NADPH-dependent reduction of amaranch in liver microsomes characterized the quantity of low spin forms of cytochrome P-450.

We confirmed that NADPH-dependent anaerobic amaranch reduction in rat liver microsomes is compatible with the interaction of the dye with Fe(III) heme of cytochrome P-450 as the type II substrate. This process is rate-limiting in the whole reaction. High positive correlation (r = 0.949) between the values of Vmax for reaction of NADPH-dependent anaerobic amaranch reduction and the relative content low spin forms of cytochrome P-450 determined by ESR in microsomes from liver of control and induced by PB, BP, IS and 4-MP rats was observed. Relative content of low spin forms of cytochrome P-450 determined by ESR was increased according to BP less than PB less than control less than IS approximately 4-MP; Vmax values increased according to BP less than PB less than control less than IS less than 4-MP. Thus, reaction of NADPH-dependent anaerobic amaranch reduction may be used for determination of low spin forms of cytochrome P-450 at physiological conditions.     

Comparative characterization of the ultrastructure of intestinal epithelium of various sturgeon species

The ultrastructure of the mid-intestine of four sturgeon species and their hybrids was studied. Apart from enterocytes and glandular goblet cells, the cells with microvilli, endocrine cells, and immunocompetent elements were revealed. Specific cells responsible for the primary immune response, analogous to mammalian M-cells, were discovered in sturgeon fishes. The ultrastructural characteristics common for the mid-intestinal epithelium of all the sturgeon fishes studied were determined. Species-specific features of intestinal epithelium of the parent species, which were characteristic of the hybrids, were revealed.     

Germline and Somatic Mutations in Archived Breast Cancer Specimens of Different Subtypes

Molecular Biology - Molecular profiling of tumors may provide promising options for personalized treatment. We have examined the spectrum of germline and somatic mutations in 23 breast cancers (BC)...     

Fine structure of the female reproductive system in Sobolevicanthus gracilis and Cloacotaenia megalops (Cestoda: Cyclophyllidea)

The fine structure of the female reproductive organs and ducts in two cyclophyllidean cestodes was studied by transmission electron microscopy. All the studied ducts (vitelline, fertilization and vaginal ducts, and oviducts) as well as the uterine and ootype walls have the luminal surface elevated to form apical cytoplasmic lamellae and are surrounded by bands of circular muscules, which are attached to the basement layer. The structure of the studied ducts epithelium corresponds to the pattern described in other ducts of the cestode genital system, namely a nucleate syncytial layer. An exception is the vagina Sobolevicanthus gracilis, in which the surface is lined with not numerous atypical microtriches. The comparison of our results and the data reported for other species is given. It is found out that in different species of cestodes forming oligolecital eggs, there are observed various uterine structures and diverse contacts between the eggs capsules and the uterine epithelium. The formation of special structures and contacts is the evolutionary way from the extrauterine type to more progressive intrauterine type of embryo development in cestodes.     

Structure and functions of the brain orexin-containing neurons

The results of investigations of the new discovered brain orexin neurons, their chemical structure, localization and functions are reviewed. The following data are described: the specifics of orexins mRNA, orexins A and B and their receptors; connections between orexin neurons and neurons from different structures of the brain and spinal cord and the participation of the orexin neuron system in the functional regulation.     

The symbiotic microflora associated with the tegument of proteocephalidean cestodes and the intestines of their fish hosts

The indigenous symbiotic microflora associated with the tegument of proteocephalidean cestodes and the intestines of their fish hosts has been investigated in morphological and ecological aspects. The indigenous microflora associated with the cestode tegument consists of the nannobacteria population, which was present obligatorily on the surface of tegument, and the "deep microflora". The deep microflora associates with some few species of parasites only. Each individual host-parasite micro-biocenosis includes specific indigenous symbiotic microorganisms, with the differing microfloras of host intestine and parasite. Physiology, biochemistry and/or diet of hosts apparently influence on the symbiotic microflora's structure of parasites. The least bacteria abundance and diversity of their morphotypes were observed in the parasites from baby fishes. The diversity and abundance of bacteria were increased with the fish host ageing and the formation of the definitive structure of its intestine. It is an evidence of the gradual invading of the intestinal parasites (cestodes) tegument by bacterial cells. The invading is realized on the base of the microflora that was present in the food of fish host. The symbiotic microflora has specific morphological features, can regulate the homeostasis of the cestodes and fish hosts and also can maintain equilibrium of alimentary and immune interrelations in the host-parasite system.     

Ultrastructure adaptations of symbiotic bacteria associated with freshwater fish and their cestode parasites

The ultrastructure of symbiotic bacteria colonizing the mucous membrane of the gut of freshwater fish and the tegument surface of their cestodes was studied. A comparative analysis of published and original data made it possible to define the ultrastructure peculiarities promoting the adaptation of bacteria to the digestive transport surfaces of fish and their intestinal parasites. The studied peculiarities may be split into three groups: (1) the structure and composition of the bacterial cell surface, which allows the colonization of gut epithelia and cestode tegument; (2) the intracellular ultrastructure of the bacteria; and (3) the reorganization of cell types, i.e., the formation of the dormant cells and nanobacteria.