Typical investigational medicinal products follow relatively uniform regulations in 10 European Clinical Research Infrastructures Network (ECRIN) countries.

Background: In order to facilitate multinational clinical research, regulatory requirements need to become international and harmonised. The EU introduced the Directive 2001/20/EC in 2004, regulating investigational medicinal products in Europe.

Methods: We conducted a survey in order to identify the national regulatory requirements for major categories of clinical research in ten European Clinical Research Infrastructures Network (ECRIN) countries-Austria, Denmark, France, Germany, Hungary, Ireland, Italy, Spain, Sweden, and United Kingdom-covering approximately 70% of the EU population.

Compassionate use of interventions: results of a European Clinical Research Infrastructures Network (ECRIN) survey of ten European countries.

Background: 'Compassionate use' programmes allow medicinal products that are not authorised, but are in the development process, to be made available to patients with a severe disease who have no other satisfactory treatment available to them. We sought to understand how such programmes are regulated in ten European Union countries.

Methods: The European Clinical Research Infrastructures Network (ECRIN) conducted a comprehensive survey on clinical research regulatory requirements, including questions on regulations of 'compassionate use' programmes.

Common definition for categories of clinical research: a prerequisite for a survey on regulatory requirements by the European Clinical Research Infrastructures Network (ECRIN).

Background: Thorough knowledge of the regulatory requirements is a challenging prerequisite for conducting multinational clinical studies in Europe given their complexity and heterogeneity in regulation and perception across the EU member states.

Methods: In order to summarise the current situation in relation to the wide spectrum of clinical research, the European Clinical Research Infrastructures Network (ECRIN) developed a multinational survey in ten European countries. However a lack of common classification framework for major categories of clinical research was identified, and therefore reaching an agreement on a common classification was the initial step in the development of the survey.

Role of nitric oxide in choroidal blood flow regulation during light/dark transitions.

Purpose: Several studies have recently shown that a transition from light to dark is associated with a reduction in choroidal blood flow. The mechanism underlying this effect is unclear but may be related to changes in neural input. In the present study, the authors hypothesized that either the alpha-receptor agonist phenylephrine or the nitric oxide synthase (NOS) inhibitor L-NMMA may alter the choroidal blood flow response during a transition from light to dark.

Effects of dopamine on retinal and choroidal blood flow parameters in humans.

Aim: To investigate the effect of dopamine on retinal and choroidal blood flow in humans.

Methods: We investigated the effect of two doses of intravenous dopamine (5 and 10 microg/kg/min) via a randomised double-masked crossover study in 12 healthy subjects chosen from a total of 16. Blood flow parameters in retina, optic nerve head and choroid were assessed with bi-directional laser Doppler velocimetry, laser Doppler flowmetry and laser interferometric measurement of fundus pulsation amplitude, respectively.

Flicker light-induced vasodilatation in the human retina: effect of lactate and changes in mean arterial pressure.

Purpose: Diffuse luminance flicker light increases retinal and optic nerve head blood flow in animals and humans, but the exact mechanisms that mediate increased flow have yet to be identified. In the current study, the effect of increased plasma lactate levels on flicker-induced vasodilatation in the retina was investigated in three independent studies in healthy humans.

Methods: In the first study, plasma lactate concentrations were increased by bicycle exercise in 12 volunteers, and the change in retinal vessel diameter to 8-Hz square-wave flicker stimulation was measured with the Zeiss Retinal Vessel Analyzer (Carl Zeiss Meditec, Oberkochen, Germany).

Effects of adrenomedullin on ocular hemodynamic parameters in the choroid and the ophthalmic artery.

Purpose: Adrenomedullin acts as a vasodilator and may play a role in inflammatory processes in the eye. This study was designed to determine whether nitric oxide formation is involved in the response to adrenomedullin in the ocular vasculature in vivo.

Methods: The effects of systemic intravenous adrenomedullin (3.

Effects of dopamine on human retinal vessel diameter and its modulation during flicker stimulation.

We performed a randomized, subject-blinded, placebo and time-controlled, two-way crossover study in 12 healthy male subjects. Placebo or dopamine was administered on two separate study days. After saline infusion, dopamine hydrochloride was infused in three consecutive doses (5, 10, and 15 microg x kg(-1) x min(-1)).