbed and influencing the analgesic effect. METHODS: Fifteen male volunteers were included. Pharmacokinetics: after oral administration of 0.16 mg/kg NX3G, blood samples were collected over a 6-h period. Pharmacodynamics: NX3G or placebo was then given at the start time and every 4 h thereafter. Morphine (0.05 mg/kg) or placebo was injected s.c. 2 h after starting and thereafter every 6 h for 24 h. CTT was measured over a 48-h period by scintigraphy. Pressure pain threshold tests were performed. RESULTS: Neither NX3G nor naloxone was detected in the venous blood. The slowest transit time was observed during the morphine phase, which was significantly different from morphine with NX3G and placebo. The pain perception was not significantly influenced by NX3G. CONCLUSIONS: Orally administered NX3G is able to reverse the morphine-induced delay of CTT in humans without being detected in peripheral blood samples. Therefore, NX3G may improve symptoms of constipation in-patients using opioid medication without affecting opioid-analgesic effects.
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The vitamin E compound alpha-tocopherol inhibits fibroblast growth in vitro. To evaluate its potential benefit in preventing failure of glaucoma filtration surgery, we prospectively investigated the outcome of filtering surgery with postoperative dietary alpha-tocopherol supplementation.
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Activity of clotting factor VIII has been shown to acutely increase with sympathetic nervous system stimulation. We investigated whether aspirin and propranolol affect the responsiveness of plasma clotting factor VIII activity levels to acute psychosocial stress. We randomized 54 healthy subjects double-blind to 5-day treatment with a single daily oral dosage of either 100 mg aspirin plus 80 mg propranolol combined, 100 mg of aspirin, 80 mg of propranolol, or placebo medication. Thereafter, subjects underwent a 13-min standardized psychosocial stressor. Plasma levels of clotting factor VIII activity were determined immediately before, immediately after, 45 min and 105 min after stress. Controlling for demographic, metabolic, and life style factors repeated measures analysis of covariance showed that the change in clotting factor VIII activity from prestress to 105 min poststress differed between medication groups (P = 0.023; partial eta = 0.132). The clotting factor VIII activity level decreased from prestress to immediately poststress in the aspirin/propranolol group relative to the placebo group (P = 0.048) and the aspirin group (P < 0.06). Between 45 min and 105 min poststress, clotting factor VIII levels increased in the aspirin/propranolol group relative to the placebo group (P = 0.007) and the aspirin group (P = 0.039). The stress response in clotting factor VIII activity levels was not significantly different between the aspirin/propranolol group and the propranolol group. Propranolol in combination with aspirin diminished the acute response in clotting factor VIII activity to psychosocial stress compared with placebo medication and aspirin alone. The effect of single aspirin on the acute clotting factor VIII stress response was indistinguishable from a placebo effect.
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Acute mental stress is a potent trigger of acute coronary syndromes. Catecholamine-induced hypercoagulability with acute stress contributes to thrombus growth after coronary plaque rupture. Melatonin may diminish catecholamine activity. We hypothesized that melatonin mitigates the acute procoagulant stress response and that this effect is accompanied by a decrease in the stress-induced catecholamine surge. Forty-five healthy young men received a single oral dose of either 3 mg melatonin (n = 24) or placebo medication (n = 21). One hour thereafter, they underwent a standardized short-term psychosocial stressor. Plasma levels of clotting factor VII activity (FVII:C), FVIII:C, fibrinogen, D-dimer, and catecholamines were measured at rest, immediately after stress, and 20 min and 60 min post-stress. The integrated change in D-dimer levels from rest to 60 min post-stress differed between medication groups controlling for demographic and metabolic factors (P = 0.047, eta(p)(2) = 0.195). Compared with the melatonin group, the placebo group showed a greater increase in absolute D-dimer levels from rest to immediately post-stress (P = 0.13; eta(p)(2) = 0.060) and significant recovery of D-dimer levels from immediately post-stress to 60 min thereafter (P = 0.007; eta(p)(2) = 0.174). Stress-induced changes in FVII:C, FVIII:C, fibrinogen, and catecholamines did not significantly differ between groups. Oral melatonin attenuated the stress-induced elevation in the sensitive coagulation activation marker D-dimer without affecting catecholamine activity. The finding provides preliminary support for a protective effect of melatonin in reducing the atherothrombotic risk with acute mental stress.
