700 research outputs found

    Can ovarian infertility be treated with bone marrow- or ovary-derived germ cells?

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    A year ago, reproductive biologists and general public were astonished with evidence reported by Johnson et al. in Nature 428:145 that mammalian ovaries possess persisting large germline stem cells, which allegedly enable follicular renewal in adult females. Recently, the same research group declared such view obscure, and reported that mammalian oocytes originate from putative germ cells in bone marrow and are distributed by peripheral blood to the ovaries (Cell 122:303). While neglecting available data on the germ cell origin from the ovarian surface epithelium (OSE) in adult mouse and human females and complexity of follicular renewal in humans, the authors widely extrapolated their observations on formation of allogeneic oocytes after bone marrow (or blood) transplantation in ovaries of adult mice treated with cytostatics to clinical implications in the public media. Yet, the resulting outcome that such allogeneic oocytes may enable the propagation of ovarian cycles is a poor alleviation for the women with ovarian infertility. Women lacking primary follicles, or carrying follicles with low quality eggs persisting in aging ovaries, are not concerned about the lack of menstrual cycles or ovarian steroids, but about virtually no chance of having genetically related children. Johnson et al. also reported that the germ cell formation in bone marrow disappears in ovariectomized mice. Such observation, however, raises solid doubts on the bone marrow origin of oocytes. Since germ cells developing from the OSE cells of adult human ovaries during periodical follicular renewal are known to enter blood vessels in order to enable formation of primary follicles at distant ovarian sites, they also contaminate peripheral blood and hence bone marrow. Better knowledge on the complexity of follicular renewal in humans and exploration of a potential of human OSE cells to produce new oocytes in vitro are essential for novel approaches to the autologous treatment of premature ovarian failure and age induced ovarian infertility

    Reproductive Biology and Endocrinology – First year anniversary

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    First paragraph (this article has no abstract) One year after launch, Reproductive Biology and Endocrinology has been evaluated as one of the most successful BioMed Central Independent journals. Out of 185 submitted manuscripts, 146 articles have been published to date; 77 are Research articles, three Debates, two Editorials, two Hypotheses and 62 Reviews. An Open Access policy attracts both the authors and the readers

    Abnormal expression of p27kip1 protein in levator ani muscle of aging women with pelvic floor disorders – a relationship to the cellular differentiation and degeneration

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    BACKGROUND: Pelvic floor disorders affect almost 50% of aging women. An important role in the pelvic floor support belongs to the levator ani muscle. The p27/kip1 (p27) protein, multifunctional cyclin-dependent kinase inhibitor, shows changing expression in differentiating skeletal muscle cells during development, and relatively high levels of p27 RNA were detected in the normal human skeletal muscles. METHODS: Biopsy samples of levator ani muscle were obtained from 22 symptomatic patients with stress urinary incontinence, pelvic organ prolapse, and overlaps (age range 38–74), and nine asymptomatic women (age 31–49). Cryostat sections were investigated for p27 protein expression and type I (slow twitch) and type II (fast twitch) fibers. RESULTS: All fibers exhibited strong plasma membrane (and nuclear) p27 protein expression. cytoplasmic p27 expression was virtually absent in asymptomatic women. In perimenopausal symptomatic patients (ages 38–55), muscle fibers showed hypertrophy and moderate cytoplasmic p27 staining accompanied by diminution of type II fibers. Older symptomatic patients (ages 57–74) showed cytoplasmic p27 overexpression accompanied by shrinking, cytoplasmic vacuolization and fragmentation of muscle cells. The plasma membrane and cytoplasmic p27 expression was not unique to the muscle cells. Under certain circumstances, it was also detected in other cell types (epithelium of ectocervix and luteal cells). CONCLUSIONS: This is the first report on the unusual (plasma membrane and cytoplasmic) expression of p27 protein in normal and abnormal human striated muscle cells in vivo. Our data indicate that pelvic floor disorders are in perimenopausal patients associated with an appearance of moderate cytoplasmic p27 expression, accompanying hypertrophy and transition of type II into type I fibers. The patients in advanced postmenopause show shrinking and fragmentation of muscle fibers associated with strong cytoplasmic p27 expression

    Publish in Reproductive Biology and Endocrinology – Article processing charges are only paid by those who can afford it

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    Editorial Electronic journals are the basis of a world of purely electronic scientific communication. Just imagine, no more bookshelves and mountains of disorganized paperwork, no more late nights organizing and searching for articles of interest. For most active research-oriented students and scientists this is already a reality, or will be in the near future. Although most \u27top ranked\u27 traditional journals now offer web access to recent publications, and to less or more of their archives, not everyone has the luxury of access through their university, or has his/her subscription paid for, or can afford to pay US $30–35 for an electronic reprint. Traditionally, journals generated their revenue from individual subscribers, private and/or state owned institutions, page charges from authors, and charges for color illustrations. Consequently, the traditional science publishing industry limited access to scientific publications to scientists in the developed countries while, in many cases, leaving the rest of the world unattended

