Comparison of cytopathic changes in oral hairy leukoplakia with in situ hybridization for EBV DNA

OBJECTIVE: It has been observed that the cytopathic changes in hairy leukoplakia (HL) correlate with ultra-structural evidence of intra-keratinocyte herpes-type viral particles. In situ hybridization is considered to be the definitive confirmation of Epstein-Barr virus (EBV)-induced HL. This study evaluated the consistency of histopathological findings, which many believe to be diagnostic, with in situ hybridization for EBV-DNA in 60 patients with lesions clinically suggestive of HL.
MATERIALS AND METHODS: Hematoxylin and eosin (H&E)-stained sections were reviewed independently by three oral pathologists who did not know the hybridization results. The presence in keratinocytes of nuclear inclusions and/or homogenization, believed to be specific for EBV in these lesions, was used as an indicator for infection. Cytoplasmic changes were evaluated separately.
RESULTS: With in situ hybridization, 48 cases were positive and 12 were negative. When the two methods were compared, pathologist concurrence ranged from 83% to 92%. False negatives ranged from 6% to 19%, and false positives ranged from 8% to 25%. Cytoplasmic ballooning, homogenization, and perinuclear clearing were evident in all cases of hybridization-confirmed HL; however, these changes were also noted in 75% (9/12) of the cases with negative hybridization results. Most confirmed HL cases exhibited both nuclear homogenization and inclusions, although the former was more consistently seen.
CONCLUSION: Cytoplasmic changes did not agree well with EBV-DNA hybridization results, whereas nuclear changes demonstrated good, but not complete, agreement. In appropriate clinical settings, the finding of nuclear inclusions and/or homogenization may be of diagnostic value. However, because the potential for false positives and negatives is high, H&E cytopathology should not be used as a substitute for in situ hybridization in the definitive diagnosis of oral hairy leukoplakia.     

多媒体技术在医学影像教学实践中的应用

医学影像学是一门实践性很强的形象思维学科,如何合理应用多媒体技术手段开展现代医学影像学教学,本文就多媒体技术与传统板书教学的有机结合进行了有益的探讨。强调做好现代多媒体技术手段教学与传统教学的重要性是医学影像学教学一个值得重视和思考的问题。     

Muscle fiber dysfunction contributes to weakness in inclusion body myositis

Atrophy and fatty infiltration are important causes of muscle weakness in inclusion body myositis (IBM). Muscle weakness can also be caused by reduced specific force; i.e. the amount of force generated per unit of residual muscle tissue. This study investigates in vivo specific force of the quadriceps and ex vivo specific force of single muscle fibers in patients with IBM. We included 8 participants with IBM and 12 healthy controls, who all underwent quantitative muscle testing, quantitative MRI of the quadriceps and paired muscle biopsies of the quadriceps and tibialis anterior. Single muscle fibers were isolated to measure muscle fiber specific force and contractile properties. Both in vivo quadriceps specific force and ex vivo muscle fiber specific force were reduced. Muscle fiber dysfunction was accompanied by reduced active stiffness, which reflects a decrease in the number of attached actin-myosin cross-bridges during activation. Myosin concentration was reduced in IBM fibers. Because reduced specific force contributes to muscle weakness in patients with IBM, therapeutic strategies that augment muscle fiber strength may provide benefit to patients with IBM.