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1.
Conscious Cogn ; 64: 19-31, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29789209

RESUMEN

Saccades rapidly jerk the eye into new positions, yet we rarely experience the motion streaks imposed on the retinal image. Here we examined spatial and temporal properties of post-saccadic masking-one potential explanation of this perceptual omission. Observers judged the motion direction of a target stimulus, a Gaussian blob, that moved vertically upwards or downwards and then back to its initial position, just as observers made a saccade. We manipulated the onset and offset of the target and of distractors in various spatial relations to the target, and assessed their effect on performance and subjective confidence. Although the presence of the target after the saccade caused the strongest omission, the offset of spatially distant distractor stimuli upon saccade offset also impaired performance. The temporal properties of these two separate effects suggest that, in addition to masking, an independent effect of attentional distraction further accentuates perceptual omission of intra-saccadic motion streaks.


Asunto(s)
Percepción de Movimiento/fisiología , Enmascaramiento Perceptual/fisiología , Movimientos Sacádicos/fisiología , Percepción Espacial/fisiología , Humanos
2.
Public Health ; 158: 149-155, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29631727

RESUMEN

OBJECTIVES: Refugee women entering resettlement countries on woman-at-risk visas represent a particularly vulnerable population. While their specific gender-based resettlement will likely differ from the general refugee population, little is known about their experiences of early resettlement, with which to inform resettlement policy and practice. This research aimed to explore lived experiences of recently resettled refugee women at risk in Australia. STUDY DESIGN: Qualitative research used focus groups and a framework approach to identify and explicate common themes in participants' experience. METHODS: Two focus groups with a purposive sample of African and Afghan refugee women at risk (N = 10), aged 22-53 years, were conducted in South East Queensland, Australia (October 2016), recruited with the assistance of a local resettlement service. Discussions were audiotaped, transcribed, and themes explicated. RESULTS: Six superordinate themes emerged: (1) sentiment of gratitude; (2) sense of loneliness and disconnection; (3) feeling incapable; (4) experiencing distress and help-seeking; (5) experiencing financial hardship; and (6) anticipating the future. CONCLUSIONS: Findings indicate that resettlement policy, programs, and practice that explicitly target the needs of women-at-risk refugees are warranted, including a longer period of active service provision with specific attention to strategies that address the women's social connection, self-efficacy, emotional well-being, and financial hardships.


Asunto(s)
Adaptación Psicológica , Emigrantes e Inmigrantes/psicología , Refugiados/psicología , Adulto , Afganistán/etnología , África/etnología , Emigrantes e Inmigrantes/estadística & datos numéricos , Femenino , Grupos Focales , Humanos , Persona de Mediana Edad , Investigación Cualitativa , Queensland , Refugiados/estadística & datos numéricos , Poblaciones Vulnerables , Adulto Joven
3.
Mol Psychiatry ; 20(11): 1266-85, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26283638

