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Biomedical subjects

O N Golubeva

Publications and source records attributed to O N Golubeva.

14 recordsLinked to original sources
PubMed2005

The capacity of mesenchymal stem cells for neural differentiation in vitro.

It has been shown that mesenchymal stem cells (MSCs) of bone marrow from newborn rabbits can be induced for neuronal differentiation. The epidermal growth factor (EGF) introduced in the culture at the rate of 2 ng/ml is able to promote differentiation of neurons from bone marrow mesenchymal stem cells in 27 days of cultivation. Differentiated cells were marked by monoclonal antibodies to 70 kDa neurofilaments. The data obtained show a possibility of using bone marrow stem cells in therapy of neurodegenerative diseases.

Animals↗
PubMed2003

Effects of a phasic oral contraceptive containing desogestrel on facial seborrhea and acne.

BACKGROUND: The combined oral contraceptive containing ethinylestradiol and the selective progestogen, desogestrel, in a phasic regimen (DSG-OC, Tri-merci) has been shown to reduce facial oiliness. OBJECTIVE: This study was designed to evaluate further the effects of this OC on the skin of women with facial seborrhea and mild or moderate acne. DESIGN AND METHODS: This was an open, noncomparative, bicenter study in 60 healthy Russian women, aged 18-30 years, with facial seborrhea and mild or moderate facial acne, who wished to use oral contraception. All women received the OC containing desogestrel (50/100/150 microg) and ethinylestradiol (35/30/30 microg) for three phases of 7 days followed by a 7-day pill-free interval, for six cycles. Seborrhea was assessed using the Sebutape technique, in which strips of adhesive microporous polymeric film pressed onto facial sites are used to assess sebaceous activity. Acne was assessed by counting facial lesions. Subjective evaluations of skin and hair condition, patients' feelings to them and satisfaction with the OC were made using a visual analogue scale (VAS). Assessments were made at baseline, and after one, three and six treatment cycles. RESULTS: Sebutape assessments of seborrhea were significantly improved, on the right and left cheeks, after one treatment cycle, and on the forehead after three treatment cycles. These improvements increased steadily and were much larger at the end of Cycle 6. Acne grades were significantly improved after three and six treatment cycles. VAS scores in response to questions dealing with self-esteem and self-confidence were significantly improved after three cycles and in some cases after just one cycle. The women's views of their skin and hair (greasiness) were correspondingly significantly improved. Subjective assessments indicated that after one, three and six cycles, 69%, 93% and 98%, respectively, of women were satisfied or very satisfied with the DSG-OC. CONCLUSION: In women with facial seborrhea and mild or moderate acne, the use of DSG-OC appears to improve seborrhea after just one cycle and acne grades after three cycles. These improvements are accompanied by increases in self-esteem and confidence.

Acne Vulgaris↗
PubMed2000

[Biological role of a neurotrophic factor fragment from pigment epithelium: structure-functional homology with a differentiation factor for the HL-60 cell line].

It was shown that the full-size neurotrophic factor from pigment epithelium (PEDF) induces the cell differentiation of the human promyelocyte leukemia cell line HL-60. A structural analysis of PEDF revealed in its C-terminal region a six-membered peptide fragment PEDF-(352-357) (PEDF-6) whose sequence is highly homologous to the 41-46 fragment of the active site of the human leukocyte differentiation factor HLDF (HLDF-6). The biological effect of PEDF and synthetic peptides PEDF-6 and HLDF-6 on the HL-60 cells and the early gastrula ectoderm of Xenopus laevis embryos was studied. On the basis of the structural and functional homologies of HLDF, PEDF, and their homologous peptides and the computer models of the spatial structures of the full-size PEDF and the PEDF with the C-terminal fragment split off tby the cleavage of the Leu380-Thr381 bond in the serpin loop, a hypothesis on the functional role of the serpin loop in PEDF was put forward.

Amino Acid Sequence↗
PubMed1997

Inductive capacity of living eye tissues from adult frogs.

