In order to understand the pathogenesis and progression of some synaptic loss related neuropsychiatric diseases. We attempted to develop a computer model in this study. We made a simple autoassociative memory network remembering numbers, transformed it into a disease model by pruning synapses, and measured its memory performance as a function of synaptic deletion. Decline in performance was measured as amount of synaptic loss increases and its mode of declines is sudden or gradual according to the mode of synaptic pruning. The developed computer model demonstrated how synaptic loss could cause memory impairment through a series of computer simulations, and suggested a new way of research in neuropsychiatry.
Computer Simulation* ; Dementia ; Memory ; Neuropsychiatry ; Schizophrenia ; Synapses

No abstract available.

PURPOSE: To investigate the regional characteristics and the factors that influence final visual acuity in corneal laceration and use the results for prevention and treatment of corneal laceration. METHODS: Sixty-eight patients who visited the Chosun University Medical Center from January 1, 2006 to December 31, 2010 were retrospectively surveyed. The incidence of corneal laceration, sex, age, monthly and seasonal distribution, cause, site and length of corneal laceration, secondary operation, complications, and ocular trauma score were reviewed statistically. In additional, the factors influencing visual prognosis were investigated. RESULTS: The incidence was more common in males (94.1%) and in the 6th-decade of life (29.4%). The corneal laceration was more common in the summer (38.2%) and in September (26.5%) and the most common cause was stone (39.7%) and metal (35.3%), respectively. The corneal laceration tended to occur at the corneal center. The most common first operation was primary closure (81.9%), and the secondary operation was most often performed due to a traumatic cataract (32.1%). The factors that significantly influenced the final visual acuity were initial visual acuity, length and site of laceration, and secondary operation. CONCLUSIONS: The present survey investigated the regional characteristics and important factors influencing final visual acuity. Results show initial visual acuity, the length and site of laceration, and the secondary operation significantly influenced final visual acuity.
Academic Medical Centers ; Cataract ; Humans ; Incidence ; Lacerations ; Male ; Prognosis ; Retrospective Studies ; Seasons ; Visual Acuity

The purpose of this study was to aid in the use of the digital images by edge-detect interpolation for direct digital periapical images using edge-deted interpolation. This study was performed by image processing of 20 digital periapical images; pixel replication, linear non-interpolation, linear interpolation, and edge-sensitive interpolation. The obtained results were as follows ; 1. Pixel replication showed blocking artifact and serious image distortion. 2. Linear interpolation showed smoothing effect on the edge. 3. Edge-sensitive interpolation overcame the smoothing effect on the edge and showed better image.
Artifacts

No abstract available.
Humans ; Infant* ; Parturition*

The purpose of this study was to compare E-speed film, CDR, and modified CDR images by means of observing some artificial defects of alveolar bone wall in the sound human dried mandibles. High diagnostic accuracy was shown in 1 wall and 4 wall defects by all 5 observers (2 Radiologists, 2 Periodontists, 1 General practitioner), but the diagnosis in 2 wall and 3 wall defects was inaccurate. Modified CDR images had the more diagnostic accuracy than E-speed film and CDR images, but there was no statistical difference among them. Finally, radiologist used modified CDR images more than others and used equalization effect more than the change in contrast and/or brightness.
Diagnosis ; Humans ; Mandible ; Radiographic Image Enhancement*

The purpose of the present study was focused the anthropometric charateristics of normal Korean eyes, including inclination, height, width, epicanthus and upper eyelid crease. The author measured normal eyes and investigated incidence of epicanthal fold and upper eyelid crease in 774 males and 658 females with photographs. The epicanthus were classified by three types and the upper eyelid crease were classified by four types. The angle of inclination of eyes was larger in females than males and in young ages than old ages. Incidence of the slanting eye over 10 degree was 34.1 % in males and 41.0% in females. Incidence of the epicanthal fold was 57.0%, and there was no difference between males and females. The most common type of the epicanthal fold was type I. Incidence of the upper eyelid crease was 30.9% in males, 47.2% in females. The most common type of the upper eyelid crease was parallel (or floating) type. In conclusion, the anthropometric characteristics of normal Korean or oriental eyes are apart each other and slanting eyes in addition to puffy eyelid, narrow palpebral fissure, presence of epicanthal fold and absence of upper eyelid crease.
Eyelids ; Female ; Humans ; Incidence ; Male

