Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
Más filtros

País/Región como asunto
Intervalo de año de publicación
1.
J Helminthol ; 96: e86, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36454026

RESUMEN

The giant African land snail, Achatina fulica, is an important invasive species in many countries, where it causes losses in biodiversity and agriculture, as well as impacting the health of both humans and animals, as the intermediate host of medically important nematodes. The present study is based on a comprehensive review of the literature on the nematodes that have been found in association with A. fulica, worldwide. We searched a number of different databases and used the findings to investigate the methods used to extract and identify the nematodes, their larval stages, and environment and collecting procedures of the infected molluscs. Between 1965 and 2021, 11 nematode species were recorded in association with A. fulica in 21 countries. Most of the studies recorded associations between A. fulica and Angiostrongylus cantonensis, which causes cerebral angiostrongyliasis in humans and Aelurostrongylus abstrusus, which provokes pneumonia in felines. The nematodes were extracted primarily by artificial digestion with hydrochloric acid or pepsin, and identified based on their morphology or through experimental infection to obtain the adult. In most cases, the nematodes were at larval stage L3, and the infected A. fulica were collected from anthropogenic environments. The results demonstrate the importance of A. fulica as a host of nematodes of medical and veterinary importance, as well the contribution of anthropogenic environments to the occurrence of the parasites, and give information about the different methods used to collect and identify the nematodes found associated with this species.


Asunto(s)
Angiostrongylus cantonensis , Infecciones por Strongylida , Adulto , Humanos , Animales , Gatos , Aves , Alimentos , Infecciones por Strongylida/veterinaria , Larva , Caracoles
2.
Reprod Fertil Dev ; 29(6): 1144-1154, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27166082

RESUMEN

The aim of the present study was to evaluate the effect of anti-Müllerian hormone (AMH), with and without FSH, on the in vitro development of isolated caprine preantral follicles, as well as follicular steroid production and mRNA levels of AMH, hormone receptors (AMH and FSH), CYP19A1 (cytochrome P450, family 19, subfamily A, polypeptide 1), CYP17 (cytochrome P450, family 17, subfamily A, polypeptide 1), HSD3B (3-beta-hydroxysteroid dehydrogenase) and Myc (myelocytomatosis oncogene). Isolated secondary follicles were cultured in minimum essential medium alpha (α-MEM+) alone or supplemented with 50ng mL-1 AMH and/or 100ng mL-1 FSH added sequentially on different days of culture. Follicles were cultured for a total of 18 days, with different media during the first (Days 0-9) and second (Days 10-18) halves of the culture period, resulting in six treatment groups, as follows: α-MEM+/α-MEM+, FSH/FSH, AMH/AMH, AMH+FSH/AMH+FSH, AMH/FSH, and FSH/AMH. Follicle development was evaluated on the basis of follicular growth, oocyte maturation and steroid secretion. There was a decrease in follicular growth rate in the AMH, AMH+FSH and AMH/FSH treatment groups compared with α-MEM+ and FSH treatment groups (P<0.05). However, the different culture conditions had no effect on rates of meiotic resumption and steroid secretion (P>0.05). Moreover, follicles cultured in the presence of FSH had lower levels of AMH receptor type II (AMHRII) mRNA compared with non-cultured control (freshly isolated follicles), and the AMH and AMH/FSH treatment groups. In conclusion, AMH reduces the follicular growth rate of isolated goat preantral follicles in vitro without affecting follicular survival.


Asunto(s)
Hormona Antimülleriana/metabolismo , Hormona Folículo Estimulante/metabolismo , Regulación del Desarrollo de la Expresión Génica , Oogénesis , Folículo Ovárico/metabolismo , Receptores de HFE/agonistas , Receptores de Péptidos/agonistas , Receptores de Factores de Crecimiento Transformadores beta/agonistas , Mataderos , Animales , Hormona Antimülleriana/genética , Hormona Antimülleriana/farmacología , Brasil , Bovinos , Proliferación Celular/efectos de los fármacos , Tamaño de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cruzamientos Genéticos , Estradiol/metabolismo , Femenino , Hormona Folículo Estimulante/genética , Hormona Folículo Estimulante/farmacología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Cabras , Humanos , Oogénesis/efectos de los fármacos , Folículo Ovárico/citología , Folículo Ovárico/efectos de los fármacos , Progesterona/metabolismo , Receptores de HFE/genética , Receptores de HFE/metabolismo , Receptores de Péptidos/genética , Receptores de Péptidos/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacología , Testosterona/metabolismo , Técnicas de Cultivo de Tejidos
3.
J Fish Biol ; 91(1): 346-353, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28543076

RESUMEN

This study evaluated the reproductive characteristics of pike-characids, Boulengerella cuvieri, during the hydrological cycle in the Xingu River, eastern Amazon. The sex ratio was 1:1 and the gonado-somatic index and relative frequency of maturation stages indicate a short breeding season of single phase spawning that coincides with a filling and flood period. Mean standard length at first sexual maturity for female B. cuvieri was estimated to be 22·9 cm.


