Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Immunity ; 29(1): 150-64, 2008 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-18631455

RESUMO

The analysis of patient blood transcriptional profiles offers a means to investigate the immunological mechanisms relevant to human diseases on a genome-wide scale. In addition, such studies provide a basis for the discovery of clinically relevant biomarker signatures. We designed a strategy for microarray analysis that is based on the identification of transcriptional modules formed by genes coordinately expressed in multiple disease data sets. Mapping changes in gene expression at the module level generated disease-specific transcriptional fingerprints that provide a stable framework for the visualization and functional interpretation of microarray data. These transcriptional modules were used as a basis for the selection of biomarkers and the development of a multivariate transcriptional indicator of disease progression in patients with systemic lupus erythematosus. Thus, this work describes the implementation and application of a methodology designed to support systems-scale analysis of the human immune system in translational research settings.


Assuntos
Perfilação da Expressão Gênica/métodos , Genômica/métodos , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Adolescente , Criança , Biologia Computacional/métodos , Progressão da Doença , Feminino , Humanos , Masculino
2.
J Biomed Inform ; 52: 78-91, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24239612

RESUMO

To date, the scientific process for generating, interpreting, and applying knowledge has received less informatics attention than operational processes for conducting clinical studies. The activities of these scientific processes - the science of clinical research - are centered on the study protocol, which is the abstract representation of the scientific design of a clinical study. The Ontology of Clinical Research (OCRe) is an OWL 2 model of the entities and relationships of study design protocols for the purpose of computationally supporting the design and analysis of human studies. OCRe's modeling is independent of any specific study design or clinical domain. It includes a study design typology and a specialized module called ERGO Annotation for capturing the meaning of eligibility criteria. In this paper, we describe the key informatics use cases of each phase of a study's scientific lifecycle, present OCRe and the principles behind its modeling, and describe applications of OCRe and associated technologies to a range of clinical research use cases. OCRe captures the central semantics that underlies the scientific processes of clinical research and can serve as an informatics foundation for supporting the entire range of knowledge activities that constitute the science of clinical research.


Assuntos
Ontologias Biológicas , Pesquisa Biomédica , Informática Médica , Biologia Computacional , Medicina Baseada em Evidências , Humanos , Modelos Teóricos
3.
Cureus ; 14(11): e31160, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36349072

RESUMO

Alpha-cyclodextrin (αCD) is a bacterial product that is widely used as a food ingredient. In the European Union (EU), αCD is regulated as a dietary fiber with an authorized health claim "for contributing to the reduction of postprandial glycemic responses." In the US, αCD is generally recognized as save (GRAS), but on April 25, 2022, the U.S. Food and Drug Administration (FDA) rejected the inclusion of αCD in the list of dietary fibers because "the strength of the scientific evidence does not support a finding of a beneficial effect of αCD on postprandial blood glucose …" To evaluate the strength of this scientific evidence, this meta-analysis reviews clinical trials conducted to test the effect of αCD on the rise of blood glucose and insulin levels during three hours after consumption of a meal comprising carbohydrates, fats, and proteins. Several issues related to the standardization of the outcomes, the choice of the statistical methods in the cross-over studies conducted, and the choice of methods for the aggregation of P-values are discussed. It is concluded that the administration of αCD not only reduces the postprandial glycemic responses, but the absence of an increase in insulin levels suggests that αCD acts independently of increasing insulin production and, thus, the beneficial effect of αCD is not affected by insulin resistance.

4.
Cureus ; 14(9): e29146, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36259001

RESUMO

About a month after the COVID-19 epidemic peaked in Mainland China and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) migrated to Europe and then the USA, the epidemiological data began to provide important insights into the risks associated with the disease and the effectiveness of intervention strategies such as travel restrictions and lockdowns ("social distancing"). Respiratory diseases, including the 2003 severe acute respiratory syndrome (SARS) epidemic, remain only about two months in any given population, although peak incidence and lethality can vary. The epidemiological data suggested that at least two strains of SARS-CoV-2 had evolved during the first months of the epidemic while the virus migrated from Mainland China to Europe. South Korea (SK), Iran, Italy (IT), and Italy's neighbors were then hit by the more dangerous "SKII" variant. While the first epidemic in continental Asia was about to end and in Europe about to level off, the more recent epidemic in the younger US population was still increasing, albeit not exponentially anymore. The same models that help us to understand the epidemic also help us to choose prevention strategies. The containment of high-risk people, such as the elderly with comorbidities, and reducing disease severity, by either vaccination, reduction of comorbidities (seen as risk factors already in Italy), or early treatment of complications, are the best strategies against a respiratory virus disease (RVD). Lockdowns can be effective during the month following the peak incidence of infections when the exponential increase of cases ends (the window of opportunity). From the standard susceptible-infectious-resistant (SIR) model used, containing low-risk people too early, instead, merely prolongs the time the virus needs to circulate until the incidence is high enough to reach "herd immunity." Containing low-risk people too late is also not helpful, unless to prevent a rebound if containment started too early.

