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1.
J Alzheimers Dis ; 96(1): 215-227, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37718818

RESUMEN

BACKGROUND: Neuropathological and neuroimaging studies have demonstrated degeneration of the serotonin system in Alzheimer's disease (AD). Neuroimaging studies have extended these observations to the preclinical stages of AD, mild cognitive impairment (MCI). Serotonin degeneration has been observed also in transgenic amyloid mouse models, prior to widespread cortical distribution of amyloid-ß (Aß). OBJECTIVE: The present study evaluated the regional distribution of the serotonin transporter (5-HTT) and of Aß in individuals with MCI and healthy older controls, as well as the contribution of 5-HTT and Aß to cognitive deficits. METHODS: Forty-nine MCI participants and 45 healthy older controls underwent positron emission tomography (PET) imaging of 5-HTT and Aß, structural magnetic resonance imaging and neuropsychological assessments. RESULTS: Lower cortical, striatal, and limbic 5-HTT and higher cortical Aß was observed in MCIs relative to healthy controls. Lower 5-HTT, mainly in limbic regions, was correlated with greater deficits in auditory-verbal and visual-spatial memory and semantic, not phonemic fluency. Higher cortical A ß was associated with greater deficits in auditory-verbal and visual-spatial memory and in semantic, not phonemic fluency. When modeling the association between cognition, gray matter volumes and Aß, inclusion of 5-HTT in limbic and in select cortical regions significantly improved model fit for auditory-verbal and visual-spatial memory and semantic, but not phonemic fluency. CONCLUSIONS: These results support the role of serotonin degeneration in the memory and semantic fluency deficits observed in MCI.


Asunto(s)
Enfermedad de Alzheimer , Trastornos del Conocimiento , Disfunción Cognitiva , Animales , Ratones , Humanos , Serotonina , Disfunción Cognitiva/patología , Trastornos del Conocimiento/complicaciones , Péptidos beta-Amiloides , Enfermedad de Alzheimer/patología , Cognición , Tomografía de Emisión de Positrones
2.
J Family Reprod Health ; 16(1): 78-85, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35903761

RESUMEN

Objective: Non-tubal ectopic pregnancies (EPs) are rare and potentially life threatening. The number is rising due to various risk factors and there are no uniform guidelines in the management of EPs. This study was done to assess risk factors and challenges in the management of EPs. Materials and methods: This is a retrospective observational descriptive study that was done at SDM College of Medical Sciences & Hospital, Shri Dharmasthala Manjunatheshwara University Dharwad, Karnataka India. Data was collected from the medical records section of all the patients of non-tubal ectopic pregnancies managed in our hospital from January 2020 to June 2021. The collected data were analyzed for demographic characteristics, risk factors and management. Results: The incidence of ectopic pregnancies in our institute was 6-7 per 1000 pregnancies, of which 20% of the ectopic pregnancies were non-tubal. The incidence was higher than the other studies, which could be due to our center being a tertiary care referral center. Cesarean scar ectopic pregnancies were the most common accounting for 60% of cases. The management varied from conservative to minimally invasive surgery to hysterectomy hysterectomy with bilateral internal iliac artery ligation, depending upon the clinical presentation, duration of gestation, presence of fetal cardiac activity and hemodynamic stability. The other non-tubal ectopic pregnancies were cervical, ovarian, corneal and heterotopic. Cervical pregnancy beyond 12 weeks of gestation was rare which was managed by conserving the uterus. Conclusion: Non-tubal ectopic pregnancies are rare. Early diagnosis requires a high index of suspicion if missed can lead to an array of complications leading to loss of fertility, morbidity, and mortality. The key step to avert the complications is early diagnosis and individualized treatment.

