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Sample records for surface antigens termed

  1. Monoclonal antibodies against rat leukocyte surface antigens

    NARCIS (Netherlands)

    van den Berg, T. K.; Puklavec, M. J.; Barclay, A. N.; Dijkstra, C. D.

    2001-01-01

    Monoclonal antibodies have proven to be powerful tools for studying the properties of leukocyte surface antigens and the cells that express them. In the past decades many monoclonal antibodies (mAb) for identifying the different rat leukocyte surface antigens have been described. A list of mAb is

  2. Long-term effect of interferon plus ribavirin on hepatitis B surface antigen seroclearance in patients dually infected with hepatitis B and C viruses.

    Directory of Open Access Journals (Sweden)

    Ming-Lun Yeh

    Full Text Available BACKGROUND: Interferon-α/ribavirin combination therapy might promote hepatitis B surface antigen (HBsAg seroclearance in patients dually infected with hepatitis B and C viruses (HBV/HCV, but the long-term effect remains unclear. We aimed to investigate the rate of and the factors associated with HBsAg seroclearance during long-term follow-up after interferon-α/ribavirin combination therapy in HBV/HCV dually-infected patients. METHODOLOGY/PRINCIPAL FINDINGS: Eighty-one patients who received interferon-α/ribavirin combination therapy for 24 weeks with a follow-up period of >24 weeks were enrolled. HBV serological markers and HBV DNA were determined every 6 months. Early and late HBsAg seroclearance were defined as HBsAg loss in less or more than 6 months after end-of-treatment, respectively. Fifteen (18.5% patients had HBsAg seroclearance during a mean follow-up period of 3.4 (0.5-5.1 years. The 5-year cumulative incidence was 25.6%. Baseline cirrhosis and HBV DNA negativity 1 year after end-of-treatment were independently predictive of HBsAg seroclearance with an odds ratio (OR, 95% confidence intervals (CI of 16.6, 1.8-153 and 9.2, 1.4-62.1, respectively, by Cox regression hazard analysis. Four patients developed early and 11 developed late HBsAg seroclearance, respectively. Cox regression hazard analysis showed no factor was associated with early HBsAg seroclearance, whilst HBV DNA negativity 1 year after end-of-treatment was the only significant factor predicting late HBsAg loss (OR, 43.0; CI, 2.5-745. Five patients had HBsAg seroconversion with a 5-year cumulative incidence of 8.3%. HBV DNA negativity at baseline and one year after EOT had a trend for HBsAg seroconversion. HCV response did not correlate to HBsAg loss. CONCLUSIONS: We demonstrated that interferon-α/ribavirin had long-term effect on HBsAg seroclearance in dually HBV/HCV-infected patients. Baseline cirrhosis and seroclearance of HBV DNA 1 year after end-of-treatment were

  3. Analysis of cell surface antigens by Surface Plasmon Resonance imaging

    NARCIS (Netherlands)

    Stojanovic, Ivan; Schasfoort, Richardus B.M.; Terstappen, Leonardus Wendelinus Mathias Marie

    2013-01-01

    Surface Plasmon Resonance (SPR) is most commonly used to measure bio-molecular interactions. SPR is used significantly less frequent for measuring whole cell interactions. Here we introduce a method to measure whole cells label free using the specific binding of cell surface antigens expressed on

  4. 21 CFR 660.40 - Hepatitis B Surface Antigen.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

  5. Long-term real-world entecavir therapy in treatment-naïve hepatitis B patients: base-line hepatitis B virus DNA and hepatitis B surface antigen levels predict virologic response.

    Science.gov (United States)

    Cho, Ju-Yeon; Sohn, Won; Sinn, Dong-Hyun; Gwak, Geum-Youn; Paik, Yong-Han; Choi, Moon Seok; Koh, Kwang Cheol; Paik, Seung Woon; Yoo, Byung Chul; Lee, Joon Hyeok

    2017-07-01

    Entecavir is a potent nucleoside analogue with high efficacy and barrier for resistance. We aimed to investigate the long-term efficacy and viral resistance rate of entecavir and explore the factors associated with virologic response, including quantitative hepatitis B surface antigen (qHBsAg) levels. One thousand and nine treatment-naïve chronic hepatitis B (CHB) patients were evaluated for cumulative rates of virologic response, biochemical response, and entecavir mutations. The role of baseline qHBsAg for virologic response was assessed in 271 patients with qHBsAg prior to entecavir treatment. The median duration of entecavir treatment was 26.5 months. The cumulative rate of virologic response at years 1, 3, and 5 were 79.0%, 95.6%, and 99.4%, respectively. The cumulative rate of entecavir resistance was 1.0% and 2.1% in years 3 and 5. Multivariate analysis identified baseline hepatitis B e antigen (HBeAg) negative status ( p response. Lower qHBsAg was an independent predictor of virologic response in patients with baseline qHBsAg. There were no serious adverse events during treatment. Long-term entecavir treatment of nucleos(t)ide-naïve CHB patients was associated with an excellent virologic response and a low rate of entecavir-resistant mutations at 5 years. Baseline HBV DNA load, qHBsAg levels, and HBeAg status were predictors of virologic response during entecavir treatment.

  6. Identification of Surface Exposed Elementary Body Antigens of ...

    African Journals Online (AJOL)

    This study sought to identify the surface exposed antigenic components of Cowdria ruminantium elementary body (EB) by biotin labeling, determine effect of reducing and non-reducing conditions and heat on the mobility of these antigens and their reactivity to antibodies from immunized animals by Western blotting.

  7. Seroprevalence of hepatitis B surface antigen among pregnant ...

    African Journals Online (AJOL)

    Seroprevalence of hepatitis B surface antigen among pregnant women attending the Hospital for Women & Children in Koutiala, Mali. Brett MacLean, Rosanna F Hess, Edward Bonvillain, Joseph Kamate, Daoda Dao, Amy Cosimano, Shannon Hoy ...

  8. 21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product is...

  9. Prevalence of Hepatitis B Surface Antigen among Women of ...

    African Journals Online (AJOL)

    This study documents the seroprevalence of hepatitis B surface antigen (HBs Ag) among women of childbearing age attending various family clinics in Lagos, Nigeria. A total of 501 women were screened with Wellcozyme ELISA technique, of which 45(8.9%) were seropositive. Women in occupations related to needle work ...

  10. Monoclonal Antibody Production against Human Spermatozoal Surface Antigens

    Directory of Open Access Journals (Sweden)

    M Jedi-Tehrani

    2005-10-01

    Full Text Available Introduction: As monoclonal antibodies are potential tools for characterization of soluble or cellular surface antigens, use of these proteins has always been considered in infertility and reproduction research. Therefore, in this study, monoclonal antibodies against human sperm surface antigens were produced. Material and Methods: To produce specific clones against human sperm surface antigens, proteins were extracted using solubilization methods. Balb/c mice were immunized intraperitoneally with the proteins using complete Freund’s adjuvant in the first injection and incomplete Adjuvant in the following booster injections. Hybridoma cells producing ASA were cloned by limiting dilution. Results: Five stable ASA producing hybridoma clones were achieved and their antibody isotypes were determined by ELISA. All the isotypes were of IgG class. Their cross reactivity with rat and mice spermatozoa was examined but they did not have any cross reactivity. Conclusion: The produced antibodies can be used in further studies to characterize and evaluate each of the antigens present on human sperm surface and determining their role in fertilization.

  11. Prevalence of hepatitis B surface antigen seropositivity among HIV ...

    African Journals Online (AJOL)

    Hepatitis B surface antigen (HBsAg) was tested for using a one step lateral flow rapid chromatographic immunoassay (Acumen labs and diagnostic centre, Bangalore, India) and HIV 1/2 was tested using two kits, Determine (made by Abbot, Japan for Inverness Medical, Japan). Results: A total of 2018 subjects were studied ...

  12. Prevalence of hepatitis b virus surface antigens (HBsag) and ...

    African Journals Online (AJOL)

    The prevalences of hepatitis B virus surface antigen (HBsAg) and hepatitis C virus (HCV) antibodies were determined in 560 blood donors sera using ELISA kits (DIALAB., Austria). Forty eight (8.57%) of these were positive for hepatitis B virus infection, while 33(5.89%) were positive to hepatitis C virus antibodies. The sex ...

  13. Hepatitis B surface antigen incorporated in dissolvable microneedle array patch is antigenic and thermostable.

    Science.gov (United States)

    Poirier, Danielle; Renaud, Frédéric; Dewar, Vincent; Strodiot, Laurent; Wauters, Florence; Janimak, Jim; Shimada, Toshio; Nomura, Tatsuya; Kabata, Koki; Kuruma, Koji; Kusano, Takayuki; Sakai, Masaki; Nagasaki, Hideo; Oyamada, Takayoshi

    2017-11-01

    Alternatives to syringe-based administration are considered for vaccines. Intradermal vaccination with dissolvable microneedle arrays (MNA) appears promising in this respect, as an easy-to-use and painless method. In this work, we have developed an MNA patch (MNAP) made of hydroxyethyl starch (HES) and chondroitin sulphate (CS). In swines, hepatitis B surface antigen (HBsAg) formulated with the saponin QS-21 as adjuvant, both incorporated in HES-based MNAP, demonstrated the same level of immunogenicity as a commercially available aluminum-adjuvanted HBsAg vaccine, after two immunizations 28 days apart. MNAP application was associated with transient skin reactions (erythema, lump, scab), particularly evident when the antigen was delivered with the adjuvant. The thermostability of the adjuvanted antigen when incorporated in the HES-based matrix was also assessed by storing MNAP at 37, 45 or 50 °C for up to 6 months. We could demonstrate that antigenicity was retained at 37 and 45 °C and only a 10% loss was observed after 6 months at 50 °C. Our results are supportive of MNAP as an attractive alternative to classical syringe-based vaccination. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Cellular Cancer Vaccines: an Update on the Development of Vaccines Generated from Cell Surface Antigens

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    Petr G. Lokhov, Elena E. Balashova

    2010-01-01

    Full Text Available A recent advance in anti-cancer therapies has been the use of cancer cells to develop vaccines. However, immunization with cancer cell-based vaccines has not resulted in significant long-term therapeutic benefits. A possible reason for this is that while cancer cells provide surface antigens that are targets for a desired immune response, they also contain a high abundance of housekeeping proteins, carbohydrates, nucleic acids, lipids, and other intracellular contents that are ubiquitous in all mammalian cells. These ubiquitous molecules are not the intended targets of this therapy approach, and thus, the immune response generated is not sufficient to eliminate the cancer cells present. In this review, a discussion of the cell surface of cancer cells is presented in relation to the goals of improving antigen composition of cancer cell-based vaccines. Strategies to enrich vaccines for cancer-specific antigens are also discussed.

  15. CARbodies: Human Antibodies Against Cell Surface Tumor Antigens Selected From Repertoires Displayed on T Cell Chimeric Antigen Receptors

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    Vanesa Alonso-Camino

    2013-01-01

    Full Text Available A human single-chain variable fragment (scFv antibody library was expressed on the surface of human T cells after transduction with lentiviral vectors (LVs. The repertoire was fused to a first-generation T cell receptor ζ (TCRζ-based chimeric antigen receptor (CAR. We used this library to isolate antibodies termed CARbodies that recognize antigens expressed on the tumor cell surface in a proof-of-principle system. After three rounds of activation-selection there was a clear repertoire restriction, with the emergence dominant clones. The CARbodies were purified from bacterial cultures as soluble and active proteins. Furthermore, to validate its potential application for adoptive cell therapy, human T cells were transduced with a LV encoding a second-generation costimulatory CAR (CARv2 bearing the selected CARbodies. Transduced human primary T cells expressed significant levels of the CARbodies-based CARv2 fusion protein on the cell surface, and importantly could be specifically activated, after stimulation with tumor cells. This approach is a promising tool for the generation of antibodies fully adapted to the display format (CAR and the selection context (cell synapse, which could extend the scope of current adoptive cell therapy strategies with CAR-redirected T cells.

  16. Paired Expression Analysis of Tumor Cell Surface Antigens

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    Rimas J. Orentas

    2017-08-01

    Full Text Available Adoptive immunotherapy with antibody-based therapy or with T cells transduced to express chimeric antigen receptors (CARs is useful to the extent that the cell surface membrane protein being targeted is not expressed on normal tissues. The most successful CAR-based (anti-CD19 or antibody-based therapy (anti-CD20 in hematologic malignancies has the side effect of eliminating the normal B cell compartment. Targeting solid tumors may not provide a similar expendable marker. Beyond antibody to Her2/NEU and EGFR, very few antibody-based and no CAR-based therapies have seen broad clinical application for solid tumors. To expand the way in which the surfaceome of solid tumors can be analyzed, we created an algorithm that defines the pairwise relative overexpression of surface antigens. This enables the development of specific immunotherapies that require the expression of two discrete antigens on the surface of the tumor target. This dyad analysis was facilitated by employing the Hotelling’s T-squared test (Hotelling–Lawley multivariate analysis of variance for two independent variables in comparison to a third constant entity (i.e., gene expression levels in normal tissues. We also present a unique consensus scoring mechanism for identifying transcripts that encode cell surface proteins. The unique application of our bioinformatics processing pipeline and statistical tools allowed us to compare the expression of two membrane protein targets as a pair, and to propose a new strategy based on implementing immunotherapies that require both antigens to be expressed on the tumor cell surface to trigger therapeutic effector mechanisms. Specifically, we found that, for MYCN amplified neuroblastoma, pairwise expression of ACVR2B or anaplastic lymphoma kinase (ALK with GFRA3, GFRA2, Cadherin 24, or with one another provided the strongest hits. For MYCN, non-amplified stage 4 neuroblastoma, neurotrophic tyrosine kinase 1, or ALK paired with GFRA2, GFRA3, SSK

  17. Genetic variation and significance of hepatitis B surface antigen

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    ZHANG Zhenhua

    2013-11-01

    Full Text Available Hepatitis B virus (HBV is prone to genetic variation because there is reverse transcription in the process of HBV replication. The gene mutation of hepatitis B surface antigen may affect clinical diagnosis of HBV infection, viral replication, and vaccine effect. The current research and existing problems are discussed from the following aspects: the mechanism and biological and clinical significance of S gene mutation. Most previous studies focused on S gene alone, so S gene should be considered as part of HBV DNA in the future research on S gene mutation.

  18. Stable isotope labeling of oligosaccharide cell surface antigens

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Silks, L.A. III; Martinez, R.A. [and others

    1998-12-31

    The overall goal of this Laboratory Directed Research and Development (LDRD) project was to develop new methods for synthesis of {sup 13}C-labeled oligosaccharides that are required for nuclear magnetic resonance (NMR) studies of their solution conformation. Oligosaccharides are components of the cell`s outer surface and are involved in important processes such as cell-cell recognition and adhesion. Recently, Danishefsky and coworkers at Slone-Kettering Cancer Center developed a method for the solid-phase chemical synthesis of oligosaccharides. The specific goal of this LDRD project was to prepare uniform {sup 13}C-labeled aldohexose precursors required for the solid-phase synthesis of the Lewis blood-group antigenic determinants. We report the synthesis of {sup 13}C-labeled D-glucal, D-galactal and Fucosyl precursors. We have been collaborating with the Danishefsky group on the synthesis of the Lewis oligosaccharides and the NMR analysis of their solution conformation.

  19. Detection of Carcinoembryonic Antigens Using a Surface Plasmon Resonance Biosensor

    Science.gov (United States)

    Su, Fengyu; Xu, Chunye; Taya, Minoru; Murayama, Kimie; Shinohara, Yasuro; Nishimura, Shin-Ichiro

    2008-01-01

    Carcinoembryonic antigen (CEA) is an oncofoetal cell-surface glycoprotein that serves as an important tumor marker for colorectal and some other carcinomas. In this work, a CEA immunoassay using a surface plasmon resonance (SPR) biosensor has been developed. SPR could provide label-free, real-time detection with high sensitivity, though its ability to detect CEA in human serum was highly dependent on the analytical conditions employed. We investigated the influences of various analytical conditions including immobilization methods for anti-CEA antibody and composition of sensor surface on the selective and sensitive detection of CEA. The results show that anti-CEA antibody immobilized via Protein A or Protein G caused a large increase in the resonance signal upon injection of human serum due to the interactions with IgGs in serum, while direct covalent immobilization of anti-CEA antibody could substantially reduce it. An optimized protocol based on further kinetic analysis and the use of 2nd and 3rd antibodies for the sandwich assay allowed detecting spiked CEA in human serum as low as 25 ng/mL. Furthermore, a self-assembled monolayer of mixed ethylene-glycol terminated alkanethiols on gold was found to have a comparable ability in detecting CEA as CM5 with thick dextran matrix and C1 with short flat layer on gold. PMID:27879935

  20. Effect of hepatitis B immunisation in newborn infants of mothers positive for hepatitis B surface antigen

    DEFF Research Database (Denmark)

    Lee, Chuanfang; Gong, Yan; Brok, Jesper

    2006-01-01

    To evaluate the effects of hepatitis B vaccine and immunoglobulin in newborn infants of mothers positive for hepatitis B surface antigen.......To evaluate the effects of hepatitis B vaccine and immunoglobulin in newborn infants of mothers positive for hepatitis B surface antigen....

  1. Hepatitis B Virus DNA in Blood Samples Positive for Antibodies to Core Antigen and Negative for Surface Antigen

    Science.gov (United States)

    Gutiérrez, C.; León, G.; Loureiro, C. L.; Uzcátegui, N.; Liprandi, F.; Pujol, F. H.

    1999-01-01

    Anti-hepatitis B core antigen (HBcAg)-positive hepatitis B surface antigen (HBsAg)-negative plasma samples from blood donors were tested by nested PCR. DNA positivity was more significantly associated with high levels of anti-HBcAg than with low levels of anti-HBsAg antibodies. Analysis of a dilution of anti-HBcAg antibodies might result in a more rational exclusion of anti-HBcAg-positive HBsAg-negative samples, reducing the number of donations discarded and enabling more countries to incorporate anti-HBcAg testing. PMID:10473534

  2. Artificial neural network accurately predicts hepatitis B surface antigen seroclearance.

    Directory of Open Access Journals (Sweden)

    Ming-Hua Zheng

    Full Text Available BACKGROUND & AIMS: Hepatitis B surface antigen (HBsAg seroclearance and seroconversion are regarded as favorable outcomes of chronic hepatitis B (CHB. This study aimed to develop artificial neural networks (ANNs that could accurately predict HBsAg seroclearance or seroconversion on the basis of available serum variables. METHODS: Data from 203 untreated, HBeAg-negative CHB patients with spontaneous HBsAg seroclearance (63 with HBsAg seroconversion, and 203 age- and sex-matched HBeAg-negative controls were analyzed. ANNs and logistic regression models (LRMs were built and tested according to HBsAg seroclearance and seroconversion. Predictive accuracy was assessed with area under the receiver operating characteristic curve (AUROC. RESULTS: Serum quantitative HBsAg (qHBsAg and HBV DNA levels, qHBsAg and HBV DNA reduction were related to HBsAg seroclearance (P<0.001 and were used for ANN/LRM-HBsAg seroclearance building, whereas, qHBsAg reduction was not associated with ANN-HBsAg seroconversion (P = 0.197 and LRM-HBsAg seroconversion was solely based on qHBsAg (P = 0.01. For HBsAg seroclearance, AUROCs of ANN were 0.96, 0.93 and 0.95 for the training, testing and genotype B subgroups respectively. They were significantly higher than those of LRM, qHBsAg and HBV DNA (all P<0.05. Although the performance of ANN-HBsAg seroconversion (AUROC 0.757 was inferior to that for HBsAg seroclearance, it tended to be better than those of LRM, qHBsAg and HBV DNA. CONCLUSIONS: ANN identifies spontaneous HBsAg seroclearance in HBeAg-negative CHB patients with better accuracy, on the basis of easily available serum data. More useful predictors for HBsAg seroconversion are still needed to be explored in the future.

  3. Simultaneous detection of Hepatitis B surface antigen and its antibody by radioimmunoassay

    International Nuclear Information System (INIS)

    Crouzat-Reynes, Gerard; Perigois, Francois; Lecureuil, Michel; Lejeune, Bernard

    1981-01-01

    The authors describe an original radioimmunoassay which allows the simultaneous detection of hepatitis B surface antigen and its antibody in a biological sample. Antigen and antibody are indiscriminately detected in a first step and then distinguished in a second step using the same reagents [fr

  4. KIR content genotypes associate with carriage of hepatitis B surface antigen, e antigen and HBV viral load in Gambians.

    Directory of Open Access Journals (Sweden)

    Louis-Marie Yindom

    Full Text Available Hepatocellular carcinoma (HCC causes over 800,000 deaths worldwide annually, mainly in low income countries, and incidence is rising rapidly in the developed world with the spread of hepatitis B (HBV and C (HCV viruses. Natural Killer (NK cells protect against viral infections and tumours by killing abnormal cells recognised by Killer-cell Immunoglobulin-like Receptors (KIR. Thus genes and haplotypes encoding these receptors may be important in determining both outcome of initial hepatitis infection and subsequent chronic liver disease and tumour formation. HBV is highly prevalent in The Gambia and the commonest cause of liver disease. The Gambia Liver Cancer Study was a matched case-control study conducted between September 1997 and January 2001 where cases with liver disease were identified in three tertiary referral hospitals and matched with out-patient controls with no clinical evidence of liver disease.We typed 15 KIR genes using the polymerase chain reaction with sequence specific primers (PCR-SSP in 279 adult Gambians, 136 with liver disease (HCC or Cirrhosis and 143 matched controls. We investigated effects of KIR genotypes and haplotypes on HBV infection and associations with cirrhosis and HCC.Homozygosity for KIR group A gene-content haplotype was associated with HBsAg carriage (OR 3.7, 95% CI 1.4-10.0 whilst telomeric A genotype (t-AA was associated with reduced risk of e antigenaemia (OR 0.2, 95% CI 0.0-0.6 and lower viral loads (mean log viral load 5.2 vs. 6.9, pc = 0.022. One novel telomeric B genotype (t-ABx2 containing KIR3DS1 (which is rare in West Africa was also linked to e antigenaemia (OR 8.8, 95% CI 1.3-60.5. There were no associations with cirrhosis or HCC.Certain KIR profiles may promote clearance of hepatitis B surface antigen whilst others predispose to e antigen carriage and high viral load. Larger studies are necessary to quantify the effects of individual KIR genes, haplotypes and KIR/HLA combinations on long-term

  5. KIR content genotypes associate with carriage of hepatitis B surface antigen, e antigen and HBV viral load in Gambians.

    Science.gov (United States)

    Yindom, Louis-Marie; Mendy, Maimuna; Bodimeade, Christopher; Chambion, Caroline; Aka, Peter; Whittle, Hilton C; Rowland-Jones, Sarah L; Walton, Robert

    2017-01-01

    Hepatocellular carcinoma (HCC) causes over 800,000 deaths worldwide annually, mainly in low income countries, and incidence is rising rapidly in the developed world with the spread of hepatitis B (HBV) and C (HCV) viruses. Natural Killer (NK) cells protect against viral infections and tumours by killing abnormal cells recognised by Killer-cell Immunoglobulin-like Receptors (KIR). Thus genes and haplotypes encoding these receptors may be important in determining both outcome of initial hepatitis infection and subsequent chronic liver disease and tumour formation. HBV is highly prevalent in The Gambia and the commonest cause of liver disease. The Gambia Liver Cancer Study was a matched case-control study conducted between September 1997 and January 2001 where cases with liver disease were identified in three tertiary referral hospitals and matched with out-patient controls with no clinical evidence of liver disease. We typed 15 KIR genes using the polymerase chain reaction with sequence specific primers (PCR-SSP) in 279 adult Gambians, 136 with liver disease (HCC or Cirrhosis) and 143 matched controls. We investigated effects of KIR genotypes and haplotypes on HBV infection and associations with cirrhosis and HCC. Homozygosity for KIR group A gene-content haplotype was associated with HBsAg carriage (OR 3.7, 95% CI 1.4-10.0) whilst telomeric A genotype (t-AA) was associated with reduced risk of e antigenaemia (OR 0.2, 95% CI 0.0-0.6) and lower viral loads (mean log viral load 5.2 vs. 6.9, pc = 0.022). One novel telomeric B genotype (t-ABx2) containing KIR3DS1 (which is rare in West Africa) was also linked to e antigenaemia (OR 8.8, 95% CI 1.3-60.5). There were no associations with cirrhosis or HCC. Certain KIR profiles may promote clearance of hepatitis B surface antigen whilst others predispose to e antigen carriage and high viral load. Larger studies are necessary to quantify the effects of individual KIR genes, haplotypes and KIR/HLA combinations on long-term

  6. Identification and characterization of surface antigens in parasites, using radiolabelling techniques

    International Nuclear Information System (INIS)

    Ramasamy, R.

    1982-04-01

    Surface proteins of Schistosoma sp and Leishmania sp were studied using 125-Iodine as tracer. The surface proteins were labelled by the Lactoperoxidase method and the proteins then separated using SDS PAG electrophoresis and autoradiography. The possible immunogens were then separated using immunoprecipitation and Fluorescent Antibody techniques using sera from patients or from artificially immunized rabbits. Four common antigens were identified from the surfaces of male and female adult worms, cercariae and schistosomulae of S.mansoni. These antigens, which had molecular weights of 150,000, 78,000, 45,000, and 22,000 were also isolated from the surfaces of S.haematobium adults. The surface antigens on promastigotes of a Kenyan strain of Leishmania donovani were separated into three protein antigens with molecular weights of 66,000, 59,000 and 43,000 respectively. The 59,000 molecular weight antigen was a glycoprotein and was common to promastigotes of an American and Indian strain of L.donovani and to L.braziliensis mexicana. None of the isolated antigens have been shown to have a protective effect when vaccinated into mice, but the study illustrates the value of radionuclide tracers in the unravelling of the mosaic of antigens which parasites possess

  7. HMME-based PDT restores expression and function of transporter associated with antigen processing 1 (TAP1) and surface presentation of MHC class I antigen in human glioma.

    Science.gov (United States)

    Zhang, Shan-Yi; Li, Jun-Liang; Xu, Xin-Ke; Zheng, Mei-Guang; Wen, Cheng-Cai; Li, Fang-Cheng

    2011-11-01

    Numerous studies have established that photodynamic therapy (PDT) can trigger tumor-specific immunity and cancer cell immunogenicity, both of which play a critical role in the long-term control of oncogenesis; however, the underlying mechanisms are largely unexplained. Deficiency of the transporter associated with antigen processing 1 (TAP1) has been observed in a variety of tumors, and the question has been raised whether the restoration of TAP1 could facilitate the activation of antitumor immunity. To elucidate the mechanisms underlying PDT-induced immunopotentiation, we examined the hypothesis that upregulating TAP1 via PDT may contribute to enhancement of antitumor immunity and cancer cell immunogenicity. In this study, we investigated the effects of PDT on the expression and function of TAP1 in glioma cells. We found that HMME-based PDT restored TAP1 expression in a rapid and transient manner. Furthermore, the newly synthesized TAP1 protein was capable of potentiating the activity of transporting antigen peptides. As a result, restoration of the expression and function of TAP1 translated into augmenting the presentation of surface MHC class I molecules. Overall, our data indicate that PDT enables glioma cells to recover both the expression of functional TAP1 and the presentation of surface MHC class I antigens, which are processes that may enhance antitumor immunity after PDT. These findings may have implications for PDT and provide new insights into the mechanisms underlying PDT-induced immunopotentiation.

  8. Sero-prevalence of hepatitis B surface antigen among pregnant ...

    African Journals Online (AJOL)

    There were no significant differences between prevalence recorded and agegroups but these were significant associations between risk factors namely tribal marks/tattooing, types of marriages and prevalence of hepatitis infection. The prevalence of hepatitis B antigen among pregnant women suggests that vertical ...

  9. Immunochemical Investigations of Cell Surface Antigens of Anaerobic Bacteria.

    Science.gov (United States)

    1976-01-15

    has also been visulalized . With use of a radioactive anti’qen bindinq assay, antibody to this capsularpolysaccharide has been demonstrated in anti- sera...With many bacteria, serogrouning is based on cansular oolysaccharide antigens. Serogrouping has led to much valuable epidemiologic information

  10. Preservation of surface-dependent properties of viral antigens following immobilization on particulate ceramic delivery vehicles.

    Science.gov (United States)

    Kossovsky, N; Gelman, A; Sponsler, E; Rajguru, S; Torres, M; Mena, E; Ly, K; Festekjian, A

    1995-05-01

    B-cell stimulation for the purpose of evoking an effective neutralizing humoral immune response is a surface phenomenon that is exquisitely specific to antigen conformation. Consequently, successful delivery of antigen, such as would be desired in a vaccine, entails preservation of an antigen's apparent native surface (conformational) properties. Prior to testing the actual vaccinating efficacy of delivered antigens, the surface properties could be assessed through a variety of in vitro and in vivo assays in which the measurement standard would be the properties of the antigens in their native state (whole virus). Using surface modified nanocrystalline carbon and calcium-phosphate ceramic particulates (carbon ceramics and brushite), we evaluated the surface activity of immobilized non-nuclear material extracted from HIV-1. Physical characterization showed that the particles with immobilized antigen ("HIV decoys") measured 50 nm in diameter (HIV = 50-100 nm) and exhibited the same zeta potentials as whole (live) HIV. In vitro testing showed that the HIV decoys were recognized by both conformationally nonspecific and specific monoclonal antibodies, were recognized by human IgG from HIV antibody-positive patients, and could promote surface agglomeration among malignant T-cells similar to live HIV. Last, in vivo testing in three vaccinated animal species showed that the HIV decoys elicited humoral and cellular immune responses similar to that evoked by whole (live) HIV.

  11. Relation between laboratory test results and histological hepatitis activity in individuals positive for hepatitis B surface antigen and antibodies to hepatitis B e antigen

    NARCIS (Netherlands)

    ter Borg, F.; ten Kate, F. J.; Cuypers, H. T.; Leentvaar-Kuijpers, A.; Oosting, J.; Wertheim-van Dillen, P. M.; Honkoop, P.; Rasch, M. C.; de Man, R. A.; van Hattum, J.; Chamuleau, R. A.; Reesink, H. W.; Jones, E. A.

    1998-01-01

    BACKGROUND: Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B e antigen (anti-HBe) commonly coexist, and laboratory tests are often requested to assess histological hepatitis activity. An optimum panel of tests has not been found and the usefulness of hepatitis B virus (HBV) DNA

  12. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies

    International Nuclear Information System (INIS)

    Holers, V.M.; Kotzin, B.L.

    1985-01-01

    The authors used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases

  13. The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development

    DEFF Research Database (Denmark)

    Hviid, Lars

    2010-01-01

    There is substantial immuno-epidemiological evidence that the parasite-encoded, so-called variant surface antigens (VSAs) such as PfEMP1 on the surface of infected erythrocytes (IEs) are important-in some cases probably decisive-determinants of clinical outcome of P. falciparum malaria. The evide...

  14. Surface plasmon resonance is an analytically sensitive method for antigen profiling of extracellular vesicles

    NARCIS (Netherlands)

    Gool, Elmar L.; Stojanovic, Ivan; Schasfoort, Richardus B.M.; Sturk, Auguste; Van Leeuwen, Ton G.; Nieuwland, Rienk; Terstappen, Leon W.M.M.; Coumans, Frank A.W.

    2017-01-01

    BACKGROUND: Identification, enumeration, and characterization of extracellular vesicles (EVs) are hampered by the small size of EVs, a low refractive index, and low numbers of antigens on their surface. METHODS: We investigated the potential of a 48- multiplex surface plasmon resonance imaging

  15. Surface Plasmon Resonance is an Analytically Sensitive Method for Antigen Profiling of Extracellular Vesicles

    NARCIS (Netherlands)

    Gool, Elmar L.; Stojanovic, Ivan; Schasfoort, Richard B. M.; Sturk, Auguste; van Leeuwen, Ton G.; Nieuwland, Rienk; Terstappen, Leon W. M. M.; Coumans, Frank A. W.

    2017-01-01

    Identification, enumeration, and characterization of extracellular vesicles (EVs) are hampered by the small size of EVs, a low refractive index, and low numbers of antigens on their surface. We investigated the potential of a 48-multiplex surface plasmon resonance imaging (SPRi) system to perform EV

  16. The Effect of Superparamagnetic Iron Oxide Nanoparticle Surface Charge on Antigen Cross-Presentation.

    Science.gov (United States)

    Mou, Yongbin; Xing, Yun; Ren, Hongyan; Cui, Zhihua; Zhang, Yu; Yu, Guangjie; Urba, Walter J; Hu, Qingang; Hu, Hongming

    2017-12-01

    Magnetic nanoparticles (NPs) of superparamagnetic iron oxide (SPIO) have been explored for different kinds of applications in biomedicine, mechanics, and information. Here, we explored the synthetic SPIO NPs as an adjuvant on antigen cross-presentation ability by enhancing the intracellular delivery of antigens into antigen presenting cells (APCs). Particles with different chemical modifications and surface charges were used to study the mechanism of action of antigen delivery. Specifically, two types of magnetic NPs, γFe 2 O 3 /APTS (3-aminopropyltrimethoxysilane) NPs and γFe 2 O 3 /DMSA (meso-2, 3-Dimercaptosuccinic acid) NPs, with the same crystal structure, magnetic properties, and size distribution were prepared. Then, the promotion of T-cell activation via dendritic cells (DCs) was compared among different charged antigen coated NPs. Moreover, the activation of the autophagy, cytosolic delivery of the antigens, and antigen degradation mediated by the proteasome and lysosome were measured. Our results indicated that positive charged γFe 2 O 3 /APTS NPs, but not negative charged γFe 2 O 3 /DMSA NPs, enhanced the cross-presentation ability of DCs. Increased cross-presentation ability induced by γFe 2 O 3 /APTS NPs was associated with increased cytosolic antigen delivery. On the contrary, γFe 2 O 3 /DMSA NPs was associated with rapid autophagy. Overall, our results suggest that antigen delivered in cytoplasm induced by positive charged particles is beneficial for antigen cross-presentation and T-cell activation. NPs modified with different chemistries exhibit diverse biological properties and differ greatly in their adjuvant potentials. Thus, it should be carefully considered many different effects of NPs to design effective and safe adjuvants.

  17. Mendelian and non-mendelian mutations affecting surface antigen expression in Paramecium tetraurelia

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, L.M.; Forney, J.D.

    1984-08-01

    A screening procedure was devised for the isolation of X-ray-induced mutations affecting the expression of the A immobilization antigen (i-antigen) in Paramecium tetraurelia. Two of the mutations isolated by this procedure proved to be in modifier genes. The two genes are unlinked to each other and unlinked to the structural A i-antigen gene. These are the first modifier genes identified in a Paramecium sp. that affect surface antigen expression. Another mutation was found to be a deletion of sequences just downstream from the A i-antigen gene. In cells carrying this mutation, the A i-antigen gene lies in close proximity to the end of a macronuclear chromosome. The expression of the A i-antigen is not affected in these cells, demonstrating that downstream sequences are not important for the regulation and expression of the A i-antigen gene. A stable cell line was also recovered which shows non-Mendelian inheritance of a macronuclear deletion of the A i-antigen gene. This mutant does not contain the gene in its macronucleus, but contains a complete copy of the gene in its micronucleus. In the cytoplasm of wild-type animals, the micronuclear gene is included in the developing macronucleus; in the cytoplasm of the mutant, the incorporation of the A i-antigen gene into the macronucleus is inhibited. This is the first evidence that a mechanism is available in ciliates to control the expression of a gene by regulating its incorporation into developing macronuclei.

  18. Mendelian and non-mendelian mutations affecting surface antigen expression in Paramecium tetraurelia

    International Nuclear Information System (INIS)

    Epstein, L.M.; Forney, J.D.

    1984-01-01

    A screening procedure was devised for the isolation of X-ray-induced mutations affecting the expression of the A immobilization antigen (i-antigen) in Paramecium tetraurelia. Two of the mutations isolated by this procedure proved to be in modifier genes. The two genes are unlinked to each other and unlinked to the structural A i-antigen gene. These are the first modifier genes identified in a Paramecium sp. that affect surface antigen expression. Another mutation was found to be a deletion of sequences just downstream from the A i-antigen gene. In cells carrying this mutation, the A i-antigen gene lies in close proximity to the end of a macronuclear chromosome. The expression of the A i-antigen is not affected in these cells, demonstrating that downstream sequences are not important for the regulation and expression of the A i-antigen gene. A stable cell line was also recovered which shows non-Mendelian inheritance of a macronuclear deletion of the A i-antigen gene. This mutant does not contain the gene in its macronucleus, but contains a complete copy of the gene in its micronucleus. In the cytoplasm of wild-type animals, the micronuclear gene is included in the developing macronucleus; in the cytoplasm of the mutant, the incorporation of the A i-antigen gene into the macronucleus is inhibited. This is the first evidence that a mechanism is available in ciliates to control the expression of a gene by regulating its incorporation into developing macronuclei

  19. The Effect of Superparamagnetic Iron Oxide Nanoparticle Surface Charge on Antigen Cross-Presentation

    Science.gov (United States)

    Mou, Yongbin; Xing, Yun; Ren, Hongyan; Cui, Zhihua; Zhang, Yu; Yu, Guangjie; Urba, Walter J.; Hu, Qingang; Hu, Hongming

    2017-01-01

    Magnetic nanoparticles (NPs) of superparamagnetic iron oxide (SPIO) have been explored for different kinds of applications in biomedicine, mechanics, and information. Here, we explored the synthetic SPIO NPs as an adjuvant on antigen cross-presentation ability by enhancing the intracellular delivery of antigens into antigen presenting cells (APCs). Particles with different chemical modifications and surface charges were used to study the mechanism of action of antigen delivery. Specifically, two types of magnetic NPs, γFe2O3/APTS (3-aminopropyltrimethoxysilane) NPs and γFe2O3/DMSA (meso-2, 3-Dimercaptosuccinic acid) NPs, with the same crystal structure, magnetic properties, and size distribution were prepared. Then, the promotion of T-cell activation via dendritic cells (DCs) was compared among different charged antigen coated NPs. Moreover, the activation of the autophagy, cytosolic delivery of the antigens, and antigen degradation mediated by the proteasome and lysosome were measured. Our results indicated that positive charged γFe2O3/APTS NPs, but not negative charged γFe2O3/DMSA NPs, enhanced the cross-presentation ability of DCs. Increased cross-presentation ability induced by γFe2O3/APTS NPs was associated with increased cytosolic antigen delivery. On the contrary, γFe2O3/DMSA NPs was associated with rapid autophagy. Overall, our results suggest that antigen delivered in cytoplasm induced by positive charged particles is beneficial for antigen cross-presentation and T-cell activation. NPs modified with different chemistries exhibit diverse biological properties and differ greatly in their adjuvant potentials. Thus, it should be carefully considered many different effects of NPs to design effective and safe adjuvants.

  20. Surface proteome analysis and characterization of surface cell antigen (Sca or autotransporter family of Rickettsia typhi.

    Directory of Open Access Journals (Sweden)

    Khandra T Sears

    Full Text Available Surface proteins of the obligate intracellular bacterium Rickettsia typhi, the agent of murine or endemic typhus fever, comprise an important interface for host-pathogen interactions including adherence, invasion and survival in the host cytoplasm. In this report, we present analyses of the surface exposed proteins of R. typhi based on a suite of predictive algorithms complemented by experimental surface-labeling with thiol-cleavable sulfo-NHS-SS-biotin and identification of labeled peptides by LC MS/MS. Further, we focus on proteins belonging to the surface cell antigen (Sca autotransporter (AT family which are known to be involved in rickettsial infection of mammalian cells. Each species of Rickettsia has a different complement of sca genes in various states; R. typhi, has genes sca1 thru sca5. In silico analyses indicate divergence of the Sca paralogs across the four Rickettsia groups and concur with previous evidence of positive selection. Transcripts for each sca were detected during infection of L929 cells and four of the five Sca proteins were detected in the surface proteome analysis. We observed that each R. typhi Sca protein is expressed during in vitro infections and selected Sca proteins were expressed during in vivo infections. Using biotin-affinity pull down assays, negative staining electron microscopy, and flow cytometry, we demonstrate that the Sca proteins in R. typhi are localized to the surface of the bacteria. All Scas were detected during infection of L929 cells by immunogold electron microscopy. Immunofluorescence assays demonstrate that Scas 1-3 and 5 are expressed in the spleens of infected Sprague-Dawley rats and Scas 3, 4 and 5 are expressed in cat fleas (Ctenocephalides felis. Sca proteins may be crucial in the recognition and invasion of different host cell types. In short, continuous expression of all Scas may ensure that rickettsiae are primed i to infect mammalian cells should the flea bite a host, ii to remain

  1. Determinants of spontaneous surface antigen loss in hepatitis B e antigen-negative patients with a low viral load.

    Science.gov (United States)

    Tseng, Tai-Chung; Liu, Chun-Jen; Yang, Hung-Chih; Su, Tung-Hung; Wang, Chia-Chi; Chen, Chi-Ling; Kuo, Stephanie Fang-Tzu; Liu, Chen-Hua; Chen, Pei-Jer; Chen, Ding-Shinn; Kao, Jia-Horng

    2012-01-01

    Loss of hepatitis B surface antigen (HBsAg) usually indicates the cure of hepatitis B virus (HBV) infection. In spontaneous hepatitis B e antigen (HBeAg) seroconverters, lower serum HBsAg and HBV DNA levels have been shown to be associated with HBsAg loss over time. However, little is known about their impacts on HBsAg loss in HBeAg-negative patients with limited viral replication. A total of 688 HBeAg-negative patients with baseline serum HBV DNA levels loss were investigated. In a mean follow-up of 11.6 years, the average annual rate of HBsAg loss was 1.6%. Baseline HBsAg and HBV DNA levels were inversely associated with subsequent HBsAg loss. When compared to patients who had HBsAg levels >1000 IU/mL, the rates of HBsAg loss were significantly higher in patients with HBsAg levels of 100-999, 10-99, and loss was 13.2 (95% CI, 7.8-22.1) for HBsAg level loss. In HBeAg-negative patients with HBV genotype B or C infection who have HBV DNA level loss. Copyright © 2011 American Association for the Study of Liver Diseases.

  2. In silico Analysis of Immunologic Regions of Surface Antigens (Sags of Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Abbas Alibakhshi

    2017-06-01

    Full Text Available Background: Surface antigens (SAGs of Toxoplasma gondii are known candidates for diagnostic tests and vaccines. The present study argues about the main necessary properties for determination and prediction of T-cell agretopes and B-cell epitopes of surface antigens of Toxoplasma gondii.Materials and Methods: Primary, secondary and tertiary structures of the proteins were analyzed by different methods. The three-dimensional structures were determined by use of ab initio method for prediction of discontinues epitopes. The agretopes and epitopes were predicted via several various web servers with different methods employed.Results: The results of in silico analyses showed that the regions 129-GAPAGRNNDGSSAPT-143 for protein p22, 234-SENPWQGNASSD-245 for protein p30 and 348-PGTEGESQAGT-358 for protein p43, have the highest immunogenic potential.Conclusion: We reached to three antigenic epitopes for cloning and protein expression. In following the purified polypeptide will be applied for diagnosis of Toxoplasma gondii.

  3. Hepatitis B-Surface Antigen In Ascitic Fluid Of Patients With Chronic ...

    African Journals Online (AJOL)

    A prospective evaluation of eleven consecutive cases of chronic liver disease over a twelve-month period was carried out clinically and ultrasonographically. By the use of the method of reverse passive haemagglutination, sera and ascitic fluid of the patients were tested for the presence of the Hepatitis B surface antigen.

  4. Prevalence of Hepatitis B Surface Antigen (HBsAg) Amongst Alcohol ...

    African Journals Online (AJOL)

    The prevalence of Hepatitis B surface Antigen was studied amongst alcohol consumers and non– consumers (Control subjects) in Bassa Local Government Area (LGA) of Plateau State. Three hundred and five (305) subjects comprising 255(83.61%) alcoholics and 50(16.39%) non-alcoholic control subjects were screened ...

  5. Identification and Characterization of Ixodes scapularis Antigens That Elicit Tick Immunity Using Yeast Surface Display

    NARCIS (Netherlands)

    Schuijt, T.J.; Narasimhan, S.; Daffre, S.; Deponte, K.; Hovius, J.W.R.; van 't Veer, C.; van der Poll, T.; Bakhtiari, K.; Meijers, J.C.M.; Boder, E.T.; van Dam, A.P.; Fikrig, E.

    2011-01-01

    Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary

  6. Surface antigen-negative hepatitis B virus infection in Dutch blood donors

    NARCIS (Netherlands)

    Lieshout-Krikke, R. W.; Molenaar-de Backer, M. W. A.; van Swieten, P.; Zaaijer, H. L.

    2014-01-01

    Hepatitis B virus (HBV) surface antigen (HBsAg) is a reliable marker for HBV infection, but HBsAg-negative forms of HBV infection occur. The introduction of HBV DNA screening of Dutch blood donors, which were not preselected for absence of HBV core antibodies, enabled the characterization of

  7. Prevalence of Hepatitis-B Surface Antigen among Blood Donors in ...

    African Journals Online (AJOL)

    Information is scarce on the prevalence of Hepatitis-B Virus (HBV) infection among blood donors in Taraba State. Hepatitis-B surface antigen (HBsAg) ELISA [Gudans Industrial Hong 2 Kou, China] was used to determine the prevalence of HBsAg among 804 blood donors aged between 11 and 65 years in Federal Medical ...

  8. Multiple surface antigen mutations in five blood donors with occult hepatitis B virus infection

    NARCIS (Netherlands)

    Zaaijer, H. L.; Torres, P.; Ontañón, A.; Ponte, L. González; Koppelman, M. H. G. M.; Lelie, P. N.; Hemert, F. J. van; Boot, H. J.

    2008-01-01

    Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA while the HBV surface antigen (HBsAg) remains undetectable. The HBV genomes in five asymptomatic blood donors with occult HBV infection and low viremia ( <10 to 1,000 HBV DNA copies/mL, genotype D) were studied. An

  9. Prevalence of Hepatitis-B Surface Antigen (HbsAg), Hepatitis C ...

    African Journals Online (AJOL)

    The prevalence of Hepatitis-B surface antigen (HBsAg), Hepatitis C virus (HCV) and Human immunodeficiency virus (HIV) was determined among apparently healthy male blood donors in Aminu Kano Teaching Hospital, Kano, between January and December, 2002. A total of 2,288 blood samples from the blood donors ...

  10. A sensitive immunoradiometric assay for the detection of hepatitis B surface antigen

    International Nuclear Information System (INIS)

    Cameron, C.H.; Combridge, B.S.; Howell, D.R.; Barbara, J.A.J.

    1980-01-01

    A solid-phase immunoradiometric assay for hepatitis B surface antigen is described which has been in use since 1972. Initially it was used for reference laboratory work, but from 1974 it has also been used for screening blood and blood products. Methods for the production of reagents and their use in blood transfusion and reference work, are outlined. (Auth.)

  11. Method to conjugate polysaccharide antigens to surfaces for the detection of antibodies

    DEFF Research Database (Denmark)

    Boas, Ulrik; Lind, Peter; Riber, Ulla

    2014-01-01

    microbeads modified with N-alkyl hydroxylamine and N-alkyl-O-methyl hydroxylamine surface groups by incubation of antigen and beads for 16 h at 40 oC without the need for coupling agents. The efficiency of the new method was evaluated by flow cytometry in model samples and serum samples containing antibodies...

  12. Sero-prevalence of Hepatitis B Surface Antigen (HBsAg), in Sexually ...

    African Journals Online (AJOL)

    Sero-prevalence of Hepatitis B Surface Antigen (HBsAg), in Sexually Transmitted Disease Patients. ... partners in the past 6 months, a history of a number of episodes of STDs, history of heterosexual exposure to partners at risk, for example prostitutes; a history of symptoms of an STD at the commencement of the study.

  13. A Survey about Protective Effect of Echinococcus Granulosus Protoscolices Surface Antigens in Preventing Secondary Hydatid Cyst

    Directory of Open Access Journals (Sweden)

    H Yousofi

    2006-10-01

    Full Text Available ABSTRACT: Introduction & Objective: Hydatid cyst is located in human and some animal visceral organs such as liver and lung. The disease is considered as a medical, veterinary and economical problem in endemic area. When the hydatid cyst is ruptured, protoscolices from inside the cyst may spread out to other parts of the body and develops a new cyst named secondary hydatid cyst. In this research in an attempt to prevent secondary hydatid cyst, protective potential of protoscolices surface antigens extracted with different detergents has been investigated in animal model. Materials & Methods: In this experimental study, groups of Balb/c mice were immunized intra-peritoneally with protoscolices homogenate and three detergent (SDS, Tween and Triton x–100 extracted protoscolices surface antigens and alum as adjuvant. These mice were then boosted two times with the same antigens fortnightly. Control mice were simultaneously injected with alum alone. Two weeks following the last injection all the mice in cases and control groups were challenged with live protoscolices. Three months afterward all the mice in case and control groups were sacrificed and their peritoneal cavities were explored for hydatid cysts. Results: The mean of developed cyst number in mice injected with protoscolices homogenate was 3±2, while in control group the mean of developed cysts number was 5.8 ± 1.7 (p< 0.02. The mean of developed cyst number in mice injected with SDS, Tween and Triton x–100 extracted protoscolices surface antigens was 3, 3.6 and 3.4, respectively, while the mean of developed cyst number in control group was 5.8. Conclusion: The mean of cyst number in cases and control groups was different and this difference was statistically significant. Results of this investigation revealed that protoscolices homogenate antigens and some detergent extracted antigens are protective against secondary hydatid cyst infection

  14. Identification of Bacterial Surface Antigens by Screening Peptide Phage Libraries Using Whole Bacteria Cell-Purified Antisera

    Science.gov (United States)

    Hu, Yun-Fei; Zhao, Dun; Yu, Xing-Long; Hu, Yu-Li; Li, Run-Cheng; Ge, Meng; Xu, Tian-Qi; Liu, Xiao-Bo; Liao, Hua-Yuan

    2017-01-01

    Bacterial surface proteins can be good vaccine candidates. In the present study, we used polyclonal antibodies purified with intact Erysipelothrix rhusiopthiae to screen phage-displayed random dodecapeptide and loop-constrained heptapeptide libraries, which led to the identification of mimotopes. Homology search of the mimotope sequences against E. rhusiopthiae-encoded ORF sequences revealed 14 new antigens that may localize on the surface of E. rhusiopthiae. When these putative surface proteins were used to immunize mice, 9/11 antigens induced protective immunity. Thus, we have demonstrated that a combination of using the whole bacterial cells to purify antibodies and using the phage-displayed peptide libraries to determine the antigen specificities of the antibodies can lead to the discovery of novel bacterial surface antigens. This can be a general approach for identifying surface antigens for other bacterial species. PMID:28184219

  15. Quantitative Measurement of Serum Hepatitis B Surface Antigen Using an Immunoradiometric Assay in Chronic Hepatitis B

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Woo; Lee, Ho Young; Kim, Seog Gyun; Kim, Won; Jung, Wong Jin; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National Univ. Seoul (Korea, Republic of)

    2011-03-15

    Measurement of serum hepatitis B virus surface antigen (HBsAg) levels is important for the management of chronic hepatitis D patients in terms of monitoring response to antiviral therapy. This study aimed to evaluate the diagnostic performance of a new diagnostic kit, which quantitatively measures serum HBsAg level using an immunoradiometric assay (IRMA) based method. Measurements were compared with those obtained using a chemiluminescent microparticle immunoassay (CMIA) based method. The blood samples of 96 patients with chronic hepatitis B were used in this study. Copy numbers of serum hepatitis B virus (HBV) DNA were determined in 23 of these samples. The correlation between and the concordance of IRMA and CMIA results were determined using Pearson's correlation coefficients. P values of 0.05 were considered to be statistically significant throughout. Laboratory diagnoses based on CMIA. Furthermors, serum HBsAg levels by IRMA were found to be highly correlated with those determined by CMIA (correlation coefficient R{sup 2=}0.838, P<0.001). Serum HBsAg level and serum HBV DNA copies were found to be linearly related by both methods (R{sup 2=}0.067, P=0.316 by IRMA, and R{sup 2=}0.101, P=0.215 by CMIA). The diagnostic performance of the investigated IRMA method of determining HBsAg levels was found to be comparable with that of a CMIA based method in chronic hepatitis B patients.

  16. Variants of a Leishmania surface antigen derived from a multigenic family.

    Science.gov (United States)

    Murray, P J; Spithill, T W

    1991-12-25

    The promastigote surface antigen-2 (PSA-2) complex comprises a group of immunogenic surface antigens linked to the surface of the Leishmania major promastigote with glycosylphosphatidylinositol anchors. The L. major genome contains at least 14 PSA-2 genes on a 950-kilobase chromosome and comprising approximately 20% of the length of this chromosome. The sequence of three independent, but incomplete, PSA-2 cDNAs and one genomic fragment encoding a complete PSA-2 coding sequence were compared. PSA-2 genes encode polypeptides exhibiting 22-25aa tandem repeat elements, threonine-rich segments which vary between genes, a conserved COOH-terminal cysteine-rich region, and a conserved GPI anchor signal sequence. PSA-2 genes appear to be transcribed in a complex manner with multiple RNAs. The complex genomic organization of PSA-2 genes is present in other members of the genus suggesting that PSA-2 function is important for the biology of Leishmania.

  17. Genomic Characterization of Variable Surface Antigens Reveals a Telomere Position Effect as a Prerequisite for RNA Interference-Mediated Silencing in Paramecium tetraurelia

    Science.gov (United States)

    Baranasic, Damir; Oppermann, Timo; Cheaib, Miriam; Cullum, John; Schmidt, Helmut

    2014-01-01

    ABSTRACT Antigenic or phenotypic variation is a widespread phenomenon of expression of variable surface protein coats on eukaryotic microbes. To clarify the mechanism behind mutually exclusive gene expression, we characterized the genetic properties of the surface antigen multigene family in the ciliate Paramecium tetraurelia and the epigenetic factors controlling expression and silencing. Genome analysis indicated that the multigene family consists of intrachromosomal and subtelomeric genes; both classes apparently derive from different gene duplication events: whole-genome and intrachromosomal duplication. Expression analysis provides evidence for telomere position effects, because only subtelomeric genes follow mutually exclusive transcription. Microarray analysis of cultures deficient in Rdr3, an RNA-dependent RNA polymerase, in comparison to serotype-pure wild-type cultures, shows cotranscription of a subset of subtelomeric genes, indicating that the telomere position effect is due to a selective occurrence of Rdr3-mediated silencing in subtelomeric regions. We present a model of surface antigen evolution by intrachromosomal gene duplication involving the maintenance of positive selection of structurally relevant regions. Further analysis of chromosome heterogeneity shows that alternative telomere addition regions clearly affect transcription of closely related genes. Consequently, chromosome fragmentation appears to be of crucial importance for surface antigen expression and evolution. Our data suggest that RNAi-mediated control of this genetic network by trans-acting RNAs allows rapid epigenetic adaptation by phenotypic variation in combination with long-term genetic adaptation by Darwinian evolution of antigen genes. PMID:25389173

  18. Prostate-specific antigen and long-term prediction of prostate cancer incidence and mortality in the general population

    DEFF Research Database (Denmark)

    Orsted, David D; Nordestgaard, Børge G; Jensen, Gorm B

    2012-01-01

    It is largely unknown whether prostate-specific antigen (PSA) level at first date of testing predicts long-term risk of prostate cancer (PCa) incidence and mortality in the general population.......It is largely unknown whether prostate-specific antigen (PSA) level at first date of testing predicts long-term risk of prostate cancer (PCa) incidence and mortality in the general population....

  19. Identification and characterization of Ixodes scapularis antigens that elicit tick immunity using yeast surface display.

    Directory of Open Access Journals (Sweden)

    Tim J Schuijt

    2011-01-01

    Full Text Available Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary antigens that react with tick-immune serum. We constructed an Ixodes scapularis nymphal salivary gland yeast surface display library and screened the library with nymph-immune rabbit sera and identified five salivary antigens. Four of these proteins, designated P8, P19, P23 and P32, had a predicted signal sequence. We generated recombinant (r P8, P19 and P23 in a Drosophila expression system for functional and immunization studies. rP8 showed anti-complement activity and rP23 demonstrated anti-coagulant activity. Ixodes scapularis feeding was significantly impaired when nymphs were fed on rabbits immunized with a cocktail of rP8, rP19 and rP23, a hall mark of tick-immunity. These studies also suggest that these antigens may serve as potential vaccine candidates to thwart tick feeding.

  20. Neospora caninum surface antigen (p40) is a potential diagnostic marker for cattle neosporosis.

    Science.gov (United States)

    He, Pengfei; Li, Jianhua; Gong, Pengtao; Liu, Chengwu; Zhang, Guocai; Yang, Ju; Tuo, Wenbin; Yang, Bintong; Zhang, Xichen

    2013-05-01

    Neospora caninum is an intracellular protozoan that infects domestic and wild canids as well as many warm-blooded animals as shown by the isolation of viable parasites. The effectiveness of diagnostic tests for detecting specific antibodies against N. caninum is hampered by potential cross-reaction with other Coccidia. So, there is currently an urgent need for a sensitive and specific diagnostic assay for detecting N. caninum in animals. The N. caninum 40-kD surface antigen (p40), similar to NcSAG1 and NcSRS2, was shown to belong to surface antigen super family and thus represents an excellent marker for the diagnosis of neosporosis. In order to test the hypothesis, recombinant Ncp40 (rNcp40) was expressed in Escherichia coli, and an indirect ELISA test was developed using recombinant NCp40 antigen for N. caninum serodiagnosis. The antigen used in this study did not have cross-reactivity with anti-Toxoplasma gondii serum. Anti-p40 antibodies were detected by ELISA in the sera of Yellow cattle and were compared with (IFAT). Optimal sensitivity and specificity (98.2 and 98.6 %) were identified by IFAT. Additionally, 37 positive sera of T. gondii were detected and there was no significant difference with the negative serum of N. caninum. The rNcp40 ELISA developed here provides a specific and sensitive assay for detecting neosporosis in cattle.

  1. A radioimmunoassay for antibodies against surface membrane antigens using adhering cells

    International Nuclear Information System (INIS)

    Tax, A.; Manson, L.A.

    1976-01-01

    A radioimmunoassay using cells adhering to plastic is described. In this assay, A-10 mammary carcinoma attached to the surface of plastic in microtiter plates were permitted to bind antibody and the bound antibody was detected with purified rabbit 125 I-antimouse-Fab. The bound radioactive material was eluted with glycine-HCl buffer (pH 2.5), and the acid eluates were counted in a gamma counter. This assay can be used to detect cytolic or noncytolic antibody to cell surface antigens in studies with any tumor or normal cell that will adhere to a solid surface

  2. The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development

    DEFF Research Database (Denmark)

    Hviid, Lars

    2010-01-01

    that development of PfEMP1-based vaccines to protect specifically against severe malaria syndromes-in particular PAM-is feasible. This review summarizes the evidence that VSAs are important targets of NAI, discusses why VSA-based vaccines might be feasible despite the extensive intra- and interclonal variation...... of VSAs, and how vaccines based on this type of antigens fit into the current global strategy to reduce, eliminate and eventually eradicate the burden of malaria.......There is substantial immuno-epidemiological evidence that the parasite-encoded, so-called variant surface antigens (VSAs), such as PfEMP1 on the surface of infected erythrocytes (IEs) are important-in some cases probably decisive determinants of clinical outcome of P. falciparum malaria...

  3. High hepatitis B surface antigen levels predict insignificant fibrosis in hepatitis B e antigen positive chronic hepatitis B.

    Directory of Open Access Journals (Sweden)

    Wai-Kay Seto

    Full Text Available INTRODUCTION: There is no data on the relationship between hepatitis B surface antigen (HBsAg levels and liver fibrosis in hepatitis B e antigen (HBeAg-positive patients with chronic hepatitis B (CHB. METHODS: Serum HBsAg and HBV DNA levels in HBeAg-positive CHB patients with liver biopsies were analyzed. The upper limit of normal (ULN of alanine aminotransferase (ALT was 30 and 19 U/L for men and women respectively. Histologic assessment was based on Ishak fibrosis staging for fibrosis and Knodell histologic activity index (HAI for necroinflammation. RESULTS: 140 patients (65% male, median age 32.7 years were recruited. 56 (40% had ALT ≤2×ULN. 72 (51.4% and 42 (30% had fibrosis score ≤ 1 and necroinflammation grading ≤ 4 respectively. Patients with fibrosis score ≤ 1, when compared to patients with fibrosis score >1, had significantly higher median HBsAg levels (50,320 and 7,820 IU/mL respectively, p<0.001. Among patients with ALT ≤2×ULN, serum HBsAg levels achieved an area under receiver operating characteristic curve of 0.869 in predicting fibrosis score ≤ 1. HBsAg levels did not accurately predict necroinflammation score. HBsAg ≥ 25,000 IU/mL was independently associated with fibrosis score ≤ 1 (p=0.025, odds ratio 9.042.Using this cut-off HBsAg level in patients with ALT ≤2×ULN, positive and negative predictive values for predicting fibrosis score ≤ 1 were 92.7% and 60.0% respectively. HBV DNA levels had no association with liver histology. CONCLUSION: Among HBeAg-positive patients with ALT ≤2×ULN, high serum HBsAg levels can accurately predict fibrosis score ≤ 1, and could potentially influence decisions concerning treatment commencement and reduce the need for liver biopsy.

  4. An overview of serum prostatic surface antigen cut points for recommendation of prostatic biopsy

    OpenAIRE

    Patwardhan, Sujata K.; Patil, Bhushan P.; Shelke, Umesh Ravikant; Singh, Abhishek G.

    2018-01-01

    Introduction: Patients in India frequently present with prostatic surface antigen (PSA) report and request for prostatic biopsy to rule out malignancy. With fear of harboring malignancy set in patient's mind, it becomes difficult to counsel them about absolute indications and need of biopsy. Whether serum PSA has same predictability in symptomatic patients in the Indian context for advising prostatic biopsy at same reference ranges as in western countries, remains to be answered. Materials an...

  5. Characterization of a Monoclonal Antibody Specific for the Parasite Surface Antigen-2 of Leishmania major

    OpenAIRE

    "AR Khabiri; F Bagheri; SR Naddaf; M Assmar; A Hosseini Taghavi"

    2004-01-01

    The Leishmania major Parasite surface Antigen-2 (PSA-2) is a family of glycoinositol phospholipids anchored glycoprotoins expressed in both promastigotes and amastigotes. Promastigote PSA-2 comprises three polypeptides with approximate molecular weight of 96, 80 and 50 kDa. Amastigote express a distinct but closely PSA-2 polypeptide with molecular weight of 50 kDa. In this study fusion of SP2/0 myeloma cells with immunized mice spleenocytes infected with promastigotes of L. major intraperiton...

  6. Evaluation the Surface Antigen of the Salmonella typhimurium ATCC 14028 Ghosts Prepared by “SLRP”

    Directory of Open Access Journals (Sweden)

    Amara A. Amro

    2014-01-01

    Full Text Available Recently, bacterial ghosts (BGs were prepared using a protocol based on critical chemical concentrations. It has been given the name “sponge like” (SL protocol and used in its reduced form “sponge like reduced protocol” (SLRP. While specific antibody for Salmonella is available on the market under the commercial names (of some kits such as Febrile Antigen Kit (N.S. BIO-TEC, we used the described Kit to investigate the validity of the SLRP. In this study, using SLRP we succeeded to prepare STGs with correct surface antigens could interact with their specific antibodies. Additionally the study has included oral vaccination with STGs with challenge test. The rats serums have been evaluated against both of the O and H antigens. The antigen-antibody interaction (agglutination results of both the SLRP and the animal experiments prove that we have correct STGs able to immunize the rats against viable Salmonella. STGs could be used as vaccine and as adjuvant and in the antibodies and in the diagnostic kits production. This study is an additional step for the establishment of correct BGs for immunological purposes.

  7. Cell surface antigens of radiation leukemia virus-induced BALB/c leukemias defined by syngeneic cytotoxic T lymphocytes

    International Nuclear Information System (INIS)

    Kaneko, Yukio; Oettgen, H.F.; Obata, Yuichi; Nakayama, Eiichi.

    1989-01-01

    Two cell surface antigens of mouse leukemias were defined by BALB/c cytotoxic T lymphocytes (CTL) generated against syngeneic radiation leukemia virus (RadLV)-induced leukemia, BALBRV1 or BALBRVD. Hyperimmunization of BALB/c mice with irradiated leukemias followed by in vitro sensitization of primed spleen cells resulted in the generation of CTL with high killing activity. The specificity of CTL was examined by direct cytotoxicity assays and competitive inhibition assays. A shared cell surface antigen, designated as BALBRV1 antigen, was detected by BALB/c anti-BALBRV1 CTL. BALBRV1 antigen was expressed not only on RadLV-induced BALB/c leukemias except for BALBRVD, but also on spontaneous or X-ray-induced BALB/c leukemias, chemically-induced leukemias with the H-2 d haplotype and some chemically-induced BALB/c sarcomas. In contrast, a unique cell surface antigen, designated as BALBRVD antigen, was detected by BALB/c anti-BALBRVD CTL. BALBRVD antigen was expressed only on BALBRVD, but not on thirty-nine normal lymphoid or tumor cells. These two antigens could be distinguished from those previously defined on Friend, Moloney, Rauscher or Gross murine leukemia virus (MuLV) leukemias, or MuLV-related antigens. Both cytotoxic responses were blocked by antisera against H-2K d , but not H-2D d . The relationship of BALBRV1 antigen and BALBRVD antigen to endogenous MuLV is discussed with regard to the antigenic distribution on tumor cell lines. (author)

  8. Immuno disc assay for screening duck hepatitis B surface antigen in serum, liver tissue and cultured hepatocytes

    NARCIS (Netherlands)

    G.A. de Wilde (G.); R.A. Heijtink

    1993-01-01

    textabstractAn immuno disc assay (IDA) for semi-quantitative analysis of the surface antigen (DHBsAg) of duck hepatitis B virus (DHBV) is described. Unpurified antigen preparations were adsorbed onto punched-out nitrocellulose membrane discs. Rabbit antiserum raised against serum-derived

  9. Simulation and Theory of Antibody Binding to Crowded Antigen-Covered Surfaces.

    Directory of Open Access Journals (Sweden)

    Cristiano De Michele

    2016-03-01

    Full Text Available In this paper we introduce a fully flexible coarse-grained model of immunoglobulin G (IgG antibodies parametrized directly on cryo-EM data and simulate the binding dynamics of many IgGs to antigens adsorbed on a surface at increasing densities. Moreover, we work out a theoretical model that allows to explain all the features observed in the simulations. Our combined computational and theoretical framework is in excellent agreement with surface-plasmon resonance data and allows us to establish a number of important results. (i Internal flexibility is key to maximize bivalent binding, flexible IgGs being able to explore the surface with their second arm in search for an available hapten. This is made clear by the strongly reduced ability to bind with both arms displayed by artificial IgGs designed to rigidly keep a prescribed shape. (ii The large size of IgGs is instrumental to keep neighboring molecules at a certain distance (surface repulsion, which essentially makes antigens within reach of the second Fab always unoccupied on average. (iii One needs to account independently for the thermodynamic and geometric factors that regulate the binding equilibrium. The key geometrical parameters, besides excluded-volume repulsion, describe the screening of free haptens by neighboring bound antibodies. We prove that the thermodynamic parameters govern the low-antigen-concentration regime, while the surface screening and repulsion only affect the binding at high hapten densities. Importantly, we prove that screening effects are concealed in relative measures, such as the fraction of bivalently bound antibodies. Overall, our model provides a valuable, accurate theoretical paradigm beyond existing frameworks to interpret experimental profiles of antibodies binding to multi-valent surfaces of different sorts in many contexts.

  10. Antigenic variation and the genetics and epigenetics of the PfEMP1 erythrocyte surface antigens in Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Arnot, David E; Jensen, Anja T R

    2011-01-01

    How immunity to malaria develops remains one of the great unresolved issues in bio-medicine and resolution of its various paradoxes is likely to be the key to developing effective malaria vaccines. The basic epidemiological observations are; under conditions of intense natural transmission, humans...... on the function and control of this multi-gene family of parasite variable surface antigens....

  11. A putative, novel coli surface antigen 8B (CS8B) of enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Njoroge, Samuel M; Boinett, Christine J; Madé, Laure F; Ouko, Tom T; Fèvre, Eric M; Thomson, Nicholas R; Kariuki, Samuel

    2015-10-01

    Enterotoxigenic Escherichia coli (ETEC) strains harbor multiple fimbriae and pili to mediate host colonization, including the type IVb pilus, colonization factor antigen III (CFA/III). Not all colonization factors are well characterized or known in toxin positive ETEC isolates, which may have an impact identifying ETEC isolates based on molecular screening of these biomarkers. We describe a novel coli surface antigen (CS) 8 subtype B (CS8B), a family of CFA/III pilus, in a toxin producing ETEC isolate from a Kenyan collection. In highlighting the existence of this putative CS, we provide the sequence and specific primers, which can be used alongside other ETEC primers previously described. © FEMS 2015.

  12. Surface expression of Helicobacter pylori HpaA adhesion antigen on Vibrio cholerae, enhanced by co-expressed enterotoxigenic Escherichia coli fimbrial antigens.

    Science.gov (United States)

    Tobias, Joshua; Lebens, Michael; Wai, Sun Nyunt; Holmgren, Jan; Svennerholm, Ann-Mari

    2017-04-01

    Helicobacter pylori infection can cause peptic ulceration and is associated with gastric adenocarcinoma. This study aimed to construct and characterize a non-virulent Vibrio cholerae O1 strain, which grows more rapidly than H. pylori, as vector for H. pylori antigens for possible use as a vaccine strain against H. pylori. This was done by recombinant expression of the H. pylori adhesion antigen HpaA alone or, as a proof of principle, together with different colonization factor (CF) antigens of enterotoxigenic Escherichia coli (ETEC) which may enhance immune responses against HpaA. A recombinant V. cholerae strain co-expressing HpaA and a fimbrial CF antigens CFA/I or CS5, but not the non-fimbrial CF protein CS6, was shown to express larger amounts of HpaA on the surface when compared with the same V. cholerae strain expressing HpaA alone. Mutations in the CFA/I operon showed that the chaperon, possibly together with the usher, was involved in enhancing the surface expression of HpaA. Oral immunization of mice with formaldehyde-inactivated recombinant V. cholerae expressing HpaA alone or together with CFA/I induced significantly higher serum antibody responses against HpaA than mice similarly immunized with inactivated HpaA-expressing H. pylori bacteria. Our results demonstrate that a non-virulent V. cholerae strain can be engineered to allow strong surface expression of HpaA, and that the expression can be further increased by co-expressing it with ETEC fimbrial antigens. Such recombinant V. cholerae strains expressing HpaA, and possibly also other H. pylori antigens, may have the potential as oral inactivated vaccine candidates against H. pylori. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Effect of UV radiation on the surface of mammalian immunocompetent cells. 1. The change in expression of some antigens and receptors of murine spleen lymphocyte surface

    Energy Technology Data Exchange (ETDEWEB)

    Krylenkov, V.A.; Malygin, A.M. (AN SSSR, Leningrad. Inst. Tsitologii)

    1982-12-01

    Short-wave (254nm) and long-wave (365 nm) UV rays (ShUS and LUV rays) induce the increase in the expression of surface markers of T lymphocytes-THETA(Thy-1) antigens and B lymphocytes-MBLA-antigens and EAS receptors when affecting mouse spleen cells in nonlethal and small lethal doses. Total cell content with T and B lymphocyte characters in an irradiated suspension exceeds even the total cell quantity in non-irradiated suspension (100%) which points to the possibility of the expression of plasmatic membrane antigens and receptors not manifested on the surface of nonirradiated lymphocytes. In the isolethal dose range (LD/sup 15/-LD/sup 28/) ShUV rays suppress and LUV rays induce further increase of THETA and MBLA antigens expression. Among B lymphocytes surface markers the MBLA antigens are more resistant to ShUV an LUV radiation as compared with the EAC receptors.

  14. Surface-Engineering of Red Blood Cells as Artificial Antigen Presenting Cells Promising for Cancer Immunotherapy.

    Science.gov (United States)

    Sun, Xiaoqi; Han, Xiao; Xu, Ligeng; Gao, Min; Xu, Jun; Yang, Rong; Liu, Zhuang

    2017-10-01

    The development of artificial antigen presenting cells (aAPCs) to mimic the functions of APCs such as dendritic cells (DCs) to stimulate T cells and induce antitumor immune responses has attracted substantial interests in cancer immunotherapy. In this work, a unique red blood cell (RBC)-based aAPC system is designed by engineering antigen peptide-loaded major histocompatibility complex-I and CD28 activation antibody on RBC surface, which are further tethered with interleukin-2 (IL2) as a proliferation and differentiation signal. Such RBC-based aAPC-IL2 (R-aAPC-IL2) can not only provide a flexible cell surface with appropriate biophysical parameters, but also mimic the cytokine paracrine delivery. Similar to the functions of matured DCs, the R-aAPC-IL2 cells can facilitate the proliferation of antigen-specific CD8+ T cells and increase the secretion of inflammatory cytokines. As a proof-of-concept, we treated splenocytes from C57 mice with R-aAPC-IL2 and discovered those splenocytes induced significant cancer-cell-specific lysis, implying that the R-aAPC-IL2 were able to re-educate T cells and induce adoptive immune response. This work thus presents a novel RBC-based aAPC system which can mimic the functions of antigen presenting DCs to activate T cells, promising for applications in adoptive T cell transfer or even in direct activation of circulating T cells for cancer immunotherapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    International Nuclear Information System (INIS)

    Patters, M.R.; Landsberg, R.L.; Johansson, L.-A.; Trummel, C.L.; Robertson, P.R.