    Reinstatement of "germinal epithelium" of the ovary

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    BACKGROUND: The existing dogma that the former term ovarian "germinal epithelium" resulted from a mistaken belief that it could give rise to new germ cells is now strongly challenged. DISCUSSION: Two years ago, a research group of the University of Tennessee led by Antonin Bukovsky successfully demonstrated the oogenic process from the human ovarian covering epithelium now commonly called the ovarian surface epithelium. They showed the new oocyte with zona pellucida and granulosa cells, both originated from the surface epithelium arising from mesenchymal cells in the tunica albuginea, and stressed that the human ovary could form primary follicles throughout the reproductive period. This gives a big impact not only to the field of reproductive medicine, but also to the oncologic area. The surface epithelium is regarded as the major source of ovarian cancers, and most of the neoplasms exhibit the histology resembling müllerian epithelia. Since the differentiating capability of the surface epithelium has now expanded, the histologic range of the neoplasms in this category may extend to include both germ cell tumors and sex cord-stromal cell tumors. SUMMARY: Since the oogenic capability of ovarian surface cells has been proven, it is now believed that the oocytes can originate from them. The term "germinal epithelium", hence, might reasonably be reinstated

    Oogenesis in cultures derived from adult human ovaries

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    Ten years ago, we reported that in adult human females the ovarian surface epithelium (OSE) is a source of germ cells. Recently, we also demonstrated that new primary follicles are formed by assembly of oocytes with nests of primitive granulosa cells in the ovarian cortex. The components of the new primary follicles, primitive granulosa and germ cells, differentiated sequentially from the OSE, which arises from cytokeratin positive mesenchymal progenitor cells residing in the ovarian tunica albuginea. In the present study, we investigated the possibility that the oocytes and granulosa cells may differentiate in cultures derived from adult human ovaries. Cells were scrapped from the surface of ovaries and cultured for 5 to 6 days, in the presence or absence of estrogenic stimuli [phenol red (PhR)]. The OSE cells cultured in the medium without PhR differentiated into small (15 micron) cells of granulosa phenotype, and epithelial, neural, and mesenchymal type cells. In contrast, OSE cells cultured in the presence of PhR differentiated directly into large (180 micron) cells of the oocyte phenotype. Such cells exhibited germinal vesicle breakdown, expulsion of the polar body, and surface expression of zona pellucida proteins, i.e. characteristics of secondary oocytes. These in vitro studies confirm our in vivo observations that in adult human ovaries, the OSE is a bipotent source of oocytes and granulosa cells. Development of numerous mature oocytes from adult ovarian stem cells in vitro offers new strategies for the egg preservation, IVF utilization, and treatment of female infertility. In addition, other clinical applications aiming to utilize stem cells, and basic stem cell research as well, may employ totipotent embryonic stem cells developing from fertilized oocytes

    Conception of creativity-based method of foreign language communication learning in agrarian university

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    This article is devoted to the analyses and the creation of creativity-based method of foreign speech in non-linguistic university of agrarian training area. The aim of the given article is to create the more effective way of learning foreign speech in agrarian university which includes creative thinking usage. The author of the article gives the detailed analyses of foreign speech learning process issues in non-linguistic agrarian university. The author of the article developed the training curriculum of creativity-based method of foreign speech learning process in agrarian university. The methodical algorithm, developed by the author of the article, gives the detailed analysis of creative thinking implementation in practice for future agricultural specialists. Creativity-based exercises’ system, developed by the author of the article, includes creativity-based drills and creativity-based communicative tasks which provide parallel development both creative thinking and foreign speech skills of agrarian training area, necessary for communication for special purposes in agrarian universities. The article describes different modern viewpoints and concept variants of creative thinking implementation in learning process by different leading specialists in creative thinking methodology. The given article represents the better variant of foreign speaking learning technique in non-linguistic agrarian university based on consideration of creative thinking as foreign language learning terminology category and its introduction to foreign language learning process in non-linguistic agrarian training area

    Creative thinking method of foreign language communication learning in agrarian university

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    The present article is devoted to the analysis and development of the creativity-based method of teaching foreign-language in agrarian higher education institution. The aim of the article is to create a method for teaching foreign-language in agrarian higher education institution, including the consideration of creative thinking development as a means and technology of foreign-language communication skills development. The article provides a detailed analysis of oral communication teaching in a non-language university. The author of the article has developed a course of oral communication training for students of agrarian specialties with the use of a creative-based method of teaching. The article presents the principles and methodological algorithm of teaching methods, the criteria for estimating the level of creativity of students and the complex of exercises in teaching oral foreign language speech with the use of creative teaching methods. The present article is an attempt to develop an original technology based on the consideration of creative thinking as a basic methodological category and its introduction in the process of teaching foreign languages to the non-language profile. The teaching model presented by the author of the article can be applied in the process of teaching foreign language oral speech to students of agrarian universities
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