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Search Results: 1 - 10 of 130304 matches for " V. Lodde "
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Relationship between growth hormone concentrations in bovine oocytes and follicular fluid and oocyte developmental competence
S Modina,V Borromeo,AM Luciano,V Lodde
European Journal of Histochemistry , 2007, DOI: 10.4081/1139
Abstract: In the last few years, several works suggest that Growth Hormone (GH) is involved in follicular development and oocyte maturation. These actions may reflect endocrine roles of pituitary GH and also account for local autocrine or paracrine activities of GH produced in reproductive tissue. This study was aimed to verify whether the developmental competence of bovine female gametes might be related to ovarian GH.We evaluated the localisation and distribution of GH in the cumulus oocytes complexes (COCs) and the concentration of GH in the oocytes and in the follicular fluids (FF) from ovaries classified on the basis of the follicles number. Oocytes retrieved from ovaries with more than 10 follicles of 2 to 5 mm in diameter (High ovaries, Hi) show higher rate of maturation and blastocyst formation than those retrieved from ovaries with less than 10 follicles (Low ovaries, Lo). At the same time we measured Estrogen (E2) and Progesterone (P4) concentrations in FF, to relate oocytes quality, GH concentration and follicle health. GH localization in COCs and oocytes was performed by indirect immunofluorescence and its concentration within the ooplasm was evaluated by microspectrophotometer analysis. GH, E2 and P4 concentrations in FF were measured by an Enzyme Linked ImmunoSorbent assay (ELISA).We observed a positive, diffuse signal at cytoplasmic level in most of the cumulus cells, with no differences between COCs collected from Hi and Lo ovaries. On the contrary, GH level was significantly higher in the oocytes collected from Lo ovaries than in those recovered from Hi ovaries. Finally we found that also GH level in the FF was inversely related to the oocytes developmental capability. We suggest that the increase of GH in the oocytes and in the FF derived from Lo ovaries might be interpreted as attempt of the follicular environment to improve ovarian activity and in turn oocytes developmental competence in a autocrineparacrine manner. Moreover, E2, and P4 levels in FF suggest that, in our model, atresia processes are also involved in oocyte developmental capability and that the highest level of GH may represent a local reaction to these phenomena.
Large-scale chromatin morpho-functional changes during mammalian oocyte growth and differentiation
A.M. Luciano,V. Lodde,F. Franciosi,I. Tessaro
European Journal of Histochemistry , 2012, DOI: 10.4081/ejh.2012.e37
Abstract: Mammalian oocyte development is characterized by impressive changes in chromatin structure and function within the germinal vesicle (GV). These changes are crucial to confer the oocyte with meiotic and developmental competencies. In cow, oocytes collected from early and middle antral follicles present four patterns of chromatin configuration, from GV0 to GV3, and its progressive condensation has been related to the achievement of developmental potential. During oogenesis, follicular cells are essential for the acquisition of meiotic and developmental competencies and communicate with the oocyte by paracrine and gap junction mediated mechanisms. We recently analyzed the role of gap junction communications (GJC) on chromatin remodeling process during the specific phase of folliculogenesis that coincides with the transcriptional silencing and sequential acquisition of meiotic and developmental capabilities. Our studies demonstrated that GJC between germinal and somatic compartments plays a fundamental role in the regulation of chromatin remodeling and transcription activities during the final oocyte differentiation, throughout cAMP dependent mechanism(s).
Localization of DNA methyltransferase-1 during oocyte differentiation, in vitro maturation and early embryonic development in cow
V. Lodde,S. C. Modina,F. Franciosi,E. Zuccari
European Journal of Histochemistry , 2009, DOI: 10.4081/ejh.2009.199
Abstract: DNA methyltransferase-1 (Dnmt1) is involved in the maintenance of DNA methylation patterns and is crucial for normal mammalian development. The aim of the present study was to assess the localization of Dnmt1 in cow, during the latest phases of oocyte differentiation and during the early stages of segmentation. Dnmt1 expression and localization were assessed in oocytes according to the chromatin configuration, which in turn provides an important epigenetic mechanism for the control of global gene expression and represents a morphological marker of oocyte differentiation.We found that the initial chromatin condensation was accompanied by a slight increase in the level of global DNA methylation, as assessed by 5-methyl-cytosine immunostaining followed by laser scanning confocal microscopy analysis (LSCM). RT-PCR confirmed the presence of Dnmt1 transcripts throughout this phase of oocyte differentiation. Analogously, Dnmt1 immunodetection and LSCM indicated that the protein was always present and localized in the cytoplasm, regardless the chromatin configuration and the level of global DNA methylation. Moreover, our data indicate that while Dnmt1 is retained in the cytoplasm in metaphase II stage oocytes and zygotes, it enters the nuclei of 8-16 cell stage embryos. As suggested in mouse, the functional meaning of the presence of Dnmt1 in the bovine embryo nuclei could be the maintainement of the methylation pattern of imprinted genes. In conclusion, the present work provides useful elements for the study of Dnmt1 function during the late stage of oocyte differentiation, maturation and early embryonic development in mammals.
