Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
1.
Reprod Fertil Dev ; 29(5): 950-967, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28442046

RESUMO

Cloning procedures often interfere with conceptus growth and life ex utero, in a set of symptoms known as abnormal offspring syndrome (AOS). The aim of the present study was to compare the developmental pattern of in vivo-derived (IVD), IVF-derived and handmade cloning-derived (NT-HMC) Day 225 bovine concepti using established procedures. Pregnancy diagnosis was performed on Day 30 following blastocyst transfer on Day 7. Conceptus morphometry was assessed by ultrasonography on Day 51, and on Day 225 pregnant cows were killed for morphological examination of concepti. Pregnancy outcome was similar between groups, with greater pregnancy losses in the first trimester (70.6%) and smaller fetuses on Day 51 in the NT-HMC group than in the IVD (14.3%) and IVF (20.0%) groups. However, NT-HMC-derived concepti were twofold larger on Day 225 of gestation than controls. A higher frequency (63.5%) of placentomes larger than the largest in the IVD group was observed in the NT-HMC group, which may be relevant to placental function. Conceptus traits in the IVF group were similar to the IVD controls, with only slight changes in placentome types. Morphological changes in cloned concepti likely affected placental function and metabolism, disrupting the placental constraining mechanism on fetal growth in mid- to late pregnancy.


Assuntos
Clonagem de Organismos , Desenvolvimento Embrionário/fisiologia , Animais , Bovinos , Transferência Embrionária/veterinária , Feminino , Fertilização in vitro/veterinária , Técnicas de Transferência Nuclear/veterinária , Gravidez , Resultado da Gravidez , Ultrassonografia Pré-Natal/veterinária
2.
J Appl Microbiol ; 121(2): 364-72, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27038077

RESUMO

AIMS: To identify and characterize the lysis gene cassette from the bacteriophage ST79 that lyses Burkholderia pseudomallei. METHODS AND RESULTS: Approximately 1·5 kb of ST79 lysis genes were identified from the phage genome data. It was composed of holin, peptidase M15A or endolysin, lysB and lysC. Each gene and its combinations were cloned into Escherichia coli and the lytic effects were measured. Co-expression of holin and peptidase M15A showed the highest lysis activity. Expression of holin, lysB/C or holin-peptidase M15A-lysB/lysC lysed the E. coli membrane, whereas peptidase M15A alone did not. The predicted transmembrane structures of holin and lysB/C indicated that they could be inserted into the bacterial membrane to form pores, affecting cell permeability and causing lysis. CONCLUSION: This is the first report of an investigation into the lysis genes of B. pseudomallei's lytic phage using E. coli as a model. SIGNIFICANCE AND IMPACT OF THE STUDY: Burkholderia pseudomallei, a Gram-negative bacterium causing an infectious disease, is intrinsically resistant to several antibiotics, and a vaccine is not available. The lysis genes of ST79, the first reported lytic bacteriophage of B. pseudomallei, were characterized. The development of ST79 as an alternative treatment for skin ulceration, for example, or to be used as a gene cloning tool for B. pseudomallei may be possible with this knowledge.


Assuntos
Bacteriófagos/genética , Burkholderia pseudomallei/virologia , Bacteriófagos/classificação , Burkholderia pseudomallei/genética , Clonagem Molecular , Endopeptidases/genética , Endopeptidases/metabolismo , Escherichia coli/genética , Proteínas Virais/genética
3.
Zygote ; 24(2): 245-51, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25943119

