This study was performed to demonstrate the effect of linear or nonlinear contrast enhancement on subtraction images. Three different textures were radiograped on dental film. The first radiograph was taken without the presence of an object. the second, which showed trabucular bone, was taken of the molar area of a human. the third radiograph was taken of the coronal part of molars. Each film was digitized into a 1312 X 1024 pixel X 8 bit depth matrix by means of a Nikon 35 mm film scanner(LS-3510AF, Japan) with fixed gain and internal dark current correction to maintain constant illumination. The scanner was interfaced to a Macintosh LC III computer(Apple Computer, Charlotte, N.C.). This resulted in three pairs of images, including different textures-plain, bone and enamel. Digital regular, linearly and nonlinearly enhanced subtraction was performed. Computer software was used to simulate lesions in the shape of a 2D-Gaussian curve on each of a pair of images. The each subtraction images were presented in a random sequence to two groups of 10 observers(students and dentists). ROC analysis was used to compare observer performance. The following results were obtained; 1. All of LCE subtraction, equalized subtraction and regular subtraction images of plain texture were diagnosed the best by far. 2. The data revealed a siginificant LCE effect in both the student group and the expert group. 3. Clinical expertise was a helphul factor for the observers in this study.
Dental Enamel ; Humans ; Lighting ; Molar ; ROC Curve

PURPOSE: Occupational stress can have a negative effect on the worker such as physical, emotional, and psychological health. Although it is well reported that health service staff tend to have a high level of minor psychiatric disorder, only a few studies have been reported in Korea. Intern and Residency (residents) are very vulnerable periods of stress and other psychiatric disorders. In this study, we describe occupational stress of interns and residents and relationship between occupational stress and depression. METHODS: The participants of this study were interns and residents trained in a tertiary hospital in Korea. The occupational stress scale was used for measurement of occupational stress. In addition, the Korean version of the Beck depression scale was used to evaluate the prevalence of depression. Statistical analyses were performed using SPSS v. 18.0; p-value less than 0.05 was considered statistically significant. RESULTS: Female doctors showed higher occupational stress than male. Interns and chief residents demonstrated higher occupational stress than other grades. Astonishingly, most participants showed depressive mood. Compared with the general population, job demand and culture of the workplace are in the first upper quartile. It is indicated that compared with general populations, physicians have a higher workload and patience is required in order to cope with the harsh culture of the workplace. Depressive mood was evaluated with various factors and only occupational stress was statistically significant. CONCLUSION: Overwhelming occupational stress of residents could result in both medical and social problems. Therefore, recognition of occupational stress is essential and aggressive interventions are required.
Burnout, Professional ; Depression ; Female ; Health Services ; Humans ; Internship and Residency ; Korea* ; Male ; Prevalence ; Seoul* ; Social Problems ; Tertiary Care Centers*

The purpose of this study was to investigate whether a radiometric analysis of radicular cysts and periapical granulomas is useful in the differential diagnosis. In this experiment, twenty-nine periapical radiographs of the radicular cyst and those periapical granuloma were used. The periapical radiography was taken by intraoral paralleling device. The X-ray film was digitized and digitally filtered to reduce film-grain noise. We estimated density difference of the inner/outer area, roundness or circularity, bone profile or scan line of the margin and cumulative percentage frequency curve of radicular cyst & periapical granuloma. The obtained results were as follows ; 1. The differences in density between ROIs of inner and outer area of radicular cysts were smaller than those of periapical granulomas. 2. The equivalent circular diameter was over 6.3mm, there was significant difference between periapical cyst and periapical granuloma. 3. In differential diagnosis of radicular cyst and periapical granuloma using bone profile, sensitivity, spicificity and accuracy were considerably high(0.83, 0.86, 0.86) respectively. 4. Cumulative percentage frequency curve of the radicular cyst was closer to the pseudo-pixel value of 50 than average curve, whereas periapical granuloma was closer to that of 0. Hence we conclude that digital radiometric features might be useful in the differential diagnosis between radicular cyst and periapical granuloma.
Diagnosis, Differential ; Noise ; Periapical Granuloma* ; Radicular Cyst* ; Radiography ; X-Ray Film

Ten feet from 6 idiopathic congenltal clubfoot patients which had failed to respond to conservative mearsured were treated by aggreasive posteromedial release during infancy with generally good results. A modltication of Denis-Browne splint by splitting both aides and using dial lock to hold the foot still ln correeted position was found quite useful for post-operative maintenance.
Clubfoot ; Foot ; Humans ; Splints

BACKGROUND: The orthostatic hypotension in response to the assumption of an upright posture is regulated by activation of sympathetic nerves. Role of the vestibular system and neural pathway on orthostatic hypotension were investigated. METHODS: Changes of arterial blood pressure produced by head-up tilting, rotatory stimulation of the vestibular system, or electrical stimulation to the vestibular nerve, vestibular nuclei, and rostral ventrolateral medulla (RVLM) were measured in Sprague-Dawley rats. Also, field potentials were recorded in the vestibular nuclei and RVLM and c-Fos expression was evaluated in the brain stem in order to investigate the vestibulosympathetic pathways. RESULTS: The three phasic blood pressure responses were elicited by head-up tilting: initial fall, early recovery, and late sustained pressure at near control levels, the magnitude of the pressure fall was parallel with the degree of head-up tilting in normal rats. Return position from head-up tilting recovered control level of blood pressure after a brief rapid elevation. However, bilateral labyrinthectomy resulted in exaggerated initial falling and devoid of early recovery phase during postural change. Sinusoidal rotation about off-vertical axis of the vestibular system elicited more elevation of blood pressure than rotation about earth vertical axis. Electrical stimulation of the vestibular nerve, vestibular nucleus, and RVLM produced elevation of blood pressure, which was the most prominent by stimulation of RVLM. Field potentials composed of P, N1, N2 waves in the vestibular nuclei were recorded by stimulation of the vestibular nerve, while weak potentials in RVLM were recorded by stimulation of the vestibular nuclei. An electrical stimulation of the vestibular nuclei expressed c-Fos immunoreactive cells in RVLM. CONCLUSION: These results suggest that the otolith organ of the vestibular system plays a major role in control of orthostatic hypotension, and the pathway of vestibulosympathetic reflex in control of blood pressure involves the vestibular nuclei, RVLM, intermed-iolateral nuclei of the thoracic spinal cord.
Animals ; Arterial Pressure ; Axis, Cervical Vertebra ; Blood Pressure ; Brain Stem ; Electric Stimulation ; Hypotension, Orthostatic* ; Neural Pathways ; Otolithic Membrane ; Posture ; Rats* ; Rats, Sprague-Dawley ; Reflex* ; Spinal Cord ; Vestibular Nerve ; Vestibular Nuclei

This is the report of our clinical experience of 1365 cases of aneethesia for eelectroconvu lsive therapy at the Department of Anesthsiology, Maryknoll Hospital, during the period of March, 1989 to February, 1986. To prevent complications, suck as compressed fracture of the spine, and to improve doctor-patient relationship, softening electroconvulsive therapy is the preferred treatment for indicated cases.The results were as follows: 1) Diagnostic distribution of the patients treated by E.C,T. were schizophrenia 74.3%, affective disorder 15.0%, other psychosis 10.7$. 2) Average number of treatments given to a patient were average 6.7 times, for the entire group,7.8times for schizophrenia, 8.2 times for the patients with mania,5.5 times for the Patients with major depression, 5.6 times for the patients with the other psychosises. 3) Medication required was sufficient with half the dosage of uaual surgical procedu res ; ie, atropine sulfate 0.008 mg/kg, thiopental sodium 2.5 mg/kg, and succinylcholine 0.5 mg /kg. 4) Duration of apnea averaged 2 minutes 30 seconds, awakening averaged 10 minutes, and average duration per treatment was 15 min. 5) Few patients complained of discomfort or phobia, and less personnel and less effort were required. Complications and side effecta due to anesthesia were minimal.
Anesthesia ; Anesthesia, General* ; Apnea ; Atropine ; Depression ; Electroconvulsive Therapy* ; Humans ; Mood Disorders ; Phobic Disorders ; Psychotic Disorders ; Schizophrenia ; Spine ; Succinylcholine ; Thiopental

Myasthenia Gravis is a neuromuscular disorder manifested by increasing weakness and fatigability of voluntary muscles with exercise, and partial or complete restoration of function following rest or the administration of anticholinesterase drugs. The anesthesiologists may be called upon to assist in the diagnosis of myasthenis, in treating the patient by artificial ventilation during acute exacerbations, to anesthetise the patient for thymectomy or other surgery. Therefore, the anesthesiologists must be familiar with the diagnosis and treatment of myasthnia gravis to carry on the appropriate therapy. Two cases of anesthesia for thymectomy in myasthenia gravis without using muscle relaxants was experienced, and no respiratory problems were encountered postoperatively.
Anesthesia* ; Cholinesterase Inhibitors ; Diagnosis ; Humans ; Muscle, Skeletal ; Myasthenia Gravis* ; Thymectomy* ; Ventilation

