A new method is described which uses photo-electric matrix method to measure two-dimensional eye movements. This system is composed of the detector unit (monitor), matrix and correction circuits and stimulus generator. A light and small detector unit attached to the modified trial frame transduces positional informations and can be achieved head-mounting. The instrument operates in the infrared, so that it does not interfere with normal vision, and over a two-dimensional visual field to +/-15 degrees. A system for generating a fixed target whose velocity, displacement, form, intensity, and other characteristics can be varied systematically also is described. The operating procedures are described and operating records are shown. Electrical and optical modifications of the present system will make possibIe the measurement of more smaller movement of the eye. Extensions and improvement of the technique of measurement are discussed briefly.
Eye Movements* ; Visual Fields

The saccadic reaction times to the double-step stimuli were studied in three human subjects to ascertain the saccadic visual tracking characteristics. Responses to simple step and double-step target motions were measured where the target mode and stimulus durations were randomized. To measure the eye movement the Photo-electric Eye Monitor was constructed based on limbus tracking. The results indicate that observers represented two kind of responses (A-or B-type) depending upon the stimulus duration. The percentage of occurrances increased as the stimulus duration increased from 50 to 200 msec. When the subject responded to both target motions, the reaction time of the second saccade was shorter than that of the first. The successive visual information is to change continuously the reaction time or cancel the initial saccade. Our results revealed that parallel data processing characteristics of the visual tracking systems and the saccadic decision-makings are influenced by the temporal relationships.
Adult ; Eye Movements* ; Human ; Male ; Motion Perception* ; Reaction Time* ; Saccades* ; Visual Perception*

BACKGROUND: We performed electrical cardioversion for the patients with chormic nonvalvular atrial fibrillation under the transesophageal echocardiographic guidance after anticoagulation to evaluate the safety of this procedure and the effects of electrical cardioversion on the atrial function. METHODS: After anticoagulation therapy with coumadine for three weeks, we tried chemical cardioversion with amiodarone first. Failed cases were included in this study. Pre-cardioversion transesophageal echocardiographic parameters were measured after exclusion of thrombi. After sedation with intravenous midazolam, direct-current cardioversion was done with the transesophageal echocardiographic probe in situ. Immediately after sinus conversion, we measured echocardiographic parameters again. Spontaneous echo contrast(SEC), left atrial appendage flow velocity, pulmonary vein flow velocity and time-velocity-integral(TVI), transmitral flow velocity, TVI and deceleration time were measured. All patients were anticoagulated for at least 4 weeks after cardiovesion. RESULTS: The total number of patients was forty one(24 males, 17 females) with the mean age of 58 years(range : 39-70). Mean duration of atrial fibrillation was 65 months(range : 1-360). Hypertension(12), dilated cardiomyopathy(10), cerebrovascular accidents(6), ischemic heart disease(2) and chronic lung disease(1) were associated. There were no complications. SEC increased or newly appeared in 18(43.9%) patients after sinus conversion. The left atrial appendage emptying velocity decreased(32.8+/-17.4 vs. 22.1+/-11.4cm/sec, p=0.020) and systolic TVI of both upper pulmonic vein increased significantly after sinus conversion. In two cases, early systolic forward flow(S1) of pulmonic vein appeared after sinus conversion. Transmitral E velocity decreased(86.9+/-28.8 vs. 76.3+/-30.6cm/sec, p=0.006) and the deceleration time increased(164+/-49 vs. 206+/-53msec, p=0.000) after sinus conversion. Transmitral A velocity was still low(34.9+/-19.5cm/sec) and E/A ratio was high(2.6+/-1.4) immediately after sinus conversion. CONCLUSION: After appropriate anticoagulation therapy and exclusion of left atrium and left atrial appindage thrombi with TEE we could perform electrical cardioversion safety without complications. The changes in transesophageal echocardiographic parameters after sinus conversion revealed the appearance of atrial mechanical activity in concordance with electrical activity. But these findings suggested atrial stunning or electromechanical dissociation which necessitates extended anticoagulation therapy until the full recovery of atrial mechanical function.
Amiodarone ; Atrial Appendage ; Atrial Fibrillation* ; Atrial Function ; Deceleration ; Echocardiography* ; Echocardiography, Transesophageal ; Electric Countershock* ; Heart ; Heart Atria ; Humans ; Lung ; Male ; Midazolam ; Pulmonary Veins ; Veins ; Warfarin

A massive pulmonary embolism occurring during surgery is a fatal complication. Therefore, early detection and subsequent treatment of pulmonary emboli are important clinical challenges. In this report, an acute pulmonary embolism associated with cardiac arrest occurred during the surgical reduction of a femur fracture. It was diagnosed by echocardiography and treated with urokinase successfully. Therefore, we recommend the use of urokinase for the treatment of a intraoperative massive pulmonary embolism.
Echocardiography ; Femur* ; Heart Arrest ; Pulmonary Embolism* ; Urokinase-Type Plasminogen Activator*

OBJECTIVE: Anti-glucose-6-phosphate isomerase (GPI) antibody (Ab) is known to be arthritogenic in K/BxN mice. Anti-GPI Ab is present in some patients with rheumatoid arthritis (RA), but their clinical manifestations are not clearly elucidated. The purpose of this study was to evaluate whether GPI serves as a specific autoantigen in patients with RA and to investigate the relationship of anti-GPI Ab with clinical parameters of RA. METHODS: Sera were collected from 54 patients with RA, 15 patients with osteoarthritis (OA) and 28 healthy controls. The samples were tested by enzyme-linked immunosorbent assay (ELISA) using human recombinant GPI as antigen. Patients with RA were classified according to rheumatoid factor (RF) positivity, the presence of RA shared epitope (SE), the presence of extraarticular manifestations, and evidence of bony erosive changes. RESULTS: Serum levels of anti-GPI Ab were higher in patients with RA than controls (1599.46+/-1022.48 versus 344.82+/-223.16 AU, p<0.001), and the levels of patients with OA were also higher than controls (1161.47+/-917.44 versus 344.82+/-223.16 AU, p<0.01). In RA, there were no significant difference in anti-GPI Ab levels according to RF positivity, the presence of RA SE, the presence of extraarticular manifestations, and evidence of bony erosive changes. CONCLUSION: Our results suggest that anti-GPI Ab may not be RA specific Ab and not related to the severity of RA.
Animals ; Arthritis, Rheumatoid* ; Autoantibodies* ; Enzyme-Linked Immunosorbent Assay ; Glucose-6-Phosphate Isomerase* ; Glucose-6-Phosphate* ; Humans ; Mice ; Osteoarthritis ; Rheumatoid Factor

Objectives: There was no previous report about the electrical cardioversion for the patients with atrial fibrillation after successful percutaneous ballon mitral valvuloplasty (PBMV). We performed electrical cardioversion after PBMV to evaluate the effectiveness of this procedure in the view of conversion to and maintenance of the sinus rhythm. METHODS: 28 patients who had persistent atrial fibrillation after successful PBMV were included in this study. All patients were anticoagulated with warfarin. Amiodarone was loaded and maintained before cardioversion. The PBMV procedures were guided by transesophageal echocardiography in all patients. Transthoracic echocardiography was done before and after PBMV and cardioversion, and was followed. RESULTS: The number of patients were 28 (male 9 and female 19) within the mean age of 50.3+/-12.0 years (24-66). Initially 24 patients (86%) succeeded in electrical cardioversion. The energy required for successful conversion was 230+/-75J, on average. There were no complications except for the transient sinus bradycardia in 2 cases. The mean follow-up duration was 357+/-144 days and when followed-up, the sinus rhythm was maintained in 15 patients out of 24 with initial success (63%). No factor was significantly related to the success of cardioversion, but left atrial dimension after 1 month of PBMV was significantly related to the maintenance of the sinus rhythm. CONCLUSIONS: This study suggests that electrical cardioversion of atrial fibrillation after successful PBMV is favorable and recommendable treatment modality of chronic valvular atrial fibrillation with high conversion rate (88%) and good maintenance rate (63%).
Amiodarone ; Atrial Fibrillation* ; Bradycardia ; Echocardiography ; Echocardiography, Transesophageal ; Electric Countershock* ; Female ; Follow-Up Studies ; Humans ; Warfarin

BACKGROUND: Recently in Korea, the rate of addictive drug abuse is rapidly increasing in men on salary, housewives, and even in adolescents, who have been considered to be free from drugs, which presents a serious problem to the society. Especially, the habituation to gateway drug, such as cigarettes and alcohol, before 15 years old, would lead to the increased possibility of other drug abuse, including illicit drugs. Thereupon in this study, we intended toreview the effect of adolescents smoking an the drug abuse and deviated behaviors. METHODS: On September, 1997, randomly selected were 12 classes, an the basis of 2 classes per grade, from the two schools which was located each in Seoul and Buchean. And survey was dane on 610 students with non non-nominl, self-reported questionnaire. RESULTS: The rate of adolescent smoking was 28.1% in male students and had increasing tendency of "the higher the grades, the higher the smoking rate"(17.0% in the 1st gade, 31.5% in the 2nd grade, 35.9% in the 3rd grade). The smoking rate of female students was 12.3%. From the 2nd grade of middle school to the 2nd grade of high school was the critical period when the smoking habit was initiated in almost 90% of the students. The experiencing rates of drug abuse in studied subjects were as follows : drinking(79.0%), stimulants(4.8%), sedatives(4.1%), hypnotics(3.1%), glue sniffing(1.5%), butane gas(0.7%), marijuana/hemp(0.2%). They were higher in the smoking group than in the nansMoking group, showing statistical significances in most items except hypnotics and marijuana/hemp. Also simihr results were shown in deviated behaviors between the groups. CONCLUSIONS: With the concerted efforts of family, school, society and natian, we as family physicians should make efforts to delay and prevent adolescent's smoking, which is a gateway to drug abuse and deviated behaviors, and to increase people's recognition of health risks caused by smoking, and to provide proper program for adolescents to stop smoking.
Adhesives ; Adolescent ; Critical Period (Psychology) ; Female ; Humans ; Hypnotics and Sedatives ; Korea ; Male ; Physicians, Family ; Salaries and Fringe Benefits ; Seoul ; Smoke* ; Smoking* ; Street Drugs ; Substance-Related Disorders* ; Tobacco Products ; Surveys and Questionnaires

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant disorders in humans. NF1 is caused by mutations in the NF1 gene which consists of 57 exons and encodes a GTPase activating protein (GAP), neurofibromin. To date, more than 640 different NF1 mutations have been identified and registered in the Human Gene Mutation Database (HGMD). In order to assess the NF1 mutational spectrum in Korean NF1 patients, we screened 23 unrelated Korean NF1 patients for mutations in the coding region and splice sites of the NF1 gene. We have identified 21 distinct NF1 mutations in 22 patients. The mutations included 10 single base substitutions (3 missense and 7 nonsense), 10 splice site mutations, and 1 single base deletion. Eight mutations have been previously identified and thirteen mutations were novel. The mutations are evenly distributed across exon 3 through intron 47 of the NF1 gene and no mutational hot spots were found. This analysis revealed a wide spectrum of NF1 mutations in Korean patients. A genotype- phenotype correlation analysis suggests that there is no clear relationship between specific NF1 mutations and clinical features of the disease.
Adolescent ; Adult ; Child ; Child, Preschool ; DNA/chemistry/genetics ; DNA Mutational Analysis ; Genotype ; Humans ; Infant ; Korea ; Middle Aged ; *Mutation ; Neurofibromatosis 1/*genetics/pathology ; Neurofibromin 1/*genetics ; Phenotype ; Research Support, Non-U.S. Gov't

This study aims to ascertain the human saccadic visual tracking characteristics by measuring the eye movement to the double-step stimuli. Responses to simple step and double-step target motions were measured where the target mode and stimulus durations were randomized. To measure the eye movement the Photo-electric Eye Monitor was constructed based on limbus tracking. The results indicate that observers represented two kind of responses (A-or B-type) depending upon the stimulus duration. The percentage of occurrances increased as the stimulus duration increased from 50 to 200 msec. When the subject responded to both target motions, the reaction time of the second saccade was shorter than that of the first. The successive visual information is to change continuously the reaction time or cancel the initial saccade. Our results revealed that parallel data processing characteristics of the visual tracking systems and the saccadic decision-makings are influenced by the temporal relationships.
Eye Movements ; Humans* ; Reaction Time ; Saccades

The purpose of this review is to examine the ways in which eye position and eye movements are measured in order to justify the choice of method for the study concerning the eye movement control systems. The oculomotor control systems were reviewed previously as a viewpoint of measuring objects. Because of the different aspects of eye movement which have been considered, various techniques have been developed-each having its own characteristics of range, sensitivity, bandwidth, stability and ease of application. This study is directed at discussing the pros and cons inherent in a basic method of measurement and to indicate the interesting historical development of oculography as new technologies were employed. Various methods are summarized and photo-electronic method(Limbus tracking technique) was chosen which is most available for the future experimentation.
Eye Movements*