Asunto(s)
Characiformes/fisiología , Reproducción/fisiología , Animales , Brasil , Femenino , Inundaciones , Masculino , Ríos , Estaciones del Año , Razón de Masculinidad , Maduración Sexual
4.
Reprod Domest Anim ; 51(6): 997-1009, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27650787

RESUMEN

This study aimed to establish a culture system that improves the in vitro development of caprine preantral follicles. In a first experiment, follicles were encapsulated as a single unit per bead and cultured singly or in groups or with five follicles in the same alginate (ALG) bead for 18 days. In a subsequent experiment, the "five follicles per bead" design was chosen to culture in ALG, fibrin-alginate (FA) or hyaluronate (HA) for 18 days. In a third experiment, we chose the five follicles per bead in FA to culture for 30 days. The culture set-up of five follicles per ALG bead increased antrum formation and follicle diameter compared to the other culture designs (p < .05). Moreover, under this condition, 44.44% of the oocytes from in vitro cultured preantral follicles reached meiotic resumption. A significant increase of follicle diameter occurred in attachment system and FA (p < .05), but the ALG condition reached the highest among all groups on day 18 (p < .05). Follicles encapsulated in matrix produced more estradiol and progesterone than attachment system (p < .05). The expression of MMP-9 mRNA was higher in FA than in other groups (p < .05) and similar to antral follicles from in vivo control (p > .05). Only FA group resulted in oocytes matured. After 30 days, oocytes from preantral follicles in vitro grown in FA developed to eight-cell parthenotes. In conclusion, a culture system using FA supported the development of caprine preantral follicles cultured in group and included in the same bead of hydrogel, improving the oocyte maturation and producing parthenotes.


Asunto(s)
Alginatos/farmacología , Fibrina/farmacología , Cabras/fisiología , Técnicas de Maduración In Vitro de los Oocitos/veterinaria , Oocitos/efectos de los fármacos , Folículo Ovárico/fisiología , Alginatos/química , Animales , Femenino , Fibrina/química , Ácido Glucurónico/química , Ácido Glucurónico/farmacología , Ácidos Hexurónicos/química , Ácidos Hexurónicos/farmacología , Hidrogeles/química , Hidrogeles/farmacología , Oocitos/metabolismo , Partenogénesis
5.
Reprod Domest Anim ; 51(1): 59-68, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26660854

RESUMEN

BMP-6 has been found to be important to ovarian cells and oocyte, as well as to uterus. Thus, this study investigated the effect of bone morphogenetic protein (BMP-6) and recombinant follicle-stimulating hormone (rFSH) alone or in combination on the in vitro culture (IVC) of isolated caprine secondary follicles (Experiment 1) and the mRNA levels for BMP receptors/Smad signalling pathway (BMPR1A, BMPR2, SMAD1, SMAD4, SMAD5, SMAD6, SMAD7 and SMAD8) in vivo and in vitro using BMP-6 (Experiment 2). Secondary follicles were cultured in αMEM(+) alone (control medium) or supplemented with BMP-6 at 1 or 10 ng/ml and rFSH alone or the combination of both BMP-6 concentrations and rFSH. The results from Experiment 1 showed that the antrum formation rate was higher in the BMP-6 at 1 ng/ml (p < 0.05) than in MEM. In Experiment 2, the mRNA expression for BMPR2, SMAD1, SMAD5 and SMAD6 was detected in non-cultured control and after in vitro culture (MEM and 1 ng/ml BMP-6); while the expression of SMAD7 and SMAD8 mRNA was only detected after IVC, SMAD4 was only detected in the BMP-6 at 1 ng/ml treatment. In conclusion, the low BMP-6 concentration positively influenced antrum formation and ensured normal mRNA expression for BMP receptor and Smads after IVC of caprine secondary follicles.