The purpose of this study was to evaluate the Waters' views, panoramic and periapical radiograms as well as clinic al symptoms in the diagnosis of maxillary sinusitis. The author analyzed the types of mucosal thickenings, the types of bony wall changes, the pathologic changes of antra l floors and total amount of agreement on radiograms in 495 patients with 505 maxillary sinuses which demonstrated radio graphic changes. The results were obtained as follows : 1. 125 cases (24.8%) showed the mucosal thickening of antral floor and lateral wall(Type II), 106 cases (20.9%) showed the mucosal thickening around the whole antral wall(Type IV) and 75 cases (14.8%) showed increased radiopacity of whole antrum. 2. Among 505 cases of mucosal thickening, 319 cases(63.2%) showed the bony wall changes: 114 cases (35.9%) showed the thining of lateral walls, 105 cases(32.8%) showed the thickening of lateral walls and 47 cases(14.7%) showed indistinct antral walls. 3. Among 6 types of mucosal thickenings, the incidence of bony wall changes was high in type VI(73.3%) and in type IV(7 1.6%). 4. 139 cases(25.1%) showed no pathologic change of antral floor, 127 cases(22.9%) showed the indistinct antral floor an d 022 cases (22.1%) showed the halo appearance of antral floor on panoramic and periapical radiograms. 5. 449 cases(88.9%) showed apparent increased radiopacity and 47 cases(9.3%) showed suspicious increased radiopacity on Waters' views. 280 cases(71.6%) showed apparent increased radiopacity and 88 cased (22.5%) showed suspicious increased radiopacity on panoramic radiograms. And 141 cases(31.6%) showed apparent increased radiopacity and 133 cases(33.4%) showed suspicious increased radiopacity on periapical radiograms.
Diagnosis ; Humans ; Incidence ; Maxillary Sinus* ; Maxillary Sinusitis*

The purpose of this study was to evaluate the Waters' views, panoramic and periapical radiograms as well as clinic al symptoms in the diagnosis of maxillary sinusitis. The author analyzed the types of mucosal thickenings, the types of bony wall changes, the pathologic changes of antra l floors and total amount of agreement on radiograms in 495 patients with 505 maxillary sinuses which demonstrated radio graphic changes. The results were obtained as follows : 1. 125 cases (24.8%) showed the mucosal thickening of antral floor and lateral wall(Type II), 106 cases (20.9%) showed the mucosal thickening around the whole antral wall(Type IV) and 75 cases (14.8%) showed increased radiopacity of whole antrum. 2. Among 505 cases of mucosal thickening, 319 cases(63.2%) showed the bony wall changes: 114 cases (35.9%) showed the thining of lateral walls, 105 cases(32.8%) showed the thickening of lateral walls and 47 cases(14.7%) showed indistinct antral walls. 3. Among 6 types of mucosal thickenings, the incidence of bony wall changes was high in type VI(73.3%) and in type IV(7 1.6%). 4. 139 cases(25.1%) showed no pathologic change of antral floor, 127 cases(22.9%) showed the indistinct antral floor an d 022 cases (22.1%) showed the halo appearance of antral floor on panoramic and periapical radiograms. 5. 449 cases(88.9%) showed apparent increased radiopacity and 47 cases(9.3%) showed suspicious increased radiopacity on Waters' views. 280 cases(71.6%) showed apparent increased radiopacity and 88 cased (22.5%) showed suspicious increased radiopacity on panoramic radiograms. And 141 cases(31.6%) showed apparent increased radiopacity and 133 cases(33.4%) showed suspicious increased radiopacity on periapical radiograms.
Diagnosis ; Humans ; Incidence ; Maxillary Sinus* ; Maxillary Sinusitis*

BACKGROUND: Centrotemporal spikes (CTS) are the hallmark of the syndrome of benign childhood epilepsy with centrotemporal spikes or Rolandic seizures. However, they also can be encountered in other symptomatic epilepsies or may incidentally be found in non-epileptic children with or without neurological symptoms. We investigated clinical and electroencephalographic characteristics of children with CTS on EEG. METHODS: A 7 year material of children with CTS on EEG were reviewed. Sixty-eight children were found. RESULTS: Among them, 55 patients exhibited recurrent rolandic seizures of benign course (so-called benign rolandic epilepsy ; BRE), 9 children suffered from chronic headache without clinical seizure, three patients showed multiple types of seizures or rolandic seizures with some degree of mental retardation, and one child was asymptomatic. In 55 BRE cases, seven children (13%) had a preceding history of febrile convulsions, and a positive family history of epilepsy was found in 9 patients. Generalized spike and wave discharges were observed in 9 patients (16.7%), but none of them experienced clinical absence seizure. In 25 of 29 BRE patients who showed overt lateralized ictal manifestations on history, symptoms were correlated with the main foci of spike discharges. Of the nine children, found to have CTS during evaluation of chronic intermittent or daily headache, the headache was successfully controlled by antiepileptic drugs in two cases. CONCLUSION: Most children with CTS were compatible to the BRE without any causative lesional factor. However, nonepileptic cases were not uncommon and, though rare, atypical cases were also present in children with CTS on EEG.
Anticonvulsants ; Child* ; Electroencephalography* ; Epilepsy ; Epilepsy, Absence ; Epilepsy, Rolandic ; Headache ; Headache Disorders ; Humans ; Intellectual Disability ; Seizures ; Seizures, Febrile