RESUMEN
Since our experimental results suggest that UT-B1 functions as active water transporter against osmotic gradient in C6 glial cells, we report here for the first time the evidence for the active water transport. Exposure of C6 cells to a hyperosmotic solution containing glycerol or sucrose produced cell shrinkage due to water efflux according to osmotic gradient for water movement. On the other hand, C6 cells show cell swelling against osmotic gradient for water movement just after exposure to a hyperosmotic solution containing urea, indicating that water influx against osmotic gradient for water movement is accelerated by urea; i.e., urea performs active water transport. A specific inhibitor of UT-B, pCMBS, blocked the urea-induced swelling. The urea-induced cell swelling was significantly suppressed in the siRNA-induced UT-B1-knockdown C6 cells. Taken together, these observations indicate that UT-B1 acts as an active water transporter, providing a new model on active water transport.
Asunto(s)
Agua Corporal/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Neuroglía/metabolismo , Urea/metabolismo , Equilibrio Hidroelectrolítico/fisiología , Agua/metabolismo , Animales , Línea Celular , Tamaño de la Célula , Ratas , Transportadores de UreaRESUMEN
Of the several kinds of therapy-related leukemia, therapy-related acute promyelocytic leukemia (t-APL) is most closely associated with topoisomerase II inhibitor administration for treatment of malignancies in adults. Although rare in children, the majority of therapy-related malignancies have been etoposide-related APL associated with Langerhans cell histiocytosis. The authors describe the development of t-APL after chemotherapy administered for non-Hodgkin's lymphoma (NHL) in an 8-year-old girl. One month after cessation of the 3-year chemotherapy regimen of doxorubicin and other agents but not etoposide or radiotherapy, the patient was diagnosed with t-APL with positive PML-RARA molecular abnormality. The patient attained a complete remission following treatment with all-trans retinoic acid-containing chemotherapy. Thereafter, she successfully received hematopoietic stem cell transplantation from an HLA-matched sibling donor. Development of t-APL associated with NHL in children appears to be rare.
Asunto(s)
Antineoplásicos/efectos adversos , Leucemia Promielocítica Aguda/patología , Linfoma no Hodgkin/patología , Neoplasias Primarias Secundarias/patología , Médula Ósea/patología , Trasplante de Médula Ósea , Preescolar , Cromosomas Humanos Par 15 , Cromosomas Humanos Par 17 , Femenino , Humanos , Linfoma no Hodgkin/tratamiento farmacológico , Neoplasias Primarias Secundarias/terapia , Reacción en Cadena de la Polimerasa , Inducción de Remisión , Translocación GenéticaRESUMEN
This article reports early blastic transformation of chronic myeloid leukemia (CML) in a child following a complete cytogenetic response induced by imatinib mesylate. A 14-year-old Japanese boy was diagnosed with t(9;22) cryptic CML in the chronic phase and treated with imatinib. His response to treatment was slow, but a major cytogenetic response was obtained at 142 days of therapy. However, he developed lymphoid blastic transformation at 9 months. He attained remission with acute lymphoblastic leukemia-type chemotherapy and then successfully received a non-T-cell-depleted allogeneic stem cell transplantation (allo-SCT) with his mother's two loci-mismatched donor cells. A sudden blastic transformation may occur even with a complete cytogenetic response induced by imatinib. CML patients who respond slowly to imatinib may still be candidates for allo-SCT, even when a major cytogenetic response is obtained.
Asunto(s)
Crisis Blástica/terapia , Leucemia Mieloide de Fase Crónica/tratamiento farmacológico , Activación de Linfocitos , Piperazinas/uso terapéutico , Pirimidinas/uso terapéutico , Adolescente , Benzamidas , Crisis Blástica/etiología , Análisis Citogenético , Supervivencia sin Enfermedad , Trasplante de Células Madre Hematopoyéticas , Histocompatibilidad , Humanos , Mesilato de Imatinib , Leucemia Mieloide de Fase Crónica/terapia , Masculino , Recurrencia , Inducción de Remisión/métodos , Trasplante HomólogoRESUMEN
A patient with Williams syndrome, craniosynostosis, and infantile spasms is described. At age 6 months, the infant demonstrated infantile spasms and craniosynostosis and was operated on for craniosynostosis and treated with adrenocorticotropic hormone (ACTH) for the infantile spasms. ACTH completely controlled the seizures, but was halted because of the progression of ventricular hypertrophy. The seizure returned, and he was found to have elfin face, failure-to-thrive, developmental delay, and dental malformation in addition to congenital heart defects. High-resolution chromosome analysis revealed interstitial deletion of 7q11.22-q11.23. Therefore his clinical and cytogenetic diagnosis was Williams syndrome. Thyrotropin-releasing hormone (TRH) therapy reduced his seizures and improved the findings of EEG without cardiac side effects. In addition, his psychomotor development was slightly improved.