Tehran University Medical Journal

The study was conducted to determine the clinical pattern and etiology of cerebral venous thrombosis in Iran. Records of all adult patients admitted with a clinical diagnosis and MRI of cerebral venous thrombosis from 1993 through 1999 in three major hospitals of Tehran, Iran were reviewed. Fifty patients (39 women, 11 men) aged 14 to 56 years were identified. Headache the most frequent and often the earliest symptom, was encountered in 82 percent and papilledema, the most frequent sign in 56 percent of cases. Infection was the cause of cerebral venous thrombosis in 26 percent of our cases. Other causes included oral contraceptive (32 percent), vasculitis (6 percent), Behcet's disease (4 percent), postpartum state (4 percent), myeloproliferative disease (2 percent), ulcerative colitis (2 percent), antithrombin III deficiency (2 percent) and diabetic ketoacidosis (2 percent). Oral contraceptive was recognized as the most common etiology. Infection is an important cause whereas procoagulation disorders are uncommon.

Background: This study was designed to investigate the process of bone formation caused by implantation of octa calcium phosphate (OCP) in rat tibiae.

Methods: We used 25 young male Sprague-Dawley rats. A full thickness standardized trephine defect, 3-mm in diameter, was surgically created on the superior end of right and left tibia. Amount of 6-mg synthetic Octa calcium Phosphate was implanted into a bony defect on the right tibia as a experimental group. No OCP particles were implanted in the left tibia as a control group that was otherwise treated identically. Bone formation was examined histologically on 7th, 10th, 14th, 21st, 28th days after implantation.

Results: In the experimental group, on the 7th day after implantation, a few clusters of cartilage cells were observed between the OCP particles near the defects margin. Osteogenesis was initiated locally between the OCP particles in central position of the defects on 10th day after implantation. By 14th day after implantation, Alcian blue staining showed hypertrophic chondrocytes that replaced by new bone. In addition to bone formation locally around the OCP particles, more apposition of new bone was observed near the defects margin on 14th and 21st days after implantation. At the end of study implanted OCP was surrounded by newly formed bone. In the control group, at the end of study, bone formation was observed only along and near the defects margin.

Conclusion: These results demonstrate that octa calcium phosphate could be used in the repair of the long bone defects.