Selective serotonin 5-HT1A receptor biased agonists elicitdistinct brain activation patterns: a pharmacoMRI study

Serotonin 1A (5-HT1A) receptors are involved in several physiological and pathological processes and constitute therefore an important therapeutic target. The recent pharmacological concept of biased agonism asserts that highly selective agonists can preferentially direct receptor signaling to specific intracellular responses, opening the possibility of drugs targeting a receptor subtype in specific brain regions. The present study brings additional support to this concept thanks to functional magnetic resonance imaging (7 Tesla-fMRI) in anaesthetized rats. Three 5-HT1A receptor agonists (8-OH-DPAT, F13714 and F15599) and one 5-HT1A receptor antagonist (MPPF) were compared in terms of influence on the brain blood oxygen level-dependent (BOLD) signal. Our study revealed for the first time contrasting BOLD signal patterns of biased agonists in comparison to a classical agonist and a silent antagonist. By providing functional information on the influence of pharmacological activation of 5-HT1A receptors in specific brain regions, this neuroimaging approach, translatable to the clinic, promises to be useful in exploring the new concept of biased agonism in neuropsychopharmacology.

Frequency of damage by external explosion hazards based on geographical information

External explosions can significantly contribute to risk of damage for industrial plants. External explosions may origin from other plants in the neighbourhood, which store and operate with explosive substances, or from transport of such substances on road, rail, or water. If deflagration is involved, ignition will not necessarily occur at the place of the accident, but a cloud of a combustible gas-air mixture may develop, which will ignite at some distance depending on wind velocity. A probabilistic model has been developed to calculate frequencies of damage based on numerical integration or on Monte Carlo simulation. Geographical information systems provide map material for sites, roads, rail and rivers on a computer. Data has been collected and applied for a nuclear power plant in Germany as an example. The method, however, can be used for any type of plant subject to external explosion hazards.

Ethnicity and lupus nephritis: an Australian single centre study

BACKGROUND

The clinical impression of Australian physicians is that systemic lupus erythematosus (SLE) is more prevalent and more severe in Asian patients than in their Caucasian counterparts. The presence and severity of lupus nephritis is a major determinant of prognosis in SLE, and largely determines disease impact.

AIM

To analyse the relationships between ethnicity and the prevalence and severity of lupus nephritis (LN) in patients attending a tertiary referral centre (The Royal Melbourne Hospital (RMH)).

METHODS

The ethnicity of all known patients with biopsy-proven LN was determined according to three definitions of ethnicity - ancestry, country of origin and primary language spoken. The prevalence of Asian ethnicity in the LN cohort was analysed across severity class, and was compared with the prevalences of Asian ethnicity in the general population within the hospital's geographic area, and with that in the relevant RMH cohorts of inpatients and outpatients, over the same time period.

RESULTS

Within this single tertiary centre, Asian patients were disproportionately represented in both the systemic lupus erythematosus (SLE) and the LN patient groups, although the distribution of histological severity of LN was not significantly different from Caucasian patients.

CONCLUSION

This study supports the common clinical impression that SLE is more common and more severe in the Asian-Australian population. Asian patients with SLE were more commonly diagnosed with LN. However, the spectrum of histological severity of LN was similar in Asian and Caucasian patients.