Fate of implanted autologus cartilage grafts in rabbits: an experimental histological study

Cartilage grafts are commonly used for a variety of purposes in plastic and reconstructive surgery. Despite their extensive use, the fate of cartilage as a graft is frequently disputed; many factors could affect such fate, among which the role of perichondrium and that of surgical trauma. The present study was conducted to evaluate the fate of implanted autologous cartilage grafts in rabbits and to study the effect of the perichondrium and that of the scoring on cartilage survival and resorption. 10 adult male New Zealand white rabbits were operated upon. Four equal sized auricular cartilage grafts were harvested from each rabbit, as well as a pre-implanted control cartilage graft. After accurate measuring and weighing of the grafts, they were implanted in a dorsal subcutaneous pocket in the same rabbit. The role of perichondrium was examined by implanting three types of cartilage grafts; the first with no perichondrium on either side, the second with perichondrium removed from one side, while in the third, the perichondrium was left intact on both sides. The effect of mechanical surgical trauma was examined by implanting a scored cartilage graft. Twelve weeks after their implantation. all cartilage grafts were retrieved, examined macroscopically. measured accurately, weighted and subjected to histological examination. Pre and post-implanted cartilage grafts were stained by: Haematoxylin and Eosin, Orcein and Toluidine blue stains. They were also examined by the scanning electron microscope. The results were compared to the preoperative values. Gross examination revealed ho obvious deviation from the preimplanted auricular cartilage graft regarding color, texture and consistency, although cartilage grafts without perichondrium seemed to be thinner and more pliable. These findings correlate well with the histological [light microscopic and scanning electron microscopic findings in which unscored cartilage grafts retaining their perichondrium were the most viable with active chondrocytes, healthy looking matrix and increased proliferative activity of chondroblasts adjacent to the perichondrium. These grafts have shown a modest increase in their post-implantation weight which could be either due to the observed neochondrogenesis or to a change in the ability of the cartilage grafts to retain water. Cartilage grafts in which perichondrium was removed from both sides has shown an insignificant decrease in their post-implantation weight, yet histologicaly they were viable but no chondrocytic activity was observed They showed definite decrease in the metachromatic reaction which was more evident at the periphery of either side of the cartilage plates which could be due to a change in the chemical composition of the bare mucopolysaccharides. Peripheral decrease in metachromasia along with the lack of chondrocyte activity could represent an early but slow resorption process of the bare cartilage. In scored cartilage grafts, although the perichondrium was preserved on both sides of the grafts, no significant change in the weight was observed; also on histological examination, they did not show any evident chondrocytic proliferation. This could reflect also a slow resorption process in the scored cartilage grafts. Cartilage grafts implanted subcutaneously do survive regardless the presence of perichondrium. Perichondrium enhances cartilage graft survival and seems to act as a protecting shell preventing direct exposure of the graft to the notorious effects of local mediators of wound healing environment that might lead to cartilage resorption. Although scored cartilage grafts implanted subcutaneously do survive and maintain its curvature, yet scoring increases the surface area of the bare cartilage exposed to the local mediators and thus might put them at risk of slow long term resorption

Effects of oxymetazoline on the nasal mucosa of rats: an ultrastructural study

It is recommended that decongestant nasal drops should not be used for more than 10 days. However, overuse or misuse of these medications occurs commonly, which may lead to injurious effects on the nasal mucosa. Ten male rats receiving either oxymetazoline or saline nasal drops were killed after 8 weeks. Respiratory and olfactory nasal mucosae were dissected and processed for light and electron microscopic study. Nasal respiratory mucosa showed multi-focal areas of proliferation, metaplasia and degeneration accompanied by ciliary loss. The olfactory mucosa revealed disorganization, degenerative changes with atypical nuclei. Prolonged administration of oxymetazoline topical nasal drops can result in structural and functional alterations in the rat nasal respiratory and olfactory mucosae, presumably due to the combination of the chronic hypoxic effect of the reduced blood flow and the impairment of the mucociliary clearance

Histochemical study of the respiratory nasal mucosa in addicts sniffing heroin

The study was carried out on 10 males aged from 30-50 years, addict for hercin for more than five years as well as 10 control volunteers of matched sex and age. A punch biopsy was taken from the nasal mucosa of the inferior turbinate of both the addicts and controls. Each biopsy was divided into two parts one part was fixed in formaline and subjected to the PAS-Alcian blue stain and the other part was immediately frozen, cryostate cut and stained to demonstrate the activity of succinic dehydrogenase, alpha esterase, alkaline and acid phosphatases enzymes. PAS-Alcian blue stain showed absence of the alcianophilic reaction from the surface epithelium and the ground substance and its decrease in the tunical glands. Histochemical enzymatic study revealed marked increase in the activity of all the studied enzymes

respiratory nasal mucosa in addicts sniffing heroin: a histological and ultrastructural study

This study was carried out on ten male addicts admitted in the Psychiatry Department of the Hadara University Hospital aged from 30- 50 years and they were sniffing heroin for more than five years, control nasal biopsies were taken from ten volunteers with matched age, and sex. The nasal biopsies were subjected to histological study using H and E stain and ultrastructural study using the transmission electron microscope. Statistical analysis of the morphological grading of the nasal mucosa was done using the t- test and the coefficient correlation test. Histologically, most of the cases of heroin sniffing addiction showed squamous metaplasia with budding of the epithelium into the lamina propria. Variable degrees of degeneration of the epithelial cells and decrease in the total number of the tunical glands with predominance of the mucous acini. Statistically, a highly significant difference was found between the addicts and the control group. Ultrastructurally, the metaplastic epithelial cells were greatly separated from each other. The mucous glands were hyperactive producing different ultrastructural types of mucous granules. The blood vessels showed hypertrophy of their endothelial cells and the lamina propria showed cellular infiltration by fibroblasts, macrophages and foreign body giant cells