RESUMO

Competent oocyte selection remains a bottleneck in the in vitro production (IVP) of mammalian embryos. Among the vital assays described for selecting competent oocytes for IVP, the brilliant cresyl blue (BCB) test has shown consistent results. The aim of the first experiment was to observe if oocytes directly submitted to IVM show similar cleavage and blastocyst rates as those obtained with oocytes maintained under the same in vitro conditions as the oocytes that undergo the BCB test. Bovine cumulus-oocyte complexes (COCs) were recovered from slaughterhouse-derived ovaries and, after morphological evaluation, were randomised grouped into three groups: (1) directly submitted to IVM; (2) oocytes submitted to the BCB test without the addition of BCB stain (BCB control group); and (3) submitted to the BCB test. The results showed that oocytes directly submitted to IVM reached similar cleavage (48/80 - 60%) and embryonic development rates to the blastocyst stage (10/48 - 21%) as the results obtained with the BCB control group oocytes (45/77 - 58% and 08/45 - 18%, respectively). The aim of the second experiment was to determine the cleavage and blastocyst rates obtained from BCB+ oocytes undergoing IVM in the presence of BCB- oocytes at a ratio of 10:1. COCs were recovered from slaughterhouse-derived ovaries and, after morphological evaluation, were randomised into two groups that were submitted to IVM either directly (1: control group) or submitted to the BCB test prior to IVM. After the BCB test, the COCs were classified as either BCB+ (blue cytoplasm) or BCB- (colourless cytoplasm) and then divided into four experimental groups: (2) BCB+; (3) BCB-; and (4) BCB+ matured in same IVM medium drop as (5) BCB- at a ratio of 10:1. After IVM (24 h), oocytes from the different experimental groups were submitted to in vitro fertilisation (IVF) and in vitro culture (IVC) under the same culture conditions until they reached the blastocyst stage (D7). With regards to the cleavage rate (48 h after IVF), only group 3 (102/229 - 44%) differed (P < 0.05) from the other groups [1 (145/241 - 60%); 2 (150/225 - 67%); 4 (201/318 - 63%) and 5 (21/33 - 63%)]. On day 7, the embryos from group 2 (BCB+) achieved the highest blastocyst rate (46/150 - 31%) (P < 0.05) when compared with the embryo development capacity of the other experimental groups (1: 31/145 - 21%; group 3: 17/102 - 17%; group 4: 46/201 - 23%; and group 5: 2/21 - 10%). In conclusion, submitting BCB+ oocytes that were separated from BCB- oocytes to IVM increases the rate of embryonic development to the blastocyst stage when compared to the control group, BCB- oocyte group, BCB+ paracrine group and BCB- paracrine group. The presence of non-competent oocytes during IVM, even in low proportion (1:10), reduces the capacity of competent oocytes to undergo embryo development and achieve blastocyst stage during IVC.


Assuntos
Blastocisto/fisiologia , Desenvolvimento Embrionário/fisiologia , Fertilização in vitro/métodos , Técnicas de Maturação in Vitro de Oócitos/métodos , Oócitos/fisiologia , Animais , Blastocisto/citologia , Bovinos , Células Cultivadas , Técnicas de Cultura Embrionária/métodos , Técnicas de Cultura Embrionária/veterinária , Feminino , Fertilização in vitro/veterinária , Técnicas de Maturação in Vitro de Oócitos/veterinária , Masculino , Oócitos/citologia , Oxazinas/química
4.
Reprod Domest Anim ; 50(5): 763-70, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26280459

RESUMO

Oocyte selection based on the brilliant cresyl blue (BCB) staining test has been successfully used to differentiate between competent and incompetent bovine oocytes. Here, the expression of genes involved in transport of monocarboxylates (Mct1-4) and oogenesis specific genes (Bmp15, Gdf9 and Has2) in BCB+ and BCB- selected immature and mature bovine cumulus-oocyte complexes (COC) was evaluated. In order to find specific molecular markers to characterize successful oocyte maturation, our study was also aimed at identifying the expression of Mcts and oogenesis specific genes in denuded oocytes and cumulus cells. Immature COCs morphological appropriate were (i) stained with 26 mm BCB for 90 min before IVM, (ii) exposed to same incubation conditions as stained COCs, but without BCB (holding group) or (iii) transferred into a maturation medium immediately after morphological selection (control group). mRNA expression was investigated by RT-PCR in COCs before and after IVM. No relationship was observed in the relative expression of Has2, Gdf9, Bmp15 or Mct1, 2 and 4 transcripts between BCB+ and BCB- COCs. Transcripts analysis showed that Gdf9 and Bmp15 in BCB+, BCB- and holding groups were up-regulated (p < 0.05) before IVM, while Has2 was up-regulated (p < 0.01) after IVM in the control group. Other genes remained stable during maturation (Mct1, 2 and 4). Our results showed, for the first time, Mct1, 2 and 4 expression in bovine COCs. Mct1 and Mct4 transcripts were present in denuded oocytes and cumulus cell, while Mct2 was detected only in cumulus cells. These differences between the three isoforms in localization suggest unique roles for each in monocarboxylate transport during maturation.


