Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
J Mater Chem B ; 5(6): 1284-1292, 2017 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-32263596

RESUMEN

We report the synthesis of a new multifunctional colloidal hybrid system consisting of thermoresponsive amphiphilic biocompatible poly(N-vinylcaprolactam) microgels loaded with hydrophobic superparamagnetic FePt nanoparticles (NPs). In the first step, water swellable poly(N-vinylcaprolactam) microgels were mixed with hydrophobically coated sub-10 nm superparamagnetic FePt NPs in a tetrahydrofuran (THF) solution. In the second step, changing the surrounding solvent from THF to water forces the FePt NPs to migrate into the amphiphilic microgels. These new hybrid microgels (i) are colloidally stable in water and their thermo-responsive properties in terms of volume phase transition are retained, (ii) exhibit superparamagnetic characteristics introduced by FePt NPs, (iii) show a drastically reduced cytotoxicity compared to water-soluble FePt NPs of similar size, as known from the literature. This makes the new hybrid microgels suitable e.g. as biocompatible containers for drug delivery or for imaging.

2.
J Am Diet Assoc ; 101(7): 780-5, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11478475

RESUMEN

Despite universal acceptance of the importance of whole grains in the diet, consumer knowledge of the benefits of whole grains and intake of these foods are low. This review summarizes the research supporting whole-grain consumption and gives practical suggestions about how to increase whole-grain intake. Whole-grain foods are valuable sources of nutrients that are lacking in the American diet, including dietary fiber, B vitamins, vitamin E, selenium, zinc, copper, and magnesium. Whole-grain foods also contain phytochemicals, such as phenolic compounds, that together with vitamins and minerals play important roles in disease prevention. The exact mechanisms linking whole grains to disease prevention are not known but may include gastrointestinal effects, antioxidant; protection, and intake of phytoestrogens. Dietary intake studies indicate that consumption of whole grains is far less than the recommended intake of 3 servings a day, with an average daily intake of 1 or fewer servings a day. A new whole-grains health claim, allowed in July 1999 by the Food and Drug Administration, and inclusion of a whole-grain recommendation in the 2000 revision of the US Dietary Guidelines for Americans, should help increase whole-grain consumption.


Asunto(s)
Enfermedad Coronaria/prevención & control , Grano Comestible , Promoción de la Salud , Neoplasias/prevención & control , Glucemia , Enfermedad Coronaria/dietoterapia , Guías como Asunto , Conocimientos, Actitudes y Práctica en Salud , Humanos , Neoplasias/dietoterapia , Política Nutricional , Encuestas Nutricionales , Estados Unidos
3.
Am J Obstet Gynecol ; 179(2): 299-307, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9731830

RESUMEN

OBJECTIVE: The aim of this study was to investigate various outcome measures of stimulation with highly purified subcutaneous follicle-stimulating hormone (Fertinex, a urofollitropin) compared with first- and second-generation urinary human menopausal gonadotropin standards (Pergonal, Metrodin). STUDY DESIGN: Retrospective analysis was restricted to our most efficient in vitro fertilization age group (23-34 years). Data from Institute for Assisted Reproduction in vitro fertilization cycles 1 through 11 with Pergonal, Metrodin, or both were tabulated for hormonal values, oocyte quality, and embryo outcome as baseline data. Patients in cycles 12 through 13 were treated with Fertinex and Pergonal or Fertinex alone and then reviewed for the same parameters. RESULTS: Two hundred thirty-eight in vitro fertilization records with embryo transfer were analyzed. Clinical pregnancy rates per embryo transfer in an optimal age group were similar despite use of first- through third-generation urinary gonadotropin preparations: Pergonal and Metrodin, 67%; Metrodin, 64%; Fertinex and Pergonal, 62%; and Fertinex, 54%. There were no discernible differences in hormonal response, oocyte recovery, or embryonic growth. CONCLUSION: Administered subcutaneously, the third-generation urinary gonadotropin preparation Fertinex is effective in in vitro fertilization treatment in young women.


