RESUMO
Osteopontin (OPN) is a multifunctional phosphoprotein that has been linked to fertility in bulls. However, the exact mechanism by which OPN contributes to fertilisation is yet unknown. The biotechnological use of OPN in bovine reproduction is promising but some gaps remain unfilled. The present work aimed: (a) to verify whether the seminal plasma OPN is associated with seminal traits and a standard breeding soundness exam; (b) to predict OPN interactions with integrins, CD44 and glycosaminoglycans through molecular docking; and (c) to develop a protocol for recombinant expression of OPN from vesicular gland cDNA. Ejaculates from top ranked bulls had higher amounts of seminal plasma OPN in comparison with bulls classified as questionable (p < .01). The structural modelling and molecular docking predictions indicated that bovine OPN binds to heparin disaccharide, hyaluronic acid and hyaluronan. In addition, docking studies described the binding complexes of OPN with CD44 and the integrin heterodimers α5ß1 and αVß3. Finally, expression of rOPN-6His was successfully obtained after 3 hr of induction with 0.5 mM IPTG at 37°C and a denaturing purification protocol resulted in efficiently purified recombinant OPN. The present results contribute to the development of biotechnological uses of OPN as a biomarker in bovine reproduction.
Assuntos
Osteopontina , Análise do Sêmen/veterinária , Sêmen , Animais , Bovinos , Fertilidade , Masculino , Simulação de Acoplamento Molecular , Osteopontina/genéticaRESUMO
Background: Platelet rich plasma (PRP) is a blood-derived source of growth factors and several cytokines, which are essential for tissue regeneration and important for wound healing due to their angiogenic, mitogenic, and chemotactic activities. To date no protocol has been established for PRP production. Standardization of this technique should consider fundamental factors such as experimental model used, blood collection method, anticoagulant choice, rotation and amount of centrifugations, elapsed time between sample activation and its clinical use in order to ensure quality and biological effects of the product. This study aimed to compare three protocols for PRP achievement in order to evaluate platelet enrichment ability and method reproducibility for further use in clinical investigations regarding PRP therapeutic properties. Materials, Methods & Results: New Zealand higid rabbits whole blood was collected in tubes containing sodium citrate. Samples were obtained through exsanguination, via abdominal aortic puncture, and separated in four aliquots designed for PRP processing and basal platelet count. The count was conducted at the time blood was collected and after every concentration protocol. Methods were tested in triplicates, and three different individuals repeated each technique for three times, reaching 27 repetitions. Selected methodologies consisted in two c
O plasma rico em plaquetas derivado de sangue autólogo é definido como um volume de plasma com uma concentração plaquetária acima dos níveis fisiológicos. É uma fonte autógena e de baixo custo de fatores de crescimento (FC). FC são moléculas bioativas fundamentais no reparo e regeneração de diversos tecidos, capazes de estimular a mitogênese, angiogênese, quimiotaxia, proliferação e diferenciação celular. Entre os fatores liberados pelas plaquetas destacam-se: Fator de Crescimento Derivado de Plaquetas (PDGF), Fator de Crescimento Transformador Beta (TGF- ), Fator de Crescimento Endotelial Vascular (VEGF) e Fator de Crescimento Epitelial (EGF). [...]
RESUMO
Background: Biological membranes demonstrate superiority over synthetic ones for its biocompatibility and strength in the reduction of abdominal hernias. Recents tissue engineering researches add mesenchymal stem cells to biological membranes with the purpose of obtaining additional cellular proliferation and consequent muscle regeneration, using biological membranes as cellular scaffolds. This article aimed to study the influence of mesenchymal stem cells in muscle regeneration in abdominal hernias, reduced with biological membranes. Materials, Methods & Results: Adult Wistar rats underwent abdominal hernia-inducing. They were divided into two groups as to the form of treatment for the reduction of hernia: stem cells associated with biological membranes or only biological membranes. After the treatment the macro and microscopic reviews were carried out in days seven, 14 and 60 postoperatively. Preparation of bovine pericardium with glycerin 98% presented efficiency in decellularization and conservation, maintaining its strength and avoiding bacterial growth. The mesenchymal stem cells obtained from bone marrow of adult Wistar rats, had capacity of proliferation. The majority of the cells was positive for the expression of surface antigens CD44, CD29 and CD99 and was negative for CD 34. In the differentiation trials, the same cells were able to differentiate into adipocytes
Vários tipos de implantes, naturais ou sintéticos, vêm sendo testados no reparo cirúrgico de hérnias. As membranas biológicas, ou arcabouços dérmicos descelularizados, apresentam reduzida formação de aderência entre o implante e as vísceras, diminuição da formação de fístulas, infecções e recorrências. Também apresentam resistência suficiente para suportar a pressão abdominal, evitando deiscências e eviscerações. [...]
