Gender Difference on Corpus Callosum in Korean Adults / 체질인류학회지

Corpus callsoum (CC) is the largest commissural fiber connecting the cerebral hemispheres. The gender difference in the size or the shape of CC is a long standing dispute. Some reported that adult female CC had more bulbous splenium and larger area considering brain size, but others failed to replicate this findings. There is no definite consensus on sexual dimorphism of CC yet, although extensive studies on sexual dimorphism has been expected to provide a clue to explain sociopsychological differences between male and female. This variable results are attributed to limited number of subjects, measured parameters, and method of measurement. We have employed comprehensive analytic parameters with large subjects to understand gender differences on CC of healthy Korean adults. We have analyzed the magnetic resonance image (MRI) in adults free from neurological disorders. The subjects were composed of 108 young people (3rd decade; male : 51, female : 57). Total area, its 5 sub-areas, linear parameters including height, length, and width and five specific angles of the CC were measured on the midsagittal MR images with NIH Image program (R) (Ver 1.6). The gender differences were observed in the area of splenium and length in the group. The male CC have larger splenium and longer length than female. The angle between neural axis and base of corpus callosum in female was significantly larger than that of male. This study reports not only gender difference of adult CC, but Korean adult standard morphometric data of CC research. These results might serve a useful basic data for various research in the fields of neuroanatomy, neuroradiology, and neuropsychiatry.

The Effect of Low Level Laser on the Fracture Healing in Guinea Pig Femur / 대한정형외과연구학회지

PURPOSE: This study was conducted to evaluate the effectiveness of the low level laser on the fracture-healing of the guinea pig femurs. MATERIALS AND METHODS: This study was performed on 36 guinea pigs(17 in the experimental group and 19 in the control group). After anesthesia of the guinea pigs, the shaft of femur was fractured with Gigli saw under aseptic conditions, and then the intramedullary nailing of K-wire was performed. The application of low level laser on the fracture sites in the experimental group began 2 days after the operation under anesthesia, for 30 minutes every 2 days. The laser we used was a CW-type microchip laser with output wave length of 890 nm and intensity of 13 mWatts, measuring upto 4.68 J/cm2 per each application. In order to compare the femur fracture healing process of both groups; gross findings, simple radiologic findings, and histologic findings of fracture site stability were evaluated. The simple radiologic and histologic findings were assessed by the scoring system invented by Zorlu and his colleagues. The statistical evaluation was done by using repeative measured ANOVA test. RESULTS: In both experimental and control groups, the gross findings progressed favorably. Although the improvement in radiologic findings were found in both groups with the passage of time, the experimental group showed a greater rate of callus formation with statistical significance(p<0.0) compared to the control group. The result of histological findings showed that a increase of osteoblastic proliferation was also greater in the experimental group(p<0.01). CONCLUSION: In this study, the low level laser was revealed to be effective on acceleration of femur fracture healing in guinea pigs.

Immunohistochemical Study on the Nitric Oxide Synthase in the Developing Rat Brain / 대한해부학회지

Nitric oxide(NO) is thought to play an important role in development and plasticity of brain. In this study, we aimed to examine the expression of neuronal NOS and NADPH-diaphorase (NADPH-d) activity in the developing rat brain. The results show that there is a great variation in the time of appearance of the earliest NOS containing cells depending on their location: At the 15th embryonic day weakly stained cells were present in caudate-putamen, and neurons in the sensory trigeminal nucleus and the solitary nucleus displayed an intense staining. The NOS neurons in orbital neocortex, bed nucleus of stria terminalis, paraventricular hypothalamic nucleus, lateral hypothalamic area and mammillary body appeared first at the 18th embryonic day. The supraoptic nucleus and superior and inferior colliculi also weakly labeled at the 18th embryonic day, At the loth embryonic day, positive cells appeared in horizontal limb of diagonal band, anterior olfactory nucleus and parafascicular thalamic nucleus. In the cerebellum, weak NOS staining was present in fibers and cells situated below Purkinje cert layer. The Purkinje cell layer displayed a weak, rather diffuse activity throughout the cerebellum at postnatal day 0. At the 4th postnatal day. the reaction product in the Purkinje cell layer became more distinct. At the 10th postnatal day, the inner part of molecular layer became populated by NOS positive basket cells, and the reaction products on the Purkinje cells began to disappear. The present results showed that NOS in the rat brain is expressed in different populations of neurons at different stages of development. This expression pattern of NOS suggests that NO may play a role in the developmental remodelling of the mammalian brain.