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1.
Rev Chil Pediatr ; 89(2): 224-230, 2018 Apr.
Artículo en Español | MEDLINE | ID: mdl-29799890

RESUMEN

INTRODUCTION: Congenital cystic adenomatoid malformation (CCAM) is a rare congenital lung di sease, and in the most of cases, prenatal diagnosis is feasible. There are discrepancies regarding pre natal management and postpartum treatment. OBJECTIVE: To analyze prenatally diagnosed CCAM in our hospitals, in order to evaluate ultrasound findings with fetal and postnatal evolution. PATIENTS AND METHOD: Retrospective study of all cases diagnosed prenatally by ultrasound between 2005 and 2016 in two reference hospitals. The ultrasounds were performed using high-resolution ultrasound scanners, Toshiba Xario and Voluson 730 Expert Pro, with follow-up from diagnosis to delivery. The variables analyzed included gestational age at diagnosis, the characteristics of the lung lesion, associated malformations, cytogenetic study, the evolution of pregnancy, type of delivery, presence of respiratory distress, need for complementary imaging tests, pediatric clinical course, and necessary postnatal treatments. It was considered a resolution the total disappearance of the lesion in the pre natal ultrasound or that the postnatal chest X-ray showed no lesion. RESULTS: 17 cases were prenatally diagnosed. The evolution ranges from the prenatal resolution of the lesion to the persistence after bir th. Three patients voluntarily decided to have an abortion due to ultrasound findings of poor progno sis. Of the fourteen remaining cases there were no cases of fetal or neonatal deaths, one case required surgery after birth and four patients had mild symptoms during the first year of life. One case of false negative with neonatal death has been reported which necropsy reported as CCAM type 0. Conclu sions: This pulmonary malformation presents good prognosis, excluding cases with fetal hydrops. Two-dimensional ultrasound is usually enough for diagnosis and follow-up. Computed tomography is the technique of choice to confirm the resolution of lesions after birth. Surgical treatment is pre ferable over conservative management, although it is unknown if the potential complications of this disease, even when asymptomatic, justify surgical morbidity.


Asunto(s)
Malformación Adenomatoide Quística Congénita del Pulmón/diagnóstico por imagen , Ultrasonografía Prenatal , Malformación Adenomatoide Quística Congénita del Pulmón/terapia , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Masculino , Embarazo , Pronóstico , Estudios Retrospectivos
2.
Rev Chil Pediatr ; 86(5): 331-6, 2015.
Artículo en Español | MEDLINE | ID: mdl-26320678

RESUMEN

INTRODUCTION: The use of biomarkers could be a tool for diagnosis, prognosis and stratifying children with sepsis. Our main goal was to analyze the value of procalcitonin (PCT), C reactive protein (CRP) and lactate in predicting mortality, septic shock and the stratification in children with suspected sepsis PATIENTS AND METHOD: Prospective study in 81 patients. Plasma levels of PCT, CRP and lactate were measured at admission in the pediatric intensive care unit. Patients were categorized into systemic inflammatory response syndrome, sepsis, severe sepsis and septic shock. RESULTS: Concentrations of PCT (ng/mL) increased significantly according to the severity of sepsis: 0.36 (0-1.2) for systemic inflammatory response syndrome; 1.96 (0.4-3.5) for sepsis; 7.5 (3.9-11.1) for severe sepsis; and 58.9 (35.1-82.7) for septic shock (P<.001). Compared to CRP and lactate, the area under the ROC curve revealed a good discriminative power of PCT to predict septic shock and mortality, 0.91 (95% CI: 0.83-0.97) and 0.80 (95% CI: 0.69-0.88), respectively. CONCLUSIONS: In contrast to CRP and lactate, the determination of PCT in pediatric intensive care unit admission is a good predictor of mortality and septic shock and can stratify patients according to severity of sepsis.


