[Quality indicators and structural requirements for Cardiac Arrest Centers-Update 2021]. / Qualitätskriterien und strukturelle Voraussetzungen für Cardiac Arrest Zentren ­ Update 2021: Deutscher Rat für Wiederbelebung/German Resuscitation Council (GRC).

An update of the first description of quality indicators and structural requirements for Cardiac Arrest Centers from 2017 based on first experiences and certifications is presented. Criteria were adjusted, substantiated and in some parts redefined for feasibility in everyday clinical use.

[The conservation of the genetic resources of deer (Cervidae) by the cryopreservation of their germ cells]. / Sokhranenie geneticheskikh resursov olen'ikh (Cervidae) putem kriokonservatsii ikh polovykh kletok.

Necessity of organization of a cryobank for the sperm of some taxa has been substantiated on the basis of the published data and authors' results concerning the state of genetic resources of the family Cervidae in Russia. A task has also been set to elucidate some factors that may affect the success of cryoconservation, such as the age of male donors; season; duration of sperm storage before and after freezing, including long-term storage; and the possibility of obtaining of sperm from perished males. Results are provided on the influence of these factors of the quality of spermatozoa obtained on three species of the Cervidae.

[The creation of genetic cryobanks and the use of the methods of developmental biology as a means for preserving rare animal species. III. The outlook, problems and limits: selection, modifications and mutations]. / Sozdanie geneticheskikh kriobankov i ispol'zovanie metodov biologii razvitiia kak sposob sokhraneniia redkikh vidov zhivotnykh. III. Perspektivy, problemy i ogranicheniia: selektsiia, modifikatsii i mutatsii.

A review of our own and literature data about perspectives, problems and limitations in the use of cryoconservation techniques and methods of developmental biology for the conservation of genetic resources is presented. It is demonstrated that the use of these methods may result in the selection and possibly leads to modifications and mutations in germ cells and embryos and in this way may change the genetic structure of restored populations as compared with the original ones. The need to improve current techniques of cryoconservation and accompanying biotechnological procedures in order to abolish these undesirable genetic effects is emphasized.

[The creation of genetic cryobanks and the use of the methods of developmental biology as a means for preserving rare animal species. II. The obtaining and cryopreservation of the embryos of wild mammals]. / Sozdanie geneticheskikh kriobankov i ispol'zovanie metodov biologii razvitiia kak sposob sokhraneniia redkikh vidov zhivotnykh. II. Poluchenie i kriokonservatsiia zarodyshei dikikh mlekopitaiushchikh.

A review of published data on obtaining, cryoconservation, and subsequent development of the embryos of wild animals. Development of the embryos until birth after freezing-thawing and transplantation of the embryos to recipient females was followed in eight species. Studies are mostly carried out in the zoos and some universities of USA, Canada, and UK. The Red Data Book species and artificially bred species are the main objects. In these studies, diverse methods of developmental biology were used: induced oocyte maturation, artificial fertilization and cultivation of the embryos in vitro, transplantation of the embryos to foster mothers of the same or closely related species, and obtaining of chimeras.

[The creation of genetic cryobanks and the use of the methods of developmental biology as a means for preserving rare animal species. I. The cryopreservation of the sperm of wild mammals]. / Sozdanie geneticheskikh kriobankov i ispol'zovanie metodov biologii razvitiia, kak sposob sokhraneniia redkikh vidov zhivotnykh. I. Kriokonservatsiia spermy dikikh mlekopitaiushchikh.

A review of published data on cryoconservation of the sperm of wild animals. Progeny of females inseminated with frozen-thawed sperm was obtained in 21 species and subspecies, including 11 from the Red Data Book. Mobility of the spermatozoa after freezing-thawing was estimated in 74 species, including 13 from the Red Data Book. Studies on cryoconservation have recently been carried out predominantly on the Red Data Book species, as well as the species intensely bred in the countries, where several founder individuals were introduced (deer in Australia and New Zealand). Large zoos and some universities in the USA, Canada and Great Britain are the main research centers.

[Creation of a European bison sperm cryobank as a method for preserving the genetic polymorphism of the species]. / Sozdanie kriobanka spermy zubra kak sposob sokhraneniia geneticheskogo polimorfizma vida.

Sperm was taken from one alive (by electroejaculation) and two dead (from epididymis tissue) wisent males, and was conserved by the method similar to that used to freeze sperm from cattle. Spermatozoon mobility and acrosome conditions underwent no noticeable changes when kept under preservation. Eight cows were fertilized with the sperm which had been kept in liquid nitrogen for three years. Four of them had hybrid calves. We also made genetic analysis for bull-donors: on blood groups, isoenzyme systems and the protein spectrum of blood serum and muscle tissue. The analysis revealed the rare antigene H' in one of the bulls and polymorphism in two isoenzyme systems in the other one. The results of the analysis proved that these animals can make valuable contribution to the developing genetic cryobank.

[New data on nuclear transplantation in mammals]. / Novye dannye o peresadkakh iader u mlekopitaiushchikh.

The results of studies on nuclear transplantation in mammals published in 1986 allow to suppose the causes of failure in experiments on mice and outline ways of overcoming these difficulties.

[Rhythmic processes in early embryogenesis timed by cell division]. / Ritmicheskie protsessy v rannem émbriogeneze, priurochennye k kletochnym deleniiam.

he data on rhythmic processes in early embryogenesis coinciding with cell divisions are considered. Possible mechanisms which determine the rhythm frequency and are its motive power are discussed, as well as the role of individual rhythmic processes in the regulation of consecutive cell cycle events. A suggestion is put forward that these rhythmic processes are transformed during subsequent development in circum-hour rhythms of some biochemical, physiological and biophysical processes discovered in the cells and organs of adult organism.

[Cell cycles in the early embryogenesis of the peled]. / Kletochnye tsikly v rannem émbriogeneze peliadi.

The dynamics of cell cycles in early embryogenesis of the peled has been studied using various methofs: determination of mitotic and mitotic phase index, of cell doubling time and of coefficient of asynchrony. The desynchronization of divisions begins at the V division after the longitudinal furrow has passed and is completed after the beginning of the cell cycle lengthening. The animal-vegetative gradient in the distribution of mitotic phases is observed at the early stages of desynchronization. The lengthening of cell cycle begins in interphase of the XI-XII cleavage and markedly accelerates from the interphase of the XII-XIII cleavage on. The methods of analysis of the cell cycles in early embryogenesis and possible factors influencing the dynamics of desynchronization are discussed.

[Relationship between the phases of mitosis in the cells of chimeric loach embryos]. / Sootnoshenie faz mitoza v kletkakh khimeruykh zarodyshei v'iuna.

The loach embryos differing in age by 0.5 tau0 (tau0--duration of the mitotic cycle during the synchronous cleavage divisions) were combined in pairs at the stage of 4--8 blastomeres to elucidate the role of intercellular relationships in the preservation of cell division synchrony during cleavage. Following the incubation during 3 tau0 the mean value of interval between mitotic phases in the pairs of combined embryos somewhat decreased but this phenomenon cannot be considered as the proof of cell division synchronization due to the intercellular relationships since it was observed to the same extent in all groups of chimaeric embryos irrespective of the degree of fusion as well as in the control embryos.

[Development of isolated loach blastoderm during cultivation in different salt media]. / Razvitie izolirovannykh blastoderm v'iuna pri kul'tivirovanii v raznykh solevykh sredakh.

The loach blastoderms were isolated from the yolk during the periods of cleavage and blastulation (5--14.5 tau0) and incubated in various isotonic saline media which differed by the content of K+ and Na+. The survival of blastoderms upon the short-term incubation (up to 60 tau0) varied insignificantly in all the media and upon the longer one (up to 120 tau0) was the maximal in the medium with isotonic content of K+ and Na+ and the minimal in the medium with the low content of K+. The cell proliferation upon incubation in the medium with the low content of K+ was inhibited when the blastoderms were isolated at the stage of 8 tau0 and suffered no changes at the stage of 14 tau0. The ability of differentiation manifested itself earlier and the percentage of differentiated embryos was higher in the media with the high content of K+. The content of K+ in the blastoderms isolated at the stage of 7 tau0 changes with its content in the incubation medium; upon isolation at the stages of 8--9 tau0 to blastoderms accumulate K+ irrespective of its content in the medium and at the stage of 10 tau0 maintain the constant level of K+. Hence, the development of isolated blastoderms depends on the content of K+ in the medium and this dependence reduces with the age.

[Desynchronization of cell division during the early development of the axoloty, loach and salmon]. / Desinkhronizatsiia kletochnykh delenii v rannem razvitii aksolotlia, v'iuna i lososia.

Patterns of a relative measure of asynchrony R of the cell population have been studied by means of a mathematical model of the kinetics of cell population which allows to follow the distribution of cells by the mitotic cycle phases in time. The application of the criterion R for the analysis of the patterns of desynchronization of cell divisions in the early embryogenesis of axolotl, loach and salmon has shown, that, unlike the smooth change of the asynchrony measure in the model populations with one constant factor desynchronization, the desynchronization in the species in question proceeds step-wise and runs to 3 steps. The problem of relationship between desynchronization and cytoplasmic segregation, decrease of electric coupling among cells and rearrangement of cell cycle is discussed. It was shown that the latter might occur in different species at a different degree of desynchronization.

[Obtaining chimeric embryos of groundling for study of the role of cellular interactions in early development]. / Poluchenie khimernykh zarodyshei v'iuna dlia issledovaniia roli kletochnykh vzaimodeistvii v rannem razvitii

A methos of production of chimaeric embryos of the loach by parabiosis of whole embryos and a whole embryo and an isolated blastodisc is proposed. The parabiosis was shown to be possible between the embryos of both the same and different ages during cleavage and blastulation. The relation between the frequency of parabiosis and the age of embryos and temperature was studied. An electric coupling is established between the cells of parabionts, similar by its value to that between the cells of each parabiont. The interrelations of cells of chimaeric embryos are considered as a model for studying the role of cell interactions during embryogenesis.