RESUMEN
This work aims to study the pathogenesis of learning and memory impairment in offspring rats resulting from maternal enflurane anesthesia by focusing on the expression of the N-methyl-d-aspartic acid receptor subunit 2B (NR2B) in the hippocampus of the offspring. Thirty female Sprague-Dawley rats were randomly divided into three groups: control (C group), 4 h enflurane exposure (E1 group), and 8 h enflurane exposure (E2 group) groups. Eight to ten days after the initiation of pregnancy, rats from the E1 and E2 groups were allowed to inhale 1.7% enflurane in 2 L/min oxygen for 4 h and 8 h, respectively. Rats from the C group were allowed to inhale 2 L/min of oxygen only. The Morris water maze was used to assay the learning and memory function of the offspring on postnatal days 20 and 30. RT-PCR and immunohistochemistry assays were then used to measure the mRNA levels and protein expression of NR2B, respectively. Relative to offspring rats from the C group, those from the E1 and E2 groups exhibited longer escape latencies, lesser number of crossings over the platform, and less time spent in the target quadrant in the spatial exploration test (P < 0.05). In addition, the mRNA and protein expression levels of NR2B in the hippocampus of offspring rats in the E1 and E2 groups were down-regulated (P < 0.05). No significant differences between the E1 and E2 groups were observed (P > 0.05) in terms of mRNA levels and protein expression of NR2B. The cognitive function of the offspring is impaired when maternal rats are exposed to enflurane during early pregnancy. A possible mechanism of this effect is related to the down-regulation of NR2B expression.
Este trabalho objetiva o estudo da patogênese de deficiência no aprendizado e memória de prole de ratos resultante da anestesia maternal por enflurano, por meio da expressão da subunidade 2B do receptor do ácidoN-metil-D-aspártico (NR2B) no hipocampo dos filhotes. Dividiram-se, aleatoriamente, 30 fêmeas de ratos Sprague-Dawley em três grupos: controle (grupo C), exposição ao enflurano por 4 h (grupo E1) e por 8 h (grupo E2). De oito a 10 dias após o início da gravidez, os ratos dos grupos E1 e E2 inalaram enflurano 1,7% em 2 L/min de oxigênio, por 4 h e 8 h, respectivamente. Ratos do grupo C inalaram apenas 2 L/min de oxigênio. O labirinto de água de Morris foi empregado para analisar as funções de aprendizado e memória da cria em 20 e 30 dias após o nascimento. Utilizaram-se ensaios de RT-PCR e de imuno-histoquímica para medir os níveis de mRNA e expressão da proteína do NR2B, respectivamente. Em comparação com os ratos controle do grupo C, aqueles dos grupos E1 e E2 exibiram latências de escape mais longas, menor número de travessias na plataforma e menos tempo gasto no quadrante alvo no teste de exploração espacial (P < 0,05). Adicionalmente, os níveis de expressão de mRNA e de proteína do NR2B no hipocampo dos filhotes nos grupos E1 e E2 estavam reduzidos (P < 0,05). Não se observaram diferenças significativas entre os grupos E1 e E2 (P < 0,05) quanto aos níveis de mRNA e à expressão de proteína de NR2B. A função cognitiva dos filhotes é prejudicada quando as mães são expostas ao enflurano durante o início da gravidez. O mecanismo possível para esse efeito está relacionado à diminuição na expressão de NR2B.
Asunto(s)
Ratas , Embarazo , Exposición Materna/clasificación , Enflurano/análisis , Expresión Génica/inmunología , N-Metilaspartato/análisis , AnestesiaRESUMEN
INTRODUCTION: This study retrospectively compared outcomes and prognostic factors of nasopharyngeal carcinoma (NPC) treated with conformal radiotherapy (CRT) and intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: The treatment records of 182 patients treated with IMRT and 198 patients treated with CRT from April 2005 to December 2007 in our hospital were reviewed. The clinical characteristics, treatment outcomes (including survival analysis and acute and late toxicity), and prognostic factors of the two groups were compared. RESULTS: The 4-year local-regional control (LRC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) of the IMRT and CRT groups were 93.6 and 85.3 %, 79.1 and 73.6 %, 74.7 and 65.0 %, and 83.5 and 72.1 %, respectively. The acute radiation dermatitis and xerostomia of the two groups were significantly different (P < 0.05). In the IMRT group, OS between different T stages could not be well separated. Multivariate analysis revealed that, in the CRT group, the clinical stage and T and N stages were significant prognostic factors for OS, DMFS, and DFS and that T stage was a significant prognostic factor for LRC. In the IMRT group, T and N stages had no predictive value for outcomes. CONCLUSIONS: Compared with CRT, IMRT has a better prognosis and less adverse effects. For IMRT, T stage was not a significant prognostic factor for LRC, DMFS, DFS, or OS. An effective treatment strategy is needed for distant control. With the increasing use of IMRT and continued modulation of treatment strategies for NPC, the current staging system faces great challenges.