• Progress in Medical Physics
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• v.15 no.1
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• pp.30-38
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• 2004

Purpose: To develop a whole body frame for the purpose of reducing patient motion and minimizing setup error for extra-cranial stereotactic radiotherapy, and to evaluate the repositioning setup error of a patient in the frame. Materials and Methods: The developed whole body frame is composed of a base plate, immobilizer, vacuum cushion, ruler and belts. The dimension of the base plate is 130 cm in length, 50 cm in width and 1 cm in thickness. The material used in the base plate of the frame was bakelite and the immobilizer was made of acetal. In addition, Radiopaque angio-catheter wires were engraved on the base plate for a coordinate system to determine the target localization. The measurement for radiation transmission and target localization is peformed in order to test the utilization of the frame. Also, a Matlab program analyzed the patients setup error by using the patient's setup images obtained from a CCTV camera and digital record recorder (DVR). Results: A frame that is useful for CT simulation and radiation treatment was fabricated. The frame structure was designed to minimize collisions from the changes in the rotation angle of the gantry and to maximize the transmission rate of the Incident radiation at the lateral or posterior oblique direction. The lightening belts may be used for the further reduction of the patient motion, and the belts can be adjusted so that they are not in the way of beam direction. The radiation transmission rates of this frame were measured as 95% and 96% at 10 and 21 MV, respectively. The position of a test target on the skin of a volunteer is accurately determined by CT simulation using the coordinate system in the frame. The estimated setup errors by Matlab program are shown 3.69$\pm$1.60, 2.14$\pm$0.78 mm at the lateral and central chest, and 7.11 $\pm$2.10, 6.54$\pm$2.22 mm at lateral and central abdomen, respectively. The setup error due to the lateral motion of breast is shown as 6.33$\pm$ 1.55 mm. Conclusion: The development and test of a whole body frame has proven very useful and practical in the radiosurgery for extra-cranial cancers. It may be used in determining target localization, and it can be used as a patient immobilization tool. More experimental data should be obtained in order to improve and confirm the results of the patient setup error.

• Progress in Medical Physics
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• v.8 no.2
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• pp.3-17
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• 1997

Because a wedged beam consists of attenuated primary photons and scattered radiations from wedge, the spectrum of the wedged beam does not coincide with that of an open beam with same geometry. The aims of current report are to get exact information about whether effects of 15-60$^{\circ}$ wedge for 4 -10 MV photon beams should be considered for dose calculation or not, and to suggest a reference condition for measurement of wedge transmission factor. Percent depth dose of both open and wedged fields with angles of 15, 30, 45, 60$^{\circ}$ for beams of 4 MV(Clinac 4/100, Varian), two 6 MV(Clinac 6/100 and Clinac 2100C, Varian), 10 MV(Clinac 2100C, Varian) X-rays were measured to 30cm deep in water using ionization chambers. Hardening factors of photon beams were calculated with measured PDDs. Both field size factors and transmission factors of wedge filters were measured at d$_{max}$ in water. Beam hardening factors of wedged fields of 4 and 6 MV X-ray were larger than 1 for all wedge angles, field sizes and depths deeper than d$_{max}$ Beam hardening factors for wedge angles 15, 30, 45, 60$^{\circ}$ for 10$\times$10cm were respectively 1.010, 1.014, 1.023 and 1.034 for 4MV X-ray, 1.005, 1.008, 1.019, and 1.024 for 6MV X-ray of Clinac 6/100, 1.011, 1.021, 1.032, 1.036 for 6MV X-ray of Clinac 2100C, and 1.008, 1.012, 1.012 and 1.012 for 10MV X-ray. Beam hardening factors of 10MV X-ray were 1 within 1.2％ difference for all wedge angles, depths and field sizes. It was made clear that for 6MV X-rays, the beam hardening factor depends on treatment machine. The relationship of the factor and depth was linear. Field size factor at d$_{max}$ was independent of wedge angle except for the field of 15$\times$15cm. and maximum difference of the field size factors for the field size was 1.4％ for 4MV X-ray. When the wedge factor is determined, dependence of the factor on field size is negligible at d$_{max}$ but should be considered at deeper depth. Calculating dose distribution or MU, the beam hardening factor should be applied for 4~6MV X-ray beams, but might not be considered for 10MV beam. When wedge transmission factor was determined at d$_{max}$ or in air, field size factors for open field are also applicable to wedged fields, but otherwise, field size factor for each wedge or wedge factor depending on field size should be applied.

• Progress in Medical Physics
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• v.15 no.1
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• pp.1-8
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• 2004

Patient dose verification is one of the most Important responsibilities of the physician in the treatment delivery of radiation therapy. For the task, it is necessary to use an accurate dosimeter that can verify the patient dose profile, and it is also necessary to determine the physical characteristics of beams used in intensity modulated radiation therapy (IMRT) The Beam Intensity Scanner (BInS) System is presented for the dosimetric verification of the two dimensional photon beam. The BInS has a scintillator, made of phosphor Terbium-doped Gadolinium Oxysulphide (Gd$_2$O$_2$S:Tb), to produce fluorescence from the irradiation of photon and electron beams. These fluoroscopic signals are collected and digitized by a digital video camera (DVC) and then processed by custom made software to express the relative dose profile in a 3 dimensional (3D) plot. As an application of the BInS, measurements related to IWRT are made and presented in this work. Using a static multileaf collimator (SMLC) technique, the intensity modulated beam (IMB) is delivered via a sequence of static portals made by controlled leaves. Thus, when static subfields are generated by a sequence of abutting portals, the penumbras and scattered photons of the delivered beams overlap in abutting field regions and this results in the creation of “hot spots”. Using the BInS, inter-step “hot spots” inherent in SMLC are measured and an empirical method to remove them is proposed. Another major MLC technique in IMRT, the dynamic multileaf collimator (DMLC) technique, has different characteristics from SMLC due to a different leaf operation mechanism during the irradiation of photon and electron beams. By using the BInS, the actual delivered doses by SMLC and DMLC techniques are measured and compared. Even if the planned dose to a target volume is equal in our experimental setting, the actual delivered dose by DMLC technique is measured to be larger by 14.8% than that by SMLC, and this is due to scattered photons and contaminant electrons at d$_{max}$.

• Clinical and Experimental Pediatrics
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• v.49 no.8
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• pp.864-869
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• 2006

Purpose : We evaluated the immunogenicity and safety of eIPV(Imovax $Polio^{(R)}$) in a group of healthy Korean infants on a three-dose primary vaccination. Methods : Eighty one healthy infants aged 8-10 weeks were enrolled, and 79(male 42, female 37) completed the study. Three doses of eIPV were injected intramuscularly at 2, 4 and 6 months of age as of primary vaccination. Most subjects received concomitant vaccines such as DTaP and/or Hib at 2, 4, and 6 months of age. Immediate reactions were monitored for 30 minutes after each injection. Local and systemic events were recorded for 72 hours following each immunization by parents/guardians. Poliovirus specific neutralizing antibodies were measured using enzyme immuno-assay (EIA) at prior to and 1 month after the third dose. An antibody titer of 1:8 or higher was considered seroprotective. Geometric mean titers(GMTs) to each poliovirus type antigen were also measured. Results : One month after the third dose of eIPV, all infants(100 percent) were seroprotective. The geometric mean titers(GMTs) were 1,532(95 percent CI : 1,312-1,788) in type 1 and 835(95 percent CI : 684-1,018) in type 2 and 846(95 percent CI : 692-1,035) in type 3. Overall, local reactions were observed in 10 percent of infants and systemic reactions in 26.2 percent of infants. All reactions were observed within 3 days after vaccination and resolved without treatment. Conclusion : eIPV(Imovax $Polio^{(R)}$) is a well-tolerated and highly immunogenic vaccine. It can be administered either alone or simultaneously with other routine vaccines to Korean infants.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.228-236
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• 1999

Background: Thyrotoxic periodic paralysis is an uncommon illness characterized by intermittent flaccid paralysis of skeletal muscle, usually accompanied by hypokalemia, in patient with hyperthyroidism. However, the pathophysiology of thyrotoxic periodic paralysis remains largely unexplained and controversial. This report describes the clinical and biochemical findings in 19 patients with thyrotoxic periodic paralysis who were examined at the Yeungnam University Medical Center(YUMC) during the past decade. Methods: The medical records of 997 YUMC patients, seen between 1986 and 1996, with diagnosis of hyperthyroidism were reviewed. Nineteen patients out of 997 hyperthyroidism patients were diagnosed, and examined by history, physical examination, serum electrolyte value, and thyroid function test during paralysis. On the basis of these results, comparisons were made on age, sex, precipitating factors, timing, affected limbs, prognosis, serum potassium and serum phosphate and thyroid hormone levels. Results: The prevalence of periodic paralysis in hyperthyroidism was 1.9 percent and the male to female prevalence ratio was 30:1 and in all patients, the development of perodic paralysis was correlated with hyperfunctional state of the thyroid gland. Eleven cases of periodic paralysis were associated with hypokalemia and their thyroid hormone levels were significantly more increased than those of the patients without hypokalemia. Interestingly, our study shows the recurrence of paralysis after treatment. Conclusion: Although the precise pathophysiology of the disease is as yet undefined and controversial, it occurs primarily in Asians with an overwhelming male preponderance and prevalence of 2 percent in hyperthyroidism. The interactive roles of thyroid hormone, Na-K pump, and genetically inherited defect in the cellular membrane potential of the skeletal muscle can be speculated. Further investigation will be needed to firmly establish the mechanism of thyrotoxic periodic paralysis.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.91-97
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• 2007

To evaluate the physiological status of laying flocks, the blood chemistry values were measured and analyzed in various ages under different feeding conditions. Total 671 birds from 48 Hyline brown hens flocks from 13 different poultry farms were bled at the ages of day(s) 1, 11, 21, 50, 80, 120, 180, 240, 300, 400, and 500. The 17 blood chemistries including glucose, lipids, proteins, enzymes, electrolytes and metabolic by-products were measured with an autoanalyzer. Blood glucose showed the highest at the hatching day not relate with the dietary carbohydrates and energy, but tended to decrease during the rest of growth stage in hens. Total blood protein, albumin and globulin increased depending on the ages even though dietary protein was decreased. Blood lipid was greatly changed at different growth stages. Cholesterol was the highest at hatching period and maintained consistently until the 120 days of age. It was increased in birds after 180 days of age. HDL was also highest in hatchery, but decreased greatly after 180 days of age. However, TG was the lowest at one day old, but was increased up to 10 times after 180 days of age compared to that of one day old. The enzyme activities were different. AST, ALT, and GGT showed comparatively contained consistently, whereas amylase was slowly decreased. Blood P, Na, K and Cl showed consistency, but Ca content was increased upto two times of the one day of age. The results from this study showed that the blood chemistry values were affected by the general metabolic status of the host with ages not by feeding conditions. Further, the standard data of age-dependent blood chemistry values in the laying flocks were obtained, which can be utilized for early detection of the changes in the physiological status occurred by the infectious or metabolic diseases. The results of these analyses seemed to be useful to increase the productivity of laying flocks through rapid and proper veterinary medical treatments.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.110-115
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• 2008

Purpose: Intussusceptions are one of the most common causes of intestinal obstruction in infants and young children. Although it is easily treated by non-operative reduction using barium, water or air, this treatment is very stressful for young patients and may cause bowel perforation, peritonitis and shock. In this study, we identified the risk factors associated with the failure of non-operative reduction, to identify a group of children that would benefit from the procedure and those who would not. Methods: We reviewed the medical records of patients with intussusception who were treated at the Korea University Medical Center Ansan hospital from March 1998 to July 2006. Three hundred fourteen children with intussusception were identified. Among them, non-operative reductions were performed in three hundred. Clinical and radiological variables were compared according to the failure or success of the non-operative reduction. Results: Non-operative reductions were successful in 243 (81%) and failed in 57 (19%). The group that had failed procedures had a younger age (12.3${\pm}$17.2 months vs. 18.0${\pm}$15.8 months, p=0.03), longer symptom duration before reduction (33.6${\pm}$29.0 hr vs. 21.5${\pm}$20.3 hr, p<0.01), more vomiting and lethargy (p<0.01), but less abdominal pain and irritability (p<0.01), compared with the group that had a successful procedure. Logistic regression analysis showed that the factors associated with the failure of non-operative reductions were a younger age, less than 6 months of age (odds ratio: 2.5, 95% confidence interval: 1.2~5.2, p=0.01), duration of symptoms, longer than 24 hrs before reduction (odds ratio: 2.1, 95% confidence interval: 1.2~4.2, p=0.03), bloody stool (odds ratio: 4.8, 95% confidence interval: 1.9~12.2, p<0.01), lethargy (odds ratio: 3.4, 95% confidence interval: 1.1~10.4, p=0.04), and abdominal pain or irritability (odds ratio: 0.2, 95% confidence interval: 0.1~0.4, p<0.01). Conclusion: For children with intussusception, an age younger than 6 months, and duration of symptoms more than 24 hrs before reduction, as well as the presence of bloody stools, lethargy and abdominal pain or irritability were variables associated with failure of a non-operative reduction. Knowledge of these variables should be considered in making clinical decisions for therapeutic interventions.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.186-192
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• 2002

Purpose : Measurement of transmission dose is useful for in vivo dosimetry. In this study, previous algorithm for estimation of transmission dose was modified for use in cases with tissue deficit. Materials and Methods : The beam data was measured with flat solid phantom in various conditions of tissue deficit. New algorithm for correction of transmission dose for tissue deficit was developed by physical reasoning. The algorithm was tested in experimental settings with irregular contours mimicking breast cancer patients using multiple sheets of solid phantoms. Results : The correction algorithm for tissue deficit could accurately reflect the effect of tissue deficit with errors within ${\pm}1.0\%$ in most situations and within ${\pm}3.0\%$ in experimental settings with irregular contours mimicking breast cancer treatment set-up. Conclusion : Developed algorithm could accurately reflect the effect of tissue deficit and irregularly shaped body contour on transmission dosimetry.

• Journal of the Korean Society of School Health
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• v.4 no.2
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• pp.136-145
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• 1991

In the Soviet Union School health services are provided as an integral part of the health care delivery system, which is under the Ministry of Health. This paper presents an overview of the Soviet Union's health care delivery system, the model for the delivery of school health service, the role and training of school personnel involved in school health services and implications the Soviet model may have for the countries. 1. School health services are a part overall Soviet health system under the Ministry of Health. 2. Municipal and rural health departments implement programs at the local level. Diagnosis and treatment are conducted through "polyclinics" that are outreach divisions of a district hospital. 3. Education institutions for the development of health manpower, including medical schools and nursing schools, are under the Ministry of Health, as are medical and scientific search institutes.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.509-518
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• 1993

Background: By amplifying small amount of DNA, polymerase chain reaction (PCR) can be used for the detection of very small amount of microbial agent, and may be especially useful in certain cases which are difficult to be diagnosed microbiologically or serologically. Tuberculous pleurisy is a disease that can be diagnosed in only 70% of cases by conventional diagnostic tools, and PCR would be a very rapid, easy, and sensitive diagnostic method. Method: The specificity and sensitivity of PCR to detect Mycobacterium tuberculosis DNA were evaluated using various strains of Mycobacteria. To evaluate the diagnostic usefulness of PCR in tuberculous pleurisy, we used PCR to detect Mycobacterium tuberculosis DNA in pleural fluid. The amplification target was 123 base pair DNA, a part of IS6110 fragment, 10~16 copies of which are known to exist per genome. The diagnostic yield of PCR was compared with conventional methods, including pleural fluid adenosine deaminase (ADA) activity. Also, the significance of PCR in undiagnosed pleural effusion was evaluated prospectively with antituberculosis treatment. Results: 1) Using cultured Mycobacterium tuberculosis and other strains, PCR could detect upto 1 fg DNA and specific for only Mycobacterium tuberculosis and Mycobacterium bovis. 2) Using pleural effusions of proven tuberculosis cases, the sensitivity of PCR was 80.0% (16/20), and the specificity 95.0% (19/20). 3) Among 13 undiagnosed, but suspected tuberculous effusion, the positive rate was 60% in 10 improved cases after antituberculosis medications, and 0% in 3 cases of proven malignancy later. 4) Adenosine deaminase level of proven and clinically diagnosed tuberculous pleurisy patients was significantly higher than that of excluded patients, and correlated well with PCR results. Conclusion: We can conclude that PCR detection of Mycobacterium tuberculosis in pleural effusion has acceptable sensitivity and specificity, and could be an additional diagnostic tool for the diagnosis of tuberculous pleurisy.