Asunto(s)
Proteína C-Reactiva/metabolismo , Calcitonina/sangre , Ácido Láctico/sangre , Sepsis/sangre , Biomarcadores , Niño , Preescolar , Femenino , Humanos , Lactante , Unidades de Cuidado Intensivo Pediátrico , Masculino , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Sepsis/mortalidad , Sepsis/fisiopatología , Índice de Severidad de la Enfermedad , Choque Séptico/sangre , Choque Séptico/diagnóstico , Síndrome de Respuesta Inflamatoria Sistémica/sangre , Síndrome de Respuesta Inflamatoria Sistémica/fisiopatología
3.
Food Res Int ; 157: 111464, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35761697

RESUMEN

Certain phytochemicals have been found to promote the beneficial effects of probiotic bacteria although the molecular mechanisms of such interactions are poorly understood. The objective of the present study was to evaluate the impact of the exposure to 0.5 mM chlorogenic acid (CA) on the redox status and proteome of Enterococcus faecium isolated from cheese and challenged with 2.5 mM hydrogen peroxide (H2O2). The bacterium was incubated in anaerobic conditions for 48 h at 37 °C. CA exposure led to a more intense oxidative stress and accretion of bacterial protein carbonyls than those induced by H2O2. The oxidative damage to bacterial proteins was even more severe in the bacterium treated with both CA and H2O2, yet, such combination led to a strengthening of the antioxidant defenses, namely, a catalase-like activity. The proteomic study indicated that H2O2 caused a decrease in energy supply and the bacterium responded by reinforcing the membrane and wall structures and counteracting the redox and pH imbalance. CA stimulated the accretion of proteins related to translation and transcription regulators, and hydrolases. This phytochemical was able to counteract certain proteomic changes induced by H2O2 (i.e. increase of ATP binding cassete (ABC) transporter complex) and cause the increase of Rex, a redox-sensitive protein implicated in controlling metabolism and responses to oxidative stress. Although this protection should be confirmed under in vivo conditions, such effects point to benefits in animals or humans affected by disorders in which oxidative stress plays a major role.


Asunto(s)
Enterococcus faecium , Animales , Ácido Clorogénico/farmacología , Enterococcus faecium/metabolismo , Peróxido de Hidrógeno/farmacología , Proteómica , Especies Reactivas de Oxígeno/metabolismo
4.
Int J Organ Transplant Med ; 12(1): 54-58, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34987734

RESUMEN

Increased mortality of COVID-19 has been reported in older patients with diabetes, high blood pressure, lung disease and immunocompromised people such as kidney transplant recipients. Both the behavior of the viral infection and the treatments proposed so far interact with the state of immunosuppression and immunosuppressants. Herein, we report two cases of kidney transplant recipients with COVID-19 infection. The first patient presented with gastrointestinal symptoms and progressively advanced to multilobar pneumonia. The second case presented with fever accompanied by gastrointestinal and urinary symptoms and dry cough. Both patients responded appropriately to treatment.

5.
Med Phys ; 37(11): 6084-95, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21158320

RESUMEN

PURPOSE: This article presents a computer-aided diagnosis technique for improving the accuracy of the early diagnosis of Alzheimer's disease (AD). Two hundred and ten 18F-FDG PET images from the ADNI initiative [52 normal controls (NC), 114 mild cognitive impairment (MCI), and 53 AD subjects] are studied. METHODS: The proposed methodology is based on the selection of voxels of interest using the t-test and a posterior reduction of the feature dimension using factor analysis. Factor loadings are used as features for three different classifiers: Two multivariate Gaussian mixture model, with linear and quadratic discriminant function, and a support vector machine with linear kernel. RESULTS: An accuracy rate up to 95% when NC and AD are considered and an accuracy rate up to 88% and 86% for NC-MCI and NC-MCI,AD, respectively, are obtained using SVM with linear kernel. CONCLUSIONS: Results are compared to the voxel-as-features and a PCA- based approach and the proposed methodology achieves better classification performance.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/diagnóstico , Trastornos del Conocimiento/diagnóstico por imagen , Trastornos del Conocimiento/diagnóstico , Fluorodesoxiglucosa F18/farmacocinética , Tomografía de Emisión de Positrones/métodos , Radiofármacos/farmacocinética , Anciano , Anciano de 80 o más Años , Diagnóstico por Computador , Humanos , Procesamiento de Imagen Asistido por Computador , Persona de Mediana Edad , Modelos Estadísticos , Análisis Multivariante , Distribución Normal , Reproducibilidad de los Resultados
8.
Neuroscience ; 134(4): 1217-22, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16054766