Asunto(s)
Proteína Morfogenética Ósea 6/farmacología , Cabras/fisiología , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , Transducción de Señal/efectos de los fármacos , Animales , Receptores de Proteínas Morfogenéticas Óseas/genética , Femenino , Hormona Folículo Estimulante/farmacología , ARN Mensajero/análisis , Proteínas Recombinantes/farmacología , Técnicas de Cultivo de Tejidos/veterinaria
6.
Zygote ; 23(4): 475-84, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24666604

RESUMEN

The aim of this study was to evaluate the influence of two-dimensional (2D) and three-dimensional (3D) alginate culture systems on in vitro development of pre-antral caprine follicles. In addition, the influence of the reproductive age of the ovary donor on the in vitro culture success was investigated. Pre-antral follicles from pre-pubertal or adult goats were isolated and cultured directly on a plastic surface (2D) or encapsulated in an alginate-based matrix (3D). After 18 days, the oocytes underwent in vitro maturation (IVM) and in vitro fertilization (IVF) to produce embryos. The 3D system showed higher rates of follicle survival, lower rates of oocyte extrusion, and a greater number of recovered oocytes for IVM and IVF (P < 0.05). Only pre-antral follicles from adult animals produced MII oocytes and embryos. The estradiol concentrations increased from day 2 to day 12 of culture in all groups tested (P < 0.05). Conversely, progesterone concentrations were lower in 3D-cultured follicles than in 2D-cultured follicles, with differences on days 2 and 6 of culture (P < 0.05). We provide compelling evidence that a 2D or 3D alginate in vitro culture system offers a promising approach to achieving full in vitro development of caprine pre-antral follicles to produce mature oocytes that are capable of fertilization and viable embryos.


Asunto(s)
Técnicas de Cultivo de Célula/métodos , Oocitos/fisiología , Folículo Ovárico/crecimiento & desarrollo , Factores de Edad , Alginatos , Animales , Técnicas de Cultivo de Célula/instrumentación , Supervivencia Celular , Estradiol/metabolismo , Femenino , Fertilización In Vitro , Ácido Glucurónico , Cabras , Ácidos Hexurónicos , Técnicas de Maduración In Vitro de los Oocitos/métodos , Masculino , Oocitos/citología , Folículo Ovárico/fisiología , Pubertad
7.
J Chem Phys ; 141(13): 134309, 2014 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-25296808

RESUMEN

We consider the analytical representation of the potential energy surfaces of relevance for the intermolecular dynamics of weakly bound complexes of chiral molecules. In this paper we study the H2O2-Ng (Ng=He, Ne, Ar, Kr, and Xe) systems providing the radial and the angular dependence of the potential energy surface on the relative position of the Ng atom. We accomplish this by introducing an analytical representation which is able to fit the ab initio energies of these complexes in a wide range of geometries. Our analysis sheds light on the role that the enantiomeric forms and the symmetry of the H2O2 molecule play on the resulting barriers and equilibrium geometries. The proposed theoretical framework is useful to study the dynamics of the H2O2 molecule, or other systems involving O-O and S-S bonds, interacting by non-covalent forces with atoms or molecules and to understand how the relative orientation of the O-H bonds changes along collisional events that may lead to a hydrogen bond formation or even to selectivity in chemical reactions.

8.
J Radiol Prot ; 34(2): 339-46, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24705248

RESUMEN

The Waste Management Department of Nuclear and Energy Research Institute (IPEN) is responsible for the safety management of the waste generated at all internal research centers and that of other waste producers such as industry, medical facilities, and universities in Brazil. These waste materials, after treatment, are placed in an interim storage facility. Among them are (226)Ra needles used in radiotherapy, siliceous cake arising from conversion processes, and several other classes of waste from the nuclear fuel cycle, which contain Ra-226 producing (222)Rn gas daughter.In order to estimate the effective dose for workers due to radon inhalation, the radon concentration at the storage facility has been assessed within this study. Radon measurements have been carried out through the passive method with solid-state nuclear track detectors (CR-39) over a period of nine months, changing detectors every month in order to determine the long-term average levels of indoor radon concentrations. The radon concentration results, covering the period from June 2012 to March 2013, varied from 0.55 ± 0.05 to 5.19 ± 0.45 kBq m(-3). The effective dose due to (222)Rn inhalation was further assessed following ICRP Publication 65.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Contaminantes Radiactivos del Aire/análisis , Contaminación del Aire Interior/análisis , Exposición a Riesgos Ambientales/análisis , Sitios de Residuos Peligrosos/estadística & datos numéricos , Residuos Radiactivos/análisis , Radón/análisis , Carga Corporal (Radioterapia) , Brasil , Humanos , Dosis de Radiación , Monitoreo de Radiación/métodos
9.
Nanoscale ; 16(5): 2337-2346, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38086667

