[Case report of a foreign body in the nasal cavity: experimental research on limited damage].

We report here a case of serious nasal cavity tissue damage caused by a foreign substance, specifically, a button-shaped battery. The patient was a three-year-old boy who inserted a button-shaped battery into his left nasal cavity. On examination, we found necrosis of the nasal mucosa, cartilage and bone. In addition, the nasal cavity structure was severely damaged. In a follow-up experiment, we inserted a similar button-shaped battery, pre-soaked in a salt solution, into a rabbit's nasal cavity and measured daily changes in PH and discharge over time. In addition, we assessed how much nasal cavity tissue was damaged in a pathological specimen. We found that the chief factor mediating tissue damage, among those we tried, was strong base production with low voltage discharge. Under these conditions the nasal cavity is damaged in a short time.

Electron microscopic study of vascular regeneration in rat tracheal mucosa following physical curettage.

Transmission and scanning electron microscopic studies were made of regeneration of the vascular network of rat tracheal mucosa on 30 min to 8 hr after the mechanical curettage. The vascular network casts were made by infusion of Mercox resin through the aortic arch for scanning electron microscopy. At 30 min after curettage, vascular thromboses were observed, and terminal blind branches were formed in the injured blood vessels areas through SEM observation. Diapedesis of leukocytes appeared at 30 min after curettage from intact venules at the wound margins. Recovery from the loss of endothelial cells began at 30 min after curettage. At 3 hr after curettage, vascular indentation (protrusion) and vascular process (bud-like process) were developed from intact venules at the wound margins. It is concluded that the formation of thrombus and terminal blind branch vessels constitute the initial reparative reactions of the injured vascular network and that new vessels then begin to form by outgrowth of protrusions and bud-like processes from intact venules at the wound margins.

[An ultrastructural study on the regeneration of blood vessels of the curetted tracheal mucosa in rat].

After the respiratory tract is damaged by trauma or infection, it is repaired rapidly. The purpose of this study is to observe morphologically the regenerative process of tracheal mucosae, especially the regeneration of blood vessels in the mechanically injured tracheal mucosa of rats. The total mucosal layer of trachea was removed by curetting in 95 adult rats. Then, at several interval from one hour to ten weeks after treatment, 5 rats were killed, and their curreted area of the trachea were removed as specimen for transmission electron microscopical and scanning electron microscopical observation. For scanning electron microscopy, vascular network casts were made by the infusion of Mercox resin through the aortic arch. One hour after curetting, the injured blood vessels formed terminal blind branches. From three hours to one week after curetting, many vascular bud-like-processes appeared in venules at the floor and margin of the curetted wound. Twelve hours after curetting, new vascular network were observed in the curetted area. One week after curetting, the vascular network was consisted of capillaries, veins, and arteries. The vascular networks were almost completely rearranged at six weeks after curetting. However the irregular arrangement were still observed partially after ten weeks of curetting. The formation of terminal blind branches in vessels were noted as the initial healing process of injured vascular networks. Then many "bud-like-processes" appeared. Six weeks after curetting, the vascular networks were almost completely rearranged.