Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Indian J Med Res ; 146(Supplement): S8-S14, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29578189

RESUMEN

BACKGROUND & OBJECTIVES: Botulinum toxin is considered as an effective treatment for spasticity in children with cerebral palsy (CP). However, there are only a few long-term studies, and the effects on motor function have been inconclusive. Moreover, due to its high cost and need for intensive post-injection therapy, utility in context of developing nations has not been established. This retrospective study was undertaken to assess the long term effects of botulinum toxin-A with physical therapy in children with CP. METHODS: This retrospective study was conducted at a tertiary care centre in India, where a limited supply of botulinum toxin was introduced in the year 2009. It was used in a selective group of patients with CP along with intensive physical therapies. All children who received lower-limb botulinum injections over a 42-month period were analyzed. For evaluation of treatment effect, the measurement at 1st pre-injection assessment and the last measurements, i.e. 12 wk after last injection received by that child were compared. RESULTS: Twenty nine patients (20 males, median age 51 months) received 69 sessions of botulinum toxin injections in the lower limbs over a 42-month period. Thirteen patients were diplegic, 10 were quadriplegic, five were triplegic and one was hemiplegic. There was a significant improvement in pre- and post-injection scores on Observational Gait Scale (right side 7.1±3.6 to 10.7±3.7, left side 6.7±3.5 to 9.9±3.4), Gross Motor Function Measure Scale (47.9±17.7 to 67.6±17.2), Modified Ashworth Scale, passive range of motion and Gross Motor Function Classification System. Most of the patients showed gain in motor milestones as well. INTERPRETATION & CONCLUSIONS: Our results showed that judicious use of botulinum injections along with intensive physio/occupational therapies could yield good results in children with CP.


Asunto(s)
Toxinas Botulínicas Tipo A/administración & dosificación , Parálisis Cerebral/terapia , Modalidades de Fisioterapia , Preescolar , Terapia Combinada , Femenino , Humanos , Inyecciones , Extremidad Inferior , Masculino , Estudios Retrospectivos
2.
J Biomed Inform ; 55: 290-300, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25979153

RESUMEN

OBJECTIVE: This paper describes the University of Michigan's nine-year experience in developing and using a full-text search engine designed to facilitate information retrieval (IR) from narrative documents stored in electronic health records (EHRs). The system, called the Electronic Medical Record Search Engine (EMERSE), functions similar to Google but is equipped with special functionalities for handling challenges unique to retrieving information from medical text. MATERIALS AND METHODS: Key features that distinguish EMERSE from general-purpose search engines are discussed, with an emphasis on functions crucial to (1) improving medical IR performance and (2) assuring search quality and results consistency regardless of users' medical background, stage of training, or level of technical expertise. RESULTS: Since its initial deployment, EMERSE has been enthusiastically embraced by clinicians, administrators, and clinical and translational researchers. To date, the system has been used in supporting more than 750 research projects yielding 80 peer-reviewed publications. In several evaluation studies, EMERSE demonstrated very high levels of sensitivity and specificity in addition to greatly improved chart review efficiency. DISCUSSION: Increased availability of electronic data in healthcare does not automatically warrant increased availability of information. The success of EMERSE at our institution illustrates that free-text EHR search engines can be a valuable tool to help practitioners and researchers retrieve information from EHRs more effectively and efficiently, enabling critical tasks such as patient case synthesis and research data abstraction. CONCLUSION: EMERSE, available free of charge for academic use, represents a state-of-the-art medical IR tool with proven effectiveness and user acceptance.


Asunto(s)
Minería de Datos/métodos , Registros Electrónicos de Salud/organización & administración , Procesamiento de Lenguaje Natural , Motor de Búsqueda , Programas Informáticos , Uso Significativo , Michigan , Validación de Programas de Computación
3.
Nat Genet ; 38(9): 1049-54, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16936733

RESUMEN

In developed countries, age-related macular degeneration is a common cause of blindness in the elderly. A common polymorphism, encoding the sequence variation Y402H in complement factor H (CFH), has been strongly associated with disease susceptibility. Here, we examined 84 polymorphisms in and around CFH in 726 affected individuals (including 544 unrelated individuals) and 268 unrelated controls. In this sample, 20 of these polymorphisms showed stronger association with disease susceptibility than the Y402H variant. Further, no single polymorphism could account for the contribution of the CFH locus to disease susceptibility. Instead, multiple polymorphisms defined a set of four common haplotypes (of which two were associated with disease susceptibility and two seemed to be protective) and multiple rare haplotypes (associated with increased susceptibility in aggregate). Our results suggest that there are multiple disease susceptibility alleles in the region and that noncoding CFH variants play a role in disease susceptibility.


