Immortalization of Human Keratinocytes Using the Catalytic Subunit of Telomerase.

A new stable line of human keratinocytes was obtained. The cells have altered morphology, both abnormal chromosomal composition and expression of keratinocyte markers, do not show contact inhibition, could be cultured in various media and have limited stratification ability in vitro. Upon transplantation into nude mice the cells have tumorigenic properties.

[Melfalan in the treatment of proliferative vitreoretinopathy (experimental study)]. / Melfalan pri lechenii proliferativnoi vitreoretinopatii (eksperimental'noe issledovanie).

PURPOSE: To study of the effectiveness of the drug Melphalan as an antiproliferative agent during experimental proliferative vitreoretinopathy (PVR). MATERIAL AND METHODS: The experimental study used data from 24 eyes of 12 Chinchilla rabbits weighing 2.5-3.0 kg, which had PVR modeled in both eyes by intravitreal injection of a culture of heterogeneous activated fibroblast cells consisting of 200,000 cells in 0.1 ml. Treatment of experimental PVR was performed 1 day after the modeling process. In the first group of animals (6 eyes), 0.02 mg of Melphalan was administered intravitreally. In the second group of animals (6 eyes), 0.005 mg of Melphalan concentrated in 0.1 ml was administered intravitreally. Left eyes in both groups remained without treatment. Animals were observed for 1 month using biomicroscopy and ophthalmoscopy. 30 days after the animals were removed from the experiment, the eyes were enucleated, fixed in 10% buffered formalin and subjected to standard histological examination. The study of paraffin sections of the eyes was performed using the microscopic system «Leica¼ (Leica Microsystems, Germany) with built-in digital camera at the magnification of 200-600. RESULTS: In groups 1 and 2 of the study in the eyes of rabbits that received treatment, PVR was absent, unlike the eyes without treatment, where PVR remained. In group 1, where the dose of Melphalan was 0.02 mg in 0.1 ml, there were changes in the RPE (retinal pigment epithelium), which was regarded as a retinotoxic effect. Glial degeneration and thinning of the retina with disappearance of the photoreceptor layer (the outer nuclear and plexiform layers) resulted from the disturbance of retinal metabolism caused by RPE destruction. In group 2, structure of the retina remained more intact: isolated foci were noted with a decrease in the volume of the outer nuclear layer, shortening of rods and cones with preservation of the inner layers of the retina. CONCLUSION: A single intravitreal injection of 0.005 mg Melphalan had a positive therapeutic antiproliferative effect on the PVR model with minimal retinotoxic changes.

[Perinatal development of mammillotegmental connections in rats].

Development of direct axonal connections of the hypothalamic mammillary bodies with ventral and dorsal tegmental nuclei of Gudden was studied on fixed rat brains from day 14 of embryonic development until day 10 of postnatal development using the method of diffusion of the lipophilic fluorescent carbocyanine tracer 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate along the neuronal membranes. The tracer was inserted into the mammillary bodies or into the tegmentum and after incubation in a fixative fluorescent nerve cells and nerve fibers were visualized in the brain tissue. The mammillotegmental tract was found to start developing earlier than other conducting systems of the mammillary bodies. On days 14-15 of embryonic development, it was visualized as a bundle of axons running from the mammillary bodies caudally to the midbrain. A group of neurons in the midbrain tegmentum and their axons going to the mammillary bodies via the mammillary peduncle were first visualized on day 19 of embryonic development. The mammillotegmental tract and mammillary peduncle developed progressively from the moment of birth. Ventral and dorsal tegmental nuclei were formed in the midbrain by day 10 of the postnatal development. Thus, the formation of reciprocal connections of the mammillary bodies with midbrain tegmental nuclei was first described during perinatal development in rats.

Perinatal development of the mammillothalamic tract and innervation of the anterior thalamic nuclei.

Axonal projections originating from the mammillary bodies represent important pathways that are essential for spatial information processing. Mammillothalamic tract is one of the main efferent projection systems of the mammillary body belonging to the limbic "Papez circuit". This study was aimed to describe the schedule of the mammillothalamic tract development in the rat using carbocyanine dye tracing. It was shown for the first time that fibers of the mammillothalamic tract being the collaterals of the mammillotegmental tract axons start bifurcating from the mammillotegmental tract on E17. The axons of the mammillothalamic tract grow simultaneously and reach the ventral region of the anterior thalamus where they form first terminal arborizations on E20-E21. Ipsilateral projections from the medial mammillary nucleus to the anteromedial and anteroventral thalamic nuclei develop from E20 to P6. Bilateral projections from the lateral mammillary nucleus to the anterodorsal thalamic nuclei develop later, on P3-P6, after the formation of the thalamic decussation of the mammillary body axons. Unique spatial and temporal pattern of the perinatal development of ascending mammillary body projections to the anterior thalamic nuclei may reflect the importance of these connections within the limbic circuitry.