Aspectos qualitativos e quantitativos da atresia durante a foliculogênese em mamíferos

During ovarian foliculogenesis, about 99.9% of follicles die by the follicle atresia process. The atresia process can occur via degeneration or apoptosis. This process compromises all the follicle development stages, with antral follicles being those most affected. On the other hand, the preantral follicles are more residents, since their slow metabolic rate, as well as the reduced number and layers of somatic cells, granulosa and/or thecal cells. Although preantral follicles are less affected by the atresia process, when the event occurs, we can classify it in two ways, type I or type II degenerated follicles. In the type I degeneration the oocyte is the most compromised compartment, showing the picnotic nuclei, although its granulosa cells presented well organized and no picnosis. Already in the type II degeneration, the follicles presented shrunken in the oocyte, and swollen, disorganization and no adhered granulosa cells from the basal membrane and oocyte. It is important to highlight that type I degeneration is the most common in primordial and primary follicles, while in secondary follicles present more type II degeneration, which means that the as follicle evolve, type II degeneration is more frequent. Considering all the aspects related here, this literature review will address aspects related to the folliculogenesis and the process of follicle atresia, as well as substances that induce atresia during in vitro and in vivofolliculogenesis and methods and parameters for analyzing atresia in ovarian follicles. This is due to the need to develop more efficient ovarian follicle recovery protocols, which can prevent this great follicular loss and optimizing the possibilities of use of these biological materials in the future.Durante a foliculogênese ovariana, cerca de 99,9% dos folículos morrem pelo processo de atresia folicular. O processo de atresia pode ocorrer pelas vias degenerativa ou apoptótica. Este processo compromete todos os estágios de desenvolvimento folicular, sendo os folículos antrais os mais afetados. Por outro lado, os folículos pré-antrais são mais resistentes, em função de sua menor taxa metabólica, bem como do número reduzido de células e camadas de células somáticas, células da granulosa e/ou da teca. Embora folículos pré-antrais sejam menos afetados pelo processo de atresia, quando este evento ocorre, pode-se classificá-lo de duas formas, degeneração do tipo I e degeneração do tipo II. Na degeneração do tipo I, o oócito é o compartimento mais comprometido, apresentando núcleo picnótico, embora suas células da granulosa apresentem-se bem organizadas e sem picnose nuclear. Já na degeneração do tipo II, os folículos apresentam oócito retraído e células da granulosa edemaciadas, desorganizadas e sem aderência à membrana basal e ao oócito. É importante destacar que a degeneração do tipo I é mais comum em folículos primordiais e primários, enquanto folículos secundários apresentam mais degeneração do tipo II, ou seja, a medida que os folículos evoluem, a degeneração do tipo II é mais frequente. Considerando todos os aspectos aqui relacionados, essa revisão de literatura abordará aspectos relacionados aos processos de foliculogênese e atresia folicular, bem como as substâncias que induzem a atresia durante a foliculogenesein vitro e in vivo e, ainda, os métodos e parâmetros para análise da atresia em folículos ovarianos. Isto se deve a necessidade de desenvolvimento de protocolos mais eficientes de recuperação dos folículos ovarianos, prevenindo essa grande perda folicular e otimizando as possibilidades de utilização desses materiais biológicos no futuro

Ядерна енергетика і наслідки Чорнобильської катастрофи

Автори статті переконливо доводять пріоритетність ядерної енергетики над усіма іншими способами отримання енергії для існування і розвитку нашої техногенної цивілізації. Серед основних причин, що стоять на заваді розвитку ядерної енергетики в Україні, вони називають радіофобію, брак фінансів, незацікавленість профільного відомства в реалізації державної екологічної програми поводження з РАВ. Запропоновано вибудувати інфраструктуру вітчизняної ядерної енергетики у вигляді замкнутого циклу — від видобутку урану, його збагачення, виготовлення ТВЕЛів тощо аж до захоронення РАВ.Authors of the article provide convincing evidences of nuclear power engineering priority over the other methods of energy production for existence and development of our technogenic civilization. Radiophobia, lack of funds, disinterest of subject agency to implement the state environment program on radioactive wastes management are stated among the main reasons preventing development of nuclear power engineering in Ukraine. It is proposed to build up the infrastructure of home nuclear power engineering in the form of closed-loop cycle – from uranium output, concentration, fuel element production, etc until radioactive wastes disposal

