Quality Control of Radiation Dosimetry Service / 의학물리

We have developed standards based on international criterions for the quality control of dose tested by the measurement institutions of individual exposure doses through improving the reliability of data on the exposure dose of individuals working in radioactive environment and securing the accuracy and reliability of individual dose measurements. Laws related to radiation dose applied to domestic institutions refer to ANSI N13.11?1993, but currently , in U.S. and some other countries the measurement of radiation doses is based on ANSI N13.11?2001 that reduced test categories and tightened the standards. We made efforts to simplify the standards and to reduce the number of dosimeters required in experiment, and avoided preventing or hindering the use of future technologies not approved under the current law such as glass dosimeter and optical stimulation dosimeter. The Quality Management Manual of Radiation Dosimetry Service, Assessment Manual of Radiation Dosimetry Service Accreditation Program, and the Personnel Dosimetry Performance-Criteria for Testing are documents applicable in supervising laboratories.

Neurological Aspects of the Patient with Spasmodic Dysphonia

Spasmodic dysphonia Is a form of focal dystonia affecting laryngeal muscles. There have been a few reports on the neurological aspects of the patient with spasmodic dysphonia. No data on the clinical courses and possible causative neurological diseases have been reported. We analysed 44 patients with spasmodic dysphonia, using a check-list of clinical symptoms and laboratory tests in a prospective manner, Forty one patients had adductor type of spasmodic dysphonia and three patients had abductor type. Five different clinical courses have been identified ; about half of the patients showed relentless progress of symptoms for many years(range 1-26 years ; mean 9.8 years). Magnetic resonance imaging study of the brain showed abnormalities in three patients(2 had a focal lesion in the basal ganglia and 1 had multiple cerebral infarctions). One showed acanthocytosis on electron-microscopic examination of the peripheral blood smear. Navicular tremor, low facial dyskinesla, and development of other involuntary movement at the time of onset of spasmodic dysphonia may be clues suggestive of symptomatic form of spasmodic dysphonia.

The Value of External Anal Sphincter Motor Unit Potential Analysis in Differentiating Idiopathic Parkinson's Disease and Multiple System Atrophy

Multiple system atrophy (MSA) is an idiopathic neuro-degenerative disorder involving many neuronal structures including substantia nigra, putamen, cerebellum, pontine nuclei, olives, intermediolateral cell column of the spinal cord. Anterior horn cells innervating external urethral and external anal sphincter muscles in the sacral cord, so called Onuf's nucleus, are also affected. Neuronal loss of the Onuf's nucleus may cause denervation and reinnervation in the external urethral and the external anal sphincter muscles. As a result, in the patients with MSA electromyographic study of the external urethral and the external anal sphincter muscles may show prolonged duration of motor unit potentials (MUPs). Such abnormal MUPs of the external urethral sphincter muscles has been known to be a useful indicator distinguishing patients with MSA from those with idiopathic Parkinson's disease (IPD) in which minimal or no abnormal MUPs can be found. However, the results of external anal sphincter MUPs analysis has not been reported yet. In the patients with IPD and probable MSA, we measured the duration, the number of phases and the proportion of pathological MUPs from the external anal sphincter muscles. Cut off value of more than 60% of abnormal MUPs could differentiate patients with MSA and IPD with sensitivity of 70.3% and specificity of 90.9%. External anal sphincter MUP analysis seems to be a helpful laboratory method differentiating patients with MSA and IPD.

Urinary Problems in Idiopathic Parkinson's Disease and Multiple System Atrophy

Previous studies showed that 37-71% of the patients with idiopathic Parkinson's disease (IPD) or parkinsonism of other causes had urinary problems. There are several possible reasons for such wide range of frequency of urinary problems in Parkinson's disease or parkinsonism; (1) They used different questionnaires on the urinary problems; (2) they did not try to differentiate the patients with idiopathic Parkinson's disease and those with multiple system atrophy (MSA), in which condition severe urinary problems occur frequently early in the clinical course or even before the onset of parkinsonian symptoms. However, exact nature of urinary problems in MSA and IPD has never been compared. Using Boyarsky score, we compared the frequency and severity of urinary symptoms between 32 patients with IPD and 28 patients with probable MSA. All except one with MSA (96.5%) had urinary symptoms. Although 24 of the 32 with IPD (75%) also had urinary problems, the severity was milder than those with MSA. In 8 with MSA, urinary symptoms preceeded the onset of parkinsonian symptoms. No one with IPD developed urinary symptoms before the onset of parkinsonian symptoms. Seven out of the 28 patients with MSA voided more than 8 times during the day, 10 woke up more than 2 times to void during sleep, 20 wet their clothes more than 2 times per a day. However no one with IPD had such severe urinary problems. Careful history taking about the urinary had such severe urinary problems. Careful history taking and MSA problems seems to be a helpful way in differentiating IPD and MSA.

Neuroacanthocytosis: 2 Cases of Familial Choreoacanthocytosis

Neuroacanthocytosis is a rare dosorder characterized by various neurological manifestations and the presence of abnormal red blood cells called acanthocytes which have a disturbed morphology showing spiky, knobby end projections. Acanthocytosis associated with neurological involvements includes 3 major syndromes ; Bassen-Korzweig syndrome, choreoacanthocytosis (or Levine-Critchley syndrome), and Mcleod syndrome. Here, we report two cases of familial choreoacanthocytosis. A 40 years old man presented with orofacial dyskinesia, involuntary vocalization, dysarthria, dysphagia, generalized choreic movements, hyporef lexia, and amyotrophy of the bilarteral anterior tibilais muscles. Serum creatine phosphokinase was increased. Scanning electronmicroscopic examination of the fresh peripheral blood smear film showed acanthocytes, corresponding to about 6% of all red blood cells. His one of two daughter had high arched foot, bradykinesia, and hypoactive deep tendon reflexes. A 70 years old woman showed head and hand tremor, bilateral eye brow choreic movements, torticollis and bradykinesia. Her mother and two younger sisters had head termor. Serum creatine phosphokinase level was normal. Scanning electronmicroscopic examination of the fresh peripheral blood smear showed acnthocytes, corresponding to 9% of the examined red blood cells.

Neurophysiological Studies in a Patient with Hyperekplexia

The results of neurophysiological studies in a 20 year-old man who had pathological jumps and falls following unexpected auditory stimuli is presented. He also had action induced hemidystonia and polymyoclonus involving fingers of the both hands. Somatosensory evoked potential study showed no giant cortical wave and jerk-locked back averaging electroencephalogram showed no jerk ,related cortical event. Polymyographic study after auditory stimuli showed electromyographic (EMG) bursts recruitment pattern consistent with hyprekplexia ai)d reticular reflex myocloniis. EMG bursts spread rostrally and caudally from the sternocleidomastoid muscle via a slowly conducting neuronal pathways. These findings are compatible. With hyperekplexia. Pathologically increased gain of the brainstem reticular formation seems to cause hyperekplexia.

Sleep Related Periodic Leg Movements

We describe 7 patients with sleep related periodic leg movements(SRPLM) associated with variable neurological diseases, including focal thoracic cord lesions(4 cases), idiopathic Parkinson's diseased case), recurrent aseptic meningitis(1 case), and subacute sensory polyneuropathy(l case). Four patients with SRPLM associated with thoracic cord lesions also had paraparesis, suggesting involvement of pyramidal tract in the genesis of SRPLM. All the other three patients had dysesthesia, and at least two of them had restless legs syndrome. SRPLM of a patient with a thoracic schwannoma disappeared completely after surgical removal of tumor. One patient with intramedullary thoracic cord lesion and one asociated with Parkinson's disease showed marked improvement of SRPLM after levodopa treatment. Damage to the pyramidal tract or abnormal sensory inputs seem to activate lumbosacral generator selectively. Such neuronal systems are suspected to be modulated by. The dopaminergic neuronal system and the neuronal structures related to sleep.

Clinical Syndrome of Corticobasal Degeneration

Clinical features of corticobasal degeneration (CBD) can be characterized by an asymmetric akinetic-rigid syndrome with variable combinations of other deficits (corticospinal tract signs, supranuclear gaze palsy, cerebellar ataxia, cortical sensory loss, alien limb behavior, dystonia and myoclonus). Such unique combination of clinical features of CBD have lead to the general agreement that clinical diagnosis of CBD is reliable. We describe 6 patients presenting with clinical features compatible with CBD. Three had characteristic clinical features of CBD; one showed clinical features compatible with progressive supranuclear palsy, but also had apraxia and cortical sensory disturbances; one had an early CBD. The remaining one had clinical features compatible with CBD, but brain magnetic resonance imaging study showed multiple small lesions involving periventricular white matter and basal ganglia bilaterally.

An Experimental Study of Tricalcium Phosphate (TCP) as a Bone Graft Substitutes of Bone Defects in Canine Femur / 대한정형외과학회잡지

The search for useful bone graft substitutes historically has focused on biologic alternatives. TCP has a 36% porosity and variable pores ranging from 100 to 300µm in diameter. They are biocompatible, easy fabricated into any size or shape, and offer a chemical environment and surface conductive to new bone formation. The porous scaffolding of the TCP permits rapid bone ingrowth. Gradual replacement of the ceramic with mature remodelling bone is noted as bioresorption of the TCP proceeds. The author investigated with TCP to evaluate the effect on the healing process of canine femoral bone defect as a bone graft substitutes. Five mongrel dogs(12Kg) were used in this study. Two holes(3.5mm) were created artificially with drill on the lateral surface of both right and left distal femora metaphyseal area in each dog under general anesthesia with nembutal. After creating artificial bone defects, 1 bone defect hole was filled with biodegradable TCP ceramic and adjacent other one was used as a control site wthout filling any implant material. The interval of each observation was 4, 6, 8, 10, 12 weeks after implantation and examined by means of radiology, histology with light and electron microscope. The results obtained were as follows; 1. Lamellar bone was formed around TCP 8 weeks after implantation. 2. In peripheral areas of TCP, collagen fibers, cytoplasm of osteoclasts & osteoblasts present in micropores of TCP. Osteocytes appeared around TCP with time. 3. In central areas of TCP, amorphous matrix was deposited in micropores in the early phase(4 weeks), but later collagen fibers & cytoplasmic processes appeared. 4. Osteoclasts were collected around TCP granules. Size of TCP granules in the periphery was gradually decreased. 5. Foreign body reaction within tissue was not shown during a whole experimental period. 6. Radiologically, opacity of implanted TCP was gradually decreased, and spillage on soft tissue of TCP was resorbed rapidly.

The Effects of Air Exposure on Articular Cartilage ; Degeneration & Regeneration / 대한정형외과학회잡지

Orthopedic procedures expose articular cartilage to operating room air for varying periods of time as long as two hours. Articular cartilage is dense white, glossy and smooth, and is composed of chondrocytes, collagen, and a hyaline matrix made up of proteoglycan molecules. Articular cartilage is a specialized tissue containing 75 to 85% water. Most of the water is trapped in a gel of matrix collagen and proteoglycan and is freely exchangeable with the synovial fluid and blood. Only about 6% of cartilage water is tightly bound. Theoretically, since cartilage gel is hyperhydrated, the water content is important in maintaining cartilage resiliency and lubrication of the articular surfaee. If a pathologic state is associated with reduction on water content, these properties may be altered, leading to impaired joint function. We reproduced the O.R. situation by exposing one knee of 24 mature New-Zealand white rabbits to smbient air (20–22℃) for 30 minutes to 2 hours, the opposite knee serving as a control. Following exposure, the joints were closed snd the animal resumed cage activity for 1 day prior to sacrifice, at that time cartilage was removed from both exposed and control joints and prepared for gross, light microscopy and electron microscopy. We observed cartilages which were sacrificed at 1 week after operation, 2 weeks after and 4 weeks after for varying periods of exposing time in same method. The results were as follow ; 1. A distinct color change was seen in the exposed cartilage in groups which were sacrificed postoperative at 1 day ; However minimal change was detected in each group sacrificed at 1 week & 2 weeks later, and no change was seen in each group sacrificed postoperative at 4 weeks. 2. Exposure to room air for 30 minutes produced chondrocyte necrosis in the superficial zone of rabbit articular cartilage. Exposure for 1 hour or longer produced chondrocyte necrosis up to radial zone. 3. Chondrocyte necrosis was not seen in each group for varying periods:0f air exposure microscopically, which sacrificed postoperative at 1 week. 4. Proteoglycan content was minimal at 1 week postoperatively in each group ; However proteoglycan content increased progressively with time. 5. Change in cellularity were consistent with cartilage damage. Seemingly, exposing articular cartilage to air for 2 hours caused reversible cartilage damage.

Symptomatic Parkinsonism and Differential Diagnosis

No abstract available.

Clinical Study of Patients with Ossification of Posterior Longitudinal Ligament

This clinical study was performed to evaluate the effect of narrowing of spinal canal and calcified mass size on clinical manifestation in patients with ossification of posterior longitudinal ligament. Among cervical myelopathy patients with ossification of posterior longitudinal ligament in plain film and C-spine CT at Seoul National University Hospital From Mar. 1984 to Feb. 1986. All patients were male, ages ranging from 37 to 67 years. Ossified mass size and spinal canal AP diameter were measured in CT film. Patients were grouped by their functional status as Group I and Group II. Ossified mass size was markedly larger in disabled patients but spinal canal AP diameter excluding ossified mass was not so different. Actual AP diameter of spinal canal also markedly decreased in disabled patients. It seemed, therefore, that calcified mass size and actual spinal canal AP diameter had more significant effect on symptom and disability.

Effect of Steroid Treatment in Myasthenia Gravis

Twenty-one myasthenic patients were treated with high-dose daily prednisone regimen at Seoul National University Hospital from May 1983 to January 1985. Observations in relation to dosage, drug schedule, clinical responses, and sideeffects led us to following conclusions concerning the management of myasthenia gravis with steroid. In addition, factors influencing the result were considered. 1) Among 21 patients, twenty(95%) showed clinical improvement of variable degrees. 2) Significant improvement could be expected especially in male patients, in older patients, and in those with duration of myasthenia gravis less than 6 months prior to treatment. Performance of thymectomy or thymothymectomy, thymic pathology, and clinical grade at the time of therapy were not considered to affect the outcome. 3) Ten cases (48%) suffered from initial exacerbations, most of which occurred within the first four days of treatment. Steroid-induced crises developed in four cases with preexisting brittle or severe generalized myasthenia. 4) Period taken to show the initial response and the maximum improvement varied widely but majority of them occurred within 15 days and 70 days respectively. 5) Off-day weakness during the alternate-day schedule required special cautions and, if persitent, immediate return to daily schedule was desirable. 6) Thymectomy prior to steroid treatment was not always necessary but, when both regimens were scheduled together, preparation therapy with steroid thought to be more favorable. 7) Aside from initial exacerbations side-effects during the treatment were not remarkable, all of which disappeared with reduction of dosage.

Computed Tomography of Japanese Encephalitis with Clinical Correlation

The computed tomographic (CT) and clinical findings in 9 patients with serologically confirmed Japanese encephalitis were reviewed. In 6 patients with prominent pyramidal and extrapyramidal symptoms and signs, the main CT finding was low density areas in the thalamus, internal capsule, basal ganglia, and midbrain. Low density areas were compatible with the anatomical distribution of pathologic lesions in Japanese encephalitis. Diffuse low density in the periventricular white matter was evident in 5 of 6 cases, with ventricular compression in 2 cases, between the 1st and 7th day of illness. There was enlargement of the third and lateral ventricles and cortical sulci dilatation in 3 cases on or after the 21st day of illness. In once CT scan obtained on the 10th day of illness, diffuse low density in the periventricular white matter was observed with enlargement of lateral ventricles and cortical sulci dilatation. Gyral enhancement was noted in 3 of 4 cases within 4 days after the onset of symptoms. There was a limited correlation between the clinical and CT findings.