RESUMEN

The recent synthesis of a two-dimensional quasi-hexagonal-phase monolayer network of C60 molecules, known as qHPC60, holds significant promise for future semiconductor applications. However, the mechanism behind charge transport in these networks remains unknown. In this study, we developed a Holstein-Peierls Hamiltonian model to investigate charge transport in qHPC60, incorporating both local and non-local electron-phonon couplings. Our computational approach involved identifying suitable semi-empirical parameters to realize the formation of stable polarons in this material. The results unveiled the formation of stable large polarons as the primary carriers in the charge transport throughout qHPC60. To explore polaron transport properties, we conducted dynamic simulations within the picosecond time scale while subjecting the system to an external electric field. Our analysis emphasized the substantial influence of anisotropy on shaping mobile polarons, with an anisotropy coefficient of at least 50%. The polarons exhibited velocities within the acoustic regime ranging from 0.5-1.5 nm ps-1. While these velocities are comparable to those observed in high-end organic molecular crystals, they are considerably lower than those in graphene and conducting polymers. With qHPC60 possessing a semiconducting band gap of approximately 1.6 eV, our findings shed light on its potential application in flat electronics, overcoming the null-gap predicament of graphene.

10.
Braz J Biol ; 83: e274620, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38422260

RESUMEN

Achatina fulica is a species native to East Africa, considered one of the 100 worst invasive alien species in the world. The present study investigated the population of the snail, A. fulica, in a peri-urban area adjacent to the Fiocruz Atlantic Forest Biological Station (EFMA), in Jacarepaguá, Rio de Janeiro state, Brazil, focusing on population dynamics and the nematodes associated with this species. To this end, specimens were collected during four climatic seasons of the years 2021 and 2022 in three fixed 20 m × 10 m plots. The abundance of A. fulica in these areas was evaluated in relation to a set of environmental variables (temperature, relative humidity air, and soil pH and calcium). The abundance of snails infected by nematodes was also evaluated in relation to the season and body size of the specimens. The molluscs were found by active search, and standardized (15 minutes/three collections). Nematode larvae were extracted from the specimens by artificial digestion and identified by their external morphology and the sequencing of molecular markers. A total of 280 specimens of A. fulica were collected, with the highest abundances being recorded in the autumn and summer, although no significant relationship was found between the number of specimens collected and the environmental variables. Overall, 192 snails were infected by nematodes: Angiostrongylus cantonensis, Cruzia tentaculata and free-living nematodes, including Caenorhabditis briggsae. These findings demonstrate the epidemiological importance of the study area and the need to implement educational measures in the community, with the aim of controlling the local A. fulica population, thereby minimizing the risk of parasitic infection in the local human population.


Asunto(s)
Angiostrongylus cantonensis , Caracoles , Infecciones por Strongylida , Animales , Humanos , Brasil/epidemiología , Especies Introducidas , Dinámica Poblacional
11.
Clin Exp Immunol ; 171(2): 210-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23286948

RESUMEN

Previous studies have demonstrated that cells from both multi-drug-resistant tuberculosis (MDR-TB) and non-tuberculous mycobacteria (NTM) patients respond poorly to mycobacterial antigens in vitro. In the present study, we compared the in vitro response of cells isolated from sensitive TB (NR-TB)-, MDR-TB- and NTM-infected patients. Analysis of T cell phenotype ex vivo revealed that both MDR-TB and NTM patients present an increased percentage of CD4(+) CD25(+-) forkhead box protein 3 (FoxP3)(+) and CD4(+) CD25(+) CD127(-) regulatory T (T(reg) ) cells when compared to NR-TB. Increased numbers of T(reg) cells and interleukin (IL)-10 serum levels were detected in MDR-TB, whereas elevated serum transforming growth factor (TGF)-ß was found in the NTM group. Cells of MDR-TB patients stimulated with early secretory antigenic target (ESAT)-6, but not purified protein derivative (PPD), showed a lower frequency of CD4(+) /interferon (IFN)-γ(+) T cells and enhanced CD4(+) CD25(+) FoxP3(+) , CD4(+) CD25(+) CD127(-) and CD4(+) CD25(+) IL-10(+) T cell population. In addition, increased IL-10 secretion was observed in cultured MDR-TB cells following ESAT-6 stimulation, but not in NR-TB or NTM patients. In vitro blockade of IL-10 or IL-10Rα decreased the CD4(+) CD25(+) FoxP3(+) frequencies induced by ESAT-6 in MDR-TB, suggesting a role of IL-10 on impaired IFN-γ responses seen in MDR-TB. Depletion of CD4(+) CD25(+) T lymphocytes restored the capacity of MDR-TB T cells to respond to ESAT-6 in vitro, which suggests a potential role for T(reg) /T regulatory 1 cells in the pathogenesis of MDR-TB. Together, our results indicate that although the similarities in chronicity, NTM- and MDR-TB-impaired antigenic responses involve different mechanisms.


