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Sample records for advia centaur hbsag

  1. The ADVIA Centaur infectious disease assays: a technical review.

    PubMed

    Dwyer, Robert

    2004-04-01

    Bayer Healthcare, Diagnostics Division, has developed several new several new assays for hepatitis B, hepatitis C and HIV 1/O/2 on the ADVIA Centaur Immunoassay system. The panel for detection of markers for hepatitis B infection includes assays for hepatitis B surface antigen (HBsAg) and HBsAg. Confirmatory, antibodies to hepatitis B surface antigen (anti-HBs), IgM and IgG antibodies to hepatitis B core antigen (anti-HBc Total) and IgM antibodies to hepatitis B core antigen (anti-HBc IgM). The hepatitis B panel is complemented by third generation assays for anti-HCV and anti-HIV that concomitantly detects HIV-1 (including group O) and HIV-2. The features of the ADVIA Centaur and the design of the assays combine to deliver state-of-the-art performance. Features, such as disposable sample pipette tips to prevent sample carryover, clot detection and management to verify sample addition, reagent integrity checks to assure accurate reagent addition, auto repeat capabilities and the capacity to maintain up to 30 assays onboard at 2-8 degrees C all contribute to the systems's utility for infectious disease testing. Furthermore, the flexibility of the ADVIA Centaur has allowed for selection of formats to provide optimal assay performance. The anti-HBs, anti-HBc Total and anti-HIV 1/O/2 assays are antigen-bridging assays. The anti-HBc IgM assay is a class-capture two step assay configured for detection of IgM anti-HBc antibodies during acute HBV infection. The anti-HCV assay is an indirect assay utilizing streptavidin-coated microparticles preformed with a combination of recombinant and synthetic peptide antigens from the NS2, NS4, NS5 and core regions of the HCV genome. The HBsAg assay is a sandwich assay with an incubation time of 28 minutes and the HBsAg Confirmatory assay is a fully automated neutralization assay. The availability of these assays on the ADVIA Centaur Immunoassay system enables laboratories to consolidate other immunoassays along with the infectious

  2. Performance Evaluation of Siemens ADVIA Centaur and Roche MODULAR Analytics E170 Total 25-OH Vitamin D Assays

    PubMed Central

    Chen, Yu; Kinney, Lois; Božović, Andrea; Smith, Hilary; Tarr, Heather; Diamandis, Eleftherios P.; LeBlanc, Adrien

    2014-01-01

    Objectives To evaluate the newly developed Roche MODULAR Analytics E170 Total Vitamin D and the Siemens ADVIA Centaur® Vitamin D Total assays. Materials and Methods Assays were evaluated using the Clinical and Laboratory Standards Institute protocols. Split patient samples were compared with LC-MS/MS and DiaSorin LIAISON assays (n=79 including 15 specimens with detectable endogenous 25-OH vitamin D2). Assay accuracy was also evaluated using the Vitamin D External Quality Assessment Scheme samples. Results The ADVIA Centaur and E170 assays demonstrated maximum total CVs of 14.1% and 5.9%, respectively. Both showed excellent linearity (R2 >0.99). The ADVIA Centaur assay demonstrated interference with bilirubin at 800 μmol/L, hemolysis at 1.25 g/L, and triglycerides at 2.8 mmol/L. Compared to LC-MS/MS, the ADVIA Centaur assay demonstrated a R2 value of 0.893, average bias of −8.8%; the E170 assay an R2 value of 0.872, average bias of 14.3% with underestimation of 25-OH vitamin D2. Compared to the LIAISON assay, the ADVIA Centaur assay demonstrated an R2 value of 0.781, average bias of −17.3%; the E170 assay an R2 value of 0.823, average bias of 11.4%. The ADVIA Centaur and E170 assays demonstrated a biases of <20% in 10/10 and 8/10 samples, respectively. Conclusions The ADVIA Centaur and E170 vitamin D assays demonstrated acceptable linearity, imprecision, and accuracy. The E170 assay demonstrated consistent underestimation of 25-OH vitamin D2 levels. Compared with LC-MS/MS, the ADVIA Centaur assay demonstrated a higher R2 value and a smaller average bias than the E170 assay. PMID:22705028

  3. An update on laboratory productivity with infectious disease assays on the Bayer ADVIA Centaur Immunoassay System.

    PubMed

    Dati, Francesco

    2004-01-01

    New biological materials and advances in robotic and computer technologies have enabled the development of automated systems designed for high-performance infectious disease immunoassays and nucleic acid amplification. The fully automated, random access Bayer ADVIA Centaur immunoassay system, offering testing for fertility, therapeutic drug monitoring, infectious disease, allergy, cardiovascular, anemia, oncology, TDMs and thyroid, has been specifically designed for use in large-volume laboratories. New immunoassay tests have been developed for the ADVIA Centaur for the hepatitis A virus, hepatitis B virus, hepatitis C virus and HIV. These assays have undergone extensive performance evaluation using samples designated in the CTS in support of obtaining the Communautés Européennes (CE) mark for European market distribution. The ADVIA Centaur Immunoassay System represents an optimal platform for infectious disease testing because of its flexibility in allowing many different assay formats and protocols with multiple incubation steps and washes coupled with its combination of magnetic particle separation and chemiluminescent detection. Additional quality features of the system design are the sample integrity verification/check, the use of disposable sample pipette tips, clot detection, the ability for sensing liquid levels, the reagent aspiration verification/check, the automatic cascade reflex testing, repeat testing, and automated reagent inventory. The ADVIA Centaur has a maximum test throughput of 240 tests per hour. Minimal hands-on time is required as a result of the large onboard capacity for reagents and supplies combined with automated maintenance and monitoring features, which streamline operations and result in a walk-away through-put of up to 840 tests.

  4. Comparison of ADVIA Centaur and Pharmacia UniCAP tests in the diagnosis of food allergy in children with atopic dermatitis.

    PubMed

    Contin-Bordes, Cécile; Petersen, Anita; Chahine, Isabelle; Boralevi, Franck; Chahine, Hikmat; Taïeb, Alain; Sarrat, Anne; Moreau, Jean-François; Taupin, Jean-Luc

    2007-11-01

    In a study comprising 63 children diagnosed with atopic dermatitis, the results of the ADVIA Centaur system was compared with the results obtained with the Pharmacia UniCAP100 system, which has been widely considered as a reference method for seric specific IgE (sIgE) measurements. The individual immunization against the most common food allergens [egg (f1), cow milk (f2), cod (f3), wheat (f4), peanut (f13) and soy bean (f14)] was determined by in vitro serum IgE testing and skin prick test (SPT). The comparison of the sIgE titers revealed a good concordance between the Centaur and the UniCAP tests for f1, f3, and f13 (94 %, 91 %, and 96 % respectively). However, the concordance was lower for f2, f4, and f14 (76 %, 77 %, and 77 % respectively) because of discrepancies between the two techniques. When compared with SPT and clinical diagnosis, on the 40 discordant cases found between the Centaur and the UniCAP, the Centaur showed concordance with the patients food reaction and SPT in 34/40 cases, and UniCAP in only 6/40 cases. Accordingly, the Centaur test displayed a statistically significantly better performance on specificity and concordance with SPT for f2, f4, and f14 (concordance/specificity = 70%/71%, 76%/75% and 90%/88% respectively), than the CAP test (49%/54%, 51%/52% and 67%/65% respectively).

  5. [Comparative study of parathormone and vitamin D measurements by three automats: ADVIA Centaur XP® (Siemens), ISYS® (IDS) and Liaison® (Diasorin)].

    PubMed

    Gardien, Pauline; Moineau, Marie-Pierre; Kerspern, Hélène; Bordron, Anne; Carre, Jean-Luc

    2014-01-01

    Vitamin D (Vit.D) and parathormone (PTH) measurements are usually prescribed for phosphocalcic metabolism assessment and, especially for Vit.D, more and more frequently for other pathologies. In order to step up to automated techniques for these analysis in our laboratory, we tested 3 devices: ADVIA Centaur XP(®) (Siemens), ISYS(®) (IDS) and Liaison(®) (Diasorin), which allow to simultaneously quantify Vit.D and PTH. The aim of this study was to evaluate the fidelity of these methods as well as study the correlation between them and the radioimmunological techniques previously used in our laboratory : « ELSA PTH » (Iba Cisbio International) and « 25-OH D » (IDS). The comparison of PTH analysis was performed on a population of chronic renal failure patients undergoing haemodialysis. According to our study, the 3 devices show acceptable analytical performances; anyway the measurements realized on the ISYS analyzer are the ones showing the best results in terms of fidelity, and the closest results to those obtained with the RIA reference techniques.

  6. [Comparative study of parathormone and vitamin D measurements by three automats: ADVIA Centaur XP® (Siemens), ISYS® (IDS) and Liaison® (Diasorin)].

    PubMed

    Gardien, Pauline; Moineau, Marie-Pierre; Kerspern, Hélène; Bordron, Anne; Carre, Jean-Luc

    2014-01-01

    Vitamin D (Vit.D) and parathormone (PTH) measurements are usually prescribed for phosphocalcic metabolism assessment and, especially for Vit.D, more and more frequently for other pathologies. In order to step up to automated techniques for these analysis in our laboratory, we tested 3 devices: ADVIA Centaur XP(®) (Siemens), ISYS(®) (IDS) and Liaison(®) (Diasorin), which allow to simultaneously quantify Vit.D and PTH. The aim of this study was to evaluate the fidelity of these methods as well as study the correlation between them and the radioimmunological techniques previously used in our laboratory : « ELSA PTH » (Iba Cisbio International) and « 25-OH D » (IDS). The comparison of PTH analysis was performed on a population of chronic renal failure patients undergoing haemodialysis. According to our study, the 3 devices show acceptable analytical performances; anyway the measurements realized on the ISYS analyzer are the ones showing the best results in terms of fidelity, and the closest results to those obtained with the RIA reference techniques. PMID:25119802

  7. Physical Properties of Centaur Objects

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Centaurs are objects in unstable orbits that cross the orbits of the giant planets. They are presumed to be recent additions to the planetary zone of the Solar System, having been dynamically perturbed from the Kulper Disk by the gravitational action of Neptune. Telescopic observations of Centaurs are important because they give us a view of the composition (and in some cases cometary activity) of large bodies that are normally to far from the Sun to be studied in detail. This paper reports on physical observations, primarily through spectroscopy, of the compositions of a small number of Centaurs that have been studied to date. In particular, the composition of 5145 Pholus is reviewed, following the published work of Crulkshank et al., in which compositional models that fit the spectrum well included H2O ice, the organic solid Titan tholin, a light hydrocarbon ice (e.g., CH3OH), the silicate mineral olivine, and amorphous carbon. The Centaur 1997 CU(26) shows evidence for H2O ice, but nothing else is yet identified.

  8. Centaur Propellant Thermal Conditioning Study

    NASA Technical Reports Server (NTRS)

    Blatt, M. H.; Pleasant, R. L.; Erickson, R. C.

    1976-01-01

    A wicking investigation revealed that passive thermal conditioning was feasible and provided considerable weight advantage over active systems using throttled vent fluid in a Centaur D-1s launch vehicle. Experimental wicking correlations were obtained using empirical revisions to the analytical flow model. Thermal subcoolers were evaluated parametrically as a function of tank pressure and NPSP. Results showed that the RL10 category I engine was the best candidate for boost pump replacement and the option showing the lowest weight penalty employed passively cooled acquisition devices, thermal subcoolers, dry ducts between burns and pumping of subcooler coolant back into the tank. A mixing correlation was identified for sizing the thermodynamic vent system mixer. Worst case mixing requirements were determined by surveying Centaur D-1T, D-1S, IUS, and space tug vehicles. Vent system sizing was based upon worst case requirements. Thermodynamic vent system/mixer weights were determined for each vehicle.

  9. Centaur propellant acquisition system study

    NASA Technical Reports Server (NTRS)

    Blatt, M. H.; Walter, M. D.

    1975-01-01

    A study was performed to determine the desirability of replacing the hydrogen peroxide settling system on the Centaur D-1S with a capillary acquisition system. A comprehensive screening was performed to select the most promising capillary device fluid acquisition, thermal conditioning, and fabrication techniques. Refillable start baskets and bypass feed start tanks were selected for detailed design. Critical analysis areas were settling and refilling, start sequence development with an initially dry boost pump, and cooling the fluid delivered to the boost pump in order to provide necessary net position suction head (NPSH). Design drawings were prepared for the start basket and start tank concepts for both LO2 and LH2 tanks. System comparisons indicated that the start baskets using wicking for thermal conditioning, and thermal subcooling for boost pump NPSH, are the most desirable systems for future development.

  10. Centaur operations at the space station

    NASA Technical Reports Server (NTRS)

    Porter, J.; Thompson, W.; Bennett, F.; Holdridge, J.

    1987-01-01

    A study was conducted on the feasibility of using a Centaur vehicle as a testbed to demonstrate critical OTV technologies at the Space Station. Two Technology Demonstration Missions (TDMs) were identified: (1) Accommodations, and (2) Operations. The Accommodations TDM contained: (1) berthing, (2) checkout, maintenance and safing, and (3) payload integration missions. The Operations TDM contained: (1) a cryogenic propellant resupply mission, and (2) Centaur deployment activities. A modified Space Station Co-Orbiting Platform (COP) was selected as the optimum refueling and launch node due to safety and operational considerations. After completion of the TDMs, the fueled Centaur would carry out a mission to actually test deployment and help offset TDM costs. From the Station, the Centaur could carry a single payload in excess of 20,000 pounds to geosynchronous orbit or multiple payloads.

  11. Centaur liquid oxygen boost pump vibration test

    NASA Technical Reports Server (NTRS)

    Tang, H. M.

    1975-01-01

    The Centaur LOX boost pump was subjected to both the simulated Titan Centaur proof flight and confidence demonstration vibration test levels. For each test level, both sinusoidal and random vibration tests were conducted along each of the three orthogonal axes of the pump and turbine assembly. In addition to these tests, low frequency longitudinal vibration tests for both levels were conducted. All tests were successfully completed without damage to the boost pump.

  12. New Limits to CO Outgassing in Centaurs

    NASA Astrophysics Data System (ADS)

    Drahus, Michał; Yang, Bin; Lis, Dariusz C.; Jewitt, David

    2016-09-01

    Centaurs are small solar system objects orbiting between Jupiter and Neptune. They are widely believed to be escapees from the trans-Neptunian region on their way to become Jupiter-family comets. Indeed, some Centaurs exhibit the characteristic cometary appearance. The sublimation of carbon monoxide has been proposed as a driver of activity in distant comets, but no strong detection of gaseous CO in a Centaur other than 29P/Schwassmann-Wachmann 1 has been reported to date. Here we report the results of a deep search for CO outgassing in three Centaurs: (315898), (342842), and (382004). Our survey was carried out using the Caltech Submillimeter Observatory on nine nights in late 2011. The targeted rotational line J(2-1) of CO is undetected in all three objects in spite of high instrumental sensitivity. We find the model-dependent three-sigma upper limits to the CO production rate of 2.13 × 1027 molecules s-1 for (315898), 1.32 × 1027 molecules s-1 for (342842), and 1.17 × 1027 molecules s-1 for (382004), which are among the most sensitive obtained to date. These upper limits are consistently analyzed in the context of published CO data of fourteen Centaurs and one well-observed comet, C/1995 O1 (Hale-Bopp), and support an earlier suggestion that the surfaces of most Centaurs are not dominated by exposed CO ice.

  13. SURVIVAL OF AMORPHOUS WATER ICE ON CENTAURS

    SciTech Connect

    Guilbert-Lepoutre, Aurelie

    2012-10-01

    Centaurs are believed to be Kuiper Belt objects in transition between Jupiter and Neptune before possibly becoming Jupiter family comets. Some indirect observational evidence is consistent with the presence of amorphous water ice in Centaurs. Some of them also display a cometary activity, probably triggered by the crystallization of the amorphous water ice, as suggested by Jewitt and this work. Indeed, we investigate the survival of amorphous water ice against crystallization, using a fully three-dimensional thermal evolution model. Simulations are performed for varying heliocentric distances and obliquities. They suggest that crystallization can be triggered as far as 16 AU, though amorphous ice can survive beyond 10 AU. The phase transition is an efficient source of outgassing up to 10-12 AU, which is broadly consistent with the observations of the active Centaurs. The most extreme case is 167P/CINEOS, which barely crystallizes in our simulations. However, amorphous ice can be preserved inside Centaurs in many heliocentric distance-obliquity combinations, below a {approx}5-10 m crystallized crust. We also find that outgassing due to crystallization cannot be sustained for a time longer than 10{sup 4}-10{sup 4} years, leading to the hypothesis that active Centaurs might have recently suffered from orbital changes. This could be supported by both observations (although limited) and dynamical studies.

  14. First Titan-Centaur Launch Test

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The first Titan/Centaur lifted off from Complex 41 at Cape Kennedy Air Force Station at 9:48 AM EDT. The Titan stages burned as programmed, but when the Centaur stage failed to ignite, the Range Safety Officer destroyed it. The new NASA rocket was launched on a proof of concept flight designed to prepare it for twin Viking launches to Mars in 1975 and other missions involving heavy payloads. The 160-foot-tall rocket combines the Air Force Titan III with the NASA high-energy Centaur final stage. The twin solid rocket boosters have a combined liftoff thrust of 2.4 million pounds. Aboard Titan/ Centaur on its proof of concept flight were a dynamic simulator of the Viking spacecraft and a small scientific satellite (SPHINX) designed to determine how high voltage solar cells, insulators, and conductors are affected by the charges particles in space. KSC's Unmanned Launch Operations Directorate conducted the launch. For more information about Titan and Centaur, please see Chapters 4 and 8, respectively, in Roger Launius and Dennis Jenkins' book To Reach the High Frontier published by The University Press of Kentucky in 2002.

  15. New Scattered Disk Object and Centaur Colors

    NASA Astrophysics Data System (ADS)

    Brucker, Melissa; Wilcox, P.; Stansberry, J.

    2013-10-01

    We report B, V, and R magnitudes for scattered disk objects and centaurs from observations taken in December 2011 and August 2013 using the Lowell Observatory Perkins Telescope with PRISM and observations taken in March 2012 at the Vatican Advanced Technology Telescope (VATT) on Mt. Graham, Arizona. Targeted scattered disk objects include 2002 CY224, 2003 UY117, 2006 QJ181, 2008 CT190, 2009 YG19, 2010 FD49, 2010 VZ98. Targeted centaurs include 2002 QX47, 2005 UJ438, 2006 UX184, and 2007 RH283. We will determine if the resultant centaur colors follow the bimodal distribution (B-R either red or gray) previously detected. We will also compare the resultant scattered disk object colors to those published for other scattered disk objects. This work is based on observations with the Perkins Telescope at Lowell Observatory, and with the VATT: The Alice P. Lennon Telescope and the Thomas J. Bannan Astrophysics Facility.

  16. Centaurs as a hazard to civilization

    NASA Astrophysics Data System (ADS)

    Napier, Bill; Asher, David; Bailey, Mark; Steel, Duncan

    2015-12-01

    Assessments of the risk posed by near-Earth objects ignore the possibility of a giant comet entering the inner solar system. Bill Napier, David Asher, Mark Bailey and Duncan Steel examine the likelihood and potential consequences of the appearance of such a centaur.

  17. Shuttle/Centaur Upper Stage Capability

    NASA Technical Reports Server (NTRS)

    Clark, H. J.

    1984-01-01

    A joint project to design, develop, procure, and produce Centaur upper stages for use with the Space Shuttle is discussed. A common Centaur G stage 6 meters (19.5 feet) in length is being jointly developed. A longer version designated Centaur G Prime is being developed by NASA to accomplish the Galileo and International Solar-Polar Mission flights in 1986. The Centaur G and G Prime will have the capability to place, respectively, approximately 4540 kilograms (10,000 pounds) and 5910 kilograms (13,000 pounds) into geosynchronous orbit from a standard Shuttle parking orbit of 278 kilometers (150 nautical miles) and Shuttle performance (lift) capability 29,500 kilograms (65,000 pounds). The advent of high energy upper stage capability in 1986 will permit space users and spacecraft developers to utilize spacecraft growth, stage combination concepts with storage modules, teleoperator systems, and other mission peculiar devices to satisfy complex mission demands. These capabilities should greatly enhance the usefulness of the space environment and stimulate mission planners toward conception of innovative means to meet ever increasing mission requirements.

  18. WISE Views of Centaurs & Scattered Disk Objects

    NASA Technical Reports Server (NTRS)

    Bauer, J. M.; Walker, R.; Mainzer, A.; Blauvelt, E.; Masiero, J.; Grav, T.; Cutri, R.; Dailey, J.; Lisse, C. M.; Fernandez, Y. R.; Meech, K. J.; McMillan, R.; Tholen, D.; Wright, E. L.

    2011-01-01

    The Wide Field Infrared Survey Explorer surveyed most of the sky in the Mid-Infrared From January through September of 2010. In addition to 120 comets, more than 30 Centaurs and Scattered Disc Objects (SDOs) were observed and discovered. We will present preliminary results from the analysis ofthese outer solar system bodies.

  19. Role of simulation and emulation in the development of Shuttle-Centaur (STS-Centaur)

    NASA Technical Reports Server (NTRS)

    Gordan, A. L.

    1983-01-01

    To support the task of integrating the Centaur liquid-fueled upper-stage space vehicle into the space shuttle program. A system to simulate and emulate the STS-Centaur avionic flight system and its supporting ground control and checkout equipment was selected and designated the systems integration facility (SIF). Located in San Diego, California, the SIF is composed of integrated simulators that form a composite control system complement to the STS-Centaur airborne and avionic support equipment. An off-line capability to verify the system design of the Centaur airborne support equipment (CASE) and the Centaur avionic flight system is provided as well as a realistic medium for the development and integration of ground checkout and airborne control software programs. Each simulator is composed of prototype hardware, where feasible, to maximize configuration likeness. Where emulated flight or ground hardware is used, it provides physical characteristics (loads, signals, etc.) equivalent to those of the flight hardware. The hardware and software implementation of the SIF are described.

  20. Evaluation of two new automated assays for hepatitis B virus surface antigen (HBsAg) detection: IMMULITE HBsAg and IMMULITE 2000 HBsAg.

    PubMed

    Weber, Bernard; Dengler, Thomas; Berger, Annemarie; Doerr, Hans Wilhelm; Rabenau, Holger

    2003-01-01

    In recent years the diagnostic industry has developed new automated immunoassays for the qualitative detection of hepatitis B virus (HBV) surface antigen (HBsAg) in serum and plasma samples that are performed on analyzers that permit a high-speed throughput, random access, and primary tube sampling. The aim of the present study was the evaluation of two new automated HBsAg screening assays, IMMULITE HBsAg and IMMULITE 2000 HBsAg, from Diagnostic Products Corporation. The new HBsAg assays were compared to well-established tests (Auszyme Monoclonal [overnight incubation, version B], IMx HBsAg, AxSYM HBsAg, and Prism HBsAg [all from Abbott] and Elecsys HBsAg [Roche Diagnostics]). In the evaluation were included seroconversion panels, sera from the acute and chronic phases of infection, dilution series of various HBsAg standards, HBV subtypes and S gene mutants. To challenge the specificity of the new assays, sera from HBsAg-negative blood donors, pregnant women, and dialysis and hospitalized patients and potentially cross-reactive samples were investigated. IMMULITE HBsAg and IMMULITE 2000 HBsAg, although not as sensitive as the Elecsys HBsAg assay, were equivalent to the AxSYM HBsAg assay and showed a higher sensitivity than the Auszyme Monoclonal B and IMx HBsAg systems for detection of acute infection in seroconversion panels. The specificities (100%) of both IMMULITE assays on unselected blood donors and potentially interfering samples were comparable to those of the alternative assays after repeated testing. In conclusion, the new IMMULITE HBsAg and IMMULITE 2000 HBsAg assays show a good sensitivity for HBsAg detection compared to other well-established tests. The specificity on repeatedly tested samples was equivalent to that of the alternative assays. The rapid turnaround time, primary tube sampling, and on-board dilution make it an interesting assay system for clinical laboratory diagnosis.

  1. Taming Liquid Hydrogen: The Centaur Upper Stage Rocket

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The Centaur is one of the most powerful rockets in the world. As an upper-stage rocket for the Atlas and Titan boosters it has been a reliable workhorse for NASA for over forty years and has played an essential role in many of NASA's adventures into space. In this CD-ROM you will be able to explore the Centaur's history in various rooms to this virtual museum. Visit the "Movie Theater" to enjoy several video documentaries on the Centaur. Enter the "Interview Booth" to hear and read interviews with scientists and engineers closely responsible for building and operating the rocket. Go to the "Photo Gallery" to look at numerous photos of the rocket throughout its history. Wander into the "Centaur Library" to read various primary documents of the Centaur program. Finally, stop by the "Observation Deck" to watch a virtual Centaur in flight.

  2. Centaur Standard Shroud (CSS) static ultimate load structural tests

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A series of tests were conducted on the jettisonable metallic shroud used on the Titan/Centaur launch vehicle to verify its structural capabilities and to evaluate its structural interaction with the Centaur stage. A flight configured shroud and the interfacing Titan/Centaur structural assemblies were subjected to tests consisting of combinations of applied axial and shear loads to design ultimate values, including a set of tests on thermal conditions and two dynamic response tests to verify the analytical stiffness model. The strength capabilities were demonstrated at ultimate (125 percent of design limit) loads. It was also verified that the spring rate of the flight configured shroud-to-Centaur forward structural deflections of the specimen became nonlinear, as expected, above limit load values. This test series qualification program verified that the Titan/Centaur shroud and the Centaur and Titan interface components are qualified structurally at design ultimate loads.

  3. Centaur's ring system formation by close encounters

    NASA Astrophysics Data System (ADS)

    De Santana, Thamiris; Winter, Othon

    2016-10-01

    Rupture of small bodies due to close approach to a massive body is a frequent event in the Solar System. Some of these small bodies can just disintegrate completely or suffer a material loss.In this work we study the gravitational interaction between a giant planet and a small body in close encounters in order to simulate the formation of a planetary ring system around a centaur by the partial rupture of the small body.Considering the current Chariklo's body and a disk of particles around it, we simulated the system under close encounters with one of giant planets.Another motivation for the study is also the centaur Chiron, that is a candidate to have a ring system like Chariklo. The characteristics of the encounters are defined by the impact parameter and the velocity at infinity.The results are presented in terms of conditions that could lead to a rupture that could generate a ring like system.

  4. Centaur upper-stage rocket for shuttle

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A popular topic for discussion among those still hoping that the National Aeronautics and Space Administration's (NASA) space shuttle will be able to launch large scientific space probes from earth orbit is the matter of the so-called US, or upper-stage, rocket vehicle. Programs slated for the middle of the decade that include sending probes deep into space will not be possible without a very powerful upper-stage rocket, and thus there was a surge of optimism among space scientists and NASA officials this past September when Congress voted not to eliminate the big Centaur rocket from space shuttle's portion of the NASA 1983 fiscal year budget.Support for construction of the Centaur followed the Air Force's requirement for greater lifting power because of the shielding required to prevent contamination of certain classified payloads (Science, 1 October 1982). The large rocket will also be needed to place massive communications satellites into geosynchronous earth orbit.

  5. The Ices on Transneptunian Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    de Bergh, C.; Schaller, E. L.; Brown, M. E.; Brunetto, R.; Cruikshank, D. P.; Schmitt, B.

    Transneptunian objects (TNOs) and Centaurs are small bodies orbiting the Sun in the cold outer regions of the Solar System. TNOs include Pluto and its satellite Charon, and Neptune's large satellite Triton is thought to have been captured from the TNO population. Visible and near-infrared spectroscopy of a number of the brightest of these bodies shows surface ices of H2O, CH4, N2, CH3OH, C2H6, CO, CO2, NH3•nH2O, and possibly HCN, in various combinations; water ice is by far the most common. Silicate minerals and solid complex carbonaceous materials are thought to occur on these bodies, but their spectral signatures have not yet been positively identified. The pronounced red color of several TNOs and Centaurs is presumed to result from the presence of carbonaceous materials. In all, the TNOs and Centaurs are thought to be primitive bodies in the sense that they have undergone relatively little modification by heating and by the space environment since their condensation in the volatile-rich outer regions of the solar nebula. As such, they hold the potential to yield important information on the chemical and physical conditions of the solar nebula. Continued and expanded studies of TNOs and Centaurs require additional basic laboratory data on the physical and the optical properties of the ices already identified and those candidate materials that have not yet been confirmed. New sky surveys and large telescopes projected for operation in the near future will reveal many more objects in the outer Solar System for detailed study.

  6. The Dynamical Classification of Centaurs which Evolve into Comets

    NASA Astrophysics Data System (ADS)

    Wood, Jeremy R.; Horner, Jonathan; Hinse, Tobias; Marsden, Stephen; Swinburne University of Technology

    2016-10-01

    Centaurs are small Solar system bodies with semi-major axes between Jupiter and Neptune and perihelia beyond Jupiter. Centaurs can be further subclassified into two dynamical categories – random walk and resonance hopping. Random walk Centaurs have mean square semi-major axes (< a2 >) which vary in time according to a generalized diffusion equation where < a2 > ~t2H. H is the Hurst exponent with 0 < H < 1, and t is time. The behavior of < a2 > for resonance hopping Centaurs is not well described by generalized diffusion.The aim of this study is to determine which dynamical type of Centaur is most likely to evolve into each class of comet. 31,722 fictional massless test particles were integrated for 3 Myr in the 6-body problem (Sun, Jovian planets, test particle). Initially each test particle was a member of one of four groups. The semi-major axes of all test particles in a group were clustered within 0.27 au from a first order, interior Mean Motion resonance of Neptune. The resonances were centered at 18.94 au, 22.95 au, 24.82 au and 28.37 au.If the perihelion of a test particle reached < 4 au then the test particle was considered to be a comet and classified as either a random walk or resonance hopping Centaur. The results showed that over 4,000 test particles evolved into comets within 3 Myr. 59% of these test particles were random walk and 41% were resonance hopping. The behavior of the semi-major axis in time was usually well described by generalized diffusion for random walk Centaurs (ravg = 0.98) and poorly described for resonance hopping Centaurs (ravg = 0.52). The average Hurst exponent was 0.48 for random walk Centaurs and 0.20 for resonance hopping Centaurs. Random walk Centaurs were more likely to evolve into short period comets while resonance hopping Centaurs were more likely to evolve into long period comets. For each initial cluster, resonance hopping Centaurs took longer to evolve into comets than random walk Centaurs. Overall the population of

  7. Centaur Application to Robotic and Crewed Lunar Lander Evolution

    NASA Astrophysics Data System (ADS)

    Birckenstaedt, Bonnie; Kutter, Bernard F.; Zegler, Frank

    2007-01-01

    Human space exploration, while a clear imperative for the progression of human civilization, can be severely impeded by excessively high operational costs and perceived high risk. A cost effective method of accomplishing every phase of exploration transport is mandatory to avoid this trap. Centaur, the upper stage on the current Lockheed Martin Atlas V rocket, is an excellent candidate for modification as a robotic and possible human transport vehicle to our nearest neighbor. The Centaur is produced in Denver, Colorado. Centaur has proven to be extremely robust and reliable, with 77 consecutive successful flights. Modifications to the current design would allow the Centaur to function as an in-space propulsion system. With its present capability Centaur can directly support robotic probe landings on the moon and is directly extensible to larger landing tasks including high-mass crewed missions. Lunar descent would be accomplished in two phases: primary descent using the RL10 engine and a final horizontal terminal phase powered by pressure fed thrusters mounted along the Centaur tank. Utilizing the Centaur for human exploration would greatly reduce cost by leveraging an already designed and manufactured stage. It would increase safety by its robustness and redundancy that the Centaur has proven in many successful launches. With the Centaur concept for human exploration, NASA can have the safety and cost effectiveness needed to explore the Moon, Mars, and beyond.

  8. Reusable Centaur study. Volume 1: Executive summary. [development costs of Centaur launch vehicle as upper stage for space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Heald, D. A.

    1974-01-01

    A study of the Reusable Centaur for use as an initial upper stage with the space shuttle was conducted. The currently operative Centaur stage, with modifications for space shuttle orbiter compatibility and for improved performance, represents a cost effective development solution. The performance needs and available development funds are discussed. The main features of three Reusable Centaur configurations with increasing capability at increasing development costs are summarized.

  9. Centaur Chiron's Calendar in our era

    NASA Astrophysics Data System (ADS)

    Spanos, S.

    2012-01-01

    Centaur Chiron's Calendar is an educational activity incorporated in environmental education which combines the principles of inter-scientific approach with fundamental astronomy conception. It is performed in school as a yearly environmental project. The famous centaur was teaching the hero Jason (and others) navigation based on stellar observation and medicine based on Pelion herbs collected at the right time of the year. Students are guided to discover his method of determination of the right time. The project evolves the creation of a photographic calendar based on collected pictures from the sunset during the various seasons of the year. It is developed in the same region that Chiron lived (Mount Pelion) according to mythology but it can be modified for use in other regions. Sunset positions are recorded daily or weekly and plotted on a wide-angle picture of the western hill crest. Students are then called to predict the date of a given sunset position. Students also record sunset time and duration of the day in order to relate it with the photographic calendar. The activity combines knowledge from various scientific fields such as history, geography and astronomy. Development of practical skills such as accurate observation, photography techniques and digital image processing is a welcomed side effect of this educational activity.

  10. Two Color Populations of Kuiper Belt and Centaur Objects

    NASA Astrophysics Data System (ADS)

    Tegler, Stephen C.; Romanishin, William; Consolmagno, Guy

    2016-10-01

    We present new optical colors for 64 Kuiper belt objects (KBOs) and Centaur objects measured with the 1.8-meter Vatican Advanced Technology Telescope (VATT) and the 4.3-meter Discovery Channel Telescope (DCT). By combining these new colors with our previously published colors, we increase the sample size of our survey to 154 objects. Our survey is unique in that the uncertainties in our color measurements are less than half the uncertainties in the color measurements reported by other researchers in the literature. Small uncertainties are essential for discerning between a unimodal and a bimodal distribution of colors for these objects as well as detecting correlations between colors and orbital elements. From our survey, it appears red Centaurs have a broader color distribution than grey Centaurs. We find red Centaurs have a smaller orbital inclination angle distribution than grey Centaurs at the 99.3% confidence level. Furthermore, we find that our entire sample of KBOs and Centaurs exhibits bimodal colors at the 99.4% confidence level. KBOs and Centaurs with HV > 7.0 have bimodal colors at the 99.96% confidence level and KBOs with HV < 6.0 have bimodal colors at the 96.3% confidence level.We are grateful to the NASA Solar System Observations Program for support, NAU for joining the Discovery Channel Telescope Partnership, and the Vatican Observatory for the consistent allocation of telescope time over the last 12 years of this project.

  11. Centaur operations at the space station: Cost and transportation analysis

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A study was conducted to expand on the results of an initial study entitled Centaur Operations at the Space Station. The previous study developed technology demonstration missions (TDMs) that utilized the Centaur G-prime upper stage to advance OTV technologies required for accomodations and operations at the Space Station. An initial evaluation was performed of the cost to NASA for TDM implementation. Due to the potential for commercial communication satellite operation utilizing the TDM hardware, an evaluation of the Centaur's transportation potential was also performed.

  12. Centaur space vehicle pressurized propellant feed system tests

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Engine firing tests, using a full-scale flight-weight vehicle, were performed to evaluate a pressurized propellant feed system for the Centaur. The pressurant gases used were helium and hydrogen. The system was designed to replace the boost pumps currently used on Centaur. Two liquid oxygen tank pressurization modes were studied: (1) directly into the ullage and (2) below the propellant surface. Test results showed the two Centaur RL10 engines could be started and run over the range of expected flight variables. No system instabilities were encountered. Measured pressurization gas quantities agreed well with analytically predicted values.

  13. Atlas IIA/Centaur rocket arrives at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    At Cape Canaveral Air Force skid strip, the Centaur upper stage is placed aboard a transporter after arriving aboard a Russian cargo plane, the Antenov 124. The Centaur will be coupled with an Atlas IIA to launch the latest Tracking and Data Relay Satellite (TDRS) June 29 from Cape Canaveral Air Force Station. The Centaur, manufactured and operated by Lockheed Martin, is 3.05 m (10 ft) in diameter and 10.0 m (33-ft) long. It uses liquid hydrogen (LH2) and liquid oxygen (LO2) propellants.

  14. Atlas IIA/Centaur rocket arrives at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers at Cape Canaveral Air Force skid strip oversee the offloading of the Centaur upper stage from a Russian cargo plane, the Antenov 124. The Centaur will be coupled with an Atlas IIA to launch the latest Tracking and Data Relay Satellite (TDRS) June 29 from Cape Canaveral Air Force Station. The Centaur, manufactured and operated by Lockheed Martin, is 3.05 m (10 ft) in diameter and 10.0 m (33-ft) long. It uses liquid hydrogen (LH2) and liquid oxygen (LO2) propellants.

  15. Atlas IIA/Centaur rocket arrives at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    - A Russian cargo plane, the Antenov 124, arrives at Cape Canaveral Air Force skid strip to deliver the Atlas IIA/Centaur rocket scheduled to launch the latest Tracking and Data Relay Satellite (TDRS) June 29 from Cape Canaveral Air Force Station. Visible is the Centaur upper stage, manufactured and operated by Lockheed Martin. The Centaur vehicle is 3.05 m (10 ft) in diameter and 10.0 m (33-ft) long. It uses liquid hydrogen (LH2) and liquid oxygen (LO2) propellants.

  16. The Launch of an Atlas/Centaur Launch Vehicle

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The launch of an Atlas/Centaur launch vehicle is shown in this photograph. The Atlas/Centaur, launched on November 13, 1978, carried the High Energy Astronomy Observatory (HEAO)-2 into the required orbit. The second observatory, the HEAO-2 (nicknamed the Einstein Observatory in honor of the centernial of the birth of Albert Einstein) carried the first telescope capable of producing actual photographs of x-ray objects.

  17. RL10 ignition limits test for Shuttle Centaur

    NASA Technical Reports Server (NTRS)

    1987-01-01

    During routine development testing of the RL10A-3-3B engine a potential no-ignition condition was encountered when operating at certain propellant inlet conditions within the Shuttle Centaur G operating region. The conditions, the resulting investigative program, and methods to correct the potential problem are discussed. The Shuttle Centaur program was cancelled prior to completion of this effort. Although the RL10 engine in the Atlas Centaur vehicle is required by specification to operate over a wide range of propellant inlet conditions. The vehicle actually operates over a narrow range of conditions. This factor, combined with configuration differences between Atlas Centaur (or Titan Centaur) and the Shuttle Centaur RL10 engines, indicates the ignition problem does not exist for these vehicles. As a precautionary measure the vehicle manufacturer was requested to coordinate with Pratt and Whitney any anticipated changes in propellant inlet conditions from the current narrow range. An engineering change will be proposed for future RL10 deliveries to provide more consistent propellant flow to the igniter. This will permit operation of the engine throughout the wide range specification inlet conditions if desired.

  18. Optical alignment of Centaur's inertial guidance system

    NASA Technical Reports Server (NTRS)

    Gordan, Andrew L.

    1987-01-01

    During Centaur launch operations the launch azimuth of the inertial platform's U-accelerometer input axis must be accurately established and maintained. This is accomplished by using an optically closed loop system with a long-range autotheodolite whose line of sight was established by a first-order survey. A collimated light beam from the autotheodolite intercepts a reflecting Porro prism mounted on the platform azimuth gimbal. Thus, any deviation of the Porro prism from its predetermined heading is optically detected by the autotheodolite. The error signal produced is used to torque the azimuth gimbal back to its required launch azimuth. The heading of the U-accelerometer input axis is therefore maintained automatically. Previously, the autotheodolite system could not distinguish between vehicle sway and rotational motion of the inertial platform unless at least three prisms were used. One prism was mounted on the inertial platform to maintain azimuth alignment, and two prisms were mounted externally on the vehicle to track sway. For example, the automatic azimuth-laying theodolite (AALT-SV-M2) on the Saturn vehilce used three prisms. The results of testing and modifying the AALT-SV-M2 autotheodolite to simultaneously monitor and maintain alignment of the inertial platform and track the sway of the vehicle from a single Porro prism.

  19. Centaur Standard Shroud (CSS) static limit load structural tests

    NASA Technical Reports Server (NTRS)

    Eastwood, C.

    1975-01-01

    The structural capabilities of the jettisonable metal shroud were tested and the interaction of the shroud with the Centaur stage was evaluated. A flight-configured shroud and the assemblies of the associated Centaur stage were tested for applied axial and shear loads to flight limit values. The tests included various thermal, pressure, and load conditions to verify localized strength capabilities, to evaluate subsystem performance, and to determine the aging effect on insulation system properties. The tests series verified the strength capabilities of the shroud and of all associated flight assembles. Shroud deflections were shown to remain within allowable limits so long as load sharing members were connected between the shroud and the Centaur stage.

  20. The extreme Centaur 2013 AZ_{60}

    NASA Astrophysics Data System (ADS)

    Kiss, C.; Horner, J.; Pal, A.; Szakats, R.; Vilenius, E.; Acosta-Pulido, J.; Sarneczky, K.; Szabo, G.; Duffard, R.

    2014-07-01

    2013 AZ_{60} is an extreme Centaur moving on a highly eccentric orbit of e = 0.9922, with a semimajor axis of 1021.09 au, and a perihelion distance of 7.91 au. 2013 AZ_{60} was observed with the PACS camera of the Herschel Space Observatory, and, using these thermal emission measurements, we were able to derive an effective size of 66.5±3.7 km in diameter, and a geometric albedo of p_V=0.026±0.003. Photometric measurements revealed a low-amplitude lightcurve (0.045±0.007mag in the r' band) with a likely full period of P=9.39 h. The dynamical analysis shows that the orbit of 2013 AZ_{60} is highly unstable, with a ˜50 per cent probability that the target is ejected from the Solar System after about 700 kyr. This high level of instability indicates that 2013 AZ_{60} may just have recently been captured to its current orbit. Investigating the total time the target could have spent at small heliocentric distances (< 100 au), it seems to be likely that this has only been at most 100 to 1000 years and it has a low probability that the target could reach Earth-crossing orbits (i.e., < 1 au). As the likely origin of this target is the Oort Cloud, these together suggests a relatively unaltered, pristine surface, in contradiction with the very low albedo (˜2.6 per cent) derived from the thermal infrared measurements which rather indicates an ''extinct cometary'' surface, also in agreement with the photometric colors.

  1. Quantification of HBsAg: basic virology for clinical practice.

    PubMed

    Lee, Jung Min; Ahn, Sang Hoon

    2011-01-21

    Hepatitis B surface antigen (HBsAg) is produced and secreted through a complex mechanism that is still not fully understood. In clinical fields, HBsAg has long served as a qualitative diagnostic marker for hepatitis B virus infection. Notably, advances have been made in the development of quantitative HBsAg assays, which have allowed viral replication monitoring, and there is an opportunity to make maximal use of quantitative HBsAg to elucidate its role in clinical fields. Yet, it needs to be underscored that a further understanding of HBsAg, not only from clinical point of view but also from a virologic point of view, would enable us to deepen our insights, so that we could more widely expand and apply its utility. It is also important to be familiar with HBsAg variants and their clinical consequences in terms of immune escape mutants, issues resulting from overlap with corresponding mutation in the P gene, and detection problems for the HBsAg variants. In this article, we review current concepts and issues on the quantification of HBsAg titers with respect to their biologic nature, method principles, and clinically relevant topics.

  2. A Chemical and Dynamical Link Between Red Centaur Objects and the Cold Classical Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Tegler, Stephen C.; Romanishin, William; Consolmagno, Guy

    2015-11-01

    We present new B-V, V-R, and B-R colors for 32 Centaurs objects using the 4.3-meter Discovery Channel Telescope (DCT) near Happy Jack, AZ and the 1.8-meter Vatican Advanced Technology Telescope on Mt. Graham, AZ. Combining these new colors with our previously reported colors, we now have optical broad-band colors for 58 Centaur objects.Application of the non-parametric Dip Test to our previous sample of only 26 objects showed Centaurs split into gray and red groups at the 99.5% confidence level, and application of the Wilcoxon Rank Sum Test to the same sample showed that red Centaurs have a higher median albedo than gray Centaurs at the 99% confidence level (Tegler et al., 2008, Solar System Beyond Neptune, U Arizona Press, pp. 105-114).Here we report application of the Wilcoxon Rank Sum Test to our sample of 58 Centaurs. We confirm red Centaurs have a higher median albedo than gray Centaurs at the 99.7% level. In addition, we find that red Centaurs have a lower median inclination angle than gray Centaurs at the 99.5% confidence level. Because of their red colors and lower inclination angles, we suggest red Centaurs originate in the cold classical Kuiper belt. We thank the NASA Solar System Observations Program for its support.

  3. Shuttle Centaur engine cooldown evaluation and effects of expanded inlets on start transient

    NASA Technical Reports Server (NTRS)

    1987-01-01

    As part of the integration of the RL10 engine into the Shuttle Centaur vehicle, a satisfactory method of conditioning the engine to operating temperatures had to be established. This procedure, known as cooldown, is different from the existing Atlas Centaur due to vehicle configuration and mission profile differenced. The program is described, and the results of a Shuttle Centaur cooldown program are reported. Mission peculiarities cause substantial variation in propellant inlet conditions between the substantiated Atlas Centaur and Shuttle Centaur with the Shuttle Centaur having much larger variation in conditions. A test program was conducted to demonstrate operation of the RL10 engine over the expanded inlet conditions. As a result of this program, the Shuttle Centaur requirements were proven satisfactory. Minor configuration changes incorporated as a result of this program provide substantial reduction in cooldown propellant consumption.

  4. Centaur engine gimbal friction characteristics under simulated thrust load

    NASA Technical Reports Server (NTRS)

    Askew, J. W.

    1986-01-01

    An investigation was performed to determine the friction characteristics of the engine gimbal system of the Centaur upper stage rocket. Because the Centaur requires low-gain autopilots in order to meet all stability requirements for some configurations, control performance (response to transients and limit-cycle amplitudes) depends highly on these friction characteristics. Forces required to rotate the Centaur engine gimbal system were measured under a simulated thrust load of 66,723 N (15,000 lb) and in an altitude/thermal environment. A series of tests was performed at three test conditions; ambient temperature and pressure, ambient temperature and vacuum, and cryogenic temperature and vacuum. Gimbal rotation was controlled, and tests were performed in which rotation amplitude and frequency were varied by using triangular and sinusoidal waveforms. Test data revealed an elastic characteristic of the gimbal, independent of the input signal, which was evident prior to true gimbal sliding. The torque required to initiate gimbal sliding was found to decrease when both pressure and temperature decreased. Results from the low amplitude and low frequency data are currently being used in mathematically modeling the gimbal friction characteristics for Centaur autopilot performance studies.

  5. Mars Mission, Viking I on Titan III Centaur Rocket Launch

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Launch of the Mars mission Viking I payload on Titan III Centaur rocket, August 20, 1975. The interplanetary cruise phase of the Viking spacecraft lasted 310 days until Mars orbit insertion. The Viking I orbiter high-gain antenna was put into operation November 12, 1975. The high-gain antenna was repositioned daily to keep the radio beams aimed directly at the Earth.

  6. Radioisotope Electric Propulsion Centaur Orbiter Spacecraft Design Overview

    NASA Technical Reports Server (NTRS)

    Oleson, Steve; McGuire, Melissa; Sarver-Verhey, Tim; Juergens, Jeff; Parkey, Tom; Dankanich, John; Fiehler, Doug; Gyekenyesi, John; Hemminger, Joseph; Gilland, Jim; Colozza, Tony; Packard, Tom; Nguyen, Thahn; Schmitz, Paul; Ostdiek, Paul; Gold, Rob; Lisse, Carey; Hibbits, Karl

    2009-01-01

    Radioisotope electric propulsion (REP) has been shown in past studies to enable missions to outerplanetary bodies including the orbiting of Centaur asteroids. Key to the feasibility for REP missions are long life, low power electric propulsion (EP) devices, low mass radioisotope power systems (RPS) and light spacecraft (S/C) components. In order to determine what are the key parameters for EP devices to perform these REP missions a design study was completed to design an REP S/C to orbit a Centaur in a New Frontiers cost cap. The design shows that an orbiter using several long lived (approximately 200 kg Xenon throughput), low power (approximately 700 W) Hall thrusters teamed with six (150 W each) Advanced Stirling Radioisotope Generators (ASRG) can deliver 60 kg of science instruments to a Centaur in 10 yr within the New Frontiers cost cap. Optimal specific impulses for the Hall thrusters were found to be around 2000 sec with thruster efficiencies over 40%. Not only can the REP S/C enable orbiting a Centaur (when compared to an all chemical mission only capable of flybys) but the additional power from the REP system can be reused to enhance science and simplify communications.