Assuntos
Bovinos , Células do Cúmulo/metabolismo , Expressão Gênica , Transportadores de Ácidos Monocarboxílicos/genética , Oócitos/metabolismo , Oogênese/genética , Animais , Proteína Morfogenética Óssea 15/genética , Corantes , Células do Cúmulo/química , Feminino , Glucuronosiltransferase/genética , Fator 9 de Diferenciação de Crescimento/genética , Hialuronan Sintases , Técnicas de Maturação in Vitro de Oócitos , Oócitos/química , Oxazinas , RNA Mensageiro/análise
5.
Reprod Domest Anim ; 49(4): 648-656, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24943879

RESUMO

The presence of the zona pellucida has been perceived as a requirement for the oviductal transfer of cloned embryos at early stages of development while protecting the embryo from an immune system response. We hypothesized that steroid hormone therapy could reduce a potential cellular immune response after the transfer of zona-free cloned embryos into the oviduct of recipient female goats. In Experiment 1, seven does were used to study the systemic immunosuppressant effect of the methylprednisolone administration (for 3 days) on blood cell counts. Whole blood was collected prior to treatment with methyprednisolone and then on Days 1, 2, 3, 4, 7, 14, 21 and 28 after the first dose of methylprednisolone for the analysis of haematological parameters. Methylprednisolone treatment significantly reduced circulating white blood cells and neutrophils in comparison with pre-treatment levels, demonstrating a systemic immunosuppressant effect. In Experiment 2, a group of 58 does were used as recipient females to study the effect of administration of methylprednisolone for 3 days on the establishment of pregnancies after the transfer of zona-free cloned embryos into the oviducts. No effects on pregnancy rates on Day 30 were observed regarding the distinct treatment groups (control vs. methylprednisolone), the source of oocytes (in vivo- vs in vitro-matured) or the presence or absence of the zona pellucida in embryos. In summary, methylprednisolone was effective at inducing a systemic immunosuppressed state in goats, but the treatment prior to embryo transfer did not affect pregnancy rates. Moreover, pregnancy rates were similar between zona-free and zona-intact goat cloned embryos.


Assuntos
Clonagem de Organismos/veterinária , Transferência Embrionária/veterinária , Cabras , Terapia de Imunossupressão/veterinária , Metilprednisolona/administração & dosagem , Animais , Transferência Embrionária/métodos , Feminino , Terapia de Imunossupressão/métodos , Contagem de Leucócitos/veterinária , Neutrófilos , Técnicas de Transferência Nuclear/veterinária , Gravidez , Taxa de Gravidez , Zona Pelúcida/imunologia
6.
Eur J Prosthodont Restor Dent ; 22(3): 132-5, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25831715

RESUMO

This study evaluated the effects of the remaining coronal tissue and post type on the fracture strength of incisors. Sixty human maxillary central incisors were sectioned at the cemento-enamel junction or at 2 mm above this junction. The roots received cast cores and posts, fibre posts, or relined fibre posts (n = 10 each). A compressive load was applied over the cores untilfracture. In the absence of coronal structure, the fracture strength did not differ among the post types evaluated. In the presence of remaining coronal structure, the fracture strength was higher in specimens with cast cores and posts.


Assuntos
Planejamento de Prótese Dentária , Falha de Restauração Dentária , Incisivo/patologia , Técnica para Retentor Intrarradicular/instrumentação , Coroa do Dente/patologia , Resinas Compostas/química , Força Compressiva , Ligas Dentárias/química , Materiais Dentários/química , Análise do Estresse Dentário/instrumentação , Adesivos Dentinários/química , Resinas Epóxi/química , Vidro/química , Humanos , Cimentos de Resina/química , Preparo de Canal Radicular/métodos , Estresse Mecânico , Propriedades de Superfície
7.
Braz J Biol ; 84: e279474, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38747862

RESUMO

Variability in snake venom composition is well-documented and crucial for understanding snake ecology and predicting snakebites. In this study, we characterize the venom composition and biological activities of newborn female and male Bothrops moojeni and their mother. Our results reveal significant differences between the venom of newborn females and males, demonstrating a broad and diverse range of proteins. The venoms of newborn females showed higher serine protease effects, increased hemorrhagic activity, and greater lethality compared to the venom of newborn males. However, no differences were observed in phospholipase A2 and coagulant activity. The differences in protein composition and toxic activities between maternal and neonatal venom, as well as between the venoms of newborn females and males, contribute to understanding the diverse outcomes of snakebites. These results underscore the importance of considering sex and ontogeny in understanding venom composition in snakes.