Efeito da proteína morfogenética óssea 7 (BMP-7) para a sobrevivência in vitro de folículos préantrais caprino

O presente trabalho foi conduzido de modo a se verificar o efeito de diferentes concentrações da BMP-7 no desenvolvimento in vitro de folículos pré-antrais caprinos. Fragmentos de tecido cortical ovariano caprino foram cultivados por 1 ou 7 dias em Minimum Essential Medium (MEM+) suplementado com diferentes concentrações de BMP-7 (1, 10, 50 ou 100ng/ml). Os fragmentos não cultivados ou aqueles cultivados por 1 ou 7 dias foram processados para histologia clássica e microscopia eletrônica de transmissão (TEM), sendo avaliados parâmetros morfológicos indicativos de viabilidade, ativação e crescimento. Os resultados mostraram que o percentual de folículos morfologicamente normais diminuiu significativamente em todos os tratamentos quando comparados ao controle, exceto na concentração de 1ng/ml por 1 dia de cultivo. Já no D7 todos os tratamentos reduziram significativamente os percentuais de folículos morfologicamente normais. Utilizando 10ng/ml de BMP-7 foi observado um aumento significativo no diâmetro folicular quando comparados os diferentes períodos de cultivo. Não houve influência das demais concentrações de BMP-7 quando avaliados além do diâmetro folicular o diâmetro oocitário. A análise por TEM confirmou a integridade ultra-estrutural nos folículos após 7 dias de cultivo com 1ng/ml de BMP-7 . Em conclusão, o BMP-7 em baixas concentrações pode melhorar a sobrevivência e o crescimento durante o cultivo in vitro de folículos pré-antrais caprinos.This study was conducted in order to verify the effect of different concentrations of BMP-7 in the in vitro survival and development of caprine preantral follicles. Fragments of caprine ovarian cortical tissue were cultured for 1 or 7 days in Minimum Essential Medium (MEM+) supplemented with different concentrations of BMP-7 (1, 10, 50 or 100ng/ml). Noncultured fragments or those cultured for 1 or 7 days were processed for classical histology and transmission electron microscopy (TEM). Parameters such as follicular survival, activation and growth were evaluated. The results showed that, after 1 or 7 days of culture, the percentage of morphologically normal follicles was significantly reduced in all treatments when compared with fresh control, except at 1ng/ml of BMP-7 for 1 day. In addition, the concentration of 10ng/ml of BMP-7 significantly increases follicular diameter from day 1 to 7 of culture. There was no influence of the other concentrations of BMP-7 regarding to the follicular and oocyte diameter. Ultrastructure studies confirmed follicular integrity after 7 days of culture in 1ng/ml BMP-7. In conclusion, small concentrations of BMP-7 can improve the survival and growth of caprine preantral follicles during in vitro culture

Morphologic, viability and ultrastructural analysis of vitrified sheep preantral follicles enclosed in ovarian tissue

The main objective was to compare the efficiency of vitrification techniques and solutions on the preservation of morphology, ultrastructure and viability of sheep preantral follicles enclosed in ovarian tissue fragments. The fragments were cryopreserved by using macrotube vitrification (MTV), solid-surface vitrification (SSV) or conventional vitrification (CV). These techniques were combined with one of the six solutions containing 6 M ethylene glycol (EG) and with or without sucrose (SUC) (0.25 or 0.50 M) and with or without fetal calf serum (FCS) (10%). After one week, samples were warmed and histological analysis was performed, showing that the percentage of normal follicles after CV (66.20 ± 8.87%) using a solution containing 6 M EG, 0.25 M SUC and 10% FCS (vitrification solution 4 – VS4) was similar to fresh control (79.40 ± 7.83%), MTV (53.40 ± 10.60%) and SSV (56.75 ± 15.33%), all of them with the same vitrification solution (P 0.05). As the decrease of viability in non-vitrified follicles at day 2 was similar to the decrease of MTV/VS4 in the same time, follicle viability at day 2 is not affected by MTV/VS4. In conclusion, using the experimental conditions of the present study, an efficient solution (VS4: 6 M EG, 0.25 M SUC and 10% FCS) and technique (MTV) were successfully used to vitrify ovine ovarian tissue

AVALIAÇÃO DA FERTILIDADE DE RATOS Wistar SUBMETIDOS A TRATAMENTO CRÔNICO COM DECANOATO DE NANDROLONA: Dados preliminares

The search for the ideal body has been making people appeal increasingly to surgical intervention and medicine which can accelerate the aesthetic transformations that are so desired. Among these medicines, Anabolic-androgenic steroids (AAS) is being used, specially Nandrolone Decanoate (DECA), which has more anabolic than androgenic effects. However, it is not known at which point of the use of AAS can comprise fertility of male users. In this way, the objective of the present study was to evaluate the effects of chronic administration of doses of Nandrolone Decanoate in male Wistar rat fertility. For such a matter was used 20 rats Wistar, which 16 were males and 4 females, adults, with 8 weeks old, weighing 250 to 350g. Males were divided into two groups: Control and DECA group. Based on the data preliminarily obtained, even though observing some macroscopics abnormalities in the testicles of rats treated with DECA, such as testicular atrophy, apparently these steroids do not affect the reproductive male health significatively at the point of comprising the capacity of fertilization.A busca pelo corpo ideal tem feito com que as pessoas recorram cada vez mais à intervenção cirúrgica e à medicina que possam acelerar as tão desejadas transformações estéticas. Dentre esses medicamentos, estão sendo utilizados os esteróides anabólicos androgênicos (EAA), especialmente o Decanoato de Nandrolona (DECA), que possui efeitos mais anabólicos do que androgênicos. No entanto, não se sabe em que ponto do uso de AAS pode comprometer a fertilidade dos usuários do sexo masculino. Desta forma, o objetivo do presente estudo foi avaliar os efeitos da administração crônica de doses de Decanoato de Nandrolona na fertilidade de ratos Wistar machos. Para tal foram utilizados 20 ratos Wistar, sendo 16 machos e 4 fêmeas, adultos, com 8 semanas de idade, pesando 250 a 350g. Os machos foram divididos em dois grupos: grupo controle e grupo DECA. Com base nos dados obtidos preliminarmente, mesmo observando algumas anormalidades macroscópicas nos testículos de ratos tratados com DECA, como atrofia testicular, aparentemente esses esteróides não afetam a saúde reprodutiva masculina de forma significativa a ponto de comprometer a capacidade de fertilização

Effect of sequential medium on in vitro culture of goat ovarian cortical tissue

A sequential medium was evaluated on the survival, activation and growth rates of caprine preantral follicles submitted to a long-term culture period, aiming to establish an ideal in vitro culture system. Ovarian fragments were cultured for 16 days in α-MEM+ alone or supplemented with hormones (GH and/or FSH) added sequentially on different days of culture. Ovarian fragments were cultured in the first (days 0–8) and second (days 8–16) halves of the culture period, generating 10 treatments: α-MEM+/α-MEM+, FSH/FSH, FSH/GH, FSH/FSH + GH, GH/GH, GH/FSH, GH/FSH + GH, FSH + GH/FSH + GH, FSH + GH/FSH and FSH + GH/GH. Follicle morphology, viability and ultrastructure were analyzed. After day 1 of culture, FSH treatments maintained the percentage of normal follicles similar to the fresh control. At day 16 of culture, the treatment FSH/GH showed the highest (P < 0.05) percentage of normal follicles. The ultrastructure of follicles was preserved in the fresh control and FSH/GH treatment. Follicles cultured with FSH/GH had a higher (P < 0.05) viability than α-MEM+; however the viability was lower (P < 0.05) when compared to the fresh control. The FSH/GH treatment showed the highest (P < 0.05) percentage of follicular activation and secondary follicle formation and produced the largest (P < 0.05) mean follicular diameter after 16 days of culture. In conclusion, a sequential medium supplemented with FSH followed by GH during a long-term culture maintains the survival, viability and ultrastructure of goat preantral follicles, and promotes activation and secondary follicles

