989 resultados para ovarian tissue


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This study was undertaken to compare cryotolerance, in terms of viability and resumption of meiosis after warming and culture (24 and 48 h), of ex situ (isolated) and in situ (enclosed in the ovarian tissue) feline cumulusoocyte complexes (COCs) vitrified with DAP 213 (2 M DMSO, 1 M acetamide, 3 M propylene glycol) in cryotubes or Cryotop method. Ovaries were harvested from 49 pubertal queens. of each pair of ovaries, one was dissected to release COCs randomly divided into three groups: fresh COCs (control), ex situ COCs vitrified with DAP 213 and Cryotop. The cortex of the other ovary was sectioned into small fragments (approximately 1.5 mm3) and randomly assigned to be vitrified by DAP 213 or Cryotop. After warming, ex situ and in situ (retrieved form vitrified ovarian tissue) COCs were matured in vitro. Viability of oocytes was highly preserved after warming and culture in all treatments. Proportions of oocytes surrounded by complete layers of viable cumulus cells were remarkably decreased (p < 0.00001) in both vitrification procedures compared to fresh oocytes. Resumption of meiosis occurred in all treatments. After 24 h of culture, results were similar in ex situ and in situ vitrified oocytes regardless of the vitrification protocol used (range 29-40%), albeit lower (p < 0.05) than those of fresh oocytes (65.8%). After 48 h of culture, ex situ oocytes vitrified with Cryotop achieved the rates of meiosis resumption similar to fresh oocytes (53.8% vs 67.5%; p > 0.05) and ex situ and in situ oocytes vitrified with DAP 213 showed similar rates of resumption of meiosis. These findings demonstrated that DAP 213 and Cryotop preserve the viability of ex situ and in situ oocytes, but cumulus cells are highly susceptible to vitrification. However, the capability to resume meiosis evidences that feline immature oocytes vitrified as isolated or enclosed in the ovarian cortex have comparable cryotolerance.

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In vivo production of viral biopesticides is the major source of viral insecticides currently in the marketplace. However, this system presents limitations during production scale-up. For the Spodoptera frugiperda nucleopolyhedrovirus (SfMNPV), the insect used for replication has cannibalistic characteristics, thus production is even more difficult. Insect cells are commonly used for in vitro baculovirus production. Most of these cell lines are derived from Lepidoptera species. The Sf21 cell line is derived from Spodoptera frugiperda caterpillar ovarian tissue, and its clonal isolate Sf9 has been used for biopesticide production due to its ease of growth in suspension cultures. In this work, the in vitro production capabilities of a Brazilian SfMNPV isolate obtained from cornfields was evaluated. Comparison of polyhedra production was carried out using both Sf21 and Sf9 cells, based on volumetric and specific yields. Both cell lines were cultivated in Hyclone medium supplemented with different fetal bovine serum concentrations (2,5 and 5%). The best results were obtained using Sf9 cells supplemented with 5% serum. These results were further confirmed quantitively through kinetic parameter estimation for both cells lines and different serum concentrations. After seven successive passages, this system still presented high specific polyhedra production

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Caesalpinia echinata and C ferrea var. ferrea have different seed behaviours and seed and fruit types. Comparison of the seed ontogeny and anatomy partly explained the differences in seed behaviour between these two species of Brazilian legumes; some differences were also related to fruit development. The seed coat in C. ferrea consisted of two layers of osteosclereids, as well as macrosclereids and fibres, to form a typical legume seed coat, whereas C. echinata had only macrosclereids and fibres. In C. echinata, the developing seed coat had paracytic stomata, a feature rarely found in legume seeds. These seed coat features may account for the low longevity of C. echinata seeds. The embryogeny was similar in both species, with no differences in the relationship between embryo growth and seed growth. The seeds of both species behaved as typical endospermic seeds, despite their different morphological classification (exendospermic orthodox seeds were described for C. echinata and endospermic orthodox seeds for C. ferrea). Embryo growth in C. ferrea accelerated when the sclerenchyma of the pericarp was developing, whereas embryonic growth in C. echinata was associated with the conclusion of spine and secretory reservoir development in the pericarp. Other features observed included an endothelial layer that secreted mucilage in both species, a nucellar summit, which grew up into the micropyle, and a placental obturator that connected the ovarian tissue to the ovule in C. ferrea. (C) 2004 the Linnean Society of London.