Assuntos
Animais Recém-Nascidos , Bothrops , Venenos de Crotalídeos , Animais , Bothrops/classificação , Bothrops/fisiologia , Feminino , Masculino , Fatores Sexuais
8.
Zygote ; 21(3): 250-5, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21791164

RESUMO

The selection of competent oocytes for in vitro maturation is still a major problem during bovine in vitro embryo production. Markers for in vitro cytoplasmic maturation, based on the organization of cortical granule and mitochondria, are lacking. We examined the pre-selection of immature bovine oocytes by brilliant cresyl blue stain (BCB test) based on glucose-6-phosphate dehydrogenase (G6PDH) activity during oocyte development. Oocytes were recovered from ovarian follicles exposed to 26 µM BCB stain and classified according to the aspect of their cytoplasm: BCB(+) (oocytes with blue cytoplasm) and BCB(-) (unstained cytoplasm) and then in vitro matured into a conventional in vitro maturation (IVM) medium and standard procedure. In Experiment 1, nuclear maturation was determined by polar body identification, while cytoplasmic maturation was based on cortical granule (CG) migration (peripheral) and mitochondria distribution (central). Evidence of polar body, cortical granule migration and of centrally located mitochondria was significantly (p < 0.05) higher in BCB(+) oocytes than in BCB(-) (polar body present: 65% vs 20%; peripheral CG: 72% vs. 14%; and central mitochondria: 85% vs. 19%, respectively). In Experiment 2, the efficiency pre-selection of bovine oocytes by BCB on embryo development in vitro was assessed. Cleavage rates were similar (75%) among control, BCB(+) and BCB(-) groups, while blastocyst rates on D7 were (p < 0.05) higher (35%) in BCB(+) vs BCB(-) (10%) or control (28%). We showed that the BCB test is efficient to identify competent immature bovine oocytes to undergo synchronous nuclear and cytoplasmic in vitro maturation thus yielding higher in vitro embryo development to blastocyst stage.


Assuntos
Blastocisto/fisiologia , Oócitos/citologia , Oócitos/fisiologia , Animais , Bovinos , Células Cultivadas , Citoplasma/fisiologia , Desenvolvimento Embrionário , Feminino , Fertilização in vitro , Glucosefosfato Desidrogenase/metabolismo , Técnicas de Maturação in Vitro de Oócitos , Meiose , Mitocôndrias/fisiologia , Folículo Ovariano/citologia , Oxazinas/análise , Coloração e Rotulagem/métodos
9.
J Dairy Sci ; 95(12): 7066-73, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23040024

RESUMO

The reproductive performance of cattle may be influenced by several factors, but mineral imbalances are crucial in terms of direct effects on reproduction. Several studies have shown that elements such as calcium, copper, iron, magnesium, selenium, and zinc are essential for reproduction and can prevent oxidative stress. However, toxic elements such as lead, nickel, and arsenic can have adverse effects on reproduction. In this paper, we applied a simple and fast method of multi-element analysis to bovine semen samples from Zebu and European classes used in reproduction programs and artificial insemination. Samples were analyzed by inductively coupled plasma spectrometry (ICP-MS) using aqueous medium calibration and the samples were diluted in a proportion of 1:50 in a solution containing 0.01% (vol/vol) Triton X-100 and 0.5% (vol/vol) nitric acid. Rhodium, iridium, and yttrium were used as the internal standards for ICP-MS analysis. To develop a reliable method of tracing the class of bovine semen, we used data mining techniques that make it possible to classify unknown samples after checking the differentiation of known-class samples. Based on the determination of 15 elements in 41 samples of bovine semen, 3 machine-learning tools for classification were applied to determine cattle class. Our results demonstrate the potential of support vector machine (SVM), multilayer perceptron (MLP), and random forest (RF) chemometric tools to identify cattle class. Moreover, the selection tools made it possible to reduce the number of chemical elements needed from 15 to just 8.


Assuntos
Espectrometria de Massas/veterinária , Sêmen/química , Oligoelementos/análise , Algoritmos , Animais , Cruzamento/métodos , Bovinos , Indústria de Laticínios/métodos , Mineração de Dados/métodos , Inseminação Artificial/métodos , Inseminação Artificial/veterinária , Masculino , Espectrometria de Massas/métodos , Característica Quantitativa Herdável
10.
Oper Dent ; 36(1): 66-71, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21488731