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Melatonin has previously been suggested to affect hemostatic function but studies on the issue are scant. We hypothesized that, in humans, oral administration of melatonin is associated with decreased plasma levels of procoagulant hemostatic measures compared with placebo medication and that plasma melatonin concentration shows an inverse association with procoagulant measures. Forty-six healthy men (mean age 25 +/- 4 yr) were randomized, single-blinded, to either 3 mg of oral melatonin (n = 25) or placebo medication (n = 21). One hour thereafter, levels of melatonin, fibrinogen, and D-dimer as well as activities of coagulation factor VII (FVII:C) and VIII (FVIII:C) were measured in plasma. Multivariate analysis of covariance and regression analysis controlled for age, body mass index, mean arterial blood pressure, heart rate, and norepinephrine plasma level. Subjects on melatonin had significantly lower mean levels of FVIII:C (81%, 95% CI 71-92 versus 103%, 95% CI 90-119; P = 0.018) and of fibrinogen (1.92 g/L, 95% CI 1.76-2.08 versus 2.26 g/L, 95% CI 2.09-2.43; P = 0.007) than those on placebo explaining 14 and 17% of the respective variance. In all subjects, increased plasma melatonin concentration independently predicted lower levels of FVIII:C (P = 0.037) and fibrinogen (P = 0.022) explaining 9 and 11% of the respective variance. Melatonin medication and plasma concentration were not significantly associated with FVII:C and D-dimer levels. A single dose of oral melatonin was associated with lower plasma levels of procoagulant factors 60 min later. There might be a dose-response relationship between the plasma concentration of melatonin and coagulation activity.
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Psychosocial stress might increase the risk of atherothrombotic events by setting off an elevation in circulating levels of the proinflammatory cytokine interleukin (IL)-6. We investigated the effect of aspirin and propranolol on the responsiveness of plasma IL-6 levels to acute psychosocial stress. For 5 days, 64 healthy subjects were randomized, double-blind, to daily oral aspirin 100mg plus long-acting propranolol 80 mg, aspirin 100mg plus placebo, long-acting propranolol 80 mg plus placebo, or placebo plus placebo. Thereafter, all subjects underwent the 13-min Trier Social Stress Test, which combines a preparation phase, a job interview, and a mental arithmetic task. Plasma IL-6 levels were measured in blood samples collected immediately pre- and post-stress, and 45 min and 105 min thereafter. The change in IL-6 from pre-stress to 105 min post-stress differed between subjects with aspirin medication and those without (p =0.033; eta p2=0.059). IL-6 levels increased less from pre-stress to 105 min post-stress (p <0.027) and were lower (p =0.010) at 105 min post-stress in subjects with aspirin than in subjects without aspirin. The significance of these results was maintained when controlling for gender, age, waist-to-hip ratio, mean arterial blood pressure, and smoking status. Medication with propranolol was not significantly associated with the stress-induced change in IL-6 levels. Also, aspirin and propranolol did not significantly interact in determining the IL-6 stress response. Aspirin but not propranolol attenuated the stress-induced increase in plasma IL-6 levels. This suggests one mechanism by which aspirin treatment might reduce the risk of atherothrombotic events triggered by acute mental stress.
