[Face trauma in young people: medical and social aspects of the problem].

Problem of maxillofacial traumatism in juvenile age group has not only medical but also social aspect. The social aspect of the problem is in traumatism steady growth in this most vulnerable in the social attitude population group that lead not only to considerable disability but to significant society expenditures on patients rehabilitation. Medical aspect of the problem is in the special character of young organism biological reaction upon trauma that should be taken into consideration when organizing medical care to the victims.

[Characteristic features of induced mutagenesis in hybrid dysgenesis systems of Drosophila melanogaster]. / Osobennosti indutsirovannogo mutageneza v sistemakh gibridnogo disgeneza u Drosophila melanogaster.

The mutagenic effect of low-dose gamma-irradiation was studied in Drosophila melanogaster systems of hybrid dysgenesis by estimating polytene chromosome rearrangements, recombination frequency, and viability at the embryonic and postembryonic developmental stages. A dose of gamma-irradiation which had no effect detectable by routine line crossing proved to significantly reduce the number of recombinants in the H-E and P-M systems and mortality at postembryonic stages. However, this combined effect was obtained if irradiation followed transposition, i.e., it depended on the application sequence of the mutagenic factors. The reverse order of the mutagenic treatment led to summation of the effects: as compared to either control, the frequencies of the dominant allele mutations as well as the larval and pupal mortality in F2 increased significantly (at the level of 99.9%). This allowed us to estimate the contribution of extremely low-dose gamma-irradiation into the mutagenic effect, which was impossible under routine conditions.

[A new method for the surgical treatment of fractures of the mandibular condyle]. / O novom sposobe khirurgicheskogo lecheniia perelomov myshchelkovogo otrostka nizhnei cheliusti.

Four variants (modifications) of the method of surgical treatment of condylar process fracture, defended with the author certificate on invention, are described. Indications to application of each variant are determined, their detailed descriptions are given. One analyses 124 cases of using the method in clinic.

[Features of ontogenetic development of Drosophila melanogaster in the dysgenetic cross system]. / Osobennosti ontogeneticheskogo razvitiia Drosophila melanogaster v sisteme disgeneticheskikh skreshchivanii.

Three families of mobile elements that induce P-M, H-E, and I-R hybrid dysgenesis in Drosophila melanogaster were activated by crossing files of different cytotypes. Manifestation of gonadal sterility in F1 hybrid progeny was dependent on the temperature of development. The systems differed significantly in lethality of F2 hybrids at various stages of ontogeny (embryos, larvae, pupae, and adult flies). The highest embryo lethality was found in the P-M system at the cleavage stage. In the I-R and H-E systems, the peak of embryonic death corresponded to the stages of blastoderm and organogenesis, respectively. Experimental results are discussed in view of molecular and cytological characteristics of interacting strains and existing hypotheses for regulation xof transposition of P, hobo, and I mobile elements.

[Ectopic interactions of Drosophila melanogaster polytene chromosomes in the H-E system of hybrid dysgenesis]. / Izuchenie éktopicheskikh vzaimodeistvii politennykh khromosom Drosophila melanogaster v sisteme H-E gibridnogo disgeneza.

Analysis of salivary gland polytene chromosomes of Drosophila melanogaster age III larvae has demonstrated that inversions make up high percentage of aberrations induced by transposition of the hobo element. The frequency of inversions increases upon irradiation. In view of the fact that transpositions of mobile elements and irradiation can considerably affect the homology of associating regions, ectopic chromosome contacts were analysed. On the one hand, this analysis has revealed general features for all types of crosses, such as the prevalence of intrachromosomal contacts over interchromosomal ones, predominant localization of both types of contacts in telomeric regions of chromosomes and lower frequency of their occurrence on X chromosome in males as compared with females. On the other hand, the specificity of ectopic conjugation in different types of crosses has been determined. Given a constant average frequency of ectopic contacts in the D. melanogaster genome, differences in their distribution in chromosomes have been detected. Chromosomes of pure lines differ from their homologues in dysgenic hybrids by distribution of ectopic conjugation peaks and by localization of a number of unique events. On the basis of our own experiments and literature data, the role of ectopic contacts as structural formations connecting chromosome regions similar in their functional activity, rather than in nucleic-protein characteristics, is discussed.

[Experience in using the surgical-orthodontic method proposed by V. V. Donskoi for treating mandibular fractures]. / Opyt primeneniia operativno-ortopedicheskogo metoda lecheniia perelomov nizhnei cheliusti, predlozhennogo V. V. Donskim.

The author analyzes his experience gained in the treatment of 200 patients with mandibular corner and denture fractures by the orthodontic surgery method developed by V. V. Donskoi. Uni- and bilateral mandibular corner fractures made up 164 cases, the rest were combined injuries to the corner on the one side and to the body or condyle on the other side. 195 patients were operated under conduction analgesia when sitting in the dental chair and in the rest 5 cases condyle osteosynthesis was carried out on the one side and Donskoi's osteosynthesis on the other side under general anesthesia. Surgical procedure did not differ from that described earlier. Kirschner's pin, annealed [correction of preburnt] to make it less elastic, was horizontally inserted into the mandibular branch at the level of the posterior dental necks through a mucosal puncture and then shaped to match mandibular denture and fixed to the teeth with wire ligatures. Mandibular traction was carried out for 3-7 days, if necessary. The mean patient's stay in hospital made up approximately 22.7 days, total number of invalidity days 30.1. Infectious inflammatory complications were recorded in 9 patients. The advantages of the described method are discussed and recommendations on its practical use are given.

[Effects of gamma-irradiation on the gonadal cells of Drosophila melanogaster under varying conditions of hybrid dysgenesis]. / Vliianie gamma-oblucheniia na gonial'nye kletki Drosophila melanogaster v raznykh usloviiakh gibridnogo disgeneza.

Comparative analysis was carried out with respect to the results of combined effects of gamma-irradiation and transposition of mobile elements in Drosophila, depending on the succession of their application. As turned out, introduction of the P and hobo elements into the M' line, prior to irradiation, resulted in decreased number of unfertilized eggs and reduced the proportion of flies killed at the larval and pupal stages. However, opposite effects were shown, when the P element was introduced following irradiation: the number of unfertilized eggs and that of the flies killed at the larval and pupal stages has significantly increased, as compared to the control. Interaction between the processes induced at the level of DNA repair both by gamma-irradiation and the P' elements' transposition is suggested.

[Mutational variability of enzyme loci in unstable Drosophila melanogaster strains]. / Mutatsionnaia izmenchivost' fermentnykh lokusov v sisteme nestabil'nykh linii Drosophila melanogaster.

Biochemical analysis of a number of related unstable Drosophila melanogaster strains was carried out. These strains have been shown to undergo mutational transformations caused by insertion/excision of transposable elements (Gerasimova, 1985). Activity and mobility variants of alpha-GPDH, ADH, SOD, G6PD, 6PGD and EST-6 were analysed. Two loci controlling SOD and 6PGD proved to be invariable, the loci alpha-Gpdh and Est-6 causing reduced activity of their products in the initial strain ctMR2. The direct and reversed transformations analogous to the mutational passages of morphological characters were traced in two loci controlling ADH and G6PD. The data obtained are discussed in terms of up-to-date views on the functional role of transposable elements, in relation to the genetic stability of the strains studied, under the multiple transpositions of mobile elements.

[A method for bone suture of the mandible]. / Sposob kostnogo shva nizhnei cheliusti.

A technique of mandibular osteosynthesis with a bone suture is described, consisting in the formation of 2 pairs of through holes close to the fracture plane and fixation of fragments with a thread drawn alternately through the upper pair of holes and, after a preliminary crossing on the internal surface of the bone and overlapping the lower edge of the mandible, through the lower pair of holes. The horizontal portion of thread passing longitudinally between the upper holes is entrapped with one of the thread ends, then the thread is stretched tight and its ends are tied. A wire may be used as suture material. This technique was used in the treatment of 38 patients.

[A new method of dental splinting]. / Novyi sposob nazubnogo shinirovaniia.

A wire splint and the technique of its application for jaw immobilization is described. Stainless steel wires 0.7 to 1 mm in diameter are used to form the smooth and looplike parts applied to dentition in such a manner that loops be located closer to gingival margin and smooth part be situated in the vicinity of incisive margins of the teeth. Usually, the smooth part is an extension of looplike part of the splint and serves to embrace the lateral teeth into the splint. Both ends of the smooth part can be twisted together. The results of clinical application of the splint are compared to most common techniques and suggest major advantages of the novel splint.