• Journal of Radiation Protection and Research
• /
• v.37 no.4
• /
• pp.208-212
• /
• 2012

In previous studies, ovarian follicle in rat has been used a higher radiation dose than that for cancer radiotherapy in clinical practice. The aim of this study was to evaluate the effect of radiation dose used for cancer radiotherapy on ovarian follicle atresia in rat. Mice of 4-week-old female were whole body irradiated with 2 cGy or 2 Gy (Mevatron 67, Siemens, Germany) and sacrificed by cervical dislocation. Ovaries were collected at 24 hours after irradiation to observe the degree of follicular atresia. Ovaries were fixed in neutral formaldehyde solution for 24 hours and embedded with paraffin. Cutted in $5{\mu}m$ thickness with microtome and stained with hematoxylin and eosin (H&E) and TUNEL immunohistochemical stain, and examined histologically under a light microscope. All data were presented as mean ${\pm}SD$, calculating the ratio of normal or atretic follicles to total ovarian follicles. Statistical analysis was performed by the Mann Whitney test using the SPSS ver 19.0. Ratio of atretic to total follicles of 2 Gy group was significantly higher than control or 2 cGy groups (p<0.05). Ratio of normal to total follicles of 2 Gy group was significantly lower than control group in preantral follicle (64.0 vs. 87.7, p=0.027). Ratio of normal to total follicles of 2 cGy group was significantly increased more than control or 2 Gy groups in antral follicle, and there were no significant difference between control and 2 Gy groups (p=0.522). Radiation dose of 2 Gy for cancer radiotherapy have a significant effect on ovarian follicle atresia in rat.

• Tuberculosis and Respiratory Diseases
• /
• v.39 no.5
• /
• pp.386-391
• /
• 1992

Background: Recently, bronchial provocation of the airway of atopic asthmatic subjects with inhaled allergen has been shown to produce an initial peripheral blood eosinopenia followed by an eosinophilia occurring approximately 12 to 18 hrs after the challenge. However there are few studies about the change of peripheral eosinophil count (PEC) after bronchial provocation with nonspecific stimuli such as histamine or methacholine. Interestingly our preliminary study demonstrated a notable change of PEC during bronhial provocation with inhaled histamine in some asthmatic subjects. This study was designed to reevaluate our preliminary data and to further investigate the change of PEC during as well as after bronchial provocation with inhaled histamine in bronchial asthma tics. Methods: Sixteen asthmatic subjects participated in this study. Bronchial provocation with inhaled histamine was done between 9 AM and 12 MD. Blood samplings for PEC were done with 5 minutes intervals during the procedure, and repeated at 1 hour, 2 hours, 4 hours, 8 hours, 24 hours, and 48 hours after the procedure. Results: The results were as follows; 1) The patients were divided into two groups characterized by each pattern in the change of PEC during the procedure. A group (11 of sixten, group I) showed an increasing pattern of PEC and another group (5 of sixteen, group II) showed a decreasing pattern of PEC during the procedure. 2) Group I demonstrated a tendency to maintain continuously higher level of PEC than the baseline value until 48 hours after the procedure. 3) Group II demonstrated a tendency to maintain continuously lower level of PEC than the baseline value until 48 hours after the procedure. 4) There were no significant differences in their clinical parameters including baseline eosinophil count, baseline $FEV_1$, $PC_{20}$ of histamine, and serum IgE level between group I and group II. Conclusion: Our results suggest that the change of PEC produced by inhaled histamine in asthmatic subjects is much different from that produced by inhaled allergen, and that each patient may have their individual characteristics in the change of PEC in response to bronchial provocation with inhaled histamine. Alternatively these findings suggest that eosinophils may be partially involved in the early asthmatic reaction.

• Clinical and Experimental Pediatrics
• /
• v.46 no.8
• /
• pp.758-762
• /
• 2003

Purpose : Our examination was designed to determine the diagnostic properties of the cutoff point for the prediction of bacteremia in febrile children less than 3 years of age. Cutoff point is the value that simultaneously maximizes both sensitivity and specificity. Methods : We conducted a retrospective study of febrile children, less than 3 years of age, who clinically have no identifiable source of fever. Peripheral blood leukocyte count(WBC), absolute neutrophil count(ANC), erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) were measured at the same time. All patients received blood culture, urine culture and/or CSF culture. Bacterial infection was defined as single pathogen isolated from the CSF or blood or a urinary tract infection (UTI). Patients were dichotomized into two groups : those with bacterial infection and no bacterial infection. We analyzed the characteristics of the children in the two groups. Results : Seventy-one patients(44 males; 27 females) were enrolled in the study. Twenty patients (28%) had a serious bacterial infection(twelve urinary tract infection, five bacteremia, three meningitis) and fifty-one(72%) had no serious bacterial infection. WBC, ESR and CRP were significantly different between the two groups(P<0.05). The cutoff point of WBC, ESR and CRP were $20,000/mm^3$, 30 mm/hr and 3.0 mg/dL, respectively. The sensitivity and specificity of each cutoff point were WBC(75%, 75%), ESR(79%, 68%) and CRP(83%, 77%), respectively. Conclusion : These data show the ability of predictors to identify febrile children less than 3 years of age with bacterial infection. Febrile children who reach the cutoff point must be treated intensively and those who do not reach the cutoff point can be carefully managed without administering antimicrobial agents.

• Progress in Medical Physics
• /
• v.26 no.1
• /
• pp.28-35
• /
• 2015

In this study, we investigated the effects of an iterative reconstruction algorithm and an automatic exposure control (AEC) technique on image quality and radiation dose through phantom experiments with coronary computed tomography (CT) angiography protocols. We scanned the AAPM CT performance phantom using 320 multi-detector-row CT. At the tube voltages of 80, 100, and 120 kVp, the scanning was repeated with two settings of the AEC technique, i.e., with the target standard deviations (SD) values of 33 (the higher tube current) and 44 (the lower tube current). The scanned projection data were reconstructed also in two ways, with the filtered back projection (FBP) and with the iterative reconstruction technique (AIDR-3D). The image quality was evaluated quantitatively with the noise standard deviation, modulation transfer function, and the contrast to noise ratio (CNR). More specifically, we analyzed the influences of selection of a tube voltage and a reconstruction algorithm on tube current modulation and consequently on radiation dose. Reduction of image noise by the iterative reconstruction algorithm compared with the FBP was revealed eminently, especially with the lower tube current protocols, i.e., it was decreased by 46% and 38%, when the AEC was established with the lower dose (the target SD=44) and the higher dose (the target SD=33), respectively. As a side effect of iterative reconstruction, the spatial resolution was decreased by a degree that could not mar the remarkable gains in terms of noise reduction. Consequently, if coronary CT angiogprahy is scanned and reconstructed using both the automatic exposure control and iterative reconstruction techniques, it is anticipated that, in comparison with a conventional acquisition method, image noise can be reduced significantly with slight decrease in spatial resolution, implying clinical advantages of radiation dose reduction, still being faithful to the ALARA principle.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.4
• /
• pp.500-518
• /
• 1996

Background : The solitary pulmonary nodule(SPN) presents a diagnostic dilemma to the physician and the patient. Many clinical characteristics(i.e. age, smoking history, prior history of malignancy) and radiological characteristics( i.e. size, calcification, growth rate, several findings of computed tomography) have been proposed to help to determine whether the SPN was benign or malignant. However, most of these diagnostic guidelines are based on the data collected before computed tomography(CT) has been introduced and lung cancer was not as common as these days. Moreover, it is not well established whether these guidelines from western populations could be applicable to Korean patients. Methods : We had a retrospective analysis of the case records and radiographic findings in 114 patients presenting with SPN from Jan. 1994 to Feb. 1995 in Seoul National University Hospital, a tertiary referral hospital. Results : We observed the following results ; (1) Out of 113 SPNs, the etiology was documented in 94 SP IS. There were 34 benign SP s and 60 malignant SPNs. Among which, 49 SPNs were primary lung cancers and the most common hi stologic type was adenocarcinoma. (2) The average age of patients with benign and malignant SPNs was $49.7{\pm}12.0$ and $58.1{\pm}10.0$ years, respectively( p=0.0004), and the malignant SPNs had a striking linear propensity to increase with age. (3) No significant difference in the hi story of smoking was noted between the patients with benign SPNs($13.0{\pm}17.6$ pack- year) and those with malignant SPNs($18.6{\pm}25.1$ pack-year) (p=0.2108). (4) 9 out of 10 patients with prior history of malignancy had malignant SPNs. 5 were new primary lung cancers with no relation to prior malignancy. (5) The average size of benign SPNs($3.01{\pm}1.20cm$) and malignant SPNs($2.98{\pm}0.97cm$) was not significantly different(p=0.8937). (6) The volume doubling time could be calculated in 22 SPNs. 9 SPNs had the volume doubling time longer than 400 days. Out of these, 6 were malignant SPNs. (7) The CT findings suggesting malignancy included the lobulated or spiculated border, air- bronchogram, pleural tail, and lymphadenopathy. In contrast, calcification, central low attenuation, cavity with even thickness, well-marginated border, and peri nodular micronodules were more suggestive for benign nodule. (8) The diagnostic yield of percutaneous needle aspiration and biopsy was 57.6%(19/33) of benign SPNs and 81.0%(47/58) of malignant SPNs. The diagnostic value of sputum analysis and bronchoscopic evaluations were relatively very low. (9) 42.3%(11/26) of SPNs of undetermined etiology preoperatively turned out to be malignant after surgical resection. Overall, 75.4%(46/61) of surgically resected SPNs were malignant. Conclusions : We conclude that the likelihood of malignant SPN correlates the age of patient, prior history of malignancy, some CT findings including lobulated or spiculated border, air-bronchogram, pleural tail and lymphadenopathy. However, the history of smoking, the size of the nodule, and the volume doubling time are not helpful to determent whether the SPN is benign or malignant, which have been regarded as valuable clinical parameters previously. We suggest that aggressive diagnostic approach including surgical resection is necessary in patient with SPNs.

• Clinical and Experimental Pediatrics
• /
• v.48 no.7
• /
• pp.716-722
• /
• 2005

Purpose : A full view of the spectrum of all bacterial diseases in healthy children is essential to the establishment of public health priorities. Accurate information on the relative importance of the various pathogens in terms of the age of the affected patients, the site of infection and the case fatality rate are valuable to the clinician in choosing antimicrobial treatments. Methods : Fifty-nine episodes of bacteremia were analysed. Data were collected at Ilsan Paik Hospital from January 2000 to December 2003. Analysis of each collected episode included isolating pathogen from blood culture, diagnosis, hospital course, isolating pathogens from other tissue sites, and studying results of antimicrobial sensitivity tests. Results : Fifty-nine cases of community-acquired bacteremia were reviewed. The most common pathogen was Staphylococcus aureus(11 cases, 18.6 percent), followed by Salmonella(10 cases, 16.9 percent), E. coli(7 cases, 11.9 percent), Streptococcus pneumoniae(five cases, 8.5 percent), Streptococcus viridans(5 cases 8.5 percent). The most common diagnosis was bacteremia without an indentified focus(61 percent), followed by meningitis(12 percent), bacteremia with enteritis(10.2 percent) and bacteremia with urinary tract infection(8.5 percent). Salmonella was still an important causative agent of bacteremia. The relative importance of Haemophilus influenza and Streptococcus pneumoniae was lower than in other studies. The most common organism responsible for bacteremia without an identified focus was Staphylococcus aureus. The case-fatality was 3.4 percent for all cases of bacteremia. Conclusion : We reviewed the etiology of community-acquired bacteremia. These data may be useful in the establishment of public health priorities and serve as a reference for selection of antibiotics in the empirical therapy of suspected invasive bacterial infection.

• Journal of Korean Academy of Nursing
• /
• v.18 no.2
• /
• pp.162-188
• /
• 1988

The purpose of this study is to guide the direction of the Korean nursing education to analysize ⑴ the philosophy and objectives ⑵ curriculum, and ⑶ educational environment. This analysis is based on the data from 50 nursing schools (14 4-year colleges and 35 3-year colleges) The survey was conducted from Dec. 1986 through Jan. 1987 by mail. 1) Educational philosophy and objectives 10 4-year colleges and 8 3-year college program have curricular philosoph. Most popular curricular philosophies are human beings, health, nursing, nursology, nursing education, nurses role in the present and in the future. 10 nursing schools mentioned that human being is the subject to interact with : environment physically, mentally and socially. 2 schools mentioned that health is the state of functioning well physically, mentally and socially. 13 schools mentioned that the nursing is the dynamic act to maintain and to promote the highest possible level of health. 4 schools mentioned that the nursology is an applied science. 4 schools mentioned that nursing education is the process to induce the behavioural changes based on the individual ability. There is different opinion about the nurses' role between 4-year college and 3-year college. In the responses from 4-year colleges they focus on the leadership in effective changes, self-regulating and self-determining responsibilities, applying the new technology, continuing education, and participation in research to further nursing knowledge. In the responses from 3-year colleges, they focus on the education in college, primary health care nursing, direct care provider and public health education. Among 50 respondents 40 schools have educational goals which can be divided into two categories. One is to establish the moral and the other is to develop the professionalism. 2) Curriculm The analsis of curriculum is only based on the data from the 4-year colleges because the most of 3-year colleges follow the curriculum guideline set by the Ministry of Education. a) Comparison of the credits in cultural subject and in nursing major. The average required credit for graduation is 154.6 and the median credit is the range of 140-149. The average credit of cultural subjects is 43.4. In detail, the average number of credit of required course and elective courses are 24.1 and 19.3 respectively. The average credit for major subject is 111.2. In detail, the average credit for required courses and electives course are 100.9 and 10.4 respectively. In 5 colleges, students are offered even on elective course b) Comparison of the credit by class. The average earned credits are as follows : 41.1 in freshman, 400 in sophormore 38.3 in junior and 32.4 in senior. Cultural subjects are studied in early phases. c) Comparison of the compulsory and elective cultural subject by institute. The range of credit is 7-43 in compulsory cultural subjects and there are lot of differences among institutions. While all respondents require liberal arts as compulsary subjects, few respondents lists social science, natural science and behavioral science as required subjects. Social science-related subjects are frequently chosen as cultural subjects d) Distribution of creditsin cultural subjects by institute. The liberal art subjects are taught in 20 institute. English and physical education courses are taught in all instituions. The social science subjects are taught in 15 colleges and the basic Psycology and the Basic sociology are the most popular subjects. The natural science subjects are taught in 7 colleges and Biology and Chemistry are the most popular subjects among them. e) Distribution of credits in major basic courses by institute. Most of the institutes select Anatomy, Microbiology, Physiology, biochemistry and Pathology as basic major courses. f) Comparison of the required and elective courses for nursing major by institutions. Subjects and credit ranges in major are varing by institute. More than half of the respondents select the following subjects as required major subjects. (1) Adults Health Nursing and Practice (19.5 credits) (2) Mother and Child Care and Practice (8.9 credits) (3) Community Health Care and Practice (8.5 credits) (4) Psychiatric Nursing Care and Practice (8.1 credits) (5) Nursing Management and Practice (3.9 credits) (6) Fundamental of Nursing, Nursing Research and Health Assessment and Practice. Three institutions select Introduction to nursing, Rehabilitation Nursing, School Nursing, Public Health Nursing, Nursing English, Communication, Human Development as electives in nursing major. 3) Educational environment a) Nursing institution There are forty-three 3-year colleges and seventeen 4-year colleges and 81.4% of which are private b) Number of students and faculty 19.2% of the students are in 4-year colleges and 80.8% of the students are in 3-year colleges. In 4-year colleges, the number of nursing faculty members is in the other of assistant professor, instructor and professor. In 3-year colleges, the orderiis lecturer, associate professor, full time instructor and assistant professor. In 4-year colleges, 18.8 students are allocated per nursing faculty and in 3-year colleges, 33.1 students are allocated per nursing faculty. c) Clinical practices 66.7% of the 4-year colleges practice over 1201 hours in clinic and 28.5% of 3-year colleges practice over 1201 hours in clinic. In 4-year colleges, 11.5 students are allocated per nursing faculty and in 3-year colleges,17 students are allocated per nursing faculty The survey shows no difference in the procedure between 4-year colleges and 3-year colleges but 3-year colleges choose the more variety practicing site such as special hospital and community health clinic. d) Audiovisual facilities The survey shows a lot of difference in audiovisual facilities among institution and 3-year colleges are less equipped than 4-year colleges.

• Progress in Medical Physics
• /
• v.21 no.2
• /
• pp.192-200
• /
• 2010

Cyberknife with small field size is more difficult and complex for dosimetry compared with conventional radiotherapy due to electronic disequilibrium, steep dose gradients and spectrum change of photons and electrons. The purpose of this study demonstrate the usefulness of Geant4 as verification tool of measurement dose for delivering accurate dose by comparing measurement data using the diode detector with results by Geant4 simulation. The development of Monte Carlo Model for Cyberknife was done through the two-step process. In the first step, the treatment head was simulated and Bremsstrahlung spectrum was calculated. Secondly, percent depth dose (PDD) was calculated for six cones with different size, i.e., 5 mm, 10 mm, 20 mm, 30 mm, 50 mm and 60 mm in the model of water phantom. The relative output factor was calculated about 12 fields from 5 mm to 60 mm and then it compared with measurement data by the diode detector. The beam profiles and depth profiles were calculated about different six cones and about each depth of 1.5 cm, 10 cm and 20 cm, respectively. The results about PDD were shown the error the less than 2% which means acceptable in clinical setting. For comparison of relative output factors, the difference was less than 3% in the cones lager than 7.5 mm. However, there was the difference of 6.91% in the 5 mm cone. Although beam profiles were shown the difference less than 2% in the cones larger than 20 mm, there was the error less than 3.5% in the cones smaller than 20 mm. From results, we could demonstrate the usefulness of Geant4 as dose verification tool.

• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.2
• /
• pp.172-180
• /
• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• Journal of Korean Medical Science
• /
• v.33 no.52
• /
• pp.346.1-346.11
• /
• 2018

Background: To evaluate the therapeutic benefits of the treat-to-target (T2T) strategy for Asian patients with early rheumatoid arthritis (RA) in Korea. Methods: In a 1-year, multicenter, open-label strategy trial, 346 patients with early RA were recruited from 20 institutions across Korea and stratified into 2 groups, depending on whether they were recruited by rheumatologists who have adopted the T2T strategy (T2T group) or by rheumatologists who provided usual care (non-T2T group). Data regarding demographics, rheumatoid factor titer, anti-cyclic citrullinated peptide antibody titer, disease activity score of 28 joints (DAS28), and Korean Health Assessment Questionnaire (KHAQ) score were obtained at baseline and after 1 year of treatment. In the T2T group, the prescription for disease-modifying antirheumatic drugs was tailored to the predefined treatment target in each patient, namely remission (DAS28 < 2.6) or low disease activity (LDA) ($2.6{\leq}DAS28$ < 3.2). Results: Data were available for 163 T2T patients and 162 non-T2T patients. At the end of the study period, clinical outcomes were better in the T2T group than in the non-T2T group (LDA or remission, 59.5% vs. 35.8%; P < 0.001; remission, 43.6% vs. 19.8%; P < 0.001). Compared with non-T2T, T2T was also associated with higher rate of good European League Against Rheumatism response (63.0% vs. 39.8%; P < 0.001), improved KHAQ scores (-0.38 vs. -0.13; P = 0.008), and higher frequency of follow-up visits (5.0 vs. 2.0 visits/year; P < 0.001). Conclusion: In Asian patients with early RA, T2T improves disease activity and physical function. Setting a pre-defined treatment target in terms of DAS28 is recommended.