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1.
Nature ; 480(7376): 215-8, 2011 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-22158244

RESUMO

Observational work conducted over the past few decades indicates that all massive galaxies have supermassive black holes at their centres. Although the luminosities and brightness fluctuations of quasars in the early Universe suggest that some were powered by black holes with masses greater than 10 billion solar masses, the remnants of these objects have not been found in the nearby Universe. The giant elliptical galaxy Messier 87 hosts the hitherto most massive known black hole, which has a mass of 6.3 billion solar masses. Here we report that NGC 3842, the brightest galaxy in a cluster at a distance from Earth of 98 megaparsecs, has a central black hole with a mass of 9.7 billion solar masses, and that a black hole of comparable or greater mass is present in NGC 4889, the brightest galaxy in the Coma cluster (at a distance of 103 megaparsecs). These two black holes are significantly more massive than predicted by linearly extrapolating the widely used correlations between black-hole mass and the stellar velocity dispersion or bulge luminosity of the host galaxy. Although these correlations remain useful for predicting black-hole masses in less massive elliptical galaxies, our measurements suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes.

2.
Proc Natl Acad Sci U S A ; 111(35): 12661-6, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-24821792

RESUMO

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 10(6) at 0.75 arcseconds and 10(5) at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of [Formula: see text] near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017.

3.
Nature ; 435(7045): 1067-70, 2005 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-15973402

RESUMO

The Sun and >15 per cent of nearby stars are surrounded by dusty disks that must be collisionally replenished by asteroids and comets, as the dust would otherwise be depleted on timescales <10(7) years (ref. 1). Theoretical studies show that the structure of a dusty disk can be modified by the gravitational influence of planets, but the observational evidence is incomplete, at least in part because maps of the thermal infrared emission from the disks have low linear resolution (35 au in the best case). Optical images provide higher resolution, but the closest examples (AU Mic and beta Pic) are edge-on, preventing the direct measurement of the azimuthal and radial disk structure that is required for fitting theoretical models of planetary perturbations. Here we report the detection of optical light reflected from the dust grains orbiting Fomalhaut (HD 216956). The system is inclined 24 degrees away from edge-on, enabling the measurement of disk structure around its entire circumference, at a linear resolution of 0.5 au. The dust is distributed in a belt 25 au wide, with a very sharp inner edge at a radial distance of 133 au, and we measure an offset of 15 au between the belt's geometric centre and Fomalhaut. Taken together, the sharp inner edge and offset demonstrate the presence of planetary-mass objects orbiting Fomalhaut.

4.
Proteomics ; 9(6): 1469-87, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19294625

RESUMO

Protein phosphorylation is a primary form of information transfer in cell signaling pathways and plays a crucial role in regulating biological responses. Aberrant phosphorylation has been implicated in a number of diseases, and kinases and phosphatases, the cellular enzymes that control dynamic phosphorylation events, present attractive therapeutic targets. However, the innate complexity of signaling networks has presented many challenges to therapeutic target selection and successful drug development. Approaches in phosphoproteomics can contribute functional, systems-level datasets across signaling networks that can provide insight into suitable drug targets, more broadly profile compound activities, and identify key biomarkers to assess clinical outcomes. Advances in MS-based phosphoproteomics efforts now provide the ability to quantitate phosphorylation with throughput and sensitivity to sample a significant portion of the phosphoproteome in clinically relevant systems. This review will discuss recent work and examples of application data that demonstrate the utility of MS, with a particular focus on the use of quantitative phosphoproteomics and phosphotyrosine-directed signaling analyses to provide robust measurement for functional biological interpretation of drug action on signaling and phenotypic outcomes.


Assuntos
Descoberta de Drogas , Espectrometria de Massas , Fosfoproteínas/análise , Proteômica/métodos , Transdução de Sinais , Animais , Linhagem Celular , Humanos
5.
J Biomol Screen ; 13(7): 626-37, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18626117

RESUMO

Cellular homeostasis and responses to stimuli are mediated by complex signaling network events dominated by changes in protein phosphorylation states. Understanding information flow in the network is essential for correlating signaling changes to cell physiology. Tyrosine phosphorylation constitutes only a small portion of all protein phosphorylation, but its importance is manifested by the significant role it plays in diseases such as cancer. A peptide-based immunoassay microarray, designed to provide site specificity, quantification, broad coverage, and accessibility, is described that profiles 45 tyrosine phosphorylation sites across 34 proteins. Epidermal growth factor-stimulated A431 cells in the absence and presence of kinase inhibitors analyzed by microarrays showed biologically validated tyrosine phosphorylation changes and unanticipated activation of other targets. The approach is scalable for increasing the breadth of content as well as for interrogating other types of protein posttranslational modifications.


