Biomedical subjects

Abdullah Kalayci

Publications and source records attributed to Abdullah Kalayci.

3 recordsLinked to original sources

PubMed2005

Superoxide dismutase and glutathione peroxidase enzyme activities in larynx carcinoma.

CONCLUSIONS: It can be concluded that these changes are related to damage at the DNA level or to the inhibitory effects of tumor promoters. Increases in GSH-Px activities may be related to the independence of this enzyme from the suppressive effects of tumor promoters. This study and others in the literature show that it is not possible to generalize the activities of SOD and GSH-Px in cancer. OBJECTIVE: There has been growing interest in the role of free radicals as a cause of cancer. It has been suggested that an increase in activated forms of oxygen in cells due to overproduction and/or the inability to destroy them may lead to severe damage of cell structures. As a result of these changes, some chromosomal aberrations and carcinogenesis may develop. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) are two important antioxidant enzymes involved in enzymatic antioxidant defense mechanisms. To our knowledge there have been no previous studies in the literature investigating the activities of SOD and GSH-Px in laryngeal cancer. MATERIAL AND METHODS: The study subjects comprised 10 male patients (age range 43-76 years) with laryngeal carcinoma and 10 healthy controls (4 males, 6 females; age range 40-69 years) with intraoral hyperplastic fibrous tissue. Homogenate SOD and GSH-Px activities were measured using commercially available kits. RESULTS: GSH-Px levels were significantly increased in the cancerous tissues compared with cancer-free adjacent tissues and fibrous hyperplasia tissues (p < 0.05), whereas there was no significant difference between SOD activities (p > 0.05). There was also no significant difference between GSH-Px activity in cancer-free adjacent tissues and fibrous hyperplasia tissues (p > 0.05).

Adult↗

PubMed2004

Intraosseous screw-supported upper molar distalization.

The aims of the present study were to investigate (1) the efficiency of intraosseous screws for anchorage in maxillary molar distalization and (2) the sagittal and vertical skeletal, dental, and soft tissue changes after maxillary molar distalization using intraosseous screw-supported anchorage. Twenty-five subjects (18 girls and seven boys; 11.3 to 16.5 years of age) with skeletal Class I, dental Class II malocclusion participated in the study. An anchorage unit was prepared for molar distalization by placing an intraosseous screw behind the incisive canal at a safe distance from the midpalatal suture following the palatal anatomy. The screws were placed and immediately loaded to distalize upper first molars or the second molars when they were present. The average distalization time to achieve an overcorrected Class I molar relationship was 4.6 months. The skeletal and dental changes were measured on cephalograms and dental casts obtained before and after the distalization. In the cephalograms, the upper first molars were tipped 8.8 degrees and moved 3.9 mm distally on average. On the dental casts, the mean distalization was five mm. The upper molars were rotated distopalatally. Mild protrusion (mean 0.5 mm) of the upper central incisors was also recorded. However, there was no change in overjet, overbite, or mandibular plane angle measurements. In conclusion, immediately loaded intraosseous screw-supported anchorage unit was successful in achieving sufficient molar distalization without major anchorage loss.

Adolescent↗

PubMed2003

Desmoplastic ameloblastoma in the mandible.

The desmoplastic variant of ameloblastoma (DA) is characterized by unique histological and radiographic features. It is histologically characterized by an abundance of densely collagenous stroma with small nests and strands of likely compressed odontogenic epithelium. Although radiographic examination of ameloblastomas usually reveals unilocular or multilocular radiolucency, DA may appear as a mixed radiopaque-radiolucent lesion. In this case report, a 68-year-old man who had a complaint of a mass in his right mental region is presented. The patient was unable to wear his prosthesis because of an underlying swelling. An incisional biopsy was performed. Microscopic examination of the surgical specimen revealed large epithelial islands of ameloblast-like cells within increased, dense, collagenous desmoplastic stroma. Histopathologically, it was diagnosed as DA. Under local anesthesia, the lesion was enucleated. There was no recurrence after 32 months of follow-up.

Aged↗