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1.
Indian J Med Res ; 146(Supplement): S8-S14, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29578189

RESUMO

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.


Assuntos
Toxinas Botulínicas Tipo A/administração & dosagem , Paralisia Cerebral/terapia , Modalidades de Fisioterapia , Pré-Escolar , Terapia Combinada , Feminino , Humanos , Injeções , Extremidade Inferior , Masculino , Estudos Retrospectivos
2.
J Biomed Inform ; 55: 290-300, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25979153

RESUMO

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.


Assuntos
Mineração de Dados/métodos , Registros Eletrônicos de Saúde/organização & administração , Processamento de Linguagem Natural , Ferramenta de Busca , Software , Uso Significativo , Michigan , Validação de Programas de Computador
3.
Nat Genet ; 38(9): 1049-54, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16936733

RESUMO

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.


Assuntos
Fator H do Complemento/genética , Haplótipos , Degeneração Macular/genética , Idoso , Estudos de Casos e Controles , Suscetibilidade a Doenças , Frequência do Gene , Humanos , Modelos Logísticos , Degeneração Macular/patologia , Polimorfismo de Nucleotídeo Único
4.
J Pediatr Rehabil Med ; 16(1): 115-124, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36373299

RESUMO

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.


Assuntos
Paralisia Cerebral , Distonia , Distúrbios Distônicos , Criança , Humanos , Pré-Escolar , Lactente , Triexifenidil/uso terapêutico , Paralisia Cerebral/complicações , Distonia/tratamento farmacológico , Distonia/etiologia , Distúrbios Distônicos/tratamento farmacológico , Índice de Gravidade de Doença , Destreza Motora
5.
Am J Hum Genet ; 84(6): 792-800, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19520207

RESUMO

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.


Assuntos
Autoantígenos/genética , Genes Dominantes , Mutação de Sentido Incorreto/genética , Polimorfismo de Nucleotídeo Único/genética , Retinose Pigmentar/genética , Sequência de Aminoácidos , Autoantígenos/metabolismo , Cromossomos Humanos Par 7/genética , Ensaio de Imunoadsorção Enzimática , Perfilação da Expressão Gênica , Ligação Genética , Humanos , Immunoblotting , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Linhagem , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
6.
BMC Neurosci ; 13: 152, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23241222

RESUMO

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.


Assuntos
Proteínas de Membrana/fisiologia , Células Fotorreceptoras de Vertebrados/fisiologia , Transporte Proteico/fisiologia , Animais , Autoantígenos/metabolismo , Modelos Animais de Doenças , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Complexo de Golgi/metabolismo , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Células Fotorreceptoras de Vertebrados/metabolismo , Transporte Proteico/genética , Retina/crescimento & desenvolvimento , Retina/metabolismo , Degeneração Retiniana/genética , Degeneração Retiniana/metabolismo
7.
Bioinformatics ; 23(14): 1854-6, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17488757

RESUMO

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.


Assuntos
Biologia Computacional/métodos , Linhagem , Algoritmos , Gráficos por Computador , Computadores , Genética , Humanos , Internet , Linguagens de Programação , Software , Interface Usuário-Computador
8.
Invest Ophthalmol Vis Sci ; 47(5): 1785-93, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16638982

RESUMO

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.


Assuntos
Dosagem de Genes , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas de Homeodomínio/genética , Morfogênese/genética , Proteínas Nucleares/genética , Músculos Oculomotores/embriologia , Animais , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Proteínas Musculares/genética , Músculos Oculomotores/crescimento & desenvolvimento , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Proteína Homeobox PITX2
9.
Sleep Med ; 4(4): 333-8, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-14592306

RESUMO

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.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas/instrumentação , Síndromes da Apneia do Sono/terapia , Apneia Obstrutiva do Sono/terapia , Adulto , Pressão Positiva Contínua nas Vias Aéreas/efeitos adversos , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Boca , Cavidade Nasal , Estudos Prospectivos , Síndrome , Resultado do Tratamento
10.
Hum Immunol ; 73(3): 214-22, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21889557

RESUMO

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.


Assuntos
Antígenos CD/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Células Matadoras Naturais/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Linfócitos T Reguladores/metabolismo , Animais , Antígenos CD8/metabolismo , Linhagem Celular , Células Clonais , Perfilação da Expressão Gênica , Humanos , Imunidade Inata , Imunomodulação , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/patologia , Camundongos , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Tolerância Periférica , Ligação Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia
11.
PLoS One ; 5(11): e13885, 2010 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-21079736

RESUMO

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.


Assuntos
Envelhecimento , Perfilação da Expressão Gênica , Homeostase/genética , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Animais , Análise por Conglomerados , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência com Séries de Oligonucleotídeos , Retina/crescimento & desenvolvimento , Retina/metabolismo , Doenças Retinianas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
12.
J Biol Chem ; 284(32): 21468-77, 2009 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-19506076

RESUMO

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.


Assuntos
Retinal Desidrogenase/fisiologia , Segmento Externo das Células Fotorreceptoras da Retina/metabolismo , Oxirredutases do Álcool , Animais , Heterozigoto , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , Fenótipo , Polimorfismo Genético , Retina/metabolismo , Retinal Desidrogenase/genética , Retinal Desidrogenase/metabolismo , Retinoides/metabolismo , Superóxido Dismutase/genética
13.
Proc Natl Acad Sci U S A ; 104(41): 16227-32, 2007 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-17884985

RESUMO

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.


Assuntos
Degeneração Macular/genética , Proteínas Mitocondriais/genética , Proteínas/genética , Serina Endopeptidases/genética , Idoso , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromossomos Humanos Par 10/genética , Sequência Conservada , Expressão Gênica , Predisposição Genética para Doença , Variação Genética , Heterozigoto , Serina Peptidase 1 de Requerimento de Alta Temperatura A , Homozigoto , Humanos , Desequilíbrio de Ligação , Dados de Sequência Molecular , Pan troglodytes/genética , Polimorfismo de Nucleotídeo Único , RNA Mensageiro/genética , Retina/metabolismo , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
14.
Hum Mol Genet ; 15(17): 2588-602, 2006 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-16868010

RESUMO

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.


Assuntos
Precursores de Ácido Nucleico , Receptores Citoplasmáticos e Nucleares/genética , Retina/metabolismo , Células Fotorreceptoras Retinianas Cones/fisiologia , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Fatores de Transcrição/genética , Animais , Diferenciação Celular , Citometria de Fluxo , Regulação da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/fisiologia , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Receptores Nucleares Órfãos , Regiões Promotoras Genéticas , Receptores Citoplasmáticos e Nucleares/fisiologia , Retina/citologia , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Transativadores/genética , Transativadores/fisiologia , Fatores de Transcrição/fisiologia , Visão Ocular
15.
Proc Natl Acad Sci U S A ; 103(10): 3890-5, 2006 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-16505381

RESUMO

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.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/genética , Proteínas do Olho/genética , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Animais , Animais Recém-Nascidos , Fatores de Transcrição de Zíper de Leucina Básica/deficiência , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Diferenciação Celular , Proteínas de Ligação a DNA/genética , Proteínas do Olho/metabolismo , Perfilação da Expressão Gênica , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Neurônios/citologia , Neurônios/metabolismo , Células Fotorreceptoras de Vertebrados/citologia , Células Fotorreceptoras de Vertebrados/metabolismo , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Retina/citologia , Retina/crescimento & desenvolvimento , Retina/metabolismo , Células Fotorreceptoras Retinianas Cones/citologia , Células Fotorreceptoras Retinianas Cones/crescimento & desenvolvimento , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/citologia , Células Fotorreceptoras Retinianas Bastonetes/crescimento & desenvolvimento
16.
J Opt Soc Am A Opt Image Sci Vis ; 22(10): 2262-8, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16277295

RESUMO

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.


Assuntos
Adaptação Ocular/fisiologia , Discriminação Psicológica/fisiologia , Percepção de Movimento/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Testes Visuais/métodos , Adulto , Humanos , Psicofísica , Projetos de Pesquisa , Limiar Sensorial/fisiologia , Campos Visuais/fisiologia
17.
J Opt Soc Am A Opt Image Sci Vis ; 22(10): 2269-80, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16277296

RESUMO

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.


Assuntos
Adaptação Ocular/fisiologia , Envelhecimento/fisiologia , Discriminação Psicológica/fisiologia , Percepção de Movimento/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Psicofísica , Projetos de Pesquisa , Limiar Sensorial/fisiologia , Testes Visuais/métodos , Campos Visuais/fisiologia
18.
Bioinformatics ; 21(21): 4014-20, 2005 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-16141248

RESUMO

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.


Assuntos
Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/fisiologia , Modelos Biológicos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proteoma/metabolismo , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo , Algoritmos , Análise por Conglomerados , Simulação por Computador , Reconhecimento Automatizado de Padrão/métodos , Ativação Transcricional/fisiologia
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