122 research outputs found
Anatomía microscópica normal de la glándula tiroides. Principios básicos para el residente de Endocrinología y anatomía patológica con una breve nota histórica
Contexto: es necesario conocer las características histológicas normales de la glándula tiroides para comprender los
procesos patológicos de esta glándula.
Objetivo: esta es una revisión práctica sobre la estructura normal de la glándula tiroides, dirigida a residentes de Endocrinología y anatomía patológica.
Metodología: se realizó una búsqueda bibliográfica sobre la histología normal de la glándula tiroides y se utilizó material
histológico del Departamento de Patología del Hospital Médica Sur (México).
Resultados: la glándula tiroides normal está formada por dos lóbulos laterales conectados centralmente por un istmo.
Esta glándula es color marrón clara y de consistencia firme, con un peso de 15 a 25 g. Aproximadamente en el 80 % de
los individuos existe un lóbulo piramidal que se extiende hacia arriba desde el istmo a lo largo de la superficie anterior
del cartílago tiroides. Este lóbulo es un remanente del conducto tirogloso. Histológicamente, la tiroides está formada por numerosos folículos esféricos con un diámetro promedio de 200 ?m. Cada folículo está revestido por células epiteliales
planas, cuboidales o cilíndricas y tiene en el centro coloide secretado por las células epiteliales, bajo la influencia de la hormona estimulante de la tiroides. Existe un segundo grupo de células, las células C o células parafoliculares, ubicadas principalmente en los polos superiores de los lóbulos tiroideos, que secretan calcitonina.
Conclusiones: En la glándula tiroides se presentan diversos procesos patológicos por lo que es importante conocer su estructura normal para interpretar adecuadamente cada proceso
Infantile systemic juvenile xanthogranuloma case with massive liver infiltration
Infantile systemic juvenile xanthogranuloma (ISJXG) is an uncommon form of juvenile xanthogranuloma, a non-Langerhans cell proliferation of infancy and early childhood. In a small percentage of patients, the visceral involvement—most commonly to the central nervous system, liver, spleen, or lungs—may be associated with severe morbidity, and eventually fatal outcome. Here we describe the clinical and pathological findings of a 28-day-old girl with ISJXG who died with respiratory distress syndrome. She had few cutaneous lesions but massive liver and spleen infiltration; other affected organs were multiple lymph nodes, thoracic parasympathetic nodule, pleura, pancreas, and kidneys. Additional findings were mild pulmonary hypoplasia and bacteremia. Immunohistochemistry on fixed tissues is the standard for diagnosis. Immunophenotype cells express CD14, CD68, CD163, Factor XIIIa, Stabilin-1, and fascin; S100 was positive in less than 20% of the cases; CD1a and langerin were negative. No consistent cytogenetic or molecular genetic defect has been identified. This case demonstrates that the autopsy is a handy tool, because hepatic infiltration, which was not considered clinically, determined a restrictive respiratory impairment. In our opinion, this was the direct cause of death
Characterization of the global profile of genes expressed in cervical epithelium by Serial Analysis of Gene Expression (SAGE)
BACKGROUND: Serial Analysis of Gene Expression (SAGE) is a new technique that allows a detailed and profound quantitative and qualitative knowledge of gene expression profile, without previous knowledge of sequence of analyzed genes. We carried out a modification of SAGE methodology (microSAGE), useful for the analysis of limited quantities of tissue samples, on normal human cervical tissue obtained from a donor without histopathological lesions. Cervical epithelium is constituted mainly by cervical keratinocytes which are the targets of human papilloma virus (HPV), where persistent HPV infection of cervical epithelium is associated with an increase risk for developing cervical carcinomas (CC). RESULTS: We report here a transcriptome analysis of cervical tissue by SAGE, derived from 30,418 sequenced tags that provide a wealth of information about the gene products involved in normal cervical epithelium physiology, as well as genes not previously found in uterine cervix tissue involved in the process of epidermal differentiation. CONCLUSION: This first comprehensive and profound analysis of uterine cervix transcriptome, should be useful for the identification of genes involved in normal cervix uterine function, and candidate genes associated with cervical carcinoma
Mejoramiento de material granular con cemento tipo MH y agregados finos de arena de playa proveniente de la costa en la provincia Manabí
The present investigation was developed with the purpose of characterizing the sea sands of the beaches located in the coastal profile of the province of Manabí, to determine if it is feasible to combine it with sub-base type granular material, fulfilling the specification of INEN standards for civil works projects. The sea sand studied underwent granulometry, natural humidity and specific gravity tests to later combine it granulometrically with the sub-base type granular material from a quarry located in the canton of Montecristi. The dosage to stabilize the sub-base was developed using 10% sea sand from Puerto Cayo adding 3, 4 and 5% Holcim Base Vial Type MH cement. To analyze the mechanical behavior of this type of mixtures, Modified Proctor and CBR (California Bearing Ratio) tests were carried out, which allowed us to show favorable results regarding the resistant capacity of the sub-base type granular material, since by adding 10% of sea sand from Puerto Cayo and 5% MH type cement, the CBR of the quarry granular material, significantly increased reaching values from 33.2% to 150%.
Keywords: Sea sand, Granular sub-base, Granulometry, California Bearing Ratio (CBR), Type MH Cement.La presente investigación se desarrolló con el propósito de caracterizar las arenas de mar de las playas ubicadas en el perfil costero de la provincia de Manabí, para determinar si es factible su uso en la combinación con material granular tipo sub-base cumpliendo con las especificaciones de las normas del INEN para proyectos de obras civiles. A la arena de mar estudiada se le realizaron ensayos de granulometría, humedad natural y gravedad específica para posteriormente combinarla granulométricamente con el material granular tipo sub-base proveniente de una cantera ubicada en el cantón de Montecristi. La dosificación para estabilizar la sub-base se desarrolló empleando 10% de arena de mar de Puerto Cayo añadiendo 3, 4 y 5% de cemento Holcim Base Vial Tipo MH. Para analizar el comportamiento mecánico de este tipo de mezclas, se realizaron ensayos de Proctor Modificado y CBR (California Bearing Ratio) que permitieron evidenciar resultados favorables con respecto a la capacidad resistente del material granular tipo sub-base ya que al añadirle un 10% de arena de mar de Puerto Cayo y 5% de cemento tipo MH, aumentó significativamente el CBR del material granular de cantera, alcanzando valores de 33.2% al 150%.
Palabras clave: Arena de mar, Sub-base granular, Granulometría, Capacidad Portante de Suelo (CBR), Cemento Tipo MH.
Abstract
The present investigation was developed with the purpose of characterizing the sea sands of the beaches located in the coastal profile of the province of Manabí, to determine if it is feasible to combine it with sub-base type granular material, fulfilling the specification of INEN standards for civil works projects. The sea sand studied underwent granulometry, natural humidity and specific gravity tests to later combine it granulometrically with the sub-base type granular material from a quarry located in the canton of Montecristi. The dosage to stabilize the sub-base was developed using 10% sea sand from Puerto Cayo adding 3, 4 and 5% Holcim Base Vial Type MH cement. To analyze the mechanical behavior of this type of mixtures, Modified Proctor and CBR (California Bearing Ratio) tests were carried out, which allowed us to show favorable results regarding the resistant capacity of the sub-base type granular material, since by adding 10% of sea sand from Puerto Cayo and 5% MH type cement, the CBR of the quarry granular material, significantly increased reaching values from 33.2% to 150%.
Keywords: Sea sand, Granular sub-base, Granulometry, California Bearing Ratio (CBR), Type MH Cement.
Información del manuscrito:Fecha de recepción: 09 de diciembre de 2022.Fecha de aceptación: 03 de febrero de 2023.Fecha de publicación: 27 de febrero de 2023
Nuevos datos cronoestratigráficos de la Fm. Marismas (Bajo Guadalquivir)
La Formación Marismas forma la parte superior del relleno sedimentario del sector SW de la cuenca del Guadalquivir. Los datos previos sobre el sondeo Lebrija, indicaban que la parte más alta de esta formación tenía edades de hasta 9.6 kyr BP y en la parte inferior eran cercanas o fuera del rango del radiocarbono, pero posterior a la reversión
Brunhes-Matuyama. En este trabajo se aportan 17 nuevas dataciones realizadas mediante racemización de aminoácidos en valvas de ostrácodos en este mismo sondeo, con el fin de
completar la cronología y el modelo de edad de la parte superior e inferior de la Fm Marismas. El resultado indica que el tramo situado por debajo del metro 56, arroja edades
que oscilan entre 164685±14110 y 202830±30255, que se correlacionan con los estadios isotópicos marinos MIS 6-7 del Pleistoceno medio, edad sensiblemente más baja a las inferidas para esta formación en otros puntos de la Cuenca del bajo GuadalquivirEste trabajo se ha realizado dentro del proyecto Guadaltyc (Impacto del clima y la tectónica en el registro sedimentario de la Cuenca del Guadalquivir, (CGL2012-30875).Peer Reviewe
Las tobas cuaternarias del río Añamaza (provincia de Soria, Cordillera Ibérica): aproximación cronológica
High-gradient, stepped fluvial tufa systems with dammed areas existed in the River Añamaza valley (NW Iberian Ranges, Spain) during Quaternary times. Single deposits range from a few meters to about 70 m thick, in which prograding-aggrading wedges separated by erosional surfaces exist. Several episodes of tufa formation have been distinguished by means of U-series, Amino-acid racemization and radiocarbon techniques. These correlate to MIS 8, 7, 5 and 1. The presence of MIS 9 is uncertain, as chronological data may also correspond to older stages. Most tufas in this area formed in MIS 5. Distinct tufa episodes can also be distinguished in the Holocene. These are the first chronological data presented for one of the northernmost Quaternary tufa systems in the Iberian Ranges
Thermal and non-thermal effects off capacitive-resistive electric transfer application on the achilles tendon and musculotendinous junction of the gastrocnemius muscle: a cadaveric study
Background Calf muscle strain and Achilles tendon injuries are common in many sports. For the treatment of muscular and tendinous injuries, one of the newer approaches in sports medicine is capacitive-resistive electric transfer therapy. Our objective was to analyze this in vitro, using invasive temperature measurements in cadaveric specimens.
Methods A cross-sectional study designed with five fresh frozen cadavers (10 legs) were included in this study. Four interventions (capacitive and resistive modes; low- and high-power) was performed for 5¿min each by a diathermy “T-Plus” device. Achilles tendon, musculotendinous junction and superficial temperatures were recorded at 1-min intervals and 5¿min after treatment.
Results With the low-power capacitive protocol, at 5¿min, there was a 25.21% increase in superficial temperature, a 17.50% increase in Achilles tendon temperature and an 11.27% increase in musculotendinous junction temperature, with a current flow of 0.039 A¿±¿0.02.
With the low-power resistive protocol, there was a 1.14% increase in superficial temperature, a 28.13% increase in Achilles tendon temperature and an 11.67% increase in musculotendinous junction temperature at 5¿min, with a current flow of 0.063 A¿±¿0.02. With the high-power capacitive protocol there was an 88.52% increase in superficial temperature, a 53.35% increase in Achilles tendon temperature and a 39.30% increase in musculotendinous junction temperature at 5¿min, with a current flow of 0.095 A¿±¿0.03. With the high-power resistive protocol, there was a 21.34% increase in superficial temperature, a 109.70% increase in Achilles tendon temperature and an 81.49% increase in musculotendinous junction temperature at 5¿min, with a current flow of 0.120 A¿±¿0.03.
Conclusion The low-power protocols resulted in only a very slight thermal effect at the Achilles tendon and musculotendinous junction, but current flow was observed. The high-power protocols resulted in a greater temperature increase at the Achilles tendon and musculotendinous junction and a greater current flow than the low-power protocols. The high-power resistive protocol gave the greatest increase in Achilles tendon and musculotendinous junction temperature. Capacitive treatments (low- and high-power) achieved a greater increase in superficial temperature
Análisis preliminar de las tobas cuaternarias del río Ebrón (Castielfabib, Valencia, Cordillera Ibérica)
In this paper the Alpine cleavage affecting the Permo-Triassic series of the Espadan Range (Castellón) is studied. Cleavage affects to argillites and sandstones in Saxonian and Buntsandstein facies. At cartographic scale it is linked with the Espadan box anticline with constant ONO-ESE trend. At microscoscopic scale it constitutes a “spaced cleavage” with a predominance of pressure solution and passive rotation mechanisms. At outcrop scale the cleavage characterizes by a sigmoidal geometry linked both the post-cleavage flexural slip as a cleavage-related flexural flow mechanism. The proposed kinematic model to explain its origin includes three main stages: 1) incipient development of cleavage linked to layer-parallel shortening, 2) buckling and increasing of cleavage penetrativity and 3) folfing amplification and layer-parallel shear. RESUMEN Se estudia la esquistosidad alpina que afecta a la serie Permo-Triásica de la Sierra de Espadán, (Castellón). La esquistosidad afecta a los tramos argilíticos y areniscosos en facies Saxoniense y Buntsandstein, con distinto grado de penetratividad. A escala cartográfica se asocia al anticlinal de Espadán con geometría en cofre y orientación ONO-ESE. A escala microestructural se clasifica como esquistosidad espaciada con predominio de los mecanismos de disolución por presión y rotación mecánica de filosilicatos. A escala de afloramiento destaca la geometría sigmoidal de las superficies de esquistosidad atribuida tanto a un mecanismo post-esquistoso de flexodeslizamiento en las capas competentes como a flexofluencia sin-esquistosa en capas incompetentes. El modelo cinemático para su génesis contempla tres estadios: 1) desarrollo incipiente de esquistosidad en relación a acortamiento paralelo a las capas, 2) buckling e incremento del grado de penetratividad y 3) amplificación de los pliegues y cizalla simple paralela a las capa
Ensayo cronológico de las tobas cuaternarias del río Piedra (Cordillera Ibérica)
A preliminary absolute chronology for the Quaternary calcareous tufa deposits from the Piedra River valley (Iberian Range, NE Spain) has been carried out based on U series dating, Amino Acid Racemization, Optically Stimulated Luminescence and Radiocarbon dating techniques. Although the age uncertainties of the obtained dates are substantial, four stages of tufa accumulation correlated to MIS 9, 7-6, 5 and 1 can be distinguished. The most favourable period for tufa accumulation is located around the isotopic stage
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