5.
J Nutr ; 141(2): 207-13, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21178084

RESUMO

Fish oils containing both EPA and DHA have been shown to have beneficial cardiovascular effects, but less is known about the independent effects of DHA. This study was designed to examine the effects of DHA on plasma lipid and lipoprotein concentrations and other biomarkers of cardiovascular risk in the absence of weight loss. In this randomized, controlled, double-blind trial, 36 overweight or obese adults were treated with 2 g/d of algal DHA or placebo for 4.5 mo. Markers of cardiovascular risk were assessed before and after treatment. In the DHA-supplemented group, the decrease in mean VLDL particle size (P ≤ 0.001) and increases in mean LDL (P ≤ 0.001) and HDL (P ≤ 0.001) particle sizes were significantly greater than changes in the placebo group. DHA supplementation also increased the concentrations of large LDL (P ≤ 0.001) and large HDL particles (P = 0.001) and decreased the concentrations of small LDL (P = 0.009) and medium HDL particles (P = 0.001). As calculated using NMR-derived data, DHA supplementation reduced VLDL TG (P = 0.009) and total TG concentrations (P = 0.006). Plasma IL-10 increased with DHA supplementation to a greater extent than placebo (P = 0.021), but no other significant changes were observed in glucose metabolism, insulin sensitivity, blood pressure, or markers of inflammation with DHA. In summary, DHA supplementation resulted in potentially beneficial changes in some markers of cardiometabolic risk, whereas other markers were unchanged.


Assuntos
Doenças Cardiovasculares/sangue , Gorduras na Dieta/administração & dosagem , Ácidos Docosa-Hexaenoicos/farmacologia , Lipoproteínas/sangue , Obesidade/sangue , Extratos Vegetais/farmacologia , Rodófitas/química , Adulto , Doenças Cardiovasculares/prevenção & controle , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Interleucina-10/sangue , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Obesidade/tratamento farmacológico , Tamanho da Partícula , Extratos Vegetais/uso terapêutico , Fatores de Risco , Triglicerídeos/sangue , Adulto Jovem
6.
Int Arch Allergy Immunol ; 156(2): 205-11, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21597301

RESUMO

BACKGROUND: Insect venoms contain an allergen hyaluronidase that catalyzes the hydrolysis of hyaluronan (HA), a polymer of disaccharide GlcUA-GlcNAc in skin. HAs depending on their size have variable function in inflammation and immunity. This paper reports on whether hyaluronidase, HA polymers and oligomers can promote antibody response in mice. METHODS: HA oligomers (8- to 50-mer; 3-20 kDa) were obtained by bee venom hyaluronidase digestion of HA polymers (750- to 5,000-mer; 300-2,000 kDa). Antibody responses in mice were compared following 3 biweekly subcutaneous injection of ovalbumin (OVA) with or without test adjuvant. RESULTS: OVA-specific IgG1 levels were approximately 2 times higher in BALB/c and C3H/HeJ mice receiving OVA and HA oligomer or polymer than those treated with OVA alone, and no increase in total IgE level was observed. In C57Bl/6 mice, observed increases in IgG1 and IgE were 3.5- and 1.7-fold, respectively, for the oligomer and 16- and 5-fold (p < 0.05), respectively, for the polymer. CONCLUSION: Hyaluronidase by its action on HA in skin can function indirectly as adjuvant to promote IgE and IgG1 response in mice. Insect venoms also have cytolytic peptides and phospholipases with inflammatory roles. These activities found in mice may contribute to venom allergenicity in susceptible people.


