Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
R. cient. eletr. Med. Vet. ; 30jan. 2018. graf
Artigo em Português | VETINDEX | ID: vti-738096

Resumo

O acúmulo de placa bacteriana na superfície dos dentes é um dos principais fatores que contribui para o aparecimento de doença periodontal. Esta por sua vez, além de gerar inflamação e de infecção tecidual, provocador e eventual perda de dente e podendo acarretar distúrbios sistêmicos. Objetivou-se avaliar a incidência de placa bacteriana em cães de acordo com os hábitos alimentares. Foi calculada a área do dente e da placa bacteriana após impregnação com evidenciador. Animais alimentados com comida úmida apresentaram maior acometimento por placa bacteriana, permitindo concluir que a alimentação influencia diretamente no aparecimento de placa bacteriana.(AU)


The accumulation of bacterial plaque on the surface of the teeth is one of the main factors that contributes to the appearance of periodontal disease. This in turn, generate inflammation and tissue infection, causes pain and eventual loss of tooth and can lead to systemic disorders. The aim of this study was to evaluate the incidence of bacterial plaque in dogs according to eating habits. The area of the tooth and plaque were calculated after impregnation with evidentiary solution. Animals fed with soft food presented greater impairment by bacterial plaque, allowing to conclude that feeding directly influences the appearance of bacterial plaque.(AU)


Assuntos
Animais , Cães , Placa Dentária/veterinária , Ração Animal , Arco Dental , Periodontite/veterinária , Gengivite/veterinária , Comportamento Alimentar , Doenças Periodontais/veterinária
2.
Artigo em Português | VETINDEX | ID: biblio-1494277

Resumo

O acúmulo de placa bacteriana na superfície dos dentes é um dos principais fatores que contribui para o aparecimento de doença periodontal. Esta por sua vez, além de gerar inflamação e de infecção tecidual, provocador e eventual perda de dente e podendo acarretar distúrbios sistêmicos. Objetivou-se avaliar a incidência de placa bacteriana em cães de acordo com os hábitos alimentares. Foi calculada a área do dente e da placa bacteriana após impregnação com evidenciador. Animais alimentados com comida úmida apresentaram maior acometimento por placa bacteriana, permitindo concluir que a alimentação influencia diretamente no aparecimento de placa bacteriana.


The accumulation of bacterial plaque on the surface of the teeth is one of the main factors that contributes to the appearance of periodontal disease. This in turn, generate inflammation and tissue infection, causes pain and eventual loss of tooth and can lead to systemic disorders. The aim of this study was to evaluate the incidence of bacterial plaque in dogs according to eating habits. The area of the tooth and plaque were calculated after impregnation with evidentiary solution. Animals fed with soft food presented greater impairment by bacterial plaque, allowing to conclude that feeding directly influences the appearance of bacterial plaque.


Assuntos
Animais , Cães , Arco Dental , Comportamento Alimentar , Gengivite/veterinária , Periodontite/veterinária , Placa Dentária/veterinária , Ração Animal , Doenças Periodontais/veterinária
3.
Acta Vet. Brasilica ; 7(4): 261-271, 2013. ilus
Artigo em Português | VETINDEX | ID: biblio-1453444

Resumo

Todas as células possuem mecanismos específicos para defender-se das agressões e condições estressantes imposta pelo ambiente. As proteínas de choque térmico (Hsp), além de auxiliar na síntese e dobramento de diversas outras proteínas em condições normais, representam um dos mecanismos mais conservados ativado em respostas a diversos tipos de estresse. Neste contexto, esta revisão aborda aspectos relacionados à descoberta e estrutura das proteínas Hsp, com destaque para a atuação da família Hsp70 na resposta celular ao estresse, interação com as vias apoptóticas, bem como a influência da criopreservação sobre a expressão destas proteínas.


All cells have specific mechanisms to defend itself from aggression and stressful conditions imposed by the environment. The heat shock proteins (Hsp), besides aiding in the synthesis and folding of several other normally represent one of the most conserved mechanisms activated in response to various types of stress. In this context, this review discusses aspects related to the discovery and structure of Hsp proteins, high lighting the role of Hsp70 in the cellular response to stress, interaction with apoptotic pathways, as well as the influence of cryopreservation on the expression of these proteins.