  7. Centaur: A Mobile Dexterous Humanoid for Surface Operations

    NASA Technical Reports Server (NTRS)

    Rehnmark, Fredrik; Ambrose, Robert O.; Goza, S. Michael; Junkin, Lucien; Neuhaus, Peter D.; Pratt, Jerry E.

    2005-01-01

    Future human and robotic planetary expeditions could benefit greatly from expanded Extra-Vehicular Activity (EVA) capabilities supporting a broad range of multiple, concurrent surface operations. Risky, expensive and complex, conventional EVAs are restricted in both duration and scope by consumables and available manpower, creating a resource management problem. A mobile, highly dexterous Extra-Vehicular Robotic (EVR) system called Centaur is proposed to cost-effectively augment human astronauts on surface excursions. The Centaur design combines a highly capable wheeled mobility platform with an anthropomorphic upper body mounted on a three degree-of-freedom waist. Able to use many ordinary handheld tools, the robot could conserve EVA hours by relieving humans of many routine inspection and maintenance chores and assisting them in more complex tasks, such as repairing other robots. As an astronaut surrogate, Centaur could take risks unacceptable to humans, respond more quickly to EVA emergencies and work much longer shifts. Though originally conceived as a system for planetary surface exploration, the Centaur concept could easily be adapted for terrestrial military applications such as de-Gig, surveillance and other hazardous duties.

  8. Centaur: a mobile dexterous humanoid for surface operations

    NASA Astrophysics Data System (ADS)

    Rehnmark, Fredrik; Ambrose, Robert O.; Goza, S. Michael; Junkin, Lucien; Neuhaus, Peter D.; Pratt, Jerry E.

    2005-05-01

    Future human and robotic planetary expeditions could benefit greatly from expanded Extra-Vehicular Activity (EVA) capabilities supporting a broad range of multiple, concurrent surface operations. Risky, expensive and complex, conventional EVAs are restricted in both duration and scope by consumables and available manpower, creating a resource management problem. A mobile, highly dexterous Extra-Vehicular Robotic (EVR) system called Centaur is proposed to cost-effectively augment human astronauts on surface excursions. The Centaur design combines a highly capable wheeled mobility platform with an anthropomorphic upper body mounted on a three degree-of-freedom waist. Able to use many ordinary handheld tools, the robot could conserve EVA hours by relieving humans of many routine inspection and maintenance chores and assisting them in more complex tasks, such as repairing other robots. As an astronaut surrogate, Centaur could take risks unacceptable to humans, respond more quickly to EVA emergencies and work much longer shifts. Though originally conceived as a system for planetary surface exploration, the Centaur concept could easily be adapted for terrestrial military applications such as de-mining, surveillance and other hazardous duties.

  9. [Clinical evaluation of a novel HBsAg quantitative assay].

    PubMed

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

    2007-07-01

    The clinical implication of the hepatitis B surface antigen (HBsAg) concentrations in HBV-infected individuals remains unclear. The aim of this study was to evaluate a novel fully automated Chemiluminescence Enzyme Immunoassay (Sysmex HBsAg quantitative assay) by comparative measurements of the reference serum samples versus two independent commercial assays (Lumipulse f or Architect HBsAg QT). Furthermore, clinical usefulness was assessed for monitoring of the serum HBsAg levels during antiviral therapy. A dilution test using 5 reference-serum samples showed linear correlation curve in range from 0.03 to 2,360 IU/ml. The HBsAg was measured in total of 400 serum samples and 99.8% had consistent results between Sysmex and Lumipulse f. Additionally, a positive linear correlation was observed between Sysmex and Architect. To compare the Architect and Sysmex, both methods were applied to quantify the HBsAg in serum samples with different HBV genotypes/subgenotypes, as well as in serum contained HBV vaccine escape mutants (126S, 145R). Correlation between the methods was observed in results for escape mutants and common genotypes (A, B, C) in Japan. Observed during lamivudine therapy, an increase in HBsAg and HBV DNA concentrations preceded the aminotransferase (ALT) elevation associated with drug-resistant HBV variant emergence (breakthrough hepatitis). In conclusion, reliability of the Sysmex HBsAg quantitative assay was confirmed for all HBV genetic variants common in Japan. Monitoring of serum HBsAg concentrations in addition to HBV DNA quantification, is helpful in evaluation of the response to lamivudine treatment and diagnosis of the breakthrough hepatitis.

  10. Remote Task-level Commanding of Centaur over Time Delay

    NASA Astrophysics Data System (ADS)

    Schreckenghost, Debra; Ngo, Tam; Burridge, Robert; Wang, Lui; Izygon, Michel

    2008-01-01

    Remote operation of robots on the lunar surface by ground controllers poses unique human-robot interaction challenges due to time delay and constrained bandwidth. One strategy for addressing these challenges is to provide task-level commanding of robots by a ground controller. Decision-support tools are being developed at JSC for remote task-level commanding over time-delay. The approach is to provide ground procedures that guide a controller when executing task-level command sequences and aid awareness of the state of command execution in the robot. This approach is being evaluated using the Centaur robot at JSC. The Centaur Central Commander provides a task-level command interface that executes on the robot side of the delay. Decision support tools have been developed for a human Supervisor in the JSC Cockpit to use when interacting with the Centaur Central Commander. Commands to the Central Commander are defined as instructions in a procedure. Sequences of these instructions are grouped into procedures for the Cockpit Supervisor. When a Supervisor is ready to perform a task, a procedure is loaded into the decision support tool. From this tool, the Supervisor can view command sequences and dispatch individual commands to Centaur. Commands are queued for execution on the robot side of the delay. Reliable command sequences can be dispatched automatically upon approval by the Supervisor. The decision support tool provides the Supervisor with feedback about which commands are waiting for execution and which commands have finished. It also informs the Supervisor when a command fails to have its intended effect. Cockpit procedures are defined using the Procedure Representation Language (PRL) developed at JSC for mission operations. The decision support tool is based on a Procedure Sequencer and multi-agent software developed for human-robot interaction. In this paper the approach for remote task-level commanding of robots is described and the results of the evaluation

  11. Customization of Advia 120 thresholds for canine erythrocyte volume and hemoglobin concentration, and effects on morphology flagging results

    PubMed Central

    Grimes, Carolyn N.; Fry, Michael M.

    2014-01-01

    This study sought to develop customized morphology flagging thresholds for canine erythrocyte volume and hemoglobin concentration [Hgb] on the ADVIA 120 hematology analyzer; compare automated morphology flagging with results of microscopic blood smear evaluation; and examine effects of customized thresholds on morphology flagging results. Customized thresholds were determined using data from 52 clinically healthy dogs. Blood smear evaluation and automated morphology flagging results were correlated with mean cell volume (MCV) and cellular hemoglobin concentration mean (CHCM) in 26 dogs. Customized thresholds were applied retroactively to complete blood (cell) count (CBC) data from 5 groups of dogs, including a reference sample group, clinical cases, and animals with experimentally induced iron deficiency anemia. Automated morphology flagging correlated more highly with MCV or CHCM than did blood smear evaluation; correlation with MCV was highest using customized thresholds. Customized morphology flagging thresholds resulted in more sensitive detection of microcytosis, macrocytosis, and hypochromasia than default thresholds. PMID:25477546

  12. Prevalence of hepatitis B surface antigen (HBsAg) in blood donors from Bombay.

    PubMed

    Satoskar, A; Ray, V

    1992-01-01

    Analysis of serum samples from 3104 blood donors from Bombay screened for hepatitis B surface antigen (HBsAg) by ELISA. HBsAg was detected in 4.7% of the subjects. Relatives showed a significantly higher prevalence of HBsAg than volunteer donors. There was no significant association between HBsAg positivity and a particular blood group.

  13. Chiron and the Centaurs: Escapees from the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Stern, Alan; Campins, Humberto

    1996-01-01

    The outer Solar System has long appeared to be a largely empty place, inhabited only by the four giant planets, Pluto and a transient population of comets. In 1977 however, a faint and enigmatic object - 2060 Chiron - was discovered moving on a moderately inclined, strongly chaotic 51-year orbit which takes it from just inside Saturn's orbit out almost as far as that of Uranus. It was not initially clear from where Chiron originated. these objects become temporarily trapped on Centaur-like orbits Following Chiron's discovery, almost 15 years elapsed before other similar objects were discovered; five more have now been identified. Based on the detection statistics implied by these discoveries, it has become clear that these objects belong to a significant population of several hundred (or possibly several thousand) large icy bodies moving on relatively short-lived orbits between the giant planets. This new class of objects, known collectively as the Centaurs, are intermediate in diameter between typical comets (1-20 km) and small icy planets such as Pluto (approx. 2,300 km) and Triton (approx. 2,700 km). Although the Centaurs are interesting in their own right, they have taken on added significance following the recognition that they most probably originated in the ancient reservoir of comets and larger objects located beyond the orbit of Neptune known as the Kuiper belt.

  14. A Herschel-PACS view of 16 Centaurs

    NASA Astrophysics Data System (ADS)

    Duffard, Rene; Pinilla-Alonso, N.; Santos-Sanz, P.; Vilenius, E.; Ortiz, J.; Mueller, T.; Fornasier, S.; Lellouch, E.; Mommert, M.; Pal, A.; Kiss, C.; Mueller, M.; Stansberry, J.; Delsanti, A.; Peixinho, N.

    2013-10-01

    The goal of this work is to characterize a set of Centaurs in terms of their size, albedo, and thermal properties. The Herschel open time key program "TNOs are Cool!'' observed 130 Centaurs and TNOs in 2009-2012. In this particular work we use Herschel/PACS three-band photometry to obtain monochromatic flux densities at 70, 100 and 160 μm. Additionally, we also incorporate Spitzer/MIPS flux densities at 24 and 70 μm when available. We use a consistent method for data reduction and aperture photometry to finally determine sizes and albedos of 16 Centaurs using radiometric techniques. We study the correlations between the size and albedo resulting from our models and other physical (i.e spectral slope) and orbital parameters using a more extended sample (obtained from literature). The final sample comprises 36 objects: 18 Centaurs observed with Herschel/PACS; 10 observed only with Spitzer and 8 SDOs. The first conclusion is that the albedo of the Centaurs is not determined by their orbit. Similarly we do not find any correlation between diameter and orbital parameters. We also find that most of the objects in our sample are dark (pv < 7%) and most of them are small (D < 120km). However, we do not find any correlation between albedo and diameter, in particular for the group of the small objects we can find albedo values homogeneously distributed from 4 - 15%. When it comes to correlation with the color of the objects, we find that the red objects are all small (mean diameter 65 km), while the gray ones are either small or large (mean diameter 120 km). Also, the gray objects seem to be darker, with a mean value of 5.6%, while for the red objects the albedo can vary from 5 to 15%, with a mean value of 8.5%. All of this shows that there are other physical properties (size and albedo distribution) that make differences between the gray and red objects, even if we do not yet have a physical explanation for the origin of this bimodality.

  15. RL10 Engine Ability to Transition from Atlas to Shuttle/Centaur Program

    NASA Technical Reports Server (NTRS)

    Baumeister, Joseph F.

    2015-01-01

    A key launch vehicle design feature is the ability to take advantage of new technologies while minimizing expensive and time consuming development and test programs. With successful space launch experiences and the unique features of both the National Aeronautics and Space Administration (NASA) Space Transportation System (Space Shuttle) and Atlas/Centaur programs, it became attractive to leverage these capabilities. The Shuttle/Centaur Program was created to transition the existing Centaur vehicle to be launched from the Space Shuttle cargo bay. This provided the ability to launch heaver and larger payloads, and take advantage of new unique launch operational capabilities. A successful Shuttle/Centaur Program required the Centaur main propulsion system to quickly accommodate the new operating conditions for two new Shuttle/Centaur configurations and evolve to function in the human Space Shuttle environment. This paper describes the transition of the Atlas/Centaur RL10 engine to the Shuttle/Centaur configurations; shows the unique versatility and capability of the engine; and highlights the importance of ground testing. Propulsion testing outcomes emphasize the value added benefits of testing heritage hardware and the significant impact to existing and future programs.

  16. RL10 Engine Ability to Transition from Atlas to Shuttle/Centaur Program

    NASA Technical Reports Server (NTRS)

    Baumeister, Joseph F.

    2014-01-01

    A key launch vehicle design feature is the ability to take advantage of new technologies while minimizing expensive and time consuming development and test programs. With successful space launch experiences and the unique features of both the National Aeronautics and Space Administration (NASA) Space Transportation System (Space Shuttle) and Atlas/Centaur programs, it became attractive to leverage these capabilities. The Shuttle/Centaur Program was created to transition the existing Centaur vehicle to be launched from the Space Shuttle cargo bay. This provided the ability to launch heaver and larger payloads, and take advantage of new unique launch operational capabilities. A successful Shuttle/Centaur Program required the Centaur main propulsion system to quickly accommodate the new operating conditions for two new Shuttle/Centaur configurations and evolve to function in the human Space Shuttle environment. This paper describes the transition of the Atlas/Centaur RL10 engine to the Shuttle/Centaur configurations; shows the unique versatility and capability of the engine; and highlights the importance of ground testing. Propulsion testing outcomes emphasize the value added benefits of testing heritage hardware and the significant impact to existing and future programs.

  17. The design and fabrication of the Centaur neutral buoyancy trainer and related hardware

    NASA Technical Reports Server (NTRS)

    Ware, Alan S.; Hollingsworth, Michael

    1986-01-01

    Two full scale mockups of the Centaur upper stage were designed, fabricated and delivered to NASA. One was the Centaur Weightless Environment Training Facility (WETF) trainer and the other was the Centaur 1-G mockup. The Centaur upper stage booster is designed to carry the spacecraft Galileo to Jupiter, and the spacecraft Ulysses to an orbit around the Sun after launch from the Space Shuttle. The flight vehicle has several Extravehicular Activity (EVA) contingency tasks that require crew training. This need for crew training generated the requirement for the Centaur WETF crew trainer, which is high fidelity in areas of expected crew interface. During the production of the Centaur WETF crew trainer, the need for a jumper cable from Centaur to the Orbiter was identified. This EVA contingency task would be the installation of a cable from the Orbiter cargo bay sill to various command data boxes on Centaur to allow crew control deployment should a failure occur. This task required the upgrading of volumetric boxes on the trainer to a high fidelity configuration including electrical connector installation and cable routing.

  18. A photometric search for activity among asteroids and Centaurs

    NASA Astrophysics Data System (ADS)

    Sosa Oyarzabal, A.; Mammana, L.; Fernández, J. A.

    2014-07-01

    We present the first results of a long-term observational campaign focused on the detection of activity in selected asteroids and centaurs. Our observational targets are near-Earth asteroids in cometary orbits (cf. [2]), the so called ''main-belt comets'' or ''active asteroids'' (well-known objects as well as potential candidates), and bright centaurs with good orbits, all close to their perihelion passages. In those objects with a former detection of activity, our aim is to contribute to a better physical knowledge of them, and determine, for instance, if the observed activity is transient or permanent. To achieve our goals, we analyzed CCD-filtered images of each observable target acquired with the 2.15-m telescope ''Jorge Sahade'' at CASLEO (San Juan, Argentina), during two runs of three consecutive nights each (during August 2013 and January 2014, respectively). Our study will be completed by future runs with the same instrumentation already assigned to our campaign. As preliminary results, we observed activity in the main-belt comets P/2013 P5 (PANSTARRS) and 133P/(7968) Elst-Pizarro. We also observed the main-belt comet (596) Scheila, which showed an unequivocally stellar appearance. We observed the main-belt comet candidate (3646) Aduatiques (cf. [1]), and noticed in this object a curious feature whose connection to some kind of activity is not well determined yet. We also observed the near-Earth asteroid in cometary orbit 2006 XL_5 (cf. [3]), and the centaurs (281371) 2008 FC_{76}, (332685) 2009 HH_{36}), (382004) 2010 RM_{64}, 2010 XZ_{78}, and 2011 UR_{402}. We have not detected activity in these objects, but an improved analysis is still in progress. %Corresponding author: Andrea Sosa (asosa@fisica.edu.uy)

  19. Formation of Saturn's Rings by Tidal Disruption of a Centaur

    NASA Astrophysics Data System (ADS)

    Dones, Henry C. (Luke); Agnor, C. B.; Asphaug, E.

    2008-05-01

    Planetary rings owe their existence to tidal forces, which frustrate accretion into larger bodies. Models for ring origin include (a) formation in situ, (b) disruption of a moon by cometary impact, and (c) tidal disruption of an interloping Centaur ([1]). [2] applied model (c) to Saturn's rings, basing his results on analytic expressions and taking Chiron to be a typical Saturn-crosser. Many Saturn-crossers have now been discovered, and our understanding of tidal disruption has advanced, particularly through models of the breakup of Comet Shoemaker-Levy 9 (SL9). [3] treated SL9 as a rubble pile, and modeled its disruption with a fast N-body code that included self-gravity and a simple model of collisions. We are using a modified version of this code to follow the tidal disruption of model Centaurs that pass within Saturn's Roche radius. Our simulations have four free parameters: the Centaur's approach velocity to Saturn (v), closest approach distance to Saturn (q), size (r), and rotation state. Mass capture is favored for events with small v and q, large r, and fast direct rotation ([4]). We will estimate the rate of ring formation by tidal disruption, and will constrain the heliocentric orbits of plausible ring parent bodies. Saturn's B Ring may be much more massive than was previously thought ([5],[6]). We will discuss the implications of a more massive ring system for different origin scenarios. We thank the NASA PGG program for support. [1] Pollack JB 1975. Space Sci. Rev. 18, 3. [2]Dones L 1991. Icarus 92, 194. [3] Asphaug E; Benz W 1996. Icarus 121, 225. [4] Richardson DC; Bottke WF; Love SG 1998. Icarus 134, 47. [5] Robbins SJ; Stewart GR; Colwell JE; Lewis MC 2007. DPS meeting 39, abstract 7.05. [6] Stewart GR; Robbins SJ; Colwell JE 2007. DPS meeting 39, abstract 7.06.

  20. WISE Observations of Comets, Centaurs, & Scattered Disk Objects

    NASA Technical Reports Server (NTRS)

    Bauer, J.; Walker, R.; Mainzer, A.; Masiero, J.; Grav, T.; Cutri, R.; Dailey, J.; McMillan, R.; Lisse, C. M.; Fernandez, Y. R.; Meech, K. J.; Pittichova, J.; Tholen, D.; DeBaun, E.; Hand, E.; Blauvelt, E.; Wright, E. L.

    2011-01-01

    The Wide-Field Infrared Survey Explorer (WISE) was luanched on December 14, 2009. WISE imaged more than 99% of the sky in the mid-infrared for a 9-month mission lifetome. In addition to its primary goals of detecting the most luminous infrared galaxies and the nearest brown dwarfs, WISE, detected over 155500 of solar system bodies, 33700 of which were previously unknown. Most of the new objects were main Belt asteriods, and particular emphasis was on the discovery of Near Earth Asteoids. Hundreds of Jupiter Trojans have been imaged by WISE as well. However a substantial number of Centaurs, Scattered Disc Objects (SDOs), & cometary objects, were observed and discovered.

  1. Titan 3E/Centaur D-1T Systems Summary

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A systems and operational summary of the Titan 3E/Centaur D-1T program is presented which describes vehicle assembly facilities, launch facilities, and management responsibilities, and also provides detailed information on the following separate systems: (1) mechanical systems, including structural components, insulation, propulsion units, reaction control, thrust vector control, hydraulic systems, and pneumatic equipment; (2) astrionics systems, such as instrumentation and telemetry, navigation and guidance, C-Band tracking system, and range safety command system; (3) digital computer unit software; (4) flight control systems; (5) electrical/electronic systems; and (6) ground support equipment, including checkout equipment.

  2. Evolution of the Known Centaurs Population - Dynamical and Thermal Pathways

    NASA Astrophysics Data System (ADS)

    Sarid, Gal

    2010-10-01

    The structural and thermal evolution of small Solar system bodies may be strongly dependent on their dynamical history and environment. Objects on planet-crossing orbits are prone to gravitational perturbations that de-stabilize their orbits. Such are the Centaurs, which are the transient population, between the relatively stable trans-Neptunian objects (TNOs) and the short-lived Jupiter family Comets (JFCs). This may indicate that these objects experience intermediate levels of internal processing, at different periods of their lives. Examining the evolution of several these Centaur objects, both in orbital and physical parameters, can help categorize the different states and origin and evolution scenarios in the outer Solar system. Determining the dynamical evolution of each object is achieved through statistical analysis of the results of multiple N-body integrations. This is achieved by using many clones of specific objects, with known orbital elements. Statistics of large clone samples of specific objects yield valuable information about their current states and future fates. Specifically, and with greater importance to thermal evolution, we focus on the dynamical lifetimes, survivability and mean orbital elements. The latter are considered during the relatively stable and non-diffusive phase of orbital evolution. Profiles of temperature, structure and composition are calculated utilizing our robust thermal evolution code several specific objects, which represent slightly varying dynamical groups, and for different orbits of the same object, which represent specific orbital evolution pathways. This has an influence on the internal stratified structure, through an adapting thermal response of the nucleus.

  3. Spitzer Thermal Radiometry of Kuiper Belt Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Stansberry, John; Mueller, Michael; Cruikshank, Dale; Grundy, Will; Noll, Keith; Spencer, John; Trilling, David

    2006-05-01

    About 10 Kuiper Belt Objects (KBOs) have been detected at both 24 and 70um with Spitzer at high enough signal-to-noise ratio (SNR) to allow determinations of their of their albedos and diameters. While these physical parameters can be estimated from a detection at a single thermal wavelength, they are then subject to large uncertainties stemming from the assumed model for the temperature distribution on the surface. A two-color thermal detection eliminates most of the model uncertainty, and the accuracy of the derived parameters is then limited primarily by measurement and calibration errors. An added benefit of a two-color detection is that it yields some information about the temperature distribution, and therefore about the thermal parameter (or thermal inertia, if the rotation period is known) of the surface materials. We propose to use MIPS to detect 8 KBOs and 8 Centaurs at both 24 and 70um, at SNR > 5 in both bands. We base our predictions of their thermal emission, our sensitivity estimates, and our observing strategy on our past observations of KBOs with Spitzer. Our sample size is chosen to double the sample of both KBOs and Centaurs with two-color data, significantly improving our knowledge of their physical parameters, and providing enough objects to allow us to begin to look for trends in albedo vs. size and color.

  4. Transport and Use of a Centaur Second Stage in Space

    NASA Technical Reports Server (NTRS)

    Strong, James M.; Morgowicz, Bernard; Drucker, Eric; Tompkins, Paul D.; Kennedy, Brian; Barber, Robert D,; Luzod, Louie T.; Kennedy, Brian Michael; Luzod, Louie T.

    2010-01-01

    As nations continue to explore space, the desire to reduce costs will continue to grow. As a method of cost reduction, transporting and/or use of launch system components as integral components of missions may become more commonplace in the future. There have been numerous scenarios written for using launch vehicle components (primarily space shuttle used external tanks) as part of flight missions or future habitats. Future studies for possible uses of launch vehicle upper stages might include asteroid diverter using gravity orbital perturbation, orbiting station component, raw material at an outpost, and kinetic impactor. The LCROSS (Lunar CRater Observation and Sensing Satellite) mission was conceived as a low-cost means of determining whether water exists at the polar regions of the moon. Manifested as a secondary payload with the LRO (Lunar Reconnaissance Orbiter) spacecraft aboard an Atlas V launch vehicle, LCROSS guided its spent Centaur Earth Departure Upper Stage (EDUS) into the lunar crater Cabeu's, as a kinetic impactor. This paper describes some of the challenges that the LCROSS project encountered in planning, designing, launching with and carrying the Centaur upper stage to the moon.

  5. Titan 4B/Centaur/Cassini Service Tower Rollaway

    NASA Technical Reports Server (NTRS)

    1997-01-01

    KENNEDY SPACE CENTER, FLA. -- At Launch Complex 40 on Cape Canaveral Air Station, the Mobile Service Tower is rolled away from the Titan IVB/Centaur carrying the Cassini spacecraft, marking a major milestone in the launch countdown sequence. Retraction of the structure began about an hour later than scheduled due to minor problems with ground support equipment. The countdown clock for the Cassini mission began ticking earlier today at the T-26-hour mark. Other upcoming prelaunch milestones include activation of the final launch sequence for the Cassini spacecraft at the T-180-minute mark in the countdown, to be followed about an hour later by initiation of loading of the Titan IVB's Centaur stage with its complement of liquid hydrogen and liquid oxygen. Liftoff of Cassini on the journey to Saturn and its moon Titan is slated to occur during a window opening at 4:55 a.m. EDT, Oct. 13, and extending through 7:15 a.m.

  6. [Haemolysis and turbidity influence on three analysis methods of quantitative determination of total and conjugated bilirubin on ADVIA 1650].

    PubMed

    Gobert De Paepe, E; Munteanu, G; Schischmanoff, P O; Porquet, D

    2008-01-01

    Plasma bilirubin testing is crucial to prevent the occurrence of neonatal kernicterus. Haemolysis may occur during sampling and interfere with bilirubin determination. Moreover, lipidic infusions may induce plasma lipemia and also interfere with bilirubin measurement. We evaluated the interference of haemolysis and lipemia with three methods of total and direct bilirubin measurement adaptated on an Advia 1650 analyser (Siemens Medical Solutions Diagnostics) : Synermed (Sofibel), Bilirubin 2 (Siemens) and Bilirubin Auto FS (Diasys). The measurement of total bilirubin was little affected by haemolysis with all three methods. The Bilirubin 2 (Siemens) method was the less sensitive to haemolysis even at low bilirubin levels. The measurement of conjugated bilirubin was significantly altered by low heamoglobin concentrations for Bilirubin Auto FS(R) (30 microM or 0,192 g/100 mL haemoglobin) and for Synermed (60 microM or 0,484 g/100 mL haemoglobin). In marked contrast, we found no haemoglobin interference with the Direct Bilirubin 2 reagent which complied with the method validation criteria from the French Society for Biological Chemistry. The lipemia up to 2 g/L of Ivelip did not affect neither the measurement of total bilirubin for all three methods nor the measurement of conjugated bilirubin with the Diasys and Siemens reagents. However, we observed a strong interference starting at 0,5 g/L of Ivelip with the Synermed reagent. Our data suggest that both Siemens and Diasys methods allow to measure accurately total and conjugated bilirubin in hemolytic and lipemic samples, nevertheless, the Siemens methodology is less affected by these interferences.

  7. Effects of non-gravitational forces on orbital evolution of active Centaurs

    NASA Astrophysics Data System (ADS)

    Churyumov, Klim; Kovalenko, Nataliya

    2016-07-01

    Currently there are 26 active Centaurs known among 121 discovered .In the present study we have investigated the influence of cometary activity on their orbital evolution by using orbital evolution integrators. Since there is no information on exact values of non-gravitational forces for these cometary Centaurs, because of their large heliocentric distances, we assumed their non-gravitational forces as the one for comet Halley with coefficient of 1/r^{2}, where r is perihelion distance. As a result we got the differences in perihelion passage dates for active Centaurs and differences in their perihelion distances during one period around the Sun and longer time-span.

  8. The cyclotron energization through auroral wave experiments (CENTAUR 2B)

    NASA Technical Reports Server (NTRS)

    Winningham, J. D.

    1992-01-01

    The CENTAUR 2B mission, a dual payload program, is in many aspects the same as the previous missions from Cape Perry and Norway in 1985. It was planned that these payloads would be launched from Andoya, Norway, Nov. 1989 from the Universal II launcher. The payloads are identical, but would have been launched at different azimuths as far north and as far west as possible. Particle experiments include the angular resolving energy analyzer (AREA), the fast ion mass spectrometer (FIMS), the spectrographic particle images (SPI), and finally, the differential ion flux probe (DIFP). SwRI was responsible for the scientific payload, which includes the power supplies, the power supply interfacing, the manipulating of the data from the instruments to format it for the telemetry system, all mechanical structure and restraint mechanisms, and the payload subskin. The status of the various components of this program is given.

  9. Assessing the contribution of centaur impacts to ice giant luminosities

    NASA Astrophysics Data System (ADS)

    Dodson-Robinson, Sarah E.

    2016-01-01

    Voyager 2 observations revealed that Neptune's internal luminosity is an order of magnitude higher than that of Uranus. If the two planets have similar interior structures and cooling histories, Neptune's luminosity can only be explained by invoking some energy source beyond gravitational contraction. This paper investigates whether centaur impacts could provide the energy necessary to produce Neptune's luminosity. The major findings are (1) that impacts on both Uranus and Neptune are too infrequent to provide luminosities of order Neptune's observed value, even for optimistic impact-rate estimates and (2) that Uranus and Neptune rarely have significantly different impact-generated luminosities at any given time. Uranus and Neptune most likely have structural differences that force them to cool and contract at different rates.

  10. New Outburst of Centaur Comet (60558) 174P/Echeclus

    NASA Astrophysics Data System (ADS)

    Choi, Young-Jun; Ishiguro, Masateru; Moon, Hong-Kyu

    2015-03-01

    We report observations of new outburst of Centaur (60558) 174P/Echeclus, using Suprime-Cam of Subaru tele-scope. The outburst was detected by Jager on May 30, 2011 (Jaeger et al., 2011). We made several follow-up observations for this outburst with 1m telescope at Mt. Lemon Optical Astronomy Observatory located in US and 60cm telescope at Sobaeksan Optical Astronomy Observatory in Korea. The very first presence of coma around (60558) 2000 EC98 has been detected by Choi and Weissman (2006) on 2005 December 30.50 UT with the Palomar 5m telescope. Soon after, the object was given the periodic comet designa-tion 174P/Echeclus. We will present the characterstics and discuss the reason of this recursive outburst.

  11. Spectral Models of Kuiper Belt Objects and Centaurs

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale; Ore, Christina M. Dalle

    2003-01-01

    We present models of the spectral reflectances of groups of outer Solar System objects defined primarily by their colors in the spectral region 0.4 -1.2 microns, and which have geometric albedo 0.04 at wavelength 0.55 microns. Our models of the groups with the strongest reflectance gradients (reddest colors) use combinations of organic tholins. We test the hypothesis that metal-reddened igneous rock-forming minerals contribute to the red colors of Centaurs and KBOs by using the space-weathered lunar soil as one of the components of our models. We find that our models can admit the presence of moderate amounts of space-weathered (metal-reddened) minerals, but that they do not require this material to achieve the red colors of the reddest outer Solar System bodies. Our models with organic tholins are consistent with the results of other investigators.

  12. Application of a Newly Developed High-Sensitivity HBsAg Chemiluminescent Enzyme Immunoassay for Hepatitis B Patients with HBsAg Seroclearance

    PubMed Central

    Shinkai, Noboru; Matsuura, Kentaro; Sugauchi, Fuminaka; Watanabe, Tsunamasa; Murakami, Shuko; Iio, Etsuko; Ogawa, Shintaro; Nojiri, Shunsuke; Joh, Takashi

    2013-01-01

    We modified and automated a highly sensitive chemiluminescent enzyme immunoassay (CLEIA) for surface antigen (HBsAg) detection using a combination of monoclonal antibodies, each for a specific epitope of HBsAg, and by improving an earlier conjugation technique. Of 471 hepatitis B virus (HBV) carriers seen in our hospital between 2009 and 2012, 26 were HBsAg seronegative as determined by the Abbott Architect assay. The Lumipulse HBsAg-HQ assay was used to recheck those 26 patients who demonstrated seroclearance by the Abbott Architect assay. The performance of the Lumipulse HBsAg-HQ assay was compared with that of a quantitative HBsAg detection system (Abbott Architect) and the Roche Cobas TaqMan HBV DNA assay (CTM) (lower limit of detection, 2.1 log copies/ml) using blood serum samples from patients who were determined to be HBsAg seronegative by the Abbott Architect assay. Ten patients had spontaneous HBsAg loss. Of 8 patients treated with nucleotide analogues (NAs), two were HBsAg seronegative after stopping lamivudine therapy and 6 were HBsAg seronegative during entecavir therapy. Eight acute hepatitis B (AH) patients became HBsAg seronegative. Of the 26 patients, 16 were HBsAg positive by the Lumipulse HBsAg-HQ assay but negative by the Abbott Architect assay. The differences between the two assays in terms of detectable HBsAg persisted over the long term in the spontaneous loss group (median, 10 months), the NA-treated group (2.5 months), and the AH group (0.5 months). In 9 patients, the Lumipulse HBsAg-HQ assay detected HBsAg when HBV DNA was negative by the CTM assay. HBsAg was also detected by the Lumipulse HBsAg-HQ assay in 4 patients with an anti-HBs concentration of >10 mIU/ml, 3 of whom had no HBsAg escape mutations. The automatic, highly sensitive HBsAg CLEIA Lumipulse HBsAg-HQ is a convenient and precise assay for HBV monitoring. PMID:23946517

  13. Application of a newly developed high-sensitivity HBsAg chemiluminescent enzyme immunoassay for hepatitis B patients with HBsAg seroclearance.

    PubMed

    Shinkai, Noboru; Matsuura, Kentaro; Sugauchi, Fuminaka; Watanabe, Tsunamasa; Murakami, Shuko; Iio, Etsuko; Ogawa, Shintaro; Nojiri, Shunsuke; Joh, Takashi; Tanaka, Yasuhito

    2013-11-01

    We modified and automated a highly sensitive chemiluminescent enzyme immunoassay (CLEIA) for surface antigen (HBsAg) detection using a combination of monoclonal antibodies, each for a specific epitope of HBsAg, and by improving an earlier conjugation technique. Of 471 hepatitis B virus (HBV) carriers seen in our hospital between 2009 and 2012, 26 were HBsAg seronegative as determined by the Abbott Architect assay. The Lumipulse HBsAg-HQ assay was used to recheck those 26 patients who demonstrated seroclearance by the Abbott Architect assay. The performance of the Lumipulse HBsAg-HQ assay was compared with that of a quantitative HBsAg detection system (Abbott Architect) and the Roche Cobas TaqMan HBV DNA assay (CTM) (lower limit of detection, 2.1 log copies/ml) using blood serum samples from patients who were determined to be HBsAg seronegative by the Abbott Architect assay. Ten patients had spontaneous HBsAg loss. Of 8 patients treated with nucleotide analogues (NAs), two were HBsAg seronegative after stopping lamivudine therapy and 6 were HBsAg seronegative during entecavir therapy. Eight acute hepatitis B (AH) patients became HBsAg seronegative. Of the 26 patients, 16 were HBsAg positive by the Lumipulse HBsAg-HQ assay but negative by the Abbott Architect assay. The differences between the two assays in terms of detectable HBsAg persisted over the long term in the spontaneous loss group (median, 10 months), the NA-treated group (2.5 months), and the AH group (0.5 months). In 9 patients, the Lumipulse HBsAg-HQ assay detected HBsAg when HBV DNA was negative by the CTM assay. HBsAg was also detected by the Lumipulse HBsAg-HQ assay in 4 patients with an anti-HBs concentration of >10 mIU/ml, 3 of whom had no HBsAg escape mutations. The automatic, highly sensitive HBsAg CLEIA Lumipulse HBsAg-HQ is a convenient and precise assay for HBV monitoring.

  14. (12929) 1999 TZ1 : A Portait Of The Closest Centaur

    NASA Astrophysics Data System (ADS)

    Moullet, Arielle; Lellouch, E.; Moreno, R.; Ortiz, J. L.; Duffard, R.; Vernazza, P.; Doressoundiram, A.

    2007-10-01

    Small body (12929) 1999 TZ1, which is located on a typical Jupiter Trojan orbit at a=5.21 UA, is classified as a Centaur due to its short dynamical lifetime. It is hence the closest and one of the brightest members of this population. We report on millimetric flux measurements, as well as visible photometry and visible-near infrared spectroscopy performed on February-May 2007 on this object. The light-curve obtained at the Calar Alto 1m telescope, Spain, reveals a short rotating double-peaked period of 10.438 hours, with a low 0.1 magnitude peak-to-peak amplitude. Millimetric flux obtained with the IRAM-30m antenna facility at Pico Veleta, Spain, using MAMBO bolometer, was of 1.4 +/- 0.3 mJy. This flux and the visual magnitude (app. V=16.4) were interpreted through a standard fast rotator thermal model, which estimates the objet diameter of 50 km. Geometrical albedo is also determined at p 0.085, much higher than the typical Trojan albedo (0.04), but fully consistent with Centaurs albedo distribution. In addition, we obtained the reflectance spectrum of 1999 TZ1 at the Nasa Infrared Telescope Facility (IRTF) located at the summit of Mauna Kea, Hawai`i using the SPEX instrument. The 0.7-2.5 µm spectrum shows a reddish slope with no obvious spectral features, which is quite comparable with the spectra of Jupiter Trojans or D-type asteroids. Further interpretation in terms of shape determination and thermal modeling will be presented.

  15. TNO and Centaur Diameters, Albedos, and Densities V4.0

    NASA Astrophysics Data System (ADS)

    Johnston, W. R.

    2016-07-01

    This data set is a compilation of published diameters, albedos, and densities for Transneptunian Objects (TNOs) and Centaurs. A total of 190 objects are listed, many with more than one entry. This version covers published values through 31 March 2016.

  16. Taming Liquid Hydrogen: The Centaur Upper Stage Rocket, 1958-2002

    NASA Technical Reports Server (NTRS)

    Dawson, Virginia P.; Bowles, Mark D.

    2004-01-01

    During its maiden voyage in May 1962, a Centaur upper stage rocket, mated to an Atlas booster, exploded 54 seconds after launch, engulfing the rocket in a huge fireball. Investigation revealed that Centaur's light, stainless-steel tank had split open, spilling its liquid-hydrogen fuel down its sides, where the flame of the rocket exhaust immediately ignited it. Coming less than a year after President Kennedy had made landing human beings on the Moon a national priority, the loss of Centaur was regarded as a serious setback for the National Aeronautics and Space Administration (NASA). During the failure investigation, Homer Newell, Director of Space Sciences, ruefully declared: "Taming liquid hydrogen to the point where expensive operational space missions can be committed to it has turned out to be more difficult than anyone supposed at the outset." After this failure, Centaur critics, led by Wernher von Braun, mounted a campaign to cancel the program. In addition to the unknowns associated with liquid hydrogen, he objected to the unusual design of Centaur. Like the Atlas rocket, Centaur depended on pressure to keep its paper-thin, stainless-steel shell from collapsing. It was literally inflated with its propellants like a football or balloon and needed no internal structure to give it added strength and stability. The so-called "pressure-stabilized structure" of Centaur, coupled with the light weight of its high- energy cryogenic propellants, made Centaur lighter and more powerful than upper stages that used conventional fuel. But, the critics argued, it would never become the reliable rocket that the United States needed.

  17. Comparison of Serum HBsAg Quantitation by Four Immunoassays, and Relationships of HBsAg Level with HBV Replication and HBV Genotypes

    PubMed Central

    Tuaillon, Edouard; Mondain, Anne-Marie; Nagot, Nicolas; Ottomani, Laure; Kania, Dramane; Nogue, Erika; Rubbo, Pierre-Alain; Pageaux, Georges-Philippe; Van de Perre, Philippe; Ducos, Jacques

    2012-01-01

    Background The decline in hepatitis B virus surface antigen (HBsAg) may be an early predictor of the viral efficacy of Hepatitis B virus (HBV) therapy. The HBsAg levels obtained by different immunoassays now need comparing and the relationships between levels of HBsAg and HBV DNA alongside HBsAg and genotype must be evaluated. Methodology/Principal Findings HBsAg levels were compared among 80 patients using the Abbott Architect assay, a commercial immunoassay approved for HBsAg detection and quantitation, and three other assays derived from immunoassays approved for HBsAg detection (manufactured by Diasorin, Bio-Rad and Roche). Good correlation was found between the Abbot vs. Diasorin, Bio-Rad and Roche assays with narrow 95% limits of agreement and small mean differences: −0.06 to 0.11, −0.09 log10 IU/mL; −0.57 to 0.64, −0.04 log10 IU/mL; −0.09 to 0.45, −0.27 log10 IU/mL, respectively. These agreements were not affected by genotypes A or D. HBsAg was weakly correlated with HBV DNA, whatever the HBsAg assay used: Abbott, ρ = 0.36 p = 0.001, Diasorin ρ = 0.34, p = 0.002; Bio-Rad ρ = 0.37, p<0.001; or Roche ρ = 0.41, p<0.001. This relationship between levels of HBsAg and HBV DNA seemed to depend on genotypes. Whereas HBsAg (Abbott assay) tended to correlate with HBV DNA for genotype A (ρ = 0.44, p = 0.02), no such correlation was significant for genotypes D (ρ = 0.29, p = 0.15). Conclusion/Significance The quantitation of HBsAg in routine clinical samples is comparable between the reference assay and the adapted assays with acceptable accuracy limits, low levels of variability and minimum discrepancy. While HBsAg quantitation is not affected by HBV genotype, the observed association between levels of HBsAg and HBV DNA seems genotype dependent. PMID:22403628

  18. A long term study of Centaur 174P/Echeclus

    NASA Astrophysics Data System (ADS)

    Rousselot, Philippe; Korsun, Pavlo; Kulyk, Irina; Petit, Jean-Marc; Guilbert-Lepoutre, Aurélie

    2015-11-01

    Centaur 174P/Echeclus was discovered by the Spacewatch program on March 3, 2000 and initially labelled (60558) 2000 EC 98 . On December 30, 2005, a surprising cometary outburst was discovered with the 5-m Mount Palomar Observatory telescope. This outburst corresponded to a change in the overall visual magnitude from about 21 to about 14. At that time (60558) 2000 EC 98 was located at 13.07 au to the Sun and was subsequently renamed with a cometary designation. This outburst lasted a few months and, one year later, no coma could be detected. Another secondary outburst happened in 2011 and lasted also a few months. This target was at its perihelion (5.82 au) on April 22, 2015.We present new observational data obtained with the 2.5-m Nordic Optical Telescope during the 2011 outburst and in July 2013, and with the robotic 2-m Liverpool telescope on April 27, 2014, August 13, 2014 and June 1, 2015. We also found archive observational data obtained on December 22, 2005.These archive images point out the extremely high level of the 174P/Echeclus activity during the first outburst. The R-magnitude and Afrho parameter of the target were estimated to 14.8 and 56000±3000 cm respectively. During the second outburst, in 2011, the activity level of the Centaur was lower, the R-Afrho parameters were 1200±100 cm and 480±70 cm in June and July respectively. The dust production rates needed to produce the observed comae were approximately 700 kg.s-1 in 2005 and between 10 and 20 kg.s-1 in 2011 assuming the average grain geometric albedo of 0.1 and low outflow velocities of the dust, less than 10 m.s-1. A possible scenario of the dust coma formation for the first outburst will also be proposed using a Monte Carlo modeling.Before the outburst the lightcurve amplitude was 0.24 magnitude in the R-band with a rotation period of 26.80 h (if a double-peaked lightcurve is assumed). The observational data obtained after the outburst with the NOT do not permit to detect any clear variation

  19. [Diagnostic value of the quantitative HBsAg determination in hepatitis B infections].

    PubMed

    van Helden, J; Weiskirchen, R

    2016-04-01

    Introduction of systematic hepatitis B vaccination has lead to a strong decrease of new infections, but there are still a high numbers of chronically infected persons suffering on long-term complications. Using quantitative assays for the determination of HbsAg (qHBsAg) has improved our understanding of chronic hepatitis B (CHB). The concentrations of HBsAg are strongly varying through the different stages of infection. The quantitative determination of HBsAg does not only yield in additional information to the infection activity, but also provides data for an improved follow up independent from the virus load. As to the prediction of disease progression, low-viremic carriers with high HbsAg levels have been shown to be at higher risk of HBeAg negative hepatitis, cirrhosis and hepatocellular carcinoma (HCC). Although, quantitative HBsAg determination has been widely used in CHB patients receiving pegylated interferon therapy, the HbsAg decline is slow compared to HBV-DNA levels during nucleos(t)ide analogue (NUC) therapy. However a rapid HbsAg decline during NUC therapy may identify patients who will finally clear HbsAg. A 6- to 12-monthly assessment of HbsAg level could be considered during NUC therapy. Taking these lines of evidence together, qHBsAg can complement HBV-DNA levels to optimize the management of CHB patients.

  20. Centaur Test Bed (CTB) for Cryogenic Fluid Management

    NASA Technical Reports Server (NTRS)

    Sakla, Steven; Kutter, Bernard; Wall, John

    2006-01-01

    Future missions such as NASA s space exploration vision and DOD satellite servicing will require significant increases in the understanding and knowledge of space based cryogenic fluid management (CFM), including the transfer and storage of cryogenic fluids. Existing CFM capabilities are based on flight of upper stage cryogenic vehicles, scientific dewars, a few dedicated flight demonstrations and ground testing. This current capability is inadequate to support development of the CEV cryogenic propulsion system, other aspects of robust space exploration or the refueling of satellite cryo propulsion systems with reasonable risk. In addition, these technologies can provide significant performance increases for missions beyond low-earth orbit to enable manned missions to the Moon and beyond. The Centaur upper-stage vehicle can provide a low cost test platform for performing numerous flight demonstrations of the full breadth of required CFM technologies to support CEV development. These flight demonstrations can be performed as secondary mission objectives using excess LH2 and/or LO2 from the main vehicle propellant tanks following primary spacecraft separation at minimal cost and risk.

  1. A ring system detected around the Centaur (10199) Chariklo.

    PubMed

    Braga-Ribas, F; Sicardy, B; Ortiz, J L; Snodgrass, C; Roques, F; Vieira-Martins, R; Camargo, J I B; Assafin, M; Duffard, R; Jehin, E; Pollock, J; Leiva, R; Emilio, M; Machado, D I; Colazo, C; Lellouch, E; Skottfelt, J; Gillon, M; Ligier, N; Maquet, L; Benedetti-Rossi, G; Ramos Gomes, A; Kervella, P; Monteiro, H; Sfair, R; El Moutamid, M; Tancredi, G; Spagnotto, J; Maury, A; Morales, N; Gil-Hutton, R; Roland, S; Ceretta, A; Gu, S-h; Wang, X-b; Harpsøe, K; Rabus, M; Manfroid, J; Opitom, C; Vanzi, L; Mehret, L; Lorenzini, L; Schneiter, E M; Melia, R; Lecacheux, J; Colas, F; Vachier, F; Widemann, T; Almenares, L; Sandness, R G; Char, F; Perez, V; Lemos, P; Martinez, N; Jørgensen, U G; Dominik, M; Roig, F; Reichart, D E; LaCluyze, A P; Haislip, J B; Ivarsen, K M; Moore, J P; Frank, N R; Lambas, D G

    2014-04-01

    Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur--that is, one of a class of small objects orbiting primarily between Jupiter and Neptune--with an equivalent radius of 124 ±  9 kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites.

  2. A ring system detected around the Centaur (10199) Chariklo.

    PubMed

    Braga-Ribas, F; Sicardy, B; Ortiz, J L; Snodgrass, C; Roques, F; Vieira-Martins, R; Camargo, J I B; Assafin, M; Duffard, R; Jehin, E; Pollock, J; Leiva, R; Emilio, M; Machado, D I; Colazo, C; Lellouch, E; Skottfelt, J; Gillon, M; Ligier, N; Maquet, L; Benedetti-Rossi, G; Ramos Gomes, A; Kervella, P; Monteiro, H; Sfair, R; El Moutamid, M; Tancredi, G; Spagnotto, J; Maury, A; Morales, N; Gil-Hutton, R; Roland, S; Ceretta, A; Gu, S-h; Wang, X-b; Harpsøe, K; Rabus, M; Manfroid, J; Opitom, C; Vanzi, L; Mehret, L; Lorenzini, L; Schneiter, E M; Melia, R; Lecacheux, J; Colas, F; Vachier, F; Widemann, T; Almenares, L; Sandness, R G; Char, F; Perez, V; Lemos, P; Martinez, N; Jørgensen, U G; Dominik, M; Roig, F; Reichart, D E; LaCluyze, A P; Haislip, J B; Ivarsen, K M; Moore, J P; Frank, N R; Lambas, D G

    2014-04-01

    Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur--that is, one of a class of small objects orbiting primarily between Jupiter and Neptune--with an equivalent radius of 124 ±  9 kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites. PMID:24670644

  3. Centaur Standard Shroud (CSS) Heated Altitude Jettison Tests

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Altitude jettison tests, at a pressure of 20 torr (0.39 psia), were performed on the Centaur Standard Shroud (CSS) in a 100-foot diameter vacuum chamber. These jettison tests were part of a series of flight qualification tests which were performed on the new CSS system in preparation for the Helios and Viking missions. The first two tests subjected the CSS to a thermal cycle which simulated aerodynamic heating during ascent flight and the third test was performed at altitude pressure and in ambient temperature conditions. The purpose of the ambient temperature test was to provide base line data by which the separate machanical and thermal factors that influence jettison performance could be evaluated individually. The CSS was successfully jettisoned in each of the three tests. Also, thermal, stress, and structural deflection data were obtained which verified the analytical predictions of CSS response to flight environmental conditions and performance during jettison. In addition, much important information was obtained on critical CSS-to-payload clearance losses due to shell motions prior to and during jettison. The effectiveness of the separation system was successfully demonstrated at maximum flight temperatures.

  4. Reflections on Centaur Upper Stage Integration by the NASA Lewis (Glenn) Research Center

    NASA Technical Reports Server (NTRS)

    Graham, Scott R.

    2014-01-01

    The NASA Glenn (then Lewis) Research Center (GRC) led several expendable launch vehicle (ELV) projects from 1963 to 1998, most notably the Centaur upper stage. These major, comprehensive projects included system management, system development, integration (both payload and stage), and launch operations. The integration role that GRC pioneered was truly unique and highly successful. Its philosophy, scope, and content were not just invaluable to the missions and vehicles it supported, but also had significant Agencywide benefits. An overview of the NASA Lewis Research Center (now the NASA Glenn Research Center) philosophy on ELV integration is provided, focusing on Atlas/Centaur, Titan/Centaur, and Shuttle/Centaur vehicles and programs. The necessity of having a stable, highly technically competent in-house staff is discussed. Significant depth of technical penetration of contractor work is another critical component. Functioning as a cohesive team was more than a concept: GRC senior management, NASA Headquarters, contractors, payload users, and all staff worked together. The scope, content, and history of launch vehicle integration at GRC are broadly discussed. Payload integration is compared to stage development integration in terms of engineering and organization. Finally, the transition from buying launch vehicles to buying launch services is discussed, and thoughts on future possibilities of employing the successful GRC experience in integrating ELV systems like Centaur are explored.

  5. Reflections on Centaur Upper Stage Integration by the NASA Lewis (Glenn) Research Center

    NASA Technical Reports Server (NTRS)

    Graham, Scott R.

    2015-01-01

    The NASA Glenn (then Lewis) Research Center (GRC) led several expendable launch vehicle (ELV) projects from 1963 to 1998, most notably the Centaur upper stage. These major, comprehensive projects included system management, system development, integration (both payload and stage), and launch operations. The integration role that GRC pioneered was truly unique and highly successful. Its philosophy, scope, and content were not just invaluable to the missions and vehicles it supported, but also had significant Agency-wide benefits. An overview of the NASA Lewis Research Center (now the NASA Glenn Research Center) philosophy on ELV integration is provided, focusing on Atlas/Centaur, Titan/Centaur, and Shuttle/Centaur vehicles and programs. The necessity of having a stable, highly technically competent in-house staff is discussed. Significant depth of technical penetration of contractor work is another critical component. Functioning as a cohesive team was more than a concept: GRC senior management, NASA Headquarters, contractors, payload users, and all staff worked together. The scope, content, and history of launch vehicle integration at GRC are broadly discussed. Payload integration is compared to stage development integration in terms of engineering and organization. Finally, the transition from buying launch vehicles to buying launch services is discussed, and thoughts on future possibilities of employing the successful GRC experience in integrating ELV systems like Centaur are explored.

  6. Autonomous rendezvous and docking operations of unmanned expendable cargo transfer vehicles (e.g. Centaur) with Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Emmet, Brian R.

    1991-01-01

    This paper describes the results of the feasibility study using Centaur or other CTV's to deliver payloads to the Space Station Freedom (SSF). During this study was examined the requirements upon unmanned cargo transfer stages (including Centaur) for phasing, rendezvous, proximity operations and docking/berthing (capture).

  7. The evolution of computer monitoring of real time data during the Atlas Centaur launch countdown

    NASA Technical Reports Server (NTRS)

    Thomas, W. F.

    1981-01-01

    In the last decade, improvements in computer technology have provided new 'tools' for controlling and monitoring critical missile systems. In this connection, computers have gradually taken a large role in monitoring all flights and ground systems on the Atlas Centaur. The wide body Centaur which will be launched in the Space Shuttle Cargo Bay will use computers to an even greater extent. It is planned to use the wide body Centaur to boost the Galileo spacecraft toward Jupiter in 1985. The critical systems which must be monitored prior to liftoff are examined. Computers have now been programmed to monitor all critical parameters continuously. At this time, there are two separate computer systems used to monitor these parameters.

  8. Study of liquid and vapor flow into a Centaur capillary device

    NASA Technical Reports Server (NTRS)

    Blatt, M. H.; Risberg, J. A.

    1979-01-01

    The following areas of liquid and vapor flow were analyzed and experimentally evaluated; 1) the refilling of capillary devices with settled liquid, and 2) vapor flow across wetted screens. These investigations resulted in: 1) the development of a versatile computer program that was successfully correlated with test data and used to predict Centaur D-1S LO2 and LH2 start basket refilling; 2) the development of a semi-empirical model that was only partially correlated with data due to difficulties in obtaining repeatable test results. Also, a comparison was made to determine the best propellant management system for the Centaur D-1S vehicle. The comparison identified the basline Centaur D-1S system (using pressurization, boost pumps and propellant settling) as the best candidate based on payload weight penalty. However, other comparison criteria and advanced mission condition were identified where pressure fed systems, thermally subcooled boost pumps and capillary devices would be selected as attractive alternatives.

  9. MARINER 10 LAUNCH VEHICLE ATLAS CENTAUR 34 UNDERGOES TANKING TEST AT LAUNCH COMPLEX 36B

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Atlas Centaur 34, undergoes tanking test on NASA Complex 36B at Cape Kennedy, Fla. Atlas Centaur 34 is under preparation to launch history's first duel-planet flight, the Mariner mission to Venus and Mercury, scheduled for early November. With all events going as planned, the Mariner spacecraft will fly by Venus in early February, 1974, and reach Mercury in late march, 1974. The spacecraft, Mariner 10, will carry two television cameras to photograph the planets, and six other scientific experiments to return planetary and interplanetary data back to Earth.

  10. Measurement of Centaur/Orbiter multiple reaction forces in a full-scale test rig

    NASA Technical Reports Server (NTRS)

    Mole, Philip J.; Griffin, Stan A.

    1986-01-01

    A multiple component load cell for measuring load is described, and its capability and reliability are evaluated by utilizing it to measure the reaction forces between the Centaur and Centaur Support Structure. The system employs 11 six-component balances in a single test rig to react a combination of loads. The vehicle and balance loads, procedures for fabricating each balance, and the assembly of the balances are discussed. The calibration and testing of the balances are examined. It is noted that the multiple component load cell system is a cost-effective method for obtaining an accurate measurement of friction effects and primary loads.

  11. A continuous follow-up of Centaurs, and dormant comets: looking for cometary activity.

    NASA Astrophysics Data System (ADS)

    Trigo-Rodríguez, J. M.; García Melendo, E.; García-Hernández, D. A.; Davidsson, B.; Sánchez, A.; Rodríguez, D.

    2008-09-01

    MOTIVATION FOR THIS MONITORING To better understand the origin, nature and evolution of the Kuiper Belt Objects (hereafter KBOs) it is needed a characterization of the physical properties of these primitive bodies. We expect that these remote and pristine bodies are rich in ice and other volatiles. They also probably played an important role in the enrichment in volatiles of the solar system inner planets. In fact, the dynamic patterns and the structure of the KB, populated by large ice-rich bodies probably subjected to complex collisional histories are opening new questions. They are for example suspicious of being the source of Centaurs, and Jupiter Family Comets (JFCs) [1]. In fact, the present day known Centaurs are ice-rich bodies that follow unstable orbits crossing those of Saturn, Uranus, and Neptune. On the other hand, modelling of JFCs evolution suggests that some are able to get incorporated into the NEO population via a close encounter with Jupiter. These presumably weak bodies are subjected during their inner solar system stays to solar irradiation, collisions, and close approaches that are probably disrupting them in short timescales [2, 3]. To perform a continuous monitoring of Centaurs, and other unusual bodies is interesting because they are little-studied bodies that are probably representing a transition among the different populations [4, 5]. The recent discovery of the activity of some Centaurs (like e.g. C/NEAT 2001T4, 174P/2000 EC98, P/2004 A1 (LONEOS), and 2004 PY42) suggests that many of these bodies exhibit cometary activity [6, 7, 8]. As they are located to moderately large heliocentric distances, the detection of activity can provide interesting constrains on the sublimation mechanisms that originated such activity. During the last 6 years we have been monitoring one of the most famous Centaurs, comet 29P/Schwassmann-Wachmann 1, that exhibits unusual changes in their coma appearance and brightness [9]. Encouraged by our previous results

  12. Design and Development of an In-Space Deployable Sun Shield for the Atlas Centaur

    NASA Technical Reports Server (NTRS)

    Dew, Michael; Allwein, Kirk; Kutter, Bernard; Ware, Joanne; Lin, John; Madlangbayan, Albert; Willey, Cliff; Pitchford, Brian; O'Neil, Gary

    2008-01-01

    The Centaur, by virtue of its use of high specific-impulse (Isp) LO2/LH2 propellants, has initial mass-to-orbit launch requirements less than half of those upper stages using storable propellants. That is, for Earth escape or GSO missions the Centaur is half the launch weight of a storable propellant upper stage. A drawback to the use of Liquid oxygen and liquid hydrogen, at 90 K and 20 K respectively, over storable propellants is the necessity of efficient cryogen storage techniques that minimize boil-off from thermal radiation in space. Thermal blankets have been used successfully to shield both the Atlas Centaur and Titan Centaur. These blankets are protected from atmospheric air loads during launch by virtue of the fact that the Centaur is enclosed within the payload fairing. The smaller Atlas V vehicle, the Atlas 400, has the Centaur exposed to the atmosphere during launch, and therefore, to date has not flown with thermal blankets shielding the Centaur. A design and development effort is underway to fly a thermal shield on the Atlas V 400 vehicle that is not put in place until after the payload fairing jettisons. This can be accomplished by the use of an inflatable and deployable thermal blanket referred to as the Centaur Sun Shield (CSS). The CSS design is also scalable for use on a Delta upper stage, and the technology potentially could be used for telescope shades, re-entry shields, solar sails and propellant depots. A Phase I effort took place during 2007 in a partnership between ULA and ILC Dover which resulted in a deployable proof-of-concept Sun Shield being demonstrated at a test facility in Denver. A Phase H effort is underway during 2008 with a partnership between ULA, ILC, NASA Glenn Research Center (GRC) and NASA Kennedy Space Center (KSC) to define requirements, determine materials and fabrication techniques, and to test components in a vacuum chamber at cold temperatures. This paper describes the Sun Shield development work to date, and the

  13. Graphite/epoxy composite adapters for the Space Shuttle/Centaur vehicle

    NASA Technical Reports Server (NTRS)

    Kasper, Harold J.; Ring, Darryl S.

    1990-01-01

    The decision to launch various NASA satellite and Air Force spacecraft from the Space Shuttle created the need for a high-energy upper stage capable of being deployed from the cargo bay. Two redesigned versions of the Centaur vehicle which employed a graphite/epoxy composite material for the forward and aft adapters were selected. Since this was the first time a graphite/epoxy material was used for Centaur major structural components, the development of the adapters was a major effort. An overview of the composite adapter designs, subcomponent design evaluation test results, and composite adapter test results from a full-scale vehicle structural test is presented.

  14. [Comparison of the clinical performance of the ECLusys HBsAg II assay with the Lumipulse f and HISCL 2000-i HBsAg screening assays].

    PubMed

    Sugiura, Aya; Iwahara, Kunihiro; Suga, Yasuyuki; Uchiyama, Sachinori; Maekawa, Masato

    2012-02-01

    We compared the ECLusys HBsAgII (ECL HBsAg) assay to the Lumipulse Forte (LPf HBsAg) and HISCL (HIS HBsAg) assays. Measurement of dilution panels for which the WHO HBsAg international reference panel was the parent specimen revealed that the ECL and HIS assays enabled detection to a theoretical level of 0.04 IU/mL, whereas the LPf assay enabled detection to a level of 0.08 IU/mL. In a specificity test using high RF positive specimens (n = 33), pregnancy specimens (n = 35), cytomegalovirus antibody positive specimens (n = 36), and high M protein positive specimens (n = 21) that were confirmed negative for HBsAg by the LPf assay, negative results were obtained for all specimens on the HIS assay, but the ECL assay yielded a positive result for one of the high RF positive specimens. This individual was suggested on further testing to be an HBV carrier who was strongly positive for HBc antibody. In HBsAg mutants detection test, the detection rate was 92.3% with the ECL assay and 69.2% with the HIS assay. In a correlation test using routinely collected clinical specimens (n = 155), including positive stock specimens, aside from the one case where the LPf assay gave a negative result but both the ECL and HIS assays gave positive results, all of the results were consistent for all specimens. The above results confirmed that the ECL assay is both highly sensitive and specific, and also enables a high rate of HBsAg mutant detection.

  15. Clinical and Virological Characteristics of Chronic Hepatitis B Patients with Coexistence of HBsAg and Anti-HBs.

    PubMed

    Liu, Yong; Zhang, Le; Zhou, Jin-Yong; Pan, Jinshun; Hu, Wei; Zhou, Yi-Hua

    2016-01-01

    Coexistence of hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) comprises an atypical serological profile in patients with chronic hepatitis B virus (HBV) infection. In this study, in total 94 patients with coexisting HBsAg and anti-HBs and 94 age- and sex-matched patients with positive HBsAg were characterized by quantitatively measuring HBsAg and HBV DNA, sequencing large S genes, and observing clinical features. Compared with common hepatitis B patients, the patients with coexisting HBsAg and anti-HBs had lower HBsAg and HBV DNA levels. These two groups had similar rate of pre-S deletion mutations. However, in patients with coexisting HBsAg and anti-HBs, more amino acid substitutions in the a determinant of S gene were observed in HBV genotype C, but not in genotype B. Fourteen patients with coexisting HBsAg and anti-HBs were followed up for an average of 15.5 months. There were no significant changes in the levels of HBsAg, anti-HBs, HBV DNA and ALT over the follow-up period. Compared with the baseline sequences, amino acid substitutions in the MHR of HBsAg occurred in 14.3% (2/14) patients. In conclusion, coexistence of HBsAg and anti-HBs may be associated with higher frequency of mutations in the a determinant of HBV genotype C.

  16. Launch mission summary: INTELSAT 5(F1) ATLAS/CENTAUR-56

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The technology and capability of the INTELSAT 5 series satellites and the Atlas-Centaur launch vehicle are described. Data relative to launch windows, flight plans, radar, and telemetry are included along with selected trajectory information and a sequence of flight events.

  17. VizieR Online Data Catalog: Observations of 50 TNOs and Centaurs (Desmars+, 2015)

    NASA Astrophysics Data System (ADS)

    Desmars, J.; Camargo, J. I. B.; Braga-Ribas, F.; Vieira-Martins, R.; Assafin, M.; Vachier, F.; Colas, F.; Ortiz, J. L.; Duffard, R.; Morales, N.; Sicardy, B.; Gomes-Junior, A. R.; Benedetti-Rossi, G.

    2015-10-01

    The table provides 2895 ground-based observations of 50 trans-Neptunian objects and Centaurs performed between 2007 and 2014. The table contains the name of the observed TNO, the date of the observation, the topocentric ICRS coordinates of the object and the IAU observatory code. (1 data file).

  18. MARINER 9 SPACE PROBE ATOP ATLAS CENTAUR UNDERGOES RADIO FREQUENCY INTERFERENCE TESTS

    NASA Technical Reports Server (NTRS)

    1971-01-01

    An Atlas-Centaur rocket undergoes radio frequency interference tests at Cape Kennedy's Complex 36B prior to launch to Mars. The spacecraft was launched on a five and one-half month journey to mars, where it will enter orbit and return data about that planet's surface and atmosphere. Launch took place at 6:23 p.m. EDT, May 30, 1971.

  19. A Portrait of the Centaur 2060 Chiron: new results from groundbased and Herschel observations

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lellouch, E.; Müller, T.; Panuzzo, P.; Kiss, C.; Lim, T.; Mommert, M.; Bockelée-Morvan, D.; Vilenius, E.; Tozzi, G. P.; Mottola, S.; Duffard, R.; Barucci, M. A.

    2013-09-01

    The Herschel Open Time Key Program entitled "TNOs are Cool: A survey of the trans-Neptunian region" has been awarded 373 hours to investigate the albedo, size distribution and thermal properties of TNOs and Centaurs [1]. In this work we present the results of the combined SPIRE and PACS instruments observations over 6 bands of the Centaur 2060 Chiron, together with groundbased observations used to constrain its absolute magnitude, to investigate possible cometary activity and its surface composition. The estimated nuclear HV magnitude during the Herschel observations is 5.81±0.08, indicating a high flux from the Centaur comparable to that of its activity peak during 1989. Using this HV value, our Chiron's best size estimation, from NEATM and TPM modelling, is 218±20 km, with an albedo of 16±3 %, a value higher than previous Chiron's albedo estimation. Chiron shows the strongest decrease in the emissivity versus wavelength in the TNOs and Centaurs sample investigated with the PACS and SPIRE instruments. The results on the cometary activity analysis both in the visual and far infrared images will also be presented.

  20. Analysis of the orbit of the Centaur asteroid 2009 HW77

    NASA Astrophysics Data System (ADS)

    Wlodarczyk, I.; Cernis, K.; Eglitis, I.

    2011-12-01

    We present the time evolution of orbital elements of the Centaur asteroid 2009 HW77, discovered by KC and IE, forwards and backwards in time over a 10-Myr period. The dynamical behaviour is analysed using three software packages: the ORBFIT, the SWIFT and the MERCURY integrators. Changes in the orbital elements of 2009 HW77 clones are calculated using the classification of Horner et al. It is shown that close approaches to the giant planets significantly change the asteroid orbit. Our computations made with the SWIFT software and with the MERCURY software give similar results. The half-life is about 5 Myr in both the forward and backward integrations. Moreover, our computations suggest that the Centaur asteroid will be temporarily locked as a periodic asteroid connected with Jupiter with a Tisserand parameter smaller than 3. Hence it is dynamically similar to the Jupiter Family Comets. The mean duration in this state is about 82 kyr, but the behaviour and lifetime depend on whether capture occurs after a few hundred thousand years or a few hundred million years. Several clones of this dynamically interesting Centaur asteroid are temporarily locked up to four times as periodic asteroids connected with Jupiter, after which they are ejected from the Solar system. According to Bailey and Malhotra, asteroid 2009 HW77 may belong to the diffusing class of Centaurs, which can evolve into Jupiter Family Comets.

  1. HBsAg positivity during pregnancy and adverse maternal outcomes: a retrospective cohort analysis.

    PubMed

    Tan, J; Liu, X; Mao, X; Yu, J; Chen, M; Li, Y; Sun, X

    2016-10-01

    Hepatitis B virus infection characterized by HBsAg positivity during pregnancy is a well-recognized issue in developing countries, but the association between HBsAg positivity and adverse maternal outcomes remains uncertain. To examine the association between HBsAg positivity during pregnancy and adverse maternal outcomes, a retrospective cohort study was conducted in Sichuan province, China. Deliveries were recorded from six hospitals between 1 January 2009 and 31 December 2010. Pre-eclampsia, gestational diabetes mellitus (GDM), postpartum haemorrhage (PPH), intrahepatic cholestasis, Caesarean section and placenta previa were prespecified adverse maternal outcomes. We used two multivariate logistic regression models to assess the association between HBsAg positivity and adverse maternal outcomes. In total, 948 (4.2%) pregnant women were HBsAg positive from 22 374 deliveries. Pregnant women with positive HBsAg had higher risk of GDM (aOR1.41, 95%CI 1.15-1.74), PPH (1.44, 1.13-1.83), intrahepatic cholestasis (1.74, 1.40-2.16) and Caesarean section (1.24, 1.06-1.45). No statistical associations were found between HBsAg positivity and pre-eclampsia (1.36, 0.94-1.97), and placenta previa (1.21, 0.87-1.67). HBsAg positivity during pregnancy was associated with higher risk of multiple adverse maternal outcomes. Although the causality has yet to be established, efforts may be warranted in routine care, particularly in those with high risk for adverse maternal outcomes, given the volume population infected with HBsAg. Future studies are needed to establish causality and examine the impact of HBeAg on the adverse outcomes. PMID:27167604

  2. COMPASS Final Report: Radioisotope Electric Propulsion (REP) Centaur Orbiter New Frontiers Mission

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2011-01-01

    Radioisotope Electric Propulsion (REP) has been shown in past studies to enable missions to outer planetary bodies including the orbiting of Centaur asteroids. Key to the feasibility for REP missions are long life, low power electric propulsion (EP) devices, low mass Radioisotope Power System (RPS) and light spacecraft (S/C) components. In order to determine the key parameters for EP devices to perform these REP missions a design study was completed to design an REP S/C to orbit a Centaur in a New Frontiers (NF) cost cap. The design shows that an orbiter using several long lived (approx.200 kg xenon (Xe) throughput), low power (approx.700 W) Hall thrusters teamed with six (150 W each) Advanced Stirling Radioisotope Generators (ASRG) can deliver 60 kg of science instruments to a Centaur in 10 yr within the NF cost cap. Optimal specific impulses (Isp) for the Hall thrusters were found to be around 2000 s with thruster efficiencies over 40 percent. Not only can the REP S/C enable orbiting a Centaur (when compared to an all chemical mission only capable of flybys) but the additional power from the REP system can be used to enhance science and simplify communications. The mission design detailed in this report is a Radioisotope Power System (RPS) powered EP science orbiter to the Centaur Thereus with arrival 10 yr after launch, ending in a 1 yr science mapping mission. Along the trajectory, approximately 1.5 yr into the mission, the REP S/C does a flyby of the Trojan asteroid Tlepolemus. The total (Delta)V of the trajectory is 8.9 km/s. The REP S/C is delivered to orbit on an Atlas 551 class launch vehicle with a Star 48 B solid rocket stage

  3. [A simple ELISA method for the detection of HBsAg: Organon Teknika HBsAg Uniform II screening and confirmation test. Comparative study using the HBsAg Hapanostika method. A multicenter study].

    PubMed

    Pár, A; Mihály, I; Kömives, K

    1994-09-25

    An one-step enzyme-linked immunoabsorbent method, named as HBsAg Uniform II has been described for the detection of serum HBsAg, and a comparison was made with a widely used ELISA technique HBsAg Hepanostika test, to evaluate sensitivity, specificity and reproducibility of the method. A total of 531 serum samples from patients with liver disease and with renal failure, as well as 1065 samples from blood donors have been investigated. While the sensitivity of Uniform II vs. Hepanostika was 99.5% vs. 72.7%, the specificity was 99.2% of both methods. The positive predictive values did not differ (99.5% vs. 99.2%), however, the negative predictive values were 99.2% vs. 71.7%, respectively, in favour of Uniform II test. The Uniform II confirmatory test confirmed the positive HBsAg results in 94%, this rate was 74% using Hepanostika system. The new method proved to be a simple, quick, reliable test, which can be useful as a valuable tool in both the clinical diagnosis and blood donor screening.

  4. A new turbidometric digoxin immunoassay on the ADVIA 1650 analyzer is free from interference by spironolactone, potassium canrenoate, and their common metabolite canrenone.

    PubMed

    Datta, Pradip; Dasgupta, Amitava

    2003-08-01

    Spironolactone and potassium canrenoate (aldosterone antagonist diuretics) are often used with digoxin in clinical practice. It has been well documented in the literature that spironolactone, potassium canrenoate, and their common metabolite canrenone cross-react with the fluorescence polarization immunoassay (FPIA) for digoxin and falsely elevate measured serum digoxin concentrations. Recently a new turbidometric assay for digoxin became commercially available from Bayer Diagnostic for application on the ADVIA 1650 Chemistry analyzer. We studied the potential interference of these compounds in this new digoxin assay. Aliquots of drug-free serum were supplemented with therapeutic and above-therapeutic concentrations of spironolactone, canrenone, and potassium canrenoate, and apparent digoxin concentrations were measured. We observed apparent digoxin concentrations with the FPIA digoxin assay as expected but observed no apparent digoxin levels with the new turbidometric immunoassay. When serum pools prepared from patients receiving digoxin were supplemented with these compounds in concentrations expected in serum in patients receiving these medications, we observed falsely elevated digoxin levels with the FPIA digoxin assay, but no statistically significant change was observed with the new turbidometric assay. We conclude that the new turbidometric assay for digoxin is free from interference by spironolactone, potassium canrenoate, and their common metabolite canrenone. PMID:12883233

  5. A new turbidometric digoxin immunoassay on the ADVIA 1650 analyzer is free from interference by spironolactone, potassium canrenoate, and their common metabolite canrenone.

    PubMed

    Datta, Pradip; Dasgupta, Amitava

    2003-08-01

    Spironolactone and potassium canrenoate (aldosterone antagonist diuretics) are often used with digoxin in clinical practice. It has been well documented in the literature that spironolactone, potassium canrenoate, and their common metabolite canrenone cross-react with the fluorescence polarization immunoassay (FPIA) for digoxin and falsely elevate measured serum digoxin concentrations. Recently a new turbidometric assay for digoxin became commercially available from Bayer Diagnostic for application on the ADVIA 1650 Chemistry analyzer. We studied the potential interference of these compounds in this new digoxin assay. Aliquots of drug-free serum were supplemented with therapeutic and above-therapeutic concentrations of spironolactone, canrenone, and potassium canrenoate, and apparent digoxin concentrations were measured. We observed apparent digoxin concentrations with the FPIA digoxin assay as expected but observed no apparent digoxin levels with the new turbidometric immunoassay. When serum pools prepared from patients receiving digoxin were supplemented with these compounds in concentrations expected in serum in patients receiving these medications, we observed falsely elevated digoxin levels with the FPIA digoxin assay, but no statistically significant change was observed with the new turbidometric assay. We conclude that the new turbidometric assay for digoxin is free from interference by spironolactone, potassium canrenoate, and their common metabolite canrenone.

  6. Frequency of Detectable HBsAg in Fluid Adherent to the Endoscope, Gastric Juice, and Saliva Collected during Endoscopy in Patients Positive for HBsAg

    PubMed Central

    Yang, Ung-Suk; Liu, Bang-Hyun

    1986-01-01

    Gastric juice, saliva, and fluid adherent to the endoscope were collected from 50 patients who were seropositive for hepatitis B surface antigen (HBsAg) during the endoscopic examination of the upper gastrointestinal tract, and examined for HBsAg, using the radioimmunoassay. A positive test was obtained from 42.0% of the saliva samples, in 32.0% of the gastric juice specimens, and in 31.3% of the fluid adherent to the scope. These results should be taken as a warning, that calls for a more careful screening of the patients and disinfection of the endoscope. PMID:3154614

  7. HBsAg Positive Patient Characteristics in Hospital and Blood Donation Camps

    PubMed Central

    Varghese, Joy; Joseph, Jensingh; Srinivasan, Vijaya; Jayanthi, Venkataraman; Rela, Mohamed

    2013-01-01

    Background. Prevention of the residual risk of transfusion transmitted hepatitis B virus infection (HBV) is mostly dependant on serological screening of blood donors for HBsAg and antibody to hepatitis B core antigen (anti-HBc Ab). This study aimed to study the prevalence of HBsAg and anti-HBc Ab and to compare the profile of blood donors attending a blood donation camp and people attending a hospital based camp. Methods. In the blood donor camp, all the blood units were screened for HBV, (HBsAg and anti-HBc), and in the hospital based camp, screening was done for HBsAg alone. Baseline demographic characteristics were noted. Results. The number of blood bank donors was 363 (47.5%) and hospital camp attendees was 402 (52.5%). Prevalence of HBsAg positivity was similar in both the groups at 1.7% and 1.9%, respectively. Anti-HBc Ab positivity (Total) was 6% among the blood donors; Overall prevalence of HBV infection in this group was 3.2%. Conclusion. Policy for checking the collected blood unit by 3 tests for anti-HBc, anti-HBsAb, and HBsAg should be reconsidered to possibly achieve the zero risk goal of transfusion transmitted HBV infection. Blood obtained from a vaccinated donor may give an added protection to the recipient. PMID:24083029

  8. CENTAURS AND SCATTERED DISK OBJECTS IN THE THERMAL INFRARED: ANALYSIS OF WISE/NEOWISE OBSERVATIONS

    SciTech Connect

    Bauer, James M.; Grav, Tommy; Blauvelt, Erin; Collaboration: WISE Team; PTF Team; and others

    2013-08-10

    The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and scattered disk objects (SDOs) in the thermal infrared, including 15 new discoveries. We present analyses of these observations to estimate sizes and mean optical albedos. We find mean albedos of 0.08 {+-} 0.04 for the entire data set. Thermal fits yield average beaming parameters of 0.9 {+-} 0.2 that are similar for both SDO and Centaur sub-classes. Biased cumulative size distributions yield size-frequency distribution power law indices of {approx}-1.7 {+-} 0.3. The data also reveal a relation between albedo and color at the 3{sigma} level. No significant relation between diameter and albedos is found.

  9. CCD photometry of active Centaur 166P/2001 T4 (NEAT)

    NASA Astrophysics Data System (ADS)

    Shi, J. C.; Ma, Y. H.

    2015-12-01

    To study the secular evolution of the activity of Centaur 166P/2001 T4 (Near Earth Asteroid Tracking, NEAT) and its physical properties, we present the results of optical observations of the Centaur taken on 2009 March 29 with the Keck 10-m telescope located atop Mauna Kea, Hawaii. It was still active at rh = 11.9 au post-perihelion. An upper limit of the nucleus radius of aN < 14.32 km is derived. The colour index is B - R = 1.59 ± 0.05. The Afρ value is measured to be 288 ± 19 cm and the corresponding dust production rate is 252 kg s-1. Finally, a possible mechanism of activity is discussed.

  10. Solar Panel Integration as an Alternate Power Source on Centaur 2 (SPIAPS)

    NASA Technical Reports Server (NTRS)

    Gebara, Christine A.; Schuetze, Nich A.; Knochel, Aviana M.; Magruder, Darby F.

    2011-01-01

    The dream of exploration has inspired thousands throughout time. Space exploration, in particular, has taken the past century by storm and caused a great advance in technology. In this project, a retractable solar panel array will be developed for use on the Centaur 2 Rover. Energy generated by the solar panels will go to power the Centaur 2 Robot (C2) or Regolith & Environment Science & Oxygen & Lunar Volatile Extraction (RESOLVE) payload, an in-situ resource utilization project. Such payload is designed to drill into lunar and Martian terrain as well as be able to conduct other geological testing; RESOLVE is slated for testing in 2012. Ultimately, this project will fit into NASA s larger goal of deep space exploration as well as long term presence outside Earth s orbit.

  11. Dynamical studies of Centaurs and their sources: interactions with the Main Belt

    NASA Astrophysics Data System (ADS)

    Galiazzo, Mattia; Carruba, Valerio; Wiegert, Paul

    2015-08-01

    Centaurs are objects whose orbits are found between those of the giant planets. Their main source is presumed to be the Trans-Neptunian objects (TNOs), and they are among the sources of Near-Earth Objects. Their dynamical evolution is heavily influenced by close encounters with giant planets and some of them were most likely scattered into their current orbits. After experiencing close encounters with the giant planets, Centaurs may have their eccentricity increased to values large enough to reach the main belt (a<3.8 au) and even the region of the Near-Earth asteroids, with a perihelion, (q<1.3 au). Some may become short-period comets and a fraction falls into the Sun or become sun-grazers. In this work we propose to investigate the interactions of dynamically evolving Centaurs and other members of the outer Solar System (i.e. Plutinos and Trans-Neptunian objects which cross the orbit of Neptune) with main belt asteroids to determine if chaotic scattering caused by close encounters and impacts may have played (and/or still play) a role in the dynamical evolution of the main belt. Preliminary results show already that TNOs (larger than 100 km size) are capable of reaching the inner solar system and may cross the main belt several times during an interval of time at least of ~10 kyrs. Centaurs such as 1995 S1 can generate significant deflections to the orbits of main belt asteroids after close encounters. In particular, we plan to investigate if close encounters with large (diameters larger than 100 km) outer Solar System bodies could have been responsible for the scattering of V-type asteroids from the Vesta family beyond the 3J:1 mean motion resonance, into the central and outer main belt.

  12. The Period of Rotation, Shape, Density, and Homogeneous Surface Color of the Centaur 5145 Pholus

    NASA Astrophysics Data System (ADS)

    Rall, James; Romanishin, W.; Consolmagno, G. J.; Worhatch, R.; Nelson, M.; Weidenschilling, S.

    2005-04-01

    We present optical photometry of the Centaur 5145 Pholus during 05/2003 and 04/2004 using the facility CCD camera on the 1.8-m VATT on Mt. Graham, Arizona. We derive a double-peaked lightcurve and a rotation period of 9.980 hr with amplitude of 0.60 magnitude. We derive four possible rotational pole positions as well as axial ratios of a/b=1.9 and c/b=0.9. If we assume Pholus is a strengthless rubble-pile and its non-spherical shape is due to rotational distortion, our axial ratios and period measurements indicate Pholus has a density of 0.5 g per cubic centimeter, suggestive of an ice-rich, porous interior. By combining B-band and R-band lightcurves, we find B-R=1.94 and any B-R color variation over the surface of Pholus must be smaller than 0.06 magnitudes. By combining our V-R measurements with values in the literature, we find no evidence for any color variegation between the northern and southern hemispheres of Pholus. Our observations add to the evidence that individual Centaurs and KBOs exhibit homogeneous surface colors and hence gray impact craters on radiation reddened crusts are probably not responsible for the colors seen among the Centaur and Kuiper belt object populations.

  13. The observation of large semi-major axis Centaurs: Testing for the signature of a planetary-mass solar companion

    NASA Astrophysics Data System (ADS)

    Gomes, Rodney S.; Soares, Jean S.; Brasser, Ramon

    2015-09-01

    Several objects whose perihelion lies between Jupiter and Neptune have large semi-major axes a > 100 au, two of them having semi-major axis above 1000 au. Since these objects' perihelia share the same region as the classical Centaurs, a coherent nomenclature for them could be large semi-major axis Centaurs (Laces). It has been argued that the classical Centaurs, with semi-major axes below 50 au, originate from the Scattered Disk. However, the Laces most likely originate from the Oort Cloud. We determine the brightest object in the Laces, classical Centaurs (with semi-major axis >20 au) and Scattered Disk populations using a procedure that introduces observational bias to a set of objects in orbits obtained from numerical simulations of the evolution of the Oort cloud and Scattered Disk in the framework of the Nice model. The application of the procedure consistently determines that the brightest distant Lace (semi-major axis above 500 au) is fainter than the brightest classical Centaur by about one magnitude, no matter what parameters were used for the procedure. However, reality shows a reversed situation: there is an excess of Laces with lower visual magnitudes. It is not clear why this is the case. We test whether a planetary-mass solar companion could produce an excess of bright Laces in comparison with classical Centaurs. We find that with the companion there is an excess of luminous Laces compared to when there is no companion. However, the companion model also produces many classical Centaurs with lower visual magnitudes than the observed ones. Thus we conclude that the companion does not solve this visual magnitude inconsistency, although the results are in general more coherent under the model with the companion than without.

  14. Determination of HBsAg subtypes in Western Siberian part of Russia.

    PubMed

    Netesova, I G; Swenson, P D; Osipova, L P; Gubina, M A; Posukh, O L; Netesov, S V

    2003-10-01

    A set of monoclonal antibodies with specificity for hepatitis B surface antigen (HBsAg) was used for subtyping this antigen in sera from indigenous natives, blood donors, and drug users in Western Siberia with a modified commercial enzyme immunoassay kit for HBsAg detection. Three subtypes of HBsAg in a ratio of 36 (78%) ayw2:8 ayw3varB (18%):2 (4%) adw2 were found in 46 (100%) HBsAg-positive sera of different aboriginal populations of Western Siberia: the Tundra Nenets, Northern Khanty, Southern Altaians, and Kazakhs. Four subtypes of HBsAg in a ratio of 81 (57%) ayw2:58 (15 ayw3varA and 43 ayw3varB; 44%):2 (1%) adw2 were detected in 141 (100%) samples of blood donors from ten cities of Western Siberia. Three subtypes of HBsAg in a ratio of 34 ayw3:(both variants, 33 ayw3varA and 1 ayw3varB; 97.1%):1 (2.9%) ayw2 were found in blood of 35 injection drug users in Novosibirsk.

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

    SciTech Connect

    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 /sup 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.

  16. Carbonization in Titan Tholins: implication for low albedo on surfaces of Centaurs and trans-Neptunian objects

    NASA Astrophysics Data System (ADS)

    Giri, Chaitanya; McKay, Christopher P.; Goesmann, Fred; Schäfer, Nadine; Li, Xiang; Steininger, Harald; Brinckerhoff, William B.; Gautier, Thomas; Reitner, Joachim; Meierhenrich, Uwe J.

    2016-07-01

    Astronomical observations of Centaurs and trans-Neptunian objects (TNOs) yield two characteristic features - near-infrared (NIR) reflectance and low geometric albedo. The first feature apparently originates due to complex organic material on their surfaces, but the origin of the material contributing to low albedo is not well understood. Titan tholins synthesized to simulate aerosols in the atmosphere of Saturn's moon Titan have also been used for simulating the NIR reflectances of several Centaurs and TNOs. Here, we report novel detections of large polycyclic aromatic hydrocarbons, nanoscopic soot aggregates and cauliflower-like graphite within Titan tholins. We put forth a proof of concept stating the surfaces of Centaurs and TNOs may perhaps comprise of highly `carbonized' complex organic material, analogous to the tholins we investigated. Such material would apparently be capable of contributing to the NIR reflectances and to the low geometric albedos simultaneously.

  17. Orbit determination of trans-Neptunian objects and Centaurs for the prediction of stellar occultations

    NASA Astrophysics Data System (ADS)

    Desmars, J.; Camargo, J. I. B.; Braga-Ribas, F.; Vieira-Martins, R.; Assafin, M.; Vachier, F.; Colas, F.; Ortiz, J. L.; Duffard, R.; Morales, N.; Sicardy, B.; Gomes-Júnior, A. R.; Benedetti-Rossi, G.

    2015-12-01

    Context. The prediction of stellar occultations by trans-Neptunian objects (TNOs) and Centaurs is a difficult challenge that requires accuracy both in the occulted star position and in the object ephemeris. Until now, the most used method of prediction, involving dozens of TNOs/Centaurs, has been to consider a constant offset for the right ascension and for the declination with respect to a reference ephemeris, usually the latest public version. This offset is determined as the difference between the most recent observations of the TNO/Centaur and the reference ephemeris. This method can be successfully applied when the offset remains constant with time, i.e. when the orbit is stable enough. In this case, the prediction even holds for occultations that occur several days after the last observations. Aims: This paper presents an alternative method of prediction, based on a new accurate orbit determination procedure, which uses all the available positions of the TNO from the Minor Planet Center database, as well as sets of new astrometric positions from unpublished observations. Methods: Orbits were determined through a numerical integration procedure called NIMA, in which we developed a specific weighting scheme that considers the individual precision of the observation, the number of observations performed during one night by the same observatory, and the presence of systematic errors in the positions. Results: The NIMA method was applied to 51 selected TNOs and Centaurs. For this purpose, we performed about 2900 new observations in several observatories (European South Observatory, Observatório Pico dos Dias, Pic du Midi, etc.) during the 2007-2014 period. Using NIMA, we succeed in predicting the stellar occultations of 10 TNOs and 3 Centaurs between July 2013 and February 2015. By comparing the NIMA and Jet Propulsion Laboratory (JPL) ephemerides, we highlight the variation in the offset between them with time, by showing that, generally, the constant offset

  18. Titan/Centaur D1TTC-3 Viking B flight data report

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Titan/Centaur TC-3 was launched from the Eastern Test Range, Complex 41, at 02:34 PM EDT on Tuesday, September 9, 1975. This was the third operational flight of the newest NASA unmanned launch vehicle. The spacecraft was the Viking B, the second of two orbiting and landing missions to Mars planned for the 1975 Martian launch opportunity. The objective of the launch phase of the mission, to inject the Viking spacecraft onto the planned transfer orbit to Mars, was successfully accomplished. A review of the launch vehicle system flight data is presented.

  19. First ultraviolet reflectance measurements of several Kuiper Belt objects, Kuiper Belt object satellites, and new ultraviolet measurements of A Centaur

    SciTech Connect

    Stern, S. A.; Schindhelm, E.; Cunningham, N. J.

    2014-05-01

    We observed the 2600-3200 Å (hereafter, mid-UV) reflectance of two Kuiper Belt Objects (KBOs), two KBO satellites, and a Centaur, using the Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS). Other than measurements of the Pluto system, these constitute the first UV measurements obtained of KBOs, and KBO satellites, and new HST UV measurements of the Centaur 2060 Chiron. We find significant differences among these objects, constrain the sizes and densities of Haumea's satellites, and report the detection of a possible spectral absorption band in Haumea's spectrum near 3050 Å. Comparisons of these objects to previously published UV reflectance measurements of Pluto and Charon are also made here.

  20. Centaur in-tank explosion flow fields within STS and Titan 4 payload spaces

    NASA Technical Reports Server (NTRS)

    Eck, M.; Mukunda, M.

    1988-01-01

    Explosions are examined which result from the mixing of liquid hydrogen and liquid oxygen (LH2-LO2) such that the reactants are confined by the missile (CBM) body. Explosion which were confined by the ground surface (CBGS) were also studied, with results reported elsewhere. Initial attempts to predict the reported PYRO experimental results were unsuccessful. A new reaction energy addition hypothesis was then developed and tested. The results obtained provide reasonable agreement with the experiments both in the near and far field. Calculations were performed to predict the environment which would occur at the Galileo Radioisotope Thermoelectric Generator (RTG) location given a Centaur G' upper stage and an STS launch vehicle. It was concluded that the principle threat to the RTG in this environment would be the impact of a slug of LH2. No analyses were conducted to assess the response of the Galileo RTG to such an environment. It was shown that the flow field resulting from the failure of the Centaur G' tankage was benign. It was concluded that while the cryogen particle velocity was very high, the flow field density was extremely low. As a result, the dynamic pressure was a trivial eight psia.

  1. Extra-red transneptunian objects and Centaurs: Composition and chemical history

    NASA Astrophysics Data System (ADS)

    Dalle Ore, C. M.; Barucci, M. A.; Cruikshank, D. P.; Emery, J. P.

    2014-07-01

    We present the results of a systematic analysis of the surface composition of ten of the reddest transneptunian objects (TNOs). The goal of the analysis is to determine the current chemical compositions of these extra-red objects and investigate possible paths of chemical evolution since formation. The sample consists of six objects from the classical and resonant populations, one detached object, and three Centaurs. The classical and resonant objects are expected to be similar to each other in composition, while the surfaces of the three Centaurs could have been significantly modified as their orbits evolved. Furthermore, Brown et al. (Brown, M.E., Schaller, E.L., & Fraser, W.C., 2011. A Hypothesis for the Color Diversity of the Kuiper Belt. ApJL, 739, L60) propose that objects with red color are rich in methanol. The available data consist of broad-band photometric measurements in the wavelength range between 0.3 and 4.5 μ m. The photometric measurements are scaled to the albedo at 0.55 μ m to yield an approximation of the spectral shape of each object that is then compared to a library of synthetic spectra of mixtures of materials known to be present on the surfaces of TNOs. Errors as well as phase-angle differences are taken into account as part of the fitting uncertainty. For each object, we obtain a range of compositions that match their spectral distribution within the estimated errors. This yields the likelihood for the various materials to be present on the surface as well as a rough measure of the uncertainty of the estimate. All objects show presence of methanol and/or methane on their surface, supporting the Brown et al. (2011) hypothesis. To further analyze our results, ices are grouped into 'stable' (H_2O), 'partially stable' (CH_3OH, CO_2), and 'volatile' (CH_4, CO, N_2). Our results show some difference in the amount of 'volatile' and 'partially stable' ices among the classical and resonant objects. A trend in the sense of less ice present on

  2. "TNOs are Cool": A survey of the trans-Neptunian region. XI. A Herschel-PACS view of 16 Centaurs

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Pinilla-Alonso, N.; Santos-Sanz, P.; Vilenius, E.; Ortiz, J. L.; Mueller, T.; Fornasier, S.; Lellouch, E.; Mommert, M.; Pal, A.; Kiss, C.; Mueller, M.; Stansberry, J.; Delsanti, A.; Peixinho, N.; Trilling, D.

    2014-04-01

    Context. Centaurs are the transitional population between trans-Neptunian objects (TNOs) and Jupiter-family comets. Their physical properties provide an insight into TNO properties, but only under restricted conditions since Centaurs are closer to the Sun and Earth. For this reason it is possible to access the smaller ones, which is more difficult to do with the TNO population. Aims: The goal of this work is to characterize a set of 16 Centaurs in terms of their size, albedo, and thermal properties. We study the correlations, for a more extended sample obtained from the literature, of diameter, albedo, orbital parameters, and spectral slopes. Methods: We performed three-band photometric observations using Herschel-PACS and used a consistent method for the data reduction and aperture photometry of this sample to obtain monochromatic flux densities at 70, 100, and 160 μm. Additionally, we used Spitzer-MIPS flux densities at 24 and 70 μm when available. We also included in our Centaur sample scattered disk objects, a dynamical family of TNOs, using results previously published by our team, and some Centaurs observed only with the Spitzer-MIPS instrument. Results: We have determined new radiometric sizes and albedos of 16 Centaurs. The first conclusion is that the albedos of Centaur objects are not correlated with their orbital parameters. Similarly, there is no correlation between diameter and orbital parameters. Most of the objects in our sample are dark (pv< 7%) and most of them are small (D< 120 km). However, there is no correlation between albedo and diameter, in particular for the group of small objects as albedo values are homogeneously distributed between 4 to 16%. The correlation with the color of the objects showed that red objects are all small (mean diameter 65 km), while the gray ones span a wide range of sizes (mean diameter 120 km). Moreover, the gray objects tend to be darker, with a mean albedo of 5.6%, compared with a mean of 8.5% (ranging from 5 to

  3. Three Orbital Burns to Molniya Orbit Via Shuttle_Centaur G Upper Stage

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.

    2015-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982 to 1986 joint National Aeronautics and Space Administration (NASA)-United States Air Force (USAF) Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37 deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57 deg inclined orbit: 9,545 versus 9,552 lb of separated spacecraft weight, respectively. There was a significant reduction in the need for propellant launch time reserve for a 1 hr window: only 78 lb for the three burn transfer versus 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three versus two burn transfer (12 vs. 1-1/4 hr), but could be

  4. Three Orbital Burns to Molniya Orbit via Shuttle Centaur G Upper Stage

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.

    2014-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982-86 joint NASA-USAF Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57deg inclined orbit: 9,545 lb vs. 9,552 lb of separated spacecraft weight respectively. There was a significant reduction in the need for propellant launch time reserve for a one hour window: only 78 lb for the three burn transfer vs. 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three vs. two burn transfer (12 vs. 11/4 hrs), but could be accommodated by modest modifications to Centaur systems. Future applications were

  5. Carbon monoxide in the distantly active centaur 174P/Echeclus

    NASA Astrophysics Data System (ADS)

    Wierzchos, Kacper; Womack, Maria

    2016-10-01

    60558 Echeclus is very unusual. It has a dual asteroid-comet designation, and is classified as a centaur. A dust-rich outburst was observed when it was at a heliocentric distance, r, of 13.1 AU pre-perihelion (Choi & Weissman 2006). Interestingly, the coma's center of brightness was not at the nucleus location, but was offset by up to 7 arcseconds (Weissman et al. 2006, Tegler et al. 2006). This was hypothesized to be a due to a fragment that split off the nucleus and began outgassing on its own (Fernandez 2009). A smaller coma was observed when Echeclus was at r = 8.5 AU, but overall, the object appears dormant with little or no extended coma observed at optical wavelengths for years at a time (Choi et al. 2015, Rousselot et al. 2015). Echeclus is too far from the Sun for any of the activity to be caused by water-ice sublimation, the dominant cause for most comets. Instead, the coma must have been generated by another mechanism, such as impact or supervolatile outgassing. If a substantial amount of the supervolatile CO were relatively near the surface and outgassing, then its emission could be detected, or significant limits could be set, through radio observations when Echeclus was near perihelion, which occurred at 2015 Apr at r = 5.8 AU. In order to better explore the volatile nature of this centaur, we searched for CO emission from the J=2-1 rotational line at 230 GHz with the Arizona Radio Observatory (ARO) 10-m Sub-millimeter Telescope (SMT) during May and June 2016 when the comet was at r = 6.1 AU, post-perihelion. We find that the CO production rate from Echeclus is substantially lower than what is typically observed for 29P/Schwassmann Wachmann 1, another distantly active comet often classified as a centaur. We report on the measurements and implications.The SMT is operated by the ARO, the Steward Observatory, and the University of Arizona, with support through the NSF University Radio Observatories program (AST-1140030).

