Search

A detailed investigation of endogenous acetylcholine (ACh) release from primary embryonic septal cultures is described in this study. Applications of veratridine (25 microM) or increasing extracellular concentrations of K(+) (6-100 mM) induced robust increases of endogenous ACh release ( approximately 500-15,000 fmol/well/10 min). Release stimulated with K(+) (25 mM) was sustainable and did not differ significantly over 180 min. ACh release was dependent on extracellular choline and decreased proportionally to choline concentrations (0-10 microM). For example, after 30 min of stimulation with K(+) (25 mM), release in the absence of extracellular choline was approximately 25% of that associated with 10 microM choline. The vesicular transport blocker vesamicol (0-5 microM) almost completely prevented stimulated and basal ACh release at the highest concentration evaluated, which suggests a mostly vesicular mode of release in this model. The M(2)-like muscarinic receptor antagonist AF-DX 384 (0-10 microM) enhanced stimulated ACh release ( approximately 150% at the highest concentration evaluated), whereas the nonspecific muscarinic receptor agonist oxotremorine (0-10 microM) decreased stimulated release (approximately 60% at the highest concentration evaluated), suggesting that functional muscarinic autoreceptors exist in primary embryonic septal cultures. Novel findings concerning ACh release from primary embryonic septal cultures are reported herein, and the demonstration of ACh release gives further credit to the use of these cultures for studying cholinergic system functioning and in relation to physiology and pathology.

Raman data from human fingernails has been analysed to determine if a relationship exists between spectral features and bone quality. Previous work demonstrated a relationship between the manually determined intensity of the disulphide peak (Bone Quality Test; BQT) and osteoporotic fracture. A computer program is now described that automates the BQT determination for large sample-sets. In this study the ability of the automated BQT to discriminate between fractures and controls was compared to that of bone mineral density (BMD) and biomarkers of bone remodelling. Females aged 18–67 years participated in the study (n - 159). Fingernails were analysed using Raman spectroscopy. Lumbar and Femoral BMD was measured by dual energy X-ray absorptiometry (DXA). Fasting venepuncture samples were analysed for osteocalcin and CTx (collagen C-telopeptides) by electrochemiluminescence. No correlation was found between the BQT and BMD or the biomarkers. The BQT and BMD were found to be equally accurate in identifying subjects with a history of fracture (p < 0.01) and both outperformed osteocalcin and CTx. It appears that keratin and collagen are related structural proteins that require disulphide bonding for stability. Therefore, these preliminary results suggest that Raman spectroscopy of keratin may have potential as a diagnostic tool for screening bone quality in large populations.

The article presents a reprint of the poem "Who goes home?," by Winston Spencer Churchill, which was read on January 25 1965 on the BBC Third Programme. The poem was printed by permission of the editor of "The Listener," which was published on January 28. Moreover, the three stanza poem by Churchill is presented.