BACKGROUND AND OBJECTIVES: In this current era of using drug-eluting stents (DES), studies that demonstrate the feasibility and clinical outcome of percutaneous coronary intervention (PCI) using DES in a subset of extremely aged patients are lacking. We investigated the clinical characteristics, therapeutic and clinical outcomes of patients older than 80 years that had been implanted with DES during a PCI. SUBJECTS AND METHODS: Fifty-three "octogenarian" patients (> or =80-years-old) and 1036 "non-octogenarian" patients (<80-years-old) that had been implanted with DES at Chonbuk National University Hospital since March 2003 were enrolled in the study. Medical records of the patients in the two groups were retrospectively reviewed. RESULTS: The mean ages of the patients in the two groups were 83+/-2 years and 62+/-11 years, respectively, and the mean follow-up period was 15.8+/-10.9 months and 21.1+/-10.8 months, respectively. The octogenarian group showed an increased prevalence of female patients (58.5% vs. 35.1%, p=0.001), acute coronary syndrome (98.1% vs. 78.6%, p=0.001), ST-segment elevation myocardial infarction (41.5% vs. 28.3%, p=0.003), shock (17.0% vs. 6.6%, p=0.004), heart failure (22.6% vs. 9.3%, p=0.002) and a higher in-hospital major adverse cardiac event (MACE) rate (13.2% vs. 3.5%, p=0.004) than the non-octogenarian patients. Angiographic restenosis and target lesion revascularization rates were not different in both groups, but overall MACE (18.9% vs. 9.9%, p=0.035) and all-cause mortality (p<0.001) rates were significantly higher in the octogenarian group of patients. CONCLUSION: Although angiographic follow-up results were comparable in octogenarians and non-octogenarians, the occurrence of short- and long-term MACE was significantly higher in the very elderly group owing to a substantial subset of high-risk patients.
Acute Coronary Syndrome ; Aged ; Aged, 80 and over* ; Coronary Disease ; Drug-Eluting Stents* ; Female ; Follow-Up Studies ; Heart Failure ; Humans ; Jeollabuk-do ; Medical Records ; Mortality ; Myocardial Infarction ; Percutaneous Coronary Intervention* ; Prevalence ; Retrospective Studies ; Shock ; Stents

Tryptophan metabolites regulate a variety of physiological processes, and their downstream metabolites enter the kynurenine pathway. Age-related changes of metabolites and activities of associated enzymes in this pathway are suggestable and would be potential intervention targets. Blood levels of serum tryptophan metabolites in C57BL/6 mice of different ages, ranging from 6 weeks to 10 months, were assessed using high-performance liquid chromatography, and the enzyme activities for each metabolic step were estimated using the ratio of appropriate metabolite levels. Mice were subjected to voluntary chronic aerobic exercise or high-fat diet to assess their ability to rescue age-related alterations in the kynurenine pathway. The ratio of serum kynurenic acid (KYNA) to 3-hydroxylkynurenine (3-HK) decreased with advancing age. Voluntary chronic aerobic exercise and high-fat diet rescued the decreased KYNA/3-HK ratio in the 6-month-old and 8-month-old mice groups. Tryptophan metabolites and their associated enzyme activities were significantly altered during aging, and the KYNA/3-HK ratio was a meaningful indicator of aging. Exercise and high-fat diet could potentially recover the reduction of the KYNA/3-HK ratio in the elderly.
Aged ; Aging ; Animals ; Chromatography, Liquid ; Diet, High-Fat* ; Exercise* ; Humans ; Infant ; Kynurenic Acid ; Kynurenine* ; Mice ; Physiological Processes ; Tryptophan*

Myasthenia Gravis is a chronic disorder of neuromuscular transmission characterized by weakness, fatigue of voluntary muscles, especially exacerbations and remissions, a rare disease in Korea. Special considerations are required in the anesthetic management of the myasthenic patients undergoing surgery under general anesthesia and in the postoperative respiratory management by anesthesi olgists. Authors report 8 cases of anesthesia, using N20-02-Enflurane without using nondepolarizing and depolarizing muscle relaxants for thymectomy, experienced during the year 1986~1990.
Anesthesia ; Anesthesia, General ; Fatigue ; Humans ; Korea ; Muscle, Skeletal ; Myasthenia Gravis ; Neuromuscular Depolarizing Agents ; Rare Diseases ; Thymectomy*