  6. Pan-STARRS 1 observations of the unusual active Centaur P/2011 S1(Gibbs)

    SciTech Connect

    Lin, H. W.; Ip, W. H.; Chen, W. P.; Chen, Y. T.; Lacerda, P.; Holman, M.; Protopapas, P.; Burgett, W. S.; Chambers, K. C.; Flewelling, H.; Huber, M. E.; Jedicke, R.; Kaiser, N.; Magnier, E. A.; Metcalfe, N.; Price, P. A.

    2014-05-01

    P/2011 S1 (Gibbs) is an outer solar system comet or active Centaur with a similar orbit to that of the famous 29P/Schwassmann-Wachmann 1. P/2011 S1 (Gibbs) has been observed by the Pan-STARRS 1 (PS1) sky survey from 2010 to 2012. The resulting data allow us to perform multi-color studies of the nucleus and coma of the comet. Analysis of PS1 images reveals that P/2011 S1 (Gibbs) has a small nucleus <4 km radius, with colors g {sub P1} – r {sub P1} = 0.5 ± 0.02, r {sub P1} – i {sub P1} = 0.12 ± 0.02, and i {sub P1} – z {sub P1} = 0.46 ± 0.03. The comet remained active from 2010 to 2012, with a model-dependent mass-loss rate of ∼100 kg s{sup –1}. The mass-loss rate per unit surface area of P/2011 S1 (Gibbs) is as high as that of 29P/Schwassmann-Wachmann 1, making it one of the most active Centaurs. The mass-loss rate also varies with time from ∼40 kg s{sup –1} to 150 kg s{sup –1}. Due to its rather circular orbit, we propose that P/2011 S1 (Gibbs) has 29P/Schwassmann-Wachmann 1-like outbursts that control the outgassing rate. The results indicate that it may have a similar surface composition to that of 29P/Schwassmann-Wachmann 1. Our numerical simulations show that the future orbital evolution of P/2011 S1 (Gibbs) is more similar to that of the main population of Centaurs than to that of 29P/Schwassmann-Wachmann 1. The results also demonstrate that P/2011 S1 (Gibbs) is dynamically unstable and can only remain near its current orbit for roughly a thousand years.

  7. Stabilization and immune response of HBsAg encapsulated within poly(lactic-co-glycolic acid) microspheres using HSA as a stabilizer.

    PubMed

    Xu, Wenjuan; He, Jintian; Wu, Guanghao; Xiong, Fangfang; Du, Huijuan; Wang, Gaizhen

    2015-12-30

    The aim of this study was to prepare poly(lactic-co-glycolic acid) (PLGA) microspheres containing hepatitis B virus surface antigen (HBsAg) using human serum albumin (HSA) as a stabilizer. Lyophilization and emulsification of HBsAg solution with dichloromethane caused a considerable loss of HBsAg antigenicity. Thus, the effects of HSA and trehalose on HBsAg recovery during lyophilization and emulsification were investigated. Adding HSA to HBsAg solutions significantly improved antigen recovery to >90% during lyophilization and emulsification. The effects of co-encapsulated HSA on the characteristics of the PLGA microspheres and stability of HBsAg released from the microspheres were also investigated. The in vitro release test showed that HBsAg was released from the PLGA microspheres continuously over seventy days. A large amount of released HBsAg was inactive without co-encapsulation of HSA. On the contrary, with HSA co-encapsulation, the released HBsAg retained approximately 90% of its antigenicity. The single injection of the HBsAg-HSA-loaded PLGA microspheres in rats resulted in higher anti-HBsAg IgG and Th1 cytokine levels than the single injection of the HBsAg-loaded microspheres or two injections of the conventional aluminum-adjuvanted HBsAg vaccine. Based on these findings, the HBsAg-HSA-loaded PLGA microspheres could be an effective carrier for HBsAg and form a promising depot system.

  8. Geographical variation in prevalence of hepatitis B virus DNA in HBsAg negative patients.

    PubMed

    Lo, Y M; Lo, E S; Mehal, W Z; Sampietro, M; Fiorelli, G; Ronchi, G; Tse, C H; Fleming, K A

    1993-04-01

    AIMS--To study the geographical variation of the prevalence of hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg) negative subjects. METHODS--A nested polymerase chain reaction (PCR) assay was used to amplify the core region of HBV. The assay was able to detect 10 molecules of a full length HBV plasmid. RESULTS--When applied to HBsAg negative paraffin wax embedded liver samples from Italy, Hong Kong, and the United Kingdom, a geographical variation in the prevalence of HBV-DNA positivity was noted. Two of 18 (11%) of Italian samples and 2/29 (6.9%) of Hong Kong samples were positive for HBV-DNA while none of the 70 cases from the United Kingdom was positive by nested PCR. Contamination by plasmid DNA was excluded using a novel method based on heteroduplex formation. One HBV-DNA positive case had idiopathic chronic active hepatitis, but the diagnoses in the other three HBV-DNA positive cases did not suggest any aetiological connection between HBV-DNA positivity and liver pathology. CONCLUSIONS--HBV-DNA could be detected in the liver tissues of a proportion of HBsAg negative subjects. The prevalence of such cases is related to the endemic rate of a geographical region. The use of HBV PCR on paraffin wax embedded tissues will be valuable for future studies on the molecular epidemiology of HBV.

  9. Geographical variation in prevalence of hepatitis B virus DNA in HBsAg negative patients.

    PubMed

    Lo, Y M; Lo, E S; Mehal, W Z; Sampietro, M; Fiorelli, G; Ronchi, G; Tse, C H; Fleming, K A

    1993-04-01

    AIMS--To study the geographical variation of the prevalence of hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg) negative subjects. METHODS--A nested polymerase chain reaction (PCR) assay was used to amplify the core region of HBV. The assay was able to detect 10 molecules of a full length HBV plasmid. RESULTS--When applied to HBsAg negative paraffin wax embedded liver samples from Italy, Hong Kong, and the United Kingdom, a geographical variation in the prevalence of HBV-DNA positivity was noted. Two of 18 (11%) of Italian samples and 2/29 (6.9%) of Hong Kong samples were positive for HBV-DNA while none of the 70 cases from the United Kingdom was positive by nested PCR. Contamination by plasmid DNA was excluded using a novel method based on heteroduplex formation. One HBV-DNA positive case had idiopathic chronic active hepatitis, but the diagnoses in the other three HBV-DNA positive cases did not suggest any aetiological connection between HBV-DNA positivity and liver pathology. CONCLUSIONS--HBV-DNA could be detected in the liver tissues of a proportion of HBsAg negative subjects. The prevalence of such cases is related to the endemic rate of a geographical region. The use of HBV PCR on paraffin wax embedded tissues will be valuable for future studies on the molecular epidemiology of HBV. PMID:8496385

  10. Geographical variation in prevalence of hepatitis B virus DNA in HBsAg negative patients.

    PubMed Central

    Lo, Y M; Lo, E S; Mehal, W Z; Sampietro, M; Fiorelli, G; Ronchi, G; Tse, C H; Fleming, K A

    1993-01-01

    AIMS--To study the geographical variation of the prevalence of hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg) negative subjects. METHODS--A nested polymerase chain reaction (PCR) assay was used to amplify the core region of HBV. The assay was able to detect 10 molecules of a full length HBV plasmid. RESULTS--When applied to HBsAg negative paraffin wax embedded liver samples from Italy, Hong Kong, and the United Kingdom, a geographical variation in the prevalence of HBV-DNA positivity was noted. Two of 18 (11%) of Italian samples and 2/29 (6.9%) of Hong Kong samples were positive for HBV-DNA while none of the 70 cases from the United Kingdom was positive by nested PCR. Contamination by plasmid DNA was excluded using a novel method based on heteroduplex formation. One HBV-DNA positive case had idiopathic chronic active hepatitis, but the diagnoses in the other three HBV-DNA positive cases did not suggest any aetiological connection between HBV-DNA positivity and liver pathology. CONCLUSIONS--HBV-DNA could be detected in the liver tissues of a proportion of HBsAg negative subjects. The prevalence of such cases is related to the endemic rate of a geographical region. The use of HBV PCR on paraffin wax embedded tissues will be valuable for future studies on the molecular epidemiology of HBV. Images PMID:8496385

  11. HBsAg detection by passive hemagglutination (Hepanosticon--Organon). Advantages and disadvantages in comparison with other methods.

    PubMed

    Balş, M G; Hagiescu, L

    1976-01-01

    Investigated comparatively with immunodiffusion, electroimmunodiffusion, complement fixation and Latex agglutination, passive hemagglutination with the Hepanosticon--Organon reagent proved to be an easy, rapid, highly reproducible method for HBsAg detection.

  12. Computer simulation of temperatures on the Centaur standard shroud during heated jettison tests

    NASA Technical Reports Server (NTRS)

    Hemminger, J. A.

    1973-01-01

    A heating fixture for simulating the heating and environment encountered by the Centaur standard shroud (CSS) during its ascent through the earth's atmosphere is discussed. A computer program was developed to provide a means of determining the overall temperature profile of a free-skin model of the CSS during the heating portion of the heated jettison tests. The program treats the energy contribution of each lamp on the heater to various points on the CSS surface. The analytic model was verified by adapting the computer program to the configuration of the hardware used in a series of Intermediate Scale Tests performed on a 2.4 meters by 2.4 meters section of the CSS corrugated structure. A comparison of some predicted versus experimental results from these tests is presented.

  13. Low gravity reorientation in a scale-model Centaur liquid-hydrogen tank

    NASA Technical Reports Server (NTRS)

    Salzman, J. A.; Masica, W. J.; Lacovic, R. F.

    1973-01-01

    An experiment was conducted to investigate the process of liquid reorientation from one end of a scale-model Centaur liquid-hydrogen tank to the other end by means of low-level accelerations. Prior to reorientation, the liquid was stabilized at the top of the tank at a Bond number of 15. Tanks both with and without ring baffles and with tank radii of 5.5 and 7.0 centimeters were used in the study. Reorientation acceleration values were varied to obtain Bond numbers of 200 and 450. Liquid fill levels of 20 and 70 percent were used. From the data in this study, relations were developed to estimate reorientation event times in unbaffled tanks through the point of final liquid clearing from the top of the tank. The insertion of ring baffles drastically changed the reorientation flow profiles but resulted in only minor differences in the times of tank-top uncovering and liquid collection.

  14. A 20k Payload Launch Vehicle Fast Track Development Concept Using an RD-180 Engine and a Centaur Upper Stage

    NASA Technical Reports Server (NTRS)

    Toelle, Ronald (Compiler)

    1995-01-01

    A launch vehicle concept to deliver 20,000 lb of payload to a 100-nmi orbit has been defined. A new liquid oxygen/kerosene booster powered by an RD-180 engine was designed while using a slightly modified Centaur upper stage. The design, development, and test program met the imposed 40-mo schedule by elimination of major structural testing by increased factors of safety and concurrent engineering concepts. A growth path to attain 65,000 lb of payload is developed.

  15. Physical properties of transneptunian objects, Centaurs, and Trojans from thermal observations

    NASA Astrophysics Data System (ADS)

    Mueller, M.

    2014-07-01

    The most productive way to measure the size and albedo of small bodies throughout the Solar System is through studies of their thermal emission. This is complicated for the cold bodies in the outer Solar System, whose thermal emission peaks at wavelengths for which the Earth's atmosphere is opaque. While the relatively warm Trojans are marginally accessible from the ground in the Q band, the sizes of only a handful of transneptunian objects (TNOs) and Centaurs were known before Spitzer was launched in 2003. Spitzer/MIPS photometry at wavelengths of 24 and 70 microns allowed size and albedo of tens of TNOs and Centaurs to be measured. Herschel (operational in 2009--2013) allowed photometry of a total of ˜140 TNOs at wavelengths between 70 and 500 microns using PACS and SPIRE, chiefly in the framework of the Key Programme ``TNOs are Cool!''. I will present selected results from these surveys and discuss their implications on our knowledge of the origin and evolution of the Solar System, as evidenced by its coldest members. Of particular interest are the sizes of binary systems. Where their masses are known from spatially resolved observations, diameter measurements allow the bulk mass density to be determined, providing a unique probe of the object's interior. In the past few years, we have witnessed a remarkable increase in the number of successfully observed stellar occultations by TNOs and other small bodies. They provide an elegant, model-independent, and accurate way of measuring projected TNO dimensions at the time of the event and at the location of the observer(s). Even satellites or ring systems can be detected this way. However, predictable occultations are rare events and will likely stay infrequent, even in the post-Gaia era. Studies of the ensemble properties of the transneptunian populations will continue to rely on thermal observations. Reliable thermal modeling requires some knowledge of the target's temperature. Optimally, this is obtained through

  16. Analysis of infrared spectra of a stellar occultation by the active Centaur (2060) Chiron

    NASA Astrophysics Data System (ADS)

    Gulbis, A.; Emery, J.; Ruprecht, J.; Bosh, A.; Person, M.; Bianco, F.; Bus, S.; Zangari, A.

    2014-07-01

    Chiron, the first known Centaur, orbits primarily between Saturn and Uranus. It was originally thought to be an asteroid, but has since exhibited cometary-like behavior [e.g., 1,2]. This behavior is unusual given Chiron's relatively large distance from the Sun and its nucleus being larger than that of other comets. Previous stellar occultation data suggested that Chiron is greater than approximately 180 km in diameter and detected narrow jets as well as a gravitationally-bound dust coma [3,4]. More recent measurements from Herschel place the size at 218 ± 20 km [5]. On 29 November 2011, Chiron occulted a fairly bright star (R=14.8) as seen from Hawai'i. We observed the event from the 3-m NASA Infrared Telescope Facility (IRTF) on Mauna Kea and the 2-m Faulkes Telescope North at Haleakala (run by the Las Cumbres Observatory Global Telescope network, LCOGT). Data were taken as visible wavelength images at the Faulkes, using an Andor iXon 888 camera, and at the IRTF, using the MIT Optical Rapid Imaging System (MORIS [6]). Simultaneously, low-resolution, near-infrared, 0.9--2.4 micron spectra were taken using SpeX [7] on the IRTF. The MORIS lightcurve contains an occultation by Chiron's nucleus, with a chord corresponding to a minimum radius of 158 ± 14 km [8,9]. The Faulkes lightcurve, a station located 97 km to the north, contains deep, symmetric dips before and after the predicted midtime and no solid-body occultation. The extinction features are located roughly 300 km from Chiron's center, and are approximately 3 and 7 km in extent separated by 10--14 km [8,9]. The MORIS data were taken at ten times slower cadence (2 s) and show shallow dips at roughly the same distance from Chiron's center. These lightcurve features indicate optically thick material in a roughly circular distribution, suggesting the presence of a near-circular ring or shell of material. Here, we present an analysis of the IRTF SpeX data of the occultation. Although the cadence was relatively

  17. [Asymptomatic carriers of HBsAg: is a follow-up necessary?].

    PubMed

    Vignote, M L; Gómez-Camacho, F; Poyato, A; González, R; Palomo, D; Hervás, A; Peña, J; Miño, G

    1995-10-01

    We evaluated the clinical and epidemiological data of 142 HBsAg carriers. This prospective trial is part of a program of study and follow-up in HVB patients. The median age was 34.58 years old, males 56.3%. The average follow-up was 32.4 months. Complete clinical history, routine analysis, liver function tests, alfa-fetoprotein, serology for HVB, HCV and HDV and abdominal ecography were done in all patients. DNA-HVB was done only in special cases. Patients with less than 6 months of follow-up were excluded. The 118 remaining carriers were classified into two groups, depending on ALT values. Group 1 (normal ALT): included 98 carriers, 3 of them developed an active chronic hepatitis that was treated with interferon. A small CHC was diagnosed in another patient and it was resected. Group 2 (elevated ALT): included 20 carriers, only 9 of them agreed to biopsy and we found severe hepatic lesions in 4 of them. No group presented coinfection with HCV or HDV. No patient died. We conclude that the study and follow-up of asymptomatic HBsAg carriers permits an early diagnosis and treatment of the complications of this pathology (chronic hepatitis, CHC, etc); in our study, three patients developed chronic hepatitis, successfully treated with interferon, and one small size CHC was diagnosed in another patient. The study of relatives permits also detect subclinic liver disease and facilitates vaccination to prevention transmission of this infection. PMID:8519537

  18. Morphological and physiological characteristics of transgenic cherry tomato mutant with HBsAg gene.

    PubMed

    Guan, Z J; Guo, B; Huo, Y L; Hao, H Y; Wei, Y H

    2011-08-01

    HBsAg gene was previously introduced into cherry tomato (Lycopersicum esculentum var. cerasiforme) by Agrobacterium-mediated transformation. To investigate the side effect of HBsAg gene in cherry tomato, we analyzed morphological and physiological characteristics of the transgenic mutant N244. The process was performed under field conditions. The results suggested that the mutant N244 exhibited morphological, cytological and physiological variation. First of all, compared with the wild plants NK, N244 had fleshy and dark green leaves, the fewer notches of leaf edge, more adventitious roots and barren seeds. Moreover, the chromosome of N244 were found to be triploid (n = 36) by flow cytometric analysis. Furthermore, N244 has obvious physiological alterations, as compared to NK. It was speculated that transformation of the genes probably led to ploidy variation, and further caused phenotype and physiological changes of plants. Our study will reveal side effects of the mutants, and promote cultivation of transgenic plants in the field. PMID:21954613

  19. Physical properties of the extreme Centaur and super-comet candidate 2013 AZ60

    NASA Astrophysics Data System (ADS)

    Pál, A.; Kiss, Cs.; Horner, J.; Szakáts, R.; Vilenius, E.; Müller, Th. G.; Acosta-Pulido, J.; Licandro, J.; Cabrera-Lavers, A.; Sárneczky, K.; Szabó, Gy. M.; Thirouin, A.; Sipőcz, B.; Dózsa, Á.; Duffard, R.

    2015-11-01

    We present estimates of the basic physical properties including size and albedo of the extreme Centaur 2013 AZ60. These properties have been derived from optical and thermal infrared measurements. Our optical measurements revealed a probable full period of ≈9.4 h with a shallow amplitude of 4.5%. By combining optical brightness information and thermal emission data, we are able to derive a diameter of 62.3 ± 5.3 km and a geometric albedo of 2.9%, which corresponds to an extremely dark surface. Additionally, our finding of ≳50 Jm-2 K-1 s- 1/2 for the thermal inertia is also remarkable for objects in such a distance. The results of dynamical simulations yield an unstable orbit, with a 50% probability that the target will be ejected from the solar system within 700 000 yr. The current orbit of this object and its instability could imply a pristine cometary surface. This possibility agrees with the observed low geometric albedo and red photometric colour indices for the object, which match the surface of a dormant comet well, as would be expected for a long-period cometary body approaching perihelion. Although it was approaching ever closer to the Sun, however, the object exhibited star-like profiles in each of our observations, lacking any sign of cometary activity. According to the albedo, 2013 AZ60 is a candidate for the darkest body among the known trans-Neptunian objects.

  20. An integrated autonomous rendezvous and docking system architecture using Centaur modern avionics

    NASA Technical Reports Server (NTRS)

    Nelson, Kurt

    1991-01-01

    The avionics system for the Centaur upper stage is in the process of being modernized with the current state-of-the-art in strapdown inertial guidance equipment. This equipment includes an integrated flight control processor with a ring laser gyro based inertial guidance system. This inertial navigation unit (INU) uses two MIL-STD-1750A processors and communicates over the MIL-STD-1553B data bus. Commands are translated into load activation through a Remote Control Unit (RCU) which incorporates the use of solid state relays. Also, a programmable data acquisition system replaces separate multiplexer and signal conditioning units. This modern avionics suite is currently being enhanced through independent research and development programs to provide autonomous rendezvous and docking capability using advanced cruise missile image processing technology and integrated GPS navigational aids. A system concept was developed to combine these technologies in order to achieve a fully autonomous rendezvous, docking, and autoland capability. The current system architecture and the evolution of this architecture using advanced modular avionics concepts being pursued for the National Launch System are discussed.

  1. Design, development and test of shuttle/Centaur G-prime cryogenic tankage thermal protection systems

    NASA Technical Reports Server (NTRS)

    Knoll, Richard H.; Macneil, Peter N.; England, James E.

    1987-01-01

    The thermal protection systems for the shuttle/Centaur would have had to provide fail-safe thermal protection during prelaunch, launch ascent, and on-orbit operations as well as during potential abort. The thermal protection systems selected used a helium-purged polyimide foam beneath three rediation shields for the liquid-hydrogen tank and radiation shields only for the liquid-oxygen tank (three shields on the tank sidewall and four on the aft bulkhead). A double-walled vacuum bulkhead separated the two tanks. The liquid-hydrogen tank had one 0.75-in-thick layer of foam on the forward bulkhead and two layers on the larger area sidewall. Full scale tests of the flight vehicle in a simulated shuttle cargo bay that was purged with gaseous nitrogen gave total prelaunch heating rates of 88,500 Btu/hr and 44,000 Btu/hr for the liquid-hydrogen and -oxygen tanks, respectively. Calorimeter tests on a representative sample of the liquid-hydrogen tank sidewall thermal protection system indicated that the measured unit heating rate would rapidly decrease from the prelaunch rate of approx 100 Btu/hr/sq ft to a desired rate of less than 1.3 Btu/hr/sq ft once on orbit.

  2. The 250AH/90A active lithium-thionyl chloride cell for Centaur-G application

    NASA Technical Reports Server (NTRS)

    Zolla, A. E.; Tura, D. D.

    1987-01-01

    A high rate active Li/SOCl2 cell was designed for use in a 28 volt, 250 amp-hour space battery system. The lithium battery is being considered as a replacement of its heavier silver-zinc counterpart on board the Centaur-G booster rocket which is used to launch payloads from the Space Shuttle cargo bay into deep-space. Basically a feasibility study, this development effort is demonstrating the ability of the lithium cell to deliver up to 90 amps safely at power densities of approximately 25 watts per pound. Test data on 4 prototype units is showing an energy density of 85 watt-hours per pound and 9.0 watt-hours/cu in. The cells tested typically delivered 280 to 300 amp-hours under ambient temperature test conditions using alternating continuous loads of 90, 55, and 20 amperes throughout life. Data from four cells tested are presented to demonstrate the capability of Li/SOCl2 technology for a C/3 discharge rate in active and hermetic cell units.

  3. The underlying mechanisms for the "isolated positivity for the hepatitis B surface antigen (HBsAg)" serological profile.

    PubMed

    Pondé, Robério Amorim de Almeida

    2011-02-01

    During HBV infection, four structural antigen/antibody systems are observed: hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs); the pre-S antigens associated with HBsAg particles and their antibodies; the particulate nucleocapsid antigen (HBcAg) and anti-HBc; and an antigen structurally related to HBcAg, namely HBeAg and its antibody (anti-HBe). Through the examination of this antigen-antibodies system, hepatitis B infection is diagnosed and the course of the disorder may be observed. Isolated HBsAg seropositivity is a peculiar serological pattern in HBV infection observed some times in routine laboratory. In most cases is not clear how this profile should be interpreted neither its significance. This pattern, however, may be associated with some clinical and laboratorial situations of great relevance, some of which will be addressed in this article.

  4. Quantitation of HBsAg predicts response to entecavir therapy in HBV genotype C patients

    PubMed Central

    Orito, Etsuro; Fujiwara, Kei; Kanie, Hiroshi; Ban, Tesshin; Yamada, Tomonori; Hayashi, Katsumi

    2012-01-01

    AIM: To analysis the factors that predict the response to entecavir therapy in chronic hepatitis patients with hepatitis B virus (HBV) genotype C. METHODS: Fifty patients [hepatitis B e antigen (HBeAg)-negative:HBeAg-positive = 26:24] with HBV genotype C, who received naïve entecavir therapy for > 2 years, were analyzed. Patients who showed HBV DNA levels ≥ 3.0 log viral copies/mL after 2 years of entecavir therapy were designated as slow-responders, while those that showed < 3.0 log copies/mL were termed rapid-responders. Quantitative hepatitis B surface antigen (HBsAg) levels (qHBsAg) were determined by the Architect HBsAg QT immunoassay. Hepatitis B core-related antigen was detected by enzyme immunoassay. Pre-C and Core promoter mutations were determined using by polymerase chain reaction (PCR). Drug-resistance mutations were detected by the PCR-Invader method. RESULTS: At year 2, HBV DNA levels in all patients in the HBeAg-negative group were < 3.0 log copies/mL. In contrast, in the HBeAg-positive group, 41.7% were slow-responders, while 58.3% were rapid-responders. No entecavir-resistant mutants were detected in the slow-responders. When the pretreatment factors were compared between the slow- and rapid-responders; the median qHBsAg in the slow-responders was 4.57 log IU/mL, compared with 3.63 log IU/mL in the rapid-responders (P < 0.01). When the pretreatment factors predictive of HBV DNA-negative status at year 2 in all 50 patients were analyzed, HBeAg-negative status, low HBV DNA levels, and low qHBsAg levels were significant (P < 0.01). Multivariate analysis revealed that the low qHBsAg level was the most significant predictive factor (P = 0.03). CONCLUSION: Quantitation of HBsAg could be a useful indicator to predict response to entecavir therapy. PMID:23112549

  5. Capillary acquisition devices for high-performance vehicles: Executive summary. [evaluation of cryogenic propellant management techniques using the centaur launch vehicle

    NASA Technical Reports Server (NTRS)

    Blatt, M. H.; Bradshaw, R. D.; Risberg, J. A.

    1980-01-01

    Technology areas critical to the development of cryogenic capillary devices were studied. Passive cooling of capillary devices was investigated with an analytical and experimental study of wicking flow. Capillary device refilling with settled fluid was studied using an analytical and experimental program that resulted in successful correlation of a versatile computer program with test data. The program was used to predict Centaur D-1S LO2 and LH2 start basket refilling. Comparisons were made between the baseline Centaur D-1S propellant feed system and feed system alternatives including systems using capillary devices. The preferred concepts from the Centaur D-1S study were examined for APOTV and POTV vehicles for delivery and round trip transfer of payloads between LEO and GEO. Mission profiles were determined to provide propellant usage timelines and the payload partials were defined.

  6. Young adult reference ranges for thyroid function tests on the Centaur immunoassay analyser.

    PubMed

    Alqahatani, M; Tamimi, W; Aldaker, M; Alenzi, F; Tamim, H; Alsadhan, A

    2006-01-01

    This study aims to establish reference ranges for thyroid tests in young Saudi adults using the Centaur immunoassay method. Physical examination is performed and thyroid function tests include thyroid stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3). These are performed on 291 young Saudi adults (182 [63%] females and 109 [37%] males; average age: 27 years [range 18-50]). Clinical thyroid abnormality, related symptoms and/or abnormal thyroid function tests exclude a person from the study and thus a total of 276 subjects (171 [62%] females and 105 [38%] males) are used to establish the new reference ranges. Combined female and male ranges for TSH, FT4, and FT3 were found to be 0.48-6.30 miu/L (9.00-18.62 pmol/L and 3.39-6.85 pmol/L, respectively). Mean TSH and FT4 levels were significantly different (P<0.0001) from those quoted by the manufacturer. Ranges for TSH were 0.48-6.30 miu/L (female) and 0.52-4.89 miu/L (male) (P=0.08). Female ranges for FT4 and FT3 were 9.00-17.15 pmol/L and 3.39-5.82 pmol/L, respectively. Male ranges were 9.92-18.62 pmol/L (P=0.0001) and 4.36-6.85 pmol/L (P<0.0001). The range of TSH levels in the young local Saudi population proved to be higher than that quoted by the manufacturer. FT4 range was lower and narrower than that quoted by the manufacturer. Significant differences between female and male populations suggest that partitioning of the reference ranges by gender is necessary. PMID:17201204

  7. Centaur feedline dynamics study using power spectral methods. [fundamental mode resonant frequencies of RL-10 oxygen and hydrogen feed lines

    NASA Technical Reports Server (NTRS)

    Lorenzo, C. F.

    1974-01-01

    Tests were conducted to determine the dynamic characteristics of the Centaur/RL-10 oxygen and hydrogen feedlines. The fundamental-mode resonant frequencies were determined by applying power spectral methods to noise-generated data from hot firings of the RL-10 engine. The effect of net positive suction pressure of the main feed pumps on resonant frequency characteristics was determined to be a straight-line relation. Power spectral methods were also used to determine the dynamic characteristics of the boost pumps.

  8. Distribution of hepatitis B e antigen (HBeAg) and anti-HBe in carriers with different levels of HBsAg.

    PubMed

    Nath, N; Fang, C T; Fields, H A; Doto, I L; Maynard, J E

    1980-01-01

    Blood samples from 154 asymptomatic carriers of HBsAg were studied for the presence of HbeAg and anti-HBe using techniques of rheophoresis and a micro solid phase radioimmunoassay (micro-SPRIA). The level of HBsAg in each sample was determined by titration using reverse passive hemagglutination (RPHA) test. The significance of relationship between the titer of HBsAg, HBeAg, anti-HBe, and anti-HBc were statistically analyzed. Micro-SPRIA detected almost twice as many reactives for HBeAg and anti-HBe as were found by rheophoresis; the difference in sensitivity was significant (P less than 0.001). The mean HBsAg titer of 41 samples reactive for HBeAg was 11,181, while it was 3,032 for 92 samples reactive for anti-HBe. The remaining 23 samples with no detectable HBeAg or anti-HBe had a mean HBsAg titer of 1,018. The differences in the distribution of HBsAg among the three categories is statistically significant (P less than 0.005). HBeAg was most likely to be found in samples with higher concentrations of HBsAg.

  9. Clinical utility of quantitative HBsAg in natural history and nucleos(t)ide analogue treatment of chronic hepatitis B: new trick of old dog.

    PubMed

    Tseng, Tai-Chung; Kao, Jia-Horng

    2013-01-01

    Using commercial quantitative assays, quantitative hepatitis B surface antigen (qHBsAg) has improved our understanding and management of chronic hepatitis B (CHB). The HBsAg level is highest in the immune tolerance phase, starts to decline during the immune clearance phase, and decreases slowly but progressively after hepatitis B e antigen (HBeAg) seroconversion. The HBsAg level is lowest in individuals with an inactive carrier state but higher in those who develop HBeAg-negative hepatitis. It has been shown that a reduction of HBsAg by 1 log IU/mL or more reflects improved host immune control of HBV infection. A combination of HBsAg <1000 IU/mL and HBV-DNA <2000 IU/mL can identify a 3-year inactive state in a genotype D HBeAg-negative carrier population. In the Asian-Pacific region, where HBV genotypes B and C are dominant, HBsAg levels of ≤10-100 IU/mL predict HBsAg loss over time. As to the prediction of disease progression, low-viremic carriers with HBsAg >1000 IU/mL have been shown to be at higher risks of HBeAg-negative hepatitis, cirrhosis, and hepatocellular carcinoma than those with HBsAg <1000 IU/mL. Although qHBsAg has been widely used in CHB patients receiving pegylated interferon therapy, the HBsAg decline is slow and does not correlate with HBV-DNA levels during nucleos(t)ide analogue (NUC) therapy. However, a rapid HBsAg decline during NUC therapy may identify patients who will finally clear HBsAg. A 6- to 12-monthly assessment of HBsAg level could be considered during NUC therapy. Taking these lines of evidence together, qHBsAg can complement HBV-DNA levels to optimize the management of CHB patients in our daily clinical practice.

  10. The underlying mechanisms for the "simultaneous HBsAg and anti-HBs serological profile".

    PubMed

    Pondé, R A A

    2011-11-01

    The course of HBV infection is determined by the interplay between viral replication via HBV protein production and the host's immune response. Therefore, the diagnosis of infection in clinical practice is established by the serological detection of HBV protein products as well as antibodies produced by the host. Although the serological findings for assessing the clinical course of infection are already well established, the expression of viral proteins and the dynamics of antibody production may vary during the natural course of infection. This causes the HBV infection to be occasionally associated with the presence of unusual serologic profiles, which can lead to doubts in the interpretation of results and mistaken serological diagnosis. The simultaneous detection of HBsAg and anti-HBs in the blood stream comprises an atypical serological profile, somewhat incoherent, whose significance can be complicated to establish. Outlined in this article are some immunological and molecular mechanisms which could justify the existence of this profile in which there is a great laboratorial and clinical interest.

  11. Demonstration and partial characterization of 22-nm HBsAg and Dane particles of subtype HBsAg/ady.

    PubMed

    Hess, G; Shih, J W; Arnold, W; Gerin, J L; zum Büschenfelde, K H

    1979-09-01

    The present paper describes the demonstration of d, y, w, and r HBsAg determinants in one serum. It was shown that there are two populations of HBsAg particles: HBsAg/ad and HBsAg/ady. All complete Dane particles were of subtype HBsAg/ady. Further characterization of HBsAg/ady particles did not reveal morphologic differences when they were compared with HBsAg/ad and HBsAg/ay particles. An HBsAg/ady phenotype may be the result of a double infection with hepatitis B viruses or exchanges of DNA sequences that determine HBsAg/ay and HBsAg/ad to form a new genotype. PMID:89163

  12. Demonstration and partial characterization of 22-nm HBsAg and Dane particles of subtype HBsAg/ady.

    PubMed

    Hess, G; Shih, J W; Arnold, W; Gerin, J L; zum Büschenfelde, K H

    1979-09-01

    The present paper describes the demonstration of d, y, w, and r HBsAg determinants in one serum. It was shown that there are two populations of HBsAg particles: HBsAg/ad and HBsAg/ady. All complete Dane particles were of subtype HBsAg/ady. Further characterization of HBsAg/ady particles did not reveal morphologic differences when they were compared with HBsAg/ad and HBsAg/ay particles. An HBsAg/ady phenotype may be the result of a double infection with hepatitis B viruses or exchanges of DNA sequences that determine HBsAg/ay and HBsAg/ad to form a new genotype.

  13. A PILOT EXTERNAL QUALITY ASSURANCE STUDY OF TRANSFUSION SCREENING FOR HIV, HCV AND HBSAG IN TWELVE AFRICAN COUNTRIES

    PubMed Central

    Bloch, Evan M; Shah, Avani; Kaidarova, Zhanna; Laperche, Syria; Lefrere, Jean-Jacques; van Hasselt, James; Zacharias, Peter; Murphy, Edward L

    2014-01-01

    Background and Objectives Serologic screening for the major transfusion transmissible viruses (TTV) is critical to blood safety and has been widely implemented. However, actual performance as measured by proficiency testing has not been well studied in Sub-Saharan Africa. Therefore, we conducted an external quality assessment of laboratories engaged in transfusion screening in the region. Materials and Methods Blinded test panels, each comprising 25 serum samples that were pedigreed for HIV, HBsAg, HCV and negative status, were sent to participating laboratories. The panels were tested using the laboratories’ routine donor screening methods and conditions. Sensitivity and specificity were calculated and multivariable analysis was used to compare performance against mode of testing, country and infrastructure. Results A total of 12 African countries and 44 laboratories participated in the study. The mean (range) sensitivities for HIV, HBsAg and HCV were 91.9% (14.3-100), 86.7% (42.9-100) and 90.1% (50-100), respectively. Mean specificities for HIV, HBsAg and HCV were 97.7%, 97% and 99.5% respectively. After adjusting for country and infrastructure, rapid tests had significantly lower sensitivity than enzyme immunoassays (EIA) for both HBsAg (p<0.0001) and HCV (p<0.05). Sensitivity also varied by country and selected infrastructure variables. Conclusion While specificity was high, sensitivity was more variable and deficient in a substantial number of testing laboratories. These findings underscore the importance of proficiency testing and quality control, particularly in Africa where TTV prevalence is high. PMID:25052195

  14. Optimization of in vitro HBV replication and HBsAg production in HuH7 cell line.

    PubMed

    Cavallone, Daniela; Moriconi, Francesco; Colombatto, Piero; Oliveri, Filippo; Bonino, Ferruccio; Brunetto, Maurizia Rossana

    2013-04-01

    The Gunther's vector-free method (GM), using PCR-amplified full length HBV-DNA (fl-HBV-DNA), is currently the best in vitro HBV replication system despite the low intracellular HBV-DNA production. The replication efficiency and HBsAg secretion of 12 isolates from HBsAg/HBeAg positive sera by GM, Monomer-Linear-Sticky-Ends-DNA (MLSE) and Monomer-Circular-Closed (MCC) were compared in HuH7 cells. Eight of twelve genomes (67%) were replication competent by GM; however direct sequencing (DS) showed that more than 80% of input DNA was undigested in spite of SapI treatment. Replication Intermediates (RI) were detected earlier (24 vs. 48h) and in higher amounts (2.51±0.32 and 6.43±0.43 fold) by MCC than GM or MLSE. By MCC 10 of 12 genomes (83%) were replication competent and 7 produced high RI levels. RI and HBsAg kinetics correlated positively in MCC (R=0.696, p=0.017 overall; R=0.928, p=0.008), but not in GM (R=-0.437, p=0.179 overall; R=-0.395, p=0.439) in genotype D isolates. In conclusion, HBV-DNA circularization prior transfection improves in vitro viral replication and replication competent HBsAg production, mimicking better the in vivo conditions.

  15. Photometric and spectroscopic evidence for a dense ring system around Centaur Chariklo

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Pinilla-Alonso, N.; Ortiz, J. L.; Alvarez-Candal, A.; Sicardy, B.; Santos-Sanz, P.; Morales, N.; Colazo, C.; Fernández-Valenzuela, E.; Braga-Ribas, F.

    2014-08-01

    Context. A stellar occultation observed on 3rd June 2013 revealed the presence of two dense and narrow rings separated by a small gap around the Centaur object (10 199) Chariklo. The composition of these rings is not known. We suspect that water ice is present in the rings, as is the case for Saturn and other rings around the giant planets. Aims: In this work, we aim to determine if the variability in the absolute magnitude of Chariklo and the temporal variation of the spectral ice feature, even when it disappeared in 2007, can be explained by an icy ring system whose aspect angle changes with time. Methods: We explained the variations on the absolute magnitude of Chariklo and its ring by modeling the light reflected by a system as the one described above. Using X-shooter at VLT, we obtained a new reflectance spectra. We compared this new set of data with the ones available in the literature. We showed how the water ice feature is visible in 2013 in accordance with the ring configuration, which had an opening angle of nearly 34° in 2013. Finally, we also used models of light scattering to fit the visible and near-infrared spectra that shows different characteristics to obtain information on the composition of Chariklo and its rings. Results: We showed that absolute photometry of Chariklo from the literature and new photometric data that we obtained in 2013 can be explained by a ring of particles whose opening angle changes as a function of time. We used the two possible pole solutions for the ring system and found that only one of them, α = 151.30 ± 0.5, δ = 41.48 ± 0.2° (λ = 137.9 ± 0.5, β = 27.7 ± 0.2°), provides the right variation of the aspect angle with time to explain the photometry, whereas the other possible pole solution fails to explain the photometry. From spectral modeling, we derived the composition of the Chariklo surface and that of the rings using the result on the pole solution. Chariklo surface is composed with about 60% of amorphous

  16. Epidemiological characteristics of the carriers with coexistence of HBsAg and anti-HBs based on a community cohort study.

    PubMed

    Pu, Z; Li, D; Wang, A; Su, H; Shao, Z; Zhang, J; Ji, Z; Gao, J; Choi, B C K; Yan, Y

    2016-04-01

    The coexistence of HBsAg and anti-HBs is an atypical serological pattern in HBV infection. There is no epidemiological characteristics of this serological pattern in the community and there is controversy over the molecular mechanisms underlying this pattern. We investigated the epidemiological characteristics of the carriers with HBsAg and anti-HBs in a longitudinal community cohort study. The prevalence of this atypical serological pattern was 2.93% (122/4169) in HBsAg-positive populations. The prevalence progressively increased with age from 40 to 70 years old. The rate of HBeAg positive and detectable HBV DNA were both significantly higher in carriers with this pattern than in carriers who were HBsAg positive but anti-HBs negative (26/122 verse 598/4047, P = 0.046; 86/122 verse 275/529,P < 0.001). After 1 year of follow-up, 85.19% of the carriers still had coexistence HBsAg and anti-HBs, 14.81% of the carriers lost their anti-HBs. Viral sequencing showed that carriers with coexistence of HBsAg and anti-HBs had higher numbers of residue changes within the S gene than carriers who were HBsAg positive but anti-HBs negative (2.42 verse 1.33 changes per 100 residues, P < 0.05). Hence, the coexistence of HBsAg and anti-HBs is a unique serological pattern which may be associated with an increased risk of adverse clinical outcome and may be related to HBsAg immune variants which have genotypic heterogeneity.

  17. Stability and reproducibility of ADVIA 120-measured red blood cell and platelet parameters in dogs, cats, and horses, and the use of reticulocyte haemoglobin content (CH(R)) in the diagnosis of iron deficiency.

    PubMed

    Prins, M; van Leeuwen, M W; Teske, E

    2009-04-01

    Modern laser-based haematology analysers such as the ADVIA 120 have species-specific software and offer the possibility of assessing new haematological parameters. These parameters have yet to be evaluated, and as these analysers are often used in referral laboratories, it is important to know whether the values of haematological parameters change during sample transport. Therefore, samples of EDTA-anticoagulated blood from nine healthy dogs and EDTA- and citrate-anticoagulated blood from six healthy horses were collected and stored at room temperature for 72 and 48 hours, respectively. In canine samples, WBC and the red blood cell parameters Hb, Hb(cell), Ht, MCV, and MCHC changed significantly after only 24 hours of storage. Thus if canine blood samples need to be stored for 24 hours or longer, Hb, RBC, and MCH would appear to be more reliable parameters than Ht, Hb(cell), MCV, and MCHC. The cytoplasmic haemoglobin content (CH(R)) remained stable up to 48 hours. Both dog and horse platelet numbers were stable over time when blood was anticoagulated with EDTA. Of the platelet-derived parameters, MPC was already significantly lower 2 hours after collection of equine blood samples and was also significantly lower 24 hours after collection of canine blood samples. In contrast, MPV levels were significantly higher 48 hours after sample collection. Initial platelet numbers and platelet parameters were significantly different in citrate-anticoagulated blood and EDTA-anticoagulated blood, and platelet numbers and MPM decreased significantly in citrate-anticoagulated blood samples after only 4 hours of storage. After reference intervals for CH(R) had been established using samples from 53 non-anaemic dogs and 150 non-anaemic cats, the use of CH(R) to detect iron deficiency anaemia was tested in 63 dogs and 55 cats with different diseases. With the help of ROC curves, the optimal cut-off point was determined to be 1.22 fmol in dogs and 0.88 fmol in cats, resulting in a

  18. Delayed type hypersensitivity (DTH) skin reaction to hepatitis B surface antigen (HBsAg) in patients with type B acute and chronic hepatitis.

    PubMed Central

    Nagafuchi, S; Kashiwagi, S; Hayashi, S; Inoue, T; Imayama, S; Takeshita, M; Kikuchi, M

    1985-01-01

    Skin reactivity to HBsAg was studied in patients with type B acute and chronic hepatitis and in healthy controls. HBsAg preparations containing 50 micrograms/ml of antigen both with and without alum elicited positive skin reactions in all seven anti-HBs+ persons. Histological examination of skin tissue from the reactive area using monoclonal antibodies to the cell surface of lymphocytes revealed accumulation of Leu-3a positive lymphocytes, showing that the inflammation was a typical delayed type hypersensitivity (DTH) reaction. Irrespective of the presence of HBeAg and anti-HBe, patients with chronic type B hepatitis responded clearly to PPD and SK/SD antigens, whereas they did not exhibit DTH skin reactivity to HBsAg. In contrast, although patients with acute type B hepatitis did not exhibit specific DTH a reaction to HBsAg in the acute period, they began to develop DTH skin reactivity to HBsAg in the convalescent phase of the disease preceding the appearance of anti-HBs antibody. It is suggested that DTH reaction to HBsAg might play an important role in the pathogenesis of type B viral hepatitis. Images Fig. 2 PMID:4075587

  19. Propulsion system tests on a full scale Centaur vehicle to investigate 3-burn mission capability of the D-lT configuration

    NASA Technical Reports Server (NTRS)

    Groesbeck, W. A.; Baud, K. M.; Lacovic, R. F.; Tabata, W. K.; Szabo, S. V., Jr.

    1974-01-01

    Propulsion system tests were conducted on a full scale Centaur vehicle to investigate system capability of the proposed D-lT configuration for a three-burn mission. This particular mission profile requires that the engines be capable of restarting and firing for a final maneuver after a 5-1/2-hour coast to synchronous orbit. The thermal conditioning requirements of the engine and propellant feed system components for engine start under these conditions were investigated. Performance data were also obtained on the D-lT type computer controlled propellant tank pressurization system. The test results demonstrated that the RL-10 engines on the Centaur vehicle could be started and run reliably after being thermally conditioned to predicted engine start conditions for a one, two and three burn mission. Investigation of the thermal margins also indicated that engine starts could be accomplished at the maximum predicted component temperature conditions with prestart durations less than planned for flight.

  20. Tracking and Data Relay Satellite System configuration and tradeoff study. Volume 3: Atlas Centaur launched TDRSS. Part 2: Final Report, 22 August 1972 - 1 April 1973

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Configuration data and design information for the Atlas Centaur launched configuration are presented. Overall system definition, operations and control, and telecommunication service system, including link budgets, are discussed. A brief description of the user telecommunications equipment and ground station is presented. A summary description of the TDR spacecraft and all the subsystems is included. The data presented are largely in tabular form. A brief treatment of an optional configuration with enhanced telecommunications service is described.

  1. Immune Responses to HBsAg Conjugated to Protein D of Non-Typeable Haemophilus influenzae in Mice

    PubMed Central

    Su, Qiudong; Yi, Yao; Qiu, Feng; Lu, Xuexin; Ding, Junying; Jia, Zhiyuan; Tian, Ruiguang; Gao, Yan; Bi, Shengli

    2015-01-01

    Background Hepatitis B vaccine that contains an aluminum hydroxide adjuvant induces apoptotic death of Hepa 1–6 cells. Difficult-to-degrade chemical additives in vaccines effectively enhance vaccine immunogenicity, but also affect the host tissue. Identification of bio-molecules that are readily degraded and compatible in vivo as an adjuvant is important for vaccine research. The hapten–carrier effect suggests that stimulation of helper T (Th) cells by carrier adjuvants is feasible. Protein D (PD) of non-typeable Haemophilus influenzae covalently conjugated to some polysaccharide vaccines has been confirmed to convert T-cell independent (TI) antigens into T-cell dependent (TD) antigens, and elicit strong T-cell responses ultimately. Herein, we would substitube PD for aluminum hydroxide adjuvant in Hepatitis B vaccine. Methods and results Truncated PD (amino acids 20–364) was expressed in Escherichia coli and purified by (NH4)2SO4 precipitation and DEAE chromatography. After evaluation of antigenicity by western blotting, PD was covalently conjugated to yeast-derived recombinant HBsAg by cross-linking with glutaraldehyde. Intramuscular immunization with the conjugate induced higher level of HBsAg-specific antibody than did HBsAg alone (p < 0.05), and was comparable to commercial Hepatitis B vaccine. During the surveillance period (days 35–105), anti-HBs titers were hold high. Moreover, the conjugated vaccine enhanced Th1 immune responses, while Th2 responses were also activated and induced an antibody response, as determined by IFN-γ ELISPOT and IgG1/IgG2a ratio assays. Conclusions Recombinant truncated PD covalently conjugated to HBsAg antigen enhanced the immunogenicity of the antigen in mice simultaneously by humoral and cellular immune response, which would facilitate therapeutic hepatitis B vaccines. PMID:25689855

  2. Characterization of C69R variant HBsAg: effect on binding to anti-HBs and the structure of virus-like particles.

    PubMed

    Hadiji-Abbes, Nadia; Mihoubi, Wafa; Martin, Marta; Karakasyan-Dia, Carole; Frikha, Fakher; Gergely, Csilla; Jouenne, Thierry; Gargouri, Ali; Mokdad-Gargouri, Raja

    2015-10-01

    Several variants of the major "a" determinant of the HBsAg, the main target of HBV neutralization by antibodies, have been described. However, mutations outside this region have not been as thoroughly investigated. During the genotyping of HBV from Tunisian patients with chronic hepatitis B, we identified a variant with a C69R substitution in the cytosolic loop of the S protein, resulting in a change in the hydrophobicity profile compared to the wild-type HBsAg. Wild-type and mutant HBsAgs were produced in Saccharomyces cerevisiae and recombinant proteins were tested for their ability to correctly self-assemble into virus-like particles (VLPs), and their ability to bind to HBs antibodies. The C69R substitution resulted in a decrease in binding to commercial anti-HBs antibodies, and although the variant appeared to assemble properly into VLPs, the average size of the particles was larger than that of the wild-type HBsAg. Prediction of the tertiary structure of the C69R mutant revealed a change in the first (aa 60-70) and the second loop (aa 110 to 120) compared to the wild-type protein. Furthermore, we showed by an isothermal titration calorimetry assay that the interaction between the wild-type HBsAg and the anti-HBs antibody was exothermic, whereas that with the mutant C69R was endothermic, indicating an effect on the binding affinity.