Asunto(s)
Factor H de Complemento/genética , Haplotipos , Degeneración Macular/genética , Anciano , Estudios de Casos y Controles , Susceptibilidad a Enfermedades , Frecuencia de los Genes , Humanos , Modelos Logísticos , Degeneración Macular/patología , Polimorfismo de Nucleótido Simple
4.
J Pediatr Rehabil Med ; 16(1): 115-124, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36373299

RESUMEN

PURPOSE: The incidence of dystonic cerebral palsy causing significant morbidity is on the rise. There is a paucity of evidence for the management of dystonia in children. METHODS: Forty-one children aged 6 months-5 years with predominantly dystonic cerebral palsy were started on a predetermined protocol of trihexyphenidyl (0.25-0.52 mg/kg) and followed up at 3, 6 and 12 weeks. Dystonia severity, motor function and developmental age at baseline and 12 weeks were compared using the Global Dystonia Scale (GDS), the Gross Motor Function Measure (GMFM), and Fine Motor/Perceptual Subscale of the Early Developmental Profile-2. Thirty-four children completed the entire 12 weeks of intervention. RESULTS: The mean age of participants was 25±11 months. A significant decrease in median total dystonia scores on the GDS was observed post-intervention (74.5 to 59, p < 0.0001), and 64% of participants gained motor milestones. GMFM scores increased significantly from a median of 19.8% pre-intervention to 26.5% post-intervention (p < 0.0001). There was improvement in the fine motor domain as compared to the baseline (p < 0.0001). The number of children classified at Gross Motor Function Classification System levels 1 and 2 increased to 47.05% from 5.88% in the pre-intervention group. CONCLUSION: Trihexyphenidyl significantly improved dystonia, motor function and development in children with dystonic cerebral palsy in this study. Additional studies are needed to clarify its role in larger numbers of children with this condition.


Asunto(s)
Parálisis Cerebral , Distonía , Trastornos Distónicos , Niño , Humanos , Preescolar , Lactante , Trihexifenidilo/uso terapéutico , Parálisis Cerebral/complicaciones , Distonía/tratamiento farmacológico , Distonía/etiología , Trastornos Distónicos/tratamiento farmacológico , Índice de Severidad de la Enfermedad , Destreza Motora
5.
Am J Hum Genet ; 84(6): 792-800, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19520207

RESUMEN

Retinitis pigmentosa (RP) refers to a genetically heterogeneous group of progressive neurodegenerative diseases that result in dysfunction and/or death of rod and cone photoreceptors in the retina. So far, 18 genes have been identified for autosomal-dominant (ad) RP. Here, we describe an adRP locus (RP42) at chromosome 7p15 through linkage analysis in a six-generation Scandinavian family and identify a disease-causing mutation, c.449G-->A (p.S150N), in exon 6 of the KLHL7 gene. Mutation screening of KLHL7 in 502 retinopathy probands has revealed three different missense mutations in six independent families. KLHL7 is widely expressed, including expression in rod photoreceptors, and encodes a 75 kDa protein of the BTB-Kelch subfamily within the BTB superfamily. BTB-Kelch proteins have been implicated in ubiquitination through Cullin E3 ligases. Notably, all three putative disease-causing KLHL7 mutations are within a conserved BACK domain; homology modeling suggests that mutant amino acid side chains can potentially fill the cleft between two helices, thereby affecting the ubiquitination complexes. Mutations in an identical region of another BTB-Kelch protein, gigaxonin, have previously been associated with giant axonal neuropathy. Our studies suggest an additional role of the ubiquitin-proteasome protein-degradation pathway in maintaining neuronal health and in disease.