Asunto(s)
Tolerancia Inmunológica , Subgrupos de Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Tuberculosis Resistente a Múltiples Medicamentos/inmunología , Tuberculosis Pulmonar/inmunología , Adulto , Anciano , Antígenos Bacterianos/inmunología , Antígenos CD/metabolismo , Proteínas Bacterianas/inmunología , Células Cultivadas , Citocinas/inmunología , Femenino , Factores de Transcripción Forkhead/metabolismo , Humanos , Inmunofenotipificación , Isoniazida/uso terapéutico , Masculino , Persona de Mediana Edad , Rifampin/uso terapéutico , Subgrupos de Linfocitos T/efectos de los fármacos , Linfocitos T Reguladores/efectos de los fármacos , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/microbiología , Adulto Joven
12.
Braz J Biol ; 83: e278007, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38126483

RESUMEN

Low density sugarcane plantation (LDSP) has been implemented by some sugarcane producers in Brazil, aiming to save seeds and operational costs. The study was carried out in the municipality of Areia, Paraíba, Brazil. Five planting densities were used, varying from 5 to 25 m-2 of buds arranged in randomized blocks, with four replications. Data were measured annually over three cultivation cycles (2017 to 2020), during which the field was fertilized with NPK and the harvests were carried out manually without prior burning. The lower planting density presents higher productivity only in the cane plant (101.03 t ha-1) due to the higher plant height (2.37 m) and the higher number of stalks (11 stalks m-2), suggesting that these variables are due to the greater availability of light, water and photosynthate. However, there is a drastic reduction in sugarcane yield for this lower population in the 2nd ratoon by up to 65.62%, which is correlated with number of stalks per meter. We demonstrate the agronomic viability of LDSP in the population of 10 buds m-2 in relation to conventional planting of sugarcane until the 2nd ratoon. Data are important for future studies to present additional considerations for other production factors, such as the effects of mechanized harvesting and the management of nutrients and water, assessing the sustainability of this large-scale planting system.


Asunto(s)
Saccharum , Agricultura , Semillas , Agua , Brasil
13.
Reprod Fertil Dev ; 24(3): 490-500, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22401281

RESUMEN

The aim of this study was to evaluate the effect of follicular fluid collected from bovine dominant follicles (bFF) on the in vitro development of goat preantral follicles and determine the best time to add this supplement to the culture medium. The preantral follicles were isolated and randomly distributed into four treatments in absence (control) or presence of 10% of bFF added on Days 0 (FF0-18), 6 (FF6-18) or 12 (FF12-18) of culture onwards. After 18 days, follicular development was assessed based on follicular survival, antral cavity formation, increased follicular diameter as well as fully grown oocyte (>110 µm) viability and meiosis resumption. The oocytes from the cultured follicles were in vitro-matured and processed for fluorescence or ultrastructural analysis. The results showed that on Day 18 the treatment FF0-18 had a significantly higher (P<0.05) survival than control and FF12-18, but not FF6-18. The addition of bFF at the beginning of culture (FF0-18 and FF6-18) promoted a high percentage of follicular growth, meiosis resumption and early antrum formation. Moreover, this study described for the first time the ultrastructural analysis of caprine oocytes grown in vitro. This evaluation revealed that in the presence of bFF on (FF0-18) the in vitro-grown oocytes presented normal organelle distribution and well-defined, intact plasma and nuclear membranes. In conclusion, bFF originating from dominant follicles maintain the survival and promote the in vitro growth of goat preantral follicles when added at the beginning of culture.


Asunto(s)
Medios de Cultivo Condicionados/farmacología , Líquido Folicular/fisiología , Cabras/fisiología , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , Animales , Bovinos , Aumento de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Femenino , Oocitos/citología , Oocitos/efectos de los fármacos , Oocitos/crecimiento & desarrollo , Oocitos/ultraestructura , Oogénesis/efectos de los fármacos , Oogénesis/fisiología , Folículo Ovárico/citología , Folículo Ovárico/ultraestructura , Distribución Aleatoria
14.
Genet Mol Res ; 11(3): 2432-40, 2012 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-22782627

RESUMEN

Males of Zophobas aff. confusus and Nyctobates gigas (Tenebrionidae) collected in the State of Pernambuco, Brazil, were studied through conventional staining, C-banding, silver nitrate impregnation (AgNO3), and the base specific fluorochromes CMA3 and DAPI. Z. aff. confusus was found to have 2n = 20 (9+Xyp) while N. gigas exhibited 2n = 18 (8+neoXY). Large pericentromeric blocks of constitutive heterochromatin (CH) were detected throughout the autosomal complement of the two species, except in one autosomal pair of N. gigas in which no heterochromatic block was observed. The sex chromosomes of both species were almost totally heterochromatic. Double staining with CMA3/DA (distamycin) and DAPI/DA marked CH in Z. aff. confusus. However, DAPI staining was more intense. N. gigas was found to possess blocks of CH-positive CMA3 and homogeneous DAPI. AgNO3 staining also revealed differences between the two species. In Z. confusus an NOR was observed in the sexual bivalent Xyp and N. gigas was found to have an autosomal NOR.


Asunto(s)
Escarabajos/genética , Análisis Citogenético , Animales , Bandeo Cromosómico , Masculino , Meiosis/genética , Metafase/genética , Espermatogonias/citología
15.
Reprod Domest Anim ; 47(1): 20-5, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21518029

RESUMEN

This study quantified Fibroblast growth factor 2 (FGF-2) mRNA and localized FGF-2 protein in different categories of follicles isolated from goat ovaries. In addition, we verified the effects of this factor on the in vitro culture of preantral follicles isolated from goats. For mRNA quantification, we performed real-time PCR using primordial, primary and secondary follicles, as well as cumulus-oocyte complexes (COCs) and mural granulosa and theca cells of small and large antral follicles. For FGF-2 protein localization, the ovaries were subjected to conventional immunohistochemical procedures. Preantral follicles were isolated and cultured in vitro for 12 days in either control (basic) or supplemented with FGF-2 medium. The expression of FGF-2 mRNA was detected in all categories of follicles and there was no difference in preantral follicles and COCs or granulosa/theca cells from small and large antral follicles. However, in large antral follicles, COCs showed expression levels significantly lower than in granulosa/theca cells (p < 0.05). We observed moderate expression of FGF-2 protein in preantral follicles but not in granulosa cells of primordial follicles and theca cells of secondary follicles. In both small and large antral follicles, strong, moderate and weak staining was observed in oocytes, granulosa and theca cells, respectively. The addition of FGF-2 caused a significant increase in the daily follicular growth rate compared to the control group. We conclude that FGF-2 mRNA is expressed throughout follicular development and that its protein can be found in different patterns in preantral and antral follicles. Furthermore, FGF-2 increases the follicular growth rate in vitro.


Asunto(s)
Factor 2 de Crecimiento de Fibroblastos/genética , Factor 2 de Crecimiento de Fibroblastos/farmacología , Expresión Génica , Cabras , Folículo Ovárico/fisiología , Ovario/química , Animales , Células Cultivadas , Medios de Cultivo , Células del Cúmulo/fisiología , Femenino , Factor 2 de Crecimiento de Fibroblastos/análisis , Inmunohistoquímica , Folículo Ovárico/química , Folículo Ovárico/efectos de los fármacos , ARN Mensajero/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria
16.
Cell Tissue Res ; 346(2): 273-81, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21987221

RESUMEN

The aim of this study was to evaluate the effect of vascular endothelial growth factor-A(165) (VEGF-A(165)) on the in vitro development of goat secondary preantral follicles. Preantral follicles (≥150 µm in diameter) were isolated from the ovaries of adult mixed-breed goats and individually cultured for 18 days in αMEM in the absence (control) or presence of VEGF-A(165) at concentrations of 10 ng/ml (VEGF10) and 100 ng/ml (VEGF100). Analyses of follicular survival, diameter, antrum formation and rate of daily growth were performed every 6 days. At the end of the culture period, morphologically normal oocytes (≥110 µm in diameter) were taken for in vitro maturation (IVM). The results demonstrated that all follicles presented oocytes and granulosa cells that were morphologically normal and after labeling with calcein-AM, high rates of oocyte viability were observed in all treatments. The follicular diameter and the growth rate achieved in the presence of VEGF10 were higher than those of the control. Both treatments with VEGF-A(165) showed higher rates of oocyte recovery for IVM when compared with the control. Moreover, only the addition of VEGF-A(165) permitted oocytes grown in vitro to reach metaphase II. Thus, the addition of VEGF-A(165) to the culture medium improves the development of goat preantral follicles cultured in vitro, allowing the production of mature oocytes.


Asunto(s)
Oocitos/citología , Oocitos/efectos de los fármacos , Folículo Ovárico/citología , Folículo Ovárico/crecimiento & desarrollo , Factor A de Crecimiento Endotelial Vascular/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cromatina/metabolismo , Femenino , Cabras , Humanos , Meiosis/efectos de los fármacos , Oocitos/metabolismo , Folículo Ovárico/efectos de los fármacos
17.
J Viral Hepat ; 18(10): 692-9, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21914086

RESUMEN

Approximately 20% of hepatitis C virus (HCV) infected individuals clear the virus. Host factors that influence the course of HCV infection are still under investigation, and the data on the association of human leukocyte antigen (HLA) alleles and HCV clearance are scarce and controversial. The aims of this study were to investigate whether HLA alleles are associated with clearance of HCV infection in a highly admixed Brazilian population and whether these associations could be influenced by ethnicity and route of infection. HLA-A, -B, -C, -DRB1 and -DQB1 genotyping were performed in 135 HCV-infected Brazilian patients among which 45 cleared HCV infection (cases) and 90 had persistent viral infection (controls). Controls were matched by sex, ethnicity (withes and non-whites) and route of infection (high infectious dose or low infectious dose). No significant association was identified between HLA alleles and the outcome of HCV infection when analyzing the sample as a single group. However, a new protective association of HLA-DQB1*04 (P = 0.006; P(c) = 0.030) and a rarely described association of HLA-DRB1*08 (P = 0.004; P(c) = 0.048) were found only among white patients. The DRB1*11 allele, previously reported in homogeneous population, was associated with HCV clearance (P = 0.020) only among patients with expected high-dose exposure. These findings confirm the influence of ethnicity on the associations of HLA with spontaneous viral clearance of HCV infection and emphasize the possible influence of route of infection in this process.


Asunto(s)
Resistencia a la Enfermedad , Predisposición Genética a la Enfermedad , Antígenos HLA/genética , Antígenos HLA/inmunología , Hepatitis C/genética , Hepatitis C/inmunología , Adulto , Anciano , Brasil , Etnicidad , Femenino , Frecuencia de los Genes , Genotipo , Hepatitis C/transmisión , Humanos , Masculino , Persona de Mediana Edad
18.
Zygote ; 19(3): 205-14, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21205389

RESUMEN

This study evaluated the expression of FSH receptors (FSHR) in the different stages of goat follicle development and investigated whether the addition of increasing concentrations of FSH throughout the culture period influences the survival, growth and antral formation of in vitro-cultured caprine preantral follicles. The expression of FSHR was analysed before and after culturing follicles using real-time RT-PCR. For the culture, preantral follicles (≥150 µm) were isolated from ovarian fragments and cultured for 18 days in α-MEM+ alone or associated with recombinant FSH (rFSH: 100 or 1000 ng/ml), or in α-MEM+ supplemented with increasing concentrations of FSH throughout culture periods as follows: (a) sequential medium 1: FSH 100 ng/ml (from day 0 to 6), FSH 500 ng/ml (from day 6 to 12) and FSH 1000 ng/ml (from day 12 to 18); and (b) sequential medium 2: FSH 500 ng/ml (from day 0 to 9) and 1000 ng/ml (from day 9 to 18). Follicle development was evaluated on the basis of antral cavity formation, follicular and oocyte growth, and cumulus-oocyte complex health. The expression of FSHR in isolated caprine follicles increased from the preantral to antral phase. Regarding the culture, after 18 days, sequential medium 1 promoted follicular survival, antrum formation and a reduction in oocyte extrusion. Both sequential media promoted a higher rate of meiotic resumption compared with the other treatments. In conclusion, the addition of increased concentrations of FSH (sequential medium) has a significant impact on the in vitro development of caprine preantral follicles.


Asunto(s)
Folículo Ovárico/citología , Folículo Ovárico/fisiología , Receptores de HFE/genética , Animales , Células Cultivadas , Medios de Cultivo , Femenino , Hormona Folículo Estimulante/farmacología , Cabras , Hormonas/farmacología , Técnicas In Vitro , Oocitos/citología , Oocitos/efectos de los fármacos , Folículo Ovárico/efectos de los fármacos , ARN Mensajero/genética , Receptores de HFE/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
19.
Toxicon ; 199: 87-93, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34126124

RESUMEN

Snakebite accidents are a public health problem that affects the whole world, causing thousands of deaths and amputations each year. In Brazil, snakebite envenomations are caused mostly by snakes from the Bothrops genus. The local symptoms are characterized by pain, swelling, ecchymosis, and hemorrhages. Systemic disturbances can lead to necrosis and amputations. The present treatment consists of intravenous administration of bothropic antivenom, which is capable of reversing most of the systemic symptoms, while presenting limitations to treat the local effects, such as hemorrhage and to neutralize the snake venom serine protease (SVSP). In this context, we aimed to evaluate the activity of selective serine protease inhibitors (pepC and pepB) in combination with the bothropic antivenom in vivo. Further, we assessed their possible synergistic effect in the treatment of coagulopathy and hemorrhage induced by Bothrops jararaca venom. For this, we evaluated the in vivo activity in mouse models of local hemorrhage and a series of in vitro hemostasis assays. Our results showed that pepC and pepB, when combinated with the antivenom, increase its protective activity in vivo and decrease the hemostatic disturbances in vitro with high selectivity, possibly by inhibiting botropic proteases. These data suggest that the addition of serine protease inhibitor to the antivenom can improve its overall potential.


Asunto(s)
Bothrops , Venenos de Crotálidos , Animales , Antivenenos/farmacología , Antivenenos/uso terapéutico , Brasil , Venenos de Crotálidos/toxicidad , Hemorragia/inducido químicamente , Hemorragia/tratamiento farmacológico , Ratones , Inhibidores de Serina Proteinasa/farmacología , Inhibidores de Serina Proteinasa/uso terapéutico
20.
Animal ; 15(1): 100055, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33516019

RESUMEN

Maternal nutrition affects the development of the fetus and postnatal performance of the calf. Methionine may play a critical role in developmental programming and is likely deficient in beef cows fed low-quality forage. The objective of this study was to determine the effect of metabolizable methionine supply to lactating beef cows during the periconception period on performance of cows, calves, and subsequent offspring. This project involved two consecutive production cycles commencing at calving in which dietary treatments were fed to cows during the periconception period along with measurements on cows and initial calves in Production Cycle 1, and measurements on subsequent calves in Production Cycle 2. Brangus-Angus crossbred lactating beef cows (N = 108; age = 6.4 (2.8) year) were stratified by previous calving date and assigned to one of three supplements: (1) control, molasses plus urea at 2.72 kg/day as fed, (2) fishmeal, 2.27 kg/day molasses plus urea plus 0.33 kg/day as fed of fishmeal, and (3) methionine, 2.72 kg/day of molasses plus urea plus 9.5 g/day of 2-hydroxy-4-(methylthio)-butanoic acid. Cows were fed supplements and low-quality limpograss (Hemarthria altissima) hay while grazing dormant bahiagrass (Paspalum notatum Flüggé) pastures during the 115-day periconception period from December 2014 to April 2015 in Production Cycle 1 only. Body weight change and milk yield of cows were measured during the periconception period in Production Cycle 1. Body weight of calves was measured at birth and weaning in both production cycles. Following weaning in Production Cycle 2, eight subsequent steer calves per treatment were individually housed for a 42-day metabolism experiment. Treatment did not affect (P > 0.10) BW change of cows, but cows fed methionine tended (P = 0.09) to produce more energy-corrected milk than control and fishmeal. Treatment did not affect (P > 0.10) 205-day adjusted weaning weight of calves in either production cycle. During the metabolism experiment, subsequent calves from dams fed fishmeal and methionine gained faster (P < 0.05) and had greater (P < 0.05) gain:feed than control calves. Methionine calves tended (P = 0.06) to have greater apparent total tract NDF and ADF digestibility and lesser (P < 0.05) blood glucose concentration than control and fishmeal calves. These data indicate that maternal methionine supply during the periconception period plays an important role in programming future performance of the offspring.


Asunto(s)
Metionina , Rumen , Alimentación Animal/análisis , Animales , Bovinos , Dieta/veterinaria , Suplementos Dietéticos , Femenino , Lactancia , Embarazo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA