1,720,972 research outputs found
New experimental model for basic research in stem cell field
No full textThe great interest in these findings is due to the promising possibility to use MSC in tissue engineering and gene therapy thanksto their plasticity and availability.
Recently a subpopulation of luteinized granulosa cells (GC) derived from infertile patients during their IVF procedures showed mesenchymal stem characteristics and multipotency.I n our recent study a heterogeneous cell population were isolated from human ovarian follicular fluid (FF cells) and cultivated in minimal medium conditions without any growth factors, including leukemia-inhibiting factor. FF cells showed a different morphology, such as fibroblastic, epithelial and also neuronal shape. In particular, the cells with characteristics similar to fibroblasts expressed many specific antigens of mesenchymal stem cells (i.e. CD90, CD44, CD105, CD73) and were negative for haematopoietic and epithelial markers (CD34, CD45, cytokeratins). We confirmed the multipotency of a subset of granulosa cells by in vitro differentiation studies (e.g. osteogenic, chondrogenic and adipogenic differentiation).Therefore we propose follicular fluid cells as a cheap biological experimental model for basic research in stem cells fields thanks to their clonogenic capacity, multipotency and availability without any growth factor addiction too.FF cells could be a good model not only to study biocompatibility of engineering scaffold, but also to investigate the effect induced by mechanical conditioning
Heterogeneous cell population derived from human ovarian follicular liquid: morphological studies and molecular screening.
No full textThe origin of oocytes and primary follicles in ovaries of adult mammalian females is still a matter of dispute (1). The components of new primary follicles, primitive granu-losa and germ cells, differentiate sequentially and de novo from mesenchymal progeni-tor cells residing in the ovarian tunica albuginea (TA). It appears that mesenchymal progenitor cells contribute to the generation of epithelial cells similar to granulosa cells (GCs). The multipotency of a subset of granulosa cells was also established by in vitro differentiation into other cell types (2). Up to now, luteinizing GCs were considered to be terminally differentiated, unavoidably becoming apoptotic a few days after ovulation. Previously, we have provided evidence for the existence of putative stem cells derived from human ovarian follicular liquid collected after routine procedures for in vitro fertili-zation techniques (3). These cells grow in minimal medium condition, without any growth factor (i.e. LIF), that is considered essential according to other procedures (4). Using immunocytochemistry and flow cytometry we showed that these cells are posi-tive for several mesenchymal stemness markers, including CD90, CD73, CD44, CD105. However, morphological analysis revealed a heterogeneous cell population, with cells displaying a fibroblast-like, epithelial-like and neural-like shapes. These ob-servations are also supported by the identification of cells expressing specific neural markers, such as neurofilaments and PGP9.5, in addition to vimentin and cytocheratin positive cells. All these data are suggestive of the presence of different cell populations in follicular fluids.
To verify this hypothesis we select a panel of markers specific for the different cell populations previously identified and we plan a molecular screening to follow their ex-pression in the follicular fluid derived cells at different times of minimal culture condi-tions in vitro. Bone marrow derived MSCs were used as a control. For each sample we performed semiquantitative RT-PCR experiments normalizing the cDNAs used as templates on the basis of the number of pseudo-mesenchymal cells morphologically identified in the sample. For this purpose OCT-4 was selected as a stem marker to fol-low the mesenchymal stem cell population, while FSH-R was used to identify granu-losa derived cells; CNTF and beta-3-tubuline were used to discriminate between neu-ral and neuronal cells populations; epithelial and hematopoietic cells were followed us-ing cytokeratin (CK8 and CK10) and CD45 markers, respectively. GAPDH and β-actin specific primers were used on all samples for normalization.
Here we compare the results of this molecular screening with the previously ob-tained immunocytochemical and morphological data to confirm the presence of these different cytotypes in the samples purified from the follicular liquid and their persis-tence, loss or amplification at different times of in vitro minimal culture conditions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Myeloperoxidase and lactoferrin expression in semen fluid: Novel markers of male infertility risk?
No full textResearch Question: Infections and/or inflammation processes of male genital tract are highly prevalent and often associated with risk of infertility. These conditions represent a possible cause of leukocytospermia, which is still under debate. Leukocytes are key-factors to reactive oxygen species (ROS) production and the increase of ROS in semen fluid is associated with the worsening of semen parameters. At present, there are not appropriate andrological tests to identify asymptomatic inflammatory conditions when the amount of leukocytes is in the normal range. Design: We studied the innate immunity profile of myeloperoxidase and lactoferrin (MPO/LAC) proteins expressed in the semen fluid of 39 men evaluated for couple infertility, in the absence of leukocytospermia. Results: The presence of both MPO and LAC proteins was associated with a decrease of sperm concentration and of progressive/total motility, whereas the increase of MPO-/LAC + indicated a worse sperm morphology. It is worth to report the predictive potential of MPO+/LAC + pattern (above 4.36 %) as a biological marker to distinguish normozoospermic from pathological patients. Conclusion: Our findings indicate MPO/LAC analysis as a potential diagnostic tool to identify asymptomatic conditions eventually related to male infertility, even when the number of leukocytes in semen fluid is below 1 million/mL
Calprotectin as a novel diagnostic approach to screen male infertility risk: A pilot study
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
New source of multipotent mesenchymal cells for tissue engineering studies waste human ovarian follicular liquid.
No full textBiological effects of ultrasound stimulus on cells derived from human ovarian follicular liquid
No full textLow-Intensity Pulsed Ultrasound Stimulus (LIPUS) accelerates the bone fracture healing in animal models and in clinical studies. In this work, according to the literature, we have chosen the mesenchymal stem cells (MSCs) as precursors of bony tissue, in particular the MSCs derived from the human ovarian follicular liquid (FL), and we have investigated the effects of ultrasounds on their proliferation. We tested two different durations of ultrasound stimulus (2 and 5 min) and compared these data to the control without ultrasound treatment. To quantify the proliferation of these putative MSCs, we used the BrdU incorporation assay: in comparison with the control, the results showed that 5 min of ultrasound stimulus significantly increased the percentage number of cells in intensive proliferative activity; on the other hand, there was no significant difference using 2 min of stimulation, hypothetically because the transmitted energy was not sufficient to stimulate the cells and to consequently enhance their proliferation. In conclusion, the effects of LIPUS on putative MSCs derived from ovarian follicular liquid show potential developments in biotech or medical applications
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