Asunto(s)
Autoantígenos/genética , Genes Dominantes , Mutación Missense/genética , Polimorfismo de Nucleótido Simple/genética , Retinitis Pigmentosa/genética , Secuencia de Aminoácidos , Autoantígenos/metabolismo , Cromosomas Humanos Par 7/genética , Ensayo de Inmunoadsorción Enzimática , Perfilación de la Expresión Génica , Ligamiento Genético , Humanos , Immunoblotting , Datos de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Linaje , Retinitis Pigmentosa/metabolismo , Retinitis Pigmentosa/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido
6.
BMC Neurosci ; 13: 152, 2012 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-23241222

RESUMEN

BACKGROUND: The rd1 mouse retina is a well-studied model of retinal degeneration where rod photoreceptors undergo cell death beginning at postnatal day (P) 10 until P21. This period coincides with photoreceptor terminal differentiation in a normal retina. We have used the rd1 retina as a model to investigate early molecular defects in developing rod photoreceptors prior to the onset of degeneration. RESULTS: Using a microarray approach, we performed gene profiling comparing rd1 and wild type (wt) retinas at four time points starting at P2, prior to any obvious biochemical or morphological differences, and concluding at P8, prior to the initiation of cell death. Of the 143 identified differentially expressed genes, we focused on Rab acceptor 1 (Rabac1), which codes for the protein Prenylated rab acceptor 1 (PRA1) and plays an important role in vesicular trafficking. Quantitative RT-PCR analysis confirmed reduced expression of PRA1 in rd1 retina at all time points examined. Immunohistochemical observation showed that PRA1-like immunoreactivity (LIR) co-localized with the cis-Golgi marker GM-130 in the photoreceptor as the Golgi translocated from the perikarya to the inner segment during photoreceptor differentiation in wt retinas. Diffuse PRA1-LIR, distinct from the Golgi marker, was seen in the distal inner segment of wt photoreceptors starting at P8. Both plexiform layers contained PRA1 positive punctae independent of GM-130 staining during postnatal development. In the inner retina, PRA1-LIR also colocalized with the Golgi marker in the perinuclear region of most cells. A similar pattern was seen in the rd1 mouse inner retina. However, punctate and significantly reduced PRA1-LIR was present throughout the developing rd1 inner segment, consistent with delayed photoreceptor development and abnormalities in Golgi sorting and vesicular trafficking. CONCLUSIONS: We have identified genes that are differentially regulated in the rd1 retina at early time points, which may give insights into developmental defects that precede photoreceptor cell death. This is the first report of PRA1 expression in the retina. Our data support the hypothesis that PRA1 plays an important role in vesicular trafficking between the Golgi and cilia in differentiating and mature rod photoreceptors.


Asunto(s)
Proteínas de la Membrana/fisiología , Células Fotorreceptoras de Vertebrados/fisiología , Transporte de Proteínas/fisiología , Animales , Autoantígenos/metabolismo , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica/métodos , Regulación del Desarrollo de la Expresión Génica/genética , Regulación del Desarrollo de la Expresión Génica/fisiología , Aparato de Golgi/metabolismo , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Células Fotorreceptoras de Vertebrados/metabolismo , Transporte de Proteínas/genética , Retina/crecimiento & desarrollo , Retina/metabolismo , Degeneración Retiniana/genética , Degeneración Retiniana/metabolismo
7.
Bioinformatics ; 23(14): 1854-6, 2007 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-17488757

RESUMEN

UNLABELLED: The Madeline 2.0 Pedigree Drawing Engine (PDE) is a pedigree drawing program for use in linkage and family-based association studies. The program is designed to handle large and complex pedigrees with an emphasis on readability and aesthetics. For complex pedigrees, we use a hybrid algorithm in which consanguinous loops are drawn as cyclic graphs whenever possible, but we resort to acyclic graphs when matings can no longer be connected without line crossings. A similar hybrid approach is used to avoid line crossings for matings between distant descendants of different founding groups. Written in object-oriented C++ and released under the GNU General Public License (GPL), Madeline 2.0 PDE reads input files specified on the command line and generates pedigree drawings without user interaction. Pedigree output in scalable vector graphics (SVG) format can be viewed in browsers with native SVG rendering support or in vector graphics editors. We provide an easy-to-use public web service, which is experimental and still under development. AVAILABILITY: http://kellogg.umich.edu/madeline.


