oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Supporting information for: New methods for analyzing serological data with applications to influenza surveillance  [PDF]
Wilfred Ndifon
Quantitative Biology , 2011, DOI: 10.1111/j.1750-2659.2010.00192.x
Abstract: For decades, the hemagglutination-inhibition (HI) assay has been used in epidemiological and basic biological studies of influenza viruses. The mechanistic basis of the assay results (called titers) is not well understood. The first part of this document describes a biophysical model of HI that illuminates the mechanistic basis of and provides the theoretical motivation for new ways of interpreting titers. The biophysical model is applicable to other serological assays; this fact is illustrated using the neutralization assay. The second part of the document describes some new ways of interpreting titers, which involve, among other methods, singular value decomposition and probabilistic multidimensional scaling. The third part of the document discusses biological and mathematical issues related to the determination of the effective dimensionality of titers, and describes an algorithm for recovering unavailable titers.
Serological Response to the 2009 Pandemic Influenza A (H1N1) Virus for Disease Diagnosis and Estimating the Infection Rate in Thai Population  [PDF]
Hatairat Lerdsamran,Chakrarat Pittayawonganon,Phisanu Pooruk,Anek Mungaomklang,Sopon Iamsirithaworn,Prasert Thongcharoen,Uraiwan Kositanont,Prasert Auewarakul,Kulkanya Chokephaibulkit,Sineenat Oota,Warin Pongkankham,Patummal Silaporn,Supaloek Komolsiri,Pirom Noisumdaeng,Tawee Chotpitayasunondh,Chariya Sangsajja,Witthawat Wiriyarat,Suda Louisirirotchanakul,Pilaipan Puthavathana
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0016164
Abstract: Individuals infected with the 2009 pandemic virus A(H1N1) developed serological response which can be measured by hemagglutination-inhibition (HI) and microneutralization (microNT) assays.
Comparative investigations of sensitivity and specificity of immunoenzyme probe and inhibition hemagglutination test in serological diagnostics of newcastle disease in poultry  [PDF]
Mili? Nenad,Ni?avi? Jakov,Radoji?i? Marina,?ekler Marina
Veterinarski Glasnik , 2009, DOI: 10.2298/vetgl0902037m
Abstract: Comparative investigations of the sensitivity and specificity of the indirect immunoenzyme probe - iELISA and the hemagglutination inhibition test (HI test) in serological diagnostics of the Newcastle disease in poultry were carried out using samples of blood serum taken from non-vaccinated and vaccinated poultry. A total of 14 samples of blood serum from non-vaccinated poultry were examined using the immunoenzyme probe - iELISA, and nine of these were found to be positive to the presence of specific antigen against the Newcastle disease virus, while two samples were suspect, and no presence of specific antibodies was established in three samples. Examinations of 82 samples of blood serum from vaccinated poultry for the presence of specific antibodies against the Newcastle disease virus established their presence in 80 serum samples, while one sample was suspect and one sample was negative. The values of the titer of specific antibodies in blood serum samples of vaccinated and non-vaccinated poultry established using the hemagglutination inhibition test (HI test) ranged from 1:2 to 1:32.
Comparison of a Recombinant-antigen Enzyme Immunoassay with Treponema pallidum Hemagglutination Test for Serological Confirmation of Syphilis
Rodríguez, Islay;álvarez, Elvio L;Fernández, Carmen;Miranda, Alina;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000300012
Abstract: a recombinant-antigen enzyme immunoassay (eia), bioscreentm anti-treponema pallidum, was compared favorably with the t. pallidum hemagglutination test, in the detection of specific antibodies in different groups of sera from patients with primary (n = 38), secondary (n = 10), early latent (n = 28) and congenital syphilis (n = 2), patients with leptospirosis ( n= 8), infectious mononucleosis (n = 7), hepatitis (n = 9), diabetes mellitus (n = 11), rheumatoid arthritis (n = 13), leprosy (n = 11), tuberculosis (n = 9), hiv/aids ( n= 12), systemic lupus erythematosus (n = 4), rheumatic fever (n = 3), old-persons (n = 9), pregnant women (n = 29) and blood donors (n = 164). the coincidence between them was 95.1%. the sensitivity and specificity of the eia were 93.3% and 95.5%, respectively. fifteen serum specimens belonging to old-persons, pregnant women, blood donors, and patients with human leptospirosis, hepatitis, diabetes mellitus, tuberculosis and rheumatic fever gave false-positive results by venereal disease research laboratory and/or rapid plasma reagin. the eia can be used as alternative method for the serological confirmation of syphilis.