RESUMEN

Metabolic indices of neuronal activity are thought to predict changes in the frequency of action potentials. There are stimuli that do not shift action potential frequency but change the temporal organization of neuronal firing following modifications of excitatory inputs by inhibitory synaptic activation. To our knowledge it is unknown whether this kind of stimulus associates with adjustments of metabolic markers of neuronal activity. Here, we used the hypothalamic-neurohypophysial system of lactating rats to address whether shifts in the temporal organization of neuronal firing relate with modifications of metabolic markers of neuronal activity. Cytochrome oxidase activity, (3)H-2-deoxyglucose uptake, and the area occupied by blood vessels increased in the paraventricular nucleus and neurohypophysis of lactating rats, as compared with their virgin counterparts. Taken together, these results suggest that metabolic demands denote shifts in the temporal organization of action potentials related with the adjustment of excitatory synaptic activation, and support that changes in metabolic markers do not necessarily reflect shifts in the frequency of action potentials.


Asunto(s)
Sistema Hipotálamo-Hipofisario/metabolismo , Lactancia/fisiología , Neuronas/fisiología , Potenciales de Acción/fisiología , Animales , Autorradiografía , Desoxiglucosa/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Femenino , Núcleo Hipotalámico Paraventricular/irrigación sanguínea , Núcleo Hipotalámico Paraventricular/fisiología , Neurohipófisis/irrigación sanguínea , Neurohipófisis/fisiología , Ratas , Ratas Sprague-Dawley
9.
FEBS Lett ; 384(1): 75-7, 1996 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-8797807

RESUMEN

To characterize Ser1029 in STaR at a consensus sequence of phosphorylation site by PKC, two mutants of mS1029A with replacement of Ser1029 to Ala1029 and C delta 1029 lacking 22 amino acids including Ser1029 were prepared. Preincubation of the wild type-STaR (wt-STaR) transfectant with 1 microM PMA caused additional STa-mediated guanylyl cyclase (GC) activation compared to control, whereas the mS1029A- and C delta 1029-transfected cells did not show a similar enhanced GC activation by PMA. After metabolic labeling with [32P]phosphate, transfected cells with wt-STaR and mutants were incubated with 1 microM PMA. Subsequent 32P-radiolabeled proteins were immunoprecipitated using anti-STaR antibody, and analyzed by autoradiography after separation on SDS-PAGE. The immunoprecipitated wt-STaR but not mS1029A and C delta 1029 had a significant radioactivity. These results suggest that the effect of PMA on wt-STaR transfectants may be caused by phosphorylation of Ser1029. The C delta 1012 mutant, with further truncation (Gln1012-Phe1050) of the carboxy terminus, did not show STa-mediated GC activation. Based on these data, these 17 amino acids (Gln1012-Ala1028), essential for signaling of GC activation by STa, have an abundance of basic amino acids which might be functionally influenced by phosphorylation of Ser1029.


Asunto(s)
Guanilato Ciclasa/metabolismo , Proteína Quinasa C/metabolismo , Receptores de Péptidos/metabolismo , Serina , Acetato de Tetradecanoilforbol/farmacología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Activación Enzimática , Guanilato Ciclasa/química , Humanos , Riñón , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Oligodesoxirribonucleótidos , Mutación Puntual , Reacción en Cadena de la Polimerasa , Receptores de Enterotoxina , Receptores Acoplados a la Guanilato-Ciclasa , Receptores de Péptidos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de Señal/efectos de los fármacos , Especificidad por Sustrato , Porcinos
10.
Neurology ; 58(8): 1214-20, 2002 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-11971089

RESUMEN

OBJECTIVE: The San Antonio Lupus Study of Neuropsychiatric Disease is a longitudinal study designed to characterize the spectrum of and important risk factors for specific neuropsychiatric systemic lupus erythematosus (NPSLE) syndromes. METHODS: Subjects must meet criteria for SLE and must be at least 18 years of age. A standardized medical history, neurologic, rheumatologic, and psychiatric examinations, computerized neuropsychological evaluation, and serologic testing are performed. RESULTS: This report is based on the first 128 subjects (120 women and 8 men) who completed the initial study visit. Data from this initial study visit were evaluated for the prevalence of NPSLE using the American College of Rheumatology case definitions for 19 NPSLE syndromes. One or more NPSLE syndromes were present in 80% of subjects: cerebrovascular disease (2, 2%; ischemic stroke); headaches (73, 57%); mononeuropathy (9, 8%; median 8, ulnar 1); movement disorder (1, 1%; chorea); neuropathy, cranial (2, 2%; trigeminal); polyneuropathy (29, 22%; sensorimotor); seizures (21, 16%; partial); anxiety disorder (27, 24%); major depressive-like episode (37, 28%); mood disorder with depressive features (21, 19%); mood disorder with manic features (3, 3%); mood disorder with mixed features (1, 1%); psychosis (6, 5%). In a subset of 67 patients who received standardized neuropsychological testing, 21% had normal results. In the remainder, the following levels of impairment were seen: 43% mild, 30% moderate, and 6% severe. CONCLUSIONS: The prevalence of NPSLE was high in this cohort of unselected patients with SLE. Headaches, cognitive dysfunction, and psychiatric disorders were the most common NPSLE syndromes seen. These results will be easily comparable to other studies also using standardized diagnostic criteria. However, the lack of ethnicity and language-matched normative neuropsychological data may make comparisons of cognitive dysfunction in SLE populations difficult.


