[Distorted heterochromatin replication in Drosophila melanogaster polytene chromosomes as a result of euchromatin-heterochromatin rearrangements].

Studies of the position effect resulting from chromosome rearrangements in Drosophila melanogaster have shown that replication distortions in polytene chromosomes correlate with heritable gene silencing in mitotic cells. Earlier studies mostly focused on the effects of euchromatin--heterochromatin rearrangements on replication and silencing of euchromatic regions adjacent to the heterochromatin breakpoint. This review is based on published original data and considers the effect of rearrangements on heterochromatin: heterochromatin blocks that are normally underrepresented or underreplicated in polytene chromosomes are restored. Euchromatin proved to affect heterochromatin, preventing its underreplication. The effect is opposite to the known inactivation effect, which extends from heterochromatin to euchromatin. The trans-action of heterochromatin blocks on replication of heterochromatin placed within euchromatin is discussed. Distortions of heterochromatin replication in polytene chromosomes are considered to be an important characteristic associated with the functional role of the corresponding genome regions.

[Erysipelas as the cause of lymphedema].

The results of the treatment of 237 patients with lymphedema and recurrent erysipelas are analyzed. Direct correlation between the number of erysipelas in anamnesis and degree of lymphedema, and also their reciprocal aggravation are demonstrated that permits us to regard erysipelas as the cause of lymphedema.

[Mutation of Drosophila melanogaster glass-like suppress expression of mini-white transgenes and dependence on their genomic environment]. / Mutatsiia glass-like Drosophila melanogasater podavliaet ékspressiiu transgenov mini-white v zavisimosti ot ikh genomnogo okruzheniia.

Pleiotropic recessive mutation glass-like (gl-l) found in region 8C-10E of the X chromosome was shown to cause glass-like eyes having no boundaries between facets and a nonuniform pigment distribution in the presence of the endogenous white gene. The gl-l mutation completely inhibited expression of the mini-white transgene contained in several constructs, but the effect depended on the site of construct integration in the genome. The mutation had no effect on the expression of the white transgene having the enhancer and flanked by insulators. The gl-l mutation did not affect the extent of mosaic eye pigmentation when a construct with mini-white was inserted in the telomeric or pericentric region. However, in most cases it completely inhibited the mosaic mini-white expression when cloned heterochromatic repeats were adjacent to the reporter gene in a construct. The gl-l gene was assumed to play a role in the formation of the chromatin structure, because the effect of its mutation on expression of the white transgene depended on the transgene insertion site, the presence of insulators or an enhancer in the vicinity of the transgene, and on the adjacent heterochromatic repeats.

[Evaluation of results of surgical treatment of obliterating thrombangiitis in patients living in the North Arctic]. / Otsenka rezul'tatov khirurgicheskogo lecheniia obliteriruiushchego trombangiita u bol'nykh, prozhivaiushchikh v usloviiakh Krainego Severa.

Immediate and long-term results of surgical treatment of patients with obliterating thrombangiitis in patients living in Arctic North are analyzed. It is revealed that course of disease depends on length of patient's stay in Arctic North. These patients were younger, demonstrated more intensive progression of disease and more distal type of arterial lesion. Surgical treatment permitted to save 75.9% extremities in patients living in Arctic North with thrombangiitis and critical ischemia during 5 years after surgery that is worse than in patients living in Moscow region -- control group (86.1%). In long-term period more stable positive result was achieved after indirect revascularisation (save of extremity 78.3%).