PubMed Health⌕ Search

Biomedical subjects

T A Timofeeva

Publications and source records attributed to T A Timofeeva.

33 records · Page 2Linked to original sources
PubMedDate not supplied

[Identification of the protease-binding domain in the N-terminal region of the influenza A virus matrix protein M1].

A region responsible for protease binding by influenza virus (Flu) matrix protein M1 was identified. Trypsin binding was attributed to the N-terminal 9-kDa fragment obtained by hydrolyzing M1 with formic acid. The binding was inhibited by monoclonal antibodies (mAb) to the N-terminal moiety and by antiserum to region 21-45 of M1, whereas mAb to the middle and C-terminal regions had no effect. Thus, the protease-binding domain (PBD) was mapped to the N-terminal moiety of M1.

Amino Acid Sequence↗
PubMedDate not supplied

[Certain problems of the taxonomy of monogeneans of the order Dactylogyridea (Platyhelminthes: Monogenea)].

Different taxonomic problems of the Dactylogyridea Bychowsky, 1937 are discussed. From the recent point of view, all old genera need a careful revision. Taxa of higher ranks should be analysed taking into account their host phylogeny and zoogeography. The order Tetraonchidea Bychovsky should be disband and all its families should be moved to the Dactylogyridea. The aberrant families Montchadskyellidae and Anoplodiscidae also belong to the Dactylogyridea. Dactylogyrideans are most similar to the primitive monogeneans.

Animals↗
PubMedDate not supplied

[Proboscis worm, Echinorhynchus gadi (Zoega) from a relict cod of Lake Mogil'noye].

Data on the extensiveness and intensity of infection of Kildin island cod with Echinorhynchus gadi in various seasons are given. E. gadi was proved to have a one-year life cycle and Gammarus duebeni as an intermediate host in the lake. A change of the parasite generations occurs in late summer--autumn. A high extensiveness (100%) and intensity of Kildin cod infection with E. gadi depends on the feeding habits (monophagy) and narrow distribution range of the host. Infection intensity is directly correlated with the fish age. Selfregulation of the parasite quantity in the host's intenstine is an important factor affecting the existence of E. gadi population in Lake Mogilnoye.

Acanthocephala↗
PubMedDate not supplied

[Origin and evolution of the hamuli in the monogeneans].

The hypothesis of the origin and evolution of the hamuli in monogeneans is proposed. It is suggested that the hamuli originated as the adult attachment organs of protomonogeneans inhabited the gills of the first vertebrates. Primarily they were represented by two lateral pairs of large hooks disposed anterior to the larval haptor. The fundamental direction in the evolution of monogeneans was the concentration of all attachment structures on the growing haptor. It the course of this evolutionary process, the hamuli onchoblasts migrated to the haptor, in which they had reached the position in the hind part of the haptor. The neotenic evolution of the Dactylogyridea and Gyrodactyloidea resulted in the forming new hamuli pairs. The hooks of opposite sides of the haptor are joined in a single complex within each side by the transverse plates (bars). So the presence of 4 hamuli is plesiomorphy for all the monogeneans and the presence of the transverse bars and new hamuli pairs are apomorphy for the Dactylogyridea and Gyrodactyloidea, whose evolution was linked with that of the Teleostei. The origin of the new hamuli pairs and transverse bars in the Dactylogyridea and Gyrodactyloidea appears to be a convergence.

Animals↗
PubMedDate not supplied

[Ecological approach to the problem of monophyly of Neodermata (Platyhelminthes)].

The ecological scenario of the evolution of main branches of Neodermata is described. The first neodermateans (= promonogeneans) were parasites of the gill lamellae of Paleozoic jawless vertebrates, which were microphagous suspension-feeding animals. The main apomorphic characters of the primary neodermateans are neodermis, cercomer (posterior hooked attachment organ) and swimming infective larva. All subsequent evolution of Neodermata was related with their acquisition new niches in hosts, which were intensively diverging in that time adapting to new food types and conquering new ecological niches. The acquisition of new microhabitats was accompanied by the development of morphological diversity in Neodermata especially in a structure of attachment and genital organs. Trematoda, Cestoda and Polyopisthocotylea comprise specialized evolutionary lineages and Monopisthocotylea is a basal taxon. Polyopisthocotylea is specialized to the blood feeding on fish gills. The common ancestors of the Trematoda and Cestoda inhabited walls of gills and pharyngeal cavities, from where they penetrated the digestive tract. The aspidogastridean multiloculate hold fast appears to be a highly specialized attachment organ of the monogenean ancestor, which inhabited muscular pharyngeal walls of Paleozoic vertebrates. The loss of cercomer hooks probably took place when mollusk-hosts have been involved in the aspidogastridean life cycle. The extinction of many chondrichthiean groups and progress of small plankton fishes (Teleostei) has led to the appearance Digenea. New vertebrate hosts needed a new infestation type and the cercaria appeared. Parthenogenesis has been developed in stages living in mollusks to counterbalance the loss of individuals at two transmission stages in the digenean cycle; this was resulted in a strong specificity to mollusk-host. Evolutionary tendencies of Trematoda and Cestoda show noticeable similarities.

Animals↗
PubMedDate not supplied

[Legal and social aspects of voluntary medical insurance].

The structure and functions of voluntary medical insurance (VMI) as observed in Orenburg Region are analyzed in the paper. The held marketing research pointed at problematic aspects of VMI as well as at short-comings in information support; besides, potential sectors of the market of medical services were defined, which are rendered on the basis of VMI contracts--they should be considered in the development of complex and individual VMI programs for the purpose of meeting, as full as possible, the demands of potential consumers as well as for the purpose of optimizing the financial and price policy of insurance medical organizations (IMO) in the market etc. Data that were obtained in the course of complex multi-field research served as a basis for elaborating advanced programs for the promotion of VMI in the territory of Orenburg Region as well as for working out proposals targeted at optimizing the VMI performance in the market of medical services.

Adult↗
PubMedDate not supplied

[Longevity of marine cystophorous cercariae in the environment].

Experiments were conducted on the duration of life in sea water of three species of cystophorous cercariae from the Barents sea. The expenditure of reserve nutritive substances (glycogene) in the process of the vital activity of cercariae was followed. The life duration of cystophorous cercariae is considerably longer than that cited in literature for other groups of cercariae that is associated with their morphological and biological peculiarities.

Animals↗