Asunto(s)
Biología Computacional/métodos , Linaje , Algoritmos , Gráficos por Computador , Computadores , Genética , Humanos , Internet , Lenguajes de Programación , Programas Informáticos , Interfaz Usuario-Computador
8.
Invest Ophthalmol Vis Sci ; 47(5): 1785-93, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16638982

RESUMEN

PURPOSE: PITX2 gene dose plays a central role in Axenfeld-Rieger syndrome. The purpose of this study was to test the hypothesis that the effects of Pitx2 gene dose on eye development can be molecularly dissected in available Pitx2 mutant mice. METHODS: A panel of mice with Pitx2 gene dose ranging from wild-type (+/+) to none (-/-) was generated. Eye morphogenesis was assessed in animals with each Pitx2 gene dose. We also compared global gene expression in eye primordia taken from e12.5 Pitx2+/+, Pitx2+/-, Pitx2-/- embryos using gene microarrays. The validity of microarray results was confirmed by qRT-PCR. RESULTS: Morphogenesis of all extraocular muscle bundles correlated highly with Pitx2 gene dose, but there were some differences in sensitivity among muscle groups. Superior and inferior oblique muscles were most sensitive and disappeared before the four rectus muscles. Expression of muscle-specific genes was globally sensitive to Pitx2 gene dose, including the muscle-specific transcription factor genes Myf5, Myog, Myod1, Smyd1, Msc, and Csrp3. CONCLUSIONS: Pitx2 gene dose regulates both morphogenesis and gene expression in developing extraocular muscles. The expression of key muscle-specific transcription factor genes is regulated by Pitx2 gene dose, suggesting that sufficient levels of PITX2 protein are essential for early initiation of the myogenic regulatory cascade in extraocular muscles. These results document the first ocular tissue affected by Pitx2 gene dose in a model organism, where the underlying mechanisms can be analyzed, and provide a paradigm for future experiments designed to elucidate additional effects of Pitx2 gene dose during eye development.


Asunto(s)
Dosificación de Gen , Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas de Homeodominio/genética , Morfogénesis/genética , Proteínas Nucleares/genética , Músculos Oculomotores/embriología , Animales , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Fluorescente , Proteínas Musculares/genética , Músculos Oculomotores/crecimiento & desarrollo , Embarazo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/genética , Proteína del Homeodomínio PITX2
9.
Sleep Med ; 4(4): 333-8, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-14592306

RESUMEN

OBJECTIVE: To compare efficacy, compliance rates, and side effects of a new strapless oral interface, the Oracle, with available nasal masks over 8 weeks of use for the treatment of obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: A total of 38 patients with OSAHS (respiratory disturbance index (RDI) >/=15/h) were enrolled after the diagnostic polysomnogram for subsequent continuous positive airway pressure (CPAP) therapy. After randomization, therapeutic pressures during a titration study were determined for 21 patients in the oral group and 17 patients in the nasal group. Comparisons for nasal and oral interfaces were made for baseline patient characteristics, average hours of CPAP use, side effects from therapy, and among questionnaires evaluating patients' subjective responses to therapy at months 1 and 2. RESULTS: No significant difference was observed in the average hours of CPAP use between the oral (4.5+/-2.1; 5.5+/-2.6) and nasal groups (4.0+/-2.6; 4.8+/-2.5) for either month 1 or 2 (P>0.05). The dropout rates were similar for both groups after 8 weeks of therapy. However, patients in the nasal group had higher occurrences of side effects such as nasal congestion, dryness, and air leaks, whereas patients in the oral group experienced more oral dryness and gum pain. CONCLUSION: Oral delivery of CPAP with the Oracle is an effective and suitable alternative for patients with OSAHS.


