Assessment of fertility protection and ovarian reserve with GnRH antagonist in rats undergoing chemotherapy with cyclophosphamide

<p>Abstract</p> <p>Background</p> <p>Reproductive function following chemotherapy is of increasing importance given that survival rates are improving. We assessed whether a gonadotropin-releasing hormone antagonist (GnRHant; cetrorelix) could promote ovarian protection against damage due to chemotherapy.</p> <p>Methods</p> <p>Forty-two female Wistar rats were used in this study. Animals were divided into four groups: group I (n = 9) received placebo twice; group II (n = 12) received placebo + cyclophosphamide (CPA); group III (n = 12) received GnRHant + CPA; and group IV (n = 9) received GnRHant + placebo. After medication, the estrous cycle was studied through vaginal smears. Rats were mated, pregnancy was documented and the number of live pups evaluated. Afterwards, rat ovaries were removed and prepared for histological studies. The ovarian cross-sectional area was measured and follicles were counted.</p> <p>Results</p> <p>Cyclic changes in vaginal smears were observed in all but one animal after treatment, but group II had a significantly lower rate of animals with proestrus or estrus (p < 0.01). The offspring was markedly reduced by CPA treatment (group II, 3.00 +/- 1.33 pups vs. group I, 11.44 +/- 0.78 pups, p < 0.01) and this effect was partly reversed by pre-treatment with GnRHant (group III, 7.00 +/- 1.31 pups). The ovarian cross-sectional area was not significantly different between groups, neither was the number of individual follicle types. However, rats in Group IV had a higher total number of ovarian follicles than those in the control group (17.1 +/- 1.22 vs. 10.9 +/- 0.70, p < 0.05).</p> <p>Conclusion</p> <p>The use of a GnRHant before CPA chemotherapy provided protection of fertility.</p

Investigation of non-invasive methods for monitoring ovarian function in women

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Stem cells: Are they the answer to the puzzling etiology of endometriosis?

Endometriosis is a chronic bening disease characterizaed by the presence of abnormally located tissue resembling the endometrium with glands and stroma. This disease has a high degree of morbidity due to chronic pelvic pain and infertility. The disease is likely to be polygenic and multifactorial, but the exact pathogenic mechanisms are still not entirely clear. Recently, adult stem cells have been identified in several tissues, including the endometrium. These cells are probably involved in the regenerative ability of the endometrial cycle, and also in the pathogenesis of proliferative gynaecological diseases, such as endometriosis. The identification of stem cells in animal and human tissues is very complex and the putative stem cells are supposed to be found through several assays such as clonogenicity, label-retaining cells, “side- population” cells, undifferentiation markers, and cellular differentiation. Bone marrow-derived stem cells transplanted into humans and animals have also been identified in eutopic endometrium and endometriotic implants. This review evaluates the available evidence regarding stem/progenitor cells in the human endometrium and explores the possible involvement of these cells in the etiology of endometriosis

Avaliação da aplicabilidade da técnica de maturação in vitro de oócitos humanos e posterior fertilização Evaluation of the usefulness of the in vitro maturation technique of human oocyte and subsequent fertilization

OBJETIVO: avaliar a aplicabilidade da técnica de maturação in vitro de oócitos humanos e posterior fertilização. MÉTODOS: estudo prospectivo não randomizado descritivo realizado no período de novembro de 1999 a março de 2001 no qual foram incluídas 15 pacientes com infertilidade tubária e 20 ciclos de fertilização in vitro. Todas assinaram o termo de consentimento livre e esclarecido antes de iniciar o estudo. As pacientes tinham idade entre 18 e 32 anos incompletos, obstrução tubária como causa exclusiva de infertilidade e índice de massa corporal inferior a 25 kg/m². As pacientes receberam 300 UI de hormônio folículo estimulante (FSH) recombinante por via intramuscular no segundo dia do ciclo e doses adicionais de 150 UI no quarto e no sexto dia do ciclo. A coleta ovular foi realizada no sétimo dia do ciclo. Os oócitos foram colocados em meio TCM 199 acrescido de antibióticos, piruvato, FSH, gonadotrofina coriônica humana e soro (Serum Substitute Supplement - Irvine Scientific®). Após 48 h de cultivo, os oócitos que atingiram o estágio de metáfase II foram inseminados e os fertilizados foram transferidos. RESULTADOS: foram puncionados 144 folículos com a coleta de 67 oócitos imaturos (46,5%). Quarenta e três oócitos atingiram o estágio de metáfase II (64,2%) e foram inseminados. Destes, 30 fertilizaram e 25 embriões foram transferidos para 10 pacientes. Houve uma gravidez com nascimento de um bebê. CONCLUSÃO: concluiu-se que a técnica de maturar oócitos humanos in vitro previamente à fertilização in vitro é técnica exeqüível, capaz de gerar gravidez.<br>PURPOSE: to evaluate the usefulness of the in vitro maturation technique of human oocyte and subsequent fertilization. METHODS: this is a prospective nonrandomized, descriptive study, carried out during the period of November 1999 to March 2001, with 20 cycles of in vitro fertilization of 15 patients with tubal infertility. All signed the written informed consent before the beginning of the study. The selected patients were at least 18 and at most 32 years of age, with only tubal infertility, and body mass index less than 25 kg/m². The patients received 300 UI of recombinant follicle stimulating hormone (FSH) by intramuscular injection at the second day of the cycle and additional doses of 150 IU at the fourth and sixth days of cycle. The oocyte retrieval was performed at the seventh day of the cycle. Those oocytes classified as immature were cultured in tissue culture medium 199 (TCM-199) with antibiotics, pyruvate, FSH, human chorionic gonadotropin (hCG) and serum (serum substitute supplement - Irvine Scientific®). After 48 h of culture, the oocytes that achieved metaphase II stage were inseminated, and the fertilized ones were transferred. RESULTS: one hundred and forty-four follicles were aspirated. There were 67 (46.5%) immature retrieved oocytes and 43 (64.2%) reached the metaphase II stage and were inseminated. Thirty fertilized oocytes and 25 embryos were transferred to 10 patients. There was one pregnancy with a baby born. CONCLUSION: we conclude that to mature human oocytes in vitro before in vitro fertilization is a procedure able to achieve pregnancy

Variation in neuronal differentiation of a newly isolated mouse embryonic stem cell line : a detailed immunocytochemistry study.

Neural precursor differentiation from mouse ES (embryonic stem) cells have been demonstrated using EB (embryoid body), co-culture on stromal feeder layers, and in the absence of external inducing signals. Most of available mouse ES cell original research articles have worked with only six different cell lines. Our goals were to isolate one new mouse ES lineage, and perform a detailed immunocytochemistry study during neural differentiation, making use of an EB strategy protocol following the generation of neural progenitors, glial cells and postmitotic neurons. The dynamics of differentiation of ES cell derived neuronal precursors into differentiated glia cells and neurons were followed in vitro and correlated to exposure to specific elements of feeder medium. Morphological aspects of generated cellular types, including its immunocytochemical expression of differentiation markers were studied. Immuno-positivity against b-III tubulin, PGP and TH (tyrosine hydroxylase) was observed from stage I. Approximately 80% of cells were positive for TH at stage I. The first glial cell type appears in stage III. TH, PGP or b-III tubulin-positive cells with neuronal typical morphology only being seen in stage III when TH-positive cells corresponded to approximately 12% of total cells. Variations among other literature findings can be explained by the choice we made to use a newly isolated ES cell line. As colonies may behave differently during neuronal differentiation, it reinforces the necessity of studying original ES cell lines