  3. Detection of HbsAg and hATIII genetically modified goats (Caprahircus) by loop-mediated isothermal amplification.

    PubMed

    Tao, Chenyu; Zhang, Qingde; Zhai, Shanli; Liu, Bang

    2013-11-01

    In this study, sensitive and rapid detection systems were designed using a loop-mediated isothermal amplification (LAMP) method to detect the genetically modified goats. A set of 4 primers were designed for each exogenous nucleic acids HBsAg and hATIII. The DNA samples were first amplified with the outer and inner primers and released a single-stranded DNA,of which both ends were stem-loop structure. Then one inner primer hybridized with the loop, and initiated displacement synthesis in less than 1 h. The result could be visualized by both agarose gel electrophoresis and unaided eyes directly after adding SYBR GREEN 1. The detection limit of LAMP was ten copies of target molecules, indicating that LAMP was tenfold more sensitive than the classical PCR. Furthermore, all the samples of genetically modified goats were tested positively by LAMP, and the results demonstrated that the LAMP was a rapid and sensitive method for detecting the genetically modified organism.

  4. Discovery of a New Retrograde Trans-Neptunian Object: Hint of a Common Orbital Plane for Low Semimajor Axis, High-inclination TNOs and Centaurs

    NASA Astrophysics Data System (ADS)

    Chen, Ying-Tung; Lin, Hsing Wen; Holman, Matthew J.; Payne, Matthew J.; Fraser, Wesley C.; Lacerda, Pedro; Ip, Wing-Huen; Chen, Wen-Ping; Kudritzki, Rolf-Peter; Jedicke, Robert; Wainscoat, Richard J.; Tonry, John L.; Magnier, Eugene A.; Waters, Christopher; Kaiser, Nick; Wang, Shiang-Yu; Lehner, Matthew

    2016-08-01

    Although the majority of Centaurs are thought to have originated in the scattered disk, with the high-inclination members coming from the Oort cloud, the origin of the high-inclination component of trans-Neptunian objects (TNOs) remains uncertain. We report the discovery of a retrograde TNO, which we nickname “Niku,” detected by the Pan-STARRS 1 Outer Solar System Survey. Our numerical integrations show that the orbital dynamics of Niku are very similar to that of 2008 KV42 (Drac), with a half-life of ˜500 Myr. Comparing similar high-inclination TNOs and Centaurs (q > 10 au, a < 100 au, and i > 60°), we find that these objects exhibit a surprising clustering of ascending node, and occupy a common orbital plane. This orbital configuration has high statistical significance: 3.8-σ. An unknown mechanism is required to explain the observed clustering. This discovery may provide a pathway to investigating a possible reservoir of high-inclination objects.

  5. Efficacy of Post-Exposure Prophylaxis in Infants Born to HBsAg Positive Mothers in Iran; Is It Authentic?

    PubMed Central

    Ahmadinejad, Zahra; Abdi Liae, Zahra; Salehizadeh, Saideh; Mansori, Sedighe; Alijani, Neda

    2016-01-01

    Background Hepatitis B infection is a universal concern. This infection can lead to chronic liver disease and hepatocellular carcinoma. Neonates born to HBsAg-positive mothers are at high risk of chronic hepatitis B virus (HBV) infection, especially for HBeAg-positive mothers or neonates who have not received hepatitis B immunoglobulin (HBIg) and HBV vaccines. Objectives The aim of this study was to evaluate the efficacy of post-exposure prophylaxis in these infants to prevent infection. Patients and Methods Thirty-eight infants born to HBsAg-positive mothers between September 2006 and September 2013 were followed. The investigation evaluated whether the standard prevention protocol of neonatal HBV transmission including HBIg at birth and receiving three doses of vaccine at birth and 2 and 6 months of age was performed, followed by post-vaccination tests (evaluation of HBsAg and HBsAb titer at 9 to 18 months of age) to determine subsequent infection. HBsAb titer ≥ 10 was considered as criterion for effectiveness of the prophylaxis procedure. The acquired data were analyzed using SPSS software (Version 18). The results are reported in descriptive tabulations. Results Ninety seven percent (97%) of infants received HBIg at birth in the hospital. Generally, all of them received the first, second and third doses of vaccine at birth, 2 months, and 6 months after birth, respectively. Information for 35 mothers infected with HBV and 38 infants was available. The mean age of the mothers was 30.3 years. The results indicated that 20% of mothers were HBeAg positive. HBsAg was positive in one (2.6%) infant born to an HBeAg-positive mother. Around 94% of infants’ HBsAb titers were ≥ 10, and 5.8% were reported as non-responders. Conclusions The vertical transmission prevention program used in the study population in Tehran, which had an appropriate sample size, is effective. Additional doses of the vaccine can be useful in raising the effectiveness of immunoprophylaxis for

  6. Immunofluorescence detection of new antigen-antibody system (delta/anti-delta) associated to hepatitis B virus in liver and in serum of HBsAg carriers.

    PubMed Central

    Rizzetto, M; Canese, M G; Aricò, S; Crivelli, O; Trepo, C; Bonino, F; Verme, G

    1977-01-01

    A new antigen-antibody system associated with the hepatitis B virus and immunologically distinct from the HB surface, core, and e systems is reported. The new antigen, termed delta, was detected by direct immunofluorescence only in the liver cell nuclei of patients with HBsAg positive chronic liver disease. At present, the intrahepatic expression of HBcAg and delta antigen appears to be mutually exclusive. No ultrastructural aspect corresponding to the delta antigen could be identified under the electron microscope. delta antibody was found in the serum of chronic HBsAg carriers, with a higher prevalence in patients with liver damage. The nuclear fluorescence patterns of HBcAg and delta antigen were similar; it is only possible to discriminate between the two antigens by using the respective specific antisera. Images Figure PMID:75123

  7. MicroRNA-122 as a predictor of HBsAg seroclearance in hepatitis B and C dual infected patients treated with interferon and ribavirin

    PubMed Central

    Yen, Yi-Hao; Huang, Chao-Min; Wei, Kuo-Liang; Wang, Jing-Houng; Lu, Sheng-Nan; Lee, Chuan-Mo; Hung, Chao-Hung; Chen, Chien-Hung; Tseng, Po-Lin; Chang, Kuo-Chin; Tsai, Ming-Chao; Lin, Ming-Tsung; Wu, Cheng-Kun; Yang, Cheng-Hong; Moi, Sin-Hua; Cho, Chung-Lung; Hu, Tsung-Hui

    2016-01-01

    It has been demonstrated that microRNA-122 (miR-122) plays key roles in the modulation of hepatitis B virus (HBV) replication. This study examined the role of miR-122 in patients with hepatitis C virus (HCV)-HBV dual infection with active hepatitis C who received pegylated interferon-α and ribavirin dual therapy. We enrolled 121 patients with HCV-HBV dual infection after dual therapy. Stored serum was collected before treatment. RT-PCR was used to analyze miR-122. HBsAg seroclearance was noted in 37 (30.1%) cases during a median follow-up period of 5.4 years. miR-122 was significantly lower in HBsAg seroclearance patients than in non-HBsAg seroclearance patients (P < 0.014). Multivariate analysis showed that miR-122 was an independent factor of HBsAg seroclearance (OR: 0.30, 95% CI: 0.09–0.98, P = 0.046). miR-122 was significantly higher in patients who were qHBsAg > 100 IU/mL versus ≤100 IU/mL (P < 0.001). We concluded that in patients with HBV-HCV dual infection with active hepatitis C, miR-122 was associated with HBsAg seroclearance after therapy and qHBsAg level before therapy, indicating that miR-122 plays key roles in modulating HBV replication. PMID:27665934

  8. Defective antigen presentation by monocytes in ESRD patients not responding to hepatitis B vaccination: impaired HBsAg internalization and expression of ICAM-1 and HLA-DR/Ia molecules

    PubMed Central

    Barth, C.; Pollok, M.; Michałkiewicz, J.; Madaliński, K.; Maciejewski, J.; Baldamis, C. A.

    1995-01-01

    This study was undertaken to evaluate the monocyte function of uraemic non-responders to hepatitis B vaccination. Therefore, some parameters concerning antigen processing by monocytes (Mo) as antigen presenting cells (APC) were analysed. It was found that in uraemic non-responders, (1) the internalization of HBsAg by monocytes was significantly decreasjed—HBsAg complexed with specific IgG or as immune complex isolated from patients is better internalized compared with free HBsAg; (2) during antigen presentation the expression of adhesion (ICAM-1) and accessory (HLA-DR/Ia) molecules was significantly decreased in uraemic patients, especially in non-responders; and (3) impaired internalization of HBsAg as well as a decrease in ICAM-1 and HLA-DR/Ia expression, correlated well with the blunted proliferation of CD4+ T cells stimulated by autologous monocytes induced by HBsAg. PMID:18475616

  9. Discovery of A New Retrograde Trans-Neptunian Object: Hint of A Common Orbital Plane for Low Semi-Major Axis, High Inclination TNOs and Centaurs

    NASA Astrophysics Data System (ADS)

    Chen, Ying-Tung; Lin, Hsing-Wen; Holman, Matthew J.; Payne, Matthew John; Fraser, Wesley Cristopher; Lacerda, Pedro; Ip, Wing-Huen; Pan-STARRS 1 Builders

    2016-10-01

    The origin of high inclination objects beyond Jupiter, including trans-Neptunian objects (TNOs) and Centaurs, remains uncertain. We report the discovery of a retrograde TNO, which we nickname "Niku", detected by the Pan-STARRS 1 Outer Solar System Survey. The numerical integrations show that the orbital dynamics of Niku are very similar to those of 2008 KV42 (Drac), with a half-life of ~ 500 Myr and analogous orbital evolution. Comparing similar high inclination members announced by the Minor-Planet Center (q > 10 AU, a < 100 AU and i > 60), we find these objects exhibit a surprising clustering of ascending node, populating a common orbital plane. The statistical significance of 3.8-sigma suggests it is unlikely to be coincidental. An unknown mechanism is required to explain the observed clustering. This discovery may provide a pathway to investigating a possible reservoir of high-inclination objects.

  10. "TNOs are Cool": A survey of the trans-Neptunian region. IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations

    NASA Astrophysics Data System (ADS)

    Lellouch, E.; Santos-Sanz, P.; Lacerda, P.; Mommert, M.; Duffard, R.; Ortiz, J. L.; Müller, T. G.; Fornasier, S.; Stansberry, J.; Kiss, Cs.; Vilenius, E.; Mueller, M.; Peixinho, N.; Moreno, R.; Groussin, O.; Delsanti, A.; Harris, A. W.

    2013-09-01

    Aims: The goal of this work is to characterize the ensemble thermal properties of the Centaurs / trans-Neptunian population. Methods: Thermal flux measurements obtained with Herschel/PACS and Spitzer/MIPS provide size, albedo, and beaming factors for 85 objects (13 of which are presented here for the first time) by means of standard radiometric techniques. The measured beaming factors are influenced by the combination of surface roughness and thermal inertia effects. They are interpreted within a thermophysical model to constrain, in a statistical sense, the thermal inertia in the population and to study its dependence on several parameters. We use in particular a Monte-Carlo modeling approach to the data whereby synthetic datasets of beaming factors are created using random distributions of spin orientation and surface roughness. Results: Beaming factors η range from values <1 to ~2.5, but high η values (>2) are lacking at low heliocentric distances (rh < 30 AU). Beaming factors lower than 1 occur frequently (39% of the objects), indicating that surface roughness effects are important. We determine a mean thermal inertia for Centaurs/ TNO of Γ = (2.5 ± 0.5) J m-2 s-1/2 K-1, with evidence of a trend toward decreasing Γ with increasing heliocentric (by a factor ~2.5 from 8-25 AU to 41-53 AU). These thermal inertias are 2-3 orders of magnitude lower than expected for compact ices, and generally lower than on Saturn's satellites or in the Pluto/Charon system. Most high-albedo objects are found to have unusually low thermal inertias. Our results suggest highly porous surfaces, in which the heat transfer is affected by radiative conductivity within pores and increases with depth in the subsurface. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Table 3 is available in electronic form at http://www.aanda.org

  11. Hepatitis B virus and hepatitis D virus in blood donors from Argentina: circulation of HBsAg and reverse transcriptase mutants.

    PubMed

    Delfino, Cecilia María; Gentile, Emiliano Alberto; Castillo, Amalia Inés; Cuestas, María Luján; Pataccini, Gabriela; Cánepa, Camila; Malan, Richard; Blejer, Jorgelina; Berini, Carolina; Eirin, María Emilia; Pedrozo, Williams; Oubiña, José Raúl; Biglione, Mirna Marcela; Mathet, Verónica Lidia

    2014-05-01

    In Argentina, current procedures to ensure the safety of the blood supply for transfusion include the serologic detection of specific blood-borne infections. The aim of this study was to evaluate the prevalence and the genetic diversity of hepatitis B virus (HBV) and hepatitis D virus (HDV) in blood donor populations from two distantly located Argentine regions. Data from 56,983 blood donations from the Favaloro Foundation, in the city of Buenos Aires (Central Region), and the Central Blood Bank of Misiones Province (Northeast Region) were analyzed. Samples that were reactive for HBsAg were analyzed for HBV-DNA characterization and HDV serological and molecular analysis. The HBV prevalence was 0.12 % for HBsAg and 1.68 % for anti-HBc antibodies in Buenos Aires, and 0.73 % and 8.55 %, respectively, in Misiones. Seventy-seven HBsAg-reactive samples were analyzed by polymerase chain reaction for HBV-DNA. Subgenotypes A2, B2, C2, F1b and F4 (Buenos Aires) and F1b and D3 (Misiones) were detected. Several mutations within the major hydrophilic region of HBsAg, the reverse transcriptase, the basal core promoter, and the precore/core were detected. HDV genotype 1 was identified in Buenos Aires. This study confirms the circulation of several HBV subgenotypes, as well as known and newly identified variants, and the presence of HDV1 in this population. A thorough investigation has to be carried out to evaluate the clinical importance of some of the documented mutations as well as those detected in the HDV1 case.

  12. Hepatitis B virus and hepatitis D virus in blood donors from Argentina: circulation of HBsAg and reverse transcriptase mutants.

    PubMed

    Delfino, Cecilia María; Gentile, Emiliano Alberto; Castillo, Amalia Inés; Cuestas, María Luján; Pataccini, Gabriela; Cánepa, Camila; Malan, Richard; Blejer, Jorgelina; Berini, Carolina; Eirin, María Emilia; Pedrozo, Williams; Oubiña, José Raúl; Biglione, Mirna Marcela; Mathet, Verónica Lidia

    2014-05-01

    In Argentina, current procedures to ensure the safety of the blood supply for transfusion include the serologic detection of specific blood-borne infections. The aim of this study was to evaluate the prevalence and the genetic diversity of hepatitis B virus (HBV) and hepatitis D virus (HDV) in blood donor populations from two distantly located Argentine regions. Data from 56,983 blood donations from the Favaloro Foundation, in the city of Buenos Aires (Central Region), and the Central Blood Bank of Misiones Province (Northeast Region) were analyzed. Samples that were reactive for HBsAg were analyzed for HBV-DNA characterization and HDV serological and molecular analysis. The HBV prevalence was 0.12 % for HBsAg and 1.68 % for anti-HBc antibodies in Buenos Aires, and 0.73 % and 8.55 %, respectively, in Misiones. Seventy-seven HBsAg-reactive samples were analyzed by polymerase chain reaction for HBV-DNA. Subgenotypes A2, B2, C2, F1b and F4 (Buenos Aires) and F1b and D3 (Misiones) were detected. Several mutations within the major hydrophilic region of HBsAg, the reverse transcriptase, the basal core promoter, and the precore/core were detected. HDV genotype 1 was identified in Buenos Aires. This study confirms the circulation of several HBV subgenotypes, as well as known and newly identified variants, and the presence of HDV1 in this population. A thorough investigation has to be carried out to evaluate the clinical importance of some of the documented mutations as well as those detected in the HDV1 case. PMID:24306325

  13. The HBsAg Prevalence Among Blood Donors From Eastern Mediterranean and Middle Eastern Countries: A Systematic Review and Meta-Analysis

    PubMed Central

    Babanejad, Mehran; Izadi, Neda; Najafi, Farid; Alavian, Seyed Moayed

    2016-01-01

    Context The world health organization (WHO) recommends that all blood donations should be screened for evidence of infections, such as hepatitis B. The present study aimed to determine the prevalence of hepatitis B surface antigen (HBsAg) in blood donors at the eastern Mediterranean region office (EMRO) of the WHO and middle eastern countries. Evidence Acquisition A meta-analysis was carried out based on the results of an electronic literature search of PubMed, Ovid, Scopus, and Google Scholar for articles published from January 1, 2000, to August 31, 2015. In accordance with a significant homogeneity test and a large value of I2, the random effects model was used to aggregate data from the studies and produce the pooled estimates using the “Metan” command. Results We included 66 eligible studies. The pooled prevalence of HBsAg in blood donors of both EMRO and middle eastern (E and M) countries was 2.03% (95% confidence interval [CI]: 1.79 – 2.26). In addition, the prevalence rates in the EMRO countries was 1.99% (95% CI: 1.84 – 2.14) and 1.62% in the Middle Eastern countries (95% CI: 1.36 – 1.88). The prevalence among blood donors with more than one study was 1.58% in Egypt, 0.58% in Iran, 0.67% in Iraq, 2.84% in Pakistan, 3.02% in Saudi Arabia, 1.68% in Turkey, and 5.05% in Yemen. Conclusions Based on the WHO classification of hepatitis B virus (HBV) prevalence, the prevalence of HBsAg in blood donors from E and M countries reached an intermediate level. However, there were low prevalence levels in some E and M countries. PMID:27226804

  14. Immunotherapy of HCC metastases with autologous T cell receptor redirected T cells, targeting HBsAg in a liver transplant patient.

    PubMed

    Qasim, Waseem; Brunetto, Maurizia; Gehring, Adam J; Xue, Shao-An; Schurich, Anna; Khakpoor, Atefeh; Zhan, Hong; Ciccorossi, Pietro; Gilmour, Kimberly; Cavallone, Daniela; Moriconi, Francesco; Farzhenah, Farzin; Mazzoni, Alessandro; Chan, Lucas; Morris, Emma; Thrasher, Adrian; Maini, Mala K; Bonino, Ferruccio; Stauss, Hans; Bertoletti, Antonio

    2015-02-01

    HBV-DNA integration frequently occurs in HBV-related hepatocellular carcinoma (HCC), but whether HBV antigens are expressed in HCC cells and can be targeted by immune therapeutic strategies remains controversial. Here, we first characterized HBV antigen expression in HCC metastases, occurring in a patient who had undergone liver transplantation for HBV-related HCC. We then deployed for the first time in HCC autologous T cells, genetically modified to express an HBsAg specific T cell receptor, as therapy against chemoresistant extrahepatic metastases. We confirmed that HBV antigens were expressed in HCC metastases (but not in the donor liver) and demonstrated that tumour cells were recognized in vivo by lymphocytes, engineered to express an HBV-specific T cell receptor (TCR). Gene-modified T cells survived, expanded and mediated a reduction in HBsAg levels without exacerbation of liver inflammation or other toxicity. Whilst clinical efficacy was not established in this subject with end-stage metastatic disease, we confirm the feasibility of providing autologous TCR-redirected therapy against HCC and advocate this strategy as a novel therapeutic opportunity in hepatitis B-associated malignancies.

  15. Reversal of B-cell hyperactivation and functional impairment is associated with HBsAg seroconversion in chronic hepatitis B patients

    PubMed Central

    Xu, Xiangsheng; Shang, Qinghua; Chen, Xinyue; Nie, Weimin; Zou, Zhengsheng; Huang, Ang; Meng, Ming; Jin, Lei; Xu, Ruonan; Zhang, Ji-Yuan; Fu, Junliang; Wang, Lifeng; Tang, Zirong; Xie, Yunbo; Yang, Xiaoming; Zhang, Zheng; Wang, Fu-Sheng

    2015-01-01

    B cells play an important role in the clearance of hepatitis B virus (HBV) and protection against reinfection. However, the functional characteristics of these cells that are associated with the outcome of chronic HBV infection remain unknown. We comprehensively investigated the frequency, phenotype, and function of peripheral B-cell subsets from CHB patients in different phases: immune tolerance (IT), immune activation (IA), immune clearance (IC), responders with HBsAg seroconversion (resolved patients, RP), and healthy controls (HC). IA patients displayed lower percentages of peripheral blood memory B cells compared with the other groups. Overall polyclonal activation of B cells, indicated by higher levels of activation markers and secretion of IgG and IgM, was observed in IA patients. This B-cell hyperactivation could be induced by increased IFN-α and soluble CD40 ligands in IA patients. Notably, the expression of the co-stimulator molecule CD80 and serum HBsAb and the frequency of HBsAg-specific B cells were significantly decreased in IT, IA, and IC patients compared with HC subjects. More importantly, the B-cell hyperactivation, co-stimulatory molecule downregulation and HBsAg-specific B-cell impairment were reversed in RP patients. The reversal of B-cell hyperactivation and functional impairment is associated with HBsAg seroconversion in chronic hepatitis B patients. PMID:25849120

  16. A new fluorescent based screening system for high throughput screening of drugs targeting HBV-core and HBsAg interaction.

    PubMed

    Suresh, V; Krishnakumar, K A; Asha, V V

    2015-03-01

    The existing screening systems for anti-hepatitis B virus (anti-HBV) drug discovery is time-consuming mainly due to the laborious detection system it is using. A new fluorescence based screening system for high throughput anti-HBV drug discovery was created by tagging hepatitis B surface antigen (HBsAg) with monomeric red fluorescent protein and hepatitis B virus (HBV) core protein with enhanced green fluorescent protein. The two constructs were co-transfected on to Hep3B cells and the transfection was stabilized by fluorescent activated cell sorter (FACS). The fusion proteins expressed through the secretory protein pathway as evidenced by localization with ER-Tracker and tubulin tracker. The new system has given analogues results like that of conventional enzyme-linked immunosorbent assay (ELISA). Hence it can be of very high potential for large scale drug screening systems.

  17. Construction and immunological evaluation of truncated hepatitis B core particles carrying HBsAg amino acids 119–152 in the major immunodominant region (MIR)

    SciTech Connect

    Su, Qiudong; Yi, Yao; Guo, Minzhuo; Qiu, Feng; Jia, Zhiyuan; Lu, Xuexin; Meng, Qingling; Bi, Shengli

    2013-09-13

    Highlights: •The conformational HBV neutralization antigen domain was successfully displayed on the surface of truncated HBc particles. •Appropriate dialysis procedures to support the renaturing environment for the protein refolding. •Efficient purification procedures to obtain high purity and icosahedral particles of mosaic HBV antigen. •Strong immune responses not only including neutralization antibody response but also Th1 cell response were induced in mice. -- Abstract: Hepatitis B capsid protein expressed in Escherichia coli can reassemble into icosahedral particles, which could strongly enhance the immunogenicity of foreign epitopes, especially those inserted into its major immunodominant region. Herein, we inserted the entire ‘α’ antigenic determinant amino acids (aa) 119–152 of HBsAg into the truncated HBc (aa 1–144), between Asp{sup 78} and Pro{sup 79}. Prokaryotic expression showed that the mosaic HBc was mainly in the form of inclusion bodies. After denaturation with urea, it was dialyzed progressively for protein renaturation. We observed that before and after renaturation, mosaic HBc was antigenic as determined by HBsAg ELISA and a lot of viruslike particles were observed after renaturation. Thus, we further purified the mosaic viruslike particles by (NH{sub 4}){sub 2}SO{sub 4} precipitation, DEAE chromatography, and Sepharose 4FF chromatography. Negative staining electron microscopy demonstrated the morphology of the viruslike particles. Immunization of Balb/c mice with mosaic particles induced the production of anti-HBs antibody and Th1 cell immune response supported by ELISPOT and CD4/CD8 proportions assay. In conclusion, we constructed mosaic hepatitis core particles displaying the entire ‘α’ antigenic determinant on the surface and laid a foundation for researching therapeutic hepatits B vaccines.

  18. A single dose of oral DNA immunization delivered by attenuated Salmonella typhimurium down-regulates transgene expression in HBsAg transgenic mice.

    PubMed

    Zheng, Bo Jian; Ng, Mun Hon; Chan, Kwok Wah; Tam, Sidney; Woo, Patrick C Y; Ng, Sze Park; Yuen, Kwok Yung

    2002-11-01

    The efficacy of immunization with Salmonella typhimurium aroA to deliver the plasmid pRc/CMV-HBsAg (i.e. an oral DNA vaccine) was compared with that of intramuscular immunization with the same plasmid DNA, and with recombinant HBsAg protein, in a HBsAg transgenic mouse model. A single dose of oral DNA vaccine evoked vigorous Th1 cell and CTL responses and production of IgG2 subclass of anti-HBs after 2 weeks, and this was accompanied by a transient hepatitic flare with elevated alanine aminotransferase in the first 3 weeks. Concomitantly, the level of HBsAg-mRNA in liver tissues decreased by more than fourfold and viral-antigen expression was curtailed markedly in hepatocytes compared with controls. Hepatitic flare subsided after 3 weeks, but suppression of the transgene expression was continued in the absence of overt liver pathology for the remaining duration of the experiment (i.e. 12 weeks), and possibly beyond. The other vaccines could also break immune tolerance, but this was achieved only after repeated booster doses of the respective vaccines, and they did not affect transgene expression, or induce hepatic flare. We previously showed in non-transgenic mice that immunization by the oral DNA vaccine is achieved by an active intestinal infection with a bacterial carrier that is an adept intracellular parasite, and the immune response to the vaccination is orchestrated by phagocytic APC. Our present findings further implicated that the combined effects of an innate and a specific immune response induced by oral DNA vaccination are crucial in down-regulating HBsAg-transgene expression in hepatocytes.

  19. Photometry of Centaurs and trans-Neptunian objects: 2060 Chiron (1977 UB), 10199 Chariklo (1997 CU26), 38628 Huya (2000 EB173), 28978 Ixion (2001 KX76), and 90482 Orcus (2004 DW)

    NASA Astrophysics Data System (ADS)

    Galiazzo, M.; de la Fuente Marcos, C.; de la Fuente Marcos, R.; Carraro, G.; Maris, M.; Montalto, M.

    2016-07-01

    Both Centaurs and trans-Neptunian objects (TNOs) are minor bodies found in the outer Solar System. Centaurs are a transient population that moves between the orbits of Jupiter and Neptune, and they probably diffused out of the TNOs. TNOs move mainly beyond Neptune. Some of these objects display episodic cometary behaviour; a few percent of them are known to host binary companions. Here, we study the light-curves of two Centaurs—2060 Chiron (1977 UB) and 10199 Chariklo (1997 CU26)—and three TNOs—38628 Huya (2000 EB173), 28978 Ixion (2001 KX76), and 90482 Orcus (2004 DW)—and the colours of the Centaurs and Huya. Precise, ˜1~%, R-band absolute CCD photometry of these minor bodies acquired between 2006 and 2011 is presented; the new data are used to investigate the rotation rate of these objects. The colours of the Centaurs and Huya are determined using BVRI photometry. The point spread function of the five minor bodies is analysed, searching for signs of a coma or close companions. Astrometry is also discussed. A periodogram analysis of the light-curves of these objects gives the following rotational periods: 5.5±0.4~h for Chiron, 7.0± 0.6~h for Chariklo, 4.45±0.07~h for Huya, 12.4±0.3~h for Ixion, and 11.9±0.5~h for Orcus. The colour indices of Chiron are found to be B-V=0.53±0.05, V-R=0.37±0.08, and R-I=0.36±0.15. The values computed for Chariklo are V-R=0.62±0.07 and R-I=0.61±0.07. For Huya, we find V-R=0.58±0.09 and R-I=0.64±0.20. Our rotation periods are similar to and our colour values are consistent with those already published for these objects. We find very low levels of cometary activity (if any) and no sign of close or wide binary companions for these minor bodies.

  20. Immune response elicited by an intranasally delivered HBsAg low-dose adsorbed to poly-ε-caprolactone based nanoparticles.

    PubMed

    Jesus, Sandra; Soares, Edna; Costa, João; Borchard, Gerrit; Borges, Olga

    2016-05-17

    Among new strategies to increase hepatitis B virus (HBV) vaccination, especially in developing countries, the development of self-administered vaccines is considered one of the most valuable. Nasal vaccination using polymeric nanoparticles (NPs) constitutes a valid approach to this issue. In detail, poly-ε-caprolactone (PCL)/chitosan NPs present advantages as a mucosal vaccine delivery system: the high resistance of PCL against degradation in biological fluids and the mucoadhesive and immunostimulatory properties of chitosan. In vitro studies revealed these NPs were retained in a mucus-secreting pulmonary epithelial cell line and were capable of entering into differentiated epithelial cells. The intranasal (IN) administration of 3 different doses of HBsAg (1.5 μg, 5 μg and 10 μg) adsorbed on a fixed amount of PCL/chitosan NPs (1614 μg) generated identical titers of serum anti-HBsAg IgG and anti-HBsAg sIgA in mice nasal secretions. Besides other factors, the NP surface characteristics, particularly, zeta potential differences among the administered formulations are believed to be implicated in the outcome of the immune response generated.

  1. Effect of a polysaccharide from Poria cocos on humoral response in mice immunized by H1N1 influenza and HBsAg vaccines.

    PubMed

    Wu, Yajun; Li, Shuai; Li, Haixia; Zhao, Chunzhi; Ma, Hao; Zhao, Xiunan; Wu, Junhua; Liu, Kunlu; Shan, Junjie; Wang, Yuxia

    2016-10-01

    Poria cocos has a long history of medicinal use in China. Polysaccharides and their derivatives in the medicine exhibit many beneficial biological activities including anticancer, anti-inflammatory, antioxidant and antiviral activities. In this study, a new polysaccharide (PCP-II) was isolated from sclerotium of Poria cocos. Its physico-chemical characters were identified and its adjuvant activity was investigated in mice co-immunized with H1N1 influenza vaccine and hepatitis B surface antigen (HBsAg). The results revealed that PCP-II has a molecular weight of 29.0kDa. It was composed of fucose, mannose, glucose and galactose in molar ration of 1.00:1.63:0.16:6.29 respectively. Pharmacological data demonstrated that PCP-II increased antigen-specific antibody levels in mice immunized with influenza vaccine. PCP-II also elicited anti-HBsAg antibodies at significantly higher titers and generated robust and durable immunity compared to mice immunized with HBsAg-alum following two administrations. PCP-II improved proliferation of splenocytes, stimulated IL-12p70 and TNF-α productions in dendritic cells and macrophages respectively. These results suggested that PCP-II-adjuvanted vaccines enhanced humoral and cellular immunity. PCP-II could be developed as an efficacious adjuvant in human and animal vaccines. PMID:27185068

  2. Effect of a polysaccharide from Poria cocos on humoral response in mice immunized by H1N1 influenza and HBsAg vaccines.

    PubMed

    Wu, Yajun; Li, Shuai; Li, Haixia; Zhao, Chunzhi; Ma, Hao; Zhao, Xiunan; Wu, Junhua; Liu, Kunlu; Shan, Junjie; Wang, Yuxia

    2016-10-01

    Poria cocos has a long history of medicinal use in China. Polysaccharides and their derivatives in the medicine exhibit many beneficial biological activities including anticancer, anti-inflammatory, antioxidant and antiviral activities. In this study, a new polysaccharide (PCP-II) was isolated from sclerotium of Poria cocos. Its physico-chemical characters were identified and its adjuvant activity was investigated in mice co-immunized with H1N1 influenza vaccine and hepatitis B surface antigen (HBsAg). The results revealed that PCP-II has a molecular weight of 29.0kDa. It was composed of fucose, mannose, glucose and galactose in molar ration of 1.00:1.63:0.16:6.29 respectively. Pharmacological data demonstrated that PCP-II increased antigen-specific antibody levels in mice immunized with influenza vaccine. PCP-II also elicited anti-HBsAg antibodies at significantly higher titers and generated robust and durable immunity compared to mice immunized with HBsAg-alum following two administrations. PCP-II improved proliferation of splenocytes, stimulated IL-12p70 and TNF-α productions in dendritic cells and macrophages respectively. These results suggested that PCP-II-adjuvanted vaccines enhanced humoral and cellular immunity. PCP-II could be developed as an efficacious adjuvant in human and animal vaccines.

  3. Enhanced humoral and cell-mediated immune responses generated by cationic polymer-coated PLA microspheres with adsorbed HBsAg.

    PubMed

    Chen, Xiaoming; Liu, Yuying; Wang, Lianyan; Liu, Yuan; Zhang, Weifeng; Fan, Bei; Ma, Xiaowei; Yuan, Qipeng; Ma, Guanghui; Su, Zhiguo

    2014-06-01

    Surface-engineered particulate delivery systems for vaccine administration have been widely investigated in experimental and clinical studies. However, little is known about charge-coated microspheres as potential recombinant subunit protein antigen delivery systems in terms of adsorption and related immune responses. In the present study, cationic polymers, including chitosan (CS), chitosan chloride (CSC), and polyethylenimine (PEI), were used to coat PLA microspheres to build positively charged surfaces. Antigen adsorption capacity was enhanced with increased surface charge of coated microspheres. In macrophages, HBsAg adsorbed on the surface of cationic microspheres specifically enhanced antigen uptake and augmented CD86, MHC I, and MHC II expression and IL-1β, IL-6, TNF-α, and IL-12 release. Antigens were more likely to localize independent of lysosomes after phagocytosis in antigen-attached cationic microsphere formulations. After intraperitoneal immunization, cationic microsphere-based vaccine formulations generated a rapid and efficient humoral immune response and cytokine release as compared with aluminum-adsorbed vaccine and free antigens in vivo. Moreover, microspheres coated with cationic polymers with relatively high positive charges and higher antigen adsorption exhibited strong stimulation of the Th1 response. In conclusion, PLA microspheres coated with cationic polymers may be a potential recombinant antigen delivery system to induce strong cell and humoral immune responses.

  4. Prevalence of HBsAg, knowledge, and vaccination practice against viral hepatitis B infection among doctors and nurses in a secondary health care facility in Lagos state, South-western Nigeria

    PubMed Central

    Abiola, Abdul-Hakeem Olatunji; Agunbiade, Adebukola Bola; Badmos, Kabir Bolarinwa; Lesi, Adenike Olufunmilayo; Lawal, Abdulrazzaq Oluwagbemiga; Alli, Quadri Olatunji

    2016-01-01

    Introduction Hepatitis B Virus, a highly infectious blood-borne virus poses a major threat to public health globally due to its high prevalence rate and grave consequence in causing liver cirrhosis and hepatocelullar carcinoma, the third cause of cancer death worldwide. The aim is determine the prevalence of HBsAg, knowledge, and vaccination practices against viral hepatitis B infection among doctors and nurses in a health care facility. Methods Study design was a descriptive cross-sectional study among all the doctors and nurses in the health care facility. Data was collected using pre-tested, structured, self-administered questionnaire and blood samples were taken from respondents and tested using commercial enzyme-linked immunosorbent assay (ELIZA) test kit to determine prevalence of hepatitis B surface antigen after informed consent. Ethical approval was obtained from Health Research and Ethics Committee of the Lagos University Teaching Hospital. Responses of the respondents to the knowledge and vaccination practices against viral hepatitis B infection were scored and graded as poor (<50%), fair (50-74%) and good (≥75%). The study was carried out in January, 2014. Results A total of 134 out of the 143 recruited respondents participated in the study. Prevalence of HBsAg was 1.5%. Among the respondents, 56.7% had good knowledge and 94.8% reported poor practice of vaccination against viral hepatitis B infection. Mean knowledge and vaccination practices scores (%) were 72.54+7.60 and 29.44+14.37 respectively. Only 29% of the respondents did post vaccination testing for anti HBsAg. Conclusion Prevalence of HBsAg was low. Knowledge of viral hepatitis B was fair, and practice of post hepatitis B vaccination testing was poor. It is therefore recommended that the state ministry of health should organise further health education programme, institute compulsory occupational hepatitis B vaccination programme and post vaccination anti-HBS testing to ensure adequate

  5. Effects of 1,2,4,6-tetra-O-galloyl-β-D-glucose from P. emblica on HBsAg and HBeAg secretion in HepG2.2.15 cell culture.

    PubMed

    Xiang, Yang-Fei; Ju, Huai-Qiang; Li, Shen; Zhang, Ying-Jun; Yang, Chong-Ren; Wang, Yi-Fei

    2010-10-01

    A polyphenolic compound, 1,2,4,6-tetra-O-galloyl-β-D-glucose (1246TGG), was isolated from the traditional Chinese medicine Phyllanthus emblica L. (Euphorbiaceae) and assayed for its potential as an anti-hepatitis B virus (HBV) agent. The cytotoxicity of 1246TGG on HepG2.2.15 as well as HepG2 cells was determined by observing cytopathic effects, and the effects of 1246TGG on secretion of HBsAg and HBeAg in HepG2.2.15 cells were assayed by enzyme immunoassay. Results indicates that treatment with 1246TGG (6.25 μg/mL, 3.13 μg/mL), reduced both HBsAg and HBeAg levels in culture supernatant, yet the inhibitory effects tend to decline with the assay time. This study provides a basis for further investigation of the anti-HBV activity and possible mechanism of action of 1246TGG.

  6. HBsAg seroconversion after pegylated interferon alfa 2a rescue in a lamivudine-resistant patient with HBeAg-negative chronic hepatitis B and favourable IL28-B genotype.

    PubMed

    Stanzione, Maria; Stornaiuolo, Gianfranca; Rizzo, Viviana; Pontarelli, Agostina; Gaeta, Giovanni Battista

    2016-06-01

    Hepatitis B virus (HBV) surface antigen (HBsAg) seroconversion to anti-HBs antibody is the best final objective for all available chronic hepatitis B (CHB) treatments. Unfortunately, this goal is rarely achieved with the currently applied therapeutic approaches. Here we describe the case of an anti-HBe-positive CHB patient who was successfully treated with a particular therapeutic schedule. The patient was initially treated with lamivudine (LAM) for nine years. Breakthrough was observed after eight years of LAM therapy. HBV-DNA was 3x10E4 IU/mL and LAM resistance mutations were present. Subcutaneous pegylated interferon (PEG-IFN) alfa 2a, 180 mcg/week, was added to LAM and after 4 weeks LAM was discontinued and PEG-IFN alone was continued up to week 52. HBV-DNA became undetectable at week 4 of therapy; serum HBsAg started to decline from week 4 and became undetectable at week 36, with the subsequent appearance of anti-HBs antibodies. IL28-B was genotyped at the polymorphic site rs12979860 and the CC allele was detected. Rescue therapy with Peg-IFN may be an option for selected patients with resistance to nucleos(t)ide analogues. PMID:27367326

  7. Variability of assay methods for total and free PSA after WHO standardization.

    PubMed

    Foj, L; Filella, X; Alcover, J; Augé, J M; Escudero, J M; Molina, R

    2014-03-01

    The variability of total PSA (tPSA) and free PSA (fPSA) results among commercial assays has been suggested to be decreased by calibration to World Health Organization (WHO) reference materials. To characterize the current situation, it is necessary to know its impact in the critical cutoffs used in clinical practice. In the present study, we tested 167 samples with tPSA concentrations of 0 to 20 μg/L using seven PSA and six fPSA commercial assays, including Access, ARCHITECT i2000, ADVIA Centaur XP, IMMULITE 2000, Elecsys, and Lumipulse G1200, in which we only measured tPSA. tPSA and fPSA were measured in Access using the Hybritech and WHO calibrators. Passing-Bablok analysis was performed for PSA, and percentage of fPSA with the Hybritech-calibrated access comparison assay. For tPSA, relative differences were more than 10 % at 0.2 μg/L for ARCHITECT i2000, and at a critical concentration of 3, 4, and 10 μg/L, the relative difference was exceeded by ADVIA Centaur XP and WHO-calibrated Access. For percent fPSA, at a critical concentration of 10 %, the 10 % relative difference limit was exceeded by IMMULITE 2000 assay. At a critical concentration of 20 and 25 %, ADVIA Centaur XP, ARCHITECT i2000, and IMMULITE 2000 assays exceeded the 10 % relative difference limit. We have shown significant discordances between assays included in this study despite advances in standardization conducted in the last years. Further harmonization efforts are required in order to obtain a complete clinical concordance.

  8. Presence of anti-HBc is associated to high rates of HBV resolved infection and low threshold for Occult HBV Infection in HIV patients with negative HBsAg in Chile.

    PubMed

    Vargas, Jose Ignacio; Jensen, Daniela; Sarmiento, Valeska; Peirano, Felipe; Acuña, Pedro; Fuster, Felipe; Soto, Sabrina; Ahumada, Rodrigo; Huilcaman, Marco; Bruna, Mario; Jensen, Werner; Fuster, Francisco

    2016-04-01

    HBV-HIV coinfection is prevalent. Frequently, anti-HBc is the only serological marker of HBV, which can be indicative of HBV resolved infection, when found together with anti-HBs reactivity; or present as "isolated anti-HBc," related to HBV occult infection with presence of detectable DNA HBV, more prevalent in HIV-positive individuals. Regional data about this condition are scarce. Anti-HBc rapid test has been used as screening, but its performance has not been described in HIV-positive patients. The aim of this study was determine prevalence of anti-HBc in HIV-positive patients, serological pattern of HBV resolved infection and isolated anti-HBc, evaluating presence of HBV occult infection. Assess anti-HBc rapid test compared to ECLIA. Methods included measurement of anti-HBc and anti-HBs in HIV-positive patients with negative HBsAg. Serum HBV DNA quantification and HBV booster vaccination to "isolated anti-HBc" individuals. Detection of anti-HBc by rapid test and ECLIA. In 192 patients, prevalence of anti-HBc was 42.7% (82/192); associated to male gender, drug use, men-sex-men, positive-VDRL, and longer time HIV diagnosis. 34.4% (66/192) had presence of anti-HBs, mean titers of 637 ui/ml. Isolated anti-HBc in 8.3% (16/192), associated to detectable HIV viral load and no-use of HAART; in them, HBV DNA was undetectable, and 60% responded to HBV vaccination booster. Anti-HBc rapid test showed low sensibility (32.9%) compared to ECLIA. These results show that prevalence of anti-HBc in HIV-positive individuals is high, in most cases accompanied with anti-HBs as HBV resolved infection. Low prevalence of "isolated anti-HBc," with undetectable HBV DNA, and most had anamnestic response to HBV vaccination; suggest low possibility of occult HBV infection. Anti-HBc rapid test cannot be recommended as screening method for anti-HBc. PMID:26381185

  9. Presence of anti-HBc is associated to high rates of HBV resolved infection and low threshold for Occult HBV Infection in HIV patients with negative HBsAg in Chile.

    PubMed

    Vargas, Jose Ignacio; Jensen, Daniela; Sarmiento, Valeska; Peirano, Felipe; Acuña, Pedro; Fuster, Felipe; Soto, Sabrina; Ahumada, Rodrigo; Huilcaman, Marco; Bruna, Mario; Jensen, Werner; Fuster, Francisco

    2016-04-01

    HBV-HIV coinfection is prevalent. Frequently, anti-HBc is the only serological marker of HBV, which can be indicative of HBV resolved infection, when found together with anti-HBs reactivity; or present as "isolated anti-HBc," related to HBV occult infection with presence of detectable DNA HBV, more prevalent in HIV-positive individuals. Regional data about this condition are scarce. Anti-HBc rapid test has been used as screening, but its performance has not been described in HIV-positive patients. The aim of this study was determine prevalence of anti-HBc in HIV-positive patients, serological pattern of HBV resolved infection and isolated anti-HBc, evaluating presence of HBV occult infection. Assess anti-HBc rapid test compared to ECLIA. Methods included measurement of anti-HBc and anti-HBs in HIV-positive patients with negative HBsAg. Serum HBV DNA quantification and HBV booster vaccination to "isolated anti-HBc" individuals. Detection of anti-HBc by rapid test and ECLIA. In 192 patients, prevalence of anti-HBc was 42.7% (82/192); associated to male gender, drug use, men-sex-men, positive-VDRL, and longer time HIV diagnosis. 34.4% (66/192) had presence of anti-HBs, mean titers of 637 ui/ml. Isolated anti-HBc in 8.3% (16/192), associated to detectable HIV viral load and no-use of HAART; in them, HBV DNA was undetectable, and 60% responded to HBV vaccination booster. Anti-HBc rapid test showed low sensibility (32.9%) compared to ECLIA. These results show that prevalence of anti-HBc in HIV-positive individuals is high, in most cases accompanied with anti-HBs as HBV resolved infection. Low prevalence of "isolated anti-HBc," with undetectable HBV DNA, and most had anamnestic response to HBV vaccination; suggest low possibility of occult HBV infection. Anti-HBc rapid test cannot be recommended as screening method for anti-HBc.

  10. Performance evaluation of two immunoassays for 25-hydroxyvitamin D

    PubMed Central

    Li, Lusha; Zeng, Qin; Yuan, Jingjing; Xie, Zhongjian

    2016-01-01

    Although immunoassays in measuring 25-hydroxyvitamin D [25(OH)D] have been improved recently, relatively large differences are still seen between results of 25(OH)D measured by immunoassays and by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the present studies, we compared two immunoassays with LC-MS/MS for measuring 25(OH)D concentrations. Concentrations of 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] in serum samples from 59 healthy subjects were measured by two immunoassays including Siemens ADVIA Centaur Vitamin D Total (Centaur) and Roche Elecsys Vitamin D Total (Elecsys) and LC-MS/MS. To determine the cross reactivity of Elecsys and Centaur toward 25(OH)D2, a dosage of 200,000 IU vitamin D2 was given after first sampling. Serum samples were obtained 30 days later and concentrations of 25(OH)D2 and 25(OH)D3 were measured again. The results showed poor agreement between the immunoassays and LC-MS/MS in 25(OH)D2 and 25(OH)D3 measurements. The percentage of 25(OH)D2 cross-reactivity was 45.3% for Centaur and 41.2% for Elecsys and there was no significant difference between Centaur and Elecsys. In conclusion, Centaur and Elecsys perform unsatisfactorily in measuring 25(OH)D levels, especially for 25(OH)D2 cross-reactivity. Therefore, clinicians need to be aware of the underestimation of vitamin D status when using these immunoassays for measuring individuals supplemented with vitamin D2. PMID:27257343

  11. The Centaur Director kicks off Environment and Energy Awareness Week

    NASA Technical Reports Server (NTRS)

    1999-01-01

    At the opening of Environmental and Energy Awareness Week at the Kennedy Space Center Visitor Complex, Center Director Roy Bridges talks to members of the Awareness team inside the United Space Alliance exhibit. The exhibits and displays by KSC and 45th Space Wing organizations detail accomplishments in minimizing environmental impacts and conserving resources. They are on view April 19 - 22 at various sites at KSC, Cape Canaveral Air Station and Patrick Air Force Base.

  12. The Centaur Director kicks off Environment and Energy Awareness Week

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The opening of Environmental and Energy Awareness Week at the Kennedy Space Center Visitor Complex kicked off with a visit by Center Director Roy Bridges and the Awareness team, who presented him with a t-shirt. Exhibits and displays by KSC and 45th Space Wing organizations detail accomplishments in minimizing environmental impacts and conserving resources. They are on view April 19 - 22 at various sites at KSC, Cape Canaveral Air Station and Patrick Air Force Base.

  13. The Centaur Director kicks off Environment and Energy Awareness Week

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Center Director Roy Bridges (right) gets ready to drive an electric car, provided by Florida Power & Light, to the opening of Environmental and Energy Awareness Week at the Kennedy Space Center Visitor Complex. Exhibits and displays by KSC and 45th Space Wing organizations detail accomplishments in minimizing environmental impacts and conserving resources. They are on view April 19 - 22 at various sites at KSC, Cape Canaveral Air Station and Patrick Air Force Base.

  14. Development of lithium-thionyl chloride batteries for Centaur

    NASA Technical Reports Server (NTRS)

    Halpert, Gerald; Frank, Harvey; Lutwack, Ralph

    1987-01-01

    Lithium thionyl chloride (LiSOCl2) primary cells and batteries have received considerable attention over the last several years because of their high theoretical specific energy and energy density. The objective was to develop a 300 wh/kg cell capable of safe operation at C/2 rate and active storage life for 5 to 10 years. This technology would replace other primary cell technologies in NASA applications mainly the silver zinc (AgZn) batteries presently in use. The LiSOCl2 system exceeds the capabilities of the AgZn in terms of specific energy of 300 wh/kg (compared with 100 wh/kg for AgZn), active storage life of 10 to 20 times the 3 to 6 months active storage and has a significantly lower projected cost.

