Mohammad Mehdizadeh

Evaluation of the ability of natural and synthetic scaffolds in providing an appropriate environment for growth and chondrogenic differentiation of adipose-derived mesenchymal stem cel

Background: Although progenitor cells have been observed in articular cartilage, this part has a limited ability to repair due to a lack of blood supply. Formerly, tissue engineering was mainly based on collecting chondrocytes from the joint surface, culturing them on resorbable scaffolds such as poly D, L-lactic glycolic acid (PLGA) and then autologous transplantation. In recent times, due to difficulties in collecting chondrocytes, most of the researchers are focused on stem cells for producing these cells. Among the important factors in this approach, is using appropriate scaffolds with good mechanical and biological properties to provide optimal environment for growth and development of stem cells. In this study, we evaluated the potential of fibrin glue, PLGA and alginate scaffolds in providing a suitable environment for growth and chondrogenic differentiation of mesenchymal stem cells (MSCs) in the presence of transforming growth factor-β3. Materials and Methods: Fibrin glue, PLGA and alginate scaffolds were prepared and MSCs were isolated from human adipose tissue. Cells were cultured separately on the scaffolds and 2 weeks after differentiation, chondrogenic genes, cell proliferation ability and morphology in each scaffold were evaluated using real time-polymerase chain reaction, MTT chondrogenic assay and histological examination, respectively. Results: Proliferation of differentiated adipose tissue derived mesenchymal stem cells (AD-MSCs) to chondrogenic cells in Fibrin glue were significantly higher than in other scaffolds. Also, Fibrin glue caused the highest expression of chondrogenic genes compared to the other scaffolds. Histological examination revealed that the pores of the Fibrin glue scaffolds were filled with cells uniformly distributed. Conclusion: According to the results of the study, it can be concluded that natural scaffolds such as fibrin can be used as an appropriate environment for cartilage differentiation.

Evaluation of oral mucosal epithelium in diabetic male patients by exfoliative cytology method

BackgroundThe goal of present study is to examine comparatively the epithelium of oral mucosa in persons with diabetes types I and II and the healthy persons by cytomorphometric method.MethodsCytology smear was prepared from oral mucosa epithelium in 24 persons with diabetes and 30 healthy persons were stained by papanicolao method. Its before, from patients were requested acquiring written. The quantitative cytomorphometric characteristics were measured in each group by motic plus 2 software. Also, the qualitative evaluation of cytology slides are performed in three groups.ResultsThere were decrease in the nuclear and cytoplasmic size, (P < 0.001) and increase in the ratio of nuclear to cytoplasm size in buccal mucosal areas (P = 0.001) and tongue (P = 0.011) of diabetic persons compared to the healthy persons. There was no significantly statistical difference in diabetic persons types I and II in buccal mucosal area (P = 0.15) and tongue (P = 0.86) in quantitative characteristics of cytomoerphometry. In nuclear and cytoplasm size, there was a significant statistical difference in persons with diabetes type I and persons of control I and persons with diabetes type II and persons of control II in buccal mucosa and the tongue (P < 0.001). Bilobed or multi-lobed nuleous, karyorrhexis and vacuolization of cytoplasm were more in diabetic persons compared to the healthy ones (P < 0.001).ConclusionDiabetes are effective in creating some quantitative and qualitative cytometric alterations in the oral mucosa but the type of diabetes doesn’t seem to be effective on these changes.

Radiographic Evaluation of Impacted Third Molars and Their Complications in a Group of Iranian Population

Background and aim : An impacted tooth is a tooth that did not grow on its expected time because of an incorrect position or lack of space. The impacted third molar is the most common impacted tooth. In the present study, the presence of the impacted third molar teeth and their complications in the panoramic radiography of patients were evaluated. Methods and materials : The frequency of impacted third molars, in two jaws and two genders, their position (impaction depth and angulations), their influence on adjacent teeth and their relations to inferior alveolar canal were evaluated in 2000 panoramic radiography of patients who were over 20 years old. Results : 333(16.65%) patients [161(48.3%) men and 172(51.7%) women] with mean age of 30.32 ± 7.22 years (between 20 - 68 years old) had impacted teeth. 313 cases only had impacted third molars, 16 cases had other impacted teeth and 4 patients had both impacted third molar and other impacted teeth. Prevalence of impacted wisdom teeth is in mandible more than maxilla and in women more than men. The mesioangular angulation in mandible and upright angulation in the maxilla were the most common angular position. Type B in the mandible and type C in the maxilla were the most common types of impactions depth. Most of the mandibular and maxillary impacted third molars showed complete root development. Higher frequency of distal caries or defects of the adjacent second molars was found in the mandible. Conclusion: Frequency of impacted third molars in mandible was more than maxilla. Also impacted third molars were found in women more than men. With regard to mandibular third molars, mesioangular and type IB were the common pattern.The relationship between the position of the tooth and distal caries of second molar will be an interesting finding and has clinical importance.