3.
Brain Commun ; 4(1): fcac016, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35233522

RESUMEN

Beta-amyloid deposition is one of the earliest pathological markers associated with Alzheimer's disease. Mild cognitive impairment in the setting of beta-amyloid deposition is considered to represent a preclinical manifestation of Alzheimer's disease. In vivo imaging studies are unique in their potential to advance our understanding of the role of beta-amyloid deposition in cognitive deficits in Alzheimer's disease and in mild cognitive impairment. Previous work has shown an association between global cortical measures of beta-amyloid deposition ('amyloid positivity') in mild cognitive impairment with greater cognitive deficits and greater risk of progression to Alzheimer's disease. The focus of the present study was to examine the relationship between the regional distribution of beta-amyloid deposition and specific cognitive deficits in people with mild cognitive impairment and cognitively normal elderly individuals. Forty-seven participants with multi-domain, amnestic mild cognitive impairment (43% female, aged 57-82 years) and 37 healthy, cognitively normal comparison subjects (42% female, aged 55-82 years) underwent clinical and neuropsychological assessments and high-resolution positron emission tomography with the radiotracer 11C-labelled Pittsburgh compound B to measure beta-amyloid deposition. Brain-behaviour partial least-squares analysis was conducted to identify spatial patterns of beta-amyloid deposition that correlated with the performance on neuropsychological assessments. Partial least-squares analysis identified a single significant (P < 0.001) latent variable which accounted for 80% of the covariance between demographic and cognitive measures and beta-amyloid deposition. Performance in immediate verbal recall (R = -0.46 ± 0.07, P < 0.001), delayed verbal recall (R = -0.39 ± 0.09, P < 0.001), immediate visual-spatial recall (R = -0.39 ± 0.08, P < 0.001), delayed visual-spatial recall (R = -0.45 ± 0.08, P < 0.001) and semantic fluency (R = -0.33 ± 0.11, P = 0.002) but not phonemic fluency (R = -0.05 ± 0.12, P < 0.705) negatively covaried with beta-amyloid deposition in the identified regions. Partial least-squares analysis of the same cognitive measures with grey matter volumes showed similar associations in overlapping brain regions. These findings suggest that the regional distribution of beta-amyloid deposition and grey matter volumetric decreases is associated with deficits in executive function and memory in mild cognitive impairment. Longitudinal analysis of these relationships may advance our understanding of the role of beta-amyloid deposition in relation to grey matter volumetric decreases in cognitive decline.

4.
Int J Genomics ; 2017: 6576840, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28280724

RESUMEN

The use of gene expression-based classifiers has resulted in a number of promising potential signatures of patient diagnosis, prognosis, and response to therapy. However, these approaches have also created difficulties in trying to use gene expression alone to predict a complex trait. A practical approach to this problem is to integrate existing biological knowledge with gene expression to build a composite predictor. We studied the problem of predicting radiation sensitivity within human cancer cell lines from gene expression. First, we present evidence for the need to integrate known biological conditions (tissue of origin, RAS, and p53 mutational status) into a gene expression prediction problem involving radiation sensitivity. Next, we demonstrate using linear regression, a technique for incorporating this knowledge. The resulting correlations between gene expression and radiation sensitivity improved through the use of this technique (best-fit adjusted R2 increased from 0.3 to 0.84). Overfitting of data was examined through the use of simulation. The results reinforce the concept that radiation sensitivity is not driven solely by gene expression, but rather by a combination of distinct parameters. We show that accounting for biological heterogeneity significantly improves the ability of the model to identify genes that are associated with radiosensitivity.

5.
Compr Psychiatry ; 75: 117-124, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28359017

RESUMEN

BACKGROUND: Clinicians have long considered doubt to be a fundamental characteristic of obsessive-compulsive disorder (OCD). However, the clinical relevance of doubt in OCD has not been addressed. METHODS: Participants included 1182 adults with OCD who had participated in family and genetic studies of OCD. We used a clinical measure of the severity of doubt, categorized as none, mild, moderate, severe, or extreme. We evaluated the relationship between doubt and OCD clinical features, Axis I disorders, personality and personality disorder dimensions, impairment, and treatment response. RESULTS: The severity of doubt was inversely related to the age at onset of OCD symptoms. Doubt was strongly related to the number of checking symptoms and, to a lesser extent, to the numbers of contamination/cleaning and hoarding symptoms. Doubt also was related to the lifetime prevalence of recurrent major depression and generalized anxiety disorder; to the numbers of avoidant, dependent, and obsessive-compulsive personality disorder traits; and to neuroticism and introversion. Moreover, doubt was strongly associated with global impairment and poor response to cognitive behavioral treatment (CBT), even adjusting for OCD severity and other correlates of doubt. CONCLUSIONS: Doubt is associated with important clinical features of OCD, including impairment and cognitive-behavioral treatment response.