RESUMEN

Worldwide, one person dies every 40 seconds by suicide, a potentially preventable tragedy. A limiting step in our ability to intervene is the lack of objective, reliable predictors. We have previously provided proof of principle for the use of blood gene expression biomarkers to predict future hospitalizations due to suicidality, in male bipolar disorder participants. We now generalize the discovery, prioritization, validation, and testing of such markers across major psychiatric disorders (bipolar disorder, major depressive disorder, schizoaffective disorder, and schizophrenia) in male participants, to understand commonalities and differences. We used a powerful within-participant discovery approach to identify genes that change in expression between no suicidal ideation and high suicidal ideation states (n=37 participants out of a cohort of 217 psychiatric participants followed longitudinally). We then used a convergent functional genomics (CFG) approach with existing prior evidence in the field to prioritize the candidate biomarkers identified in the discovery step. Next, we validated the top biomarkers from the prioritization step for relevance to suicidal behavior, in a demographically matched cohort of suicide completers from the coroner's office (n=26). The biomarkers for suicidal ideation only are enriched for genes involved in neuronal connectivity and schizophrenia, the biomarkers also validated for suicidal behavior are enriched for genes involved in neuronal activity and mood. The 76 biomarkers that survived Bonferroni correction after validation for suicidal behavior map to biological pathways involved in immune and inflammatory response, mTOR signaling and growth factor regulation. mTOR signaling is necessary for the effects of the rapid-acting antidepressant agent ketamine, providing a novel biological rationale for its possible use in treating acute suicidality. Similarly, MAOB, a target of antidepressant inhibitors, was one of the increased biomarkers for suicidality. We also identified other potential therapeutic targets or biomarkers for drugs known to mitigate suicidality, such as omega-3 fatty acids, lithium and clozapine. Overall, 14% of the top candidate biomarkers also had evidence for involvement in psychological stress response, and 19% for involvement in programmed cell death/cellular suicide (apoptosis). It may be that in the face of adversity (stress), death mechanisms are turned on at a cellular (apoptosis) and organismal level. Finally, we tested the top increased and decreased biomarkers from the discovery for suicidal ideation (CADM1, CLIP4, DTNA, KIF2C), prioritization with CFG for prior evidence (SAT1, SKA2, SLC4A4), and validation for behavior in suicide completers (IL6, MBP, JUN, KLHDC3) steps in a completely independent test cohort of psychiatric participants for prediction of suicidal ideation (n=108), and in a future follow-up cohort of psychiatric participants (n=157) for prediction of psychiatric hospitalizations due to suicidality. The best individual biomarker across psychiatric diagnoses for predicting suicidal ideation was SLC4A4, with a receiver operating characteristic (ROC) area under the curve (AUC) of 72%. For bipolar disorder in particular, SLC4A4 predicted suicidal ideation with an AUC of 93%, and future hospitalizations with an AUC of 70%. SLC4A4 is involved in brain extracellular space pH regulation. Brain pH has been implicated in the pathophysiology of acute panic attacks. We also describe two new clinical information apps, one for affective state (simplified affective state scale, SASS) and one for suicide risk factors (Convergent Functional Information for Suicide, CFI-S), and how well they predict suicidal ideation across psychiatric diagnoses (AUC of 85% for SASS, AUC of 89% for CFI-S). We hypothesized a priori, based on our previous work, that the integration of the top biomarkers and the clinical information into a universal predictive measure (UP-Suicide) would show broad-spectrum predictive ability across psychiatric diagnoses. Indeed, the UP-Suicide was able to predict suicidal ideation across psychiatric diagnoses with an AUC of 92%. For bipolar disorder, it predicted suicidal ideation with an AUC of 98%, and future hospitalizations with an AUC of 94%. Of note, both types of tests we developed (blood biomarkers and clinical information apps) do not require asking the individual assessed if they have thoughts of suicide, as individuals who are truly suicidal often do not share that information with clinicians. We propose that the widespread use of such risk prediction tests as part of routine or targeted healthcare assessments will lead to early disease interception followed by preventive lifestyle modifications and proactive treatment.


Asunto(s)
Expresión Génica/fisiología , Genómica/métodos , Trastornos Mentales , Suicidio , Adulto , Biomarcadores , Estudios de Cohortes , Bases de Datos Genéticas/estadística & datos numéricos , Femenino , Perfilación de la Expresión Génica , Humanos , Masculino , Trastornos Mentales/genética , Trastornos Mentales/metabolismo , Trastornos Mentales/psicología , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Valor Predictivo de las Pruebas , Escalas de Valoración Psiquiátrica , Medición de Riesgo , Factores de Riesgo , Adulto Joven
4.
J Periodontal Res ; 50(6): 870-80, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26031604

