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1.
J Med Imaging (Bellingham) ; 10(6): 061107, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37794884

RESUMO

Purpose: Retinopathy of prematurity (ROP) is a retinal vascular disease affecting premature infants that can culminate in blindness within days if not monitored and treated. A disease stage for scrutiny and administration of treatment within ROP is "plus disease" characterized by increased tortuosity and dilation of posterior retinal blood vessels. The monitoring of ROP occurs via routine imaging, typically using expensive instruments ($50 to $140 K) that are unavailable in low-resource settings at the point of care. Approach: As part of the smartphone-ROP program to enable referrals to expert physicians, fundus images are acquired using smartphone cameras and inexpensive lenses. We developed methods for artificial intelligence determination of plus disease, consisting of a preprocessing pipeline to enhance vessels and harmonize images followed by deep learning classification. A deep learning binary classifier (plus disease versus no plus disease) was developed using GoogLeNet. Results: Vessel contrast was enhanced by 90% after preprocessing as assessed by the contrast improvement index. In an image quality evaluation, preprocessed and original images were evaluated by pediatric ophthalmologists from the US and South America with years of experience diagnosing ROP and plus disease. All participating ophthalmologists agreed or strongly agreed that vessel visibility was improved with preprocessing. Using images from various smartphones, harmonized via preprocessing (e.g., vessel enhancement and size normalization) and augmented in physically reasonable ways (e.g., image rotation), we achieved an area under the ROC curve of 0.9754 for plus disease on a limited dataset. Conclusions: Promising results indicate the potential for developing algorithms and software to facilitate the usage of cell phone images for staging of plus disease.

2.
Birth Defects Res ; 113(18): 1299-1312, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34491004

RESUMO

BACKGROUND: Our aim was to describe the neuroimaging and clinical evaluations of children with antenatal Zika-virus (ZIKV) exposure. METHODS: The Colombian National Institute of Health performed serial clinical evaluations of children with probable antenatal ZIKV exposure (i.e., born to ZIKV symptomatic mothers or born with birth defects compatible with ZIKV infection, regardless of laboratory results) over 2 years that included head circumference (HC), eye examination, and neurodevelopmental assessments. Clinical neuroimaging studies (head computed tomography and/or brain magnetic resonance imaging) were analyzed for abnormalities, two-dimensional measurements were made of the right and left frontal and occipital cortical thickness. Two abnormal patterns were defined: Pattern 1 (sum of four areas of cortex <6 cm) and Pattern 2 (sum of four areas of cortex ≥6 cm and < 10 cm). RESULTS: Thirty-one children had a neuroimaging study; in 24, cortical thickness was measured. The median age at the first visit was 8 (range: 6-9) months and 22 (range: 19-42) months at the last evaluation. In the 24 cases with cortical measurements, three were normal, 12 were in Pattern 1, and nine were in Pattern 2. Children within Pattern 1 had lower mean HC at birth and in follow-up (both p < .05) and a higher frequency of structural eye abnormalities (p < .01). A trend towards poorer neuromotor development was seen in Pattern 1, although not statistically significant (p = .06). CONCLUSION: Brain imaging classification based on cortical measurements correlate with ophthalmologic abnormalities and HC. Cortical thickness may be a marker for clinical outcomes in children with congenital ZIKV infection.


Assuntos
Microcefalia , Complicações Infecciosas na Gravidez , Infecção por Zika virus , Zika virus , Encéfalo/diagnóstico por imagem , Criança , Colômbia , Feminino , Humanos , Recém-Nascido , Neuroimagem , Gravidez
3.
J Biomech Eng ; 139(3)2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28024161

RESUMO

The role of trabeculae carneae in modulating left ventricular (LV) diastolic compliance remains unclear. The objective of this study was to determine the contribution of trabeculae carneae to the LV diastolic compliance. LV pressure-volume compliance curves were measured in six human heart explants from patients with LV hypertrophy at baseline and following trabecular cutting. The effect of trabecular cutting was also analyzed with finite-element model (FEM) simulations. Our results demonstrated that LV compliance improved after trabecular cutting (p < 0.001). Finite-element simulations further demonstrated that stiffer trabeculae reduce LV compliance further, and that the presence of trabeculae reduced the wall stress in the apex. In conclusion, we demonstrate that integrity of the LV and trabeculae is important to maintain LV stiffness and loss in trabeculae leads to more LV compliance.


Assuntos
Diástole/fisiologia , Ventrículos do Coração , Miocárdio/metabolismo , Função Ventricular Esquerda , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Estresse Mecânico
4.
J Sex Med ; 5(1): 122-31, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17655659

RESUMO

INTRODUCTION: In spite of significant changes in the management policies of intersexuality, clinical evidence show that not all pubertal or adult individuals live according to the assigned sex during infancy. AIM: The purpose of this study was to analyze the clinical management of an individual diagnosed as a female pseudohermaphrodite with congenital adrenal hyperplasia (CAH) simple virilizing form four decades ago but who currently lives as a monogamous heterosexual male. METHODS: We studied the clinical files spanning from 1965 to 1991 of an intersex individual. In addition, we conducted a magnetic resonance imaging (MRI) study of the abdominoplevic cavity and a series of interviews using the oral history method. MAIN OUTCOME MEASURES: Our analysis is based on the clinical evidence that led to the CAH diagnosis in the 1960s in light of recent clinical testing to confirm such diagnosis. RESULTS: Analysis of reported values for 17-ketosteroids, 17-hydroxycorticosteroids, from 24-hour urine samples during an 8-year period showed poor adrenal suppression in spite of adherence to treatment. A recent MRI study confirmed the presence of hyperplastic adrenal glands as well as the presence of a prepubertal uterus. Semistructured interviews with the individual confirmed a life history consistent with a male gender identity. CONCLUSIONS: Although the American Academy of Pediatrics recommends that XX intersex individuals with CAH should be assigned to the female sex, this practice harms some individuals as they may self-identify as males. In the absence of comorbid psychiatric factors, the discrepancy between infant sex assignment and gender identity later in life underlines the need for a reexamination of current standards of care for individuals diagnosed with CAH.


Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico , Hiperplasia Suprarrenal Congênita/metabolismo , Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/metabolismo , Identidade de Gênero , 17-Hidroxicorticosteroides/metabolismo , 17-Cetosteroides/metabolismo , Glândulas Suprarrenais/metabolismo , Hiperplasia Suprarrenal Congênita/classificação , Adulto , Diagnóstico Diferencial , Transtornos do Desenvolvimento Sexual/classificação , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Anamnese , Pessoa de Meia-Idade , Porto Rico
5.
Ultrasonics ; 41(8): 671-9, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14585479

RESUMO

A KLM model has been developed using equivalent circuits to analyze the effects of different loss mechanisms on the transducer performance in the time and frequency domain. Transducers from two different piezoelectric materials (lead-zirconate-titanate (PZT) and polyvinylidene fluoride) were constructed to validate our model. Experimental results are in good agreement with the theoretical simulation.


Assuntos
Transdutores , Ultrassom
6.
Ultrasonics ; 40(1-8): 819-21, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12160051

RESUMO

Two possible methods to determine the spatial average temporal average intensity I(sata) and ultrasonic power W in composite ltrasonic transducers for medical application are described. Results showed that integrals using one method will yield accurate results but a vast amount of computational effort is required. On the other hand, using an alternative method these integrals may readily be solved at the expense of the accuracy of the results deduced.


Assuntos
Ultrassonografia/métodos , Modelos Teóricos , Transdutores
8.
In. Madrid, Miguel de la; Soberón Acevedo, Guillermo; Ruiz Massieu, José Francisco; Kumate Rodríguez, Jesús; Martuscelli Quintana, Jaime; Sandoval Hernández, Sergio; Alvarez Manilla, José Manuel; Frenk Mora, Julio; González Block, Miguel Angel; Ruelas, Enrique; Ortega Lomelín, Roberto; Ruiz de Chávez, Manuel; Rivas Zivy, Enrique; Isaza Armella, Pablo; Arroyo Acevedo, Pedro; Granja Ricalde, Federico. La descentralización de los servicios de salud: el caso de México. s.l, Miguel Angel Porrúa, 1986. p.229-235.
Monografia em Espanhol | LILACS | ID: lil-30052

RESUMO

Son reconocidos algunos rasgos relevantes de la atención primaria de la salud, conteniendo definiciones jurídicas, políticas, administrativas y técnicas. Se consibe al modelo de atención constituído por tres componentes: necesidades de salud de la población, el contenido técnico de las acciones y la estructura misma de los servicios de salud. Son señaladas diversas críticas al modelo vigente, las cuales sirvieron como base para emprender medidas tendientes a producir cambios. El Estado adoptó 5 estrategias básicas para consolidar el Sistema Nacional de Salud: descentralización de los servicios; modernización técnico y administrativa; sectorización; coordinación intersectorial y promoción de la participación de la comunidad


Assuntos
Humanos , Atenção à Saúde/organização & administração , Política , México
9.
Salud pública Méx ; 26(6): 546-552, nov.-dic. 1984.
Artigo em Espanhol | LILACS | ID: lil-812

RESUMO

Se discute la eficiencia de la estrategia que se sigue para detectar personas con tuberculosis pulmonar activa. Se considera que las cifras de morbilidad que son generadas a partir de dicha estrategia subestiman la verdadera magnitud de la enfermedad como problema de salud pública. Se analiza cada una de las características que un enfermo de tuberculosis pulmonar debe reunir para la confirmación de la enfermedad, características que debido a la complejidad de los procesos que involucran determinan que unicamente dos de cada diez enfermos (en forma aproximada) sean diagnosticados; considerándose que el factor limitante más importante para esta pérdida de enfermos en el aspecto diagnóstico es la detección poblaciónal pasiva de tosedores. Se concluye que un conocimiento más real del problema, lo que significa un mejor planteamiento del mismo, se lograría por medio de la búsqueda activa de tosedores casa por casa en aquellos estratos de la población más expuestos a padecerla. La eficiencia de esta pesquisa aumentaría si se tomaran en cuenta los processos psicosociales y culturales que limitan la aceptación de los servicios de salud y que condicionan la autopercepción de los sujetos como portadores de una enfermedad estigmatizante


Assuntos
Tuberculose Pulmonar/diagnóstico , Tosse/epidemiologia , Acessibilidade aos Serviços de Saúde , Morbidade
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