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Placebo-controlled Double-blind Study (placebo-controlled + double-blind_study)
Selected AbstractsEffects of C-peptide on forearm blood flow and brachial artery dilatation in patients with type 1 diabetes mellitusACTA PHYSIOLOGICA, Issue 3 2001E. Fernqvist-Forbes Recent studies suggest that C-peptide increases blood flow in both exercising and resting forearm in patients with type 1 diabetes. Now we have studied the effect of C-peptide administration on endothelial-mediated and non-endothelial-mediated arterial responses as well as central haemodynamics in 10 patients with type 1 diabetes in a placebo-controlled double-blind study. Euglycaemia was maintained with an i.v. insulin infusion before and during the study. A high-resolution ultrasound technique and Doppler echocardiography were used to assess haemodynamic functions. Brachial artery blood flow and brachial artery diameter were measured in the basal state, 1 and 10 min after reactive hyperaemia and 4 min after sublingual glyceryl trinitrate administration (GTN; endothelial-independent vasodilatation), both before and after the end of 60-min C-peptide (6 pmol kg,1 min,1) or saline infusion periods. Echocardiographic measurements were also performed before and at the end of the infusion periods. Seven healthy age-matched males served as controls for vascular studies. The patients showed a blunted brachial dilatation after reactive hyperaemia in comparison with the healthy controls (2.1 ± 0.5% vs. 9.3 ± 0.3%, P < 0.001), indicating a disturbed endothelial function. C-peptide infusion compared with saline resulted in increased basal blood flow (33 ± 6%, P < 0.001) and brachial arterial dilatation (4 ± 1%, P < 0.05). Left ventricular ejection fraction seemed to be improved (5 ± 2%, P < 0.05) at the end of C-peptide infusion compared with placebo. The vascular response to reactive hyperaemia and GTN was not affected by C-peptide infusion. Our results demonstrate that physiological concentrations of C-peptide increase resting forearm blood flow, brachial artery diameter and left ventricular systolic function in patients with type 1 diabetes. [source] Ginkgo biloba and donepezil: a comparison in the treatment of Alzheimer's dementia in a randomized placebo-controlled double-blind studyEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2006M. Mazza The Ginkgo biloba special extract EGb 761 seems to produce neuroprotective effects in neurodegenerative diseases of multifactorial origin. There is still debate about the efficacy of Ginkgo biloba special extract EGb 761 compared with second-generation cholinesterase inhibitors in the treatment of mild to moderate Alzheimer's dementia. Our aim is to assess the efficacy of the Ginkgo biloba special extract E.S. in patients with dementia of the Alzheimer type in slowing down the disease's degenerative progression and the patients' cognitive impairment compared with donepezil and placebo. The trial was designed as a 24-week randomized, placebo-controlled, double-blind study. Patients aged 50,80 years, suffering from mild to moderate dementia, were allocated into one of the three treatments: Ginkgo biloba (160 mg daily dose), donepezil (5 mg daily dose), or placebo group. The degree of severity of dementia was assessed by the Syndrom Kurz test and the Mini-Mental State Examination. Clinical Global Impression score was recorded to assess the change in the patients' conditions and the therapeutic efficacy of tested medications. Our results confirm the clinical efficacy of Ginkgo biloba E.S. (Flavogin) in the dementia of the Alzheimer type, comparable with donepezil clinical efficacy. There are few published trials that have directly compared a cholinesterase inhibitor with Ginkgo for dementia. This study directly compares a cholinesterase inhibitor with Ginkgo biloba for dementia of the Alzheimer type and could be a valid contribution in this debate. Our study suggests that there is no evidence of relevant differences in the efficacy of EGb 761 and donepezil in the treatment of mild to moderate Alzheimer's dementia, so the use of both substances can be justified. In addition, this study contributes to establish the efficacy and tolerability of the Ginkgo biloba special extract E.S. in the dementia of the Alzheimer type with special respect to moderately severe stages. [source] A placebo-controlled double-blind study of the efficacy of Hypericum perforatum (St John's wort) in minor depressed vs. dysthymic patientsFOCUS ON ALTERNATIVE AND COMPLEMENTARY THERAPIES AN EVIDENCE-BASED APPROACH, Issue 3 2006Article first published online: 14 JUN 2010 [source] Bright light therapy in Parkinson's disease: A pilot studyMOVEMENT DISORDERS, Issue 10 2007Sebastian Paus MD Abstract Several observations suggest a beneficial effect of melatonin antagonism for Parkinson's disease (PD). Although bright light therapy (BLT) suppresses melatonin release and is an established treatment for depression and sleep disturbances, it has not been evaluated in PD. We examined effects of BLT on motor symptoms, depression, and sleep in PD in a randomized placebo-controlled double-blind study in 36 PD patients, using Parkinson's Disease Rating Scale (UPDRS) I,IV, Beck's Depression Inventory, and Epworth Sleepiness Scale. All patients received BLT for 15 days in the morning, 30 min daily. Illuminance was 7.500 lux in the active treatment group and 950 lux in the placebo group. Although group differences were small, BLT led to significant improvement of tremor, UPDRS I, II, and IV, and depression in the active treatment group but not in the placebo group. It was very well tolerated. Follow up studies in more advanced patient populations employing longer treatment durations are warranted. © 2007 Movement Disorder Society [source] Antioxidants reverse depression of the hypoxic ventilatory response by acetazolamide in manTHE JOURNAL OF PHYSIOLOGY, Issue 3 2006Luc J. Teppema The carbonic anhydrase inhibitor acetazolamide may have both inhibitory and stimulatory effects on breathing. In this placebo-controlled double-blind study we measured the effect of an intravenous dose (4 mg kg,1) of this agent on the acute isocapnic hypoxic ventilatory response in 16 healthy volunteers (haemoglobin oxygen saturation 83,85%) and examined whether its inhibitory effects on this response could be reversed by antioxidants (1 g ascorbic acid i.v. and 200 mg ,-tocopherol p.o.). The subjects were randomly divided into an antioxidant (Aox) and placebo group. In the Aox group, acetazolamide reduced the mean normocapnic and hypercapnic hypoxic responses by 37% (P < 0.01) and 55% (P < 0.01), respectively, and abolished the O2,CO2 interaction, i.e. the increase in O2 sensitivity with rising PCO2. Antioxidants completely reversed this inhibiting effect on the normocapnic hypoxic response, while in hypercapnia the reversal was partial. In the placebo group, acetazolamide reduced the normo- and hypercapnic hypoxic responses by 33 and 47%, respectively (P < 0.01 versus control in both cases), and also abolished the O2,CO2 interaction. Placebo failed to reverse these inhibitory effects of acetazolamide in this group. We hypothesize that either an isoform of carbonic anhydrase may be involved in the regulation of the redox state in the carotid bodies or that acetazolamide and antioxidants exert independent effects on oxygen-sensing cells, in which both carbonic anhydrase and potassium channels may be involved. The novel findings of this study may have clinical implications, for example with regard to a combined use of acetazolamide and antioxidants at high altitude. [source] | |||||||||||||