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OBJECTIVES: Dental erosion, the chemical dissolution of enamel without bacterial involvement, is a rarely reported manifestation of gastroesophageal reflux disease (GERD), as well as of recurrent vomiting and dietary habits. It leads to loss of tooth substance, hypersensitivity, functional impairment, and even tooth fracture. To date, dental erosions have been assessed using only very basic visual methods, and no evidence-based guidelines or studies exist regarding the prevention or treatment of GERD-related dental erosions. METHODS: In this randomized, double-blind study, we used optical coherence tomography (OCT) to quantify dental tissue demineralization and enamel loss before and after 3 weeks of acid-suppressive treatment with esomeprazole 20 mg b.i.d. or placebo in 30 patients presenting to the Berne University Dental Clinic with advanced dental erosions and abnormal acid exposure by 24-h esophageal pH manometry (defined as >4% of the 24-h period with pH<4). Enamel thickness, reflectivity, and absorbance as measures of demineralization were quantified by OCT before and after therapy at identical localizations on teeth with most severe visible erosions as well as several other predefined changes in teeth. RESULTS: The mean+/-s.e.m. decrease of enamel thickness of all teeth before and after treatment at the site of maximum exposure was 7.2+/-0.16 black trianglem with esomeprazole and 15.25+/-0.17black trianglem with placebo (P=0.013), representing a loss of 0.3% and 0.8% of the total enamel thickness, respectively. The change in optical reflectivity to a depth of 25 black trianglem after treatment was-1.122 +/-0.769 dB with esomeprazole and +2.059+/-0.534 dB with placebo (P 0.012), with increased reflectivity signifying demineralization. CONCLUSIONS: OCT non-invasively detected and quantified significantly diminished progression of dental tissue demineralization and enamel loss after only 3 weeks of treatment with esomeprazole 20 mg b.i.d. vs. placebo. This suggests that esomeprazole may be useful in counteracting progression of GERD-related dental erosions. Further validation of preventative treatment regimens using this sensitive detection method is required, including longer follow-up and correlation with quantitative reflux measures.
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OBJECTIVE: To evaluate whether intravaginal application of seminal plasma at the time of follicle aspiration in IVF or intracytoplasmic sperm injection treatment cycles has the potential to increase pregnancy rate. To calculate the number of patients needed to achieve significance in a multicenter trial. DESIGN: Double-blind, placebo-controlled randomized pilot study. SETTING: University department of gynecological endocrinology and reproductive medicine. PATIENT(S): One hundred sixty-eight patients undergoing IVF or intracytoplasmic sperm injection treatment. INTERVENTION(S): Cryopreserved seminal plasma from the patient's partner or sodium chloride (placebo) was injected into the cervix and the posterior fornix of the vagina just after follicle aspiration. MAIN OUTCOME MEASURE(S): Clinical-pregnancy rate. RESULT(S): One hundred sixty-eight patients agreed to participate in the study. Participation was limited to one treatment cycle. Thirty-one patients (18%) were excluded from the study, mainly as a result of canceled embryo transfers. Seventy patients received placebo, and 67 received seminal plasma. The clinical-pregnancy rate was 25.7% (18/70) in the placebo group. The clinical-pregnancy rate in the seminal plasma group reached 37.3% (25/67), corresponding to a relative increase of 45%. CONCLUSION(S): Even though significance was not reached in this pilot study, the data suggest that seminal plasma has the potential to improve pregnancy rate. It is estimated that around 450 patients need to be recruited to reach significance in a multicenter study.
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Patients with adult GH-deficiency are thought to have an increased risk of cardiovascular disease. Sialic acid (SA) concentrations have been proposed as a marker of atherosclerotic disease probably related to an inflammatory response of the arterial wall. SA as a marker of cardiovascular disease in adult GH-deficiency and its relation to changes in fasting lipid profile and hormone concentrations have not yet been investigated.
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A randomised, placebo-controlled, double blind study was conducted on 25 dogs that had atopic dermatitis, together with skin test reactivity and elevated serum IgE to Dermatophagoides farinae (Df) and at least one additional allergen. Dogs were treated with either a Df-restricted immunotherapy solution (n=14) or a placebo (n=11) and evaluated 6 weeks and 3, 5, 7 and 9 months after the initiation of treatment using a clinical scoring system (SASSAD) and pruritus analogue scale scores. The Df-restricted solution and the placebo had an equal effect on both pruritus and the skin manifestations (P>0.05). The results of this study indicate that in dogs with atopic dermatitis based on hypersensitivity to environmental allergens in addition to D. farinae, Df-restricted immunotherapy is insufficient to control the disease. Consequently, a solution for allergen-specific immunotherapy should remain customised.