RESUMEN
Resumo O objetivo desta pesquisa foi avaliar e quantificar a rugosidade do esmalte dentário após a remoção do adesivo residual ao retirar os bráquetes. Em 30 pré-molares humanos clinicamente saudáveis, foi realizada a colagem de bráquetes no centro da face vestibular. Após 24 horas, foram descolados e foi realizado o polimento do adesivo residual com três métodos diferentes: fresa multilaminada (12 lâminas) tronco-cônico com instrumentos rotativos em alta velocidade irrigada com água; fresa redonda com instrumentos rotativos em baixa velocidade (contra ângulo) sem irrigação e fresa de fibra de vidro com instrumentos rotativos em baixa velocidade (contra-ângulo) sem irrigação. Os elementos dentários foram observados com microscópio laser confocal antes da colagem dos bráquetes. Após a sua retirada e remoção do adesivo residual, a superfície do esmalte foi observada novamente com o microscópio laser confocal, e foi utilizado o software digital OLYMPUS OLS-4100 para realizar uma reconstrução tridimensional e medir a rugosidade deixada pelos diferentes métodos de polimento. Os resultados indicaram que a fresa multilaminada em alta velocidade irrigada com água é a que deixa a superfície com parâmetros de rugosidade mais baixos. Portanto, a fresa multilaminada seria o método mais indicado para eliminar a resina residual após a retirada dos bráquetes ao final de um tratamento ortodôntico (AU)
Abstract The aim of this research was to evaluate and quantify the roughness of the dental enamel after removing the residual adhesive when removing the brackets. In 30 clinically healthy human premolars, brackets were bonded in the center of the buccal face, which were detached in 24 hours, and the residual adhesive was polished with three different methods: multi-laminated bur (12 blades) conical trunk with rotary instruments in high speed irrigated with water, round milling cutter with low-speed rotary instruments (contra-angle) without irrigation, and glass milling (Fiber Glass) with low-speed rotary instruments (contra-angle) without irrigation. The dental elements were observed with a confocal laser microscope before bracket bonding. After its removal and removal of the residual adhesive, the enamel surface was observed again with the confocal laser microscope, and the OLYMPUS OLS-4100 digital software was used to perform a three-dimensional reconstruction and measure the roughness left by the different polishing methods. The results indicated that the multi-laminated cutter at high speed, irrigated with water, is the one that leaves the surface with lower roughness parameters. Therefore, the multilaminated bur would be the most suitable method to eliminate residual resin after removing brackets at the end of an orthodontic treatment. (AU)
Asunto(s)
Soportes Ortodóncicos , Fragaria , Esmalte Dental , Pulido DentalRESUMEN
La erupción dental es un proceso estrictamente regulado y programado espacial y temporalmente. El objetivo del trabajo fue estudiar el efecto de la exposición prenatal a fluoruro de sodio (NaF) sobre los eventos morfológicos y celulares que ocurren en el hueso supracoronal del primer molar de crías de rata durante la etapa preeruptiva. Se emplearon crías (n=6-8 por grupo) provenientes de madres que bebieron crónicamente agua con diferentes concentraciones de F- en forma de NaF durante la gestación y lactancia: control y NaF (50 mg/L). En cortes histológicos de la mandíbula de crías de 3 y 10 días se analizaron parámetros de histomorfometría estática en la zona supracoronal de la canastilla ósea a la altura del primer molar inferior: volumen óseo trabecular [BV/TV (%)], número de osteoclastos por milímetro (N.Oc/mm) y las variables indirectas: número de trabéculas [Tb.N (1/mm)], espesor [Tb.Th (µm)] y separación trabecular [Tb.Sp (µm)]. En crías de 15 días se midió el grado de erupción [TED (µm)] del primer molar inferior. Los resultados se analizaron con el test "t" de Student considerando diferencias significativas a p<0,05. El análisis histomorfométrico demostró un incremento en el BV/TV (%) del hueso supracoronal (p<0,01) asociado con disminución del N.Oc/mm (p<0,01) en crías de 3 y 10 días expuestas prenatalmente al F-. El grado de erupción dental fue menor en animales expuestos prenatalmente al F- en comparación con los controles (p<0,01). En conclusión, los resultados observados en la mandíbula de crías expuestas durante la etapa prenatal y posnatal temprana al F- sugieren un efecto disruptivo sobre la actividad resortiva necesaria para formación del canal eruptivo. (AU)
Tooth eruption is a tightly regulated and spatially and temporally programmed process. The aim of this study was to examine the effect of prenatal NaF exposure on the morphological and cellular events that occur in the supracoronal area of bony crypt of the first rat molar during the preeruptive stage. Offspring from two groups of rats were used (6-8 per group): Control and 50 mg/L NaF. The treatment was performed during pregnancy and lactation. Suckling pups were euthanized at 3-, 10- and 15-days-old by cervical dislocation. Mandibles were removed and histologically processed to obtain buccolingual sections stained with H&E. In sections of first mandibular molar of 3- and 10-days-old pups, the following static histomorphometric parameters were evaluated: trabecular bone volume [BV/TV (%)] and number of osteoclasts (N.Oc/mm). Also, indirect parameters were obtained: trabecular number [Tb.N (1/mm)], trabecular thickness [Tb.Th (µm)], and trabecular separation [Tb.Sp (µm)]. The degree of tooth eruption [TED (µm)] was determined. Results are expressed as mean ± SE and analyzed by Student t-test. Histomorphometric analysis showed an increase in the BV/TV (%) of the bone crypt of 3- and 10- days-old pups exposed to NaF (p <0.01); this increase was associated with a decrease in the N.Oc/mm (p <0.01). TED of mandibular first molar was lower in prenatal NaF exposed group than in control group (p<0.01). In conclusion, the increased BV/TV and the lower N.Oc observed in the bone crypt of 3- and 10- days-old pups from mothers treated with NaF suggested a disruptive effect triggered by F- on the formation events of the eruptive pathway in the offspring. (AU)
Asunto(s)
Humanos , Animales , Masculino , Femenino , Lactante , Preescolar , Ratas , Fluoruro de Sodio/efectos adversos , Erupción Dental , Osteoclastos/citología , Efectos Tardíos de la Exposición Prenatal , Fluoruro de Sodio/administración & dosificación , Fluoruro de Sodio/metabolismo , Fluoruro de Sodio/orina , Fluoruro de Sodio/síntesis química , Ratas Wistar , Mandíbula/anatomía & histología , Diente Molar/crecimiento & desarrollo , Fluorosis Dental/diagnósticoRESUMEN
We aimed to investigate the effect of maternal exposure to NaF on mandibular bone microarchitecture and phosphocalcic plasma parameters of the offspring. For this purpose, 10-, 15-, and 21-day-old pups (n = 6-8 per group) from two groups of mothers, control and NaF 50mg/L treated dams, were used. Plasma calcium (Ca) and phosphorus (P) levels and alkaline phosphatase activity (ALP) were measured. Fluoride concentration (F-) in bone and in stomach content was measured using potentiometry after isothermal distillation. Morphometric, histological, and histomorphometric analyses of the jaw bones were performed. Plasma Ca and P levels and ALP activity increased in 10-day and decreased in 21-day-old pups from NaF-treated mothers. Fluoride concentration in stomach content samples of 15- and 21-day-old nursing pups from mothers exposed to NaF in their drinking water was higher compared to that observed in control dam offspring. Mandibular F- content was higher in 21-day-old pups born to F--exposed dams compared to those observed in age-matched control pups. Mandibular area increased in 21-day-old pups born to treated mothers as compared to controls. Mandibular bone volume BV/TV (%) was higher in offspring from NaF-exposed dams than in controls at all the studied times. The increase in bone volume after exposure to F- was concomitant with the increase in trabecular thickness and the decrease in trabecular separation. Altogether, our results showed that exposure to NaF during gestation and lactation increased mandibular area and bone volume of pups, with concomitant changes in phosphocalcic parameters associated with the bone modeling process.
Asunto(s)
Lactancia/fisiología , Mandíbula/anatomía & histología , Mandíbula/efectos de los fármacos , Fluoruro de Sodio/administración & dosificación , Fluoruro de Sodio/farmacología , Animales , Animales Lactantes/fisiología , Femenino , Mandíbula/crecimiento & desarrollo , Embarazo , Ratas , Ratas Wistar , Fluoruro de Sodio/análisis , Estómago/químicaRESUMEN
The aim of this work was to analyse the parasympathetic control of submandibular saliva secretory response to cholinergic and peptidergic agonists in rats chronically exposed to constant light or repeated immobilization. Thirty two adult male Wistar rats were used: LL (8 rats exposed to constant light for 20 days), IMO (8 rats submitted to 14:10 h light: dark cycle and immobilized 2 hours daily for 7 days), and control (16 rats not exposed to stress and submitted to 14:10 hours light:dark cycle). Saliva was collected under anesthesia from the salivary ducts of submandibular glands under increasing doses of methacholine and substance P. Secretory responses (µg/saliva/mg dry weight gland) to methacholine were significantly higher in LL and IMO groups compared to control for the following doses (µg/kg body weight): 3 (153±9 versus 46±3, p<0.001 and 76±3 versus 40±3, p<0.001), 10 (379±23 versus 277±8, p<0.001 and 275±19 versus 250±10, p<0.01) and 30 (729±25 versus 695±19, p<0.05 and 1008±39 versus 640±20, p<0.001). Also, responses to substance P were significantly increased in LL and IMO groups compared to control for the following doses: 0.2 (80±3 versus 30±3, p<0.01 and 94±16 versus 31±3, p<0.001), 0.5 (328±20 versus 231±16, p<0.01 and 531±31 versus 219±25,p<0.001), 1 (681±35 versus 547±30, p<0.01 and 1031±63 versus 563±53, p<0.001), and 5 (2222±88 versus 1868±59, p<0.01 and 3230±145 versus 1921±218, p<0.001). In conclusion, supersensitivity of secretory response to both agonists suggests that chronic exposure of rats to stressors capable of activating the sympathetic adrenal system promotes inhibition of the parasympathetic control of salivary secretion.
Asunto(s)
Animales , Ratas , Saliva/metabolismo , Glándulas Salivales/fisiología , Salivación/fisiología , Agonistas Colinérgicos/administración & dosificación , Agonistas Adrenérgicos/administración & dosificación , Fototerapia , Ratas Wistar , Anestesia , LuzRESUMEN
Objetivo: Conocer y adentrarse en el estudio de violencia en las relaciones de pareja de los estudiantes de la ENEO-UNAM. Metodología: Se realizó un estudio descriptivo, la unidad de observación fueron alumnos de las carreras: Lic. en Enfermería y Lic. en Enfermería y Obstetricia, el muestreo fue no probabilístico. Se aplicó un cuestionario exprofeso Detección de violencia en pareja, de 15 reactivos. Resultados: Se estudiaron 112 alumnos, el 84.8% correspondió al género femenino, el 51% tienen menos 20 años, 37% tiene entre 20-23 y el 12% más de 23 años de edad. El 85.7% de las (os) alumnos, informo que tiene violencia emocional (controla su tiempo, celos y la acusa de ser le infiel), El 38.3% está en proceso de gestación de dependencia, el 15.8% tiene violencia económica, el 1.8% dijo tener violencia física, el 8.9% reportó violencia psicológica y solo se reportó un caso de violación por parte de su pareja. Conclusiones: Se confirma que existe violencia en las relaciones de pareja de tipo: emocional, dependencia, física, económica y sexual en los alumnos de enfermería, por lo que se debe de implementar y aplicar una intervención para disminuir esta. Es necesario fomentar que toda pareja llegue a acuerdos, donde se establezcan límites y distancias, sobre todo fomentar el mutuo respeto.
Introduction: The National Survey on the Dynamic of Household Relations (ENDIREH) 2011, reported that 46.1% of women over 15 have experienced violence by their partners. Objective: To determine and enter the study of violence in relationships of students ENEO-UNAM. Methodology: A descriptive study, the observation unit were students of the races: Lic. Nursing and Nursing and Midwifery, was non-probability sampling. a questionnaire exprofeso "Detection of violence as a couple" of 15 items was applied. Results: 112 students were studied, 84.8% were female, 51% are under 20 years, 37% are between 20- 23 and 12% over 23 years old. 85.7% of the (old) students reported having emotional violence (control your time, jealousy and accuses her of being unfaithful), 38.3% is in the making of dependence, 15.8% is economic violence, 1.8 % reported physical violence, 8.9% reported psychological violence and only one reported case of rape by an intimate partner. Conclusions: It is confirmed that there is violence in the relationships of type: emotional dependency, physical, economic and sexual in nursing students, so it must implement and apply an intervention to reduce this. It is necessary to encourage all couples reach agreements, which set limits and distances, especially foster mutual respect.
Asunto(s)
Adulto Joven , Violencia de Pareja/estadística & datos numéricos , Violencia/psicologíaRESUMEN
Actualmente, los problemas asociados al progresivo envejecimiento de la población son objeto de mayor atención, debido al aumento de las personas mayores, especialmente en las sociedades industrializadas. En el corto y el mediano plazo, estaremos frente a una población importante de adultos mayores; así, se tendrá que asumir la atención de este grupo poblacional. Estas personas pueden haber perdido piezas dentarias y la instalación de un aparato protésico constituye una solución para rehabilitar la función del sistema estomatognático. La terapia prostodóntica debe conservar la salud de los tejidos bucales y disminuir la resorción ósea. El descubrimiento y la prevención de las lesiones significará prolongar la esperanza y la calidad de vida de las personas de la tercera edad. La forma en que las personas perciben su salud bucal está relacionada con el bienestar; una boca saludable contribuye a que se sienta bien y ayuda a su satisfacción. Por ello, la percepción de salud bucal puede ser considerada como un factor predictor de la calidad de vida y se asocia a una variedad de indicadores de salud general y conductas saludables. Existen estudios que informan sobre la asociación entre la autopercepción de la salud bucal global con la autopercepción específica de limitaciones funcionales bucales. Los instrumentos para evaluar la calidad de vida relacionada con la salud bucal, son sensibles para detectar la influencia de los tratamientos odontológicos en la percepción del paciente sobre su salud bucal, lo que podría ser útil para relacionar satisfacción y percepción del paciente en relación a su rehabilitación(AU)
Asunto(s)
Femenino , Anciano , Anciano de 80 o más Años , Mucosa Bucal/lesiones , Enfermedades de la Boca/epidemiología , Prótesis Dental , Autoimagen , Salud Bucal , Cuidado Dental para Ancianos , Argentina , Crecimiento Demográfico , Calidad de Vida , Actitud Frente a la Salud , Envejecimiento/fisiologíaRESUMEN
Actualmente, los problemas asociados al progresivo envejecimiento de la población son objeto de mayor atención, debido al aumento de las personas mayores, especialmente en las sociedades industrializadas. En el corto y el mediano plazo, estaremos frente a una población importante de adultos mayores; así, se tendrá que asumir la atención de este grupo poblacional. Estas personas pueden haber perdido piezas dentarias y la instalación de un aparato protésico constituye una solución para rehabilitar la función del sistema estomatognático. La terapia prostodóntica debe conservar la salud de los tejidos bucales y disminuir la resorción ósea. El descubrimiento y la prevención de las lesiones significará prolongar la esperanza y la calidad de vida de las personas de la tercera edad. La forma en que las personas perciben su salud bucal está relacionada con el bienestar; una boca saludable contribuye a que se sienta bien y ayuda a su satisfacción. Por ello, la percepción de salud bucal puede ser considerada como un factor predictor de la calidad de vida y se asocia a una variedad de indicadores de salud general y conductas saludables. Existen estudios que informan sobre la asociación entre la autopercepción de la salud bucal global con la autopercepción específica de limitaciones funcionales bucales. Los instrumentos para evaluar la calidad de vida relacionada con la salud bucal, son sensibles para detectar la influencia de los tratamientos odontológicos en la percepción del paciente sobre su salud bucal, lo que podría ser útil para relacionar satisfacción y percepción del paciente en relación a su rehabilitación
Asunto(s)
Femenino , Anciano , Anciano de 80 o más Años , Prótesis Dental , Enfermedades de la Boca/epidemiología , Mucosa Bucal/lesiones , Salud Bucal , Autoimagen , Argentina , Actitud Frente a la Salud , Cuidado Dental para Ancianos , Envejecimiento/fisiología , Crecimiento Demográfico , Calidad de VidaRESUMEN
Spermatogenesis is disrupted in Graomys griseoflavus×Graomys centralis male hybrids. This study was aimed to determine whether morphological alterations in Leydig cells from hybrids accompany the arrest of spermatogenesis and cell death of germ cells and whether apoptotic pathways are also involved in the response of these interstitial cells. We used three groups of 1-, 2- and 3-month-old male animals: (1) G. centralis, (2) G. griseoflavus and (3) hybrids obtained by crossing G. griseoflavus females with G. centralis males. Testicular ultrastructure was analyzed by transmission electron microscopy. TUNEL was studied using an in situ cell death detection kit and the expression of apoptotic molecules by immunohistochemistry. The data confirmed arrest of spermatogenesis and intense apoptotic processes of germ cells in hybrids. These animals also showed ultrastructural alterations in the Leydig cells. Fas, FasL and calbindin D28k overexpression without an increase in DNA fragmentation was detected in the Leydig cells from hybrids. In conclusion, the sterility of Graomys hybrids occurs with ultrastructural changes in germ and Leydig cells. The enhancement of Fas and FasL is not associated with cell death in the Leydig cells. Probably the apoptosis in these interstitial cells is inhibited by the high expression of the antiapoptotic molecule calbindin D28k.
Asunto(s)
Apoptosis , Células Intersticiales del Testículo/fisiología , Roedores/anatomía & histología , Animales , Calbindinas/metabolismo , Proteína Ligando Fas/metabolismo , Femenino , Hibridación Genética , Células Intersticiales del Testículo/ultraestructura , Masculino , Túbulos Seminíferos/citología , Túbulos Seminíferos/metabolismo , Espermatogénesis , Receptor fas/metabolismoRESUMEN
Spermatogenic impairment and the apoptotic pathways involved in establishing sterility of male hybrids obtained from crossing Graomys griseoflavus females with Graomys centralis males were studied. Testes from G. centralis, G. griseoflavus and hybrids were compared at different ages. Terminal transferase-mediated dUTP nick-end labelling assay (TUNEL), Fas, Bax and cytochrome c labelling were used for apoptosis evaluation, and calbindin D(28k) staining as an anti-apoptotic molecule. In 1-month-old animals, spermatocytes were positive for all apoptotic markers, but moderate TUNEL (+) spermatocyte frequency was only found in G. centralis. At subsequent ages, the apoptotic markers were downregulated in testes from parental cytotypes, but not in hybrid testes. TUNEL (+) spermatocytes were present at 78% and 44% per tubule cross-section in 2- and 3-month-old hybrid animals, respectively. Pachytene spermatocyte death in adult hybrids occurs via apoptosis, as revealed by high caspase-3 expression. Calbindin was highly expressed in spermatocytes of adult hybrids, in which massive cell death occurs via apoptosis. Calbindin co-localisation with TUNEL or Fas, Bax and cytochrome c was very limited, suggesting an inverse regulation of calbindin and apoptotic markers. Hybrid sterility is due to breakdown of spermatogenesis at the pachytene spermatocyte stage. Both extrinsic and intrinsic pathways are involved in apoptosis of spermatocytes, which are the most sensitive cell type to apoptotic stimuli.
Asunto(s)
Apoptosis/fisiología , Infertilidad Masculina/veterinaria , Sigmodontinae/crecimiento & desarrollo , Sigmodontinae/fisiología , Espermatocitos/patología , Animales , Calbindinas , Citocromos c/metabolismo , Femenino , Hibridación Genética , Infertilidad Masculina/patología , Infertilidad Masculina/fisiopatología , Masculino , Proteína G de Unión al Calcio S100/metabolismo , Sigmodontinae/genética , Especificidad de la Especie , Testículo/patología , Testosterona/sangre , Proteína X Asociada a bcl-2/metabolismo , Receptor fas/metabolismoRESUMEN
Caltrin is a small and basic protein of the seminal vesicle secretion that inhibits sperm calcium uptake. The influence of rat caltrin on sperm physiological processes related to fertilizing competence was studied by examining its effect on 1) spontaneous acrosomal exocytosis, 2) protein tyrosine phosphorylation, and 3) sperm-egg interaction. Results show that the presence of caltrin during in vitro capacitation both reduced the rate of spontaneous acrosomal exocytosis without altering the pattern of protein tyrosine phosphorylation, and enhanced the sperm ability to bind to the zona pellucida (ZP). The significantly higher proportion of sperm with intact acrosome observed in the presence of caltrin was accompanied by a strong inhibition in the acrosomal hyaluronidase release. Enhancement of sperm-ZP binding was evident by the increase in the percentage of eggs with bound spermatozoa as well as in the number of bound sperm per egg. Similar results were obtained when the assays were performed using spermatozoa preincubated with caltrin and then washed to remove the unbound protein, indicating that the sperm-bound caltrin was the one involved in both acrosomal exocytosis inhibition and sperm-ZP binding enhancement. Caltrin bound to the sperm head was partially released during the acrosomal exocytosis induced by Ca-ionophore A23187. Indirect immunofluorescence and immunoelectron microscopy studies revealed that caltrin molecules distributed on the dorsal sperm surface disappeared after ionophore exposure, whereas those on the ventral region remained in this localization after the treatment. The present data suggest that rat caltrin molecules bound to the sperm head during ejaculation prevent the occurrence of the spontaneous acrosomal exocytosis along the female reproductive tract. Consequently, more competent spermatozoa with intact and functional acrosome would be available in the oviduct to participate in fertilization.
Asunto(s)
Acrosoma/metabolismo , Exocitosis/fisiología , Proteínas de Secreción de la Vesícula Seminal/fisiología , Capacitación Espermática/fisiología , Acrosoma/efectos de los fármacos , Reacción Acrosómica/efectos de los fármacos , Animales , Exocitosis/efectos de los fármacos , Femenino , Masculino , Fosforilación/efectos de los fármacos , Proteínas Tirosina Quinasas/metabolismo , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Proteínas de Secreción de la Vesícula Seminal/farmacología , Capacitación Espermática/efectos de los fármacos , Interacciones Espermatozoide-Óvulo/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Espermatozoides/metabolismo , Zona Pelúcida/metabolismoRESUMEN
The aim of this study was to determine whether the intrinsic mechanism of apoptosis is involved in the death of germ cells in Robertsonian (Rb) heterozygous adult male mice. Testes from 5-month-old Rb heterozygous CD1 x Milano II mice were obtained and compared with those from homozygous CD1 (2n=40) and Milano II (2n=24) mice. For histological evaluation of apoptosis, TUNEL labelling and immunohistochemistry were used to localise Bax and cytochrome c. Expression of calbindin D(28k) (CB), an anti-apoptotic molecule, was also analysed by immunohistochemistry and immunoblotting. Testicular ultrastructure was visualised by electron microscopy. Morphology and cell associations were abnormal in the Rb heterozygous seminiferous epithelium. An intense apoptotic process was observed in tubules at stage XII, mainly in metaphase spermatocytes. Metaphase spermatocytes also showed Bax and cytochrome c redistributions. Mitochondria relocated close to the paranuclear region of spermatocytes. CB was mainly expressed in metaphase spermatocytes, but also in pachytene spermatocytes, spermatids and Sertoli cells at stage XII. The co-localisation of CB and TUNEL labelling was very limited. Sixty per cent of metaphase spermatocytes were apoptotic and calbindin negative, while 40% were calbindin positive without signs of apoptosis. Ten per cent of the Bax- and cytochrome c-positive cells were also calbindin positive. These data suggest that apoptosis of the germ cells in heterozygous mice occurs, at least in part, through a mitochondrial-dependent mechanism. Calbindin overexpression might prevent or reduce the apoptosis of germ cells caused by Rb heterozygosity, which could partially explain the subfertility of these mice.
Asunto(s)
Infertilidad Masculina/patología , Mitocondrias/fisiología , Espermatozoides/ultraestructura , Animales , Apoptosis/fisiología , Biomarcadores/análisis , Calbindinas , Citocromos c/análisis , Heterocigoto , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Masculino , Metafase , Ratones , Ratones Mutantes , Microscopía Electrónica de Transmisión , Modelos Animales , Proteína G de Unión al Calcio S100/análisis , Túbulos Seminíferos/ultraestructura , Células de Sertoli/química , Espermátides/química , Espermátides/ultraestructura , Espermatocitos/química , Espermatocitos/ultraestructura , Testículo/ultraestructura , Proteína X Asociada a bcl-2/análisisRESUMEN
Mouse antral oocytes can be classified in two different types termed SN or NSN oocytes, depending on the presence or absence, respectively, of a ring of Hoechst 33342-positive chromatin surrounding the nucleolus. The aim of the present study was to test the developmental competence to blastocyst of the two types of oocytes. Here we show that following isolation, classification and culture of cumulus-free antral oocytes, 14.7% and 74.5% of NSN and SN oocytes, respectively, reached the metaphase II stage. When fertilised and further cultured none of the metaphase II NSN oocytes developed beyond the 2-cell stage whilst 47.4% of the metaphase II SN oocytes reached the 4-cell stage and 18.4% developed to blastocyst. The findings reported in this paper may contribute to improved procedures of female gamete selection for in vitro fertilisation of humans and farm animals. Furthermore, the selection of oocytes with better developmental potential may be of interest for studies on nuclear/cytoplasm interaction, particularly in nuclear-transfer experiments.
Asunto(s)
Blastocisto/citología , Cromatina/fisiología , Oocitos/citología , Animales , Bencimidazoles , Blastocisto/fisiología , Diferenciación Celular , Nucléolo Celular/fisiología , Técnicas de Cultivo , Femenino , Masculino , Meiosis/fisiología , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BLRESUMEN
The imprinted mouse Xist (X-inactive specific transcript) gene is involved in the initiation of X-chromosome inactivation. Only the paternal Xist is expressed in preimplantation development beginning from the 4-cell stage, preceding and in correlation with paternal X-inactivation in the extraembryonic lineage of the blastocyst. To better understand the mechanisms regulating Xist expression in early development, we investigated the precise timing of its onset. We set up a single-cell RT-PCR for the simultaneous analysis on single embryos of Xist and Hprt (internal control) cDNAs and a Y-chromosome specific DNA sequence, Zfy (for embryo sexing). Applying this procedure, we demonstrate that Xist expression begins at the G2-phase of 2-cell female embryos, earlier than previously reported and at the same time of the major wave of zygotic genome activation (ZGA). We then examined, if Xist expression at the 2-cell stage is dependent on the lapse of time spent since fertilization, as previously reported for zygotic genes. One-cell embryos at the G2-phase of the first cell-cycle were cultured with cytochalasin D (inhibitor of cytokinesis but not of DNA synthesis or nuclear progression) for a time equivalent to the 4-cell stage in control, untreated embryos. We show that Xist activation occurs at a scheduled time following fertilization despite the embryos being blocked at the 1-cell stage, suggesting the existence of a zygotic clock involved in the regulation of the transcription of this imprinted gene.
Asunto(s)
Relojes Biológicos/fisiología , Fertilización/fisiología , Regulación del Desarrollo de la Expresión Génica , Genoma , ARN no Traducido/genética , Factores de Transcripción/genética , Cigoto/metabolismo , Animales , Citocalasina D/farmacología , Embrión de Mamíferos/efectos de los fármacos , Embrión de Mamíferos/metabolismo , Fertilización/genética , Fertilización In Vitro , Fase G2 , Hipoxantina Fosforribosiltransferasa/metabolismo , Ratones , Partenogénesis/genética , ARN Largo no Codificante , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo , Cromosoma X/genética , Cigoto/efectos de los fármacosRESUMEN
Estudio descriptivo, transversal cuyo propósito es conocer la actitud frente a la persona VIH/SIDA de los trabajadores de la salud. El universo corresponde a 496 trabajadores profesionales y no profesionales pertenecientes a la corporación municipal de La Florida (COMUDEF), la muestra es de tipo intencionada y queda constituida por 58 trabajadores de la salud. Para obtener la información se revalida y aplica una escala de actitudes construida por Stewart, V & Castellano, A (2001), basada en una escala de actitudes de Castellano, A (1993), validada con un índice de alpha de Cronbach de 0,68; en el presente estudio se obtuvo un alpha de Cronbach de 0,738, lo que reafirma la valicez del instrumento. Los resultados obtenidos muestran una actitud indiferente hacia las personas VIH/SIDA, a pesar de estos resultados se observa que los profesionales tienen sentimientos más positivos hacia estas que los no profesionales, lo que han realizado atención a estas personas tienen una actitud indiferente (22,8 porciento) y positiva (21,1 porciento) obteniendo una diferencia significativa en relación a lo que no han atendido.Los que han realizado atención directa a personas VIH/SIDA tienen uan actitud positiva (22,8 porciento), los que no han realizado atención directa tienen una actitud indiferente (35,1 porciento) y negativa (14 porciento), obteniendo también una diferencia significativa, lo que plantea un gran desafío para enfermería en relación a la educación para lograr un cambio de actitud, llegando de esta manera a una atención humanizada para las personas VIH/SIDA
Asunto(s)
Humanos , Síndrome de Inmunodeficiencia Adquirida , Actitud del Personal de Salud , Actitud Frente a la Salud , Atención al Paciente , Calidad de la Atención de Salud , Atención de EnfermeríaRESUMEN
Se realizó un estudio multicéntrico abierto no comparaivo en el que participaron 18 reconocidos urólogos de la República Mexicana, de las ciudades de Monterey, Guadalajara, Toluca, León y el Distrito Federal. Se valoró la eficacia antimicrobiana y la tolerancia de pefloxacina en dosis única de dos comprimidos de 400 mg. en el tatamiento de uretrocistitits infecciosa, previa revisión del protocolo de investigación clínica por parte de los investigadores participantes con la finalidad de unificar criterior para su valoración posterior