Expression of progesterone receptor membrane component-1 in bovine reproductive system during estrous cycle
A.M. Luciano,D. Corbani,V. Lodde,I. Tessaro
European Journal of Histochemistry , 2011, DOI: 10.4081/ejh.2011.e27
Abstract: Several reports suggest the participation of progesterone receptor membrane component 1 (PGRMC1) in progesterone signaling in the reproductive system. This study aimed at investigating the presence and localization of PGRMC1 in bovine ovary, oviduct and uterus, during the follicular and luteal phases of the estrous cycle. In the ovary, PGRMC1 has been detected in surface germinal epithelium, granulosa cells, theca cells and in the germinal vesicle of the oocytesat all stages of folliculogenesis. In the corpus luteum the expression of PGRMC1 was influenced by the stage of the estrous cycle. In the oviducts and in the uterus horns, PGRMC1 was immunolocalized in the luminal epithelium, in the muscle layer cells and in the endothelial cells. In the uterus, PGRMC1 was intensely localized also in the glandular endometrium. However, in the oviducts and in the uterus horns, the localization of PGRMC1 was independent on the stage of the estrous cycle and on whether evaluating the ipsilateral or the contralateral organ. In conclusion, the present immunohistochemical study showed that PGRMC1 is located in various compartments of the bovine female reproductive organs. With the exception of the corpora lutea, PGRMC1 localization showed similar pattern during different stage of the estrous cycle.
Cytoplasmic changes and developmental competence of bovine oocytes cryopreserved without cumulus cells
S Modina,M Beretta,V Lodde,A Lauria
European Journal of Histochemistry , 2004, DOI: 10.4081/906
Abstract: The cryopreservation of female gametes is still an open problem because of their structural sensitivity to the coolingand- freezing process and to the exposure to cryoprotectants. The present work was aimed to study the effect of vitrification on immature bovine oocytes freed of cumulus cell investment before freezing. To verify the feasibility and efficiency of denuded oocyte (DO) cryopreservation, the cytoplasmic alterations eventually induced either by cell removal or by the vitrification process were analyzed. In particular, the migration of cortical granules and Ca++ localization were studied. In addition, the localization and distribution of microtubules and microfilaments in immature fresh and vitrified DOs were evaluated. Finally, to establish whether the removal of cumulus cells influenced developmental competence, DOs were thawed after vitrification, matured in vitro and fertilized; then presumptive zygotes were cultured to reach the blastocyst stage. The results indicate that mechanical removal of cumulus cells from immature bovine oocytes does not affect their maturation competence but reduces the blastocyst rate when compared with intact cumulus oocyte complexes (COCs). The findings indicate further that the vitrification process induces changes of cytoplasmic components. However, the composition of the manipulation medium used to remove cumulus cells plays a crucial role in reducing the injuries caused by cryopreservation in both cytoplasmic and nuclear compartments. In fact, the presence of serum exerts a sort of protection, significantly improving both oocyte maturation and blastocyst rates. In conclusion, we demonstrate that denuded immature oocytes can be vitrified after cumulus cells removal and successfully develop up, after thawing, to the blastocyst stage, following in vitro maturation and fertilization.
Anthroponet: il censimento del materiale scheletrico proveniente dagli scavi della Sardegna
Marco Lodde,Elisabetta Marini
Antrocom : Online Journal of Anthropology , 2008,
Abstract:
The Role of -Choline-PET/CT-Guided Secondary Lymphadenectomy in Patients with PSA Failure after Radical Prostatectomy: Lessons Learned from Eight Cases
Thomas Martini,Roman Mayr,Emanuela Trenti,Salvatore Palermo,Evi Comploj,Armin Pycha,Maria Zywica,Michele Lodde
Advances in Urology , 2012, DOI: 10.1155/2012/601572
Abstract: Introduction. 11C-choline-PET/CT is a promising technique for detection/restaging of patients with biochemical failure (BF) after curative therapy for prostate cancer (PCA). The aim of this paper was to evaluate the PSA response in patients with BF after radical prostatectomy (RP) who underwent secondary lymphadenectomy (LAD) due to 11C-choline-PET/CT findings. Material and Methods. Eight patients with BF and positive lymph nodes in 11C-choline-PET/CT after RP were retrospectively included in the study. Extended LAD until the common iliac arteries was performed in all patients. Results. Six of 8 patients had histologically proven lymph node metastases. Four patients showed an initial PSA reduction after LAD, and in 4 patients the PSA increased. Two of the latter had no histological lymph node metastases. Conclusions. Because 50% of our patients showed an initial PSA response, our data suggest that positive 11C-choline-PET/CT after RP and BF could help to select patients that could benefit from secondary LAD. 1. Introduction The incidence of recurrent disease after the initial curative treatment of local PCA ranges from 30 to 50% after RP [1, 2] and up to 80% after extracorporal radiotherapy [3]. An increasing PSA is the most certain indicator for relapse, but it does not always help in differentiating between local recurrence and systemic spread of the disease [4]. PSA kinetics and imaging techniques play an important role in the diagnostic of PCA recurrence after primary treatment. Positron emission tomography/computed tomography with choline tracer (11C-choline-PET/CT) has emerged as a promising technique for restaging patients with BF. Tumor cells are known to have a higher turnover of essential cell membrane components, such as phosphatidylcholine, [5]. After uptake by tumor cells, radioactive choline is phosphorylated in high concentration and built into the cell membrane and can be recognized by PET [6]. PCA or its metastases can be detected by 11C-choline-PET/CT [7]. The aim of this paper was to retrospectively evaluate the PSA response after secondary LAD in patients with a BF and positive lymph nodes in 11C-choline-PET/CT after RP. 2. Material and Methods Eight consecutive patients between 2009 and 2011 with BF and positive lymph nodes in 11C-choline-PET/CT were retrospectively included in the study. Because of a PCA, 5 patients had initially undergone a retropubic RP with a pelvic LAD and 3 a perineal RP without LAD. Local recurrence was excluded by transrectal ultrasound and digital rectal examination. All patients were informed of the pure
Nonsmooth Optimization Algorithms in Some Problems of Fracture Dynamics  [PDF]
V. V. Zozulya
Intelligent Information Management (IIM) , 2010, DOI: 10.4236/iim.2010.211073
Abstract: Mathematical statement of elastodynamic contact problem for cracked body with considering unilateral restrictions and friction of the crack faces is done in classical and weak forms. Different variational formulations of unilateral contact problems with friction based on boundary variational principle are considered. Nonsmooth optimization algorithms of Udzawa’s type for solution of unilateral contact problem with friction have been developed. Convergence of the proposed algorithms has been studied numerically.
Precessing Ball Solitons as Self-Organizing Systems during a Phase Transition in a Ferromagnet  [PDF]
V. V. Nietz
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.410A3010
Abstract:

Precessing ball solitons (PBS) in a ferromagnet during the first order phase transition is induced by a magnetic field directed along the axis of anisotropy, while the action of the periodic field perpendicular to the main magnetic field has been analyzed. Under these conditions, the characteristics of arising equilibrium PBS are uniquely determined by the frequency of the periodic field, but the solitons with other frequencies are impossible. For such structure, the entropy increase connected with dissipation is compensated by the decrease of the entropy due to the external periodic field. It is shown that the equilibrium PBS are essentially the “self-organizing systems” that can arise spotaneously in a metastable state of ferromagnet.

Movement of Self-Organizing Solitons in Ferromagnet  [PDF]
V. V. Nietz
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.610155
Abstract: Precessing ball solitons (PBS) in a ferromagnet during the first order phase transition induced by a magnetic field directed along the axis of anisotropy, while the additional action of high-frequency field perpendicular to the main magnetic field, are analyzed. It is shown that the spatial motion of solitons, associated with thermal fluctuations in the crystal, does not destroy the equilibrium of self-organized PBS.
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