RESUMO
The presence of calcium oxalate (CaOx) crystals has been widely reported in the plant kingdom. These structures play a central role in various physiological functions, including calcium regulation, metal detoxification, and photosynthesis. However, precise knowledge about their possible roles and functions in plants is still limited. Therefore, the present work aims to study the ecotypic variability of Colobanthus quitensis, an extremophile species, concerning CaOx crystal accumulation. The CaOx crystals were studied in leaves of C. quitensis collected from different provenances within a latitudinal gradient (From Andes mountains in central Chile to Antarctica) and grown under common garden conditions. Polarized light microscopy, digital image analysis, and electron microscopy were used to characterize CaOx crystals. The presence of CaOx crystals was confirmed in the four provenances of C. quitensis, with significant differences in the accumulation among them. The Andean populations presented the highest accumulation of crystals and the Antarctic population the lowest. Electron microscopy showed that CaOx crystals in C. quitensis are classified as druses based on their morphology. The differences found could be linked to processes of ecotypic differentiation and plant adaptation to harsh environments.
RESUMO
Calcium oxalate (CaOx) crystals are widespread among plant species. Their functions are not yet completely understood; however, they can provide tolerance against multiple environmental stress factors. Recent evidence suggested that CaOx crystals function as carbon reservoirs since its decomposition provides CO2 that may be used as carbon source for photosynthesis. This might be advantageous in plants with reduced mesophyll conductance, such as the Antarctic plant Colobanthus quitensis, which have shown CO2 diffusion limitations. In this study, we evaluate the effect of two CO2 concentrations in the CaOx crystals decomposition and chlorophyll fluorescence of C. quitensis. Plants were exposed to airflows with 400 ppm and 11.5 ppm CO2 and the number and relative size of crystals, electron transport rate (ETR), and oxalate oxidase (OxO) activity were monitored along time (10 h). Here we showed that leaf crystal area decreases over time in plants with 11.5 ppm CO2, which was accompanied by increased OxO activity and only a slight decrease in the ETR. These results suggested a relation between CO2 limiting conditions and the CaOx crystals decomposition in C. quitensis. Hence, crystal decomposition could be a complementary endogenous mechanism for CO2 supply in plants facing the Antarctic stressful habitat.
RESUMO
Resumen Se presenta el caso de una femenina de 69 años con un carcinoma ductal in situ de la mama, el cual presentaba diferenciación apocrina y alto grado nuclear. La forma de presentación clínica se hizo patente en forma de microcalcificaciones detectadas en la mamografía, y corroboradas histológicamente como comedonecrosis. La diferenciación apocrina se comprobó por medio de tinciones de inmunohistoquímica. El diagnóstico se realizó en una biopsia excisional, pero dado a que uno de los márgenes se encontraba comprometido, la paciente se sometió posteriormente a una mastectomía.
Abstract We present the case of a 69 year old female diagnosed with a ductal in situ carcinoma of the breast. The tumor had apocrine differentiation and a high nuclear grade. The clinical presentation corresponded to microcalcifications detected on mammography, which were histologically patent in the form of comedo type necrosis. The aforementioned apocrine differentiation was reassured using the aid of immunohistochemistry. The biopsy was an excisional biopsy, but due to positive quirurgical margins, the patient was later reintervened for total mastectomy.
Assuntos
Humanos , Feminino , Idoso , Neoplasias da Mama , Receptores Androgênicos , Receptores de Progesterona , Receptores de Estrogênio , Carcinoma Ductal de Mama , Costa RicaRESUMO
Resumen:El porocarcinoma ecrino es un tipo muy poco frecuente de cáncer de piel, originado en la porción epidérmica de las glándulas sudoríparas ecrinas. Representa no más del 0.01% de los tumores cutáneos. El 20% de los porocarcinomas ecrinos son recurrentes y el 20% producen metástasis a ganglios linfáticos. Se ha reportado escasos casos de metástasis a distancia. Tiene un índice de mortalidad del 67% de los pacientes con metástasis.El diagnóstico es basado en los hallazgos histopatológicos y los estudios complementarios de inmunohistoquímica, a veces necesarios para el diagnóstico diferencial con otros tipos más frecuentes de cáncer de piel.No existen pruebas de que este tipo de carcinoma responda a la quimioterapia ni la radioterapia. Se considera que el manejo principal debe ser la resección quirúrgica y la electroquimioterapia.
Abstract:Eccrine porocarcinoma is a rare type of skin cáncer arising from the intraepidermal portion of eccrine sweat glands, representing no more tan 0.01% of all cutaneous tumors. 20% of the Eccrine porocarcinoma will recur and 20% will metastasize to regional lymph nodes. Few cases of distant metastases has been reported . There is a mortality rate of 67% in patients with metastases. The diagnosis is primarily based on histopathologic findings and complementary immunohistochemistry for differential diagnosis mainly with more frequent skin cáncer.Neither chemotherapy nor radiation therapy has been proven to be of clinical benefit in treating this type of carcinoma. It is considered that the management should be based on surgical resection and electrochemotherapy.
Assuntos
Humanos , Neoplasias das Glândulas Sudoríparas , Glândulas Sudoríparas , Poroma , Porocarcinoma ÉcrinoRESUMO
Se presenta un caso de divertículo del apéndice cecal verdadero en un paciente masculino de 38 años de edad, diagnosticado inicialmente como plastrón apendicular. Se destaca la rareza de dicha patología, la presentación clínica superponible con cuadro de apendicitis y su curación mediante la apendicectomía así como su diagnóstico anatomopatológico en la gran mayoría de los casos
