Changes in the structure of the cuticle of Ixodes ricinus L. 1758 (Acari, Ixodidae) during feeding.

Female Ixodes ricinus (ticks) are able to consume several times as much as their own weight in food. The body volume increases without the animal moulting. Special structural and material characteristics of the cuticular exoskeleton render this phenomenon possible. Only the alloscutum, which has a very pronounced lamellar structure, extends. The individual lamellae correspond to surface folds in the outer endocuticle and the epicuticle covering it. The degree of folding is correlated to the nutritional state of the animal, which can be differentiated into three significant phases. The phase-dependent morphology of the surface structure and the cuticular layers of the alloscutum are described qualitatively and quantitatively in this paper. Furthermore, the presence of systematic deposits of resilin in the alloscutum, which are significant for the flexibility, is demonstrated.

First evidence for the use of organosilver compounds in Pd-catalyzed coupling reactions; a mechanistic rationale for the Pd/Ag-catalyzed enyne synthesis?

Silver acetylides have been prepared and used in Pd-catalyzed coupling reactions. Enynes have thus been obtained in good yields. This work demonstrates that organosilver compounds could enter the Pd catalytic cycle; it also supports the role of silver acetylides as intermediates in the new Pd/Ag-catalyzed coupling reaction.

Pharmacokinetics of iloprost in patients with severe peripheral arterial occlusive disease.

The pharmacokinetics of iloprost were studied in 12 hospitalized patients suffering from severe peripheral arterial occlusive disease (PAOD) stages III or IV according to Fontaine. The patients were 8 males and 4 females aged from 49 to 83 years. Apart from PAOD, several other concomitant diseases were present, e.g. myocardial and/or renal insufficiency, diabetes and hypertension. Patients were treated daily with i.v. infusions of iloprost at dosages of 1.0-3.3 ng/kg/min over a period of 4 to 6 h. Dose-normalized steady-state plasma levels ranged from 39 to 100 pg/ml (65 +/- 20 pg/ml). The total clearance accounted for 16 +/- 5 ml/min/kg. Post-infusion disposition in the plasma was biphasic with half-lives of 4 +/- 2 min and 37 +/- 8 min. The plasma level profiles obtained on days 4 and 14 of treatment in 3 patients were similar. Sex specific kinetic differences were not observed. In comparison to healthy volunteers, studied in an earlier trial, total clearance was slightly lower and consequently steady state levels were increased (p less than 0.05) in PAOD patients. Half-lives in the plasma were not significantly different.