  15. Inconsistent Results of Diagnostic Tools Hamper the Differentiation between Bee and Vespid Venom Allergy

    PubMed Central

    Sturm, Gunter J.; Jin, Chunsheng; Kranzelbinder, Bettina; Hemmer, Wolfgang; Sturm, Eva M.; Griesbacher, Antonia; Heinemann, Akos; Vollmann, Jutta; Altmann, Friedrich; Crailsheim, Karl; Focke, Margarete; Aberer, Werner

    2011-01-01

    Background Double sensitization (DS) to bee and vespid venom is frequently observed in the diagnosis of hymenoptera venom allergy, but clinically relevant DS is rare. Therefore it is sophisticated to choose the relevant venom for specific immunotherapy and overtreatment with both venoms may occur. We aimed to compare currently available routine diagnostic tests as well as experimental tests to identify the most accurate diagnostic tool. Methods 117 patients with a history of a bee or vespid allergy were included in the study. Initially, IgE determination by the ImmunoCAP, by the Immulite, and by the ADVIA Centaur, as well as the intradermal test (IDT) and the basophil activation test (BAT) were performed. In 72 CAP double positive patients, individual IgE patterns were determined by western blot inhibition and component resolved diagnosis (CRD) with rApi m 1, nVes v 1, and nVes v 5. Results Among 117 patients, DS was observed in 63.7% by the Immulite, in 61.5% by the CAP, in 47.9% by the IDT, in 20.5% by the ADVIA, and in 17.1% by the BAT. In CAP double positive patients, western blot inhibition revealed CCD-based DS in 50.8%, and the CRD showed 41.7% of patients with true DS. Generally, agreement between the tests was only fair and inconsistent results were common. Conclusion BAT, CRD, and ADVIA showed a low rate of DS. However, the rate of DS is higher than expected by personal history, indicating that the matter of clinical relevance is still not solved even by novel tests. Furthermore, the lack of agreement between these tests makes it difficult to distinguish between bee and vespid venom allergy. At present, no routinely employed test can be regarded as gold standard to find the clinically relevant sensitization. PMID:21698247

  16. Launch mission summary: Intelsat 5 (F3) Atlas/Centaur-55

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Intelsat 5 (F3) spacecraft, launch vehicle, and mission are described. Information relative to launch windows, flight plan, radar and telemetry coverage, selected trajectory information, and a brief sequence of flight events is provided.

  17. Titan/Centaur D-1T TC-2, Helios A flight data report. [of space missions

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Background data of spacecraft launching and flight are presented. A system analysis of the space vehicles is included, specifically on: (1) electronic equipment, (2) hydraulic equipment, (3) telemetry, (4) propulsion systems, (5) software (computers), and (6) guidance. Spacecraft and launch vehicle configurations are shown and described.

  18. Selective allergy to lobster in a case of primary sensitization to house dust mites.

    PubMed

    Iparraguirre, A; Rodríguez-Pérez, R; Juste, S; Ledesma, A; Moneo, I; Caballero, M L

    2009-01-01

    Allergy to only 1 kind of seafood is uncommon. We report a case of selective allergy to lobster. We studied a 30-year-old man who suffered generalized urticaria, facial erythema, and pharyngeal pruritus after eating lobster. He had a more than 10-year history of mild persistent asthma and sensitization to house dust mites. The study was performed by skin prick test, and prick-prick test, oral food challenge, specific immunoglobulin (Ig) E determinations by CAP (Phadia, Uppsala, Sweden) and ADVIA-Centaur (ALK-Abelló, Madrid, Spain), and IgE-immunoblotting. The patient's serum recognized 2 allergens of around 198 kDa and 2 allergens of around 65 kDa from the lobster extract, allergens of around 15, 90, and 120 kDa from Dermatophagoides pteronyssinus extract, and allergens of around 15 and 65 kDa from Dermatophagoides farinae extract. Serum did not recognize purified shrimp tropomyosin. Immunoblot-inhibition assay results indicated cross-reactivity between lobster and mite allergens. This is the first report of selective allergy to lobster.

  19. Phylogenetic analysis of HDV isolates from HBsAg positive patients in Karachi, Pakistan

    PubMed Central

    2012-01-01

    Background In spite of a high occurrence of Hepatitis Delta in the province of Sindh in Pakistan, no genetic study of Hepatitis Delta virus (HDV) isolates from this region was carried out. The aim of this study is to analyze the genetic proximity within local HDV strains, and relationship with other clades of HDV, using phylogenetic analysis. Results Phylogenetic analysis of nucleotide sequences of the Hepatitis Delta Antigen (HDAg) R0 region obtained in this study, showed considerable diversity among the local strains with a potential subgroup formation within clade I. The multiple sequence alignment of predicted amino acids within clade I showed many uncommon amino acid substitutions within some conserved regions that are crucial for replication and assembly of HDV. Conclusions The studied strains showed a range of genetic diversity within HDV clade I. There is clustering of sequences into more than one group, along with formation of potential subgroup within clade I. Clustering shows the genetic closeness of strains and indicates a common origin of spread of HDV infection. Further phylogeny-based studies may provide more information about subgroup formation within clade I and may be used as an effective tool in checking and/or preventing the spread of hepatitis D virus infection in this region. PMID:22894717

  20. Power System Overview for the Small RPS Centaur Flyby and the Mars Polar Hard Lander NASA COMPASS Studies

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.

    2014-01-01

    The NASA Glenn Research Center (GRC) Radioisotope Power System Program Office (RPSPO) sponsored two studies lead by their mission analysis team. The studies were performed by NASA GRCs Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) team. Typically a complete toplevel design reference mission (DRM) is performed assessing conceptual spacecraft design, launch mass, trajectory, science strategy and sub-system design such as, power, propulsion, structure and thermal.

  1. The development of decision limits for the GH-2000 detection methodology using additional insulin-like growth factor-I and amino-terminal pro-peptide of type III collagen assays.

    PubMed

    Holt, Richard I G; Böhning, Walailuck; Guha, Nishan; Bartlett, Christiaan; Cowan, David A; Giraud, Sylvain; Bassett, E Eryl; Sönksen, Peter H; Böhning, Dankmar

    2015-09-01

    The GH-2000 and GH-2004 projects have developed a method for detecting GH misuse based on measuring insulin-like growth factor-I (IGF-I) and the amino-terminal pro-peptide of type III collagen (P-III-NP). The objectives were to analyze more samples from elite athletes to improve the reliability of the decision limit estimates, to evaluate whether the existing decision limits needed revision, and to validate further non-radioisotopic assays for these markers. The study included 998 male and 931 female elite athletes. Blood samples were collected according to World Anti-Doping Agency (WADA) guidelines at various sporting events including the 2011 International Association of Athletics Federations (IAAF) World Athletics Championships in Daegu, South Korea. IGF-I was measured by the Immunotech A15729 IGF-I IRMA, the Immunodiagnostic Systems iSYS IGF-I assay and a recently developed mass spectrometry (LC-MS/MS) method. P-III-NP was measured by the Cisbio RIA-gnost P-III-P, Orion UniQ™ PIIINP RIA and Siemens ADVIA Centaur P-III-NP assays. The GH-2000 score decision limits were developed using existing statistical techniques. Decision limits were determined using a specificity of 99.99% and an allowance for uncertainty because of the finite sample size. The revised Immunotech IGF-I - Orion P-III-NP assay combination decision limit did not change significantly following the addition of the new samples. The new decision limits are applied to currently available non-radioisotopic assays to measure IGF-I and P-III-NP in elite athletes, which should allow wider flexibility to implement the GH-2000 marker test for GH misuse while providing some resilience against manufacturer withdrawal or change of assays.

  2. The development of decision limits for the GH-2000 detection methodology using additional insulin-like growth factor-I and amino-terminal pro-peptide of type III collagen assays.

    PubMed

    Holt, Richard I G; Böhning, Walailuck; Guha, Nishan; Bartlett, Christiaan; Cowan, David A; Giraud, Sylvain; Bassett, E Eryl; Sönksen, Peter H; Böhning, Dankmar

    2015-09-01

    The GH-2000 and GH-2004 projects have developed a method for detecting GH misuse based on measuring insulin-like growth factor-I (IGF-I) and the amino-terminal pro-peptide of type III collagen (P-III-NP). The objectives were to analyze more samples from elite athletes to improve the reliability of the decision limit estimates, to evaluate whether the existing decision limits needed revision, and to validate further non-radioisotopic assays for these markers. The study included 998 male and 931 female elite athletes. Blood samples were collected according to World Anti-Doping Agency (WADA) guidelines at various sporting events including the 2011 International Association of Athletics Federations (IAAF) World Athletics Championships in Daegu, South Korea. IGF-I was measured by the Immunotech A15729 IGF-I IRMA, the Immunodiagnostic Systems iSYS IGF-I assay and a recently developed mass spectrometry (LC-MS/MS) method. P-III-NP was measured by the Cisbio RIA-gnost P-III-P, Orion UniQ™ PIIINP RIA and Siemens ADVIA Centaur P-III-NP assays. The GH-2000 score decision limits were developed using existing statistical techniques. Decision limits were determined using a specificity of 99.99% and an allowance for uncertainty because of the finite sample size. The revised Immunotech IGF-I - Orion P-III-NP assay combination decision limit did not change significantly following the addition of the new samples. The new decision limits are applied to currently available non-radioisotopic assays to measure IGF-I and P-III-NP in elite athletes, which should allow wider flexibility to implement the GH-2000 marker test for GH misuse while providing some resilience against manufacturer withdrawal or change of assays. PMID:25645199

  3. HBsAg and aflatoxins in sera of rural (Igbo-Ora) and urban (Ibadan) populations in Nigeria.

    PubMed

    Olubuyide, I O; Maxwell, S M; Akinyinka, O O; Hart, C A; Neal, G E; Hendrickse, R G

    1993-12-01

    The purpose of this study was to screen for the presence of hepatitis B surface antigen and aflatoxins in the sera of 100 non-hospitalized individuals from the rural population of Igbo-Ora and 89 non-hospitalized individuals from the urban population of Ibadan, Nigeria. Hitherto, such a study as this has not been undertaken in this environment. The proportions of hepatitis B surface antigen carriage and serum 'pathologic' levels of aflatoxins were high (47-49%, 8.2-9.0% respectively) but varied very little between the two different populations sampled. These findings indicate that determined efforts should be instituted to reduce or eliminate hepatitis B virus infection and aflatoxin contamination of high risk foodstuffs from this environment.

  4. [The management of dialysis patients seropositive for HBsAg, anti-HCV, or anti-HIV antibodies].

    PubMed

    Fabrizi, Fabrizio; Messa, Piergiorgio

    2012-01-01

    Infections by hepatitis B or hepatitis C virus are still common among patients on maintenance dialysis in Western countries. The natural history of HBV and HCV in the dialysis population remains unclear; however, there is good evidence showing an adverse impact of an anti-HCV seropositive status on survival in dialysis patients. A recent meta-analysis of observational studies (n=7, 11,589 unique patients) reported that anti-HCV-positive patients on dialysis had a higher mortality rate than those who were anti-HCV negative (adjusted hazard ratio=1.35, 95% confidence interval, 1.13; 1.59, p<0.001). This was in part attributed to a higher frequency of chronic hepatitis C and its attending complications (cirrhosis and hepatocellular carcinoma). In addition, HCV appeared to have a negative influence on quality of life. Recent clinical guidelines by the KDIGO Study Group have not suggested the isolation of anti-HCV-positive patients on maintenance dialysis. Standard precautions and specific procedures against the transmission of blood-borne agents have been recommended to control HCV infection within dialysis units. Isolation by dialysis machines, staff and rooms has been strongly recommended to control HBV. Vaccination is an important tool against transmission of HBV infection among patients on maintenance dialysis; however, the immune response towards the hepatitis B vaccine in uremic patients remains unsatisfactory. Monotherapy with lamivudine is currently used for dialysis patients with hepatitis B whereas combination antiviral therapy (pegylated interferon plus ribavirin) is the standard of care for hepatitis C in the dialysis population, even if various side effects have been observed.

  5. First Ground-based Infrared Detections Of Volatile Species In The Centaur Comet 29P/Schwassmann-Wachmann 1 At Rh = 6.26 AU

    NASA Astrophysics Data System (ADS)

    Paganini, Lucas; Mumma, M. J.; Boehnhardt, H.; Villanueva, G. L.; DiSanti, M. A.; Bonev, B. P.; Blake, G. A.

    2012-10-01

    We observed comet 29P/Schwassmann-Wachmann 1 (hereafter 29P) in UT 2012 February and May with CRIRES/VLT (in the Atacama desert, Chile) and NIRSPEC/Keck-2 (atop Mauna Kea, Hawaii) when the comet was placed at 6.26 AU from the Sun and 5.50 AU from Earth. We detected five CO emission lines on several nights, confirming the ubiquitous content and release of carbon monoxide from the comet’s nucleus. This is the first multiple line detection of any gaseous species in 29P, at any wavelength, and the first extraction of a rotational temperature based on the intensities of multiple spectral lines. We present the production rate and (remarkably low) rotational temperature for CO, and compare them with results extracted from previous observations at radio wavelengths. Along with CO we pursued detections of other volatiles, namely H2O, C2H6, CH4, HCN and CH3OH. Although their detections are not evident in 29P, we present very sensitive upper limits. These results establish a new record for detections by Infrared Spectroscopy of parent volatiles in comets at relatively large heliocentric distances, previously held by detection of CO in C/1995 O1 (Hale-Bopp) at 4.11 AU (with CSHELL/IRTF, DiSanti et al. 1999) and of CO in C/2006 W3 (Christensen) at 4.03 AU (with CRIRES/VLT, Bonev et al. 2012, in prep.). Until now considered to be a somewhat impossible task with IR ground-based facilities, these discoveries open up new opportunities for targeting volatile species in distant comets at low rotational temperatures. • M. A. DiSanti, M. J. Mumma, N. Dello Russo, K. Magee-Sauer, R. E. Novak, T. W. Rettig, Nature 399, 662-665 (1999) • Acknowledgements: L.P. thanks the NASA Postdoctoral Program. We gratefully acknowledge support from the NASA Astrobiology Institute (PI, Mumma), NSF (PI Bonev), the NASA Planetary Astronomy (PI Villanueva; PI Mumma; PI DiSanti) and Planetary Atmospheres (PI DiSanti, PI Villanueva) programs.

  6. GROUND-BASED INFRARED DETECTIONS OF CO IN THE CENTAUR-COMET 29P/SCHWASSMANN-WACHMANN 1 AT 6.26 AU FROM THE SUN

    SciTech Connect

    Paganini, Lucas; Mumma, Michael J.; DiSanti, Michael A.; Villanueva, Geronimo L.; Bonev, Boncho P.; Boehnhardt, Hermann; Lippi, Manuela; Kaeufl, Hans U.; Blake, Geoffrey A.

    2013-04-01

    We observed Comet 29P/Schwassmann-Wachmann 1 (hereafter, 29P) in 2012 February and May with CRIRES/VLT and NIRSPEC/Keck-II, when the comet was at 6.26 AU from the Sun and about 5.50 AU from Earth. With CRIRES, we detected five CO emission lines on several nights in each epoch, confirming the ubiquitous content and release of carbon monoxide from the nucleus. This is the first simultaneous detection of multiple lines from any (neutral) gaseous species in comet 29P at infrared wavelengths. It is also the first extraction of a rotational temperature based on the intensities of simultaneously measured spectral lines in 29P, and the retrieved rotational temperature is the lowest obtained in our infrared survey to date. We present the retrieved production rates ({approx}3 Multiplication-Sign 10{sup 28} molecules s{sup -1}) and remarkably low ({approx}5 K) rotational temperatures for CO, and compare them with results from previous observations at radio wavelengths. Along with CO, we pursued detections of other volatiles, namely H{sub 2}O, C{sub 2}H{sub 6}, C{sub 2}H{sub 2}, CH{sub 4}, HCN, NH{sub 3}, and CH{sub 3}OH. Although they were not detected, we present sensitive upper limits. These results establish a new record for detections by infrared spectroscopy of parent volatiles in comets at large heliocentric distances. Until now considered to be a somewhat impossible task with IR ground-based facilities, these discoveries demonstrate new opportunities for targeting volatile species in distant comets.

  7. Ground-Based Infrared Detections of CO in the Centaur-comet 29P/Schwassmann-Wachmann 1 at 6.26 AU from the Sun

    NASA Astrophysics Data System (ADS)

    Paganini, Lucas; Mumma, Michael J.; Boehnhardt, Hermann; DiSanti, Michael A.; Villanueva, Geronimo L.; Bonev, Boncho P.; Lippi, Manuela; Käufl, Hans U.; Blake, Geoffrey A.

    2013-04-01

    We observed Comet 29P/Schwassmann-Wachmann 1 (hereafter, 29P) in 2012 February and May with CRIRES/VLT and NIRSPEC/Keck-II, when the comet was at 6.26 AU from the Sun and about 5.50 AU from Earth. With CRIRES, we detected five CO emission lines on several nights in each epoch, confirming the ubiquitous content and release of carbon monoxide from the nucleus. This is the first simultaneous detection of multiple lines from any (neutral) gaseous species in comet 29P at infrared wavelengths. It is also the first extraction of a rotational temperature based on the intensities of simultaneously measured spectral lines in 29P, and the retrieved rotational temperature is the lowest obtained in our infrared survey to date. We present the retrieved production rates (~3 × 1028 molecules s-1) and remarkably low (~5 K) rotational temperatures for CO, and compare them with results from previous observations at radio wavelengths. Along with CO, we pursued detections of other volatiles, namely H2O, C2H6, C2H2, CH4, HCN, NH3, and CH3OH. Although they were not detected, we present sensitive upper limits. These results establish a new record for detections by infrared spectroscopy of parent volatiles in comets at large heliocentric distances. Until now considered to be a somewhat impossible task with IR ground-based facilities, these discoveries demonstrate new opportunities for targeting volatile species in distant comets. Based on observations obtained at the European Southern Observatory at Cerro Paranal, Chile, under programs 088.C-0092 and 289.C-5014; and the Keck Observatory on Mauna Kea, Hawaii, under program C252ANS.

  8. Pegylated Interferon α-2a Triggers NK-Cell Functionality and Specific T-Cell Responses in Patients with Chronic HBV Infection without HBsAg Seroconversion.

    PubMed

    Bruder Costa, Juliana; Dufeu-Duchesne, Tania; Leroy, Vincent; Bertucci, Inga; Bouvier-Alias, Magali; Pouget, Noelle; Brevot-Lutton, Ophelie; Bourliere, Marc; Zoulim, Fabien; Plumas, Joel; Aspord, Caroline

    2016-01-01

    Pegylated interferon α-2a (Peg-IFN-α) represents a therapeutic alternative to the prolonged use of nucleos(t)ide analog (NA) in chronic hepatitis B (CHB) infection. The mechanisms leading to a positive clinical outcome remain unclear. As immune responses are critical for virus control, we investigated the effects of Peg-IFN-α on both innate and adaptive immunity, and related it to the clinical evolution. The phenotypic and functional features of the dendritic cells (DCs), natural killer (NK) cells and HBV-specific CD4/CD8 T cells were analyzed in HBeAg-negative CHB patients treated for 48-weeks with NA alone or together with Peg-IFN-α, before, during and up to 2-years after therapy. Peg-IFN-α induced an early activation of DCs, a potent expansion of the CD56bright NK subset, and enhanced the activation and functionality of the CD56dim NK subset. Peg-IFN-α triggered an increase in the frequencies of Th1- and Th17-oriented HBV-specific CD4/CD8 T cells. Peg-IFN-α reversed the unresponsiveness of patients to a specific stimulation. Most of the parameters returned to baseline after the stop of Peg-IFN-α therapy. Peg-IFN-α impacts both innate and adaptive immunity, overcoming dysfunctional immune responses in CHB patients. These modulations were not associated with seroconversion, which questioned the benefit of the add-on Peg-IFN-α treatment. PMID:27348813

  9. Pegylated Interferon α-2a Triggers NK-Cell Functionality and Specific T-Cell Responses in Patients with Chronic HBV Infection without HBsAg Seroconversion

    PubMed Central

    Bruder Costa, Juliana; Dufeu-Duchesne, Tania; Leroy, Vincent; Bertucci, Inga; Bouvier-Alias, Magali; Pouget, Noelle; Brevot-Lutton, Ophelie; Bourliere, Marc; Zoulim, Fabien

    2016-01-01

    Pegylated interferon α-2a (Peg-IFN-α) represents a therapeutic alternative to the prolonged use of nucleos(t)ide analog (NA) in chronic hepatitis B (CHB) infection. The mechanisms leading to a positive clinical outcome remain unclear. As immune responses are critical for virus control, we investigated the effects of Peg-IFN-α on both innate and adaptive immunity, and related it to the clinical evolution. The phenotypic and functional features of the dendritic cells (DCs), natural killer (NK) cells and HBV-specific CD4/CD8 T cells were analyzed in HBeAg-negative CHB patients treated for 48-weeks with NA alone or together with Peg-IFN-α, before, during and up to 2-years after therapy. Peg-IFN-α induced an early activation of DCs, a potent expansion of the CD56bright NK subset, and enhanced the activation and functionality of the CD56dim NK subset. Peg-IFN-α triggered an increase in the frequencies of Th1- and Th17-oriented HBV-specific CD4/CD8 T cells. Peg-IFN-α reversed the unresponsiveness of patients to a specific stimulation. Most of the parameters returned to baseline after the stop of Peg-IFN-α therapy. Peg-IFN-α impacts both innate and adaptive immunity, overcoming dysfunctional immune responses in CHB patients. These modulations were not associated with seroconversion, which questioned the benefit of the add-on Peg-IFN-α treatment. PMID:27348813

  10. Improved cell mediated immune responses after successful re-vaccination of non-responders to the hepatitis B virus surface antigen (HBsAg) vaccine using the combined hepatitis A and B vaccine.

    PubMed

    Nyström, Jessica; Cardell, Kristina; Björnsdottir, Thora Björg; Fryden, Aril; Hultgren, Catharina; Sällberg, Matti

    2008-11-01

    We successfully re-vaccinated hepatitis B virus (HBV) vaccine non-responders using a double dose of the combined hepatitis A virus (HAV) and HBV vaccine. The hope was to improve priming of hepatitis B surface antigen (HBsAg)-specific cell mediated immune response (CMI) by an increased antigen dose and a theoretical adjuvant-effect from the local presence of a HAV-specific CMI. A few non-responders had a detectable HBsAg-specific CMI before re-vaccination. An in vitro detectable HBsAg-specific CMI was primed equally effective in non-responders (58%) as in first time vaccine recipients (68%). After the third dose a weak, albeit significant, association was observed between the magnitude of HBsAg-specific proliferation and anti-HBs levels. This regimen improves the priming of HBsAg-specific CMIs and antibodies.

  11. A high energy stage for the National Space Transporation System

    NASA Technical Reports Server (NTRS)

    Stofan, A. J.

    1984-01-01

    The Shuttle/Centaur is an expendable hydrogen/oxygen cryogenic upper stage for use with the National Space Transportation System. It is a modification of the existing Atlas/Centaur which was used by NASA since 1966 to launch interplanetary and Earth orbital payloads for numerous organizations. Two configurations of the Shuttle/Centaur are being developed. Vehicle capability includes placing approximately 4500 kg (10,000 lb) in geostationary orbit, and initial applications will be for the interplanetary Galileo and Ulysses Missions in 1986. The Shuttle/Centaur development program is discussed, the configurations and performance are described, and the unique integration and operations requirements related to the Shuttle are indicated. Design changes to the current Atlas/Centaur required for Shuttle operation are described here, and include those related to Orbiter cargo bay dimensions, environment, and safety considerations.

  12. Infectious vaccinia virus recombinants that express hepatitis B virus surface antigen

    NASA Astrophysics Data System (ADS)

    Smith, Geoffrey L.; Mackett, Michael; Moss, Bernard

    1983-04-01

    Potential live vaccines against hepatitis B virus have been produced. The coding sequence for hepatitis B virus surface antigen (HBsAg) has been inserted into the vaccinia virus genome under control of vaccinia virus early promoters. Cells infected with these vaccinia virus recombinants synthesize and excrete HBsAg and vaccinated rabbits rapidly produce antibodies to HBsAg.

  13. Improved Detection of Hepatitis B Virus Surface Antigen by a New Rapid Automated Assay

    PubMed Central

    Weber, Bernard; Bayer, Anja; Kirch, Peter; Schlüter, Volker; Schlieper, Dietmar; Melchior, Walter

    1999-01-01

    The performance of hepatitis B virus (HBV) surface antigen (HBsAg) screening assays is continuously improved in order to reduce the residual risk of transfusion-associated hepatitis B. In a multicenter study, a new automated rapid screening assay, Elecsys HBsAg (Roche Diagnostics), was compared to well-established tests (Auszyme Monoclonal [overnight incubation] version B and IMx HBsAg [Abbott]). Included in the evaluation were 23 seroconversion panels; sera from the acute and chronic phases of infection; dilution series of various HBsAg standards, HBV subtypes, and S gene mutants; and isolated anti-HBV core antigen-positive samples. To challenge the specificity of the new assay, sera from HBsAg-negative blood donors, pregnant women, and dialysis and hospitalized patients and potentially cross-reactive samples were investigated. Elecsys HBsAg showed a higher sensitivity for HBsAg subtypes ad, ay, adw2, adw4, ayw1, ayw2, ayw4, and adr detection in dilution series of different standards or sera than Auszyme Monoclonal version B and/or IMx HBsAg. Acute hepatitis B was detected in 11 to 16 of 23 seroconversion panels between 2 and 16 days earlier with Elecsys HBsAg than with the alternative assays. Elecsys HBsAg and Auszyme Monoclonal version B detected HBsAg surface mutants with equal sensitivity. The sensitivity and specificity of Elecsys HBsAg were 100%. Auszyme Monoclonal version B had a 99.9% specificity, and its sensitivity was 96.6%. IMx HBsAg showed a poorer sensitivity and specificity than the other assays. In conclusion, Elecsys HBsAg permits earlier detection of acute hepatitis B and different HBV subtypes than the alternative assays. By using highly sensitive HBsAg screening assays, low-level HBsAg carriers among isolated anti-HBV core antigen-positive individuals can be detected. PMID:10405414

  14. Antibodies to Hepatitis B Surface Antigen Potentiate the Response of Human T Lymphocyte Clones to the Same Antigen

    NASA Astrophysics Data System (ADS)

    Celis, Esteban; Chang, Tse Wen

    1984-04-01

    Human T-helper lymphocyte clones specific for hepatitis B virus surface antigen (HBsAg) proliferate on stimulation with HBsAg in vitro. Antibodies specific for HBsAg, but no other antibodies, augment this proliferative response. In the presence of antibodies to HBsAg, the maximum response could be achieved at HBsAg concentrations that were 1 percent of those required in the absence of the antibodies. These findings suggest that antigen-specific antibodies exert regulatory controls on T cells that recognize the same antigens.

  15. Hepatitis B surface antigen-specific cell-mediated immune responses in human chronic hepatitis B surface antigen carriers.

    PubMed Central

    Beutner, K R; Tiku, M L; Ogra, P L

    1978-01-01

    The presence of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs), hepatitis B e antigen (HBeAg) and antibody (anti-HBe), the nature of T-cell function, and specific cell-mediated immunity to HBsAg were determined and evaluated serially in groups of subjects with chronic HBsAg carrier states and in seronegative controls. The techniques of in vitro lymphocyte transformation, spontaneous rosette formation, radioimmunoassay, reverse passive hemagglutination, passive hemagglutination, rheophoresis, and liver function tests were employed for these studies. For the lymphocyte transformation assay, multiple concentrations of phytohemagglutinin and purified HBsAg were used as stimulants. Cell-mediated immunity to HBsAg was detectable in 50% of the chronic HBsAg carriers (responders) at one or more concentrations of HBsAg. The remaining carriers (nonresponders) and controls failed to manifest HBsAg-specific lymphocyte transformation activity. The profile of the responders was characterized by elevated serum glutamic pyruvic transaminase levels, the presence of anti-HBe, high HBsAg titers, and the conspicuous absence of HBeAg in the serum. The nonresponders were characterized by normal serum glutamic pyruvic transaminase levels, the presence of HBeAg and anti-HBe, and lower HBsAg titers. These observations demonstrate the presence of specific cell-mediated immunity to HBsAg in chronic HBsAg carriers who manifest biochemical evidence of liver disease. PMID:80380

  16. Development and qualification of a translating nozzle extension system for the RL10A-4 rocket engine

    NASA Astrophysics Data System (ADS)

    Castro, Joaquin H.; Bustamante, Ralph B.

    1993-06-01

    The paper describes the development and qualification of the nozzle extension system for the RL10-4 engines which were used to power the Centaur upper-stage of the AC-105, the first Atlas IIA vehicle, placing an Intelsat K satellite in GEO. Particular attention is given to the technical aspects of the refractory nozzle system development, describing the design trades, fabrication process, and development/qualification testing requirements. Consideration is also given to the integration of the nozzle extension system in the Centaur vehicle. The successful performance of the nozzle extension system in the Centaur vehicle was demonstrated during the maiden flight.

  17. System design of the Pioneer Venus spacecraft. Volume 13: Preliminary development plans

    NASA Technical Reports Server (NTRS)

    Mixon, M. S.

    1973-01-01

    This Pioneer Venus Study final report describes the following baseline configurations: (1) Thor/Delta Spacecraft Baseline is the baseline presented at the midterm review on 26 February 1973, (2) Atlas/Centaur Spacecraft Baseline is the baseline resulting from studies conducted since the midterm, but prior to receipt of the NASA execution phase RFP, and subsequent to decisions to launch both the multiprobe and orbiter missions in 1978 and use the Atlas/Centaur launch vehicle, and (3) Atlas/Centaur Spacecraft Midterm Baseline is the baseline presented at the 26 February 1973 review and is only used in the launch vehicle utilization trade study.

  18. Numerical modeling of on-orbit propellant motion resulting from an impulsive acceleration

    NASA Technical Reports Server (NTRS)

    Aydelott, John C.; Mjolsness, Raymond C.; Torrey, Martin D.; Hochstein, John I.

    1987-01-01

    In-space docking and separation maneuvers of spacecraft that have large fluid mass fractions may cause undesirable spacecraft motion in response to the impulsive-acceleration-induced fluid motion. An example of this potential low gravity fluid management problem arose during the development of the shuttle/Centaur vehicle. Experimentally verified numerical modeling techniques were developed to establish the propellant dynamics, and subsequent vehicle motion, associated with the separation of the Centaur vehicle from the shuttle orbiter cargo bay. Although the shuttle/Centaur development activity was suspended, the numerical modeling techniques are available to predict on-orbit liquid motion resulting from impulsive accelerations for other missions and spacecraft.

  19. Hepatitis B virus markers in anti-HBc only positive individuals.

    PubMed

    Weber, B; Melchior, W; Gehrke, R; Doerr, H W; Berger, A; Rabenau, H

    2001-07-01

    Isolated reactivity to hepatitis B virus (HBV) core antigen (anti-HBc) is observed relatively frequently in immunocompromised individuals, intravenous drug abusers (IVDA), and in the presence of HCV infection. The reason for the lack of HBsAg is not clear. The aim of the present study was to investigate which factors (genetic variability of S gene, low-level HBsAg, and immune complexes may be responsible for the failure of HBsAg detection with commercial HBsAg screening assays. Dilution series of two recombinant HBsAg escape mutants and dilutions of serum samples from chronic HBV carriers with multiple insertions in the a determinant and different HBsAg subtypes were tested with a highly sensitive assay that detects wild-type HBsAg (Elecsys HBsAg, Roche Diagnostics, Penzberg, Germany) and two assays that detect HBV wild-type and escape mutants (Murex HBsAg Version 3, Murex and Enzygnost HBsAg 5.0, Dade Behring, Marburg, Germany). Elecsys HBsAg showed in comparison to Murex HBsAg Version 3 and Enzygnost HBsAg 5.0 a reduced sensitivity for escape mutant detection. On the other hand, the best performance for HBsAg subtype detection was obtained with Elecsys HBsAg. In the second part of the study, a selected panel of isolated anti-HBc reactive (n = 104) serum samples (AxSYM Core) was submitted to testing by Elecsys HBsAg, Murex HBsAg Version 3, Enzygnost HBsAg 5.0, and HBsAg detection after immune complex dissociation (ICD) and anti-HBs determination with two different assays (AxSYM Ausab and Elecsys Anti-HBs). To assess the specificity of anti-HBc test results, all the samples were tested by a second anti-HBc assay (Elecsys Anti-HBc). Quantitative HBV DNA detection was undertaken with a commercially available HBV PCR assay (Amplicor HBV Monitor). HCV infection was present in 65.4% of anti-HBc only reactive individuals. Five AxSYM Core positive samples were negative by Elecsys Anti-HBc. Overall, 15 (14.4%) AxSYM Ausab negative samples gave positive results with Elecsys

  20. Hepatitis B surface antigen clearance in inactive hepatitis B surface antigen carriers treated with peginterferon alfa-2a

    PubMed Central

    Li, Ming-Hui; Xie, Yao; Zhang, Lu; Lu, Yao; Shen, Ge; Wu, Shu-Ling; Chang, Min; Mu, Cai-Qin; Hu, Lei-Ping; Hua, Wen-Hao; Song, Shu-Jing; Zhang, Shu-Feng; Cheng, Jun; Xu, Dao-Zhen

    2016-01-01

    AIM: To examine the association between interferon (IFN) therapy and loss of hepatitis B surface antigen (HBsAg) in inactive HBsAg carriers. METHODS: This was a retrospective cohort study in inactive HBsAg carriers, who were treatment-naive, with a serum HBsAg level < 100 IU/mL and an undetectable hepatitis B virus (HBV) DNA level (< 100 IU/mL). All the 20 treated patients received subcutaneous PEG-IFN alfa-2a 180 μg/wk for 72 wk and were then followed for 24 wk. There were 40 untreated controls matched with 96 wk of observation. Serum HBsAg, HBV DNA, and alanine aminotransferases were monitored every 3 mo in the treatment group and every 3-6 mo in the control group. RESULTS: Thirteen (65.0%) of 20 treated patients achieved HBsAg loss, 12 of whom achieved HBsAg seroconversion. Mean HBsAg level in treated patients decreased to 6.69 ± 13.04 IU/mL after 24 wk of treatment from a baseline level of 26.22 ± 33.00 IU/mL. Serum HBV DNA level remained undetectable (< 100 IU/mL) in all treated patients during the study. HBsAg level of the control group decreased from 25.72 ± 25.58 IU/mL at baseline to 17.11 ± 21.62 IU/mL at week 96 (P = 0.108). In the control group, no patient experienced HBsAg loss/seroconversion, and two (5.0%) developed HBV reactivation. CONCLUSION: IFN treatment results in HBsAg loss and seroconversion in a considerable proportion of inactive HBsAg carriers with low HBsAg concentrations. PMID:27239256

  1. Voyager: Perils of advanced planning, 1960 - 1967

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Contract proposals; phased project planning; budgetary problems; Saturn 1 B-Centaur versus Saturn V; mission guidelines and management assignments; and the origins of the Voyager project are discussed.

  2. Applications of Tethers in Space: Workshop Proceedings, Volume 2

    NASA Technical Reports Server (NTRS)

    Baracat, W. A. (Compiler)

    1986-01-01

    Topics addressed include: tethered orbital transfer vehicle operations, Centaur and Shuttle tether technology; tethered constellations, gravitational effects; Shuttle continuous open wind tunnel; optimal control laws, electrodynamic tether technology; and space station facilities.

  3. Fifth FLTSATCOM to be launched

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Launch of the FLTSATOOM-E, into an elliptical orbit by the Atlas Centaur launch vehicle is announced. The launch and relevant launch operations are described. A chart of the launch sequence for FLTSATCOM-E communication satellite is given.

  4. The Role of Flight Experiments in the Development of Cryogenic Fluid Management Technologies

    NASA Technical Reports Server (NTRS)

    Chato, David J.

    2006-01-01

    This paper reviews the history of cryogenic fluid management technology development and infusion into both the Saturn and Centaur vehicles. Ground testing and analysis proved inadequate to demonstrate full scale performance. As a consequence flight demonstration with a full scale vehicle was required by both the Saturn and Centaur programs to build confidence that problems were addressed. However; the flight vehicles were highly limited on flight instrumentation and the flight demonstration locked-in the design without challenging the function of design elements. Projects reviewed include: the Aerobee Sounding Rocket Cryogenic Fluid Management (CFM) tests which served as a valuable stepping stone to flight demonstration and built confidence in the ability to handle hydrogen in low gravity; the Saturn IVB Fluid Management Qualification flight test; the Atlas Centaur demonstration flights to develop two burn capability; and finally the Titan Centaur two post mission flight tests.

  5. Systems design study of the Pioneer Venus spacecraft. Volume 1. Technical analyses and tradeoffs, sections 5-6 (part 2 of 4)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    System configuration concepts, and tradeoffs are presented for the Atlas/Centaur, and the Thor/Delta probes. Spacecraft system definition, and the probe system definition are discussed along with the mission reliability.

  6. INTELSAT 4. [to be positioned over equator of Pacific Ocean

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A news release on the launching of Intelsat 4 commercial communication satellite is presented. This satellite will be positioned on the equator over the Pacific Ocean. The Atlas-Centaur launch vehicle is considered, along with the launch windows.

  7. Detection of Hepatitis B Virus (HBV) Genotype E Carried—Even in the Presence of High Titers of Anti-HBs Antibodies—by an Argentinean Patient of African Descent Who Had Received Vaccination against HBV

    PubMed Central

    Mathet, Verónica L.; Cuestas, María L.; Ruiz, Vanesa; Minassian, María L.; Rivero, Cintia; Trinks, Julieta; Daleoso, Graciela; León, Liliana M.; Sala, Andrea; Libellara, Beatriz; Corach, Daniel; Oubiña, José R.

    2006-01-01

    Genotype E hepatitis B virus (HBV) was detected in two Argentine sisters exhibiting an African mitochondrial lineage. One of them (who had been vaccinated against HBV) exhibited anti-HBs cocirculating antibodies without HBsAg escape mutants, while her unvaccinated sister showed a D144A HBsAg escape mutant without anti-HBs antibodies. Both sisters carried an unusual L209V substitution within HBsAg. PMID:16954295

  8. Delta hepatitis in Malaysia.

    PubMed

    Sinniah, M; Dimitrakakis, M; Tan, D S

    1986-06-01

    Sera from one hundred and fifty nine Malaysian individuals were screened for the prevalence of delta markers. These included 15 HBsAg positive homosexuals, 16 acute hepatitis B cases, 9 chronic hepatitis B patients, 13 healthy HBsAg carriers and 106 intravenous (i.v.) drug abusers, of whom 27 were positive for HBsAg only and the rest were anti-HBc IgG positive but HBsAg negative. The prevalence of delta markers in the homosexuals was found to be 6.7%, in the HBsAg positive drug abusers 17.8%, in acute hepatitis B cases 12.5%. No evidence of delta infection was detected in healthy HBsAg carriers, chronic hepatitis B cases and HBsAg negative i.v. drug abusers. With reference to i.v. drug abusers, the prevalence of delta markers was higher in Malays (23%) than in Chinese (7%) although the latter had a higher HBsAg carrier rate. Although the HBsAg carrier rate in the homosexuals was high, their delta prevalence rate was low as compared to drug abusers. In Malaysia, as in other non-endemic regions, hepatitis delta virus transmission appeared to occur mainly via the parenteral and sexual routes. This is the first time in Malaysia that a reservoir of delta infection has been demonstrated in certain groups of the population at high risk for hepatitis B. PMID:3787309

  9. Monoclonal antibodies to hepatitis B surface antigen: production and characterization.

    PubMed

    Hlozánek, I; Dostálová, V; Korec, E; Zelený, V; König, J; Nĕmecek, V

    1986-01-01

    Hybridomas secreting anti-HBsAg antibodies were produced by fusion of the mouse myeloma cell line SP2/0 with lymphocytes from mice immunized with purified HBsAg. All clones produced antibodies of the IgG1 idiotype that react with the subtype a determinant of HBsAg. An enzyme immunoassay for detection of HBsAg in human sera using monoclonal antibodies was developed and compared with commercial Sevatest ELISA HBsAg/micro I kit for detection of HBsAg in clinical serum samples. PMID:3527770

  10. Hepatitis B virus reactivation in patients with multiple myeloma receiving bortezomib-containing regimens followed by autologous stem cell transplant.

    PubMed

    Li, Juan; Huang, Beihui; Li, Ying; Zheng, Dong; Zhou, Zhenhai; Liu, Junru

    2015-06-01

    To investigate hepatitis B virus (HBV) reactivation and survival in patients with multiple myeloma (MM) receiving bortezomib-containing regimens, we analyzed 139 patients with MM receiving bortezomib-containing regimens in our hospital. Twenty-seven/139 patients were hepatitis B surface antigen positive (HBsAg+) with nine having DNA levels > 500 IU/mL, including four > 1000 IU/mL. All but five HBsAg+ patients were treated with lamivudine or entecavir before chemotherapy until at least 6 months after chemotherapy or autologous stem cell transplant (ASCT). HBV reactivation occurred in six HBsAg+ patients and two HBsAg- patients, including six who received ASCT. Overall survival and progression-free survival of HBsAg- patients were significantly longer than for HBsAg+ patients (both p < 0.01). From these results, we confirmed that the incidence of HBV reactivation was notable in patients with MM receiving bortezomib-containing regimens, especially those who underwent ASCT. HBsAg+ patients with MM had a poorer prognosis than HBsAg- patients. Prophylactic treatment should be prescribed to all patients with HBsAg+ MM for a minimum duration of 12 months.

  11. Evaluation of turkey erythrocyte hemagglutination assay for the detection of hepatitis B antigen.

    PubMed Central

    Ramirez, R I; Tiku, M L; Ogra, P L

    1975-01-01

    A recently described hemagglutination test for hepatitis B antigen (HBsAg) using turkey erythrocytes coated with horse antibody to HBsAg purified by affinity column chromatography was evaluated on a comparative basis with 100 HBsAg-positive and -negative serum samples. The turkey erythrocyte hemagglutination test (TEHA) was found to be less sensitive than radioimmunoassay (RIA) but gave far better results than counterimmunoelectrophoresis. Quantitative titration of HBsAg in serial dilutions of the samples appeared to be more reliably performed by TEHA than by RIA. TEHA is a simple and sensitive technique for the detection of HBsAg and may offer several practical advantages over RIA. PMID:1236871

  12. Prevalence of hepatitis B surface antigen & its subtypes in high risk group subjects & voluntary blood donors in Bombay.

    PubMed

    Elavia, A J; Banker, D D

    1991-09-01

    HBsAg positive subjects belonging to high risk groups and voluntary blood donors were analysed for prevalence of HBsAg among various groups of subjects for ascertaining the carrier status among the voluntary blood donors, HBsAg subtype distribution, and association of HBsAg with blood groups and caste or religion. The prevalence of HBsAg varied from 2.02 per cent in voluntary blood donors to 58.38 per cent in patients of acute viral hepatitis. 70.5 per cent subjects had subtype 'ay' while 23.9 per cent of the subjects had subtype 'ad'. We also found compound 'ady' subtype in 5.6 per cent of our subjects. HBsAg/adr, a subtype not usually prevalent in India, was found in 30 of the 90 'ad' sera. Co-occurrence of HBsAg and anti-HBs was noted in 9 subjects. Homotypic anti-HBs was found to occur together mainly in voluntary blood donors, while heterotypic anti-HBs was found to occur together mainly multi-transfused patients. There was no significant correlation between HBsAg and blood group antigens and a relatively higher incidence of HBsAg among the Jain community was observed.

  13. Proteomic analysis of hepatitis B surface antigen positive transgenic mouse liver and decrease of cyclophilin A.

    PubMed

    Zhao, Chao; Fang, Cai-Yun; Tian, Xiao-Chen; Wang, Long; Yang, Peng-Yuan; Wen, Yu-Mei

    2007-10-01

    The small, 22-nm spherical particles associated with hepatitis B infection are composed of hepatitis B surface antigen (HBsAg) and usually outnumber the virions by a ratio of 10(2) or 10(3). To study the interactions and pathogenesis between liver cells and the expression of HBsAg, global protein profiles were compared by two dimensional gel-based differential proteomics between the livers of a lineage of HBsAg positive transgenic mice and their HBsAg negative control siblings. A total of 93 proteins were identified in the HBV transgenic mice. Around 45% of these differentially expressed proteins were enzymes associated with metabolism, suggesting that the processing of lipids, carbohydrates and certain amino acids were up- or down-regulated. Among these proteins, cyclophilin A (CypA), the major target for the potent immunosuppressive drug cyclosporin A, was found decreased in HBsAg positive transgenic mouse liver and in a stable cell line expressing HBsAg when compared to their controls. The decrease of intracellular CypA was accompanied by an increased secretion of this protein into the supernatant of HBsAg positive cells. Possible implications of HBsAg expression and the intracellular decrease of CypA are discussed.

  14. Demonstration and quantification of "hyperchromic" erythrocytes by haematological analysers. Application to screening for hereditary and acquired spherocytosis.

    PubMed

    Kutter, Dolphe; Coulon, Nathalie; Stirn, Fernand; Thoma, Martine; Janecki, Jerzy

    2002-01-01

    The double laser beam diffraction of spherized RBC used in the ADVIA 120 haematological analyser allows quantitation of cells aberrant not only by their volume but also by their haemoglobin concentration. The present investigation provides arguments for the identification of hyperchromic RBC as spherocytes, mainly the close relation between % hyperchromic cells and % lysed by the cryohaemolysis test. The percentage of hyperchromic erythrocytes may no longer be considered an instrumental artefact. Without allowing a definite diagnosis of hereditary spherocytosis, an increased percentage of hyperchromic cells indicates the degree of spherocytosis, making it an excellent automated and cost-free screening parameter for inherited and acquired corpuscular haemolysis. PMID:11934218

  15. On the Mass and Origin of Chariklo’s Rings

    NASA Astrophysics Data System (ADS)

    Pan, Margaret; Wu, Yanqin

    2016-04-01

    Observations in 2013 and 2014 of the Centaur 10199 Chariklo and its ring system consistently indicated that the radial width of the inner, more massive ring varies with longitude. That strongly suggests that this ring has a finite eccentricity despite the fast differential precession that Chariklo’s large quadrupole moment should induce. If the inferred apse alignment is maintained by the ring’s self-gravity, as it is for the Uranian rings, we estimate a ring mass of a few times 1016 g and a typical particle size of a few meters. These values imply a collisional spreading time of ∼105 years, which is somewhat shorter than the typical Centaur dynamical lifetime of a few million years and much shorter than the age of the solar system. In light of this time constraint, we evaluate previously suggested ring formation pathways including collisional ejection and satellite disruption. We also investigate in detail a contrasting formation mechanism, the lofting of dust particles off Chariklo’s surface into orbit via outflows of sublimating CO and/or N2 triggered after Chariklo was scattered inward by giant planets. This alternate scenario predicts that rings should be common among 100 km class Centaurs but rare among Kuiper Belt objects and smaller Centaurs. It also predicts that Centaurs should show seasonal variations in cometary activity with activity maxima occurring shortly after equinox.

  16. Hepatitis B and C virus infection as risk factors for hepatocellular carcinoma in Chinese: a case-control study.

    PubMed

    Tsai, J F; Jeng, J E; Ho, M S; Chang, W Y; Lin, Z Y; Tsai, J H

    1994-03-01

    To assess whether hepatitis B and C virus infection were risk factors for hepatocellular carcinoma (HCC), antibody to hepatitis C virus (anti-HCV), hepatitis B surface antigen and e antigen (HBsAg and HBeAg) were tested in 150 HCC patients. Another 150 case-control pairs matched individually by sex and age were also enrolled. Univariate analysis demonstrated that both the anti-HCV and the carrier status of HBsAg and HBeAg were significantly associated with HCC. Multi-variate analysis revealed that both anti-HCV and HBsAg were risk factors for HCC. The population-attributable risk was estimated as 14.2% for anti-HCV alone, 59.4% for HBsAg alone and 8.0% for both anti-HCV and HBsAg in Taiwan. In conclusion, both hepatitis B and C virus infection are independent risk factors for HCC in Chinese in southern Taiwan.