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Objective: Compare the cryoprotectants Dimethyl Sulphoxide (DMSO), Ethylene Glycol (EG) and their association for cryopreservation of sheep ovarian cortex. Methodology: Fragments collected from ovaries were divided into 3 parts. 1. One part from sample was destined for analysis of fresh material. 2. The second part was incubated with solution of freezing having 1,5M EG or 1,5M DMSO or 1,5MEG + 1,5M DMSO and washed for dilution of the cryoprotectants. 3. The third part was submitted to cryopreservation using the same cryoprotectans (EG 1,5M; DMSO 1,5M and EG + DMSO 1,5M) and cryopreserved. In all groups, one part of sample was submitted to pre-antral follicles isolation and the remainder was destined to ultra-structural analysis. Results: After isolation of fresh primordial follicles (control), the percentage of viable follicles was 78,9%. The percentage of viable follicles only exposed to cryoprotectants 1,5M EG, 1,5M DMSO and 1,5M EG + 1,5M DMSO was 77,1%, 68,4% and 60,7% respectively. After cryopreservation were 75%, 60% and 55,6% respectively. Ultra-structural analysis of the primordial follicles derived from fresh ovarian fragments or from fragments just exposed to the cryoprotectants showed similar morphology. However, in frozen samples, alterations of mitochondria were observed in all groups. Despite this, the integrity of the remained organelles was preserved in follicles cryopreserved with EG, while that in others groups (DMSO and association) an excess of vacuolizaton in cytoplasm of oocytes and swelling of nuclear membrane was observed indicating degeneration. Conclusion: The Ehilene Glycol seems to be the cryoprotector more adequated for cryopreservation of sheep ovarian tissue.

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The objective of this study was to evaluate the effects of adding ascorbic acid to the media for in vitro culture of cattle ovarian fragments and to determine their effects on growth activation and viability of early-stage follicles. The ovarian cortex was divided into small fragments; one fragment was immediately fixed (control) and the other fragments were cultured in minimum essential medium (MEM) supplemented or not with various doses of ascorbic acid. Ovarian tissue was processed for histology, transmission electron microscopy (TEM) and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA). Compared with control fragments, the percentage of primordial follicles was reduced (p < 0.05) and the percentage of growing follicles had increased (p < 0.05) in cultured cortical fragments, independent of the tested medium or incubation time. Furthermore, compared with control tissue, culture of ovarian cortex for 8 days reduced the percentages of healthy, viable follicles (p < 0.05), but not when cultures were supplemented with 25, 50 or 100 μg/ml of ascorbic acid. Ultrastructural and immunohistochemical analysis of 8 day cultured ovarian cortical fragments, however, showed the integrity and viability of follicles only when fragments were cultured in presence of 50 μg/ml of ascorbic acid. In conclusion, this study demonstrated that addition of ascorbic acid to MEM at a concentration of 50 μg/ml not only stimulates the activation of 8 day in vitro cultured cattle primordial follicles and subsequent growth of activated follicles, but also safeguards the viability of these early-stage follicles. © 2012 Copyright Cambridge University Press.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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O objetivo desse trabalho foi analisar a ativação e o crescimento de folículos préantrais de Sapajus apella, submetidos a um sistema de cultivo in vitro em curto-prazo. Nesse sentido, dois experimentos foram realizados neste trabalho. Experimento I: exposição à fresco e à crioprotetores de biopsias de fragmentos do córtex ovariano. Ambos os fragmentos ovarianos foram submetidos à extração total de RNA e síntese de cDNA. Após a amplificação do cDNA por PCR em tempo-real (RT-PCR), os software GeNorm, bestkeeper e Normfinder foram usados para avaliar a estabilidade dos genes GAPDH (glyceraldehyde-2-phosphate dehydrogenase), HPRT1 (hypoxanthine phosphoribosyltransferase 1) e TBP (TATA-binding protein). Experimento II: o tecido do córtex ovariano de quatro fêmeas foi oletado e dividido em nove pedaços de 1 mm³. Um fragmento ovariano (grupo controle) foi imediatamente dividido em dois pedaços, os quais foram destinados para análise da viabilidade ou por RT-PCR. Os 8 fragmentos restantes foram individualmente cultivados in vitro em um meio constituído de TCM suplementado com 100 ng/mL EGF (T1), com adição de 10 μM de BME (T2), 100 ng/mL de BMP4 (T3), 25 IU de PMSG (T4), 10 μM de BME e 100 ng/mL de BMP4 (T5), 10 μM de BME, 25 IU de PMSG (T6), 100 ng/mL de BMP4, 25 IU de PMSG (T7) ou 10 μM de BME, 100 ng/mL de BMP4, 25 IU de PMSG (T8). Os resultados demonstraram que no tecido do córtex ovariano de S. apella, os genes HPRT1 e TBP foram os mais apropriados como genes de referência, podendo ser usados como parâmetro para normalizar dados em estudos futuros. Ao contrário, o GAPDH se apresentou como menos estável dos genes de referencia testados. Após o cultivo in vitro, todos os tratamentos alcançaram percentuais similares da viabilidade de folículos pré-antrais. O tecido ovariano cultivado na presença de GF+BME/BMP4/PMSG resultou no aumento da taxa de ativação e crescimento folicular, assim como no aumento da expressão de AMH, BMP15 e GDF9, genes conhecidos como indicadores específicos de desenvolvimento folicular. Dessa forma, o HPRT1 e TBP são os genes de referência mais estáveis, na exposição à crioprotetores, a fresco e no o cultivo de tecidos de córtex ovariano de S. apella. Os folículos pré-antrais são capazes de desenvolverem-se in vitro quando cultivados em meio suplementado com PMSG, BME e BMP4. A viabilidade folicular, entretanto, permaneceu independentemente do meio de cultivo in vitro e o uso de fatores de crescimento, como marcadores de desenvolvimento folicular, foi crucial para identificar o melhor meio de cultivo in vitro.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Medicina Veterinária - FCAV

