A new cell line of rat gasserian ganglion neurinoma NGUK-1

A new cell line has been derived from the rat gasserian ganglion neurinoma NGUK-1 induced by transplacental administration of ethylnitrosourea. It is characterized by an astrocyte-like growth pattern at the low cell density, and by an epitheliocyte-like pattern in the confluent monolayer. The cell line displays a high proliferative activity, its maximum mitotic index and proliferative pool being--2.5 and 96%, respectively. The chromosome number ranges between 20 to 100. The chromosome modal number is 39--44. The new cell line has been used for the express diagnostic of rabies, for determination of serum glial toxicity in neurologic patients, and interferon titration.     

An analysis of the interaction of the parietal and visual regions of the cortex with the posterior lateral nucleus of the thalamus]

Cooling and ablation of the parietal associative (P) and primary visual projection (VI) areas in nembutalized cats revealed facilitating and inhibitory descending influences of the above areas on the postero-lateral nucleus (LP) of the ipsilateral thalamus where visual signals generate an early specific and a late unspecific components of heterogenous evoked responses. Unidirectional influences activating the early component and fully controlling the appearance and course of the late component are more manifest in P which is a part of the same associative brain system as LP; they are less manifest in VI which belongs to the projection system. At later cooling stages the centrifugal influences of P and VI are sometimes of opposite signs; this effect is connected with reciprocal relations between projection and association systems and processes or selfcontrol within the association system. The corticofugal effects also participate in the common activity of P and VI taking place to a certain degree at the level of the LP which activates these cortical structures.     

Coinheritance of chromosomes 3 and 11 in the patients with autosomal recessive polycythemia from Chuvachia

Inheritance of chromosomes 3 and 11 in the families with Chuvash autosomal recessive polycythemia and in control group with no disease symptoms was examined using polymorphic dinucleotide markers D3S1597 and D3S1263, mapped to region 3p25, and D11S4111, D11S4127, and D11S1356, mapped to region 11q23. All patients were homozygous for the C598T mutation in the VHL gene (3p25). The analysis showed that in 75% of the cases, chromosome 3 carrying C598T mutation was coinherited with certain chromosome 11, which differed from 50%, expected upon independent inheritance of each chromosome. In case of chromosome 3 without C598T mutation, this pattern was observed neither in healthy sibs form the families with autosomal recessive polycythemia (44%), nor in the control group (43%). These results suggest that in case of the C598T mutation in the VHL gene, chromosomal loci 3p25 and 11q23 are inherited not independently, compared to the inheritance of these loci in the absence of the mutation in healthy sibs from the affected families (chi2 = 16.14; P < 0.001), and also in the control family sample (chi2 = 17.91; P < 0.001).     

The effect of reproduction biotopes on the genetic differentiation of populations of sockeye salmon Oncorhynchus nerka

Variation of mitochondrial DNA (mtDNA) was examined in nine populations from three lake-river systems of Chukotka and Kamchatka. Significant differences were found between most of the sockeye salmon samples studied. The genetic differences among populations were not high and often did not correlate with the geographical distances between them. The low population divergence is explained by a short time of existence of most of them, having been formed after the recession of the upper Pleistocene glacier. When the populations were grouped according to their spawning biotopes (river or lake), they in general appeared more genetically similar than upon their grouping by geographical location (the lake-river systems). The differences between the river and lake populations in the lake--river systems increased from north to south.     

The formation of the segmental projections of the primary afferents of the wing and leg in the chick embryo spinal cord]

A comparative HRP study of formation of connections between primary sensory nerve fibers and motoneurones in brachial and lumbosacral cord segments has been made on chick embryos between the 6.5th and 10th days of incubation. HRP was applied to the cut ends of the appropriate nerves via suction pipettes on isolated superfused spinal cord preparation. The first contacts between primary sensory collaterals and motoneuronal dendrites were found to appear both in lumbosacral and branchial cord segments at the same stage, i.e. at the 7.5-8th days of development. This observation does not confirm the widely accepted belief on rostrocaudal sequence of development of the spinal cord, indicating that exceptions from this developmental gradient are quite possible.