  17. Rapid and quantitative detection of hepatitis B virus

    PubMed Central

    Liu, Yue-Ping; Yao, Chun-Yan

    2015-01-01

    Despite availability of a universal vaccine, hepatitis B virus (HBV) infection has a huge impact on public health worldwide. Accurate and timely diagnosis of HBV infection is needed. Rapid developments have been made in the diagnostic and monitoring methods for HBV infection, including serological and molecular assays. In clinical practice, qualitative hepatitis B surface antigen (HBsAg) testing has long served as a diagnostic marker for individuals infected with HBV. More recently, HBsAg level has been used to predict treatment outcome when determined early during treatment or at baseline. However, identification of HBV DNA positive cases that do not have detectable HBsAg has encouraged the application of molecular tests. Hence, combination of quantitative detection of HBV DNA and HBsAg can be used to discriminate patients during the course of HBV infection and to monitor therapy. This article reviews the most commonly used quantitative methods for HBsAg and HBV DNA. PMID:26576084

  18. Evaluation of the performance of four methods for detection of hepatitis B surface antigen and their application for testing 116,455 specimens.

    PubMed

    Liu, Can; Chen, Tianbin; Lin, Jinpiao; Chen, Huijuan; Chen, Jing; Lin, Sheng; Yang, Bin; Shang, Hongyan; Ou, Qishui

    2014-02-01

    Hepatitis B surface antigen (HBsAg) is a crucial serum marker for the diagnosis of hepatitis B virus (HBV) infection. It is imperative to compare test results from different detection methods based on different principles. Four methods, chemiluminescent microparticle immunoassay (CMIA), electrochemiluminescent immunoassay (ECLIA), enzyme-linked immunosorbent assay (ELISA) and golden immunochromato-graphic assay (GICA) were applied to test the HBsAg level in 250 specimens. According to the EP12-A2 and EP15-A2 documents from Clinical and Laboratory Standards Institute (CLSI), the concentration at which repeated results are 50% positive (C50) of HBsAg detected by CMIA, ECLIA, ELISA and GICA was 0.05, 0.08, 0.15 and 15.0IU/ml, respectively. When the detection concentration of HBsAg was 0.5IU/ml, the imprecision degree of CMIA, ECLIA and ELISA was 8.1%, 5.9% and 14.9% respectively. When detecting high HBsAg level (≥20.0IU/ml) and HBsAg negative specimens, the consistency of the four methods was high, while for the low level (0.05-20.0IU/ml), the consistency was poor (except for the CMIA and ECLIA, P<0.05). When evaluation of the four methods in qualitative diagnosis of HBsAg level in the 116,455 specimens, there was no significant discrepancy among CMIA, CMIA and ECLIA, however, GICA was significantly different from the other 3 methods. Compared with CMIA, the false negative rate of ECLIA, ELISA and GICA was 0.2%, 1.3% and 12.3% respectively. In conclusion, GICA was only suitable for the preliminary screening of HBsAg positive individuals and ELISA can be applied to the qualitative diagnosis of HBsAg. Both CMIA and ECLIA were suitable for the quantitative determination of HBsAg.

  19. La producción de cráteres en el Sistema de Satélites de Saturno

    NASA Astrophysics Data System (ADS)

    Zanardi, M.; Di Sisto, R. P.

    The saturnian satellite system has been observed by the Cassini-Huygens mission, in particular the impact craters on them. These satellites present a diversity of surfaces which could help us to understand about their history. To study the production of craters on these satellites, we develop a theoretical model from previous simulations and we obtain the contribution of Centaur objects to the production of craters. We calculate the number of craters for a given size and the greatest crater produced by Centaur objects. This allowed us to compare our theoretical results with the observations by the Cassini-Huygens and determine the origin of craters as well as constrain the size distribution of Centaurs. FULL TEXT IN SPANISH

  20. Rocket propulsion research at Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Dawson, Virginia P.

    1992-01-01

    A small contingent of engineers at NASA LeRC pioneered the basic research on liquid propellants for rockets shortly after World War 2. Carried on through the 1950s, this work influenced the important early decisions made by Abe Silverstein when he took charge of the Office of Space Flight Programs for NASA. He strongly supported the development of liquid hydrogen as a propulsion fuel in the face of resistance from Wernher von Braun. Members of the LeRC staff played an important role in bringing liquid hydrogen technology to the point of reliability through their management of the Centaur Program. This paper demonstrates how the personality and engineering intuition of Abe Silverstein shaped the Centaur program and left a lasting imprint on the laboratory research tradition. Many of the current leaders of LeRC received their first hands-on engineering experience when they worked on the Centaur program in the 1960s.

  1. Rocket Propulsion Research at Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Dawson, Virginia P.

    1992-01-01

    A small contingent of engineers at NASA Lewis Research Center pioneered in basic research on liquid propellants for rockets shortly after World War II. Carried on through the 1950s, this work influenced the important early decisions made by Abe Silverstein when he took charge of the Office of Space Flight Programs for NASA. He strongly supported the development of liquid hydrogen as a propulsion fuel in the face of resistance from Wernher von Braun. Members of the Lewis staff played an important role in bringing liquid hydrogen technology to the point of reliability through their management of the Centaur Program. This paper demonstrates how the personality and engineering intuition of Abe Silverstein shaped the Centaur program and left a lasting imprint on the laboratory research tradition. Many of the current leaders of Lewis Research Center received their first hands-on engineering experience when they worked on the Centaur program in the 1960s.

  2. Rings from Close Encounters

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    Weve recently discovered narrow sets of rings around two minor planets orbiting in our solar system. How did these rings form? A new study shows that they could be a result of close encounters between the minor planets and giants like Jupiter or Neptune.Unexpected Ring SystemsPositions of the centaurs in our solar system (green). Giant planets (red), Jupiter trojans (grey), scattered disk objects (tan) and Kuiper belt objects (blue) are also shown. [WilyD]Centaurs are minor planets in our solar system that orbit between Jupiter and Neptune. These bodies of which there are roughly 44,000 with diameters larger than 1 km have dynamically unstable orbits that cross paths with those of one or more giant planets.Recent occultation observations of two centaurs, 10199 Chariklo and 2060 Chiron, revealed that these bodies both host narrow ring systems. Besides our four giant planets, Chariklo and Chiron are the only other bodies in the solar system known to have rings. But how did these rings form?Scientists have proposed several models, implicating collisions, disruption of a primordial satellite, or dusty outgassing. But a team of scientists led by Ryuki Hyodo (Paris Institute of Earth Physics, Kobe University) has recently proposed an alternative scenario: what if the rings were formed from partial disruption of the centaur itself, after it crossed just a little too close to a giant planet?Tidal Forces from a GiantHyodo and collaborators first used past studies of centaur orbits to estimate that roughly 10% of centaurs experience close encounters (passing within a distance of ~2x the planetary radius) with a giant planet during their million-year lifetime. The team then performed a series of simulations of close encounters between a giant planet and a differentiated centaur a body in which the rocky material has sunk to form a dense silicate core, surrounded by an icy mantle.Some snapshots of simulation outcomes (click for a closer look!) for different initial states of

  3. Locating the LCROSS Impact Craters

    NASA Technical Reports Server (NTRS)

    Marshall, William; Shirley, Mark; Moratto, Zachary; Colaprete, Anthony; Neumann, Gregory A.; Smith, David E.; Hensley, Scott; Wilson, Barbara; Slade, Martin; Kennedy, Brian; Gurrola, Eric; Harcke, Leif

    2012-01-01

    The Lunar CRater Observations and Sensing Satellite (LCROSS) mission impacted a spent Centaur rocket stage into a permanently shadowed region near the lunar south pole. The Sheperding Spacecraft (SSC) separated approx. 9 hours before impact and performed a small braking maneuver in order to observe the Centaur impact plume, looking for evidence of water and other volatiles, before impacting itself. This paper describes the registration of imagery of the LCROSS impact region from the mid- and near-infrared cameras onboard the SSC, as well as from the Goldstone radar. We compare the Centaur impact features, positively identified in the first two, and with a consistent feature in the third, which are interpreted as a 20 m diameter crater surrounded by a 160 m diameter ejecta region. The images are registered to Lunar Reconnaisance Orbiter (LRO) topographical data which allows determination of the impact location. This location is compared with the impact location derived from ground-based tracking and propagation of the spacecraft's trajectory and with locations derived from two hybrid imagery/trajectory methods. The four methods give a weighted average Centaur impact location of -84.6796 deg, -48.7093 deg, with a 1s uncertainty of 115 m along latitude, and 44 m along longitude, just 146 m from the target impact site. Meanwhile, the trajectory-derived SSC impact location is -84.719 deg, -49.61 deg, with a 1 alpha uncertainty of 3 m along the Earth vector and 75 m orthogonal to that, 766 m from the target location and 2.803 km south-west of the Centaur impact. We also detail the Centaur impact angle and SSC instrument pointing errors. Six high-level LCROSS mission requirements are shown to be met by wide margins. We hope that these results facilitate further analyses of the LCROSS experiment data and follow-up observations of the impact region

  4. Launch vehicles for communications satellites

    NASA Technical Reports Server (NTRS)

    Mahon, J. B.

    1982-01-01

    After giving brief development histories of the Delta and the Atlas Centaur launch vehicles, attention is given to the operational characteristics of the ascent, parking orbit, transfer orbit, and orbital insertion phases of the delivery of a communications satellite to a geostationary orbit by means of a Delta launch vehicle. NASA plans to employ Delta vehicles for as long as they are needed during the transition period to the Space Shuttle. NASA planning for Atlas Centaur includes launches through 1985 for INTELSAT-VA, and through 1986 for FLTSATCOM satellites.

  5. Upper stage in-flight retargeting to enhance geosynchronous satellite operations

    NASA Technical Reports Server (NTRS)

    Lee, Otto W. K.

    1990-01-01

    Real time utilization of propellant reserves that are not needed is available with the implementation of the in-flight retargeting capability for the Centaur Upper Stage. Application to a performance critical, geosynchronous mission is discussed. The operational duration of the satellite may be increased by selectively choosing the appropriate final orbit injection conditions. During ascent Centaur evaluates the amount of propellant excess available and adjusts the final orbit target to consume the excess. Typical satellite mission requirements are introduced to illustrate the mission analysis process to determine the pre-flight nominal target and the in-flight retarget function.

  6. Results of TC-1 boost pump icing tests in the space power facility

    NASA Technical Reports Server (NTRS)

    Gentile, L. C.; Walter, R. J.

    1975-01-01

    A series of tests were conducted in the space power facility to investigate the failure of the Centaur oxidizer boost pump during the Titan/Centaur proof flight February 11, 1974. The three basic objectives of the tests were: (1) demonstrate if an evaporative freezing type failure mechanism could have prevented the pump from operating, (2) determine if steam from the exhaust of one of the attitude control engine could have entered a pump seal cavity and caused the failure, and (3) obtain data on the heating effects of the exhaust plume from a hydrogen peroxide attitude control engine.

  7. Dominance of hepatitis C virus (HCV) is associated with lower quantitative hepatitis B surface antigen and higher serum interferon-γ-induced protein 10 levels in HBV/HCV-coinfected patients.

    PubMed

    Wiegand, S B; Jaroszewicz, J; Potthoff, A; Höner Zu Siederdissen, C; Maasoumy, B; Deterding, K; Manns, M P; Wedemeyer, H; Cornberg, M

    2015-07-01

    Different viral dominance patterns have been documented in coinfection with hepatitis B virus (HBV) and hepatitis C virus (HCV) based on HBV DNA and HCV RNA quantification. In most cases, HCV is dominant and suppresses HBV replication. In vitro studies revealed that there is most probably no direct interference between HBV and HCV replication. We hypothesized that indirect mechanisms mediated by host immune responses might be responsible for the different dominance patterns. In this study we analysed quantitative hepatitis B surface antigen (HBsAg) as a marker for immune control of HBV and interferon γ-induced protein 10 (IP-10) as host marker for the endogenous interferon in 85 patients with HBV/HCV coinfection. Levels of HBsAg were closely associated with viral dominance patterns in 85 HBV/HCV-coinfected patients. HBsAg levels were lowest in patients with HCV dominance, even lower compared with HBV-monoinfected patients undergoing treatment with nucleos(t)ide analogues (NA) but comparable to low replicative HBsAg carriers. An increase in HCV RNA during follow up was associated with HBsAg decline. Patients with HCV dominance had significantly higher serum IP-10 levels compared with HBV-dominant patients or HBV-monoinfected patients treated with NA. Lower HBsAg and higher IP-10 levels in HCV-dominant HBV/HCV-coinfected patients suggest that HCV suppresses HBV DNA replication and also HBsAg production by immune mechanisms.

  8. Circulating Hepatitis B Surface Antigen Particles Carry Hepatocellular microRNAs

    PubMed Central

    Novellino, Luisa; Rossi, Riccardo L.; Bonino, Ferruccio; Cavallone, Daniela; Abrignani, Sergio; Pagani, Massimiliano; Brunetto, Maurizia R.

    2012-01-01

    Hepatitis B virus (HBV) produces high quantities of subviral surface antigen particles (HBsAg) which circulate in the blood outnumbering virions of about 1\\103–6 times. In individuals coinfected with the defective hepatitis Delta virus (HDV) the small HDV-RNA-genome and Delta antigen circulate as ribonucleoprotein complexes within HBsAg subviral particles. We addressed the question whether subviral HBsAg particles may carry in the same way cellular microRNAs (miRNAs) which are released into the bloodstream within different subcellular forms such as exosomes and microvescicles. Circulating HBsAg particles were isolated from sera of 11 HBsAg carriers by selective immunoprecipitation with monoclonal anti-HBs-IgG, total RNA was extracted and human miRNAs were screened by TaqMan real-time quantitative PCR Arrays. Thirty-nine human miRNAs were found to be significantly associated with the immunoprecipitated HBsAg, as determined by both comparative DDCT analysis and non-parametric tests (Mann-Whitney, p<0.05) with respect to controls. Moreover immunoprecipitated HBsAg particles contained Ago2 protein that could be revealed in ELISA only after 0.5% NP40. HBsAg associated miRNAs were liver-specific (most frequent = miR-27a, miR-30b, miR-122, miR-126 and miR-145) as well as immune regulatory (most frequent = miR-106b and miR-223). Computationally predicted target genes of HBsAg-associated miRNAs highlighted molecular pathways dealing with host-pathogen The finding that HBsAg particles carry selective pools of hepatocellular miRNAs opens new avenues of research to disentangle the complex interactions between host and HBV and provides a non invasive tool to study the physiopathology of liver epigenetics. PMID:22470417

  9. Multicenter Evaluation of the Elecsys Hepatitis B Surface Antigen Quantitative Assay ▿

    PubMed Central

    Zacher, B. J.; Moriconi, F.; Bowden, S.; Hammond, R.; Louisirirotchanakul, S.; Phisalprapa, P.; Tanwandee, T.; Wursthorn, K.; Brunetto, M. R.; Wedemeyer, H.; Bonino, F.

    2011-01-01

    The Elecsys hepatitis B surface antigen (HBsAg) II quantitative assay is a new quantitative electrochemiluminescence immunoassay which uses onboard dilution and a simple algorithm to determine HBsAg levels expressed in international units (IU)/ml (standardized against the World Health Organization [WHO] Second International Standard). This study evaluated its performance using routine serum samples from a wide range of HBsAg carriers and patients with chronic hepatitis B (CHB). HBsAg levels were measured in serum samples collected independently by five centers in Europe, Australia, and Asia. Serial dilution analyses were performed to assess the recommended dilution algorithm and determine the assay range free of hook effect. Assay precision was also established. Following assessment of serial dilutions (1:100 to 1:1,000,000) of the 611 samples analyzed, 70.0% and 85.6% of samples tested with analyzers incorporating 1:100 (Elecsys 2010 and cobas e 411) and 1:400 (Modular Analytics E170) onboard dilution, respectively, fell within the linear range of the assay, providing a final result on the first test. No high-dose hook effect was seen up to the maximum HBsAg serum level tested (870,000 IU/ml) using the dilution algorithm. HBsAg levels were reliably determined across all hepatitis B virus (HBV) genotypes, phases of HBV infection, and stages of disease tested. Precision was high across all analyzers (% coefficient of variation [CV], 1.4 to 9.6; HBsAg concentrations, 0.1 to 37,300 IU/ml). The Elecsys HBsAg II quantitative assay accurately and reliably quantifies HBsAg in routine clinical samples. Onboard dilution minimizes retesting and reduces the potential for error. PMID:21880853

  10. Circulating hepatitis B surface antigen particles carry hepatocellular microRNAs.

    PubMed

    Novellino, Luisa; Rossi, Riccardo L; Bonino, Ferruccio; Cavallone, Daniela; Abrignani, Sergio; Pagani, Massimiliano; Brunetto, Maurizia R

    2012-01-01

    Hepatitis B virus (HBV) produces high quantities of subviral surface antigen particles (HBsAg) which circulate in the blood outnumbering virions of about 1\\10(3-6) times. In individuals coinfected with the defective hepatitis Delta virus (HDV) the small HDV-RNA-genome and Delta antigen circulate as ribonucleoprotein complexes within HBsAg subviral particles. We addressed the question whether subviral HBsAg particles may carry in the same way cellular microRNAs (miRNAs) which are released into the bloodstream within different subcellular forms such as exosomes and microvescicles. Circulating HBsAg particles were isolated from sera of 11 HBsAg carriers by selective immunoprecipitation with monoclonal anti-HBs-IgG, total RNA was extracted and human miRNAs were screened by TaqMan real-time quantitative PCR Arrays. Thirty-nine human miRNAs were found to be significantly associated with the immunoprecipitated HBsAg, as determined by both comparative DDCT analysis and non-parametric tests (Mann-Whitney, p<0.05) with respect to controls. Moreover immunoprecipitated HBsAg particles contained Ago2 protein that could be revealed in ELISA only after 0.5% NP40. HBsAg associated miRNAs were liver-specific (most frequent = miR-27a, miR-30b, miR-122, miR-126 and miR-145) as well as immune regulatory (most frequent = miR-106b and miR-223). Computationally predicted target genes of HBsAg-associated miRNAs highlighted molecular pathways dealing with host-pathogen. The finding that HBsAg particles carry selective pools of hepatocellular miRNAs opens new avenues of research to disentangle the complex interactions between host and HBV and provides a non invasive tool to study the physiopathology of liver epigenetics.

  11. Multicenter evaluation of the Elecsys hepatitis B surface antigen quantitative assay.

    PubMed

    Zacher, B J; Moriconi, F; Bowden, S; Hammond, R; Louisirirotchanakul, S; Phisalprapa, P; Tanwandee, T; Wursthorn, K; Brunetto, M R; Wedemeyer, H; Bonino, F

    2011-11-01

    The Elecsys hepatitis B surface antigen (HBsAg) II quantitative assay is a new quantitative electrochemiluminescence immunoassay which uses onboard dilution and a simple algorithm to determine HBsAg levels expressed in international units (IU)/ml (standardized against the World Health Organization [WHO] Second International Standard). This study evaluated its performance using routine serum samples from a wide range of HBsAg carriers and patients with chronic hepatitis B (CHB). HBsAg levels were measured in serum samples collected independently by five centers in Europe, Australia, and Asia. Serial dilution analyses were performed to assess the recommended dilution algorithm and determine the assay range free of hook effect. Assay precision was also established. Following assessment of serial dilutions (1:100 to 1:1,000,000) of the 611 samples analyzed, 70.0% and 85.6% of samples tested with analyzers incorporating 1:100 (Elecsys 2010 and cobas e 411) and 1:400 (Modular Analytics E170) onboard dilution, respectively, fell within the linear range of the assay, providing a final result on the first test. No high-dose hook effect was seen up to the maximum HBsAg serum level tested (870,000 IU/ml) using the dilution algorithm. HBsAg levels were reliably determined across all hepatitis B virus (HBV) genotypes, phases of HBV infection, and stages of disease tested. Precision was high across all analyzers (% coefficient of variation [CV], 1.4 to 9.6; HBsAg concentrations, 0.1 to 37,300 IU/ml). The Elecsys HBsAg II quantitative assay accurately and reliably quantifies HBsAg in routine clinical samples. Onboard dilution minimizes retesting and reduces the potential for error.

  12. Functional analysis of 'a' determinant mutations associated with occult HBV in HIV-positive South Africans.

    PubMed

    Powell, Eleanor A; Boyce, Ceejay L; Gededzha, Maemu P; Selabe, Selokela G; Mphahlele, M Jeffrey; Blackard, Jason T

    2016-07-01

    Occult hepatitis B is defined by the presence of hepatitis B virus (HBV) DNA in the absence of hepatitis B surface antigen (HBsAg). Occult HBV is associated with the development of hepatocellular carcinoma, reactivation during immune suppression, and virus transmission. Viral mutations contribute significantly to the occult HBV phenotype. Mutations in the 'a' determinant of HBsAg are of particular interest, as these mutations are associated with immune escape, vaccine escape and diagnostic failure. We examined the effects of selected occult HBV-associated mutations identified in a population of HIV-positive South Africans on HBsAg production in vitro. Mutations were inserted into two different chronic HBV backbones and transfected into a hepatocyte-derived cell line. HBsAg levels were quantified by enzyme-linked immunosorbent assay (ELISA), while the detectability of mutant HBsAg was determined using an HA-tagged HBsAg expression system. Of the seven mutations analysed, four (S132P, C138Y, N146D and C147Y) resulted in decreased HBsAg expression in one viral background but not in the second viral background. One mutation (N146D) led to a decrease in HBsAg detected as compared to HA-tag, indicating that this mutation compromises the ability of the ELISA to detect HBsAg. The contribution of occult-associated mutations to the HBsAg-negative phenotype of occult HBV cannot be determined adequately by testing the effect of the mutation in a single viral background, and rigorous analysis of these mutations is required.

  13. Occult infection related hepatitis B surface antigen variants showing lowered secretion capacity

    PubMed Central

    Kim, Hong; Lee, Seoung-Ae; Won, You-Sub; Lee, HyunJoo; Kim, Bum-Joon

    2015-01-01

    AIM: To elucidate the molecular mechanisms underlying hepatitis B virus (HBV) occult infection of genotype C. METHODS: A total of 10 types of hepatitis B surface antigen (HBsAg) variants from a Korean occult cohort were used. After a complete HBV genome plasmid mutated such that it does not express HBsAg and plasmid encoding, each HBsAg variant was transiently co-transfected into HuH-7 cells. The secretion capacity and intracellular expression of the HBV virions and HBsAgs in their respective variants were analyzed using real-time quantitative polymerase chain reaction assays and commercial HBsAg enzyme-linked immunosorbent assays, respectively. RESULTS: All variants exhibited lower levels of HBsAg secretion into the medium compared with the wild type. In particular, in eight of the ten variants, very low levels of HBsAg secretion that were similar to the negative control were detected. In contrast, most variants (9/10) exhibited normal virion secretion capacities comparable with, or even higher than, the wild type. This provided new insight into the intrinsic nature of occult HBV infection, which leads to HBsAg sero-negativeness but has horizontal infectivity. Furthermore, most variants generated higher reactive oxidative species production than the wild type. This finding provides potential links between occult HBV infection and liver disease progression. CONCLUSION: The presently obtained data indicate that deficiency in the secretion capacity of HBsAg variants may have a pivotal function in the occult infections of HBV genotype C. PMID:25684944

  14. Functional analysis of 'a' determinant mutations associated with occult HBV in HIV-positive South Africans.

    PubMed

    Powell, Eleanor A; Boyce, Ceejay L; Gededzha, Maemu P; Selabe, Selokela G; Mphahlele, M Jeffrey; Blackard, Jason T

    2016-07-01

    Occult hepatitis B is defined by the presence of hepatitis B virus (HBV) DNA in the absence of hepatitis B surface antigen (HBsAg). Occult HBV is associated with the development of hepatocellular carcinoma, reactivation during immune suppression, and virus transmission. Viral mutations contribute significantly to the occult HBV phenotype. Mutations in the 'a' determinant of HBsAg are of particular interest, as these mutations are associated with immune escape, vaccine escape and diagnostic failure. We examined the effects of selected occult HBV-associated mutations identified in a population of HIV-positive South Africans on HBsAg production in vitro. Mutations were inserted into two different chronic HBV backbones and transfected into a hepatocyte-derived cell line. HBsAg levels were quantified by enzyme-linked immunosorbent assay (ELISA), while the detectability of mutant HBsAg was determined using an HA-tagged HBsAg expression system. Of the seven mutations analysed, four (S132P, C138Y, N146D and C147Y) resulted in decreased HBsAg expression in one viral background but not in the second viral background. One mutation (N146D) led to a decrease in HBsAg detected as compared to HA-tag, indicating that this mutation compromises the ability of the ELISA to detect HBsAg. The contribution of occult-associated mutations to the HBsAg-negative phenotype of occult HBV cannot be determined adequately by testing the effect of the mutation in a single viral background, and rigorous analysis of these mutations is required. PMID:27031988

  15. Impacts of the G145R Mutation on the Structure and Immunogenic Activity of the Hepatitis B Surface Antigen: A Computational Analysis

    PubMed Central

    Rezaee, Reza; Poorebrahim, Mansour; Najafi, Saeideh; Sadeghi, Solmaz; Pourdast, Alieh; Alavian, Seyed Moayed; Alavian, Seyed Ehsan; Poortahmasebi, Vahdat

    2016-01-01

    Background Vaccine-escaped hepatitis B virus (HBV) mutations occur within the “a” determinant area, which is located in the major hydrophilic region (MHR) of the hepatitis B surface antigen (HBsAg) protein. It is now well established that the common G145R mutation is highly capable of escaping from HBsAg immune recognition. However, the impacts of this mutation on the structure and immunogenic activity of HBsAg have been poorly investigated. Objectives The present study analyzed the effects of the G145R mutation on the structure and immunogenic activity of the HBsAg. Materials and Methods Three-dimensional (3D) structure of HBsAg for both the wild-type and G145R mutant were predicted and refined using several web tools. After quantitative evaluations, the effects of the G145R mutation on the secondary and 3D structures of the HBsAg were investigated. In parallel, the immunogenic activity of the wild-type and mutant HBsAg was also analyzed using a ClusPro docking server as well as the IEDB web tool. Further analyses were performed via molecular dynamics (MD) simulations using the GROMACS v5.0.2 simulation package. Results The G145R mutation causes a considerable reduction in the immunogenic activity of the HBsAg through a conformational change in the HBsAg antigenic loops. This mutation inserts a new β-strand in the “a” determinant region of the HBsAg, leading to a reduced binding affinity to its monoclonal antibody, MAb12. The G145R mutation also increased the compactness and stability of the HBsAg by enhancing the rigidity of the “a” determinant. Conclusions These data will be beneficial for designing more advanced antibodies for the recognition of the HBsAg in diagnostics. In addition, the results of this study may assist in the design or development of more effective hepatitis B vaccines. PMID:27642350

  16. Monitoring Performance of Complex Systems

    NASA Technical Reports Server (NTRS)

    Thomas, W. F.

    1985-01-01

    33-page report describes use of computers in automatic on-line monitoring of Centaur rocket prior to launch. Computers analyze measurements and verify events and commands. System uses adaptive software so only real problems are detected and brought to attention of engineers. Software techniques transferable to such industrial uses as batch process control and production line automation.

  17. Second INTELSAT IV-A communications satellite set for launch

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The scheduled launching of INTELSAT 4-A is announced. It is a commercial communications satellite to be launched aboard an Atlas/Centaur Launch Vehicle from the Kennedy Space Center, Fla. The satellite has the capability of carrying approximately 6250 two-way telephone conversations.

  18. Intelsat IV-F5 Launch

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An Atlas-Centaur space vehicle lifted off at 5:53 p.m. EDT, June 13, 1972, from Complex 36B carrying an Intelsat Communications Satellite, (Intelsat IV-F5) into Earth orbit. Visible in the foreground is the lighthouse located at Cape Canaveral Air Force Station.

  19. Observations of Planet Crossing Asteroids

    NASA Technical Reports Server (NTRS)

    Tholen, David J.

    1999-01-01

    This grant funds the investigation of the Solar System's planet crossing asteroid population, principally the near Earth and trans-Neptunian objects, but also the Centaurs. Investigations include colorimetry at both visible and near infrared wavelengths, light curve photometry, astrometry, and a pilot project to find near Earth objects with small aphelion distances, which requires observations at small solar elongations.

  20. MARINER 9 SPACE PROBE UNDERGOES FINAL CHECKS PRIOR TO ENCAPSULATION

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Technicians make final checks of the Mariner I spacecraft prior to its encapsulation. The Mars- bound spacecraft lifted off aboard an Atlas-Centaur rocket from Cape Kennedy at 6:23 p.m. EDT, May 30, 1971. Following a flight of nearly six months, the spacecraft, designated Mariner 9, will enter orbit and transmit data about the Red Planet's surface and atmosphere.

  1. An analytical study of reduced-gravity propellant settling

    NASA Technical Reports Server (NTRS)

    Bradshaw, R. D.; Kramer, J. L.; Masica, W. J.

    1974-01-01

    Full-scale propellant reorientation flow dynamics for the Centaur D-1T fuel tank were analyzed. A computer code using the simplified marker and cell technique was modified to include the capability for a variable-grid mesh configuration. Use of smaller cells near the boundary, near baffles, and in corners provides improved flow resolution. Two drop tower model cases were simulated to verify program validity: one case without baffles, the other with baffles and geometry identical to Centaur D-1T. Flow phenomena using the new code successfully modeled drop tower data. Baffles are a positive factor in the settling flow. Two full-scale Centaur D-1T cases were simulated using parameters based on the Titan/Centaur proof flight. These flow simulations indicated the time to clear the vent area and an indication of time to orient and collect the propellant. The results further indicated the complexity of the reorientation flow and the long time period required for settling.

  2. NASA Lewis Research Center low-gravity fluid management technology program

    NASA Technical Reports Server (NTRS)

    Aydelott, J. C.; Carney, M. J.; Hochstein, J. I.

    1985-01-01

    A history of the Lewis Research Center in space fluid management technology program is presented. Current programs which include numerical modeling of fluid systems, heat exchanger/radiator concept studies, and the design of the Cryogenic Fluid Management Facility are discussed. Recent analytical and experimental activities performed to support the Shuttle/Centaur development activity are highlighted.

  3. Intelsat communications satellite scheduled for launch

    NASA Technical Reports Server (NTRS)

    1983-01-01

    To be placed into a highly elliptical transfer orbit by the Atlas Centaur (AC-61) launch vehicle, the INTELSAT V-F satellite has 12,000 voice circuits and 2 color television channels and incorporates a maritime communication system for ship to shore communications. The stages of the launch vehicle and the launch operations are described. A table shows the launch sequence.

  4. Einstein Observatory (HEAO-2)

    NASA Astrophysics Data System (ADS)

    Bond, P.; Murdin, P.

    2002-04-01

    The second in the series of HIGH ENERGY ASTROPHYSICAL OBSERVATORIES was launched by an Atlas-Centaur rocket on 13 November 1978. Soon after its insertion into a 470 km circular orbit inclined at 23.5° to the equator, HEAO-2 was named the Einstein Observatory, in celebration of the centenary of Albert Einstein's birth....

  5. The cart before the horse: Mariner spacecraft and launch vehicles

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Evolution of unmanned space exploration (Pioneer, Ranger, Surveyor, and Prospector) up to 1960, and the problems in the design and use of the Atlas Centaur launch vehicle were discussed. The Mariner Program was developed from the experience gained from the previous unmanned flights.

  6. Hepatitis virus panel

    MedlinePlus

    Hepatitis A antibody test; Hepatitis B antibody test; Hepatitis C antibody test; Hepatitis D antibody test ... or past infection, or immunity to hepatitis A Hepatitis B tests: Hepatitis B surface antigen (HBsAg), you have ...

  7. Hepatitis B infection among adults in the philippines: A national seroprevalence study

    PubMed Central

    Wong, Stephen N; Ong, Janus P; Labio, Madalinee Eternity D; Cabahug, Oscar T; Daez, Maria Lourdes O; Valdellon, Erlinda V; Sollano Jr, Jose D; Arguillas, Marilyn O

    2013-01-01

    AIM: To determine the prevalence of hepatitis B surface antigen (HBsAg) seropositivity among adult Filipinos. METHODS: Testing for HBsAg was performed on serum samples from persons aged ≥ 20 years old who participated in the National Nutrition and Health Survey (NNHeS) conducted in 2003. Information on age, sex, marital status, educational attainment, employment status, and income were collected. For this study, marital status was classified as never married or otherwise (i.e., married, divorced, separated, widowed); educational attainment was classified as high school graduate or below or at least some tertiary education; and employment status was classified as currently employed or currently unemployed. Annual income was divided into 4 quartiles in Philippine pesos (PhP): Q1, ≤ PhP 53064; Q2, PhP 53065-92192; Q3, PhP 92193-173387; and Q4, ≥ PhP 173388. Prevalence estimates were weighted so that they represented the general population. Social and demographic factors were correlated with HBsAg seropositivity. Multivariate analysis was used to determine independent predictors of HBsAg seropositivity. RESULTS: A total of 2150 randomly selected adults, 20 years and over, out of the 4753 adult participants of NNHeS were tested for HBsAg. The HBsAg seroprevalence was 16.7% (95%CI: 14.3%-19.1%), which corresponded to an estimated 7278968 persons infected with hepatitis B. There was no significant difference between males and females (17.5% vs 16.0%; P = 0.555). This corresponded to an estimated 3721775 men and 3557193 women infected with hepatitis B. The HBsAg seroprevalence peaked at age 20-39 years old, with declining prevalence in the older age groups. The only independent predictor of HBsAg seropositivity was the annual income, with persons in the highest income quartile being less likely to be HBsAg positive (age-adjusted OR = 0.51; 95%CI: 0.30-0.86) compared to subjects in the lowest income quartile. Sex, marital status, educational attainment, and employment

  8. Hepatitis B and hepatitis C virus infections among antiretroviral-naive and -experienced HIV co-infected adults.

    PubMed

    Manyazewal, Tsegahun; Sisay, Zufan; Biadgilign, Sibhatu; Abegaz, Woldaregay Erku

    2014-05-01

    Most HIV positive people have not been tested for viral hepatitis and their treatments have not been optimized for possible co-infections. The aim of this study was to investigate the serological pattern of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among antiretroviral (ARV)-naive and -experienced HIV co-infected adults in Addis Ababa, Ethiopia. A total of 500 frozen HIV positive serum and plasma samples collected from ARV-naive (n = 250) and -experienced (n = 250) adults were randomly selected and screened for HBsAg, anti-HBs, HBeAg and anti-HCV using rapid two-site sandwich immunochromatographic assay. The test was performed at Aklilu Lemma Institute of Pathobiology, Addis Ababa University. Positive specimens for HBsAg and anti-HCV markers were further confirmed using third generation ELISA. Of the 500 specimens tested, 15 (3 %), 58 (11.6 %), 3 (0.6 %), 18 (3.6 %), 3 (0.6 %) and 1 (0.2 %) were positive for HBsAg, anti-HBs, HBeAg, anti-HCV, HBsAg and HBeAg, and HBsAg and anti-HBs markers, respectively. No specimen tested positive for both HBeAg and anti-HBs, and 442 (88.4 %) individuals were non-immune to HBV. Of the 250 ARV-naive individuals, 8 (3.2 %), 33 (13.2 %), 2 (0.8 %), 10 (4 %), 2 (0.8 %), and 1 (0.4 %) were positive for HBsAg, anti-HBs, HBeAg, anti-HCV, HBsAg and HBeAg, and HBsAg and anti-HBs markers, respectively. Of the 250 ARV-experienced individuals, 7 (2.8 %), 25 (10 %), 1 (0.4 %), 8 (3.2 %), 1 (0.4 %), and 0 (0 %) were positive for HBsAg, Anti-HBs, HBeAg, anti-HCV, HBsAg and HBeAg, and HBsAg and anti-HBs markers, respectively. In summary, seroprevalence of HIV/HBV and HIV/HCV co-infections was lower in Addis Ababa, Ethiopia, than in Sub-Saharan Africa and globally. HBV and HCV infections were not significantly different between HIV positive subjects who were or who were not on ARV. This suggests that the two groups have equal chance of being infected with these two viruses; despite

  9. Identifying patients infected with hepatitis B virus in sub-Saharan Africa: potential for misclassification.

    PubMed

    Boyd, Anders; Maylin, Sarah; Moh, Raoul; Gabillard, Delphine; Menan, Hervé; Mahjoub, Nadia; Danel, Christine; Anglaret, Xavier; Eholié, Serge Paul; Girard, Pierre-Marie; Zoulim, Fabien; Delaugerre, Constance; Lacombe, Karine

    2015-11-01

    Most research in sub-Saharan Africa establishes hepatitis B infection via one-time hepatitis B surface antigen (HBsAg) testing. Of 237 HIV-infected patients from two clinical trials testing HBsAg positive (MiniVidas®), 206 (86.9%) had validated serological tests using another assay (Architect). Discrepancies could be due to inactive infection, highlighting the importance of assessing hepatitis B virus infection phase. PMID:26283522

  10. Toward the development of monoclonal antibody-based assays to probe virion-like epitopes in hepatitis B vaccine antigen

    PubMed Central

    Zhu, Yibin; Zhang, Tianying; Zhao, Jinghua; Weng, Zusen; Yuan, Quan; Li, Shaowei; Zhang, Jun; Xia, Ning-Shao; Zhao, Qinjian

    2014-01-01

    Prophylactic vaccines against hepatitis B Virus (HBV) infection were produced in different expression systems under different processing conditions. Since the recombinant HBV surface antigen (HBsAg) in these vaccines is a cysteine-rich protein with 14 cysteines among a total of 226 amino acids, the epitopes are dependent on the formation of intra- and intermolecular disulfide bonds. A panel of 22 monoclonal antibodies (mAbs) were developed and evaluated with respect to their sensitivity to disulfide reduction treatment of recombinant HBsAg. Not surprisingly, different mAbs showed different degree of sensitivity to controlled HBsAg disulfide reduction. With a view to exploring the functionality of anti-HBsAg mAbs to be used in HBsAg quality analysis, in vitro neutralization activity for the mAbs was assessed. One of the mAbs tested, 5F11, which showed high sensitivity to the disulfide integrity in HBsAg, was shown also to be highly effective in neutralizing HBV in vitro. Conversely, 42B6, while exhibiting similar neutralization activity, showed comparable binding HBsAg with or without reduction treatment. Based on these mAb characteristics, a sandwich ELISA with 42B6 being the capture Ab and detection Ab was developed to quantify HBsAg (like a “mass” assay) during antigen bioprocessing or in vaccine products. In parallel, when 5F11 was used as the detection Ab (with the same capture Ab), the assay can be used to probe disulfide-dependent and virion-like epitopes in intermediates or final products of hepatitis B vaccine, serving as a surrogate marker for vaccine efficacy to elicit neutralizing antibodies. This approach enables the comparative epitope specific antigenicity analysis of HBsAg antigen preparations from different sources. PMID:24499806

  11. Hepatitis B virus-like particles access major histocompatibility class I and II antigen presentation pathways in primary dendritic cells.

    PubMed

    Moffat, Jessica M; Cheong, Wan-Shoo; Villadangos, José A; Mintern, Justine D; Netter, Hans J

    2013-04-26

    Virus-like particles (VLPs) represent high density displays of viral proteins that efficiently trigger immunity. VLPs composed of the small hepatitis B virus envelope protein (HBsAgS) are useful vaccine platforms that induce humoral and cellular immune responses. Notably, however, some studies suggest HBsAgS VLPs impair dendritic cell (DC) function. Here we investigated HBsAgS VLP interaction with DC subsets and antigen access to major histocompatibility complex (MHC) class I and II antigen presentation pathways in primary DCs. HBsAgS VLPs impaired plasmacytoid DC (pDC) interferon alpha (IFNα) production in response to CpG in vitro, but did not alter conventional DC (cDC) or pDC phenotype when administered in vivo. To assess cellular immune responses, HBsAgS VLPs were generated containing the ovalbumin (OVA) model epitopes OVA(257-264) and OVA(323-339) to access MHCI and MHCII antigen presentation pathways, respectively; both in vitro and following immunisation in vivo. HBsAgS VLP-OVA(257-264) elicited CTL responses in vivo that were not enhanced by inclusion of an additional MHCII helper epitope. HBsAgS VLP-OVA(257-264) administered in vivo was cross-presented by CD8(+) DCs, but not CD8(-) DCs. Therefore, HBsAgS VLPs can deliver antigen to both MHCI and MHCII antigen presentation pathways in primary DCs and promote cytotoxic and helper T cell priming despite their suppressive effect on pDCs.

  12. Hepatitis B surface antigen prevalence among 12 393 rural women of childbearing age in Hainan Province, China: a cross-sectional study

    PubMed Central

    2013-01-01

    Background Hepatitis B virus (HBV) infection is highly endemic in China and it threats human health seriously. The hepatitis B surface antigen (HBsAg) prevalence among women of childbearing age plays an important role in mother to child transmission of HBV, as 30% ~50% of chronic carriers can be attributed to maternal-infantile transmission. However, there are few studies which have reported on the prevalence of HBsAg among women of childbearing age in China. This study aimed to determine the prevalence of HBsAg and its associated risk factors among rural women of childbearing age in Hainan, which is the highest hepatitis B virus endemic province in China. Methods A cross-sectional, population-based study, which included 12393 rural women aged 15 ~ 49 years, enrolled by a multistage stratified cluster sampling, was carried out in Hainan province, China, from November 2007 to December 2008. Blood samples were obtained from each study participant, and screened for HBsAg. Results The overall HBsAg prevalence of childbearing age women was 9.51%. Risk factors for HBsAg positivity among rural women were: lower education level (OR=1.206), lower family monthly income (OR=1.233), having an HBsAg-positive family member (OR=1.300), without an immunization history (OR=1.243), tattooing (OR=1.190), body piercing (OR=1.293), vaginoscopy history (OR=1.103) and history of induced abortion (OR=1.142). Conclusions There is a high HBsAg seroprevalence rate among rural women of childbearing age in Hainan province. Hence, it is necessary to take preventive measures to reduce the seroprevalence of HBsAg and to control its associated risk factors. PMID:23332007

  13. Hepatitis B virus (HBV) receptors: Deficiency in tumor results in scant HBV infection and overexpression in peritumor leads to higher recurrence risk

    PubMed Central

    Ye, Fei; Fan, Qing-Min; Yu, Guo-Feng; Yu, Dan-Dan; Gao, Lu; Sun, Kai; Han, Zhi-Peng; Li, Rong; Yang, Yang; Zhao, Qiu-Dong; Wu, Meng-Chao; Wang, Hong-Yang; Wei, Li-Xin

    2015-01-01

    Hepatitis B virus (HBV) infection is a risk factor for hepatocarcinogenesis and recurrence. Here, we sought to characterize intratumoral and peritumoral expression of HBsAg and its specific receptors in HBsAg-positive hepatocellular carcinoma (HCC) patients and further examined their correlation with the recurrence-free survival (RFS). HCC tissue and adjacent normal tissue specimens were acquired from HBsAg-positive patients. The presence of HBsAg and receptors, as well as hepatic progenitor cells (HPCs) were detected by tissue microassay and immunohistochemistry. Necroinflammatory activity was evaluated by HE staining. The mean IOD of HBsAg and HBV DNA in the intratumoral tissues was markedly lower than that in the peritumoral tissues (P < 0.001). Pearson correlation analysis further showed a significant correlation between the expression of HBsAg and NTCP (r = 0.461, P < 0.001) or ASGPR (r = 0.506, P < 0.001) in peritumoral tissues. And the peritumoral HBsAg and receptors presented a positive association with necroinflammatory activity (P < 0.05). Inflammation induced by HBV infection presented a positive association with HPCs activation (P < 0.05). Additionally, due to lack of HBV receptors, HPCs was not preferentially infected with HBV, but activated HPCs had a significant correlation with HBsAg expression in peritumoral tissues, and the peritumoral HPCs activation was associated with RFS of HCC patients, therefore, the overexpression of HBsAg and receptors in peritumor were also with higher recurrence risk (P < 0.05). In conclusion, lack of HBV receptors resulted in scant HBV infection in tumor cells, and overexpression of HBsAg and receptors in peritumor was strongly associated with higher recurrence risk in HCC patients. PMID:26515593

  14. Identifying patients infected with hepatitis B virus in sub-Saharan Africa: potential for misclassification.

    PubMed

    Boyd, Anders; Maylin, Sarah; Moh, Raoul; Gabillard, Delphine; Menan, Hervé; Mahjoub, Nadia; Danel, Christine; Anglaret, Xavier; Eholié, Serge Paul; Girard, Pierre-Marie; Zoulim, Fabien; Delaugerre, Constance; Lacombe, Karine

    2015-11-01

    Most research in sub-Saharan Africa establishes hepatitis B infection via one-time hepatitis B surface antigen (HBsAg) testing. Of 237 HIV-infected patients from two clinical trials testing HBsAg positive (MiniVidas®), 206 (86.9%) had validated serological tests using another assay (Architect). Discrepancies could be due to inactive infection, highlighting the importance of assessing hepatitis B virus infection phase.

  15. Frequency of Hepatitis B and C Co-Infection in Chronic Liver Disease Patients in Calabar, Cross River State, Nigeria.

    PubMed

    Kooffreh-Ada, M; Okpokam, D C; Okaormhe, Z A; Nna, V U

    2016-01-01

    Hepatitis B (HBsAg) and C (HCV) virus are becoming a significant causative factors in the aetiology of chronic liver disease (CLD) worldwide. However, the information on the frequency of HBsAg and HCV virus co-infection in CLD is sparsely reported in Nigeria. In this study, we assessed the frequency of HBsAg and HCV co-infection in CLD. One hundred and eleven subjects aged 19 - 76 years, comprising of 76 CLD patients and 35 apparently healthy subjects without CLD were tested for both HBsAg and HCV virus antibodies using ELISA test kits. Out of the 111 subjects recruited for this study, 76 (68.5%) were CLD patients tested positive for HBsAg and 35 (31.5%) tested negative for HBsAg and served as control. Out of the 76 CLD patients that tested positive for HBsAg, 34 (44.7%) of them also tested positive for HCV, thus, having co-infection with HBV. Incidence of co-infection was highest in those aged 36 - 45 years, and greater in males than females. Among the control group, 4 (11.4%) of the subjects (3 males and 1 female) tested positive for HCV, while 31 (88.6%) subjects (20 males and 11 females) tested negative. This work has shown that the co-infection with HBV and HCV among chronic liver disease patients and the incidence of HCV is high in our locality. Also, some of the supposed apparently healthy subjects in this study tested positive for HCV, hence the need for improving the awareness of this virus. It is therefore necessary to give immunization and test for HBsAg and HCV in both rural and urban areas. PMID:27574763

  16. Air sampling for hepatitis B surface antigen in a dental operatory.

    PubMed

    Petersen, N J; Bond, W W; Favero, M S

    1979-09-01

    Forty samples of air with a mean sample volume of 104 liters were collected during the treatment of patients whose blood was positive for HBsAG: no samples contained HBsAG and occult blood. These findings suggest that, if environmentally mediated transmission of hepatitis B occurs in the dental operatory, it is more likely to occur through contact with contaminated surfaces than through the airborne route.

  17. DUKSUP: A Computer Program for High Thrust Launch Vehicle Trajectory Design and Optimization

    NASA Technical Reports Server (NTRS)

    Williams, C. H.; Spurlock, O. F.

    2014-01-01

    From the late 1960's through 1997, the leadership of NASA's Intermediate and Large class unmanned expendable launch vehicle projects resided at the NASA Lewis (now Glenn) Research Center (LeRC). One of LeRC's primary responsibilities --- trajectory design and performance analysis --- was accomplished by an internally-developed analytic three dimensional computer program called DUKSUP. Because of its Calculus of Variations-based optimization routine, this code was generally more capable of finding optimal solutions than its contemporaries. A derivation of optimal control using the Calculus of Variations is summarized including transversality, intermediate, and final conditions. The two point boundary value problem is explained. A brief summary of the code's operation is provided, including iteration via the Newton-Raphson scheme and integration of variational and motion equations via a 4th order Runge-Kutta scheme. Main subroutines are discussed. The history of the LeRC trajectory design efforts in the early 1960's is explained within the context of supporting the Centaur upper stage program. How the code was constructed based on the operation of the Atlas/Centaur launch vehicle, the limits of the computers of that era, the limits of the computer programming languages, and the missions it supported are discussed. The vehicles DUKSUP supported (Atlas/Centaur, Titan/Centaur, and Shuttle/Centaur) are briefly described. The types of missions, including Earth orbital and interplanetary, are described. The roles of flight constraints and their impact on launch operations are detailed (such as jettisoning hardware on heating, Range Safety, ground station tracking, and elliptical parking orbits). The computer main frames on which the code was hosted are described. The applications of the code are detailed, including independent check of contractor analysis, benchmarking, leading edge analysis, and vehicle performance improvement assessments. Several of DUKSUP's many major

  18. DUKSUP: A Computer Program for High Thrust Launch Vehicle Trajectory Design and Optimization

    NASA Technical Reports Server (NTRS)

    Spurlock, O. Frank; Williams, Craig H.

    2015-01-01

    From the late 1960s through 1997, the leadership of NASAs Intermediate and Large class unmanned expendable launch vehicle projects resided at the NASA Lewis (now Glenn) Research Center (LeRC). One of LeRCs primary responsibilities --- trajectory design and performance analysis --- was accomplished by an internally-developed analytic three dimensional computer program called DUKSUP. Because of its Calculus of Variations-based optimization routine, this code was generally more capable of finding optimal solutions than its contemporaries. A derivation of optimal control using the Calculus of Variations is summarized including transversality, intermediate, and final conditions. The two point boundary value problem is explained. A brief summary of the codes operation is provided, including iteration via the Newton-Raphson scheme and integration of variational and motion equations via a 4th order Runge-Kutta scheme. Main subroutines are discussed. The history of the LeRC trajectory design efforts in the early 1960s is explained within the context of supporting the Centaur upper stage program. How the code was constructed based on the operation of the AtlasCentaur launch vehicle, the limits of the computers of that era, the limits of the computer programming languages, and the missions it supported are discussed. The vehicles DUKSUP supported (AtlasCentaur, TitanCentaur, and ShuttleCentaur) are briefly described. The types of missions, including Earth orbital and interplanetary, are described. The roles of flight constraints and their impact on launch operations are detailed (such as jettisoning hardware on heating, Range Safety, ground station tracking, and elliptical parking orbits). The computer main frames on which the code was hosted are described. The applications of the code are detailed, including independent check of contractor analysis, benchmarking, leading edge analysis, and vehicle performance improvement assessments. Several of DUKSUPs many major impacts on

  19. A frameshift mutation in the pre-S region of the human hepatitis B virus genome allows production of surface antigen particles but eliminates binding to polymerized albumin.

    PubMed Central

    Persing, D H; Varmus, H E; Ganem, D

    1985-01-01

    The coding region for the major polypeptide (p24S) of hepatitis B surface antigen (HBsAg) is preceded by an in-phase open reading frame termed pre-S. The coding potential of the pre-S region was examined in mouse L cells transformed with cloned hepatitis B virus DNA. Such cells produce three HBsAg-related polypeptides of Mr 24,000, 27,000, and 35,000 organized into complex particles of 22 nm diameter. These HBsAg particles bind to polymerized human albumin, but not to polyalbumins of several other species. In contrast, cells transformed with hepatitis B virus DNA bearing a frameshift mutation near the 3' end of the pre-S region secrete immunoreactive HBsAg particles containing only the 24,000 and 27,000 Mr species. These mutant particles, which lack the 35,000 Mr species, are unable to bind polymerized human albumin. These studies indicate that the pre-S region encodes the 35,000 Mr species, that this product accounts for the known polyalbumin-binding activity of HBsAg but is not required for assembly and secretion of HBsAg 22-nm particles, and that the major polypeptide of HBsAg is not derived primarily by cleavage of larger precursors encoded by the pre-S region. Images PMID:3858831

  20. Prevalence of hepatitis B surface antigen, hepatitis B e antigen and antibody, and antigen subtypes in atomic bomb survivors

    SciTech Connect

    Neriishi, K.; Kodama, K.; Akiba, S. |

    1995-11-01

    On the basis of previous studies showing an association between hepatitis B surface antigen (HBsAg) positivity and radiation exposure in atomic bomb (A-bomb) survivors, we investigated further the active state of hepatitis B virus (HBV) infection by incorporating tests of hepatitis B e antigen (HBeAg) and hepatitis B e antibody (anti-HBe) and HBsAg subtypes into our biennial health examinations. Among 6548 A-bomb survivors for whom HBsAg was assayed between July 1979 and July 1981, 129 persons were HBsAg positive. HBeAg and anti-HBe were measured in 104 of these persons and subtypes of HBsAg in 98 persons. Among those exposed to radiation (average liver dose 0.58 Sv), the odds ratio of HBsAg positivity tended to increase with radiation dose (P for trend = 0.024). The P values for association between the prevalence of HB e antigen and radiation dose were 0.094 and 0.17, respectively. The HB antigen subtype adr was predominant over other subtypes in both Hiroshima and Nagasaki, but the distribution of subtypes did not seem to differ in relation to radiation dose. These results suggested that A-bomb survivors remain in active state of HBV infection and that the mechanism(s) of seroconversion may be impaired. 29 refs., 6 tabs.

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

    PubMed Central

    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. PMID:24302965

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

    PubMed

    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. PMID:24302965

  3. Epidemiological findings of hepatitis B infection based on 1998 National Health and Nutrition Survey in Korea.

    PubMed Central

    Lee, Duk-Hee; Kim, Jin-Ha; Nam, Jung-Ja; Kim, Hye-Reon; Shin, Hai-Rim

    2002-01-01

    The purpose of this study was to investigate the epidemiological characteristics of hepatitis B virus (HBV) infection in Korea based on the 1998 National Health and Nutrition Survey. Study subjects consisted of 9,771 aged 10 yr or over, who were selected from across Korea using a stratified multistage probability sampling design. The prevalence of hepatitis B surface antigen (HBsAg) was compared by age, sex, residency, household income, education, family history, family size, and frequency of eating out. The prevalence of HBsAg was 5.1% (95% confidence interval (CI): 4.5-5.7) in males and 4.1% (95% CI: 3.6-4.6) in females with a low prevalence in those under 20 yr old. Generally, HBsAg seropositivity by administrative area was similar with the exception of Jeju province. HBsAg seropositivity of Jeju island was approximately three times higher in both men and women, as compared with the national average. HBsAg seropositivity by socioeconomic status unexpectedly showed a very consistent positive association in both gender. Comparing HBsAg seropositivity by the frequency of eating out, in both gender, the more frequent they ate out, the higher it was. Our study suggested that there might be another transmission route of HBV, which is possibly related to diet. PMID:12172038

  4. Seroprevalence of Hepatitis B and C markers at the population level in the municipality of Caxias do Sul, southern Brazil

    PubMed Central

    Menegol, Débora; Spilki, Fernando Rosado

    2013-01-01

    Chronic viral hepatitis are main public health problems worldwide. Data about the seroprevalence to Hepatitis B and C viruses (HBV e HCV) at the population level are scarce on Brazil and especially for the Southern region of the country. The seroprevalence to HBV and HBC antigens was evaluated on a large portion of the population of the municipality of Caxias do Sul (427,858 inhabitants), Brazil. A total of 60,604 individual serum samples collected from 2008 to 2011 were screened for HBV surface antigen (HBsAg) and for antibodies against HBsAg; anti HCV antibodies were measured by ELISA (Enzyme Linked Immunosorbent Assay). Overall, 1.63% of the individuals were positive for HBsAg and 1.43% showed seropositivity to HCV. From the total, 31,749 samples were analyzed for HBsAg and 28,855 for HCV. For HBsAg, 519 samples showed positive (1.63%) while the results for 37 patients (0.12%) remained inconclusive. For the anti-HCV test, 412 individuals (1.43%) showed positive. From the positive samples for HBsAg 216 (50.6%) were from male individuals whereas for anti-HCV the seroprevalence was slightly higher for females 216 (52.4%). The higher prevalence for both hepatitis viruses were found among individuals at the age group of 40 to 59 years and the lower levels of positivity for both HBV and HBC were among children and teenagers. PMID:24688517

  5. The Lumipulse G HBsAg-Quant assay for screening and quantification of the hepatitis B surface antigen.

    PubMed

    Yang, Ruifeng; Song, Guangjun; Guan, Wenli; Wang, Qian; Liu, Yan; Wei, Lai

    2016-02-01

    Qualitative HBsAg assay is used to screen HBV infection for decades. The utility of quantitative assay is also rejuvenated recently. We aimed to evaluate and compare the performance of a novel ultra-sensitive and quantitative assay, the Lumipulse assay, with the Architect and Elecsys assays. As screening methods, specificity was compared using 2043 consecutive clinical routine samples. As quantitative assays, precision and accuracy were assessed. Sera from 112 treatment-naïve chronic hepatitis B patients, four patients undergoing antiviral therapy and one patient with acute infection were tested to compare the correlations. Samples with concurrent HBsAg/anti-HBs were also quantified. The Lumipulse assay precisely quantified ultra-low level of HBsAg (0.004 IU/mL). It identified additional 0.98% (20/2043) clinical samples with trance amount of HBsAg. Three assays displayed excellent linear correlations irrespective of genotypes and S-gene mutations (R(2)>0.95, P<0.0001), while minor quantitative biases existed. The Lumipulse assay did not yield higher HBsAg concentrations in samples with concomitant anti-HBs. Compared with other assays, the Lumipulse assay is sensitive and specific for detecting HBsAg. The interpretation of the extremely low-level results, however, is challenging. Quantitative HBsAg results by different assays are highly correlated, but they should be interpreted interchangeably only after conversion to eliminate the biases.

  6. Correlation between hepatitis B virus surface antigen level and alpha-fetoprotein in patients free of hepatocellular carcinoma or severe hepatitis.

    PubMed

    Akuta, Norio; Suzuki, Fumitaka; Kobayashi, Mariko; Hara, Tasuku; Sezaki, Hitomi; Suzuki, Yoshiyuki; Hosaka, Tetsuya; Kobayashi, Masahiro; Saitoh, Satoshi; Ikeda, Kenji; Kumada, Hiromitsu

    2014-01-01

    Alfa-fetoprotein (AFP) is used as a marker of early hepatocarcinogenesis. However, the impact of hepatitis B virus surface antigen (HBsAg) on this relationship in patients with HBV infection is not clear. The present study evaluated the relation between HBsAg and AFP levels at the initial visit in 1,610 untreated HBV patients, free of hepatocellular carcinoma (HCC) or severe hepatitis. The cumulative rate of HCC was significantly lower in patients with a low AFP level (≤10 µg/L; below the upper limit of normal) than in those with a high AFP level (≥11 µg/L) at the initial visit. In patients with HBsAg levels more than 500 IU/ml, HBsAg levels correlated significantly and negatively with AFP levels, and significantly with platelet count. Multivariate analysis of data of patients with HBsAg more than 500 IU/ml identified HBsAg (<7,000 IU/ml), albumin (<3.9 g/dl), platelet count (<20.0 × 10(4) /mm(3)), gamma-glutamyl transpeptidase (≥50 IU/L), aspartate aminotransferase (≥34 IU/L), HBeAg (positive), and HBV core-related antigen (≥3.0 log U/ml) as determinants of a high AFP. Especially, in patients with HBsAg more than 500 IU/ml and low transaminase levels (below the upper limit of normal), HBsAg was identified as significant determinant of a high AFP. On the other hand, in patients with HBsAg less than 500 IU/ml, multivariate analysis identified albumin, gamma-glutamyl transpeptidase, and HBV core-related antigen as determinants of a high AFP. The results indicated that HBsAg level seems to affect, at least in part, the AFP levels, and that it can be used as a surrogate marker of early hepatocarcinogenesis.

  7. Hepatitis B surface antigen titer is a good indicator of durable viral response after entecavir off-treatment for chronic hepatitis B

    PubMed Central

    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

    2016-01-01

    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 cessation. A

  8. Evaluation of a novel chemiluminescent microplate enzyme immunoassay for hepatitis B surface antigen detection.

    PubMed

    Yang, Lin; Song, Liu-Wei; Fang, Lin-Lin; Wu, Yong; Ge, Sheng-Xiang; Li, Hui; Yuan, Quan; Zhang, Jun; Xia, Ning-Shao

    2016-02-01

    Hepatitis B virus surface antigen (HBsAg) is an important biomarker used in the diagnosis of hepatitis B virus (HBV) infection, but false-negative results are still reported in the detection of HBsAg using commercial assays. In this study, we evaluated the qualitative properties of a novel HBsAg chemiluminescence enzyme immunoassay (CLEIA) assay--WTultra. WHO standard sample dilution series and samples from low-level HBsAg carriers (<1 ng/mL) were used to evaluate the sensitivity of the WTultra assay. Boston Biomedica, Inc. (BBI) hepatitis B seroconversion panels were used to assess the ability of the WTultra assay to detect the window period. In addition, dilution series of 22 serum samples with different genotypes, serotypes and HBsAg mutations were used to assess the WTultra assay, and these were compared with other commercial assays. The lower detection limit of the WTultra assay was 0.012 IU/mL, and it showed a high sensitivity (97.52%, 95% CI, 94.95-99.00) in the detection of 282 low-level HBsAg carriers (<1 ng/mL). In samples with various HBV genotypes, serotypes and HBsAg mutations, the WTultra assay yielded 117 positive results in 132 samples, which was significantly higher than the results with the other four commercial assays (89, 83, 65 and 45, respectively, p<0.01). In the assays of mutant strains, the WTultra assay detected 82 positive results in 90 samples, which was significantly better than the results for the Hepanostika HBsAg Ultra (58 positive) and Architect (55 positive) (p<0.01) assays, which in turn were significantly better than the Murex V.3 (41 positive, p=0.026) and AxSYM V2 (29 positive, p<0.01) assays. However, in the detection of 42 samples of wild-type strains with various genotypes and serotypes, no significant differences were observed among the WTultra (35 positive), Architect (28 positive) and Hepanostika HBsAg Ultra (31 positive) assays. However, the WTultra assay detected significantly more samples than the Murex V.3 (24

  9. Dose-response association between hepatitis B surface antigen levels and liver cancer risk in Chinese men and women

    PubMed Central

    Yang, Yang; Gao, Jing; Li, Hong-Lan; Zheng, Wei; Yang, Gong; Zhang, Wei; Ma, Xiao; Tan, Yu-Ting; Rothman, Nat; Gao, Yu-Tang; Chow, Wong-Ho; Shu, Xiao-Ou; Xiang, Yong-Bing

    2016-01-01

    We aimed at evaluating the risk of liver cancer in different levels of HBsAg among Chinese men and women. We carried out a nested case-control study including 363 cases and 3,511 controls in two population-based cohorts in Shanghai. Plasma samples collected at enrollment were quantified for HBsAg levels using the Architect QT assay. Conditional logistic regression was performed to estimate the odds ratios (ORs) and 95% confidence intervals (95%CIs) for liver cancer, with adjustment for potential confounders. HBsAg was detected in 6.29% of control subjects overall (7.02% in men and 4.98% in women). HBsAg levels were positively associated with liver cancer risk in a dose-response manner (Ptrend<0.001). Such association showed a significant gender disparity. With increasing levels of HBsAg, liver cancer risks rose more steeply in men than in women. In men, the adjusted ORs increased from 7.27 (95%CI: 3.49–15.15) at the lowest detectable level of HBsAg (5–9 IU/ml) to 7.16 (95%CI: 3.21–15.96), 34.30 (95%CI: 16.94–69.44), and 47.33 (95%CI: 23.50–95.34) at the highest level of HBsAg (≥1,000 IU/ml) compared to those negative for HBsAg. The corresponding ORs were much lower for women, from 1.37 (95%CI: 0.25–7.47) to 3.81 (95%CI: 1.09–13.28), 7.36 (95%CI: 2.41–22.46), and 16.86 (95%CI: 7.24–39.27), respectively. HBsAg quantification has potential to distinguish individuals at different risks of liver cancer. Men with the lowest detectable level of HBsAg should still pay attention to their liver cancer risks, but those with a higher level may be given a higher priority in future liver cancer surveillance program. PMID:26990915

  10. Mean Platelet Volume in Mycobacterium tuberculosis Infection

    PubMed Central

    Lee, Min Young; Kim, Young Jin; Lee, Hee Joo; Park, Tae Sung

    2016-01-01

    Introduction. Mean platelet volume (MPV) has been thought as a useful index of platelet activation. It is supposed that MPV is also associated with several inflammatory and infectious diseases. Korea still has a high incidence of tuberculosis (TB). The aim of this study was to investigate MPV as an inflammatory marker in TB patients. Materials and Methods. MPV were determined in 221 patients with TB and 143 individuals for control group. MPV was estimated by an Advia 2120 (Siemens Healthcare Diagnostics, Tarrytown, NY, USA). Results. In the TB patient group, a positive correlation was found between CRP and MPV. Age and MPV had a positive correlation in TB patient group. Conclusions. We conclude that there is a significant relation between MPV and inflammatory conditions. MPV can be an inflammatory marker to determine the disease activity in TB patients. PMID:27419136

  11. Nontraditional applications in clinical pathology.

    PubMed

    Jordan, Holly L; Register, Thomas C; Tripathi, Niraj K; Bolliger, Anne Provencher; Everds, Nancy; Zelmanovic, David; Poitout, Florence; Bounous, Denise I; Wescott, Debra; Ramaiah, Shashi K

    2014-10-01

    Most published reviews of preclinical toxicological clinical pathology focus on the fundamental aspects of hematology, clinical chemistry, coagulation, and urinalysis in routine toxicology animal species, for example, rats, mice, dogs, and nonhuman primates. The objective of this continuing education course was to present and discuss contemporary examples of nonroutine applications of clinical pathology endpoints used in the drug development setting. Area experts discussed bone turnover markers of laboratory animal species, clinical pathology of pregnant and growing laboratory animals, clinical pathology of nonroutine laboratory animal species, and unique applications of the Siemens Advia(®) hematology analyzer. This article is a summary based on a presentation given at the 31st Annual Symposium of the Society of Toxicologic Pathology, during the Continuing Education Course titled "Nontraditional Applications of Clinical Pathology in Drug Discovery and Preclinical Toxicology."

  12. Hematology of healthy Florida manatees (Trichechus manatus)

    USGS Publications Warehouse

    Harvey, J.W.; Harr, K.E.; Murphy, D.; Walsh, M.T.; Nolan, E.C.; Bonde, R.K.; Pate, M.G.; Deutsch, C.J.; Edwards, H.H.; Clapp, W.L.

    2009-01-01

    Background: Hematologic analysis is an important tool in evaluating the general health status of free-ranging manatees and in the diagnosis and monitoring of rehabilitating animals. Objectives: The purpose of this study was to evaluate diagnostically important hematologic analytes in healthy manatees (Trichechus manatus) and to assess variations with respect to location (free ranging vs captive), age class (small calves, large calves, subadults, and adults), and gender. Methods: Blood was collected from 55 free-ranging and 63 captive healthy manatees. Most analytes were measured using a CELL-DYN 3500R; automated reticulocytes were measured with an ADVIA 120. Standard manual methods were used for differential leukocyte counts, reticulocyte and Heinz body counts, and plasma protein and fibrinogen concentrations. Results: Rouleaux, slight polychromasia, stomatocytosis, and low numbers of schistocytes and nucleated RBCs (NRBCs) were seen often in stained blood films. Manual reticulocyte counts were higher than automated reticulocyte counts. Heinz bodies were present in erythrocytes of most manatees. Compared with free-ranging manatees, captive animals had slightly lower MCV, MCH, and eosinophil counts and slightly higher heterophil and NRBC counts, and fibrinogen concentration. Total leukocyte, heterophil, and monocyte counts tended to be lower in adults than in younger animals. Small calves tended to have higher reticulocyte counts and NRBC counts than older animals. Conclusions: Hematologic findings were generally similar between captive and free-ranging manatees. Higher manual reticulocyte counts suggest the ADVIA detects only reticulocytes containing large amounts of RNA. Higher reticulocyte and NRBC counts in young calves probably reflect an increased rate of erythropoiesis compared with older animals. ?? 2009 American Society for Veterinary Clinical Pathology.

  13. Within-subject haemoglobin variation in elite athletes: a longitudinal investigation of 13 887 haemoglobin concentration readings.

    PubMed

    Lobigs, Louisa M; Knight, Emma J; Schumacher, Yorck Olaf; Gore, Christopher J

    2016-02-01

    The Athlete Biological Passport (ABP) estimates individualized reference ranges for key blood markers, such as haemoglobin concentration ([Hb]), using predetermined population mean, between- and within-subject variances. Here, we aim to reassess previously published estimates for within-subject [Hb] variance and determine whether sex-, analyzer-, sport-, or season-specific values are required. Our reference population contains 7723 male (mean ± SD, 22.3 ± 4.6 years of age) and 6164 female (21.6 ± 4.3) athlete observations from 49 sports. [Hb] was calculated using one of three cytometers; Bayer-H3 (1997-1999, n = 4554), ADVIA-120 (1999-2010, n = 8636) and Sysmex XT-2000i (2010-2012, n = 697). The final model was a linear mixed model for [Hb] with analyzer (H3, ADVIA, Sysmex), sex (male, female), sport (power-endurance, endurance, skill, team, disabled and non-athletes), season (summer, winter), and the interaction between sex and sport as fixed effects and athlete as a random effect. The model included an exponential correlation structure to allow for within-subject autocorrelation, and allowed different within-subject variances for each sport. Within-subject [Hb] variance (g(2) /L(2) ) was significantly less for power endurance (35.09, 95% CI 33.50 to 36.76), disabled (25.82, 95% CI 21.71 to 35.28) and non-athletes (34.30, 95% CI 28.53 to 35.87) than for endurance (40.35, 95% CI 39.62 to 47.22) and team sports (38.70, 95% CI 37.68 to 39.76) athletes. No new evidence was found to justify adjusting the current within-subject [Hb] variance estimate.

  14. Expression of the hepatitis B virus surface antigen in Drosophila S2 cells

    PubMed Central

    Santos, Alexandra S.; Spina, Ângela; Pereira, Carlos A.

    2008-01-01

    Drosophila melanogaster S2 cells were transfected with a plasmid vector (pAcHBsAgHy) containing the S gene, coding for the hepatitis B virus surface antigen (HBsAg), under control of the constitutive drosophila actin promoter (pAc), and the hygromycin B (Hy) selection gene. The vector was introduced into Schneider 2 (S2) Drosophila cells by DNA transfection and a cell population (S2AcHBsAgHy) was selected by its resistance to hygromycin B. The pAcHBsAgHy vector integrated in transfected S2 cell genome and approximately 1,000 copies per cell were found in a higher HBsAg producer cell subpopulation. The HBsAg production varied in different subpopulations, but did not when a given subpopulation was cultivated in different culture flasks. Higher HBsAg expression was found in S2AcHBsAgHy cells cultivated in Insect Xpress medium (13.5 μg/1E7 cells) and SFX medium (7 μg/1E7 cells) in comparison to SF900II medium (0.6 μg/1E7 cells). An increase of HBsAg was observed in culture maintained under hygromycin selection pressure. Data presented in the paper show that S2AcHBsAgHy cells produce efficiently the HBsAg which is mainly found in the cell supernatant, suggesting that HBsAg is secreted from the cells. The data also show that our approach using the Drosophila expression system is suitable for the preparation of other viral protein preparation. PMID:19003172

  15. Markers of hepatitis B virus infection in asymptomatic drug abusers in Malaysia.

    PubMed

    Mangalam, S; Tan, D S; Vijayamalar, B; Collett, D; Fang, R

    1986-06-01

    Sera from 200 Malaysian male drug abusers were tested for markers of Hepatitis B virus (HBV) infection, viz. HBsAg, HBeAg, anti-HBs and anti-HBc using commercially available enzyme immunoassay (EIA) kits supplied by Abbot Laboratories, Chicago. Of these, 103 (51.5%) were positive for at least one HBV marker, 11 (5.5%) were positive for HBsAg; 4 (2%) for HBeAg, 74 (37%) for anti-HBs and 85 (42.5%) for anti-HBc. The HBsAg carrier rate was roughly the same as the carrier rate in the general population of Malaysia. The majority of drug abusers (95%) have had subclinical, asymptomatic HBV infection. Racially the Malay drug abusers had the highest exposure rate (54.2%). The HBsAg carrier rate was highest in the Chinese drug abusers (15.3%) and lowest in the Indians (0%). The mean age for the HBsAg carriers was found to be 26 years with a mean duration of drug abuse of 72 months. The Malaysian Anti-Narcotics Task Force of the National Security Council reported in the Malay Mail (July 13, 1985) that there were about 106,000 identified drug abusers in Malaysia and that 63% of these were in the 20-29 age groups. It appears from our study that this age group also coincides with the period of high HBsAg carrier rate. Age wise, those less than 21 years old had the highest HBsAg (11%) and HBeAg (5.6%) prevalence rates indicating high infectivity. After the age of 30 years, nearly 50% of the drug abusers appear to be immune with the HBe prevalence of 0%.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3787308

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

    PubMed

    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). PMID:27439498

  17. Genome-free hepatitis B virion levels in patient sera as a potential marker to monitor response to antiviral therapy.

    PubMed

    Luckenbaugh, L; Kitrinos, K M; Delaney, W E; Hu, J

    2015-06-01

    Complete virions of hepatitis B virus (HBV) contain a DNA genome that is enclosed in a capsid composed of the HBV core antigen (HBcAg), which is in turn surrounded by a lipid envelope studded with viral surface antigens (HBsAg). In addition, HBV-infected cells release subviral particles composed of HBsAg only (HBsAg 'spheres' and 'filaments') or HBsAg enveloping HBcAg but devoid of viral DNA ('empty virions'). The hepatitis B e antigen (HBeAg), a soluble antigen related to HBcAg, is also secreted in some HBV-infected patients. The goals of this study were to explore the levels of empty virions in HBV-infected patients before and during therapy with the nucleotide analog tenofovir disoproxil fumarate (TDF) that inhibits HBV DNA synthesis and the relationships of empty virions to complete virions, HBsAg and HBeAg. HBV DNA, HBcAg and HBsAg levels were determined in serum samples from 21 patients chronically infected with HBV and enrolled in clinical TDF studies. Serum levels of empty virions were found to exceed levels of DNA-containing virions, often by ≥ 100-fold. Levels of both empty and complete virions varied and were related to the HBeAg status. When HBV DNA replication was suppressed by TDF, empty virion levels remained unchanged in most but were decreased (to the limit of detection) in some patients who also experienced significant decrease or loss of serum HBsAg. In conclusion, empty virions are present in the serum of chronic hepatitis B patients at high levels and may be useful in monitoring response to antiviral therapy.

  18. Hepatitis B Surface Antigen Loss and Hepatocellular Carcinoma Development in Patients With Dual Hepatitis B and C Infection.

    PubMed

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

    2016-03-01

    Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are 2 major causes of chronic viral hepatitis. It is still unclear how HCV coinfection affects HBV replication and clinical outcomes in HBV/HCV coinfected patients.We conducted a longitudinal study, which enrolled 111 patients with HBV/HCV coinfection and 111 propensity score-matched controls with HBV monoinfection. Both groups had comparable baseline age, sex, fibrosis stage, levels of HBV DNA, and HBV surface antigen (HBsAg). The HCV coinfection and other host/viral factors were correlated with various outcomes, including HBsAg loss and cirrhosis/hepatocellular carcinoma (HCC) development.After a 10-year follow-up, we found that HCV coinfection itself was not associated with HBsAg loss. However, coinfected patients with alanine aminotransferase (ALT) level >80 U/L had a higher chance of HBsAg loss than those with ALT level ≤80 U/L [hazard ratio (95% confidence interval): 4.41 (1.75-11.15)] or matched controls with HBV monoinfection [hazard ratio (95% confidence interval): 3.40 (1.54-7.50)]. Besides, both HCV coinfection and higher ALT levels were associated with higher HCC risks and the HCC risks remained even after HBsAg loss in HBV/HCV con-infected patient.HCV coinfection is not associated with HBsAg loss. A higher ALT level is a major determinant of HBsAg loss in patients with HBV/HCV coinfection. Both HCV coinfection and a higher ALT level were independent risk factors of HCC.

  19. Purification of hepatitis B surface antigen virus-like particles from recombinant Pichia pastoris and in vivo analysis of their immunogenic properties.

    PubMed

    Gurramkonda, Chandrasekhar; Zahid, Maria; Nemani, Satish Kumar; Adnan, Ahmad; Gudi, Satheesh Kumar; Khanna, Navin; Ebensen, Thomas; Lünsdorf, Heinrich; Guzmán, Carlos A; Rinas, Ursula

    2013-12-01

    Following earlier studies on high-level intracellular production of hepatitis B surface antigen (HBsAg) using recombinant Pichia pastoris, we present here in detail an enhanced method for the purification of recombinant HBsAg virus-like particles (VLPs). We have screened various detergents for their ability to promote the solubilization of recombinant intracellular HBsAg. In addition, we have analyzed the effect of cell disruption and extraction regarding their impact on the release of HBsAg. Our results show that introduction of the mild nonionic detergent Tween 20 in the initial process of cell lysis at ∼600bars by high pressure homogenization leads to the best results. The subsequent purification steps involved polyethylene glycol precipitation of host cell contaminants, hydrophobic adsorption of HBsAg to colloidal silica followed by ion-exchange chromatography and either isopycnic density ultracentrifugation or size exclusion chromatography for the recovery of the VLPs. After final KSCN treatment and dialysis, a total yield of ∼3% with a purity of >99% was reached. The pure protein was characterized by electron microscopy, showing the presence of uniform VLPs which are the pre-requisite for immunogenicity. The intramuscular co-administration of HBsAg VLPs, with either alum or a PEGylated-derivative of the toll-like receptor 2/6 agonist MALP-2, to mice resulted in the elicitation of significantly higher HBsAg-specific IgG titers as well as a stronger cellular immune response compared to mice vaccinated with a gold standard vaccine (Engerix™). These results show that P. pastoris derived HBsAg VLPs exhibit a high potential as a superior biosimilar vaccine against hepatitis B.

  20. Genome-free hepatitis B virion levels in patient sera as a potential marker to monitor response to antiviral therapy.

    PubMed

    Luckenbaugh, L; Kitrinos, K M; Delaney, W E; Hu, J

    2015-06-01

    Complete virions of hepatitis B virus (HBV) contain a DNA genome that is enclosed in a capsid composed of the HBV core antigen (HBcAg), which is in turn surrounded by a lipid envelope studded with viral surface antigens (HBsAg). In addition, HBV-infected cells release subviral particles composed of HBsAg only (HBsAg 'spheres' and 'filaments') or HBsAg enveloping HBcAg but devoid of viral DNA ('empty virions'). The hepatitis B e antigen (HBeAg), a soluble antigen related to HBcAg, is also secreted in some HBV-infected patients. The goals of this study were to explore the levels of empty virions in HBV-infected patients before and during therapy with the nucleotide analog tenofovir disoproxil fumarate (TDF) that inhibits HBV DNA synthesis and the relationships of empty virions to complete virions, HBsAg and HBeAg. HBV DNA, HBcAg and HBsAg levels were determined in serum samples from 21 patients chronically infected with HBV and enrolled in clinical TDF studies. Serum levels of empty virions were found to exceed levels of DNA-containing virions, often by ≥ 100-fold. Levels of both empty and complete virions varied and were related to the HBeAg status. When HBV DNA replication was suppressed by TDF, empty virion levels remained unchanged in most but were decreased (to the limit of detection) in some patients who also experienced significant decrease or loss of serum HBsAg. In conclusion, empty virions are present in the serum of chronic hepatitis B patients at high levels and may be useful in monitoring response to antiviral therapy. PMID:25395045

  1. Investigating the impact of hepatitis B virus surface gene polymorphism on antigenicity using ex vivo phenotyping.

    PubMed

    Ijaz, Samreen; Szypulska, Renata; Andrews, Nick; Tedder, Richard S

    2012-11-01

    The hepatitis B virus (HBV) surface antigen (HBsAg) is a complex protein, and understanding accurately the impact of amino acid changes on the antigenicity of the immunodominant a determinant must take this complexity into consideration. Epitope mapping with four mAbs was used to phenotype HBsAg directly from patients' sera to investigate the effect of mutations in their native genetic backbone. The expected mAb reactivity was established initially for samples harbouring 'wild-type' HBsAg sequences across genotypes A-E. The alteration of HBsAg antigenicity, defined by mAb epitope loss, was demonstrated in a number of samples with sequence-inferred amino acid changes. Individual mutations within the mapped epitopes to which the mAbs were directed usually affected their binding. However, the loss of more than one epitope was observed as the number of mutations within a sequence increased. Conversely, not all mutations occurring in the a determinant altered the HBsAg conformation. The genotype backbone, the specific amino acid substitution and amino acid changes occurring outside the major antigenic region appeared to be important in determining expression of the predicted epitope loss. These data clearly demonstrate that sequence-based methods alone may not accurately define HBsAg phenotype. This phenotyping methodology allows for the rapid and accurate identification of antigenically altered viruses and will greatly enhance current HBV surveillance, research and diagnostic activities. The data generated can be used to inform on public health issues relating to prevalence, transmission and impact of HBsAg mutants in HBV-infected populations. PMID:22855781

  2. Prevalence of hepatitis B surface antigen among refugees entering the United States between 2006 and 2008.

    PubMed

    Rein, David B; Lesesne, Sarah B; O'Fallon, Ann; Weinbaum, Cindy M

    2010-02-01

    The Centers for Disease Control and Prevention recommends hepatitis B surface antigen (HBsAg) testing to identify chronic hepatitis B virus infection for foreign-born persons from countries or regions with HBsAg prevalence of >or=2%. However, limited data exist to indicate which countries meet this definition. To address this data gap, we estimated the HBsAg prevalence among refugees entering the United States between 2006 and 2008. We contacted state refugee health coordinators and asked them to report the number of refugees, country of origin, and HBsAg prevalence among refugees screened in their jurisdiction during the most recently available 12-month period prior to August 2008. We pooled data across jurisdictions and calculated the prevalence for any country with more than 30 refugees entering the United States, and where this level of data was not available by country, continents were considered. Of the 47 jurisdictions contacted, we received basic information from 31, with nine jurisdictions reporting HBsAg prevalence by country of origin applicable to 31,980 refugees (approximately 42% of refugees entering the United States during the observation period). We estimated an HBsAg prevalence of 2.8% (95% confidence interval 2.6%-3.0%) for refugees overall. Of the 37 countries with 30 or more refugees entering the United States, 25 had a prevalence of >or=2%. Prevalence was highest among refugees from Africa and Southeast Asia, and lowest among refugees from the Middle East and South/Central America. In the eight countries for which we had comparison data, six had lower HBsAg prevalence than in 1991.

  3. Quantitative Levels of Hepatitis B Virus DNA and Surface Antigen and the Risk of Hepatocellular Carcinoma in Patients with Hepatitis B Receiving Long-Term Nucleos(t)ide Analogue Therapy

    PubMed Central

    Kawanaka, Miwa; Nishino, Ken; Nakamura, Jun; Oka, Takahito; Urata, Noriyo; Goto, Daisuke; Suehiro, Mitsuhiko; Kawamoto, Hirofumi; Kudo, Masatoshi; Yamada, Gotaro

    2014-01-01

    Background Serum levels of hepatitis B virus (HBV) DNA are an important predictor of the risk of hepatocellular carcinoma (HCC) in patients with chronic HBV infection. However, little is known about whether high levels of hepatitis B surface antigen (HBsAg) increase the risk for HCC. Methods We investigated 167 patients who were treated with nucleos(t)ide analogues (NA) for at least 2 years (median: 5.8 years, range: 2-13.1 years). Relationships between reduced levels of HBsAg and various factors were evaluated. In addition, we evaluated the usefulness of quantitative serum levels of HBV DNA and HBsAg as predictors of HCC development in patients receiving long-term NA therapy. Results HCC developed in 9 of the 167 NA-treated patients. In the 9 patients with HCC, HBV DNA was undetectable (<2.1 log copies/mL), but HBsAg levels were ≥2000 C.O.I. in 7 patients. No maternal transmission, long NA treatment period, HBV DNA levels <3.0 log copies/mL, and reduced hepatitis B e antigen levels during the first 24 weeks of treatment were a significant factor of HBsAg levels <2000 C.O.I.. Conclusions Hepatocarcinogenesis was observed in patients with high HBsAg levels, despite the negative conversion of HBV DNA as a result of long-term NA therapy. Therefore, to suppress hepatocarcinogenesis, it is important to control not only HBV DNA levels but also HBsAg levels. PMID:24804176

  4. Expression of hepatitis B surface antigen in the methylotrophic yeast Pichia pastoris using the GAP promoter.

    PubMed

    Vassileva, A; Chugh, D A; Swaminathan, S; Khanna, N

    2001-06-01

    High-level expression and efficient assembly of Hepatitis B surface Antigen (HBsAg) particles have been reported in Pichia pastoris by integrating a single copy of the HBsAg gene under the control of the alcohol oxidase (AOX1) promoter. However, the time taken to reach peak product concentration is usually very long ( approximately 240 h). In this paper, we describe the expression of HBsAg in P. pastoris using the recently described glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter. Unlike the previously described AOX1 promoter based system (in which biomass is generated first followed by methanol-induced antigen production), biomass generation and antigen production occur simultaneously in medium containing glycerol or glucose. Maximal levels of HBsAg expression in case of the single copy AOX1 integrant (attained after 6 days of induction) exceeded the levels of antigen produced by the single copy GAP integrant. However, this was offset by continuous antigen production by the GAP clone. In an attempt to further enhance antigen production levels of the GAP clones, we isolated multicopy Pichia integrants containing up to four copies of the GAP promoter-driven constitutive expression cassette using the Zeocin screening procedure. The data demonstrated a direct correlation between the gene dosage and the levels of HBsAg expressed by the GAP clones. The effect of copy number was additive and the four copy clone resulted in about four-fold higher yield of HBsAg. The majority of HBsAg produced in the constitutive expression system was found to be of particulate form, based on sedimentation behaviour and particle-specific ELISA, suggesting that it has the potential to serve as an effective immunogen. These particles were sensitive to thiol reagents. We also explored the possibility of secreting the GAP expressed HBsAg in P. pastoris. In-frame fusion of the Saccharomyces cerevisiae alpha-factor secretion signal under the constitutive GAP promoter resulted in

  5. Hepatitis B virus infection status is an independent risk factor for multiple myeloma patients after autologous hematopoietic stem cell transplantation.

    PubMed

    Li, Juan; Liu, Junru; Huang, Beihui; Zheng, Dong; Chen, Mei; Zhou, Zhenhai; Xu, Duorong; Zou, Waiyi

    2013-06-01

    The purposes of this study were to evaluate the infection by hepatitis B virus (HBV) and its impact on survival and to provide a clinical reference for monitoring and treating HBV during and after autologous hematopoietic stem cell transplantation (ASCT) in patients with multiple myeloma (MM). A retrospective analysis of HBV infections was performed in 70 MM patients who received a sequential bortezomib-containing induction therapy and ASCT in our department from June 2006 to February 2012. Among the 70 patients in our study, 11 cases (15.7 %) were hepatitis B surface antigen positive (HBsAg+), and 23 cases (33.3 %) were hepatitis B core antibody positive (HBcAb+). Eight cases were HBsAg, hepatitis B e antibody (HBeAb), and HBcAb positive, while one case was HBsAg, hepatitis B e antigen (HBeAg), and HBcAb positive. The median follow-up times for the HBsAg+ group and the HBsAg-negative (HBsAg-) group were 27.0 (7.6-85.2) months and 28.7 (7.1-111.0) months, respectively. The 1-year, 2-year, and 3-year overall survival rates of the HBsAg+ group were 90.9, 80.8, and 34.6 %, respectively, and the median survival time was 31.2 months (95 % CI, 24.8-37.6). The 1-year, 2-year, and 3-year overall survival rates of the HBsAg- group were 98.2, 94, and 84.6 %, respectively, while the median survival time was not yet available. There was a statistically significant difference (p=0.008) in the overall survival rate between the two groups. By Cox regression analysis, we found that the HBsAg+ status was a prognostic factor, which could independently influence the overall survival rate for ASCT. In conclusion, the HBsAg+ status is an independent risk factor for patients with MM receiving ASCT. The application of standard antiviral treatment might help to overcome this risk factor. PMID:23436046

  6. Epidemiologic study of chronic hepatitis B virus infection in male volunteer blood donors in Karachi, Pakistan

    PubMed Central

    Akhtar, Saeed; Younus, Muhammad; Adil, Salman; Hassan, Farrukh; Jafri, Sarffraz Hussain

    2005-01-01

    Background The magnitude of chronic infection with hepatitis B virus (HBV) varies substantially between the countries. A better understanding of incidence and/ or prevalence of HBV infection and associated risk factors provides insight into the transmission of this infection in the community. The purpose of this investigation was to estimate the prevalence of and to identify the risk factors associated with chronic infection with HBV, as assessed by HBV surface antigen (HBsAg) positivity, in asymptomatic volunteer male blood donors in Karachi, Pakistan. Methods Consecutive blood donations made at the two large blood banks between January 1, 1998 and December 31, 2002 were assessed to estimate the prevalence of HBsAg positivity. To evaluate the potential risk factors, a case-control study design was implemented; cases (HBsAg positives) and controls (HBsAg negatives), were recruited between October 15, 2001 and March 15, 2002. A pre-tested structured questionnaire was administered through trained interviewers to collect the data on hypothesized risk factors for HBV infection. Sera were tested for HBsAg using commercially available kits for enzyme linked Immunosorbant assay-III. Results HBsAg prevalence in the male volunteer blood donors was 2.0 % (7048/351309). Multivariate logistic regression analysis showed that after adjusting for age and ethnicity, cases were significantly more likely than controls to have received dental treatment from un-qualified dental care provider (adjusted odds ratio (OR) = 9.8; 95% confidence interval (CI): 2.1, 46.1), have received 1–5 injections (adjusted OR = 3.3; 95% CI: 1.1, 9.6), more than 5 injections (adjusted OR = 1.4; 95% CI: 1.4, 12.7) during the last five years or have received injection through a glass syringe (adjusted OR = 9.4; 95% CI: 2.6, 34.3). Injury resulted in bleeding during shaving from barbers (adjusted OR = 2.3; 95% CI: 1.1, 4.8) was also significant predictor of HBsAg positivity. Conclusion Prevalence of HBsAg

  7. Analysis of processing and polyadenylation signals of the hepatitis B virus surface antigen gene by using simian virus 40-hepatitis B virus chimeric plasmids

    SciTech Connect

    Simonsen, C.C.; Levinson, A.D.

    1983-12-01

    The authors examined the transcription of the hepatitis B virus surface antigen (HBsAg) gene in COs cells transfected with simian virus 40-based recombinant plasmids. When positioned behind the simian virus 40 late promoter, three transcripts were identified which hybridized to the HBsAg gene: a 2,000-nucleotide transcript colinear with a gene, a 1,100-nucleotide transcript representing a spliced molecule in which a major portion of the sequences encoding HBsAg were deleted, and an 800-nucleotide transcript derived primarily from sequences 3' to the HBsAg gene. The splice acceptor site utilized by the 1,100-nucleotide transcript is located immediately upstream of an open reading frame of unknown function contained within the 3' nontranslated region of the HBsAg gene. The HBsAg-specific mRNA species terminate 12 to 19 base pairs 3' of the sequence UAUAAA, similar to the concensus hexanucleotide which is thought to promote polyadenylation (AAUAAA). They constructed a series of plasmids with progressive deletions from the region surrounding where these transcripts terminate. Analysis of mRNA produced by cells transfected with these plasmids indicated that the signal hexanucleotide is in itself unable to promote the efficient processing of mRNA in the absence of downstream hepatitis B virus sequences. Processing proceeds properly, however, from plasmids containing an additional 30 nucleotides 3' of this signal.

  8. HD-03/ES: A Herbal Medicine Inhibits Hepatitis B Surface Antigen Secretion in Transfected Human Hepatocarcinoma PLC/PRF/5 Cells.

    PubMed

    Varma, Sandeep R; Sundaram, R; Gopumadhavan, S; Vidyashankar, Satyakumar; Patki, Pralhad S

    2013-01-01

    HD-03/ES is a herbal formulation used for the treatment of hepatitis B. However, the molecular mechanism involved in the antihepatitis B (HBV) activity of this drug has not been studied using in vitro models. The effect of HD-03/ES on hepatitis B surface antigen (HBsAg) secretion and its gene expression was studied in transfected human hepatocarcinoma PLC/PRF/5 cells. The anti-HBV activity was tested based on the inhibition of HBsAg secretion into the culture media, as detected by HBsAg-specific antibody-mediated enzyme assay (ELISA) at concentrations ranging from 125 to 1000  μ g/mL. The effect of HD-03/ES on HBsAg gene expression was analyzed using semiquantitative multiplex RT-PCR by employing specific primers. The results showed that HD-03/ES suppressed HBsAg production with an IC50 of 380  μ g/mL in PLC/PRF/5 cells for a period of 24 h. HD-03/ES downregulated HBsAg gene expression in PLC/PRF/5 cells. In conclusion, HD-03/ES exhibits strong anti-HBV properties by inhibiting the secretion of hepatitis B surface antigen in PLC/PRF/5 cells, and this action is targeted at the transcription level. Thus, HD-03/ES could be beneficial in the treatment of acute and chronic hepatitis B infections.

  9. Liver grafts from hepatitis B surface antigen-positive donors: A review of the literature.

    PubMed

    Loggi, Elisabetta; Conti, Fabio; Cucchetti, Alessandro; Ercolani, Giorgio; Pinna, Antonio Daniele; Andreone, Pietro

    2016-09-21

    The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extended criteria, which include the use of liver from patients with signs of past or present hepatitis B virus (HBV) infection. While the use of liver grafts from donors with evidence of past HBV infection is quite limited, some data have been collected regarding the feasibility of transplanting a liver graft from a hepatitis B surface antigen (HBsAg) positive donor. The aim of the present work was to review the literature regarding liver transplants from HBsAg-positive donors. A total of 17 studies were identified by a search in Medline. To date, HBsAg positive grafts have preferentially been allocated to HBsAg positive recipients. The large majority of these patients continue to be HBsAg positive despite the use of immunoglobulin, and infection prevention can only be guaranteed by using antiviral prophylaxis. Although serological persistence is evident, no significant HBV-related disease has been observed, except in patients coinfected with delta virus. Consistently less data are available for HBsAg negative recipients, although they are mostly promising. HBsAg-positive grafts could be an additional organ source for liver transplantation, provided that the risk of reinfection/reactivation is properly prevented. PMID:27672295

  10. A Bayesian Meta-Analysis on Prevalence of Hepatitis B Virus Infection among Chinese Volunteer Blood Donors

    PubMed Central

    Liu, Guang-ying; Zheng, Yang; Deng, Yan; Gao, Yan-yan; Wang, Lie

    2013-01-01

    Background Although transfusion-transmitted infection of hepatitis B virus (HBV) threatens the blood safety of China, the nationwide circumstance of HBV infection among blood donors is still unclear. Objectives To comprehensively estimate the prevalence of HBsAg positive and HBV occult infection (OBI) among Chinese volunteer blood donors through bayesian meta-analysis. Methods We performed an electronic search in Pub-Med, Web of Knowledge, Medline, Wanfang Data and CNKI, complemented by a hand search of relevant reference lists. Two authors independently extracted data from the eligible studies. Then two bayesian random-effect meta-analyses were performed, followed by bayesian meta-regressions. Results 5957412 and 571227 donors were identified in HBsAg group and OBI group, respectively. The pooled prevalence of HBsAg group and OBI group among donors is 1.085% (95% credible interval [CI] 0.859%∼1.398%) and 0.094% (95% CI 0.0578%∼0.1655%). For HBsAg group, subgroup analysis shows the more developed area has a lower prevalence than the less developed area; meta-regression indicates there is a significant decreasing trend in HBsAg positive prevalence with sampling year (beta = −0.1202, 95% −0.2081∼−0.0312). Conclusion Blood safety against HBV infection in China is suffering serious threats and the government should take effective measures to improve this situation. PMID:24236110

  11. Complexes of hepatitis B surface antigen and immunoglobulin M in the sera of patients with hepatitis B virus infection.

    PubMed Central

    Palla, M; Rizzi, R; Toti, M; Almi, P; Rizzetto, M; Bonino, F; Purcell, R

    1983-01-01

    Hepatitis B surface antigen (HBsAg) bound to immunoglobulin M (IgM) was detected in sera of HBsAg carriers by a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. Isopycnic banding and rate-zonal sedimentation have shown that the reaction is related to particulate forms of the HBsAg complexed with IgM. The binding of IgM possibly occurred because of a selective affinity of these molecules to the surface of HBsAg particles. HBsAg/IgM was found transiently in 24 of 25 (96%) patients with acute self-limited hepatitis B and persistently in 6 of 25 patients whose acute hepatitis B progressed to chronicity. It was also found in 20 of 39 (51%) chronic HBsAg carriers with inactive and asymptomatic infection. The HBsAg/IgM phenomenon is not dependent on replication of hepatitis B virions; its persistence in patients with acute hepatitis B may provide complementary evidence of transition of the infection to chronicity. PMID:6309673

  12. Chimeric virus-like particles for the delivery of an inserted conserved influenza A-specific CTL epitope.

    PubMed

    Cheong, Wan-Shoo; Reiseger, Jessica; Turner, Stephen John; Boyd, Richard; