• Title/Summary/Keyword: Sensitivity and specificity

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Added Value of Chemical Exchange-Dependent Saturation Transfer MRI for the Diagnosis of Dementia

  • Jang-Hoon Oh;Bo Guem Choi;Hak Young Rhee;Jin San Lee;Kyung Mi Lee;Soonchan Park;Ah Rang Cho;Chang-Woo Ryu;Key Chung Park;Eui Jong Kim;Geon-Ho Jahng
    • Korean Journal of Radiology
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    • v.22 no.5
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    • pp.770-781
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    • 2021
  • Objective: Chemical exchange-dependent saturation transfer (CEST) MRI is sensitive for detecting solid-like proteins and may detect changes in the levels of mobile proteins and peptides in tissues. The objective of this study was to evaluate the characteristics of chemical exchange proton pools using the CEST MRI technique in patients with dementia. Materials and Methods: Our institutional review board approved this cross-sectional prospective study and informed consent was obtained from all participants. This study included 41 subjects (19 with dementia and 22 without dementia). Complete CEST data of the brain were obtained using a three-dimensional gradient and spin-echo sequence to map CEST indices, such as amide, amine, hydroxyl, and magnetization transfer ratio asymmetry (MTRasym) values, using six-pool Lorentzian fitting. Statistical analyses of CEST indices were performed to evaluate group comparisons, their correlations with gray matter volume (GMV) and Mini-Mental State Examination (MMSE) scores, and receiver operating characteristic (ROC) curves. Results: Amine signals (0.029 for non-dementia, 0.046 for dementia, p = 0.011 at hippocampus) and MTRasym values at 3 ppm (0.748 for non-dementia, 1.138 for dementia, p = 0.022 at hippocampus), and 3.5 ppm (0.463 for non-dementia, 0.875 for dementia, p = 0.029 at hippocampus) were significantly higher in the dementia group than in the non-dementia group. Most CEST indices were not significantly correlated with GMV; however, except amide, most indices were significantly correlated with the MMSE scores. The classification power of most CEST indices was lower than that of GMV but adding one of the CEST indices in GMV improved the classification between the subject groups. The largest improvement was seen in the MTRasym values at 2 ppm in the anterior cingulate (area under the ROC curve = 0.981), with a sensitivity of 100 and a specificity of 90.91. Conclusion: CEST MRI potentially allows noninvasive image alterations in the Alzheimer's disease brain without injecting isotopes for monitoring different disease states and may provide a new imaging biomarker in the future.

Role of Myocardial Extracellular Volume Fraction Measured with Magnetic Resonance Imaging in the Prediction of Left Ventricular Functional Outcome after Revascularization of Chronic Total Occlusion of Coronary Arteries

  • Yinyin Chen;Xinde Zheng;Hang Jin;Shengming Deng;Daoyuan Ren;Andreas Greiser;Caixia Fu;Hongxiang Gao;Mengsu Zeng
    • Korean Journal of Radiology
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    • v.20 no.1
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    • pp.83-93
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    • 2019
  • Objective: The purpose of this study was to prospectively investigate the value of the myocardial extracellular volume fraction (ECV) in predicting myocardial functional outcome after revascularization of coronary chronic total occlusion (CTO). Materials and Methods: Thirty patients with CTO underwent cardiovascular magnetic resonance (CMR) before and 6 months after revascularization. Three baseline markers of functional outcome were evaluated in the dysfunctional segments assigned to the CTO vessels: ECV, transmural extent of infarction (TEI), and unenhanced rim thickness (RIM). At the global level, the ECV values of the whole myocardium with and without a hyperenhanced region (global and remote ECV) were respectively measured. Results: In per-segment analysis, ECV was superior to TEI and RIM in predicting functional recovery (area under receiver operating characteristic curve [AUC]: 0.86 vs. 0.75 and 0.73, all p values < 0.010), and it emerged as the only independent predictor of regional functional outcome (odds ratio [OR] = 0.83, 95% confidence interval [CI]: 0.77-0.89; p < 0.001) independent of collateral circulation. In per-patient analysis, global baseline ECV was indicative of ejection fraction (EF) at the follow-up examination (β = -0.61, p < 0.001) and changes in EF (β = -0.57, p = 0.001) in multivariate regression analysis. A patient with global baseline ECV less than 30.0% (AUC, 0.93; sensitivity 94%, specificity 80%) was more likely to demonstrate significant EF improvement (OR: 0.38; 95% CI: 0.17-0.85; p = 0.019). Conclusion: Extracellular volume fraction obtained by CMR may provide incremental value for the prediction of functional recovery both at the segmental and global levels in CTO patients, and may facilitate the identification of patients who can benefit from revascularization.

Evaluation of Clinical Efficacy of Korea Red Ginseng for Erectile Dysfunction by International Index of Erectile Function(IIEF) (국제 발기능측정설문지(IIEF)를 이용한 발기부전 환자에서의 홍삼 효능 평가)

  • 최형기;최영진
    • Journal of Ginseng Research
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    • v.25 no.3
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    • pp.112-117
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    • 2001
  • International index of erectile function (IIEF) has a high sensitivity and specificity for the evaluating treatment of erectile dysfunction. IIEF was used to evaluate on an international level the effectiveness of red ginseng on patients with erectile dysfunction and determine its possible development as a natural drug. 50 patients with erectile failure who were 20 years or older and without organic cause were randomly divided into two groups. Group 1(25 patients) received red ginseng 600mg three times a day and group 2 (25 patients) received placebo in the same fashion for 8 weeks. Each group was evaluated with IIEF at the start and end of therapy. Of the 50 patients 47 (group 1 24, group 2 23) who completed the 8 week therapy were evaluated. The mean age and symptom duration of the patients was 45.7$\pm$8.7 (27-68) and 6.2$\pm$5.6(1-29) years, respectively. Patient age, symptom duration. marriage status, marriage duration, partner age were not statistic significance between the two groups (p>0.05). Blood chemistry, urinalysis, and hormonal assay did not reveal difference between the two groups. primary efficacy (erectile rigidity and its maintenance) and all domains in secondary efficacy were significantly better after therapy in group 1 compared to those of group 2 (p<0.05) except for frequency of sexual desire, degree of sexual desire, and frequency of intercourse trial (p>0.05). Group 1 patients were significantly more satisfied after treatment compared to group 2 patients with 58.3% (14/24)and 26.1%(6/23) satisfaction rates, respectively. There were no adverse reactions or complications with ginseng adiminstration. Further study into the effects of saponin and ginsenoside that are the main substances in ginseng for erectile dysfunction is needed. In addition, its possible additive effect with ginseng and sildenafil should be elucidated in the future.

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A Recombinant $Plasmodium$ $vivax$ Apical Membrane Antigen-1 to Detect Human Infection in Iran

  • Haghi, Afsaneh Motevalli;Khoramizade, Mohammad Reza;Nateghpour, Mehdi;Mohebali, Mehdi;Edrissian, Gholam Hossein;Eshraghian, Mohammad Reza;Sepehrizadeh, Zargham
    • Parasites, Hosts and Diseases
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    • v.50 no.1
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    • pp.15-21
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    • 2012
  • In Iran, $Plasmodium$ $vivax$ is responsible for more than 80% of the infected cases of malaria per year. Control interventions for vivax malaria in humans rely mainly on developed diagnostic methods. Recombinant $P.$ $vivax$ apical membrane antigen-1 (rPvAMA-1) has been reported to achieve designing rapid, sensitive, and specific molecular diagnosis. This study aimed to perform isolation and expression of a rPvAMA-1, derived from Iranian patients residing in an endemic area. Then, the diagnostic efficiency of the characterized Iranian PvAMA-1 was assessed using an indirect ELISA method. For this purpose, a partial region of AMA-1 gene was amplified, cloned, and expressed in pET32a plasmid. The recombinant $His-tagged$ protein was purified and used to coat the ELISA plate. Antibody detection was assessed by indirect ELISA using rPvAMA-1. The validity of the ELISA method for detection of anti-$P.$ $vivax$ antibodies in the field was compared to light microscopy on 84 confirmed $P.$ $vivax$ patients and compared to 84 non-$P.$ $vivax$ infected individuals. The ELISA cut-off value was calculated as the mean+2SD of OD values of the people living in malaria endemic areas from a south part of Iran. We found a cut-off point of OD=0.311 that showed the best correlation between the sera confirmed with $P.$ $vivax$ infection and healthy control sera. A sensitivity of 81.0% and specificity of 84.5% were found at this cut off titer. A good degree of statistical agreement was found between ELISA using rPvAMA-1 and light microscopy (0.827) by Kappa analysis.

Evaluation of the antibodies against Pseudomonas tolaasii and Pseudomonas agarici for Immunoassays and Its Application (항 Pseudomonas tolaasii 및 Pseudomonas agarici 항체의 면역측정법을 위한 평가와 그 이용)

  • Jeon, Nak-Beom;Lee, Hyang-Burm;Shon, Dong-Hwa;Yu, Seung Hun
    • Research in Plant Disease
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    • v.9 no.2
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    • pp.94-98
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    • 2003
  • To produce antibodies against Pseudomonas tolaasii and P. agarici, lyophilized P. tolaasii and P. agarici ($5{\times}10^7$ cfu/ml) and Freund, s adjuvant were immunized into rabbits 4 times. The specificity and sensitivity of the antibodies were evaluated by immunodiffusion test and indirect enzyme-linked immunosorbent assay (id ELISA). The ${\alpha}$-P. tolaasii antibody was very specific only against P. tolaasii, while ${\alpha}$-P. agarici antibody was not specific and showed a high cross reactivity toward P. tolaasii with detection limit concentration of $2{\times}10^3$ cfu/ml. However, the cross reactivities of ${\alpha}$-P. agarici antibody toward the related species including P. reactans were very low. Our results showed that ${\alpha}$-P. tolaasii and ${\alpha}$-P. agarici antibodies against P. tolaasii and P. agarici, respectively, might be useful for rapid and simple detection of the causal agents of bacterial brown and yellow blotches in cultivated oyster mushrooms.

Pre-treatment Metabolic Tumor Volume and Total Lesion Glycolysis are Useful Prognostic Factors for Esophageal Squamous Cell Cancer Patients

  • Li, Yi-Min;Lin, Qin;Zhao, Long;Wang, Li-Chen;Sun, Long;Dai, Ming-Ming;Luo, Zuo-Ming;Zheng, Hua;Wu, Hua
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1369-1373
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    • 2014
  • Objectives: To study application of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) with $^{18}F$-FDG PET/CT for predicting prognosis of esophageal squamous cell cancer (ESC) patients. Methods: Eighty-six patients with ESC staged from I to IV were prospectively enrolled. Cisplatin-based chemoradiotherapy (CCRT) or palliative chemoradiotherapy were the main treatment methods and none received surgery. $^{18}F$-FDG PET/CT scans were performed before the treatment. SUVmax, MTV, and TLG were measured for the primary esophageal lesion and regional lymph nodes. Receiver operating characteristic curves (ROCs) were generated to calculate the P value of the predictive ability and the optimal threshold. Results: MTV and TLG proved to be good indexes in the prediction of outcome for the ESC patients. An MTV value of 15.6 ml and a TLG value of 183.5 were optimal threshold to predict the overall survival (OS). The areas under the curve (AUC) for MTV and TLG were 0.74 and 0.70, respectively. Kaplan-Meier analysis showed an MTV less than 15.6 ml and a TLG less than 183.5 to indicate good media survival time (p value <0.05). In the stage III-IV patient group, MTV could better predict the OS (P < 0.001), with a sensitivity and specificity of 0.80 and 0.67, respectively. Conclusions: Pre-treatment MTV and TLG are useful prognostic factors in nonsurgical ESC.

Gene Expression Biodosimetry: Quantitative Assessment of Radiation Dose with Total Body Exposure of Rats

  • Saberi, Alihossein;Khodamoradi, Ehsan;Birgani, Mohammad Javad Tahmasebi;Makvandi, Manoochehr
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8553-8557
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    • 2016
  • Background: Accurate dose assessment and correct identification of irradiated from non-irradiated people are goals of biological dosimetry in radiation accidents. Objectives: Changes in the FDXR and the RAD51 gene expression (GE) levels were here analyzed in response to total body exposure (TBE) to a 6 MV x-ray beam in rats. We determined the accuracy for absolute quantification of GE to predict the dose at 24 hours. Materials and Methods: For this in vivo experimental study, using simple randomized sampling, peripheral blood samples were collected from a total of 20 Wistar rats at 24 hours following exposure of total body to 6 MV X-ray beam energy with doses (0.2, 0.5, 2 and 4 Gy) for TBE in Linac Varian 2100C/D (Varian, USA) in Golestan Hospital, in Ahvaz, Iran. Also, 9 rats was irradiated with a 6MV X-ray beam at doses of 1, 2, 3 Gy in 6MV energy as a validation group. A sham group was also included. After RNA extraction and DNA synthesis, GE changes were measured by the QRT-PCR technique and an absolute quantification strategy by taqman methodology in peripheral blood from rats. ROC analysis was used to distinguish irradiated from non-irradiated samples (qualitative dose assessment) at a dose of 2 Gy. Results: The best fits for mean of responses were polynomial equations with a R2 of 0.98 and 0.90 (for FDXR and RAD51 dose response curves, respectively). Dose response of the FDXR gene produced a better mean dose estimation of irradiated "validation" samples compared to the RAD51 gene at doses of 1, 2 and 3 Gy. FDXR gene expression separated the irradiated rats from controls with a sensitivity, specificity and accuracy of 87.5%, 83.5% and 81.3%, respectively, 24 hours after dose of 2 Gy. These values were significantly (p<0.05) higher than the 75%, 75% and 75%, respectively, obtained using gene expression of RAD51 analysis at a dose of 2 Gy. Conclusions: Collectively, these data suggest that absolute quantification by gel purified quantitative RT-PCR can be used to measure the mRNA copies for GE biodosimetry studies at comparable accuracy to similar methods. In the case of TBE with 6MV energy, FDXR gene expression analysis is more precise than that with RAD51 for quantitative and qualitative dose assessment.

Macroscopic Serosal Invasion in Advanced Gastric Cancer (진행성 위암에서 육안적 장막침윤의 의의)

  • Yun, Woo-Sung;Kim, Tae-Bong;Yu, Wan-Sik
    • Journal of Gastric Cancer
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    • v.6 no.2
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    • pp.84-90
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    • 2006
  • Purpose: The macroscopic findings of tumors are not always identical with the microscopic findings. This study investigated the oncologic implications of macroscopic serosal invasion in advanced gastric cancer to find out how to improve the accuracy for the depth of invasion assessed by the surgeon during an operation. Materials and Methods: The medical records of 789 patients with advanced gastric cancer who underwent a gastrectomy at Kyungpook National University Hospital between 1995 and 1999 were reviewed. The prognoses and the recurrence patterns were analyzed according to macroscopic serosal invasion and microscopic serosal invasion, and the clinico-pathological factors of cT3/ss cancers were compared with those of cT3/se cancers. Results: Difference of survival rates according to macroscopic serosal invasion and microscopic serosal invasion revealed statistically significant. Recurrence rates were similar in patients with macroscopic and microscopic serosal invasion (42.2% and 41.4%, respectively). Peritoneal recurrence rates were also similar (19.8% and 21.9%, respectively). The sensitivity and the specificity of macroscopic assessment of serosal invasion were 70.3% and 77.8%, respectively, On univariate and multivariate analyses, Borrmann type I/II cancers and the absence of distant metastases revealed the risk factors for overestimating of serosal invasion. Conclusion: Macroscopic serosal invasion assessed by a surgeon intraoperatively can be used to give a prognosis and to predict the recurrence pattern precisely, although there is a risk for overestimation when the tumor is a Borrmann type I/II cancer or the tumor has no distant metastases. (J Korean Gastric Cancer Assoc 2006;6:84-90)

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What will be the Proper Criteria for Impaired Fasting Glucose for Korean Men? - Based on Medical Screening Data from a General Hospital - (공복혈당장애의 기준 하한치에 관한 코호트연구 - 일개병원 종합건강자료를 중심으로 -)

  • Ryu, Seung-Ho;Kim, Dong-Il;Suh, Byung-Seong;Kim, Woon-Sool;Chang, Yoo-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.2
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    • pp.203-207
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    • 2005
  • Objectives: Recently, the American Diabetes Association (ADA) redefined the criteria of prediabetes, which has lowered the diagnostic level of fasting plasma glucose (FPG) from 110 to 125 mg/dl, down to levels between 100 to 125mg/dl. The purpose of this study was to determine the predictive cutoff level of FPG as a risk for the development of diabetes mellitus in Korean men. Methods: A retrospective cohort study was conducted on 11,423 (64.5%) out of 17,696 males $\leq$30 years of age, and who met the FPG of $\leq$125 mg/dl and hemoglobin A1c of $\leq$ 6.4% criteria, without a history of diabetes, and who were enrolled at the screening center of a certain university hospital between January and December 1999. The subjects were followed from January 1999 to December 2002 (mean follow-up duration; 2.3(${\pm}0.7$) years). They were classified as normal (FPG <100mg/dl), high glucose (FPG $\geq$100mg/dl and <110mg/dl) and impaired fasting glucose (FPG $\geq$110mg/dl and $\leq$125mg/dl) on the basis of their fasting plasma glucose level measured in 1999. We compared the incidence of diabetes between the 3 groups by performing Cox proportional hazards model and used receiver operating characteristic analyses of the FPG level, in order to estimate the optimal cut-off values as predictors of incident diabetes. Results: At the baseline, most of the study subjects were in age in their 30s to 40s (mean age, 41.8(${\pm}7.1$) year). The incidence of diabetes mellitus in this study was 1.19 per 1,000 person-years (95% CI=0.68-1.79), which was much lower than the results of a community-based study that was 5.01 per 1,000 person-years. The relative risks of incident diabetes in the high glucose and impaired fasting glucose groups, compared with the normal glucose group, were 10.3 (95% CI=2.58-41.2) and 95.2 (95% CI= 29.3-309.1), respectively. After adjustment for age, body mass index, and log triglyceride, a FPG greater than 100mg/dl remained significant predictors of incident diabetes. Using the receiver operating characteristic (ROC) curve, the optimal cutoff level of FPG as a predictor of incident diabetes was 97.5 mg/dl, with a sensitivity and a specificity of 81.0% and 86.0%, respectively. Conclusion: These results suggest that lowering the criteria of impaired fasting glucose is needed in Korean male adults. Future studies on community-based populations, including women, will be required to determine the optimal cutoff level of FPG as a predictor of incident diabetes.

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
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    • v.17 no.2
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    • pp.72-77
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    • 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.

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