Assuntos
Venenos de Abelha/imunologia , Abelhas/imunologia , Ácido Hialurônico/imunologia , Hialuronoglucosaminidase/imunologia , Hipersensibilidade/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Venenos de Abelha/enzimologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Polímeros/farmacologia
7.
Stat Med ; 30(23): 2767-77, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21284015

RESUMO

Increasing demands for evidence-based medicine and for the translation of biomedical research into individual and public health benefit have been accompanied by the proliferation of special units that offer expertise in biostatistics, epidemiology, and research design (BERD) within academic health centers. Objective metrics that can be used to evaluate, track, and improve the performance of these BERD units are critical to their successful establishment and sustainable future. To develop a set of reliable but versatile metrics that can be adapted easily to different environments and evolving needs, we consulted with members of BERD units from the consortium of academic health centers funded by the Clinical and Translational Science Award Program of the National Institutes of Health. Through a systematic process of consensus building and document drafting, we formulated metrics that covered the three identified domains of BERD practices: the development and maintenance of collaborations with clinical and translational science investigators, the application of BERD-related methods to clinical and translational research, and the discovery of novel BERD-related methodologies. In this article, we describe the set of metrics and advocate their use for evaluating BERD practices. The routine application, comparison of findings across diverse BERD units, and ongoing refinement of the metrics will identify trends, facilitate meaningful changes, and ultimately enhance the contribution of BERD activities to biomedical research.


Assuntos
Bioestatística/métodos , Métodos Epidemiológicos , Projetos de Pesquisa/normas , Estudos de Avaliação como Assunto , Humanos , Estados Unidos
8.
J Exp Med ; 199(11): 1503-11, 2004 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-15173207

RESUMO

Cancer vaccines aim at inducing (a) tumor-specific effector T cells able to reduce/eliminate the tumor mass, and (b) long-lasting tumor-specific memory T cells able to control tumor relapse. We have shown earlier, in 18 human histocompatibility leukocyte antigen (HLA)-A*0201 patients with metastatic melanoma, that vaccination with peptide-loaded CD34-dendritic cells (DCs) leads to expansion of melanoma-specific interferon gamma-producing CD8+ T cells in the blood. Here, we show in 9 out of 12 analyzed patients the expansion of cytolytic CD8+ T cell precursors specific for melanoma differentiation antigens. These precursors yield, upon single restimulation with melanoma peptide-pulsed DCs, cytotoxic T lymphocytes (CTLs) able to kill melanoma cells. Melanoma-specific CTLs can be grown in vitro and can be detected in three assays: (a) melanoma tetramer binding, (b) killing of melanoma peptide-pulsed T2 cells, and (c) killing of HLA-A*0201 melanoma cells. The cytolytic activity of expanded CTLs correlates with the frequency of melanoma tetramer binding CD8+ T cells. Thus, CD34-DC vaccines can expand melanoma-specific CTL precursors that can kill melanoma antigen-expressing targets. These results justify the design of larger follow-up studies to assess the immunological and clinical response to peptide-pulsed CD34-DC vaccines.


Assuntos
Antígenos CD34/análise , Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Células-Tronco Hematopoéticas/imunologia , Melanoma/terapia , Linfócitos T Citotóxicos/imunologia , Citotoxicidade Imunológica , Humanos , Melanoma/imunologia , Melanoma/secundário , Vacinação
9.
BMC Med Genet ; 10: 10, 2009 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-19193207

RESUMO

BACKGROUND: Multiple sclerosis (MS) is a complex trait in which genes in the MHC class II region exert the single strongest effect on genetic susceptibility. The principal MHC class II haplotype that increases MS risk in individuals of Northern European descent are those that bear HLA-DRB1*15. However, several other HLA-DRB1 alleles have been positively and negatively associated with MS and each of the main allelotypes is composed of many sub-allelotypes with slightly different sequence composition. Given the role of this locus in antigen presentation it has been suggested that variations in the peptide binding site of the allele may underlie allelic variation in disease risk. METHODS: In an investigation of 7,333 individuals from 1,352 MS families, we assessed the nucleotide sequence of HLA-DRB1 for any effects on disease susceptibility extending a recently published method of statistical analysis for family-based association studies to the particular challenges of hyper-variable genetic regions. RESULTS: We found that amino acid 60 of the HLA-DRB1 peptide sequence, which had previously been postulated based on structural features, is unlikely to play a major role. Instead, empirical evidence based on sequence information suggests that MS susceptibility arises primarily from amino acid 13. CONCLUSION: Identifying a single amino acid as a major risk factor provides major practical implications for risk and for the exploration of mechanisms, although the mechanism of amino acid 13 in the HLA-DRB1 sequence's involvement in MS as well as the identity of additional variants on MHC haplotypes that influence risk need to be uncovered.


