A multiple-frequency, multiple-region pattern electroretinogram investigation of non-linear retinal signals

It has been proposed that the spatial frequency doubled (FD) illusion may originate from Y-like non-linear retinal ganglion cells. If the contrast of multi-frequency stimuli is increased, Y cells show a phase advance in the self-sum frequencies but not in other output frequencies. We looked for these effects with a multi-region pattern electroretinogram (PER.G) displaying the sum of two temporal frequencies in each visual field location. Regional variation was found in the recorded sum and difference frequencies. The results indicate that PERG signals become dominated by responses from Y-like cells when the FD illusion is seen.     

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.     

诊断早期蕈样霉菌病组织学标准的效验--欧洲癌症研究和治疗组织皮肤淋巴瘤研究组的调查报告

为了效验组织病理学标准在诊断早期蕈样霉菌病(ＭＦ)病变中的价值,作者回顾分析了18例患者24次皮肤活检切片,取材时患者处于ＭＦＩａ期。这些病人都具备以下条件:①临床明确诊断ＭＦ或在随后的活检中出现了确切无疑的ＭＦ组织学形态。②通过完整的随访(从起病到发生明显的淋巴瘤,或病人死亡),证明在疾病随后进展中出现了ＭＦ经典“ＡｌｉｂｅｒＢａｚｉｎ”型中典型的斑点、班块、肿瘤期的发展过程。③病人处于Ｉａ期(即局限性斑块、丘疹或湿疹性斑点出现,覆盖面积小于身体表面10%)至少5年。选择13例苔藓样、海绵状及牛皮癣样与ＭＦ相似的病…