• Title/Summary/Keyword: Medical use

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The Clinical Usefulness of a Repeat Urine Culture 48 Hours after Antimicrobial treatment in Anatomically Normal and Abnormal Urinary Tract Infection (소아 요로 감염증 환아의 항생제 치료 48시간 후 반복적 요 배양 검사의 임상적 유용성)

  • Park, Kyung-Hee;Yeom, Jung-Suk;Park, Ji-Suk;Park, Eun-Sil;Seo, Ji-Hyun;Lim, Jae-Young;Park, Chan-Hoo;Youn, Hee-Shang
    • Childhood Kidney Diseases
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    • v.13 no.1
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    • pp.49-55
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    • 2009
  • Purpose : We aimed to compare the frequency of positive repeat urine cultures 48 hours after antimicrobial treatment between anatomically normal and abnormal urinary tract Infection (UTI) groups to determine the potential clinical usefulness of the tests. Methods : We reviewed medical records of 930 patients under age 14, who had been admitted for UTI at Gyeongsang National University Hospital from January 1, 1998 to August 1, 2008. The eligible patients were divided into two groups the anatomically normal UTI group and the anatomically abnormal UTI group. Statistical analyses were performed with variables consisting of the sex ratio, age distribution and the frequency of positive repeat urine cultures of each group. Results : The sex ratio of the anatomically normal UTI group was M:F=1.9:1, whereas that of the anatomically abnormal UTI group was M:F=3.5:1 (P=0.019). For age distribution, it was found that the mean age of the anatomically normal UTI group was $0.82{\pm}1.83$ years, whereas that of the anatomically abnormal UTI group was $1.18{\pm}2.57$ years (P=0.113). The frequency of positive repeat urine cultures in the anatomically normal UTI group was 3/279 (1.1%), whereas that of the anatomically abnormal UTI group was 1/90 (1.1%) (P=0.675). Conclusion : We conclude that performing a repeat urine culture is not justified in terms of clinical usefulness, and it is unreasonable to use the results as an index of therapeutic success. A follow-up urine culture is unnecessary in patients with both the anatomically normal and abnormal UTI group.

A Study on the Establishment of Management Methods about Occupational Dermatoses (직업성 피부질환에 대한 현황 파악 및 관리 대책 수립을 위한 연구)

  • Lim, Hyun-Sul;Cheong, Hae-Kwan;Choi, Byung-Soon;Kim, Ji-Yong;Sung, Yeol-Oh;Kim, Yang-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.29 no.3 s.54
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    • pp.617-637
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    • 1996
  • Occupational dermatosis is one of the most prevalent occupational disorders. However, the extent of the occupational dermatoses including incidences and prevalencies of each disease entity, and etiologic materials are not yet welt stated in Korea. Authors reviewed the literatures on the statistic data and reports on the occupational dermatoses, and surveyed on the occupational dermatoses in two factories, and surveyed the physicians responsible to the occupational dermatoses with formed questionnaire. The results are as follows; 1. Among medical journals published since 1964, there were 31 articles on the occupational dermatoses. Of 31 articles, 18 were case reports and all others were review articles. Of 18 case reports, 9 were epidemiologic survey. The Workers' Periodic Health Examinations revealed that prevalence of the occupational dermatoses was highest(4.36 per 10,000 workers) in 1974, but number of the cases reported were decreased sharply since 1978 with some tendency to increase since 1981. There were 2,240 reported cases of occupational dermatoses between 1966 and 1992, which is 1.90% of all the reported occupational diseases. Skin infection and injuries due to chemicals were most frequent and there were 6 cases of skin cancer. 2. In an epidemiological survey on the dermatoses among 995 workers in a metal product manufacturing factory and 225 workers in a coal chemical factory, there were 794 with dermatomycosis, 296 workers with acne, 130 workers with scar, 123 workers with deformity of toe nails. Scars, photosensitivity dermatitis, deformity of finger and toe nails, and acne were more prevalent in the metal product manufacturing factory(p<0.05). In the metal prouct manufacturing factory, workers treating organic solvents and oils had more dermatoses than those without treating the materials(p<0.05). On the skin patch performed on 16 workers in the metal product manufacturing factory, there were 8 cases of irritation dermatitis and 5 cases of contact dermatitis. Prevalence of contact dermatitis in the metal product manufacturing factory was 1.3%. 3. On the questionnaire survey, 34 dermatologists, 29 doctors of preventive medicine, and 22 family physician replied. The proportion of occupational etiology among all dermatoses assumed by the physicians were below 9%, and the most important occupational dermatosis in Korea was contact dermatitis. Main etiologic materials related to the occupational dermatosis were organic solvent, acid and alkali, and metals. The reason for the scarcity of report of occupational dermatoses were difficulty in diagnosis and physician's ignorance of the occupational etiology. They replied that to prevent the occupational dermatoses in the workplace, the use of protective devices was most important, and development of diagnostic criteria on the occupational dermatoses is urgent. Above results shows us that there is many workers with occupational dermatoses, but they are mostly unreported. Measures to prevent and manage the occupational dermatoses are not satisfactory at present. Hence, authors suggest measures for the precise diagnosis, report and prevention of the occupational dermatoses. a. Dermatologist, preventive physician, and industrial hygienist should work as a team to examine the high risk group and establish the preventive measures. b. Disease entities, diagnostic criteria of occupational dermatoses should be listed, criteria for the compensation and job fitting at recruitment should be established, and manual for the proper treatment and effective prevention of each occupational dermatosis should be developed. c. Patch test antigens against each occupational category should be developed and it should be available to any physicians responsible. d. To facilitate the diagnosis of occupational dermatoses by the doctors responsible for the Workersr Periodic Health Examination, development of standardized questionnaire, education on the techniques of the patch test, and cooperation with the dermatologist in diagnosis of occupational dermatoses is essential.

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Initial Prednisolone Treatment for Primary Nephrotic Syndrome in Children-4 Weeks versus 6 Weeks (일차성 신증후군 환아의 첫 관해를 위한 4주와 6주 스테로이드 치료 비교)

  • Choi Jung Youn;Park Mi Young;Kim Hye Suk;Lee Kyung Hoon;Kim Jun Sik;Park Yong Hoon
    • Childhood Kidney Diseases
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    • v.9 no.2
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    • pp.159-166
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    • 2005
  • Purpose : Recently the merits of 6 weeks of initial prednisolone treatment for pediatric primary nephrotic syndrome have been reported, and the use of the 6 week regimen is increasing. We compared our experiences with the 6 week treatment versus the 4 week treatment for Korean patients. Methods : We conducted a retrospective analysis of 69 children who had primary nephrotic syndrome and who were followed up for at least 12 months in the 4 major medical centers in Daegu. The remission rate, the relapse rate, the frequency of relapse and complication of steroid treatment were compared between the 4 weeks and 6 weeks treatment group. Results : Of the 69 children, 42 were in the 4 week treatment group and 27 were in the 6 week group. The median age, blood pressure, serum total protein, serum albumin, cholesterol, creatinine, estimated creatinine clearance, 24 hour urine protein and 12 month cumulative dose did not differ between the two groups. Among the children who relapsed after steroid treatment, the relapse time was significantly later for the 6 week treatment group. The relapse rate after 1 year of treatment was 62$\%$ in the 4 week treatment group and 52$\%$ in the 6 week treatment group; however, there was no statistically significant difference between the two groups. The frequency of relapse at 12 months was $1.5{\pm}1.2$ times in the 4 week treatment group and $1.1{\pm}1.2$ times in the 6 week treatment group, and there was not different between the two groups. The most common side effects of steroid treatment were an increase of appetite and a cushingoid appearance, and there was no statistical difference between the two groups. Among the 27 children who had kidney biopsies performed, 21 suffered from minimal change nephrotic syndrome. Conclusion : The first relapse time after steroid treatment was significantly later in the 6 week steroid treatment group. The frequency of relapse and the 12 month cumulative dose of steroid were lower in the 6 week treatment group, but there was no statistical significance between the two groups. The side effects of steroid treatment did not differ between the two groups. We need to study the long term side effects and the advanced regimens of steroid treatment in the future.(J Korea Soc Pediatr Nephrol 2005;9:159-166)

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A Study on the Factors Affecting Health Promoting Lifestyles of Some Workers (일부 직업인의 건강증진생활양식에 영향을 미치는 요인 연구)

  • Lee Eun-Kyoung;An Byung-Sang;Yu Taek-Su;Kim Seoung-Cheon;Jeung Jea-Yeal;Park Young-Shin;Jahng Doo-Sub;Song Yung-Sun;Lee Ki-Nam
    • Journal of Society of Preventive Korean Medicine
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    • v.4 no.2
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    • pp.119-141
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    • 2000
  • The current industrial health service is shifting to health improvement business with 1st primary prevention-focused service from secondary and tertiary prevention-focused business, and Oriental medicine can provide such primary prevention-focused service due to the characteristics of its science. In particular, the advanced concept of health improvement can match the science of health care of Oriental medicine. Notably, what is most important in health improvement is our lifestyle, This does not underestimate the socio-environmental factors, which have lessened their importance due to modernism. The approach of Oriental medicine weighs more individuals' lifestyle and health care through self-cultivation. This matches the new model of advanced health business. Oriental medicine is less systemized than Western medicine, but it can provide ample contents that enhance health. If we conceive health-improvement program based on the advantages provided by these two medical systems, this will influence workers to the benefit of their health. Also, health Program needs to define factors that determine individual lives, and to provide information and technologies essential to our lives. The Oriental medicine approach puts more stress on a subject's capabilities than it does on the effect his surrounding environment can have. This needs to be supported theoretically by not only defining the relations between an individual's health state and his lifestyle, but also identifying the degree to which an individual in the industrial work place practices health improvement lifestyle . This is the first step toward initiating health-improvement business . In order to do this, this researcher conducted a survey by taking random samplings from workers, and can draw the following conclusions from it. 1 The sampled group is categorized into', by sender, female 6.6%, and male 93.4%, with males dominant; by marriage status , unmarried 43.9% and married 55.6%, with both similar percentage, and, by age, below 30, 48.4%, between 30 and 39, 27.4%, between 40 and 49, 18.2%, and over 50, 6.0%. The group further is categorized into; by education, middle school or under 1.7%, high school 30.5%, and junior college or higher 65.8% with high school and higher dominant: and by income, below 1.7 million won 24.2%, below 2.4 million won 14.8%, and above 2.4 million 6.3% Still, the group by job is categorized into collegians with 23.9%, office worker with 10.3%, and professionals with 65.8% , and this group does not include workers engaged in production that are needed for this research, but mostly office workers . 2. The subjects selected for this survey show their degree of practicing health-improvement lifestyle at an average of 2.63, health management pattern at 2.64, and health-related awareness at 2.62 The sub-divisions of health-improvement lifestyle show social emotion (2.87), food (2.66). favorite food (2.59), and leisure activities (2.52), in this order for higher points. It further shows health awareness (2.47) and safety awareness (2.40), lower points than those in health management pattern . 3. In the area of using leisure time for health-improvement, males, older people, married, and people with higher income earn higher marks. And, in the area of food management, the older and married earn higher marks . In the area of favorite food management, females, lower-income bracket, and lower-educated show higher degree of practice , while in the area of social emotion management, the older. married, and higher-income bracket show higher marks. In addition, in the area of health awareness, the older, married, and people with higher-income show higher degree of practice. 4. To look at correlation by overall and divisional health-improvement practice degree , this researcher has analyzed the data using Person's correlation coefficient. The lifestyle shows significant correlation with its six sub-divisions, and use of leisure time, food, and health awareness all show significant correlation with their sub-divisions. And. the social emotion and safety awareness show significant correlation with all sub-divisions except favorite food management.

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The Effect of a Chest CT Scan on the Treatment and Diagnosis of Major Blunt Chest Trauma (흉부 둔상환자에서 흉부전산화단층촬영이 진단과 치료에 미치는 영향)

  • Park, Il-Hwan;Oh, Joong-Hwan;Lee, Chong-Kook
    • Journal of Chest Surgery
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    • v.42 no.2
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    • pp.226-232
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    • 2009
  • Background: Blunt chest trauma accounts for 90% of all chest traumas in Europe and the United States and this causes 20% of all trauma-related deaths. The major cause of morbidity and mortality after blunt chest trauma is undetected injuries. For this reason, chest computerized tomography has gained popularity for the evaluation of trauma, but it is expensive and it exposes patients to radiation. This study identified the clinical features associated with the diagnosic information obtained on a CT chest scan, as compared with a standard chest X-ray, for patients who sustained blunt trauma to the chest. This study also evaluated the role of a routine computed tomographic (CT) scan for these patients. The patients who had chest computed tomography done after the initial chest x-ray were analyzed separately for the presence of occult injuries. Material and Method: We studied 100 consecutive patients from November 2006 to July 2007: 74 patients after motor vehicle crashes and 26 patients after a fall from a height >2m. Simultaneous with the initial clinical evaluation, an anteroposterior chest radiograph and a helical chest CT scan were obtained for all the patients. The data extracted from the medical record included the vital signs, the interventions and the type and severity of injury (RTS). Result: Among the 100 cases, 79 patients showed at least more than one pathologic sign on their chest radiograph, and 21 patients had a normal chest radiograph. For 17 of the patients who had a normal chest X ray, the CT scan showed multiple injuries, which were pneumothorax, hemothorax, lung contusion, sternal fracture etc. This represents that a CT scan is statistically superior to a chest radiograph to diagnose the pathologic signs. But on the other hand, as for treatment, only 31 patients were diagnosed by CT scan and they were treated with chest tube insertion ect. 42 patients needed ony conservative management without invasive thoracosurgical treatment such as chest tube insertion or open thoracotomy. 27 patients were treated based on the diagnosis made by the chest radiograph and physical examination. Conclusion: Chest computerized tomography was significantly more effective than routine chest X-ray for detecting lung contusion, pneumothorax and mediastinal hematoma, as well as fractured ribs, scapula and, sternum. Although the occult findings increased, the number of patients who needed treatment was small. Therefore, we suggest making selective use of a CT scan to avoid its overuse in ERs.

Development of the Somatization Rating Scale (신체화 평가 척도의 개발)

  • Koh, Kyung-Bong;Park, Joong-Kyu
    • Korean Journal of Psychosomatic Medicine
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    • v.10 no.2
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    • pp.78-91
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    • 2002
  • Objective : The purpose of this study was to develop the somatization rating scale (SRS), and then to use the scale in clinical pracitice. Methods: First, a preliminary survey was conducted for 109 healthy adults to obtain 40 response items. Second, a preliminary questionnaire was completed by 215 healthy subjects. Third, a comparison was made regarding somatization responses among 242 patients (71 with anxiety disorder. 73 with depressive disorder, 47 with somatoform disorder, and 51 with psychosomatic disorder) and 215 healthy subjects. Results : Factor analysis yielded 5 subscales : cardiorespiratory and nervous responses, somatic sensitivity, gastrointestinal responses, general somatic responses, genitourinary, eye and muscular responses. Reliability was computed by administering the SRS to 62 healthy subjects during a 2-week interval. Test-retest reliability for 5 subscales and the total score was significantly high, ranging between .86-.94. Internal consistency was computed, and Cronbach's ${\alpha}$ for 5 subscales ranged between .72-.92, and .95 for the total score. Convergent validity was computed by correlating the 5 subscales and the total score with the total score of the global assessment of recent stress (GARS) scale, the perceived stress questionnaire (PSQ), and the symptom checklist-90-revised (SCL-90-R). The correlations were all at significant levels. Discriminant validity was computed by comparing the total score and the 5 subscale scores of the patient and control groups. Significant differences were found for 5 subscales and the total score. Only the depressive disorder group was siginificantly higher than control group in all the subscale scores and total scores of SRS among 4 patient groups. In somatic sensitivity, only depressive disorder patients were significantly higher than the normal controls, whereas in general somatic subscale, depressive disorder and somatoform disorder groups were significantly higher than the normal controls. In total scores of the SRS, female subjects were significantly higher than males. Conclusion : These results indicate that the SRS is highly reliable and valid, and that it can be utilized as an effective measure for research in stress- and somatization-related fields. The depressive disorder and somatoform disorder groups showed more widespread somatization than the anxiety and psychosomatic disorder groups.

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Current status of meal and snack service in elementary care classes in Gyeonggi area (경기도 지역 초등돌봄교실의 급·간식 운영 현황)

  • Yang, Hee Soon;Park, Haeryun;Song, Kyunghee;Ahn, Yoonjin;Choi, Daeun;Jin, Juntai;Lee, Youngmi
    • Journal of Nutrition and Health
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    • v.51 no.3
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    • pp.264-274
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    • 2018
  • Purpose: This study aimed to investigate the current status of food service management in elementary care classes. Methods: A focus group interview with seven care class managers and a survey with 101 care class managers using a self-administered questionnaire in Gyeonggi province were conducted. Results: In the focus group interview, purchased meals and snacks were evaluated as low quality by the care class managers. Frequent use of frozen or processed food and products with low prices were also reported as problems. Care class managers were in charge of meal and snack planning without any guidelines or expert advices. The results of the survey show that most schools serve purchased snacks and meals. The average unit costs of one meal and snack were 4,062 and 1,463 Won, respectively. The average unit costs of snacks during semester (p = 0.015) and vacation (p = 0.039) were significantly lower in rural than urban areas. The percentages of schools that prepared nutrition standards for meal and snack planning in elementary care classes were only 7.4% and 10.9%, respectively. The meal menus were mostly provided by catering service companies, and the snack menus were planned mostly by the care class managers. Menu planning by the care class managers was more usual in rural than urban areas (p = 0.054 for meal planning and p = 0.008 for snack planning). Just 33.7% of schools introduced safety standards for food service in elementary care classes, and more than half of the respondents (56.4%) did not do a regular medical check-up. Only 33.7% of the respondents received education for food safety. Conclusion: These results show the necessity for establishment of detailed guidelines for food service in elementary care classes and for the introduction of a food safety and nutrition education program customized for care class managers.

A survey on sex life behavior and factors of low back pain (요통환자들의 성생활 행태와 영향 요인 조사)

  • Nam, Chul-Hyun;Woo, Kwang-Seog
    • Journal of Korean Physical Therapy Science
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    • v.9 no.3
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    • pp.31-49
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    • 2002
  • The purpose of this study was to investigate discomforts and sexual life and to identify the relation between the discomforts and sexual life with low back pain. The data were collected from March 2 through July 31, 2001. Four hundred forty-two questionnaires were returned (response rate=88.0%). Analysis of the data was done with SPSS PC+ and use descriptive statistics, $x^2$-test, t-test, ANOVA. regression. The statistics shows that over than 80% of the adults experienced lumbago at least one time in their life, and Back pain is known as one of the most common complaints made by the patients of all ages in the general hospital or local medical clinics throughout. However, in certain case it leads to a chronic condition which can cause a great deal of problems in management and in financial burden to individuals and society. The result of this study was summarized as follows: 1) It appeared that regarding the distribution of gender, male was the higher(63.6%) then that of female, the portion of forties was 28.5%. Sitting for long time was 23.1% in men and 21.7% in women. Unknown reason including sexual behaviour was 12.9% in men and 15.5% in women. Patients treated medicine and physical therapy were 36.4%. In level of educational background, the rate of high school was 31.0%, technical college was 28.5%. The highest proportion by occupation was 18.3% of office workers, occupation posture was 41.9% of sitting. 2) Men(26.0%) and most of women(34.8%) were not satisfied in the explanation satisfaction rate of sex life concerned disease. 23.8% in men and 23.6% in women considered flexibility of waist good. Man(33.3%) and most of woman(35.0%) considered that Health education is necessary. 32.7% in men and 27.3% in women did't mind educator is whoever. Preventing of lower back pain(LBP) and proper Health education of sex life are demanded in daily life. 3) 58.0% of man and 64.0% of woman mostly had a posture which is man over woman. 28.5% in men and 27.8% in women considered that proper information finding of LBP and sex life was very few and few. 37.7% in men and 42.7% in women have acquired information about sex life flung their friends. 4) The number of sex life was decreased from 2.96 0.98 to 2.61 1.63 and also the time of sex life was decreased from 3.65 1.89 to 226 1.64. The satisfaction rate of sex life changed from 3.60 0.86 to 2.77 1.10. In the number of sex life, The non correct group was 2.62 1.91 and the correct group was higher in 2.68 1.65. In the time of sex life, The non correct group was 2.02 1.47 and the correct group was higher in 229 1.65. The satisfaction rate of sex life was 2.76 0.86 in non correct group and 2.88 1.10 in correct group. So there was a difference. 5) In the satisfaction rate of sex life, Men who have a lower back pain were higher than women and no attack group was higher than attack group. As they had many sex life, the satisfaction rate was higher significantly in statistics. As the time of sex life was short, the satisfaction rate was lower significantly in statistics. As the age was low, the demand rate of Health education was high and as means of patient who had a lower back pain was high, the demand rate of Health education was high. As the patient who had a lower back pain had a long married life, the demand rate of Health education was high and as education level was high, the demand rate of Health education was high. It is necessary to provide patients with conservative treatment, educational teaching, and training to prevent further injuries in the future. In general, it is important to educate the public how to prevent back injuries and how to treat themselves in an onset period to prevent further injuries sliding into a chronic state. Sexuality is an integral part of normal and healthy relationships, but patients are unable to enjoy sex because they are riot able to get into a comfortable position due to back pain. Many conditions of the spine can make certain positions uncomfortable. Health educator should make the education program of the discomforts and the sexual pattern for low back pain in workplace and/or hospital. Further study Is needed on how to integrate the educational program on sexuality into the total rehabilitation program.

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A Domestic Outbreak of Bacterial Dysentery Caused by Extended-Spectrum β-Lactamase(ESBL)-producing Shigella sonnei (집단 발생한 Extended-spectrum β-lactamase(ESBL) 생산 Shigella sonnei 감염에 의한 세균성 이질에 관한 연구)

  • Lim, Hyun Taek;Lee, So Hee;Lee, Jung Hwa;Kim, Jeong Eun;Kim, Kyo Sun;Jeong, Eun Ju;Lee, Seung Hyun;Kang, Chang Gyu;Hong, Seong Jin
    • Clinical and Experimental Pediatrics
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    • v.48 no.10
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    • pp.1107-1115
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    • 2005
  • Purpose : An outbreak of ESBL-producing Shigella sonnei enteritis was unprecedented not only in Korea but throughout the world in the past. We intended to devise a management guideline for ESBL-producing shigellosis based on analysis of clinical manifestations and response to therapy. Methods : We analyzed 103 patients who were admitted to the hospital with acute GI symptoms and were shown positive result for S. sonnei on stool culture. We performed sensitivity test to the antibiotics and DNA sequencing of ESBL gene in the isolated S. sonnei colonies. In addition, we retrospectively analyzed their clinical characteristics, laboratory results, and clinical and microbiological responses to the antibiotics. Results : Among the clinical manifestations, fever was the most frequent(96.1%), followed by diarrhea(93.2%), abdominal pain(76.7%), headache(71.8%), vomiting(65.0%), and nausea(41.7%). The fever was sustained for average of 2.0 days and diarrhea for 3.9 days. Watery diarrhea was the most common(69%) followed by mucoid(26%), and bloody stool(5%). On peripheral blood smear, leukocytosis was noted in 53.4% of patients, and 78.6% of patients tested positive for serum CRP response. On stool direct smear, 11.7% of patients showed more than 50 WBCs/HPF, and 9.7% of patients between 5 to 20 WBCs/HPF. Stool occult blood was positive in 71% of patients. Production of CTX-M-14 type ESBL was reported for all S. sonnei strains isolated from this outbreak. Microbiological eradication rates to various antibiotics were as follows : 100%(9/9) to ciprofloxacin, 100% 5/5) to azithromycin, 6.9%(5/72) to cefdinir, 0%(0/8) to ceftriaxone, 12.5%(1/8) to ceftizoxime, 0%(0/ 8) to TMP/SMX, 42.9%(3/7) to ampicillin/sulbactam, 20%(1/5) to amoxicillin/clavulanic acid, and 68.8 %(11/16) to imipenem/cilastatin. Conclusion : It is presumed that azithromycin can be an attractive option for the treatment of ESBL-producing S. sonnei enteritis in pediatric population, given its cost-effectiveness and safety. Although ciprofloxacin is another cost-effective agent, its use in pediatric population may be a bit too premature.

THE CURRENT STATUS OF BIOMEDICAL ENGINEERING IN THE USA

  • Webster, John G.
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.27-47
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    • 1992
  • Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

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