Asunto(s)
Fertilización In Vitro , Hormona Folículo Estimulante/administración & dosificación , Menotropinas/administración & dosificación , Adulto , Femenino , Humanos , Inyecciones Intramusculares , Inyecciones Subcutáneas , Masculino , Embarazo , Estudios Retrospectivos
4.
Hum Reprod ; 13 Suppl 4: 166-72, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10091067

RESUMEN

The variability in pregnancy rates achieved among in-vitro fertilization (IVF) clinics may be partially attributable to the disparate quality of the water used in the preparation of culture media. The removal of contaminants in the water is of paramount importance since water constitutes the predominant component in any media formulation. To assist in the selection, operation and maintenance of a water purification system, the level of contaminants must be carefully monitored. Conductivity and resistance are used to measure the purity of natural and ultrapure water respectively. Feed water is analysed by an assortment of direct chemical means to determine the necessary system filtration steps. In general, high quality water can be produced by combined reverse osmosis and electrodeionization of treated tap water. Processed water is supplied to an ultrapure water system to provide final polished water. A detailed water processing protocol is presented along with quality assurance guidelines to ensure the consistent production of high quality ultrapure water suitable for in-vitro human embryo culture.


Asunto(s)
Medios de Cultivo , Fertilización In Vitro , Contaminación del Agua , Animales , Medios de Cultivo/normas , Filtración , Guías como Asunto , Humanos , Purificación del Agua/métodos
5.
Hum Reprod ; 13 Suppl 4: 226-38, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10091073

RESUMEN

Co-culture techniques using fetal bovine uterine fibroblasts or bovine oviductal epithelial cells have improved embryonic development prior to replacement in humans. In initial co-culture trials, embryo development and implantation rates increased after just 1 day in culture. The most overt characteristics noted following co-culture were improved blastomere development and characteristics, reduced fragmentation, and the appearance of swollen blastomeres. In addition, an increase in the incidence of zona thickness variation was detected. Improved development of polyspermic and supernumerary embryos to the blastocyst stage was noted in initial trials. Retrospective analysis indicated that certain patient subgroups benefit the most from co-culture. As a result, co-culture is now applied routinely to patients that have previously failed attempts at in-vitro fertilization (IVF) and/or have endocrine imbalances such as polycystic ovarian syndrome and elevated day 3 concentrations of follicle stimulating hormone (FSH). The use of co-culture prior to or following cryopreservation has also proven to be beneficial to human embryos. The proposed beneficial mechanisms thought to improve embryonic development include a secretory and/or a scavenging role. Evidence describing the postulated benefits is discussed.


Asunto(s)
Técnicas de Cocultivo , Embrión de Mamíferos , Técnicas Reproductivas , Criopreservación , Embrión de Mamíferos/fisiología , Desarrollo Embrionario y Fetal/fisiología , Humanos
7.
Hum Reprod ; 11(11): 2429-33, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8981126

RESUMEN

A study was conducted on patients who had attempted and failed previous in-vitro fertilization (IVF) procedures an average of 3.8 times following the application of assisted hatching with conventional culture systems. The aim of this investigation was to determine if addition of co-culture methodologies could reduce embryonic abnormalities and thus improve the prognosis for pregnancy. The study population consisted of 123 patients, subdivided into three patient categories. Previous IVF results from conventional culture were used to evaluate any potential benefits derived from the present co-culture application. Following co-culture, the rate of blastomere development was increased and the rate of fragmentation decreased. An increased rate of blastomere development was most noticeable in the patients aged < or = 39 years with no male factor as well as the intracytoplasmic sperm injection (ICSI) subgroup. Similarly, the rate of fragmentation was significantly reduced in the aforementioned subgroups. The most pronounced impact of co-culture was on pregnancy and implantation rates. The overall clinical and ongoing pregnancy rates were 38% (47/123) and 36% (44/123) respectively. The corresponding implantation rate was 17% (72/ 412) as shown by embryonic cardiac activity. The ongoing pregnancy rates in the < or = 39 years no male factor, > or = 40 years no male factor and ICSI no age limit patient subgroups were 41% (21/51), 30% (8/27) and 33% (15/45) respectively. The results indicate that addition of co-culture to the IVF procedure for poor-prognosis patients may be advisable.


