Study of the in Vivo Functional Role of Mutations in the BTB Domain of the CP190 Protein of Drosophila melanogaster.

The Drosophila transcription factor СР190 is one of the key proteins that determine the activity of housekeeping gene promoters and insulators. CP190 has an N-terminal BTB domain that allows for dimerization. Many of known Drosophila architectural proteins interact with the hydrophobic peptide-binding groove in the BTB domain, which is presumably a mechanisms for recruiting CP190 to regulatory elements. To study the role of the BTB domain in the interaction with architectural proteins, we obtained transgenic flies expressing CP190 variants with mutations in the peptide-binding groove, which disrupts their interaction with architectural proteins. As a result of the studies, it was found that mutations in the BTB domain do not affect binding of the CP190 protein to polytene chromosomes. Thus, our studies confirm the previously obtained data that CP190 is recruited to regulatory elements by several transcription factors interacting, in addition to BTB, with other CP190 domains.

Study of the Association of Ouib and Nom with Heterochromatin in Drosophila melanogaster.

In Drosophila, a large group of actively transcribed genes is located in pericentromeric heterochromatin. It is assumed that heterochromatic proteins recruit transcription factors to gene promoters. Two proteins, Ouib and Nom, were previously shown to bind to the promoters of the heterochromatic genes nvd and spok. Interestingly, Ouib and Nom are paralogs of the M1BP protein, which binds to the promoters of euchromatic genes. We have shown that, like M1BP, the Quib and Nom proteins bind to CP190, which is involved in the recruitment of transcription complexes to promoters. Unlike heterochromatic proteins, Ouib and Nom do not interact with the major heterochromatic protein HP1a and bind to euchromatic promoters on polytene chromosomes from the larval salivary glands. The results suggest a new mechanism for the recruitment of transcription factors into the heterochromatic compartment of the nucleus.

[The principle of the three-dimensional visual environment of the operating field in rhinosurgery]. / Printsip trekhmernoi vizual'noi sredy operatsionnogo polya v rinokhirurgii.

RELEVANCE: Traditional endoscopes that create a two-dimensional image cannot provide stereoscopic imagining of the operating field, which does not allow simultaneous synchronization of visual perception with the surgeon's handwork. The operator still achieves in-depth perception through tactile and visual cues, such as the interaction of instruments or the continuous movement of the endoscope. OBJECTIVE: To examine the three-dimensional visual environment for the operating field in endoscopic rhinosinus surgery based on the stereopsis phenomenon. RESULTS: Thanks to multi-spiral computed tomography, we have examined the functional structure features of ram's synonasal region, and described the system of the accessory nasal cavities. We practiced, and compared the techniques of endoscopic rhinosinus surgery using traditional methods versus a three-dimensional visual environment. As a result, we found the advantages of the live surgery in a virtual reality helmet, confirmed by the NASA Task Load Index questionnaire. CONCLUSION: The use of a virtual reality helmet in rhinosurgery allows the operator to work in a three-dimensional visual environment based on the phenomenon of stereopsis, as a qualitatively improved method of surgical wound videoscopy.

C2H2 Zinc Finger Proteins: The Largest but Poorly Explored Family of Higher Eukaryotic Transcription Factors.

The emergence of whole-genome assays has initiated numerous genome-wide studies of transcription factor localizations at genomic regulatory elements (enhancers, promoters, silencers, and insulators), as well as facilitated the uncovering of some of the key principles of chromosomal organization. However, the proteins involved in the formation and maintenance of the chromosomal architecture and the organization of regulatory domains remain insufficiently studied. This review attempts to collate the available data on the abundant but still poorly understood family of proteins with clusters of the C2H2 zinc finger domains. One of the best known proteins of this family is a well conserved protein known as CTCF, which plays a key role in the establishment of the chromosomal architecture in vertebrates. The distinctive features of C2H2 zinc finger proteins include strong and specific binding to a long and unique DNA recognition target sequence and rapid expansion within various animal taxa during evolution. The reviewed data support a proposed model according to which many of the C2H2 proteins have functions that are similar to those of the CTCF in the organization of the chromatin architecture.

[A simple method for determining antiepileptic preparations in biological fluids by using high-pressure liquid chromatography (HPLC)]. / Prostoi metod opredeleniia protivoépilepticheskikh preparatov v biologicheskikh zhidkostiakh s pomoshch'iu vysokoéffektivnoi zhidkostnoi khromatografii (VEZhKh).

The authors suggest a simple HPLC method with ultraviolet detection at 200 nm for finding barbiturates, diphenine, etosuccimide, and carbamazepin in plasma and saline using an original technology of liquid-liquid extraction. It allows clear chromatograms with a minimal amount of interfering compounds, a high extraction percentage (90-100%) and sufficient sensitivity to be obtained. A method has also been worked out for detecting clonazepam on the basis of solid-phase extraction (cartridge "Diapak-C16") precolumn concentration, and ultraviolet detection at 200 and 215 nm. The suggested extraction technologies also make possible successful monitoring of antiepileptics in the saline, for which the plasma/saline coefficients are calculated and the dependence between the degree of phenobarbital extraction into the saline and its pH is demonstrated.