Correlations between the Thickness of the Mandible and the Bone Mineral Density according to the Dentition / 체질인류학회지

The morphometric data which reflect the quality and quantity of the mandible are very important to the surgeon for the mandible. It is very useful clinically to predict the status of the mandible indirectly by other medical examinations. This study was undertaken to clarify the correlations of the mandible and dentition to predict the thickness and bone mineral density of the mandible. Sixty-one mandibles (32 M/29 F, mean age: 66.72 years) obtained from the collection of the Department of Anatomy and Cell Biology of Hanyang Medical College were analyzed. The bone mineral density was measured by dual energy X-ray absorptiometry. In the mandible, bone mineral densities at the mandiblular angle, between molars and premolars, around incisors and the thickness, and the length at the sections through the 1st and the 2nd molars were measured. The data were analysed with SPSS 12.0 program (One-Way ANOVA) according to age, gender and dentition, to verify the statistical significance and the correlation between the thickness and bone mineral densities. The obtained results were as follows. 1. The bone mineral density in the mandibular areas were variable, but statistically insignificant except incisor area. The bone density of the mandible was highly correlated with the thickness of cortical bones and the highest correlation coefficient was shown in sum of the thickness of buccal and lingual cortical bone (correlation coefficient, r=0.622) 2. The thickness of cortical bones at the sections through the molars in the man were greater than those in the woman. The correlation coefficient between the thickness and bone mineral density at the molars were greater in the woman. 3. The bone mineral density of whole mandible, the thickness of lingual and basal cortical bones and the height of alveolar ridge were significantly higher in the specimens with both of the 1st and 2nd mandibular molar teeth. The results of this study represents the significant differences of bone mineral density in the mandible according to gender and dentition and also the significant correlation between the bone mineral density and the thickness of cortical bone.

Effects of Repetitive Ischemic Preconditioning on the Expression of Cu,ZnSOD and MnSOD in Rectus Femoris Muscles of Rats / 체질인류학회지

The present study was performed to investigate the dynamics of Cu,ZnSOD and MnSOD expression following courses of reperfusion after repetitive ischemic preconditioning on the left rectus femoris muscle of Spraque-Dawley rats. Nine or thirty five weeks-old rats were subjected to three, six and ten cycles of ischemic preconditioning that was 5 min ischemia and 5 min reperfusion at the left common iliac artery. Left rectus femoris muscle was isolated 0, 3, 6, 24 and 72 hours of reperfusion after ischemic preconditioning and assayed by immunohistochemical staining with anti-Cu,ZnSOD and anti-MnSOD antibodies. The results were as follows; The immunoreactivities of Cu,ZnSOD and MnSOD were increased in the repectitive three and six cycles of ischemic preconditioning. However, after the repetitive ten cycles of ischemic preconditioning, the Cu,ZnSOD immunoreactivities were decreased in the nine weeks-old rats while MnSOD immunoreactivities were decreased in thirty five weeks-old rats. These findings suggest that severe damayes result from decrease of Cu,ZnSOD in nine weeks-old rats and decrease of MnSOD in thirty five weeks-old rats after ten cycles of ischemic preconditioning.

Expression Pattern of Nitric Oxide Synthases in Rat Skeletal Muscle after Cyclic Episodes of Short Ischemia and Reperfusion / 체질인류학회지

The ischemic preconditioning was initially identified as a protective maneuver induced by brief periods of ischemia followed by reperfusion. Although ischemic preconditioning can reduce ischemic injury of heart, skeletal muscle and neuronal tissue, it's protective mechanism remains elusive. Recently, several investigations suggest the associations of nitric oxide with protection from ischemic injury. Nitric oxide synthesized by a member of nitric oxide synthase (NOS) family has been known to increase or decrease the ischemic injury. The purpose of this study was to observe the expression patterns of NOS 1, NOS 2 and NOS 3 in the rat skeletal muscle after cyclic episodes of short ischemia and reperfusion. Nine and thirty-five weeks-old male Sprague-Dawley rats were divided into control and cyclic short ischemia and reperfusion groups. The experimental group was further divided into 3 groups based on cycles of short ischemia and reperfusion. For cyclic short ischemia and reperfusion, left commom iliac artery was occluded 3, 6 and 10 times for 5 minutes ischemia followed by 5 minutes reperfusion using rodent vascular clamps. The animals were sacrificed at hours 0, 3, 6, 24 and 72 after reperfusion and the left rectus femoris muscles were removed. The expression profiles and distribution of NOS 1, NOS 2 and NOS 3 were examined with immunohistochemical staining. The results were as follows; In the cyclic of short ischemia and reperfusion groups, the mortality was increased with increasing of cyclic episodes at 72 hours after reperfusion, and aging. In the control group, NOS 1, NOS 2 and NOS 3 immunoreactivities showed no differenes with aging. In the 9 weeks-old rats, NOS 1 immunoreactivities were observed moderate at 24 hours after 6 times of short ischemia and reperfusion, and moderate and strong at 24 hours after 10 times of short ischemia and reperfusion. In the 35 weeks-old rats, NOS 1 immunoreactivities were observed trace or mild at 24 hours after 6 and 10 times of short ischemia and reperfusion. At 3 hours after 3 times of short ischemia and reperfusion, NOS 2 immunoreactivities were observed moderate or strong, and trace in the 9 and 35 weeks-old rats, respectively. At 3 hours after 10 times of short ischemia and reperfusion, NOS 3 immunoreactivities were observed mild or moderate, and trace or negative in the 9 and 35 weeks-old rats, respectively. In summary, the expression profile of NOS 1, NOS 2 and NOS 3 were observed differently with increasing episodes of short ischemia and reperfusion. The alteration was the most prominent in NOS 3 than in NOS 1 and NOS 2. These results suggest that the alteration of NOS 3 known to protect tissue against ischemic injury may be associated with increasing mortality after multiple episodes of short ischemia and reperfusion.