Asunto(s)
Lupus Eritematoso Sistémico/epidemiología , Lupus Eritematoso Sistémico/psicología , Trastornos Mentales/epidemiología , Trastornos Mentales/psicología , Enfermedades del Sistema Nervioso/epidemiología , Enfermedades del Sistema Nervioso/psicología , Adulto , Anciano , Cognición/fisiología , Estudios de Cohortes , Femenino , Hemodinámica/fisiología , Humanos , Estudios Longitudinales , Lupus Eritematoso Sistémico/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Examen Neurológico , Pruebas Neuropsicológicas , Prevalencia , Calidad de Vida , Factores de Riesgo , Trombosis/etiología
11.
Arch Med Res ; 23(2): 151-2, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1340280

RESUMEN

Ultrafiltration, gel-sieve chromatography and HPLC were used to purify MLIF. This material was HCl-hydrolyzed and the amino acids analyzed by HPLC-ortho-ophthaldialdehyde. Two hydrophobic non-polar (ile,leu), two uncharged polar (thr,tyr) and two positively charged (basic) (his, arg) amino acids were found in clear excess to their concentration in AMC and thus may intervene in the composition of MLIF.


Asunto(s)
Quimiotaxis de Leucocito/efectos de los fármacos , Entamoeba histolytica/química , Monocitos/efectos de los fármacos , Proteínas Protozoarias/química , Aminoácidos , Animales , Cromatografía Líquida de Alta Presión , Humanos , Proteínas Protozoarias/aislamiento & purificación , Proteínas Protozoarias/farmacología
12.
Diagn Cytopathol ; 19(6): 462-4, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9839139

RESUMEN

Atypical mycobacteriosis of the duodenum was diagnosed by duodenal brush cytology in a woman with AIDS. Smears were fixed in alcohol and stained by the method of Papanicolaou. The cytological characteristics of this disease have been described previously in other cytological specimens such as imprints or fine-needle aspirations stained with Diff-Quik or Wright's stain. We found that alcohol fixation and routine Papanicolaou staining allow observation of numerous foamy and striated macrophages (pseudo-Gaucher cells), as well as negative images both within the cytoplasm of the macrophages and in the background of smears in areas of air-drying artifact. These findings should suggest the diagnosis of atypical mycobacteriosis, and special staining techniques such as PAS and Ziehl-Neelsen are useful in corroborating it. This has not been previously described.


Asunto(s)
Duodeno/microbiología , Infección por Mycobacterium avium-intracellulare/microbiología , Adulto , Duodeno/patología , Femenino , Humanos , Infección por Mycobacterium avium-intracellulare/patología , Prueba de Papanicolaou , Coloración y Etiquetado , Frotis Vaginal
13.
Rev Esp Med Nucl ; 21(6): 410-6, 2002.
Artículo en Español | MEDLINE | ID: mdl-12425888

RESUMEN

Brain perfusion abnormalities after an abstinence period of 28 days in a group of patients with alcohol and / or cocaine dependence was investigated. They were related with gender, consumption period and number of drugs. Fifty men and 10 women were included and SPECT perfusion was performed using 99mTc ethylene cysteine dimer (ECD) with qualitative and semiquantitative section analysis. Perfusion abnormalities were observed in 60% of the patients, principally in frontal, temporal and parietal lobes. The abnormalities were focal in 58.3%, diffuse in 41.7% and bilateral in 95% of all patients. Abnormalities were observed in 68% of the men and in only 20% of the women (p = 0.01). Patients with brain perfusion abnormalities had a longer period of consumption corresponding to a median of 17.5 years in patients with abnormalities versus nine years in those with no abnormalities (p = 0.036), however, their ages as well as the number of drugs consumed were not significantly different. In conclusion, after 28 days of alcohol and / or cocaine abstinence there is significant presence of brain perfusion abnormalities with 99mTc ECD. This could be explained by vasospasm and / or secondary endothelial lesions.