Interaction between ascorbic acid and follicle-stimulating hormone maintains follicular viability after long-term in vitro culture of caprine preantral follicles

This study evaluates the effects of ascorbic acid and its interaction with follicle-stimulating hormone (FSH) on the morphology, activation, and in vitro growth of caprine preantral follicles. Ovarian fragments were cultured for 1, 7, or 14 d in minimum essential medium (MEM) containing ascorbic acid (50 or 100 μg/mL), FSH (50 ng/mL), or both of these substances. Ovarian tissue that was either fresh (control) or cultured for 1, 7, or 14 d was processed for histological and ultrastructural evaluation. The results showed that after 14 d of culture, medium supplemented with 50 μg/mL of ascorbic acid alone or combined with FSH showed higher rates of follicular survival compared with MEM. After 7 d of culture, FSH, ascorbic acid at 50 μg/mL with or without FSH, and ascorbic acid at 100 μg/mL increased the percentage of follicular activation compared to fresh control. In addition, FSH alone significantly increased the percentage of growing follicles after 14 d. The combination of 50 μg/mL of ascorbic acid and FSH promoted a significant increase in oocyte and follicular diameter after 7 d of culture. Ultrastructural and fluorescent analysis confirmed the integrity of follicles cultured with 50 μg/mL of ascorbic acid and FSH after 14 d. In conclusion, the combination of 50 μg/mL of ascorbic acid and FSH maintained follicular integrity and promoted follicular activation and growth after long-term in vitro culture of caprine preantral follicles

A Proteína Morfogenética Óssea-6 (BMP-6) induz a atresia em folículos primordiais caprinos cultivados in vitro

O presente estudo investigou os efeitos da proteína morfogenética óssea-6 (BMP-6) no desenvolvimento in vitro de folículos primordiais caprinos. Amostras de córtex ovariano de cabras foram cultivados por 1 ou 7 dias em Meio Essencial Mínimo (meio controle) suplementado com diferentes concentrações de BMP-6. As taxas de sobrevivência, ativação e crescimento foram avaliadas por histologia clássica e microscopia eletrônica de transmissão (MET). Após 7 dias de cultivo, a análise histológica demonstrou que a BMP-6 aumentou o percentual de folículos primordiais degenerados no dia 7 quando comparados ao controle fresco (D0). Além disso, houve um aumento significativo do diâmetro folicular e oocitário em ambos os períodos de cultivo em todos os tratamentos na presença de BMP-6. Com a progressão do cultivo do dia 1 para o dia 7, nos tratamentos com 1 ou 50ng/ml de BMP-6, foi observado um aumento significativo no diâmetro folicular. Entretanto, contrário ao observado no meio controle, a MET revelou que os folículos cultivados nesses tratamentos apresentavam sinais evidentes de atresia. Em conclusão, esse estudo demonstrou que a BMP-6 afeta negativamente a sobrevivência e a ultra-estrutura de folículos primordiais caprinos.This study investigated the effects of bone morphogenetic protein 6 (BMP-6) on in vitro primordial follicle development in goats. Samples of goat ovarian cortex were cultured in vitro for 1 or 7 days in Minimum Essential Medium (control medium) supplemented with different concentrations of BMP-6. Follicle survival, activation and growth were evaluated through histology and transmission electron microscopy (TEM). After 7 days of culture, histological analysis demonstrated that BMP-6 enhanced the percentages of atretic primordial follicles when compared to fresh control (day 0). Nevertheless, BMP-6 increased follicular and oocyte diameter during both culture periods. As the culture period progressed from day 1 to day 7, a significant increase in follicle diameter was observed with 1 or 50ng/ml BMP-6. However, on the contrary to that observed with the control medium TEM revealed that follicles cultured for up to 7 days with 1 or 50ng/ml BMP-6 had evident signs of atresia. In conclusion, this study demonstrated that BMP-6 negatively affects the survival and ultrastructure of goat primordial follicles