[Osteocytes and the pathways of mechanical homeostasis optimization from the point of view of functional osteology].

The aim of this work was to determine, on the basis of the results of authors' own research and literature data, the main pathways of osteocyte (OC) influence on the mechanical homeostasis of the skeleton. The following pathways of reorganization of the architecture of bone structures are postulated: at the ultrastructural level without direct cell participation, through the bone matrix synthesis by osteoblasts and OC, through bone matrix resorption by osteoclasts and OC, the latter being able to resorb the surrounding mineral and organic matrix both separately, and conjointly. This reorganization results in local changes of the mechanical characteristics of bones due to changes in: porosity of interstitial spaces, transport ability of the lacunar-canalicular system, porosity of the area of osteoblastic-osteoclastic remodeling, modeling of bone structures.

[Hierarchy of spiral organization of skeletal structures. Interrelationship between structure and functions].

The objective of this review is to discuss the interrelationship between hierarchy of spiral organization of the structural elements of the skeleton and its mechanical characteristics with regard to functional-biological expediency. The following hierarchic levels of spiral organization of skeletal structures are defined: collagen chains, collagen molecules, microfibrils, fibrils, collagen fibers, osteon network and organization of osseous macrostructure responsible for torsion effect in weight bearing. This spiral organization creates the conditions, under which the directions of domineering forces in the bone usually do not coincide with the direction of the longitudinal crystallite axes.

[The parasitism characteristics of the causative agent of melioidosis in the host cells].

The electron microscopic study of the damaged areas of the lungs, liver, spleen and lymph nodes of guinea pigs infected with two P. pseudomallei virulent strains C-141 and 100 has revealed that this organism is a facultative intracellular parasite and exhibits tropism to reticuloendothelial cells of the body, parasitizing both in "professional" phagocytes (mononuclear, phagocytes, polymorphonuclear leukocytes) and "nonprofessional" phagocytes (capillary endotheliocytes, splenic and lymph-node reticulocytes). In the course of their intracellular development P.

[Capsule formation in the causative agent of glanders].

Electron-microscopic and electron-cytochemical method were used to indicate the capability of Pseudomonas mallei (str. N 10230) to produce extracellular slime during the agent growth on the meat-peptone agar. In case of guinea pigs infection the agent forms a capsule that defends the pathogen from phagocytosis.