RESUMO

OBJECTIVES: This study evaluated the effects of the exposure time of eugenol-based provisional restorative material and the time elapsed between the provisional material removal and the adhesive procedure on the bond strength of the composite to dentin. MATERIALS AND METHODS: Human third molars were sectioned into two halves that were enclosed in resin cylinders. The cavities were prepared over the buccal/lingual faces with diamond burs. Zinc oxide and eugenol (ZOE) provisional material was inserted into cavities and left for 24 hours, 7 days or 14 days. The cavities not restored with ZOE were used as controls. After ZOE removal or over fresh dentin (control), self-etching Adper SE Plus was applied immediately, after a 7- or 14-day delay. The cavity was restored with non-eugenol provisional material during this delay period. Cylinders of resin cement were built-up over the hybridized dentin. A shear load was applied to the cylinders at a crosshead speed of 0.5 mm/minute until failure. The data were statistically analyzed using two-way ANOVA and Tukey's tests (α=0.05). RESULTS: Using IRM as a provisional restoration for 24 hours followed by its removal and immediate adhesive application resulted in the lowest values of shear bond strength. There was no significant difference between the other experimental conditions. CONCLUSIONS: The use of IRM for 24 hours adversely affected the shear bond strength of a self-etching adhesive to dentin. The recovery of the proper bond strength occurred one week after IRM removal.


Assuntos
Colagem Dentária , Restauração Dentária Temporária/métodos , Cimentos de Resina , Cimento de Óxido de Zinco e Eugenol , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato , Descolagem Dentária , Análise do Estresse Dentário , Dentina , Adesivos Dentinários , Humanos , Metilmetacrilatos , Organofosfatos , Resistência ao Cisalhamento , Estatísticas não Paramétricas , Fatores de Tempo
11.
Braz J Biol ; 82: e241863, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34133562

RESUMO

Since the classic studies of Alexander Flemming, Penicillium strains have been known as a rich source of antimicrobial substances. Recent studies have identified novel metabolites produced by Penicillium sclerotiorum that have antibacterial, antifouling and pharmaceutical activities. Here, we report the isolation of a P. sclerotiorum (LM 5679) from Amazonian soil and carry out a culture-based study to determine whether it can produce any novel secondary metabolite(s) that are not thus-far reported for this genus. Using a submerged culture system, secondary metabolites were recovered by solvent extract followed by thin-layer chromatography, nuclear magnetic resonance, and mass spectroscopy. One novel secondary metabolite was isolated from P. sclerotiorum (LM 5679); the phenolic compound 5-pentadecyl resorcinol widely known as an antifungal, that is produced by diverse plant species. This metabolite was not reported previously in any Penicillium species and was only found once before in fungi (that time, in a Fusarium). Here, we discuss the known activities of 5-pentadecyl resorcinol in the context of its mode-of-action as a hydrophobic (chaotropicity-mediated) stressor.


Assuntos
Penicillium , Antibacterianos , Antifúngicos , Resorcinóis
13.
Reprod Domest Anim ; 45(6): 1042-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19570146

RESUMO

The objective of this study was to determine the influence of powdered coconut water (ACP-318(®)) diluted in high glucose (11.0 mM) TCM199 in the achievement of nuclear in vitro maturation (IVM) of canine oocytes. Cumulus oocyte complexes (COCs) (n = 632) were randomly allocated into three experimental groups named as group 1 (control group), group 2 (5% powdered coconut water) and group 3 (10% powdered coconut water). The percentage of meiotic resumption (MR) (GVBD to MII) was 39.1% (81/207), 50.2% (108/215) and 46.6% (98/210) for groups 1, 2 and 3 respectively (p < 0.05). There were no differences in MR rates among groups 2 and 3. The medium with ACP-318(®) slightly enhanced the nuclear maturation of canine oocytes when a comparison was established with rates of maturation exhibited by oocytes in the experimental group 1 without ACP-318(®) (p < 0.05). The results suggest that oocytes' nuclear morphology integrity and meiosis achievement were positively influenced when exposed to high glucose TCM199 supplemented with 5% powdered coconut water. Further investigation must be performed for a better understanding of powdered coconut water influence in cellular events during IVM of dog oocytes.