Asunto(s)
Emociones , Trastorno Obsesivo Compulsivo/psicología , Adolescente , Adulto , Edad de Inicio , Anciano , Anciano de 80 o más Años , Trastornos de Ansiedad/psicología , Terapia Cognitivo-Conductual , Trastorno de Personalidad Compulsiva/psicología , Trastorno Depresivo Mayor/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neuroticismo , Trastornos de la Personalidad/psicología , Adulto Joven
6.
J Clin Invest ; 124(5): 2172-87, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24691442

RESUMEN

The epithelial-to-mesenchymal transition (EMT) transcriptional program is characterized by repression of E-cadherin (CDH1) and induction of N-cadherin (CDH2), and mesenchymal genes like vimentin (VIM). Placenta-specific 8 (PLAC8) has been implicated in colon cancer; however, how PLAC8 contributes to disease is unknown, and endogenous PLAC8 protein has not been studied. We analyzed zebrafish and human tissues and found that endogenous PLAC8 localizes to the apical domain of differentiated intestinal epithelium. Colon cancer cells with elevated PLAC8 levels exhibited EMT features, including increased expression of VIM and zinc finger E-box binding homeobox 1 (ZEB1), aberrant cell motility, and increased invasiveness. In contrast to classical EMT, PLAC8 overexpression reduced cell surface CDH1 and upregulated P-cadherin (CDH3) without affecting CDH2 expression. PLAC8-induced EMT was linked to increased phosphorylated ERK2 (p-ERK2), and ERK2 knockdown restored cell surface CDH1 and suppressed CDH3, VIM, and ZEB1 upregulation. In vitro, PLAC8 directly bound and inactivated the ERK2 phosphatase DUSP6, thereby increasing p-ERK2. In a murine xenograft model, knockdown of endogenous PLAC8 in colon cancer cells resulted in smaller tumors, reduced local invasion, and decreased p-ERK2. Using MultiOmyx, a multiplex immunofluorescence-based methodology, we observed coexpression of cytosolic PLAC8, CDH3, and VIM at the leading edge of a human colorectal tumor, supporting a role for PLAC8 in cancer invasion in vivo.


Asunto(s)
Neoplasias del Colon/metabolismo , Transición Epitelial-Mesenquimal , Mucosa Intestinal/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas/metabolismo , Proteínas de Pez Cebra/metabolismo , Pez Cebra/metabolismo , Animales , Antígenos CD , Cadherinas/biosíntesis , Cadherinas/genética , Línea Celular Tumoral , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Fosfatasa 6 de Especificidad Dual , Células HEK293 , Humanos , Mucosa Intestinal/patología , Ratones , Proteína Quinasa 1 Activada por Mitógenos/genética , Invasividad Neoplásica , Proteínas de Neoplasias/genética , Proteínas/genética , Vimentina/biosíntesis , Vimentina/genética , Pez Cebra/genética , Proteínas de Pez Cebra/genética
7.
Proc Natl Acad Sci U S A ; 110(29): 11982-7, 2013 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-23818604

RESUMEN

Limitations on the number of unique protein and DNA molecules that can be characterized microscopically in a single tissue specimen impede advances in understanding the biological basis of health and disease. Here we present a multiplexed fluorescence microscopy method (MxIF) for quantitative, single-cell, and subcellular characterization of multiple analytes in formalin-fixed paraffin-embedded tissue. Chemical inactivation of fluorescent dyes after each image acquisition round allows reuse of common dyes in iterative staining and imaging cycles. The mild inactivation chemistry is compatible with total and phosphoprotein detection, as well as DNA FISH. Accurate computational registration of sequential images is achieved by aligning nuclear counterstain-derived fiducial points. Individual cells, plasma membrane, cytoplasm, nucleus, tumor, and stromal regions are segmented to achieve cellular and subcellular quantification of multiplexed targets. In a comparison of pathologist scoring of diaminobenzidine staining of serial sections and automated MxIF scoring of a single section, human epidermal growth factor receptor 2, estrogen receptor, p53, and androgen receptor staining by diaminobenzidine and MxIF methods yielded similar results. Single-cell staining patterns of 61 protein antigens by MxIF in 747 colorectal cancer subjects reveals extensive tumor heterogeneity, and cluster analysis of divergent signaling through ERK1/2, S6 kinase 1, and 4E binding protein 1 provides insights into the spatial organization of mechanistic target of rapamycin and MAPK signal transduction. Our results suggest MxIF should be broadly applicable to problems in the fields of basic biological research, drug discovery and development, and clinical diagnostics.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/diagnóstico , Neoplasias del Colon/diagnóstico , Formaldehído , Microscopía Fluorescente/métodos , Adhesión en Parafina/métodos , 3,3'-Diaminobencidina/metabolismo , Línea Celular Tumoral , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Hibridación Fluorescente in Situ , Receptor ErbB-2/metabolismo , Receptores Androgénicos/metabolismo , Receptores de Estrógenos/metabolismo , Estadísticas no Paramétricas , Proteína p53 Supresora de Tumor/metabolismo
8.
Biol Open ; 2(5): 439-47, 2013 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-23789091

