Romberg extrapolation for Euler summation-based cubature on regular regions.

Romberg extrapolation is a long-known method to improve the convergence rate of the trapezoidal rule on intervals. For simple regions such as the cube [Formula: see text] it is directly transferable to cubature in q dimensions. In this paper, we formulate Romberg extrapolation for Euler summation-based cubature on arbitrary q-dimensional regular regions [Formula: see text] and derive an explicit representation for the remainder term.

Effects of cortisol administration on craving in heroin addicts.

Heroin dependence is a severe and chronically relapsing substance use disorder with limited treatment options. Stress is known to increase craving and drug-taking behavior, but it is not known whether the stress hormone cortisol mediates these stress effects or whether cortisol may rather reduce craving, for example, by interfering with addiction memory. The aim of the present study was to determine the effects of cortisol administration on craving in heroin-dependent patients and to determine whether the effects depend on the daily dose of heroin consumption. We used a double-blind, placebo-controlled, cross-over study in 29 heroin-dependent patients in a stable heroin-assisted treatment setting. A single oral dose of 20 mg of cortisol or placebo was administered 105 min before the daily heroin administration. The primary outcome measure was cortisol-induced change in craving. Secondary measures included anxiety, anger and withdrawal symptoms. For the visual analog scale for craving, we found a significant interaction (P = 0.0027) between study medication and heroin-dose group (that is, daily low, medium or high dose of heroin). Cortisol administration reduced craving in patients receiving a low dose of heroin (before heroin administration: P = 0.0019; after heroin administration: P = 0.0074), but not in patients receiving a medium or high dose of heroin. In a picture-rating task with drug-related pictures, cortisol administration did not affect the ratings for the picture-characteristic craving in all the three heroin-dose groups. Cortisol also did not significantly affect secondary outcome measures. In conclusion, a single administration of cortisol leads to reduced craving in low-dose heroin addicts. The present findings might have important clinical implications with regard to understanding stress effects and regarding treatment of addiction.

Evaluation of analytical markers characterising different drying methods of parsley leaves (Petroselinum crispum L.).

Drying process of parsley leaves from Petroselinum crispum L. can influence the sensory qualities and aromatic taste of this herbal product. Beside oven-dried material, freeze-dried parsley is getting increasingly into the market. In the course of a search for analytical tools to differentiate oven-dried and lyophilised parsley, a HPLC determination of the 6"-O-malonylapiin to apiin ratio was shown to be a suitable marker system. While the ratio is high for fresh and lyophilised leave material, oven-drying leads to demalonylation and, subsequently, to a low malonylapiin--apiin ratio. Additionally, L*a*b colour measurement can be used for quality control to differentiate between different dried parsley raw materials.

Stimulation by melittin of adrenocorticotropin and beta-endorphin release from rat adenohypophysis in vitro.

The effect of melittin on the release of adrenocorticotropin (ACTH) and beta-endorphin from the corticotropic cells of the rat adenohypophysis was examined in vitro. Anterior pituitary quarters were perifused or incubated in vitro and ACTH- (ACTH-IR) or beta-endorphin-like immunoreactivity (beta-End-IR) in the medium was measured by radioimmunoassays. Melittin stimulated ACTH-IR and beta-End-IR release. This effect was rapid in onset, reversible, and concentration-related (50-5000 ng/ml) and depended on the presence of calcium ions in the incubation medium. Melittin also elevated the tissue content of unesterified 3H-arachidonic acid that had previously been incorporated into lipids. Purported phospholipase A2 inhibitors, mepacrine (up to 1 mM), dexamethasone (0.5 mg/kg in vivo, 50 nM in vitro), or p-bromophenacylbromide (100 microM), did not decrease the melittin (500 ng/ml) - induced beta-End-IR release, although mepacrine and dexamethasone may have inhibited phospholipase A2 activity as indicated by an inhibition of melittin-evoked prostaglandin E2 formation. After stimulation by melittin (500 ng/ml), beta-End-IR release was not affected by the cyclooxygenase inhibitor indomethacin (up to 140 microM), whereas nordihydroguaiaretic acid (100 microM), a lipoxygenase inhibitor, or BW755C (250 microM), an inhibitor of both cyclooxygenase and lipoxygenase, abolished melittin-induced hormone secretion. We conclude that melittin generates a signal in the corticotropic cells of the rat adenohypophysis which induces hormone secretion by exocytosis. This signal may be unrelated to the activation by melittin of phospholipase A2.