Assuntos
Cocos/química , Meios de Cultura/química , Cães , Oócitos/citologia , Oócitos/fisiologia , Água/química , Animais , Técnicas de Cultura de Células , Feminino , Meiose
14.
Reprod Domest Anim ; 45(1): 99-102, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18992115

RESUMO

Cryopreservation of ovarian tissue is known to affect follicular survival. Several variables may be responsible for this. Little attention has focused on the effect of the size of the fragment to be cryopreserved. This study was conducted to assess the effect of the size of the tissue on follicular histology after freezing with 1,2-propanediol. Histological evaluations were performed of control and cryopreserved tissue. Fragments were cut 10 x 3 x 2 mm(3) (2 mm group) or 10 x 3 x 4 mm(3) (4 mm group). Percentages of normal follicles in control fragments cut into 2 and 4 mm slices were 56% and 34%, respectively. The relative risks to obtain normal follicles in the 2 mm and the 4 mm fragments after cryopreservation were 0.63 and 0.47, respectively. Freezing reduced follicle survival to a significantly greater extent in the larger tissue fragments. There is an increased risk of damage to primary and primordial follicles, when the tissue slices are cut with all dimensions larger than 2 mm.


Assuntos
Bovinos , Criopreservação/veterinária , Ovário/fisiologia , Animais , Criopreservação/métodos , Feminino , Folículo Ovariano/anatomia & histologia , Folículo Ovariano/fisiologia , Ovário/anatomia & histologia , Sobrevivência de Tecidos/fisiologia , Coleta de Tecidos e Órgãos/métodos , Coleta de Tecidos e Órgãos/veterinária
15.
Genet Mol Res ; 9(1): 295-302, 2010 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-20198585

RESUMO

The relationship between the level of cell confluence near the plateau phase of growth and blastocyst yield following somatic cell cloning is not well understood. We examined the effect of distinct cell culture confluence levels on in vitro development of cloned bovine embryos. In vitro-matured bovine oocytes were manually bisected and selected by DNA staining. One or two enucleated hemi-cytoplasts were paired and fused with an adult skin somatic cell. Cultured skin cells from an adult Nellore cow harvested at three distinct culture confluence levels (70-80, 80-90, and >95%) were used for construction of embryos and hemi-embryos. After activation, structures were cultured in vitro as one embryo (1 x 100%) or as aggregates of two hemi-embryos (2 x 50%) per microwell. Fusion, cleavage and blastocyst rates were compared using the chi(2) test. The fusion rate for hemi-embryos (51.4%) was lower than for embryos (67.6%), with no influence of degree of cell confluence. However, blastocyst rates improved linearly (7.0, 17.5, and 29.4%) with increases in cell confluence. We conclude that degree of cell culture confluence significantly influences subsequent embryo development; use of a cell population in high confluence (>90%) for nuclear transfer significantly improved blastocyst yield after cloning.


Assuntos
Técnicas de Cultura de Células/métodos , Clonagem de Organismos/métodos , Embrião de Mamíferos/embriologia , Criação de Embriões para Pesquisa/métodos , Pele/citologia , Animais , Bovinos , Agregação Celular , Células Cultivadas , Embrião de Mamíferos/citologia
16.
Reprod Domest Anim ; 44 Suppl 2: 255-8, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19754581

RESUMO

This study was conducted: (i) to observe the features and levels of blue colour impregnation in morphologically selected immature canine cumulus oocyte complexes (COCs) stained with the brilliant cresyl blue (BCB) dye, as indicators of quality, and integrity of nuclear oocyte chromatin configuration before in vitro maturation (IVM); (ii) to observe the relationship between the influence of serum progesterone (SP) concentrations from ovary donors and BCB staining of immature dog oocytes. The results showed that out of 138 canine COCs, germinal vesicle (GV) stage prevailed in BCB+ oocytes at percentages of 67.4% (60/89), which were statistically higher than those observed in BCB+/- (52.2%; 23/44) and BCB- (20%; 1/5) oocytes (p = 0.023). Oocytes BCB+ were interpreted as those having completed their growth and therefore possessing the capacity to mature and develop in vitro. Ooplasm and cumulus cells (CCs) of canine oocytes were BCB staining independent. Ooplasm blue colour staining reaction varied between grown oocytes, revealing different levels of glucose-6-phosphate dehydrogenase activity among and within oocytes. Additionally, SP profile of ovary donors was not a relevant indicator for selection of oocytes screened with the BCB stain. Similar numbers of high quality oocytes were observed to be BCB+, BCB+/- and BCB- between groups of females with SP varying from 0 to 2.5 ng/ml (n = 5), and those with SP varying from 2.6 to 16.7 ng/ml (n = 4) (p = 0.680). It may be inferred that bitches with low and high SP profiles have grown oocytes in their ovaries, as determined by the BCB absorbance in their ooplasms.