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Although there are several studies on morphogenesis in Teleostei, until now there is no research describing the role of the basement membrane in the establishment of the germinal epithelium during gonadal differentiation in Characiformes. In attempt to study these events that result in the formation of ovarian and testicular structures, gonads of Gymnocorymbus ternetzi were prepared for light microscopy. During gonadal development in G. ternetzi, all individuals first developed ovarian tissue. The undifferentiated gonad was formed by somatic cells (SC) and primordial germ cells (PGCs). After successive mitosis, the PGCs became oogonia, which entered into meiosis originating oocytes. An interstitial tissue developed. In half of the individuals, presumptive female, prefollicle cells synthesized a basement membrane around oocyte forming a follicle. Along the ventral region of the ovary, the tissue invaginated to form the ovigerous lamellae, bordered by the germinal epithelium. Stroma developed and the follicle complexes were formed. The gonadal aromatase was detected in interstitial cells in the early steps of the gonadal differentiation in both sexes. In another half of the individuals, presumptive male, there was no synthesis of basement membrane. The interstitium was invaded by numerous granulocytes. Pre-Leydig cells proliferated. Apoptotic oocytes were observed and afterward degenerated. Spermatogonia appeared near the degenerating oocytes and associated to SCs, forming testicular tubules. Germinal epithelium developed and the basement membrane was synthesized. Concomitantly, there was decrease of the gonadal aromatase and increase in the 3β-HSD enzyme expression. Thus, the testis was organized on an ovary previously developed, constituting an indirect gonochoristic differentiation.

