• Title/Summary/Keyword: R-function

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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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Antithrombotic Activities of Cheongkookjang and Cheongkookjang Fermented with Green Tea or Mugwort (청국장 및 녹차, 쑥이 첨가된 청국장의 항혈전 활성)

  • Lee, Kyung-Ae;Jang, Jeong-Oak;Yoon, Hye-Kyung;Kim, Moo-Sung
    • Korean Journal of Microbiology
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    • v.43 no.4
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    • pp.298-303
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    • 2007
  • Antithrombotic activities of water extract of cheongkookjang and cheongkookjang fermented with green tea or mugwort were evaluated on some antithrombosis related activities in vitro and thrombotic death inhibition in vivo. Cheongkookjang made of white soybean (Glycine max) or black small soybean (Rhynchosia nulubilis) showed potent antioxidative activities. Addition of green tea or mugwort during cheongkookjang fermentation increased the antioxidative activity, cheongkookjang with green tea showed more drastic increase compared with cheongkookjang with mugwort. Nitrite scavenging effects of the cheongkookjang extracts were prominent but the addition of green tea or mugwort seldom increased the scavenging effects. All the cheongkookjang extracts showed strong inhibitory activities on platelet aggregation. The inhibitory activities of cheongkookjang were increased considerably by addition of green tea or mugwort even with low concentration. Plasmin unit as fibrinolytic activity was not affected considerably by addition of green tea. Addition of mugwort decreased the activity transiently at low concentration ($0.3{\sim}1.0%$) but increased again slowly at higher concentration ($1{\sim}3%$). In vitro thrombotic death inhibition test, the antithrombotic activity of cheongkookjang made of black small bean with green tea was higher by about 1.5 times compared to that without green tea. As results, cheongkookjang might inhibit antithrombosis not only by fibrinolytic action but also by inhibition of platelet aggregation and antioxidative action. The addition of functional materials such as green tea or mugwort could increase the antithrombotic function, even at low concentration.

Change of Lung Volumes in Chronic Obstructive Pulmonary Disease Patients with Improvement of Airflow Limitation after Treatment (치료 후 기류제한이 호전된 만성폐쇄성폐질환 환자에서 폐용적의 변화)

  • Park, Hun Pyo;Park, Soon Hyo;Lee, Sang Won;Seo, Yong Woo;Lee, Jeong Eun;Seo, Chang Kyun;Kwak, Jin Ho;Jeon, Young June;Lee, Mi Young;Chung, In Sung;Kim, Kyung Chan;Choi, Won-Il
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.2
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    • pp.143-147
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    • 2004
  • Background : It is important to predict the exercise capacity and dyspnea, as measurements of lung volume, in patients with COPD. However, lung volume changes in response to an improvement in airflow limitation have not been explored in detail. In the present study, it is hypothesized that lung volume responses might not be accurately predicted by flow responses in patients with moderate to severe airflow limitations. Methods : To evaluate lung volume responses, baseline and follow up, flow and lung volumes were measured in moderate to severe COPD patients. The flow response was defined by an improvement in the $FEV_1$ of more than 12.3%; lung volume changes were analyzed in 17 patients for the flow response. Results : The mean age of the subjects was 66 years; 76% were men. The mean baseline $FEV_1$, $FEV_1$/FVC and RV were 0.98L (44.2% predicted), 47.5% and 4.65 L (241.5%), respectively. The mean follow up duration was 80 days. The mean differences in the $FEV_1$, FVC, TLC and RV were 0.27 L, 0.39 L, -0.69 L and -1.04 L, respectively, during the follow up periods. There was no correlation between the delta $FEV_1$ and delta RV values(r=0.072, p=0.738). Conclusion : To appropriately evaluate the lung function in patients with moderate to severe airflow limitations; serial lung volume measurements would be helpful.

A Study on the Effects of the Behavior Problems for the Demented Elderly upon the Stress among Family members (치매 노인의 문제행동이 가족스트레스에 미치는 영향)

  • 마정수;김초강
    • Korean Journal of Health Education and Promotion
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    • v.12 no.1
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    • pp.83-110
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    • 1995
  • The purpose of this study was to investigate the status of the problematic behavior for the demented elderly and the stress among family members, and the effects of the problematic behavior upon the stress in order to offer the basic data for the adult and the elderly health education about dementia. For this purpose, 70 families who were resident in Seoul and Inchon were surveyed by quetionnaires. This was carried out from 26 July, 1994 to 11 September, 1994. Datum was analysed by using SPSS\PC+ including percentage, mean, t - test, ANOVA, Pearson correlation. So, the results of this study were as follows: 1. In view of socia-demographic characteristics, female were 82.9%, and of the female daughters-in-law of the demented elderly were 44.9%. 40th years old were 32.9% and 88.6% wase married. The christian were 34.8%, those who graduated university 47.1%, and those who had a job 32.9%. 2. Of the demented elderly, female were 74.3%, 80 years old were 37.1%, and their average age was seventy-seven point one years old. 66.2% of the elderly has been lived alone and the christian were 27.5%. In addition, those who graduated elementary school were 66.5%. 3. Of the behavior problem for the demented elderly, Activities of the Daily Living(ADL) was the most severe problem. The 2nd was cognitive function problem, the 3th, change of personality, the 4th, emotional disturbance, and the last, misconduct behavior. 4. For the status of behavior problems, females were more severe than male, and 80th years elderly ware the most severe groups. The longer disease period was, the severe problematic behaviors were, and in 4-6 years of the disease period the status was the highest(p<0.05). Those who diagnosed the disease had more severe problems(p<0.001). 5. The orders of the stress among family members caring for the demented elderly in this study were as follows : 1. The deficiency of supporting network 2. Decrease of elderly's cognitive activities 3. Assistance of BADL(Basic Activities of Daily Living) 6. Elderly's abnormal behavior 5. Assistance of IADL(Instrumental Activities of Daily Living), 6. As for the status of the stress among family members, female respondants were higher than male. On the ages, 20th years' stress score were the highest. Daughters-in-law were stressed more than other family members. The longer the time of caring per day was, the highest the status of the stress(p<0.05), 7. Those who caring for female elderly and more than 80 years had more stressed. When the elderly was received the diagnosis, the family members were more stressed. On the disease period, 1-2 years was the highest and after 2 years the status of the stress was decreased and more than 6 years was the lowest(p<0.05). 8. Behavior problems of the demented elderly were closely associated to the stress for family members. Of the problems, change of personality was the most related factor(r = 0.6552). The factors of Basic Activities of the Daily Living(BADL) was most correlated on assistance of Basic Activities of Daily Living (BADL), emotional disturbance the assistance of IADL(Instrumental Activities of Daily Living). Change of personality was most related to the stress of the decrease of cognitive activities and elderly's abnormal behavior. The deficiency of supporting network was most related to misconduct behavior.

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Association of Plasma Eotaxin with Asthma Exacerbation and Severity (혈장 eotaxin과 천식의 급성악화 및 중증도와의 연관성)

  • Song, So-Hyang;Lee, So-Young;Kim, Chi-Hong;Moon, Hwa-Sik;Song, Jeong-Sup;Park, Sung-Hak
    • Tuberculosis and Respiratory Diseases
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    • v.51 no.1
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    • pp.35-43
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    • 2001
  • Background : The eosinophil chemotactic and activating effects of eotaxin and the known association of eosinophils with asthma suggest that eotaxin expression is increased during an asthma attack. This study was aimed to determine whether the plasma eotaxin levels are higher in patients during an asthma attack and to correlate the eotaxin levels with the disease activity, severity and response to therapy. Method : A case-control study of the plasma eotaxin levels was performed in 100 patients with exacerbated asthma and 48 age- and sex-matched subjects with stable asthma. Results : The plasma eotaxin levels were significantly higher in the 100 patients with exacerbated asthma($233{\pm}175\;pg/mL$) than in the 48 subjects with stable asthma($169{\pm}74\;pg/mL$). A trend toward higher eotaxin levels was observed in asthmatic subjects who were taking oral steroids ($332{\pm}225\;pg/mL$) than in those who were not ($214{\pm}159\;pg/mL$) and higher levels were found in those admitted to the hospital ($275{\pm}212\;pg/mL$) than in those discharged after receiving only emergency treatment ($190{\pm}115\;pg/mL$). The eotaxin levels inversely correlated with the $FEV_$ (r=-0.25, p<0.01). The eotaxin levels were higher in moderate persistent ($323{\pm}256\;pg/mL$) and severe persistent asthmatics ($276{\pm}170\;pg/mL$) than in mild intermittent asthmatics ($l60{\pm}60\;pg/mL$). Conclusion : Eotaxin expression is directly associated with asthma exacerbation, impaired pulmonary function and the disease severity.

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Correlation between Expiratory Increase of Lung Attenuation and Age and Smoking in the Subjects with Normal Inspiratory Low Dose CT and Pulmonary Function Test (저선량 흉부전산화단층촬영의 흡기 영상과 폐기능이 정상인 성인에서 호기 말 폐 감쇄도 증가 정도와 연령 및 흡연과의 연관성)

  • Kwon, Sung-Youn;Hwang, Yong-Il;Yoon, Ho-Il;Lee, Jae-Ho;Lee, Choon-Taek;Lee, Kyung Won
    • Tuberculosis and Respiratory Diseases
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    • v.65 no.6
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    • pp.457-463
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    • 2008
  • Background: The attenuation of the lung parenchyma increases on expiration as a consequence of decreased air in the lung. Expiratory CT scans have been used to show air trapping in patients with chronic airway disease and diffuse parenchymal disease and also in asymptomatic smokers. Although there have been several reports investigating the regional air trapping on a expiratory CT scan, there have been only a few reports evaluating the changes of whole lung attenuation with considering its clinical significance, and especially in healthy subjects. The purpose of this study was to evaluate the correlation of an expiratory increase of lung attenuation with age and smoking in healthy subjects. Methods: Asymptomatic subjects who underwent a low dose chest CT scan as part of a routine check-up and who showed normal spirometry and a normal inspiratory CT scan were recruited for this study. We excluded the subjects with significant regional air trapping seen on their expiratory CT scan. Lung attenuation was measured at 24 points of both the inspiratory and expiratory CT scans, respectively, for 100 subjects. The correlations between an expiratory increase of the lung attenuation and the amount of smoking, the patient's age and the results of spirometric test were assessed. Results: There were 87 men and 13 women included in this study. Their median age was 49.0 years old (range:25~71). Sixty current smokers, 24 ex-smokers and 16 non-smokers were included. As age increased, the expiratory increase of lung attenuation was reduced at every measuring points (r=-0.297~-0.487, Pearson correlation). The statistical significance was maintained after controlling for the effect of smoking. Smoking was associated with a reduction of the expiratory increase of lung attenuation. But the significance was reduced after controlling for the patient's age. The $FEV_1$, FVC, $FEV_1/FVC$ and $FEF_{25{\sim}75%}$ were not associated with an expiratory increase of lung attenuation. Conclusion: The expiratory increase of lung attenuation in subjects with a normal inspiratory CT scan was negatively correlated with age. It was also reduced in heavy smokers. It may reflect aging and the smoking related changes.

Functional MRI Study of Changes in Brain Activity by Manual Acupuncture at LI11 or ST36 (곡지, 족삼리 침자극이 뇌활성화에 미치는 영향에 대한 뇌기능적 자기공명영상을 이용한 연구)

  • Cho, Seung-Yeon;Jahng, Geon-Ho;Park, Seong-Uk;Jung, Woo-Sang;Moon, Sang-Kwan;Gho, Chang-Nam;Cho, Ki-Ho;Kim, Young-Suk;Bae, Hyung-Sup;Park, Jung-Mi
    • The Journal of Korean Medicine
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    • v.31 no.1
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    • pp.81-92
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    • 2010
  • Objectives: The objective of this study was to assess bra in activation and difference by LI11 or ST36 acupuncture stimulation using functional MRI (fMRI). Methods: A total of 10 healthy right-handed volunteers were studied. LI11 acupuncture and ST36 acupuncture stimulations were applied in order on the left. The block design paradigm of RARARA was used for the task, with R representing rest and A representing stimulation, and each period lasted 30 seconds. fMRI data were analyzed using SPM2. Results: The left LI11 acupuncture stimulation activated both sides of the inferior parietal lobule, the left side of the extra-nuclear, culmen and inferior semi-lunar lobules. On the right side, the nodule and midbrain regions were activated by the left LI11 acupuncture stimulation. The left ST36 acupuncture stimulation activated the right side of the superior frontal gyrus, middle frontal gyrus, superior parietal lobule, inferior semi-lunar lobule and pyramis. On the left side, the sub-gyral, middle temporal gyrus, fusiform gyrus, supramarginal gyrus, extra-nuclear, cingulate gyrus and fastigium regions were activated by the left ST36 acupuncture stimulation. Besides, both sides of the paracentral lobule, inferior parietal lobule, culmen, cerebellar tonsil and midbrain regions were activated. Conclusions: In conclusion, brain signal activation patterns according to acupoints were observed to differ, and ST36 acupuncture stimulation activated more regions than LI11. It is supposed that LI11 and ST36 acupuncture stimulations have an influence on motor function and sensory aphasia, and these stimulations thus represent potential for ocular motor dysfunction, discriminative touch or position sense disorder. Moreover, ST36 acupuncture stimulation activated the cingulate gyrus of the limbic system, so it seems to have an influence over autonomic functions.

ROC Analysis of Visual Assessments Made in Gated Blood Pool Scans of Patients with Coronary Artery Disease (관상동맥질환에서 심장풀 스캔의 육안적 평가에 대한 ROC 분석)

  • Lee, Kyun-Han;Choi, Yoon-Ho;Lee, Bum-Woo;Moon, Dae-Hyuk;Koong, Sung-Soo;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.23 no.2
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    • pp.175-181
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    • 1989
  • Visual assessment of regional wall motion abnormality (RWMA) by gated blood pol scan (GBPS) serves as an useful parameter in the diagnosis, functional evaluation, and follow up in various clinical settings, but are still subject to some inherent limitations. On important problem may be the interobserver as well as intraobsever variation that may well be present due to the subjective nature of the interpretations. This study was carried out to determine the reliability and reproducibility of visual assessments made in GBPSs, and to observe the degree to which the results would be influenced by observer variation. Fifty two patients with coronary heart disease had resting GBPS and contrast ventriculography within 4 days appall. Contrast ventriculography-showed normal wall motion in 6 patients and the remaining 46 had RWMA in one or more segments. The anterior and left anterolateral views of all 52 GBPSs were analyzed by three independent observers, who selected from 5 scales, their level of confidence that there was RWMA in that segment. Reciever operating characteristic (ROC) curves for each analysis was plotted and the area under the curve $(\theta)$ was used as a parameter representing each observer's performance in his interpretations. The findings of contrast ventriculographies were used as the standard for RWMA. The apical and inferoapical segments showed the best correlation with contrast ventriculography ($\theta=0.90-0.94$, 0.81-0.94, respectively), and the inferior wall showed the poorest correlation $(\theta=0.70-0.74)$. The interpretations of the inferior, septal, apical, and posteroinferior, segments showed no difference between the observers, but there was significantly better performance in assessment by observer A compared to that by B or C for the anterolateral segments ($\theta=0.87$, 0.78, 0.76, respectively. p<0.01 for A vs B, p<0.05 for A vs C), as well as when all segments were considered altogether ($\theta=0.88$, 0.83, 0.82, respectively. both p<0.05). This was also true for the infero-apical segment between A and C ($\theta=0.09$, 0.81, p<0.05). The intraobserver variation, however, did not appear significant, with only the inferior segment for observer B showing any significant difference when observer A and B repeated the analysis 10 days latter. There was no difference in assessing dyskinesia, with all observers showing a high performance ($\theta=0.98$, 0.87, 0.97, respectively). The visual assessment of left ventricular ejection fraction by all three observers correlated well with the calculated value from a semiautomated method (Spearman's r = 0.91, 0.83, 0.83. p<0.01, p<0.05, p < 0.05). The assessment of LV and RV size also correlated well between the three observers (Kendall's w = 0.80, 0.51, p<0.01 for both left and right ventricles). The above findings suggest that RWMA visually assessed by GBPS correlates well with that done by contrast ventriculography. And although the observer's experience or skill may influence the results in certain segments, visual analysis of GBPS may serve as a reliable and reproducible means for evaluating ventricular function.

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Detection of HCV-RNA by Reverse Transcription Polymerase Chain Reaction Using Biotinylated and Radioiodinated Primers (역전사 중합효소 연쇄반응(RT-PCR)에 의한 HCV-RNA의 검출 : Biotin 및 방사성옥소 표지 Primer로 구성된 Kit의 이용)

  • Ryu, Jin-Sook;Moon, Dae-Hyuk;Cheon, Jun-Hong;Chung, Yoon-Young;Park, Hung-Dong;Chung, Young-Hwa;Lee, Young-Sang
    • The Korean Journal of Nuclear Medicine
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    • v.28 no.2
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    • pp.220-226
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    • 1994
  • This study was performed to evaluate the clinical applicability of the reverse transcription polymerase chain reaction (RT-PCR ) kit of HCV-RNA using biotinylated and radioiodinated primers. Study subjects were 118 patients with positive anti-HCV. HCV-RNA in patient's serum was extracted by guanidium thiocyanate method. After first amplification, the product was reamplified by primers labelled with biotin and I-125. The final amplification product was defected by counting the radioactivity after incubation in avidin coated tubes. In 51 samples, the test was repeated for evaluation of reproducibility. This new method was also compared with conventional RT-PCR methods in 34 samples from patients with chronic liver disease. The results were as follows ; 1) HCV-RNA was positive in 85(97%)of 88 patients with chronic liver disease, and in 23 (73%) of 30 patients with normal liver function. 2) In comparison with conventional method, HCV-RNA was detected in 32(94%) of 34 patients with new method, whereas in 27(79%) of the same group with conventional method. 3) Repeated test with new method in 52 samples demonstrated 82% of concordant result. In conclusion, new method with biotinylated and radioiodinated primers was more sensitive than conventional method. However, great care must be taken for quality control because there were considerable interassay variation and possiblity of false positivity and false negativity.

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Clarithromycin Therapy for Scrub Typus (쯔쯔가무시(Tsutusgamushi)병에서 Clarithromycin의 치료 효과)

  • Kim, Soon;Jung, Eun Mi;Moon, Kyung Hyun;Yoe, Sung Yeob;Eum, Soo Jung;Lee, Joo Hyung;Jo, Sung Rae;Ma, Sang Hyuk
    • Pediatric Infection and Vaccine
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    • v.9 no.2
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    • pp.175-181
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    • 2002
  • Purpose : Scrub typhus(tsutsugamushi disease) is a febrile disease characterized by fever, rash, eschar, lymphadenopathy. Therapy with tetracycline(doxycycline) or chloramphenicol is currently recommended for the treatment for scrub typhus. But there are limitations in usage a tetracycline(doxycycline) for scrub typhus in the children. Recently, there was a report that azithromycin, a macrolide antibiotic was used for scrub typhus in pregnant woman successfully. So we evaluated the effectiveness of the Clarithromycin, other a macrolide antibiotic, for scrub typhus. Methods : Seven patients with scrub typhus at department of internal medicine and three patients with scrub typhus at department of pediatrics Masan Fatima Hospital were involved for this study. A serologic diagnosis for scrub typhus were performed by use of passive hemagglutination test. Clarithromycin(Abbott Laboratories, North Chicago, IL, USA) was administrated orally in a daily dose of 500 mg for adult patients and 15 mg/kg/bid/day for pediatric patients. Results : There were 7 cases of adult patients, varying from 28 to 76 years of age and 3 cases of pediatirc patients, varying from 4 to 7 years of age with scrub typhus. All of cases had fever, myalgia, headache, rash, eschar. Seven cases had positive passive hemagglutination test and eight cases had abnormal liver function. Mean duration for the removal of fever after medication was 1.3 day(1~2 days) and all cases were recovered without complications. Conclusion : Our results suggest that Clarithromycin therapy may be effective for scrub typhus.

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