Assuntos
Cães , Oócitos/citologia , Oxazinas/química , Progesterona/sangue , Animais , Células Cultivadas , Corantes/química , Feminino , Oócitos/fisiologia , Coloração e Rotulagem
17.
Reprod Domest Anim ; 44 Suppl 2: 259-62, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19754582

RESUMO

High in vitro oxygen (O(2)) tensions are associated with enhanced levels of reactive oxygen species and cumulus oocyte complex (COC) apoptosis. The objective of this study was to determine the influence of O(2) tension on cumulus cell (CC) viability from canine oocytes. Cumulus oocyte complexes were distributed into three groups (CG, T20 and T5) and two O(2) tension levels (20% and 5%). The control group (CG) was matured in vitro in a humidified atmosphere with 5% CO(2) in air in TCM199 with 26.19 mM sodium bicarbonate, 10% (v/v) foetal calf serum (FCS), 0.10 mM gentamicin, 0.20 mM pyruvic acid, 20 microg/ml oestradiol, 0.5 microg/ml follicle-stimulating hormone, 0.03 IU/ml human chorionic gonadotropin, and 1.0 microg/ml human somatotropin. Groups T20 and T5 were matured under 20% or 5% O(2) tensions respectively in a high-glucose medium, without FCS. T20 and T5 were as CG, and supplemented with 0.1% Polyvinyl Alcohol, and 5.5 mM glucose. After 48 h of IVM, CCs from COCs were stained with propidium iodide (1.50 mM). The results showed that viability of CCs (cytoplasmic features and nuclear morphological integrity) was different for the three groups. Rates of apoptosis were at 57.9% (521/900) for CG, 54.4% (490/900) for T20 and 38.9% (350/900) for T5 (p < 0.001). Predominant features in apoptotic cells (n = 1361) were DNA nuclear fragments (94.0%). It was concluded that CCs of canine COCs cultured in high-glucose medium showed significantly less apoptosis than those cultured in medium with FCS. Low O(2) tension was efficient in reducing apoptosis in canine CCs.


Assuntos
Células do Cúmulo/citologia , Células do Cúmulo/efeitos dos fármacos , Cães , Oócitos/citologia , Oócitos/efeitos dos fármacos , Ovário/citologia , Oxigênio/farmacologia , Animais , Sobrevivência Celular , Meios de Cultura/química , Células do Cúmulo/fisiologia , Feminino , Glucose/química , Oócitos/fisiologia
18.
Reprod Domest Anim ; 43(3): 314-318, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18086255

RESUMO

Vitrification has been the method of choice for the cryopreservation of bovine oocytes, as rapid cooling decreases chilling sensitivity. The aim of this study was to determine the in vitro and in vivo survival and the viability of immature oocytes vitrified using super-cooled liquid nitrogen. Immature oocytes were randomly allocated to three groups: (i) non-vitrified control group, (ii) vitrified in normal (-196 degrees C) liquid nitrogen (LN(2)) and (iii) vitrified in super-cooled LN(2) (< or =-200 degrees C). Open-pulled glass micropipettes were used as vitrification containers. Immature oocytes were in vitro-matured, fertilized and cultured to the blastocyst stage. In vitro viability was assessed by cleavage and blastocyst rates on days 2 and 7 of culture respectively. Vitrified blastocysts derived from the immature vitrified oocytes were directly transferred to synchronous recipients. The in vitro embryo development of vitrified immature oocytes was not influenced by the LN(2) state. After direct transfer (one embryo per recipient) of 16 embryos obtained from immature vitrified oocytes (eight from each vitrified group), two healthy calves were born in each group. These results indicated that vitrification of immature bovine oocytes using glass micropipettes under normal or super-cooled LN(2), resulted in viable blastocysts and live calves following in vitro embryo production.


Assuntos
Bovinos/fisiologia , Criopreservação/veterinária , Transferência Embrionária/veterinária , Oócitos , Resultado da Gravidez/veterinária , Animais , Animais Recém-Nascidos , Blastocisto/efeitos dos fármacos , Blastocisto/fisiologia , Bovinos/embriologia , Criopreservação/métodos , Crioprotetores/farmacologia , Técnicas de Cultura Embrionária/veterinária , Transferência Embrionária/métodos , Feminino , Fertilização in vitro/veterinária , Vidro , Microtúbulos , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Gravidez , Distribuição Aleatória
19.
Anim Reprod Sci ; 99(3-4): 377-83, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16870364

