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Sample records for false positive immunoglobulin

  1. False-positive serology following intravenous immunoglobulin and plasma exchange through transfusion of fresh frozen plasma in a patient with pemphigus vulgaris.

    Science.gov (United States)

    Nomura, Hisashi; Honda, Haruki; Egami, Shohei; Yokoyama, Tomoaki; Fujimoto, Atsushi; Ishikawa, Makiko; Sugiura, Makoto

    2015-04-01

    Intravenous immunoglobulin therapy and plasma exchange through transfusion of fresh frozen plasma are therapeutic options for patients with refractory pemphigus vulgaris. Passive acquisition of various clinically important antibodies through these therapies can occur, leading to false serology and negatively affecting patients' clinical care. It is recommended that dermatologists recognize the possibility of these phenomena and interpret them appropriately. Here, we report false-positive serology following intravenous immunoglobulin therapy and plasma exchange through transfusion of fresh frozen plasma in a patient with refractory pemphigus vulgaris. We also discuss the measure for misinterpretation and unnecessary clinical intervention.

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

    Science.gov (United States)

    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.

  3. The Kepler False Positive Table

    Science.gov (United States)

    Bryson, Steve; Kepler False Positive Working Group

    2015-01-01

    The Kepler Space Telescope has detected thousands of candidate exoplanets by observing transit signals in a sample of more than 190,000 stars. Many of these transit signals are false positives, defined as a transit-like signal that is not due to a planet orbiting the target star (or a bound companion if the target is a multiple-star system). Astrophysical causes of false positives include background eclipsing binaries, planetary transits not associated with the target star, and non-planetary eclipses of the target star by stellar companions. The fraction of Kepler planet candidates that are false positives ranges from about 10% at high Galactic latitudes to 40% at low Galactic latitudes. Creating a high-reliability planet candidate catalog for statistical studies such as occurrence rate calculations requires removing clearly identified false positives.The Kepler Object of Interest (KOI) catalog at the NExScI NASA Exoplanet Archive flags false positives, and will soon provide a high-level classification of false positives, but lacks detailed description of why a KOI was determined to be a false positive. The Kepler False Positive Working Group (FPWG) examines each false positive in detail to certify that it is correctly identified as a false positive, and determines the primary reason(s) a KOI is classified as a false positive. The work of the FPWG will be published as the Kepler False Positive Table, hosted at the NExScI NASA Exoplanet Archive.The Kepler False Positive Table provides detailed information on the evidence for background binaries, transits caused by stellar companions, and false alarms. In addition to providing insight into the Kepler false positive population, the false positive table gives information about the background binary population and other areas of astrophysical interest. Because a planet around a star not associated with the target star is considered a false positive, the false positive table likely contains further planet candidates

  4. False positives in cancer epidemiology.

    Science.gov (United States)

    McLaughlin, Joseph K; Tarone, Robert E

    2013-01-01

    A recent attempt to estimate the false-positive rate for cancer epidemiology studies is based on agents in International Agency for Research on Cancer (IARC) category 3 (agent not classifiable as to its carcinogenicity to humans) in the IARC Monographs Program. The estimation method is critiqued regarding biases caused by its reliance on the IARC classification criteria for assessing carcinogenic potential. The privileged position given to epidemiologic studies by the IARC criteria ensures that the percentage of positive epidemiologic studies for an agent will depend strongly on the IARC category to which the agent is assigned. Because IARC category 3 is composed of agents with the lowest-assessed carcinogenic potential to which the estimation approach in question could be applied, a spuriously low estimated false-positive rate was necessarily the outcome of this approach. Tendentious estimation approaches like that employed will by necessity produce spuriously low and misleading false positive rates. The recently reported estimates of the false-positive rate in cancer epidemiology are seriously biased and contribute nothing substantive to the literature on the very real problems related to false-positive findings in epidemiology.

  5. 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.

  6. False positives in imaging genetics.

    Science.gov (United States)

    Meyer-Lindenberg, Andreas; Nicodemus, Kristin K; Egan, Michael F; Callicott, Joseph H; Mattay, Venkata; Weinberger, Daniel R

    2008-04-01

    Imaging genetics provides an enormous amount of functional-structural data on gene effects in living brain, but the sheer quantity of potential phenotypes raises concerns about false discovery. Here, we provide the first empirical results on false positive rates in imaging genetics. We analyzed 720 frequent coding SNPs without significant association with schizophrenia and a subset of 492 of these without association with cognitive function. Effects on brain structure (using voxel-based morphometry, VBM) and brain function, using two archival imaging tasks, the n-back working memory task and an emotional face matching task, were studied in whole brain and regions of interest and corrected for multiple comparisons using standard neuroimaging procedures. Since these variants are unlikely to impact relevant brain function, positives obtained provide an upper empirical estimate of the false positive association rate. In a separate analysis, we randomly permuted genotype labels across subjects, removing any true genotype-phenotype association in the data, to derive a lower empirical estimate. At a set correction level of 0.05, in each region of interest and data set used, the rate of positive findings was well below 5% (0.2-4.1%). There was no relationship between the region of interest and the false positive rate. Permutation results were in the same range as empirically derived rates. The observed low rates of positives provide empirical evidence that the type I error rate is well controlled by current commonly used correction procedures in imaging genetics, at least in the context of the imaging paradigms we have used. In fact, our observations indicate that these statistical thresholds are conservative.

  7. Controlling False Positives in Association Rule Mining

    CERN Document Server

    Liu, Guimei; Wong, Limsoon

    2011-01-01

    Association rule mining is an important problem in the data mining area. It enumerates and tests a large number of rules on a dataset and outputs rules that satisfy user-specified constraints. Due to the large number of rules being tested, rules that do not represent real systematic effect in the data can satisfy the given constraints purely by random chance. Hence association rule mining often suffers from a high risk of false positive errors. There is a lack of comprehensive study on controlling false positives in association rule mining. In this paper, we adopt three multiple testing correction approaches---the direct adjustment approach, the permutation-based approach and the holdout approach---to control false positives in association rule mining, and conduct extensive experiments to study their performance. Our results show that (1) Numerous spurious rules are generated if no correction is made. (2) The three approaches can control false positives effectively. Among the three approaches, the permutation...

  8. False positive reduction for lung nodule CAD

    Science.gov (United States)

    Zhao, Luyin; Boroczky, Lilla; Drysdale, Jeremy; Agnihotri, Lalitha; Lee, Michael C.

    2007-03-01

    Computer-aided detection (CAD) algorithms 'automatically' identify lung nodules on thoracic multi-slice CT scans (MSCT) thereby providing physicians with a computer-generated 'second opinion'. While CAD systems can achieve high sensitivity, their limited specificity has hindered clinical acceptance. To overcome this problem, we propose a false positive reduction (FPR) system based on image processing and machine learning to reduce the number of false positive lung nodules identified by CAD algorithms and thereby improve system specificity. To discriminate between true and false nodules, twenty-three 3D features were calculated from each candidate nodule's volume of interest (VOI). A genetic algorithm (GA) and support vector machine (SVM) were then used to select an optimal subset of features from this pool of candidate features. Using this feature subset, we trained an SVM classifier to eliminate as many false positives as possible while retaining all the true nodules. To overcome the imbalanced nature of typical datasets (significantly more false positives than true positives), an intelligent data selection algorithm was designed and integrated into the machine learning framework, thus further improving the FPR rate. Three independent datasets were used to train and validate the system. Using two datasets for training and the third for validation, we achieved a 59.4% FPR rate while removing one true nodule on the validation datasets. In a second experiment, 75% of the cases were randomly selected from each of the three datasets and the remaining cases were used for validation. A similar FPR rate and true positive retention rate was achieved. Additional experiments showed that the GA feature selection process integrated with the proposed data selection algorithm outperforms the one without it by 5%-10% FPR rate. The methods proposed can be also applied to other application areas, such as computer-aided diagnosis of lung nodules.

  9. A closer look at self-reported suicide attempts: false positives and false negatives.

    Science.gov (United States)

    Plöderl, Martin; Kralovec, Karl; Yazdi, Kurosch; Fartacek, Reinhold

    2011-02-01

    The validity of self-reported suicide attempt information is undermined by false positives (e.g., incidences without intent to die), or by unreported suicide attempts, referred to as false negatives. In a sample of 1,385 Austrian adults, we explored the occurrence of false positives and false negatives with detailed, probing questions. Removing false positives decreased the rate of suicide attempters from 4.3% to 2.7%. Probing questions also revealed 0.8% false negatives. We recommend using probing questions with both those who report a suicide attempt and those who do not report a suicide attempt to increase the validity of self-reported suicide-related information.

  10. Consequences of a false-positive mammography result

    DEFF Research Database (Denmark)

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

    2016-01-01

    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 of ...

  11. False positive test results for pheochromocytoma from 2000 to 2008.

    Science.gov (United States)

    Yu, R; Wei, M

    2010-10-01

    Testing for pheochromocytoma becomes more frequent in clinical practice. False positive test results may cause patient anxiety and unnecessary imaging studies. The data on false positive results for pheochromocytoma in routine clinical practice are lacking. To examine the prevalence of false positive results and to reveal the clinical features and laboratory tests of patients with markedly elevated but false positive test results, a database of tests for pheochromocytoma at a large general hospital between 2000 and 2008 was reviewed. Of 1,896 patients tested, 417 (22.0%) had at least one abnormal test result and 66 (3.5%) had markedly elevated results. 24 patients with markedly elevated but false positive results received 65 imaging studies and 1 adrenalectomy. The causes of the misleading results included physiological variations (33%), laboratory errors (29%), and drug interference with measurement (21%). The false positive rate of a markedly elevated result was lowest for vanillylmandelic acid (9%) and highest for urine metanephrines (50%) (p = 0.03). Nearly half of all test results were normal and 79% of patients had at least one normal result. Therefore false positive test results for pheochromocytoma are rather common. Markedly elevated but false positive test results can potentially be avoided by judicious selection of patients and tests. Pretest risk, physiological variations of catecholamine levels, laboratory errors, and drug interference should be considered in interpreting abnormal test results. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

  12. Improving retouched Bloom filter for trading off selected false positives against false negatives

    OpenAIRE

    Donnet, Benoît; Baynat, Bruno; Friedman, Timur

    2010-01-01

    Where distributed agents must share voluminous set membership information, Bloom fil- ters provide a compact, though lossy, way for them to do so. Numerous recent networking papers have examined the trade-offs between the bandwidth consumed by the transmis- sion of Bloom filters, and the error rate, which takes the form of false positives. This paper is about the retouched Bloom filter (RBF). An RBF is an extension that makes the Bloom fil- ter more flexible by permitting the removal of false...

  13. Characterisation of false-positive observations in botanical surveys

    Directory of Open Access Journals (Sweden)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jung Min; Lee, Hyun Ju; Goo, Jin Mo; Lee, Ho Young; Lee, Jong Jin; Chung, June Key; Im, Jung Gi [Seoul National University Hospital, Seoul (Korea, Republic of)

    2006-03-15

    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.

  15. Escitalopram-Induced Amenorrhea and False Positive Urine Pregnancy Test

    Science.gov (United States)

    Hour, Siv; Gunasekar, Palanikumar; Gray, Caron; Smith, James F.

    2017-01-01

    Escitalopram is a selective serotonin reuptake inhibitor antidepressant approved by the Food and Drug Administration for the treatment of major depressive disorder and generalized anxiety disorder. A 34-year-old female patient with major depressive disorder developed amenorrhea and had a false-positive urine pregnancy test after initiation of escitalopram treatment. To our knowledge, no published case report of amenorrhea and false-positive urine pregnancy tests in women taking escitalopram exists. This case report suggests that women of child-bearing age should be carefully monitored for amenorrhea while they are on an antidepressant treatment regimen. PMID:28197332

  16. Retouched Bloom Filters: Allowing Networked Applications to Flexibly Trade Off False Positives Against False Negatives

    OpenAIRE

    Donnet, Benoît; Baynat, Bruno; Friedman, Timur

    2006-01-01

    Where distributed agents must share voluminous set mem- bership information, Bloom filters provide a compact, though lossy, way for them to do so. Numerous recent networking papers have examined the trade-offs between the bandwidth consumed by the transmission of Bloom filters, and the er- ror rate, which takes the form of false positives, and which rises the more the filters are compressed. In this paper, we introduce the retouched Bloom filter (RBF), an extension that makes the Bloom filter...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... between those of women withnormal mammography and those of women determined to have breast cancer. CONCLUSIONS: We found no evidence that use of more invasive diagnosticswas associated with worse psychosocial consequences. It is therefore reasonableto pool subgroups of women with false...

  18. 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...

  19. High false positive rates in common sensory threshold tests.

    Science.gov (United States)

    Running, Cordelia A

    2015-02-01

    Large variability in thresholds to sensory stimuli is observed frequently even in healthy populations. Much of this variability is attributed to genetics and day-to-day fluctuation in sensitivity. However, false positives are also contributing to the variability seen in these tests. In this study, random number generation was used to simulate responses in threshold methods using different "stopping rules": ascending 2-alternative forced choice (AFC) with 5 correct responses; ascending 3-AFC with 3 or 4 correct responses; staircase 2-AFC with 1 incorrect up and 2 incorrect down, as well as 1 up 4 down and 5 or 7 reversals; staircase 3-AFC with 1 up 2 down and 5 or 7 reversals. Formulas are presented for rates of false positives in the ascending methods, and curves were generated for the staircase methods. Overall, the staircase methods generally had lower false positive rates, but these methods were influenced even more by number of presentations than ascending methods. Generally, the high rates of error in all these methods should encourage researchers to conduct multiple tests per individual and/or select a method that can correct for false positives, such as fitting a logistic curve to a range of responses.

  20. 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…

  1. 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…

  2. Reducing False Positives in Runtime Analysis of Deadlocks

    Science.gov (United States)

    Bensalem, Saddek; Havelund, Klaus; Clancy, Daniel (Technical Monitor)

    2002-01-01

    This paper presents an improvement of a standard algorithm for detecting dead-lock potentials in multi-threaded programs, in that it reduces the number of false positives. The standard algorithm works as follows. The multi-threaded program under observation is executed, while lock and unlock events are observed. A graph of locks is built, with edges between locks symbolizing locking orders. Any cycle in the graph signifies a potential for a deadlock. The typical standard example is the group of dining philosophers sharing forks. The algorithm is interesting because it can catch deadlock potentials even though no deadlocks occur in the examined trace, and at the same time it scales very well in contrast t o more formal approaches to deadlock detection. The algorithm, however, can yield false positives (as well as false negatives). The extension of the algorithm described in this paper reduces the amount of false positives for three particular cases: when a gate lock protects a cycle, when a single thread introduces a cycle, and when the code segments in different threads that cause the cycle can actually not execute in parallel. The paper formalizes a theory for dynamic deadlock detection and compares it to model checking and static analysis techniques. It furthermore describes an implementation for analyzing Java programs and its application to two case studies: a planetary rover and a space craft altitude control system.

  3. False positive and false negative radon measurement results due to uncertainties in seasonal correction factors

    Energy Technology Data Exchange (ETDEWEB)

    Cliff, K.D.; Miles, J.C.H.; Naismith, S.P. [National Radiological Protection Board, Chilton (United Kingdom)

    1994-12-31

    Data from the UK national survey of radon in 2300 homes has been re-analysed to determine the uncertainty in seasonal correction factors applied to measurements of less than 1 year. The required correction factor for each six-month result was calculated from the known annual average for the appropriate home. The seasonal correction factors derived for each month were found to be approximately log-normally distributed, with an average geometric standard deviation of 1.36. Following this initial survey, radon measurements have been made in more than 80,000 homes in southwest England to determine whether they are above the UK radon Action Level of 2000 Bq.m{sup -3}. The measurements were carried out over three months in each case using etched track detectors in two locations in each home, and the results were corrected for the average seasonal variation found in the original UK study of radon in homes. Because of the uncertainty in the seasonal correction factors, households with between 130 and 300 Bq.m{sup -3} were advised to have a second three-month measurement in a different season before deciding whether or not to take remedial action. More than 7000 homes were remonitored for this purpose. The results are analysed to show the number of false positive and false negative results that would have been reported if advice had been based solely on the initial measurement. It is shown that the present scheme results in extremely small numbers of false positive and false negative results. (author).

  4. False positives to confusable objects predict medial temporal lobe atrophy.

    Science.gov (United States)

    Kivisaari, Sasa L; Monsch, Andreas U; Taylor, Kirsten I

    2013-09-01

    Animal models agree that the perirhinal cortex plays a critical role in object recognition memory, but qualitative aspects of this mnemonic function are still debated. A recent model claims that the perirhinal cortex is required to recognize the novelty of confusable distractor stimuli, and that damage here results in an increased propensity to judge confusable novel objects as familiar (i.e., false positives). We tested this model in healthy participants and patients with varying degrees of perirhinal cortex damage, i.e., amnestic mild cognitive impairment and very early Alzheimer's disease (AD), with a recognition memory task with confusable and less confusable realistic object pictures, and from whom we acquired high-resolution anatomic MRI scans. Logistic mixed-model behavioral analyses revealed that both patient groups committed more false positives with confusable than less confusable distractors, whereas healthy participants performed comparably in both conditions. A voxel-based morphometry analysis demonstrated that this effect was associated with atrophy of the anteromedial temporal lobe, including the perirhinal cortex. These findings suggest that also the human perirhinal cortex recognizes the novelty of confusable objects, consistent with its border position between the hierarchical visual object processing and medial temporal lobe memory systems, and explains why AD patients exhibit a heightened propensity to commit false positive responses with inherently confusable stimuli.

  5. Gallbladder tuberculosis: False-positive PET diagnosis of gallbladder cancer

    Institute of Scientific and Technical Information of China (English)

    JM Ramia; K Muffak; A Fernández; J Villar; D Garrote; JA Ferron

    2006-01-01

    Gallbladder tuberculosis (GT) is an extremely rare disease, and very few cases have been reported in the literature. The first case of GT was described in 1870 by Gaucher. A correct preoperative diagnosis of GT is unusual, and it is frequently confused with various gallbladder diseases. We present a new case of a patient who underwent surgery with the preoperative diagnosis of gallbladder cancer after a false positive positron emission tomography scan in the diagnostic work-up.

  6. False-positive colorimetric capnometry after ingestion of carbonated beverages.

    Science.gov (United States)

    Keller, William Ryan; Biehler, Jefrey; Linares, Marc Yves-Rene; Garcia-Pena, Barbara M

    2009-02-01

    To investigate the potential for false-positive colorimetric capnometric readings during esophageal intubation after ingestion of carbonated beverages. The study was conducted in the human patient simulation laboratory of a tertiary care pediatric hospital. The sole outcome measurement was the capnometric indicator membrane color after expiration for 10 breaths. Readings were recorded for scenarios simulating 8 different models. For all carbonated beverage trials with a cuffed endotracheal tube (ETT) and those with 2 and 6 oz of beverage in the gastric sac with an uncuffed ETT, a false-positive result was observed on the capnometer's indicator for breaths 1 through 10. The sensitivity of the capnometer for the detection of CO2 after full exhalation of breath 6 for these trials was 100%. For trials containing 12 oz in the gastric sac and an uncuffed ETT, yellow was observed on the capnometer indicator for breaths 1 through 3, tan for breaths 4 through 6, and purple for breath 7. The sensitivity of the capnometer for the detection of adequate CO2 after full exhalation of breath 6 for these trials was 0%. The overall sensitivity of the capnometer for the carbonated beverage models with a cuffed ETT was 100%, whereas the combined sensitivity for the trials with an uncuffed ETT was 67%. Under proper circumstances, a significant potential exists for false-positive colorimetric capnometric results in the presence of even small amounts of carbonated beverages.

  7. "False Positive" Claims of Near-Death Experiences and "False Negative" Denials of Near-Death Experiences

    Science.gov (United States)

    Greyson, Bruce

    2005-01-01

    Some persons who claim to have had near-death experiences (NDEs) fail research criteria for having had NDEs ("false positives"); others who deny having had NDEs do meet research criteria for having had NDEs ("false negatives"). The author evaluated false positive claims and false negative denials in an organization that promotes near-death…

  8. The false-positive to false-negative ratio in epidemiologic studies.

    Science.gov (United States)

    Ioannidis, John P A; Tarone, Robert; McLaughlin, Joseph K

    2011-07-01

    The ratio of false-positive to false-negative findings (FP:FN ratio) is an informative metric that warrants further evaluation. The FP:FN ratio varies greatly across different epidemiologic areas. In genetic epidemiology, it has varied from very high values (possibly even >100:1) for associations reported in candidate-gene studies to very low values (1:100 or lower) for associations with genome-wide significance. The substantial reduction over time in the FP:FN ratio in human genome epidemiology has corresponded to the routine adoption of stringent inferential criteria and comprehensive, agnostic reporting of all analyses. Most traditional fields of epidemiologic research more closely follow the practices of past candidate gene epidemiology, and thus have high FP:FN ratios. Further, FP and FN results do not necessarily entail the same consequences, and their relative importance may vary in different settings. This ultimately has implications for what is the acceptable FP:FN ratio and for how the results of published epidemiologic studies should be presented and interpreted.

  9. Abort Trigger False Positive and False Negative Analysis Methodology for Threshold-Based Abort Detection

    Science.gov (United States)

    Melcher, Kevin J.; Cruz, Jose A.; Johnson Stephen B.; Lo, Yunnhon

    2015-01-01

    This paper describes a quantitative methodology for bounding the false positive (FP) and false negative (FN) probabilities associated with a human-rated launch vehicle abort trigger (AT) that includes sensor data qualification (SDQ). In this context, an AT is a hardware and software mechanism designed to detect the existence of a specific abort condition. Also, SDQ is an algorithmic approach used to identify sensor data suspected of being corrupt so that suspect data does not adversely affect an AT's detection capability. The FP and FN methodologies presented here were developed to support estimation of the probabilities of loss of crew and loss of mission for the Space Launch System (SLS) which is being developed by the National Aeronautics and Space Administration (NASA). The paper provides a brief overview of system health management as being an extension of control theory; and describes how ATs and the calculation of FP and FN probabilities relate to this theory. The discussion leads to a detailed presentation of the FP and FN methodology and an example showing how the FP and FN calculations are performed. This detailed presentation includes a methodology for calculating the change in FP and FN probabilities that result from including SDQ in the AT architecture. To avoid proprietary and sensitive data issues, the example incorporates a mixture of open literature and fictitious reliability data. Results presented in the paper demonstrate the effectiveness of the approach in providing quantitative estimates that bound the probability of a FP or FN abort determination.

  10. A "false positive" octreoscan in ileal Crohn's disease

    Institute of Scientific and Technical Information of China (English)

    Alberto Fernandez; Olga Tabuenca; Angeles Peteiro

    2008-01-01

    We present a case report of a patient with a suspicious ileal carcinoid turnout.Clinical examination as well as computer tomograghy (CT) scan suggested a tumour.Octeotride scan showed uptake in the same bowel loop reported as pathological in CT.The patient underwent surgery and biopsy which reported Crohn's disease (CD).The interest in the case is due to the fact that this is,to the best of our knowledge,the second report of Crohn's disease as a cause of false positive octeotride scan.Unfortunately,no somatostatin recptors could be found in the sample,so further studies should be performed.

  11. On the Low False Positive Probabilities of Kepler Planet Candidates

    CERN Document Server

    Morton, Timothy D

    2011-01-01

    We present a framework to conservatively estimate the probability that any particular planet-like transit signal observed by the Kepler mission is in fact a planet, prior to any ground-based follow-up efforts. We use Monte Carlo methods based on stellar population synthesis and Galactic structure models, and we provide empirical analytic fits to our results that may be applied to the as-yet-unconfirmed Kepler candidates. We find that the false positive probability for candidates that pass preliminary Kepler vetting procedures is generally 20% to < 2%, assuming a continuous power law for the planet mass function with index alpha = -1.5. Since Kepler will detect many more planetary signals than can be positively confirmed with ground-based follow-up efforts in the near term, these calculations will be crucial to using the ensemble of Kepler data to determine population characteristic s of planetary systems.

  12. 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.

  13. False positivity of gamma-glutamyl transpeptidase measurement in urine.

    Science.gov (United States)

    Crivellenti, Leandro Zuccolotto; Mesa, Javier Sousa; Meirelles, Adriana Érica Wilkes Burton; Borin Crivellenti, Sofia; Mireya, Edna Gomes; Canola, Julio Carlos; Hatayde, Mário Roberto; Santana, Aureo Evangelista; Dantas, Márcio; Silva, Gyl Eanes Barros

    2014-05-01

    Although enzymuria tends to be associated to renal injury, there are no studies that have evaluated the presence of the enzyme gamma-glutamyl transpeptidase (GGT) spectrophotometry in the urine using a non-nephrotoxic agent (Nerium oleander) in order to evaluate the possibility of false positive results. The urinary GGT/urinary creatinine concentration ratio (uGGT/uCr) of 10 healthy dogs was calculated and posteriorly confronted with data from clinical evaluation, hematological and serum biochemical profiles, creatinine clearance (CrC), urinalysis, urine protein/creatinine ratio (UPC), electrocardiogram, systemic blood pressure (SBP) and light and electron microscopy. The results for kidney histology, SBP, UPC and CrC were not significantly different in any of the time-points analyzed. However, uGGT/uCr was significantly higher when measured 4 hours and 24 hours after administration of N. oleander. The measurement of the urinary GGT enzyme, as performed in many studies, yielded false positive results in dogs poisoned by a non-nephrotoxic agent.

  14. Multiple myeloma as a major cause of false-positive galactomannan tests in adult patients with cancer.

    Science.gov (United States)

    Ko, Jae-Hoon; Peck, Kyong Ran; Lee, Ji Yong; Cho, Sun Young; Ha, Young Eun; Kang, Cheol-In; Chung, Doo Ryeon; Kim, Kihyun; Kang, Eun-Suk; Song, Jae-Hoon

    2016-02-01

    The galactomannan (GM) test is a useful method for early diagnosis of invasive aspergillosis. Recently, multiple myeloma has newly been suggested to be related to false-positive results of GM. We performed a case-control study to validate this finding. Electronic medical records were reviewed for patients admitted March through June 2014. Patients with false-positive GM results were selected as cases and those with negatives as controls. To verify the results of the four-month analysis, additional analysis was performed in multiple myeloma patients over a three-year period. There were 30 false-positive and 316 negative cases during the four-month period. Among the factors evaluated, multiple myeloma was the only significant factor in the adjusted analysis (OR = 3.59, CI 1.28-10.04). In the three-year analysis of 145 multiple myeloma patients, 25.5% showed false-positive results, which was 3 times higher than overall. GM false-positivity was not related to serum monoclonal protein level or type of immunoglobulin. GM optical density indexes (ODIs) in all false positives were lower than 3.0. Multiple myeloma was a major cause of GM false-positivity in adult cancer patients. GM was false-positive in 25.5% of multiple myeloma patients with GM ODIs lower than 3.0. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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

    2013-11-15

    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 related to differences in FIT sensitivity and specificity or to differences in prior CRC risk. Randomly selected, asymptomatic individuals were invited to undergo colonoscopy. Participants were asked to undergo one sample FIT and to complete a risk questionnaire. We identified patient characteristics associated with a false negative and false positive FIT results using logistic regression. We focused on statistically significant differences as well as on variables influencing the false positive or negative risk for which the odds ratio exceeded 1.25. Of the 1,426 screening participants, 1,112 (78%) completed FIT and the questionnaire; 101 (9.1%) had advanced neoplasia. 102 Individuals were FIT positive, 65 (64%) had a false negative FIT result and 66 (65%) a false positive FIT result. Participants at higher age and smokers had a significantly higher risk of a false negative FIT result. Males were at increased risk of a false positive result, so were smokers and regular NSAID users. FIT sensitivity was lower in females. Specificity was lower for males, smokers and regular NSAID users. FIT sensitivity was lower in women. FIT specificity was lower in males, smokers and regular NSAID users. Our results can be used for further evidence based individualization of screening strategies.

  16. 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.

  17. Ross syndrome with ANA positivity: A clue to possible autoimmune origin and treatment with intravenous immunoglobulin

    Directory of Open Access Journals (Sweden)

    Vasudevan Biju

    2010-01-01

    Full Text Available A 28-year-old serving soldier presented with patchy areas of absence of sweating and blurring of vision. On examination he was found to have segmental anhidrosis, right sided tonic pupil and absent ankle jerks. Investigations revealed ANA positivity with no other abnormalities. He was treated with Intravenous immunoglobulin. This case of Ross syndrome is reported for its rarity as well as a clue to its probable autoimmune origin and treatment option with intravenous immunoglobulins.

  18. Pre-Spectroscopic False Positive Elimination of Kepler Planet Candidates

    CERN Document Server

    Batalha, N M; Gilliland, R L; Jenkins, J J; Caldwell, D A; Borucki, W J; Koch, D G; Lissauer, J J; Dunham, E W; Gautier, T N; Howell, S B; Latham, D W; Marcy, G W; Prsa, A

    2010-01-01

    Ten days of commissioning data (Quarter 0) and thirty-three days of science data (Quarter 1) yield instrumental flux timeseries of ~150,000 stars that were combed for transit events, termed Threshold Crossing Events (TCE), each having a total detection statistic above 7.1-sigma. TCE light curves are modeled as star+planet systems. Those returning a companion radius smaller than 2R_J are assigned a KOI (Kepler Object of Interest) 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 a being a planetary companion. This vetting using Kepler data is referred to as data validation. Herein, we describe the data validation metrics and graphics used to identify viable planet candidates amongst the KOIs. Light curve modeling tests for a) the difference in depth of the odd- versus even-numbered transits, b) evidence of ellipsoidal variations, and c) evidence of a secondary eclipse event at pha...

  19. The molecular mimicry and its possible role in origin of false-positive results in HCV-infection testing

    Directory of Open Access Journals (Sweden)

    Benkovskaya L. K.

    2013-09-01

    Full Text Available The main reason for the false positive results of the detection of antibodies to HCV is considered the unspecific binding of the blood serum immunoglobulins with the components of the test-systems’ immunosorbent, what is observed in various pathologies. When considering the issues of diagnosis, prevention and treatment of infectious diseases examined the impact of antigenic heterogeneity and molecular mimicry. With regarding to hepatitis C this phenomenon more illustrated in terms of pathogenesis, autoimmune, extrahepatic lesions. This does not exclude the influence of antigenic mimicry on the specificity of serological tests for anti-HCV detection. Aim. Estimation the frequency of false-positive reactions of anti-HCV testing in patients with chronic somatic diseases and assessment of the antigenic mimicry’s role in their occurrence. Methods. Total anti-HCV, antibodies to the single viruses’ protein, and false positive sera antibodies’ interaction with microbial origin combinations (mimicrins were determined by ELISA. Mimicrins were separated from the cultural medium after cultivation Staphylococcus aureus, Micobacterium tuberculosis and Candida albicans. Results. Upon detection of anti-HCV in patients with chronic pathologies detected a significant number of false-positive results are more likely in patients with diabetes and among healthy individuals – in pregnant women.The majorities of false positive sera interacted with mimicrins. Conclusions. The antigenic crossings over between mimicrins and antibodies in the structure of false positive sera must be considered during the evaluation of the specific diagnostics’ results in the persons with different pathologic states.

  20. 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 is un...

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

    Science.gov (United States)

    Di, Li; Li, Yan

    2017-06-08

    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; PTB tended to induce false-positive results (OR 30.297; 95%CI 7.069-129.849; PTB (exclude tuberculous meningitis) (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.

  2. Astrophysical false positives in exoplanet transit surveys: why do we need bright stars ?

    CERN Document Server

    Santerne, A; Almenara, J -M; Lethuillier, A; Deleuil, M; Moutou, C

    2013-01-01

    Astrophysical false positives that mimic planetary transit are one of the main limitation to exoplanet transit surveys. In this proceeding, we review the issue of the false positive in transit survey and the possible complementary observations to constrain their presence. We also review the false-positive rate of both Kepler and CoRoT missions and present the basics of the planet-validation technique. Finally, we discuss the interest of observing bright stars, as PLATO 2.0 and TESS will do, in the context of the false positives. According to simulations with the Besan\\c{c}on galactic model, we find that PLATO 2.0 is expected to have less background false positives than Kepler, and thus an even lower false-positive rate.

  3. Development of immunoglobulin lambda-chain-positive B cells, but not editing of immunoglobulin kappa-chain, depends on NF-kappaB signals.

    Science.gov (United States)

    Derudder, Emmanuel; Cadera, Emily J; Vahl, J Christoph; Wang, Jing; Fox, Casey J; Zha, Shan; van Loo, Geert; Pasparakis, Manolis; Schlissel, Mark S; Schmidt-Supprian, Marc; Rajewsky, Klaus

    2009-06-01

    By genetically ablating IkappaB kinase (IKK)-mediated activation of the transcription factor NF-kappaB in the B cell lineage and by analyzing a mouse mutant in which immunoglobulin lambda-chain-positive B cells are generated in the absence of rearrangements in the locus encoding immunoglobulin kappa-chain, we define here two distinct, consecutive phases of early B cell development that differ in their dependence on IKK-mediated NF-kappaB signaling. During the first phase, in which NF-kappaB signaling is dispensable, predominantly kappa-chain-positive B cells are generated, which undergo efficient receptor editing. In the second phase, predominantly lambda-chain-positive B cells are generated whose development is ontogenetically timed to occur after rearrangements of the locus encoding kappa-chain. This second phase of development is dependent on NF-kappaB signals, which can be substituted by transgenic expression of the prosurvival factor Bcl-2.

  4. 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

    INTRODUCTION: There is an ongoing debate concerning possible disadvantages of mammography screening, one being the consequence of receiving a false positive test-result. It is argued that receiving a false positive answer may have short- and/or long-term adverse psychological effects on women, bu...

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

    DEFF Research Database (Denmark)

    Roman, Marta; Castells, Xavier; Hofvind, Solveig

    2016-01-01

    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 ...

  6. 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

    INTRODUCTION: Studies have shown that women with a false-positive result from mammography screening have an excess risk for breast cancer compared with women who only have negative results. We aimed to assess the excess risk of cancer after a false-positive result excluding cases of misclassifica...

  7. CT colonography with computer-aided detection: recognizing the causes of false-positive reader results.

    Science.gov (United States)

    Trilisky, Igor; Wroblewski, Kristen; Vannier, Michael W; Horne, John M; Dachman, Abraham H

    2014-01-01

    Computed tomography (CT) colonography is a screening modality used to detect colonic polyps before they progress to colorectal cancer. Computer-aided detection (CAD) is designed to decrease errors of detection by finding and displaying polyp candidates for evaluation by the reader. CT colonography CAD false-positive results are common and have numerous causes. The relative frequency of CAD false-positive results and their effect on reader performance on the basis of a 19-reader, 100-case trial shows that the vast majority of CAD false-positive results were dismissed by readers. Many CAD false-positive results are easily disregarded, including those that result from coarse mucosa, reconstruction, peristalsis, motion, streak artifacts, diverticulum, rectal tubes, and lipomas. CAD false-positive results caused by haustral folds, extracolonic candidates, diminutive lesions (reader false-positive results. Nondismissable CAD soft-tissue polyp candidates larger than 6 mm are another common cause of reader false-positive results that may lead to further evaluation with follow-up CT colonography or optical colonoscopy. Strategies for correctly evaluating CAD polyp candidates are important to avoid pitfalls from common sources of CAD false-positive results. ©RSNA, 2014.

  8. A Case of Systemic Lupus Erythematosus Associated with False Positive VDRL and TPHA

    Directory of Open Access Journals (Sweden)

    Muzeyyen Gonul

    2008-09-01

    Full Text Available Systemic lupus erythematosus (SLE is a connective tissue disease characterized by vasculitis, which may involve multiple organs as well as the skin. Serologic tests for syphilis may be false positive in SLE. Although the false positivity of VDRL (Venereal Disease Research Laboratory is commonly seen, false positivity of TPHA (Treponema pallidum haemagglutination is a rare condition. We present a case of SLE with false positive VDRL and TPHA. A 26-year-old woman was admitted to our clinic with violaceous papules and plaques with whitish desquamation and erosions, and crusts on the face, arms and back. The histopathological examination of the skin biopsy supported the diagnosis of discoid lupus erythematosus. The diagnosis of SLE was based on the presence of photosensitivity and the detection of leukopenia, anemia and positivities of antinuclear antibody, anti DNA, and VDRL. In addition to these findings, TPHA was found to be positive, but the ELISA test for syphilis and FTA ABS Ig M were negative. The positivity of VDRL and TPHA were accepted as false positives. We would like to point out that the false positivity of TPHA, although more rarely encountered, as well as that of VDRL, may be observed in SLE patients.

  9. Consequences of a false-positive mammography result: drug consumption before and after screening.

    Science.gov (United States)

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

    2016-05-01

    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 of drug use for women with false-positive versus women with normal mammograms, before and after the event, using population-based registers, 1997-2006. The ratio of the ratios (RRR) assessed the impact. Results Before the test, 40.3% of women from the false-positive group versus 36.2% from the normal 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 mammograms already before the screening event, while the changes from before to after screening were similar for both groups. The results point to the importance of control for potential selection in studies of screening effects.

  10. 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...... 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...

  11. Experimental investigation of false positive errors in auditory species occurrence surveys

    Science.gov (United States)

    Miller, David A.W.; Weir, Linda A.; McClintock, Brett T.; Grant, Evan H. Campbell; Bailey, Larissa L.; Simons, Theodore R.

    2012-01-01

    False positive errors are a significant component of many ecological data sets, which in combination with false negative errors, can lead to severe biases in conclusions about ecological systems. We present results of a field experiment where observers recorded observations for known combinations of electronically broadcast calling anurans under conditions mimicking field surveys to determine species occurrence. Our objectives were to characterize false positive error probabilities for auditory methods based on a large number of observers, to determine if targeted instruction could be used to reduce false positive error rates, and to establish useful predictors of among-observer and among-species differences in error rates. We recruited 31 observers, ranging in abilities from novice to expert, that recorded detections for 12 species during 180 calling trials (66,960 total observations). All observers made multiple false positive errors and on average 8.1% of recorded detections in the experiment were false positive errors. Additional instruction had only minor effects on error rates. After instruction, false positive error probabilities decreased by 16% for treatment individuals compared to controls with broad confidence interval overlap of 0 (95% CI: -46 to 30%). This coincided with an increase in false negative errors due to the treatment (26%; -3 to 61%). Differences among observers in false positive and in false negative error rates were best predicted by scores from an online test and a self-assessment of observer ability completed prior to the field experiment. In contrast, years of experience conducting call surveys was a weak predictor of error rates. False positive errors were also more common for species that were played more frequently, but were not related to the dominant spectral frequency of the call. Our results corroborate other work that demonstrates false positives are a significant component of species occurrence data collected by auditory

  12. Immunoglobulin G4-positive multi-organ lymphoproliferative syndrome with antiphospholipid antibody syndrome.

    Science.gov (United States)

    Kawakami, Nobuyo; Kawai, Kazuhiro; Baba, Naoko; Ohshima, Kouichi; Kanekura, Takuro

    2012-07-01

    We report immunoglobulin (Ig)G4-positive multi-organ lymphoproliferative syndrome (IgG4(+) -MOLPS) with antiphospholipid antibody syndrome (APS) in a 56-year-old Japanese man presenting with purpuric patches on his legs. Skin biopsy revealed leukocytoclastic vasculitis. Laboratory tests demonstrated high levels of serum IgG and IgG4, hypocomplementemia and anticardiolipin antibody. Echography of the lower limbs and pulmonary scintigraphy showed a thrombus in the left soleal vein and multiple emboli in the basal part of both inferior pulmonary arteries. Computed tomography revealed systemic lymphadenopathy. Histologically, there was reactive paracortical hyperplasia with proliferation of histiocytes and infiltration of IgG4-positive plasma cells. We made a diagnosis of IgG4(+) -MOLPS with APS. To our knowledge, this complication has not been reported previously.

  13. False-positive interferences of common urine drug screen immunoassays: a review.

    Science.gov (United States)

    Saitman, Alec; Park, Hyung-Doo; Fitzgerald, Robert L

    2014-09-01

    Urine drug screen (UDS) immunoassays are a quick and inexpensive method for determining the presence of drugs of abuse. Many cross-reactivities exist with other analytes, potentially causing a false-positive result in an initial drug screen. Knowledge of these potential interferents is important in determining a course of action for patient care. We present an inclusive review of analytes causing false-positive interferences with drugs-of-abuse UDS immunoassays, which covers the literature from the year 2000 to present. English language articles were searched via the SciFinder platform with the strings 'false positive [drug] urine' yielding 173 articles. These articles were then carefully analyzed and condensed to 62 that included data on causes of false-positive results. The discussion is separated into six sections by drug class with a corresponding table of cross-reacting compounds for quick reference. False-positive results were described for amphetamines, opiates, benzodiazepines, cannabinoids, tricyclic antidepressants, phencyclidine, lysergic acid diethylamide and barbiturates. These false-positive results support the generally accepted practice that immunoassay positive results are considered presumptive until confirmed by a second independent chemical technique.

  14. Frequency of False Positive Amphetamine Screens due to Bupropion Using the Syva Emit II Immunoassay

    OpenAIRE

    Casey, Erica R; Scott, Mitchell G.; Tang, Schirin; Mullins, Michael E.

    2010-01-01

    Bupropion is a commonly prescribed, monocyclic antidepressant often used as an aid for smoking cessation. Several case reports have described false positive amphetamine urine drug screens (UDS) associated with bupropion. We sought to determine whether false positive amphetamine UDS due to the use of bupropion would be a frequent occurrence. We conducted an IRB-approved, retrospective chart review of all emergency department patients who underwent UDS between 1 January 2006 and 31 July 2007. A...

  15. 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.

  16. 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.

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

    Science.gov (United States)

    2008-06-01

    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.

  18. GeneWaltz--A new method for reducing the false positives of gene finding

    Directory of Open Access Journals (Sweden)

    Misawa Kazuharu

    2010-09-01

    Full Text Available Abstract Background Identifying protein-coding regions in genomic sequences is an essential step in genome analysis. It is well known that the proportion of false positives among genes predicted by current methods is high, especially when the exons are short. These false positives are problematic because they waste time and resources of experimental studies. Methods We developed GeneWaltz, a new filtering method that reduces the risk of false positives in gene finding. GeneWaltz utilizes a codon-to-codon substitution matrix that was constructed by comparing protein-coding regions from orthologous gene pairs between mouse and human genomes. Using this matrix, a scoring scheme was developed; it assigned higher scores to coding regions and lower scores to non-coding regions. The regions with high scores were considered candidate coding regions. One-dimensional Karlin-Altschul statistics was used to test the significance of the coding regions identified by GeneWaltz. Results The proportion of false positives among genes predicted by GENSCAN and Twinscan were high, especially when the exons were short. GeneWaltz significantly reduced the ratio of false positives to all positives predicted by GENSCAN and Twinscan, especially when the exons were short. Conclusions GeneWaltz will be helpful in experimental genomic studies. GeneWaltz binaries and the matrix are available online at http://en.sourceforge.jp/projects/genewaltz/.

  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. 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.

  1. False Positive Results of Carpal tunnel syndrome in Electro Diagnosis Tests

    Directory of Open Access Journals (Sweden)

    MR Emad

    2010-07-01

    Full Text Available Introduction & Objective: Carpal tunnel syndrome is identified due to compression of median nerve at wrist and develops symptoms such as wrist pain, paresthesia, numbness and the dysfunction of the hands. The gold standard to diagnose, determining prognosis and planning treatment process based on the severity of nerve involvement are electro-diagnosis tests. The purpose of this study was to specify the least and the most false positive results in common electro-diagnosis tests. Materials & Methods: This descriptive study was conducted at Shiraz University of Medical Sciences in 2009. Twelve different electro-diagnosis tests on fifty-five normal cases (110 available hands, which never had experienced the symptoms of this syndrome, were carried out. The data was statistically analyzed by SPSS software, using T test and Cochran's `Q. Results: There were false positive results in many of the performed tests. The most false-positive result was in- difference between median and ulnar motor distal latencies- test with the rate of 15.5% and the lowest false positive result was in- difference between median and ulnar sensory distal latencies of digit 4- test with the rate of 0%. Conclusion: This study revealed that tests which evaluate the differences between median and ulnar or radial nerves sensory distal latency (in the finger 4 and or 1, respectively, had less false positive results, and are more reliable in suspected cases of this syndrome. Also by using several different electro-diagnostic tests, rapid and efficient diagnosis can be achieved.

  2. Receipt of a false positive test result during routine screening for ovarian cancer: a teachable moment?

    Science.gov (United States)

    Floyd, Andrea; Steffens, Rachel F; Pavlik, Edward; Andrykowski, Michael A

    2011-03-01

    The term "teachable moment" (TM) has been used to describe a life transition or event which motivates an individual to change a behavior or presents an opportunity to intervene to prompt behavior change. We examined whether receipt of a false positive ovarian cancer (OC) screening result may represent a TM. 403 women participating in an OC screening program completed questionnaires assessing demographic, clinical, behavioral, and psychosocial information. The TM was operationalized as expressed interest in receiving health-related information. We hypothesized that among women receiving a false positive screening test result, those women who had experienced greater personal perceived risk for OC as well as distress would be more interested in receiving health-related information than women receiving a normal result. Analyses revealed that women receiving a false positive screening result were less interested in receiving health-related information than women receiving a normal screening result. For women receiving a false positive result, expressed interest in receipt of health-related information was only modestly related to distress and related even less to perceptions of OC risk. Our data do not support viewing a false positive OC screening result as a TM. Potential explanations for the current findings as well as recommendations for future research investigating the TM are discussed.

  3. 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.

  4. 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.

  5. False positive malaria rapid diagnostic test in returning traveler with typhoid fever.

    Science.gov (United States)

    Meatherall, Bonnie; Preston, Keith; Pillai, Dylan R

    2014-07-09

    Rapid diagnostic tests play a pivotal role in the early diagnosis of malaria where microscopy or polymerase chain reaction are not immediately available. We report the case of a 39 year old traveler to Canada who presented with fever, headache, and abdominal pain after visiting friends and relatives in India. While in India, the individual was not ill and had no signs or symptoms of malaria. Laboratory testing upon his return to Canada identified a false positive malaria rapid diagnostic (BinaxNOW® malaria) result for P. falciparum with coincident Salmonella Typhi bacteraemia without rheumatoid or autoimmune factors. Rapid diagnostic test false positivity for malaria coincided with the presence or absence of Salmonella Typhi in the blood. Clinicians should be aware that Salmonella Typhi infection may result in a false positive malaria rapid diagnostic test. The mechanism of this cross-reactivity is not clear.

  6. Case Reports of Aripiprazole Causing False-Positive Urine Amphetamine Drug Screens in Children.

    Science.gov (United States)

    Kaplan, Justin; Shah, Pooja; Faley, Brian; Siegel, Mark E

    2015-12-01

    Urine drug screens (UDSs) are used to identify the presence of certain medications. One limitation of UDSs is the potential for false-positive results caused by cross-reactivity with other substances. Amphetamines have an extensive list of cross-reacting medications. The literature contains reports of false-positive amphetamine UDSs with multiple antidepressants and antipsychotics. We present 2 cases of presumed false-positive UDSs for amphetamines after ingestion of aripiprazole. Case 1 was a 16-month-old girl who accidently ingested 15 to 45 mg of aripiprazole. She was lethargic and ataxic at home with 1 episode of vomiting containing no identifiable tablets. She remained sluggish with periods of irritability and was admitted for observation. UDS on 2 consecutive days came back positive for amphetamines. Case 2 was of a 20-month-old girl who was brought into the hospital after accidental ingestion of an unknown quantity of her father's medications which included aripiprazole. UDS on the first day of admission came back positive only for amphetamines. Confirmatory testing with gas chromatography-mass spectrometry (GC-MS) on the blood and urine samples were also performed for both patients on presentation to detect amphetamines and were subsequently negative. Both patients returned to baseline and were discharged from the hospital. To our knowledge, these cases represent the first reports of false-positive amphetamine urine drug tests with aripiprazole. In both cases, aripiprazole was the drug with the highest likelihood of causing the positive amphetamine screen. The implications of these false-positives include the possibility of unnecessary treatment and monitoring of patients.

  7. Research: Association of Low-Amplitude QRSs with False-Positive Asystole Alarms.

    Science.gov (United States)

    Pelter, Michele M; Fidler, Richard; Hu, Xiao

    2016-01-01

    Although electrocardiographic monitoring is valuable for continuous surveillance of intensive care unit (ICU) patients, false alarms are common and have been cited as a cause of alarm fatigue. ANSI/AAMI EC12:2002 states that electrocardiograms (ECGs) should not detect a QRS if the waveform is less than 0.15 mV (1.5 mm) for adult patients, in order to avoid mislabeling P waves or baseline noise as QRSs during complete heart block or asystole. However, ECG software algorithms often use more conservative QRS thresholds, which may result in false-positive asystole alarms in patients with low-amplitude QRS complexes. To 1) assess the frequency of low QRS amplitude in a group of ICU patients with one or more false-positive asystole alarms and 2) determine whether low-amplitude QRSs are associated with false-positive asystole alarms during continuous ECG monitoring. Hospital-acquired standard 12-lead ECGs were examined in a group of 82 ICU patients who had one or more false-positive asystole alarms. Low QRS amplitude was defined as a unidirectional (only positive or negative) QRS of less than 5 mm in two of four leads (I, II, III, and V1). Low-amplitude QRSs were present in 45 of 82 (55%) patients. The presence of low-amplitude QRSs did not differ according to age, sex, or race. Patients treated in the cardiac ICU had the highest proportion of low-amplitude QRSs. An equivalent proportion of patients had false-positive asystole alarms by group (no low-amplitude QRSs 95% vs. low-amplitude QRSs 87%; P = 0.229). Eight patients (10%) had both true- and false-positive asystole alarms (two [5%] with no low-amplitude QRSs and six [13%] with low-amplitude QRSs; P = 0.229). Low-amplitude QRS, as assessed from hospital 12-lead ECGs, occurs frequently and is more common in cardiac ICU patients. However, this ECG feature did not identify patients with false-positive asystole alarms during continuous ECG monitoring.

  8. False positive diagnosis on (131)iodine whole-body scintigraphy of differentiated thyroid cancers.

    Science.gov (United States)

    Triggiani, Vincenzo; Giagulli, Vito Angelo; Iovino, Michele; De Pergola, Giovanni; Licchelli, Brunella; Varraso, Antonio; Dicembrino, Franca; Valle, Guido; Guastamacchia, Edoardo

    2016-09-01

    (131)Iodine is used both to ablate any residual thyroid tissue or metastatic disease and to obtain whole-body diagnostic images after total thyroidectomy for differentiated thyroid cancer (DTC). Even though whole-body scan is highly accurate in showing thyroid residues as well as metastases of DTC, false positive results can be found, possibly leading to diagnostic errors and unnecessary treatments. This paper reviews the physiological and pathological processes involved as well as the strategy to recognize and rule out false positive radioiodine images.

  9. 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...

  10. The rapid plasma reagin (circle) card test in biological false positive and leprosy sera

    Science.gov (United States)

    Garner, M. F.; Backhouse, J. L.

    1972-01-01

    The rapid plasma reagin (RPR) circle card and the Venereal Disease Reference Laboratory (VDRL) slide test results were compared on a group of sera known to show biological false positive (BFP) reactions to reagin detection tests for syphilis. The RPR test was more specific than the VDRL test on the sera selected, ie, it gave fewer false positive results than the VDRL test. However, in a group of presumed normal sera, the RPR test gave BFP reactions while the VDRL test gave none. The RPR test gave fewer BFP reactions than the VDRL test in 269 sera from patients with lepromatous leprosy. PMID:5086221

  11. 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.

  12. Does replication groups scoring reduce false positive rate in SNP interaction discovery?

    Directory of Open Access Journals (Sweden)

    Demsar Janez

    2010-01-01

    Full Text Available Abstract Background Computational methods that infer single nucleotide polymorphism (SNP interactions from phenotype data may uncover new biological mechanisms in non-Mendelian diseases. However, practical aspects of such analysis face many problems. Present experimental studies typically use SNP arrays with hundreds of thousands of SNPs but record only hundreds of samples. Candidate SNP pairs inferred by interaction analysis may include a high proportion of false positives. Recently, Gayan et al. (2008 proposed to reduce the number of false positives by combining results of interaction analysis performed on subsets of data (replication groups, rather than analyzing the entire data set directly. If performing as hypothesized, replication groups scoring could improve interaction analysis and also any type of feature ranking and selection procedure in systems biology. Because Gayan et al. do not compare their approach to the standard interaction analysis techniques, we here investigate if replication groups indeed reduce the number of reported false positive interactions. Results A set of simulated and false interaction-imputed experimental SNP data sets were used to compare the inference of SNP-SNP interactions by means of replication groups to the standard approach where the entire data set was directly used to score all candidate SNP pairs. In all our experiments, the inference of interactions from the entire data set (e.g. without using the replication groups reported fewer false positives. Conclusions With respect to the direct scoring approach the utility of replication groups does not reduce false positive rates, and may, depending on the data set, often perform worse.

  13. False memory for positive and negative life events. The role of mental imagery

    Directory of Open Access Journals (Sweden)

    Mairean, C.

    2015-07-01

    Full Text Available A false memory appears when a person recalls memories of events that did not actually happen to him or her. The present study focused on situational and personal determinants of spontaneous false memories. Specifically, we aimed to investigate the role of emotional valence of an event, as well as the individual differences in mental imagery in evocation false memory. Three videos in which related details were not shown but were presented during a recognition task were used to induce spontaneous false memories. The three videos are different in terms of valence, reflecting positive, negative and neutral events. A scale for measuring mental imagery was also used. A sample of 132 participants completed the study. The results showed that the positive event lead to a higher level of false memory than the negative event. Moreover, the participants differ in their susceptibility to false memories based on the level of imagery, but the interaction between the emotional valence of the event and mental imagery is not significant. The results are discussed from the perspective of their legal and clinical implications.

  14. 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

  15. EMPLOYING TOPOGRAPHICAL HEIGHT MAP IN COLONIC POLYP MEASUREMENT AND FALSE POSITIVE REDUCTION.

    Science.gov (United States)

    Yao, Jianhua; Li, Jiang; Summers, Ronald M

    2009-01-01

    CT Colonography (CTC) is an emerging minimally invasive technique for screening and diagnosing colon cancers. Computer Aided Detection (CAD) techniques can increase sensitivity and reduce false positives. Inspired by the way radiologists detect polyps via 3D virtual fly-through in CTC, we borrowed the idea from geographic information systems to employ topographical height map in colonic polyp measurement and false positive reduction. After a curvature based filtering and a 3D CT feature classifier, a height map is computed for each detection using a ray-casting algorithm. We design a concentric index to characterize the concentric pattern in polyp height map based on the fact that polyps are protrusions from the colon wall and round in shape. The height map is optimized through a multi-scale spiral spherical search to maximize the concentric index. We derive several topographic features from the map and compute texture features based on wavelet decomposition. We then send the features to a committee of support vector machines for classification. We have trained our method on 394 patients (71 polyps) and tested it on 792 patients (226 polyps). Results showed that we can achieve 95% sensitivity at 2.4 false positives per patient and the height map features can reduce false positives by more than 50%. We compute the polyp height and width measurements and correlate them with manual measurements. The Pearson correlations are 0.74 (p=0.11) and 0.75 (p=0.17) for height and width, respectively.

  16. 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 limited...

  17. Predicting the risk of a false-positive test for women following a mammography screening programme

    DEFF Research Database (Denmark)

    Njor, Sisse Helle; Olsen, Anne Helene; Schwartz, Walter

    2007-01-01

    OBJECTIVES: The objectives of this study was to provide a simple estimate of the cumulative risk of a false-positive test for women participating in mammography screening. To test the method, we used data from two well-established, organized mammography screening programmes offering biennial...... be calculated in a simple way relatively early after the start of a mammography screening programme....

  18. Factors Associated With False-Positive Emergency Medical Services Triage for Percutaneous Coronary Intervention

    Directory of Open Access Journals (Sweden)

    Yamamoto Swan, Pamela

    2009-11-01

    Full Text Available Background: In 2005, Orange County California Emergency Medical Services (EMS initiated a field 12-lead program to minimize time to emergency percutaneous coronary intervention (PCI for field-identified acute myocardial infarction (MI. As the program matured, “false-positive” (defined as no PCI or coronary artery occlusion upon PCI field MI activations have been identified as a problem for the program.Objectives: To identify potentially correctable factors associated with false-positive EMS triage to PCI centers.Methods: This was a retrospective, outcome study of EMS 12-lead cases from February 2006 to June 2007. The study system exclusively used cardiac monitor internal interpretation algorithms indicating an acute myocardial infarction as the basis for triage. Indicators and variables were defined prior to the study. Data, including outcome, was from the Orange County EMS database, which included copies of 12-lead ECGs used for field triage. Negative odds ratios (OR of less than 1.0 for positive PCI were the statistical measure of interest.Results: Five hundred forty-eight patients were triaged from the field for PCI. We excluded 19 cases from the study because of death prior to PCI, refusal of PCI, and co-morbid illness (sepsis, altered consciousness that precluded PCI. Three hundred ninety-three (74.3% patients had PCI with significant coronary lesions found. False-positive field triages were associated with underlying cardiac rhythm of sinus tachycardia [OR = 0.38 (95% CI 0.23, 0.62]; atrial fibrillation [OR = 0.43 (95% CI = 0.20, 0.94]; an ECG lead not recorded [OR = 0.39 (95% CI = 0.20, 0.76]; poor ECG baseline [OR = 0.59 (95% CI = 0.25, 1.37]; One of three brands of monitors used in the field [OR = 0.35 (95% CI = 0.21, 0.59]; and female gender [OR = 0.50 (95% CI = 0.34, 0.75]. Age was not associated with false-positive triage as determined by ordinal regression (p=1.00.Conclusion: For the urban-suburban EMS field 12-lead program

  19. Copy-number variation and false positive prenatal aneuploidy screening results.

    Science.gov (United States)

    Snyder, Matthew W; Simmons, LaVone E; Kitzman, Jacob O; Coe, Bradley P; Henson, Jessica M; Daza, Riza M; Eichler, Evan E; Shendure, Jay; Gammill, Hilary S

    2015-04-23

    Investigations of noninvasive prenatal screening for aneuploidy by analysis of circulating cell-free DNA (cfDNA) have shown high sensitivity and specificity in both high-risk and low-risk cohorts. However, the overall low incidence of aneuploidy limits the positive predictive value of these tests. Currently, the causes of false positive results are poorly understood. We investigated four pregnancies with discordant prenatal test results and found in two cases that maternal duplications on chromosome 18 were the likely cause of the discordant results. Modeling based on population-level copy-number variation supports the possibility that some false positive results of noninvasive prenatal screening may be attributable to large maternal copy-number variants. (Funded by the National Institutes of Health and others.).

  20. Risk of Breast Cancer in Women with False-Positive Results according to Mammographic Features.

    Science.gov (United States)

    Castells, Xavier; Torá-Rocamora, Isabel; Posso, Margarita; Román, Marta; Vernet-Tomas, Maria; Rodríguez-Arana, Ana; Domingo, Laia; Vidal, Carmen; Baré, Marisa; Ferrer, Joana; Quintana, María Jesús; Sánchez, Mar; Natal, Carmen; Espinàs, Josep A; Saladié, Francina; Sala, María

    2016-08-01

    Purpose To assess the risk of breast cancer in women with false-positive screening results according to radiologic classification of mammographic features. Materials and Methods Review board approval was obtained, with waiver of informed consent. This retrospective cohort study included 521 200 women aged 50-69 years who underwent screening as part of the Spanish Breast Cancer Screening Program between 1994 and 2010 and who were observed until December 2012. Cox proportional hazards regression analysis was used to estimate the age-adjusted hazard ratio (HR) of breast cancer and the 95% confidence interval (CI) in women with false-positive mammograms as compared with women with negative mammograms. Separate models were adjusted for screen-detected and interval cancers and for screen-film and digital mammography. Time without a breast cancer diagnosis was plotted by using Kaplan-Meier curves. Results When compared with women with negative mammograms, the age-adjusted HR of cancer in women with false-positive results was 1.84 (95% CI: 1.73, 1.95; P < .001). The risk was higher in women who had calcifications, whether they were (HR, 2.73; 95% CI: 2.28, 3.28; P < .001) or were not (HR, 2.24; 95% CI: 2.02, 2.48; P < .001) associated with masses. Women in whom mammographic features showed changes in subsequent false-positive results were those who had the highest risk (HR, 9.13; 95% CI: 8.28, 10.07; P < .001). Conclusion Women with false-positive results had an increased risk of breast cancer, particularly women who had calcifications at mammography. Women who had more than one examination with false-positive findings and in whom the mammographic features changed over time had a highly increased risk of breast cancer. Previous mammographic features might yield useful information for further risk-prediction models and personalized follow-up screening protocols. (©) RSNA, 2016 Online supplemental material is available for this article.

  1. Herbal medicine and false-positive results on lymphocyte transformation test.

    Science.gov (United States)

    Mantani, Naoki; Sakai, Shinya; Kogure, Toshiaki; Goto, Hirozo; Shibahara, Naotoshi; Kita, Toshiaki; Shimada, Yutaka; Terasawa, Katsutoshi

    2002-06-01

    In vitro mitogenic activity of 16 herbs and 3 Kampo (herbal medicine) formulae have been reported in experimental studies. It is not known how many herbs and Kampo formulae in total have mitogenic activity. Lymphocyte transformation test (LTT) is generally utilized to diagnose drug-induced liver injury. In LTT, mitogenic activity is assessed by measuring 3H-thymidine incorporation. The objective of the present study was to determine which herbs and which Kampo formulae caused false-positivity on LTT. We examined 2496 summaries of all admission records from 1979 to 1999 in our department. We selected patients in whom liver injuries were diagnosed as definitely unrelated to Kampo medication. In these patients, LTT was performed for some herbs contained in the suspect Kampo medicines, resulting in positive LTT for 17 herbs: Evodiae Fructus (Goshuyu), Zizyphi Fructus (Taiso), Ginseng Radix (Ninjin), Zingiberis Rhizoma (Shokyo), Hoelen (Bukuryo), Aconiti Tuber (Bushi), Angelicae Radix (Toki), Cnidii Rhizoma (Senkyu), Rehmanniae Radix (Jio), Ephedrae Herba (Mao), Anemarrhenae Rhizoma (Chimo), Cinnamomi Cortex (Keihi), Bupleuri Radix (Saiko), Artemisiae Capillari Spica (Inchinko), Persicae Semen (Tonin), Moutan Cortex (Botanpi) and Paeoniae Radix (Shakuyaku). These results were considered false-positive, because the results were observed in the "definitely unrelated" patients. Mitogenic activity inherent to some herbs and Kampo formulae may sometimes cause false-positivity on LTT in clinical situations. These examples suggest that LTT for Kampo formulae may be unreliable as a diagnostic method for drug-induced liver injury.

  2. 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

  3. High false-positive rate of questionnaire-based restless legs syndrome diagnosis in multiple sclerosis.

    Science.gov (United States)

    Mery, V; Kimoff, R J; Suarez, I; Benedetti, A; Kaminska, M; Robinson, A; Lapierre, Y; Bar-Or, A; Trojan, D A

    2015-07-01

    Restless legs syndrome (RLS) is diagnosed by self-reported symptoms. Multiple sclerosis (MS) patients have disease-related symptoms which could mimic RLS. This study assessed the: (1) false-positive rate for questionnaire-based RLS diagnosis in MS patients and (2) utility of periodic leg movements during wakefulness (PLMW) on overnight polysomnography (PSG) in identifying true-positive RLS patients. Ambulatory MS patients without known sleep disorders were recruited. Subjects completed the International RLS Study Group (IRLSG) diagnostic questionnaire (IRLDQ) and underwent full overnight PSG. IRLDQ-positive patients underwent clinical evaluation to confirm the diagnosis and completed the RLS severity scale (IRLS). Seventy-one MS patients (mean age 46.8 ± 10.4 years) were evaluated. Thirty-eight had a positive IRLDQ. RLS diagnosis was confirmed in 22, yielding a false-positive rate of 42% [95% confidence interval (CI) 26-59%], predominantly attributable to paresthesiae (n = 7), and cramps and/or muscle spasms (n = 4). IRLS scores were not significantly different between subjects with confirmed and nonconfirmed RLS. The PLMW index was significantly higher in patients with confirmed RLS (55.4 ± 41.9 vs. 29.7 ± 18.8, p = 0.03). The sensitivity of a PLMW index >70/h for true-positive IRLDQ was 8/22 = 36%, 95% CI: 17.2-59.3, and the specificity was 16/16 = 100%, 95% CI: 79.4-100. MS patients have a high false-positive rate of RLS diagnosis using a standardized questionnaire largely attributable to MS-related sensorimotor symptoms. While detailed clinical evaluation is essential for confirming RLS diagnosis, the PLMW index may provide useful adjunctive information. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. False Positives and Referral Bias: Content for a Quantitative Literacy Course

    Directory of Open Access Journals (Sweden)

    Stuart Boersma

    2008-07-01

    Full Text Available An extended study of accuracy in medical screening is presented as a useful application to increase students’ quantitative reasoning skills. Two detailed examples are presented. The first explores the frequency of obtaining false positive results from a medical screening tool while the second examines the issue of referral bias and its effect on the apparent sensitivity and specificity of the screening tool. Results from student assessments indicate that the activity increases one’s ability to define terms such as “false positive” and “false negative” and increases one’s ability to read and compute with information obtained from a two-way table. Teacher assessment results indicate that the activity is challenging and could be used in existing high school or college classrooms. Additionally, links to a student activity, instructor notes, and Excel calculation tool are provided.

  5. Doxylamine toxicity: seizure, rhabdomyolysis and false positive urine drug screen for methadone.

    Science.gov (United States)

    Syed, Husnain; Som, Sumit; Khan, Nazia; Faltas, Wael

    2009-01-01

    The present report highlights the possible adverse effects of doxylamine, a common over the counter sleep aid. Doxylamine is an antihistamine that at toxic doses can cause anticholinergic effects, including seizures, rhabdomyolysis and death. The following case describes a patient with doxylamine toxicity who presented with seizure and confusion. Our patient was managed symptomatically, and remained otherwise stable throughout his hospitalisation. This case is atypical in terms of a delayed rhabdomyolysis and a false positive urine drug screen test for methadone. There is evidence that doxylamine at toxic levels can lead to false positives for methadone and phencyclidine testing using immunoassay-based urine drug screen kits. Urine drug screen testing on patients who are hospitalised is typically performed using immunoassays. However, in certain cases confirmatory secondary testing may be required. Doxylamine is prone to abuse and knowledge of the clinical presentation of its toxicity and the management of acute overdose can be life-saving.

  6. Chromosomes Emission of Planet Candidate Host Stars: A Way to Identify False Positives

    Science.gov (United States)

    Karoff, Christoffer; Albrecht, Simon; Bonanno, Alfio; Faurschou Knudsen, Mads

    2016-10-01

    It has been hypothesized that the presence of closely orbiting giant planets is associated with enhanced chromospheric emission of their host stars. The main cause for such a relation would likely be enhanced dynamo action induced by the planet. We present measurements of chromospheric emission in 234 planet candidate systems from the Kepler mission. This ensemble includes 37 systems with giant-planet candidates, which show a clear emission enhancement. The enhancement, however, disappears when systems that are also identified as eclipsing binary candidates are removed from the ensemble. This suggests that a large fraction of the giant-planet candidate systems with chromospheric emission stronger than the Sun are not giant-planet systems, but false positives. Such false-positive systems could be tidally interacting binaries with strong chromospheric emission. This hypothesis is supported by an analysis of 188 eclipsing binary candidates that show increasing chromospheric emission as function of decreasing orbital period.

  7. Chromospheric emission of planet candidate systems - a way to identify false positives

    CERN Document Server

    Karoff, Christoffer; Boxano, Alfio; Knudsen, Mads Faurschou

    2016-01-01

    It has been hypothesized that the presence of closely orbiting giant planets is associated with enhanced chromospheric emission of their host stars. The main cause for such a relation would likely be enhanced dynamo action induced by the planet. We present measurements of chromospheric emission in 234 planet candidate systems from the Kepler mission. This ensemble includes 37 systems with giant planet candidates, which show a clear emission enhancement. The enhancement, however, disappears when systems which are also identified as eclipsing binary candidates are removed from the ensemble. This suggests that a large fraction of the giant planet candidate systems with chromospheric emission stronger than the Sun are not giant planet system, but false positives. Such false-positive systems could be tidally interacting binaries with strong chromospheric emission. This hypotesis is supported by an analysis of 188 eclipsing binary candidates that show increasing chromospheric emission as function of decreasing orbi...

  8. 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

    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...... is only recognized (1) by a negative muscle tissue control that does not harbor the protein to be examined (fx. from knockout mouse) or (2) by use of a nonsense rabbit antibody that has been prepared in the same way as the antibody of interest. However, many muscle immuno(cyto/histo)chemical studies only...... 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...

  9. Frequency of false positive amphetamine screens due to bupropion using the Syva EMIT II immunoassay.

    Science.gov (United States)

    Casey, Erica R; Scott, Mitchell G; Tang, Schirin; Mullins, Michael E

    2011-06-01

    Bupropion is a commonly prescribed, monocyclic antidepressant often used as an aid for smoking cessation. Several case reports have described false positive amphetamine urine drug screens (UDS) associated with bupropion. We sought to determine whether false positive amphetamine UDS due to the use of bupropion would be a frequent occurrence. We conducted an IRB-approved, retrospective chart review of all emergency department patients who underwent UDS between 1 January 2006 and 31 July 2007. All urine samples were screened using Syva EMIT II Plus immunoassay reagents. All positive screens underwent confirmation by gas chromatography (GC). We reviewed the records of patients with positive amphetamine UDS. We documented prescription use of bupropion, other antidepressants, stimulants, antipsychotics, and anti-hypertensives. We recorded evidence of polysubstance abuse (PSA) as patients who had had a documented diagnosis or laboratory evidence of abuse of at least two substances (drugs or ethanol). Of 10,011 urine drug screens, 362 (3.6%) were positive for amphetamine. GC confirmed amphetamines in 234 (65%), but failed to confirm in 128 (35%). Among the 234 confirmed, records reflected use of bupropion in three (1.3%), other antidepressants in 38 (16%), antipsychotics in 17 (8%), and amphetamine in 50 (21%). Records indicated evidence of PSA in 55 (24%). Among the 128 which failed to confirm, records reflected prescription use of bupropion in 53 (41%). None whose drug screen failed to confirm had evidence of PSA. Therapeutic use of bupropion appears to be the most frequent cause of false positive urine drug screens for amphetamines in our population.

  10. "Does replication groups scoring reduce false positive rate in SNP interaction discovery?: Response"

    Directory of Open Access Journals (Sweden)

    González-Pérez Antonio

    2010-06-01

    Full Text Available Abstract A response to Toplak et al: Does replication groups scoring reduce false positive rate in SNP interaction discovery? BMC Genomics 2010, 11:58. Background The genomewide evaluation of genetic epistasis is a computationally demanding task, and a current challenge in Genetics. HFCC (Hypothesis-Free Clinical Cloning is one of the methods that have been suggested for genomewide epistasis analysis. In order to perform an exhaustive search of epistasis, HFCC has implemented several tools and data filters, such as the use of multiple replication groups, and direction of effect and control filters. A recent article has claimed that the use of multiple replication groups (as implemented in HFCC does not reduce the false positive rate, and we hereby try to clarify these issues. Results/Discussion HFCC uses, as an analysis strategy, the possibility of replicating findings in multiple replication groups, in order to select a liberal subset of preliminary results that are above a statistical criterion and consistent in direction of effect. We show that the use of replication groups and the direction filter reduces the false positive rate of a study, although at the expense of lowering the overall power of the study. A post-hoc analysis of these selected signals in the combined sample could then be performed to select the most promising results. Conclusion Replication of results in independent samples is generally used in scientific studies to establish credibility in a finding. Nonetheless, the combined analysis of several datasets is known to be a preferable and more powerful strategy for the selection of top signals. HFCC is a flexible and complete analysis tool, and one of its analysis options combines these two strategies: A preliminary multiple replication group analysis to eliminate inconsistent false positive results, and a post-hoc combined-group analysis to select the top signals.

  11. "Does replication groups scoring reduce false positive rate in SNP interaction discovery?: Response"

    Science.gov (United States)

    2010-01-01

    A response to Toplak et al: Does replication groups scoring reduce false positive rate in SNP interaction discovery? BMC Genomics 2010, 11:58. Background The genomewide evaluation of genetic epistasis is a computationally demanding task, and a current challenge in Genetics. HFCC (Hypothesis-Free Clinical Cloning) is one of the methods that have been suggested for genomewide epistasis analysis. In order to perform an exhaustive search of epistasis, HFCC has implemented several tools and data filters, such as the use of multiple replication groups, and direction of effect and control filters. A recent article has claimed that the use of multiple replication groups (as implemented in HFCC) does not reduce the false positive rate, and we hereby try to clarify these issues. Results/Discussion HFCC uses, as an analysis strategy, the possibility of replicating findings in multiple replication groups, in order to select a liberal subset of preliminary results that are above a statistical criterion and consistent in direction of effect. We show that the use of replication groups and the direction filter reduces the false positive rate of a study, although at the expense of lowering the overall power of the study. A post-hoc analysis of these selected signals in the combined sample could then be performed to select the most promising results. Conclusion Replication of results in independent samples is generally used in scientific studies to establish credibility in a finding. Nonetheless, the combined analysis of several datasets is known to be a preferable and more powerful strategy for the selection of top signals. HFCC is a flexible and complete analysis tool, and one of its analysis options combines these two strategies: A preliminary multiple replication group analysis to eliminate inconsistent false positive results, and a post-hoc combined-group analysis to select the top signals. PMID:20576100

  12. "Does replication groups scoring reduce false positive rate in SNP interaction discovery?: Response"

    OpenAIRE

    González-Pérez Antonio; Gayán Javier; Ruiz Agustín

    2010-01-01

    Abstract A response to Toplak et al: Does replication groups scoring reduce false positive rate in SNP interaction discovery? BMC Genomics 2010, 11:58. Background The genomewide evaluation of genetic epistasis is a computationally demanding task, and a current challenge in Genetics. HFCC (Hypothesis-Free Clinical Cloning) is one of the methods that have been suggested for genomewide epistasis analysis. In order to perform an exhaustive search of epistasis, HFCC has implemented several tools ...

  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. 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.

  15. The trazodone metabolite meta-chlorophenylpiperazine can cause false-positive urine amphetamine immunoassay results.

    Science.gov (United States)

    Baron, Jason M; Griggs, David A; Nixon, Andrea L; Long, William H; Flood, James G

    2011-07-01

    Amphetamines and methamphetamines are part of an important class of drugs included in most urine drugs of abuse screening panels, and a common assay to detect these drugs is the Amphetamines II immunoassay (Roche Diagnostics). To demonstrate that meta-chlorophenylpiperazine (m-CPP), a trazodone metabolite, cross-reacts in the Amphetamines II assay, we tested reference standards of m-CPP at various concentrations (200 to 20,000 g/L). We also tested real patient urine samples containing m-CPP (detected and quantified by HPLC) with no detectable amphetamine, methamphetamine, or MDMA (demonstrated by GC MS). In both the m-CPP standards and the patient urine samples, we found a strong association between m-CPP concentration and Amphetamines II immunoreactivity (r = 0.990 for the urine samples). Further, we found that patients taking trazodone can produce urine with sufficient m-CPP to result in false-positive Amphetamines II results. At our institution, false-positive amphetamine results occur not infrequently in patients taking trazodone with at least 8 trazodone-associated false-positive results during a single 26-day period. Laboratories should remain cognizant of this interference when interpreting results of this assay.

  16. False positivity of ETV6/RUNX1 detected by FISH in healthy newborns and adults

    DEFF Research Database (Denmark)

    Kusk, Maria Schioldan; Lausten-Thomsen, Ulrik; Andersen, Mette Klarskov

    2014-01-01

    The leukemia-associated ETV6-RUNX1-translocation frequently emerges prenatally. Reverse-transcriptase PCR screening may indicate presence of ETV6-RUNX1 transcripts in random cord blood samples. Subsequent cell enrichment validation finds significantly lower levels than validation applying...... fluorescence in situ hybridization (FISH) (RUNX1-positive dilution series, healthy adults and random cord blood samples. The t(12;21) single fusion extra signal translocation probe and the ETV6 break apart probe...... gave false positive results mimicking ETV6-RUNX1-positive cell levels of 10(-3). This questions the paradigm that 1% of newborns have ETV6-RUNX1-positive cells at levels of 10(-3) to 10(-4)....

  17. De Novo Hepatitis B Infection From Hepatitis B Core Antibody-Positive Donors During Hepatitis B Immunoglobulin Prophylaxis.

    Science.gov (United States)

    Shin, Milljae; Chang, Seong-Hwan

    2016-02-01

    De novo hepatitis B infection in patients receiving liver transplants from hepatitis B core antibody-positive donors is well known, but the effective prevention strategy has not been well established. In our hospital, recipients receive hepatitis B immunoglobulin monotherapy if they are hepatitis B surface antigen negative at the time of transplant and are receiving a liver from a hepatitis B core antibody-positive donor. Since August 2006, we have had 4 patients who were naïve to hepatitis B virus and received a hepatitis B core antibody-positive graft. Two patients died of other causes, and 2 patients, who had liver transplant in October 2006 and October 2009, developed de novo hepatitis B. Both patients were tested annually for serum hepatitis B surface antigen as part of routine visit. Tests were negative; however, both patients recently became hepatitis B surface antigen positive. Other laboratory results, including liver function test, were unremarkable, except HBsAb titer was undetectable even though hepatitis B immunoglobulin monotherapy had been administrated 2 months previously in both patients. The patients had hepatitis B virus DNA levels of 3.07E+08 copies/mL and 1.51E+08 copies/mL. We suggest that additional prophylactic therapies above hepatitis B immunoglobulin monotherapy are needed for these recipients.

  18. THE FALSE POSITIVE RATE OF KEPLER AND THE OCCURRENCE OF PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Fressin, Francois; Torres, Guillermo; Charbonneau, David; Dressing, Courtney D. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Bryson, Stephen T.; Christiansen, Jessie; Jenkins, Jon M.; Batalha, Natalie M. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Walkowicz, Lucianne M., E-mail: ffressin@cfa.harvard.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2013-04-01

    The Kepler mission is uniquely suited to study the frequencies of extrasolar planets. This goal requires knowledge of the incidence of false positives such as eclipsing binaries in the background of the targets, or physically bound to them, which can mimic the photometric signal of a transiting planet. We perform numerical simulations of the Kepler targets and of physical companions or stars in the background to predict the occurrence of astrophysical false positives detectable by the mission. Using real noise level estimates, we compute the number and characteristics of detectable eclipsing pairs involving main-sequence stars and non-main-sequence stars or planets, and we quantify the fraction of those that would pass the Kepler candidate vetting procedure. By comparing their distribution with that of the Kepler Objects of Interest (KOIs) detected during the first six quarters of operation of the spacecraft, we infer the false positive rate of Kepler and study its dependence on spectral type, candidate planet size, and orbital period. We find that the global false positive rate of Kepler is 9.4%, peaking for giant planets (6-22 R{sub Circled-Plus }) at 17.7%, reaching a low of 6.7% for small Neptunes (2-4 R{sub Circled-Plus }), and increasing again for Earth-size planets (0.8-1.25 R{sub Circled-Plus }) to 12.3%. Most importantly, we also quantify and characterize the distribution and rate of occurrence of planets down to Earth size with no prior assumptions on their frequency, by subtracting from the population of actual Kepler candidates our simulated population of astrophysical false positives. We find that 16.5% {+-} 3.6% of main-sequence FGK stars have at least one planet between 0.8 and 1.25 R{sub Circled-Plus} with orbital periods up to 85 days. This result is a significant step toward the determination of eta-earth, the occurrence of Earth-like planets in the habitable zone of their parent stars. There is no significant dependence of the rates of planet

  19. PET-CT in presurgical lymph node staging in non-small cell lung cancer: the importance of false-negative and false-positive findings.

    Science.gov (United States)

    García de Castro, A Bustos; Domínguez, J Ferreirós; Bolton, R Delgado; Pérez, C Fernández; Martínez, B Cabeza; García-Esquinas, M García; Carreras Delgado, J L

    To assess the importance of false-negative and false-positive findings in computed tomography (CT) and (18)F-FDG positron emission tomography (PET) in mediastinal lymph node staging in patients undergoing surgery for non-small cell lung cancer (NSCLC). This retrospective study included 113 consecutive patients and 120 resected NSCLCs; 22 patients received neoadjuvant treatment. We compared the findings on preoperative (18)F-FDG PET-CT studies with the postoperative pathology findings. Lymph node size and primary tumor size were measured with CT, and lymph nodes and primary tumors were evaluated qualitatively and semiquantitatively (using standardized uptake values (SUVmax)) with PET. Metastatic lymph nodes were found in 26 (21.7%) of the 120 tumors and in 41 (7.7%) of the 528 lymph node stations analyzed. (18)F-FDG PET-CT yielded 53.8% sensitivity, 76.6% specificity, 38.9% positive predictive value, 85.7% negative predictive value, and 71.7% diagnostic accuracy. The false-negative rate was 14.2%. Multivariable analysis found that the factors associated with false-negative findings were a moderate degree of differentiation in the primary tumor (p = 0.005) and an SUVmax of the primary tumor >4 (p = 0.027). The false-positive rate was 61.1%, and the multivariable analysis found that lymph node size >1cm was associated with false-positive findings (p < 0.001). In mediastinal lymph node staging in patients with NSCLC, (18)F-FDG PET-CT improves the specificity and negative predictive value and helps clinicians to select the patients that will benefit from surgery. Given the high rate of false positives, histological confirmation of positive cases is recommendable. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Estimating False Positive Contamination in Crater Annotations from Citizen Science Data

    Science.gov (United States)

    Tar, P. D.; Bugiolacchi, R.; Thacker, N. A.; Gilmour, J. D.

    2017-01-01

    Web-based citizen science often involves the classification of image features by large numbers of minimally trained volunteers, such as the identification of lunar impact craters under the Moon Zoo project. Whilst such approaches facilitate the analysis of large image data sets, the inexperience of users and ambiguity in image content can lead to contamination from false positive identifications. We give an approach, using Linear Poisson Models and image template matching, that can quantify levels of false positive contamination in citizen science Moon Zoo crater annotations. Linear Poisson Models are a form of machine learning which supports predictive error modelling and goodness-of-fits, unlike most alternative machine learning methods. The proposed supervised learning system can reduce the variability in crater counts whilst providing predictive error assessments of estimated quantities of remaining true verses false annotations. In an area of research influenced by human subjectivity, the proposed method provides a level of objectivity through the utilisation of image evidence, guided by candidate crater identifications.

  1. Estimating False Positive Contamination in Crater Annotations from Citizen Science Data

    Science.gov (United States)

    Tar, P. D.; Bugiolacchi, R.; Thacker, N. A.; Gilmour, J. D.

    2016-11-01

    Web-based citizen science often involves the classification of image features by large numbers of minimally trained volunteers, such as the identification of lunar impact craters under the Moon Zoo project. Whilst such approaches facilitate the analysis of large image data sets, the inexperience of users and ambiguity in image content can lead to contamination from false positive identifications. We give an approach, using Linear Poisson Models and image template matching, that can quantify levels of false positive contamination in citizen science Moon Zoo crater annotations. Linear Poisson Models are a form of machine learning which supports predictive error modelling and goodness-of-fits, unlike most alternative machine learning methods. The proposed supervised learning system can reduce the variability in crater counts whilst providing predictive error assessments of estimated quantities of remaining true verses false annotations. In an area of research influenced by human subjectivity, the proposed method provides a level of objectivity through the utilisation of image evidence, guided by candidate crater identifications.

  2. 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 BACKGROUND: 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. METHODOLOGY AND PRINCIPAL FINDINGS: 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. CONCLUSION: 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.

  3. Parathyroid incidentalomas detected during thyroid ultrasonography and effect of chronic thyroiditis on false positive parathyroid lesions.

    Science.gov (United States)

    Ozdemir, Didem; Arpaci, Dilek; Ucler, Rifki; Cuhaci, Neslihan; Ersoy, Reyhan; Cakir, Bekir

    2012-12-01

    We aimed to determine the prevalence of parathyroid incidentalomas in patients referred for thyroid ultrasonography (US) and investigate the role of chronic thyroiditis on false positive lesions. Patients suspected to have parathyroid lesions during thyroid US were recorded prospectively between August 2009 and January 2010. Patients referred for parathyroid US and patients with known high serum calcium or parathyroid hormone (PTH) levels were excluded. Suspected parathyroid lesions were defined as hypoechoic, homogeneous, solid lesions with regular margins located outside the thyroid lobe, most commonly inferior to the thyroid gland. Thyroid US was performed in 6,528 patients. There were 78 patients (1.19 %) (73 female and 5 male) with suspected parathyroid lesion. The diagnosis of a true parathyroid adenoma was confirmed in 6 (7.69 %) patients. In patients with true adenoma, mean serum calcium, phosphorus, and PTH levels were 10.57 ± 0.48 mg/dl, 3.03 ± 0.52 mg/dl, and 182.91 ± 46.62 pg/ml, respectively. Among 72 patients with false positive parathyroid lesion, antithyroid peroxidase antibody was positive in 50 (69.4 %), antithyroglobulin antibody was positive in 46 (63.9 %), and one of these antibodies were positive in 59 (81.9 %) patients. Also, 46 (63.9 %) of these patients had thyroid dysfunctions (43 hypothyroidism and 3 hyperthyroidism) and 59 (81.9 %) had chronic thyroiditis ultrasonographically. Parathyroid incidentaloma was detected in 0.09 % of patients referred for thyroid US. The presence of clinically or ultrasonographically chronic thyroiditis might cause inadvertent interpretation of a hypoechoic lesion as a parathyroid pathology during thyroid US.

  4. 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......, and statistical methods, can explain the reported differences. METHODS: We included all screens from women first screened at age 50-69 years in the US Breast Cancer Surveillance Consortium (BCSC) (n=99,455) between 1996-2010, and from two population-based mammography screening programs in Denmark (n=230,452 and n...

  5. Xanthogranulomatous cholecystitis mimicking gallbladder carcinoma with a false-positive result on fluorodeoxyglucose PET

    Institute of Scientific and Technical Information of China (English)

    Isamu Makino; Takahiro Yamaguchi; Nariatsu Sato; Toshiaki Yasui; Ichiro Kita

    2009-01-01

    Recently, several reports have demonstrated that fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is useful in differentiating between benign and mal ignant lesions in the gallbladder. However, there is a limitation in the ability of FDG-PET to differentiate between inflammatory and malignant lesions. We herein present a case of xanthogranulomatous cholecystitis misdiagnosed as gallbladder carcinoma by ultrasonography and computed tomography. FDG-PET also showed increased activity. In this case, FDG-PET findings resulted in a false-positive for the diagnosis of gallbladder carcinoma.

  6. 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.

  7. False-Positive Clostridium difficile in Negative-Control Reactions Peak and Then Decrease with Repetitive Refrigeration of Immunoassay.

    Science.gov (United States)

    Rodriguez-Palacios, Alexander; Stämpfli, Henry R; Chang, Yung-Fu

    2014-01-01

    Aberrant false-positive reactions in negative-controls during ELISA testing for Clostridium difficile indicated the potential for false-diagnoses. Experiments with 96-well products showed a maximum peak of false-positive immunoassay reactions with the provided negative-control reagents after 5 refrigeration-to-room temperature cycles (P refrigeration cycles. Because repetitive refrigeration causes a peak of false-positives, the use of single negative-controls per ELISA run might be insufficient to monitor aberrant preanalytical false-positives if immunoassays are subject to repetitive refrigeration.

  8. False positive RNA binding activities after Ni-affinity purification from Escherichia coli.

    Science.gov (United States)

    Milojevic, Tetyana; Sonnleitner, Elisabeth; Romeo, Alessandra; Djinović-Carugo, Kristina; Bläsi, Udo

    2013-06-01

    A His-tag is often added by means of recombinant DNA technology to a heterologous protein of interest, which is then over-produced in Escherchia coli and purified by one-step immobilized metal-affinity chromatography (IMAC). Owing to the presence of 24 histidines at the C-termini of the hexameric E. coli RNA chaperone Hfq, the protein co-purifies with His-tagged proteins of interest. As Hfq can bind to distinct RNA substrates with high affinity, its presence can obscure studies performed with (putative) RNA binding activities purified by IMAC. Here, we present results for a seemingly positive RNA-binding activity, exemplifying that false-positive results can be avoided if the protein of interest is either subjected to further purification step(s) or produced in an E. coli hfq- strain.

  9. 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.

  10. False-positive rates associated with the use of multiple performance and symptom validity tests.

    Science.gov (United States)

    Larrabee, Glenn J

    2014-06-01

    Performance validity test (PVT) error rates using Monte Carlo simulation reported by Berthelson and colleagues (in False positive diagnosis of malingering due to the use of multiple effort tests. Brain Injury, 27, 909-916, 2013) were compared with PVT and symptom validity test (SVT) failure rates in two nonmalingering clinical samples. At a per-test false-positive rate of 10%, Monte Carlo simulation overestimated error rates for: (i) failure of ≥2 out of 5 PVTs/SVT for Larrabee (in Detection of malingering using atypical performance patterns on standard neuropsychological tests. The Clinical Neuropsychologist, 17, 410-425, 2003) and ACS (Pearson, Advanced clinical solutions for use with WAIS-IV and WMS-IV. San Antonio: Pearson Education, 2009) and (ii) failure of ≥2 out of 7 PVTs/SVT for Larrabee (Detection of malingering using atypical performance patterns on standard neuropsychological tests. The Clinical Neuropsychologist, 17, 410-425, 2003; Malingering scales for the Continuous Recognition Memory Test and Continuous Visual Memory Test. The Clinical Neuropsychologist, 23, 167-180, 2009 combined). Monte Carlo overestimation is likely because PVT performances are atypical in pattern or degree for what occurs in actual neurologic, psychiatric, or developmental disorders. Consequently, PVT scores form skewed distributions with performance at ceiling and restricted range, rather than forming a standard normal distribution with mean of 0 and standard deviation of 1.0. These results support the practice of using ≥2 PVT/SVT failures as representing probable invalid clinical presentation.

  11. Astrophysical false positives in direct imaging for exoplanets: a white dwarf close to a rejuvenated star

    CERN Document Server

    Zurlo, A; Hagelberg, J; Desidera, S; Chauvin, G; Almenara, J M; Biazzo, K; Bonnefoy, M; Carson, J C; Covino, E; Delorme, P; D'Orazi, V; Gratton, R; Mesa, D; Messina, S; Moutou, C; Segransan, D; Turatto, M; Udry, S; Wildi, F

    2013-01-01

    As is the case for all techniques involved in the research for exoplanets, direct imaging has to take into account the probability of so-called astrophysical false positives, which are phenomena that mimic the signature of objects we are seeking. In this work we aim to present a case of a false positive found during a direct imaging survey conducted with VLT/NACO. A promising exoplanet candidate was detected around the K2-type star HD\\,8049 in July 2010.Its contrast of $\\Delta H$=7.05 at 1.57 arcsec allowed us to guess the presence of a 35 \\MJup companion at 50 projected AU, for the nominal system age and heliocentric distance.To check whether it was gravitationally bound to the host star, as opposed to an unrelated background object, we re-observed the system one year later and concluded a high probability of a bound system. We also used radial velocity measurements of the host star, spanning a time range of $\\sim$ 30 yr, to constrain the companion's mass and orbital properties, as well as to probe the host ...

  12. Pulmonary Nodule Detection in CT Images: False Positive Reduction Using Multi-View Convolutional Networks.

    Science.gov (United States)

    Setio, Arnaud Arindra Adiyoso; Ciompi, Francesco; Litjens, Geert; Gerke, Paul; Jacobs, Colin; van Riel, Sarah J; Wille, Mathilde Marie Winkler; Naqibullah, Matiullah; Sanchez, Clara I; van Ginneken, Bram

    2016-05-01

    We propose a novel Computer-Aided Detection (CAD) system for pulmonary nodules using multi-view convolutional networks (ConvNets), for which discriminative features are automatically learnt from the training data. The network is fed with nodule candidates obtained by combining three candidate detectors specifically designed for solid, subsolid, and large nodules. For each candidate, a set of 2-D patches from differently oriented planes is extracted. The proposed architecture comprises multiple streams of 2-D ConvNets, for which the outputs are combined using a dedicated fusion method to get the final classification. Data augmentation and dropout are applied to avoid overfitting. On 888 scans of the publicly available LIDC-IDRI dataset, our method reaches high detection sensitivities of 85.4% and 90.1% at 1 and 4 false positives per scan, respectively. An additional evaluation on independent datasets from the ANODE09 challenge and DLCST is performed. We showed that the proposed multi-view ConvNets is highly suited to be used for false positive reduction of a CAD system.

  13. Detection of circulating prostate tumor cells: alternative spliced variant of PSM induced false-positive result.

    Science.gov (United States)

    Hisatomi, Hisashi; Nagao, Kumi; Kawakita, Mutsuji; Matsuda, Tadashi; Hirata, Hiroyuki; Yamamoto, Shigeki; Nakamoto, Takaaki; Harasawa, Hiroshi; Kaneko, Noboru; Hikiji, Kazumasa; Tsukada, Yutaka

    2002-11-01

    RT-nested PCR has been introduced as a highly specific and sensitive assay method to detect the prostate-specific membrane antigen (PSM) mRNA in peripheral blood. However, appreciable percentages of false-positive cases have been reported. Additionally, primer sets reported previously could not discriminate between PSM and PSM', an alternatively spliced variant, mRNA. These isoforms can be produced from a single gene. Switches in alternative splicing patterns are often controlled with strict cell-type or developmental-stage specificity. Therefore, it is most important to discriminate between PSM mRNA and PSM' mRNA. Using our highly specific primer sets, PSM mRNA was detected in 3 of 24 peripheral blood samples of normal male volunteers (12.5%) and was not detected in peripheral blood of 11 normal female volunteers. PSM' mRNA was detected in 5 of 24 peripheral blood samples of normal male volunteers (20.8%) and in 4 of 11 of normal female volunteers (36.4%). PSM' mRNA induced false-positive results, it is important for genetic diagnosis of prostate cancer to discriminate between PSM and PSM' using our primer sets with high specificity. The advances in the uniquely designed primer sets may allow researchers to detect a real PSM mRNA without PSM' mRNA.

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

    Directory of Open Access Journals (Sweden)

    Cyril R Pernet

    2013-01-01

    Full Text Available 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.

  15. 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.

  16. 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

  17. 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.)

  18. 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/.

  19. Implications of false negative and false positive diagnosis in lymph node staging of NSCLC by means of ¹⁸F-FDG PET/CT.

    Directory of Open Access Journals (Sweden)

    Shaolei Li

    Full Text Available BACKGROUND: Integrated ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT is widely performed in hilar and mediastinal lymph node (HMLN staging of non-small cell lung cancer (NSCLC. However, the diagnostic efficiency of PET/CT remains controversial. This retrospective study is to evaluate the accuracy of PET/CT and the characteristics of false negatives and false positives to improve specificity and sensitivity. METHODS: 219 NSCLC patients with systematic lymph node dissection or sampling underwent preoperative PET/CT scan. Nodal uptake with a maximum standardized uptake value (SUV(max >2.5 was interpreted as PET/CT positive. The results of PET/CT were compared with the histopathological findings. The receiver operating characteristic (ROC curve was generated to determine the diagnostic efficiency of PET/CT. Univariate and multivariate analysis were conducted to detect risk factors of false negatives and false positives. RESULTS: The sensitivity, specificity, positive predictive value (PPV, negative predictive value (NPV, and accuracy of PET/CT in detecting HMLN metastases were 74.2% (49/66, 73.2% (112/153, 54.4% (49/90, 86.8% (112/129, and 73.5% (161/219. The ROC curve had an area under curve (AUC of 0.791 (95% CI 0.723-0.860. The incidence of false negative HMLN metastases was 13.2% (17 of 129 patients. Factors that are significantly associated with false negatives are: concurrent lung disease or diabetes (p4.0 (p=0.009. Postoperatively, 45.5% (41/90 patients were confirmed as false positive cases. The univariate analysis indicated age > 65 years old (p=0.009, well differentiation (p=0.002, and SUV(max of primary tumor ≦4.0 (p=0.007 as risk factors for false positive uptake. CONCLUSION: The SUV(max of HMLN is a predictor of malignancy. Lymph node staging using PET/CT is far from equal to pathological staging account of some risk factors. This study may provide some aids to pre-therapy evaluation and

  20. The difficulty of avoiding false positives in genome scans for natural selection.

    Science.gov (United States)

    Mallick, Swapan; Gnerre, Sante; Muller, Paul; Reich, David

    2009-05-01

    Several studies have found evidence for more positive selection on the chimpanzee lineage compared with the human lineage since the two species split. A potential concern, however, is that these findings may simply reflect artifacts of the data: inaccuracies in the underlying chimpanzee genome sequence, which is of lower quality than human. To test this hypothesis, we generated de novo genome assemblies of chimpanzee and macaque and aligned them with human. We also implemented a novel bioinformatic procedure for producing alignments of closely related species that uses synteny information to remove misassembled and misaligned regions, and sequence quality scores to remove nucleotides that are less reliable. We applied this procedure to re-examine 59 genes recently identified as candidates for positive selection in chimpanzees. The great majority of these signals disappear after application of our new bioinformatic procedure. We also carried out laboratory-based resequencing of 10 of the regions in multiple chimpanzees and humans, and found that our alignments were correct wherever there was a conflict with the published results. These findings throw into question previous findings that there has been more positive selection in chimpanzees than in humans since the two species diverged. Our study also highlights the challenges of searching the extreme tails of distributions for signals of natural selection. Inaccuracies in the genome sequence at even a tiny fraction of genes can produce false-positive signals, which make it difficult to identify loci that have genuinely been targets of selection.

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

    Directory of Open Access Journals (Sweden)

    Philip C Hill

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.

  2. Acridine orange staining as a replacement for subculturing of false-positive blood cultures with the BACTEC NR 660.

    OpenAIRE

    Hunter, J.S.

    1993-01-01

    Despite the customization of growth index thresholds within individual laboratories, use of the BACTEC NR 660 automated blood culture system results in a number of false-positive cultures. The results of Gram staining, acridine orange staining, and subculturing to agar media were evaluated on 210 false-positive blood cultures over a 6-month period. Inclusion of acridine orange staining in the routine workup of false-positive blood cultures can eliminate the need for subculturing.

  3. False Positive STEMI Activations in a Regional Network: Comprehensive Analysis and Clinical Impact. Results From the Catalonian Codi Infart Network.

    Science.gov (United States)

    Regueiro, Ander; Fernández-Rodríguez, Diego; Freixa, Xavier; Bosch, Xavier; Martín-Yuste, Victoria; Brugaletta, Salvatore; Roqué, Mercè; Sabaté, Manel; Masotti, Mónica

    2017-07-12

    ST-segment elevation myocardial infarction (STEMI) network activation by a noncardiologist reduces delay times but may increase the rate of false-positive STEMI diagnoses. We aimed to determine the prevalence, predictors, and clinical impact of false-positive activations within the Catalonian STEMI network (Codi Infart). From January 2010 through December 2011, all consecutive patients treated within the Codi Infart network were included. Code activations were classified as appropriate if they satisfied both electrocardiogram and clinical STEMI criteria. Appropriate activations were classified as false positives using 2 nonexclusive definitions: a) "angiographic" if a culprit coronary artery was not identified, and b) "clinical" if the discharge diagnosis was other than STEMI. In total, 5701 activations were included. Appropriate activation was performed in 87.8% of the episodes. The rate of angiographic false positives was 14.6%, while the rate of clinical false positives was 11.6%. Irrespective of the definition, female sex, left bundle branch block, and previous myocardial infarction were independent predictors of false-positive STEMI diagnoses. Using the clinical definition, hospitals without percutaneous coronary intervention and patients with complications during the first medical contact also had a false-positive STEMI diagnoses rate higher than the mean. In-hospital and 30-day mortality rates were similar for false-positive and true-positive STEMI patients after adjustment for possible confounders. False-positive STEMI diagnoses were frequent. Outcomes were similar for patients with a true-positive or false-positive STEMI diagnosis treated within a STEMI network. The presence of any modifiable predictors of a false-positive STEMI diagnosis warrants careful assessment to optimize the use of STEMI networks. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  4. False-positive pH aspirates after nasogastric tube insertion in head and neck tumour.

    Science.gov (United States)

    Sellers, Claudia Kate

    2012-08-27

    Nasogastric (NG) feeding tubes are commonly inserted to supplement enteral nutrition in certain patient groups, including those with head and neck cancers where swallowing may be compromised. An NHS National Patient Safety Alert was released in 2011 detailing ongoing cases of significant morbidity and mortality attached to the incorrect placement of NG feeding tubes in hospital inpatients. Since 2005, there were 21 deaths and 79 cases of harm nationally due to feeding into the lung through misplaced tubes. pH testing remains the first-line method of placement confirmation, with chest x-ray used when no aspirate is gained or where pH testing fails to confirm suitable acidity. We present a case report describing false-positive NG tube placement confirmation tests in a patient with head and neck cancer, who was administered feed into lung parenchyma with significant morbidity. We discuss the case for specific NG tube placement protocols in head and neck cancer patients.

  5. Quantification of false positive reduction in nucleic acid purification on hemorrhagic fever DNA.

    Energy Technology Data Exchange (ETDEWEB)

    James, Conrad D.; Pohl, Kenneth Roy; Derzon, Mark Steven; McClain, Jaime; Achyuthan, Komandoor

    2006-11-01

    Columbia University has developed a sensitive highly multiplexed system for genetic identification of nucleic acid targets. The primary obstacle to implementing this technology is the high rate of false positives due to high levels of unbound reporters that remain within the system after hybridization. The ability to distinguish between free reporters and reporters bound to targets limits the use of this technology. We previously demonstrated a new electrokinetic method for binary separation of kb pair long DNA molecules and oligonucleotides. The purpose of this project 99864 is to take these previous demonstrations and further develop the technique and hardware for field use. Specifically, our objective was to implement separation in a heterogeneous sample (containing target DNA and background oligo), to perform the separation in a flow-based device, and to develop all of the components necessary for field testing a breadboard prototype system.

  6. Pulmonary sequestration: a (131)I whole body scintigraphy false-positive result.

    Science.gov (United States)

    Spinapolice, Elena Giulia; Chytiris, S; Fuccio, C; Leporati, P; Volpato, G; Villani, L; Trifirò, G; Chiovato, L

    2014-08-01

    A 35-year-old woman affected by a well-differentiated papillary thyroid carcinoma was referred to our hospital to perform a (131)Iodine ((131)I) whole body scintigraphy for restaging purpose. The patient had been previously treated with total thyroidectomy and three subsequent doses of (131)I for the ablation of a remnant jugular tissue and a suspected metastatic focus at the superior left hemi-thorax. In spite of the previous treatments with (131)I, planar and tomographic images showed the persistence of an area of increased uptake at the superior left hemi-thorax. This finding prompted the surgical resection of the lesion. Histological examination of the surgical specimen showed the presence of a pulmonary tissue consistent with pulmonary sequestration. Even though rare, pulmonary sequestration should be included in the potential causes of false-positive results of radioiodine scans.

  7. Influence of population prevalences on numbers of false positives: an overlooked entity.

    Science.gov (United States)

    Cronin, Paul; Kelly, Aine Marie

    2011-09-01

    Disease prevalence alters the number of true positives (TP), true negatives (TN), false negatives (FN), and false positives (FP), even if the sensitivity and specificity of a test stays the same. We illustrate this using data for the detection of suspected acute pulmonary embolism (PE) from the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II). We chose PE because of the clinical significance of the disease, the low prevalence of PE in the patient population being tested with CTPA with the widespread adoption of CTPA, and the serious clinical consequences of anticoagulation therapy in FP patients. Based on PIOPED II data (sensitivity 83%, specificity 96%), at a disease prevalence of approximately 5%, the number of FP patients is greater than the number of TP patients. Scaled to the US population, at a disease prevalence of 5%, there would be 139,800 FPs and 3,356,200 TNs. Assuming a mortality rate of 0.5% and a 3.0% rate of major bleeding secondary to anticoagulation therapy for well-controlled patients, if all FP patients received anticoagulation, there would be 699 deaths and 4194 major bleeding complications. At a prevalence of approximately 5% for PE, the number of FPs approaches or is greater than the number of TPs for CTPA for the detection of suspected acute PE. Patients with FP results may receive unnecessary, potentially harmful treatment with anticoagulation therapy. Population prevalence of disease needs to be taken into account along with the diagnostic accuracy of a test, because this may significantly affect downstream patient outcomes. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

  8. Automated detection of pulmonary nodules in CT: false positive reduction by combining multiple classifiers

    Science.gov (United States)

    Suárez-Cuenca, Jorge Juan; Guo, Wei; Li, Qiang

    2011-03-01

    The purpose of this study was to investigate the usefulness of various classifier combination methods for improving the performance of a CAD system for pulmonary nodule detection in CT. We employed CT cases in the publicly available lung image database consortium (LIDC) dataset, which included 85 CT cases with 110 nodules. We first used six individual classifiers for nodule detection in CT, including linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), artificial neural network (ANN), and three types of support vector machines (SVM). Five informationfusion methods were then employed to combine the classifiers' outputs for improving detection performance. The five combination methods included two supervised (likelihood ratio method and neural network) and three unsupervised ones (the mean, the product, and the majority-vote of the output scores from the six individual classifiers). Leave-one-caseout was employed to train and test individual classifiers and supervised combination methods. At a sensitivity of 80 %, the numbers of false positives per case for the six individual classifiers were 6.1 for LDA, 19.9 for QDA, 8.6 for ANN, 23.7 for SVM-dot, 17.0 for SVM-poly, and 23.35 for SVM-ANOVA; the numbers of false positives per case for the five combination methods were 3.4 for the majority-vote rule, 6.2 for the mean, 5.7 for the product, 9.7 for the neural network, and 28.1 for the likelihood ratio method. The majority-vote rule achieved higher performance levels than other combination methods. It also achieved higher performance than the best individual classifier, which is not the case for other combination methods.

  9. Eliminating false positive C4 sugar tests on New Zealand Manuka honey.

    Science.gov (United States)

    Rogers, Karyne M; Somerton, Kerry; Rogers, Pamela; Cox, Julie

    2010-08-30

    Carbon isotope analyses (delta(13)C) of some New Zealand Manuka honeys show that they often fail the internationally recognised Association of Official Analytical Chemists sugar test (AOAC method 998.12) which detects added C(4) sugar, although these honeys are from unadulterated sources. Failure of these high value products is detrimental to the New Zealand honey industry, not only in lost export revenue, but also in brand and market reputation damage. The standard AOAC test compares the carbon isotope value of the whole honey and corresponding protein isolated from the same honey. Differences between whole honey and protein delta(13)C values should not be greater than +1.0 per thousand, as it indicates the possibility of adulteration with syrups or sugars from C(4) plants such as high fructose corn syrup or cane sugar.We have determined that during the standard AOAC method, pollen and other insoluble components are isolated with the flocculated protein. These non-protein components have isotope values which are considerably different from those of the pure protein, and can shift the apparent delta(13)C value of protein further away from the delta(13)C value of the whole honey, giving a false positive result for added C(4) sugar. To eliminate a false positive C(4) sugar test for Manuka honey, prior removal of pollen and other insoluble material from the honey is necessary to ensure that only the pure protein is isolated. This will enable a true comparison between whole honey and protein delta(13)C isotopes. Furthermore, we strongly suggest this modification to the AOAC method be universally adopted for all honey C(4) sugar tests. 2010 John Wiley & Sons, Ltd.

  10. A new method with flexible and balanced control of false negatives and false positives for hit selection in RNA interference high-throughput screening assays.

    Science.gov (United States)

    Zhang, Xiaohua Douglas

    2007-08-01

    The z-score method and its variants for testing mean difference are commonly used for hit selection in high-throughput screening (HTS) assays. Strictly standardized mean difference (SSMD) offers a way to measure and classify the short interfering RNA (siRNA) effects. In this article, based on SSMD, the authors propose a new testing method for hit selection in RNA interference (RNAi) HTS assays. This SSMD-based method allows the differentiation between siRNAs with large and small effects on the assay output and maintains flexible and balanced control of both the false-negative rate, in which the siRNAs with strong effects are not selected as hits, and the restricted false-positive rate, in which the siRNAs with weak or no effects are selected as hits. This method directly addresses the size of siRNA effects represented by the strength of difference between an siRNA and a negative reference, whereas the classic z-score method and t-test of testing no mean difference address whether the mean of an siRNA is exactly the same as the mean of a negative reference. This method can readily control the false-negative rate, whereas it is nontrivial for the classic z-score method and t-test to control the false-negative rate. Therefore, theoretically, the SSMD-based method offers better control of the sizes of siRNA effects and the associated false-positive and false-negative rates than the commonly used z-score method and t-test for hit selection in HTS assays. The SSMD-based method should generally be applicable to any assay in which the end point is a difference in signal compared to a reference sample, including those for RNAi, receptor, enzyme, and cellular function.

  11. False-positive buprenorphine by CEDIA in patients prescribed amisulpride or sulpiride.

    Science.gov (United States)

    Birch, M A; Couchman, L; Pietromartire, S; Karna, T; Paton, C; McAllister, R; Marsh, A; Flanagan, R J

    2013-05-01

    Buprenorphine is a potent partial opioid agonist that is analyzed in urine to (i) monitor adherence to maintenance or detoxification therapy and (ii) detect illicit use. Buprenorphine analysis is commonly conducted on urine by immunoassay, but is subject to cross-reactivity from other drugs/drug metabolites, including morphine, codeine and dihydrocodeine. This study reports false-positive buprenorphine analysis [Thermo Fisher Scientific cloned enzyme donor immunoassay (CEDIA)] in patients who denied unauthorized buprenorphine use prior to sampling, but who had been prescribed amisulpride. In two cases, confirmatory analysis by liquid chromatography-tandem mass spectrometry was negative (sulpiride in the CEDIA buprenorphine assay is low (estimated at 0.003 and 0.002%, respectively), it remains a significant consideration given the likely high concentrations of these compounds in urine relative to the low cutoff of the buprenorphine assay. Neither amisulpride nor sulpiride was listed as potential sources of interference on the CEDIA data sheet when this work was performed. These findings highlight the importance of confirming immunoassay-positive buprenorphine results using a more selective analytical technique.

  12. False-positive methadone urine drug screen in a patient treated with quetiapine.

    Science.gov (United States)

    Lasić, Davor; Uglesić, Boran; Zuljan-Cvitanović, Marija; Supe-Domić, Daniela; Uglesić, Lovro

    2012-06-01

    We present a case of T.M. admitted to University Department of Psychiatry, Split University Hospital Center, in Croatia, because of the acute psychotic reaction (F23.9). The patient's urine tested positive for methadone without a history of methadone ingestion. Urine drug screen was performed with the COBAS Integra Methadone II test kit (kinetic interaction of microparticles in solution /KIMS/ methodology) by Roche. Drugs that have been shown to cross-react with methadone feature a tricyclic structure with a sulfur and nitrogen atom in the middle ring, which is common for both quetiapine and methadone. Therefore, it is plausible that this structural similarity between quetiapine and methadone could underlie the cross-reactivity on methadone drug screen. Besides quetiapine, a number of routinely prescribed medications have been associated with triggering false-positive urine drug screen results. Verification of the test results with a different screening test or additional analytical tests should be performed to avoid adverse consequences for the patients.

  13. Serum immunoglobulin M concentration is positively related to metabolic syndrome in an adult population: Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH Cohort Study.

    Directory of Open Access Journals (Sweden)

    Kun Song

    Full Text Available Persistent low-grade systemic inflammation has been increasingly recognized as a common pathological process, and an important contributing factor to cardiovascular diseases and its risk factor, metabolic syndrome. Immunoglobulin M is reactive to multiple autoantigens and is inferred to be important for autoimmunity, implying that immunoglobulin M may be a potential risk factor for metabolic syndrome. However, few epidemiological studies are available which are related to this potential link. Therefore, we designed a cross-sectional study of 9,379 subjects to evaluate the relationship between immunoglobulin M and metabolic syndrome in an adult population. Subjects who received health examinations were recruited from the Tianjin Medical University General Hospital-Health Management Center in Tianjin, China. Immunoglobulin M was determined with an immunonephelometric technique. Metabolic syndrome was defined according to the criteria of the American Heart Association scientific statements of 2009. Multiple logistic regression analysis was used to examine the relationships between the quartiles of immunoglobulin M and the prevalence of metabolic syndrome. After adjustment for covariates, the odds ratio of having metabolic syndrome in the fourth quartile compared with the first quartile of immunoglobulin M was 1.19 times for males (95% confidence interval, 1.002-1.41 and 1.39 times for females (95% confidence interval, 1.07-1.80. Immunoglobulin M levels also showed positive relationships with the ratio of elevated triglycerides and reduced high-density lipoprotein cholesterol in males. The study is the first to show that immunoglobulin M is independently related to metabolic syndrome and its individual components (elevated triglycerides and reduced high-density lipoprotein cholesterol in males, whereas immunoglobulin M is independently related to metabolic syndrome in females but not to its individual components. Further studies are needed to

  14. Serum Immunoglobulin M Concentration Is Positively Related to Metabolic Syndrome in an Adult Population: Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) Cohort Study

    Science.gov (United States)

    Zhang, Qing; Wang, Chongjin; Guo, Yinting; Wu, Hongmei; Liu, Li; Jia, Qiyu; Wang, Xing; Shi, Hongbin; Sun, Shaomei; Niu, Kaijun

    2014-01-01

    Persistent low-grade systemic inflammation has been increasingly recognized as a common pathological process, and an important contributing factor to cardiovascular diseases and its risk factor, metabolic syndrome. Immunoglobulin M is reactive to multiple autoantigens and is inferred to be important for autoimmunity, implying that immunoglobulin M may be a potential risk factor for metabolic syndrome. However, few epidemiological studies are available which are related to this potential link. Therefore, we designed a cross-sectional study of 9,379 subjects to evaluate the relationship between immunoglobulin M and metabolic syndrome in an adult population. Subjects who received health examinations were recruited from the Tianjin Medical University General Hospital-Health Management Center in Tianjin, China. Immunoglobulin M was determined with an immunonephelometric technique. Metabolic syndrome was defined according to the criteria of the American Heart Association scientific statements of 2009. Multiple logistic regression analysis was used to examine the relationships between the quartiles of immunoglobulin M and the prevalence of metabolic syndrome. After adjustment for covariates, the odds ratio of having metabolic syndrome in the fourth quartile compared with the first quartile of immunoglobulin M was 1.19 times for males (95% confidence interval, 1.002–1.41) and 1.39 times for females (95% confidence interval, 1.07–1.80). Immunoglobulin M levels also showed positive relationships with the ratio of elevated triglycerides and reduced high-density lipoprotein cholesterol in males. The study is the first to show that immunoglobulin M is independently related to metabolic syndrome and its individual components (elevated triglycerides and reduced high-density lipoprotein cholesterol) in males, whereas immunoglobulin M is independently related to metabolic syndrome in females but not to its individual components. Further studies are needed to explore the

  15. Searching for Long-Period Companions and False Positives within the APOGEE Catalog of Companion Candidates

    Science.gov (United States)

    Nguyen, Duy; Troup, Nicholas William; Majewski, Steven R.

    2017-01-01

    The Sloan Digital Sky Survey (SDSS) Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a large-scale, high-resolution, H-band, spectroscopic survey that has acquired high S/N spectra of 146,000 stars distributed across the Galactic bulge, disk, and halo with a radial velocity (RV) precision of ~100 m/s. We follow up stellar companion detections from the APOGEE DR12 catalog of 382 total APOGEE-identified companions, of which 376 are previously unknown companion candidates. The APOGEE team strives not only to continue expanding the census of extrasolar companions, but also to confirm and characterize our RV detections through a variety of means.We present findings from our investigation of the Kozai mechanism, which explains the development of close-orbiting binaries through an ejected third companion. To do so, we are undertaking a targeted search for long-period companions with hopes to provide further evidence for the Kozai mechanism. This hunt for longer period companions begins with a search for long-term RV trends within the APOGEE data. We have also obtained diffraction-limited imaging using speckle interferometry at WIYN and Gemini North Observatories, as well as AO LMIRcam images from the LBT, to make direct searches for long-period stellar companions.It is critical to purge our companion candidate detections of false positives, and we discuss several methods we are pursuing to do this. For example, highly active stars have been observed to mimic RV measurements. We have obtained optical high-resolution spectral follow-ups from the ARC 3.5m, the HET, and MMT to analyze potential stellar activity indicators such as Calcium H and K. Emission detected in these well-known stellar activity indicators suggests a false radial velocity measurement.

  16. 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 disappea

  17. 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 disappea

  18. False-positive rapid plasma reagin testing in patients with acute Plasmodium vivax malaria: a case control study.

    Science.gov (United States)

    Maves, Ryan C; Dean, Katherine; Gadea, Nilda; Halsey, Eric S; Graf, Paul C F; Lescano, Andres G

    2014-01-01

    Non-treponemal tests such as the rapid plasma reagin (RPR) assay are mainstays of syphilis diagnosis, but false-positive tests are common. We identified false-positive RPR titers in 8.2% of patients with malaria due to Plasmodium vivax in northern Peru. Similar rates were not detected in patients with other acute febrile illnesses.

  19. Astrophysical false positives in direct imaging for exoplanets: a white dwarf close to a rejuvenated star

    Science.gov (United States)

    Zurlo, A.; Vigan, A.; Hagelberg, J.; Desidera, S.; Chauvin, G.; Almenara, J. M.; Biazzo, K.; Bonnefoy, M.; Carson, J. C.; Covino, E.; Delorme, P.; D'Orazi, V.; Gratton, R.; Mesa, D.; Messina, S.; Moutou, C.; Segransan, D.; Turatto, M.; Udry, S.; Wildi, F.

    2013-06-01

    Context. As is the case for all techniques involved in the research for exoplanets, direct imaging has to take into account the probability of so-called astrophysical false positives, which are phenomena that mimic the signature of the objects we are seeking. Aims: In this work we present the case of a false positive found during a direct-imaging survey conducted with VLT/NACO. A promising exoplanet candidate was detected around the K2-type star HD 8049 in July 2010. Its contrast of ΔH = 7.05 at 1.57 arcsec allowed us to assume a 35 MJup companion at 50 projected AU, for the nominal system age and heliocentric distance. Methods: To check whether it was gravitationally bound to the host star, as opposed to an unrelated background object, we re-observed the system one year later and concluded a high probability of a bound system. We also used radial velocity measurements of the host star, spanning a time range of ~30 yr, to constrain the companion's mass and orbital properties, as well as to probe the host star's spectral age indicators and general spectral energy distribution. We also obtained U-band imaging with EFOSC and near-infrared spectroscopy for the companion. Results: Combining all these information we conclude that the companion of HD 8049 is a white dwarf (WD) with temperature Teff = 18 800 ± 2100 K and mass MWD = 0.56 ± 0.08 M⊙. The significant radial velocity trend combined with the imaging data indicates that the most probable orbit has a semi-major axis of about 50 AU. The discrepancy between the age indicators speaks against a bona-fide young star. The moderately high level of chromospheric activity and fast rotation, mimicking the properties of a young star, might be induced by the exchange of mass with the progenitor of the WD. This example demonstrates some of the challenges in determining accurate age estimates and identifications of faint companions. Based on observations collected at La Silla and Paranal Observatory, ESO (Chile): Programs

  20. A False Positive For Ocean Glint on Exoplanets: the Latitude-Albedo Effect

    CERN Document Server

    Cowan, Nicolas B; 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 lightcurves. 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 th...

  1. The Transiting Exoplanet Survey Satellite: Simulations of planet detections and astrophysical false positives

    CERN Document Server

    Sullivan, Peter W; Berta-Thompson, Zachory K; Charbonneau, David; Deming, Drake; Dressing, Courtney D; Latham, David W; Levine, Alan M; McCullough, Peter R; Morton, Timothy; Ricker, George R; Vanderspek, Roland; Woods, Deborah

    2015-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a NASA-sponsored Explorer mission that will perform a wide-field survey for planets that transit bright host stars. Here, we predict the properties of the transiting planets that TESS will detect along with the eclipsing binary stars that produce false-positive photometric signals. The predictions are based on Monte Carlo simulations of the nearby population of stars, occurrence rates of planets derived from Kepler, and models for the photometric performance and sky coverage of the TESS cameras. We expect that TESS will find approximately 1700 transiting planets from 200,000 pre-selected target stars. This includes 556 planets smaller than twice the size of Earth, of which 419 are hosted by M dwarf stars and 137 are hosted by FGK dwarfs. Approximately 130 of the R < 2 R_Earth planets will have host stars brighter than K = 9. Approximately 48 of the planets with R < 2 R_Earth lie within or near the habitable zone (0.2 < S/S_Earth < 2), and between...

  2. 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.

  3. 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.

  4. Factors influencing accuracy of referral and the likelihood of false positive referral by optometrists in Bradford, United Kingdom.

    Science.gov (United States)

    Davey, Christopher James; Scally, Andrew J; Green, Clare; Mitchell, Edwin S; Elliott, David B

    2016-01-01

    Levels of false positive referral to ophthalmology departments can be high. This study aimed to evaluate commonality between false positive referrals in order to find the factors which may influence referral accuracy. In 2007/08, a sample of 431 new Ophthalmology referrals from the catchment area of Bradford Royal Infirmary were retrospectively analysed. The proportion of false positive referrals generated by optometrists decreases with experience at a rate of 6.2% per year since registration (p<0.0001). Community services which involved further investigation done by the optometrist before directly referring to the hospital were 2.7 times less likely to refer false positively than other referral formats (p=0.007). Male optometrists were about half as likely to generate a false positive referral than females (OR=0.51, p=0.008) and as multiple/corporate practices in the Bradford area employ less experienced and more female staff, independent practices generate about half the number of false positive referrals (OR=0.52, p=0.005). Clinician experience has the greatest effect on referral accuracy although there is also a significant effect of gender with women tending to refer more false positives. This may be due to a different approach to patient care and possibly a greater sensitivity to litigation. The improved accuracy of community services (which often refer directly after further investigation) supports further growth of these schemes. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  5. Diagnostic performance of serological tests for swine brucellosis in the presence of false positive serological reactions.

    Science.gov (United States)

    Dieste-Pérez, L; Blasco, J M; de Miguel, M J; Moriyón, I; Muñoz, P M

    2015-04-01

    Swine brucellosis caused by Brucella suis biovar 2 is an emerging disease in Europe. Currently used diagnostic tests for swine brucellosis detect antibodies to the O-polysaccharide (O-PS) of Brucella smooth lipopolysaccharide (S-LPS) but their specificity is compromised by false-positive serological reactions (FPSRs) when bacteria carrying cross-reacting O-PS infect pigs. FPSRs occur throughout Europe, and the only tool available for a specific B. suis diagnosis is the intradermal test with Brucella protein extracts free of O-PS or S-LPS. Using sera of 162 sows naturally infected by B. suis biovar 2, 406 brucellosis-free sows, and 218 pigs of brucellosis-free farms affected by FPSR, we assessed the diagnostic performance of an indirect ELISA with rough LPS (thus devoid of O-PS) and of gel immunodiffusion, counterimmunoelectrophoresis, latex agglutination and indirect ELISA with O-PS free proteins in comparison with several S-LPS tests (Rose Bengal, complement fixation, gel immunodiffusion and indirect ELISA). When adjusted to 100% specificity, the sensitivity of the rough LPS ELISA was very low (30%), and adoption of other cut-offs resulted in poor specificity/sensitivity ratios. Although their specificity was 100%, the sensitivity of protein tests (ELISA, latex agglutination, counterimmunoelectrophoresis, and gel immunodiffusion) was only moderate (45, 58, 61 and 63%, respectively). Among S-LPS tests, gel immunodiffusion was the only test showing acceptable sensitivity/specificity (68 and 100%, respectively). Despite these shortcomings, and when the purpose is to screen out FPSR at herd level, gel immunodiffusion tests may offer a technically simple and practical alternative to intradermal testing.

  6. Modelling the cumulative risk of a false-positive screening test.

    Science.gov (United States)

    Hubbard, Rebecca A; Miglioretti, Diana L; Smith, Robert A

    2010-10-01

    The goal of a screening test is to reduce morbidity and mortality through the early detection of disease; but the benefits of screening must be weighed against potential harms, such as false-positive (FP) results, which may lead to increased healthcare costs, patient anxiety, and other adverse outcomes associated with diagnostic follow-up procedures. Accurate estimation of the cumulative risk of an FP test after multiple screening rounds is important for program evaluation and goal setting, as well as informing individuals undergoing screening what they should expect from testing over time. Estimation of the cumulative FP risk is complicated by the existence of censoring and possible dependence of the censoring time on the event history. Current statistical methods for estimating the cumulative FP risk from censored data follow two distinct approaches, either conditioning on the number of screening tests observed or marginalizing over this random variable. We review these current methods, identify their limitations and possibly unrealistic assumptions, and propose simple extensions to address some of these limitations. We discuss areas where additional extensions may be useful. We illustrate methods for estimating the cumulative FP recall risk of screening mammography and investigate the appropriateness of modelling assumptions using 13 years of data collected by the Breast Cancer Surveillance Consortium (BCSC). In the BCSC data we found evidence of violations of modelling assumptions of both classes of statistical methods. The estimated risk of an FP recall after 10 screening mammograms varied between 58% and 77% depending on the approach used, with an estimate of 63% based on what we feel are the most reasonable modelling assumptions.

  7. Is the false-positive rate in mammography in North America too high?

    Science.gov (United States)

    Le, Michelle T; Mothersill, Carmel E; Seymour, Colin B; McNeill, Fiona E

    2016-09-01

    The practice of investigating pathological abnormalities in the breasts of females who are asymptomatic is primarily employed using X-ray mammography. The importance of breast screening is reflected in the mortality-based benefits observed among females who are found to possess invasive breast carcinoma prior to the manifestation of clinical symptoms. It is estimated that population-based screening constitutes a 17% reduction in the breast cancer mortality rate among females affected by invasive breast carcinoma. In spite of the significant utility that screening confers in those affected by invasive cancer, limitations associated with screening manifest as potential harms affecting individuals who are free of invasive disease. Disease-free and benign tumour-bearing individuals who are subjected to diagnostic work-up following a screening examination constitute a population of cases referred to as false positives (FPs). This article discusses factors contributing to the FP rate in mammography and extends the discussion to an assessment of the consequences associated with FP reporting. We conclude that the mammography FP rate in North America is in excess based upon the observation of overtreatment of in situ lesions and the disproportionate distribution of detriment and benefit among the population of individuals recalled for diagnostic work-up subsequent to screening. To address the excessive incidence of FPs in mammography, we investigate solutions that may be employed to remediate the current status of the FP rate. Subsequently, it can be suggested that improvements in the breast-screening protocol, medical litigation risk, image interpretation software and the implementation of image acquisition modalities that overcome superimposition effects are promising solutions.

  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. Preventing intense false positive and negative reactions attributed to the principle of ELISA to re-investigate antibody studies in autoimmune diseases.

    Science.gov (United States)

    Terato, Kuniaki; Do, Christopher T; Cutler, Dawn; Waritani, Takaki; Shionoya, Hiroshi

    2014-05-01

    To study the possible involvement of potential environmental pathogens in the pathogenesis of autoimmune diseases, it is essential to investigate antibody responses to a variety of environmental agents and autologous components. However, none of the conventional ELISA buffers can prevent the false positive and negative reactions attributed to its principal, which utilizes the high binding affinity of proteins to plastic surfaces. The aims of this study are to reveal all types of non-specific reactions associated with conventional buffer systems, and to re-investigate antibody responses to potential environmental pathogenic and autologous antigens in patients with autoimmune diseases using a newly developed buffer system "ChonBlock™" by ELISA. Compared to conventional buffers, the new buffer was highly effective in reducing the most intense false positive reaction caused by hydrophobic binding of immunoglobulin in sample specimens to plastic surfaces, "background (BG) noise reaction", and other non-specific reactions without interfering with antigen-antibody reactions. Applying this buffer, we found that IgG antibody responses to Escherichia coli O111:B4, E. coli lipopolysaccharide (LPS) and peptidoglycan polysaccharide (PG-PS) were significantly lower or tended to be lower in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), whereas IgA antibody responses to these antigens were equal or tended to be higher compared to normal controls. As a consequence, the IgA/IgG antibody ratios against these agents were significantly higher in patients with RA and SLE, except for Crohn's disease, which showed significantly higher IgG responses to these antigens. To assay antibodies in human sera, it is indispensable to eliminate false positive and negative reactions by using an appropriate buffer system, and to include antigen non-coated blank wells to determine BG noise reactions of invidual samples. Finally, based on our preliminary analysis in

  10. Risk Factors Associated with False Positive HIV Test Results in a Low-Risk Urban Obstetric Population

    Directory of Open Access Journals (Sweden)

    Tamara T. Chao

    2012-01-01

    Full Text Available Objective. To examine risk factors for false positive HIV enzyme immunoassay (EIA testing at delivery. Study Design. A review of pregnant women who delivered at Parkland Hospital between 2005 and 2008 was performed. Patients routinely received serum HIV EIA testing at delivery, with positive results confirmed through immunofluorescent testing. Demographics, HIV, hepatitis B surface antigen (HBsAg, and rapid plasma reagin (RPR results were obtained. Statistical analyses included Pearson's chi-square and Student's t-test. Results. Of 47,794 patients, 47,391 (99% tested negative, 145 (0.3% falsely positive, 172 (0.4% positive, and 86 (0.2% equivocal or missing HIV results. The positive predictive value of EIA was 54.3%. Patients with false positive results were more likely nulliparous (43% versus 31%, <0.001 and younger (23.9±5.7 versus 26.2±5.9 years, <0.001. HIV positive patients were older than false positive patients and more likely positive for HBsAg and RPR. Conclusion. False positive HIV testing at delivery using EIA is associated with young maternal age and nulliparity in this population.

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

    Science.gov (United States)

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

    2013-12-01

    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.

  12. 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.

  13. False-positive fluorodeoxyglucose positron emission tomography results after chemotherapy in patients with metastatic seminoma.

    Science.gov (United States)

    Decoene, Jasper; Winter, Christian; Albers, Peter

    2015-01-01

    The treatment of residual masses after chemotherapy in seminomas remains a controversial topic. Postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) in all patients would lead to severe overtreatment with a high rate of complications and additional procedures. For this reason, fluorodeoxyglucose positron emission tomography (FDG-PET) was introduced. FDG-PET has an accuracy of 88%. In 15% of cases, FDG-PET findings are false positive (FP) with unclear consequences. Therefore, we retrospectively investigated the rate of unnecessary procedures due to FP results on FDG-PET. Between July 2003 and September 2013 we performed 305 PC-RPLNDs in 277 patients, 22 because of metastatic seminoma. Of them, 11 patients had a preoperative FDG-PET at least 6 weeks after chemotherapy. Indication for surgery was a marker-negative progression of the lesion in 7 patients who did not undergo FDG-PET, a marker-negative progression with a negative result on FDG-PET in 2 patients, and a positive result on FDG-PET with normal markers in 9 patients. Furthermore, PC-RPLND was indicated in 3 patients because of ureteral compression/infiltration with ureteral stents or nephrostomies. In 1 patient, there was uncertainty whether the initial retroperitoneal tumor contained choriocarcinoma elements. Standardized uptake values (SUVs) were recorded for all patients undergoing FDG-PET. The FDG-PET findings were FP in 7 of 11 (64%) patients. The median age of the patients was 45.4 years (39-49). The median SUV in the patients was 6.6 (3.1-11.6), and the median diameter of the residual mass was 6.8 cm (2.9-11). In 4 of 7 patients, intraoperative or postoperative complications occurred (polar artery ligation with functional loss, bilateral non-nerve-sparing technique with retrograde ejaculation, ureteral replacement with an ileal segment, and pulmonary embolism). In patients with metastatic seminoma who received chemotherapy, FDG-PET is a valuable tool to evaluate whether the residual mass

  14. To Control False Positives in Gene-Gene Interaction Analysis: Two Novel Conditional Entropy-Based Approaches: e81984

    National Research Council Canada - National Science Library

    Xiaoyu Zuo; Shaoqi Rao; An Fan; Meihua Lin; Haoli Li; Xiaolei Zhao; Jiheng Qin

    2013-01-01

    ...) were developed for detecting non-linear dependence between genetic loci, but they are potentially at the risk of inflated false positive error, in particular when the main effects at one or both loci are salient...

  15. To control false positives in gene-gene interaction analysis: two novel conditional entropy-based approaches

    National Research Council Canada - National Science Library

    Zuo, Xiaoyu; Rao, Shaoqi; Fan, An; Lin, Meihua; Li, Haoli; Zhao, Xiaolei; Qin, Jiheng

    2013-01-01

    ...) were developed for detecting non-linear dependence between genetic loci, but they are potentially at the risk of inflated false positive error, in particular when the main effects at one or both loci are salient...

  16. 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.

  17. A semiparametric censoring bias model for estimating the cumulative risk of a false-positive screening test under dependent censoring.

    Science.gov (United States)

    Hubbard, Rebecca A; Miglioretti, Diana L

    2013-03-01

    False-positive test results are among the most common harms of screening tests and may lead to more invasive and expensive diagnostic testing procedures. Estimating the cumulative risk of a false-positive screening test result after repeat screening rounds is, therefore, important for evaluating potential screening regimens. Existing estimators of the cumulative false-positive risk are limited by strong assumptions about censoring mechanisms and parametric assumptions about variation in risk across screening rounds. To address these limitations, we propose a semiparametric censoring bias model for cumulative false-positive risk that allows for dependent censoring without specifying a fixed functional form for variation in risk across screening rounds. Simulation studies demonstrated that the censoring bias model performs similarly to existing models under independent censoring and can largely eliminate bias under dependent censoring. We used the existing and newly proposed models to estimate the cumulative false-positive risk and variation in risk as a function of baseline age and family history of breast cancer after 10 years of annual screening mammography using data from the Breast Cancer Surveillance Consortium. Ignoring potential dependent censoring in this context leads to underestimation of the cumulative risk of false-positive results. Models that provide accurate estimates under dependent censoring are critical for providing appropriate information for evaluating screening tests.

  18. Background parenchymal enhancement at breast MR imaging: normal patterns, diagnostic challenges, and potential for false-positive and false-negative interpretation.

    Science.gov (United States)

    Giess, Catherine S; Yeh, Eren D; Raza, Sughra; Birdwell, Robyn L

    2014-01-01

    At magnetic resonance (MR) imaging, both normal and abnormal breast tissue enhances after contrast material administration. The morphology and temporal degree of enhancement of pathologic breast tissue relative to normal breast tissue form the basis of MR imaging's diagnostic accuracy in the detection and diagnosis of breast disease. Normal parenchymal enhancement at breast MR imaging is termed background parenchymal enhancement (BPE). BPE may vary in degree and distribution in different patients as well as in the same patient over time. Typically BPE is minimal or mild in overall degree, with a bilateral, symmetric, diffuse distribution and slow early and persistent delayed kinetic features. However, BPE may sometimes be moderate or marked in degree, with an asymmetric or nondiffuse distribution and rapid early and plateau or washout delayed kinetic features. These patterns cause diagnostic difficulty because these features can be seen with malignancy. This article reviews typical and atypical patterns of BPE seen at breast MR imaging. The anatomic and physiologic influences on BPE in women undergoing diagnostic and screening breast MR imaging are reviewed. The potential for false-positive and false-negative interpretations due to BPE are discussed. Radiologists can improve their interpretive accuracy by increasing their understanding of various BPE patterns, influences on BPE, and the potential effects of BPE on MR imaging interpretation.

  19. Exploring Habitability Markers, Biosignatures, and Their False Positives Using Spectral Models of Terrestrial Exoplanets

    Science.gov (United States)

    Schwieterman, Edward W.

    )2 feature in a variety of simulated atmospheres with different N2 abundances with both synthetic direct-imaging and transit transmission spectra. Third, I investigate observational indicators of planetary mechanisms that may generate abiotic oxygen (O2 or O3) on exoplanets, leading to potential "false positives" for life. Abiotic production of O2 from CO2 photolysis potentially leads to detectable amounts of CO as a byproduct. Oxygen build up from massive H-loss during a runaway greenhouse could leave behind more O2 than could be plausibly produced by biology. In this case density dependent O4 features would be strong and potentially indicative of this process. I investigate the strength and detectability of CO (at 2.35 and 4.6 mum) and O4 (at 0.345, 0.36, 0.38, 0.445, 0.475, 0.53, 0.57, 0.63, 1.06, and 1.27 mum) absorption for these abiotic oxygen scenarios in both transmission and direct-imaging spectroscopy. Finally, I present an interdisciplinary study of nonphotosynthetic pigments as alternative surface reflectance biosignatures, in contrast to direct photosynthetic signatures like the vegetation red edge. This study includes reflectance measurements of a variety of pigmented organisms in the laboratory, illustrating a wide range of spectral diversity. I also model the spectra of hypothetical planets containing nonphotosynthetic pigment biosignatures including the confounding spectral effects of the atmosphere. I find that these signatures could potentially be observable in disk-averaged spectra depending on the fraction of the planet containing the signature. Organisms with nonphotosynthetic pigments will produce reflectance signatures different than that of the commonly referenced vegetation red edge, and push us to broaden our understanding of what surface biosignatures might look like on Earth-like exoplanets once remote characterization of these worlds becomes possible.

  20. Predicting a positive response to intravenous immunoglobulin in isolated lower motor neuron syndromes.

    Directory of Open Access Journals (Sweden)

    James R Burrell

    Full Text Available OBJECTIVE: To determine clinically related characteristics in patients with pure lower motor neuron (LMN syndromes, not fulfilling accepted diagnostic criteria, who were likely to respond to intravenous immunoglobulin (IVIg treatment. METHODS: Demographic, clinical, laboratory and neurophysiological characteristics were prospectively collected from patients with undifferentiated isolated LMN syndromes who were then treated with IVIg. Patients were classified as either responders or non-responders to therapy with IVIg based on clinical data and the two groups were compared. RESULTS: From a total cohort of 42 patients (30 males, 12 females, aged 18-83 years, 31 patients responded to IVIg and 11 did not. Compared to patients that developed progressive neurological decline, responders were typically younger (45.8 compared to 56.0 years, P<0.05 and had upper limb (83.9% compared to 63.6%, NS, unilateral (80.6% compared to 45.5%, P<0.05, and isolated distal (54.1% compared to 9.1%, P<0.05 weakness. Patients with predominantly upper limb, asymmetrical, and distal weakness were more likely to respond to IVIg therapy. Of the patients who responded to treatment, only 12.9% had detectable GM(1 antibodies and conduction block (not fulfilling diagnostic criteria was only identified in 22.6%. CONCLUSIONS: More than 70% of patients with pure LMN syndromes from the present series responded to treatment with IVIg therapy, despite a low prevalence of detectable GM(1 antibodies and conduction block. Patients with isolated LMN presentations, not fulfilling accepted diagnostic criteria, may respond to IVIg therapy, irrespective of the presence of conduction block or GM(1 antibodies, and should be given an empirical trial of IVIg to determine treatment responsiveness.

  1. [A pseudo-outbreak of pharyngeal gonorrhoea related to a false-positive PCR-result

    NARCIS (Netherlands)

    Verzijl, A.; Berretty, P.J.; Erceg, A.; Krekels, G.A.; Brule, A.J. van den; Boel, C.H.

    2007-01-01

    Nucleic acid amplification tests, including the polymerase chain reaction (PCR), are sensitive and specific tests that are often used for diagnosing sexually transmitted diseases (STDs). A pseudo-outbreak of pharyngeal gonorrhoea in a group of prostitutes turned out to have been caused by false-posi

  2. 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....

  3. High prevalence of false-positive plateau phenomena during VO2max testing in adolescents.

    Science.gov (United States)

    Beltrami, Fernando G; Wong, Del P; Noakes, Timothy D

    2014-09-01

    It is believed that a plateau in oxygen consumption (VO2) at the end of an incremental exercise test identifies the upper limits of cardiovascular capacity. We investigated how different criteria influence the frequency with which the "plateau phenomenon" is detected and the prevalence at which "false" plateau phenomena occurs during sub-maximal exercise. Cross-sectional. Six different criteria with 3 different sampling intervals each were used to identify the "plateau phenomenon" from a single data set comprising 63 incremental exercise tests along with secondary criteria based on target heart rate (HR) and respiratory exchange ratio (RER). A single criterion from the original 18 (HALF) was also used to detect the incidence of any plateau phenomena during each test. The plateau phenomenon was detected in 16-82% of the tests depending on the criteria used, mostly as a result of the different sampling intervals. HALF identified 103 "plateau phenomena" but 73 (70.9%) of these occurred during sub-maximal exercise and so were "false". "False" plateaus were verified by at least one secondary criterion in 27% of cases. Participants reached the HR and RER targets after 83.6 ± 11.7% and 81.9 ± 18.1% of total test duration, respectively. The wide range in the percentage of plateau phenomena detected by different criteria plus the high rate (71%) of "false" plateau during sub-maximal exercise could indicate that this phenomenon is a calculation artifact rather than an indicator of true physiological events. Secondary criteria can be reached early in exercise and often identify "false" plateau phenomena as "true". Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  4. 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.)

  5. A False Positive Dengue Fever Rapid Diagnostic Test Result in a Case of Acute Parvovirus B19 Infection.

    Science.gov (United States)

    Izumida, Toshihide; Sakata, Hidenao; Nakamura, Masahiko; Hayashibara, Yumiko; Inasaki, Noriko; Inahata, Ryo; Hasegawa, Sumiyo; Takizawa, Takenori; Kaya, Hiroyasu

    2016-01-01

    An outbreak of dengue fever occurred in Japan in August 2014. We herein report the case of a 63-year-old man who presented with a persistent fever in September 2014. Acute parvovirus B19 infection led to a false positive finding of dengue fever on a rapid diagnostic test (Panbio Dengue Duo Cassette(TM)). To the best of our knowledge, there are no previous reports of a false positive result for dengue IgM with the dengue rapid diagnostic test. We believe that epidemiological information on the prevalence of parvovirus B19 is useful for guiding the interpretation of a positive result with the dengue rapid diagnostic test.

  6. A Pattern Matching Algorithm for Reducing False Positive in Signature Based Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    T. Sree Kala,

    2016-04-01

    Full Text Available Nowadays the organizations are facing the number of threats every day in the form of viruses and attack etc. Since many different mechanisms were preferred by organizations in the form of intrusion detection and prevention system to protect its organizations from these kinds of attacks. Intrusion Detection System (IDS is considered as a system integrated with intelligent subsystems. In this paper the signature based intrusion detection system is discussed. There are different pattern matching algorithms available to detect intrusion. Brute force and Knuth-Morris-Pratt are the single keyword pattern matching algorithms. If one or more occurrence of pattern present in the input text, then there is an intrusion and the intrusion alarm will be sent. The occurrence of false alarm will be high in intrusion detection. In this paper the string matching algorithm to reduce the percentage of false alarm will be discussed.

  7. Positive Psychology and Adolescent Mental Health: False Promise or True Breakthrough?

    Science.gov (United States)

    Kelley, Thomas M.

    2004-01-01

    The emerging field of positive psychology has pledged to improve the mental health of American adolescents. Yet, without a principle-based conceptual foundation to guide its study of optimal youth functioning, positive psychology will ultimately fail to keep its promise. This paper suggests that the principles of Mind, Thought and Consciousness…

  8. Positive Psychology and Adolescent Mental Health: False Promise or True Breakthrough?

    Science.gov (United States)

    Kelley, Thomas M.

    2004-01-01

    The emerging field of positive psychology has pledged to improve the mental health of American adolescents. Yet, without a principle-based conceptual foundation to guide its study of optimal youth functioning, positive psychology will ultimately fail to keep its promise. This paper suggests that the principles of Mind, Thought and Consciousness…

  9. Asymptotically false-positive-maximizing attack on non-binary Tardos codes

    CERN Document Server

    Simone, Antonino

    2011-01-01

    We use a method recently introduced by Simone and Skoric to study accusation probabilities for non-binary Tardos fingerprinting codes. We generalize the pre-computation steps in this approach to include a broad class of collusion attack strategies. We analytically derive properties of a special attack that asymptotically maximizes false accusation probabilities. We present numerical results on sufficient code lengths for this attack, and explain the abrupt transitions that occur in these results.

  10. [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.

  11. False positives and false negatives measure less than 0.001% in labeling ssDNA with osmium tetroxide 2,2’-bipyridine

    Directory of Open Access Journals (Sweden)

    Anastassia Kanavarioti

    2016-10-01

    Full Text Available Osmium tetroxide 2,2’-bipyridine (OsBp is known to react with pyrimidines in ssDNA and preferentially label deoxythymine (T over deoxycytosine (C. The product, osmylated DNA, was proposed as a surrogate for nanopore-based DNA sequencing due to OsBp’s “perfect” label attributes. Osmylated deoxyoligos translocate unassisted and measurably slow via sub-2 nm SiN solid-state nanopores, as well as via the alpha-hemolysin (α-HL pore. Both nanopores discriminate clearly between osmylated and intact nucleobase; α-HL was also shown to discriminate between osmylated T and osmylated C. Experiments presented here confirm that the kinetics of osmylation are comparable for short oligos and long ssDNA and show that pyrimidine osmylation is practically complete in two hours at room temperature with less than 15 mM OsBp. Under the proposed labeling conditions: deoxyoligo backbone degradation measures less than 1/1,000,000; false positives such as osmylated deoxyadenine (A and osmylated deoxyguanine (G measure less than 1/100,000; false negatives, i.e., unosmylated C measure less than 1/10,000; and unosmylated T must measure substantially lower than 1/10,000 due to the 27-fold higher reactivity of T compared to C. However, osmylated C undergoes degradation that amounts to about 1–2% for the duration of the labeling protocol. This degradation may be further characterized, possibly suppressed, and the properties of the degradation products via nanopore translocation can be evaluated to assure base calling quality in a DNA sequencing effort.

  12. 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...... 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....... 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...

  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 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 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.

    2013-01-01

    Detection and quantitation of protein-ligand binding interactions is important in many areas of biological research. The Stability of Proteins from Rates of Oxidation (SPROX) technique 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 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. PMID:24114261

  15. [Serologic study on the prevalence of HIV, HBV infection and on the false positive reaction of VDRL at a prison].

    Science.gov (United States)

    Capoccia, A; Ranieri, R; Busnelli, M; Passaretti, B; Milella, A M; Vecchi, L

    1991-03-01

    Prisoners are considered to be a high risk population for HIV and HBV infection. Aim of this study was to determine the prevalence of HIV, HBV infection and of the VDRL false positivity by performing screening tests in 496 prisoners of Monza in 1987. About a third of prisoners was HIV infected (with a high prevalence in drug addicts) and about a half had a contact with HBV virus. We observed a very common association between HIV and HBV infections. About ten per cent of HIV infected presented a false positivity for VDRL while one per cent of not infected did. Our data show that in Italian prison HIV and HBV infections are spreadly diffused. False positivity for VDRL may be due not only to drug addiction but also to the immunological variations connected with AIDS.

  16. 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.

  17. 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.

  18. 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.

  19. Urease-positive bacteria in the stomach induce a false-positive reaction in a urea breath test for diagnosis of Helicobacter pylori infection.

    Science.gov (United States)

    Osaki, Takako; Mabe, Katsuhiro; Hanawa, Tomoko; Kamiya, Shigeru

    2008-07-01

    This study investigated the influence of urease-positive non-Helicobacter pylori bacteria on the results of a urea breath test (UBT) to evaluate the diagnostic utility of a UBT using film-coated [(13)C]urea tablets. The UBT was performed in 102 patients treated with a proton pump inhibitor and antibiotics for the eradication of H. pylori. Urease-producing bacteria other than H. pylori were isolated and identified from the oral cavity and stomach. In 4/102 patients, the UBT gave false-positive results. These false-positive results were found to be caused by the presence of urease-positive bacteria in the oral cavity and stomach. Five bacterial species with urease activity (Proteus mirabilis, Citrobacter freundii, Klebsiella pneumoniae, Enterobacter cloacae and Staphylococcus aureus) were subsequently isolated from the oral cavity and/or stomach. As there was no correlation between the in vitro urease activity of urease-positive non-H. pylori bacteria and the UBT value, and all of the patients with a false-positive UBT result were suffering from atrophic gastritis, it is possible that the false-positive results in the UBT were a result of colonization of urease-positive bacteria and gastric hypochlorhydric conditions. Thus, for the diagnosis of H. pylori infection using a UBT, the influence of stomach bacteria must be considered when interpreting the results.

  20. Sporadic bilateral adrenal medullary hyperplasia: apparent false positive MIBG scan and expected MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Yung, Babington C.K.; Loke, Tony K.L.; Tse, T.W.; Tsang, M.W.; Chan, James C.S. E-mail: jcschan@ha.org.hk

    2000-10-01

    Adrenal medullary hyperplasia is a rare cause of clinical symptoms and biochemical findings identical to pheochromocytoma occurring mostly in multiple endocrine neoplasia patients. The scenario of positive MIBG scan, but no focal lesion found on CT and MRI led to diagnostic and management difficulties. Like pheochromocytoma, surgical excision can lead to clinical and biochemical recovery. We report this unusual case of sporadic bilateral adrenal medullary hyperplasia, with hypertension and biochemical abnormalities alleviated after surgical adrenalectomy. Based on T2 values reported in literature, high signal focal lesions may not appear on T2-weighted MRI images until development of frank pheochromocytoma. MIBG scan remains the most sensitive imaging modality for this condition.

  1. Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment.

    Directory of Open Access Journals (Sweden)

    Darren Boone

    Full Text Available PURPOSE: To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC for colorectal cancer screening. MATERIALS AND METHODS: Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between "standard" CTC and "enhanced" CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses. RESULTS: Data from 122 participants were analysed. There were 30 (25% non-traders for the cancer scenario and 20 (16% for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to >85 drop in specificity, equating to 2250 (IQR 1250 to >4250 additional false-positives per additional true-positive cancer, at 0.2% prevalence. For polyps, the figure was 15% (IQR 7.5 to 55, equating to 6 (IQR 3 to 22 additional false-positives per additional true-positive polyp, at 25% prevalence. Tipping points were significantly higher for patients than professionals for both cancer (85 vs 25, p<0.001 and polyps (55 vs 15, p<0.001. Patients were willing to pay significantly more for increased sensitivity for cancer (p = 0.021. CONCLUSION: When screening for colorectal cancer, patients and professionals believe gains in true-positive diagnoses are worth much more than the negative consequences of a corresponding rise in false-positives. Evaluation of screening tests should account for this.

  2. 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.

  3. The impact of a false-positive MRI on the choice for mastectomy in BRCA mutation carriers is limited.

    NARCIS (Netherlands)

    Hoogerbrugge-van der Linden, N.; Kamm, Y.J.; Bult, P.; Landsbergen, K.M.; Bongers, E.M.; Brunner, H.G.; Bonenkamp, H.J.; Hullu, JA de; Ligtenberg, M.J.; Boetes, C.

    2008-01-01

    PURPOSE: To assess the false-positive rate of breast cancer surveillance by magnetic resonance imaging (MRI) in BRCA mutation carriers and the impact of an abnormal mammography or breast MRI on the patients' decision for prophylactic mastectomy. PATIENTS AND METHODS: A total of 196 BRCA mutation

  4. 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

  5. Doctor can't make lab pay damages for false-positive HIV test.

    Science.gov (United States)

    1997-08-22

    The Texas Court of Appeals ruled that physician [name removed] was not eligible for damages from a laboratory that misreported HIV test results for one of her patients. [Name removed] sued Pathlab, Inc., a laboratory that had a policy of performing an ELISA test and a Western blot test, but that only reported the ELISA result unless a physician specifically requested and paid for the Western blot results. One of Dr. [name removed]'s patients was diagnosed as HIV-positive in error; the patient sued [name removed] and Pathlab. All claims against Dr. [name removed] were dismissed. The court ruled that Dr. [name removed] could not seek damages against Pathlab because this would have amounted to an improper attempt to gain indemnification.

  6. 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.

  7. Distinguishing binders from false positives by free energy calculations: fragment screening against the flap site of HIV protease.

    Science.gov (United States)

    Deng, Nanjie; Forli, Stefano; He, Peng; Perryman, Alex; Wickstrom, Lauren; Vijayan, R S K; Tiefenbrunn, Theresa; Stout, David; Gallicchio, Emilio; Olson, Arthur J; Levy, Ronald M

    2015-01-22

    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.

  8. 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.

  9. A new yield simulator for transiting planets and false positives: application to the Next Generation Transit Survey

    Science.gov (United States)

    Günther, Maximilian N.; Queloz, Didier; Demory, Brice-Olivier; Bouchy, Francois

    2017-03-01

    We present a yield simulator to predict the number and characteristics of planets, false positives and false alarms in transit surveys. The simulator is based on a galactic model and the planet occurrence rates measured by the Kepler mission. It takes into account the observation window function and measured noise levels of the investigated survey. Additionally, it includes vetting criteria to identify false positives. We apply this simulator to the Next Generation Transit Survey (NGTS), a wide-field survey designed to detect transiting Neptune-sized exoplanets. We find that red noise is the main limitation of NGTS up to 14 mag, and that its obtained level determines the expected yield. Assuming a red noise level of 1 mmag, the simulation predicts the following for a 4-yr survey: 4 ± 3 Super-Earths, 19 ± 5 Small Neptunes, 16 ± 4 Large Neptunes, 55 ± 8 Saturn-sized planets and 150 ± 10 Jupiter-sized planets, along with 4688 ± 45 eclipsing binaries and 843 ± 75 background eclipsing binaries. We characterize the properties of these objects to enhance the early identification of false positives and discuss follow-up strategies for transiting candidates.

  10. Concurrent combined verification: reducing false positives in automated NMR structure verification through the evaluation of multiple challenge control structures.

    Science.gov (United States)

    Golotvin, Sergey S; Pol, Rostislav; Sasaki, Ryan R; Nikitina, Asya; Keyes, Philip

    2012-06-01

    Automated structure verification using (1)H NMR data or a combination of (1)H and heteronuclear single-quantum correlation (HSQC) data is gaining more interest as a routine application for qualitative evaluation of large compound libraries produced by synthetic chemistry. The goal of this automated software method is to identify a manageable subset of compounds and data that require human review. In practice, the automated method will flag structure and data combinations that exhibit some inconsistency (i.e. strange chemical shifts, conflicts in multiplicity, or overestimated and underestimated integration values) and validate those that appear consistent. One drawback of this approach is that no automated system can guarantee that all passing structures are indeed correct structures. The major reason for this is that approaches using only (1)H or even (1)H and HSQC spectra often do not provide sufficient information to properly distinguish between similar structures. Therefore, current implementations of automated structure verification systems allow, in principle, false positive results. Presented in this work is a method that greatly reduces the probability of an automated validation system passing incorrect structures (i.e. false positives). This novel method was applied to automatically validate 127 non-proprietary compounds from several commercial sources. Presented also is the impact of this approach on false positive and false negative results.

  11. Pokorny's complaint: the insoluble problem of the overwhelming number of false positives generated by suicide risk assessment

    Science.gov (United States)

    Nielssen, Olav; Wallace, Duncan; Large, Matthew

    2017-01-01

    Alex Pokorny's 1983 prospective study of suicide found that 96.3% of high-risk predictions were false positives, and that more than half of the suicides occurred in the low-risk group and were hence false negatives. All subsequent prospective studies, including the recent US Army Study To Assess Risk and Resilience in Servicemembers (STARRS), have reported similar results. We argue that since risk assessment cannot be a practical basis for interventions aimed at reducing suicide, the alternative is for mental health services to carefully consider what amounts to an adequate standard of care, and to adopt the universal precaution of attempting to provide that to all of our patients.

  12. 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.

  13. Kepler Eclipsing Binary Stars. VIII. Identification of False Positive Eclipsing Binaries and Re-extraction of New Light Curves

    CERN Document Server

    Abdul-Masih, Michael; Conroy, Kyle; Bloemen, Steven; Boyajian, Tabetha; Doyle, Laurance R; Johnston, Cole; Kostov, Veselin; Latham, David W; Matijevic, Gal; Shporer, Avi; Southworth, John

    2016-01-01

    The Kepler Mission has provided unprecedented, nearly continuous photometric data of $\\sim$200,000 objects in the $\\sim$105 deg$^{2}$ field of view from the beginning of science operations in May of 2009 until the loss of the second reaction wheel in May of 2013. The Kepler Eclipsing Binary Catalog contains information including but not limited to ephemerides, stellar parameters and analytical approximation fits for every known eclipsing binary system in the Kepler Field of View. Using Target Pixel level data collected from Kepler in conjunction with the Kepler Eclipsing Binary Catalog, we identify false positives among eclipsing binaries, i.e. targets that are not eclipsing binaries themselves, but are instead contaminated by eclipsing binary sources nearby on the sky and show eclipsing binary signatures in their light curves. We present methods for identifying these false positives and for extracting new light curves for the true source of the observed binary signal. For each source, we extract three separa...

  14. Using the minimum description length principle to reduce the rate of false positives of best-fit algorithms.

    Science.gov (United States)

    Fang, Jie; Ouyang, Hongjia; Shen, Liangzhong; Dougherty, Edward R; Liu, Wenbin

    2014-12-01

    The inference of gene regulatory networks is a core problem in systems biology. Many inference algorithms have been proposed and all suffer from false positives. In this paper, we use the minimum description length (MDL) principle to reduce the rate of false positives for best-fit algorithms. The performance of these algorithms is evaluated via two metrics: the normalized-edge Hamming distance and the steady-state distribution distance. Results for synthetic networks and a well-studied budding-yeast cell cycle network show that MDL-based filtering is more effective than filtering based on conditional mutual information (CMI). In addition, MDL-based filtering provides better inference than the MDL algorithm itself.

  15. Association between Immunoglobulin GM and KM Genotypes and Placental Malaria in HIV-1 Negative and Positive Women in Western Kenya

    Science.gov (United States)

    Iriemenam, Nnaemeka C.; Pandey, Janardan P.; Williamson, John; Blackstock, Anna J.; Yesupriya, Ajay; Namboodiri, Aryan M.; Rocca, Keith M.; van Eijk, Anna Maria; Ayisi, John; Oteino, Juliana; Lal, Renu B.; ter Kuile, Feiko O.; Steketee, Richard; Nahlen, Bernard; Slutsker, Laurence; Shi, Ya Ping

    2013-01-01

    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. PMID

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

    Science.gov (United States)

    Iriemenam, Nnaemeka C; Pandey, Janardan P; Williamson, John; Blackstock, Anna J; Yesupriya, Ajay; Namboodiri, Aryan M; Rocca, Keith M; van Eijk, Anna Maria; Ayisi, John; Oteino, Juliana; Lal, Renu B; ter Kuile, Feiko O; Steketee, Richard; Nahlen, Bernard; Slutsker, Laurence; Shi, Ya Ping

    2013-01-01

    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.

  17. Do one-time intracompartmental pressure measurements have a high false-positive rate in diagnosing compartment syndrome?

    Science.gov (United States)

    Whitney, Augusta; O'Toole, Robert V; Hui, Emily; Sciadini, Marcus F; Pollak, Andrew N; Manson, Theodore T; Eglseder, W Andrew; Andersen, Romney C; Lebrun, Christopher; Doro, Christopher; Nascone, Jason W

    2014-02-01

    Intracompartmental pressure measurements are frequently used in the diagnosis of compartment syndrome, particularly in patients with equivocal or limited physical examination findings. Little clinical work has been done to validate the clinical use of intracompartmental pressures or identify associated false-positive rates. We hypothesized that diagnosis of compartment syndrome based on one-time pressure measurements alone is associated with a high false-positive rate. Forty-eight consecutive patients with tibial shaft fractures who were not suspected of having compartment syndrome based on physical examinations were prospectively enrolled. Pressure measurements were obtained in all four compartments at a single point in time immediately after induction of anesthesia using a pressure-monitoring device. Preoperative and intraoperative blood pressure measurements were recorded. The same standardized examination was performed by the attending surgeon preoperatively, postoperatively, and during clinical follow-up for 6 months to assess clinical evidence of acute or late compartment syndrome. No clinical evidence of compartment syndrome was observed postoperatively or during follow-up until 6 months after injury. Using the accepted criteria of delta P of 30 mm Hg from preoperative diastolic blood pressure, 35% of cases (n = 16; 95% confidence interval, 21.5-48.5%) met criteria for compartment syndrome. Raising the threshold to delta P of 20 mm Hg reduced the false-positive rate to 24% (n = 11; 95% confidence interval, 11.1-34.9%). Twenty-two percent (n = 10; 95% confidence interval, 9.5-32.5%) exceeded absolute pressure of 45 mm Hg. A 35% false-positive rate was found for the diagnosis of compartment syndrome in patients with tibial shaft fractures who were not thought to have compartment syndrome by using currently accepted criteria for diagnosis based solely on one-time compartment pressure measurements. Our data suggest that reliance on one-time intracompartmental

  18. Differential Gene Expression Segregates Cattle Confirmed Positive for Bovine Tuberculosis from Antemortem Tuberculosis Test-False Positive Cattle Originating from Herds Free of Bovine Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ailam Lim

    2012-01-01

    Full Text Available Antemortem tests for bovine tuberculosis (bTB currently used in the US measure cell-mediated immune responses against Mycobacterium bovis. Postmortem tests for bTB rely on observation of gross and histologic lesions of bTB, followed by bacterial isolation or molecular diagnostics. Cumulative data from the state of Michigan indicates that 98 to 99% of cattle that react positively in antemortem tests are not confirmed positive for bTB at postmortem examination. Understanding the fundamental differences in gene regulation between antemortem test-false positive cattle and cattle that have bTB may allow identification of molecular markers that can be exploited to better separate infected from noninfected cattle. An immunospecific cDNA microarray was used to identify altered gene expression (≤0.01 of 122 gene features between antemortem test-false positive cattle and bTB-infected cattle following a 4-hour stimulation of whole blood with tuberculin. Further analysis using quantitative real-time PCR assays validated altered expression of 8 genes that had differential power (adj  ≤0.05 to segregate cattle confirmed positive for bovine tuberculosis from antemortem tuberculosis test-false positive cattle originating from herds free of bovine tuberculosis.

  19. 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. PMID:26342055

  20. [False positive result in mammography and its association with the presence of obesity: a case-control study].

    Science.gov (United States)

    Castro-Ibarra, Marisela; Menchaca-Díaz, Rufino; Cabrales-Ruvalcaba, J Jesús; Luna-V Gómez, Rosa Alicia

    2016-01-01

    To analyze the association between a false positive result in mammography and obesity, inside the breast cancer early detection program in women affiliated to the Institute of Security and Social Services for Government and Municipality workers of the State of Baja California (ISSSTECALI). A case-control, retrospective study was done in women affiliated to ISSSTECALI to whom a mammography was performed between 2009 and 2012. Women with a false positive result in mammography were included as cases. Controls were women with a true negative result in mammography. Three controls were randomly selected for each case. Obesity was established with the body mass index (BMI) consigned in the woman's clinical file. Age and estrogen replacement therapy were included as co-variables. Seventy nine cases were identified and 237 controls were included. Obesity was observed in 54.4% of cases and in 41.3% of controls (odds ratio: 1.69; 95% confidence interval for odds ratio: 1.01-2.82; p value: 0.043). A logistic regression model including covariables maintained the observed association (p = 0.044). No association was found with analyzed co-variables. A false positive result in mammography was associated with the presence of obesity.

  1. 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.

  2. To control false positives in gene-gene interaction analysis: two novel conditional entropy-based approaches.

    Directory of Open Access Journals (Sweden)

    Xiaoyu Zuo

    Full Text Available Genome-wide analysis of gene-gene interactions has been recognized as a powerful avenue to identify the missing genetic components that can not be detected by using current single-point association analysis. Recently, several model-free methods (e.g. the commonly used information based metrics and several logistic regression-based metrics were developed for detecting non-linear dependence between genetic loci, but they are potentially at the risk of inflated false positive error, in particular when the main effects at one or both loci are salient. In this study, we proposed two conditional entropy-based metrics to challenge this limitation. Extensive simulations demonstrated that the two proposed metrics, provided the disease is rare, could maintain consistently correct false positive rate. In the scenarios for a common disease, our proposed metrics achieved better or comparable control of false positive error, compared to four previously proposed model-free metrics. In terms of power, our methods outperformed several competing metrics in a range of common disease models. Furthermore, in real data analyses, both metrics succeeded in detecting interactions and were competitive with the originally reported results or the logistic regression approaches. In conclusion, the proposed conditional entropy-based metrics are promising as alternatives to current model-based approaches for detecting genuine epistatic effects.

  3. Application of computer-extracted breast tissue texture features in predicting false-positive recalls from screening mammography

    Science.gov (United States)

    Ray, Shonket; Choi, Jae Y.; Keller, Brad M.; Chen, Jinbo; Conant, Emily F.; Kontos, Despina

    2014-03-01

    Mammographic texture features have been shown to have value in breast cancer risk assessment. Previous models have also been developed that use computer-extracted mammographic features of breast tissue complexity to predict the risk of false-positive (FP) recall from breast cancer screening with digital mammography. This work details a novel locallyadaptive parenchymal texture analysis algorithm that identifies and extracts mammographic features of local parenchymal tissue complexity potentially relevant for false-positive biopsy prediction. This algorithm has two important aspects: (1) the adaptive nature of automatically determining an optimal number of region-of-interests (ROIs) in the image and each ROI's corresponding size based on the parenchymal tissue distribution over the whole breast region and (2) characterizing both the local and global mammographic appearances of the parenchymal tissue that could provide more discriminative information for FP biopsy risk prediction. Preliminary results show that this locallyadaptive texture analysis algorithm, in conjunction with logistic regression, can predict the likelihood of false-positive biopsy with an ROC performance value of AUC=0.92 (pclinical implications of using prediction models incorporating these texture features may include the future development of better tools and guidelines regarding personalized breast cancer screening recommendations. Further studies are warranted to prospectively validate our findings in larger screening populations and evaluate their clinical utility.

  4. Hepatitis C virus infection and biological false-positive syphilis test:a single-center experience

    Institute of Scientific and Technical Information of China (English)

    Wei-Fang Zhu; Shui-Ying Lei; Lan-Juan Li

    2011-01-01

    BACKGROUND: Rapidplasmaregainpositiveand/ortreponema pallidum hemagglutination negative [RPR(+)/TPHA(-)] results were designated as biologic false-positive (BFP). There are limited data about BFP reactions against syphilis in patients with hepatitis C virus (HCV) infection. This study aimed to determine the prevalence of BFP reactions for syphilis in patients with HCV infection in a large sample and assess the relationship between BFP reactions and HCV infection. METHODS:  A total of 2656 patients with positive anti-HCV and 5600 healthy control subjects were enrolled in this study. Hepatitis C serology was determined by a second generation ELISA test for HCV antibody. Syphilis serology was determined by the RPR test. Those subjects with reactive RPR positive underwent the TPHA test. Demographics and laboratory data were collected by trained clinicians. RESULTS: Among 2656 patients, 111 (4.2%) had a reactive RPR test. Of the 111 patients who were subjected to reactive RPR test, 30 (27.0%) showed HCV(+)/RPR(+). Of 5600 healthy controls, 80 (1.4%) had a reactive RPR test. Fourteen (17.5%) controls with HCV(-)/RPR(+) had a non-reactive TPHA test. These represented 1.1% of all HCV-positive and 0.3% of all HCV-negative subjects (P0.05). CONCLUSIONS: The data of this study demonstrate that HCV infection is associated with a false-positive RPR test. In this study BFPs were significantly more common in HCV positive patients compared to HCV-negative ones. Eosinophil abnormality can be considered as a predictor for BFP. Excessive BFPs must be considered in assessing the frequency of syphilis in a HCV-positive population and the importance of the treponemal specific serologic test should be emphasized for a diagnosis of syphilis in such population.

  5. The clinical impact of a false-positive urine cocaine screening result on a patient's pain management.

    Science.gov (United States)

    Kim, James A; Ptolemy, Adam S; Melanson, Stacy E F; Janfaza, David R; Ross, Edgar L

    2015-06-01

    The urine of a patient admitted for chest and epigastric pain tested positive for cocaine using an immunoassay-based drug screening method (positive/negative cutoff concentration 150 ng/mL). Despite the patient's denial of recent cocaine use, this positive cocaine screening result in conjunction with a remote history of drug misuse impacted the patient's recommended pain therapy. Specifically, these factors prompted the clinical team to question the appropriateness of opioids and other potentially addictive therapeutics during the treatment of cancer pain from previously undetected advanced pancreatic carcinoma. After pain management and clinical pathology consultation, it was decided that the positive cocaine screening result should be confirmed by gas chromatography-mass spectrometry (GC-MS) testing. This more sensitive and specific analytical technique revealed that both cocaine and its primary metabolite benzoylecgonine were undetectable (i.e., less than the assay detection limit of 50 ng/mL), thus indicating that the positive urine screening result was falsely positive. With this confirmation, the pain management service team was reassured in offering intrathecal pump (ITP) therapy for pain control. ITP implantation was well tolerated, and the patient eventually achieved excellent pain relief. However, ITP therapy most likely would not have been utilized without the GC-MS confirmation testing unless alternative options failed and extensive vigilant monitoring was initiated. As exemplified in this case, confirmatory drug testing should be performed on specimens with unexpected immunoassay-based drug screening results. To our knowledge, this is the first report of a false-positive urine cocaine screening result and its impact on patient management. Wiley Periodicals, Inc.

  6. A New Yield Simulator for Transiting Planets and False Positives: Application to the Next Generation Transit Survey

    CERN Document Server

    Günther, Maximilian N; Demory, Brice-Olivier; Bouchy, Francois

    2016-01-01

    We present a yield simulator to predict the number and characteristics of planets, false positives and false alarms in transit surveys. The simulator is based on a galactic model and the planet occurrence rates measured by the Kepler mission. It takes into account the observation window function and measured noise levels of the investigated survey. Additionally, it includes vetting criteria to identify false positives. We apply this simulator to the Next Generation Transit Survey (NGTS), a wide-field survey designed to detect transiting Neptune-sized exoplanets. We find that red noise is the main limitation of NGTS up to 14th magnitude, and that its obtained level determines the expected yield. Assuming a red noise level of 1 mmag, the simulation predicts the following for a four-year survey: 4+-3 Super-Earths, 19+-5 Small Neptunes, 16+-4 Large Neptunes, 55+-8 Saturn-sized planets and 150+-10 Jupiter-sized planets, along with 4688+-45 eclipsing binaries and 843+-75 background eclipsing binaries. We characteri...

  7. False positive VDRL (BFP-STS) and systemic lupus erythematosus; new data in clinico-laboratory associations.

    Science.gov (United States)

    Al Attia, Haider M

    2002-12-01

    To investigate the relationships between clinical features and serological parameters in systemic lupus erythematosus (SLE) patients with false positive venereal disease research laboratory (VDRL) test (BFP-STS) and those without. The records of 74 patients with SLE were reviewed. These were divided on the basis of the presence of a biologically false positive serological test (BFP-STS) (n = 18) or its absence (n = 56). The clinical features and serological parameters were subsequently evaluated in each group. A biologically false positive serological test was found in 18 patients (24.5%). Clinically, they had a significantly higher frequency of malar rash (P < 0.02), hemolytic anaemia (P < 0.02) and SLE-related antiphospholipid (APL) syndrome (P < 0.02). Neuropsychiatric lupus was more frequent in the group without BFP-STS. Moreover, subacute cutaneous LE (SCLE), Raynaud's phenomenon, livedo reticularis (LR) and cardiopulmonary complications were present only in the latter group. There was no significant association between BFP-STS and other autoantibodies including Extractable nuclear antigen (ENAs), however, there was a significant association with C3 hypocomplementemia (P < 0.05). Half of the patients with BFP-STS were positive for anticardiolipin antibodies (aCL Abs) vs. 28% in the negative group (P = NS). The study suggests that the clinical and serological relevance of BFP-STS in lupus patients may vary from those described in relation to other antiphospholipid determinants. Our patients appeared to have sparing of certain major organ systems, yet there was a greater tendency to developing Antiphospholipid (APL) syndrome and hemolytic anaemia.

  8. Yersinia enterocolitica serotype O:9 cultured from Swedish sheep showing serologically false-positive reactions for Brucella melitensis.

    Science.gov (United States)

    Chenais, Erika; Bagge, Elisabeth; Lambertz, Susanne Thisted; Artursson, Karin

    2012-01-01

    In a herd of 20 sheep in Sweden, a country where brucellosis has never been diagnosed in sheep or goats, a total of six sheep were found serologically positive to Brucella melitensis in two different rounds of sampling. Yersinia enterocolitica serotype O:9 could at the time of the second sampling be isolated from four sheep, one of them at the same time serologically positive for B. melitensis. The article describes the case and gives some background information on brucellosis and Y. enterocolitica in general as well as a more specific description of the Swedish surveillance program for B. melitensis and the test procedures used. The problem with false-positive reactions, in particular its implications for surveillance programs in low prevalence or officially brucellosis-free countries, is discussed.

  9. Six consecutive false positive cases from cell-free fetal DNA testing in a single referring centre

    Science.gov (United States)

    Dugo, Nella; Padula, Francesco; Mobili, Luisa; Brizzi, Cristiana; D’Emidio, Laura; Cignini, Pietro; Mesoraca, Alvaro; Bizzoco, Domenico; Cima, Antonella; Giorlandino, Claudio

    2014-01-01

    Introduction recent studies have proposed the introduction of cell-free fetal DNA testing (NIPT-Non Invasive Prenatal Testing) in routine clinical practice emphasizing its high sensibility and specificity. In any case, false positive and false negative findings may result from placental mosaicism, because cell-free fetal DNA originates mainly from placenta. Case we report six cases of women who underwent chorionic villus sampling (CVS) or amniocentesis to confirm the results from NIPT: two Turner syndromes, two Triple X, one Patau syndrome, one Edward syndrome. Results using classic cytogenetic analysis and, also, Array - Comparative Genomic Hybridization (Array CGH) the karyotype of all 5 fetuses was found to be normal. Conclusion results from NIPT must always be confirmed by invasive prenatal diagnosis. It is mandatory to inform the patient that the CVS and amniocentesis still represent the only form of prenatal diagnostic test available. PMID:25332757

  10. 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.

  11. 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

  12. Kepler Eclipsing Binary Stars. VIII. Identification of False Positive Eclipsing Binaries and Re-extraction of New Light Curves

    Science.gov (United States)

    Abdul-Masih, Michael; Prša, Andrej; Conroy, Kyle; Bloemen, Steven; Boyajian, Tabetha; Doyle, Laurance R.; Johnston, Cole; Kostov, Veselin; Latham, David W.; Matijevič, Gal; Shporer, Avi; Southworth, John

    2016-04-01

    The Kepler mission has provided unprecedented, nearly continuous photometric data of ∼200,000 objects in the ∼105 deg2 field of view (FOV) from the beginning of science operations in May of 2009 until the loss of the second reaction wheel in May of 2013. The Kepler Eclipsing Binary Catalog contains information including but not limited to ephemerides, stellar parameters, and analytical approximation fits for every known eclipsing binary system in the Kepler FOV. Using target pixel level data collected from Kepler in conjunction with the Kepler Eclipsing Binary Catalog, we identify false positives among eclipsing binaries, i.e., targets that are not eclipsing binaries themselves, but are instead contaminated by eclipsing binary sources nearby on the sky and show eclipsing binary signatures in their light curves. We present methods for identifying these false positives and for extracting new light curves for the true source of the observed binary signal. For each source, we extract three separate light curves for each quarter of available data by optimizing the signal-to-noise ratio, the relative percent eclipse depth, and the flux eclipse depth. We present 289 new eclipsing binaries in the Kepler FOV that were not targets for observation, and these have been added to the catalog. An online version of this catalog with downloadable content and visualization tools is maintained at http://keplerEBs.villanova.edu.

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

    Science.gov (United States)

    Hannoush, Zeina C.; Palacios, Juan D.; Kuker, Russ A.

    2017-01-01

    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. PMID:28246564

  14. 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.)

  15. Balancing the false negative and positive rates in suspect screening with high-resolution Orbitrap mass spectrometry using multivariate statistics.

    Science.gov (United States)

    Vergeynst, Leendert; Van Langenhove, Herman; Demeestere, Kristof

    2015-02-17

    Modern high-resolution mass spectrometry (HRMS) enables full-spectrum trace level analysis of emerging environmental organic contaminants. This raises the opportunity for post-acquisition suspect screening when no reference standards are a priori available. When setting up a conventional screening identification train based on successively different identification criteria including mass error and isotope fit, the false negative rate typically accumulates upon advancing through the decision tree. The challenge is thus to elaborate a well-balanced screening, in which the different criteria are equally stringent, leading to a controllable number of false negatives. Presented is a novel suspect screening approach using liquid-chromatography Orbitrap HRMS. Based on a multivariate statistical model, the screening takes into account the accurate mass error of the mono isotopic ion and up to three isotopes, isotope ratios, and a peak/noise filter. As such, for the first time, controlling the overall false negative rate of the screening algorithm to a desired level (5% in this study) is achieved. Simultaneously, a well-balanced identification decision is guaranteed taking the different identification criteria as a whole in a holistic statistical approach. Taking into account 1, 2, and 3 isotopes decreases the false positive rate from 22, 2.8 to <0.3%, but the cost of increasing the median limits of identification from 200, 2000 to 2062 ng L(-1), respectively, should also be considered. As proof of concept, 7 biologically treated wastewaters were screened toward 77 suspect pharmaceuticals resulting in the indicative identification of 25 suspects. Subsequently obtained reference standards allowed confirmation for 19 out of these 25 pharmaceutical contaminants.

  16. General false positive ELISA reactions in visceral leishmaniasis. Implications for the use of enzyme immunoassay analyses in tropical Africa.

    Science.gov (United States)

    Elshafie, Amir I; Mullazehi, Mohammed; Rönnelid, Johan

    2016-04-01

    Leishmaniasis is a neglected disease in tropical countries. Clinical and laboratory features may mimic autoimmune diseases and this can complicate the Leishmania diagnosis. Due to our previous investigation for false anti-CCP2 reactivity in Leishmania-infected subjects and our interest in immunity against the joint-specific collagen type II (CII) in rheumatoid arthritis (RA) we investigated the same cohort for anti-CII antibodies. We found elevated anti-CII reactivity in Leishmania-infected patients as compared to controls. When anti-CII OD values were compared with BSA-blocked control plates we found higher reactivity against BSA than in CII-coated plates in many Leishmania-infected patients. The percentage of such false positive anti-CII reactions increased with inflammatory activity, and was found in almost all Leishmania patients with highly active inflammatory disease, but was as low in Sudanese healthy controls as well as among Swedish RA patients. The correlation coefficients between false positive anti-CII and anti-CCP2 measured with a commercial ELISA were highest for patients with the most inflammatory disease but non-significant for Sudanese controls and Swedish RA patients, arguing that our findings may have general implications for ELISA measurements in leishmaniasis. ELISA investigations in areas endemic for leishmaniasis might benefit from individual-specific control wells for each serum sample. This approach might also be applicable to other geographical areas or patient groups with high incidence of inflammatory and infectious diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. False-positive F-18 FDG uptake in PET/CT studies in pediatric patients with abdominal Burkitt's lymphoma.

    Science.gov (United States)

    Riad, Raef; Omar, Walid; Sidhom, Iman; Zamzam, Manal; Zaky, Iman; Hafez, Magdy; Abdel-Dayem, Hussein M

    2010-03-01

    In pediatric patients with abdominal Burkitt's lymphoma, the involvement of the gastrointestinal tract and abdominal lymph nodes are the main presenting feature of the disease. Chemotherapy is the main treatment modality and could be preceded by surgical excision of the abdominal masses. To achieve cure or long-term disease-free survival a balance has to be struck between aggressive chemotherapy and the probability of tumor necrosis secondary to treatment complicated by acute infections, perforation or intestinal bleeding. F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) has been recommended over conventional imaging modalities for the follow-up of these patients and for monitoring treatment response. As the incidences of postchemotherapy complications are high, the positive predictive value of PET/CT studies in these patients is very low and the false-positive rate is high from acute infections and tumor necrosis. Accordingly, histopathological confirmation of positive lesions on F-18 FDG-PET/CT studies is essential. This is especially important as post-therapy complications might present with nonspecific and nonurgent symptoms. At the same time initiating a second course of salvage chemotherapy is risky. Retrospectively reviewed F-18 FDG-PET/CT studies for 28 pediatric patients with abdominal Burkitt's lymphoma and diffuse large B-cell lymphoma after their treatment with chemotherapy or surgery. Four positive studies were found. All had pathological verification and were because of acute inflammation and tumor necrosis and there was no evidence of viable tumor cells. One patient had multiple recurrent lesions in the abdomen after the initial surgical excision and before starting chemotherapy. The incidence of acute complications in this series is 10.7%. This study confirms the high incidence of tumor necrosis and inflammation after chemotherapy for the abdominal Burkitt's lymphoma and consequently, the incidence of true-positive

  18. 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

  19. Experimental Null Method to Guide the Development of Technical Procedures and to Control False-Positive Discovery in Quantitative Proteomics.

    Science.gov (United States)

    Shen, Xiaomeng; Hu, Qiang; Li, Jun; Wang, Jianmin; Qu, Jun

    2015-10-02

    Comprehensive and accurate evaluation of data quality and false-positive biomarker discovery is critical to direct the method development/optimization for quantitative proteomics, which nonetheless remains challenging largely due to the high complexity and unique features of proteomic data. Here we describe an experimental null (EN) method to address this need. Because the method experimentally measures the null distribution (either technical or biological replicates) using the same proteomic samples, the same procedures and the same batch as the case-vs-contol experiment, it correctly reflects the collective effects of technical variability (e.g., variation/bias in sample preparation, LC-MS analysis, and data processing) and project-specific features (e.g., characteristics of the proteome and biological variation) on the performances of quantitative analysis. To show a proof of concept, we employed the EN method to assess the quantitative accuracy and precision and the ability to quantify subtle ratio changes between groups using different experimental and data-processing approaches and in various cellular and tissue proteomes. It was found that choices of quantitative features, sample size, experimental design, data-processing strategies, and quality of chromatographic separation can profoundly affect quantitative precision and accuracy of label-free quantification. The EN method was also demonstrated as a practical tool to determine the optimal experimental parameters and rational ratio cutoff for reliable protein quantification in specific proteomic experiments, for example, to identify the necessary number of technical/biological replicates per group that affords sufficient power for discovery. Furthermore, we assessed the ability of EN method to estimate levels of false-positives in the discovery of altered proteins, using two concocted sample sets mimicking proteomic profiling using technical and biological replicates, respectively, where the true-positives

  20. Can elevated lactate and LDH produce a false positive enzymatic ethanol result in live patients presenting to the emergency department?

    Science.gov (United States)

    Nacca, Nicholas; Hodgman, Michael J; Lao, Kirselle; Elkins, Matthew; Holland, Michael G

    2017-08-16

    There have been allegations in the courtroom that elevated serum lactic acid in trauma victims can yield a falsely elevated serum ethanol assay. Most hospitals utilize an indirect method of ethanol measurement where a serum sample is added to a mix of alcohol dehydrogenase and oxidized nicotinamide adenine dinucleotide (NAD+). This allows any ethanol in the patient's serum to be metabolized to acetaldehyde, and in the process results in the reduction of NAD + to NADH. NADH is then measured using spectrophotometry. The courtroom allegation stems from the concept that oxidation of lactate to pyruvate by lactate dehydrogenase (LDH) results in the same molar-for-molar reduction of NAD + to NADH, and could therefore theoretically cause patients with elevated lactate and LDH to have a falsely elevated ethanol concentration. Patients with elevated lactic acid and LDH concentrations who presented to a university hospital from 20 April 2015 to 13 December 2015 were identified to provide possible test specimens. If a sufficient amount of serum was available, the sample was used to re-run the lactate and LDH concentration simultaneously with an enzymatic ethanol assay. Any samples that had elevated lactic acid and LDH concentrations on this retesting, and also yielded a positive ethanol concentration, were sent for confirmatory gas chromatography testing of ethanol concentrations. A control group of 20 samples with normal lactate and LDH were included. A total of 37 samples were included in the final analysis. Only 4 patients had an elevated enzymatic ethanol concentration, and all 4 also had a measurable GC ethanol concentration. The lactate in this dataset ranged from 2.4 to 24.2 mmol/L, with a mean of 6.53 mmol/L (normal value 0.5-2.2). The LDH ranged from 242 to 8838 U/L with a mean of 1695 U/L (normal value 122-225 U/L). Twenty control samples were run on patients with normal lactate and LDH, none of which yielded a positive enzymatic ethanol result

  1. A semi-parametric censoring bias model for estimating the cumulative risk of a false-positive screening test under dependent censoring

    OpenAIRE

    Hubbard, Rebecca A.; Miglioretti, Diana L.

    2013-01-01

    False-positive test results are among the most common harms of screening tests and may lead to more invasive and expensive diagnostic testing procedures. Estimating the cumulative risk of a false-positive screening test result after repeat screening rounds is therefore important for evaluating potential screening regimens. Existing estimators of the cumulative false-positive risk are limited by strong assumptions about censoring mechanisms and parametric assumptions about variation in risk ac...

  2. Unusual False-Positive Mesenteric Lymph Nodes Detected by PET/CT in a Metastatic Survey of Lung Cancer

    Directory of Open Access Journals (Sweden)

    Hirohiko Kamiyama

    2016-06-01

    Full Text Available Positron emission tomography/computed tomography (PET/CT is a credible diagnostic modality for detecting primary and metastatic malignancy. PET/CT sometimes shows false positives and negatives, which make clinical diagnosis difficult. A 42-year-old man who had undergone right upper lobectomy for lung cancer 1 year previously had PET/CT for a metastatic survey of the lung. The lung cancer was stage IB (pT2N0M0 bronchioloalveolar carcinoma. PET/CT showed massive 18F-fluorodeoxyglucose (FDG uptake in the mesenteric lymph nodes. Because the mesentery is an unusual site of metastasis, the patient was under watchful observation. Another PET/CT after 6 months still showed FDG uptake in the same location, with a slightly increased standard uptake value. A systemic survey was performed, but it did not reveal any malignancies or inflammatory diseases. Eventually, the patient underwent probing laparoscopic surgery. For complete resection of the lymph nodes, laparoscopic ileocecal resection was performed. Histologically, the resected lymph nodes showed reactive lymphadenitis. Glucose transporter 1 immunostainings of the lung cancer and the lymph node were positive and partially positive, respectively. Although PET/CT is a powerful diagnostic modality, clinical interpretation of unusual results is difficult.

  3. 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...... mating a library gene deletion haploid to such a conditional centromere strain, which corresponds to the chromosome carrying the gene deletion, loss of heterozygosity (LOH) at the gene deletion locus can be generated in these otherwise hybrid diploids. The use of hybrid diploid strains permits...... 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...

  4. 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.

  5. False positive hepatitis C antibody test results in left ventricular assist device recipients: increased risk with age and transfusions

    Science.gov (United States)

    Lee, Doreen; Colovai, Adriana; Levy, Dana; Vasovic, Ljiljana; Roach, Keith W.; Shuter, Jonathan; Goldstein, Daniel; D’Alessandro, David; Jorde, Ulrich P.; Muggia, Victoria A.

    2017-01-01

    Left ventricular assist devices (LVADs) have been successfully used in patients with heart failure. However, LVADs may trigger immune activation, leading to higher frequencies of autoantibodies. We describe the clinical, epidemiological, and laboratory characteristics of LVAD recipients with false positive hepatitis C (FPHC) serology among 39 consecutive adult LVAD recipients who bridged to heart transplantation from January 2007 to January 2013 at Montefiore Medical Center. FPHC patients were identified as those with post-LVAD positive hepatitis C ELISA antibody tests and negative confirmatory testing with hepatitis C RNA PCR and/or radioimmunoblot assay. Ten (26%) patients previously seronegative for hepatitis C were found to have FPHC after device placement. Of the 39 patients, 32 had HeartMate II devices. The mean age at LVAD placement was 55 years. FPHC correlated with older age at the time of LVAD implantation and with receipt of packed red blood cell transfusions, but not with gender, fresh frozen plasma transfusions, panel reactive antibodies, globulin fraction, rheumatoid factor, or anticardiolipin antibodies. Clinicians should be aware of this increased risk of FPHC in older LVAD patients and those more heavily transfused in order to avoid unnecessary apprehension and possible delay in transplantation. Further studies should be done to evaluate the possible relationship between transfused blood products and immunomodulation. PMID:28203425

  6. 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.

  7. Predicting radiologists' true and false positive decisions in reading mammograms by using gaze parameters and image-based features

    Science.gov (United States)

    Gandomkar, Ziba; Tay, Kevin; Ryder, Will; Brennan, Patrick C.; Mello-Thoms, Claudia

    2016-03-01

    Radiologists' gaze-related parameters combined with image-based features were utilized to classify suspicious mammographic areas ultimately scored as True Positives (TP) and False Positives (FP). Eight breast radiologists read 120 two-view digital mammograms of which 59 had biopsy proven cancer. Eye tracking data was collected and nearby fixations were clustered together. Suspicious areas on mammograms were independently identified based on thresholding an intensity saliency map followed by automatic segmentation and pruning steps. For each radiologist reported area, radiologist's fixation clusters in the area, as well as neighboring suspicious areas within 2.5° of the center of fixation, were found. A 45-dimensional feature vector containing gaze parameters of the corresponding cluster along with image-based characteristics was constructed. Gaze parameters included total number of fixations in the cluster, dwell time, time to hit the cluster for the first time, maximum number of consecutive fixations, and saccade magnitude of the first fixation in the cluster. Image-based features consisted of intensity, shape, and texture descriptors extracted from the region around the suspicious area, its surrounding tissue, and the entire breast. For each radiologist, a userspecific Support Vector Machine (SVM) model was built to classify the reported areas as TPs or FPs. Leave-one-out cross validation was utilized to avoid over-fitting. A feature selection step was embedded in the SVM training procedure by allowing radial basis function kernels to have 45 scaling factors. The proposed method was compared with the radiologists' performance using the jackknife alternative free-response receiver operating characteristic (JAFROC). The JAFROC figure of merit increased significantly for six radiologists.

  8. False positive dengue NS1 antigen test in a traveller with an acute Zika virus infection imported into Switzerland.

    Science.gov (United States)

    Gyurech, Danielle; Schilling, Julian; Schmidt-Chanasit, Jonas; Cassinotti, Pascal; Kaeppeli, Franz; Dobec, Marinko

    2016-01-01

    We report the first case of an acute Zika virus infection imported into Switzerland by a traveller returning from Canoa Quebrada, Ceará state, in the north-eastern part of Brazil. Due to a false positive dengue virus NS1 antigen test, IgG antibody seroconversion and a suggestive clinical picture,an acute dengue fever was initially considered. However, because of lack of specific IgM-antibodies, stationary IgG antibody titre and a negative dengue virus PCR test result, a dengue virus infection was excluded and a cross-reaction with other, causative flaviviruses was postulated. Based on recent reports of Zika fever cases in the north-eastern parts of Brazil, an acute Zika virus infection was suspected. Because of a lack of commercially available Zika virus diagnostic tests, the case was confirmed in the WHO reference laboratory. As the clinical presentation of Zika virus infection can be confused with dengue fever and chikungunya fever, and because of possible public health implications, all patients returning from affected areas should be additionally tested for Zika virus. This case illustrates the urgent medical need for a broadly available assay capable of differentiating Zika from Dengue infections.

  9. A unified methodology based on sparse field level sets and boosting algorithms for false positives reduction in lung nodules detection.

    Science.gov (United States)

    Saien, Soudeh; Moghaddam, Hamid Abrishami; Fathian, Mohsen

    2017-08-09

    This work aims to develop a unified methodology for the false positives reduction in lung nodules computer-aided detection schemes. The 3D region of each detected nodule candidate is first reconstructed using the sparse field method for accurately segmenting the objects. This technique enhances the level set modeling by restricting the computations to a narrow band near the evolving curve. Then, a set of 2D and 3D relevant features are extracted for each segmented candidate. Subsequently, a hybrid undersampling/boosting algorithm called RUSBoost is applied to analyze the features and discriminate real nodules from non-nodules. The performance of the proposed scheme was evaluated by using 70 CT images, randomly selected from the Lung Image Database Consortium and containing 198 nodules. Applying RUSBoost classifier exhibited a better performance than some commonly used classifiers. It effectively reduced the average number of FPs to only 3.9 per scan based on a fivefold cross-validation. The practical implementation, applicability for different nodule types and adaptability in handling the imbalanced data classification insure the improvement in lung nodules detection by utilizing this new approach.

  10. Microarray analysis of cytoplasmic versus whole cell RNA reveals a considerable number of missed and false positive mRNAs.

    Science.gov (United States)

    Trask, Heidi W; Cowper-Sal-lari, Richard; Sartor, Maureen A; Gui, Jiang; Heath, Catherine V; Renuka, Janhavi; Higgins, Azara-Jane; Andrews, Peter; Korc, Murray; Moore, Jason H; Tomlinson, Craig R

    2009-10-01

    With no known exceptions, every published microarray study to determine differential mRNA levels in eukaryotes used RNA extracted from whole cells. It is assumed that the use of whole cell RNA in microarray gene expression analysis provides a legitimate profile of steady-state mRNA. Standard labeling methods and the prevailing dogma that mRNA resides almost exclusively in the cytoplasm has led to the long-standing belief that the nuclear RNA contribution is negligible. We report that unadulterated cytoplasmic RNA uncovers differentially expressed mRNAs that otherwise would not have been detected when using whole cell RNA and that the inclusion of nuclear RNA has a large impact on whole cell gene expression microarray results by distorting the mRNA profile to the extent that a substantial number of false positives are generated. We conclude that to produce a valid profile of the steady-state mRNA population, the nuclear component must be excluded, and to arrive at a more realistic view of a cell's gene expression profile, the nuclear and cytoplasmic RNA fractions should be analyzed separately.

  11. Cell Shaving and False-Positive Control Strategies Coupled to Novel Statistical Tools to Profile Gram-Positive Bacterial Surface Proteomes.

    Science.gov (United States)

    Solis, Nestor; Cordwell, Stuart J

    2016-01-01

    A powerful start to the discovery and design of novel vaccines, and for better understanding of host-pathogen interactions, is to profile bacterial surfaces using the proteolytic digestion of surface-exposed proteins under mild conditions. This "cell shaving" approach has the benefit of both identifying surface proteins and their surface-exposed epitopes, which are those most likely to interact with host cells and/or the immune system, providing a comprehensive overview of bacterial cell topography. An essential requirement for successful cell shaving is to account for (or minimize) cellular lysis that can occur during the shaving procedure and thus generate data that is biased towards non-surface (e.g., cytoplasmic) proteins. This is further complicated by the presence of "moonlighting" proteins, which are proteins predicted to be intracellular but with validated surface or extracellular functions. Here, we describe an optimized cell shaving protocol for Gram-positive bacteria that uses proteolytic digestion and a "false-positive" control to reduce the number of intracellular contaminants in these datasets. Released surface-exposed peptides are analyzed by liquid chromatography (LC) coupled to high-resolution tandem mass spectrometry (MS/MS). Additionally, the probabilities of proteins being surface exposed can be further calculated by applying novel statistical tools.

  12. Analysis of false positive detection of HCV antibody by ELISA%HCV抗体ELISA检测假阳性分析

    Institute of Scientific and Technical Information of China (English)

    张力; 张文娟

    2014-01-01

    Objective To discuss the false positive problem when the S/CO mean of HCV Ab test by ELISA is between 1 to 3.8. Methods 26 cases whose first S/CO mean(3 times by ELISA) was between 1 to 3.8 and 20 cases of normal healthy people were chosen. Do blood test again from 2 months to 6 months. Results 6 cases among 26 cases of reactive result of first ELISA tested negative in the second experiment.20 normal individuals tested negative twice by ELISA.There is significance difference between two test(P<0.01). Conclusion If detection of HCV Ab by ELISA is reactive,should be regularly reviewed,or do other tests.%目的:探讨HCV抗体ELISA检测1<S/CO均值<3.8时假阳性问题。方法筛选HCV抗体ELISA首次检测1<S/CO(3次均值)<3.8共26例,正常体检人群20例,2~6月之间再次抽血检测。结果26例首次检测ELISA有反应性其中6例再次检测为阴性,最终该6例患者确诊为阴性,20例正常体检人群2次均为阴性。两次检测比较结果有显著性差异(P<0.01)。结论 HCV抗体ELISA检测有反应性时应定期复查或做其它检测。

  13. Fish Immunoglobulins

    Science.gov (United States)

    Mashoof, Sara; Criscitiello, Michael F.

    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 immunoglobulin isotype or taxonomic group and what exemplifies an exception. PMID:27879632

  14. 前交叉韧带损伤MRI诊断假阳性和假阴性分析%Analysis on False Positive and False Negative of MRI in Anterior Cruciate Ligament injury

    Institute of Scientific and Technical Information of China (English)

    李彦娴; 袁曙光; 赵新湘; 侯瑞鸿

    2011-01-01

    目的 探讨MRI对前交叉韧带损伤诊断的假阳性及假阴性,提高MRI诊断水平.方法 回顾性分析68例(72膝)膝关节外伤后临床怀疑前交叉韧带损伤患者的MRI检查结果,并与关节镜检查结果 进行对照分析.结果 本组68例(72膝)膝关节外伤患者中,以关节镜结果 为标准,MRI诊断结果:真阳性数52例,真阴性数13例,假阳性数5例,假阴性数2例.灵敏度、特异度、假阳性率及假阴性率分别为96.3%,72.2%,6.9%,2.8%,诊断正确率90.3%.结论 MRI是诊断前交叉韧带损伤极有价值的无创方法,但存在一定的假阳性和假阴性,需要结合患者临床病史和更细致的MRI分析.%Objective To investigate the false positive and the false negative of anterior cruciate ligament tear at MR imaging , so that to improve MRI diagnosis for anterior cruciate ligament tear. Methods MR imaging results in 68 cases ( 72 knees) suspected with anterior cruciate ligament tear clinically were retrospectively reviewed and compared with that of arthroscopy. Results Of 68 patients (72 knees) ,the results of arthroscopy were taken as gold standard ,MRI diagnostic results of anterior cruciate ligament injury were as follows: true positive in 52 cases, true negative in 13 cases, false positive in 5 cases and false negative in 2 cases. The sensitivity , specificity, false positive rate, false negative rate and accuracy in diagnosing anterior cruciate ligamcnt tear with MR imaging were 96. 3 % , 72. 2% , 6. 9% , 2. 8% , 90. 3 % respectively . Conclusion MRI is a very valuable and non-invasive mcthod for the diagnosis of anterior cruciate ligament injury, but which is still with false positive and false negative , so MR imaging findings is necessary to combine clinical examination,otherwise,more detailcd MRI analysis should be done to give precise diagnosis.

  15. 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 which...

  16. False-positive tests for syphilis associated with human immunodeficiency virus and hepatitis B virus infection among intravenous drug abusers. Valencian Study Group on HIV Epidemiology.

    Science.gov (United States)

    Hernández-Aguado, I; Bolumar, F; Moreno, R; Pardo, F J; Torres, N; Belda, J; Espacio, A

    1998-11-01

    The role of HIV, hepatitis C virus, and hepatitis B virus infections in the production of biological false-positive reactions for syphilis was evaluated in two large samples of intravenous drug abusers and homosexual men attending AIDS prevention centers in Spain. A significantly increased odds ratio (OR) for false-positive tests for syphilis [OR 2.23, 95% confidence intervals (CI) 1.76-2.83] was observed for HIV-seropositive intravenous drug abusers; biological false-positive reactions were also more frequent (OR 1.73, 95% CI 1.30-2.31) among intravenous drug abusers who were hepatitis B virus seropositive but not among those who were hepatitis C virus seropositive (OR 0.90; 95% CI 0.48-1.69). Among homosexuals, the association between HIV and biological false-positive reactions was restricted to subjects who were also intravenous drug abusers, indicating the crucial role of intravenous drug abuse. Only 20.5% of intravenous drug abusers with a previous biological false-positive reaction yielded a false-positive result in their subsequent visit.

  17. False positive circumsporozoite protein ELISA: a challenge for the estimation of the entomological inoculation rate of malaria and for vector incrimination

    Directory of Open Access Journals (Sweden)

    Trung Ho Dinh

    2011-07-01

    Full Text Available Abstract Background The entomological inoculation rate (EIR is an important indicator in estimating malaria transmission and the impact of vector control. To assess the EIR, the enzyme-linked immunosorbent assay (ELISA to detect the circumsporozoite protein (CSP is increasingly used. However, several studies have reported false positive results in this ELISA. The false positive results could lead to an overestimation of the EIR. The aim of present study was to estimate the level of false positivity among different anopheline species in Cambodia and Vietnam and to check for the presence of other parasites that might interact with the anti-CSP monoclonal antibodies. Methods Mosquitoes collected in Cambodia and Vietnam were identified and tested for the presence of sporozoites in head and thorax by using CSP-ELISA. ELISA positive samples were confirmed by a Plasmodium specific PCR. False positive mosquitoes were checked by PCR for the presence of parasites belonging to the Haemosporidia, Trypanosomatidae, Piroplasmida, and Haemogregarines. The heat-stability and the presence of the cross-reacting antigen in the abdomen of the mosquitoes were also checked. Results Specimens (N = 16,160 of seven anopheline species were tested by CSP-ELISA for Plasmodium falciparum and Plasmodium vivax (Pv210 and Pv247. Two new vector species were identified for the region: Anopheles pampanai (P. vivax and Anopheles barbirostris (Plasmodium malariae. In 88% (155/176 of the mosquitoes found positive with the P. falciparum CSP-ELISA, the presence of Plasmodium sporozoites could not be confirmed by PCR. This percentage was much lower (28% or 5/18 for P. vivax CSP-ELISAs. False positive CSP-ELISA results were associated with zoophilic mosquito species. None of the targeted parasites could be detected in these CSP-ELISA false positive mosquitoes. The ELISA reacting antigen of P. falciparum was heat-stable in CSP-ELISA true positive specimens, but not in the false positives

  18. Utility of TL-201 SPECT in clarifying false-positive FDG-PET findings due to osteoradionecrosis in head and neck cancer.

    Science.gov (United States)

    Wang, Chih-Hsiu; Liang, Ji-An; Ding, Hueisch-Jy; Yang, Shih-Neng; Yen, Kuo-Yang; Sun, Shung-Shung; Kao, Chia-Hung

    2010-12-01

    This study aimed to determine whether Tl-201 single photon emission CT (SPECT) is potentially useful in differentiating false-positive fluorodeoxyglucose positron emission tomography (FDG-PET) findings caused by osteoradionecrosis (ORN) from recurrent head and neck cancer after radiotherapy. Five patients were recruited. Dual-phase FDG-PET and dual-phase Tl-201 SPECT were performed for each patient. All 5 patients proved to have ORN without recurrent cancer. By visual interpretation, the results were 4 positive versus 1 negative for PET, and 4 negative versus 1 positive for Tl-201 SPECT. The Tl-201 SPECT clarified 3 of the 4 false-positive PETs to be ORN. Dual-phase semiquantitative studies showed decreased standardized uptake value (SUV) over time in 3 of the 4 false-positive PETs and decreased lesion/background ratio over time in the false-positive Tl-201 SPECT. The Tl-201 SPECT may help clarify suspected false-positive FDG uptake caused by ORN. Dual-phase FDG-PET and dual-phase Tl-201 SPECT may also have some value.

  19. Survey of False-positive Reactivity of Latex Agglutination Test for Kala-azar (Katex) without Urine Sample Boiling Process in Autoimmune Patients.

    Science.gov (United States)

    Ghatee, Mohammad Amin; Kanannejad, Zahra; Sharifi, Iraj; Askari, Asma; Bamorovat, Mehdi

    2017-06-01

    Latex agglutination test for Kala-azar (KAtex) is an easy, inexpensive, and field-applicable antigen detection test. However, the main drawback of this method is the boiling step applied to remove false positivity of the test. This study was conducted to survey false positivity results of latex agglutination test for KAtex without boiling process in urine of some autoimmune patients. Ninety-two urine samples from autoimmune patients including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), scleroderma, autoimmune vasculitis, vitiligo, pemphigus and Wagner cases and 20 urine samples from healthy individuals were collected from Kerman Province in Southeastern Iran in 2010-2011. All urine samples were checked by KAtex after boiling for 5 min false positivity rate of the test was surveyed in different healthy and patients groups while boiling process was removed. Rheumatoid factor (RF) then was checked in sera of all cases to evaluate the relationship between RF and KAtex false positivity. All samples represented negative results with KAtex when boiling was performed (100% specificity). Then, 20% positivity was evident in healthy cases. False-positive reactivity was more prominent observed in patient groups than healthy individuals, except in vitiligo. However, a significant difference was only observed in RA group (Pboiling process removal.

  20. 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…

  1. 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 GC/M

  2. 18FECH PET/CT脑显像在脑占位诊断中的价值分析%Analysis of false positive and false negative of 18FECH PET/CT in brain lesions

    Institute of Scientific and Technical Information of China (English)

    程欣; 崔瑞雪; 党永红; 潘慧; 李方

    2011-01-01

    Objective: Because of the high uptake of [18F]fluoro-2-deoxy-D-glucose{18FDG)in brain, its disadvantage in brain lesion positron emission tomography and computer tomography (PET/CT) imaging. [18F]Flunroethyl-dimethyl-2-hydroxyethylammonium(18FECH)background uptake in brain was low. It could improve the sensitive and specificity of brain lesions diagnosis. We analyzed the false positive and false negative in 18FECH PET imaging in brain lesions with the aim of improving the accuracy of diagnosis with 18FECH PET imaging. Methods: 58 patients with brain lesion were studied using 18FDG PET and 18FECH PET/CT brain imaging. It was considered a positive result that increased tracer uptake relative to the surrounding background radioactivity in 18FECH PET/CT imaging, the maximal standardized uptake value (SUVmax) for lesion and peritumoral regions was measured, and a lesion-to-normal tissue uptake ratio (LNR) was calculated. LNK >2 that was considered a positive result. There were eleven false negative and false negative. The diagnoses of all patients were verified by biopsy or operation under neuronavigation guidance, and pathology including immunohistochemistry. Results: l.Five were false positive (one tuberculous granuloma, one necrosis of cerebral infarction, one pilosity hardenability gliocyte proliferation, one hemorrhage caused by vascular malformation and one demyelination). 2. Six were false negative (one dysembryoplastic neuroepithelial tumor, two grade Ⅱ glioma , one grade Ⅱ oligodendroglioma, one grade Ⅱ oligoastrcytoma and one grade Ⅲ anaplastic oligoastrcytoma). 3. The rate of false positive was 13.2%(5/38), the rate of false negative was 15.8%(6/38), the accuracy of 18FECH PET/CT was 71.1%(27/38). Conclusion: 18FECH PET/CT clearly reveals the location and extent of the tumors and has a role in qualitative diagnosis. Howeve, it also has a certain rate of false positivity and false negativity.%目的:由于大脑皮层对氟代脱氧葡萄糖([18F

  3. Problems of false positive laboratory tests during qualification to the ”Program of severe plaque psoriasis treatment” on the basis of two cases

    Directory of Open Access Journals (Sweden)

    Dorota Jaśkiewicz-Nyckowska

    2015-03-01

    Full Text Available Introduction. Qualification of patients for the therapeutic program of severe plaque psoriasis should be preceded by many tests. Abnormal test results require further evaluation and possibly implementation of treatment. False positive results lead to prolongation of the qualification process and may cause disqualification of the patient. Objective. To draw attention to qualification to a drug program. Case reports . A screening test for Lyme disease performed in a 45-year-old man, during qualification for biological treatment, was positive, but verification by Western blot showed a negative result. It caused significant prolongation of the qualification process. In a 26-year-old patient the QuantiFERON test gave a positive result. It was repeated in another laboratory and a negative result was established. Conclusions . False-positive results may result in disqualification from biological treatment. Exchange of experience between doctors is essential for improving inclusion criteria of patients for biological therapy.

  4. 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.

  5. Contamination in the Kepler Field. Identification of 685 KOIs as False Positives Via Ephemeris Matching Based On Q1-Q12 Data

    CERN Document Server

    Coughlin, Jeffrey L; Bryson, Stephen T; Burke, Christopher J; Caldwell, Douglas A; Christiansen, Jessie L; Haas, Michael R; Howell, Steve B; Jenkins, Jon M; Kolodziejczak, Jeffery J; Mullally, Fergal R; Rowe, Jason F

    2014-01-01

    The Kepler mission has to date found almost 6,000 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. 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 false positives as possible, we perform ephemeris matching among all transiting planet, eclipsing binary, and variable star sources. We find that 685 Kepler Objects of Interest - 12% of all those analyzed - are false positives 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 false positives due to contamination, when performing a first-order correction for observational ...

  6. Reducing the probability of false positive research findings by pre-publication validation – Experience with a large multiple sclerosis database

    Directory of Open Access Journals (Sweden)

    Heinz Moritz

    2008-04-01

    Full Text Available Abstract Background Published false positive research findings are a major problem in the process of scientific discovery. There is a high rate of lack of replication of results in clinical research in general, multiple sclerosis research being no exception. Our aim was to develop and implement a policy that reduces the probability of publishing false positive research findings. We have assessed the utility to work with a pre-publication validation policy after several years of research in the context of a large multiple sclerosis database. Methods The large database of the Sylvia Lawry Centre for Multiple Sclerosis Research was split in two parts: one for hypothesis generation and a validation part for confirmation of selected results. We present case studies from 5 finalized projects that have used the validation policy and results from a simulation study. Results In one project, the "relapse and disability" project as described in section II (example 3, findings could not be confirmed in the validation part of the database. The simulation study showed that the percentage of false positive findings can exceed 20% depending on variable selection. Conclusion We conclude that the validation policy has prevented the publication of at least one research finding that could not be validated in an independent data set (and probably would have been a "true" false-positive finding over the past three years, and has led to improved data analysis, statistical programming, and selection of hypotheses. The advantages outweigh the lost statistical power inherent in the process.

  7. Histologic changes associated with false-negative sentinel lymph nodes after preoperative chemotherapy in patients with confirmed lymph node-positive breast cancer before treatment.

    Science.gov (United States)

    Brown, Alexandra S; Hunt, Kelly K; Shen, Jeannie; Huo, Lei; Babiera, Gildy V; Ross, Merrick I; Meric-Bernstam, Funda; Feig, Barry W; Kuerer, Henry M; Boughey, Judy C; Ching, Christine D; Gilcrease, Michael Z

    2010-06-15

    A wide range of false-negative rates has been reported for sentinel lymph node (SLN) biopsy after preoperative chemotherapy. The purpose of this study was to determine whether histologic findings in negative SLNs after preoperative chemotherapy are helpful in assessing the accuracy of SLN biopsy in patients with confirmed lymph node-positive disease before treatment. Eighty-six patients with confirmed lymph node-positive disease at presentation underwent successful SLN biopsy and axillary dissection after preoperative chemotherapy at a single institution between 1994 and 2007. Available hematoxylin and eosin-stained sections from patients with negative SLNs were reviewed, and associations between histologic findings in the negative SLNs and SLN status (true negative vs false negative) were evaluated. Forty-seven (55%) patients had at least 1 positive SLN, and 39 (45%) patients had negative SLNs. The false-negative rate was 22%, and the negative predictive value was 67%. The negative SLNs from 17 of 34 patients with available slides had focal areas of fibrosis, some with associated foamy parenchymal histiocytes, fat necrosis, or calcification. These histologic findings occurred in 15 (65%) of 23 patients with true-negative SLNs and in only 2 (18%) of 11 patients with false-negative SLNs (P = .03, Fisher exact test, 2-tailed). The lack of these histologic changes had a sensitivity and specificity for identifying a false-negative SLN of 82% and 65%, respectively. Absence of treatment effect in SLNs after chemotherapy in patients with lymph node-positive disease at initial presentation has good sensitivity but low specificity for identifying a false-negative SLN.

  8. Invasive pulmonary mycosis due to Chaetomium globosum with false-positive galactomannan test: a case report and literature review.

    Science.gov (United States)

    Capoor, Malini R; Agarwal, Poojan; Goel, Manoj; Jain, Sarika; Shivaprakash, Mandya Rudramurthy; Honnavar, Prasanna; Gupta, Sunita; Chakrabarti, Arunaloke

    2016-03-01

    In this case, the authors report Chaetomium globosum as a cause of invasive pulmonary infection in a patient with Wegener's granulomatosis. Fungal hyphae (KOH and Calcofluor) were seen on direct microscopy of lung biopsy sample and bronchoalveolar lavage (BAL) sample. C. globosum isolated on culture clinched the diagnosis of invasive pulmonary infection by Chaetomium spp. A positive galactomannan of serum and BAL was repeatedly seen and was utilised for follow-up and as prognostic marker in patient management. The patient was successfully treated with liposomal amphotericin B followed by voriconazole. All the Chaetomium infections reported till date since 1980 are reviewed. Chaetomium spp. with its unique ecology has a hidden clinical potential to cause invasive mould infections.

  9. Incidence of and factors associated with false positives in laboratory diagnosis of norovirus infection by amplification of the RNA-dependent RNA polymerase gene.

    Directory of Open Access Journals (Sweden)

    Fang-Ru Lin

    Full Text Available BACKGROUND: Conventional reverse transcription-polymerase chain reaction (RT-PCR amplification of the RNA-dependent RNA polymerase (RdRp gene remains a used method for the rapid detection of norovirus (NV in clinical laboratories. The incidence of and factors associated with false positives in this assay have not been previously evaluated. METHODS/PRINCIPAL FINDINGS: After an NV outbreak caused by the GII.4 Sydney strain in 2012, we reanalysed 250 stool samples positive for NV by RdRp gene detection. True positives were confirmed in 154 (61.6% samples by successful amplification and sequencing confirmation of the viral protein 1 gene. Of the remaining 96 samples that underwent RT-PCR for the RdRp gene, 34 samples yielded PCR products of the expected length. However, the sequences of the amplicons belonged to the human genome, with 91-97% matched nucleotide sequences, indicating false positives. Multivariate analysis of the clinical features of the patients identified a positive stool culture for bacteria (adjusted odds ratio [aOR] 9.07, 95% adjusted confidence interval [aCI] 2.17-37.92, P = .003 and the use of parenteral antibiotics (aOR 5.55, 95% aCI 1.21-24.73, P = .027 as significant and independent factors associated with false positives. CONCLUSION: Conventional RT-PCR targeting the RdRp gene of NV can lead to false positives in patients with bacterial enterocolitis by incidental amplification of DNA from a human source.

  10. Resolution, target density and labeling effects in colocalization studies - suppression of false positives by nanoscopy and modified algorithms.

    Science.gov (United States)

    Xu, Lei; Rönnlund, Daniel; Aspenström, Pontus; Braun, Laura J; Gad, Annica K B; Widengren, Jerker

    2016-03-01

    Colocalization analyses of fluorescence images are extensively used to quantify molecular interactions in cells. In recent years, fluorescence nanoscopy has approached resolutions close to molecular dimensions. However, the extent to which image resolution influences different colocalization estimates has not been systematically investigated. In this work, we applied simulations and resolution-tunable stimulated emission depletion microscopy to evaluate how the resolution, molecular density and label size of targeted molecules influence estimates of the most commonly used colocalization algorithms (Pearson correlation coefficient, Manders' M1 and M2 coefficients), as well as estimates by the image cross-correlation spectroscopy method. We investigated the practically measureable extents of colocalization for stimulated emission depletion microscopy with positive and negative control samples with an aim to identifying the strengths and weaknesses of nanoscopic techniques for colocalization studies. At a typical optical resolution of a confocal microscope (200-300 nm), our results indicate that the extent of colocalization is typically overestimated by the tested algorithms, especially at high molecular densities. Only minor effects of this kind were observed at higher resolutions (algorithm, used in combination with correlation-based methods like the Pearson coefficient and the image cross-correlation spectroscopy approach, to set intensity thresholds separating background noise from signals.

  11. Feline immunoglobulins.

    Science.gov (United States)

    Schultz, R D; Scott, F W; Duncan, J R; Gillespie, J H

    1974-02-01

    Immunoglobulins (Ig) in feline sera and secretions were identified by immuno-electrophoresis and immunodiffusion with rabbit antisera prepared to feline IgG, IgA, IgM, and whole serum. Adult cat sera, colostral whey, postcolostral sera, tears, and nasal secretions contained IgG, IgA, and IgM. IgG was the only Ig identified in precolostral sera and cerebrospinal fluid. Milk, intestinal contents, pooled allantoic and amniotic fluids, and saliva from adult cats and urine from suckling kittens contained IgG and IgA. Ig were not detected in urine from adult cats. Bile was unique in that IgA and IgM were the predominant Ig.

  12. 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...... an efficient method to pinpoint true positive and known causal mutations, decreasing the need of downstream interpretation of variants to a minimum. The combination of whole exome and RNA sequencing efficiently reduced the number of detected mutations. We show that the inclusion of RNA sequencing...... 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....

  13. 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.

  14. False Teeth

    African Journals Online (AJOL)

    FOMCS2

    More than 80% of the respondents used traditional medicine alone or in combination with modern .... Table 2. Perceived causes of false teeth and millet disease in Bushenyi district ..... “Killer” canine removal and its sequelae in Addis Ababa.

  15. Case report of anti-transcription intermediary factor-1-γ/α antibody-positive dermatomyositis associated with gastric cancer and immunoglobulin G4-positive pulmonary inflammatory pseudotumor.

    Science.gov (United States)

    Ito, Kotaro; Imafuku, Shinichi; Hamaguchi, Yasuhito; Fujimoto, Manabu; Nakayama, Juichiro

    2013-07-01

    Dermatomyositis is a rare connective tissue disease often associated with internal malignancy and interstitial pneumonitis. Serologically, various auto-antibodies (Ab) are associated with dermatomyositis. Anti-transcription intermediary factor-1-γ/α (TIF-1-γ/α) Ab was recently identified as an auto-Ab and was observed mostly in cancer-associated dermatomyositis. IgG4-related disease is a newly described entity characterized by increased serum IgG4 levels and IgG4-positive plasma cell infiltration with fibrosis in organs such as the pancreas and parotid gland. IgG4-related disease also includes inflammatory pseudotumors in various organs. We report herein a 59-year-old Japanese man who had dermatomyositis complicated with a gastric cancer and an IgG4-related pulmonary inflammatory pseudotumor. He manifested typical classical Gottron's papules on the fingers, V-sign erythema on the chest, flagellate erythema on the back, nail fold bleeding and facial erythema. Serum levels of anti-TIF-1-γ/α Ab were positive as assessed by immunoprecipitation assay. He also had bilateral swelling of the parotid gland, and an excised specimen of the lung showed inflammatory pseudotumor with IgG4-positive plasma cells. As far as we know, this case is the first to report the association of IgG4-related disease and TIF-1-γ/α-positive dermatomyositis. Further accumulation of such cases is required to elucidate the mechanism of this association.

  16. Criteria to interpret cancer biomarker increments crossing the recommended cut-off compared in a simulation model focusing on false positive signals and tumour detection time

    DEFF Research Database (Denmark)

    Lund, Flemming; Hyltoft Petersen, Per; Pedersen, Merete Frejstrup;

    2014-01-01

    BACKGROUND: Several criteria have been proposed to interpret increments in serological cancer biomarker concentrations starting from low baseline concentrations crossing the cut-off. None of the criteria have been compared for their ability to signal tumour growth when ≤2% false positive results...... are accepted. METHODS: The cancer biomarker Tissue Polypeptide Antigen was used as an example. Seven criteria to interpret increments in concentrations were investigated by computer simulations. Firstly, for each criterion, we identified a baseline concentration stratified for three levels of biological...... that different types of criteria should be used within different intervals of below cut-off level concentrations if the rate of false positive signals of marker increments should be kept ≤2%....

  17. Neisseria gonorrhoeae False-Positive Result Obtained from a Pharyngeal Swab by Using the Roche cobas 4800 CT/NG Assay in New Zealand in 2012

    OpenAIRE

    Upton, Arlo; Bromhead, Collette; Whiley, David M

    2013-01-01

    The Roche cobas 4800 CT/NG assay is a commonly used commercial system for screening for Neisseria gonorrhoeae infection, and previous studies have shown the method to be highly sensitive and specific for urogenital samples. We present the first confirmed clinical N. gonorrhoeae false-positive result using the cobas 4800 NG assay, obtained from testing a pharyngeal swab sample and caused by cross-reaction with a commensal Neisseria strain.

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

    Science.gov (United States)

    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.

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

    OpenAIRE

    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 organis...

  20. 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.

  1. 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

    A sandwich ELISA for quantification of the endometrial protein PP14 revealed false positive reactions in 81% of male sera (n = 54). The PP14 ELISA was based on two monoclonal antibodies (Mabs) with different epitope specificities--a catcher and a biotinylated indicator. The monoclonal antibodies ...... of human anti-mouse IgG antibodies (HAMA), described to create false positive results, may be due to a crossreacting fraction of the polyclonal circulating antibodies against bovine IgG.......A sandwich ELISA for quantification of the endometrial protein PP14 revealed false positive reactions in 81% of male sera (n = 54). The PP14 ELISA was based on two monoclonal antibodies (Mabs) with different epitope specificities--a catcher and a biotinylated indicator. The monoclonal antibodies...... 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...

  2. When the Single Matters more than the Group (II): Addressing the Problem of High False Positive Rates in Single Case Voxel Based Morphometry Using Non-parametric Statistics.

    Science.gov (United States)

    Scarpazza, Cristina; Nichols, Thomas E; Seramondi, Donato; Maumet, Camille; Sartori, Giuseppe; Mechelli, Andrea

    2016-01-01

    In recent years, an increasing number of studies have used Voxel Based Morphometry (VBM) to compare a single patient with a psychiatric or neurological condition of interest against a group of healthy controls. However, the validity of this approach critically relies on the assumption that the single patient is drawn from a hypothetical population with a normal distribution and variance equal to that of the control group. In a previous investigation, we demonstrated that family-wise false positive error rate (i.e., the proportion of statistical comparisons yielding at least one false positive) in single case VBM are much higher than expected (Scarpazza et al., 2013). Here, we examine whether the use of non-parametric statistics, which does not rely on the assumptions of normal distribution and equal variance, would enable the investigation of single subjects with good control of false positive risk. We empirically estimated false positive rates (FPRs) in single case non-parametric VBM, by performing 400 statistical comparisons between a single disease-free individual and a group of 100 disease-free controls. The impact of smoothing (4, 8, and 12 mm) and type of pre-processing (Modulated, Unmodulated) was also examined, as these factors have been found to influence FPRs in previous investigations using parametric statistics. The 400 statistical comparisons were repeated using two independent, freely available data sets in order to maximize the generalizability of the results. We found that the family-wise error rate was 5% for increases and 3.6% for decreases in one data set; and 5.6% for increases and 6.3% for decreases in the other data set (5% nominal). Further, these results were not dependent on the level of smoothing and modulation. Therefore, the present study provides empirical evidence that single case VBM studies with non-parametric statistics are not susceptible to high false positive rates. The critical implication of this finding is that VBM can be used

  3. Biological false-positive tests comprise a high proportion of Venereal Disease Research Laboratory reactions in an analysis of 300,000 sera.

    Science.gov (United States)

    Geusau, Alexandra; Kittler, Harald; Hein, Ulrike; Dangl-Erlach, Edda; Stingl, Georg; Tschachler, Erwin

    2005-11-01

    This retrospective study on syphilis screening at the sexually transmitted infection (STI) unit of a University Department emphasizes the necessity of a treponemal-specific test as the appropriate screening test. The Venereal Disease Research Laboratory (VDRL) test for syphilis screening may, under certain circumstances, yield positive results in patients not infected with Treponema pallidum, a phenomenon referred to as biological false-positive (BFP) VDRL test. The aim of this study was to determine the frequency of BFP tests in a large sample of sera. In this retrospective study, we analysed the results of parallel VDRL and T. pallidum haemagglutination (TPHA) testing of a total of 514,940 blood samples obtained from patients at the Vienna General Hospital between January 1988 and November 1999. Patients' sera with incomplete data on stage and sex and duplicate sera were excluded, leaving 300,000 sera for analysis. The seroprevalence for syphilis was 1.77% (n = 5320), as determined by a positive TPHA test. It was significantly higher in male than in female patients (2.03% versus 1.58%, PVDRL. With regard to reactivity in VDRL testing, 2799 patients (0.92%) of the study population were positive, of whom 736 (26%) were biological false positive. BFP reactivity was found in 0.24% of all patients and was significantly higher in women than in men (0.27% versus 0.20%, PVDRL at 1:0 and 1:2 dilutions without a positive treponemal test was not reported. The subgroup of HIV-positive patients (n = 1415) revealed a 10-fold higher rate of BFP tests (2.1% versus 0.24), an effect being statistically significant. In a low syphilis prevalence population, BFP reactions comprise a high proportion of all VDRL reactors. Therefore, the use of the VDRL as a screening procedure is challenged.

  4. SERIAL NECK ULTRASOUND IS MORE LIKELY TO IDENTIFY FALSE-POSITIVE ABNORMALITIES THAN CLINICALLY SIGNIFICANT DISEASE IN LOW-RISK PAPILLARY THYROID CANCER PATIENTS.

    Science.gov (United States)

    Yang, Samantha Peiling; Bach, Ariadne M; Tuttle, R Michael; Fish, Stephanie A

    2015-12-01

    American Thyroid Association (ATA) low-risk papillary thyroid cancer (PTC) patients without structural evidence of disease on initial posttreatment evaluation have a low risk of recurrence. Despite this, most patients undergo frequent surveillance neck ultrasound (US). The objective of the study was to evaluate the clinical utility of routine neck US in ATA low-risk PTC patients with no structural evidence of disease after their initial thyroid surgery. We performed a retrospective review of 171 ATA low-risk PTC patients after total thyroidectomy, with or without radioactive iodine (RAI) ablation, who had a neck US without suspicious findings after therapy. The main outcome measure was a comparison of the frequency of finding false-positive US abnormalities and the frequency of identifying structural disease recurrence. Over a median follow-up of 8 years, 171 patients underwent a median of 5 neck US (range 2-17). Structural recurrence with low-volume disease (≤1 cm) was identified in 1.2% (2/171) of patients at a median of 2.8 years (range 1.6-4.1 years) after their initial diagnosis. Recurrence was associated with rising serum thyroglobulin (Tg) level in 1 of the 2 patients and was detected without signs of biochemical recurrence in the other patient. Conversely, false-positive US abnormalities were identified in 67% (114/171) of patients after therapy, leading to additional testing without identifying clinically significant disease. In ATA low-risk patients without structural evidence of disease on initial surveillance evaluation, routine screening US is substantially more likely to identify false-positive results than clinically significant structural disease recurrence.

  5. Evaluation of false-positive results on Tc myocardial scintigraphy in patients with coronary artery bypass grafting including left internal thoracic artery-left anterior descending artery grafting

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Koichi; Shibata, Takahiro [Jikei Univ., Tokyo (Japan). School of Medicine; Imai, Kamon

    2000-11-01

    Stress myocardial scintigraphy in patients who have undergone coronary artery bypass grafting (CABG) frequently shows false-positive results. To investigate the reason for these false-positive results, two different stress tests-adenosine triphosphate (ATP) stress testing and ergometer exercise testing, and Tc-tetrofosmin myocardial scintigraphy were performed with a 1-day stress/rest protocol. The subjects were 6 patients with a history of myocardial infarction (MI) and 14 patients with a history of angina pectoris (AP) who had undergone CABG that included left internal thoracic artery-left anterior descending artery grafting. Graft patency was confirmed with coronary angiography. Short-axis images were reconstructed with single photon emission tomography. The severity of perfusion defects on short-axis images was evaluated quantitatively with a normal database as severity score, and the difference in severity score between stress and rest was defined as fill-in. Fill-in on the ATP stress test was 3.1{+-}7.0 in the AP group and 16.3{+-}13.2 in the MI group (p<0.01). Fill-in on the exercise stress test was 2.7{+-}8.3 in the AP group and 34.8{+-}20.6 in the MI group (p<0.01). In the MI group, fill-in on the exercise stress test was significantly greater than that on the ATP stress test (p<0.05). The exercise time and the amount of exercise stress in patients with MI were significantly greater than those in patients with AP. In conclusion, coronary flow reserve may play a role in false positive-finding on myocardial perfusion scintigraphy in patients who have undergone CABG. (author)

  6. False-positive rifampicin resistance on Xpert® MTB/RIF caused by a silent mutation in the rpoB gene.

    Science.gov (United States)

    Mathys, V; van de Vyvere, M; de Droogh, E; Soetaert, K; Groenen, G

    2014-10-01

    The Xpert® MTB/RIF assay detects the presence of Mycobacterium tuberculosis and its resistance to rifampicin (RMP) directly in sputum samples. Discrepant results were observed in a case of smear-positive pulmonary tuberculosis that was Xpert-resistant but phenotypically susceptible to RMP. Complementary investigations (repeat Xpert, Genotype®MTBDRplus assay and sequencing of the rpoB gene) revealed the presence of a silent mutation in the rpoB gene, leading to the conclusion of a false-positive Xpert result. As misinterpretation of Xpert results may lead to inappropriate treatment, the presence of rpoB mutations should be confirmed by sequencing the rpoB gene.

  7. 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.

  8. The background rate of false positives: Combining simulations of gravitational wave events with an unsupervised algorithm for transient identification in crowded image-subtracted data

    Science.gov (United States)

    Ackley, Kendall; Eikenberry, Stephen; Klimenko, Sergey; LIGO Collaboration

    2016-03-01

    We are now entering the era of multimessenger gravitational wave (GW) astronomy with the completion of the first observing run of Advanced LIGO. Multiwavelength electromagnetic (EM) emission is expected to accompany gravitational radiation from compact object binary mergers, such as those between neutron stars and stellar-mass black holes, where Advanced LIGO is most sensitive to their detection. Attempting to perform EM follow-up over the 10-100s deg2 error regions will be faced with many challenges, including the identification and removal of O (105) false positive transients that appear as a commotion of background events and as image artifacts in crowded image-subtracted fields. We present an update to our automated unsupervised algorithm including how our pipeline uses the existing coherent WaveBurst pipeline in an attempt to develop optimized EM follow-up schema. Our end-to-end pipeline combines simulated GW events with actual observational data from a number of ground-based optical observatories, including PTF, ROTSE, and DECam. Our performance is reported both in terms of the number of coincident false positives as well as the efficiency of recovery.

  9. Quantitative immunoglobulins in adulthood.

    Science.gov (United States)

    Crisp, Howard C; Quinn, James M

    2009-01-01

    Although age-related changes in serum immunoglobulins are well described in childhood, alterations in immunoglobulins in the elderly are less well described and published. This study was designed to better define expected immunoglobulin ranges and differences in adults of differing decades of life. Sera from 404 patients, aged 20-89 years old were analyzed for quantitative immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA). The patients with diagnoses or medications known to affect immunoglobulin levels were identified while blinded to their immunoglobulin levels. A two-factor ANOVA was performed using decade of life and gender on both the entire sample population as well as the subset without any disease or medication expected to alter immunoglobulin levels. A literature review was also performed on all English language articles evaluating quantitative immunoglobulin levels in adults >60 years old. For the entire population, IgM was found to be higher in women when compared with men (p immunoglobulin levels, the differences in IgM with gender and age were maintained (p immunoglobulin levels have higher serum IgA levels and lower serum IgM levels. Women have higher IgM levels than men throughout life. IgG levels are not significantly altered in an older population.

  10. False-positive amphetamine/ecstasy (MDMA/3,4-methylenedioxymethamphetamine) (CEDIA) and ecstasy (MDMA/3,4-methylenedioxymethamphetamine) (DRI) test results with fenofibrate.

    Science.gov (United States)

    Kaplan, Yusuf Cem; Erol, Almla; Karadaş, Barş

    2012-10-01

    This case report describes a false-positive amphetamine/ecstasy [3,4-methylenedioxymethamphetamine (MDMA)] and ecstasy (MDMA) screen after therapeutic use of antihyperlipidemic drug, fenofibrate. A 60-year-old male patient was admitted to inpatient psychiatry unit with the diagnosis of alcohol dependency. He was prescribed diazepam 30 mg/day, thiamine 300 mg/day, and naltrexone 50 mg/day. He had also been using fenofibrate 267 mg/day for 3 years for hyperlipidemia and trazodone 100 mg/day for 5 months for insomnia. On routine, urine drugs-of-abuse screening amphetamine/MDMA (CEDIA) test was positive for 4 different occasions and MDMA (DRI) test was positive on 5 different occasions. Gas chromatography/mass spectrometry confirmation of the first positive 3 samples were negative for amphetamine and MDMA. After discontinuation of fenofibrate, amphetamine/MDMA, and MDMA immunoassay results turned out to be negative. Caution should be given to interpretation of amphetamine/MDMA (CEDIA) and MDMA (DRI) tests in patients taking fenofibrate. Specific confirmation with a suitable method should be used to prevent erroneous interpretations.

  11. On the risk of false positive identification using multiple ion monitoring in qualitative mass spectrometry: large-scale intercomparisons with a comprehensive mass spectral library.

    Science.gov (United States)

    Stein, Stephen E; Heller, David N

    2006-06-01

    Analysts involved in qualitative mass spectrometry have long debated the minimum data requirements for demonstrating that signals from an unknown sample are identical to those from a known compound. Often this process is carried out by comparing a few selected ions acquired by multiple ion monitoring (MIM), with due allowance for expected variability in response. In a few past experiments with electron-ionization mass spectrometry (EI-MS), the number of ions selected and the allowable variability in relative abundance were tested by comparing one spectrum against a library of mass spectra, where library spectra served to represent potential false positive signals in an analysis. We extended these experiments by carrying out large-scale intercomparisons between thousands of spectra and a library of one hundred thousand EI mass spectra. The results were analyzed to gain insights into the identification confidence associated with various numbers of selected ions. A new parameter was investigated for the first time, to take into account that a library spectrum with a different base peak than the search spectrum may still cause a false positive identification. The influence of peak correlation among the specific ions in all the library mass spectra was also studied. Our computations showed that (1) false positive identifications can result from similar compounds, or low-abundance peaks in unrelated compounds if the method calls for detection at very low levels; (2) a MIM method's identification confidence improves in a roughly continuous manner as more ions are monitored, about one order of magnitude for each additional ion selected; (3) full scan spectra still represent the best alternative, if instrument sensitivity is adequate. The use of large scale intercomparisons with a comprehensive library is the only way to provide direct evidence in support of these conclusions, which otherwise depend on the judgment and experience of individual analysts. There are

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

    Energy Technology Data Exchange (ETDEWEB)

    Altinmakas, S. [Maltepe Univ., Istanbul (Turkey) Medical Faculty; Dagdeviren, B.; Turkmen, M.; Gursurer, M.; Say, B.; Tezel, T.; Ersek, B.

    2000-03-01

    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 {mu}g/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

  13. Myeloma, source of false positive of parathyroid scintigraphy with {sup 99m}Tc-MIBI; Le myelome, source de faux-positif de la scintigraphie parathyroidienne au 99mTc-MIBI

    Energy Technology Data Exchange (ETDEWEB)

    Zaabar, L.; Ben Sellem, D.; El Ajmi, W.; Slim, I.; Letaief, B.; Mhiri, A.; Ben Slimene, M.F. [Institut Salah Azaiez, Service de medecine nucleaire, Tunis (Tunisia)

    2010-07-01

    Purpose: Considering a specificity of the MIBI dual-phase parathyroid scintigraphy with {sup 99m}Tc-MIBI presents false positives which number has declined since the systematic implementation of the SPECT. We report a case of a superior mediastinal false-positive. Conclusions: the myeloma represents a potential cause of false-positive of parathyroid scintigraphy with {sup 99m}Tc-MIBI. (N.C.)

  14. 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.

  15. Reply to 'Influence of cosmic ray variability on the monsoon rainfall and temperature': a false-positive in the field of solar-terrestrial research

    CERN Document Server

    Laken, Benjamin A

    2015-01-01

    A litany of research has been published claiming strong solar influences on the Earth's weather and climate. Much of this work includes documented errors and false-positives, yet is still frequently used to substantiate arguments of global warming denial. This manuscript reports on a recent study by Badruddin & Aslam (2014), hereafter BA14, which claimed a highly significant ($p=1.4\\times10^{-5}$) relationship between extremes in the intensity of the Indian monsoon and the cosmic ray flux. They further speculated that the relationship they observed may apply across the entire tropical and sub-tropical belt, and be of global importance. However, their statistical analysis---and consequently their conclusions---were wrong. Specifically, their error resulted from an assumption that their data's underlying distribution was Gaussian. But, as demonstrated in this work, their data closely follow an ergodic chaotic distribution biased towards extreme values. From a probability density function, calculated using a...

  16. Filter-based feature selection and support vector machine for false positive reduction in computer-aided mass detection in mammograms

    Science.gov (United States)

    Nguyen, V. D.; Nguyen, D. T.; Nguyen, T. D.; Phan, V. A.; Truong, Q. D.

    2015-02-01

    In this paper, a method for reducing false positive in computer-aided mass detection in screening mammograms is proposed. A set of 32 features, including First Order Statistics (FOS) features, Gray-Level Occurrence Matrix (GLCM) features, Block Difference Inverse Probability (BDIP) features, and Block Variation of Local Correlation coefficients (BVLC) are extracted from detected Regions-Of-Interest (ROIs). An optimal subset of 8 features is selected from the full feature set by mean of a filter-based Sequential Backward Selection (SBS). Then, Support Vector Machine (SVM) is utilized to classify the ROIs into massive regions or normal regions. The method's performance is evaluated using the area under the Receiver Operating Characteristic (ROC) curve (AUC or AZ). On a dataset consisting about 2700 ROIs detected from mini-MIAS database of mammograms, the proposed method achieves AZ=0.938.

  17. 18 F-FDG avid lesion due to coexistent fibrous dysplasia in a child of embryonal rhabdomyosarcoma: Source of false positive FDG-PET

    Directory of Open Access Journals (Sweden)

    Basu Sandip

    2010-01-01

    Full Text Available With increasing use of 18 F-fluorodeoxyglucose (FDG-positron emission tomography (PET in the current oncological practice, there is a growing body of evidence of false positive scans due to various benign conditions. In this communication we present intensely avid 18 F-FDG uptake in fibrous dysplasia of right tibia in a 12-year-old child suffering from embryonal rhabdomyosarcoma (ERMS that could have been easily mistaken to be a metastatic focus if not carefully correlated. The patient was a case of ERMS (presenting with left cervical mass with intrathoracic extension who was treated successfully with chemotherapy and was referred for FDG-PET to evaluate the disease status. His whole body survey was unremarkable except for an intensely avid FDG uptake (SUV max 8.5 in shaft of right tibia. The scan was extended up to foot in view of the fact that a prior bone scan had shown a focal uptake in the similar location. Efforts were undertaken to elucidate the exact etiopathology of the aforementioned 18 F-FDG uptake because the rest of the whole body survey was unremarkable. A plain radiograph (both anteroposterior and lateral views of the right tibia showed patchy sclerosis involving the middle diaphysis of the right tibia suggesting a fibrous defect. The computed tomography (CT scan of the same region showed cortical thickening and increased density within the medullary cavity in the shaft of the tibia. A histopathological diagnosis was sought for and the lesion was subsequently proven to be fibrous dysplasia by histopathology of the bone piece obtained from the right tibial lesion by J needle biopsy. The present case is a useful addition to the current body of literature of false positive 18 F-FDG-PET study due to a benign skeletal pathology and underscores the importance of high index of suspicion and careful clinicoradiopathologic correlation, whenever one comes across such an unusual PET finding.

  18. False-positive myeloperoxidase binding activity due to DNA/anti-DNA antibody complexes: a source for analytical error in serologic evaluation of anti-neutrophil cytoplasmic autoantibodies.

    Science.gov (United States)

    Jethwa, H S; Nachman, P H; Falk, R J; Jennette, J C

    2000-09-01

    Anti-myeloperoxidase antibodies (anti-MPO) are a major type of anti-neutrophil cytoplasmic antibody (ANCA). While evaluating anti-MPO monoclonal antibodies from SCG/Kj mice, we observed several hybridomas that appeared to react with both MPO and DNA. Sera from some patients with systemic lupus erythematosus (SLE) also react with MPO and DNA. We hypothesized that the MPO binding activity is a false-positive result due to the binding of DNA, contained within the antigen binding site of anti-DNA antibodies, to the cationic MPO. Antibodies from tissue culture supernatants from 'dual reactive' hybridomas were purified under high-salt conditions (3 M NaCl) to remove any antigen bound to antibody. The MPO and DNA binding activity were measured by ELISA. The MPO binding activity was completely abrogated while the DNA binding activity remained. The MPO binding activity was restored, in a dose-dependent manner, by the addition of increasing amount of calf-thymus DNA (CT-DNA) to the purified antibody. Sera from six patients with SLE that reacted with both MPO and DNA were treated with DNase and showed a decrease in MPO binding activity compared with untreated samples. MPO binding activity was observed when CT-DNA was added to sera from SLE patients that initially reacted with DNA but not with MPO. These results suggest that the DNA contained within the antigen binding site of anti-DNA antibodies could bind to the highly cationic MPO used as substrate antigen in immunoassays, resulting in a false-positive test.

  19. 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.

  20. Development of a method that eliminates false-positive results due to nerve growth factor interference in the assessment of fulranumab immunogenicity.

    Science.gov (United States)

    Dai, Sheng; Schantz, Allen; Clements-Egan, Adrienne; Cannon, Michael; Shankar, Gopi

    2014-05-01

    Fulranumab, a human IgG2 monoclonal antibody that neutralizes nerve growth factor (NGF), is currently in development for the treatment of pain. Our initial immunogenicity test method was found to be prone to NGF interference, leading to a high apparent incidence of anti-drug antibody (ADA) in phase 1 studies. The ADA immunoassay comprised a homogeneous bridging electrochemiluminescence (ECL) format with biotin and ruthenium-labeled fulranumab bound together ("bridged") by ADA in test samples for detection. In this assay, NGF produced a false-positive signal due to its ability to bridge fulranumab molecules. Thus, we developed a specificity assay to eliminate the NGF false-positive results. We encountered the challenge of eliminating drug interference as well as drug target interference, and discovered that the acid-dissociation-based pretreatment of samples used for mitigating drug interference dramatically increased drug target interference. Several strategies were investigated to eliminate the NGF interference; yet only one strategy specifically removed NGF and produced true fulranumab-specific ADA results by using competitive inhibition with fulranumab and utilizing an alternative NGF binding antibody to eliminate NGF interference. Using this new method, we confirmed that the high apparent anti-fulranumab antibody incidence (>60%) in clinical study samples was in fact due to fulranumab-bound NGF released during the acid-dissociation step of the ADA testing method. We conclude that our revised method accurately identifies anti-fulranumab antibodies by incorporating steps to eliminate fulranumab and NGF interference. We advise that acid-dissociation pretreatment must not be universally applied to improve ADA assays without investigating its bioanalytical risks versus benefits.

  1. Impact of Lymphoid Follicles and Histiocytes on the False Positive FDG Uptake of Lymph Nodes in Non Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Seong Young; Min, Jung Joon; Song, Ho Chun; Choi, Chan; Na, Kook Joo; Bom, Hee Seung [Chonnam National Univ. Hwasun Hospital, Hwasun (Korea, Republic of)

    2011-09-15

    Although {sup 18F} fluorodeoxyglucose (FDG) PET/CT has improved the accuracy of evaluating lymph node (LN) staging in non small cell lung cancer (NSCLC), false positive results remain a problem. The reason why benign LNs show high FDG uptake is still unclear. The aim of this study was to identify molecular and pathological characteristics of benign LNs showing high FDG uptake. We studied 108 mediastinal LNs of pathologically benign nature obtained from 43 patients with NSCLC who underwent FDG PET/CT and surgery. We measured the following parameters in each LN: maximum standardized uptake value (maxSUV), short diameter, maximum Hounsfield unit (maxHU) value, occupied proportions of lymphoid follicles, histiocytes in extrafollicular space and the degree of glucose transporter 1 (Glut1) expression. We compared the parameters between two LN groups according to maxSUV. There were 74 LNs showing maxSUV{>=}3.0 (group 1) and 34 LNs with maxSUV<3.0 (group 2). The size of LN (p<0.001) and maxHU (p=0.003) in group 1 was higher than that in group 2. Histologically, the occupied proportions of lymphoid follicles (p=0.031) or histiocytes (p=0.004) were higher in group 1. The Glut1 expression of lymphoid follicles (p=0.035) or histiocytes (p=0.005) was also higher in group 1. Lymphoid follicular hyperplasia and histiocyte infiltration associated with Glut1 overexpression are important molecular and pathological mechanisms for false positive FDG uptake in benign mediastinal LNs in patients with NSCLC.

  2. 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.

  3. Positive Correlation between Epstein-Barr Virus Viral Load and Anti-Viral Capsid Immunoglobulin G Titers Determined for Hodgkin's Lymphoma Patients and Their Relatives

    OpenAIRE

    Besson, Caroline; Amiel, Corinne; Le-Pendeven, Catherine; Brice, Pauline; Fermé, Christophe; Carde, Patrice; Hermine, Olivier; Raphael, Martine; Abel, Laurent; Nicolas, Jean-Claude

    2006-01-01

    Markers of Epstein-Barr virus (EBV) infection include measures of specific serological titers and of viral load (VLo) in peripheral blood mononuclear cells. Few studies have investigated the correlation between these two phenotypes. Here, we found that there was no correlation between VLo and either anti-EBV nuclear antigen type 1 or anti-early antigen immunoglobulin G (IgG) titer but that anti-viral capsid antigen (VCA) IgG titer increased with VLo in peripheral blood mononuclear cells in pa...

  4. Using a reference when defining an abnormal MRI reduces false-positive MRI results-a longitudinal study in two cohorts at risk for rheumatoid arthritis.

    Science.gov (United States)

    Boer, Aleid C; Burgers, Leonie E; Mangnus, Lukas; Ten Brinck, Robin M; Nieuwenhuis, Wouter P; van Steenbergen, Hanna W; Reijnierse, Monique; Huizinga, Tom W J; van der Helm van Mil, Annette H M

    2017-10-01

    The use of hand and foot MRI in the diagnostic process of RA has been advocated. Recent studies showed that MRI is helpful in predicting progression from clinically suspect arthralgia (CSA) to clinical arthritis, and from undifferentiated arthritis (UA) to RA. Symptom-free persons can also show inflammation on MRI. This study aimed to evaluate if MRI findings in symptom-free volunteers are relevant when defining a positive MRI. Two hundred and twenty-five CSA patients and two hundred and one UA patients underwent MRI of MCP, wrist and MTP joints at baseline and were followed for 1 year on progression to arthritis and RA, respectively, as reported previously. MRI was considered positive if ⩾ 1 joint showed inflammation (called uncorrected definition), or if ⩾ 1 joint had inflammation that was present in < 5% of persons of the same age category at the same location (called 5% corrected definition). Test characteristics were compared for both definitions. By using MRI data of symptom-free volunteers as reference, specificity of MRI-detected inflammation increased from 22 to 56% in CSA patients, and from 10 to 36% in UA patients. The sensitivity was not affected; it was 88 and 85% in CSA patients and 93 and 93% in UA patients. The accuracy also increased, from 32 to 60% in CSA patients and 22 to 44% in UA patients. The use of a reference population resulted in a substantial reduction of false-positive results, without influencing the sensitivity. Although common for other tests in medicine, this phenomenon is novel for MRI in the early detection of RA.

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

    Science.gov (United States)

    Suzuki, Kenji; Yoshida, Hiroyuki; Näppi, Janne; Dachman, Abraham H

    2006-10-01

    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

  6. Development of a sensitive and false-positive free PMA-qPCR viability assay to quantify VBNC Escherichia coli and evaluate disinfection performance in wastewater effluent.

    Science.gov (United States)

    Kibbee, Richard J; Örmeci, Banu

    2017-01-01

    The detection and quantification of viable Escherichia coli cells in wastewater treatment plant effluent is very important as it is the main disinfection efficacy parameter for assessing its public health risk and environmental impact. The aim of this study was to develop a sensitive and false-positive free propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) assay to quantify the viable but non-culturable (VBNC) E. coli present in secondary wastewater effluent after chlorine disinfection. The qPCR target was the E. coli uidA gene, and native Taq was used to eliminate false positives caused by the presence of contaminant E. coli DNA in recombinant Taq polymerase reagents. Due to issues with qPCR inhibitors in wastewater, this study explored several pre-DNA extraction treatment methods for qPCR inhibitor removal. PMA-qPCR validation was done using salmon testes DNA (Sketa DNA) as an exogenous control added directly to the wastewater samples and amplified using a separate qPCR assay. After disinfection of secondary effluent with 2ppm chlorine at the plant, the mean Log10 CFU reduction in E. coli was 2.85 from a mean CFU of 3.48/10mL compared to 0.21 Log10 CCE mean reduction of the uidA gene from a mean CCE of 3.16/10mL. The VBNC cell concentrations were calculated as 2.32 Log10/10mL by subtracting the colony forming units (CFU) obtained from membrane filtration from the calculated CFU equivalent (CCE) values obtained from PMA-qPCR. These results demonstrate the effective use of a PMA-qPCR method for the quantification of the E. coli uidA gene and indicate there are high numbers (2.01×10(3)CCE/100mL) of VBNC E. coli cells leaving the wastewater treatment plant in the final effluent after chlorine treatment. VBNC bacterial cells are of concern as they have the potential to resuscitate and grow, regain virulence, affect natural microbiome in the discharge sites, and pass on antimicrobial resistant genes to other microorganisms. Copyright © 2016

  7. Prevalent false positives of azoospermia factor a (AZFa) microdeletions caused by single-nucleotide polymorphism rs72609647 in the sY84 screening of male infertility

    Institute of Scientific and Technical Information of China (English)

    Qing Wu; Hui-Juan Shi; Guo-Wu Chen; Tao-Fei Yan; Hui Wang; Yu-Ling Liu; Zheng Li; Shi-Wei Duan; Fei Sun; Yun Feng

    2011-01-01

    Multiplex polymerase chain reaction (PCR) has been widely used to detect Y-chromosome microdeletions,which is one of the major causes of male infertility.Both the European Academy of Andrology (EAA) and the European Molecular Genetics Quality Network (EMQN) have recommended the use of sY84 and sY86 markers for the detection of azoospermia factor a (AZFa) microdeletion during DNA testing for male infertility.In this study,a large-scale analysis of AZF microdeletion in a total of 630 Chinese males,including healthy semen donors (n=200),infertile males with normal sperm count (n=226) and patients with either nonobstructive azoospermia or severe oligozoospermia (n=204),was performed.A series of nine sequence-tagged site (STS) markers from the AZF region of the Y chromosome was used to detect microdeletions.All primers were designed based on the recommendations of the National Center for Biotechnology Information.An unusually high incidence (73/630,11.6%) of sY84-absent but sY86-present genotypes was observed in the AZFa microdeletion screening.Sequencing the sY84-flanking region revealed a total of 73 patients with sY84-absent but sY86-present genotypes have a T-to-G transversion at the fifth base from the 5' end of the reverse sY84 primer.These prevalent false positives,which were not only observed in infertile men,but also observed in donors,resulted from a single-nucleotide polymorphism (SNP) named rs72609647 in the targeting sequence of the reverse sY84 primer.Our study suggests that a pre-screening of existence of rs72609647 polymorphism can prevent the frequent false positive results of AZFa microdeletions detection in the infertile Chinese males.Given the SNP rs72609647 was recently found in a deep sequencing of a Chinese individual,the current EAA and EMQN standards may need to be scrutinized among different populations to avoid the potential genetic variations in the primer binding sequences.

  8. 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.

  9. 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.

  10. Possibility of false-positive detection for sporozoites in mosquitos (Diptera: Culicidae) by nested polymerase chain reaction using Plasmodium yoelii genomic DNA.

    Science.gov (United States)

    Tsuzuki, A; Toma, T; Miyagi, I; Toma, H; Arakawa, T; Sato, Y; Kobayashi, J; Mugissa, M F

    2001-06-01

    Anopheles stephensi Liston and An. saperoi Bohart and Ingram infected with the rodent malaria parasite Plasmodium yoelii nigeriense. They were examined 12 and 19 days after blood feeding for sporozoites in head with anterior thorax (HT) and oocysts in abdomen with posterior thorax (AB) by light microscopy and by the nested polymerase chain reaction (nested PCR-based on the amplification of the sequences of the small subunit ribosomal RNA gene). The detection rate of parasite DNA by nested PCR in HT samples 12 days after blood feeding was similar to that by microscopic method. However, in HT samples 19 days after blood feeding, the rate by the PCR method was higher than that by the microscopic method. The incidence of sporozoites in salivary glands of infected mosquitos for 12 days after blood sucking was examined by the PCR method. Parasite DNA in HT of Aedes albopictus Skuse (a non vector for the rodent malaria) as well as An. stephensi and An. saperoi was detected for up to 4 days after feeding on mouse with the rodent malaria parasites. The results indicate that when the PCR method is used for detection of sporozoites of human malaria in mosquitos collected in the field, there are possibilities of including false-positive data for mosquitos that have just or recently fed on human blood infected with malaria (erythrocytic form).

  11. A Discovery of a Candidate Companion to a Transiting System KOI-94: A Direct Imaging Study for a Possibility of a False Positive

    CERN Document Server

    Takahashi, Yasuhiro H; Hirano, Teruyuki; Kuzuhara, Masayuki; Tamura, Motohide; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Hashimoto, Jun; Sato, Bun'ei; Abe, Lyu; Brandner, Wolfgang; Brandt, Timothy D; Carson, Joseph C; Currie, Thayne; Egner, Sebastian; Feldt, Markus; Goto, Miwa; Grady, Carol A; Guyon, Olivier; Hayano, Yutaka; Hayashi, Masahiko; Hayashi, Saeko S; Henning, Thomas; Hodapp, Klaus W; Ishii, Miki; Iye, Masanori; Janson, Markus; Kandori, Ryo; Knapp, Gillian R; Kwon, Jungmi; Matsuo, Taro; McElwain, Michael W; Miyama, Shoken; Morino, Jun-Ichi; Moro-Martin, Amaya; Nishimura, Tetsuo; Pyo, Tae-Soo; Serabyn, Eugene; Suenaga, Takuya; Suto, Hiroshi; Suzuki, Ryuji; Takami, Michihiro; Takato, Naruhisa; Terada, Hiroshi; Thalmann, Christian; Tomono, Daigo; Turner, Edwin L; Watanabe, Makoto; Wisniewski, John; Yamada, Toru; Takami, Hideki; Usuda, Tomonori

    2013-01-01

    We report a discovery of a companion candidate around one of {\\it Kepler} Objects of Interest (KOIs), KOI-94, and results of our quantitative investigation of the possibility that planetary candidates around KOI-94 are false positives. KOI-94 has a planetary system in which four planetary detections have been reported by {\\it Kepler}, suggesting that this system is intriguing to study the dynamical evolutions of planets. However, while two of those detections (KOI-94.01 and 03) have been made robust by previous observations, the others (KOI-94.02 and 04) are marginal detections, for which future confirmations with various techniques are required. We have conducted high-contrast direct imaging observations with Subaru/HiCIAO in $H$ band and detected a faint object located at a separation of $\\sim0.6''$ from KOI-94. The object has a contrast of $\\sim 1\\times 10^{-3}$ in $H$ band, and corresponds to an M type star on the assumption that the object is at the same distance of KOI-94. Based on our analysis, KOI-94....

  12. Target surveillance of blood culture positive samples and control of false positive%血培养阳性标本的目标性监测与假阳性的控制

    Institute of Scientific and Technical Information of China (English)

    覃凌; 王慕云

    2012-01-01

    OBJECTIVE To provide objective guidelines for the clinical diagnosis and rational application of antibiotics by analyzing the reasons of the false positive of blood culture and exploring the effect on its incidence after taking corresponding countermeasures. METHODS We monitored all the positive blood culture cases to find the causes of the false positive cases from Jan to Jun 2008. and the interventions were adopted in response to the problems since Jul 2008, the follow-up of the blood culture positive cases was performed during the period of Jul 2008 -Dec 2010. RESULTS The conditional pathogens were dominated in the blood cultured positive cases during Jan-Jun 2008, among which coagulase-negative Staphylococcus accounted for 83. 33%, the rate of false positive blood culture was 35. 29%, while descending to 8. 70% from Jul to Dec 2010 after taking the control measures (x2 =9. 172,P = 0. 002). CONCLUSION By applying quality control administration mode in target surveillance of blood culture positive, taking correct intervention measures such as instituting standardized blood culture sampling procedure and emphasizing the relevant knowledge and operation skills of the nurses as well as the intensifying the quality supervision and assessment, we can improve the quality of submission of the blood culture specimens, reduce the rate of false positive and ensure the accuracy of the examination results.%目的 分析医院血培养假阳性的原因,探讨采取相关措施后对其发生率的影响,为指导临床诊断及合理应用抗菌药物提供客观依据.方法 对2008年1-6月所有血培养阳性的病例进行目标追踪监测,了解假阳性率,分析产生的原因;2008年7月针对问题采取相应的干预措施,持续追踪2008年7月-2010年12月血培养阳性病例.结果 2008年1-6月血培养假阳性病例的病原菌分布以条件致病菌为主,其中凝固酶阴性葡萄球菌占83.33%,血培养假阳性率高达35.29

  13. Positive Correlation between Epstein-Barr Virus Viral Load and Anti-Viral Capsid Immunoglobulin G Titers Determined for Hodgkin's Lymphoma Patients and Their Relatives

    Science.gov (United States)

    Besson, Caroline; Amiel, Corinne; Le-Pendeven, Catherine; Brice, Pauline; Fermé, Christophe; Carde, Patrice; Hermine, Olivier; Raphael, Martine; Abel, Laurent; Nicolas, Jean-Claude

    2006-01-01

    Markers of Epstein-Barr virus (EBV) infection include measures of specific serological titers and of viral load (VLo) in peripheral blood mononuclear cells. Few studies have investigated the correlation between these two phenotypes. Here, we found that there was no correlation between VLo and either anti-EBV nuclear antigen type 1 or anti-early antigen immunoglobulin G (IgG) titer but that anti-viral capsid antigen (VCA) IgG titer increased with VLo in peripheral blood mononuclear cells in patients with Hodgkin's lymphoma (P = 3.10−3). A similar pattern was observed in healthy first-degree relatives (parents and siblings) of patients (P = 6.10−4). Our results indicate that anti-VCA IgG titers and EBV VLo are specifically correlated EBV phenotypes. PMID:16390946

  14. Immunoglobulins and immunoglobulin genes of the horse.

    Science.gov (United States)

    Wagner, Bettina

    2006-01-01

    Antibodies of the horse were studied intensively by many notable immunologists throughout the past century until the early 1970's. After a large gap of interest in horse immunology, additional basic studies on horse immunoglobulin genes performed during the past 10 years have resulted in new insights into the equine humoral immune system. These include the characterization of the immunoglobulin lambda and kappa light chain genes, the immunoglobulin heavy chain constant (IGHC) gene regions, and initial studies regarding the heavy chain variable genes. Horses express predominately lambda light chains and seem to have a relatively restricted germline repertoire of both lambda and kappa chain variable genes. The IGHC region contains eleven constant heavy chain genes, seven of which are gamma heavy chain genes. It is suggested that all seven genes encoding IgG isotypes are expressed and have distinct functions in equine immune responses.

  15. Is it time to rethink how neuropsychological tests are used to diagnose mild forms of HIV-associated neurocognitive disorders? Impact of false-positive rates on prevalence and power.

    Science.gov (United States)

    Meyer, Ana-Claire L; Boscardin, W John; Kwasa, Judith K; Price, Richard W

    2013-01-01

    Between 0 and 48% of normal HIV-uninfected individuals score below threshold neuropsychological test scores for HIV-associated neurocognitive disorders (HAND) or are false positives. There has been little effort to understand the effect of varied interpretations of research criteria for HAND on false-positive frequencies, prevalence and analytic estimates. The proportion of normal individuals scoring below Z score thresholds drawn from research criteria for HAND, or false-positive frequencies, was estimated in a normal Kenyan population and a simulated normal population using varied interpretations of research criteria for HAND. We calculated the impact of false-positive frequencies on prevalence estimates and statistical power. False-positive frequencies of 2-74% were observed for asymptomatic neurocognitive impairment/mild neurocognitive disorder and 0-8% for HIV-associated dementia. False-positive frequencies depended on the definition of an abnormal cognitive domain, Z score thresholds and neuropsychological battery size. Misclassification led to clinically important overestimation of prevalence and dramatic decreases in power. Minimizing false-positive frequencies is critical to decrease bias in prevalence estimates and minimize reductions in power in studies of association, particularly for mild forms of HAND. We recommend changing the Z score threshold to ≤-1.5 for mild impairment, limiting analysis to 3-5 cognitive domains and using the average Z score to define an abnormal domain. © 2013 S. Karger AG, Basel.

  16. Respostas falso-positivas na triagem auditiva neonatal universal: possíveis causas False-positive results in newborn universal hearing screening: possible causes

    Directory of Open Access Journals (Sweden)

    Maria Cristina Silva Simonek

    2011-04-01

    Full Text Available OBJETIVO: avaliar a ocorrência de respostas falso-positivas na Triagem Auditiva dentro de uma maternidade particular, suas possíveis causas e soluções. MÉTODOS: foram avaliados 1.110 recém-nascidos eutróficos entre 6 e 48 horas de vida no berçário, com o analisador de Emissões Otoacústicas Evocadas Transientes (EOATE modelo Echochek da Ilodynamics Ltd. Na ausência de resposta, foi realizada a manipulação do meato acústico externo (Manobra Facilitadora e colhido novo resultado. Os que falharam foram retestados em 15 dias. RESULTADOS: 50,09% dos RN falhou na primeira tentativa. Após a manobra facilitadora, 24,41% continuou falhando, mas demonstraram EOATE presentes no reteste. O tempo médio de internação foi de 42,27 h, sendo 93,42% oriundos de cesareana. Pertenciam a convênios particulares padrão enfermaria 98% e 2% quarto individual. A idade média do grupo que passou foi de 24,14 h (± 10,21 e a do grupo que falhou 19,19 horas (±8,43. Possuíam menos de 24 horas de vida no momento do teste 66,12% dos RN, foi constatado vérnix obliterante em 4.9%. CONLUSÃO: face a alta precoce hospitalar, é necessário que o Fonoaudiólogo realize o teste antes das 48 horas de vida do RN. Desta forma, além das causas biológicas inerentes a faixa etária, detectou-se um problema estrutural de administração hospitalar, que independe da habilidade ou experiência do Fonoaudiólogo. A Manobra Facilitadora é altamente recomendada.PURPOSE: to investigate the rate of false positive responses in a hospital - based newborn hearing screening program (NHS, their possible causes and solutions. METHODS: during the period we evaluated 1,110 regular nursery newborns, age 6 to 48 hours with Transient Evoked Otoacoustic Emissions (TEOAEs, Echocheck, Ilodynamics Ltd model., at the nurseries, before discharge. In case of absence of response, the ear canal was manipulated. Infants that failed the screening were retested fifteen days after birth

  17. What are the Best Ways to Reduce the False positive Rate of 18F FDG PET/CT in Patients with Breast Cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Evangelista, Laura; Baretta, Zora; Vinante, Lorenzo; Sotti, Guido [Istituto Oncologico Veneto, Padova (Italy)

    2011-03-15

    Dear Editor, We were interested to read the recent article by Park et al that described the interpretation of physiologic and benign sites of {sup 18F} fluorodeoxyglucose (18F FDG) uptake on positron emission tomography/computed tomography (PET/CT) imaging og patients with breast cancer. The central messages were: (1) to know and (2) to discriminate the main sites of FDG avidity, avoiding a misinterpretation and thus reducing the false positive rate. Some considerations referring to the report can be made. The authors declared that several normal and altered physiologic foci and various benign lesions demonstrated significant FDG uptake in patients with breast cancer and the accurate interpretation of these findings can be challenging for clinicians; they concluded that {sup t}o avoid misinterpretations, we suggest that careful attention to these normal or altered physiological FDG uptake patterns and hypermetabolic benign disease is required for more accurate image interpretation for the correct staging and detection of disease recurrence in patients with breast cancer.{sup I}n our Department, in cases of indeterminate or inconclusive PET/CT exams, we try to conclude for pathological or physiological uptake on the basis of abnormal/normal correspondence of CT findings, considering the natural history of disease (i.e. loco regional lymph node or others) and using specific protocols (i.e. dual time PET/CT). As reported in the literature, metabolic abnormalities detected on PET images can be precisely localised anatomically by hardware fusion with the CT images obtained in the same sitting; the CT portion of PET/CT, in fact, provides anatomical details and offers an anatomical mapping for FDG distribution. Moreover, an accurate lesion localisation leads to accurate staging, a clear advantage of PET/CT over PET alone in the clinical situation. Some steps could be taken to reduce the false positive rate of PET/CT in breast cancer: 1. Prolonging the time between the

  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. 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

    2017-03-16

    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.

  20. 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.

  1. A very low geno2pheno false positive rate is associated with poor viro-immunological response in drug-naive patients starting a first-line HAART.

    Directory of Open Access Journals (Sweden)

    Daniele Armenia

    Full Text Available 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 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. 21 CFR 866.5510 - Immunoglobulins A, G, M, D, and E immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunoglobulins A, G, M, D, and E immunological... Test Systems § 866.5510 Immunoglobulins A, G, M, D, and E immunological test system. (a) Identification. An immunoglobulins A, G, M, D, and E immunological test system is a device that consists of...

  3. 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...

  4. 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...

  5. 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...

  6. Relapse of pulmonary tuberculosis: a rare cause of false-positive of the scintigraphy with iodine 131; Sequelles de tuberculose pulmonaire: une rare cause de faux-positif de la scintigraphie a l'iode 131

    Energy Technology Data Exchange (ETDEWEB)

    Ungureanu, C.M.; Angoue, O.; Blagosklonov, O.; Boulahdour, H. [Service de medecine nucleaire, CHU Jean-Minjoz, Besancon, (France); Manzoni, P. [service de radiologie, CHU Jean-Minjoz, Besancon, (France)

    2009-05-15

    The whole body scintigraphy with {sup 131}I is used in the follow up of the differentiated thyroid cancer. It is important to know the causes of false positive before decision of treatment by iodine 131. We present the case of a patient with a pulmonary fixation that was a false positive of {sup 131}I, of rare etiology. The after-effects of tuberculosis are able to fix iodine 131 and then to give false positive. scintigraphy. This etiology of false positive is rare and is worthy to be known because the lung is frequently an area of metastases in the thyroid cancer and the incidence of tuberculosis is increasing. (N.C.)

  7. Massive-training support vector regression and Gaussian process for false-positive reduction in computer-aided detection of polyps in CT colonography.

    Science.gov (United States)

    Xu, Jian-Wu; Suzuki, Kenji

    2011-04-01

    A massive-training artificial neural network (MTANN) has been developed for the reduction of false positives (FPs) in computer-aided detection (CADe) of polyps in CT colonography (CTC). A major limitation of the MTANN is the long training time. To address this issue, the authors investigated the feasibility of two state-of-the-art regression models, namely, support vector regression (SVR) and Gaussian process regression (GPR) models, in the massive-training framework and developed massive-training SVR (MTSVR) and massive-training GPR (MTGPR) for the reduction of FPs in CADe of polyps. The authors applied SVR and GPR as volume-processing techniques in the distinction of polyps from FP detections in a CTC CADe scheme. Unlike artificial neural networks (ANNs), both SVR and GPR are memory-based methods that store a part of or the entire training data for testing. Therefore, their training is generally fast and they are able to improve the efficiency of the massive-training methodology. Rooted in a maximum margin property, SVR offers excellent generalization ability and robustness to outliers. On the other hand, GPR approaches nonlinear regression from a Bayesian perspective, which produces both the optimal estimated function and the covariance associated with the estimation. Therefore, both SVR and GPR, as the state-of-the-art nonlinear regression models, are able to offer a performance comparable or potentially superior to that of ANN, with highly efficient training. Both MTSVR and MTGPR were trained directly with voxel values from CTC images. A 3D scoring method based on a 3D Gaussian weighting function was applied to the outputs of MTSVR and MTGPR for distinction between polyps and nonpolyps. To test the performance of the proposed models, the authors compared them to the original MTANN in the distinction between actual polyps and various types of FPs in terms of training time reduction and FP reduction performance. The authors' CTC database consisted of 240 CTC

  8. 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…

  9. Equine immunoglobulins and organization of immunoglobulin genes.

    Science.gov (United States)

    Walther, Stefanie; Rusitzka, Tamara V; Diesterbeck, Ulrike S; Czerny, Claus-Peter

    2015-12-01

    Our understanding of how equine immunoglobulin genes are organized has increased significantly in recent years. For equine heavy chains, 52 IGHV, 40 IGHD, 8 IGHJ and 11 IGHC are present. Seven of these IGHCs are gamma chain genes. Sequence diversity is increasing between fetal, neonatal, foal and adult age. The kappa light chain contains 60 IGKV, 5 IGKJ and 1 IGKC, whereas there are 144 IGLV, 7 IGLJ, and 7 IGLC for the lambda light chain, which is expressed predominantly in horses. Significant transcriptional differences for IGLV and IGLC are identified in different breeds. Allotypic and allelic variants are observed for IGLC1, IGLC5, and IGLC6/7, and two IGLV pseudogenes are also transcribed. During age development, a decrease in IGLVs is noted, although nucleotide diversity and significant differences in gene usage increased. The following paper suggests a standardization of the existing nomenclature of immunoglobulin genes.

  10. 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

  11. Organization of immunoglobulin genes.

    Science.gov (United States)

    Tonegawa, S; Brack, C; Hozumi, N; Pirrotta, V

    1978-01-01

    The nucleotide-sequence determination of a cloned, embryonic Vlambda gene directly demonstrated that V genes are separate from a corresponding C gene in embryonic cells. Analysis by restriction enzymes of total cellular DNA from various sources strongly suggested that the two separate immunoglobulin genes become continuous during differentiation of B lymphocytes. There seems to be a strict correlation between the joining event and activation of the joined genes. Cloning of more immunoglobulin genes from embryo and plasma cells will not only provide direct demonstration of such a gene-joining event but also help in the elucidation of a possible relationship of the event to gene activation mechanisms.

  12. 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

    CERN Document Server

    Wright, Jason T; Mahadevan, Suvrath; Wang, Sharon X; Ford, Eric B; Payne, Matt; Lee, Brian L; Wang, Ji; Crepp, Justin R; Gaudi, B Scott; Eastman, Jason; Pepper, Joshua; Ge, Jian; Fleming, Scott W; Ghezzi, Luan; Gonzalez-Hernandez, Jonay I; Cargile, Phillip; Stassun, Keivan G; Wisniewski, John; Dutra-Ferreira, Leticia; de Mello, Gustavo F Porto; Maia, Marcio A G; da Costa, Luiz Nicolaci; Ogando, Ricardo L C; Santiago, Basilio X; Schneider, Donald P; Hearty, Fred R

    2013-01-01

    We have analyzed new and previously published radial velocity observations of MARVELS-1, known to have an ostensibly substellar companion in a ~6- day orbit. We find significant (~100 m/s) residuals to the best-fit model for the companion, and these residuals are naively consistent with an interior giant planet with a P = 1.965d in a nearly perfect 3:1 period commensuribility (|Pb/Pc - 3| < 10^{-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-al...

  13. 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

    Science.gov (United States)

    Wright, Jason T.; Roy, Arpita; Mahadevan, Suvrath; Wang, Sharon X.; Ford, Eric B.; Payne, Matt; Lee, Brian L.; Wang, Ji; Crepp, Justin R.; Gaudi, B. Scott; Eastman, Jason; Pepper, Joshua; Ge, Jian; Fleming, Scott W.; Ghezzi, Luan; González-Hernández, Jonay I.; Cargile, Phillip; Stassun, Keivan G.; Wisniewski, John; Dutra-Ferreira, Leticia; Porto de Mello, Gustavo F.; Maia, Márcio A. G.; Nicolaci da Costa, Luiz; Ogando, Ricardo L. C.; Santiago, Basilio X.; Schneider, Donald P.; Hearty, Fred R.

    2013-06-01

    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 (|Pb /Pc - 3| 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.

  14. 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

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Jason T.; Roy, Arpita; Mahadevan, Suvrath; Wang, Sharon X.; Fleming, Scott W. [Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Ford, Eric B.; Payne, Matt; Lee, Brian L.; Ge, Jian [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Wang, Ji [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670 (United States); Gaudi, B. Scott; Eastman, Jason [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Pepper, Joshua; Cargile, Phillip; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Ghezzi, Luan [Observatorio Nacional, Rua General Jose Cristino, 77, Rio de Janeiro, RJ 20921-400 (Brazil); Gonzalez-Hernandez, Jonay I. [Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Wisniewski, John [HL Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St, Norman, OK 73019 (United States); Dutra-Ferreira, Leticia, E-mail: jtwright@astro.psu.edu [Laboratorio Interinstitucional de e-Astronomia (LIneA), Rua General Jose Cristino 77, Rio de Janeiro, RJ 20921-400 (Brazil); and others

    2013-06-20

    We have analyzed new and previously published radial velocity (RV) observations of MARVELS-1, known to have an ostensibly substellar companion in a {approx}6 day orbit. We find significant ({approx}100 m s{sup -1}) residuals to the best-fit model for the companion, and these residuals are naievely consistent with an interior giant planet with a P = 1.965 days in a nearly perfect 3:1 period commensurability (|P{sub b} /P{sub c} - 3| < 10{sup -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 {approx}100 m s{sup -1} residuals are an artifact of spectral contamination from a stellar companion contributing {approx}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.

  15. 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...

  16. Clinical Research of Enzyme Linked Immunosorbent Assay for The Detection of Hepatitis B Virus Surface Antigen False Positive%酶联免疫法检测HBsAg假阳性临床研究

    Institute of Scientific and Technical Information of China (English)

    张海军

    2013-01-01

    目的:研究分析酶联免疫法(ELISA)检测乙肝病毒表面抗原(HBsAg)的假阳性情况.方法:对酶联免疫法检测HBsAg结果为阳性的1500例血清标本用金标法验证,并用化学发光仪微粒子捕捉免疫发光法(MEIA)定量检测HBsAg的含量,以确认酶联免疫法检测结果的假阳性.结果:1500例酶联免疫法检测HBsAg阳性的血清标本,其中1479例为真阳性,真阳性率为98.6%(1479/1500);21例为假阳性,假阳性率为1.4%(21/1500).结论:酶联免疫法检测HBsAg有一定的假阳性,临床检测时应高度注意,避免错报误诊.%Objective: To study enzyme linked immunosorbent assay ( ELISA ) in detecting hepatitis B virus surface antigen ( HBsAg ) of the false positive cases. Method: ELISA for detection of HBsAg results for 1500 cases with positive serum samples using the colloidal gold method validation, and using chemical luminous instrument microparticle enzyme lmmunoassay ( MEIA ) for quantitative detection of HBsAg content, to confirm the enzyme-linked immunosorbent assay for detection of false positive results. Result: 1500 cases of enzyme-linked immunosorbent assay for detection of HBsAg positive serum samples, including 1479 cases of true positive, true positive rate was 98. 6% ( 1479/1500 ); 21 were false positive, false positive rate was 1. 4% ( 21/1500 ). Conclusion: Enzyme-linked immunosorbent assay for detection of HBsAg have false positive, clinical test should be highly attention, avoid the error diagnosis.

  17. Application of PDCA cycle management method in reducing false positive rate of neonatal blood culture%PDCA 循环管理法在降低新生儿血培养假阳性率中的应用

    Institute of Scientific and Technical Information of China (English)

    闵凡云; 周传銮

    2013-01-01

    目的:探讨PDCA循环管理法在降低新生儿血培养假阳性率中的应用及临床效果,为指导临床诊断及合理应用抗菌药物提供客观依据。方法:对2010年7~12月新生儿科32例血培养阳性患儿进行目标追踪监测,了解分析假阳性发生原因并采取PDCA循环管理法,比较实施前后新生儿血培养假阳性率。结果:实施前血培养假阳性患儿病原菌分布以条件致病菌为主,实施前后血培养假阳性率比较差异有统计学意义( P<0.01)。结论:将PDCA循环管理法应用于新生儿血培养阳性目标性监测,可提高血培养标本送检质量,降低假阳性率,保证检验结果准确。%Objective:To explore the application of PDCA cycle management method in reducing false positive rate of neonatal blood culture and investigate the clinical effect in order to provide objective basis for guiding clinical diagnosis and reasonable application of anti -biotics.Methods:The target tracking monitoring was conducted to 32 newborns(born from July to December 2010) whose blood culture was positive to understand and analyze the false positive causes ,and the PDCA cycle management method was implemented .The false positive rate of neonatal blood culture was compared before and after the implementation of the PDCA cycle management method .Results:The con-ditionally pathogenic bacteria in the false positive blood culture was the main pathogen in the distribution before the implementation of the method;the difference in the comparison of the false positive rate of blood culture was statistically significant before and after the imple -mentation of the method(P<0.01).Conclusion:The PDCA cycle management method applied to the target tracking monitoring can im-prove the quality of blood culture specimens and reduce the false positive rate so as to ensure accurate test results .

  18. Increased T cell immunoglobulin and mucin domain 3 positively correlate with systemic IL-17 and TNF-α level in the acute phase of ischemic stroke.

    Science.gov (United States)

    Zhao, Di; Hou, Nan; Cui, Min; Liu, Ying; Liang, Xiaohong; Zhuang, Xuewei; Zhang, Yuanyuan; Zhang, Lining; Yin, Deling; Gao, Lifen; Zhang, Yun; Ma, Chunhong

    2011-08-01

    Tim-3 has been linked to several inflammatory diseases by regulation on both adaptive and innate immunities. Here, we assessed the augmented expression of Tim-3 in brain tissue of ischemia-reperfusion mice and PBMCs of ischemic stroke (IS) patients. The augmented expression of Tim-3 significantly correlated with abnormal lipid levels. In vitro studies showed that plasma from ischemic stroke patients induced Tim-3 expression in THP-1 cells. More importantly, our results revealed a significant correlation of Tim-3 expression on CD4(+) T cells with systemic IL-17 in patients with ischemic stroke. Consistently, we also found a positive correlation of Tim-3 expression on CD14(+) monocytes and serum TNF-α in IS patients. Collectively, augmented expression of Tim-3 may play an important role in the pathogenesis of ischemic stroke by regulation of proinflammatory cytokines. Further studies will give us new insights on the pathogenesis of ischemic stroke and potentially provide a new target at the medical therapy.

  19. Immunoglobulins in granular corneal dystrophy Groenouw type I

    DEFF Research Database (Denmark)

    Møller, H U; Bojsen-Møller, M; Schrøder, H D

    1993-01-01

    Three patients with granular corneal dystrophy Groenouw type I underwent corneal grafting, and cryostat sections of the corneal buttons were examined immunohistochemically for immunoglobulins. Positive results were obtained for IgG, Kappa-, and Lambda chains with immunofluorescence technique...

  20. Impact of vegetarian diet on serum immunoglobulin levels in children.

    Science.gov (United States)

    Gorczyca, Daiva; Prescha, Anna; Szeremeta, Karolina

    2013-03-01

    Nutrition plays an important role in immune response. We evaluated the effect of nutrient intake on serum immunoglobulin levels in vegetarian and omnivore children. Serum immunoglobulin levels and iron status were estimated in 22 vegetarian and 18 omnivore children. Seven-day food records were used to assess the diet. There were no significant differences in serum IgA, IgM, and IgG levels between groups of children. Serum immunoglobulin levels were lower in vegetarian children with iron deficiency in comparison with those without iron deficiency. In the vegetarians, IgG level correlated positively with energy, zinc, copper, and vitamin B(6) intake. In the omnivores, these correlations were stronger with IgM level. Despite negligible differences in serum immunoglobulin levels between vegetarian and omnivore children, the impact of several nutrient intakes on IgM and IgG levels differed between groups. Low iron status in vegetarian children can lead to decreased immunoglobulin levels.

  1. [Selective immunoglobulin A deficiency].

    Science.gov (United States)

    Binek, Alicja; Jarosz-Chobot, Przemysława

    2012-01-01

    Immunoglobulin class A is the main protein of the mucosal immune system. Selective immunoglobulin A deficiency (sIgAD) is the most common primary immunodeficiency in Caucasians. sIGAD is strongly associated with the certain major histocompatibility complex region. Most individuals with sIgAD are asymptomatic and identified coincidentally. However, some patients may present with recurrent infections, allergic disorders and autoimmune manifestations. Several autoimmune diseases, such as systemic lupus erythematosus, diabetes mellitus type 1, Graves disease and celiac disease, are associated with an increased prevalence of sIgAD. Screening for sIgAD in coeliac disease is essential. Patients need treatment of associated diseases. It is also known that IgA deficiency may progress into a common variable immunodeficiency (CVID). Pathogenesis and molecular mechanism involved in sIgAD should be elucidated in the future.

  2. False positive research on HPLC determining aflatoxin residues in Chinese herbal pieces%HPLC法测定中药饮片中黄曲霉毒素残留量的假阳性研究

    Institute of Scientific and Technical Information of China (English)

    郝爱鱼; 赵丽元; 刘英慧; 王戈; 金红宇; 毕秀玲; 门启鸣

    2013-01-01

    Objective: To establish an effective method of eliminating false positive results of aflatoxin residue analysis in Chinese herbal pieces by HPLC, and determine which varieties of traditional Chinese medicines (TCM) are easy to be disturbed by false positive, and define the chemical structure of disruptors. Methods: The samples were analyzed by the immunoaffinity column purification coupled with HPLC and post - column fluorescence detection under conditions of photochemical or non — photochemical derivation, and the ratios of peak areas under these two conditions were calculated and compared. Different HPLC conditions were set to analyze aflatoxin residues in the positive samples, and the analysis results were verified by HPLC - MS/MS. Results: Analysis results for samples of 71 varieties (120 batches) of Chinese herbal pieces demonstrated that there were 8 varieties (13 batches) positive, and 2 varieties (3 batches) were proved as false positive among the positive samples,which were consistent with the verification result by HPLC - MS/MS. The false positive varieties accounted for 2. 8% of the total varieties and the false positive samples accounted for 2. 5% of the total samples. The psoralen and isopsoralen were detected as the disruptors to aflatoxin B1. Conclusion: The method of immunoaffinity column purification and HPLC with post column photochemical derivation and fluorescence detection is suitable for analysis of aflatoxin residues in Chinese herbal pieces,which has a lower false positive rate. The false positive result could be excluded by the methods of peak area comparison with or without photochemical derivation and re - measurement with different HPLC conditions.%目的:建立HPLC法检测中药饮片中黄曲霉毒素残留量的假阳性排除方法,确定易产生假阳性的中药品种,确定干扰物质的化学结构.方法:采用免疫亲和柱净化(IAC)-HPLC-柱后光衍生荧光法测定黄曲霉毒素阳性样品在光衍生或不衍生

  3. Immunoglobulin genes of the turtles.

    Science.gov (United States)

    Magadán-Mompó, Susana; Sánchez-Espinel, Christian; Gambón-Deza, Francisco

    2013-03-01

    The availability of reptile genomes for the use of the scientific community is an exceptional opportunity to study the evolution of immunoglobulin genes. The genome of Chrysemys picta bellii and Pelodiscus sinensis is the first one that has been reported for turtles. The scanning for immunoglobulin genes resulted in the presence of a complex locus for the immunoglobulin heavy chain (IGH). This IGH locus in both turtles contains genes for 13 isotypes in C. picta bellii and 17 in P. sinensis. These correspond with one immunoglobulin M, one immunoglobulin D, several immunoglobulins Y (six in C. picta bellii and eight in P. sinensis), and several immunoglobulins that are similar to immunoglobulin D2 (five in C. picta belli and seven in P. sinensis) that was previously described in Eublepharis macularius. It is worthy to note that IGHD2 are placed in an inverted transcriptional orientation and present sequences for two immunoglobulin domains that are similar to bird IgA domains. Furthermore, its phylogenetic analysis allows us to consider about the presence of IGHA gene in a primitive reptile, so we would be dealing with the memory of the gene that originated from the bird IGHA. In summary, we provide a clear picture of the immunoglobulins present in a turtle, whose analysis supports the idea that turtles emerged from the evolutionary line from the differentiation of birds and the presence of the IGHA gene present in a common ancestor.

  4. Competitive binding experiments can reduce the false positive results of affinity-based ultrafiltration-HPLC: A case study for identification of potent xanthine oxidase inhibitors from Perilla frutescens extract.

    Science.gov (United States)

    Wang, Zhiqiang; Kwon, Shin Hwa; Hwang, Seung Hwan; Kang, Young-Hee; Lee, Jae-Yong; Lim, Soon Sung

    2017-03-24

    The purpose of this study was to assess the possibility of using competitive binding experiments with ultrafiltration-HPLC analysis to identify potent xanthine oxidase (XO) inhibitors from the Perilla frutescens extract as an attempt to reduce the number of false positive results. To isolate the enzyme-ligand complex from unbound compounds, the P. frutescens extract was either incubated in the absence of XO, in the presence of XO, or with the active site blocked XO before the ultrafiltration was performed. Allopurinaol was used as the XO active site blocker. The unbound compounds were subjected to HPLC analysis. The degree of total binding (TBD) and degree of specific binding (SBD) of each compound were calculated using the peak areas. TBD represents the binding affinities of compounds from the P. frutescens extract for the XO binding site. SBD represents the XO competitive binding between allopurinol and ligands from the extract samples. Two criteria were applied to select putative targets that could help avoid false positives. These include TBD>30% and SBD>10%. Using that approach, kaempferol-3-O-rutinoside, rosmarinic acid, methyl-rosmarinic acid, apigenin, and 4',5,7-trimethoxyflavone were identified, from total 11 compounds, as potent XO inhibitors. Finally, apigenin, 4',5,7-trimethoxyflavone, and luteolin were XO inhibitors verified through an XO inhibition assay and structural simulation of the complex. These results showed that the newly developed strategy has the advantage that the number of targets identified via ultrafiltration-HPLC can be narrowed from many false positives. However, not all false positives can be eliminated with this approach. Some potent inhibitors might also be excluded with the use of this method. The limitations of this method are also discussed herein. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. 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

    2016-09-01

    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 Ki 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.

  6. 透析患者血清HBsAg假阳性伴HIV可疑一例分析%Analysis of a Case of Serum False-Positive HBsAg and Suspicious HIV Antibody in Dialysis Patient

    Institute of Scientific and Technical Information of China (English)

    吴卫; 许少侠; 黄媛; 郭野; 司永珍; 杨卓; 谢田; 王巧凤; 崔巍

    2012-01-01

    HBsAg和HIV抗体的检测分别在HBV感染和HIV感染的诊疗中具有重要意义.现阶段HBsAg和HIV抗体主要通过血清免疫学方法检测,其中ELISA法检测HBsAg或HIV抗体的假阳性病例时有报道,而全自动化学发光免疫分析仪的假阳性病例较为少见.该文即报道了一例用全自动化学发光免疫分析仪检测透析患者血清HBsAg假阳性伴HIV抗体可疑的病例,并对可能的原因进行了深入探讨.%HBsAg and HIV antibody play important role in the diagnosis and treatment of HBV and HIV infection respectively. At present, HBsAg and HIV antibody are mainly detected by serum immunological techniques. Cases of false-positive HBsAg or HIV antibody detected by ELISA were reported occasionally while false-positive cases by automatic chemilumi-nescence immune analyzers were reported rarely. A case of serum false-positive HBsAg and suspicious HIV antibody detected by automatic chemiluminescence immune analyzers in dialysis patient is reported in t paper and analyzed for the possible reasons.

  7. 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 Ki 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.

  8. How useful are screening instruments for toddlers to predict outcome at age 4? General development, language skills, and symptom severity in children with a false positive screen for autism spectrum disorder.

    Science.gov (United States)

    Dereu, Mieke; Roeyers, Herbert; Raymaekers, Ruth; Meirsschaut, Mieke; Warreyn, Petra

    2012-10-01

    Screening instruments for autism spectrum disorder (ASD) often generate many false positives. It is argued that these children may have other developmental difficulties and are also in need of thorough assessment and early intervention. The current study looked at the predictive validity of positive screens on the Checklist for Early Signs of Developmental Disorders (CESDD) and the Early Screening of Autistic Traits questionnaire (ESAT) at age 2 towards language, cognitive function, and symptom severity at age 4. Children who screened positive on the ESAT scored lower for both language and cognitive functioning at age 4 compared with children who screened negative on the ESAT. Also, the more signs of ASD that were recognized on the CESDD or ESAT, the lower the scores for language and cognitive functioning at age 4. False positive screens could be differentiated from true positive screens on the CESDD only in symptom severity score on the Autism Diagnostic Observation Schedule (ADOS). It seems that early screeners for ASD also detect children with other developmental disorders and that diagnostic instruments such as the ADOS are warranted to differentiate between children with ASD and other developmental problems.

  9. Prognostic significance of the S-phase fraction of light-chain-restricted cytoplasmic immunoglobulin (cIg) positive plasma cells in patients with newly diagnosed multiple myeloma enrolled on Eastern Cooperative Oncology Group treatment trial E9486.

    Science.gov (United States)

    Trendle, M C; Leong, T; Kyle, R A; Katzmann, J A; Oken, M M; Kay, N E; Van Ness, B G; Greipp, P R

    1999-08-01

    The bone marrow plasma cell labeling index (PCLI) as measured by bromodeoxyuridine uptake is a well-established independent prognostic factor for patients with newly diagnosed multiple myeloma, but the test is not easily done in most laboratories. The purpose of this study was to determine if the proliferative activity (% S-phase) as determined by two-color flow cytometry for cytoplasmic immunoglobulin (cIg) light chain and DNA content also had prognostic significance. As part of Eastern Cooperative Oncology Group clinical trial E9486, 500 patients had successful performance of the bone marrow PCLI. Of 349 patients who had flow cIg and DNA content cytometry, 210 had adequate data to reliably calculate S-phase %. Patients with low % S-phase fraction (/=2%), median survivals 4.1 vs. 2.9 years (P = 0.032). Measurement of the S-phase % by flow cytometry gives significant prognostic information in patients with newly diagnosed myeloma. However, in multivariate analysis, S-phase % did not add prognostic information when PCLI was in the model. S-phase % added prognostic information only when all cases with flow measurement of S-phase % were included, and when PCLI was excluded from the model. Discriminating a population of only cIg positive cells proved difficult in patients with a low percentage of bone marrow plasma cells. Methodology to measure S-phase % in patients with a low percent plasma cells is needed before this technique can be used for diagnosis and prognosis in myeloma. Copyright 1999 Wiley-Liss, Inc.

  10. 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.; Fabrycky, Daniel C.; Ford, Eric B.; Gauthier, Thomas N., III; Gilliland, Ronald L.; Holman, Matthew J.; Howell, Steve B.; Isaacson, Howard; Jenkins, Jon M.; Koch, David G.; Latham, David W.; Lissauer, Jack J.; Marcy, Geoffrey W.; Monet, David G.; Prsa, Andrej; Quinn, Samuel N.

    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.

  11. Comparative study of woman false positive rate in exercise treadmill before or after menopause%女性绝经前后运动平板试验假阳性率的对比研究

    Institute of Scientific and Technical Information of China (English)

    赵小鹏; 何大渊; 安光玉; 郑江红; 寇新惠; 胡冬青

    2009-01-01

    Objective To analyse the rate of coincidence to suspected coronary artery disease (CAD) patient between positive exercise treadmill testing (TET) and coronary angiography (CAG) test.Method Two hundred and sixty-eight chest pain patients positive in TET were performed CAG test,coronary stenosis exceed 50% was diagnosed CAD. Results One hundred and seventy-six patients (65.67%) was diagnosed by CAG, 105 male and 71 female in them. Ninety-two (34.33%) patients was negative in CAG test. The false positive rate of TET between post-menopause patients (30.12%, 25/83 ) andmale patients (28.08%, 41/146) was no significant difference(P > 0.05 ); the difference of false positive rate between pro-menopause patients (66.67%, 26/39) and male patients (28.08% ,41/146) was statistical significance (P 0.05).结论 胸痛患者在冠状动脉造影前行运动平板试验筛查,阳性者再行冠状动脉造影检查可大大提高冠状动脉造影检查的阳性率.女性绝经前患者运动平板试验假阳性率较男性患者和女性绝经后患者高.

  12. 影响新生儿听力筛查假阳性的因素分析%The Analysis of Influence Factors of Newborn Hearing Screening False Positive Rate

    Institute of Scientific and Technical Information of China (English)

    林莉

    2015-01-01

    目的:探讨临床上新生儿听力筛查假阳性以及复查率的影响因素。方法:对来本院筛查的4080例新生儿相关资料进行分析,对所有新生儿进行听力筛查,将初筛不通过的436例新生儿作为试验组,设置研究前初筛不通过的436例作为对照组,比较两组复查结果。结果:6组新生儿每组有680例,A组中110例初筛不通过,且81例假阳性;B组95例初筛不通过,57例假阳性;C组67例初筛不通过,40例假阳性;D组78例初筛不通过,62例假阳性;E组49例初筛不通过,24例假阳性;F组37例初筛不通过,18例假阳性;试验组新生儿出生42 d后349例进行复查,复查率为80.1%,高于对照组,两组比较差异有统计学意义(P<0.05)。结论:听力筛查是早期发现、早期干预听力障碍的重要手段,临床上加强宣传教育提高新生儿复查率。%Objective:To investigate the factors of newborn hearing screeningfalse positive and the clinical effect of review rate.Method:The related data analysis of 4080 cases of newborn in our hospital were selected, hearing screening of all newborns, the screening of 436 cases of neonatal fail as the experimental group, set before the study by screening 436 cases as the control group, two groups were compared the results of the review.Result:Six newborns in each group had 680 cases,A group of 110 cases without going through screening, and 81 cases were false-positive; B group of 95 cases without screening,57 cases were false-positive; C group of 67 cases screening were not passed, 40 cases were false-positive; D group of 78 cases without screening, 62 cases were false-positive; E group of 49 patients without screening, 24 cases were false-positive; F group, 37 cases without screening, 18 cases were false-positive.In the experimental group 349 cases for review, the review was 80.1% higher than the control group, the difference was statistically significant (P<0

  13. Assessment of two malaria rapid diagnostic tests in children under five years of age, with follow-up of false-positive pLDH test results, in a hyperendemic falciparum malaria area, Sierra Leone

    Directory of Open Access Journals (Sweden)

    De Smet Martin

    2010-01-01

    Full Text Available Abstract Background Most malaria rapid diagnostic tests (RDTs use HRP2 detection, including Paracheck-Pf®, but their utility is limited by persistent false positivity after treatment. PLDH-based tests become negative more quickly, but sensitivity has been reported below the recommended standard of 90%. A new pLDH test, CareStart™ three-line P.f/PAN-pLDH, claims better sensitivity with continued rapid conversion to negative. The study aims were to 1 compare sensitivity and specificity of CareStart™ to Paracheck-Pf® to diagnose falciparum malaria in children under five years of age, 2 assess how quickly false-positive CareStart™ tests become negative and 3 evaluate ease of use and inter-reader agreement of both tests. Methods Participants were included if they were aged between two and 59 months, presenting to a Médecins Sans Frontières community health centre in eastern Sierra Leone with suspected malaria defined as fever (axillary temperature > 37.5°C and/or history of fever in the previous 72 hours and no signs of severe disease. The same capillary blood was used for the RDTs and the blood slide, the latter used as the gold standard reference. All positive participants were treated with supervised artesunate and amodiaquine treatment for three days. Participants with a persistent false-positive CareStart™, but a negative blood slide on Day 2, were followed with repeated CareStart™ and blood slide tests every seven days until CareStart™ became negative or a maximum of 28 days. Results Sensitivity of CareStart™ was 99.4% (CI 96.8-100.0, 168/169 and of Paracheck-Pf®, 98.8% (95% CI 95.8-99.8, 167/169. Specificity of CareStart™ was 96.0% (CI 91.9-98.4, 167/174 and of Paracheck-Pf®, 74.7% (CI 67.6-81.0, 130/174 (p ® with excellent inter-reader agreement. Conclusions Both RDTs were highly sensitive, met WHO standards for the detection of falciparum malaria monoinfections where parasitaemia was >100 parasites/μl and were easy

  14. Immunoglobulin G4-related disease with recurrent obstructive jaundice

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Chiu

    2016-03-01

    Full Text Available A 51-year-old man was referred to our clinic for recurrent obstructive jaundice and underwent pylorus-preserving pancreaticoduodenectomy for a suspected malignancy. The pathology showed immunoglobulin G4 positive plasma cell infiltrated at the pancreas and the gallbladder. We discuss the cost-effectiveness of serum immunoglobulin G4 level prior to arranging for a pancreaticoduodenectomy, which would reduce the possibility of surgical complications as well as costs.

  15. Intravenous immunoglobulin treatment of children with autism.

    Science.gov (United States)

    Plioplys, A V

    1998-02-01

    Since autism has been associated with immunologic abnormalities suggesting an autoimmune cause of autistic symptoms in a subset of patients, this study was undertaken to investigate whether intravenous immunoglobulin (i.v.Ig) would improve autistic symptoms. Ten autistic children with immunologic abnormalities, demonstrated on blood tests, were enrolled in this study. Their ages ranged from 4 to 17 years, with two girls and eight boys. Eight children (1 female and 7 male) historically had undergone autistic regression. Intravenous immunoglobulin, 200 to 400 mg/kg, was administered every 6 weeks for an intended treatment program of four infusions. In five children, there was no detectable change in behavior during the treatment program. In four children, there was a mild improvement noted in attention span and hyperactivity. In none of these children did the parents feel that the improvement was sufficient to warrant further continuation of the infusions beyond the termination of the program. Only in one child was there a very significant improvement, with almost total amelioration of autistic symptoms over the time period of the four infusions. Once the treatment program was completed, this child gradually deteriorated over a 5-month time period and fully reverted to his previous autistic state. In this treatment program, five children had no response to intravenous immunoglobulin. In the four children who showed mild improvements, those improvements may simply have been due to nonspecific effects of physician intervention and parental expectation (ie, placebo effect). However, in one child there was a very significant amelioration of autistic symptoms. There were no distinguishing historic or laboratory features in this child who improved. Given a positive response rate of only 10% in this study, along with the high economic costs of the immunologic evaluations and the intravenous immunoglobulin treatments, the use of intravenous immunoglobulin to treat autistic

  16. 21 CFR 866.5550 - Immunoglobulin (light chain specific) immunological test system.

    Science.gov (United States)

    2010-04-01

    ... the reagents used to measure by immunochemical techniques both kappa and lambda types of light chain... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunoglobulin (light chain specific... Test Systems § 866.5550 Immunoglobulin (light chain specific) immunological test system....

  17. 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.

    Science.gov (United States)

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

    2016-11-01

    Background Reference change values provide objective tools to assess the significance of a change in two consecutive results for a biomarker from an individual. The reference change value calculation is based on the assumption that within-subject biological variation has random fluctuation around 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 was based on standard deviations according to the assumption of normality, but was soon changed to coefficients of variation (CV) in the formula (reference change value = ± Z ċ 2(½) ċ CV). Z is being dependent on the desired probability of significance, which also defines the percentages of false-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 distributed and ln-normally distributed data. Conclusions The optimal choice of method to calculate reference change value limits requires knowledge of the distribution of data (normal or ln-normal) and, if possible, knowledge of the homeostatic set point.

  18. Frequent screening with serial neck ultrasound is more likely to identify false-positive abnormalities than clinically significant disease in the surveillance of intermediate risk papillary thyroid cancer patients without suspicious findings on follow-up ultrasound evaluation.

    Science.gov (United States)

    Peiling Yang, Samantha; Bach, Ariadne M; Tuttle, R Michael; Fish, Stephanie A

    2015-04-01

    American Thyroid Association (ATA) intermediate-risk thyroid cancer patients who achieve an excellent treatment response demonstrate a low risk of structural disease recurrence. Despite this fact, most patients undergo frequent surveillance neck ultrasound (US) during follow-up. The objective of the study was to evaluate the clinical utility of routine screening neck US in ATA intermediate-risk patients documented to have a nonstimulated thyroglobulin less than 1.0 ng/mL and a neck US without suspicious findings after therapy. Retrospective review of 90 ATA intermediate-risk papillary thyroid carcinoma patients treated with total thyroidectomy and radioactive iodine ablation in a tertiary referral center. A comparison between the frequency of finding false-positive US abnormalities and the frequency of identifying structural disease recurrence in the study cohort was measured. Over a median of 10 years, 90 patients had a median of six US (range 2-16). Structural disease recurrence was identified in 10% (9 of 90) at a median of 6.3 years. Recurrence was associated with other clinical indicators of disease in 5 of the 90 patients (5.6%, 5 of 90) and was detected without other signs of recurrence in four patients (4.8%, 4 of 84). False-positive US abnormalities were identified in 57% (51 of 90), leading to additional testing, which failed to identify clinically significant disease. In ATA intermediate-risk patients who have a nonstimulated thyroglobulin less than 1.0 ng/mL and a neck US without suspicious findings after therapy, frequent US screening during follow-up is more likely to identify false-positive abnormalities than clinically significant structural disease recurrence.

  19. Interpretation of captopril renal scintigraphy: report of a bilateral false positive case; Interpretation de la scintigraphie renale avec prise de captopril: a propos d`un faux positif bilateral

    Energy Technology Data Exchange (ETDEWEB)

    Patrois, F.; Hignette, C.; Froissart, M.; Prigent, A. [Hopital Broussais, 75 - Paris (France)

    1995-12-31

    Captopril renography is a quite sensitive (70-80%) and a very specific (90-95%) test for the diagnosis of renovascular hypertension induced by renal artery stenosis. Contrasting to morphological techniques (arteriography, intravenous digital subtraction angiography, duplex sonography, angio-MRI), captopril renography can predict the cure or improvement of hypertension after revascularization. Therefore captopril renography will discriminate the renal artery stenosis causing renovascular hypertension from incidental stenosis concomitant with essential hypertension. The test conditions and interpretation present some pitfalls we thereby would discuss, providing a case of bilateral false positive result. (authors). 22 refs., 6 figs.

  20. Rapid 2nd-tier test for measurement of 3-OH-propionic and methylmalonic acids on dried blood spots: reducing the false-positive rate for propionylcarnitine during expanded newborn screening by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    la Marca, Giancarlo; Malvagia, Sabrina; Pasquini, Elisabetta; Innocenti, Marzia; Donati, Maria Alice; Zammarchi, Enrico

    2007-07-01

    The expansion of newborn screening programs has increased the number of newborns diagnosed with inborn errors of metabolism in the presymptomatic phase, but it has also increased the number of costly, stress-producing false-positive results. Because propionylcarnitine (C3) is one of the analytes most frequently responsible for false-positive results, we aimed to develop a rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to identify free methylmalonic (MMA) and 3-OH propionic (3OH-PA) acids in blood spots. We studied newborn screening spots from 250 healthy controls; 124 from infants with abnormal C3, of whom only 5 (4%) were truly affected; 124 from infants with altered isolated methylmalonylcarnitine; and 4 from clinically diagnosed patients. Whole blood was eluted from a 3.2-mm dried blood spot by a CH(3)CN/H(2)O 7:3 and 5 mL/L formic. This extract was injected into a LC-MS/MS equipped with pneumatically assisted electrospray without derivatization. Total analysis time was 5 min per sample. The assays were linear up to 3300 nmol/L for both metabolites. Intra- and interassay imprecision data were 3.6%-8% and 3.1%-6%, respectively, for MMA and 5.2%-20% and 3.6%-17% for 3OH-PA. Limit of detection and limit of quantitation were 1.95 and 4.2 micromol/L, respectively, for MMA and 8 and 10 micromol/L for 3OH-PA. The recoveries were 92.9%-106.1%. No deterioration was noted on the columns after 500 chromatographic runs. If the new method had been used as a 2nd-tier test for the 124 samples, only the 5 true positives would have been recalled for additional samples, and the positive predictive value would have been 100%. This method has the potential to markedly reduce false-positive results and the associated costs and anxiety. It may also be suitable for diagnosing and routinely monitoring blood spots for methylmalonic aciduria and propionic acidemia.

  1. False-Positive Results of 68ga-Dotatate and 11c-Cholıne Pet/CT in Patients with Hormone-Resistant Prostate Cancer at Biochemical Recurrence are Related to Inflamed Lesions

    Directory of Open Access Journals (Sweden)

    Omar Alonso

    2015-02-01

    Full Text Available Objective: For an oncological tracer is relevant to know the uptake in inflamed/infected lesions. Thus, in the framework of a prospective trial aiming to compare the clinical value of 68Ga-DOTATATE and 11C-Choline PET/CT in patients with hormoneresistant prostate cancer at biochemical recurrence, we evaluated the false-positive findings of both techniques. Methods: The study group comprised 64 prostate cancer patients with PSA relapse under androgen deprivation therapy, with a median trigger PSA level of 4.25 ng/mL (range: 0.22-291 ng/mL. Within 1-2 weeks, a PET/CT study was performed with 68Ga-DOTATATE and 11C-Choline with an approximately dose of 100 MBq and 400 MBq, respectively, using a 64-slice PET/CT with time-of-flight correction. Correlative imaging, histopathology and/or clinical follow-up were considered as reference standard. Results: Both techniques showed positive local, regional and distant findings in 31 patients. Results were concordant in 57 cases (89%, with discordant findings observed in patients with bone (n=2 and regional lymph nodes lesions (n=5. On a per patient basis, sensitivity, specificity, positive and negative predictive values with their 95% confidence intervals were the same for both techniques: 0.82 (0.65-0.93, 0.90 (0.73-0.98, 0.90 (0.73-0.98 and 0.81 (0.65-0.93, respectively. False-positive lesions (n=5 were found, for both tracers, in 3 patients and were located in the prostate bed (n=1 and regional lymph nodes (n=4, being 3 discordant. In all cases, pathology revealed non-specific inflammatory lesions. Conclusion: This study demonstrates avid 68Ga-DOTATATE and 11C-Choline accumulation in inflammatory tissue, which may limit the specificity of these techniques for the detection of occult metastatic disease.

  2. Hepatitis B vaccination with or without hepatitis B immunoglobulin at birth to babies born of HBsAg-positive mothers prevents overt HBV transmission but may not prevent occult HBV infection in babies: a randomized controlled trial.

    Science.gov (United States)

    Pande, C; Sarin, S K; Patra, S; Kumar, A; Mishra, S; Srivastava, S; Bhutia, K; Gupta, E; Mukhopadhyay, C K; Dutta, A K; Trivedi, S S

    2013-11-01

    Vertical transmission of Hepatitis B virus HBV can result in a state of chronic HBV infection and its complications. HBV vaccination with or without hepatitis B immunoglobulin (HBIG) prevents transmission of overt infection to the babies. However, whether it also prevents occult HBV infection in babies is not known. Consecutive pregnant women of any gestation found to be HBsAg positive were followed till delivery, and their babies were included in the study. Immediately after delivery, babies were randomized to receive either HBIG or placebo in addition to recombinant HBV vaccine (at 0, 6, 10 and 14 weeks). The primary end-point of the study, assessed at 18 weeks of age, was remaining free of any HBV infection (either overt or occult) plus the development of adequate immune response to vaccine. The babies were further followed up for a median of 2 years of age to determine their eventual outcome. Risk factors for HBV transmission and for poor immune response in babies were studied. Of the 283 eligible babies, 259 were included in the trial and randomized to receive either HBIG (n=128) or placebo (n=131) in addition to recombinant HBV vaccine. Of the 222 of 259 (86%) babies who completed 18 weeks of follow-up, only 62/222 (28%) reached primary end-point. Of the remaining, 6/222 (3%) developed overt HBV infection, 142/222 (64%) developed occult HBV infection, and 12/222 (5%) had no HBV infection but had poor immune response. All 6 overt infections occurred in the placebo group (P=0.030), while occult HBV infections were more common in the HBIG group (76/106 [72%] vs. 66/116 [57%]; P=0.025). This may be due to the immune pressure of HBIG. There was no significant difference between the two groups in frequency of babies developing poor immune response or those achieving primary end-point. The final outcome of these babies at 24 months of age was as follows: overt HBV infection 4%, occult HBV infection 42%, no HBV infection but poor immune response 8% and no HBV

  3. 三种方法联合检测避免梅毒诊断的假阳性结果%Combining three ways to avoid the false positive of screening Treponema pallidum

    Institute of Scientific and Technical Information of China (English)

    潘旭萍; 迟军晓

    2012-01-01

      Objective To investigate a method for avoiding the false positive of screening syphilis by Treponema pallidum antibody enzyme linked immunosorbent assay(TP-ELISA) though combining TP-ELISA with toluidine red unheated serum test(TRUST) and Treponema pallidum panicle agglutination test(TPPA). Methods The clinical samples were screened syphilis by TP-ELISA first, then the positive samples were further tested by TRUST and TPPA. Results There were 114 positive samples tested by TP-ELISA. Among them the number of the same result tested by TPPA was 111. The positive coincidence rate was 97.36%. Among the 111 positive samples,27 positive samples tested by TRUST were also positive tested by TPPA. The positive coincidence rate was 100%. There were 94 positive samples tested by TPPA among the remaining 97 negative samples tested by TRUST. The number of negative samples was 3. The mismatch rate was 2.64%. Conclusions The false positive result tested syphilis by TP-ELISA exists objectively. The positive samples from TP-ELISA were tested by TRUST and then were ascertained by TPPA. The positive result from TPPA can be diagnosed that syphilis antibody was positive. The negative result from TPPA can be diagnosed that syphilis antibody was negative.%  目的探讨用梅毒螺旋体抗体酶联免疫吸附试验(TP-ELISA)联合梅毒甲苯胺红不加热血清试验(TRUST)和梅毒螺旋体明胶凝集试验(TPPA)的方法避免TP-ELISA法筛查梅毒抗体的假阳性结果.方法用TP-ELISA法作为临床标本的梅毒筛查实验,对阳性标本进一步作TRUST和TPPA检测.结果 TP-ELlSA法检出114例梅毒阳性标本,TPPA确证阳性111例,阳性符合率为97.36%(111/114);其中27例TRUST阳性,TPPA确证试验均为阳性,阳性符合率为100%;97例TRUST阴性, TPPA确证阳性94例,阴性3例,不符合率为2.64%.结论 TP-ELISA法筛查梅毒存在一定比例的假阳性结果,对TP-ELlSA法测出的阳性标本先做TRUST试验,再用TPPA确证,阳性

  4. Milk immunoglobulins and complement factors.

    Science.gov (United States)

    Korhonen, H; Marnila, P; Gill, H S

    2000-11-01

    The importance of colostrum for the growth and health of newborn offspring is well known. In bovine colostrum, the antibody (immunoglobulin) complement system provides a major antimicrobial effect against a wide range of microbes and confers passive immunity until the calf's own immune system has matured. Bovine serum and lacteal secretions contain three major classes of immunoglobulins: IgG, IgM and IgA. The immunoglobulins are selectively transported from the serum into the mammary gland, as a result of which the first colostrum contains very high concentrations of immunoglobulins (40-200 mg/ml). IgG1 accounts for over 75 % of the immunoglobulins in colostral whey, followed by IgM, IgA and IgG2. All these immunoglobulins decrease within a few days to a total immunoglobulin concentration of 0.7-1.0 mg/ml, with IgG1 representing the major Ig class in milk throughout the lactation period. Together with the antibodies absorbed from colostrum after birth, the complement system plays a crucial role in the passive immunisation of the newborn calf. The occurrence of haemolytic or bactericidal complement activity in bovine colostrum and milk has been demonstrated in several studies. This review deals with the characteristics of bovine Igs and the complement system to be exploited as potential ingredients for health-promoting functional foods.

  5. The interactions of calreticulin with 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...

  6. False Positive FDG PET/CT Resulting from Fibrous Dysplasia of the Bone in the Work-Up of a Patient with Bladder Cancer: Case Report and Review of the Literature.

    Science.gov (United States)

    Aras, Mustafa; Ones, Tunc; Dane, Faysal; Nosheri, Omid; Inanir, Sabahat; Erdil, Tanju Yusuf; Turoglu, Halil Turgut

    2012-12-01

    Fibrous dysplasia of the bone (FDB) is a common, genetic, developmental disorder with a benign course. FDB can be seen anywhere throughout the skeleton. It is usually asymptomatic and found incidentally on imaging studies that are performed for other purposes. Although whole body 18 F-flourodeoxyglucose PET/CT (FDG PET/CT) is widely used in tumor imaging, infections and benign pathologies like FDB may cause false positive results. Herein we report the case of a 48-year-old FDB patient with transitional cell carcinoma of the urinary bladder. Restaging FDG PET/CT showed multiple mild to moderate hypermetabolic bone lesions which were initially misinterpreted as bone metastases. In this case report, we aimed to guide physicians in evaluating bone lesions in cancer patients with FDB in the light of the literature.

  7. Reducing false-positive biopsies: a pilot study to reduce benign biopsy rates for BI-RADS 4A/B assessments through testing risk stratification and new thresholds for intervention.

    Science.gov (United States)

    Flowers, Chris I; O'Donoghue, Cristina; Moore, Dan; Goss, Adeline; Kim, Danny; Kim, June-Ho; Elias, Sjoerd G; Fridland, Julia; Esserman, Laura J

    2013-06-01

    The aim of this study is to evaluate Breast Imaging Reporting and Data Systems (BI-RADS) 4A/B subcategory risk estimates for ductal carcinoma in situ (DCIS) and invasive cancer (IC), determining whether changing the proposed cutoffs to a higher biopsy threshold could safely increase cancer-to-biopsy yields while minimizing false-positive biopsies. A prospective clinical trial was performed to evaluate BI-RADS 4 lesions from women seen in clinic between January 2006 and March 2007. An experienced radiologist prospectively estimated a percent risk-estimate for DCIS and IC. Truth was determined by histopathology or 4-year follow-up negative for malignancy. Risk estimates were used to generate receiver-operating characteristic (ROC) curves. Biopsy rates, cancer-to-biopsy yields, and type of malignancies missed were then calculated across postulated risk thresholds. A total of 124 breast lesions were evaluated from 213 women. An experienced radiologist gave highly accurate risk estimates for IC, DCIS alone, or the combination with an area under ROC curve of 0.91 (95 % CI 0.84-0.99) (p biopsies avoided; cancer-to-biopsy yields of 36, 47, and 46 %; and associated chance of missing an IC of 0, 1, and 2 %, respectively. Expert radiologists estimate risk of IC and DCIS with a high degree of accuracy. Increasing the cut off point for recommending biopsy, substituting with a short-term follow-up protocol with biopsy if any change, may safely reduce the number of false-positive biopsies.

  8. Dextromethorphan reduces false-positive rate in bronchial provocation test with histamine%右美沙芬降低组胺肺功能激发试验假阳性率

    Institute of Scientific and Technical Information of China (English)

    吕智; 郑亚黎; 江兴堂

    2011-01-01

    目的:探讨组胺激发试验过程中咳嗽不良反应与阳性率的关系.方法:选取我院呼吸内科行组胺支气管激发试验患者120例,随机分为两组,试验前10 min分别予氢溴酸右美沙芬口服溶液30 mg与安慰剂口服,以咳嗽量表评价激发试验过程中咳嗽剧烈程度,并记录激发试验测试结果.3d后试验组激发试验阴性患者于试验前10 min口服安慰剂重新行激发试验.结果:试验组重度咳嗽发生率较对照组低;试验组重度咳嗽患者支气管激发试验阳性率亦较对照组下降;试验组激发试验阴性患者予安慰剂重复激发试验,结果仍全部为阴性.结论:氢溴酸右美沙芬可通过减轻咳嗽不良反应减少重度咳嗽的发生率,从而降低组胺肺功能试验假阳性率,且未出现明显假阴性.%Objective: To investigate the relationship between cough side-effect and false-positive rate in bronchial provocation test with histamine. Methods; A total of 120 patients were enrolled and randomly divided into 2 groups. Patients were treated with either oral solution of dextromethorphan hydrobromide or placebo 10 min before bronchial provocation test. The severity of cough was evaluated by cough scales. Results; The incidence rate of grade 3 cough side-effect and the positive rate of patients with grade 3 cough-side effect were lower in dextromethorphan group than in control group. No positive result was found in repeated tests of bronchial provocation 3 days after the first test in patients with negative result of dextromethorphan group. Conclusion; Dextromethorphan hydrobromide can relieve cough side-effect and thereby reduce false-positive rate in bronchial provocation test with histamine.

  9. 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.

  10. 新生儿血培养阳性标本的目标性监测和假阳性控制研究%Objective Monitoring and Research on the Control of False Positive About Neonatal Blood Culture Positive Samples

    Institute of Scientific and Technical Information of China (English)

    周传銮

    2016-01-01

    Objective To explore the causes of false positive in neonatal blood culture and its countermeasures and application value.Methods The positive cases of neonatal blood culture from January 2013 to December 2015 were retrospectively studied, to analyze the main causes of false positives and to timely apply the corresponding measures.Results Conditional pathogenic bacteria belongs to main false positive cases; the false positive rate before intervention is 24.6%, the false positive rate is 6.5% after intervention. The difference has statistical signiifcance (P<0.05). Conclusion In neonatal blood culture positive specimens, the false positive cases is more, which need to strengthen the timely target monitoring, to ensure the accuracy of the test, to provide more accurate and reliable reference information for clinical diagnosis and treatment.%目的:探究新生儿血培养中出现假阳性原因和应对策略及其应用价值。方法回顾性研究2013年1月~2015年12月新生儿血培养阳性病例,分析假阳性出现的主要原因,并及时地应用相应的对策。结果条件致病菌属于主要的假阳性病例的病原菌;干预前的假阳性率是24.6%,干预后的假阳性率是6.5%,差异有统计学意义(P<0.05)。结论在新生儿血培养阳性标本中,假阳性病例较多,需要及时地加强目标性监测,确保检验准确度,为临床诊治提供更加准确可靠的参考信息。

  11. False "highlighting" with Wood's lamp.

    Science.gov (United States)

    Silverberg, Jonathan I; Silverberg, Nanette B

    2014-01-01

    Wood's lamp evaluation is used to diagnose pigmentary disorders. For example, vitiligo typically demonstrates lesional enhancement under Wood's lamp evaluation. Numerous false positive enhancing lesions can be noted in the skin. We describe a 5-year-old Hispanic boy who had painted his face with highlighter, producing enhancing lesions under Wood's lamp. Physicians who use Wood's lamp should be aware that the appearance of markers and highlighter can mimic that of true clinical illnesses.

  12. Immunoglobulin G4-Related Disease Mimicking Asthma

    Directory of Open Access Journals (Sweden)

    Hiroshi Sekiguchi

    2013-01-01

    Full Text Available Immunoglobulin (Ig G4-related disease (also known as ‘IgG4-related sclerosing disease’, ‘IgG4-related systemic disease’ or ‘hyper-IgG4-disease’ is a recently recognized systemic fibroinflammatory disease associated with IgG4-positive plasma cells in tissue lesions. IgG4-related disease was initially described as autoimmune pancreatitis, but it is now known to affect virtually any organ. The authors describe a patient presenting with multi-organ manifestations, including airway inflammation mimicking asthma, pulmonary parenchymal infiltrates, intrathoracic lymphadenopathy, submandibular gland swelling and a kidney mass.

  13. Modeling Kepler transit light curves as false positives: Rejection of blend scenarios for KOI-377, and strong evidence for a super-Earth-size planet in a multiple system

    CERN Document Server

    Torres, Guillermo; Batalha, Natalie M; Borucki, William J; Brown, Timothy M; Bryson, Stephen T; Buchhave, Lars A; Charbonneau, David; Ciardi, David R; Dunham, Edward W; Fabrycky, Daniel C; Ford, Eric B; Gautier, Thomas N; Gilliland, Ronald L; Holman, Matthew J; Howell, Steve B; Isaacson, Howard; Jenkins, Jon M; Koch, David G; Latham, David W; Lissauer, Jack J; Marcy, Geoffrey W; Monet, David G; Prsa, Andrej; Ragozzine, Darin; Rowe, Jason F; Sasselov, Dimitar D

    2010-01-01

    The high-precision 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 the result of an astrophysical false positive, we describe a procedure we refer to as BLENDER to model the photometry not in terms of a planet orbiting a star, but instead as a "blend". 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 the technique to the case of KOI-377, a particularly interesting Kepler 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 1.6-day period that would correspond to a super-Earth with a radius of 1.4 R(Earth), the smallest yet discovered. Using BLENDER together with constraints from high-resolution ima...

  14. Metabolitos del efavirenz como probable causa de falsos-positivos en test inmunológico para benzodiacepinas en orina False-positive immunoassay results for urine benzodiacepines probably caused by efavirenz metabolites

    Directory of Open Access Journals (Sweden)

    Patricia N. Quiroga

    2007-12-01

    Full Text Available En el tratamiento del síndrome de inmunodeficiencia adquirida (SIDA una de las drogas antirretrovirales usadas es el efavirenz (EFV. Existe una asociación entre el consumo de drogas de abuso y la probabilidad de adquirir el SIDA, razón por la cual se solicita su investigación en orina. Como método de screening para detectar el consumo de estas drogas se utilizan habitualmente los ensayos inmunológicos. Una característica especial de estos métodos son las reacciones cruzadas que pueden presentarse con sustancias estructuralmente relacionadas dando origen a resultados falsos positivos. Al analizar 18 muestras de orina de pacientes con SIDA, se observó un 78% de resultados falsos positivos para benzodiacepinas (BZD cuando fueron analizados mediante el ensayo inmunológico Triage® (Ascend Multi Immune Assay. El estudio confirmatorio por cromatografía gaseosa acoplada a espectrometría de masa (GC-MS reveló la ausencia de BZD en todos los casos y el 100% de los resultados falsos positivos observados correspondieron a las muestras de los pacientes tratados con EFV. Con el propósito de dilucidar el origen de esta reacción cruzada fueron aislados el EFV y sus metabolitos de las muestras de orina, mediante extracción en fase sólida (SPE y cromatografía en capa delgada de alta resolución (HPTLC, e identificados por cromatografía gaseosa- espectrometría de masa (GC-MS y GC-MS/MS/MS. Los resultados obtenidos en este estudio indicarían que los metabolitos del EFV (8-OH-EFV y/o 7-OH-EFV y no el EFV podrían ser los responsables de la reacción cruzada observada en el ensayo inmunológico.Efavirenz (EFV is an antiretroviral drug used in the acquired immunodeficiency syndrome (AIDS treatment. Immunoassay techniques have been widely used for abuse drug screening test. The presence of structurally related substances in urine samples can interfere by cross reactions causing false positive results. High percentage of false positive results (78

  15. Baryogenesis in false vacuum

    CERN Document Server

    Hamada, Yuta

    2016-01-01

    The null result in the LHC may indicate that the standard model is not drastically modified up to very high scale 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 the large vacuum expectation value in the early universe, the 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 a second Higgs doublet and a singlet scalar.

  16. False pop out.

    Science.gov (United States)

    Orsten-Hooge, Kimberley D; Portillo, Mary C; Pomerantz, James R

    2015-12-01

    A single, unique target often pops out quickly and efficiently from a field of homogenous distractors in visual search. Pop out has helped shape theories of visual attention and feature integration as well as to identify basic features in human vision. Here we report a new phenomenon, false pop out, wherein one of the homogenous distractors competes with the singleton target to pop out, perhaps by breaking an overall grouping or pattern emerging from the display. We show the effect occurs with more than 1 type of stimulus, and we discuss the implications of such a counterintuitive finding for theories of visual search.

  17. 两例无创产前基因检测假阳性病例的分析%Analysis of two false positive cases from noninvasive prenatal testing

    Institute of Scientific and Technical Information of China (English)

    陈雪娇; 戴美珍; 石卫武; 潘映秋; 章卫国; 章鸯; 吴志强

    2014-01-01

    Objective To track and analyze two false positive cases from non-invasive prenatal testing for potential fetal aneuploidy.Methods The two cases,respectively reported to have XO (+ + +) and T18 (1/20) XO (+),were analyzed with conventional karyotyping,fluorescence in situ hybridization (FISH) and massively parallel genomic sequencing (MPS).Results The first fetus,who was suspected for XO(+ + +),was verified to have super female syndrome (47,XXX/46,XX) due to confined placental mosaicism by karyotyping of amniotic fluid cells,FISH analysis of placenta and massively parallel sequencing (MPS) of fetal tissue.The second fetus,suspected to have trisomy 18 (1/20) XO(+),was verified to have Turner syndrome by karyotyping,FISH and MPS analyses of umbilical cord blood cells.And the karyotype was 45,X[48]/ 46,X,der(X)del(X) (p11.21)del(X) (q13.3)[62].Conclusion Non invasive prenatal testing carries a risk for false positive diagnosis of fetal sex chromosome and trisomy 18.Combined eytogenetic and molecular techniques are required to ensure an accurate diagnosis.%目的 分析2例无创产前基因检测假阳性病例,为患者提供精确的染色体诊断结果.方法 应用传统细胞核型分析、荧光原位杂交技术(fluorescence in situ hybridization,FISH)及大规模并行基因组测序技术(massively parallel sequencing,MPS)对2例无创基因检测分别提示XO(+++)和T18(1/20)XO(+)的胎儿进行检测分析.结果 例1的无创基因检测结果提示为XO(+++),经羊水细胞传统核型分析、胎盘FISH检测及胎儿组织MPS检测后确诊为胎盘特异性嵌合的超雌综合征嵌合体,核型为47,XXX/46,XX.例2的无创产前基因检测结果提示为T18(1/20) XO(+),经脐带血核型分析、MPS、FISH检测后确诊为特纳综合征,核型为45,X[48]/46,X,der(X) del(X) (p11.21)del(X) (q13.3)[62].结论 无创基因检测对于胎儿性染色体及18三体高危存在假阳性,提示在产前诊断中应合理联合应用各种不同的细胞

  18. 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

  19. False color viewing device

    Science.gov (United States)

    Kronberg, J.W.

    1992-10-20

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-07-01

    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.

  1. 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

  2. The interactions of calreticulin with immunoglobulin G and immunoglobulin Y.

    Science.gov (United States)

    Møllegaard, Karen Mai; Duus, Karen; Træholt, Sofie Dietz; Thaysen-Andersen, Morten; Liu, Yan; Palma, Angelina S; Feizi, Ten; Hansen, Paul R; Højrup, Peter; Houen, Gunnar

    2011-07-01

    Calreticulin is a chaperone of the endoplasmic reticulum (ER) assisting proteins in achieving the correctly folded structure. Details of the binding specificity of calreticulin are still a matter of debate. Calreticulin has been described as an oligosaccharide-binding chaperone but data are also 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. Additionally, calreticulin peptide binding was examined with synthetic peptides covering the IgG Cγ2 domain demonstrating interaction with approximately half the peptides. Our results show that the dominant binding activity of calreticulin in vitro is toward the polypeptide moieties of IgG and IgY even in the presence of the monoglucosylated high mannose N-linked oligosaccharide on IgY.

  3. Underpowered samples, false negatives, and unconscious learning

    OpenAIRE

    Vadillo, M. A.; Konstantinidis, E.; Shanks, D.R.

    2016-01-01

    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...

  4. Immunoglobulin K light chain deficiency: A rare, but probably underestimated, humoral immune defect.

    Science.gov (United States)

    Sala, Pierguido; Colatutto, Antonio; Fabbro, Dora; Mariuzzi, Laura; Marzinotto, Stefania; Toffoletto, Barbara; Perosa, Anna R; Damante, Giuseppe

    2016-04-01

    Human immunoglobulin molecules are generated by a pair of identical heavy chains, which identify the immunoglobulin class, and a pair of identical light chains, Kappa or Lambda alternatively, which characterize the immunoglobulin type. In normal conditions, Kappa light chains represent approximately 2/3 of the light chains of total immunoglobulins, both circulating and lymphocyte surface bound. Very few cases of immunoglobulin Kappa or Lambda light chain defects have been reported. Furthermore, the genetic basis of this defect has been extensively explored only in a single case. We report a case of a patient suffering of serious recurrent bacterial infections, which was caused by a very rare form of immunoglobulin disorder, consisting of a pure defect of Kappa light chain. We evaluated major serum immunoglobulin concentrations, as well as total and free Kappa and Lambda light chain concentrations. Lymphocyte phenotyping was also performed and finally we tested the Kappa chain VJ rearrangement as well as the constant Kappa region sequence. Studies performed on VJ rearrangement showed a polyclonal genetic arrangement, whereas the gene sequencing for the constant region of Kappa chain showed a homozygous T to G substitution at the position 1288 (rs200765148). This mutation causes a substitution from Cys to Gly in the protein sequence and, therefore, determines the abnormal folding of the constant region of Kappa chain. We suggest that this defect could lead to an effective reduction of the variability of total antibody repertoire and a consequent defect of an apparently normal immunoglobulin response to common antigens.

  5. The distinctiveness heuristic in false recognition and false recall.

    Science.gov (United States)

    McCabe, David P; Smith, Anderson D

    2006-07-01

    The effects of generative processing on false recognition and recall were examined in four experiments using the Deese-Roediger-McDermott false memory paradigm (Deese, 1959; Roediger & McDermott, 1995). In each experiment, a Generate condition in which subjects generated studied words from audio anagrams was compared to a Control condition in which subjects simply listened to studied words presented normally. Rates of false recognition and false recall were lower for critical lures associated with generated lists, than for critical lures associated with control lists, but only in between-subjects designs. False recall and recognition did not differ when generate and control conditions were manipulated within-subjects. This pattern of results is consistent with the distinctiveness heuristic (Schacter, Israel, & Racine, 1999), a metamemorial decision-based strategy whereby global changes in decision criteria lead to reductions of false memories. This retrieval-based monitoring mechanism appears to operate in a similar fashion in reducing false recognition and false recall.

  6. IMMUNOREGULATORY EFFECTS OF INTRAVENOUS IMMUNOGLOBULINS

    Directory of Open Access Journals (Sweden)

    S. A. Sel'kov

    2013-01-01

    Full Text Available Treatment with intravenous immunoglobulins (IVIG is widely used in modern clinical practice inorder to cure different clinical disorders, including obstetric conditions. Currently, IVIGs have become drugs of  choice  for  treatment of  anti-phospholipid  syndrome  in pregnant women,  like  as  in  cases of  intrauterine cytomegalovirus infection.

  7. Hypnotizability, not suggestion, influences false memory development.

    Science.gov (United States)

    Dasse, Michelle N; Elkins, Gary R; Weaver, Charles A

    2015-01-01

    Hypnotizability influences the development of false memories. In Experiment 1, participants heard a positive or negative suggestion regarding hypnosis and then listened to 8 Deese-Roediger-McDermott (DRM) false memory paradigm lists in a hypnotic state. Neither hypnosis nor prehypnotic suggestion affected memory. Highly hypnotizable participants were more accurate in recall and recognition. In Experiment 2, suggestions were delivered in the form of feedback. Participants heard a positive or negative suggestion about their performance prior to either the encoding or retrieval of 8 DRM lists. Neither accurate nor false memories were affected by the suggestion. Highly hypnotizable individuals recognized fewer critical lures if they received a negative suggestion about their performance. These results highlight the unusual role of hypnotizability in the creation of false memories.

  8. 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

    BACKGROUND: Reference change values provide objective tools to assess the significance of a change in two consecutive results for a biomarker from an individual. The reference change value calculation is based on the assumption that within-subject biological variation has random fluctuation around...... 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...... was based on standard deviations according to the assumption of normality, but was soon changed to coefficients of variation (CV) in the formula (reference change value = ± Z ċ 2(½) ċ CV). Z is being dependent on the desired probability of significance, which also defines the percentages of false...

  9. Blood Test: Immunoglobulin A (IgA)

    Science.gov (United States)

    ... to 2-Year-Old Blood Test: Immunoglobulin A (IgA) KidsHealth > For Parents > Blood Test: Immunoglobulin A (IgA) Print A A A What's in this article? ... Questions en español Análisis de sangre: inmunoglobulina A (IgA) What It Is An IgA test measures the ...

  10. Sleep deprivation and false memories.

    Science.gov (United States)

    Frenda, Steven J; Patihis, Lawrence; Loftus, Elizabeth F; Lewis, Holly C; Fenn, Kimberly M

    2014-09-01

    Many studies have investigated factors that affect susceptibility to false memories. However, few have investigated the role of sleep deprivation in the formation of false memories, despite overwhelming evidence that sleep deprivation impairs cognitive function. We examined the relationship between self-reported sleep duration and false memories and the effect of 24 hr of total sleep deprivation on susceptibility to false memories. We found that under certain conditions, sleep deprivation can increase the risk of developing false memories. Specifically, sleep deprivation increased false memories in a misinformation task when participants were sleep deprived during event encoding, but did not have a significant effect when the deprivation occurred after event encoding. These experiments are the first to investigate the effect of sleep deprivation on susceptibility to false memories, which can have dire consequences.

  11. Prognostic Value Of Immunoglobulin Profile In Human Papilloma Virus Infection

    National Research Council Canada - National Science Library

    Chattopadhyay S P

    2001-01-01

    Present study aimed at defining the prognostic value of immunoglobulin profile in human papilloma virus infection by assessing and correlating the levels of immunoglobulin with type, number, duration...

  12. HPLC chromatofocusing of human immunoglobulins.

    Science.gov (United States)

    Waldrep, J C; Schulte, J R

    1989-03-31

    A method is described for fractionation and analysis of IgA, IgM, and IgG and antibodies in human serum and/or plasma using a combination of HPLC chromatofocusing and immunoassay. A pH 9.0-3.2 gradient is utilized to separate the major proteins in the complex biological samples and monoclonal antibody based ELISAs used to determine the isotype profiles. Antigen-specific ELISAs are subsequently utilized to determine the distribution of antibody species within the chromatofocused specimens. This method is versatile since multiple simultaneous assays can easily be run on each fraction generating extensive qualitative information regarding immunoglobulin classes, subclasses, and antibodies and their distribution profiles. Such spectra will prove useful for experimental kinetic analysis of the humoral immune status of humans and experimental animals.

  13. Linear immunoglobulin A bullous dermatosis.

    Science.gov (United States)

    Fortuna, Giulio; Marinkovich, M Peter

    2012-01-01

    Linear immunoglobulin A (IgA) bullous dermatosis, also known as linear IgA disease, is an autoimmune mucocutaneous disorder characterized by subepithelial bullae, with IgA autoantibodies directed against several different antigens in the basement membrane zone. Its immunopathologic characteristic resides in the presence of a continuous linear IgA deposit along the basement membrane zone, which is clearly visible on direct immunofluorescence. This disorder shows different clinical features and distribution when adult-onset of linear IgA disease is compared with childhood-onset. Diagnosis is achieved via clinical, histopathologic, and immunopathologic examinations. Two common therapies are dapsone and sulfapyridine, which reduce the inflammatory response and achieve disease remission in a variable period of time.

  14. False Belief vs. False Photographs: A Test of Theory of Mind or Working Memory?

    Science.gov (United States)

    Callejas, Alicia; Shulman, Gordon L; Corbetta, Maurizio

    2011-01-01

    Theory of mind (ToM), the ability to reason about other people's thoughts and beliefs, has been traditionally studied in behavioral and neuroimaging experiments by comparing performance in "false belief" and "false photograph" (control) stories. However, some evidence suggests that these stories are not matched in difficulty, complicating the interpretation of results. Here, we more fully evaluated the relative difficulty of comprehending these stories and drawing inferences from them. Subjects read false belief and false photograph stories followed by comprehension questions that probed true ("reality" questions) or false beliefs ("representation" questions) appropriate to the stories. Stories and comprehension questions were read and answered, respectively, more slowly in the false photograph than false belief conditions, indicating their greater difficulty. Interestingly, accuracy on representation questions for false photograph stories was significantly lower than for all other conditions and correlated positively with participants' working memory span scores. These results suggest that drawing representational inferences from false photo stories is particularly difficult and places heavy demands on working memory. Extensive naturalistic practice with ToM reasoning may enable a more flexible and efficient mental representation of false belief stories, resulting in lower memory load requirements. An important implication of these results is that the differential modulation of right temporal-parietal junction (RTPJ) during ToM and "false photo" control conditions may reflect the documented negative correlation of RTPJ activity with working memory load rather than a specialized involvement in ToM processes.

  15. 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…

  16. Non-secretory immunoglobulin E myeloma associated with immunoglobulin G monoclonal gammopathy of undetermined significance

    Directory of Open Access Journals (Sweden)

    Masako Yasuyama

    2012-07-01

    Full Text Available A 68-year old woman came to our hospital with a severe case of anemia. Serum immunoelectropheresis identified a monoclonal immunoglobulin (Ig G and κ protein. The serum IgE level was within the nomal range and the amounts of remaining immuno - globlins were low. On bone marrow aspirate, plasma cells made up 55.5% of nucleated cells and the plasma cells showed positive readings for IgE κ and IgG by immunohistochemistry. Serum immunofixation did not reveal the IgE monoclonal band. She was diagnosed as having non-secretory IgE myeloma with IgG monoclonal gammopathy of undetermined significance. The nature of this rare myeloma will be discussed.

  17. Immunoglobulin Replacement Therapy for Primary Immunodeficiency.

    Science.gov (United States)

    Sriaroon, Panida; Ballow, Mark

    2015-11-01

    Immunoglobulin replacement therapy has been standard treatment in patients with primary immunodeficiency diseases for the past 3 decades. The goal of therapy is to reduce serious bacterial infections in individuals with antibody function defects. Approximately one-third of patients receiving intravenous immunoglobulin treatment experience adverse reactions. Recent advances in manufacturing processes have resulted in products that are safer and better tolerated. Self-infusion by the subcutaneous route has become popular and resulted in better quality of life. This review summarizes the use of immunoglobulin therapy in primary immunodeficiency diseases including its properties, dosing, adverse effects, and different routes of administration.

  18. [Immunoglobulin G4-associated to multiorganic lymphoproliferative disease].

    Science.gov (United States)

    Bourlon, María T; Chapa, Mónica; Chablé Montero, Fredy; Hernández Calleros, Jorge

    2011-01-01

    We report a case of a woman with lymphoproliferative multiorganic immunoglobulin G4 (IgG4) related disease with extensive involvement showing dacryoadenitis, sialoadenitis, parotiditis, pancreatitis, pneumonitis, lymphadenopathy and immune thrombocytopenic purpura. Serum elevation of acute phase reactant, polyclonal hypergammaglobulinemia, positivity for antinuclear antibodies and rheumatoid factor was found. Hystologically plasma cell infiltration was demonstrated on glandular and lymphatic tissue and immunochemistry was positive for IgG4 in > 30%. Immunosuppressive treatment with steroids and azathioprine was given with an excellent clinical response, the marked radiologic evidence of improvement and the decrease in inflammatory makers that conducted to symptom remission are shown in the text.

  19. A Study of False-Positive and False-Negative Error Rates in Cartridge Case Comparisons

    Science.gov (United States)

    2014-04-07

    Defense Biometrics and Forensics Office, Assistant Secretary of Defense (Research and Engineering), through the U.S. Department of Energy Contract No...official policies, either expressed or implied, of the Defense Biometrics and Forensics Office, Defense Forensic Science Center, or the U.S...Acknowledgements This work was supported by Defense Biometrics and Forensics Office through the U.S. Department of Energy under Contract No. DE-AC02

  20. Drug testing welfare recipients--false positives, false negatives, unanticipated opportunities.

    Science.gov (United States)

    Pollack, Harold A; Danziger, Sheldon; Jayakody, Rukmalie; Seefeldt, Kristin S

    2002-01-01

    Substance abuse and dependence are among the most common psychiatric disorders among pregnant and parenting women. These disorders among welfare recipients have attracted special concern. Chemical testing has been proposed to identify illicit drug use in this population. This analysis scrutinizes the potential value of drug testing, using recent data from the Women's Employment Study and the National Household Survey of Drug Abuse. One-fifth of recipients reported illicit substance use during the previous year. However, less than 5% satisfied diagnostic screening criteria for illicit drug dependence. Most recipients with psychiatric disorders or alcohol dependence reported no recent illicit drug use, and, thus, would not be detected through chemical tests. Although illicit drug users are rarely dependent, many face barriers to self-sufficiency. Screening and assessment programs should distinguish use from dependence, and should also identify alcohol dependence and psychiatric disorders. States should provide a range of treatment services to address these concerns.

  1. Epstein-Barr virus infection in vitro can rescue germinal center B cells with inactivated immunoglobulin genes.

    Science.gov (United States)

    Chaganti, Sridhar; Bell, Andrew I; Pastor, Noelia Begue; Milner, Anne E; Drayson, Mark; Gordon, John; Rickinson, Alan B

    2005-12-15

    Immunoglobulin genotyping of Epstein-Barr virus (EBV)-positive posttransplantation lymphoproliferative disease has suggested that such lesions often arise from atypical post-germinal center B cells, in some cases carrying functionally inactivated immunoglobulin genes. To investigate whether EBV can rescue cells that are failed products of the somatic hypermutation process occurring in germinal centers (GCs), we isolated GC cells from tonsillar cell suspensions and exposed them to EBV in vitro. Screening more than 100 EBV-transformed cell lines of GC origin identified 6 lines lacking surface immunoglobulin, a phenotype never seen among lines derived from circulating naive or memory B cells. Furthermore, 3 of the 6 surface immunoglobulin-negative GC lines carried inactivating mutations in the immunoglobulin H (IgH) variable gene sequence. The ability of EBV to rescue aberrant products of the germinal center reaction in vitro strengthens the probability that a parallel activity contributes to EBV's lymphomagenic potential in vivo.

  2. An effective method for controlling false discovery and false nondiscovery rates in genome-scale RNAi screens.

    Science.gov (United States)

    Zhang, Xiaohua Douglas

    2010-10-01

    In most genome-scale RNA interference (RNAi) screens, the ultimate goal is to select siRNAs with a large inhibition or activation effect. The selection of hits typically requires statistical control of 2 errors: false positives and false negatives. Traditional methods of controlling false positives and false negatives do not take into account the important feature in RNAi screens: many small-interfering RNAs (siRNAs) may have very small but real nonzero average effects on the measured response and thus cannot allow us to effectively control false positives and false negatives. To address for deficiencies in the application of traditional approaches in RNAi screening, the author proposes a new method for controlling false positives and false negatives in RNAi high-throughput screens. The false negatives are statistically controlled through a false-negative rate (FNR) or false nondiscovery rate (FNDR). FNR is the proportion of false negatives among all siRNAs examined, whereas FNDR is the proportion of false negatives among declared nonhits. The author also proposes new concepts, q*-value and p*-value, to control FNR and FNDR, respectively. The proposed method should have broad utility for hit selection in which one needs to control both false discovery and false nondiscovery rates in genome-scale RNAi screens in a robust manner.

  3. False allegation of child abduction.

    Science.gov (United States)

    Canning, Kathleen E; Hilts, Mark A; Muirhead, Yvonne E

    2011-05-01

    Cases in which a child has been falsely reported as missing or abducted can be extremely challenging to the law enforcement agencies responsible for their investigation. In the absence of a witnessed abduction or an obvious crime scene, it is difficult to determine whether a child has actually been abducted or has become a victim of a homicide and a false allegation. The purpose of this study was to examine falsely alleged kidnapping cases and identify successful investigative strategies. Sixty-one adjudicated false allegation cases involving 66 victims were analyzed. The mean age of the victim was 5 years. Victims came from generally unstable, high-risk family situations and were killed primarily by biological parents. Victims were killed because they were unwanted or viewed as an obstacle to a desired goal, or they were victims of abuse or maltreatment that ended in fatality.

  4. Sleep deprivation and false confessions.

    Science.gov (United States)

    Frenda, Steven J; Berkowitz, Shari R; Loftus, Elizabeth F; Fenn, Kimberly M

    2016-02-23

    False confession is a major contributor to the problem of wrongful convictions in the United States. Here, we provide direct evidence linking sleep deprivation and false confessions. In a procedure adapted from Kassin and Kiechel [(1996) Psychol Sci 7(3):125-128], participants completed computer tasks across multiple sessions and repeatedly received warnings that pressing the "Escape" key on their keyboard would cause the loss of study data. In their final session, participants either slept all night in laboratory bedrooms or remained awake all night. In the morning, all participants were asked to sign a statement, which summarized their activities in the laboratory and falsely alleged that they pressed the Escape key during an earlier session. After a single request, the odds of signing were 4.5 times higher for the sleep-deprived participants than for the rested participants. These findings have important implications and highlight the need for further research on factors affecting true and false confessions.

  5. 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...

  6. 7th International Immunoglobulin Conference: Poster presentations.

    Science.gov (United States)

    Warnatz, K; Ballow, M; Stangel, M; Bril, V

    2014-12-01

    The pan-European survey provides useful information on the accessibility and trends of intravenous and subcutaneous immunoglobulin (IVIg/SCIg) therapy, which is used to treat primary immunodeficiency disorders (PIDs). Although immunoglobulin (Ig) therapy is the first-line treatment for PIDs, the mechanisms of action of Ig therapy may differ according to the condition it is used to treat. Moreover, intriguing presentations suggest that further investigation is required to understand more clearly both the haematological and immunoregulatory effects of therapeutic immunoglobulin. This can ultimately provide more information on optimizing Ig therapy efficacy, and establish whether individualized dosing regimens for patients will be conducive to better clinical outcomes. In addition to treating autoimmune and inflammatory conditions, there is evidence to suggest that immunoglobulins can potentially play a role in transplantation, which warrants further investigation for future use.

  7. Thermodynamic stability contributes to immunoglobulin specificity.

    Science.gov (United States)

    Dimitrov, Jordan D; Kaveri, Srinivas V; Lacroix-Desmazes, Sébastien

    2014-05-01

    Antigen-binding specificity of immunoglobulins is important for their function in immune defense. However, immune repertoires contain a considerable fraction of immunoglobulins with promiscuous binding behavior, the physicochemical basis of which is not well understood. Evolution of immunoglobulin specificity occurs through iterative processes of mutation and selection, referred to as affinity maturation. Recent studies reveal that some somatic mutations could compromise the thermodynamic stability of the variable regions of immunoglobulins. By integrating this observation with the wealth of data on the evolution of novel enzyme activities, we propose that antibody specificity is linked to the thermodynamic stability of the antigen-binding regions, which provides a quantitative distinction between highly specific and promiscuous antibodies.

  8. 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.

  9. DIAGNOSTIC AND PROGNOSTIC SIGNIFICANCE OF INTRATHECAL SYNTHESIS OF IMMUNOGLOBULIN FREE LIGHT CHAINS IN MULTIPLE SCLEROSIS

    Directory of Open Access Journals (Sweden)

    V. D. Nazarov

    2015-01-01

    Full Text Available Increased intrathecal synthesis and oligoclonal banding of immunoglobulins (Ig in cerebrospinal fluid (CSF are major immunological findings in multiple sclerosis. Free light chains are fragments of Ig molecules that are produced in parallel to oligoclonal Ig, and their production reflects total Ig synthesis within central nervous system. Assessment of intrathecal kappaand lambda free light chain production within CNS compartment will help to improve diagnosis and prediction of outcomes in multiple sclerosis. Concentrations of kappa and lambda free light chains and clonality of immunoglobulin pattern synthesis were studied in paired CSF and serum samples of 151 patients, including 92 patients with multiple sclerosis, and 33 patients with clinically isolated syndrome which later was transformed into the definite multiple sclerosis. A control group consisted of 26 patients with other inflammatory diseases of central nervous system. Several Ig parameters have been determined in the patients, i.e., Ig clonality in CSF; concentrations of free light chains (both kappaand lambda- in CSF; as well as their indexes and ratios. It was established that synthesis of kappa free light chains were significantly elevated in patients with multiple sclerosis. Moreover, the amounts of free light Ig chains in patients with positive oligoclonality test were significantly higher than in cases without intrathecal oligoclonal synthesis. With respect to diagnostic significance, the kappa quotient proved the best available option for diagnosis of multiple sclerosis. Its combination with Ig oligoclonality assays caused a decrease in false-negative diagnostics by 42%. Diagnostic benefit of the kappa quotient could be also confirmed by the data of ROC analysis. Also concentration of lambda free light chains in cerebrospinal fluid showed a negative correlation with conversion terms of clinically isolated syndrome to evident multiple sclerosis. Therefore, the indexes of free Ig

  10. Immunoglobulin A nephropathy: Basic characteristics

    Directory of Open Access Journals (Sweden)

    Petrović Lada

    2003-01-01

    Full Text Available Introduction Immunoglobulin A nephropathy (IgAN is one of the most common forms of primary glomerulonephritis in many countries. Most clinical features of IgAN point to a renal problem, such as recurrent macroscopic hematuria or asymptomatic microscopic hematuria and proteinuria. Pathologic features of IgAN present with different types and different degrees of glomerular tubulointerstitial and vascular lesions. The aim of this study was detailed analysis of clinical and laboratory findings, as well as findings of immunofluorescence and light microscopy. We also investigated associations between these factors. Material and methods We investigated 60 patients who underwent renal biopsy. The study was partly retrospective and partly prospective. Results The average age of patients was 34.19 years. Male female ratio was 2.33:1. IgAN was most frequently asymptomatic (83.33% as microhematuria and proteinuria, while gross hematuria was found in 16.667%. Renal biopsy material was analyzed by light microscopy revealing changes in all glomerular structures. Immunofluorescence microscopy demonstrated dominant IgA deposits. This study established association of glomerulosclerosis with clinical features of disease. Discussion and conclusions IgAN frequently develops in the 4th decade of life, mostly in males and presents as asymptomatic (83.33%. Patohistological changes include all glomerular structures. There is no specific serological test for IgAN, but pathological changes affect clinical features of the disease, as proteinuria and increase of creatinine concentration.

  11. Cytomegalovirus Immunoglobulin After Thoracic Transplantation

    Science.gov (United States)

    Grossi, Paolo; Mohacsi, Paul; Szabolcs, Zoltán; Potena, Luciano

    2016-01-01

    Abstract Cytomegalovirus (CMV) is a highly complex pathogen which, despite modern prophylactic regimens, continues to affect a high proportion of thoracic organ transplant recipients. The symptomatic manifestations of CMV infection are compounded by adverse indirect effects induced by the multiple immunomodulatory actions of CMV. These include a higher risk of acute rejection, cardiac allograft vasculopathy after heart transplantation, and potentially bronchiolitis obliterans syndrome in lung transplant recipients, with a greater propensity for opportunistic secondary infections. Prophylaxis for CMV using antiviral agents (typically oral valganciclovir or intravenous ganciclovir) is now almost universal, at least in high-risk transplants (D+/R−). Even with extended prophylactic regimens, however, challenges remain. The CMV events can still occur despite antiviral prophylaxis, including late-onset infection or recurrent disease, and patients with ganciclovir-resistant CMV infection or who are intolerant to antiviral therapy require alternative strategies. The CMV immunoglobulin (CMVIG) and antiviral agents have complementary modes of action. High-titer CMVIG preparations provide passive CMV-specific immunity but also exert complex immunomodulatory properties which augment the antiviral effect of antiviral agents and offer the potential to suppress the indirect effects of CMV infection. This supplement discusses the available data concerning the immunological and clinical effects of CMVIG after heart or lung transplantation. PMID:26900989

  12. Use of intravenous immunoglobulin in pediatric practice

    Science.gov (United States)

    Zülfikar, Bülent; Koç, Başak

    2014-01-01

    In recent years, human-driven intravenous immunoglobulins (IVIG) administered intravenously have been widely used in treatment of many diseases. Intravenous immunoglobulin is obtained from human-driven plasma pools as in other plasma-driven products and IVIG preperations contain structurally and functionally intact immunoglobulin. Intravenous immunoglobulin was approved by FDA (Food and Drug Administration) in USA in 1981 for the first time and was started to be primarily used in patients with immune deficiency with hypogammaglobulinemia. The effects of intravenous immunoglobulin include complex mechanisms, but it exerts its essential action by eliminating the non-specific Fc receptors found in the mononuclear phagocytic system or by inhibiting binding of immune complexes to Fc receptors in the cells. Their areas of usage include conditions where their anti-inflammatory and immunomudulator effects are utilized in addition to replacement of deficient immunoglobulin. Although the definite indications are limited, it has been shown that it is useful in many diseases in clinical practice. Its side effects include fever, sweating, nausea, tachycardia, eczematous reactions, aseptic meningitis, renal failure and hematological-thromboembolic events. In this article, use of IVIG, its mechanisms of action, indications and side effects were discussed. PMID:26078679

  13. Diagnostic Mammograms Find More Cancers, and More False-Positives

    Science.gov (United States)

    ... prove to be unnecessary, he said. But, Dr. Debra Monticciolo, chair of the American College of Radiology ... surgery, University of Vermont College of Medicine, Burlington; Debra Monticciolo, M.D., professor, radiology, Texas A&M ...

  14. Protein-protein interaction assays: eliminating false positive interactions

    OpenAIRE

    Nguyen, Tuan N.; Goodrich, James A.

    2006-01-01

    Many methods commonly used to identify and characterize interactions between two or more proteins are variations of the immobilized protein-protein interaction assay (for example, glutathione S-transferase (GST) pulldown and coimmunoprecipitation). A potential, and often overlooked, problem with these assays is the possibility that an observed interaction is mediated not by direct contact between proteins, but instead by nucleic acid contaminating the protein preparations. As a negatively cha...

  15. 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.

  16. 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…

  17. The Danger of False Dichotomies.

    Science.gov (United States)

    LaBoskey, Vicky Kubler

    1998-01-01

    Responds to an article that examined 10 dichotomies in teacher education (SP 527 128), suggesting that too much time and energy are spent debating false dichotomies and addressing two specific dichotomies (preservice versus inservice and campus versus school site). Recommends that professional educators pool their energy and collaborate (rather…

  18. Secretory immunoglobulin A and immunoglobulin G in horse saliva.

    Science.gov (United States)

    Palm, Anna-Karin E; Wattle, Ove; Lundström, Torbjörn; Wattrang, Eva

    2016-11-01

    This study aimed to increase the knowledge on salivary antibodies in the horse since these constitute an important part of the immune defence of the oral cavity. For that purpose assays to detect horse immunoglobulin A (IgA) including secretory IgA (SIgA) were set up and the molecular weights of different components of the horse IgA system were estimated. Moreover, samples from 51 clinically healthy horses were tested for total SIgA and IgG amounts in saliva and relative IgG3/5 (IgG(T)) and IgG4/7 (IgGb) content were tested in serum and saliva. Results showed a mean concentration of 74μg SIgA/ml horse saliva and that there was a large inter-individual variation in salivary SIgA concentration. For total IgG the mean concentration was approx. 5 times lower than that of SIgA, i.e. 20μg IgG/ml saliva and the inter-individual variation was lower than that observed for SIgA. The saliva-serum ratio for IgG isotypes IgG3/5 and IgG4/7 was also assessed in the sampled horses and this analysis showed that the saliva-serum ratio of IgG4/7 was in general approximately 4 times higher than that of IgG3/5. The large inter-individual variation in salivary SIgA levels observed for the normal healthy horses in the present study emphasises the need for a large number of observations when studying this parameter especially in a clinical setting. Moreover, our results also indicated that some of the salivary IgG does not originate from serum but may be produced locally. Thus, these results provide novel insight, and a base for further research, into salivary antibody responses of horses. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Cow's milk with active immunoglobulins against Campylobacter jejuni: effects of temperature on immunoglobulin activity.

    Science.gov (United States)

    Riera, Francisco; Alvarez, Alejandro; Espi, Alberto; Prieto, Miguel; de la Roza, Begoña; Vicente, Fernando

    2014-04-01

    Adult Holstein cows were injected with an antiserum against Campylobacter jejuni and immunoglobulin activities in vitro were determined in blood and milk several weeks after injection. The immunoactivity of immunoglobulins in milk was measured by an ELISA after different temperature-time treatments (60-91°C and 4-3600 s) at laboratory and pilot-plant scales. Kinetic and thermodynamic parameters were determined. An increase in immunoglobulin activity in milk was detected several days after injection. Optical densities increased by three- to seven-fold in this period. The activity started to decay 4-5 weeks after injection. Immunoglobulins maintained most of their in vitro activity under pasteurisation conditions (72°C and 15 s) and were denatured following first-order kinetics. The injection protocol applied allows milk with specific immunoglobulins against Campylobacter jejuni to be obtained. Traditional pasteurisation did not reduce this activity. © 2013 Society of Chemical Industry.

  20. Outcome Knowledge and False Belief.

    Science.gov (United States)

    Ghrear, Siba E; Birch, Susan A J; Bernstein, Daniel M

    2016-01-01

    Virtually every social interaction involves reasoning about the perspectives of others, or 'theory of mind (ToM).' Previous research suggests that it is difficult to ignore our current knowledge when reasoning about a more naïve perspective (i.e., the curse of knowledge). In this Mini Review, we discuss the implications of the curse of knowledge for certain aspects of ToM. Particularly, we examine how the curse of knowledge influences key measurements of false belief reasoning. In closing, we touch on the need to develop new measurement tools to discern the mechanisms involved in the curse of knowledge and false belief reasoning, and how they develop across the lifespan.

  1. Outcome knowledge and false belief

    Directory of Open Access Journals (Sweden)

    Siba eGhrear

    2016-02-01

    Full Text Available Virtually every social interaction involves reasoning about the perspectives of others, or ‘theory of mind’. Previous research suggests that it is difficult to ignore our current knowledge when reasoning about a more naïve perspective (i.e., the curse of knowledge. In this Mini Review, we discuss the implications of the curse of knowledge for certain aspects of theory of mind. Particularly, we examine how the curse of knowledge influences key measurements of false belief reasoning. In closing, we touch on the need to develop new measurement tools to discern the mechanisms involved in the curse of knowledge and false belief reasoning, and how they develop across the lifespan.

  2. Outcome knowledge and false belief

    OpenAIRE

    Siba eGhrear; Susan eBirch; Daniel eBernstein

    2016-01-01

    Virtually every social interaction involves reasoning about the perspectives of others, or ‘theory of mind’. Previous research suggests that it is difficult to ignore our current knowledge when reasoning about a more naïve perspective (i.e., the curse of knowledge). In this Mini Review, we discuss the implications of the curse of knowledge for certain aspects of theory of mind. Particularly, we examine how the curse of knowledge influences key measurements of false belief reasoning. In closi...

  3. 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.

  4. 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.

  5. 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."

  6. Bug hunting with false negatives

    NARCIS (Netherlands)

    Calamé, Jens; Ioustinova, Natalia; Pol, van de Jaco; Sidorova, Natalia; 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

  7. An Epigenome-Wide Association Study of Total Serum Immunoglobulin E Concentration

    Science.gov (United States)

    Liang, Liming; Wong, Kenny C.C.; Davies, Gwyneth A.; Hudson, Thomas J.; Binia, Aristea; Hopkin, Julian M.; Yang, Ivana V.; Grundberg, Elin; Busche, Stephan; Hudson, Marie; Rönnblom, Lars; Pastinen, Tomi M.; Schwartz, David A.; Lathrop, G. Mark; Moffatt, Miriam F.; Cookson, William O.C.M.

    2014-01-01

    Immunoglobulin E (IgE) is a central mediator of allergic (atopic) inflammation. Therapies directed against IgE benefit hay fever1 and allergic asthma1,2. Genetic association studies have not yet identified novel therapeutic targets or pathways underlying IgE regulation3-6. We therefore surveyed epigenetic association between serum IgE concentrations and methylation at loci concentrated in CpG islands (CGI) genome-wide in 95 nuclear pedigrees, using DNA from peripheral blood leukocytes (PBL). We validated positive results in additional families and in subjects from the general population. We show here replicated associations with a meta-analysis false discovery rate <10−4 between IgE and low methylation at 36 loci. Genes annotated to these loci encode known eosinophil products, and also implicate phospholipid inflammatory mediators, specific transcription factors, and mitochondrial proteins. We confirmed that methylation at these loci differed significantly in isolated eosinophils from subjects with and without high IgE levels. The top three loci accounted for 13% of IgE variation in the primary subject panel, explaining 10 fold higher variance than that derived from large SNP GWAS3,4. The study identifies novel therapeutic targets and biomarkers for patient stratification for allergic diseases. PMID:25707804

  8. Intravenous polyclonal human immunoglobulins in multiple sclerosis

    DEFF Research Database (Denmark)

    Sørensen, Per Soelberg

    2008-01-01

    Intravenous immunoglobulin (IVIG) is an established therapy for demyelinating diseases of the peripheral nervous system. IVIG exerts a number of effects that may be beneficial in multiple sclerosis (MS). Four double-blind IVIG trials have been performed in relapsing-remitting MS. A meta...

  9. Immunoglobulins and their fragments on solid surfaces.

    NARCIS (Netherlands)

    Buijs, J.A.G.

    1995-01-01

    SummaryAdsorption 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 molecules are immobilised

  10. Estimation of bovine colostral immunoglobulins by refractometry.

    Science.gov (United States)

    Molla, A

    1980-07-12

    The total protein of colostral whey from dairy cows as determined by a refractometer were compared with the immune globulin concentration obtained by cellulose acetate membrane electrophoresis and the immunoglobulin (IgA + IgG + IgM) contents determined by radial immunodiffusion. The coefficient of correlation between the results obtained by refractometry and electrophoresis was 0.98 (P whey.

  11. 6th International Immunoglobulin Symposium: Poster presentations

    NARCIS (Netherlands)

    Fernandez-Cruz, E.; Kaveri, S.V.; Peter, H.H.; Durandy, A.; Cantoni, N.; Quinti, I.; Sorensen, R.; Bussel, J.B.; Danieli, M.G.; Winkelmann, A.; Bayry, J.; Kaesermann, F.; Spaeth, P.; Helbert, M.; Salama, A.; van Schaik, I.N.; Yuki, N.

    2009-01-01

    P>The posters presented at the 6th International Immunoglobulin Symposium covered a wide range of fields and included both basic science and clinical research. From the abstracts accepted for poster presentation, 12 abstracts were selected for oral presentations in three parallel sessions on immunod

  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. False-Positive Results in a Recombinant Severe Acute Respiratory Syndrome-Associated Coronavirus (SARS-CoV) Nucleocapsid-Based Western Blot Assay Were Rectified by the Use of Two Subunits (S1 and S2) of Spike for Detection of Antibody to SARS-CoV

    Science.gov (United States)

    Maache, Mimoun; Komurian-Pradel, Florence; Rajoharison, Alain; Perret, Magali; Berland, Jean-Luc; Pouzol, Stéphane; Bagnaud, Audrey; Duverger, Blandine; Xu, Jianguo; Osuna, Antonio; Paranhos-Baccalà, Glaucia

    2006-01-01

    To evaluate the reactivity of the recombinant proteins expressed in Escherichia coli strain BL21(DE3), a Western blot assay was performed by using a panel of 78 serum samples obtained, respectively, from convalescent-phase patients infected with severe acute respiratory syndrome-associated coronavirus (SARS-CoV) (30 samples) and from healthy donors (48 samples). As antigen for detection of SARS-CoV, the nucleocapsid protein (N) showed high sensitivity and strong reactivity with all samples from SARS-CoV patients and cross-reacted with all serum samples from healthy subjects, with either those obtained from China (10 samples) or those obtained from France (38 serum samples), giving then a significant rate of false positives. Specifically, our data indicated that the two subunits, S1 (residues 14 to 760) and S2 (residues 761 to 1190), resulted from the divided spike reacted with all samples from SARS-CoV patients and without any cross-reactivity with any of the healthy serum samples. Consequently, these data revealed the nonspecific nature of N protein in serodiagnosis of SARS-CoV compared with the S1 and S2, where the specificity is of 100%. Moreover, the reported results indicated that the use of one single protein as a detection antigen of SARS-CoV infection may lead to false-positive diagnosis. These may be rectified by using more than one protein for the serodiagnosis of SARS-CoV. PMID:16522785

  14. Media and democracy: false convergences

    Directory of Open Access Journals (Sweden)

    Francisco C. P. Fonseca

    2006-01-01

    Full Text Available This article discusses the false convergence between the role of the media in promoting democracy and political theories of democracy. With this purpose in mind, we propose critical reflections on arguments that: 1 naturalize the fact that "the news" is a commodity; b focus on the (supposedly public goals of the media, in spite of the reality that their agencies are largely private; c link these agencies to liberal- democratic values. Thus, the text attempts to show both the absence of and need for shields - personified in the theories of weights and counterbalances - against the powers that be, particularly those of the media. We point to the paradox involved in the media's role as intermediary between public and private spheres and question the degree to which the media permit fulfillment of the idea that those have control should be controlled, particularly in a world in which communication has extended its action to the planetary level. We conclude that democracy can only be made effective if democratic controls over the media are exercised; this means the creation of national and international level public information media that would be neither privately nor state owned and managed.

  15. Inconspicuous anchoring effects generated by false information

    Institute of Scientific and Technical Information of China (English)

    Chen Qu; Jun Wang; Yuejia Luo

    2008-01-01

    The impact of false information on numerical judgments was examined on young normal subjects by an event-related potential (ERP) experiment. To imitate the judgments in real world, we ensured the subjects acknowledged of the target task. The behavioral results found that both uncertain information and false information assimilated the final estimates: higher after higher anchors and lower after lower anchors; and false information caused a weaker anchoring bias than uncertain information. ERP results provided further electrophysiological evidence for the mechanism of anchoring. In the early phrase, it was an accessibility-dominated process in which two kinds of anchors elicited an N300 component related to the accessibility of anchors propositions. The knowledge relevant to targets joined the process in the late phrase, which caused a larger amplitude of late positive component (LPC) for implausible lower anchors than that for plausible higher anchors. Source analysis showed that medial frontal gyrus, whose activity was suggested to signal the need of adjustment, was more reliable to explain the LPC elicited by implausible lower anchors. Therefore, we suggest that accessibility is facilitated when the external anchor is consistent with the world knowledge, and adjustment is initiated when the external anchor is inconsistent.

  16. Ontology of the False State

    Directory of Open Access Journals (Sweden)

    Testa Italo

    2015-09-01

    Full Text Available In this paper I will argue that critical theory needs to make its socio-ontological commitments explicit, whilst on the other hand I will posit that contemporary social ontology needs to amend its formalistic approach by embodying a critical theory perspective. In the first part of my paper I will discuss how the question was posed in Horkheimer’s essays of the 1930s, which leave open two options: (1 a constructive inclusion of social ontology within social philosophy, or else (2 a program of social philosophy that excludes social ontology. Option (2 corresponds to Adorno’s position, which I argue is forced to recur to a hidden social ontology. Following option (1, I first develop a meta-critical analysis of Searle, arguing that his social ontology presupposes a notion of ‘recognition’ which it cannot account for. Furthermore, by means of a critical reading of Honneth, I argue that critical theory could incorporate a socio-ontological approach, giving value to the constitutive socio-ontological role of recognition and to the socio-ontological role of objectification. I will finish with a proposal for a socio-ontological characterization of reification which involves that the basic occurrence of recognition is to be grasped at the level of background practices.

  17. 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.

  18. Disbalance of immunoglobulins the clinical importance of increased serum levels of immunoglobulin-A and -G in combination with normal or diminished immunoglobulin-M concentrations

    NARCIS (Netherlands)

    Bakker, H.D.; Imhof, J.W.; Mul, N.A.J.; Ballieux, R.E.

    1967-01-01

    A disbalance of immunoglobulin-A (IgA), immunoglobulin-G (IgG) and immunoglobulin-M (IgM) concentrations—i.e., increased IgA and IgG fractions and a normal or diminished IgM concentration—is not a specific finding but one that frequently occurs in collagen diseases which take a chronic course. In th

  19. Artificial Affinity Proteins as Ligands of Immunoglobulins

    Directory of Open Access Journals (Sweden)

    Barbara Mouratou

    2015-01-01

    Full Text Available A number of natural proteins are known to have affinity and specificity for immunoglobulins. Some of them are widely used as reagents for detection or capture applications, such as Protein G and Protein A. However, these natural proteins have a defined spectrum of recognition that may not fit specific needs. With the development of combinatorial protein engineering and selection techniques, it has become possible to design artificial affinity proteins with the desired properties. These proteins, termed alternative scaffold proteins, are most often chosen for their stability, ease of engineering and cost-efficient recombinant production in bacteria. In this review, we focus on alternative scaffold proteins for which immunoglobulin binders have been identified and characterized.

  20. ABZYME ACTIVITY OF POLYCLONAL IMMUNOGLOBULINS IN SPONDYLOARTHROPATHIES

    Directory of Open Access Journals (Sweden)

    E. V. Kunder

    2009-01-01

    Full Text Available Abstract. Polyclonal immunoglobulins G (subclasses 1, 2, 4 from sera of 255 patients and 69 healthy persons were studied by a combined approach using rivanol treatment and affinity chromatography. Enzymatic reactions were carried out according to the methods that we have previously developed and validated for evaluation of abzyme activity in the patients with different disorders. The levels of DNase, proteolytic BAPNA-amidase (benzoylarginine-p-nitroanilide amidase, and superoxyde dismutase abzyme activity in spondyloarthropathies proved to be significantly higher (p = 0.001, as compared with a control group. Catalase activity of immunoglobulines in the disorders studied was compatible to control levels (p > 0.05. Analysis of relations between abzyme activity and clinical and laboratory signs of the diseases has revealed some significant correlations. Prevalence of abzyme DNAse activity is found in the patients with psoriatic arthritis, as compared to reactive arthritis and ankylosing spondilitis (p < 0.001.

  1. Antarctic teleost immunoglobulins: more extreme, more interesting.

    Science.gov (United States)

    Coscia, Maria Rosaria; Varriale, Sonia; Giacomelli, Stefano; Oreste, Umberto

    2011-11-01

    We have investigated the immunoglobulin molecule and the genes encoding it in teleosts living in the Antarctic seas at the constant temperature of -1.86 °C. The majority of Antarctic teleosts belong to the suborder Notothenioidei (Perciformes), which includes only a few non-Antarctic species. Twenty-one Antarctic and two non-Antarctic Notothenioid species were included in our studies. We sequenced immunoglobulin light chains in two species and μ heavy chains, partially or totally, in twenty species. In the case of heavy chain, genomic DNA and the cDNA encoding the secreted and the membrane form were analyzed. From one species, Trematomus bernacchii, a spleen cDNA library was constructed to evaluate the diversity of VH gene segments. T. bernacchii IgM, purified from the serum and bile, was characterized. Homology Modelling and Molecular Dynamics were used to determine the molecular structure of T. bernacchii and Chionodraco hamatus immunoglobulin domains. This paper sums up the previous results and broadens them with the addition of unpublished data.

  2. [BIOLOGICAL AND IMMUNOCHEMICAL PROPERTIES OF POLYREACTIVE IMMUNOGLOBULINS].

    Science.gov (United States)

    Bobrovnik, S A; Demchenko, M A; Komisarenko, S V

    2015-01-01

    A previously unknown phenomenon of acquired polyreactivity for serum immunoglobulins, which were subjected either to solutions of KSCN (3.0-5.0 M), low/high pH (pH 2.2-3.0), or heating to 58-60 degrees C, was described by us in 1990 year. Much later, eleven years after that, similar data were published by others, which completely confirmed our results concerning the influence of either chaotropic ions or the drastic shift of pH on immunoglobulins polyreactive properties. Our further investigations of polyreactive serum immunoglobulins (PRIG) properties have shown that the mechanism of non-specific interaction between PRIG and antigens much differs from the mechanism of interaction between specific antibodies and corresponding antigens. Later we have shown that the increasing of PRIG reactivity could be induced in vivo, and PRIG are one of serum components for human or animal sera. Then, it could be suggested that PRIG can perform certain biological functions. Studying of PRIG's effect on the phagocytosis of microbes by peritoneal cells or the tumor growth have shown that PRIG can play a certain role in protecting the body from infections and probably can influence on the development of various pathological processes. Recently we have also found that PRIG IgG contents significantly increases in aged people. These data demonstrate that further investigations of PRIG's immunochemical properties and studying of their biological role in organism protection from various diseases is very intriguing and important.

  3. Intra-cerebral injection of neuromyelitis optica immunoglobulin G and human complement produces neuromyelitis optica lesions in mice

    Science.gov (United States)

    Saadoun, Samira; Waters, Patrick; Bell, B. Anthony; Vincent, Angela; Verkman, A. S.

    2010-01-01

    Neuromyelitis optica is an inflammatory demyelinating disease of the central nervous system associated with autoantibodies against the glial water channel protein aquaporin-4. It has recently been reported that immunoglobulin from neuromyelitis optica patients injected peripherally does not cause lesions in naive rats, but only when pre-existing central nervous system inflammation is present. Here, we investigated whether immunoglobulin G from aquaporin-4-autoantibody-positive neuromyelitis optica patients has the potential to damage the central nervous system either alone or in the presence of human complement. Immunoglobulin G from neuromyelitis optica patients did not activate mouse complement and was not pathogenic when injected into mouse brain. However, co-injection of immunoglobulin G from neuromyelitis optica patients with human complement produced neuromyelitis optica-like lesions in mice. Within 12 h of co-injecting immunoglobulin G from neuromyelitis optica patients and human complement, there was a striking loss of aquaporin-4 expression, glial cell oedema, myelin breakdown and axonal injury, but little intra-parenchymal inflammation. At 7 days, there was extensive inflammatory cell infiltration, perivascular deposition of activated complement components, extensive demyelination, loss of aquaporin-4 expression, loss of reactive astrocytes and neuronal cell death. In behavioural studies, mice injected with immunoglobulin G from neuromyelitis optica patients and human complement into the right hemisphere preferentially turned to the right at 7 days. No brain inflammation, demyelination or right-turning behaviour was seen in wild-type mice that received immunoglobulin G from non-neuromyelitis optica patients with human complement, or in aquaporin-4-null mice that received immunoglobulin G from neuromyelitis optica patients with human complement. We conclude that co-injection of immunoglobulin G from neuromyelitis optica patients with human complement

  4. 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.

  5. [Immunoglobulins or plasma exchange? Guillain-Barré syndrome: indications for plasma exchange and immunoglobulins].

    Science.gov (United States)

    Raphaël, J C; Chevret, S; Jars-Guincestre, M C; Chastang, C; Gajdos, P

    1993-01-01

    The effect of plasma exchange (PE) in the Guillain-Barré syndrome (GBS) has been evaluated in 4 randomized clinical trials. A positive effect could be excluded in only one study conducted in Great Britain which included 29 patients. The more powerful studies conducted in Sweden (39 patients), in North America (245 patients) and in France (220 patients) demonstrated that early use of four PEs in patients with a GBS severe enough to require assistance in walking was followed by decreased duration and severity of the acute phase. These conclusions were ratified at a North American consensus conference. More recently, PE has been demonstrated to increase the number of patients who recover normal muscular power after a 1-year follow-up. The French trial also demonstrated that diluted albumin should be preferred over fresh frozen plasma. The number of plasma exchanges and the role of PE in initially benign forms is of great importance and is now under study by a cooperative group in France. The effect of immunoglobulins (IgG) was recently investigated in a randomized trial including 150 patients. In this study, high doses (0.4 g/kg/day for 5 days) were compared with 5 PE administered between days 7 and 14 in children and adults who, at inclusion, were unable to walk. The main result was that the outcome at one month was good with IgG as with PE. Treatment is easier with IgG, and morbidity is lower. Direct costs are similar. If IgG are shown to be as effective as PE, IgG should be given for GBS.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. 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.

  7. Relationship between Human Immunoglobulin and Complement andthe Positive Results of Different Items in the Anti-extractable Nuclear Antigen with the Titer of Antinuclear Antibodies%抗核抗体滴度与IgG,C3,C4水平及抗ENA抗体结果的相关性

    Institute of Scientific and Technical Information of China (English)

    舒颖; 张平安; 魏新素; 叶芳丽; 周心房

    2013-01-01

    Objective To explore the relationship between immunoglobulin G(IgG) and complement 3 (C3) and C4 with the titer of antinuclear antibodies (ANA) ,and to investigate the correlation between the positive results of different items in the anti-extractable nuclear antigen (anti-ENA) with the titer of ANA.Methods The author analysed the results of autoimmune detection of 1813 patients from May 2010 to June 2012.ANA were tested by indirect immunofluorescence method,anti-ENA antibody were tested by ELISA method,IgG and C3,C4 were determined by immunoturbidimetry.According to the different titers,the patients were divided into several groups,the titer of ANA=1:100 as group l,the titer of ANA=1: 160 as group 2,the titer of ANA=1:320 as group 3,the titer of ANA=1:640 as group 4,the titer of ANA=1:1 280 as group 5,the titer of ANA=1:3 200 as group 6, the titer of ANA>3 200 as group 7,120 cases randomly selected from ANA<1:100 group as group 8(negative group).The change of IgG and complement as well as the positive rates of the specific antibodies of anti-ENA were analyzed by SPSS17.0 software.Results When the titer of ANA≥1:100,the levels of IgG were obviously higher than that in the negative group (F=31.19, P<0.05).When the titer of ANA≥1:320, the levels of C3 and C4 were lower than that in the negative group(F=42.15,9.57,P<0.05).Overall anti-ENA positive rates increased significantly with the titer of ANA (χ2=86.67, P<0.05) ,and the positive rates of various antibodies were different.Anti-SSA and anti-SSB were the most frequent at ANA titers of 1 : 100 to 1 : 3 200,while anti-U1RNP were the most frequent at ANA titers of 1:3 200.Conclusion IgG and C3,C4 were related to the titer of ANA.The positive rates of the overall anti-ENA and some specific antibodies of anti-ENA were related to the titer of ANA.The clinician should pay attention to the value of ANA titer in autoimmune disease diagnosis.%目的 探讨抗核抗体(antinuclear antibodies,ANA)滴度与IgG,C3和C4的

  8. Immunoglobulin G4-related disease presenting with obstructive jaundice

    Directory of Open Access Journals (Sweden)

    Yuan-Rung Li

    2014-06-01

    Full Text Available A 48-year-old male presented with diffuse abdominal fullness for 1 month and tea-colored urine for 10 days. Abdominal computed tomography/magnetic resonance cholangiopancreatography revealed diffuse enlargement of the pancreas and unusual soft tissue density around the left ureter. Endoscopic retrograde cholangiopancreatography demonstrated lumen narrowing of the distal common bile duct and irregularity of the pancreatic duct. Markedly elevated serum immunoglobulin G4 (IgG4 was also noted. Biopsy of soft tissue from the area surrounding the left ureter identified lymphoplasmacytic infiltration with high concentrations of IgG4-positive plasma cells accompanied by obliterative phlebitis, compatible with IgG4-related disease. The patient was administered steroid therapy and his symptoms improved. Clinicians should be aware of possible IgG4-related disease in a patient presenting with obstructive jaundice and diffuse pancreatic enlargement because glucocorticoid administration can achieve good response.

  9. 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...

  10. 使用化学发光法检测26707例血清抗梅毒螺旋体特异性抗体以及结果假阳性率分析%Analyze of the False Positive Rate of Serum Anti Treponema Pallidum Specific Antibody of 26 707 Cases Detected by Chemiluminescence Method

    Institute of Scientific and Technical Information of China (English)

    张保平; 刘珊; 韩艳秋

    2015-01-01

    Objective To detect serum anti-Treponema pallidum specific antibody of 26 707 cases by Abbott I2000SR auto-matic chemiluminescent microparticle immunoassay analyzer,and treponema pallidum particle agglutination assay (TPPA) was regarded as a standard reference method which was used to detect anti-Treponema pallidum specific antibody.To analyze the false positive rate of Abbott I2000SR according to the TPPA.Methods Collected 26 707 serums from inpatients and outpatients of the hospital during September 1,2013 to March 5,2014.The subjects were asked to fasting conditions taking venous blood 3 ml,3 000 r/min centrifugal 10 min utes after the separation of serum,detected the Anti-TP by CMIA (Ab-bott I2000SR)and the TPPA testing,analyzed test results by statistical methods.Results There were 52 cases detected by I2000SR whose S/CO values of 26 707 cases of serum Treponema pallidum specific antibodies were 1 to 2,of which 9 cases were verified positive by TPPA,and the positive rate was 17.31%.There were 26 cases detected by I2000SR whose S/CO values of Treponema pallidum specific antibodies were 2 to 3,of which 9 cases were verified positive by TPPA,and the posi-tive rate was 34.62%.There were 26 cases detected by I2000SR whose S/CO values of Treponema pallidum specific anti-bodies were 3 to 5,of which 9 cases were verified positive by TPPA,and the positive rate was 34.62%.There were 25 cases detected by I2000SR whose S/CO values of Treponema pallidum specific antibodies were 5 to 7,of which 11 cases were veri-fied positive by TPPA,and the positive rate was 44%.There were 25 cases detected by I2000SR whose S/CO values of Treponema pallidum specific antibodies were 7 to 10,of which 17 cases were verified positive by TPPA,and the positive rate was 68%.There were 28 cases detected by I2000SR whose S/CO values of Treponema pallidum specific antibodies were 10to 13,of which 24 cases were verified positive by TPPA,and the positive rate was 85.71%.There were 23 cases detected

  11. Successful treatment of systemic lupus erythematosus with subcutaneous immunoglobulin.

    Science.gov (United States)

    Brasileiro, A; Fonseca Oliveira, J; Pinheiro, S; Paiva-Lopes, M J

    2016-05-01

    The therapeutic efficacy of high-dose intravenous immunoglobulin in systemic lupus erythematosus (SLE) patients is well established. However, side effects might limit its use and lead to the consideration of therapeutic alternatives, such as the subcutaneous formulation of immunoglobulin, which has been used in some patients with other autoimmune diseases. We report a case of SLE refractory to classical therapies. High-dose intravenous immunoglobulin was effective, but gave rise to significant side effects. The patient was successfully treated with subcutaneous human immunoglobulin, achieving and maintaining clinical and laboratory remission. A lower immunoglobulin dose was needed and no side effects were observed, compared to the intravenous administration. Subcutaneous immunoglobulin could be a better-tolerated and cost-saving therapeutic option for select SLE patients.

  12. Long-term immunoglobulin therapy for chronic inflammatory demyelinating polyradiculoneuropathy.

    Science.gov (United States)

    Rajabally, Yusuf A

    2015-05-01

    Immunoglobulins are an effective but expensive treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Although the goal is to improve function, use of functional scales to monitor therapy is not widespread. Limited recent evidence suggests that doses lower than those used traditionally may be as effective. There are no proven correlations of effective dose with weight, disease severity, or duration. The clinical course of CIDP is heterogeneous and includes monophasic forms and complete remissions. Careful monitoring of immunoglobulin use is necessary to avoid overtreatment. Definitive evidence for immunoglobulin superiority over steroids is lacking. Although latest trial evidence favors immunoglobulins over steroids, the latter may result in higher remission rates and longer remission periods. This article addresses the appropriateness of first-line, high-dose immunoglobulin treatment for CIDP and reviews important clinical questions regarding the need for long-term therapy protocols, adequate monitoring, treatment withdrawal, and consideration of corticosteroids as an alternative to immunoglobulin therapy.

  13. CANCEROUS IMMUNOGLOBULINS AND CA215: IMPLICATIONS IN CANCER IMMUNOLOGY

    Directory of Open Access Journals (Sweden)

    Gregory Lee

    2012-01-01

    Full Text Available Immunoglobulins are typically expressed by B cells in our normal immune system. However, certain normal human tissues, such as hyperplastic epithelial cells, cells of the immunologically privileged sites and the majority of cancer cells, have also been found to be sites of immunoglobulin production. Current research is lacking in regards to the differential immunoglobulin expression, the underling mechanisms of action and the biological implications of these cancerous immunoglobulins in cancer immunology. This article reviews the etiology of atypical immunoglobulin expression in normal non-B cells and cancer cells, with emphasis on the exploration of the possible mechanisms of action and biological function of these atypical immunoglobulins, by means of specific biological probes. In contrast to immunoglobulins of B cell origins, atypical immunoglobulins were found to carry additional post-translational modifications, including a unique carbohydrateassociated epitope recognized by RP215 monoclonal antibody. This unique RP215-specific epitope enables us to differentiate between these two types of immunoglobulins. Atypical immunoglobulins expressed by cancer cells have been a common subject of interest in cancer immunology. Furthermore, the recent accumulation of experimental evidence has indicated that these atypical immunoglobulins are essential for the growth and proliferation of cancer cells under our normal immune environment. RP215 monoclonal antibody also reacts with many other cancer cell-expressed glycoproteins, known as CA215, on the cancer cell surface. Apoptosis of cultured cancer cells can be induced and growth inhibition of implanted tumors can be observed in nude mouse animal models. Therefore, humanized RP215 monoclonal antibody, which reacts mainly with surface bound CA215, may have the potential to be developed as an anti-cancer drug for the treatment of human cancers. A better understanding of cancer cell

  14. Immunoglobulin G4-Related Pancreatic and Biliary Diseases

    Directory of Open Access Journals (Sweden)

    Hisham Al-Dhahab

    2013-01-01

    Full Text Available BACKGROUND: Autoimmune pancreatitis and autoimmune cholangitis are new clinical entities that are now recognized as the pancreaticobiliary manifestations of immunoglobulin (Ig G4-related disease.

  15. Hyaluronidase facilitated subcutaneous immunoglobulin in primary immunodeficiency

    Directory of Open Access Journals (Sweden)

    Jolles S

    2013-09-01

    Full Text Available Stephen Jolles Department of Immunology, University Hospital of Wales, Cardiff, UK Abstract: Immunoglobulin (Ig-replacement therapy represents the mainstay of treatment for patients with primary antibody deficiency and is administered either intravenously (IVIg or subcutaneously (SCIg. While hyaluronidase has been used in clinical practice for over 50 years, the development of a high-purity recombinant form of this enzyme (recombinant human hyaluronidase PH20 has recently enabled the study of repeated and more prolonged use of hyaluronidase in facilitating the delivery of SC medicines. It has been used in a wide range of clinical settings to give antibiotics, local anesthetics, insulin, morphine, fluid replacement, and larger molecules, such as antibodies. Hyaluronidase has been used to help overcome the limitations on the maximum volume that can be delivered into the SC space by enabling dispersion of SCIg and its absorption into lymphatics. The rate of facilitated SCIg (fSCIg infusion is equivalent to that of IVIg, and the volume administered at a single site can be greater than 700 mL, a huge increase over conventional SCIg, at 20–40 mL. The use of fSCIg avoids the higher incidence of systemic side effects of IVIg, and it has higher bioavailability than SCIg. Data on the long-term safety of this approach are currently lacking, as fSCIg has only recently become available. fSCIg may help several areas of patient management in primary antibody deficiency, and the extent to which it may be used in future will depend on long-term safety data and cost–benefit analysis. Keywords: enzyme facilitated IgG infusion, recombinant human hyaluronidase PH20, subcutaneous immunoglobulin, intravenous immunoglobulin, primary immunodeficiency disease

  16. Immunoglobulin Fc gamma receptor promotes immunoglobulin uptake, immunoglobulin-mediated calcium increase, and neurotransmitter release in motor neurons

    Science.gov (United States)

    Mohamed, Habib A.; Mosier, Dennis R.; Zou, Ling L.; Siklos, Laszlo; Alexianu, Maria E.; Engelhardt, Jozsef I.; Beers, David R.; Le, Wei-dong; Appel, Stanley H.

    2002-01-01

    Receptors for the Fc portion of immunoglobulin G (IgG; FcgammaRs) facilitate IgG uptake by effector cells as well as cellular responses initiated by IgG binding. In earlier studies, we demonstrated that amyotrophic lateral sclerosis (ALS) patient IgG can be taken up by motor neuron terminals and transported retrogradely to the cell body and can alter the function of neuromuscular synapses, such as increasing intracellular calcium and spontaneous transmitter release from motor axon terminals after passive transfer. In the present study, we examined whether FcgammaR-mediated processes can contribute to these effects of ALS patient immunoglobulins. F(ab')(2) fragments (which lack the Fc portion) of ALS patient IgG were not taken up by motor axon terminals and were not retrogradely transported. Furthermore, in a genetically modified mouse lacking the gamma subunit of the FcR, the uptake of whole ALS IgG and its ability to enhance intracellular calcium and acetylcholine release were markedly attenuated. These data suggest that FcgammaRs appear to participate in IgG uptake into motor neurons as well as IgG-mediated increases in intracellular calcium and acetylcholine release from motor axon terminals. Copyright 2002 Wiley-Liss, Inc.

  17. Prophylactic immunoglobulin therapy in secondary immune deficiency

    DEFF Research Database (Denmark)

    Agostini, Carlo; Blau, Igor-Wolfgang; Kimby, Eva

    2016-01-01

    INTRODUCTION: In primary immunodeficiency (PID), immunoglobulin replacement therapy (IgRT) for infection prevention is well-established and supported by a wealth of clinical data. On the contrary, very little evidence-based data is available on the challenges surrounding the use of Ig......RT in secondary immune deficiencies (SID), and most published guidelines are mere extrapolations from the experience in PID. AREAS COVERED: In this article, four European experts provide their consolidated opinion on open questions surrounding the prophylactic use of IgRT in SID, based on their clinical...

  18. [Dermatomyositis and Panniculitis: the function of immunoglobulins].

    Science.gov (United States)

    Abdelhafidh, Nadia Ben; Toujeni, Sana; Kefi, Asma; Bousetta, Najeh; Sayhi, Sameh; Gharsallah, Imen; Othmani, Salah

    2016-01-01

    Panniculitis is an inflammatory disease of subcutaneous adipose tissue which is rarely associated with dermatomyositis. It can occur before, after or simultaneously with muscle damage. In most cases, the evolution of panniculitis and of other dermatomyositis affections is favorable with corticosteroids and/or immunosuppressants. We report the case of a 48 year-old patient who developed panniculitis lesions 2 months before having muscular signs. Skin involvement was resistant to corticosteroid treatment associated with immunosuppressants drugs. This led to the use of polyvalent immunoglobulin treatment improving both skin and muscle damage.

  19. Immunoglobulin for necrotising soft tissue infections (INSTINCT)

    DEFF Research Database (Denmark)

    Madsen, Martin Bruun; Lange, Theis; Hjortrup, Peter Buhl;

    2016-01-01

    INTRODUCTION: Necrotising soft tissue infections (NSTI) are aggressive infections that can result in severe disability or death. Intravenous polyspecific immunoglobulin G (IVIG) is used as supplementary treatment for patients with NSTIs. The level of evidence is very low, but suggests that IVIG may....... Secondary outcomes are: mortality; time to resolution of shock; bleeding; sequential organ failure assessment scores on days 1-7; use of renal-replacement therapy, mechanical ventilation and vasopressors; days alive and out of hospital; amputation; and severe adverse reactions. CONCLUSION: This study...

  20. Immunoglobulin Replacement Therapy: When You Need It -- and When You Don't

    Science.gov (United States)

    ... Videos Lists Search Patient Resources Immunoglobulin Replacement Therapy Immunoglobulin Replacement Therapy When you need it—and when ... enough germ-fighting antibodies. A treatment known as immunoglobulin replacement (IgG) therapy can be a lifesaver for ...

  1. The immunoglobulins of cold-blooded vertebrates.

    Science.gov (United States)

    Pettinello, Rita; Dooley, Helen

    2014-11-24

    Although lymphocyte-like cells secreting somatically-recombining receptors have been identified in the jawless fishes (hagfish and lamprey), the cartilaginous fishes (sharks, skates, rays and chimaera) are the most phylogenetically distant group relative to mammals in which bona fide immunoglobulins (Igs) have been found. Studies of the antibodies and humoral immune responses of cartilaginous fishes and other cold-blooded vertebrates (bony fishes, amphibians and reptiles) are not only revealing information about the emergence and roles of the different Ig heavy and light chain isotypes, but also the evolution of specialised adaptive features such as isotype switching, somatic hypermutation and affinity maturation. It is becoming increasingly apparent that while the adaptive immune response in these vertebrate lineages arose a long time ago, it is most definitely not primitive and has evolved to become complex and sophisticated. This review will summarise what is currently known about the immunoglobulins of cold-blooded vertebrates and highlight the differences, and commonalities, between these and more "conventional" mammalian species.

  2. Pasteurization of IgM-enriched Immunoglobulin

    Directory of Open Access Journals (Sweden)

    Kamran Mousavi Hosseini

    2004-06-01

    Full Text Available Human plasma proteins are important for therapy or prophylaxis of human diseases. Due to the preparation of human plasma proteins from human plasma pools and risk of contamination with human viruses, different viral reduction treatments such as: pasteurization, solvent/detergent, dry heat treatment, steam treatment, beta-propiolactone/UV and nanofiltration have been implemented. As pasteurization can be performed for liquid protein, this method (a 10-hour heat treatment of the aqueous solutions at 60°C was introduced into the manufacturing procedure of IgM-enriched immunoglobulin, to improve its safety further. The efficiency of this method for inactivation of viruses was evaluated by the use of Foot-and-Mouth Disease Virus (a non-enveloped virus and Infectious Bovine Rhinotracheitis (IBR Virus (a lipid-enveloped virus. Pasteurization inactivated Foot-and-Mouth Disease Virus by 7 log10 and for IBR Virus by 5log10. These findings show a significant added measure of virus safety associated with pasteurization of IgM-enriched immunoglobulin preparation.

  3. 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.

  4. The Immunoglobulins of Cold-Blooded Vertebrates

    Directory of Open Access Journals (Sweden)

    Rita Pettinello

    2014-11-01

    Full Text Available Although lymphocyte-like cells secreting somatically-recombining receptors have been identified in the jawless fishes (hagfish and lamprey, the cartilaginous fishes (sharks, skates, rays and chimaera are the most phylogenetically distant group relative to mammals in which bona fide immunoglobulins (Igs have been found. Studies of the antibodies and humoral immune responses of cartilaginous fishes and other cold-blooded vertebrates (bony fishes, amphibians and reptiles are not only revealing information about the emergence and roles of the different Ig heavy and light chain isotypes, but also the evolution of specialised adaptive features such as isotype switching, somatic hypermutation and affinity maturation. It is becoming increasingly apparent that while the adaptive immune response in these vertebrate lineages arose a long time ago, it is most definitely not primitive and has evolved to become complex and sophisticated. This review will summarise what is currently known about the immunoglobulins of cold-blooded vertebrates and highlight the differences, and commonalities, between these and more “conventional” mammalian species.

  5. Part-list Cuing and the Dynamics of False Recall

    OpenAIRE

    Kimball, Daniel R.; Bjork, Elizabeth L.; Bjork, Robert A.; Smith, Troy A.

    2008-01-01

    False recall of an unpresented critical word after studying its semantic associates can be reduced substantially if the strongest and earliest-studied associates are presented as part-list cues during testing (Kimball & Bjork, 2002). To disentangle episodic and semantic contributions to this decline in false recall, we factorially manipulated the cues' serial position and their strength of association to the critical word. Presenting cues comprising words that had been studied early in a list...

  6. [Use of intravenous humana immunoglobulin in rheumatic diseases].

    Science.gov (United States)

    Mussano, Eduardo D; Onetti, Laura B; Cadile, Isaac I; Onetti, Carlos M

    2012-01-01

    Preparations of intravenous immunoglobulin (IVIG) are used as treatment in different diseases such primary and secondary immunodeficiencies, autoimmune diseases, systemic inflammatory diseases, infectious diseases and allergic diseases among others. to present 13 of our cases with the use of IVIG in different rheumatic diseases. we retrospectively studied 13 patients (10 women and 3 men), mean age 29 years with different rheumatic diseases, that underwent conventional treatments without positive response. They received IVIG pulses, trying to improve or induce remission of their previous clinical situation. 6/13 patients met criteria for systemic lupus erythematosus (SLE), 2/13 had primary antiphospholipid syndrome (APL)one had polydermatomyositis (PDM), 1 juvenile arthritis, 1 panarteritis nodosa (cutaneous PAN), one Evans syndrome, and one with autoimmune uveitis. 7 of them had a positive response to therapy with IGEV evaluated by clinical and biochemical parameters. They remained with conventional treatments. One patient received a new IG EV pulse after 24 months, because of panniculitis reactivation. Clinical and biochemical response was poor in 4 of them, and 2 patients died. IVIg may be usefull in autoimmune rheumatic diseases when conventional therapies have failed. The therapeutic success is also limited. Only the 55 percent of our patients had a positive clinical response.

  7. 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

    To clarify the significance of immunoglobulin G autoantibody specific for the astrocyte water channel aquaporin-4 in cerebrospinal fluid, aquaporin-4-immunoglobulin G from a neuromyelitis optica patient was administered intrathecally to naïve mice, and the distribution and pathogenic impact...

  8. Subcutaneous versus intravenous immunoglobulin in multifocal motor neuropathy

    DEFF Research Database (Denmark)

    Harbo, T; Andersen, Henning; Hess, A

    2009-01-01

    Background and purpose: For treatment of multifocal motor neuropathy (MMN), we hypothesized that (i) infusion of equivalent dosages of subcutaneous immunoglobulin (SCIG) is as effective as intravenous immunoglobulin (IVIG) and that (ii) subcutaneous infusion at home is associated with a better...

  9. 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.

  10. Valence, Implicated Actor, and Children's Acquiescence to False Suggestions.

    Science.gov (United States)

    Cleveland, Kyndra C; Quas, Jodi A; Lyon, Thomas D

    2016-01-01

    Although adverse effects of suggestive interviewing on children's accuracy are well documented, it remains unclear as to whether these effects vary depending on the valence of and the actor implicated in suggestions. In this study, 124 3-8-year-olds participated in a classroom activity and were later questioned about positive and negative false details. The interviewer provided positive reinforcement when children acquiesced to suggestions and negative feedback when they did not. Following reinforcement or feedback, young children were comparably suggestible for positive and negative details. With age, resistance to suggestions about negative details emerged first, followed by resistance to suggestions about positive details. Across age, more negative feedback was required to induce acquiescence to negative than positive false details. Finally, children were less willing to acquiesce when they (versus the confederate) were implicated. Findings highlight the interactive effects of valence and children's age on their eyewitness performance in suggestive contexts.

  11. 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....

  12. Effect of hepatitis B immunisation in newborn infants of mothers positive for hepatitis B surface antigen

    DEFF Research Database (Denmark)

    Lee, Chuanfang; Gong, Yan; Brok, Jesper

    2006-01-01

    To evaluate the effects of hepatitis B vaccine and immunoglobulin in newborn infants of mothers positive for hepatitis B surface antigen.......To evaluate the effects of hepatitis B vaccine and immunoglobulin in newborn infants of mothers positive for hepatitis B surface antigen....

  13. Detection of orchitis and sacroiliitis due to brucellosis by 99mTc polyclonal human immunoglobulin scintigraphy.

    Science.gov (United States)

    Kadanali, Ayten; Uslu, Hatice; Bayraktar, Rezan; Varoglu, Erhan

    2012-07-01

    Here, we report 1 case of Brucella orchitis detected by 99mTc human immunoglobulin scintigraphy and confirmed by testicular ultrasound. A 29-year-old farmer was admitted to our hospital with fever, fatigue, arthralgia, and painful scrotal swelling that had appeared 12 days before admission. Clinically, right sacroiliitis was recorded through the Fabere test Unilateral sacroiliitis and orchitis were detected by 99mTc human immunoglobulin scintigraphy. Hypoechoic left testicular lesions and swelling of the concurrent epididymis were seen on a testicular ultrasound examination. Wright agglutination test and blood specimen culture for Brucella species were positive.

  14. Genomic structure and expression of immunoglobulins in Squamata.

    Science.gov (United States)

    Olivieri, David N; Garet, Elina; Estevez, Olivia; Sánchez-Espinel, Christian; Gambón-Deza, Francisco

    2016-04-01

    The Squamata order represents a major evolutionary reptile lineage, yet the structure and expression of immunoglobulins in this order has been scarcely studied in detail. From the genome sequences of four Squamata species (Gekko japonicus, Ophisaurus gracilis, Pogona vitticeps and Ophiophagus hannah) and RNA-seq datasets from 18 other Squamata species, we identified the immunoglobulins present in these animals as well as the tissues in which they are found. All Squamata have at least three immunoglobulin classes; namely, the immunoglobulins M, D, and Y. Unlike mammals, however, we provide evidence that some Squamata lineages possess more than one Cμ gene which is located downstream from the Cδ gene. The existence of two evolutionary lineages of immunoglobulin Y is shown. Additionally, it is demonstrated that while all Squamata species possess the λ light chain, only Iguanidae species possess the κ light chain.

  15. False confessions: causes, consequences, and implications.

    Science.gov (United States)

    Leo, Richard A

    2009-01-01

    In the past two decades, hundreds of convicted prisoners have been exonerated by DNA and non-DNA evidence, revealing that police-induced false confessions are a leading cause of wrongful conviction of the innocent. In this article, empirical research on the causes and correlates of false confessions is reviewed. After a description of the three sequential processes that are responsible for the elicitation of false confessions--misclassification, coercion, and contamination--the three psychologically distinct types of false confession (voluntary, compliant, and persuaded) are discussed along with the consequences of introducing false-confession evidence in the criminal justice system. The article concludes with a brief discussion of the implications of empirical research for reducing the number of false confessions and improving the accuracy of confession evidence that is introduced against a defendant at trial.

  16. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.

    Science.gov (United States)

    2010-04-01

    ... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...

  17. True hyponatremia secondary to intravenous immunoglobulin.

    Science.gov (United States)

    Nguyen, Minhtri K; Rastogi, Anjay; Kurtz, Ira

    2006-06-01

    Hyponatremia is characterized as either "true hyponatremia," which represents a decrease in the Na(+) concentration in the water phase of plasma, or "pseudohyponatremia," which is due to an increased percentage of protein or lipid in plasma, with a normal plasma water Na(+) concentration ([Na(+)]). Pseudohyponatremia is a known complication of intravenous immunoglobulin (IVIG). Because IVIG has been reported to result in post-infusional hyperproteinemia, IVIG-induced hyponatremia has been attributed to pseudohyponatremia. In this case report, we demonstrate that IVIG therapy can result in true hyponatremia, resulting from sucrose-induced translocation of water from the intracellular compartment (ICF) to the extracellular compartment (ECF), as well as the infusion of a large volume of dilute fluid, in patients with an underlying defect in urinary free water excretion.

  18. 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.

  19. Rheumatoid factors, B cells and immunoglobulin genes.

    Science.gov (United States)

    Jefferis, R

    1995-04-01

    The paradigm of self, non-self discrimination in the immune system is under review as autoreactive B or T cells are increasingly delineated within normal individuals. The products of autoreactive B cells are, mostly, polyspecific IgM antibodies of low affinity. These 'natural' antibodies include rheumatoid factors (RF) encoded by unmutated germline immunoglobulin genes. In rheumatoid arthritis (RA) the RF may be of the IgM, IgG or IgA isotype, show evidence of somatic mutation and have increased affinity; consistent with maturation of an antigen driven immune response. This response could be initiated or driven by an auto-immunogenic form of IgG or an exogenous cross-reactive antigen. Changes in galactosylation of IgG have been reported to be a valuable diagnostic and prognostic indicator in RA. Speculation that these changes may precipitate some of the disease processes is critically reviewed.

  20. 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.

  1. Characterization of immunoglobulin variable regions of two human pathogenic monoclonal cryocrystalglobulins.

    Science.gov (United States)

    Navazza, Valentina; Gabba, Silvia; Alfieri, Andrea; Giorgetti, Sofia; Marchese, Loredana; Palladini, Giovanni; Mattevi, Andrea; Ascari, Edoardo; Caporali, Roberto; Montecucco, Carlomaurizio; Merlini, Giampaolo; Perfetti, Vittorio

    2008-03-01

    Cold-precipitating monoclonal immunoglobulins can rarely aggregate in form of crystals (cryocrystalglobulins) and cause serious clinical manifestations. The structural basis underlying this phenomenon remains to be defined. This study was undertaken to provide the first characterization of the heavy (VH) and light chain (VL) variable regions of two human pathogenic cryocrystalglobulins. The immunoglobulins used different heavy and light chain constant regions and germline gene fragments, underwent high degrees of somatic hypermutation, and showed distributions of replacement and silent nucleotide changes suggestive of antigenic selection. Primary sequences analyses and computer-generated modeling identified a positive charge and the introduction of unusual hydrophobic residues in exposed areas of VH and VL. In particular, a rare replacement of a polar residue with proline is shared at the beginning of the VH complementarity-determining region 2, and this residue might be involved in intermolecular contacts.

  2. Constructing rich false memories of committing crime.

    Science.gov (United States)

    Shaw, Julia; Porter, Stephen

    2015-03-01

    Memory researchers long have speculated that certain tactics may lead people to recall crimes that never occurred, and thus could potentially lead to false confessions. This is the first study to provide evidence suggesting that full episodic false memories of committing crime can be generated in a controlled experimental setting. With suggestive memory-retrieval techniques, participants were induced to generate criminal and noncriminal emotional false memories, and we compared these false memories with true memories of emotional events. After three interviews, 70% of participants were classified as having false memories of committing a crime (theft, assault, or assault with a weapon) that led to police contact in early adolescence and volunteered a detailed false account. These reported false memories of crime were similar to false memories of noncriminal events and to true memory accounts, having the same kinds of complex descriptive and multisensory components. It appears that in the context of a highly suggestive interview, people can quite readily generate rich false memories of committing crime.

  3. Use of human intravenous immunoglobulin in lower motor neuron syndromes

    Science.gov (United States)

    Ellis, C; Leary, S; Payan, J; Shaw, C; Hu, M; O'Brien, M; Leigh, P

    1999-01-01

    OBJECTIVE—To determine whether patients with the clinical phenotype of multifocal motor neuropathy but without the electrophysiological criteria for conduction block would respond to intravenous immunoglobulin (IVIg).
METHODS—Ten patients were selected with a slowly progressive, asymmetric, lower motor neuron disorder, and were treated prospectively with IVIg at a dose of 2g/kg over 5 days. All subjects had neurophysiological testing to look for evidence of conduction block before treatment. Muscle strength was assessed by MRC grades and hand held myometry, measuring pinch and grip strength. A 20% increase in both pinch and grip myometry was considered a positive response.
RESULTS—In no patient was conduction block detected. Four of the 10 patients showed a positive response to IVIg, with the best response occurring in two patients who presented with weakness but without severe muscle wasting. Three of the four responders have continued to receive IVIg for a mean period of 17 months (range 15-24 months), with continued effect. The response to IVIg was not related to the presence of anti-GM1 antiganglioside antibodies, but responders had a selective pattern of muscle weakness and normal (>90% predicted) vital capacity.
CONCLUSION—The findings suggest that a course of IVIg should be considered in patients with the clinical phenotype of multifocal motor neuropathy but without neurophysiological evidence of conduction block.

 PMID:10369816

  4. Gene conversion in human rearranged immunoglobulin genes.

    Science.gov (United States)

    Darlow, John M; Stott, David I

    2006-07-01

    Over the past 20 years, many DNA sequences have been published suggesting that all or part of the V(H) segment of a rearranged immunoglobulin gene may be replaced in vivo. Two different mechanisms appear to be operating. One of these is very similar to primary V(D)J recombination, involving the RAG proteins acting upon recombination signal sequences, and this has recently been proven to occur. Other sequences, many of which show partial V(H) replacements with no addition of untemplated nucleotides at the V(H)-V(H) joint, have been proposed to occur by an unusual RAG-mediated recombination with the formation of hybrid (coding-to-signal) joints. These appear to occur in cells already undergoing somatic hypermutation in which, some authors are convinced, RAG genes are silenced. We recently proposed that the latter type of V(H) replacement might occur by homologous recombination initiated by the activity of AID (activation-induced cytidine deaminase), which is essential for somatic hypermutation and gene conversion. The latter has been observed in other species, but not in human Ig genes, so far. In this paper, we present a new analysis of sequences published as examples of the second type of rearrangement. This not only shows that AID recognition motifs occur in recombination regions but also that some sequences show replacement of central sections by a sequence from another gene, similar to gene conversion in the immunoglobulin genes of other species. These observations support the proposal that this type of rearrangement is likely to be AID-mediated rather than RAG-mediated and is consistent with gene conversion.

  5. Amniotic and allantoic fluids from experimentally infected sheep contain immunoglobulin specific for Chlamydophila abortus.

    Science.gov (United States)

    Marques, Patricia X; O'Donovan, James; Souda, Puneet; Gutierrez, Jorge; Williams, Erin J; Worrall, Sheila; McElroy, Maire; Proctor, Aisling; Brady, Colm; Sammin, Donal; Basset, Hugh; Whitelegge, Julian P; Markey, Bryan K; Nally, Jarlath E

    2011-03-15

    Chlamydophila abortus, the aetiological agent of enzootic abortion of ewes (EAE), replicates in trophoblast cells leading to their destruction and dissemination of the bacterium to foetal organs. To further understand the pathogenesis of EAE, amniotic and allantoic fluids were collected from experimentally infected pregnant ewes at 30 (7 samples from each fluid), 35 (8 samples from each fluid), 40 (10 samples from each fluid) and 43 (6 amniotic fluids and 7 allantoic fluids) days post-infection to determine pathogen numbers and other markers of infection. Whilst experimentally infected ewes had characteristic placental lesions, only two amniotic and seven allantoic fluid samples were positive for C. abortus by real-time PCR. In contrast, all amniotic and allantoic fluids were positive for immunoglobulin. Immunoglobulins were generally detected earlier in allantoic fluid than in amniotic fluid and the numbers of samples containing immunoglobulins increased as infection progressed. IgG in amniotic and allantoic fluids was shown to be specific for C. abortus, and reacted with the major outer membrane proteins, polymorphic outer membrane protein and macrophage infectivity potentiator protein. A comparison of two-dimensional immunoblots using purified IgG from the allantoic fluid, amniotic fluid, ewe serum and foetal serum of a C. abortus infected animal at 40 days post infection indicated a pattern of reactivity intermediate between that of the ewe serum and the foetal serum. Results suggest that a maternal source of immunoglobulin is predominant at 30 days post-infection but that foetal derived antibodies may be contributed at a later stage.

  6. Publication bias and the canonization of false facts.

    Science.gov (United States)

    Nissen, Silas Boye; Magidson, Tali; Gross, Kevin; Bergstrom, Carl T

    2016-12-20

    Science is facing a "replication crisis" in which many experimental findings cannot be replicated and are likely to be false. Does this imply that many scientific facts are false as well? To find out, we explore the process by which a claim becomes fact. We model the community's confidence in a claim as a Markov process with successive published results shifting the degree of belief. Publication bias in favor of positive findings influences the distribution of published results. We find that unless a sufficient fraction of negative results are published, false claims frequently can become canonized as fact. Data-dredging, p-hacking, and similar behaviors exacerbate the problem. Should negative results become easier to publish as a claim approaches acceptance as a fact, however, true and false claims would be more readily distinguished. To the degree that the model reflects the real world, there may be serious concerns about the validity of purported facts in some disciplines.

  7. Part-list cuing and the dynamics of false recall.

    Science.gov (United States)

    Kimbal, Daniel R; Bjork, Elizabeth L; Bjork, Robert A; Smith, Troy A

    2008-04-01

    False recall of an unpresented critical word after studying its semantic associates can be reduced substantially if the strongest and earliest-studied associates are presented as part-list cues during testing (Kimball & Bjork, 2002). To disentangle episodic and semantic contributions to this decline in false recall, we factorially manipulated the cues' serial position and their strength of association to the critical word. Presenting cues comprising words that had been studied early in a list produced a greater reduction in false recall than did presenting words studied late in the list, independent of the cues' associative strength, but only when recall of the cues themselves was prohibited. When recall of the cues was permitted, neither early-studied nor late-studied cues decreased false recall reliably, relative to uncued lists. The findings suggest that critical words and early-studied words share a similar fate during recall, owing to selective episodic strengthening of their associations during study.

  8. 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 i

  9. 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 i

  10. 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…

  11. 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…

  12. How Does Distinctive Processing Reduce False Recall?

    Science.gov (United States)

    Hunt, R. Reed; Smith, Rebekah E.; Dunlap, Kathryn R.

    2011-01-01

    False memories arising from associatively related lists are a robust phenomenon that resists many efforts to prevent it. However, a few variables have been shown to reduce this form of false memory. Explanations for how the reduction is accomplished have focused on either output monitoring processes or constraints on access, but neither idea alone…

  13. 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.

  14. 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.

  15. 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…

  16. 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…

  17. 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…

  18. Belief and sign, true and false: the unique of false belief reasoning.

    Science.gov (United States)

    Zhang, Ting; Zhang, Qin; Li, Yiyuan; Long, Changquan; Li, Hong

    2013-11-01

    For a long time, a controversy has been proposed that whether the process of theory of mind is a result of domain-specific or domain-general changes (Wellman in The handbook of childhood cognitive development. Blackwell Publication, New Jersey, 2011). This event-related potential study explored the neural time course of domain-general and domain-specific components in belief reasoning. Fourteen participants completed location transfer false belief (FB), true belief (TB), false sign (FS) and true sign (TS) tasks, in which two pictures told a story related to a dog that ran from a green into a red box. In the TB and FB tasks, a boy saw or did not see the transfer of the dog, respectively. In the FS and TS tasks, an arrow that pointed to the green box either altered its direction to the red box or did not alter following the transfer of the dog. Participants then inferred where the boy thought of, or the arrow indicated the location of the dog. FB and TB reasoning elicited lower N2 amplitudes than FS and TS reasoning, which is associated with domain-general components, the detection, and classification. The late slow wave (LSW) for FB was more positive at frontal, central, and parietal sites than FS because of the domain-specific component involved in FB reasoning. However, the LSW was less positive for TB than for FB but did not differ from the TS condition, which implies that mental representation might not be involved in TB reasoning.

  19. Characterisation of an ELISA detecting immunoglobulin G to Mycobacterium avium subsp. paratuberculosis in bovine colostrum

    DEFF Research Database (Denmark)

    Zervens, Lisa Marie-Louise; Nielsen, Søren Saxmose; Jungersen, Gregers

    2013-01-01

    Although colostrum has been used to detect specific immunoglobulin (Ig) G to Mycobacterium avium subsp. paratuberculosis (MAP) in cattle, confounding, non-specific reactions can be a problem. The objectives of this study were to determine the proportion of non-specific ELISA reactions in samples...... of colostrum taken between 0 and 4days-in-milk (DIM), and to assess the probability of an animal testing positive for MAP specific IgG over this time-period. Non-specific reactions were found in 3/365 (0.8%) of samples. The odds of an animal testing positive on day of calving were 130 times higher than at 4...

  20. Viscoelastic properties of the false vocal fold

    Science.gov (United States)

    Chan, Roger W.

    2004-05-01

    The biomechanical properties of vocal fold tissues have been the focus of many previous studies, as vocal fold viscoelasticity critically dictates the acoustics and biomechanics of phonation. However, not much is known about the viscoelastic response of the ventricular fold or false vocal fold. It has been shown both clinically and in computer simulations that the false vocal fold may contribute significantly to the aerodynamics and sound generation processes of human voice production, with or without flow-induced oscillation of the false fold. To better understand the potential role of the false fold in phonation, this paper reports some preliminary measurements on the linear and nonlinear viscoelastic behavior of false vocal fold tissues. Linear viscoelastic shear properties of human false fold tissue samples were measured by a high-frequency controlled-strain rheometer as a function of frequency, and passive uniaxial tensile stress-strain response of the tissue samples was measured by a muscle lever system as a function of strain and loading rate. Elastic moduli (Young's modulus and shear modulus) of the false fold tissues were calculated from the measured data. [Work supported by NIH.

  1. Simultaneous administration of {sup 111}In-human immunoglobulin and {sup 99m}Tc-HMPAO labelled leucocytes in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Mairal, L. [Dept. of Nuclear Medicine, CSUB, Hospital Princeps d`Espanya, Barcelona (Spain); Lima, P.A. de [Bolsista do Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (Brazil); Martin-Comin, J. [Dept. of Nuclear Medicine, CSUB, Hospital Princeps d`Espanya, Barcelona (Spain); Baliellas, C. [Dept. of Gastroenterology, CSUB, Hospital Princeps d`Espanya, Barcelona (Spain); Xiol, X. [Dept. of Gastroenterology, CSUB, Hospital Princeps d`Espanya, Barcelona (Spain); Roca, M. [Dept. of Nuclear Medicine, CSUB, Hospital Princeps d`Espanya, Barcelona (Spain); Ricart, Y. [Dept. of Nuclear Medicine, CSUB, Hospital Princeps d`Espanya, Barcelona (Spain); Ramos, M. [Dept. of Nuclear Medicine, CSUB, Hospital Princeps d`Espanya, Barcelona (Spain)

    1995-07-01

    Technetium-99m hexamethylpropylene amine oxime (HMPAO) labelled leucocytes and indium-111 polyclonal immunoglobulin (IgG) were simultaneously injected into a group of 27 patients routinely referred for the investigation of inflammatory bowel disease (IBD). Ten-minute anterior abdomen and tail on detector views were obtained at 30 min, 4 h and 24 h p.i. of both tracers. The diagnosis of IBD was obtained in all cases by endoscopy with biopsy and/or surgery. Images were blindly evaluated by two experienced observers who only knew of the clinical suspicion of IBD. IBS was confirmed in 20 patients (12 with Crohn`s disease and eight with ulcerative colitis). Sensitivity, specificity and accuracy were 100%, 85% and 96% respectively for labelled leucocytes and 70%, 85% and 74% for IgG. Both IgG and leucocyte scans were normal in six out of seven patients in whom a diagnosis of IBD was excluded; the remaining patient, with ischaemic colitis, was falsely positive with both agents. As far as disease extension is concerned, the IgG study localized 27 diseased segments, whereas 49 were seen with the leucocyte study. Eighty-four segments were normal and 25 showed tracer uptake with both agents. Twenty-four were positive only with the leucocyte study and two were positive only with the IgG study. Agreement between the agents was 80.7%. (orig./UG)

  2. Intravenous immunoglobulin in symptomatic and asymptomatic children with perinatal HIV infection.

    Science.gov (United States)

    Olopoenia, L; Young, M; White, D; Barnes, S; Rahbar, F; Fomufod, A

    1997-08-01

    One hundred thirty-five children born to human immunodeficiency virus (HIV)-infected mothers were selected randomly to receive immunoglobulin (Gamimune-N, Miles Pharmaceutical Co) 200 mg/kg monthly for 1 year. All patients were seropositive by ELISA and Western blot at birth. At the time of the study, 15 symptomatic (P2) and 57 asymptomatic (P1) patients with evidence of viral infection (positive HIV culture or P24 antigen) received the immunoglobulin. Sixty-three indeterminate (PO) patients with no evidence of infection served as the control. Mean age for infants in group P2 was 32 months, 26 months for group P1, and 11 months for group PO. Significant reduction in the frequency of bacterial infections (ie, otitis media, upper respiratory tract infections, urinary tract infections, and acute gastroenteritis) was seen in the symptomatic group compared with both the asymptomatic and the control groups. Growth as measured by weight and height > 50th percentile was also markedly better in the symptomatic group than either asymptomatic or control patients. There was no significant difference in head circumference in all three groups. These results indicate that monthly intravenous immunoglobulin infusion (IVIG) appears to be beneficial to both symptomatic and asymptomatic HIV patients in reducing the frequency of bacterial infection and also enhancement of the immune response. However, symptomatic patients responded much better than the asymptomatic patients.

  3. 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.

  4. Correlation of Immunoglobulin G Expression and Histological Subtype and Stage in Breast Cancer

    Science.gov (United States)

    Chen, Zhengshan; Yi, Weining; McNutt, Michael A.; Wang, Yun; Korteweg, Christine; Gu, Jiang

    2013-01-01

    Introduction Recently, growing evidence indicates that immunoglobulins (Igs) are not only produced by mature B lymphocytes or plasma cells, but also by various normal cells types at immune privileged sites and neoplasm, including breast cancer. However, the association of breast cancer derived IgG with genesis and development of the disease has not yet been established. Methods In this study we examined the expression of IgG in 186 breast cancers, 20 benign breast lesions and 30 normal breast tissues. Both immunohistochemistry with antibodies to Igκ (immunoglobulin G κ light chain) and Igγ (immunoglobulin G heavy chain) and in situ hybridization with an antisense probe to IgG1 heavy chain constant region gene were performed. Various clinicopathological features were also analyzed. Results We found that IgG is specifically expressed in human breast cancer cells. Both infiltrating ductal carcinoma and infiltrating lobular carcinoma had significantly greater numbers of Igκ and Igγ positive cancer cells as compared with medullary carcinoma, carcinoma in situ, and benign lesions (all pbreast cancer histological subtypes (pbreast cancer cells is correlated with malignancy and AJCC stages of the cancers. This suggests that breast cancer derived IgG may be associated with genesis, development and prognosis of the cancer. PMID:23554916

  5. Rabbit anti-rabies immunoglobulins production and evaluation.

    Science.gov (United States)

    Liu, Xinjian; Liu, Qiongqiong; Feng, Xiaomin; Tang, Qi; Wang, Zhongcan; Li, Suqing; Feng, Zhenqing; Zhu, Jin; Guan, Xiaohong

    2011-04-01

    Due to the disadvantages of human and equine rabies immunoglobulin, it is necessary to develop a substitute for HRIG and ERIG, especially for those people living in the developing countries. Because of higher affinity and lower immunogenicity of rabbit's immunoglobulins, anti-rabies immunoglobulins specific to rabies virus were produced in rabbits as a bioreactor, and had been characterized by ELISA, affinity assay, immunofluorescence assay (IFA), immunocytochemistry, rapid fluorescent focus inhibition test (RFFIT). ELISA, affinity assay and IFA showed that rabbit RIG (RRIG) bound specifically to rabies virions. RFFIT result showed that RRIG has neutralization activity. This result was confirmed in vivo in a Kunming mouse challenge model and the protection rate of the treatment with RRIG was higher (25%) than that offered by HRIG when mice were challenged with a lethal RV dose. Our results demonstrate that RRIG is safe and efficacious as a candidate drug to replace rabies immunoglobulin in post-exposure prophylaxis.

  6. Prognostic significance of serum immunoglobulin pareprotein in chronic lymphocytic leukemia

    Institute of Scientific and Technical Information of China (English)

    杨舒

    2012-01-01

    Objective To investigate the incidence of serum immunoglobulin (Ig) paraprotein in chronic lymphocytic leukemia(CLL) ,and to explore its clinical associated laboratory features and prognostic implication. Methods Serum protein electrophoresis and immunofixation

  7. 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

  8. 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 lab

  9. Estimation of major immunoglobulins in smokers and gutkha chewers

    Directory of Open Access Journals (Sweden)

    Ketankumar Jayantilal Prajapati

    2016-01-01

    Conclusion: Higher major immunoglobulins levels in present study among the study groups indicate the use of immunoprofile estimation in etiology and pathogenesis and would prove a great asset in the proper assessment of the lesions.

  10. The molecular basis of somatic hypermutation of immunoglobulin genes.

    Science.gov (United States)

    Storb, U

    1996-04-01

    Somatic hypermutation amplifies the variable region repertoire of immunoglobulin genes. Recent experimental evidence has thrown light on various molecular models of somatic hypermutation. A link between somatic hypermutation and transcription coupled DNA repair is shaping up.

  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 lab

  12. Self‑perceived oral health and whole salivary immunoglobulin G ...

    African Journals Online (AJOL)

    2015-04-05

    Apr 5, 2015 ... immunoglobulin G levels in habitual gutka‑chewers and nonchewers ... respondents with periodontal disease (PD) are unaware of their oral ..... virus and oral lesions in gutka eating subjects in Karachi. J Coll Physicians Surg.

  13. Immunoglobulin G response in patients with Campylobacter concisus diarrhea.

    Science.gov (United States)

    Nielsen, Hans Linde; Kaakoush, Nadeem O; Mitchell, Hazel M; Nielsen, Henrik

    2016-02-01

    Limited information is available on the systemic immunoglobulin response in patients infected with the emerging pathogen Campylobacter concisus. The aim of the present study was to detect anti-C. concisus antibodies in serum of 88 patients with C. concisus gastroenteritis. Specific IgG antibodies to C. concisus were measured in serum using an in-house enzyme-linked immunosorbent assay, and pooled donor serum was used as a control. The mean optical density was 0.135 (SEM: 0.020) for the 88 adult patients and 0.100 (SEM: 0.011) in controls. When using an optical density value equal to the mean +3 SEM for the control serum, 22 (25%) C. concisus-positive patients had increased IgG antibodies. Patients with high IgG levels more often reported headache, and they had a trend toward more mucus in stools, whereas IgG levels were unrelated to age, duration of diarrhea, number of stools per day, and weight loss. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Comparison of somatic mutation frequency among immunoglobulin genes.

    Science.gov (United States)

    Motoyama, N; Miwa, T; Suzuki, Y; Okada, H; Azuma, T

    1994-02-01

    We analyzed the frequency of somatic mutation in immunoglobulin genes from hybridomas that secrete anti-(4-hydroxy-3-nitrophenyl)acetyl (NP) monoclonal antibodies. A high frequency of mutation (3.3-4.4%) was observed in both the rearranged VH186.2 and V lambda 1 genes, indicating that somatic mutation occurs with similar frequency in these genes in spite of the absence of an intron enhancer in lambda 1 chain genes. In contrast to the high frequency in J-C introns, only two nucleotide substitutions occurred at positions -462 and -555 in the 5' noncoding region in one of the lambda 1-chain genes and in none of the other three so far studied. Since a similar low frequency of somatic mutation was observed in the 5' noncoding region of inactive lambda 2-chain genes rendered inactive because of incorrect rearrangement, this region may not be a target or alternatively, may be protected from the mutator system. We observed a low frequency of nucleotide substitution in unrearranged V lambda 1 genes (approximately 1/15 that of rearranged genes). Together with previous results (Azuma T., N. Motoyama, L. Fields, and D. Loh, 1993. Int. Immunol. 5:121), these findings suggest that the 5' noncoding region, which contains the promoter element, provides a signal for the somatic mutator system and that rearrangement, which brings the promoter into close proximity to the enhancer element, should increase mutation efficiency.

  15. Anti-sulfatide/galactocerebroside antibodies in immunoglobulin M paraproteinemic neuropathies.

    Science.gov (United States)

    Boso, F; Ruggero, S; Giannotta, C; Benedetti, L; Marfia, G A; Ermani, M; Campagnolo, M; Salvalaggio, A; Gallia, F; De Michelis, C; Visentin, A; Bianco, M; Ruiz, M; Mataluni, G; Nobile-Orazio, E; Briani, C

    2017-08-07

    Anti-sulfatide antibodies have been observed in heterogeneous neuropathies and their clinical relevance is still controversial. Whether the combination of sulfatide with galactocerebroside would increase sensitivity or specificity of enzyme-linked immunosorbent assay testing compared to sulfatide alone was assessed. Immunoglobulin M (IgM) antibodies to sulfatides, galactocerebroside and combined sulfatide and galactocerebroside (Sulf/GalC) were measured in 229 neuropathy patients, including 73 with IgM paraproteinemic neuropathy [62 with anti-myelin-associated glycoprotein (anti-MAG) antibody] and 156 with other neuropathies. Results from 27 patients with IgM monoclonal gammopathy without neuropathy and 28 healthy subjects served as control. Thirty-three patients showed increased titers of anti-sulfatide antibodies, 28 of whom had an IgM paraproteinemic neuropathy (P neuropathies), who had no reactivity to the individual glycolipids. Amongst the 11 subjects with IgM paraproteinemic neuropathy who were negative for anti-MAG antibodies, only two were reactive to sulfatide, whilst six (55%) were found to be positive when tested against the combination of sulfatide and galactocerebroside. Testing for both sulfatide and galactocerebroside in IgM paraproteinemic neuropathies seems to increase the sensitivity compared to anti-sulfatide antibodies alone (49% and 39%, respectively, with a slightly reduced specificity, from 97% to 87%), helping the characterization of otherwise undefined neuropathy that could benefit from immunomodulatory therapy. © 2017 EAN.

  16. Russell body duodenitis with immunoglobulin kappa lightchain restriction

    Institute of Scientific and Technical Information of China (English)

    William R Munday; Lucy Harn Kapur; Mina Xu; Xuchen Zhang

    2015-01-01

    Russell bodies are eosinophilic intracytoplasmicglobules which are likely the result of disturbedsecretion of immunoglobulins that accumulate withinthe plasma cell. Russell body collections have beenidentified within the stomach, known as Russellbody gastritis. Similar lesions within the duodenumare referred to as Russell body duodenitis, whichis rare. Several Russell body gastritis case reportsare associated with Helicobacter pylori . However,the etiology of Russell body duodenitis remainsunclear. Here we report the first case of Russell bodyduodenitis with immunoglobulin light chain restrictionin a background of peptic duodenitis.

  17. Efficacy and tolerability of 16% subcutaneous immunoglobulin compared with 20% subcutaneous immunoglobulin in primary antibody deficiency.

    Science.gov (United States)

    Niebur, H B; Duff, C M; Shear, G F; Nguyen, D; Alberdi, T K; Dorsey, M J; Sleasman, J W

    2015-09-01

    Multiple subcutaneous immunoglobulin (SCIG) products are available to treat primary antibody deficiency (PAD). The efficacy and tolerability of 16% SCIG (Vivaglobin(®) ) was compared with 20% SCIG (Hizentra(®) ) in PAD subjects. The study was a prospective, single-centre, open-label study of PAD subjects transitioning Vivaglobin to equivalent Hizentra doses, rounded to the nearest vial size. Comparisons included immunoglobulin (Ig)G levels; tetanus, varicella and Streptococcus pneumoniae titres; adverse events (AEs), annual infection rate and quality of life during 8 weeks of Vivaglobin and 24 weeks of Hizentra. Thirty-two subjects (aged 2-75 years) participated. Rounding to the nearest Hizentra vial size resulted in a 12·8% (± 2·9%) increase in SCIG dose. Median immunoglobulin (Ig)G level following 8 weeks of Vivaglobin was similar to 24 weeks of Hizentra (1050 versus 1035 mg/dl, respectively; P = 0·77). Both products had similar protective titres to tetanus, varicella and serotypes of S. pneumoniae, which were variable but well above protective levels. After 12 weeks of Hizentra, subjects reported fewer local site reactions compared with Vivaglobin. Switching products resulted in increased systemic AEs in some subjects but, overall, not significantly higher than during Vivaglobin treatment. Average infusion time decreased from 104·7 min (3·3 sites) with Vivaglobin to 70·7 min (2·2 sites) with Hizentra (P = 0·0005). Acute serious bacterial infections were similar. Treatment satisfaction was superior with Hizentra. Hizentra and Vivaglobin have similar pharmacokinetics and efficacy. Although transition to a different SCIG product initially increased AEs, Hizentra is well tolerated and can be infused more rapidly and with fewer sites compared to Vivaglobin.

  18. The role of articulatory suppression in immediate false recognition.

    Science.gov (United States)

    Macé, Anne-Laure; Caza, Nicole

    2011-11-01

    False memory for critical lures has been widely documented in long-term memory using the Deese/Roediger-McDermott paradigm. Recent evidence suggests that false memory effects can also be found in short-term memory (STM), supporting models that assume a strong relationship between short-term and long-term memory processes. However, no study has examined the role of articulatory suppression on immediate false memory, even though phono-articulatory factors are critically involved in STM performance and are an intrinsic part of all STM accounts. The current study proposes a novel paradigm to assess false memory effects in a STM task under both silent and articulatory suppression conditions. Using immediate serial recognition, in which participants had to judge whether two successive mixed lists of six associated and non-associated words were matched, we examined true recognition of matching lists and false recognition of mismatching lists comprising a critical lure or unrelated distractor in two experiments. Results from both experiments indicated reduced true recognition of matching lists and greater false serial recognition of mismatching lists comprising a critical lure under articulatory suppression relative to silence. These findings provide further support for some current models of verbal short-term memory, which posit a strong relationship between short-term and long-term memory processes.

  19. Reverse-engineering a detector with false alarms

    Science.gov (United States)

    Craver, Scott; Yu, Jun

    2007-02-01

    Inspired by results from the Break Our Watermarking System (BOWS) contest, we explored techniques to reverse-engineer watermarking algorithms via oracle attacks. We exploit a principle called "superrobustness," which allows a watermarking algorithm to be characterized by its resistance to specific distortions. The generic application of this principle to an oracle attack seeks to find a severe false alarm, or a point on the watermark detection region as far as possible from the watermarked image. For specific types of detection regions, these severe false positives can leak information about the feature space as well as detector parameters. We explore the specific case of detectors using normalized correlation, or correlation coefficient.

  20. Concurrent Drug-Induced Linear Immunoglobulin A Dermatosis and Immunoglobulin A Nephropathy

    OpenAIRE

    Kim, Ji Seok; Choi, Misoo; Nam, Chan Hee; Kim, Jee Young; Park, Byung Cheol; Kim, Myung Hwa; Hong, Seung Phil

    2015-01-01

    Diseases associated with immunoglobulin A (IgA) antibody include linear IgA dermatosis, IgA nephropathy, Celiac disease, Henoch-Schönlein purpura, etc. Although usually idiopathic, IgA antibody is occasionally induced by drugs (e.g., vancomycin, carbamazepine, ceftriaxone, and cyclosporine), malignancies, infections, and other causes. So far, only a few cases of IgA bullous dermatosis coexisting with IgA nephropathy have been reported. A 64-year-old female receiving intravenous ceftriaxone an...