Asunto(s)
Presión de las Vías Aéreas Positiva Contínua/instrumentación , Síndromes de la Apnea del Sueño/terapia , Apnea Obstructiva del Sueño/terapia , Adulto , Presión de las Vías Aéreas Positiva Contínua/efectos adversos , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Boca , Cavidad Nasal , Estudios Prospectivos , Síndrome , Resultado del Tratamiento
10.
Hum Immunol ; 73(3): 214-22, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21889557

RESUMEN

Among peripheral regulatory T cells, CD8(+) T cells also play an important role in the maintenance of immune homeostasis. A subset of CD8(+) Treg that express αß T cell receptor (TCR) and CD8αα homodimers can recognize TCR-derived peptides in the context of the class Ib MHC molecule Qa-1. To gain a better understanding of the nature and phenotype of CD8αα(+)TCRαß+ Treg, a global gene expression profiling using microarray, real-time quantitative polymerase chain reaction, and flow-cytometric analysis was performed using functional Treg clones and lines. The study findings show that CD8(+) Treg shared gene profile expressed by innate-like lymphocytes, including murine intraepithelial lymphocytes and thymic CD8αα(+)TCRαß+ T-cell populations. In addition, this subset displays differential expression of several key regulatory molecules, including CD200. CD8αα(+) Treg expressed higher levels of a number of natural killer cell-related receptors and molecules belonging to the TNF superfamily. Collectively, peripheral class Ib-reactive CD8αα(+)TCRαß+ T cells represent a unique regulatory population different from class Ia major histocompatibility complex-restricted conventional T cells. These studies have important implications for the regulatory mechanisms mediated by the CD8(+) Treg population in general.


Asunto(s)
Antígenos CD/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Células Asesinas Naturales/metabolismo , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Linfocitos T Reguladores/metabolismo , Animales , Antígenos CD8/metabolismo , Línea Celular , Células Clonales , Perfilación de la Expresión Génica , Humanos , Inmunidad Innata , Inmunomodulación , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/patología , Ratones , Ratones Transgénicos , Análisis de Secuencia por Matrices de Oligonucleótidos , Tolerancia Periférica , Unión Proteica , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/patología
11.
PLoS One ; 5(11): e13885, 2010 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-21079736

RESUMEN

BACKGROUND: Advanced age contributes to clinical manifestations of many retinopathies and represents a major risk factor for age-related macular degeneration, a leading cause of visual impairment and blindness in the elderly. Rod photoreceptors are especially vulnerable to genetic defects and changes in microenvironment, and are among the first neurons to die in normal aging and in many retinal degenerative diseases. The molecular mechanisms underlying rod photoreceptor vulnerability and potential biomarkers of the aging process in this highly specialized cell type are unknown. METHODOLOGY/PRINCIPAL FINDINGS: To discover aging-associated adaptations that may influence rod function, we have generated gene expression profiles of purified rod photoreceptors from mouse retina at young adult to early stages of aging (1.5, 5, and 12 month old mice). We identified 375 genes that showed differential expression in rods from 5 and 12 month old mouse retina compared to that of 1.5 month old retina. Quantitative RT-PCR experiments validated expression change for a majority of the 25 genes that were examined. Macroanalysis of differentially expressed genes using gene class testing and protein interaction networks revealed overrepresentation of cellular pathways that are potentially photoreceptor-specific (angiogenesis and lipid/retinoid metabolism), in addition to age-related pathways previously described in several tissue types (oxidative phosphorylation, stress and immune response). CONCLUSIONS/SIGNIFICANCE: Our study suggests a progressive shift in cellular homeostasis that may underlie aging-associated functional decline in rod photoreceptors and contribute to a more permissive state for pathological processes involved in retinal diseases.


Asunto(s)
Envejecimiento , Perfilación de la Expresión Génica , Homeostasis/genética , Células Fotorreceptoras Retinianas Bastones/metabolismo , Animales , Análisis por Conglomerados , Regulación del Desarrollo de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Ratones , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos , Retina/crecimiento & desarrollo , Retina/metabolismo , Enfermedades de la Retina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo
12.
J Biol Chem ; 284(32): 21468-77, 2009 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-19506076