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated 45 Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis. (author)

  16. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    Energy Technology Data Exchange (ETDEWEB)

    Patters, M.R.; Landsberg, R.L.; Johansson, L.A.; Trummel, C.L.; Robertson, P.R. (Department of Periodontology, University of Connecticut, School of Dental Medicine, Farmington, Connecticut, U.S.A.)

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated /sup 45/Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis.

  17. Rapid and specific biotin labelling of the erythrocyte surface antigens of both cultured and ex-vivo Plasmodium parasites

    Directory of Open Access Journals (Sweden)

    Thompson Joanne

    2007-05-01

    Full Text Available Abstract Background Sensitive detection of parasite surface antigens expressed on erythrocyte membranes is necessary to further analyse the molecular pathology of malaria. This study describes a modified biotin labelling/osmotic lysis method which rapidly produces membrane extracts enriched for labelled surface antigens and also improves the efficiency of antigen recovery compared with traditional detergent extraction and surface radio-iodination. The method can also be used with ex-vivo parasites. Methods After surface labelling with biotin in the presence of the inhibitor furosemide, detergent extraction and osmotic lysis methods of enriching for the membrane fractions were compared to determine the efficiency of purification and recovery. Biotin-labelled proteins were identified on silver-stained SDS-polyacrylamide gels. Results Detergent extraction and osmotic lysis were compared for their capacity to purify biotin-labelled Plasmodium falciparum and Plasmodium chabaudi erythrocyte surface antigens. The pellet fraction formed after osmotic lysis of P. falciparum-infected erythrocytes is notably enriched in suface antigens, including PfEMP1, when compared to detergent extraction. There is also reduced co-extraction of host proteins such as spectrin and Band 3. Conclusion Biotinylation and osmotic lysis provides an improved method to label and purify parasitised erythrocyte surface antigen extracts from both in vitro and ex vivo Plasmodium parasite preparations.

  18. Naturally-acquired cellular immune response against Plasmodium vivax merozoite surface protein-1 paralog antigen.

    Science.gov (United States)

    Changrob, Siriruk; Leepiyasakulchai, Chaniya; Tsuboi, Takafumi; Cheng, Yang; Lim, Chae Seung; Chootong, Patchanee; Han, Eun-Taek

    2015-04-15

    Plasmodium vivax merozoite surface protein-1 paralog (PvMSP1P) is a glycosylphosphatidylinositol-anchored protein expressed on the merozoite surface. This molecule is a target of natural immunity, as high anti-MSP1P-19 antibody levels were detected during P. vivax infection and the antibody inhibited PvMSP1P-erythrocyte binding. Recombinant PvMSP1P antigen results in production of a significant Th1 cytokine response in immunized mice. The present study was performed to characterize natural cellular immunity against PvMSP1P-19 and PvDBP region II in acute and recovery P. vivax infection. Peripheral blood mononuclear cells (PBMCs) from acute and recovery P. vivax infection were obtained for lymphocyte proliferation assay upon PvMSP1P-19 and PvDBP region II antigen stimulation. The culture supernatant was examined for the presence of the cytokines IL-2, TNF, IFN-γ and IL-10 by enzyme-linked immunosorbent assay (ELISA). To determine whether Th1 or Th2 have a memory response against PvMSP1P-19 and PvDBPII protein antigen, PBMCs from subjects who had recovered from P. vivax infection 8-10 weeks prior to the study were obtained for lymphocyte proliferation assay. Cytokine-producing cells were analysed by flow cytometry. IL-2 was detected at high levels in lymphocyte cultures from acutely infected P. vivax patients upon PvMSP1P-19 stimulation. Analysis of the Th1 or Th2 memory response in PBMC cultures from subjects who had recovered from P. vivax infection showed significantly elevated levels of PvMSP1P-19 and PvDBPII-specific IFN-γ-producing cells (P  response of IFN-γ-producing cells in PvMSP1P stimulation was fourfold greater in recovered subjects than that in acute-infection patients. CD4(+) T cells were the major cell phenotype involved in the response to PvMSP1P-19 and PvDBPII antigen. PvMSP1P-19 strongly induces a specific cellular immune response for protection against P. vivax compared with PvDBPII as the antigen induces activation of IFN

  19. Spontaneous immune responses against glioma-associated antigens in a long term survivor with malignant glioma

    Directory of Open Access Journals (Sweden)

    Fujita Mitsugu

    2007-12-01

    Full Text Available Abstract Background In patients with high grade glioma, little is known regarding existence of naturally occurring adaptive T cell reactivity against glioma-associated antigens (GAAs. In this report, we characterized GAA-specific CD8+ T cells and innate immune cells in a patient who has survived with anaplastic astrocytoma (AA for over 12 years without recurrence. Methods Peripheral blood mononuclear cells (PBMCs derived from the long term survivor with AA were evaluated for the frequency, cytotoxic T lymphocyte (CTL activity and differentiation status of CD8+ cells recognizing GAA-derived epitopes as well as relative numbers of other immune cell subsets. This patient's AA tissue was evaluated for expression of two GAAs EphA2 and interleukin-13 receptor α2 subunit (IL-13Rα2 by immunohistochemistry. Results The patient's tumor expressed both EphA2 and IL-13Rα2, and in vitro stimulated PBMC demonstrated superior EphA2883–891 and IL-13Rα2345–353-specific CTL reactivity compared to PBMC samples from two other patients with progressing malignant glioma. Unstimulated EphA2883–891-reactive CD8+ T cells contained high numbers of CD45RA-/CCR7- late effector and CD45RA-/CCR7+ central memory cells. Among other leukocyte subsets, elevated numbers of NK-T cells were found. Conclusion To our knowledge, the current study is one of the first demonstrating the presence of antigen-experienced, GAA-reactive CD8+ T cells in a patient who has survived with AA for over 12 years without recurrence. Further studies are warranted to determine whether the status of GAA-reactive CD8+ T cells dictates survival of patients and/or response to therapeutic vaccines.

  20. Heterologous expression of carcinoembryonic antigen in Lactococcus lactis via LcsB-mediated surface displaying system for oral vaccine development.

    Science.gov (United States)

    Zhang, Xiaowei; Hu, Shumin; Du, Xue; Li, Tiejun; Han, Lanlan; Kong, Jian

    2016-12-01

    Carcinoembryonic antigen (CEA) is an attractive target for immunotherapy because it is expressed minimally in normal tissue, but is overexpressed in a wide variety of malignant epithelial tissues. Lactic acid bacteria (LABs), widely used in food processes, are attractive candidates for oral vaccination. Thus, we examined whether LABs could be used as a live vaccine vector to deliver CEA antigen. CEA was cloned into an Escherichia coli/Lactococcus lactis shuttle vector pSEC:LEISS under the control of a nisin promoter. For displaying the CEA on the cell surface of the L. lactis strain, the anchor motif LcsB from the S-layer protein of Lactobacillus crispatus was fused with CEA. Intracellular and cell surface expression of the CEA-LcsB fusion was confirmed by western blot analysis. Significantly higher levels of CEA-specific secretory immunoglobulin A in the sera of mice were observed upon oral administration of strain cultures containing the CEA-LcsB fused protein. In addition, the CEA-LcsB antigen group showed a higher spleen index compared to the CEA antigen alone or negative control, demonstrating that surface-displayed CEA antigen could induce a higher immune response. These results provided the first evidence for displaying CEA antigen on the cell surfaces of LABs as oral vaccines against cancer or infectious diseases. Copyright © 2014. Published by Elsevier B.V.

  1. Analysis of Structures and Epitopes of Surface Antigen Glycoproteins Expressed in Bradyzoites of Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Hua Cong

    2013-01-01

    Full Text Available Toxoplasma gondii is a protozoan parasite capable of infecting humans and animals. Surface antigen glycoproteins, SAG2C, -2D, -2X, and -2Y, are expressed on the surface of bradyzoites. These antigens have been shown to protect bradyzoites against immune responses during chronic infections. We studied structures of SAG2C, -2D, -2X, and -2Y proteins using bioinformatics methods. The protein sequence alignment was performed by T-Coffee method. Secondary structural and functional domains were predicted using software PSIPRED v3.0 and SMART software, and 3D models of proteins were constructed and compared using the I-TASSER server, VMD, and SWISS-spdbv. Our results showed that SAG2C, -2D, -2X, and -2Y are highly homologous proteins. They share the same conserved peptides and HLA-I restricted epitopes. The similarity in structure and domains indicated putative common functions that might stimulate similar immune response in hosts. The conserved peptides and HLA-restricted epitopes could provide important insights on vaccine study and the diagnosis of this disease.

  2. Postvaccination seroconversion against the surface antigen of Hepatitis B virus, in nursing students

    Directory of Open Access Journals (Sweden)

    Gladys Amanda Mera-Urbano

    2013-09-01

    Full Text Available Objective: To determine the status of seroconversion after vaccination against the surface antigen of hepatitis B virus in nursing students, University of Cauca. Methods: Cross sectional study in students of V and VI semester. The sample was taken from 37 students, 15 of V and 22 of VI semester. The instrument used was a survey that included 11 questions of multiple selections. Records for weight, height and laboratory results were collected; blood samples for antibody titers were performed with informed consent. The data were tabulated and analyzed using SPSS, version 17.0. Results: 89.2% of students had levels of antibodies to the surface antigen. This value was greater than 10 mUI/ml, considered by the scientific community as a protector value of Hepatitis B. 10.8% of had lesser values. Regarding vaccination scheme, 24% had a dose, 19% two, 48% three and 8% had a one dose. The population with 3 doses and reinforcement seroconverted by 100%. Conclusion: This study demonstrated failings in the scheme of vaccination of the students of nursing and that 10.8 % presented lower values than 10 mIU/ml. It is necessary to apply the institutional rules with more strength as a preventive measure for hepatitis B.

  3. Recombinant forms of Leishmania amazonensis excreted/secreted promastigote surface antigen (PSA) induce protective immune responses in dogs

    OpenAIRE

    Petitdidier, Elodie; Pagniez, Julie; Papierok, Gérard; Vincendeau, Philippe; Lemesre, Jean-Loup; Bras-Gonçalves, Rachel

    2016-01-01

    International audience; Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES) antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA), fr...

  4. Proteasomal targeting and minigene repetition improve cell-surface presentation of a transfected, modified melanoma tumour antigen

    DEFF Research Database (Denmark)

    Rasmussen, A B; Zocca, M-B; Bonefeld, C M

    2004-01-01

    on the density of specific major histocompatibility complex-peptide complexes on the surface of the antigen-presenting cell. In this study, we explored the cell-surface presentation of a substituted MART-1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared...

  5. Antigen processing of glycoconjugate vaccines; the polysaccharide portion of the pneumococcal CRM(197) conjugate vaccine co-localizes with MHC II on the antigen processing cell surface.

    Science.gov (United States)

    Lai, Zengzu; Schreiber, John R

    2009-05-21

    Pneumococcal (Pn) polysaccharides (PS) are T-independent (TI) antigens and do not induce immunological memory or antibodies in infants. Conjugation of PnPS to the carrier protein CRM(197) induces PS-specific antibody in infants, and memory similar to T-dependent (Td) antigens. Conjugates have improved immunogenicity via antigen processing and presentation of carrier protein with MHC II and recruitment of T cell help, but the fate of the PS attached to the carrier is unknown. To determine the location of the PS component of PnPS-CRM(197) in the APC, we separately labeled PS and protein and tracked their location. The PS of types 14-CRM(197) and 19F-CRM(197) was specifically labeled by Alexa Fluor 594 hydrazide (red). The CRM(197) was separately labeled red in a reaction that did not label PS. Labeled antigens were incubated with APC which were fixed, permeabilized and incubated with anti-MHC II antibody labeled green by Alexa Fluor 488, followed by confocal microscopy. Labeled CRM(197) was presented on APC surface and co-localized with MHC II (yellow). Labeled unconjugated 14 or 19F PS did not go to the APC surface, but PS labeled 14-CRM(197) and 19F-CRM(197) was internalized and co-localized with MHC II. Monoclonal antibody to type 14 PS bound to intracellular type 14 PS and PS-CRM(197). Brefeldin A and chloroquine blocked both CRM(197) and PS labeled 14-CRM(197) and 19F-CRM(197) from co-localizing with MHC II. These data suggest that the PS component of the CRM(197) glycoconjugate enters the endosome, travels with CRM(197) peptides to the APC surface and co-localizes with MHC II.

  6. Longitudinal microarray analysis of cell surface antigens on peripheral blood mononuclear cells from HIV+ individuals on highly active antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Wang Bin

    2008-03-01

    Full Text Available Abstract Background The efficacy of highly active antiretroviral therapy (HAART determined by simultaneous monitoring over 100 cell-surface antigens overtime has not been attempted. We used an antibody microarray to analyze changes in the expression of 135 different cell-surface antigens overtime on PBMC from HIV+ patients on HAART. Two groups were chosen, one (n = 6 achieved sustainable response by maintaining below detectable plasma viremia and the other (n = 6 responded intermittently. Blood samples were collected over an average of 3 years and 5–8 time points were selected for microarray assay and statistical analysis. Results Significant trends over time were observed for the expression of 7 cell surface antigens (CD2, CD3epsilon, CD5, CD95, CD36, CD27 and CD28 for combined patient groups. Between groups, expression levels of 10 cell surface antigens (CD11a, CD29, CD38, CD45RO, CD52, CD56, CD57, CD62E, CD64 and CD33 were found to be differential. Expression levels of CD9, CD11a, CD27, CD28 and CD52, CD44, CD49d, CD49e, CD11c strongly correlated with CD4+ and CD8+ T cell counts, respectively. Conclusion Our findings not only detected markers that may have potential prognostic/diagnostic values in evaluating HAART efficacy, but also showed how density of cell surface antigens could be efficiently exploited in an array-like manner in relation to HAART and HIV-infection. The antigens identified in this study should be further investigated by other methods such as flow cytometry for confirmation as biological analysis of these antigens may help further clarify their role during HAART and HIV infection.

  7. Long-term treatment of pigs with low doses of monoclonal antibodies against porcine CD4 and CD8 antigens

    DEFF Research Database (Denmark)

    Lohse, Louise; Nielsen, Jens; Eriksen, Lis

    2006-01-01

    In vivo depletion of lymphocyte subsets allows investigation of the role of specific subsets in protective immunity. In the present study we evaluated the effects of long-term, low-dose treatment with murine monoclonal antibodies (mAbs) against porcine CD4 and CD8 surface antigens on lymphocyte....... Treatment with the anti-CD4 mAb almost completely eliminated the CD4(+) T-cell subset from the circulation after 2 weeks of therapy. This depletion persisted until the end of the experimental period 5 weeks after initiated therapy. Treatment with the anti-CD8 mAb was less effective, reducing the CD8(+) T......-cell subset in peripheral blood by approximately 50% of the initial level after 3 weeks of therapy. Further, the anti-CD8 mAb-treated pigs showed a parallel increase in the CD4(+) T-cell subset from day 7. Two-colour FCM analysis indicated that a shift in phenotype from single-positive CD4(+)/CD8(-) to double...

  8. Enhanced immunogenicity of DNA fusion vaccine encoding secreted hepatitis B surface antigen and chemokine RANTES

    International Nuclear Information System (INIS)

    Kim, Seung Jo; Suh, Dongchul; Park, Sang Eun; Park, Jeong-Sook; Byun, Hyang-Min; Lee, Chan; Lee, Sun Young; Kim, Inho; Oh, Yu-Kyoung

    2003-01-01

    To increase the potency of DNA vaccines, we constructed genetic fusion vaccines encoding antigen, secretion signal, and/or chemokine RANTES. The DNA vaccines encoding secreted hepatitis B surface antigen (HBsAg) were constructed by inserting HBsAg gene into an expression vector with an endoplasmic reticulum (ER)-targeting secretory signal sequence. The plasmid encoding secretory HBsAg (pER/HBs) was fused to cDNA of RANTES, generating pER/HBs/R. For comparison, HBsAg genes were cloned into pVAX1 vector with no signal sequence (pHBs), and further linked to the N-terminus of RANTES (pHBs/R). Immunofluorescence study showed the cytoplasmic localization of HBsAg protein expressed from pHBs and pHBs/R, but not from pER/HBs and pER/HBs/R at 48 h after transfection. In mice, RANTES-fused DNA vaccines more effectively elicited the levels of HBsAg-specific IgG antibodies than pHBs. All the DNA vaccines induced higher levels of IgG 2a rather than IgG 1 antibodies. Of RANTES-fused vaccines, pER/HBs/R encoding the secreted fusion protein revealed much higher humoral and CD8 + T cell-stimulating responses compared to pHBs/R. These results suggest that the immunogenicity of DNA vaccines could be enhanced by genetic fusion to a secretory signal peptide sequence and RANTES

  9. Liver Allograft Its Use in Chronic Active Hepatitis With Macronodular Cirrhosis, Hepatitis B Surface Antigen

    Science.gov (United States)

    Corman, Jarques L.; Putnam, Charles W.; Iwatsuki, Shunzaburo; Redeker, Allan G.; Porter, K. A.; Peters, Robert L.; Schröter, Gerhard; Starzl, Thomas E.

    2010-01-01

    A patient suffering from chronic active hepatitis with macronodular cirrhosis, positive for hepatitis B surface antigen (HB,Ag), was treated with an orthoiopic liver allograft. The HB, antigenemia, as measured with several precipltation tests and by complement fixation, became negative after transplantation and remained so for about 2½ months. During the interval, very low Iters of the antigen were detectable by, radioimmunoassay. At about three months after transplantation, she had an attack of acute hepatitis, at which time HB,Ag became detectable by all tests. She recovered, but progressive liver disease developed during the remaining 1½ years of her life. She died of disseminaled nocardiosis and candidiasis with deteriorating hepatic function. The homograft at autopsy, showed no evidence of rejection, but was the site of chronic active liver disease, although of a different pathologic pattern than that affecting her native liver. The differences in histology may reflect the influence of chronic Immunosuppression on the features of chronic active hepatitis. PMID:365134

  10. Salmonella regulates polyubiquitination and surface expression of MHC class II antigens.

    Science.gov (United States)

    Lapaque, Nicolas; Hutchinson, James L; Jones, Des C; Méresse, Stéphane; Holden, David W; Trowsdale, John; Kelly, Adrian P

    2009-08-18

    Salmonella typhimurium is a facultative pathogen capable of entering and replicating in both professional and non-professional antigen presenting cells. Control of infection requires MHC class II restricted CD4 T-helper cell responses. Here we show that Salmonella infection induced polyubiquitination of HLA-DR, a post-translational modification that led to removal of mature, peptide loaded, alphabeta dimers from the cell surface. Immature alphabetaIi complexes were unaffected. Surface expression of all class II isotypes, HLA-DP, -DQ, and -DR, was reduced in infected cells, but other cell-surface molecules that traffic through class II peptide loading compartments were unaffected. A Salmonella strain carrying a mutation in ssaV did not induce ubiquitination of class II, implicating Salmonella T3SS-2 effector proteins in the process. T3SS-2 effectors, with established or proposed roles in ubiquitination, were not required for class II down-regulation, suggesting that an additional T3SS-2 effector is involved in regulating MHC class II ubiquitination. Although recognized as a viral immune evasion strategy, here, we demonstrate that bacteria can control surface MHC expression through ubiquitination.

  11. Preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens and their use for bacterial detection.

    Science.gov (United States)

    Dykman, Lev A; Staroverov, Sergei A; Guliy, Olga I; Ignatov, Oleg V; Fomin, Alexander S; Vidyasheva, Irina V; Karavaeva, Olga A; Bunin, Viktor D; Burygin, Gennady L

    2012-01-01

    This article reports the first preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens by using a combinatorial phage library of sheep antibodies. The prepared phage antibodies were used for the first time for lipopolysaccharide and flagellin detection by dot assay, electro-optical analysis of cell suspensions, and transmission electron microscopy. Interaction of A. brasilense Sp245 with antilipopolysaccharide and antiflagellin phage-displayed miniantibodies caused the magnitude of the electro-optical signal to change considerably. The electro-optical results were in good agreement with the electron microscopic data. This is the first reported possibility of employing phage-displayed miniantibodies in bacterial detection aided by electro-optical analysis of cell suspensions.

  12. Identification of the Streptococcus pyogenes surface antigens recognised by pooled human immunoglobulin

    Science.gov (United States)

    Reglinski, Mark; Gierula, Magdalena; Lynskey, Nicola N.; Edwards, Robert J.; Sriskandan, Shiranee

    2015-01-01

    Immunity to common bacteria requires the generation of antibodies that promote opsonophagocytosis and neutralise toxins. Pooled human immunoglobulin is widely advocated as an adjunctive treatment for clinical Streptococcus pyogenes infection however, the protein targets of the reagent remain ill defined. Affinity purification of the anti-streptococcal antibodies present within pooled immunoglobulin resulted in the generation of an IgG preparation that promoted opsonophagocytic killing of S. pyogenes in vitro and provided passive immunity in vivo. Isolation of the streptococcal surface proteins recognised by pooled human immunoglobulin permitted identification and ranking of 94 protein antigens, ten of which were reproducibly identified across four contemporary invasive S. pyogenes serotypes (M1, M3, M12 and M89). The data provide novel insight into the action of pooled human immunoglobulin during invasive S. pyogenes infection, and demonstrate a potential route to enhance the efficacy of antibody based therapies. PMID:26508447

  13. A highly sensitive radioimmunoassay technique for subtyping the antibody to hepatitis B surface antigen

    International Nuclear Information System (INIS)

    Fang, C.T.; Nath, N.; Berberian, H.; Dodd, R.Y.

    1978-01-01

    A highly sensitive technique for determining the subtype specificity of antibody to hepatitis B surface antigen (anti-HBs) is described. Immunoadsorbent consisting of controlled pore glass coated with subtype specific HBsAg was used to remove homologous antibody from the test samples before testing them for residual antibody by a commercially available radioimmunoassay (RIA). A total of 73 anti-HBs-positive samples from asymptomatic blood donors were tested. In nearly 80% of these samples the subtype reactivity could be determined by this technique. Only 67% could be typed by conventional liquid phase absorption RIA and 22% by passive hemagglutination inhibition techniques. Among the samples with low anti-HBs titer, ad and ay subtypes were found with equal frequency; however, with the increase in anti-HBs titer, considerably higher proportion of ad specificity was detected. (Auth.)

  14. Malaria-induced acquisition of antibodies to Plasmodium falciparum variant surface antigens

    DEFF Research Database (Denmark)

    Ofori, Michael F; Dodoo, Daniel; Staalsoe, Trine

    2002-01-01

    In areas of intense Plasmodium falciparum transmission, protective immunity is acquired during childhood in parallel with acquisition of agglutinating antibodies to parasite-encoded variant surface antigens (VSA) expressed on parasitized red blood cells. In a semi-immune child in such an area......, clinical disease is caused mainly by parasites expressing VSA not recognized by preexisting VSA-specific antibodies in that child. Such malaria episodes are known to cause an increase in agglutinating antibodies specifically recognizing VSA expressed by the parasite isolate causing the illness, whereas...... antibody responses to other parasite isolates are relatively unaffected. However, the detailed kinetics of this VSA antibody acquisition are unknown and hence were the aim of this study. We show that P. falciparum malaria in Ghanaian children generally caused a rapid and sustained increase in variant...

  15. Long Term 1 Enhanced Surface Water Treatment Rule Documents

    Science.gov (United States)

    The Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR) builds on the requirements of the Surface Water Treatment Rule and specifies treatment requirements to address Cryptosporidium m and other microbial contaminants in public water systems.

  16. The Leishmania promastigote surface antigen 2 complex is differentially expressed during the parasite life cycle.

    Science.gov (United States)

    Handman, E; Osborn, A H; Symons, F; van Driel, R; Cappai, R

    1995-11-01

    The promastigote surface antigen 2 (PSA-2) complex comprises a family of antigenically similar polypeptides of M(r) 96,000, 80,000 and 50,000, anchored to the membrane with glycosylphosphatidylinositol. Although PSA-2 was initially detected only in promastigotes, Northern blot analysis indicated that mRNA transcripts are also present in amastigotes. Unlike the situation in promastigotes, where at least four major transcripts (2.6-5.3 kb) were detected, only one major (2.6 kb) and two minor transcripts were present in amastigotes. A cDNA clone encoding a member of the PSA-2 family expressed in amastigotes was isolated using DNA probes. The predicted protein sequence of M(r) 40,000 is distinct from promastigote sequences, but shows significant similarity to previously described members of the family from L major and L amazonensis. Antibodies to the carboxyl terminal sequence conserved in all L major PSA-2 studied to date, as well as antibodies affinity purified on the amastigote cDNA-derived polypeptide recognized a major M(r) 50,000 amastigote polypeptide. Immuno-electron microscopy localized both promastigote and amastigote PSA-2 to the cell surface. The expression of PSA-2 polypeptides during the transformation of amastigotes into promastigotes was ordered in a time-dependent manner, with the promastigote M(r) 80000 polypeptide appearing first, followed by the M(r) 96000 polypeptide. In contrast to the glycosylphosphatidylinositol anchor of promastigote PSA-2, which could be hydrolysed by phosphatidylinositol-specific phospholipase C, the amastigote form was resistant to this enzyme.

  17. A molecular analysis of viral persistence in surface antigen-negative chronic hepatitis B.

    Science.gov (United States)

    Kato, J; Hasegawa, K; Torii, N; Yamauchi, K; Hayashi, N

    1996-03-01

    To identify the mechanisms of viral persistence in patients with chronic hepatitis B after the acquisition of anti-hepatitis B surface antigen antibodies (antiHBs), we serially analyzed the nucleotide sequence of the envelope region in a cohort of infected patients. Four patients with histological diagnoses of chronic hepatitis B who had at least 5 years of observance by our hospital staff were studied. All but one showed normalization of serum alanine aminotransferase (ALT) concentration after clearance of the hepatitis B surface of antigen (HBsAg) and the appearance of anti-HBs. Hepatitis B virus (HBV) DNA was still detectable by polymerase chain reaction (PCR) amplification assay in serum specimens from two patients, even in the presence of circulating anti-HBs. The envelope gene was amplified by PCR in serum samples obtained both before and after seroconversion, and direct cycle sequencing of the PCR products was performed. A mutation resulting in a premature stop codon was found in the pre-S1 region of one patient just prior to clearance of HBsAg. Two years later, the stop codon was converted to a leucine codon and three mutations developed in the "a" loop. In the other patient, 16 amino acids had been deleted between amino acids 8 and 23 in the pre-S2 region before clearance of HBsAg. After the appearance of circulating anti-HBs, the pre-S2 gene reverted to the wild type but three additional mutations appeared inside the "a" loop. These results suggest that HBV mutates when HBsAg is cleared, which may contribute to viral persistence due to an evasion of the host immune surveillance.

  18. Antibodies to variable Plasmodium falciparum-infected erythrocyte surface antigens are associated with protection from novel malaria infections

    DEFF Research Database (Denmark)

    Giha, H A; Staalsoe, T; Dodoo, D

    2000-01-01

    is maintained at low densities. Here, we test the hypothesis that the presence or absence of antibodies against variant antigens on the surface of P. falciparum-infected erythrocytes protect individuals against some infectious challenges and render them susceptible to others. Plasma collected in Daraweesh...... susceptible and protected individuals. Together, the results indicate that pre-existing anti-PfEMP1 antibodies can reduce the risk of contracting clinical malaria when challenged by novel parasite clones expressing homologous, but not heterologous variable surface antigens. The results also confirm...

  19. Leishmania-specific surface antigens show sub-genus sequence variation and immune recognition.

    Directory of Open Access Journals (Sweden)

    Daniel P Depledge

    2010-09-01

    Full Text Available A family of hydrophilic acylated surface (HASP proteins, containing extensive and variant amino acid repeats, is expressed at the plasma membrane in infective extracellular (metacyclic and intracellular (amastigote stages of Old World Leishmania species. While HASPs are antigenic in the host and can induce protective immune responses, the biological functions of these Leishmania-specific proteins remain unresolved. Previous genome analysis has suggested that parasites of the sub-genus Leishmania (Viannia have lost HASP genes from their genomes.We have used molecular and cellular methods to analyse HASP expression in New World Leishmania mexicana complex species and show that, unlike in L. major, these proteins are expressed predominantly following differentiation into amastigotes within macrophages. Further genome analysis has revealed that the L. (Viannia species, L. (V. braziliensis, does express HASP-like proteins of low amino acid similarity but with similar biochemical characteristics, from genes present on a region of chromosome 23 that is syntenic with the HASP/SHERP locus in Old World Leishmania species and the L. (L. mexicana complex. A related gene is also present in Leptomonas seymouri and this may represent the ancestral copy of these Leishmania-genus specific sequences. The L. braziliensis HASP-like proteins (named the orthologous (o HASPs are predominantly expressed on the plasma membrane in amastigotes and are recognised by immune sera taken from 4 out of 6 leishmaniasis patients tested in an endemic region of Brazil. Analysis of the repetitive domains of the oHASPs has shown considerable genetic variation in parasite isolates taken from the same patients, suggesting that antigenic change may play a role in immune recognition of this protein family.These findings confirm that antigenic hydrophilic acylated proteins are expressed from genes in the same chromosomal region in species across the genus Leishmania. These proteins are

  20. Source Term Model for Fine Particle Resuspension from Indoor Surfaces

    National Research Council Canada - National Science Library

    Kim, Yoojeong; Gidwani, Ashok; Sippola, Mark; Sohn, Chang W

    2008-01-01

    This Phase I effort developed a source term model for particle resuspension from indoor surfaces to be used as a source term boundary condition for CFD simulation of particle transport and dispersion in a building...

  1. IgM response to a human Pneumocystis carinii surface antigen in HIV-infected patients with pulmonary symptoms

    DEFF Research Database (Denmark)

    Lundgren, Bettina; Kovacs, J A; Mathiesen, Lars Reinhardt

    1993-01-01

    We have developed an ELISA to detect IgM antibodies to a major human Pneumocystis carinii surface antigen (gp95), and investigated the IgM response in 128 HIV-infected patients who underwent bronchoscopy for evaluation of pulmonary symptoms. Only 5 (4%) patients had IgM antibodies to P. carinii gp...... human P. carinii surface antigen. The increase in IgM response during the course of PCP observed in 3 patients suggests either reinfection with a new strain, or antigenic drift of an already acquired strain of P. carinii.......95. Four of the 5 patients with IgM antibodies also had IgG antibodies to gp95 and microbiologically proven P. carinii pneumonia (PCP). In 76/128 patients for whom serial samples were available, changes in antibody response were determined. In 3 patients we demonstrated an increase in IgM antibody...

  2. Baseline hepatitis B surface antigen quantitation can predict virologic response in entecavir-treated chronic hepatitis B patients.

    Science.gov (United States)

    Wang, Chia-Chi; Tseng, Tai-Chung; Wang, Pin-Chao; Lin, Hans Hsienhong; Kao, Jia-Horng

    2014-11-01

    Several anti-viral drugs are approved for the treatment of hepatitis B virus (HBV) infection. However, whether quantitative hepatitis B surface antigen (qHBsAg) can predict the therapeutic response during long-term entecavir treatment remains unclear. Fifty-five chronic hepatitis B (CHB) patients who received entecavir for more than 2 years were enrolled. The serum qHBsAg level was measured by HBsAg II quant immunoassay. A significant decline in the qHBsAg level was defined as > 1 log reduction from baseline to 6 months of entecavir treatment. Of the 55 patients (41 males and 14 females with a mean age of 48.3 ± 11.4 years), 23 patients were positive for hepatitis B e antigen (HBeAg). The median treatment period was 34 months, and ranged from 26 months to 43 months. A total of 288 serum samples were used to determine the qHBsAg levels. At year 3 of entecavir therapy, one (1.8%) patient had HBsAg seroclearance. A high qHBsAg level was defined as greater than 10,000 IU/mL. Patients with a high baseline qHBsAg level had a lower rate of virologic response at year 1 (37.5% vs. 89.7%, p response in all patients. The baseline serum qHBsAg level can predict virologic response in entecavir-treated CHB patients. However, a significant decline in the qHBsAg level cannot predict serologic or virologic response of entecavir treatment. Copyright © 2013. Published by Elsevier B.V.

  3. Clay Nanoparticles Elicit Long-Term Immune Responses by Forming Biodegradable Depots for Sustained Antigen Stimulation.

    Science.gov (United States)

    Chen, Weiyu; Zuo, Huali; Li, Bei; Duan, Chengcheng; Rolfe, Barbara; Zhang, Bing; Mahony, Timothy J; Xu, Zhi Ping

    2018-04-14

    Nanomaterials have been widely tested as new generation vaccine adjuvants, but few evoke efficient immunoreactions. Clay nanoparticles, for example, layered double hydroxide (LDH) and hectorite (HEC) nanoparticles, have shown their potent adjuvanticity in generating effective and durable immune responses. However, the mechanism by which clay nanoadjuvants stimulate the immune system is not well understood. Here, it is demonstrated that LDH and HEC-antigen complexes form loose agglomerates in culture medium/serum. They also form nodules with loose structures in tissue after subcutaneous injection, where they act as a depot for up to 35 d. More importantly, clay nanoparticles actively and continuously recruit immune cells into the depot for up to one month, and stimulate stronger immune responses than FDA-approved adjuvants, Alum and QuilA. Sustained antigen release is also observed in clay nanoparticle depots, with 50-60% antigen released after 35 d. In contrast, Alum-antigen complexes show minimal antigen release from the depot. Importantly, LDH and HEC are more effective than QuilA and Alum in promoting memory T-cell proliferation. These findings suggest that both clay nanoadjuvants can serve as active vaccine platforms for sustained and potent immune responses. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. cDNA sequence analysis of a 29-kDa cysteine-rich surface antigen of pathogenic Entamoeba histolytica

    International Nuclear Information System (INIS)

    Torian, B.E.; Stroeher, V.L.; Stamm, W.E.; Flores, B.M.; Hagen, F.S.

    1990-01-01

    A λgt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate 22 monoclonal antibodies (mAbs) and a mouse polyclonal antiserum specific for the E. histolytica portion of the fusion protein. A 29-kDa protein was identified as a surface antigen when mAbs were used to immunoprecipitate the antigen from metabolically 35 S-labeled live trophozoites. The surface location of the antigen was corroborated by mAb immunoprecipitation of a 29-kDa protein from surface- 125 I-labeled whole trophozoites as well as by the reaction of mAbs with live trophozoites in an indirect immunofluorescence assay performed at 4 degree C. Immunoblotting with mAbs demonstrated that the antigen was present on four axenic isolates tested. mAbs recognized epitopes on the 29-kDa native antigen on some but not all clinical isolates tested

  5. cDNA sequence analysis of a 29-kDa cysteine-rich surface antigen of pathogenic Entamoeba histolytica

    Energy Technology Data Exchange (ETDEWEB)

    Torian, B.E.; Stroeher, V.L.; Stamm, W.E. (Univ. of Washington, Seattle (USA)); Flores, B.M. (Louisiana State Univ. Medical Center, New Orleans (USA)); Hagen, F.S. (Zymogenetics Incorporated, Seattle, WA (USA))

    1990-08-01

    A {lambda}gt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate 22 monoclonal antibodies (mAbs) and a mouse polyclonal antiserum specific for the E. histolytica portion of the fusion protein. A 29-kDa protein was identified as a surface antigen when mAbs were used to immunoprecipitate the antigen from metabolically {sup 35}S-labeled live trophozoites. The surface location of the antigen was corroborated by mAb immunoprecipitation of a 29-kDa protein from surface-{sup 125}I-labeled whole trophozoites as well as by the reaction of mAbs with live trophozoites in an indirect immunofluorescence assay performed at 4{degree}C. Immunoblotting with mAbs demonstrated that the antigen was present on four axenic isolates tested. mAbs recognized epitopes on the 29-kDa native antigen on some but not all clinical isolates tested.

  6. Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

    Directory of Open Access Journals (Sweden)

    Tam Yew

    2012-10-01

    Full Text Available Abstract Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg from Pichia pastoris expression cells were optimized using response surface methodology (RSM based on the central composite design (CCD. The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing.

  7. Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

    Science.gov (United States)

    2012-01-01

    Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg) from Pichia pastoris expression cells were optimized using response surface methodology (RSM) based on the central composite design (CCD). The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW) and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR) and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing. PMID:23039947

  8. Long-term in vivo provision of antigen-specific T cell immunity by programming hematopoietic stem cells

    Science.gov (United States)

    Yang, Lili; Baltimore, David

    2005-03-01

    A method to genetically program mouse hematopoietic stem cells to develop into functional CD8 or CD4 T cells of defined specificity in vivo is described. For this purpose, a bicistronic retroviral vector was engineered that efficiently delivers genes for both and chains of T cell receptor (TCR) to hematopoietic stem cells. When modified cell populations were used to reconstruct the hematopoietic lineages of recipient mice, significant percentages of antigen-specific CD8 or CD4 T cells were observed. These cells expressed normal surface markers and responded to peptide antigen stimulation by proliferation and cytokine production. Moreover, they could mature into memory cells after peptide stimulation. Using TCRs specific for a model tumor antigen, we found that the recipient mice were able to partially resist a challenge with tumor cells carrying the antigen. By combining cells modified with CD8- and CD4-specific TCRs, and boosting with dendritic cells pulsed with cognate peptides, complete suppression of tumor could be achieved and even tumors that had become established would regress and be eliminated after dendritic cell/peptide immunization. This methodology of "instructive immunotherapy" could be developed for controlling the growth of human tumors and attacking established pathogens.

  9. Antibodies to variant antigens on the surfaces of infected erythrocytes are associated with protection from malaria in Ghanaian children

    DEFF Research Database (Denmark)

    Dodoo, D; Staalsoe, T; Giha, H

    2001-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a variant antigen expressed on the surface of infected erythrocytes. Each parasite genome contains about 40 PfEMP1 genes, but only 1 PfEMP1 gene is expressed at a given time. PfEMP1 serves as a parasite-sequestering ligand to endoth...

  10. Induction of protective immunity to Theileria annulata using two major merozoite surface antigens presented by different delivery systems

    NARCIS (Netherlands)

    C. D'Oliveira; A. Feenstra; H.W. Vos (Helma); A.D.M.E. Osterhaus (Albert); B.R. Shiels; A.W.C.A. Cornelissen; F. Jongejan

    1997-01-01

    textabstractAllelic forms (Tams1-1 and Tams1-2) of the major merozoite surface antigen gene of Theileria annulata have recently been expressed in Escherichia coli and in Salmonella typhimurium aroA vaccine strain SL3261. To test the potential of subunit vaccines against T. annulata infection, we

  11. The promastigote surface antigen gene family of the Leishmania parasite : differential evolution by positive selection and recombination - art. no. 292

    OpenAIRE

    Devault, A.; Banuls, Anne-Laure

    2008-01-01

    Background: PSA (promastigote surface antigen) is one of the major classes of membrane proteins present at the surface of the parasitic protozoan Leishmania. While it harbours leucine rich repeats, which are suggestive of its involvement in parasite-to-host physical interactions, its exact role is largely unknown. Furthermore, the extent of diversity of this gene family, both in copy number and sequence has not been established. Results: From the newly available complete genome sequences of L...

  12. A method for visualizing surface-exposed and internal PfEMP1 adhesion antigens in Plasmodium falciparum infected erythrocytes

    DEFF Research Database (Denmark)

    Bengtsson, Dominique; Sowa, Kordai M; Salanti, Ali

    2008-01-01

    -ionic detergent to permit access of antibodies to internal parasite antigens. Differentiation between surface and internal antigens is achieved using antibodies labelled with different fluorochromes and confocal microscopy RESULTS: Surface exposed PfEMP1 is first detectable by antibodies at the trophozoite stage...

  13. Hepatitis B Surface Antigen Seroprevalence among Children in Papua New Guinea, 2012–2013

    Science.gov (United States)

    Kitau, Russel; Sankar Datta, Siddhartha; Patel, Minal K.; Hennessey, Karen; Wannemuehler, Kathleen; Sui, Gerard; Lagani, William

    2015-01-01

    Approximately 8% of the population in Papua New Guinea (PNG) has chronic hepatitis B virus (HBV) infection. To decrease the burden of chronic HBV infection, a national 3-dose infant hepatitis B vaccination program was implemented starting in 1989, with a birth dose (BD) added to the schedule in 1992. To assess the impact of the hepatitis B vaccination program, we conducted a serosurvey among children born after vaccine introduction. During 2012–2013, a cross-sectional stratified four-stage cluster survey was conducted to estimate hepatitis B surface antigen (HBsAg) prevalence among children 4–6 years of age. We collected demographic data, vaccination history, and tested children for HBsAg. Of 2,133 participants, 2,130 children had vaccination data by either card or recall: 28% received a BD; 81% received ≥ 3 vaccine doses. Of 2,109 children providing a blood sample, 60 (2.3%) tested positive for HBsAg. This is the largest, most geographically diverse survey of hepatitis B vaccination and HBsAg seroprevalence done in PNG. Progress has been made in PNG toward the Western Pacific Regional goal to reduce the prevalence of chronic HBV infection to < 1% by 2017 among 5-year-old children. Vaccination efforts should be strengthened, including increasing BD coverage and completing the 3-dose series. PMID:25582692

  14. Sensitive prostate specific antigen quantification using dihydrolipoic acid surface-functionalized phosphorescent quantum dots.

    Science.gov (United States)

    García-Cortés, Marta; Fernández-Argüelles, María Teresa; Costa-Fernández, José M; Sanz-Medel, Alfredo

    2017-09-22

    Herein, high-quality Mn-doped ZnS quantum dots (QDs) have been synthesized using a facile approach directly in aqueous media. The surface of the obtained QDs was further modified by cap-exchange of the native cysteine shell with dihydrolipoic acid (DHLA) ligands resulting in nanocrystals with high water-stability having an intense phosphorescent signal. Covalent bioconjugation of the DHLA-coated nanoparticles with an anti-IgG antibody was then carried out. Interestingly the QD immunoprobe (QD-labelled antibodies) maintained an intense phosphorescence emission, without any significant spectral-shift (as compared to the free QDs). Coupling of an asymmetric flow field flow fractionation technique to an elemental mass spectrometry detection enabled the accurate determination of the efficiency of the bioconjugation reaction. The obtained nanoparticle-antibody bioconjugate was then applied to develop a quantitative sandwich-type phosphorescent immunoassay for Prostate Specific Antigen (PSA), and a limit of detection (LOD) of 17 pg mL -1 of PSA was achieved and allow to quantify such biomarker in samples within clinically relevant levels. Finally, the assay was validated for the quantification of PSA in the cellular media of prostate cancer cells. Obtained results proved the robustness of the proposed immunoassay based on long-lived phosphorescence measurements against eventual photoluminescent interferences significantly affecting the conventional short-lived fluorescence detection. Copyright © 2017. Published by Elsevier B.V.

  15. Increased parasite surface antigen-2 expression in clinical isolates of Leishmania donovani augments antimony resistance.

    Science.gov (United States)

    Bhandari, Vasundhra; Kumar, Dhiraj; Verma, Sandeep; Srividya, Gurumurthy; Negi, Narendra Singh; Singh, Ruchi; Salotra, Poonam

    2013-11-01

    Resistance to sodium antimony gluconate (SAG) is a major cause of therapeutic failure in a large proportion of visceral leishmaniasis (VL) cases. Determinants of SAG resistance have been widely studied; however, the mechanism operating in clinical isolates is poorly understood. In the present study, expression of parasite surface antigen-2 (PSA-2) gene was studied in clinical isolates of Leishmania donovani comprising of antimony resistant (n=10) and sensitive (n=4) parasites. The expression of PSA-2 gene was found to be consistently high in SAG resistant clinical isolates (≥1.5-fold) at both transcript and protein level. Further, over-expression of PSA-2 in L. donovani isolates (LdPSA-2(++)) resulted in conversion of SAG sensitive phenotype to resistant. The LdPSA-2(++) parasites showed significantly decreased susceptibility towards SAG (>12-fold), amphotericin B (>4-fold) and miltefosine (>2.5-fold). Marked decrease in antimony accumulation and enhanced tolerance towards complement mediated lysis was evident in LdPSA-2(++) parasites. The study established the role of PSA-2 gene in SAG resistance and its potential as a biomarker to distinguish resistant and sensitive clinical isolates of L. donovani. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Long-term Prostate-specific Antigen Velocity in Improved Classification of Prostate Cancer Risk and Mortality

    DEFF Research Database (Denmark)

    Ørsted, David Dynnes; Bojesen, Stig E; Kamstrup, Pia R

    2013-01-01

    BACKGROUND: It remains unclear whether adding long-term prostate-specific antigen velocity (PSAV) to baseline PSA values improves classification of prostate cancer (PCa) risk and mortality in the general population. OBJECTIVE: To determine whether long-term PSAV improves classification of PCa risk...... and mortality in the general population. DESIGN, SETTING, AND PARTICIPANTS: We studied 503 men aged 30-80 yr, with and without PCa, who had repeated PSA measurements over 20 yr and up to 28 yr before PCa diagnosis. These were selected from among 7455 men in the Copenhagen City Heart Study, a prospective...... classification was assessed using the net reclassification index (NRI). RESULTS: Age-adjusted hazard ratios for PCa risk and mortality were 2.7-5.3 and 2.3-3.4, respectively, for long-term PSAV when added to models already including baseline PSA values. For PCa risk and mortality, adding long-term PSAV to models...

  17. Ultraviolet radiation (UVR) induces cell-surface Ro/SSA antigen expression by human keratinocytes in vitro: a possible mechanism for the UVR induction of cutaneous lupus lesions

    International Nuclear Information System (INIS)

    Jones, S.K.

    1992-01-01

    Antinuclear antibodies are useful markers of connective tissue disease. In this study, UVB but not UVA induced the expression of Ro/SSA antigen on keratinocyte surfaces in vitro. This expression was also found with the extractable nuclear antigens RnP and Sm, but not with single or double-stranded DNA. The expression was prevented by blocking protein synthesis, suggesting that it was an active process. The results suggest that UVB exposure may result in the expression of Ro/SSA antigen on the surfaces of basal keratinocytes in vivo. This antigen could then bind circulating antibody leading to the cutaneous lesions in neonatal and subacute cutaneous lupus erythematosus. (Author)

  18. Hepatitis B surface antigen variants in voluntary blood donors in Nanjing, China

    Directory of Open Access Journals (Sweden)

    Yong-lin Yang

    2012-04-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is still one of the serious infectious risks for the blood transfusion safety in China. One plausible reason is the emergence of the variants in the major antigenic alpha determinant within the major hydrophilic region (MHR of hepatitis B surface antigen (HBsAg, which have been assumed to evade the immune surveillance and pose a challenge to the disease diagnosis. It is well documented that some commercial ELISA kits could detect the wild-type but not the mutant viruses. The high prevalence of HBV in China also impaired the application of nucleic acid testing (NAT in the improvement of blood security. Molecular epidemiological study of HBsAg variations in China is still limited. This study was designed to identify the prevalence of mutations in the HBsAg in voluntary blood donors in Nanjing, China. Methods A total of 20,326 blood units were enrolled in this study, 39 donors were positive for HBV S gene in the nested-PCR. Mutations in the major hydrophilic region (MHR; aa 99-169 were identified by direct sequencing of S region. Results Among of 20,326 blood units in the Red Cross Transfusion Center of Nanjing from October 2008 to April 2009, 296 samples (1.46%, 296/20,326 were HBsAg positive in the 2 successive rounds of the ELISA test. In these HBsAg positive units, HBV S gene could be successfully amplified from 39 donors (13.18%, 39/296 in the nested-PCR. Sequence analysis revealed that 32 strains (82.1%, 32/39 belong to genotype B, 7 strains (17.9%, 7/39 to genotype C. Besides well known G145R, widely dispersed variations in the MHR of S region, were observed in 20 samples of all the strains sequenced. Conclusions HBV/B and HBV/C are dominant in Nanjing, China. The mutations in the MHR of HBsAg associated with disease diagnosis are common.

  19. Performance evaluation of new automated hepatitis B viral markers in the clinical laboratory: two quantitative hepatitis B surface antigen assays and an HBV core-related antigen assay.

    Science.gov (United States)

    Park, Yongjung; Hong, Duck Jin; Shin, Saeam; Cho, Yonggeun; Kim, Hyon-Suk

    2012-05-01

    We evaluated quantitative hepatitis B surface antigen (qHBsAg) assays and a hepatitis B virus (HBV) core-related antigen (HBcrAg) assay. A total of 529 serum samples from patients with hepatitis B were tested. HBsAg levels were determined by using the Elecsys (Roche Diagnostics, Indianapolis, IN) and Architect (Abbott Laboratories, Abbott Park, IL) qHBsAg assays. HBcrAg was measured by using Lumipulse HBcrAg assay (Fujirebio, Tokyo, Japan). Serum aminotransferases and HBV DNA were respectively quantified by using the Hitachi 7600 analyzer (Hitachi High-Technologies, Tokyo, Japan) and the Cobas AmpliPrep/Cobas TaqMan test (Roche). Precision of the qHBsAg and HBcrAg assays was assessed, and linearity of the qHBsAg assays was verified. All assays showed good precision performance with coefficients of variation between 4.5% and 5.3% except for some levels. Both qHBsAg assays showed linearity from 0.1 to 12,000.0 IU/mL and correlated well (r = 0.9934). HBsAg levels correlated with HBV DNA (r = 0.3373) and with HBcrAg (r = 0.5164), and HBcrAg also correlated with HBV DNA (r = 0.5198; P < .0001). This observation could provide impetus for further research to elucidate the clinical usefulness of the qHBsAg and HBcrAg assays.

  20. Serological versus molecular typing of surface-associated immune evading polysaccharide antigens-based phenotypes of Staphylococcus aureus.

    Science.gov (United States)

    Waryah, Charlene B; Gogoi-Tiwari, Jully; Wells, Kelsi; Costantino, Paul; Al-Salami, Hani; Sunagar, Raju; Isloor, Shrikrishna; Hegde, Nagendra; Richmond, Peter; Mukkur, Trilochan

    2014-11-01

    The aim of this study was to compare the performance of serological versus molecular typing methods to detect capsular polysaccharide (CP) and surface-associated polysaccharide antigen 336 phenotypes of Staphylococcus aureus isolates. Molecular typing of CP types 1, 5 and 8 was carried out using PCR, whereas serological typing of CP1, 2, 5, 8 and antigen 336 was carried out by slide agglutination using specific antisera. By genotyping, 14/31 strains were CP8 positive, 12/31 strains were CP5 and the remaining 6/31 isolates were non-typable (NT). One isolate was positive for both CP5 and CP8 by PCR, but was confirmed as CP8 type serologically. Detection of CP2 and type 336 by PCR was not possible because specific primers were either not available or non-specific. Using serotyping, 14/31 strains were CP8 positive, 11/31 CP5 positive and 2/31 positive for antigen 336. The remaining four S. aureus isolates were serologically NT. However, three of four NT and two 336-positive S. aureus isolates were encapsulated as determined by light microscopy after capsular staining. This discovery was surprising and warrants further investigations on the identification and characterization of additional capsular phenotypes prevalent among S. aureus clinical isolates. It was concluded that serological typing was a better method than molecular typing for use in epidemiological investigations based upon the distribution of surface-associated polysaccharide antigens-based phenotypes. © 2014 The Authors.

  1. A novel merozoite surface antigen of Plasmodium falciparum (MSP-3 identified by cellular-antibody cooperative mechanism antigenicity and biological activity of antibodies

    Directory of Open Access Journals (Sweden)

    Claude Oeuvray

    1994-01-01

    Full Text Available We report the identification of a 48kDa antigen targeted by antibodies which inhibit Plasmodium falciparum in vitro growth by cooperation with blood monocytes in an ADCI assay correlated to the naturally acquired protection. This protein is located on the surface of the merozoite stage of P. falciparum, and is detectable in all isolates tested. Epidemiological studies demonstrated that peptides derived from the amino acid sequence of MSP-3 contain potent B and T-cell epitopes recognized by a majority of individuals living in endemic areas. Moreover human antibodies either purified on the recombinant protein, or on the synthetic peptide MSP-3b, as well as antibodies raised in mice, were all found to promote parasite killing mediated by monocytes.

  2. Serological responses to Cryptosporidium antigens in inhabitants of Hungary using conventionally filtered surface water and riverbank filtered drinking water.

    Science.gov (United States)

    Farkas, K; Plutzer, J; Moltchanova, E; Török, A; Varró, M J; Domokos, K; Frost, F; Hunter, P R

    2015-10-01

    In this study the putative protective seroprevalence (PPS) of IgG antibodies to the 27-kDa and 15/17-kDa Cryptosporidium antigens in sera of healthy participants who were and were not exposed to Cryptosporidium oocysts via surface water-derived drinking water was compared. The participants completed a questionnaire regarding risk factors that have been shown to be associated with infection. The PPS was significantly greater (49-61%) in settlements where the drinking water originated from surface water, than in the control city where riverbank filtration was used (21% and 23%). Logistic regression analysis on the risk factors showed an association between bathing/swimming in outdoor pools and antibody responses to the 15/17-kDa antigen complex. Hence the elevated responses were most likely due to the use of contaminated water. Results indicate that waterborne Cryptosporidium infections occur more frequently than reported but may derive from multiple sources.

  3. Prevalence of Hepatitis B surface antigen in children with sickle cell anemia

    Directory of Open Access Journals (Sweden)

    Baba Jibrin

    2014-01-01

    Full Text Available Background: Hepatitis B virus is known to be endemic in Africa. The seroepidemiological studies of HBV have shown that infection commonly occurs in childhood in Africa resulting in an increased tendency to chronicity. This cross-sectional study was undertaken to determine the seroprevalence of hepatitis B surface antigen among pediatric patients with homozygous hemoglobin S. Materials and Methods: Three hundred sickle cell anemia children aged 6 months-15 years (both in steady state and in crises attending the SCA clinic and on admission in emergency pediatrics unit and pediatrics medical ward, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria, were screened for hepatitis B infection using HBsAg as marker of infection. The sensitive enzyme linked immunosorbent assay method was used for detection of the marker. Three hundred children with minor illness attending pediatrics outpatient department and on admission in EPU/PMW for various treatment in the same hospital served as gender- and age-marched controls cohorts. Results: The sero-prevalence of HBsAg seropositivity for hepatitis B virus infection among SCA children was 17.3% (52/300 compared to 10.7% (32/300 of the control (P = 0.0875. The peak prevalence age group for HBV infection among SCA children was in the age group 1.1-5.0 years (6% compared to 10.1-15.0 years (4.7% in the control. Risk factors for HBV infection such as blood transfusion, traditional scarification/circumcision/uvulectomy, and tattooing did not significantly affect the prevalence of HBV infection in both SCA children and controls. Conclusion: Hepatitis B infection is common in Sokoto. The need for strict adherence to HBV immunization and further community-based studies on the risk factors are recommended.

  4. PRISM hepatitis B surface antigen detection of hepatits B virus minipool nucleic acid testing yield samples.

    Science.gov (United States)

    Linauts, Sandy; Saldanha, John; Strong, D Michael

    2008-07-01

    Hepatitis B virus (HBV) residual risk has been estimated at 1:63,000-1:205,000 and introduction of more sensitive serological tests and nucleic acid testing (NAT) would reduce that risk. Sensitivity of the recently licensed Abbott PRISM hepatitis B surface antigen (HBsAg) CLIA and minipool (MP) HBV NAT has been described as comparable and thus the need for HBV NAT has not been compelling. In this study, eight samples identified as yield samples with MP HBV NAT were tested using the PRISM test. Seven samples were identified using the Roche COBAS AmpliScreen HBV test and one additional sample was obtained from the clinical trial for the Roche cobas TaqScreen MPX test. Each of these samples was reactive by MP HBV NAT and nonreactive for HBsAg using one of three licensed enzyme immunoassay (EIA) tests. After licensure of the PRISM HBsAg, aliquots were tested with this assay, and DNA quantitation and genotyping were repeated where sample volume permitted. Three samples (2000, 2300, and 61,000 copies/mL) produced reactive results with PRISM. Four samples with viral loads less than 300 copies per mL produced nonreactive results. One sample, originally quantitated at 37,000 copies per mL (but 3850 copies/mL in repeat testing) was also nonreactive by PRISM. Genotyping of this sample indicated a type C genotype with no mutations. Adding serological sensitivity of PRISM CLIA reduced the NAT yield from the original 1: 385,555 to 1:610,488. However, MP HBV NAT still provides additional sensitivity over CLIA, even for a donation with a viral load of almost 4000 copies per mL.

  5. Diversity of Babesia bovis merozoite surface antigen genes in the Philippines.

    Science.gov (United States)

    Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Ybanez, Adrian Patalinghug; Ybanez, Rochelle Haidee Daclan; Perez, Zandro Obligado; Guswanto, Azirwan; Igarashi, Ikuo; Yokoyama, Naoaki

    2014-02-01

    Babesia bovis is the causative agent of fatal babesiosis in cattle. In the present study, we investigated the genetic diversity of B. bovis among Philippine cattle, based on the genes that encode merozoite surface antigens (MSAs). Forty-one B. bovis-positive blood DNA samples from cattle were used to amplify the msa-1, msa-2b, and msa-2c genes. In phylogenetic analyses, the msa-1, msa-2b, and msa-2c gene sequences generated from Philippine B. bovis-positive DNA samples were found in six, three, and four different clades, respectively. All of the msa-1 and most of the msa-2b sequences were found in clades that were formed only by Philippine msa sequences in the respective phylograms. While all the msa-1 sequences from the Philippines showed similarity to those formed by Australian msa-1 sequences, the msa-2b sequences showed similarity to either Australian or Mexican msa-2b sequences. In contrast, msa-2c sequences from the Philippines were distributed across all the clades of the phylogram, although one clade was formed exclusively by Philippine msa-2c sequences. Similarities among the deduced amino acid sequences of MSA-1, MSA-2b, and MSA-2c from the Philippines were 62.2-100, 73.1-100, and 67.3-100%, respectively. The present findings demonstrate that B. bovis populations are genetically diverse in the Philippines. This information will provide a good foundation for the future design and implementation of improved immunological preventive methodologies against bovine babesiosis in the Philippines. The study has also generated a set of data that will be useful for futher understanding of the global genetic diversity of this important parasite. © 2013.

  6. Higher lifetime chance of spontaneous surface antigen loss in hepatitis B carriers with genotype C infection.

    Science.gov (United States)

    Tseng, T-C; Liu, C-J; Chen, C-L; Yang, W-T; Yang, H-C; Su, T-H; Wang, C-C; Kuo, S F-T; Liu, C-H; Chen, P-J; Chen, D-S; Kao, J-H

    2015-05-01

    Clearance of hepatitis B surface antigen (HBsAg) indicates clinical control of hepatitis B virus (HBV) infection. However, little is known about the impact of viral genomic variations on HBsAg loss. We explored the association between viral genomic factors and HBsAg loss in 2121HBeAg-negative patients. HBV pre-core stop codon (1896) and basal core promoter (BCP) (1762/1764) sequences were determined in patients with HBV DNA ≥200 IU/mL (N = 1693). The effect of HBV genotype on HBsAg loss was further validated in the whole cohort of 3445 HBsAg carriers. The cumulative lifetime (age 28-75 years) incidence of HBsAg loss was 50.4% in 2121 HBeAg-negative patients. We found that genotype C, but not pre-core stop codon or BCP mutants, was associated with HBsAg loss. Compared to genotype B patients, genotype C patients had higher lifetime chance of HBsAg loss, with hazard ratio of 1.8 (95% confidence interval: 1.4-2.4). Multivariable analysis showed that male sex, elevated ALT levels, lower serum HBV DNA and HBsAg levels, and genotype C infection were associated with higher chance of HBsAg loss independently. We then performed sensitivity analysis, which re-included HBeAg-positive, cirrhotic and treatment-experienced patients, and confirmed the robustness of our results in 3445 HBsAg carriers. Genotype C infection, compared to genotype B, is associated with a higher lifetime chance of HBsAg loss in Asian HBV carriers. © 2015 John Wiley & Sons Ltd.

  7. An overview of serum prostatic surface antigen cut points for recommendation of prostatic biopsy.

    Science.gov (United States)

    Patwardhan, Sujata K; Patil, Bhushan P; Shelke, Umesh Ravikant; Singh, Abhishek G

    2018-01-01

    Patients in India frequently present with prostatic surface antigen (PSA) report and request for prostatic biopsy to rule out malignancy. With fear of harboring malignancy set in patient's mind, it becomes difficult to counsel them about absolute indications and need of biopsy. Whether serum PSA has same predictability in symptomatic patients in the Indian context for advising prostatic biopsy at same reference ranges as in western countries, remains to be answered. Symptomatic patients between 45 and 70 years of age presenting with either raised serum PSA (>4 ng/ml) reports or abnormal digital rectal examination (DRE) were considered as cases. Standard 12 core transrectal ultrasound-guided prostatic biopsy was done. Statistical analysis using optimal cut points, an R package was done to overview different PSA cut points for the recommendation of prostatic biopsy. A total of 534 patients were included. Mean age was 64 years. Malignancy was detected in total 77 patients (14.42%). Malignancy was identified in 3.59% (10/279) and 30% (63/210) patients at serum PSA ranges 4-10 ng/ml and serum PSA >10 ng/ml, respectively. Both, maximum sensitivity and specificity were found at PSA cut point 9.7 ng/ml. We evaluated these patients to identify the PSA cut point above which unnecessary biopsies will be avoided. We kept power of study maximum, i.e., 1 with confidence interval of 0.95. PSA value 9.7 ng/ml should be considered as the cut point above which prostatic biopsy should be done to avoid unnecessary biopsies. Unless accompanied by abnormal DRE finding at PSA range 4-10 ng/ml, morbidity of prostatic biopsy procedure can be avoided using this cut-point.

  8. Localization of immunodominant epitopes within the "a" determinant of hepatitis B surface antigen using monoclonal antibodies.

    Science.gov (United States)

    Golsaz-Shirazi, Forough; Mohammadi, Hamed; Amiri, Mohammad Mehdi; Khoshnoodi, Jalal; Kardar, Gholam Ali; Jeddi-Tehrani, Mahmood; Shokri, Fazel

    2016-10-01

    The common "a" determinant is the major immunodominant region of hepatitis B surface antigen (HBsAg) shared by all serotypes and genotypes of hepatitis B virus (HBV). Antibodies against this region are thought to confer protection against HBV and are essential for viral clearance. Mutations within the "a" determinant may lead to conformational changes in this region, which can affect the binding of neutralizing antibodies. There is an increasing concern about identification and control of mutant viruses which is possible by comprehensive structural investigation of the epitopes located within this region. Anti-HBs monoclonal antibodies (mAbs) against different epitopes of HBsAg are a promising tool to meet this goal. In the present study, 19 anti-HBs mAbs were employed to map epitopes localized within the "a" determinant, using a panel of recombinant mutant HBsAgs. The topology of the epitopes was analyzed by competitive enzyme-linked immunosorbent assay (ELISA). Our results indicate that all of the mAbs seem to recognize epitopes within or in the vicinity of the "a" determinant of HBsAg. Different patterns of binding with mutant forms were observed with different mAbs. Amino acid substitutions at positions 123, 126, 129, 144, and 145 dramatically reduced the reactivity of antibodies with HBsAg. The T123N mutation had the largest impact on antibody binding to HBsAg. The reactivity pattern of our panel of mAbs with mutant forms of HBsAg could have important clinical implications for immunoscreening, diagnosis of HBV infection, design of a new generation of recombinant HB vaccines, and immunoprophylaxis of HBV infection as an alternative to therapy with hepatitis B immune globulin (HBIG).

  9. Prevalence of Hepatitis B Surface Antigen in US-Born and Foreign-Born Asian/Pacific Islander College Students

    Science.gov (United States)

    Quang, Yen N.; Vu, Joanne; Yuk, Jihey; Li, Chin-Shang; Chen, Moon; Bowlus, Christopher L.

    2010-01-01

    The prevalence of chronic hepatitis B (HBV) among college-age US-born Asian and Pacific Islanders (A/PI) is not well known. Objectives: To compare the prevalence of hepatitis B surface antigen (HBsAg) seropositivity in US-born to A/PI-born students at a public university. Participants: Undergraduate who self-identified themselves as A/PI. Results:…

  10. Protective vaccination with promastigote surface antigen 2 from Leishmania major is mediated by a TH1 type of immune response.

    OpenAIRE

    Handman, E; Symons, F M; Baldwin, T M; Curtis, J M; Scheerlinck, J P

    1995-01-01

    Leishmania major promastigote surface antigen-2 complex (PSA-2) comprises a family of three similar but distinct polypeptides. The three PSA-2 polypeptides were purified from cultured promastigotes by a combination of detergent phase separation and monoclonal antibody affinity chromatography. Intraperitoneal vaccination of C3H/He mice with PSA-2 with Corynebacterium parvum as an adjuvant resulted in complete protection from lesion development after challenge infection with virulent L. major. ...

  11. In Vitro Evaluation of a Soluble Leishmania Promastigote Surface Antigen as a Potential Vaccine Candidate against Human Leishmaniasis

    OpenAIRE

    Chamakh-Ayari, Rym; Bras-Gonçalves, Rachel; Bahi-Jaber, Narges; Petitdidier, Elodie; Markikou-Ouni, Wafa; Aoun, Karim; Moreno, Javier; Carrillo, Eugenia; Salotra, Poonam; Kaushal, Himanshu; Negi, Narender Singh; Arevalo, Jorge; Falconi-Agapito, Francesca; Privat, Angela; Cruz, Maria

    2014-01-01

    PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb)...

  12. Cancer testis antigen vaccination affords long-term protection in a murine model of ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Maurizio Chiriva-Internati

    Full Text Available Sperm protein (Sp17 is an attractive target for ovarian cancer (OC vaccines because of its over-expression in primary as well as in metastatic lesions, at all stages of the disease. Our studies suggest that a Sp17-based vaccine can induce an enduring defense against OC development in C57BL/6 mice with ID8 cells, following prophylactic and therapeutic treatments. This is the first time that a mouse counterpart of a cancer testis antigen (Sp17 was shown to be expressed in an OC mouse model, and that vaccination against this antigen significantly controlled tumor growth. Our study shows that the CpG-adjuvated Sp17 vaccine overcomes the issue of immunologic tolerance, the major barrier to the development of effective immunotherapy for OC. Furthermore, this study provides a better understanding of OC biology by showing that Th-17 cells activation and contemporary immunosuppressive T-reg cells inhibition is required for vaccine efficacy. Taken together, these results indicate that prophylactic and therapeutic vaccinations can induce long-standing protection against OC and delay tumor growth, suggesting that this strategy may provide additional treatments of human OC and the prevention of disease onset in women with a family history of OC.

  13. Characterisation of peptide microarrays for studying antibody-antigen binding using surface plasmon resonance imagery.

    Directory of Open Access Journals (Sweden)

    Claude Nogues

    Full Text Available BACKGROUND: Non-specific binding to biosensor surfaces is a major obstacle to quantitative analysis of selective retention of analytes at immobilized target molecules. Although a range of chemical antifouling monolayers has been developed to address this problem, many macromolecular interactions still remain refractory to analysis due to the prevalent high degree of non-specific binding. We describe how we use the dynamic process of the formation of self assembling monolayers and optimise physical and chemical properties thus reducing considerably non-specific binding and allowing analysis of specific binding of analytes to immobilized target molecules. METHODOLOGY/PRINCIPAL FINDINGS: We illustrate this approach by the production of specific protein arrays for the analysis of interactions between the 65kDa isoform of human glutamate decarboxylase (GAD65 and a human monoclonal antibody. Our data illustrate that we have effectively eliminated non-specific interactions with the surface containing the immobilised GAD65 molecules. The findings have several implications. First, this approach obviates the dubious process of background subtraction and gives access to more accurate kinetic and equilibrium values that are no longer contaminated by multiphase non-specific binding. Second, an enhanced signal to noise ratio increases not only the sensitivity but also confidence in the use of SPR to generate kinetic constants that may then be inserted into van't Hoff type analyses to provide comparative DeltaG, DeltaS and DeltaH values, making this an efficient, rapid and competitive alternative to ITC measurements used in drug and macromolecular-interaction mechanistic studies. Third, the accuracy of the measurements allows the application of more intricate interaction models than simple Langmuir monophasic binding. CONCLUSIONS: The detection and measurement of antibody binding by the type 1 diabetes autoantigen GAD65 represents an example of an antibody-antigen

  14. The PSA-2 glycoprotein complex of Leishmania major is a glycosylphosphatidylinositol-linked promastigote surface antigen.

    Science.gov (United States)

    Murray, P J; Spithill, T W; Handman, E

    1989-12-15

    Polyclonal rabbit antiserum to the Triton X-114 phase material of Leishmania major, which comprises the surface and internal integral membrane proteins of the parasite, was used to screen a lambda gt11 genomic expression library. A recombinant clone producing a Mr 123,000 beta-galactosidase fusion protein was isolated. Antibodies affinity-purified on this fusion protein recognized a complex of three surface-oriented proteins of promastigotes of L. major of Mr 94,000, 90,000, and 80,000 that we have termed the promastigote surface Ag 2 (PSA-2) complex. The DNA sequence of the insert in this clone predicted the 3' end of an open reading frame encoding a hydrophobic C-terminus. The inferred C-terminal sequence was suggestive of a glycosylphosphatidyl-inositol membrane anchoring mechanism. Phosphatidylinositol-specific phospholipase C treatment of the native PSA-2 proteins caused a shift in their electrophoretic mobility with an apparent reduction in the molecular weight of the PSA-2 complex. After phospholipase C treatment these proteins also displayed the cryptic cross-reacting determinant recognized by antibodies to the Trypanosoma brucei variant surface Ag. Moreover, PSA-2, which previously partitioned in the detergent phase after Triton X-114 phase separation, became water-soluble after phospholipase C treatment. Immunoprecipitation of the PSA-2 proteins with sera directed to lectin-binding proteins indicated that these polypeptides may be differentially glycosylated. Finally, these PSA-2 proteins were recognized by sera from some patients with cutaneous leishmaniasis.

  15. Escherichia coli Nissle 1917 bacterial ghosts retain crucial surface properties and express chlamydial antigen: an imaging study of a delivery system for the ocular surface.

    Science.gov (United States)

    Montanaro, Jacqueline; Inic-Kanada, Aleksandra; Ladurner, Angela; Stein, Elisabeth; Belij, Sandra; Bintner, Nora; Schlacher, Simone; Schuerer, Nadine; Mayr, Ulrike Beate; Lubitz, Werner; Leisch, Nikolaus; Barisani-Asenbauer, Talin

    2015-01-01

    To target chronic inflammatory ocular surface diseases, a drug delivery platform is needed that is safe, possesses immunomodulatory properties, and can be used either for drug delivery, or as a foreign antigen carrier. A new therapeutic approach that we have previously proposed uses nonliving bacterial ghosts (BGs) as a carrier-delivery system which can be engineered to carry foreign antigens and/or be loaded with therapeutic drugs. The parent strain chosen for development of our BG delivery system is the probiotic Escherichia coli strain Nissle 1917 (EcN), whose intrinsic properties trigger the innate immune system with the flagella and fimbriae used to attach and stimulate epithelial cells. In previous studies, we have shown that EcN BGs are safe for the ocular surface route, but evidence that EcN BGs retain flagella and fimbriae after transformation, has never been visually confirmed. In this study, we used different visualization techniques to determine whether flagella and fimbriae are retained on EcN BGs engineered either for drug delivery or as a foreign antigen carrier. We have also shown by immunoelectron microscopy that EcN retains two foreign antigens after processing to become EcN BGs. Furthermore, we demonstrated that BGs derived from EcN and expressing a foreign antigen attachment to conjunctival epithelial cells in vitro without causing reduced cell viability. These results are an important step in constructing a delivery system based on a nonliving probiotic that is suitable for use in ocular surface diseases pairing immunomodulation and targeted delivery.

  16. Surface Antigen Profiling of Helicobacter pylori-Infected and -Uninfected Gastric Cancer Cells Using Antibody Microarray.

