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Sample records for false positive immunoglobulin

  1. False positive immunoglobulin m antibody to cytomegalovirus in child with infectious mononucleosis caused by epstein-barr virus infection.

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    Park, Jee Min; Shin, Jae Il; Lee, Jae Seung; Jang, Young Ho; Kim, Sung Hun; Lee, Kang Hyuk; Lee, Chang Hoon

    2009-10-31

    A 16-month-old boy was admitted because of cough that had lasted for 10 days. The patient showed severe hepatomegaly incidentally, and dual positivity of Immunoglobulin (Ig) M to Epstein-Barr virus (EBV) viral capsid antigen (VCA) and cytomegalovirus (CMV). On the basis of seroconversion to Epstein-Barr nuclear antigen (EBNA) Ig G positivity and reduced CMV Ig M titer with persistently negative CMV Ig G, a definite diagnosis of EBV-induced infectious mononucleosis was established 1 year 2 month later.

  2. A mode of error: Immunoglobulin binding protein (a subset of anti-citrullinated proteins can cause false positive tuberculosis test results in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Maria Greenwald

    2017-12-01

    Full Text Available Citrullinated Immunoglobulin Binding Protein (BiP is a newly described autoimmune target in rheumatoid arthritis (RA, one of many cyclic citrullinated peptides(CCP or ACPA. BiP is over-expressed in RA patients causing T cell expansion and increased interferon levels during incubation for the QuantiFERON-Gold tuberculosis test (QFT-G TB. The QFT-G TB has never been validated where interferon is increased by underlying disease, as for example RA.Of ACPA-positive RA patients (n = 126, we found a 13% false-positive TB test rate by QFT-G TB. Despite subsequent biologic therapy for 3 years of all 126 RA patients, none showed evidence of TB without INH. Most of the false-positive RA patients after treatment with biologic therapy reverted to a negative QFT-G test. False TB tests correlated with ACPA level (p < 0.02.Three healthy women without arthritis or TB exposure had negative QFT-G TB. In vitro, all three tested positive every time for TB correlating to the dose of BiP or anti-BiP added, at 2 ug/ml, 5 ug/ml, 10 ug/ml, and 20 ug/ml.BiP naturally found in the majority of ACPA-positive RA patients can result in a false positive QFT-G TB. Subsequent undertreatment of RA, if biologic therapy is withheld, and overtreatment of presumed latent TB may harm patients. Keywords: Tuberculosis, IGRA, Rheumatoid arthritis, Interferon, Anti-citrullinated peptide antibody (ACPA, Immunoglobulin binding protein (BiP

  3. False Position, Double False Position and Cramer's Rule

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    Boman, Eugene

    2009-01-01

    We state and prove the methods of False Position (Regula Falsa) and Double False Position (Regula Duorum Falsorum). The history of both is traced from ancient Egypt and China through the work of Fibonacci, ending with a connection between Double False Position and Cramer's Rule.

  4. Coinfection of hepatitis A virus genotype IA and IIIA complicated with autoimmune hemolytic anemia, prolonged cholestasis, and false-positive immunoglobulin M anti-hepatitis E virus: a case report.

    Science.gov (United States)

    Kim, Hee Sup; Jeong, Sook Hyang; Jang, Je Hyuck; Myung, Hyung Joon; Kim, Jin Wook; Bang, Soo Mee; Song, Sang Hoon; Kim, Haeryoung; Yun, Hae Sun

    2011-12-01

    A 37-year-old male presented with fever and jaundice was diagnosed as hepatitis A complicated with progressive cholestasis and severe autoimmune hemolytic anemia. He was treated with high-dose prednisolone (1.5 mg/kg), and eventually recovered. His initial serum contained genotype IA hepatitis A virus (HAV), which was subsequently replaced by genotype IIIA HAV. Moreover, at the time of development of hemolytic anemia, he became positive for immunoglobulin M (IgM) anti-hepatitis E virus (HEV). We detected HAV antigens in the liver biopsy specimen, while we detected neither HEV antigen in the liver nor HEV RNA in his serum. This is the first report of hepatitis A coinfected with two different genotypes manifesting with autoimmune hemolytic anemia, prolonged cholestasis, and false-positive IgM anti-HEV.

  5. The false positive exercise test

    International Nuclear Information System (INIS)

    Moritani, Kohshiro; Matsuda, Yasuo; Ozaki, Masaharu; Ogawa, Hiroshi; Ichiyama, Masaji; Matsuda, Masako; Kusukawa, Reizo

    1986-01-01

    Exercise tests with sublingual nitroglycerin were performed on 7 patients with true positive and 8 patients with false positive exercise test results. Four of 7 patients with true positive changes and 8 patients with false positive changes underwent exercise cardiac scintigraphy. Scintigrams showed perfusion defects in 4 patients with true positive outcomes, and no perfusion defect in 8 patients with false positive outcomes. Exercise tests with sublingual nitroglycerin were performed with the same load as that without nitroglycerin. In all 7 patients with true positive exercise test results, ST segment depression observed in the control exercise test was not observed in the nitroglycerin exercise test. In the false positive patients, ST segment depression observed in the control exercise test remained unchanged in 7 of 8 patients receiving nitroglycerin. Exercise tests with sublingual nitroglycerin as well as exercise cardiac scintigraphy are valuable tods in differentiating false positive from true positive patients. Furthermore, these data suggest that ST segment depression in the false positive patients may not be related to myocardial ischemia. (author)

  6. Falsely Elevated Plasma Creatinine Due to an Immunoglobulin M Paraprotein.

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    McGill, Mitchell R; Vijayan, Anitha; Trulock, Elbert P; Witt, Chad A; Kohler, Giselle D; Scott, Mitchell G

    2016-11-01

    The most common method for measuring plasma creatinine is based on its reaction with picric acid. However, enzymatic methods are becoming more popular due to improved specificity. We present a case of falsely elevated plasma creatinine values obtained by an enzymatic method that turned out to be due to a monoclonal immunoglobulin M (IgM) paraprotein. A 63-year-old woman evaluated for lung transplantation had falsely increased plasma creatinine levels (1.54-1.71mg/dL; corresponding to estimated glomerular filtration rates of 32-36 mL/min/1.73m 2 ) as measured by the Roche Creatinine plus enzymatic assay when compared with the picric acid-based procedure and several other enzymatic methods, which gave plasma creatinine values of 0.7 to 0.8mg/dL. Serum protein electrophoresis revealed an IgM κ light chain paraprotein. Removal of high-molecular-weight (>30kDa) proteins by ultrafiltration reduced the patient's plasma creatinine level by the Roche enzymatic method to 0.7mg/dL. Addition of the patient's immunoglobulin fraction to plasma from other patients with normal plasma creatinine levels resulted in values that were increased by 0.58 to 0.62mg/dL. Furthermore, removal of non-IgM immunoglobulins with protein G-coupled beads did not eliminate the interference from the patient's plasma. Taken together, these studies demonstrate that falsely elevated plasma creatinine values by the Roche enzymatic method can be due to an IgM paraprotein. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  7. False Positives in Exoplanet Detection

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    Leuquire, Jacob; Kasper, David; Jang-Condell, Hannah; Kar, Aman; Sorber, Rebecca; Suhaimi, Afiq; KELT (Kilodegree Extremely Little Telescope)

    2018-06-01

    Our team at the University of Wyoming uses a 0.6 m telescope at RBO (Red Buttes Observatory) to help confirm results on potential exoplanet candidates from low resolution, wide field surveys shared by the KELT (Kilodegree Extremely Little Telescope) team. False positives are common in this work. We carry out transit photometry, and this method comes with special types of false positives. The most common false positive seen at the confirmation level is an EB (eclipsing binary). Low resolution images are great in detecting multiple sources for photometric dips in light curves, but they lack the precision to decipher single targets at an accurate level. For example, target star KC18C030621 needed RBO’s photometric precision to determine there was a nearby EB causing exoplanet type light curves. Identifying false positives with our telescope is important work because it helps eliminate the waste of time taken by more expensive telescopes trying to rule out negative candidate stars. It also furthers the identification of other types of photometric events, like eclipsing binaries, so they can be studied on their own.

  8. False Positive and False Negative Effects on Network Attacks

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    Shang, Yilun

    2018-01-01

    Robustness against attacks serves as evidence for complex network structures and failure mechanisms that lie behind them. Most often, due to detection capability limitation or good disguises, attacks on networks are subject to false positives and false negatives, meaning that functional nodes may be falsely regarded as compromised by the attacker and vice versa. In this work, we initiate a study of false positive/negative effects on network robustness against three fundamental types of attack strategies, namely, random attacks (RA), localized attacks (LA), and targeted attack (TA). By developing a general mathematical framework based upon the percolation model, we investigate analytically and by numerical simulations of attack robustness with false positive/negative rate (FPR/FNR) on three benchmark models including Erdős-Rényi (ER) networks, random regular (RR) networks, and scale-free (SF) networks. We show that ER networks are equivalently robust against RA and LA only when FPR equals zero or the initial network is intact. We find several interesting crossovers in RR and SF networks when FPR is taken into consideration. By defining the cost of attack, we observe diminishing marginal attack efficiency for RA, LA, and TA. Our finding highlights the potential risk of underestimating or ignoring FPR in understanding attack robustness. The results may provide insights into ways of enhancing robustness of network architecture and improve the level of protection of critical infrastructures.

  9. An investigation of false positive dosimetry results

    International Nuclear Information System (INIS)

    Lewandowski, M.A.; Davis, S.A.; Goff, T.E.; Wu, C.F.

    1996-01-01

    The Waste Isolation Pilot Plant (WIPP) is a facility designed for the demonstration of the safe disposal of transuranic waste. Currently, the radiation source term is confined to sealed calibration and check sources since WIPP has not received waste for disposal. For several years the WIPP Dosimetry Group has operated a Harshaw Model 8800C reader to analyze Harshaw 8801-7776 thermoluminescent cards (3 TLD-700 and 1 TLD-600) with 8805 holder. The frequency of false positive results for quarterly dosimeter exchanges is higher than desired by the Dosimetry Group management. Initial observations suggested that exposure to intense ambient sunlight may be responsible for the majority of the false positive readings for element 3. A study was designed to investigate the possibility of light leaking through the holder and inducing a signal in element 3. This paper discusses the methods and results obtained, with special emphasis placed on recommendations to reduce the frequency of light-induced false positive readings

  10. False positive acetaminophen concentrations in icteric serum

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    L. de Jong

    2016-04-01

    Full Text Available Introduction: Serum concentrations of acetaminophen are measured to predict the risk of hepatotoxicity in cases of acetaminophen overdose and to identify acetaminophen use in patients with acute liver injury without a known cause. The acetaminophen concentration determines if treatment with N-acetyl cysteine, the antidote for acetaminophen poisoning, is warranted. Description: A 49-year-old woman was admitted to our hospital with a hepatic encephalopathy and a total serum bilirubin concentration of 442 µmol/l. The acetaminophen concentration of 11.5 mg/l was measured with an enzymatic-colorimetric assay, thus treatment with N-acetyl cysteine was started. Interestingly, the acetaminophen concentration remained unchanged (11.5–12.3 mg/l during a period of 4 consecutive days. In contrast, the acetaminophen concentration measured by HPLC, a chromatographic technique, remained undetectable Discussion: In the presented case, elevated bilirubin was the most likely candidate to interfere with acetaminophen assay causing false positive results. Bilirubin has intense absorbance in the ultraviolet and visible regions of the electromagnetic spectrum and for that reason it causes interference in an enzymatic-colorimetric assay. Conclusion: False positive acetaminophen laboratory test results may be found in icteric serum, when enzymatic-colorimetric assays are used for determination of an acetaminophen concentration. Questionable acetaminophen results in icteric serum should be confirmed by a non-enzymatic method, by means of ultrafiltration of the serum, or by dilution studies. Keywords: Acetaminophen, Enzymatic-colorimetric assays, HPLC, Bilirubin, Interference, Paracetamol, Liver failure, Jaundice

  11. Analysis of false positive and false negative cytological diagnosis of breast lesions

    International Nuclear Information System (INIS)

    Jamal, Awtif A.; Mansoor, I.

    2001-01-01

    To study the reasons for interpretive errors in false negative and false positive diagnosis of breast carcinoma on fine needle aspiration cytology material. We reviewed only those cases in which cytohistological discrepancies were found, where the cytologic material was abnormal and to some extent misinterpreted or both. There was only one false negative case (false negative fraction 0.32%) proved histologically as ductal carcinoma and four false positive cases (false positive fraction 1.2%); 2 fibroadenoma; 1 fibrocystic disease; and 1 stromal fibrosis. Smears of the two false positive fibroadenoma cases showed very high cellularity, overcrowded clusters and frequent stripped nuclei. The fibrocystic case showed tight clusters of apocrine cells and sheets of loosely aggregated macrophages that were over interpreted. Smears of the false negative ductal carcinoma was hypocellular overall, and the cells showed minimal nuclear pleomorphism. Overcrowded clusters and hypercellular smears should be carefully assessed for uniformity of cells and detailed nuclear and cytomorphological features. If the full-blown malignant cytomorphological changes are not visible, a diagnosis of suspicious or inconclusive should be made and frozen section recommended before surgery. Hypocellularity and relatively nuclear monomorphism are the reasons for failure to diagnose malignant breast lesions. Careful attention should be paid to extreme nuclear monomorphism and absence of naked bipolar cells. A cytologically atypical or suspicious diagnosis together with positive radiological and clinical findings should suggest a diagnosis of malignancy. (author)

  12. Consequences of a false-positive mammography result

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    von Euler-Chelpin, My; Bæksted, Christina; Vejborg, Ilse

    2016-01-01

    group used anxiolytic and antidepressant drugs. There was no difference in use of beta blockers. Hormone therapy was used more frequently by the false-positive, 36.6% versus 28.7%. The proportion of women using anxiolytic and antidepressant drugs increased with 19% from the before to the after period...... in the false-positive group, and with 16% in the normal group, resulting in an RRR of 1.02 (95% CI 0.92-1.14). RRR was 1.03 for beta blockers, 0.97 for hormone therapy. Conclusion(s): Drugs used to mitigate mood disorders were used more frequently by women with false-positive than by women with normal......Background: Previous research showed women experiencing false-positive mammograms to have greater anxiety about breast cancer than women with normal mammograms. To elucidate psychological effects of false-positive mammograms, we studied impact on drug intake.  Methods: We calculated the ratio...

  13. The problem of false positives and false negatives in violent video game experiments.

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    Ferguson, Christopher J

    The problem of false positives and negatives has received considerable attention in behavioral research in recent years. The current paper uses video game violence research as an example of how such issues may develop in a field. Despite decades of research, evidence on whether violent video games (VVGs) contribute to aggression in players has remained mixed. Concerns have been raised in recent years that experiments regarding VVGs may suffer from both "false positives" and "false negatives." The current paper examines this issue in three sets of video game experiments, two sets of video game experiments on aggression and prosocial behaviors identified in meta-analysis, and a third group of recent null studies. Results indicated that studies of VVGs and aggression appear to be particularly prone to false positive results. Studies of VVGs and prosocial behavior, by contrast are heterogeneous and did not demonstrate any indication of false positive results. However, their heterogeneous nature made it difficult to base solid conclusions on them. By contrast, evidence for false negatives in null studies was limited, and little evidence emerged that null studies lacked power in comparison those highlighted in past meta-analyses as evidence for effects. These results are considered in light of issues related to false positives and negatives in behavioral science more broadly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Accounting for False Positive HIV Tests: Is Visceral Leishmaniasis Responsible?

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    Shanks, Leslie; Ritmeijer, Koert; Piriou, Erwan; Siddiqui, M Ruby; Kliescikova, Jarmila; Pearce, Neil; Ariti, Cono; Muluneh, Libsework; Masiga, Johnson; Abebe, Almaz

    2015-01-01

    Co-infection with HIV and visceral leishmaniasis is an important consideration in treatment of either disease in endemic areas. Diagnosis of HIV in resource-limited settings relies on rapid diagnostic tests used together in an algorithm. A limitation of the HIV diagnostic algorithm is that it is vulnerable to falsely positive reactions due to cross reactivity. It has been postulated that visceral leishmaniasis (VL) infection can increase this risk of false positive HIV results. This cross sectional study compared the risk of false positive HIV results in VL patients with non-VL individuals. Participants were recruited from 2 sites in Ethiopia. The Ethiopian algorithm of a tiebreaker using 3 rapid diagnostic tests (RDTs) was used to test for HIV. The gold standard test was the Western Blot, with indeterminate results resolved by PCR testing. Every RDT screen positive individual was included for testing with the gold standard along with 10% of all negatives. The final analysis included 89 VL and 405 non-VL patients. HIV prevalence was found to be 12.8% (47/ 367) in the VL group compared to 7.9% (200/2526) in the non-VL group. The RDT algorithm in the VL group yielded 47 positives, 4 false positives, and 38 negatives. The same algorithm for those without VL had 200 positives, 14 false positives, and 191 negatives. Specificity and positive predictive value for the group with VL was less than the non-VL group; however, the difference was not found to be significant (p = 0.52 and p = 0.76, respectively). The test algorithm yielded a high number of HIV false positive results. However, we were unable to demonstrate a significant difference between groups with and without VL disease. This suggests that the presence of endemic visceral leishmaniasis alone cannot account for the high number of false positive HIV results in our study.

  15. Accounting for False Positive HIV Tests: Is Visceral Leishmaniasis Responsible?

    Directory of Open Access Journals (Sweden)

    Leslie Shanks

    Full Text Available Co-infection with HIV and visceral leishmaniasis is an important consideration in treatment of either disease in endemic areas. Diagnosis of HIV in resource-limited settings relies on rapid diagnostic tests used together in an algorithm. A limitation of the HIV diagnostic algorithm is that it is vulnerable to falsely positive reactions due to cross reactivity. It has been postulated that visceral leishmaniasis (VL infection can increase this risk of false positive HIV results. This cross sectional study compared the risk of false positive HIV results in VL patients with non-VL individuals.Participants were recruited from 2 sites in Ethiopia. The Ethiopian algorithm of a tiebreaker using 3 rapid diagnostic tests (RDTs was used to test for HIV. The gold standard test was the Western Blot, with indeterminate results resolved by PCR testing. Every RDT screen positive individual was included for testing with the gold standard along with 10% of all negatives. The final analysis included 89 VL and 405 non-VL patients. HIV prevalence was found to be 12.8% (47/ 367 in the VL group compared to 7.9% (200/2526 in the non-VL group. The RDT algorithm in the VL group yielded 47 positives, 4 false positives, and 38 negatives. The same algorithm for those without VL had 200 positives, 14 false positives, and 191 negatives. Specificity and positive predictive value for the group with VL was less than the non-VL group; however, the difference was not found to be significant (p = 0.52 and p = 0.76, respectively.The test algorithm yielded a high number of HIV false positive results. However, we were unable to demonstrate a significant difference between groups with and without VL disease. This suggests that the presence of endemic visceral leishmaniasis alone cannot account for the high number of false positive HIV results in our study.

  16. Coincidence of scintigraphic false positive and false negative findings in parathyroid and thyroid adenomas (case report)

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    Mana, O.; Zatta, G.; Boccolari, S.; Barbesti, S.; Tarolo, G.L.

    1987-04-01

    The subtractive double tracer scintigraphy with /sup 201/Tl and /sup 99m/Tc is a useful technique in studying parathyroid nodules; nevertheless, this method can give misleading informations especially in presence of thyroid nodules with false positive and false negative findings. In this case report the technique was applied in studying a patient with three nodules (two thyroid adenomas and one parathyroid adenoma), where both scintigraphic and echographic methods provided misleading informations. The selective uptake of /sup 201/Tl in the upper region of the right thyroid lobe gave a false positive finding, while the increased uptake of /sup 99m/Tc in a hyperfunctioning thyroid adenoma of left lobe masked the parathyroid adenoma laying below, giving a false negative finding.

  17. Epidemiology, public health, and the rhetoric of false positives

    DEFF Research Database (Denmark)

    Blair, Aaron; Saracci, Rodolfo; Vineis, Paolo

    2009-01-01

    BACKGROUND: As an observational science, epidemiology is regarded by some researchers as inherently flawed and open to false results. In a recent paper, Boffetta et al. [Boffetta P, McLaughlin JK, LaVecchia C, Tarone RE, Lipworth L, Blot WJ. False-positive results in cancer epidemiology: a plea f...

  18. False-positive 111In-pentetreotide Uptake in Gastritis

    International Nuclear Information System (INIS)

    Usmani, Sharjeel; Alshammari, Alshaima

    2013-01-01

    111 In-pentetreotide [ 111 In-octreoscan] is the most widely used radiolabeled somatostatin analog for evaluating neuroendocrine tumor overexpression of somatostatin receptors. False-positives studies of somatostatin receptor scintigraphy have been reported and often the cause is unexplained but assumed to be due to high number of somatostatin receptors in other pathologies. Causes of false-positives include visualization of the gallbladder, nasal mucosa and pulmonary hilar areas in respiratory infections, thyroid abnormalities, accessory spleens, recent Cerebrovascular accidents (CVA's) and activity at the site of a recent surgical incision. In infection or inflammation the cause of false-positive uptake is probably the result of tracer binding by somatostatin receptors on the inflammatory leukocytes. In this case report, we report, a 44-year-old male patient with false-positive 111 In-pentetreotide uptake due to gastritis

  19. Characterisation of false-positive observations in botanical surveys

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    Quentin J. Groom

    2017-05-01

    Full Text Available Errors in botanical surveying are a common problem. The presence of a species is easily overlooked, leading to false-absences; while misidentifications and other mistakes lead to false-positive observations. While it is common knowledge that these errors occur, there are few data that can be used to quantify and describe these errors. Here we characterise false-positive errors for a controlled set of surveys conducted as part of a field identification test of botanical skill. Surveys were conducted at sites with a verified list of vascular plant species. The candidates were asked to list all the species they could identify in a defined botanically rich area. They were told beforehand that their final score would be the sum of the correct species they listed, but false-positive errors counted against their overall grade. The number of errors varied considerably between people, some people create a high proportion of false-positive errors, but these are scattered across all skill levels. Therefore, a person’s ability to correctly identify a large number of species is not a safeguard against the generation of false-positive errors. There was no phylogenetic pattern to falsely observed species; however, rare species are more likely to be false-positive as are species from species rich genera. Raising the threshold for the acceptance of an observation reduced false-positive observations dramatically, but at the expense of more false negative errors. False-positive errors are higher in field surveying of plants than many people may appreciate. Greater stringency is required before accepting species as present at a site, particularly for rare species. Combining multiple surveys resolves the problem, but requires a considerable increase in effort to achieve the same sensitivity as a single survey. Therefore, other methods should be used to raise the threshold for the acceptance of a species. For example, digital data input systems that can verify

  20. False positive and false negative FDG-PET scans in various thoracic diseases

    International Nuclear Information System (INIS)

    Chang, Jung Min; Lee, Hyun Ju; Goo, Jin Mo; Lee, Ho Young; Lee, Jong Jin; Chung, June Key; Im, Jung Gi

    2006-01-01

    Fluorodeoxygucose (FDG)-positron emission tomography (PET) is being used more and more to differentiate benign form malignant focal lesions and it has been shown to be more efficacious than conventional chest computed tomography (CT). However, FDG is not a cancer-specific agent, and false positive findings in benign diseases have been reported. Infectious diseases (mycobacterial, fungal, bacterial infection), sarcoidosis, radiation pneumonitis and post-operative surgical conditions have shown intense uptake on PET scan. On the other hand, tumors with low glycolytic activity such as adenomas, bronchioloalveolar carcinomas, carcinoid tumors, low grade lymphomas and small sized tumors have revealed false negative findings on PET scan, Furthermore, in diseases located near the physiologic uptake sites (heart, bladder, kidney, and liver), FDG-PET should be complemented with other imaging modalities to confirm results and to minimize false negative findings. Familiarity with these false positive and negative findings will help radiologists interpret PET scans more accurately and also will help to determine the significance of the findings. In this review, we illustrate false positive and negative findings of PET scan in a variety of diseases

  1. Female False Positive Exercise Stress ECG Testing - Fact Verses Fiction.

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    Fitzgerald, Benjamin T; Scalia, William M; Scalia, Gregory M

    2018-03-07

    Exercise stress testing is a well validated cardiovascular investigation. Accuracy for treadmill stress electrocardiograph (ECG) testing has been documented at 60%. False positive stress ECGs (exercise ECG changes with non-obstructive disease on anatomical testing) are common, especially in women, limiting the effectiveness of the test. This study investigates the incidence and predictors of false positive stress ECG findings, referenced against stress echocardiography (SE) as a standard. Stress echocardiography was performed using the Bruce treadmill protocol. False positive stress ECG tests were defined as greater than 1mm of ST depression on ECG during exertion, without pain, with a normal SE. Potential causes for false positive tests were recorded before the test. Three thousand consecutive negative stress echocardiograms (1036 females, 34.5%) were analysed (age 59+/-14 years. False positive (F+) stress ECGs were documented in 565/3000 tests (18.8%). F+ stress ECGs were equally prevalent in females (194/1036, 18.7%) and males (371/1964, 18.9%, p=0.85 for the difference). Potential causes (hypertension, left ventricular hypertrophy, known coronary disease, arrhythmia, diabetes mellitus, valvular heart disease) were recorded in 36/194 (18.6%) of the female F+ ECG tests and 249/371 (68.2%) of the male F+ ECG tests (preinforce the value of stress imaging, particularly in women. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.

  2. Implications of false-positive results for future cancer screenings.

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    Taksler, Glen B; Keating, Nancy L; Rothberg, Michael B

    2018-06-01

    False-positive cancer screening results may affect a patient's willingness to obtain future screening. The authors conducted logistic regression analysis of 450,484 person-years of electronic medical records (2006-2015) in 92,405 individuals aged 50 to 75 years. Exposures were false-positive breast, prostate, or colorectal cancer screening test results (repeat breast imaging or negative breast biopsy ≤3 months after screening mammography, repeat prostate-specific antigen [PSA] test ≤3 months after PSA test result ≥4.0 ng/mL or negative prostate biopsy ≤3 months after any PSA result, or negative colonoscopy [without biopsy/polypectomy] ≤6 months after a positive fecal occult blood test). Outcomes were up-to-date status with breast or colorectal cancer screening. Covariates included prior screening history, clinical information (eg, family history, obesity, and smoking status), comorbidity, and demographics. Women were more likely to be up to date with breast cancer screening if they previously had false-positive mammography findings (adjusted odds ratio [AOR], 1.43 [95% confidence interval, 1.34-1.51] without breast biopsy and AOR, 2.02 [95% confidence interval, 1.56-2.62] with breast biopsy; both Pfalse-positive PSA testing were more likely to be up to date with colorectal cancer screening (AOR, 1.22 [P = .039] without prostate imaging/biopsy and AOR, 1.60 [P = .028] with imaging/biopsy). Results were stronger for individuals with more false-positive results (all P≤.005). However, women with previous false-positive colorectal cancer fecal occult blood test screening results were found to be less likely to be up to date with breast cancer screening (AOR, 0.73; Pfalse-positive breast or prostate cancer screening test were more likely to engage in future screening. Cancer 2018;124:2390-8. © 2018 American Cancer Society. © 2018 American Cancer Society.

  3. 'False-positive' and 'false-negative' test results in clinical urine drug testing.

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    Reisfield, Gary M; Goldberger, Bruce A; Bertholf, Roger L

    2009-08-01

    The terms 'false-positive' and 'false-negative' are widely used in discussions of urine drug test (UDT) results. These terms are inadequate because they are used in different ways by physicians and laboratory professionals and they are too narrow to encompass the larger universe of potentially misleading, inappropriate and unexpected drug test results. This larger universe, while not solely comprised of technically 'true' or 'false' positive or negative test results, presents comparable interpretive challenges with corresponding clinical implications. In this review, we propose the terms 'potentially inappropriate' positive or negative test results in reference to UDT results that are ambiguous or unexpected and subject to misinterpretation. Causes of potentially inappropriate positive UDT results include in vivo metabolic conversions of a drug, exposure to nonillicit sources of a drug and laboratory error. Causes of potentially inappropriate negative UDT results include limited assay specificity, absence of drug in the urine, presence of drug in the urine, but below established assay cutoff, specimen manipulation and laboratory error. Clinical UDT interpretation is a complicated task requiring knowledge of recent prescription, over-the-counter and herbal drug administration, drug metabolism and analytical sensitivities and specificities.

  4. Diagnosing periprosthetic infection: false-positive intraoperative Gram stains.

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    Oethinger, Margret; Warner, Debra K; Schindler, Susan A; Kobayashi, Hideo; Bauer, Thomas W

    2011-04-01

    Intraoperative Gram stains have a reported low sensitivity but high specificity when used to help diagnose periprosthetic infections. In early 2008, we recognized an unexpectedly high frequency of apparent false-positive Gram stains from revision arthroplasties. The purpose of this report is to describe the cause of these false-positive test results. We calculated the sensitivity and specificity of all intraoperative Gram stains submitted from revision arthroplasty cases during a 3-month interval using microbiologic cultures of the same samples as the gold standard. Methods of specimen harvesting, handling, transport, distribution, specimen processing including tissue grinding/macerating, Gram staining, and interpretation were studied. After a test modification, results of specimens were prospectively collected for a second 3-month interval, and the sensitivity and specificity of intraoperative Gram stains were calculated. The retrospective review of 269 Gram stains submitted from revision arthroplasties indicated historic sensitivity and specificity values of 23% and 92%, respectively. Systematic analysis of all steps of the procedure identified Gram-stained but nonviable bacteria in commercial broth reagents used as diluents for maceration of periprosthetic membranes before Gram staining and culture. Polymerase chain reaction and sequencing showed mixed bacterial DNA. Evaluation of 390 specimens after initiating standardized Millipore filtering of diluent fluid revealed a reduced number of positive Gram stains, yielding 9% sensitivity and 99% specificity. Clusters of false-positive Gram stains have been reported in other clinical conditions. They are apparently rare related to diagnosing periprosthetic infections but have severe consequences if used to guide treatment. Even occasional false-positive Gram stains should prompt review of laboratory methods. Our observations implicate dead bacteria in microbiologic reagents as potential sources of false-positive Gram

  5. Diagnostic Invasiveness and Psychosocial Consequences of False-Positive Mammography

    DEFF Research Database (Denmark)

    Heleno, Bruno M.; Siersma, Volkert Dirk; Brodersen, John

    2015-01-01

    PURPOSE: We undertook a study to assess whether women with false-positivemammography have worse psychosocial consequences if managed with aworkup that involves a biopsy (invasive group) than if managed with only additional imaging (noninvasive group). METHODS: We performed subgroup analysis...... of a cohort study of 454 womenwith abnormal screening mammography and 908 matched control women withnormal results. Using a condition-specific questionnaire (Consequences of Screening in Breast Cancer), we assessed 12 psychosocial consequences at 5 time points (0, 1, 6, 18, and 36 months after final diagnosis......) and compared the 2 groups of women with false-positives (invasive and noninvasive management groups). RESULTS: Among the 252 women with false-positive mammography eligible forthis study, psychosocial consequences were similar for those managed invasivelyand those managed noninvasively during the 36 months...

  6. False-positive results in pharmacoepidemiology and pharmacovigilance.

    Science.gov (United States)

    Bezin, Julien; Bosco-Levy, Pauline; Pariente, Antoine

    2017-09-01

    False-positive constitute an important issue in scientific research. In the domain of drug evaluation, it affects all phases of drug development and assessment, from the very early preclinical studies to the late post-marketing evaluations. The core concern associated with this false-positive is the lack of replicability of the results. Aside from fraud or misconducts, false-positive is often envisioned from the statistical angle, which considers them as a price to pay for type I error in statistical testing, and its inflation in the context of multiple testing. If envisioning this problematic in the context of pharmacoepidemiology and pharmacovigilance however, that both evaluate drugs in an observational settings, information brought by statistical testing and the significance of such should only be considered as additional to the estimates provided and their confidence interval, in a context where differences have to be a clinically meaningful upon everything, and the results appear robust to the biases likely to have affected the studies. In the following article, we consequently illustrate these biases and their consequences in generating false-positive results, through studies and associations between drug use and health outcomes that have been widely disputed. Copyright © 2017 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.

  7. APHRODITE: an Anomaly-based Architecture for False Positive Reduction

    NARCIS (Netherlands)

    Bolzoni, D.; Etalle, Sandro

    We present APHRODITE, an architecture designed to reduce false positives in network intrusion detection systems. APHRODITE works by detecting anomalies in the output traffic, and by correlating them with the alerts raised by the NIDS working on the input traffic. Benchmarks show a substantial

  8. A Demonstration of Regression False Positive Selection in Data Mining

    Science.gov (United States)

    Pinder, Jonathan P.

    2014-01-01

    Business analytics courses, such as marketing research, data mining, forecasting, and advanced financial modeling, have substantial predictive modeling components. The predictive modeling in these courses requires students to estimate and test many linear regressions. As a result, false positive variable selection ("type I errors") is…

  9. False-positive Human Papillomavirus DNA tests in cervical screening

    DEFF Research Database (Denmark)

    Rebolj, Matejka; Pribac, Igor; Lynge, Elsebeth

    2011-01-01

    Based on data from randomised controlled trials (RCT) on primary cervical screening, it has been reported that the problem of more frequent false-positive tests in Human Papillomavirus (HPV) DNA screening compared to cytology could be overcome. However, these reports predominantly operated...

  10. Evaluation of false positivity and cross reactivity in the investigation ...

    African Journals Online (AJOL)

    This study evaluated the causes of false positive Human Immunodeficiency Virus test results (F+HIV), cross reactivity of HIV antibodies with other non HIV antibodies, and efficiency of the serial and parallel testing algorithms. 100 blood samples randomly collected from clients attending the Heart to Heart HIV counseling and ...

  11. Detecting false positive sequence homology: a machine learning approach.

    Science.gov (United States)

    Fujimoto, M Stanley; Suvorov, Anton; Jensen, Nicholas O; Clement, Mark J; Bybee, Seth M

    2016-02-24

    Accurate detection of homologous relationships of biological sequences (DNA or amino acid) amongst organisms is an important and often difficult task that is essential to various evolutionary studies, ranging from building phylogenies to predicting functional gene annotations. There are many existing heuristic tools, most commonly based on bidirectional BLAST searches that are used to identify homologous genes and combine them into two fundamentally distinct classes: orthologs and paralogs. Due to only using heuristic filtering based on significance score cutoffs and having no cluster post-processing tools available, these methods can often produce multiple clusters constituting unrelated (non-homologous) sequences. Therefore sequencing data extracted from incomplete genome/transcriptome assemblies originated from low coverage sequencing or produced by de novo processes without a reference genome are susceptible to high false positive rates of homology detection. In this paper we develop biologically informative features that can be extracted from multiple sequence alignments of putative homologous genes (orthologs and paralogs) and further utilized in context of guided experimentation to verify false positive outcomes. We demonstrate that our machine learning method trained on both known homology clusters obtained from OrthoDB and randomly generated sequence alignments (non-homologs), successfully determines apparent false positives inferred by heuristic algorithms especially among proteomes recovered from low-coverage RNA-seq data. Almost ~42 % and ~25 % of predicted putative homologies by InParanoid and HaMStR respectively were classified as false positives on experimental data set. Our process increases the quality of output from other clustering algorithms by providing a novel post-processing method that is both fast and efficient at removing low quality clusters of putative homologous genes recovered by heuristic-based approaches.

  12. Risk factors for false positive and for false negative test results in screening with fecal occult blood testing

    NARCIS (Netherlands)

    Stegeman, Inge; de Wijkerslooth, Thomas R.; Stoop, Esther M.; van Leerdam, Monique; van Ballegooijen, M.; Kraaijenhagen, Roderik A.; Fockens, Paul; Kuipers, Ernst J.; Dekker, Evelien; Bossuyt, Patrick M.

    2013-01-01

    Differences in the risk of a false negative or a false positive fecal immunochemical test (FIT) across subgroups may affect optimal screening strategies. We evaluate whether subgroups are at increased risk of a false positive or a false negative FIT result, whether such variability in risk is

  13. Accurate decisions in an uncertain world: collective cognition increases true positives while decreasing false positives

    NARCIS (Netherlands)

    Wolf, M.; Kurvers, R.H.J.M.; Ward, A.J.W.; Krause, S.; Krause, J.

    2013-01-01

    In a wide range of contexts, including predator avoidance, medical decision-making and security screening, decision accuracy is fundamentally constrained by the trade-off between true and false positives. Increased true positives are possible only at the cost of increased false positives;

  14. When are false-positive and false-negative 18F'FDG PET scans really false?

    International Nuclear Information System (INIS)

    Binns, D.S.; Hicks, R.J.; Fawcett, M.E.

    1999-01-01

    Full text: A 61-year-old male presented with locally advanced squamous cell carcinoma of the base of tongue. In the absence of wider metastatic disease on conventional staging, he was enrolled in a phase I, dose escalation chemoradiotherapy trial. In this study, therapeutic response to radiotherapy combined with cisplatin and a chemotherapeutic agent which specifically targets hypoxic cells (tirapazamine) was evaluated with serial 18 F-FDG PET scans. Baseline 18 F-FDG PET confirmed locally advanced disease, although a previously undetected lower cervical lymph node was identified and included in the radiotherapy portal. Whole-body PET revealed a small metabolically active area adjacent to the right hemidiaphragm. Respiratory gated, high-resolution helical CT failed to find structural evidence of disease and, as a result, the patient was enrolled in the 7 week therapy regime on the assumption that the PET finding was a false-positive result. Repeat 18 F-FDG PET scans at the middle, end and 12 weeks post-treatment showed excellent therapeutic response in the head and neck which was discordant with clinical and CT findings, and resolution of the metabolically active chest lesion. Despite the negative PET scan, persistent clinical and CT evidence of a residual tumour mass suggested a false-negative result and resulted in a neck lymph node dissection. This showed no evidence of malignant cells. Five months following treatment, the patient presented with pleural effusion at the base on the right lung. Subsequent CT scanning showed a small pleural lesion at the site of initial 18 F-FDG uptake. Biopsy confirmed metastatic disease. The apparent transient resolution of 18 F-FDG uptake in the pleural lesion with treatment presumably reflected a combination of reduced metabolic activity and size due to the partial, but not complete, cytotoxic effects of cisplatin. In conclusion, this case emphasizes the importance of pathological review and clinical follow-up in reconciling

  15. Falsely low immunoglobulin (Ig)G4 in routine analysis: how not to miss IgG4 disease.

    Science.gov (United States)

    Egner, W; Swallow, K; Lock, R J; Patel, D

    2016-10-01

    Immunoglobulin (Ig)G4 disease can have apparently 'normal' levels of IgG4 due to antigen excess conditions. IgG4 measurement therefore appears falsely low. UK National External Quality Assurance Scheme (UK NEQAS) data and other reports have suggested that this problem occurred despite pre-existing antigen excess detection steps. To determine the clinical relevance of the problem, we examined the prevalence and characteristics of prozoning in our laboratory and patient cohorts. We establish that the prevalence of raised IgG4 in routine IgG4 analysis is low (IgG4 samples in our patients. This may explain the previous reports of low sensitivity of raised IgG4 for IgG4RD, and predictive values should be re-evaluated in this disease using modified prozone-resistant protocols. All laboratories providing IgG4 measurements should verify that their assays are fit for the clinical quality requirement of detection raised IgG4 levels and must verify the upper limit of their reference ranges and freedom from prozoning. © 2016 British Society for Immunology.

  16. Adrenocortical Carcinoma: False Positive in an I-123 Metaiodobenzylguanidine Scan

    Energy Technology Data Exchange (ETDEWEB)

    Rey, Cristina Rodriguez; Candil, Aida Ortega; Galvan, Eliseo Vano; Martin, Maria Nieves Cabrera; Delgado, Jose Luis Carreras [Clinico San Carlos Hospital, Madrid (Spain)

    2016-06-15

    A 55-year-old man with a personal his history of left pheochromocytoma 2 years previously presented with an abdominal ultrasound showed a large left upper quadrant solid mass (calipers), with heterogeneous echogenicity and central cystic degeneration areas or necrosis. F-18 Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT was performed as ACC was suspected. ACC is an uncommon malignant neoplasm of unknown cause; however, smoking and oral contraceptives may be risk factors. Patients usually present with advanced-stage disease and have poor prognosis, with a 2-year recurrence rate that ranges form 73 to 86 %. An MIBG scan was performed after injection of 185 MBq of I-123 MIBG intravenously. Single photon emission tomography (SPECT)/CT scan showed abnormal isotope accumulation in the tumor region. The patient underwent total resection of the tumor. The histology was of ACC, with areas of necrosis and cystic areas, so the result of the MIBG scan was a false positive. Authors divided false-positive MIBG studies into three categories. The first category is neuroendocrine lesions other than pheochromocytomas (tumors of the APUD series). the second category consists in adrenal lesions other than pheochromocytomas (adenomas, ACC) the reasons for this abnormal uptake are unclear. The third category consists of tracer uptake adjacent to the adrenal due to abnormalities in the route of excretion.

  17. THE XO PLANETARY SURVEY PROJECT: ASTROPHYSICAL FALSE POSITIVES

    International Nuclear Information System (INIS)

    Poleski, Radosaw; McCullough, Peter R.; Valenti, Jeff A.; Burke, Christopher J.; Machalek, Pavel; Janes, Kenneth

    2010-01-01

    Searches for planetary transits find many astrophysical false positives as a by-product. There are four main types analyzed in the literature: a grazing-incidence eclipsing binary (EB) star, an EB star with a small radius companion star, a blend of one or more stars with an unrelated EB star, and a physical triple star system. We present a list of 69 astrophysical false positives that had been identified as candidates of transiting planets of the on-going XO survey. This list may be useful in order to avoid redundant observation and characterization of these particular candidates that have been independently identified by other wide-field searches for transiting planets. The list may be useful for those modeling the yield of the XO survey and surveys similar to it. Subsequent observations of some of the listed stars may improve mass-radius relations, especially for low-mass stars. From the candidates exhibiting eclipses, we report three new spectroscopic double-line binaries and give mass function estimations for 15 single-line spectroscopic binaries.

  18. False positive paediatric labelled white blood cell study

    International Nuclear Information System (INIS)

    Beveridge, N.; Bennett, E.; Thomas, P.

    2002-01-01

    Full text: An eight-month-old female presented for a technetium labelled white blood cell study (LWBC) to exclude an intra-abdominal abscess. Born premature, the child had surgery to repair a perforated bowel and had repeated presentations with diarrhoea, fevers, a tender right upper quadrant and a raised leucocyte count. Multiple imaging modalities failed to demonstrate recurrent bowel perforation, ischaemia or an intra-abdominal mass. A LWBC study was performed with whole body imaging at 1 and 5 hours post re-injection of the radiolabelled blood. No abnormal uptake was visualised in the abdomen but abnormal white cell accumulation was noted in the right hind foot and the length of the right lower leg. This activity appeared to lie along the course of the right tibia. Plain X-ray demonstrated no evidence of tibial osteomyelitis. Concern that the LWBC may be falsely negative in a patient on antibiotics, a gallium scan was immediately performed to re-examine the abdomen. The whole body gallium images demonstrated normal physiological uptake in the abdomen and no evidence of infection in the right leg. The patient had no clinical features to support right leg pathology. The abnormal LWBC localisation in the right lower leg/foot was therefore falsely positive. The most likely explanation is increased activation of the autologous LWBC by 'rough' handling during difficult venesection and re-injection through small veins and needles/cannulas. The slow flow through the veins draining the foot injection site would contribute to margination in these vessel walls. This is a potential cause for false positive LWBC studies- with significant implications for patient care. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  19. Protein complex prediction via dense subgraphs and false positive analysis.

    Directory of Open Access Journals (Sweden)

    Cecilia Hernandez

    Full Text Available Many proteins work together with others in groups called complexes in order to achieve a specific function. Discovering protein complexes is important for understanding biological processes and predict protein functions in living organisms. Large-scale and throughput techniques have made possible to compile protein-protein interaction networks (PPI networks, which have been used in several computational approaches for detecting protein complexes. Those predictions might guide future biologic experimental research. Some approaches are topology-based, where highly connected proteins are predicted to be complexes; some propose different clustering algorithms using partitioning, overlaps among clusters for networks modeled with unweighted or weighted graphs; and others use density of clusters and information based on protein functionality. However, some schemes still require much processing time or the quality of their results can be improved. Furthermore, most of the results obtained with computational tools are not accompanied by an analysis of false positives. We propose an effective and efficient mining algorithm for discovering highly connected subgraphs, which is our base for defining protein complexes. Our representation is based on transforming the PPI network into a directed acyclic graph that reduces the number of represented edges and the search space for discovering subgraphs. Our approach considers weighted and unweighted PPI networks. We compare our best alternative using PPI networks from Saccharomyces cerevisiae (yeast and Homo sapiens (human with state-of-the-art approaches in terms of clustering, biological metrics and execution times, as well as three gold standards for yeast and two for human. Furthermore, we analyze false positive predicted complexes searching the PDBe (Protein Data Bank in Europe database in order to identify matching protein complexes that have been purified and structurally characterized. Our analysis shows

  20. Accurate decisions in an uncertain world: collective cognition increases true positives while decreasing false positives.

    Science.gov (United States)

    Wolf, Max; Kurvers, Ralf H J M; Ward, Ashley J W; Krause, Stefan; Krause, Jens

    2013-04-07

    In a wide range of contexts, including predator avoidance, medical decision-making and security screening, decision accuracy is fundamentally constrained by the trade-off between true and false positives. Increased true positives are possible only at the cost of increased false positives; conversely, decreased false positives are associated with decreased true positives. We use an integrated theoretical and experimental approach to show that a group of decision-makers can overcome this basic limitation. Using a mathematical model, we show that a simple quorum decision rule enables individuals in groups to simultaneously increase true positives and decrease false positives. The results from a predator-detection experiment that we performed with humans are in line with these predictions: (i) after observing the choices of the other group members, individuals both increase true positives and decrease false positives, (ii) this effect gets stronger as group size increases, (iii) individuals use a quorum threshold set between the average true- and false-positive rates of the other group members, and (iv) individuals adjust their quorum adaptively to the performance of the group. Our results have broad implications for our understanding of the ecology and evolution of group-living animals and lend themselves for applications in the human domain such as the design of improved screening methods in medical, forensic, security and business applications.

  1. The OGCleaner: filtering false-positive homology clusters.

    Science.gov (United States)

    Fujimoto, M Stanley; Suvorov, Anton; Jensen, Nicholas O; Clement, Mark J; Snell, Quinn; Bybee, Seth M

    2017-01-01

    Detecting homologous sequences in organisms is an essential step in protein structure and function prediction, gene annotation and phylogenetic tree construction. Heuristic methods are often employed for quality control of putative homology clusters. These heuristics, however, usually only apply to pairwise sequence comparison and do not examine clusters as a whole. We present the Orthology Group Cleaner (the OGCleaner), a tool designed for filtering putative orthology groups as homology or non-homology clusters by considering all sequences in a cluster. The OGCleaner relies on high-quality orthologous groups identified in OrthoDB to train machine learning algorithms that are able to distinguish between true-positive and false-positive homology groups. This package aims to improve the quality of phylogenetic tree construction especially in instances of lower-quality transcriptome assemblies. https://github.com/byucsl/ogcleaner CONTACT: sfujimoto@gmail.comSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Reduction of lymph tissue false positives in pulmonary embolism detection

    Science.gov (United States)

    Ghanem, Bernard; Liang, Jianming; Bi, Jinbo; Salganicoff, Marcos; Krishnan, Arun

    2008-03-01

    Pulmonary embolism (PE) is a serious medical condition, characterized by the partial/complete blockage of an artery within the lungs. We have previously developed a fast yet effective approach for computer aided detection of PE in computed topographic pulmonary angiography (CTPA),1 which is capable of detecting both acute and chronic PEs, achieving a benchmark performance of 78% sensitivity at 4 false positives (FPs) per volume. By reviewing the FPs generated by this system, we found the most dominant type of FP, roughly one third of all FPs, to be lymph/connective tissue. In this paper, we propose a novel approach that specifically aims at reducing this FP type. Our idea is to explicitly exploit the anatomical context configuration of PE and lymph tissue in the lungs: a lymph FP connects to the airway and is located outside the artery, while a true PE should not connect to the airway and must be inside the artery. To realize this idea, given a detected candidate (i.e. a cluster of suspicious voxels), we compute a set of contextual features, including its distance to the airway based on local distance transform and its relative position to the artery based on fast tensor voting and Hessian "vesselness" scores. Our tests on unseen cases show that these features can reduce the lymph FPs by 59%, while improving the overall sensitivity by 3.4%.

  3. False-positive head-impulse test in cerebellar ataxia

    Directory of Open Access Journals (Sweden)

    Olympia eKremmyda

    2012-11-01

    Full Text Available Abstract:The objective of this study was to compare the findings of the bedside head impulse test (HIT, passive head rotation gain, and caloric irrigation in patients with cerebellar ataxia (CA. In 16 patients with CA and bilaterally pathological bedside HIT, VOR gains were measured during HIT and passive head rotation by scleral search coil technique. Eight of the patients had pathologically reduced caloric responsiveness, while the other eight had normal caloric responses. Those with normal calorics showed a slightly reduced HIT gain (mean±SD: 0.73±0.15. In those with pathological calorics, gains 80ms and 100 ms after the HIT as well as the passive rotation VOR gains were significantly lower. The corrective saccade after head turn occurred earlier in patients with pathological calorics (111±62 ms after onset of the HIT than in those with normal calorics. (191±17 ms, p=0.0064 We indentified two groups of patients with CA: those with an isolated moderate HIT deficit only, probably due to floccular dysfunction, and those with combined HIT, passive rotation and caloric deficit, probably due to a peripheral vestibular deficit. From a clinical point of view, these results show that the bedside HIT alone can be false positive for establishing a diagnosis of a bilateral peripheral vestibular deficit in patients with CA.

  4. Easy fix for clinical laboratories for the false-positive defect with the Abbott AxSym total beta-hCG test.

    Science.gov (United States)

    Cole, Laurence A; Khanlian, Sarah A

    2004-05-01

    False-positive hCG results can lead to erroneous diagnoses and needless chemotherapy and surgery. In the last 2 years, eight publications described cases involving false-positive hCG tests; all eight involved the AxSym test. We investigated the source of this abundance of cases and a simple fix that may be used by clinical laboratories. False-positive hCG was primarily identified by absence of hCG in urine and varying or negative hCG results in alternative tests. Seventeen false-positive serum samples in the AxSym test were evaluated undiluted and at twofold dilution with diluent containing excess goat serum or immunoglobulin. We identified 58 patients with false-positive hCG, 47 of 58 due to the Abbott AxSym total hCGbeta test (81%). Sixteen of 17 of these "false-positive" results (mean 100 mIU/ml) became undetectable when tested again after twofold dilution. A simple twofold dilution with this diluent containing excess goat serum or immunoglobulin completely protected 16 of 17 samples from patients having false-positive results. It is recommended that laboratories using this test use twofold dilution as a minimum to prevent false-positive results.

  5. A case of coombs-positive severe late anemia without hyperbilirubinemia, refractory to blood transfusion, improved with immunoglobulin

    Directory of Open Access Journals (Sweden)

    Supriya Kushwah

    2017-01-01

    Full Text Available Rhesus hemolytic disease of newborn is a well-known disease with early and late complications mainly manifesting as severe hyperbilirubinemia requiring prompt treatment such as exchange transfusion and immunoglobulins. We report a case of Coombs-positive severe late anemia without hyperbilirubinemia which presented with features such as sepsis and failure to gain weight. Baby was refractory to blood transfusion initially, but later on successfully improved with immunoglobulins.

  6. Risk of breast cancer after false-positive test results in screening mammography

    DEFF Research Database (Denmark)

    von Euler-Chelpin, My Catarina; Risør, Louise Madeleine; Thorsted, Brian Larsen

    2012-01-01

    Screening for disease in healthy people inevitably leads to some false-positive tests in disease-free individuals. Normally, women with false-positive screening tests for breast cancer are referred back to routine screening. However, the long-term outcome for women with false-positive tests...

  7. Memory for media: investigation of false memories for negatively and positively charged public events.

    Science.gov (United States)

    Porter, Stephen; Taylor, Kristian; Ten Brinke, Leanne

    2008-01-01

    Despite a large body of false memory research, little has addressed the potential influence of an event's emotional content on susceptibility to false recollections. The Paradoxical Negative Emotion (PNE) hypothesis predicts that negative emotion generally facilitates memory but also heightens susceptibility to false memories. Participants were asked whether they could recall 20 "widely publicised" public events (half fictitious) ranging in emotional valence, with or without visual cues. Participants recalled a greater number of true negative events (M=3.31/5) than true positive (M=2.61/5) events. Nearly everyone (95%) came to recall at least one false event (M=2.15 false events recalled). Further, more than twice as many participants recalled any false negative (90%) compared to false positive (41.7%) events. Negative events, in general, were associated with more detailed memories and false negative event memories were more detailed than false positive event memories. Higher dissociation scores were associated with false recollections of negative events, specifically.

  8. Monoclonal antibodies to snakehead, Channa striata immunoglobulins: detection and quantification of immunoglobulin-positive cells in blood and lymphoid organs.

    Science.gov (United States)

    Sood, Neeraj; Chaudhary, Dharmendra K; Rathore, Gaurav; Singh, Akhilesh; Lakra, W S

    2011-02-01

    Snakehead Channa striata is an important freshwater food fish in many Southeast Asian countries. Three monoclonal antibodies (C9, C10 and D10) were developed against purified serum immunoglobulins of Channa striata (Cs-Ig) and characterized. C9 and D10 MAbs were specific to heavy chain, while C10 MAb detected only unreduced Cs-Ig in western blotting. In competitive ELISA, C9 and C10 MAbs were specific to C. striata Ig and showed no cross reactivity with serum Ig of other fish species i.e. Channa punctatus, Channa marulius, Clarias batrachus and Labeo rohita. D10 MAb showed reactivity to serum Ig of C. striata and C. marulius. In FACS analysis of gated lymphocytes, the percentage of Ig+ cells detected by C9 MAb was 18.2%, 27.7% and 10.3% in blood, spleen and kidney, respectively (n=3, body weight 500-600 g). However, only a few cells (0.5%) were found to be Ig+ in thymus (n=5). C9 MAb was also successfully employed to demonstrate Ig+ cells in blood smears and formalin fixed sections of spleen and kidney. These findings suggest that the spleen plays an important role in humoral immunity as compared to head kidney. Further, these MAbs can be useful immunological tool in monitoring health status of cultured C. striata. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Look Again: An Investigation of False Positive Detections in Combat Models

    National Research Council Canada - National Science Library

    Wainwright, Ryan K

    2008-01-01

    .... Existing combat models tend to overlook or downplay false positive detections. Signal Detection Theory provides the framework for analysis of an observer's hits, misses, correct rejections, and false alarms...

  10. Participation behaviour following a false positive test in the Copenhagen mammography screening programme

    DEFF Research Database (Denmark)

    Andersen, Sune Bangsbøll; Vejborg, Ilse; von Euler-Chelpin, My

    2008-01-01

    women experiencing a negative screening test, regardless of whether the false positive statement was given following assessment or following surgery. The benign to malignant biopsy ratio, comparing the type B false positives to the true positives, was by the fifth round well below the desirable level...

  11. The risk factor of false-negative and false-positive for T-SPOT.TB in active tuberculosis.

    Science.gov (United States)

    Di, Li; Li, Yan

    2018-02-01

    T-SPOT.TB is a promising diagnosis tool to identify both pulmonary tuberculosis and extrapulmonary tuberculosis, as well as latent tuberculosis; however, the factors that affect the results of T-SPOT.TB remains unclear. In this study, we aim to figure out the risk factor of T-SPOT.TB for active TB. A total of 349 patients were recruited between January 1st, 2016 and January 22st, 2017 at Renmin Hospital of Wuhan University, including 98 subjects with TB and 251 subjects with non-TB disease, and received T-SPOT.TB (Oxford Immunotec Ltd). Statistics were analyzed by SPSS 19.0 using logistic regression. The overall specificity and sensitivity of the T-SPOT.TB was 92.83% (233/251; 95%CI 0.8872-0.9557) and 83.67% (82/98; 95%CI 0.7454-0.9010), respectively. Patients with tuberculous meningitis were more likely to have false-negative results (OR 17.4, 95%CI 3.068-98.671; P.05). Tuberculous meningitis was a risk factor of false-negative for T-SPOT.TB, while cured TB was a risk factor of false-positive. © 2017 Wiley Periodicals, Inc.

  12. Nuclear positioning rather than contraction controls ordered rearrangements of immunoglobulin loci.

    Science.gov (United States)

    Rother, Magdalena B; Palstra, Robert-Jan; Jhunjhunwala, Suchit; van Kester, Kevin A M; van IJcken, Wilfred F J; Hendriks, Rudi W; van Dongen, Jacques J M; Murre, Cornelis; van Zelm, Menno C

    2016-01-08

    Progenitor-B cells recombine their immunoglobulin (Ig) loci to create unique antigen receptors. Despite a common recombination machinery, the Ig heavy and Ig light chain loci rearrange in a stepwise manner. We studied pre-pro-B cells and Rag(-/-) progenitor-B cells to determine whether Ig locus contraction or nuclear positioning is decisive for stepwise rearrangements. We found that both Ig loci were contracted in pro-B and pre-B cells. Igh relocated from the nuclear lamina to central domains only at the pro-B cell stage, whereas, Igκ remained sequestered at the lamina, and only at the pre-B cell stage located to central nuclear domains. Finally, in vitro induced re-positioning of Ig alleles away from the nuclear periphery increased germline transcription of Ig loci in pre-pro-B cells. Thus, Ig locus contraction juxtaposes genomically distant elements to mediate efficient recombination, however, sequential positioning of Ig loci away from the nuclear periphery determines stage-specific accessibility of Ig loci. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. Generating false negatives and false positives for As and Mo concentrations in groundwater due to well installation.

    Science.gov (United States)

    Wallis, Ilka; Pichler, Thomas

    2018-08-01

    Groundwater monitoring relies on the acquisition of 'representative' groundwater samples, which should reflect the ambient water quality at a given location. However, drilling of a monitoring well for sample acquisition has the potential to perturb groundwater conditions to a point that may prove to be detrimental to the monitoring objective. Following installation of 20 monitoring wells in close geographic proximity in central Florida, opposing concentration trends for As and Mo were observed. In the first year after well installation As and Mo concentrations increased in some wells by a factor of 2, while in others As and Mo concentrations decreased by a factor of up to 100. Given this relatively short period of time, a natural change in groundwater composition of such magnitude is not expected, leaving well installation itself as the likely cause for the observed concentration changes. Hence, initial concentrations were identified as 'false negatives' if concentrations increased with time or as 'false positives' if concentrations decreased. False negatives were observed if concentrations were already high, i.e., the As or Mo were present at the time of drilling. False positives were observed if concentrations were relatively lower, i.e., As or Mo were present at low concentrations of approximately 1 to 2μg/L before drilling, but then released from the aquifer matrix as a result of drilling. Generally, As and Mo were present in the aquifer matrix in either pyrite or organic matter, both of which are susceptible to dissolution if redox conditions change due to the addition of oxygen. Thus, introduction of an oxidant into an anoxic aquifer through use of an oxygen saturated drilling fluid served as the conceptual model for the trends where concentrations decreased with time. Mixing between drilling fluid and groundwater (i.e., dilution) was used as the conceptual model for scenarios where increasing trends were observed. Conceptual models were successfully tested

  14. Addressing False Positives in Early Reading Assessment Using Intervention Response Data

    Science.gov (United States)

    McAlenney, Athena Lentini; Coyne, Michael D.

    2015-01-01

    The current study examined a solution to high false positive reading risk classification rates in early kindergarten by investigating a method of identifying students with possible false positive risk classifications and returning them to general classroom instruction. Researchers assessed kindergarten students (N = 105) identified as at risk who…

  15. False-positive results in mammographic screening for breast cancer in Europe

    DEFF Research Database (Denmark)

    Hofvind, Solveig; Ponti, Antonio; Patnick, Julietta

    2012-01-01

    To estimate the cumulative risk of a false-positive screening result in European mammographic screening programmes, and examine the rates and procedures of further assessment.......To estimate the cumulative risk of a false-positive screening result in European mammographic screening programmes, and examine the rates and procedures of further assessment....

  16. Risk of breast cancer after false-positive results in mammographic screening

    DEFF Research Database (Denmark)

    Roman, Marta; Castells, Xavier; Hofvind, Solveig

    2016-01-01

    risk (RR) of screen-detected cancer for women with false-positive versus negative results. We analyzed information from 1,935,093 women 50–69 years who underwent 6,094,515 screening exams. During an average 5.8 years of follow-up, 230,609 (11.9%) women received a false-positive result and 27,849 (1......Women with false-positive results are commonly referred back to routine screening. Questions remain regarding their long-term outcome of breast cancer. We assessed the risk of screen-detected breast cancer in women with false-positive results. We conducted a joint analysis using individual level.......4%) were diagnosed with screen-detected cancer. The adjusted RR of screen-detected cancer after a false-positive result was 2.01 (95% CI: 1.93–2.09). Women who tested false-positive at first screen had a RR of 1.86 (95% CI: 1.77–1.96), whereas those who tested false-positive at third screening had a RR...

  17. Increased risk of breast cancer in women with false-positive test

    DEFF Research Database (Denmark)

    von Euler-Chelpin, My; Kuchiki, Megumi; Vejborg, Ilse

    2014-01-01

    of misclassification, i.e. women who were actually false-negatives instead of false-positives. METHOD: We used data from the Copenhagen Mammography Screening Programme, Denmark. The study population was the 295 women, out of 4743 recalled women from a total of 58,003 participants, with a false-positive test during...... the women with misclassified tests had been excluded, there was an excess risk of breast cancer of 27% (RR=1.27, 95% confidence interval (CI), 1.11-1.46) among the women with a false-positive test compared to women with only negative tests. Women with a false-positive test determined at assessment had...... an excess risk of 27%, while false-positives determined at surgery had an excess risk of 30%. CONCLUSIONS: The results indicate that the increased risk is not explained only by misclassification. The excess risk remains for false-positives determined at assessment as well as at surgery, which favours some...

  18. Reducing false-positive incidental findings with ensemble genotyping and logistic regression based variant filtering methods.

    Science.gov (United States)

    Hwang, Kyu-Baek; Lee, In-Hee; Park, Jin-Ho; Hambuch, Tina; Choe, Yongjoon; Kim, MinHyeok; Lee, Kyungjoon; Song, Taemin; Neu, Matthew B; Gupta, Neha; Kohane, Isaac S; Green, Robert C; Kong, Sek Won

    2014-08-01

    As whole genome sequencing (WGS) uncovers variants associated with rare and common diseases, an immediate challenge is to minimize false-positive findings due to sequencing and variant calling errors. False positives can be reduced by combining results from orthogonal sequencing methods, but costly. Here, we present variant filtering approaches using logistic regression (LR) and ensemble genotyping to minimize false positives without sacrificing sensitivity. We evaluated the methods using paired WGS datasets of an extended family prepared using two sequencing platforms and a validated set of variants in NA12878. Using LR or ensemble genotyping based filtering, false-negative rates were significantly reduced by 1.1- to 17.8-fold at the same levels of false discovery rates (5.4% for heterozygous and 4.5% for homozygous single nucleotide variants (SNVs); 30.0% for heterozygous and 18.7% for homozygous insertions; 25.2% for heterozygous and 16.6% for homozygous deletions) compared to the filtering based on genotype quality scores. Moreover, ensemble genotyping excluded > 98% (105,080 of 107,167) of false positives while retaining > 95% (897 of 937) of true positives in de novo mutation (DNM) discovery in NA12878, and performed better than a consensus method using two sequencing platforms. Our proposed methods were effective in prioritizing phenotype-associated variants, and an ensemble genotyping would be essential to minimize false-positive DNM candidates. © 2014 WILEY PERIODICALS, INC.

  19. False-positive radioactive iodine uptake mimicking miliary lung metastases in a patient affected by papillary thyroid cancer and IgA deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Demidowich, Andrew Paul; Reynolds, James C. [National Institutes of Health, Bethesda (United States); Kundu, Amartya [Dept. of MedicineUniversity of Massachusetts Medical School, Worcester (United States); Celi, Francesco S. [Div. of Endocrinology and MetabolismVirginia Commonwealth UniversityRichmond (United States)

    2016-09-15

    A 42-year-old female with immunoglobulin A deficiency and recurrent sinopulmonary infections underwent thyroidectomy for papillary thyroid cancer (PTC). Follow-up {sup 123}I scintigraphy demonstrated diffuse pulmonary uptake, suggesting metastatic disease. However, subsequent pathologic, biochemical and radiographic testing proved that she was in fact disease free, and the initial {sup 123}I pulmonary uptake was identified as a false positive. Inflammatory conditions may rarely cause iodine uptake in non-thyroidal tissues due to local retention, organification, and/or immunologic utilization. To avoid exposing patients to unnecessary treatments, it is critical for clinicians to recognize that comorbid pulmonary conditions may mimic metastatic PTC on radioiodine scintigraphy.

  20. Public health consequences of a false-positive laboratory test result for Brucella--Florida, Georgia, and Michigan, 2005.

    Science.gov (United States)

    2008-06-06

    Human brucellosis, a nationally notifiable disease, is uncommon in the United States. Most human cases have occurred in returned travelers or immigrants from regions where brucellosis is endemic, or were acquired domestically from eating illegally imported, unpasteurized fresh cheeses. In January 2005, a woman aged 35 years who lived in Nassau County, Florida, received a diagnosis of brucellosis, based on results of a Brucella immunoglobulin M (IgM) enzyme immunoassay (EIA) performed in a commercial laboratory using analyte specific reagents (ASRs); this diagnosis prompted an investigation of dairy products in two other states. Subsequent confirmatory antibody testing by Brucella microagglutination test (BMAT) performed at CDC on the patient's serum was negative. The case did not meet the CDC/Council of State and Territorial Epidemiologists' (CSTE) definition for a probable or confirmed brucellosis case, and the initial EIA result was determined to be a false positive. This report summarizes the case history, laboratory findings, and public health investigations. CDC recommends that Brucella serology testing only be performed using tests cleared or approved by the Food and Drug Administration (FDA) or validated under the Clinical Laboratory Improvement Amendments (CLIA) and shown to reliably detect the presence of Brucella infection. Results from these tests should be considered supportive evidence for recent infection only and interpreted in the context of a clinically compatible illness and exposure history. EIA is not considered a confirmatory Brucella antibody test; positive screening test results should be confirmed by Brucella-specific agglutination (i.e., BMAT or standard tube agglutination test) methods.

  1. Comparison of cumulative false-positive risk of screening mammography in the United States and Denmark

    DEFF Research Database (Denmark)

    Jacobsen, Katja Kemp

    2015-01-01

    INTRODUCTION: In the United States (US), about one-half of women screened with annual mammography have at least one false-positive test after ten screens. The estimate for European women screened ten times biennially is much lower. We evaluate to what extent screening interval, mammogram type......=400,204), between 1991-2012 and 1993-2013, respectively. Model-based cumulative false-positive risks were computed for the entire sample, using two statistical methods (Hubbard Njor) previously used to estimate false-positive risks in the US and Europe. RESULTS: Empirical cumulative risk of at least...... one false-positive test after eight (annual or biennial) screens was 41.9% in BCSC, 16.1% in Copenhagen, and 7.4% in Funen. Variation in screening interval and mammogram type did not explain the differences by country. Using the Hubbard method, the model-based cumulative risks after eight screens...

  2. Risk of breast cancer after false-positive results in mammographic screening.

    Science.gov (United States)

    Román, Marta; Castells, Xavier; Hofvind, Solveig; von Euler-Chelpin, My

    2016-06-01

    Women with false-positive results are commonly referred back to routine screening. Questions remain regarding their long-term outcome of breast cancer. We assessed the risk of screen-detected breast cancer in women with false-positive results. We conducted a joint analysis using individual level data from the population-based screening programs in Copenhagen and Funen in Denmark, Norway, and Spain. Overall, 150,383 screened women from Denmark (1991-2008), 612,138 from Norway (1996-2010), and 1,172,572 from Spain (1990-2006) were included. Poisson regression was used to estimate the relative risk (RR) of screen-detected cancer for women with false-positive versus negative results. We analyzed information from 1,935,093 women 50-69 years who underwent 6,094,515 screening exams. During an average 5.8 years of follow-up, 230,609 (11.9%) women received a false-positive result and 27,849 (1.4%) were diagnosed with screen-detected cancer. The adjusted RR of screen-detected cancer after a false-positive result was 2.01 (95% CI: 1.93-2.09). Women who tested false-positive at first screen had a RR of 1.86 (95% CI: 1.77-1.96), whereas those who tested false-positive at third screening had a RR of 2.42 (95% CI: 2.21-2.64). The RR of breast cancer at the screening test after the false-positive result was 3.95 (95% CI: 3.71-4.21), whereas it decreased to 1.25 (95% CI: 1.17-1.34) three or more screens after the false-positive result. Women with false-positive results had a twofold risk of screen-detected breast cancer compared to women with negative tests. The risk remained significantly higher three or more screens after the false-positive result. The increased risk should be considered when discussing stratified screening strategies. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  3. Psychological effects of false-positive results in expanded newborn screening in China.

    Directory of Open Access Journals (Sweden)

    Wen-Jun Tu

    Full Text Available OBJECTIVES: As more families participate expanded newborn screening for metabolic disorders in China, the overall number of false positives increases. Our goal was to assess the potential impact on parental stress, perceptions of the child's health, and family relationships. METHODS: Parents of 49 infants with false-positive screening results for metabolic disorders in the expanded newborn screening panel were compared with parents of 42 children with normal screening results. Parents first completed structured interview using likert scales, closed and open questions. Parents also completed the parenting stress index. RESULTS: A total of 88 mothers and 41 fathers were interviewed. More mothers in the false-positive group reported that their children required extra parental care (21%, compared with 5% of mothers in the normal-screened group (P<0.001. 39% of mothers in the false-positive group reported that they worry about their child's future development, compared with 10% of mothers in the normal-screened group (P<0.001. Fathers in the false-positive group did not differ from fathers in the normal-screened group in reporting worry about their child's extra care requirements, and their child's future development. Children with false-positive results compared with children with normal results were triple as likely to experience hospitalization (27%vs 9%, respectively; P<0.001. CONCLUSIONS: The results showing false-positive screening results may affect parental stress and the parent-child relationship. Parental stress and anxiety can be reduced with improved education and communication to parents about false-positive results.

  4. Is there a positive bias in false recognition? Evidence from confabulating amnesia patients.

    Science.gov (United States)

    Alkathiri, Nura H; Morris, Robin G; Kopelman, Michael D

    2015-10-01

    Although there is some evidence for a positive emotional bias in the content of confabulations in brain damaged patients, findings have been inconsistent. The present study used the semantic-associates procedure to induce false recall and false recognition in order to examine whether a positive bias would be found in confabulating amnesic patients, relative to non-confabulating amnesic patients and healthy controls. Lists of positive, negative and neutral words were presented in order to induce false recall or false recognition of non-presented (but semantically associated) words. The latter were termed 'critical intrusions'. Thirteen confabulating amnesic patients, 13 non-confabulating amnesic patients and 13 healthy controls were investigated. Confabulating patients falsely recognised a higher proportion of positive (but unrelated) words, compared with non-confabulating patients and healthy controls. No differences were found for recall memory. Signal detection analysis, however, indicated that the positive bias for false recognition memory might reflect weaker memory in the confabulating amnesic group. This suggested that amnesia patients with weaker memory are more likely to confabulate and the content of these confabulations are more likely to be positive. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Skin irritation, false positives and the local lymph node assay: a guideline issue?

    Science.gov (United States)

    Basketter, David A; Kimber, Ian

    2011-10-01

    Since the formal validation and regulatory acceptance of the local lymph node assay (LLNA) there have been commentaries suggesting that the irritant properties of substances can give rise to false positives. As toxicology aspires to progress rapidly towards the age of in vitro alternatives, it is of increasing importance that issues relating to assay selectivity and performance are understood fully, and that true false positive responses are distinguished clearly from those that are simply unpalatable. In the present review, we have focused on whether skin irritation per se is actually a direct cause of true false positive results in the LLNA. The body of published work has been examined critically and considered in relation to our current understanding of the mechanisms of skin irritation and skin sensitisation. From these analyses it is very clear that, of itself, skin irritation is not a cause of false positive results. The corollary is, therefore, that limiting test concentrations in the LLNA for the purpose of avoiding skin irritation may lead, unintentionally, to false negatives. Where a substance is a true false positive in the LLNA, the classic example being sodium lauryl sulphate, explanations for that positivity will have to reach beyond the seductive, but incorrect, recourse to its skin irritation potential. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Study of false positives in 5-ALA induced photodynamic diagnosis of bladder carcinoma

    Science.gov (United States)

    Draga, Ronald O. P.; Grimbergen, Matthijs C. M.; Kok, Esther T.; Jonges, Trudy G. N.; Bosch, J. L. H. R.

    2009-02-01

    Photodynamic diagnosis (PDD) is a technique that enhances the detection of tumors during cystoscopy using a photosensitizer which accumulates primarily in cancerous cells and will fluoresce when illuminated by violetblue light. A disadvantage of PDD is the relatively low specificity. In this retrospective study we aimed to identify predictors for false positive findings in PDD. Factors such as gender, age, recent transurethral resection of bladder tumors (TURBT), previous intravesical therapy (IVT) and urinary tract infections (UTIs) were examined for association with the false positive rates in a multivariate analysis. Data of 366 procedures and 200 patients were collected. Patients were instilled with 5-aminolevulinic acid (5-ALA) intravesically and 1253 biopsies were taken from tumors and suspicious lesions. Female gender and TURBT are independent predictors of false positives in PDD. However, previous intravesical therapy with Bacille Calmette-Guérin is also an important predictor of false positives. The false positive rate decreases during the first 9-12 weeks after the latest TURBT and the latest intravesical chemotherapy. Although shortly after IVT and TURBT false positives increase, PDD improves the diagnostic sensitivity and results in more adequate treatment strategies in a significant number of patients.

  7. Nuclear positioning rather than contraction controls ordered rearrangements of immunoglobulin loci

    NARCIS (Netherlands)

    M.B. Rother (Magdalena); R.-J.T.S. Palstra (Robert-Jan); S. Jhunjhunwala (Suchit); K.A.M. Van Kester (Kevin A. M.); W.F.J. van IJcken (Wilfred); R.W. Hendriks (Rudi); J.J.M. van Dongen (Jacques); C. Murre (Cornelis); M.C. van Zelm (Menno)

    2016-01-01

    textabstractProgenitor-B cells recombine their immunoglobulin (Ig) loci to create unique antigen receptors. Despite a common recombination machinery, the Ig heavy and Ig light chain loci rearrange in a stepwise manner. We studied pre-pro-B cells and Rag-/- progenitor-B cells to determine whether Ig

  8. The problem of false-positive human papillomavirus DNA tests in cervical screening

    DEFF Research Database (Denmark)

    Rebolj, Matejka; Pribac, Igor; Frederiksen, Maria Eiholm

    2013-01-01

    Human Papillomavirus (HPV) testing has been extensively studied in randomized controlled trials of primary cervical screening. Based on encouraging results concerning its high detection rates and a high negative predictive value for high-grade cervical intraepithelial neoplasia (CIN), HPV testing...... will probably replace cytology in future primary cervical screening. However, HPV testing is associated with more frequent false-positive tests compared to cytology. False-positive tests are defined as positive screening tests which are not subsequently confirmed with high-grade CIN. Several authors have...

  9. Performance quantification of clustering algorithms for false positive removal in fMRI by ROC curves

    Directory of Open Access Journals (Sweden)

    André Salles Cunha Peres

    Full Text Available Abstract Introduction Functional magnetic resonance imaging (fMRI is a non-invasive technique that allows the detection of specific cerebral functions in humans based on hemodynamic changes. The contrast changes are about 5%, making visual inspection impossible. Thus, statistic strategies are applied to infer which brain region is engaged in a task. However, the traditional methods like general linear model and cross-correlation utilize voxel-wise calculation, introducing a lot of false-positive data. So, in this work we tested post-processing cluster algorithms to diminish the false-positives. Methods In this study, three clustering algorithms (the hierarchical cluster, k-means and self-organizing maps were tested and compared for false-positive removal in the post-processing of cross-correlation analyses. Results Our results showed that the hierarchical cluster presented the best performance to remove the false positives in fMRI, being 2.3 times more accurate than k-means, and 1.9 times more accurate than self-organizing maps. Conclusion The hierarchical cluster presented the best performance in false-positive removal because it uses the inconsistency coefficient threshold, while k-means and self-organizing maps utilize a priori cluster number (centroids and neurons number; thus, the hierarchical cluster avoids clustering scattered voxels, as the inconsistency coefficient threshold allows only the voxels to be clustered that are at a minimum distance to some cluster.

  10. Assessment of potential false positives via orbitrap-based untargeted lipidomics from rat tissues.

    Science.gov (United States)

    Xu, Lina; Wang, Xueying; Jiao, Yupei; Liu, Xiaohui

    2018-02-01

    Untargeted lipidomics is increasingly popular due to the broad coverage of lipid species. Data dependent MS/MS acquisition is commonly used in order to acquire sufficient information for confident lipid assignment. However, although lipids are identified based on MS/MS confirmation, a number of false positives are still observed. Here, we discuss several causes of introducing lipid false identifications in untargeted analysis. Phosphotidylcholines and cholesteryl esters generate in-source fragmentation to produce dimethylated phosphotidylethanolamine and free cholesterol. Dimerization of fatty acid results in false identification of fatty acid ester of hydroxyl fatty acid. Realizing these false positives is able to improve confidence of results acquired from untargeted analysis. Besides, thresholds are established for lipids identified using LipidSearch v4.1.16 software to reduce unreliable results. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Reducing false positives of microcalcification detection systems by removal of breast arterial calcifications.

    Science.gov (United States)

    Mordang, Jan-Jurre; Gubern-Mérida, Albert; den Heeten, Gerard; Karssemeijer, Nico

    2016-04-01

    In the past decades, computer-aided detection (CADe) systems have been developed to aid screening radiologists in the detection of malignant microcalcifications. These systems are useful to avoid perceptual oversights and can increase the radiologists' detection rate. However, due to the high number of false positives marked by these CADe systems, they are not yet suitable as an independent reader. Breast arterial calcifications (BACs) are one of the most frequent false positives marked by CADe systems. In this study, a method is proposed for the elimination of BACs as positive findings. Removal of these false positives will increase the performance of the CADe system in finding malignant microcalcifications. A multistage method is proposed for the removal of BAC findings. The first stage consists of a microcalcification candidate selection, segmentation and grouping of the microcalcifications, and classification to remove obvious false positives. In the second stage, a case-based selection is applied where cases are selected which contain BACs. In the final stage, BACs are removed from the selected cases. The BACs removal stage consists of a GentleBoost classifier trained on microcalcification features describing their shape, topology, and texture. Additionally, novel features are introduced to discriminate BACs from other positive findings. The CADe system was evaluated with and without BACs removal. Here, both systems were applied on a validation set containing 1088 cases of which 95 cases contained malignant microcalcifications. After bootstrapping, free-response receiver operating characteristics and receiver operating characteristics analyses were carried out. Performance between the two systems was compared at 0.98 and 0.95 specificity. At a specificity of 0.98, the sensitivity increased from 37% to 52% and the sensitivity increased from 62% up to 76% at a specificity of 0.95. Partial areas under the curve in the specificity range of 0.8-1.0 were

  12. Evaluation of positive and false-positive results in syphilis screening of blood donors in Rio de Janeiro, Brazil.

    Science.gov (United States)

    Sandes, V S; Silva, S G C; Motta, I J F; Velarde, L G C; de Castilho, S R

    2017-06-01

    We propose to analyse the positive and false-positive results of treponemal and nontreponemal tests in blood donors from Brazil and to evaluate possible factors associated with the results of treponemal tests. Treponemal tests have been used widely for syphilis screening in blood banks. The introduction of these tests in donor screening has caused an impact and a loss of donors who need to be assessed. This was a retrospective cross-sectional study of syphilis screening and confirmatory test results of blood donors that were obtained before and after adopting a chemiluminescent immunoassay (CLIA). A comparative analysis was performed using a second sample drawn from positive donors. The possible factors associated with CLIA-positive or CLIA-false-positive results were investigated in a subgroup. Statistical tests were used to compare the proportions and adjusted estimates of association. The reactivity rate increased from 1·01% (N = 28 158) to 2·66% (N = 25 577) after introducing the new test. Among Venereal Disease Research Laboratory (VDRL)- and CLIA-confirmed results, the false-positive rates were 40·5% (N = 180) and 37·4% (N = 359), respectively (P = 0·5266). Older donors (OR = 1·04; P = 0·0010) and donors with lower education levels (OR = 6·59; P = 0·0029) were associated with a higher risk of positivity for syphilis. CLIA represents an improvement in blood bank serological screening. However, its use in a healthy population appears to result in high rates of false positives. Identifying which characteristics can predict false positives, however, remains a challenge. © 2017 British Blood Transfusion Society.

  13. Sherlock Holmes and child psychopathology assessment approaches: the case of the false-positive.

    Science.gov (United States)

    Jensen, P S; Watanabe, H

    1999-02-01

    To explore the relative value of various methods of assessing childhood psychopathology, the authors compared 4 groups of children: those who met criteria for one or more DSM diagnoses and scored high on parent symptom checklists, those who met psychopathology criteria on either one of these two assessment approaches alone, and those who met no psychopathology assessment criterion. Parents of 201 children completed the Child Behavior Checklist (CBCL), after which children and parents were administered the Diagnostic Interview Schedule for Children (version 2.1). Children and parents also completed other survey measures and symptom report inventories. The 4 groups of children were compared against "external validators" to examine the merits of "false-positive" and "false-negative" cases. True-positive cases (those that met DSM criteria and scored high on the CBCL) differed significantly from the true-negative cases on most external validators. "False-positive" and "false-negative" cases had intermediate levels of most risk factors and external validators. "False-positive" cases were not normal per se because they scored significantly above the true-negative group on a number of risk factors and external validators. A similar but less marked pattern was noted for "false-negatives." Findings call into question whether cases with high symptom checklist scores despite no formal diagnoses should be considered "false-positive." Pending the availability of robust markers for mental illness, researchers and clinicians must resist the tendency to reify diagnostic categories or to engage in arcane debates about the superiority of one assessment approach over another.

  14. False-positive buprenorphine EIA urine toxicology results due to high dose morphine: a case report.

    Science.gov (United States)

    Tenore, Peter L

    2012-01-01

    In monitoring a patient with chronic pain who was taking high-dose morphine and oxycodone with weekly urine enzymatic immunoassay (EIA) toxicology testing, the authors noted consistent positives for buprenorphine. The patient was not taking buprenorphine, and gas chromatography/mass spectroscopy (GCMS) testing on multiple samples revealed no buprenorphine, indicating a case of false-positive buprenorphine EIAs in a high-dose opiate case. The authors discontinued oxycodone for a period of time and then discontinued morphine. Urine monitoring with EIAs and GCMS revealed false-positive buprenorphine EIAs, which remained only when the patient was taking morphine. When taking only oxycodone and no morphine, urine samples became buprenorphine negative. When morphine was reintroduced, false-positive buprenorphine results resumed. Medical practitioners should be aware that high-dose morphine (with morphine urine levels turning positive within the 15,000 to 28,000 mg/mL range) may produce false-positive buprenorphine EIAs with standard urine EIA toxicology testing.

  15. Algorithm of reducing the false positives in IDS based on correlation Analysis

    Science.gov (United States)

    Liu, Jianyi; Li, Sida; Zhang, Ru

    2018-03-01

    This paper proposes an algorithm of reducing the false positives in IDS based on correlation Analysis. Firstly, the algorithm analyzes the distinguishing characteristics of false positives and real alarms, and preliminary screen the false positives; then use the method of attribute similarity clustering to the alarms and further reduces the amount of alarms; finally, according to the characteristics of multi-step attack, associated it by the causal relationship. The paper also proposed a reverse causation algorithm based on the attack association method proposed by the predecessors, turning alarm information into a complete attack path. Experiments show that the algorithm simplifies the number of alarms, improve the efficiency of alarm processing, and contribute to attack purposes identification and alarm accuracy improvement.

  16. Categorizing Mistaken False Positives in Regulation of Human and Environmental Health

    DEFF Research Database (Denmark)

    Hansen, Steffen Foss; Krayer von Krauss, Martin Paul; Tickner, J.A.

    2007-01-01

    One of the concerns often voiced by critics of the precautionary principle is that a widespread regulatory application of the principle will lead to a large number of false positives (i.e., over-regulation of minor risks and regulation of nonexisting risks). The present article proposes a general......," including: real risks, "The jury is still out," nonregulated proclaimed risks, "Too narrow a definition of risk," and risk-risk tradeoffs. These categories are defined and examples are presented in order to illustrate their key characteristics. On the basis of our analysis, we were able to identify only...... four cases that could be defined as regulatory false positives in the light of today's knowledge and recognized uncertainty: the Southern Corn Leaf Blight, the Swine Flu, Saccharin, and Food Irradiation in relation to consumer health. We conclude that concerns about false positives do not represent...

  17. Image Watermarking Scheme for Specifying False Positive Probability and Bit-pattern Embedding

    Science.gov (United States)

    Sayama, Kohei; Nakamoto, Masayoshi; Muneyasu, Mitsuji; Ohno, Shuichi

    This paper treats a discrete wavelet transform(DWT)-based image watermarking with considering the false positive probability and bit-pattern embedding. We propose an iterative embedding algorithm of watermarking signals which are K sets pseudo-random numbers generated by a secret key. In the detection, K correlations between the watermarked DWT coefficients and watermark signals are computed by using the secret key. L correlations are made available for the judgment of the watermark presence with specified false positive probability, and the other K-L correlations are corresponding to the bit-pattern signal. In the experiment, we show the detection results with specified false positive probability and the bit-pattern recovery, and the comparison of the proposed method against JPEG compression, scaling down and cropping.

  18. [Evaluation of performance and false positivity of Mediace RPR test that uses a chemistry autoanalyzer].

    Science.gov (United States)

    Noh, Jaekwang; Ko, Hak Hyun; Yun, Yeomin; Choi, Young Sook; Lee, Sang Gon; Shin, Sue; Han, Kyou Sup; Song, Eun Young

    2008-08-01

    We evaluated the performance and false positive rate of Mediace RPR test (Sekisui, Japan), a newly introduced nontreponemal test using a chemistry autoanalyzer. The sensitivity of Mediace RPR test was analyzed using sera from 50 patients with syphilis in different stages (8 primary, 7 secondary, and 35 latent), 14 sera positive with fluorescent treponemal antibody absorption (FTA-ABS) IgM, and 74 sera positive with conventional rapid plasma regain (RPR) card test (Asan, Korea) and also positive with Treponema pallidum hemagglutination (TPHA) test or FTA-ABS IgG test. The specificity was analyzed on 108 healthy blood donors. We also performed RPR card test on 302 sera that had been tested positive with Mediace RPR test and also performed TPHA or FTA-ABS IgG test to analyze the false positive rate of Mediace RPR test. A cutoff value of 0.5 R.U. (RPR unit) was used for Mediace RPR test. Mediace RPR test on syphilitic sera of different stages (primary, secondary, and latent stages) and FTA-ABS IgM positive sera showed a sensitivity of 100%, 100%, 82.9% and 100%, respectively. Among the 74 sera positive with conventional RPR card test and TPHA or FTA-ABS IgG test, 55 were positive with Mediace test. The specificity of Mediace RPR test on blood donors was 97.2%. Among the 302 sera positive with Mediace RPR test, 137 sera (45.4%) were negative by RPR card and TPHA/FTA-ABS IgG tests. Although the sensitivities of Mediace RPR were good for primary and secondary syphilis, due to its high negative rate of Mediace RPR over the conventional RPR positive samples, further studies are necessary whether it can replace conventional nontreponemal test for screening purpose. Moreover, in view of the high false positive rate, positive results by Mediace RPR test should be confirmed with treponemal tests.

  19. Newly formed skeletal muscle fibers are prone to false positive immunostaining by rabbit antibodies

    DEFF Research Database (Denmark)

    Andersen, Ditte C; Kliem, Anette; Schrøder, Henrik Daa

    2011-01-01

    rely on controls that reveal non-specific binding by the secondary antibody and neglect that the primary rabbit antibody itself may cause false positive staining of the muscle. We suggest that reliable immuno-based protein detection in newly formed muscle fibers at least requires a nonsense rabbit......Reports on muscle biology and regeneration often implicate immuno(cyto/histo)chemical protein characterization using rabbit polyclonal antibodies. In this study we demonstrate that newly formed myofibers are especially prone to false positive staining by rabbit antibodies and this unwanted staining...

  20. Potential for false positive HIV test results with the serial rapid HIV testing algorithm

    Directory of Open Access Journals (Sweden)

    Baveewo Steven

    2012-03-01

    Full Text Available Abstract Background Rapid HIV tests provide same-day results and are widely used in HIV testing programs in areas with limited personnel and laboratory infrastructure. The Uganda Ministry of Health currently recommends the serial rapid testing algorithm with Determine, STAT-PAK, and Uni-Gold for diagnosis of HIV infection. Using this algorithm, individuals who test positive on Determine, negative to STAT-PAK and positive to Uni-Gold are reported as HIV positive. We conducted further testing on this subgroup of samples using qualitative DNA PCR to assess the potential for false positive tests in this situation. Results Of the 3388 individuals who were tested, 984 were HIV positive on two consecutive tests, and 29 were considered positive by a tiebreaker (positive on Determine, negative on STAT-PAK, and positive on Uni-Gold. However, when the 29 samples were further tested using qualitative DNA PCR, 14 (48.2% were HIV negative. Conclusion Although this study was not primarily designed to assess the validity of rapid HIV tests and thus only a subset of the samples were retested, the findings show a potential for false positive HIV results in the subset of individuals who test positive when a tiebreaker test is used in serial testing. These findings highlight a need for confirmatory testing for this category of individuals.

  1. Potential for false positive HIV test results with the serial rapid HIV testing algorithm.

    Science.gov (United States)

    Baveewo, Steven; Kamya, Moses R; Mayanja-Kizza, Harriet; Fatch, Robin; Bangsberg, David R; Coates, Thomas; Hahn, Judith A; Wanyenze, Rhoda K

    2012-03-19

    Rapid HIV tests provide same-day results and are widely used in HIV testing programs in areas with limited personnel and laboratory infrastructure. The Uganda Ministry of Health currently recommends the serial rapid testing algorithm with Determine, STAT-PAK, and Uni-Gold for diagnosis of HIV infection. Using this algorithm, individuals who test positive on Determine, negative to STAT-PAK and positive to Uni-Gold are reported as HIV positive. We conducted further testing on this subgroup of samples using qualitative DNA PCR to assess the potential for false positive tests in this situation. Of the 3388 individuals who were tested, 984 were HIV positive on two consecutive tests, and 29 were considered positive by a tiebreaker (positive on Determine, negative on STAT-PAK, and positive on Uni-Gold). However, when the 29 samples were further tested using qualitative DNA PCR, 14 (48.2%) were HIV negative. Although this study was not primarily designed to assess the validity of rapid HIV tests and thus only a subset of the samples were retested, the findings show a potential for false positive HIV results in the subset of individuals who test positive when a tiebreaker test is used in serial testing. These findings highlight a need for confirmatory testing for this category of individuals.

  2. Reducing false positives of microcalcification detection systems by removal of breast arterial calcifications

    International Nuclear Information System (INIS)

    Mordang, Jan-Jurre; Gubern-Mérida, Albert; Karssemeijer, Nico; Heeten, Gerard den

    2016-01-01

    Purpose: In the past decades, computer-aided detection (CADe) systems have been developed to aid screening radiologists in the detection of malignant microcalcifications. These systems are useful to avoid perceptual oversights and can increase the radiologists’ detection rate. However, due to the high number of false positives marked by these CADe systems, they are not yet suitable as an independent reader. Breast arterial calcifications (BACs) are one of the most frequent false positives marked by CADe systems. In this study, a method is proposed for the elimination of BACs as positive findings. Removal of these false positives will increase the performance of the CADe system in finding malignant microcalcifications. Methods: A multistage method is proposed for the removal of BAC findings. The first stage consists of a microcalcification candidate selection, segmentation and grouping of the microcalcifications, and classification to remove obvious false positives. In the second stage, a case-based selection is applied where cases are selected which contain BACs. In the final stage, BACs are removed from the selected cases. The BACs removal stage consists of a GentleBoost classifier trained on microcalcification features describing their shape, topology, and texture. Additionally, novel features are introduced to discriminate BACs from other positive findings. Results: The CADe system was evaluated with and without BACs removal. Here, both systems were applied on a validation set containing 1088 cases of which 95 cases contained malignant microcalcifications. After bootstrapping, free-response receiver operating characteristics and receiver operating characteristics analyses were carried out. Performance between the two systems was compared at 0.98 and 0.95 specificity. At a specificity of 0.98, the sensitivity increased from 37% to 52% and the sensitivity increased from 62% up to 76% at a specificity of 0.95. Partial areas under the curve in the specificity

  3. Reducing false positives of microcalcification detection systems by removal of breast arterial calcifications

    Energy Technology Data Exchange (ETDEWEB)

    Mordang, Jan-Jurre, E-mail: Jan-Jurre.Mordang@radboudumc.nl; Gubern-Mérida, Albert; Karssemeijer, Nico [Diagnostic Image Analysis Group, Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen 6525 GA (Netherlands); Heeten, Gerard den [The National Training Centre for Breast Cancer Screening, Nijmegen 6503 GJ, The Netherlands and Department of Radiology, Amsterdam Medical Center, Amsterdam 1100 DD (Netherlands)

    2016-04-15

    Purpose: In the past decades, computer-aided detection (CADe) systems have been developed to aid screening radiologists in the detection of malignant microcalcifications. These systems are useful to avoid perceptual oversights and can increase the radiologists’ detection rate. However, due to the high number of false positives marked by these CADe systems, they are not yet suitable as an independent reader. Breast arterial calcifications (BACs) are one of the most frequent false positives marked by CADe systems. In this study, a method is proposed for the elimination of BACs as positive findings. Removal of these false positives will increase the performance of the CADe system in finding malignant microcalcifications. Methods: A multistage method is proposed for the removal of BAC findings. The first stage consists of a microcalcification candidate selection, segmentation and grouping of the microcalcifications, and classification to remove obvious false positives. In the second stage, a case-based selection is applied where cases are selected which contain BACs. In the final stage, BACs are removed from the selected cases. The BACs removal stage consists of a GentleBoost classifier trained on microcalcification features describing their shape, topology, and texture. Additionally, novel features are introduced to discriminate BACs from other positive findings. Results: The CADe system was evaluated with and without BACs removal. Here, both systems were applied on a validation set containing 1088 cases of which 95 cases contained malignant microcalcifications. After bootstrapping, free-response receiver operating characteristics and receiver operating characteristics analyses were carried out. Performance between the two systems was compared at 0.98 and 0.95 specificity. At a specificity of 0.98, the sensitivity increased from 37% to 52% and the sensitivity increased from 62% up to 76% at a specificity of 0.95. Partial areas under the curve in the specificity

  4. Hemorrhoids detected at colonoscopy: an infrequent cause of false-positive fecal immunochemical test results.

    NARCIS (Netherlands)

    Turenhout, S.T. van; Oort, F.A.; Terhaar sive Droste, J.S.; Coupe, V.M.; Hulst, R.W. van der; Loffeld, R.J.; Scholten, P.; Depla, A.C.; Bouman, A.A.; Meijer, G.A.; Mulder, C.J.; Rossum, L.G.M. van

    2012-01-01

    BACKGROUND: Colorectal cancer screening by fecal immunochemical tests (FITs) is hampered by frequent false-positive (FP) results and thereby the risk of complications and strain on colonoscopy capacity. Hemorrhoids might be a plausible cause of FP results. OBJECTIVE: To determine the contribution of

  5. IS HCI THAT IS USED AS A PRESERVATIVE CREATING FALSE POSITIVES FOR TBA IN GROUND WATER

    Science.gov (United States)

    Will hydrochloric acid produce false positives for TBA? Yes, if you heat the sample to get a lower detection limit for TBA. Conventional purge and trap methods at ambient temperature have a reporting limit for TBA between 50 and 100 g/liter. This is higher than the provisiona...

  6. False-Positive Rate of AKI Using Consensus Creatinine-Based Criteria.

    Science.gov (United States)

    Lin, Jennie; Fernandez, Hilda; Shashaty, Michael G S; Negoianu, Dan; Testani, Jeffrey M; Berns, Jeffrey S; Parikh, Chirag R; Wilson, F Perry

    2015-10-07

    Use of small changes in serum creatinine to diagnose AKI allows for earlier detection but may increase diagnostic false-positive rates because of inherent laboratory and biologic variabilities of creatinine. We examined serum creatinine measurement characteristics in a prospective observational clinical reference cohort of 2267 adult patients with AKI by Kidney Disease Improving Global Outcomes creatinine criteria and used these data to create a simulation cohort to model AKI false-positive rates. We simulated up to seven successive blood draws on an equal population of hypothetical patients with unchanging true serum creatinine values. Error terms generated from laboratory and biologic variabilities were added to each simulated patient's true serum creatinine value to obtain the simulated measured serum creatinine for each blood draw. We determined the proportion of patients who would be erroneously diagnosed with AKI by Kidney Disease Improving Global Outcomes creatinine criteria. Within the clinical cohort, 75.0% of patients received four serum creatinine draws within at least one 48-hour period during hospitalization. After four simulated creatinine measurements that accounted for laboratory variability calculated from assay characteristics and 4.4% of biologic variability determined from the clinical cohort and publicly available data, the overall false-positive rate for AKI diagnosis was 8.0% (interquartile range =7.9%-8.1%), whereas patients with true serum creatinine ≥1.5 mg/dl (representing 21% of the clinical cohort) had a false-positive AKI diagnosis rate of 30.5% (interquartile range =30.1%-30.9%) versus 2.0% (interquartile range =1.9%-2.1%) in patients with true serum creatinine values false-positive rates caused by inherent variability of serum creatinine at higher baseline values, potentially misclassifying patients with CKD in AKI studies. Copyright © 2015 by the American Society of Nephrology.

  7. Positive events protect children from causal false memories for scripted events.

    Science.gov (United States)

    Melinder, Annika; Toffalini, Enrico; Geccherle, Eleonora; Cornoldi, Cesare

    2017-11-01

    Adults produce fewer inferential false memories for scripted events when their conclusions are emotionally charged than when they are neutral, but it is not clear whether the same effect is also found in children. In the present study, we examined this issue in a sample of 132 children aged 6-12 years (mean 9 years, 3 months). Participants encoded photographs depicting six script-like events that had a positively, negatively, or a neutral valenced ending. Subsequently, true and false recognition memory of photographs related to the observed scripts was tested as a function of emotionality. Causal errors-a type of false memory thought to stem from inferential processes-were found to be affected by valence: children made fewer causal errors for positive than for neutral or negative events. Hypotheses are proposed on why adults were found protected against inferential false memories not only by positive (as for children) but also by negative endings when administered similar versions of the same paradigm.

  8. Shear-wave elastography in the diagnosis of solid breast masses: what leads to false-negative or false-positive results?

    Science.gov (United States)

    Yoon, Jung Hyun; Jung, Hae Kyoung; Lee, Jong Tae; Ko, Kyung Hee

    2013-09-01

    To investigate the factors that have an effect on false-positive or false-negative shear-wave elastography (SWE) results in solid breast masses. From June to December 2012, 222 breast lesions of 199 consecutive women (mean age: 45.3 ± 10.1 years; range, 21 to 88 years) who had been scheduled for biopsy or surgical excision were included. Greyscale ultrasound and SWE were performed in all women before biopsy. Final ultrasound assessments and SWE parameters (pattern classification and maximum elasticity) were recorded and compared with histopathology results. Patient and lesion factors in the 'true' and 'false' groups were compared. Of the 222 masses, 175 (78.8 %) were benign, and 47 (21.2 %) were malignant. False-positive rates of benign masses were significantly higher than false-negative rates of malignancy in SWE patterns, 36.6 % to 6.4 % (P masses, factors showing significance among false SWE features were lesion size, breast thickness and lesion depth (all P breast masses had SWE images of good quality. False SWE features were more significantly seen in benign masses. Lesion size, breast thickness and lesion depth have significance in producing false results, and this needs consideration in SWE image acquisition. • Shear-wave elastography (SWE) is widely used during breast imaging • At SWE, false-positive rates were significantly higher than false-negative rates • Larger size, breast thickness, depth and fair quality influences false-positive SWE features • Smaller size, larger breast thickness and depth influences false-negative SWE features.

  9. False positive reduction in protein-protein interaction predictions using gene ontology annotations

    Directory of Open Access Journals (Sweden)

    Lin Yen-Han

    2007-07-01

    Full Text Available Abstract Background Many crucial cellular operations such as metabolism, signalling, and regulations are based on protein-protein interactions. However, the lack of robust protein-protein interaction information is a challenge. One reason for the lack of solid protein-protein interaction information is poor agreement between experimental findings and computational sets that, in turn, comes from huge false positive predictions in computational approaches. Reduction of false positive predictions and enhancing true positive fraction of computationally predicted protein-protein interaction datasets based on highly confident experimental results has not been adequately investigated. Results Gene Ontology (GO annotations were used to reduce false positive protein-protein interactions (PPI pairs resulting from computational predictions. Using experimentally obtained PPI pairs as a training dataset, eight top-ranking keywords were extracted from GO molecular function annotations. The sensitivity of these keywords is 64.21% in the yeast experimental dataset and 80.83% in the worm experimental dataset. The specificities, a measure of recovery power, of these keywords applied to four predicted PPI datasets for each studied organisms, are 48.32% and 46.49% (by average of four datasets in yeast and worm, respectively. Based on eight top-ranking keywords and co-localization of interacting proteins a set of two knowledge rules were deduced and applied to remove false positive protein pairs. The 'strength', a measure of improvement provided by the rules was defined based on the signal-to-noise ratio and implemented to measure the applicability of knowledge rules applying to the predicted PPI datasets. Depending on the employed PPI-predicting methods, the strength varies between two and ten-fold of randomly removing protein pairs from the datasets. Conclusion Gene Ontology annotations along with the deduced knowledge rules could be implemented to partially

  10. False positive seroreactivity to brucellosis in tuberculosis patients: a prevalence study

    Directory of Open Access Journals (Sweden)

    Mojtaba Varshochi

    2011-03-01

    Full Text Available Mojtaba Varshochi1,2, Jafar Majidi2, Marjan Amini1, Kamyar Ghabili3, Mohammadali M Shoja31Department of Infectious Disease, Tabriz University of Medical Sciences, Tabriz, Iran; 2Infectious Disease and Tropical Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 3Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IranBackground: The rising worldwide incidence of tuberculosis (TB increases the demand for knowledge about its potential seroreactivity with other microbial agents. A few reports and the authors’ experiences indicate that tuberculosis may result in a false-positive brucellosis serology. This may cause a diagnostic challenge because of the close clinical resemblance of these two infections.Objective: The aim of the present prevalence study was to elucidate brucellosis seroreactivity in patients with active TB.Methods: Ninety-eight patients with newly diagnosed and active TB were studied using an enzyme-linked immunosorbent assay (ELISA and Wright’s and Coombs–Wright’s tests. Seventy-five healthy individuals were used as controls. The patients showed signs of recovery after starting a standard anti-TB regimen and had no clinical evidence of brucellosis at a subsequent 6-month follow-up. The data were analyzed statistically by Fisher’s exact test using SPSS 11.0.Results: We found that 9.2% of TB patients versus 1.3% of healthy controls had positive results on the anti-Brucella IgG ELISA (P = 0.04. Five TB patients were found to have agglutination on Wright’s tests, while none of the controls showed agglutination.Conclusion: Active TB patients may have some seroreactivity with Brucella antigens, and Brucella IgG ELISA may give a false positive in these patients. Clinicians should consider false positive brucellosis seroreactivity in patients with active TB.Keywords: false positive serology, ELISA, diagnosis

  11. Waiting time and the psychosocial consequences of false-positive mammography

    DEFF Research Database (Denmark)

    Heleno, Bruno M.; Siersma, Volkert; Brodersen, John

    2015-01-01

    Background: There is wide variation in the psychosocial response to false-positive mammography. We aimed to assess whether women having to wait longer to exclude cancer had increased psychosocial consequences that persisted after cancer was ruled out. Findings: We selected women with false......-positive mammography (n = 272), screened for breast cancer in Copenhagen and Funen (Denmark) over a 1-year period. We measured psychosocial consequences immediately before women attended their recall visit and 1, 6, 18 and 36 months after women received their final diagnosis. After women were told that cancer had been...... ruled out, adverse psychosocial consequences decreased with time. We found no statistically significant differences between women who had cancer ruled out immediately at the recall visit (waiting time of 0) and women who had to wait longer before cancer was ruled out (waiting times 1-30, 30...

  12. Long-term psychosocial consequences of false-positive screening mammography

    DEFF Research Database (Denmark)

    Brodersen, John; Siersma, Volkert Dirk

    2013-01-01

    Cancer screening programs have the potential of intended beneficial effects, but they also inevitably have unintended harmful effects. In the case of screening mammography, the most frequent harm is a false-positive result. Prior efforts to measure their psychosocial consequences have been limite...... by short-term follow-up, the use of generic survey instruments, and the lack of a relevant benchmark-women with breast cancer....

  13. Cross-reactive Carbohydrate Determinant Contributes to the False Positive IgE Antibody to Peanut

    Directory of Open Access Journals (Sweden)

    Komei Ito

    2005-01-01

    Conclusions: Social education about the features of peanut allergy is needed in Japan. Anti-CCD IgE antibody was suggested to be one of the mechanisms contributing to the false positive detection of peanut IgE. Detection of anti-HRP or anti-bromelain IgE can be a useful tool to recognize the presence of anti-CCD antibodies.

  14. Shape based automated detection of pulmonary nodules with surface feature based false positive reduction

    International Nuclear Information System (INIS)

    Nomura, Y.; Itoh, H.; Masutani, Y.; Ohtomo, K.; Maeda, E.; Yoshikawa, T.; Hayashi, N.

    2007-01-01

    We proposed a shape based automated detection of pulmonary nodules with surface feature based false positive (FP) reduction. In the proposed system, the FP existing in internal of vessel bifurcation is removed using extracted surface of vessels and nodules. From the validation with 16 chest CT scans, we find that the proposed CAD system achieves 18.7 FPs/scan at 90% sensitivity, and 7.8 FPs/scan at 80% sensitivity. (orig.)

  15. False-positive indium-111 labeled leukocyte scintigram in a patient with a painful hip prosthesis

    International Nuclear Information System (INIS)

    Feldman, N.; Makler, P.T. Jr.; Alavi, A.

    1986-01-01

    A Tronzo hip prosthesis is designed to elicit an inflammatory reaction in order to promote prosthesis stability. A three-phased bone scan and Ga-67 imaging in conjunction with physical examination and laboratory findings failed to demonstrate evidence for osteomyelitis in a patient with a painful hip prosthesis, in whom images obtained with In-111-labeled leukocytes were positive. This observation demonstrated that the interpretation of the latter technique in demonstrating inflammation can cause a false impression of an infectious process

  16. Heterophilic antibodies interfering with radioimmunoassay. A false-positive pregnancy test

    Energy Technology Data Exchange (ETDEWEB)

    Vladutiu, A.O.; Sulewski, J.M.; Pudlak, K.A.; Stull, C.G.

    1982-11-19

    A young woman with amenorrhea had a consistently positive pregnancy test result (serum radioimmunoassay measurement of ..beta..-human chorionic gonadotropin hormone). No fetal or placental tissue was found after uterine curettage and exploratory laparotomy. The false-positive pregnancy test result was due to heterophilic antibovine and antigoat antibodies in the patient's serum. These antibodies interfered with radioimmunoassays using goat antibodies. This case shows that serum heterophilic antibodies can interfere with immunoassays and result in unnecessary diagnostic procedures and/or unnecessary treatment.

  17. Heterophilic antibodies interfering with radioimmunoassay. A false-positive pregnancy test

    International Nuclear Information System (INIS)

    Vladutiu, A.O.; Sulewski, J.M.; Pudlak, K.A.; Stull, C.G.

    1982-01-01

    A young woman with amenorrhea had a consistently positive pregnancy test result (serum radioimmunoassay measurement of #betta#-human chorionic gonadotropin hormone). No fetal or placental tissue was found after uterine curettage and exploratory laparotomy. The false-positive pregnancy test result was due to heterophilic antibovine and antigoat antibodies in the patient's serum. These antibodies interfered with radioimmunoassays using goat antibodies. This case shows that serum heterophilic antibodies can interfere with immunoassays and result in unnecessary diagnostic procedures and/or unnecessary treatment

  18. Multilevel Contextual 3-D CNNs for False Positive Reduction in Pulmonary Nodule Detection.

    Science.gov (United States)

    Dou, Qi; Chen, Hao; Yu, Lequan; Qin, Jing; Heng, Pheng-Ann

    2017-07-01

    False positive reduction is one of the most crucial components in an automated pulmonary nodule detection system, which plays an important role in lung cancer diagnosis and early treatment. The objective of this paper is to effectively address the challenges in this task and therefore to accurately discriminate the true nodules from a large number of candidates. We propose a novel method employing three-dimensional (3-D) convolutional neural networks (CNNs) for false positive reduction in automated pulmonary nodule detection from volumetric computed tomography (CT) scans. Compared with its 2-D counterparts, the 3-D CNNs can encode richer spatial information and extract more representative features via their hierarchical architecture trained with 3-D samples. More importantly, we further propose a simple yet effective strategy to encode multilevel contextual information to meet the challenges coming with the large variations and hard mimics of pulmonary nodules. The proposed framework has been extensively validated in the LUNA16 challenge held in conjunction with ISBI 2016, where we achieved the highest competition performance metric (CPM) score in the false positive reduction track. Experimental results demonstrated the importance and effectiveness of integrating multilevel contextual information into 3-D CNN framework for automated pulmonary nodule detection in volumetric CT data. While our method is tailored for pulmonary nodule detection, the proposed framework is general and can be easily extended to many other 3-D object detection tasks from volumetric medical images, where the targeting objects have large variations and are accompanied by a number of hard mimics.

  19. A deep 3D residual CNN for false-positive reduction in pulmonary nodule detection.

    Science.gov (United States)

    Jin, Hongsheng; Li, Zongyao; Tong, Ruofeng; Lin, Lanfen

    2018-05-01

    The automatic detection of pulmonary nodules using CT scans improves the efficiency of lung cancer diagnosis, and false-positive reduction plays a significant role in the detection. In this paper, we focus on the false-positive reduction task and propose an effective method for this task. We construct a deep 3D residual CNN (convolution neural network) to reduce false-positive nodules from candidate nodules. The proposed network is much deeper than the traditional 3D CNNs used in medical image processing. Specifically, in the network, we design a spatial pooling and cropping (SPC) layer to extract multilevel contextual information of CT data. Moreover, we employ an online hard sample selection strategy in the training process to make the network better fit hard samples (e.g., nodules with irregular shapes). Our method is evaluated on 888 CT scans from the dataset of the LUNA16 Challenge. The free-response receiver operating characteristic (FROC) curve shows that the proposed method achieves a high detection performance. Our experiments confirm that our method is robust and that the SPC layer helps increase the prediction accuracy. Additionally, the proposed method can easily be extended to other 3D object detection tasks in medical image processing. © 2018 American Association of Physicists in Medicine.

  20. Clinical evaluation of false-positive scintigraphic lesions of the left lobe in portal hypertension

    International Nuclear Information System (INIS)

    Takayasu, Kenichi; Moriyama, Noriyuki; Suzuki, Masao; Yamada, Tatsuya; Fukutake, Toshio.

    1982-01-01

    sup(99m)Tc-phytate liver scan and percutaneous transhepatic portography (PTP) were performed in 33 patients with portal hypertension due to various hepatic diseases. A defect or space occupying lesion in the left lobe on the scan in these patients was analysed with reference to portographic changes of the pars umbilicus of the left portal vein and the following results were obtained. 1) A false-positive defect on the scintigram was found in 6 (18.2%) of 33 patients, and portal vein pressure (PVP) was above 200 mmH 2 O in all 6 which constituted 21.4% of 28 with PVP above 200 mmH 2 O. 2) In five out of 6 patients with false-positive scan findings, the pars umbilicus was dilated to more than 25 x 15 mm in size, and it was huge and tortuous in 3 of them. 3) The mean PVP in the group with a false-positive scan tended to be higher than that in patients with no abnormalities on the scintigram. It was concluded that in reading of liver scintigrams in patients with portal hypertension, a dilated pars umbilicus and huge para-umbilical vein should be considered. (author)

  1. Proteins interacting with cloning scars: a source of false positive protein-protein interactions.

    Science.gov (United States)

    Banks, Charles A S; Boanca, Gina; Lee, Zachary T; Florens, Laurence; Washburn, Michael P

    2015-02-23

    A common approach for exploring the interactome, the network of protein-protein interactions in cells, uses a commercially available ORF library to express affinity tagged bait proteins; these can be expressed in cells and endogenous cellular proteins that copurify with the bait can be identified as putative interacting proteins using mass spectrometry. Control experiments can be used to limit false-positive results, but in many cases, there are still a surprising number of prey proteins that appear to copurify specifically with the bait. Here, we have identified one source of false-positive interactions in such studies. We have found that a combination of: 1) the variable sequence of the C-terminus of the bait with 2) a C-terminal valine "cloning scar" present in a commercially available ORF library, can in some cases create a peptide motif that results in the aberrant co-purification of endogenous cellular proteins. Control experiments may not identify false positives resulting from such artificial motifs, as aberrant binding depends on sequences that vary from one bait to another. It is possible that such cryptic protein binding might occur in other systems using affinity tagged proteins; this study highlights the importance of conducting careful follow-up studies where novel protein-protein interactions are suspected.

  2. Analyzing false positives of four questions in the Force Concept Inventory

    Science.gov (United States)

    Yasuda, Jun-ichiro; Mae, Naohiro; Hull, Michael M.; Taniguchi, Masa-aki

    2018-06-01

    In this study, we analyze the systematic error from false positives of the Force Concept Inventory (FCI). We compare the systematic errors of question 6 (Q.6), Q.7, and Q.16, for which clearly erroneous reasoning has been found, with Q.5, for which clearly erroneous reasoning has not been found. We determine whether or not a correct response to a given FCI question is a false positive using subquestions. In addition to the 30 original questions, subquestions were introduced for Q.5, Q.6, Q.7, and Q.16. This modified version of the FCI was administered to 1145 university students in Japan from 2015 to 2017. In this paper, we discuss our finding that the systematic errors of Q.6, Q.7, and Q.16 are much larger than that of Q.5 for students with mid-level FCI scores. Furthermore, we find that, averaged over the data sample, the sum of the false positives from Q.5, Q.6, Q.7, and Q.16 is about 10% of the FCI score of a midlevel student.

  3. Improving computer-aided detection assistance in breast cancer screening by removal of obviously false-positive findings

    NARCIS (Netherlands)

    Mordang, Jan-Jurre; Gubern-Merida, Albert; Bria, Alessandro; Tortorella, Francesco; den Heeten, Gerard; Karssemeijer, Nico

    2017-01-01

    Purpose: Computer-aided detection (CADe) systems for mammography screening still mark many false positives. This can cause radiologists to lose confidence in CADe, especially when many false positives are obviously not suspicious to them. In this study, we focus on obvious false positives generated

  4. Improving computer-aided detection assistance in breast cancer screening by removal of obviously false-positive findings

    NARCIS (Netherlands)

    Mordang, J.J.; Gubern Merida, A.; Bria, A.; Tortorella, F.; Heeten, G.; Karssemeijer, N.

    2017-01-01

    PURPOSE: Computer-aided detection (CADe) systems for mammography screening still mark many false positives. This can cause radiologists to lose confidence in CADe, especially when many false positives are obviously not suspicious to them. In this study, we focus on obvious false positives generated

  5. Reduction of false-positive recalls using a computerized mammographic image feature analysis scheme

    Science.gov (United States)

    Tan, Maxine; Pu, Jiantao; Zheng, Bin

    2014-08-01

    The high false-positive recall rate is one of the major dilemmas that significantly reduce the efficacy of screening mammography, which harms a large fraction of women and increases healthcare cost. This study aims to investigate the feasibility of helping reduce false-positive recalls by developing a new computer-aided diagnosis (CAD) scheme based on the analysis of global mammographic texture and density features computed from four-view images. Our database includes full-field digital mammography (FFDM) images acquired from 1052 recalled women (669 positive for cancer and 383 benign). Each case has four images: two craniocaudal (CC) and two mediolateral oblique (MLO) views. Our CAD scheme first computed global texture features related to the mammographic density distribution on the segmented breast regions of four images. Second, the computed features were given to two artificial neural network (ANN) classifiers that were separately trained and tested in a ten-fold cross-validation scheme on CC and MLO view images, respectively. Finally, two ANN classification scores were combined using a new adaptive scoring fusion method that automatically determined the optimal weights to assign to both views. CAD performance was tested using the area under a receiver operating characteristic curve (AUC). The AUC = 0.793  ±  0.026 was obtained for this four-view CAD scheme, which was significantly higher at the 5% significance level than the AUCs achieved when using only CC (p = 0.025) or MLO (p = 0.0004) view images, respectively. This study demonstrates that a quantitative assessment of global mammographic image texture and density features could provide useful and/or supplementary information to classify between malignant and benign cases among the recalled cases, which may eventually help reduce the false-positive recall rate in screening mammography.

  6. False-Positive TDxFLx urine Amphetamine/Metamphetamine II assay from Ofloxacin

    International Nuclear Information System (INIS)

    Nomier, Mahmoud A.; Al-Huseini, Hani K.

    2004-01-01

    Immunoassays are widely used in testing urine for illicit drugs. Ofloaxcin and a number of other quinolones were found to induce false-positive opiates (OP) urine immunoassays. This can result in misleading conclusions in the concept of drug abuse The aim of present study was to evaluate the effects of ofloxacin in theraputic doses on the induction of false-positive urine immunoassays for common drugs of abuse in healthy male volunteers. The study was conducted on 6 healthy male volunteers, aging between 35-45 years. Two doses of 400 mg ofloxacin each, were given orally to each volunteer at 12 hours interval and urine samples were collected before ofloaxcin administration and 5-7.5 hours after the second dose. Urine samples were subjected for OP, amphetamine/methamphetamine II (AM/MA II), cocaine and cannabinoids assays on TDxFLx analyzer. Ofloxacin produced significant increase (P cutoff) for AM/MA II assays, were found in all volunteers after ofloaxcin administration. The study recomends strongly the confirmation of positive urine immunoassay results for drugs of abuseby a more specific methodology e.g. gas chromatography/ mass spectroscopy (GC/MS). (author)

  7. Prenatal ultrasound screening: false positive soft markers may alter maternal representations and mother-infant interaction.

    Directory of Open Access Journals (Sweden)

    Sylvie Viaux-Savelon

    Full Text Available In up to 5% of pregnancies, ultrasound screening detects a "soft marker" (SM that places the foetus at risk for a severe abnormality. In most cases, prenatal diagnostic work-up rules out a severe defect. We aimed to study the effects of false positive SM on maternal emotional status, maternal representations of the infant, and mother-infant interaction.Utilizing an extreme-case prospective case control design, we selected from a group of 244 women undergoing ultrasound, 19 pregnant women whose foetus had a positive SM screening and a reassuring diagnostic work up, and 19 controls without SM matched for age and education. In the third trimester of pregnancy, within one week after delivery, and 2 months postpartum, we assessed anxiety, depression, and maternal representations. Mother-infant interactions were videotaped during feeding within one week after delivery and again at 2 months postpartum and coded blindly using the Coding Interactive Behavior (CIB scales. Anxiety and depression scores were significantly higher at all assessment points in the SM group. Maternal representations were also different between SM and control groups at all study time. Perturbations to early mother-infant interactions were observed in the SM group. These dyads showed greater dysregulation, lower maternal sensitivity, higher maternal intrusive behaviour and higher infant avoidance. Multivariate analysis showed that maternal representation and depression at third trimester predicted mother-infant interaction.False positive ultrasound screenings for SM are not benign and negatively affect the developing maternal-infant attachment. Medical efforts should be directed to minimize as much as possible such false diagnoses, and to limit their psychological adverse consequences.

  8. Center not liable for defamation from false-positive hepatitis test.

    Science.gov (United States)

    1997-04-18

    The Nebraska Court of Appeals ruled that [name removed] does not have a cause of action against the Lincoln Plasma Center in Lincoln, NE. The center blacklisted him as a carrier of hepatitis B virus; subsequent tests proved [name removed] was uninfected. [Name removed], a paid plasma donator, was placed on an ineligible list after he tested positive for the hepatitis B surface antigen. [Name removed] sued, alleging that Lincoln defamed him by publishing false information to blood banks about his eligibility to donate. The Court of Appeals upheld a trial court's directed verdict because there was no evidence that the plasma center acted in malice.

  9. Suture Granuloma Showing False-Positive Findings on FDG-PET

    Directory of Open Access Journals (Sweden)

    Kohei Takahara

    2013-01-01

    Full Text Available We report a case of a 33-year-old male with a mixed germ-cell testicular tumor. Postoperative follow-up FDG-PET revealed concentration of FDG in the left inguinal area which is not tumor metastasis or local recurrence but suture reactivity granuloma. In this paper, we reviewed suture granulomas associated with false-positive findings on FDG-PET after surgery. If FDG-PET will be used more frequently in the future, it will be necessary to refrain from using silk thread in order to prevent any unnecessary surgery.

  10. False positive indium-111 white blood cell scan in a closed clavicle fracture

    International Nuclear Information System (INIS)

    Friedman, R.J.; Gordon, L.

    1988-01-01

    Aggressive treatment of the multiply injured patient often requires early fixation of many fractures, some of which may be open. Often, patients develop postoperative fevers requiring a thorough workup to rule out infection. Recently, indium-111 white blood cell (WBC) imaging has become a valuable adjunct in the diagnosis of acute infection. The patient described had a simple, closed clavicle fracture with markedly increased activity on an indium-111 WBC scan obtained for fever workup. This subsequently proved to be a normal, healing, noninfected fracture by other diagnostic techniques. Noninfected, simple closed fractures should be added to the list of causes for a false-positive indium-111 WBC scan

  11. False-positive reduction in CAD mass detection using a competitive classification strategy

    International Nuclear Information System (INIS)

    Li Lihua; Zheng Yang; Zhang Lei; Clark, Robert A.

    2001-01-01

    High false-positive (FP) rate remains to be one of the major problems to be solved in CAD study because too many false-positively cued signals will potentially degrade the performance of detecting true-positive regions and increase the call-back rate in CAD environment. In this paper, we proposed a novel classification method for FP reduction, where the conventional 'hard' decision classifier is cascaded with a 'soft' decision classification with the objective to reduce false-positives in the cases with multiple FPs retained after the 'hard' decision classification. The 'soft' classification takes a competitive classification strategy in which only the 'best' ones are selected from the pre-classified suspicious regions as the true mass in each case. A neural network structure is designed to implement the proposed competitive classification. Comparative studies of FP reduction on a database of 79 images by a 'hard' decision classification and a combined 'hard'-'soft' classification method demonstrated the efficiency of the proposed classification strategy. For example, for the high FP sub-database which has only 31.7% of total images but accounts for 63.5% of whole FPs generated in single 'hard' classification, the FPs can be reduced for 56% (from 8.36 to 3.72 per image) by using the proposed method at the cost of 1% TP loss (from 69% to 68%) in whole database, while it can only be reduced for 27% (from 8.36 to 6.08 per image) by simply increasing the threshold of 'hard' classifier with a cost of TP loss as high as 14% (from 69% to 55%). On the average in whole database, the FP reduction by hybrid 'hard'-'soft' classification is 1.58 per image as compared to 1.11 by 'hard' classification at the TP costs described above. Because the cases with high dense tissue are of higher risk of cancer incidence and false-negative detection in mammogram screening, and usually generate more FPs in CAD detection, the method proposed in this paper will be very helpful in improving

  12. PIPIDA scintigraphy for cholecystitis: false positives in alcoholism and total parenteral nutrition

    International Nuclear Information System (INIS)

    Shuman, W.P.; Gibbs, P.; Rudd, T.G.; Mack, L.A.

    1982-01-01

    A review of gallbladder scintigraphy in patients with potentially compromised hepatobiliary function revealed two groups in whom cholecystitis might be mistakenly diagnosed. In 200 consecutive hospitalized patients studied with technetium-99m-PIPIDA for acute cholecystitis or cholestasis, there were 41 alcoholics and 17 patients on total parenteral nutrition. In 60% of the alcoholics and 92% of those on parenteral nutrition, absent or delayed visualization of the gallbladder occurred without physical or clinical evidence of cholecystitis. A cholecystagogue, sincalide, did not prevent the false-positive features which presumably are due to altered bile flow kinetics related to alcoholism and parenteral nutrition. Four patients on parenteral nutrition undergoing cholecystectomy for suspected cholecystitis had normal gallbladders filled with jellylike viscous thick bile. A positive (nonvisualized or delayed visualized) gallbladder PIPIDA scintigram in these two populations should not be interpreted as indicating a need for cholecystectomy

  13. Buffer substitution in malaria rapid diagnostic tests causes false-positive results

    Directory of Open Access Journals (Sweden)

    Van den Ende Jef

    2010-07-01

    Full Text Available Abstract Background Malaria rapid diagnostic tests (RDTs are kits that generally include 20 to 25 test strips or cassettes, but only a single buffer vial. In field settings, laboratory staff occasionally uses saline, distilled water (liquids for parenteral drugs dilution or tap water as substitutes for the RDT kit's buffer to compensate for the loss of a diluent bottle. The present study assessed the effect of buffer substitution on the RDT results. Methods Twenty-seven RDT brands were run with EDTA-blood samples of five malaria-free subjects, who were negative for rheumatoid factor and antinuclear antibodies. Saline, distilled water and tap water were used as substitute liquids. RDTs were also run with distilled water, without adding blood. Results were compared to those obtained with the RDT kit's buffer and Plasmodium positive samples. Results Only eight cassettes (in four RDT brands showed no control line and were considered invalid. Visible test lines occurred for at least one malaria-free sample and one of the substitutes in 20/27 (74% RDT brands (saline: n = 16; distilled water: n = 17; and tap water: n = 20, and in 15 RDTs which were run with distilled water only. They occurred for all Plasmodium antigens and RDT formats (two-, three- and four-band RDTs. Clearance of the background of the strip was excellent except for saline. The aspects (colour, intensity and crispness of the control and the false-positive test lines were similar to those obtained with the RDT kits' buffer and Plasmodium positive samples. Conclusion Replacement of the RDT kit's dedicated buffer by saline, distilled water and tap water can cause false-positive test results.

  14. False positive rate of carbon monoxide saturation by pulse oximetry of emergency department patients.

    Science.gov (United States)

    Weaver, Lindell K; Churchill, Susan K; Deru, Kayla; Cooney, Darryl

    2013-02-01

    Symptoms of carbon monoxide (CO) poisoning are non-specific. Diagnosis requires suspicion of exposure, confirmed by measuring ambient CO levels or carboxyhemoglobin (COHb). An FDA-approved pulse oximeter (Rad-57) can measure CO saturation (S(pCO)). The device accuracy has implications for clinical decision-making. From April 1 to August 15, 2008, study personnel measured S(pCO) and documented demographic factors at time of clinical blood draw, in a convenience sample of 1,363 subjects presenting to the emergency department at Intermountain Medical Center, Murray, Utah. The technician then assayed COHb. COHb and S(pCO) values were compared by subject; false positive or negative values were defined as S(pCO) at least 3 percentage points greater or less than COHb level, reported by the manufacturer to be ± 1 SD in performance. In 1,363 subjects, 613 (45%) were male, 1,141 (84%) were light-skinned, 14 in shock, 4 with CO poisoning, and 122 (9%) met the criteria for a false positive value (range 3-19 percentage points), while 247 (18%) met the criteria for a false negative value (-13 to -3 percentage points). Risks for a false positive S(pCO) reading included being female and having a lower perfusion index. Methemoglobin, body temperature, and blood pressure also appear to influence the S(pCO) accuracy. There was variability among monitors, possibly related to technician technique, as rotation of monitors among technicians was not enforced. While the Rad-57 pulse oximeter functioned within the manufacturer's specifications, clinicians using the Rad-57 should expect some S(pCO) readings to be significantly higher or lower than COHb measurements, and should not use S(pCO) to direct triage or patient management. An elevated S(pCO) could broaden the diagnosis of CO poisoning in patients with non-specific symptoms. However, a negative S(pCO) level in patients suspected of having CO poisoning should never rule out CO poisoning, and should always be confirmed by COHb. © 2013

  15. Reporting instructions significantly impact false positive rates when reading chest radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, John W.; Brennan, Patrick C.; Mello-Thoms, Claudia; Lewis, Sarah J. [The University of Sydney, Medical Image Optimisation and Perception Group, Discipline of Medical Radiation Sciences, Faculty of Health Sciences, Lidcombe, NSW (Australia)

    2016-10-15

    To determine the impact of specific reporting tasks on the performance of radiologists when reading chest radiographs. Ten experienced radiologists read a set of 40 postero-anterior (PA) chest radiographs: 21 nodule free and 19 with a proven solitary nodule. There were two reporting conditions: an unframed task (UFT) to report any abnormality and a framed task (FT) reporting only lung nodule/s. Jackknife free-response operating characteristic (JAFROC) figure of merit (FOM), specificity, location sensitivity and number of true positive (TP), false positive (FP), true negative (TN) and false negative (FN) decisions were used for analysis. JAFROC FOM for tasks showed a significant reduction in performance for framed tasks (P = 0.006) and an associated decrease in specificity (P = 0.011) but no alteration to the location sensitivity score. There was a significant increase in number of FP decisions made during framed versus unframed tasks for nodule-containing (P = 0.005) and nodule-free (P = 0.011) chest radiographs. No significant differences in TP were recorded. Radiologists report more FP decisions when given specific reporting instructions to search for nodules on chest radiographs. The relevance of clinical history supplied to radiologists is called into question and may induce a negative effect. (orig.)

  16. A high false positive rate for Kepler planetary candidates of giant stars using asterodensity profiling

    International Nuclear Information System (INIS)

    Sliski, David H.; Kipping, David M.

    2014-01-01

    Asterodensity profiling (AP) is a relatively new technique for studying transit light curves. By comparing the mean stellar density derived from the transit light curve to that found through an independent method, AP provides information on several useful properties such as orbital eccentricity and blended light. We present an AP survey of 41 Kepler Objects of Interest (KOIs), with a single transiting candidate, for which the target star's mean stellar density has been measured using asteroseismology. The ensemble distribution of the AP measurements for the 31 dwarf stars in our sample shows excellent agreement with the spread expected if the KOIs were genuine and have realistic eccentricities. In contrast, the same test for the 10 giants in our sample reveals significant incompatibility at >4σ confidence. While extreme eccentricities could be invoked, this hypothesis requires four of the KOIs to contact their host star at periastron passage, including the recently claimed confirmation of Kepler-91b. After carefully examining several hypotheses, we conclude that the most plausible explanation is that the transiting objects orbit a different star to that measured with asteroseismology—cases we define as false-positives. Based on the AP distribution, we estimate a false-positive rate (FPR) for Kepler's giant stars with a single transiting object of FPR ≅ 70% ± 30%.

  17. Robust Correlation Analyses: False Positive and Power Validation Using a New Open Source Matlab Toolbox

    Science.gov (United States)

    Pernet, Cyril R.; Wilcox, Rand; Rousselet, Guillaume A.

    2012-01-01

    Pearson’s correlation measures the strength of the association between two variables. The technique is, however, restricted to linear associations and is overly sensitive to outliers. Indeed, a single outlier can result in a highly inaccurate summary of the data. Yet, it remains the most commonly used measure of association in psychology research. Here we describe a free Matlab(R) based toolbox (http://sourceforge.net/projects/robustcorrtool/) that computes robust measures of association between two or more random variables: the percentage-bend correlation and skipped-correlations. After illustrating how to use the toolbox, we show that robust methods, where outliers are down weighted or removed and accounted for in significance testing, provide better estimates of the true association with accurate false positive control and without loss of power. The different correlation methods were tested with normal data and normal data contaminated with marginal or bivariate outliers. We report estimates of effect size, false positive rate and power, and advise on which technique to use depending on the data at hand. PMID:23335907

  18. Reporting instructions significantly impact false positive rates when reading chest radiographs

    International Nuclear Information System (INIS)

    Robinson, John W.; Brennan, Patrick C.; Mello-Thoms, Claudia; Lewis, Sarah J.

    2016-01-01

    To determine the impact of specific reporting tasks on the performance of radiologists when reading chest radiographs. Ten experienced radiologists read a set of 40 postero-anterior (PA) chest radiographs: 21 nodule free and 19 with a proven solitary nodule. There were two reporting conditions: an unframed task (UFT) to report any abnormality and a framed task (FT) reporting only lung nodule/s. Jackknife free-response operating characteristic (JAFROC) figure of merit (FOM), specificity, location sensitivity and number of true positive (TP), false positive (FP), true negative (TN) and false negative (FN) decisions were used for analysis. JAFROC FOM for tasks showed a significant reduction in performance for framed tasks (P = 0.006) and an associated decrease in specificity (P = 0.011) but no alteration to the location sensitivity score. There was a significant increase in number of FP decisions made during framed versus unframed tasks for nodule-containing (P = 0.005) and nodule-free (P = 0.011) chest radiographs. No significant differences in TP were recorded. Radiologists report more FP decisions when given specific reporting instructions to search for nodules on chest radiographs. The relevance of clinical history supplied to radiologists is called into question and may induce a negative effect. (orig.)

  19. Robust correlation analyses: false positive and power validation using a new open source matlab toolbox.

    Science.gov (United States)

    Pernet, Cyril R; Wilcox, Rand; Rousselet, Guillaume A

    2012-01-01

    Pearson's correlation measures the strength of the association between two variables. The technique is, however, restricted to linear associations and is overly sensitive to outliers. Indeed, a single outlier can result in a highly inaccurate summary of the data. Yet, it remains the most commonly used measure of association in psychology research. Here we describe a free Matlab((R)) based toolbox (http://sourceforge.net/projects/robustcorrtool/) that computes robust measures of association between two or more random variables: the percentage-bend correlation and skipped-correlations. After illustrating how to use the toolbox, we show that robust methods, where outliers are down weighted or removed and accounted for in significance testing, provide better estimates of the true association with accurate false positive control and without loss of power. The different correlation methods were tested with normal data and normal data contaminated with marginal or bivariate outliers. We report estimates of effect size, false positive rate and power, and advise on which technique to use depending on the data at hand.

  20. False-positive results after environmental pinworm PCR testing due to Rhabditid nematodes in Corncob bedding.

    Science.gov (United States)

    Leblanc, Mathias; Berry, Kristina; Graciano, Sandy; Becker, Brandon; Reuter, Jon D

    2014-11-01

    Modern rodent colonies are housed in individually ventilated cages to protect the animals from contamination with adventitious pathogens. Standard health monitoring through soiled-bedding sentinels does not always detect infections, especially in the context of low pathogen prevalence. Recently proposed alternatives include analyzing environmental samples from the cages or rack exhaust by PCR to improve the detection of rodent pathogens but optimal sampling strategies have not yet been established for different microorganisms. Although generally very sensitive and specific, these molecular assays are not foolproof and subject to false-positive and -negative results and should always be interpreted cautiously with an overall understanding of the intrinsic controls and all the variables that may affect the results. Here, we report a limited Aspiculuris tetraptera outbreak in a mouse barrier facility that was detected by fecal PCR in sentinels and confirmed by fecal flotation and direct cecal examination of both sentinels and colony animals. The outbreak led to a widespread survey of all facilities for pinworms by using environmental PCR from ventilated rack exhaust plenums. Environmental PCR suggested an unexpected widespread contamination of all ventilated racks holding nonautoclaved cages, but results could not be confirmed in sentinel or colony animals by fecal flotation, cecal and colonic examination, or cage PCR testing. After additional investigation, the unexpected environmental PCR results were confirmed as false-positive findings due to the nonspecificity of the assay, leading to the amplification of rhabditid nematodes, which are not infectious in rodents but which contaminated the corncob bedding.

  1. Empirical methods for controlling false positives and estimating confidence in ChIP-Seq peaks

    Directory of Open Access Journals (Sweden)

    Courdy Samir J

    2008-12-01

    Full Text Available Abstract Background High throughput signature sequencing holds many promises, one of which is the ready identification of in vivo transcription factor binding sites, histone modifications, changes in chromatin structure and patterns of DNA methylation across entire genomes. In these experiments, chromatin immunoprecipitation is used to enrich for particular DNA sequences of interest and signature sequencing is used to map the regions to the genome (ChIP-Seq. Elucidation of these sites of DNA-protein binding/modification are proving instrumental in reconstructing networks of gene regulation and chromatin remodelling that direct development, response to cellular perturbation, and neoplastic transformation. Results Here we present a package of algorithms and software that makes use of control input data to reduce false positives and estimate confidence in ChIP-Seq peaks. Several different methods were compared using two simulated spike-in datasets. Use of control input data and a normalized difference score were found to more than double the recovery of ChIP-Seq peaks at a 5% false discovery rate (FDR. Moreover, both a binomial p-value/q-value and an empirical FDR were found to predict the true FDR within 2–3 fold and are more reliable estimators of confidence than a global Poisson p-value. These methods were then used to reanalyze Johnson et al.'s neuron-restrictive silencer factor (NRSF ChIP-Seq data without relying on extensive qPCR validated NRSF sites and the presence of NRSF binding motifs for setting thresholds. Conclusion The methods developed and tested here show considerable promise for reducing false positives and estimating confidence in ChIP-Seq data without any prior knowledge of the chIP target. They are part of a larger open source package freely available from http://useq.sourceforge.net/.

  2. False-positive ethyl glucuronide immunoassay screening caused by a propyl alcohol-based hand sanitizer.

    Science.gov (United States)

    Arndt, Torsten; Grüner, Joachim; Schröfel, Stefanie; Stemmerich, Karsten

    2012-11-30

    Urine ethyl glucuronide (EtG) is considered as a specific marker of recent ethanol consumption. We describe false-positive DRI(®) EIA EtG enzyme immunoassay results caused by propyl glucuronides in urine after using a propanol-based hand sanitizer. EtG screening was done with the DRI(®) EIA EtG assay (Microgenics), using a cut-off of 0.5 mg/L as recommended by the manufacturer and of 0.1 mg/L as demanded by the German Regulations for Reissuing Drivers Licenses. Confirmatory EtG analysis was done with the ClinMass(®) EtG LC-MS/MS testkit (Recipe), extended by the mass transitions 235.1→75.1, 235.1→85.1, and 235.1→113.1 for the detection of the 1- and 2-propyl glucuronides. Self-experiments were done by staff members of our lab (n=7), using 3 mL Sterillium(®) Classic Pure (30 g/100 g 1-propanol and 45 g/100 g 2-propanol) for hand sanitation every quarter of an hour for 8 h according to DIN EN 1500:2011-05 with and without an exhauster and by passive inhalation of the sanitizer vapor. Spot urine samples were taken immediately before and up to 24 h after the first sanitizer use. False-positive immunoassay results of up to 4 mg/L or 2.3 mg/g creatinine were obtained after normal use of the sanitizer and also after passive inhalation of the sanitizer vapor (up to 0.89 mg/L or 0.61 mg/g). Immunoassay results were positive even after 4-fold use of the sanitizer (up to 0.14 mg/L or 0.38 mg/g) and up to 6 h after the last sanitizer contact (maximum 0.63 mg/L and 0.33 mg/g for sanitizer users and 0.25 mg/g after passive inhalation). Spiking of EtG-free urine with 1-propyl glucuronide (Athena Environmental Sciences) between 0.05 and 10 mg/L clearly demonstrated a cross reaction of the immunoassay of approx. 10% as compared to EtG. LC-MS/MS of urines with a positive immunoassay EtG result did not show EtG signals, but distinct signals of 1-propyl glucuronide (n-propyl glucuronide) and 2-propyl glucuronide (iso-propyl glucuronide). An exhauster effectively prevented

  3. Using ELISPOT to expose false positive skin test conversion in tuberculosis contacts.

    Directory of Open Access Journals (Sweden)

    Philip C Hill

    2007-01-01

    Full Text Available Repeat tuberculin skin tests may be false positive due to boosting of waned immunity to past mycobacterial exposure. We evaluated whether an ELISPOT test could identify tuberculosis (TB contacts with boosting of immunity to non-tuberculous mycobacterial exposure.We conducted tuberculin and ELISPOT tests in 1665 TB contacts: 799 were tuberculin test negative and were offered a repeat test after three months. Those with tuberculin test conversion had an ELISPOT, chest X-ray and sputum analysis if appropriate. We compared converters with non-converters, assessed the probability of each of four combinations of ELISPOT results over the two time points and estimated boosting with adjustment for ELISPOT sensitivity and specificity. 704 (72% contacts had a repeat tuberculin test; 176 (25% had test conversion, which increased with exposure to a case (p = 0.002, increasing age (p = 0.0006 and BCG scar (p = 0.06. 114 tuberculin test converters had ELISPOT results: 16(14% were recruitment positive/follow-up positive, 9 (8% positive/negative, 34 (30% negative/positive, and 55 (48% were negative/negative. There was a significant non-linear effect of age for ELISPOT results in skin test converters (p = 0.038. Estimates of boosting ranged from 32%-41% of skin test converters with increasing age. Three converters were diagnosed with TB, two had ELISPOT results: both were positive, including one at recruitment.We estimate that approximately one third of tuberculin skin test conversion in Gambian TB case contacts is due to boosting of immunity to non-tuberculous mycobacterial exposure. Further longitudinal studies are required to confirm whether ELISPOT can reliably identify case contacts with tuberculin test conversion that would benefit most from prophylactic treatment.

  4. Inflammatory disorders mimicking periprosthetic joint infections may result in false positive α-defensin.

    Science.gov (United States)

    Plate, Andreas; Stadler, Laura; Sutter, Reto; Anagnostopoulos, Alexia; Frustaci, Dario; Zbinden, Reinhard; Fucentese, Sandro F; Zinkernagel, Annelies S; Zingg, Patrick O; Achermann, Yvonne

    2018-02-26

    The antimicrobial peptide α-defensin has recently been introduced as potential "single" biomarker with a high sensitivity and specificity for the preoperative diagnosis of periprosthetic joint infections (PJIs). However, most studies assessed the benefits of the test with exclusion of patients with rheumatic diseases. We aimed to evaluate the α-defensin test in a cohort study without exclusion of cases with inflammatory diseases. Between June 2016 and June 2017, we prospectively included cases with a suspected PJI and an available lateral flow test α-defensin (Synovasure®) in synovial fluid. We compared the test result to the diagnostic criteria for PJIs published by an International Consensus Group in 2013. We included 109 cases (49 hips, 60 knees) in which preoperative α-defensin tests had been performed. Thereof, 20 PJIs (16 hips, 4 knees) were diagnosed. Preoperative α-defensin tests were positive in 25 cases (22.9%) with a test sensitivity and specificity of 90% and 92.1% (95% confidence interval [CI], 68.3 - 98.8% and 84.5 - 96.8%, respectively), and a high negative predictive value of 97.6% (95% CI, 91.7 - 99.4%). We interpreted seven α-defensin tests as false positive, mainly in cases with inflammatory rheumatic diseases, including crystal deposition diseases. A negative synovial α-defensin test can reliably rule out a PJI. However, the test can be false positive in conjunction with an underlying non-infectious inflammatory disease. We therefore propose to use the α-defensin test only in addition to MSIS criteria and assessment for crystals in synovial aspirates. Copyright © 2018. Published by Elsevier Ltd.

  5. Evaluation of inadequate, indeterminate, false-negative and false-positive cases in cytological examination for breast cancer according to histological type

    Directory of Open Access Journals (Sweden)

    Yamaguchi Rin

    2012-05-01

    Full Text Available Abstract Background We previously investigated the current status of breast cytology cancer screening at seven institutes in our area of southern Fukuoka Prefecture, and found some differences in diagnostic accuracy among the institutions. In the present study, we evaluated the cases involved and noted possible reasons for their original cytological classification as inadequate, indeterminate, false-negative and false-positive according to histological type. Methods We evaluated the histological findings in 5693 individuals who underwent cytological examination for breast cancer (including inadequate, indeterminate, false-negative and false-positive cases, to determine the most common histological types and/or features in these settings and the usefulness/limitations of cytological examination for the diagnosis of breast cancer. Results Among 1152 cytologically inadequate cases, histology revealed that 75/173 (43.6% cases were benign, including mastopathy (fibrocystic disease in 38.6%, fibroadenoma in 24.0% and papilloma in 5.3%. Ninety-five of 173 (54.9% cases were histologically malignant, with scirrhous growing type, invasive ductal carcinoma (SIDC being significantly more frequent (49.5% than papillotubular growing type (Papi-tub (P P = 0.0001 and ductal carcinoma in situ (DCIS (P = 0.0001. Among 458 indeterminate cases, 54/139 (38.8% were histologically benign (mastopathy, 30.0%; fibroadenoma, 27.8%; papilloma, 26.0% and 73/139 (52.5% were malignant, with SIDC being the most frequent malignant tumor (37.0%. Among 52 false-negative cases, SIDC was significantly more frequent (42.3% than DCIS (P = 0.0049 and Papi-tub (P = 0.001. There were three false-positive cases, with one each of fibroadenoma, epidermal cyst and papilloma. Conclusions The inadequate, indeterminate, false-negative and false-positive cases showed similar histological types, notably SIDC for malignant tumors, and mastopathy, fibroadenoma and papilloma for

  6. Prime time news: the influence of primed positive and negative emotion on susceptibility to false memories.

    Science.gov (United States)

    Porter, Stephen; ten Brinke, Leanne; Riley, Sean N; Baker, Alysha

    2014-01-01

    We examined the relation between emotion and susceptibility to misinformation using a novel paradigm, the ambiguous stimuli affective priming (ASAP) paradigm. Participants (N = 88) viewed ambiguous neutral images primed either at encoding or retrieval to be interpreted as either highly positive or negative (or neutral/not primed). After viewing the images, they either were asked misleading or non-leading questions. Following a delay, memory accuracy for the original images was assessed. Results indicated that any emotional priming at encoding led to a higher susceptibility to misinformation relative to priming at recall. In particular, inducing a negative interpretation of the image at encoding led to an increased susceptibility of false memories for major misinformation (an entire object not actually present in the scene). In contrast, this pattern was reversed when priming was used at recall; a negative reinterpretation of the image decreased memory distortion relative to unprimed images. These findings suggest that, with precise experimental control, the experience of emotion at event encoding, in particular, is implicated in false memory susceptibility.

  7. Improved accuracy of cell surface shaving proteomics in Staphylococcus aureus using a false-positive control

    DEFF Research Database (Denmark)

    Solis, Nestor; Larsen, Martin Røssel; Cordwell, Stuart J

    2010-01-01

    Proteolytic treatment of intact bacterial cells is an ideal means for identifying surface-exposed peptide epitopes and has potential for the discovery of novel vaccine targets. Cell stability during such treatment, however, may become compromised and result in the release of intracellular proteins...... that complicate the final analysis. Staphylococcus aureus is a major human pathogen, causing community and hospital-acquired infections, and is a serious healthcare concern due to the increasing prevalence of multiple antibiotic resistances amongst clinical isolates. We employed a cell surface "shaving" technique...... to trypsin and three identified in the control. The use of a subtracted false-positive strategy improved enrichment of surface-exposed peptides in the trypsin data set to approximately 80% (124/155 peptides). Predominant surface proteins were those associated with methicillin resistance-surface protein SACOL...

  8. Factors associated with false-positive self-reported adherence to antihypertensive drugs.

    Science.gov (United States)

    Tedla, Y G; Bautista, L E

    2017-05-01

    Self-reported medication adherence is known to overestimate true adherence. However, little is known about patient factors that may contribute to the upward bias in self-reported medication adherence. The objective of this study is to examine whether demographic, behavioral, medication and mood factors are associated with being a false-positive self-reported adherer (FPA) to antihypertensive drug treatment. We studied 175 patients (mean age: 50 years; 57% men) from primary-care clinics starting antihypertensive drug treatment. Self-reported adherence (SRA) was measured with the Medication Adherence Report Scale (MARS) and by the number of drug doses missed in the previous week/month, and compared with pill count adherence ratio (PCAR) as gold standard. Data on adherence, demographic, behavioral, medication and mood factors were collected at baseline and every 3 months up to 1 year. FPA was defined as being a non-adherer by PCAR and an adherer by self-report. Mixed effect logistic regression was used for the analysis. Twenty percent of participants were FPA. Anxiety increased (odds ratio (OR): 3.00; P=0.01), whereas smoking (OR: 0.40; P=0.03) and drug side effects (OR: 0.46, P=0.03) decreased the probability for FPA by MARS. Education below high-school completion increased the probability of being an FPA as measured by missing doses in the last month (OR: 1.66; P=0.04) and last week (OR: 1.88; P=0.02). The validity of SRA varies significantly according to drug side effects, behavioral factors and patient's mood. Careful consideration should be given to the use of self-reported measures of adherence among patients likely to be false-positive adherers.

  9. A FALSE POSITIVE FOR OCEAN GLINT ON EXOPLANETS: THE LATITUDE-ALBEDO EFFECT

    International Nuclear Information System (INIS)

    Cowan, Nicolas B.; Abbot, Dorian S.; Voigt, Aiko

    2012-01-01

    Identifying liquid water on the surface of planets is a high priority, as this traditionally defines habitability. One proposed signature of oceans is specular reflection ('glint'), which increases the apparent albedo of a planet at crescent phases. We post-process a global climate model of an Earth-like planet to simulate reflected light curves. Significantly, we obtain glint-like phase variations even though we do not include specular reflection in our model. This false positive is the product of two generic properties: (1) for modest obliquities, a planet's poles receive less orbit-averaged stellar flux than its equator, so the poles are more likely to be covered in highly reflective snow and ice; and (2) we show that reflected light from a modest-obliquity planet at crescent phases probes higher latitudes than at gibbous phases, therefore a planet's apparent albedo will naturally increase at crescent phase. We suggest that this 'latitude-albedo effect' will operate even for large obliquities: in that case the equator receives less orbit-averaged flux than the poles, and the equator is preferentially sampled at crescent phase. Using rotational and orbital color variations to map the surfaces of directly imaged planets and estimate their obliquity will therefore be a necessary pre-condition for properly interpreting their reflected phase variations. The latitude-albedo effect is a particularly convincing glint false positive for zero-obliquity planets, and such worlds are not amenable to latitudinal mapping. This effect severely limits the utility of specular reflection for detecting oceans on exoplanets.

  10. PRE-SPECTROSCOPIC FALSE-POSITIVE ELIMINATION OF KEPLER PLANET CANDIDATES

    International Nuclear Information System (INIS)

    Batalha, Natalie M.; Rowe, Jason F.; Borucki, William J.; Koch, David G.; Lissauer, Jack J.; Gilliland, Ronald L.; Jenkins, Jon J.; Caldwell, Douglas; Dunham, Edward W.; Gautier, Thomas N.; Howell, Steve B.; Latham, David W.; Marcy, Geoff W.; Prsa, Andrej

    2010-01-01

    Ten days of commissioning data (Quarter 0) and 33 days of science data (Quarter 1) yield instrumental flux time series of ∼150,000 stars that were combed for transit events, termed threshold crossing events(TCE), each having a total detection statistic above 7.1σ. TCE light curves are modeled as star+planet systems. Those returning a companion radius smaller than 2R J are assigned a Kepler Object of Interest (KOI) number. The raw flux, pixel flux, and flux-weighted centroids of every KOI are scrutinized to assess the likelihood of being an astrophysical false positive versus the likelihood of being a planetary companion. This vetting using Kepler data is referred to as data validation (DV). Herein, we describe the DV metrics and graphics used to identify viable planet candidates amongst the KOIs. Light curve modeling tests for (1) the difference in depth of the odd- versus even-numbered transits, (2) evidence of ellipsoidal variations, and (3) evidence of a secondary eclipse event at phase = 0.5. Flux-weighted centroids are used to test for signals correlated with transit events with a magnitude and direction indicative of a background eclipsing binary. Centroid time series are complimented by analysis of images taken in-transit versus out-of-transit, the difference often revealing the pixel contributing the most to the flux change during transit. Examples are shown to illustrate each test. Candidates passing DV are submitted to ground-based observers for further false-positive elimination or confirmation/characterization.

  11. Are Hemorrhoids Associated with False-Positive Fecal Immunochemical Test Results?

    Science.gov (United States)

    Kim, Nam Hee; Park, Jung Ho; Park, Dong Il; Sohn, Chong Il; Choi, Kyuyong; Jung, Yoon Suk

    2017-01-01

    False-positive (FP) results of fecal immunochemical tests (FITs) conducted in colorectal cancer (CRC) screening could lead to performing unnecessary colonoscopies. Hemorrhoids are a possible cause of FP FIT results; however, studies on this topic are extremely rare. We investigated whether hemorrhoids are associated with FP FIT results. A retrospective study was conducted at a university hospital in Korea from June 2013 to May 2015. Of the 34547 individuals who underwent FITs, 3946 aged ≥50 years who underwent colonoscopies were analyzed. Logistic regression analysis was performed to determine factors associated with FP FIT results. Among 3946 participants, 704 (17.8%) showed positive FIT results and 1303 (33.0%) had hemorrhoids. Of the 704 participants with positive FIT results, 165 had advanced colorectal neoplasia (ACRN) and 539 had no ACRN (FP results). Of the 1303 participants with hemorrhoids, 291 showed FP results, of whom 81 showed FP results because of hemorrhoids only. Participants with hemorrhoids had a higher rate of FP results than those without hemorrhoids (291/1176, 24.7% vs. 248/2361, 10.5%; phemorrhoids as the only abnormality had a higher rate of FP results than those experiencing no such abnormalities (81/531, 15.3% vs. 38/1173, 3.2%; phemorrhoids was identified as an independent predictor of FP results (adjusted odds ratio, 2.76; 95% confidence interval, 2.24-3.40; pHemorrhoids are significantly associated with FP FIT results. Their presence seemed to be a non-negligible contributor of FP results in FIT-based CRC screening programs.

  12. Breast cancer risk is increased in the years following false-positive breast cancer screening.

    Science.gov (United States)

    Goossens, Mathijs C; De Brabander, Isabel; De Greve, Jacques; Vaes, Evelien; Van Ongeval, Chantal; Van Herck, Koen; Kellen, Eliane

    2017-09-01

    A small number of studies have investigated breast cancer (BC) risk among women with a history of false-positive recall (FPR) in BC screening, but none of them has used time-to-event analysis while at the same time quantifying the effect of false-negative diagnostic assessment (FNDA). FNDA occurs when screening detects BC, but this BC is missed on diagnostic assessment (DA). As a result of FNDA, screenings that detected cancer are incorrectly classified as FPR. Our study linked data recorded in the Flemish BC screening program (women aged 50-69 years) to data from the national cancer registry. We used Cox proportional hazards models on a retrospective cohort of 298 738 women to assess the association between FPR and subsequent BC, while adjusting for potential confounders. The mean follow-up was 6.9 years. Compared with women without recall, women with a history of FPR were at an increased risk of developing BC [hazard ratio=2.10 (95% confidence interval: 1.92-2.31)]. However, 22% of BC after FPR was due to FNDA. The hazard ratio dropped to 1.69 (95% confidence interval: 1.52-1.87) when FNDA was excluded. Women with FPR have a subsequently increased BC risk compared with women without recall. The risk is higher for women who have a FPR BI-RADS 4 or 5 compared with FPR BI-RADS 3. There is room for improvement of diagnostic assessment: 41% of the excess risk is explained by FNDA after baseline screening.

  13. Computer-Aided Detection in Digital Mammography: False-Positive Marks and Their Reproducibility in Negative Mammograms

    International Nuclear Information System (INIS)

    Kim, Seung Ja; Moon, Woo Kyung; Cho, Nariya; Chang, Jung Min; Seong, Min Hyun

    2009-01-01

    Background: There are relatively few studies reporting the frequency of false-positive computer-aided detection (CAD) marks and their reproducibility in normal cases. Purpose: To evaluate retrospectively the false-positive mark rate of a CAD system and the reproducibility of false-positive marks in two sets of negative digital mammograms. Material and Methods: Two sets of negative digital mammograms were obtained in 360 women (mean age 57 years, range 30-76 years) with an approximate interval of 1 year (mean time 343.7 days), and a CAD system was applied. False-positive CAD marks and the reproducibility were determined. Results: Of the 360 patients, 252 (70.0%) and 240 (66.7%) patients had 1-7 CAD marks on the initial and second mammograms, respectively. The false-positive CAD mark rate was 1.5 (1.1 for masses and 0.4 for calcifications) and 1.4 (1.0 for masses and 0.4 for calcifications) per examination in the initial and second mammograms, respectively. The reproducibility of the false-positive CAD marks was 12.0% for both mass (81/680) and microcalcification (33/278) marks. Conclusion: False-positive CAD marks were seen in approximately 70% of normal cases. However, the reproducibility was very low. Radiologists must be familiar with the findings of false-positive CAD marks, since they are very common and can increase the recall rate in screening

  14. Parental knowledge reduces long term anxiety induced by false-positive test results after newborn screening for cystic fibrosis

    NARCIS (Netherlands)

    Vernooij-van Langen, A.M.M.; Pal, S.M. van der; Reijntjens, A.J.T.; Loeber, J.G.; Dompeling, E.; Dankert-Roelse, J.E.

    2014-01-01

    Background: False-positive screening results in newborn screening for cystic fibrosis may lead to parental stress, family relationship problems and a changed perception of the child's health. Aim of the study: To evaluate whether parental anxiety induced by a false positive screening result

  15. Detecting and avoiding likely false-positive findings - a practical guide.

    Science.gov (United States)

    Forstmeier, Wolfgang; Wagenmakers, Eric-Jan; Parker, Timothy H

    2017-11-01

    Recently there has been a growing concern that many published research findings do not hold up in attempts to replicate them. We argue that this problem may originate from a culture of 'you can publish if you found a significant effect'. This culture creates a systematic bias against the null hypothesis which renders meta-analyses questionable and may even lead to a situation where hypotheses become difficult to falsify. In order to pinpoint the sources of error and possible solutions, we review current scientific practices with regard to their effect on the probability of drawing a false-positive conclusion. We explain why the proportion of published false-positive findings is expected to increase with (i) decreasing sample size, (ii) increasing pursuit of novelty, (iii) various forms of multiple testing and researcher flexibility, and (iv) incorrect P-values, especially due to unaccounted pseudoreplication, i.e. the non-independence of data points (clustered data). We provide examples showing how statistical pitfalls and psychological traps lead to conclusions that are biased and unreliable, and we show how these mistakes can be avoided. Ultimately, we hope to contribute to a culture of 'you can publish if your study is rigorous'. To this end, we highlight promising strategies towards making science more objective. Specifically, we enthusiastically encourage scientists to preregister their studies (including a priori hypotheses and complete analysis plans), to blind observers to treatment groups during data collection and analysis, and unconditionally to report all results. Also, we advocate reallocating some efforts away from seeking novelty and discovery and towards replicating important research findings of one's own and of others for the benefit of the scientific community as a whole. We believe these efforts will be aided by a shift in evaluation criteria away from the current system which values metrics of 'impact' almost exclusively and towards a system

  16. Evaluation of inadequate, indeterminate, false-negative and false-positive cases in cytological examination for breast cancer according to histological type

    Science.gov (United States)

    2012-01-01

    Background We previously investigated the current status of breast cytology cancer screening at seven institutes in our area of southern Fukuoka Prefecture, and found some differences in diagnostic accuracy among the institutions. In the present study, we evaluated the cases involved and noted possible reasons for their original cytological classification as inadequate, indeterminate, false-negative and false-positive according to histological type. Methods We evaluated the histological findings in 5693 individuals who underwent cytological examination for breast cancer (including inadequate, indeterminate, false-negative and false-positive cases), to determine the most common histological types and/or features in these settings and the usefulness/limitations of cytological examination for the diagnosis of breast cancer. Results Among 1152 cytologically inadequate cases, histology revealed that 75/173 (43.6%) cases were benign, including mastopathy (fibrocystic disease) in 38.6%, fibroadenoma in 24.0% and papilloma in 5.3%. Ninety-five of 173 (54.9%) cases were histologically malignant, with scirrhous growing type, invasive ductal carcinoma (SIDC) being significantly more frequent (49.5%) than papillotubular growing type (Papi-tub) (P breast disease. In particular, several inadequate, indeterminate and false-negative cases with samples collected by aspiration were diagnosed as SIDC. These findings should encourage the use of needle biopsy rather than aspiration when this histological type is identified on imaging. Namely, good communication between clinicians and pathological staff, and triple assessment (i.e., clinical, pathological and radiological assessment), are important for accurate diagnosis of aspiration samples. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7349809170055423 PMID:22607447

  17. Mammography Clinical Image Quality and the False Positive Rate in a Canadian Breast Cancer Screening Program.

    Science.gov (United States)

    Guertin, Marie-Hélène; Théberge, Isabelle; Zomahoun, Hervé Tchala Vignon; Dufresne, Michel-Pierre; Pelletier, Éric; Brisson, Jacques

    2018-05-01

    The study sought to determine if mammography quality is associated with the false positive (FP) rate in the Quebec breast cancer screening program in 2004 and 2005. Mammography quality of a random sample of screen-film mammograms was evaluated by an expert radiologist following the criteria of the Canadian Association of Radiologists. For each screening examination, scores ranging from 1 (poor quality) to 5 (excellent quality) were attributed for positioning, compression, contrast, exposure level, sharpness, and artifacts. A final overall quality score (lower or higher) was also given. Poisson regression models with robust estimation of variance and adjusted for potential confounding factors were used to assess associations of mammography quality with the FP rate. Among 1,209 women without cancer, there were 104 (8.6%) FPs. Lower overall mammography quality is associated with an increase in the FP rate (risk ratio [RR], 1.4; 95% confidence interval [CI], 1.0-2.1; P = .07) but this increase was not statistically significant. Artifacts were associated with an increase in the FP rate (RR, 2.1; 95% CI, 1.3-3.3; P = .01) whereas lower quality of exposure level was related to a reduction of the FP rate (RR, 0.4; 95% CI, 0.1-1.0; P = .01). Lower quality scores for all other quality attributes were related to a nonstatistically significant increase in the FP rate of 10%-30%. Artifacts can have a substantial effect on the FP rate. The effect of overall mammography quality on the FP rate may also be substantial and needs to be clarified. Copyright © 2017 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

  18. False positive results using calcitonin as a screening method for medullary thyroid carcinoma

    Directory of Open Access Journals (Sweden)

    Rafael Loch Batista

    2013-01-01

    Full Text Available The role of serum calcitonin as part of the evaluation of thyroid nodules has been widely discussed in literature. However there still is no consensus of measurement of calcitonin in the initial evaluation of a patient with thyroid nodule. Problems concerning cost-benefit, lab methods, false positive and low prevalence of medullary thyroid carcinoma (MTC are factors that limit this approach. We have illustrated two cases where serum calcitonin was used in the evaluation of thyroid nodule and rates proved to be high. A stimulation test was performed, using calcium as secretagogue, and calcitonin hyper-stimulation was confirmed, but anatomopathologic examination did not evidence medullar neoplasia. Anatomopathologic diagnosis detected Hashimoto thyroiditis in one case and adenomatous goiter plus an occult papillary thyroid carcinoma in the other one. Recommendation for routine use of serum calcitonin in the initial diagnostic evaluation of a thyroid nodule, followed by a confirming stimulation test if basal serum calcitonin is showed to be high, is the most currently recommended approach, but questions concerning cost-benefit and possibility of diagnosis error make the validity of this recommendation discussible.

  19. False Positive Radioiodinated Metaiodobenzylguanidine (123I-MIBG Uptake in Undifferentiated Adrenal Malignant Tumor

    Directory of Open Access Journals (Sweden)

    Hee Soo Jung

    2015-01-01

    Full Text Available 123I-Metaiodobenzylguanidine (123I-MIBG scintigraphy is a widely used functional imaging tool with a high degree of sensitivity and specificity in diagnosis of pheochromocytoma. However, rare cases of false positive reactions have been reported. A 67-year-old male patient was admitted with epigastric pain. Abdominal computed tomography (CT revealed a heterogeneous left adrenal mass 6 cm in diameter; following hormone testing, 123I-MIBG scintigraphy was performed to determine the presence of pheochromocytoma, which confirmed eccentric uptake by a large left adrenal gland mass. Chest CT and PET-CT confirmed metastatic lymphadenopathy; therefore, endobronchial ultrasound transbronchial needle aspiration was performed. Metastatic carcinoma of unknown origin was suspected from a lymph node biopsy, and surgical resection was performed for definitive diagnosis and correction of excess hormonal secretion. A final diagnosis of undifferentiated adrenal malignant tumor was rendered, instead of histologically malignant pheochromocytoma, despite the uptake of 123I-MIBG demonstrated by scintigraphy.

  20. The uterine blush. A potential false-positive in Meckel's scan interpretation

    International Nuclear Information System (INIS)

    Fink-Bennett, D.

    1982-01-01

    To determine the presence, prevalence, and clinical importance of /sup 99m/Tc pertechnetate uterine uptake, this retrospective analysis of 71 Meckel's scans was undertaken. Specifically, each study was evaluated for the presence of a focal accumulation of radiotracer cephalad to the bladder. Patients received an intravenous dose of 150 microCi/kg of /sup 99m/Tc pertechnetate. Each study consisted of 15 one minute anterior serial gamma camera images, and a 15, 30, and 60 minute anterior, right lateral and posterior scintiscan. Menstrual histories were obtained from all patients except two. No males (33/33), nor premenstrual (13/13), menopausal (4/4) or posthysterectomy (2/2) patients revealed a uterine blush. Eleven of 15 patients (73%) with regular menses demonstrated a uterine blush. They were in the menstrual or secretory phases of their cycle. Four demonstrated no uterine uptake, had regular periods, but were in the proliferative phase of their cycle. Two with irregular periods, and one with no recorded menstrual history, manifested the blush. Radiotracer should be expected in the uterus during the menstrual and secretory phases of the menstrual cycle. It is a manifestation of a normal physiologic phenomenon, and must be recognized to prevent false-positive Meckel's scan interpretations

  1. False positive localisation of C-11 methionine in a colloid nodule

    International Nuclear Information System (INIS)

    Mahajan, Sonia; Tripathi, Madhavi; Jaimini, Abhinav; Dinesh, Anant

    2011-01-01

    A 45-year-old female diagnosed with carcinoma of the left breast on histopathological examination underwent both 18 F-flourodeoxyglucose (FDG) and 11C-methionine (MET) positron emission tomography/computed tomography (PET/CT) as part of a protocol comparing the utility of these tracers for predicting a response to neoadjuvant chemotherapy in breast carcinoma. Abnormal FDG and MET accumulation was noted in the left breast primary, left axillary lymph nodes, and also in a well-defined nodule present in the left lobe of the thyroid gland. Keeping in mind the possibility of thyroid neoplasm/metastasis, the patient was referred for fine needle aspiration cytology (FNAC) from the thyroid nodule that revealed features of a simple colloid nodule. Focal thyroid lesions incidentally found on 18 F-FDG PET/CT have a high risk of thyroid malignancy. Non-specific accumulation of FDG in thyroid adenomas is also known. This case highlights a potential cause for false positive on C-11 MET PET/CT in colloid adenomas, which should be kept in mind while using this tracer for oncological indications

  2. THE POSSIBLE MOON OF KEPLER-90g IS A FALSE POSITIVE

    Energy Technology Data Exchange (ETDEWEB)

    Kipping, D. M.; Torres, G.; Buchhave, L. A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Huang, X.; Bakos, G. Á. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 05844 (United States); Nesvorný, D. [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Schmitt, A. R., E-mail: dkipping@cfa.harvard.edu

    2015-01-20

    The discovery of an exomoon would provide deep insights into planet formation and the habitability of planetary systems, with transiting examples being particularly sought after. Of the hundreds of Kepler planets now discovered, the seven-planet system Kepler-90 is unusual for exhibiting an unidentified transit-like signal in close proximity to one of the transits of the long-period gas-giant Kepler-90g, as noted by Cabrera et al. As part of the ''Hunt for Exomoons with Kepler'' project, we investigate this possible exomoon signal and find it passes all conventional photometric, dynamical, and centroid diagnostic tests. However, pixel-level light curves indicate that the moon-like signal occurs on nearly all of the target's pixels, which we confirm using a novel way of examining pixel-level data which we dub the ''transit centroid''. This test reveals that the possible exomoon to Kepler-90g is likely a false positive, perhaps due to a cosmic ray induced sudden pixel sensitivity dropout. This work highlights the extreme care required for seeking non-periodic low-amplitude transit signals, such as exomoons.

  3. The uterine blush. A potential false-positive in Meckel's scan interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Fink-Bennett, D.

    1982-10-01

    To determine the presence, prevalence, and clinical importance of /sup 99m/Tc pertechnetate uterine uptake, this retrospective analysis of 71 Meckel's scans was undertaken. Specifically, each study was evaluated for the presence of a focal accumulation of radiotracer cephalad to the bladder. Patients received an intravenous dose of 150 microCi/kg of /sup 99m/Tc pertechnetate. Each study consisted of 15 one minute anterior serial gamma camera images, and a 15, 30, and 60 minute anterior, right lateral and posterior scintiscan. Menstrual histories were obtained from all patients except two. No males (33/33), nor premenstrual (13/13), menopausal (4/4) or posthysterectomy (2/2) patients revealed a uterine blush. Eleven of 15 patients (73%) with regular menses demonstrated a uterine blush. They were in the menstrual or secretory phases of their cycle. Four demonstrated no uterine uptake, had regular periods, but were in the proliferative phase of their cycle. Two with irregular periods, and one with no recorded menstrual history, manifested the blush. Radiotracer should be expected in the uterus during the menstrual and secretory phases of the menstrual cycle. It is a manifestation of a normal physiologic phenomenon, and must be recognized to prevent false-positive Meckel's scan interpretations.

  4. Benign oral pathology as a cause of false positive 131I uptake in thyroid carcinoma

    International Nuclear Information System (INIS)

    Mansberg, R.; Wadhwa, S.S.; Fernandes, V.B.

    1997-01-01

    Full text: We present three thyroidectomised patients with a history of thyroid carcinoma who had non-metastatic 131 I uptake due to benign oral pathology. A salivary gland study suggested impaired function but no obstruction was demonstrated on a sialogram. The symptoms resolved on antibiotic therapy and a subsequent 131 I study was normal. A subsequent thallium study demonstrated physiological tracer distribution. A 35-year-old female with papillary cell carcinoma of the thyroid demonstrated a focus of uptake on the right hemi-mandible following both a diagnostic and a therapeutic dose of 131 I. This area was tender and an OPG confirmed an area of liquefaction at this site. A 53-year-old female with medullary cell carcinoma of the thyroid demonstrated a focus of uptake in the right side of the maxilla following a diagnostic administration of 131 I. An OPG confirmed an area of liquefaction around the apex of the right upper centre. These three cases illustrate salivary gland and dental inflammation as causes of false positive 131 I uptake. It is important to differentiate non-metastatic 131 I uptake from that due to functioning metastatic thyroid carcinoma in order to avoid inappropriate treatment with large additional doses of 131 I. As in these patients, clinical assessment and the use of anatomical imaging or other isotopes such as thallium or technetium can be helpful in ruling out a mistaken diagnosis of metastasis

  5. Limited agreement of independent RNAi screens for virus-required host genes owes more to false-negative than false-positive factors.

    Directory of Open Access Journals (Sweden)

    Linhui Hao

    Full Text Available Systematic, genome-wide RNA interference (RNAi analysis is a powerful approach to identify gene functions that support or modulate selected biological processes. An emerging challenge shared with some other genome-wide approaches is that independent RNAi studies often show limited agreement in their lists of implicated genes. To better understand this, we analyzed four genome-wide RNAi studies that identified host genes involved in influenza virus replication. These studies collectively identified and validated the roles of 614 cell genes, but pair-wise overlap among the four gene lists was only 3% to 15% (average 6.7%. However, a number of functional categories were overrepresented in multiple studies. The pair-wise overlap of these enriched-category lists was high, ∼19%, implying more agreement among studies than apparent at the gene level. Probing this further, we found that the gene lists implicated by independent studies were highly connected in interacting networks by independent functional measures such as protein-protein interactions, at rates significantly higher than predicted by chance. We also developed a general, model-based approach to gauge the effects of false-positive and false-negative factors and to estimate, from a limited number of studies, the total number of genes involved in a process. For influenza virus replication, this novel statistical approach estimates the total number of cell genes involved to be ∼2,800. This and multiple other aspects of our experimental and computational results imply that, when following good quality control practices, the low overlap between studies is primarily due to false negatives rather than false-positive gene identifications. These results and methods have implications for and applications to multiple forms of genome-wide analysis.

  6. Effect of radiologist experience on the risk of false-positive results in breast cancer screening programs

    International Nuclear Information System (INIS)

    Zubizarreta Alberdi, Raquel; Llanes, Ana B.F.; Ortega, Raquel Almazan; Exposito, Ruben Roman; Collado, Jose M.V.; Oliveres, Xavier Castells; Queiro Verdes, Teresa; Natal Ramos, Carmen; Sanz, Maria Ederra; Salas Trejo, Dolores

    2011-01-01

    To evaluate the effect of radiologist experience on the risk of false-positive results in population-based breast cancer screening programmes. We evaluated 1,440,384 single-read screening mammograms, corresponding to 471,112 women aged 45-69 years participating in four Spanish programmes between 1990 and 2006. The mammograms were interpreted by 72 radiologists. The overall percentage of false-positive results was 5.85% and that for false-positives resulting in an invasive procedure was 0.38%. Both the risk of false-positives overall and of false-positives leading to an invasive procedure significantly decreased (p 14,999 mammograms with respect to the reference category (<500). The risk of both categories of false-positives was also significantly reduced (p < 0.001) as radiologists' years of experience increased: OR 0.96 and OR 0.84, respectively, for 1 year's experience and OR 0.72 and OR 0.73, respectively, for more than 4 years' experience with regard to the category of <1 year's experience. Radiologist experience is a determining factor in the risk of a false-positive result in breast cancer screening. (orig.)

  7. Mouse obesity network reconstruction with a variational Bayes algorithm to employ aggressive false positive control

    Directory of Open Access Journals (Sweden)

    Logsdon Benjamin A

    2012-04-01

    Full Text Available Abstract Background We propose a novel variational Bayes network reconstruction algorithm to extract the most relevant disease factors from high-throughput genomic data-sets. Our algorithm is the only scalable method for regularized network recovery that employs Bayesian model averaging and that can internally estimate an appropriate level of sparsity to ensure few false positives enter the model without the need for cross-validation or a model selection criterion. We use our algorithm to characterize the effect of genetic markers and liver gene expression traits on mouse obesity related phenotypes, including weight, cholesterol, glucose, and free fatty acid levels, in an experiment previously used for discovery and validation of network connections: an F2 intercross between the C57BL/6 J and C3H/HeJ mouse strains, where apolipoprotein E is null on the background. Results We identified eleven genes, Gch1, Zfp69, Dlgap1, Gna14, Yy1, Gabarapl1, Folr2, Fdft1, Cnr2, Slc24a3, and Ccl19, and a quantitative trait locus directly connected to weight, glucose, cholesterol, or free fatty acid levels in our network. None of these genes were identified by other network analyses of this mouse intercross data-set, but all have been previously associated with obesity or related pathologies in independent studies. In addition, through both simulations and data analysis we demonstrate that our algorithm achieves superior performance in terms of power and type I error control than other network recovery algorithms that use the lasso and have bounds on type I error control. Conclusions Our final network contains 118 previously associated and novel genes affecting weight, cholesterol, glucose, and free fatty acid levels that are excellent obesity risk candidates.

  8. ST-Segment Depression in Hyperventilation Indicates a False Positive Exercise Test in Patients with Mitral Valve Prolapse

    Directory of Open Access Journals (Sweden)

    Andreas P. Michaelides

    2010-01-01

    Full Text Available Objectives. Mitral valve prolapse (MVP is a known cause for false positive exercise test (ET. The purpose of this study was to establish additional electrocardiographic criteria to distinguish the false positive exercise results in patients with MVP. Methods. We studied 218 consecutive patients ( years, 103 males with MVP (according to echocardiographic study, and positive treadmill ET was performed due to multiple cardiovascular risk factors or angina-like symptoms. A coronary angiography was performed to detect coronary artery disease (CAD. Results. From 218 patients, 90 (group A presented with normal coronary arteries according to the angiography (false positive ET while the rest 128 (group B presented with CAD. ST-segment depression in hyperventilation phase was present in 54 patients of group A (60% while only in 14 patients of group B (11%, . Conclusions. Presence of ST-segment depression in hyperventilation phase favors a false positive ET in patients with MVP.

  9. On minimizing assignment errors and the trade-off between false positives and negatives in parentage analysis

    KAUST Repository

    Harrison, Hugo B.

    2013-11-04

    Genetic parentage analyses provide a practical means with which to identify parent-offspring relationships in the wild. In Harrison et al.\\'s study (2013a), we compare three methods of parentage analysis and showed that the number and diversity of microsatellite loci were the most important factors defining the accuracy of assignments. Our simulations revealed that an exclusion-Bayes theorem method was more susceptible to false-positive and false-negative assignments than other methods tested. Here, we analyse and discuss the trade-off between type I and type II errors in parentage analyses. We show that controlling for false-positive assignments, without reporting type II errors, can be misleading. Our findings illustrate the need to estimate and report both the rate of false-positive and false-negative assignments in parentage analyses. © 2013 John Wiley & Sons Ltd.

  10. On minimizing assignment errors and the trade-off between false positives and negatives in parentage analysis

    KAUST Repository

    Harrison, Hugo B.; Saenz Agudelo, Pablo; Planes, Serge; Jones, Geoffrey P.; Berumen, Michael L.

    2013-01-01

    Genetic parentage analyses provide a practical means with which to identify parent-offspring relationships in the wild. In Harrison et al.'s study (2013a), we compare three methods of parentage analysis and showed that the number and diversity of microsatellite loci were the most important factors defining the accuracy of assignments. Our simulations revealed that an exclusion-Bayes theorem method was more susceptible to false-positive and false-negative assignments than other methods tested. Here, we analyse and discuss the trade-off between type I and type II errors in parentage analyses. We show that controlling for false-positive assignments, without reporting type II errors, can be misleading. Our findings illustrate the need to estimate and report both the rate of false-positive and false-negative assignments in parentage analyses. © 2013 John Wiley & Sons Ltd.

  11. Classification of radiological errors in chest radiographs, using support vector machine on the spatial frequency features of false- negative and false-positive regions

    Science.gov (United States)

    Pietrzyk, Mariusz W.; Donovan, Tim; Brennan, Patrick C.; Dix, Alan; Manning, David J.

    2011-03-01

    Aim: To optimize automated classification of radiological errors during lung nodule detection from chest radiographs (CxR) using a support vector machine (SVM) run on the spatial frequency features extracted from the local background of selected regions. Background: The majority of the unreported pulmonary nodules are visually detected but not recognized; shown by the prolonged dwell time values at false-negative regions. Similarly, overestimated nodule locations are capturing substantial amounts of foveal attention. Spatial frequency properties of selected local backgrounds are correlated with human observer responses either in terms of accuracy in indicating abnormality position or in the precision of visual sampling the medical images. Methods: Seven radiologists participated in the eye tracking experiments conducted under conditions of pulmonary nodule detection from a set of 20 postero-anterior CxR. The most dwelled locations have been identified and subjected to spatial frequency (SF) analysis. The image-based features of selected ROI were extracted with un-decimated Wavelet Packet Transform. An analysis of variance was run to select SF features and a SVM schema was implemented to classify False-Negative and False-Positive from all ROI. Results: A relative high overall accuracy was obtained for each individually developed Wavelet-SVM algorithm, with over 90% average correct ratio for errors recognition from all prolonged dwell locations. Conclusion: The preliminary results show that combined eye-tracking and image-based features can be used for automated detection of radiological error with SVM. The work is still in progress and not all analytical procedures have been completed, which might have an effect on the specificity of the algorithm.

  12. The illusion of the positive: the impact of natural and induced mood on older adults' false recall.

    Science.gov (United States)

    Emery, Lisa; Hess, Thomas M; Elliot, Tonya

    2012-11-01

    Recent research suggests that affective and motivational processes can influence age differences in memory. In the current study, we examine the impact of both natural and induced mood state on age differences in false recall. Older and younger adults performed a version of the Deese-Roediger-McDermott (DRM; Roediger & McDermott, 1995 , Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803) false memory paradigm in either their natural mood state or after a positive or negative mood induction. Results indicated that, after accounting for age differences in basic cognitive function, age-related differences in positive mood during the testing session were related to increased false recall in older adults. Inducing older adults into a positive mood also exacerbated age differences in false memory. In contrast, veridical recall did not appear to be systematically influenced by mood. Together, these results suggest that positive mood states can impact older adults' information processing and potentially increase underlying cognitive age differences.

  13. Early Disseminated Lyme Disease Causing False-Positive Serology for Primary Epstein-Barr Virus Infection: Report of 2 Cases.

    Science.gov (United States)

    Pavletic, Adriana J; Marques, Adriana R

    2017-07-15

    False-positive serology for Lyme disease was reported in patients with acute infectious mononucleosis. Here we describe 2 patients with early disseminated Lyme disease who were misdiagnosed with infectious mononucleosis based on false-positive tests for primary Epstein-Barr virus infection. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  14. Data from Paper “False-Positive Psychology: Undisclosed Flexibility in Data Collection and Analysis Allows Presenting Anything as Significant”

    Directory of Open Access Journals (Sweden)

    Joseph P Simmons

    2014-02-01

    Full Text Available The data includes measures collected for the two experiments reported in “False-Positive Psychology” [1] where listening to a randomly assigned song made people feel younger (Study 1 or actually be younger (Study 2. These data are useful because they illustrate inflations of false positive rates due to flexibility in data collection, analysis, and reporting of results. Data are useful for educational purposes.

  15. Association between immunoglobulin GM and KM genotypes and placental malaria in HIV-1 negative and positive women in western Kenya.

    Directory of Open Access Journals (Sweden)

    Nnaemeka C Iriemenam

    Full Text Available Immunoglobulin (Ig GM and KM allotypes, genetic markers of γ and κ chains, are associated with humoral immune responsiveness. Previous studies have shown the relationships between GM6-carrying haplotypes and susceptibility to malaria infection in children and adults; however, the role of the genetic markers in placental malaria (PM infection and PM with HIV co-infection during pregnancy has not been investigated. We examined the relationship between the gene polymorphisms of Ig GM6 and KM allotypes and the risk of PM infection in pregnant women with known HIV status. DNA samples from 728 pregnant women were genotyped for GM6 and KM alleles using polymerase chain reaction-restriction fragment length polymorphism method. Individual GM6 and KM genotypes and the combined GM6 and KM genotypes were assessed in relation to PM in HIV-1 negative and positive women, respectively. There was no significant effect of individual GM6 and KM genotypes on the risk of PM infection in HIV-1 negative and positive women. However, the combination of homozygosity for GM6(+ and KM3 was associated with decreased risk of PM (adjusted OR, 0.25; 95% CI, 0.08-0.8; P = 0.019 in HIV-1 negative women while in HIV-1 positive women the combination of GM6(+/- with either KM1-3 or KM1 was associated with increased risk of PM infection (adjusted OR, 2.10; 95% CI, 1.18-3.73; P = 0.011. Hardy-Weinberg Equilibrium (HWE tests further showed an overall significant positive F(is (indication of deficit in heterozygotes for GM6 while there was no deviation for KM genotype frequency from HWE in the same population. These findings suggest that the combination of homozygous GM6(+ and KM3 may protect against PM in HIV-1 negative women while the HIV-1 positive women with heterozygous GM6(+/- combined with KM1-3 or KM1 may be more susceptible to PM infection. The deficit in heterozygotes for GM6 further suggests that GM6 could be under selection likely by malaria infection.

  16. Consensus-based identification of factors related to false-positives in ultrasound scanning of synovitis and tenosynovitis.

    Science.gov (United States)

    Ikeda, Kei; Narita, Akihiro; Ogasawara, Michihiro; Ohno, Shigeru; Kawahito, Yutaka; Kawakami, Atsushi; Ito, Hiromu; Matsushita, Isao; Suzuki, Takeshi; Misaki, Kenta; Ogura, Takehisa; Kamishima, Tamotsu; Seto, Yohei; Nakahara, Ryuichi; Kaneko, Atsushi; Nakamura, Takayuki; Henmi, Mihoko; Fukae, Jun; Nishida, Keiichiro; Sumida, Takayuki; Koike, Takao

    2016-01-01

    We aimed to identify causes of false-positives in ultrasound scanning of synovial/tenosynovial/bursal inflammation and provide corresponding imaging examples. We first performed systematic literature review to identify previously reported causes of false-positives. We next determined causes of false-positives and corresponding example images for educational material through Delphi exercises and discussion by 15 experts who were an instructor and/or a lecturer in the 2013 advanced course for musculoskeletal ultrasound organized by Japan College of Rheumatology Committee for the Standardization of Musculoskeletal Ultrasonography. Systematic literature review identified 11 articles relevant to sonographic false-positives of synovial/tenosynovial inflammation. Based on these studies, 21 candidate causes of false-positives were identified in the consensus meeting. Of these items, 11 achieved a predefined consensus (≥ 80%) in Delphi exercise and were classified as follows: (I) Gray-scale assessment [(A) non-specific synovial findings and (B) normal anatomical structures which can mimic synovial lesions due to either their low echogenicity or anisotropy]; (II) Doppler assessment [(A) Intra-articular normal vessels and (B) reverberation)]. Twenty-four corresponding examples with 49 still and 23 video images also achieved consensus. Our study provides a set of representative images that can help sonographers to understand false-positives in ultrasound scanning of synovitis and tenosynovitis.

  17. Commercial radioimmunoassay for beta subunit of human chorionic gonadotropin: falsely positive determinations due to elevated serum luteinizing hormone

    International Nuclear Information System (INIS)

    Fowler, J.E. Jr.; Platoff, G.E.; Kubrock, C.A.; Stuzman, R.E.

    1982-01-01

    Among 17 men who had received seemingly curative treatment for unilateral non-seminomatous germ cell tumors for the testis and who had consistently normal serum human chorionic gonadotropin (HCG) levels at a reference laboratory, 7 (41%) had at least one falsely positive commercial serum HCG determination. To investigate the cause of these falsely positive determinations the authors measured the cross reactivity of luteinizing hormone (LH) and follicle stimulating hormone (FSH) standards in the commercial HCG assay, and studied the relationships between commercial HCG levels and serum LH levels, serum FSH levels and gonadal status in men with and without normal gonadal function. The falsely positive HCG determinations appeared to be due to elevated serum LH levels and cross reactivity of LH in the commercial HCG assay because: 1) there was substantial cross reactivity of the LH standards in the commercial assay, 2) the serum LH was elevated in four of six men with solitary testes, 3) there was a striking correlation between elevated serum LH levels and falsely elevated commercial HCG levels in ten men with solitary or absent testes, and 4) there were no falsely positive HCG determinations in 13 normal men but there were falsely positive HCG determinations in seven of ten anorchid men

  18. Interference Helps to Equalize the Read Range and Reduce False Positives of Passive RFID Tags

    DEFF Research Database (Denmark)

    Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund

    2012-01-01

    In various applications of RFID systems a reader should reliably get the ID of the tags that are within a bounded proximity region, termed the interrogation zone. This gives rise to two types of errors 1) False Negative Detections (FNDs), when tags within the intended interrogation zone cannot...... interference enables design of well-defined interrogation zones for passive RFID systems....

  19. The effect of information about false negative and false positive rates on people's attitudes towards colorectal cancer screening using faecal occult blood testing (FOBt).

    Science.gov (United States)

    Miles, Anne; Rodrigues, Vania; Sevdalis, Nick

    2013-11-01

    To examine the impact of numeric risk information about false negative (FN) and false positive (FP) rates in faecal occult blood testing (FOBt) on attitudes towards screening. 95 people aged 45-59, living in England, read 6 hypothetical vignettes presented online about the use of FOB testing to detect bowel cancer, in which information about FN and FP rates was systematically varied. Both verbal and numeric FN risk information reduced people's interest in screening compared with no FN information. Numeric FN risk information reduced people's perceptions of screening effectiveness and lowered perceived trust in the results of screening compared with both verbal FN information and no FN information. FP information did not affect attitudes towards FOB testing. There was limited evidence that FN information reduced interest and perceptions of screening effectiveness more in educated groups. Numeric FN risk information decreased people's perceptions of screening effectiveness and trust in the results of screening but did not affect people's interest in screening anymore than verbal FN risk information. Numeric FN information could be added to patient information without affecting interest in screening, although this needs to be replicated in a larger, more representative sample. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. Effect of radiologist experience on the risk of false-positive results in breast cancer screening programs

    Energy Technology Data Exchange (ETDEWEB)

    Zubizarreta Alberdi, Raquel [Galician Breast Cancer Screening Programme, Public Health and Planning Directorate, Health Office, Galicia (Spain); Edificio Administrativo da Conselleria de Sanidade, Servicio de Programas Poboacionais de Cribado, Direccion Xeral de Saude Publica e Planificacion, Santiago de Compostela, Galicia (Spain); Llanes, Ana B.F.; Ortega, Raquel Almazan [Galician Breast Cancer Screening Programme, Public Health and Planning Directorate, Health Office, Galicia (Spain); Exposito, Ruben Roman; Collado, Jose M.V.; Oliveres, Xavier Castells [Department of Epidemiology and Evaluation, Institut Municipal d' Investigacio Medica-Parc de Salut Mar. CIBERESP, Barcelona (Spain); Queiro Verdes, Teresa [Galician Agency for Health Technology Assessment, Public Health and Planning Directorate, Health Office, Galicia (Spain); Natal Ramos, Carmen [Principality of Asturias Breast Cancer Screening Programme, Principality of Asturias (Spain); Sanz, Maria Ederra [Public Health Institute, Navarra Breast Cancer Screening Programme, Pamplona (Spain); Salas Trejo, Dolores [General Directorate Public Health and Centre for Public Health Research (CSISP), Valencia Breast Cancer Screening Programme, Valencia (Spain)

    2011-10-15

    To evaluate the effect of radiologist experience on the risk of false-positive results in population-based breast cancer screening programmes. We evaluated 1,440,384 single-read screening mammograms, corresponding to 471,112 women aged 45-69 years participating in four Spanish programmes between 1990 and 2006. The mammograms were interpreted by 72 radiologists. The overall percentage of false-positive results was 5.85% and that for false-positives resulting in an invasive procedure was 0.38%. Both the risk of false-positives overall and of false-positives leading to an invasive procedure significantly decreased (p < 0.001) with greater reading volume in the previous year: OR 0.77 and OR 0.78, respectively, for a reading volume 500-1,999 mammograms and OR 0.59 and OR 0.60 for a reading volume of >14,999 mammograms with respect to the reference category (<500). The risk of both categories of false-positives was also significantly reduced (p < 0.001) as radiologists' years of experience increased: OR 0.96 and OR 0.84, respectively, for 1 year's experience and OR 0.72 and OR 0.73, respectively, for more than 4 years' experience with regard to the category of <1 year's experience. Radiologist experience is a determining factor in the risk of a false-positive result in breast cancer screening. (orig.)

  1. False-positive findings in Cochrane meta-analyses with and without application of trial sequential analysis

    DEFF Research Database (Denmark)

    Imberger, Georgina; Thorlund, Kristian; Gluud, Christian

    2016-01-01

    outcome, a negative result and sufficient power. We defined a negative result as one where the 95% CI for the effect included 1.00, a positive result as one where the 95% CI did not include 1.00, and sufficient power as the required information size for 80% power, 5% type 1 error, relative risk reduction...... of 10% or number needed to treat of 100, and control event proportion and heterogeneity taken from the included studies. We re-conducted the meta-analyses, using conventional cumulative techniques, to measure how many false positives would have occurred if these meta-analyses had been updated after each...... new trial. For each false positive, we performed TSA, using three different approaches. RESULTS: We screened 4736 systematic reviews to find 100 meta-analyses that fulfilled our inclusion criteria. Using conventional cumulative meta-analysis, false positives were present in seven of the meta...

  2. [False positive serum des-gamma-carboxy prothrombin after resection of hepatocellular carcinoma].

    Science.gov (United States)

    Hiramatsu, Kumiko; Tanaka, Yasuhito; Takagi, Kazumi; Iida, Takayasu; Takasaka, Yoshimitsu; Mizokami, Masashi

    2007-04-01

    Measurements of serum concentrations of des-gamma-carboxy-prothrombin (PIVKA-II) are widely used for diagnosing hepatocellular carcinoma (HCC). Recently, when we evaluated the correlation of PIVKA-II between two commercially available PIVKA-II immunoassay kits (Lumipulse f vs. Picolumi) to introduce it in our hospital, false high values of PIVKA-II were observed in Lumipulse assay. Four(4%) of 100 serum samples showed false high values, and all of them were obtained from patients less than 2 month after curative resection of HCC. Examining additional 7 patients with HCC resection, serum samples from the 5 patients had the same trend. To elucidate the non-specific reaction by Lumipulse assay which utilized alkaline phosphatase (ALP) enzymatic reaction, inhibition assays by various absorbents such as inactive ALP and IgM antibodies were performed. Excess of inactive ALP reduced the high values of PIVKA-II. Note that anti-bleeding sheets (fibrinogen combined drug), which included bovine thrombin, were directly attached on liver of all patients with HCC resection in this study. As the sheets also contaminate ALP and probably produce IgM antibodies to ALP, the IgM may cross-react with anti-PIVKA-II antibodies directly. Taken together, it was suggested that produced antibodies against ALP derived from anti-bleeding sheets led false high values of PIVKA-II in the patients with HCC resection.

  3. Prospective assessment of the false positive rate of the Australian snake venom detection kit in healthy human samples.

    Science.gov (United States)

    Nimorakiotakis, Vasilios Bill; Winkel, Kenneth D

    2016-03-01

    The Snake Venom Detection Kit (SVDK; bioCSL Pty Ltd, Australia) distinguishes venom from the five most medically significant snake immunotypes found in Australia. This study assesses the rate of false positives that, by definition, refers to a positive assay finding in a sample from someone who has not been bitten by a venomous snake. Control unbroken skin swabs, simulated bite swabs and urine specimens were collected from 61 healthy adult volunteers [33 males and 28 females] for assessment. In all controls, simulated bite site and urine samples [a total of 183 tests], the positive control well reacted strongly within one minute and no test wells reacted during the ten minute incubation period. However, in two urine tests, the negative control well gave a positive reaction (indicating an uninterpretable test). A 95% confidence interval for the false positive rate, on a per-patient rate, derived from the findings of this study, would extend from 0% to 6% and, on a per-test basis, it would be 0-2%. It appears to be a very low incidence (0-6%) of intrinsic true false positives for the SVDK. The clinical impresssion of a high SVDK false positive rate may be mostly related to operator error. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  4. Enhanced opsonisation of Rhesus D-positive human red blood cells by recombinant polymeric immunoglobulin G anti-G antibodies.

    Science.gov (United States)

    Díaz-Solano, Dylana; Fuenmayor, Jaheli; Montaño, Ramon F

    2018-02-01

    Anti-RhD antibodies (anti-D) are important in the prophylaxis of haemolytic disease of the foetus and newborn (HDFN) due to RhD incompatibility. Current preparations of anti-D are sourced from hyperimmune human plasma, so its production carries a risk of disease and is dependent on donor availability. Despite the efforts to develop a monoclonal preparation with similar prophylactic properties to the plasma-derived anti-D, no such antibody is yet available. Here we studied the agglutinating, opsonic and haemolytic activities of two recombinant polymeric immunoglobulins (Ig) against the G antigen of the Rh complex. Recombinant polymeric anti-G IgG1 (IgG1μtp) and IgG3 (IgG3μtp) were produced in vitro, purified by protein G-affinity chromatography, and analysed by gel electrophoresis. Their agglutinating, opsonic and haemolytic activities were evaluated using haemagglutination, erythrophagocytosis, and complement activation assays. The recombinant IgG1μtp and IgG3μtp anti-G antibodies ranged from 150,000 to 1,000,000 Da in molecular weight, indicating the formation of polymeric IgG. No complement activation or haemolytic activity was detected upon incubation of RhD-positive red-blood cells with the polymeric anti-G IgG. Both polymers were better opsonins than a prophylactic preparation of plasma-derived anti-D. The enhanced opsonic properties of the polymeric anti-G IgG1μtp and IgG3μtp could allow them to mediate the clearance of RhD-positive red blood cells from circulation more efficiently than natural or other synthetic prophylactic anti-D options. Their inability to induce complement-mediated haemolysis would be prophylactically convenient and is comparable in vitro to that of the available plasma-derived polyclonal anti-D preparations. The described properties suggest that polymeric antibodies like these (but with anti-D specificity) may be testable candidates for prophylaxis of HDFN caused by anti-D.

  5. False-positive findings in mammography screening induces short-term distress - breast cancer-specific concern prevails longer

    DEFF Research Database (Denmark)

    Aro, A R; Pilvikki Absetz, S; van Elderen, T M

    2000-01-01

    -ups at 2 and 12 months postscreening. At 2 months, there was a moderate multivariate effect of group on distress; and intrusive thinking and worry about breast cancer, in particular, were most frequent amongst the false positives. Intrusive thinking still prevailed at 12 months, in addition to a higher...... findings (n=1407), false-positive findings (n=492) and referents from outside the screening programme (n=1718, age 48-49 years). Distress was measured as illness worry, anxiety, depression, cancer beliefs and early detection behaviour. Measurements were one month before screening invitation with follow...... perceived breast cancer risk and susceptibility. Distress related to screening and false-positive findings seems to be moderate, but prevailing cancer-specific concerns call for improvements in screening programmes....

  6. A false-positive detection bias as a function of state and trait schizotypy in interaction with intelligence

    Directory of Open Access Journals (Sweden)

    Phillip eGrant

    2014-09-01

    Full Text Available Hallucinatory experiences are by far not limited to patients with clinical psychosis. A number of internal and external factors may bring about such experiences in healthy individuals, whereby the personality trait of (positive schizotypy is a major mediator of individual differences. Psychotic experiences are defined as associating abnormal meaning to real but objectively irrelevant perceptions. Especially the ambiguity of a stimulus correlates positively with the likelihood of abnormal interpretation, and intelligence is believed to have an important influence and act as protective against clinical psychosis in highly schizotypic individuals.In this study we presented 131 healthy participants with 216 15-letter strings containing either a word, a non-word or only random letters and asked them to report, whether or not they believed to have seen a word. The aim was to replicate findings that participants with high values in positive schizotypy on the trait-level make more false-positive errors and assess the role of stimulus-ambiguity and verbal intelligence. Additionally, we wanted to examine whether the same effect could be shown for indices of state schizotypy.Our results support findings that both state and trait positive schizotypy explain significant variance in seeing things that are not there and that the properties of individual stimuli have additional strong effects on the false-positive hit rates. Finally, we found that verbal intelligence and positive schizotypy interact with stimulus-ambiguity in the production of false-positive perceptions.

  7. A false-positive detection bias as a function of state and trait schizotypy in interaction with intelligence.

    Science.gov (United States)

    Grant, Phillip; Balser, Mona; Munk, Aisha Judith Leila; Linder, Jens; Hennig, Juergen

    2014-01-01

    Hallucinatory experiences are by far not limited to patients with clinical psychosis. A number of internal and external factors may bring about such experiences in healthy individuals, whereby the personality trait of (positive) schizotypy is a major mediator of individual differences. Psychotic experiences are defined as associating abnormal meaning to real but objectively irrelevant perceptions. Especially, the ambiguity of a stimulus correlates positively with the likelihood of abnormal interpretation, and intelligence is believed to have an important influence and act as protective against clinical psychosis in highly schizotypic individuals. In this study, we presented 131 healthy participants with 216 15-letter strings containing either a word, a non-word, or only random letters and asked them to report, whether or not they believed to have seen a word. The aim was to replicate findings that participants with high values in positive schizotypy on the trait-level make more false-positive errors and assess the role of stimulus-ambiguity and verbal intelligence. Additionally, we wanted to examine whether the same effect could be shown for indices of state schizotypy. Our results support findings that both state and trait positive schizotypy explain significant variance in "seeing things that are not there" and that the properties of individual stimuli have additional strong effects on the false-positive hit rates. Finally, we found that verbal intelligence and positive schizotypy interact with stimulus-ambiguity in the production of false-positive perceptions.

  8. The probability of false positives in zero-dimensional analyses of one-dimensional kinematic, force and EMG trajectories.

    Science.gov (United States)

    Pataky, Todd C; Vanrenterghem, Jos; Robinson, Mark A

    2016-06-14

    A false positive is the mistake of inferring an effect when none exists, and although α controls the false positive (Type I error) rate in classical hypothesis testing, a given α value is accurate only if the underlying model of randomness appropriately reflects experimentally observed variance. Hypotheses pertaining to one-dimensional (1D) (e.g. time-varying) biomechanical trajectories are most often tested using a traditional zero-dimensional (0D) Gaussian model of randomness, but variance in these datasets is clearly 1D. The purpose of this study was to determine the likelihood that analyzing smooth 1D data with a 0D model of variance will produce false positives. We first used random field theory (RFT) to predict the probability of false positives in 0D analyses. We then validated RFT predictions via numerical simulations of smooth Gaussian 1D trajectories. Results showed that, across a range of public kinematic, force/moment and EMG datasets, the median false positive rate was 0.382 and not the assumed α=0.05, even for a simple two-sample t test involving N=10 trajectories per group. The median false positive rate for experiments involving three-component vector trajectories was p=0.764. This rate increased to p=0.945 for two three-component vector trajectories, and to p=0.999 for six three-component vectors. This implies that experiments involving vector trajectories have a high probability of yielding 0D statistical significance when there is, in fact, no 1D effect. Either (a) explicit a priori identification of 0D variables or (b) adoption of 1D methods can more tightly control α. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Way forward in case of a false positive in vitro genotoxicity result for a cosmetic substance?

    Science.gov (United States)

    Doktorova, Tatyana Y; Ates, Gamze; Vinken, Mathieu; Vanhaecke, Tamara; Rogiers, Vera

    2014-02-01

    The currently used regulatory in vitro mutagenicity/genotoxicity test battery has a high sensitivity for detecting genotoxicants, but it suffers from a large number of irrelevant positive results (i.e. low specificity) thereby imposing the need for additional follow-up by in vitro and/or in vivo genotoxicity tests. This could have a major impact on the cosmetic industry in Europe, seen the imposed animal testing and marketing bans on cosmetics and their ingredients. Afflicted, but safe substances could therefore be lost. Using the example of triclosan, a cosmetic preservative, we describe here the potential applicability of a human toxicogenomics-based in vitro assay as a potential mechanistically based follow-up test for positive in vitro genotoxicity results. Triclosan shows a positive in vitro chromosomal aberration test, but is negative during in vivo follow-up tests. Toxicogenomics analysis unequivocally shows that triclosan is identified as a compound acting through non-DNA reactive mechanisms. This proof-of-principle study illustrates the potential of genome-wide transcriptomics data in combination with in vitro experimentation as a possible weight-of-evidence follow-up approach for de-risking a positive outcome in a standard mutagenicity/genotoxicity battery. As such a substantial number of cosmetic compounds wrongly identified as genotoxicants could be saved for the future. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. False-Positive Rate of AKI Using Consensus Creatinine–Based Criteria

    Science.gov (United States)

    Lin, Jennie; Fernandez, Hilda; Shashaty, Michael G.S.; Negoianu, Dan; Testani, Jeffrey M.; Berns, Jeffrey S.; Parikh, Chirag R.

    2015-01-01

    Background and objectives Use of small changes in serum creatinine to diagnose AKI allows for earlier detection but may increase diagnostic false–positive rates because of inherent laboratory and biologic variabilities of creatinine. Design, setting, participants, & measurements We examined serum creatinine measurement characteristics in a prospective observational clinical reference cohort of 2267 adult patients with AKI by Kidney Disease Improving Global Outcomes creatinine criteria and used these data to create a simulation cohort to model AKI false–positive rates. We simulated up to seven successive blood draws on an equal population of hypothetical patients with unchanging true serum creatinine values. Error terms generated from laboratory and biologic variabilities were added to each simulated patient’s true serum creatinine value to obtain the simulated measured serum creatinine for each blood draw. We determined the proportion of patients who would be erroneously diagnosed with AKI by Kidney Disease Improving Global Outcomes creatinine criteria. Results Within the clinical cohort, 75.0% of patients received four serum creatinine draws within at least one 48-hour period during hospitalization. After four simulated creatinine measurements that accounted for laboratory variability calculated from assay characteristics and 4.4% of biologic variability determined from the clinical cohort and publicly available data, the overall false–positive rate for AKI diagnosis was 8.0% (interquartile range =7.9%–8.1%), whereas patients with true serum creatinine ≥1.5 mg/dl (representing 21% of the clinical cohort) had a false–positive AKI diagnosis rate of 30.5% (interquartile range =30.1%–30.9%) versus 2.0% (interquartile range =1.9%–2.1%) in patients with true serum creatinine values false–positive rates caused by inherent variability of serum creatinine at higher baseline values, potentially misclassifying patients with CKD in AKI studies. PMID

  11. False Advertising

    OpenAIRE

    Rhodes, Andrew; Wilson, Chris M

    2016-01-01

    There is widespread evidence that some firms use false advertising to overstate the value of their products. We consider a model in which a policymaker is able to punish such false claims. We characterize an equilibrium where false advertising actively influences rational buyers, and analyze the effects of policy under different welfare objectives. We establish precise conditions where policy optimally permits a positive level of false advertising, and show how these conditions vary intuitive...

  12. Internal Impingement of the Shoulder: A Risk of False Positive Test Outcomes in External Impingement Tests?

    Directory of Open Access Journals (Sweden)

    Tim Leschinger

    2017-01-01

    Full Text Available Background. External impingement tests are considered as being particularly reliable for identifying subacromial and coracoid shoulder impingement mechanisms. The purpose of the present study was to evaluate if these tests are likely to provoke an internal shoulder impingement mechanism which, in cases of a pathologic condition, can lead to a positive test result. Method. In 37 subjects, the mechanical contact between the glenoid rim and the rotator cuff (RC was measured quantitatively and qualitatively in external impingement test positions using an open MRI system. Results. Mechanical contact of the supraspinatus with the posterosuperior glenoid was present in 30 subjects in the Neer test. In the Hawkins test, the subscapularis was in contact with the anterosuperior glenoid in 33 subjects and the supraspinatus in 18. In the horizontal impingement test, anterosuperior contact of the supraspinatus with the glenoid was identified in 35 subjects. Conclusion. The Neer, Hawkins, and horizontal impingement tests are likely to provoke the mechanism of an internal shoulder impingement. A posterosuperior internal impingement mechanism is being provoked predominately in the Neer test. The Hawkins test narrows the distance between the insertions of the subscapularis and supraspinatus and the anterosuperior labrum, which leads to an anterosuperior impingement mechanism.

  13. False-Positive Rate Determination of Protein Target Discovery using a Covalent Modification- and Mass Spectrometry-Based Proteomics Platform

    Science.gov (United States)

    Strickland, Erin C.; Geer, M. Ariel; Hong, Jiyong; Fitzgerald, Michael C.

    2014-01-01

    Detection and quantitation of protein-ligand binding interactions is important in many areas of biological research. Stability of proteins from rates of oxidation (SPROX) is an energetics-based technique for identifying the proteins targets of ligands in complex biological mixtures. Knowing the false-positive rate of protein target discovery in proteome-wide SPROX experiments is important for the correct interpretation of results. Reported here are the results of a control SPROX experiment in which chemical denaturation data is obtained on the proteins in two samples that originated from the same yeast lysate, as would be done in a typical SPROX experiment except that one sample would be spiked with the test ligand. False-positive rates of 1.2-2.2 % and analysis of the isobaric mass tag (e.g., iTRAQ®) reporter ions used for peptide quantitation. Our results also suggest that technical replicates can be used to effectively eliminate such false positives that result from this random error, as is demonstrated in a SPROX experiment to identify yeast protein targets of the drug, manassantin A. The impact of ion purity in the tandem mass spectral analyses and of background oxidation on the false-positive rate of protein target discovery using SPROX is also discussed.

  14. False-positive cryptococcal antigen test associated with use of BBL Port-a-Cul transport vials.

    Science.gov (United States)

    Wilson, Deborah A; Sholtis, Mary; Parshall, Sharon; Hall, Gerri S; Procop, Gary W

    2011-02-01

    A total of 52 residual CSF and serum specimens, which were originally negative with the Cryptococcal Antigen Latex Agglutination System (CALAS), were shown to become falsely positive after placement in BBL Port-A-Cul anaerobic transport vials. This transport device, although excellent for specimen transportation for subsequent culture, should not be used if cryptococcal antigen testing is needed.

  15. False-Positive Cryptococcal Antigen Test Associated with Use of BBL Port-A-Cul Transport Vials▿

    Science.gov (United States)

    Wilson, Deborah A.; Sholtis, Mary; Parshall, Sharon; Hall, Gerri S.; Procop, Gary W.

    2011-01-01

    A total of 52 residual CSF and serum specimens, which were originally negative with the Cryptococcal Antigen Latex Agglutination System (CALAS), were shown to become falsely positive after placement in BBL Port-A-Cul anaerobic transport vials. This transport device, although excellent for specimen transportation for subsequent culture, should not be used if cryptococcal antigen testing is needed. PMID:21159939

  16. Reduction of false positives in the detection of architectural distortion in mammograms by using a geometrically constrained phase portrait model

    International Nuclear Information System (INIS)

    Ayres, Fabio J.; Rangayyan, Rangaraj M.

    2007-01-01

    Objective One of the commonly missed signs of breast cancer is architectural distortion. We have developed techniques for the detection of architectural distortion in mammograms, based on the analysis of oriented texture through the application of Gabor filters and a linear phase portrait model. In this paper, we propose constraining the shape of the general phase portrait model as a means to reduce the false-positive rate in the detection of architectural distortion. Material and methods The methods were tested with one set of 19 cases of architectural distortion and 41 normal mammograms, and with another set of 37 cases of architectural distortion. Results Sensitivity rates of 84% with 4.5 false positives per image and 81% with 10 false positives per image were obtained for the two sets of images. Conclusion The adoption of a constrained phase portrait model with a symmetric matrix and the incorporation of its condition number in the analysis resulted in a reduction in the false-positive rate in the detection of architectural distortion. The proposed techniques, dedicated for the detection and localization of architectural distortion, should lead to efficient detection of early signs of breast cancer. (orig.)

  17. A False Positive I-131 Metastatic Survey Caused by Radioactive Iodine Uptake by a Benign Thymic Cyst

    Directory of Open Access Journals (Sweden)

    Avneet K. Singh

    2017-01-01

    Full Text Available Thyroid carcinoma is the most common endocrine malignancy in the United States with increasing incidence and diagnosis but stable mortality. Differentiated thyroid cancer rarely presents with distant metastases and is associated with a low risk of morbidity and mortality. Despite this, current protocols recommend remnant ablation with radioactive iodine and evaluation for local and distant metastasis in some patients with higher risk disease. There are several case reports of false positive results of metastatic surveys that are either normal physiologic variants or other pathological findings. Most false positive findings are associated with tissue that has physiologic increased uptake of I-131, such as breast tissue or lung tissue; pathological findings such as thymic cysts are also known to have increased uptake. Our case describes a rare finding of a thymic cyst found on a false positive I-131 metastatic survey. The patient was taken for surgical excision and the final pathology was a benign thymic cyst. Given that pulmonary metastases of differentiated thyroid cancer are rare, thymic cysts, though also rare, must be part of the differential diagnosis for false positive findings on an I-131 survey.

  18. The cumulative risk of false-positive screening results across screening centres in the Norwegian Breast Cancer Screening Program

    Energy Technology Data Exchange (ETDEWEB)

    Roman, M., E-mail: Marta.Roman@kreftregisteret.no [Cancer Registry of Norway, Oslo (Norway); Department of Women and Children’s Health, Oslo University Hospital, Oslo (Norway); Skaane, P., E-mail: PERSK@ous-hf.no [Department of Radiology, Oslo University Hospital Ullevaal, University of Oslo, Oslo (Norway); Hofvind, S., E-mail: Solveig.Hofvind@kreftregisteret.no [Cancer Registry of Norway, Oslo (Norway); Oslo and Akershus University College of Applied Sciences, Faculty of Health Science, Oslo (Norway)

    2014-09-15

    Highlights: • We found variation in early performance measures across screening centres. • Radiologists’ performance may play a key role in the variability. • Potential to improve the effectiveness of breast cancer screening programs. • Continuous surveillance of screening centres and radiologists is essential. - Abstract: Background: Recall for assessment in mammographic screening entails an inevitable number of false-positive screening results. This study aimed to investigate the variation in the cumulative risk of a false positive screening result and the positive predictive value across the screening centres in the Norwegian Breast Cancer Screening Program. Methods: We studied 618,636 women aged 50–69 years who underwent 2,090,575 screening exams (1996–2010. Recall rate, positive predictive value, rate of screen-detected cancer, and the cumulative risk of a false positive screening result, without and with invasive procedures across the screening centres were calculated. Generalized linear models were used to estimate the probability of a false positive screening result and to compute the cumulative false-positive risk for up to ten biennial screening examinations. Results: The cumulative risk of a false-positive screening exam varied from 10.7% (95% CI: 9.4–12.0%) to 41.5% (95% CI: 34.1–48.9%) across screening centres, with a highest to lowest ratio of 3.9 (95% CI: 3.7–4.0). The highest to lowest ratio for the cumulative risk of undergoing an invasive procedure with a benign outcome was 4.3 (95% CI: 4.0–4.6). The positive predictive value of recall varied between 12.0% (95% CI: 11.0–12.9%) and 19.9% (95% CI: 18.3–21.5%), with a highest to lowest ratio of 1.7 (95% CI: 1.5–1.9). Conclusions: A substantial variation in the performance measures across the screening centres in the Norwegian Breast Cancer Screening Program was identified, despite of similar administration, procedures, and quality assurance requirements. Differences in the

  19. The cumulative risk of false-positive screening results across screening centres in the Norwegian Breast Cancer Screening Program

    International Nuclear Information System (INIS)

    Roman, M.; Skaane, P.; Hofvind, S.

    2014-01-01

    Highlights: • We found variation in early performance measures across screening centres. • Radiologists’ performance may play a key role in the variability. • Potential to improve the effectiveness of breast cancer screening programs. • Continuous surveillance of screening centres and radiologists is essential. - Abstract: Background: Recall for assessment in mammographic screening entails an inevitable number of false-positive screening results. This study aimed to investigate the variation in the cumulative risk of a false positive screening result and the positive predictive value across the screening centres in the Norwegian Breast Cancer Screening Program. Methods: We studied 618,636 women aged 50–69 years who underwent 2,090,575 screening exams (1996–2010. Recall rate, positive predictive value, rate of screen-detected cancer, and the cumulative risk of a false positive screening result, without and with invasive procedures across the screening centres were calculated. Generalized linear models were used to estimate the probability of a false positive screening result and to compute the cumulative false-positive risk for up to ten biennial screening examinations. Results: The cumulative risk of a false-positive screening exam varied from 10.7% (95% CI: 9.4–12.0%) to 41.5% (95% CI: 34.1–48.9%) across screening centres, with a highest to lowest ratio of 3.9 (95% CI: 3.7–4.0). The highest to lowest ratio for the cumulative risk of undergoing an invasive procedure with a benign outcome was 4.3 (95% CI: 4.0–4.6). The positive predictive value of recall varied between 12.0% (95% CI: 11.0–12.9%) and 19.9% (95% CI: 18.3–21.5%), with a highest to lowest ratio of 1.7 (95% CI: 1.5–1.9). Conclusions: A substantial variation in the performance measures across the screening centres in the Norwegian Breast Cancer Screening Program was identified, despite of similar administration, procedures, and quality assurance requirements. Differences in the

  20. Evaluation of Patients with an Apparent False Positive Stool DNA Test: The Role of Repeat Stool DNA Testing.

    Science.gov (United States)

    Cooper, Gregory S; Markowitz, Sanford D; Chen, Zhengyi; Tuck, Missy; Willis, Joseph E; Berger, Barry M; Brenner, Dean E; Li, Li

    2018-03-07

    There is uncertainty as to the appropriate follow-up of patients who test positive on multimarker stool DNA (sDNA) testing and have a colonoscopy without neoplasia. To determine the prevalence of missed colonic or occult upper gastrointestinal neoplasia in patients with an apparent false positive sDNA. We prospectively identified 30 patients who tested positive with a commercially available sDNA followed by colonoscopy without neoplastic lesions. Patients were invited to undergo repeat sDNA at 11-29 months after the initial test followed by repeat colonoscopy and upper endoscopy. We determined the presence of neoplastic lesions on repeat evaluation stratified by results of repeat sDNA. Twelve patients were restudied. Seven patients had a negative second sDNA test and a normal second colonoscopy and upper endoscopy. In contrast, 5 of 12 subjects had a persistently positive second sDNA test, and 3 had positive findings, including a 3-cm sessile transverse colon adenoma with high-grade dysplasia, a 2-cm right colon sessile serrated adenoma with dysplasia, and a nonadvanced colon adenoma (p = 0.045). These corresponded to a positive predictive value of 0.60 (95% CI 0.17-1.00) and a negative predictive value of 1.00 (95% CI 1.00-1.00) for the second sDNA test. In addition, the medical records of all 30 subjects with apparent false positive testing were reviewed and no documented cases of malignant tumors were recorded. Repeat positive sDNA testing may identify a subset of patients with missed or occult colorectal neoplasia after negative colonoscopy for an initially positive sDNA. High-quality colonoscopy with careful attention to the right colon in patients with positive sDNA is critically important and may avoid false negative colonoscopy.

  1. Case of false positive scanning observed after radiation therapy for orbital tumor

    Energy Technology Data Exchange (ETDEWEB)

    Ohara, H [Gifu Prefectural Tajimi Hospital (Japan); Nakamura, K; Maeda, S; Watanabe, R; Miyajima, T

    1978-12-01

    A report was made of 56-year-old female patient of abducensparesis. In the early stage the cause remained undetermined with nothing abnormal noted in scintigraphy. Diplopia disappeared once, but right, exophalmus relapsed. In gammaencepharography, a hot spot was noted in the orbita, sinus ethmoidalis and sirus sphenoidalis. In an operation, squamous cell carcinoma was removed and radiation therapy was performed (total dose of 3520 r) and, three months later a scintigraphy disclosed a high spot of /sup 203/Hg uptake ratio in the right orbita and its lower portions. The biopsy of these portions disclosed a necrotic tissue instead of a tumor. In scintigraphy after radiation therapy against the tumor, it was reported that a positive scintigraphy was present because of the vascular trouble of said portions, although the tumor had disappeared. Attention should be given as well as an opinion of high density together with the examination by CT, especially as to enhancement.

  2. A Case of False-Positive Mycobacterium tuberculosis Caused by Mycobacterium celatum

    Directory of Open Access Journals (Sweden)

    Edward Gildeh

    2016-01-01

    Full Text Available Mycobacterium celatum is a nontuberculous mycobacterium shown to cause symptoms similar to pulmonary M. tuberculosis. Certain strains have been shown to cross-react with the probes used to detect M. tuberculosis, making this a diagnostic challenge. We present a 56-year-old gentleman who developed signs and symptoms of lung infection with computed tomography scan of the chest showing right lung apex cavitation. Serial sputum samples were positive for acid-fast bacilli and nucleic acid amplification testing identified M. tuberculosis ribosomal RNA, resulting in treatment initiation. Further testing with high performance liquid chromatography showed a pattern consistent with M. celatum. This case illustrates the potential for M. celatum to mimic M. tuberculosis in both its clinical history and laboratory testing due to the identical oligonucleotide sequence contained in both. An increasing number of case reports suggest that early reliable differentiation could reduce unnecessary treatment and public health intervention associated with misdiagnosed tuberculosis.

  3. Distinguishing Binders from False Positives by Free Energy Calculations: Fragment Screening Against the Flap Site of HIV Protease

    Science.gov (United States)

    2015-01-01

    Molecular docking is a powerful tool used in drug discovery and structural biology for predicting the structures of ligand–receptor complexes. However, the accuracy of docking calculations can be limited by factors such as the neglect of protein reorganization in the scoring function; as a result, ligand screening can produce a high rate of false positive hits. Although absolute binding free energy methods still have difficulty in accurately rank-ordering binders, we believe that they can be fruitfully employed to distinguish binders from nonbinders and reduce the false positive rate. Here we study a set of ligands that dock favorably to a newly discovered, potentially allosteric site on the flap of HIV-1 protease. Fragment binding to this site stabilizes a closed form of protease, which could be exploited for the design of allosteric inhibitors. Twenty-three top-ranked protein–ligand complexes from AutoDock were subject to the free energy screening using two methods, the recently developed binding energy analysis method (BEDAM) and the standard double decoupling method (DDM). Free energy calculations correctly identified most of the false positives (≥83%) and recovered all the confirmed binders. The results show a gap averaging ≥3.7 kcal/mol, separating the binders and the false positives. We present a formula that decomposes the binding free energy into contributions from the receptor conformational macrostates, which provides insights into the roles of different binding modes. Our binding free energy component analysis further suggests that improving the treatment for the desolvation penalty associated with the unfulfilled polar groups could reduce the rate of false positive hits in docking. The current study demonstrates that the combination of docking with free energy methods can be very useful for more accurate ligand screening against valuable drug targets. PMID:25189630

  4. False-positive pregnancy test after transfusion of solvent/detergent-treated plasma.

    Science.gov (United States)

    Jilma-Stohlawetz, Petra; Wreford-Bush, Tim; Mills, Francesca; Davidson, Fiona; Kursten, Friedrich W; Jilma, Bernd; Birchall, Janet

    2017-12-01

    The transmission of pathogens, antibodies, and proteins is a possible consequence of blood product transfusion. A female patient had an unexpected positive serum β-human chorionic gonadotropin result, indicative of pregnancy, after she had received a transfusion with 1 unit of platelet concentrate, 4 units of red blood cells, and 4 units of pooled solvent/detergent-treated plasma (Octaplas). To investigate the possibility of passive transfusion of β-human chorionic gonadotropin from the plasma transfusion, one additional unit from the same batch was thawed and analyzed. To validate the β-human chorionic gonadotropin assay for use in solvent/detergent-treated plasma and to investigate any interference in the assay, dilution experiments were performed using the implicated plasma batch diluted with male and non-pregnant female sera. Also, plasma from a known pregnant woman was diluted with Octaplas (tested negative for β-human chorionic gonadotropin) and with a male serum to validate the assay for use in solvent/detergent-treated plasma. The implicated solvent/detergent-treated plasma had a mean β-human chorionic gonadotropin level of 91.5 mIU/mL. Results from the dilution experiments revealed an excellent correlation (r > 0.99) between β-human chorionic gonadotropin measurement in solvent/detergent-treated plasma and male serum and no over or under recovery of the expected results. Further measurements of β-human chorionic gonadotropin levels in the female recipient revealed an estimated half-life of 6 hours. This case demonstrates the importance of considering the possibility of passive transmission of analytes to a patient from the transfusion of blood products. Furthermore, the measurement of β-human chorionic gonadotropin is valid in solvent/detergent-treated plasma using a Roche Cobas analyzer. © 2017 AABB.

  5. Predicting residue contacts using pragmatic correlated mutations method: reducing the false positives

    Directory of Open Access Journals (Sweden)

    Alexov Emil G

    2006-11-01

    Full Text Available Abstract Background Predicting residues' contacts using primary amino acid sequence alone is an important task that can guide 3D structure modeling and can verify the quality of the predicted 3D structures. The correlated mutations (CM method serves as the most promising approach and it has been used to predict amino acids pairs that are distant in the primary sequence but form contacts in the native 3D structure of homologous proteins. Results Here we report a new implementation of the CM method with an added set of selection rules (filters. The parameters of the algorithm were optimized against fifteen high resolution crystal structures with optimization criterion that maximized the confidentiality of the predictions. The optimization resulted in a true positive ratio (TPR of 0.08 for the CM without filters and a TPR of 0.14 for the CM with filters. The protocol was further benchmarked against 65 high resolution structures that were not included in the optimization test. The benchmarking resulted in a TPR of 0.07 for the CM without filters and to a TPR of 0.09 for the CM with filters. Conclusion Thus, the inclusion of selection rules resulted to an overall improvement of 30%. In addition, the pair-wise comparison of TPR for each protein without and with filters resulted in an average improvement of 1.7. The methodology was implemented into a web server http://www.ces.clemson.edu/compbio/recon that is freely available to the public. The purpose of this implementation is to provide the 3D structure predictors with a tool that can help with ranking alternative models by satisfying the largest number of predicted contacts, as well as it can provide a confidence score for contacts in cases where structure is known.

  6. Restricted Boltzmann machines based oversampling and semi-supervised learning for false positive reduction in breast CAD.

    Science.gov (United States)

    Cao, Peng; Liu, Xiaoli; Bao, Hang; Yang, Jinzhu; Zhao, Dazhe

    2015-01-01

    The false-positive reduction (FPR) is a crucial step in the computer aided detection system for the breast. The issues of imbalanced data distribution and the limitation of labeled samples complicate the classification procedure. To overcome these challenges, we propose oversampling and semi-supervised learning methods based on the restricted Boltzmann machines (RBMs) to solve the classification of imbalanced data with a few labeled samples. To evaluate the proposed method, we conducted a comprehensive performance study and compared its results with the commonly used techniques. Experiments on benchmark dataset of DDSM demonstrate the effectiveness of the RBMs based oversampling and semi-supervised learning method in terms of geometric mean (G-mean) for false positive reduction in Breast CAD.

  7. Usefulness of exercise ECG test with nitroglycerin and exercise cardiac scintigraphy in patients with false positive exercise ECG test

    International Nuclear Information System (INIS)

    Moritani, Kohshiro

    1984-01-01

    The purpose of this study is to evaluate the clinical usefulness of exercise (Ex) ECG test with sublingual nitroglycerin (NTG) and Ex cardiac scintigraphy in differentiating false positive responses from true positive responses of Ex ECG test. We examined 7 pts (age : 46+-7 years) with true positive Ex ECG test (TP) and 8 pts (age : 55+-10 years) with false positive Ex ECG test (FP). TP had significant coronary artery disease and FP did not. Ex test was done by multistage ergometer test. In 5 pts of TP and all pts of FP, Ex cardiac scintigraphy was performed. In TP, Ex cardiac scintigraphy revealed reversible perfusion deficit, but not in FP. NTG was administered 3 minutes before Ex test was started. Ex test with NTG was terminated at the same load as Ex test without NTG. Pressure-rate products at the end point of Ex test did not show significant difference between Ex test without NTG and that with NTG (TP: 203x10 2 , 213x10 2 , FP: 196x10 2 , 206x10 2 , respectively). In 7 pts of FP, ST depression in Ex test without NTG was not improved in Ex test with NTG. On the other hand, in all pts of TP, ST depression seen in Ex test without NTG, was not observed in Ex test with NTG. It may be concluded that Ex cardiac scintigraphy is diagnostic for differentiation of false positive responses from true positive responses of Ex ECG test, as well as Ex ECG test with NTG is. (author)

  8. Decisions to shoot in a weapon identification task: The influence of cultural stereotypes and perceived threat on false positive errors.

    Science.gov (United States)

    Fleming, Kevin K; Bandy, Carole L; Kimble, Matthew O

    2010-01-01

    The decision to shoot a gun engages executive control processes that can be biased by cultural stereotypes and perceived threat. The neural locus of the decision to shoot is likely to be found in the anterior cingulate cortex (ACC), where cognition and affect converge. Male military cadets at Norwich University (N=37) performed a weapon identification task in which they made rapid decisions to shoot when images of guns appeared briefly on a computer screen. Reaction times, error rates, and electroencephalogram (EEG) activity were recorded. Cadets reacted more quickly and accurately when guns were primed by images of Middle-Eastern males wearing traditional clothing. However, cadets also made more false positive errors when tools were primed by these images. Error-related negativity (ERN) was measured for each response. Deeper ERNs were found in the medial-frontal cortex following false positive responses. Cadets who made fewer errors also produced deeper ERNs, indicating stronger executive control. Pupil size was used to measure autonomic arousal related to perceived threat. Images of Middle-Eastern males in traditional clothing produced larger pupil sizes. An image of Osama bin Laden induced the largest pupil size, as would be predicted for the exemplar of Middle East terrorism. Cadets who showed greater increases in pupil size also made more false positive errors. Regression analyses were performed to evaluate predictions based on current models of perceived threat, stereotype activation, and cognitive control. Measures of pupil size (perceived threat) and ERN (cognitive control) explained significant proportions of the variance in false positive errors to Middle-Eastern males in traditional clothing, while measures of reaction time, signal detection response bias, and stimulus discriminability explained most of the remaining variance.

  9. False-positive findings in mammography screening induces short-term distress - breast cancer-specific concern prevails longer

    DEFF Research Database (Denmark)

    Aro, A R; Pilvikki Absetz, S; van Elderen, T M

    2000-01-01

    The aim of this study was to examine psychological distress in a mammography screening process as a consequence of screening after adjusting for background, personality and prescreening distress. Subjects, aged 50 years, were invitees at their first screening. There were three groups; normal find...... perceived breast cancer risk and susceptibility. Distress related to screening and false-positive findings seems to be moderate, but prevailing cancer-specific concerns call for improvements in screening programmes....

  10. False positive results occurring in a radioimmunoassay for hepatitis A IgM antibody of the IgM class

    Energy Technology Data Exchange (ETDEWEB)

    Bucens, M R; Pietroboni, G R; Harnett, G B [Virus Lab., Combined Microbiology Service, Queen Elizabeth II Medical Centre, Perth, Western Australia

    1983-12-01

    The diagnosis of hepatitis A infection is usually based on the presence of hepatitis A specific IgM in a single serum sample. The fortuitous observation in one patient that this reactivity was apparently still present 19 mth after her original illness led to the discovery that the ABBOTT HAVAB-M kit method may produce false positive results. A series of patients who had previously had hepatitis A was retested and false positive results were found in 6% of this group. Control groups consisted of patients with other acute and chronic liver disorders and other acute viral diseases. No reactivity was detected in the control sera. Sucrose gradient fractionation revealed that the factor responsible for the false positive results was associated only with serum fractions containing IgA and IgG and that it could be removed by absorption of sera with staphylococcal protein A but not by absorption with streptococcus AR1 or by 2-mercaptoethanol treatment. It was concluded that following hepatitis A infection some patients produce a rheumatoid factor-like substance (not of IgM class) which is cleared from the serum in 2-3 yr. The presence of this factor may lead to a misdiagnosis in patients presenting with jaundice.

  11. One Hundred False-Positive Amphetamine Specimens Characterized by Liquid Chromatography Time-of-Flight Mass Spectrometry.

    Science.gov (United States)

    Marin, Stephanie J; Doyle, Kelly; Chang, Annie; Concheiro-Guisan, Marta; Huestis, Marilyn A; Johnson-Davis, Kamisha L

    2016-01-01

    Some amphetamine (AMP) and ecstacy (MDMA) urine immunoassay (IA) kits are prone to false-positive results due to poor specificity of the antibody. We employed two techniques, high-resolution mass spectrometry (HRMS) and an in silico structure search, to identify compounds likely to cause false-positive results. Hundred false-positive IA specimens for AMP and/or MDMA were analyzed by an Agilent 6230 time-of-flight (TOF) mass spectrometer. Separately, SciFinder (Chemical Abstracts) was used as an in silico structure search to generate a library of compounds that are known to cross-react with AMP/MDMA IAs. Chemical formulas and exact masses of 145 structures were then compared against masses identified by TOF. Compounds known to have cross-reactivity with the IAs were identified in the structure-based search. The chemical formulas and exact masses of 145 structures (of 20 chemical formulas) were compared against masses identified by TOF. Urine analysis by HRMS correlates accurate mass with chemical formulae, but provides little information regarding compound structure. Structural data of targeted antigens can be utilized to correlate HRMS-derived chemical formulas with structural analogs. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Immunoglobulin M

    DEFF Research Database (Denmark)

    Pleass, Richard J; Moore, Shona C; Stevenson, Liz

    2016-01-01

    Immunoglobulin M (IgM) is an ancient antibody class that is found in all vertebrates, with the exception of coelacanths, and is indispensable in both innate and adaptive immunity. The equally ancient human malaria parasite, Plasmodium falciparum, formed an intimate relationship with IgM with whic...

  13. Occurrence of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae isolates.

    Directory of Open Access Journals (Sweden)

    Peng Wang

    Full Text Available Adequate detection of the production of carbapenemase in Enterobacteriaceae isolates is crucial for infection control measures and the appropriate choice of antimicrobial therapy. In this study, we investigated the frequency of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae clinical isolates by the modified Hodge test (MHT. Three hundred and one E. coli and K. pneumoniae clinical isolates were investigated. All produced extended spectrum β-lactamases (ESBLs but were susceptible to carbapenems. Antimicrobial susceptibility testing was performed by the disk diffusion and agar dilution methods. The MHT was performed using the standard inoculum of test organisms recommended by the CLSI. Genes that encoded ESBLs and carbapenemases were identified by PCR and DNA sequencing. Among the 301 clinical isolates, none of the isolates conformed to the criteria for carbapenemase screening recommended by the CLSI. The susceptibility rates for imipenem, meropenem, and ertapenem all were 100.0%, 100.0%, and 100.0%, respectively. Of the 301 E. coli and K. pneumoniae isolates, none produced carbapenemase. The MHT gave a positive result for 3.3% (10/301 of the isolates. False positive results can occur when the MHT is used to detect carbapenemase in ESBL-producing isolates and clinical laboratories must be aware of this fact.

  14. Multi-scale textural feature extraction and particle swarm optimization based model selection for false positive reduction in mammography.

    Science.gov (United States)

    Zyout, Imad; Czajkowska, Joanna; Grzegorzek, Marcin

    2015-12-01

    The high number of false positives and the resulting number of avoidable breast biopsies are the major problems faced by current mammography Computer Aided Detection (CAD) systems. False positive reduction is not only a requirement for mass but also for calcification CAD systems which are currently deployed for clinical use. This paper tackles two problems related to reducing the number of false positives in the detection of all lesions and masses, respectively. Firstly, textural patterns of breast tissue have been analyzed using several multi-scale textural descriptors based on wavelet and gray level co-occurrence matrix. The second problem addressed in this paper is the parameter selection and performance optimization. For this, we adopt a model selection procedure based on Particle Swarm Optimization (PSO) for selecting the most discriminative textural features and for strengthening the generalization capacity of the supervised learning stage based on a Support Vector Machine (SVM) classifier. For evaluating the proposed methods, two sets of suspicious mammogram regions have been used. The first one, obtained from Digital Database for Screening Mammography (DDSM), contains 1494 regions (1000 normal and 494 abnormal samples). The second set of suspicious regions was obtained from database of Mammographic Image Analysis Society (mini-MIAS) and contains 315 (207 normal and 108 abnormal) samples. Results from both datasets demonstrate the efficiency of using PSO based model selection for optimizing both classifier hyper-parameters and parameters, respectively. Furthermore, the obtained results indicate the promising performance of the proposed textural features and more specifically, those based on co-occurrence matrix of wavelet image representation technique. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Recurrent/metastatic thyroid carcinomas false negative for serum thyroglobulin but positive by posttherapy I-131 whole body scans

    International Nuclear Information System (INIS)

    Park, Eun-Kyung; Lee, Dong Soo; Lee, Myung Chul; Chung, June-Key; Lim, Il Han; Park, Do Joon; Cho, Bo Youn

    2009-01-01

    Serum Tg and I-131 WBS have been used to detect recurrent and metastatic thyroid cancers postoperatively. Tg is known to be more sensitive than I-131 WBS, and therefore, false-negative WBS cases with elevated Tg levels are frequently found. However, the clinical characteristics of false-negative Tg cases with positive WBS have not been clarified. The authors evaluated 824 postoperative patients with differentiated thyroid carcinoma who underwent post-ablation/therapy I-131 WBS. Tg negativity was defined as a Tg level of ≤2 ng/mL without TgAb under thyroid-stimulating hormone stimulation. Remission, recurrence, and metastasis were confirmed using pathologic or clinically findings. Fifty-two patients (6.3%) with functioning metastasis and negativity for TgAb were Tg-negative and posttherapy I-131 WBS-positive (TgN group), and 128 patients with functioning metastases were Tg positive and WBS positive (TgP group). The TgN group consisted of 45 cases of cervical/mediastinal lymph node metastases (86.5%) and seven cases of distant metastasis to lung or bone by follow-up WBS. The TgN group demonstrated significantly higher profiles of regional involvement than the TgP group (P < 0.029). In 47 patients in the TgN group, metastatic uptake disappeared in 33, ameliorated in four, and persisted in ten during follow-up. A significant number of differentiated thyroid cancer patients were Tg-/TgAb-negative despite a positive WBS finding. Cervical and mediastinal lymph nodes were predominant sites of metastasis in the TgN group. WBS should be undertaken routinely as a complementary modality to detect functioning recurrence and metastasis regardless of serum Tg results. (orig.)

  16. Avoiding false positive antigen detection by flow cytometry on blood cell derived microparticles: the importance of an appropriate negative control.

    Directory of Open Access Journals (Sweden)

    Emerence Crompot

    Full Text Available Microparticles (MPs, also called microvesicles (MVs are plasma membrane-derived fragments with sizes ranging from 0.1 to 1μm. Characterization of these MPs is often performed by flow cytometry but there is no consensus on the appropriate negative control to use that can lead to false positive results.We analyzed MPs from platelets, B-cells, T-cells, NK-cells, monocytes, and chronic lymphocytic leukemia (CLL B-cells. Cells were purified by positive magnetic-separation and cultured for 48h. Cells and MPs were characterized using the following monoclonal antibodies (CD19,20 for B-cells, CD3,8,5,27 for T-cells, CD16,56 for NK-cells, CD14,11c for monocytes, CD41,61 for platelets. Isolated MPs were stained with annexin-V-FITC and gated between 300nm and 900nm. The latex bead technique was then performed for easy detection of MPs. Samples were analyzed by Transmission (TEM and Scanning Electron microscopy (SEM.Annexin-V positive events within a gate of 300-900nm were detected and defined as MPs. Our results confirmed that the characteristic antigens CD41/CD61 were found on platelet-derived-MPs validating our technique. However, for MPs derived from other cell types, we were unable to detect any antigen, although they were clearly expressed on the MP-producing cells in the contrary of several data published in the literature. Using the latex bead technique, we confirmed detection of CD41,61. However, the apparent expression of other antigens (already deemed positive in several studies was determined to be false positive, indicated by negative controls (same labeling was used on MPs from different origins.We observed that mother cell antigens were not always detected on corresponding MPs by direct flow cytometry or latex bead cytometry. Our data highlighted that false positive results could be generated due to antibody aspecificity and that phenotypic characterization of MPs is a difficult field requiring the use of several negative controls.

  17. Fish Immunoglobulins

    OpenAIRE

    Sara Mashoof; Michael F. Criscitiello

    2016-01-01

    The B cell receptor and secreted antibody are at the nexus of humoral adaptive immunity. In this review, we summarize what is known of the immunoglobulin genes of jawed cartilaginous and bony fishes. We focus on what has been learned from genomic or cDNA sequence data, but where appropriate draw upon protein, immunization, affinity and structural studies. Work from major aquatic model organisms and less studied comparative species are both included to define what is the rule for an immunoglob...

  18. [False positive results or what's the probability that a significant P-value indicates a true effect?

    Science.gov (United States)

    Cucherat, Michel; Laporte, Silvy

    2017-09-01

    The use of statistical test is central in the clinical trial. At the statistical level, obtaining a Pinformation about the plausibility of the existence of treatment effect. With "Pfalse positive is very high. This is the case if the power is low, if there is an inflation of the alpha risk or if the result is exploratory or chance discoveries. This possibility is important to take into consideration when interpreting the results of clinical trials in order to avoid pushing ahead significant results in appearance, but which are likely to be actually false positive results. Copyright © 2017 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.

  19. False-positive result when a diphenylcarbazide spot test is used on trivalent chromium-passivated zinc surfaces

    DEFF Research Database (Denmark)

    Reveko, Valeriia; Lampert, Felix; Din, Rameez Ud

    2018-01-01

    chromium passivation on zinc; however, subsequent analysis by XPS could not confirm the presence of chromium in a hexavalent state. Conclusions Unintended oxidation of DPC induced by atmospheric corrosion is suggested as a possible reason for the false-positive reaction of the DPC test on a trivalent......A colorimetric 1,5-diphenylcarbazide (DPC)-based spot test can be used to identify hexavalent chromium on various metallic and leather surfaces. DPC testing on trivalent chromium-passivated zinc surfaces has unexpectedly given positive results in some cases, apparently indicating the presence...... of hexavalent chromium; however, the presence of hexavalent chromium has never been confirmed with more sensitive and accurate test methods. Objectives To examine the presence of hexavalent chromium on trivalent chromium-passivated zinc surfaces with a DPC-based spot test. Methods A colorimetric DPC spot test...

  20. False-positive axillary lymph node on F-18 FDG PET/CT due to moxibustion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Shin Young; Lee, Sang Woo; Ahn, Byeong Cheol; Lee, Jae Tae [Kyungpook National University Hospital, Daegu (Korea, Republic of); Seo, Ji Hyoung [Inje University Haeundae Paik Hospital, Busan (Korea, Republic of)

    2010-12-15

    A 30-year-old female was diagnosed with papillary thyroid cancer and underwent total thyroidectomy and high-dose radioiodine ablation. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for recurrence detection of thyroid carcinoma was performed at 3 years after total thyroidectomy. Moxibustion is a traditional Chinese medicine therapy using moxa or the mugwort herb. Moxibustion is the burning of a small, thimble-sized, smoldering plug of dried leaves such as moxa or mugwort on the skin at an acupuncture point. Acupuncture and moxibustion induce hyperemia and a local inflammatory reaction. Complications associated with moxibustion such as skin bums or infection of the site have been reported previously. False-positive FDG uptake in PET may result from inflammation, infection, and variations in physiological uptake. In the present case, the hypermetabolic axillary lymph node disappeared without any treatment. Well-known of false-positive FDG uptake in axillary lymph noes such as arthritis of the upper extremity, extravasation of injected FDG, and vaccination were not found. Thus, left axillary lymph node uptake was

  1. False-positive axillary lymph node on F-18 FDG PET/CT due to moxibustion therapy

    International Nuclear Information System (INIS)

    Jeong, Shin Young; Lee, Sang Woo; Ahn, Byeong Cheol; Lee, Jae Tae; Seo, Ji Hyoung

    2010-01-01

    A 30-year-old female was diagnosed with papillary thyroid cancer and underwent total thyroidectomy and high-dose radioiodine ablation. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for recurrence detection of thyroid carcinoma was performed at 3 years after total thyroidectomy. Moxibustion is a traditional Chinese medicine therapy using moxa or the mugwort herb. Moxibustion is the burning of a small, thimble-sized, smoldering plug of dried leaves such as moxa or mugwort on the skin at an acupuncture point. Acupuncture and moxibustion induce hyperemia and a local inflammatory reaction. Complications associated with moxibustion such as skin bums or infection of the site have been reported previously. False-positive FDG uptake in PET may result from inflammation, infection, and variations in physiological uptake. In the present case, the hypermetabolic axillary lymph node disappeared without any treatment. Well-known of false-positive FDG uptake in axillary lymph noes such as arthritis of the upper extremity, extravasation of injected FDG, and vaccination were not found. Thus, left axillary lymph node uptake was

  2. False Positive Findings on I-131 WBS and SPECT/CT in Patients with History of Thyroid Cancer: Case Series

    Directory of Open Access Journals (Sweden)

    Zeina C. Hannoush

    2017-01-01

    Full Text Available Introduction. Although whole body scan (WBS with I-131 is a highly sensitive tool for detecting normal thyroid tissue and metastasis of differentiated thyroid cancer (DTC, it is not specific. Additional information, provided by single photon emission computed tomography combined with X-ray computed tomography (SPECT/CT and by the serum thyroglobulin level, is extremely useful for the interpretation of findings. Case Presentation. We report four cases of false positive WBS in patients with DTC: ovarian uptake corresponding to an endometrioma, scrotal uptake due to a spermatocele, rib-cage uptake due to an old fracture, and hepatic and renal uptake secondary to a granuloma and simple cyst, respectively. Conclusions. Trapping, organification, and storage of iodine are more prominent in thyroid tissue but not specific. Physiologic sodium-iodine symporter expression in other tissues explains some, but not all, of the WBS false positive cases. Other proposed etiologies are accumulation of radioiodine in inflamed organs, metabolism of radiodinated thyroid hormone, presence of radioiodine in body fluids, and contamination. In our cases nonthyroidal pathologies were suspected since the imaging findings were not corroborated by an elevated thyroglobulin level, which is considered a reliable tumor marker for most well-differentiated thyroid cancers. Clinicians should be aware of the potential pitfalls of WBS in DTC to avoid incorrect management.

  3. Impact of intermediate mammography assessment on the likelihood of false-positive results in breast cancer screening programmes

    Energy Technology Data Exchange (ETDEWEB)

    Ascunce, Nieves [Public Health Institute, CIBERESP, Navarra Breast Cancer Screening Programme, Pamplona (Spain); Instituto de Salud Publica, Navarra Breast Cancer Screening Programme, Pamplona (Spain); Ederra, Maria; Delfrade, Josu; Erdozain, Nieves [Public Health Institute, CIBERESP, Navarra Breast Cancer Screening Programme, Pamplona (Spain); Baroja, Araceli [Fundacion Rioja Salud, Logrono (Spain); Zubizarreta, Raquel [Public Health and Planning Directorate, Health Office, Galician Breast Cancer Screening Programme, Galicia (Spain); Salas, Dolores [General Directorate Public Health and Centre for Public Health Research (CSISP), Valencia (Spain); Castells, Xavier [Mar Teaching Hospital, CIBERESP, Department of Clinical Epidemiology, Barcelona (Spain)

    2012-02-15

    Breast cancer screening is offered to 100% of the target population in Spain and intermediate mammograms (IMs) are sometimes indicated. This study was aimed at analysing the frequency of IMs, the factors determining their recommendation, and their impact on the risk of false-positive results and the detection rate. Data from 3,471,307 mammograms from Spanish breast cancer screening programmes were included. 3.36% of the mammograms were IMs. The factors associated with the use of IMs were age, initial screening, previous invasive tests, a familial history of breast cancer and use of hormone replacement therapy. In screening episodes with an IM, the probability of a false-positive result was 13.74% (95% CI: 13.43-14.05), almost double that in episodes without IMs (6.02%, 95% CI 5.99-6.05). In young women with previous invasive procedures, a familial history of breast cancer or hormone replacement therapy use who were undergoing their initial screen, this probability was lower when IMs were performed. IMs always increased the detection rate. The factors prompting IMs should be characterised so that radiologists can systematise their recommendations according to the presence of the factors maximising the benefits and minimising the adverse effects of this procedure. (orig.)

  4. Impact of intermediate mammography assessment on the likelihood of false-positive results in breast cancer screening programmes

    International Nuclear Information System (INIS)

    Ascunce, Nieves; Ederra, Maria; Delfrade, Josu; Erdozain, Nieves; Baroja, Araceli; Zubizarreta, Raquel; Salas, Dolores; Castells, Xavier

    2012-01-01

    Breast cancer screening is offered to 100% of the target population in Spain and intermediate mammograms (IMs) are sometimes indicated. This study was aimed at analysing the frequency of IMs, the factors determining their recommendation, and their impact on the risk of false-positive results and the detection rate. Data from 3,471,307 mammograms from Spanish breast cancer screening programmes were included. 3.36% of the mammograms were IMs. The factors associated with the use of IMs were age, initial screening, previous invasive tests, a familial history of breast cancer and use of hormone replacement therapy. In screening episodes with an IM, the probability of a false-positive result was 13.74% (95% CI: 13.43-14.05), almost double that in episodes without IMs (6.02%, 95% CI 5.99-6.05). In young women with previous invasive procedures, a familial history of breast cancer or hormone replacement therapy use who were undergoing their initial screen, this probability was lower when IMs were performed. IMs always increased the detection rate. The factors prompting IMs should be characterised so that radiologists can systematise their recommendations according to the presence of the factors maximising the benefits and minimising the adverse effects of this procedure. (orig.)

  5. Immunoglobulin G4 (IgG4)-positive plasma cell infiltration is associated with the clinicopathologic traits and prognosis of pancreatic cancer after curative resection.

    Science.gov (United States)

    Liu, Qiaofei; Niu, Zheyu; Li, Yuan; Wang, Mengyi; Pan, Boju; Lu, Zhaohui; Liao, Quan; Zhao, Yupei

    2016-08-01

    Interactions between pancreatic cancer cells and inflammatory cells play crucial roles in the biological behavior of pancreatic cancer. Abundant infiltration of immunoglobulin G4 (IgG4)-positive plasma cells in the pancreas is the most significant feature of autoimmune pancreatitis; however, the clinical significance of IgG4-positive plasma cell infiltration in pancreatic cancer has not previously been reported. Herein, we analyzed intratumoral and peritumoral infiltrations of IgG4-positive plasma cells in 95 pancreatic cancer cases after curative resection. The correlations between IgG4-positive plasma cell infiltration and the clinicopathologic traits and overall survival of pancreatic cancer were investigated. IgG4-positive plasma cells were found in 86 % of tumor tissue samples compared with 69 % of peritumoral tissue samples (P = 0.0063). The high-level infiltration of intratumoral IgG4-positive plasma cells was positively correlated with poor histological grade (P = 0.017). The high-level infiltration of intratumoral IgG4-positive plasma cells was significantly correlated with worse prognosis (P = 0.01) in multivariate analysis. We further found that intratumoral M2-polarized tumor-associated macrophages (TAMs) were positively, linearly correlated with IgG4-positive plasma cells. In conclusion, IgG4-positive plasma cell infiltration is correlated with the clinicopathologic traits and overall survival of pancreatic cancer. High-level intratumoral infiltration of IgG4-positive plasma cells is an independent predictor for poor overall survival in pancreatic cancer patients after curative resection. Intratumoral M2-polarized TAMs probably induce IgG4-positive plasma cells.

  6. LOW FALSE POSITIVE RATE OF KEPLER CANDIDATES ESTIMATED FROM A COMBINATION OF SPITZER AND FOLLOW-UP OBSERVATIONS

    International Nuclear Information System (INIS)

    Désert, Jean-Michel; Brown, Timothy M.; Charbonneau, David; Torres, Guillermo; Fressin, François; Ballard, Sarah; Latham, David W.; Bryson, Stephen T.; Borucki, William J.; Knutson, Heather A.; Batalha, Natalie M.; Deming, Drake; Ford, Eric B.; Fortney, Jonathan J.; Gilliland, Ronald L.; Seager, Sara

    2015-01-01

    NASA’s Kepler mission has provided several thousand transiting planet candidates during the 4 yr of its nominal mission, yet only a small subset of these candidates have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the Spitzer Space Telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) among the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital, and planetary parameter space, and we observe their transits with Spitzer at 4.5 μm. We use these observations to measures the candidate’s transit depths and infrared magnitudes. An authentic planet produces an achromatic transit depth (neglecting the modest effect of limb darkening). Conversely a bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the transit depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5% and depending on the Kepler Objects of Interest. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3σ. This observational result, which uses the achromatic property of planetary transit signals that is not investigated

  7. LOW FALSE POSITIVE RATE OF KEPLER CANDIDATES ESTIMATED FROM A COMBINATION OF SPITZER AND FOLLOW-UP OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Désert, Jean-Michel; Brown, Timothy M. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Charbonneau, David; Torres, Guillermo; Fressin, François; Ballard, Sarah; Latham, David W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bryson, Stephen T.; Borucki, William J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Knutson, Heather A. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Batalha, Natalie M. [San Jose State University, San Jose, CA 95192 (United States); Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Ford, Eric B. [University of Florida, Gainesville, FL 32611 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Gilliland, Ronald L. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States); Seager, Sara, E-mail: desert@colorado.edu [Massachusetts Institute of Technology, Cambridge, MA 02159 (United States)

    2015-05-01

    NASA’s Kepler mission has provided several thousand transiting planet candidates during the 4 yr of its nominal mission, yet only a small subset of these candidates have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the Spitzer Space Telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) among the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital, and planetary parameter space, and we observe their transits with Spitzer at 4.5 μm. We use these observations to measures the candidate’s transit depths and infrared magnitudes. An authentic planet produces an achromatic transit depth (neglecting the modest effect of limb darkening). Conversely a bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the transit depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5% and depending on the Kepler Objects of Interest. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3σ. This observational result, which uses the achromatic property of planetary transit signals that is not investigated

  8. Trial sequential analysis reveals insufficient information size and potentially false positive results in many meta-analyses

    DEFF Research Database (Denmark)

    Brok, J.; Thorlund, K.; Gluud, C.

    2008-01-01

    in 80% (insufficient information size). TSA(15%) and TSA(LBHIS) found that 95% and 91% had absence of evidence. The remaining nonsignificant meta-analyses had evidence of lack of effect. CONCLUSION: TSA reveals insufficient information size and potentially false positive results in many meta......OBJECTIVES: To evaluate meta-analyses with trial sequential analysis (TSA). TSA adjusts for random error risk and provides the required number of participants (information size) in a meta-analysis. Meta-analyses not reaching information size are analyzed with trial sequential monitoring boundaries...... analogous to interim monitoring boundaries in a single trial. STUDY DESIGN AND SETTING: We applied TSA on meta-analyses performed in Cochrane Neonatal reviews. We calculated information sizes and monitoring boundaries with three different anticipated intervention effects of 30% relative risk reduction (TSA...

  9. False-positive liver scans due to portal hypertension: correlation with percutaneous transhepatic portograms in 33 patients

    International Nuclear Information System (INIS)

    Takayasu, K.; Moriyama, N.; Suzuki, M.; Yamada, T.; Fukutake, T.; Shima, Y.; Kobayashi, C.; Musha, H.; Okuda, K.

    1983-01-01

    Tc-99m-phytate scanning of the liver and percutaneous transhepatic catheterization of the portal vein were performed in 33 patients--26 with cirrhosis, 3 with chronic active hepatitis, 2 with idiopathic portal hypertension, and 2 with unresolved acute hepatitis. A discrete defect in the porta hepatis area was seen in 6 of 28 patients who had portal vein pressure above 200 mm H2O. In 5 of the 6 patients with a false-positive scan, the umbilical portion of the left portal vein branch was dilated (larger than 25 x 20 mm) on the portogram, with or without a patent paraumbilical vein. The anatomical basis of this phenomenon is discussed, and it is suggested that this area be given special attention

  10. Minimotif Miner 3.0: database expansion and significantly improved reduction of false-positive predictions from consensus sequences.

    Science.gov (United States)

    Mi, Tian; Merlin, Jerlin Camilus; Deverasetty, Sandeep; Gryk, Michael R; Bill, Travis J; Brooks, Andrew W; Lee, Logan Y; Rathnayake, Viraj; Ross, Christian A; Sargeant, David P; Strong, Christy L; Watts, Paula; Rajasekaran, Sanguthevar; Schiller, Martin R

    2012-01-01

    Minimotif Miner (MnM available at http://minimotifminer.org or http://mnm.engr.uconn.edu) is an online database for identifying new minimotifs in protein queries. Minimotifs are short contiguous peptide sequences that have a known function in at least one protein. Here we report the third release of the MnM database which has now grown 60-fold to approximately 300,000 minimotifs. Since short minimotifs are by their nature not very complex we also summarize a new set of false-positive filters and linear regression scoring that vastly enhance minimotif prediction accuracy on a test data set. This online database can be used to predict new functions in proteins and causes of disease.

  11. Benign thyroid and neck lesions mimicking malignancy with false positive findings on positron emission tomography-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ye Ri; Kim, Shin Young; Lee, Sang Mi [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Lee, Deuk Young [Dept. of Surgery, Younsei Angelot Women' s Clinic, Cheonan (Korea, Republic of)

    2017-02-15

    The increasing use of positron emission tomography-computed tomography (PET/CT) has led to the frequent detection of incidental thyroid and neck lesions with increased 18F-deoxyglucose (FDG) uptake. Although lesions with increased FDG uptake are commonly assumed to be malignant, benign lesions may also exhibit increased uptake. The purpose of this pictorial essay is to demonstrate that benign thyroid and neck lesions can produce false-positive findings on PET/CT, and to identify various difficulties in interpretation. It is crucial to be aware that differentiating between benign and malignant lesions is difficult in a considerable proportion of cases, when relying only on PET/CT findings. Correlation of PET/CT findings with additional imaging modalities is essential to avoid misdiagnosis.

  12. Systematic hybrid LOH: a new method to reduce false positives and negatives during screening of yeast gene deletion libraries

    DEFF Research Database (Denmark)

    Alvaro, D.; Sunjevaric, I.; Reid, R. J.

    2006-01-01

    We have developed a new method, systematic hybrid loss of heterozygosity, to facilitate genomic screens utilizing the yeast gene deletion library. Screening is performed using hybrid diploid strains produced through mating the library haploids with strains from a different genetic background......, to minimize the contribution of unpredicted recessive genetic factors present in the individual library strains. We utilize a set of strains where each contains a conditional centromere construct on one of the 16 yeast chromosomes that allows the destabilization and selectable loss of that chromosome. After...... complementation of any spurious recessive mutations in the library strain, facilitating attribution of the observed phenotype to the documented gene deletion and dramatically reducing false positive results commonly obtained in library screens. The systematic hybrid LOH method can be applied to virtually any...

  13. Automated detection of masses on whole breast volume ultrasound scanner: false positive reduction using deep convolutional neural network

    Science.gov (United States)

    Hiramatsu, Yuya; Muramatsu, Chisako; Kobayashi, Hironobu; Hara, Takeshi; Fujita, Hiroshi

    2017-03-01

    Breast cancer screening with mammography and ultrasonography is expected to improve sensitivity compared with mammography alone, especially for women with dense breast. An automated breast volume scanner (ABVS) provides the operator-independent whole breast data which facilitate double reading and comparison with past exams, contralateral breast, and multimodality images. However, large volumetric data in screening practice increase radiologists' workload. Therefore, our goal is to develop a computer-aided detection scheme of breast masses in ABVS data for assisting radiologists' diagnosis and comparison with mammographic findings. In this study, false positive (FP) reduction scheme using deep convolutional neural network (DCNN) was investigated. For training DCNN, true positive and FP samples were obtained from the result of our initial mass detection scheme using the vector convergence filter. Regions of interest including the detected regions were extracted from the multiplanar reconstraction slices. We investigated methods to select effective FP samples for training the DCNN. Based on the free response receiver operating characteristic analysis, simple random sampling from the entire candidates was most effective in this study. Using DCNN, the number of FPs could be reduced by 60%, while retaining 90% of true masses. The result indicates the potential usefulness of DCNN for FP reduction in automated mass detection on ABVS images.

  14. Computer-aided mass detection in mammography: False positive reduction via gray-scale invariant ranklet texture features

    International Nuclear Information System (INIS)

    Masotti, Matteo; Lanconelli, Nico; Campanini, Renato

    2009-01-01

    In this work, gray-scale invariant ranklet texture features are proposed for false positive reduction (FPR) in computer-aided detection (CAD) of breast masses. Two main considerations are at the basis of this proposal. First, false positive (FP) marks surviving our previous CAD system seem to be characterized by specific texture properties that can be used to discriminate them from masses. Second, our previous CAD system achieves invariance to linear/nonlinear monotonic gray-scale transformations by encoding regions of interest into ranklet images through the ranklet transform, an image transformation similar to the wavelet transform, yet dealing with pixels' ranks rather than with their gray-scale values. Therefore, the new FPR approach proposed herein defines a set of texture features which are calculated directly from the ranklet images corresponding to the regions of interest surviving our previous CAD system, hence, ranklet texture features; then, a support vector machine (SVM) classifier is used for discrimination. As a result of this approach, texture-based information is used to discriminate FP marks surviving our previous CAD system; at the same time, invariance to linear/nonlinear monotonic gray-scale transformations of the new CAD system is guaranteed, as ranklet texture features are calculated from ranklet images that have this property themselves by construction. To emphasize the gray-scale invariance of both the previous and new CAD systems, training and testing are carried out without any in-between parameters' adjustment on mammograms having different gray-scale dynamics; in particular, training is carried out on analog digitized mammograms taken from a publicly available digital database, whereas testing is performed on full-field digital mammograms taken from an in-house database. Free-response receiver operating characteristic (FROC) curve analysis of the two CAD systems demonstrates that the new approach achieves a higher reduction of FP marks

  15. False Positive Stress Testing: Does Endothelial Vascular Dysfunction Contribute to ST-Segment Depression in Women? A Pilot Study.

    Science.gov (United States)

    Sharma, Shilpa; Mehta, Puja K; Arsanjani, Reza; Sedlak, Tara; Hobel, Zachary; Shufelt, Chrisandra; Jones, Erika; Kligfield, Paul; Mortara, David; Laks, Michael; Diniz, Marcio; Bairey Merz, C Noel

    2018-06-19

    The utility of exercise-induced ST-segment depression for diagnosing ischemic heart disease (IHD) in women is unclear. Based on evidence that IHD pathophysiology in women involves coronary vascular dysfunction, we hypothesized that coronary vascular dysfunction contributes to exercise electrocardiography (Ex-ECG) ST-depression in the absence of obstructive CAD, so-called "false positive" results. We tested our hypothesis in a pilot study evaluating the relationship between peripheral vascular endothelial function and Ex-ECG. Twenty-nine asymptomatic women without cardiac risk factors underwent maximal Bruce protocol exercise treadmill testing and peripheral endothelial function assessment using peripheral arterial tonometry (Itamar EndoPAT 2000) to measure reactive hyperemia index (RHI). The relationship between RHI and Ex-ECG ST-segment depression was evaluated using logistic regression and differences in subgroups using two-tailed t-tests. Mean age was 54 ± 7 years, body mass index 25 ± 4 kg/m 2 , and RHI 2.51 ± 0.66. Three women (10%) had RHI less than 1.68, consistent with abnormal peripheral endothelial function, while 18 women (62%) met criteria for a positive Ex-ECG based on ST-segment depression in contiguous leads. Women with and without ST-segment depression had similar baseline and exercise vital signs, metabolic equivalents (METS) achieved, and RHI (all p>0.05). RHI did not predict ST-segment depression. Our pilot study demonstrates a high prevalence of exercise-induced ST-segment depression in asymptomatic, middle-aged, overweight women. Peripheral vascular endothelial dysfunction did not predict Ex-ECG ST-segment depression. Further work is needed to investigate the utility of vascular endothelial testing and Ex-ECG for IHD diagnostic and management purposes in women. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Feature-guided analysis for reduction of false positives in CAD of polyps for computed tomographic colonography

    International Nuclear Information System (INIS)

    Naeppi, Janne; Yoshida, Hiroyuki

    2003-01-01

    We evaluated the effect of our novel technique of feature-guided analysis of polyps on the reduction of false-positive (FP) findings generated by our computer-aided diagnosis (CAD) scheme for the detection of polyps from computed tomography colonographic data sets. The detection performance obtained by use of feature-guided analysis in the segmentation and feature analysis of polyp candidates was compared with that obtained by use of our previously employed fuzzy clustering technique. We also evaluated the effect of a feature called modified gradient concentration (MGC) on the detection performance. A total of 144 data sets, representing prone and supine views of 72 patients that included 14 patients with 21 colorectal polyps 5-25 mm in diameter, were used in the evaluation. At a 100% by-patient (95% by-polyp) detection sensitivity, the FP rate of our CAD scheme with feature-guided analysis based on round-robin evaluation was 1.3 (1.5) FP detections per patient. This corresponds to a 70-75 % reduction in the number of FPs obtained by use of fuzzy clustering at the same sensitivity levels. Application of the MGC feature instead of our previously used gradient concentration feature did not improve the detection result. The results indicate that feature-guided analysis is useful for achieving high sensitivity and a low FP rate in our CAD scheme

  17. Selective activation around the left occipito-temporal sulcus for words relative to pictures: individual variability or false positives?

    Science.gov (United States)

    Wright, Nicholas D; Mechelli, Andrea; Noppeney, Uta; Veltman, Dick J; Rombouts, Serge A R B; Glensman, Janice; Haynes, John-Dylan; Price, Cathy J

    2008-08-01

    We used high-resolution fMRI to investigate claims that learning to read results in greater left occipito-temporal (OT) activation for written words relative to pictures of objects. In the first experiment, 9/16 subjects performing a one-back task showed activation in > or =1 left OT voxel for words relative to pictures (P or =1 left OT voxel for words relative to pictures. However, at this low statistical threshold false positives need to be excluded. The semantic decision paradigm was therefore repeated, within subject, in two different scanners (1.5 and 3 T). Both scanners consistently localised left OT activation for words relative to fixation and pictures relative to words, but there were no consistent effects for words relative to pictures. Finally, in a third experiment, we minimised the voxel size (1.5 x 1.5 x 1.5 mm(3)) and demonstrated a striking concordance between the voxels activated for words and pictures, irrespective of task (naming vs. one-back) or script (English vs. Hebrew). In summary, although we detected differential activation for words relative to pictures, these effects: (i) do not withstand statistical rigour; (ii) do not replicate within or between subjects; and (iii) are observed in voxels that also respond to pictures of objects. Our findings have implications for the role of left OT activation during reading. More generally, they show that studies using low statistical thresholds in single subject analyses should correct the statistical threshold for the number of comparisons made or replicate effects within subject. (c) 2007 Wiley-Liss, Inc.

  18. False-Positive Results in a Recombinant Severe Acute Respiratory Syndrome-Associated Coronavirus (SARS-CoV) Nucleocapsid Enzyme-Linked Immunosorbent Assay Due to HCoV-OC43 and HCoV-229E Rectified by Western Blotting with Recombinant SARS-CoV Spike Polypeptide

    OpenAIRE

    Woo, Patrick C. Y.; Lau, Susanna K. P.; Wong, Beatrice H. L.; Chan, Kwok-Hung; Hui, Wai-Ting; Kwan, Grace S. W.; Peiris, J. S. Malik; Couch, Robert B.; Yuen, Kwok-Yung

    2004-01-01

    Using paired serum samples obtained from patients with illness associated with increases in anti-human coronavirus OC43 (HCoV-OC43) or anti-HCoV-229E antibodies, we examined the possibility of false-positive results detected in a recombinant severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) nucleocapsid protein immunoglobulin G enzyme-linked immunosorbent assay (ELISA). Three of the 21 and 1 of the 7 convalescent-phase serum samples from persons with increases in anti...

  19. Interval Breast Cancer Rates and Histopathologic Tumor Characteristics after False-Positive Findings at Mammography in a Population-based Screening Program.

    Science.gov (United States)

    Hofvind, Solveig; Sagstad, Silje; Sebuødegård, Sofie; Chen, Ying; Roman, Marta; Lee, Christoph I

    2018-04-01

    Purpose To compare rates and tumor characteristics of interval breast cancers (IBCs) detected after a negative versus false-positive screening among women participating in the Norwegian Breast Cancer Screening Program. Materials and Methods The Cancer Registry Regulation approved this retrospective study. Information about 423 445 women aged 49-71 years who underwent 789 481 full-field digital mammographic screening examinations during 2004-2012 was extracted from the Cancer Registry of Norway. Rates and odds ratios of IBC among women with a negative (the reference group) versus a false-positive screening were estimated by using logistic regression models adjusted for age at diagnosis and county of residence. Results A total of 1302 IBCs were diagnosed after 789 481 screening examinations, of which 7.0% (91 of 1302) were detected among women with a false-positive screening as the most recent breast imaging examination before detection. By using negative screening as the reference, adjusted odds ratios of IBCs were 3.3 (95% confidence interval [CI]: 2.6, 4.2) and 2.8 (95% CI: 1.8, 4.4) for women with a false-positive screening without and with needle biopsy, respectively. Women with a previous negative screening had a significantly lower proportion of tumors that were 10 mm or less (14.3% [150 of 1049] vs 50.0% [seven of 14], respectively; P false-positive screening with benign biopsy. A retrospective review of the screening mammographic examinations identified 42.9% (39 of 91) of the false-positive cases to be the same lesion as the IBC. Conclusion By using a negative screening as the reference, a false-positive screening examination increased the risk of an IBC three-fold. The tumor characteristics of IBC after a negative screening were less favorable compared with those detected after a previous false-positive screening. © RSNA, 2017 Online supplemental material is available for this article.

  20. Biological false-positive venereal disease research laboratory test in cerebrospinal fluid in the diagnosis of neurosyphilis - a case-control study.

    Science.gov (United States)

    Zheng, S; Lin, R J; Chan, Y H; Ngan, C C L

    2018-03-01

    There is no clear consensus on the diagnosis of neurosyphilis. The Venereal Disease Research Laboratory (VDRL) test from cerebrospinal fluid (CSF) has traditionally been considered the gold standard for diagnosing neurosyphilis but is widely known to be insensitive. In this study, we compared the clinical and laboratory characteristics of true-positive VDRL-CSF cases with biological false-positive VDRL-CSF cases. We retrospectively identified cases of true and false-positive VDRL-CSF across a 3-year period received by the Immunology and Serology Laboratory, Singapore General Hospital. A biological false-positive VDRL-CSF is defined as a reactive VDRL-CSF with a non-reactive Treponema pallidum particle agglutination (TPPA)-CSF and/or negative Line Immuno Assay (LIA)-CSF IgG. A true-positive VDRL-CSF is a reactive VDRL-CSF with a concordant reactive TPPA-CSF and/or positive LIA-CSF IgG. During the study period, a total of 1254 specimens underwent VDRL-CSF examination. Amongst these, 60 specimens from 53 patients tested positive for VDRL-CSF. Of the 53 patients, 42 (79.2%) were true-positive cases and 11 (20.8%) were false-positive cases. In our setting, a positive non-treponemal serology has 97.6% sensitivity, 100% specificity, 100% positive predictive value and 91.7% negative predictive value for a true-positive VDRL-CSF based on our laboratory definition. HIV seropositivity was an independent predictor of a true-positive VDRL-CSF. Biological false-positive VDRL-CSF is common in a setting where patients are tested without first establishing a serological diagnosis of syphilis. Serological testing should be performed prior to CSF evaluation for neurosyphilis. © 2017 European Academy of Dermatology and Venereology.

  1. SU-G-BRB-03: Assessing the Sensitivity and False Positive Rate of the Integrated Quality Monitor (IQM) Large Area Ion Chamber to MLC Positioning Errors

    Energy Technology Data Exchange (ETDEWEB)

    Boehnke, E McKenzie; DeMarco, J; Steers, J; Fraass, B [Cedars-Sinai Medical Center, Los Angeles, CA (United States)

    2016-06-15

    Purpose: To examine both the IQM’s sensitivity and false positive rate to varying MLC errors. By balancing these two characteristics, an optimal tolerance value can be derived. Methods: An un-modified SBRT Liver IMRT plan containing 7 fields was randomly selected as a representative clinical case. The active MLC positions for all fields were perturbed randomly from a square distribution of varying width (±1mm to ±5mm). These unmodified and modified plans were measured multiple times each by the IQM (a large area ion chamber mounted to a TrueBeam linac head). Measurements were analyzed relative to the initial, unmodified measurement. IQM readings are analyzed as a function of control points. In order to examine sensitivity to errors along a field’s delivery, each measured field was divided into 5 groups of control points, and the maximum error in each group was recorded. Since the plans have known errors, we compared how well the IQM is able to differentiate between unmodified and error plans. ROC curves and logistic regression were used to analyze this, independent of thresholds. Results: A likelihood-ratio Chi-square test showed that the IQM could significantly predict whether a plan had MLC errors, with the exception of the beginning and ending control points. Upon further examination, we determined there was ramp-up occurring at the beginning of delivery. Once the linac AFC was tuned, the subsequent measurements (relative to a new baseline) showed significant (p <0.005) abilities to predict MLC errors. Using the area under the curve, we show the IQM’s ability to detect errors increases with increasing MLC error (Spearman’s Rho=0.8056, p<0.0001). The optimal IQM count thresholds from the ROC curves are ±3%, ±2%, and ±7% for the beginning, middle 3, and end segments, respectively. Conclusion: The IQM has proven to be able to detect not only MLC errors, but also differences in beam tuning (ramp-up). Partially supported by the Susan Scott Foundation.

  2. Malaria rapid diagnostic tests: Plasmodium falciparum infections with high parasite densities may generate false positive Plasmodium vivax pLDH lines

    Directory of Open Access Journals (Sweden)

    van Esbroeck Marjan

    2010-07-01

    Full Text Available Abstract Background Most malaria rapid diagnostic tests (RDTs detect Plasmodium falciparum and an antigen common to the four species. Plasmodium vivax-specific RDTs target P. vivax-specific parasite lactate dehydrogenase (Pv-pLDH. Previous observations of false positive Pv-pLDH test lines in P. falciparum samples incited to the present study, which assessed P. vivax-specific RDTs for the occurrence of false positive Pv-pLDH lines in P. falciparum samples. Methods Nine P. vivax-specific RDTs were tested with 85 P. falciparum samples of high (≥2% parasite density. Mixed P. falciparum/P. vivax infections were ruled out by real-time PCR. The RDTs included two-band (detecting Pv-pLDH, three-band (detecting P. falciparum-antigen and Pv-pLDH and four-band RDTs (detecting P. falciparum, Pv-pLDH and pan-pLDH. Results False positive Pv-pLDH lines were observed in 6/9 RDTs (including two- three- and four-band RDTs. They occurred in the individual RDT brands at frequencies ranging from 8.2% to 29.1%. For 19/85 samples, at least two RDT brands generated a false positive Pv-pLDH line. Sixteen of 85 (18.8% false positive lines were of medium or strong line intensity. There was no significant relation between false positive results and parasite density or geographic origin of the samples. Conclusion False positive Pv-pLDH lines in P. falciparum samples with high parasite density occurred in 6/9 P. vivax-specific RDTs. This is of concern as P. falciparum and P. vivax are co-circulating in many regions. The diagnosis of life-threatening P. falciparum malaria may be missed (two-band Pv-pLDH RDT, or the patient may be treated incorrectly with primaquine (three- or four-band RDTs.

  3. Retroperitoneal Endometriosis: A Possible Cause of False Positive Finding at 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

    International Nuclear Information System (INIS)

    Maffione, Anna Margherita; Panzavolta, Riccardo; Lisato, Laura Camilla; Ballotta, Maria; D'Isanto, Mariangela Zanforlini; Rubello, Domenico

    2015-01-01

    Endometriosis is a frequent and clinically relevant problem in young women. Laparoscopy is still the gold standard for the diagnosis of endometriosis, but frequently both morphologic and functional imaging techniques are involved in the diagnostic course before achieving a conclusive diagnosis. We present a case of a patient affected by infiltrating retroperitoneal endometriosis falsely interpreted as a malignant mass by contrast-enhanced magnetic resonance imaging and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography

  4. False positive or negative results of shear-wave elastography in differentiating benign from malignant breast masses: analysis of clinical and ultrasonographic characteristics.

    Science.gov (United States)

    Kim, Mi Young; Choi, Nami; Yang, Jung-Hyun; Yoo, Young Bum; Park, Kyoung Sik

    2015-10-01

    Shear-wave elastography (SWE) has the potential to improve diagnostic performance of conventional ultrasound (US) in differentiating benign from malignant breast masses. To investigate false positive or negative results of SWE in differentiating benign from malignant breast masses and to analyze clinical and imaging characteristics of the masses with false SWE findings. From May to October 2013, 166 breast lesions of 164 consecutive women (mean age, 45.3 ± 10.1 years) who had been scheduled for biopsy were included. Conventional US and SWE were performed in all women before biopsy. Clinical, ultrasonographic morphologic features and SWE parameters (pattern classification and standard deviation [SD]) were recorded and compared with the histopathology results. Patient and lesion factors in the "true" and "false" groups were compared. Of the 166 masses, 118 (71.1%) were benign and 48 (28.9%) were malignant. False SWE features were more frequently observed in benign masses. False positive rates of benign masses and false negative rates of malignancy were 53% and 8.2%, respectively, using SWE pattern analysis and were 22.4% and 10.3%, respectively, using SD values. A lesion boundary of the masses on US (P = 0.039) and younger patient age (P = 0.047) were significantly associated with false SWE findings. These clinical and ultrasonographic features need to be carefully evaluated in performance and interpretation of SWE examinations. © The Foundation Acta Radiologica 2014.

  5. Small Intestinal Bacterial Overgrowth May Increase the Likelihood of Lactose and Sorbitol but not Fructose Intolerance False Positive Diagnosis.

    Science.gov (United States)

    Perets, Tsachi Tsadok; Hamouda, Dalal; Layfer, Olga; Ashorov, Olga; Boltin, Doron; Levy, Sigal; Niv, Yaron; Dickman, Ram

    2017-08-01

    Small intestinal bacterial overgrowth (SIBO) is defined as a bacterial count of more than 10 5 colony-forming units per milliliter in duodenal aspirate. It shares many symptoms with carbohydrate intolerance, which makes the clinical distinction of the disorders difficult. The aim of the study was to examine the relationship between a positive carbohydrate breath test and the presence of SIBO suggested by a positive lactulose hydrogen breath test. The electronic database of the gastroenterology laboratory of a tertiary medical center was searched for all patients clinically tested for SIBO in 2012-2013 for whom previous results for lactose, fructose, and/or sorbitol breath test were available. The correlation between positive findings for carbohydrate intolerance and for SIBO was statistically analyzed. The study group included 349 patients, 231 female and 118 male, of mean age 53±19 years. All had symptoms of abdominal bloating and gas. There was a statistically significant difference in rates of a positive breath test for lactose and sorbitol at ≤90 minutes between patients who were positive and negative for SIBO [χ 2 (1)=12.8, p <0.01 and χ 2 (1)=9.5, p <0.01 respectively]. Findings for fructose were not significant. There was no effect of age or gender. SIBO may represent an important reversible cause of carbohydrate intolerance. It may be especially prudent to exclude SIBO patients with an early peak (≤90 minutes) in H 2 excretion. © 2017 by the Association of Clinical Scientists, Inc.

  6. Immunoglobulins in Cerebrospinal Fluid

    DEFF Research Database (Denmark)

    Sellebjerg, Finn Thorup

    2015-01-01

    immunoglobulin synthesis. Intrathecally synthesised immunoglobulins are usually of restricted clonality, and electrophoresis-based methods can be used for detecting this in the form of oligoclonal bands. These methods depend on comparing paired CSF and blood samples. Qualitative analyses for the assessment......The assessment of intrathecally synthesised immunoglobulin is an important part of routine cerebrospinal fl uid (CSF) analysis. Immunoglobulins can be detected in normal CSF and are derived from plasma. The appearance of immunoglobulins in normal CSF is readily explained by size-dependent diffusion...

  7. Massive venlafaxine overdose resulted in a false positive Abbott AxSYM (R) urine immunoassay for phencyclidine

    NARCIS (Netherlands)

    Bond, GR; Steele, PE; Uges, DRA

    2003-01-01

    Case report: A 13-yr-old girl overdosed on 48 x 150 mg venlafaxine (Effexor XR(R)). She was taking venlafaxine regularly for depression. Her only other medications included topical Benzamycin and pyridoxine 50 mg daily for acne. The Abbott AxSYM(R) assay was positive only for phencyclidine, but

  8. Recall Latencies, Confidence, and Output Positions of True and False Memories: Implications for Recall and Metamemory Theories

    Science.gov (United States)

    Jou, Jerwen

    2008-01-01

    Recall latency, recall accuracy rate, and recall confidence were examined in free recall as a function of recall output serial position using a modified Deese-Roediger-McDermott paradigm to test a strength-based theory against the dual-retrieval process theory of recall output sequence. The strength theory predicts the item output sequence to be…

  9. Combination of RNA- and exome-sequencing efficiently eliminates false-positive somatic point mutations and indels – exemplified by cases of CN-AML

    DEFF Research Database (Denmark)

    Herborg, Laura Laine; Hansen, Marcus Celik; Roug, Anne Stidsholt

    Thorough annotation as a means of detecting highly relevant mutations, and aberrated genes, is becoming more feasible as the evidence of biological pathways underlying malignant transformation compiles. However, there is a continuous risk of misinterpretating both true and false positive observat......Thorough annotation as a means of detecting highly relevant mutations, and aberrated genes, is becoming more feasible as the evidence of biological pathways underlying malignant transformation compiles. However, there is a continuous risk of misinterpretating both true and false positive...... in the workflow, not only provides information on malignant expression profiles excluded here, but importantly help to capture the, often very few somatic mutations of myeloid leukaemia....

  10. Radiodine administration under suppression of TSH for identification of false positive receptions in patients with thyroid differentiated carcinoma (TDC): utility of the potassium perchlorate

    International Nuclear Information System (INIS)

    Santangelo, L.A.; Pitoia, F.; Sanz, C.; Niepomniszcze, H.; El Tamer, Elias

    2004-01-01

    The total body scan, after a dose of 131 I correlated with the measurement of stimulated Tg, constitute the principal pillars in follow-up of patients with TDC (thyroid differentiated carcinoma). A bibliographical search revealed more than 70 situations that can cause false total body scans positive. The examination is essential to avoid unnecessary treatment with radioiodine. The object is to evaluate the effectiveness of the radioiodine administration under hormonal therapy thyroid suppressive (THST) to eliminate the possibility of a false total body scan positive in five patients with TDC with stimulated Tg <1ng/ml

  11. [Tropheryma whipplei and Whipple disease: false positive PCR detections of Tropheryma whipplei in diagnostic samples are rare].

    Science.gov (United States)

    Le Scanff, J; Gaultier, J B; Durand, D Vital; Durieu, I; Celard, M; Benito, Y; Vandenesch, F; Rousset, H

    2008-11-01

    PCR can be used to detect T. whipplei (Tw) in samples from variable tissue types and body fluids. We report clinical, evolutive characteristics and final diagnosis in patients with positive Tw PCR assay. Retrospective study of Tw PCR realized since 10years in a microbiology laboratory. Twenty-five Tw PCR assays were positive among 200 realized. Diagnosis was not confirmed in six cases. One patient was missing for follow up. Eighteen patients presented with Whipple's disease. Among these 18 patients, 14 had a classic Whipple's disease, three patients presented an endocarditis and one patient isolated neurological manifestations. Ten patients presented fever, seven a weight loss and 12 joint involvement. Four patients presented cutaneous manifestations, only six had gastrointestinal symptoms. Neurological involvement was reported in five cases, pulmonary symptoms in four cases, cardiac involvement in six cases and ocular signs in two cases. Anemia was reported in four patients and elevated levels of acute-phase reactants in 14 cases. Positive predictive value of Tw PCR for Whipple's disease diagnosis was 75%. Thirteen patients had a good evolution with antibiotics. Three patients presented recurrence and two cases with cardiovascular involvement died. Whipple's disease is rare but often mentioned in internist experience. The diagnosis should be every time confirmed. Tw PCR assay is an important diagnostic tool but is not sufficient to establish the diagnosis and must be interpreted with histopathology and immunohistochemical testing results.

  12. Strategies to Increase Cancer Detection: Review of True-Positive and False-Negative Results at Digital Breast Tomosynthesis Screening

    Science.gov (United States)

    Weinstein, Susan P.; McDonald, Elizabeth S.; Conant, Emily F.

    2016-01-01

    Digital breast tomosynthesis (DBT) represents a valuable addition to breast cancer screening by decreasing recall rates while increasing cancer detection rates. The increased accuracy achieved with DBT is due to the quasi–three-dimensional format of the reconstructed images and the ability to “scroll through” breast tissue in the reconstructed images, thereby reducing the effect of tissue superimposition found with conventional planar digital mammography. The margins of both benign and malignant lesions are more conspicuous at DBT, which allows improved lesion characterization, increased reader confidence, and improved screening outcomes. However, even with the improvements in accuracy achieved with DBT, there remain differences in breast cancer conspicuity by mammographic view. Early data suggest that breast cancers may be more conspicuous on craniocaudal (CC) views than on mediolateral oblique (MLO) views. While some very laterally located breast cancers may be visualized on only the MLO view, the increased conspicuity of cancers on the CC view compared with the MLO view suggests that DBT screening should be performed with two-view imaging. Even with the improved conspicuity of lesions at DBT, there may still be false-negative studies. Subtle lesions seen on only one view may be discounted, and dense and/or complex tissue patterns may make some cancers occult or extremely difficult to detect. Therefore, radiologists should be cognizant of both perceptual and cognitive errors to avoid potential pitfalls in lesion detection and characterization. ©RSNA, 2016 Online supplemental material is available for this article. PMID:27715711

  13. ABIOTIC O2 LEVELS ON PLANETS AROUND F, G, K, AND M STARS: POSSIBLE FALSE POSITIVES FOR LIFE?

    International Nuclear Information System (INIS)

    Harman, C. E.; Kasting, J. F.; Schwieterman, E. W.; Schottelkotte, J. C.

    2015-01-01

    In the search for life on Earth-like planets around other stars, the first (and likely only) information will come from the spectroscopic characterization of the planet's atmosphere. Of the countless number of chemical species terrestrial life produces, only a few have the distinct spectral features and the necessary atmospheric abundance to be detectable. The easiest of these species to observe in Earth's atmosphere is O 2 (and its photochemical byproduct, O 3 ). However, O 2 can also be produced abiotically by photolysis of CO 2 , followed by recombination of O atoms with each other. CO is produced in stoichiometric proportions. Whether O 2 and CO can accumulate to appreciable concentrations depends on the ratio of far-ultraviolet (FUV) to near-ultraviolet (NUV) radiation coming from the planet's parent star and on what happens to these gases when they dissolve in a planet's oceans. Using a one-dimensional photochemical model, we demonstrate that O 2 derived from CO 2 photolysis should not accumulate to measurable concentrations on planets around F- and G-type stars. K-star, and especially M-star planets, however, may build up O 2 because of the low NUV flux from their parent stars, in agreement with some previous studies. On such planets, a “false positive” for life is possible if recombination of dissolved CO and O 2 in the oceans is slow and if other O 2 sinks (e.g., reduced volcanic gases or dissolved ferrous iron) are small. O 3 , on the other hand, could be detectable at UV wavelengths (λ < 300 nm) for a much broader range of boundary conditions and stellar types

  14. ABIOTIC O{sub 2} LEVELS ON PLANETS AROUND F, G, K, AND M STARS: POSSIBLE FALSE POSITIVES FOR LIFE?

    Energy Technology Data Exchange (ETDEWEB)

    Harman, C. E.; Kasting, J. F. [Geosciences Department, Pennsylvania State University, University Park, PA 16802 (United States); Schwieterman, E. W. [NASA Astrobiology Institute—Virtual Planetary Laboratory (United States); Schottelkotte, J. C., E-mail: ceharmanjr@psu.edu [Astronomy Department, Pennsylvania State University, University Park, PA 16802 (United States)

    2015-10-20

    In the search for life on Earth-like planets around other stars, the first (and likely only) information will come from the spectroscopic characterization of the planet's atmosphere. Of the countless number of chemical species terrestrial life produces, only a few have the distinct spectral features and the necessary atmospheric abundance to be detectable. The easiest of these species to observe in Earth's atmosphere is O{sub 2} (and its photochemical byproduct, O{sub 3}). However, O{sub 2} can also be produced abiotically by photolysis of CO{sub 2}, followed by recombination of O atoms with each other. CO is produced in stoichiometric proportions. Whether O{sub 2} and CO can accumulate to appreciable concentrations depends on the ratio of far-ultraviolet (FUV) to near-ultraviolet (NUV) radiation coming from the planet's parent star and on what happens to these gases when they dissolve in a planet's oceans. Using a one-dimensional photochemical model, we demonstrate that O{sub 2} derived from CO{sub 2} photolysis should not accumulate to measurable concentrations on planets around F- and G-type stars. K-star, and especially M-star planets, however, may build up O{sub 2} because of the low NUV flux from their parent stars, in agreement with some previous studies. On such planets, a “false positive” for life is possible if recombination of dissolved CO and O{sub 2} in the oceans is slow and if other O{sub 2} sinks (e.g., reduced volcanic gases or dissolved ferrous iron) are small. O{sub 3}, on the other hand, could be detectable at UV wavelengths (λ < 300 nm) for a much broader range of boundary conditions and stellar types.

  15. Myositis ossificans: a false positive of malignancy in PET - CT F.D.G. and in osseous scintigraphy with HMDP 99Tc

    International Nuclear Information System (INIS)

    Hassler, S.; Bourahla, K.

    2010-01-01

    Myositis ossificans is a difficult differential diagnosis and a false positive for malignancy in both 99m Tc H.M.D.P. (hydroxy-methylene diphosphonate) scintigraphy and in exploration PET-F.D.G. This hypothesis should be mentioned in case of young patients, despite the unusual scintigraphic appearance in a benign process. (N.C.)

  16. Likelihood of early detection of breast cancer in relation to false-positive risk in life-time mammographic screening: population-based cohort study.

    Science.gov (United States)

    Otten, J D M; Fracheboud, J; den Heeten, G J; Otto, S J; Holland, R; de Koning, H J; Broeders, M J M; Verbeek, A L M

    2013-10-01

    Women require balanced, high-quality information when making an informed decision on screening benefits and harms before attending biennial mammographic screening. The cumulative risk of a false-positive recall and/or (small) screen-detected or interval cancer over 13 consecutive screening examinations for women aged 50 from the start of screening were estimated using data from the Nijmegen programme, the Netherlands. Women who underwent 13 successive screens in the period 1975-1976 had a 5.3% cumulative chance of a screen-detected cancer, with a 4.2% risk of at least one false-positive recall. The risk of being diagnosed with interval cancer was 3.7%. Two decades later, these estimates were 6.9%, 7.3% and 2.9%, respectively. The chance of detection of a small, favourable invasive breast cancer, anticipating a normal life-expectancy, rose from 2.3% to 3.7%. Extrapolation to digital screening mammography indicates that the proportion of false-positive results will rise to 16%. Dutch women about to participate in the screening programme can be reassured that the chance of false-positive recall in the Netherlands is relatively low. A new screening policy and improved mammography have increased the detection of an early screening carcinoma and lowering the risk of interval carcinoma.

  17. Placing symptoms in context: the role of contextual criteria in reducing false positives in Diagnostic and Statistical Manual of Mental Disorders diagnoses.

    Science.gov (United States)

    Wakefield, Jerome C; First, Michael B

    2012-02-01

    The Diagnostic and Statistical Manual of Mental Disorders (DSM) definition of mental disorder requires that symptoms be caused by a dysfunction in the individual; when dysfunction is absent, symptoms represent normal-range distress or eccentricity and, if diagnosed as a mental disorder, are false positives. We hypothesized that because of psychiatry's lack of direct laboratory tests to distinguish dysfunction from normal-range distress, the context in which symptoms occur (eg, lack of imminent danger in a panic attack) is often essential to determining whether symptoms are caused by a dysfunction. If this is right, then the DSM diagnostic criteria should include many contextual criteria added to symptom syndromes to prevent dysfunction false positives. Despite their potential importance, such contextual criteria have not been previously reviewed. We, thus, systematically reviewed DSM categories to establish the extent of such uses of contextual criteria and created a typology of such uses. Of 111 sampled categories, 68 (61%) used context to prevent dysfunction false positives. Contextual criteria fell into 7 types: (1) exclusion of specific false-positive scenarios; (2) requiring that patients experience preconditions for normal responses (eg, requiring that individuals experience adequate sexual stimulation before being diagnosed with sexual dysfunctions); (3) requiring that symptoms be disproportionate relative to circumstances; (4) for childhood disorders, requiring that symptoms be developmentally inappropriate; (5) requiring that symptoms occur in multiple contexts; (6) requiring a substantial discrepancy between beliefs and reality; and (7) a residual category. Most DSM categories include contextual criteria to eliminate false-positive diagnoses and increase validity of descriptive criteria. Future revisions should systematically evaluate each category's need for contextual criteria. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. [EXPERIENCE OF STUDY AND POSSIBLE WAYS OF ELIMINATION OF FALSE POSITIVE AND FALSE NEGATIVE RESULTS DURING EXECUTION OF POLYMERASE CHAIN REACTION ON AN EXAMPLE OF JUNIN VIRUS RNA DETECTION].

    Science.gov (United States)

    Sizikova, T E; Lebedev, V N; Pantyukhov, V B; Borisevich, S V; Merkulov, V A

    2015-01-01

    Experience of study and possible ways of elimination of false positive and false negative results during execution of polymerase chain reaction on an example of Junin virus RNA detection. MATERIALSS AND METHODS: Junin virus--causative agent of Argentine hemorrhagic fever (AHF) strain XJpR37/5787 was obtained from the State collection of pathogenicity group I causative agents of the 48th Central Research Institute. Reagent kit for detection of Junin virus RNA by RT-PCR was developed in the Institute and consists of 4 sets: for isolation of RNA, execution of reverse-transcription reaction, execution of PCR and electrophoretic detection of PCR products. RT-PCR was carried out by a standard technique. Continuous cell cultures of African green monkey Vero B, GMK-AH-1(D) were obtained from the museum of cell culture department of the Centre. An experimental study of the effect of various factors of impact on the sample under investigation ("thawing-freezing", presence of formaldehyde, heparin) on the obtaining of false negative results during Junin virus RNA detection by using RT-PCR was studied. Addition of 0.01% heparin to the samples was shown to completely inhibit PCR. Addition of 0.05% formaldehyde significantly reduces sensitivity of the method. A possibility of reduction of analysis timeframe from 15 to 5 days was shown during detection of the causative agent in samples with low concentration of the latter by growing the samples and subsequent analysis of the material obtained by using RT-PCR. During detection of causative agent by using RT-PCR false negative results could appear in the presence of formaldehyde and heparin in the sample. A possibility of elimination of false negative PCR results due to concentration of the causative agent in the sample under investigation at a level below sensitivity threshold was shown on the example of Junin virus RNA detection by using growing of the pathogen in appropriate accumulation system with subsequent analysis of the

  19. An analysis of true- and false-positive results of vocal fold uptake in positron emission tomography-computed tomography imaging.

    Science.gov (United States)

    Seymour, N; Burkill, G; Harries, M

    2018-03-01

    Positron emission tomography-computed tomography with fluorine-18 fluorodeoxy-D-glucose has a major role in the investigation of head and neck cancers. Fluorine-18 fluorodeoxy-D-glucose is not a tumour-specific tracer and can also accumulate in benign pathology. Therefore, positron emission tomography-computed tomography scan interpretation difficulties are common in the head and neck, which can produce false-positive results. This study aimed to investigate patients detected as having abnormal vocal fold uptake on fluorine-18 fluorodeoxy-D-glucose positron emission tomography-computed tomography. Positron emission tomography-computed tomography scans were identified over a 15-month period where reports contained evidence of unilateral vocal fold uptake or vocal fold pathology. Patients' notes and laryngoscopy results were analysed. Forty-six patients were identified as having abnormal vocal fold uptake on positron emission tomography-computed tomography. Twenty-three patients underwent positron emission tomography-computed tomography and flexible laryngoscopy: 61 per cent of patients had true-positive positron emission tomography-computed tomography scans and 39 per cent had false-positive scan results. Most patients referred to ENT for abnormal findings on positron emission tomography-computed tomography scans had true-positive findings. Asymmetrical fluorine-18 fluorodeoxy-D-glucose uptake should raise suspicion of vocal fold pathology, accepting a false-positive rate of approximately 40 per cent.

  20. High prevalence of human anti-bovine IgG antibodies as the major cause of false positive reactions in two-site immunoassays based on monoclonal antibodies

    DEFF Research Database (Denmark)

    Andersen, Ditte C; Koch, Claus; Jensen, Charlotte H

    2004-01-01

    were purified by protein G affinity chromatography from culture supernatant containing 10% (v/v) fetal calf serum (FCS). Human anti-animal IgG (bovine, mouse, horse, and swine) antibodies and human anti-bovine serum albumin antibodies were measured using an ELISA design, with direct bridging...... of the solid phase and biotinylated antigens. The false positive reactions were abolished by addition of 1% (v/v) bovine serum to the dilution buffer (DB). Human anti-bovine IgG antibodies (HABIA) were detected in 99 out of 104 sera from blood donors (50 females; 54 males). HABIA levels in male sera (n = 54......) were positively correlated to the false positive signals in the PP14 ELISA (r = 0.923; p detected in the donor sera, but levels and frequencies were lower compared to that of HABIA. Furthermore, HABIA were...

  1. Efficient detection of human circulating tumor cells without significant production of false-positive cells by a novel conditionally replicating adenovirus

    Directory of Open Access Journals (Sweden)

    Fuminori Sakurai

    2016-01-01

    Full Text Available Circulating tumor cells (CTCs are promising biomarkers in several cancers, and thus methods and apparatuses for their detection and quantification in the blood have been actively pursued. A novel CTC detection system using a green fluorescence protein (GFP–expressing conditionally replicating adenovirus (Ad (rAd-GFP was recently developed; however, there is concern about the production of false-positive cells (GFP-positive normal blood cells when using rAd-GFP, particularly at high titers. In addition, CTCs lacking or expressing low levels of coxsackievirus–adenovirus receptor (CAR cannot be detected by rAd-GFP, because rAd-GFP is constructed based on Ad serotype 5, which recognizes CAR. In order to suppress the production of false-positive cells, sequences perfectly complementary to blood cell–specific microRNA, miR-142-3p, were incorporated into the 3′-untranslated region of the E1B and GFP genes. In addition, the fiber protein was replaced with that of Ad serotype 35, which recognizes human CD46, creating rAdF35-142T-GFP. rAdF35-142T-GFP efficiently labeled not only CAR-positive tumor cells but also CAR-negative tumor cells with GFP. The numbers of false-positive cells were dramatically lower for rAdF35-142T-GFP than for rAd-GFP. CTCs in the blood of cancer patients were detected by rAdF35-142T-GFP with a large reduction in false-positive cells.

  2. Uptake of 131-I in maxillary bones mimicking salivary glands. False- positive images in patients with differentiated thyroid carcinoma (DTC )

    International Nuclear Information System (INIS)

    Degrossi, Osvaldo J.; Degrossi, E.B.; Levi de Cabrejas, Mariana

    2008-01-01

    with the intensity of the administered activity of radioiodine, the previous condition of dental integrity and in patients living in the interior of our country in zones of 'bad' water containing tracers of arsenic and fluorine. In 13 patients submitted to intense treatment of dental problems posterior WBS showed a decrease of the positive maxilla areas or they were not found. The presence of metastasis in the active maxilla area was in all cases negative. Our observations confirm that radioiodine is deposited in maxillary bone in relation of dental lesions and that this 131-I move in a very slow place. This mechanism of fixation has to be determined. We fully recommended taking into account the existence of dental illness or incomplete dental treatments when the administration of higher activities than 3.7 GBq (150 mCi). (author) [es

  3. The Lifetime Economic Burden of Inaccurate HER2 Testing: Estimating the Costs of False-Positive and False-Negative HER2 Test Results in US Patients with Early-Stage Breast Cancer.

    Science.gov (United States)

    Garrison, Louis P; Babigumira, Joseph B; Masaquel, Anthony; Wang, Bruce C M; Lalla, Deepa; Brammer, Melissa

    2015-06-01

    Patients with breast cancer whose tumors test positive for human epidermal growth factor receptor 2 (HER2) are treated with HER2-targeted therapies such as trastuzumab, but limitations with HER2 testing may lead to false-positive (FP) or false-negative (FN) results. To develop a US-level model to estimate the effect of tumor misclassification on health care costs and patient quality-adjusted life-years (QALYs). Decision analysis was used to estimate the number of patients with early-stage breast cancer (EBC) whose HER2 status was misclassified in 2012. FP results were assumed to generate unnecessary trastuzumab costs and unnecessary cases of trastuzumab-related cardiotoxicity. FN results were assumed to save money on trastuzumab, but with a loss of QALYs and greater risk of disease recurrence and its associated costs. QALYs were valued at $100,000 under a net monetary benefit approach. Among 226,870 women diagnosed with EBC in 2012, 3.12% (n = 7,070) and 2.18% (n = 4,955) were estimated to have had FP and FN test results, respectively. Approximately 8400 QALYs (discounted, lifetime) were lost among women not receiving trastuzumab because of FN results. The estimated incremental per-patient lifetime burden of FP or FN results was $58,900 and $116,000, respectively. The implied incremental losses to society were $417 million and $575 million, respectively. HER2 tests result in misclassification and nonoptimal treatment of approximately 12,025 US patients with EBC annually. The total economic societal loss of nearly $1 billion suggests that improvements in HER2 testing accuracy are needed and that further clinical and economic studies are warranted. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  4. Evaluation of false positive responses by mass spectrometry and ion mobility spectrometry for the detection of trace explosives in complex samples

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, C.L., E-mail: clcrawf@sandia.gov; Hill, H.H.

    2013-09-17

    Graphical abstract: -- Highlights: •First study to use (−)SESI-IM-TOFMS to analyze complex mixtures of personal care products. •The study demonstrated, by identifying mobility and mass interferents with explosive signatures, which, if used separately, neither IMS nor MS alone would prevent every false positive for explosives when detected in the presence of a complex sample matrix. •Ingredients in common household cleaning products were shown to either enhance or suppress the ionization of explosives in a SESI-IM-TOFMS analysis. •Mobility separation provided real-time separation of ion species that indicated overlapping isotope peak patterns -- Abstract: Secondary electrospray ionization-ion mobility-time of flight mass spectrometry (SESI-IM-TOFMS) was used to evaluate common household products and food ingredients for any mass or mobility responses that produced false positives for explosives. These products contained ingredients which shared the same mass and mobility drift time ranges as the analyte ions for common explosives. The results of this study showed that the vast array of compounds in these products can cause either mass or mobility false positive responses. This work also found that two ingredients caused either enhanced or reduced ionization of the target analytes. Another result showed that an IMS can provide real-time separation of ion species that impede accurate mass identifications due to overlapping isotope peak patterns. The final result of this study showed that, when mass and mobility values were used to identify an ion, no false responses were found for the target explosives. The wider implication of these results is that the possibility exists for even greater occurrences of false responses from complex mixtures found in common products. Neither IMS nor MS alone can provide 100% assurance from false responses. IMS, due to its low cost, ease of operation, rugged reliability, high sensitivity and tunable selectivity, will remain

  5. False positive of the scintigraphy with octreoscan: a diagnosis of elimination; Faux positif de la scintigraphie a l'octreoscan: un diagnostic d'elimination

    Energy Technology Data Exchange (ETDEWEB)

    Charrier, N.; Brenot-Rossi, I.; Chuto, G.; Giovannini, M.; Delpero, J.R. [Institut Paoli-Calmettes, Marseille, (France)

    2009-05-15

    The imaging of receptors with somatostatin analogs by the pentetreotide-indium 111 (octreoscan) allows the detection of endocrine tumors essentially according to the density of S.S.T.2 receptors at the tumor level. The sensitivity of octreoscan for the detection of intestine endocrine tumors is included between 80 and 100% in the different studies. The clinical case presented here enlightens a case of false positive.We concluded to a physiological elimination of pentetreotide-indium 111 with intra pancreatic biliary stasis (perhaps a dysfunction of sphincter of ampulla of bile duct) and to the lack of tumor centre. It is here a diagnosis of elimination, supported by the different results of examination. all normal. This case of false positive induced expensive and traumatic explorations for the patient. (N.C.)

  6. False-positive positron emission tomography appearance with 18F-fluorodeoxyglucose after definitive radiotherapy for cancer of the mobile tongue.

    Science.gov (United States)

    Ariji, Y; Fuwa, N; Kodaira, T; Tachibana, H; Nakamura, T; Satoh, Y; Ariji, E

    2009-01-01

    (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is an effective tool for evaluating the results of radiotherapy. However, some false-positive appearances caused by physiological or pathological accumulation are reported. We report on three patients who showed a high accumulation of FDG in the lingual muscles but had no recurrent tumour after definitive radiotherapy for the mobile tongue. All patients had squamous cell carcinoma of the tongue and received interstitial radiotherapy with small sources. High uptake was seen in the lingual muscles without recurrence or inflammation, based on physical and MR examinations. This false-positive appearance is thought to relate to ill-balanced high activity of the lingual muscles after definitive radiotherapy.

  7. Unusual False Positive Radioiodine Uptake on 131I Whole Body Scintigraphy in Three Unrelated Organs with Different Pathologies in Patients of Differentiated Thyroid Carcinoma: A Case Series

    International Nuclear Information System (INIS)

    Ranade, Rohit; Pawar, Shwetal; Mahajan, Abhishek; Basu, Sandip

    2016-01-01

    Three cases with unusual false positive radioiodine uptake in three different organs and pathologies (infective old fibrotic lesion in the lung, simple liver cyst, and benign breast lesion) on iodine-131 ( 131 I) whole body scintigraphy. Clinicoradiological correlation was undertaken in all three cases and the pathologies were ascertained. In all the three cases, single-photon emission computerized tomography-computed tomography (SPECT-CT) and ancillary imaging modalities were employed and were helpful in arriving at the final diagnosis

  8. Image findings of a false positive radioactive iodine-131 uptake mimicking metastasis in pulmonary aspergillosis identified on single photon emission computed tomography-computed tomography

    Directory of Open Access Journals (Sweden)

    Kamaleshwaran Koramadai Karuppusamy

    2015-01-01

    Full Text Available High doses of iodine-131 are commonly used in patients with differentiated thyroid cancer after total or subtotal thyroidectomy, in order to ablate the remaining cancer or normal thyroid tissue. Multiple different false-positive scans can occur in the absence of residual thyroid tissue or metastases. The authors present a case of abnormal uptake of radioactive iodine in the aspergilloma, potentially masquerading as pulmonary metastases.

  9. Clinical evaluation of false-positive scintigraphic lesions of the left lobe in portal hypertension. Comparison with portographic findings of the pars umbilicus of the portal vein

    Energy Technology Data Exchange (ETDEWEB)

    Takayasu, Kenichi; Moriyama, Noriyuki; Suzuki, Masao; Yamada, Tatsuya [National Cancer Center, Tokyo (Japan). Hospital; Fukutake, Toshio

    1982-09-01

    sup(99m)Tc-phytate liver scan and percutaneous transhepatic portography (PTP) were performed in 33 patients with portal hypertension due to various hepatic diseases. A defect or space occupying lesion in the left lobe on the scan in these patients was analysed with reference to portographic changes of the pars umbilicus of the left portal vein and the following results were obtained. 1) A false-positive defect on the scintigram was found in 6 (18.2%) of 33 patients, and portal vein pressure (PVP) was above 200 mmH/sub 2/O in all 6 which constituted 21.4% of 28 with PVP above 200 mmH/sub 2/O. 2) In five out of 6 patients with false-positive scan findings, the pars umbilicus was dilated to more than 25 x 15 mm in size, and it was huge and tortuous in 3 of them. 3) The mean PVP in the group with a false-positive scan tended to be higher than that in patients with no abnormalities on the scintigram. It was concluded that in reading of liver scintigrams in patients with portal hypertension, a dilated pars umbilicus and huge para-umbilical vein should be considered.

  10. Proportion of false-positive lesions at interim and end-of-treatment FDG-PET in lymphoma as determined by histology: Systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Hugo J.A., E-mail: h.j.a.adams@gmail.com; Kwee, Thomas C.

    2016-11-15

    Purpose: To systematically review and meta-analyze the proportion of false-positive lesions at interim and end-of-treatment {sup 18}F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in lymphoma using biopsy as reference standard. Materials and methods: Medline was searched for original studies. Methodological quality of included studies was evaluated, and results were meta-analytically summarized using random effects (in case of interstudy heterogeneity [I{sup 2} ≤ 50%]) or fixed effects (in case of no interstudy heterogeneity [I{sup 2} > 50%]). Results: Eleven studies, comprising 139 patients who underwent biopsy of an FDG-avid lesion during or after completion of antilymphoma treatment, were included. Overall methodological quality was moderate. The proportion of false-positive results among all biopsied FDG-avid lesions at PET performed during of after completion of treatment ranged between 7.7% and 90.5% (the vast majority was due to inflammatory changes), with a weighted summary proportion (random effects, I{sup 2} = 75.7%) of 55.7% (95% confidence interval [CI]: 32.6–76.6%). There were no available studies on interim FDG-PET in Hodgkin lymphoma. The pooled summary false-positive proportions were 83.0% (95% CI: 72.0%–90.2%) for interim FDG-PET in non-Hodgkin lymphoma (fixed effects, I{sup 2} = 27.7%), 23.1% (95% CI: 4.7%–64.5%) for end-of-treatment FDG-PET in Hodgkin lymphoma (random effects; I{sup 2} = 67.1%), and 31.5% (95% CI: 3.9%–83.9%) for end-of-treatment FDG-PET in non-Hodgkin lymphoma (random effects, I{sup 2} = 68.3%). Conclusion: Both interim and end-of-treatment FDG-PET scans in patients with lymphoma suffer from a very high number of false-positive FDG-avid lesions. This finding, in combination with the previously reported high number of false-negative FGD-PET scans for residual disease detection, suggests that the role of interim and end-of-treatment FDG-PET should be reconsidered.

  11. Next-generation sequencing indicates false-positive MRD results and better predicts prognosis after SCT in patients with childhood ALL.

    Science.gov (United States)

    Kotrova, M; van der Velden, V H J; van Dongen, J J M; Formankova, R; Sedlacek, P; Brüggemann, M; Zuna, J; Stary, J; Trka, J; Fronkova, E

    2017-07-01

    Minimal residual disease (MRD) monitoring via quantitative PCR (qPCR) detection of Ag receptor gene rearrangements has been the most sensitive method for predicting prognosis and making post-transplant treatment decisions for patients with ALL. Despite the broad clinical usefulness and standardization of this method, we and others have repeatedly reported the possibility of false-positive MRD results caused by massive B-lymphocyte regeneration after stem cell transplantation (SCT). Next-generation sequencing (NGS) enables precise and sensitive detection of multiple Ag receptor rearrangements, thus providing a more specific readout compared to qPCR. We investigated two cohorts of children with ALL who underwent SCT (30 patients and 228 samples). The first cohort consisted of 17 patients who remained in long-term CR after SCT despite having low MRD positivity (SCT monitoring using qPCR. Only one of 27 qPCR-positive samples was confirmed to be positive by NGS. Conversely, 10 of 15 samples with low qPCR-detected MRD positivity from 13 patients who subsequently relapsed were also confirmed to be positive by NGS (P=0.002). These data show that NGS has a better specificity in post-SCT ALL management and indicate that treatment interventions aimed at reverting impending relapse should not be based on qPCR only.

  12. An audit to investigate the impact of false positive breast screening results and diagnostic work-up on re-engagement with subsequent routine screening

    International Nuclear Information System (INIS)

    Nightingale, Julie M.; Borgen, Rita; Porter-Bennett, Lisa; Szczepura, Katy

    2015-01-01

    Introduction: Women attending breast screening may have suspicious mammographic findings that are subsequently found at assessment clinic to be normal (false positive, FP). A false positive diagnosis is not harmless, with short and long term negative psychosocial consequences reported. Women are at increased relative risk of breast cancer therefore their attendance at subsequent screening is essential. Aims: To assess the impact of FP breast screening diagnosis and diagnostic work-up on re-attendance rates across four consecutive screening rounds at a typical breast screening centre. Method: Diagnostic interventions and screening re-attendance rates at one prior and two consecutive rounds were analysed for women receiving an FP diagnosis between 2004 and 2006. Results: 397 women (5.57%) were referred for further assessment, including 228 (57.43%) false positives. 34 eligible women failed to re-attend routine screening (+3 years), with 17 failing to re-attend subsequently (+6 years). 70.6% (24/34) of non-attenders had attended at least two screening rounds prior to FP assessment. 75% of FP women had an imaging-only assessment with 17.5% (30/171) failing to re-attend, and 25% received a biopsy, with 7% (4/57) failing to re-attend subsequently. Conclusion: This study is unique as it follows FP women through four consecutive screening rounds. FP non-attendance rates were considerably lower compared to the general screening population, with diagnostic work-up having limited influence. FP non-attendance may appear insignificant in comparison to total screened population, but these women are at greater risk of subsequent cancer so should be actively encouraged to re-engage with the screening programme

  13. Massive training artificial neural network (MTANN) for reduction of false positives in computerized detection of lung nodules in low-dose computed tomography

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Armato, Samuel G. III; Li, Feng; Sone, Shusuke; Doi, Kunio

    2003-01-01

    In this study, we investigated a pattern-recognition technique based on an artificial neural network (ANN), which is called a massive training artificial neural network (MTANN), for reduction of false positives in computerized detection of lung nodules in low-dose computed tomography (CT) images. The MTANN consists of a modified multilayer ANN, which is capable of operating on image data directly. The MTANN is trained by use of a large number of subregions extracted from input images together with the teacher images containing the distribution for the 'likelihood of being a nodule'. The output image is obtained by scanning an input image with the MTANN. The distinction between a nodule and a non-nodule is made by use of a score which is defined from the output image of the trained MTANN. In order to eliminate various types of non-nodules, we extended the capability of a single MTANN, and developed a multiple MTANN (Multi-MTANN). The Multi-MTANN consists of plural MTANNs that are arranged in parallel. Each MTANN is trained by using the same nodules, but with a different type of non-nodule. Each MTANN acts as an expert for a specific type of non-nodule, e.g., five different MTANNs were trained to distinguish nodules from various-sized vessels; four other MTANNs were applied to eliminate some other opacities. The outputs of the MTANNs were combined by using the logical AND operation such that each of the trained MTANNs eliminated none of the nodules, but removed the specific type of non-nodule with which the MTANN was trained, and thus removed various types of non-nodules. The Multi-MTANN consisting of nine MTANNs was trained with 10 typical nodules and 10 non-nodules representing each of nine different non-nodule types (90 training non-nodules overall) in a training set. The trained Multi-MTANN was applied to the reduction of false positives reported by our current computerized scheme for lung nodule detection based on a database of 63 low-dose CT scans (1765

  14. 21 CFR 866.5520 - Immunoglobulin G (Fab fragment specific) immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunoglobulin G (Fab fragment specific... Test Systems § 866.5520 Immunoglobulin G (Fab fragment specific) immunological test system. (a) Identification. An immunoglobulin G (Fab fragment specific) immunological test system is a device that consists...

  15. 21 CFR 866.5540 - Immunoglobulin G (Fd fragment specific) immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunoglobulin G (Fd fragment specific... Test Systems § 866.5540 Immunoglobulin G (Fd fragment specific) immunological test system. (a) Identification. An immunoglobulin G (Fd fragment specific) immunological test system is a device that consists of...

  16. 21 CFR 866.5530 - Immunoglobulin G (Fc fragment specific) immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunoglobulin G (Fc fragment specific... Test Systems § 866.5530 Immunoglobulin G (Fc fragment specific) immunological test system. (a) Identification. An immunoglobulin G (Fc fragment specific) immunological test system is a device that consists of...

  17. A Nested PCR Assay to Avoid False Positive Detection of the Microsporidian Enterocytozoon hepatopenaei (EHP) in Environmental Samples in Shrimp Farms

    Science.gov (United States)

    Jaroenlak, Pattana; Sanguanrut, Piyachat; Williams, Bryony A. P.; Stentiford, Grant D.; Flegel, Timothy W.; Sritunyalucksana, Kallaya

    2016-01-01

    Hepatopancreatic microsporidiosis (HPM) caused by Enterocytozoon hepatopenaei (EHP) is an important disease of cultivated shrimp. Heavy infections may lead to retarded growth and unprofitable harvests. Existing PCR detection methods target the EHP small subunit ribosomal RNA (SSU rRNA) gene (SSU-PCR). However, we discovered that they can give false positive test results due to cross reactivity of the SSU-PCR primers with DNA from closely related microsporidia that infect other aquatic organisms. This is problematic for investigating and monitoring EHP infection pathways. To overcome this problem, a sensitive and specific nested PCR method was developed for detection of the spore wall protein (SWP) gene of EHP (SWP-PCR). The new SWP-PCR method did not produce false positive results from closely related microsporidia. The first PCR step of the SWP-PCR method was 100 times (104 plasmid copies per reaction vial) more sensitive than that of the existing SSU-PCR method (106 copies) but sensitivity was equal for both in the nested step (10 copies). Since the hepatopancreas of cultivated shrimp is not currently known to be infected with microsporidia other than EHP, the SSU-PCR methods are still valid for analyzing hepatopancreatic samples despite the lower sensitivity than the SWP-PCR method. However, due to its greater specificity and sensitivity, we recommend that the SWP-PCR method be used to screen for EHP in feces, feed and environmental samples for potential EHP carriers. PMID:27832178

  18. Significance of FDG-PET in Identification of Diseases of the Appendix – Based on Experience of Two Cases Falsely Positive for FDG Accumulation

    Directory of Open Access Journals (Sweden)

    Shimpei Ogawa

    2009-04-01

    Full Text Available A discussion of the significance of F-fluorodeoxyglucose positron emission tomography (FDG-PET in the identification of diseases of the appendix is presented based on two cases falsely positive for FDG accumulation. Both cases were palpable for a tumor in the lower right abdominal region and a prominently enlarged appendix was depicted by CT. Although the patients underwent ileocecal resection based on a strong suspicion of appendiceal cancer rather than appendicitis since abnormal accumulation exhibiting maximum standard uptake values (SUVs of 7.27 and 17.11, respectively, was observed at the same site in FDG-PET examination and since there no malignant findings observed histologically, the patients were diagnosed with appendicitis. Although FDG specifically accumulates not only in malignant tumors, but also in diseases such as acute or chronic inflammation, abscesses and lymphadenitis, and identification based on SUVs has been reported to be used as a method of identification, the two cases reported here were both false-positive cases exhibiting high maximum SUVs. At the present time, although the significance of FDG-PET in the identification of diseases of the appendix is somewhat low and there are limitations on its application, various research is currently being conducted with the aim of improving diagnostic accuracy, and it is hoped that additional studies will be conducted in the future.

  19. A Nested PCR Assay to Avoid False Positive Detection of the Microsporidian Enterocytozoon hepatopenaei (EHP) in Environmental Samples in Shrimp Farms.

    Science.gov (United States)

    Jaroenlak, Pattana; Sanguanrut, Piyachat; Williams, Bryony A P; Stentiford, Grant D; Flegel, Timothy W; Sritunyalucksana, Kallaya; Itsathitphaisarn, Ornchuma

    2016-01-01

    Hepatopancreatic microsporidiosis (HPM) caused by Enterocytozoon hepatopenaei (EHP) is an important disease of cultivated shrimp. Heavy infections may lead to retarded growth and unprofitable harvests. Existing PCR detection methods target the EHP small subunit ribosomal RNA (SSU rRNA) gene (SSU-PCR). However, we discovered that they can give false positive test results due to cross reactivity of the SSU-PCR primers with DNA from closely related microsporidia that infect other aquatic organisms. This is problematic for investigating and monitoring EHP infection pathways. To overcome this problem, a sensitive and specific nested PCR method was developed for detection of the spore wall protein (SWP) gene of EHP (SWP-PCR). The new SWP-PCR method did not produce false positive results from closely related microsporidia. The first PCR step of the SWP-PCR method was 100 times (104 plasmid copies per reaction vial) more sensitive than that of the existing SSU-PCR method (106 copies) but sensitivity was equal for both in the nested step (10 copies). Since the hepatopancreas of cultivated shrimp is not currently known to be infected with microsporidia other than EHP, the SSU-PCR methods are still valid for analyzing hepatopancreatic samples despite the lower sensitivity than the SWP-PCR method. However, due to its greater specificity and sensitivity, we recommend that the SWP-PCR method be used to screen for EHP in feces, feed and environmental samples for potential EHP carriers.

  20. Usefulness of pulse-wave doppler tissue sampling and dobutamine stress echocardiography for identification of false positive inferior wall defects in SPECT

    International Nuclear Information System (INIS)

    Altinmakas, S.; Dagdeviren, B.; Turkmen, M.; Gursurer, M.; Say, B.; Tezel, T.; Ersek, B.

    2000-01-01

    False positive inferior wall perfusion defects restrict the accuracy of SPECT in diagnosis of coronary artery disease (CAD). Pulse-Wave Tissue Doppler (PWTD) has been recently proposed to assess regional wall motion velocities. The objectives of this study were to evaluate the presence of CAD by using PWTD during dobutamine stress echocardiography (DSE) in patients with an inferior perfusion defect detected by SPECT and compare PWTD parameters of normal cases with patients who had inferior perfusion defect and CAD. Sixty-five patients (mean age 58±8 years, 30 men) with a normal LV systolic function at rest according to echocardiographic evaluation with an inferior ischemia determined by SPECT and a control group (CG) of 34 normal cases (mean age 56±7 years, 16 men) were included in this study. All patients underwent a standard DSE (up to 40 μg/kg/min with additional atropine during sub-maximum heart rate responses). Pulse-wave Doppler tissue sampling of inferior wall was performed in the apical 2-chamber view at rest and stress. The coronary angiography was performed within 24 hours. The results were evaluated for the prediction of significant right coronary artery (RCA) and/or left circumflex coronary artery (CX) with narrowing (≥50% diameter stenosis, assessed by quantitative coronary angiography). It was observed that the peak stress mean E/A ratio was lower in patients with CAD when compared to patients without CAD (0.78±0.2 versus 1.29±0.11 p<0.0001). Also the peak stress E/A ratio of normal cases was significantly higher than patients who had CAD (1.19±0.3 versus 0.78±0.2 p<0.0001). When the cut off point for the E/A ratio was determined as 1, the sensitivity and specificity of dobutamine stress PWTD E/A were 89% and 86%, respectively. The peak stress E/A ratio was higher than 1 in all patients with a false positive perfusion defect. Systolic S velocity increase during DSE was significantly lower in patients with CAD (54%±17 versus 99%±24 p=0

  1. The Relations Between False Positive and Negative Screens and Smoking Cessation and Relapse in the National Lung Screening Trial: Implications for Public Health.

    Science.gov (United States)

    Clark, Melissa A; Gorelick, Jeremy J; Sicks, JoRean D; Park, Elyse R; Graham, Amanda L; Abrams, David B; Gareen, Ilana F

    2016-01-01

    Lung screening is an opportunity for smoking cessation and relapse prevention, but smoking behaviors may differ across screening results. Changes in smoking were evaluated among 18 840 current and former smokers aged 55-74 scheduled to receive three annual lung screenings. Participants were randomized to low-dose computed tomography or single-view chest radiography in the American College of Radiology/National Lung Screening Trial. Outcome measures included point and sustained (6-month) abstinence and motivation to quit among smokers; and relapse among smokers who quit during follow-up, recent quitters (quit < 6 months), and long-term former smokers (quit ≥ 6 months). During five years of follow-up, annual point prevalence quit rates ranged from 11.6%-13.4%; 48% of current smokers reported a quit attempt and 7% of long-term former smokers relapsed. Any false positive screening result was associated with subsequent increased point (multivariable hazard ratio HR = 1.23, 95% CI = 1.13, 1.35) and sustained (HR = 1.28, 95% CI = 1.15, 1.43) abstinence among smokers. Recent quitters with ≥1 false positive screen were less likely to relapse (HR = 0.72, 95% CI = 0.54, 0.96). Screening result was not associated with relapse among long-term former smokers or among baseline smokers who quit during follow-up. A false positive screen was associated with increased smoking cessation and less relapse among recent quitters. Consistently negative screens were not associated with greater relapse among long-term former smokers. Given the Affordable Care Act requires most health plans to cover smoking cessation and lung screening, the impact and cost-effectiveness of lung screening could be further enhanced with the addition of smoking cessation interventions. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Detection of Yersinia enterocolitica serotype O:9 in the faeces of cattle with false positive reactions in serological tests for brucellosis in Ireland.

    Science.gov (United States)

    O'Grady, Don; Kenny, Kevin; Power, Seamus; Egan, John; Ryan, Fergus

    2016-10-01

    Intestinal infection by Yersinia enterocolitica serotype O:9 (YeO9) in cattle has been linked to false positive serological reactivity (FPSR) in diagnostic tests for brucellosis. Although eradicated in Ireland, brucellosis monitoring still identifies seropositive animals, usually one or two (termed singletons) per herd, which are classed as FPSR. To investigate a link between FPSR and YeO9, faeces and blood were collected from singleton FPSR cattle, and from companion animals, in eight selected herds with more than one FPSR animal, for YeO9 culture and Brucella serology. YeO9 was isolated from 76/474 (16%) FPSR singletons in 309 herds, but not from any of 621 animals in 122 control non-FPSR herds. In the FPSR herds 52/187 (27.8%) animals were culture positive, and 17% of the isolates were from seronegative animals. Seropositive animals were more likely to have a rising antibody titre when culture positive. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. False assumptions.

    Science.gov (United States)

    Swaminathan, M

    1997-01-01

    Indian women do not have to be told the benefits of breast feeding or "rescued from the clutches of wicked multinational companies" by international agencies. There is no proof that breast feeding has declined in India; in fact, a 1987 survey revealed that 98% of Indian women breast feed. Efforts to promote breast feeding among the middle classes rely on such initiatives as the "baby friendly" hospital where breast feeding is promoted immediately after birth. This ignores the 76% of Indian women who give birth at home. Blaming this unproved decline in breast feeding on multinational companies distracts attention from more far-reaching and intractable effects of social change. While the Infant Milk Substitutes Act is helpful, it also deflects attention from more pressing issues. Another false assumption is that Indian women are abandoning breast feeding to comply with the demands of employment, but research indicates that most women give up employment for breast feeding, despite the economic cost to their families. Women also seek work in the informal sector to secure the flexibility to meet their child care responsibilities. Instead of being concerned about "teaching" women what they already know about the benefits of breast feeding, efforts should be made to remove the constraints women face as a result of their multiple roles and to empower them with the support of families, governmental policies and legislation, employers, health professionals, and the media.

  4. False-positive 18F-fluorodeoxyglucose positron emission tomography/computed tomography in a patient with metallic implants following chondrosarcoma resection.

    Science.gov (United States)

    Zhou, P U; Tang, Jinliang; Zhang, Dong; Li, Guanghui

    2016-05-01

    Positron emission tomography (PET) with fluorine-18-labeled fluorodeoxyglucose ( 18 F-FDG) has been used for the staging and evaluation of recurrence in cancer patients. We herein report a false-positive result of 18 F-FDG PET/computed tomography (CT) scan in a patient following chondrosarcoma resection and metallic implanting. A 35-year-old male patient with chondrosarcoma of the left iliac bone underwent radical resection, metal brace implanting and radiotherapy. A high uptake of 18 F-FDG was observed in the metallic implants and adjacent tissue during PET/CT scanning in the 5th year of follow-up. Tissue biopsy and follow-up examination identified no tumor recurrence or infection at these sites, suggesting that the results of 18 F-FDG PET/CT must be interpreted with caution in cancer patients with metallic implants.

  5. The Dutch Brucella abortus monitoring programme for cattle: the impact of false-positive serological reactions and comparison of serological tests.

    Science.gov (United States)

    Emmerzaal, A; de Wit, J J; Dijkstra, Th; Bakker, D; van Zijderveld, F G

    2002-02-01

    The Dutch national Brucella abortus eradication programme for cattle started in 1959. Sporadic cases occurred yearly until 1995; the last infected herd was culled in 1996. In August 1999 the Netherlands was declared officially free of bovine brucellosis by the European Union. Before 1999, the programme to monitor the official Brucella-free status of bovine herds was primarily based on periodical testing of dairy herds with the milk ring test (MRT) and serological testing of all animals older than 1 year of age from non-dairy herds, using the micro-agglutination test (MAT) as screening test. In addition, serum samples of cattle that aborted were tested with the MAT. The high number of false positive reactions in both tests and the serum agglutination test (SAT) and complement fixation test (CFT) used for confirmation seemed to result in unnecessary blockade of herds, subsequent testing and slaughter of animals. For this reason, a validation study was performed in which three indirect enzyme-linked immunosorbent assays (ELISAs), the CFT and the SAT were compared using a panel of sera from brucellosis-free cattle, sera from experimentally infected cattle, and sera from cattle experimentally infected with bacteria which are known to induce cross-reactive antibodies (Pasteurella, Salmonella, Yersinia, and Escherichia). Moreover, four ELISAs and the MRT were compared using a panel of 1000 bulk milk samples from Brucella-free herds and 12 milk samples from Brucella abortus- infected cattle. It is concluded that the ELISA obtained from ID-Lelystad is the most suitable test to monitor the brucelosis free status of herds because it gives rise to fewer false-positive reactions than the SAT.

  6. Upward creep of the heart: A frequent source of false-positive reversible defects during thallium-201 stress-redistribution SPECT

    International Nuclear Information System (INIS)

    Friedman, J.; Van Train, K.; Maddahi, J.; Rozanski, A.; Prigent, F.; Bietendorf, J.; Waxman, A.; Berman, D.S.

    1989-01-01

    A new cause of artifactual 201 Tl defects on single photon emission computed tomography (SPECT) termed upward creep of the heart is described. In 102 consecutive patients undergoing 201 Tl SPECT, 30 (29%) demonstrated upward creep defined by an upward movement of the heart of greater than or equal to 2 pixels during acquisition. In 45 consecutive patients with a less than 5% likelihood of coronary artery disease, 17 (38%) had upward creep. Of these nine had reversible 201 Tl defects localized to the inferior and basal inferoseptal walls, while none of the 28 without upward creep had defects. The 17 low likelihood patients with upward creep had longer exercise duration and higher peak heart rate than those without upward creep. In five additional low likelihood patients with upward creep in whom imaging was immediately repeated, the upward creep pattern disappeared on the repeated images. After we changed our test protocol to begin imaging 15 min postexercise, only five (14%) of 36 low likelihood patients tested demonstrated upward creep. Upward creep is probably related to a transient increase in mean total lung volume early following exhaustive exercise, resulting in a mean lower position of the diaphragm (and thus the heart) at the beginning of imaging. The frequency of this source of false-positive 201 Tl studies can be reduced by delaying SPECT acquisition until 15 min postexercise

  7. Avian metapneumovirus RT-nested-PCR: a novel false positive reducing inactivated control virus with potential applications to other RNA viruses and real time methods.

    Science.gov (United States)

    Falchieri, Marco; Brown, Paul A; Catelli, Elena; Naylor, Clive J

    2012-12-01

    Using reverse genetics, an avian metapneumovirus (AMPV) was modified for use as a positive control for validating all stages of a popular established RT-nested PCR, used in the detection of the two major AMPV subtypes (A and B). Resultant amplicons were of increased size and clearly distinguishable from those arising from unmodified virus, thus allowing false positive bands, due to control virus contamination of test samples, to be identified readily. Absorption of the control virus onto filter paper and subsequent microwave irradiation removed all infectivity while its function as an efficient RT-nested-PCR template was unaffected. Identical amplicons were produced after storage for one year. The modified virus is likely to have application as an internal standard as well as in real time methods. Additions to AMPV of RNA from other RNA viruses, including hazardous examples such HIV and influenza, are likely to yield similar safe RT-PCR controls. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. False-negative type-specific glycoprotein G antibody responses in STI clinic patients with recurrent HSV-1 or HSV-2 DNA positive genital herpes, The Netherlands.

    Science.gov (United States)

    van Rooijen, Martijn S; Roest, Wim; Hansen, Gino; Kwa, David; de Vries, Henry J C

    2016-06-01

    Herpes simplex virus (HSV) type-discriminating antibody tests (glycoprotein G (gG) directed) are used to identify naïve persons and differentiate acute infections from recurrences. We studied test characteristics of three commercially available antibody tests in patients with recurrent (established by viral PCR tests) herpes simplex virus type 1 (HSV-1) or herpes simplex virus type 2 (HSV-2) genital herpes episodes. Serum samples (at minimum 3 months after t=0) were examined for the presence of gG-1-specific or gG-2-specific antibodies using the HerpeSelect 1 and 2 Immunoblot IgG, the HerpeSelect 1 and 2 enzyme linked immunoassays IgG and the LIAISON HSV-1 and HSV-2 IgG indirect chemiluminescence immunoassays. The immunoblot was HSV-1 positive in 70.6% (95% CI 44.0% to 89.7%), the LIAISON in 88.2% (95% CI 63.5% to 98.5%) and the ELISA in 82.4% (95% CI 56.6% to 96.2%) of the 17 patients with a recurrent HSV-1 episode. From 33 patients with a recurrent HSV-2 episode, the immunoblot was HSV-2 positive in 84.8% (95% CI 68.1% to 94.9%), the LIAISON in 69.7% (95% CI 51.3% to 84.4%) and the ELISA in 84.8% (95% CI 68.1% to 94.9%). Among 15/17 (88.2%; 95% CI 63.5% to 98.5%) patients with HSV-1 and 30/33 (90.1%; 95% CI 75.7% to 98.1%) patients with HSV-2, HSV-1 or HSV-2 antibodies, respectively, were detected in at least one of the three antibody tests. Commercial type-specific gG HSV-1 or HSV-2 antibody assays were false negative in 12-30% of patients with recurrent HSV-1 or HSV-2 DNA positive genital lesions. The clinical and epidemiological use of type-specific HSV serology can be hampered by false-negative results, especially if based on a single test. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  9. Massive-training artificial neural network (MTANN) for reduction of false positives in computer-aided detection of polyps: Suppression of rectal tubes

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Yoshida, Hiroyuki; Naeppi, Janne; Dachman, Abraham H.

    2006-01-01

    One of the limitations of the current computer-aided detection (CAD) of polyps in CT colonography (CTC) is a relatively large number of false-positive (FP) detections. Rectal tubes (RTs) are one of the typical sources of FPs because a portion of a RT, especially a portion of a bulbous tip, often exhibits a cap-like shape that closely mimics the appearance of a small polyp. Radiologists can easily recognize and dismiss RT-induced FPs; thus, they may lose their confidence in CAD as an effective tool if the CAD scheme generates such ''obvious'' FPs due to RTs consistently. In addition, RT-induced FPs may distract radiologists from less common true positives in the rectum. Therefore, removal RT-induced FPs as well as other types of FPs is desirable while maintaining a high sensitivity in the detection of polyps. We developed a three-dimensional (3D) massive-training artificial neural network (MTANN) for distinction between polyps and RTs in 3D CTC volumetric data. The 3D MTANN is a supervised volume-processing technique which is trained with input CTC volumes and the corresponding ''teaching'' volumes. The teaching volume for a polyp contains a 3D Gaussian distribution, and that for a RT contains zeros for enhancement of polyps and suppression of RTs, respectively. For distinction between polyps and nonpolyps including RTs, a 3D scoring method based on a 3D Gaussian weighting function is applied to the output of the trained 3D MTANN. Our database consisted of CTC examinations of 73 patients, scanned in both supine and prone positions (146 CTC data sets in total), with optical colonoscopy as a reference standard for the presence of polyps. Fifteen patients had 28 polyps, 15 of which were 5-9 mm and 13 were 10-25 mm in size. These CTC cases were subjected to our previously reported CAD scheme that included centerline-based segmentation of the colon, shape-based detection of polyps, and reduction of FPs by use of a Bayesian neural network based on geometric and texture

  10. Immunoglobulins for preventing hepatitis A

    DEFF Research Database (Denmark)

    Liu, Jian Ping; Nikolova, Dimitrinka; Fei, Yutong

    2009-01-01

    Hepatitis A (infectious hepatitis) is a common epidemic disease. Immunoglobulins for passive immunisation are used as prevention.......Hepatitis A (infectious hepatitis) is a common epidemic disease. Immunoglobulins for passive immunisation are used as prevention....

  11. Toward the breast screening balance sheet: cumulative risk of false positives for annual versus biennial mammograms commencing at age 40 or 50.

    Science.gov (United States)

    Winch, Caleb J; Sherman, Kerry A; Boyages, John

    2015-01-01

    This study aimed to: (1) Estimate cumulative risk of recall from breast screening where no cancer is detected (a harm) in Australia; (2) Compare women screened annually versus biennially, commencing age 40 versus 50; and (3) Compare with international findings. At the no-cost metropolitan program studied, women attended biennial screening, but were offered annual screening if regarded at elevated risk for breast cancer. The cumulative risk of at least one recall was estimated using discrete-time survival analysis. Cancer detection statistics were computed. In total, 801,636 mammograms were undertaken in 231,824 women. Over 10 years, cumulative risk of recall was 13.3 % (95 % CI 12.7-13.8) for those screened biennially, and 19.9 % (CI 16.6-23.2) for those screened annually from age 50-51. Cumulative risk of complex false positive involving a biopsy was 3.1 % (CI 2.9-3.4) and 5.0 % (CI 3.4-6.6), respectively. From age 40-41, the risk of recall was 15.1 % (CI 14.3-16.0) and 22.5 % (CI 17.9-27.1) for biennial and annual screening, respectively. Corresponding rates of complex false positive were 3.3 % (CI 2.9-3.8) and 6.3 % (CI 3.4-9.1). Over 10 mammograms, invasive cancer was detected in 3.4 % (CI 3.3-3.5) and ductal carcinoma in situ in 0.7 % (CI 0.6-0.7) of women, with a non-significant trend toward a larger proportion of Tis and T1N0 cancers in women screened annually (74.5 %) versus biennially (70.1 %), χ (2) = 2.77, p = 0.10. Cancer detection was comparable to international findings. Recall risk was equal to European estimates for women screening from 50 and lower for screening from 40. Recall risk was half of United States' rates across start age and rescreening interval categories. Future benefit/harm balance sheets may be useful for communicating these findings to women.

  12. Raising Awareness of False Positive Newborn Screening Results Arising from Pivalate-Containing Creams and Antibiotics in Europe When Screening for Isovaleric Acidaemia

    Directory of Open Access Journals (Sweden)

    James R. Bonham

    2018-02-01

    Full Text Available While the early and asymptomatic recognition of treatable conditions offered by newborn screening confers clear health benefits for the affected child, the clinical referral of patients with screen positive results can cause significant harm for some families. The use of pivalate-containing antibiotics and more recently the inclusion of neopentanoate as a component within moisturising creams used as nipple balms by nursing mothers can result in a significant number of false positive results when screening for isovaleric acidaemia (IVA by measuring C5 acylcarnitine. A recent survey conducted within centres from nine countries indicated that this form of contamination had been or was a significant confounding factor in the detection of IVA in seven of the nine who responded. In three of these seven the prominent cause was believed to derive from the use of moisturising creams and in another three from antibiotics containing pivalate; one country reported that the cause was mixed. As a result, four of these seven centres routinely perform second tier testing to resolve C5 isobars when an initial C5 result is elevated, and a fifth is considering making this change within their national programme. The use of creams containing neopentanoate by nursing mothers and evolving patterns in the prescription of pivalate-containing antibiotics during pregnancy require those involved in the design and operation of newborn screening programmes used to detect IVA and the doctors who receive clinical referrals from these programmes to maintain an awareness of the potential impact of this form of interference on patient results.

  13. Small intestinal bacterial overgrowth as an uncommon cause of false positive lactose hydrogen breath test among patients with diarrhea-predominant irritable bowel syndrome in Asia.

    Science.gov (United States)

    Wang, Yilin; Xiong, Lishou; Gong, Xiaorong; Li, Weimin; Zhang, Xiangsong; Chen, Minhu

    2015-06-01

    It has been reported that small intestinal bacterial overgrowth (SIBO) may lead to false positive diagnoses of lactose malabsorption (LM) in irritable bowel syndrome patients. The aim of this study was to determine the influence of SIBO on lactose hydrogen breath test (HBT) results in these patients. Diarrhea-predominant irritable bowel syndrome patients with abnormal lactose HBTs ingested a test meal containing (99m) Tc and lactose. The location of the test meal and the breath levels of hydrogen were recorded simultaneously by scintigraphic scanning and lactose HBT, respectively. The increase in hydrogen concentration was not considered to be caused by SIBO if ≥ 10% of (99m) Tc accumulated in the cecal region at the time or before of abnormal lactose HBT. LM was present in 84% (31/37) of irritable bowel syndrome patients. Twenty of these patients agreed to measurement of oro-cecal transit time. Only three patients (15%) with abnormal lactose HBT might have had SIBO. The median oro-cecal transit time between LM and lactose intolerance patients were 75 min and 45 min, respectively (Z=2.545, P=0.011). Most of irritable bowel syndrome patients with an abnormal lactose HBT had LM. SIBO had little impact on the interpretation of lactose HBTs. The patients with lactose intolerance had faster small intestinal transit than LM patients. © 2014 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  14. False Positive 18F-FDG Uptake in Mediastinal Lymph Nodes Detected with Positron Emission Tomography in Breast Cancer: A Case Report

    Directory of Open Access Journals (Sweden)

    Gamze Uğurluer

    2013-01-01

    Full Text Available Breast cancer is the most frequently diagnosed cancer among females. It is accepted that lymph node involvement with metastatic tumor and the presence of distant metastasis are the most important prognostic factors. Accurate staging is important in determining prognosis and appropriate treatment. Positron emission tomography with computed tomography detects malignancies using 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG PET CT with high accuracy and they contribute to decisions regarding diagnosis, staging, recurrence, and treatment response. Here, we report a case of false positive metastatic mediastinal lymph nodes that were diagnosed by 18F-FDG PET CT in a 40-year-old breast cancer patient who had undergone preoperative evaluation. Right paratracheal, prevascular, aorticopulmonary, precarinal, subcarinal, hilar, and subhilar multiple conglomerated mediastinal lymph nodes were revealed in addition to left breast mass and axillary lymph nodes. Mediastinoscopy was performed with biopsy and pathology was reported as granulomatous lymphadenitis. In conclusion, any abnormal FDG accumulation in unusual lymph nodes must be evaluated carefully and confirmed histopathologically.

  15. Specificity and false positive rates of the Test of Memory Malingering, Rey 15-item Test, and Rey Word Recognition Test among forensic inpatients with intellectual disabilities.

    Science.gov (United States)

    Love, Christopher M; Glassmire, David M; Zanolini, Shanna Jordan; Wolf, Amanda

    2014-10-01

    This study evaluated the specificity and false positive (FP) rates of the Rey 15-Item Test (FIT), Word Recognition Test (WRT), and Test of Memory Malingering (TOMM) in a sample of 21 forensic inpatients with mild intellectual disability (ID). The FIT demonstrated an FP rate of 23.8% with the standard quantitative cutoff score. Certain qualitative error types on the FIT showed promise and had low FP rates. The WRT obtained an FP rate of 0.0% with previously reported cutoff scores. Finally, the TOMM demonstrated low FP rates of 4.8% and 0.0% on Trial 2 and the Retention Trial, respectively, when applying the standard cutoff score. FP rates are reported for a range of cutoff scores and compared with published research on individuals diagnosed with ID. Results indicated that although the quantitative variables on the FIT had unacceptably high FP rates, the TOMM and WRT had low FP rates, increasing the confidence clinicians can place in scores reflecting poor effort on these measures during ID evaluations. © The Author(s) 2014.

  16. Immunoglobulin and fatty acids

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising 0.1-10 w/w % immunoglobulin (Ig), 4-14 w/w % saturated fatty acids, 4-14 w/w % mono-unsaturated fatty acids and 0-5 w/w % poly-unsaturated fatty acids, wherein the weight percentages are based on the content of dry matter in the composition...

  17. Interpreting the results of the Semmes-Weinstein monofilament test: accounting for false-positive answers in the international consensus on the diabetic foot protocol by a new model.

    Science.gov (United States)

    Slater, Robert A; Koren, Shlomit; Ramot, Yoram; Buchs, Andreas; Rapoport, Micha J

    2014-01-01

    The Semmes-Weinstein monofilament is the most widely used test to diagnose the loss of protective sensation. The commonly used protocol of the International Consensus on the Diabetic Foot includes a 'sham' application that allows for false-positive answers. We sought to study the heretofore unexamined significance of false-positive answers. Forty-five patients with diabetes and a history of pedal ulceration (Group I) and 81 patients with diabetes but no history of ulceration (Group II) were studied. The three original sites of the International Consensus on the Diabetic Foot at the hallux, 1st metatarsal and 5th metatarsal areas were used. At each location, the test was performed three times: 2 actual and 1 "sham" applications. Scores were graded from 0 to 3 based upon correct responses. Determination of loss of protective sensation was performed with and without calculating a false-positive answer as a minus 1 score. False-positive responses were found in a significant percentage of patients with and without history of ulceration. Introducing false-positive results as minus 1 into the test outcome significantly increased the number of patients diagnosed with loss of protective sensation in both groups. False-positive answers can significantly affect Semmes-Weinstein monofilament test results and the diagnosis of LOPS. A model that accounts for false-positive answers is offered. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Contamination in the Kepler field. Identification of 685 KOIs as false positives via ephemeris matching based ON Q1-Q12 data

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, Jeffrey L.; Thompson, Susan E.; Burke, Christopher J.; Caldwell, Douglas A.; Jenkins, Jon M.; Mullally, Fergal R.; Rowe, Jason F. [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Bryson, Stephen T.; Haas, Michael R.; Howell, Steve B. [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Christiansen, Jessie L. [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena CA 91125 (United States); Kolodziejczak, Jeffery J., E-mail: jeffrey.l.coughlin@nasa.gov [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2014-05-01

    The Kepler mission has to date found almost 6000 planetary transit-like signals, utilizing three years of data for over 170,000 stars at extremely high photometric precision. Due to its design, contamination from eclipsing binaries, variable stars, and other transiting planets results in a significant number of these signals being false positives (FPs). This directly affects the determination of the occurrence rate of Earth-like planets in our Galaxy, as well as other planet population statistics. In order to detect as many of these FPs as possible, we perform ephemeris matching among all transiting planet, eclipsing binary, and variable star sources. We find that 685 Kepler Objects of Interest (KOIs)—12% of all those analyzed—are FPs as a result of contamination, due to 409 unique parent sources. Of these, 118 have not previously been identified by other methods. We estimate that ∼35% of KOIs are FPs due to contamination, when performing a first-order correction for observational bias. Comparing single-planet candidate KOIs to multi-planet candidate KOIs, we find an observed FP fraction due to contamination of 16% and 2.4% respectively, bolstering the existing evidence that multi-planet KOIs are significantly less likely to be FPs. We also analyze the parameter distributions of the ephemeris matches and derive a simple model for the most common type of contamination in the Kepler field. We find that the ephemeris matching technique is able to identify low signal-to-noise FPs that are difficult to identify with other vetting techniques. We expect FP KOIs to become more frequent when analyzing more quarters of Kepler data, and note that many of them will not be able to be identified based on Kepler data alone.

  19. Curved planar reformation and optimal path tracing (CROP) method for false positive reduction in computer-aided detection of pulmonary embolism in CTPA

    Science.gov (United States)

    Zhou, Chuan; Chan, Heang-Ping; Guo, Yanhui; Wei, Jun; Chughtai, Aamer; Hadjiiski, Lubomir M.; Sundaram, Baskaran; Patel, Smita; Kuriakose, Jean W.; Kazerooni, Ella A.

    2013-03-01

    The curved planar reformation (CPR) method re-samples the vascular structures along the vessel centerline to generate longitudinal cross-section views. The CPR technique has been commonly used in coronary CTA workstation to facilitate radiologists' visual assessment of coronary diseases, but has not yet been used for pulmonary vessel analysis in CTPA due to the complicated tree structures and the vast network of pulmonary vasculature. In this study, a new curved planar reformation and optimal path tracing (CROP) method was developed to facilitate feature extraction and false positive (FP) reduction and improve our PE detection system. PE candidates are first identified in the segmented pulmonary vessels at prescreening. Based on Dijkstra's algorithm, the optimal path (OP) is traced from the pulmonary trunk bifurcation point to each PE candidate. The traced vessel is then straightened and a reformatted volume is generated using CPR. Eleven new features that characterize the intensity, gradient, and topology are extracted from the PE candidate in the CPR volume and combined with the previously developed 9 features to form a new feature space for FP classification. With IRB approval, CTPA of 59 PE cases were retrospectively collected from our patient files (UM set) and 69 PE cases from the PIOPED II data set with access permission. 595 and 800 PEs were manually marked by experienced radiologists as reference standard for the UM and PIOPED set, respectively. At a test sensitivity of 80%, the average FP rate was improved from 18.9 to 11.9 FPs/case with the new method for the PIOPED set when the UM set was used for training. The FP rate was improved from 22.6 to 14.2 FPs/case for the UM set when the PIOPED set was used for training. The improvement in the free response receiver operating characteristic (FROC) curves was statistically significant (p<0.05) by JAFROC analysis, indicating that the new features extracted from the CROP method are useful for FP reduction.

  20. Caprine and ovine Greek dairy products: The official German method generates false-positive results due to κ-casein gene polymorphism.

    Science.gov (United States)

    Tsartsianidou, V; Triantafillidou, D; Karaiskou, N; Tarantili, P; Triantafillidis, G; Georgakis, E; Triantafyllidis, A

    2017-05-01

    Caseins are widely used for species identification of dairy products. Isoelectric focusing (IEF) of para-κ-casein peptide is used as the official German method for the differentiation between caprine (isoform A) and ovine (isoform B) dairy products, based on their different isoelectric points. The discrimination between Greek goat and ewe dairy products using IEF has, however, been shown to be problematic because of the existence of the ewe isoform in milk from Greek indigenous dairy goats. This could be due to nucleotide polymorphisms within the goat κ-casein gene of Greek indigenous breeds, which alter the isoelectric point of the para-κ-casein peptide and lead to false positive results. Previous DNA analysis of the goat κ-casein gene has shown high levels of polymorphism; however, no such information is available for Greek indigenous dairy goats. Therefore, 87 indigenous dairy goats were sequenced at exon IV of κ-casein gene. In total, 9 polymorphic sites were detected. Three nonsynonymous point mutations were identified, which change the isoelectric point of the goat para-κ-casein peptide so that it appears identical to that of the ewe peptide. Ten composite genotypes were reconstructed and 6 of them included the problematic point mutations. For the verification of genetic results, IEF was carried out. Both goat and ewe patterns appeared in the problematic genotypes. The frequency of these genotypes could be characterized as moderate (0.23) to high (0.60) within Greek indigenous breeds. However, this is not an issue restricted to Greece, as such genotypes have been detected in various non-Greek goat breeds. In conclusion, IEF based on the official German method is certainly inappropriate for ovine and caprine discrimination concerning Greek dairy goat products, and consequently a new method should be established. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Excluding Anti-cytomegalovirus Immunoglobulin M-Positive Cord Blood Units Has a Minimal Impact on the Korean Public Cord Blood Bank Inventory.

    Science.gov (United States)

    Shin, Sue; Roh, Eun Youn; Oh, Sohee; Song, Eun Young; Kim, Eui Chong; Yoon, Jong Hyun

    2017-01-24

    Cord blood units (CBUs) for transplantation should be free of communicable disease and must contain a specific amount of total nucleated cells and CD34+ cells. Although posttransplantation cytomegalovirus (CMV) infections are from latent infection in patients, ensuring CMV-free CBUs by performing CMV-specific IgM and nucleic acid amplification testing (NAT) is one of the mandatory procedures for the safety of CBUs. However, the exclusion policies (based on these test results) vary among nations and institutions. We tested 28,000 processed CBUs between May 2006 and June 2014. The cord blood leukocytes from CMV IgM-positive samples were then subjected to NAT. The total nucleated cell and CD34+ cell counts were measured for each CBU, and the results were compared to the CMV IgM and IgG results. The seroprevalence of CMV among pregnant women was 98.1% (18,459/18,818) for IgG and 1.7% (441/25,293) for IgM. The concentration and the total number of CD34+ cells were significantly higher in CBUs from IgM-negative mothers compared to those from IgM-positive mothers (72.4/μl vs. 57.2/μl, respectively, p < 0.0001; 1.45 × 106/unit vs. 1.15 × 106/unit, respectively, p < 0.0001). Among CBUs with positive CMV IgM in their mothers' plasma or cord blood plasma, only 0.58% of the samples (3/517) had a positive NAT. The number of excluded CBUs from inventory due to positive CMV IgM in the cord blood was 54 of 18,326 (0.3%). For inventory purposes, it is appropriate to remove CBUs with positive cord blood CMV IgM findings irrespective of the NAT status as well as positive maternal CMV IgM in South Korea.

  2. Automated detection of pulmonary nodules in PET/CT images: Ensemble false-positive reduction using a convolutional neural network technique

    Energy Technology Data Exchange (ETDEWEB)

    Teramoto, Atsushi, E-mail: teramoto@fujita-hu.ac.jp [Faculty of Radiological Technology, School of Health Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukake, Toyoake, Aichi 470-1192 (Japan); Fujita, Hiroshi [Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1194 (Japan); Yamamuro, Osamu; Tamaki, Tsuneo [East Nagoya Imaging Diagnosis Center, 3-4-26 Jiyugaoka, Chikusa-ku, Nagoya, Aichi 464-0044 (Japan)

    2016-06-15

    Purpose: Automated detection of solitary pulmonary nodules using positron emission tomography (PET) and computed tomography (CT) images shows good sensitivity; however, it is difficult to detect nodules in contact with normal organs, and additional efforts are needed so that the number of false positives (FPs) can be further reduced. In this paper, the authors propose an improved FP-reduction method for the detection of pulmonary nodules in PET/CT images by means of convolutional neural networks (CNNs). Methods: The overall scheme detects pulmonary nodules using both CT and PET images. In the CT images, a massive region is first detected using an active contour filter, which is a type of contrast enhancement filter that has a deformable kernel shape. Subsequently, high-uptake regions detected by the PET images are merged with the regions detected by the CT images. FP candidates are eliminated using an ensemble method; it consists of two feature extractions, one by shape/metabolic feature analysis and the other by a CNN, followed by a two-step classifier, one step being rule based and the other being based on support vector machines. Results: The authors evaluated the detection performance using 104 PET/CT images collected by a cancer-screening program. The sensitivity in detecting candidates at an initial stage was 97.2%, with 72.8 FPs/case. After performing the proposed FP-reduction method, the sensitivity of detection was 90.1%, with 4.9 FPs/case; the proposed method eliminated approximately half the FPs existing in the previous study. Conclusions: An improved FP-reduction scheme using CNN technique has been developed for the detection of pulmonary nodules in PET/CT images. The authors’ ensemble FP-reduction method eliminated 93% of the FPs; their proposed method using CNN technique eliminates approximately half the FPs existing in the previous study. These results indicate that their method may be useful in the computer-aided detection of pulmonary nodules

  3. Automated detection of pulmonary nodules in PET/CT images: Ensemble false-positive reduction using a convolutional neural network technique

    International Nuclear Information System (INIS)

    Teramoto, Atsushi; Fujita, Hiroshi; Yamamuro, Osamu; Tamaki, Tsuneo

    2016-01-01

    Purpose: Automated detection of solitary pulmonary nodules using positron emission tomography (PET) and computed tomography (CT) images shows good sensitivity; however, it is difficult to detect nodules in contact with normal organs, and additional efforts are needed so that the number of false positives (FPs) can be further reduced. In this paper, the authors propose an improved FP-reduction method for the detection of pulmonary nodules in PET/CT images by means of convolutional neural networks (CNNs). Methods: The overall scheme detects pulmonary nodules using both CT and PET images. In the CT images, a massive region is first detected using an active contour filter, which is a type of contrast enhancement filter that has a deformable kernel shape. Subsequently, high-uptake regions detected by the PET images are merged with the regions detected by the CT images. FP candidates are eliminated using an ensemble method; it consists of two feature extractions, one by shape/metabolic feature analysis and the other by a CNN, followed by a two-step classifier, one step being rule based and the other being based on support vector machines. Results: The authors evaluated the detection performance using 104 PET/CT images collected by a cancer-screening program. The sensitivity in detecting candidates at an initial stage was 97.2%, with 72.8 FPs/case. After performing the proposed FP-reduction method, the sensitivity of detection was 90.1%, with 4.9 FPs/case; the proposed method eliminated approximately half the FPs existing in the previous study. Conclusions: An improved FP-reduction scheme using CNN technique has been developed for the detection of pulmonary nodules in PET/CT images. The authors’ ensemble FP-reduction method eliminated 93% of the FPs; their proposed method using CNN technique eliminates approximately half the FPs existing in the previous study. These results indicate that their method may be useful in the computer-aided detection of pulmonary nodules

  4. Successful Desensitization of T cell Flow Cytometry Crossmatch Positive Renal Transplant Recipients Using Plasmapheresis and Super High-Dose Intravenous Immunoglobulin

    Directory of Open Access Journals (Sweden)

    Yoichi Kakuta, MD, PhD

    2018-01-01

    Full Text Available Background. High-dose IVIG (2 g/kg alone or low-dose IVIG (100 mg/kg in conjunction with plasma exchange is typically administered as a renal transplantation desensitization therapy. Herein, we monitored changes in T cell and B cell flow cytometry crossmatch (FCXM to assess the effects of short-term super high-dose IVIG (4 g/kg administration with plasmapheresis before living-donor renal transplantation. Methods. Seventeen patients, each showing positive T cell FCXM (median ratio, ≥ 1.4 after 2 rounds of double-filtration plasmapheresis, received 4-day regimens of IVIG (1 g/kg per day over 1-week periods. T cell and B cell FCXM determinations were obtained after every IVIG dose and again up to 4 weeks after initiating IVIG to ascertain negative conversion of T cell FCXM (median ratio < 1.4. The primary study endpoint was the percentage of patients achieving T cell FCXM-negative status after the 4-dose IVIG regimen. Results. Upon completion (4 g/kg total or discontinuation of IVIG administration, 8 (47.1% of 17 patients displayed negative T cell FCXM. Based on Kaplan-Meier estimates, the cumulative T cell FCXM-negative conversion rate 4 weeks after IVIG administration initiation was 60.3%. The T cell FCXM-negative conversion rates after cumulative doses of 1, 2, 3, and 4 g/kg IVIG were 29.4%, 35.3%, 56.3%, and 46.7%, respectively. Conclusions. Desensitization of donor-specific antibody-positive renal transplant recipients seems achievable in only a subset of recipients through IVIG dosing (1 g/kg × 4 within 1 week after double-filtration plasmapheresis. The T cell FCXM-negative conversion rate resulting from a cumulative IVIG dose of 3 g/kg or greater surpassed that attained via conventional single-dose IVIG (2 g/kg protocol. This short-term high-dose IVIG desensitization protocol may be an alternative to conventional protocols for recipients with donor-specific antibody.

  5. Output Position and Word Relatedness Effects in a DRM Paradigm: Support for a Dual-Retrieval Process Theory of Free Recall and False Memories

    Science.gov (United States)

    Barnhardt, T. M.; Choi, H.; Gerkens, D. R.; Smith, S. M.

    2006-01-01

    Five experiments investigated predictions--derived from a dual-retrieval process approach to free recall (Brainerd, C. J., Wright, R., Reyna, V. F., & Payne, D. G. (2002). Dual-retrieval processes in free and associative recall. Journal of Memory and Language, 46, 120-152.)--about false memories in a DRM-like paradigm. In all the experiments, the…

  6. Abiotic production of nitrous oxide by lightning. Implications for a false positive identification of life on Earth-Like Planets around quiescent M Dwarfs

    Science.gov (United States)

    Navarro, Karina F.; Navarro-Gonzalez, Rafael; McKay, Christopher P.

    _{2} dominated primitive Earth-like atmospheres. However, during the rise in atmospheric O _{2} at the start of the Proterozoic, the ocean became stratified (anoxic at the bottom and oxygenic at the surface). During this period, the emissions of N _{2}O were probably higher than today associated with a stronger microbial activity in the early anoxic ocean layer (Grenfell et al., 2011). Under this scenario, the predicted N _{2}O concentration would be about 3920 ppb, considering 10% the current atmospheric O _{2} concentrations, 100 times higher the current microbial N _{2}O flux, and a fainter Sun (94.3%) (Grenfell et al., 2011). This concentration would be still undetectable (Grenfell et al., 2011). A completely different scenario could be expected in Earth-like planets orbiting M dwarfs, which are the most abundant stars in the galaxy, representing about 75% of the total stellar population. M stars exhibit a large range in activity levels from very low levels of chromospheric and coronal activity, the so-called “quiescent” to high levels, the so-called “active" states. Photochemical models predict that the N _{2}O concentration would only increase to about 1,000 ppb for the current Earth orbiting an active M star, but surprisingly up to about 1,000 ppm for the current Earth orbiting a quiescent M star (Segura et al., 2005). Therefore, N _{2}O becomes a promising biomarker. Under this scenario it is important to constrain the abiotic sources of N _{2}O under different atmospheric conditions to avoid a false positive identification of life. Here we report an experimental study of the effects of lightning discharges on the nitrogen fixation rate during the evolution of the Earth’s early atmosphere from 10 to 1 percent of carbon dioxide in molecular nitrogen. We extended our study from no methane up to 1,000 ppm CH _{4}, which would be applicable to the postbiotic Earth (Tian et al., 2011). Lightning was simulated in the laboratory by a plasma generated with a

  7. Assessment of skin sensitization under REACH: A case report on vehicle choice in the LLNA and its crucial role preventing false positive results.

    Science.gov (United States)

    Watzek, Nico; Berger, Franz; Kolle, Susanne Noreen; Kaufmann, Tanja; Becker, Matthias; van Ravenzwaay, Bennard

    2017-04-01

    In the EU, chemicals with a production or import volume in quantities of one metric ton per year or more have to be tested for skin sensitizing properties under the REACH regulation. The murine Local Lymph Node Assay (LLNA) and its modifications are widely used to fulfil the data requirement, as it is currently considered the first-choice method for in vivo testing to cover this endpoint. This manuscript describes a case study highlighting the importance of understanding the chemistry of the test material during testing for 'skin sensitization' of MCDA (mixture of 2,4- and 2,6-diamino-methylcyclohexane) with particular focus on the vehicle used. While the BrdU-ELISA modification of the LLNA using acetone/olive oil (AOO) as vehicle revealed expectable positive results. However, the concentration control analysis unexpectedly revealed an instability of MCDA in the vehicle AOO. Further studies on the reactivity showed MCDA to rapidly react with AOO under formation of various imine structures, which might have caused the positive LLNA result. The repetition of the LLNA using propylene glycol (PG) as vehicle did not confirm the positive results of the LLNA using AOO. Finally, a classification of MCDA as skin sensitizer according to the Globally Harmonized System (GHS) was not justified. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Mandatory vaccinations in European countries, undocumented information, false news and the impact on vaccination uptake: the position of the Italian pediatric society.

    Science.gov (United States)

    Bozzola, Elena; Spina, Giulia; Russo, Rocco; Bozzola, Mauro; Corsello, Giovanni; Villani, Alberto

    2018-06-14

    High rates of vaccination coverage are important in preventing infectious diseases. Enforcing mandatory vaccinations is one of the strategies that some Countries adopted to protect the community when vaccination coverage is not satisfactory. In Italy, in 2017 vaccination against diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella became compulsory in childhood. In order to contrast vaccination policies, anti-vaccination campaigns contribute to the spread of fake news. Among them, there is the false information that Italy is the only one country with mandatory vaccination policy. Aim of our study is confronting vaccination policies in children under 18 months against among different European countries for the following vaccines: diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella. Information on policies of mandatory or recommended vaccinations of the European Countries were gathered by ECDC and compared to the Italian one. European Countries recommend or contemplate compulsory vaccines. Among them, eleven Countries (35.4%) have mandatory vaccinations for at least one out of diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella vaccine. Not only in Italy, vaccination against diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella is mandatory in children under 18 months. Other European countries adopted compulsory policies in order to prevent the spread of infectious diseases and to protect the community.

  9. The interaction between calreticulin and immunoglobulin G and immunoglobulin Y

    DEFF Research Database (Denmark)

    Møllegaard, Karen Mai; Duus, Karen; Træholt, Sofie Dietz

    2011-01-01

    accumulating in support of calreticulin as a polypeptide binding chaperone. In contrast to mammalian immunoglobulin G (IgG), which has complex type N-glycans, chicken immunoglobulin Y (IgY) possesses a monoglucosylated high mannose N-linked glycan, which is a ligand for calreticulin. Here, we have used solid...... and solution-phase assays to analyze the in vitro binding of calreticulin, purified from human placenta, to human IgG and chicken IgY in order to compare the interactions. In addition, peptides from the respective immunoglobulins were included to further probe the binding specificity of calreticulin....... The experiments demonstrate the ability of calreticulin to bind to denatured forms of both IgG and IgY regardless of the glycosylation state of the proteins. Furthermore, calreticulin exhibits binding to peptides (glycosylated and non-glycosylated) derived from trypsin digestion of both immunoglobulins...

  10. MARVELS-1: A FACE-ON DOUBLE-LINED BINARY STAR MASQUERADING AS A RESONANT PLANETARY SYSTEM AND CONSIDERATION OF RARE FALSE POSITIVES IN RADIAL VELOCITY PLANET SEARCHES

    International Nuclear Information System (INIS)

    Wright, Jason T.; Roy, Arpita; Mahadevan, Suvrath; Wang, Sharon X.; Fleming, Scott W.; Ford, Eric B.; Payne, Matt; Lee, Brian L.; Ge, Jian; Wang, Ji; Crepp, Justin R.; Gaudi, B. Scott; Eastman, Jason; Pepper, Joshua; Cargile, Phillip; Stassun, Keivan G.; Ghezzi, Luan; González-Hernández, Jonay I.; Wisniewski, John; Dutra-Ferreira, Leticia

    2013-01-01

    We have analyzed new and previously published radial velocity (RV) observations of MARVELS-1, known to have an ostensibly substellar companion in a ∼6 day orbit. We find significant (∼100 m s –1 ) residuals to the best-fit model for the companion, and these residuals are naïvely consistent with an interior giant planet with a P = 1.965 days in a nearly perfect 3:1 period commensurability (|P b /P c – 3| –4 ). We have performed several tests for the reality of such a companion, including a dynamical analysis, a search for photometric variability, and a hunt for contaminating stellar spectra. We find many reasons to be critical of a planetary interpretation, including the fact that most of the three-body dynamical solutions are unstable. We find no evidence for transits, and no evidence of stellar photometric variability. We have discovered two apparent companions to MARVELS-1 with adaptive optics imaging at Keck; both are M dwarfs, one is likely bound, and the other is likely a foreground object. We explore false-alarm scenarios inspired by various curiosities in the data. Ultimately, a line profile and bisector analysis lead us to conclude that the ∼100 m s –1 residuals are an artifact of spectral contamination from a stellar companion contributing ∼15%-30% of the optical light in the system. We conclude that origin of this contamination is the previously detected RV companion to MARVELS-1, which is not, as previously reported, a brown dwarf, but in fact a G dwarf in a face-on orbit.

  11. A cause of false positive of the whole body scanning with iodine 131: obstructive hydronephrosis; Une cause de faux-positif du balayage corps entier a l'iode 131: l'hydronephrose obstructive

    Energy Technology Data Exchange (ETDEWEB)

    Sellem, A.; Elbez, I.; Rejeb, O.; Elkadri, N.; Hammami, H. [Service de medecine nucleaire, hopital Militaire, Tunis, (Tunisia)

    2009-05-15

    The objective is to report the case of a differentiated carcinoma of the thyroid with a false positive aspect to the whole-body scanning with iodine 131 in relation with an accumulation of the tracer at the level of an obstructive appearance hydronephrosis. (N.C.)

  12. Heat treatment and false-positive heartworm antigen testing in ex vivo parasites and dogs naturally infected by Dirofilaria repens and Angiostrongylus vasorum

    Directory of Open Access Journals (Sweden)

    Luigi Venco

    2017-11-01

    Full Text Available Abstract Background Heartworm antigen testing is considered sensitive and specific. Currently available tests are reported as detecting a glycoprotein found predominantly in the reproductive tract of the female worm and can reach specificity close to 100%. Main concerns regard sensitivity in the case of light infections, the presence of immature females or cases of all-male infections. Research and development have been aimed at increasing sensitivity. Recently, heat treatment of serum prior to antigen testing has been shown to result in an increase in positive antigen test results, presumably due to disruption of natural antigen–antibody complexes. Cross-reactions in dogs with both natural and experimental infections with Angiostrongylus vasorum and Spirocerca lupi have been reported, but cross-reactions with other helminths have not been extensively studied. In order to evaluate potential cross-reactivity with other canine and feline parasites, two studies were performed. Study 1: Live adults of Dirofilaria immitis, Dirofilaria repens, Toxocara canis, Toxocara cati, Dipylidium caninum, Taenia taeniaeformis and Mesocestoides spp. larvae were washed and incubated in tubes with saline solution. All worms were alive at the time of removal from the saline. Saline solutions containing excretory/secretory antigens were then tested for heartworm with six different, commercially available antigen tests. All results were evaluated blind by three of the authors. Study 2: Sera from dogs with natural infections by A. vasorum or D. repens, living in areas free of heartworm disease, were tested with the same tests before and after heat treatment (103 °C for 10 min. Results Results suggest that antigens detected by currently available tests are not specific for D. immitis. They may give positive results through detection of different parasites’ antigens that are normally not released into the bloodstream or released in a low amount and/or bound to

  13. Different percentages of false-positive results obtained using five methods for the calculation of reference change values based on simulated normal and ln-normal distributions of data

    DEFF Research Database (Denmark)

    Lund, Flemming; Petersen, Per Hyltoft; Fraser, Callum G

    2016-01-01

    a homeostatic set point that follows a normal (Gaussian) distribution. This set point (or baseline in steady-state) should be estimated from a set of previous samples, but, in practice, decisions based on reference change value are often based on only two consecutive results. The original reference change value......-positive results. The aim of this study was to investigate false-positive results using five different published methods for calculation of reference change value. METHODS: The five reference change value methods were examined using normally and ln-normally distributed simulated data. RESULTS: One method performed...... best in approaching the theoretical false-positive percentages on normally distributed data and another method performed best on ln-normally distributed data. The commonly used reference change value method based on two results (without use of estimated set point) performed worst both on normally...

  14. Performance of the Epstein-Barr Virus and Herpes Simplex Virus Immunoglobulin M Assays on the Liaison Platform with Sera from Patients Displaying Acute Parvovirus B19 Infection▿

    Science.gov (United States)

    Costa, Elisa; Tormo, Nuria; Clari, María Ángeles; Bravo, Dayana; Muñoz-Cobo, Beatriz; Navarro, David

    2009-01-01

    Acute parvovirus B19 infection has been reported to cause false-positive results frequently in the Epstein-Barr (EBV) and herpes simplex virus (HSV) immunoglobulin M (IgM) assays from DiaSorin performed on the Liaison platform. We tested 65 sera from patients with a presumptive or conclusive diagnosis of acute parvovirus B19 infection in both assays and obtained no false-positive results in the EBV IgM test and 10.4% nonspecific reactivities in the HSV IgM assay. Our data support the specificity of both assays in this clinical setting. PMID:19571110

  15. Clinical applications of immunoglobulin: update

    Directory of Open Access Journals (Sweden)

    Marcia Cristina Zago Novaretti

    2011-06-01

    Full Text Available Human immunoglobulin is the most used blood product in the clinical practice. Immunoglobulin applications have increased quickly since the elucidation of its immunomodulatory and antiinflammatory properties which turned this blood product into a precious tool in the treatment of numerous diseases that present with humoral immune deficiency or that cause immune system dysfunction. Currently, the approved indications for Ig are: primary immunodeficiencies, secondary immunodeficiencies (multiple myeloma or chronic lymphoid leukemia, Kawasaki syndrome, immune thrombocytopenic purpura, Guillain Barré syndrome, graft-versus-host disease following bone marrow transplantation and repeat infections in HIV children. On the other hand, there are numerous "off-label" indications of immunoglobulin, which represent 20-60% of all clinical applications of this drug. It is important to study all these indications and, above all, the scientific evidence for its use, in order to provide patients with a new therapeutic option without burdening the health system. This review results from a wide selection of papers identified in the Pubmed and Lilacs scientific electronic databases. A group of descriptors were used from human immunoglobulin to the names of each disease that immunoglobulin is clinically applied. Our main objective is to list the numerous indications of immunoglobulin, both authorized and "off-label" and to analyze these indications in the light of the most recent scientific evidence.

  16. Evaluation of HIV testing algorithms in Ethiopia: the role of the tie-breaker algorithm and weakly reacting test lines in contributing to a high rate of false positive HIV diagnoses.

    Science.gov (United States)

    Shanks, Leslie; Siddiqui, M Ruby; Kliescikova, Jarmila; Pearce, Neil; Ariti, Cono; Muluneh, Libsework; Pirou, Erwan; Ritmeijer, Koert; Masiga, Johnson; Abebe, Almaz

    2015-02-03

    In Ethiopia a tiebreaker algorithm using 3 rapid diagnostic tests (RDTs) in series is used to diagnose HIV. Discordant results between the first 2 RDTs are resolved by a third 'tiebreaker' RDT. Médecins Sans Frontières uses an alternate serial algorithm of 2 RDTs followed by a confirmation test for all double positive RDT results. The primary objective was to compare the performance of the tiebreaker algorithm with a serial algorithm, and to evaluate the addition of a confirmation test to both algorithms. A secondary objective looked at the positive predictive value (PPV) of weakly reactive test lines. The study was conducted in two HIV testing sites in Ethiopia. Study participants were recruited sequentially until 200 positive samples were reached. Each sample was re-tested in the laboratory on the 3 RDTs and on a simple to use confirmation test, the Orgenics Immunocomb Combfirm® (OIC). The gold standard test was the Western Blot, with indeterminate results resolved by PCR testing. 2620 subjects were included with a HIV prevalence of 7.7%. Each of the 3 RDTs had an individual specificity of at least 99%. The serial algorithm with 2 RDTs had a single false positive result (1 out of 204) to give a PPV of 99.5% (95% CI 97.3%-100%). The tiebreaker algorithm resulted in 16 false positive results (PPV 92.7%, 95% CI: 88.4%-95.8%). Adding the OIC confirmation test to either algorithm eliminated the false positives. All the false positives had at least one weakly reactive test line in the algorithm. The PPV of weakly reacting RDTs was significantly lower than those with strongly positive test lines. The risk of false positive HIV diagnosis in a tiebreaker algorithm is significant. We recommend abandoning the tie-breaker algorithm in favour of WHO recommended serial or parallel algorithms, interpreting weakly reactive test lines as indeterminate results requiring further testing except in the setting of blood transfusion, and most importantly, adding a confirmation test

  17. PET Study with false positive {sup 68}Ga-Dotatate caused by the presence of an accessory spleen; Estudio PET con {sup 68}Ga-Dotatate falso positivo causado por la presencia de un bazo accesorio

    Energy Technology Data Exchange (ETDEWEB)

    Massardo, Teresa [Centro PET de Imagenes Moleculares, Hospital Militar de Santiago / Seccion Medicina Nuclear, Departamento Medicina, Hospital Clinico Universidad de Chile. Santiago (Chile); Jofre, Josefina; Sierralta, M. Paulina; Canessa, Jose [Centro PET de Imagenes Moleculares, Hospital Militar de Santiago. Santiago (Chile)

    2013-05-31

    Neuroendocrine tumors with somatostatin receptor expression are suitable for imaging with somatostatin analogues. {sup 68}Ga-labeled peptides are useful for the diagnosis, staging and assessment of therapeutic response of these tumors. However, for a correct interpretation it is necessary to know the normal biodistribution of somatostatin receptors in the body. Asymmetric adrenal uptake may be a normal variant to cause confusion, or an accessory or ectopic spleen can lead to a false positive result. We report a case of asymmetric adrenal uptake which was correctly considered as a normal variant, but an accessory spleen caused the false impression of being a metastasis from a previously resected primary carcinoid tumor.

  18. HAMS: High-Affinity Mass Spectrometry Screening. A High-Throughput Screening Method for Identifying the Tightest-Binding Lead Compounds for Target Proteins with No False Positive Identifications.

    Science.gov (United States)

    Imaduwage, Kasun P; Go, Eden P; Zhu, Zhikai; Desaire, Heather

    2016-11-01

    A major challenge in drug discovery is the identification of high affinity lead compounds that bind a particular target protein; these leads are typically identified by high throughput screens. Mass spectrometry has become a detection method of choice in drug screening assays because the target and the ligand need not be modified. Label-free assays are advantageous because they can be developed more rapidly than assays requiring labels, and they eliminate the risk of the label interfering with the binding event. However, in commonly used MS-based screening methods, detection of false positives is a major challenge. Here, we describe a detection strategy designed to eliminate false positives. In this approach, the protein and the ligands are incubated together, and the non-binders are separated for detection. Hits (protein binders) are not detectable by MS after incubation with the protein, but readily identifiable by MS when the target protein is not present in the incubation media. The assay was demonstrated using three different proteins and hundreds of non-inhibitors; no false positive hits were identified in any experiment. The assay can be tuned to select for ligands of a particular binding affinity by varying the quantity of protein used and the immobilization method. As examples, the method selectively detected inhibitors that have K i values of 0.2 μM, 50 pM, and 700 pM. These findings demonstrate that the approach described here compares favorably with traditional MS-based screening methods. Graphical Abstract ᅟ.

  19. Chemical applicability domain of the Local Lymph Node Assay (LLNA) for skin sensitisation potency. Part 3. Apparent discrepancies between LLNA and GPMT sensitisation potential: False positives or differences in sensitivity?

    Science.gov (United States)

    Roberts, David W; Schultz, Terry W; Api, Anne Marie

    2016-10-01

    The Local Lymph Node Assay (LLNA) is the gold standard regulatory toxicology test for skin sensitisation along with the guinea pig maximisation test (GPMT). Compared with the GPMT, LLNA uses fewer animals, it is quantitative, and it gives a numerical prediction of potency. However several concerns have been raised with this assay, mainly related to false positives and false negatives. Over the years, many authors, including the developers of the assay, have presented cases where there have been discrepancies between the GMPT and LLNA results. Several theories have been put forward for these discrepancies, the main one being the "over-sensitivity" of the GPMT. This paper analyses the data from a systematic study, published in three papers from 2008 to 2011, covering several classes of chemicals, in particular unsaturated fatty acids, sugar surfactants and ethoxylated alcohols, with many cases of chemicals testing positive in the LLNA being negative in the GPMT. Based on consideration of reaction chemistry and structural alerts, it is concluded that these discrepancies are not LLNA false positives, but can be rationalised in terms of the different protocols of the assays. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Modeling Kepler Transit Light Curves as False Positives: Rejection of Blend Scenarios for Kepler-9, and Validation of Kepler-9 d, a Super-Earth-Size Planet in a Multiple System

    Science.gov (United States)

    Torres, Guillermo; Fressin, Francois; Batalha, Natalie M.; Borucki, William J.; Brown, Timothy M.; Bryson, Stephen T.; Buchhave, Lars A.; Charbonneau, David; Ciardi, David R.; Dunham, Edward W.; hide

    2011-01-01

    Light curves from the Kepler Mission contain valuable information on the nature of the phenomena producing the transit-like signals. To assist in exploring the possibility that they are due to an astrophysical false positive we describe a procedure (BLENDER) to model the photometry in terms of a blend rather than a planet orbiting a star. A blend may consist of a background or foreground eclipsing binary (or star-planet pair) whose eclipses are attenuated by the light of the candidate and possibly other stars within the photometric aperture. We apply BLENDER to the case of Kepler-9 (KIC 3323887), a target harboring two previously confirmed Saturn-size planets (Kepler-9 b and Kepler-9 c) showing transit timing variations, and an additional shallower signal with a 1.59 day period suggesting the presence of a super-Earth-size planet. Using BLENDER together with constraints from other follow-up observations we are able to rule out all blends for the two deeper signals and provide independent validation of their planetary nature. For the shallower signal, we rule out a large fraction of the false positives that might mimic the transits. The false alarm rate for remaining blends depends in part (and inversely) on the unknown frequency of small-size planets. Based on several realistic estimates of this frequency, we conclude with very high confidence that this small signal is due to a super-Earth-size planet (Kepler-9 d) in a multiple system, rather than a false positive. The radius is determined to be 1.64(exp)(sub-14),R, and current spectroscopic observations are as yet insufficient to establish its mass.

  1. INTRAVENOUS IMMUNOGLOBULIN IN PEDIATRIC RHEUMATOLOGY PRACTICE

    Directory of Open Access Journals (Sweden)

    E. I. Alexeeva

    2015-01-01

    Full Text Available Modern successful treatment of rheumatic diseases is impossible without the use of intravenous immunoglobulin. The use of intravenous immunoglobulin is based on strict indications developed as a result of long-term multicenter controlled studies. The article highlights the issues of using immunoglobulin in pediatric rheumatology practice, and provides the review of literature with the results from the evaluation of the efficiency of intravenous immunoglobulin confirming the efficiency of the drug only for certain rheumatic diseases. 

  2. Serology and immunoglobulin profile in rheumatoid arthritis.

    Science.gov (United States)

    Adhya, S; Chakraborty, G; Hajra, B; Bhattacharya, S; Sikdar, P K; Sinha, S; Banerjee, P P; Ghosh, E; Chakraborty, P

    1998-01-01

    One hundred and twenty cases of clinically diagnosed rheumatoid arthritis, 80 non-rheumatoid cases suffering from various other diseases and 40 healthy individuals were investigated for the presence of rheumatoid factor, quantitation of serum immunoglobulin, demonstration of ANA and LE cell phenomenon. Microlatex agglutination test of serum for rheumatoid factor showed 56.6% positivity in rheumatoid group and 3.7% positivity in non-rheumatoid group. All three serum immunoglobulins (IgG, IgM, IgA) were raised in serum in significant titre in cases of rheumatoid arthritis, whereas only IgA lever was elevated in the group of non-rheumatoid diseases. ANA and LE cell phenomenon were observed in 11.7% and 4.4% cases of rheumatoid arthritis who had severe underlying disease. In non-rheumatoid group, only one of 6 cases of systemic lupus erythematosus showed rheumatoid factor and that too in an insignificant titre (less than 1:20). Synovium and synovial fluid contained plenty of plasma cells and lymphocytes. It has been observed that RF appears first in synovial fluid and it may take several months to a year to attain detectable level in serum.

  3. Immunoglobulin adsorption on modified surfaces

    NARCIS (Netherlands)

    Bremer, M.G.E.G.

    2001-01-01

    Preservation of biological functioning of proteins during immobilisation is of special interest in various biomedical and biotechnical applications. In industry physical adsorption of immunoglobulins (IgGs) onto solid surfaces is still the predominant immobilisation procedure because it is

  4. Utility of the indium 111-labeled human immunoglobulin G scan for the detection of focal vascular graft infection

    International Nuclear Information System (INIS)

    LaMuraglia, G.M.; Fischman, A.J.; Strauss, H.W.; Keech, F.; Wilkinson, R.; Callahan, R.J.; Khaw, B.A.; Rubin, R.H.

    1989-01-01

    The ability to diagnose and localize vascular graft infections has been a major challenge. Recent studies in animal models and humans with focal bacterial infection have shown that radiolabeled, polyclonal, human immunoglobulin G accumulates at the site of inflammation and can serve as the basis for an imaging technique. This study investigated this new technique for the diagnosis and localization of vascular graft infections. Twenty-five patients with suspected vascular infections involving grafts (22), atherosclerotic aneurysms (2), and subclavian vein thrombophlebitis (1) were studied. Gamma camera images of the suspected area were obtained between 5 and 48 hours after intravenous administration of 1.5 to 2.0 mCi (56 to 74 mBq) of indium 111-labeled, human, polyclonal immunoglobulin G. Scan results were interpreted without clinical information about the patient and were subsequently correlated with surgical findings, other imaging modalities, and/or clinical follow-up. In 10 of 10 patients found to have positive scan results, localized infections were confirmed at the involved sites. In 14 of 15 patients whose scan results were interpreted as negative, no vascular infections were identified at follow-up. The patient with false-negative results and recurrent bacteremia from an aortoduodenal fistula was found to have a negative scan outcome at a time when his disease was quiescent. These data suggest that nonspecific, human, indium 111-labeled immunoglobulin G scanning can be a useful noninvasive means of localizing vascular infections

  5. Comparison of false-negative/positive results of intraoperative evoked potential monitoring between no and partial neuromuscular blockade in patients receiving propofol/remifentanil-based anesthesia during cerebral aneurysm clipping surgery: A retrospective analysis of 685 patients.

    Science.gov (United States)

    Kim, Sung-Hoon; Jin, Seok-Joon; Karm, Myong-Hwan; Moon, Young-Jin; Jeong, Hye-Won; Kim, Jae-Won; Ha, Seung-Il; Kim, Joung-Uk

    2016-08-01

    Although the elicited responses of motor evoked potential (MEP) monitoring are very sensitive to suppression by anesthetic agents and muscle relaxants, the use of neuromuscular blockade (NMB) during MEP monitoring is still controversial because of serious safety concerns and diagnostic accuracy. Here, we evaluated the incidence of unacceptable movement and compared false-negative MEP results between no and partial NMB during cerebral aneurysm clipping surgery. We reviewed patient medical records for demographic data, anesthesia regimen, neurophysiology event logs, MEP results, and clinical outcomes. Patients were divided into 2 groups according to the intraoperative use of NMB: no NMB group (n = 276) and partial NMB group (n = 409). We compared the diagnostic accuracy of MEP results to predict postoperative outcomes between both groups. Additionally, we evaluated unwanted patient movement during MEP monitoring in both groups. Of the 685 patients, 622 (90.8%) manifested no intraoperative changes in MEP and no postoperative motor deficits. Twenty patients showed postoperative neurologic deficits despite preserved intraoperative MEP. False-positive MEP results were 3.6% in the no NMB group and 3.9% in the partial NMB group (P = 1.00). False-negative MEP results were 1.1% in the no NMB group and 4.2% in the partial NMB group (P = 0.02). No spontaneous movement or spontaneous respiration was observed in either group. Propofol/remifentanil-based anesthesia without NMB decreases the stimulation intensity of MEPs, which may reduce the false-negative ratio of MEP monitoring during cerebral aneurysm surgery. Our anesthetic protocol enabled reliable intraoperative MEP recording and patient immobilization during cerebral aneurysm clipping surgery.

  6. Predictive value of minimal residual disease in Philadelphia-chromosome-positive acute lymphoblastic leukemia treated with imatinib in the European intergroup study of post-induction treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia, based on immunoglobulin/T-cell receptor and BCR/ABL1 methodologies

    Science.gov (United States)

    Cazzaniga, Giovanni; De Lorenzo, Paola; Alten, Julia; Röttgers, Silja; Hancock, Jeremy; Saha, Vaskar; Castor, Anders; Madsen, Hans O.; Gandemer, Virginie; Cavé, Hélène; Leoni, Veronica; Köhler, Rolf; Ferrari, Giulia M.; Bleckmann, Kirsten; Pieters, Rob; van der Velden, Vincent; Stary, Jan; Zuna, Jan; Escherich, Gabriele; zur Stadt, Udo; Aricò, Maurizio; Conter, Valentino; Schrappe, Martin; Valsecchi, Maria Grazia; Biondi, Andrea

    2018-01-01

    The prognostic value of minimal residual disease (MRD) in Philadelphia-chromosome-positive (Ph+) childhood acute lymphoblastic leukemia (ALL) treated with tyrosine kinase inhibitors is not fully established. We detected MRD by real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes (IG/TR) and/or BCR/ABL1 fusion transcript to investigate its predictive value in patients receiving Berlin-Frankfurt-Münster (BFM) high-risk (HR) therapy and post-induction intermittent imatinib (the European intergroup study of post-induction treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia (EsPhALL) study). MRD was monitored after induction (time point (TP)1), consolidation Phase IB (TP2), HR Blocks, reinductions, and at the end of therapy. MRD negativity progressively increased over time, both by IG/TR and BCR/ABL1. Of 90 patients with IG/TR MRD at TP1, nine were negative and none relapsed, while 11 with MRD<5×10−4 and 70 with MRD≥5×10−4 had a comparable 5-year cumulative incidence of relapse of 36.4 (15.4) and 35.2 (5.9), respectively. Patients who achieved MRD negativity at TP2 had a low relapse risk (5-yr cumulative incidence of relapse (CIR)=14.3[9.8]), whereas those who attained MRD negativity at a later date showed higher CIR, comparable to patients with positive MRD at any level. BCR/ABL1 MRD negative patients at TP1 had a relapse risk similar to those who were IG/TR MRD negative (1/8 relapses). The overall concordance between the two methods is 69%, with significantly higher positivity by BCR/ABL1. In conclusion, MRD monitoring by both methods may be functional not only for measuring response but also for guiding biological studies aimed at investigating causes for discrepancies, although from our data IG/TR MRD monitoring appears to be more reliable. Early MRD negativity is highly predictive of favorable outcome. The earlier MRD negativity is achieved, the better the prognosis. PMID

  7. False-positive uptake on 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) in oncological imaging

    International Nuclear Information System (INIS)

    Culverwell, A.D.; Scarsbrook, A.F.; Chowdhury, F.U.

    2011-01-01

    With the increasing utilization of integrated positron-emission tomography/computed tomography (PET/CT) using the glucose analogue 2-[ 18 F]-fluoro-2-deoxy-D-glucose (FDG) in oncological imaging, it is important for radiologists and nuclear medicine physicians to be aware that FDG uptake is not specific for malignancy, as many different physiological variants and benign pathological conditions can also exhibit increased glucose metabolism. Such false-positive FDG uptake often arises outside the area of primary interest and may mimic malignant disease, thereby confounding accurate interpretation of PET/CT studies. With the use of illustrative clinical cases, this article will provide a systematic overview of potential interpretative pitfalls and illustrate how such unexpected findings can be appropriately evaluated.

  8. Radioimmunoassay to quantitatively measure cell surface immunoglobulins

    International Nuclear Information System (INIS)

    Krishman, E.C.; Jewell, W.R.

    1975-01-01

    A radioimmunoassay techniques developed to quantitatively measure the presence of immunoglobulins on the surface of cells, is described. The amount of immunoglobulins found on different tumor cells varied from 200 to 1140 ng/10 6 cells. Determination of immunoglobulins on the peripheral lymphocytes obtained from different cancer patients varied between 340 to 1040 ng/10 6 cells. Cultured tumor cells, on the other hand, were found to contain negligible quantities of human IgG [pt

  9. Comparison of techniques of detecting immunoglobulin-binding protein reactivity to immunoglobulin produced by different avian and mammalian species.

    Science.gov (United States)

    Justiz-Vaillant, A A; Akpaka, P E; McFarlane-Anderson, N; Smikle, M F

    2013-01-01

    The rationale of this study was to use several immunological assays to investigate the reactivity of immunoglobulin binding protein (IBP) to immunoglobulins from various avian and mammalian species. The IBP studied were Staphylococcal protein A (SpA), Streptococcal protein G (SpG), Peptostreptococcal protein L (SpL) and recombinant protein LA (SpLA). The various immunological techniques used were double immunodiffusion (Ouchterlony technique) that tested positive high protein reactivities, direct and competitive enzyme-linked immunosorbent assays (ELISAs) that tested moderate and low positive protein binding capacities, respectively. In addition to sandwich ELISAs, immunoblot analyses and Ig-purification by SpA-affinity chromatography, which were sensitive tests and helpful in the screening and confirmatory tests were also used. The Ouchterlony technique showed that compared to the other proteins, SpLA had the highest range of reactivity with animal sera and purified immunoglobulins while SpL was least reactive. With the direct ELISA, SpL reacted with the raccoon sera, rabbit IgG and with IgY from bantam hens and pigeons. While with the direct ELISA, SpA reacted with sera from skunk, coyote, raccoon, mule, donkey and human. The sandwich ELISA revealed high reactivity of both SpG and SpLA with mammalian sera titres ranging from 1:32 (raccoon serum) to 1:1024 (mule and donkey sera). These results suggest that IBP can be used for the detection of immunoglobulin using various immunological assays and this is important for the diagnosis of infectious diseases in animal and bird populations studied and in the purification of immunoglobulins.

  10. Systemic True False

    African Journals Online (AJOL)

    Preferred Customer

    ):. (a). (b). (c). (d). Answer: True systemics are (b & c); False Systemics (a & d). For more examples, see (10 and 11). Na2O2. NaCl. Na. HCl heat /excess. (O). 300°C electrolysis. (molten). NaOH. NaCl. Na. HCl. H2O electrolysis. (solution). NaCl.

  11. [Correlation of serum IL-16, IL-18 levels and immunoglobulins in children with asthma].

    Science.gov (United States)

    Xue, Yi-Nan; Zou, Xian-De; Wu, Jia-Ling

    2006-02-01

    This study examined the changes of serum levels of interleukin (IL)-16, IL-18 and immunoglobulins and the correlation of serum IL-16, IL-18 levels and immunoglobulins in children with asthma and aimed to explore the role of IL-16, IL-18 and immunoglobulins in the pathogenesis of asthma. Thirty-four children with asthma and 21 age and gender-matched healthy children were enrolled in this study. The levels of IL-16, IL-18 and immunoglobulin E (IgE) were determined using ELISA. Immunoglobulin G (IgG), immunoglobulin M (IgM) and immunoglobulin A (IgA) were detected by immunoturbidimetry. The levels of IL-16, IL-18 and IgE in patients with asthma at both acute attack and convalescence stages were significantly higher than those in healthy controls. An increased IgG and a decreased IgA levels were found in asthmatic patients at the acute attack stage. There was a positive correlation between the IL-16 and IL-18 levels at both acute attack and convalescence stages of asthma (r=0.70, P attack stage of asthma (r=0.624, P asthma. The immunologic imbalance exists in children with asthma at both acute attack and convalescence stages. Anti-allergic therapy should be administered through the acute attack to the convalescence stages of asthma.

  12. The diagnosis of nonclassic congenital adrenal hyperplasia due to 21-hydroxylase deficiency, based on serum basal or post-ACTH stimulation 17-hydroxyprogesterone, can lead to false-positive diagnosis.

    Science.gov (United States)

    Ambroziak, Urszula; Kępczyńska-Nyk, Anna; Kuryłowicz, Alina; Małunowicz, Ewa Maria; Wójcicka, Anna; Miśkiewicz, Piotr; Macech, Magdalena

    2016-01-01

    As nonclassic congenital adrenal hyperplasia (NCCAH) needs to be taken into account in women with hyperandrogenism, we aimed to assess whether the recommended level of poststimulated 17OHP ≥30 nmol/l confirms NCCAH. Forty, consecutive women with biochemical and/or clinical hyperandrogenism (aged 25·4, 18-38) suspected of having NCCAH were recruited to the study. In patients with 17OHP level between 5·1 and 29·9 nmol/l an ACTH stimulation test was performed. In patients with basal or poststimulated 17OHP ≥30 nmol/l, twenty-four-hour urinary steroid profile (USP) analysis was performed and CYP21A2 mutation was assessed. In selected patients with poststimulated 17OHP basal or poststimulated 17OHP ≥30 nmol/l (group A) and with poststimulated 17OHP basal or poststimulated 17OHP ≥30 nmol/l was found in 21, but NCCAH was confirmed by USP followed by genetic testing only in 5 (24%). Four patients were diagnosed as heterozygotes, and in twelve, no CYP21A2 mutation was detected. The diagnosis of NCCAH based only on serum 17OHP measurements (basal or poststimulated) may lead to false-positive diagnosis when performed by immunoassay with a cut-off value of ≥30 nmol/l. The definitive diagnosis can be established based on USP and/or genetic testing. © 2015 John Wiley & Sons Ltd.

  13. Detection of inflammatory lesions with radiolabelled immunoglobulins

    International Nuclear Information System (INIS)

    Blok, D.; Rijksuniversiteit Leiden; Ogtrop, M. van; Arndt, J.W.; Camps, J.A.J.; Feitsma, R.I.J.; Pauwels, E.K.J.

    1990-01-01

    Previous reports on the use of radiolabelled immunoglobulins led us to undertake a pilot experiment in an animal model to investigate the potentials sodium pertechnate Tc 99m-immunoglobulin scintigraphy in the detection of infectious foci. Mice infected in one leg with staphylococcus infection in were injected with sodium pertechnote Tc 99m-immunoglobulin, albumin aggregated technetium Tc 99m or gallium citrate Ga 67. The results obtained by scintigraphy suggested a specific accumulation of radiolabelled immunoglobulin at the site of infection. Visualization of the infection and the image quality, especially the 6- and 24-h images, were clearly enhanced after the use of immunoglobulin preparations as compared with those labelled with gallium. (orig.)

  14. Baryogenesis in false vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Yuta [KEK Theory Center, IPNS, KEK, Tsukuba, Ibaraki (Japan); Yamada, Masatoshi [Kanazawa University, Institute for Theoretical Physics, Kanazawa (Japan)

    2017-09-15

    The null result in the LHC may indicate that the standard model is not drastically modified up to very high scales, such as the GUT/string scale. Having this in the mind, we suggest a novel leptogenesis scenario realized in the false vacuum of the Higgs field. If the Higgs field develops a large vacuum expectation value in the early universe, a lepton number violating process is enhanced, which we use for baryogenesis. To demonstrate the scenario, several models are discussed. For example, we show that the observed baryon asymmetry is successfully generated in the standard model with higher-dimensional operators. (orig.)

  15. O método da falsa posição na história e na educação matemática The false position method in history and in mathematics education

    Directory of Open Access Journals (Sweden)

    Cleide Farias de Medeiros

    2004-12-01

    Full Text Available Este texto coloca em uma perspectiva histórica o tratamento algébrico precoce que, costumeiramente, é dedicado ao ensino elementar da Aritmética. Defendendo que um tal tratamento algébrico precoce carrega vários pontos negativos para a formação do educando, o texto discute o "método da falsa posição" como uma alternativa viável para um tal ensino introdutório. Apontando as raízes históricas de tal método, o texto procura evidenciar as origens, aplicações e várias formas de visualizar este procedimento iterativo, desde a manipulação de materiais concretos, passando por aplicações geométricas, até atingir o Cálculo Numérico, como um dos procedimentos iterativos na resolução de equações lineares. Uma das conclusões é que, embora não seja o referido método, em sua forma mais simples, nenhum substitutivo para a resolução algébrica simbólica e moderna de equações e de sistemas de equações, ele se constitui certamente em um precioso trampolim para iniciarmos o salto em direção a um estudo mais formalizado. Particularmente, o método da falsa posição revela-se uma utilíssima ferramenta pedagógica na Educação Matemática, principalmente quando vinculado às suas origens históricas, suas abordagens concretas iniciais e suas associações com a Geometria e a Geometria Analítica.This text is a historical perspective on the early algebraic approach that is usually applied to the elementary teaching of Arithmetic. By arguing that such an initial algebraic treatment contains several drawbacks for elementary education, the ‘false position method' is discussed and is presented as a viable alternative for such introductory teaching. By pointing out the historical roots of the method, the text tries to make clear several ways of visualising this iterative procedure. This is done by incorporating the use of manipulatives and geometrical applications as well as the use of numerical calculus as an iterative

  16. False memories and confabulation.

    Science.gov (United States)

    Johnson, M K; Raye, C L

    1998-04-01

    Memory distortions range from the benign (thinking you mailed a check that you only thought about mailing), to the serious (confusing what you heard after a crime with what you actually saw), to the fantastic (claiming you piloted a spaceship). We review theoretical ideas and empirical evidence about the source monitoring processes underlying both true and false memories. Neuropsychological studies show that certain forms of brain damage (such as combined frontal and medial-temporal lesions) might result in profound source confusions, called confabulations. Neuroimaging techniques provide new evidence regarding more specific links between underlying brain mechanisms and the normal cognitive processes involved in evaluating memories. One hypothesis is that the right prefrontal cortex (PFC) subserves heuristic judgments based on easily assessed qualities (such as familiarity or perceptual detail) and the left PFC (or the right and left PFC together) subserves more systematic judgments requiring more careful analysis of memorial qualities or retrieval and evaluation of additional supporting or disconfirming information. Such heuristic and systematic processes can be disrupted not only by brain damage but also, for example, by hypnosis, social demands and motivational factors, suggesting caution in the methods used by `memory exploring' professions (therapists, police officers, lawyers, etc.) in order to avoid inducing false memories.

  17. Optimized localization of bacterial infections with technetium-99m labelled human immunoglobulin after protein charge selection

    International Nuclear Information System (INIS)

    Welling, M.; Feitsma, H.I.J.; Calame, W.; Ensing, G.J.; Goedemans, W.; Pauwels, E.K.J.

    1994-01-01

    To improve the scintigraphic detection of bacterial infections a protein charge-purified fraction of polyclonal human immunoglobulin was applied as a radiopharmaceutical. This purification was achieved by attaching the immunoglobulin to an anion-exchanger column and by obtaining the column-bound fraction with buffer. The binding to bacteria in vitro and the target to non-target ratios of an experimental thigh infection with Staphylococcus aureus or Klebsiella pneumoniae in mice were evaluated to compare the purified and the unpurified immunoglobulin. The percentage of binding to all gram-positive and gram-negative bacteria used in this study was significantly (P 99m Tc-labelled protein charge-purified polyclonal human immunoglobulin was administered intravenously. At all time intervals the target (infected thighs) to non-target (non-infected thighs) ratios for both infections were significantly higher (P 99m Tc-labelled protein charge-purified immunoglobulin localizes both a gram-positive and a gram-negative thigh infection more intensely and faster than 99m Tc-labelled unpurified immunoglobulin. (orig.)

  18. False color viewing device

    International Nuclear Information System (INIS)

    Kronberg, J.W.

    1992-01-01

    A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage. 7 figs

  19. False positive reaction due to endogenous biotin activity in glandular epithelium of decidua Reação falso positiva em epitélio glandular da decídua devido a atividade endógena de biotina

    Directory of Open Access Journals (Sweden)

    Liliana Cruz Spano

    2005-06-01

    Full Text Available Biotin-labeled probe was used in an in situ hybridisation assay to localize virus infection in formalin-fixed, paraffin embedded tissues taken from eleven abortion cases. Probes for human cytomegalovirus (HCMV, human Parvovirus B19 (B19 and human adenovirus type 2 (HAd2, were labeled with biotin-11-dUTP by nick-translation reaction. Streptavidin-alkaline-phosphatase (SAP was used to detect biotin, followed by 4-nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP solution. Positive reaction was observed in nucleus of glandular ephitelium cells of decidua either in positive or in negative control at first and second gestational trimester. The reaction was not inhibited with blocking solution for alkaline phosphatase endogenous activity and it persisted even with probes omission. The use of adequate negative control permitted to reveal the presence of nuclear biotin in glandular epithelium of decidua, responsible for false positivity in detection systems involving streptavidin biotin system (StrepABC. The stained cells resembled to cytophatic effect due to herpesvirus, which could induce further misinterpretation. The results obtained in this study strongly recommend that DNA detection by in situ hybridisation reaction in gestational endometrium should be done without using StrepABC system.Sondas marcadas com biotina foram utilizadas neste trabalho para detecção de infecção viral por hibridização in situ em tecidos fixados com formalina e embebidos em parafina de 11 casos obtidos de abortamento. Sondas para citomegalovírus humano (HCMV, parvovírus B19 humano (B19 e adenovírus humano tipo 2 (HAd2, foram marcadas com biotina-11-dUTP através da reação de nick-translation. Estreptavidina conjugada com fosfatase alcalina (SAP seguida por solução de 4-nitro-azul de tetrazolio/5-bromo-4-cloro-3-indolil fosfato (NBT/BCIP foram utilizadas para detecção da biotina após a reação de hibridização. Reação positiva foi

  20. Use of intravenous immunoglobulins in clinical practice

    Directory of Open Access Journals (Sweden)

    E.K. Donyush

    2011-01-01

    Full Text Available Immunoglobulins are main component of immune defense; they take part in anti-infectious resistance of organism and regulate processes of different immune reactions. Intravenous immunoglobulins are the most frequently used products made from donor blood plasma. The need in these drugs is steadily increasing during last 15–20 years, and indications are widening due to modern hightechnology methods of production and cleaning. The article presents modern data on formula, mechanisms of action and indications for different groups of intravenous immunoglobulins (standard, hyperimmune, fortified and description of possible adverse events.Key words: immuglobulines, prophylaxis, treatment, unfavorable reaction, children.

  1. A very low geno2pheno false positive rate is associated with poor viro-immunological response in drug-naïve patients starting a first-line HAART.

    Science.gov (United States)

    Armenia, Daniele; Soulie, Cathia; Di Carlo, Domenico; Fabeni, Lavinia; Gori, Caterina; Forbici, Federica; Svicher, Valentina; Bertoli, Ada; Sarmati, Loredana; Giuliani, Massimo; Latini, Alessandra; Boumis, Evangelo; Zaccarelli, Mauro; Bellagamba, Rita; Andreoni, Massimo; Marcelin, Anne-Geneviève; Calvez, Vincent; Antinori, Andrea; Ceccherini-Silberstein, Francesca; Perno, Carlo-Federico; Santoro, Maria Mercedes

    2014-01-01

    We previously found that a very low geno2pheno false positive rate (FPR ≤ 2%) defines a viral population associated with low CD4 cell count and the highest amount of X4-quasispecies. In this study, we aimed at evaluating whether FPR ≤ 2% might impact on the viro-immunological response in HIV-1 infected patients starting a first-line HAART. The analysis was performed on 305 HIV-1 B subtype infected drug-naïve patients who started their first-line HAART. Baseline FPR (%) values were stratified according to the following ranges: ≤ 2; 2-5; 5-10; 10-20; 20-60; >60. The impact of genotypically-inferred tropism on the time to achieve immunological reconstitution (a CD4 cell count gain from HAART initiation ≥ 150 cells/mm(3)) and on the time to achieve virological success (the first HIV-RNA measurement immunological reconstitution was overall 75.5%, and it was significantly lower for FPR ≤ 2 (54.1%) in comparison to other FPR ranks (78.8%, FPR 2-5; 77.5%, FPR 5-10; 71.7%, FPR 10-20; 81.8%, FPR 20-60; 75.1%, FPR >60; p = 0.008). The overall proportion of patients achieving virological success was 95.5% by 12 months of therapy. Multivariable Cox analyses showed that patients having pre-HAART FPR ≤ 2% had a significant lower relative adjusted hazard [95% C.I.] both to achieve immunological reconstitution (0.37 [0.20-0.71], p = 0.003) and to achieve virological success (0.50 [0.26-0.94], p = 0.031) than those with pre-HAART FPR >60%. Beyond the genotypically-inferred tropism determination, FPR ≤ 2% predicts both a poor immunological reconstitution and a lower virological response in drug-naïve patients who started their first-line therapy. This parameter could be useful to identify patients potentially with less chance of achieving adequate immunological reconstitution and virological undetectability.

  2. Perspectives on Immunoglobulins in colostrum and milk

    DEFF Research Database (Denmark)

    Hurley, W L; Theil, Peter Kappel

    2011-01-01

    Immunoglobulins form an important component of the immunological activity found in milk and colostrum. They are central to the immunological link that occurs when the mother transfers passive immunity to the offspring. The mechanism of transfer varies among mammalian species. Cattle provide...... a readily available immune rich colostrum and milk in large quantities, making those secretions important potential sources of immune products that may benefit humans. Immune milk is a term used to describe a range of products of the bovine mammary gland that have been tested against several human diseases....... The use of colostrum or milk as a source of immunoglobulins, whether intended for the neonate of the species producing the secretion or for a different species, can be viewed in the context of the types of immunoglobulins in the secretion, the mechanisms by which the immunoglobulins are secreted...

  3. Importance of neonatal immunoglobulin transfer for hippocampal development and behaviour in the newborn pig.

    Directory of Open Access Journals (Sweden)

    Kateryna Goncharova

    Full Text Available Neurological disorders are among the main clinical problems affecting preterm children and often result in the development of communication and learning disabilities later in life. Several factors are of importance for brain development, however the role of immunoglobulins (passive immunity transfer has not yet been investigated. Piglets are born agammaglobulinemic, as a result of the lack of transfer of maternal immunoglobulins in utero, thus, they serve as an ideal model to mimic the condition of immunoglobulin deficiency in preterm infants. Thirty six, unsuckled newborn piglets were fed an infant formula or colostrum and supplemented orally or intravenously with either species-specific or foreign immunoglobulin and then compared to both newborn and sow-reared piglets. Two days after the piglets were born behavioural tests (novel recognition and olfactory discrimination of conspecifics scent were performed, after which the piglets were sacrificed and blood, cerebrospinal fluid and hippocampi samples were collected for analyses. Both parameters of neuronal plasticity (neuronal maturation and synapse-associated proteins and behavioural test parameters appeared to be improved by the appearance of species-specific porcine immunoglulin in the circulation and cerebrospinal fluid of the piglets. In conclusion, we postulate possible positive clinical effects following intravenous infusion of human immunoglobulin in terms of neuronal plasticity and cognitive function in preterm infants born with low blood immunoglobulin levels.

  4. WPMSD: A Malicious Script Detection Method Inspired by the Process of Immunoglobulin Secretion

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2011-10-01

    Full Text Available Inspired by the process of immunoglobulin secretion in biological body, we present a Web Page Malicious Script Detection Method (WPMSD. In this paper, Firstly, the basic definitions of artificial immune items are given. Secondly, according to the spreading range of malicious script, the immunoglobulin number is changed as the detector clone proliferation is stimulated by malicious scripts. Further more, the nonlinear dynamics of antibody number is discussed. Thirdly, we propose a probability approach to trigger alarms to inform that the detected scripts are harmful. Finally, the WPMSD collects the effective immunoglobulin set based on Hidden Markov Model (HMM to update the detector gene library. Compared with the traditional immune based detection methods, such as Negative Selection Algorithm (NSA, Dynamic Colonel Selection (DynamiCS, and Variable size Detector (Vdetector, the false alarm rate of WPMSD has been reduced by 18.09%, 12.6%, and 7.47% respectively.

  5. Immunoglobulin E-Mediated Autoimmunity

    Directory of Open Access Journals (Sweden)

    Marcus Maurer

    2018-04-01

    Full Text Available The study of autoimmunity mediated by immunoglobulin E (IgE autoantibodies, which may be termed autoallergy, is in its infancy. It is now recognized that systemic lupus erythematosus, bullous pemphigoid (BP, and chronic urticaria, both spontaneous and inducible, are most likely to be mediated, at least in part, by IgE autoantibodies. The situation in other conditions, such as autoimmune uveitis, rheumatoid arthritis, hyperthyroid Graves’ disease, autoimmune pancreatitis, and even asthma, is far less clear but evidence for autoallergy is accumulating. To be certain of an autoallergic mechanism, it is necessary to identify both IgE autoantibodies and their targets as has been done with the transmembrane protein BP180 and the intracellular protein BP230 in BP and IL-24 in chronic spontaneous urticaria. Also, IgE-targeted therapies, such as anti-IgE, must have been shown to be of benefit to patients as has been done with both of these conditions. This comprehensive review of the literature on IgE-mediated autoallergy focuses on three related questions. What do we know about the prevalence of IgE autoantibodies and their targets in different diseases? What do we know about the relevance of IgE autoantibodies in different diseases? What do we know about the cellular and molecular effects of IgE autoantibodies? In addition to providing answers to these questions, based on a broad review of the literature, we outline the current gaps of knowledge in our understanding of IgE autoantibodies and describe approaches to address them.

  6. Emotions and false memories: valence or arousal?

    Science.gov (United States)

    Corson, Yves; Verrier, Nadège

    2007-03-01

    The effects of mood on false memories have not been studied systematically until recently. Some results seem to indicate that negative mood may reduce false recall and thus suggest an influence of emotional valence on false memory. The present research tested the effects of both valence and arousal on recall and recognition and indicates that the effect is actually due to arousal. In fact, whether participants' mood is positive, negative, or neutral, false memories are significantly more frequent under conditions of high arousal than under conditions of low arousal.

  7. How does negative emotion cause false memories?

    Science.gov (United States)

    Brainerd, C J; Stein, L M; Silveira, R A; Rohenkohl, G; Reyna, V F

    2008-09-01

    Remembering negative events can stimulate high levels of false memory, relative to remembering neutral events. In experiments in which the emotional valence of encoded materials was manipulated with their arousal levels controlled, valence produced a continuum of memory falsification. Falsification was highest for negative materials, intermediate for neutral materials, and lowest for positive materials. Conjoint-recognition analysis produced a simple process-level explanation: As one progresses from positive to neutral to negative valence, false memory increases because (a) the perceived meaning resemblance between false and true items increases and (b) subjects are less able to use verbatim memories of true items to suppress errors.

  8. False memories, but not false beliefs, affect implicit attitudes for food preferences.

    Science.gov (United States)

    Howe, David; Anderson, Rachel J; Dewhurst, Stephen A

    2017-09-01

    Previous studies have found that false memories and false beliefs of childhood experiences can have attitudinal consequences. Previous studies have, however, focused exclusively on explicit attitude measures without exploring whether implicit attitudes are similarly affected. Using a false feedback/imagination inflation paradigm, false memories and beliefs of enjoying a certain food as a child were elicited in participants, and their effects were assessed using both explicit attitude measures (self-report questionnaires) and implicit measures (a Single-Target Implicit Association Test). Positive changes in explicit attitudes were observed both in participants with false memories and participants with false beliefs. In contrast, only participants with false memories exhibited more positive implicit attitudes. The findings are discussed in terms of theories of explicit and implicit attitudes. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The semantics of emotion in false memory.

    Science.gov (United States)

    Brainerd, C J; Bookbinder, S H

    2018-03-26

    The emotional valence of target information has been a centerpiece of recent false memory research, but in most experiments, it has been confounded with emotional arousal. We sought to clarify the results of such research by identifying a shared mathematical relation between valence and arousal ratings in commonly administered normed materials. That relation was then used to (a) decide whether arousal as well as valence influences false memory when they are confounded and to (b) determine whether semantic properties that are known to affect false memory covary with valence and arousal ratings. In Study 1, we identified a quadratic relation between valence and arousal ratings of words and pictures that has 2 key properties: Arousal increases more rapidly as function of negative valence than positive valence, and hence, a given level of negative valence is more arousing than the same level of positive valence. This quadratic function predicts that if arousal as well as valence affects false memory when they are confounded, false memory data must have certain fine-grained properties. In Study 2, those properties were absent from norming data for the Cornell-Cortland Emotional Word Lists, indicating that valence but not arousal affects false memory in those norms. In Study 3, we tested fuzzy-trace theory's explanation of that pattern: that valence ratings are positively related to semantic properties that are known to increase false memory, but arousal ratings are not. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  10. Translocations affecting human immunoglobulin heavy chain locus

    Directory of Open Access Journals (Sweden)

    Sklyar I. V.

    2014-03-01

    Full Text Available Translocations involving human immunoglobulin heavy chain (IGH locus are implicated in different leukaemias and lymphomas, including multiple myeloma, mantle cell lymphoma, Burkitt’s lymphoma and diffuse large B cell lymphoma. We have analysed published data and identified eleven breakpoint cluster regions (bcr related to these cancers within the IgH locus. These ~1 kbp bcrs are specific for one or several types of blood cancer. Our findings could help devise PCR-based assays to detect cancer-related translocations, to identify the mechanisms of translocations and to help in the research of potential translocation partners of the immunoglobulin locus at different stages of B-cell differentiation.

  11. False memories for aggressive acts.

    Science.gov (United States)

    Laney, Cara; Takarangi, Melanie K T

    2013-06-01

    Can people develop false memories for committing aggressive acts? How does this process compare to developing false memories for victimhood? In the current research we used a simple false feedback procedure to implant false memories for committing aggressive acts (causing a black eye or spreading malicious gossip) or for victimhood (receiving a black eye). We then compared these false memories to other subjects' true memories for equivalent events. False aggressive memories were all too easy to implant, particularly in the minds of individuals with a proclivity towards aggression. Once implanted, the false memories were indistinguishable from true memories for the same events, on several dimensions, including emotional content. Implications for aggression-related memory more generally as well as false confessions are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Facilitated subcutaneous immunoglobulin administration (fSCIg)

    DEFF Research Database (Denmark)

    Blau, Igor-Wolfgang; Conlon, Niall; Petermann, Robert

    2016-01-01

    and diverse medical needs that treatments for SID management should strive to meet. In this special report, we study the opportunities provided by facilitated subcutaneous immunoglobulin administration (fSCIg) to treat patients for whom the conventional routes (intravenous and subcutaneous) are sub...

  13. Ancient Phylogenetic Beginnings of Immunoglobulin Hypermutation

    Czech Academy of Sciences Publication Activity Database

    Kubrycht, J.; Sigler, Karel; Růžička, Michal; Souček, P.; Borecký, J.; Ježek, Petr

    2006-01-01

    Roč. 63, - (2006), s. 691-706 ISSN 0022-2844 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50110509 Keywords : immunoglobulin * hypermutation * antigen Subject RIV: EE - Microbiology, Virology Impact factor: 2.767, year: 2006

  14. The Immunobiology of Immunoglobulin G4

    NARCIS (Netherlands)

    Lighaam, Laura C.; Rispens, Theo

    2016-01-01

    Human immunoglobulin G4 (IgG4) antibodies are in many ways unusual. In this review, an overview is given of the structural and functional aspects of IgG4 antibodies, the consequences of IgG4 antibody formation in various disease settings, and the factors involved in the regulation of IgG4 responses.

  15. Immunoglobulins and their fragments on solid surfaces

    NARCIS (Netherlands)

    Buijs, J.A.G.

    1995-01-01

    Summary

    Adsorption of immunoglobulin G (IgG) is a common step in the production of immunological tests and biosensors. The use of IgG in these applications stems from its ability to specifically bind all kinds of molecules (antigens). In these tests the IgG

  16. [Production, specificity and structure of immunoglobulins].

    Science.gov (United States)

    Goujard, C; Delfraissy, J F

    1991-03-21

    Immunoglobulin is a key factor of the immune response resulting from B-cell activation and associated with T-cell stimulation. Because of its structure, this antibody has a dual function: it specifically recognizes the inducer antigen in the variable region and eliminates it by a constant portion which is responsible for effector properties. Surface immunoglobulin, therefore, is the B-cell antigen receptor; it differs from the T-cell receptor in that it recognizes the antigen unbound to the major istocompatibility complex; binding the antigen results in direct signal transduction first in the cytoplasm, then in the nucleus. This receptor can be secreted in the body: it is made up of circulating immunoglobulins. Human immunoglobulins are divided into 5 classes, each of them with its own response kinetics, distribution and functions. The variability of the antibody response accounts for a genetic organization involving numerous genes which may be associated with each other, or mutate, or recombine during maturation of the lymphocytes. Altogether, this system has a theoretical capacity of response to three hundred million different antigens.

  17. False positive diagnosis of malignancy in a case of cryptogenic organising pneumonia presenting as a pulmonary mass with mediastinal nodes detected on fluorodeoxyglucose-positron emission tomography: a case report

    Science.gov (United States)

    2009-01-01

    Introduction We report the case of a patient with positive findings on a lung emission tomography/computed tomography (PET/CT) scan, with possible contra lateral mediastinal involvement, which strongly suggested an inoperable lung carcinoma. The lung mass proved to be a cryptogenic organising pneumonia. While the latter has previously been shown to be PET/CT positive, mediastinal involvement simulating malignant spread has not been previously reported. Case presentation A 50-year-old Caucasian woman presented with a history of unproductive cough and was found to have a mass in the right upper lobe as shown on chest X-ray and a computed tomography scan. A subsequent PET/CT scan showed strong uptake in the right upper lobe (maximum standard uptake values (SUVmax) 9.6) with increased uptake in the adjacent mediastinum and contralateral mediastinal nodes. Surgical resection and mediastinoscopy revealed cryptogenic organising pneumonia, with enlarged reactive mediastinal lymph nodes. Conclusion The case illustrates the limits of PET/CT scanning as a diagnostic tool, and emphasizes the importance of obtaining histological confirmation of malignant diseases whenever possible. PMID:19946541

  18. Serum immunoglobulin E and immunoglobulin G reactivity to Agaricus bisporus proteins in mushroom cultivation workers.

    Science.gov (United States)

    Khakzad, Z; Hedayati, M T; Mahdian, S; Mayahi, S

    2015-06-01

    Although molds are regarded as the main fungal allergen sources, evidence indicates that spores of Basidiomycota including Agaricus bisporus ( A. bisporus ) can be also found at high concentrations in the environment and may cause as many respiratory allergies as molds. The aim of the present study was to evaluate specific immunoglobulin E (IgE) and immunoglobulin G (IgG) antibodies against A. bisporus via immunoblotting technique in individuals working at mushroom cultivation centers. In this study, 72 workers involved in the cultivation and harvest of button mushrooms were enrolled. For the analysis of serum IgE and IgG, A. bisporus grown in Sabouraud dextrose broth was harvested and ruptured by liquid nitrogen and glass beads. The obtained sample was centrifuged and the supernatant was collected as "crude extract" (CE). CE was separated via Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The separated proteins were transferred to a nitrocellulose filter and the bands responsive to IgE and IgG were identified by anti-human conjugated antibodies. All participants were screened in terms of total IgE level. Among 72 workers, 18 (25%) had a total IgE level higher than 188 IU/mL. In SDS-PAGE, the CE of A. bisporus showed 23 different protein bands with a molecular weight range of 13-80 kDa. The sera of 23.6% and 55.5% of participants showed positive response, with specific IgE and IgG antibodies against A. bisporus in the blot, respectively. The bands with molecular weights of 62 and 68 kDa were the most reactive protein components of A. bisporus to specific IgE antibodies. Moreover, bands with molecular weights of 57 and 62 kDa showed the highest reactivity to IgG, respectively. Also, 62 and 68 kDa components were the most reactive bands with both specific IgG and IgE antibodies. The obtained findings revealed that A. bisporus has different allergens and antigens, which contribute to its potential as an aeroallergen in hypersensitivity

  19. Myositis ossificans: a false positive of malignancy in PET - CT F.D.G. and in osseous scintigraphy with HMDP {sup 99}Tc;La myosite ossifiante: un faux positif de malignite en TEP-TDM FDG et en scintigraphie osseuse au HMDP Tc99

    Energy Technology Data Exchange (ETDEWEB)

    Hassler, S.; Bourahla, K. [CLCC Paul-Strauss, Service de medecine nucleaire, 67 - Strasbourg (France)

    2010-05-15

    Myositis ossificans is a difficult differential diagnosis and a false positive for malignancy in both {sup 99m}Tc H.M.D.P. (hydroxy-methylene diphosphonate) scintigraphy and in exploration PET-F.D.G. This hypothesis should be mentioned in case of young patients, despite the unusual scintigraphic appearance in a benign process. (N.C.)

  20. Multidisciplinary team review of best practices for collection and handling of blood cultures to determine effective interventions for increasing the yield of true-positive bacteremias, reducing contamination, and eliminating false-positive central line-associated bloodstream infections.

    Science.gov (United States)

    Garcia, Robert A; Spitzer, Eric D; Beaudry, Josephine; Beck, Cindy; Diblasi, Regina; Gilleeny-Blabac, Michelle; Haugaard, Carol; Heuschneider, Stacy; Kranz, Barbara P; McLean, Karen; Morales, Katherine L; Owens, Susan; Paciella, Mary E; Torregrosa, Edwin

    2015-11-01

    A literature search was conducted using keywords for articles published in English from January 1990 to March 2015. Using criteria related to blood culture collection and handling, the search yielded 101 articles. References used also included Microbiology Laboratory standards, guidelines, and textbook information. The literature identified diverse and complex issues surrounding blood culture practices, including the impact of false-positive results, laboratory definition of contamination, effect on central line-associated bloodstream infection (CLABSI) reporting, indications for collecting blood cultures, drawing from venipuncture sites versus intravascular catheters, selection of antiseptics, use of needleless connectors, inoculation of blood culture bottles, and optimizing program management in emergency departments, education, and implementation of bundled practice initiatives. Hospitals should optimize best practice in the collection, handling, and management of blood culture specimens, an often overlooked but essential component in providing optimal care of patients in all settings and populations, reducing financial burdens, and increasing the accuracy of reportable CLABSI. Although universal concepts exist in blood culture practices, some issues require further research to determine benefit. Institutions undertaking a review of their blood culture programs are encouraged to use a checklist that addresses elements that encompass the research contained in this review. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  1. False Memories for Affective Information in Schizophrenia.

    Science.gov (United States)

    Fairfield, Beth; Altamura, Mario; Padalino, Flavia A; Balzotti, Angela; Di Domenico, Alberto; Mammarella, Nicola

    2016-01-01

    Studies have shown a direct link between memory for emotionally salient experiences and false memories. In particular, emotionally arousing material of negative and positive valence enhanced reality monitoring compared to neutral material since emotional stimuli can be encoded with more contextual details and thereby facilitate the distinction between presented and imagined stimuli. Individuals with schizophrenia appear to be impaired in both reality monitoring and memory for emotional experiences. However, the relationship between the emotionality of the to-be-remembered material and false memory occurrence has not yet been studied. In this study, 24 patients and 24 healthy adults completed a false memory task with everyday episodes composed of 12 photographs that depicted positive, negative, or neutral outcomes. Results showed how patients with schizophrenia made a higher number of false memories than normal controls ( p  false memories ( p  > 0.05) resulting from erroneous inferences but did interact with plausible, script consistent errors in patients (i.e., neutral episodes yielded a higher degree of errors than positive and negative episodes). Affective information reduces the probability of generating causal errors in healthy adults but not in patients suggesting that emotional memory impairments may contribute to deficits in reality monitoring in schizophrenia when affective information is involved.

  2. False Memories for Affective Information in Schizophrenia

    Science.gov (United States)

    Fairfield, Beth; Altamura, Mario; Padalino, Flavia A.; Balzotti, Angela; Di Domenico, Alberto; Mammarella, Nicola

    2016-01-01

    Studies have shown a direct link between memory for emotionally salient experiences and false memories. In particular, emotionally arousing material of negative and positive valence enhanced reality monitoring compared to neutral material since emotional stimuli can be encoded with more contextual details and thereby facilitate the distinction between presented and imagined stimuli. Individuals with schizophrenia appear to be impaired in both reality monitoring and memory for emotional experiences. However, the relationship between the emotionality of the to-be-remembered material and false memory occurrence has not yet been studied. In this study, 24 patients and 24 healthy adults completed a false memory task with everyday episodes composed of 12 photographs that depicted positive, negative, or neutral outcomes. Results showed how patients with schizophrenia made a higher number of false memories than normal controls (p false memories (p > 0.05) resulting from erroneous inferences but did interact with plausible, script consistent errors in patients (i.e., neutral episodes yielded a higher degree of errors than positive and negative episodes). Affective information reduces the probability of generating causal errors in healthy adults but not in patients suggesting that emotional memory impairments may contribute to deficits in reality monitoring in schizophrenia when affective information is involved. PMID:27965600

  3. The influence of the noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) resection diagnosis on the false-positive thyroid cytology rate relates to quality assurance thresholds and the application of NIFTP criteria.

    Science.gov (United States)

    Ohori, N Paul; Wolfe, Jenna; Carty, Sally E; Yip, Linwah; LeBeau, Shane O; Berg, Aaron N; Schoedel, Karen E; Nikiforov, Yuri E; Seethala, Raja R

    2017-09-01

    Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a newly defined entity and recent studies have suggested a decrease of a few percentage points in the rate of malignancy (ROM) for the positive-for-malignancy (PFM) cytology category as a result of NIFTP implementation. However, the distinction between a diagnosis of PFM and one of suspicious for malignancy (SFM) may depend on a variety of factors. In the current study, the authors investigated the ROM for the PFM and SFM diagnoses before and after histologic NIFTP reclassification. Cytology cases with PFM and SFM diagnoses and subsequent surgical resection specimens were searched in the files of the study institution from September 2008 to September 2016. The surgical pathology cases of noninvasive encapsulated follicular variant of papillary thyroid carcinoma were reexamined to determine whether they qualified for NIFTP. The distinct ROMs for the PFM and SFM cases were calculated accordingly. The authors' search identified 338 cases of PFM and 139 cases of SFM with a resection outcome. Before NIFTP reclassification, the PFM cases had a ROM of 99.4%; after NIFTP reclassification, the ROM was 99.1% (P = .6861). The ROM of the SFM cases decreased from 75.5% to 66.9% with NIFTP reclassification (P = .1402). One case in the PFM group and 6 cases in the SFM group could not be verified due to insufficient sampling. In the current large series, NIFTP reclassification did not appear to significantly alter the high ROM for the PFM diagnosis. The authors attribute this finding to a strict quality assurance policy, an emphasis on key cytologic criteria, and systematic application of the NIFTP criteria to follicular-patterned lesions. Cancer Cytopathol 2017;125:692-700. © 2017 American Cancer Society. © 2017 American Cancer Society.

  4. Reduced False Memory after Sleep

    Science.gov (United States)

    Fenn, Kimberly M.; Gallo, David A.; Margoliash, Daniel; Roediger, Henry L., III; Nusbaum, Howard C.

    2009-01-01

    Several studies have shown that sleep contributes to the successful maintenance of previously encoded information. This research has focused exclusively on memory for studied events, as opposed to false memories. Here we report three experiments showing that sleep reduces false memories in the Deese-Roediger-McDermott (DRM) memory illusion. False…

  5. Immunoglobulins and C3 in the P. brasiliensis granuloma

    Directory of Open Access Journals (Sweden)

    Lilian M. V. Biagioni

    1987-04-01

    Full Text Available The experimental model of paracoccidioidomycosis induced in mice by the intravenous injection of yeast-forms of P. brasiliensis (Bt2 strain; 1 x 10(6 viable fungi/animal was used to evaluate sequentially 2, 4, 8, 16 and 20 weeks after inoculation: 1. The presence of immunoglobulins and C3 in the pulmonary granuloma-ta, by direct immunofluorescence; 2. The humoral (immunodiffusion test and the cellular (footpad sweeling test immune response; 3. The histopathology of lesions. The cell-immune response was positive since week 2, showing a transitory depression at week 16. Specific antibodies were first detected at week 4 and peaked at week 16. At histology, epithelioid granulomas with numerous fungi and polymorphonuclear agreggates were seen. The lungs showed progressive involvement up to week 16, with little decrease at week 20. From week 2 on, there were deposits of IgG and C3 around fungal walls within the granulomas and IgG stained cells among the mononuclear cell peripheral halo. Interstitital immunoglobulins and C3 deposits in the granulomas were not letected. IgG and C3 seen to play an early an important role in. the host defenses against P. brasiliensis by possibly cooperating in the killing of parasites and blocking the antigenic diffusion.

  6. Unique thermal record in False Bay

    CSIR Research Space (South Africa)

    Grundlingh, ML

    1993-10-01

    Full Text Available Over the past decade False Bay has assumed a prime position in terms of research in to large South African bays. This is manifested by investigations that cover flow conditions modelling, thermal structure, management, biology and nutrients, geology...

  7. Distance Sensitive Bloom Filters Without False Negatives

    DEFF Research Database (Denmark)

    Goswami, Mayank; Pagh, Rasmus; Silvestri, Francesco

    2017-01-01

    A Bloom filter is a widely used data-structure for representing a set S and answering queries of the form “Is x in S?”. By allowing some false positive answers (saying ‘yes’ when the answer is in fact ‘no’) Bloom filters use space significantly below what is required for storing S. In the distanc...

  8. Serum immunoglobulin levels predict fibrosis in patients with non-alcoholic fatty liver disease.

    Science.gov (United States)

    McPherson, Stuart; Henderson, Elsbeth; Burt, Alastair D; Day, Christopher P; Anstee, Quentin M

    2014-05-01

    A third of the population are estimated to have NAFLD of varying severity. Serum immunoglobulins are frequently elevated in patients with chronic liver disease, but little is known about serum immunoglobulin levels in patients with NAFLD. Aim of this study was to evaluate serum immunoglobulin levels (IgA, IgG, and IgM) in a large cohort of patients with biopsy-proven NAFLD and determine if immunoglobulin levels are associated with clinical or histological features. Patients seen in a tertiary fatty liver clinic between 1999 and 2009 were included. Liver biopsies were assessed using the Kleiner score. Immunoglobulin levels and other blood tests were taken at time of biopsy. 285 patients (110 simple steatosis and 175 NASH) had serum immunoglobulins measured within 6months of liver biopsy. 130 (46%) patients had elevated (>1× upper limit of normal) serum IgA levels, 28 (10%) patients had elevated IgG and 22 (8%) raised IgM. Serum IgA levels were elevated more frequently in patients with NASH compared with subjects with simple steatosis (55% vs. 31%, pliver fibrosis (Kleiner stage 3-4). There was a significant positive association between serum IgA levels and the stage of fibrosis (pfibrosis following multivariate analysis. A model constructed from these independent predictors accurately predicted advanced fibrosis (AUROC 0.87). The serum IgA level was frequently elevated in patients with NAFLD and was an independent predictor of advanced fibrosis. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  9. Intravenous immunoglobulin and Alzheimer's disease immunotherapy.

    Science.gov (United States)

    Solomon, Beka

    2007-02-01

    Amyloid-beta peptide (Abeta) contributes to the acute progression of Alzheimer's disease (AD) and has become the main target for therapeutics. Active immunization with Abeta in individuals with AD has been efficacious; however, some patients developed side effects, possibly related to an autoimmune response. Evidence that intravenous immunoglobulin (IVIg), an FDA-approved purified immunoglobulin fraction from normal human donor blood, shows promise of passive immunotherapy for AD is reviewed. Investigations into the molecular effects of IVIg on Abeta clearance, using the BV-2 cellular microglia line, demonstrate that IVIg dissolves Abeta fibrils in vitro, increases cellular tolerance to Abeta, enhances microglial migration toward Abeta deposits, and mediates phagocytosis of Abeta. Preliminary clinical results indicate that IVIg, which contains natural antibodies against the Abeta, warrants further study into its potential to deliver a controlled immune attack on the peptide, avoiding the immune toxicities that have had a negative impact on the first clinical trials of vaccine against Abeta.

  10. Neuromyelitis Optica Immunoglobulin G in a Child

    OpenAIRE

    Hudson, Lynsee A.; Bernard, Timothy J.; Tseng, Brian S.; Miller, Bradford R.; Corboy, John R.

    2006-01-01

    Neuromyelitis optica or Devic’s syndrome is an uncommon demyelinating disorder that preferentially attacks the spinal cord and optic nerves. Although it is well described in adults, childhood neuromyelitis optica has rarely been reported in the literature and is frequently misdiagnosed as severe multiple sclerosis. Recently, a serum immunoglobulin G test for neuromyelitis optica has become available which may clarify and accelerate the diagnosis. This report describes a child with recurrent m...

  11. Evaluation of a Brix refractometer to estimate serum immunoglobulin G concentration in neonatal dairy calves.

    Science.gov (United States)

    Deelen, S M; Ollivett, T L; Haines, D M; Leslie, K E

    2014-01-01

    The objective of this study was to evaluate the utility of a digital Brix refractometer for the assessment of success of passive transfer of maternal immunoglobulin compared with the measurement of serum total protein (STP) by refractometry. Blood samples (n = 400) were collected from calves at 3 to 6d of age. Serum IgG concentration was determined by radial immunodiffusion (RID), and STP and percentage Brix (%Brix) were determined using a digital refractometer. The mean IgG concentration was 24.1g/L [standard deviation (SD) ± 10.0] with a range from 2.1 to 59.1g/L. The mean STP concentration was 6.0 g/dL (SD ± 0.8) with a range from 4.4 to 8.8 g/dL. The mean %Brix concentration was 9.2% (SD ± 0.9) with a range of 7.3 to 12.4%. Brix percentage was highly correlated with IgG (r = 0.93). Test characteristics were calculated to assess failure of passive transfer (FPT; serum IgG <10 g/L). The sensitivity and specificity of STP at 5.5 g/dL were 76.3 and 94.4%, respectively. A receiver operating characteristic curve was created to plot the true positive rate against the false positive rate for consecutive %Brix values. The optimal combination of sensitivity (88.9%) and specificity (88.9%) was at 8.4% Brix. Serum total protein was also positively correlated with %Brix (r = 1.00) and IgG (r = 0.93). Dairy producers can successfully monitor their colostrum management and the overall success of passive transfer using a digital Brix refractometer to estimate IgG concentration of colostrum and calf serum. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. False memories for affective information in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Beth Fairfield

    2016-11-01

    Full Text Available Studies have shown a direct link between memory for emotionally salient experiences and false memories. In particular, emotionally arousing material of negative and positive valence enhanced reality monitoring compared to neutral material since emotional stimuli can be encoded with more contextual details and thereby facilitate the distinction between presented and imagined stimuli. Individuals with schizophrenia appear to be impaired in both reality monitoring and memory for emotional experiences. However, the relationship between the emotionality of the-to-be-remembered material and false memory occurrence has not yet been studied. In this study, twenty-four patients and twenty-four healthy adults completed a false memory task with everyday episodes composed of 12 photographs that depicted positive, negative or neutral outcomes. Results showed how patients with schizophrenia made a higher number of false memories than normal controls (p0.05 resulting from erroneous inferences but did interact with plausible, script consistent errors in patients (i.e. neutral episodes yielded a higher degree of errors than positive and negative episodes. Affective information reduces the probability of generating causal errors in healthy adults but not in patients suggesting that emotional memory impairments may contribute to deficits in reality monitoring in schizophrenia when affective information is involved.

  13. A Positive Emotional Bias in Confabulatory False Beliefs about Place

    Science.gov (United States)

    Turnbull, Oliver H.; Berry, Helen; Evans, Cathryn E.Y.

    2004-01-01

    Some neurological patients with medial frontal lesions exhibit striking confabulations. Most accounts of the cause of confabulations are cognitive, though the literature has produced anecdotal suggestions that confabulations may not be emotionally neutral, having a ("wish-fulfillment") bias that shapes the patient's perception of reality in a more…

  14. Towards "Zero" False Positive in Structural Health Monitoring

    National Research Council Canada - National Science Library

    Chiu, Wing K; Chang, F. K; Tian, Daniel T

    2007-01-01

    Structural Health Monitoring (SHM) is one aspect of a revolution based on the use of Smart Materials and Structures technologies that have the potential to provide major gains in structural performance and cost-efficient life management...

  15. Detection of Biological False Positive Syphilis Serum Reactions ...

    African Journals Online (AJOL)

    A comparative evaluation of reagin tests (Wassermann, VDRL, RPR) and fluorescent treponema antibody absorption tests (FTA-ABS) performed on blood specimens from 5 271 persons (2 493 pregnant women, 1 130 apparently healthy prospective employees, 1 345 newborn babies and 303 leprosy patients) showed that ...

  16. True photographs and false memories.

    Science.gov (United States)

    Lindsay, D Stephen; Hagen, Lisa; Read, J Don; Wade, Kimberley A; Garry, Maryanne

    2004-03-01

    Some trauma-memory-oriented psychotherapists advise clients to review old family photo albums to cue suspected "repressed" memories of childhood sexual abuse. Old photos might cue long-forgotten memories, but when combined with other suggestive influences they might also contribute to false memories. We asked 45 undergraduates to work at remembering three school-related childhood events (two true events provided by parents and one pseudoevent). By random assignment, 23 subjects were also given their school classes' group photos from the years of the to-be-recalled events as memory cues. As predicted, the rate of false-memory reports was dramatically higher in the photo condition than in the no-photo condition. Indeed, the rate of false-memory reports in the photo condition was substantially higher than the rate in any previously published study.

  17. Hydrometer test for estimation of immunoglobulin concentration in bovine colostrum.

    Science.gov (United States)

    Fleenor, W A; Stott, G H

    1980-06-01

    A practical field method for measuring immunoglobulin concentration in bovine colostrum has been developed from the linear relationship between colostral specific gravity and immunoglobulin concentration. Fourteen colostrums were collected within 24 h postpartum from nursed and unnursed cows and were assayed for specific gravity and major colostral constituents. Additionally, 15 colostrums were collected immediately postpartum prior to suckling and assayed for specific gravity and immunoglobulin concentration. Regression analysis provided an equation to estimate colostral immunoglobulin concentration from the specific gravity of fresh whole colostrum. From this, a colostrometer was developed for practical field use.

  18. Underpowered samples, false negatives, and unconscious learning.

    Science.gov (United States)

    Vadillo, Miguel A; Konstantinidis, Emmanouil; Shanks, David R

    2016-02-01

    The scientific community has witnessed growing concern about the high rate of false positives and unreliable results within the psychological literature, but the harmful impact of false negatives has been largely ignored. False negatives are particularly concerning in research areas where demonstrating the absence of an effect is crucial, such as studies of unconscious or implicit processing. Research on implicit processes seeks evidence of above-chance performance on some implicit behavioral measure at the same time as chance-level performance (that is, a null result) on an explicit measure of awareness. A systematic review of 73 studies of contextual cuing, a popular implicit learning paradigm, involving 181 statistical analyses of awareness tests, reveals how underpowered studies can lead to failure to reject a false null hypothesis. Among the studies that reported sufficient information, the meta-analytic effect size across awareness tests was d z = 0.31 (95 % CI 0.24-0.37), showing that participants' learning in these experiments was conscious. The unusually large number of positive results in this literature cannot be explained by selective publication. Instead, our analyses demonstrate that these tests are typically insensitive and underpowered to detect medium to small, but true, effects in awareness tests. These findings challenge a widespread and theoretically important claim about the extent of unconscious human cognition.

  19. Sleep loss produces false memories.

    Directory of Open Access Journals (Sweden)

    Susanne Diekelmann

    Full Text Available People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal",..., lacking the strongest common associate or theme word (here: "black". Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss.

  20. Evolutionary Psychology and False Confession

    Science.gov (United States)

    Bering, Jesse M.; Shackelford, Todd K.

    2005-01-01

    This paper presents comments on Kassin's review, (see record 2005-03019-002) of the psychology of false confessions. The authors note that Kassin's review makes a compelling argument for the need for legal reform in police interrogation practices. Because his work strikes at the heart of the American criminal justice system--its fairness--the…

  1. Screening for congenital toxoplasmosis: accuracy of immunoglobulin M and immunoglobulin A tests after birth

    DEFF Research Database (Denmark)

    Gilbert, Ruth E; Thalib, Lukman; Tan, Hooi Kuan

    2007-01-01

    OBJECTIVES: To determine the accuracy of postnatal screening for toxoplasma-specific immunoglobulin (Ig) M and IgA. SETTING: Ten centres in three European countries. METHODS: We compared results of the first postnatal IgM or IgA test in infants with infected mothers identified by prenatal screeni...

  2. Immunoglobulin therapy for enteroviral meningitides in children

    Directory of Open Access Journals (Sweden)

    O. G. Kimirilova

    2016-01-01

    Full Text Available The authors give the material of their own observations on the clinical and laboratory efficacy of the Russian intravenous immunoglobulin Gabriglobin for the treatment of enteroviral meningitides in children.The performed trials indicated that the use of Gabriglobin in the combination therapy of severe enteroviral meningitides in children reduced the duration of intoxication, global cerebral symptoms, meningeal syndrome, the time of cerebrospinal fluid sanitation by 1,5 times, and that of in-hospital treatment by 5,8±1,8 days as compared to those who received conventional basic therapy.

  3. Working memory affects false memory production for emotional events.

    Science.gov (United States)

    Mirandola, Chiara; Toffalini, Enrico; Ciriello, Alfonso; Cornoldi, Cesare

    2017-01-01

    Whereas a link between working memory (WM) and memory distortions has been demonstrated, its influence on emotional false memories is unclear. In two experiments, a verbal WM task and a false memory paradigm for negative, positive or neutral events were employed. In Experiment 1, we investigated individual differences in verbal WM and found that the interaction between valence and WM predicted false recognition, with negative and positive material protecting high WM individuals against false remembering; the beneficial effect of negative material disappeared in low WM participants. In Experiment 2, we lowered the WM capacity of half of the participants with a double task request, which led to an overall increase in false memories; furthermore, consistent with Experiment 1, the increase in negative false memories was larger than that of neutral or positive ones. It is concluded that WM plays a critical role in determining false memory production, specifically influencing the processing of negative material.

  4. Trust, values and false consensus

    OpenAIRE

    Butler, Jeffrey V.; Giuliano, Paola; Guiso, Luigi

    2012-01-01

    Trust beliefs are heterogeneous across individuals and, at the same time, persistent across generations. We investigate one mechanism yielding these dual patterns: false consensus. In the context of a trust game experiment, we show that individuals extrapolate from their own type when forming trust beliefs about the same pool of potential partners – i.e., more (less) trustworthy individuals form more optimistic (pessimistic) trust beliefs - and that this tendency continues to color trust beli...

  5. Intravenous immunoglobulin in ABO and Rh hemolytic diseases of newborn.

    Science.gov (United States)

    Nasseri, Fatemeh; Mamouri, Gholam A; Babaei, Homa

    2006-12-01

    To evaluate whether the use of intravenous immunoglobulin in newborn infants with isoimmune hemolytic jaundice due to Rh and ABO incompatibility is an effective treatment in reducing the need for exchange transfusion. This study included all direct Coombs' test positive Rh and ABO isoimmunized babies, who admitted in the Neonatal Intensive Care Unit of Ghaem Hospital of Mashhad University of Medical Sciences, Iran, from October 2003 to October 2004. Significant hyperbilirubinemia was defined as rising by >or=0.5 mg/dl per hour. Babies were randomly assigned to received phototherapy with intravenous immunoglobulin (IVIg) 0.5 g/kg over 4 hours, every 12 hours for 3 doses (study group) or phototherapy alone (control group). Exchange transfusion was performed in any group if serum bilirubin exceeded >or=20mg/dl or rose by >or=1mg/dl/h. A total of 34 babies were eligible for this study (17 babies in each group). The number of exchange transfusion, duration of phototherapy and hospitalization days, were significant shorter in the study group versus control group. When we analyzed the outcome results in ABO and Rh hemolytic disease separately, the efficacy of IVIg was significantly better in Rh versus ABO isoimmunization. Late anemia was more common in the IVIg group 11.8% versus 0%, p=0.48. Adverse effects were not observed during IVIg administration. Administration of IVIg to newborns with significant hyperbilirubinemia due to Rh hemolytic disease reduced the need for exchange transfusion but in ABO hemolytic disease there was no significant difference between IVIg and double surface blue light phototherapy.

  6. Intravenous immunoglobulin therapy and systemic lupus erythematosus.

    Science.gov (United States)

    Zandman-Goddard, Gisele; Levy, Yair; Shoenfeld, Yehuda

    2005-12-01

    Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with diverse manifestations. We suggest that intravenous immunoglobulin (IVIg) therapy may be beneficial and safe for various manifestations in SLE. A structured literature search of articles published on the efficacy of IVIg in the treatment of SLE between 1983 and 2005 was conducted. We searched the terms "IVIg," "intravenous immunoglobulin," "lupus," "SLE," and "systemic lupus erythematosus." The various clinical manifestations of SLE that were reported to be successfully treated by IVIg in case reports include autoimmune hemolytic anemia, acquired factor VIII inhibitors, acquired von Willebrand disease, pure red cell aplasia, thrombocytopenia, pancytopenia, myelofibrosis, pneumonitis, pleural effusion, pericarditis, myocarditis, cardiogenic shock, nephritis, end-stage renal disease, encephalitis, neuropsychiatric lupus, psychosis, peripheral neuropathy, polyradiculoneuropathy, and vasculitis. The most extensive experience is with lupus nephritis. There are only a few case series of IVIg use in patients with SLE with various manifestations, in which the response rate to IVIg therapy ranged from 33 to 100%. We suggest that IVIg devoid of sucrose, at a dose of 2 g/kg over a 5-d period given uniformly and at a slow infusion rate in patients without an increased risk for thromboembolic events or renal failure, is a safe and beneficial adjunct therapy for cases of SLE that are resistant to or refuse conventional treatment. The duration of therapy is yet to be established. Controlled trials are warranted.

  7. With sadness comes accuracy; with happiness, false memory: mood and the false memory effect.

    Science.gov (United States)

    Storbeck, Justin; Clore, Gerald L

    2005-10-01

    The Deese-Roediger-McDermott paradigm lures people to produce false memories. Two experiments examined whether induced positive or negative moods would influence this false memory effect. The affect-as-information hypothesis predicts that, on the one hand, positive affective cues experienced as task-relevant feedback encourage relational processing during encoding, which should enhance false memory effects. On the other hand, negative affective cues are hypothesized to encourage item-specific processing at encoding, which should discourage such effects. The results of Experiment 1 are consistent with these predictions: Individuals in negative moods were significantly less likely to show false memory effects than those in positive moods or those whose mood was not manipulated. Experiment 2 introduced inclusion instructions to investigate whether moods had their effects at encoding or retrieval. The results replicated the false memory finding of Experiment 1 and provide evidence that moods influence the accessibility of lures at encoding, rather than influencing monitoring at retrieval of whether lures were actually presented.

  8. Levels of serum immunoglobulins in apparently healthy children and ...

    African Journals Online (AJOL)

    The results also confirm suggestions that levels of some immunoglobulin types seen amongst African adults may have possibly been attained during childhood. Our study could be of value since previous reports in this regard have been relatively scanty especially in this part of Nigeria. Keywords: Immunoglobulin, Immunity ...

  9. Levels of serum immunoglobulins in apparently healthy children and ...

    African Journals Online (AJOL)

    olayemitoyin

    suggestions that levels of some immunoglobulin types seen amongst African adults may have possibly been attained during childhood. Our study could be of value since previous reports in this regard have been relatively scanty especially in this part of Nigeria. Keywords: Immunoglobulin, Immunity, IgA, IgG, IgM.

  10. Immunoglobulin Concentration in Tears of Contact Lens Wearers

    Directory of Open Access Journals (Sweden)

    Rajendra P Maurya

    2014-01-01

    Conclusion: The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation.

  11. INTERACTION OF ALBUMIN AND IMMUNOGLOBULIN G WITH SYNTHETIC HYDROXYAPATITE

    Directory of Open Access Journals (Sweden)

    E. Pylypchuk

    2012-12-01

    Full Text Available It was shown by X-ray phase analysis, IR spectra analysis and MALDI-ToF mass spectrometry methods that interaction of synthetic hydroxyapatite with a solution of immunoglobulin G leads to its partial dissolution due to leaching from the surface of calcium triphosphate which, in our opinion, forms complexes with immunoglobulin G.

  12. Psychoactive drugs and false memory: comparison of dextroamphetamine and delta-9-tetrahydrocannabinol on false recognition

    Science.gov (United States)

    Ballard, Michael E.; Gallo, David A.; de Wit, Harriet

    2014-01-01

    Rationale Several psychoactive drugs are known to influence episodic memory. However, these drugs’ effects on false memory, or the tendency to incorrectly remember nonstudied information, remain poorly understood. Objectives Here, we examined the effects of two commonly used psychoactive drugs, one with memory-enhancing properties (dextroamphetamine; AMP), and another with memory-impairing properties (Δ9-tetrahydrocannabinol; THC), on false memory using the Deese/Roediger–McDermott (DRM) illusion. Methods Two parallel studies were conducted in which healthy volunteers received either AMP (0, 10, and 20 mg) or THC (0, 7.5, and 15 mg) in within-subjects, randomized, double-blind designs. Participants studied DRM word lists under the influence of the drugs, and their recognition memory for the studied words was tested 2 days later, under sober conditions. Results As expected, AMP increased memory of studied words relative to placebo, and THC reduced memory of studied words. Although neither drug significantly affected false memory relative to placebo, AMP increased false memory relative to THC. Across participants, both drugs’ effects on true memory were positively correlated with their effects on false memory. Conclusions Our results indicate that AMP and THC have opposing effects on true memory, and these effects appear to correspond to similar, albeit more subtle, effects on false memory. These findings are consistent with previous research using the DRM illusion and provide further evidence that psychoactive drugs can affect the encoding processes that ultimately result in the creation of false memories. PMID:21647577

  13. Psychoactive drugs and false memory: comparison of dextroamphetamine and δ-9-tetrahydrocannabinol on false recognition.

    Science.gov (United States)

    Ballard, Michael E; Gallo, David A; de Wit, Harriet

    2012-01-01

    Several psychoactive drugs are known to influence episodic memory. However, these drugs' effects on false memory, or the tendency to incorrectly remember nonstudied information, remain poorly understood. Here, we examined the effects of two commonly used psychoactive drugs, one with memory-enhancing properties (dextroamphetamine; AMP), and another with memory-impairing properties (Δ(9)-tetrahydrocannabinol; THC), on false memory using the Deese/Roediger-McDermott (DRM) illusion. Two parallel studies were conducted in which healthy volunteers received either AMP (0, 10, and 20 mg) or THC (0, 7.5, and 15 mg) in within-subjects, randomized, double-blind designs. Participants studied DRM word lists under the influence of the drugs, and their recognition memory for the studied words was tested 2 days later, under sober conditions. As expected, AMP increased memory of studied words relative to placebo, and THC reduced memory of studied words. Although neither drug significantly affected false memory relative to placebo, AMP increased false memory relative to THC. Across participants, both drugs' effects on true memory were positively correlated with their effects on false memory. Our results indicate that AMP and THC have opposing effects on true memory, and these effects appear to correspond to similar, albeit more subtle, effects on false memory. These findings are consistent with previous research using the DRM illusion and provide further evidence that psychoactive drugs can affect the encoding processes that ultimately result in the creation of false memories.

  14. The False Premises and False Promises of the Movement to Privatize Public Education.

    Science.gov (United States)

    Hawley, Willis D.

    1995-01-01

    Argues that the movement to provide parents with financial incentives to send students to private schools will increase the racial, ethnic, and socioeconomic homogeneity of American schools. Six common assumptions about the positive effects of privatizing education are examined and deemed false. Probable costs of tuition vouchers for private…

  15. Nuclear war as false memory

    Directory of Open Access Journals (Sweden)

    John Timberlake

    2014-10-01

    Full Text Available In this paper Timberlake outlines aspects of his creative practice as an artist, explaining his fascination for the ‘fictions of nuclear war’ – a war that never happened and so became the subject of ‘false memory’. Highlighting discontinued historical trajectories, the author shows how the cultural legacy of Britain’s nuclear test programme of the 1950s and ’60s may be explored meaningfully in paintings and photography resulting from his archival research at the Imperial War Museum in London.

  16. False advertising in the greenhouse?

    Science.gov (United States)

    Banse, K.

    1991-12-01

    Most scientists are convinced of the importance of their own research subjects. Broecker [1991] has deplored the temptation, if not the tendency, to go overboard and exaggerate this importance once funding enters the mind. In particular, he alleges inflated or even false claims by biological (and other) oceanographers regarding the relevance of their research to the "greenhouse effect," caused by the anthropogenic enhancement of the atmospheric CO2 content. He writes [Broecker, 1991, p. 191]: "In my estimation, on any list of subjects requiring intense study with regard to the prediction of the consequences of CO2 buildup in the atmosphere, I would place marine biological cycles near the bottom."

  17. Revisiting the False Confession Problem.

    Science.gov (United States)

    Alvarez-Toro, Viviana; Lopez-Morales, Cesar A

    2018-03-01

    Despite the existence of important safeguards in our criminal legal system, innocent suspects often succumb to forceful and deceptive interrogation techniques. Among those over-represented members of the false confessor population are minors, people with cognitive and intellectual disabilities, and those with psychiatric disorders. Some of the confessions made by these at-risk populations can hardly be considered voluntary or reliable, but they are generally admitted at trial, regardless of their prejudicial effect. Forensic psychiatrists should become more involved in the overall process of evaluating confessions, not only testifying in courts, but also assisting policymakers in reforming the interrogation process and influencing the legal process. Thus, forensic psychiatrists may give their expert opinion by providing proper training to police interrogators and examining videotaped interrogations. In addition, forensic experts can be instrumental in contributing to three legal solutions that we propose to the false confession problem: a constitutional approach, an evidence law approach, and a jury instruction approach. Each of these approaches requires forensic psychiatrists to help judges and jurors understand the coercive nature of the interrogation process and its effect on suspects' behavior. © 2018 American Academy of Psychiatry and the Law.

  18. Introducing False EUR and False EUR exchange rates

    Science.gov (United States)

    Ausloos, M.; Ivanova, K.

    2000-10-01

    The Euro ( EUR) is a new currency introduced by the European Community. Its exchange rate is very puzzling. We have invented a false Euro ( FEUR) dating back to 1993 and have derived the exchange rates of the FEUR with respect to currencies not belonging to the EUR, i.e., DKK, CHF, JPY and USD. This allows us to search for correlations between the fluctuations preexisting to the introduction of EUR and present ones in such financial data. The detrended fluctuation analysis ( DFA) statistical method is used. This leads to assume a power-law behavior, i.e., a scaling hypothesis, through an exponent α. The latter has demonstrated its usefulness for the investigations of long-range power-law correlations in several types of financial sequences. Our findings show that the α exponent interestingly characterizes fractional Brownian motion of the currency exchange rates between EUR and DKK over a 25 day interval, and usual Brownian motion otherwise and for the three other investigated exchange rates. We can devise an investment strategy based on the localα technique and obtain appreciable gains for the time being.

  19. Solar urticaria successfully treated with intravenous immunoglobulin.

    LENUS (Irish Health Repository)

    Hughes, R

    2012-02-01

    Idiopathic solar urticaria (SU) is a rare, debilitating photodermatosis, which may be difficult to treat. First-line treatment with antihistamines is effective in mild cases, but remission after phototherapeutic induction of tolerance is often short-lived. Other treatment options include plasma exchange, photopheresis and cyclosporin. We present two cases of severe, idiopathic SU, which were resistant to conventional treatment. Both patients achieved remission after administration of intravenous immunoglobulin (IVIg) and have remained in remission at 13 months and 4 years, respectively. There are only two case reports of successful treatment of solar urticaria with IVIg. In our experience IVIg given at a total dose of 2 g\\/kg over several 5-day courses about a month apart is an effective treatment option for severe idiopathic SU. It is also generally safe, even if certainly subject to significant theoretical risks, such as induction of viral infection or anaphylaxis.

  20. Immunoglobulin G4-Related Disease: An Update

    Directory of Open Access Journals (Sweden)

    Abdullah Al-Mujaini

    2018-03-01

    Full Text Available Immunoglobulin G4-related disease (IgG4-RD is an increasingly recognized immune-mediated condition comprised of a collection of disorders that share specific pathological, serological, and clinical features. IgG4-RD is a fibroinflammatory condition with a tendency to form tumors with inflammatory infiltrate with IgG4 rich plasma cells and elevation of serum IgG4, which may affect virtually every organ and tissue. IgG4-related ophthalmic disease may present as dacryoadenitis, myositis, or involvement of other orbital tissue. Hypophysitis or pachymeningitis may manifest as cranial neuropathies. The diagnosis of IgG4-RD is based on a typical clinical scenario, supportive laboratory test, expected radiological characteristics, and distinct histopathological and immunohistochemical features. Corticosteroids and immunosuppressives form the mainline treatment.

  1. Structural repertoire of immunoglobulin λ light chains

    KAUST Repository

    Chailyan, Anna

    2011-03-01

    The immunoglobulin λ isotype is present in nearly all vertebrates and plays an important role in the human immune system. Despite its importance, few systematic studies have been performed to analyze the structural conformation of its variable regions, contrary to what is the case for κ and heavy chains. We show here that an analysis of the structures of λ chains allows the definition of a discrete set of recurring conformations (canonical structures) of their hypervariable loops and, most importantly, the identification of sequence constraints that can be used to predict their structure. We also show that the structural repertoire of λ chains is different and more varied than that of the κ chains, consistently with the current view of the involvement of the two major light-chain families in complementary strategies of the immune system to ensure a fine tuning between diversity and stability in antigen recognition. © 2011 Wiley-Liss, Inc.

  2. Structural repertoire of immunoglobulin λ light chains

    KAUST Repository

    Chailyan, Anna; Marcatili, Paolo; Cirillo, Davide; Tramontano, Anna

    2011-01-01

    The immunoglobulin λ isotype is present in nearly all vertebrates and plays an important role in the human immune system. Despite its importance, few systematic studies have been performed to analyze the structural conformation of its variable regions, contrary to what is the case for κ and heavy chains. We show here that an analysis of the structures of λ chains allows the definition of a discrete set of recurring conformations (canonical structures) of their hypervariable loops and, most importantly, the identification of sequence constraints that can be used to predict their structure. We also show that the structural repertoire of λ chains is different and more varied than that of the κ chains, consistently with the current view of the involvement of the two major light-chain families in complementary strategies of the immune system to ensure a fine tuning between diversity and stability in antigen recognition. © 2011 Wiley-Liss, Inc.

  3. Bug hunting with false negatives

    NARCIS (Netherlands)

    Calamé, J.R.; Ioustinova, N.; Pol, van de J.C.; Sidorova, N.; Davies, J.; Gibbons, J.

    2007-01-01

    Safe data abstractions are widely used for verification purposes. Positive verification results can be transferred from the abstract to the concrete system. When a property is violated in the abstract system, one still has to check whether a concrete violation scenario exists. However, even when the

  4. Acute Inflammatory Demyelinating Neuropathy : Immunoglobulin And Immune Complex Profile

    Directory of Open Access Journals (Sweden)

    Shripad A

    2003-01-01

    Full Text Available Serum immunoglobulins (IgG, IgA and IgM and immune complexes IgG (IcG were measured in 58 cases of acute inflammatory demyelinating neuropathy, popularly known as Guillian Barre′ syndrome, and in 30 healthy controls using single radial immunodiffusion assay. Immunoglobulin and immune complex levels were significantly elevated in patients as compared to controls. The increased levels of immunoglobulins and immune complexes may contribute to the pathogenesis of the disease and provide rationale for therapeutic plasmapheresis.

  5. Complementarity in false memory illusions.

    Science.gov (United States)

    Brainerd, C J; Reyna, V F

    2018-03-01

    For some years, the DRM illusion has been the most widely studied form of false memory. The consensus theoretical interpretation is that the illusion is a reality reversal, in which certain new words (critical distractors) are remembered as though they are old list words rather than as what they are-new words that are similar to old ones. This reality-reversal interpretation is supported by compelling lines of evidence, but prior experiments are limited by the fact that their memory tests only asked whether test items were old. We removed that limitation by also asking whether test items were new-similar. This more comprehensive methodology revealed that list words and critical distractors are remembered quite differently. Memory for list words is compensatory: They are remembered as old at high rates and remembered as new-similar at very low rates. In contrast, memory for critical distractors is complementary: They are remembered as both old and new-similar at high rates, which means that the DRM procedure induces a complementarity illusion rather than a reality reversal. The conjoint recognition model explains complementarity as a function of three retrieval processes (semantic familiarity, target recollection, and context recollection), and it predicts that complementarity can be driven up or down by varying the mix of those processes. Our experiments generated data on that prediction and introduced a convenient statistic, the complementarity ratio, which measures (a) the level of complementarity in memory performance and (b) whether its direction is reality-consistent or reality-reversed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  6. Immunoglobulin for alloimmune hemolytic disease in neonates.

    Science.gov (United States)

    Zwiers, Carolien; Scheffer-Rath, Mirjam Ea; Lopriore, Enrico; de Haas, Masja; Liley, Helen G

    2018-03-18

    Exchange transfusion and phototherapy have traditionally been used to treat jaundice and avoid the associated neurological complications. Because of the risks and burdens of exchange transfusion, intravenous immunoglobulin (IVIg) has been suggested as an alternative therapy for alloimmune hemolytic disease of the newborn (HDN) to reduce the need for exchange transfusion. To assess the effect and complications of IVIg in newborn infants with alloimmune HDN on the need for and number of exchange transfusions. We performed electronic searches of CENTRAL, PubMed, Embase (Ovid), Web of Science, CINAHL (EBSCOhost), Academic Search Premier, and the trial registers ClinicalTrials.gov and controlled-trials.com in May 2017. We also searched reference lists of included and excluded trials and relevant reviews for further relevant studies. We considered all randomized and quasi-randomized controlled trials of IVIg in the treatment of alloimmune HDN. Trials must have used predefined criteria for the use of IVIg and exchange transfusion therapy to be included. We used the standard methods of Cochrane and its Neonatal Review Group. We assessed studies for inclusion and two review authors independently assessed quality and extracted data. We discussed any differences of opinion to reach consensus. We contacted investigators for additional or missing information. We calculated risk ratio (RR), risk difference (RD) and number needed to treat for an additional beneficial outcome (NNTB) for categorical outcomes. We calculated mean difference (MD) for continuous variables. We used GRADE criteria to assess the risk of bias for major outcomes and to summarize the level of evidence. Nine studies with 658 infants fulfilled the inclusion criteria. Term and preterm infants with Rh or ABO (or both) incompatibility were included. The use of exchange transfusion decreased significantly in the immunoglobulin treated group (typical RR 0.35, 95% CI 0.25 to 0.49; typical RD -0.22, 95% CI -0.27 to

  7. Hepatitis B immunisation for newborn infants of hepatitis B surface antigen-positive mothers

    DEFF Research Database (Denmark)

    Lee, C; Gong, Yanzhang; Brok, J

    2006-01-01

    Hepatitis B vaccine and hepatitis B immunoglobulin are considered for newborn infants of HBsAg-positive mothers to prevent hepatitis B infection.......Hepatitis B vaccine and hepatitis B immunoglobulin are considered for newborn infants of HBsAg-positive mothers to prevent hepatitis B infection....

  8. Too Good to be False : Nonsignificant Results Revisited

    NARCIS (Netherlands)

    Hartgerink, Chris H J; Wicherts, Jelte M.; Van Assen, M. A. L. M.

    2017-01-01

    Due to its probabilistic nature, Null Hypothesis Significance Testing (NHST) is subject to decision errors. The concern for false positives has overshadowed the concern for false negatives in the recent debates in psychology. This might be unwarranted, since reported statistically nonsignificant

  9. 7(th) International Immunoglobulin Conference: Poster presentations.

    Science.gov (United States)

    Warnatz, K; Ballow, M; Stangel, M; Bril, V

    2014-12-01

    Immunoglobulin (Ig) therapy is the mainstay of treatment for primary antibody deficiency disorders and has proved to be efficacious in specific autoimmune and inflammatory diseases. Additionally, due to the role of Ig in complement activation, it is being used increasingly in solid organ transplantation. Furthermore, Ig is the primary or secondary treatment in some immune-mediated neuropathies such as chronic inflammatory demyelinating polyneuropathy (CIDP) or multifocal motor neuropathy (MMN). This session discusses trends of Ig use in Europe, proposed mechanisms of action, adverse effects and the potential role of Ig therapy in transplantation. Dr Šedivá reported that Ig therapy is available in all European countries, although dosing is not always optimal, due partly to reimbursement plans. Subcutaneous immunoglobulin (SCIg) has become increasingly accessible in recent years; however, the chosen route of administration still varies widely between countries. Dr Berger's presentation on optimization of Ig therapy in neuropathies, and Dr Rojavin's report on a pharmacometric model to determine the serum IgG levels achieved by different dosing regimens in primary antibody deficiency (PAD) patients, led to the challenging concept of using individualized dosing strategies. Dr Klehmet reported on the potential benefit of using antigen-specific T cell responses as a biomarker of IVIg responsiveness in CIDP patients, while Dr von Gunten provided an insight into the mechanisms of action of Ig preparations, suggesting that the immunoregulatory effects of IgG may be mediated by IgG antibodies against glycans. Dr Basta reported on the potential thrombogenic adverse effects associated with Ig therapy. Although these adverse events are rare, further studies are needed to clarify the relationship between Ig replacement and immunomodulatory therapy and these adverse reactions. In transplantation, Dr Carbone described that prophylactic IVIg treatment was found to decrease the

  10. Pattern of intravenous immunoglobulins (IVIG) use in a pediatric ...

    African Journals Online (AJOL)

    Pattern of intravenous immunoglobulins (IVIG) use in a pediatric intensive care facility in a resource limited setting. ... Journal Home > Vol 13, No 2 (2013) > ... Results: The clinical diagnoses included neurology (35%), neonatology (16%), ...

  11. Beneficial use of immunoglobulins in the treatment of Sydenham chorea

    NARCIS (Netherlands)

    T.D. van Immerzeel (Tabitha); R.M. van Gilst (Ruud); N.G. Hartwig (Nico)

    2010-01-01

    textabstractThis double case report indicates that treatment with intravenous immunoglobulins (IVIG) is effective in patients with Sydenham chorea (SC). SC is a rare but impressive clinical manifestation following streptococcal infection. This movement disorder characterised by chorea, emotional

  12. Human placental immunoglobulins show unique re-association ...

    African Journals Online (AJOL)

    Objective: To study re-association pattern of human placental eluate immunoglobulins with acid treated isologous and third party trophoblast derived placental microvesicles. Design: Laboratory based experimentation. Setting: Biological Sciences Department and Discipline for Reproductive Medicine University of ...

  13. Cerebrospinal fluid aquaporin-4-immunoglobulin G disrupts blood brain barrier

    DEFF Research Database (Denmark)

    Asgari, Nasrin; Berg, Carsten Tue; Mørch, Marlene Thorsen

    2015-01-01

    associated with blood-borne horseradish peroxidase leakage indicating blood-brain barrier breakdown. The cerebrospinal fluid aquaporin-4-immunoglobulin G therefore distributes widely in brain to initiate astrocytopathy and blood-brain barrier breakdown....... was evaluated. A distinct distribution pattern of aquaporin-4-immunoglobulin G deposition was observed in the subarachnoid and subpial spaces where vessels penetrate the brain parenchyma, via a paravascular route with intraparenchymal perivascular deposition. Perivascular astrocyte-destructive lesions were...

  14. Purification, characterization and ELISA detection of mink immunoglobulins

    DEFF Research Database (Denmark)

    Martel, Cyril Jean-Marie; Aasted, Bent

    2008-01-01

    the estimated molecular weights of the immunoglobulin gamma, alpha and mu heavy chains were found to be 54 kDa, 69 kDa and 83 kDa respectively. The purities of purified IgG, IgM and IgA were estimated by immunoglobulin class specific ELISAs to be more than 90% for IgG and IgM, and more than 80% for IgA....

  15. Production of immunoglobulins in gingival tissue explant cultures from juvenile periodontitis patients

    International Nuclear Information System (INIS)

    Hall, E.R.; Falkler, W.A. Jr.; Suzuki, J.B.

    1990-01-01

    B lymphocytes and plasma cells are histologically observed in granulomatous periodontal tissues of juvenile periodontitis (JP) patients. Local immune processes may participate in protective or immunopathologic roles in the pathogenesis of this disease. An in vitro explant culture system was utilized to demonstrate the production of immunoglobulins by diseased JP tissues. Immunodiffusion studies using goat anti-human gamma, alpha, or mu chain serum revealed IgG to be the major immunoglobulin present in 92% of the day 1 supernatant fluids (SF) of the 47 JP gingival tissue explant cultures. IgA was present in 15% of the SF; however, no IgM was detected. Staph Protein A isolated 14C-labeled IgG from the SF, when allowed to react with goat anti-human gamma chain serum, formed lines of precipitation. Positive autoradiographs confirmed the biosynthesis of IgG by the explant cultures. The in vitro gingival tissue explant culture system described provides a useful model for the study of localized immunoglobulins produced by diseased tissues of JP patients

  16. Limited number of immunoglobulin VH regions expressed in the mutant rabbit "Alicia".

    Science.gov (United States)

    DiPietro, L A; Short, J A; Zhai, S K; Kelus, A S; Meier, D; Knight, K L

    1990-06-01

    A unique feature of rabbit Ig is the presence of VH region allotypic specificities. In normal rabbits, more than 80% of circulating immunoglobulin molecules bear the VHa allotypic specificities, al, a2 or a3; the remaining 10% to 20% of immunoglobulin molecules lack VHa allotypic specificities and are designated VHa-. A mutant rabbit designated Alicia, in contrast, has predominantly serum immunoglobulin molecules that lack the VHa allotypic specificities (Kelus and Weiss, Proc. Natl. Acad. Sci. USA 1986. 83: 4883). To study the nature and molecular complexity of VHa- molecules, we cloned and determined the nucleotide sequence of seven cDNA prepared from splenic RNA of an Alicia rabbit. Six of the clones appeared to encode VHa- molecules; the framework regions encoded by these clones were remarkably similar to each other, each having an unusual insertion of four amino acids at position 10. This insertion of four amino acids has been seen in only 2 of 54 sequenced rabbit VH genes. The similarity of the sequences of the six VHa- clones to each other and their dissimilarity to most other VH genes leads us to suggest that the VHa- molecules in Alicia rabbits are derived predominantly from one or a small number of very similar VH genes. Such preferential utilization of a small number of VH genes may explain the allelic inheritance of VH allotypes.

  17. Production of immunoglobulins in gingival tissue explant cultures from juvenile periodontitis patients

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.R.; Falkler, W.A. Jr.; Suzuki, J.B. (Univ. of Maryland Dental School, Baltimore (USA))

    1990-10-01

    B lymphocytes and plasma cells are histologically observed in granulomatous periodontal tissues of juvenile periodontitis (JP) patients. Local immune processes may participate in protective or immunopathologic roles in the pathogenesis of this disease. An in vitro explant culture system was utilized to demonstrate the production of immunoglobulins by diseased JP tissues. Immunodiffusion studies using goat anti-human gamma, alpha, or mu chain serum revealed IgG to be the major immunoglobulin present in 92% of the day 1 supernatant fluids (SF) of the 47 JP gingival tissue explant cultures. IgA was present in 15% of the SF; however, no IgM was detected. Staph Protein A isolated 14C-labeled IgG from the SF, when allowed to react with goat anti-human gamma chain serum, formed lines of precipitation. Positive autoradiographs confirmed the biosynthesis of IgG by the explant cultures. The in vitro gingival tissue explant culture system described provides a useful model for the study of localized immunoglobulins produced by diseased tissues of JP patients.

  18. [Identification and production of monoclonal antibody of Siberian tiger's immunoglobulin].

    Science.gov (United States)

    Zhang, Yaonglong; Zhang, Duanling; Zhou, Ming; Xue, Yuan; Hua, Yuping; Ma, Jianzhang

    2010-03-01

    To purify immunoglobulin (Ig) of Siberian Tiger and prepare monoclonal antibody (mAb) against the Ig,which can be used to develop immunological diagnostic kits for diagnosing infectious disease in Siberian Tiger. The Ig of Siberian tigers was purified with saturated ammonium sulfate combined with recombinant Protein G. The C57BL/6 mice were immunized with the purified Ig. Spleno-cytes of the mice immunized were collected and fused with the mouse myeloma cell line (Sp2/0-Ag14). The positive hybridoma clones were selected by ELISA and were identified by western blot. The sandwich ELISA was used to detect immunocompetence of the purified Ig and the mAb. We obtained three mouse hybridoma clones that produced mAbs against Ig of Siberian Tiger. The derived McAbs could recognize Ig heavy chain of Siberian Tiger specifically. The biological activity of the Ig and obtained McAbs also could be identified by detecting the antibody induced by panleukopenia virus (FPV-HLJ) vaccine in Siberian Tiger. The antibody also would be useful for assess the vaccine efficacy against the infectious disease on the Siberian Tiger. Protein G can be used in Ig purification of Siberian Tiger. The obtained McAbs from the hybridoma ADT11 in this study owned strong ability to bind Ig of Siberian Tiger and have a stable immunocompetence. They can be used to develop diagnostic methods for detecting infectious disease in Siberian Tiger and vaccine research.

  19. Immunoglobulin class-switch recombination deficiencies.

    Science.gov (United States)

    Durandy, Anne; Kracker, Sven

    2012-07-30

    Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants in humans. This approach has revealed that T cell-B cell interaction (resulting in CD40-mediated signaling), intrinsic B-cell mechanisms (activation-induced cytidine deaminase-induced DNA damage), and complex DNA repair machineries (including uracil-N-glycosylase and mismatch repair pathways) are all involved in class-switch recombination and SHM. However, several of the mechanisms required for full antibody maturation have yet to be defined. Elucidation of the molecular defects underlying the diverse set of Ig-CSR-Ds is essential for understanding Ig diversification and has prompted better definition of the clinical spectrum of diseases and the development of increasingly accurate diagnostic and therapeutic approaches.

  20. Effects of depressive disorder on false memory for emotional information.

    Science.gov (United States)

    Yeh, Zai-Ting; Hua, Mau-Sun

    2009-01-01

    This study explored with a false memory paradigm whether (1) depressed patients revealed more false memories and (2) whether more negative false than positive false recognition existed in subjects with depressive disorders. Thirty-two patients suffering from a major depressive episode (DSM-IV criteria), and 30 age- and education-matched normal control subjects participated in this study. After the presentation of a list of positive, negative, and neutral association items in the learning phase, subjects were asked to give a yes/no response in the recognition phase. They were also asked to rate 81 recognition items with emotional valence scores. The results revealed more negative false memories in the clinical depression group than in the normal control group; however, we did not find more negative false memories than positive ones in patients. When compared with the normal group, a more conservative response criterion for positive items was evident in patient groups. It was also found that when compared with the normal group, the subjects in the depression group perceived the positive items as less positive. On the basis of present results, it is suggested that depressed subjects judged the emotional information with criteria different from normal individuals, and patients' emotional memory intensity is attenuated by their mood.

  1. Mood-congruent true and false memory: effects of depression.

    Science.gov (United States)

    Howe, Mark L; Malone, Catherine

    2011-02-01

    The Deese/Roediger-McDermott paradigm was used to investigate the effect of depression on true and false recognition. In this experiment true and false recognition was examined across positive, neutral, negative, and depression-relevant lists for individuals with and without a diagnosis of major depressive disorder. Results showed that participants with major depressive disorder falsely recognised significantly more depression-relevant words than non-depressed controls. These findings also parallel recent research using recall instead of recognition and show that there are clear mood congruence effects for depression on false memory performance. © 2011 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business

  2. Il nuovo reato di false comunicazioni sociali

    Directory of Open Access Journals (Sweden)

    Lorenzo Maria Corvucci

    2015-12-01

    Full Text Available The author examines the new offence of false social communication introduced by the Italian law dated 27 may 2015 n.69 in force from 14 June 2015. Considering the modifications added to the new offence of false accounting- basically explained to highlight the novum - the attention is paid on a specific major issue, previously discussed by the fifth section of the Italian Supreme Court competent in this matter after a few months from the moment the new law came in force. The questions applies to the fact whether the fraudulent evidence should remain to be punishable as the new discipline has limited the object of the criminal conduct only to “material relevant facts which are untrue” or to the omission of material relevant facts whose communication is imposed by the law regulating the economic situation, the assets and financial position of the company or of the group to which the company belongs. In this way any reference to the evaluations contained in the text previously in force is eliminated. Omissive conduct is the new definition recalling the two previous rules (art. 2621 and 2622 of the Italian civil code.

  3. A new high molecular weight immunoglobulin class from the carcharhine shark: implications for the properties of the primordial immunoglobulin.

    Science.gov (United States)

    Berstein, R M; Schluter, S F; Shen, S; Marchalonis, J J

    1996-04-16

    All immunoglobulins and T-cell receptors throughout phylogeny share regions of highly conserved amino acid sequence. To identify possible primitive immunoglobulins and immunoglobulin-like molecules, we utilized 3' RACE (rapid amplification of cDNA ends) and a highly conserved constant region consensus amino acid sequence to isolate a new immunoglobulin class from the sandbar shark Carcharhinus plumbeus. The immunoglobulin, termed IgW, in its secreted form consists of 782 amino acids and is expressed in both the thymus and the spleen. The molecule overall most closely resembles mu chains of the skate and human and a new putative antigen binding molecule isolated from the nurse shark (NAR). The full-length IgW chain has a variable region resembling human and shark heavy-chain (VH) sequences and a novel joining segment containing the WGXGT motif characteristic of H chains. However, unlike any other H-chain-type molecule, it contains six constant (C) domains. The first C domain contains the cysteine residue characteristic of C mu1 that would allow dimerization with a light (L) chain. The fourth and sixth domains also contain comparable cysteines that would enable dimerization with other H chains or homodimerization. Comparison of the sequences of IgW V and C domains shows homology greater than that found in comparisons among VH and C mu or VL, or CL thereby suggesting that IgW may retain features of the primordial immunoglobulin in evolution.

  4. High confidence in falsely recognizing prototypical faces.

    Science.gov (United States)

    Sampaio, Cristina; Reinke, Victoria; Mathews, Jeffrey; Swart, Alexandra; Wallinger, Stephen

    2018-06-01

    We applied a metacognitive approach to investigate confidence in recognition of prototypical faces. Participants were presented with sets of faces constructed digitally as deviations from prototype/base faces. Participants were then tested with a simple recognition task (Experiment 1) or a multiple-choice task (Experiment 2) for old and new items plus new prototypes, and they showed a high rate of confident false alarms to the prototypes. Confidence and accuracy relationship in this face recognition paradigm was found to be positive for standard items but negative for the prototypes; thus, it was contingent on the nature of the items used. The data have implications for lineups that employ match-to-suspect strategies.

  5. 19 CFR 111.32 - False information.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false False information. 111.32 Section 111.32 Customs... CUSTOMS BROKERS Duties and Responsibilities of Customs Brokers § 111.32 False information. A broker must... procure the giving of, any false or misleading information or testimony in any matter pending before the...

  6. Immunoglobulin heavy chain exclusion in the shark.

    Directory of Open Access Journals (Sweden)

    Karolina Malecek

    2008-06-01

    Full Text Available The adaptive immune system depends on specific antigen receptors, immunoglobulins (Ig in B lymphocytes and T cell receptors (TCR in T lymphocytes. Adaptive responses to immune challenge are based on the expression of a single species of antigen receptor per cell; and in B cells, this is mediated in part by allelic exclusion at the Ig heavy (H chain locus. How allelic exclusion is regulated is unclear; we considered that sharks, the oldest vertebrates possessing the Ig/TCR-based immune system, would yield insights not previously approachable and reveal the primordial basis of the regulation of allelic exclusion. Sharks have an IgH locus organization consisting of 15-200 independently rearranging miniloci (VH-D1-D2-JH-Cmu, a gene organization that is considered ancestral to the tetrapod and bony fish IgH locus. We found that rearrangement takes place only within a minilocus, and the recombining gene segments are assembled simultaneously and randomly. Only one or few H chain genes were fully rearranged in each shark B cell, whereas the other loci retained their germline configuration. In contrast, most IgH were partially rearranged in every thymocyte (developing T cell examined, but no IgH transcripts were detected. The distinction between B and T cells in their IgH configurations and transcription reveals a heretofore unsuspected chromatin state permissive for rearrangement in precursor lymphocytes, and suggests that controlled limitation of B cell lineage-specific factors mediate regulated rearrangement and allelic exclusion. This regulation may be shared by higher vertebrates in which additional mechanistic and regulatory elements have evolved with their structurally complex IgH locus.

  7. Persistent Graves' hyperthyroidism despite rapid negative conversion of thyroid-stimulating hormone-binding inhibitory immunoglobulin assay results: a case report.

    Science.gov (United States)

    Ohara, Nobumasa; Kaneko, Masanori; Kitazawa, Masaru; Uemura, Yasuyuki; Minagawa, Shinichi; Miyakoshi, Masashi; Kaneko, Kenzo; Kamoi, Kyuzi

    2017-02-06

    Graves' disease is an autoimmune thyroid disorder characterized by hyperthyroidism, and patients exhibit thyroid-stimulating hormone receptor antibody. The major methods of measuring circulating thyroid-stimulating hormone receptor antibody include the thyroid-stimulating hormone-binding inhibitory immunoglobulin assays. Although the diagnostic accuracy of these assays has been improved, a minority of patients with Graves' disease test negative even on second-generation and third-generation thyroid-stimulating hormone-binding inhibitory immunoglobulins. We report a rare case of a thyroid-stimulating hormone-binding inhibitory immunoglobulin-positive patient with Graves' disease who showed rapid lowering of thyroid-stimulating hormone-binding inhibitory immunoglobulin levels following administration of the anti-thyroid drug thiamazole, but still experienced Graves' hyperthyroidism. A 45-year-old Japanese man presented with severe hyperthyroidism (serum free triiodothyronine >25.0 pg/mL; reference range 1.7 to 3.7 pg/mL) and tested weakly positive for thyroid-stimulating hormone-binding inhibitory immunoglobulins on second-generation tests (2.1 IU/L; reference range hyperthyroidism for more than 8 years, requiring 15 mg/day of thiamazole to correct. During that period, he tested negative on all first-generation, second-generation, and third-generation thyroid-stimulating hormone-binding inhibitory immunoglobulin assays, but thyroid scintigraphy revealed diffuse and increased uptake, and thyroid ultrasound and color flow Doppler imaging showed typical findings of Graves' hyperthyroidism. The possible explanations for serial changes in the thyroid-stimulating hormone-binding inhibitory immunoglobulin results in our patient include the presence of thyroid-stimulating hormone receptor antibody, which is bioactive but less reactive on thyroid-stimulating hormone-binding inhibitory immunoglobulin assays, or the effect of reduced levels of circulating thyroid

  8. Serum immunoglobulin G4 levels and Graves' disease phenotype.

    Science.gov (United States)

    Martin, Carmen Sorina; Sirbu, Anca Elena; Betivoiu, Minodora Andreea; Florea, Suzana; Barbu, Carmen Gabriela; Fica, Simona Vasilica

    2017-02-01

    We investigated, at diagnosis, the relationship between serum immunoglobulin G4 levels and the main characteristics of Graves' disease: hyperthyroidism severity, goiter size, presence of active Graves' ophthalmopathy, antithyroid antibodies status, and titer. This prospective study included 80 newly diagnosed Graves' disease patients. The main parameters measured at diagnosis: thyroid-stimulating hormone, free thyroxine, free triiodothyronine, total triiodothyronine, thyroglobulin, antithyroid peroxidase antibodies, anti-thyroglobulin antibodies, thyroid-stimulating hormone receptor antibodies, immunoglobulin G4. In Graves' disease patients, serum immunoglobulin G4 levels were higher than in general population (p = 0.028) and higher in men compared to women (p = 0.002). Only one female patient with intense hypoechoic goiter, high anti-thyroglobulin antibody, and antithyroid peroxidase antibody titers had an elevated serum immunoglobulin G4 level at diagnosis. Patients with immunoglobulin G4 levels above the 75th percentile (>237.52 mg/dl, N = 20) were younger at Graves' ophthalmopathy onset (p 286.28 mg/dl, N = 8) had lower total triiodothyronine values (p = 0.001) than patients with IgG below the 90th percentile. No significant correlations were found between smoking status (p = 0.58), goiter size (p = 0.50), the presence of ophthalmopathy (p = 0.42) or thyroid-stimulating hormone receptor antibody titers (p = 0.45) and the mean value of immunoglobulin G4 levels at diagnosis. Our data suggest that Graves' disease patients with elevated immunoglobulin G4 levels at diagnosis have a phenotype characterized by higher anti-thyroglobulin antibody and antithyroid peroxidase antibody titers, less severe T3 hyperthyroidism, younger age at ophthalmopathy onset and require a shorter duration of the first methimazole treatment cycle.

  9. Motivated reconstruction: The effect of brand commitment on false memories.

    Science.gov (United States)

    Montgomery, Nicole Votolato; Rajagopal, Priyali

    2018-06-01

    Across 5 studies, we examine the effect of prior brand commitment on the creation of false memories about product experience after reading online product reviews. We find that brand commitment and the valence of reviews to which consumers are exposed, interact to affect the incidence of false memories. Thus, highly committed consumers are more susceptible to the creation of false experience memories on exposure to positive versus negative reviews, whereas low commitment consumers exhibit similar levels of false memories in response to both positive and negative reviews. Further, these differences across brand commitment are attenuated when respondents are primed with an accuracy motivation, suggesting that the biasing effects of commitment are likely because of the motivation to defend the committed brand. Finally, we find that differences in false memories subsequently lead to differences in intentions to spread word-of-mouth (e.g., recommend the product to friends), suggesting that the consequences of false product experience memories can be significant for marketers and consumers. Our findings contribute to the literatures in false memory and marketing by documenting a motivated bias in false memories because of brand commitment. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  10. A case of immunoglobulin G-4 related sclerosing disease mimicking lung cancer

    International Nuclear Information System (INIS)

    Kwon, Soo Hee; Lee, Young Kyung; Shim, Mi Suk; Lee, Hyang Im

    2013-01-01

    Immunoglobulin (Ig) G4-related sclerosing disease is a recently described systemic fibro-inflammatory disease associated with an elevated circulating level of IgG4 and extensive IgG4-positive lymphoplasmacytic infiltration, resulting in sclerosing inflammation involving various body organs. We experienced one case where surgery confirmed IgG4-related sclerosing disease as a solitary lung mass mimicking lung cancer. We report radiologic findings including chest computed tomography and positron emission tomography computed tomography, with clinical manifestations of IgG4-related sclerosing disease.

  11. Immunoglobulin G4-Related Sclerosing Disease Involving the Urethra: Case Report

    International Nuclear Information System (INIS)

    Choi, Jin Woo; KIm, Sang Youn; Cho, Jeong Yeon; Kim, Seung Hyup; Moon, Kyung Chul

    2012-01-01

    Immunoglobulin G4 (IgG4)-related sclerosing disease is a systemic disease characterized by extensive IgG4-positive plasma cells and T-lymphocyte infiltration in various organs. We described the imaging findings of an IgG4-related inflammatory pseudotumor in the urethra. The urethral mass showed isoattenuation on unenhanced CT images, delayed enhancement on enhanced CT images, iso- to slight hyper-intensity on T1 and T2 weighted magnetic resonance images, diffusion restriction on diffusion weighted images, and heterogeneously low echogeneity on ultrasonography.

  12. The application of PET/CT in immunoglobulin G4-related disease

    International Nuclear Information System (INIS)

    Zhang Huiwei; Zhao Jun

    2013-01-01

    Immunoglobulin G4 (IgG4)-related disease is a kind of new systemic entity characterized by mass-forming lesions in various organs that consist of lymphoplasmacytic infiltrates and fibrosclerosis with numerous IgG4-positive plasma cells. PET/CT has been widely used in clinical as a whole body examination that earned plenty of successful experience, especially in multiple locations and organs cancer such as lymphoma. PET/CT also has a potential application in IgG4-related diseases as its feature of systemic. (authors)

  13. Tumefactive immunoglobulin G4-related disease involving the dura mater: A case report and literature review

    International Nuclear Information System (INIS)

    Lee, Jeong Hoon; Lee, Ji Hoon; Ko, Yong; Paik, Seoung Sam; Lee, Young Jun; Park, Dong Woo

    2015-01-01

    Immunoglobulin G4 (IgG4)-related disease is a well-known disorder characterized by an inflammatory reaction with an increase in the number of IgG4-positive plasma cells associated with sclerosis. IgG4-related disease often affects the dura mater with a pattern of diffuse thickening when the central nervous system is involved. However, some nodular dural thickening requires discrimination from tumors because of obviously different treatment options. We report of a case of IgG4-related disease with tumefactive dural involvement

  14. Discriminating between true-positive and false-positive clinical mastitis alerts from automatic milking systems

    NARCIS (Netherlands)

    Steeneveld, W.; Gaag, van der L.C.; Ouweltjes, W.; Mollenhorst, H.; Hogeveen, H.

    2010-01-01

    Automatic milking systems (AMS) generate alert lists reporting cows likely to have clinical mastitis (CM). Dutch farmers indicated that they use non-AMS cow information or the detailed alert information from the AMS to decide whether to check an alerted cow for CM. However, it is not yet known to

  15. Detection of immunoglobulin M and immunoglobulin G antibodies to Mycoplasma pneumoniae in children with community-acquired lower respiratory tract infections

    Directory of Open Access Journals (Sweden)

    Surinder Kumar

    2018-01-01

    Full Text Available Context: Mycoplasma pneumoniae (M. pneumoniae causes up to 40% of community-acquired pneumonia in children. It is impossible to identify M. pneumoniae infection on the basis of clinical signs, symptoms, and radiological features. Therefore, correct etiological diagnosis strongly depends on laboratory diagnosis. Aims: This study aims to investigate the role of M. pneumonia e in pediatric lower respiratory tract infections (LRTIs employing enzyme-linked immunosorbent assays (ELISA and particle agglutination (PA test. Settings and Design: Two hundred and eighty children, age 6 months to 12 years with community-acquired LRTIs were investigated for M. pneumoniae etiology. Materials and Methods: We investigated 280 children hospitalized for community-acquired LRTIs, using ELISA and PA test for detecting M. pneumoniae immunoglobulin M (IgM and immunoglobulin G antibodies. Statistical Analysis Used: The difference of proportion between the qualitative variables was tested using the Chi-square test and Fischer exact test. P ≤ 0.05 was considered as statistically significant. Kappa value was used to assess agreement between ELISA and PA test. Results: M. pneumoniae was positive in 51 (23.2% 5 years of age.

  16. Disfluent presentations lead to the creation of more false memories.

    Science.gov (United States)

    Sanchez, Christopher A; Naylor, Jamie S

    2018-01-01

    The creation of false memories within the Deese-Roediger-McDermott (DRM) paradigm has been shown to be sensitive to many factors such as task instructions, participant mood, or even presentation modality. However, do other simple perceptual differences also impact performance on the DRM and the creation of false memories? This study explores the potential impact of changes in perceptual disfluency on DRM performance. To test for a potential influence of disfluency on false memory creation, participants viewed lists under either perceptually disfluent conditions or not. Results indicated that disfluency did significantly impact performance in the DRM paradigm; more disfluent presentations significantly increased the recall and recognition of unpresented information, although they did not impact recall or recognition of presented information. Thus, although disfluency did impact performance, disfluency did not produce a positive benefit related to overall task performance. This finding instead suggests that more disfluent presentations can increase the likelihood that false memories are created, and provide little positive performance benefit.

  17. Attitude Importance and the False Consensus Effect.

    Science.gov (United States)

    Fabrigar, Leandre R.; Krosnick, Jon A.

    1995-01-01

    Explores the possibility that importance may regulate the magnitude of the false consensus effect. Analysis revealed a strong false consensus effect but no reliable relation between its magnitude and attitude importance. Results contradict assumptions that the false consensus effect arises from attitudes that directly or indirectly influence…

  18. Tattooing to "Toughen up": Tattoo experience and secretory immunoglobulin A.

    Science.gov (United States)

    Lynn, Christopher D; Dominguez, Johnna T; DeCaro, Jason A

    2016-09-10

    A costly signaling model suggests tattooing inoculates the immune system to heightened vigilance against stressors associated with soft tissue damage. We sought to investigate this "inoculation hypothesis" of tattooing as a costly honest signal of fitness. We hypothesized that the immune system habituates to the tattooing stressor in repeatedly tattooed individuals and that immune response to the stress of the tattooing process would correlate with lifetime tattoo experience. Participants were 24 women and 5 men (aged 18-47). We measured immune function using secretory immunoglobulin A (SIgA) and cortisol (sCORT) in saliva collected before and after tattoo sessions. We measured tattoo experience as a sum of number of tattoos, lifetime hours tattooed, years since first tattoo, percent of body covered, and number of tattoo sessions. We predicted an inverse relationship between SIgA and sCORT and less SIgA immunosuppression among those with more tattoo experience. We used hierarchical multiple regression to test for a main effect of tattoo experience on post-tattoo SIgA, controlling for pretest SIgA, tattoo session duration, body mass, and the interaction between tattoo experience and test session duration. The regression model was significant (P = 0.006) with a large effect size (r(2)  = 0.711) and significant and positive main (P = 0.03) and interaction effects (P = 0.014). Our data suggest that the body habituates over time to the tattooing stressor. It is possible that individuals with healthy immune systems heal faster, making them more likely to get multiple tattoos. Am. J. Hum. Biol. 28:603-609, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Exquisite response to intravenous immunoglobulin in Susac syndrome during pregnancy

    Directory of Open Access Journals (Sweden)

    Enrique Gomez-Figueroa

    2018-03-01

    Full Text Available Introduction: From its initial report on two female patients in 1979 by J.O. Susac, Susac syndrome (SuS or SICRET (small infarctions of cochlear, retinal and encephalic tissue has persisted as an elusive entity. To date the available evidence for its treatment is based on case reports and case series. The largest systematic review described only 304 reported cases since the 1970s. Here we presented the first reported case to our knowledge in Mexican population and the unusual presentation in a pregnant patient. Case presentation: A 34-year-old Hispanic woman was brought to the ER in our hospital for apathy and behavioral changes. Upon arrival at the ER, her husband described a one-month history of behavioral changes with apathy, progressive abulia, visuospatial disorientation, and gait deterioration. The initial lab test shows no significance except by a positive qualitative hCG. An MRI was obtained and showed hyperintense periventricular white matter lesions in T2 and FLAIR sequences also involving bilateral basal ganglia and with predominant affection of the corpus callosum, in addition to infratentorial cerebellar lesions. After treatment with intravenous immunoglobulins a marked and prompt clinical and radiological improvement was observed. Conclusion: SuS is still an elusive disease. To date, no definitive score or clinical feature can predict the outcome of the disease. The presentation during pregnancy is also rare and therefore the optimal treatment and the prognosis is unknown. We hope that this article will serve as a foundation for future research. Keywords: Susac syndrome, Neuroinflammation, Corpus callosum, Demyelinating disease, Vasculitis

  20. SCM, the M Protein of Streptococcus canis Binds Immunoglobulin G.

    Science.gov (United States)

    Bergmann, Simone; Eichhorn, Inga; Kohler, Thomas P; Hammerschmidt, Sven; Goldmann, Oliver; Rohde, Manfred; Fulde, Marcus

    2017-01-01

    The M protein of Streptococcus canis (SCM) is a virulence factor and serves as a surface-associated receptor with a particular affinity for mini-plasminogen, a cleavage product of the broad-spectrum serine protease plasmin. Here, we report that SCM has an additional high-affinity immunoglobulin G (IgG) binding activity. The ability of a particular S. canis isolate to bind to IgG significantly correlates with a scm -positive phenotype, suggesting a dominant role of SCM as an IgG receptor. Subsequent heterologous expression of SCM in non-IgG binding S. gordonii and Western Blot analysis with purified recombinant SCM proteins confirmed its IgG receptor function. As expected for a zoonotic agent, the SCM-IgG interaction is species-unspecific, with a particular affinity of SCM for IgGs derived from human, cats, dogs, horses, mice, and rabbits, but not from cows and goats. Similar to other streptococcal IgG-binding proteins, the interaction between SCM and IgG occurs via the conserved Fc domain and is, therefore, non-opsonic. Interestingly, the interaction between SCM and IgG-Fc on the bacterial surface specifically prevents opsonization by C1q, which might constitute another anti-phagocytic mechanism of SCM. Extensive binding analyses with a variety of different truncated SCM fragments defined a region of 52 amino acids located in the central part of the mature SCM protein which is important for IgG binding. This binding region is highly conserved among SCM proteins derived from different S. canis isolates but differs significantly from IgG-Fc receptors of S. pyogenes and S. dysgalactiae sub. equisimilis , respectively. In summary, we present an additional role of SCM in the pathogen-host interaction of S. canis . The detailed analysis of the SCM-IgG interaction should contribute to a better understanding of the complex roles of M proteins in streptococcal pathogenesis.

  1. Voting experiments: Bandwagon voting or false-consensus effect?

    OpenAIRE

    Ivo Bischoff; Henrik Egbert

    2008-01-01

    In an experiment designed to test for expressive voting, Tyran (JPubEc 2004) found a strong positive correlation between the participants' approval for a proposal to donate money for charity and their expected approval rate for fellow voters. This phenomenon can be due to bandwagon voting or a false consensus effect. The social science literature reports both effects for voting decisions. Replicating Tyran's experiment and adding new treatments, we provide evidence for a false consensus effec...

  2. Bacteriostatic enterochelin-specific immunoglobulin from normal human serum

    Energy Technology Data Exchange (ETDEWEB)

    Moore, D.G.; Yancey, R.J.; Lankford, C.E.; Earhart, C.F.

    1980-02-01

    Heat-inactivated normal human serum produces iron-reversible bacteriostasis of a number of microorganisms. This inhibitory effect was abolished by adsorption of serum with ultraviolet-killed cells of species that produce the siderophore enterochelin. Bacteriostasis also was alleviated by asorption of serum with 2,3-dihydroxy-N-benzoyl-L-serine, a degradation product of enterochelin, bound to the insoluble matrix AH-Sepharose 4B. Our results indicate that enterochelin-specific immunoglobulins exist in normal human serum. These immunoglobulins may act synergistically with transferrin to effect bacteriostasis of enterochelin-producing pathogens.

  3. Recursive belief manipulation and second-order false-beliefs

    DEFF Research Database (Denmark)

    Braüner, Torben; Blackburn, Patrick Rowan; Polyanskaya, Irina

    2016-01-01

    it indicate that a more fundamental *conceptual change* has taken place? In this paper we extend Braüner's hybrid-logical analysis of first-order false-belief tasks to the second-order case, and argue that our analysis supports a version of the conceptual change position.......The literature on first-order false-belief is extensive, but less is known about the second-order case. The ability to handle second-order false-beliefs correctly seems to mark a cognitively significant step, but what is its status? Is it an example of *complexity only* development, or does...

  4. Immunoglobulin heavy-chain fluorescence in situ hybridization-chromogenic in situ hybridization DNA probe split signal in the clonality assessment of lymphoproliferative processes on cytological samples.

    Science.gov (United States)

    Zeppa, Pio; Sosa Fernandez, Laura Virginia; Cozzolino, Immacolata; Ronga, Valentina; Genesio, Rita; Salatiello, Maria; Picardi, Marco; Malapelle, Umberto; Troncone, Giancarlo; Vigliar, Elena

    2012-12-25

    The human immunoglobulin heavy-chain (IGH) locus at chromosome 14q32 is frequently involved in different translocations of non-Hodgkin lymphoma (NHL), and the detection of any breakage involving the IGH locus should identify a B-cell NHL. The split-signal IGH fluorescence in situ hybridization-chromogenic in situ hybridization (FISH-CISH) DNA probe is a mixture of 2 fluorochrome-labeled DNAs: a green one that binds the telomeric segment and a red one that binds the centromeric segment, both on the IGH breakpoint. In the current study, the authors tested the capability of the IGH FISH-CISH DNA probe to detect IGH translocations and diagnose B-cell lymphoproliferative processes on cytological samples. Fifty cytological specimens from cases of lymphoproliferative processes were tested using the split-signal IGH FISH-CISH DNA probe and the results were compared with light-chain assessment by flow cytometry (FC), IGH status was tested by polymerase chain reaction (PCR), and clinicohistological data. The signal score produced comparable results on FISH and CISH analysis and detected 29 positive, 15 negative, and 6 inadequate cases; there were 29 true-positive cases (66%), 9 true-negative cases (20%), 6 false-negative cases (14%), and no false-positive cases (0%). Comparing the sensitivity of the IGH FISH-CISH DNA split probe with FC and PCR, the highest sensitivity was obtained by FC, followed by FISH-CISH and PCR. The split-signal IGH FISH-CISH DNA probe is effective in detecting any translocation involving the IGH locus. This probe can be used on different samples from different B-cell lymphoproliferative processes, although it is not useful for classifying specific entities. Cancer (Cancer Cytopathol) 2012;. © 2012 American Cancer Society. Copyright © 2012 American Cancer Society.

  5. Avoiding the False Peaks in Correlation Discrimination

    International Nuclear Information System (INIS)

    Awwal, A.S.

    2009-01-01

    Fiducials imprinted on laser beams are used to perform video image based alignment of the 192 laser beams in the National Ignition Facility (NIF) of Lawrence Livermore National Laboratory. In many video images, matched filtering is used to detect the location of these fiducials. Generally, the highest correlation peak is used to determine the position of the fiducials. However, when the signal to-be-detected is very weak compared to the noise, this approach totally breaks down. The highest peaks act as traps for false detection. The active target images used for automatic alignment in the National Ignition Facility are examples of such images. In these images, the fiducials of interest exhibit extremely low intensity and contrast, surrounded by high intensity reflection from metallic objects. Consequently, the highest correlation peaks are caused by these bright objects. In this work, we show how the shape of the correlation is exploited to isolate the valid matches from hundreds of invalid correlation peaks, and therefore identify extremely faint fiducials under very challenging imaging conditions

  6. Too Good to be False: Nonsignificant Results Revisited

    Directory of Open Access Journals (Sweden)

    Chris H. J. Hartgerink

    2017-03-01

    Full Text Available Due to its probabilistic nature, Null Hypothesis Significance Testing (NHST is subject to decision errors. The concern for false positives has overshadowed the concern for false negatives in the recent debates in psychology. This might be unwarranted, since reported statistically nonsignificant findings may just be ‘too good to be false’. We examined evidence for false negatives in nonsignificant results in three different ways. We adapted the Fisher test to detect the presence of at least one false negative in a set of statistically nonsignificant results. Simulations show that the adapted Fisher method generally is a powerful method to detect false negatives. We examined evidence for false negatives in the psychology literature in three applications of the adapted Fisher method. These applications indicate that (i the observed effect size distribution of nonsignificant effects exceeds the expected distribution assuming a null-effect, and approximately two out of three (66.7% psychology articles reporting nonsignificant results contain evidence for at least one false negative, (ii nonsignificant results on gender effects contain evidence of true nonzero effects, and (iii the statistically nonsignificant replications from the Reproducibility Project Psychology (RPP do not warrant strong conclusions about the absence or presence of true zero effects underlying these nonsignificant results. We conclude that false negatives deserve more attention in the current debate on statistical practices in psychology. Potentially neglecting effects due to a lack of statistical power can lead to a waste of research resources and stifle the scientific discovery process.

  7. Neuromyelitis optica in a young child with positive serum autoantibody

    OpenAIRE

    Loma, Ingrid P.; Asato, Miya R.; Filipink, Robyn A.; Alper, Gulay

    2008-01-01

    Relapsing neuromyelitis optica is rare in children. The identification of highly specific serum autoantibody marker (neuromyelitis optica –immunoglobulin G) differentiates neuromyelitis optica from other demyelinating disorders particularly in clinically challenging cases. We present a child with multiple episodes of transverse myelitis and optic neuritis with positive neuromyelitis optica-immunoglobulin G titers consistent with a diagnosis of relapsing neuromyelitis optica. Serial titers of ...

  8. Immunoglobulin profile of Nigerian children with Plasmodium ...

    African Journals Online (AJOL)

    SERVER

    2008-01-18

    Jan 18, 2008 ... IgG correlated positively with the level of malarial parasitaemia (r = 0.99). We deduce that ... stages of Plasmodium falciparum and attempts have con- sequently been ... analysis using Microsoft Excel package. RESULTS.

  9. Combined roentgenoultrasonic diagnosis of false pancreatic cysts

    International Nuclear Information System (INIS)

    Dubrov, Eh.Ya.; Beresneva, Eh.A.; Chervonenkis, A.V.; Morozova, N.A.

    1986-01-01

    X-ray and ultrasound semiotics of false pancreatic cysts in 21 patients have been described. Such a study proves to be highly informative permitting early detection of false pancreatic cysts and observation of the stages of their formation and development of complications. The ultrasound method has advantages for the investigation of patients in early time of false cyst formation and provides an opportunity to detect formations of minimum sizes

  10. Acute phase proteins and immunoglobulin classes in newly ...

    African Journals Online (AJOL)

    Background: No single organic cause has been found for schizophrenia and its management has been difficult. More so, there are few data on the immune parameters of Nigerian schizophrenic patients on drug treatment and those that are not on treatment. Methodology: This study determines the levels of immunoglobulin

  11. Pattern of intravenous immunoglobulins (IVIG) use in a pediatric ...

    African Journals Online (AJOL)

    EB

    Abstract. Background: Intravenous Immunoglobulin (IVIG) preparations are scarce biological products used for replacement or immunomodulatory effects. Guidelines have been issued by regulatory health authorities to ensure provision of the products for patients who are in severe need. Objectives: The study aimed at ...

  12. Rhesus anti-D immunoglobulin in chronic autoimmune neuropathy

    NARCIS (Netherlands)

    de Jager, AEJ; van der Hoeven, JH

    Objective - To investigate the effect of Rhesus anti-D immunoglobulin (anti-D) in patients with an autoimmune demyelinating neuropathy. Material and methods - Three patients with an autoimmune mediated neuropathy received 1000 IU anti-D weekly for 2 months. Results - Two patients worsened gradually

  13. Sensitive chain specific radioimmunoassay for human immunoglobulins using monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, K; Alderson, T St.J.; Ellis, J [Ludwig Institute for Cancer Research, Cambridge (UK)

    1983-02-25

    A sensitive radioimmunoassay is described for human immunoglobulins. This solid-phase assay uses commercially available monoclonal antibodies and is specific for different Ig chain types. Levels of less than 20 ng/ml Ig are detectable. The assay is suitable for the analysis of human hybridoma supernatants.

  14. Immunoglobulin therapy in hematologic neoplasms and after hematopoietic cell transplantation.

    Science.gov (United States)

    Ueda, Masumi; Berger, Melvin; Gale, Robert Peter; Lazarus, Hillard M

    2018-03-01

    Immunoglobulins are used to prevent or reduce infection risk in primary immune deficiencies and in settings which exploit its anti-inflammatory and immune-modulatory effects. Rigorous proof of immunoglobulin efficacy in persons with lympho-proliferative neoplasms, plasma cell myeloma, and persons receiving hematopoietic cell transplants is lacking despite many clinical trials. Further, there are few consensus guidelines or algorithms for use in these conditions. Rapid development of new therapies targeting B-cell signaling and survival pathways and increased use of chimeric antigen receptor T-cell (CAR-T) therapy will likely result in more acquired deficiencies of humoral immunity and infections in persons with cancer. We review immunoglobulin formulations and discuss efficacy and potential adverse effects in the context of preventing infections and in graft-versus-host disease. We suggest an algorithm for evaluating acquired deficiencies of humoral immunity in persons with hematologic neoplasms and recommend appropriate use of immunoglobulin therapy. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Alpha chain determinants on the membrane of immunoglobulin synthesizing cells

    NARCIS (Netherlands)

    Hijmans, W.; Schuit, H.R.E.; Radl, J.; Vossen, J.M.J.J.

    1974-01-01

    In a study of surface immunoglobulins (Ig) on lymphocytes from patients with paraproteinemia (1), we observed that a variable number of plasma cells not only contained intracellular Ig, but also had Ig on their surface, as shown in the vital technique of immunofluorescence. Moreover, in the bone

  16. Bacteremia and immunoglobulin classes in Nigerian women with ...

    African Journals Online (AJOL)

    Apart from antiphospholipid- and thyroid- autoantibodies which were reported as underlying causes of recurrent pregnancy loss, specific IgG to patermal MHC and Rh was proposed. This raises the possibility of other classes of immunoglobulin in recurrent abortion. Twenty-four pregnant women with recurrent abortion ...

  17. serum immunoglobulin levels in white, asiatic and bantu blood donors

    African Journals Online (AJOL)

    all assays were calculated as a percentage of the mean of. TABLE I. RESULTS OF IMMUNOGLOBULIN ASSAYS OF tOO WHITE, tOO ASIATIC AND 100 BANTU DONORS, EXPRESSED AS A. PERCENTAGE OF A CONTROL SERUM. Parameter. Range. Mean. Variance. Standard deviation. CoefI. of variation.

  18. Haemolytic anaemia as a complication to intravenous immunoglobulin infusion

    DEFF Research Database (Denmark)

    Markvardsen, Lars Høj; Harbo, Thomas; Christiansen, Ingelise

    performed before and two weeks after infusion of IVIg. Following treatment blood haemoglobin declined from 8.6±0.8 to 8.1±1.3mmol/l, p... naive patients are susceptible to develop haemolysis. Haemolytic anaemia is a severe side effect that seems to be more frequent after immunoglobulin infusions than previously recognized....

  19. Solvent-Detergent Treatment of IgM-Enriched Immunoglobulin

    Directory of Open Access Journals (Sweden)

    Mojgan Pourmokhtar

    2003-08-01

    Full Text Available Viral safety of human plasma products plays a key role in their safe uses. Solvent- detergent (SD virus-inactivation method has gained widespread popularity in the manufacture of biological products. This treatment which inactivates lipid-enveloped viruses effectively consists of incubation of a plasma protein solution in the presence of a non-volatile organic solvent and a detergent. In this study, IgM-enriched immunoglobulin was incubated at 24 °C for 6 h under slow stirring in the presence of tri(n-butyl phosphate (0.3% w/w as solvent and tween 80 (1% w/w as detergent. After completion of the inactivation process and removal of the solvent-detergent, the ability of SD-treatment to remove Infectious Bovine Rhinotracheitis (IBR virus (a lipid-enveloped virus and Foot-and-Mouth Disease virus (a non-enveloped virus were evaluated by "virus spiking studies" using a scaled down process. Reduction factor of 4 log was obtained for the SD-treatment of IgM-enriched immunoglobulin spiked with IBR virus. No virus inactivation was observed in the SD-treated IgM-enriched immunoglobulin, spiked with Foot-and-Mouth Disease virus. It was concluded that treatment of IgM-enriched immunoglobulin with TNBP-TWEEN 80 may be considered as an efficient lipid-enveloped virus inactivation step in the manufacture of this product.

  20. Mechanism of immunoglobulin G4 Fab-arm exchange

    NARCIS (Netherlands)

    Rispens, Theo; Ooijevaar-de Heer, Pleuni; Bende, Onno; Aalberse, Rob C.

    2011-01-01

    Immunoglobulin G (IgG) antibodies are symmetrical molecules that may be regarded as covalent dimers of 2 half-molecules, each consisting of a light chain and a heavy chain. Human IgG4 is an unusually dynamic antibody, with half-molecule exchange ("Fab-arm exchange") resulting in asymmetrical,

  1. Effect of continuous milking on immunoglobulin concentrations in bovine colostrum

    NARCIS (Netherlands)

    Verweij, J.J.; Koets, A.P.; Eisenberg, S.W.F.

    2014-01-01

    Continuous milking is defined as a dairy cattle management system without a planned dry period for cows in late gestation. Continuous milking has been described to reduce health problems common in periparturient cattle, but may affect colostrum immunoglobulin (Ig) concentration and subsequently calf

  2. Inhibition mechanisms of hemoglobin, immunoglobulin G, and whole blood in digital and real-time PCR.

    Science.gov (United States)

    Sidstedt, Maja; Hedman, Johannes; Romsos, Erica L; Waitara, Leticia; Wadsö, Lars; Steffen, Carolyn R; Vallone, Peter M; Rådström, Peter

    2018-04-01

    Blood samples are widely used for PCR-based DNA analysis in fields such as diagnosis of infectious diseases, cancer diagnostics, and forensic genetics. In this study, the mechanisms behind blood-induced PCR inhibition were evaluated by use of whole blood as well as known PCR-inhibitory molecules in both digital PCR and real-time PCR. Also, electrophoretic mobility shift assay was applied to investigate interactions between inhibitory proteins and DNA, and isothermal titration calorimetry was used to directly measure effects on DNA polymerase activity. Whole blood caused a decrease in the number of positive digital PCR reactions, lowered amplification efficiency, and caused severe quenching of the fluorescence of the passive reference dye 6-carboxy-X-rhodamine as well as the double-stranded DNA binding dye EvaGreen. Immunoglobulin G was found to bind to single-stranded genomic DNA, leading to increased quantification cycle values. Hemoglobin affected the DNA polymerase activity and thus lowered the amplification efficiency. Hemoglobin and hematin were shown to be the molecules in blood responsible for the fluorescence quenching. In conclusion, hemoglobin and immunoglobulin G are the two major PCR inhibitors in blood, where the first affects amplification through a direct effect on the DNA polymerase activity and quenches the fluorescence of free dye molecules, and the latter binds to single-stranded genomic DNA, hindering DNA polymerization in the first few PCR cycles. Graphical abstract PCR inhibition mechanisms of hemoglobin and immunoglobulin G (IgG). Cq quantification cycle, dsDNA double-stranded DNA, ssDNA single-stranded DNA.

  3. Diverse binding site structures revealed in homology models of polyreactive immunoglobulins

    Science.gov (United States)

    Ramsland, Paul A.; Guddat, Luke W.; Edmundson, Allen B.; Raison, Robert L.

    1997-09-01

    We describe here computer-assisted homology models of the combiningsite structure of three polyreactive immunoglobulins. Template-based modelsof Fv (VL-VH) fragments were derived forthe surface IgM expressed by the malignant CD5 positive B cells from threepatients with chronic lymphocytic leukaemia (CLL). The conserved frameworkregions were constructed using crystal coordinates taken from highlyhomologous human variable domain structures (Pot and Hil). Complementaritydetermining regions (CDRs) were predicted by grafting loops, taken fromknown immunoglobulin structures, onto the Fv framework models. The CDRtemplates were chosen, where possible, to be of the same length and of highresidue identity or similarity. LCDR1, 2 and 3 as well as HCDR1 and 2 forthe Fv were constructed using this strategy. For HCDR3 prediction, adatabase containing the Cartesian coordinates of 30 of these loops wascompiled from unliganded antibody X-ray crystallographic structures and anHCDR3 of the same length as that of the B CLL Fv was selected as a template.In one case (Yar), the resulting HCDR3 model gave unfavourable interactionswhen incorporated into the Fv model. This HCDR3 was therefore modelled usingan alternative strategy of construction of the loop stems, using apreviously described HCDR3 conformation (Pot), followed by chain closurewith a β-turn. The template models were subjected to positionalrefinement using energy minimisation and molecular dynamics simulations(X-PLOR). An electrostatic surface description (GRASP) did not reveal acommon structural feature within the binding sites of the three polyreactiveFv. Thus, polyreactive immunoglobulins may recognise similar and multipleantigens through a diverse array of binding site structures.

  4. Intellectual factors in false memories of patients with schizophrenia.

    Science.gov (United States)

    Zhu, Bi; Chen, Chuansheng; Loftus, Elizabeth F; Dong, Qi; Lin, Chongde; Li, Jun

    2018-07-01

    The current study explored the intellectual factors in false memories of 139 patients with schizophrenia, using a recognition task and an IQ test. The full-scale IQ score of the participants ranged from 57 to 144 (M = 100, SD = 14). The full IQ score had a negative correlation with false recognition in patients with schizophrenia, and positive correlations with high-confidence true recognition and discrimination rates. Further analyses with the subtests' scores revealed that false recognition was negatively correlated with scores of performance IQ (and one of its subtests: picture arrangement), whereas true recognition was positively correlated with scores of verbal IQ (and two of its subtests: information and digit span). High-IQ patients had less false recognition (overall or high-confidence false recognition), more high-confidence true recognition, and higher discrimination abilities than those with low IQ. These findings contribute to a better understanding of the cognitive mechanism in false memory of patients with schizophrenia, and are of practical relevance to the evaluation of memory reliability in patients with different intellectual levels. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Molecular Analysis of Activation-Induced Cytidine Deaminase Gene in Immunoglobulin-E Deficient Patients

    Directory of Open Access Journals (Sweden)

    Sergio Roa

    2008-01-01

    Full Text Available Understanding how class switch recombination (CSR is regulated to produce immunoglobulin E (IgE has become fundamental because of the dramatic increase in the prevalence of IgE-mediated hypersensitivity reactions. CSR requires the induction of the enzyme AICDA in B cells. Mutations in AICDA have been linked to Hyper-IgM syndrome (HIGM2, which shows absence of switching to IgE as well as to IgG and IgA. Although isolated IgE deficiency is a rare entity, here we show some individuals with normal serum IgM, IgG, and IgA levels that had undetectable total serum IgE levels. We have analyzed the AICDA gene in these individuals to determine if there are mutations in AICDA that could lead to selective IgE deficiency. Conformational sensitive gel electrophoresis (CSGE and sequencing analysis of AICDA coding sequences demonstrated sequence heterogeneity due to 5923A/G and 7888C/T polymorphisms, but did not reveal any novel mutation that might explain the selective IgE deficit.

  6. Is it wise to protect false targets?

    International Nuclear Information System (INIS)

    Levitin, Gregory; Hausken, Kjell

    2011-01-01

    The paper considers a system consisting of genuine elements and false targets that cannot be distinguished by the attacker's observation. The false targets can be destroyed with much less effort than the genuine elements. We show that even when an attacker cannot distinguish between the genuine elements and the false targets, in many cases it can enhance the attack efficiency using a double attack strategy in which it tries first to eliminate with minimal effort as many false targets as possible in the first attack and then distributes its entire remaining resource among all surviving targets in the second attack. The model for evaluating the system vulnerability in the double attack is suggested for a single genuine element, and multiple genuine elements configured in parallel or in series. This model assumes that in both attacks the attacking resource is distributed evenly among the attacked targets. The defender can optimize its limited resource distribution between deploying more false targets and protecting them better. The attacker can optimize its limited resource distribution between two attacks. The defense strategy is analyzed based on a two period minmax game. A numerical procedure is suggested that allows the defender to find the optimal resource distribution between deploying and protecting the false targets. The methodology of optimal attack and defense strategies analysis is demonstrated. It is shown that protecting the false targets may reduce the efficiency of the double attack strategy and make this strategy ineffective in situations with low contest intensity and few false targets. - Highlights: ► The efficiency of the double attack tactics against using false targets is analyzed. ► The role of the false target protection in system survivability enhancement is shown. ► The resource distribution between deploying more false targets and protecting them better is optimized. ► Both series and parallel systems are considered.

  7. Social influence and mental routes to the production of authentic false memories and inauthentic false memories.

    Science.gov (United States)

    Wagner, Michael F; Skowronski, John J

    2017-05-01

    Two studies assessed the extent to which people incorporated false facts provided by bogus others into their own recognition memory reports, and how these false memory reports were affected by: (a) truth of the information in others' summaries supporting the false facts, (b) motivation to process stories and summaries, (c) source credibility, and (d) ease of remembering original facts. False memory report frequency increased when false facts in a summary were supported by true information and varied inversely with the ease with which original facts could be remembered. Results from a measure probing participants' memory perceptions suggest that some false memories are authentic: People sometimes lack awareness of both the incorporation of false facts into their memory reports and where the false facts came from. However, many false memories are inauthentic: Despite reporting a false memory, people sometimes retain knowledge of the original stimulus and/or the origin of false facts. Copyright © 2017. Published by Elsevier Inc.

  8. Immunoglobulin concentration in blood serum of postcolostral calves: Ratio between immunoglobulin level and appearance of enzootic pneumonia

    Directory of Open Access Journals (Sweden)

    Jonić Branko

    2007-01-01

    Full Text Available The timely supply of newborn calves with optimal quantities of colostrum has a key role in the process of immune protection in the early phase of their lives. Passively acquired antibodies can protect the digestive organs from infection caused by E.coli bacteria, and it seems also from the appearance of diseases of the respiratory tract. These examinations were performed on a cattle farm where bronchopneumonia was one of the most significant health problems, and a group of 39 calves were selected for the investigations. The calves were fed with their mothers’ colostrum after birth, and then with collective milk. Immunoglobulin concentration was determined in blood samples taken during the postcolostral period, with the method using zinc-sulphate. At the age of 40 days, the calves were administered a polyvalent inactivated vaccine, and revaccinated 20 days after that (Vibak, Veterinary Department Subotica. In 74.34% calves, the immunoglobulin G concentration ranged from 26 to 40 g/l. In 25.66% calves, the immunoglobulin concentration was lower, from 8 to 25 g/l. The calves found to have a lower concentration of immunoglobulin in blood contracted bronchopneumonia more frequently, and the outcome of the disease in some cases was mortality, even.

  9. Can False Memories Prime Problem Solutions?

    Science.gov (United States)

    Howe, Mark L.; Garner, Sarah R.; Dewhurst, Stephen A.; Ball, Linden J.

    2010-01-01

    Previous research has suggested that false memories can prime performance on related implicit and explicit memory tasks. The present research examined whether false memories can also be used to prime higher order cognitive processes, namely, insight-based problem solving. Participants were asked to solve a number of compound remote associate task…

  10. Explaining the Development of False Memories.

    Science.gov (United States)

    Reyna, Valerie F.; Holliday, Robyn; Marche, Tammy

    2002-01-01

    Reviews explanatory dimensions of children's false memory relevant to forensic practice: measurement, development, social factors, individual differences, varieties of memories and memory judgments, and varieties of procedures inducing false memories. Asserts that recent studies fail to use techniques that separate acquiescence from memory…

  11. New false color mapping for image fusion

    NARCIS (Netherlands)

    Toet, A.; Walraven, J.

    1996-01-01

    A pixel based colour mapping algorithm is presented that produces a fused false colour rendering of two gray level images representing different sensor modalities. The result-ing fused false colour images have a higher information content than each of the original images and retain sensor-specific

  12. Effects of Instructions on False Recognition.

    Science.gov (United States)

    Mueller, John H.; And Others

    Four experiments were conducted to examine the effects of various processing instructions on the rate of false recognition. The continuous single-item procedure was used, and false recognitions of four types were examined: synonyms, antonyms, nonsemantic associates, and homonyms. The instructions encouraged subjects to think of associates, usages…

  13. The probability of the false vacuum decay

    International Nuclear Information System (INIS)

    Kiselev, V.; Selivanov, K.

    1983-01-01

    The closed expession for the probability of the false vacuum decay in (1+1) dimensions is given. The probability of false vacuum decay is expessed as the product of exponential quasiclassical factor and a functional determinant of the given form. The method for calcutation of this determinant is developed and a complete answer for (1+1) dimensions is given

  14. Using immunoglobulin Y as an alternative antibody for the detection of hepatitis A virus in frozen liver sections

    Directory of Open Access Journals (Sweden)

    Gentil Arthur Bentes

    2015-06-01

    Full Text Available An increasing amount of research has been conducted on immunoglobulin Y (IgY because the use of IgY offers several advantages with respect to diagnostic testing, including its easy accessibility, low cost and translatability to large-scale production, in addition to the fact that it can be ethically produced. In a previous work, immunoglobulin was produced and purified from egg yolks (IgY reactive to hepatitis A virus (HAV antigens. In the present work, this anti-HAV-specific IgY was used in an indirect immunofluorescence assay to detect viral antigens in liver biopsies that were obtained from experimentally infected cynomolgus monkeys. Fields that were positive for HAV antigen were detected in liver sections using confocal microscopy. In conclusion, egg yolks from immunised hens may be a reliable source for antibody production, which can be employed for immunological studies.

  15. Inflammatory myofibroblastic tumor of the mesentery associated with high fever and positive Widal test

    International Nuclear Information System (INIS)

    Chouairy, Camil J.; Bechara, Elie A.; Ghabril, Ramy H.; Gebran, Sleiman J.

    2008-01-01

    Inflammatory myofibroblastic tumor (IMT) is associated in 15-30% of cases with systemic symptomatology , such as prolonged fever, weight loss, elevated erythrocyte sedimentation rate (ESR) , anemia, thrombocytosis and leukocytosis. We report the case of a 4-year-old Lebanese boy who presented with high-grade fever of long duration and a single (unpaired) positive Widal agglutination test. Blood culture was negative. A diagnosis of typhoid fever was made. An abdominal (mesenteric) IMT was incidentally discovered, 30 days after the fever had appeared. After surgery, the fever disappeared immediately, and the ESR returned. We strongly favor the possibility of a false positive Widal test, due to polyclonal increase in serum immunoglobulins, which often occurs in IMT. We also think that IMT might be a mimicker of typhoid fever, both clinically and serologically. Physicians, especially pediatricians practicing in endemic areas, should probably be aware of this mimicry. (author)

  16. Inflammatory myofibroblastic tumor of the mesentery associated with high fever and positive Widal test

    Energy Technology Data Exchange (ETDEWEB)

    Chouairy, Camil J [Dept. of Pathology, Saint George Hospital, Beirut (Lebanon); Bechara, Elie A; Ghabril, Ramy H [Dept. of Pediatrics, Saint George Hospital, Beirut (Lebanon); Gebran, Sleiman J [Dept. of Pediatric Surgery, AlHada Armed Forces Hospital, Taif (Saudi Arabia)

    2008-07-01

    Inflammatory myofibroblastic tumor (IMT) is associated in 15-30% of cases with systemic symptomatology , such as prolonged fever, weight loss, elevated erythrocyte sedimentation rate (ESR) , anemia, thrombocytosis and leukocytosis. We report the case of a 4-year-old Lebanese boy who presented with high-grade fever of long duration and a single (unpaired) positive Widal agglutination test. Blood culture was negative. A diagnosis of typhoid fever was made. An abdominal (mesenteric) IMT was incidentally discovered, 30 days after the fever had appeared. After surgery, the fever disappeared immediately, and the ESR returned. We strongly favor the possibility of a false positive Widal test, due to polyclonal increase in serum immunoglobulins, which often occurs in IMT. We also think that IMT might be a mimicker of typhoid fever, both clinically and serologically. Physicians, especially pediatricians practicing in endemic areas, should probably be aware of this mimicry. (author)

  17. Rapid induction of false memory for pictures.

    Science.gov (United States)

    Weinstein, Yana; Shanks, David R

    2010-07-01

    Recognition of pictures is typically extremely accurate, and it is thus unclear whether the reconstructive nature of memory can yield substantial false recognition of highly individuated stimuli. A procedure for the rapid induction of false memories for distinctive colour photographs is proposed. Participants studied a set of object pictures followed by a list of words naming those objects, but embedded in the list were names of unseen objects. When subsequently shown full colour pictures of these unseen objects, participants consistently claimed that they had seen them, while discriminating with high accuracy between studied pictures and new pictures whose names did not appear in the misleading word list. These false memories can be reported with high confidence as well as the feeling of recollection. This new procedure allows the investigation of factors that influence false memory reports with ecologically valid stimuli and of the similarities and differences between true and false memories.

  18. Priming analogical reasoning with false memories.

    Science.gov (United States)

    Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

    2015-08-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.

  19. Intravenous immunoglobulin prophylaxis in neonates on artificial ...

    African Journals Online (AJOL)

    There were no significant differences in the treated and placebo groups with regard to the frequency of positive blood cultures 28.6% and 14.3%), endotracheal cultures ... Analyses of subgroups of patients with different diagnoses revealed no differences except a trend suggesting fewer infections in term babies treated with ...

  20. Siblings, Language, and False Belief in Low-Income Children

    Science.gov (United States)

    Tompkins, Virginia; Farrar, M. Jeffrey; Guo, Ying

    2013-01-01

    The authors examined the relationship between number of siblings and false belief understanding (FBU) in 94 low-income 4-5-year-olds. Previous research with middle-income children has shown a positive association between number of siblings and FBU. However, it is unclear whether having multiple siblings in low-income families is related to better…

  1. Teacher Education and the Enduring Significance of "False Empathy"

    Science.gov (United States)

    Warren, Chezare A.; Hotchkins, Bryan K.

    2015-01-01

    The concept "False Empathy" posited by critical race theory luminary Richard Delgado ("Calif Law Rev" 84(1):61-100, 1996) easily obscures White teacher's good intentions to be effective educators of racially, culturally, and linguistically diverse students. It is argued here that critical race theory is useful for isolating and…

  2. Current management of inguinal false aneurysms

    DEFF Research Database (Denmark)

    Houlind, Kim; Jepsen, Jørn M; Saicu, Cristian

    2017-01-01

    False aneurysms are formed as a result of bleeding causing a hematoma to compress the surrounding tissue. The majority of false aneurysms presenting to the vascular surgeon are caused by iatrogenic injury to an artery. Although anastomotic failure occurs, a much higher number is caused by bleeding...... vessels. endovascular treatment with coils or covered stent grafts have proven useful in infected ilio-femoral false aneurysms. Open surgical repair may be the best treatment in the setting of imminent rupture, massive haematoma and skin necrosis. We present three patient cases treated with open surgery...

  3. Significantly improved PCR-based clonality testing in B-cell malignancies by use of multiple immunoglobulin gene targets. Report of the BIOMED-2 Concerted Action BHM4-CT98-3936.

    NARCIS (Netherlands)

    Evans, P.A.; Pott, C.; Groenen, P.J.T.A.; Salles, G.; Davi, F.; Berger, F.; Garcia, J.F.; Krieken, J.H.J.M. van; Pals, S.; Kluin, P.; Schuuring, E.; Spaargaren, M.; Boone, E.; Gonzalez, D.; Martinez, B.; Villuendas, R.; Gameiro, P.; Diss, T.C.; Mills, K.; Morgan, G.J.; Carter, G.I.; Milner, B.J.; Pearson, D.; Hummel, M.; Jung, W.; Ott, M.; Canioni, D.; Beldjord, K.; Bastard, C.; Delfau-Larue, M.H.; Dongen, J.J.M. van; Molina, T.J.; Cabecadas, J.

    2007-01-01

    Polymerase chain reaction (PCR) assessment of clonal immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements is an important diagnostic tool in mature B-cell neoplasms. However, lack of standardized PCR protocols resulting in a high level of false negativity has hampered comparability of

  4. Immunoglobulin gene repertoire diversification and selection in the stomach – from gastritis to gastric lymphomas

    Directory of Open Access Journals (Sweden)

    Miri eMichaeli

    2014-06-01

    Full Text Available Chronic gastritis is characterized by gastric mucosal inflammation due to autoimmune responses or infection, frequently with Helicobacter pylori. Gastritis with H. pylori background can cause gastric mucosa-associated lymphoid tissue lymphoma (MALT-L, which sometimes further transforms into diffuse large B cell lymphoma (DLBCL. However, gastric DLBCL can also be initiated de novo. The mechanisms underlying transformation into DLBCL are not completely understood. We analyzed immunoglobulin repertoires and clonal trees to investigate whether and how immunoglobulin gene repertoires, clonal diversification and selection in gastritis, gastric MALT-L and DLBCL differ from each other and from normal responses. The two gastritis types (positive or negative for H. pylori had similarly diverse repertoires. MALT-L dominant clones presented higher diversification and longer mutational histories compared with all other conditions. DLBCL dominant clones displayed lower clonal diversification, suggesting the transforming events are triggered by similar responses in different patients. These results are surprising, as we expected to find similarities between the dominant clones of gastritis and MALT-L and between those of MALT-L and DLBCL.

  5. Mental Rotation in False Belief Understanding.

    Science.gov (United States)

    Xie, Jiushu; Cheung, Him; Shen, Manqiong; Wang, Ruiming

    2018-05-01

    This study examines the spontaneous use of embodied egocentric transformation (EET) in understanding false beliefs in the minds of others. EET involves the participants mentally transforming or rotating themselves into the orientation of an agent when trying to adopt his or her visuospatial perspective. We argue that psychological perspective taking such as false belief reasoning may also involve EET because of what has been widely reported in the embodied cognition literature, showing that our processing of abstract, propositional information is often grounded in concrete bodily sensations which are not apparently linked to higher cognition. In Experiment 1, an agent placed a ball into one of two boxes and left. The ball then rolled out and moved either into the other box (new box) or back into the original one (old box). The participants were to decide from which box they themselves or the agent would try to recover the ball. Results showed that false belief performance was affected by increased orientation disparity between the participants and the agent, suggesting involvement of embodied transformation. In Experiment 2, false belief was similarly induced and the participants were to decide if the agent would try to recover the ball in one specific box. Orientation disparity was again found to affect false belief performance. The present results extend previous findings on EET in visuospatial perspective taking and suggest that false belief reasoning, which is a kind of psychological perspective taking, can also involve embodied rotation, consistent with the embodied cognition view. Copyright © 2018 Cognitive Science Society, Inc.

  6. Platelet associated IgG, platelet mean life span and treatment with intravenous immunoglobulin in idiopathic thrombocytopenic purpura

    International Nuclear Information System (INIS)

    Nieminen, U.; Syrjaelae, M.; Ikkala, E.; Myllylae, G.

    1988-01-01

    The clinical significance of platelet associated IgG in ITP detected by direct platelet suspension immunofluorescence test (PSIFT) was studied. The platelet mean life span (MLS) was measured with 111 In-labelled platelets in 17 adult patients. All the patients had shortened platelet MLS. The direct PSIFT was positive in 14 patients. Patients were initially treated with prednisone; 12 patients with poor response to the drug were splenectomised. 8 of these 12 patients were treated with intravenous immunoglobulin (IvIg) before splenectomy. The response to IvIg was as good or better in the 3 patients with negative PSIFT, than in the 5 patients with positive PSIFT. (author)

  7. High levels of immunoglobulin E and a continuous increase in immunoglobulin G and immunoglobulin M by age in children with newly diagnosed type 1 diabetes

    DEFF Research Database (Denmark)

    Svensson, Jannet; Eising, Stefanie; Mortensen, Henrik Bindesbøl

    2012-01-01

    The incidence of type 1 diabetes (T1D) is increasing, either because of environmental factors accelerating onset of the disease or because of inducement of autoimmune diabetes in children who previously were at lower risk. High levels of immunoglobulin (Ig), specifically, IgM and IgA, and a low...... level of IgG were reported in adult patients; however no studies have analyzed the increasing incidence in relation to Ig levels. Our aim was to describe Ig in children newly diagnosed with diabetes and in their healthy siblings. Children with T1D expressed significantly lower IgG (p

  8. Autoantibodies and immunoglobulins in alcoholic steatosis and cirrhosis

    DEFF Research Database (Denmark)

    Gluud, C; Tage-Jensen, Ulrik Viggo

    1983-01-01

    increased (p less than 0.005) concentrations of immunoglobulins G, A, and M when compared to patients with steatosis. These results indicate that the degree of liver damage has more effect than chronic alcoholism on the humoral immune system. Whether this influence is direct or indirect remains......Antinuclear antibodies were significantly more prevalent (p less than 0.01) in 143 patients with alcoholic cirrhosis than in 64 patients with alcoholic steatosis and in 94 controls. Smooth muscle antibodies were significantly more prevalent (p less than 0.05) in patients with alcoholic steatosis...... and cirrhosis than in controls. The prevalence of antimitochondrial antibodies and IgG liver membrane antibodies did not differ significantly between the three groups. Immunoglobulin G, A, and M concentrations were only occasionally increased in patients with steatosis. Patients with cirrhosis had significantly...

  9. A role for PCNA ubiquitination in immunoglobulin hypermutation.

    Directory of Open Access Journals (Sweden)

    Hiroshi Arakawa

    2006-11-01

    Full Text Available Proliferating cell nuclear antigen (PCNA is a DNA polymerase cofactor and regulator of replication-linked functions. Upon DNA damage, yeast and vertebrate PCNA is modified at the conserved lysine K164 by ubiquitin, which mediates error-prone replication across lesions via translesion polymerases. We investigated the role of PCNA ubiquitination in variants of the DT40 B cell line that are mutant in K164 of PCNA or in Rad18, which is involved in PCNA ubiquitination. Remarkably, the PCNA(K164R mutation not only renders cells sensitive to DNA-damaging agents, but also strongly reduces activation induced deaminase-dependent single-nucleotide substitutions in the immunoglobulin light-chain locus. This is the first evidence, to our knowledge, that vertebrates exploit the PCNA-ubiquitin pathway for immunoglobulin hypermutation, most likely through the recruitment of error-prone DNA polymerases.

  10. A database of immunoglobulins with integrated tools: DIGIT.

    KAUST Repository

    Chailyan, Anna; Tramontano, Anna; Marcatili, Paolo

    2011-01-01

    The DIGIT (Database of ImmunoGlobulins with Integrated Tools) database (http://biocomputing.it/digit) is an integrated resource storing sequences of annotated immunoglobulin variable domains and enriched with tools for searching and analyzing them. The annotations in the database include information on the type of antigen, the respective germline sequences and on pairing information between light and heavy chains. Other annotations, such as the identification of the complementarity determining regions, assignment of their structural class and identification of mutations with respect to the germline, are computed on the fly and can also be obtained for user-submitted sequences. The system allows customized BLAST searches and automatic building of 3D models of the domains to be performed.

  11. A database of immunoglobulins with integrated tools: DIGIT.

    KAUST Repository

    Chailyan, Anna

    2011-11-10

    The DIGIT (Database of ImmunoGlobulins with Integrated Tools) database (http://biocomputing.it/digit) is an integrated resource storing sequences of annotated immunoglobulin variable domains and enriched with tools for searching and analyzing them. The annotations in the database include information on the type of antigen, the respective germline sequences and on pairing information between light and heavy chains. Other annotations, such as the identification of the complementarity determining regions, assignment of their structural class and identification of mutations with respect to the germline, are computed on the fly and can also be obtained for user-submitted sequences. The system allows customized BLAST searches and automatic building of 3D models of the domains to be performed.

  12. Prospective study of the changes in thyrotropin binding inhibitory immunoglobulins in Graves' disease treated by subtotal thyroidectomy or radioactive iodine

    International Nuclear Information System (INIS)

    Teng, C.S.; Yeung, R.T.T.; Khoo, R.K.K.; Alagaratnam, T.T.

    1980-01-01

    The effects of subtotal thyroidectomy and radioactive iodine on thyroid-stimulating immunoglobulins, as measured by a receptor assay, more appropriately termed TSH binding inhibitory immunoglobulins (TBII), were studied in 74 patients with Graves' disease. Fourty-four patients received radioactive iodine therapy, while 30 were subjected to subtotal thyroidectomy. After radioactive iodine, more patients were TBII-positive (90.5% vs 81.8%) than before treatment, and the mean TBII index decreased dramatically, the maximum decrease being 3 months. The mean TBI index subsequently returned gradually to the pretreatment level. Subtotal thyroidectomy had a different effect on TBII activity. TBII indices were positive in 89.3% of these patients before any treatment but were positive in only 40% (12 patients) after antithyroid drugs had been given before surgery. After surgery, TBII indices remained positive in 7 patients, while the remaining 5 patients became TBII negative. Seventeen patients (56.7%) were TBII negative before operation and remained so after surgery. One patient who was TBII negative before operation became TBII positive 2 months after operation. Interestingly, postoperative relapse of hyperthyroidism occurred in 3 patients who were TIBII positive, while hypothyroidism occurred in patients who were TBII negative. Thus, the TBII activity after subtotal thyroidectomy might be an important factor in determining the outcome of surgery

  13. Fungicidal activity of peptides encoded by immunoglobulin genes

    OpenAIRE

    Polonelli, Luciano; Ciociola, Tecla; Sperind?, Martina; Giovati, Laura; D?Adda, Tiziana; Galati, Serena; Travassos, Luiz R.; Magliani, Walter; Conti, Stefania

    2017-01-01

    Evidence from previous works disclosed the antimicrobial, antiviral, anti-tumour and/or immunomodulatory activity exerted, through different mechanisms of action, by peptides expressed in the complementarity-determining regions or even in the constant region of antibodies, independently from their specificity and isotype. Presently, we report the selection, from available databases, of peptide sequences encoded by immunoglobulin genes for the evaluation of their potential biological activitie...

  14. CD147 Immunoglobulin Superfamily Receptor Function and Role in Pathology

    OpenAIRE

    Iacono, Kathryn T.; Brown, Amy L.; Greene, Mark I.; Saouaf, Sandra J.

    2007-01-01

    The immunoglobulin superfamily member CD147 plays an important role in fetal, neuronal, lymphocyte and extracellular matrix development. Here we review the current understanding of CD147 expression and protein interactions with regard to CD147 function and its role in pathologic conditions including heart disease, Alzheimer’s disease, stroke and cancer. A model linking hypoxic conditions found within the tumor microenvironment to up-regulation of CD147 expression and tumor progression is intr...

  15. Serologic activity of G immunoglobulin of irradiated rabbits

    International Nuclear Information System (INIS)

    Ivanov, A.A.; Nevinnaya, A.P.; Mozhajskij, A.M.; Snisar', N.A.

    1977-01-01

    Serologic immunochemical properties of immunoglobulins G (IgG) isolated from blood serum of normal rabbits and those given lethal and midlethal doses of radiation have been comparatively studied. A marked increase in the IgG level was detected in the recovery period of radiation sickness. The number of complement-binding antitissue antibodies in IgG grew in that period, and the anticomplementary activity and the catabolism rate of IgG increased in normal organism

  16. Diversity Analysis of the Immunoglobulin M Heavy Chain Gene in ...

    African Journals Online (AJOL)

    A full-length cDNA encoding the immunoglobulin (IgM) heavy chain gene of Nile tilapia was successfully cloned using the 5' and 3' RACE techniques. The complete cDNA of the Nile tilapia IgM heavy chain gene is 1,921 bp in length and has an open reading frame (ORF) of 1,740 bp, which corresponds to 580 amino acid ...

  17. Immunoglobulin G4-related disease: autoimmune pancreatitis and extrapancreatic manifestations

    Directory of Open Access Journals (Sweden)

    Daniel Alvarenga Fernandes

    2016-04-01

    Full Text Available Abstract We present a case of immunoglobulin G4 (IgG4-related disease with pancreatic and extrapancreatic involvement, including the biliary and renal systems. Given the importance of imaging methods for the diagnosis of IgG4-related disease and its differentiation from pancreatic adenocarcinoma, we emphasize important abdominal computed tomography and magnetic resonance imaging findings related to this recently recognized systemic autoimmune disease.

  18. Development of a colloidal gold-immunochromatography assay to detect immunoglobulin G antibodies to Treponema pallidum with TPN17 and TPN47.

    Science.gov (United States)

    Lin, Li-Rong; Fu, Zuo-Gen; Dan, Bing; Jing, Guang-Jun; Tong, Man-li; Chen, De-Teng; Yu, Yang; Zhang, Chang-Gong; Yang, Tian-Ci; Zhang, Zhong-Ying

    2010-11-01

    Syphilis remains a worldwide public health problem; it is necessary to develop a new diagnostic approach that is easier and faster than conventional tests. Here, we report a new testing method named colloidal gold-immunochromatography assay (GICA) to detect syphilis instead of fluorescent treponemal antibody-absorption (FTA-Abs). Syphilis-specific immunoglobulin G (IgG) antibody was detected with GICA established on syphilis-specific recombinant proteins, TPN17 and TPN47. FTA-Abs Treponema pallidum (TP)-IgG was set as the gold standard. A GICA test was performed to detect the serum of 14 967 subjects who took a serologic test for syphilis at the Xiamen Center of Clinical Laboratory, Fujian, China, from March 2009 to February 2010, among which 1326 cases were diagnosed as syphilitic. The results showed that the sensitivity, specificity, and positive predictive value were 99.38% (1279/1287), 99.96% (12,975/12,980), and 99.61% (1279/1284), respectively. The positive rate between the 2 test methods had no significant difference (χ(2) = 0.003, P > 0.05). Detection on 500 interference specimens indicated that the biologic false-positive rate of the GICA test was extremely low and free from other biologic and chemical factors. The characteristics of GICA TP-IgG correspond to that of FTA-Abs TP-IgG (EUROIMMUN Medizinische Labordiagnostika, Germany). The GICA test is convenient, fast, and inexpensive, and it can be used both as a confirmatory test and a screening indicator, instead of FTA-Abs TP-IgG. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Reducing false asystole alarms in intensive care.

    Science.gov (United States)

    Dekimpe, Remi; Heldt, Thomas

    2017-07-01

    High rates of false monitoring alarms in intensive care can desensitize staff and therefore pose a significant risk to patient safety. Like other critical arrhythmia alarms, asystole alarms require immediate attention by the care providers as a true asystole event can be acutely life threatening. Here, it is illustrated that most false asystole alarms can be attributed to poor signal quality, and we propose and evaluate an algorithm to identify data windows of poor signal quality and thereby help suppress false asystole alarms. The algorithm combines intuitive signal-quality features (degree of signal saturation and baseline wander) and information from other physiological signals that might be available. Algorithm training and testing was performed on the MIMIC II and 2015 PhysioNet/Computing in Cardiology Challenge databases, respectively. The algorithm achieved an alarm specificity of 81.0% and sensitivity of 95.4%, missing only one out of 22 true asystole alarms. On a separate neonatal data set, the algorithm was able to reject 89.7% (890 out of 992) of false asystole alarms while keeping all 22 true events. The results show that the false asystole alarm rate can be significantly reduced through basic signal quality evaluation.

  20. False memories in social anxiety disorder

    Directory of Open Access Journals (Sweden)

    PRISCILA DE CAMARGO PALMA

    Full Text Available Abstract Background False memories are memories of events that never occurred or that occurred, but not exactly as we recall. Events with emotional content are subject to false memories production similar to neutral events. However, individual differences, such as the level of maladjustment and emotional instability characteristics of Social Anxiety Disorder (SAD, may interfere in the production of false memories. Objectives This study aimed to assess the effect of emotion in memory performance for an event witnessed by participants with and without SAD. Methods Participants were 61 young adults with SAD and 76 without any symptoms of SAD who were randomly assigned to watch a story with or without emotional arousal. Participants answered a subjective scale of emotion about the story and a recognition memory test. Results Participants with SAD recovered more true memories and more false memories for the non-emotional version compared to the emotional version of the story. Overall, participants with SAD produced fewer false memories compared to those without SAD. Discussion This finding suggests that social anxiety may have a significant impact on emotional memory accuracy, which may assist in the development and improvement of techniques for therapeutic intervention.

  1. Remedies by competitors for false advertising.

    Science.gov (United States)

    Hirsch, B D; Wilcox, D P

    1990-05-01

    Patients who are victimized as a consequence of false medical advertising are not the only ones who can sue for damages. Under section 43(a) of the Lanham Act, effective November 17, 1989, anyone "who believes that he or she is or is likely to be damaged" by deceptive advertising may bring a civil action for damages (1). Competing physicians may sue other physicians who falsely advertise that they possess unique skills and achieve better results than other physicians because they employ exclusive methods of treatment or claim that certain surgical procedures they perform in the office are absolutely safe and without risk or who advertise false professional credentials to lure patients. Voluntary informed consent excludes the use of deceit. Misrepresentation through advertising deprives a patient of the right to exercise an informed consent (2). A patient who relies on a doctor's false advertising in agreeing to a procedure that causes the patient injury may sue for malpractice even if the procedure was performed without negligence. False medical advertising also exposes the advertiser to litigation by competitors for unfair competition. This article is concerned with the remedy that may be available for instituting private litigation against physicians and other health care providers who engage in untruthful advertising.

  2. False memories and memory confidence in borderline patients.

    Science.gov (United States)

    Schilling, Lisa; Wingenfeld, Katja; Spitzer, Carsten; Nagel, Matthias; Moritz, Steffen

    2013-12-01

    Mixed results have been obtained regarding memory in patients with borderline personality disorder (BPD). Prior reports and anecdotal evidence suggests that patients with BPD are prone to false memories but this assumption has to been put to firm empirical test, yet. Memory accuracy and confidence was assessed in 20 BPD patients and 22 healthy controls using a visual variant of the false memory (Deese-Roediger-McDermott) paradigm which involved a negative and a positive-valenced picture. Groups did not differ regarding veridical item recognition. Importantly, patients did not display more false memories than controls. At trend level, borderline patients rated more items as new with high confidence compared to healthy controls. The results tentatively suggest that borderline patients show uncompromised visual memory functions and display no increased susceptibility for distorted memories. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Sample Size Calculation for Controlling False Discovery Proportion

    Directory of Open Access Journals (Sweden)

    Shulian Shang

    2012-01-01

    Full Text Available The false discovery proportion (FDP, the proportion of incorrect rejections among all rejections, is a direct measure of abundance of false positive findings in multiple testing. Many methods have been proposed to control FDP, but they are too conservative to be useful for power analysis. Study designs for controlling the mean of FDP, which is false discovery rate, have been commonly used. However, there has been little attempt to design study with direct FDP control to achieve certain level of efficiency. We provide a sample size calculation method using the variance formula of the FDP under weak-dependence assumptions to achieve the desired overall power. The relationship between design parameters and sample size is explored. The adequacy of the procedure is assessed by simulation. We illustrate the method using estimated correlations from a prostate cancer dataset.

  4. Pluto behaving badly: false beliefs and their consequences.

    Science.gov (United States)

    Berkowitz, Shari R; Laney, Cara; Morris, Erin K; Garry, Maryanne; Loftus, Elizabeth F

    2008-01-01

    We exposed college students to suggestive materials in order to lead them to believe that, as children, they had a negative experience at Disneyland involving the Pluto character. A sizable minority of subjects developed a false belief or memory that Pluto had uncomfortably licked their ear. Suggestions about a positive experience with Pluto led to even greater acceptance of a lovable ear-licking episode. False beliefs and memories had repercussions; those seduced by the bad suggestions were not willing to pay as much for a Pluto souvenir. These findings are among the first to demonstrate that false beliefs can have repercussions for people, meaning that they can influence their later thoughts, beliefs, and behaviors.

  5. False iliac artery aneurysm following renal transplantation

    DEFF Research Database (Denmark)

    Levi, N; Sønksen, Jens Otto Reimers; Schroeder, T V

    1999-01-01

    We report a very rare case of a false iliac artery aneurysm following renal transplantation. The patient was a 51-year-old women who presented with a painful 10 x 10 cm pulsating mass in her left iliac fossa. The patient had received a second cadaveric renal transplantation 5 years previously....... The graft never functioned and transplant nephrectomy was performed 2 weeks later. A CT-scanning showed a 10 x 10 cm large aneurysm arising from the left external iliac artery. At operation a large false aneurysm was identified arising from the original transplant anastomotic site. Due to the extent...

  6. False memory and the associative network of happiness.

    Science.gov (United States)

    Koo, Minkyung; Oishi, Shigehiro

    2009-02-01

    This research examines the relationship between individuals' levels of life satisfaction and their associative networks of happiness. Study 1 measured European Americans' degree of false memory of happiness using the Deese-Roediger-McDermott paradigm. Scores on the Satisfaction With Life Scale predicted the likelihood of false memory of happiness but not of other lure words such as sleep . In Study 2, European American participants completed an association-judgment task in which they judged the extent to which happiness and each of 15 positive emotion terms were associated with each other. Consistent with Study 1's findings, chronically satisfied individuals exhibited stronger associations between happiness and other positive emotion terms than did unsatisfied individuals. However, Koreans and Asian Americans did not exhibit such a pattern regarding their chronic level of life satisfaction (Study 3). In combination, results suggest that there are important individual and cultural differences in the cognitive structure and associative network of happiness.

  7. False recollection of emotional pictures in Alzheimer's disease.

    Science.gov (United States)

    Gallo, David A; Foster, Katherine T; Wong, Jessica T; Bennett, David A

    2010-10-01

    Alzheimer's Disease (AD) can reduce the effects of emotional content on memory for studied pictures, but less is known about false memory. In healthy adults, emotionally arousing pictures can be more susceptible to false memory effects than neutral pictures, potentially because emotional pictures share conceptual similarities that cause memory confusions. We investigated these effects in AD patients and healthy controls. Participants studied pictures and their verbal labels, and then picture recollection was tested using verbal labels as retrieval cues. Some of the test labels had been associated with a picture at study, whereas other had not. On this picture recollection test, we found that both AD patients and controls incorrectly endorsed some of the test labels that had not been studied with pictures. These errors were associated with medium to high levels of confidence, indicating some degree of false recollection. Critically, these false recollection judgments were greater for emotional compared to neutral items, especially for positively valenced items, in both AD patients and controls. Dysfunction of the amygdala and hippocampus in early AD may impair recollection, but AD did not disrupt the effect of emotion on false recollection judgments. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Discrete emotion-congruent false memories in the DRM paradigm.

    Science.gov (United States)

    Bland, Cassandra E; Howe, Mark L; Knott, Lauren

    2016-08-01

    Research has shown that false-memory production is enhanced for material that is emotionally congruent with the mood of the participant at the time of encoding. So far this research has only been conducted to examine the influence of generic negative affective mood states and generic negative stimuli on false-memory production. In addition, much of the research is limited as it focuses on valence and arousal dimensions, and fails to take into account the more comprehensive nature of emotions. The current study demonstrates that this effect goes beyond general negative or positive moods and acts at a more discrete emotional level. Participants underwent a standard emotion-induction procedure before listening to negative emotional or neutral associative word lists. The emotions induced, negative word lists, and associated nonpresented critical lures, were related to either fear or anger, 2 negative valence emotions that are also both high in arousal. Results showed that when valence and arousal are controlled for, false memories are more likely to be produced for discrete emotionally congruent compared with incongruent materials. These results support spreading activation theories of false remembering and add to our understanding of the adaptive nature of false-memory production. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. Confabulation versus experimentally induced false memories in Korsakoff patients.

    Science.gov (United States)

    Van Damme, Ilse; d'Ydewalle, Géry

    2010-09-01

    The present study focuses on both the clinical symptom of confabulation and experimentally induced false memories in patients suffering from Korsakoff's syndrome. Despite the vast amount of case studies of confabulating patients and studies investigating false memories in the Deese-Roediger-McDermott (DRM) paradigm, the nature of Korsakoff patients' confabulatory behaviour and its association with DRM false memories have been rarely examined. Hence, the first aim of the present study was to evaluate confabulatory responses in a large sample of chronic Korsakoff patients and matched controls by means of the Dalla Barba Confabulation Battery. Second, the association between (provoked) confabulation and the patients' DRM false recognition performance was investigated. Korsakoff patients mainly confabulated in response to questions about episodic memory and questions to which the answer was unknown. A positive association was obtained between confabulation and the tendency to accept unstudied distractor words as being old in the DRM paradigm. On the other hand, there was a negative association between confabulation and false recognition of critical lures. The latter could be attributed to the importance of strategic retrieval at delayed memory testing.

  10. Acute effects of triazolam on false recognition.

    Science.gov (United States)

    Mintzer, M Z; Griffiths, R R

    2000-12-01

    Neuropsychological, neuroimaging, and electrophysiological techniques have been applied to the study of false recognition; however, psychopharmacological techniques have not been applied. Benzodiazepine sedative/anxiolytic drugs produce memory deficits similar to those observed in organic amnesia and may be useful tools for studying normal and abnormal memory mechanisms. The present double-blind, placebo-controlled repeated measures study examined the acute effects of orally administered triazolam (Halcion; 0.125 and 0.25 mg/70 kg), a benzodiazepine hypnotic, on performance in the Deese (1959)/Roediger-McDermott (1995) false recognition paradigm in 24 healthy volunteers. Paralleling previous demonstrations in amnesic patients, triazolam produced significant dose-related reductions in false recognition rates to nonstudied words associatively related to studied words, suggesting that false recognition relies on normal memory mechanisms impaired in benzodiazepine-induced amnesia. The results also suggested that relative to placebo, triazolam reduced participants' reliance on memory for item-specific versus list-common semantic information and reduced participants' use of remember versus know responses.

  11. Development of the False-Memory Illusion

    Science.gov (United States)

    Brainerd, C. J.; Forrest, T. J.; Karibian, D.; Reyna, V. F.

    2006-01-01

    The counterintuitive developmental trend in the Deese-Roediger-McDermott (DRM) illusion (that false-memory responses increase with age) was investigated in learning-disabled and nondisabled children from the 6- to 14-year-old age range. Fuzzy-trace theory predicts that because there are qualitative differences in how younger versus older children…

  12. No effect of stress on false recognition.

    Science.gov (United States)

    Beato, María Soledad; Cadavid, Sara; Pulido, Ramón F; Pinho, María Salomé

    2013-02-01

    The present study aimed to analyze the effect of acute stress on false recognition in the Deese/Roediger-McDermott (DRM) paradigm. In this paradigm, lists of words associated with a non-presented critical lure are studied and, in a subsequent memory test, critical lures are often falsely remembered. In two experiments, participants were randomly assigned to either the stress group (Trier Social Stress Test) or the no-stress control group. Because we sought to control the level-of-processing at encoding, in Experiment 1, participants created a visual mental image for each presented word (deep encoding). In Experiment 2, participants performed a shallow encoding (to respond whether each word contained the letter "o"). The results indicated that, in both experiments, as predicted, heart rate and STAI-S scores increased only in the stress group. However, false recognition did not differ across stress and no-stress groups. Results suggest that, although psychosocial stress was successfully induced, it does not enhance the vulnerability of individuals with acute stress to DRM false recognition, regardless of the level of processing.

  13. COMPARATIVE EFFICACY OF NEEM (Azadirachta indica), FALSE ...

    African Journals Online (AJOL)

    Osondu

    Abstract. A study to evaluate the insecticidal properties of some plants was undertaken. Powder and aqueous extracts of Neem, Azadirachta indica, False sesame, Ceratotheca sesamoides and the Physic nut, Jatropha curcas were evaluated as grain protectants against the cowpea seed beetle, Callosobruchus maculatus.

  14. Production of sensitivity and false alarm rate

    International Nuclear Information System (INIS)

    Han Zijie; Kang Wu; Chu Chengsheng; Hao Fanhua; Liu Xiaoya; Cao Lin; Hu Yongbo; Gong Jian; Xiang Yongchun; Zhang Jianhua; Yang Xiangdong

    2007-01-01

    The false alarm rate and sensitivity in nuclear material monitoring system are affected by alarm principle. Two different alarm principles are studied with theory and experiment analysis in this paper. Our research shows that theory analysis and experiment result are accordant very much. This study provides technology support for designing better alarm principle in nuclear material monitoring system. (authors)

  15. Breast cancer screening: evidence for false reassurance?

    NARCIS (Netherlands)

    R. de Gelder (Rianne); E. As, van (Elisabeth); M.M.A. Tilanus-Linthorst (Madeleine); C.C.M. Bartels (Carina); R. Boer (Rob); G. Draisma (Gerrit); H.J. de Koning (Harry)

    2008-01-01

    textabstractTumour stage distribution at repeated mammography screening is, unexpectedly, often not more favourable than stage distribution at first screenings. False reassurance, i.e., delayed symptom presentation due to having participated in earlier screening rounds, might be associated with

  16. Mapping the Real and the False

    DEFF Research Database (Denmark)

    Kuever, Erika

    2014-01-01

    Purpose -- To show that Chinese consumers are constantly redefining and revaluing goods along the axes of the real and the false, with little regard for legal definitions of brand authenticity or “fakeness.” Findings -- In their everyday consumption practices and navigation of a complex and often...

  17. False elevation of carboxyhemoglobin: case report.

    Science.gov (United States)

    Mehrotra, Shruti; Edmonds, Marcia; Lim, Rodrick K

    2011-02-01

    Carbon monoxide toxicity in infants and children, like adults, produce nonspecific symptoms with normal vital signs necessitating the serum measurement of carboxyhemoglobin (COHb). In infants, the COHb may be falsely elevated. Our goal was to report a case of suspected carbon monoxide toxicity in an infant and the likely cause of the falsely elevated serum COHb. A previously healthy 3-month-old girl presented to the pediatric emergency department (ED) with smoke inhalation from a defective furnace. She was asymptomatic. On examination, she was alert, with Glasgow Coma Scale of 15 and normal vital signs. Cardiorespiratory and neurological examinations were completely normal. Because of concern regarding carbon monoxide poisoning, she was treated with normobaric oxygen therapy. Initial and subsequent serum COHb levels were persistently elevated, despite treatment and the infant appearing clinically well. As such, she had a prolonged stay in the ED. Further investigations found that fetal hemoglobin interferes with the spectrophotometric method used to analyze serum COHb levels. Carboxyhemoglobin serum level, in infants, may be falsely elevated due to the fetal hemoglobin interfering with standard methods of analysis. Knowledge of the false elevation using standard spectrophotometric methods of COHb in clinically well-appearing infants can decrease unnecessary oxygen therapy and monitoring time in the ED.

  18. A Synchronization Account of False Recognition

    Science.gov (United States)

    Johns, Brendan T.; Jones, Michael N.; Mewhort, Douglas J. K.

    2012-01-01

    We describe a computational model to explain a variety of results in both standard and false recognition. A key attribute of the model is that it uses plausible semantic representations for words, built through exposure to a linguistic corpus. A study list is encoded in the model as a gist trace, similar to the proposal of fuzzy trace theory…

  19. Immunoglobulin G4-related tubulointerstitial nephritis: A not to be missed diagnosis

    Directory of Open Access Journals (Sweden)

    Smita Mary Matthai

    2017-01-01

    Full Text Available Immunoglobulin G4-related tubulointerstitial nephritis (IgG4-TIN is a newly recognized clinicopathological entity characterized by a dense interstitial infiltrate of IgG4-positive plasma cells accompanied by fibrosis and obliterative phlebitis causing acute or chronic renal dysfunction amenable to corticosteroid therapy. IgG4-TIN is the dominant manifestation of renal involvement in IgG4-related disease (IgG4-RD which is a novel, immune-mediated, fibroinflammatory and multiorgan disorder. We describe a case of IgG4-TIN with isolated renal involvement in an elderly male patient with poor response to corticosteroid therapy. The distinctive serological, histopathological, and ultrastructural features of this condition which can facilitate differential diagnosis of TIN are highlighted to emphasize the need for early diagnosis and preservation of kidney function.

  20. Membranous glomerulopathy and massive cervical lymphadenopathy due to immunoglobulin G4-disease

    Directory of Open Access Journals (Sweden)

    Kamel El-Reshaid

    2017-01-01

    Full Text Available A 32-year-old male presented with acute and severe nephrotic syndrome as well as massive right cervical lymphadenopathy for <2 years. Computed tomography scan of the chest, abdomen, and pelvis did not reveal any lymphadenopathy. Histopathology and immunohistochemical testing of his lymph node biopsy showed infiltrate enriched with immunoglobulin G4 (IgG4-positive plasma cells. His kidney biopsy showed granular membranous deposits of IgG4 in the basement membrane without interstitial infiltrate. Antiphospholipid 2 receptor antibodies were absent excluding its "idiopathic" nature. Since he was allergic to rituximab, he was treated with corticosteroids for two months and a combination of tacrolimus and mycophenolate. His lymphadenopathy disappeared, and his proteinuria abated. The dose of the latter two medications was reduced to half after four months and will be maintained for a minimum of two years to prevent relapse of his disease.