RESUMEN

RDH12 mutations are responsible for early-onset autosomal recessive retinal dystrophy, which results in profound retinal pathology and severe visual handicap in patients. To investigate the function of RDH12 within the network of retinoid dehydrogenases/reductases (RDHs) present in retina, we studied the retinal phenotype of Rdh12-deficient mice. In vivo rates of all-trans-retinal reduction and 11-cis-retinal formation during recovery from bleaching were similar in Rdh12-deficient and wild-type mice matched for an Rpe65 polymorphism that impacts visual cycle efficiency. However, retinal homogenates from Rdh12-deficient mice exhibited markedly decreased capacity to reduce exogenous retinaldehydes in vitro. Furthermore, in vivo levels of the bisretinoid compound diretinoid-pyridinium-ethanolamine (A2E) were increased in Rdh12-deficient mice of various genetic backgrounds. Conversely, in vivo levels of retinoic acid and total retinol were significantly decreased. Rdh12 transcript levels in wild-type mice homozygous for the Rpe65-Leu(450) polymorphism were greater than in Rpe65-Met(450) mice and increased during postnatal development in wild-type mice and Nrl-deficient mice having an all-cone retina. Rdh12-deficient mice did not exhibit increased retinal degeneration relative to wild-type mice at advanced ages, when bred on the light-sensitive BALB/c background, or when heterozygous for a null allele of superoxide dismutase 2 (Sod2(+/-)). Our findings suggest that a critical function of RDH12 is the reduction of all-trans-retinal that exceeds the reductive capacity of the photoreceptor outer segments.


Asunto(s)
Retinal-Deshidrogenasa/fisiología , Segmento Externo de las Células Fotorreceptoras Retinianas/metabolismo , Oxidorreductasas de Alcohol , Animales , Heterocigoto , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Modelos Biológicos , Fenotipo , Polimorfismo Genético , Retina/metabolismo , Retinal-Deshidrogenasa/genética , Retinal-Deshidrogenasa/metabolismo , Retinoides/metabolismo , Superóxido Dismutasa/genética
13.
Proc Natl Acad Sci U S A ; 104(41): 16227-32, 2007 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-17884985

RESUMEN

Genetic variants at chromosomes 1q31-32 and 10q26 are strongly associated with susceptibility to age-related macular degeneration (AMD), a common blinding disease of the elderly. We demonstrate, by evaluating 45 tag SNPs spanning HTRA1, PLEKHA1, and predicted gene LOC387715/ARMS2, that rs10490924 SNP alone, or a variant in strong linkage disequilibrium, can explain the bulk of association between the 10q26 chromosomal region and AMD. A previously suggested causal SNP, rs11200638, and other examined SNPs in the region are only indirectly associated with the disease. Contrary to previous reports, we show that rs11200638 SNP has no significant impact on HTRA1 promoter activity in three different cell lines, and HTRA1 mRNA expression exhibits no significant change between control and AMD retinas. However, SNP rs10490924 shows the strongest association with AMD (P = 5.3 x 10(-30)), revealing an estimated relative risk of 2.66 for GT heterozygotes and 7.05 for TT homozygotes. The rs10490924 SNP results in nonsynonymous A69S alteration in the predicted protein LOC387715/ARMS2, which has a highly conserved ortholog in chimpanzee, but not in other vertebrate sequences. We demonstrate that LOC387715/ARMS2 mRNA is detected in the human retina and various cell lines and encodes a 12-kDa protein, which localizes to the mitochondrial outer membrane when expressed in mammalian cells. We propose that rs10490924 represents a major susceptibility variant for AMD at 10q26. A likely biological mechanism is that the A69S change in the LOC387715/ARMS2 protein affects its presumptive function in mitochondria.


Asunto(s)
Degeneración Macular/genética , Proteínas Mitocondriales/genética , Proteínas/genética , Serina Endopeptidasas/genética , Anciano , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cromosomas Humanos Par 10/genética , Secuencia Conservada , Expresión Génica , Predisposición Genética a la Enfermedad , Variación Genética , Heterocigoto , Serina Peptidasa A1 que Requiere Temperaturas Altas , Homocigoto , Humanos , Desequilibrio de Ligamiento , Datos de Secuencia Molecular , Pan troglodytes/genética , Polimorfismo de Nucleótido Simple , ARN Mensajero/genética , Retina/metabolismo , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico
14.
Hum Mol Genet ; 15(17): 2588-602, 2006 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-16868010