Comparison of a Recombinant-antigen Enzyme Immunoassay with Treponema pallidum Hemagglutination Test for Serological Confirmation of Syphilis  [cached]
Rodríguez Islay,álvarez Elvio L,Fernández Carmen,Miranda Alina
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: A recombinant-antigen enzyme immunoassay (EIA), BioSCREEN TM anti-Treponema pallidum, was compared favorably with the T. pallidum hemagglutination test, in the detection of specific antibodies in different groups of sera from patients with primary (n = 38), secondary (n = 10), early latent (n = 28) and congenital syphilis (n = 2), patients with leptospirosis ( n= 8), infectious mononucleosis (n = 7), hepatitis (n = 9), diabetes mellitus (n = 11), rheumatoid arthritis (n = 13), leprosy (n = 11), tuberculosis (n = 9), HIV/Aids ( n= 12), systemic lupus erythematosus (n = 4), rheumatic fever (n = 3), old-persons (n = 9), pregnant women (n = 29) and blood donors (n = 164). The coincidence between them was 95.1%. The sensitivity and specificity of the EIA were 93.3% and 95.5%, respectively. Fifteen serum specimens belonging to old-persons, pregnant women, blood donors, and patients with human leptospirosis, hepatitis, diabetes mellitus, tuberculosis and rheumatic fever gave false-positive results by Venereal Disease Research Laboratory and/or Rapid Plasma Reagin. The EIA can be used as alternative method for the serological confirmation of syphilis.
International Network for Comparison of HIV Neutralization Assays: The NeutNet Report  [PDF]
Eva Maria Feny?, Alan Heath, Stefania Dispinseri, Harvey Holmes, Paolo Lusso, Susan Zolla-Pazner, Helen Donners, Leo Heyndrickx, Jose Alcami, Vera Bongertz, Christian Jassoy, Mauro Malnati, David Montefiori, Christiane Moog, Lynn Morris, Saladin Osmanov, Victoria Polonis, Quentin Sattentau, Hanneke Schuitemaker, Ruengpung Sutthent, Terri Wrin, Gabriella Scarlatti
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0004505
Abstract: Background Neutralizing antibody assessments play a central role in human immunodeficiency virus type-1 (HIV-1) vaccine development but it is unclear which assay, or combination of assays, will provide reliable measures of correlates of protection. To address this, an international collaboration (NeutNet) involving 18 independent participants was organized to compare different assays. Methods Each laboratory evaluated four neutralizing reagents (TriMab, 447-52D, 4E10, sCD4) at a given range of concentrations against a panel of 11 viruses representing a wide range of genetic subtypes and phenotypes. A total of 16 different assays were compared. The assays utilized either uncloned virus produced in peripheral blood mononuclear cells (PBMCs) (virus infectivity assays, VI assays), or their Env-pseudotyped (gp160) derivatives produced in 293T cells (PSV assays) from molecular clones or uncloned virus. Target cells included PBMC and genetically-engineered cell lines in either a single- or multiple-cycle infection format. Infection was quantified by using a range of assay read-outs that included extracellular or intracellular p24 antigen detection, RNA quantification and luciferase and beta-galactosidase reporter gene expression. Findings PSV assays were generally more sensitive than VI assays, but there were important differences according to the virus and inhibitor used. For example, for TriMab, the mean IC50 was always lower in PSV than in VI assays. However, with 4E10 or sCD4 some viruses were neutralized with a lower IC50 in VI assays than in the PSV assays. Inter-laboratory concordance was slightly better for PSV than for VI assays with some viruses, but for other viruses agreement between laboratories was limited and depended on both the virus and the neutralizing reagent. Conclusions The NeutNet project demonstrated clear differences in assay sensitivity that were dependent on both the neutralizing reagent and the virus. No single assay was capable of detecting the entire spectrum of neutralizing activities. Since it is not known which in vitro assay correlates with in vivo protection, a range of neutralization assays is recommended for vaccine evaluation.
Individual serological follow-up of patients with suspected or confirmed abdominal angiostrongyliasis
Palominos, Penélope E;Gasnier, Rose;Rodriguez, Rubens;Agostini, Aventino A;Graeff-Teixeira, Carlos;
Memórias do Instituto Oswaldo Cruz , 2008, DOI: 10.1590/S0074-02762008005000002
Abstract: abdominal angiostrongyliasis (aa) is a zoonotic nematode infection caused by angiostrongylus costaricensis, with widespread occurrence in the americas. although the human infection may be highly prevalent, morbidity is low in southern brazil. confirmed diagnosis is based on finding parasitic structures in pathological examination of biopsies or surgical resections. serology stands as an important diagnostic tool in the less severe courses of the infection. our objective is to describe the follow up of humoral reactivity every 2-4 weeks up to one year, in six individuals with confirmed (c) and ten suspected (s) aa. antibody (igg) detection was performed by elisa and resulted in gradually declining curves of reactivity in nine subjects (56%) (4c + 5s), that were consistently negative in only three of them (2c + 1s) after 221, 121 and 298 days. three individuals (2c + 1s) presented with low persistent reacitivity, other two (1c + 1s) were serologically negative from the beginning, but also presenting a declining tendency. the study shows indications that abdominal angiostrongyliasis is usually not a persistent infection: although serological negativation may take many months, igg reactivity is usually declining along time and serum samples pairing may add valuable information to the diagnostic workout.
Low Rate of Pandemic A/H1N1 2009 Influenza Infection and Lack of Severe Complication of Vaccination in Pregnant Women: A Prospective Cohort Study  [PDF]
Odile Launay, Anne Krivine, Caroline Charlier, Van Truster, Vassilis Tsatsaris, Jacques Lepercq, Yves Ville, Carolyn Avenell, Thibaut Andrieu, Flore Rozenberg, Florence Artiguebielle, Jean-Marc Tréluyer, Fran?ois Goffinet, Inserm COFLUPREG Study Group
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0052303
Abstract: Background In 2009, pregnant women were specifically targeted by a national vaccination campaign against pandemic A/H1N1 influenza virus. The objectives of the COFLUPREG study, initially set up to assess the incidence of serious forms of A/H1N1 influenza, were to assess the consequences of maternal vaccination on pregnancy outcomes and maternal seroprotection at delivery. Methods Pregnant women, between 12 and 35 weeks of gestation, non vaccinated against A/H1N1 2009 influenza were randomly selected to be included in a prospective cohort study conducted in three maternity centers in Paris (France) during pandemic period. Blood samples were planned to assess hemagglutination inhibition (HI) antibody against A/H1N1 2009 influenza at inclusion and at delivery. Results Among the 877 pregnant women included in the study, 678 (77.3%) had serum samples both at inclusion and delivery, and 320 (36.5%) received pandemic A/H1N1 2009 influenza vaccine with a median interval between vaccination and delivery of 92 days (95% CI 48–134). At delivery, the proportion of women with seroprotection (HI antibodies titers against A/H1N1 2009 influenza of 1:40 or greater) was 69.9% in vaccinated women. Of the 422 non-vaccinated women with serological data, 11 (2.6%; 95%CI: 1.3–4.6) had laboratory documented A/H1N1 2009 influenza (1 with positive PCR and 10 with serological seroconversion). None of the 877 study’s women was hospitalized for flu. No difference on pregnancy outcomes was evidenced between vaccinated women, non-vaccinated women without seroconversion and non-vaccinated women with flu. Conclusion Despite low vaccine coverage, incidence of pandemic flu was low in this cohort of pregnant women.No effect on pregnancy and delivery outcomes was evidenced after vaccination.
Antibody response of healthy children to pandemic A/H1N1/2009 influenza virus
Susanna Esposito, Cristina Daleno, Claudia Tagliabue, Alessia Scala, Irene Picciolli, Francesca Taroni, Carlotta Galeone, Fausto Baldanti, Nicola Principi
Virology Journal , 2011, DOI: 10.1186/1743-422x-8-563
Abstract: Demographic, clinical and virologic data were collected from 69 otherwise healthy children with pandemic A/H1N1/2009 influenza (27 females, mean age ± SD: 5.01 ± 4.55 years). Their antibody levels against pandemic A/H1N1/2009 and seasonal A/H1N1 influenza viruses were evaluated by measuring hemagglutination-inhibiting antibodies using standard assays. Sixty-four patients (92.8%) with pandemic A/H1N1/2009 influenza had A/H1N1/2009 antibody levels of ≥40, whereas only 28/69 (40.6%) were seroprotected against seasonal A/H1N1 influenza virus. Those who were seroprotected against seasonal A/H1N1 virus were significantly older, significantly more often hospitalised, had a diagnosis of pneumonia significantly more frequently, and were significantly more often treated with oseltamivir than those who were not seroprotected (p < 0.05). The children with the most severe disease (assessed on the basis of a need for hospitalisation and a diagnosis of pneumonia) had the highest antibody response against pandemic A/H1N1/2009 influenza virus.Otherwise healthy children seem to show seroprotective antibody titres after natural infection with pandemic A/H1N1/2009 influenza virus. The strength of the immune response seems to be related to the severity of the disease, but not to previous seasonal A/H1N1 influenza immunity.An A/H1N1 quadruple reassortant influenza virus (A/H1N1/2009) of swine origin has recently arisen from a subtype A/H1N1 influenza virus that was already endemic in humans. It caused a pandemic [1], with a very high disease burden among children and young adults: up to 50% showed signs of infection, against 10% of the adult population [2,3]. Severe disease and hospitalisations were also associated with younger age groups [4,5].Serological analyses of pre-pandemic serum samples showed that a number of adult and elderly subjects had higher levels of cross-reactive A/H1N1/2009 antibodies than young adults and children (the older the patient, the higher the levels) [2,6,7].
Serological evidences showing the involvement of free-living pheasants in the influenza ecology
Maria Alessandra De Marco,Laura Campitelli,Mauro Delogu,Elisabetta Raffini
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2005.287
Abstract: From 1995 to 2002, 219 sera were collected in Northern Italy from wild pheasants, in order to establish the possible involvement of these Galliformes birds in the influenza ecology. A serological survey for avian influenza viruses (AIVs) was carried out by ELISA test in order to detect type A influenza antibodies. The overall seroprevalence was 12.3%, with yearly values ranging from 0% to 42.5%. No antibodies against either H5 or H7 AIV subtypes were found by hemagglutination-inhibition test. Data from 16 recaptured birds, among 113 animals banded for individual identification, showed seroconversions in 2 pheasants. Our results indicate AIV circulation in free-living pheasants; the involvement of this land-based bird species in influenza ecology is discussed.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.