Asunto(s)
Técnicas de Cocultivo , Fertilización In Vitro , Adulto , Animales , Blastómeros/fisiología , Bovinos , Citoplasma , Implantación del Embrión , Trompas Uterinas , Femenino , Fertilización In Vitro/métodos , Humanos , Infertilidad/terapia , Masculino , Microinyecciones , Embarazo
8.
Z Gastroenterol ; 34(8): 483-9, 1996 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-8967121

RESUMEN

Esophageal and anorectal motility have not been systematically evaluated in patients with sphincter of Oddi dysfunction (SOD). We have investigated 8 consecutive patients (6 females, 52.5 +/- 9.5 y) with type I-SOD (according to the Milwaukee-classification), 12 patients (9 females, 50.4 +/- 12.3 y) with type III-SOD, and 20 healthy volunteers (15 females, 48.5 +/- 15.2 y) by means of a standardized questionnaire for esophageal and anorectal symptoms, esophageal manometry, colonic transit time evaluation, and anorectal manometry. Symptom-scores did not differ significantly between type-I and type III-SOD-patients, respectively. Furthermore, there were no relevant differences of the symptom-scores of the SOD-patients vs. healthy subjects. However, the lower esophageal sphincter pressure (LESP) was significantly higher in patients with type I-SOD (26.8 +/- 7.4 mmHg) than in both, type III-SOD-patients (20.3 +/- 4.0 mmHg, p < 0.05) and healthy subjects (18.6 +/- 3.5 mmHg, p < 0.001), respectively. Mean colonic transit time did not differ significantly between both groups of patients (type I-SOD, 27.9 +/- 21.4 h, vs. type III-SOD, 28.5 +/- 15.1 h, p < 0.05). The anal sphincter resting pressure (ARP) was significantly higher in patients with type I-SOD (90.8 +/- 15.5 mmHg) than in healthy subjects (74.1 +/- 10.3, p < 0.01), but did not differ significantly from that in patients with type III-SOD (82.1 +/- 11.5 mmHg, p = 0.17). Computer-assisted "beat-to-beat"-evaluation showed an abnormal heart rate variability in 3/8 patients with type I-SOD. These results give evidence for a systemic involvement of the lower esophageal and the anal sphincter in patients with type I-SOD, which does not occur in patients with type III-SOD.


Asunto(s)
Enfermedades del Conducto Colédoco/fisiopatología , Trastornos de la Motilidad Esofágica/fisiopatología , Motilidad Gastrointestinal/fisiología , Esfínter de la Ampolla Hepatopancreática/fisiopatología , Adulto , Anciano , Enfermedades del Sistema Nervioso Autónomo/diagnóstico , Enfermedades del Sistema Nervioso Autónomo/fisiopatología , Colangiopancreatografia Retrógrada Endoscópica , Colon/fisiopatología , Enfermedades del Conducto Colédoco/diagnóstico , Trastornos de la Motilidad Esofágica/diagnóstico , Unión Esofagogástrica/fisiopatología , Esófago/fisiopatología , Femenino , Tránsito Gastrointestinal/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Manometría , Persona de Mediana Edad , Recto/fisiopatología
9.
Eur J Gastroenterol Hepatol ; 8(3): 251-6, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8724026

RESUMEN

OBJECTIVES: To assess the incidence of elevated sphincter of Oddi baseline pressure and the response to endoscopic sphincterotomy in patients with suspected sphincter of Oddi dysfunction. DESIGN: A 5-year prospective clinical trial. METHODS: One-hundred and eight patients with recurrent biliary-type pain after cholecystectomy were enrolled. After thorough investigation, 35 patients with suspected type II sphincter of Oddi dysfunction (SOD) and another 29 type III patients remained for further investigation. Both groups were similar with respect to demographic data and severity of pain. Biliary manometry was performed in all except three patients in either group. Endoscopic sphincterotomy was performed in all patients with abnormal sphincter of Oddi baseline pressure (> 40 mmHg). All patients were clinically re-evaluated after 4-6 weeks, and thereafter the sphincterotomized patients were followed for a median period of 2.5 years. RESULTS: An abnormal sphincter of Oddi baseline pressure was found in 62.5% of the type II patients and in 50% of the patients with suspected type III SOD (P = 0.66). At the 4-6 week follow-up none of those patients without abnormal manometry, but 70% of the patients with type II SOD, and 39% of the type III SOD patients, respectively, reported subjective benefit after sphincterotomy (P = 0.13 type II vs. type III). However, after a median follow-up of 2.5 years, sustained symptomatic improvement after sphincterotomy was found in 60% of the type II patients, but only in 8% of the patients with type III SOD (P < 0.01). CONCLUSION: Disregarding a lack of difference in the incidence of abnormal sphincter of Oddi baseline pressure between type II and type III SOD, the Geenen-Hogan classification helps to predict the clinical outcome after endoscopic sphincterotomy.


Asunto(s)
Esfínter de la Ampolla Hepatopancreática/fisiopatología , Esfinterotomía Endoscópica , Colecistectomía , Enfermedades del Conducto Colédoco/clasificación , Enfermedades del Conducto Colédoco/fisiopatología , Enfermedades del Conducto Colédoco/terapia , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Manometría , Persona de Mediana Edad , Dolor , Presión , Estudios Prospectivos , Recurrencia , Resultado del Tratamiento
10.
Hum Reprod ; 10(12): 3226-32, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8822449

RESUMEN

A retrospective study was undertaken to determine if initial culture conditions and embryo quality had an effect on subsequent blastocyst development in co-culture for cryopreservation. The apparent effects of freeze-thawing on blastocysts at the ultrastructure level were also observed. On day 3 of culture, embryos were categorized into two groups based on their morphological attributes. Results suggest that the initial culture environment of embryos up to day 3 (5- to 8-cell stage) did not affect the subsequent rate of blastocyst formation in co-culture. However, the initial embryo quality had an impact on blastocyst formation and quality. On day 5.5, 90% (60/67) of the optimal quality embryos (six to eight blastomeres with minimal or no fragmentation on day 3) had attained the blastocyst stage, which was greater (P < 0.01) than the 55% (31/56) observed with the sub-optimal embryos (five to eight blastomeres with 30-50% fragmentation on day 3). Furthermore, 66% (44/67) of embryos initially graded as optimal were suitable for cryopreservation, which was greater (P < 0.01) than attained with embryos of lesser quality (22/56; 39%). At the ultrastructural level, the polarized distribution of plasma membrane microvilli was retained, as was the integrity of the nuclear membrane following thawing.


Asunto(s)
Blastocisto/ultraestructura , Desarrollo Embrionario y Fetal , Criopreservación , Técnicas de Cultivo , Femenino , Fertilización In Vitro , Humanos , Masculino , Microscopía Electrónica , Estudios Retrospectivos , Factores de Tiempo
11.
Z Gastroenterol ; 33(11): 662-8, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8600663

RESUMEN

Patients with fibrotic papillary stenosis (PS) are at high risk for sphincter of Oddi-re-stenosis after endoscopic sphincterotomy (ES). Therefore, a prospective trial was conducted to assess the acute and long-term effects of ES on sphincter of Oddi motor function in patients with papillary stenosis. The immediate effects of ES were studies by endoscopic manometry in 12 patients with PS, and in 15 patients with common bile duct stones (CBDS, control group). Furthermore, after a median follow-up of 15 months, 11 from those 12 patients with papillary stenosis were reinvestigated with ERCP and manometry. Complete ES (defined by a common bile duct pressure and a basal sphincter of Oddi-pressure (BSOP) < 5 mm Hg) was achieved in 13/15 CBDS-patients, but only in 3/12 patients with PS (p<0.01), although sphincterotomy was extended to the maximal length as judged endoscopically. Four patients with PS had a residual BSOP > 20 mm Hg. However, all patients with PS became symptom-free immediately after ES. The phasic sphincter motility was not affected significantly different in both groups of patients (p = 0.25). Those patients with a residual BSOP > 20 mm Hg after ES developed sphincter of Oddi-re-stenosis during the follow-up (3 patients) or revealed re-stenosis at the control examination after follow-up (1 patient). After the follow-up manometrically defined complete sphincterotomy was furtheron demonstrable in only 2/11 patients with papillary stenosis. In conclusion, ES revealed a decreased efficacy to eliminate the sphincter of Oddi motor function in a substantial number of patients with papillary stenosis. This may explain the remarkably high rate of sphincter of Oddi-re-stenosis after sphincterotomy in these patients.


Asunto(s)
Colestasis Extrahepática/terapia , Cálculos Biliares/terapia , Manometría , Complicaciones Posoperatorias/fisiopatología , Esfínter de la Ampolla Hepatopancreática/fisiopatología , Esfinterotomía Endoscópica , Adulto , Anciano , Colangiopancreatografia Retrógrada Endoscópica , Colestasis Extrahepática/fisiopatología , Femenino , Estudios de Seguimiento , Cálculos Biliares/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Recurrencia
12.
Hum Reprod ; 10(9): 2371-6, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8530668

RESUMEN

Videocinematography and image analysis procedures were utilized to evaluate the effect of conventional and coculture methodologies on morphological parameters in human embryos derived from in-vitro fertilization (IVF). Following 24-30 h of in-vitro development, cocultured embryos had more acceptable morphological features and less fragmentation present than embryos cultured in medium alone. Cocultured embryos were more advanced at the time of replacement when compared with conventionally cultured embryos. Zona pellucida variation (> or = 20%) also occurred more frequently in cocultured embryos. The morphological characteristic most enhanced after coculture was blastomere expansion. Patients who became pregnant across both culture treatments had a higher proportion of morphologically normal embryos replaced than patients who failed to achieve an ongoing pregnancy. Clinical pregnancy rate for patients following coculture was 49%, which was greater (P < 0.05) than the 29% detected for patients with embryos in the conventional culture group.


Asunto(s)
Embrión de Mamíferos/anatomía & histología , Fertilización In Vitro , Grabación de Cinta de Video , Animales , Blastómeros/fisiología , Bovinos , Técnicas de Cocultivo , Técnicas de Cultivo , Transferencia de Embrión , Embrión de Mamíferos/fisiología , Trompas Uterinas/fisiología , Femenino , Humanos , Embarazo , Resultado del Embarazo , Zona Pelúcida/fisiología
13.
Hum Reprod ; 9(8): 1528-31, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7989518

RESUMEN

Older patients and those who consistently return for embryo transfer but without implantation were studied to see if a combination of day 3 assisted hatching and co-culture (AH+CC) might be beneficial compared to assisted hatching alone (AH-alone). Female patients of > or = 38 years and couples who had previously failed to implant embryos three times or more were prospectively and randomly assigned to either an experimental or a control group. In the experimental group all embryos were co-cultured on partial monolayers of bovine oviductal epithelial cells for 2 days followed by assisted hatching by zona drilling (AH+CC). All control embryos were cultured by standard procedures until day 3 when they also underwent zona drilling prior to uterine transfer (AH-alone). With 50 cycles in each group there was unfortunately a marginal bias against the AH+CC group in that these patients had undergone a higher number of previous transfer cycles. There was a marginally lower percentage of fragmentation and a significantly higher degree of zona thickness variability in the AH+CC embryo group. Embryonic implantation was significantly increased (P < 0.05) in the AH+CC group (18%) when compared to the AH-alone group (10%). This difference was reflected in a significantly higher (P < 0.05) initial pregnancy rate (52 versus 32%) in the AH+CC group, and a higher (not significant) viable pregnancy rate (38 versus 22%).


Asunto(s)
Transferencia de Embrión , Trompas Uterinas/fisiología , Fertilización In Vitro , Adulto , Animales , Bovinos , Medios de Cultivo Condicionados , Técnicas de Cultivo , Implantación del Embrión , Epitelio/fisiología , Femenino , Humanos , Embarazo , Resultado del Embarazo , Pronóstico , Estudios Prospectivos
14.
Fertil Steril ; 61(1): 105-10, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8293823

RESUMEN

OBJECTIVE: To establish pregnancies using a combination of coculture and selective assisted hatching. DESIGN: Clinical application for a selected group of patients. Not a controlled study. SETTING: Private infertility practice. PATIENTS: Women with high basal FSH levels, ovulatory disorders, and multiple failed IVF attempts. MAIN OUTCOME MEASURES: Pregnancy and implantation rates. RESULTS: Of the 95 patients who had coculture and selective assisted hatching, 45 (47.0%) have an ongoing pregnancy with a 23.0% implantation rate. CONCLUSION: The combination of coculture and assisted hatching produced acceptable pregnancy and implantation rates within the selected patient population.


Asunto(s)
Fertilización In Vitro/métodos , Adulto , Animales , Blastocisto , Bovinos , Células Cultivadas , Implantación del Embrión , Femenino , Humanos , Micromanipulación , Embarazo , Zona Pelúcida
15.
Hum Reprod ; 8(1): 97-101, 1993 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8458937

RESUMEN

A study was undertaken to evaluate embryonic development and establish pregnancies with human embryos after in-vitro culture in two different systems. Treatment A consisted of culturing zygotes in serum-supplemented human tubal fluid culture medium (HTF). Treatment B consisted of culturing zygotes on a monolayer of bovine oviductal epithelial cells with HTF. At the time of embryo replacement, embryos in treatment B had 4.11 blastomeres present, which was greater (P < 0.05) than the 3.81 present for embryos in treatment A. In addition, the cellular fragmentation rate for treatment A embryos was 1.10, which was greater (P < 0.05) than the fragmentation rate of 0.38 for embryos within treatment B. The incidence of ongoing pregnancy was higher after replacement of co-cultured embryos (treatment B) (43%) than replacement of conventionally cultured embryos (treatment A) (29%). The implantation rate per embryo increased (P < 0.05) from 11.5 to 18.4% after co-culture. In treatment B the proportion of 'spare' embryos developing to expanded blastocysts was 58.5%, which was greater (P < 0.05) than the blastocyst development rate of 29.3% observed for embryos within treatment A.


Asunto(s)
Implantación del Embrión/fisiología , Embrión de Mamíferos/fisiología , Trompas Uterinas/citología , Cigoto/fisiología , Animales , Bovinos , Células Cultivadas , Desarrollo Embrionario y Fetal/fisiología , Células Epiteliales , Femenino , Humanos , Masculino
17.
Mol Reprod Dev ; 31(4): 231-40, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1571156

RESUMEN

This study describes the localization of the U2 small nuclear RNA (snRNA) and the major U snRNA group ribonucleoproteins (snRNPs) during bovine preimplantation development. In vitro maturation, fertilization, and oviductal epithelial cell coculture methods were employed to produce several developmental series totalling over 2,000 preimplantation-stage bovine oocytes and embryos. These oocytes and preimplantation embryos were processed for in situ hybridization, immunofluorescence and Northern blotting methods. The U2 snRNA and the major U group snRNPS were localized initially over the germinal vesicle (GV) of preovulatory oocytes but following GV breakdown were released throughout the ooplasm. They subsequently reassociated with both pronuclei during fertilization. From the two-cell to the blastocyst stages, the U2 snRNA and U snRNPs were localized to the interphase nucleus of each blastomere. The levels of U2 snRNA throughout bovine preimplantation development were determined by probing a Northern blot containing total RNA isolated from the following preimplantation bovine embryo stages: one to two cell, eight to 16 cell, early morula (greater than 32 cell), and late morula/early blastocysts. The levels of U2 snRNA remained constant between the one-cell and eight- to 16-cell bovine embryo stages but increased 4.4-fold between the eight- to 16-cell stage and the late morula/early blastocyst stages. The results suggest that a maternal pool of snRNAs is maintained in mammalian preimplantation embryos regardless of the duration of maternal control of development.


Asunto(s)
Desarrollo Embrionario/genética , Desarrollo Embrionario y Fetal/genética , ARN Nuclear Pequeño/biosíntesis , Animales , Northern Blotting , Bovinos , Técnicas de Cultivo , Femenino , Técnica del Anticuerpo Fluorescente , Expresión Génica , Ratones , Hibridación de Ácido Nucleico , Embarazo , ARN Nuclear Pequeño/genética
18.
Mol Reprod Dev ; 31(2): 87-95, 1992 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1318055

RESUMEN

The sensitive technique of mRNA phenotyping with the reverse transcription-polymerase chain reaction was employed to determine the patterns of gene expression for several growth factor ligand and receptor genes during bovine preimplantation development. Several thousand bovine embryos encompassing a developmental series from one-cell zygotes to hatched blastocysts were produced by the application of in vitro maturation, fertilization, and oviductal epithelial cell embryo coculture methods. Transcripts for transforming growth factor (TGF-alpha) and platelet-derived growth factor (PDGF-A) are detectable in all preimplantation bovine stages as observed in the mouse. Transcripts for TGF-beta 2 and insulin-like growth factor (IGF-II) and the receptors for PDGF-alpha, insulin, IGF-I, and IGF-II are also detectable throughout bovine preimplantation development, suggesting that these mRNAs are products of both the maternal and the embryonic genomes in the cow, whereas in the mouse they are present only following the activation of the embryonic genome at the two-cell stage. In contrast to the mouse embryo, IGF-I mRNA was detected within preimplantation bovine embryos. Basic fibroblast growth factor (bFGF) is a maternal message in the bovine embryo, since it is only detectable up until the eight-cell embryo stage. Bovine trophoblast protein (bTP) mRNA was detectable within day 8 bovine blastocysts. As was observed in the mouse, the transcripts for insulin, epidermal growth factor (EGF), or nerve growth factor (NGF) were not detectable in any bovine embryo stage. Analyses of this type should aid the development of a completely defined culture medium for the more efficient production of preimplantation bovine embryos.


Asunto(s)
Blastocisto/metabolismo , Sustancias de Crecimiento/genética , Receptores de Superficie Celular/genética , Animales , Secuencia de Bases , Bovinos , Técnicas de Cultivo , ADN , Expresión Génica , Ligandos , Datos de Secuencia Molecular , Oviductos/citología , Oviductos/metabolismo , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo
19.
Mol Reprod Dev ; 30(4): 330-8, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1751037

RESUMEN

A total of 901 cumulus-oocyte complexes (COCs) were collected from bovine ovaries obtained at a local abattoir. COCs randomly assigned to Treatment I (n = 451), were cultured in TCM-199 + 10% fetal bovine serum (FBS) and hormones, while oocytes in Treatment II (n = 450) were cultured in TCM-199 + 20% estrous cow serum (ECS). Assessment of maturation revealed that 91.3% (42/46) of oocytes in Treatment I had reached metaphase II of meiosis, which was greater (P less than 0.05) than the 73.3% (33/45) in Treatment II. Following in vitro fertilization, 203 oocytes from Treatment I were co-cultured on bovine granulosa cells (Treatment IA) while the remaining 202 oocytes were co-cultured on bovine oviductal cells (Treatment IB). Similarly, 203 oocytes from Treatment II were co-cultured on granulosa cells (Treatment IIA) or oviductal cells (Treatment IIB, n = 202). Co-culture was maintained for 8 days. The proportion of cleaved zygotes was higher (P less than 0.05) in Treatment IB (86.6%) compared to Treatments IA (78.8%), IIA (58.1%), and IIB (64.8%). The proportion of cleaved zygotes that progressed beyond the 16-cell stage was also greater (P less than 0.001) in Treatment IB (71.4%) compared to Treatments IA (50.0%), IIA (35.4%) and IIB (55.8%). Treatment IB also produced the highest proportion of blastocysts (P less than 0.0001) (41.1%) versus 24.6% (IA), 11.3% (IIA) and 18.3% (IIB). The proportion of day 6 morulae that progressed to form day 8 blastocysts was similar for both co-culture treatments (IA, 70.1%; IB 70.2%; IIA, 51.5%; IIB 50.8%) and varied only between in vitro maturation groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Técnicas de Cultivo/métodos , Desarrollo Embrionario y Fetal , Animales , Bovinos , División Celular , Separación Celular , Células Cultivadas , Transferencia de Embrión , Trompas Uterinas/citología , Femenino , Fertilización In Vitro , Gonadotropinas , Células de la Granulosa/citología , Oocitos/citología , Esteroides , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...