RESUMEN

Rod and cone photoreceptors in mammalian retina are generated from common pool(s) of neuroepithelial progenitors. NRL, CRX and NR2E3 are key transcriptional regulators that control photoreceptor differentiation. Mutations in NR2E3, a rod-specific orphan nuclear receptor, lead to loss of rods, increased density of S-cones and supernormal S-cone-mediated vision in humans. To better understand its in vivo function, NR2E3 was expressed ectopically in the Nrl-/- retina, where post-mitotic precursors fated to be rods develop into functional S-cones similar to the human NR2E3 disease. Expression of NR2E3 in the Nrl-/- retina completely suppressed cone differentiation and resulted in morphologically rod-like photoreceptors, which were however not functional. Gene profiling of FACS-purified photoreceptors confirmed the role of NR2E3 as a strong suppressor of cone genes but an activator of only a subset of rod genes (including rhodopsin) in vivo. Ectopic expression of NR2E3 in cone precursors and differentiating S-cones of wild-type retina also generated rod-like cells. The dual regulatory function of NR2E3 was not dependent upon the presence of NRL and/or CRX, but on the timing and level of its expression. Our studies reveal a critical role of NR2E3 in establishing functional specificity of NRL-expressing photoreceptor precursors during retinal neurogenesis.


Asunto(s)
Precursores de Ácido Nucleico , Receptores Citoplasmáticos y Nucleares/genética , Retina/metabolismo , Células Fotorreceptoras Retinianas Conos/fisiología , Células Fotorreceptoras Retinianas Bastones/fisiología , Factores de Transcripción/genética , Animales , Diferenciación Celular , Citometría de Flujo , Regulación de la Expresión Génica , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/fisiología , Ratones , Ratones Transgénicos , Modelos Biológicos , Receptores Nucleares Huérfanos , Regiones Promotoras Genéticas , Receptores Citoplasmáticos y Nucleares/fisiología , Retina/citología , Células Fotorreceptoras Retinianas Conos/metabolismo , Células Fotorreceptoras Retinianas Bastones/metabolismo , Transactivadores/genética , Transactivadores/fisiología , Factores de Transcripción/fisiología , Visión Ocular
15.
Proc Natl Acad Sci U S A ; 103(10): 3890-5, 2006 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-16505381

RESUMEN

The Maf-family transcription factor Nrl is a key regulator of photoreceptor differentiation in mammals. Ablation of the Nrl gene in mice leads to functional cones at the expense of rods. We show that a 2.5-kb Nrl promoter segment directs the expression of enhanced GFP specifically to rod photoreceptors and the pineal gland of transgenic mice. GFP is detected shortly after terminal cell division, corresponding to the timing of rod genesis revealed by birthdating studies. In Nrl-/- retinas, the GFP+ photoreceptors express S-opsin, consistent with the transformation of rod precursors into cones. We report the gene profiles of freshly isolated flow-sorted GFP+ photoreceptors from wild-type and Nrl-/- retinas at five distinct developmental stages. Our results provide a framework for establishing gene regulatory networks that lead to mature functional photoreceptors from postmitotic precursors. Differentially expressed rod and cone genes are excellent candidates for retinopathies.


Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Proteínas del Ojo/genética , Células Fotorreceptoras Retinianas Bastones/metabolismo , Animales , Animales Recién Nacidos , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/deficiencia , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Diferenciación Celular , Proteínas de Unión al ADN/genética , Proteínas del Ojo/metabolismo , Perfilación de la Expresión Génica , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Ratones , Ratones Noqueados , Ratones Transgénicos , Neuronas/citología , Neuronas/metabolismo , Células Fotorreceptoras de Vertebrados/citología , Células Fotorreceptoras de Vertebrados/metabolismo , Regiones Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Retina/citología , Retina/crecimiento & desarrollo , Retina/metabolismo , Células Fotorreceptoras Retinianas Conos/citología , Células Fotorreceptoras Retinianas Conos/crecimiento & desarrollo , Células Fotorreceptoras Retinianas Conos/metabolismo , Células Fotorreceptoras Retinianas Bastones/citología , Células Fotorreceptoras Retinianas Bastones/crecimiento & desarrollo
16.
J Opt Soc Am A Opt Image Sci Vis ; 22(10): 2262-8, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16277295