RESUMO
As cirurgias endoscópicas transluminais por orifícios naturais ou NOTES (Natural Orifice Transluminal Endoscopic Surgery), significam um novo conceito de cirurgia uma vez que são produzidas pela hibridização de endoscopia e laparoscopia, culminando em uma modalidade cirúrgica com ausência de incisões abdominais. Diversas vias de acesso para a NOTES já foram descritas na literatura dentre elas: a via transvaginal, a transgástrica, a transuretral, a transcolônica e a transretal, sendo os acessos transvaginal e trangástrico os mais estudados até o momento. Apesar da NOTES apresentar vantagens como menor dor abdominal, rápida recuperação pós-operatória, menor risco de aderências e herniações, ausência de cicatriz e menor reposta inflamatória sistêmica, a necessidade de um fechamento seguro da víscera de acesso à cavidade abdominal, bem como adequada cicatrização do órgão ainda são desafios desta nova abordagem cirúrgica. Desta maneira, o presente trabalho tem por objetivo trazer uma revisão bibliográfica da cirurgia por orifícios naturais, como também suas implicações clínicas decorrentes dos diferentes acessos à cavidade abdominal.
RESUMO
As cirurgias endoscópicas transluminais por orifícios naturais ou NOTES (Natural Orifice Transluminal Endoscopic Surgery), significam um novo conceito de cirurgia uma vez que são produzidas pela hibridização de endoscopia e laparoscopia, culminando em uma modalidade cirúrgica com ausência de incisões abdominais. Diversas vias de acesso para a NOTES já foram descritas na literatura dentre elas: a via transvaginal, a transgástrica, a transuretral, a transcolônica e a transretal, sendo os acessos transvaginal e trangástrico os mais estudados até o momento. Apesar da NOTES apresentar vantagens como menor dor abdominal, rápida recuperação pós-operatória, menor risco de aderências e herniações, ausência de cicatriz e menor reposta inflamatória sistêmica, a necessidade de um fechamento seguro da víscera de acesso à cavidade abdominal, bem como adequada cicatrização do órgão ainda são desafios desta nova abordagem cirúrgica. Desta maneira, o presente trabalho tem por objetivo trazer uma revisão bibliográfica da cirurgia por orifícios naturais, como também suas implicações clínicas decorrentes dos diferentes acessos à cavidade abdominal.
RESUMO
Background: Biological membranes demonstrate superiority over synthetic ones for its biocompatibility and strength in the reduction of abdominal hernias. Recents tissue engineering researches add mesenchymal stem cells to biological membranes with the purpose of obtaining additional cellular proliferation and consequent muscle regeneration, using biological membranes as cellular scaffolds. This article aimed to study the influence of mesenchymal stem cells in muscle regeneration in abdominal hernias, reduced with biological membranes. Materials, Methods & Results: Adult Wistar rats underwent abdominal hernia-inducing. They were divided into two groups as to the form of treatment for the reduction of hernia: stem cells associated with biological membranes or only biological membranes. After the treatment the macro and microscopic reviews were carried out in days seven, 14 and 60 postoperatively. Preparation of bovine pericardium with glycerin 98% presented efficiency in decellularization and conservation, maintaining its strength and avoiding bacterial growth. The mesenchymal stem cells obtained from bone marrow of adult Wistar rats, had capacity of proliferation. The majority of the cells was positive for the expression of surface antigens CD44, CD29 and CD99 and was negative for CD 34. In the differentiation trials, the same cells were able to differentiate into adipocytes
Vários tipos de implantes, naturais ou sintéticos, vêm sendo testados no reparo cirúrgico de hérnias. As membranas biológicas, ou arcabouços dérmicos descelularizados, apresentam reduzida formação de aderência entre o implante e as vísceras, diminuição da formação de fístulas, infecções e recorrências. Também apresentam resistência suficiente para suportar a pressão abdominal, evitando deiscências e eviscerações. [...]