Assuntos
Apoptose , Criopreservação , /fisiologia , /ultraestrutura
4.
Acta Vet. bras. ; 7(4): 261-271, 2013. ilus
Artigo em Português | VETINDEX | ID: vti-21470

Resumo

Todas as células possuem mecanismos específicos para defender-se das agressões e condições estressantes imposta pelo ambiente. As proteínas de choque térmico (Hsp), além de auxiliar na síntese e dobramento de diversas outras proteínas em condições normais, representam um dos mecanismos mais conservados ativado em respostas a diversos tipos de estresse. Neste contexto, esta revisão aborda aspectos relacionados à descoberta e estrutura das proteínas Hsp, com destaque para a atuação da família Hsp70 na resposta celular ao estresse, interação com as vias apoptóticas, bem como a influência da criopreservação sobre a expressão destas proteínas.(AU)


All cells have specific mechanisms to defend itself from aggression and stressful conditions imposed by the environment. The heat shock proteins (Hsp), besides aiding in the synthesis and folding of several other normally represent one of the most conserved mechanisms activated in response to various types of stress. In this context, this review discusses aspects related to the discovery and structure of Hsp proteins, high lighting the role of Hsp70 in the cellular response to stress, interaction with apoptotic pathways, as well as the influence of cryopreservation on the expression of these proteins.(AU)


Assuntos
Proteínas de Choque Térmico HSP70/fisiologia , Proteínas de Choque Térmico HSP70/ultraestrutura , Criopreservação , Apoptose
5.
Acta sci. vet. (Impr.) ; 41: Pub. 1150, 2013. ilus, tab
Artigo em Inglês | VETINDEX | ID: biblio-1371962

Resumo

Background: The main advantage of the cryopreservation of ovarian fragments is a thinner tissue, which facilitates the penetration of cryoprotective agents, but the size of tissue may not be a limiting factor in achieving a successful cryopreservation of the ovarian tissue. This information is highly significant considering that the cryopreservation of hemi-ovary or whole ovary may preserve the entire or major part of the contingent of primordial follicles of ovarian fragments. Therefore, the aim of this study was to evaluate the vitrification of different dimensions goat ovarian tissue on the follicular morphology, viability, diameter, and the stromal cell density. Materials, Methods & Results: The ovarian tissue was vitrified as fragment, hemi-ovary, or whole ovary, and after warming, the preantral follicles were examined by trypan blue dye exclusion test and histological analysis. Preantral follicles incubated with trypan blue were considered viable if the oocyte and granulosa cells remained unstained. Preantral follicles were classified as morphologically normal only when they contained intact oocyte and granulosa cells. The follicular diameter was measured considering the major and minor axes of each follicle; the average of these 2 measurements was used to determine the diameter of each follicle. Ovarian stroma cells density was evaluated by calculating the number of stromal cell in an area of 100 × 100 µm. There was no difference in the percentage of morphologically normal and viable follicles after vitrification compared to the control (fresh tissue), regardless of the dimension of the vitrified ovarian tissue (P > 0.05). In addition, there were no differences in the follicular diameter after ovarian tissue vitrification, independent of the dimension (P > 0.05). However, after vitrifi cation, a decrease in the ovarian stromal cells density was observed (P < 0.05). This reduction was more intense after the vitrification of the hemi-ovary and whole ovary, compared to the ovarian fragment vitrification (P < 0.05). Discussion: No differences were observed in the percentages of morphologically normal and viable follicles from fresh or vitrified ovarian tissue (fragment, hemi-ovary, and whole ovary). These results are in agreement with other reports which no showed morphological changes after cryopreservation of the whole ovary, and the ovarian fragments. With respect to follicular diameter, only the diameter of the preantral follicles in ovarian tissue vitrified as hemi-ovary was similar to that observed in the fresh control, in the present study. The results demonstrate that fragments and whole ovary vitrification had greater cell dehydration (exposure to VS) and/or less cell rehydration (VS removal), showing that minor adjustments are needed in the protocols of cryoprotectants addition or removal from the fragments and the whole ovary. However, this reduction in follicular diameter did not appear to have affected the follicular architecture or cellular viability, which were maintained in all dimensions of ovarian tissue undergoing vitrifi cation. A reduction in the stromal cell density was observed, especially in the hemi-ovary and whole ovary as compared to the ovarian fragment. Previous reports have shown that ovarian stromal cells are responsible for the production of essential substances for follicular development and these substances are fundamental for follicles development and these cells tend to be more sensitive to cryopreservation procedure than ovarian follicles. In conclusion, the maintenance of follicular morphology and viability demonstrated that vitrification of goat ovarian tissue under the conditions applied in this study can be performed in any dimension of ovarian tissue (fragment, hemi-ovary, and whole ovary).