Asunto(s)
Alcoholismo/diagnóstico por imagen , Circulación Cerebrovascular , Trastornos Relacionados con Cocaína/diagnóstico por imagen , Cisteína/análogos & derivados , Compuestos de Organotecnecio , Radiofármacos , Síndrome de Abstinencia a Sustancias/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único , Adolescente , Adulto , Alcoholismo/fisiopatología , Circulación Cerebrovascular/efectos de los fármacos , Cocaína/efectos adversos , Trastornos Relacionados con Cocaína/fisiopatología , Etanol/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndrome de Abstinencia a Sustancias/fisiopatología , Vasoespasmo Intracraneal/inducido químicamente , Vasoespasmo Intracraneal/diagnóstico por imagen
14.
Comput Math Methods Med ; 2013: 760903, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23762198

RESUMEN

A procedure to improve the convergence rate for affine registration methods of medical brain images when the images differ greatly from the template is presented. The methodology is based on a histogram matching of the source images with respect to the reference brain template before proceeding with the affine registration. The preprocessed source brain images are spatially normalized to a template using a general affine model with 12 parameters. A sum of squared differences between the source images and the template is considered as objective function, and a Gauss-Newton optimization algorithm is used to find the minimum of the cost function. Using histogram equalization as a preprocessing step improves the convergence rate in the affine registration algorithm of brain images as we show in this work using SPECT and PET brain images.


Asunto(s)
Encéfalo/diagnóstico por imagen , Neuroimagen/estadística & datos numéricos , Tomografía de Emisión de Positrones/estadística & datos numéricos , Tomografía Computarizada de Emisión de Fotón Único/estadística & datos numéricos , Algoritmos , Mapeo Encefálico/estadística & datos numéricos , Biología Computacional , Cisteína/análogos & derivados , Fluorodesoxiglucosa F18 , Humanos , Modelos Estadísticos , Compuestos de Organotecnecio , Radiofármacos
15.
Rev. chil. pediatr ; 89(2): 224-230, abr. 2018. tab, graf
Artículo en Español | LILACS | ID: biblio-1042715

RESUMEN

INTRODUCCIÓN: La malformación adenomatoidea quística (MAQ) es una patología congénita del pulmón poco frecuente y su diagnóstico prenatal es factible en la mayoría de los casos. Existen discrepancias en cuanto al manejo prenatal y tratamiento postparto. OBJETIVO: Analizar una serie de casos de MAQ diagnosticados prenatalmente, evaluando los hallazgos ecográficos y la evolución fetal y post natal. PACIENTES Y MÉTODO: Estudio retrospectivo de todos los casos diagnosticados prenatalmente por ecografìa entre 2005 y 2016 en dos hospitales de referencia. Los exámenes de ultrasonido fueron realizados utilizando ecógrafos de alta resolución, Toshiba Xario y Voluson 730 Expert Pro, con seguimiento desde el diagnóstico hasta el parto. Las variables analizadas incluyeron la edad gestacional en el momento del diagnóstico, las características de la lesión pulmonar, las malformaciones asocia das, el estudio citogenético, la evolución del embarazo, el tipo de parto, presencia de distrés respira torio, necesidad de pruebas de imagen complementarias, evolución clínica pediátrica y tratamientos postnatales necesarios. Se consideró resolución la desaparición total de la lesión ecográfica prenatal o que la radiografía torácica postnatal no mostrara lesión alguna. RESULTADOS: Se identificaron pre natalmente 17 casos. La evolución varía desde la resolución prenatal de la lesión hasta la persistencia de la misma tras el nacimiento. Tres pacientes decidieron abortar voluntariamente por hallazgos ecográficos de mal pronóstico. De los catorce casos restantes no hubo ningún caso de muerte fetal ni neonatal, un caso requirió cirugía tras el nacimiento y cuatro pacientes presentaron sintomatología leve durante el primer año de vida. Se ha reportado un caso de falso negativo con muerte neonatal, que la necropsia informó como MAQ tipo 0. CONCLUSIONES: Esta malformación pulmonar presenta buen pronóstico, excluyendo los casos con hidrops fetal. La ecografía bidimensional suele ser suficiente para el diagnóstico y el seguimiento. La tomografía computarizada es la técnica de elección para confirmar la resolución de las lesiones tras el nacimiento. El tratamiento quirúrgico es preferible sobre el manejo conservador, aunque se desconoce si las complicaciones potenciales de esta patología, aun siendo asintomática, justifican la morbilidad quirúrgica.


INTRODUCTION: Congenital cystic adenomatoid malformation (CCAM) is a rare congenital lung di sease, and in the most of cases, prenatal diagnosis is feasible. There are discrepancies regarding pre natal management and postpartum treatment. OBJECTIVE: To analyze prenatally diagnosed CCAM in our hospitals, in order to evaluate ultrasound findings with fetal and postnatal evolution. PATIENTS AND METHOD: Retrospective study of all cases diagnosed prenatally by ultrasound between 2005 and 2016 in two reference hospitals. The ultrasounds were performed using high-resolution ultrasound scanners, Toshiba Xario and Voluson 730 Expert Pro, with follow-up from diagnosis to delivery. The variables analyzed included gestational age at diagnosis, the characteristics of the lung lesion, associated malformations, cytogenetic study, the evolution of pregnancy, type of delivery, presence of respiratory distress, need for complementary imaging tests, pediatric clinical course, and necessary postnatal treatments. It was considered a resolution the total disappearance of the lesion in the pre natal ultrasound or that the postnatal chest X-ray showed no lesion. RESULTS: 17 cases were prenatally diagnosed. The evolution ranges from the prenatal resolution of the lesion to the persistence after bir th. Three patients voluntarily decided to have an abortion due to ultrasound findings of poor progno sis. Of the fourteen remaining cases there were no cases of fetal or neonatal deaths, one case required surgery after birth and four patients had mild symptoms during the first year of life. One case of false negative with neonatal death has been reported which necropsy reported as CCAM type 0. CONCLUSIONS: This pulmonary malformation presents good prognosis, excluding cases with fetal hydrops. Two-dimensional ultrasound is usually enough for diagnosis and follow-up. Computed tomography is the technique of choice to confirm the resolution of lesions after birth. Surgical treatment is pre ferable over conservative management, although it is unknown if the potential complications of this disease, even when asymptomatic, justify surgical morbidity.


Asunto(s)
Humanos , Masculino , Femenino , Embarazo , Recién Nacido , Malformación Adenomatoide Quística Congénita del Pulmón/diagnóstico , Ultrasonografía Prenatal , Pronóstico , Malformación Adenomatoide Quística Congénita del Pulmón/terapia , Estudios Retrospectivos , Estudios de Seguimiento
17.
IEEE Trans Med Imaging ; 31(2): 207-16, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21914569

RESUMEN

This paper presents a novel computer-aided diagnosis (CAD) technique for the early diagnosis of the Alzheimer's disease (AD) based on nonnegative matrix factorization (NMF) and support vector machines (SVM) with bounds of confidence. The CAD tool is designed for the study and classification of functional brain images. For this purpose, two different brain image databases are selected: a single photon emission computed tomography (SPECT) database and positron emission tomography (PET) images, both of them containing data for both Alzheimer's disease (AD) patients and healthy controls as a reference. These databases are analyzed by applying the Fisher discriminant ratio (FDR) and nonnegative matrix factorization (NMF) for feature selection and extraction of the most relevant features. The resulting NMF-transformed sets of data, which contain a reduced number of features, are classified by means of a SVM-based classifier with bounds of confidence for decision. The proposed NMF-SVM method yields up to 91% classification accuracy with high sensitivity and specificity rates (upper than 90%). This NMF-SVM CAD tool becomes an accurate method for SPECT and PET AD image classification.


Asunto(s)
Algoritmos , Enfermedad de Alzheimer/diagnóstico por imagen , Mapeo Encefálico/métodos , Interpretación de Imagen Asistida por Computador/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Cintigrafía/métodos , Humanos , Aumento de la Imagen/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Máquina de Vectores de Soporte
18.
Rev. chil. obstet. ginecol. (En línea) ; Rev. chil. obstet. ginecol;82(2): 115-125, abr. 2017. ilus, tab
Artículo en Español | LILACS | ID: biblio-899889

RESUMEN

Objetivo: La detección precoz del riesgo de complicaciones de la gestación como preeclampsia, parto pretérmino, y aborto, permitiría evitar morbimortalidad y secuelas. Hemos estudiado la relación entre niveles bajos de PAPP-A y BhCG con malos resultados obstétricos en una población con alta prevalencia de obesidad. Material y métodos: Estudio retrospectivo de casos y controles anidado en una cohorte de pacientes que acudieron para tamizaje de aneuploidías el I trimestre. Los casos fueron las pacientes con MoM PAPPA y/o BhCG por debajo del percentil 5 y el grupo control una muestra aleatorizada de pacientes con marcadores normales. Se ajustó por obesidad, edad, paridad, tabaquismo, y técnicas de reproducción. Resultados: La cohorte estuvo formada por 9111 pacientes. Se obtuvieron 382 casos con MoM PAPP-A inferior al percentil 5 y 325 con MoM BhCG por debajo del percentil 5, y 50 casos con ambos marcadores por debajo del percentil 5. Se tomaron 1417 controles. La prevalencia de obesidad fue del 20,7% y de sobrepeso el 28,4%. Los niveles bajos de PAPP-A se relacionaron con abortos, preeclampsia, crecimiento intrauterino retardado, pequeños para la edad gestacional, parto pretérmino y diabetes gestacional. Los niveles de BhCG por debajo del percentil 5 se relacionaron con la enfermedad hipertensiva gestacional. Los niveles de ambos marcadores por debajo del percentil 5 tuvieron relación significativa con aborto, preeclampsia precoz y parto pretérmino. Conclusión: Los niveles bajos de PAPP-A y BhCG se relacionan con malos resultados obstétricos en una población de alta prevalencia de obesidad.


Background: Early identification of pregnant women at risk of developing intrauterine growth restriction, preeclampsia, preterm birth, stillbirth, among other complications would allow more intensive surveillance to reduce the risk of severe disease. We aimed to study whether low levels of maternal serum markers PAPP-A and BHCG are associated with adverse pregnancy outcomes in an obese population. Methods: Cases were obtained from a cohort of 9111 patients who attended first trimester screening. We included women with PAPP-A and/or BHCG below the 5th percentile. A randomized group of women with serum markers above the 5th percentile was used as control group. Results were adjusted for age, parity, smoking status, BMI or reproductive techniques. Results: Prevalence of obesity was 20,7%. We found 382 women with PAPP-A below the 5th percentile, 325 with BHCG below the 5th percentile, 50 with both markers low, and recruited 1417 controls. The cases with low PAPP-A were significantly more likely to experience abortion, preeclampsia, low birth weight, preterm birth, or gestational diabetes. Low BHCG was significantly associated with gestational hypertension. Low BHCG and PAPP-A in the same patient correlated with abortion, early preeclampsia and preterm birth. Conclusions: Low levels of maternal serum markers correlate with adverse pregnancy outcomes in an obese population. We recommend to develop further calculators of obstetric risk to improve positive predictive value and to establish a maternal-fetal surveillance plan.


Asunto(s)
Humanos , Femenino , Embarazo , Adulto , Preeclampsia/diagnóstico , Primer Trimestre del Embarazo , Trabajo de Parto Prematuro/diagnóstico , Obesidad/complicaciones , Proteína Plasmática A Asociada al Embarazo/análisis , Resultado del Embarazo , Biomarcadores/sangre , Estudios de Casos y Controles , Aborto Espontáneo/diagnóstico , Tamizaje Masivo , Medición de Riesgo/métodos , Gonadotropina Coriónica/sangre , Obesidad/sangre
19.
Rev. chil. pediatr ; 86(5): 331-336, oct. 2015. graf, tab
Artículo en Español | LILACS | ID: lil-771646

RESUMEN

Introducción: El uso de biomarcadores podría constituir una herramienta en el diagnóstico, pronóstico y estratificación en la sepsis. El objetivo fue analizar el valor de la procalcitonina (PCT), proteína C reactiva (PCR) y lactato en la predicción de shock séptico, mortalidad y en la estratificación en niños con sospecha de sepsis. Pacientes y método: Estudio prospectivo en 81 pacientes en los cuales se midió niveles plasmáticos de PCT, PCR y lactato al ingreso en la unidad de cuidados intensivos. Los pacientes se categorizaron en síndrome de respuesta inflamatoria sistémica, sepsis, sepsis grave y shock séptico. Resultados: Las concentraciones de la PCT (ng/mL) aumentaron significativamente de acuerdo a la gravedad de la sepsis: 0,36 (0-1,2) para síndrome de respuesta inflamatoria sistémica; 1,96 (0,4-3,5) para sepsis; 7,5 (3,9-11,1) en sepsis grave; y 58,9 (35,1-82,7) para shock séptico (p < 0,001). Comparada con la PCR y el lactato, el área bajo la curva ROC reveló un poder discriminativo favorable de la PCT para predecir shock séptico y mortalidad: 0,91 (IC95%: 0,83-0,97) y 0,80 (IC95%: 0,69-0,88), respectivamente. Conclusiones: A diferencia de la PCR y el lactato, la determinación de la PCT al ingreso en la unidad de cuidados intensivos es un buen predictor de shock séptico y mortalidad, y permite estratificar a los pacientes de acuerdo a la gravedad de la sepsis.


Introduction: The use of biomarkers could be a tool for diagnosis, prognosis and stratifying children with sepsis. Our main goal was to analyze the value of procalcitonin (PCT), C reactive protein (CRP) and lactate in predicting mortality, septic shock and the stratification in children with suspected sepsis Patients and method: Prospective study in 81 patients. Plasma levels of PCT, CRP and lactate were measured at admission in the pediatric intensive care unit. Patients were categorized into systemic inflammatory response syndrome, sepsis, severe sepsis and septic shock. Results: Concentrations of PCT (ng/mL) increased significantly according to the severity of sepsis: 0.36 (0-1.2) for systemic inflammatory response syndrome; 1.96 (0.4-3.5) for sepsis; 7.5 (3.9-11.1) for severe sepsis; and 58.9 (35.1-82.7) for septic shock (P <.001). Compared to CRP and lactate, the area under the ROC curve revealed a good discriminative power of PCT to predict septic shock and mortality, 0.91 (95% CI: 0.83-0.97) and 0.80 (95% CI: 0.69-0.88), respectively. Conclusions: In contrast to CRP and lactate, the determination of PCT in pediatric intensive care unit admission is a good predictor of mortality and septic shock and can stratify patients according to severity of sepsis.


Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Proteína C-Reactiva/metabolismo , Calcitonina/sangre , Sepsis/sangre , Ácido Láctico/sangre , Pronóstico , Choque Séptico/diagnóstico , Choque Séptico/sangre , Índice de Severidad de la Enfermedad , Biomarcadores , Unidades de Cuidado Intensivo Pediátrico , Valor Predictivo de las Pruebas , Estudios Prospectivos , Síndrome de Respuesta Inflamatoria Sistémica/fisiopatología , Síndrome de Respuesta Inflamatoria Sistémica/sangre , Sepsis/fisiopatología , Sepsis/mortalidad
20.
Neurosci Lett ; 472(2): 99-103, 2010 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-20117177

RESUMEN

This letter shows a computer aided diagnosis (CAD) technique for the early detection of the Alzheimer's disease (AD) by means of single photon emission computed tomography (SPECT) image classification. The proposed method is based on partial least squares (PLS) regression model and a random forest (RF) predictor. The challenge of the curse of dimensionality is addressed by reducing the large dimensionality of the input data by downscaling the SPECT images and extracting score features using PLS. A RF predictor then forms an ensemble of classification and regression tree (CART)-like classifiers being its output determined by a majority vote of the trees in the forest. A baseline principal component analysis (PCA) system is also developed for reference. The experimental results show that the combined PLS-RF system yields a generalization error that converges to a limit when increasing the number of trees in the forest. Thus, the generalization error is reduced when using PLS and depends on the strength of the individual trees in the forest and the correlation between them. Moreover, PLS feature extraction is found to be more effective for extracting discriminative information from the data than PCA yielding peak sensitivity, specificity and accuracy values of 100%, 92.7%, and 96.9%, respectively. Moreover, the proposed CAD system outperformed several other recently developed AD CAD systems.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador , Tomografía Computarizada de Emisión de Fotón Único , Cisteína/análogos & derivados , Humanos , Análisis de los Mínimos Cuadrados , Compuestos de Organotecnecio , Radiofármacos , Sensibilidad y Especificidad
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