Post Graduation Program in Health Sciences, Universidade Católica de Pelotas, Pelotas, RS, Brazil.
Post Graduation Program in Health Sciences, Universidade Católica de Pelotas, Pelotas, RS, Brazil; Department of Dermatology, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
An Bras Dermatol. 2022 Nov-Dec;97(6):742-746. doi: 10.1016/j.abd.2021.10.011. Epub 2022 Sep 10.
Little is known about the ultrastructure of pili annulati.
To examine with transmission electron microscopy affected hairs of a family, whose diagnosis had been confirmed in five individuals with scanning electron microscopy, which showed surface undulations with "curtain-like" folding of the hair cuticula and to compare the findings with normal control.
Hairs of two affected patients and one control were embedded in resin and cut lengthwise to produce ultra-thin sections.
The normal hair showed a parallel arrangement of dark lines associated with less electron-dense wide bands. Small cavities could be observed, mostly in the dark lines, affected hairs had a large number of cavities, associated or not with the insertion of melanosomes and loss of parallelism of the dark lines. Higher magnification showed a significant loss of this parallelism, resembling "wood grooves". Widened dark lines were observed in some areas.
Only a few hairs were examined.
The present results suggest that the microcanaliculi of the hair surface, easily found with scanning electron microscopy, may be secondary not only to the cavities seen in the sections but also to the disorder of proteins that form this region, demonstrated by the changes of the cortex dark lines.
关于环形发微结构的了解甚少。
用透射电子显微镜检查一个家系的受影响毛发，其诊断已通过扫描电子显微镜在五名个体中得到证实，扫描电子显微镜显示毛发角质层的表面波动呈“幕帘样”折叠，将这些发现与正常对照进行比较。
将两名受影响患者和一名对照者的毛发嵌入树脂中并沿长度方向切割，以产生超薄切片。
正常毛发显示出与较暗线相关的平行线排列，这些线与较暗的宽带相比电子密度较低。可以观察到小的腔，主要在暗线中，受影响的毛发有大量的腔，与黑素体的插入或平行的暗线的缺失有关。高倍放大显示出这种平行性的显著丧失，类似于“木槽”。在一些区域观察到暗线变宽。
仅检查了少数几根毛发。
目前的结果表明，扫描电子显微镜容易发现的毛发表面微管可能不仅与切片中看到的腔有关，而且与形成该区域的蛋白质紊乱有关，这是通过皮质暗线的变化表现出来的。