Assuntos
Predisposição Genética para Doença , Antígenos HLA-DR/genética , Modelos Estatísticos , Esclerose Múltipla/genética , Adulto , Alelos , Criança , Genótipo , Cadeias HLA-DRB1 , Humanos , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Análise de Sequência de Proteína
10.
J Pediatr ; 155(4): 572-7, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19595365

RESUMO

OBJECTIVES: To test the hypothesis that long-term survivors of low-risk Kawasaki disease (KD) have ongoing vascular inflammation and dysfunction and a higher risk of accelerated atherosclerosis than healthy control subjects. STUDY DESIGN: Twenty-eight patients with KD (7-20 years after acute illness) and 27 age-matched healthy control subjects were examined for medical and dietary history, serum markers of atherosclerotic risk and inflammation, carotid intimal-medial thickness (CIMT) with vascular ultrasound scanning and arterial stiffness with applanation tonometry. RESULTS: Patients and control subjects were similar in age, sex, body mass index, waist-to-hip ratio, blood pressure, cigarette smoking, family history, diet, high-density lipoprotein cholesterol level, lipoprotein (a) level, homocysteine level, glucose level, insulin level, CIMT, arterial stiffness, C-reactive protein level, and inflammatory cytokine level. Levels of total cholesterol and apolipoprotein B were significantly higher in patients with KD than in control subjects. CONCLUSIONS: There was no evidence of increased atherosclerosis. Small but significant differences in cholesterol and apolipoprotein B levels could suggest increased future risk for atherosclerosis and warrant further study.


Assuntos
Aterosclerose/epidemiologia , Síndrome de Linfonodos Mucocutâneos/metabolismo , Síndrome de Linfonodos Mucocutâneos/patologia , Proteínas de Fase Aguda/metabolismo , Adolescente , Adulto , Aterosclerose/diagnóstico , Biomarcadores/metabolismo , Artérias Carótidas/patologia , Estudos de Casos e Controles , Citocinas/sangue , Feminino , Humanos , Mediadores da Inflamação/sangue , Lipídeos/sangue , Masculino , Síndrome de Linfonodos Mucocutâneos/complicações , Fatores de Risco , Adulto Jovem
11.
Stat Appl Genet Mol Biol ; 7(1): Article 19, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18597665

RESUMO

As the field of genomics matures, more complex genotypes and phenotypes are being studied. Fanconi anemia (FA), for example, is an inherited chromosome instability syndrome with a complex array of variable disease phenotypes including congenital malformations, hematological manifestations, and cancer. To better understand specific aspects of the genetic etiology of FA and other rare diseases with complex phenotypes, it is often necessary to reduce the dimensions of the disease phenotype information. Towards this end, we extend a novel non-parametric approach to include information about a hierarchical structure among disease phenotypes. The proposed extension increases information content of the phenotype scores obtained and, thereby, the power of genotype-phenotype relationships studies.


Assuntos
Doenças Genéticas Inatas/genética , Modelos Genéticos , Anemia de Fanconi/genética , Genótipo , Humanos , Análise Multivariada , Fenótipo
12.
PLoS One ; 14(3): e0214826, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30921433

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0199012.].