RESUMO
Background: Platelet rich plasma (PRP) is a blood-derived source of growth factors and several cytokines, which are essential for tissue regeneration and important for wound healing due to their angiogenic, mitogenic, and chemotactic activities. To date no protocol has been established for PRP production. Standardization of this technique should consider fundamental factors such as experimental model used, blood collection method, anticoagulant choice, rotation and amount of centrifugations, elapsed time between sample activation and its clinical use in order to ensure quality and biological effects of the product. This study aimed to compare three protocols for PRP achievement in order to evaluate platelet enrichment ability and method reproducibility for further use in clinical investigations regarding PRP therapeutic properties. Materials, Methods & Results: New Zealand higid rabbits whole blood was collected in tubes containing sodium citrate. Samples were obtained through exsanguination, via abdominal aortic puncture, and separated in four aliquots designed for PRP processing and basal platelet count. The count was conducted at the time blood was collected and after every concentration protocol. Methods were tested in triplicates, and three different individuals repeated each technique for three times, reaching 27 repetitions. Selected methodologies consisted in two c
O plasma rico em plaquetas derivado de sangue autólogo é definido como um volume de plasma com uma concentração plaquetária acima dos níveis fisiológicos. É uma fonte autógena e de baixo custo de fatores de crescimento (FC). FC são moléculas bioativas fundamentais no reparo e regeneração de diversos tecidos, capazes de estimular a mitogênese, angiogênese, quimiotaxia, proliferação e diferenciação celular. Entre os fatores liberados pelas plaquetas destacam-se: Fator de Crescimento Derivado de Plaquetas (PDGF), Fator de Crescimento Transformador Beta (TGF- ), Fator de Crescimento Endotelial Vascular (VEGF) e Fator de Crescimento Epitelial (EGF). [...]
RESUMO
This paper aims to present a new experimental model of mandibular defect reconstruction in rabbits. It was used 14 animals, in which, in a first stage the left permanent inferior incisive tooth was extracted surgically. After a 50 days period for the bone to fulfill the dentary alveolus, surgery was performed. At first, a 10x5x5mm autograft was removed form the iliac crest, following a partial mandibular failure in the bone with the same auto graft size which was filled with the graft and fixed using titanium microplate. The rabbits were submitted to clinical and radiographic evaluation and 7 of them were euthanasiated at 15 days and the other 7 at 30 days to macro and microscopic analysis. The water and commercial food ingestion was not compromised, and the animals did not showed any chewing or apprehension difficulties, neither pain. Only one animal presented rejection to one screw, without occurring micro plate nor auto graft dislocation. This method showed to be efficient for an experimental model of reconstruction in mandibular defects of rabbits, demonstrating a healing evolution of the graft through radiographic, macroscopic and microscopic exams in 15th and 30th days.
Este trabalho tem como objetivo apresentar um novo modelo experimental de reconstrução em falha mandibular em coelhos. Foram utilizados 14 animais, nos quais, em uma primeira etapa, extraiu-se cirurgicamente o dente incisivo inferior esquerdo permanente. Após um período de 50 dias para o preenchimento ósseo do alvéolo dentário, foi realizada a cirurgia. Inicialmente, coletou-se 10x5x5mm de enxerto ósseo autógeno da crista ilíaca e, em seguida, foi procedida uma falha mandibular parcial de mesmo tamanho, que foi preenchida com o enxerto e fixada com microplaca de titânio. Os coelhos foram submetidos a avaliações clínicas e radiográficas, sendo sete submetidos a eutanásia aos 15 dias e os demais aos 30 dias para análise macro e microscópica. A ingestão de água e ração não foi comprometida, e os animais não apresentaram algia, dificuldade de mastigação e de apreensão. Somente um animal apresentou rejeição a um parafuso, sem ocorrer o deslocamento da placa nem do enxerto. Esse método mostrou-se eficaz como modelo experimental de reconstrução em falha mandibular de coelhos, demonstrando a evolução cicatricial óssea do enxerto por meio dos exames radiográficos, macroscópicos e microscópicos aos 15 e 30 dias.
RESUMO
This paper aims to present a new experimental model of mandibular defect reconstruction in rabbits. It was used 14 animals, in which, in a first stage the left permanent inferior incisive tooth was extracted surgically. After a 50 days period for the bone to fulfill the dentary alveolus, surgery was performed. At first, a 10x5x5mm autograft was removed form the iliac crest, following a partial mandibular failure in the bone with the same auto graft size which was filled with the graft and fixed using titanium microplate. The rabbits were submitted to clinical and radiographic evaluation and 7 of them were euthanasiated at 15 days and the other 7 at 30 days to macro and microscopic analysis. The water and commercial food ingestion was not compromised, and the animals did not showed any chewing or apprehension difficulties, neither pain. Only one animal presented rejection to one screw, without occurring micro plate nor auto graft dislocation. This method showed to be efficient for an experimental model of reconstruction in mandibular defects of rabbits, demonstrating a healing evolution of the graft through radiographic, macroscopic and microscopic exams in 15th and 30th days.
Este trabalho tem como objetivo apresentar um novo modelo experimental de reconstrução em falha mandibular em coelhos. Foram utilizados 14 animais, nos quais, em uma primeira etapa, extraiu-se cirurgicamente o dente incisivo inferior esquerdo permanente. Após um período de 50 dias para o preenchimento ósseo do alvéolo dentário, foi realizada a cirurgia. Inicialmente, coletou-se 10x5x5mm de enxerto ósseo autógeno da crista ilíaca e, em seguida, foi procedida uma falha mandibular parcial de mesmo tamanho, que foi preenchida com o enxerto e fixada com microplaca de titânio. Os coelhos foram submetidos a avaliações clínicas e radiográficas, sendo sete submetidos a eutanásia aos 15 dias e os demais aos 30 dias para análise macro e microscópica. A ingestão de água e ração não foi comprometida, e os animais não apresentaram algia, dificuldade de mastigação e de apreensão. Somente um animal apresentou rejeição a um parafuso, sem ocorrer o deslocamento da placa nem do enxerto. Esse método mostrou-se eficaz como modelo experimental de reconstrução em falha mandibular de coelhos, demonstrando a evolução cicatricial óssea do enxerto por meio dos exames radiográficos, macroscópicos e microscópicos aos 15 e 30 dias.
RESUMO
This paper aims to present a new experimental model of mandibular defect reconstruction in rabbits. It was used 14 animals, in which, in a first stage the left permanent inferior incisive tooth was extracted surgically. After a 50 days period for the bone to fulfill the dentary alveolus, surgery was performed. At first, a 10x5x5mm autograft was removed form the iliac crest, following a partial mandibular failure in the bone with the same auto graft size which was filled with the graft and fixed using titanium microplate. The rabbits were submitted to clinical and radiographic evaluation and 7 of them were euthanasiated at 15 days and the other 7 at 30 days to macro and microscopic analysis. The water and commercial food ingestion was not compromised, and the animals did not showed any chewing or apprehension difficulties, neither pain. Only one animal presented rejection to one screw, without occurring micro plate nor auto graft dislocation. This method showed to be efficient for an experimental model of reconstruction in mandibular defects of rabbits, demonstrating a healing evolution of the graft through radiographic, macroscopic and microscopic exams in 15th and 30th days.
Este trabalho tem como objetivo apresentar um novo modelo experimental de reconstrução em falha mandibular em coelhos. Foram utilizados 14 animais, nos quais, em uma primeira etapa, extraiu-se cirurgicamente o dente incisivo inferior esquerdo permanente. Após um período de 50 dias para o preenchimento ósseo do alvéolo dentário, foi realizada a cirurgia. Inicialmente, coletou-se 10x5x5mm de enxerto ósseo autógeno da crista ilíaca e, em seguida, foi procedida uma falha mandibular parcial de mesmo tamanho, que foi preenchida com o enxerto e fixada com microplaca de titânio. Os coelhos foram submetidos a avaliações clínicas e radiográficas, sendo sete submetidos a eutanásia aos 15 dias e os demais aos 30 dias para análise macro e microscópica. A ingestão de água e ração não foi comprometida, e os animais não apresentaram algia, dificuldade de mastigação e de apreensão. Somente um animal apresentou rejeição a um parafuso, sem ocorrer o deslocamento da placa nem do enxerto. Esse método mostrou-se eficaz como modelo experimental de reconstrução em falha mandibular de coelhos, demonstrando a evolução cicatricial óssea do enxerto por meio dos exames radiográficos, macroscópicos e microscópicos aos 15 e 30 dias.
RESUMO
During semen cryopreservation, sperm cells were submitted to several deleterious events leading to membrane damage which result in fertility decrease. This study was designed to compare the effects of two freezing techniques (conventional and automated), and the use of two commercial extenders as cryoprotectants (FR-5® and Botu-Crio®) on total and progressive motility, integrity and functionality of spermatic membranes during the cryopreservation of equine semen. Twenty ejaculates from two stallions were analyzed. The total and progressive motility of fresh and post-thawing semen samples were evaluated by patterns assays. Function of plasmatic membrane was measured by the hipoosmotic swelling test. Integrity of plasmatic membrane was evaluated using carboxifluorescein diacatate and iodidium propide fluorescent probes. There were significant differences between the two freezing techniques and/or between cryoprotectants for all assessed parameters. The combination of Botu-Crio® and automated curves showed better results on total and progressive post-thawing motility. The extender Botu-Crio®, alone, showed to better preserve the membrane integrity and function.
Durante o processo de criopreservação de sêmen, os espermatozóides sofrem alguns danos que resultam na diminuição da fertilidade deste. O presente estudo foi realizado com o objetivo de avaliar os efeitos da utilização combinada de duas curvas de congelamento com dois diluentes comerciais (FR-5® e Botu-Crio®) sobre a criopreservação de sêmen eqüino. Foram analisados 20 ejaculados de dois garanhões. As amostras foram avaliadas por microscopia de contraste de fase e microscopia de epifluorescência, observando-se a motilidade progressiva e total do sêmen pós-descongelamento e a integridade e a funcionalidade da membrana dos espermatozóides. A combinação entre curva automatizada e Botu-Crio® apresentou as maiores médias nas análises de motilidade total e progressiva, após o descongelamento. O diluente Botu-Crio®, isoladamente, preservou também as membranas destes, quando foram realizadas as análises de integridade utilizando teste com diacetato de carboxifluoresceína e iodeto de propídio e funcionalidade de membrana pelo teste hiposmótico.
RESUMO
This study presents an experimental model of an acute deffect in a peripheral nerve to evaluate neural regeneration using a tubulization technique associated with the inoculation of autologous stem cells from bone marrow. A total of 12 New Zealand white rabbits underwent a bilateral dissection of the tibial nerve followed by repair with silicone tubulization. On the left tibial nerve of all animals, the tube was filled with autologous bone marrow-derived stem cells collected from the humerus. For control, using the same repair technique, the tubes were filled with a NaCl solution in the right tibial nerve. After 30 days of observation, the animals were euthanized and a histological evaluation of the collected nerve segments was performed by staining with hematoxylin-eosin, luxol fast blue, and toluidine blue. From the results it is possible to conclude that the transplanted autologous stem cells associated with the tubulization technique present an advantage in the peripheral nerve regeneration process.