    Science.gov (United States)

    Sukri, Asif; Hanafiah, Alfizah; Kosai, Nik Ritza; Mohamed Taher, Mustafa; Mohamed Rose, Isa

    2016-10-01

    Comprehensive immunophenotyping cluster of differentiation (CD) antigens in gastric adenocarcinoma, specifically between Helicobacter pylori-infected and -uninfected gastric cancer patients by using DotScan(™) antibody microarray has not been conducted. Current immunophenotyping techniques include flow cytometry and immunohistochemistry are limited to the use of few antibodies for parallel examination. We used DotScan(™) antibody microarray consisting 144 CD antibodies to determine the distribution of CD antigens in gastric adenocarcinoma cells and to elucidate the effect of H. pylori infection toward CD antigen expression in gastric cancer. Mixed leukocytes population derived from gastric adenocarcinoma patients were immunophenotyped using DotScan(™) antibody microarray. AGS cells were infected with H. pylori strains and cells were captured on DotScan(™) slides. Cluster of differentiation antigens involved in perpetuating the tolerance of immune cells to tumor cells was upregulated in gastric adenocarcinoma cells compared to normal cells. CD279 which is essential in T cells apoptosis was found to be upregulated in normal cells. Remarkably, H. pylori-infected gastric cancer patients exhibited upregulated expression of CD27 that important in maintenance of T cells. Infection of cagA+ H. pylori with AGS cells increased CD antigens expression which involved in cancer stem cell while cagA- H. pylori polarized AGS cells to express immune-regulatory CD antigens. Increased CD antigens expression in AGS cells infected with cagA+ H. pylori were also detected in H. pylori-infected gastric cancer patients. This study suggests the tolerance of immune system toward tumor cells in gastric cancer and distinct mechanisms of immune responses exploited by different H. pylori strains. © 2016 John Wiley & Sons Ltd.

  17. Effect of a novel saponin adjuvant derived from Quillaja saponaria on the immune response to recombinant hepatitis B surface antigen.

    Science.gov (United States)

    So, H S; Yoon, H S; Choi, D Y; Kwon, Y S; Sung, J H; Lee, T G; Park, E S; Cho, H S; Lee, B M; Cho, J M; Ryu, W S

    1997-04-30

    Adjuvant activity of saponins extracted from the South American tree Quillaja saponaria has been demonstrated with many antigens. Recently, four saponin fractions (designated as QS-7, QS-17, QS-18, and QS-21) with adjuvant activity were purified by reverse phase chromatography. In particular, efficacy of the less toxic QS-21 fraction has been demonstrated with several recombinant viral antigens including HIV gp120. Here, we report a novel saponin fraction (designated as QS-L1) derived from Quillaja saponaria. Unlike previously identified saponins, QS-L1 had a different chemical structure and showed adjuvant activity only when administered in the presence of alum-precipitated antigen. Interestingly, the QS-L1 greatly increased not only a humoral immune response but also cellular immune response to recombinant hepatitis B virus surface antigen (HBsAg). Furthermore, QS-L1 showed lower toxicity in vivo and in vitro than the previously identified saponin fraction, QS-21. Finally, we examined the chemical structure of the QS-L1 using mass spectroscopic analysis, carbohydrate composition analysis and NMR spectroscopic analysis. Thus, our results indicated that this novel QS-L1 saponin fraction had several desirable properties required for an effective adjuvant.

  18. Novel Plasmodium falciparum malaria vaccines: evidence-based searching for variant surface antigens as candidates for vaccination against pregnancy-associated malaria

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Jensen, Anja T R; Theander, Thor G

    2002-01-01

    Malaria vaccine development has traditionally concentrated on careful molecular, biochemical, and immunological characterisation of candidate antigens. In contrast, evidence of the importance of identified antigens in immunity to human infection and disease has generally been limited......) in particular, to provide robust evidence of a causal link between the two in order to allow efficient and evidence-based identification of candidate antigens for malaria vaccine development....... to statistically significant co-variation with protection rather than on demonstration of causal relationships. We have studied the relationship between variant surface antigen-specific antibodies and clinical protection from Plasmodium falciparum malaria in general, and from pregnancy-associated malaria (PAM...

  19. Trichinella britovi human infection in Spain : antibody response to surface, excretory/secretory and somatic antigens

    Directory of Open Access Journals (Sweden)

    Rodríguez-Osorio M.

    2003-06-01

    Full Text Available A third outbreak of Trichinella britovi with 140 people involved, occurred in Granada Spain (December 1998. The source of infection was sausage made from uninspected wild boar meat. Fifty-two patients agreed to participated in this study. An elevated eosinophil level (> 5 % was detected in 59.6 % of patients, and persisted in most of these cases for two months. A moderate IgG response was observed. At the onset of symptoms, Western blot (WB test detected more positive cases than Enzyme linked immunosorbent assay (ELISA and indirect immunofluorescence (IIF. Six months from infection, ELISA revealed fewer positive cases than the other two tests. It would appear that the response to somatic antigens starts earlier than those to cuticular and excretory/secretory (ES antigens and that the response to ES antigens is the first to decrease.

  20. Expression of myeloid antigens on lymphoblast surface in childhood acute lymphoblastic leukemia at diagnosis and its effect on early response to treatment: a preliminary report.

    Science.gov (United States)

    Sobol-Milejska, Grazyna; Mizia-Malarz, Agnieszka; Wos, Halina

    2013-09-01

    Immunodiagnosis of acute lymphoblastic leukemia (ALL) is based on the assessment of surface antigens. There are also cases in which both lymphoid and myeloid antigens can be found on the surface of lymphoblasts. The purpose of our research was to assess the expression of myeloid and lymphoblastic antigens in children with ALL, and to determine the impact of surface antigens on early response to treatment. 58 children [33 girls (56.9 %), 25 boys (43.2 %)] with ALL were studied. Response to treatment was assessed on days 8, 15, and 33. Univariate logistic regression analysis of the effect of myeloid antigens (MyAg) on response to treatment on days 8 and 33 revealed expression of any MyAg on lymphoblast surface as a factor associated with poor response to treatment. The multivariate logistic regression analysis of treatment response on day 33, showed that the expression of CD13 antigen on lymphoblast surface is a key factor affecting delayed remission (p = 0.03; odds ratio 0.12; 95 % CI 0.01-0.81). The expression of MyAg in childhood ALL adversely affects early response to treatment. The expression of CD13 antigen on day 33 is a key factor affecting complete remission in ALL patients.

  1. The Murine Humoral Immune Response to Hepatitis B Surface Antigen: Idiotype Network Pathways.

    Science.gov (United States)

    Schick, Michael Roy

    Recognition of a wide spectrum in disease outcomes following Hepatitis B Virus (HBV) infection has led to the suggestion that individual differences may be due to characteristics of the immune response. HBV, a hepatotropic virus, is not directly cytopathic to the host hepatocytes but the cellular damage which does not occur may be due to the host's own immune response. It is this variety in immune response capabilities following natural infection or vaccination which led to the present study in which the murine humoral immune response to hepatitis B surface antigen (HBsAg) was examined. Following immunization with purified HBsAg an anti-HBs response could be detected in 19 inbred strains of mice. The response, which varied among the strains, was linked to the major histocompatibility complex (MHC). Among high responders to HBsAg were two strains in which a poor response to a single epitope could be detected. Although quantitatively serum from these strains resembled serum from other high responders, there was a major difference in the qualitative aspects. Included within this study was the role of idotype networks within the murine anti-HBs response. By directly targeting HBsAg-specific B cells within the framework of an idiotype network by an Ab-2, it was possible to circumvent T cell-dependent regulation of an immune response. In each of five inbred strains of mice immunized with a polyclonal rabbit Ab-2 an Ab-3 population with HBsAg-specificity (Ab -1^') was induced. These mice were also immunized with HBsAg resulting in a higher anti-HBs response as compared to HBsAg immunization alone in all of the strains tested except for one. The response in this strain, normally a low responder to HBsAg, indicated that the mechanisms for genetic restriction of the anti -HBs response was still active, although it was not apparent during anti-Id immunization. The effects of an anti-Id on the murine antibody response to HBsAg may lead to insights on the presence of idiotype

  2. Long-term stable surface modification of DLC coatings

    Directory of Open Access Journals (Sweden)

    Gotzmann Gaby

    2017-09-01

    Full Text Available The use of coatings based on diamond like carbon (DLC for medical applications was established during the last years. Main advantages of these coatings are its high hardness, good wear and friction behavior and its biocompatibility. Using low-energy electron-beam treatment, we addressed the surface modification of DLC coatings. The aim was to generate new biofunctional surface characteristics that are long-term stable.

  3. Entanglement entropy from surface terms in general relativity

    OpenAIRE

    Bhattacharyya, Arpan; Sinha, Aninda

    2013-01-01

    Entanglement entropy in local quantum field theories is typically ultraviolet divergent due to short distance effects in the neighbourhood of the entangling region. In the context of gauge/gravity duality, we show that surface terms in general relativity are able to capture this entanglement entropy. In particular, we demonstrate that for 1+1 dimensional CFTs at finite temperature whose gravity dual is the BTZ black hole, the Gibbons-Hawking-York term precisely reproduces the entanglement ent...

  4. A 135-kilodalton surface antigen of Mycoplasma hominis PG21 contains multiple directly repeated sequences

    DEFF Research Database (Denmark)

    Ladefoged, Søren; Birkelund, Svend; Hauge, S

    1995-01-01

    -base substitution, C-->A, gave rise to the stop codon of lmp1. Thus, the C-terminal 945 amino acids were encoded by the 471-bp direct repeats. As evidenced by Southern blot analysis, the gene encoding the 135-kDa antigen is part of a multigene family. One of the genes, lmp2, was situated directly downstream from...

  5. Rapid screening and identification of dominant B cell epitopes of HBV surface antigen by quantum dot-based fluorescence polarization assay

    Science.gov (United States)

    Meng, Zhongji; Song, Ruihua; Chen, Yue; Zhu, Yang; Tian, Yanhui; Li, Ding; Cui, Daxiang

    2013-03-01

    A method for quickly screening and identifying dominant B cell epitopes was developed using hepatitis B virus (HBV) surface antigen as a target. Eleven amino acid fragments from HBV surface antigen were synthesized by 9-fluorenylmethoxy carbonyl solid-phase peptide synthesis strategy, and then CdTe quantum dots were used to label the N-terminals of all peptides. After optimizing the factors for fluorescence polarization (FP) immunoassay, the antigenicities of synthetic peptides were determined by analyzing the recognition and combination of peptides and standard antibody samples. The results of FP assays confirmed that 10 of 11 synthetic peptides have distinct antigenicities. In order to screen dominant antigenic peptides, the FP assays were carried out to investigate the antibodies against the 10 synthetic peptides of HBV surface antigen respectively in 159 samples of anti-HBV surface antigen-positive antiserum. The results showed that 3 of the 10 antigenic peptides may be immunodominant because the antibodies against them existed more widely among the samples and their antibody titers were higher than those of other peptides. Using three dominant antigenic peptides, 293 serum samples were detected for HBV infection by FP assays; the results showed that the antibody-positive ratio was 51.9% and the sensitivity and specificity were 84.3% and 98.2%, respectively. In conclusion, a quantum dot-based FP assay is a very simple, rapid, and convenient method for determining immunodominant antigenic peptides and has great potential in applications such as epitope mapping, vaccine designing, or clinical disease diagnosis in the future.

  6. Planckian energy scattering and surface terms in the gravitational action

    CERN Document Server

    Fabbrichesi, Marco E; Veneziano, Gabriele; Vilkovisky, G A

    1994-01-01

    This is a revised version of our previous paper by the same name and preprint number. It contains various changes, two figures and new results in sect.5. We propose a new approach to four-dimensional Planckian-energy scattering in which the phase of the ${\\cal S}$-matrix is written---to leading order in $\\hbar$ and to all orders in $R/b =Gs/J$---in terms of the surface term of the gravity action and of a boundary term for the colliding quanta. The proposal is checked at the leading order in $R/b$ and also against some known examples of scattering in strong gravitational fields.

  7. Escherichia coli Nissle 1917 bacterial ghosts retain crucial surface properties and express chlamydial antigen: an imaging study of a delivery system for the ocular surface

    Directory of Open Access Journals (Sweden)

    Montanaro J

    2015-07-01

    Full Text Available Jacqueline Montanaro,1 Aleksandra Inic-Kanada,1 Angela Ladurner,1 Elisabeth Stein,1 Sandra Belij,1 Nora Bintner,1 Simone Schlacher,1 Nadine Schuerer,1 Ulrike Beate Mayr,2 Werner Lubitz,2 Nikolaus Leisch,3 Talin Barisani-Asenbauer11Laura Bassi Centres of Expertise, OCUVAC – Centre of Ocular Inflammation and Infection, Centre for Pathophysiology, Infectiology, and Immunology, Medical University of Vienna, Vienna, Austria; 2BIRD-C GmbH & Co KG, Kritzendorf, Austria; 3Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, AustriaAbstract: To target chronic inflammatory ocular surface diseases, a drug delivery platform is needed that is safe, possesses immunomodulatory properties, and can be used either for drug delivery, or as a foreign antigen carrier. A new therapeutic approach that we have previously proposed uses nonliving bacterial ghosts (BGs as a carrier-delivery system which can be engineered to carry foreign antigens and/or be loaded with therapeutic drugs. The parent strain chosen for development of our BG delivery system is the probiotic Escherichia coli strain Nissle 1917 (EcN, whose intrinsic properties trigger the innate immune system with the flagella and fimbriae used to attach and stimulate epithelial cells. In previous studies, we have shown that EcN BGs are safe for the ocular surface route, but evidence that EcN BGs retain flagella and fimbriae after transformation, has never been visually confirmed. In this study, we used different visualization techniques to determine whether flagella and fimbriae are retained on EcN BGs engineered either for drug delivery or as a foreign antigen carrier. We have also shown by immunoelectron microscopy that EcN retains two foreign antigens after processing to become EcN BGs. Furthermore, we demonstrated that BGs derived from EcN and expressing a foreign antigen attachment to conjunctival epithelial cells in vitro without causing reduced cell viability. These results

  8. Multisource Estimation of Long-term Global Terrestrial Surface Radiation

    Science.gov (United States)

    Peng, L.; Sheffield, J.

    2017-12-01

    Land surface net radiation is the essential energy source at the earth's surface. It determines the surface energy budget and its partitioning, drives the hydrological cycle by providing available energy, and offers heat, light, and energy for biological processes. Individual components in net radiation have changed historically due to natural and anthropogenic climate change and land use change. Decadal variations in radiation such as global dimming or brightening have important implications for hydrological and carbon cycles. In order to assess the trends and variability of net radiation and evapotranspiration, there is a need for accurate estimates of long-term terrestrial surface radiation. While large progress in measuring top of atmosphere energy budget has been made, huge discrepancies exist among ground observations, satellite retrievals, and reanalysis fields of surface radiation, due to the lack of observational networks, the difficulty in measuring from space, and the uncertainty in algorithm parameters. To overcome the weakness of single source datasets, we propose a multi-source merging approach to fully utilize and combine multiple datasets of radiation components separately, as they are complementary in space and time. First, we conduct diagnostic analysis of multiple satellite and reanalysis datasets based on in-situ measurements such as Global Energy Balance Archive (GEBA), existing validation studies, and other information such as network density and consistency with other meteorological variables. Then, we calculate the optimal weighted average of multiple datasets by minimizing the variance of error between in-situ measurements and other observations. Finally, we quantify the uncertainties in the estimates of surface net radiation and employ physical constraints based on the surface energy balance to reduce these uncertainties. The final dataset is evaluated in terms of the long-term variability and its attribution to changes in individual

  9. Association of HCV Core Antigen Seropositivity with Long-Term Mortality in Patients on Regular Hemodialysis

    Directory of Open Access Journals (Sweden)

    Akihiko Kato

    2012-03-01

    Full Text Available Anti-hepatitis C virus (HCV antibody seropositivity is independently associated with poor prognosis in hemodialysis (HD patients. However, anti-HCV antibody cannot distinguish between patients with active infection and those who have recovered from infection. We therefore aimed in this study to examine the association of HCV core antigen (HCVcAg seropositivity with mortality in HD patients. We first measured serum HCVcAg using an immunoradiometric assay and anti-HCV antibody in 405 patients on regular HD, and followed them for 104 months. There were 82 patients (20.2% who had been positive for anti-HCV antibodies; 57 (69.5% of these were positive for HCVcAg. During the follow-up, 29 patients were excluded, so we tested the association of HCVcAg seropositivity with all-cause, cardiovascular (CV and non-CV mortalities in 376 patients. A total of 209 patients (55.6% had expired during the observational period, 92 out of them due to CV causes. After adjusting for comorbid parameters, HCVcAg was independently associated with overall mortality (HR 1.61, 95% CI 1.05–2.47, p < 0.05. HCV infection was significantly related to liver disease-related mortality. Past HCV infection also contributed to CV mortality (HR 2.63, 95% CI 1.27–5.45, p < 0.01. In contrast, anti-HCV antibody and HCVcAg seropositivities did not associate with infectious disease-related and cancer-related (expect for hepatocellular carcinoma mortality. It follows from these findings that HCVcAg serology is associated with all-cause and CV mortality in HD patients.

  10. Identification of a novel dendritic cell surface antigen defined by carbohydrate specific CD24 antibody cross-reactivity.

    Science.gov (United States)

    Williams, L A; McLellan, A D; Summers, K L; Sorg, R V; Fearnley, D B; Hart, D N

    1996-01-01

    Dendritic cells (DC) are characterized as leucocytes that lack mature lineage specific markers and stimulate naive T-lymphocyte proliferation in vitro and in vivo. The mouse heat stable antigen (HSA) participates in T lymphocyte co-stimulation and is expressed by DC isolated from thymus, skin and spleen. The human HSA homologue, CD24, is predominantly expressed by B lymphocytes and granulocytes, but its expression on DC has not been studied in detail. CD24 clearly participates in B-lymphocyte signalling but co-stimulatory activity for T lymphocytes has not yet been described. We have examined the expression of CD24 on human peripheral blood DC populations isolated directly or following in vitro culture. The CD24 antigen was absent from blood DC however, cross-reactive sialylated carbohydrate epitopes were detected on DC with some CD24 monoclonal antibodies (mAb). These CD24 mAb define a protein surface antigen, which is expressed by an immature or resting subpopulation of peripheral blood DC and is down-regulated following activation differentiation in vitro. PMID:8911149

  11. Surface-enhanced Raman scattering study of carcinoembryonic antigen in serum from patients with colorectal cancers

    Science.gov (United States)

    Chen, Gang; Chen, Yanping; Zheng, Xiongwei; He, Cheng; Lu, Jianping; Feng, Shangyuan; Chen, Rong; Zeng, Haisan

    2013-12-01

    In this work, we developed a SERS platform for quantitative detection of carcinoembryonic antigen (CEA) in serum of patients with colorectal cancers. Anti-CEA-functionalized 4-mercaptobenzoic acid-labeled Au/Ag core-shell bimetallic nanoparticles were prepared first and then used to analyze CEA antigen solutions of different concentrations. A calibration curve was established in the range from 5 × 10-3 to 5 × 105 ng/mL. Finally, this new SERS probe was applied for quantitative detection of CEA in serum obtained from 26 colorectal cancer patients according to the calibration curve. The results were in good agreement with that obtained by electrochemical luminescence method, suggesting that SERS immunoassay has high sensitivity and specificity for CEA detection in serum. A detection limit of 5 pg/ml was achieved. This study demonstrated the feasibility and great potential for developing this new technology into a clinical tool for analysis of tumor markers in the blood.

  12. Evaluation of a Major Surface Antigen of Babesia microti Merozoites as a Vaccine Candidate against Babesia Infection

    Directory of Open Access Journals (Sweden)

    Suqin Man

    2017-12-01

    Full Text Available Babesia species are tick-borne intraerythrocytic protozoa that cause babesiosis in humans worldwide. No vaccine has yet proven effective against Babesia infection. Surface antigens of merozoites are involved in the invasion of erythrocytes by Babesia. Surface antigens may be presented by both babesial sporozoites and merozoites and provide a general target for antibody-mediated inhibition of erythrocyte invasion. Here we evaluated a major surface antigen of B. microti merozoites, BMSA, as a potential vaccine to prevent babesiosis. Our data indicated that bmsa is transcribed during different phases, including ring form, amoeboid form, and merozoites, and that its expression is significantly increased in mature merozoites. The protein was found to be located in the membrane of B. microti and in the cytoplasm of infected erythrocytes. The immune response induced by BMSA had a significant inhibitory effect on parasite invasion of the host erythrocytes (83.3% inhibition of invasion and parasite growth in vivo. The levels of parasitemia significantly decreased after BMSA vaccination when mice were infected with babesia parasite. Importantly, protective immunity was significantly related to the upregulation of the Th17 cytokine interleukin-17, the Th1 cytokine interleukin-12p70 and the Th2 cytokines, such as interleukin-4, -6, and -10. Ingenuity Pathway Analysis indicated that interleukin-17 facilitated the secretion of Th2 cytokines, such as interleukin-10, -4, and -6, thereby inducing a predominately Th2 protective immune response and promoting the expression a high level of special IgG1 against Babesia infection. Further, an anti-BMSA monoclonal antibody successfully protected NOD/SCID mice from a challenge with B. microti. Taken together, our results indicated that BMSA induces a protective immune response against Babesia infection and may serve as a potential vaccine.

  13. Seroprevalence of Hepatitis B Surface Antigen and Occupational Risk Factors Among Health Care Workers in Ekiti State, Nigeria

    Science.gov (United States)

    Alese, Oluwole Ojo; Ohunakin, Afolabi; Oluyide, Peter Olumuyiwa

    2016-01-01

    Introduction Hepatitis B virus (HBV) infection is contracted from blood and other body fluid making healthcare workers (HCW) prone to the infection especially in the developing world. Though it is a vaccine preventable disease, the level of awareness and universal precaution among HCW is low in sub-Saharan African and Asia. Aim The study was aimed at determining the seroprevalence of hepatitis B surface antigen and occupational risk factors among health care workers at Ekiti State University Teaching Hospital, Ado Ekiti. Materials and Methods One hundred and eighty-seven (187) blood samples were collected from volunteer subjects who comprised of medical doctors, nurses, health attendants, and porters who are in regular contact with blood, body fluids and patients after informed consent. Well detailed and structured questionnaires were used to obtain demographic and other relevant data from the subjects. Blood samples were tested by Enzyme Linked Immunosorbent assay (ELISA) for hepatitis B surface antigen. Results Out of the 187 HCWs there were 91 males (48.7%) and 96 (51.3%) females. Only 2 participants tested positive to hepatitis B surface antigen with a prevalence of 1.1%. Also, only 30 (16.0%) of the participants had been fully vaccinated against the infection while the remaining 157(84.0%) had no adult vaccination. Conclusion It is obvious that the awareness of the infection is low among the HCWs studied thus the need to incorporate screening for HbsAg and vaccination against HBV into the periodic/pre-employment health intervention programmes by employers to help in the protection of HCWs and control the spread of the virus. PMID:27042489

  14. Seroprevalence of Hepatitis B Surface Antigen and Occupational Risk Factors Among Health Care Workers in Ekiti State, Nigeria.

    Science.gov (United States)

    Alese, Oluwole Ojo; Alese, Margaret Olutayo; Ohunakin, Afolabi; Oluyide, Peter Olumuyiwa

    2016-02-01

    Hepatitis B virus (HBV) infection is contracted from blood and other body fluid making healthcare workers (HCW) prone to the infection especially in the developing world. Though it is a vaccine preventable disease, the level of awareness and universal precaution among HCW is low in sub-Saharan African and Asia. The study was aimed at determining the seroprevalence of hepatitis B surface antigen and occupational risk factors among health care workers at Ekiti State University Teaching Hospital, Ado Ekiti. One hundred and eighty-seven (187) blood samples were collected from volunteer subjects who comprised of medical doctors, nurses, health attendants, and porters who are in regular contact with blood, body fluids and patients after informed consent. Well detailed and structured questionnaires were used to obtain demographic and other relevant data from the subjects. Blood samples were tested by Enzyme Linked Immunosorbent assay (ELISA) for hepatitis B surface antigen. Out of the 187 HCWs there were 91 males (48.7%) and 96 (51.3%) females. Only 2 participants tested positive to hepatitis B surface antigen with a prevalence of 1.1%. Also, only 30 (16.0%) of the participants had been fully vaccinated against the infection while the remaining 157(84.0%) had no adult vaccination. It is obvious that the awareness of the infection is low among the HCWs studied thus the need to incorporate screening for HbsAg and vaccination against HBV into the periodic/pre-employment health intervention programmes by employers to help in the protection of HCWs and control the spread of the virus.

  15. Picomolar detection of carcinoembryonic antigen in whole blood using microfluidics and surface-enhanced Raman spectroscopy.

    Science.gov (United States)

    Zou, Kun; Gao, Zhigang; Deng, Quanfeng; Luo, Yong; Zou, Lijuan; Lu, Yao; Zhao, Weijie; Lin, Bingcheng

    2016-03-01

    Carcinoembryonic antigen (CEA) is a wide-spectrum biomarker. Clinically, we generally use serum sample to detect CEA, which needs to be centrifuged to pretreat the raw blood sample. In this study, we realized direct CEA detection in raw blood samples exploiting microfluidics. The LOD was as low as 10(-12) M. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Aberration analysis for freeform surface terms overlay on general decentered and tilted optical surfaces.

    Science.gov (United States)

    Yang, Tong; Cheng, Dewen; Wang, Yongtian

    2018-03-19

    Aberration theory helps designers to better understand the nature of imaging systems. However, the existing aberration theory of freeform surfaces has many limitations. For example, it only works in the special case when the central area of the freeform surface is used. In addition, the light footprint is limited to a circle, which does not match the case of an elliptical footprint for general systems. In this paper, aberrations generated by freeform surface term overlay on general decentered and tilted optical surfaces are analyzed. For the case when the off-axis section of a freeform surface is used, the aberration equation for using stop and nonstop surfaces is discussed, and the aberrations generated by Zernike terms up to Z 17/18 are analyzed in detail. To solve the problem of the elliptical light footprint for tilted freeform surfaces, the scaled pupil vector is used in the aberration analysis. The mechanism of aberration transformation is discovered, and the aberrations generated by different Zernike terms in this case are calculated. Finally we proposed aberration equations for freeform terms on general decentered and tilted freeform surfaces. The research result given in this paper offers an important reference for optical designers and engineers, and it is of great importance in developing analytical methods for general freeform system design, tolerance analysis, and system assembly.

  17. Quantitative hepatitis B surface antigen combined with hepatitis B e antigen as sustained virological response predictors during extended therapy with Peginterferon alfa-2a for hepatitis B e antigen-positive chronic hepatitis B.

    Science.gov (United States)

    Chen, Jie; Zhang, Dong-Hua; Xu, Cheng-Run; Zhu, Ming-Yu; Yang, Zhi-Tao; Gong, Qi-Ming; Yu, De-Min; Zhang, Xin-Xin

    2015-11-01

    The best strategy for chronic hepatitis B patients with poor response to 48 weeks of Peginterferon-based therapy has been controversial and the predictive value of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA levels for determining the sustained virological response (SVR) of these patients is uncertain. To optimize management of these patients and evaluate the use of these serobiomarkers to predict SVR. Eighty-one patients with an unsatisfactory response after 48 weeks of Peginterferon-based therapy were treated with extended Peginterferon therapy with or without nucleo(s) tide analogues (NAs), for a total of 96 weeks of Peginterferon treatment. HBsAg, HBeAg and HBV DNA levels were measured serially during the treatment and follow-up. Twenty-six of 81 patients (32.1%) attained SVR during the 72-week follow-up. The SVR rate was not statistically different between groups receiving 1-year prolongation of Peginterferon with or without NAs. The serum HBsAg cut-off of 1800IU/mL at week 48 had area under curve (AUC) of 0.727, and the serum HBsAg cut-off of 1500IU/mL, combined with HBeAg loss at week 72, had AUC of 0.753 to predict SVR during the follow-up. In conclusion, extended treatment with Peginterferon with or without NAs for patients with unsatisfactory response after 48 weeks of Peginterferon-based therapy is a promising strategy to achieve SVR, and quantitative serum HBsAg at week 48 and HBsAg level combined with HBeAg loss at week 72 of therapy can predict SVR to prolongation therapy with Peginterferon. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Circulating Gut-Homing (α4β7+) Plasmablast Responses against Shigella Surface Protein Antigens among Hospitalized Patients with Diarrhea.

    Science.gov (United States)

    Sinha, Anuradha; Dey, Ayan; Saletti, Giulietta; Samanta, Pradip; Chakraborty, Partha Sarathi; Bhattacharya, M K; Ghosh, Santanu; Ramamurthy, T; Kim, Jae-Ouk; Yang, Jae Seung; Kim, Dong Wook; Czerkinsky, Cecil; Nandy, Ranjan K

    2016-07-01

    Developing countries are burdened with Shigella diarrhea. Understanding mucosal immune responses associated with natural Shigella infection is important to identify potential correlates of protection and, as such, to design effective vaccines. We performed a comparative analysis of circulating mucosal plasmablasts producing specific antibodies against highly conserved invasive plasmid antigens (IpaC, IpaD20, and IpaD120) and two recently identified surface protein antigens, pan-Shigella surface protein antigen 1 (PSSP1) and PSSP2, common to all virulent Shigella strains. We examined blood and stool specimens from 37 diarrheal patients admitted to the Infectious Diseases & Beliaghata General Hospital, Kolkata, India. The etiological agent of diarrhea was investigated in stool specimens by microbiological methods and real-time PCR. Gut-homing (α4β7 (+)) antibody-secreting cells (ASCs) were isolated from patient blood by means of combined magnetic cell sorting and two-color enzyme-linked immunosorbent spot (ELISPOT) assay. Overall, 57% (21 of 37) and 65% (24 of 37) of the patients were positive for Shigella infection by microbiological and real-time PCR assays, respectively. The frequency of α4β7 (+) IgG ASC responders against Ipas was higher than that observed against PSSP1 or PSSP2, regardless of the Shigella serotype isolated from these patients. Thus, α4β7 (+) ASC responses to Ipas may be considered an indirect marker of Shigella infection. The apparent weakness of ASC responses to PSSP1 is consistent with the lack of cross-protection induced by natural Shigella infection. The finding that ASC responses to IpaD develop in patients with recent-onset shigellosis indicates that such responses may not be protective or may wane too rapidly and/or be of insufficient magnitude. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  19. Well-known surface and extracellular antigens of pathogenic microorganisms among the immunodominant proteins of the infectious microalgae Prototheca zopfii.

    Science.gov (United States)

    Irrgang, Alexandra; Murugaiyan, Jayaseelan; Weise, Christoph; Azab, Walid; Roesler, Uwe

    2015-01-01

    Microalgae of the genus Prototheca (P.) are associated with rare but severe infections (protothecosis) and represent a potential zoonotic risk. Genotype (GT) 2 of P. zopfii has been established as pathogenic agent for humans, dogs, and cattle, whereas GT1 is considered to be non-pathogenic. Since pathogenesis is poorly understood, the aim of this study was to determine immunogenic proteins and potential virulence factors of P. zopfii GT2. Therefore, 2D western blot analyses with sera and isolates of two dogs naturally infected with P. zopfii GT2 have been performed. Cross-reactivity was determined by including the type strains of P. zopfii GT2, P. zopfii GT1, and P. blaschkeae, a close relative of P. zopfii, which is known to cause subclinical forms of bovine mastitis. The sera showed a high strain-, genotype-, and species-cross-reactivity. A total of 198 immunogenic proteins have been analyzed via MALDI-TOF MS. The majority of the 86 identified proteins are intracellularly located (e.g., malate dehydrogenase, oxidoreductase, 3-dehydroquinate synthase) but some antigens and potential virulence factors, known from other pathogens, have been found (e.g., phosphomannomutase, triosephosphate isomerase). One genotype-specific antigen could be identified as heat shock protein 70 (Hsp70), a well-known antigen of eukaryotic pathogens with immunological importance when located extracellularly. Both sera were reactive to glyceraldehyde-3-phosphate-dehydrogenase of all investigated strains. This house-keeping enzyme is found to be located on the surface of several pathogens as virulence factor. Flow-cytometric analysis revealed its presence on the surface of P. blaschkeae.

  20. Well-known surface and extracellular antigens of pathogenic microorganisms among the immunodominant proteins of the infectious microalgae Prototheca zopfii

    Directory of Open Access Journals (Sweden)

    Alexandra eIrrgang

    2015-09-01

    Full Text Available Microalgae of the genus Prototheca (P. are associated with rare but severe infections (protothecosis and represent a potential zoonotic risk. Genotype (GT 2 of P. zopfii has been established as pathogenic agent for humans, dogs and cattle, whereas GT1 is considered to be non-pathogenic. Since pathogenesis is poorly understood, the aim of this study was to determine immunogenic proteins and potential virulence factors of P. zopfii GT2. Therefore, 2D western blot analyses with sera and isolates of two dogs naturally infected with P. zopfii GT2 have been performed. Cross-reactivity was determined by including the type strains of P. zopfii GT2, P. zopfii GT1 and P. blaschkeae, a close relative of P. zopfii, which is known to cause subclinical forms of bovine mastitis. The sera showed a high strain-, genotype-, and species-cross-reactivity. A total of 198 immunogenic proteins have been analysed via MALDI- TOF MS. The majority of the 86 identified proteins are intracellularly located (e.g. malate dehydrogenase, oxidoreductase, 3-dehydroquinate synthase but some antigens and potential virulence factors, known from other pathogens, have been found (e.g. phosphomannomutase, triosephosphate isomerase. One genotype-specific antigen could be identified as heat shock protein 70 (Hsp70, a well-known antigen of eukaryotic pathogens with immunological importance when located extracellularly. Both sera were reactive to glyceraldehyde-3-phosphate-dehydrogenase of all investigated strains. This house-keeping enzyme is found to be located on the surface of several pathogens as virulence factor. Flow-cytometric analysis revealed its presence on the surface of P. blaschkeae.

  1. A reusable localized surface plasmon resonance biosensor for quantitative detection of serum squamous cell carcinoma antigen in cervical cancer patients based on silver nanoparticles array

    Directory of Open Access Journals (Sweden)

    Zhao Q

    2014-02-01

    Full Text Available Qianying Zhao,1 Ruiqi Duan,1 Jialing Yuan,1 Yi Quan,1 Huan Yang,2 Mingrong Xi1 1Department of Gynecology and Obstetrics, West China Second University Hospital, Sichuan University, 2State Key Laboratory of Optical Technologies for Micro-fabrication, Institute of Optics and Electronics, Chinese Academy of Science, Chengdu, Sichuan, People's Republic of China Abstract: Squamous cell carcinoma antigen (SCCa, as a tumor biomarker, plays an important role in adjuvant diagnosis, treatment evaluation, and prognosis prediction for cervical cancer patients. Localized surface plasmon resonance (LSPR technique based on noble metal nanoparticles bypasses the disadvantages of traditional testing strategies, in terms of free-labeling, short assay time, good sensitivity, and selectivity. Herein, we develop a novel and reusable LSPR biosensor for the detection of SCCa. First, a triangle-shaped silver nanoparticle array was fabricated using the nanosphere lithography method. Next, we investigated and verified the feasibility of amino coupling method using 11-mercaptoundecanoic acid (MUA to form a functionalized chip surface with monoclonal anti-SCCa antibodies on the silver nanoparticles for distinct detection of SCCa. Different concentrations of SCCa were successfully tested in both buffer and human serum by the ultrasensitive and specific LSPR system, with a linear quantitative detection range of 0.1–1,000 pM under optimal conditions. With appropriate regeneration solution, for example 50 mM glycine-HCl (pH 2.0, the LSPR biosensor featured effective fabrication reproducibility, which reduced both production cost and testing time. Our study represents the first application of the LSPR biosensor in cervical cancer, and demonstrates that the rapid, simple, and reusable nanochip can serve as a potential alternative for clinical serological diagnosis of SCCa in cervical cancer patients. Keywords: localized surface plasmon resonance, nanotechnology, biosensor

  2. A single point in protein trafficking by Plasmodium falciparum determines the expression of major antigens on the surface of infected erythrocytes targeted by human antibodies.

    Science.gov (United States)

    Chan, Jo-Anne; Howell, Katherine B; Langer, Christine; Maier, Alexander G; Hasang, Wina; Rogerson, Stephen J; Petter, Michaela; Chesson, Joanne; Stanisic, Danielle I; Duffy, Michael F; Cooke, Brian M; Siba, Peter M; Mueller, Ivo; Bull, Peter C; Marsh, Kevin; Fowkes, Freya J I; Beeson, James G

    2016-11-01

    Antibodies to blood-stage antigens of Plasmodium falciparum play a pivotal role in human immunity to malaria. During parasite development, multiple proteins are trafficked from the intracellular parasite to the surface of P. falciparum-infected erythrocytes (IEs). However, the relative importance of different proteins as targets of acquired antibodies, and key pathways involved in trafficking major antigens remain to be clearly defined. We quantified antibodies to surface antigens among children, adults, and pregnant women from different malaria-exposed regions. We quantified the importance of antigens as antibody targets using genetically engineered P. falciparum with modified surface antigen expression. Genetic deletion of the trafficking protein skeleton-binding protein-1 (SBP1), which is involved in trafficking the surface antigen PfEMP1, led to a dramatic reduction in antibody recognition of IEs and the ability of human antibodies to promote opsonic phagocytosis of IEs, a key mechanism of parasite clearance. The great majority of antibody epitopes on the IE surface were SBP1-dependent. This was demonstrated using parasite isolates with different genetic or phenotypic backgrounds, and among antibodies from children, adults, and pregnant women in different populations. Comparisons of antibody reactivity to parasite isolates with SBP1 deletion or inhibited PfEMP1 expression suggest that PfEMP1 is the dominant target of acquired human antibodies, and that other P. falciparum IE surface proteins are minor targets. These results establish SBP1 as part of a critical pathway for the trafficking of major surface antigens targeted by human immunity, and have key implications for vaccine development, and quantifying immunity in populations.

  3. Long-term changes in the surface conditions of PLT

    International Nuclear Information System (INIS)

    Cohen, S.A.; Dylla, H.F.; Rossnagel, S.M.; Picraux, S.T.; Borders, J.A.; Magee, C.W.

    1977-01-01

    Long-term changes in the surface conditions of the PLT vacuum vessel wall have been monitored by the periodic analysis of a variety of sample substrates (stainless steel, alumina, silicon), exposed to PLT discharges for periods of up to several months and subsequently removed for analysis by Auger electron spectroscopy (AES), photoelectron spectroscopy, ion backscattering, nuclear reaction analysis, secondary ion mass spectroscopy, and scanning electron microscopy

  4. Long term kinetic measurements revealing precision and general performance of surface plasmon resonance biosensors.

    Science.gov (United States)

    Steinicke, Franziska; Oltmann-Norden, Imke; Wätzig, Hermann

    2017-08-01

    This work presents an extensive parameter list that facilitates a survey of biosensor performance using Biacore instruments for kinetic binding studies. Six long term measurements were performed using a strongly interacting antigen-antibody (β2 microglobulin) system. Both Single Cycle Kinetic (SCK) and Multi Cycle Kinetic (MCK) were executed each with five different analyte concentrations. The overall comparison of the long term monitored parameters, like the dissociation constant (K D with approximately 3-6% relative percental standard deviation), the association and dissociation rate constants (k a , k d ), the analyte binding capacity (R max ), chi 2 and the sum of the absolute values of the residuals, revealed the delicate factors that make the system performance vulnerable. The main influential factors on kinetic performance were the regeneration conditions, the quality of the sensor surface, the usage time and alteration of the sensor surface, the dilution series and the number of run cycles (about 250-600 per chip). Moreover the direct comparison of MCK and SCK uncovered distinct differences in the accuracy of the K D values. The study of sensor chips from two manufacturers showed distinct differences in the precision of the data. Using control charts for the surveillance of these parameters contributes to an overall better system performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Natural selection promotes antigenic evolvability.

    Science.gov (United States)

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  6. Major role for carbohydrate epitopes preferentially recognized by chronically infected mice in the determination of Schistosoma mansoni schistosomulum surface antigenicity

    International Nuclear Information System (INIS)

    Omer-ali, P.; Magee, A.I.; Kelly, C.; Simpson, A.J.G.

    1986-01-01

    A radioimmunoassay that makes use of whole Schistosomula and 125 I-labeled protein A has been used to characterize and to quantify the binding of antisera to the surface of 3 hr mechanically transformed schistosomula of Schistosoma mansoni. This technique facilitates the determination of epitopes on the schistosomula in addition to those detected by surface labeling and immunoprecipitation. By using this technique, it has been demonstrated that there is a much greater binding to the parasite surface of antibodies from chronically infected mice (CMS) than of antibodies from mice infected with highly irradiated cercariae (VMS), and CMS recognizes epitopes that VMS does not. Treatment of the surface of the schistosomula with trifluoromethanesulphonic acid and sodium metaperiodate has suggested that the discrepancy of the binding between the two sera is due to the recognition of a large number of additional epitopes by CMS, which are carbohydrate in nature. Some of the carbohydrate epitopes are expressed on the previously described surface glycoprotein antigens of M/sub r/ 200,000, 38,000, and 17,000

  7. The role of antigenic stimulation and cytotoxic T cell activity in regulating the long-term immunopathogenesis of HIV: mechanisms and clinical implications

    NARCIS (Netherlands)

    Fraser, C.; Ferguson, N. M.; de Wolf, F.; Anderson, R. M.

    2001-01-01

    This paper develops a predictive mathematical model of cell infection, host immune response and viral replication that reproduces observed long-term trends in human immunodeficiency virus (HIV) pathogenesis. Cell activation induced by repeated exposure to many different antigens is proposed as the

  8. A vaccine prepared from the 22 nm particles of surface hepatitis B antigen (HBsAg)

    International Nuclear Information System (INIS)

    Karelin, V.P.; Babaeva, E.E.; Gubenko, E.F.; Kaulen, D.K.; Zhdanov, V.M.

    1980-01-01

    A method for obtaining a subunit inactivated vaccine preparation from the 22-nm particles of HBsAg is proposed. For inactivation of the residual infectious hepatitis B virus (HBV) the preparations were successively treated with 1% sodium dodecyl sulfate (SDS) and nucleases. In addition, thermal denaturation and ultraviolet irradiation of HBV DNA were used. As a control the biologic activity of a reference virus (SV40) was tested after the same treatment. The effectiveness of DNA inactivation was monitored by adding 3H-thymidine labeled reference virus to the vaccine preparations. The purified and inactivated HBsAg was adsorbed on Al2O3. Antigenicity was calculated on the basis of the determination of antibody in guinea pigs immunized with various doses of the vaccine, and the release of 125 I- HBsAg from blood and kidneys in immunized and control mice was analyzed. Possible methods of inactivation and control of HBV vaccine is discussed

  9. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA) Induce Protective Immune Responses in Dogs

    Science.gov (United States)

    Petitdidier, Elodie; Pagniez, Julie; Papierok, Gérard; Vincendeau, Philippe; Lemesre, Jean-Loup; Bras-Gonçalves, Rachel

    2016-01-01

    Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES) antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA), from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA) or its carboxy terminal part LaPSA-12S (Cter-rPSA), combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates. PMID:27223609

  10. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA) Induce Protective Immune Responses in Dogs.

    Science.gov (United States)

    Petitdidier, Elodie; Pagniez, Julie; Papierok, Gérard; Vincendeau, Philippe; Lemesre, Jean-Loup; Bras-Gonçalves, Rachel

    2016-05-01

    Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES) antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA), from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA) or its carboxy terminal part LaPSA-12S (Cter-rPSA), combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates.

  11. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA Induce Protective Immune Responses in Dogs.

    Directory of Open Access Journals (Sweden)

    Elodie Petitdidier

    2016-05-01

    Full Text Available Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA, from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA or its carboxy terminal part LaPSA-12S (Cter-rPSA, combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates.

  12. Optimized transitory ectopic expression of promastigote surface antigen protein in Nicotiana benthamiana, a potential anti-leishmaniasis vaccine candidate.

    Science.gov (United States)

    Lacombe, Séverine; Bangratz, Martine; Brizard, Jean-Paul; Petitdidier, Elodie; Pagniez, Julie; Sérémé, Drissa; Lemesre, Jean-Loup; Brugidou, Christophe

    2018-01-01

    In recent years, plants have been shown to be an efficient alternative expression system for high-value pharmaceuticals such as vaccines. However, constitutive expression of recombinant protein remains uncertain on their level of production and biological activity. To overcome these problems, transitory expression systems have been developed. Here, a series of experiments were performed to determine the most effective conditions to enhance vaccine antigen transient accumulation in Nicotiana benthamiana leaves using the promastigote surface antigen (PSA) from the parasitic protozoan Leishmania infantum. This protein has been previously identified as the major antigen of a licensed canine anti-leishmaniasis vaccine. The classical prokaryote Escherichia coli biosystem failed in accumulating PSA. Consequently, the standard plant system based on N. benthamiana has been optimized for the production of putatively active PSA. First, the RNA silencing defense mechanism set up by the plant against PSA ectopic expression was abolished by using three viral suppressors acting at different steps of the RNA silencing pathway. Then, we demonstrated that the signal peptide at the N-terminal side of the PSA is required for its accumulation. The PSA ER signaling and retention with the PSA signal peptide and the KDEL motif, respectively were optimized to significantly increase its accumulation. Finally, we demonstrate that the production of recombinant PSA in N. benthamiana leaves allows the conservation of its immunogenic property. These approaches demonstrate that based on these optimizations, plant based systems can be used to effectively produce the biological active PSA protein. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Immunogenicity of a fusion protein comprising coli surface antigen 3 and labile B subunit of enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Alerasol, Masoome; Mousavi Gargari, Seyed Latif; Nazarian, Shahram; Bagheri, Samane

    2014-01-01

    Enterotoxigenic Escherichia coli (ETEC) strains are the major causes of diarrheal disease in humans and animals. Colonization factors and enterotoxins are the major virulence factors in ETEC pathogenesis. For the broad-spectrum protection against ETEC, one could focus on colonization factors and non-toxic heat labile as a vaccine candidate. A fusion protein is composed of a major fimbrial subunit of coli surface antigen 3, and the heat-labile B subunit (LTB) was constructed as a chimeric immunogen. For optimum level expression of protein, the gene was synthesized with codon bias of E. coli. Also, recombinant protein was expressed in E. coli BL21DE3. ELISA and Western tests were carried out for determination of antigen and specificity of antibody raised against recombinant protein in animals. The anti-toxicity and anti-adherence properties of the immune sera against ETEC were also evaluated. Immunological analyses showed the production of high titer of specific antibody in immunized mice. The built-in LTB retains native toxin properties which were approved by GM1 binding assay. Pre-treatment of the ETEC cells with anti-sera significantly decreased their adhesion to Caco-2 cells. The results indicated the efficacy of the recombinant chimeric protein as an effective immunogen inducing strong humoral response. The designated chimer would be an interesting prototype for a vaccine and worthy of further investigation.

  14. A self-amplified transistor immunosensor under dual gate operation: highly sensitive detection of hepatitis B surface antigen

    Science.gov (United States)

    Lee, I.-K.; Jeun, M.; Jang, H.-J.; Cho, W.-J.; Lee, K. H.

    2015-10-01

    Ion-sensitive field-effect transistors (ISFETs), although they have attracted considerable attention as effective immunosensors, have still not been adopted for practical applications owing to several problems: (1) the poor sensitivity caused by the short Debye screening length in media with high ion concentration, (2) time-consuming preconditioning processes for achieving the highly-diluted media, and (3) the low durability caused by undesirable ions such as sodium chloride in the media. Here, we propose a highly sensitive immunosensor based on a self-amplified transistor under dual gate operation (immuno-DG ISFET) for the detection of hepatitis B surface antigen. To address the challenges in current ISFET-based immunosensors, we have enhanced the sensitivity of an immunosensor by precisely tailoring the nanostructure of the transistor. In the pH sensing test, the immuno-DG ISFET showed superior sensitivity (2085.53 mV per pH) to both standard ISFET under single gate operation (58.88 mV per pH) and DG ISFET with a non-tailored transistor (381.14 mV per pH). Moreover, concerning the detection of hepatitis B surface antigens (HBsAg) using the immuno-DG ISFET, we have successfully detected trace amounts of HBsAg (22.5 fg mL-1) in a non-diluted 1× PBS medium with a high sensitivity of 690 mV. Our results demonstrate that the proposed immuno-DG ISFET can be a biosensor platform for practical use in the diagnosis of various diseases.Ion-sensitive field-effect transistors (ISFETs), although they have attracted considerable attention as effective immunosensors, have still not been adopted for practical applications owing to several problems: (1) the poor sensitivity caused by the short Debye screening length in media with high ion concentration, (2) time-consuming preconditioning processes for achieving the highly-diluted media, and (3) the low durability caused by undesirable ions such as sodium chloride in the media. Here, we propose a highly sensitive immunosensor

  15. Antibodies to variable Plasmodium falciparum-infected erythrocyte surface antigens are associated with protection from novel malaria infections

    DEFF Research Database (Denmark)

    Giha, H A; Staalsoe, T; Dodoo, D

    2000-01-01

    is maintained at low densities. Here, we test the hypothesis that the presence or absence of antibodies against variant antigens on the surface of P. falciparum-infected erythrocytes protect individuals against some infectious challenges and render them susceptible to others. Plasma collected in Daraweesh......, eastern Sudan, before and after the malaria season from individuals who had (susceptible) or did not have malaria (protected) during the season, were tested for reactivity against variant antigens on the surface of nine parasite isolates by flow cytometry. Both protected and susceptible individuals...... susceptible and protected individuals. Together, the results indicate that pre-existing anti-PfEMP1 antibodies can reduce the risk of contracting clinical malaria when challenged by novel parasite clones expressing homologous, but not heterologous variable surface antigens. The results also confirm...

  16. Functional and structural changes in human erythrocyte surface after irradiation by UV waves of various wavelengths. Report 1. Expression of ABO and rhesus system antigen

    Energy Technology Data Exchange (ETDEWEB)

    Samoylova, K.A.; Klimova, K.N.; Priezzheva, L.S.; Artsishevskaya, R.A.

    1983-12-01

    To determine whether shortwave UV (SUV) radiation causes changes in the external surface of human erythrocytes, modifying the expression of the ABO and Rh system antigens known to be related to the surface of the cells, work was performed on erythrocytes in a structurally prepared erythrocyte mass from the blood of 23 donors stabilized by glugicir or heparin. Three series of experiments were performed: on isolated erythrocytes, before irradiation thrice washed to remove plasma with isotonic NaCl 0.9% and resuspended at 5 x 10/sup 7/ cells per mililiter; on erythrocytes diluted to 5 x 10/sup 7/ cells per mililiter; and on erythrocytes on the undiluted erythrocyte mass about 7.5 x 10/sup 9/ cells per mililiter. SUV radiation at 254 nm was used at a power of 4.1 W/m/sup 2/ for 1 to 60 minutes. The agglutinating activity of the ABO and Rh antigens was then studied. Two to three hours after exposure to 248, 620, 1240 and 2480 J/m/sup 2/, the degree of hemolysis of isolated erythrocytes increased by 5,10,18 and 28%. Changes were also observed in agglutinating activity of ABO antigens. The agglutinating activity of A and B antigens increased by an average factor of 2 - H antigens by a factor of 4. SUV radiation did not cause any reliable activation of the Rh antigen. 14 references.

  17. Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Shulman, Caroline E; Bulmer, Judith N

    2004-01-01

    BACKGROUND: Pregnancy-associated malaria caused by Plasmodium falciparum adherence to chondroitin sulfate A in the placental intervillous space is a major cause of low birthweight and maternal anaemia in areas of endemic P falciparum transmission. Adhesion-blocking antibodies that specifically...... recognise parasite-encoded variant surface antigens (VSA) are associated with resistance to pregnancy-associated malaria. We looked for a possible relation between VSA-specific antibody concentrations, placental infection, and protection from low birthweight and maternal anaemia. METHODS: We used flow...... cytometry to measure VSA-specific IgG concentrations in plasma samples taken during child birth from 477 Kenyan women selected from a cohort of 910 women on the basis of HIV-1 status, gravidity, and placental histology. We measured VSA expressed by one placental P falciparum isolate and two isolates...

  18. [Possible Involvement of Surface Antigen Protein 2 in the Morphological Transition and Biofilm Formation of Candida albicans].

    Science.gov (United States)

    Okamoto-Shibayama, Kazuko; Kikuchi, Yuichiro; Kokubu, Eitoyo; Ishihara, Kazuyuki

    2017-01-01

    Surface antigen protein 2 (Csa2) is a member of the Candida albicans Common in Fungal Extracellular Membranes (CFEM) protein superfamily. We previously established its role in iron acquisition in C. albicans. However, the other roles of Csa2 remain unknown. Here, we compared growth, morphological transition, and biofilm formation among wild-type, Csa2-mutant, and complemented strains of C. albicans. Deletion of the Csa2 gene resulted in smaller and reduced colony growth, significant attenuation of the dimorphic transition under serum-inducing conditions, and reduced biofilm formation; complementation restored these levels to those of the wild-type. Our findings demonstrated that Csa2 participated in yeast-to-hyphae morphological switching under serum-inducing conditions and contributed to the biofilm formation of C. albicans. This work, therefore, provides novel insights into the potential roles of Csa2 in virulence of C. albicans.

  19. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors

    DEFF Research Database (Denmark)

    Isa, Adiba; Nehlin, Jan; Sabir, Hardee Jawad

    2010-01-01

    HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C...... at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either...... undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC) using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced...

  20. Seroprevalence and risk factors of hepatitis B virus surface antigen among the workers in a garment factory

    Directory of Open Access Journals (Sweden)

    Mohammad Mizanur Rahman

    2017-11-01

    Full Text Available The purpose of this study is to find out the prevalence of seropositivity and risk factors associated with hepatitis B virus infection. A total of 2,737 readymade garment workers were initially screened after getting departmental as well as the individuals consent and simultaneously a questionnaire was filled up by the field research assistants to assess the risk factors. Initially 59 cases were found positive for hepatitis B virus surface antigen (HBsAg by immunochromato-graphic test. Enzyme linked immunosorbant technique was then applied to the screened positive HBsAg individuals and four cases turned out as negative and therefore a total of 55  HBsAg positive cases were detected in this factory. Statistically significant risk factors associated with HBsAg positivity were jaundice, history of previous surgery and accident, needle stick injuries and unsafe injections. This study concludes that the seropositivity found garment workers is similar to the general population of Bangladesh.

  1. Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Shulman, Caroline E; Bulmer, Judith N

    2004-01-01

    BACKGROUND: Pregnancy-associated malaria caused by Plasmodium falciparum adherence to chondroitin sulfate A in the placental intervillous space is a major cause of low birthweight and maternal anaemia in areas of endemic P falciparum transmission. Adhesion-blocking antibodies that specifically...... recognise parasite-encoded variant surface antigens (VSA) are associated with resistance to pregnancy-associated malaria. We looked for a possible relation between VSA-specific antibody concentrations, placental infection, and protection from low birthweight and maternal anaemia. METHODS: We used flow...... selected or not selected for chondroitin sulfate A adhesiveness in-vitro. FINDINGS: Concentrations of plasma IgG specific for VSA, expressed by chondroitin sulfate A-adhering parasites (VSA in pregnancy-associated malaria or vsa-pam), increased with gravidity and were associated with placental histological...

  2. Evaluation of hepatitis B surface antigen and hepatitis B virus-DNA results in postmortem plasma specimens

    Directory of Open Access Journals (Sweden)

    Nihan Ziyade

    2015-03-01

    Full Text Available Objective: To assess the presence of hepatitis B surface antigen, one of the serologic markers of hepatitis B virus (HBV infection, in postmortem blood samples from autopsy cases using ELISA, and to compare the results with those obtained by PCR, which is the gold standard method in assessing HBV infection. Methods: The HBV test results of the blood samples from 880 autopsy cases determined in our laboratory, were retrospectively studied. Results: When compared with the gold standard method PCR, the sensitivity and specificity of postmortem ELISA were 100% and 84.1%, respectively. Conclusions: The increasingly used molecular diagnostic methods, such as PCR, should be used in cases where serological tests remain insufficient.We think that prospective studies on the comparison of ELISA and PCR assessment of postmortem blood samples with larger material should be carried out.

  3. Multiplex flow cytometry barcoding and antibody arrays identify surface antigen profiles of primary and metastatic colon cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Kumar Sukhdeo

    Full Text Available Colon cancer is a deadly disease affecting millions of people worldwide. Current treatment challenges include management of disease burden as well as improvements in detection and targeting of tumor cells. To identify disease state-specific surface antigen signatures, we combined fluorescent cell barcoding with high-throughput flow cytometric profiling of primary and metastatic colon cancer lines (SW480, SW620, and HCT116. Our multiplexed technique offers improvements over conventional methods by permitting the simultaneous and rapid screening of cancer cells with reduced effort and cost. The method uses a protein-level analysis with commercially available antibodies on live cells with intact epitopes to detect potential tumor-specific targets that can be further investigated for their clinical utility. Multiplexed antibody arrays can easily be applied to other tumor types or pathologies for discovery-based approaches to target identification.

  4. Ionizing radiation modulates the surface expression of human leukocyte antigen-G in a human melanoma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Michelin, S.; Gallegos, C.E.; Dubner, D. [Radiopathology Laboratory, Nuclear Regulatory Authority, Buenos Aires (Argentina); Favier, B.; Carosella, E.D. [CEA, I2BM, Hopital Saint-Louis, IUH, Service de Recherches en Hemato-Immunologie, Paris (France)

    2009-07-01

    Human leukocyte antigen G (HLA-G) is a nonclassical HLA class I molecule involved in fetus protection from the maternal immune system, transplant tolerance, and viral and tumoral immune escape. Tumor-specific HLA-G expression has been described for a wide variety of malignancies, including melanomas. The aim of this study was to evaluate whether ionizing radiation (IR) could modulate the surface expression of HLA-G1 in a human melanoma cell line that expresses endogenously membrane-bound HLA-G1. For this purpose, cells were exposed to increasing doses of {gamma}-irradiation (0-20 Gy) and HLA-G1 levels at the plasma membrane were analyzed at different times postirradiation by flow cytometry. HLA-G total expression and the presence of the soluble form of HLA-G1 (sHLA-G1) in the culture medium of irradiated cells were also evaluated. IR was capable of down regulating cell surface and total HLA-G levels, with a concomitant increase of sHLA-G1 in the medium. These results could indicate that {gamma}-irradiation decreases HLA-G1 surface levels by enhancing the proteolytic cleavage of this molecule. (authors)

  5. Cloning of a cDNA encoding a surface antigen of Schistosoma mansoni schistosomula recognized by sera of vassinated mice

    International Nuclear Information System (INIS)

    Dalton, J.P.; Tom, T.D.; Strand, M.

    1987-01-01

    Spleen cells of mice vaccinated with radiation-attenuated Schistosoma mansoni cercariae were used to produce monoclonal antibodies directed against newly transformed schistosomular surface antigens. One of these monoclonal antibodies recognized a polypeptide of 18 kDa. Binding was measured by radioimmunoassay. This glycoprotein was purified by monoclonal antibody immunoaffinity chromatography and a polyclonal antiserum was prepared against it. Immunofluorescence assays showed that the polyclonal antiserum bound to the surface of newly transformed schistosomula and lung-stage organisms but not to the surface of liver-stage and adult worms. Using this polyclonal antiserum we isolated recombinant clones from an adult worm cDNA expression library constructed in λgt11. Clone 654.2 contained an insert of 0.52 kilobase and hybridized to a 1.2-kilobase mRNA species from adult worms. Most importantly, clone 654.2 produced a fusion protein of 125 kDa that was reactive with sera of vaccinated mice that are capable of transferring resistance. This result encourages future vaccination trials with the fusion protein

  6. Assessing stability and assembly of the hepatitis B surface antigen into virus-like particles during down-stream processing.

    Science.gov (United States)

    Zahid, Maria; Lünsdorf, Heinrich; Rinas, Ursula

    2015-07-17

    The hepatitis B surface antigen (HBsAg) is a recombinant protein-based vaccine being able to form virus-like particles (VLPs). HBsAg is mainly produced using yeast-based expression systems, however, recent results strongly suggest that VLPs are not formed within the yeast cells during the cultivation but are formed in a gradual manner during the following down-stream procedures. VLPs are also not detectable during the first down-stream steps including mechanical and EDTA/detergent-assisted cell destruction. Moreover, VLPs are not detectable in the cell lysate treated with polyethylene glycol and colloidal silica. The first VLP resembling structures appear after elution of HBsAg from colloidal silica to which it binds through hydrophobic interaction. These first VLP resembling structures are non-symmetrical as well as heterodisperse and exhibit a high tendency toward cluster formation presumably because of surface exposed hydrophobic patches. More symmetrical and monodisperse VLPs appear after the following ion-exchange and size-exclusion chromatography most likely as the result of buffer changes during these purification steps (toward more neutral pH and less salt). Final treatment of the VLPs with the denaturant KSCN at moderate concentrations with following KSCN removal by dialysis does not cause unfolding and VLP disassembly but results in a re- and fine-structuring of the VLP surface topology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. A new technique to detect antibody-antigen reaction (biological interactions) on a localized surface plasmon resonance (LSPR) based nano ripple gold chip

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, Iram, E-mail: iiram.qau@gmail.com [Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 (United States); Widger, William, E-mail: widger@uh.edu [Department of Biology and Biochemistry and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 (United States); Chu, Wei-Kan, E-mail: wkchu@uh.edu [Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 (United States)

    2017-07-31

    Highlights: • The nano ripple LSPR chip has monolayer molecule-coating sensitivity and specific selectivity. • Gold nano-ripple sensing chip is a low cost, and a label-free method for detecting the antibody-antigen reaction. • The plasmonic resonance shift depends upon the concentration of the biomolecules attached on the surface of the nano ripple pattern. - Abstract: We demonstrate that the gold nano-ripple localized surface plasmon resonance (LSPR) chip is a low cost and a label-free method for detecting the presence of an antigen. A uniform stable layer of an antibody was coated on the surface of a nano-ripple gold pattern chip followed by the addition of different concentrations of the antigen. A red shift was observed in the LSPR spectral peak caused by the change in the local refractive index in the vicinity of the nanostructure. The LSPR chip was fabricated using oblique gas cluster ion beam (GCIB) irradiation. The plasmon-resonance intensity of the scattered light was measured by a simple optical spectroscope. The gold nano ripple chip shows monolayer scale sensitivity and high selectivity. The LSPR substrate was used to detect antibody-antigen reaction of rabbit X-DENTT antibody and DENTT blocking peptide (antigen).

  8. Driving forces for the adsorption of a His-tag Chagas antigen. A rational approach to design bio-functional surfaces.

    Science.gov (United States)

    Valenti, Laura E; Smania, Andrea M; De Pauli, Carlos P; Giacomelli, Carla E

    2013-12-01

    In order to rationally design a bio-functional surface based on the adsorption of a His-tag antigen, three requirements have to be considered: the bio-recognition element, the driving forces for the adsorption process and the detection mode of the bio-recognition event. This work is focused on the study of the adsorption mechanism of the His-tag H49 Chagas antigen on Ni(II) modified substrates. In order to construct the bio-functional surface, the gen of the H49 Chagas antigen was modified to incorporate His6 moiety at the N-terminal (His6-H49). Then, its physical adsorption and bio-affinity interaction with the solid substrate was studied by reflectometry. Besides His-Ni(II) bio-affinity interactions, His6-H49 was also physically adsorbed on Ni(II) modified substrates, leading to randomly oriented antigens. These loosely attached bio-molecules were partially removed using conditions of electrostatic repulsion. On the other hand, bio-affinity interactions, resulting in site-oriented molecules on the substrate, were only removable by specific competitors for Ni(II) surface sites. Finally, the surface bio-activity was determined from the peak separations of voltammetry waves due to the change of the electron transfer kinetics of a redox probe through the bio-functional surface (working electrode). Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Modelling of long term nitrogen retention in surface waters

    Science.gov (United States)

    Halbfaß, S.; Gebel, M.; Bürger, S.

    2010-12-01

    In order to derive measures to reduce nutrient loadings into waters in Saxony, we calculated nitrogen inputs with the model STOFFBILANZ on the regional scale. Thereby we have to compare our modelling results to measured loadings at the river basin outlets, considering long term nutrient retention in surface waters. The most important mechanism of nitrogen retention is the denitrification in the contact zone of water and sediment, being controlled by hydraulic and micro-biological processes. Retention capacity is derived on the basis of the nutrient spiralling concept, using water residence time (hydraulic aspect) and time-specific N-uptake by microorganisms (biological aspect). Short time related processes of mobilization and immobilization are neglected, because they are of minor importance for the derivation of measures on the regional scale.

  10. Quantitative analysis of rat Ig (sub)classes binding to cell surface antigens

    International Nuclear Information System (INIS)

    Nilsson, R.; Brodin, T.; Sjoegren, H.-O.

    1982-01-01

    An indirect 125 I-labeled protein A assay for detection of cell surface-bound rat immunoglobulins is presented. The assay is quantitative and rapid and detects as little as 1 ng of cell surface-bound Ig. It discriminates between antibodies belonging to different IgG subclasses, IgM and IgA. The authors describe the production and specificity control of the reagents used and show that the test can be used for quantitative analysis. A large number of sera from untreated rats are tested to evaluate the frequency of falsely positive responses and variation due to age, sex and strain of rat. With this test it is relatively easy to quantitate the binding of classes and subclasses of rat immunoglobulins in a small volume (6 μl) of untreated serum. (Auth.)

  11. Antigen 43-mediated autotransporter display, a versatile bacterial cell surface presentation system

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Hasman, Henrik; Schembri, Mark

    2002-01-01

    to the outer membrane and secretion through the cell envelope is contained within the protein itself. Ag43 consists of two subunits (alpha and beta), where the beta-subunit forms an integral outer membrane translocator to which the alpha-subunit is noncovalently attached. The simplicity of the Ag43 system...... makes it ideally suited as a surface display scaffold. Here we demonstrate that the Ag43 alpha-module can accommodate and display correctly folded inserts and has the ability to display entire functional protein domains, exemplified by the FimH lectin domain. The presence of heterologous cysteine...... bridges does not interfere with surface display, and Ag43 chimeras are correctly processed into alpha- and beta-modules, offering optional and easy release of the chimeric alpha-subunits. Furthermore, Ag43 can be displayed in many gram-negative bacteria. This feature is exploited for display of our...

  12. Correlation between two chemiluminescence based assays for quantification of hepatitis B surface antigen in patients with chronic hepatitis B infection

    Directory of Open Access Journals (Sweden)

    E Gupta

    2015-01-01

    Full Text Available Purpose: Hepatitis B surface Antigen (HBsAg is the hallmark in diagnosing hepatitis B virus (HBV infection. In India many commercial assays are available for detection of HBsAg but very few can measure it quantitatively. The present study presents the comparative evaluation of two methods and their correlation with serum HBsAg in chronic hepatitis B (CHB patients. Materials and Methods: Consecutive patients of CHB were included and there HBsAg levels were measured by two methods: (i Elecsys, Roche Diagnostics, a qualitative assay and (ii Architect, Abbott Diagnostics, a quantitative assay. The HBV DNA was measured by real-time polymerase chain reaction (qPCR. Results: Total of 136 patients were included in the study and there was a significant overall correlation between both the assays (correlation coefficient [r] = 0.83; P < 0.001. Assays correlated well with each other across all subgroups of CHB: treatment naοve (r = 0.73; P < 0.001, n = 32, on treatment (r = 0.56; P < 0.05, n = 104, hepatitis Be (HBe antigen positive (r = 0.67; P < 0.001, n = 62 and anti-HBe positive (r = 0.61; P < 0.05, n = 74 group. On correlation with serum HBV DNA, Architect assay demonstrated good correlation (r = 0.73; P < 0.001, n = 136 as compared to the Elecsys assay (r = 0.27; P = 0.068, n = 136. Architect HBsAg QT assay (A1 also correlated well with HBV DNA in the treatment naοve group (r = 0.69; P < 0.001, n = 32. Conclusions: Our study hence proved that both the assays are comparable and a simple qualitative assay with in-house modification can be used easily for quatitation of HBsAg in clinical samples.

  13. Protective vaccination with promastigote surface antigen 2 from Leishmania major is mediated by a TH1 type of immune response.

    Science.gov (United States)

    Handman, E; Symons, F M; Baldwin, T M; Curtis, J M; Scheerlinck, J P

    1995-11-01

    Leishmania major promastigote surface antigen-2 complex (PSA-2) comprises a family of three similar but distinct polypeptides. The three PSA-2 polypeptides were purified from cultured promastigotes by a combination of detergent phase separation and monoclonal antibody affinity chromatography. Intraperitoneal vaccination of C3H/He mice with PSA-2 with Corynebacterium parvum as an adjuvant resulted in complete protection from lesion development after challenge infection with virulent L. major. Significant protection was also obtained in the genetically susceptible BALB/cH-2k and BALB/c mice. One of the PSA-2 genes was cloned and expressed in both Escherichia coli and Leishmania mexicana promastigotes. Vaccination with the recombinant PSA-2 purified from E. coli did not confer protection, in contrast to the L. mexicana-derived recombinant PSA-2, which provided excellent protection. CD4+ T cells isolated from the spleens of vaccinated mice produced large amounts of gamma interferon but no detectable interleukin 4 upon stimulation with PSA-2 in vitro. Limiting dilution analysis showed a marked increase in the precursor frequency of PSA-2-specific gamma interferon-secreting CD4+ T cells. No substantial change in precursor frequency was observed for interleukin 4-secreting T cells in the vaccinated mice. A CD4+ PSA-2 specific T-cell line generated from splenocytes of a vaccinated mouse produces a cytokine pattern consistent with a TH1 phenotype. Intravenous injection of this line into naive mice reduced significantly the parasite burden upon challenge infection. Taken together, the data suggest that vaccination with PSA-2 induces a TH1 type of immune response which protects mice from L. major infection. Moreover, a single recombinant PSA-2 polypeptide derived from a genomic clone can also vaccinate, provided that the structural form of the antigen is near native.

  14. Long-term changes in the surface conditions of PLT

    International Nuclear Information System (INIS)

    Cohen, S.A.; Dylla, H.F.; Rossnagel, S.M.; Picraux, S.T.; Borders, J.A.; Magee, C.W.

    1978-06-01

    Long-term changes in the surface conditions of the PLT vacuum vessel wall have been monitoried by the periodic analysis of a variety of sample substrates (stainless steel, alumina, silicon), exposed to PLT discharges for periods of up to several months and subsequently removed for analysis by Auger electron spectroscopy (AES), photoelectron spectroscopy (ESCA), ion backscattering, nuclear reaction analysis, secondary ion mass spectrometry (SIMS), and scanning electron microscopy. Samples exposed for extended time periods (2 to 6 months) showed deposited films containing limiter (W) and liner constituent metals (Fe, Cr, and Ni) and C and O. The film thicknesses ranged between 100 to 200 A with 2 to 15 atomic percent W and 5 to 40 percent Fe as determined by sputter-AES and ion backscattering measurements. Increased deposition of metallic impurities (W, Fe) was noted following the first extensive application of low power discharge cleaning. We discuss possible mechanisms responsible for the deposition of metals onto the sample surfaces. Deuterium retention was observed in all the exposed samples with the deuterium depth profiles restricted primarily to the deposited films on the stainless steel substrates and extending deeper for Si. The deuterium retained in the exposed samples shows a saturation at (1 to 11) x 10 15 D atoms/cm 2 for an estimated variation in the deuterium fluence of 10 17 to 10 19 D atoms/cm 2

  15. Plasmodium falciparum parasites expressing pregnancy-specific variant surface antigens adhere strongly to the choriocarcinoma cell line BeWo

    DEFF Research Database (Denmark)

    Haase, Rikke N; Megnekou, Rosette; Lundquist, Maja

    2006-01-01

    Placenta-sequestering Plasmodium falciparum parasites causing pregnancy-associated malaria express pregnancy-specific variant surface antigens (VSA(PAM)). We report here that VSA(PAM)-expressing patient isolates adhere strongly to the choriocarcinoma cell line BeWo and that the BeWo line can...... be used to efficiently select for VSA(PAM) expression in vitro....

  16. The neural cell adhesion molecule L1 is distinct from the N-CAM related group of surface antigens BSP-2 and D2

    DEFF Research Database (Denmark)

    Faissner, A; Kruse, J; Goridis, C

    1984-01-01

    The neural cell adhesion molecule L1 and the group of N-CAM related molecules, BSP-2 and D2 antigen, are immunochemically distinct molecular species. The two groups of surface molecules are also functionally distinct entities, since inhibition of Ca2+-independent adhesion among early post-natal m...

  17. Expression of variant surface antigens by Plasmodium falciparum parasites in the peripheral blood of clinically immune pregnant women indicates ongoing placental infection

    DEFF Research Database (Denmark)

    Ofori, Michael F; Staalsoe, Trine; Bam, Victoria

    2003-01-01

    Placenta-sequestered Plasmodium falciparum parasites that cause pregnancy-associated malaria (PAM) in otherwise clinically immune women express distinct variant surface antigens (VSA(PAM)) not expressed by parasites in nonpregnant individuals. We report here that parasites from the peripheral blood...

  18. Characterization of the antigenicity of Cpl1, a surface protein of Cryptococcus neoformans var. neoformans.

    Science.gov (United States)

    Cai, Jian-Piao; Liu, Ling-Li; To, Kelvin K W; Lau, Candy C Y; Woo, Patrick C Y; Lau, Susanna K P; Guo, Yong-Hui; Ngan, Antonio H Y; Che, Xiao-Yan; Yuen, Kwok-Yung

    2015-01-01

    Cryptococcus neoformans var. neoformans is an important fungal pathogen. The capsule is a well established virulence factor and a target site for diagnostic tests. The CPL1 gene is required for capsular formation and virulence. The protein product Cpl1 has been proposed to be a secreted protein, but the characteristics of this protein have not been reported. Here we sought to characterize Cpl1. Phylogenetic analysis showed that the Cpl1 of C. neoformans var. neoformans and the Cpl1 orthologs identified in C. neoformans var. grubii and C. gattii formed a distinct cluster among related fungi; while the putative ortholog found in Trichosporon asahii was distantly related to the Cryptococcus cluster. We expressed Cpl1 abundantly as a secreted His-tagged protein in Pichia pastoris. The protein was used to immunize guinea pigs and rabbits for high titer mono-specific polyclonal antibody that was shown to be highly specific against the cell wall of C. neoformans var. neoformans and did not cross react with C. gattii, T. asahii, Aspergillus spp., Candida spp. and Penicillium spp. Using the anti-Cpl1 antibody, we detected Cpl1 protein in the fresh culture supernatant of C. neoformans var. neoformans and we showed by immunostaining that the Cpl1 protein was located on the surface. The Cpl1 protein is a specific surface protein of C. neoformans var. neoformans. © 2015 by The Mycological Society of America.

  19. The promastigote surface antigen gene family of the Leishmania parasite: differential evolution by positive selection and recombination

    OpenAIRE

    Bañuls Anne-Laure; Devault Alain

    2008-01-01

    Abstract Background PSA (promastigote surface antigen) is one of the major classes of membrane proteins present at the surface of the parasitic protozoan Leishmania. While it harbours leucine rich repeats, which are suggestive of its involvement in parasite-to-host physical interactions, its exact role is largely unknown. Furthermore, the extent of diversity of this gene family, both in copy number and sequence has not been established. Results From the newly available complete genome sequenc...

  20. Mechanisms of recurrent otitis media: importance of the immune response to bacterial surface antigens.

    Science.gov (United States)

    Murphy, T F; Yi, K

    1997-12-29

    Otitis-prone children experience recurrent episodes of otitis media due to nontypeable H. influenzae (NTHI). A protective immune response occurs following infection, but this immune response is specific for the infecting strain, leaving the child susceptible to infection by other strains of NTHI. Little is known about the mechanism by which a strain-specific antibody response occurs to nonencapsulated bacteria. To explore the mechanism by which this strain-specific response occurs, animals were inoculated with whole bacterial cells and the antibody response was studied. The antibody response was predominantly directed to a highly strain-specific, immunodominant surface loop on the major outer membrane protein. This exquisitely restricted immune response leaves the host susceptible to recurrent infections by many strains of NTHI. The ability of the bacterium to direct the host to make a strain-specific antibody response has important implications in understanding the immune response to otitis media due to NTHI and in designing strategies for vaccine development.

  1. An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens

    Directory of Open Access Journals (Sweden)

    Márcia Cristina Aquino Teixeira

    2011-03-01

    Full Text Available Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.

  2. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major

    DEFF Research Database (Denmark)

    Kemp, M; Handman, E; Kemp, K

    1998-01-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune......-beta, and little interleukin-4, thereby showing a Th1 cytokine pattern. Parallel cultures showed clear Th1 and Th2 response patterns to purified protein derivative of tuberculin or tetanus toxoid, respectively. Flow cytometric analysis revealed that PSA-2 induced blastogenesis in the CD3 positive population...... and that these cells were the major source of interferon-gamma. The results show that Th1-like cells recognising PSA-2 are expanded during infection by L. major and that they maintain their Th1-like cytokine profile upon reactivation in vitro. Since immunity to cutaneous leishmaniasis is mediated by antigen...

  3. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major

    DEFF Research Database (Denmark)

    Kemp, M; Handman, E; Kemp, K

    1998-01-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune...... to cutaneous leishmaniasis. Peripheral blood mononuclear cells from Sudanese individuals with a past history of self-healing cutaneous leishmaniasis proliferated vigorously in response to PSA-2 isolated from Leishmania major, whereas the antigen did not activate cells from presumably unexposed Danes....... Peripheral blood mononuclear cells from individuals with previous L. major infection had varying proliferative responses to PSA-2 derived from L. donovani promastigotes. Peripheral blood mononuclear cells activated by PSA-2 from L. major produced high amounts of interferon-gamma and tumour necrosis factor...

  4. Long-term consequences of radioactive surface contamination in agriculture

    International Nuclear Information System (INIS)

    Haak, E.

    1983-01-01

    Based on agricultural statistics of crop and animal produce for 1981, and on transfer coefficients, as obtained from long-term Swedish field experiments and the literature, the transfer of 137-Cs and 90-Sr within the chain: Soil crop - food, and the chain: soil - crop - animal - food was estimated for an average km 2 of farming land in nine different countries, with the assumption that 1 TBq had been deposited at a single event and remained near the surface of grass fields and/or had been incorporated into the plough layer of arable soils prior to reuse after a nuclear accident. Calculations are given in detail, and the results are discussed as regards the situation of unchanged farming and soil management practices. The transfer of the two nuclides from soil to different vectors within the two chains was shown to vary among the countries, due to differences in soil, use of pasture and an arable land, as well as current plant and animal produce. The transfer of nuclides from fodder to food is effectively reduced by the animal link and more so for strontium than for cesium. The contamination recirculates back to the soil. The effect of corrective measures to reduce nuclide transfer from soil to food, by changed fertilizer and soil management practices as well as changes from current farming systems to pig or beef cattle

  5. Evolutionary structure of Plasmodium falciparum major variant surface antigen genes in South America: Implications for epidemic transmission and surveillance.

    Science.gov (United States)

    Rougeron, Virginie; Tiedje, Kathryn E; Chen, Donald S; Rask, Thomas S; Gamboa, Dionicia; Maestre, Amanda; Musset, Lise; Legrand, Eric; Noya, Oscar; Yalcindag, Erhan; Renaud, François; Prugnolle, Franck; Day, Karen P

    2017-11-01

    Strong founder effects resulting from human migration out of Africa have led to geographic variation in single nucleotide polymorphisms (SNPs) and microsatellites (MS) of the malaria parasite, Plasmodium falciparum . This is particularly striking in South America where two major founder populations of P. falciparum have been identified that are presumed to have arisen from the transatlantic slave trade. Given the importance of the major variant surface antigen of the blood stages of P. falciparum as both a virulence factor and target of immunity, we decided to investigate the population genetics of the genes encoding " Plasmodium falciparum Erythrocyte Membrane Protein 1" ( Pf EMP1) among several countries in South America, in order to evaluate the transmission patterns of malaria in this continent. Deep sequencing of the DBLα domain of var genes from 128 P. falciparum isolates from five locations in South America was completed using a 454 high throughput sequencing protocol. Striking geographic variation in var DBLα sequences, similar to that seen for SNPs and MS markers, was observed. Colombia and French Guiana had distinct var DBLα sequences, whereas Peru and Venezuela showed an admixture. The importance of such geographic variation to herd immunity and malaria vaccination is discussed.

  6. A molecular assembly system for presentation of antigens on the surface of HBc virus-like particles

    Energy Technology Data Exchange (ETDEWEB)

    Blokhina, Elena A.; Kuprianov, Victor V. [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); Stepanova, Ludmila A.; Tsybalova, Ludmila M. [Research Institute of Influenza, Russian Federation Ministry of Health and Social Development, St. Petersburg (Russian Federation); Kiselev, Oleg I. [Research Institute of Influenza, Russian Federation Ministry of Health and Social Development, St. Petersburg (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation); Ravin, Nikolai V., E-mail: nravin@biengi.ac.ru [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation); Skryabin, Konstantin G. [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation)

    2013-01-20

    Hepatitis B virus-like particles, icosahedral structures formed by multiple core protein dimers, are promising immune-enhancing vaccine carriers for foreign antigens. Insertions into the surface-exposed immunodominant loop are especially immunogenic. However, the need to conserve the particulate structure to ensure high immunogenicity imposes restraints on the nature of the heterologous sequence that can be inserted. We propose a new approach to constructing HBc particles linked to the target epitopes that relies on non-covalent interactions between the epitope and pre-assembled unmodified HBc particles. Interaction was enabled by fusion of the epitope to the GSLLGRMKGA peptide, binding to the spike tips. This peptide may be used as a 'binding tag' allowing in vitro construction of HBc particles carrying the target peptide. Such virus-like particles carrying multiple copies of the extracellular domain of the M2 protein of different influenza strains appeared to be highly immunogenic and protected immunised mice against a lethal influenza challenge.

  7. Prevalence of hepatitis B virus surface antigen (HBsAg) in patients undergoing extraction at the University College Hospital, Ibadan.

    Science.gov (United States)

    Odaibo, G N; Arotiba, J T; Fasola, A O; Obiechina, A E; Olaleye, O D; Ajagbe, H A

    2003-09-01

    Hepatitis B Virus (HBV) infection and its sequelae (liver chirrhosis and hepatic carcinoma) are endemic in Africa. The risk of transmission of the infection during dental treatment is real. This study was carried out to determine the rate of Hepatits B Surface Antigen (HBsAg) as a marker of hepatitis B virus infection in patients undergoing dental extraction in order to highlight the potential risk of nosocomial transmission among the Dental Health Workers (DHW) and their patients. Three hundred (143 males and 157 females) consecutive patients requiring dental extraction who volunteered were enrolled into this study. Their ages ranged from 11 years to 95 years with a mean of 37.2 years (SD = 16.725) and a median of 36 years. The overall HBsAg infection rate was 18.3% (55/300). A higher infection rate (23.1%) occurred among the male patients compared with 14% in females (p = 0.0086). The high rate of HBV infection found among this study population suggests that Dental Surgeons in this environment have a high risk of exposure to hepatitis B virus and should be immunized at the beginning of their professional life. Universal biosafety measures should be observed strictly in all invasive procedures.

  8. Hepatitis B Vaccination Coverage and Prevalence of Hepatitis B Surface Antigen Among Children in French Polynesia, 2014.

    Science.gov (United States)

    Patel, Minal K; Le Calvez, Evelyne; Wannemuehler, Kathleen; Ségalin, Jean-Marc

    2016-06-01

    French Polynesia is considered to be moderately endemic for chronic hepatitis B virus infection, with an estimated 3% of the population having hepatitis B surface antigen (HBsAg). From 1990 to 1992, a 3-dose hepatitis B vaccination series was introduced into the routine infant immunization schedule in French Polynesia, including a birth dose (BD). In 2014, a nationally representative 2-stage cluster survey was undertaken to evaluate the impact of the vaccination program on HBsAg prevalence among school children (∼6 years of age) in Cours Préparatoire (CP). Documented vaccination data were reviewed for all eligible children; children with consent were tested for HBsAg with a rapid point-of-care test. In total, 1,660 students were identified; 1,567 (94%) had vaccination data for review and 1,196 (72%) participated in the serosurvey. Three-dose vaccination coverage was 98%, while timely BD coverage, defined as a dose administered within 24 hours of life, was 89%. Receipt of the second and third doses was often delayed, with 75% and 55% receiving a second and third dose within 1 month of the recommended age, respectively. No children tested positive for HBsAg. French Polynesia's vaccination program has achieved high coverage and an HBsAg seroprevalence of 0% (0-0.5%) among CP school children, but timeliness of vaccination could be improved. © The American Society of Tropical Medicine and Hygiene.

  9. Characterization of surface antigen protein 1 (SurA1) from Acinetobacter baumannii and its role in virulence and fitness.

    Science.gov (United States)

    Liu, Dong; Liu, Zeng-Shan; Hu, Pan; Cai, Ling; Fu, Bao-Quan; Li, Yan-Song; Lu, Shi-Ying; Liu, Nan-Nan; Ma, Xiao-Long; Chi, Dan; Chang, Jiang; Shui, Yi-Ming; Li, Zhao-Hui; Ahmad, Waqas; Zhou, Yu; Ren, Hong-Lin

    2016-04-15

    Acinetobacter baumannii is a Gram-negative bacillus that causes nosocomial infections, such as bacteremia, pneumonia, and meningitis and urinary tract and wound infections. In the present study, the surface antigen protein 1 (SurA1) gene of A. baumannii strain CCGGD201101 was identified, cloned and expressed, and then its roles in fitness and virulence were investigated. Virulence was observed in the human lung cancer cell lines A549 and HEp-2 at one week after treatment with recombinant SurA1. One isogenic SurA1 knock-out strain, GR0015, which was derived from the A. baumannii strain CCGGD201101 isolated from diseased chicks in a previous study, highlighted the effect of SurA1 on fitness and growth. Its growth rate in LB broth and killing activity in human sera were significantly decreased compared with strain CCGGD201101. In the Galleria mellonella insect model, the isogenic SurA1 knock-out strain exhibited a lower survival rate and decreased dissemination. These results suggest that SurA1 plays an important role in the fitness and virulence of A. baumannii. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Establishment of an in vivo potency assay for the recombinant hepatit is B surface antigen in monovalent and combined vaccines

    Directory of Open Access Journals (Sweden)

    Mabel Izquierdo-López

    2014-12-01

    Full Text Available In this paper the development of potency assay in animals (mice was made, with the objective of demonstrating the immunogenic power of the recombinant Hepatitis B surface antigen in monovalent and combined vaccines, produced at the Center of Genetic Engineering and Biotechnology. The potency test is a parameter in quality control and it is also a tool to demonstrate the consistency of the production process. Parameters such as duration of the test, number of animals in the test, as well as different areas for the maintenance of the animals were evaluated. The results on the applicability of the potency test, to two presentations of the vaccines; monovalent Heberbiovac HB and pentavalent liquid in one vial Heberpenta-L are shown, for which specificity studies, evaluating different vaccine lots, the behavior of linearity, and parallelism, as well as establishing quality specification of the test were performed. This assay led to the obtainment of reliable results for the vaccines evaluated, the consistent evaluation of the immunogenic power and the monitoring of different production processes.

  11. Pectinesterase Inhibitor from Jelly Fig (Ficus awkeotsang Makino Achene Inhibits Surface Antigen Expression by Human Hepatitis B Virus

    Directory of Open Access Journals (Sweden)

    Yu-Chuen Huang

    2013-01-01

    Full Text Available Pectinesterase inhibitor (PEI isolated from jelly fig (Ficus awkeotsang Makino is an edible component of a popular drink consumed in Asia. Hepatitis B virus (HBV infection is prevalent in Asia, and current treatments for HBV infection need improvement. This study aimed to evaluate the effect of PEI on the surface antigen expression by HBV (HBsAg. Human hepatoma cell lines Hep3B and Huh7 served as in vitro models for assessing the cytotoxicity and HBsAg expression. A culture of primary hepatocytes cultured from mice served as the normal counterpart. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT colorimetric assay. HBsAg expression was evaluated by measuring HBsAg secretion into the culture medium using an enzyme-linked immunosorbent assay. The results showed that PEI did not affect the viability of the human hepatoma cell lines or primary mouse hepatocytes. PEI inhibited the expression of HBsAg in hepatoma cell lines harboring endogenous (Hep3B and integrated (Huh7 HBV genomes in a concentration- and time-dependent manner, thus implicating a universal activity against HBV gene expression. In conclusion, it suggests that PEI from jelly fig inhibits the expression of human HBsAg in host cells without toxic effects on normal primary hepatocytes.

  12. Pectinesterase Inhibitor from Jelly Fig (Ficus awkeotsang Makino) Achene Inhibits Surface Antigen Expression by Human Hepatitis B Virus.

    Science.gov (United States)

    Huang, Yu-Chuen; Jiang, Chii-Ming; Chen, Yu-Jen; Chen, Yu-Yawn

    2013-01-01

    Pectinesterase inhibitor (PEI) isolated from jelly fig (Ficus awkeotsang Makino) is an edible component of a popular drink consumed in Asia. Hepatitis B virus (HBV) infection is prevalent in Asia, and current treatments for HBV infection need improvement. This study aimed to evaluate the effect of PEI on the surface antigen expression by HBV (HBsAg). Human hepatoma cell lines Hep3B and Huh7 served as in vitro models for assessing the cytotoxicity and HBsAg expression. A culture of primary hepatocytes cultured from mice served as the normal counterpart. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. HBsAg expression was evaluated by measuring HBsAg secretion into the culture medium using an enzyme-linked immunosorbent assay. The results showed that PEI did not affect the viability of the human hepatoma cell lines or primary mouse hepatocytes. PEI inhibited the expression of HBsAg in hepatoma cell lines harboring endogenous (Hep3B) and integrated (Huh7) HBV genomes in a concentration- and time-dependent manner, thus implicating a universal activity against HBV gene expression. In conclusion, it suggests that PEI from jelly fig inhibits the expression of human HBsAg in host cells without toxic effects on normal primary hepatocytes.

  13. Prevalence of Hepatitis B core antibodies with negative Hepatitis B surface antigen in dialysis and chronic kidney disease patients

    Directory of Open Access Journals (Sweden)

    Nauman Tarif

    2017-01-01

    Full Text Available Occult hepatitis B infection (OBI is a potential cause of infection transmission in patients with chronic kidney disease (CKD and dialysis-dependant patients. It is liable to be missed since the marker for OBI, hepatitis B core antibody (HBcAb, is not done routinely. We carried out a study to assess the prevalence of OBI in CKD Stage II–V or requiring renal replacement therapy. It was a cross-sectional study carried out at Fatima Memorial Hospital, Lahore, from May 2104 to May 2015. A total of 188 patients were included in this study, 124 were dialysis dependent and 64 had acute or CKD Stage II–V. About 17.55% (n = 33 of patients had isolated HBcAb positive. Nearly 33.5% (n = 63 of patients were found to have hepatitis B surface antigen positive, indicating development of immunity by exposure to virus. About 20.74% (n = 39 of patients were co-positive with HBcAb also. The prevalence of isolated HBcAb in dialysis and CKD patients is high; therefore, testing for HBcAb should be a routine part of screening in our CKD population to rule out OBI. Further confirmation with polymerase chain reaction analysis for HBV viral DNA is recommended. Considering our circumstances, a consensus statement from the hepatologists and nephrologists is needed to further plan for the management of such cases.

  14. Safety of using hepatitis B virus core antibody or surface antigen-positive donors in kidney or pancreas transplantation.

    Science.gov (United States)

    Akalin, Enver; Ames, Scott; Sehgal, Vinita; Murphy, Barbara; Bromberg, Jonathan S

    2005-06-01

    Hepatitis B virus core antibody (HBcAb) or surface antigen (HBsAg)-positive organ donors have the potential to transmit infection to transplant recipients. We investigated the safety of using HBcAb(+) or HBsAg(+) donors in kidney or pancreas transplant recipients with 1 yr lamivudine prophylaxis. While HBsAb(-) recipients of HBcAb(+) donors received prophylaxis, HBsAb(+) recipients did not. HBsAg(+) organs were only used in patients who were both HBcAb and HBsAb(+). Forty-six patients received HBcAb(+) and four received HBsAg(+) organs (47 kidney, two pancreas, and one kidney/pancreas). All but one recipient were HBsAg(-), 25 were HBsAb(+), and 19 HBcAb(+). During a median 36 months of follow-up (range 6-66 months), with 43 of a total 50 patients having at least 1 yr follow-up and were off lamivudine, and none of the patients developed hepatitis B viremia or seroconversion to HBsAg or HBsAb(+). These results suggest that HBcAb(+) or HBsAg(+) organs can be used safely in selected recipients with lamivudine prophylaxis without requiring hepatitis B immunglobulin.

  15. Prevalence of Hepatitis B core antibodies with negative Hepatitis B surface antigen in dialysis and chronic kidney disease patients.

    Science.gov (United States)

    Tarif, Nauman; Riaz, Muhammad Mohsin; Sabir, Omer; Akhter, Rizwan; Rafique, Kashif; Rizvi, Nabiha

    2017-01-01

    Occult hepatitis B infection (OBI) is a potential cause of infection transmission in patients with chronic kidney disease (CKD) and dialysis-dependant patients. It is liable to be missed since the marker for OBI, hepatitis B core antibody (HBcAb), is not done routinely. We carried out a study to assess the prevalence of OBI in CKD Stage II-V or requiring renal replacement therapy. It was a cross-sectional study carried out at Fatima Memorial Hospital, Lahore, from May 2104 to May 2015. A total of 188 patients were included in this study, 124 were dialysis dependent and 64 had acute or CKD Stage II-V. About 17.55% (n = 33) of patients had isolated HBcAb positive. Nearly 33.5% (n = 63) of patients were found to have hepatitis B surface antigen positive, indicating development of immunity by exposure to virus. About 20.74% (n = 39) of patients were co-positive with HBcAb also. The prevalence of isolated HBcAb in dialysis and CKD patients is high; therefore, testing for HBcAb should be a routine part of screening in our CKD population to rule out OBI. Further confirmation with polymerase chain reaction analysis for HBV viral DNA is recommended. Considering our circumstances, a consensus statement from the hepatologists and nephrologists is needed to further plan for the management of such cases.

  16. Nonstructural Protein 4 of Porcine Reproductive and Respiratory Syndrome Virus Modulates Cell Surface Swine Leukocyte Antigen Class I Expression by Downregulating β2-Microglobulin Transcription.

    Science.gov (United States)

    Qi, Pengfei; Liu, Ke; Wei, Jianchao; Li, Yuming; Li, Beibei; Shao, Donghua; Wu, Zhuanchang; Shi, Yuanyuan; Tong, Guangzhi; Qiu, Yafeng; Ma, Zhiyong

    2017-03-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is the causative agent of PRRS, which has important impacts on the pig industry. PRRSV infection results in disruption of the swine leukocyte antigen class I (SLA-I) antigen presentation pathway. In this study, highly pathogenic PRRSV (HP-PRRSV) infection inhibited transcription of the β2-microglobulin (β2M) gene ( B2M ) and reduced cellular levels of β2M, which forms a heterotrimeric complex with the SLA-I heavy chain and a variable peptide and plays a critical role in SLA-I antigen presentation. HP-PRRSV nonstructural protein 4 (Nsp4) was involved in the downregulation of β2M expression. Exogenous expression of Nsp4 downregulated β2M expression at both the mRNA and the protein level and reduced SLA-I expression on the cell surface. Nsp4 bound to the porcine B2M promoter and inhibited its transcriptional activity. Domain III of Nsp4 and the enhancer PAM element of the porcine B2M promoter were identified as essential for the interaction between Nsp4 and B2M These findings demonstrate a novel mechanism whereby HP-PRRSV may modulate the SLA-I antigen presentation pathway and provide new insights into the functions of HP-PRRSV Nsp4. IMPORTANCE PRRSV modulates the host response by disrupting the SLA-I antigen presentation pathway. We show that HP-PRRSV downregulates SLA-I expression on the cell surface via transcriptional inhibition of B2M expression by viral Nsp4. The interaction between domain III of Nsp4 and the enhancer PAM element of the porcine B2M promoter is essential for inhibiting B2M transcription. These observations reveal a novel mechanism whereby HP-PRRSV may modulate SLA-I antigen presentation and provide new insights into the functions of viral Nsp4. Copyright © 2017 American Society for Microbiology.

  17. Long-term Maintenance of CD4 T Cell Memory Responses to Malaria Antigens in Malian Children Coinfected with Schistosoma haematobium

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    Kirsten E. Lyke

    2018-02-01

    Full Text Available Polyparasitism is common in the developing world. We have previously demonstrated that schistosomiasis-positive (SP Malian children, aged 4–8 years, are protected from malaria compared to matched schistosomiasis-negative (SN children. The effect of concomitant schistosomiasis upon acquisition of T cell memory is unknown. We examined antigen-specific T cell frequencies in 48 Malian children aged 4–14 to a pool of malaria blood stage antigens, and a pool of schistosomal antigens, at a time point during a malaria episode and at a convalescent time point ~6 months later, following cessation of malaria transmission. CD4+ T cell-derived memory responses, defined as one or more significant cytokine (IFN-γ, TNF-α, IL-2, and/or IL-17A responses, was measured to schistoma antigens in 18/23 SP children at one or both time points, compared to 4/23 SN children (P < 0.0001. At the time of malaria infection, 12/24 SN children and 15/23 SP children (P = 0.29 stimulated with malaria antigens demonstrated memory recall as defined by CD4-derived cytokine production. This compares to 7/23 SN children and 16/23 SP children (P = 0.009 at the convalescent timepoint. 46.2% of cytokine-producing CD4+ T cells expressed a single cytokine after stimulation with malaria antigen during the malaria episode. This fell to 40.9% at follow-up with a compensatory rise of multifunctional cytokine secretion over time, a phenomenon consistent with memory maturation. The majority (53.2–59.5% of responses derived from CD45RA−CD62L− effector memory T cells with little variation in the phenotype depending upon the time point or the study cohort. We conclude that detectable T cell memory responses can be measured against both malaria and schistosoma antigens and that the presence of Schistosoma haematobium may be associated with long-term maintenance of T memory to malaria.

  18. In Vitro Variant Surface Antigen Expression in Plasmodium falciparum Parasites from a Semi-Immune Individual Is Not Correlated with Var Gene Transcription

    Science.gov (United States)

    Tschan, Serena; Flötenmeyer, Matthias; Koch, Iris; Berger, Jürgen; Kremsner, Peter; Frank, Matthias

    2016-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is considered to be the main variant surface antigen (VSA) of Plasmodium falciparum and is mainly localized on electron-dense knobs in the membrane of the infected erythrocyte. Switches in PfEMP1 expression provide the basis for antigenic variation and are thought to be critical for parasite persistence during chronic infections. Recently, strain transcending anti-PfEMP1 immunity has been shown to develop early in life, challenging the role of PfEMP1 in antigenic variation during chronic infections. In this work we investigate how P. falciparum achieves persistence during a chronic asymptomatic infection. The infected individual (MOA) was parasitemic for 42 days and multilocus var gene genotyping showed persistence of the same parasite population throughout the infection. Parasites from the beginning of the infection were adapted to tissue culture and cloned by limiting dilution. Flow cytometry using convalescent serum detected a variable surface recognition signal on isogenic clonal parasites. Quantitative real-time PCR with a field isolate specific var gene primer set showed that the surface recognition signal was not correlated with transcription of individual var genes. Strain transcending anti-PfEMP1 immunity of the convalescent serum was demonstrated with CD36 selected and PfEMP1 knock-down NF54 clones. In contrast, knock-down of PfEMP1 did not have an effect on the antibody recognition signal in MOA clones. Trypsinisation of the membrane surface proteins abolished the surface recognition signal and immune electron microscopy revealed that antibodies from the convalescent serum bound to membrane areas without knobs and with knobs. Together the data indicate that PfEMP1 is not the main variable surface antigen during a chronic infection and suggest a role for trypsin sensitive non-PfEMP1 VSAs for parasite persistence in chronic infections. PMID:27907004

  19. In Vitro Evaluation of a Soluble Leishmania Promastigote Surface Antigen as a Potential Vaccine Candidate against Human Leishmaniasis

    Science.gov (United States)

    Bahi-Jaber, Narges; Petitdidier, Elodie; Markikou-Ouni, Wafa; Aoun, Karim; Moreno, Javier; Carrillo, Eugenia; Salotra, Poonam; Kaushal, Himanshu; Negi, Narender Singh; Arevalo, Jorge; Falconi-Agapito, Francesca; Privat, Angela; Cruz, Maria; Pagniez, Julie; Papierok, Gérard-Marie; Rhouma, Faten Bel Haj; Torres, Pilar; Lemesre, Jean-Loup; Chenik, Mehdi; Meddeb-Garnaoui, Amel

    2014-01-01

    PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb) or visceral leishmaniasis due to L. donovani (CVLd) and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection) or non immune/naive individuals (HLR: Healthy Low Responders), depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection. PMID:24786587

  20. In vitro evaluation of a soluble Leishmania promastigote surface antigen as a potential vaccine candidate against human leishmaniasis.

    Science.gov (United States)

    Chamakh-Ayari, Rym; Bras-Gonçalves, Rachel; Bahi-Jaber, Narges; Petitdidier, Elodie; Markikou-Ouni, Wafa; Aoun, Karim; Moreno, Javier; Carrillo, Eugenia; Salotra, Poonam; Kaushal, Himanshu; Negi, Narender Singh; Arevalo, Jorge; Falconi-Agapito, Francesca; Privat, Angela; Cruz, Maria; Pagniez, Julie; Papierok, Gérard-Marie; Rhouma, Faten Bel Haj; Torres, Pilar; Lemesre, Jean-Loup; Chenik, Mehdi; Meddeb-Garnaoui, Amel

    2014-01-01

    PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb) or visceral leishmaniasis due to L. donovani (CVLd) and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection) or non immune/naive individuals (HLR: Healthy Low Responders), depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection.

  1. In vitro evaluation of a soluble Leishmania promastigote surface antigen as a potential vaccine candidate against human leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Rym Chamakh-Ayari

    Full Text Available PSA (Promastigote Surface Antigen belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L. species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm or L. braziliensis (CCLb or visceral leishmaniasis due to L. donovani (CVLd and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection or non immune/naive individuals (HLR: Healthy Low Responders, depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection.

  2. Vaccination with liposomal leishmanial antigens adjuvanted with monophosphoryl lipid-trehalose dicorynomycolate (MPL-TDM) confers long-term protection against visceral leishmaniasis through a human administrable route.

    Science.gov (United States)

    Ravindran, Rajesh; Maji, Mithun; Ali, Nahid

    2012-01-01

    The development of a long-term protective subunit vaccine against visceral leishmaniasis depends on antigens and adjuvants that can induce an appropriate immune response. The immunization of leishmanial antigens alone shows limited efficacy in the absence of an appropriate adjuvant. Earlier we demonstrated sustained protection against Leishmania donovani with leishmanial antigens entrapped in cationic liposomes through an intraperitoneal route. However, this route is not applicable for human administration. Herein, we therefore evaluated the immune response and protection induced by liposomal soluble leishmanial antigen (SLA) formulated with monophosphoryl lipid-trehalose dicorynomycolate (MPL-TDM) through a subcutaneous route. Subcutaneous immunization of BALB/c mice with SLA entrapped in liposomes or with MPL-TDM elicited partial protection against experimental visceral leishmaniasis. In contrast, liposomal SLA adjuvanted with MPL-TDM induced significantly higher levels of protection in liver and spleen in BALB/c mice challenged 10 days post-vaccination. Protection conferred by this formulation was sustained up to 12 weeks of immunization, and infection was controlled for at least 4 months of the challenge, similar to liposomal SLA immunization administered intraperitoneally. An analysis of cellular immune responses of liposomal SLA + MPL-TDM immunized mice demonstrated the induction of IFN-γ and IgG2a antibody production not only 10 days or 12 weeks post-vaccination but also 4 months after the challenge infection and a down regulation of IL-4 production after infection. Moreover, long-term immunity elicited by this formulation was associated with IFN-γ production also by CD8⁺ T cells. Taken together, our results suggest that liposomal SLA + MPL-TDM represent a good vaccine formulation for the induction of durable protection against L. donovani through a human administrable route.

  3. Limited polymorphism in Plasmodium falciparum ookinete surface antigen, von Willebrand factor A domain-related protein from clinical isolates

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    Eisen Damon P

    2006-07-01

    Full Text Available Abstract Background As malaria becomes increasingly drug resistant and more costly to treat, there is increasing urgency to develop effective vaccines. In comparison to other stages of the malaria lifecycle, sexual stage antigens are under less immune selection pressure and hence are likely to have limited antigenic diversity. Methods Clinical isolates from a wide range of geographical regions were collected. Direct sequencing of PCR products was then used to determine the extent of polymorphisms for the novel Plasmodium falciparum sexual stage antigen von Willebrand Factor A domain-related Protein (PfWARP. These isolates were also used to confirm the extent of diversity of sexual stage antigen Pfs28. Results PfWARP was shown to have non-synonymous substitutions at 3 positions and Pfs28 was confirmed to have a single non-synonymous substitution as previously described. Conclusion This study demonstrates the limited antigenic diversity of two prospective P. falciparum sexual stage antigens, PfWARP and Pfs28. This provides further encouragement for the proceeding with vaccine trials based on these antigens.

  4. Limited polymorphism in Plasmodium falciparum ookinete surface antigen, von Willebrand factor A domain-related protein from clinical isolates.

    Science.gov (United States)

    Richards, Jack S; MacDonald, Nicholas J; Eisen, Damon P

    2006-07-05

    As malaria becomes increasingly drug resistant and more costly to treat, there is increasing urgency to develop effective vaccines. In comparison to other stages of the malaria lifecycle, sexual stage antigens are under less immune selection pressure and hence are likely to have limited antigenic diversity. Clinical isolates from a wide range of geographical regions were collected. Direct sequencing of PCR products was then used to determine the extent of polymorphisms for the novel Plasmodium falciparum sexual stage antigen von Willebrand Factor A domain-related Protein (PfWARP). These isolates were also used to confirm the extent of diversity of sexual stage antigen Pfs28. PfWARP was shown to have non-synonymous substitutions at 3 positions and Pfs28 was confirmed to have a single non-synonymous substitution as previously described. This study demonstrates the limited antigenic diversity of two prospective P. falciparum sexual stage antigens, PfWARP and Pfs28. This provides further encouragement for the proceeding with vaccine trials based on these antigens.

  5. Heteroassembled gold nanoparticles with sandwich-immunoassay LSPR chip format for rapid and sensitive detection of hepatitis B virus surface antigen (HBsAg).

    Science.gov (United States)

    Kim, Jinwoon; Oh, Seo Yeong; Shukla, Shruti; Hong, Seok Bok; Heo, Nam Su; Bajpai, Vivek K; Chun, Hyang Sook; Jo, Cheon-Ho; Choi, Bong Gill; Huh, Yun Suk; Han, Young-Kyu

    2018-06-01

    This study aimed to develop a more sensitive method for the detection of hepatitis B surface antigen (HBsAg) using heteroassembled gold nanoparticles (AuNPs). A single layered localized surface plasmon resonance (LSPR) chip format was developed with antigen-antibody reaction-based detection symmetry using AuNPs, which detected HBsAg at 10 pg/mL. To further improve the detection limit, a modified detection format was fabricated by fixing a secondary antibody (to form a heteroassembled sandwich format) to the AuNP monolayer, which enhanced the detection sensitivity by about 100 times. The developed heteroassembled AuNPs sandwich-immunoassay LSPR chip format was able to detect as little as 100 fg/mL of HBsAg within 10-15 min. In addition, the heteroassembled AuNPs sandwich-immunoassay LSPR chip format did not show any non-specific binding to other tested antigens, including alpha fetoprotein (AFP), C-reactive protein (CRP), and prostate-specific antigen (PSA). These findings confirm that the proposed detection strategy of heteroassembled AuNPs sandwich-immunoassay LSPR chip format may provide a new platform for early diagnosis of various human diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Studies on the surface antigenicity and susceptibility to antibody-dependent killing of developing schistosomula using sera from chronically infected mice and mice vaccinated with irradiated cercariae

    International Nuclear Information System (INIS)

    Bickle, Q.D.; Ford, M.J.

    1982-01-01

    Changes in the surface antigenicity and susceptibility to in vitro killing during development of schistosomula of Schistosoma mansoni were studied using serum from chronically infected mice (CIS) and from mice vaccinated with highly irradiated (20 krad) cercariae (VS). Binding of these sera was quantitated by counting the number of P388D 1 cells (a transformed, macrophage-like cell of mouse origin, bearing Fc receptors for IgG) binding to the parasite surface. Compared with schistosomula derived in vitro by mechanical transformation (MS), schistosomula recovered 3 hr after skin penetration in vitro (SS) showed a significant loss in surface binding of CIS. Schistosomula recovered 3 hr after skin penetration in vivo (SRS) showed even less binding, and this trend continued such that parasites recovered from the lungs 5 days after infection (LS) showed only minimal binding, and 10-day-old worms from the portal system showed no significant binding. In contrast, VS, which bound significantly less well to MS than CIS, showed enhanced binding to SS, and in the face of their declining antigenicity with respect to CIS, 3- to 24-hr SRS maintained this raised level of antigenicity. Although there appeared to be a decline in binding of VS thereafter, LS remained antigenic, still binding as many cells as MS did despite the fact that they also expressed host antigens detected usng antisera raised against mouse RBC. In spite of this persistence of VS binding up to the lung stage, resistance to eosinophil-mediated killing in vitro had developed by 48 hr post-infection, and LS were totally resistant to both eosinophil- and C-mediated killing

  7. Stem Cell Physics. Laser Manipulation of Blood Types: Laser-Stripping-Away of Red Blood Cell Surface Antigens

    Science.gov (United States)

    Stefan, V. Alexander

    2014-03-01

    A novel mechanism of importance for the transfusion medicine[2] is proposed. The interaction of ultrashort wavelength multilaser beams with the flowing blood thin films can lead to a conversion of blood types A, B, and AB into O type.[3] The stripping away of antigens is done by the scanning-multiple-lasers of a high repetition rate in the blue-purple frequency domain. The guiding-lasers are in the red-green frequency domain. The laser force, (parametric interaction with the antigen eigen-oscillation),[4] upon the antigen protein molecule must exceed its weight. Supported by Nikola Tesla Labs, La Jolla, CA.

  8. The promastigote surface antigen gene family of the Leishmania parasite: differential evolution by positive selection and recombination.

    Science.gov (United States)

    Devault, Alain; Bañuls, Anne-Laure

    2008-10-24

    PSA (promastigote surface antigen) is one of the major classes of membrane proteins present at the surface of the parasitic protozoan Leishmania. While it harbours leucine rich repeats, which are suggestive of its involvement in parasite-to-host physical interactions, its exact role is largely unknown. Furthermore, the extent of diversity of this gene family, both in copy number and sequence has not been established. From the newly available complete genome sequences of L. major, L. infantum and L. braziliensis, we have established the complete list of PSA genes, based on the conservation of specific domain architecture. The latter includes an array of leucine rich repeats of unique signature flanked by conserved cysteine-rich domains. All PSA genes code either for secreted or membrane-anchored surface proteins. Besides the few previously identified PSA genes, which are shown here to be part of a relatively large subclass of PSA genes located on chromosome 12, this study identifies seven other PSA subtypes. The latter, whose genes lie on chromosomes 5, 9, 21 and 31 in all three species, form single gene (two genes in one instance) subfamilies, which phylogenetically cluster as highly related orthologs. On the other hand, genes found on chromosome 12 generally show high diversification, as reflected in greater sequence divergence between species, and in an extended set of divergent paralogs. Moreover, we show that the latter genes are submitted to strong positive selection. We also provide evidence that evolution of these genes is driven by intra- and intergenic recombination, thereby modulating the number of LRRs in protein and generating chimeric genes. PSA is a Leishmania family of membrane-bound or secreted proteins, whose main signature consists in a specific LRR sequence. All PSA genes found in the genomes of three sequenced Leishmania species unambiguously distribute into eight subfamilies of orthologs. Seven of these are evolving relatively slowly and could

  9. The promastigote surface antigen gene family of the Leishmania parasite: differential evolution by positive selection and recombination

    Directory of Open Access Journals (Sweden)

    Bañuls Anne-Laure

    2008-10-01

    Full Text Available Abstract Background PSA (promastigote surface antigen is one of the major classes of membrane proteins present at the surface of the parasitic protozoan Leishmania. While it harbours leucine rich repeats, which are suggestive of its involvement in parasite-to-host physical interactions, its exact role is largely unknown. Furthermore, the extent of diversity of this gene family, both in copy number and sequence has not been established. Results From the newly available complete genome sequences of L. major, L. infantum and L. braziliensis, we have established the complete list of PSA genes, based on the conservation of specific domain architecture. The latter includes an array of leucine rich repeats of unique signature flanked by conserved cysteine-rich domains. All PSA genes code either for secreted or membrane-anchored surface proteins. Besides the few previously identified PSA genes, which are shown here to be part of a relatively large subclass of PSA genes located on chromosome 12, this study identifies seven other PSA subtypes. The latter, whose genes lie on chromosomes 5, 9, 21 and 31 in all three species, form single gene (two genes in one instance subfamilies, which phylogenetically cluster as highly related orthologs. On the other hand, genes found on chromosome 12 generally show high diversification, as reflected in greater sequence divergence between species, and in an extended set of divergent paralogs. Moreover, we show that the latter genes are submitted to strong positive selection. We also provide evidence that evolution of these genes is driven by intra- and intergenic recombination, thereby modulating the number of LRRs in protein and generating chimeric genes. Conclusion PSA is a Leishmania family of membrane-bound or secreted proteins, whose main signature consists in a specific LRR sequence. All PSA genes found in the genomes of three sequenced Leishmania species unambiguously distribute into eight subfamilies of orthologs

  10. Interferon-alpha-induced changes in surface antigens in a hairy-cell leukemia (JOK-1), and a Burkitt's lymphoma cell line (Daudi) during in vitro culture

    DEFF Research Database (Denmark)

    Nielsen, B; Madsen, P S; Jensen, A W

    1992-01-01

    In further studying the mechanism of action of IFN-alpha in HCL, we cultured the HCL cell line JOK-1 and the IFN-sensitive Burkitt cell line Daudi with and without IFN-alpha and investigated the changes in density of a number of surface antigens by use of mAb and flow cytometry analyses. During...... culture with IFN-alpha, reproducible changes were induced in both cell lines, which were qualitatively similar but differed quantitatively with small and transient changes in JOK-1. Significant decreases in surface antigen expression were observed for CD 19, 23, 37, and for IgM on both cell lines...... of IFN-alpha in HCL was not paralleled by a specific direct effect on JOK-1 in vitro. Our findings therefore do not support the theory that IFN's mechanism of action in vivo is a direct effect on HC, but suggest that indirect effects are involved. Udgivelsesdato: 1992-Mar...

  11. A simple and inexpensive point-of-care test for hepatitis B surface antigen detection: serological and molecular evaluation.

    Science.gov (United States)

    Gish, R G; Gutierrez, J A; Navarro-Cazarez, N; Giang, K; Adler, D; Tran, B; Locarnini, S; Hammond, R; Bowden, S

    2014-12-01

    Early identification of chronic hepatitis B is important for optimal disease management and prevention of transmission. Cost and lack of access to commercial hepatitis B surface antigen (HBsAg) immunoassays can compromise the effectiveness of HBV screening in resource-limited settings and among marginalized populations. High-quality point-of-care (POC) testing may improve HBV diagnosis in these situations. Currently available POC HBsAg assays are often limited in sensitivity. We evaluated the NanoSign(®) HBs POC chromatographic immunoassay for its ability to detect HBsAg of different genotypes and with substitutions in the 'a' determinant. Thirty-seven serum samples from patients with HBV infection, covering HBV genotypes A-G, were assessed for HBsAg titre with the Roche Elecsys HBsAg II quantification assay and with the POC assay. The POC assay reliably detected HBsAg at a concentration of at least 50 IU/mL for all genotypes, and at lower concentrations for some genotypes. Eight samples with substitutions in the HBV 'a' determinant were reliably detected after a 1/100 dilution. The POC strips were used to screen serum samples from 297 individuals at risk for HBV in local clinical settings (health fairs and outreach events) in parallel with commercial laboratory HBsAg testing (Quest Diagnostics EIA). POC testing was 73.7% sensitive and 97.8% specific for detection of HBsAg. Although the POC test demonstrated high sensitivity over a range of genotypes, false negatives were frequent in a clinical setting. Nevertheless, the POC assay offers advantages for testing in both developed and resource-limited countries due to its low cost (0.50$) and immediately available results. © 2014 John Wiley & Sons Ltd.

  12. Construction and expression of hepatitis B surface antigen escape variants within the "a" determinant by site directed mutagenesis.

    Science.gov (United States)

    Golsaz Shirazi, Forough; Amiri, Mohammad Mehdi; Mohammadi, Hamed; Bayat, Ali Ahmad; Roohi, Azam; Khoshnoodi, Jalal; Zarnani, Amir Hassan; Jeddi-Tehrani, Mahmood; Kardar, Gholam Ali; Shokri, Fazel

    2013-09-01

    The antibody response to hepatitis B surface antigen (HBsAg) controls hepatitis B virus infection. The "a" determinant of HBsAg is the most important target for protective antibody response, diagnosis and immunoprophylaxis. Mutations in this area may induce immune escape mutants and affect the performance of HBsAg assays. To construct clinically relevant recombinant mutant forms of HBsAg and assessment of their reactivity with anti-HBs monoclonal antibodies (MAbs). Wild type (wt) and mutant (mt) HBsAg genes were constructed by site directed mutagenesis and SEOing PCR. The amplified genes were inserted into pCMV6-neo plasmid and transfected in CHO cell line. The expression of wt- and mtHBsAg was assessed by commercial ELISA assays and stable cells were established and cloned by limiting dilution. The recombinant mutants were further characterized using a panel of anti-HBs monoclonal antibodies (MAbs) and the pattern of their reactivity was assessed by ELISA. Ten HBsAg mutants having single mutation within the "a" determinant including P120E, T123N, Q129H, M133L, K141E, P142S, D144A, G145R, N146S and C147S together with a wt form were successfully constructed and expressed in CHO cells. Reactivity of anti-HBs MAbs with mtHBsAgs displayed different patterns. The effect of mutations on antibody binding differed depending on the amino acid involved and its location within the ''a'' determinant. Mutation at amino acids 123 and 145 resulted in either complete loss or significant reduction of binding to all anti-HBs MAbs. Our panel of mtHBsAgs is a valuable tool for assessment of the antibody response to HBV escape mutants and may have substantial implications in HBV immunological diagnostics.

  13. Hepatocellular carcinoma. A study of 50 autopsy cases with detection of hepatitis B surface antigen in fixed tissues.

    Science.gov (United States)

    Perez-Barrios, A; Colina-Ruizdelgado, F; Gallego, I; Martinez-Tello, F J

    1983-03-01

    Fifty patients who died of hepatocellular carcinoma (HCC) were autopsied at the Ciudad Sanitaria "1 degree de Octubre" and the Hospital de la Cruz Roja (Madrid) from 1974 to 1980. Formalin fixed paraffin-embedded autopsy tissue of liver and tumor from the 50 HCC and liver tissue from 50 liver cirrhosis (LC) and from 50 autopsy of non cirrhotic control cases were examined for the presence of cytoplasmic hepatitis B surface antigen (HBsAg). The study was carried out using orcein staining, immunoperoxidase technique (IP) and indirect immunofluorescence (IF). In livers with HCC the HBsAg was detected in the cytoplasm of the hepatocytes in 10 cases (20%) with the orcein staining and in 11 (22%) with the IP and IF techniques. In one case (2%) HBsAg was found in the cytoplasm of tumor cells with the three methods--In four cases (8%) of LC and 2 (4%) control cases cytoplasmic positive cells were found. In 41 patients with HCC HBsAg was studied in the serum by radio-immunoassay (RIA) (13 cases) and immunodiffussion (28 cases). 5 patients (12,1%) were positive and 36 (72%) were negative. In the 5 serum positive HBsAg HCC the staining methods for cytoplasmic HBsAg were positive (100%). In 36 serum negative HBsAg HCC the staining method were positive in 2 cases. The results let us to conclude that HBV is a probable important etiologic factor of HCC in our milieu. 54% of the patients with HCC had a previous history of alcohol abuse; however, histologic features compatible with an alcoholic etiology were found in only 5 cases. Nevertheless we consider that the described histopathologic findings do not exclude excess alcohol consumption as a possible etiologic factor for HCC in our series.

  14. Analysis of complete genome sequence and major surface antigens of Neorickettsia helminthoeca, causative agent of salmon poisoning disease.

    Science.gov (United States)

    Lin, Mingqun; Bachman, Katherine; Cheng, Zhihui; Daugherty, Sean C; Nagaraj, Sushma; Sengamalay, Naomi; Ott, Sandra; Godinez, Al; Tallon, Luke J; Sadzewicz, Lisa; Fraser, Claire; Dunning Hotopp, Julie C; Rikihisa, Yasuko

    2017-07-01

    Neorickettsia helminthoeca, a type species of the genus Neorickettsia, is an endosymbiont of digenetic trematodes of veterinary importance. Upon ingestion of salmonid fish parasitized with infected trematodes, canids develop salmon poisoning disease (SPD), an acute febrile illness that is particularly severe and often fatal in dogs without adequate treatment. We determined and analysed the complete genome sequence of N. helminthoeca: a single small circular chromosome of 884 232 bp encoding 774 potential proteins. N. helminthoeca is unable to synthesize lipopolysaccharides and most amino acids, but is capable of synthesizing vitamins, cofactors, nucleotides and bacterioferritin. N. helminthoeca is, however, distinct from majority of the family Anaplasmataceae to which it belongs, as it encodes nearly all enzymes required for peptidoglycan biosynthesis, suggesting its structural hardiness and inflammatory potential. Using sera from dogs that were experimentally infected by feeding with parasitized fish or naturally infected in southern California, Western blot analysis revealed that among five predicted N. helminthoeca outer membrane proteins, P51 and strain-variable surface antigen were uniformly recognized. Our finding will help understanding pathogenesis, prevalence of N. helminthoeca infection among trematodes, canids and potentially other animals in nature to develop effective SPD diagnostic and preventive measures. Recent progresses in large-scale genome sequencing have been uncovering broad distribution of Neorickettsia spp., the comparative genomics will facilitate understanding of biology and the natural history of these elusive environmental bacteria. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  15. Expression of variant surface antigens by Plasmodium falciparum parasites in the peripheral blood of clinically immune pregnant women indicates ongoing placental infection

    DEFF Research Database (Denmark)

    Ofori, Michael F; Staalsoe, Trine; Bam, Victoria

    2003-01-01

    Placenta-sequestered Plasmodium falciparum parasites that cause pregnancy-associated malaria (PAM) in otherwise clinically immune women express distinct variant surface antigens (VSA(PAM)) not expressed by parasites in nonpregnant individuals. We report here that parasites from the peripheral blood...... of clinically immune pregnant women also express VSA(PAM), making them a convenient source of VSA(PAM) expressors for PAM vaccine research....

  16. Surface co-expression of two different PfEMP1 antigens on single Plasmodium falciparum-infected erythrocytes facilitates binding to ICAM1 and PECAM1

    DEFF Research Database (Denmark)

    Joergensen, Louise; Bengtsson, Dominique C; Bengtsson, Anja

    2010-01-01

    gene is expressed per cell at a time. We measured var mRNA transcript levels by real-time Q-PCR, analysed var gene transcripts by single-cell FISH and directly compared these with PfEMP1 antigen surface expression and cytoadhesion in three different antibody-selected P. falciparum 3D7 sub-lines using...... was found to bind both CD31/PECAM1 and CD54/ICAM1 and to adhere twice as efficiently to human endothelial cells, compared to infected cells having only one PfEMP1 variant on the surface. These new results on PfEMP1 antigen expression indicate that a re-evaluation of the molecular mechanisms involved in P...... live confocal microscopy, flow cytometry and in vitro adhesion assays. We found that one selected parasite sub-line simultaneously expressed two different var genes as surface antigens, on single IE. Importantly, and of physiological relevance to adhesion and malaria pathogenesis, this parasite sub-line...

  17. An Extended Surface Loop on Toxoplasma gondii Apical Membrane Antigen 1 (AMA1 Governs Ligand Binding Selectivity.

    Directory of Open Access Journals (Sweden)

    Michelle L Parker

    Full Text Available Apicomplexan parasites are the causative agents of globally prevalent diseases including malaria and toxoplasmosis. These obligate intracellular pathogens have evolved a sophisticated host cell invasion strategy that relies on a parasite-host cell junction anchored by interactions between apical membrane antigens (AMAs on the parasite surface and rhoptry neck 2 (RON2 proteins discharged from the parasite and embedded in the host cell membrane. Key to formation of the AMA1-RON2 complex is displacement of an extended surface loop on AMA1 called the DII loop. While conformational flexibility of the DII loop is required to expose the mature RON2 binding groove, a definitive role of this substructure has not been elucidated. To establish a role of the DII loop in Toxoplasma gondii AMA1, we engineered a form of the protein where the mobile portion of the loop was replaced with a short Gly-Ser linker (TgAMA1ΔDIIloop. Isothermal titration calorimetry measurements with a panel of RON2 peptides revealed an influential role for the DII loop in governing selectivity. Most notably, an Eimeria tenella RON2 (EtRON2 peptide that showed only weak binding to TgAMA1 bound with high affinity to TgAMA1ΔDIIloop. To define the molecular basis for the differential binding, we determined the crystal structure of TgAMA1ΔDIIloop in complex with the EtRON2 peptide. When analyzed in the context of existing AMA1-RON2 structures, spatially distinct anchor points in the AMA1 groove were identified that, when engaged, appear to provide the necessary traction to outcompete the DII loop. Collectively, these data support a model where the AMA1 DII loop serves as a structural gatekeeper to selectively filter out ligands otherwise capable of binding with high affinity in the AMA1 apical groove. These data also highlight the importance of considering the functional implications of the DII loop in the ongoing development of therapeutic intervention strategies targeting the AMA1-RON

  18. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major.

    Science.gov (United States)

    Kemp, M; Handman, E; Kemp, K; Ismail, A; Mustafa, M D; Kordofani, A Y; Bendtzen, K; Kharazmi, A; Theander, T G

    1998-03-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune to cutaneous leishmaniasis. Peripheral blood mononuclear cells from Sudanese individuals with a past history of self-healing cutaneous leishmaniasis proliferated vigorously in response to PSA-2 isolated from Leishmania major, whereas the antigen did not activate cells from presumably unexposed Danes. Peripheral blood mononuclear cells from individuals with previous L. major infection had varying proliferative responses to PSA-2 derived from L. donovani promastigotes. Peripheral blood mononuclear cells activated by PSA-2 from L. major produced high amounts of interferon-gamma and tumour necrosis factor-beta, and little interleukin-4, thereby showing a Th1 cytokine pattern. Parallel cultures showed clear Th1 and Th2 response patterns to purified protein derivative of tuberculin or tetanus toxoid, respectively. Flow cytometric analysis revealed that PSA-2 induced blastogenesis in the CD3 positive population and that these cells were the major source of interferon-gamma. The results show that Th1-like cells recognising PSA-2 are expanded during infection by L. major and that they maintain their Th1-like cytokine profile upon reactivation in vitro. Since immunity to cutaneous leishmaniasis is mediated by antigen-specific Th1-like cells, PSA-2 might be considered a vaccine candidate for human leishmaniasis.

  19. New candidate vaccines against blood-stage Plasmodium falciparum malaria: prime-boost immunization regimens incorporating human and simian adenoviral vectors and poxviral vectors expressing an optimized antigen based on merozoite surface protein 1

    NARCIS (Netherlands)

    Goodman, Anna L.; Epp, C.; Moss, D.; Holder, A. A.; Wilson, J. M.; Gao, G. P.; Long, C. A.; Remarque, E. J.; Thomas, A. W.; Ammendola, V.; Colloca, S.; Dicks, M. D. J.; Biswas, S.; Seibel, D.; van Duivenvoorde, L. M.; Gilbert, S. C.; Hill, A. V. S.; Draper, S. J.

    2010-01-01

    Although merozoite surface protein 1 (MSP-1) is a leading candidate vaccine antigen for blood-stage malaria, its efficacy in clinical trials has been limited in part by antigenic polymorphism and potentially by the inability of protein-in-adjuvant vaccines to induce strong cellular immunity. Here we

  20. Changing serum levels of quantitative hepatitis B surface antigen and hepatitis B virus DNA in hepatitis B virus surface antigen carriers: A follow-up study of an elderly cohort

    Directory of Open Access Journals (Sweden)

    Yuan-Hung Kuo

    2015-02-01

    Full Text Available This study was to elucidate longitudinally quantitative changes of hepatitis B virus (HBV surface antigen (HBsAg and HBV DNA in elder HBsAg carriers in a community. Among 1002 residents screened for HBsAg in 2005, 405 responded to this follow-up study in 2010. Fifty-nine (14.6% were HBsAg carriers in 2005; HBsAg quantification and HBV DNA were measured. HBsAg quantification (cutoff 1600 IU/mL and HBV DNA (cutoff 2000 IU/mL were combined to stratify the participants between two screens. A total of 30 men and 29 women with a mean age of 63.9 ± 7.9 years were enrolled. Quantitative levels of HBsAg and HBV DNA were significantly correlated in 2005 (r = 0.509, p < 0.001 and 2010 (r = 0.777, p < 0.001. Concentrations of HBsAg (IU/mL significantly decreased from 2.2 ± 1.0 log in 2005 to 1.7 ± 1.5 log in 2010 (p < 0.001. The level of HBsAg was decreased in 48 (81.4% individuals and HBsAg was undetectable in eight (13.6%. The annual incidence of HBsAg clearance was 2.7%. These 59 HBsAg carriers in 2005 were divided into four groups: low HBsAg low HBV DNA (n = 32, high HBsAg low HBV DNA (n = 5, low HBsAg high HBV DNA (n = 12 and high HBsAg high HBV DNA (n = 10. All 32 individuals in the low HBsAg low HBV DNA group were still in that group in 2010, whereas only two of the high HBsAg high HBV DNA group became inactive. As with a younger cohort in hospital, HBsAg quantification was still well correlated with HBV DNA in elderly HBsAg carriers in the community. Lower levels of both HBsAg and HBV DNA might represent an inactive HBV infection.

  1. Modelled long term trends of surface ozone over South Africa

    CSIR Research Space (South Africa)

    Naidoo, M

    2011-10-01

    Full Text Available timescale seeks to provide a spatially comprehensive view of trends while also creating a baseline for comparisons with future projections of air quality through the forcing of air quality models with modelled predicted long term meteorology. Previous...

  2. Anisotropic In Situ-Coated AuNPs on Screen-Printed Carbon Surface for Enhanced Prostate-Specific Antigen Impedimetric Aptasensor

    Science.gov (United States)

    Do, Tram T. N.; Van Phi, Toan; Nguy, Tin Phan; Wagner, Patrick; Eersels, Kasper; Vestergaard, Mun'delanji C.; Truong, Lien T. N.

    2017-06-01

    An impedimetric aptasensor has been used to study the effect of charge transfer on the binding of prostate-specific antigen (PSA) to its aptamer. Full understanding of this mechanism will be beneficial to further improve its sensitivity for PSA detection in human semen at physiologically relevant concentrations. Bare gold electrodes (SPAuEs) and gold nanoparticles (AuNPs)-coated screen-printed carbon ink electrodes (AuNPs/SPCEs) were coated with aptamer solution at various concentrations and the sensor response to increasing PSA concentration in buffer solution examined. AuNPs were deposited onto carbon electrodes in 10 cycles. AuNPs/SPCEs were then coated with a self-assembled monolayer (SAM) of 16-mercaptohexadecanoic acid prior to aptamer immobilization at dose of 5 μg mL-1. The results indicate that anisotropic AuNPs/SPCEs outperform bare gold electrodes in terms of decreased amount of aptamer bunches as well as the number of intermediate PSA-aptamer complexes formed on the electrode surface. The key finding is that the fabricated aptasensor is sensitive enough [limit of detection (LoD) 1.95 ng mL-1] for early diagnosis of prostate cancer and displays linear response in the physiologically relevant concentration range (0 ng mL-1 to 10 ng mL-1), as shown by the calibration curve of the relative change in electron transfer resistance (Δ R CT) versus PSA concentration when aptamer/SAM/AuNPs/SPCEs were exposed to buffer containing PSA at different concentrations.

  3. Long-term persistence and function of hematopoietic stem cell-derived chimeric antigen receptor T cells in a nonhuman primate model of HIV/AIDS.

    Directory of Open Access Journals (Sweden)

    Anjie Zhen

    2017-12-01

    Full Text Available Chimeric Antigen Receptor (CAR T-cells have emerged as a powerful immunotherapy for various forms of cancer and show promise in treating HIV-1 infection. However, significant limitations are persistence and whether peripheral T cell-based products can respond to malignant or infected cells that may reappear months or years after treatment remains unclear. Hematopoietic Stem/Progenitor Cells (HSPCs are capable of long-term engraftment and have the potential to overcome these limitations. Here, we report the use of a protective CD4 chimeric antigen receptor (C46CD4CAR to redirect HSPC-derived T-cells against simian/human immunodeficiency virus (SHIV infection in pigtail macaques. CAR-containing cells persisted for more than 2 years without any measurable toxicity and were capable of multilineage engraftment. Combination antiretroviral therapy (cART treatment followed by cART withdrawal resulted in lower viral rebound in CAR animals relative to controls, and demonstrated an immune memory-like response. We found CAR-expressing cells in multiple lymphoid tissues, decreased tissue-associated SHIV RNA levels, and substantially higher CD4/CD8 ratios in the gut as compared to controls. These results show that HSPC-derived CAR T-cells are capable of long-term engraftment and immune surveillance. This study demonstrates for the first time the safety and feasibility of HSPC-based CAR therapy in a large animal preclinical model.

  4. Phage display used for gene cloning of human recombinant antibody against the erythrocyte surface antigen, rhesus D

    DEFF Research Database (Denmark)

    Dziegiel, Morten Hanefeld; Nielsen, L K; Andersen, P S

    1995-01-01

    A novel phage display system has been developed for PCR amplification and cloning of the Fab fragments of human immunoglobulin genes. Using this system, we have cloned an antibody from a mouse-human hybridoma cell line directed against the erythrocyte antigen rhesus D. Intact erythrocytes were used...... Fab phages demonstrates that it is possible to by-pass purification of the antigen of interest. Comparison with published germline sequences demonstrated that the immunoglobulin coding regions had the highest homology to the VH 1.9III and V kappa Hum kappa v325 germline genes, respectively....

  5. Disposable immunoassay for hepatitis B surface antigen based on a graphene paste electrode functionalized with gold nanoparticles and a Nafion-cysteine conjugate

    International Nuclear Information System (INIS)

    Huang, K.-J.; Li, J.; Liu, Y.-M.; Yu, S.; Yu, M.; Cao, X.

    2012-01-01

    We report on the modification of a graphene paste electrode with gold nanoparticles (AuNPs) and a Nafion-L-cysteine composite film, and how this electrode can serve as a platform for the construction of a novel electrochemical immunosensor for the detection of hepatitis B surface antigen (HBsAg). To obtain the immunosensor, an antibody against HBsAg was immobilized on the surface of the electrode, and this process was followed by cyclic voltammetry and electrochemical impedance spectroscopy. The peak currents of a hexacyanoferrate redox system decreased on formation of the antibody-antigen complex on the surface of the electrode. Then increased electrochemical response is thought to result from a combination of beneficial effects including the biocompatibility and large surface area of the AuNPs, the high conductivity of the graphene paste electrode, the synergistic effects of composite film, and the increased quantity of HBsAb adsorbed on the electrode surface. The differential pulse voltammetric responses of the hexacyanoferrate redox pair are proportional to the concentration of HBsAg in the range from 0. 5-800 ng mL -1 , and the detection limit is 0.1 ng mL -1 (at an S/N of 3). The immunosensor is sensitive and stable. (author)

  6. Longitudinal evaluation of humoral immune response and merozoite surface antigen diversity in calves naturally infected with Babesia bovis, in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos António Matos

    Full Text Available Abstract Babesiosis is an economically important infectious disease affecting cattle worldwide. In order to longitudinally evaluate the humoral immune response against Babesia bovis and the merozoite surface antigen diversity of B. bovis among naturally infected calves in Taiaçu, Brazil, serum and DNA samples from 15 calves were obtained quarterly, from their birth to 12 months of age. Anti-B. bovis IgG antibodies were detected by means of the indirect fluorescent antibody test (IFAT and enzyme-linked immunosorbent assay (ELISA. The polymerase chain reaction (PCR was used to investigate the genetic diversity of B. bovis, based on the genes that encode merozoite surface antigens (MSA-1, MSA-2b and MSA-2c. The serological results demonstrated that up to six months of age, all the calves developed active immunity against B. bovis. Among the 75 DNA samples evaluated, 2, 4 and 5 sequences of the genes msa-1, msa-2b and msa-2c were obtained. The present study demonstrated that the msa-1 and msa-2b genes sequences amplified from blood DNA of calves positive to B. bovis from Taiaçu were genetically distinct, and that msa-2c was conserved. All animals were serologically positive to ELISA and IFAT, which used full repertoire of parasite antigens in despite of the genetic diversity of MSAs.

  7. A Longitudinal Hepatitis B Vaccine Cohort Demonstrates Long-lasting Hepatitis B Virus (HBV) Cellular Immunity Despite Loss of Antibody Against HBV Surface Antigen.

    Science.gov (United States)

    Simons, Brenna C; Spradling, Philip R; Bruden, Dana J T; Zanis, Carolyn; Case, Samantha; Choromanski, Tammy L; Apodaca, Minjun; Brogdon, Hazel D; Dwyer, Gaelen; Snowball, Mary; Negus, Susan; Bruce, Michael G; Morishima, Chihiro; Knall, Cindy; McMahon, Brian J

    2016-07-15

    Long-lasting protection resulting from hepatitis B vaccine, despite loss of antibody against hepatitis B virus (HBV) surface antigen (anti-HBs), is undetermined. We recruited persons from a cohort vaccinated with plasma-derived hepatitis B vaccine in 1981 who have been followed periodically since. We performed serological testing for anti-HBs and microRNA-155 and assessed HBV-specific T-cell responses by enzyme-linked immunospot and cytometric bead array. Study subgroups were defined 32 years after vaccination as having an anti-HBs level of either ≥10 mIU/mL (group 1; n = 13) or anti-HBs level, tested positive for tumor necrosis factor α, interleukin 10, or interleukin 6 production by HBV surface antigen-specific T cells. The frequency of natural killer T cells correlated with the level of anti-HBs (P = .008). The proportion of participants who demonstrated T-cell responses to HBV core antigen varied among the cytokines measured, suggesting some natural exposure to HBV in the study group. No participant had evidence of breakthrough HBV infection. Evidence of long-lasting cellular immunity, regardless of anti-HBs level, suggests that protection afforded by primary immunization with plasma-derived hepatitis B vaccine during childhood and adulthood lasts at least 32 years. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  8. A Study of Molecular Mimicry and Immunological Cross-reactivity between Hepatitis B Surface Antigen and Myelin Mimics

    Directory of Open Access Journals (Sweden)

    Diego Vergani

    2005-01-01

    Full Text Available On the basis of the reported association between hepatitis B vaccination (HBvacc and autoimmune demyelinating complications such as multiple sclerosis (MS, we have looked for aminoacid similarities between the small hepatitis B virus surface antigen (SHBsAg, and the MS-autoantigens myelin basic protein (MBP and myelin oligodendrocyte glycoprotein (MOG that could serve as targets of immunological cross-reactivity. Twenty-mer peptides spanning 4 SHBsAg/MOG and 1 SHBsAg/MBP mimicking pairs, were constructed and tested by ELISA as targets of cross-reactive responses. A total of 147 samples from 58 adults were collected before HBvacc (58/58, and post-HBvacc (48/58 before the second and 41/58 before the third boost. Eighty-seven sera from anti-SHBsAg antibody negative patients with various diseases were tested as pathological controls. Reactivity to at least one of the SHBsAg peptides was found in 8 (14% pre-HBvacc subjects; amongst the remaining 50, reactivity to at least one of the SHBsAg peptides appeared in 47 (94% post-HBvacc. Reactivity to at least one of the MOG mimics was present in 4 (8% pre-HBvacc and in 30 (60% post-HBvacc (p < 0.001. Overall 30/50 (60% vaccinees had SHBsAg/MOG double reactivity on at least one occasion compared to none before-vaccination and in 2 (2% of the pathological controls (p < 0.001 for both. SHBsAg/MOG double reactivity was cross-reactive as confirmed by inhibition studies. At 6 months post-vaccination, 3 of the 4 anti-MOG reactive cases before vaccination and 7 of the 24 (29% of the anti-MOG reactive cases at 3 months post-vaccination had lost their reactivity to MOG5-24. There was no reactivity to the SHBsAg/MBP mimics. None of the vaccinees reported symptoms of demyelinating disorders. In view of the observed SHBsAg/MOG cross-reactivity, the vaccine's possible role as an immunomodulator of viral/self cross-reactivity must be further investigated.

  9. Long-term changes in sea surface temperatures

    International Nuclear Information System (INIS)

    Parker, D.E.

    1994-01-01

    Historical observations of sea surface temperature since 1856 have been improved by applying corrections to compensate for the predominant use of uninsulated or partly insulated buckets until the Second World War. There are large gaps in coverage in the late nineteenth century and around the two world wars, but a range of statistical techniques suggest that these gaps do not severely prejudice estimates of global and regional climatic change. Nonetheless, to improve the analysis on smaller scales, many unused historical data are to be digitized and incorporated. For recent years, satellite-based sea surface temperatures have improved the coverage, after adjustments for their biases relative to in situ data. An initial version of a nominally globally complete sea ice and interpolated sea surface temperature data set, beginning in 1871, has been created for use in numerical simulations of recent climate. Long time series of corrected regional, hemispheric, and global sea surface temperatures are mostly consistent with corresponding night marine air temperature series, and confirm the regionally specific climatic changes portrayed in the Scientific Assessments of the intergovernmental Panel on Climate Change. The observations also show an El Nino-like oscillation on bidecadal and longer time scales

  10. Effect of potential attraction term on surface tension of ionic liquids

    Science.gov (United States)

    Vaziri, N.; Khordad, R.; Rezaei, G.

    2018-03-01

    In this work, we have studied the effect of attraction term of molecular potential on surface tension of ionic liquids (ILs). For this purpose, we have introduced two different potential models to obtain analytical expressions for the surface tension of ILs. The introduced potential models have different attraction terms. The obtained surface tensions in this work have been compared with other theoretical methods and also experimental data. Using the calculated surface tension, the sound velocity is also estimated. We have studied the structural effects on the surface tensions of imidazolium-based ionic liquids. It is found that the cation alkyl chain length and the anion size play important roles to the surface tension of the selected ionic liquids. The calculated surface tensions show a good harmony with experimental data. It is clear that the attraction term of molecular potential has an important role on surface tension and sound velocity of our system.

  11. Transplacentally acquired maternal antibody against hepatitis B surface antigen in infants and its influence on the response to hepatitis B vaccine.

    Directory of Open Access Journals (Sweden)

    Zhiqun Wang

    Full Text Available BACKGROUND: Passively acquired maternal antibodies in infants may inhibit active immune responses to vaccines. Whether maternal antibody against hepatitis B surface antigen (anti-HBs in infants may influence the long-term immunogenicity of hepatitis B vaccine remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Totally 338 pairs of mothers and children were enrolled. All infants were routinely vaccinated against hepatitis B based on 0-, 1- and 6-month schedule. We characterized the transplacental transfer of maternal anti-HBs, and compared anti-HBs response in children of mothers with or without anti-HBs. In a prospective observation, all 63 anti-HBs positive mothers transferred anti-HBs to their infants; 84.1% of the infants had higher anti-HBs concentrations than their mothers. One and half years after vaccination with three doses of hepatitis B vaccine, the positive rate and geometric mean concentration (GMC of anti-HBs in 32 infants with maternal anti-HBs were comparable with those in 32 infants without maternal antibody (90.6% vs 87.5%, P = 0.688, and 74.5 vs 73.5 mIU/ml, P = 0.742, respectively. In a retrospective analysis, five and half years after vaccination with three doses vaccine, the positive rates of anti-HBs in 88 children of mothers with anti-HBs ≥1000 mIU/ml, 94 children of mothers with anti-HBs 10-999 mIU/ml, and 61 children of mothers with anti-HBs <10 mIU/ml were 72.7%, 69.2%, and 63.9% (P = 0.521, respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (P = 0.726, respectively. CONCLUSIONS/SIGNIFICANCE: The data demonstrate that maternal anti-HBs in infants, even at high concentrations, does not inhibit the long-term immunogenicity of hepatitis B vaccine. Thus, current hepatitis B vaccination schedule for infants will be still effective in the future when most infants are positive for maternal anti-HBs due to the massive vaccination against hepatitis B.

  12. Crystallization and preliminary X-ray diffraction analysis of PsaA, the adhesive pilin subunit that forms the pH 6 antigen on the surface of Yersinia pestis

    International Nuclear Information System (INIS)

    Bao, Rui; Esser, Lothar; Sadhukhan, Annapurna; Nair, Manoj K. M.; Schifferli, Dieter M.; Xia, Di

    2012-01-01

    The pH 6 antigen Psa displayed on the surface of Yersinia pestis, the bacterium that causes plague in humans, consists of polymers of a single protein subunit termed PsaA. Donor-strand complemented PsaA was purified and crystallized. Yersinia pestis has been responsible for a number of high-mortality epidemics throughout human history. Like all other bacterial infections, the pathogenesis of Y. pestis begins with the attachment of bacteria to the surface of host cells. At least five surface proteins from Y. pestis have been shown to interact with host cells. Psa, the pH 6 antigen, is one of them and is deployed on the surface of bacteria as thin flexible fibrils that are the result of the polymerization of a single PsaA pilin subunit. Here, the crystallization of recombinant donor-strand complemented PsaA by the hanging-drop vapor-diffusion method is reported. X-ray diffraction data sets were collected to 1.9 Å resolution from a native crystal and to 1.5 Å resolution from a bromide-derivatized crystal. These crystals displayed the symmetry of the orthorhombic space group P222 1 , with unit-cell parameters a = 26.3, b = 54.6, c = 102.1 Å. Initial phases were derived from single isomorphous replacement with anomalous scattering experiments, resulting in an electron-density map that showed a single molecule in the crystallographic asymmetric unit. Sequence assignment was aided by residues binding to bromide ions of the heavy-atom derivative

  13. Seroprevalence of hepatitis B e antigen (HBe antigen and B core antibodies (IgG anti-HBcore and IgM anti-HBcore among hepatitis B surface antigen positive blood donors at a Tertiary Centre in Nigeria

    Directory of Open Access Journals (Sweden)

    Akinbami Akinsegun A

    2012-03-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is a common cause of liver disease throughout the world. HBV is transmitted through blood and other body fluids, including semen and saliva. Chronic replication of HBV virons is characterized by persistence circulation of HBsAg, HBeAg and HBV DNA; usually with anti-HBc and occasionally with anti-HBs. Aim: To determine the prevalence of HBeAg, IgG anti-HBcore and IgM anti-HBcore amongst HBsAg positive blood donors. These parameters are reflective of transmissibility and active hepatitis B infection. A cross sectional study was carried out at the blood donor clinics of Lagos State University Teaching Hospital Ikeja and Lagos University Teaching Hospital Idiaraba. A total of 267 donors were recruited to determine HBe antigen, IgG and IgM anti-HBcore antibodies amongst hepatitis BsAg positive donors. Five milliliters of blood was collected from those who tested positive to HBsAg screen during donation. The sera were subjected to enzyme linked immunosorbent assay (ELISA. Pearson chi-squared test was used for the analytical assessment. Findings A total number of 267 HBsAg positive blood donors were studied. A seroprevalence of 8.2% (22 of 267 HBeAg was obtained, 4 of 267 (1.5% were indeterminate while 241 (90.3% tested negative. Only 27 out of 267 donors (10.1% tested positive to IgM anti-HBcore, 234(87.6% tested negative, while 6(2.2% were indeterminate. A higher percentage of 60.7% (162 of 267 tested positive to IgG anti-HBcore, while 39.3% (105 of 267 tested negative. Conclusion There is a low seroprevalence rate of HBeAg-positive chronic hepatitis and relatively high IgG anti-HBcore and IgM anti-HBcore rates in South West Nigeria.

  14. ELISA detection of IgG antibody against a recombinant major surface antigen (Nc-p43) fragment of Neospora caninum in bovine sera

    Science.gov (United States)

    Ahn, Hye-Jin; Kim, Sera; Kim, Dae-Yong

    2003-01-01

    An ELISA was established to measure bovine IgG directed against the recombinant antigenic determinant of Nc-p43, a major surface antigen of Neospora caninum. In a previous study, two thirds of the C-terminal of the molecule was expressed as a 6 × His tagged protein (Ncp43P) for ELISA using 2/3 of the N-terminal of SAG1 from Toxoplasma gondii as a control (TgSAG1A). Among 852 cattle sera collected from stock farms scattered nation-wide, 103 sera (12.1%) were found to react with Ncp43P positively, but no positive reaction was observed with TgSAG1A. This study shows that Ncp43P could be available as an efficient antigen for the diagnosis of neosporosis in cattle. Furthermore, it together with TgSAG1A, could be useful for the differential diagnosis of N. caninum and T. gondii infections in other mammals. PMID:12972732

  15. Phage display used for gene cloning of human recombinant antibody against the erythrocyte surface antigen, rhesus D

    DEFF Research Database (Denmark)

    Dziegiel, Morten Hanefeld; Nielsen, L K; Andersen, P S

    1995-01-01

    A novel phage display system has been developed for PCR amplification and cloning of the Fab fragments of human immunoglobulin genes. Using this system, we have cloned an antibody from a mouse-human hybridoma cell line directed against the erythrocyte antigen rhesus D. Intact erythrocytes were used...... for absorption of the Fab phages. Soluble Fab fragments produced from the cloned material showed identical performance to the parental antibody in agglutination assays. Gel filtration confirmed that the Fab fragment consists of a kappa-Fd heterodimer. The successful use of intact cells for selection of specific...... Fab phages demonstrates that it is possible to by-pass purification of the antigen of interest. Comparison with published germline sequences demonstrated that the immunoglobulin coding regions had the highest homology to the VH 1.9III and V kappa Hum kappa v325 germline genes, respectively....

  16. Selection of scFv Antibody Fragments Binding to Human Blood versus Lymphatic Endothelial Surface Antigens by Direct Cell Phage Display.

    Science.gov (United States)

    Keller, Thomas; Kalt, Romana; Raab, Ingrid; Schachner, Helga; Mayrhofer, Corina; Kerjaschki, Dontscho; Hantusch, Brigitte

    2015-01-01

    The identification of marker molecules specific for blood and lymphatic endothelium may provide new diagnostic tools and identify new targets for therapy of immune, microvascular and cancerous diseases. Here, we used a phage display library expressing human randomized single-chain Fv (scFv) antibodies for direct panning against live cultures of blood (BECs) and lymphatic (LECs) endothelial cells in solution. After six panning rounds, out of 944 sequenced antibody clones, we retrieved 166 unique/diverse scFv fragments, as indicated by the V-region sequences. Specificities of these phage clone antibodies for respective compartments were individually tested by direct cell ELISA, indicating that mainly pan-endothelial cell (EC) binders had been selected, but also revealing a subset of BEC-specific scFv antibodies. The specific staining pattern was recapitulated by twelve phage-independently expressed scFv antibodies. Binding capacity to BECs and LECs and differential staining of BEC versus LEC by a subset of eight scFv antibodies was confirmed by immunofluorescence staining. As one antigen, CD146 was identified by immunoprecipitation with phage-independent scFv fragment. This antibody, B6-11, specifically bound to recombinant CD146, and to native CD146 expressed by BECs, melanoma cells and blood vessels. Further, binding capacity of B6-11 to CD146 was fully retained after fusion to a mouse Fc portion, which enabled eukaryotic cell expression. Beyond visualization and diagnosis, this antibody might be used as a functional tool. Overall, our approach provided a method to select antibodies specific for endothelial surface determinants in their native configuration. We successfully selected antibodies that bind to antigens expressed on the human endothelial cell surfaces in situ, showing that BECs and LECs share a majority of surface antigens, which is complemented by cell-type specific, unique markers.

  17. Energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from Tannerella forsythensis using microwave or autoclave heating with citraconic anhydride.

    Science.gov (United States)

    Moriguchi, K; Mitamura, Y; Iwami, J; Hasegawa, Y; Higuchi, N; Murakami, Y; Maeda, H; Yoshimura, F; Nakamura, H; Ohno, N

    2012-11-01

    Tannerella forsythensis (Bacteroides forsythus), an anaerobic Gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. It is characterized by two unique protein bands with molecular weights of more than 200 kDa. It also is known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. We examined the relationship between high molecular weight proteins and the S-layer using electron microscopic immunolabeling with chemical fixation and an antigen retrieval procedure consisting of heating in a microwave oven or autoclave with citraconic anhydride. Immunogold particles were localized clearly at the outermost cell surface. We also used energy-filtering transmission electron microscopy (EFTEM) to visualize 3, 3'-diaminobenzidine tetrahydrochloride (DAB) reaction products after microwave antigen retrieval with 1% citraconic anhydride. The three-window method for electron spectroscopic images (ESI) of nitrogen by the EFTEM reflected the presence of moieties demonstrated by the DAB reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles. The mapping patterns of net nitrogen were restricted to the outermost cell surface.

  18. Long-term in vitro reactivity for human leukocyte antigen antibodies and comparison of detection using serum versus plasma.

    Science.gov (United States)

    Norris, Philip J; Lee, Jar-How; Carrick, Danielle M; Gottschall, Jerome L; Lebedeva, Mila; de Castro, B R; Kleinman, Steven H; Busch, Michael P

    2009-02-01

    Human leukocyte antigen (HLA) antibodies are a possible cause of transfusion-related acute lung injury (TRALI), and fluorescent bead assays are often used for antibody detection. Serum is the manufacturer's recommended sample, but plasma may be easier to obtain for studies of HLA antibody prevalence and TRALI case investigations. Specimens were obtained from 44 multiparous females positive for the presence of HLA antibodies by lymphocytotoxicity testing at least 13 years prior and from 1000 contemporary blood donors. Screening tests were performed using a multiplex bead-based assay. In addition to comparing results obtained with paired plasma and serum samples, the effects of storage at 4 degrees C for 1 week and of multiple freeze-thaw cycles were evaluated. Of 42 evaluable subjects with HLA antibodies documented more than 13 years earlier, only 1 showed loss of detectable antibodies, with 39 (93%) positive in the screening assay for HLA Class I and 24 (57%) positive in the screening assay for HLA Class II antibodies. In 968 evaluable contemporary donors, 291 screened positive for the presence of HLA Class I and 206 for HLA Class II antibodies using a low assay cutoff. Screening test concordance using paired plasma and serum samples was high, particularly for subjects with higher-level antibodies. Refrigeration of samples for 1 week did not significantly affect assay results, while repeated freeze-thaw cycles caused a decrement in signal level. Serum and plasma samples gave concordant results in the majority of cases, particularly for specimens with higher-level antibodies. High-level HLA antibodies were present in most individuals for more than 13 years.

  19. Breaking tolerance in hepatitis B surface antigen (HBsAg) transgenic mice by vaccination with cross-reactive, natural HBsAg variants

    DEFF Research Database (Denmark)

    Schirmbeck, Reinhold; Dikopoulos, Nektarios; Kwissa, Marcin

    2003-01-01

    Processing exogenous hepatitis B surface antigen (HBsAg) of the hepatitis B virus (HBV) generates the K(b)-binding S(208-215) epitope 1; processing endogenous HBsAg generates the K(b)-binding S(190-197) epitope 2. Cross-reactive CD8(+) T cell responses were primed to epitope 1 but not epitope 2...... HBs-tg mice showed reduced antigenemia. Hence, vaccination with natural HBsAg variants from different HBV sero/genotypes can prime cross-reactive, specific CD8(+) T cell immunity that breaks tolerance to HBsAg....

  20. Hepatitis B virus surface antigen and anti-hepatitis C virus rapid tests underestimate hepatitis prevalence among HIV-infected patients

    DEFF Research Database (Denmark)

    Hønge, Bo Langhoff; Jespersen, S; Medina, C

    2014-01-01

    OBJECTIVES: In the case of coinfection with HIV and hepatitis B virus (HBV) and/or hepatitis C virus (HCV), hepatic disease progression is often accelerated, with higher rates of liver cirrhosis and liver-related mortality. We aimed to evaluate the performance of the rapid tests used routinely...... to detect HBV surface antigen (HBsAg) and anti-HCV among HIV-infected patients in Guinea-Bissau. METHODS: Blood samples from HIV-infected patients in Guinea-Bissau were stored after testing for HBsAg and anti-HCV with rapid tests. Samples were subsequently re-tested for HBsAg and anti-HCV in Denmark...

  1. Insecticide-treated bed nets reduce plasma antibody levels and limit the repertoire of antibodies to Plasmodium falciparum variant surface antigens

    DEFF Research Database (Denmark)

    Askjaer, N; Maxwell, C; Chambo, W

    2001-01-01

    The use of insecticide-treated bed nets (ITN) has been documented to reduce malaria morbidity and mortality in areas with endemic malaria, but concerns have been raised that ITN usage could affect the acquisition of malaria immunity. Several lines of evidence have indicated that antibodies against...... variant surface antigens (VSA) are important in the development of naturally acquired immunity to Plasmodium falciparum malaria and may thus be good indicators of immune status. We have compared the levels of VSA antibodies in plasma from children who have used ITN for 4 years to levels in plasma from...

  2. Hepatitis B surface antigen quantity positively correlates with plasma levels of microRNAs differentially expressed in immunological phases of chronic hepatitis B in children

    DEFF Research Database (Denmark)

    Winther, Thilde Nordmann; Heiberg, Ida Louise; Bang-Berthelsen, Claus Heiner

    2013-01-01

    Children with chronic hepatitis B (CHB) are at high risk of progressive liver disease. It is suggested that a newly-identified panel of 16 microRNAs is important in the pathogenesis of CHB in children. Subviral hepatitis B surface antigen (HBsAg) particles are produced in large excess over...... infectious virions. Interestingly, circulating HBsAg particles have been shown to carry microRNAs. A thorough characterisation of the identified microRNAs and HBsAg over time in plasma from children with CHB may provide useful information about the natural course of childhood CHB....

  3. Comparison of hepatitis B virus core-related antigen and hepatitis B surface antigen for predicting HBeAg seroconversion in chronic hepatitis B patients with pegylated interferon therapy.

    Science.gov (United States)

    Wang, Meng-Lan; Liao, Juan; Wei, Bing; Zhang, Dong-Mei; He, Ming; Tao, Ming-Chuan; Chen, En-Qiang; Tang, Hong

    2018-02-20

    Recent studies revealed that both quantitative hepatitis B surface antigen (qHBsAg) and hepatitis B core-related antigen (qHBcrAg) could serve as a good marker for predicting treatment response and indirectly reflecting intrahepatic cccDNA levels. This study aimed to compare the value of qHBsAg and qHBcrAg in predicting HBeAg seroconversion among patients undergoing PEG-IFN therapy. A total of 31 HBeAg-positive patients, who underwent PEG-IFN therapy for 12 months and follow-up for six months were retrospectively included in this study. The serum qHBsAg level was measured using Elecsys® HBsAg II Quant Assay and serum qHBcrAg level was measured using chemiluminescence enzyme immunoassay. During the 12-month treatment, the absolute levels of serum qHBsAg and qHBcrAg were both lower in patients with HBeAg seroconversion as compared to patients without HBeAg seroconversion, but only the difference in qHBcrAg was significant. During the 6-month follow-up period, both qHBsAg and qHBcrAg levels were rebounded significantly among patients without HBeAg seroconversion. Among patients with HBeAg seroconversion, no sustained significant decline of qHBsAg was observed, but serum qHBcrAg levels continued to decline significantly. The ROC curves analysis showed that both absolute qHBcrAg level and the extent of qHBcrAg decline at month 1 had better performance for the prediction of HBeAg seroconversion at month 6 after treatment, as compared to that of qHBsAg. Early on-treatment qHBcrAg may be a good biomarker for predicting off-treatment HBeAg seroconversion in patients receiving PEG-IFN therapy.

  4. A Sheep in Wolf's Clothing: Listeria innocua Strains with Teichoic Acid-Associated Surface Antigens and Genes Characteristic of Listeria monocytogenes Serogroup 4

    Science.gov (United States)

    Lan, Zheng; Fiedler, Franz; Kathariou, Sophia

    2000-01-01

    Listeria monocytogenes serotype 4b has been implicated in numerous food-borne epidemics and in a substantial fraction of sporadic listeriosis. A unique lineage of the nonpathogenic species Listeria innocua was found to express teichoic acid-associated surface antigens that were otherwise expressed only by L. monocytogenes of serotype 4b and the rare serotypes 4d and 4e. These L. innocua strains were also found to harbor sequences homologous to the gene gtcA, which has been shown to be essential for teichoic acid glycosylation in L. monocytogenes serotype 4b. Transposon mutagenesis and genetic studies revealed that the gtcA gene identified in this lineage of L. innocua was functional in serotype 4b-like glycosylation of the teichoic acids of these organisms. The genomic organization of the gtcA region was conserved between this lineage of L. innocua and L. monocytogenes serotype 4b. Our data are in agreement with the hypothesis that, in this lineage of L. innocua, gtcA was acquired by lateral transfer from L. monocytogenes serogroup 4. The high degree of nucleotide sequence conservation in the gtcA sequences suggests that such transfer was relatively recent. Transfer events of this type may alter the surface antigenic properties of L. innocua and may eventually lead to evolution of novel pathogenic lineages through additional acquisition of genes from virulent listeriae. PMID:11029438

  5. Isolation of recombinant Hepatitis B surface antigen with antibody-conjugated superparamagnetic Fe3O4/SiO2core-shell nanoparticles.

    Science.gov (United States)

    Mostafaei, Mehdi; Hosseini, Seyed Nezamedin; Khatami, Maryam; Javidanbardan, Amin; Sepahy, Abbas Akhavan; Asadi, Ebadullah

    2018-05-01

    In the production process of recombinant Hepatitis B surface antigen (rHBsAg) various separation techniques are used to purify this virus-like particle (VLP). In this study, we developed antibody-conjugated super-paramagnetic Fe 3 O 4 /SiO 2 core-shell nanoparticles as a highly selective method for isolation of expressed rHBsAg in yeast Pichia pastoris. For this purpose, first, iron oxide magnetic nanoparticles (MNP s ) were prepared by co-precipitation method in alkali media and coated with silica. Then the surface was activated by amine groups and conjugated with oxidized antibodies. X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) were used to study the physical properties of MNPs. To evaluate the efficacy of these MNPs as a purification technique successfully synthesized MNPs were added to the rHBsAg sample to couple with the antigen and then be isolated based on their magnetic property. In the present research, in the optimum condition, we could isolate 65% of total rHBsAg from the final vaccine sample with purity above 95%. In this procedure, the maximum obtained specific yield (mg HBsAg/mg MNPs) was equal to 37.6. These results underline the potential application of the immune-magnetic separation (IMS) in the future bioseparation systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Effects of pregnancy and intensity of Plasmodium falciparum transmission on immunoglobulin G subclass responses to variant surface antigens

    DEFF Research Database (Denmark)

    Megnekou, Rosette; Staalsoe, Trine; Taylor, Diane W

    2005-01-01

    Placenta-sequestering Plasmodium falciparum involved in the pathogenesis of pregnancy-associated malaria (PAM) in otherwise clinically immune women expresses particular variant surface antigens (VSA(PAM)) on the surface of infected erythrocytes that differ from VSA found in parasitized nonpregnant...... individuals (non-PAM type VSA). We studied levels of immunoglobulin G (IgG) and IgG subclasses with specificity for VSA(PAM) and for non-PAM type VSA in pregnant and nonpregnant women from two sites with different endemicities in Cameroon. We found that VSA(PAM)-specific responses depended on the pregnancy...... status, parity, gestational age, and parasite transmission intensity, whereas only the parasite transmission intensity influenced the levels of IgG specific for non-PAM type VSA. For both types of VSA, the responses were dominated by the cytophilic subclass IgG1, followed by IgG3. In pregnant women...

  7. Immunoblot analysis of the seroreactivity to recombinant Borrelia burgdorferi sensu lato antigens, including VlsE, in the long-term course of treated patients with erythema migrans.

    Science.gov (United States)

    Glatz, Martin; Fingerle, Volker; Wilske, Bettina; Ambros-Rudolph, Christina; Kerl, Helmut; Müllegger, Robert R

    2008-01-01

    We evaluated whether immunoblotting is capable of substantiating the posttreatment clinical assessment of patients with erythema migrans (EM), the hallmark of early Lyme borreliosis. In 50 patients, seroreactivity to different antigens of Borrelia burgdorferi sensu lato was analyzed by a recombinant immunoblot test (IB) in consecutive serum samples from a minimum follow-up period of 1 year. Antigens in the IgG test were decorin-binding protein A, internal fragment of p41 (p41i), outer surface protein C (OspC), p39, variable major protein-like sequence expressed (VlsE), p58 and p100; those in the IgM test were p41i, OspC and p39. Immune responses were correlated with clinical and treatment-related parameters. Positive IB results were found in 50% before, in 57% directly after therapy and in 44% by the end of the follow-up for the IgG class, and in 36, 43 and 12% for the IgM class. In acute and convalescence phase sera, VlsE was most immunogenic on IgG testing (60 and 70%), and p41i (46 and 57%) and OspC (40 and 57%) for the IgM class. By the end of the follow-up, only the anti-p41i IgM response was significantly decreased to 24%. No correlation was found between IB results and treatment-related parameters. Thus, immunoblotting does not add to the clinical assessment of EM patients after treatment. (c) 2008 S. Karger AG, Basel.

  8. Clinical Characteristics and Correlation Analysis of Subjects with Chronic Hepatitis B Virus (HBV) Infection and Sustained Low Levels of Hepatitis B Surface Antigen (HBsAg)

    Science.gov (United States)

    Cheng, Jun; Dai, Yuzhu; Yan, Li; Zhou, Huajun; Xu, Xujian

    2018-01-01

    Background The aim of this study was to investigate the clinical characteristics of individuals with chronic hepatitis B virus (HBV) infection with persistent low levels of hepatitis B surface antigen (HBsAg) and to undertake a correlation analysis of the clinical characteristics. Material/Methods The study included 1,204 subjects with chronic HBV infection. Serum HBsAg, HBV envelope antigen (HBeAg), and HBV core antigen (HBcAg) levels were measured using the chemiluminescent microparticle immunoassay (CMIA) and the neutralization test. HBV DNA was measured using real-time fluorescence quantitative polymerase chain reaction (RT-FQ-PCR). Results There were 1,023 subjects in the high-level HBsAg group (HBsAg level ≥10 IU/mL) and 181 subjects in the low-level HBsAg group (HBsAg level HBV-M2), and the asymptomatic carrier (ASC) status was 98.34%. The low-level HBsAg group had a lower HBV DNA-positive rate compared with the high-level HBsAg group (40.33% vs. 75.07%), with a normal distribution across all age groups (P>0.05). The low-level HBsAg group included an older age group. A low-level of HBsAg was positively correlated with a low level of replication of HBV DNA (r=0.452). Conclusions The findings of this study showed that individuals with chronic HBV infection and sustained low-levels of HBsAg were an older population and had a lower level of replicating HBV DNA when compared with individuals with high levels of HBsAg, and the majority (93.7%) were also HBsAg and HBeAg and HBcAg-positive. PMID:29593208

  9. The binding parameters of radiolabelled monoclonal F (ab')2 and Fab' fragments relative to immunoglobulin G in reactions with surface-bound antigens

    International Nuclear Information System (INIS)

    Fjeld, J.G.; Nustad, K.; Michaelsen, T.E.

    1992-01-01

    The binding parameters of iodine-125-labelled intact monoclonal immunoglobulin G (IgG), F(ab') 2 and Fab' fragments were compared. The study was carried out with the two monoclonal antibodies (MoAbs) K13 and K16 specific for human Ig light chains κ and λ, respectively. When testing the 125 I-MoAbs against monodisperse polymer particles coated with the specific antigens, the K a for the F(ab') 2 fragments were similar to that for IgG, while the K a for the Fab' fragments were reduced to 10%-20% of that for IgG. The number N of effective target sites revealed with Fab' was higher than with F(ab') and IgG, presumably because less surface area is occupied by the small Fab' molecules. The immunoreactive fraction F ranged according to IgG>F(ab') 2 >Fab'. The explanation of the moderate difference between the K a of the monoclonal Fab' and the divalent IgG and F(ab') 2 was that the divalent molecules were not divalently attached to the particles. When testing the same antibody preparations against humanlymphoma cells producing Ig with light chains κ or λ, the binding results were less reliable than when particles were utilised, presumably due to antigen shedding. Different MoAbs vary in their loss of immunoreactivity due to enzymatic degradation and the radiolabelling procedure. The preparation of the radiolabelled fragments should therefore be optimized for each MoAb, and evaluation is necessary before injection. Artificial targets with a low leakage of antigen, like the monodisperse polymer particles here applied, are recommended for the in vitro evaluation of the immunoreactivity of labelled MoAb preparations. (orig.)

  10. Coexistence of hepatitis B surface antigen and antibody to hepatitis B surface may increase the risk of hepatocellular carcinoma in chronic hepatitis B virus infection: a retrospective cohort study.

    Science.gov (United States)

    Seo, Seung In; Choi, Hyeok Soo; Choi, Bo Youn; Kim, Hyoung Su; Kim, Hak Yang; Jang, Myoung Kuk

    2014-01-01

    The simultaneous detection of hepatitis B surface antigen (HBsAg) and antibody to hepatitis B surface (anti-HBs) is unusual in chronic hepatitis B virus (HBV) infection, but may be related with more advanced liver diseases. This retrospective long-term cohort study was aimed to investigate whether coexistence of HBsAg and anti-HBs may increase the risk of hepatocellular carcinoma (HCC) in chronic HBV infection. A total of 1,042 non-HCC patients were recruited and followed up for a median 4.3 years (range 1.0-22 years). Univariate and multivariate analyses were performed to identify the risk factors for HCC development. The prevalence of coexistence of HBsAg and anti-HBs was 7.0% (73/1,042). In univariate analysis, the 5-, 10-, and 15-year cumulative incidences of HCC were significantly higher in coexistence group than in HBsAg only group (12.7%, 23.4%, 69.4% vs. 4.9%, 13%, 20.6%, respectively; P = 0.008). In multivariate analysis, coexistence of HBsAg and anti-HBs [Hazard ratio (HR), 2.001; 95% confidence interval (CI), 1.023-3.912; P = 0.043] as well as male gender [HR, 1.898; 95% CI, 0.31-0.896; P = 0.018], age over 40 years [HR, 14.56; 95% CI, 4.499-47.08; P = 0.0001], and cirrhosis [HR, 7.995; 95% CI, 4.756-13.439; P = 0.0001] was identified as the independent factor for HCC development. Also, the cumulative incidence of HCC increased in proportion to the number of the risk factors. In conclusion, coexistence of HBsAg and anti-HBs may increase independently the risk of HCC development in chronic HBV infection. Therefore, consideration of HCC development is required in patients with coexistence of HBsAg and anti-HBs. © 2013 Wiley Periodicals, Inc.

  11. Prostate-specific antigen nadir after high-dose-rate brachytherapy predicts long-term survival outcomes in high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Hideyasu Tsumura

    2016-04-01

    Full Text Available Purpose : To evaluate the prognostic value of prostate-specific antigen nadir (nPSA after high-dose-rate (HDR brachytherapy in clinically non-metastatic high-risk prostate cancer patients. Material and methods : Data from 216 patients with high-risk or locally advanced prostate cancer who underwent HDR brachytherapy and external beam radiation therapy with long-term androgen deprivation therapy (ADT between 2003 and 2008 were analyzed. The median prostate-specific antigen (PSA level at diagnosis was 24 ng/ml (range: 3-338 ng/ml. The clinical stage was T1c-2a in 55 cases (26%, T2b-2c in 48 (22%, T3a in 75 (35%, and T3b-4 in 38 (17%. The mean dose to 90% of the planning target volume was 6.3 Gy/fraction of HDR brachytherapy. After 5 fractions, external beam radiation therapy with 10 fractions of 3 Gy was administered. All patients initially underwent neoadjuvant ADT for at least 6 months, and adjuvant ADT was continued for 36 months. The median follow-up was 7 years from the start of radiotherapy. Results : The 7-year PSA relapse-free rate among patients with a post-radiotherapy nPSA level of ≤ 0.02 ng/ml was 94%, compared with 23% for patients with higher nPSA values (HR = 28.57; 95% CI: 12.04-66.66; p < 0.001. Multivariate analysis revealed that the nPSA value after radiotherapy was a significant independent predictor of biochemical failure, whereas pretreatment predictive values for worse biochemical control including higher level of initial PSA, Gleason score ≥ 8, positive biopsy core rate ≥ 67%, and T3b-T4, failed to reach independent predictor status. The 7-year cancer-specific survival rate among patients with a post-radiotherapy nPSA level of ≤ 0.02 ng/ml was 99%, compared with 82% for patients with higher nPSA values (HR = 32.25; 95% CI: 3.401-333.3; p = 0.002. Conclusions : A post-radiotherapy nPSA value of ≤ 0.02 ng/ml was associated with better long-term biochemical tumor control even if patients had pretreatment predictive

  12. Long-term expression of Fos-related antigen and transient expression of delta FosB associated with seizures in the rat hippocampus and striatum.

    Science.gov (United States)

    Bing, G; Wang, W; Qi, Q; Feng, Z; Hudson, P; Jin, L; Zhang, W; Bing, R; Hong, J S

    1997-01-01

    Systemic administration of kainic acid (KA), an analogue of glutamic acid, causes limbic seizures and pathophysiological changes in adult rats that are very similar to human temporal lobe epilepsy. One of the earliest changes in gene expression after treatment with KA is the induction of immediate-early genes. The fos and jun families are frequently studied immediate-early genes that are induced by KA. Several groups, including ours, have recently reported that a 35-kDa Fos-related antigen (FRA) is induced for a protracted time by various stimuli. It has been suggested that this FRA is delta FosB, which has a molecular mass of approximately 35 kDa. The present study characterizes the long-term expression of FRA and delta FosB after systemic treatment with KA. Immunocytochemistry and western blot analysis using an antibody that cross-reacts with all known FRAs showed that a 35-kDa FRA was induced at high levels in both the hippocampus and striatum for up to 1 month by KA. A semiquantitative PCR analysis showed that delta FosB was induced by KA, but its expression lasted for only 6 h. This result was also verified by northern blot analysis. These results suggested that the 35-kDa FRA with long-term elevated levels seen with western blot analysis and immunocytochemistry is a new species of the FRA and not delta FosB. The long-term expression of FRA in both the hippocampus and striatum may be associated with the pathophysiological changes after KA administration.

  13. ANTIGENIC PROMOTION

    Science.gov (United States)

    Wu, Chin-Yu; Cinader, Bernard

    1971-01-01

    Rabbits were immunized with p-azobenzene arsonic acid derivatives of human serum albumin (HA-As) or of dissociated keyhole limpet hemocyanin. The IgM response to the hapten was evaluated in terms of the number of hapten-specific plaque-forming cells in the lymph node draining the injection site. In some experiments, antibody was measured by agglutination of tanned and sensitized erythrocytes. The hapten response of animals immunized with HA-As was increased (promoting effect) when the animals were injected with one of several structurally unrelated macromolecules: keyhole limpet hemocyanin (KLH), horse spleen ferritin (HSF), lysozyme (Lys), alum-precipitated human gamma globulin (alum-precipitated HGG). Different macromolecules differed in the magnitude of the promoting effect they induced, e.g., promotion by the associated form of KLH was greater than that by the dissociated form; alum-precipitated HGG was a better promoter than was soluble HGG. The relative magnitude of promotion by different macromolecules (associated vs. dissociated KLH, alum-precipitated vs. soluble HGG) correlated with the relative magnitude of the carrier effect, as judged by the hapten response induced by p-azobenzene arsonic acid conjugated to various proteins. Promotion was detected by agglutination assay of circulating antibody, by plaque assay of cells from the popliteal lymph node draining the site of preinjection, but not by plaque assay of cells from the contralateral lymph node. Promotion was dependent on the dose of the promoting macromolecule and on the dose of the hapten-protein conjugate. It was not observed in animals tolerant to the promoting macromolecule. Inhibition (i.e. antigenic competition), rather than promotion, was observed upon a secondary response to the preinjected macromolecule or when the hapten-protein conjugate was incorporated in Freund's adjuvant. PMID:15776570

  14. Immune selection and within-host competition can structure the repertoire of variant surface antigens in Plasmodium falciparum -a mathematical model

    DEFF Research Database (Denmark)

    van Noort, Sander P; Nunes, Marta C; Weedall, Gareth D

    2010-01-01

    -studied VSA family is erythrocyte membrane protein 1 (PfEMP1). Each parasite genome encodes about 60 PfEMP1 variants, which are important virulence factors and major targets of host antibody responses. Transcriptional switching is the basis of clonal PfEMP1 variation and immune evasion. A relatively conserved......BACKGROUND: The evolutionary mechanisms structuring the expression pattern of variant surface antigen (VSA) families that allow pathogens to evade immune responses and establish chronic and repeated infections pose major challenges to theoretical research. In Plasmodium falciparum, the best...... evidence regarding VSAs, in particular PfEMP1, to formulate a mathematical model of the evolutionary mechanisms shaping VSA organization and expression patterns. The model integrates the transmission dynamics between hosts and the competitive interactions within hosts, based on the hypothesis that the VSAs...

  15. Differential induction of immunoglobulin G to Plasmodium falciparum variant surface antigens during the transmission season in Daraweesh, Sudan

    DEFF Research Database (Denmark)

    Nielsen, Morten A; Grevstad, Berit; A-Elgadir, Thoraya M E

    2005-01-01

    BACKGROUND: The acquisition of immunoglobulin (Ig) G to variant surface antigens (VSAs) seems important for the development of protective immunity against malaria. Unlike VSAs expressed by parasite isolates associated with uncomplicated malaria, VSAs expressed by parasite isolates associated...... with severe malaria (VSA(SM)) are frequently recognized by IgG. METHODS: We analyzed levels of anti-VSA IgG in 57 individuals in Daraweesh, Sudan, before and after the transmission season. IgG responses to 79 Plasmodium falciparum isolates from children with defined malaria syndromes and exposed to high......G. CONCLUSIONS: Anti-VSA IgG levels decrease in the absence of infection, and an episode of clinical malaria induces IgG against a range of VSAs, particularly VSAs(SM)....

  16. The hybrid EIA test: a specific and sensitive assay for the detection of woodchuck antibody to hepatitis surface antigen (anti-WHs).

    Science.gov (United States)

    Millman, I; Glass, R G

    1988-05-01

    'Ausria II' polystyrene beads (Abbott Labs, N. Chicago) are reacted with woodchuck serum positive for WHsAg in a dilution predetermined by titration. This modified bead is used in a blocking assay to detect the presence of antibody to the surface antigen of woodchuck hepatitis virus (anti-WHs). Serum containing woodchuck anti-WHs and commercial horseradish peroxidase (HRP) labeled anti-HBs are sequentially added. A drop in optical density at 492 nm of 50% or more due to the blocking of HRP conjugated anti-HBs by anti-WHs compared with a control (negative woodchuck serum) is a measure of anti-WHs. The ease and simplicity of converting readily available 'Ausria II' beads to specific reagents for detecting anti-WHs should be welcomed by investigators studying WHV. The method described is both sensitive and reproducible.

  17. Enhancing recovery of recombinant hepatitis B surface antigen in lab-scale and large-scale anion-exchange chromatography by optimizing the conductivity of buffers.

    Science.gov (United States)

    Mojarrad Moghanloo, Gol Mohammad; Khatami, Maryam; Javidanbardan, Amin; Hosseini, Seyed Nezamedin

    2018-01-01

    In biopharmaceutical science, ion-exchange chromatography (IEC) is a well-known purification technique to separate the impurities such as host cell proteins from recombinant proteins. However, IEC is one of the limiting steps in the purification process of recombinant hepatitis B surface antigen (rHBsAg), due to its low recovery rate (rate of 82% in both lab-scale and large-scale weak anion-exchange chromatography without any harsh effect on the purity percentage of rHBsAg. The recovery enhancement via increasing the conductivity of Eq. and Wash. buffers can be explained by their roles in reducing the binding strength and aggregation of retained particles in the column. Moreover, further increase in the salt concentration of Elut. Buffer could substantially promote the ion exchange process and the elution of retained rHBsAg. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Maternally transmitted antibodies to pregnancy-associated variant antigens on the surface of erythrocytes infected with Plasmodium falciparum: relation to child susceptibility to malaria

    DEFF Research Database (Denmark)

    Cot, Michel; Le Hesran, Jean Yves; Staalsoe, Trine

    2003-01-01

    of antibodies in variable surface antigens (VSA) specific to chondroitin sulfate A (CSA)-binding parasites to assess the parasitologic status of the child. Flow cytometry was used to measure levels of antibodies to VSA from CSA-selected and -unselected parasite lines in the cord blood of 79 newborns in Ebolowa......, Cameroon. These newborns were subsequently followed up for 2 years to determine the date of first occurrence of blood parasites and mean parasite density during follow-up. Maternally transmitted antibodies to VSA expressed by CSA-binding parasites, but not antibodies to any other specificity, were...... negatively related to time of first appearance of Plasmodium falciparum in a child's blood and were positively related to mean parasite density during the first 2 years of life. If maternal infection is thought to be the main mechanism influencing susceptibility of the newborn to malaria, antibodies to VSA...

  19. Toward a network model of MHC class II-restricted antigen processing

    Directory of Open Access Journals (Sweden)

    Laurence C Eisenlohr

    2013-12-01

    Full Text Available The standard model of Major Histocompatibility Complex class II (MHCII-restricted antigen processing depicts a straightforward, linear pathway: Internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4+ T cells (TCD4+. Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while proposing that MHCII processing be thought of less in terms of discrete pathways and more in terms of a network whose major and minor conduits are variable depending upon many factors, including the epitope, the nature of the antigen, the source of the antigen, and the identity of the antigen-presenting cell.

  20. Long-term follow up of cervical cancer patients with unexplained squamous cell carcinoma antigen elevation after post-therapy surveillance using positron emission tomography.

    Science.gov (United States)

    Jao, Mei-Shan; Chang, Ting-Chang; Chang, Hsiu-Ping; Wu, Tzu-I; Chao, Angel; Lai, Chyong-Huey

    2010-10-01

    We aimed to define the long-term follow-up results in cervical cancer patients with unexplained squamous cell carcinoma antigen (SCC-Ag) elevation (negative conventional imaging studies, computed tomography or magnetic resonance imaging) after definitive treatment using positron emission tomography (PET). Of the 27 women with unexplained SCC-Ag elevation, 13 died or were alive with disease (12 PET true-positive, one PET false-negative) in our previous report. In this study, we reported long-term follow-up results for all the 14 patients remaining cancer-free at cut-off of our previous analysis (seven with true-negative PET and two with false-positive PET, and five with true-positive PET having received successful curative salvage therapy). The seven patients with true-negative PET studies remained recurrence-free (median follow up, 70 months; range, 11-84). Two patients had pelvic inflammatory disease; their SCC-Ag levels returned to the normal range after eradication of infection. Two other patients had recurrent cystitis, and their SCC-Ag levels normalized at 5 and 36 months, respectively. The two patients with false-positive PET/computed tomography were disease-free 73.5 and 70 months from original PET studies, respectively. In contrast, of the five patients with successful salvage, two are alive without disease (at 80 and 86.7 months), one died of radiation cystitis at 54 months, and two died of their cancer subsequent to previous analysis. Cystitis or pelvic inflammatory disease may cause unexplained elevation of SCC-Ag after definitive treatment. A negative PET study usually indicates absence of disease. PET is a useful tool to identify curable recurrences, especially when SCC-Ag < 4 ng/mL. © 2010 The Authors. Journal of Obstetrics and Gynaecology Research © 2010 Japan Society of Obstetrics and Gynecology.

  1. Establishment of a common acute lymphoblastic leukemia cell line (LC4-1) and effects of phorbol myristate acetate (PMA) on the surface antigen expression of the cell line.

    Science.gov (United States)

    Yoshimura, T; Mayumi, M; Yorifuji, T; Kim, K M; Heike, T; Miyanomae, T; Shinomiya, K; Mikawa, H

    1987-09-01

    A common acute lymphoblastic leukemia (ALL) cell line, designated LC4-1, was established from peripheral blood mononuclear cells of a patient with acute non-T-cell ALL. LC4-1 cells were characteristically positive for Ia, B4, and common ALL antigens (CALLA), but negative for B2, Tac, T3, T4, T8, T11, and M1 antigens and E-rosette formation. Approximately 30% of LC4-1 cells expressed detectable amounts of B1 antigens. LC4-1 cells expressed neither Epstein-Barr-virus-associated nuclear antigen (EBNA), cytoplasmic immunoglobulins (cIg) nor surface immunoglobulins (sIg). Gene rearrangements had already occurred in LC4-1 in the D-J region of immunoglobulin heavy chain genes, but not in T-cell receptor (beta-chain) genes, suggesting that LC4-1 is a progenitor cell line of B-cell lineage earlier than pre-B-cells. The expression of cell surface antigens of LC4-1 was changed by treatment with 4-phorbol 12-myristate 13-acetate (PMA) (0.1 ng/ml) for 2 days. Before treatment with PMA, about 98% of LC4-1 cells were positive for B4, CALLA, and Ia. However, following treatment they lost CALLA expression without any change in expression of Ia and B4. There was no change in B1-positive population. The change in surface antigens on LC4-1 cells seems to be due to differentiation induced in the cells by PMA. These results support the hypothesis that CALLA is a differentiation antigen and suggest one possible differentiation pathway for pre-B-cells.

  2. Long-term Surface Temperature (LoST) Database as a Complement for GCM Preindustrial Simulations

    Science.gov (United States)

    Cuesta-Valero, F. J.; García-García, A.; Beltrami, H.; Zorita, E.

    2017-12-01

    Control climate simulations aim to provide a stationary state to General Circulation Models (GCMs) under constant preindustrial conditions (piControl simulations). This stationary state is then used as initial conditions in GCM simulations to provide a stable and realistic climatology, reducing the potential bias in such simulations. However, it is difficult to provide a reference to assess the climatology of piControl simulations due to the lack of long-term preindustrial observations. We explore the use of long-term ground surface temperature estimates from borehole temperature profiles as an additional reference that may be useful for the initialization procedure of GCM simulations. We compare five last millennium simulations and five preindustrial control simulations from the third phase of the Palaeoclimate Modelling Intercomparison Project (PMIP3) and the fifth phase of the Coupled Model Intercomparison Project (CMIP5) archives against estimates of long-term preindustrial ground surface temperatures from 514 borehole temperature profiles over North America. These long-term surface temperatures are retrieved from the quasi-equilibrium state of the subsurface thermal regime in each temperature profile, which is estimated from the deepest section of the profile. That is, the equilibrium state is recovered from the least affected part of the temperature profile by the recent changes in the surface energy balance. The subsurface temperatures at the bottom part of each profile depend linearly on depth, and the extrapolation of this linear behavior to the surface is interpreted as the long-term surface temperature (T0 temperature) at each borehole site. Our results suggest that the ground surface temperature estimates from borehole data could be employed as a reference within piControl simulations to enhance the quality of the initial conditions in GCM climate simulations.

  3. Curcumin induced nanoscale CD44 molecular redistribution and antigen-antibody interaction on HepG2 cell surface

    Energy Technology Data Exchange (ETDEWEB)

    Wang Mu [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Ruan Yuxia [Department of Ophthalmology, The First Affiliated Hospital, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Xing Xiaobo; Chen Qian; Peng, Yuan [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Cai Jiye, E-mail: tjycai@jnu.edu.cn [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China)

    2011-07-04

    Graphical abstract: Highlights: > In this study, we investigate the changes of CD44 expression and distribution on HepG2 cells after curcumin treatment. > We find curcumin is able to change the morphology and ultrastructure of HepG2 cells. > Curcumin can reduce the expression of CD44 molecules and induce the nanoscale molecular redistribution on cell surface. > The binding force between CD44-modified AFM tip and the HepG2 cell surface decreases after curcumin-treatment. - Abstract: The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 {+-} 4.62 nm to 129.70 {+-} 43.72 nm) and the expression of CD44 decreased (99.79 {+-} 0.16% to 75.14 {+-} 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 {mu}M curcumin-treated) and 50-120 pN (20 {mu}M curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.

  4. Curcumin induced nanoscale CD44 molecular redistribution and antigen-antibody interaction on HepG2 cell surface

    International Nuclear Information System (INIS)

    Wang Mu; Ruan Yuxia; Xing Xiaobo; Chen Qian; Peng, Yuan; Cai Jiye

    2011-01-01

    Graphical abstract: Highlights: → In this study, we investigate the changes of CD44 expression and distribution on HepG2 cells after curcumin treatment. → We find curcumin is able to change the morphology and ultrastructure of HepG2 cells. → Curcumin can reduce the expression of CD44 molecules and induce the nanoscale molecular redistribution on cell surface. → The binding force between CD44-modified AFM tip and the HepG2 cell surface decreases after curcumin-treatment. - Abstract: The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 ± 4.62 nm to 129.70 ± 43.72 nm) and the expression of CD44 decreased (99.79 ± 0.16% to 75.14 ± 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 μM curcumin-treated) and 50-120 pN (20 μM curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.

  5. Virus-like particle production with yeast: ultrastructural and immunocytochemical insights into Pichia pastoris producing high levels of the Hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    Adnan Ahmad

    2011-06-01

    Full Text Available Abstract Background A protective immune response against Hepatitis B infection can be obtained through the administration of a single viral polypeptide, the Hepatitis B surface antigen (HBsAg. Thus, the Hepatitis B vaccine is generated through the utilization of recombinant DNA technology, preferentially by using yeast-based expression systems. However, the polypeptide needs to assemble into spherical particles, so-called virus-like particles (VLPs, to elicit the required protective immune response. So far, no clear evidence has been presented showing whether HBsAg assembles in vivo inside the yeast cell into VLPs or later in vitro during down-stream processing and purification. Results High level production of HBsAg was carried out with recombinant Pichia pastoris using the methanol inducible AOX1 expression system. The recombinant vaccine was isolated in form of VLPs after several down-stream steps from detergent-treated cell lysates. Search for the intracellular localization of the antigen using electron microscopic studies in combination with immunogold labeling revealed the presence of HBsAg in an extended endoplasmic reticulum where it was found to assemble into defined multi-layered, lamellar structures. The distance between two layers was determined as ~6 nm indicating that these lamellas represent monolayers of well-ordered HBsAg subunits. We did not find any evidence for the presence of VLPs within the endoplasmic reticulum or other parts of the yeast cell. Conclusions It is concluded that high level production and intrinsic slow HBsAg VLP assembly kinetics are leading to retention and accumulation of the antigen in the endoplasmic reticulum where it assembles at least partly into defined lamellar structures. Further transport of HBsAg to the Golgi apparatus is impaired thus leading to secretory pathway disfunction and the formation of an extended endoplasmic reticulum which bulges into irregular cloud-shaped formations. As VLPs were

  6. Surface Wettability in Terms of Prominence and Depression of Diverse Microstructures and Their Sizes

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Seon Woo; Lee, Sang Min; Jeong, Im Deok; Jung, Phill Gu; Ko, Jong Soo [Pusan National Univ., Busan (Korea, Republic of)

    2007-06-15

    Superhydrophobic surface, with a water contact angle greater than 150 .deg., has a self-cleaning effect termed 'Lotus effect'. This surface is created by the combination of rough surface and the low surface energy. We proposed square pillar and square shapes to control surface roughness. Microstructure arrays are fabricated by DRIE(Deep Reactive Ion Etching) process and followed by PPFC(Plasma Polymerized FluoroCarbon) deposition. On the experimental result, contact angle at square pillar arrays is well matched with Cassie's model and largest contact angle is 173.37 .deg.. But contact angle of square pore shape arrays is lower than Cassie's theoretical contact angle about 5{approx}10%. Nevertheless, square pore arrays have more rigidity than square pillar arrays.

  7. Immunogenetic markers associated with a naturally acquired humoral immune response against an N-terminal antigen of Plasmodium vivax merozoite surface protein 1 (PvMSP-1).

    Science.gov (United States)

    Cassiano, Gustavo Capatti; Furini, Adriana A C; Capobianco, Marcela P; Storti-Melo, Luciane M; Almeida, Maria E; Barbosa, Danielle R L; Póvoa, Marinete M; Nogueira, Paulo A; Machado, Ricardo L D

    2016-06-03

    Humoral immune responses against proteins of asexual blood-stage malaria parasites have been associated with clinical immunity. However, variations in the antibody-driven responses may be associated with a genetic component of the human host. The objective of the present study was to evaluate the influence of co-stimulatory molecule gene polymorphisms of the immune system on the magnitude of the humoral immune response against a Plasmodium vivax vaccine candidate antigen. Polymorphisms in the CD28, CTLA4, ICOS, CD40, CD86 and BLYS genes of 178 subjects infected with P. vivax in an endemic area of the Brazilian Amazon were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The levels of IgM, total IgG and IgG subclasses specific for ICB2-5, i.e., the N-terminal portion of P. vivax merozoite surface protein 1 (PvMSP-1), were determined by enzyme-linked immuno assay. The associations between the polymorphisms and the antibody response were assessed by means of logistic regression models. After correcting for multiple testing, the IgG1 levels were significantly higher in individuals recessive for the single nucleotide polymorphism rs3116496 in CD28 (p = 0.00004). Furthermore, the interaction between CD28 rs35593994 and BLYS rs9514828 had an influence on the IgM levels (p = 0.0009). The results of the present study support the hypothesis that polymorphisms in the genes of co-stimulatory components of the immune system can contribute to a natural antibody-driven response against P. vivax antigens.

  8. Cesarean section reduces perinatal transmission of hepatitis B virus infection from hepatitis B surface antigen-positive women to their infants.

    Science.gov (United States)

    Pan, Calvin Q; Zou, Huai-Bin; Chen, Yu; Zhang, Xiaohui; Zhang, Hua; Li, Jie; Duan, Zhongping

    2013-10-01

    Despite appropriate passive and active immunization, perinatal transmission of hepatitis B virus (HBV) still occurs in 5%-10% of infants born to women with high levels of viremia who test positive for the hepatitis B e antigen (HBeAg). We evaluated the effects of cesarean section delivery on perinatal transmission of HBV from women who tested positive for the hepatitis B surface antigen (HBsAg). We analyzed data from 1409 infants born to HBsAg-positive mothers through vaginal delivery (VD) (n = 673), elective caesarean section (ECS) (n = 496), or urgent cesarean section (UCS) (n = 240) who completed appropriate immunization against HBV. The prevention was assumed to have failed for infants who were HBsAg positive when they were 7-12 months old; this information was used to assess transmission rates. HBV infection was transmitted to a smaller percentage of infants born by ECS (1.4%) than by VD (3.4%, P infection to their infants, regardless of method of delivery. There were no differences in maternal or infant morbidity and mortality among the groups. There is a significantly lower rate of vertical transmission of HBV infection to infants delivered by ECS, compared with those delivered vaginally or by UCS. Elective cesarean sections for HBeAg-positive mothers with pre-delivery levels of HBV DNA ≥1,000,000 copies/mL could reduce vertical transmission. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

  9. New amperometric and potentiometric immunosensors based on gold nanoparticles/tris(2,2'-bipyridyl)cobalt(III) multilayer films for hepatitis B surface antigen determinations.

    Science.gov (United States)

    Tang, Dianping; Yuan, Ruo; Chai, Yaqin; Fu, Yingzi; Dai, Jianyuan; Liu, Yan; Zhong, Xia

    2005-10-15

    Two generic, fast, sensitive and novel electrochemical immunosensors have been developed. Initially, a layer of plasma-polymerized Nafion film (PPF) was deposited on the platinum electrode surface, then positively charged tris(2,2'-bipyridyl)cobalt(III) (Co(bpy)(3)(3+)) and negatively charged gold nanoparticles were assembled on the PPF-modified Pt electrode by layer-by-layer technique. Finally, hepatitis B surface antibody (HBsAb) was electrostatically adsorbed on the gold nanoparticles surface. Electrochemical behavior of the {Au/Co(bpy)(3)(3+)}(n) multilayer film-modified electrodes was studied. Cyclic voltammetry, electrochemical impedance spectroscopy (EIS) were adopted to monitor the regular growth of the multilayer films. The performance and factors influencing the performance of the resulting immunosensors were studied in detail. The multilayer film-modified immunosensor was used for hepatitis B surface antigen (HBsAg) determination via the amperometric and potentiometric immunosensor systems, and both systems provided the same linear ranges from 0.05 to 4.5 microg/mL with different detection limits for the amperometric system 0.005 microg/mL and for the potentiometric system 0.015 microg/mL. The immunosensors were used to analyse HBsAg in human serum samples. Analytical results of clinical samples show that the developed immunoassay is comparable with the enzyme-linked immunosorbent assays (ELISAs) method, implying a promising alternative approach for detecting HBsAg in the clinical diagnosis. In addition, the multilayer films also showed better stability for 1 month at least.

  10. Long-Term Effects of Antibodies Against Human Leukocyte Antigens Detected by Flow Cytometry in the First Year After Renal Transplantation

    Directory of Open Access Journals (Sweden)

    Tülay Kılıçaslan Ayna

    2013-03-01

    Full Text Available Objective: In this study, we aimed to investigate the incidence, dynamics and profiles of human leukocyte antigen (HLA-directed antibodies developed after transplantation and their impact on graft rejection and outcome in kidney recipients. Study Design: Prospective follow-up study. Material and Methods: A total of 56 kidney recipients were monitored at 1st, 6th and 12th months for the development of anti-HLA antibodies using bead based flow-cytometry assays (Flow PRA tests. Results: In 21 (37.5% patients, panel reactive antibodies (PRA was positive after transplantation, however, in 35 (62.5% patients PRA was found negative. Twelve (57.1% patients with post-transplantation HLA-reactive antibodies [PRA (+] and 8 (22.9% patients with no detectable alloantibodies [PRA (-] were developed allograft rejection (p=0.010. In the PRA positive patient group the rates of early period infection and delayed graft function (DGF were higher than the PRA negative patient group. Serum creatinine levels of PRA positive group at 6. and 12. months after transplantation were significantly higher than the PRA negative group (p=0.015 and p=0.048, respectively. The rejection rates of patients who had class I and II HLA antibodies were significantly higher than the patients who had either class I or II HLA antibodies (p=0.011. Acute rejection rates were significantly higher in patients who had class I and II HLA antibodies at the first month (p=0.007. Conclusion: Higher occurrence of rejection episodes in PRA positive group may show the importance of anti-HLA antibody monitoring using Flow-PRA after renal transplantation as a prognostic marker in terms of graft survival.

  11. High-resolution mapping of global surface water and its long-term changes

    Science.gov (United States)

    Pekel, Jean-François; Cottam, Andrew; Gorelick, Noel; Belward, Alan S.

    2016-12-01

    The location and persistence of surface water (inland and coastal) is both affected by climate and human activity and affects climate, biological diversity and human wellbeing. Global data sets documenting surface water location and seasonality have been produced from inventories and national descriptions, statistical extrapolation of regional data and satellite imagery, but measuring long-term changes at high resolution remains a challenge. Here, using three million Landsat satellite images, we quantify changes in global surface water over the past 32 years at 30-metre resolution. We record the months and years when water was present, where occurrence changed and what form changes took in terms of seasonality and persistence. Between 1984 and 2015 permanent surface water has disappeared from an area of almost 90,000 square kilometres, roughly equivalent to that of Lake Superior, though new permanent bodies of surface water covering 184,000 square kilometres have formed elsewhere. All continental regions show a net increase in permanent water, except Oceania, which has a fractional (one per cent) net loss. Much of the increase is from reservoir filling, although climate change is also implicated. Loss is more geographically concentrated than gain. Over 70 per cent of global net permanent water loss occurred in the Middle East and Central Asia, linked to drought and human actions including river diversion or damming and unregulated withdrawal. Losses in Australia and the USA linked to long-term droughts are also evident. This globally consistent, validated data set shows that impacts of climate change and climate oscillations on surface water occurrence can be measured and that evidence can be gathered to show how surface water is altered by human activities. We anticipate that this freely available data will improve the modelling of surface forcing, provide evidence of state and change in wetland ecotones (the transition areas between biomes), and inform water

  12. The extracellular membrane-proximal domain of membrane-bound IgE restricts B cell activation by limiting B cell antigen receptor surface expression.

    Science.gov (United States)

    Vanshylla, Kanika; Opazo, Felipe; Gronke, Konrad; Wienands, Jürgen; Engels, Niklas

    2018-03-01

    Immunoglobulin E (IgE) antibodies are key mediators of allergic reactions. Due to their potentially harmful anaphylactic properties, their production is tightly regulated. The membrane-bound isoform of IgE (mIgE), which is an integral component of the B cell antigen receptor, has been shown to be critical for the regulation of IgE responses in mice. In primate species including humans, mIgE can be expressed in two isoforms that are produced by alternative splicing of the primary ε Ig heavy chain transcript, and differ in the absence or presence of an extracellular membrane-proximal domain (EMPD) consisting of 52 amino acids. However, the function of the EMPD remains unclear. Here, we demonstrate that the EMPD restricts surface expression of mIgE-containing BCRs in human and murine B cells. The EMPD does not interfere with BCR assembly but acts as an autonomous endoplasmic reticulum retention domain. Limited surface expression of EMPD-containing mIgE-BCRs caused impaired activation of intracellular signaling cascades and hence represents a regulatory mechanism that may control the production of potentially anaphylactic IgE antibodies in primate species. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Short term memory for single surface features and bindings in ageing: A replication study.

    Science.gov (United States)

    Isella, Valeria; Molteni, Federica; Mapelli, Cristina; Ferrarese, Carlo

    2015-06-01

    In the present study we replicated a previous experiment investigating visuo-spatial short term memory binding in young and older healthy individuals, in the attempt to verify the pattern of impairment that can be observed in normal elderly for short term memory for single items vs short term memory for bindings. Assessing a larger sample size (25 young and 25 older subjects), using a more appropriate measure of accuracy for a change detection task (A'), and adding the evaluation of speed of performance, we confirmed that old normals show a decline in short term memory for bindings of shape and colour that is of comparable extent, and not major, to the decline in memory for single shapes and single colours. The absence of a specific deficit of short term memory for conjunctions of surface features seems to distinguish cognitive ageing from Alzheimer's Disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Natural Killer Cell Characteristics in Patients With Chronic Hepatitis B Virus (HBV) Infection Are Associated With HBV Surface Antigen Clearance After Combination Treatment With Pegylated Interferon Alfa-2a and Adefovir

    NARCIS (Netherlands)

    Stelma, Femke; de Niet, Annikki; Tempelmans Plat-Sinnige, Marjan J.; Jansen, Louis; Takkenberg, R. Bart; Reesink, Hendrik W.; Kootstra, Neeltje A.; van Leeuwen, Ester M. M.

    2015-01-01

    The role of natural killer (NK) cells in the process of hepatitis B virus (HBV) surface antigen (HBsAg) clearance and whether their phenotype is related to treatment outcome in patients with chronic hepatitis B are currently unknown. Patients with chronic hepatitis B (HBV DNA load, >17 000 IU/mL)

  15. Cationic Lipid-Formulated DNA Vaccine against Hepatitis B Virus : Immunogenicity of MIDGE-Th1 Vectors Encoding Small and Large Surface Antigen in Comparison to a Licensed Protein Vaccine

    NARCIS (Netherlands)

    Endmann, Anne; Klunder, Katharina; Kapp, Kerstin; Riede, Oliver; Oswald, Detlef; Talman, Eduard G.; Schroff, Matthias; Kleuss, Christiane; Ruiters, Marcel H. J.; Juhls, Christiane

    2014-01-01

    Currently marketed vaccines against hepatitis B virus (HBV) based on the small (S) hepatitis B surface antigen (HBsAg) fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible

  16. Long-term variations in the surface air 7Be concentration and climatic changes.

    Science.gov (United States)

    Jiwen, Liu; Starovoitova, Valeriia N; Wells, Douglas P

    2013-02-01

    We have used EML Surface Air Sampling Program (SASP) data to analyze the long-term trend in (7)Be surface concentration and address possible correlation between this long-term trend and climatic changes, namely changes in precipitation patterns and temperature. In this paper we present (7)Be concentration data from 23 sites, spanning over 25 years, all over the world, and extract long-term trend parameter using two independent techniques. The (7)Be concentrations in most stations show a pronounced decreasing trend, potentially corresponding to statistically significant changes in transporting (7)Be from upper atmosphere source to these sites. Weak negative correlation between (7)Be concentration and amount of precipitation was also observed. However, more data from more representative sites around the world are needed the statistical robustness of this trend. Published by Elsevier Ltd.

  17. Plasmodium falciparum variant surface antigen expression varies between isolates causing severe and nonsevere malaria and is modified by acquired immunity

    DEFF Research Database (Denmark)

    Nielsen, Morten A; Staalsoe, Trine; Kurtzhals, Jørgen

    2002-01-01

    of immunity, as disease-causing parasites appear to be those not controlled by preexisting VSA-specific Abs. In this work we report that VSA expressed by parasites from young Ghanaian children with P. falciparum malaria were commonly and strongly recognized by plasma Abs from healthy children in the same area......, and that the VSA expression pattern is modulated by immunity. This opens the possibility of developing morbidity-reducing vaccines targeting a limited subset of common and particularly virulent VSA.......In areas of endemic parasite transmission, protective immunity to Plasmodium falciparum malaria is acquired over several years with numerous disease episodes. Acquisition of Abs to parasite-encoded variant surface Ags (VSA) on the infected erythrocyte membrane is important in the development...

  18. Radioimmunoassays of hidden viral antigens

    International Nuclear Information System (INIS)

    Neurath, A.R.; Strick, N.; Baker, L.; Krugman, S.

    1982-01-01

    Antigens corresponding to infectious agents may be present in biological specimens only in a cryptic form bound to antibodies and, thus, may elude detection. We describe a solid-phase technique for separation of antigens from antibodies. Immune complexes are precipitated from serum by polyethylene glycol, dissociated with NaSCN, and adsorbed onto nitrocellulose or polystyrene supports. Antigens remain topographically separated from antibodies after removal of NaSCN and can be detected with radiolabeled antibodies. Genomes from viruses immobilized on nitrocellulose can be identified by nucleic acid hybridization. Nanogram quantities of sequestered hepatitis B surface and core antigens and picogram amounts of hepatitis B virus DNA were detected. Antibody-bound adenovirus, herpesvirus, and measles virus antigens were discerned by the procedure

  19. A leucine-rich repeat motif of Leishmania parasite surface antigen 2 binds to macrophages through the complement receptor 3.

    Science.gov (United States)

    Kedzierski, Lukasz; Montgomery, Jacqui; Bullen, Denise; Curtis, Joan; Gardiner, Elizabeth; Jimenez-Ruiz, Antonio; Handman, Emanuela

    2004-04-15

    Membrane glycoconjugates on the Leishmania parasites, notably leishmanolysin and lipophosphoglycan, have been implicated in attachment and invasion of host macrophages. However, the function of parasite surface Ag 2 (PSA-2) and membrane proteophosphoglycan (PPG) has not been elucidated. In this study we demonstrate that native and recombinant Leishmania infantum PSA-2, which consists predominantly of 15 leucine-rich repeats (LRR) and a recombinant LRR domain derived from L. major PPG, bind to macrophages. The interaction is restricted to macrophages and appears to be calcium independent. We have investigated the PSA-2-macrophage interaction to identify the host receptor involved in binding and we show that binding of PSA-2 to macrophages can be blocked by Abs to the complement receptor 3 (CR3, Mac-1). Data derived from mouse macrophage studies were further confirmed using cell lines expressing human CR3, and showed that PSA-2 also binds to the human receptor. This is the first demonstration of a functional role for PSA-2. Our data indicate that in addition to leishmanolysin and lipophosphoglycan, parasite attachment and invasion of macrophages involve a third ligand comprising the LRRs shared by PSA-2 and PPG and that these interactions occur via the CR3.

  20. Cell surface expression level variation between two common Human Leukocyte Antigen alleles, HLA-A2 and HLA-B8, is dependent on the structure of the C terminal part of the alpha 2 and the alpha 3 domains

    DEFF Research Database (Denmark)

    Dellgren, Christoffer; Nehlin, Jan O; Barington, Torben

    2015-01-01

    Constitutive cell surface expression of Human Leukocyte Antigen (HLA) class I antigens vary extremely from tissue to tissue and individual antigens may differ widely in expression levels. Down-regulation of class I expression is a known immune evasive mechanism used by cancer cells and viruses....... Moreover, recent observations suggest that even minor differences in expression levels may influence the course of viral infections and the frequency of complications to stem cell transplantation. We have shown that some human multipotent stem cells have high expression of HLA-A while HLA-B is only weakly...... expressed, and demonstrate here that this is also the case for the human embryonic kidney cell line HEK293T. Using quantitative flow cytometry and quantitative polymerase chain reaction we found expression levels of endogenous HLA-A3 (median 71,204 molecules per cell) 9.2-fold higher than the expression of...

  1. A Conserved DNA Repeat Promotes Selection of a Diverse Repertoire of Trypanosoma brucei Surface Antigens from the Genomic Archive.

    Directory of Open Access Journals (Sweden)

    Galadriel Hovel-Miner

    2016-05-01

    Full Text Available African trypanosomes are mammalian pathogens that must regularly change their protein coat to survive in the host bloodstream. Chronic trypanosome infections are potentiated by their ability to access a deep genomic repertoire of Variant Surface Glycoprotein (VSG genes and switch from the expression of one VSG to another. Switching VSG expression is largely based in DNA recombination events that result in chromosome translocations between an acceptor site, which houses the actively transcribed VSG, and a donor gene, drawn from an archive of more than 2,000 silent VSGs. One element implicated in these duplicative gene conversion events is a DNA repeat of approximately 70 bp that is found in long regions within each BES and short iterations proximal to VSGs within the silent archive. Early observations showing that 70-bp repeats can be recombination boundaries during VSG switching led to the prediction that VSG-proximal 70-bp repeats provide recombinatorial homology. Yet, this long held assumption had not been tested and no specific function for the conserved 70-bp repeats had been demonstrated. In the present study, the 70-bp repeats were genetically manipulated under conditions that induce gene conversion. In this manner, we demonstrated that 70-bp repeats promote access to archival VSGs. Synthetic repeat DNA sequences were then employed to identify the length, sequence, and directionality of repeat regions required for this activity. In addition, manipulation of the 70-bp repeats allowed us to observe a link between VSG switching and the cell cycle that had not been appreciated. Together these data provide definitive support for the long-standing hypothesis that 70-bp repeats provide recombinatorial homology during switching. Yet, the fact that silent archival VSGs are selected under these conditions suggests the 70-bp repeats also direct DNA pairing and recombination machinery away from the closest homologs (silent BESs and toward the rest of

  2. A recombinant multi-antigen vaccine formulation containing Babesia bovis merozoite surface antigens MSA-2a1, MSA-2b and MSA-2c elicits invasion-inhibitory antibodies and IFN-γ producing cells

    Directory of Open Access Journals (Sweden)

    Alba Marina Gimenez

    2016-11-01

    Full Text Available Abstract Background Babesia bovis is a tick-transmitted protozoan hemoparasite and the causative agent of bovine babesiosis, a potential risk to more than 500 million cattle worldwide. The vaccines currently available are based on attenuated parasites, which are difficult to produce, and are only recommended for use in bovines under one year of age. When used in older animals, these vaccines may cause life-threatening clinical symptoms and eventually death. The development of a multi-subunit recombinant vaccine against B. bovis would be attractive from an economic standpoint and, most importantly, could be recommended for animals of any age. In the present study, recombinant ectodomains of MSA-2a1, MSA-2b and MSA-2c antigens were expressed in Pichia pastoris yeast as secreted soluble peptides. Results The antigens were purified to homogeneity, and biochemically and immunologically characterized. A vaccine formulation was obtained by emulsifying a mixture of the three peptides with the adjuvant Montanide ISA 720, which elicited high IgG antibody titers against each of the above antigens. IgG antibodies generated against each MSA-antigen recognized merozoites and significantly inhibited the invasion of bovine erythrocytes. Cellular immune responses were also detected, which were characterized by splenic and lymph node CD4+ T cells producing IFN-γ and TNF-α upon stimulation with the antigens MSA-2a1 or MSA-2c. Conclusions These data strongly suggest the high protective potential of the presented formulation, and we propose that it could be tested in vaccination trials of bovines challenged with B. bovis.

  3. Identification of a rare point mutation at C-terminus of merozoite surface antigen-1 gene of Plasmodium falciparum in eastern Indian isolates.

    Science.gov (United States)

    Raj, Dipak Kumar; Das, Bibhu Ranjan; Dash, A P; Supakar, Prakash C

    2004-01-01

    Merozoite surface antigen-1 (MSA-1) of Plasmodium falciparum is highly immunogenic in human. Several studies suggest that MSA-1 protein is an effective target for a protective immune response. Attempt has been made to find new point mutations by analyzing 244 bp [codon 1655(R) to 1735 (I)] relatively conserved C-terminus region of MSA-1 gene in 125 isolates. This region contains two EGF like domains, which are involved in generating protective immune response in human. Point mutations in this region are very much important in view of vaccine development. Searching of mutational hot spots in MSA-1 protein by sequencing method in a representative number of isolates is quite critical and expensive. Therefore, in this study slot blot and PCR-SSCP method have been used to find out new mutations in the individual isolates showing alterations in the mobility of DNA fragment. Sequencing of the altered bands from the SSCP gel shows a rare non-synonymous point mutation in 7 (5.6%) of the 125 isolates at amino acid position 1704 of MSA-1 gene where isoleucine is replaced by valine.

  4. Response-guided therapy of regimens based on PEG-interferon for chronic hepatitis B using on-treatment hepatitis B surface antigen quantification: a meta-analysis.

    Science.gov (United States)

    Peng, Hong; Wei, Fang; Liu, Jun-Ying; Hu, Huai-Dong; Ren, Hong; Hu, Peng

    2015-10-01

    The efficacy of on-treatment hepatitis B surface antigen (HBsAg) levels in guiding pegylated interferon (PEG-IFN) therapy for chronic hepatitis B (CHB) infections is still controversial. The aim of this study is to quantitatively evaluate the efficacy of on-treatment HBsAg levels as a response-guided therapy strategy to guide PEG-IFN-based therapies for CHB. We searched PUBMED, EMBASE, and the Cochrane Library (1997-2013) for clinical research involving HBsAg quantification, and the response to PEG-IFN-based therapy. Pooled effect of HBsAg levels on guiding PEG-IFN-based therapies for CHB was evaluated using fixed-effects or random-effects model. From 13 studies (n = 1493 patients), patients with optimal on-treatment HBsAg levels were found to have a greater chance of attaining a response (RR 5.17, 95 % CI 3.75-7.11, p response rate was 54 % (95 % CI 44-63 %). At week 12, patients without optimal on-treatment HBsAg levels had hardly achieved a response (the early non-response rate: 99 %, 95 % CI 98-100 %). At 24 weeks, the response rate increased to 79 % in HBeAg-negative patients. This meta-analysis suggested that on-treatment HBsAg quantification is effective in guiding the therapy of PEG-IFN in CHB infections, especially in HBeAg-negative patients.

  5. IgA and IgG antibodies against surface antigens of Pseudomonas aeruginosa in sputum and serum from patients with cystic fibrosis.

    Science.gov (United States)

    Schiøtz, P O; Høiby, N; Permin, H; Wiik, A

    1979-06-01

    Eleven cystic fibrosis (CF) patients chronically infected in the lungs with mucoid Pseudomonas aeruginosa and presenting multiple precipitins in serum against this bacterium (CF + P) and 10 CF patients without P. aeruginosa infection (CF-P) had their serum and sputum sol phase specimens examined for antibodies of the IgA and IgG classes against surface antigens of P. aeruginosa by means of an indirect immunofluorescence technique. Both the IgA and IgG antibody titres demonstrated in serum and sputum of the CF + P patients were significantly higher than in those of the CF-P patients (p less than 0.01). The titre of IgA antibodies in the sputum was higher than in serum in 3 cases indicating local pulmonary production of specific IgA antibodies. The role of the demonstrated antibodies in the local pulmonary immune defense mechanisms and the possible patogenesis of the pulmonary tissue damage in CF patients is discussed.

  6. Antibody response to a major human Pneumocystis carinii surface antigen in patients without evidence of immunosuppression and in patients with suspected atypical pneumonia

    DEFF Research Database (Denmark)

    Lundgren, Bettina; Lebech, M; Lind, K

    1993-01-01

    G antibodies to gp95 was significantly lower in the age group 1 to 9 years (30%, 23/77) compared to persons 10 to 19 years old (56%, 49/88). In the age group 1 to 14 years there was a significant correlation between the percentage of persons with IgG antibodies to gp95 and age. In 106 consecutive patients...... of these patients had a verified Pneumocystis carinii pneumonia, and the two others were elderly men in whom no microbiological diagnosis of the pneumonia was established. Thus, it is concluded that IgG antibodies to gp95 develop in the majority of nonimmunosuppressed persons before the age of 13. Furthermore......IgG and IgM antibodies to a purified human Pneumocystis carinii surface antigen (gp95) were measured in 694 serum specimens from two different population groups using an EIA technique. In a population of 441 patients with no evidence of immunosuppression, the percentage of persons positive for Ig...

  7. Hepatitis B vaccination coverage and risk factors associated with incomplete vaccination of children born to hepatitis B surface antigen-positive mothers, Denmark, 2006 to 2010.

    Science.gov (United States)

    Kunoee, Asja; Nielsen, Jens; Cowan, Susan

    2016-01-01

    In Denmark, universal screening of pregnant women for hepatitis B has been in place since November 2005, with the first two years as a trial period with enhanced surveillance. It is unknown what the change to universal screening without enhanced surveillance has meant for vaccination coverage among children born to hepatitis B surface antigen (HBsAg)-positive mothers and what risk factors exist for incomplete vaccination. This retrospective cohort study included 699 children of mothers positive for HBsAg. Information on vaccination and risk factors was collected from central registers. In total, 93% (651/699) of the children were vaccinated within 48 hours of birth, with considerable variation between birthplaces. Only 64% (306/475) of the children had received all four vaccinations through their general practitioner (GP) at the age of two years, and 10% (47/475) of the children had received no hepatitis B vaccinations at all. Enhanced surveillance was correlated positively with coverage of birth vaccination but not with coverage at the GP. No or few prenatal examinations were a risk factor for incomplete vaccination at the GP. Maternity wards and GPs are encouraged to revise their vaccination procedures and routines for pregnant women, mothers with chronic HBV infection and their children.

  8. Radioimmunoassay of surface antigen and core antibody of hepatitis B virus. Comparison of kits AUSRIA/CORE; AUSRIA II-125 and CORAB

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M.; Urbankova, J. (Ustav Hematologie a Krevni Transfuze, Prague (Czechoslovakia))

    1984-08-01

    The sensitivity is compared of determination of surface antigen HBsAg and nuclear antibody HBcAb of the hepatitis B virus using kits for separate (AUSRIA II-125, CORAB) and simultaneous (AUSRIAsup(R)/CORE) determinations of third generation tests in selected samples of medical personnel, HBsAg carriers, patients at a dialysis centre, blood donors and in sera of HBsAg carriers diluted in steps from 4x10/sup -2/ to 4x10/sup -7/. HBsAg is always determined using the RIA technique, HBcAb is determined using the technique of radioimmunoassay with the CORAB kit and with the AUSRIA sup(R)/CORE kit using enzymeimmunoassay. The sensitivity of determination using the AUSRIA sup(R)/CORE kit is at least as good for both investigated indicators of the hepatitis B virus and that obtained using separate determination of HBsAg (AUSRIA II-125) and HBcAb (CORAB), this also using modified photocolorimetric determination. Only one AUSRIA/sup R//CORE kit was available for the investigation and the informative character of the report is emphasized.

  9. Noether Current of the Surface Term of Einstein-Hilbert Action, Virasoro Algebra, and Entropy

    Directory of Open Access Journals (Sweden)

    Bibhas Ranjan Majhi

    2013-01-01

    Full Text Available A derivation of Noether current from the surface term of Einstein-Hilbert action is given. We show that the corresponding charge, calculated on the horizon, is related to the Bekenstein-Hawking entropy. Also using the charge, the same entropy is found based on the Virasoro algebra and Cardy formula approach. In this approach, the relevant diffeomorphisms are found by imposing a very simple physical argument: diffeomorphisms keep the horizon structure invariant. This complements similar earlier results (Majhi and Padmanabhan (2012 (arXiv:1204.1422 obtained from York-Gibbons-Hawking surface term. Finally we discuss the technical simplicities and improvements over the earlier attempts and also various important physical implications.

  10. Geometrical quantization of bosonic string with Wess-Zumino term on genus-g Riemann surface

    International Nuclear Information System (INIS)

    Liu, Y.; Chen, S.; Ni, G.; Physics Department, Fudan University, Shanghai, China)

    1990-01-01

    By combining the method of geometrical quantization and Krichever and Novikov algebra, we study the holomorphic structure of a bosonic string with Wess-Zumino term on a genus-g Riemann surface Σ and arrive at the conclusion that the curvature on a Kaehler manifold is proportional to the central extension of Krichever and Novikov algebra on Σ and vanishes at the critical dimension d=26-(kd G )/(C V +k)

  11. Hepatitis B surface antigen titer is a good indicator of durable viral response after entecavir off-treatment for chronic hepatitis B.

    Science.gov (United States)

    Lee, Han Ah; Seo, Yeon Seok; Park, Seung Woon; Park, Sang Jung; Kim, Tae Hyung; Suh, Sang Jun; Jung, Young Kul; Kim, Ji Hoon; An, Hyunggin; Yim, Hyung Joon; Yeon, Jong Eun; Byun, Kwan Soo; Um, Soon Ho

    2016-09-01

    Clear indicators for stopping antiviral therapy in chronic hepatitis B (CHB) patients are not yet available. Since the level of hepatitis B surface antigen (HBsAg) is correlated with covalently closed circular DNA, the HBsAg titer might be a good indicator of the off-treatment response. This study aimed to determine the relationship between the HBsAg titer and the entecavir (ETV) off-treatment response. This study analyzed 44 consecutive CHB patients (age, 44.6±11.4 years, mean±SD; men, 63.6%; positive hepatitis B envelope antigen (HBeAg) at baseline, 56.8%; HBV DNA level, 6.8±1.3 log 10 IU/mL) treated with ETV for a sufficient duration and in whom treatment was discontinued after HBsAg levels were measured. A virological relapse was defined as an increase in serum HBV DNA level of >2000 IU/mL, and a clinical relapse was defined as a virological relapse with a biochemical flare, defined as an increase in the serum alanine aminotransferase level of >2 × upper limit of normal. After stopping ETV, virological relapse and clinical relapse were observed in 32 and 24 patients, respectively, during 20.8±19.9 months of follow-up. The cumulative incidence rates of virological relapse were 36.2% and 66.2%, respectively, at 6 and 12 months, and those of clinical relapse were 14.3% and 42.3%. The off-treatment HBsAg level was an independent factor associated with clinical relapse (hazard ratio, 2.251; 95% confidence interval, 1.076-4.706; P =0.031). When patients were grouped according to off-treatment HBsAg levels, clinical relapse did not occur in patients with an off-treatment HBsAg level of ≤2 log 10 IU/mL (n=5), while the incidence rates of clinical relapse at 12 months after off-treatment were 28.4% and 55.7% in patients with off-treatment HBsAg levels of >2 and ≤3 log 10 IU/mL (n=11) and >3 log 10 IU/mL (n=28), respectively. The off-treatment HBsAg level is closely related to clinical relapse after treatment cessation. A serum HBsAg level of response in CHB

  12. Hepatitis B surface antigen titer is a good indicator of durable viral response after entecavir off-treatment for chronic hepatitis B

    Directory of Open Access Journals (Sweden)

    Han Ah Lee

    2016-09-01

    Full Text Available Background/Aims Clear indicators for stopping antiviral therapy in chronic hepatitis B (CHB patients are not yet available. Since the level of hepatitis B surface antigen (HBsAg is correlated with covalently closed circular DNA, the HBsAg titer might be a good indicator of the off-treatment response. This study aimed to determine the relationship between the HBsAg titer and the entecavir (ETV off-treatment response. Methods This study analyzed 44 consecutive CHB patients (age, 44.6±11.4 years, mean±SD; men, 63.6%; positive hepatitis B envelope antigen (HBeAg at baseline, 56.8%; HBV DNA level, 6.8±1.3 log10 IU/mL treated with ETV for a sufficient duration and in whom treatment was discontinued after HBsAg levels were measured. A virological relapse was defined as an increase in serum HBV DNA level of >2000 IU/mL, and a clinical relapse was defined as a virological relapse with a biochemical flare, defined as an increase in the serum alanine aminotransferase level of >2 × upper limit of normal. Results After stopping ETV, virological relapse and clinical relapse were observed in 32 and 24 patients, respectively, during 20.8±19.9 months of follow-up. The cumulative incidence rates of virological relapse were 36.2% and 66.2%, respectively, at 6 and 12 months, and those of clinical relapse were 14.3% and 42.3%. The off-treatment HBsAg level was an independent factor associated with clinical relapse (hazard ratio, 2.251; 95% confidence interval, 1.076–4.706; P=0.031. When patients were grouped according to off-treatment HBsAg levels, clinical relapse did not occur in patients with an off-treatment HBsAg level of ≤2 log10 IU/mL (n=5, while the incidence rates of clinical relapse at 12 months after off-treatment were 28.4% and 55.7% in patients with off-treatment HBsAg levels of >2 and ≤3 log10 IU/mL (n=11 and >3 log10 IU/mL (n=28, respectively. Conclusion The off-treatment HBsAg level is closely related to clinical relapse after treatment

  13. Evaluation of protective immune responses induced by DNA vaccines encoding Toxoplasma gondii surface antigen 1 (SAG1) and 14-3-3 protein in BALB/c mice.

    Science.gov (United States)

    Meng, Min; He, Shenyi; Zhao, Guanghui; Bai, Yang; Zhou, Huaiyu; Cong, Hua; Lu, Gang; Zhao, Qunli; Zhu, Xing-Quan

    2012-11-26

    Toxoplasmosis, caused by an obligate intracellular protozoan parasite Toxoplasma gondii, has been a serious clinical and veterinary problem. Effective DNA vaccines against T. gondii can prevent and control the spread of toxoplasmosis, which is important for both human health and the farming industry. The T. gondii 14-3-3 protein has been proved to be antigenic and immunogenic and was a potential vaccine candidate against toxoplasmosis. In this study, we evaluated the immune responses induced by recombinant plasmids encoding T. gondii surface antigen 1 (SAG1) and 14-3-3 protein by immunizing BALB/c mice intramuscularly. In the present study, BALB/c mice were randomly divided into five groups, including three experimental groups (pSAG1, p14-3-3 and pSAG1/14-3-3) and two control groups (PBS and pBudCE4.1), and were immunized intramuscularly three times. The levels of IgG antibodies and cytokine production in mouse sera were determined by enzyme-linked immunosorbent assays (ELISA). Two weeks after the last immunization, all mice were challenged intraperitoneally (i.p.) with 1×10(4) tachyzoites of T. gondii and the survival time of mice was observed and recorded every day. Mice vaccinated with pSAG1, p14-3-3 or pSAG1/14-3-3 developed high levels of IgG2a and gamma interferon (IFN-γ) and low levels of interleukin-4 (IL-4) and interleukin-10 (IL-10) compared to control groups (PBS or pBudCE4.1), which suggested a modulated Th1 type immune response (Pmice in experimental groups was longer than control groups (Pmice and was a novel DNA vaccine candidate against toxoplasmosis, and the immune protective efficacy elicited by SAG1 gene was also demonstrated. Our results also showed multi-gene vaccine significantly enhanced immune responses and protective efficacy and was superior to the single-gene vaccine.

  14. Harmonisation of short-term in vitro culture for the expansion of antigen-specific CD8(+) T cells with detection by ELISPOT and HLA-multimer staining.

    Science.gov (United States)

    Chudley, Lindsey; McCann, Katy J; Coleman, Adam; Cazaly, Angelica M; Bidmon, Nicole; Britten, Cedrik M; van der Burg, Sjoerd H; Gouttefangeas, Cecile; Jandus, Camilla; Laske, Karoline; Maurer, Dominik; Romero, Pedro; Schröder, Helene; Stynenbosch, Linda F M; Walter, Steffen; Welters, Marij J P; Ottensmeier, Christian H

    2014-11-01

    Ex vivo ELISPOT and multimer staining are well-established tests for the assessment of antigen-specific T cells. Many laboratories are now using a period of in vitro stimulation (IVS) to enhance detection. Here, we report the findings of a multi-centre panel organised by the Association for Cancer Immunotherapy Immunoguiding Program to investigate the impact of IVS protocols on the detection of antigen-specific T cells of varying ex vivo frequency. Five centres performed ELISPOT and multimer staining on centrally prepared PBMCs from 3 donors, both ex vivo and following IVS. A harmonised IVS protocol was designed based on the best-performing protocol(s), which was then evaluated in a second phase on 2 donors by 6 centres. All centres were able to reliably detect antigen-specific T cells of high/intermediate frequency both ex vivo (Phase I) and post-IVS (Phase I and II). The highest frequencies of antigen-specific T cells ex vivo were mirrored in the frequencies following IVS and in the detection rates. However, antigen-specific T cells of a low/undetectable frequency ex vivo were not reproducibly detected post-IVS. Harmonisation of the IVS protocol reduced the inter-laboratory variation observed for ELISPOT and multimer analyses by approximately 20 %. We further demonstrate that results from ELISPOT and multimer staining correlated after (P < 0.0001 and R (2) = 0.5113), but not before IVS. In summary, IVS was shown to be a reproducible method that benefitted from method harmonisation.

  15. Long-term efficacy of denture cleansers in preventing Candida spp. biofilm recolonization on liner surface.

    Science.gov (United States)

    Vieira, Ana Paula Coelho; Senna, Plínio Mendes; Silva, Wander José da; Del Bel Cury, Altair Antoninha

    2010-01-01

    This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate)-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min), 0.5% sodium hypochlorite (10 min) or distilled water (control; 15 min). After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL). Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05). Results of cell count estimation showed significant differences in cleanliness among the treatments (p 0.05) was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p denture liner surfaces and preventing biofilm recolonization.

  16. Long-term efficacy of denture cleansers in preventing Candida spp. biofilm recolonization on liner surface

    Directory of Open Access Journals (Sweden)

    Ana Paula Coelho Vieira

    2010-09-01

    Full Text Available This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min, 0.5% sodium hypochlorite (10 min or distilled water (control; 15 min. After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL. Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05. Results of cell count estimation showed significant differences in cleanliness among the treatments (p 0.05 was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p < 0.001. Sodium hypochlorite was the only treatment that removed biofilm efficiently, since no viable cells were found after its use. In conclusion, alkaline peroxide denture cleansers were not effective in removing Candida spp. biofilm from denture liner surfaces and preventing biofilm recolonization.

  17. Spatial distributions of Southern Ocean mesozooplankton communities have been resilient to long-term surface warming.

    Science.gov (United States)

    Tarling, Geraint A; Ward, Peter; Thorpe, Sally E

    2018-01-01

    The biogeographic response of oceanic planktonic communities to climatic change has a large influence on the future stability of marine food webs and the functioning of global biogeochemical cycles. Temperature plays a pivotal role in determining the distribution of these communities and ocean warming has the potential to cause major distributional shifts, particularly in polar regions where the thermal envelope is narrow. We considered the impact of long-term ocean warming on the spatial distribution of Southern Ocean mesozooplankton communities through examining plankton abundance in relation to sea surface temperature between two distinct periods, separated by around 60 years. Analyses considered 16 dominant mesozooplankton taxa (in terms of biomass and abundance) in the southwest Atlantic sector of the Southern Ocean, from net samples and in situ temperature records collected during the Discovery Investigations (1926-1938) and contemporary campaigns (1996-2013). Sea surface temperature was found to have increased significantly by 0.74°C between the two eras. The corresponding sea surface temperature at which community abundance peaked was also significantly higher in contemporary times, by 0.98°C. Spatial projections indicated that the geographical location of community peak abundance had remained the same between the two eras despite the poleward advance of sea surface isotherms. If the community had remained within the same thermal envelope as in the 1920s-1930s, community peak abundance would be 500 km further south in the contemporary era. Studies in the northern hemisphere have found that dominant taxa, such as calanoid copepods, have conserved their thermal niches and tracked surface isotherms polewards. The fact that this has not occurred in the Southern Ocean suggests that other selective pressures, particularly food availability and the properties of underlying water masses, place greater constraints on spatial distributions in this region. It

  18. The surface expression of HLA-F on decidual trophoblasts increases from mid to term gestation.

    Science.gov (United States)

    Shobu, Takanori; Sageshima, Noriko; Tokui, Hiroshi; Omura, Motoko; Saito, Keigo; Nagatsuka, Yuka; Nakanishi, Mari; Hayashi, Yukio; Hatake, Katsuhiko; Ishitani, Akiko

    2006-12-01

    HLA-F has recently only begun to be studied in earnest, and has been thought not to be expressed on the cell surface. However, in our previous report, we demonstrated surface expression of HLA-F on extravillous trophoblasts (EVTs) invading the decidua in term placental tissues. To better understand its function, we attempted to determine when surface expression of HLA-F begins during normal pregnancy, and whether there is a difference in expression between normal and preeclamptic placentas, by comparing the expression of HLA-G and -E by immunohistochemical staining with anti-HLA-E, -F and -G antibodies (3D12, 3D11 and 87G, respectively). In EVTs, HLA-F was expressed only in the cytoplasm weakly during the first trimester, after which expression increased and moved to the cell surface with the progression of pregnancy from the second trimester, which was confirmed by the results of double-labeled immunofluorescence staining with anti-HLA-F and anti-HLA-G antibodies, and by flow cytometry using trophoblasts isolated from the decidua. HLA-E showed similar expression as HLA-F, though it was expressed on the cell surface from the first trimester, while HLA-G was expressed strongly in the cytoplasm and on the cell surface during all stages of pregnancy. The expressions of HLA-E, -F and -G in preeclamptic placentas were not different from those in normal placentas, though there were a greater number of necrotic EVTs in preeclampsia. The increase in expression of HLA-E and HLA-F from the second trimester to full term was coincident with the timing of rapid growth of the fetus. Our results suggest that these may function together to prepare an environment that supports fetal growth.

  19. Amniotic membrane transplantation in surgical management of ocular surface squamous neoplasias: long-term results.

    Science.gov (United States)

    Palamar, M; Kaya, E; Egrilmez, S; Akalin, T; Yagci, A

    2014-09-01

    To evaluate the long-term efficacy of amniotic membrane transplantation for ocular surface reconstruction in the surgical management of ocular surface squamous neoplasia (OSSN). OSSN in 21 patients (7 female, 14 male patients) was managed with excisional biopsy, cryotherapy, corneal epitheliectomy with absolute alcohol application when the cornea is involved, lamellar sclerectomy and adjunctional absolute alcohol application to the base when episclera is involved, and ocular surface reconstruction with cryopreserved amniotic membrane transplantation. Tumor control and complications were evaluated. The mean age of the patients was 62.42 ± 20.9 (range, 16-84). The average diameter of the base of the tumors was 13.1 ± 4.8 (range, 9-21) mm and complete removal was achieved in all cases as revealed histopathologically. Ocular surface healing was achieved in all cases. At the postoperative period, limbal stem cell deficiency in three eyes and mild symblepharon in one eye were detected. In a mean follow-up of 30.95 ± 18.8 (range, 13-75) months, no recurrence was detected. For large or multifocal conjunctival tumors, the reconstruction of ocular surface and fornix is challenging. The amniotic-membrane use to repair conjunctival defects larger than 10 mm is a safe and effective technique with minimal complications allowing surgeons to make large enough excisions.

  20. Long-term sodium and chloride surface water exports from the Dallas/Fort Worth region.

    Science.gov (United States)

    Steele, M K; Aitkenhead-Peterson, J A

    2011-07-15

    Sodium and chloride in surface water are typically related to urbanization and population density and can have a significant impact on drinking water sources and the subsequent salinity of aquatic ecosystems. While the majority of research has focused on the impact of deicing salts on urban surface waters in colder climates, the effect of urbanization on sodium and chloride concentrations has been found to occur in warmer climates. This study investigated long-term exports of sodium and chloride from watersheds with increasing urbanization in the humid subtropical Dallas-Fort Worth region. We compared exports to characteristics of urbanization: urban land cover, impervious surface area, and calculated contributions from wastewater discharges. Long-term data (1980-2008) were obtained from five USGS gages located in and around the cities. Exports were calculated by regression analysis between concentrations and discharge and normalized for time and the watershed area. Grab samples were collected from June 2009 to May 2010 and sodium and chloride concentrations quantified. Our results show a strong positive relationship between the mean annual sodium and chloride exports from each watershed and the percent urban land cover and impervious surface area. Long-term increases in sodium and chloride fluxes were found for the three watersheds with the highest percentage of urban land cover. The single largest contributor was wastewater effluent that was estimated to contribute approximately half of the total loads in the three urbanized watersheds. Atmospheric deposition and deicing salts accounted for small amounts of the total export for urbanized watersheds. The source of the remaining salt load is still unknown and may be a combination of non-point sources. Estimates of urban salt exports were similar to estimates from northern watersheds affected by deicing salts. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Polyaniline hybridized surface defective ZnO nanorods with long-term stable photoelectrochemical activity

    International Nuclear Information System (INIS)

    Bera, Susanta; Khan, Hasmat; Biswas, Indranil; Jana, Sunirmal

    2016-01-01

    Highlights: • Polyaniline (PANI) hybridized ZnO nanorods was synthesized by solution method. • Surface defects were found in the nanorods. • The hybrid material exhibited an enhancement in visible light absorption. • A long-term stable photoelectrochemical activity of the material was found. • Advancement in the properties would be PANI hybridization and surface defects. - Abstract: We report surfactant/template free precursor solution based synthesis of polyaniline (PANI) hybridized surface defective ZnO nanorods by a two-step process. Initially, ZnO nanorods have been prepared at 95 °C, followed by hybridization (coating) of PANI onto the ZnO via in situ polymerization of aniline monomer, forming ZnO-PANI nanohybrid (ZP). The structural properties of ZP have been analyzed by X-ray diffraction (XRD) and transmission electron microscopic (TEM) studies. The presence of surface defects especially the oxygen vacancies in ZnO has been characterized by photoluminescence emission, high resolution TEM, X-ray photoelectron spectroscopy (XPS) and micro-Raman spectral measurements. The chemical interaction of PANI with ZnO has been examined by Fourier transform infrared (FTIR) and XPS analyses. A significant enhancement in visible absorption of ZP sample is found as evidenced from UV–vis diffused reflectance spectral study. BET nitrogen adsorption-desorption isotherm shows an improved textural property (pore size, pore volume) of ZP. Moreover, a long-term stable photoelectrochemical activity (PEC) of ZP is found compare to pristine ZnO. The synergic effect of PANI hybridization and the presence of surface defects in ZnO NRs can enhance the PEC by prolonging the recombination rate of photogenerated charge carriers. The effect can also provide large number of active sites to make electrolyte diffusion and mass transportation easier in the nanohybrid. This simple synthesis strategy can be adopted for PANI hybridization with different metal oxide semiconductors

  2. Polyaniline hybridized surface defective ZnO nanorods with long-term stable photoelectrochemical activity

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Susanta; Khan, Hasmat [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India); Biswas, Indranil [Materials Characterization and Instrumentation Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India); Jana, Sunirmal, E-mail: sjana@cgcri.res.in [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India)

    2016-10-15

    Highlights: • Polyaniline (PANI) hybridized ZnO nanorods was synthesized by solution method. • Surface defects were found in the nanorods. • The hybrid material exhibited an enhancement in visible light absorption. • A long-term stable photoelectrochemical activity of the material was found. • Advancement in the properties would be PANI hybridization and surface defects. - Abstract: We report surfactant/template free precursor solution based synthesis of polyaniline (PANI) hybridized surface defective ZnO nanorods by a two-step process. Initially, ZnO nanorods have been prepared at 95 °C, followed by hybridization (coating) of PANI onto the ZnO via in situ polymerization of aniline monomer, forming ZnO-PANI nanohybrid (ZP). The structural properties of ZP have been analyzed by X-ray diffraction (XRD) and transmission electron microscopic (TEM) studies. The presence of surface defects especially the oxygen vacancies in ZnO has been characterized by photoluminescence emission, high resolution TEM, X-ray photoelectron spectroscopy (XPS) and micro-Raman spectral measurements. The chemical interaction of PANI with ZnO has been examined by Fourier transform infrared (FTIR) and XPS analyses. A significant enhancement in visible absorption of ZP sample is found as evidenced from UV–vis diffused reflectance spectral study. BET nitrogen adsorption-desorption isotherm shows an improved textural property (pore size, pore volume) of ZP. Moreover, a long-term stable photoelectrochemical activity (PEC) of ZP is found compare to pristine ZnO. The synergic effect of PANI hybridization and the presence of surface defects in ZnO NRs can enhance the PEC by prolonging the recombination rate of photogenerated charge carriers. The effect can also provide large number of active sites to make electrolyte diffusion and mass transportation easier in the nanohybrid. This simple synthesis strategy can be adopted for PANI hybridization with different metal oxide semiconductors

  3. Might short term rockglacier surface morphological changes be attributed to permafrost degradation ?

    Science.gov (United States)

    Perrier, Romain; Cossart, Etienne; Fort, Monique

    2015-04-01

    In high mountain environments, permafrost is increasingly affected by climate change. Rockglaciers represent the expression of creeping permafrost: they are generally considered as good geo-indicators of cryosphere distribution and evolution. Research dealing with the effect of climate change on rockglacier degradation is mostly based on photogrammetric studies as well as geophysics. Major results on rockglaciers behavior in relation to increasing mean annual air temperature are summarized as follows. Firstly, photogrammetry analysis shows that rockglacier surface velocities are higher when the permafrost temperature and/or water content increase within the rockglacier system; this can sometimes lead to the destabilization/collapse of rockglaciers. Secondly, geophysical studies demonstrate a decrease in resistivities within the rockglacier body in relation to a decrease in ice content hence suggesting a degradation of permafrost. Although these methods are appropriate for studying the effects of climate change on mountain permafrost and rockglacier evolution, their application is fairly costly and time-consuming, and are usually restricted to one or two study cases. Our investigations over a wider area up to regional scale require completing our approach by using surface morphological changes, a method that can identify potential degradation in a warming context. In this context, this work intends to characterize short terms (multi-decades) surface morphological changes at rockglacier scale and to determine if these changes may be attributed to potential permafrost degradation. Our investigations have been carried out in both Clarée and Ubaye valleys, in the French Southern Alps. Here we present our results obtained from the Lac Rouge rockglacier (45°02'49''N, 6°30'16''E; 2600-2825m a.s.l, Clarée valley, French Southern Alps). Analysis of multi-temporal aerial photographs, geomorphological field mapping, electrical resistivity tomographies and surface

  4. Surface glycoprotein PSA (GP46) expression during short- and long-term culture of Leishmania chagasi.

    Science.gov (United States)

    Beetham, Jeffrey K; Donelson, John E; Dahlin, Rebecca R

    2003-10-01

    The mRNAs encoding promastigote surface antigen (PSA) of Leishmania chagasi have previously been shown to increase about 30-fold as in vitro cultured parasites progress from logarithmic to stationary phase, growth phases that are, respectively associated with parasites having low and high infectivity to mammals. Experiments reported here establish by western blot analysis that PSA proteins of 44 and 66 kDa also increase about 30-fold as parasite cultures reach stationary phase. Serial passage of parasite cultures resulted in a progressive reduction in PSA protein and RNA abundance to levels less than 3% that of cultures newly-initiated with parasites derived from a parasitized rodent. Loss of PSA mRNA abundance in serially passaged cells was not due to reduced PSA gene transcription rates, as determined by nuclear run-on assays. Neither was the loss associated with a marked decrease in PSA mRNA stability. Analysis of PSA RNA stability in the presence of actinomycin D, an inhibitor of transcription elongation, failed to detect a difference in fully processed cytosolic PSA mRNA stability regardless of the number of times a culture was passaged or the growth phase of the culture. Based on the lack of detectable difference in (cytosolic) mature PSA mRNA stability during promastigote development, the data indirectly suggest that the regulated expression of PSA in cells from low-passage cultures and the loss of PSA expression in high-passage cultures may be mediated by nuclear events that occur after transcription of the PSA genes and before arrival of the mature mRNAs in the cytoplasm.

  5. Intracellular trafficking of bio-nanocapsule-liposome complex: Identification of fusogenic activity in the pre-S1 region of hepatitis B virus surface antigen L protein.

    Science.gov (United States)

    Somiya, Masaharu; Sasaki, Yasuo; Matsuzaki, Takashi; Liu, Qiushi; Iijima, Masumi; Yoshimoto, Nobuo; Niimi, Tomoaki; Maturana, Andrés Daniel; Kuroda, Shun'ichi

    2015-08-28

    Bio-nanocapsules (BNCs) are a hollow nanoparticle consisting of about 100-nm liposome (LP) embedding about 110 molecules of hepatitis B virus (HBV) surface antigen (HBsAg) L protein as a transmembrane protein. Owing to the human hepatocyte-recognizing domains on the N-terminal region (pre-S1 region), BNCs have recently been shown to attach and enter into human hepatic cells using the early infection mechanism of HBV. Since BNCs could form a complex with an LP containing various drugs and genes, BNC-LP complexes have been used as a human hepatic cell-specific drug and gene-delivery system in vitro and in vivo. However, the role of BNCs in cell entry and intracellular trafficking of payloads in BNC-LP complexes has not been fully elucidated. In this study, we demonstrate that low pH-dependent fusogenic activity resides in the N-terminal part of pre-S1 region (NPLGFFPDHQLDPAFG), of which the first FF residues are essential for the activity, and which facilitates membrane fusion between LPs in vitro. Moreover, BNC-LP complexes can bind human hepatic cells specifically, enter into the cells via clathrin-mediated endocytosis, and release their payloads mostly into the cytoplasm. Taken together, the BNC portion of BNC-LP complexes can induce membrane fusion between LPs and endosomal membranes under low pH conditions, and thereby facilitate the endosomal escape of payloads. Furthermore, the fusogenic domain of the pre-S1 region of HBsAg L protein may play a pivotal role in the intracellular trafficking of not only BNC-LP complexes but also of HBV. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. [Comparative Study for Anti-Hepatitis B Surface Antigen Titers Based on Two Measurement Methods: Using Monoclonal Antibodies Isolated from Hepatitis B Vaccinated Recipients].

    Science.gov (United States)

    Oone, Kumiko; Kani, Satomi; Oohashi, Minoru; Shinkai, Noboru; Inoue, Takako; Wakimoto, Yukio; Tanaka, Yasuhito

    2015-08-01

    As anti-hepatitis B surface antigen (anti-HBs) titers vary depending on the measurement methods, we compared two different methods to measure anti-HBs titers in sera and HBs monoclonal antibodies. The sera from 182 HB virus-resolved patients who were negative for HBsAg but positive for antiHB core protein (HBc) and/or anti-HBs were obtained. The measurement of anti-HBs was compared using either Lumipulse G1200 or Architect i2000SR. Six different monoclonal antibody (mAbs) clones isolated from healthy individuals inoculated with hepatitis B vaccine Bimmugen (genotype C) were used. A statistically significant correlation in anti-HBs titers was found between the two methods tested (Y = 0.951X + 100.7, R = 0.813, p Lumipulse and 12 (6.6%) were opposite results. Measuring 2 mAbs with HBV neutralizing activity, the titers of the 116 antibody (1.0 μg/mL) were comparable (689.3 mIU/mL by Lumipulse and 440.7 mIU/mL by Architect), whereas those of the 478 antibody (1.0 μg/mL) were much lower by Architect than by Lumipulse (42.6 vs. 818.6 mIU/mL, respectively). Of four other mAbs without HBV neutralizing activity, equal titers were observed for one; two mAbs had less anti-HB titers by Architect; and one was below the cut-off index (Lumipulse, and the potential ability to detect the 478 antibody with neutralizing activity is low, indicating that Architect might underestimate anti-HBs titers. Future studies should standardize the anti-HBs titer measurement system.

  7. Development and evaluation of an in-house ELISA to detect hepatitis B virus surface antigen in resource-limited settings.

    Science.gov (United States)

    Fatema, K; Tabassum, S; Nessa, A; Jahan, M

    2013-08-01

    Hepatitis B virus (HBV) infection is of global public health concern. Among various serological tests used for the diagnosis and screening of HBV infection, the enzyme-linked immunosorbent assay (ELISA) to detect hepatitis B surface antigen (HbsAg) is most widely used. The present study was designed to develop and standardize a cost effective in-house ELISA for the detection of HbsAg and compare its performance with two established commercial kits. The concentrations of coating antibody, conjugates and sera were fixed by checkerboard titration. Using known HBsAg positive and negative sera, four different concentrations (1, 0.5, 0.25 and 0.125 microg/well) of coating anti-HBs were applied. Similarly, serial dilutions of patients' sera (1 in 2, 1 in 3, 1 in 5 and 1 in 9) and conjugates (1 in 2, 1 in 3, 1 in 5, 1 in 9 and 1 in 17) were evaluated by checkerboard titration. The optimal concentration of coating antibody was determined at 0.25 microg/well and 1 in 9 dilution for both conjugates and sera. The performance comparison of our in-house ELISA showed excellent correlation with two commercial kits (Pearson 0.957, P = 0.001 for monoclonal antibody coated kit and Pearson 0.929, P = 0.000 for polyclonal antibody coated kit) when OD values were compared. All commercial kit proven positive samples was positive while all negative samples were negative with the in-house ELISA resulting in 100% sensitivity and specificity. The results of our study demonstrated that our in-house ELISA for detection of HBsAg was equally as sensitive and specific as two well-known commercial kits. Thus, this system may be a useful tool for diagnostic and screening purposes, as well as outbreak investigations.

  8. Luteolin-7-O-Glucoside Present in Lettuce Extracts Inhibits Hepatitis B Surface Antigen Production and Viral Replication by Human Hepatoma Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Xiao-Xian Cui

    2017-12-01

    Full Text Available Hepatitis B virus (HBV infection is endemic in Asia and chronic hepatitis B (CHB is a major public health issue worldwide. Current treatment strategies for CHB are not satisfactory as they induce a low rate of hepatitis B surface antigen (HBsAg loss. Extracts were prepared from lettuce hydroponically cultivated in solutions containing glycine or nitrate as nitrogen sources. The lettuce extracts exerted potent anti-HBV effects in HepG2 cell lines in vitro, including significant HBsAg inhibition, HBV replication and transcription inhibition, without exerting cytotoxic effects. When used in combination interferon-alpha 2b (IFNα-2b or lamivudine (3TC, the lettuce extracts synergistically inhibited HBsAg expression and HBV replication. By using differential metabolomics analysis, Luteolin-7-O-glucoside was identified and confirmed as a functional component of the lettuce extracts and exhibited similar anti-HBV activity as the lettuce extracts in vitro. The inhibition rate on HBsAg was up to 77.4%. Moreover, both the lettuce extracts and luteolin-7-O-glucoside functioned as organic antioxidants and, significantly attenuated HBV-induced intracellular reactive oxygen species (ROS accumulation. Luteolin-7-O-glucoside also normalized ROS-induced mitochondrial membrane potential damage, which suggests luteolin-7-O-glucoside inhibits HBsAg and HBV replication via a mechanism involving the mitochondria. Our findings suggest luteolin-7-O-glucoside may have potential value for clinical application in CHB and may enhance HBsAg and HBV clearance when used as a combination therapy.

  9. Impact of "a" determinant mutations on detection of hepatitis B surface antigen (HBsAg) in HBV strains from Chinese patients with occult hepatitis B.

    Science.gov (United States)

    Huang, Xiangyan; Ma, Chenyun; Zhang, Qiang; Shi, Qingfen; Huang, Tao; Liu, Chao; Li, Jie; Hollinger, F Blaine

    2017-10-01

    This study was designed to detect mutations that occur within the "a" determinant in the S gene of the hepatitis B virus (HBV) in patients with occult hepatitis B (OHB), and to analyze the influence of these mutations on expression and reactivity of the hepatitis B surface antigen (HBsAg). Twenty-three certified OHB samples were compared to 32 HBsAg positive samples from patients with chronic hepatitis B. The median HBV DNA levels in the OHB group were significantly lower than those in the control group (P determinant were analyzed by gene amplification and sequencing. This revealed mixed infections in which clones within a sample displayed either different mutations or mutations in association with clones that exhibited wild type amino acid patterns. Sequencing analysis also showed a significant difference between the proportions of amino acid mutations observed in the OHB and control groups. Seven recombinant S (rS) proteins with corresponding OHB mutations and three wild type alleles were expressed and purified in the Pichia pastoris expression system to preserve conformational attributes, and their reactivity analyzed using six commercial HBsAg assays. The OHB sera were HBsAg nonreactive while the rS proteins with corresponding OHB mutations were universally reactive. Thus, we postulate that the reduced binding affinity between mutated HBsAg and its antibody may not be as important in defining OHB as is the effect of specific mutations in the preS/S region of the genome that affect the synthesis and secretion of the S protein and/or the virion. © 2017 Wiley Periodicals, Inc.

  10. Prognostic implications of recipient or donor hepatitis B seropositivity in thoracic transplantation: analysis of 426 hepatitis B surface antigen-positive recipients.

    Science.gov (United States)

    Manickam, P; Krishnamoorthi, R; Kanaan, Z; Gunasekaran, P K; Cappell, M S

    2014-08-01

    Prognostic data on survival of hepatitis B surface antigen-positive (HBsAg+) recipients and of hepatitis B core antibody-positive (HBcAb+) donors are limited in the thoracic transplantation (TT) cohort. Improved understanding of risks could potentially expand the recipient and donor pools. Post-hoc analysis of limited-access dataset of the United Network for Organ Sharing database from January 2000-September 2010 was performed. Analyses were performed for all TT, including single and bilateral lung, orthotopic heart, and simultaneous heart-lung transplants. The primary analyzed outcome was overall survival. A Cox proportional multivariate hazards model was used to adjust for significant risk predictors. Of 24,817 patients included, 426 recipients were HBsAg+, of whom 106 (25%) died during a mean follow-up of 3.6 years. On multivariate analysis, recipient HBsAg+ (hazard ratio [HR] = 0.88, 95% confidence interval [CI]: 0.69-1.32; P = 0.80), and donor HBcAb+ (HR = 0.91, 95% CI: 0.68-1.22; P = 0.53) were not associated with increased overall mortality in the entire TT cohort, with similar results for each individual transplant cohort. Unadjusted survival analysis using Kaplan-Meier curves in individual transplant cohorts did not show significant differences between HBsAg+ and HBsAg- recipients. No statistically significant differences were found between causes of mortality in the 2 groups. HBsAg+ status of recipients or HBcAb+ status of donors does not significantly affect overall survival of TT recipients. These data add to the scant literature on this subject and could potentially increase the donor and recipient pools. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Seroclearance of hepatitis B surface antigen following hepatitis E exacerbation on chronic hepatitis E and B dual infection in a renal transplant recipient: a case report.

    Science.gov (United States)

    Yeh, Chau-Ting; Yeh, Christopher Sung-Huan; Chu, Yu-De; Chiang, Yang-Jen

    2018-02-28

    Hepatitis E virus infection usually causes an acute and self-resolving hepatitis. In areas where chronic hepatitis B virus infection is prevalent, acute hepatitis E virus superinfection on chronic hepatitis B virus infection occurs sporadically. In recent years, however, chronic hepatitis E virus infection has been recognized in patients under immunosuppressant therapy. To the best of our knowledge, cases involving patients with chronic hepatitis E virus and hepatitis B virus dual infection have never been reported. A 47-year-old Taiwanese woman who was a renal transplant recipient with chronic hepatitis B virus infection was under immunosuppressant and antiviral treatment. An episode of hepatitis B exacerbation developed due to withdrawal of antiviral treatment against advice, but the flare subsided following antiviral re-treatments. However, an episode of hepatitis exacerbation developed following removal of the renal graft because of graft failure. During the hepatitis flare, she was still under successful antiviral suppression against hepatitis B virus, while her serum samples were positive for hepatitis E virus RNA. Following the hepatitis flare, seroclearance of hepatitis B virus surface antigen developed. From then on, she was under regular hemodialysis. Five years later, another episode of mild hepatitis exacerbation occurred again with positive serum hepatitis E virus RNA. Tracing back the longitudinal serum samples, serum hepatitis E virus RNA was persistently positive throughout the course. This patient was thus recognized to have chronic hepatitis E virus and hepatitis B virus dual infection with intermittent hepatitis E exacerbations. In areas where chronic hepatitis B virus infection is prevalent, chronic hepatitis E virus coinfection can occur in organ transplant recipients receiving immunosuppressant. Intermittent hepatitis E exacerbations may develop, interfering with the status of hepatitis B virus infection.

  12. Results from tandem Phase 1 studies evaluating the safety, reactogenicity and immunogenicity of the vaccine candidate antigen Plasmodium falciparum FVO merozoite surface protein-1 (MSP142 administered intramuscularly with adjuvant system AS01

    Directory of Open Access Journals (Sweden)

    Otsyula Nekoye

    2013-01-01

    Full Text Available Abstract Background The development of an asexual blood stage vaccine against Plasmodium falciparum malaria based on the major merozoite surface protein-1 (MSP1 antigen is founded on the protective efficacy observed in preclinical studies and induction of invasion and growth inhibitory antibody responses. The 42 kDa C-terminus of MSP1 has been developed as the recombinant protein vaccine antigen, and the 3D7 allotype, formulated with the Adjuvant System AS02A, has been evaluated extensively in human clinical trials. In preclinical rabbit studies, the FVO allele of MSP142 has been shown to have improved immunogenicity over the 3D7 allele, in terms of antibody titres as well as growth inhibitory activity of antibodies against both the heterologous 3D7 and homologous FVO parasites. Methods Two Phase 1 clinical studies were conducted to examine the safety, reactogenicity and immunogenicity of the FVO allele of MSP142 in the adjuvant system AS01 administered intramuscularly at 0-, 1-, and 2-months: one in the USA and, after evaluation of safety data results, one in Western Kenya. The US study was an open-label, dose escalation study of 10 and 50 μg doses of MSP142 in 26 adults, while the Kenya study, evaluating 30 volunteers, was a double-blind, randomized study of only the 50 μg dose with a rabies vaccine comparator. Results In these studies it was demonstrated that this vaccine formulation has an acceptable safety profile and is immunogenic in malaria-naïve and malaria-experienced populations. High titres of anti-MSP1 antibodies were induced in both study populations, although there was a limited number of volunteers whose serum demonstrated significant inhibition of blood-stage parasites as measured by growth inhibition assay. In the US volunteers, the antibodies generated exhibited better cross-reactivity to heterologous MSP1 alleles than a MSP1-based vaccine (3D7 allele previously tested at both study sites. Conclusions Given that the primary

  13. Micro patterned surfaces: an effective tool for long term digital holographic microscopy cell imaging

    Science.gov (United States)

    Mues, Sarah; Lilge, Inga; Schönherr, Holger; Kemper, Björn; Schnekenburger, Jürgen

    2017-02-01

    The major problem of Digital Holographic Microscopy (DHM) long term live cell imaging is that over time most of the tracked cells move out of the image area and other ones move in. Therefore, most of the cells are lost for the evaluation of individual cellular processes. Here, we present an effective solution for this crucial problem of long-term microscopic live cell analysis. We have generated functionalized slides containing areas of 250 μm per 200 μm. These micropatterned biointerfaces consist of passivating polyaclrylamide brushes (PAAm). Inner areas are backfilled with octadecanthiol (ODT), which allows cell attachment. The fouling properties of these surfaces are highly controllable and therefore the defined areas designed for the size our microscopic image areas were effective in keeping all cells inside the rectangles over the selected imaging period.

  14. Long-term sea surface temperature baselines - time series, spatial covariation and implications for biological processes

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Schiedek, D.

    2007-01-01

    at coastal sites co-varied strongly with each other and with opportunistically measured offshore temperatures despite separation distances between measuring locations of 20-1200 km. This covariance is probably due to the influence of large-scale atmospheric processes on regional temperatures...... questions at large spatial scales, such as the response of species distributions and phenologies to climate change. In this study we investigate the spatial synchrony of long-term sea surface temperatures in the North Sea-Baltic Sea region as measured daily at four coastal sites (Marsdiep, Netherlands...

  15. Development of anti-hepatitis B surface (HBs) antibodies after HBs antigen loss in HIV-hepatitis B virus co-infected patients.

    Science.gov (United States)

    Boyd, Anders; Canini, Laetitia; Gozlan, Joël; Lascoux-Combe, Caroline; Miailhes, Patrick; Fonquernie, Laurent; Girard, Pierre-Marie; Lacombe, Karine

    2017-10-01

    Hepatitis B surface antigen (HBsAg)-seroconversion, or loss of HBsAg and acquisition of anti-hepatitis B surface (HBs) antibodies, defines functional cure of chronic hepatitis B virus (HBV) infection. After HBsAg-loss, little is known regarding the development of anti-HBs antibodies and even less so in individuals co-infected with HIV. To determine anti-HBs antibody kinetics after HBsAg-loss and explore determinants of HBsAg-seroconversion in HIV-HBV co-infected patients. Patients enrolled in the French HIV-HBV cohort were included if they had >1 study visit after HBsAg-loss. Individual patient kinetics of anti-HBs antibody levels were modeled over time using mixed-effect non-linear regression, whereby maximum specific growth rate and maximal level of antibody production were estimated from a Gompertz growth equation. Fourteen (4.6%) of 308 co-infected patients followed in the cohort exhibited HBsAg-loss, all of whom were undergoing antiretroviral therapy. Nine (64.3%) of these patients achieved HBsAg-seroconversion during a median 3.0 years (IQR=1.1-5.1) after HBsAg-loss. Across individuals with HBsAg-seroconversion, the fastest rates of antibody growth ranged between 0.57-1.93year -1 (population maximum growth rate=1.02) and antibody production plateaued between 2.09-3.66 log 10 mIU/mL at the end of follow-up (population maximal antibody levels=2.66). Patients with HBsAg-seroconversion had substantial decreases in HBV DNA viral loads (P=0.03) and proportion with elevated ALT levels (P=0.02) and HBeAg-positive serology (P=0.08). No such differences were observed in those without HBsAg-seroconversion. Most co-infected patients with HBsAg-seroconversion produced and maintained stable antibody levels, yet kinetics of anti-HBs production were much slower compared to those observed post-vaccination or after clearance of acute HBV-infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Surface ozone in China: present-day distribution and long-term changes

    Science.gov (United States)

    Xu, X.; Lin, W.; Xu, W.

    2017-12-01

    Reliable knowledge of spatio-temporal variations of surface ozone is highly needed to assess the impacts of ozone on human health, ecosystem and climate. Although regional distributions and trends of surface ozone in European and North American countries have been well characterized, little is known about the variability of surface ozone in many other countries, including China, where emissions of ozone precursors have been changing rapidly in recent decades. Here we present the first comprehensive description of present-day (2013-2017) distribution and long-term changes of surface ozone in mainland China. Recent ozone measurements from China's air quality monitoring network (AQMN) are analyzed to show present-day distributions of a few ozone exposure metrics for urban environment. Long-term measurements of ozone at six background sites, a rural site and an urban are used to study the trends of ozone in background, rural and urban air, respectively. The average levels of ozone at the AQMN sites (mainly urban) are close to those found at many European and North American sites. However, ozone at most of the sites shows very large diurnal and seasonal variations so that ozone nonattainment can occur in many cities, particularly those in the North China Plain (NCP), the south of Northeast China (NEC), the Yangtze River Delta (YRD), the Pearl River Delta (PRD), and the Sichuan Basin-Chongqing region (SCB). In all these regions, particularly in the NCP, the maximum daily 8-h average (MDA8) ozone concentration can significantly exceed the national limit (75 ppb). High annual sum of ozone means over 35 ppb (SOMO35) exist mainly in the NCP, NEC and YRD, with regional averages over 4000 ppb·d. Surface ozone has significantly increased at Waliguan (a baseline site in western China) and Shangdianzi (a background site in the NCP), and decreased in winter and spring at Longfengshan (a background site in Northeast China). No clear trend can be derived from long-term measurements

  17. A model of short term surface deformation of Soufriere Hills Volcano, Montserrat, constrained by GPS geodesy

    Science.gov (United States)

    McPherson, E. E.; Mattioli, G. S.

    2013-05-01

    Soufriere Hills Volcano (SHV), Montserrat, in the Lesser Antilles island arc, became active in 1995, and for nearly two decades, ground breaking geodetic surveys have been conducted using both continuous GPS and campaign GPS sites. Data have been collected and processed using the latest and most advanced geodetic instruments and technique available. The NSF- funded CALIPSO and SEA-CALIPSO projects have allowed for some of the most in depth studies of the ongoing SHV eruptions to date, and many models for surface deformation and magmatic chamber configuration have resulted. Research for this study is constrained to data gathered from the early stages of eruption in 1996 through 2010 from two continuous GPS sites, Hermitage Peak (HERM - located ~1.6 km from the vent) and Montserrat Volcano Observatory 1 (MVO1- located ~7.6 km away from the vent) and have been reprocessed using GIPSY-OASIS II (v. 6.1.2) with final, precise IGS08 orbits, clocks, and earth orientation parameters using an absolute point positioning (APP) strategy. Our study is being conducted to re-examine spatial and temporal changes in surface deformation, constrained by GPS, and to better illuminate the short term (i.e. sub-daily to weekly) deformation signals noted amongst the longer, cyclic deformation signals (i.e. monthly to annually) that have been previously reported and modeled. The reprocessed time-series show lower variance for daily APP solutions over the entire temporal data set; trends in the long-term inflation and deflation patterns are similar to those previously published (e.g. Elsworth et al., 2008; Mattioli et al., 2010; Odbert et al., 2012), but now superimposed, shorter term signals are more clearly visible. New elastic deformation models are being developed and will be presented for these short-term signals.

  18. Carcinoma-associated antigens

    International Nuclear Information System (INIS)

    Bartorelli, A.; Accinni, R.

    1981-01-01

    This invention relates to novel antigens associated with breast carcinoma, anti-sera specific to said antigens, 125 I-labeled forms of said antigens and methods of detecting said antigens in serum or plasma. The invention also relates to a diagnostic kit containing standardised antigens or antisera or marked forms thereof for the detection of said antigens in human blood, serum or plasma. (author)

  19. Dynamic interaction of /sup 111/indium-labeled monoclonal antibodies with surface antigens of solid tumors visualized in vivo by external scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, K.M.; Keenan, A.M.; Frincke, J.; David, G.; Pearson, J.; Oldham, R.K.; Morgan, A.C. Jr.

    1986-05-01

    Two /sup 111/indium-labeled murine monoclonal antibodies (MoAb), D3 and 9.2.27, directed to tumor antigens of L-10 hepatocarcinoma and human melanoma, respectively, selectively localized antigen-positive target cells in guinea pigs and nude mice. The fate of MoAb differed in the two antigen-antibody systems after reacting with their corresponding tumor antigens in vivo as reflected by patterns of distribution and turnover in vivo. The 9.2.27 localized in melanoma xenograft in nude mice after intravenous administration with slow loss from tumor but more rapid loss from normal tissues and thus demonstrated optimal imaging of small tumors (approximately equal to 5 mm) between 3 and 6 days after injection of the radiolabeled antibody. In contrast, D3 demonstrated a biphasic localization in guinea pig L-10 hepatocarcinoma with a maximal activity on the 2d day after administration and showed rapid loss from both tumor and normal tissues. Nonspecific localization of antibodies in liver and in kidney was found both in syngeneic (nude mice) and xenogeneic (guinea pig) hosts but was more pronounced in the xenogeneic species. These results indicate that the nature of the antigen-antibody interaction may be of importance in selecting MoAb for both diagnosis and therapy of malignant diseases.

  20. The long-term Global LAnd Surface Satellite (GLASS) product suite and applications

    Science.gov (United States)

    Liang, S.

    2015-12-01

    Our Earth's environment is experiencing rapid changes due to natural variability and human activities. To monitor, understand and predict environment changes to meet the economic, social and environmental needs, use of long-term high-quality satellite data products is critical. The Global LAnd Surface Satellite (GLASS) product suite, generated at Beijing Normal University, currently includes 12 products, including leaf area index (LAI), broadband shortwave albedo, broadband longwave emissivity, downwelling shortwave radiation and photosynthetically active radiation, land surface skin temperature, longwave net radiation, daytime all-wave net radiation, fraction of absorbed photosynetically active radiation absorbed by green vegetation (FAPAR), fraction of green vegetation coverage, gross primary productivity (GPP), and evapotranspiration (ET). Most products span from 1981-2014. The algorithms for producing these products have been published in the top remote sensing related journals and books. More and more applications have being reported in the scientific literature. The GLASS products are freely available at the Center for Global Change Data Processing and Analysis of Beijing Normal University (http://www.bnu-datacenter.com/), and the University of Maryland Global Land Cover Facility (http://glcf.umd.edu). After briefly introducing the basic characteristics of GLASS products, we will present some applications on the long-term environmental changes detected from GLASS products at both global and local scales. Detailed analysis of regional hotspots, such as Greenland, Tibetan plateau, and northern China, will be emphasized, where environmental changes have been mainly associated with climate warming, drought, land-atmosphere interactions, and human activities.

  1. Characterization of sporozoite surface antigens of Plasmodium falciparum, using monoclonal antibodies. Part of a coordinated programme on the preparation of irradiated vaccines against some human diseases

    International Nuclear Information System (INIS)

    Groot, M.

    1982-10-01

    Sporozoites are considered as a source of potential vaccine. Characterization of their antigens is therefore important and can be achieved by monoclonal antibodies. The purpose of this project is to study the production of monoclonal antibodies against sporozoites of P. falciparum. Various infections of mosquitoes were carried out during the period 1981-1982 to obtain antigens for the production of hybridomas. Hybridomas were produced from mice immunized through the bites of infected mosquitoes and by intravenous inoculation. The anti-sporozoite activity of the hybridomas was tested by an immunofluorescent antibody test using P. falciparum sporozoites as antigens. Positive immunofluorescence was seen in hybridoma cell lines tested with P. falciparum, whereas negative results were obtained when the cell lines were cross-reacted with other human species (P. vivax) and with a rodent malaria parasite (P. berghei)

  2. Long-term surface EMG monitoring using K-means clustering and compressive sensing

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    In this work, we present an advanced K-means clustering algorithm based on Compressed Sensing theory (CS) in combination with the K-Singular Value Decomposition (K-SVD) method for Clustering of long-term recording of surface Electromyography (sEMG) signals. The long-term monitoring of sEMG signals aims at recording of the electrical activity produced by muscles which are very useful procedure for treatment and diagnostic purposes as well as for detection of various pathologies. The proposed algorithm is examined for three scenarios of sEMG signals including healthy person (sEMG-Healthy), a patient with myopathy (sEMG-Myopathy), and a patient with neuropathy (sEMG-Neuropathr), respectively. The proposed algorithm can easily scan large sEMG datasets of long-term sEMG recording. We test the proposed algorithm with Principal Component Analysis (PCA) and Linear Correlation Coefficient (LCC) dimensionality reduction methods. Then, the output of the proposed algorithm is fed to K-Nearest Neighbours (K-NN) and Probabilistic Neural Network (PNN) classifiers in order to calclute the clustering performance. The proposed algorithm achieves a classification accuracy of 99.22%. This ability allows reducing 17% of Average Classification Error (ACE), 9% of Training Error (TE), and 18% of Root Mean Square Error (RMSE). The proposed algorithm also reduces 14% clustering energy consumption compared to the existing K-Means clustering algorithm.

  3. Inhibition of Viability, Proliferation, Cytokines Secretion, Surface Antigen Expression, and Adipogenic and Osteogenic Differentiation of Adipose-Derived Stem Cells by Seven-Day Exposure to 0.5 T Static Magnetic Fields

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-01-01

    Full Text Available After seven-day exposure to 0.5-Tesla Static Magnetic Field (SMF, Adipose-derived Stem Cells (ASCs and those labeled by superparamagnetic iron oxide (SPIO nanoparticles were examined for viability by methyl thiazol tetrazolium (MTT assay, proliferation by cell counting and bromodeoxyuridine (BrdU incorporation, DNA integrity by single cell gel electrophoresis, surface antigen by flow cytometry analysis, and the expression of cytokines and genetic markers by reverse transcription-PCR and underwent adipogenic and osteogenic differentiation assessed by quantifying related specific genes expression. The SMF slightly reduced cell viability and proliferation and inhibited the expression of CD49d, CD54, and CD73 but did not damage DNA integrity. The SMF slightly downregulated the expression of cytokines including Vascular Endothelial Growth Factor (VEGF, Insulin-like Growth Factor-1 (IGF-1, Transforming Growth Factor Beta 1 (TGF-β1, genetic markers comprising Stem Cell Antigen-1 (Sca1, Octamer-4 (Oct-4, ATP-binding Cassette Subfamily B Member 1 (ABCB1, adipogenic marker genes containing Lipoprotein Lipase (LPL, Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ, and osteogenic marker genes including Secreted Phosphor-protein 1 (SPP1 and Osterix (OSX. Exposure to 0.5 T SMF for seven days inhibited viability, proliferation, surface antigen expression, cytokine secretion, stem cell genetic marker expression, and adipogenic and osteogenic differentiation but did not affect the DNA integrity in ASCs with or without SPIO labeling.

  4. Dysregulated Response of Follicular Helper T cells to Hepatitis B Surface Antigen Promotes HBV Persistence in Mice and Associates With Outcomes of Patients.

    Science.gov (United States)

    Wang, Xiaowen; Dong, Qingyang; Li, Qian; Li, Yuanyuan; Zhao, Dianyuan; Sun, Jinjie; Fu, Junliang; Meng, Fanping; Lin, Hu; Luan, Junjie; Liu, Biao; Wang, Min; Wang, Fusheng; He, Fuchu; Tang, Li

    2018-03-12

    Production of neutralizing antibodies against hepatitis B surface antigen (HBsAg) is dysregulated in patients with persistent hepatitis V virus (HBV) infection. We investigated mechanisms by which this immune response to the virus is disrupted and whether it can be restored to promote clearance of HBV. Immune-competent C57BL/6N and C57BL/6J, as well as mice deficient in follicular helper T cells (Tfh cell-deficient), B cells, or Foxp3 + T-regulatory cells (Treg cell-deficient), were given hydrodynamic injections of pAAV/HBV1.2 plasmids. Some mice were given injections of sorted Tfh cells, pan-B cells, Treg cells, or a blocking antibody against CTLA4. Production of antibodies against HBsAg and clearance of HBV were assessed by flow cytometry, ELISA, PCR and immunohistochemical analyses. We obtained blood samples from patients with HBV infection and isolated Treg cells. We measured the ability of Treg cells to suppress production of interleukin 21 (IL21) in CD4 + T cells. Immune-competent C57BL/6N and C57BL/6J mice transfected with the plasmid encoding HBV had features of viral clearance and viral persistence observed in humans. A Tfh-cell response to HBsAg was required for clearance of HBV and was suppressed by Treg cells in mice with persistent HBV infection. Depletion of Treg cells or inhibition of Treg-cell function (with blocking antibody against CTLA4) restored the Tfh-cell response against HBsAg and clearance of HBV in mice. Impaired Tfh cell response to HBsAg was observed in blood from patients with chronic HBV infection, responsiveness was restored by depletion of Treg cells or blocking antibody against CTLA4. In studies of HBV-infected mice and blood from patients with chronic HBV infection, we found a Tfh-cell response to HBsAg of to be required for HBV clearance, and that this response was blocked by Treg cells. Inhibiting Treg cell activity using neutralizing antibody against CTLA4 restored the ability of Tfh cells to clear HBV infection; this approach

  5. Understanding early serum hepatitis D virus and hepatitis B surface antigen kinetics during pegylated interferon-alpha therapy via mathematical modeling.

    Science.gov (United States)

    Guedj, Jeremie; Rotman, Yaron; Cotler, Scott J; Koh, Christopher; Schmid, Peter; Albrecht, Jeff; Haynes-Williams, Vanessa; Liang, T Jake; Hoofnagle, Jay H; Heller, Theo; Dahari, Harel

    2014-12-01

    There is little information on the early kinetics of hepatitis delta virus (HDV) and hepatitis B surface antigen (HBsAg) during interferon-α therapy. Here a mathematical model was developed and fitted to frequent HDV and HBsAg kinetic data from 10 patients during the first 28 weeks of pegylated-interferon-α2a (peg-IFN) therapy. Three patients achieved a complete virological response (CVR), defined as undetectable HDV 6 months after treatment stopped with loss of HBsAg and anti-HBsAg seroconversion. After initiation of therapy, a median delay of 9 days (interquartile range [IQR]: 5-15) was observed with no significant changes in HDV level. Thereafter, HDV declined in a biphasic manner, where a rapid first phase lasting for 25 days (IQR: 23-58) was followed by a slower or plateau second phase. The model predicts that the main effect of peg-IFN is to reduce HDV production/release with a median effectiveness of 96% (IQR: 93-99.8). Median serum HDV half-life (t1/2 ) was estimated as 2.9 days (IQR: 1.5-5.3) corresponding to a pretreatment production and clearance of about 10(10) (IQR: 10(9.7) -10(10.7) ) virions/day. None of the patients with flat second phase in HDV achieved CVR. HBsAg kinetics of decline paralleled the second phase of HDV decline consistent with HBsAg-productive-infected cells being the main source of production of HDV, with a median t1/2 of 135 days (IQR: 20-460). The interferon lambda-3 polymorphism (rs12979860) was not associated with kinetic parameters. Modeling results provide insights into HDV-host dynamics, the relationship between serum HBsAg levels and HBsAg-infected cells, IFN's mode of action, and its effectiveness. The observation that a flat second phase in HDV and HBsAg kinetics was associated with failure to achieve CVR provides the basis to develop early stopping rules during peg-IFN treatment in HDV-infected patients. © 2014 by the American Association for the Study of Liver Diseases. This article has been contributed to by U

  6. Outcomes of liver transplantation in simultaneously hepatitis B surface antigen and hepatitis C virus RNA positive recipients: the deleterious effect of donor hepatitis B core antibody positivity.

    Science.gov (United States)

    Tandoi, F; Romagnoli, R; Martini, S; Mazza, E; Nada, E; Cocchis, D; Lupo, F; Salizzoni, M

    2012-09-01

    Recent data from Italian studies have shown excellent results of liver transplantation (LT) in hepatitis B virus (HBV)-infected patients with grafts from hepatitis B core antibody (HBcAb)-positive donors, whereas such grafts in hepatitis C virus (HCV)-infected recipients have displayed poorer outcomes. We investigated the results of LT with HBcAb-positive grafts in patients with ongoing HBV and HCV coinfections. From August 1999 to December 2009, we performed 27 adult primary LTs from deceased heart-beating donors into recipients showing hepatitis B surface antigen (HBsAg)- and HCV-RNA-positivity simultaneously: 12 patients received a graft from an HBsAg-negative HBcAb-positive donor (core+D group) and 15 from an HBcAb-negative donor (core-D group). Immunosuppression included a calcineurin inhibitor, antimetabolite and steroids which were suspended at 6 months. Anti-HBV prophylaxis was always perfomed with anti-HBs immunoglobulins and nucleos(t)idic analogues. The groups were similar regarding variables of donor, recipient, donor-recipient match, LT procedure, and acute rejection treatment. Median follow-up for surviving grafts was 67 months (range, 16-141). Among all patients, HCV-RNA remained positive after LT. The prevalence of histologically proven recurrent HCV hepatitis was similar in the 2 groups: 83% core+D vs 73% core-D. No recurrent HBV hepatitis occurred during the follow-up. Graft survival at 5 years was significantly lower in the core+D group (core+D 48% vs core-D 87%; P = .018), in which a significantly higher prevalence of graft loss was caused by HCV recurrence (core+D 5/12, 42% vs core-D 1/15, 7%; P = .03). All of the 5 core+D patients who lost their grafts due to HCV recurrence did not receive anti-HCV therapy (4 owing to an aggressive disease and 1 because of patient refusal). Outcomes of LT in patients with ongoing HBV and HCV coinfection are adversely affected by donor HBcAb positivity, an effect that is mainly mediated by the dismal course of

  7. Long-term changes of South China Sea surface temperatures in winter and summer

    Science.gov (United States)

    Park, Young-Gyu; Choi, Ara

    2017-07-01

    Utilizing available atmospheric and oceanographic reanalysis data sets, the long-term trend in South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 and the governing processes are investigated. Both winter and summer SST increased by comparable amounts, but the warming patterns and the governing processes were different. Strong warming in winter occurred in a deep central area, and during summer in the southern region. In winter the net heat flux into the sea increased, contributing to the warming. The spatial pattern of the heat flux, however, was different from that of the warming. Heat flux increased over the coastal area where warming was weaker, but decreased over the deeper area where warming was stronger. The northeasterly monsoon wind weakened lowering the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre which transports cold northern water to the south weakened, thereby warming the ocean. The effect was manifested more strongly along the southward western boundary current inducing warming in the deep central part. In summer however, the net surface heat flux decreased and could not contribute to the warming. Over the southern part of the SCS, the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is parallel to the mean SST gradient. Southeastward cold advection due to Ekman transport was reduced, thereby warming the surface near the southeastern boundary of the SCS. Upwelling southeast of Vietnam was also weakened, raising the SST east of Vietnam contributing to the southern summer warming secondarily. The weakening of the winds in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different in winter and summer.

  8. Protein antigen delivery by gene gun-mediated epidermal antigen incorporation (EAI).

    Science.gov (United States)

    Scheiblhofer, Sandra; Ritter, Uwe; Thalhamer, Josef; Weiss, Richard

    2013-01-01

    The gene gun technology can not only be employed for efficient transfer of gene vaccines into upper layers of the skin, but also for application of protein antigens. As a tissue rich in professional antigen presenting cells, the skin represents an attractive target for immunizations. In this chapter we present a method for delivery of the model antigen ovalbumin into the skin of mice termed epidermal antigen incorporation and describe in detail how antigen-specific proliferation in draining lymph nodes can be followed by flow cytometry.

  9. Long-term change in the source contribution to surface ozone over Japan

    Science.gov (United States)

    Nagashima, Tatsuya; Sudo, Kengo; Akimoto, Hajime; Kurokawa, Junichi; Ohara, Toshimasa

    2017-07-01

    The relative contributions of various source regions to the long-term (1980-2005) increasing trend in surface ozone (O3) over Japan were estimated by a series of tracer-tagging simulations using a global chemical transport model. The model simulated the observed increasing trend in surface O3, including its seasonal variation and geographical features, in Japan well and demonstrated the relative roles of different source regions in forming this trend. Most of the increasing trend in surface O3 over Japan ( ˜ 97 %) that was simulated was explained as the sum of trends in contributions of different regions to photochemical O3 production. The increasing trend in O3 produced in China accounted for 36 % of the total increasing trend and those in the other northeast Asian regions (the Korean Peninsula, coastal regions in East Asia, and Japan) each accounted for about 12-15 %. Furthermore, the contributions of O3 created in the entire free troposphere and in western, southern, and southeastern Asian regions also increased, and their increasing trends accounted for 16 and 7 % of the total trend, respectively. The impact of interannual variations in climate, in methane concentration, and in emission of O3 precursors from different source regions on the relative contributions of O3 created in each region estimated above was also investigated. The variation of climate and the increase in methane concentration together caused the increase of photochemical O3 production in several regions, and represented about 19 % of the total increasing trend in surface O3 over Japan. The increase in emission of O3 precursors in China caused an increase of photochemical O3 production not only in China itself but also in the other northeast Asian regions and accounted for about 46 % of the total increase in surface O3 over Japan. Similarly, the relative impact of O3 precursor emission changes in the Korean Peninsula and Japan were estimated as about 16 and 4 % of the total increasing trend

  10. In vitro selection of Plasmodium falciparum 3D7 for expression of variant surface antigens associated with severe malaria in African children

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Nielsen, Morten A; Vestergaard, Lasse S

    2003-01-01

    P. falciparum-infected red blood cells (IRBC) can adhere to endothelial host receptors through parasite-encoded, clonally variant surface antigens (VSA). The VSA-mediated IRBC adhesion and the acquired VSA-specific antibody response have both been linked to IRBC organ tropism and disease severity....... Parasites isolated from young children with severe malaria (SM) tend to express a limited and conserved set of VSA (VSASM) that are both stronger and more commonly recognized by IgG in the plasma of malaria-exposed individuals than VSA (VSAUM) expressed by parasites causing uncomplicated malaria (UM...... identification of VSASM-encoding genes in 3D7, we report here a method of enforcing expression of VSASM-like antigens in this parasite clone by a novel selection method using plasma from semi-immune children with low VSAUM-specific, but high VSASM-specific, IgG reactivity. In addition to the resulting increase...

  11. Long-term surface pCO2 trends from observations and models

    Directory of Open Access Journals (Sweden)

    Jerry F. Tjiputra

    2014-05-01

    Full Text Available We estimate regional long-term surface ocean pCO2 growth rates using all available underway and bottled biogeochemistry data collected over the past four decades. These observed regional trends are compared with those simulated by five state-of-the-art Earth system models over the historical period. Oceanic pCO2 growth rates faster than the atmospheric growth rates indicate decreasing atmospheric CO2 uptake, while ocean pCO2 growth rates slower than the atmospheric growth rates indicate increasing atmospheric CO2 uptake. Aside from the western subpolar North Pacific and the subtropical North Atlantic, our analysis indicates that the current observation-based basin-scale trends may be underestimated, indicating that more observations are needed to determine the trends in these regions. Encouragingly, good agreement between the simulated and observed pCO2 trends is found when the simulated fields are subsampled with the observational coverage. In agreement with observations, we see that the simulated pCO2 trends are primarily associated with the increase in surface dissolved inorganic carbon (DIC associated with atmospheric carbon uptake, and in part by warming of the sea surface. Under the RCP8.5 future scenario, DIC continues to be the dominant driver of pCO2 trends, with little change in the relative contribution of SST. However, the changes in the hydrological cycle play an increasingly important role. For the contemporary (1970–2011 period, the simulated regional pCO2 trends are lower than the atmospheric growth rate over 90% of the ocean. However, by year 2100 more than 40% of the surface ocean area has a higher oceanic pCO2 trend than the atmosphere, implying a reduction in the atmospheric CO2 uptake rate. The fastest pCO2 growth rates are projected for the subpolar North Atlantic, while the high-latitude Southern Ocean and eastern equatorial Pacific have the weakest growth rates, remaining below the atmospheric pCO2 growth rate. Our work

  12. Virosomes for antigen and DNA delivery

    NARCIS (Netherlands)

    Daemen, T; de Mare, A; Bungener, L; de Jonge, J; Huckriede, A; Wilschut, J

    2005-01-01

    Specific targeting and delivery as well as the display of antigens on the surface of professional antigen-presenting cells (APCs) are key issues in the design and development of new-generation vaccines aimed at the induction of both humoral and cell-mediated immunity. Prophylactic vaccination

  13. The quantity and quality of African children's IgG responses to merozoite surface antigens reflect protection against Plasmodium falciparum malaria.

    NARCIS (Netherlands)

    Courtin, D.; Oesterholt, M.J.A.M.; Huismans, H.; Kusi, K.; Milet, J.; Badaut, C.; Gaye, O.; Roeffen, W.F.G.; Remarque, E.J.; Sauerwein, R.W.; Garcia, A.; Luty, A.J.F.

    2009-01-01

    BACKGROUND: Antibodies, particularly cytophilic IgG subclasses, with specificity for asexual blood stage antigens of Plasmodium falciparum, are thought to play an important role in acquired immunity to malaria. Evaluating such responses in longitudinal sero-epidemiological field studies, allied to

  14. Understanding long-term silver release from surface modified porous titanium implants.

    Science.gov (United States)

    Shivaram, Anish; Bose, Susmita; Bandyopadhyay, Amit

    2017-08-01

    Prevention of orthopedic device related infection (ODRI) using antibiotics has met with limited amount of success and is still a big concern during post-surgery. As an alternative, use of silver as an antibiotic treatment to prevent surgical infections is being used due to the well-established antimicrobial properties of silver. However, in most cases silver is used in particulate form with wound dressings or with short-term devices such as catheters but not with load-bearing implants. We hypothesize that strongly adherent silver to load-bearing implants can offer longer term solution to infection in vivo. Keeping that in mind, the focus of this study was to understand the long term release study of silver ions for a period of minimum 6months from silver coated surface modified porous titanium implants. Implants were fabricated using a LENS™ system, a powder based additive manufacturing technique, with at least 25% volume porosity, with and without TiO 2 nanotubes in phosphate buffer saline (pH 7.4) to see if the total release of silver ions is within the toxic limit for human cells. Considering the fact that infection sites may reduce the local pH, silver release was also studied in acetate buffer (pH 5.0) for a period of 4weeks. Along with that, the osseointegrative properties as well as cytotoxicity of porous titanium implants were assessed in vivo for a period of 12weeks using a rat distal femur model. In vivo results indicate that porous titanium implants with silver coating show comparable, if not better, biocompatibility and bonding at the bone-implant interface negating any concerns related to toxicity related to silver to normal cells. The current research is based on our recently patented technology, however focused on understanding longer-term silver release to mitigate infection related problems in load-bearing implants that can even arise several months after the surgery. Prevention of orthopedic device related infection using antibiotics has met

  15. Safety of currently licensed hepatitis B surface antigen vaccines in the United States, Vaccine Adverse Event Reporting System (VAERS), 2005-2015.

    Science.gov (United States)

    Haber, Penina; Moro, Pedro L; Ng, Carmen; Lewis, Paige W; Hibbs, Beth; Schillie, Sarah F; Nelson, Noele P; Li, Rongxia; Stewart, Brock; Cano, Maria V

    2018-01-25

    Currently four recombinant hepatitis B (HepB) vaccines are in use in the United States. HepB vaccines are recommended for infants, children and adults. We assessed adverse events (AEs) following HepB vaccines reported to the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous reporting system. We searched VAERS for reports of AEs following single antigen HepB vaccine and HepB-containing vaccines (either given alone or with other vaccines), from January 2005 - December 2015. We conducted descriptive analyses and performed empirical Bayesian data mining to assess disproportionate reporting. We reviewed serious reports including reports of special interest. VAERS received 20,231 reports following HepB or HepB-containing vaccines: 10,291 (51%) in persons 18 years; for 1485 (7.3%) age was missing. Dizziness and nausea (8.4% each) were the most frequently reported AEs following a single antigen HepB vaccine: fever (23%) and injection site erythema (11%) were most frequent following Hep-containing vaccines. Of the 4444 (22%) reports after single antigen HepB vaccine, 303 (6.8%) were serious, including 45 deaths. Most commonly reported cause of death was Sudden Infant Death Syndrome (197). Most common non-death serious reports following single antigen HepB vaccines among infants aged 18 years. Most common vaccination error following single antigen HepB was incorrect product storage. Review current U.S.-licensed HepB vaccines administered alone or in combination with other vaccines did not reveal new or unexpected safety concerns. Vaccination errors were identified which indicate the need for training and education of providers on HepB vaccine indications and recommendations. Published by Elsevier Ltd.

  16. Modeling and Simulation of Long-Term Performance of Near-Surface Barriers

    International Nuclear Information System (INIS)

    Piet, S. J.; Jacobson, J. J.; Martian, P.; Martineau, R.; Soto, R.

    2003-01-01

    INEEL started a new project on long-term barrier integrity in April 2002 that aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late, prior to system-level failure). This paper describes our computer simulation approach for better understanding the relationships and dynamics between the various components and management decisions in a cap. The simulation is designed to clarify the complex relationships between the various components within the cap system and the various management practices that affect the barrier performance. We have also conceptualized a time-dependent 3-D simulation with rigorous solution to unsaturated flow physics with complex surface boundary conditions

  17. Modeling and Simulation of Long-Term Performance of Near-Surface Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Piet, S. J.; Jacobson, J. J.; Martian, P.; Martineau, R.; Soto, R.

    2003-02-25

    . Thus, the INEEL started a new project on long-term barrier integrity in April 2002 that aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late, prior to system-level failure). This paper describes our computer simulation approach for better understanding the relationships and dynamics between the various components and management decisions in a cap. The simulation is designed to clarify the complex relationships between the various components within the cap system and the various management practices that affect the barrier performance. We have also conceptualized a time-dependent 3-D simulation with rigorous solution to unsaturated flow physics with complex surface boundary conditions.

  18. Modeling and Simulation of Long-Term Performance of Near-Surface Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Piet, Steven James; Jacobson, Jacob Jordan; Soto, Rafael; Martian, Pete; Martineau, Richard Charles

    2003-02-01

    , the INEEL started a new project on long-term barrier integrity in April 2002 that aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late, prior to system-level failure). This paper describes our computer simulation approach for better understanding the relationships and dynamics between the various components and management decisions in a cap. The simulation is designed to clarify the complex relationships between the various components within the cap system and the various management practices that affect the barrier performance. We have also conceptualized a time-dependent 3-D simulation with rigorous solution to unsaturated flow physics with complex surface boundary conditions.

  19. Long-Term Variability of Satellite Lake Surface Water Temperatures in the Great Lakes

    Science.gov (United States)

    Gierach, M. M.; Matsumoto, K.; Holt, B.; McKinney, P. J.; Tokos, K.

    2014-12-01

    The Great Lakes are the largest group of freshwater lakes on Earth that approximately 37 million people depend upon for fresh drinking water, food, flood and drought mitigation, and natural resources that support industry, jobs, shipping and tourism. Recent reports have stated (e.g., the National Climate Assessment) that climate change can impact and exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of certain fish species, increased invasive species and harmful algal blooms, declining beach health, and lengthened commercial navigation season. In this study, we will examine the impact of climate change on the Laurentian Great Lakes through investigation of long-term lake surface water temperatures (LSWT). We will use the ATSR Reprocessing for Climate: Lake Surface Water Temperature & Ice Cover (ARC-Lake) product over the period 1995-2012 to investigate individual and interlake variability. Specifically, we will quantify the seasonal amplitude of LSWTs, the first and last appearances of the 4°C isotherm (i.e., an important identifier of the seasonal evolution of the lakes denoting winter and summer stratification), and interpret these quantities in the context of global interannual climate variability such as ENSO.

  20. Prediction of Sea Surface Temperature Using Long Short-Term Memory

    Science.gov (United States)

    Zhang, Qin; Wang, Hui; Dong, Junyu; Zhong, Guoqiang; Sun, Xin

    2017-10-01

    This letter adopts long short-term memory(LSTM) to predict sea surface temperature(SST), which is the first attempt, to our knowledge, to use recurrent neural network to solve the problem of SST prediction, and to make one week and one month daily prediction. We formulate the SST prediction problem as a time series regression problem. LSTM is a special kind of recurrent neural network, which introduces gate mechanism into vanilla RNN to prevent the vanished or exploding gradient problem. It has strong ability to model the temporal relationship of time series data and can handle the long-term dependency problem well. The proposed network architecture is composed of two kinds of layers: LSTM layer and full-connected dense layer. LSTM layer is utilized to model the time series relationship. Full-connected layer is utilized to map the output of LSTM layer to a final prediction. We explore the optimal setting of this architecture by experiments and report the accuracy of coastal seas of China to confirm the effectiveness of the proposed method. In addition, we also show its online updated characteristics.

  1. Understanding Long-Term Variations in Surface Ozone in United States (U.S. National Parks

    Directory of Open Access Journals (Sweden)

    Deborah McGlynn

    2018-03-01

    Full Text Available Long-term surface ozone observations at 25 National Park Service sites across the United States were analyzed for processes on varying time scales using a time scale decomposition technique, the Ensemble Empirical Mode Decomposition (EEMD. Time scales of interest include the seasonal cycle, large-scale climate oscillations, and long-term (>10 years trends. Emission reductions were found to have a greater impact on sites that are nearest major urban areas. Multidecadal trends in surface ozone were increasing at a rate of 0.07 to 0.37 ppbv year−1 before 2004 and decreasing at a rate of −0.08 to −0.60 ppbv year−1 after 2004 for sites in the East, Southern California, and Northwestern Washington. Sites in the Intermountain West did not experience a reversal of trends from positive to negative until the mid- to late 2000s. The magnitude of the annual amplitude (=annual maximum–minimum decreased at eight sites, two in the West, two in the Intermountain West, and four in the East, by 5–20 ppbv and significantly increased at three sites; one in Alaska, one in the West, and one in the Intermountain West, by 3–4 ppbv. Stronger decreases in the annual amplitude occurred at a greater proportion of sites in the East (4/6 sites than in the West/Intermountain West (4/19 sites. The date of annual maximums and/or minimums has changed at 12 sites, occurring 10–60 days earlier in the year. There appeared to be a link between the timing of the annual maximum and the decrease in the annual amplitude, which was hypothesized to be related to a decrease in ozone titration resulting from NOx emission reductions. Furthermore, it was found that a phase shift of the Pacific Decadal Oscillation (PDO, from positive to negative, in 1998–1999 resulted in increased occurrences of La Niña-like conditions. This shift had the effect of directing more polluted air masses from East Asia to higher latitudes over the North American continent. The change in the

  2. Identification and characterization of new Leishmania promastigote surface antigens, LaPSA-38S and LiPSA-50S, as major immunodominant excreted/secreted components of L. amazonensis and L. infantum.

    Science.gov (United States)

    Bras-Gonçalves, Rachel; Petitdidier, Elodie; Pagniez, Julie; Veyrier, Renaud; Cibrelus, Prisca; Cavaleyra, Mireille; Maquaire, Sarah; Moreaux, Jérôme; Lemesre, Jean-Loup

    2014-06-01

    We have previously demonstrated that sera from dogs vaccinated with excreted/secreted antigens (ESA) of Leishmania infantum promastigotes (LiESAp) mainly recognized an immunodominant antigen of 54 kDa. An anti-LiESAp-specific IgG2 humoral response was observed and associated to Th1-type response in vaccinated dogs. This response was highly correlated with a long-lasting and strong LiESAp-vaccine protection toward L. infantum experimental infection. In addition, it was also shown that dogs from the vaccinated group developed a selective IgG2 response against an immunodominant antigen of 45 kDa of Leishmania amazonensis ESA promastigotes (LaESAp). In order to identify and characterize these immunodominant antigens, a mouse monoclonal antibody (mAb F5) was produced by immunization against LaESAp. It was found to recognize the major antigenic targets of both LaESAp and LiESAp. Analysis with mAb F5 of L. amazonensis amastigote and promastigote cDNA expression libraries enabled the identification of clones encoding proteins with significant structural homology to the promastigote surface antigens named PSA-2/gp-46. Among them, one clone presented a full-length cDNA and encoded a novel L. amazonensis protein of 38.6 kDa calculated molecular mass (LaPSA-38S) sharing an amino acid sequence consistent with that of the PSA polymorphic family and a N-terminal signal peptide, characteristic of a secreted protein. We then screened a L. infantum promastigote DNA cosmid library using a cDNA probe derived from the LaPSA-38S gene and identified a full-length clone of a novel excreted/secreted protein of L. infantum with a calculated molecular mass of 49.2 kDa and named LiPSA-50S. The fact that a significant immunological reactivity was observed against PSA, suggests that these newly identified proteins could have an important immunoregulatory influence on the immune response. This hypothesis is supported by the fact that (i) these proteins were naturally excreted/secreted by viable

  3. Surface coal mine land reclamation using a dry flue gas desulfurization product: Short-term and long-term water responses.

    Science.gov (United States)

    Chen, Liming; Stehouwer, Richard; Tong, Xiaogang; Kost, Dave; Bigham, Jerry M; Dick, Warren A

    2015-09-01

    Abandoned coal-mined lands are a worldwide concern due to their potential negative environmental impacts, including erosion and development of acid mine drainage. A field study investigated the use of a dry flue gas desulfurization product for reclamation of abandoned coal mined land in USA. Treatments included flue gas desulfurization product at a rate of 280 Mg ha(-1) (FGD), FGD at the same rate plus 112 Mg ha(-1) yard waste compost (FGD/C), and conventional reclamation that included 20 cm of re-soil material plus 157 Mg ha(-1) of agricultural limestone (SOIL). A grass-legume sward was planted after treatment applications. Chemical properties of surface runoff and tile water (collected from a depth of 1.2m below the ground surface) were measured over both short-term (1-4 yr) and long-term (14-20 yr) periods following reclamation. The pH of surface runoff water was increased from approximately 3, and then sustained at 7 or higher by all treatments for up to 20 yr, and the pH of tile flow water was also increased and sustained above 5 for 20 yr. Compared with SOIL, concentrations of Ca, S and B in surface runoff and tile flow water were generally increased by the treatments with FGD product in both short- and long-term measurements and concentrations of the trace elements were generally not statistically increased in surface runoff and tile flow water over the 20-yr period. However, concentrations of As, Ba, Cr and Hg were occasionally elevated. These results suggest the use of FGD product for remediating acidic surface coal mined sites can provide effective, long-term reclamation. Copyright © 2015. Published by Elsevier Ltd.

  4. Complexes of Streptavidin-Fused Antigens with Biotinylated Antibodies Targeting Receptors on Dendritic Cell Surface: A Novel Tool for Induction of Specific T-Cell Immune Responses

    Czech Academy of Sciences Publication Activity Database

    Staněk, Ondřej; Linhartová, Irena; Majlessi, L.; Leclerc, C.; Šebo, Peter

    2012-01-01

    Roč. 51, č. 3 (2012), s. 221-232 ISSN 1073-6085 R&D Projects: GA AV ČR KAN200520702; GA ČR GA310/08/0447; GA MŠk 2B06161 Institutional research plan: CEZ:AV0Z50200510 Keywords : Streptavidin * Antigen delivery * Biotinylated antibody Subject RIV: EE - Microbiology, Virology Impact factor: 2.262, year: 2012

  5. Physiological response of Pichia pastoris GS115 to methanol-induced high level production of the Hepatitis B surface antigen: catabolic adaptation, stress responses, and autophagic processes.

    Science.gov (United States)

    Vanz, Ana Leticia; Lünsdorf, Heinrich; Adnan, Ahmad; Nimtz, Manfred; Gurramkonda, Chandrasekhar; Khanna, Navin; Rinas, Ursula

    2012-08-08

    Pichia pastoris is an established eukaryotic host for the production of recombinant proteins. Most often, protein production is under the control of the strong methanol-inducible aox1 promoter. However, detailed information about the physiological alterations in P. pastoris accompanying the shift from growth on glycerol to methanol-induced protein production under industrial relevant conditions is missing. Here, we provide an analysis of the physiological response of P. pastoris GS115 to methanol-induced high-level production of the Hepatitis B virus surface antigen (HBsAg). High product titers and the retention of the protein in the endoplasmic reticulum (ER) are supposedly of major impact on the host physiology. For a more detailed understanding of the cellular response to methanol-induced HBsAg production, the time-dependent changes in the yeast proteome and ultrastructural cell morphology were analyzed during the production process. The shift from growth on glycerol to growth and HBsAg production on methanol was accompanied by a drastic change in the yeast proteome. In particular, enzymes from the methanol dissimilation pathway started to dominate the proteome while enzymes from the methanol assimilation pathway, e.g. the transketolase DAS1, increased only moderately. The majority of methanol was metabolized via the energy generating dissimilatory pathway leading to a corresponding increase in mitochondrial size and numbers. The methanol-metabolism related generation of reactive oxygen species induced a pronounced oxidative stress response (e.g. strong increase of the peroxiredoxin PMP20). Moreover, the accumulation of HBsAg in the ER resulted in the induction of the unfolded protein response (e.g. strong increase of the ER-resident disulfide isomerase, PDI) and the ER associated degradation (ERAD) pathway (e.g. increase of two cytosolic chaperones and members of the AAA ATPase superfamily) indicating that potential degradation of HBsAg could proceed via the

  6. Impact of the thimerosal controversy on hepatitis B vaccine coverage of infants born to women of unknown hepatitis B surface antigen status in Michigan.

    Science.gov (United States)

    Biroscak, Brian J; Fiore, Anthony E; Fasano, Nancy; Fineis, Patrick; Collins, Michael P; Stoltman, Gillian

    2003-06-01

    Hepatitis B vaccine is recommended for all infants, and the series may be started during the delivery admission. For infants who are born either to women who are positive for hepatitis B surface antigen (HBsAg) or to women whose HBsAg status is unknown, vaccination should be started within 12 hours of birth to prevent perinatal and early childhood hepatitis B virus infection. Because of concerns about mercury exposures from vaccines that contain thimerosal, the United States Public Health Service (USPHS) and the American Academy of Pediatrics (AAP) recommended in July 1999 that the first dose of hepatitis B vaccine be deferred until 2-6 months of age but only for infants who are born to HBsAg-negative women. To assess the impact on birth-dose vaccine coverage for infants who are born to women with unknown HBsAg status, we measured coverage before and after July 1999. A sample of Michigan infants who were born to women whose HBsAg status was either unknown or missing were identified by reviewing newborn screening cards for infants who were born during 1) March-April 1999 (before recommendation changes [T1]); 2) July 15-September 15, 1999 (immediately after recommendation changes [T2]); and 3) March-April 2000 (6 months after resumption of pre-1999 practices were recommended [T3]). We verified maternal HBsAg screening and newborn hepatitis B vaccination by reviewing infant and maternal hospital records. Of 1201 infants who were born to women whose HBsAg status was indicated as unknown or missing on the newborn screening card during the 3 time periods, 216 (18%) were born to women whose status was truly unknown at the time of delivery, as determined by medical record review. During T1, 53% of these 216 infants received hepatitis B vaccine before hospital discharge, compared with 7% of infants who were born during T2 and 57% of infants who were born during T3. During T1, 19% of these infants received hepatitis B vaccine within 12 hours of birth compared with 1% of

  7. Physiological response of Pichia pastoris GS115 to methanol-induced high level production of the Hepatitis B surface antigen: catabolic adaptation, stress responses, and autophagic processes

    Science.gov (United States)

    2012-01-01

    Background Pichia pastoris is an established eukaryotic host for the production of recombinant proteins. Most often, protein production is under the control of the strong methanol-inducible aox1 promoter. However, detailed information about the physiological alterations in P. pastoris accompanying the shift from growth on glycerol to methanol-induced protein production under industrial relevant conditions is missing. Here, we provide an analysis of the physiological response of P. pastoris GS115 to methanol-induced high-level production of the Hepatitis B virus surface antigen (HBsAg). High product titers and the retention of the protein in the endoplasmic reticulum (ER) are supposedly of major impact on the host physiology. For a more detailed understanding of the cellular response to methanol-induced HBsAg production, the time-dependent changes in the yeast proteome and ultrastructural cell morphology were analyzed during the production process. Results The shift from growth on glycerol to growth and HBsAg production on methanol was accompanied by a drastic change in the yeast proteome. In particular, enzymes from the methanol dissimilation pathway started to dominate the proteome while enzymes from the methanol assimilation pathway, e.g. the transketolase DAS1, increased only moderately. The majority of methanol was metabolized via the energy generating dissimilatory pathway leading to a corresponding increase in mitochondrial size and numbers. The methanol-metabolism related generation of reactive oxygen species induced a pronounced oxidative stress response (e.g. strong increase of the peroxiredoxin PMP20). Moreover, the accumulation of HBsAg in the ER resulted in the induction of the unfolded protein response (e.g. strong increase of the ER-resident disulfide isomerase, PDI) and the ER associated degradation (ERAD) pathway (e.g. increase of two cytosolic chaperones and members of the AAA ATPase superfamily) indicating that potential degradation of HBsAg could

  8. Cell-surface expression of neuron-glial antigen 2 (NG2) and melanoma cell adhesion molecule (CD146) in heterogeneous cultures of marrow-derived mesenchymal stem cells.

    Science.gov (United States)

    Russell, Katie C; Tucker, H Alan; Bunnell, Bruce A; Andreeff, Michael; Schober, Wendy; Gaynor, Andrew S; Strickler, Karen L; Lin, Shuwen; Lacey, Michelle R; O'Connor, Kim C

    2013-10-01

    Cellular heterogeneity of mesenchymal stem cells (MSCs) impedes their use in regenerative medicine. The objective of this research is to identify potential biomarkers for the enrichment of progenitors from heterogeneous MSC cultures. To this end, the present study examines variation in expression of neuron-glial antigen 2 (NG2) and melanoma cell adhesion molecule (CD146) on the surface of MSCs derived from human bone marrow in response to culture conditions and among cell populations. Multipotent cells isolated from heterogeneous MSC cultures exhibit a greater than three-fold increase in surface expression for NG2 and greater than two-fold increase for CD146 as compared with parental and lineage-committed MSCs. For both antigens, surface expression is downregulated by greater than or equal to six-fold when MSCs become confluent. During serial passage, maximum surface expression of NG2 and CD146 is associated with minimum doubling time. Upregulation of NG2 and CD146 during loss of adipogenic potential at early passage suggests some limits to their utility as potency markers. A potential relationship between proliferation and antigen expression was explored by sorting heterogeneous MSCs into rapidly and slowly dividing groups. Fluorescence-activated cell sorting revealed that rapidly dividing MSCs display lower scatter and 50% higher NG2 surface expression than slowly dividing cells, but CD146 expression is comparable in both groups. Heterogeneous MSCs were sorted based on scatter properties and surface expression of NG2 and CD146 into high (HI) and low (LO) groups. Sc(LO)NG2(HI) and Sc(LO)NG2(HI)CD146(HI) MSCs have the highest proliferative potential of the sorted groups, with colony-forming efficiencies that are 1.5-2.2 times the value for the parental controls. The Sc(LO) gate enriches for rapidly dividing cells. Addition of the NG2(HI) gate increases cell survival to 1.5 times the parental control. Further addition of the CD146(HI) gate does not significantly

  9. Long-Term Variability of Surface Albedo and Its Correlation with Climatic Variables over Antarctica

    Directory of Open Access Journals (Sweden)

    Minji Seo

    2016-11-01

    Full Text Available The cryosphere is an essential part of the earth system for understanding climate change. Components of the cryosphere, such as ice sheets and sea ice, are generally decreasing over time. However, previous studies have indicated differing trends between the Antarctic and the Arctic. The South Pole also shows internal differences in trends. These phenomena indicate the importance of continuous observation of the Polar Regions. Albedo is a main indicator for analyzing Antarctic climate change and is an important variable with regard to the radiation budget because it can provide positive feedback on polar warming and is related to net radiation and atmospheric heating in the mainly snow- and ice-covered Antarctic. Therefore, in this study, we analyzed long-term temporal and spatial variability of albedo and investigated the interrelationships between albedo and climatic variables over Antarctica. We used broadband surface albedo data from the Satellite Application Facility on Climate Monitoring and data for several climatic variables such as temperature and Antarctic oscillation index (AAO during the period of 1983 to 2009. Time series analysis and correlation analysis were performed through linear regression using albedo and climatic variables. The results of this research indicated that albedo shows two trends, west trend and an east trend, over Antarctica. Most of the western side of Antarctica showed a negative trend of albedo (about −0.0007 to −0.0015 year−1, but the other side showed a positive trend (about 0.0006 year−1. In addition, albedo and surface temperature had a negative correlation, but this relationship was weaker in west Antarctica than in east Antarctica. The correlation between albedo and AAO revealed different relationships in the two regions; west Antarctica had a negative correlation and east Antarctica showed a positive correlation. In addition, the correlation between albedo and AAO was weaker in the west. This

  10. Long-term protective effect of surface sealants against erosive wear by intrinsic and extrinsic acids.

    Science.gov (United States)

    Wegehaupt, Florian J; Tauböck, Tobias T; Sener, Beatrice; Attin, Thomas

    2012-05-01

    To test sealants to prevent erosive tooth wear caused by extrinsic and intrinsic acids under long-term exposition. 144 bovine enamel samples were randomly allocated to twelve groups (1-12). Samples of groups 1, 5 and 9 remained unsealed (positive controls), 2, 6 and 10 were sealed with Silicon Seal Nano Mix and 3, 7 and 11 with Seal&Protect. Groups 4, 8 and 12 were sealed with flowable composite (negative controls). Groups 1-4 were immersed in artificial saliva, 5-8 in hydrochloric acid and groups 9-12 in citric acid for 28 days, respectively. After 1, 2, 4, 7, 11, 14, 21 and 28 days, solutions were renewed and enamel wear was quantified by assignation of (32)P in the solutions. In all immersion solutions, lowest mineral loss was observed for the negative controls whilst highest loss was observed for unsealed positive controls. In artificial saliva and citric acid, the loss from samples sealed with Seal&Protect was not significantly different compared with negative controls whilst loss in groups sealed with Silicon Seal Nano Mix was significantly higher. In hydrochloric acid, loss from samples sealed with Seal&Protect was not different compared with that of negative controls up to 4 days. Except day 1, the mineral loss in the Seal&Protect group was significantly lower compared with that of the Silicon Seal Nano Mix group. The tested resin based surface sealant is able to significantly reduce the erosive demineralisation of enamel caused by hydrochloric and citric acid even under long-term exposition. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Sea surface height evidence for long-term warming effects of tropical cyclones on the ocean.

    Science.gov (United States)

    Mei, Wei; Primeau, François; McWilliams, James C; Pasquero, Claudia

    2013-09-17

    Tropical cyclones have been hypothesized to influence climate by pumping heat into the ocean, but a direct measure of this warming effect is still lacking. We quantified cyclone-induced ocean warming by directly monitoring the thermal expansion of water in the wake of cyclones, using satellite-based sea surface height data that provide a unique way of tracking the changes in ocean heat content on seasonal and longer timescales. We find that the long-term effect of cyclones is to warm the ocean at a rate of 0.32 ± 0.15 PW between 1993 and 2009, i.e., ∼23 times more efficiently per unit area than the background equatorial warming, making cyclones potentially important modulators of the climate by affecting heat transport in the ocean-atmosphere system. Furthermore, our analysis reveals that the rate of warming increases with cyclone intensity. This, together with a predicted shift in the distribution of cyclones toward higher intensities as climate warms, suggests the ocean will get even warmer, possibly leading to a positive feedback.

  12. Hanford Site Long-term Surface Barrier Development Program: Fiscal year 1994 highlights

    International Nuclear Information System (INIS)

    Petersen, K.L.; Link, S.O.; Gee, G.W.

    1995-08-01

    The Hanford Site Surface Barrier Development Program was organized in 1985 to test the effectiveness of various barrier designs in minimizing the effects of water infiltration; plant, animal and human intrusion; and wind and water erosion on buried wastes, plus preventing or minimizing the emanation of noxious gases. A team of scientists from the Pacific Northwest Laboratory (PNL) and engineers from Westinghouse Hanford Company (WHC) direct the barrier development effort. ICF Kaiser Hanford Company, in conjunction with WHC and PNL, developed design drawings and construction specifications for a 5-acre prototype barrier. The highlight of efforts in FY 1994 was the construction of the prototype barrier. The prototype barrier was constructed on the Hanford Site at the 200 BP-1 Operable Unit of the 200 East Area. Construction was completed in August 1994 and monitoring instruments are being installed so experiments on the prototype barrier can begin in FY 1995. The purpose of the prototype barrier is to provide insights and experience with issues regarding barrier design, construction, and performance that have not been possible with individual tests and experiments conducted to date. Additional knowledge and experience was gained in FY 1994 on erosion control, physical stability, water infiltration control, model testing, Resource Conservation and Recovery Act (RCRA) comparisons, biointrusion control, long-term performance, and technology transfer

  13. Hanford Site Long-term Surface Barrier Development Program: Fiscal year 1994 highlights

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, K.L.; Link, S.O.; Gee, G.W.

    1995-08-01

    The Hanford Site Surface Barrier Development Program was organized in 1985 to test the effectiveness of various barrier designs in minimizing the effects of water infiltration; plant, animal and human intrusion; and wind and water erosion on buried wastes, plus preventing or minimizing the emanation of noxious gases. A team of scientists from the Pacific Northwest Laboratory (PNL) and engineers from Westinghouse Hanford Company (WHC) direct the barrier development effort. ICF Kaiser Hanford Company, in conjunction with WHC and PNL, developed design drawings and construction specifications for a 5-acre prototype barrier. The highlight of efforts in FY 1994 was the construction of the prototype barrier. The prototype barrier was constructed on the Hanford Site at the 200 BP-1 Operable Unit of the 200 East Area. Construction was completed in August 1994 and monitoring instruments are being installed so experiments on the prototype barrier can begin in FY 1995. The purpose of the prototype barrier is to provide insights and experience with issues regarding barrier design, construction, and performance that have not been possible with individual tests and experiments conducted to date. Additional knowledge and experience was gained in FY 1994 on erosion control, physical stability, water infiltration control, model testing, Resource Conservation and Recovery Act (RCRA) comparisons, biointrusion control, long-term performance, and technology transfer.

  14. Quantitation of MHC antigen expression on colorectal tumours and its association with tumour progression.

    OpenAIRE

    Durrant, L. G.; Ballantyne, K. C.; Armitage, N. C.; Robins, R. A.; Marksman, R.; Hardcastle, J. D.; Baldwin, R. W.

    1987-01-01

    A flow cytometric technique has been established for accurately quantitating the cell surface density of MHC antigens and the percentage of cells expressing MHC antigens in 38 colorectal tumours. Thirty-four percent of tumours were partially or completely negative for HLA-ABC antigen expression. Although the quantity of HLA-ABC antigens varied widely, there was no correlation between the density of HLA-ABC antigens, or the percentage of cells expressing these antigens and clinicopathological ...

  15. Can climate sensitivity be estimated from short-term relationships of top-of-atmosphere net radiation and surface temperature?

    International Nuclear Information System (INIS)

    Lin Bing; Min Qilong; Sun Wenbo; Hu Yongxiang; Fan, Tai-Fang

    2011-01-01

    Increasing the knowledge in climate radiative feedbacks is critical for current climate studies. This work focuses on short-term relationships between global mean surface temperature and top-of-atmosphere (TOA) net radiation. The relationships may be used to characterize the climate feedback as suggested by some recent studies. As those recent studies, an energy balance model with ocean mixed layer and both radiative and non-radiative heat sources is used here. The significant improvement of current model is that climate system memories are considered. Based on model simulations, short-term relationship between global mean surface temperature and TOA net radiation (or the linear striation feature as suggested by previous studies) might represent climate feedbacks when the system had no memories. However, climate systems with the same short-term feedbacks but different memories would have a similar linear striation feature. This linear striation feature reflects only fast components of climate feedbacks and may not represent the total climate feedback even when the memory length of climate systems is minimal. The potential errors in the use of short-term relationships in estimations of climate sensitivity could be big. In short time scales, fast climate processes may overwhelm long-term climate feedbacks. Thus, the climate radiative feedback parameter obtained from short-term data may not provide a reliable estimate of climate sensitivity. This result also suggests that long-term observations of global surface temperature and TOA radiation are critical in the understanding of climate feedbacks and sensitivities.

  16. Focal radiation therapy combined with 4-1BB activation and CTLA-4 blockade yields long-term survival and a protective antigen-specific memory response in a murine glioma model.

    Directory of Open Access Journals (Sweden)

    Zineb Belcaid

    Full Text Available Glioblastoma (GBM is the most common malignant brain tumor in adults and is associated with a poor prognosis. Cytotoxic T lymphocyte antigen -4 (CTLA-4 blocking antibodies have demonstrated an ability to generate robust antitumor immune responses against a variety of solid tumors. 4-1BB (CD137 is expressed by activated T lymphocytes and served as a co-stimulatory signal, which promotes cytotoxic function. Here, we evaluate a combination immunotherapy regimen involving 4-1BB activation, CTLA-4 blockade, and focal radiation therapy in an immune-competent intracranial GBM model.GL261-luciferace cells were stereotactically implanted in the striatum of C57BL/6 mice. Mice were treated with a triple therapy regimen consisted of 4-1BB agonist antibodies, CTLA-4 blocking antibodies, and focal radiation therapy using a small animal radiation research platform and mice were followed for survival. Numbers of brain-infiltrating lymphocytes were analyzed by FACS analysis. CD4 or CD8 depleting antibodies were administered to determine the relative contribution of T helper and cytotoxic T cells in this regimen. To evaluate the ability of this immunotherapy to generate an antigen-specific memory response, long-term survivors were re-challenged with GL261 glioma en B16 melanoma flank tumors.Mice treated with triple therapy had increased survival compared to mice treated with focal radiation therapy and immunotherapy with 4-1BB activation and CTLA-4 blockade. Animals treated with triple therapy exhibited at least 50% long-term tumor free survival. Treatment with triple therapy resulted in a higher density of CD4+ and CD8+ tumor infiltrating lymphocytes. Mechanistically, depletion of CD4+ T cells abrogated the antitumor efficacy of triple therapy, while depletion of CD8+ T cells had no effect on the treatment response.Combination therapy with 4-1BB activation and CTLA-4 blockade in the setting of focal radiation therapy improves survival in an orthotopic mouse

  17. Comparison of the binding properties of the mushroom Marasmius oreades lectin and Griffonia simplicifolia I-B isolectin to alphagalactosyl carbohydrate antigens in the surface phase

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Winter, Harry C; Goldstein, Irwin J

    2004-01-01

    and laminin from basement membrane of mouse sarcoma that contains the xenogenic Galalpha1-3Gal1-4GlcNAc epitope were immobilized in microtiter plate wells and lectin binding determined with an enzyme-linked assay. After 24 h of incubation, MOA had higher affinity for the xenogenic pentasaccharide (Galalpha1....... The results indicate that the Marasmius oreades lectin has nearly the same affinities as does GS I-B(4) for the simple xenogenic carbohydrate antigens, but MOA has greater affinity for the pentasaccharide and is far more specific in its binding preferences than the Griffonia lectin....

  18. Long-Term Follow-Up and Risk of Cancer Death After Radiation for Post-Prostatectomy Rising Prostate-Specific Antigen

    International Nuclear Information System (INIS)

    Swanson, Gregory P.; Du, Fei; Michalek, Joel E.; Hermans, Michael

    2011-01-01

    Purpose: The results of salvage radiation therapy for rising prostate-specific antigen (PSA) levels after radical prostatectomy appear favorable, but the ultimate outcome is uncertain, given the relatively short follow-up in most studies. We report on a group of patients at a median follow-up of 13.9 years after salvage radiation therapy. Methods and Materials: From 1990 to 1995, 92 patients were referred postoperatively for radiation for a rising PSA level. PSA level at the time of referral ranged from 0.1 to 30.5 ng/ml (median, 1.5 ng/ml). The median time from surgery to radiation was 2.1 years (range,, 0.3-7.4 years). Radiation was directed to the prostatic fossa only with a median dose of 6,500 cGy (range, 6,000-7,000 cGy). Results: Eighty-five patients experienced a PSA drop after radiation, as predicted by Gleason score and PSA level at the start of radiation. Five- and 10-year biochemical failure free survival (BFFS) was 35% and 26%, respectively, and overall survival was 86% and 67%, respectively. Median survival was 12.0 years, and median BFF was 2.3 years. The presurgery PSA level was not predictive, but the PSA level at the start of radiation predicted a response. Patients with Gleason 8 to 9 cancers had a significantly higher progression rate than those with lower Gleason scores. There were no significant differences in outcomes based on pathology findings (none vs. positive margins vs. positive seminal vesicles). Overall, 22 (24%) patients died directly from prostate cancer, resulting in a 10-year cancer-specific survival rate of 82%. Multivariate analysis risk factors for dying of cancer were Gleason's score (8 to 9) and PSA at the start of radiation therapy (>1.0 ng/ml). Conclusions: Patients have a good response to salvage radiation therapy. A small but durable subgroup appears to have permanent control. In those for whom therapy fails, radiation delays the need for other salvage therapy, indicating at least a transient benefit to most patients.

  19. Long-Term IgG Response to Porcine Neu5Gc Antigens without Transmission of PERV in Burn Patients Treated with Porcine Skin Xenografts

    Czech Academy of Sciences Publication Activity Database

    Scobie, L.; Padler-Karavani, V.; Les Bas-Bernardet, S.; Crossan, C.; Bláha, J.; Matoušková, Magda; Hector, R.D.; Cozzi, E.; Vanhove, B.; Charreau, B.; Blancho, G.; Bourdais, L.; Tallacchini, M.; Ribes, J.; Yu, H.; Chen, X.; Kracíková, J.; Brož, L.; Hejnar, Jiří; Veselý, Pavel; Takeuchi, Y.; Varki, A.; Soulillou, J.P.

    2013-01-01

    Roč. 191, č. 6 (2013), s. 2907-2915 ISSN 0022-1767 Grant - others:EK(XE) LSHB-CT-2006-037377 Source of funding: R - rámcový projekt EK Keywords : PERV transmission * xenotransplantation * long-term immune response Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.362, year: 2013

  20. Long-Term Stable Surface Treatments on CdTe and CdZnTe Radiation Detectors

    Science.gov (United States)

    Pekarek, Jakub; Belas, Eduard; Zazvorka, Jakub

    2017-04-01

    The spectral resolution and charge collection efficiency (CCE) of cadmium telluride (CdTe) and cadmium zinc telluride (CZT) room-temperature x-ray and gamma-ray detectors are often limited by high surface leakage current due to conducting surface species created during detector fabrication. Surface treatments play a major role in reduction of this surface leakage current. The effect of various types of surface etching and passivation on the leakage current and thereby the spectral energy resolution, CCE, and internal electric field profile of CdTe/CZT detectors has been studied. The main aim of this work is preparation of long-term stable detectors with strongly reduced leakage current. The time stability of the current-voltage characteristic and spectral resolution was investigated during 21 days and 1 year, respectively, after performing surface treatments. Our results suggest that the optimal detector preparation method is chemomechanical polishing in bromine-ethylene glycol solution followed by chemical etching in bromine-methanol solution then surface passivation in potassium hydroxide or ammonium fluoride (NH4F/H2O2). Detectors prepared using this optimal treatment exhibited low leakage current, high spectral resolution, and long-term stability compared with those subjected to other surface preparation methods.

  1. Solar irradiance at the earth's surface: long-term behavior observed at the South Pole

    Directory of Open Access Journals (Sweden)

    J. E. Frederick

    2011-02-01

    Full Text Available This research examines a 17-year database of UV-A (320–400 nm and visible (400–600 nm solar irradiance obtained by a scanning spectroradiometer located at the South Pole. The goal is to define the variability in solar irradiance reaching the polar surface, with emphasis on the influence of cloudiness and on identifying systematic trends and possible links to the solar cycle. To eliminate changes associated with the varying solar elevation, the analysis focuses on data averaged over 30–35 day periods centered on each year's austral summer solstice. The long-term average effect of South Polar clouds is a small attenuation, with the mean measured irradiances being about 5–6% less than the clear-sky values, although at any specific time clouds may reduce or enhance the signal that reaches the sensor. The instantaneous fractional attenuation or enhancement is wavelength dependent, where the percent deviation from the clear-sky irradiance at 400–600 nm is typically 2.5 times that at 320–340 nm. When averaged over the period near each year's summer solstice, significant correlations appear between irradiances at all wavelengths and the solar cycle as measured by the 10.7 cm solar radio flux. An approximate 1.8 ± 1.0% decrease in ground-level irradiance occurs from solar maximum to solar minimum for the wavelength band 320–400 nm. The corresponding decrease for 400–600 nm is 2.4 ± 1.9%. The best-estimate declines appear too large to originate in the sun. If the correlations have a geophysical origin, they suggest a small variation in atmospheric attenuation with the solar cycle over the period of observation, with the greatest attenuation occurring at solar minimum.

  2. Short term outcomes of prostate biopsy in men tested for cancer by prostate specific antigen: prospective evaluation within ProtecT study.

    Science.gov (United States)

    Rosario, Derek J; Lane, J Athene; Metcalfe, Chris; Donovan, Jenny L; Doble, Andy; Goodwin, Louise; Davis, Michael; Catto, James W F; Avery, Kerry; Neal, David E; Hamdy, Freddie C

    2012-01-09

    To measure the effect of the adverse events within 35 days of transrectal ultrasound guided biopsy from the perspective of asymptomatic men having prostate specific antigen (PSA) testing; to assess early attitude to re-biopsy; to estimate healthcare resource use associated with adverse events due to biopsy; and to develop a classification scheme for reporting adverse events after prostate biopsy. Prospective cohort study (Prostate Biopsy Effects: ProBE) nested within Prostate Testing for Cancer and Treatment (ProtecT) study. Participants Between 1999 and 2008, 227,000 community dwelling men aged 50-69 years were identified at 352 practices and invited to counselling about PSA testing. 111,148 attended a nurse led clinic in the community, and 10,297 with PSA concentrations of 3-20 ng/mL were offered biopsy within ProtecT. Between February 2006 and May 2008, 1147/1753 (65%) eligible men (mean age 62.1 years, mean PSA 5.4 ng/mL) having 10 core transrectal ultrasound guided biopsy under antibiotic cover in the context of ProtecT were recruited to the ProBE study. Purpose designed questionnaire administered at biopsy and 7 and 35 days after the procedure to measure frequency and effect of symptoms related to pain, infection, and bleeding; patients' attitude to repeat biopsy assessed immediately after biopsy and 7 days later; participants' healthcare resource use within 35 days of biopsy evaluated by questionnaire, telephone follow-up, and medical note review; each man's adverse event profile graded according to symptoms and healthcare use. Pain was reported by 429/984 (43.6%), fever by 172/985 (17.5%), haematuria by 642/976 (65.8%), haematochezia by 356/967 (36.8%), and haemoejaculate by 605/653 (92.6%) men during the 35 days after biopsy. Fewer men rated these symptoms as a major/moderate problem-71/977 (7.3%) for pain, 54/981 (5.5%) for fever, 59/958 (6.2%) for haematuria, 24/951 (2.5%) for haematochezia, and 172/646 (26.6%) for haemoejaculate. Immediately after

  3. Long-term evolution of the surface environment of the Campine area, Northern Belgium

    International Nuclear Information System (INIS)

    Beerten, K.; De Craen, M.; Brassinnes, S.; Wouters, L.

    2012-01-01

    Document available in extended abstract form only. The Boom Clay in the Campine Basin is studied as the reference host formation for the geological disposal of radioactive waste. Near Mol, it is covered by approximately 200 m of sediment which protects the clay layer. Here, we will give a preliminary assessment of the long-term evolution of the surface environment in the Campine area for the next 1 Ma, with respect to geomorphological, pedological and hydrological processes. The current surface environment started to develop after the last major marine regression around 2 Ma ago. Then, the climatic and tectonic evolution caused significant changes in surficial geology, relief intensity, soils and hydrography. The palaeo-geographical evolution during the Quaternary is characterized by important stream divergences, relative uplift and erosion. Tectonic uplift of the Campine Plateau forced the river Meuse to incise into the substrate. To the west, erosional processes shaped the Nete and the Lower Scheldt basins as a result of combined uplift and gradual sea-level drop. The Campine Plateau being covered by coarse fluvial deposits from the Early and Middle Pleistocene, is largely protected from erosion. The same is true for the Campine Cuesta, that stands out as a result of the cohesive and erosion resistant Kempen Clay substrate. Burial graphs covering the last few million years from different locations in the Boom Clay sub-crop zone reflect processes of subsidence, uplift, sea level variations and climate change in relation to the erodibility of the substrate. Continuous burial during the Quaternary as a result of subsidence is observed near the Dutch border, and for the Roer Valley Graben. Burial graphs for the Campine Plateau do not show important erosional phases during the last several million years. This is due to the protecting cover of coarse fluvial deposits. The area that is now occupied by the Lower Scheldt and the Nete basin has experienced erosion during

  4. Surface signature of Mediterranean water eddies in a long-term high-resolution simulation

    Science.gov (United States)

    Ciani, D.; Carton, X.; Barbosa Aguiar, A. C.; Peliz, A.; Bashmachnikov, I.; Ienna, F.; Chapron, B.; Santoleri, R.

    2017-12-01

    We study the surface signatures of Mediterranean water eddies (Meddies) in the context of a regional, primitive equations model simulation (using the Regional Oceanic Modeling System, ROMS). This model simulation was previously performed to study the mean characteristics and pathways of Meddies during their evolution in the Atlantic Ocean. The advantage of our approach is to take into account different physical mechanisms acting on the evolution of Meddies and their surface signature, having full information on the 3D distribution of all physical variables of interest. The evolution of around 90 long-lived Meddies (whose lifetimes exceeded one year) was investigated. In particular, their surface signature was determined in sea-surface height, temperature and salinity. The Meddy-induced anomalies were studied as a function of the Meddy structure and of the oceanic background. We show that the Meddies can generate positive anomalies in the elevation of the oceanic free-surface and that these anomalies are principally related to the Meddies potential vorticity structure at depth (around 1000 m below the sea-surface). On the contrary, the Meddies thermohaline surface signatures proved to be mostly dominated by local surface conditions and little correlated to the Meddy structure at depth. This work essentially points out that satellite altimetry is the most suitable approach to track subsurface vortices from observations of the sea-surface.

  5. Facts on the fragmentation of antigens in presenting cells, on the association of antigen fragments with MHC molecules in cell-free systems, and speculation on the cell biology of antigen processing

    DEFF Research Database (Denmark)

    Werdelin, O; Mouritsen, S; Petersen, B L

    1988-01-01

    The processing of a protein antigen is a multi-step event taking place in antigen-presenting cells. Processing is a prerequisite for the recognition of most antigens by T lymphocytes. The antigen is ingested by endocytosis, transported to an acid cellular compartment and subjected to proteolytic...... fragmentation. Some of the antigen fragments bind to MHC class II molecules and are transported to the surface of the antigen-presenting cell where the actual presentation to T lymphocytes occurs. The nature of the processed antigen, how and where it is derived and subsequently becomes associated with MHC...

  6. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans

    Science.gov (United States)

    Masure, Dries; Wang, Tao; Nejsum, Peter; Hokke, Cornelis H.; Geldhof, Peter

    2016-01-01

    Background The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential. Methodology/Principal Findings Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12) that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively) and specificity (95.5% and 90.0%) in pigs and humans, respectively. Conclusions/Significance These findings show the presence of a highly stage specific, glycolipid-like component (As12) that is actively secreted by infectious Ascaris larvae and which acts as a major antibody

  7. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans.

    Science.gov (United States)

    Vlaminck, Johnny; Masure, Dries; Wang, Tao; Nejsum, Peter; Hokke, Cornelis H; Geldhof, Peter

    2016-12-01

    The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential. Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12) that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively) and specificity (95.5% and 90.0%) in pigs and humans, respectively. These findings show the presence of a highly stage specific, glycolipid-like component (As12) that is actively secreted by infectious Ascaris larvae and which acts as a major antibody target in infected humans and pigs.

  8. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans.

    Directory of Open Access Journals (Sweden)

    Johnny Vlaminck

    2016-12-01

    Full Text Available The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential.Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12 that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively and specificity (95.5% and 90.0% in pigs and humans, respectively.These findings show the presence of a highly stage specific, glycolipid-like component (As12 that is actively secreted by infectious Ascaris larvae and which acts as a major antibody target in infected humans and pigs.

  9. Long-term monitoring of geodynamic surface deformation using SAR interferometry

    Science.gov (United States)

    Gong, Wenyu

    Synthetic Aperture Radar Interferometry (InSAR) is a powerful tool to measure surface deformation and is well suited for surveying active volcanoes using historical and existing satellites. However, the value and applicability of InSAR for geodynamic monitoring problems is limited by the influence of temporal decorrelation and electromagnetic path delay variations in the atmosphere, both of which reduce the sensitivity and accuracy of the technique. The aim of this PhD thesis research is: how to optimize the quantity and quality of deformation signals extracted from InSAR stacks that contain only a low number of images in order to facilitate volcano monitoring and the study of their geophysical signatures. In particular, the focus is on methods of mitigating atmospheric artifacts in interferograms by combining time-series InSAR techniques and external atmospheric delay maps derived by Numerical Weather Prediction (NWP) models. In the first chapter of the thesis, the potential of the NWP Weather Research & Forecasting (WRF) model for InSAR data correction has been studied extensively. Forecasted atmospheric delays derived from operational High Resolution Rapid Refresh for the Alaska region (HRRR-AK) products have been compared to radiosonding measurements in the first chapter. The result suggests that the HRRR-AK operational products are a good data source for correcting atmospheric delays in spaceborne geodetic radar observations, if the geophysical signal to be observed is larger than 20 mm. In the second chapter, an advanced method for integrating NWP products into the time series InSAR workflow is developed. The efficiency of the algorithm is tested via simulated data experiments, which demonstrate the method outperforms other more conventional methods. In Chapter 3, a geophysical case study is performed by applying the developed algorithm to the active volcanoes of Unimak Island Alaska (Westdahl, Fisher and Shishaldin) for long term volcano deformation

  10. Long-Term Monitoring of Regional Sea Surface Height Variability Using High-Resolution Satellite Altimetry

    Science.gov (United States)

    Rice, A. E.; Crout, R. L.

    2017-12-01

    Shallow water altimetry is an emerging field that in recent years has rapidly gained attention for both the numerous applications it can offer to the oceanographic community (e.g. assessment of climate change impacts to the coastal zone; quantification of sea state etc.) and, depending on the altimeter used, for the wealth of available historical data that can be employed for climatological studies. In this study we focus on the long-term analysis of regional sea surface height anomaly (SSHA) variability over the mid and outer shelf (≥ 16 km from the coast) for 18 selected coastal altimeter tracks located on the east coast of the US and Asia for a period of eight years (294 passes from July 2008 to July 2016) using Jason-2 20 Hz altimeter data from the L2 AVISO-PISTACH experimental products. After implementing geophysical corrections to the raw altimeter range, signal noise in the individual SSH passes was reduced by applying a median filter followed by a 60-point (18 km) low-pass filter as in Birol and Delebeque (2014). Since individual altimeter passes did not cease to collect data at the same distance from the coastline, a nearest-point-to-land (NPTL) was determined for each track for statistical analysis of the data. NPTL time series and SSHA envelopes, computed by subtracting mean SSHAs from individual passes, were used for the analysis. A comparison of wind and water level gauge data to a US east coast track reveals correlation between SSHA and winds and a relationship to subtidal water level frequencies. Time series of NPTL for all tracks show intra-annual and inter and intra-seasonal variability, with higher and lower water levels linked to seasons. Lastly, envelope plots display higher SSHA variability over the mid shelf than the outer shelf, revealing the location and magnitude (up to 0.5 m water level differences) of setup and set down occurrences. Various products derived from the analysis that are useful for oceanographic operations, including water

  11. Probabilistic cost-effectiveness analysis of the long-term effect of universal hepatitis B vaccination: an experience from Taiwan with high hepatitis B virus infection and Hepatitis B e Antigen positive prevalence.

    Science.gov (United States)

    Hung, Hui-Fang; Chen, Tony Hsiu-Hsi

    2009-11-12

    To assess cost-effectiveness of hepatitis B virus (HBV) vaccination strategies from health care payer and societal perspectives, focusing on the long-term effect, in Taiwan where prevalence of HBV and Hepatitis B e Antigen (HBeAg) is high. A decision analysis was performed to compare total costs and effectiveness between two vaccination strategies: universal vaccination and no-vaccination. The Markov process was defined as a series of states including acute HBV infection, asymptomatic carrier, chronic hepatitis, compensated and decompensated liver cirrhosis, hepatoma, and death. Direct and indirect costs were also imputed based on estimates. The incremental cost-effectiveness ratio (ICER) per life-year gained and quality-adjusted life years gained were calculated at a 3% discount rate. By assigning a series of specific distributions to each parameter, a probabilistic cost-effective analysis using Monte Carlo simulation was conducted to yield 5000 ICER replicates. The effectiveness of a universal vaccination program for reducing hepatocellular carcinoma cases and deaths was approximately 86%. The average life years gained per subject as a result of such a universal vaccination was 3.9. The vaccination program dominated over a no-vaccination program (less cost and more effectiveness). A universal vaccination program against hepatitis B infection is not only effective for reducing long-term sequelae but is also a cost-saving primary preventive strategy, which supports a universal infant immunization in endemic area with high prevalence of HBV and HBeAg.

  12. Vaccination and antigenic drift in influenza.

    Science.gov (United States)

    Boni, Maciej F

    2008-07-18

    The relationship between influenza antigenic drift and vaccination lies at the intersection of evolutionary biology and public health, and it must be viewed and analyzed in both contexts simultaneously. In this paper, 1 review what is known about the effects of antigenic drift on vaccination and the effects of vaccination on antigenic drift, and I suggest some simple ways to detect the presence of antigenic drift in seasonal influenza data. If antigenic drift occurs on the time scale of a single influenza season, it may be associated with the presence of herd immunity at the beginning of the season and may indicate a need to monitor for vaccine updates at the end of the season. The relationship between antigenic drift and vaccination must also be viewed in the context of the global circulation of influenza strains and the seeding of local and regional epidemics. In the data sets I consider--from New Zealand, New York, and France--antigenic drift can be statistically detected during some seasons, and seeding of epidemics appears to be endogenous sometimes and exogenous at other times. Improved detection of short-term antigenic drift and epidemic seeding would significantly benefit influenza monitoring efforts and vaccine selection.

  13. Rapid detection and semi-quantification of IgG-accessible Staphylococcus aureus surface-associated antigens using a multiplex competitive Luminex assay

    NARCIS (Netherlands)

    Hansenova Manaskova, S.; Bikker, F.J.; Veerman, E.C.I.; van Belkum, A.; van Wamel, W.J.B.

    2013-01-01

    The surface characterization of Staphylococcus aureus is currently labor intensive and time consuming. Therefore, we developed a novel method for the rapid yet comprehensive characterization of S. aureus cell-surface-associated proteins and carbohydrates, based on a competitive Luminex assay. In

  14. The Increased Production Efficiency and Optimization Terms of Stationarity by Flat Grinding with Abrasive Circle Surface

    Directory of Open Access Journals (Sweden)

    Husseinov Hassan Ahmad

    2014-01-01

    Full Text Available This scientific work deals with the production area. The paper investigates the problems related to the uneven abrasive effect on the processed surface by flat grinding with the abrasive circle surface, and the analytical expression of pattern distribution of the working abrasive grain within the limits of various technological primitives and inaccuracy of geometric shape have been determined. The ways of stationary provision of the grinding surface have been suggested. This paper also focuses on the economic efficiency of the production.

  15. Short-term adhesion and long-term biofouling testing of polydopamine and poly(ethylene glycol) surface modifications of membranes and feed spacers for biofouling control

    KAUST Repository

    Miller, Daniel J.

    2012-08-01

    Ultrafiltration, nanofiltration membranes and feed spacers were hydrophilized with polydopamine and polydopamine- g-poly(ethylene glycol) surface coatings. The fouling propensity of modified and unmodified membranes was evaluated by short-term batch protein and bacterial adhesion tests. The fouling propensity of modified and unmodified membranes and spacers was evaluated by continuous biofouling experiments in a membrane fouling simulator. The goals of the study were: 1) to determine the effectiveness of polydopamine and polydopamine- g-poly(ethylene glycol) membrane coatings for biofouling control and 2) to compare techniques commonly used in assessment of membrane biofouling propensity with biofouling experiments under practical conditions. Short-term adhesion tests were carried out under static, no-flow conditions for 1 h using bovine serum albumin, a common model globular protein, and Pseudomonas aeruginosa, a common model Gram-negative bacterium. Biofouling tests were performed in a membrane fouling simulator (MFS) for several days under flow conditions similar to those encountered in industrial modules with the autochthonous drinking water population and acetate dosage as organic substrate. Polydopamine- and polydopamine- g-poly(ethylene glycol)-modified membranes showed significantly reduced adhesion of bovine serum albumin and P. aeruginosa in the short-term adhesion tests, but no reduction of biofouling was observed during longer biofouling experiments with modified membranes and spacers. These results demonstrate that short-term batch adhesion experiments using model proteins or bacteria under static conditions are not indicative of biofouling, while continuous biofouling experiments showed that membrane surface modification by polydopamine and polydopamine- g-poly(ethylene glycol) is not effective for biofouling control. © 2012 Elsevier Ltd.

  16. Surface hardness of different restorative materials after long-term immersion in sports and energy drinks.

    Science.gov (United States)

    Erdemir, Ugur; Yildiz, Esra; Eren, Meltem Mert; Ozel, Sevda

    2012-01-01

    The purpose of this study was to evaluate the effect of sports and energy drinks on the surface hardness of different restorative materials over a 6-month period. Forty-two disk-shaped specimens were prepared for each of the four restorative materials tested: Compoglass F, Filtek Z250, Filtek Supreme, and Premise. Specimens were immersed for 2 min daily, up to 6 months, in six storage solutions (n=7 per material for each solution): distilled water, Powerade, Gatorade, X-IR, Burn, and Red Bull. Surface hardness was measured at baseline, after 1 week, 1 month, and 6 months. Data were analyzed statistically using repeated measures ANOVA followed by the Bonferroni test for multiple comparisons (α=0.05). Surface hardness of the restorative materials was significantly affected by both immersion solution and immersion period (p<0.001). All tested solutions induced significant reduction in surface hardness of the restorative materials over a 6-month immersion period.

  17. Polymer-Based Surfaces Designed to Reduce Biofilm Formation: From Antimicrobial Polymers to Strategies for Long-Term Applications.

    Science.gov (United States)

    Riga, Esther K; Vöhringer, Maria; Widyaya, Vania Tanda; Lienkamp, Karen

    2017-10-01

    Contact-active antimicrobial polymer surfaces bear cationic charges and kill or deactivate bacteria by interaction with the negatively charged parts of their cell envelope (lipopolysaccharides, peptidoglycan, and membrane lipids). The exact mechanism of this interaction is still under debate. While cationic antimicrobial polymer surfaces can be very useful for short-term applications, they lose their activity once they are contaminated by a sufficiently thick layer of adhering biomolecules or bacterial cell debris. This layer shields incoming bacteria from the antimicrobially active cationic surface moieties. Besides discussing antimicrobial surfaces, this feature article focuses on recent strategies that were developed to overcome the contamination problem. This includes bifunctional materials with simultaneously presented antimicrobial and protein-repellent moieties; polymer surfaces that can be switched from an antimicrobial, cell-attractive to a cell-repellent state; polymer surfaces that can be regenerated by enzyme action; degradable antimicrobial polymers; and antimicrobial polymer surfaces with removable top layers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A unified account of perceptual layering and surface appearance in terms of gamut relativity.

    Science.gov (United States)

    Vladusich, Tony; McDonnell, Mark D

    2014-01-01

    When we look at the world--or a graphical depiction of the world--we perceive surface materials (e.g. a ceramic black and white checkerboard) independently of variations in illumination (e.g. shading or shadow) and atmospheric media (e.g. clouds or smoke). Such percepts are partly based on the way physical surfaces and media reflect and transmit light and partly on the way the human visual system processes the complex patterns of light reaching the eye. One way to understand how these percepts arise is to assume that the visual system parses patterns of light into layered perceptual representations of surfaces, illumination and atmospheric media, one seen through another. Despite a great deal of previous experimental and modelling work on layered representation, however, a unified computational model of key perceptual demonstrations is still lacking. Here we present the first general computational model of perceptual layering and surface appearance--based on a boarder theoretical framework called gamut relativity--that is consistent with these demonstrations. The model (a) qualitatively explains striking effects of perceptual transparency, figure-ground separation and lightness, (b) quantitatively accounts for the role of stimulus- and task-driven constraints on perceptual matching performance, and (c) unifies two prominent theoretical frameworks for understanding surface appearance. The model thereby provides novel insights into the remarkable capacity of the human visual system to represent and identify surface materials, illumination and atmospheric media, which can be exploited in computer graphics applications.

  19. Surface clay formation during short-term warmer and wetter conditions on a largely cold ancient Mars

    Science.gov (United States)

    Bishop, Janice L.; Fairén, Alberto G.; Michalski, Joseph R.; Gago-Duport, Luis; Baker, Leslie L.; Velbel, Michael A.; Gross, Christoph; Rampe, Elizabeth B.

    2018-03-01

    The ancient rock record for Mars has long been at odds with climate modelling. The presence of valley networks, dendritic channels and deltas on ancient terrains points towards running water and fluvial erosion on early Mars1, but climate modelling indicates that long-term warm conditions were not sustainable2. Widespread phyllosilicates and other aqueous minerals on the Martian surface3-6 provide additional evidence that an early wet Martian climate resulted in surface weathering. Some of these phyllosilicates formed in subsurface crustal environments5, with no association with the Martian climate, while other phyllosilicate-rich outcrops exhibit layered morphologies and broad stratigraphies7 consistent with surface formation. Here, we develop a new geochemical model for early Mars to explain the formation of these clay-bearing rocks in warm and wet surface locations. We propose that sporadic, short-term warm and wet environments during a generally cold early Mars enabled phyllosilicate formation without requiring long-term warm and wet conditions. We conclude that Mg-rich clay-bearing rocks with lateral variations in mixed Fe/Mg smectite, chlorite, talc, serpentine and zeolite occurrences formed in subsurface hydrothermal environments, whereas dioctahedral (Al/Fe3+-rich) smectite and widespread vertical horizonation of Fe/Mg smectites, clay assemblages and sulphates formed in variable aqueous environments on the surface of Mars. Our model for aluminosilicate formation on Mars is consistent with the observed geological features, diversity of aqueous mineralogies in ancient surface rocks and state-of-the-art palaeoclimate scenarios.

  20. AntigenMap 3D: an online antigenic cartography resource.

    Science.gov (United States)

    Barnett, J Lamar; Yang, Jialiang; Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2012-05-01

    Antigenic cartography is a useful technique to visualize and minimize errors in immunological data by projecting antigens to 2D or 3D cartography. However, a 2D cartography may not be sufficient to capture the antigenic relationship from high-dimensional immunological data. AntigenMap 3D presents an online, interactive, and robust 3D antigenic cartography construction and visualization resource. AntigenMap 3D can be applied to identify antigenic variants and vaccine strain candidates for pathogens with rapid antigenic variations, such as influenza A virus. http://sysbio.cvm.msstate.edu/AntigenMap3D

  1. Antigens of Streptococcus sanguis

    Science.gov (United States)

    Rosan, Burton

    1973-01-01

    An antigenic analysis of the alpha-hemolytic streptococci isolated from dental plaque was performed by use of antisera against a strain of Streptococcus sanguis (M-5) which was isolated from dental plaque. Immunoelectrophoretic and Ouchterlony tests of Rantz and Randall extracts of 45 strains gave positive reactions with the M-5 antisera. These strains represented 60% of the strains tested. The number of antigens which could be identified in these extracts varied from one to five and were designated a to e. The a antigen was found in 36 of the strains tested, including reference strains of S. sanguis and the group H streptococci. The strains reacting with the M-5 antisera were divided into two majors types: type I consisted of 23 strains in which the a antigen was found alone or with one or more of the c, d, and e antigens; type II consisted of 13 strains in which both the a and b antigens were found with or without one or more of the c, d, and e antigens. The remaining strains contained, either singly or in combination, the b, c, d, and e antigens but not the a antigen. Biochemical tests of representatives of each serotype and reference strains indicated that strains reacting with M-5 antisera were S. sanguis. These findings suggest that S. sanguis strains share common physiological and serological properties. Images PMID:4633291

  2. Prevalence and chemotherapy-induced reactivation of occult hepatitis B virus among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma: Significance of hepatitis B core antibodies screening

    International Nuclear Information System (INIS)

    Elbedewy, T.A.; Elashtokhy, H.A.; Rabee, E.S.; Kheder, G.E.

    2015-01-01

    Background: Occult hepatitis B infection (OBI) is characterized by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV)-DNA in the liver and/or serum, with or without hepatitis B core antibody (anti-HBc). Anti-HBc is the most sensitive marker of previous HBV. HBV reactivation in patients under immunosuppressive treatment is life-threatening, occurring in both overt and occult HBV especially in hematological malignancies. Aim of the work: To evaluate the prevalence and chemotherapy-induced reactivation of OBI among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma (DLBCL) patients and to determine the significance of anti-HBc screening among this group of patients before receiving chemotherapy. Patients and methods: This cross-sectional study included 72 DLBCL patients negative for HBsAg, HBsAb and hepatitis C virus antibodies (anti-HCV). Patients were subjected to investigations including anti-HBc. All patients underwent alanine transaminase (ALT) monitoring before each cycle of chemotherapy and monthly for 12 months after the end of chemotherapy. Patients with suspected OBI were tested for HBV-DNA using real-time polymerase chain reaction (PCR). Results: Anti-HBc was detected in 10 of 72 HBsAg negative sera (13.89%) (95% confidence interval 6.9-22.2%). Five of the 10 anti-HBc positive patients in this study had OBI reactivation. Conclusion: The study concluded that anti-HBc screening is mandatory before chemotherapy. HBsAg-negative/anti-HBc-positive patients should be closely observed for signs of HBV reactivation through the regular monitoring of ALT. Prophylaxis lamivudine is recommended for anti-HBc positive patients before chemotherapy.

  3. Micro patterned surfaces allow long-term digital holographic microscopy live cell imaging

    Science.gov (United States)

    Mues, Sarah; Lilge, Inga; Schönherr, Holger; Kemper, Björn; Schnekenburger, Jürgen

    2017-07-01

    During long-term imaging, cells move out of the field of view. We have generated functionalized substrates containing rectangular areas, which were capable in keeping cells over the whole observation period.

  4. Risk-based approach to long-term safety assessment for near surface disposal of radioactive waste in Korea

    International Nuclear Information System (INIS)

    Jeong, C.W.; Kim, K.I.; Lee, J.I.

    2000-01-01

    This paper presents the Korean regulatory approach to safety assessment consistent with probabilistic, risk-based long-term safety requirements for near surface disposal facilities. The approach is based on: (1) From the standpoint of risk limitation, normal processes and probabilistic disruptive events should be integrated in a similar manner in terms of potential exposures; and (2) The uncertainties inherent in the safety assessment should be reduced using appropriate exposure scenarios. In addition, this paper emphasizes the necessity of international guidance for quantifying potential exposures and the corresponding risks from radioactive waste disposal. (author)

  5. Calculation of Long-Term Averages of Surface Air Temperature Based on Insolation Data

    Science.gov (United States)

    Fedorov, V. M.; Grebennikov, P. B.

    2017-12-01

    The solar radiation coming to the Earth's ellipsoid is considered without taking into account the atmosphere on the basis of the astronomical ephemerides for the time interval from 3000 BC to 3000 AD. Using the regression equations between the Earth's insolation and near-surface air temperature, the insolation annual and semiannual climatic norms of near-surface air temperature for the Earth as a whole and the hemispheres are calculated in intervals of 30 years for the period from 2930 BC to 2930 AD with 100 and 900- to 1000-year time steps. The analysis shows that the annual insolation rates of the near-surface air temperature of the Earth and the hemispheres decrease at all intervals. The semiannual insolation rates of the near-surface air temperature increase in winter and decrease in summer. This means that the seasonal difference decreases. The annual and semiannual rates of insolation near-surface air temperature of the Earth increase in the equatorial and decrease in the polar regions; the latitudinal contrast increases. The interlatitudinal gradient is higher in the Southern Hemisphere. It practically does not change in winter and increases in summer, most strongly in the Southern Hemisphere.

  6. Nanoscale surfaces for the long-term maintenance of mesenchymal stem cell phenotype and multipotency

    Science.gov (United States)

    McMurray, Rebecca J.; Gadegaard, Nikolaj; Tsimbouri, P. Monica; Burgess, Karl V.; McNamara, Laura E.; Tare, Rahul; Murawski, Kate; Kingham, Emmajayne; Oreffo, Richard O. C.; Dalby, Matthew J.

    2011-08-01

    There is currently an unmet need for the supply of autologous, patient-specific stem cells for regenerative therapies in the clinic. Mesenchymal stem cell differentiation can be driven by the material/cell interface suggesting a unique strategy to manipulate stem cells in the absence of complex soluble chemistries or cellular reprogramming. However, so far the derivation and identification of surfaces that allow retention of multipotency of this key regenerative cell type have remained elusive. Adult stem cells spontaneously differentiate in culture, resulting in a rapid diminution of the multipotent cell population and their regenerative capacity. Here we identify a nanostructured surface that retains stem-cell phenotype and maintains stem-cell growth over eight weeks. Furthermore, the study implicates a role for small RNAs in repressing key cell signalling and metabolomic pathways, demonstrating the potential of surfaces as non-invasive tools with which to address the stem cell niche.

  7. Effects of irradiation, glucocorticoid and FK506 on cell-surface antigen expression by rat thymocytes: a three-colour flow cytofluorometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchida, M.; Konishi, M.; Takai, K.; Naito, K.; Fujikura, Y.; Fukumoto, T. (Yamaguchi Univ. (Japan). School of Medicine)

    1994-11-01

    The expression of T-cell antigen receptor (TCR) [alpha][beta] was investigated in rat CD4[sup -]CD8[sup -] thymocytes during thymic reconstitution after the exposure of animals to irradiation or glucocorticoid. The effect of the immunosuppressant FK506 on the expression of TCR[alpha][beta] in rat CD4[sup -]CD8[sup -] thymocytes was also examined. The percentage of CD4[sup -]CD8[sup -] thymocytes constituted 2.6% of total thymocytes and that of CD4[sup -]CD8[sup -]TCR[alpha][beta][sup high] cells constituted 12.6% of CD4[sup -]CD8[sup -]thymocytes in normal adult Lewis rats. The percentage of CD4[sup -]CD8[sup -] TCR[alpha][beta][sup high] cells increased during thymic reconstitution after irradiation, and maximally constituted 28.6% of CD4[sup -]CD8[sup -] thymocytes on day 7. Similar results were obtained during thymic reconstitution after glucocorticoid treatment. In contrast, continuous treatment with FK506 for 7 days markedly decreased not only the percentages of CD4[sup +]CD8[sup -]TCR[alpha][beta][sup high] and CD4[sup -]CD8[sup +] TCR[alpha][beta][sup high] thymocytes, but also that of CD4[sup -]CD8[sup -] TCR[alpha][beta][sup high] thymocytes. These results indicate that rat CD4[sup -]CD8[sup -] thymocytes contain a subpopulation of mature (TCR[alpha][beta][sup high]) cells. The possible implications of the existence of this subpopulation with regard to thymocyte differentiation and maturation are discussed. (author).

  8. Long-Term Stability of PEG-Based Antifouling Surfaces in a Marine Environment

    DEFF Research Database (Denmark)

    Noguer, Albert Camós; Kiil, Søren; Hvilsted, Søren

    The work presented here concerns the use of polyethylene glycol (PEG) to reduce marine biofouling on ship hulls. The long-term stability of PEG towards degradation in a marine environment is reviewed, and the results of experiments designed to test the degradation of polyethylene glycol moieties...... structure and the end-group on the degradation of different PEG-containing compounds in accelerated conditions, while showing very little degradation in real exposure tests in seawater after 3 months. Further experiments will be discussed involving long-term stability and degradation pathways involved...

  9. Particle track record in lunar silicates: long-term behavior of solar and galactic VH nuclei and lunar surface dynamics

    International Nuclear Information System (INIS)

    Yuhas, D.E.

    1974-01-01

    Stored nuclear particle tracks are abundant in all major mineral phases found on the moon. The track production in the near surface regions (depth less than 1 mm) is dominated by VH (Z greater than 20) cosmic rays of solar origin. At deeper depths (greater than 5 mm) heavy galactic cosmic rays dominate the production. The track profile (track density vs depth) is shaped by both the energy spectrum of impinging VH nuclei and dynamical processes which change rock surfaces with time. The analyses of track records in a number of lunar rocks with different surface exposure histories yield information about both dynamical processes on the moon and the long-term time behavior of solar and galactic cosmic rays. (Diss. Abstr. Int., B)

  10. Expressions of the radius and the surface tension of surface of tension in terms of the pressure distribution for nanoscale liquid threads

    International Nuclear Information System (INIS)

    Yan Hong; Wei Jiu-An; Cui Shu-Wen; Zhu Ru-Zeng

    2013-01-01

    The expressions of the radius and the surface tension of surface of tension R s and γ s in terms of the pressure distribution for nanoscale liquid threads are of great importance for molecular dynamics (MD) simulations of the interfacial phenomena of nanoscale fluids; these two basic expressions are derived in this paper. Although these expressions were derived first in the literature [Kim B G, Lee J S, Han M H, and Park S, 2006 Nanoscale and Microscale Thermophysical Engineering, 10, 283] and used widely thereafter, the derivation is wrong both in logical structure and physical thought. In view of the importance of these basic expressions, the logic and physical mistakes appearing in that derivation are pointed out. (condensed matter: structural, mechanical, and thermal properties)

  11. Presence or absence of a known diabetic ketoacidosis precipitant defines distinct syndromes of "A-β+" ketosis-prone diabetes based on long-term β-cell function, human leukocyte antigen class II alleles, and sex predilection.

    Science.gov (United States)

    Nalini, Ramaswami; Ozer, Kerem; Maldonado, Mario; Patel, Sanjeet G; Hampe, Christiane S; Guthikonda, Anu; Villanueva, Jesus; O'Brian Smith, E; Gaur, Lakshmi K; Balasubramanyam, Ashok

    2010-10-01

    Ketosis-prone diabetes (KPD) is heterogeneous. Longitudinal follow-up revealed that patients with "A-β+" KPD (absent autoantibodies and preserved β-cell function) segregated into 2 subgroups with distinct evolution of β-cell function and glycemic control. Generalized linear analysis demonstrated that the variable that most significantly differentiated them was presence of a clinically evident precipitating event for the index diabetic ketoacidosis (DKA). Hence, we performed a comprehensive analysis of A-β+ KPD patients presenting with "provoked" compared with "unprovoked" DKA. Clinical, biochemical, and β-cell functional characteristics were compared between provoked and unprovoked A-β+ KPD patients followed prospectively for 1 to 8 years. Human leukocyte antigen class II allele frequencies were compared between these 2 groups and population controls. Unprovoked A-β+ KPD patients (n = 83) had greater body mass index, male preponderance, higher frequency of women with oligo-/anovulation, more frequent African American ethnicity, and less frequent family history of diabetes than provoked A-β+ KPD patients (n = 64). The provoked group had higher frequencies of the human leukocyte antigen class II type 1 diabetes mellitus susceptibility alleles DQB1*0302 (than the unprovoked group or population controls) and DRB1*04 (than the unprovoked group), whereas the unprovoked group had a higher frequency of the protective allele DQB1*0602. β-Cell secretory reserve and glycemic control improved progressively in the unprovoked group but declined in the provoked group. The differences persisted in comparisons restricted to patients with new-onset diabetes. "Unprovoked" A-β+ KPD is a distinct syndrome characterized by reversible β-cell dysfunction with male predominance and increased frequency of DQB1*0602, whereas "provoked" A-β+ KPD is characterized by progressive loss of β-cell reserve and increased frequency of DQB1*0302 and DRB1*04. Unprovoked DKA predicts long-term

  12. Adenovirus 5 and 35 vectors expressing Plasmodium falciparum circumsporozoite surface protein elicit potent antigen-specific cellular IFN-gamma and antibody responses in mice

    NARCIS (Netherlands)

    Shott, Joseph P.; McGrath, Shannon M.; Pau, Maria Grazia; Custers, Jerome H. V.; Ophorst, Olga; Demoitié, Marie-Ange; Dubois, Marie-Claude; Komisar, Jack; Cobb, Michelle; Kester, Kent E.; Dubois, Patrice; Cohen, Joe; Goudsmit, Jaap; Heppner, D. Gray; Stewart, V. Ann

    2008-01-01

    Falciparum malaria vaccine candidates have been developed using recombinant, replication-deficient serotype 5 and 35 adenoviruses (Ad5, Ad35) encoding the Plasmodium falciparum circumsporozoite surface protein (CSP) (Ad5.CS, Ad35.CS) (Crucell Holland BV, Leiden, The Netherlands). To evaluate the

  13. Eosinofil Sel Penyaji Antigen

    Directory of Open Access Journals (Sweden)

    Safari Wahyu Jatmiko

    2015-04-01

    Full Text Available Sel eosinofil merupakan jenis sel lekosit yang terlibat dalam berbagai patogenesis penyakit. Sel eosinofil pada awalnya dikenal sebagai sel efektor  dari sistem imunitas alamiah. Akan tetapi, kemampuan sel eosinofil dalam memfagositosis patogen menimbulkan dugaan bahwa sel eosinofil ikut berperan sebagai sel penyaji antigen. Hal ini dianalogikan dengan sel makrofag dan sel dendritik yang bisa memfagositosis dan menyajikan antigen sebagai hasil dari degradasi patogen yang difagositosis. Untuk menjawab permasalahan ini, penulis melakukan penelusuran artikel tentang eosinofil sebagai sel penyaji antigen melalui US National Library of Medicine National Institute of Healthdengan kata kunci eoshinophil dan antigen presenting cell. Hasil penelusuran adalah ditemukannya 10 artikel yang relevan dengan topik. Hasil dari sintesis kesepuluh jurnal tersebut adalah sel eosinofil mampu berperan sebagai sel penyaji antigen yang profesional (professionalantigenpresentng cell

  14. Short-term forecasting of lightning based on the surface wind field at Kennedy Space Center

    Science.gov (United States)

    Watson, Andrew I.; Lopez, Raul E.; Ortiz, Robert; Holle, Ronald L.

    1987-01-01

    Cloud-to-ground lightning is related in time and space to surface convergence for 244 days during the summer over a 790 sqkm network. The method uses surface convergence, particularly the average over the area, to identify the potential for new, local thunderstorm growth, and can be used to specify the likely time and location of lightning during the life cycle of the convection. A threshold of 0.0000075/sec change in divergence is used to define a convergence event, and a separation of 30 min between flashes defines a lightning event. Time intervals are found to be on the order of 1 hr from beginning convergence to first flash, and (CH110) 2 hr from beginning convergence to the end of lightning. Major differences between the convergence-lightning relationships based on low-level mean onshore and offshore flow are noted.

  15. A preliminary evaluation of short-term thunderstorm forecasting using surface winds at Kennedy Space Center

    Science.gov (United States)

    Watson, Andrew I.; Holle, Ronald L.; Lopez, Raul E.; Nicholson, James R.

    1990-01-01

    In 1987 NASA expanded its surface wind network onto the mainland west of Kennedy Space Center, increasing the network area from nearly 800 sq km to over 1600 sq km. Here, the results of this expansion are reported using three years of wind and lightning information collected during June, July, August, and September of 1987, 1988, and 1989. The divergence-lightning relationships and the importance of wind direction are addressed, and the verification is summarized.

  16. Transitioning MODIS to VIIRS observations for Land: Surface Reflectance results, Status and Long-term Prospective

    Science.gov (United States)

    Vermote, E.

    2015-12-01

    Surface reflectance is one of the key products from VIIRS and as with MODIS, is used in developing several higher-order land products. The VIIRS Surface Reflectance (SR) IP is based on the heritage MODIS Collection 5 product (Vermote et al. 2002). The quality and character of surface reflectance depends on the accuracy of the VIIRS Cloud Mask (VCM) and aerosol algorithms and of course on the adequate calibration of the sensor. Early evaluation of the VIIRS SR product in the context of the maturity of the operational processing system known as the Interface Data Processing System (IDPS), has been a major focus of work to-date, but is now evolving into the development of a VIIRS suite of Climate Data Records produced by the NASA Land Science Investigator Processing System (SIPS). We will present the calibration performance and the role of the surface reflectance in calibration monitoring, the performance of the cloud mask with a focus on vegetation monitoring (no snow conditions), the performance of the aerosol input used in the atmospheric correction with quantitative results of the performance of the SR product over AERONET sites. Based on those elements and further assessment, we will address the readiness of the SR product for the production of higher-order land products such as Vegetation Indices, Albedo and LAI/FPAR, the its application to agricultural monitoring and in particular the integration of VIIRS data into the global agricultural monitoring (GLAM) system developed at UMd. Finally from the lessons learned, we will articulate a set of critical recommendations to ensure consistency and continuity of the JPSS mission with the MODIS data record.

  17. Specification of the surface figure and finish of optical elements in terms of system performance

    International Nuclear Information System (INIS)

    Church, E.L.; Takacs, P.Z.

    1992-09-01

    Brookhaven National Laboratory is the site of the National Synchrotron Light Source (NSLS); an electron synchrotron which is an intense source of hard and soft x-rays. Since there are no effective refracting elements for x rays, this radiation must be manipulated and focused by mirrors configured to give high reflectivity. This paper describes methods of predicting the degradation of the performance of a simple imaging system in terms of the statistics of the shape errors of the focusing element, and conversely, of specifying those statistics in terms of requirements on image quality. Results are illustrated for a normal-incidence x-ray mirrors having figure errors plus conventional and/or fractal finish errors

  18. Expression of Hepatitis B virus surface antigen (HBsAg from genotypes A, D and F and influence of amino acid variations related or not to genotypes on HBsAg detection

    Directory of Open Access Journals (Sweden)

    Natalia M. Araujo

    Full Text Available The impact of hepatitis B virus (HBV genotypes on the sensitivity of surface antigen (HBsAg detection assays has been poorly investigated. Here, plasmids carrying consensus or variant coding sequences for HBV surface proteins from genotypes A, D and F, were constructed. HBsAg levels were evaluated in medium and extracts of transfected CHO cells by a commercial polyclonal-based assay. We show that HBsAg detection values of consensus forms from genotypes D and F were, respectively, 37% and 30% lower than those obtained by genotype A. However, the presence of two single variations, T143M in genotype A, and T125M in genotype D, produced a decrease of 44% and an increase of 34%, respectively, on HBsAg mean values in comparison with their consensus forms. In conclusion, HBsAg detection levels varied among HBV genotypes. However, unique amino acid substitutions not linked to genotypes, such as T125M and T143M described here, should have more implications in HBV immunological diagnostics than the set of variations characteristic of each HBV genotype.

  19. Simultaneous expression of growth hormone releasing hormone (GHRH) and hepatitis B surface antigen/somatostatin (HBsAg/SS) fusion genes in a construct in the skeletal muscle enhances rabbit weight gain.

    Science.gov (United States)

    Dai, Jian-wei; Liu, Song-cai; Hao, Lin-lin; Zhang, Yong-liang; Zhang, Qianqian; Ren, Xiao-hui; Jiang, Qing-yan

    2008-01-01

    Somatostatin (SS) and growth hormone-releasing hormone (GHRH) are synthesized and secreted by the hypothalamus, which can control the synthesis and secretion of the growth hormone (GH) from the hypophysis as well as regulate the GH concentrations in animals and humans. In this article, we describe the regulation of animal growth using plasmid DNA encoding both the GHRH gene and the SS gene fused with the hepatitis B surface antigen (HBsAg) gene. We constructed a series of expression plasmids to express the GHRH and HBsAg-SS fusion genes individually as well as collectively. The fusion gene and GHRH were successfully expressed in Chinese hamster ovary (CHO) cells, as proven by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblotting tests. Poly D, L-lactide-co-glycolic acid (PLGA) plasmid-encapsulating microspheres were prepared and injected intramuscularly into the leg skeletal muscles of rabbits. Weight gain/day and the levels of insulinlike growth factor-I (IGF-I), SS, and hepatitis B surface antibody (HBsAb) were monitored. During days 30 postinjection, increase in weight gain/day and IGF- I concentration and decrease in SS were observed in treatment groups. From days 15 to 30 postinjection, the weight gain/day significantly increased (P gain/day (P gain/day in rabbits.

  20. Long-term climate change: the evolution of shield surface boundary conditions

    International Nuclear Information System (INIS)

    Peltier, W.R.

    2007-01-01

    The Earths surface during the Pleistocene epoch has been repeatedly subjected to glacial cycles that have markedly influenced both the landscape and surface boundary conditions that, in part, governed past evolution of deep-seated Shield groundwater flow domains. As part of the Deep Geologic Repository Technology Programme simulations of the last Laurentide glacial episode have been undertaken with the University of Toronto Glacial System Model (GSM). The purpose of these simulations is to yield constrained predictions of the magnitude and time rate of change of peri-glacial, glacial and boreal regimes that have perturbed Shield flow domains in the geologic past. A detailed model of long timescale climate change has been developed, which is able to make useful predictions of the process of continental glaciation and deglaciation that has occurred in the past due to the small changes in the effective intensity of the Sun at the location of the Earth caused by gravitational many body effects in Solar System evolution. Based upon the success of this model we are able to assert that we have demonstrated a basic understanding of why this process has continually recurred in the past on a timescale of approximately 100 000 years. Continuing work with the Glacial Systems Model and efforts to provide explicit linkage to numerical analyses of sub-surface hydrology are beginning to yield a new understanding of groundwater flow system evolution and response to glacial perturbations. In so doing this understanding is not only providing a reasoned basis on which to examine issues of geosphere stability as relevant to the safety of a hypothetical repository for used nuclear fuel in Shield terrain, but is also offering an improved basis for the integrated interpretation of multi-disciplinary geo-scientific data necessary for development of a descriptive geosphere model that is seen as fundamental to the repository Safety Case. (author)

  1. CONSTRUCTION AND ANALYSIS OF LONG-TERM SURFACE TEMPERATURE DATASET IN FUJIAN PROVINCE

    Directory of Open Access Journals (Sweden)

    W. E. Li

    2017-09-01

    Full Text Available Land surface temperature (LST is a key parameter of land surface physical processes on global and regional scales, linking the heat fluxes and interactions between the ground and atmosphere. Based on MODIS 8-day LST products (MOD11A2 from the split-window algorithms, we constructed and obtained the monthly and annual LST dataset of Fujian Province from 2000 to 2015. Then, we analyzed the monthly and yearly time series LST data and further investigated the LST distribution and its evolution features. The average LST of Fujian Province reached the highest in July, while the lowest in January. The monthly and annual LST time series present a significantly periodic features (annual and interannual from 2000 to 2015. The spatial distribution showed that the LST in North and West was lower than South and East in Fujian Province. With the rapid development and urbanization of the coastal area in Fujian Province, the LST in coastal urban region was significantly higher than that in mountainous rural region. The LST distributions might affected by the climate, topography and land cover types. The spatio-temporal distribution characteristics of LST could provide good references for the agricultural layout and environment monitoring in Fujian Province.

  2. Short-term forecasting of thunderstorms at Kennedy Space Center, based on the surface wind field

    Science.gov (United States)

    Watson, Andrew I.; Lopez, Raul E.; Holle, Ronald L.; Daugherty, John R.; Ortiz, Robert

    1989-01-01

    Techniques incorporating wind convergence that can be used for the short-term prediction of thunderstorm development are described. With these techniques, the convergence signal is sensed by the wind network array 15 to 90 min before actual storm development. Particular attention is given to the convergence cell technique (which has been applied at the Kennedy Space Center) where each convective region is analyzed independently. It is noted that, while the monitoring of areal and cellular convergence can be used to help locate the seeds of developing thunderstorms and pinpoint the lightning threat areas, this forecasting aid cannot be used in isolation.

  3. Three-term Asymptotic Stress Field Expansion for Analysis of Surface Cracked Elbows in Nuclear Pressure Vessels

    Science.gov (United States)

    Labbe, Fernando

    2007-04-01

    Elbows with a shallow surface cracks in nuclear pressure pipes have been recognized as a major origin of potential catastrophic failures. Crack assessment is normally performed by using the J-integral approach. Although this one-parameter-based approach is useful to predict the ductile crack onset, it depends strongly on specimen geometry or constraint level. When a shallow crack exists (depth crack-to-thickness wall ratio less than 0.2) and/or a fully plastic condition develops around the crack, the J-integral alone does not describe completely the crack-tip stress field. In this paper, we report on the use of a three-term asymptotic expansion, referred to as the J- A 2 methodology, for modeling the elastic-plastic stress field around a three-dimensional shallow surface crack in an elbow subjected to internal pressure and out-of-plane bending. The material, an A 516 Gr. 70 steel, used in the nuclear industry, was modeled with a Ramberg-Osgood power law and flow theory of plasticity. A finite deformation theory was included to account for the highly nonlinear behavior around the crack tip. Numerical finite element results were used to calculate a second fracture parameter A 2 for the J- A 2 methodology. We found that the used three-term asymptotic expansion accurately describes the stress field around the considered three-dimensional shallow surface crack.

  4. Carcinoembryonic antigen (CEA)

    International Nuclear Information System (INIS)

    Ephraim, K.H.; Cox, P.H.; Hamer, C.J.A. v.d.; Berends, W.; Delhez, H.

    1977-01-01

    The carcinoembryonic antigen (CEA) is a complex of antigen determinants and also the carrier of these determinants. Chemically it is a glycoprotein. Its occurrence in blood serum or urine is correlated with malignant disease. Several radioimmunoassays (RIA) have been developed, one by Hoffmann-Laroche and one by the Rotterdam Radiotherapeutic Institute. Both methods and the Hoffmann assay kit are tested. Specifications are given for isolation of the antigen, preparation of the antiserum, and the execution of the RIA. Biochemical and clinical aspects are discussed

  5. Bacterial Ghosts as antigen and drug delivery system for ocular surface diseases: Effective internalization of Bacterial Ghosts by human conjunctival epithelial cells.

    Science.gov (United States)

    Kudela, Pavol; Koller, Verena Juliana; Mayr, Ulrike Beate; Nepp, Johannes; Lubitz, Werner; Barisani-Asenbauer, Talin

    2011-05-20

    The purpose of the presented investigation was to examine the efficiency of the novel carrier system Bacterial Ghosts (BGs), which are empty bacterial cell envelopes of Gram-negative bacteria to target human conjunctival epithelial cells, as well as to test the endocytic capacity of conjunctival cells after co-incubation with BGs generated from different bacterial species, and to foreclose potential cytotoxic effects caused by BGs. The efficiency of conjunctival cells to internalize BGs was investigated using the Chang conjunctival epithelial cell line and primary human conjunctiva-derived epithelial cells (HCDECs) as in vitro model. A high capacity of HCDECs to functionally internalize BGs was detected with the level of internalization depending on the type of species used for BGs generation. Detailed analysis showed no cytotoxic effect of BGs on HCDECs independently of the used bacterial species. Moreover, co-incubation with BGs did not enhance expression of both MHC class I and class II molecules by HCDECs, but increased expression of ICAM-1. The high rates of BG's internalization by HCDECs with no BG-mediated cytotoxic impact designate this carrier system to be a promising candidate for an ocular surface drug delivery system. BGs could be useful for future therapeutic ocular surface applications and eye-specific disease vaccine development including DNA transfer. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Targeted disruption of a ring-infected erythrocyte surface antigen (RESA)-like export protein gene in Plasmodium falciparum confers stable chondroitin 4-sulfate cytoadherence capacity

    DEFF Research Database (Denmark)

    Goel, Suchi; Muthusamy, Arivalagan; Miao, Jun

    2014-01-01

    . In this study, microarray transcriptome analysis showed that the absence of a gene cluster, comprising kahrp, pfemp3, and four other genes, results in the loss of parasitized erythrocytes adhering to chondroitin 4-sulfate (C4S). The role of one of these genes, PF3D7_0201600/PFB0080c, which encodes PHISTb...... (Plasmodium helical interspersed subtelomeric b) domain-containing RESA-like protein 1 expressed on the infected erythrocyte surface, was investigated. Disruption of PFB0080c resulted in increased var2csa transcription and VAR2CSA surface expression, leading to higher C4S-binding capacity of infected...... erythrocytes. Further, PFB0080c-knock-out parasites stably maintained the C4S adherence through many generations of growth. Although the majority of PFB0080c-knock-out parasites bound to C4S even after culturing for 6 months, a minor population bound to both C4S and CD36. These results strongly suggest...

  7. Long-term Impacts of Hurricane Wilma on Land Surface-Atmosphere Exchanges

    Science.gov (United States)

    Fuentes, J. D.; Dowell, K. K.; Engel, V. C.; Smith, T. J.

    2008-05-01

    In October 2005, Hurricane Wilma made landfall along the mangrove forests of western Everglades National Park, Florida, USA. Damage from the storm varied with distance from landfall and included widespread mortality and extensive defoliation. Large sediment deposition events were recorded in the interior marshes, with erosion taking place along the coastal margins. Wilma made landfall near a 30 m flux tower where eddy-covariance measurements of ecosystem-level carbon and energy fluxes started in 2003. Repairs to the structure were completed in 2006, enabling comparisons of surface fluxes before and after the storm. One year after the hurricane, both the average and daily integrated CO2 fluxes are consistently lower than the pre-storm values. The storm's impact on standing live biomass and the slow recovery of leaf area appear to have resulted in decreased photosynthetic uptake capacity. Nighttime respiratory CO2 fluxes above the canopy are unchanged from pre-storm values. During some periods, daily integrated fluxes show the forest as a net source of CO2 to the atmosphere. Soil CO2 fluxes are not measured directly, but daytime soil temperatures and vertical heat fluxes have shown consistently higher values after the storm. Nighttime soil temperatures values have been slightly lower. These stronger diurnal soil temperature fluctuations indicate enhanced radiative fluxes at the soil surface, possibly as a result of the reduced leaf area. The increases in daytime soil temperatures are presumably leading to higher below-ground respiration rates and, along with the reduced photosynthetic capacity, contributing to the lower net CO2 assimilation rates. This hypothesis is supported by nearby measurements of declining surface elevations of the organic soils which have been correlated with mangrove mortality in impacted areas. Both sensible and latent heat fluxes above the canopy are found to be reduced following the hurricane, and soil heat storage is higher. Together

  8. Long term change of diurnal cycle in surface air temperature over Tokyo metropolitan area

    Science.gov (United States)

    Hara, M.; Shimada, T.

    2017-12-01

    Tokyo Metropolitan area (i.e. southern part of Kanto district) is known for one of the hottest areas in summer in Japan. Especially in Saitama prefecture (north of Tokyo), the daily maximum surface air temperature (SAT) at screen height sometimes reached in 40 C. In the last decade, the summer heat environment in Japan is getting worse, and the number of emergency transportations due to heat stroke is rapidly increasing. In this study, we evaluate regional climate change due to some factors, such as land use / land cover changes. To evaluate the regional climate change, we performed analysis of observed data and a series of past climate simulations using the Weather Research and Forecasting (WRF) model with high horizontal resolution, including an urban canopy sub-model.

  9. New approach of long-term modification of Topas® to acquire surface hydrophilicity for chromosome spreading

    DEFF Research Database (Denmark)

    Mednova, Olga; Kwasny, Dorota; Rozlosnik, Noemi

    2014-01-01

    A modified and improved photografting procedure of Topas® surface hydrophilization is investigated in order to obtain stable modification of the polymer for long term storage. The achieved hydrophilicity and monitoring of the wettability during one month of storage are presented as well...... as a description of the optimal cleaning procedure and storage conditions to maintain the modified surface. Three minutes of oxygen plasma activation followed by 4 min of acrylic acid UV-photografting at 50 °C leads to the most stable hydrophilicity that was characterized by an initial water contact angle of 53.......5° ± 1.2°. Storage of the modified material in cold water at 4 °C and refraining from ultrasonic cleaning limit water contact angle increase to 5° over 30 days. In comparison with pristine hydrophobic Topas, the proposed treatment improves chromosome spreading ability significantly....

  10. Ikh Turgen Mountain Glacier Change and 3d Surface Extents Prediction Using Long Term Landsat Image and Climate Data

    Science.gov (United States)

    Nasanbat, Elbegjargal; Erdenebat, Erdenetogtokh; Chogsom, Bolorchuluun; Lkhamjav, Ochirkhuyag; Nanzad, Lkhagvadorj

    2018-04-01

    The glacier is most important the freshwater resources and indicator of the climate change. The researchers noted that during last decades the glacier is melting due to global warming. The study calculates a spatial distribution of protentional change of glacier coverage in the Ikh Turgen mountain of Western Mongolia, and it integrates long-term climate data and satellite datasets. Therefore, in this experiment has tried to estimation three-dimensional surface area of the glacier. For this purpose, Normalized difference snow index (NDSI) was applied to decision tree approach, using Landsat MSS, TM, ETM+ and LC8 imagery for 1975-2016, a surface and slope for digital elevation model, precipitation and air temperature historical data of meteorological station. The potential volume area significantly changed glacier cover of the Ikh Turgen Mountain, and the area affected by highly variable precipitation and air temperature regimes. Between 1972 and 2016, a potential area of glacier area has been decreased in Ikh Turgen mountain region.

  11. Genomic Methylation Inhibits Expression of Hepatitis B Virus Envelope Protein in Transgenic Mice: A Non-Infectious Mouse Model to Study Silencing of HBV Surface Antigen Genes.

    Science.gov (United States)

    Graumann, Franziska; Churin, Yuri; Tschuschner, Annette; Reifenberg, Kurt; Glebe, Dieter; Roderfeld, Martin; Roeb, Elke

    2015-01-01

    The Hepatitis B virus genome persists in the nucleus of virus infected hepatocytes where it serves as template for viral mRNA synthesis. Epigenetic modifications, including methylation of the CpG islands contribute to the regulation of viral gene expression. The present study investigates the effects of spontaneous age dependent loss of hepatitis B surface protein- (HBs) expression due to HBV-genome specific methylation as well as its proximate positive effects in HBs transgenic mice. Liver and serum of HBs transgenic mice aged 5-33 weeks were analyzed by Western blot, immunohistochemistry, serum analysis, PCR, and qRT-PCR. From the third month of age hepatic loss of HBs was observed in 20% of transgenic mice. The size of HBs-free area and the relative number of animals with these effects increased with age and struck about 55% of animals aged 33 weeks. Loss of HBs-expression was strongly correlated with amelioration of serum parameters ALT and AST. In addition lower HBs-expression went on with decreased ER-stress. The loss of surface protein expression started on transcriptional level and appeared to be regulated epigenetically by DNA methylation. The amount of the HBs-expression correlated negatively with methylation of HBV DNA in the mouse genome. Our data suggest that methylation of specific CpG sites controls gene expression even in HBs-transgenic mice with truncated HBV genome. More important, the loss of HBs expression and intracellular aggregation ameliorated cell stress and liver integrity. Thus, targeted modulation of HBs expression may offer new therapeutic approaches. Furthermore, HBs-transgenic mice depict a non-infectious mouse model to study one possible mechanism of HBs gene silencing by hypermethylation.

  12. Analysis of hepatitis B surface antigen (HBsAg) using high-sensitivity HBsAg assays in hepatitis B virus carriers in whom HBsAg seroclearance was confirmed by conventional assays.

    Science.gov (United States)

    Ozeki, Itaru; Nakajima, Tomoaki; Suii, Hirokazu; Tatsumi, Ryoji; Yamaguchi, Masakatsu; Kimura, Mutsuumi; Arakawa, Tomohiro; Kuwata, Yasuaki; Ohmura, Takumi; Hige, Shuhei; Karino, Yoshiyasu; Toyota, Joji

    2018-02-01

    We investigated the utility of high-sensitivity hepatitis B surface antigen (HBsAg) assays compared with conventional HBsAg assays. Using serum samples from 114 hepatitis B virus (HBV) carriers in whom HBsAg seroclearance was confirmed by conventional HBsAg assays (cut-off value, 0.05 IU/mL), the amount of HBsAg was re-examined by high-sensitivity HBsAg assays (cut-off value, 0.005 IU/mL). Cases negative for HBsAg in both assays were defined as consistent cases, and cases positive for HBsAg in the high-sensitivity HBsAg assay only were defined as discrepant cases. There were 55 (48.2%) discrepant cases, and the range of HBsAg titers determined by high-sensitivity HBsAg assays was 0.005-0.056 IU/mL. Multivariate analysis showed that the presence of nucleos(t)ide analog therapy, liver cirrhosis, and negative anti-HBs contributed to the discrepancies between the two assays. Cumulative anti-HBs positivity rates among discrepant cases were 12.7%, 17.2%, 38.8%, and 43.9% at baseline, 1 year, 3 years, and 5 years, respectively, whereas the corresponding rates among consistent cases were 50.8%, 56.0%, 61.7%, and 68.0%, respectively. Hepatitis B virus DNA negativity rates were 56.4% and 81.4% at baseline, 51.3% and 83.3% at 1 year, and 36.8% and 95.7% at 3 years, among discrepant and consistent cases, respectively. Hepatitis B surface antigen reversion was observed only in discrepant cases. Re-examination by high-sensitivity HBsAg assays revealed that HBsAg was positive in approximately 50% of cases. Cumulative anti-HBs seroconversion rates and HBV-DNA seroclearance rates were lower in these cases, suggesting a population at risk for HBsAg reversion. © 2017 The Japan Society of Hepatology.

  13. Long term, non-anthropogenic groundwater storage changes simulated by a global land surface model

    Science.gov (United States)

    Li, B.; Rodell, M.; Sheffield, J.; Wood, E. F.

    2017-12-01

    Groundwater is crucial for meeting agricultural, industrial and municipal water needs, especially in arid, semi-arid and drought impacted regions. Yet, knowledge on groundwater response to climate variability is not well understood due to lack of systematic and continuous in situ measurements. In this study, we investigate global non-anthropogenic groundwater storage variations with a land surface model driven by a 67-year (1948-204) meteorological forcing data set. Model estimates were evaluated using in situ groundwater data from the central and northeastern U.S. and terrestrial water storage derived from the Gravity Recovery and Climate Experiment (GRACE) satellites and found to be reasonable. Empirical orthogonal function (EOF) analysis was employed to examine modes of variability of groundwater storage and their relationship with atmospheric effects such as precipitation and evapotranspiration. The result shows that the leading mode in global groundwater storage reflects the influence of the El Niño Southern Oscillation (ENSO). Consistent with the EOF analysis, global total groundwater storage reflected the low frequency variability of ENSO and decreased significantly over 1948-2014 while global ET and precipitation did not exhibit statistically significant trends. This study suggests that while precipitation and ET are the primary drivers of climate related groundwater variability, changes in other forcing fields than precipitation and temperature are also important because of their influence on ET. We discuss the need to improve model physics and to continuously validate model estimates and forcing data for future studies.

  14. Decomposing Shortwave Top-of-Atmosphere Radiative Flux Variability in Terms of Surface and Atmospheric Contributions Using CERES Observations

    Science.gov (United States)

    Loeb, N. G.; Wong, T.; Wang, H.

    2017-12-01

    Earth's climate is determined by the exchange of radiant energy between the Sun, Earth and space. The absorbed solar radiation (ASR) fuels the climate system, providing the energy required for atmospheric and oceanic motions, while the system cools by emitting outgoing longwave (LW) radiation to space. A central objective of the Clouds and the Earth's Radiant Energy System (CERES) is to produce a long-term global climate data record of Earth's radiation budget along with the associated atmospheric and surface properties that influence it. CERES data products utilize a number of data sources, including broadband radiometers measuring incoming and reflected solar radiation and OLR, polar orbiting and geostationary spectral imagers, meteorological, aerosol and ozone assimilation data, and snow/sea-ice maps based on microwave radiometer data. Here we use simple diagnostic model of Earth's albedo and CERES Energy Balanced and Filled (EBAF) Ed4.0 data for March 2000-February 2016 to quantify interannual variations in SW TOA flux associated with surface albedo and atmospheric reflectance and transmittance variations. Surface albedo variations account for <0.5% of the total SW TOA flux variance over the tropics and 4% globally. Variations in atmospheric reflectance and transmittance account for virtually all of the total SW TOA flux variance over the tropics and only 81% globally. The remaining 15% of the global SW TOA flux variance is explained by the co-variance of surface albedo and atmospheric reflectance/transmittance. Equatorward of 60-degree latitude, the atmospheric contribution exceeds that of the surface by at least an order-of-magnitude. In contrast, the surface and atmospheric variations contribute equally poleward of 60S and surface variations account for twice as much as the atmosphere poleward of 60N. However, as much as 40% of the total SW TOA flux variance poleward of 60N is explained by the covariance of surface albedo and atmospheric reflectance

  15. The prevalence of hepatitis B virus E antigen among Ghanaian ...

    African Journals Online (AJOL)

    We studied the prevalence of hepatitis B virus 'e' antigen (HBeAg) among individuals determined to be hepatitis B virus (HBV) surface antigen- positive and analyzed the gender/age category associated with more active HBV infection and whether alteration in the levels of alanine aminotransferase could be associated with ...

  16. Comparison of bovine lymphocyte antigen DRB3.2 allele ...

    African Journals Online (AJOL)

    The bovine lymphocyte antigen (BoLA-DRB3) gene encodes cell surface glycoproteins that initiate immune responses by presenting processed antigenic peptides to CD4 T helper cells. DRB3 is the most polymorphic bovine MHC class II gene which encodes the peptide-binding groove. Since different alleles favor the ...

  17. The Neck Region of the C-type Lectin DC-SIGN Regulates Its Surface Spatiotemporal Organization and Virus-binding Capacity on Antigen-presenting Cells*

    Science.gov (United States)

    Manzo, Carlo; Torreno-Pina, Juan A.; Joosten, Ben; Reinieren-Beeren, Inge; Gualda, Emilio J.; Loza-Alvarez, Pablo; Figdor, Carl G.; Garcia-Parajo, Maria F.; Cambi, Alessandra

    2012-01-01

    The C-type lectin DC-SIGN expressed on dendritic cells (DCs) facilitates capture and internalization of a plethora of different pathogens. Although it is known that DC-SIGN organizes in nanoclusters at the surface of DCs, the molecular mechanisms responsible for this well defined nanopatterning and role in viral binding remain enigmatic. By combining biochemical and advanced biophysical techniques, including optical superresolution and single particle tracking, we demonstrate that DC-SIGN intrinsic nanoclustering strictly depends on its molecular structure. DC-SIGN nanoclusters exhibited free, Brownian diffusion on the cell membrane. Truncation of the extracellular neck region, known to abrogate tetramerization, significantly reduced nanoclustering and concomitantly increased lateral diffusion. Importantly, DC-SIGN nanocluster dissolution exclusively compromised binding to nanoscale size pathogens. Monte Carlo simulations revealed that heterogeneity on nanocluster density and spatial distribution confers broader binding capabilities to DC-SIGN. As such, our results underscore a direct relationship between spatial nanopatterning, driven by intermolecular interactions between the neck regions, and receptor diffusion to provide DC-SIGN with the exquisite ability to dock pathogens at the virus length scale. Insight into how virus receptors are organized prior to virus binding and how they assemble into functional platforms for virus docking is helpful to develop novel strategies to prevent virus entry and infection. PMID:23019323

  18. Antigenic differences within the Cryptosporidium hominis and Cryptosporidium parvum surface proteins P23 and GP900 defined by monoclonal antibody reactivity.

    Science.gov (United States)

    Sturbaum, Gregory D; Schaefer, Deborah A; Jost, B Helen; Sterling, Charles R; Riggs, Michael W

    2008-06-01

    The biological basis for the specificity of host infectivity patterns of Cryptosporidium spp., in particular C. hominis and C. parvum, has yet to be fully elucidated. Comparison of the C. parvum and C. hominis P23 and GP900 predicted amino acid sequences revealed 3 differences in P23 and 4 and 17 differences in GP900 domains 1 and 5, respectively. Using monoclonal antibodies developed against the surface (glyco)proteins P23 and GP900 of the C. parvum Iowa isolate, solubilized glycoprotein from three C. hominis isolates was screened for reactivity using Western immunoblots. One of ten P23 MAbs and three of 21 GP900 MAbs were not reactive with any of the three C. hominis isolates. The non-reactive P23 MAb binds to a peptide epitope, while the non-reactive GP900 MAbs bind to either carbohydrate/carbohydrate-dependent or peptide epitopes of C. parvum. These results demonstrate phenotypic differences between C. hominis and C. parvum within two (glyco)proteins that are involved in parasite gliding motility and attachment/invasion.

  19. Long-Term Drainage from the Riprap Side Slope of a Surface Barrier

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhuanfang

    2017-07-01

    Surface barriers designed to isolate underground nuclear waste in place are expected to function for at least 1000 years. To achieve this long design life, such barriers need to be protected with side slopes against wind- and water-induced erosion and damage by natural or human activities. However, the side slopes are usually constructed with materials coarser than the barrier. Their hydrological characteristics must be understood so that any drainage from them is considered in the barrier design and will not compromise the barrier function. The Prototype Hanford Barrier, an evapotranspiration-capillary (ETC) barrier, was constructed in 1994 at the Hanford Site in southeastern Washington state, with a gravel side slope and a riprap side slope. The soil water content in the gravel side slope and drainage from both side slopes have been monitored since the completion of construction. The monitoring results show that under natural precipitation the annual drainage rates from the two types of side slopes were very similar and about 5 times the typical recharge from local soil with natural vegetation and 40 times the barrier design criterion. The higher recharge from the side slopes results in some of the drainage migrating laterally to the region beneath the ETC barrier. This edge effect of the enhanced drainage was evaluated for a period of 1000 years by numerical simulation. The edge effect was quantified by the amount of water across the barrier edges and the affecting distance of the barrier edges. These results indicate that design features can be adjusted to reduce the edge effect when necessary.

  20. Long term analysis of the columnar and surface aerosol relationship at an urban European coastal site

    Science.gov (United States)

    Segura, S.; Estellés, V.; Utrillas, M. P.; Martínez-Lozano, J. A.

    2017-10-01

    Simultaneous PM2.5, PM10 and columnar (ground and satellite based) AOD measurements have been analyzed at Burjassot site in the metropolitan area of Valencia (Spain) during the period 2007-2016. The site is representative of a south European city in the Western Mediterranean coastal area, influenced by local urban pollution but also from frequent Saharan dust events. First, multiannual statistics were performed to characterize the main aerosol burden characteristics. The averages and standard deviations resulted 18 ± 9 μg m-3, 25 ± 19 μg m-3, 0.15 ± 0.11, 0.23 ± 0.17, 0.19 ± 0.15 and 1.2 ± 0.3 for PM2.5, PM10, AERONET AOD, MODIS Terra AOD, MODIS Aqua AOD, and AERONET Ångström exponent AE, respectively. The AOD is always referred to 550 nm. PM10 and AOD showed seasonal patterns with maxima in summer and minima in winter. However, PM2.5 and AE did not show such an evident seasonality. The relationship between surface and columnar measurements show a poor correlation (r down to 0.30) for daily values, although the correlation increases to r up to 0.90 for yearly averages. The relationship between PM and AOD becomes more consistent when the databases are binned in intervals of 0.05 AOD. Results for AERONET and MODIS AOD are very similar, although for daily averages is slightly worse for satellite than ground based measurements. In order to explain some seasonality effects found, the mixing layer height has been included in the analysis. Results show that the correlation is maximum when PM2.5 is used and the mixing layer height is greater than 1 000 m (r > 0.90).

  1. Results of the "Komplast" experiment on the long-term exposure of materials specimens on the ISS surface

    Science.gov (United States)

    Shumov, Andrey; Novikov, Lev

    The "Komplast" materials experiment was designed by the Khrunichev State Research and Production Space Center together with Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University and other Russian scientific institutes, and has been carried out since 1998. The aim of the experiment is to study the complex effects of space factors on specimens of various materials. Eight “Komplast” panels fitted with material specimens equipped UV-sensors and temperature sensors were located on the International Space Station (ISS) Functional Cargo Block (FGB) module exterior surface. The panels were sent into orbit with the FGB when it launched on November 20, 1998. Two of these panels were subsequently returned to Earth by Space Shuttle Discovery after 12 years of LEO exposure. The uniqueness of the "Komplast" experiment determined by long duration of open space exposure, which is much longer than in other similar experiments. For example LDEF: 1984-1990, HEEI (Space Station "Mir"): 1996-1997, MISSE-1, -2 (ISS): 1,5-2 years. In this work reveals laboratory research results of some materials specimens, which had been exposed on “Komplast” panels. A distinctive feature of this research was additional irradiation of specimens by atomic oxygen and electrons with energies of ~ 1-8 MeV in laboratory. In the interpretation of the experiment results was taken into account the specimens exposure temperature conditions on the ISS exterior surface and the conditions of their sunlit, defined by the above-mentioned sensors readings. Lot of attention was paid to the investigation of rubber materials specimens. The deformation, mechanical and relaxation characteristics were defined for the specimens. Also were investigations the seals-ability of model rubber seals after the long-term outer exposure. It was determined conservation volumetric deformation and relaxation characteristics of the exposed specimens and the localization of structural changes in the thin

  2. Construction of a humanized antibody to hepatitis B surface antigen by specificity-determining residues (SDR)-grafting and de-immunization.

    Science.gov (United States)

    Kim, Keun-Soo; Kim, Hyun-Jung; Han, Byung Woo; Myung, Pyung-Keun; Hong, Hyo Jeong

    2010-05-28

    We previously constructed a humanized antibody, HuS10, by grafting the complementarity-determining regions (CDRs) of a parental murine monoclonal antibody into the homologous human antibody sequences. This process is termed CDR grafting. Some residues that were thought to affect the CDR loops and stabilize the structure of the variable regions were retained in the framework region. HuS10 exhibited in vivo virus-neutralizing activity, but its murine content had the potential to elicit immune responses in patients. In this study, to minimize the immunogenic potential of HuS10, we replaced 17 mouse residues in HuS10 with the comparable human residues using specificity-determining residue (SDR)-grafting and de-immunization methods. The resultant humanized antibody, HzS-III, had the same affinity and epitope specificity as HuS10 and had reduced immunogenic potential, as assessed by T-cell epitope analysis. Thus, SDR grafting in combination with de-immunization may be a useful strategy for minimizing the immunogenicity of humanized antibodies. In addition, HzS-III may be a good candidate for immunoprophylaxis of HBV infection. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  3. MEASUREMENT OF AFFINITY IN SERUM SAMPLES OF ANTIGEN-FREE, GERM-FREE AND CONVENTIONAL MICE AFTER HYPERIMMUNIZATION WITH 2,4-DINITROPHENYL KEYHOLE LIMPET HEMOCYANIN, USING SURFACE-PLASMON RESONANCE

    NARCIS (Netherlands)

    BAKKER, R; LASONDER, E; BOS, NA

    We previously investigated the primary and secondary responses and hyperimmunization to the T cell-dependent antigen 2,4-dinitrophenyl keyhole limpet hemocyanin (DNP-KLH) in antigen-free (AF), germ-free (GF) and conventional (CV) mice. Both the absolute and relative numbers of DNP-specific

  4. Risk Factors for Hepatitis B virus Surface Antigen Positive Prevalence in the Most Migratory Province of Iran: A Matched Case- Control Study

    Directory of Open Access Journals (Sweden)

    Gh. Karimi

    2015-02-01

    Full Text Available Background and Objective: Hepatitis B Virus Infection is one of the most common infectious diseases and also among the world's top ten causes of this group diseases-related mortality, so that 500,000 to 1.2 million annually die due to the consequences of this infection such as chronic hepatitis, cirrhosis and hepatocellular carcinoma. This study was conducted to determine risk factors for HBsAg-positive prevalence in Alborz Province. Materials and Methods: A 1:1 matched case-control study, 213 of cases reported HBsAg positive to the Alborz University of Medical Sciences in 2013 as case group with 213 of family members of patients with hepatitis C who have serologic markers Anti- HCV negative and HBsAg negative as the control group, were compared in terms of demographic characteristics, History of high risk behaviors, Iatrogenic exposures, community exposures and history of liver disease. Statistical analysis using logistic regression was performed by SPSS software version 18. Results: Reported cases with a mean age of 37.6±15.5 years, was more relevant to marginalized, immigrants and male gender. Nationality, being married, low level of education, family history of HBsAg positive, history of non-intravenous drug abuse, alcohol consumption, history of prison, employment in high risk occupations, sharing of razor, injuries with contaminated sharp instruments and history of jaundice in mother were found to be independent risk factors for HBsAg positive prevalence (OR: 0.27, 3.61, 1.68, 18.04, 12.21, 2.9, 7.52, 2.47, 5.55, 21.48, 11.3, respectively. Conclusions: Unfavorable situation of the marginalized and the prisoners, imported illegal immigrants, especially Afghans can be extended to high-risk behaviors and the threat of a disease surveillance system. Screening and vaccination aforementioned groups, health promotion of the marginalized and raise public knowledge is necessary.

  5. Long-term changes in net radiation and its components above a pine forest and a grass surface in Germany

    International Nuclear Information System (INIS)

    Long-term measurements (1974–1993 and 1996, respectively) of the net radiation (Q), global radiation (G), reflected global radiation (R), long-wave atmospheric radiation (A) and thermal radiation (E) of a pine forest in Southern Germany (index p) and of a grass surface in Northern Germany (index g) are compared. The influence of changes in surface properties is discussed. There are, in the case of the pine stand, forest growth and forest management and in the case of the grass surface, the shifting of the site from a climatic garden to a horizontal roof. Both series of radiant fluxes are analyzed with respect to the influences of the weather (cloudiness, heat advection). To eliminate the different influence of the solar radiation of the two sites, it is necessary to normalize by means of the global radiation G, yielding the radiation efficiency Q/G, the albedo R/G=α and the normalized long-wave net radiation (A+E)/G. Furthermore, the long-term mean values and the long-term trend of yearly mean values are discussed and, moreover, a comparison is made of individual monthly values. Q p is twice as large as Q g . The reason for this is the higher values of G and A above the pine forest and half values of α p compared to α g . E p is only a little greater than E g . The time series of the radiation fluxes show the following trends: Q p declines continuously despite a slight increase of G p . This is mainly due to the long-wave radiation fluxes. The net radiation of the grass surface Q g shows noticeably lower values after the merging of the site. This phenomenon is also dominated by the long-wave radiation processes. Although the properties of both site surfaces alter, E p and E g remain relatively stable. A p and A g show a remarkable decrease however. The reason for this is to be found in a modification of the heat advection, showing a more pronounced impact on the more continentally exposed site (pine forest). Compared to α g , α p shows only a small

  6. Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

    Directory of Open Access Journals (Sweden)

    Anne Endmann

    Full Text Available Currently marketed vaccines against hepatitis B virus (HBV based on the small (S hepatitis B surface antigen (HBsAg fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

  7. Improved humoral and cellular immune response against the gp120 V3 loop of HIV-1 following genetic immunization with a chimeric DNA vaccine encoding the V3 inserted into the hepatites B surface antigen

    DEFF Research Database (Denmark)

    Fomsgaard, A.; Nielsen, H.V.; Bryder, K.

    1998-01-01

    -2d-restricted cytotoxic T lymphocyte (CTL) epitope. In an attempt to improve the immunogenicity of V3 in DNA vaccines, a plasmid expressing MN V3 as a fusion protein with the highly immunogenic middle (pre-S2+S) surface antigen of hepatitis B virus (HBsAg) was constructed. Epidermal inoculation...... by gene gun was used for genetic immunization in a mouse model. Antibody and CTL responses to MN V3 and HBsAg were measured and compared with the immune responses obtained after vaccination with plasmids encoding the complete HIV-1 MN gp160 and HBsAg (pre-S2+S), respectively. DNA vaccination with the HIV...... MN gp160 envelope plasmid induced a slow and low titred anti-MN V3 antibody response at 12 weeks post-inoculation (p.i.) and a late appearing (7 weeks), weak and variable CTL response. In contrast, DNA vaccination with the HBsAg-encoding plasmid induced a rapid and high titred anti-HBsAg antibody...

  8. Antigen processing and remodeling of the endosomal pathway: requirements for antigen cross-presentation.

    Directory of Open Access Journals (Sweden)

    Ewoud Bernardus Compeer

    2012-03-01

    Full Text Available The cross-presentation of endocytosed antigen as peptide/class I MHC complexes plays a central role in the elicitation of CD8+ T cell clones that mediate anti-viral and anti-tumor immune responses. While it has been clear that there are specific subsets of professional antigen presenting cells (APC capable of antigen cross-presentation, description of mechanisms involved is still ongoing. Especially amongst dendritic cells (DC, there are specialized subsets that are highly proficient at antigen cross-presentation. We here present a focused survey on the cell biological processes in the endosomal pathway that support antigen cross-presentation. This review highlight DC-intrinsic mechanisms that facilitate the cross-presentation of endocytosed antigen, including receptor-mediated uptake, recycling and maturation including the sorting of membrane proteins, dynamic remodeling of endosomal structures and cell-surface directed endosomal trafficking. We will conclude with description of pathogen-induced deviation of endosomal processing, and discuss how immune evasion strategies pertaining endosomal trafficking may preclude antigen cross-presentation.

  9. Effect of soil erosion on the long-term stability of FUSRAP near-surface waste-burial sites

    Energy Technology Data Exchange (ETDEWEB)

    Knight, M.J.

    1983-04-01

    Decontamination of FUSRAP sites could result in the generation of large volumes (in excess of 400,000 m/sup 3/) of low-activity radioactive wastes (primarily contaminated soil and building materials) requiring subsequent disposal. It is likely that near-surface burial will be seriously considered as an option for disposal of these materials. A number of factors - including soil erosion - could adversely affect the long-term stability of a near-surface waste-burial site. The majority of FUSRAP sites are located in the humid eastern United States, where the principal cause of erosion is the action of water. This report examines the effect of soil erosion by water on burial-site stability based on analysis of four hypothetical near-surface burial sites. The Universal Soil Loss Equation was employed to estimate average annual soil loss from burial sites and the 1000-year effects of soil loss on the soil barrier (burial trench cap) placed over low-activity wastes. Results suggest that the land use of the burial site and the slope gradient of the burial trench cap significantly affect the rate of soil erosion. The development of measures limiting the potential land use of a burial site (e.g., mixing large rocks into the burial trench cap) may be required to preserve the integrity of a burial trench for long periods of time.

  10. Effect of soil erosion on the long-term stability of FUSRAP near-surface waste-burial sites

    International Nuclear Information System (INIS)

    Knight, M.J.

    1983-04-01

    Decontamination of FUSRAP sites could result in the generation of large volumes (in excess of 400,000 m 3 ) of low-activity radioactive wastes (primarily contaminated soil and building materials) requiring subsequent disposal. It is likely that near-surface burial will be seriously considered as an option for disposal of these materials. A number of factors - including soil erosion - could adversely affect the long-term stability of a near-surface waste-burial site. The majority of FUSRAP sites are located in the humid eastern United States, where the principal cause of erosion is the action of water. This report examines the effect of soil erosion by water on burial-site stability based on analysis of four hypothetical near-surface burial sites. The Universal Soil Loss Equation was employed to estimate average annual soil loss from burial sites and the 1000-year effects of soil loss on the soil barrier (burial trench cap) placed over low-activity wastes. Results suggest that the land use of the burial site and the slope gradient of the burial trench cap significantly affect the rate of soil erosion. The development of measures limiting the potential land use of a burial site (e.g., mixing large rocks into the burial trench cap) may be required to preserve the integrity of a burial trench for long periods of time

  11. Hepatitis B virus surface antigen (HBsAg)-positive and HBsAg-negative hepatitis B virus infection among mother-teenager pairs 13 years after neonatal hepatitis B virus vaccination.

    Science.gov (United States)

    Yao, Qing-Qing; Dong, Xiao-Lian; Wang, Xue-Cai; Ge, Sheng-Xiang; Hu, An-Qun; Liu, Hai-Yan; Wang, Yueping Alex; Yuan, Quan; Zheng, Ying-Jie

    2013-02-01

    It is unclear whether a mother who is negative for hepatitis B virus surface antigen (HBsAg) but positive for hepatitis B virus (HBV) is at potential risk for mother-to-child transmission of HBV. This study, using a paired mother-teenager population, aimed to assess whether maternal HBsAg-negative HBV infection ((hn)HBI) is a significant source of child HBV infection (HBI). A follow-up study with blood collection has been conducted on the 93 mother-teenager pairs from the initial 135 pregnant woman-newborn pairs 13 years after neonatal HBV vaccination. Serological and viral markers of HBV have been tested, and phylogenetic analysis of HBV isolates has been done. The HBI prevalence was 1.9% (1 (hn)HBI/53) for teenage children of non-HBI mothers, compared with 16.7% (1 (hn)HBI/6) for those of (hn)HBI mothers and 2.9% (1 HBsAg-positive HBV infection [(hp)HBI]/34) for those of (hp)HBI mothers. Similar viral sequences have been found in one pair of whom both the mother and teenager have had (hn)HBI. In comparison with the (hp)HBI cases, those with (hn)HBI had a lower level of HBV load and a higher proportion of genotype-C strains, which were accompanied by differentiated mutations (Q129R, K141E, and Y161N) of the "a" determinant of the HBV surface gene. Our findings suggest that mother-to-teenager transmission of (hn)HBI can occur among those in the neonatal HBV vaccination program.

  12. Differential Growth of Francisella tularensis, Which Alters Expression of Virulence Factors, Dominant Antigens, and Surface-Carbohydrate Synthases, Governs the Apparent Virulence of Ft SchuS4 to Immunized Animals

    Directory of Open Access Journals (Sweden)

    Kristen M. Holland

    2017-06-01

    Full Text Available The gram-negative bacterium Francisella tularensis (Ft is both a potential biological weapon and a naturally occurring microbe that survives in arthropods, fresh water amoeba, and mammals with distinct phenotypes in various environments. Previously, we used a number of measurements to characterize Ft grown in Brain-Heart Infusion (BHI broth as (1 more similar to infection-derived bacteria, and (2 slightly more virulent in naïve animals, compared to Ft grown in Mueller Hinton Broth (MHB. In these studies we observed that the free amino acids in MHB repress expression of select Ft virulence factors by an unknown mechanism. Here, we tested the hypotheses that Ft grown in BHI (BHI-Ft accurately displays a full protein composition more similar to that reported for infection-derived Ft and that this similarity would make BHI-Ft more susceptible to pre-existing, vaccine-induced immunity than MHB-Ft. We performed comprehensive proteomic analysis of Ft grown in MHB, BHI, and BHI supplemented with casamino acids (BCA and compared our findings to published “omics” data derived from Ft grown in vivo. Based on the abundance of ~1,000 proteins, the fingerprint of BHI-Ft is one of nutrient-deprived bacteria that—through induction of a stringent-starvation-like response—have induced the FevR regulon for expression of the bacterium's virulence factors, immuno-dominant antigens, and surface-carbohydrate synthases. To test the notion that increased abundance of dominant antigens expressed by BHI-Ft would render these bacteria more susceptible to pre-existing, vaccine-induced immunity, we employed a battery of LVS-vaccination and S4-challenge protocols using MHB- and BHI-grown Ft S4. Contrary to our hypothesis, these experiments reveal that LVS-immunization provides a barrier to infection that is significantly more effective against an MHB-S4 challenge than a BHI-S4 challenge. The differences in apparent virulence to immunized mice are profoundly greater

  13. Enhanced detection sensitivity of prostate-specific antigen via PSA-conjugated gold nanoparticles based on localized surface plasmon resonance: GNP-coated anti-PSA/LSPR as a novel approach for the identification of prostate anomalies.

    Science.gov (United States)

    Jazayeri, M H; Amani, H; Pourfatollah, A A; Avan, A; Ferns, G A; Pazoki-Toroudi, H

    2016-10-01

    Prostate-specific antigen (PSA) is used to screen for prostate disease, although it has several limitations in its application as an organ-specific or cancer-specific marker. Furthermore, a highly specific/sensitive and/or label-free identification of PSA still remains a challenge in the diagnosis of prostate anomalies. We aimed to develop a gold nanoparticle (GNP)-conjugated anti-PSA antibody-based localized surface plasmon resonance (LSPR) as a novel approach to detect prostatic disease. A total of 25 nm colloidal gold particles were prepared followed by conjugation with anti-PSA pAb (GNPs-PSA pAb). LSPR was used to monitor the absorption changes of the aggregation of the particles. The size, shape and stability of the GNP-anti-PSA were evaluated by dynamic light scattering transmission electron microscopy (TEM) and zetasizer. The GNPs-conjugated PSA-pAb was successfully synthesized and subsequently characterized using ultraviolet absorption spectroscopy and TEM to determine the size distribution, crystallinity and stability of the particles (for example, stability of GNP: 443 mV). To increase the stability of the particles, we pegylated GNPs using an N-(3-dimethylaminopropyl)-N*-ethylcarbodiimide hydrochloride (EDC)/N-hydroxylsuccinimide (NHS) linker (for example, stability of GNP after pegylation: 272 mV). We found a significant increase in the absorbance and intensity of the particles with extinction peak at 545/2 nm, which was shifted by ~1 nm after conjugation. To illustrate the potential of the GNPs-PSA pAb to bind specifically to PSA, LSPR was used. We found that the extinction peak shifted 3 nm for a solution of 100 nM unlabeled antigen. In summary, we have established a novel approach for improving the efficacy/sensitivity of PSA in the assessment of prostate disease, supporting further investigation on the diagnostic value of GNP-conjugated anti-PSA/LSPR for the detection of prostate cancer.

  14. The expansion ability but not the quality of HIV-specific CD8(+) T cells is associated with protective human leucocyte antigen class I alleles in long-term non-progressors.

    Science.gov (United States)

    López, Mariola; Peris, Alejandra; Soriano, Vincent; Lozano, Sara; Vicario, José Luis; Rallón, Norma I; Restrepo, Clara; Benito, José M

    2011-11-01

    Studies in long-term non-progressors (LTNP) have suggested that the quality of the CD8(+) response may involve protective human leucocyte antigen (HLA) class I alleles. However, studies examining the expansion ability of different functional CD8(+) T cells and their association with HLA class I alleles are lacking. LTNP, untreated typical progressors (TP) and patients successfully on highly active retroviral therapy (HAART) during 1 year (HP) were included. HLA class I typing was performed using a sequence-specific primer assay. Functional subsets of Gag- and Nef-specific CD8(+) cells were analysed based on the production of macrophage inflammatory protein (MIP)-1β, tumour necrosis factor (TNF)-α and interleukin (IL)-2. Their expansion abilities were evaluated after 10-day culture in the presence of Gag and Nef human immunodeficiency virus (HIV) peptides. No differences were seen when comparing quantitative and qualitative HIV-specific CD8(+) T cell responses according to the presence/absence of protective HLA alleles (B*58 and B*27 supertypes) in each group. However, LTNP with protective HLA alleles showed a higher expansion ability of Gag-specific MIP(+) TNF(+) IL-2(+) T cells and Nef-specific MIP(+) TNF(+) IL-2(+) . HLA-B*5701+LTNP displayed a higher expansion ability of Gag and Nef-specific MIP(+) TNF(-) IL-2(+) T cells than HLA-B*5701-LTNP. This was not so for HLA-B*2705. No differences were seen in the expansion ability according to the presence/absence of protective HLA alleles in TP and HP. The expansion ability of polyfunctional CD8(+) T cells is modulated by HLA class I alleles and targeted protein. LTNP with HLA class I protective alleles (mainly B*5701) display better expansion ability of polyfunctional HIV-specific CD8(+) T cells than the rest, suggesting that factors other than HLA-B*5701 must contribute to the control of viral replication in other LTNP. Furthermore, these attributes of HIV-specific CD8(+) T are not restored by HAART; thus, adjuvant

  15. Effect of radiation on the expression of tumor-associated antigens of human lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Hareyama, Masato

    1988-01-01

    We studied the effects of irradiation on the expression of a tumor-associated antigen (YH206 antigen) of cultured human lung adenocarcinoma A549 cells by using enzyme-linked immunosorbent assay (ELISA) and flow cytometry. YH206 antigen is preferentially expressed on adenocarcinoma cells. Irradiation of A549 cells remarkably increased the expression of YH206 antigen on the cell surface and the level of the antigen in the culture supernatant as well as in the cell lysate, whereas it significantly affected the expression of HLA (MHC-class I) antigen on the same cells. The expression of HLA antigen on the cell was also increased after treatment of the cells with interferon-γ. In an additional experiment, cells were stained simultaneously for surface antigens (fluorescein coupled antibodies) and for DNA content (propidium iodide), and then dual parameter measurements were performed by flow cytometry to analyse the relationship between antigen levels and the cell cycle. YH206 antigen and HLA antigen increased more in the S and G 2 /M phases of the cell cycle than in G 0 /G 1 . The expression of YH206 antigen was enhanced in the S and G 2 /M phases by irradiation, whereas the expression of HLA antigen was enhanced in each phase of the cell cycle with irradiation or IFN. These results suggest that irradiation plays a key role in the change of the expression of certain tumor-associated antigens. (author)

  16. Effects of surface friction and turbulent mixing on long-term changes in the near-surface wind speed over the Eastern China Plain from 1981 to 2010

    Science.gov (United States)

    Wu, Jian; Zha, Jinlin; Zhao, Deming; Yang, Qidong

    2017-11-01

    A significant slowdown in the near-surface wind speed (SWS) due to combined effects of the driving and drag forces of the atmosphere has been demonstrated in different regions in the globe. The drag force includes two sources: the friction force between the underlying surface and the bottom of the atmosphere, which is the external friction force (EFF), and the vertical exchange of the horizontal momentum induced by turbulent mixing, which is the turbulent friction force (TFF). In this paper, we propose a diagnostic method to separate the effects of the EFF and the TFF on long-term changes in the SWS over the Eastern China Plain (ECP) region from 1981 to 2010. The results show that the TFF could have caused an increase of 0.5 ± 0.2 m s- 1 in the SWS over the ECP region in the past 30 years and the TFF showed an increasing influence of 0.17 m s- 1 decade- 1. In contrast, the EFF distinctly decreased the SWS by an average of - 1.1 ± 0.4 m s- 1 and presented a significant decreasing trend of - 0.36 m s- 1 decade- 1. The effect of EFF is the main inducer of the observed regional long-term decrease of the SWS, which is in accordance with the distinct land use and cover change (LUCC) occurring in the ECP region in recent decades. Furthermore, the effects of the EFF and TFF on the changes in the SWS are more significant in large cities than those in small cities. The TFF effect can accelerate the SWS, with means of 0.5 ± 0.2 and 0.4 ± 0.2 m s- 1 in large and small cities, respectively. The EFF effect can decelerate the SWS, with means of - 1.2 ± 0.4 and - 0.7 ± 0.4 m s- 1 in large and small cities, respectively.

  17. An immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Science.gov (United States)

    Ichthyophthirius multifiliis (Ich) is a severe fish parasite that causes ‘white spot’ disease in many freshwater fish and leads to high mortality. The antigens on the parasite surface are involved in the antibody-mediated immobilization and hence designated as immobilization antigens (i-antigens). ...

  18. The COMET-L3 experiment on long-term melt. Concrete interaction and cooling by surface flooding

    International Nuclear Information System (INIS)

    Alsmeyer, H.; Cron, T.; Fluhrer, B.; Messemer, G.; Miassoedov, A.; Schmidt-Stiefel, S.; Wenz, T.

    2007-02-01

    The COMET-L3 experiment considers the long-term situation of corium/concrete interaction in an anticipated core melt accident of a light-water-reactor, after the metal melt is layered beneath the oxide melt. The experimental focus is on cavity formation in the basemat and the risk of long term basemat penetration. The experiment investigates the two-dimensional concrete erosion in a cylindrical crucible fabricated from siliceous concrete in the first phase of the test, and the influence of surface flooding in the second phase. Decay heating in the two-component metal and oxide melt is simulated by sustained induction heating of the metal phase that is overlaid by the oxide melt. The inner diameter of the concrete crucible was 60 cm, the initial mass of the melt was 425 kg steel and 211 kg oxide at 1665 C, resulting in a melt height of 450 mm. The net power to the metal melt was about 220 kW from 0 s to 1880 s, when the maximum erosion limit of the crucible was reached and heating was terminated. In the initial phase of the test (less than 100 s), the overheated, highly agitated metal melt causes intense interaction with the concrete, which leads to fast decrease of the initial melt overheat and reduction of the initially high concrete erosion rate. Thereafter, under quasistationary conditions until about 800 s, the erosion by the metal melt slows down to some 0.07 mm/s into the axial direction. Lateral erosion is a factor 3 smaller. Video observation of the melt surface shows an agitated melt with ongoing gas release from the decomposing concrete. Several periods of more intense gas release, gas driven splashing, and release of crusts from the concrete interface indicate the existence and iterative break-up of crusts that probably form at the steel/concrete interface. Surface flooding of the melt is initiated at 800 s by a shower from the crucible head with 0.375 litre water/s. Flooding does not lead to strong melt/water interactions, and no entrapment reactions or

  19. Molecular analysis of long-term biofilm formation on PVC and cast iron surfaces in drinking water distribution system.

    Science.gov (United States)

    Liu, Ruyin; Zhu, Junge; Yu, Zhisheng; Joshi, DevRaj; Zhang, Hongxun; Lin, Wenfang; Yang, Min

    2014-04-01

    To understand the impacts of different plumbing materials on long-term biofilm formation in water supply system, we analyzed microbial community compositions in the bulk water and biofilms on faucets with two different materials-polyvinyl chloride (PVC) and cast iron, which have been frequently used for more than10 years. Pyrosequencing was employed to describe both bacterial and eukaryotic microbial compositions. Bacterial communities in the bulk water and biofilm samples were significantly different from each other. Specific bacterial populations colonized on the surface of different materials. Hyphomicrobia and corrosion associated bacteria, such as Acidithiobacillus spp., Aquabacterium spp., Limnobacter thiooxidans, and Thiocapsa spp., were the most dominant bacteria identified in the PVC and cast iron biofilms, respectively, suggesting that bacterial colonization on the material surfaces was selective. Mycobacteria and Legionella spp. were common potential pathogenic bacteria occurred in the biofilm samples, but their abundance was different in the two biofilm bacterial communities. In contrast, the biofilm samples showed more similar eukaryotic communities than the bulk water. Notably, potential pathogenic fungi, i.e., Aspergillus spp. and Candida parapsilosis, occurred in similar abundance in both biofilms. These results indicated that microbial community, especially bacterial composition was remarkably affected by the different pipe materials (PVC and cast iron). Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  20. Long Term Validation of Land Surface Temperature Retrieved from MSG/SEVIRI with Continuous in-Situ Measurements in Africa

    Directory of Open Access Journals (Sweden)

    Frank-M. Göttsche

    2016-05-01

    Full Text Available Since 2005, the Land Surface Analysis Satellite Application Facility (LSA SAF operationally retrieves Land Surface Temperature (LST for the Spinning Enhanced Visible and Infrared Imager (SEVIRI on board Meteosat Second Generation (MSG. The high temporal resolution of the Meteosat satellites and their long term availability since 1977 make their data highly valuable for climate studies. In order to ensure that the LSA SAF LST product continuously meets its target accuracy of 2 °C, it is validated with in-situ measurements from four dedicated LST validation stations. Three stations are located in highly homogenous areas in Africa (semiarid bush, desert, and Kalahari semi-desert and typically provide thousands of monthly match-ups with LSA SAF LST, which are used to perform seasonally resolved validations. An uncertainty analysis performed for desert station Gobabeb yielded an estimate of total in-situ LST uncertainty of 0.8 ± 0.12 °C. Ignoring rainy seasons, the results for the period 2009–2014 show that LSA SAF LST consistently meets its target accuracy: the highest mean root-mean-square error (RMSE for LSA SAF LST over the African stations was 1.6 °C while mean absolute bias was 0.1 °C. Nighttime and daytime biases were up to 0.7 °C but had opposite signs: when evaluated together, these partially compensated each other.

  1. EVALUATION OF MACHINABILITY OF DUCTILE IRONS ALLOYED WITH Ni AND Cu IN TERMS OF CUTTING FORCES AND SURFACE QUALITY

    Directory of Open Access Journals (Sweden)

    Yücel AŞKUN

    2003-02-01

    Full Text Available Due to the enhanced strength, ductility and thoughness of Ductile Iron (DI when compared to the other types cast iron, its machinability is relatively poor. When a steel part is replaced with ductile iron, however, better machinability is considered to be the most important gain. This study presents the results of machining tests of ductile irons alloyed with Ni and Cu at various contents to determine the effect of their microstructure and mechanical properties on cutting forces and surface roughness. Six different specimen groups of ductile iron alloyed with various amounts of nickel and copper were subjected to machining tests and their machinabilities were investigated based on cutting forces and surface roughness criteria. The results were evaluated according to microstructure and mechanical properties of specimens determined before. In terms of both criterion, the best result obtained was specimen added 0.7 % Ni and 0.7 % Cu. When the specimens were evaluated according to their mechanical properties, the specimens alloyed 1 % Ni and 0.65 % Cu seemed promising.

  2. Ultrastructural features of supraspinal muscles in rabbits after long-term transcutaneous lateral electrical surface stimulation (LESS

    Directory of Open Access Journals (Sweden)

    Mariusz Majewski

    2005-12-01

    Full Text Available Lateral electrical surface stimulation is one of methods used in the therapy of the progressive form of idiopathic scoliosis (IS in children and youth. However, there are data suggesting that this method may lead to serious adverse side effects, when used for a too long period of time per day. To clarify this issue, the present study was aimed at disclosing possible changes in the ultrastructural appearance of rabbit supraspinal muscles undergoing long-term stimulation (9 h per day, 3 months, an animal model successfully used to mimic the situation in humans. In comparison to the control animals, muscles of "overstimulated" rabbits exhibited clear signs of microscopical lesions, including depletion and disintegration of myofilaments, proliferation, dilatation and, sometimes, swelling of sarcoplasmic reticulum and/or mitochondria, as well as signs of destruction of the Z line. The above-mentioned abnormalities, especially the signs of degenerative processes associated with the Z line and the observed microlesions strongly suggest that the failure of the long-term LESS therapy of the IS may be attributable to these ultrastructural lesions.

  3. A monkey antigen crossreacting with carcinoembryonic antigen, CEA.

    Science.gov (United States)

    Engvall, E.; Vuento, M.; Ruoslahti, E.

    1976-01-01

    Normal monkey tissues were found to contain an antigen which crossreacts immunologically with the carcinoembryonic antigen (CEA) of the human digestive tract. The monkey antigen reacted with complete or partial identity to the normal crossreacting antigen (NCA) in humans when tested in immunodiffusion against anti-CEA or anti-NCA. Extracts of monkey tissues inhibited in radioimmunoassays measuring human NCA. It is possible that monkey foetuses and colonic tumours contain CEA. Images Fig. 1 PMID:823952

  4. Long-Term Changes/Trends in Surface Temperature and Precipitation During the Satellite Era (1979-2012)

    Science.gov (United States)

    Gu, Guojun; Adler, Robert F.; Huffman, George J.

    2015-01-01

    During the post-1979 period in which the satellite-based precipitation measurements with global coverage are available, global mean surface temperature rapidly increased up to late 1990s, followed by a period of temperature hiatus after about 19981999. Comparing observed surface temperature trends against the simulated ones by the CMIP5 historical experiments especially in the zonal mean context suggests that although the anthropogenic greenhouse-gases (GHG) forcing has played a major role, in addition to the anthropogenic aerosols and various natural forcings, the effects from decadal-to-interdecadal scale internal modes specifically the Pacific Decadal Oscillation(PDO) are also very strong. Evident temperature changes associated with the PDOs phase shift are seen in the Pacific basin, with decadal-scale cooling in the tropical central-eastern Pacific and most of the east basin and concurrent warming in the subtropics of both hemispheres,even though the PDOs net effect on global mean temperature is relatively weak. The Atlantic Multidecadal Oscillation(AMO) also changed its phase in the mid-1990s, and hence its possible impact is estimated and assessed as well.However, comparisons with CMIP5 simulations suggest that the AMO may have not contributed as significantly as the PDO in terms of the changes trends in global surface temperature, even though the data analysis technique used here suggests otherwise. Long-term precipitation changes or trends during the post-1979 period are further shown to have been modulated by the two major factors:anthropogenic GHG and PDO, in addition to the relatively weak effects from aerosols and natural forcings. The spatial patterns of observed precipitation trends in the Pacific,including reductions in the tropical central-eastern Pacific and increases in the tropical western Pacific and along the South Pacific Convergence Zone, manifest the PDOs contributions.Removing the PDO effect from the total precipitation trends makes the

  5. Antigen smuggling in tuberculosis.

    Science.gov (United States)

    Hudrisier, Denis; Neyrolles, Olivier

    2014-06-11

    The importance of CD4 T lymphocytes in immunity to M. tuberculosis is well established; however, how dendritic cells activate T cells in vivo remains obscure. In this issue of Cell Host & Microbe, Srivastava and Ernst (2014) report a mechanism of antigen transfer for efficient activation of antimycobacterial T cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 58, č. 6 (2001), s. 425-430 ISSN 0001-2815. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 2.864, year: 2001

  7. CD antigens 2002

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 99, č. 10 (2002), s. 3877-3880 ISSN 0006-4971. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 9.631, year: 2002

  8. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 168, č. 5 (2002), s. 2083-2086 ISSN 0022-1767. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 7.014, year: 2002

  9. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 103, č. 4 (2001), s. 401-406 ISSN 0019-2805 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.656, year: 2001

  10. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 19, č. 6 (2001), s. 556-562 ISSN 1066-5099 R&D Projects: GA AV ČR IAA7052904 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.689, year: 2001

  11. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 31, č. 10 (2001), s. 2841-2847 ISSN 0014-2980 R&D Projects: GA AV ČR IAA7052904 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.990, year: 2001

  12. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 211, č. 2 (2001), s. 81-85 ISSN 0008-8749 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.604, year: 2001

  13. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 15, č. 1 (2002), s. 71-76 ISSN 0893-3952. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 3.821, year: 2002

  14. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 70, č. 5 (2001), s. 685-690 ISSN 0741-5400 R&D Projects: GA AV ČR IAA7052904 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.516, year: 2001

  15. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 13, č. 9 (2001), s. 1095-1098 ISSN 0953-8178 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.611, year: 2001

  16. β-endorphin antigen

    International Nuclear Information System (INIS)

    1981-01-01

    This invention relates to the production of antigens comprising β-endorphin, βsub(h)-endorphin, or βsub(c)-endorphin, in covalent conjugation with human gammaglobulin as immunogenic carrier material, and an antibody having the property of specifically binding β-endorphin or fragments thereof, containing the (6-15) residue sequence. (U.K.)

  17. Reduced prevalence of hepatitis B surface antigen positivity among pregnant women born after the national implementation of immunoprophylaxis for babies born to hepatitis B virus-carrier mothers in Japan.

    Science.gov (United States)

    Sugiyama, Aya; Ohisa, Masayuki; Nagashima, Shintaro; Yamamoto, Chikako; Chuon, Channarena; Fujii, Toshiko; Akita, Tomoyuki; Katayama, Keiko; Kudo, Yoshiki; Tanaka, Junko

    2017-11-01

    We aimed to estimate hepatitis B surface antigen (HBsAg) positivity among birth year-stratified pregnant women in Hiroshima, Japan, and compare prevalence rates between women born before and after implementation of a national immunoprophylactic vaccination program for babies born to hepatitis B virus (HBV) carrier mothers in Japan. Pregnant women who gave birth at all delivery hospitals/clinics in Hiroshima prefecture between 1 April 2010 and 31 March 2011 were eligible. Lists collected from each institution included survey items such as age (pregnant woman's birth year) and HBsAg and hepatitis C virus (HCV) antibody (anti-HCV) test results, which were posted anonymously and non-consolidated from medical records. We calculated the HBsAg and anti-HCV prevalence in our cohort according to the mothers' birth year. In 41 of 58 hospitals/clinics, 15 233 and 15 035 pregnant women underwent HBsAg and anti-HCV testing, corresponding to 59.6% and 58.9% of 25 546 births in the 2010 fiscal year, respectively. The overall HBsAg positive rate was 0.51% (95% confidence interval [CI], 0.40-0.63%), and an extremely low prevalence (0.10%; 95% CI, 0.00-0.25%) was observed among pregnant women born after 1986. However, the prevalence in this study was slightly higher than the nationwide value (0.31%) and the Chugoku region-specific value (0.46%) among first-time blood donors at Japanese Red Cross blood centers between 2001 and 2006. No significant difference in anti-HCV positivity was observed. Only two pregnant women born after the preventive program implementation were HBsAg-positive. Perinatal HBV transmission is estimated to be almost completely inhibited in the next generation. © 2017 The Authors. Hepatology Research published by John Wiley & Sons Australia, Ltd on behalf of Japan Society of Hepatology.

  18. Antigen Loss Variants: Catching Hold of Escaping Foes.

    Science.gov (United States)

    Vyas, Maulik; Müller, Rolf; Pogge von Strandmann, Elke

    2017-01-01

    Since mid-1990s, the field of cancer immunotherapy has seen steady growth and selected immunotherapies are now a routine and preferred therapeutic option of certain malignancies. Both active and passive cancer immunotherapies exploit the fact that tumor cells express specific antigens on the cell surface, thereby mounting an immune response specifically against malignant cells. It is well established that cancer cells typically lose surface antigens following natural or therapy-induced selective pressure and these antigen-loss variants are often the population that causes therapy-resistant relapse. CD19 and CD20 antigen loss in acute lymphocytic leukemia and chronic lymphocytic leukemia, respectively, and lineage switching in leukemia associated with mixed lineage leukemia (MLL) gene rearrangements are well-documented evidences in this regard. Although increasing number of novel immunotherapies are being developed, majority of these do not address the control of antigen loss variants. Here, we review the occurrence of antigen loss variants in leukemia and discuss the therapeutic strategies to tackle the same. We also present an approach of dual-targeting immunoligand effectively retargeting NK cells against antigen loss variants in MLL-associated leukemia. Novel immunotherapies simultaneously targeting more than one tumor antigen certainly hold promise to completely eradicate tumor and prevent therapy-resistant relapses.

  19. Cancer Patient T Cells Genetically Targeted to Prostate-Specific Membrane Antigen Specifically Lyse Prostate Cancer Cells and Release Cytokines in Response to Prostate-Specific Membrane Antigen

    Directory of Open Access Journals (Sweden)

    Michael C. Gong

    1999-06-01

    Full Text Available The expression of immunoglobulin-based artificial receptors in normal T lymphocytes provides a means to target lymphocytes to cell surface antigens independently of major histocompatibility complex restriction. Such artificial receptors have been previously shown to confer antigen-specific tumoricidal properties in murine T cells. We constructed a novel ζ chain fusion receptor specific for prostate-specific membrane antigen (PSMA termed Pz-1. PSMA is a cell-surface glycoprotein expressed on prostate cancer cells and the neovascular endothelium of multiple carcinomas. We show that primary T cells harvested from five of five patients with different stages of prostate cancer and transduced with the Pz-1 receptor readily lyse prostate cancer cells. Having established a culture system using fibroblasts that express PSMA, we next show that T cells expressing the Pz-1 receptor release cytokines in response to cell-bound PSMA. Furthermore, we show that the cytokine release is greatly augmented by B7.1-mediated costimulation. Thus, our findings support the feasibility of adoptive cell therapy by using genetically engineered T cells in prostate cancer patients and suggest that both CD4+ and CD8+ T lymphocyte functions can be synergistically targeted against tumor cells.