A 3D QSAR study of monoamino oxidase-B inhibitors using the chemical function based pharmacophore generation approach

A molecular modelling study was performed using the CATALYST software package on a dataset of 100 thiosemicarbazide and thiazole derivatives acting as MAO-B irreversible inhibitors in order to, (i) better elucidate the possible role of the ligand features which are significant for binding and (ii) generate chemical features based pharmacophore models which were subsequently used as 3D queries for database searching. Based on known MAO-B inhibitors, pharmacophore hypotheses were created in order to find similarities between the thiazoles and thiosemicarbazides and identify the key sub-structures most likely to be significant for high MAO-B inhibitory activity.

Intravenous versus oral administration of amitriptyline in patients with major depression

Antidepressants can be administered by different routes. Advantages for either the oral or the intravenous administration have been suggested from pharmacokinetic as well as from clinical points of view. Controlled comparison studies of the two routes do not provide unequivocal recommendations. In this investigation, amitriptyline was studied over a 4-week period consisting of a 2-week, double-blind/double-dummy phase with either oral (150 mg/day), high-dose intravenous (150 mg/day), or medium-dose intravenous (100 mg/day) treatment and a 2-week phase of open oral treatment in 80 patients with major depression. A psychopathologic assessment was made using the Hamilton Rating Scale for Depression, the Clinical Global Impressions Scale, the von Zerssen's "Befindlichkeitsskala," an adjective checklist, and a Visual Analog Scale. No significant differences were found concerning the mean scores of the rating scales or time of onset of action in the physicians' ratings. In the patients' self-ratings, there was an earlier therapeutic effect in the high-dose intravenous group. The number of improvers after 7 days was significantly higher in the high-dose intravenous group compared with both other groups. After 14 days, no significant differences in the numbers of improvers and responders between groups were detected. The results of this study do not clearly favor one of the tested options. The main differences found in this study seem to be dose-related rather than differentiating between oral and intravenous routes of administration.

Engineered fusion molecules at chelator lipid interfaces imaged by reflection interference contrast microscopy (RICM)

In molecular biology, biotechnology, and protein-engineering, the expression of histidine fusion proteins is a very powerful technique for the identification and one-step purification based on the interaction of the histidine stretch with immobilized metal complexes. By synthesis of a novel class of chelator lipids, this technique was combined with the concept of self-assembly leading to interfaces for immobilization and orientation of histidine-tagged biomolecules (Schmitt et al., 1994). Here, the chelator lipid layers were transferred onto solid substrate by vesicle fusion and Langmuir-Blodgett-techniques. Specific binding of a peptide containing an oligohistidine sequence to these functionalized interfaces was demonstrated by reflection interference contrast microscopy (RICM). Due to the phase separation behaviour of lipid mixtures, the chelator lipid interface could be further structured in two dimensions. Binding and organization of histidine-tagged molecules at these two-dimensional recognition arrays was imaged by RICM with a layer thickness resolution of 0.2 nm, and 0.5 microm laterally. Specific docking can be triggered by adding nickel ions and disrupted by EDTA. This concept opens up possibilities for reversible immobilization, enrichment and organization of histidine fusion proteins at interfaces and their application in biosensing.

Smoking cessation--gradual or sudden stopping?

One hundred ten patients addicted to nicotine were subjected to either sudden or gradual withdrawal in the course of a smoking cessation programme. Eighty-two patients emerged from the treatment as non-smokers. In a follow-up after 1 year 70% of these successful clients replied to an anonymous questionnaire. Concerning the relapse rate, no significant difference could be found between the two treatment groups, but patients who underwent slow withdrawal smoked significantly less when comparing their current consumption with that before the start of the therapy. Patients who underwent sudden stopping reached their original level of nicotine use again.