Biopolymer gels as components of protective medium for cryopreservation of spermatogonial stem cells.

Biopolymer gels attract a lot of attention in a field of biothechnology due to their excellent compatibility and degradation. Their application is also promising for cryopreservation of spermatogonial stem cells (SSCs) which is so necessary to preserve the fertility of young patients. The aim of the study was to determine the effectiveness of biopolymer gels as a component of cryopreservation medium for SSCs of immature rats at the stage of exposure to cryoprotectants.

[Perivascular lymphoid nodules].

As a result of investigation of lymphoid formations in the walls of the human tracheobronchial tree and the pulmonary stroma by means of morphological and morphometrical techniques, certain regularity in arrangement of the perivascular lymphoid noduli has been stated along the course of the lympho- and hemomicrocirculatory bed links. The periarterial lymphoid noduli of the tracheobronchial tree have certain morphological similarity and some differences, when comparing them with usual lymphoid noduli.

[The morphofunctional changes in the perivascular and lymphoepithelial nodes of the respiratory organs following antigenic stimulation].

Morphological, experimental-immunological methods with mathematical analysis were used in 108 Wistar line rats in the pre- and postnatal ontogenesis to study the lymphoid structures of the trachea, bronchi and stroma of the lungs. Two types of lymphoid nodules were detected in the respiratory organs of rats and man: 1. perivascularly located in the wall of the trachea, bronchi and stroma of the lungs; 2.

[The age-related characteristics of the lymphoid structures in the human respiratory organs].

It was found that the wall of the tracheo-bronchial tree and the lung stroma of man has two types of nodules: those located in the mucous membrane and adjoining the epithelium and those located in the fibrous-cartilagenous part of the wall of the trachea, bronchi and stroma of the lungs. The latter serve the purpose of defense of the internal medium of the body. It was established that lymphoid nodules of the respiratory organs undergo age-related involution.

[Lymphoid tissue during phylo- and ontogenesis].

In the process of evolution lymphoid tissue is isolated from the single hemolymphatic system as central and peripheral organs of the immune system. However there remains a close relationship between the lymphoid and myeloid tissues in the forms of perivascular lymphoid accumulations in organs both in the phylo- and ontogenesis. In mammals and man the diffusely disseminated within the body perivascular lymphoid tissue if differentiated in organoid-perivascular lymphoid follicles which are regularly located along the course of links of the hemo- and lymphocirculatory bed.

[Model of a hemolymphomicrocirculatory module].

An attempt is made to unify the terminology used for denotation the links of the lymphomicrocirculatory bed by means of analogy with the links of the hemomicrocirculation basing on the summarized literature data and on the results of the authors' investigations. An original model of the hemolymphomicrocirculatory module is presented reflecting interrelations of the blood and lymphatic system at the level of the microcirculatory bed. In order to confirm "capacity to work" in the model suggested, an explanation of the mechanism on retrograde and contrary blood stream and on development of local stases is given by means of schematic representation and demonstration of original microphotos.

[Structural mechanisms of regulation of the lympho-microcirculatory system].

The lymphatic vessels in total macro-microscopical preparations of various human organs and those in some laboratory animals have been injected with silver nitrate solution. There are various morphological structures that are capable to regulate the lymph flow and outflow rate in the microcirculatory lymphatic bed. A peculiar role belongs to the lymphatic postcapillaries (V.