Neste estudo é apresentado um modelo experimental de defeito agudo em nervo periférico para avaliação da regeneração nervosa mediante técnica de tubulização associada à inoculação de células-tronco autólogas de medula óssea. Foram utilizados 12 coelhos Nova Zelândia albinos, submetidos à secção bilateral e ao afastamento de 5mm do nervo tibial e posterior reparo mediante utilização de câmara de silicone. Internamente à prótese de tubulização do nervo tibial esquerdo em todos os animais, foram inoculadas células-tronco autólogas de medula óssea, coletadas a partir do úmero. Como grupo controle (nervo tibial direito), mediante aplicação da mesma técnica de reparo, solução de NaCl 0,9% foi administrada internamente à prótese. Após 30 dias de observação, os animais foram eutanasiados e foi realizada a avaliação histológica dos segmentos nervosos por meio das colorações de hematoxilina-eosina, luxol fast blue e azul de toluidina. Com os resultados, foi possível concluir que o transplante de células-tronco autólogas associado à técnica de tubulização apresenta vantagens no processo de regeneração nervosa periférica.
RESUMO
This study presents an experimental model of an acute deffect in a peripheral nerve to evaluate neural regeneration using a tubulization technique associated with the inoculation of autologous stem cells from bone marrow. A total of 12 New Zealand white rabbits underwent a bilateral dissection of the tibial nerve followed by repair with silicone tubulization. On the left tibial nerve of all animals, the tube was filled with autologous bone marrow-derived stem cells collected from the humerus. For control, using the same repair technique, the tubes were filled with a NaCl solution in the right tibial nerve. After 30 days of observation, the animals were euthanized and a histological evaluation of the collected nerve segments was performed by staining with hematoxylin-eosin, luxol fast blue, and toluidine blue. From the results it is possible to conclude that the transplanted autologous stem cells associated with the tubulization technique present an advantage in the peripheral nerve regeneration process.
Neste estudo é apresentado um modelo experimental de defeito agudo em nervo periférico para avaliação da regeneração nervosa mediante técnica de tubulização associada à inoculação de células-tronco autólogas de medula óssea. Foram utilizados 12 coelhos Nova Zelândia albinos, submetidos à secção bilateral e ao afastamento de 5mm do nervo tibial e posterior reparo mediante utilização de câmara de silicone. Internamente à prótese de tubulização do nervo tibial esquerdo em todos os animais, foram inoculadas células-tronco autólogas de medula óssea, coletadas a partir do úmero. Como grupo controle (nervo tibial direito), mediante aplicação da mesma técnica de reparo, solução de NaCl 0,9% foi administrada internamente à prótese. Após 30 dias de observação, os animais foram eutanasiados e foi realizada a avaliação histológica dos segmentos nervosos por meio das colorações de hematoxilina-eosina, luxol fast blue e azul de toluidina. Com os resultados, foi possível concluir que o transplante de células-tronco autólogas associado à técnica de tubulização apresenta vantagens no processo de regeneração nervosa periférica.
RESUMO
During semen cryopreservation, sperm cells were submitted to several deleterious events leading to membrane damage which result in fertility decrease. This study was designed to compare the effects of two freezing techniques (conventional and automated), and the use of two commercial extenders as cryoprotectants (FR-5® and Botu-Crio®) on total and progressive motility, integrity and functionality of spermatic membranes during the cryopreservation of equine semen. Twenty ejaculates from two stallions were analyzed. The total and progressive motility of fresh and post-thawing semen samples were evaluated by patterns assays. Function of plasmatic membrane was measured by the hipoosmotic swelling test. Integrity of plasmatic membrane was evaluated using carboxifluorescein diacatate and iodidium propide fluorescent probes. There were significant differences between the two freezing techniques and/or between cryoprotectants for all assessed parameters. The combination of Botu-Crio® and automated curves showed better results on total and progressive post-thawing motility. The extender Botu-Crio®, alone, showed to better preserve the membrane integrity and function.
Durante o processo de criopreservação de sêmen, os espermatozóides sofrem alguns danos que resultam na diminuição da fertilidade deste. O presente estudo foi realizado com o objetivo de avaliar os efeitos da utilização combinada de duas curvas de congelamento com dois diluentes comerciais (FR-5® e Botu-Crio®) sobre a criopreservação de sêmen eqüino. Foram analisados 20 ejaculados de dois garanhões. As amostras foram avaliadas por microscopia de contraste de fase e microscopia de epifluorescência, observando-se a motilidade progressiva e total do sêmen pós-descongelamento e a integridade e a funcionalidade da membrana dos espermatozóides. A combinação entre curva automatizada e Botu-Crio® apresentou as maiores médias nas análises de motilidade total e progressiva, após o descongelamento. O diluente Botu-Crio®, isoladamente, preservou também as membranas destes, quando foram realizadas as análises de integridade utilizando teste com diacetato de carboxifluoresceína e iodeto de propídio e funcionalidade de membrana pelo teste hiposmótico.
RESUMO
During the last few years, embryonic stem (ES) cells have been a new tool in cell biology which is very promising for the scientific community to develop new cell therapies. ES cells are the only cell type that can differentiate into derivates of the three primary germ layers, not only in vivo but also, and most important, in vitro. This so-called pluripotency has resulted in the field of stem cell technology going into overdrive, and the establishment of many protocols for optimal maintenance, culture, genetic transfection and in vitro differentiation. The first pluripotent cells had been derived from teratocarcinomas, maligne tumors, and showed some disadvantages. Therefore later embryonic stem cells, and now adult stem cells are getting special attention from the scientists. In this study, we established for the first time in our country, the prolonged culture of undifferentiated ES cells in vitro and the pointed induction of cell differentiation into specific cell types. It is the result of an international collaboration program supported by Brazil and Germany, CAPES and DAAD (PROBRAL). The well-established routine should be clearly demonstrated by the continuous culture and propagation of several mouse ES lines in vitro under specific culture conditions preventing differentiation. On the other hand, these ES cells were exposed to defined differentiation induction systems t
RESUMO
During the last few years, embryonic stem (ES) cells have been a new tool in cell biology which is very promising for the scientific community to develop new cell therapies. ES cells are the only cell type that can differentiate into derivates of the three primary germ layers, not only in vivo but also, and most important, in vitro. This so-called pluripotency has resulted in the field of stem cell technology going into overdrive, and the establishment of many protocols for optimal maintenance, culture, genetic transfection and in vitro differentiation. The first pluripotent cells had been derived from teratocarcinomas, maligne tumors, and showed some disadvantages. Therefore later embryonic stem cells, and now adult stem cells are getting special attention from the scientists. In this study, we established for the first time in our country, the prolonged culture of undifferentiated ES cells in vitro and the pointed induction of cell differentiation into specific cell types. It is the result of an international collaboration program supported by Brazil and Germany, CAPES and DAAD (PROBRAL). The well-established routine should be clearly demonstrated by the continuous culture and propagation of several mouse ES lines in vitro under specific culture conditions preventing differentiation. On the other hand, these ES cells were exposed to defined differentiation induction systems t
RESUMO
During the last few years, embryonic stem (ES) cells have been a new tool in cell biology which is very promising for the scientific community to develop new cell therapies. ES cells are the only cell type that can differentiate into derivates of the three primary germ layers, not only in vivo but also, and most important, in vitro. This so-called pluripotency has resulted in the field of stem cell technology going into overdrive, and the establishment of many protocols for optimal maintenance, culture, genetic transfection and in vitro differentiation. The first pluripotent cells had been derived from teratocarcinomas, maligne tumors, and showed some disadvantages. Therefore later embryonic stem cells, and now adult stem cells are getting special attention from the scientists. In this study, we established for the first time in our country, the prolonged culture of undifferentiated ES cells in vitro and the pointed induction of cell differentiation into specific cell types. It is the result of an international collaboration program supported by Brazil and Germany, CAPES and DAAD (PROBRAL). The well-established routine should be clearly demonstrated by the continuous culture and propagation of several mouse ES lines in vitro under specific culture conditions preventing differentiation. On the other hand, these ES cells were exposed to defined differentiation induction systems t