RESUMEN

Epithelial organ morphogenesis involves reciprocal interactions between epithelial and mesenchymal cell types to balance progenitor cell retention and expansion with cell differentiation for evolution of tissue architecture. Underlying submandibular salivary gland branching morphogenesis is the regulated proliferation and differentiation of perhaps several progenitor cell populations, which have not been characterized throughout development, and yet are critical for understanding organ development, regeneration, and disease. Here we applied a serial multiplexed fluorescent immunohistochemistry technology to map the progressive refinement of the epithelial and mesenchymal cell populations throughout development from embryonic day 14 through postnatal day 20. Using computational single cell analysis methods, we simultaneously mapped the evolving temporal and spatial location of epithelial cells expressing subsets of differentiation and progenitor markers throughout salivary gland development. We mapped epithelial cell differentiation markers, including aquaporin 5, PSP, SABPA, and mucin 10 (acinar cells); cytokeratin 7 (ductal cells); and smooth muscle α-actin (myoepithelial cells) and epithelial progenitor cell markers, cytokeratin 5 and c-kit. We used pairwise correlation and visual mapping of the cells in multiplexed images to quantify the number of single- and double-positive cells expressing these differentiation and progenitor markers at each developmental stage. We identified smooth muscle α-actin as a putative early myoepithelial progenitor marker that is expressed in cytokeratin 5-negative cells. Additionally, our results reveal dynamic expansion and redistributions of c-kit- and K5-positive progenitor cell populations throughout development and in postnatal glands. The data suggest that there are temporally and spatially discreet progenitor populations that contribute to salivary gland development and homeostasis.

9.
Clin Cancer Res ; 18(18): 5134-43, 2012 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-22832933

RESUMEN

PURPOSE: Previously, we developed a radiosensitivity molecular signature [radiosensitivity index (RSI)] that was clinically validated in 3 independent datasets (rectal, esophageal, and head and neck) in 118 patients. Here, we test RSI in radiotherapy (RT)-treated breast cancer patients. EXPERIMENTAL DESIGN: RSI was tested in 2 previously published breast cancer datasets. Patients were treated at the Karolinska University Hospital (n = 159) and Erasmus Medical Center (n = 344). RSI was applied as previously described. RESULTS: We tested RSI in RT-treated patients (Karolinska). Patients predicted to be radiosensitive (RS) had an improved 5-year relapse-free survival when compared with radioresistant (RR) patients (95% vs. 75%, P = 0.0212), but there was no difference between RS/RR patients treated without RT (71% vs. 77%, P = 0.6744), consistent with RSI being RT-specific (interaction term RSI × RT, P = 0.05). Similarly, in the Erasmus dataset, RT-treated RS patients had an improved 5-year distant metastasis-free survival over RR patients (77% vs. 64%, P = 0.0409), but no difference was observed in patients treated without RT (RS vs. RR, 80% vs. 81%, P = 0.9425). Multivariable analysis showed RSI is the strongest variable in RT-treated patients (Karolinska, HR = 5.53, P = 0.0987, Erasmus, HR = 1.64, P = 0.0758) and in backward selection (removal α of 0.10), RSI was the only variable remaining in the final model. Finally, RSI is an independent predictor of outcome in RT-treated ER(+) patients (Erasmus, multivariable analysis, HR = 2.64, P = 0.0085). CONCLUSIONS: RSI is validated in 2 independent breast cancer datasets totaling 503 patients. Including prior data, RSI is validated in 5 independent cohorts (621 patients) and represents, to our knowledge, the most extensively validated molecular signature in radiation oncology.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/radioterapia , Tolerancia a Radiación/genética , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/mortalidad , Femenino , Humanos , Menopausia , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Transcriptoma , Resultado del Tratamiento
10.
Public Health Nutr ; 15(11): 2040-6, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22647430