RESUMEN

BACKGROUND AND OBJECTIVE: The structural and functional integrity of bone-periodontal ligament (PDL)-cementum complex stems from the load-bearing attachment sites (entheses) between soft (PDL) and hard (bone, cementum) tissues. These attachment sites are responsible for the maintenance of a bone-PDL-cementum complex biomechanical function. The objective was to investigate changes in spatiotemporal expression of key biomolecules in developing and functionally active entheses. MATERIAL AND METHODS: Multilabeling technique was performed on hemimandibles of 3 wk and 3 mo-old scleraxis-GFP transgenic mice for CD146, CD31, NG2, osterix and bone sialoprotein. Regions of dominant stretch within the PDL were evaluated by identifying directionality of collagen fibrils, PDL fibroblasts and PDL cell cytoskeleton. RESULTS: CD146+ cells adjacent to CD31+ vasculature were identified at PDL-bone enthesis. NG2+ cells were located at coronal bone-PDL and apical cementum-PDL entheses in the 3-wk-old group, but at 3 mo, NG2 was positive at the entheses of the apical region and alveolar crest. NG2 and osterix were colocalized at the osteoid and cementoid regions of the PDL-bone and PDL-cementum entheses. Bone sialoprotein was prominent at the apical region of 3-wk-old mice. The directionality of collagen fibers, fibroblasts and their cytoskeleton overlapped, except in the apical region of 3 wk. CONCLUSION: Colocalization of biomolecules at zones of the PDL adjacent to attachment sites may be essential for the formation of precementum and osteoid interfaces at a load-bearing bone-PDL-tooth fibrous joint. Biophysical cues resulting from development and function can regulate recruitment and differentiation of stem cells potentially from a vascular origin toward osteo- and cemento-blastic lineages at the PDL-bone and PDL-cementum entheses. Investigating the coupled effect of biophysical and biochemical stimuli leading to cell differentiation at the functional attachment sites is critical for developing regeneration strategies to enable functional reconstruction of the periodontal complex.


Asunto(s)
Huesos/fisiología , Cemento Dental/fisiología , Perfilación de la Expresión Génica , Ligamento Periodontal/fisiología , Animales , Antígenos/análisis , Antígenos CD/análisis , Fenómenos Biofísicos , Diferenciación Celular , Histocitoquímica , Ratones Transgénicos , Ligamento Periodontal/citología , Proteoglicanos/análisis , Sialoglicoproteínas/análisis , Factor de Transcripción Sp7 , Análisis Espacio-Temporal , Factores de Transcripción/análisis
6.
Mol Psychiatry ; 18(12): 1249-64, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23958961

RESUMEN

Suicides are a leading cause of death in psychiatric patients, and in society at large. Developing more quantitative and objective ways (biomarkers) for predicting and tracking suicidal states would have immediate practical applications and positive societal implications. We undertook such an endeavor. First, building on our previous blood biomarker work in mood disorders and psychosis, we decided to identify blood gene expression biomarkers for suicidality, looking at differential expression of genes in the blood of subjects with a major mood disorder (bipolar disorder), a high-risk population prone to suicidality. We compared no suicidal ideation (SI) states and high SI states using a powerful intrasubject design, as well as an intersubject case-case design, to generate a list of differentially expressed genes. Second, we used a comprehensive Convergent Functional Genomics (CFG) approach to identify and prioritize from the list of differentially expressed gene biomarkers of relevance to suicidality. CFG integrates multiple independent lines of evidence-genetic and functional genomic data-as a Bayesian strategy for identifying and prioritizing findings, reducing the false-positives and false-negatives inherent in each individual approach. Third, we examined whether expression levels of the blood biomarkers identified by us in the live bipolar subject cohort are actually altered in the blood in an age-matched cohort of suicide completers collected from the coroner's office, and report that 13 out of the 41 top CFG scoring biomarkers (32%) show step-wise significant change from no SI to high SI states, and then to the suicide completers group. Six out of them (15%) remained significant after strict Bonferroni correction for multiple comparisons. Fourth, we show that the blood levels of SAT1 (spermidine/spermine N1-acetyltransferase 1), the top biomarker identified by us, at the time of testing for this study, differentiated future as well as past hospitalizations with suicidality, in a live cohort of bipolar disorder subjects, and exhibited a similar but weaker pattern in a live cohort of psychosis (schizophrenia/schizoaffective disorder) subjects. Three other (phosphatase and tensin homolog (PTEN), myristoylated alanine-rich protein kinase C substrate (MARCKS), and mitogen-activated protein kinase kinase kinase 3 (MAP3K3)) of the six biomarkers that survived Bonferroni correction showed similar but weaker effects. Taken together, the prospective and retrospective hospitalization data suggests SAT1, PTEN, MARCKS and MAP3K3 might be not only state biomarkers but trait biomarkers as well. Fifth, we show how a multi-dimensional approach using SAT1 blood expression levels and two simple visual-analog scales for anxiety and mood enhances predictions of future hospitalizations for suicidality in the bipolar cohort (receiver-operating characteristic curve with area under the curve of 0.813). Of note, this simple approach does not directly ask about SI, which some individuals may deny or choose not to share with clinicians. Lastly, we conducted bioinformatic analyses to identify biological pathways, mechanisms and medication targets. Overall, suicidality may be underlined, at least in part, by biological mechanisms related to stress, inflammation and apoptosis.