13.
PLoS One ; 13(7): e0199012, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29965997

RESUMO

Most breast cancer deaths are caused by metastasis and treatment options beyond radiation and cytotoxic drugs, which have severe side effects, and hormonal treatments, which are or become ineffective for many patients, are urgently needed. This study reanalyzed existing data from three genome-wide association studies (GWAS) using a novel computational biostatistics approach (muGWAS), which had been validated in studies of 600-2000 subjects in epilepsy and autism. MuGWAS jointly analyzes several neighboring single nucleotide polymorphisms while incorporating knowledge about genetics of heritable diseases into the statistical method and about GWAS into the rules for determining adaptive genome-wide significance. Results from three independent GWAS of 1000-2000 subjects each, which were made available under the National Institute of Health's "Up For A Challenge" (U4C) project, not only confirmed cell-cycle control and receptor/AKT signaling, but, for the first time in breast cancer GWAS, also consistently identified many genes involved in endo-/exocytosis (EEC), most of which had already been observed in functional and expression studies of breast cancer. In particular, the findings include genes that translocate (ATP8A1, ATP8B1, ANO4, ABCA1) and metabolize (AGPAT3, AGPAT4, DGKQ, LPPR1) phospholipids entering the phosphatidylinositol cycle, which controls EEC. These novel findings suggest scavenging phospholipids as a novel intervention to control local spread of cancer, packaging of exosomes (which prepare distant microenvironment for organ-specific metastases), and endocytosis of ß1 integrins (which are required for spread of metastatic phenotype and mesenchymal migration of tumor cells). Beta-cyclodextrins (ßCD) have already been shown to be effective in in vitro and animal studies of breast cancer, but exhibits cholesterol-related ototoxicity. The smaller alpha-cyclodextrins (αCD) also scavenges phospholipids, but cannot fit cholesterol. An in-vitro study presented here confirms hydroxypropyl (HP)-αCD to be twice as effective as HPßCD against migration of human cells of both receptor negative and estrogen-receptor positive breast cancer. If the previous successful animal studies with ßCDs are replicated with the safer and more effective αCDs, clinical trials of adjuvant treatment with αCDs are warranted. Ultimately, all breast cancer are expected to benefit from treatment with HPαCD, but women with triple-negative breast cancer (TNBC) will benefit most, because they have fewer treatment options and their cancer advances more aggressively.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Endocitose/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , alfa-Ciclodextrinas/administração & dosagem , 2-Hidroxipropil-beta-Ciclodextrina/uso terapêutico , Transportador 1 de Cassete de Ligação de ATP/genética , Aciltransferases/genética , Adenosina Trifosfatases/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Estudo de Associação Genômica Ampla , Humanos , Proteínas de Transferência de Fosfolipídeos/genética , Monoéster Fosfórico Hidrolases/genética , Polimorfismo de Nucleotídeo Único/genética , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , alfa-Ciclodextrinas/metabolismo
14.
J Transl Med ; 5: 27, 2007 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-17555598

RESUMO

BACKGROUND: Alefacept (anti-CD2) biological therapy selectively targets effector memory T cells (Tem) in psoriasis vulgaris, a model Type 1 autoimmune disease. METHODS: Circulating leukocytes were phenotyped in patients receiving alefacept for moderate to severe psoriasis. RESULTS: In all patients, this treatment caused a preferential decrease in effector memory T cells (CCR7- CD45RA-) (mean 63% reduction) for both CD4+ and CD8+ Tem, while central memory T cells (Tcm) (CCR7+CD45RA-) were less affected, and naïve T cells (CCR7+CD45RA+) were relatively spared. Circulating CD8+ effector T cells and Type 1 T cells (IFN-gamma-producing) were also significantly reduced. CONCLUSION: Alefacept causes a selective reduction in circulating effector memory T cells (Tem) and relative preservation of central memory T cells (Tcm) in psoriasis.


Assuntos
Antígenos CD2/imunologia , Movimento Celular , Memória Imunológica , Psoríase/tratamento farmacológico , Psoríase/imunologia , Proteínas Recombinantes de Fusão/uso terapêutico , Linfócitos T/imunologia , Adulto , Idoso , Alefacept , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Movimento Celular/efeitos dos fármacos , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/uso terapêutico , Feminino , Humanos , Memória Imunológica/efeitos dos fármacos , Lectinas Tipo C , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/patologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Psoríase/patologia , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/farmacologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/patologia
15.
AJR Am J Roentgenol ; 189(6): 1474-83, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18029888

