RESUMO
In this work two systems based on a carbohydrate polymer were studied: inulin as model system and inulin-orange juice as complex system. Both system were stored at different water activity conditions and subsequently characterized. Water adsorption isotherms type II were fitted by the GAB model and the water monolayer content was determined for each system. From thermal analyzes it was found that at low water activities (aw) systems were fully amorphous. As aw increased, crystallinity was developed. This behavior was corroborated by X-ray diffraction. In the inulin-orange juice system, crystallization appears at lower water activity caused by the intensification of the chemical interaction of the low molecular weight species contained in orange juice. Glass transition temperature (Tg), determined by modulated differential scanning calorimeter, decreased with aw. As water is adsorbed, the physical appearance of samples changed which could be observed by optical microscopy and effectively related with the microstructure found by scanning electron microscopy.
Assuntos
Fenômenos Químicos , Citrus sinensis , Inulina/química , Inulina/isolamento & purificação , Termogravimetria/métodos , Água/análise , Água/química , Difração de Raios XRESUMO
The glass transition temperature of model food systems prepared with several glucose/fructose/sucrose mass fractions was studied using differential scanning calorimetry (DSC). A distance-based experimental design for mixtures of 3 components was used to establish the proportion of sugars of the model systems. Thus, 32 compositions including individual sugars and sugar mixtures, both binary and ternary were prepared and analyzed. Thermograms showing the complete process of heating-cooling-reheating were used to determine the precise glass transition temperature during cooling (T(g)(c)) or reheating (T(g)(H) in amorphous sugars. The Scheffe cubic model was applied to experimental results to determine the influence of sugar composition on the glass transition temperature (P < 0.05). The final model proved to be appropriate (R(2) > 0.97, CV < 9%, model significance <0.0001) to predict the T(g) values of any dry mixture of amorphous fructose, glucose, and sucrose.
Assuntos
Tecnologia de Alimentos , Frutose/análise , Glucose/análise , Sacarose/análise , Temperatura de Transição , Varredura Diferencial de Calorimetria/métodos , Cristalização , Manipulação de Alimentos , Frutas/química , Modelos Teóricos , Análise de Regressão , Termodinâmica , Difração de Raios X/métodosRESUMO
OBJECTIVE: To evaluate the progress achieved in the treatment of acute lymphoblastic leukemia (ALL) in our hospital. MATERIAL AND METHODS: A total of 235 patients diagnosed with ALL in the central region of Cuba from 1972 to 2000 were included. Four groups were considered according to the diagnostic period and treatment protocol. Group 1 was composed of 20 patients who did not receive a uniform treatment regimen. The remaining groups were treated with different protocols of the Latin American Group for Malignant Hemopathy Therapy (Glathem). Group 2 was treated with less aggressive classical regimens from the 1970s, and groups 3 and 4 received more aggressive regimens, type Berlin-Frankfurt-Munster (BFM). Intravenous high-dose methotrexate was used in group 4 but not in group 3. Classification by prognostic groups was based on age and leukocyte count. RESULTS: Of 215 patients included in the Glathem protocols, remission occurred in 197 (91.6%). Overall survival in the distinct treatment groups progressively increased during the study period, from a 5-year survival of 15% in group 1 to 72% in group 4. Event-free survival in patients included in the Glathem protocols increased from 42% in group 2 (classical protocols) to 68.7% in the BFM protocols (groups 3 and 4). Significant differences were found among the different treatment and prognostic groups considered. CONCLUSIONS: During the period analyzed, survival in children with ALL progressively increased in parallel with improved treatment regimens. These results demonstrate the importance of well-programmed polychemotherapy to achieve prolonged survival and a high percentage of cure in this disease.
Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Pré-Escolar , Humanos , Lactente , Análise de SobrevidaRESUMO
Objetivo Analizar los progresos obtenidos en el tratamiento de la leucemia linfoblástica aguda (LLA) en nuestro centro. Material y métodos Se incluyen en este estudio un total de 235 pacientes diagnosticados de LLA en la región central de Cuba de 1972 a 2000. Se consideraron 4 grupos según el período de diagnóstico y protocolo de tratamiento. El grupo 1 está constituido por 20 pacientes que no recibieron un esquema de tratamiento uniforme. Los restantes grupos fueron tratados con distintos protocolos del Grupo Latinoamericano de Tratamiento de Hemopatías Malignas (Glathem). El grupo 2 fue tratado con esquemas clásicos poco agresivos, de la década de 1970 y los grupos 3 y 4 recibieron esquemas más agresivos, tipo BFM. En el grupo 4 se utilizó metotrexato intravenoso en dosis elevadas, pero no en el grupo 3. La clasificación por grupos pronósticos se hizo según a la edad y la cifra de leucocitos. Resultados De 215 pacientes incluidos en los protocolos del Glathem hicieron remisión 197 (91,6 por ciento). El análisis de la supervivencia global en los distintos grupos de tratamiento muestra un incremento progresivo en el período analizado, desde el 15 por ciento de supervivencia a los 5 años en el grupo 1 hasta el 72 por ciento en el grupo 4. La supervivencia libre de eventos en los pacientes incluidos en los protocolos del Glathem se elevó de 42 por ciento en el grupo 2 (protocolos clásicos) al 68,7 por ciento en los protocolos BFM (grupos 3 y 4). Existen diferencias significativas entre los distintos grupos de tratamiento y los distintos grupos pronósticos considerados. Conclusiones Durante el período analizado se ha producido un incremento progresivo de la supervivencia de niños diagnosticados de LLA a medida que se han ido perfeccionando los esquemas terapéuticos. Esto demuestra la importancia de una poliquimioterapia bien programada para obtener supervivencias prolongadas y un elevado porcentaje de curación en esta enfermedad(AU)
OBJECTIVE: To evaluate the progress achieved in the treatment of acute lymphoblastic leukemia (ALL) in our hospital. MATERIAL AND METHODS: A total of 235 patients diagnosed with ALL in the central region of Cuba from 1972 to 2000 were included. Four groups were considered according to the diagnostic period and treatment protocol. Group 1 was composed of 20 patients who did not receive a uniform treatment regimen. The remaining groups were treated with different protocols of the Latin American Group for Malignant Hemopathy Therapy (Glathem). Group 2 was treated with less aggressive classical regimens from the 1970s, and groups 3 and 4 received more aggressive regimens, type Berlin-Frankfurt-Munster (BFM). Intravenous high-dose methotrexate was used in group 4 but not in group 3. Classification by prognostic groups was based on age and leukocyte count. RESULTS: Of 215 patients included in the Glathem protocols, remission occurred in 197 (91.6 percent). Overall survival in the distinct treatment groups progressively increased during the study period, from a 5-year survival of 15percent in group 1 to 72 percent in group 4. Event-free survival in patients included in the Glathem protocols increased from 42 percent in group 2 (classical protocols) to 68.7percent in the BFM protocols (groups 3 and 4). Significant differences were found among the different treatment and prognostic groups considered. CONCLUSIONS: During the period analyzed, survival in children with ALL progressively increased in parallel with improved treatment regimens. These results demonstrate the importance of well-programmed polychemotherapy to achieve prolonged survival and a high percentage of cure in this disease(AU)