RESUMEN

Thresholds were assessed for a speed discrimination task with a pair of luminance-defined drifting gratings. The design and results of a series of experiments dealing in general with speed discrimination are described. Results show that for a speed discrimination task using drifting gratings, simultaneous presentation of the pair of gratings (spatially separated) was preferred over sequential presentation (temporally separated) in order to minimize the effects of eye movements and tracking. An interstimulus interval of at least 1000 ms was necessary to prevent motion aftereffects on subsequently viewed stimuli. For the two reference speeds tested of 2 and 8 deg/s using identical spatial frequency or randomizing spatial frequency for the pair of gratings did not affect speed discrimination thresholds. Implementing a staircase method of estimating thresholds was preferred over the method of constant stimuli or the method of limits. The results of these experiments were used to define the methodology for an investigation of aging and motion perception. These results will be of interest and use to psychophysicists designing and implementing speed discrimination paradigms.


Asunto(s)
Adaptación Ocular/fisiología , Discriminación en Psicología/fisiología , Percepción de Movimiento/fisiología , Reconocimiento Visual de Modelos/fisiología , Estimulación Luminosa/métodos , Desempeño Psicomotor/fisiología , Pruebas de Visión/métodos , Adulto , Humanos , Psicofísica , Proyectos de Investigación , Umbral Sensorial/fisiología , Campos Visuales/fisiología
17.
J Opt Soc Am A Opt Image Sci Vis ; 22(10): 2269-80, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16277296

RESUMEN

We studied the effects of aging on a speed discrimination task using a pair of first-order drifting luminance gratings. Two reference speeds of 2 and 8 deg/s were presented at stimulus durations of 500 ms and 1000 ms. The choice of stimulus parameters, etc., was determined in preliminary experiments and described in Part I. Thresholds were estimated using a two-alternative-forced-choice staircase methodology. Data were collected from 16 younger subjects (mean age 24 years) and 17 older subjects (mean age 71 years). Results showed that thresholds for speed discrimination were higher for the older age group. This was especially true at stimulus duration of 500 ms for both slower and faster speeds. This could be attributed to differences in temporal integration of speed with age. Visual acuity and contrast sensitivity were not statistically observed to mediate age differences in the speed discrimination thresholds. Gender differences were observed in the older age group, with older women having higher thresholds.


Asunto(s)
Adaptación Ocular/fisiología , Envejecimiento/fisiología , Discriminación en Psicología/fisiología , Percepción de Movimiento/fisiología , Reconocimiento Visual de Modelos/fisiología , Estimulación Luminosa/métodos , Desempeño Psicomotor/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Psicofísica , Proyectos de Investigación , Umbral Sensorial/fisiología , Pruebas de Visión/métodos , Campos Visuales/fisiología
18.
Bioinformatics ; 21(21): 4014-20, 2005 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-16141248

RESUMEN

UNLABELLED: Many bioinformatics problems can be tackled from a fresh angle offered by the network perspective. Directly inspired by metabolic network structural studies, we propose an improved gene clustering approach for inferring gene signaling pathways from gene microarray data. Based on the construction of co-expression networks that consists of both significantly linear and non-linear gene associations together with controlled biological and statistical significance, our approach tends to group functionally related genes into tight clusters despite their expression dissimilarities. We illustrate our approach and compare it to the traditional clustering approaches on a yeast galactose metabolism dataset and a retinal gene expression dataset. Our approach greatly outperforms the traditional approach in rediscovering the relatively well known galactose metabolism pathway in yeast and in clustering genes of the photoreceptor differentiation pathway. AVAILABILITY: The clustering method has been implemented in an R package "GeneNT" that is freely available from: http://www.cran.org.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica/fisiología , Modelos Biológicos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Proteoma/metabolismo , Transducción de Señal/fisiología , Factores de Transcripción/metabolismo , Algoritmos , Análisis por Conglomerados , Simulación por Computador , Reconocimiento de Normas Patrones Automatizadas/métodos , Activación Transcripcional/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA