• Title/Summary/Keyword: test specificity

Search Result 896, Processing Time 0.033 seconds

Performance Evaluation of In Vitro Diagnostic Reagents for Mycobacterium tuberculosis and Non-tuberculous Mycobacteria by FDA Approval (미국 FDA 허가사례를 통해 본 결핵균 및 비결핵 항산균 체외진단용 시약의 성능평가)

  • Kim, Yeun;Park, Sunyoung;Kim, Jungho;Chang, Yunhee;Ha, Sunmok;Choi, Yeonim;Lee, Hyeyoung
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.50 no.1
    • /
    • pp.20-28
    • /
    • 2018
  • Tuberculosis (TB) is a bacterial infection disease caused by members of the species Mycobacterium tuberculosis (MTB) complex. Approximately one third of the world's population is infected with TB. In Korea, approximately 40,000 new patients are identified each year. Moreover, infections from non-tuberculous mycobacteria (NTM) have also increased. In the diagnosis of TB and NTM, traditional bacterial cultures are required for 3 to 4 weeks. Therefore, rapid and accurate diagnostic tests for TB and NTM are needed. To distinguish between TB and NTM, a range of diagnostic methods have been developed worldwide. In vitro diagnostic assays are constantly being developed to meet the increasing need for the rapid and accurate identification for TB and NTM. On the other hand, the performance evaluations of in vitro diagnostic reagents for TB and NTM are lacking. Recently, the Korea Food and Drug Administration (KFDA) issued a guideline for in vitro diagnostic reagents for MTB and NTM. Here, this study analyzed the performance of currently developed in vitro diagnostic reagents for TB and NTM in the US FDA. This analysis of US FDA approved molecular assays could serve as a useful reference for an evaluation of the reagent performance of TB and NTM.

Evaluation of Automated ESR Measuring System, $SEDIsystem^{TM}$ ($SEDIsystem^{TM}$을 이용한 적혈구 침강속도 측정의 평가)

  • Lee, Jung-Ee;Kim, Kyung-Dong;Lee, Chae-Hoon;Kim, Chung-Sook
    • Journal of Yeungnam Medical Science
    • /
    • v.13 no.1
    • /
    • pp.110-115
    • /
    • 1996
  • The ESR is one of the oldest laboratory test still in use. Although it lacks specificity in diagnosis, it can be effective for monitoring disease activity and following-up. The Westergren method is used for reference method, however coefficient of variation has been described 0.8% to 22.9% according to the literature. Since the ESR was invented in 1921, measurement technique has developed and automated measurement is introduced. We analyzed one hundred forty-three patient samples using $SEDIsystem^{TM}$ automated ESR measuring system and compared with modified Westergren and Wintrobe methods. Comparison between $SEDIsystem^{TM}$ and modified Westergren for ESR measurement yields the following regression equation; y = 0.863x - 1.69 (r=0.830), $SEDIsystem^{TM}$ and Wintrobe y = 1.14x - 14.7 (r=0.789), respectively. We repeated measurement to evaluate reliability, results are not significant in statistically. In conclusion, $SEDIsystem^{TM}$ automated ESR measurement correlated with modified Westergren and Wintrobe methods, reveal reliable results after 4 hours and can report rapidly for large samples. Thus, these results indicate that $SEDIsystem^{TM}$ automated ESR measurement may be useful tool for clinical practice.

  • PDF

Purification and Characterization of Phytase from Bacillus subtilis (Bacillus subtilis가 생산하는 Phytase의 정제 및 특성)

  • Koh Hyun-Jung;Chu In-Ho;Chung Kun-Sub
    • Microbiology and Biotechnology Letters
    • /
    • v.34 no.1
    • /
    • pp.40-46
    • /
    • 2006
  • A bacterial strain producing high level of a phytase was isolated from cattle feces and identified as Bacillus subtilis, and designated as Bacillus sp. CF 5-26. The production of the phytase from Bacillus sp. CF 5-26 reached the highest level after 72 hours at $37^{\circ}C$. The optimum condition of the media for the production of phytase was 10% rice bran extract, 0.1% whey protein powder, $0.01%\;CaCl_{2},\;0.01%\;KH_{2}PO_4$. The phytase was purified 20.3 folds with ethanol precipitation, Sephadex G-100, CM Sepharose CL-6B and Sephacryl S-100-HR column chromatography. The molecular weight of the purified enzyme was estimated to be 66 kDa on SDS-polyacrylamide gel electrophoresis. The purified phytase activity was stable up pH 5.0, 7.0, 11.0 and the remaining activity was 50% when it was treated at $100^{\circ}C$ for 1 hour. The substrate specificity of phytase was most active against sodium phytate and inositol polyphosphate compound. And the phytase hydrolysed tripolyphosphate and pyrophosphate a little. The Km value for the sodium phytate was 0.64 mM and the Vmax value was $4.41\;{\mu}mol/min$.

Production of a Specific Yolk Antibody against Enterotoxigenic E. coli F41 Fimbrial Antigen (장독성대장균 F41 섬모항원에 대한 특이난황항체 생산)

  • Shin, S.O.;Kim, J.W.
    • Journal of Animal Science and Technology
    • /
    • v.44 no.5
    • /
    • pp.633-642
    • /
    • 2002
  • Enteric colibacillosis has economically become an important disease of young animals as a result of increasing intensification of farrowing management. The objective of this experiment is to isolate fimbrial antigen from enterotoxigenic E. coli F41, to develop specific polyclonal IgY which can effectively neutralize or reduce the proliferation of pathogens in feed or living animal system, and to apply IgY technologies to animal industry. The results obtained were as follows: The molecular weight of the purified F41 antigen was 29,500 dalton on sodium dodecyl sulfate-polyacrylamide gels. Fimbrial antigen was confirmed by the western blot method. It was observed that after immunization the level of serum antibody titer of laying hen was shown in two weeks and gradually increased. The antibody titer in egg yolk appeared two weeks after it was shown in serum antibody. The titers of egg yolk antibody were gradually increased to the maximum level of 320,000 (antigen 50${\mu}g$/$m\ell$), 450,000 (antigen 200${\mu}g$/$m\ell$), and 320,000 (antigen 600${\mu}g$/$m\ell$). According to the results of specificity test by ELISA, the anti-F41 antibodies from chicken serum and egg yolk reacted only with ETEC F41 antigen. There was no cross reaction with other ETEC strains (K88, K99, and 987P). In vitro condition, as a result of antigen binding ability of yolk antibodies, bacterial concentration was rapidly decreased to $10^5$ CFU/$m\ell$ from $10^9$ CFU/$m\ell$ when 2${\sim}$4 mg/$m\ell$ of freeze dried WSF (water soluble fraction) was added.

Evaluation of the Liver Cancer Diagnosis Function of PET-MRI Based on Decision Matrix Analysis (판정행렬분석을 통한 PET-MRI의 간암 진단성능 평가)

  • Kim, Jin-Eui;Kim, Jung-Soo;Choi, Nam-Gil;Han, Jae-Bok
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.11
    • /
    • pp.50-59
    • /
    • 2017
  • To evaluate the capability of integrated PET-MRI, which has recently been utilized in the clinical practices, on the diagnosis of liver cancer, its utility was assessed by $2{\times}2$ decision matrix. The numbers of abnormal and normal decisions on the liver cancer were 98 and 51 cases, respectively, upon PET-MRI scan results of the subjects, and the numbers of positive and negative decisions were 103 and 62, respectively, upon cytopathologic results. Out of the two tests, 95 cases were shown as true-positive and 3 were false positive, while 62 were true negative and 5 were false negative. Upon the results of PET-MRI test, its sensitivity, specificity, false negative rate, and false positive rate were 95.00%, 95.38%, 0.05%, and 95.15%, respectively. Therefore, it is considered to have the high potential to use the determination of the stage before the surgery, detections of recurrence and remote metastasis, assessment of uncertain remote lymph node metastasis, and so on in the diagnosis of the liver cancer, and also for the clinical utility of PET-MRI to be sufficient by integrated diagnosis and follow up scan with pathological studies.

Clinical Usefulness of Fatigue Severity Scale for Patients with Fatigue, and Anxiety or Depression (피로와 우울.불안증 환자에서 Fatigue Severity Scale의 임상적 유용성)

  • Chung, Koo-In;Song, Chan-Hee
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.9 no.2
    • /
    • pp.164-173
    • /
    • 2001
  • Objectives : Fatigue is a common symptom in primary medical care and has nonspecific and highly subjective features. So it has been difficult to define and measure fatigue, especially those present without any organic diseases. This study was conducted to evaluate the validity of the Fatigue severity scale(FSS) in patients with persistent fatigue who were free of any organic diseases or psychiatric disorders of depression or anxiety. Methods : Subjects consisted of 45 controls, 44 fatigued patients and 43 psychiatric patients with depression or anxiety. They all completed the fatigue severity, modified Bepsi stress, and Hospital anxiety and depression scales. Chalder fatigue scale was administrated randomly in 30 of them. Data were analyzed for reliability and validity of the FSS. Results: Cronbach's a coeffient of FSS was 0.929, and the Pearson correlation coefficient for test-retest was 0.916(p<0.01). ANCOVA for discriminant validity revealed that there were significant differences in mean FSS values among the three groups. The fatigue group had significantly higher FSS value than the other two groups. The psychiatric group also had significantly higher FSS value than the control group. The Pearson correlation coefficient for convergent validity by comparing FSS with Chalder fatigue scale was 0.782(p<0.01). Using FSS index 3.22 as the cut-off point, sensitivity was 84.1% and specificity was 85.7% for the fatigue and control groups, respectively. Conclusion : Results suggested the clinical application of the FSS to be a useful measurement for distinguishing fatigue between patients with physiologic fatigue and psychiatric patients with depression or anxiety.

  • PDF

Acid Steatocrit in Korean Infants (한국 영아의 Acid Steatocrit에 대한 연구)

  • Park, Ji He;Chung, So Chung;Song, Jun Soup;Kim, Kyo Sun
    • Clinical and Experimental Pediatrics
    • /
    • v.45 no.3
    • /
    • pp.320-324
    • /
    • 2002
  • Purpose : Steatorrhea tests have been developed using various methods. Acid steatocrit is a simple method to detect steatorrhea and has very high sensitivity and specificity. This present study was designed to establish the normal values of acid steatocrit in Korean infants and to find the difference according to the various feeding methods. Methods : Acid steatocrit tests were conducted on 128 infants who were under 12 months of age and who had non-specific gastrointestinal diseases between May 1998 and April 2001. The results were classified into neonatal ages(79 neonates), 1-6 months(28 infants), 7-12 months(21 infants). This included formula-fed(46 neonates) and human milk-fed(33 neonates), 1-6 months formula-fed (18 infants) and human milk-fed(10 infants), 7-12 months formula-fed(11 infants) and human milk-fed(10 infants). Results : The acid steatocrit values decreased by infant age in months. Acid steatocrit values decreased much more after 7 months of ages. The acid steatocrit values of human milk-fed infants were significantly lower than those of formula-fed infants. Conclusion : Our study confirms that a physiologic steatorrhea was found in the infant period and decreases by infant age of months. The acid steatocrit test might be useful for the evaluation of gastrointestinal milk fat malabsorption disorders and therapeutic effects.

Study to Protocol of PET Acquisition Time for Patient Body Type in PET/CT (PET/CT 검사에서 환자체형에 따른 적정검사 프로토콜에 관한 고찰)

  • Cho, Seok Won;Ham, Joon-Chul;Kang, Chun Goo;Bahn, Young Kag;Lee, Seung Jae;Lim, Han Sang;Lee, Chang-Ho;Park, Hoon-Hee
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.17 no.2
    • /
    • pp.72-77
    • /
    • 2013
  • Purpose: Whole-body PET using radiopharmaceutical is one of the imaging study methods for physiological changes of body. High specificity of the PET-CT examination is used to detect an early stages of cancer and metastatic cancer by imaging a physiological changes. During the imaging process, PET image has been characterized by a relatively low image quality due to its low sensitivity and the acquisition of random and scatter coincidences as well as patients figure. Therefore, the image quality as the changes of the acquisition times of patient weight was evaluated in this study. Materials and Methods: Thirty patients who presented to our hospital were enrolled. They were divided to normal, overweight, and obese group using BMI index, respectively. The patients with a liver disease and diabetes were excluded. $^{18}F-FDG$ was administered to the patients as 5.2 MBq per kg. After an hour from an injection, image acquisition was obtained as List mode in a part of liver in 1 bed. SNR (signal-to-noise ratio) of each groups acquisition times were confirmed from the calculated radiation counts and random fractions. The statistical significance of three groups was confirmed through one-way ANOVA test. On the basis of the counts of 2 minutes on normal group, the SNR of overweight group and obese group were compared. Results: The SNR were increased with loger aquisition time in 3 groups. In the condition of same acquisition time, the SNR had a statistical significance (P<0.05). The SNR were decreased to the normal, overweight, and obese, respectively. Liver activity had no significance difference on each group and RF had the significance differences (P<0.05). On the basis of the counts of 2 minutes on normal group, there were no statistical significance in a three minute acquisitions of overweight group and two minute acquisitions of obese group (P=0.150). Conclusion: In this study, the administrated amount of radiation dose did not adjust as the change of the patients weight. Increasing the acquisition time when the administration of the same amount of dose was able to get a good result of SNR. When the Based 2 minute on normal group, if overweight and obese case the increased acquisition time of 3 minute was able to obtain a similar SNR. On the basis of the normal group, the acquisition times of overweight and obese group were increased to 3 minutes per bed and the SNR were similar to the normal group.

  • PDF

The Preoperative Diagnosis of Thyroid Cancer in $^{18}F$-FDG PET/CT Dual Time Imaging of SUV and Evaluation of Radioactivity Measurement (갑상선암 수술 전 진단목적의 $^{18}F$-FDG PET/CT Dual Time Point영상에서 SUV값과 방사능 농도 측정법의 유용성 평가)

  • Lee, Hyun-Kuk;Khang, Hyun Soo;Yang, Seoung-Oh;Han, Man-Seok
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.16 no.2
    • /
    • pp.99-105
    • /
    • 2012
  • Purpose : This study is designed to compare two parameters reflecting $^{18}F$-FDG uptake, SUV and radioactivity, for diagnosis of thyroid cancer in dual time $^{18}F$-FDG PET/CT imaging and to find which parameter is more useful to decide whether the tumor is malignant or not. Materials and Methods : We performed retrospective study for 40 patients. All patients are diagnosed as primary thyroid cancer and examined $^{18}F$-FDG PET/CT. First, we got the dispersion of scattering beam of neck and lung apex to set a background and compared each dispersion, mean value, standard deviation of maxSUV and radioactivity. Also, mean maxSUV, ${\Delta}maxSUV$, ${\Delta}maxBq$/ml(%) and radioactivity between groups according to lesion's size based on biopsy are compared with independent-sample t-test. Results : the values that were from maxSUV and radioactivity measurement technique were compensated and calculated to practical values for mean comparison and patients were divided to two groups based on tumor size, Group1 ($size{\leq}1$ cm, n=21), Group2 (size>1 cm, n=19) for accurate comparison. In Group1, maxSUV (semi-quantitative analysis) was increased from $5.64{\pm}5.85$ (1.89~17.84) at first image to $5.90{\pm}5.01$ (1.95~18.22) at second image and radioactivity (Bq/ml) (quantitative analysis) showed similar increase from $5.93{\pm}6.38$ (2.50~16.75) at first image to $6.01{\pm}5.25$ (2.66~16.58) at second image. In Group2, TFmaxSUV was $10.54{\pm}14.36$ (2.54~33.89) in true first image, TSmaxSUV was $9.85{\pm}12.88$ (2.62~26.20) in true second image separately. The maxSUV showed a significant difference in the mean comparison between the two groups (p=0.035) But, mean radioactivity (Bq/ml) was $5.93{\pm}6.38$ (4.81~40.99) in true first image, $6.01{\pm}5.25$ (4.51~36.93) in true second image and didn't show a significant difference statistically (p=0.126) Conclusion : In diagnosis of thyroid tumor, SUV and radioactivity depending on $^{18}F$-FDG uptake showed high similarity with coefficient of determination (R2=0.939) and malignant evaluation results using dual time also showed similar aspect. Radioactivity for evaluation of malignant tumor didn't show better specificity or sensitivity than maxSUV.

  • PDF

Studies on the Immunoblot Characterization of Clonorchis sinensis Worm Antigens at Carly Development Stages (Immunoblot 법을 이용한 간흡충항원(肝吸蟲抗原)의 발육단계별(發育段階別) 항원성분석(抗原性分析)에 관한 연구(硏究))

  • Lee, Seon-Kyung;Joo, Kyoung-Hwan;Chung, Myung-Sook;Rim, Han-Jong
    • Journal of agricultural medicine and community health
    • /
    • v.16 no.1
    • /
    • pp.61-69
    • /
    • 1991
  • Serodiagnosis of Clonorchis sinensis infections will probably be a first choice tool for screening of clonorchiasis in a future because of increasing difficulties in collection and examination of stools. The sensitive test such as ELISA can he used effectively. However there are some limitations in serological diagnosis for the detection of serum antibody. One of the major problems is the non-specificity of the antigens which produce cross reaction with other helminthic infection sera. To solve this problem. many investigators have tried to purify the antigens used. In this study, we determined the antigenic profile of the crude saline extract antigen of C. sinensis at early developmental stage based on SDS-PAGE and immunoblotting techniques for the purpose of understanding the nature of C. sinensis worm antigen The following results were obtained : 1) The SDS-PAGE showed many protein hands ranging from 10Kd to 91Kd relative molecular weight. Among them, 66, 46, 40, 33, 27, 24, 16, 14 and 10Kd bands were observed as a principle bands. The protein components of C. sinensis changed chronologically during their early developmental period. 44Kd band was stained unclearly in antigen of 2 weeks worm, but changed to concentrated state in antigen of 5 weeks worm. 35Kd band was found in antigen of 2 weeks worm, however this band was disappeared in antigen of 5 weeks worm. 22Kd band also lost its staining property gradually. 2) In spite of differences in antigenic profile, there was no differences in the data obtained by microplate ELISA using each antigen preparation. Absorbance value began to rise in between 2 to 3 weeks after infection. 3) By EITB. serum antibody recognized major protein bands with molecular weight of 91, 85, 63, 46, 40, 33, 24, 14 and 10Kd hand respectively. Among them 66, 33, 17 and 14Kd bands were observed as non-specific band because they reacted even in normal control sera. Generally, gradual increase of positive reactions were observed as the infection period of C. sinensis was prolonged. In other hand, the reaction of 10Kd hand did not occurred when 26th week sera was tested. 4) The positive reactions using antigens of 2 weeks worm, especially on 40 and 24Kd bands, were most strong and sharply demarcated compared to those of 3~5 weeks worm antigen.

  • PDF