Natural history of SLC11 genes in vertebrates: tales from the fish world

Background  

The SLC11A1/Nramp1 and SLC11A2/Nramp2 genes belong to the SLC11/Nramp family of transmembrane divalent metal transporters, with SLC11A1 being associated with resistance to pathogens and SLC11A2 involved in intestinal iron uptake and transferrin-bound iron transport. Both members of the SLC11 gene family have been clearly identified in tetrapods; however SLC11A1 has never been documented in teleost fish and is believed to have been lost in this lineage during early vertebrate evolution. In the present work we characterized the SLC11 genes in teleosts and evaluated if the roles attributed to mammalian SLC11 genes are assured by other fish specific SLC11 gene members.     

Fast calculation of the quartet distance between trees of arbitrary degrees

Background  

A number of algorithms have been developed for calculating the quartet distance between two evolutionary trees on the same set of species. The quartet distance is the number of quartets – sub-trees induced by four leaves – that differs between the trees. Mostly, these algorithms are restricted to work on binary trees, but recently we have developed algorithms that work on trees of arbitrary degree.     

Changes in the lymphoid tissue and in the level of corticosteroids in staphylococcal intoxication and infection]

A complex quantitative study of changes of proliferative processes in lymphatic vessels on the one hand and changes of the level of corticosteroids in the peripheral blood in staphylococcal intoxication and infection in the same rats on the other hand has been carried out. In the work H3-thymidine has been used. The comparison of the obtained morphological data with the dynamics of the change in the corticosteroid level shows that the decay of lymphocytes, the devastating of light centers and the cortical substance of lymph nodes, an abrupt lowering of the amount of DNA-synthesizing and mitotically dividing cells take place in the period associated with a release of a great amount of corticosteroids into the blood. The drop of their level to control values goes in parallel with increasing the amount of DNA-synthesizing and mitotically dividing cells. The obtained data suggest that the leading role in those changes of the lympoid tissue which had been described by a number of authors in infectional processes is played by corticosteroids.     

The action of tropic adenohypophyseal hormones when administered intraventricularly on rat behavioral reactions

In experiments on rats the influence was studied of tropic hormones of adenohypophysis--somatotropin, thyrotropin and adrenocorticotropin (STH, ThTN and ACTH respectively) on the elaboration and extinction of conditioned reaction of active avoidance (CRAA) in Y-maze and behaviour in the open field under microinjections of hormones into the brain lateral ventricle (0.001-0.002 ME). It has been shown that all studied hormones improve animals learning at negative pain reinforcement; ThTH and ACTH retard it in contrast to STH, which accelerates the extinction of the elaborated CRAA; tropic hormones exert differentiated influence on rats behaviour in the open field. No distinct correlation was found between behavioural manifestation and the level of catecholamines in the rats hypothalamus.     

The sexual function of mature rat males after prenatal modulation of cholinergic system

The data obtained have shown that prenatal exposure of pregnant rat females of 9-19-day pregnancy to N-cholinolytics as compared to M-cholinolytics produce long-term behavioural changes in pubescent rat progeny. Pubescent rat progeny had low dynamics of gaining sexual experience and decreased sexual activity with equal disturbance of motivation and coitus. The number of males with absence of sexual activity was above that of the control group. We suggest that sexual dysfunction of offspring adulthood was provoked by introduction of ganglerone (N-cholinolytic) which had been injected on 9-11 and 12-14 days of gestation, and metamyzil (M-cholinolytic) injected on 9-11 days of gestation. Apparently, regulation of neuronal mechanisms for sexual function is disturbed as a consequence of lasting change in neurotransmitter activity. It is suggested that dopaminergic activity in brain limbic structures was affected the most. The significant decrease in blood testosterone values has also been elucidated.     

A Search for a New Cellular Model to Study the Pharmacological Activity of Progesterone Analogues

The possibility of using the endometrial cell line as a model for studying the pharmacological activity of progesterone analogues is considered. Conditions for obtaining and culturing of endometrial cell lines are described, the morphological characteristic is given, and the immunophenotypic profile, karyotype, and expression of progesterone and estrogen receptors are presented. Not all studied endometrial lines showed the ability to decidualize cells under the action of hormonal inducers (combinations of estradiol with progesterone and its analogues). It appeared that lines sensitive to hormones are able to increase the secretion of specific markers of decidualization under the action of highly active gestagenes (progesterone analogues) to a greater extent than under action of progesterone. These data are a basis for further development of the cellular model for studying the pharmacological activity of gestagenic compounds.     

Adrenergic mechanisms of the regulation of stages of chemical carcinogenesis: role of presynaptic receptors

A modifying effect of a catecholamine precursor (L-DOPA, 20 mg/kg, intraperitoneally) on various stages (initiation and promotion) of hepatocarcinogenesis, induced by N-nitrosodiethylamine (NDEA, 85 mg per 1 litre of tap water) was studied in chronic experiments on 150 male rats. L-DOPA administration prior to NDEA (influence on initiation) stimulated hepatocarcinogenesis considerably, while its administration after NDEA (influence on promotion) inhibited the realization of a carcinogenic effect. A statistically significant decrease in noradrenaline hypothalamus content was identified during early stages of chemically induced neoplastic transformation of hepatic cellular elements (stages of diffuse and focal proliferation). The results are discussed in terms of the regulatory role of the tone of the adrenergic autonomous nervous system component at the level of presynaptic inhibitory receptors in realization of the chemical carcinogenic effect.