RESUMO

OBJECTIVE: The purpose of this study was to assess the diagnostic value of hepatocellular nodule vascularity after microbubble injection for characterization of malignancy in patients with cirrhosis of the liver. MATERIALS AND METHODS: After sulfur hexafluoride-filled microbubble injection, the vascularity of 236 hepatocellular nodules (1-5 cm in diameter) in 215 patients with cirrhosis (151 men, 64 women; mean age, 62 +/- 11 [SD] years) was evaluated by consensus of three reference radiologists. The relation between nodule vascularity in the arterial (10-40 seconds from injection) and portal venous (45 seconds to microbubble disappearance) phases and dimension of malignancy was evaluated by multivariate U statistical analysis. Two blinded independent reviewers using reference criteria classified nodules as benign or malignant after review of unenhanced and contrast-enhanced sonograms. RESULTS: The final diagnoses were 96 malignant (84 hepatocellular carcinoma, 12 tumors not hepatocellular carcinoma) and 140 benign nodules (57 regenerative and 13 dysplastic nodules, 70 other benign lesions). Nodule hypervascularity during the arterial phase and hypovascularity during the portal venous phase (odds ratio, 27.78) and nodule diameter greater than 2 cm combined with hypervascularity during the arterial phase and isovascularity or hypervascularity during the portal venous phase (odds ratio, 3.3) were related to the presence of malignancy. Contrast-enhanced sonography improved diagnostic accuracy (unenhanced sonography vs contrast-enhanced sonography, 32% vs 71% for reviewer 1 and 22% vs 66% for reviewer 2; p < 0.05, McNemar test) even though hypervascular nodules 2 cm or smaller (malignant, n = 2; benign, n = 40) that appeared isovascular or hypervascular during the portal venous phase were misclassified. CONCLUSION: Assessment of hepatocellular nodule vascularity after microbubble injection allowed characterization of malignancy, but characterization was limited for hypervascular nodules 2 cm or less in diameter.


Assuntos
Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem , Neovascularização Patológica/diagnóstico por imagem , Carcinoma Hepatocelular/complicações , Meios de Contraste , Feminino , Humanos , Injeções Intralesionais , Cirrose Hepática/complicações , Masculino , Microbolhas , Pessoa de Meia-Idade , Radiografia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
BMC Bioinformatics ; 6: 65, 2005 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-15784152

RESUMO

BACKGROUND: Microscopists are familiar with many blemishes that fluorescence images can have due to dust and debris, glass flaws, uneven distribution of fluids or surface coatings, etc. Microarray scans show similar artefacts, which affect the analysis, particularly when one tries to detect subtle changes. However, most blemishes are hard to find by the unaided eye, particularly in high-density oligonucleotide arrays (HDONAs). RESULTS: We present a method that harnesses the statistical power provided by having several HDONAs available, which are obtained under similar conditions except for the experimental factor. This method "harshlights" blemishes and renders them evident. We find empirically that about 25% of our chips are blemished, and we analyze the impact of masking them on screening for differentially expressed genes. CONCLUSION: Experiments attempting to assess subtle expression changes should be carefully screened for blemishes on the chips. The proposed method provides investigators with a novel robust approach to improve the sensitivity of microarray analyses. By utilizing topological information to identify and mask blemishes prior to model based analyses, the method prevents artefacts from confounding the process of background correction, normalization, and summarization.


Assuntos
Biologia Computacional/métodos , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Algoritmos , Artefatos , Simulação por Computador , Interpretação Estatística de Dados , Perfilação da Expressão Gênica , Humanos , Análise em Microsséries , Microscopia de Fluorescência/métodos , Modelos Genéticos , Modelos Estatísticos , Análise Multivariada , Hibridização de Ácido Nucleico , Análise de Componente Principal , Psoríase/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
BMC Bioinformatics ; 6: 294, 2005 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-16336691

RESUMO

BACKGROUND: Microscopists are familiar with many blemishes that fluorescence images can have due to dust and debris, glass flaws, uneven distribution of fluids or surface coatings, etc. Microarray scans do show similar artifacts, which might affect subsequent analysis. Although all but the starkest blemishes are hard to find by the unaided eye, particularly in high-density oligonucleotide arrays (HDONAs), few tools are available to help with the detection of those defects. RESULTS: We develop a novel tool, Harshlight, for the automatic detection and masking of blemishes in HDONA microarray chips. Harshlight uses a combination of statistic and image processing methods to identify three different types of defects: localized blemishes affecting a few probes, diffuse defects affecting larger areas, and extended defects which may invalidate an entire chip. CONCLUSION: We demonstrate the use of Harshlight can materially improve analysis of HDONA chips, especially for experiments with subtle changes between samples. For the widely used MAS5 algorithm, we show that compact blemishes cause an average of 8 gene expression values per chip to change by more than 50%, two of them by more than twofold; our masking algorithm restores about two thirds of this damage. Large-scale artifacts are successfully detected and eliminated.


Assuntos
Biologia Computacional/métodos , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Software , Algoritmos , Artefatos , Automação , Análise por Conglomerados , Perfilação da Expressão Gênica , Humanos , Processamento de Imagem Assistida por Computador , Modelos Estatísticos , Sondas de Oligonucleotídeos/química , Oligonucleotídeos/química
18.
Arterioscler Thromb Vasc Biol ; 23(1): 117-22, 2003 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-12524234

RESUMO

OBJECTIVE: Atherosclerosis susceptibility is a genetic trait that varies between mouse strains. The goal of this study was to use a public mouse single nucleotide polymorphism (SNP) database to define the genetic loci that are associated with this trait, without the need to perform strain intercrosses that are normally required to obtain these loci. METHODS AND RESULTS: Apolipoprotein E (apoE)-deficient mice on 6 inbred genetic backgrounds were compared for atherosclerosis lesion size in the aortic root in 2 independent studies. After normalization to the C57BL/6 strain that was used in both studies, lesion areas were found in the following rank order: DBA/2J>C57BL/6>129/SV-ter>AKR/J approximately BALB/cByJ approximately C3H/HeJ. The log lesion difference in phenotypes between each of the 15 heterologous strain pairs was determined. A mouse SNP database was then used to calculate the genetic differences between the 15 strain pairs in partially overlapping 30-cM bins across the mouse genome. Correlation analyses were preformed to analyze the genetic and phenotypic differences among the strain pairs for each genetic region. The genetic regions with the highest correlations define the in silico quantitative trait loci (QTL) associated with the atherosclerosis phenotype. Five in silico atherosclerosis QTL were identified on chromosomes 1, 10, 14, 15, and 18. The loci on chromosomes 1, 10, 14, and 18 overlap with suggestive atherosclerosis QTL identified through analyses of an F(2) cohort derived from apoE-deficient mice on the C57BL/6 and FVB/N strains. CONCLUSIONS: The 5 identified in silico QTL are candidates for further study to confirm the presence and identity of atherosclerosis susceptibility genes within these loci.


Assuntos
Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Arteriosclerose/genética , Mapeamento Cromossômico/métodos , Predisposição Genética para Doença/genética , Locos de Características Quantitativas/genética , Animais , Cruzamentos Genéticos , Bases de Dados Genéticas , Feminino , Masculino , Camundongos , Camundongos Endogâmicos AKR , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Endogâmicos , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
19.
Brain Res Mol Brain Res ; 124(2): 134-42, 2004 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-15135221

RESUMO

Drugs abused by humans are thought to activate areas in the ventral striatum of the brain that engage the organism in important adaptive behaviors, such as eating. In support of this, we report here that striatal regions of sugar-dependent rats show alterations in dopamine and opioid mRNA levels similar to morphine-dependent rats. Specifically, after a chronic schedule of intermittent bingeing on a sucrose solution, mRNA levels for the D2 dopamine receptor, and the preproenkephalin and preprotachykinin genes were decreased in dopamine-receptive regions of the forebrain, while D3 dopamine receptor mRNA was increased. While morphine affects gene expression across the entire dopamine-receptive striatum, significant differences were detected in the effects of sugar on the nucleus accumbens and adjacent caudate-putamen. The effects of sugar on mRNA levels were of greater magnitude in the nucleus accumbens than in the caudate-putamen. These areas also showed clear differences in the interactions among the genes, especially between D3R and the other genes. This was revealed by a novel multivariate analysis method that identified cooperative interactions among genes, specifically in the nucleus accumbens but not the caudate-putamen. Finally, a role for these cooperative interactions in a load-sharing response to perturbations caused by sugar was supported by the finding of a different pattern of correlations between the genes in the two striatal regions. These findings support a major role for the nucleus accumbens in mediating the effects of naturally rewarding substances and extend an animal model for studying the common substrates of drug addiction and eating disorders.


Assuntos
Encéfalo/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Morfina/farmacologia , Vias Neurais/metabolismo , Recompensa , Sacarose/farmacologia , Animais , Encéfalo/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Encefalinas/genética , Transtornos da Alimentação e da Ingestão de Alimentos/genética , Transtornos da Alimentação e da Ingestão de Alimentos/metabolismo , Expressão Gênica/genética , Perfilação da Expressão Gênica , Masculino , Vias Neurais/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Peptídeos Opioides/genética , Precursores de Proteínas/genética , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Dopamina D2/genética , Receptores de Dopamina D3 , Transtornos Relacionados ao Uso de Substâncias/genética , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Taquicininas/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA