Event-related Potential Patterns Reflect Reversed Hemispheric Activity during Visual Attention Processing in Children with Dyslexia: A Preliminary Study

OBJECTIVE: Individuals with dyslexia experience reading difficulties, whereas their other cognitive abilities seem normal. The purpose of this study was to investigate the event-related potential (ERP) patterns of children with dyslexia during a target-detection task. METHODS: Seventeen children with dyslexia and 18 children without this disorder participated in this study. We evaluated their writing and reading ability, symptoms of attention-deficit/hyperactivity disorder, and intelligence quotient. ERPs were recorded while participants performed a target-detection task, and the peak amplitude and latency of P100 and P300 were analyzed. The lateral asymmetry index (LAI) was calculated for each ERP component. RESULTS: The dyslexic group exhibited longer reaction times and larger P100 amplitudes than the non-dyslexic group in the right hemisphere. The P100 latency was also significantly delayed in the right hemisphere of those in the dyslexic group compared with those in the non-dyslexic group. The P300 amplitude was larger in the right hemisphere compared with left hemisphere in the dyslexic group, whereas no interhemispheric differences were observed with respect to the P300 latency. The LAI for P100 showed a significant right hemispheric dominance, whereas the LAI for P100 was significantly correlated with the accuracy of target detection in children with dyslexia. CONCLUSION: Our results suggest that right hemispheric dominance acts as an ancillary system that compensates for poor reading in children with dyslexia.

Central Corneal Thickness and Corneal Endothelial Cell Changes Caused by Contact Lens Use in Diabetic Patients

PURPOSE: To analyze the effects of soft contact lenses on central corneal thickness and morphologic characteristics of the corneal endothelium in diabetic patients. MATERIALS AND METHODS: Ultrasound pachymetry and noncontact specular microscopy were performed on 26 diabetic patients who regularly use soft contact lenses (group 1), 27 diabetic patients who do not use soft contact lenses (group 2) and 30 normal subjects (group 3). We compared the values in each group using the Mann-Whitney test. RESULTS: The central cornea was found to be thicker in diabetic patients, both those who use and do not use contact lenses, than in the normal control group. The central corneal thickness was significantly higher in group 1 (564.73 +/- 35.41 microm) and group 2 (555.76 +/- 45.96 microm) than in the control group (534.05 +/- 27.02 microm), but there was no statistically significant difference between groups 1 and 2. Endothelial cell density was significantly different between the groups, and was smallest in the group of diabetic patients using contact lenses. The coefficient of variation of cell size was significantly higher and the percentage of hexagonal cells was significantly lower in contact lens using diabetic patients than in non-contact lens using diabetic patients and in the control group. CONCLUSION: Central corneal thickness and endothelial cell density is more affected by diabetes mellitus, and corneal endothelial cell morphology is more affected by contact lens use, when compared with normal subjects.

Morphological Analysis of Papillary Retinal Vessels and Retinal Nerve Fiber Layer in Koreans

PURPOSE: The study present the central retina arterial supply, optic disc shape, RNFL (retinal nerve fiber layers) thickness and optic disc rim area. METHODS: To evaluate the relationship between central retina artery pattern, optic disk shape, and RNFL thickness was measured using optical coherence tomography (OCT3000) and pattern of the central retinal artery were investigated by TRC50IX. Healthy Koreans (107 males, 97 females) were enrolled in this study. The classification is made by dividing surface of the nerve head into ten sector. RESULTS: As a result of the shape of the optic disc divided into four group, vertically oval were 54%. The results showed the central retinal artery, in 252 eyes, had its origin in the center. None of the eyes had their origin on temporal side. RNFL thickness according to OCT parameter was superior, 127.68+/-16.16 micrometer; temporal quadrants, 79.60+/-16.05 micrometer; inferior quadrants. CONCLUSIONS: In summary, this study indicates that in healthy Koreans the shape of the optic disc is vertically oval and the origin of their central retinal artery is at the center. The RFNL thickness of both the superior and inferior quadrants was 127 micrometer according to OCT.

Age-related Alterations of Bcl-2, Bax and Apoptosis in Ischemic-reperfused Rat Tibialis Anterior Muscles / 체질인류학회지

Prolonged ischemic-reperfusion induces cellular damages and apoptosis in rat skeletal muscle. Such injury takes place in the phase of reperfusion following ischemia induction in part via regulating of apoptosis-related gene inductions. Among apoptosis-related gene products, Bcl-2 and Bax regulate the apoptotic response by inhibiting and promoting cell death, respectively. The present study was performed to examine the age-related alertation of expression of Bcl-2 and Bax along with apoptosis in rat tibialis anterior muscles following ischemia-reperfusion. 9 weeks, 30 weeks and more than 65 weeks old male Sprague-Dawley rats were divided into 2 groups such as controls, 4 hour ischemia. 4 hour ischemia group was divided into 3 subgroups based on reperfusion time. For ischemia, left commom iliac artery was occulded for 4 hours. The tibialis anterior muscles were removed 0, 3, and 24 hours after onset of reperfusion. Muscle samples were embeded in paraffin and 6 micrometer sections were made. The expression level of Bcl-2 and Bax were examed using immunohistochemical methods and apoptotic reactions was detected using TUNEL methods. The results obtained were as follows; 1. In control group, Bcl-2 and Bax were weakly immunostained in 9 weeks old rat tibialis anterior muscles. In 30 and 65 weeks old rat tibialis anterior muscles, Bcl-2 immunostaning was minimal. The level of Bax staining was increased in 30 and 65 weeks old rat tibialis anterior muscles, compared with those of 9 weeks old rats. The level of apopto-sis among different age groups were not altered. 2. In the 4 hour ischemia group, the level of Bax staining was correlated with the level of apoptosis in 9 weeks, 30 weeks and 65 weeks old rat tibialis anterior muscles. 3. The level of apoptosis was increased in older groups relative to younger groups in 4 hour ischemia. These results suggested that the level of apoptosis induced by ischemic-reperfusion in tibialis anterior muscle increase with ageing in rat tibialis anterior muscles, and that a increase of Bax expression is related to increased apoptosis.

Characteristics and Arterial Distribution of Rectus Femoris Muscle in Korean / 체질인류학회지

Free -flap which is transferred to recipients is a thin flat tissue isolated from human body and nutrient vessel of free - flap is ligated with similarly sized vessel. Free -flap reconstruction is widely used, due to high rate of flap survival and functional refinements, although it gives disadvantage of long surgery time and inefficient adaptation. This study demonstrates the characteristics and arterial supply of rectus femoris muscle of thigh. Seventy thighs (35 right, 35 left) of the 35 cadavers (19 males/16 females) which were clinically normal and without deformity were dissected and measured, according to Martin measurements. 1. The average length and width of rectus femoris muscle were 396.7 +/-39.9 mm and 36.5 +/-7.9 mm, respectively. The length of female subjects was significantly different from that of male subjects (P 0.05). 2. In the origin and insertion of rectus femoris muscle, anterior tendon and posterior tendon were not different between female and male subjects. 3. Artery of the rectus femoris muscle arises from deep femoral artery. The length of pedicle from the entering point of the rectus femoris muscle was average 19.0 +/-11.9 mm. The length from the entering point of the rectus femoris muscle to spliting point was 13.7 +/-7.7 mm of P1, 12.6 +/-7.5 mm of P2, and 14.8 +/-11.63 mm of P3 pedicles. 4. The frequency of the blood vessels inserted into the rectus femoris muscle was the first highest at the portion of 32.5 ~35% and the second highest of 35 ~37.5% and 37.5 ~40% ranges, when anterior superior iliac spine from center of the patellar was considered as 100% of portion. 5. According to the method by Kimata et al. (1998) classifying perforators based on the anatomic variations, type 1 and VIII were 83.58% and 5.97% respectively. Type 5, 6 and 7 were not observed. 6. Femoral nerves inserted into the rectus femoris muscle were distributed within 7.5 ~45% portion when anterior superior iliac spine from center of the patella was converted into 100%. The portion of 17.5 ~20% had the highest frequency of nerves. In conclusion, length of the rectus femoris muscle in Korean were different depending on gender, whereas tendon lengths were not. These data demonstrate artery pattern in Korean and provide anatomical potential for rectus femoris muscle to be used as a free -flap muscle.

Selective Susceptibility of Synovial Fibroblasts Isolated from Patients with Rheumatoid Arthritis to TRAIL -induced Cell Death / 체질인류학회지

TNF -related apoptosis inducing ligand (TRAIL) is a member of TNF ligand superfamily. TRAIL transduces death signal through two distinct receptors, TRAILR -1I and TRAILR -2, while the engagement of TRAILR -3 and TRAILR -4 interferes with TRAIL -induced apoptosis. The profile of TRAILR expression has been reported to be a mechanism by which transformed cells undergo apoptosis in response to TRAIL while normal cells do not. Rheumatoid arthritis (RA) is an inflammatory autoimmune disease which is characterized by the hyperplasia of synovial membrane. The dysregulation of apoptosis in synoviocytes has been suggested to contribute to synovial hyperplasia. Synovial fibroblasts obtained from patients with RA have been reported to exhibit several semi - transformed aspects. To investigate whether RA synovial fibroblasts acquire the susceptibility to TRAIL -induced apoptosis, synovial fibroblast lines obtained from 2 RA patients and two osteoarthritis (OA) patients were cultured in the presence of recombinant human TRAIL and followed by MTT assay. TRAIL treatment resulted in a significant decrease in the viability of both lines of RA cells, indicating TRAIL -induced cell death of RA synovial fibroblasts, whereas OA synovial fibroblasts and normal human dermal fibroblasts were either resistant or less sensitive to TRAIL as compared with RA synovial fibroblasts. In RT -PCR analyses, the expression levels of TRAILR 4 in RA synovial fibroblasts were lower than in OA synovial fibroblasts, while other receptors in both cell lines were expressed at comparable levels. Immunohistochemical studies showed that in RA synovial tissues TRAILR -3cells were mainly leukocyte infiltrates, implying that such leukocyte infiltrates play a role in the perpetuation of the disease. Taken together, these results suggest that RA synovial fibroblasts acquire the susceptibility to TRAIL -induced cell death during disease progression and this death signal may be regulated by, at least in part, differential expression of TRAILR -4 molecule.