A Simplified Streptozotocin-Induced Diabetes Model in Nude Mice.

Preclinical studies of human cellular and tissue-based products (HCT/Ps) for transplantation therapy of type 1 diabetes mellitus (T1DM) necessarily involve animal models, particularly mouse models of diabetes induced by streptozotocin (STZ). These models should mimic the clinical and metabolic manifestations of T1DM in humans (face validity) and be similar to T1DM in terms of the pathogenetic mechanism (construct validity). Furthermore, since HCT/Ps contain human cells, modeling of diabetes in immune-deficient animals is obligatory.

Chemical Platform for the Preparation of Synthetic Orally Active Peptidomimetics with Hemoregulating Activity.

A novel chemical platform based on branched piperazine-2,5-dione derivatives (2,5-diketopiperazines) for creating orally available biologically active peptidomimetics has been developed. The platform includes a diketopiperazine scaffold with "built-in" functionally active peptide fragments covalently attached via linkers. The concept was applied to two hemostimulatory drugs, the dipeptide thymogen (GluTrp) and the tripeptide stemokin (IleGluTrp).

[Branched antimicrobial peptides].

Branched peptides E(RLAR)2, E[E(RLAR)2]2, E(KLAR)2, and E[E(KLAR)2]2 were synthesized on the basis of tetrapeptides RLAR and KLAR and glutamic acid bis(pentafluorophenyl) ester. Their minimal antimicrobial concentrations were shown to decrease along with increase in branching, achieving 12 microM for Escherichia coli cells, which is comparable to antimicrobial activities of temporin, magainin, and dermaseptin. The branched peptides were found not to act on human erythrocytes.

[Hydrodynamic stands for testing assisted circulation and artificial heart apparatus].

Problems arising in devising the assisted circulation apparatus and artificial heart can be solved only with investigations conducted on hydrodynamic models of the circulation system--the stands. An analysis of literature sources dealing with test stands justifies their classification according to the purpose, the types of tests, the specific structure and basic characteristics. It is necessary to proceed with further improvement of the stand equipment in the direction of creating a sufficiently accurate imitation of the anatomic structure and resilient properties of major arteries and veins, of constructing a geometrical and elastic model of the aorta, of pressure and flow control instruments at different points of the vessels, of the ones regulating the energy parameters, as well as of working out criteria for effectiveness of the devices to be used.

[Test of the "Biopulse-3" aortic balloon pumping apparatus].

Experiments on a specially constructed laboratory stand were set up with a view to determining power and dynamic possibilities of the translatory motion drive in the "Biopulse-3" unit when operating an intra-aortic ball-pump and also assessing the service properties of individual unit-blocks intended for injection, measurement and registration. Trial testing showed the drive to the suitable for using in the intra-aortic ballooning.