Implantation of Octacalcium phosphate to enhance osteogenesis of alveolar ridge defect in rat mandible

Reconstruction of craniofacial bone defects remains one of the most challenging problems encountered by maxillofacial surgeons. This study was designed to investigate the process of bone formation caused by implantation of octacalcium phosphate at mandibular alveolar ridge of rat. In this experimental animal study, 20 male Sprague Dawley rats were used. Synthetic octacalcium phosphate [OCP] was implanted into the bony defect measuring 3 mm in diameter and 2 mm in depth which was surgically created with a bur in the rat mandible. Bone formation at the alveolar ridge was examined histologically between 1 and 4 weeks after implantation. Osteogenesis was initiated in the center of the defect between the OCP particles and multinucleated giant cells appeared on the implanted materials in 1 week. More apposition of new bone was observed on the implanted octacalcium phosphate in week 2. In addition to bone formation locally around the OCP particles, more apposition of new bone was observed near the defect margin in week 3. At week 4, the defect was almost completely filled with bone, which was in close contact with host bone and implanted OCP was surrounded by newly formed bone. In the control group, bone formation was observed only along and near the defect margin. Octacalcium phosphate could be used to enhance atrophic alveolar ridge or for filling a tooth socket after extraction

Identification of D-Gal and Gal/GalNac terminal sugars in basal and squamous cell carcinomas of the skin

Basal and squamous cell carcinomas comprise 90% of all skin malignancies. Cell surface and extracellular glycoconjugates change in neoplastic cells along with morphological changes of cancer cells. In many cases of malignant diseases, these changes of terminal sugars are responsible for invasive and metastatic properties of cancer cells. Recent studies have shown that the reaction of cancer cells change to lectins in course of neoplastic changes. The aim of the present study was to identify D-Gal and Gal/GalNac in basal and squamous cell carcinomas of the skin. In this descriptive study paraffin blocks of a total number of 20 patients [10 SCC and 10 BCC] were selected from pathology file of Khatam Al Anbia hospital in Zahedan. After confirmation of previous diagnosis, from each block 4 sections were prepared and stained by WGA and PNA/Alcian blue [pH=2.5]. After staining, sections were studied blindly by two persons. Histopathological reports were prepared according to staining intensity and the location of reaction to lectins. Brown precipitate in cell and extracellular matrix were recognized as positive reaction. The presence of Gal/GalNac terminal sugar was confirmed by PNA lectin in squamous cell carcinoma of the skin. The nuclei of cancer cells did not react to lectin. Cancer cells in Basal cell carcinoma did not react to WGA lectin for D-Gal terminal sugar either. The presence of D-Gal was confirmed in basal cell carcinoma. Neoplastic cells in squamous cell carcinoma did not react to WGA. It seems that in neoplastic changes, terminal sugars of glycoconjugate change with different patterns in skin malignancies, so that PNA lectin is a good marker for SCC and WGA for BCC

[ effects of hyaluronan on fertilization capability of mouse sperm before cryopreservation and after thawing]

Freezing and thawing induce a number of insults to the sperm cells, such as low motility and low fertilization capability. For evaluation of hyaluronan [HA] supplementation on sperm characteristics, we investigated the effect of hyaluronan [HA] on mouse sperm before freezing and after thawing. For this purpose we removed cauda epididimes from 24 male mice with aseptic method and freezed the semen in 1.8ml cryotubes with%18 raffinose and%3 skim milk cryoprotectant solution.We had 4 groups: group 1[fresh control] group 2 [freeze control] group 3[supplemented 750 micro g/ml HA to sperm before freezing] and group 4[supplemented 750 micro g/ml HA to sperm after thawing]. Fertility rate evaluated after routine IVF by counting two-cell stage embryos. HA supplementation [750 micro g /ml] after thawing improved fertilization capability parameters but supplementation before freezing had no effect on mentioned characteristic. Acording to data of present study the hyaluronan supplemen- tation [750 micro g /ml] after thawing has the greatest effect on the fertility rate of sperms

[Histochemical study of structural changes of carotid wall arteries in male diabetic rats]

Background: diabetes mellitus is a prevalent disease, which is caused by deficiency in insulin secretion or factors that impair its function. Diabetic hyperglycemia and hyperlipidemia are important risk factors in cardiovascular diseases. The arteriosclerosis and its accompanying structural changes are in part due to endothelial cell injury and abnormal glycosylation of cell surface and extra cellular matrix glycoconjugate. These are the first structural changes of formation of atheromatous plaque. The aim of the present study was to identify the structural and extra cellular matrix changes of terminal sugars by histochemical methods in aorta and common carotid arteries in male diabetic rats

Methods and Materials: a total number of 63 male Sprague Dawley rats with 250 +/- 50 gr weights were chosen and randomly divided into experimental [n=36] and control [n= 27] groups. Diabetes was induced by IP injection of 60 mglkg of streptozotocin in experimental group. Experimental and control groups further divided into 2 week, 2 months and 4 months subgroups. Animals were preserved in standard condition. After the mentioned time, samples were taken from carotid and aorta, _fixed in Bains and processed routinely. Paraffin blocks were cut with 5-6 micrometer in thickness and stained by H-E, PAS and PNA/Alcian blue pH=2.5, thereafter sections graded according to staining intensity and data were analyzed by NPAR test of Mann Whitney

Results: results of this study showed significant difference only for PAS positive media components between 2 and 4 months diabetic groups [P<0.007]. There were also statistically significant difference between elastic lamina of 2 and 4 month of diabetic group [P<0.03]. PNA showed the presence of Gal/Ga/Nae in sub endothelial and adventitial components of arteries. Although there was a slight difference of ECM staining between diabetic groups for the Gal/Ga/Nae and intense reactivity of 4-month diabetic group in comparison to 2-month and 2-week diabetic groups, there were no significant difference between them for PAS and lectin staining

Conclusions: it seems that in diabetes, the rate of glycosylation of cell surface and ECM components changed slowly. Future studies will probably show the exact role of these components in pathophysiology of diabetes