RESUMEN

OBJECTIVE: Accurate visual classification of bladder tissue during Trans-Urethral Resection of Bladder Tumor (TURBT) procedures is essential to improve early cancer diagnosis and treatment. During TURBT interventions, White Light Imaging (WLI) and Narrow Band Imaging (NBI) techniques are used for lesion detection. Each imaging technique provides diverse visual information that allows clinicians to identify and classify cancerous lesions. Computer vision methods that use both imaging techniques could improve endoscopic diagnosis. We address the challenge of tissue classification when annotations are available only in one domain, in our case WLI, and the endoscopic images correspond to an unpaired dataset, i.e. there is no exact equivalent for every image in both NBI and WLI domains. METHOD: We propose a semi-surprised Generative Adversarial Network (GAN)-based method composed of three main components: a teacher network trained on the labeled WLI data; a cycle-consistency GAN to perform unpaired image-to-image translation, and a multi-input student network. To ensure the quality of the synthetic images generated by the proposed GAN we perform a detailed quantitative, and qualitative analysis with the help of specialists. CONCLUSION: The overall average classification accuracy, precision, and recall obtained with the proposed method for tissue classification are 0.90, 0.88, and 0.89 respectively, while the same metrics obtained in the unlabeled domain (NBI) are 0.92, 0.64, and 0.94 respectively. The quality of the generated images is reliable enough to deceive specialists. SIGNIFICANCE: This study shows the potential of using semi-supervised GAN-based bladder tissue classification when annotations are limited in multi-domain data.

Asunto(s)

RESUMEN

PURPOSE: Ureteroscopy is an efficient endoscopic minimally invasive technique for the diagnosis and treatment of upper tract urothelial carcinoma. During ureteroscopy, the automatic segmentation of the hollow lumen is of primary importance, since it indicates the path that the endoscope should follow. In order to obtain an accurate segmentation of the hollow lumen, this paper presents an automatic method based on convolutional neural networks (CNNs). METHODS: The proposed method is based on an ensemble of 4 parallel CNNs to simultaneously process single and multi-frame information. Of these, two architectures are taken as core-models, namely U-Net based in residual blocks ([Formula: see text]) and Mask-RCNN ([Formula: see text]), which are fed with single still-frames I(t). The other two models ([Formula: see text], [Formula: see text]) are modifications of the former ones consisting on the addition of a stage which makes use of 3D convolutions to process temporal information. [Formula: see text], [Formula: see text] are fed with triplets of frames ([Formula: see text], I(t), [Formula: see text]) to produce the segmentation for I(t). RESULTS: The proposed method was evaluated using a custom dataset of 11 videos (2673 frames) which were collected and manually annotated from 6 patients. We obtain a Dice similarity coefficient of 0.80, outperforming previous state-of-the-art methods. CONCLUSION: The obtained results show that spatial-temporal information can be effectively exploited by the ensemble model to improve hollow lumen segmentation in ureteroscopic images. The method is effective also in the presence of poor visibility, occasional bleeding, or specular reflections.

Asunto(s)

RESUMEN

The identification system of spermatogonial stem cell (SSC) was established in alpaca using the molecular expression as well as the reactivity pattern to Dolichos biflorus agglutinin (DBA) by flow cytometry. Twenty-four testicles with their epididymis were recovered from adult alpacas at the slaughterhouse of Huancavelica-Perú. Samples were transported to the Laboratory of Reproductive Physiology at Universidad Nacional Mayor de San Marcos. Testes were selected for our study when the progressive motility of epididymal spermatozoa (ESPM) was above 30%. Isolation of SSC was performed with two enzymatic digestions. Finally, sperm viability was evaluated by means of the trypan blue vital stain in spermatogonial round cells. Samples with more than 80% viability were selected. Isolated cells cultured for 2 days were used for identifying the presence of SSCs by the expression of integrin ß1 (116 bp) and PLZF (206 bp) genes. Spermatogonia were classified according to the DBA reactivity. Spermatogonia with a strong positive to DBA (sDBA+ ) were classified as SSC (Mean ± SEM=4.44 ± 0.68%). Spermatogonia in early differentiation stages stained weakly positive with DBA (wDBA+ ) (Mean ± SEM=37.44 ± 3.07%) and differentiated round cells as DBA negative (Mean ± SEM=54.12 ± 3.18%). With the use of molecular and DBA markers, it is possible to identify easily the spermatogonial stem cells in alpaca.

Asunto(s)

RESUMEN

La estenosis aórtica severa sintomática secundaria a calcificación degenerativa constituye un reto terapéutico si el paciente no es tributario de tratamiento quirúrgico de reemplazo valvular. La colocación de un implante valvular aórtico transcatéter (TAVI) es una alternativa terapéutica para estos casos. Se presenta el caso de un varón de 78 años con antecedentes de hipertensión arterial, enfermedad renal crónica (estadio IIIa), tabaquismo pesado, portador de marcapaso definitivo, enfermedad arterial periférica y policitemia vera. A la evaluación, el paciente cursaba con una disnea de clase III (escala NYHA) desde hace un año. El ecocardiograma transtorácico mostró calcificación severa de velos aórticos, una fracción de eyección ventricular izquierda de 44,7% y un área valvular de 0,58 cm2 (0,31 cm2/m2); la angiografía mostró enfermedad arterial coronaria moderada y la angiotomografía una calcificación severa de la aorta torácica ('aorta en porcelana'). Por considerarlo de alto riesgo, se realizó colocación de TAVI por vía transapical (válvula bioprotésica Braile Biomédica N° 30), con controles ecocardiográficos satisfactorios. El caso que presentamos constituye el primero realizado en el norte del país

Severe symptomatic aortic stenosis secondary to degenerative calcification may be a real therapeutic challenge if the patient does not undergo an aortic valve replacement. Transapical transcatheter aortic valve replacement is a valid therapeutic option for these cases. We present the case of a 78-year old male with the following past and current medical history: high blood pressure, chronic kidney disease (stage IIIa), heavy tobacco smoking, use of a permanent pacemaker, peripheral arterial disease, and polycythemia vera. When assessed, the patient had had class III heart failure (NYHA classification) for one year. Transthoracic ultrasonography showed severe calcification of the aortic cusps, a 44.7% left ventricular ejection fraction, and a 0.58 cm2 (0.31 cm2/m2) valve surface area. Angiography showed moderate coronary heart disease, and angiotomography showed severe calcification of the aortic valve ('porcelain aorta'). Since this patient was considered at high-risk, a transapical transcatheter aortic valve replacement was performed (Braille Biomedical N° 30 bioprosthetic valve), and the ultrasonography controls showed satisfactory results. This case is the first procedure of its kind performed in Northern Peru

RESUMEN

Con el presente trabajo se pretende aportar una descripción de las características, del tratamiento de este tipo de trastornos. Se realiza una breve revisión acerca de las consideraciones sintomáticas y signológicas de este trastorno, así como de su tratamiento; para ello se encuesta 19 historias clínicas cuyo diagnóstico corresponde a un desorden Insidioso del desarrollo o específicamente de un síndrome autista. Los niños son frecuentemente varones, consultan alrededor de los 3 años, asisten por dificultades en el lenguaje e hiperactividad. los síntomas más frecuentes son: movimientos estereotipados, aislamiento, falta de contacto, risas inmotivadas, hiperactividad. El tratamiento más frecuentemente utilizado es a base de psicofármacos, neurofármacos. En otros casos, derivados a educación especial, ergoterapia y psicomotricidad

Asunto(s)

RESUMEN

Se realiza una revisión breve de las diferentes formas de intervenciones terapéuticas en Psiquiatría Infantil; del mismo modo se recuerdan algunas de las indicaciones y cómo influyen en el niño

Asunto(s)

RESUMEN

Se presenta una revisión bibliográfica de las publicaciones que se han realizado de la psiquiatría militar en el medio, todos aquellos aspetos que estuvieran relacionados con la clínica ó la epidemiología y que se hubieran realizado en los diferentes Hospitales de las Fuerzas Armadas y de la Sanidad de las Fuerzas Policiales, son revisados, comentados y comparados con otros estudios. Se relieva la necesidad de orientar la investigación clínica y epidemiológica en el ámbito de la psiquiatría militar

Asunto(s)

RESUMEN

Se presentan las características más destacadas de 85 pacientes que son motivos de interconsulta psiquiátrica en el Centro de Patología del Lenguaje del Hospital Central de la Sanidad de las Fuerzas Policiales

Asunto(s)

RESUMEN

En el presente artículo se presenta una breve revisión de las indicaciones y de las dosis de los psicofármacos utilizados en los niños. Las indicaciones de los psicofármacos se analizan en función de síndromes infantiles diversos. Las dosis que se incluyen son aquellas recomendadas por diversos autores y especialistas

Asunto(s)

RESUMEN

Se pusieron a consideración de 30 psiquiatras de prestigio, muy familiarizados con los problemas de dependencia a drogas, un listado de síntomas y signos a fin de que se pronunciaran acerca de sus criterios para llegar al diagnóstico de dependencia a PBC. Se recibió respuesta del 80% de ellos, quienes identificaron síntomas, conductas generales y otros criterios decisivos para el diagnóstico de dependencia a PBC

Asunto(s)