Immunohitochemical localization of matrix metalloproteinase-12 [macrophage elastase] in rabbit mandibular condyle following experimental induction of anterior disc displacement

The purpose of the present study was to investigate the immunohistochemical distribution of matrix metalloproteinase-12 [MMP-12] in the rabbit mandibular condyle following experimental induction of anterior disc displacement. The right temporomandibular Joint [TMJ] of nine rabbits was exposed surgically and all discal attachments were severed except for the posterior attachment. The disc was then repositioned anteriorly. The left TMJ served as a control. Mandibular condyles were excised at 2, 4 and 7 weeks following surgery. These specimens were prepared and stained by Haematoxyline and eosin [H and E] for routine histological examination. For immunohistochemical staining with MMP-12, five micron thick sections were cut and mounted on positively charged slides. After two weeks the current study revealed the presence of numerous intense immunoreactivities at the bone cartilage interface. Some of the chondrocytes showed intense granuliform reactivity for MMP-12. The subchondral bone showed also intense immunoreactivities surrounding both Haversian and Volkmann canals as well as along the entire borders of large resorbed bone marrow spaces. These immunohistochemical results concomitant with the breakdown of the articular cartilage and degradation of the extracellular matrix as well as splitting phenomena at the bone cartilage interface observed histologically during this period. After four weeks, the articular cartilage was lost and the mandibular condyle showed formation of coarse fibered woven bone. The immunohistochemical staining for MMP-12 was relatively weak at the surface of the woven bone and appeared to be moderate in the deep layer. After seven weeks, the mandibular condyle showed irregular remodeling of bone with negligiable immunoreactivity in the remodeled bone trabeculae. On the other hand, in the control group the MMP-12 was relatively weak at the surface of the woven bone and appeared to be moderate in the deep layer. After seven weeks, the mandibular condyle showed irregular remodeling of bone with negligiable immunoreactivity in the remodeled bone trabeculae. On the other hand, in the control group the MMP-12 immunoreactivites were noticed relatively weak mainly around the Haversian canals. In conclusion, the increased expression of MMP-12 in rabbit mandibular condyle was detected obviously after two weeks rather than after four and seven weeks postoperatively. These results provide evidence for a potential role of MMP-12 in the pathogenesis of osteoarthritis and imply that the inhibition of MMP-12 may be potentially therapeutic for the treatment of degenerative joint diseases

Histochemical study on the possible effect of acetyl salicylic acid [aspirin] on the percentage of survival cells in salivary glands of irradiated rat

In this report the protective effect of acetyl salicylic acid [ASA] against radiation injury to salivary glands in rats was assessed. Thirty male rats were used in this study and classified as two groups. The control group didn't receive ASA throughout the experiment. While the experimental group received ASA in drinking water [2.5g/ 1L] one week before the exposure to irradiation. Both groups were irradiated by single dose gamma radiation [6.5Gy]. The administration of ASA to the experimental group was continued up to five weeks after radiation. The parotid and submandibular salivary glands were excised and prepared for histological and histochemical examination. The prepared sections were either stained with Haematoxylin and Eosin for routine histological examination, while others were stained by silver staining for detection of Nucleolar Organizer Region [AgNORs] at one and five weeks only. Our data revealed remarkable reduction in the damaged effect of irradiation in the experimental group of both glands along all period of the experiment following irradiation. Furthermore, the regeneration rate of destructive parenchymal elements was found to be faster in the experimental group than in the control group. By employing silver staining to detect the nucleolar organizer region, our results reported that the survival cells were stained brown. Comparing the whole results, it was obvious that the percentage of survival cells were higher in the parotid gland than in the submandibular gland. Furthermore the experimental group of both glands showed significant increase in the survival cells as well as in their distribution compared to that observed in the control group both after one and five weeks following irradiation. Finally the protective effect of ASA reflected on the higher percentage of survival cells in the experimental group in both glands. This could be explained on the assumption that ASA produced a concentration dependent reduction in radiation induced DNA damage in the cells

Assessment of erythropoiesis in renal anemia using soluble transferrin receptors

To evaluate the clinical usefulness of soluble transferrin receptors [sTFR], 42 patients were enrolled in this study representing four groups. Group I included 10 end stage renal disease [ESRD] patients on HD, EPO and i.v. iron twice-thrice/week [their age ranged from 6 to 12 years with a mean of 7 years]. Group II included 18 ESRD patients on conservative management without regular HD nor erythropoietin, they received maintenance oral iron deficiency anemia with normal kidney functions [their mean age was 6.5 years], they were on iron therapy. Group IV included 13 healthy children with normal Hb level and normal kidney functions [they were age and sex matched as a control group and their mean age was 7 years]. Three parameters for the assessment of erythropoiesis were used in all groups [Hb, sTER and serum ferritin]. Kidney function tests were also determined

value of insulin-like growth factor binding protein-3 in growth assessment of juvenile rheumatoid arthritis patients

This study was carried out on 40 children having juvenile rheumatoid arthritis [JRA], their mean age was 8.5 +/- 2.8 with a range of 3-18 years. Two hundred and ninety healthy children, age and sex matched with the patients, were included as controls. History, clinical examination and full anthropometry were performed. The basal levels of insulin like growth factor 1 [IGF1] and IGF binding protein 3 [IGFBP3] were assessed. Growth hormone assessment was performed in patients with compromised growth and in those having low IGF1 values. Mean height standard deviation score [SDS] of the patients was significantly lower compared with the controls. Mean IGF1 and IGFBP3 values as well as their Z scores were significantly lower in patients than in controls whether pre or post pubertal. IGF1 Z scores were positively correlated to IGFBP3 Z score in a statistically significant manner. IGF1 Z score was also positively correlated to height SDS and negatively correlated to steroid therapy. The group of patients who received glucocorticoids was shorter, showed less IGF1 Z score and IGFBP3 Z score than the group who did not receive steroid therapy. GH stimulation tests in patients with compromised growth showed normal values [mean +/- SD was 21.0 +/- 5.7 ng/ml, with a range of 10-30]. IGF1 and IGFBP3 Z scores were less in the group with compromised growth than in that with fair growth [-2.40 + 1.58 and -2.34 + 1.85 versus -1.41 + 0.86 and -1.11 + 1.49, respectively] and the difference was statistically significant