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Gonadal maturation of cobia, Rachycentron canadum, was evaluated by examining 508 specimens from its recreational fishery. Specimens were collected off southeast Louisiana to northwest Florida by hook-and-line during February through October 1987-1991. Fork lengths (FL) of these fish ranged from 580-1,530 mm, with corresponding weights of 2.0-43.5 kg. The female:male ratio was 1:0.37. Using a combination of oocyte size frequency and histological assessment of many of the fish, we determined that females were ripe from May through September, with atretic oocytes occurring in some fish from July through October. Degenerating hydrated oocytes in July and October and the presence of resting ovaries in July suggest two major spawning periods; however, monthly gonosomatic indices peaking in May, followed by a steady decline, do not support that finding. Ovaries were placed into undeveloped, early developing, mid-developing, or late developing categories based upon oocyte size-frequency distributions. Developing ovaries had two or three modes of oocytes larger than 30 μm. Batch fecundity was estimated to be 2.6×106 - 1.91×108 oocytes, depending on the size of fish/ovaries. The smallest female with oocytes exhibiting vitellogenesis was 834 mm FL. This fish was 2 years old based its otolith evaluation. The smallest male with an abundance of spermatozoa in its testes was 640 mm FL and 1 year old based on otolith evaluation; smaller males were not examined. Females larger than 840 mm FL had vitellogenic oocytes in March and April. A few fish still had vitellogenic oocytes in early October, but none did by late October. When Gilson’s fluid was used to assess ovarian tissue, the fresh weight of the tissue was reduced by 20% after being stored for 3 months. The diameter of oocytes shrunk about 25% in Gilson’s fluid which was 11% less than those fixed in formalin, embedded in paraffin, and sectioned. Tissue sections from specific individuals, each demonstrating a variety of different developmental stages, were similar regardless of whether they were obtained from the anterior, middle, or posterior portion of either ovary.

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Introduzione L’efficacia dei chemio/radioterapici ha aumentato notevolmente l’aspettativa di vita delle pazienti oncologiche, tuttavia, questi trattamenti possono compromettere la funzionalità ovarica. La crioconservazione di tessuto ovarico, con il successivo reimpianto, ha lo scopo di preservare la fertilità delle pazienti a rischio di fallimento ovarico precoce. Scopo dello studio Definire la migliore procedura di crioconservazione e reimpianto in grado di ottenere la neovascolarizzazione del tessuto reimpiantato nel minor tempo possibile al fine di diminuire la perdita follicolare causata dall’ischemia durante la procedura. Materiali e metodi Per ciascuna paziente (3) le biopsie ovariche, sono state prelevate laparoscopicamente e crioconservate secondo il protocollo di congelamento lento/scongelamento rapido. Campioni di corticale ovarica sono stati processati per l’analisi istologica, ultrastrutturale, immuistochimica e confocale per valutare la preservazione morfologiaca del tessuto. Le fettine di corticale ovarica sono state scongelate e reimpiantate ortotopicamente (2), nelle ovaia e in due tasche peritoneali, o eterotopicamente (1), in due tasche create nel sottocute sovrapubico. Risultati Le analisi di microscopia hanno mostrato il mantenimento di una discreta morfologia dello stroma, e dei vasi criopreservati e un lieve ma non significativo danneggiamento dei follicoli scongelati. Tutte le pazienti hanno mostrato la ripresa della funzionalità endocrina rispettivamente dopo 2/4 mesi dal reimpianto. Il color-doppler, inoltre ha rivelato un significativo aumento della vascolarizzazione ovarica rispetto alla quasi totale assenza di vascolarizzazione prima del reimpianto, quando le pazienti mostravano una conclamata menopausa. Conclusioni Lo studio ha confermato la ripresa della vascolarizzazione dell’ovaio in seguito a reimpianto avascolare di fettine di corticale, senza l’impiego di fattori esogeni o meccanici aggiuntivi, in tempi concordanti con i dati della letteratura. I risultati sono incoraggianti e l’avanzare degli studi e della ricerca potranno contribuire allo sviluppo di nuove metodologie di reimpianto che possano avere un successo clinico ed una sicurezza superiori a quelle finora ottenute.

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Especially young women with cancer face rising survival rates due to remarkable progress in oncologic therapies. Preserving fertility is a major concern for both patients and their next of kin. Well established reproductive technologies such as cryopreservation of fertilized oocytes after in vitro fertilization already make fertility preservation possible for some patients. This review is dedicated to the emerging techniques that are becoming widely accepted for fertility preservation in young women and girls with cancer, such as auto transplantation of ovarian tissue cryopreservation and in vitro maturation (IVM) of either oocytes or follicles. First results are encouraging. But some challenges still have to be tackled in order for these novel technologies to be routinely employed with the aim of successful fertility preservation.