RESUMEN

OBJECTIVE: Breakfast has been linked to several aspects of health, yet breakfast skipping is rampant across the globe. Studies in India have focused mostly on children. Hence the present study examined breakfast behaviour across different age and gender groups. DESIGN: Cross-sectional sample, purposive sampling. Nutrient intakes of the participants derived from 24 h dietary recall and 3 d breakfast record data were compared with RDA values prescribed by the Indian Council of Medical Research using Student's t test, with P < 0·05 taken to indicate significance. SETTING: Mumbai, India. SUBJECTS: Participants (n 1027) aged 8 years and above. RESULTS: Nutritional adequacy of the breakfast meal and that of the day's diet were the main outcome measures. Eighty-one per cent of the participants had a nutritionally inadequate breakfast. Intakes of Fe and dietary fibre were notably low. Consumption of just milk or milk plus a milk food-based drink among schoolchildren (49 %) and increased breakfast skipping among adolescents (37 %) were seen. CONCLUSIONS: The study identifies both irregularities and/or nutritional inadequacies with respect to the breakfast meal. Age- and gender-specific challenges in breakfast behaviour need to be addressed. Development of 'nutrient-dense' breakfast foods that can be prepared easily, school breakfast programmes and education on the importance of breakfast are the needs of the hour.


Asunto(s)
Desayuno , Dieta/normas , Conducta Alimentaria , Evaluación Nutricional , Adolescente , Adulto , Bebidas , Niño , Fibras de la Dieta/administración & dosificación , Ingestión de Energía , Femenino , Humanos , India , Hierro de la Dieta/administración & dosificación , Masculino , Persona de Mediana Edad , Política Nutricional , Clase Social , Trabajo , Adulto Joven
11.
J Clin Invest ; 120(3): 840-9, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20197623

RESUMEN

Transformation of epithelial cells is associated with loss of cell polarity, which includes alterations in cell morphology as well as changes in the complement of plasma membrane proteins. Rab proteins regulate polarized trafficking to the cell membrane and therefore represent potential regulators of this neoplastic transition. Here we have demonstrated a tumor suppressor function for Rab25 in intestinal neoplasia in both mice and humans. Human colorectal adenocarcinomas exhibited reductions in Rab25 expression independent of stage, with lower Rab25 expression levels correlating with substantially shorter patient survival. In wild-type mice, Rab25 was strongly expressed in cells luminal to the proliferating cells of intestinal crypts. While Rab25-deficient mice did not exhibit gross pathology, ApcMin/+ mice crossed onto a Rab25-deficient background showed a 4-fold increase in intestinal polyps and a 2-fold increase in colonic tumors compared with parental ApcMin/+ mice. Rab25-deficient mice had decreased beta1 integrin staining in the lateral membranes of villus cells, and this pattern was accentuated in Rab25-deficient mice crossed onto the ApcMin/+ background. Additionally, Smad3+/- mice crossed onto a Rab25-deficient background demonstrated a marked increase in colonic tumor formation. Taken together, these results suggest that Rab25 may function as a tumor suppressor in intestinal epithelial cells through regulation of protein trafficking to the cell surface.


Asunto(s)
Adenocarcinoma/metabolismo , Transformación Celular Neoplásica/metabolismo , Neoplasias Colorrectales/metabolismo , Células Epiteliales/metabolismo , Proteínas/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Adenocarcinoma/genética , Animales , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Células Epiteliales/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Integrina beta1/biosíntesis , Integrina beta1/genética , Pólipos Intestinales/genética , Pólipos Intestinales/metabolismo , Pólipos Intestinales/patología , Masculino , Ratones , Ratones Noqueados , Estadificación de Neoplasias , Proteínas/genética , Proteína smad3/genética , Proteína smad3/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas de Unión al GTP rab/genética
12.
Clin Cancer Res ; 15(24): 7642-7651, 2009 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-19996206

RESUMEN

PURPOSE: Colorectal cancer prognosis is currently predicted from pathologic staging, providing limited discrimination for Dukes stage B and C disease. Additional markers for outcome are required to help guide therapy selection for individual patients. EXPERIMENTAL DESIGN: A multisite single-platform microarray study was done on 553 colorectal cancers. Gene expression changes were identified between stage A and D tumors (three training sets) and assessed as a prognosis signature in stage B and C tumors (independent test and external validation sets). RESULTS: One hundred twenty-eight genes showed reproducible expression changes between three sets of stage A and D cancers. Using consistent genes, stage B and C cancers clustered into two groups resembling early-stage and metastatic tumors. A Prediction Analysis of Microarray algorithm was developed to classify individual intermediate-stage cancers into stage A-like/good prognosis or stage D-like/poor prognosis types. For stage B patients, the treatment adjusted hazard ratio for 6-year recurrence in individuals with stage D-like cancers was 10.3 (95% confidence interval, 1.3-80.0; P = 0.011). For stage C patients, the adjusted hazard ratio was 2.9 (95% confidence interval, 1.1-7.6; P = 0.016). Similar results were obtained for an external set of stage B and C patients. The prognosis signature was enriched for downregulated immune response genes and upregulated cell signaling and extracellular matrix genes. Accordingly, sparse tumor infiltration with mononuclear chronic inflammatory cells was associated with poor outcome in independent patients. CONCLUSIONS: Metastasis-associated gene expression changes can be used to refine traditional outcome prediction, providing a rational approach for tailoring treatments to subsets of patients. (Clin Cancer Res 2009;15(24):7642-51).

14.
Neurol India ; 56(2): 195-7, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18688149

RESUMEN

We report a 29-year-old man with a unique presentation of vasculitis as acute unilateral subdural effusion and meningoencephalitis. Magnetic resonance imaging showed a brainstem lesion that spread to the thalamus over time. There were no systemic features of vasculitis other than a positive pathergy test. Histopathological examination from the pathergy site showed neutrophilic infiltrate and leucocytoclastic vasculitis. The condition was steroid responsive and he remained in remission at two years' follow-up. The anatomy of the brainstem lesion, absence of other inflammatory and infective conditions on evaluation suggests a vasculitic pathology either as primary central nervous system angiitis or as neurological presentation of systemic vasculitis like Behetaet's disease although the international diagnostic criteria for Behetaet's were not fulfilled.


Asunto(s)
Efusión Subdural/etiología , Vasculitis/complicaciones , Adulto , Tronco Encefálico/patología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Efusión Subdural/patología , Tomografía Computarizada por Rayos X/métodos
15.
Artículo en Inglés | MEDLINE | ID: mdl-19164012

RESUMEN

Gene expression signatures identify important genes that predict a specified outcome. In several notable diseases such as leukemia and breast cancer, the results have been encouraging. In these datasets, many techniques work well when discriminating particular outcomes. However, these same methods, applied to other datasets, are unable to achieve similar levels of success. Given the small sample sizes common to these studies and the large dimensionality of the data, several key issues exist when attempting to construct reliable, reproducible gene signatures. The classifiers may not be sufficient to discriminate classes, or the data itself may not be sufficient to produce effective separation. In this paper, three simple measures of classification complexity are considered to explore a limit to the predictive accuracy that can be achieved in a dataset. Two independent gene expression datasets (lung and colorectal cancer) are considered, using three different outcomes on each dataset. Four different classifiers, using the t-test for feature selection, were tested on these datasets as a representative panel of classifiers. Our results indicate that Fisher's discriminant ratio provides a good measure of the complexity of the classification problem, with a high correlation between complexity and best classification accuracy across all problems (R(2)=0.78). Specifically, predicting gender is a low complexity problem as indicated both by the complexity measure and the classification results. More clinically-oriented endpoints are more complex and have lower classification accuracies. Therefore, classification complexity can be used to estimate maximum attainable accuracy for a problem reducing the need to evaluate many different classifiers.


Asunto(s)
Biomarcadores de Tumor/análisis , Diagnóstico por Computador/métodos , Perfilación de la Expresión Génica/métodos , Neoplasias/diagnóstico , Neoplasias/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Algoritmos , Inteligencia Artificial , Humanos , Proteínas de Neoplasias/análisis , Reproducibilidad de los Resultados , Tamaño de la Muestra , Sensibilidad y Especificidad , Procesamiento de Señales Asistido por Computador
16.
Artículo en Inglés | MEDLINE | ID: mdl-19163357

RESUMEN

Biophotonic imaging can be used to characterize tumor growth in animal models. Estimation of the numbers and location of target cells is dependent on accurate segmentation of a target region from the background luminescence of the animal body. Existing software systems extract general regions of interest in complex images but can fail to detect details or faint regions of interest in the presence of higher luminescent activity. Limited work has been published in the analysis of these images. We explore the use of popular medical image segmentation techniques in segmentation of bioluminescence images. The ability of each algorithm in detecting regions of interest is tested using established performance measures. Based on the characteristics of bioluminescence images of animal tumor models, and the performance of the algorithms, we formulate a framework for segmentation techniques best suited for this application.


Asunto(s)
Modelos Animales de Enfermedad , Interpretación de Imagen Asistida por Computador/métodos , Neoplasias/patología , Algoritmos , Animales , Línea Celular Tumoral , Reacciones Falso Positivas , Humanos , Procesamiento de Imagen Asistido por Computador , Luminiscencia , Ratones , Ratones Endogámicos BALB C , Fotones , Reproducibilidad de los Resultados , Programas Informáticos
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