Assuntos
Animais , Feminino , Ovário/citologia , Ruminantes/genética , Criopreservação/veterinária , Células Estromais
6.
Acta sci. vet. (Impr.) ; 40(3): Pub. 1046, 2012. ilus
Artigo em Português | VETINDEX | ID: biblio-1373606

Resumo

Background: Cryopreservation is a biotech successfully employed in female gametes and embryos. This technique is of great importance for propagation of genetic material from animals with high-value livestock as well as to preserve the fertility of women undergoing cancer treatments. However, low temperatures can result in damage to different cellular compartments and organelles. This damage culminates in reduced viability, since they affect cell metabolism. Review: Cryopreservation consists of maintenance of biological material at low temperatures, in which chemical reactions are ceased, however, allowing the cells to preserve their viability. However, the decrease of temperature and subsequent warming may result in cellular damage. These damages occur in the cell membrane, cytoplasmic organelles and the cell nucleus. It is believed that the first cell structure undergoing cryoinjury is the plasma membrane, responsible for maintaining homeostasis within the cell, and the loss of plasma membrane during the reduction temperature reported the main damage. The membrane damage due to cryopreservation appears to correlate with the reduction of thermal energy at low temperatures, thus limiting the movement of molecules through the phospholipids of lipid bilayer. Cryopreservation also alters the morphology, structure and cellular distribution of lipid droplets, reducing the survival of oocytes and embryos. The physical state changes, besides changing physicochemical properties of intracellular lipid may also result in damage to lipids associated with the cellular cytoskeleton. The interaction between cell lipid phase and components of cytoskeleton is complex and hardening of these lipids can cause deformation and disruption of cytoskeleton with consequent negative effect on cell survival and development. The disruption of cytoskeleton can also be intrinsic to change in dehydration and cellular form that follow the cryopreservation process. Among the cellular organelles, mitochondria are sensitive to cryopreservation procedures, since the formation of intracellular ice crystals considered one of the most relevant cryoinjury, leading to damage to the mitochondrial cristae and matrix. Another important organelle undergoes damage as result of cryopreservation is the endoplasmic reticulum, which change in morphology has been described after vitrification of embryos. It is also known that cryopreservation may result in fragmentation of DNA even in the absence of deformation of the cellular morphology, and that these changes can lead to delay in the development or cell death. In addition to the direct damage to double-stranded DNA, cryopreservation may trigger chromosomal abnormalities, these the aneuploidy is the most frequent and seems to compromise the developmental competence of oocytes in addition to being indicated as the main factor for the low achieve of live births. Conclusion: Cryopreservation is an important alternative for the preservation of gametes and embryos, however, the cells are subjected to unfavorable conditions that can compromise cell recovery after thawing/warming. The main cause of reduction in survival oocytes and embryos after cryopreservation appear to be related to damage in different cellular compartments and structures, which are essential for maintaining cell metabolism. Thus, it is observed the need to achieve cryopreservation protocols capable of maintaining the integrity of different cellular components.


Assuntos
Humanos , Animais , Ovário/embriologia , Preservação de Tecido/veterinária , Criopreservação/tendências , Técnicas Reprodutivas/veterinária
7.
Ciênc. Anim. (Impr.) ; 22(1): 42-54, 2012.
Artigo em Português | VETINDEX | ID: vti-14740

Resumo

A criopreservação tem sido de extrema importância para a preservação de material genético de machos e fêmeas para a utilização posterior em programas de reprodução assistida. Por essa razão, o emprego da criopreservação de oócitos inclusos em folículos ovarianos pré-antrais tem se mostrado como uma ferramenta complementar para as biotecnologias da reprodução que visam maximizar o potencial reprodutivo de animais de grande valor genético mesmo após a morte ou descarte programado. A aplicação da criopreservação de folículos pré-antrais, isolados ou inclusos no tecido ovariano, permitirá a implantação de bancos de germoplasma animal/humano, com o intuito de preservar o patrimônio genético e, consequentemente, a preservação e manutenção da fertilidade de fêmeas. Vários estudos em diferentes espécies, notadamente em humanos, têm demonstrado a retomada da função reprodutiva relatando inclusive o nascimento de crias saudáveis após transplante de tecido ovariano previamente criopreservado. No entanto, em pequenos ruminantes, especialmente em caprinos, os avanços ainda são pouco significativos. Portanto, conclui-se que mais estudos são requeridos com o objetivo de definir um protocolo (congelação lenta ou vitrificação) que garanta a viabilidade e função ovariana e folicular, normais após a descongelação/aquecimento.(AU)


Cryopreservation has been extremely important for the preservation of male and female genetic material for later use in assisted reproduction procedures. Thus, the use of cryopreservation of oocytes enclosed in preantral follicles has been shown as a complementary tool for the reproduction biotechnologies aimed at maximizing the reproductive potential of animals of great genetic value even after death, unexpected or not, as well as after planed elimination. The application of isolated or in situ preantral follicles cryopreservation, will allow salvage animal genetic resources in gene/banks animal / or even genetic human, and consequently to preserve and maintaining the female fertility. Several studies in different species, especially humans, have demonstrated the resumption of reproductive function including reporting the birth of healthy offspring after transplantation of cryopreserved ovarian tissue previously. However, in small ruminants, especially in goats, improvements are still not very significant. Therefore, it is concluded that further studies are required in order to define a protocol (slow freezing or vitrification) that ensures the viability and normal function of ovary and preantral follicles after thawing/warming.(AU)


Assuntos
Animais , Embrião de Mamíferos/anatomia & histologia , Cabras/classificação
8.
Ciênc. Anim. (Impr.) ; 22(1): 42-54, 2012.
Artigo em Português | VETINDEX | ID: biblio-1472122

Resumo

A criopreservação tem sido de extrema importância para a preservação de material genético de machos e fêmeas para a utilização posterior em programas de reprodução assistida. Por essa razão, o emprego da criopreservação de oócitos inclusos em folículos ovarianos pré-antrais tem se mostrado como uma ferramenta complementar para as biotecnologias da reprodução que visam maximizar o potencial reprodutivo de animais de grande valor genético mesmo após a morte ou descarte programado. A aplicação da criopreservação de folículos pré-antrais, isolados ou inclusos no tecido ovariano, permitirá a implantação de bancos de germoplasma animal/humano, com o intuito de preservar o patrimônio genético e, consequentemente, a preservação e manutenção da fertilidade de fêmeas. Vários estudos em diferentes espécies, notadamente em humanos, têm demonstrado a retomada da função reprodutiva relatando inclusive o nascimento de crias saudáveis após transplante de tecido ovariano previamente criopreservado. No entanto, em pequenos ruminantes, especialmente em caprinos, os avanços ainda são pouco significativos. Portanto, conclui-se que mais estudos são requeridos com o objetivo de definir um protocolo (congelação lenta ou vitrificação) que garanta a viabilidade e função ovariana e folicular, normais após a descongelação/aquecimento.


Cryopreservation has been extremely important for the preservation of male and female genetic material for later use in assisted reproduction procedures. Thus, the use of cryopreservation of oocytes enclosed in preantral follicles has been shown as a complementary tool for the reproduction biotechnologies aimed at maximizing the reproductive potential of animals of great genetic value even after death, unexpected or not, as well as after planed elimination. The application of isolated or in situ preantral follicles cryopreservation, will allow salvage animal genetic resources in gene/banks animal / or even genetic human, and consequently to preserve and maintaining the female fertility. Several studies in different species, especially humans, have demonstrated the resumption of reproductive function including reporting the birth of healthy offspring after transplantation of cryopreserved ovarian tissue previously. However, in small ruminants, especially in goats, improvements are still not very significant. Therefore, it is concluded that further studies are required in order to define a protocol (slow freezing or vitrification) that ensures the viability and normal function of ovary and preantral follicles after thawing/warming.


Assuntos
Animais , Embrião de Mamíferos/anatomia & histologia , Cabras/classificação
9.
Acta sci. vet. (Online) ; 39(4)20110000. ^f1^l12
Artigo em Português | VETINDEX | ID: vti-12343

Resumo

Background: Important advances have been made recently that clarify our understanding of the structural basis, signaling and regulation, as well as the biological role of activin in ovaries. During folliculogenesis various growth factors are produced locally in the mammalian ovary. Among these factors, activin has been a focal point in research as it has emerged as a crucial substance capable of inducing follicular development. The important actions indicate that activin has many relevant homeostatic functions in the reproduction of several species. Therefore, this review discusses the ligand protein structure, activin receptors, mechanisms of action and regulation, as well as the importance of activin on in vitro culture of preantral follicles. Review: Activin belongs to the transforming growth factor β (TGF - β) super family. It is a homodimer or heterodimer of two similar but distinct subunits (βA and βB). The dimerisation of activin subunits gives rise to three forms of activin, which are classified as, activin A (βA - βA), activin B (βB - βB) and activin AB (βA - βB). The biological activity of activin occurs through its connection with two types of cell surface receptors designated type I and type II. These receptors are represented by two isoforms, activin receptor types IA (ActR - IA), IB (ActR - IB), IIA (ActR - IIA) and IIB (ActR - IIB). Activin receptors are transmembrane proteins, composed of a ligand-binding extracellular domain, a transmembrane domain and a cytoplasmic domain with serine/threonine kinase activity. The transient activation of the receptor induces phosphorylation of protein mediators called Smads. Activation of Smad 2/3 by phosphorylation causes trimerization and hetero-oligomerization with the common Smad, Smad 4. This complex translocates to the nucleus to activating and regulating transcription of target genes. Members of another class of Smads act as negative regulators of the signal transduction pathway. Inhibitory Smad 7 can bind to type I receptors, preventing receptor–Smad 2/3 association, or by competitively binding of Smad 4, which blocks Smad intracellular translocation. In addition, within the extracellular environment, binding proteins such as follistatin and inhibin can modulate the biological activity of activin. In the ovaries of mammals specifically, activin participates in several cellular events, including cellular proliferation, differentiation, and survival, as well as assisting steroidal hormones during follicular development. Activin has been localized in the oocytes and granulosa cells of rodent, porcine, caprine and bovine follicles. Activin is also within the granulosa cells of human follicles and in the thecal layers of porcine and human. In addition, activin stimulates follicle growth in-vitro, is used in pre-antral ovine and caprine follicles and enhances growth and survival of human pre-antral follicles in vitro. Conclusion: Activin is controlled by competitive substances and a dynamic interaction between the various regulatory proteins responsible for coordinating several signaling pathways. The balance between the actions of these proteins is critical for regulation of gene expression in different structures, including pre-antral follicles. However, the nature of physiological effects of activin in the ovary is still equivocal and awaits clarification.(AU)


Assuntos
Ativinas/efeitos adversos , Inibinas/efeitos adversos , Folículo Ovariano/fisiologia , Ligantes
10.
Acta sci. vet. (Impr.) ; 39(2): 1-17, 20110000. ilus, tab
Artigo em Português | VETINDEX | ID: biblio-1456845

Resumo

Background: The application of cryopreservation in human and animal reproductive medicine has stimulated several studies about the effects of low temperatures and freezing processes on cells and tissues, in order to develop efficient protocols for gamete and embryo preservation. Moreover, cryopreservation is a fundamental tool for the establishment of animal germplasm banks, allowing the preservation of genetic material from several species and breeds or for further study and/or recovery of desirable characteristics. For the success of cryopreservation, the addition of an intracellular cryoprotectant agent in the freezing solution is indispensable. However, issues related to intracellular cryoprotectant agents used, e.g., their metabolism and potential toxicity, must be examined carefully so we can choose the cryoprotectant most suitable for a specific structure. Review: In this regard, this review introduces several aspects of cryopreservation, such as basic principles and methods used (slow freezing and vitrification), describing the fundamental steps of cryoprotectant agent’s exposure, cooling, storage, thawing or warming and removal of the cryoprotectant agent. The addition of an intracellular cryoprotectant to the freezing solution is essential, but does not guarantee the success of the cryopreservation protocol, due to its toxic effect, which requires a perfect balance between cryoprotectant concentration, temperature and exposure time to the structure which will be cryopreserved. Some studies attribute the toxicity of these agents mainly to the secondary metabolites formed when the cell resumes its activi ty and gradually begins to metabolize the cryoprotectant agent.[...]


Assuntos
Crioprotetores/análise , Folículo Ovariano , Oócitos , Criopreservação
11.
Acta sci. vet. (Impr.) ; 39(4)20110000. ^ef1, ^el12
Artigo em Português | VETINDEX | ID: biblio-1456878

Resumo

Background: Important advances have been made recently that clarify our understanding of the structural basis, signaling and regulation, as well as the biological role of activin in ovaries. During folliculogenesis various growth factors are produced locally in the mammalian ovary. Among these factors, activin has been a focal point in research as it has emerged as a crucial substance capable of inducing follicular development. The important actions indicate that activin has many relevant homeostatic functions in the reproduction of several species. Therefore, this review discusses the ligand protein structure, activin receptors, mechanisms of action and regulation, as well as the importance of activin on in vitro culture of preantral follicles. Review: Activin belongs to the transforming growth factor β (TGF - β) super family. It is a homodimer or heterodimer of two similar but distinct subunits (βA and βB). The dimerisation of activin subunits gives rise to three forms of activin, which are classified as, activin A (βA - βA), activin B (βB - βB) and activin AB (βA - βB). The biological activity of activin occurs through its connection with two types of cell surface receptors designated type I and type II. These receptors are represented by two isoforms, activin receptor types IA (ActR - IA), IB (ActR - IB), IIA (ActR - IIA) and IIB (ActR - IIB). Activin receptors are transmembrane proteins, composed of a ligand-binding extracellular domain, a transmembrane domain and a cytoplasmic domain with serine/threonine kinase activity. The transient activation of the receptor induces phosphorylation of protein mediators called Smads. Activation of Smad 2/3 by phosphorylation causes trimerization and hetero-oligomerization with the common Smad, Smad 4. This complex translocates to the nucleus to activating and regulating transcription of target genes. Members of another class of Smads act as negative regulators of the signal transduction pathway. Inhibitory Smad 7 can bind to type I receptors, preventing receptor–Smad 2/3 association, or by competitively binding of Smad 4, which blocks Smad intracellular translocation. In addition, within the extracellular environment, binding proteins such as follistatin and inhibin can modulate the biological activity of activin. In the ovaries of mammals specifically, activin participates in several cellular events, including cellular proliferation, differentiation, and survival, as well as assisting steroidal hormones during follicular development. Activin has been localized in the oocytes and granulosa cells of rodent, porcine, caprine and bovine follicles. Activin is also within the granulosa cells of human follicles and in the thecal layers of porcine and human. In addition, activin stimulates follicle growth in-vitro, is used in pre-antral ovine and caprine follicles and enhances growth and survival of human pre-antral follicles in vitro. Conclusion: Activin is controlled by competitive substances and a dynamic interaction between the various regulatory proteins responsible for coordinating several signaling pathways. The balance between the actions of these proteins is critical for regulation of gene expression in different structures, including pre-antral follicles. However, the nature of physiological effects of activin in the ovary is still equivocal and awaits clarification.


Assuntos
Ativinas/efeitos adversos , Folículo Ovariano/fisiologia , Inibinas/efeitos adversos , Ligantes
12.
Acta sci. vet. (Online) ; 39(2): 1-17, 20110000. ilus, tab
Artigo em Português | VETINDEX | ID: vti-11300

Resumo

Background: The application of cryopreservation in human and animal reproductive medicine has stimulated several studies about the effects of low temperatures and freezing processes on cells and tissues, in order to develop efficient protocols for gamete and embryo preservation. Moreover, cryopreservation is a fundamental tool for the establishment of animal germplasm banks, allowing the preservation of genetic material from several species and breeds or for further study and/or recovery of desirable characteristics. For the success of cryopreservation, the addition of an intracellular cryoprotectant agent in the freezing solution is indispensable. However, issues related to intracellular cryoprotectant agents used, e.g., their metabolism and potential toxicity, must be examined carefully so we can choose the cryoprotectant most suitable for a specific structure. Review: In this regard, this review introduces several aspects of cryopreservation, such as basic principles and methods used (slow freezing and vitrification), describing the fundamental steps of cryoprotectant agents exposure, cooling, storage, thawing or warming and removal of the cryoprotectant agent. The addition of an intracellular cryoprotectant to the freezing solution is essential, but does not guarantee the success of the cryopreservation protocol, due to its toxic effect, which requires a perfect balance between cryoprotectant concentration, temperature and exposure time to the structure which will be cryopreserved. Some studies attribute the toxicity of these agents mainly to the secondary metabolites formed when the cell resumes its activi ty and gradually begins to metabolize the cryoprotectant agent.[...](AU)


Assuntos
Crioprotetores/análise , Folículo Ovariano , Oócitos , Criopreservação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA