الفهرس 
Review of literatureOnly 14 pages are availabe for public view
 |  | from | 32 |  |  |
| | | from | 32 | | |
Abstract
It is to test for the effect of the use of bone marrow derived mesenchymal stem cells in stopping if not reversing the aging effects in tongue epithelium and lingual salivary glands of aged rats.Materials and Methods:Forty Five male albino rats were used in this investigation and divided as follows:Group Ӏ animals consisted of 15 three months old rats that served as controls.Group ӀӀ animals consisted of 15 twelve months old rats.Group ӀӀӀ animals consisted of 15 twelve months old that were subjected to intravenous infusion by bone marrow mesenchymal stem cells to study the effect of injection of bone marrow stem cells on the lingual mucosa and salivary glands.An additional fifteen 6 weeks old male albino rats were used for isolation and culture of bone marrow stem cells.Four weeks after the injections, the animals tongues were dissected out, cut longitudinally, fixed in 10% neutral buffered formalin, processed and embedded in paraffin. Sections were cut and stained with:a) Hematoxylin and eosin for histological examinations.b) Masson’s trichrome for collagen.c) Proliferating cell nuclear antigen (PCNA) to detect the rate of cell proliferation.142 Representative tongue specimens from the different groups were fixed, dried, sputtered and examined with scanning electron microscope.Results:Ӏ. Histological Results:-A. Hematoxylin and Eosin stain results1. Group Ӏ animals (Young control group):-The histological examination of tongue taken from young control group showed well-developed conical shaped filiform and the fungiform papillae which appeared rounded with flattened apex and well developed taste pore. The circumvallate papilla was surrounded with a circular furrow.At the bottom of the furrow opened the ducts of pure serous salivary glands formed of serous triangular acini. Pure mucous salivary glands were also seen formed of large, oval or tubular acini lined with high cuboidal mucous secreting cells.The ventral stratified squamous surface epithelium had broad epithelial ridges towards the underlying lamina propria. The lamina propria appeared with the normal loosely arranged collagen fibers.2. Group ӀӀ animals (Old control group):-
The histological examination of tongue taken from 12 months old control group showed multiple changes:The filiform papillae were markedly atrophic and there was a decrease in their number. The fungiform and circumvallate papillae 143showed signs of atrophy and shrinkage. The circumvallate papillae were either degenerated or completely lost.The keratinized stratified squamous epithelium of the dorsal surface was very thin and atrophic. The underlying lamina propria showed degeneration and dissociation of collagen fibers with marked dilatation of blood vessels.The lingual glands also suffered from marked degenerative changes. The ducts of both serous and mucous glands were atrophic with marked flattening of their epithelial lining.The ventral surface epithelium was so thin, atrophic with intracellular cytoplasmic vacuolization and a decrease in the epithelial ridges.3. Group ӀӀӀ animals Old rats subjected to intravenous infusion by bone marrow mesenchymal stem cells and showed improvement in their histology.The dorsal surface of the tongue showed an apparent increase in the number and the length of filiform papillae. The fungiform and circumvallate papillae appeared more or less normal with minor signs of shrinkage or degeneration with an improvement in the taste buds.The surface epithelium of dorsal surface showed an increase in its thickness and the lamina propria partially regained the density and arrangement of its collagen fibers. The mucous membrane of the ventral surface of the tongue regained its thickness with normal pattern of epithelial ridges.The serous and mucous acini of the lingual glands showed partial improvement of the normal histological architecture.144 B. Masson’s Trichrome Staining1. Group I animals (Young control group):-
The histological examination of the tongue taken from rats of young control group, and stained with Masson’s trichrome stain revealed a moderately to strongly positive staining of the collagen fibers of the lamina propria of the dorsal and ventral surfaces of the tongue as well as the connective tissue septa dividing the salivary glands into lobes and lobules.2. Group ӀӀ animals (Old control group):-
The tongue obtained from old control rats revealed that the collagen fibers of the lamina propria of the dorsal and ventral surfaces as well as the connective tissue septa of the serous and mucous salivary glands showed weakly positive staining with Masson’s trichrome stain. However same fibrotic areas showed strongly positive reaction.2. Group ӀӀӀ animals :-
The examined tongue of rats that received mesenchymal stem cells injections showed improvement in the density and distribution of the collagen fibers of the lamina propria of the dorsal and ventral surfaces of the tongue as well as the connective tissue septa of the lingual glands which became more organized and presented moderately positive stain with Masson’s trichrome stain.II. Immunohistochemical results:-
Proliferating Cell Nuclear Antigen (PCNA)1. Group Ӏ animals (Young control group):-
145 The histological sections of the young controls revealed moderately positive PCNA staining reaction mainly at the basal and parabasal cells of the epithelium indicating normal cell proliferation and division of the dorsal and ventral surfaces of the tongue.2. Group ӀӀ animals (Old control group):- The sections showed low expression of PCNA in the basal layer of the epithelium of the dorsal and ventral surfaces of the tongue ranging from negative to weekly positive staining reaction which indicates a decrease in cell proliferation of basal and parabasal cell layers indicating tissue degeneration.3. Group ӀӀӀ animals:-
The sections of the tongues of old rats that received intravenous injection of bone marrow mesenchymal stem cells, showed moderately to strongly positive PCNA expression in the basal and ventral surfaces of the tongue.Scanning Electron Microscope (SEM)
Examining the dorsal surface of the representative tongue specimens from the different groups with scanning electron microscope after being fixed, dried and sputtered with gold showed the following:-
1. Group Ӏ animals (Young control group):-
The dorsal surface of the tongue was mainly covered with long and conical filiform papillae that were highly organized in their arrangement. The fungiform papillae present among the filiform papillae were large, rounded or elliptical in shape and randomly distributed with a normal taste pore.146 The circumvallate papillae were situated symmetrically anterior to the terminal sulcus. The body of the papilla was surrounded by a continuous trench and mucosal folds. They were large and well developed.2. Group ӀӀ animals (Old control group):-There were changes in morphology and number of the different papillae. The filiform papillae became thinner having more of a slender shape than a conical shape. The fungiform papillae of aged rats examined by scanning electron microscopy (SEM) were smaller in size, shrunken, and degenerated. The taste pore sometimes appeared obliterated.The circumvallate papillae were atrophic with irregular outline. Some showed deepening of the furrow surrounding them and were completely absent in others.3. Group ӀӀӀ animals :-The tongues of the rats that received intravenous injection of stem cells showed improvement. The filiform papillae were numerous in number, long and conical in shape. The Fungiform papillae were large, rounded or elliptical in shape. Taste pores were obvious on the surface of the fungiform papillae along with some scaling cells at higher magnification.In the posterior part of the tongue there was a pair of circumvallate papillae that looked normal. Each papilla had a circular form with a furrow around it.