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Photoluminescence spectra of impurity centers containing anion vacancy Cd+ or Zn+ in alkali-earth fluorides have been studied. A comparison with luminescence spectra of photochromic centers (PCs), which can be considered as perturbed F centers, shows that luminescence of centers Cd+ or Zn+ is similar to that of F centers; therefore, it is caused by charge transfer from an impurity ion to an anion vacancy. [ABSTRACT FROM AUTHOR]

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In meiotic prophase I, chromatin fibrils attached to the lateral elements of the synaptonemal complexes (SC) form loops. SCAR DNA (synaptonemal complex associated regions of DNA) is a family of genomic DNA tightly associated with the SC and located at the chromatin loop basements. Using the hybridization technique, it was demonstrated that localization of SCAR DNA was evolutionarily conserved in the isochore compositional fractions of the three examined genomes of warm-blooded vertebrates—human, chicken, and golden hamster. The introduction of the concept of the comparative loops (CL) of DNA that form of chromatin attach to SC in the isochore compositional fractions provided the calculation of their length. An inverse proportional relationship between the length of CL DNA and the GC level in the isochore compartments of the studied warm-blooded vertebrate genomes was revealed. An exception was the GCpoorest L1 isochore family. For different compositional isochores of the human and chicken genomes, the number of genes in the CL DNA was evaluated. A model of the formation of GC-rich isochores in vertebrate genomes, according to which there was not only an increase in the GC level but also the elimination of functionally insignificant noncoding DNA regions, as well as joining of isochores decreasing in size, was suggested.

In meiotic prophase I attached to the lateral elements of the synaptonemal complex chromatin fibrils form loops. SCARs DNA (Synaptonemal Complex Associated Regions of DNA) is a family of genomic DNA sequences tightly associated with the synaptonemal complex and lying at the loop basements. Isochore compositional fractions of the human and chicken genomes were used as 32P-labeled probes for hybridization with the SCARs DNA isolated previously from the spermatocyte nucleus of the golden hamster Mesocricetus auratus. The localization of sequences, similar to golden hamster SCARs DNA in the human and chicken genome isochores was established. It was concluded that SCARs DNA localization into isochore com- partments of examined genomes is evolutionary conservative.

Synaptonemal complex (SC) is a specific structure for prophase I of meiosis. Recently we have described synaptonemal complex tightly associated regions of DNA (SCARs DNA) as a particular family of genomic DNA. Now we reveal the evolutionary conservation of SCAR DNA sequences of vertebrates. This data correlates with universal morphology of SCs and similar processes proceed in prophase I of meiosis at representatives of different taxa.

The synaptonemal complex isolated from the spermatocyte nuclei by exhaustive hydrolysis of the latter by DNase II contains tightly associated DNA sequences (SCAR DNA). Here we studied the compositional properties of a cloned family of SCAR DNA of golden hamster, namely we performed the localization of 27 SCAR DNA clones on compositionally fractionated genomic DNA from golden hamster. We observed that sequences of the SCAR DNA family are mainly localized in the GC-poor isochore families L1 and L2, that showed 63% hybridization signals. This means that 37% of signals is referred to the GC-rich isochores, indicating the presence of SCAR DNA overall the genome, even if each isochore family presents differences in density and sequence type. Moreover, the SCAR DNA sequences containing regions of homology with LINE/SINE repeats were observed in all the isochore families. The compositional localization of SCAR DNA is in agreement with the hypothesis that SC and SCAR DNA participate in the chromatin organization during the meiosis prophase I, which should result in the attachment of chromatin loops to lateral elements of SC along the whole length of the latter.

Transcutaneous electrostimulation (Amplipul's-4 unit) was used in 29 patients with diabetes mellitus and diabetic angioneuropathy. The impact was directed to three fields a session: paravertebral, musculus gastrocnemius, feet. Rheographically, a good clinical response with improvement of peripheral circulation was achieved.