RESUMO

The aim of this study was to determine the influence of two ethylene glycol-based vitrification solutions on in vitro and in vivo survival after in-straw cryoprotectant dilution of vitrified in vitro-produced bovine embryos. Day-7 expanded blastocysts were selected according to diameter (> or = 180 microm) and osmotic characteristics and randomly assigned to one of three groups (i) VSa: vitrification in 40% EG+17.1% SUC+0.1% PVA; (ii) VSb: vitrification in 20% EG+20% DMSO; (iii) control: non-vitrified embryos. Vitrification was performed in hand-pulled glass micropipettes (GMP) and cryoprotectant dilution in 0.25 ml straws after warming in a plastic tube. Embryo viability was assessed by re-expansion and hatching rates after 72 h of IVC and by pregnancy rates after direct transfer of vitrified embryos. No differences in re-expansion rates were observed between vitrified groups after 24 h in culture (VSa=84.5%; VSb=94.8%). However, fewer VSa embryos (55.2%, P<0.05) hatched after 72 h than the VSb (75.8%) and control embryos (80.0%). To evaluate in vivo viability, vitrified embryos (VSa=20; VSb=21) were warmed under field conditions and individually transferred to synchronous recipients. Pregnancy rates (day 60) were similar between groups (VSa=20%; VSb=19%). Greater hatching rates occurred after 72 h of IVC for EG+DMSO than EG+SUC+PVA vitrification solutions. However, using a GMP vitrification container and in-tube warming, both solutions provided similar pregnancy rates after the in-straw cryoprotectant dilution and direct embryo transfer.


Assuntos
Blastocisto/efeitos dos fármacos , Bovinos/embriologia , Criopreservação/veterinária , Crioprotetores/farmacologia , Vidro , Animais , Blastocisto/fisiologia , Criopreservação/instrumentação , Transferência Embrionária/veterinária , Feminino , Fertilização in vitro/veterinária , Gravidez
20.
Braz. j. biol ; 82: 1-9, 2022. ilus, tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468536

RESUMO

Since the classic studies of Alexander Flemming, Penicillium strains have been known as a rich source of antimicrobial substances. Recent studies have identified novel metabolites produced by Penicillium sclerotiorum that have antibacterial, antifouling and pharmaceutical activities. Here, we report the isolation of a P. sclerotiorum (LM 5679) from Amazonian soil and carry out a culture-based study to determine whether it can produce any novel secondary metabolite(s) that are not thus-far reported for this genus. Using a submerged culture system, secondary metabolites were recovered by solvent extract followed by thin-layer chromatography, nuclear magnetic resonance, and mass spectroscopy. One novel secondary metabolite was isolated from P. sclerotiorum (LM 5679); the phenolic compound 5-pentadecyl resorcinol widely known as an antifungal, that is produced by diverse plant species. This metabolite was not reported previously in any Penicillium species and was only found once before in fungi (that time, in a Fusarium). Here, we discuss the known activities of 5-pentadecyl resorcinol in the context of its mode-of-action as a hydrophobic (chaotropicity-mediated) stressor.


Desde os estudos clássicos de Alexander Flemming, as cepas de Penicillium são conhecidas como uma fonte rica em substâncias antimicrobianas. Estudos recentes identificaram novos metabólitos produzidos pela espécie Penicillium sclerotiorum com atividades antibacteriana, anti-incrustante e farmacêutica. Aqui, relatamos o isolamento de uma colônia de P. sclerotiorum (LM 5679) do solo amazônico e relatamos também o estudo baseado em cultura para determinar se ele pode produzir qualquer novo metabólito (s) secundário (s) que não foram relatados até agora para este gênero. Usando um sistema de cultura submerso, os metabólitos secundários foram recuperados por extrato de solvente seguido por cromatografia em camada delgada, ressonância magnética nuclear e espectroscopia de massa. Um novo metabólito secundário foi isolado de P. sclerotiorum (LM 5679); o composto fenólico 5-pentadecil resorcinol que é amplamente conhecido como um antifúngico que é produzido por diversas espécies de plantas. Este metabólito não foi relatado anteriormente em nenhuma espécie de Penicillium, e foi encontrado apenas uma vez em fungos (Fusarium). Aqui, discutimos as atividades conhecidas do 5-pentadecil resorcinol no contexto de seu modo de ação como um estressor hidrofóbico (mediado pela caotropicidade).


Assuntos
Antifúngicos/isolamento & purificação , Compostos Fenólicos/análise , Penicillium/química , Fusarium
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA