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Sample records for false-positive study due

  1. 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...

  2. 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.

  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. 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

  5. False Positive FDG PET/CT of Recurrent Testicular Tumour Due to Orchitis

    Directory of Open Access Journals (Sweden)

    Robert Mansberg

    2014-02-01

    Full Text Available A 47-year-old male with a history of right sided orchidectomy for stage 1 seminoma 6 months previously, was referred for a FDG PETCT scan for restaging of testicular cancer having experiencing left testicular discomfort. Abnormally increased glyoclytic metabolism of the left testis and the inferior scrotal sac was demonstrated on the initial FDG PET-CT study. Subsequent ultrasound showed subtle heterogeneous echotexture with mild hypervascularity and no focal lesion was identified. The patient was subsequently treated with antibiotics for a presumed diagnosis of orchitis. A progress FDG PET-CT study 2 months later confirmed the complete resolution of the increased glycolytic metabolism in the left testis and the inferior scrotal sac.

  6. [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.

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

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    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

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. [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.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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

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

    Science.gov (United States)

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

    2017-03-16

    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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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....

  6. 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.

  7. 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

  8. 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 ...

  9. 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.

  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. 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.

  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. Improved first-trimester Down syndrome screening performance by lowering the false-positive rate: a prospective study of 9941 low-risk women

    DEFF Research Database (Denmark)

    Wøjdemann, K R; Shalmi, A C; Christiansen, M

    2005-01-01

    OBJECTIVE: To determine the performance of screening for Down syndrome (DS) and other major chromosomal abnormalities using nuchal translucency (NT), free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in a prospective study of a non...

  14. 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.

  15. 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.

  16. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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...

  8. 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

  9. 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

  10. 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.

  11. 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...

  12. 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…

  13. 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…

  14. 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.

  15. 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.

  16. 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

  17. 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.

  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. 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...

  20. 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.

  1. 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....

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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.

  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. "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.

  10. "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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. False positive 18F-FDG PET/CT due to inflamed concha bullosa.

    NARCIS (Netherlands)

    Arens, A.I.J.; Verbist, B.M.; Hendrickx, B.W.; Geus-Oei, L.F. de; Oyen, W.J.G.

    2012-01-01

    A 62-year-old woman with a history of breast cancer was referred for an (18)F-FDG PET/CT scan. She had an active upper respiratory infection at the time of examination. An FDG avid (SUV(max) = 7.7) middle turbinate was identified, correlating with an inflamed concha bullosa. A short review of concha

  1. False Positive F-18 FDG PET/CT of Skeletal Metastasis Due to Solitary Eosinophilic Granuloma

    Directory of Open Access Journals (Sweden)

    Robert Mansberg

    2013-12-01

    Full Text Available A 31 year old female with a 3 month history of focal right mid posterior thoracic pain, and solitary lytic lesion in the right 7th rib posteriorly on bone scan (SPECT/CT was referred for PET/CT to identify alternate site for biopsy in suspected malignancy. The patient had no significant past medical history and was afebrile with mildly elevated inflammatory markers. A solitary intensely FDG avid focus was demonstrated localised to a well-defined lytic lesion with partial cortical erosion on the posterior aspect of the right 7th rib. No adjacent soft tissue abnormality was seen. No other site of biopsy was demonstrated. As malignancy (metastatic or primary was not excluded, CT guided localisation with hookwire and blue dye injection was performed immediately prior to partial resection of the right 7th rib. Histopathology confirmed the diagnosis of eosinophilic granuloma.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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 ...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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...

  13. 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

  14. 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

  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. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  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. 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.).

  8. 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...

  9. "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 ...

  10. 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.

  11. 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...

  12. 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...

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

    Science.gov (United States)

    Jensen, P S; Watanabe, H

    1999-02-01

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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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 ...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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)....

  15. 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.

  16. 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.

  17. 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.

  18. 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.)

  19. 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.

  20. 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/.

  1. 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.

  2. 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 ...

  3. 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

  4. 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.

  5. 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

  6. 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.

  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. 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.

  9. 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

  10. 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

  11. 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...

  12. 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...

  13. 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.

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-15

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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. 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...

  8. 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...

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.)

  16. 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.

  17. 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...

  18. 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.

  19. 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

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    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...

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. Adult polycystic disease of kidneys: A potential cause of false-positive /sup 67/Ga images

    Energy Technology Data Exchange (ETDEWEB)

    Shih, W.J.; Domstad, P.A.; DeLand, F.H.; Purcell, M.

    1984-06-01

    A 56-year-old man with adult polycystic disease of the kidneys complicated by renal failure, hypertension, and bacteremia underwent bilateral nephrectomy because the enlarged kidneys compromised his gastrointestinal function and respiratory capacity. A scan using sup(99m)Tc-methylene diphosphonate demonstrated nonfunctioning kidneys, bilaterally. An unusual radioactivity pattern in the bowel in /sup 67/Ga scintigraphy was due to extreme renal enlargement and should be kept in mind to avoid misinterpretation.

  6. Due Process Hearing Case Study

    Science.gov (United States)

    Bateman, David F.

    2009-01-01

    William is 9 years of age, residing with his parent within the boundaries of an unnamed district ("the District"). As a student with autism he is eligible for special education programming and services. There was one issue presented for this due process hearing: What was the appropriate program and placement for him for the 2008-2009 school year?…

  7. 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.

  8. 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

  9. False positive in the measurement of thyroglobulin induced by rheumatoid factor.

    Science.gov (United States)

    Astarita, G; Gutiérrez, S; Kogovsek, N; Mormandi, E; Otero, P; Calabrese, C; Alcaraz, G; Vázquez, A; Abalovich, M

    2015-07-20

    We report a case of interference in thyroglobulin (Tg) measurement in a woman with differentiated thyroid cancer and rheumatoid arthritis history. Due to discordant Tg in relation to TSH concentrations and negative images, we investigated possible interference in the measurement of Tg. During the follow-up we measured Tg by chemiluminescence (TgQL) using Immulite 2000 immunoassay system. To investigate possible interference in Tg measurement, we made serial dilutions, re-testing of Tg by an alternative method: electrochemiluminescence, Cobas 6000 analyzer (TgEQL), recovery test of Tg and polyethylene glycol (PEG) 6000 precipitation. During the patient follow-up, the TgQL ranged between RF) were found. When RF titers were lowered post PEG precipitation, Tg QL concentrations became undetectable. We describe an unusual case of interference in Tg assay due to RF. When disagreement among Tg concentrations, images and clinical features is observed, we suggest taking into account the evaluation of possible Tg interference to avoid unnecessary complementary exams and inappropriate treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. 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.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    Proteolytic treatment of intact bacterial cells is an ideal means for identifying surface-exposed peptide epitopes and has potential for the discovery of novel vaccine targets. Cell stability during such treatment, however, may become compromised and result in the release of intracellular proteins...... that complicate the final analysis. Staphylococcus aureus is a major human pathogen, causing community and hospital-acquired infections, and is a serious healthcare concern due to the increasing prevalence of multiple antibiotic resistances amongst clinical isolates. We employed a cell surface "shaving" technique...... lysis and were removed from the trypsin-shaved data set. We identified 42 predicted S. aureus COL surface proteins from 260 surface-exposed peptides. Trypsin and proteinase-K digests were highly complementary with ten proteins identified by both, 16 specific to proteinase-K treatment, 13 specific...

  12. 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.

  13. Streptomycin interference in Jaffe reaction - Possible false positive creatinine estimation in excessive dose exposure

    DEFF Research Database (Denmark)

    Syal, Kirtimaan; Srinivasan, Anand; Banerjee, Dibyajyoti

    2013-01-01

    Objectives: To study the potential of commonly used aminoglycoside antibiotics to form non-creatinine chromogen with alkaline picrate reagent. Design and methods: We studied the non-creatinine chromogen formation of various concentrations of streptomycin, amikacin, kanamycin, netilmicin, gentamicin...

  14. 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.

  15. 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.

  16. 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.

  17. Ethnic hair care products may increase false positives in hair drug testing.

    Science.gov (United States)

    Kidwell, David A; Smith, Frederick P; Shepherd, Arica R

    2015-12-01

    The question of why different races appear more susceptible to hair contamination by external drugs remains controversial. This research studied susceptibility of head hair to external cocaine and methamphetamine when hair products have been applied. Three different chemical classes of ethnic hair products were applied to Caucasian, Asian, and African hair. Some products increased the methamphetamine and cocaine concentrations in all hair types. A unique finding of this research is that certain ethnic hair products can replace moisture as a diffusion medium, thereby increasing the susceptibility to contamination over 100-fold compared to petroleum-based products.

  18. The chemical-in-plug bacterial chemotaxis assay is prone to false positive responses

    Directory of Open Access Journals (Sweden)

    Ward Mandy J

    2010-03-01

    Full Text Available Abstract Background Chemical-in-plug assays are commonly used to study bacterial chemotaxis, sometimes in the absence of stringent controls. Results We report that non-chemotactic and non-motile mutants in two distinct bacterial species (Shewanella oneidensis and Helicobacter pylori show apparent zones of accumulation or clearing around test plugs containing potential attractants or repellents, respectively. Conclusions Our results suggest that the chemical-in-plug assay should be used with caution, that non-motile or non-chemotactic mutants should be employed as controls, and that results should be confirmed with other types of assays.

  19. 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

  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. Sequence Length Limits for Controlling False Positives in Discovering Nucleotide Sequence Motifs

    Institute of Scientific and Technical Information of China (English)

    CHEN Lei; QiAN Zi-liang

    2008-01-01

    In the study of motif discovery, especially the transcription factor DNA binding sites discovery, a too long input sequence would return non-informative motifs rather than those biological functional motifs. This paper gave theoretical analyses and computational experiments to suggest the length limits of the input sequence. When the sequence length exceeds a certain critical point, the probability of discovering the motif decreases sharply. The work not only gave an explanation on the unsatisfying results of the existed motif discovery problems that the input sequence length might be too long and exceed the point, but also provided an estimation of input sequence length we should accept to get more meaningful and reliable results in motif discovery.

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

    Science.gov (United States)

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

    2007-04-01

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

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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...

  13. 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.

  14. 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...

  15. 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.

  16. 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...

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    Shimpei Ogawa

    2009-04-01

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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. 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。

  8. 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.

  9. 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.

  10. 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

    . This data does not support the contention that an elevated LDH and lactate can yield a false positive serum ethanol result as run by enzymatic ethanol assay in live patients presenting to the emergency department.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Identifying Students' Mathematical Skills from a Multiple-Choice Diagnostic Test Using an Iterative Technique to Minimise False Positives

    Science.gov (United States)

    Manning, S.; Dix, A.

    2008-01-01

    There is anecdotal evidence that a significant number of students studying computing related courses at degree level have difficulty with sub-GCE mathematics. Testing of students' skills is often performed using diagnostic tests and a number of computer-based diagnostic tests exist, which work, essentially, by testing one specific diagnostic skill…

  2. ADAM 12 may be used to reduce the false positive rate of first trimester combined screening for Down syndrome

    DEFF Research Database (Denmark)

    Christiansen, Michael; Pihl, Kasper; Hedley, Paula L.

    2010-01-01

    BACKGROUND: ADAM12 has been shown to be an efficient maternal serum marker for Down syndrome (DS) in the first trimester; but recent studies, using a second generation assay, have not confirmed these findings. We examined the efficiency of a second generation assay for ADAM12. MATERIALS AND METHODS...

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

    OpenAIRE

    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; Craig R Tomlinson

    2009-01-01

    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 unadulte...

  4. 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.

  5. Value of combined XCT/SPECT technology for avoiding false positive planar (123)I-MIBG scintigraphy.

    Science.gov (United States)

    Ozer, S; Dobrozemsky, G; Kienast, O; Beheshti, M; Becherer, A; Niederle, B; Kainberger, F; Dudczak, R; Kurtaran, A

    2004-10-01

    The clinical value of combined XCT/SPECT technology in a single device in patients undergoing (123)I-MIBG scintigraphy was analyzed. 31 patients (19 men, 12 women; mean age 55 years, range: 31-79 years) demonstrating focal accumulation in planar (123)I-MIBG scan were further investigated with a double headed gamma camera with an X-ray tomograph mounted on the same gantry (GE Medical Systems, Millennium VG with Hawkeye, Milwaukee, USA) for anatomical definition of the focal (123)I-MIBG uptake. The patients were referred to (123)I-MIBG scintigraphy because of biochemically (81%) and/or clinically (19%) suspected pheochromocytoma. In 23 out of 31 patients (74%) the fused images demonstrated physiological accumulation (i. e. intestinal, renal) of (123)I-MIBG. In two patients (6%) suspected adrenal MIBG-accumulation was caused by inhomogeneous liver uptake. In two patients (6%) focal abdominal accumulation was correctly localised in the adrenal glands. Furthermore, the differentiation of bone metastasis from a local recurrence for phaeochromocytoma was accurately possible for two patients (6%). Adrenal lesions mimicking liver foci were correctly localised in the remaining two patients (6%). Our study demonstrates the clinical value of XCT/SPECT in a single device in patients demonstrating focal (123)I-MIBG uptake in planar scintigraphy. The combined XCT/SPECT technology provides a higher diagnostic accuracy.

  6. Value of combined XCT/SPECT technology for avoiding false positive planar {sup 123}I-MIGB scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Oezer, S.; Kienast, O.; Beheshti, M.; Becherer, A.; Kurtaran, A. [Vienna Medical Univ. (Austria). Dept. of Nuclear Medicine; Dobrozemsky, G. [Vienna Medical Univ. (Austria). Dept. of Nuclear Medicine; Vienna Medical Univ. (Austria). Biomedical Engineering and Physics; Niederle, B. [Vienna Medical Univ. (Austria). Section Endocrine Surgery; Kainberger, F. [Vienna Medical Univ. (Austria). Diagnostic Radiology; Dudczak, R. [Vienna Medical Univ. (Austria). Dept. of Nuclear Medicine; Vienna Medical Univ. (Austria). Ludwig Boltzmann Inst. of Nuclear Medicine

    2004-10-01

    Aim: The clinical value of combined XCT/SPECT technology in a single device in patients undergoing {sup 123}I-MIBG scintigraphy was analyzed. Methods: 31 patients (19 men, 12 women; mean age 55 years, range: 31-79 years) demonstrating focal accumulation in planar {sup 123}I-MIBG scan were further investigated with a double headed gamma camera with an X-ray tomograph mounted on the same gantry (GE Medical Systems, Millennium VG with Hawkeye, Milwaukee, USA) for anatomical definition of the focal {sup 123}I-MIBG uptake. The patients were referred to {sup 123}I-MIBG scintigraphy because of biochemically (81%) and/or clinically (19%) suspected pheochromocytoma. Results: In 23 out of 31 patients (74%) the fused images demonstrated physiological accumulation (i.e. intestinal, renal) of {sup 123}I-MIBG. In two patients (6%) suspected adrenal MIBG-accumulation was caused by inhomogeneous liver uptake. In two patients (6%) focal abdominal accumulation was correctly localised in the adrenal glands. Furthermore, the differentiation of bone metastasis from a local recurrence for phaeochromocytoma was accurately possible for two patients (6%). Adrenal lesions mimicking liver foci were correctly localised in the remaining two patients (6%). Conclusion: Our study demonstrates the clinical value of XCT/SPECT in single device in patients demonstrating focal {sup 123}I-MIBG uptake in planar scintigraphy. The combined XCT/SPECT technology provides a higher diagnostic accuracy. (orig.)

  7. 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.

  8. 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%....

  9. 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.

  10. 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....

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. Short term Heart Rate Variability to predict blood pressure drops due to standing: a pilot study.

    Science.gov (United States)

    Sannino, G; Melillo, P; Stranges, S; De Pietro, G; Pecchia, L

    2015-01-01

    Standing from a bed or chair may cause a significant lowering of blood pressure (ΔBP), which may have severe consequences such as, for example, falls in older subjects. The goal of this study was to develop a mathematical model to predict the ΔBP due to standing in healthy subjects, based on their Heart Rate Variability, recorded in the 5 minutes before standing. Heart Rate Variability was extracted from an electrocardiogram, recorded from 10 healthy subjects during the 5 minutes before standing. The blood pressure value was measured before and after rising. A mathematical model aiming to predict ΔBP based on Heart Rate Variability measurements was developed using a robust multi-linear regression and was validated with the leave-one-subject-out cross-validation technique. The model predicted correctly the ΔBP in 80% of experiments, with an error below the measurement error of sphygmomanometer digital devices (± 4.5 mmHg), a false negative rate of 7.5% and a false positive rate of 10%. The magnitude of the ΔBP was associated with a depressed and less chaotic Heart Rate Variability pattern. The present study showes that blood pressure lowering due to standing can be predicted by monitoring the Heart Rate Variability in the 5 minutes before standing.

  18. 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)

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.)

  7. 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.

  8. 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.

  9. 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.

  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. 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. 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.

  13. 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.

  14. 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).

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.)

  20. 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

  1. Study Of Gear Teeth Distortions Due To Heat Treatment

    Directory of Open Access Journals (Sweden)

    V. Khade

    2015-02-01

    Full Text Available Abstract The work aims to study the distortion occurred due to heat treatment on the Gear teeth. The paper studies various causes of distortion control techniques to eliminate distortion which includes changes in design selection of material heat treatment process mainly due to quenching that includes cooling rates quenching mediums fixtures. An experimental study and results conducted for the effects of the distortion on the Gear teeth and to reduce the distortion with certain changes design modification resulting in shape amp size changes phase changes changes in hardness microstructure and residual stresses. It is observed that adequate velocity of quench oil around the component to be heat treated ensures uniform amp desired cooling rate as per heat treatment cycle. Modification in design of baffles achieved the adequate velocity and minimization of distortion. Also Fixtures for holding finished parts or assemblies during heat treatment may be either support or restraint type to control dimensional relations during aging.

  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. 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。

  4. 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

  5. Damage studies on tungsten due to helium ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, N.J.; Buzarbaruah, N.; Mohanty, S.R., E-mail: smrutirm@yahoo.com

    2014-09-15

    Highlights: • Used plasma focus helium ion source to study radiation induced damage on tungsten. • Surface analyses confirm formation of micro-crack, bubbles, blisters, pinholes, etc. • XRD patterns confirm development of compressive stress due to thermal load. • Reduction in hardness value is observed in the case of exposed sample. - Abstract: Energetic and high fluence helium ions emitted in a plasma focus device have been used successfully to study the radiation induced damage on tungsten. The reference and irradiated samples were characterized by optical microscopy, field emission scanning electron microscopy, X-ray diffraction and by hardness testers. The micrographs of the irradiated samples at lower magnification show uniform mesh of cracks of micrometer width. However at higher magnification, various types of crystalline defects such as voids, pinholes, bubbles, blisters and microcracks are distinctly noticed. The prominent peaks in X-ray diffraction spectrum of irradiated samples are seen shifted toward higher Bragg angles, thus indicating accumulation of compressive stress due to the heat load delivered by helium ions. A marginal reduction in hardness of the irradiated sample is also noticed.

  6. 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

    procedure for solving linear equations. Although one conclusion is that in its simpler form this method does not constitute any substitute for the modern symbolic algebraic resolution of equations and linear systems, it certainly represents a valuable springboard to reach a more formalised study. Particularly, the false position method is a very useful pedagogical tool in mathematics education, mainly when it is interwoven with its initial concrete approaches and its associations with geometry and analytical geometry.

  7. The Influence of Feedback of Diagnosis and Executive Function Skills on Rates of False Positive and False Negative Outcomes for ADHD

    Science.gov (United States)

    Bender, Stacy L.; Privitera, Gregory J.

    2016-01-01

    This study examined executive function (EF) skills and self-reported symptoms of ADHD. EF skills were measured to determine whether skills were different between groups that reported clinical levels of ADHD symptoms (clinical group) and nonclinical levels of ADHD symptoms (nonclinical group). EF skills in the nonclinical group were also…

  8. Genetic screening for von Hippel-Lindau gene mutations in non-syndromic pheochromocytoma: low prevalence and false-positives or misdiagnosis indicate a need for caution.

    NARCIS (Netherlands)

    Eisenhofer, G.; Vocke, C.D.; Elkahloun, A.; Huynh, T.T.; Prodanov, T.; Lenders, J.W.M.; Timmers, H.J.L.M.; Benhammou, J.N.; Linehan, W.M.; Pacak, K.

    2012-01-01

    Genetic testing of tumor susceptibility genes is now recommended in most patients with pheochromocytoma or paraganglioma (PPGL), even in the absence of a syndromic presentation. Once a mutation is diagnosed there is rarely follow-up validation to assess the possibility of misdiagnosis. This study

  9. 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 .

  10. False-positive defects in technetium-99m sestamibi myocardial single-photon emission tomography in healthy athletes with left ventricular hypertrophy

    Energy Technology Data Exchange (ETDEWEB)

    Bartram, P.; Hanel, B.; Gustafsson, F.; Mortensen, J.; Hesse, B. [Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital (Denmark); Toft, J. [Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital (Denmark)]|[Copenhagen City Heart Study, Epidemiological Research Unit (Denmark); Ali, S. [Dept. of Cardiology, Copenhagen University Hospital (Denmark)

    1998-09-01

    Exercise ECG and myocardial single-photon emission tomography (SPET) are fundamental in the non-invasive evaluation of patients suspected of having coronary artery disease (CAD). The purpose of the present study was to investigate the influence of physiological left ventricular hypertrophy (LVH) on myocardial sestamibi SPET in healthy young and old athletes. Eighteen young male elite athletes (ten rowers, five power/weight lifters and three triathletes) and 14 well-trained elderly rowers were studied. All underwent a bicycle test as part of a 2-day sestamibi SPET protocol. Attenuation correction was not performed. The studies were evaluated visually and quantitatively analysed by the CEqual program with its reference files and with a file from a local non-athletic age-matched population. Echocardiographic LVH was an inclusion criterion in the young athletes. Exercise ECG was normal in all subjects. In at least three of the young athletes a reversible defect was observed by visual analysis. On quantitative analysis one-third of the young athletes had ``significant`` (>10 pixels) defects compared with both the local reference base and the CEqual reference population. Nearly all defects were found in the anterior or inferior wall. The remaining subjects, including all old rowers, had normal SPET findings. Anterior and inferior wall defects are so common in healthy athletes with physiological LVH that the specificity of myocardial SPET, in contrast to exercise ECG, seems to be too low for evaluation of chest pain in this group. The mechanism of anterior and inferior defects may be related to hot spots (papillary muscles?) in the lateral wall. The specificity of SPET is maintained in athletes without LVH. (orig.) With 1 fig., 26 tabs., 22 refs.

  11. A High-Throughput Mass Spectrometry Assay Coupled with Redox Activity Testing Reduces Artifacts and False Positives in Lysine Demethylase Screening.

    Science.gov (United States)

    Wigle, Tim J; Swinger, Kerren K; Campbell, John E; Scholle, Michael D; Sherrill, John; Admirand, Elizabeth A; Boriack-Sjodin, P Ann; Kuntz, Kevin W; Chesworth, Richard; Moyer, Mikel P; Scott, Margaret Porter; Copeland, Robert A

    2015-07-01

    Demethylation of histones by lysine demethylases (KDMs) plays a critical role in controlling gene transcription. Aberrant demethylation may play a causal role in diseases such as cancer. Despite the biological significance of these enzymes, there are limited assay technologies for study of KDMs and few quality chemical probes available to interrogate their biology. In this report, we demonstrate the utility of self-assembled monolayer desorption/ionization (SAMDI) mass spectrometry for the investigation of quantitative KDM enzyme kinetics and for high-throughput screening for KDM inhibitors. SAMDI can be performed in 384-well format and rapidly allows reaction components to be purified prior to injection into a mass spectrometer, without a throughput-limiting liquid chromatography step. We developed sensitive and robust assays for KDM1A (LSD1, AOF2) and KDM4C (JMJD2C, GASC1) and screened 13,824 compounds against each enzyme. Hits were rapidly triaged using a redox assay to identify compounds that interfered with the catalytic oxidation chemistry used by the KDMs for the demethylation reaction. We find that overall this high-throughput mass spectrometry platform coupled with the elimination of redox active compounds leads to a hit rate that is manageable for follow-up work.

  12. Insufficient neutralization in testing a chlorhexidine-containing ethanol-based hand rub can result in a false positive efficacy assessment

    Directory of Open Access Journals (Sweden)

    Kampf Günter

    2005-06-01

    Full Text Available Abstract Background Effective neutralization in testing hand hygiene preparations is considered to be a crucial element to ensure validity of the test results, especially with the difficulty to neutralize chlorhexidine gluconate. Aim of the study was to measure the effect of chemical neutralization under practical test conditions according to EN 1500. Methods We have investigated two ethanol-based hand rubs (product A, based on 61% ethanol and 1% chlorhexidine gluconate; product B, based on 85% ethanol. The efficacy of products (application of 3 ml for 30 s was compared to 2-propanol 60% (v/v (two 3 ml rubs of 30 s each on hands artificially contaminated with Escherichia coli using a cross-over design with 15 volunteers. Pre-values were obtained by rubbing fingertips for 1 minute in liquid broth. Post-values were determined by sampling immediately after disinfection in liquid broth with and without neutralizers (0.5% lecithin, 4% polysorbate 20. Results The neutralizers were found to be effective and non-toxic. Without neutralization in the sampling fluid, the reference disinfection reduced the test bacteria by 3.7 log10, product B by 3.3 log10 and product A by 4.8 log10 (P = 0.001; ANOVA. With neutralization the reference disinfection reduced the test bacteria by 3.5 log10, product B by 3.3 log10 and product A by 2.7 log10 (P = 0.011; ANOVA. In comparison to the reference treatment Product B lead to a lower mean reduction than the reference disinfection but the difference was not significant (P > 0.1; Wilcoxon-Wilcox test. Without neutralizing agents in the sampling fluid, product A yielded a significantly higher reduction of test bacteria (4.8; P = 0.02 as compared to the situation with neutralizing agents (2.7; P = 0.033. Conclusion The crucial step of neutralization lies in the sampling fluid itself in order to stop any residual bacteriostatic or bactericidal activity immediately after the application of the preparation, especially with

  13. A CLINICORADIOLOGICAL STUDY OF MIDDLE LOBE SYNDROME DUE TO TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    Saurabh Karmakar

    2016-09-01

    Full Text Available BACKGROUND Although pulmonary tuberculosis is a common disease in India, tuberculosis of right middle lobe is infrequent. Tuberculosis of the right middle lobe leading to chronic collapse is a cause of Right Middle Lobe syndrome. METHODS The patients attended Pulmonary Medicine Outdoor at Era’s Lucknow Medical College, Lucknow from April 2015 to March 2016. The purpose of this study is to describe the clinicoradiological features of patients of middle lobe syndrome due to tuberculosis. All patients presented with cough with or without expectoration, fever, chest pain, haemoptysis and constitutional symptoms like loss of appetite and weight. Chest X-ray PA view revealed ill-defined opacity abutting the right cardiac border. HRCT thorax was done in each case. The diagnosis of tuberculous aetiology was based on (1 History of chronic cough and fever, not responding to antibiotic therapy and constitutional symptoms, (2 A positive tuberculin test using 2 TU of PPD RT 23 and (3 Detection of acid fast bacilli by direct smear or Mycobacterium tuberculosis by polymerase chain reaction in bronchoalveolar lavage. RESULTS Out of 10 patients, 4 (40% were males and 6 (60% were females. The mean ages of the males were 55.8 years and females were 60.8 years and overall mean age was 59 years. Most of the patients were females and belonged to the middle age and old age group. ATT was started in all the patients. CONCLUSIONS Right middle lobe syndrome predominantly affects the older population and the female gender. Although tuberculosis is a common disease in India, Middle Lobe Syndrome is a very rare presentation of the disease. Due to non-specific symptoms and usually normal chest X-ray PA view in Right Middle Lobe Syndrome, we should keep a high index of suspicion to diagnose the condition.

  14. 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.

  15. 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.

  16. 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.

  17. Study of Compton Broadening Due to Electron-Photon Scattering

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao, M.

    2010-06-01

    Full Text Available We have investigated the effects of Compton broadening due to electron-photon scattering in hot stellar atmospheres. A purely electron-photon scattering media is assumed to have plane parallel geometry with an input radiation field localized on one side of the slab. The method is based on the discrete space theory of radiative transfer for the intensity of emitted radiation.The solution is developed to study the importance of scattering of radiation by free electrons in high temperature stellar atmospheres which produces a brodening and shift in spectral lines because of the Compton effect and the Doppler effect arising from mass and thermal motions of scattering electrons.It is noticed that the Comptonized spectrum depends on three parameters: the optical depth of the medium, the temperature of the thermal electrons and the viewing angle.We also showed that the Compton effect produces red shift and asymmetry in the line. These two effects increase as the optical depth increases. It is also noticed that the emergent specific intensities become completely asymmetric for higher optical depths.

  18. 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

  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. 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.

  1. CLINICOMICROBIOLOGICAL STUDY OF INFECTIONS DUE TO CITROBACTER SPECIES

    OpenAIRE

    Dhanya; Sevitha

    2015-01-01

    BACKGROUND & OBJECTIVES: Citrobacter species have emerged as important nosocomial pathogens . The infections caused by this organism include UTI , wound infection , Neonatal sepsis , pulmonary infection , brain abscess , meningitis . The organism is recovered from a variety of clinical specimen incl uding pus , urine , sputum . Antibiotic resistance is on rise among the Citrobacter spp . The present study w...

  2. Study of annoyance due to urban automobile traffic

    Science.gov (United States)

    Aubree, D.; Auzou, S.; Rapin, J. M.

    1984-01-01

    Continuous traffic noise measurements were carried out over 48 hour periods in front of a hundred buildings in different types of streets in Paris and its suburbs. Physical interpretation of the results provides a noise prediction formula for a traditional type of street. The noise at each point was characterized by a limited number of parameters by means of factor analysis, and their effect on the degree of disturbance by 700 individuals questioned near the measurement stations was studied. It was found that many additional factors affect disturbance besides noise, and that the dispersion of replies for any given noise situation is very wide. A disturbance index is proposed which takes into account the daylight level L(50), the position of rooms in the dwelling exposed to noise, and the individual degrees of satisfaction with the area.

  3. 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

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

    Science.gov (United States)

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

    2011-12-01

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

  5. Bias due to composite reference standards in diagnostic accuracy studies.

    Science.gov (United States)

    Schiller, Ian; van Smeden, Maarten; Hadgu, Alula; Libman, Michael; Reitsma, Johannes B; Dendukuri, Nandini

    2016-04-30

    Composite reference standards (CRSs) have been advocated in diagnostic accuracy studies in the absence of a perfect reference standard. The rationale is that combining results of multiple imperfect tests leads to a more accurate reference than any one test in isolation. Focusing on a CRS that classifies subjects as disease positive if at least one component test is positive, we derive algebraic expressions for sensitivity and specificity of this CRS, sensitivity and specificity of a new (index) test compared with this CRS, as well as the CRS-based prevalence. We use as a motivating example the problem of evaluating a new test for Chlamydia trachomatis, an asymptomatic disease for which no gold-standard test exists. As the number of component tests increases, sensitivity of this CRS increases at the expense specificity, unless all tests have perfect specificity. Therefore, such a CRS can lead to significantly biased accuracy estimates of the index test. The bias depends on disease prevalence and accuracy of the CRS. Further, conditional dependence between the CRS and index test can lead to over-estimation of index test accuracy estimates. This commonly-used CRS combines results from multiple imperfect tests in a way that ignores information and therefore is not guaranteed to improve over a single imperfect reference unless each component test has perfect specificity, and the CRS is conditionally independent of the index test. When these conditions are not met, as in the case of C. trachomatis testing, more realistic statistical models should be researched instead of relying on such CRSs.

  6. 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.

  7. 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...

  8. 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

  9. 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

  10. Bringing Benefits and Warding off Blights in Due Commandment (Analytic Study Compared with the Jordanian Law)

    Science.gov (United States)

    Al Etoum, Niebal Mohd Ibrahim; Mowafi, Hanan Sami Mohammad; Al Zubaidi, Faraj Hamad Salem

    2016-01-01

    The study aims to highlight the benefits and blights of the due commandment (intestate law) under Jordanian law for the year (2010) in the article (279). The study came in two sections, the first one dealt with the concept of due commandment, its legitimacy, verdict and terms; in the second section, I've dealt with the persons entitled to due…

  11. Contrast study on CT and BA in cerebral hemorrhage due to hypertension%CONTRAST STUDY ON CT AND BA IN CEREBRAL HEMORRHAGE DUE TO HYPERTENSION

    Institute of Scientific and Technical Information of China (English)

    Mingshun Liu; Guoqiu Wang; Po Ma

    2007-01-01

    Objectives:To explore contrast application on CT and BA in cerebral hemorrhage due to hypertension. Methods: CT and BA were examined in 106 patients with cerebral hemorrhage due to hypertension. Results:The different changes of CT and BA were showed in 106 patients with cerebral hemorrhage due to hypertension. Conclusions: There were separately different advantage and shortcoming in CT and BA in diagnosis of cerebral hemorrhage due to hypertension. The value of clinical application of BA was important in cerebral hemorrhage due to hypertension.

  12. Due Permafrost: a Circumpolar Remote Sensing Service for Permafrost - Evaluation and Application Case Studies

    Science.gov (United States)

    Heim, B.; Bartsch, A.; Elger, K. K.; Rinke, A.; Gellhorn, C.; Matthes, H.; Buchhorn, M.; Klehmet, K.; Soliman, A. S.; Duguay, C.; Hachem, S.; Schwamborn, G.; Muster, S.; Langer, M.; Boike, J.; Lantuit, H.; Herzschuh, U.; Seifert, F.

    2012-12-01

    The task of the ESA Data User Element DUE Permafrost project is to build up a Remote Sensing Service for permafrost applications. The DUE Permafrost remote sensing products are land temperature, soil moisture, frozen/thawed surface status, terrain parameters, land cover, and surface waters. The DUE Permafrost products are freely available for download under http://www.ipf.tuwien.ac.at/permafrost/. The products are also published at the world data centre PANGAEA (doi:10.1594/PANGAEA.780111, 2012: ESA Data User Element Permafrost), Snow parameters (snow extent and snow water equivalent) can be derived from the ESA DUE project GlobSnow. A major component is the evaluation of the DUE Permafrost products to test their scientific validity for high-latitudinal permafrost landscapes. The primary programme providing ground data is the Global Terrestrial Network for Permafrost (GTN-P) initiated by the International Permafrost Association (IPA). The involvement of scientific stakeholders and the IPA, and the ongoing evaluation of the remote sensing derived products make the DUE Permafrost products accepted by the scientific community. We show evaluation case studies of DUE Permafrost remote sensing products using GTN-P in-situ data in Alaska and Siberia. The Helmholtz Climate Initiative REKLIM (Regionale Klimaänderungen/Regional climate change) is a climate research program where regional observations and process studies are innovatively coupled with model simulations (http://www.reklim.de/en/home/). Within the REKLIM framework we spatio-temporally compare the geophysical surface parameters derived from regional climate modelling with the DUE Permafrost and DUE GlobSnow remote sensing products. The case studies are: i) spatio-temporal comparison of the ESA GlobSnow satellite-derived snow-water equivalent data with the output from the regional climate model COSMO-CLM for Central Siberia for 1987-2010. ii) circum-arctic spatio-temporal comparison of the ESA DUE Permafrost

  13. The predictors of absenteeism due to psychological disability: a longitudinal study in the education sector.

    Science.gov (United States)

    Negrini, Alessia; Perron, Jacques; Corbière, Marc

    2014-01-01

    Being absent from work because of a psychological disability is costly for both individuals and organizations and frequent in employees working in the field of education. Absenteeism from work has been mostly studied as an organizational withdrawal behavior related to negative factors. The purpose of this longitudinal study is to define the predictors of absenteeism due to psychological disability by taking into account resources, such as Self-determined work motivation and Subjective well-being, as well as symptoms of Psychological distress. The sample consisted of 261 employees from a Canadian public school organization. Independent sample t-tests were conducted to compare the mean scores of participants who were not absent from work and participants who were absent due to psychological disability. Logistic regression analyses were computed for the dependent variable to assess the contribution of the three independent variables. Participants who were absent from work due to psychological disability in the year following the data collection scored significantly lower on resources, and higher on symptoms than those participants who were not absent. The three-predictor model was found to be significant. However, only Self-determined work motivation and Psychological distress significantly predicted absenteeism due to psychological disability. Results are discussed in terms of psychological processes regulating the relationships between the work-related factors (i.e., work motivation) and life-related factors (i.e., psychological distress and subjective well-being) of personal adjustment and accomplishment.

  14. A Longitudinal Study of Special Education Due Process Hearings in Massachusetts

    Directory of Open Access Journals (Sweden)

    William H. Blackwell

    2015-03-01

    Full Text Available Of the three formal dispute resolution procedures provided by the Individuals With Disabilities Education Act of 2004(IDEA, due process hearings are the most costly in terms of time, fiscal resources, and impact on relationships between school personnel and parents. This study examined 258 due process hearings held over the past 8 years in Massachusetts to examine the characteristics of students at the center of these disputes, the issues that were addressed in the hearings, and the representation utilized by parents and school districts. The findings from this study indicated that (a Massachusetts school districts utilized attorney representation and won due process hearings at notably higher levels than parents, and (b the most frequently addressed issues at due process hearings were Individualized Education Program (IEP development/implementation and educational program placement, which are issues that represent the core mandate of IDEA to provide a free appropriate public education in the least restrictive environment (34 C.F.R. §300.300, 300.550. The authors present recommendations for policy actions and areas for future research.

  15. A Study of Permeability Changes Due to Cold Fluid Circulation in Fractured Geothermal Reservoirs.

    Science.gov (United States)

    Gholizadeh Doonechaly, Nima; Abdel Azim, Reda R; Rahman, Sheik S

    2016-05-01

    Reservoir behavior due to injection and circulation of cold fluid is studied with a shear displacement model based on the distributed dislocation technique, in a poro-thermoelastic environment. The approach is applied to a selected volume of Soultz geothermal reservoir at a depth range of 3600 to 3700 m. Permeability enhancement and geothermal potential of Soultz geothermal reservoir are assessed over a stimulation period of 3 months and a fluid circulation period of 14 years. This study-by shedding light onto another source of uncertainty-points toward a special role for the fracture surface asperities in predicting the shear dilation of fractures. It was also observed that thermal stress has a significant impact on changing the reservoir stress field. The effect of thermal stresses on reservoir behavior is more evident over longer circulation term as the rock matrix temperature is significantly lowered. Change in the fracture permeability due to the thermal stresses can also lead to the short circuiting between the injection and production wells which in turn decreases the produced fluid temperature significantly. The effect of thermal stress persists during the whole circulation period as it has significant impact on the continuous increase in the flow rate due to improved permeability over the circulation period. In the current study, taking into account the thermal stress resulted in a decrease of about 7 °C in predicted produced fluid temperature after 14 years of cold fluid circulation; a difference which notably influences the potential prediction of an enhanced geothermal system.

  16. Numerical simulation study on spin resonant depolarization due to spin-orbit coupling

    Institute of Scientific and Technical Information of China (English)

    Lan Jie-Qin; Xu Hong-Liang

    2012-01-01

    The spin polarization phenomenon in lepton circular accelerators had been known for many years.It provides a new approach for physicists to study the spin feature of fundamental particles and the dynamics of spin-orbit coupling,such as spin resonances.We use numerical simulation to study the features of spin under the modulation of orbital motion in an electron storage ring.The various cases of depolarization due to spin-orbit coupling through an emitting photon and misalignment of magnets in the ring are discussed.

  17. CHANGES IN CARDIAC STATUS DUE TO ISOLATED SYSTOLIC HYPERTENSION BY NON - INVASIVE STUDIES

    Directory of Open Access Journals (Sweden)

    Sourangsu

    2014-01-01

    Full Text Available AIM : It was thought previously that morbidity and mortality are directly related to both Systolic and Diastolic blood pressure . However evidences from different studies suggest that systolic hypertension deserves more importance especially due to its profound effect on cardiovascular disease progression. Isolated systolic hypertension (ISH has now increased amongst the elderly population due to inc reased longevity. METHOD : Total 240 patients of 65 – 89 years age group were taken as study group at the out - patient and in - door department of CNMC Kolkata and NBMC , Siliguri. All patients were divided into three groups based on systolic blood pressure : Gr A=SBP - 140 — 159 mmHg , Gr B=SBP - 160 - 179 mmHg & Gr C=SBP>180 mmHg with each group having age and sex matched 100 healthy normotensive control subjects. History , Clinical examination , ECG and Echocardiographic studies were done in the selected patients . Sop histicated tests were not done due to nonavailability. RESULTS : Major Electrocardiogram changes are left atrial enlargement , left ventricular hypertrophy with systolic strain , Inferior wall ischemia , both bundle branch blocks , bifascicular block , left axis deviation. Other minor changes were : antero - septal ischemia , septal wall ischemia , lateral wallischemia , right axis deviation , arrhythmia , and low voltage were also noted. Echocardiography in 2 - D and M - ModeandEcho - Doppler assessment showed incre ased Intraventricular septal thickness (IVST , Left ventricular posterior wall Thickness (LVPWT and Left ventricular mass index were the major changes. Left ventricular functional abnormality like diastolic dysfunction was another significant abnormality. CONCLUSION : Different anatomical & functional changes in ISH are more prevalent in higher SBP group , and strong risk factor for future catastrophic cardiac events. It is an independent risk factor for CVS morbidity and mortality. Early therapeutic interve ntion

  18. 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 ...

  19. 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...

  20. A study among the population of Sevilla of death due to submersion.

    Science.gov (United States)

    Gamero, J; Romero, J L; Arufe, M I; Vizcaya, M A; Balanza, E

    1997-03-01

    Death due to submersion is of great interest from the medical-legal point of view, given the increase in nautical activity among children and adults alike over the past number of years. However, the lack of reliable statistical data concerning the impact of this specific form of death in our country must be emphasized. These are the circumstances that have led us to study the incidence of this form of death in a specific area. The population analyzed lived in the city of Sevilla during the period 1967-1993.

  1. Nationwide (Denmark) Study of Symptoms Preceding Sudden Death due to Arrhythmogenic Right Ventricular Cardiomyopathy

    DEFF Research Database (Denmark)

    Sadjadieh, Golnaz; Jabbari, Reza; Risgaard, Bjarke

    2014-01-01

    In this study, we investigated medical history and symptoms before death in all subjects aged 1 to 35 years who died a sudden cardiac death (SCD) from arrhythmogenic right ventricular cardiomyopathy (ARVC) in Denmark in the years 2000 to 2006. All deaths (n=6,629) in subjects aged 1 to 35 years...... in Denmark in the period 2000 to 2006 were included. A total of 16 cases of SCD due to ARVC were identified based on histopathologic examination. Information on medical history was retrieved from The National Patient Registry, general practitioners, and hospitals. Symptoms before death were compared with 2...

  2. The Study of Optically Induced Effects due to Bending and Twisting using Vector Finite Element Method

    Energy Technology Data Exchange (ETDEWEB)

    Dacles-Mariani, J; Rodrigue, G

    2005-05-11

    We study the effects of macroscopic bends and twists in an optical waveguide and how they influence the transmission capabilities of a waveguide. These mechanical stresses and strains distort the optical indicatrix of the medium producing optical anisotropy. The spatially varying refractive indices are incorporated into the full-wave Maxwell's equations. The governing equations are discretized using a vector finite element method cast in a high-order finite element approximation. This approach allows us to study the complexities of the mechanical deformation within a framework of a high-order formulation which can in turn, reduce the computational requirement without degrading its performance. The optical activities generated, total energy produced and power loss due to the mechanical stresses and strains are reported and discussed.

  3. MORBIDITY AND MORTALITY DUE TO AIDS: A STUDY OF BURDEN OF DISEASE AT A MUNICIPAL LEVEL

    Directory of Open Access Journals (Sweden)

    Jane DA SILVA

    2015-10-01

    Full Text Available Introduction: The purpose of measuring the burden of disease involves aggregating morbidity and mortality components into a single indicator, the disability-adjusted life year (DALY, to measure how much and how people live and suffer the impact of a disease. Objective: To estimate the global burden of disease due to AIDS in a municipality of southern Brazil. Methods: An ecological study was conducted in 2009 to examine the incidence and AIDS-related deaths among the population residing in the city of Tubarao, Santa Catarina State, Brazil. Data from the Mortality Information System in the National Health System was used to calculate the years of life lost (YLL due to premature mortality. The calculation was based on the difference between a standardized life expectancy and age at death, with a discount rate of 3% per year. Data from the Information System for Notifiable Diseases were used to calculate the years lived with disability (YLD. The DALY was estimated by the sum of YLL and YLD. Indicator rates were estimated per 100,000 inhabitants, distributed by age and gender. Results: A total of 131 records were examined, and a 572.5 DALYs were estimated, which generated a rate of 593.1 DALYs/100,000 inhabitants. The rate among men amounted to 780.7 DALYs/100,000, whereas among women the rate was 417.1 DALYs/100,000. The most affected age groups were 30-44 years for men and 60-69 years for women. Conclusion: The burden of disease due to AIDS in the city of Tubarao was relatively high when considering the global trend. The mortality component accounted for more than 90% of the burden of disease.

  4. MORBIDITY AND MORTALITY DUE TO AIDS: A STUDY OF BURDEN OF DISEASE AT A MUNICIPAL LEVEL

    Science.gov (United States)

    SILVA, Jane DA; RAMOS, Victoria; SILVA, Helena Caetano Gonçalves DA; TRAEBERT, Jefferson

    2015-01-01

    Introduction: The purpose of measuring the burden of disease involves aggregating morbidity and mortality components into a single indicator, the disability-adjusted life year (DALY), to measure how much and how people live and suffer the impact of a disease. Objective: To estimate the global burden of disease due to AIDS in a municipality of southern Brazil. Methods: An ecological study was conducted in 2009 to examine the incidence and AIDS-related deaths among the population residing in the city of Tubarao, Santa Catarina State, Brazil. Data from the Mortality Information System in the National Health System was used to calculate the years of life lost (YLL) due to premature mortality. The calculation was based on the difference between a standardized life expectancy and age at death, with a discount rate of 3% per year. Data from the Information System for Notifiable Diseases were used to calculate the years lived with disability (YLD). The DALY was estimated by the sum of YLL and YLD. Indicator rates were estimated per 100,000 inhabitants, distributed by age and gender. Results: A total of 131 records were examined, and a 572.5 DALYs were estimated, which generated a rate of 593.1 DALYs/100,000 inhabitants. The rate among men amounted to 780.7 DALYs/100,000, whereas among women the rate was 417.1 DALYs/100,000. The most affected age groups were 30-44 years for men and 60-69 years for women. Conclusion: The burden of disease due to AIDS in the city of Tubarao was relatively high when considering the global trend. The mortality component accounted for more than 90% of the burden of disease. PMID:26603227

  5. [Descriptive study of morbidity and mortality due to asthma at a Health Sector institution].

    Science.gov (United States)

    Segura Méndez, N H; Salas Ramírez, M; Martínez-Cairo Cueto, S

    1994-01-01

    The objective of this study was to determine the morbidity and mortality rate due to asthma from a Health Institution, which represents the majority of working population. Asthma data were obtained from the National Institute of Informatical, Geography and Statistics (INEGI), Mexican Health Secretary (SS) and Mexican Social Security Institute (IMSS). The underlying cause of death hospitalization or visit were obtained. Asthma was coded according to the International Classification of Disease (ninth revision). Asthma death rate was adjusted by age using direct method. In the IMSS, asthma death rate increased from 3.24/200,000 in 1980 to 12.76/100,000 in 1990. The asthma letality increased from 0.34 in 1980 to 1.23 in 1990. The average length of hospital stay was 3.96 days in 1990; there was noy significant differences by sex the most affected groups were children under 4 years of age and persons older than 65 years of age. In conclusion, from 1980 to 1990, the morbidity and mortality rate due to asthma in IMSS increased. It suggests that future health policy efforts should be focused to reduce the morbidity, mainly in high risk groups.

  6. Cattle mortality due to poisoning in Spain: a cross-sectional epidemiological study

    Energy Technology Data Exchange (ETDEWEB)

    García-Arroyo, R.; Míguez, M.P.; Hevia, M.L.; Quiles, A.

    2015-07-01

    The lack of nationwide public databases on poisoning in cattle makes it difficult to investigate this issue. Hence, we conducted an epidemiological study using the data on cattle poisoning provided by an insurance company (2000-2005), to determine the mortality rate due to poisoning in cattle in Spain and to assess the influence of the following variables: type of farming, age, sex, time of year, year and region. We observed a mortality rate of 23.25 per 100,000 animals in Spain with a higher rate in beef than dairy cattle (32.14 vs. 4.51 per 100,000 animals). There were also differences in the mortality rate between breeding cattle and future breeders, affecting dairy and beef cattle in a different way. In dairy cattle, we found differences between the years analysed. In beef cattle, the time of year with highest risk of poisoning was the last quarter (19.45 per 100,000 animals), while the lowest mortality rate was observed in the first quarter (1.33 per 100,000). There were pronounced differences between regions in beef cattle, differences being non-significant in dairy cattle. Lastly, in beef cattle, no differences were found between sexes. In summary, the mortality rate due to poisoning in cattle in Spain is low, and the risk of poisoning is determined by the farming system, animals’ stage of development, time of year and region. (Author)

  7. Observational study of upper ocean cooling due to Phet super cyclone in the Arabian Sea

    Science.gov (United States)

    Muni Krishna, K.

    2016-05-01

    Phet super cyclone (31 May-7 June 2010) was the most intense and also the rarest of the rare track in Arabian Sea as per the recorded history during 1877-2009. The present study focuses on the ocean physical responses to Phet cyclone using satellite and Argo observations. The sea surface temperature is decreased to 6 °C with an approximately 350 km long and 100 km width area in the Arabian Sea after the cyclone passage. The translation speed of cyclone is 3.86 m/s, the mixed layer is 79 m, and thermocline displacement is 13 m at the cooling area. With the relationship of wind stress curl and Ekman pumping velocity (EPV), the author found that the speed of EPV was increased after the passage of cyclone. So the extent of the SST drop was probably due to the moving speed of cyclone and the depth of the mixed layer.

  8. Parametric Study of Damage Evaluation into Solid Dielectrics Due to PD Activity Using a Kinetic Model

    Directory of Open Access Journals (Sweden)

    Alireza Ganjovi

    2014-09-01

    Full Text Available A kinetic model is used based on Particle in Cell - Monte Carlo Collision (PIC-MCC model, for parametric study of the damage due to partial discharges (PD activity into the surroundings dielectrics of a narrow channel encapsulated within the volume of a dielectric material. The parameters studied are applied electric field, channel dimensions and gas pressure. After employing an electric field across a dielectric material which contains a narrow channel, repeated ionization process starts in the gaseous medium of narrow channel. Charged particles, especially electrons, gain energy from the electric field across narrow channel and cause damage into dielectric surfaces of narrow channel on impact. The dependence of the electron energy distribution function (EEDF on the applied electric field is considered. These estimations are performed based on the number of C-H bond-scissions produced by the impacting electrons of a single PD pulse. Regarding this technique, the consequent damage into the solid dielectric and the time required to increase surface conductivity, is computed. The formation of acid molecules due to interaction of PD pulse with polymer surface in presence of air and humidity causes changes in the surface conductivity of the surrounding dielectrics of the narrow channels. It is observed that the extent of damage caused by a PD is primarily determined by the total number of impacting electrons which are capable of producing bond-scission at the dielectric. Parameters that effectively cause an increase in the number of energetic electrons will increase effective damage as well as surface conductivity of surrounding dielectrics.

  9. Modulation of the lipidomic profile due to a lipid challenge and fitness level: a postprandial study.

    Science.gov (United States)

    Morris, Ciara; O'Grada, Colm M; Ryan, Miriam F; Gibney, Michael J; Roche, Helen M; Gibney, Eileen R; Brennan, Lorraine

    2015-07-01

    The lipid composition of plasma is known to vary due to both phenotypic factors such as age, gender and BMI as well as with various diseases including cancer and neurological disorders. However, there is little investigation into the variation in the lipidome due to exercise and/ or metabolic challenges. The objectives of this present study were (i) To identify the glycerophospholipid, sphingolipids and ceramide changes in response to an oral lipid tolerance test (OLTT) in healthy adults and (ii) To identify the effect of aerobic fitness level on lipidomic profiles. 214 healthy adults aged 18-60 years were recruited as part of a metabolic challenge study. A sub-group of 40 volunteers were selected for lipidomic analysis based on their aerobic fitness level. Ceramides, glycerophospholipids and sphingomyelins were quantified in baseline fasting plasma samples as well as at 60, 120, 180, 240 and 300 min following a lipid challenge using high-throughput flow injection ESI-MS/MS. Mixed model repeated measures analysis identified lipids which were significantly changing over the time course of the lipid challenge. Included in these lipids were lysophosphoethanolamines (LPE), phosphoethanolamines (PE), phosphoglycerides (PG) and ceramides (Cer). Five lipids (LPE a C18:2, LPE a C18:1, PE aa C36:2, PE aa C36:3 and N-C16:1-Cer) had a fold change > 1.5 at 120 min following the challenge and these lipids remained elevated. Furthermore, three of these lipids (LPE a C18:2, PE aa C36:2 and PE aa C36:3) were predictive of fasting and peak plasma TAG concentrations following the OLTT. Further analysis revealed that fitness level has a significant impact on the response to the OLTT: in particular significant differences between fitness groups were observed for phosphatidylcholines (PC), sphingomyelins (SM) and ceramides. This study identified specific lipids which were modulated by an acute lipid challenge. Furthermore, it identified a series of lipids which were modulated by

  10. Human health risk assessment due to global warming--a case study of the Gulf countries.

    Science.gov (United States)

    Husain, Tahir; Chaudhary, Junaid Rafi

    2008-12-01

    Accelerated global warming is predicted by the Intergovernmental Panel on Climatic Change (IPCC) due to increasing anthropogenic greenhouse gas emissions. The climate changes are anticipated to have a long-term impact on human health, marine and terrestrial ecosystems, water resources and vegetation. Due to rising sea levels, low lying coastal regions will be flooded, farmlands will be threatened and scarcity of fresh water resources will be aggravated. This will in turn cause increased human suffering in different parts of the world. Spread of disease vectors will contribute towards high mortality, along with the heat related deaths. Arid and hot climatic regions will face devastating effects risking survival of the fragile plant species, wild animals, and other desert ecosystems. The paper presents future changes in temperature, precipitation and humidity and their direct and indirect potential impacts on human health in the coastal regions of the Gulf countries including Yemen, Oman, United Arab Emirates, Qatar, and Bahrain. The analysis is based on the long-term changes in the values of temperature, precipitation and humidity as predicted by the global climatic simulation models under different scenarios of GHG emission levels. Monthly data on temperature, precipitation, and humidity were retrieved from IPCC databases for longitude 41.25 degrees E to 61.875 degrees E and latitude 9.278 degrees N to 27.833 degrees N. Using an average of 1970 to 2000 values as baseline, the changes in the humidity, temperature and precipitation were predicted for the period 2020 to 2050 and 2070 to 2099. Based on epidemiological studies on various diseases associated with the change in temperature, humidity and precipitation in arid and hot regions, empirical models were developed to assess human health risk in the Gulf region to predict elevated levels of diseases and mortality rates under different emission scenarios as developed by the IPCC.The preliminary assessment indicates

  11. The 5 key questions coping with risks due to natural hazards, answered by a case study

    Science.gov (United States)

    Hardegger, P.; Sausgruber, J. T.; Schiegg, H. O.

    2009-04-01

    Based on Maslow's hierarchy of needs, human endeavours concern primarily existential needs, consequently, to be safeguarded against both natural as well as man made threads. The subsequent needs are to realize chances in a variety of fields, as economics and many others. Independently, the 5 crucial questions are the same as for coping with risks due to natural hazards specifically. These 5 key questions are I) What is the impact in function of space and time ? II) What protection measures comply with the general opinion and how much do they mitigate the threat? III) How can the loss be adequately quantified and monetized ? IV) What budget for prevention and reserves for restoration and compensation are to be planned ? V) Which mix of measures and allocation of resources is sustainable, thus, optimal ? The 5 answers, exemplified by a case study, concerning the sustainable management of risk due to the debris flows by the Enterbach / Inzing / Tirol / Austria, are as follows : I) The impact, created by both the propagation of flooding and sedimentation, has been forecasted by modeling (numerical simulation) the 30, 50, 100, 150, 300 and 1000 year debris flow. The input was specified by detailed studies in meteorology, precipitation and runoff, in geology, hydrogeology, geomorphology and slope stability, in hydraulics, sediment transport and debris flow, in forestry, agriculture and development of communal settlement and infrastructure. All investigations were performed according to the method of ETAlp (Erosion and Transport in Alpine systems). ETAlp has been developed in order to achieve a sustainable development in alpine areas and has been evaluated by the research project "nab", within the context of the EU-Interreg IIIb projects. II) The risk mitigation measures of concern are in hydraulics at the one hand and in forestry at the other hand. Such risk management is evaluated according to sustainability, which means economic, ecologic and social, in short, "triple

  12. An experimental investigation of composite floor vibration due to human activities. A case study

    Directory of Open Access Journals (Sweden)

    Yasser G. Mohamed Fahmy

    2012-12-01

    Full Text Available Composite steel floor decks are used in a large variety of constructions with long spans, such as administration and commercial buildings, hotels and bridges. Due to decreased floor mass and longer span lengths, floor vibrations have become an area of concern. Floor decks with low frequencies may be in resonance with the vibrations due to human activities and the resulting acceleration may exceed human comfort levels. The design of slender floor structures, with steel or composite cross sections, is often limited by the serviceability criteria such as deflection limits and vibration behavior, rather than the strength criteria. Control of deflections under AISC specifications requirement is not enough to satisfy the serviceability requirements of the floor systems for vibration. In addition, vibration analysis procedures introduced by AISC design Guide No. 11 are based on regularly-shaped structures and simple boundary conditions. In this paper, a case study for full scale testing of a composite floor system proposed for a tower at Kuwait state that was tested prior to construction. The heel-drop and walking tests are performed on floor systems with and without raised floor respectively. Since heel-drop and walking test results would vary in light of person performance, both tests are carried out three or four times to reduce uncertainty. The fundamental frequencies and damping ratio of the floor system are measured. Comparison of the experimental results with results based on the AISC hand calculations shows that there is no significant difference; therefore the results based on AISC are generally acceptable.

  13. Effect of prolotherapy on hemiplegic shoulder pain due to rotator cuff tendinopathy: a pilot study

    Directory of Open Access Journals (Sweden)

    Serdar Kesikburun

    2017-03-01

    Full Text Available Purpose: The aim of this study was to investigate the effect of prolotherapy on pain and shoulder range of motion in stroke patients with hemiplegic shoulder pain due to rotator cuff tendinopathy. Material and Methods: The data of 10 patients (mean age, 64.2+/-11.6 years who had a history stroke of more than six months and underwent prolotherapy treatment were collected retrospectively. The treatment included 3 sessions of dextrose pr olotherapy injections applied to rotator cuff tendon. Visual analogue scale pain scores and shoulder range of motions measured at baseline and two weeks later after end of the treatment were assessed. Results: Visual analogue scale shoulder pain scores of the patients decreased from 8.2+/-1.1 at baseline to 4.8+/-1.9 after prolotherapy The degrees of shoulder flexion and abduction increased significantly after the treatment. Conclusion: Preliminary results in this pilot study suggested the beneficial effect of proloterapi in the treatmentof hemiplegicshoulderpain. [Cukurova Med J 2017; 42(1.000: 13-18

  14. [Responsibility due to medication errors in France: a study based on SHAM insurance data].

    Science.gov (United States)

    Theissen, A; Orban, J-C; Fuz, F; Guerin, J-P; Flavin, P; Albertini, S; Maricic, S; Saquet, D; Niccolai, P

    2015-03-01

    The safe medication practices at the hospital constitute a major public health problem. Drug supply chain is a complex process, potentially source of errors and damages for the patient. SHAM insurances are the biggest French provider of medical liability insurances and a relevant source of data on the health care complications. The main objective of the study was to analyze the type and cause of medication errors declared to SHAM and having led to a conviction by a court. We did a retrospective study on insurance claims provided by SHAM insurances with a medication error and leading to a condemnation over a 6-year period (between 2005 and 2010). Thirty-one cases were analysed, 21 for scheduled activity and 10 for emergency activity. Consequences of claims were mostly serious (12 deaths, 14 serious complications, 5 simple complications). The types of medication errors were a drug monitoring error (11 cases), an administration error (5 cases), an overdose (6 cases), an allergy (4 cases), a contraindication (3 cases) and an omission (2 cases). Intravenous route of administration was involved in 19 of 31 cases (61%). The causes identified by the court expert were an error related to service organization (11), an error related to medical practice (11) or nursing practice (13). Only one claim was due to the hospital pharmacy. The claim related to drug supply chain is infrequent but potentially serious. These data should help strengthen quality approach in risk management. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  15. Apical force distribution due to orthodontic forces: a finite element study.

    Science.gov (United States)

    Mathur, Anirudh K; Gupta, Vikas; Sarmah, Anirban; Pai, Vinaya S; Chandrashekar, G

    2011-03-01

    This finite element study was conducted to calculate the distribution of stresses in the periodontal ligament when various orthodontic forces were applied, with emphasis on the effect on root apex. An in vitro finite element method was used to construct a three-dimensional finite element model of a maxillary central incisor, its periodontal ligament and alveolar bone was constructed on the basis of average anatomic morphology. To this model, five types of orthodontic forces namely tipping, bodily movement, intrusion, extrusion and rotations were applied at various points on the crown of the tooth model. After the application of the forces, initial stress and initial displacements of the periodontal ligament were evaluated. The principal stress obtained on the periodontal ligament due to various orthodontic loadings on the maxillary central incisor was analyzed using ANSYS 10 finite element software. It showed that the greatest amount of relative stress at the apex of maxillary central incisor occurred with intrusion, extrusion and rotation. Bodily movement and tipping forces produce stress concentrated at the alveolar crest and not at the root apex. Clinical implications of this study suggest that if the clinician is concerned about placing heavy stresses on the root apex, then vertical and rotational forces must be applied with caution. If heavy stresses are to be placed on the root apex, then vertical and rotational forces must be applied with caution during orthodontic therapy.

  16. Quantitative changes in skin composition parameters due to chemotherapy in breast cancer patients: a cohort study.

    Science.gov (United States)

    Kang, Danbee; Kim, Im-Ryung; Im, Young Hyuck; Park, Yeon Hee; Ahn, Jin Seok; Lee, Jeong Eon; Nam, Seok Jin; Park, Hyeokgon; Kim, Eunjoo; Lee, Hae Kwang; Lee, Dong-Youn; Cho, Juhee

    2015-08-01

    The objective of this study is to evaluate objective changes in water content, sebum content, transepidermal water loss (TEWL), and melanin due to breast cancer chemotherapy, and their association with subjective symptoms. Prospective cohort study of 61 patients 18 years of age or older with a postoperative diagnosis of stage I-III breast cancer, who received adjuvant chemotherapy between February and September 2012 at an outpatient breast cancer clinic in Korea. Objective skin parameters, measured using a noninvasive bioengineering device, and patient-reported dryness and dullness were assessed before chemotherapy, after two cycles of chemotherapy, and 1, 3, and 6 months after completion of chemotherapy. Water content (-6.5 %), sebum (-75.5 %), and TEWL (-22.4 %) significantly decreased during chemotherapy compared to pre-chemotherapy levels (all p values skin changes were similar in patients with or without hormone therapy. Most of patients reported dryness (57.9 %) and dullness (49.1 %) after chemotherapy, and patient-reported dryness was significantly associated with decreased sebum content. Chemotherapy-induced substantial changes in objective skin composition parameters. These changes persisted after 6 months from completion of chemotherapy and were associated with patient-reported symptoms. Additional research is needed to translate these findings into interventions for improving the dermatologic quality of life of breast cancer patients undergoing chemotherapy.

  17. Study of Intrinsic Dissipation Due to Thermoelastic Coupling in Gyroscope Resonators.

    Science.gov (United States)

    Li, Changlong; Gao, Shiqiao; Niu, Shaohua; Liu, Haipeng

    2016-01-01

    This paper presents analytical models, as well as numerical and experimental verification of intrinsic dissipation due to thermoelastic loss in tuning-fork resonator. The thermoelastic analytical governing equations are created for resonator vibrating at drive-mode and sense-mode, and thermoelastic vibration field quantities are deduced. Moreover, the theoretical values are verified that coincided well with finite element analysis (FEM) simulation results. Also, the comparison of vibration field quantities is made to investigate the effect of different conditions on resonator thermoelastic vibration behavior. The significant parameters of thermoelastic damping and quality factor are subsequently deduced to analyze the energy dissipation situation in the vibration process. Meanwhile, the corresponding conclusions from other studies are used to verify our theoretical model and numerical results. By comparing with the experimental quality factor, the numerical values are validated. The combination of the theoretical expressions, numerical results and experimental data leads to an important insight into the achievable quality factor value of tuning-fork resonator, namely, that the thermoelastic damping is the main loss mechanism in the micro-comb finger structure and the quality factor varies under different vibration modes. The results demonstrate that the critical geometry dimensions of tuning-fork resonator can be well designed with the assistance of this study.

  18. Study of epidemiological risk of lung cancer in Mexico due indoor radon exposure

    Science.gov (United States)

    Ángeles, A.; Espinosa, G.

    2014-07-01

    In this work the lifetime relative risks (LRR) of lung cancer due to exposure to indoor 222Rn on the Mexican population is calculated. Cigarette smoking is the number one risk factor for lung cancer (LC), because that, to calculate the number of cases of LC due to exposure to 222Rn is necessary considers the number of cases of LC for smoking cigarette. The lung cancer mortality rates published by the "Secretaría de Salud" (SSA), the mexican population data published by the "Consejo Nacional de Población" (CONAPO), smoking data in the mexican population, published by the "Comisión Nacional Contra las Adicciones" (CONADIC), the "Organización Panamericana de la Salud" (OPS) and indoor 222Rn concentrations in Mexico published in several recent studies are used. To calculate the lifetime relative risks (LRR) for different segments of the Mexican population, firstly the Excess Relative Risk (ERR) is calculated using the method developed by the BEIR VI committee and subsequently modified by the USEPA and published in the report "EPA Assessment of Risks from Radon in Homes". The excess relative risks were then used to calculate the corresponding lifetime relative risks, again using the method developed by the BEIR VI committee. The lifetime relative risks for Mexican male and female eversmokers and Mexican male and female never-smokers were calculated for radon concentrations spanning the range found in recent studies of indoor radon concentrations in Mexico. The lifetime relative risks of lung cancer induced by lifetime exposure to the mexican average indoor radon concentration were estimated to be 1.44 and 1.40 for never-smokers mexican females and males respectively, and 1.19 and 1.17 for ever-smokers Mexican females and males respectively. The Mexican population LRR values obtained in relation to the USA and Canada LRR published values in ever-smokers for both gender are similar with differences less than 4%, in case of never-smokers in relation with Canada

  19. Selection Bias Due to Loss to Follow Up in Cohort Studies.

    Science.gov (United States)

    Howe, Chanelle J; Cole, Stephen R; Lau, Bryan; Napravnik, Sonia; Eron, Joseph J

    2016-01-01

    Selection bias due to loss to follow up represents a threat to the internal validity of estimates derived from cohort studies. Over the past 15 years, stratification-based techniques as well as methods such as inverse probability-of-censoring weighted estimation have been more prominently discussed and offered as a means to correct for selection bias. However, unlike correcting for confounding bias using inverse weighting, uptake of inverse probability-of-censoring weighted estimation as well as competing methods has been limited in the applied epidemiologic literature. To motivate greater use of inverse probability-of-censoring weighted estimation and competing methods, we use causal diagrams to describe the sources of selection bias in cohort studies employing a time-to-event framework when the quantity of interest is an absolute measure (e.g., absolute risk, survival function) or relative effect measure (e.g., risk difference, risk ratio). We highlight that whether a given estimate obtained from standard methods is potentially subject to selection bias depends on the causal diagram and the measure. We first broadly describe inverse probability-of-censoring weighted estimation and then give a simple example to demonstrate in detail how inverse probability-of-censoring weighted estimation mitigates selection bias and describe challenges to estimation. We then modify complex, real-world data from the University of North Carolina Center for AIDS Research HIV clinical cohort study and estimate the absolute and relative change in the occurrence of death with and without inverse probability-of-censoring weighted correction using the modified University of North Carolina data. We provide SAS code to aid with implementation of inverse probability-of-censoring weighted techniques.

  20. A CLINICAL STUDY TO ANALYSE THE SPECTRUM OF PERITONITIS DUE TO HOLLOW VISCUS PERFORATION

    Directory of Open Access Journals (Sweden)

    Sai Datta

    2015-07-01

    Full Text Available Perforation peritonitis is the one of the common abdominal surgical emergency . The spectrum of etiology of perforation in Tropical countries continues to be different from its Western counterpart. The objective of the study was to highlight the spectrum of perforation peritonitis as encountered at K aturi M edical C ollege and H ospital , G untur. A.P. Hundred consec utive cases of perforation peritonitis over a period of 26 months . (June 2010 - July 2012 were reviewed in terms of clinical presentation, operative findings and postoperative course retrospectively. The most common type of perforation in our series was per forated duodenal ulcer (56 cases followed by Appendicular (16 cases, Ileal (12 cases, Colonic ( 6 cases, Gastric ( 4 cases, Jejunal (2 cases, Gall bladder (2 cases, Anastomotic ulcer ( 2 cases were reported . Despite delay in seeking medical treatment (32%, the overall mortality (11% , favorably comparable with other published series though the overall morbidity (29% was favorable. In contrast to western literature, where lower gastrointestinal tract perforations predominate, upper gastrointestinal tr act perforations constitute the majority of cases in India. Mostly males and elderly people are affected due to injudicious usage of NSAIDS, alcohol, smoking. ( 11 Withdrawal from these habits and using of proton pump inhibitors and H - Pylori eradication which warrant early recognition and prompt treatment to avoid serious complications and death.

  1. Environmental health aspects of drinking water-borne outbreak due to karst flooding: case study.

    Science.gov (United States)

    Dura, Gyula; Pándics, Tamás; Kádár, Mihály; Krisztalovics, Katalin; Kiss, Zoltánné; Bodnár, Judit; Asztalos, Agnes; Papp, Erzsébet

    2010-09-01

    Climate change may increase the incidence of waterborne diseases due to extreme rainfall events, and consequent microbiological contamination of the water source and supply. As a result of the complexity of the pathways from the surface to the consumer, it is difficult to detect an association between rainfall and human disease. The water supply of a Hungarian city, Miskolc (174,000 inhabitant), is mainly based on karstic water, a vulnerable underground water body. A large amount of precipitation fell on the catchment area of the karstic water source, causing an unusually strong karstic water flow and flooding, and subsequent microbiological contamination. The presence of several potential sources of contamination in the protective zone of the karstic water source should be emphasized. The water supplier was unprepared to treat the risk of waterborne outbreak caused by an extreme weather event. Public health intervention and hygienic measures were taken in line with epidemiological actions, focusing on the protection of consumers by providing safe drinking water. The contamination was identified, and measures were taken for risk reduction and prevention. This case study underlines the increasing importance of preparedness for extreme water events in order to protect the karstic water sources and to avoid waterborne outbreaks.

  2. Recovery of atrophic leg muscles in the hemiplegics due to cerebrovascular accidents. Computed tomographic study

    Energy Technology Data Exchange (ETDEWEB)

    Odajima, Natsu; Ishiai, Sumio; Okiyama, Ryouichi; Furukawa, Tetsuo; Tsukagoshi, Hiroshi.

    1988-02-01

    Thirty-five patients with hemiplegia due to cerebrovascular accidents were studied with regared to the muscle wastings before and after rehabilitation training. Hemiplegics were composed of 12 improved and 23 non-improved patients. The CT scan was carried out at the midportion of the thigh and largest-diameter section of the calf. Muscle size of each cross-sectional area was measured on CT image and the increase of size (..delta..S) in each muscle after training was calculated. The ..delta..S of quadriceps femoris was correlated with that of whole cross-section of the thigh. The gracilis in non-affected side was not correlated with that of whole muscles. In both legs, there was an increase in leg muscle size after training. These changes were nost marked in the non-affected side of the improved patients. After training the difference between the two limbs remained unchanged. Recovery of muscle wasting in both legs was seen first in the quadriceps in thigh and flexors in calf. Gracilis was relatively unchanged in comparison with other muscles. Remarkable increase of muscle size in non-affected side was worthwhile to note.

  3. STUDY REGARDING THE SUCCESSFUL MANAGEMENT PRACTICE AND THE CHANGES IN MANAGEMENT APPROACH DUE TO FINANCIAL CRISIS

    Directory of Open Access Journals (Sweden)

    Natalia Silaş

    2013-04-01

    Full Text Available Modern management involves a wide range of skills and knowledge, many of which assuming skills in social sciences, logics, philosophy, psychology, mathematics, statistics, information technology, international relations, languages and culture. There is no universal management style to be effective, but all factors need to be analyzed in a given situation and then to be chosen a person with a style to suit the situation and capable to train people to meet the requirements. The present study intends to analyze the management practices that determine the success in business, as well as the changes that occur in the management approach due to the financial crisis. In this respect, the research takes into consideration two reference periods, the year 2007, a year of great economic growth, which precedes the financial crisis, and the year 2012, year in which the consequences of the financial crisis exist in a great extent in all social economic fields. The criteria considered are ranked based on a sample of data obtained by interviewing the managers of 290 companies that have successfully overcome problems caused by the crisis. Are highlighted in the paper the most important methods of management that, according to the surveyed managers, can help the company to overcome the difficulties generated by influence of national and international environment.

  4. An Experimental Study of the Noise Due to Traffic in a Congested Urban Area

    Science.gov (United States)

    Sangeetha, M.; Sankar, P.

    2016-03-01

    Noise pollution in an urban environment is an issue of serious concern in the major cities of India. There are various factors that contribute to the increase of noise levels in urban areas. The intensity of traffic is one of the factors which contributes to a drastic increase in environmental noise. The management of noise pollution has to be considered in the decision making process. In this paper, an attempt is made to study the existing noise level due to the traffic in Velachery which is declared as a sensitive area by the Ministry of Environment and Forestry (MoEF). The noise level data is collected using the MS6710 digital sound meter. The Custic simulation software version 3.2 is used for finding the propagation of noise. The spatial patterns of measurement were also calculated, in the sub-urban area of Velachery, Chennai, Tamilnadu, India. A means of transmitting this data to vehicles moving in the area, through a wireless medium is simulated using NCTUns 6.0 (network simulator), to enable drivers to understand the environmental conditions. A hardware was also designed which can be used to transmit and receive the noise data using the Zigbee module. A noise transmitting station is placed at a junction, so that it can transmit this noise data to the receivers which are fitted inside the vehicles.

  5. Quantitative Study of Thermal Disturbances Due to Nonuniformly Perfused Tumors in Peripheral Regions of Women's Breast.

    Science.gov (United States)

    Makrariya, Akshara; Adlakha, Neeru

    2017-01-01

    Mathematical modeling of biothermal processes is widely used to enhance the quantitative understanding of thermoregulation system of human body organs. This quantitative knowledge of thermal information of various human body organs can be used for developing clinical applications. In the past, investigators have studied thermal distribution in hemisphere-shaped human breast in the presence of sphere-shaped tumor. The shape and size of the breast as well as tumor may also affect thermal distribution which can have serious implications in thermography. In this article, a model of thermal disturbances in peripheral regions of ellipsoid-shaped human breast involving ellipse-shaped nonuniformly perfused tumor has been developed for a 2-dimensional steady-state case. The modeling study will provide biomedical scientists vital insights of thermal changes occurring due to the shape and size of breast and tumor which can influence the development of protocols of thermography for diagnosis of tumors in women's breast. We have incorporated the significant parameters such as blood flow, metabolic activity, and thermal conductivity in the thermal model for normal and malignant tissues. The controlled metabolic activity has been incorporated for normal tissues, and uncontrolled metabolic activity has been incorporated for tumor regions. The peripheral regions of breast are divided into 3 major layers, namely, epidermis, dermis, and subdermal tissues. An ellipse-shaped nonuniformly perfused tumor is assumed to be present in dermal layers. The nonuniformly perfused tumor is divided into 2 natural components, namely, the necrotic core and tumor periphery. The outer surface of the breast is assumed to be exposed to the environment, and the heat loss takes place by conduction, convection, radiation, and evaporation. The finite element approach is used to obtain the solution. The numerical results have been used to study the effect of shape and size of tumor on temperature

  6. Multicenter clinical study on Fuzhenghuayu capsule against liver fibrosis due to chronic hepatitis B

    Institute of Scientific and Technical Information of China (English)

    Ping Liu; Mo-Bin Wan; Xiong Cai; Zhi-Qing Zhang; Jun Ye; Ren-Xing Zhou; Jia He; Bao-Zhang Tang; Yi-Yang Hu; Cheng Liu; Lie-Ming Xu; Cheng-Hai Liu; Ke-Wei Sun; De-Chang Hu; You-Kuan Yin; Xia-Qiu Zhou

    2005-01-01

    AIM: To study the efficacy and safety of Fuzhenghuayu capsule (FZHY capsule, a capsule for strengthening body resistance to remove blood stasis) against liver fibrosis due to chronic hepatitis B. METHODS: Multicenter, randomized, double blinded and parallel control experiment was conducted in patients (aged from 18 to 65 years) with liver fibrosis due to chronic hepatitis B. Hepatic histologic changes and HBV markers were examined at wk 0 and 24 during treatment. Serologic parameters (HA, LM, P-Ⅲ-P, Ⅳ-C) were determined and B ultrasound examination of the spleen and liver was performed at wk 0, 12 and 24. Liver function (liver function and serologic parameters for liver fibrosis) was observedat wk 0, 6, 12, 18 and 24. Blood and urine routine test, renal function and ECG were examined before and after treatment. RESULTS: There was no significant difference between experimental group (110 cases) and control group (106 cases) in demographic features, vital signs, course of illness, history for drug anaphylaxis and previous therapy, liver function, serologic parameters for liver fibrosis, liver histologic examination (99 cases in experimental group, 96 cases in control group), HBV markers, and renal function. According to the criteria for liver fibrosis staging, meanscore of fibrotic stage(s) in experimental group after treatment (1.80) decreased significantly compared to the previous treatment (2.33, P<0.05), but there was no significant difference in mean score of fibrotic stage(s) (2.11 and 2.14 respectively). There was a significant difference in reverse rate between experimental group (52%) and control group (23.3%) in liver biopsy. With marked effect on decreasing the mean value of inflammatory activity and score of inflammation (P<0.05), Fuzhenghuayu capsule had rather good effects on inhibiting inflammatory activity and was superior to that of Heluoshugan capsule. Compared to that of pretreatment, there was a significant decrease in HA, LM, P-Ⅲ-P and

  7. HOSPITALIZATIONS DUE TO ADVERSE DRUG EVENTS IN THE ELDERLY – A RETROSPECTIVE REGISTER STUDY

    Directory of Open Access Journals (Sweden)

    Outi Laatikainen

    2016-10-01

    Full Text Available Adverse drug events (ADEs are more likely to affect geriatric patients due to physiological changes occurring with aging. Even though this is an internationally recognized problem, similar research data in Finland is still lacking. The aim of this study was to determine the number of geriatric medication-related hospitalizations in the Finnish patient population and to discover the potential means of recognizing patients particularly at risk of ADEs. The study was conducted retrospectively from the 2014 emergency department patient records in Oulu University Hospital. A total number of 290 admissions were screened for ADEs, adverse drug reactions (ADRs and drug-drug interactions (DDIs by a multi-disciplinary research team. Customized Naranjo scale was used as a control method. All admissions were categorized into ‘probable’, ‘possible’, or ‘doubtful’ by both assessment methods. In total, 23.1% of admissions were categorized as ‘probably’ or ‘possibly’ medication-related. Vertigo, falling, and fractures formed the largest group of ADEs. The most common ADEs were related to medicines from N class of the ATC-code system. Age, sex, residence, or specialty did not increase the risk for medication-related admission significantly (min p= 0.077. Polypharmacy was, however, found to increase the risk (OR 3,3; 95% CI, 1.5-6.9 p = 0.01. In conclusion, screening patients for specific demographics or symptoms would not significantly improve the recognition of ADEs. In addition, as ADE detection today is largely based on voluntary reporting systems and retrospective manual tracking of errors, it is evident that more effective methods for ADE detection are needed in the future.

  8. A study on variation in position of an Indian station due to solid earth tides

    Indian Academy of Sciences (India)

    Jayanta Kumar Ghosh; Shray Pathak

    2015-04-01

    In many geodetic analyses, it is important to consider the effect of earth tide on the instantaneous position of a station and its subsequent influence on the computation and interpretation of time series of coordinates as well as related data products. The tidal effect and temporal variations in the position of the IGS (International Global Navigational Satellite Systems [GNSS] Service) stations at Hyderabad (India), Ankara (Turkey) and Beijing Fangshan (China), due to solid earth tides has been studied. Surface tidal displacement of the station has been computed on daily basis for a month, based on the concept of gravity. Further, mean daily coordinates of the station been computed using static precise point positioning (PPP) method for a month. Results show that the station undergoes temporal displacements and its coordinates vary continuously within a day and all the days in the month. The maximum range in vertical displacement of the station has been found to be about 48 cm in a day over a period of a month and that along the north and east directions is respectively 8 cm and 14 cm. This is the maximum range but the mean value in the vertical displacement is 6 cm and along north and east is 1.7 cm and 0.09 cm, respectively. The ranges in variation in the mean value of geodetic latitude, longitude, and height of the station have been found to be 1.23, 2.73, and 3.52 cm, respectively. Further, it has been found that the tidal oscillations follow some periodicity, and thus need to be studied independently for all stations.

  9. Latarjet Procedure for Anterior Shoulder Instability Due to Tramadol-Induced Seizures: A Multicenter Study.

    Science.gov (United States)

    Khater, Ahmad Hany; Sobhy, Mohamed H; Said, Hatem G; Kandil, Ahmed; Reda, Walid; Seifeldin, Ahmed Fouad; Moustafa, Ramez; Elassal, Maher A; Kamel, Ezzat M

    2016-04-01

    Seizures, commonly due to epilepsy, are known to cause shoulder instability. Tramadol addiction has recently been found to induce seizures in patients who exceed the recommended dose. Because of the easy accessibility and low cost of tramadol, an increasingly alarming phenomenon of tramadol abuse has been demonstrated in recent years. The purpose of this multicenter study was to investigate shoulder instability resulting from tramadol-induced seizure (TIS) as well as to recommended management for such shoulder instability. The hypothesis was that TIS leads to anterior shoulder dislocations with major bony defects, which favors bony reconstructive procedures as a suitable method of treatment. Case series; Level of evidence, 4. This prospective case series study was conducted on 73 patients (78 shoulders) who presented with anterior shoulder dislocations and a clear history of tramadol abuse. The mean age of the patients was 26.8 years, and the mean number of dislocations was 14. The mean duration of addiction was 17 months, with a mean dose of 752 mg of tramadol hydrochloride per day. Glenoid and humeral bone loss ranged from 15% to 35% and from 15% to 40%, respectively. The mean follow-up period was 28 months. All patients underwent an open Latarjet procedure. Postoperative mean Rowe score and American Shoulder and Elbow Surgeons score at final follow-up (24 months) improved significantly from 20 to 84 and from 44 to 91, respectively (P Latarjet procedure is recommended for these patients, after control of addiction, and provides 95% satisfaction at midterm follow-up. © 2016 The Author(s).

  10. Hospitalizations Due to Adverse Drug Events in the Elderly—A Retrospective Register Study

    Science.gov (United States)

    Laatikainen, Outi; Sneck, Sami; Bloigu, Risto; Lahtinen, Minna; Lauri, Timo; Turpeinen, Miia

    2016-01-01

    Adverse drug events (ADEs) are more likely to affect geriatric patients due to physiological changes occurring with aging. Even though this is an internationally recognized problem, similar research data in Finland is still lacking. The aim of this study was to determine the number of geriatric medication-related hospitalizations in the Finnish patient population and to discover the potential means of recognizing patients particularly at risk of ADEs. The study was conducted retrospectively from the 2014 emergency department patient records in Oulu University Hospital. A total number of 290 admissions were screened for ADEs, adverse drug reactions (ADRs) and drug-drug interactions (DDIs) by a multi-disciplinary research team. Customized Naranjo scale was used as a control method. All admissions were categorized into “probable,” “possible,” or “doubtful” by both assessment methods. In total, 23.1% of admissions were categorized as “probably” or “possibly” medication-related. Vertigo, falling, and fractures formed the largest group of ADEs. The most common ADEs were related to medicines from N class of the ATC-code system. Age, sex, residence, or specialty did not increase the risk for medication-related admission significantly (min p = 0.077). Polypharmacy was, however, found to increase the risk (OR 3.3; 95% CI, 1.5–6.9; p = 0.01). In conclusion, screening patients for specific demographics or symptoms would not significantly improve the recognition of ADEs. In addition, as ADE detection today is largely based on voluntary reporting systems and retrospective manual tracking of errors, it is evident that more effective methods for ADE detection are needed in the future. PMID:27761112

  11. 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

  12. Colon Necrosis Due to Sodium Polystyrene Sulfonate with and without Sorbitol: An Experimental Study in Rats

    Science.gov (United States)

    Ayoub, Isabelle; Oh, Man S.; Gupta, Raavi; McFarlane, Michael; Babinska, Anna; Salifu, Moro O.

    2015-01-01

    Introduction Based on a single rat study by Lillemoe et al, the consensus has been formed to implicate sorbitol rather than sodium polystyrene sulfonate (SPS) as the culprit for colon necrosis in humans treated with SPS and sorbitol. We tested the hypothesis that colon necrosis by sorbitol in the experiment was due to the high osmolality and volume of sorbitol rather than its chemical nature. Methods 26 rats underwent 5/6 nephrectomy. They were divided into 6 groups and given enema solutions under anesthesia (normal saline, 33% sorbitol, 33% mannitol, SPS in 33% sorbitol, SPS in normal saline, and SPS in distilled water). They were sacrificed after 48 hours of enema administration or earlier if they were very sick. The gross appearance of the colon was visually inspected, and then sliced colon tissues were examined under light microscopy. Results 1 rat from the sorbitol and 1 from the mannitol group had foci of ischemic colonic changes. The rats receiving SPS enema, in sorbitol, normal saline, distilled water, had crystal deposition with colonic necrosis and mucosal erosion. All the rats not given SPS survived until sacrificed at 48 h whereas 11 of 13 rats that received SPS in sorbitol, normal saline or distilled water died or were clearly dying and sacrificed sooner. There was no difference between sorbitol and mannitol when given without SPS. Conclusions In a surgical uremic rat model, SPS enema given alone or with sorbitol or mannitol seemed to cause colon necrosis and high mortality rate, whereas 33% sorbitol without SPS did not. PMID:26413782

  13. Study of thermal influence on tubes due to sodium-water reactions in LMFBR steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, H.; Kurihara, A.; Nishimura, M. [Japan Nuclear Cycle Development Institute, Ibaraki (Japan)

    2004-07-01

    A study of thermal influence on heat-transfer tubes in sodium-water reactions is carried out to evaluate the tube rupture due to overheating in the water leak accident of an LMFBR steam generator (SG). By assuming the sodium-water reaction jet to be a two-phase flow that consists of sodium and hydrogen, the heat-transfer characteristics are examined and a simple model of effective heat-transfer coefficient (HTC) is proposed for the safety evaluation of the SG. Comparison of the model with experimental data leads to the following conclusions: An upper limit exists in the HTC between reaction jet and tube wall, and it is equivalent in approximation to the HTC of single-phase sodium flow. The HTC can be written in simple form as functions of the HTC of single-phase sodium flow, void fraction and temperatures of sodium, hydrogen and tube wall. Hydrogen provides negligible heating effect, so that the apparent HTC would decrease with increase of the hydrogen temperature that can readily surpass that of sodium. The outer-surface temperature of tube wall would not rise so high beyond the temperature of sodium that is excellent in heat-transfer characteristics, even if tube wall is exposed to the high-temperature hydrogen. The transient heat conduction analysis with the mean value of the data can appropriately evaluate the outer-surface temperature of tube wall by the metallographic observation, while the analysis with the maximum value can conservatively evaluate the tube wall temperature. (authors)

  14. Assessing the extent of colon lengthening due to splenic flexure mobilization techniques: a cadaver study

    Directory of Open Access Journals (Sweden)

    Sergio Eduardo Alonso Araujo

    2012-09-01

    Full Text Available CONTEXT: Failure of a colorectal anastomosis represents a life-threatening complication of colorectal surgery. Splenic flexure mobilization may contribute to reduce the occurrence of anastomotic complications due to technical flaws. There are no published reports measuring the impact of splenic flexure mobilization on the length of mobilized colon viable to construct a safe colorectal anastomosis. OBJECTIVE: The aim of the present study was to determine the effect of two techniques for splenic flexure mobilization on colon lengthening during open left-sided colon surgery using a cadaver model. DESIGN: Anatomical dissections for left colectomy and colorectal anastomosis at the sacral promontory level were conducted in 20 fresh cadavers by the same team of four surgeons. The effect of partial and full splenic flexure mobilization on the extent of mobilized left colon segment was determined. SETTING: University of Sao Paulo Medical School, Sao Paulo, SP, Brazil. Tertiary medical institution and university hospital. PARTICIPANTS: A team of four surgeons operated on 20 fresh cadavers. RESULTS: The length of resected left colon enabling a tension-free colorectal anastomosis at the level of sacral promontory achieved without mobilizing the splenic flexure was 46.3 (35-81 cm. After partial mobilization of the splenic flexure, an additionally mobilized colon segment measuring 10.7 (2-30 cm was obtained. After full mobilization of the distal transverse colon, a mean 28.3 (10-65 cm segment was achieved. CONCLUSION: Splenic flexure mobilization techniques are associated to effective left colon lengthening for colorectal anastomosis. This result may contribute to decision-making during rectal surgery and low colorectal and coloanal anastomosis.

  15. Quantifying Unnecessary Normal Tissue Complication Risks due to Suboptimal Planning: A Secondary Study of RTOG 0126

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Kevin L., E-mail: kevinmoore@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Schmidt, Rachel [Department of Physics, Fort Hays State University, Hays, Kansas (United States); Moiseenko, Vitali [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Olsen, Lindsey A.; Tan, Jun [Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri (United States); Xiao, Ying; Galvin, James [Thomas Jefferson University Hospital, Philadelphia, Pennsylvania (United States); Pugh, Stephanie [NRG Oncology Statistics and Data Management Center, Philadelphia, Pennsylvania (United States); Seider, Michael J. [Akron City Hospital, Akron, Ohio (United States); Dicker, Adam P. [Thomas Jefferson University Hospital, Philadelphia, Pennsylvania (United States); Bosch, Walter; Michalski, Jeff; Mutic, Sasa [Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri (United States)

    2015-06-01

    predicted NTCP reductions while maintaining the volume of the PTV receiving prescription dose. An equivalent sample of high-quality plans showed fewer toxicities than low-quality plans, 6 of 73 versus 10 of 73 respectively, although these differences were not significant (P=.21) due to insufficient statistical power in this retrospective study. Conclusions: Plan quality deficiencies in RTOG 0126 exposed patients to substantial excess risk for rectal complications.

  16. Experimental study of geo-acoustic inversion uncertainty due to ocean sound-speed fluctuations.

    NARCIS (Netherlands)

    Siderius, M.; Nielsen, P.L.; Sellschopp, J.; Snellen, M.; Simons, D.G.

    2001-01-01

    Acoustic data measured in the ocean fluctuate due to the complex time-varying properties of the channel. When measured data are used for model-based, geo-acoustic inversion, how do acoustic fluctuations impact estimates for the seabed properties? In May 1999 SACLANT Undersea Research Center and

  17. Experimental study of geo-acoustic inversion uncertainty due to ocean sound-speed fluctuations.

    NARCIS (Netherlands)

    Siderius, M.; Nielsen, P.L.; Sellschopp, J.; Snellen, M.; Simons, D.G.

    2001-01-01

    Acoustic data measured in the ocean fluctuate due to the complex time-varying properties of the channel. When measured data are used for model-based, geo-acoustic inversion, how do acoustic fluctuations impact estimates for the seabed properties? In May 1999 SACLANT Undersea Research Center and TNO-

  18. Epidemiology of injuries due to tropical cyclones in Hong Kong: a retrospective observational study.

    Science.gov (United States)

    Rotheray, K R; Aitken, P; Goggins, W B; Rainer, T H; Graham, C A

    2012-12-01

    Tropical cyclones are huge circulating masses of wind which form over tropical and sub-tropical waters. They affect an average of 78 million people each year. Hong Kong is a large urban centre with a population of just over 7 million which is frequently affected by tropical cyclones. We aimed to describe the numbers and types of injuries due to tropical cyclones in Hong Kong, as well as their relation to tropical cyclone characteristics. The records of all patients presenting to Hong Kong's public hospital emergency departments from 1st January 2004 to 31st December 2009 with tropical cyclone related injuries were reviewed and information regarding patient and injury characteristics was collected. Meteorological records for the relevant periods were examined and data on wind speed, rainfall and timing of landfall and warning signals was recorded and compared with the timing of tropical cyclone related injuries. A total of 460 tropical cyclone related injuries and one fatality across 15 emergency departments were identified during the study period. The mean age of those injured was 48 years and 48% were female. 25.4% of injuries were work related. The head (33.5%) and upper limb (32.5%) were the most commonly injured regions, with contusions (48.6%) and lacerations (30.2%) being the most common injury types. Falls (42.6%) were the most common mechanism of injury, followed by being hit by a falling or flying object (22.0%). In univariable analysis the relative risk of injury increased with mean hourly wind speed and hourly maximum gust. Multivariable analysis, however, showed that relative risk of injury increased with maximum gust but not average wind speed, with relative risk of injury rising sharply above maximum gusts of greater than 20 m/s. Moderate wind speed with high gust (rather than high average and high gust) appears to be the most risky situation for injuries. Relative risk of injury was not associated with rainfall. The majority of injuries (56

  19. An autopsy study of death due to Suicidal Hanging – 264 cases

    Directory of Open Access Journals (Sweden)

    Dinesh Rao

    2016-09-01

    Full Text Available The present study was carried out between 2010 and 2013, a total of 7968 Autopsies were conducted of which 3.31% (n – 264 cases were deaths due to hanging. The most preferred ligature materials were Stole (n – 79 and Bed spread/Sari (n – 68. In 88% of the cases, hanging was complete. Females (n – 136 and males (n – 128 were equally affected. The major age group involved in both the sexes was of 31–40 years, contributing to 50.76% (n – 136 of the self suspension. In 80.58% (n – 213 of the incidents, ligature mark showed discontinuity (incomplete. A Slip type of knot was used in majority of the noose, contributing to 97.73% (n – 258 of the suspensions. In 87.88% (n – 232 of hanging an oblique shaped ligature mark was noticed. The horizontal and near oblique ligature marks were seen only in cases of partial suspension. In 95.45% (n – 252 of the cases, the ligature mark showed blackening of the skin (friction burn. Only 4.54% (n – 12 showed intact skin. The outer layer of the skin over the ligature mark showed displacement in majority of the cases. Married victims contributed to 70.45% of cases. Domestic issues were the commonest reason (n – 82 for self suspension, of which female (n – 68 formed the majority of victims. In 70.83% (n – 187 of cases damage to neck muscle fibers and hemorrhage at the Sternal end of the Sternocleidomastoid muscle were present. In 85.61% (n – 226 of cases the cervical vertebra was intact. In 52.27% (n – 138 of the cases the internal carotid artery showed transverse tear. In 99.42% (n – 248 cases the thyroid cartilage was found intact. The hyoid bone was damaged in 6.06% (n – 16 of the victims. Majority of the victims, 59.09% (n – 156 belonged to low socioeconomic class.

  20. Study of Dam-break Due to Overtopping of Four Small Dams in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Zakaraya Alhasan

    2015-01-01

    Full Text Available Dam-break due to overtopping is one of the most common types of embankment dam failures. During the floods in August 2002 in the Czech Republic, several small dams collapsed due to overtopping. In this paper, an analysis of the dam break process at the Luh, Velký Bělčický, Melín, and Metelský dams breached during the 2002 flood is presented. Comprehensive identification and analysis of the dam shape, properties of dam material and failure scenarios were carried out after the flood event to assemble data for the calibration of a numerical dam break model. A simple one-dimensional mathematical model was proposed for use in dam breach simulation, and a computer code was compiled. The model was calibrated using the field data mentioned above. Comparison of the erodibility parameters gained from the model showed reasonable agreement with the results of other authors.

  1. Theoretical study of properties due to the curvature in the toroid shape in magnetohydrodynamics; Etude theorique des proprietes dues a la courbure dans les configurations toriques en magnetohydrodynamique

    Energy Technology Data Exchange (ETDEWEB)

    Adam, J.C. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-03-01

    - We are considering a toroidal plasma centred around a closed {gamma}. When the rotational transform L/2{pi} approach an integer k if some specific relations are not satisfied curvature effects can become very important. When the rotational transform is created by current flowing in the plasma this happen if the coefficient a{sub k} of the Fourier expansion of curvature 1/R(s) of is non equal zero. One find then that the influence of a{sub k} is preponderant and that is possible to neglect all the other members of the series to study the neighbourhood of the corresponding equilibrium singularity. By developing an adapted coordinate system it is thus possible to take into account curvature effects at the lowest order. Equilibrium study bring us to introduce an equilibrium parameter {nu} {<=} 1 characterizing curvature effects. It is shown that the more {nu} is near of 1 the more shear and V{sup {phi}} quantities occurring in the stability criterion are important. Finally stability investigation show that the larger is the integer k the smaller is the domain of stability when L/2{pi} is near of k. (author) [French] Nous considerons un plasma toroidal centre autour d'une courbe fermee {gamma}. Lorsque la transformation rotationnelle L/2{pi} est voisine d'un nombre entier k, si certaines relations ne sont pas satisfaites, les effets de courbure peuvent devenir tres importants. Quand la transformation rotationnelle est cree par les courants circulant dans le plasma ceci se produit si le coefficient a{sub k} du developpement en serie de Fourier de la courbure 1/R(s) de {gamma} est non nul. On trouve alors que l'influence du k-ieme coefficient devient preponderante et il possible de negliger les autres termes pour etudier le voisinage de la singularite d'equilibre correspondante. En developpant un systeme de coordonnees adapte il est alors possible de tenir compte des le premier ordre des effets de courbure. L' etude de l'equilibre conduit a

  2. Clinical Study on Acupoint Injection plus Acupuncture for Insomnia Due to Heart-kidney Disharmony

    Institute of Scientific and Technical Information of China (English)

    Zheng Qiao-ping; Zhang Bi-meng; Zhou Jun-mei; Hu Qi-long

    2014-01-01

    Objective: To observe the clinical efficacy of acupoint injection at Neiguan (PC 6) plus acupuncture in treating insomnia due to heart-kidney disharmony. Methods: A hundred patients with insomnia due to heart-kidney disharmony were randomized into an observation group and a control group. Fifty-three cases in the observation group were intervened by acupoint injection at Neiguan (PC 6) plus acupuncture; while 54 cases in the control group were intervened by acupuncture alone. The Pittsburgh sleep quality index (PSQI) was evaluated before and after intervention, and the therapeutic efficacies of the two groups were compared. Results: Acupoint injection at Neiguan (PC 6) plus acupuncture produced significantly higher efficacies in improving sleep quality, shortening sleep latency, and enhancing sleep efficiency than acupuncture alone (P Conclusion: The two groups both can improve the condition of insomnia; acupoint injection at Neiguan (PC 6) has significant advantages, manifested by a higher therapeutic efficacy for insomnia due to heart-kidney disharmony, higher safety evaluation, efficiency, and less adverse events, thus proper for clinical application.

  3. Clinical features, diagnosis, treatment and molecular studies in paediatric Cushing's syndrome due to primary nodular adrenocortical hyperplasia

    DEFF Research Database (Denmark)

    Storr, Helen L; Mitchell, J H; Swords, F M

    2004-01-01

    BACKGROUND: Primary nodular adrenocortical hyperplasia (PNAH) is a well recognized, but infrequently studied cause of paediatric Cushing's syndrome (CS). OBJECTIVE: To assess presentation, diagnosis, radiological imaging, treatment and molecular analysis of patients with childhood-onset CS due...

  4. [Pseudo-tumoral human African trypanosomiasis due to Trypanosoma gambiense. Clinical and tomodensitometry study (author's transl)].

    Science.gov (United States)

    Poisson, M; Bleibel, J M; Regnier, A; Mashaly, R; Le Bigot, P; Danis, M; Buge, A

    The authors report an observation of african trypanosomiasis due to Trypanosoma Gambiense, clinical signs included massive and progressive hemiplegia, papillary edema and vascular shift from median line at arteriography. These pseudo tumoral clinical features are unusual in this disease. Asymetrical heterogenous hypodensities of the centrum semioval are dominant in the initial CT scanner aspect. The confrontation of CT scanner images to the clinical and evolutive data suggests the presence of associated cerebral edema and demyelination. With treatment, hypodensities were regressing while images of subcortical atrophy appeared. Lastly, in spite of severe general signs and the importance of neurological deficit, arsenical treatment associated with high doses of corticotherapy lead to a rapid improvement.

  5. CHF Phenomena by Photographic Study of Boiling Behavior due to Transient Heat Inputs

    OpenAIRE

    Jongdoc Park; Katsuya Fukuda; Qiusheng Liu

    2012-01-01

    The transient boiling heat transfer characteristics in a pool of water and highly wetting liquids such as ethanol and FC-72 due to an exponentially increasing heat input of various rates were investigated using the 1.0 mm diameter experimental heater shaped in a horizontal cylinder for wide ranges of pressure and subcooling. The trend of critical heat flux (CHF) values in relation to the periods was divided into three groups. The CHF belonging to the 1st group with a longer period occurs with...

  6. Costs of water treatment due to diminished water quality: A case study in Texas

    Science.gov (United States)

    Dearmont, David; McCarl, Bruce A.; Tolman, Deborah A.

    1998-04-01

    The cost of municipal water treatment due to diminished water quality represents an important component of the societal costs of water pollution. Here the chemical costs of municipal water treatment are expressed as a function of raw surface water quality. Data are used for a 3-year period for 12 water treatment plants in Texas. Results show that when regional raw water contamination is present, the chemical cost of water treatment is increased by 95 per million gallons (per 3785 m3) from a base of 75. A 1% increase in turbidity is shown to increase chemical costs by 0.25%.

  7. Numerical study on the effective heating due to inertial cavitation in microbubble-enhanced HIFU therapy

    Science.gov (United States)

    Okita, Kohei; Sugiyama, Kazuyasu; Takagi, Shu; Matsumoto, Yoichiro

    2015-10-01

    The enhancement of heating due to inertial cavitation was focused in high-intensity focused ultrasound (HIFU) therapy. The influences of the rectified diffusion on microbubble-enhanced HIFU were examined numerically. A bubble dynamics equation in consideration of the spherical shell bubble and the elasticity of surrounding tissue was employed. Mass and heat transfer between the surrounding medium and the bubble were considered. The basic equations were discretized by finite difference method. The mixture phase and bubbles are coupled by the Euler-Lagrange method to take into account the interaction between ultrasound and bubbles. The mass transfer rate of gas from the surrounding medium to the bubble was examined as function of the initial bubble radius and the driving pressure amplitude. As the results, the pressure required to bubble growth was decreases with increasing the initial bubble radius. Thus, the injection of microbubble reduces the cavitation threshold pressure. On the other hand, the influence of the rectified diffusion on the triggered HIFU therapy which generates cavitation bubbles by high-intensity burst and induces the localized heating owing to cavitation bubble oscillation by low-intensity continuous waves. The calculation showed that the localized heating was enhanced by the increase of the equilibrium bubble size due to the rectified diffusion.

  8. Polysynovitis in a horse due to Borrelia burgdorferi sensu lato infection – Case study

    Directory of Open Access Journals (Sweden)

    Fabrizio Passamonti

    2015-05-01

    Full Text Available Lyme borreliosis (LB is a multi-systemic tick-borne disease affecting both humans and animals, including horses, and is caused by a group of interrelated spirochetes classified within the Borrelia burgdorferi sensu lato (s.l. complex. Despite the high reported seroprevalence in the European equine population for B. burgdorferi s.l., to-date no documented clinical cases have been described. A 6-year-old Paint gelding was referred with a history of three weeks of fever, intermittent lameness and digital flexor tendon sheath effusion of the right hind limb. Based on a strict diagnostic protocol, which included serological tests for infectious diseases and molecular investigations, a final diagnosis was made of polysynovitis due to B. burgdorferi s.l. infection. An unreported aspect observed in this case was the absence of the pathogen DNA in two of the affected joints. To the authors’ knowledge, the case described represents the first documented clinical case of equine LB in Italy. Moreover, the absence of pathogen DNA in two of the affected joints observed in this case revealed a possible similarity with the same condition described in humans, where an immunomediated pathogenesis for arthropathy due to B. burgdorferi s.l. infection is suspected. Since humans and horses share the same habitat, this report supports the role of the horse as potential sentinel for human biological risk.

  9. Polysynovitis in a horse due to Borrelia burgdorferi sensu lato infection--Case study.

    Science.gov (United States)

    Passamonti, Fabrizio; Veronesi, Fabrizia; Cappelli, Katia; Capomaccio, Stefano; Reginato, Alice; Miglio, Arianna; Vardi, Doron M; Stefanetti, Valentina; Coletti, Mauro; Bazzica, Chiara; Pepe, Marco

    2015-01-01

    Lyme borreliosis (LB) is a multi-systemic tick-borne disease affecting both humans and animals, including horses, and is caused by a group of interrelated spirochetes classified within the Borrelia burgdorferi sensu lato (s.l.) complex. Despite the high reported seroprevalence in the European equine population for B. burgdorferi s.l., to-date no documented clinical cases have been described. A 6-year-old Paint gelding was referred with a history of three weeks of fever, intermittent lameness and digital flexor tendon sheath effusion of the right hind limb. Based on a strict diagnostic protocol, which included serological tests for infectious diseases and molecular investigations, a final diagnosis was made of polysynovitis due to B. burgdorferi s.l. infection. An unreported aspect observed in this case was the absence of the pathogen DNA in two of the affected joints. To the authors' knowledge, the case described represents the first documented clinical case of equine LB in Italy. Moreover, the absence of pathogen DNA in two of the affected joints observed in this case revealed a possible similarity with the same condition described in humans, where an immunomediated pathogenesis for arthropathy due to B. burgdorferi s.l. infection is suspected. Since humans and horses share the same habitat, this report supports the role of the horse as potential sentinel for human biological risk.

  10. Studies of crustal deformation due to hydrological loading on GPS height estimates

    Science.gov (United States)

    Rajner, Marcin; Liwosz, Tomasz

    2011-01-01

    The paper deals with large-scale crustal deformation due to hydrological surface loads and its influence on seasonal variation of GPS estimated heights. The research was concentrated on the area of Poland. The deformation caused by continental water storage has been computed on the basis of WaterGAP Hydrological Model data by applying convolution of water masses with appropriate Green's function. Obtained site displacements were compared with height changes estimated from GPS observations using the Precise Point Positioning (PPP) method. Long time series of the solutions for 4 stations were used for evaluation of surface loading phenomena. Good agreement both in amplitude and phase was found, however some discrepancies remain which are assigned to single point positioning technique deficiencies. Annual repeatability of water cycle and demanding procedure for computing site displacements for each site, allowed to develop a simple model for Poland which could be applied to remove (or highly reduce) seasonal hydrological signal from time series of GPS solutions.

  11. Experimental Study of Forces Exerted on Ships Due to the Vertical Walls of Navigation Channels

    Directory of Open Access Journals (Sweden)

    Mohammadreza Fathi Kazerooni

    2015-06-01

    Full Text Available Ship maneuvering in restricted waters of harbor basins and navigation channels had been the main concern in recent years due to sudden increase of ship’s size. When the ship enters a navigation channel the lateral boundary of the channel exerts a transverse force and turning moment on the ship hull. These forces are so important in the analysis of safety of ship navigation in the channels. Ship model test in the towing tank is a reliable method to evaluate these forces. Therefore systematic model tests are held for modeling of the forces exerted on the tanker ship and dhow model traveling alongside a vertical wall. A database of the interaction forces is developed and the specific hydrodynamic effects related to the phenomena are discussed. The results can be used for simulation of ship maneuvering and assessment of safety limits for navigation of ships alongside the quay walls and breakwaters.

  12. Sickness absence due to otoaudiological diagnoses and risk of disability pension: a nationwide Swedish prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Emilie Friberg

    Full Text Available BACKGROUND: Hearing difficulties are a large public health problem. Knowledge is scarce regarding risk of disability pension among people who have been sickness absent due to these difficulties. METHODS: A cohort including all 4,687,756 individuals living in Sweden in 2005, aged 20-64, and not on disability or old-age pension, was followed through 2009. Incidence rate ratios (RR of disability pension with 95% confidence intervals (CI were estimated using Cox proportional hazard models. RESULTS: In multivariable models, individuals who had a sick-leave spell due to otoaudiological diagnoses in 2005 had a 1.52-fold (95% CI: 1.43-1.62 increased risk of being granted a disability pension compared to individuals on sick leave due to other diagnoses. Hearing and tinnitus sick-leave diagnoses were associated with risk of disability pension: RR 3.38, 95% CI: 3.04-3.75, and 3.30, 95% CI: 2.95-3.68, respectively. No association was observed between sick leave due to vertigo diagnoses and disability pension whereas otological diagnoses and no sick leave were inversely associated with risk of disability pension compared to non-otoaudiological sick-leave diagnoses. Sick leave due to otoaudiological diagnoses was positively associated with risk of disability pension due to otoaudiological diagnoses and sick leave due to a tinnitus diagnosis was also associated with risk of disability pension due to mental diagnoses. The risk of disability pension among individuals with hearing or tinnitus sick-leave diagnoses was highest in the age group 35-44. Moreover, men had a slightly higher risk. CONCLUSION: This large cohort study suggests an increased risk of disability pension among those with sickness absence due to otoaudiological diagnoses, particularly hearing and tinnitus diagnoses, compared to those with sickness absence due to non-otoaudiological diagnoses.

  13. A modeling study of effective radiative forcing and climate response due to increased methane concentration

    Directory of Open Access Journals (Sweden)

    Bing Xie

    2016-12-01

    Full Text Available An atmospheric general circulation model BCC_AGCM2.0 and observation data from ARIS were used to calculate the effective radiative forcing (ERF due to increased methane concentration since pre-industrial times and its impacts on climate. The ERF of methane from 1750 to 2011 was 0.46 W m−2 by taking it as a well-mixed greenhouse gas, and the inhomogeneity of methane increased its ERF by about 0.02 W m−2. The change of methane concentration since pre-industrial led to an increase of 0.31 °C in global mean surface air temperature and 0.02 mm d−1 in global mean precipitation. The warming was prominent over the middle and high latitudes of the Northern Hemisphere (with a maximum increase exceeding 1.4 °C. The precipitation notably increased (maximum increase of 1.8 mm d−1 over the ocean between 10°N and 20°N and significantly decreased (maximum decrease >–0.6 mm d−1 between 10°S and 10°N. These changes caused a northward movement of precipitation cell in the Intertropical Convergence Zone (ITCZ. Cloud cover significantly increased (by approximately 4% in the high latitudes in both hemispheres, and sharply decreased (by approximately 3% in tropical areas.

  14. Adaptation to altered balance conditions in unilateral amputees due to atherosclerosis: a randomized controlled study

    Directory of Open Access Journals (Sweden)

    Bretz Éva

    2011-05-01

    Full Text Available Abstract Background Amputation impairs the ability to balance. We examined adaptation strategies in balance following dysvascularity-induced unilateral tibial amputation in skilled prosthetic users (SPU and first fitted amputees (FFA (N = 28. Methods Excursions of center of pressure (COP were determined during 20 s quiet standing using a stabilometry system with eyes-open on both legs or on the non-affected leg(s. Main measures: COP trajectories and time functions; distribution of reaction forces between the two legs; inclination angles obtained through second order regression analysis using stabilogram data. Results FFA vs SPU demonstrated 27.8% greater postural sway in bilateral stance (p = 0.0004. Postural sway area was smaller in FFA standing on the non-affected leg compared with SPU (p = 0.028. The slope of the regression line indicating postural stability was nearly identical in FFA and SPU and the direction of regression line was opposite for the left and right leg amputees. Conclusion Of the two adaptation strategies in balance, the first appears before amputation due to pain and fatigue in the affected leg. This strategy appears in the form of reduced postural sway while standing on the non-affected leg. The second adaptation occurs during rehabilitation and regular use of the prosthesis resulting in normal weightbearing associated with reduced postural sway on two legs and return to the normal postural stability on one leg.

  15. CHF Phenomena by Photographic Study of Boiling Behavior due to Transient Heat Inputs

    Directory of Open Access Journals (Sweden)

    Jongdoc Park

    2012-01-01

    Full Text Available The transient boiling heat transfer characteristics in a pool of water and highly wetting liquids such as ethanol and FC-72 due to an exponentially increasing heat input of various rates were investigated using the 1.0 mm diameter experimental heater shaped in a horizontal cylinder for wide ranges of pressure and subcooling. The trend of critical heat flux (CHF values in relation to the periods was divided into three groups. The CHF belonging to the 1st group with a longer period occurs with a fully developed nucleate boiling (FDNB heat transfer process. For the 2nd group with shorter periods, the direct transition to film boiling from non boiling occurs as an explosive boiling. The direct boiling transition at the CHF from non-boiling regime to film boiling occurred without a heat flux increase. It was confirmed that the initial boiling behavior is significantly affected by the property and the wettability of the liquid. The photographic observations on the vapor bubble behavior during transitions to film boiling were performed using a high-speed video camera system.

  16. Characteristics and Distribution of Mandibular Fractures Due to External Causes: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Dmitry José de Santana SARMENTO

    2007-05-01

    Full Text Available Purpose: To investigate the characteristics and distribution of the cases of mandibular fractures due to external causes treated at the Hospital Regional de Campina Grande, PB, Brazil, between January 2002 and December 2006. Method: For such purpose, an indirect review of 691 medical-hospital patient files of the Service of Oral and Maxillofacial Surgery were reviewed. A total of 59 (8.5% files referred to mandibular fracture victims. The following variables were analyzed: gender, age range, time of occurrence (date and hour, etiology, presence of associated fractures, type of treatment and time of hospitalization. Results: The results showed that males were more frequently affected than females (83.1%, with predominance in the 21-30 age range (40.7%. Most cases were treated on Saturdays and Sundays (40.6% and at night (30.5%. Falls, (28.8%, interpersonal violence (23.7% and motorcycle accidents (23.7% were the main etiologies. Five patients (8.5% presented fractures in other facial bones and the most frequent treatment was the intermaxillary retention with stainless steel wire (50.8%. The mean hospitalization time was 5.28 days.Conclusions: The prevalence of mandibular fractures is higher in the male gender, during the third decade of life; falls were the main etiologic factor and most cases occurred during the weekend.

  17. Analysis of Environmental Costs of Mobility due to Urban Sprawl - A Modelling Study on Italian Cities

    NARCIS (Netherlands)

    Travisi, Chiara M.; Camagni, Roberto; Nijkamp, Peter

    2006-01-01

    A sound empirical and quantitative analysis on the relationship between different patterns of urban expansion and the environmental or social costs of mobility is rare, and the few studies available provide at best a qualitative discussion of these issues. Some recent tentative studies on the

  18. The Clinical Study on 34 Admission Patients due to Sequela of Traffic Accident

    OpenAIRE

    No, Bu-Rae; Lee, Eun-Yong

    2006-01-01

    Objectives : The purpose of this study was to investigate the clinical progress of patients diagnosed as sequela of traffic accident. Methods : We studied 34 cases who were admitted in Semyung University Oriental Hospital from 1st, January, 2005 to the 31st, December, 2005. And we came to some conclusion about clinical tendencies as follows. Results and Conclusions : 1. Women had occupied more than men, and 14 persons in 20th were the most distribution of age. 2. In distribution o...

  19. Gender and age differences in the recurrence of sickness absence due to common mental disorders: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Bültmann Ute

    2010-07-01

    Full Text Available Abstract Background Common mental disorders (CMDs are an important cause of sickness absence and long-term work disability. Although CMDs are known to have high recurrence rates, little is known about the recurrence of sickness absence due to CMDs. The aim of this study was to investigate the recurrence of sickness absence due to CMDs, including distress, adjustment disorders, depressive disorders and anxiety disorders, according to age, in male and female employees in the Netherlands. Methods Data on sickness absence episodes due to CMDs were obtained for 137,172 employees working in the Dutch Post and Telecommunication companies between 2001 and 2007. The incidence density (ID and recurrence density (RD of sickness absence due to CMDs was calculated per 1000 person-years in men and women in the age-groups of Results The ID of one episode of CMDs sickness absence was 25.0 per 1000 person-years, and the RD was 76.7 per 1000 person-years. Sickness absence due to psychiatric disorders (anxiety and depression does not have a higher recurrence density of sickness absence due to any CMDs as compared to stress-related disorders (distress and adjustment disorders: 81.6 versus 76.0 per 1000 person-years. The ID of sickness absence due to CMDs was higher in women than in men, but the RD was similar. Recurrences were more frequent in women Conclusions Employees who have been absent from work due to CMDs are at increased risk of recurrent sickness absence due to CMDs and should be monitored after they return to work. The RD was similar in men and in women. In women

  20. Study of Hydrodynamics due to Turbulent Mixing in Animal Cell Microcarrier Bioreactors

    Science.gov (United States)

    Venkat, Raghavan V.

    1995-01-01

    Turbulent mixing is essential for improving oxygenation and to provide uniform nutrients to microcarrier animal cell cultures grown in agitated stirred reactors. Large -scale microcarrier culture is plagued with problems of scale-up. Hydrodynamics due to impeller agitation was found to be one of the major causes for cell damage in microcarrier culture. Insufficient or improper scale-up of agitation environment from small-scale to large-scale has been postulated to be one of the main causes for failure of large-scale microcarrier culture. For successful scale-up of microcarrier culture, it will be useful to obtain the flow characteristics in typical reactors: macro-characteristics that provides information on zoning/unmixed regions within the reactor as well as fundamental flow information such as velocity fields and energy distribution in the impeller stream of the reactors. This information can lead to methods of scale-up that preserve flow environments in different sizes of bioreactors. Three dimensional particle tracking velocimetry (3-D PTV) was used to map the flow fields in the impeller stream of the spinner vessel, 3 L bench-scale, 20 L medium -scale, and 150 L large-scale cell culture reactors. For the purposes of characterization of the 150 L large-scale reactor, an internal dual lens probe system was designed to visualize the turbulent mixing environment. 3-D (stereo) visual information obtained was used to come up with mean velocity fields and energy distribution in the impeller stream of the reactors. Fundamental flow information obtained was further used to arrive at the flow structures/patterns that exist in the impeller stream and the distribution of energy parameters: viscous dissipation rate, mean turbulent kinetic energy and the pseudo-shear rate, within the flow structures. The impeller stream of all the reactors was found to be highly anisotropic and dominated by distinct flow structures. The highest values of the energy parameters were also

  1. Radiation exposure and dosimetry in transplant patients due to Nuclear Medicine studies

    Energy Technology Data Exchange (ETDEWEB)

    El-Maghraby, T. A. F. [Leiden Univ., Leiden (Netherlands). Dept. of Radiology, Div. of Nuclear Medicine; Cairo Univ., Cairo (Egypt). Faculty of Medicine, Dept. of Oncology and Nuclear Medicine; Camps, J. A. J.; Geleyns, J.; Pauwels, E. K. J. [Leiden Univ., Leiden (Netherlands). Dept. of Radiology, Div. of Nuclear Medicine

    2000-12-01

    Organ transplantation is now an accepted method of therapy for treating patients with end stage failure of kidneys, liver, heart or lung. Nuclear Medicine may provide functional data and semi-quantitative parameters. However, one serious factor that hampers the use of nuclear medicine procedures in transplant patients is the general clinical concern about radiation exposure to the patient. This lead the researcher to discuss the effective doses and radiation dosimetry associated with radionuclide procedures used in the management and follow-up of transplant patients. A simple way to place the risk associated with Nuclear Medicine studies in an appropriate context is to compare the dose with that received from more familiar source of exposure such as from a diagnostic X-ray procedure. The radiation dose for the different radiopharmaceuticals used to study transplant organ function ranges between 0.1 and 5.3 mSv which is comparable to X-ray procedures with the exception of {sup 201}Tl and {sup 111}In-antimyosin. Thus Nuclear Medicine studies do not bear a higher radiation risk than the often used X-ray studies in transplant patients.

  2. Allergic contact dermatitis due to cosmetics: A clinical and epidemiological study in a tertiary hospital.

    Science.gov (United States)

    Zaragoza-Ninet, V; Blasco Encinas, R; Vilata-Corell, J J; Pérez-Ferriols, A; Sierra-Talamantes, C; Esteve-Martínez, A; de la Cuadra-Oyanguren, J

    2016-05-01

    The incidence of allergic contact dermatitis (ACD) to cosmetics in the general population is rising with the increasing use of cosmetic products and their proliferation and diversification. The aims of this study were to determine the prevalence of ACD to cosmetics in our setting, analyze changes over time, describe the clinical and epidemiological features of this allergic reaction, and identify the allergens and cosmetics involved. We performed a prospective study at the skin allergy unit in Hospital General Universitario de Valencia in Spain between 2005 and 2013 and compared our findings with data collected retrospectively for the period 1996 to 2004. The 5419 patients who underwent patch testing during these 2 periods were included in the study. The mean prevalence of ACD to cosmetics increased from 9.8% in the first period (1996-2004) to 13.9% in the second period (2005-2013). A significant correlation was found between ACD to cosmetics and female sex but not atopy. Kathon CG (blend of methylchloroisothiazolinone and methylisothiazolinone), fragrances, and paraphenylenediamine were the most common causes of ACD to cosmetics during both study periods, and acrylates and sunscreens were identified as emerging allergens during the second period. Copyright © 2016 AEDV. Published by Elsevier España, S.L.U. All rights reserved.

  3. Risk of upper limb complaints due to computer use in older persons: a randomized study

    Directory of Open Access Journals (Sweden)

    Jolles Jelle

    2007-08-01

    Full Text Available Abstract Background We studied whether the twelve-month use of a standard computer would induce complaints of upper limb pain or functional limitations in older novice computer users. Methods Participants between 64 and 76 of age were randomly assigned to an Intervention group (n = 62, whose members received a personal computer and fast Internet access at their homes, or a No Intervention control group (n = 61, whose members refrained from computer use during the twelve month study period. Results Difference scores between baseline and twelve months assessments on both complaint (SFS and functional health scales (SF-36 did not differ between groups (all p > .05. Conclusion Prolonged, self-paced use of a standard computer interface does not put older persons at a risk of upper limb complaints or reduce functional health in older adults.

  4. Venous thromboembolism and subsequent hospitalisation due to acute arterial cardiovascular events: a 20-year cohort study

    DEFF Research Database (Denmark)

    Sørensen, Henrik Toft; Horvath-Puho, Erzsebet; Pedersen, Lars

    2007-01-01

    of myocardial infarction and stroke in 25,199 patients with deep venous thrombosis, 16,925 patients with pulmonary embolism, and 163,566 population controls. FINDINGS: For patients with deep venous thrombosis, the relative risks varied from 1.60 for myocardial infarction (95% CI 1.35-1.91) to 2.19 (1......-up, with 20-40% increases in risk for arterial cardiovascular events. Relative risks were similar for those with provoked and unprovoked deep venous thrombosis and pulmonary embolism. INTERPRETATION: Patients with venous thromboembolism have a substantially increased long-term risk of subsequent arterial......BACKGROUND: In some studies, venous thromboembolism has been associated with atherosclerosis and with the risk of arterial cardiovascular events such as myocardial infarction and stroke. Other studies, however, do not show this association. To help clarify these discrepant findings, we aimed...

  5. Qualitative simulation of bathymetric changes due to reservoir sedimentation: A Japanese case study.

    Science.gov (United States)

    Bilal, Ahmed; Dai, Wenhong; Larson, Magnus; Beebo, Qaid Naamo; Xie, Qiancheng

    2017-01-01

    Sediment-dynamics modeling is a useful tool for estimating a dam's lifespan and its cost-benefit analysis. Collecting real data for sediment-dynamics analysis from conventional field survey methods is both tedious and expensive. Therefore, for most rivers, the historical record of data is either missing or not very detailed. Available data and existing tools have much potential and may be used for qualitative prediction of future bathymetric change trend. This study shows that proxy approaches may be used to increase the spatiotemporal resolution of flow data, and hypothesize the river cross-sections and sediment data. Sediment-dynamics analysis of the reach of the Tenryu River upstream of Sakuma Dam in Japan was performed to predict its future bathymetric changes using a 1D numerical model (HEC-RAS). In this case study, only annually-averaged flow data and the river's longitudinal bed profile at 5-year intervals were available. Therefore, the other required data, including river cross-section and geometry and sediment inflow grain sizes, had to be hypothesized or assimilated indirectly. The model yielded a good qualitative agreement, with an R2 (coefficient of determination) of 0.8 for the observed and simulated bed profiles. A predictive simulation demonstrated that the useful life of the dam would end after the year 2035 (±5 years), which is in conformity with initial detailed estimates. The study indicates that a sediment-dynamic analysis can be performed even with a limited amount of data. However, such studies may only assess the qualitative trends of sediment dynamics.

  6. A Study of Plazomicin Compared With Colistin in Patients With Infection Due to Carbapenem-Resistant Enterobacteriaceae (CRE)

    Science.gov (United States)

    2016-10-03

    Bloodstream Infections (BSI) Due to CRE; Hospital-Acquired Bacterial Pneumonia (HABP) Due to CRE; Ventilator-Associated Bacterial Pneumonia (VABP) Due to CRE; Complicated Urinary Tract Infection (cUTI) Due to CRE; Acute Pyelonephritis (AP) Due to CRE

  7. Study the air pollution due to Dorud Cement Plant (in Iran

    Directory of Open Access Journals (Sweden)

    Vahid Mokhtari

    2016-09-01

    Full Text Available Cement industry is one of the most important industries in the country. Dorud Cement Plant is one of the largest and oldest Iran's cement factories, which is working in the center of the city of Dorud. In this study, aimed to investigate air pollution resulting from Dorud cement plant, the parameters of CO, CO2, O2, NO, NO2, NOx, SO2, dry dust particles, particles weight and environmental particulates of PM10 and PM2.5 were measured with conventional methods of measuring emissions from industrial chimneys and by using automatic measuring equipment, and the rates of emissions from the chimneys of the plant were calculated during a working year. These measurements were made over three months, from February 20, 2015 to May 21, 2015, at 3 stations of Link1-k1, Link2-k1 and Link3-k1, which are the chimneys of the three-lines of the plant. It was found in this study that the chimney No. 3 enters the maximum contaminant into the environment. The results also showed that based on the standards defined for the cement industry, Dorud cement plant meets the relative optimal conditions in terms of comparing performance with the standards, and the emissions from the factory are less than the enacted standards for this industry. Also, the preventive measures and equipment for reducing emissions established in this industrial unit have a relative utility. In this study, the factors including type of raw materials used, old production lines and old factory equipment, type of producing cement and proximity to the city were determined as main reasons for the emissions produced by this industry. Also, some management solutions such as the use of environment designing inside the manufacturing process of the plant and outside the plant, using flame-reducing, construction of a new phase and relocating the plant were suggested to reduce emissions from Dorud cement plants.

  8. Predictive study on the risk of malaria spreading due to global warming

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Masaji [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan)

    1996-12-31

    Global warming will bring about a temperature elevation, and the habitat of vectors of infectious diseases, such as malaria and dengue fever, will spread into subtropical or temperate zone. The purpose of this study is to simulate the spreading of these diseases through reexamination of existing data and collection of some additional information by field survey. From these data, the author will establish the relationship between meteorological conditions, vector density and malaria occurrence. And then he will simulate and predict the malaria epidemics in case of temperature elevation in southeast Asia and Japan.

  9. A Study of Spectral Electroretinogram of Color Vision Defects Due to Macular Diseases

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Studies of spectral electroretinograms in central serous retinopa-thy (CSR) and hereditary macular degeneration (HMD) showed that the b-wave amplitudes of most wavelengths of CSR were significantly decreased as compared with normal controls, and those of HMD were obviously lower than the normal values. Patients of HMD with type-A color vision defects (CVD) had primarily a reduction of b-wave amplitudes in the full spectrum of 480-620 nm, and patients with type- I CVD a reduction of b-wave amplitudes wav...

  10. The Study of Wound Infection Rate Due to Midsternatomy after Heart Surgeries

    Directory of Open Access Journals (Sweden)

    R. Safiarian

    2011-01-01

    Full Text Available Introduction & Objective: Sternal wound infection and dehiscence are feared complications observed in 0.4-5% of cardiac operations. Even nowadays the mortality remains as high as 20-40%. The aim of the current study was to determine the rate of sternal wound infection. Material and Methods: The outcomes of 388 patients undergoing cardiac surgery during a 7 month follow up were analyzed and their risk factors such as obesity, diabetes, cigarette smoking, blood transfusion, renal failure, hypertension, COPD, preoperative ejection fraction, aortic clamping time, and time of cardio pulmonary bypass were evaluated. The data was analyzed by t-test & 2 statistical tests. Results: The present study revealed that 3 patients developed wound infection and dehiscence and its incidence was 0.74% (P=0.042. There was not any significant relationship between wound infection and the other risk factors (P>0.05. Conclusions: Our results indicate that ejection fraction preoperatively is very important in sternal wound infection. (Sci J Hamadan Univ Med Sci 2011;17(4:39-42

  11. Tooth displacement due to occlusal contacts: a three-dimensional finite element study.

    Science.gov (United States)

    Gomes de Oliveira, S; Seraidarian, P I; Landre, J; Oliveira, D D; Cavalcanti, B N

    2006-12-01

    The use of the Finite Element Method (FE) is an appropriate way to study occlusal forces and tooth movement. The purpose of this study was to evaluate the effects of different occlusal contact patterns on tooth displacement in an adult dentition using a three-dimensional FE model of a human maxilla and mandible. Initially, images of a computerized tomography scan were redrawn in a computer program (CATIA) followed by the FE mesh construction. The MSC/Patran software was used to develop the FE mesh comprising 520,445 elements and 106,633 nodes. The MSC/Nastran program was utilized as pre and post-processor for all mathematical calculations necessary to evaluate dental and mandibular biomechanics. Four occlusal patterns were tested: FEM 1 - standard occlusal contacts; FEM 2 - removal of mesial marginal and mesial tripoidism contacts; FEM 3 - removal of distal marginal and distal tripoidism contacts; FEM 4 - similar to FEM 3 with added contacts between upper and lower incisors. Small changes in the standard distribution of occlusal contacts resulted in an imbalance of occlusal forces and changes in dental positioning. All simulations tested showed mesial displacement of posterior teeth. The most significant changes were registered in the model presenting unstable occlusal contacts when the anterior teeth were in occlusion (FEM 4). These findings may explain mandibular incisors crowding and maxillary incisors flaring as a result of small variations in dental contacts.

  12. Clinicopathological study of cardiac tamponade due to pericardial metastasis originating from gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Michiya Kobayashi; Takehiro Okabayashi; Ken Okamoto; Tsutomu Namikawa; Keijiro Araki

    2005-01-01

    AIM: To review the cases reported in the literature,examined their clinicopathological features, and evaluated the efficacy of different therapeutic modalities for this rare condition.METHODS: A search of the MEDLINE database revealed 16 cases of pericarditis carcinomatosa (PC)originating from GC reported in the literature between1982 and 2005. Additional detailed data were obtained from the authors of these studies for subsequent clinicopathological investigation. We have also described about a case study from our own clinic.RESULTS: The mean age of cases with pericarditis carcinomatosa originating from GC was 54 years.Females were diagnosed at a younger age (46.3 years)compared to males (58 years). The mean survival period after diagnosis was 4.5 mo. No statistical differences in the length of survival time were found between different therapeutic modalities, such as drainage, and local and/or systemic chemotherapy after drainage. However,three cases who underwent systemic chemotherapy survived for more than 10 mo. Cases that developed metachronous cardiac tamponade for more than 2years after the diagnosis of GC generally survived for a longer period of time, although this was not statistically significant. Multivariate analysis revealed that low levels of carcinoembryonic antigen (CEA), and CEA and/or cancer antigen 19-9 (CA 19-9) were associated with longer survival.CONCLUSION: Cases with low levels of CEA, and CEA and/or CA 19-9 should undergo systemic chemotherapy with or without local chemotherapy after drainage.

  13. Prospective evaluation of indirect costs due to acute rotavirus gastroenteritis in Spain: the ROTACOST study.

    Science.gov (United States)

    Bouzón-Alejandro, Marta; Redondo-Collazo, Lorenzo; Sánchez-Lastres, Juan Manuel; Martinón-Torres, Nazareth; Martinón-Sánchez, José María; Martinón-Torres, Federico

    2011-09-14

    The effect of rotavirus in developed countries is mainly economic. This study aimed to assess the indirect costs induced by rotavirus acute gastroenteritis (RVAGE) in Spain. A prospective observational study was conducted from October 2008 to June 2009. It included 682 children up to 5 years of age with acute gastroenteritis (AGE) who attended primary care (n = 18) and emergency room/hospital settings (n = 10), covering the regions of Galicia and Asturias (North-west Spain). All non-medical expenses incurred throughout the episode were recorded in detail using personal interviews and telephone contact. Among the 682 enrolled children, 207 (30.4%) were rotavirus positive and 170 (25%) had received at least one dose of rotavirus vaccine. The mean (standard deviation) indirect cost caused by an episode of AGE was estimated at 135.17 (182.70) Euros. Costs were 1.74-fold higher when AGE was caused by rotavirus compared with other etiologies: 192.7 (219.8) Euros vs. 111.6 (163.5) Euros (p purchase of material. Patients with RVAGE were admitted to hospital more frequently than those with other etiologies (47.8% vs 14%, p decision-making process of the eventual inclusion of rotavirus vaccine in the national immunization schedule of well developed countries.

  14. Finite element analysis of vessels to study changes in natural frequencies due to cracks

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, A. [ITMME Centre, Indian Institute of Technology, Hauz Khas, New Delhi 110 016 (India); Sehgal, D.K. [ITMME Centre, Indian Institute of Technology, Hauz Khas, New Delhi 110 016 (India); Tandon, N. [ITMME Centre, Indian Institute of Technology, Hauz Khas, New Delhi 110 016 (India)]. E-mail: ntandon@itmmec.iitd.ernet.in

    2006-03-15

    When significant damage occurs in structures, there is a change in stiffness, which in turn affects the natural frequency. To study this, a study was conducted to analyse the effect of cracks on natural frequencies in two vessel structures. Finite element analysis has been used to obtain the dynamic characteristics of intact and damaged vessels for the first eight modes of these structures. Two kinds of vessel, boilers and storage tanks, were chosen and through-thickness cracks were analysed. Different cases were examined by changing the size and locations of cracks with the help of a FEM (Finite element model). Natural frequencies and mode shapes were analysed. The natural frequencies for different modes have been used as input pattern of ANN (artificial neural network) model. The output of the ANN model is a crack size for a particular location. It was found that as the crack size increased, natural frequency changed to a large extent, but the frequency was not reduced in the same manner for every position of damage for the same size of crack. It was also found that the reduction in natural frequencies depends upon the mode shapes of the structures.

  15. Secondary bilateral synchrony due to fronto-mesial lesions: an invasive recording study

    Directory of Open Access Journals (Sweden)

    CUKIERT ARTHUR

    1999-01-01

    Full Text Available Frontal lobe epilepsies may present difficulties in focus localization in the pre-operative work-up for epilepsy surgery. This is specially true in patients with normal MRIs. We report on a 16 years-old girl that started with seizures by the age of 8 years. They were brief nocturnal episodes with automatisms such as bicycling and boxing. Seizure frequency ranged from 4-10 per night. Scalp EEG showed few right frontal convexity spiking and intense secondary bilateral syncrhony (SBS. High resolution MRI directed to the frontal lobes was normal. Ictal SPECT suggested a right fronto-lateral focus. Ictal video-EEG showed no focal onset. She was submitted to invasive recordings after subdural plates implantation. Electrodes covered all the frontal convexity and mesial surface bilaterally. Ictal recordings disclosed stereotyped seizures starting from the right mesial frontal. Using a high-resolution tool to measure intra and interhemispheric latencies, the timing and direction of seizure spread from the right fronto-mesial region were studied. Motor strip mapping was performed by means of electrical stimulation. She was submitted to a right frontal lobe resection, 1.5 cm ahead of the motor strip and has been seizure free since surgery (8 months. Pathological examination found a 4 mm area of cortical dysplasia. Invasive studies are needed to allow adequate localization in patients with non-localizatory non-invasive work-up and may lead to excellent results in relation to seizures after surgery.

  16. Loss of relaxor properties due to dipolar interactions in ferroelectrics: A 2D Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Zaldivar, O.; Calderon-Pinar, F.; Pelaiz-Barranco, A. [Physics Faculty - Materials Science and Technology Institute (IMRE), Havana University, La Habana, CP 10400 (Cuba); Diaz-Mendez, R. [Nanophysics Group, Department of Physics, Electric Engineering Faculty, CUJAE, La Habana (Cuba); Group of Complex Systems, Physics Faculty, Havana University, La Habana, CP 10400 (Cuba)

    2012-11-15

    The behavior of the dielectric response in relaxor ferroelectric materials is studied by means of Monte Carlo simulations of a simple two-dimensional (2D) generic model. It is showed that the shifting with the frequency of the peak of the temperature dependence of the dielectric permittivity {epsilon} can be obtained just by considering a randomly distributed pinning anisotropy for the out-plane projection of the polar nanoregions. It is also showed that the consideration of a weak long-range dipolar interaction between nanodomains continuously drives the system to a non-relaxor ferroelectric state in which a single peak is observed for the dielectric permittivity. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Experimental studies of the streaming flow due to the adsorption of particles at a liquid surface

    Science.gov (United States)

    Singh, Pushpendra; Musunuri, Naga; Fischer, Ian

    2016-11-01

    The particle image velocimetry (PIV) technique is used to study the streaming flow that is induced when particles are adsorbed at a liquid surface. The flow develops within a fraction of second after the adsorption of the particle and persists for several seconds. The fluid directly below the particle rises upward, and near the surface, it moves away from the particle. The flow causes powders sprinkled on a liquid surface to disperse on the surface. The flow strength, and the volume over which it extends, decreases with decreasing particle size. The streaming flow induced by the adsorption of two or more particles is a combination of the flows which they induce individually. The work was supported by National Science Foundation.

  18. Modification of optoelectronic properties of conjugated oligomers due to donor/acceptor functionalization: DFT study

    Science.gov (United States)

    Zhugayevych, Andriy; Postupna, Olena; Wang, Hsing-Lin; Tretiak, Sergei

    2016-12-01

    A comprehensive DFT study of a set of oligo(p-phenylene vinylene) molecules is performed to understand the structural and electronic changes upon functionalization. These changes are rationalized within a model considering frontier molecular orbitals of the π -conjugated system and σ -bonding orbital by which the functional group is attached to the host molecule. Two simple scalar quantum chemical descriptors are shown to correlate with optoelectronic properties of the functionalized molecule: the electronegativity and the relative electric dipole moment of the smallest π -closed shell subsystem containing the functional group and the terminal segment of the host molecule (phenyl). Both descriptors correlate linearly with the empirical Hammett σp constant for a set of 24 functional groups. Comparison with available experimental data on UV-vis absorption and cyclic voltammetry is made. Observed structural changes reflect changes in the electronic density.

  19. Physical geography and the study of human vulnerability due to natural and other hazards

    Directory of Open Access Journals (Sweden)

    Karel Natek

    2003-12-01

    Full Text Available Physical geography in Slovenia has achieved a significant level of knowledge on natural and other hazards, after studying these phenomena since 1950s. These extremely complex features are clearly showing the interconnections between the nature and man and the increasing vulnerability of modern societies. The article is based on geographical approach to hazards, which does not consider them as casual events, but as constituent parts of the environment, including very different ways of human adaptation. The rapid development of science and technology have even increased our vulnerability and direct exposure to hazards, what is considered as new challenge to physical geographers in looking for new approaches to increase the possibilities of sustainable 'co-existence' with natural and other hazards.

  20. Less-studied TCE: are their environmental concentrations increasing due to their use in new technologies?

    Science.gov (United States)

    Filella, M; Rodríguez-Murillo, J C

    2017-09-01

    The possible environmental impact of the recent increase in use of a group of technology-critical elements (Nb, Ta, Ga, In, Ge and Te) is analysed by reviewing published concentration profiles in environmental archives (ice cores, ombrotrophic peat bogs, freshwater sediments and moss surveys) and evaluating temporal trends in surface waters. No increase has so far been recorded. The low potential direct emissions of these elements, resulting from their absolute low production levels, make it unlikely that the increasing use of these elements in modern technology has any noticeable effect on their environmental concentrations on a global scale. This holds particularly true for those of these elements that are probably emitted in relatively high amounts from other human activities (i.e., coal combustion and non-ferrous smelting), such as In, the most studied element of the group. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The Study on the Durability of Submerged Structure Displacement due to Concrete Failure

    Science.gov (United States)

    Mohd, M.; Zainon, O.; Rasib, A. W.; Majid, Z.

    2016-09-01

    Concrete structures that exposed to marine environments are subjected to multiple deterioration mechanisms. An overview of the existing technology for submerged concrete, pressure resistant, concrete structures which related such as cracks, debonds, and delamination are discussed. Basic knowledge related to drowning durability such as submerged concrete structures in the maritime environment are the durability of a concrete and the ability to resist to weathering, chemical attack, abrasion or other deterioration processes. The measuring techniques and instrumentation for geometrical monitoring of submerged structural displacements have traditionally been categorized into two groups according to the two main groups, namely as geodetic surveying and geotechnical structural measurements of local displacements. This paper aims to study the durability of submerged concrete displacement and harmful effects of submerged concrete structures.

  2. Integrating murine gene expression studies to understand obstructive lung disease due to chronic inhaled endotoxin.

    Directory of Open Access Journals (Sweden)

    Peggy S Lai

    Full Text Available RATIONALE: Endotoxin is a near ubiquitous environmental exposure that that has been associated with both asthma and chronic obstructive pulmonary disease (COPD. These obstructive lung diseases have a complex pathophysiology, making them difficult to study comprehensively in the context of endotoxin. Genome-wide gene expression studies have been used to identify a molecular snapshot of the response to environmental exposures. Identification of differentially expressed genes shared across all published murine models of chronic inhaled endotoxin will provide insight into the biology underlying endotoxin-associated lung disease. METHODS: We identified three published murine models with gene expression profiling after repeated low-dose inhaled endotoxin. All array data from these experiments were re-analyzed, annotated consistently, and tested for shared genes found to be differentially expressed. Additional functional comparison was conducted by testing for significant enrichment of differentially expressed genes in known pathways. The importance of this gene signature in smoking-related lung disease was assessed using hierarchical clustering in an independent experiment where mice were exposed to endotoxin, smoke, and endotoxin plus smoke. RESULTS: A 101-gene signature was detected in three murine models, more than expected by chance. The three model systems exhibit additional similarity beyond shared genes when compared at the pathway level, with increasing enrichment of inflammatory pathways associated with longer duration of endotoxin exposure. Genes and pathways important in both asthma and COPD were shared across all endotoxin models. Mice exposed to endotoxin, smoke, and smoke plus endotoxin were accurately classified with the endotoxin gene signature. CONCLUSIONS: Despite the differences in laboratory, duration of exposure, and strain of mouse used in three experimental models of chronic inhaled endotoxin, surprising similarities in gene

  3. The Clinical Study on 34 Admission Patients due to Sequela of Traffic Accident

    Directory of Open Access Journals (Sweden)

    No, Bu-Rae

    2006-06-01

    Full Text Available Objectives : The purpose of this study was to investigate the clinical progress of patients diagnosed as sequela of traffic accident. Methods : We studied 34 cases who were admitted in Semyung University Oriental Hospital from 1st, January, 2005 to the 31st, December, 2005. And we came to some conclusion about clinical tendencies as follows. Results and Conclusions : 1. Women had occupied more than men, and 14 persons in 20th were the most distribution of age. 2. In distribution of onset, less than 7 days was the most(58.8 %, followed by less then 28 days(20.6 %. 3. Most patients used western medical hospital(47.1 % and oriental medical hospital(44.1 % as primary hospital. 4. In chief complaint, cervical pain was most(32 cases, 94.1%, the others were low back pain(22 cases, 64.7 %, back pain(5 cases, 14.7 %, chest pain(5 cases, 14.7 %. 5. In treatment methods, acupuncture and physical therapy was most(33 cases, 97.1%, the others were Extract-med.(31 cases, 94.0%, electric-acupuncture(27 cases, 79.4%, Herb-med.(23 cases, 67.6%, Herb-acupuncture(l8 cases, 52.9% and Taping therapy(15 cases, 44.1%. 6. In hospital days, days was most(l5 cases, 44.1%, the other were 15-21days(l2 cases, 35.3%. over the 29 days(4 cases, 11.8% and 22-28 days(3 cases, 8.8%. 7. 34 patients were examined, and all cases were 'improved'. And statistically significance compared after-treatment with before-treatment group(p<0.005.

  4. Prospective Study to Assess Progression of Renal Markers after Interruption of Tenofovir due to Nephrotoxicity

    Directory of Open Access Journals (Sweden)

    Anna Bonjoch

    2016-01-01

    Full Text Available Background. Prospective studies about the reversibility of tenofovir disoproxil fumarate- (TDF- related renal impairment remain scarce. Methods. This is an observational prospective study including all patients that presented at our HIV Unit who interrupted TDF owing to nephrotoxicity. We assessed the evolution of renal parameters after discontinuation of this drug. Results. We included 59 patients, who were followed up for 72 weeks. Most were male (41, 69.5%, median (IQR age was 53 (44; 58 years, and median time receiving TDF-containing regimens was 55.4 (28; 87.7 months. Most patients were receiving PI-based treatments (67%. At the final visit, most of the subjects showed complete recovery (35, 59.3% or improvement (13 subjects, 22%. Significant improvements were observed in creatinine levels (from 84.9 [73.8; 97.5] to 78 [69.6; 91] μmol/L, p=0.013, estimated glomerular filtration rate (eGFR, CKD EPI equation, from 87.7 [67; 99] to 89.9 [73.6; 99.3] mL/min/1.73 m2, p=0.017, and number of patients with eGFR <60 mL/min/1.73 m2 (from 9 [15.3%] to 1 [1.7%], p=0.031. A trend toward significance was observed in abnormal urine proteinuria/creatinine ratio (from 22 [37%] to 8 [13.6%], p=0.057. Conclusions. Our results corroborate the high frequency of complete or partial renal recovery in patients receiving TDF-containing regimens who discontinued therapy owing to nephrotoxicity.

  5. Quantitative study of myocardial microcirculation in arterial hypertension due to progressive inhibition of NO synthesis

    Directory of Open Access Journals (Sweden)

    Leila Maria Meirelles Pereira

    1999-11-01

    Full Text Available OBJECTIVE: To study the quantitative changes in intramyocardial blood vessels in rats in whom nitric oxide synthesis was inhibited. METHODS: Four groups of 10 rats were studied: control (C25 and C40 and L-NAME (L25 and L40. The animals L25 and L40 received L-NAME in the dosage of 50mg/kg/day for 25 and 40 days, respectively. On days 26 and 41 the animals in groups 25 and 40 were sacrificed. Analysis of the myocardium was performed using light microscopy and stereology. RESULTS: Arterial blood pressure and heart weight increased 74.5 and 57.8% after 25 days and 90.2 and 34.6% after 40 days, respectively. Comparing the L-NAME rats with the respective controls revealed that vessel volume density decreased 31.3% after 40 days, and the vessel length-density decreased 53.5% after 25 days and 25.7% after 40 days. The mean cross-sectional area of the vessels showed an important reduction of 154.6% after 25 days. The intramyocardial vessels decreased significantly in length- density in the L-NAME animals. The mean cross-sectional area of the vessels, which normally increases during heart growth between 25 and 40 days, showed a precocious increase by the 25th day in the L-NAME rats. This suggests an increase of the size of the heart, including blood vessels. CONCLUSION: The inhibition of the NO synthesis provokes rarefaction in the intramyocardial vessels that progresses with the time of administration of L-NAME.

  6. A controlled laboratory environment to study EO signal degradation due to underwater turbulence

    Science.gov (United States)

    Matt, Silvia; Hou, Weilin; Goode, Wesley; Liu, Guigen; Han, Ming; Kanaev, Andrey; Restaino, Sergio

    2015-05-01

    Temperature microstructure in the ocean can lead to localized changes in the index of refraction and can distort underwater electro-optical (EO) signal transmission. A similar phenomenon is well-known from atmospheric optics and generally referred to as "optical turbulence". Though turbulent fluctuations in the ocean distort EO signal transmission and can impact various underwater applications, from diver visibility to active and passive remote sensing, there have been few studies investigating the subject. To provide a test bed for the study of impacts from turbulent flows on underwater EO signal transmission, and to examine and mitigate turbulence effects, we set up a laboratory turbulence environment allowing the variation of turbulence intensity. Convective turbulence is generated in a large Rayleigh- Bénard tank and the turbulent flow is quantified using high-resolution Acoustic Doppler Velocimeter profilers and fast thermistor probes. The turbulence measurements are complemented by computational fluid dynamics simulations of convective turbulence emulating the tank environment. These numerical simulations supplement the sparse laboratory measurements. The numerical data compared well to the laboratory data and both conformed to the Kolmogorov spectrum of turbulence and the Batchelor spectrum of temperature fluctuations. The controlled turbulence environment can be used to assess optical image degradation in the tank in relation to turbulence intensity, as well as to apply adaptive optics techniques. This innovative approach that combines optical techniques, turbulence measurements and numerical simulations can help understand how to mitigate the effects of turbulence impacts on underwater optical signal transmission, as well as advance optical techniques to probe oceanic processes.

  7. STUDY ON PERFORMANCE OF 220 kV M/C MA TOWER DUE TO WIND

    Directory of Open Access Journals (Sweden)

    V. LAKSHMI,

    2011-03-01

    Full Text Available Electric Power is today playing an increasingly important role in the life of the community. In the electric power system the production and transmission of power are two predominant factors. For the purpose of transmission of electricity towers are the main medium with some wires at required distances and altitudes. The remotehydroelectric power plants have given rise to the need for extra high voltage. Prior to 1950, 150 kV electric transmission lines were considered and still higher voltages are being considered these days. Hence it has given rise to the need for relative tall structures such as towers. Thus the study of designing and erection of steel towers has become a challenging task. Transmission line tower normally omprise of several hundred - angle members eccentrically connected. Structural analysis of this type of structure requires extensive data generation. Conventional process of data generation in describing the topology, geometry, load and support conditions are very tedious, time consuming and susceptible to error. In general, most towers may be idealized as statically determinate and analyzed for forces. However, the computations are very lengthy and there are many chances of making errors in such cases. Further if a member is to be redesigned then the entire wind load computations have to be repeated. The computational problem in tower is more acute and tedious as the load depends on the member sizes. A rational and economical design can be made with the help of software’s like STADD Pro 2003, SAP-2000.In this dissertation an attempt is made to develop a software for load calculations on transmission line towers of capacity 220 kV, only as per new code i.e., IS – 802 (Part- I / Sec-1:1995 by considering reliability, security, safety and anti-cascading conditions. In MS-office the EXCEL is used to develop program for wind load calculations on the tower and other loads like wind load on conductor, conductor weights are

  8. Protein denaturation due to the action of surfactants: a study by SAXS and ITC

    Energy Technology Data Exchange (ETDEWEB)

    Oseliero Filho, Pedro Leonidas; Oliveira, Cristiano Luis Pinto de [Universidade de Sao Paulo (USP), SP (Brazil); Pedersen, Jan Skov; Otzen, Daniel Erik [University of Aarhus (Denmark)

    2012-07-01

    Full text: Proteins are the major constituent of biological systems along with carbohydrates, lipids and nucleic acids (DNA and RNA). According to their structure and composition, proteins perform several functions in the organism, starting from the macroscopic level, with participation on the olfaction of animals, down to the cellular level, allocated in the membrane and making the connection between extra and intracellular environment. The function of a protein (which may be enzymatic, hormonal, structural, energetic, transport etc) is related to several factors including its structure (primary, secondary, tertiary or quaternary). Denaturation occurs when the secondary structure and/or tertiary is lost, which is almost always followed by the loss of the associated biological function. Temperature, pH and the action of surfactants influence the process of the denaturation. The influence of surfactants to the protein structure and function is the aim of this work. Therefore we are using an isolated protein, {alpha}-lactalbumin, that is found in the milk and whose function is related to the synthesis of galactose. The purpose is to characterize, in a thermodynamic-structural point of view, the denaturation of alpha-lactalbumin in the presence of surfactants anionic (sodium dodecyl sulfate - SDS), cationic (tetradecyltrimethylammonium bromide - TTAB), zwitterionic (2-diheptanoyl-sn-glycero-3- phosphocholine - DHPC) and nonionic (decyl-{beta}-D-Maltopyranoside - DM). The isothermal titration calorimetry (ITC) technique, which provides information of structural changes from changes in energy, represents the starting point for the study, while the technique of small angle X-ray scattering (SAXS) provides information about the structural characteristics of surfactant-protein complexes formed at each step of the denaturation process. The data analysis is in the initial stage, but it was possible to obtain general parameters related to the complex formed from the

  9. [Experimental study of immune reactivity in Swiss mice due to topical administration of three textile dyes].

    Science.gov (United States)

    Gavăt, C C; Lupuşoru, R V; Ghiciuc, Cristina Mihaela; Lupuşoru, Cătălina Elena

    2010-01-01

    Reactive Red 183, Reactive Red 2 and Reactive Blue 204 (red dye, green dye and blue dye) are three reactive dyes frequently used in textile industry. In some atmospheric conditions ( high temperature, perspiration, pH values, UV/IR radiations), some quantities of these hydrolyzed dyes, could pass from textile clothes directly into the human skin. There were used 4 groups of white Swiss mice (with similar weight and number of both sexes), control group and 3 groups, treated once daily with a retro-auricular application of different reactive dyes. After 14 days of treatment, blood samples were taken from retro-orbitary plexus to assess leukocyte count, phagocytic capacity of peripheral neutrophils, serum opsonic capacity, phagocyte capacity and bactericidal capacity of peritoneal macrophages, splenic T lymphocytes with rossetting capacity and spleen cells forming Jerne plaques. The retro-acuricular and latero-cervical nodes were weighted. Red dye did not influence the weight of the studied nodes, but determined statistically significant modifications on non-specific immune system parameters. Blue and grena dyes determined modifications of weight especially of retroauricular nodes. Grena dye determined important effects of non-specific immune system parameters (serum opsonic capacity, phagocyte capacity and bactericidal capacity of peritoneal macrophages). The blue dye did not determine a biological response. Red and green dye determined important effects on non-specific immune system parameters.

  10. STUDY ON SURGE ARRESTER PERFORMANCE DUE TO LIGHTNING STROKE IN 20 KV DISTRIBUTION LINES

    Directory of Open Access Journals (Sweden)

    Agung Warsito

    2012-02-01

    Full Text Available Electric energy has been transmiting from power station to end user with transmission and distribution lines.Lightning strokes are problems that occure in transmission and distribution lines and make them fault when theelectric energy were transmited. Surge Diverter or Lightning Arrester has been installing to reduce these faults.In this paper the simulation of lightning stroke and lightning arrester performance on distribution lines 20 kVwere done using EMTP (Electromagnetic Transient Program. Some parameters such us impuls voltage andincreasing voltage on distribution line was inverstigated. As case study in this simulation, Mojosongo 1 mainfeeder 20 kV three phase lines were used.The simulation results show that the lightning stroke 20 kA in By1-61-61E-84-9I on S phase at 0,1 ms, makevoltage on S phase was increased about 1,3054 MV. For R phase and T phase will increase of induced voltagewere 0.79539 MV and 0.80484 MV. We also show the performance of MOV Arrester (Metal Oxide Varistor inovercoming lightning stroke trouble, where arrester can decrease voltage up to 15.198 kV on S phase, while atR phase and T phase arrester can decrease voltage up to 11.375 kV and 13.616 kV.

  11. Study of contact dermatitis due to topical medicaments and cosmetics by patch testing

    Directory of Open Access Journals (Sweden)

    Vij Amit

    2007-01-01

    Full Text Available Background: Contact dermatitis is the most common immunological disorder encountered by the dermatologist and it arises when a person develops delayed type of hypersensitivity reaction to a substance coming in contact with his skin. The patch test is at present a helpful test for demonstrating contact type of allergy that identifies the cause of allergic contact dermatitis. Aim: To study the common topical medicaments and cosmetics capable of producing contact dermatitis and value of patch testing in these situations. Materials and Methods: One hundred patients suspected of having contact sensitivity to topical medicaments and common cosmetics were subjected to patch testing with the finished commercial product being used by the patient and the antigens of the Indian Standard Series and Cosmetic series kit. Results: Positivity with patch test of 96.65% was observed in patients with contact dermatitis to topical medicaments, whereas 85% of the patients with cosmetic dermatitis were tested positive. Among the cases with contact dermatitis to topical medicaments, Neomycin was tested positive in more number of patients and among the patients with cosmetic dermatitis; Kum-Kum powder and Fairness cream were tested positive in more number of patients. Conclusion: It is well known that topical medicaments are known to produce contact dermatitis; the cosmetics that are claimed to be very safe by their manufacturers do not stay much behind in doing so.

  12. Study of Microstructure Degradation of Boiler Tubes Due To Creep for Remaining Life Analysis

    Directory of Open Access Journals (Sweden)

    Kavita Sankhala

    2014-07-01

    Full Text Available In the current scenario of power shortage in India, the main objective is to ensure availability of power plant and increasing its reliability. During assessment ,testing and inspection a simple question has to be asked again and again‖ How long the particular power plants can be operated safely and cost-effectively with satisfying increased requirements and operational availability with reduced pollutant emissions, even after their designed life. So to answer this important question regarding the operational capability of the existing plant the remaining life analysis (RLA has to be done. The condition of the plant equipments can be assessed only by way of a RLA methodology. On the basis of RLA proper decision can be made about the plants safety and availability. There are many methods to carry out the RLA of the critical components out of which ―microstructure study‖ is a method. In this paper we have tried to outline the RLA procedures and review the various damage mechanisms based on microstructure study. It is also presents the microstructure changes and properties of 106720 service hour exposed boiler tube in a 120 MW boiler of a thermal power plant.

  13. Study of Dynamic Buckling of FG Plate Due to Heat Flux Pulse

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    Czechowski L.

    2015-02-01

    Full Text Available The paper deals with a FEM analysis of dynamic buckling of functionally graded clamped plates under heat flux loading with huge power. The materials of structures as well as their properties are varying in each layer across the plate thickness formulated by the power law distribution. The heat flux was applied evenly to the whole ceramic surface. The analysis was developed in the ANSYS 14.5 software. The duration of the heat flux loading equal to a period of natural fundamental flexural vibrations of given structures was taken into consideration. To implement large deflections of structures, the Green-Lagrange nonlinear-displacement equations and the incremental Newton-Raphson algorithm were applied. An evaluation of the dynamic response of structures was carried out on basis of the Budiansky-Hutchinson criterion. The studies were conducted for different volume fraction distributions and different shapes of the heat flux loading. The computation results of the heat flux versus maximal plate deflection are shown and discussed.

  14. The change in mutagenicity:study on surface water of Qiantang River due to tide

    Institute of Scientific and Technical Information of China (English)

    WuNX; YangYM

    2002-01-01

    The Qiangtang River lies in Zhejiang Province of China.In this study,the genotoxicity of surface water samples from five sites along the river were detected using Ames test(TA98,TA100±S9),comet(SCGE) test and cytokinesis-block micronucleus(CBMN) tesdt(-S9) in the human peripheral lymphocytes in vitro.The results indicated that in upstream samples (first site) during falling-tide was found slight mutagenicity in TA98 strain with S9 and without S9.The mutagenicity of samples from the second to the fifth site was gradually stronger.Except the first site sample,the micronucleated cell rates of the other four samples during falling-tide significantly increased in CBMN test,and the extent of migration of DNA fragments of the four samples was found to be significantly different from control group.In the upstream(first site) samples during flow-tide were found no mutagen by three short-term tests.But the other four samples were found more stronger mutagenicity in TA98 strain with S9 than that during falling-tide.The micronucleated cell rates and the extent of migration of DNA fragments of the samples were sdignificantly high than that during falling-tide too.

  15. Evaluation of hydrochemical changes due to intensive aquifer exploitation: case studies from Mexico.

    Science.gov (United States)

    Esteller, M V; Rodríguez, R; Cardona, A; Padilla-Sánchez, L

    2012-09-01

    The impact of intensive aquifer exploitation has been observed in numerous places around the world. Mexico is a representative example of this problem. In 2010, 101 out of the 653 aquifers recognized in the country, showed negative social, economic, and environmental effects related to intensive exploitation. The environmental effects include, among others, groundwater level decline, subsidence, attenuation, and drying up of springs, decreased river flow, and deterioration of water quality. This study aimed at determining the hydrochemical changes produced by intensive aquifer exploitation and highlighting water quality modifications, taking as example the Valle de Toluca, Salamanca, and San Luis Potosi aquifers in Mexico's highlands. There, elements such as fluoride, arsenic, iron, and manganese have been detected, resulting from the introduction of older groundwater with longer residence times and distinctive chemical composition (regional flows). High concentrations of other elements such as chloride, sulfate, nitrate, and vanadium, as well as pathogens, all related to anthropogenic pollution sources (wastewater infiltration, irrigation return flow, and atmospheric pollutants, among others) were also observed. Some of these elements (nitrate, fluoride, arsenic, iron, and manganese) have shown concentrations above Mexican and World Health Organization drinking water standards.

  16. [Hearing loss in adolescents due to leisure noise. The OHRKAN study].

    Science.gov (United States)

    Twardella, D; Perez Alvarez, C; Steffens, T; Fromme, H; Raab, U

    2011-08-01

    Alarming reports have been published about hearing loss in adolescents, and increasing leisure time noise exposure has been blamed. If the exposure limits from the Noise at Work Regulations are applied, discotheque music as well as music from portable music players are associated with the risk of hearing loss. The empirical evidence for this association, however, is not sufficient. Not even an increase in the prevalence of noise-induced hearing loss among adolescents can be documented. OHRKAN is a prospective cohort study aimed to produce information on the prevalence of hearing loss as well as its risk factors in adolescents. Currently, a total of 2,240 pupils in grade 9 at schools in the city of Regensburg, Germany, have been recruited. Data on noise exposure were collected using standardized questionnaires. In addition, hearing status was assessed by medical examination including tympanometry, audiometry, and distortion-product otoacoustic emissions. Developments in noise exposure as well as hearing status will be assessed in follow-up data collections. Independent of this empirical assessment preventive measures are already needed now to reduce the risk of hearing loss in adolescents and young adults.

  17. Experimental Studies of Dynamic Fault Weakening Due to Thermal Pressurization of Pore Fluids

    Science.gov (United States)

    Goldsby, David; Tullis, Terry; Platt, John; Okazaki, Keishi

    2016-04-01

    High-velocity friction experiments and geophysical observations suggest that mature faults weaken dramatically during seismic slip. However, while many coseismic weakening mechanisms have been proposed, it is still unclear which mechanisms are most important or how the efficiency of weakening varies within the seismogenic zone. Thermal pressurization is one possible coseismic weakening mechanism driven by the thermal expansion of native pore fluids, which leads to elevated pore pressures and significant coseismic weakening. While thermal pressurization has been studied theoretically for many decades, and invoked in recent earthquake simulations, its activation in laboratory experiments has remained elusive. Several high-speed friction studies have yielded indirect evidence for thermal pressurization, yet none has directly linked with existing theoretical models or the relevant physical parameters, such as permeability, slip, and slip rate, that control the weakening rate. To fill this gap, we are conducting thermal pressurization experiments on fluid-saturated, low-permeability rocks (Frederick diabase) at slip rates up to ~5 mm/s, at constant confining pressures in the range 21-149 MPa and initial imposed pore pressures in the range 10-25 MPa. The impractically low permeability of the as-is diabase, ~10-23 m2, is increased prior to the test by thermal cracking, yielding measured permeabilities in the range 1.3*10-18 to 6.1*10-19 m2. These values of permeability are high enough to allow sample saturation over one to several days, but low enough to confine the elevated pore pressures generated by frictional heating during rapid sliding. Our experiments reveal a rapid decay of shear stress following a step-change in velocity from 10 μm/s to 4.8 mm/s. In one test, the decrease in shear stress of ~25% over the first 28 mm of slip at 4.8 mm/s agrees closely with the theoretical solution for slip on a plane (Rice [2006]), with an inferred slip-weakening distance of ~500

  18. Effect of probucol on vascular remodeling due to atherosclerosis in rabbits: an intravascular ultrasound study

    Institute of Scientific and Technical Information of China (English)

    LI Ting-ting; XIE Yi; GUO Yuan; TIAN Hong-bo; ZHANG Jian-ning; PENG Jie; ZHANG Yun

    2011-01-01

    Background Probucol is known to reduce the development of atherosclerotic lesions, but its impact on vascular remodeling associated with de novo atherosclerosis is incompletely understood. We therefore examined the effect of probucol on vascular remodeling in a rabbit model of established atherosclerosis.Methods Aortic atherosclerosis was induced by a combination of endothelial injury and 10 weeks' atherogenic diet. Animals were then randomized to receive the foregoing diet without or with 1% (wt/wt) probucol for 16 weeks. At the end of week 26, in vivo intravascular ultrasound, pathological, immunohistochemical and gene expression studies were performed.Results Probucol significantly decreased vessel cross-sectional area, plaque area and plaque burden without effect on lumen area. More negative remodeling and less positive remodeling occurred in the abdominal aortas of probucol group than the control group (56% vs. 21%, 18% vs. 54%, respectively, both P<0.01). In addition, the probucol group showed a smaller mean remodeling index relative to the control group (0.93 ± 0.13 vs. 1.05 ±0.16, P<0.01). Furthermore, probucol treatment decreased macrophage infiltration, inhibited apoptosis of cells within plaques, and reduced the production of matrix metalloproteinases-2, -9, cathepsin K and cathepsin S (all P<0.01).Conclusions These findings suggest that probucol may attenuate the enlargement of atherosclerotic vessel walls and be associated with a negative remodeling pattern without affecting the lumen size. This effect may involve inhibition of extracellular matrix degradation and prevention of apoptosis in atherosclerotic plaques.

  19. Percutaneous nerve stimulation in chronic neuropathic pain patients due to spinal cord injury: a pilot study.

    Science.gov (United States)

    Kopsky, David Jos; Ettema, Frank Willem Leo; van der Leeden, Marike; Dekker, Joost; Stolwijk-Swüste, Janneke Marjan

    2014-03-01

    The long-term prognosis for neuropathic pain resolution following spinal cord injury (SCI) is often poor. In many SCI patients, neuropathic pain continues or even worsens over time. Thus, new treatment approaches are needed. We conducted a pilot study to evaluate the feasibility and effect of percutaneous (electrical) nerve stimulation (P(E)NS) in SCI patients with chronic neuropathic pain. In 18 weeks, 12 P(E)NS treatments were scheduled. Assessment with questionnaires was performed at baseline (T0), after 8 weeks (T8), 18 weeks (T18), and 12 weeks post-treatment (T30). From 26 screened patients, 17 were included. In total, 91.2% questionnaires were returned, 2 patients dropped out, and 4.2% of the patients reported minor side effects. Pain scores on the week pain diary measured with the numerical rating scale improved significantly at T8, from 6.5 at baseline to 5.4, and were still significantly improved at T18. Pain reduction of ≥ 30% directly after a session was reported in 64.6% sessions. In total, 6 patients experienced reduction in size of the pain areas at T18 and T30, with a mean reduction of 45.8% at T18 and 45.3% at T30. P(E)NS is feasible as an intervention in SCI patients and might have a positive effect on pain reduction in a part of this patient group. © 2013 The Authors Pain Practice © 2013 World Institute of Pain.

  20. Torque differences due to the material variation of the orthodontic appliance: a finite element study.

    Science.gov (United States)

    Papageorgiou, Spyridon N; Keilig, Ludger; Vandevska-Radunovic, Vaska; Eliades, Theodore; Bourauel, Christoph

    2017-12-01

    Torque of the maxillary incisors is crucial to occlusal relationship and esthetics and can be influenced by many factors. The aim of this study was to assess the relative influence of the material of the orthodontic appliance (adhesive, bracket, ligature, and wire) on tooth displacements and developed stresses/strains after torque application. A three-dimensional upper right central incisor with its periodontal ligament (PDL) and alveolus was modeled. A 0.018-in. slot discovery® (Dentaurum, Ispringen, Germany) bracket with a rectangular 0.018 x 0.025-in. wire was generated. The orthodontic appliance varied in the material of its components: adhesive (composite resin or resin-modified glass ionomer cement), bracket (titanium, steel, or ceramic), wire (beta-titanium or steel), and ligature (elastomeric or steel). A total of 24 models were generated, and a palatal root torque of 5° was applied. Afterwards, crown and apex displacement, strains in the PDL, and stresses in the bracket were calculated and analyzed. The labial crown displacement and the palatal root displacement of the tooth were mainly influenced by the material of the wire (up to 150% variation), followed by the material of the bracket (up to 19% variation). The magnitude of strains developed in the PDL was primarily influenced by the material of the wire (up to 127% variation), followed by the material of the bracket (up to 30% variation) and the ligature (up to 13% variation). Finally, stresses developed at the bracket were mainly influenced by the material of the wire (up to 118% variation) and the bracket (up to 59% variation). The material properties of the orthodontic appliance and all its components should be considered during torque application. However, these in silico results need to be validated in vivo before they can be clinically extrapolated.

  1. Epidemiology of Ocular Infection Due to Bacteria and Fungus – A Prospective Study

    Directory of Open Access Journals (Sweden)

    AK Verma

    2008-07-01

    Full Text Available A total number of 400 cases of eye infection were studied. Among them, 250 were conjunctivitis (59.2%,120were keratitis (53.34% 15 were endophthalmitis (26.67% and 15 were suffering from other infections(40%. The corneal scrapping, conjunctival swab and biopsy material ( endophthalmitis cases was collectedasceptically. The material was examined using 10% Potassium hydroxide, Gram staining and Giemsastaining. The specimens were cultured on sheeps’ blood agar, chocolate agar and sabourauds’ dextroseagar. In the bacterial cause of eye infection Staphylococcus aureus (19.13% was the most commonlyisolated organism and other pathogens isolated were Streptococcus pneumoniae (10.93%, Streptococcuspyogens (0.55%, Pseudomonas aeruginosa (4.92%, Klebsiella species(2.74%, Escherichia colli (1.10%and Proteus mirabilis (0.55%. Among the opportunistic pathogens, Staphylococcus epidermidis, (19.13%were the most common isolate followed by Acinetobacter species(2.74%. Alkaligenes faecalis (1.10%,Staphylococcus saprophyticus (0.55%, Staphylococcus cohnii (0.55%, Staphylococcus haemolyticus(0.55%. In the endopthalmitis patients only Pseudomonas aeruginosa (20% and Staphylococcusepidermidis (6.67% were isolated. In the fungal keratitis, the total fungal isolates were 32.50%. Amongthem Aspergillus species (56.42% was the most common fungus isolated followed by Curvurlaria (17.95%,Cladosporium (7.70%, Candida species (5.13%, Fusarium (5.13%, Alternaria (5.13%, Penicillium(2.57%. Fungal infection is a life threatening condition, which needs early diagnosis and treatment tosave the patients’ eye. Staphylococcus aureus and Staphylococcus epidermidis are still the most commonisolates among the known and opportunistic pathogens in ocular infection. Pseudomonas is the mostcommon cause of endophthalmitis. Aspergillus remains most common cause for fungal keratitis.

  2. Gender and age differences in the recurrence of sickness absence due to common mental disorders : a longitudinal study

    NARCIS (Netherlands)

    Koopmans, P.C.; Roelen, C.A.M.; Bultmann, U.; Hoedeman, R.; van der Klink, J.J.L.; Groothoff, J.W.

    2010-01-01

    Background: Common mental disorders (CMDs) are an important cause of sickness absence and long-term work disability. Although CMDs are known to have high recurrence rates, little is known about the recurrence of sickness absence due to CMDs. The aim of this study was to investigate the recurrence of

  3. Perinatal morbidity and mortality due to preterm deliveries in a referral hospital, in rural India: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Mahesh R. Asalkar

    2013-08-01

    Conclusion: This manuscript describes the design, methodology used and the three years result of this cross sectional study to analyze and audit the perinatal mortality and morbidity due to preterm deliveries in a tertiary care teaching hospital of rural area of Maharashtra. [Int J Reprod Contracept Obstet Gynecol 2013; 2(4.000: 555-561

  4. Incidence of Hospitalization Due to Child Maltreatment in Taiwan, 1996-2007: A Nationwide Population-Based Study

    Science.gov (United States)

    Chiang, Wan-Lin; Huang, Yu-Tung; Feng, Jui-Ying; Lu, Tsung-Hsueh

    2012-01-01

    Objectives: Little is known regarding the epidemiology of child maltreatment in Asian countries. This study aimed to examine the incidence of hospitalization coded as due to child maltreatment in Taiwan. Methods: We used inpatient claims data of the National Health Insurance for the years 1996 through 2007 for estimation. Hospitalization of…

  5. Study of angular momentum variation due to entrance channel effect in heavy ion fusion reactions

    Science.gov (United States)

    Kumar, Ajay

    2014-05-01

    A systematic investigation of the properties of hot nuclei may be studied by detecting the evaporated particles. These emissions reflect the behavior of the nucleus at various stages of the deexcitation cascade. When the nucleus is formed by the collision of a heavy nucleus with a light particle, the statistical model has done a good job of predicting the distribution of evaporated particles when reasonable choices were made for the level densities and yrast lines. Comparison to more specific measurements could, of course, provide a more severe test of the model and enable one to identify the deviations from the statistical model as the signature of other effects not included in the model. Some papers have claimed that experimental evaporation spectra from heavy-ion fusion reactions at higher excitation energies and angular momenta are no longer consistent with the predictions of the standard statistical model. In order to confirm this prediction we have employed two systems, a mass-symmetric (31P+45Sc) and a mass-asymmetric channel (12C+64Zn), leading to the same compound nucleus 76Kr* at the excitation energy of 75 MeV. Neutron energy spectra of the asymmetric system (12C+64Zn) at different angles are well described by the statistical model predictions using the normal value of the level density parameter a = A/8 MeV-1. However, in the case of the symmetric system (31P+45Sc), the statistical model interpretation of the data requires the change in the value of a = A/10 MeV-1. The delayed evolution of the compound system in case of the symmetric 31P+45Sc system may lead to the formation of a temperature equilibrated dinuclear complex, which may be responsible for the neutron emission at higher temperature, while the protons and alpha particles are evaporated after neutron emission when the system is sufficiently cooled down and the higher g-values do not contribute in the formation of the compound nucleus for the symmetric entrance channel in case of charged

  6. Assessment of soil loss and nutrient depletion due to cassava harvesting: A case study from low input traditional agriculture

    Directory of Open Access Journals (Sweden)

    R. Sumithra

    2013-09-01

    Full Text Available Cassava is a major food crop for farmers and especially small holder farmers and cultivated under low input other than the irrigation. It is cultivated as mono crop or intercrop at early stage and cultivating throughout the year. It is harvested carefully because of cyanogenic glucosides and consumed with in day. Easy and un-damageable uprooting of the tuber mainly depends on soil moisture, texture and agronomic practices. The study was focused with the objectives of the assessment of soil loss due to the harvesting of cassava roots tubers under low input agriculture, and to estimate the amount of plant nutrients loss due to crop harvest for cassava. Also the observation was made the correlation between the soil loss and physical characters of the tuber, soil texture and agronomic practices. Average plant specific soil loss due to crop harvesting was 80. 7 g root−1 and crop specific soil loss due to crop harvesting was 7. 64 kg ha−1 harvest−1 loss in Valliagmam area in Jaffna, Sri Lanka. Soil moisture content at harvesting time was a significant factor that explained the variations in the soil lost at cassava harvesting. Soil moisture has linear positive relationship with average plant specific soil loss due to crop harvesting. Soil nutrient loss during cassava harvesting by removal of adhering soil with root tuber was 1. 15 kg of N, 1. 99 kg of P and 2. 91 kg of K ha−1 harvest−1. Application of fertilizer is important since considerable amount nutrient loss was observed due to soil loss due to crop harvest.

  7. Is transition zone index useful in assessing bladder outflow obstruction due to benign prostatic hyperplasia?: A prospective study

    Directory of Open Access Journals (Sweden)

    S L Sailo

    2006-01-01

    Full Text Available BACKGROUND: Benign prostatic enlargement (BPE is the commonest cause of bladder outlet obstruction in men above 50 years of age. Though pressure-flow study is the gold standard in establishing outlet obstruction, it is associated with definite morbidity. Several noninvasive parameters are described to diagnose outlet obstruction due to BPE and evaluate treatment efficacy. AIM: We studied the role of transitional zone index (TZI in assessing bladder outlet obstruction (BOO due to BPE. SETTING AND DESIGN: Prospective hospital-based cross-sectional diagnostic study. MATERIALS AND METHODS: Thirty-five men aged between 50 and 77 years with untreated lower urinary tract symptoms due to BPE were studied. Patients with prostate cancer, prostatitis, active UTI urethral stricture, neurovesical dysfunction and diabetes mellitus were excluded. All patients underwent a standard assessment using the American Urological Association (AUA symptom score, uroflow, pressure-flow (PF study and transrectal ultrasound (TRUS estimation of TZI. Investigators undertaking PF studies and TRUS were blinded to the investigation of others. From the PF studies, Abrams Griffith (AG number was calculated. Based on this, patients were grouped into obstructed (AG>40 and unobstructed (AG< 40 groups. STATISTICAL ANALYSIS: TZI was calculated and compared with PF studies using Mann-Whitney U test, logistic regression analysis and receiver operator characteristic curve (ROC. RESULTS: The mean age was 63.2 years (SD. The mean AUA scores and peak flow rate were 16.7 and 7.5 ml/sec, respectively. Of the 35 men, 21 were obstructed and 14 were unobstructed. TZI was not significantly different between the two groups, while the differences in age, AUA symptom score, prostate volume and TZ volume were statistically significant. Logistic regression model did not show any independent effect of TZI in predicting obstruction. ROC curve showed a poor overall accuracy in diagnosing obstruction due

  8. Physiotherapy and a Homeopathic Complex for Chronic Low Back Pain Due to Osteoarthritis: A Randomized, Controlled Pilot Study

    OpenAIRE

    Pellow, Janice

    2016-01-01

    Abstract:Context: Osteoarthritis (OA) is a common cause of chronic low back pain (CLBP) and can be managed with the use of drug therapy and physiotherapy. Homeopathic remedies may assist in the management of OA; however, research that supports their effectiveness is limited. Objectives: The study aimed to investigate the efficacy of a homeopathic complex in combination with physiotherapy in the treatment of CLBP due to OA. Design: The study was a six-week, randomized, double-blind, placebo-co...

  9. Active surveillance of visual impairment due to adverse drug reactions: findings from a national study in the United Kingdom.

    Science.gov (United States)

    Cumberland, Phillippa M; Russell-Eggitt, Isabelle; Rahi, Jugnoo S

    2015-02-01

    As visual impairment (VI) due to adverse drug reactions (ADR) is rare in adults and children, there is an incomplete evidence base to inform guidance for screening and for counseling patients on the potential risks of medications. We report on suspected drugs and the eye conditions found in a national study of incidence of diagnosis of visual impairment due to suspected ADR. Case ascertainment was via the British Ophthalmological Surveillance Unit (BOSU), between March 2010 and February 2012, with follow-up after 6 months. any child or adult with bilateral or unilateral visual impairment due to a suspected ADR, using distance acuity worse than Snellen 6/18 (logMAR 0.48) in the better eye (bilateral) or affected eye (unilateral). Anonymized patient information on potential cases was provided by managing ophthalmologists, comprising visual status before and after suspected ADR, ophthalmic condition attributable to the ADR, preexisting eye disease and prescribed medications at the time of the ADR. Permanency and causality of the visual impairment were confirmed by the managing clinician, after 6 months, using the WHO Uppsala Monitoring Committee criteria. Over 2 years, 36 eligible cases were reported of whom 23 had permanent VI. While most cases were due to drugs known to have adverse side-effects, some were unanticipated sporadic cases. Visual impairment due to ADRs is rare. However, with for example, increasing polypharmacy in the elderly, monitoring of ocular ADRs, although challenging, is necessary.

  10. Histopathological analysis of the cutaneous changes due to Kangri use in Kashmiri population: A hospital based study

    Directory of Open Access Journals (Sweden)

    Iffat Hassan

    2013-01-01

    Full Text Available Background: Kangri cancer is peculiar to the valley of Kashmir as people of all age groups are accustomed to warm their bodies by the use of Kangri baskets.The clinical spectrum of skin cancer in the Kashmir valley is entirely different from the rest of the country, which could be attributed to the use of Kangri in this geographical region. [1],[2] Aims: Histopathological analysis of the cutaneous changes due to kangri use in Kashmiri population. Materials and Methods: This is a prospective hospital based study. All the patients attending the outpatient department of Dermatology, STD and Leprosy at SMHS Hospital, an associated hospital of govt. medical college in Srinagar and presented with suspicious lesions (i.e., erythema ab igne, papular or nodular skin growths due to Kangri use were taken up for the study. A detailed history including the use of Kangri and a physical examination was done in each patient followed by a histopathological examination in case of suspicious lesions. Results: The cutaneous changes which were observed during the study period of 8 months were erythema ab igne, bowen′s disease and squamous cell carcinoma. Conclusion: Although this is a preliminary study we will be studying more of such changes caused due to Kangri use in the future.

  11. Study of Noise Pollution Due To Railway and Vehicular Traffic at Level Crossing and Its Remedial Measures

    Directory of Open Access Journals (Sweden)

    Anurag V. Tiwari

    2013-01-01

    Full Text Available Amravati is second largest and very important city in Vidarbha region. As Amravati is developing area and a good education centre there is a rapid urbanization and alarming growth of population is causing serious environmental problems. Noise is one of the environmental problem that uncomforts in daily life. Noise pollution has become major concern for communities living within the city. Considering the sudden increase in the number of trains from Amravati railway station, rapid growth and illness effect due to noise pollution, there is need to study noise pollution in Amravati. In this study an attempt is made to monitor the noise pollution due to railway and vehicular traffic at one of the major intersection Rajapeth using digital sound meter along with the collection of traffic volume data and train frequency. The variation in the noise level due to railway crossing, traffic flow and traffic volume data in the peak hours are studied and presented in the graphical form for the selected location. The study also includes the remedies which can be provided for minimizing the noise pollution.

  12. A One-Year Study of Mortality Due to Drug and Chemical Poisoning in Sina Hospital of Hamadan

    Directory of Open Access Journals (Sweden)

    S. Afzali

    2003-10-01

    Full Text Available Every year many people refer to emergency department due to poisoning and some of them be threated and some die because of the intensity of adverse effect. Most patients who refer to emergency department are those who commit intentionally for Suicide attempt and another group are those who are poisoned due to drug overdose. In this study we reviewed annual number of death due to drug and chemical poisonings that attend to Sina hospital, Hamadan in the year 2001. This retrospective study was gather based on poisoned file who refer to emergency department and died due to intensity of adverse effects of poisoning. The results show that out of 1079 patients ,47 cases have died because of intensity of adverse effects. Mortality rate in male was 74.5% and in female was 25.5%. 68.1% was seen in those patients who committed suicide and in the second degree was seen in drug abuser(21.3%. The greatest number of death (12 patients was seen between 10-20 year old and also above 50. Poisons mostly used organophosphates – opiates and herbicides successively , and other drugs and chemical came after them. The most common adverse effect leading to death was respiratory depression. In most cases toxicological examinations on dead body were negative, when the results of such examination were positive the majority of reports were about arsenic and methanol. The highest rate of death (55.3% occurred in those patients who referred to the hospital more than 6 hours after poisoning. The results showed that the rate of poisoning due to organophosphate insecticides and opiates are higher than other drugs in Hamadan.

  13. Risk factors for hospitalization due to community-acquired sepsis - a population-based case-control study

    DEFF Research Database (Denmark)

    Henriksen, Daniel Pilsgaard; Pottegård, Anton; Laursen, Christian B

    2015-01-01

    BACKGROUND: The aim of the study was to estimate risk factors for hospitalization due to sepsis and to determine whether these risk factors vary by age and gender. METHODS: We performed a population-based case-control study of all adult patients admitted to a medical ED from September 2010...... to August 2011. Controls were sampled within the hospital catchment-area. All potential cases were manually validated using a structured protocol. Vital signs and laboratory values measured at arrival were registered to define systemic inflammatory response syndrome and organ dysfunction. Multivariable...... logistic regression was used to elucidate which predefined risk factors were associated with an increased or decreased risk hospitalization due to sepsis. RESULTS: A total of 1713 patients were admitted with sepsis of any severity. The median age was 72 years (interquartile range: 57-81 years) and 793 (46...

  14. Surgical Management of Multijoint Septic Arthritis due to Rat-Bite Fever in a Pediatric Patient: A Case Study

    Directory of Open Access Journals (Sweden)

    Adam M. Wegner

    2017-01-01

    Full Text Available In the United States, rat-bite fever is a rare systemic illness principally caused by Streptobacillus moniliformis, an organism found in the nasopharyngeal flora of rodents. Infection through direct exposure to rat excreta such as saliva, urine, or feces can lead to fever, rash, and an asymmetric migratory polyarthritis. As rodents are becoming more popular as pets, more pediatric cases are being documented. We report a pediatric case of delayed onset septic arthritis in the left wrist and right knee due to S. moniliformis from a rat bite. Previously reported pediatric case studies of suppurative arthritis due to S. moniliformis have only involved the hip. This case study demonstrates the importance of a thorough exposure history and consideration of zoonotic infections as a cause of septic arthritis in a pediatric patient that requires antibiotics and surgical intervention.

  15. Feasibility of Using PZT Actuators to Study the Dynamic Behavior of a Rotating Disk due to Rotor-Stator Interaction

    Directory of Open Access Journals (Sweden)

    Alexandre Presas

    2014-07-01

    Full Text Available In this paper, PZT actuators are used to study the dynamic behavior of a rotating disk structure due to rotor-stator interaction excitation. The disk is studied with two different surrounding fluids—air and water. The study has been performed analytically and validated experimentally. For the theoretical analysis, the natural frequencies and the associated mode shapes of the rotating disk in air and water are obtained with the Kirchhoff-Love thin plate theory coupled with the interaction with the surrounding fluid. A model for the Rotor Stator Interaction that occurs in many rotating disk-like parts of turbomachinery such as compressors, hydraulic runners or alternators is presented. The dynamic behavior of the rotating disk due to this excitation is deduced. For the experimental analysis a test rig has been developed. It consists of a stainless steel disk (r = 198 mm and h = 8 mm connected to a variable speed motor. Excitation and response are measured from the rotating system. For the rotating excitation four piezoelectric patches have been used. Calibrating the piezoelectric patches in amplitude and phase, different rotating excitation patterns are applied on the rotating disk in air and in water. Results show the feasibility of using PZT to control the response of the disk due to a rotor-stator interaction.

  16. Feasibility of using PZT actuators to study the dynamic behavior of a rotating disk due to rotor-stator interaction.

    Science.gov (United States)

    Presas, Alexandre; Egusquiza, Eduard; Valero, Carme; Valentin, David; Seidel, Ulrich

    2014-07-07

    In this paper, PZT actuators are used to study the dynamic behavior of a rotating disk structure due to rotor-stator interaction excitation. The disk is studied with two different surrounding fluids-air and water. The study has been performed analytically and validated experimentally. For the theoretical analysis, the natural frequencies and the associated mode shapes of the rotating disk in air and water are obtained with the Kirchhoff-Love thin plate theory coupled with the interaction with the surrounding fluid. A model for the Rotor Stator Interaction that occurs in many rotating disk-like parts of turbomachinery such as compressors, hydraulic runners or alternators is presented. The dynamic behavior of the rotating disk due to this excitation is deduced. For the experimental analysis a test rig has been developed. It consists of a stainless steel disk (r = 198 mm and h = 8 mm) connected to a variable speed motor. Excitation and response are measured from the rotating system. For the rotating excitation four piezoelectric patches have been used. Calibrating the piezoelectric patches in amplitude and phase, different rotating excitation patterns are applied on the rotating disk in air and in water. Results show the feasibility of using PZT to control the response of the disk due to a rotor-stator interaction.

  17. A retrospective study on the unseen epidemic of road traffic injuries and deaths due to accidents in Mwanza City - Tanzania.

    Science.gov (United States)

    Ngallaba, S E; Majinge, C; Gilyoma, J; Makerere, D J; Charles, E

    2013-06-01

    Sixty percent of the global deaths and injuries occur in the developing world and mostly are due to Road traffic accidents (RTAs. looking at the etiological related factors which include, carelessness of the driver, condition of the vehicle or motorcycle, poor condition of roads, risky behavior of the driver, most of these factors can be prevented to some extent. This study therefore, determined the pattern of cases and deaths due to traffic road accidents in Mwanza City Tanzania. In this retrospective study, records, registers and case notes In the surgical ward and causality, medical records and central police station from 2008 to 2011 were used. The study focused on the two referral hospitals (Sekouture regional hospital and Bugando Medical Center). There were 3450 cases due to accidents reported at both centers (Sekouture regional hospital and Bugando Medical Center of which 3224 (93.4%) had complete information for analysis.2225 (69%) were male and 999 (31%) were female, and the most affected group were male. Among the RTAs2809 cases (87%) were due to motor cycle accidents which were the leading cause of RTAs with case fatality rate of 5% while motor vehicle has case fatality rate of 24% which is 5 times that of motor cycle. Among all RTAs the leading cause of injuries is Motor cycle traffic accidents followed by motor vehicle. RTAs are on increase particularly the motor cycle traffic accidents and has claimed a good number of innocent people's lives however most of them are preventable, therefore driving course to be introduced to motor cycle drivers with emphasize on the road posters signal, rules and regular checkup of their motor cycles especially commercial motor cycle.

  18. Age Related Macular Degeneration and Total Hip Replacement Due to Osteoarthritis or Fracture: Melbourne Collaborative Cohort Study.

    Directory of Open Access Journals (Sweden)

    Elaine W Chong

    Full Text Available Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthritis or fractured neck of femur in the Melbourne Collaborative Cohort Study. 20,744 participants had complete data on both age-related macular degeneration assessed from colour fundus photographs taken during 2003-2007 and total hip replacement. Total hip replacements due to hip osteoarthritis and fractured neck of femur during 2001-2011 were identified by linking the cohort records to the Australian Orthopedic Association National Joint Replacement Registry. Logistic regression was used to examine the association between age-related macular degeneration and risk of total hip replacement due to osteoarthritis and fracture separately, adjusted for confounders. There were 791 cases of total hip replacement for osteoarthritis and 102 cases of total hip replacement due to fractured neck of femur. After adjustment for age, sex, body mass index, smoking, and grouped country of birth, intermediate age-related macular degeneration was directly associated with total hip replacement for osteoarthritis (odds ratio 1.22, 95% CI 1.00-1.49. Late age-related macular degeneration was directly associated with total hip replacement due to fractured neck of femur (odds ratio 5.21, 95% CI2.25-12.02. The association between intermediate age-related macular degeneration and an increased 10-year incidence of total hip replacement due to osteoarthritis suggests the possibility of similar inflammatory processes underlying both chronic diseases. The association of late age-related macular degeneration with an increased 10-year incidence of total hip replacement due to fractured

  19. Age Related Macular Degeneration and Total Hip Replacement Due to Osteoarthritis or Fracture: Melbourne Collaborative Cohort Study.

    Science.gov (United States)

    Chong, Elaine W; Wang, Yuanyuan; Robman, Liubov D; Aung, Khin Zaw; Makeyeva, Galina A; Giles, Graham G; Graves, Stephen; Cicuttini, Flavia M; Guymer, Robyn H

    2015-01-01

    Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthritis or fractured neck of femur in the Melbourne Collaborative Cohort Study. 20,744 participants had complete data on both age-related macular degeneration assessed from colour fundus photographs taken during 2003-2007 and total hip replacement. Total hip replacements due to hip osteoarthritis and fractured neck of femur during 2001-2011 were identified by linking the cohort records to the Australian Orthopedic Association National Joint Replacement Registry. Logistic regression was used to examine the association between age-related macular degeneration and risk of total hip replacement due to osteoarthritis and fracture separately, adjusted for confounders. There were 791 cases of total hip replacement for osteoarthritis and 102 cases of total hip replacement due to fractured neck of femur. After adjustment for age, sex, body mass index, smoking, and grouped country of birth, intermediate age-related macular degeneration was directly associated with total hip replacement for osteoarthritis (odds ratio 1.22, 95% CI 1.00-1.49). Late age-related macular degeneration was directly associated with total hip replacement due to fractured neck of femur (odds ratio 5.21, 95% CI2.25-12.02). The association between intermediate age-related macular degeneration and an increased 10-year incidence of total hip replacement due to osteoarthritis suggests the possibility of similar inflammatory processes underlying both chronic diseases. The association of late age-related macular degeneration with an increased 10-year incidence of total hip replacement due to fractured neck of femur may be

  20. The study of variations of low energy cosmic helium's flux (up to 6 MeV) due to solar activity

    Science.gov (United States)

    Shayan, M.; Davoudifar, P.; Bagheri, Z.

    2017-04-01

    In General, the flux of low energy cosmic rays varies with time due to solar activities. The cosmic particle fluxes were studied using data of satellites near the Earth. In this work, first we studied the variations of particle fluxes from 1 Jan to 31 Dec 2000 and 35 events were selected. Then we proposed a relation for cosmic particle flux as a function of time and rigidity in the time of approaching ejecta to the Earth. The coefficients of the relation were calculated using experimental data of particle fluxes from ACE satellite. Finally, we compare time variations of these coefficients for different events.

  1. DUE PERMAFROST: A Circumpolar Remote Sensing Service for Permafrost - Evaluation Case Studies and Intercomparison with Regional Climate Model Simulations

    Science.gov (United States)

    Heim, B.; Bartsch, A.; Elger, K. K.; Rinke, A.; Matthes, H.; Zhou, X.; Klehmet, K.; Buchhorn, M.; Soliman, A. S.; Duguay, C. R.

    2013-12-01

    stakeholders and the IPA, and the ongoing evaluation of the remote sensing derived products make the DUE Permafrost products accepted by the scientific community. The Helmholtz Climate Initiative REKLIM (Regionale KlimaAnderungen/Regional climate change) is a climate research program where regional observations and process studies are coupled with model simulations (http://www.reklim.de/en/home/). The ESA DUE Permafrost User workshops initiated the use of the DUE time series within the REKLIM framework for inter-comparison experiments in order to assist the evaluation of calculated parameter fields of models. Within the REKLIM framework we spatio-temporally compare the geophysical surface parameters simulated by regional climate models with the spatio-temporal variability of Earth Observational remote sensing products. Earth Observational remote sensing products are: DUE Permafrost, DUE GlobSnow (http://www.globsnow.info) and the MODIS albedo product (MOD 43). We show intercomparison substudies on simulated fields of surface temperature and ground frozen, non-frozen state simulated by the regional climate models HIRHAM for the circumpolar domain and COSMO-CLM for Central Siberia.

  2. STUDY OF HISTOPATHOLOGICAL CHANGES IN LUNGS AND KIDNEYS FOLLOWING DEATH DUE TO BURNS AT VARYING PERIODS OF SURVIVAL

    Directory of Open Access Journals (Sweden)

    Sathikumar M

    2016-07-01

    Full Text Available BACKGROUND In the present study, aetiological factors leading to death from burns; pattern of burns; the environment in which the incident occurs, depth and percentage of burns, effect of clothing on the distribution and extent of burns sustained. The changes occurring in the internal organs like lungs and kidneys of victims died of burns and period of survival after sustaining burns are studied in detail. With this background, the lungs and kidneys of the victims died of burns were subjected for detailed histopathological examination and the various pathological changes occurred in them are studied. MATERIALS AND METHODS The study was conducted at Government Medical College, Kozhikode. During the period of 1 year, 60 cases of death due to burn from the fire were studied. RESULTS It was noted that majority of lung specimen showed histopathological changes like alveolar oedema and congestion, bronchiolar congestion and haemorrhage, interstitial oedema, haemorrhage, congestion, and inflammation. The kidneys showed acute tubular necrosis and haemorrhage, glomerular haemorrhage and oedema, interstitial necrosis, haemorrhage and congestion as histopathological changes. DISCUSSION AND CONCLUSION From this study at different periods of survival in burns of two organs, the histopathological changes of lungs and kidneys are more prominent. When the period of survival increased, i.e., these organs undergoes severe and very severe degree of changes. Most of the subject died of acute pulmonary oedema, bronchopneumonia, renal failure, and septicaemia in late period of survival. Hence, on conclusion from the study that the lungs and kidneys are two internal organs, which show constant histopathological changes in cases of death due to burns irrespective of the period of survival and these organs are more important in determining the cause of death.

  3. A study on the effectiveness of a preventive equipment against the fault due to magpies in overhead distribution line

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.M.; Lee, B.S.; Lee, J.B. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    This study examines the applicability of a preventive equipment (liquid grass) to the field. The preventive equipment mass produced already is to prevent the fault due to birds-magpies, and is known for the excellent performance within magpies' living quarters. To assess the practicality of the production, it was mounted on the poles on which the magpie can build a nest with ease, thus the durability, emitting effect of a foul odor and evading temper of magpies were assessed. (author). 16 refs., 8 figs., 6 tabs.

  4. Phonon features in terahertz photoconductivity spectra due to data analysis artifact: A case study on organometallic halide perovskites

    Science.gov (United States)

    La-o-vorakiat, Chan; Cheng, Liang; Salim, Teddy; Marcus, Rudolph A.; Michel-Beyerle, Maria-Elisabeth; Lam, Yeng Ming; Chia, Elbert E. M.

    2017-03-01

    We propose a simple scenario where the superimposed phonon modes on the photoconductive spectra are experimental artifacts due to the invalid formula used in data analysis. By use of experimental and simulated data of CH3NH3PbI3 perovskites as a case study, we demonstrate that a correction term must be included in the approximated thin-film formula used in the literature; otherwise, parts of the spectra with high background permittivity near the phonon-mode resonances might interfere with the transient photoconductivity. The implication of this work is not limited to perovskites but other materials with strong vibrational modes within the THz spectral range.

  5. A comparative study of bridge damage due to the Wenchuan,Northridge, Loma Prieta and San Fernando earthquakes

    Institute of Scientific and Technical Information of China (English)

    Wang Zhiqiang; George C. Lee

    2009-01-01

    A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes is described in this paper. Typical ground motion effects considered include large ground fault displacement, liquefaction, landslide, and strong ground shaking. Issues related to falling spans, inadequate detailing for structural ductility and complex bridge configurations are discussed within the context of the recent seismic design codes of China and the US. A significant lesson learned from the Great Wenchuan earthquake, far beyond the opportunities to improve the seismic design provisions for bridges, is articulated.

  6. A comparative study of bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes

    Science.gov (United States)

    Wang, Zhiqiang; Lee, George C.

    2009-06-01

    A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes is described in this paper. Typical ground motion effects considered include large ground fault displacement, liquefaction, landslide, and strong ground shaking. Issues related to falling spans, inadequate detailing for structural ductility and complex bridge configurations are discussed within the context of the recent seismic design codes of China and the US. A significant lesson learned from the Great Wenchuan earthquake, far beyond the opportunities to improve the seismic design provisions for bridges, is articulated.

  7. A study on the effectiveness of a preventive equipment against the fault due to magpies in overhead distribution line

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.M.; Lee, B.S.; Lee, J.B. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    This study examines the applicability of a preventive equipment (liquid grass) to the field. The preventive equipment mass produced already is to prevent the fault due to birds-magpies, and is known for the excellent performance within magpies' living quarters. To assess the practicality of the production, it was mounted on the poles on which the magpie can build a nest with ease, thus the durability, emitting effect of a foul odor and evading temper of magpies were assessed. (author). 16 refs., 8 figs., 6 tabs.

  8. A Two Dimensional Infinite Element Model to Study Temperature Distribution in Human Dermal Regions due to Tumors

    Directory of Open Access Journals (Sweden)

    K. R. pardasani

    2005-01-01

    Full Text Available In this study, a two dimensional infinite element model has been developed to study thermal effect in human dermal regions due to tumors. This model incorporates the effect of blood mass flow rate, metabolic heat generation and thermal conductivity of the tissues.The dermal region is divided into three natural layers, namely, epidermis, dermis and subdermal tissues. A uniformly perfused tumor is assumed to be present in the dermis. The domain is assumed to be finite along the depth and infinite along the breadth. The whole dermis region involving tumor is modelled with the help of triangular finite elements to incorporate the geometry of the region. These elements are surrounded by infinite domain elements along the breadth. Appropriate boundary conditions has been incorporated. A computer program has been developed to obtain the numerical results.

  9. Characteristics of prosthetic joint infections due to Enterococcus sp. and predictors of failure: a multi-national study.

    Science.gov (United States)

    Tornero, E; Senneville, E; Euba, G; Petersdorf, S; Rodriguez-Pardo, D; Lakatos, B; Ferrari, M C; Pilares, M; Bahamonde, A; Trebse, R; Benito, N; Sorli, L; del Toro, M D; Baraiaetxaburu, J M; Ramos, A; Riera, M; Jover-Sáenz, A; Palomino, J; Ariza, J; Soriano, A

    2014-11-01

    The objective of this study was to review the characteristics and outcome of prosthetic joint infections (PJI) due to Enterococcus sp. collected in 18 hospitals from six European countries. Patients with a PJI due to Enterococcus sp. diagnosed between January 1999 and July 2012 were retrospectively reviewed. Relevant information about demographics, comorbidity, clinical characteristics, microbiological data, surgical treatment and outcome was registered. Univariable and multivariable analyses were performed. A total of 203 patients met the inclusion criteria. The mean (SD) was 70.4 (13.6) years. In 59 patients the infection was diagnosed within the first 30 days (29.1%) from arthroplasty, in 44 (21.7%) between 31 and 90 days, in 54 (26.6%) between 91 days and 2 years and in 43 (21%) after 2 years. Enterococcus faecalis was isolated in 176 cases (89%). In 107 (54%) patients the infection was polymicrobial. Any comorbidity (OR 2.53, 95% CI 1.18-5.40, p 0.01), and fever (OR 2.65, 95% CI 1.23-5.69, p 0.01) were independently associated with failure. The only factor associated with remission was infections diagnosed later than 2 years (OR 0.25, 95% CI 0.09-0.71, p 0.009). In conclusion, prosthetic joint infections due to Enterococcus sp. were diagnosed within the first 2 years from arthroplasty in >70% of the patients, almost 50% had at least one comorbidity and infections were frequently polymicrobial (54%). The global failure rate was 44% and patients with comorbidities, fever, and diagnosed within the first 2 years from arthroplasty had a poor prognosis.

  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. Parametric study of the potential for BWR ECCS strainer blockage due to LOCA generated debris. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zigler, G.; Brideau, J.; Rao, D.V.; Shaffer, C.; Souto, F.; Thomas, W. [Science and Engineering Associates, Inc., Albuquerque, NM (United States)

    1995-10-01

    This report documents a plant-specific study for a BWR/4 with a Mark I containment that evaluated the potential for LOCA generated debris and the probability of losing long term recirculation capability due ECCS pump suction strainer blockage. The major elements of this study were: (1) acquisition of detailed piping layouts and installed insulation details for a reference BWR; (2) analysis of plant specific piping weld failure probabilities to estimate the LOCA frequency; (3) development of an insulation and other debris generation and drywell transport models for the reference BWR; (4) modeling of debris transport in the suppression pool; (5) development of strainer blockage head loss models for estimating loss of NPSH margin; (6) estimation of core damage frequency attributable to loss of ECCS recirculation capability following a LOCA. Elements 2 through 5 were combined into a computer code, BLOCKAGE 2.3. A point estimate of overall DEGB pipe break frequency (per Rx-year) of 1.59E-04 was calculated for the reference plant, with a corresponding overall ECCS loss of NPSH frequency (per Rx-year) of 1.58E-04. The calculated point estimate of core damage frequency (per Rx-year) due to blockage related accident sequences for the reference BWR ranged from 4.2E-06 to 2.5E-05. The results of this study show that unacceptable strainer blockage and loss of NPSH margin can occur within the first few minutes after ECCS pumps achieve maximum flows when the ECCS strainers are exposed to LOCA generated fibrous debris in the presence of particulates (sludge, paint chips, concrete dust). Generic or unconditional extrapolation of these reference plant calculated results should not be undertaken.

  12. Human health and pollution due to solid waste incinetators (SWI: a selection of two recent well conducted studies

    Directory of Open Access Journals (Sweden)

    V. Gennaro

    2011-01-01

    Full Text Available Incinerators reduce the volume of visible waste, turning it into ashes and smoke which can cause local and global environmental pollution due to particulate matter (PM, dioxins, furans, hydrochloric acid, hydrocarbons, heavy metals, sulfur and nitrogen dioxides. In order to describe cancers and non-neoplastic diseases in populations exposed to incinerator pollution, the scientific literature available since 1987 has been selected on the basis of the best epidemiological evidences. In Italy, women who lived for at least 5 years in areas that were likely to be the most polluted by heavy metals, showed increased risk of death from all causes (relative risk, RR=1.17-1.54. In France, an incidence study found increases in all cancer risks both in males (RR=1.06 who resided in areas where dioxin pollution was estimated to be higher than it was in the referent areas (less dioxin polluted.

  13. In-vitro Study on Temperature Changes in the Pulp Chamber Due to Thermo-Cure Glass Ionomer Cements

    Science.gov (United States)

    van Duinen, Raimond NB; Shahid, Saroash; Hill, Robert

    2016-01-01

    The application of the Glass Ionomer Cements in clinical dentistry is recommended due to properties such as fluoride release, chemical adhesion to tooth, negligible setting shrinkage, and coefficient of thermal expansion close to tooth, low creep, and good color stability. However, the cement is vulnerable to early exposure to moisture due to slow setting characteristics. The uses of external energy such as ultrasound and radiant heat (Thermo-curing) have been reported to provide acceleration of the setting chemistry and enhance physical properties. Aim: The aim of this in vitro study was to analyze temperature changes in the pulpal chamber when using radiant heat to accelerate the setting of GICs. Material and Methods:The encapsulated GIC Equia Forte was used for this study. The temperature changes in the pulp were measured using thermocouple in the cavities which were 2,6 and 4,7mm deep with and without filling. Results:The results showed that a temperature rise (ΔT) in the pulp chamber was 3,7°C. ΔT for the 2.6mm and 4.7mm deep cavity and without placing any restoration the temperature was 4,2°C and 2,6°C respective