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The synthesis of new urea-bridged a-Cycodextrin dimers (CDs) has been successfully achieved by a one-pot transformation of 6-monoazido-6-monodeoxy-ß-CDs (1 and 2)via the phosphinimines. Pseudo-first-order rate constants for hydrolysis of bis-(p-nitrophenyl)-phosphate (BNPP) by metal-complexes of 7 have been measured.

Simultaneous binding of two sequential glycolytic enzymes, phosphofructokinase and aldolase, to a microtubular network was investigated. The binding of the phosphofructokinase to microtubules and its bundling activity has been previously characterized (Lehotzky, A., Telegdi, M., Liliom, K., and Ovádi, J. (1993) J. Biol. Chem. 268, 10888-10894). Aldolase binding to microtubules at near physiological ionic strength is weak (Kd = 20 microM) as compared with that of the kinase (Kd = 1 microM). The interactions of both enzymes with microtubules are modulated by their common intermediate, fructose-1,6-bisphosphate. Pelleting and electron microscopic measurements have revealed that the aldolase binding interferes with that of phosphofructokinase, although they have distinct binding domains on microtubules. The underlying molecular mechanism responsible for this finding is that in the solution phase aldolase and phosphofructokinase form a bienzyme complex that does not bind to the microtubule. The bienzyme complex formation does not influence the catalytic activity of aldolase, however, it inhibits the dissociation-induced inactivation of the kinase by stabilizing a catalytically active molecular form. The present data suggest the first experimental evidence that two sequential glycolytic enzymes do not associate simultaneously to microtubules, but their complexation in solution provides kinetic advantage for glycolysis.

The effects of three α2 adrenoceptor blockers (idazoxan, yohimbine and CH-38083) on isolation-induced aggressive behavior was studied in male mice. The three drugs produced different behavioral profiles. Idazoxan reduced aggressiveness dose-dependently by decreasing the duration of offensive/aggressive interactions and increasing the duration of defensive behaviors. The other two drugs produced only parts of the dual action of idazoxan: yohimbine affected mainly defensive behaviors, while CH-38083 affected only the time spent with fighting. Saline injections per se also influenced behavior and, in contrast to α2 adrenoceptor blockers, induced an increase in aggressiveness. These results are different from those previously obtained in rats, which show bell-shaped dose-response curves in response to α2 adrenoceptor blockers (small doses increased, while large doses decreased aggression). It is postulated that the strong behavioral reaction of mice to the injection per se may mask the aggression-heightening effects of small doses of α2 adrenoceptor blockers in this species. A theory is also presented regarding the complexity of adrenoceptor interactions when both pre-, and postsynaptic α2 adrenoceptors are blocked.

The effects of adrenergic activation on aggressiveness and the aggression induced endocrine changes were tested in rats. α2 adrenoceptor blockers were used for enhancing activation of the adrenergic system, and changes in aggressiveness were tested in resident-intruder contests. Three experiments were conducted. In experiment 1, saline injected rats responded to the presence of an opponent by aggression and the increase in plasma ACTH and corticosterone. Intraperitoneal administration of 1 mg/kg CH-38083 (an α2 adrenoceptor antagonist) produced a several fold increase in clinch fighting and mutual upright scores, and also further enhanced the plasma ACTH and corticosterone response. In experiment 2, the effect of three doses (0.5, 1 and 2 mg/kg) of three different α2 adrenoceptor blockers CH-38083, idazoxan and yohimbine were tested. All the substances increased aggression at 0.5 and 1 mg/kg; at 2 mg/kg the effect of idazoxan and yohimbine disappeared, while with CH-38083 an additional increase was obtained. In yohimbine treated animals the enhancement of aggression was reduced already at 1 mg/kg. In experiment 3, indomethacin, a potent inhibitor of the catecholamine-induced ACTH release completely abolished the effects of the α2 adrenoceptor antagonist CH-38083: the intensity of agonistic interactions, as well as ACTH and corticosterone plasma concentrations, returned to control levels. The possible role of catecholamines and the stress hormones in the activation of aggression is discussed.

Abstract: A method is described for the determination of89Sr and90Sr in samples of plant and animal origin. The Rehak-Feddersen method was modified to measure90Sr. Modification was made in the sample preparation and in the toluene-HDEHP [di(2-ethylhexyl)phosphoric acid] extraction. After the extraction of yttrium, strontium is separated with nitric acid and—calculating with a correction factor—89Sr can directly be determined. Namely,89Sr can be measured in an aqueous solution by a liquid scintillation technique with an efficiency of 30% while90Sr with 1.4% only. Quenching of the solution—depending on the composition—which may influence the measurement of90Y and89Sr was also examined. Detection limits and reproducibilities are given. Finally, evaluation of the experimental data is reported.

Phosphomonoesterase-Aktivitäten in Normalseren und in denen von M.S.-Kranken wurden gleichzeitig auf das Vorhandensein von Hemm- bzw. Aktivator-Effekten gegen gereinigte oder konzentrierte, natürliche Enzyme untersucht. Saure, resp. alkalische Phosphatase und 5-Nukleotidase wurde in Serumgroßpoolen von gesunden Menschen (über 600 Einzelseren beider Geschlechter, im Alter von 20 bis 65 Jahren) bestimmt, gleichzeitig auch die spezifischen Einflüsse der Seren auf gereinigte pflanzliche saure und tierische alkalische Phosphatase, bzw. die 5-Nukleotidase von lyophilisierten Schlangengiften. Die Großpoole beider Gruppen, getrennt nach Geschlechtern, zeigten einen ermäßigten Spiegel der gewöhnlichen Phosphomonoesterasen, die 5-Nukleotidase Aktivitäten wurden aber besser erhalten. Dieselben Seren aktivierten die 3 heterologen Phosphomonoesterasen und zwar vorwiegend die saure Phosphatase, viel geringer die alkalische Phosphatase und in unbedeutendem Umfang die spezifische Nukleotidase. Wurden die Poole beider Gruppen gemischt, so zeigten die Enzymwerte ein modifiziertes Verhalten, aber die Änderung des kinetischen Einflusses der Seren war noch deutlicher. Die Beschleunigung der Aktivität der heterologen sauren Phosphatase hat abgenommen; die alkalische Phosphatase wurde sehr stark aktiviert und die Wirkung auf Schlangengift 5-Nukleotidase zeigte nur eine geringe, unbedeutende Abnahme. Wurde ein weiterer Pool aus einigen normalen Seren bestehend (freiwilligen Spendern) unter ähnlichen experimentellen Bedingungen geprüft, so waren die Ergebnisse wiederum etwas verschieden.

New experimental results concerning the nonlinear absorption of V2O5 single crystals are reported. A Q-switched ruby laser have been used to measure the two-photon absorption coefficient at 694.3 nm. The results are analysed and interpreted with respect to the second-order attenuation of the light propagating through a plane-parallel medium.

New experimental results concerning the nonlinear absorption of VO single crystals are reported. A Q-switched ruby laser have been used to measure the two-photon absorption coefficient at 694.3 nm. The results are analysed and interpreted with respect to the second-order attenuation of the light propagating through a plane-parallel medium. [ABSTRACT FROM AUTHOR]

Hexene-1 isomerized mainly to cis-hexene-2 in the presence of Co(N2)(PPh3)3. The reaction is second order in catalyst concentration and is strongly inhibited by hexene-2. The migration of the hydrogen atoms is taking place presumably in a dinuclear intermediate.