ABSTRACT
Objetivo: Describir las aberraciones citogenéticas que pueden ser observadas por medio de la técnica Giemsa en fluorescencia y encontradas en pacientes con cáncer antes y después de ser sometidos a tratamiento con radioterapia. Métodos: Se analizó un mínimo de 200 metafases en primera división mitótica antes y después del tratamiento de radioterapia en nueve pacientes que asistieron a la sección de radioterapia del Hospital San Juan de Dios Costa Rica. En cada caso se contabilizó cada tipo de cromosomopatía por medio de la prueba de Giemsa en fluorescencia y utilizando bromodeoxiuridina y naranja de acridina. Resultados: Las cromosomopatías producidas por radioterapia se observaron tanto antes como después del tratamiento sin embargo destacó el incremento en la frecuencia de los cromosomas dicéntricos y anillos céntricos una vez finalizada la terapia. La frecuencia de fracturas cromatídicas de asociaciones satelíticas y de alteraciones morfológicas no se ve afectada por la radioterapia. Uno de los participantes presentó un recuento mitótico bajo. Conclusión: La radioterapia aumenta significativamente la frecuencia de los cromosomas dicéntricos y dicéntricos más anillos en la muestra en estudio. Este trabajo es relevante por ser el primer estudio en Costa Rica en el que se analizan los cromosomas dicéntricos como biomarcadores de exposición a radiaciones ionizantes mediante la prueba de Giemsa en fluorescencia y utilizando bromodeoxiuridina y naranja de acridina.
Aim: The objective of this study was to describe the before and after cytogenetic aberrations found in current patients of radiotherapy. This can be observed through the technique called "Giemsa in fluorescence" Methods: A minimum of 200 metaphases were analyzed in the first mitotic division in 9 patients. The patients where observed before and after radiotherapy treatment at the San Juan de Dios Hospital in Costa Rica. In each case any type of chromosomopathy was counted using the "Giemsa in fluorescence" test as well as Bromodeoxyuridine and acridine orange. Results: The chromosomopathies are observed before and after treatment with radiotherapy. The treatment seems to change the frecuency increasing the dicentric chromosomes and centric rings after the treatment. The frequency of chromatid fractures satellite associations and morphological alterations were not affected by radiotherapy. Conclusion: The chromosomopathies produced by radiotherapy were observed both before and after treatment with variations in their frequency. After radiotherapy dicentric chromosomes and dicentric chromosomes plus rings frequencies increased significantly. A low mitotic count was present this could have been the result of radiation on the bone marrow or by the cell repair and apoptosis system. The standardized " Fluorescence Plus Giemsa" test using Bromodesoxyuridine and acridine orange was used for the fiesta time in Costa Reica. This allowed for the measurement of radiation exposure used in the treatment or detection of diseases and cancer in pacients.
Subject(s)
Humans , Radiotherapy/statistics & numerical data , Ring Chromosomes , Cobalt/analysis , Neoplasms/radiotherapy , Radiation , Costa RicaABSTRACT
n este tercer y último artículo, estudiaremos los dos métodos de observación utilizados en la clínica odontológica: visual e instrumental. Para esto serán descritos las principales escalas e instrumentos utilizados en la selección cromática. También serán observadas las semejanzas y diferencias existentes entra la reproducción del color por técnica directa (con resinas compuestas) o por técnica indirecta (con sistemas cerámicos). Al final del artículo el lector podrá reconocer las indicaciones, ventajas y limitaciones de cada método.
n this third and final article, we will study the two methods of observation used in dental practice: visual and instrumental. The main scales and instruments used in color selection will be described. The similarities and differences between color reproduction by direct technique (composite resins) or by indirect technique (ceramic systems) will also be observed. At the end of the article the reader will be able to recognize the indications, advantages and limitations of each method.
ABSTRACT
Microbial siderophores confiscate the available ferric ions around the roots and trigger a reaction resulting in plant growth promotion. In our study, a high level of siderophore production was observed from a newly isolated Pseudomonas sp. from the rhizosphere of Chickpea plants. Under an iron depleted condition in Standard Succinic acid medium a 1000 µgmL-1 of siderophore production was achieved. Increasing the concentration of iron showed an inverse relationship between growth and siderophore production. Fourier Transform Infrared Spectroscopy (FTIR) analysis of the purified crystals, its UV spectral analysis and High Pressure Liquid Chromatography (HPLC) revealed the identity of the siderophore as similar to that of pyoverdin with distinctive characters. Electron spray ionization mass spectroscopy (ESIMS) shows presence of abundance of A1 ions (419 m/z) and branching of amino acids from B1-B5. This pyoverdin contains a cyclic tetra peptide but Serine and Arginine are missing. Based on our analysis and deviations from the reported structure of pyoverdin it is suggested that this pseudomonas produces distinctly characterized pyoverdin siderophore.