The aim of the present work has been to demonstrate the inducing capacity of living homogenous undamaged tissues from adult frogs. Tissues from the eyes of adult frogs Xenopus laevis: retina (R), pigmented epithelium (PE), lens epithelium (LE), and the forebrain (B) as a control, were tested for their inducing capacity using early gastrula ectoderm. To exclude the possibility of ad-mixture of inducing cells in early gastrula ectoderm the transfilter induction technique was used throughout. The results show that the tissues used in the cases of most intense induction tended to induce similar cell types: both R and PE induce R + PE together with adjoining neural cells and secondary lens cells. LE induces lentoids (L) and B cells induce neuroids. In each case epidermis surrounds the explants filled with ectomesenchyme (EM) and melanophores (M). Immunofluorescence reactions clarified the nature of lens cells. This discovery indicates that cells of adult tissues continue throughout life producing substances which are able to promote the appearance of cells of the same type during development. Probably they also serve to mediate interrelations between cells of these tissues, regulating the stability of their differentiation in the adult state, as well.

Age Factors↗
PubMed1982

[Development of the structure and stability of Mauthner's neurons in Xenopus laevis tadpoles on the implantation of additional auditory vesicles].

The ultrastructure and functional changes of the Mauthner cells were studied in the X. laevis tadpoles under the conditions of the experimentally doubled source of their afferentation, an additional pair of ear vesicles. Additional afferent fibers grow from the receptors to the brain and form additional synapses on the soma of the Mauthner cells, indistinguishable by their morphology from the terminals of their own acoustic nerves. The altered interneuronal interactions lead, on one hand, to the accelerated maturation of the Mauthner cells and, on the other one, to the vacuolization of a part of the cytoplasm. The superafferentation of the Mauthner cells is characterized by a long-term marked decrease in the length of sections of the active zones of axosomatic synapses. It is suggested that this structural rearrangement provides for a marked increase in the stability of the Mauthner cells with respect to extreme natural stimulation which is noted in the tadpoles with the double vestibular system.

Animals↗
PubMed1980

The spatio-temporal framework of melanogenic induction in pigmented retinal cells of Xenopus laevis.

Using methods involving transplantation of neuroectoderm and eye rudiments between ap/ap mutants and +/+ embryos of Xenopus laevis, new aspects of melanogenic induction have been ascertained. The possibility of separate induction of a melanocyte cell type and of the product of terminal differentiation in it-melanosomes, has been demonstrated. Melanogenic induction starts at the late gastrula stage. It has an irreversible character which has been shown using the technique of double transplantation. Melanogenic factor (MgF) is produced only by the region of endomesoderm which is adjacent to eye rudiments in the course of normal development. Competence for melanogenic induction lasts till stage NF 30. Melanogenic induction appears to be species-specific; at least after transplantation of eye vesicles from ap/ap Xenopus laevis to Rana temporaria the melanoprotein synthesis cannot be switched on. L-Tyrosine, under the conditions of the experiments, is not a factor in the induction of melanogenesis.

Ambystoma mexicanum↗
PubMedDate not supplied

[Distribution of differentiation potentials and the conditions for their realization in the amphibian neuroectoderm].

The X. laevis neuroectoderm (NE) at the mid and late gastrula stages is capable to form mesoderm in vitro after its separation from mesoderm. This capacity is inherent in posterior 2/3 of NE underlied by axial mesoderm in the embryo and forming deuterencephalic and trunk regions of the brain in the normal development. The archencephalic 1/3 of NE of the late gastrula, underlied in the embryo by prechordal plate, is capable of differentiation into archencephalic regions of the brain, rather than into mesoderm. For the typical differentiation of archencephalic NE to be realized, it should be surrounded by the outer ectoderm layer. In the absence of the latter, the whole explant develops into retina and brain only. Inside the closed explants, ectomesenchyme and melanophores arise and the eye material is subdivided into retina and pigmented epithelium. The archencephalic NE, dissociated to individual cells and wrapped into epidermis, forms much more ectomesenchyme and melanophores than the usual NE explants.

Amphibians↗
PubMedDate not supplied

[Inductive effect of the eye tissues of adult clawed toads on the gastrula ectoderm].

The inducing influence of adult eye tissues on the early gastrula ectoderm was studied in vitro. Both retina and pigment epithelium induced in the early gastrula ectoderm similar spectra of cell types, including nervous tissue, retina, pigment epithelium, lentoids, ectomesenchyme, and melanophores. It is suggested that the correspondence of these cell types with those arising at a spontaneous transdifferentiation of the isolated retina and pigment epithelium cells in vitro or at the induction of the early gastrula ectoderma by archencephalic endomesoderm during the normal development can be accounted for by that in these eye cells molecular determinants appeared as a result of induction and maintaina the stability of their differentiation and their potencies to transdifferentiation in vitro being reproduced during the lifetime of these cells.

Animals↗