Assuntos
Imunoensaio/métodos , Peptídeos/química , Tirosina/química , Anticorpos/química , Linhagem Celular , Linhagem Celular Tumoral , Epitopos/química , Humanos , Células Jurkat , Modelos Biológicos , Fosforilação , Proteômica/métodos , Padrões de Referência , Transdução de Sinais , Células U937
6.
Fertil Steril ; 105(2): 459-66.e2, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26604065

RESUMO

OBJECTIVE: To evaluate a single treatment center's experience with autologous IVF using vitrified and warmed oocytes, including fertilization, embryonic development, pregnancy, and birth outcomes, and to estimate the likelihood of live birth of at least one, two, or three children according to the number of mature oocytes cryopreserved by elective fertility preservation patients. DESIGN: Retrospective cohort study. SETTING: Private practice clinic. PATIENT(S): Women undergoing autologous IVF treatment using vitrified and warmed oocytes. Indications for oocyte vitrification included elective fertility preservation, desire to limit the number of oocytes inseminated and embryos created, and lack of available sperm on the day of oocyte retrieval. INTERVENTION(S): Oocyte vitrification, warming, and subsequent IVF treatment. MAIN OUTCOME MEASURE(S): Post-warming survival, fertilization, implantation, clinical pregnancy, and live birth rates. RESULT(S): A total of 1,283 vitrified oocytes were warmed for 128 autologous IVF treatment cycles. Postthaw survival, fertilization, implantation, and birth rates were all comparable for the different oocyte cryopreservation indications; fertilization rates were also comparable to fresh autologous intracytoplasmic sperm injection cycles (70% vs. 72%). Implantation rates per embryo transferred (43% vs. 35%) and clinical pregnancy rates per transfer (57% vs. 44%) were significantly higher with vitrified-warmed compared with fresh oocytes. However, there was no statistically significant difference in live birth/ongoing pregnancy (39% vs. 35%). The overall vitrified-warmed oocyte to live born child efficiency was 6.4%. CONCLUSION(S): Treatment outcomes using autologous oocyte vitrification and warming are as good as cycles using fresh oocytes. These results are especially reassuring for infertile patients who must cryopreserve oocytes owing to unavailability of sperm or who wish to limit the number of oocytes inseminated. Age-associated estimates of oocyte to live-born child efficiencies are particularly useful in providing more explicit expectations regarding potential births for elective oocyte cryopreservation.


Assuntos
Criopreservação , Preservação da Fertilidade/métodos , Fertilização in vitro , Recuperação de Oócitos , Oócitos , Vitrificação , Adulto , Fatores Etários , Transferência Embrionária , Feminino , Fertilização in vitro/efeitos adversos , Humanos , Nascido Vivo , Recuperação de Oócitos/efeitos adversos , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
7.
Fertil Steril ; 106(2): 354-362.e2, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27172399

RESUMO

OBJECTIVE: To evaluate factors associated with cryopreserved blastocyst transfer birth outcomes, including age, expansion time, cryopreservation protocol, cryodamage, and number of embryos transferred. DESIGN: Retrospective cohort study. SETTING: Private infertility practice. PATIENT(S): Cryopreserved blastocyst transfer patients from January 2003 to April 2012. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Birth per transfer and children per embryo. RESULT(S): Overall live birth per transfer was 32%, with 17% twin births and 0.3% triplets. Live birth per transfer was significantly higher for vitrification compared with slow-freeze (day 5 cryopreservation: 47% vs. 35%; day 6 cryopreservation: 46% vs. 24%), as was live born children per transferred embryo (39% vs. 29% for day 5; 36% vs. 18% for day 6). Birth rates declined only slightly with increasing age at cryopreservation through 37 years, followed by an increasingly rapid decline in success with increasing age thereafter. Live birth rates declined rapidly (49%-18% for vitrification and 37%-10% for slow-freeze) as the percentage of intact cells after cryopreservation decreased from 95%-100% to 70%-79%, with almost no births when the percentage of intact cells was <70%. Increasing numbers of embryos per transfer were associated with significant increase in live birth per transfer but significant decrease in children per transferred embryo. Birth rates were much lower for blastocysts with delayed expansion on day 7 (10% per transfer). CONCLUSION(S): Birth outcomes from cryopreserved blastocyst transfer are influenced by age, timing of expansion, cryopreservation protocol, visible cryodamage, and the number of embryos transferred. Vitrification substantially improves outcomes versus slow freezing.


Assuntos
Blastômeros/fisiologia , Criopreservação , Transferência Embrionária , Infertilidade/terapia , Criopreservação/métodos , Implantação do Embrião , Transferência Embrionária/efeitos adversos , Transferência Embrionária/métodos , Feminino , Fertilidade , Fertilização in vitro , Humanos , Infertilidade/diagnóstico , Infertilidade/fisiopatologia , Gravidez , Taxa de Gravidez , Gravidez de Trigêmeos , Gravidez de Gêmeos , Estudos Retrospectivos , Fatores de Risco , Transferência de Embrião Único , Fatores de Tempo , Resultado do Tratamento
8.
Fertil Steril ; 80(2): 453-5, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12909515

RESUMO

OBJECTIVE: To perform preimplantation genetic diagnosis (PGD) with 1.48-microm infrared diode laser assistance during embryo biopsy for two patients undergoing IVF. DESIGN: Case reports. SETTING: Private ART laboratory. Two couples undergoing IVF for infertility therapy, both of whom had previously delivered offspring afflicted with spinal muscular atrophy (type 1) after IVF therapy, and who underwent subsequent cycles of IVF coupled with PGD to screen for this disorder. INTERVENTION(S): Two individual IVF cases involving intracytoplasmic sperm injection (ICSI), embryo biopsy with laser assistance, and PGD. The ease and apparent safety of human embryo biopsy using a 1.48-microm infrared laser for partial zona pellucida (ZP) dissection to assist with embryo blastomere biopsy was evaluated. RESULT(S): Both couples were deemed to have some unafflicted embryos for transfer on the fifth day of development after blastomere biopsy in conjunction with PGD. Patient A had a singleton pregnancy and delivered a healthy normal singleton male. Patient B had a twin pregnancy; however, one twin was spontaneously lost at 10 weeks but she ultimately delivered a healthy normal singleton male. CONCLUSION(S): These successful outcomes help to demonstrate the efficacy and safety of laser-assisted embryo biopsy to facilitate PGD screening.


Assuntos
Embrião de Mamíferos/patologia , Lasers , Atrofia Muscular Espinal/diagnóstico , Atrofia Muscular Espinal/genética , Diagnóstico Pré-Implantação , Adulto , Biópsia , Embrião de Mamíferos/fisiologia , Desenvolvimento Embrionário e Fetal , Feminino , Fertilização in vitro , Humanos , Recém-Nascido , Masculino , Gravidez , Diagnóstico Pré-Implantação/métodos , Injeções de Esperma Intracitoplásmicas , Resultado do Tratamento
9.
Fertil Steril ; 77(3): 615-7, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11872221

RESUMO

OBJECTIVE: To report a normal twin delivery after transfer of two fresh day 7 blastocysts. DESIGN: Case report. SETTING: Private infertility clinic. PATIENT(S): A 35-year-old woman with a 6-year history of primary infertility with significant pelvic adhesions. INTERVENTION(S): Review of individual IVF-ET therapy cycle. MAIN OUTCOME MEASURE(S): Full-term delivery after day 7 blastocyst transfer. RESULT(S): During the patient's first IVF-ET cycle, the decision was made to undertake blastocyst transfer after extended culture. No blastocysts had formed until late on day 6, by which time the patient had been hospitalized with a renal stone. Subsequently, on day 7, the patient was asymptomatic and presented for embryo transfer, and after assisted hatching, two expanded blastocysts were transferred to her uterus under ultrasound guidance. After confirmation of implantation of a viable twin, pregnancy was uneventful with no obstetrical complications, and a dizygotic twin was delivered vaginally at 38 weeks of gestation. CONCLUSION(S): Few reports have been made regarding viability of more slowly developing blastocysts; however, this case indicates that blastocysts that did not fully expand until day 7 of extended in vitro culture are still able to implant after superovulation and IVF-ET therapy. Assisted hatching of these embryos may have been beneficial in achieving this successful outcome by hastening the blastocyst hatching, allowing more rapid contact with the endometrium.


Assuntos
Blastocisto/fisiologia , Transferência Embrionária , Desenvolvimento Embrionário e Fetal/fisiologia , Fertilização in vitro , Adulto , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Resultado da Gravidez , Gravidez Múltipla
10.
Neurotoxicology ; 42: 33-48, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24705302

RESUMO

The potential for adverse neurotoxic reactions in response to therapeutics and environmental hazards continues to prompt development of novel cell-based assays to determine neurotoxic risk. A challenge remains to characterize and understand differences between assays and between neuronal cellular models in their responses to neurotoxicants if scientists are to determine the optimal model, or combination of models, for neurotoxicity screening. Most studies to date have focused on developmental neurotoxicity applications. This study reports the development of a robust multiparameter High Content Analysis (HCA) assay for neurotoxicity screening in three differentiated neuronal cell models - SH-SY5Y, PC12 and human embryonic stem cell-derived hN2™ cells. Using a multiplexed detection reagent panel (Hoechst nuclear stain; antibodies against ßIII-Tubulin and phosphorylated neurofilament subunit H, and Mitotracker(®) Red CMXRos), a multiparametric HCA assay was developed and used to characterize a test set of 36 chemicals. HCA data generated were compared to data generated using MTT and LDH assays under the same assay conditions. Data showed that multiparametric High Content Analysis of differentiated neuronal cells is feasible, and represents a highly effective method for obtaining large quantities of robust data on the neurotoxic effects of compounds compared with cytotoxicity assays like MTT and LDH. Significant differences were observed between the responses to compounds across the three cellular models tested, illustrating the heterogeneity in responses to neurotoxicants across different cell types. This study provides data strongly supporting the use of cellular imaging as a tool for neurotoxicity assessment in differentiated neuronal cells, and provides novel insights into the neurotoxic effects of a test set of compounds upon differentiated neuronal cell lines and human embryonic stem cell-derived neurons.


Assuntos
Citotoxinas/toxicidade , Células-Tronco Embrionárias/citologia , Poluentes Ambientais/toxicidade , Ensaios de Triagem em Larga Escala/métodos , Células-Tronco Neurais/citologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Neurônios/citologia , Células PC12 , Ratos
11.
Fertil Steril ; 99(6): 1631-6, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23433518

RESUMO

OBJECTIVE: To estimate whether live birth in single-blastocyst transfers is correlated with the number of sibling supernumerary vitrified blastocysts (embryos not transferred) generated from that same cycle. DESIGN: Retrospective cohort study. SETTING: A large academic assisted reproduction clinic. PATIENT(S): All single-blastocyst transfers in 2010 graded as "good" embryos by Society for Assisted Reproductive Technologies (SART) criteria. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Implantation and live birth. RESULT(S): Of the 655 single-blastocyst transfers that met inclusion criteria, implantation occurred in 65% and live birth in 54% of cycles. In chi-square analysis, patients with supernumerary vitrified blastocysts had a statistically higher implantation rate (65% versus 50%) and live-birth rate (56% versus 41%) when compared with patients without supernumerary blastocysts. Univariate logistic regression demonstrated an increase in implantation (OR 1.09; 95% CI, 1.03-1.15) and live birth (OR 1.06; 95% CI, 1.02-1.09) with increasing number of supernumerary blastocysts. Multivariate logistic regression analysis demonstrated that patient age and the number of supernumerary blastocysts were statistically significantly associated with implantation and live birth. CONCLUSION(S): The number of supernumerary vitrified blastocysts correlated positively with the odds of implantation and live birth in good quality single-blastocyst transfers. Patients with supernumerary blastocysts are good candidates for single-embryo transfer.


Assuntos
Blastocisto , Implantação do Embrião , Nascido Vivo/epidemiologia , Transferência de Embrião Único/tendências , Vitrificação , Adulto , Blastocisto/fisiologia , Estudos de Coortes , Implantação do Embrião/fisiologia , Feminino , Humanos , Gravidez , Estudos Retrospectivos , Transferência de Embrião Único/métodos
12.
Fertil Steril ; 99(5): 1283-1289.e1, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23312233

RESUMO

OBJECTIVE: To estimate the effect of the embryo stage, trophectoderm (TE) morphology grade, and inner cell mass (ICM) morphology grade on live birth in single-blastocyst transfers. DESIGN: Retrospective cohort study. SETTING: Large private assisted reproductive technologies (ART) practice. PATIENT(S): Fresh autologous ART cycles. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Live birth. RESULT(S): A total of 694 single-blastocyst transfers met the inclusion criteria. Univariate regression analysis showed embryo stage and TE score to be correlated with implantation and live birth. Live birth rates were 57%, 40%, and 25% for TE grades A, B, and C, respectively. There was no significant association between ICM grade and implantation or live birth. Live birth rates were 53%, 52%, and 0% for ICM grades A, B, and C respectively. Multiple logistic regression analysis showed that only patient age and TE grade were significantly associated with implantation and live birth, whereas ICM grade was not significantly associated with outcome. The TE score had the strongest correlation with live birth. CONCLUSION(S): TE grading, but not ICM grading, significantly correlated with implantation and live birth for single-blastocyst transfers.


Assuntos
Aborto Espontâneo/diagnóstico , Massa Celular Interna do Blastocisto/citologia , Técnicas de Cultura Embrionária/métodos , Fertilização in vitro/métodos , Taxa de Gravidez , Transferência de Embrião Único/métodos , Aborto Espontâneo/epidemiologia , Massa Celular Interna do Blastocisto/fisiologia , Técnicas de Cultura Embrionária/estatística & dados numéricos , Implantação do Embrião , Desenvolvimento Embrionário/fisiologia , Feminino , Humanos , Valor Preditivo dos Testes , Gravidez , Estudos Retrospectivos , Fatores de Risco , Transferência de Embrião Único/estatística & dados numéricos
13.
Fertil Steril ; 92(6): 1895-906, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18976755

RESUMO

OBJECTIVE: To evaluate efforts to reduce twin pregnancies through progressive implementation of elective single embryo transfer (eSET) among select patients over a 6-year period. DESIGN: Retrospective review. SETTING: Private practice IVF center. PATIENT(S): Infertile women undergoing 15,418 consecutive IVF-ET cycles. INTERVENTION(S): IVF-ET, including blastocyst-stage eSET among select patients with good prognosis and high risk of multiple pregnancy. MAIN OUTCOME MEASURE(S): Pregnancy, multiple pregnancy, method of payment. RESULT(S): Pregnancy rates were similar for autologous eSET versus double-blastocyst transfer (65% vs. 63%), while twin rates were much lower (1% vs. 44%). For recipients of donor oocytes, pregnancy rates were slightly lower with eSET (63% vs. 74%), while twin rates were much lower (2% vs. 54%). There was no decrease in overall pregnancy rates, despite a dramatic rise in eSET use over time (1.5% to 8.6% of all autologous transfers and 2.0% to 22.5% of all transfers to donor oocyte recipients between 2002 and 2007). Overall singleton pregnancy rates increased, while twin pregnancy rates declined significantly over time. Use of eSET was significantly more common among patients with insurance coverage or who were participating in our Shared Risk money-back guarantee program. CONCLUSION(S): Selective eSET use among good-prognosis patients can significantly reduce twin pregnancies without compromising pregnancy rates. Patients are more likely to choose eSET when freed from financial pressures to transfer multiple embryos.


Assuntos
Fertilização in vitro/economia , Fertilização in vitro/estatística & dados numéricos , Infertilidade Feminina , Transferência de Embrião Único/economia , Transferência de Embrião Único/estatística & dados numéricos , Adulto , Distribuição por Idade , Comportamento de Escolha , Feminino , Custos de Cuidados de Saúde , Humanos , Infertilidade Feminina/economia , Infertilidade Feminina/epidemiologia , Infertilidade Feminina/terapia , Seguro Saúde/estatística & dados numéricos , Gravidez , Taxa de Gravidez , Gravidez de Alto Risco , Gravidez Múltipla , Prognóstico , Estudos Retrospectivos , Fatores de Risco
14.
Science ; 322(5906): 1345-8, 2008 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-19008414

RESUMO

Fomalhaut, a bright star 7.7 parsecs (25 light-years) from Earth, harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate, Fomalhaut b. Fomalhaut b lies about 119 astronomical units (AU) from the star and 18 AU of the dust belt, matching predictions of its location. Hubble Space Telescope observations separated by 1.73 years reveal counterclockwise orbital motion. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter; a higher mass would lead to gravitational disruption of the belt, matching predictions of its location. The flux detected at 0.8 mum is also consistent with that of a planet with mass no greater than a few times that of Jupiter. The brightness at 0.6 mum and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observe variability of unknown origin at 0.6 mum.

15.
Anal Biochem ; 375(2): 255-64, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18275835

RESUMO

Aberrant epidermal growth factor receptor (EGFR, ErbB1) signaling is implicated in cell transformation, motility, and invasion in a variety of cell types, and EGFR is the target of several anticancer drugs. However, the kinetics of EGFR signaling and the individual contributions of site-specific phosphorylation events remain largely unknown. A peptide-based, multiplex immunoassay approach was developed to simultaneously measure both total and phosphorylated protein in a single sample. The approach involves the proteolytic digestion of proteins prior to the isolation and quantitation of site-specific phosphorylation events within an individual protein. Quantitation of phosphorylated and total proteins, in picomolar to nanomolar concentrations, were interpolated from standard curves generated with synthetic peptides that correspond to the peptide targets used in the immunoassays. In this study, a bead-based, nine-plex immunoassay measuring total and phosphorylated protein was constructed to measure temporal, site-specific phosphorylation of key members of the EGFR pathway (ErbB1 receptor, MEK1, MEK2, ERK1, and ERK2) in A431 cells stimulated with epidermal growth factor. The effect of MEK inhibition on this pathway was determined using a known MEK kinase inhibitor, SL327. The results reported herein are the first quantitative measurements of site-specific phosphorylation events and total proteins in a single sample, at the same time representing a new paradigm for standardized protein and phosphorylation analysis using multiplexed, peptide-based, sandwich immunoassays.


Assuntos
Fator de Crescimento Epidérmico/imunologia , Fator de Crescimento Epidérmico/metabolismo , Imunoensaio/métodos , Proteínas Quinases Ativadas por Mitógeno/imunologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Peptídeos/imunologia , Sequência de Aminoácidos , Linhagem Celular Tumoral , Fator de Crescimento Epidérmico/análise , Epitopos/imunologia , Humanos , Proteínas Quinases Ativadas por Mitógeno/análise , Dados de Sequência Molecular , Fosforilação , Transdução de Sinais , Fatores de Tempo
16.
Reprod Biomed Online ; 4(2): 146-50, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12470577

RESUMO

The purpose of this study was to demonstrate the safety and efficacy of vitrification of human pronuclear stage (PN) embryos in the human assisted reproduction laboratory. Using single pronucleate (1PN) and three pronucleate (3PN) zygotes, the impact of vitrification in the Flexipet denuding pipette (FDP) as a carrier was assessed in terms of survival, embryonic development and blastocyst formation when compared according to the PN number, and unvitrified controls. A total of 65 1PN and 152 3PN zygotes were vitrified; after warming 82% (53/65) of 1PN and 90% (137/152) of 3PN survived. The overall percentage of warmed zygotes (1PN and 3PN) that cleaved and reached 2-cell stage did not differ (chi(2); P = 0.32) from the control groups (77%; 147/190 versus 85%; 115/136). In addition, when the cleavage behaviour was examined on day 3 for >or=4-cell stage, no significant differences (chi(2); P = 0.95) were observed between the vitrified group and the unvitrified control groups (74%; 109/147 versus 77%; 89/115). Comparing the developmental potential up to cavitation and blastocyst formation on day 5, the overall outcome of the vitrified PN was 31% compared with 33% for the controls (chi(2); P = 0.76). The simple vitrification protocol used in this study, and these data highlight the usefulness of vitrification using FDP as a consistent and effective cryopreservation method for pronuclear zygotes, and a suitable alternative to slow cryopreservation protocols.


Assuntos
Blastocisto/fisiologia , Criopreservação/instrumentação , Zigoto/fisiologia , Blastômeros , Fase de Clivagem do Zigoto , Desenvolvimento Embrionário e Fetal , Temperatura Alta , Humanos
17.
Science ; 303(5662): 1345-8, 2004 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-14988558

RESUMO

We have used laser guide star adaptive optics and a near-infrared dual-channel imaging polarimeter to observe light scattered in the circumstellar environment of Herbig Ae/Be stars on scales of 100 to 300 astronomical units. We revealed a strongly polarized, biconical nebula 10 arc seconds (6000 astronomical units) in diameter around the star LkHalpha 198 and also observed a polarized jet-like feature associated with the deeply embedded source LkHalpha 198-IR. The star LkHalpha 233 presents a narrow, unpolarized dark lane consistent with an optically thick circumstellar disk blocking our direct view of the star. These data show that the lower-mass T Tauri and intermediate mass Herbig Ae/Be stars share a common evolutionary sequence.

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