Kumagai H, Masuda T, Maisawa S, Chida S
Department of Paediatrics, School of Medicine, Iwate Medical University, Morioka, Japan.
J Pediatr Gastroenterol Nutr. 2001 Apr;32(4):428-33. doi: 10.1097/00005176-200104000-00007.
Histologic studies of rectosigmoidal mucosal biopsies of infants with isolated blood-streaked stool have shown many eosinophils and revealed aggregates of small dark granules (nuclear dust). However, no description of the nuclear dust has been made for this condition and the nature of the nuclear dust has not been thoroughly investigated. We determined the characteristics of these particles in biopsies from infants with streaked rectal bleeding.
Nineteen infants who were younger than 6 months old and had isolated rectal bleeding were studied, as were six age-matched control infants. Rectosigmoidal mucosal biopsies were immunohistochemically assessed using anticarcinoembryonic antigen and macrophage-associated antibodies and examined for apoptotic cells by modified in situ TdT-mediated dUTP-biotin nick-end labelling. The number of apoptotic epithelial cells was compared between rectal bleeding and control groups.
Immunohistochemistry showed that at least some of the nuclear dust consisted of apoptotic epithelial cells. Infants with rectal bleeding also showed nodular lymphoid hyperplasia (n = 16), abundant eosinophils (>20/high power field, n = 14) in the mucosa, and a significantly high number of apoptotic epithelial cells relative to the control group. Rectal bleeding disappeared at 6-month follow-up in 14 of 18 infants (one was lost to follow-up) who were fed a different milk formula or breast-fed (their mothers were restricted from having cow's milk and eggs).
The high number of apoptotic epithelial cells in rectosigmoidal mucosal biopsies of infants with streaked rectal bleeding is probably caused by accelerated epithelial cell turnover and apoptosis.
对有孤立性便血的婴儿进行直肠乙状结肠黏膜活检的组织学研究显示，有许多嗜酸性粒细胞，并发现有小的深色颗粒（核尘）聚集。然而，对于这种情况尚未对核尘进行描述，其性质也未得到充分研究。我们确定了有直肠出血条纹的婴儿活检组织中这些颗粒的特征。
研究了19名6个月以下有孤立性直肠出血的婴儿，以及6名年龄匹配的对照婴儿。使用抗癌胚抗原和巨噬细胞相关抗体对直肠乙状结肠黏膜活检组织进行免疫组织化学评估，并通过改良的原位TdT介导的dUTP生物素缺口末端标记法检测凋亡细胞。比较直肠出血组和对照组凋亡上皮细胞的数量。
免疫组织化学显示，至少部分核尘由凋亡上皮细胞组成。有直肠出血的婴儿还表现为结节性淋巴样增生（n = 16），黏膜中有大量嗜酸性粒细胞（>20/高倍视野，n = 14），且相对于对照组，凋亡上皮细胞数量显著增多。在18名婴儿（1名失访）中，14名喂食不同配方奶或母乳喂养（其母亲被限制摄入牛奶和鸡蛋）的婴儿在6个月随访时直肠出血消失。
有直肠出血条纹的婴儿直肠乙状结肠黏膜活检中凋亡上皮细胞数量增多可能是由上皮细胞更新和凋亡加速所致。