Asunto(s)
Biomarcadores/sangre , Ideación Suicida , Acetiltransferasas/genética , Adulto , Anciano , Trastorno Bipolar/sangre , Trastorno Bipolar/genética , Trastorno Bipolar/psicología , Expresión Génica/genética , Perfilación de la Expresión Génica , Genómica/métodos , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , MAP Quinasa Quinasa Quinasa 3/genética , Masculino , Proteínas de la Membrana/genética , Persona de Mediana Edad , Sustrato de la Proteína Quinasa C Rico en Alanina Miristoilada , Análisis de Secuencia por Matrices de Oligonucleótidos , Fosfohidrolasa PTEN/genética , Trastornos Psicóticos/sangre , Suicidio/psicología
7.
Development ; 128(19): 3855-66, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11585810

RESUMEN

Little is known about the genesis and patterning of tendons and other connective tissues, mostly owing to the absence of early markers. We have found that Scleraxis, a bHLH transcription factor, is a highly specific marker for all the connective tissues that mediate attachment of muscle to bone in chick and mouse, including the limb tendons, and show that early scleraxis expression marks the progenitor cell populations for these tissues. In the early limb bud, the tendon progenitor population is found in the superficial proximomedial mesenchyme. Using the scleraxis gene as a marker we show that these progenitors are induced by ectodermal signals and restricted by bone morphogenetic protein (BMP) signaling within the mesenchyme. Application of Noggin protein antagonizes this endogenous BMP activity and induces ectopic scleraxis expression. However, the presence of excess tendon progenitors does not lead to the production of additional or longer tendons, indicating that additional signals are required for the final formation of a tendon. Finally, we show that the endogenous expression of noggin within the condensing digit cartilage contributes to the induction of distal tendons.


Asunto(s)
Tendones/citología , Tendones/embriología , Factores de Transcripción/metabolismo , Animales , Proteínas Aviares , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Biomarcadores , Proteínas Morfogenéticas Óseas/metabolismo , Proteínas Portadoras , Embrión de Pollo , Tejido Conectivo/embriología , Tejido Conectivo/metabolismo , Ectodermo/metabolismo , Regulación del Desarrollo de la Expresión Génica , Esbozos de los Miembros/citología , Esbozos de los Miembros/metabolismo , Proteínas/metabolismo , Transducción de Señal , Células Madre/metabolismo , Tendones/metabolismo , Factores de Transcripción/genética
8.
Mech Dev ; 102(1-2): 223-6, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11287197

RESUMEN

We have isolated a new chicken gene that is a member of the cysteine-rich secreted protein family (CRISP). The CRISP family is composed of over 70 members that are found in many phyla of organisms, including: vertebrates, plants, fungi, yeast, and insects. Here we describe the cloning of a novel member of this family, SugarCrisp, and its expression pattern throughout chicken embryogenesis. We also describe its utility as a marker of thyroid and pancreatic mesoderm in the developing chicken embryo and its expression within the human and mouse in glandular tissue.


Asunto(s)
Proteínas Aviares , Cisteína/química , Mesodermo/metabolismo , Páncreas/embriología , Biosíntesis de Proteínas , Proteínas/química , Glándula Tiroides/embriología , Secuencia de Aminoácidos , Animales , Embrión de Pollo , Clonación Molecular , ADN Complementario/metabolismo , Embrión no Mamífero/metabolismo , Humanos , Hibridación in Situ , Pulmón/embriología , Datos de Secuencia Molecular , Proteínas/metabolismo , Homología de Secuencia de Aminoácido , Distribución Tisular
9.
J Psychosom Res ; 48(6): 515-24, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11033370

RESUMEN

OBJECTIVES: Qualitative evidence suggests that personality may have special relevance to the predisposition, precipitation and perpetuation of chronic fatigue syndrome (CFS). This study compares three dimensions of personality - perfectionism, self-esteem, and emotional control in the personality profiles of CFS patients (N=44) and a control group (N=44) without a history of CFS, matched for age and gender. METHODS: Participants were assessed on the MPS [Frost RO, Marten P, Lahart C, Rosenblate R. The dimensions of perfectionism. Cognit Ther Res 1990;14:449-468.]; the Rosenberg Self-Esteem Scale [Rosenberg M. Society and the Adolescent Self-image. Princeton, NJ: Princeton Univ Press, 1965.]; the Courtauld Emotional Scale [Watson M, Greer S. Development of a questionnaire measure of emotional control. J Psychosom Res 1983;27:299-305.] and the Marlowe-Crowne Social Desirability Scale [Crowne DP, Marlowe D. A new scale of social desirability independent of psychopathology. J Consult Psychol 1960;24:349-354.]. RESULTS: Analyses revealed that the CFS group reported higher levels than the control group on the Total Perfectionism score and Doubts about Actions and the Concern over Mistakes subscales. Furthermore, the CFS group also reported lower self-esteem than the control group. No difference between the two groups was found on the dimensions of emotional control and social desirability response bias. CONCLUSION: A developmental model of CFS, which considers the predisposing, precipitating, and perpetuating factors that may account for the course of the disorder irrespective of etiology, is proposed. In the context of the results, recommendations for practice and future research are discussed.


Asunto(s)
Síndrome de Fatiga Crónica/psicología , Determinación de la Personalidad , Adolescente , Adulto , Anciano , Mecanismos de Defensa , Femenino , Humanos , Control Interno-Externo , Masculino , Persona de Mediana Edad , Inventario de Personalidad , Autoimagen , Rol del Enfermo , Deseabilidad Social
10.
Mech Dev ; 98(1-2): 171-4, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11044624

RESUMEN

Gli genes encode a family of zinc finger transcription factors that mediate signaling by Hedgehog proteins. We have cloned the chick Gli3 gene and studied its expression in developing chick limbs. Gli3 expression is highly similar to that of chick Gli2. Gli3 mRNA is evenly distributed in the early limb mesenchyme and subsequently downregulated in the posterior mesenchyme by the polarizing activity of Sonic hedgehog. At later stages, Gli3 is expressed in the distal limb mesenchyme.


Asunto(s)
Proteínas de Unión al ADN/genética , Extremidades/embriología , Proteínas del Tejido Nervioso , Proteínas Represoras , Transactivadores , Factores de Transcripción/genética , Proteínas de Xenopus , Secuencia de Aminoácidos , Animales , Embrión de Pollo , Clonación Molecular , Regulación del Desarrollo de la Expresión Génica , Proteínas Hedgehog , Hibridación in Situ , Factores de Transcripción de Tipo Kruppel , Datos de Secuencia Molecular , Proteínas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Homología de Secuencia de Aminoácido , Transducción de Señal , Proteína Gli2 con Dedos de Zinc , Proteína Gli3 con Dedos de Zinc , Dedos de Zinc/genética
11.
Aust N Z J Psychiatry ; 34(5): 829-35, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11037370

RESUMEN

OBJECTIVE: The aim of the study was to assess the relationship between dimensions of perfectionism and suicide ideation in a tertiary student population in Australia. METHOD: The methodology involved 405 students completing the General Health Questionnaire (GHQ-28) which includes a subset of questions which can be used to assess suicide ideation, and the Multidimensional Perfectionism Scale. RESULTS: The presence of suicide ideation was associated with higher scores on total perfectionism and two perfectionism dimensions, and total GHQ scores. There were significant differences between participants with high levels of perfectionism and participants with moderate to low levels of perfectionism on a measure of suicide ideation. Neither gender nor age were associated with differences in the scores, with results indicating high levels of perfectionism may indicate a vulnerability to suicide ideation. CONCLUSIONS: Perfectionism is a valued attribute in high-achieving populations. The question needs to be asked, however, at what cost? The findings indicate that high levels of perfectionism may be associated with an increased vulnerability to suicide ideation. Future research is needed to gain a better understanding of the complex interrelationship between personality and temperament, environmental factors and self-destructive behaviour.


Asunto(s)
Personalidad , Estrés Psicológico , Estudiantes/psicología , Suicidio/psicología , Pensamiento , Adolescente , Adulto , Análisis de Varianza , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vigilancia de la Población , Prevalencia , Queensland , Muestreo , Encuestas y Cuestionarios , Temperamento , Universidades
12.
Int J Med Microbiol ; 290(3): 289-92, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10959732

RESUMEN

We describe a procedure to eliminate contaminating Mycoplasma from Chlamydia pneumoniae (C. pneumoniae) cultures by pulmonary passage in severe combined immunodeficiency mice (SCID). Four weeks after experimental infection only C. pneumoniae could be cultured from the lungs of the infected animals while Mycoplasma could not be detected any longer, as shown by PCR, culture and transmission electron microscopy (TEM).


Asunto(s)
Chlamydophila pneumoniae/aislamiento & purificación , Pulmón/microbiología , Mycoplasma/aislamiento & purificación , Animales , Línea Celular , Chlamydophila pneumoniae/crecimiento & desarrollo , Recuento de Colonia Microbiana , Fluoresceína-5-Isotiocianato , Técnica del Anticuerpo Fluorescente , Colorantes Fluorescentes , Pulmón/patología , Pulmón/ultraestructura , Ratones , Ratones SCID , Microscopía Electrónica , Mycoplasma/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa
13.
Scand J Immunol ; 51(4): 408-14, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10736114

RESUMEN

Immunoglobulin preparations enriched with IgM and IgA are used in the therapy of severe bacterial infections and for the treatment of acute graft-versus-host disease, but not as yet, in the treatment of autoimmune diseases. We investigated the potential of an IgM- and IgA-enriched immunoglobulin preparation to neutralize activity autoantibodies from patients with autoimmune diseases. We demonstrate that Pentaglobin(R) was at least as effective as intravenous immunoglobulin (Sandoglobulin(R)) in inhibiting autoantibody activity. Each of the immunoglobulin isotypes present in Pentaglobin(R) may be responsible for the inhibitory effect. Pentaglobin(R) immobilized on an affinity matrix retained the disease associated autoantibodies and interacted with F(ab')2 fragments of IgG autoantibodies. Suppression of autoantibody activity is dependent, at least in part, on idiotypic interactions. The present findings provide a rationale for considering these preparations for the immunomodulation of autoimmune disease.


Asunto(s)
Autoanticuerpos/inmunología , Enfermedades Autoinmunes/inmunología , Inmunoglobulina A/inmunología , Inmunoglobulina M/inmunología , Inmunoglobulinas Intravenosas/inmunología , Cromatografía de Afinidad , Humanos , Inmunoglobulina G/inmunología , Idiotipos de Inmunoglobulinas/inmunología , Pruebas de Neutralización
16.
Nature ; 398(6729): 714-8, 1999 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-10227294

RESUMEN

The p63 gene, a homologue of the tumour-suppressor p53, is highly expressed in the basal or progenitor layers of many epithelial tissues. Here we report that mice homozygous for a disrupted p63 gene have major defects in their limb, craniofacial and epithelial development. p63 is expressed in the ectodermal surfaces of the limb buds, branchial arches and epidermal appendages, which are all sites of reciprocal signalling that direct morphogenetic patterning of the underlying mesoderm. The limb truncations are due to a failure to maintain the apical ectodermal ridge, a stratified epithelium, essential for limb development. The embryonic epidermis of p63-/- mice undergoes an unusual process of non-regenerative differentiation, culminating in a striking absence of all squamous epithelia and their derivatives, including mammary, lacrymal and salivary glands. Taken together, our results indicate that p63 is critical for maintaining the progenitor-cell populations that are necessary to sustain epithelial development and morphogenesis.


Asunto(s)
Tipificación del Cuerpo/genética , Epitelio/embriología , Miembro Anterior/embriología , Expresión Génica , Miembro Posterior/embriología , Proteínas de la Membrana , Fosfoproteínas/genética , Cráneo/embriología , Transactivadores , Animales , Diferenciación Celular/genética , Anomalías Craneofaciales/genética , Epidermis/embriología , Epidermis/crecimiento & desarrollo , Epitelio/crecimiento & desarrollo , Femenino , Factor 8 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos/genética , Miembro Anterior/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Técnicas de Transferencia de Gen , Miembro Posterior/crecimiento & desarrollo , Esbozos de los Miembros , Deformidades Congénitas de las Extremidades/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Morfogénesis/genética , Cráneo/crecimiento & desarrollo
17.
J Biomol Screen ; 4(3): 121-127, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10838420

RESUMEN

The demand to increase throughput in HTS programs, without a concomitant addition to costs, has grown significantly during the past few years. One approach to handle this demand is assay miniaturization, which can provide greater throughput, as well as significant cost savings through reduced reagent costs. Currently, one of the major challenges facing assay miniaturization is the ability to detect the assay signal accurately and rapidly in miniaturized formats. Digital imaging is a detection method that can measure fluorescent or luminescent signals in these miniaturized formats. In this study, an imaging system capable of detecting the signal from a fluorescent protease assay in multiple plate formats was used to evaluate this detection method in an HTS environment. A direct comparison was made between the results obtained from the imaging system and a fluorescent plate reader by screening 8,800 compounds in a 96-well plate format. The imaging system generated similar changes in relative signal for each well in the screen, identified the same active compounds, and yielded similar IC(50) values as compared to the plate reader. When a standard protease inhibitor was evaluated in 96-, 384-, 864-, and 1536-well plates using imaging detection, similar IC(50) values were obtained. Furthermore, similar dose-response curves were generated for the compound in 96- and 384-well assay plates read in a plate reader. These results provide support for digital imaging as an accurate and rapid detection method for high-density microtiter plates.

18.
Genes Dev ; 12(7): 908-13, 1998 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-9531530

RESUMEN

In Drosophila the function of the epidermal growth factor (EGF) receptor is modulated zygotically by three EGF-like proteins: Spitz (Spi), which is a potent activator; Vein (Vn), which is a moderate activator; and Argos (Aos), which is an inhibitor. Chimeric molecules were constructed in which the EGF domain of Vn was swapped with the EGF domain from each factor. The modified Vn proteins behaved both in vitro and in vivo with properties characteristic of the factor from which the EGF domain was derived. These results demonstrate that the EGF domain is the key determinant that gives DER inhibitors and activators their distinct properties.


Asunto(s)
Proteínas de Drosophila , Drosophila/genética , Factor de Crecimiento Epidérmico/genética , Receptores ErbB/efectos de los fármacos , Ojo/efectos de los fármacos , Neurregulinas , Proteínas Recombinantes de Fusión/farmacología , Alas de Animales/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Factor de Crecimiento Epidérmico/química , Factor de Crecimiento Epidérmico/fisiología , Receptores ErbB/agonistas , Receptores ErbB/antagonistas & inhibidores , Ojo/anatomía & histología , Proteínas del Ojo/química , Proteínas del Ojo/genética , Ingeniería Genética , Proteínas de Insectos/química , Proteínas de Insectos/genética , Proteínas de Insectos/farmacología , Proteínas de Insectos/fisiología , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Fenotipo , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Alas de Animales/anatomía & histología
19.
Development ; 125(2): 191-200, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9486793

RESUMEN

Previous work has demonstrated a role for the Drosophila EGF receptor (Torpedo/DER) and its ligand, Gurken, in the determination of anterioposterior and dorsoventral axes of the follicle cells and oocyte. The roles of DER in establishing the polarity of the follicle cells were examined further, by following the expression of DER-target genes. One class of genes (e.g. kekon) is induced by the DER pathway at all stages. Broad expression of kekon at the stage in which the follicle cells migrate posteriorly over the oocyte, demonstrates the capacity of the pathway to pattern all follicle cells except the ventral-most rows. This may provide the spatial coordinates for the ventral-most follicle cell fates. A second group of target genes (e.g. rhomboid (rho)) is induced only at later stages of oogenesis, and may require additional inputs by signals emanating from the anterior, stretch follicle cells. The function of Rho was analyzed by ectopic expression in the stretch follicle cells, and shown to induce a non-autonomous dorsalizing activity that is independent of Gurken. Rho thus appears to be involved in processing a DER ligand in the follicle cells, to pattern the egg chamber and allow persistent activation of the DER pathway during formation of the dorsal appendages.


Asunto(s)
Tipificación del Cuerpo/fisiología , Proteínas de Drosophila , Drosophila/embriología , Factor de Crecimiento Epidérmico , Receptores ErbB/fisiología , Oogénesis/fisiología , Proteínas Quinasas , Receptores de Péptidos de Invertebrados/fisiología , Transducción de Señal/fisiología , Factor de Crecimiento Transformador alfa , Animales , Movimiento Celular , Receptores ErbB/genética , Regulación del Desarrollo de la Expresión Génica , Genes de Insecto/fisiología , Proteínas de Insectos/fisiología , Proteínas de la Membrana/genética , Proteínas de la Membrana/fisiología , Mutación , Oocitos/química , ARN Mensajero/análisis , Receptores de Péptidos de Invertebrados/genética , Factores de Crecimiento Transformadores/fisiología
20.
Biochemistry ; 36(38): 11351-9, 1997 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-9298954

RESUMEN

Although fluorescence is widely used to study photosynthetic systems, the mechanisms that affect the fluorescence in photosystem II (PSII) are not completely understood. The aim of this study is to define the low-temperature steady-state fluorescence quenching of redox-active centers that function on the electron donor side of PSII. The redox states of the electron donors and acceptors were systematically varied by using a combination of pretreatments and illumination to produce and trap, at low temperature, a specific charge-separated state. Electron paramagnetic resonance spectroscopy and fluorescence intensity measurements were carried out on the same samples to obtain a correlation between the redox state and the fluorescence. It was found that illumination of PSII at temperatures between 85 and 260 K induced a fluorescence quenching state in two phases. At 85 K, where the fast phase was most prominent, only one electron-transfer pathway is active on the donor side of PSII. This pathway involves electron donation to the primary electron donor in PSII, P680, from cytochrome b559 and a redox-active chlorophyll molecule, ChlZ. Oxidized ChlZ was found to be a potent quencher of chlorophyll fluorescence with 15% of oxidized ChlZ sufficient to quench 70% of the fluorescence intensity. This implies that neighboring PSII reaction centers are energetically connected, allowing oxidized ChlZ in a few centers to quench most of the fluorescence. The presence of a well-defined quencher in PSII may make it possible to study the connectivity between antenna systems in different sample preparations. The other redox-active components on the donor side of PSII studied were the O2-evolving complex, the redox-active tyrosines (YZ and YD), and cytochrome b559. No significant changes in fluorescence intensity could be attributed to changes in the redox state of these components. The fast phase of fluorescence quenching is attributed to the rapid photooxidation of ChlZ, and the slow phase is attributed to multiple turnovers providing for further oxidation of ChlZ and irreversible photoinhibition. Significant photoinhibition only occurred at Chl concentrations below 0.7 mg/mL and above 150 K. The reversible oxidation of ChlZ in intact systems may function as a photoprotection mechanism under high-light conditions and account for a portion of the nonphotochemical fluorescence quenching.


Asunto(s)
Clorofila/metabolismo , Proteínas del Complejo del Centro de Reacción Fotosintética/metabolismo , Cationes/química , Clorofila/química , Clorofila/efectos de la radiación , Frío , Luz , Complejos de Proteína Captadores de Luz , Oxidación-Reducción , Oxígeno/metabolismo , Fotosíntesis , Proteínas del Complejo del Centro de Reacción Fotosintética/química , Proteínas del Complejo del Centro de Reacción Fotosintética/efectos de la radiación , Complejo de Proteína del Fotosistema II , Espectrometría de Fluorescencia , Spinacia oleracea
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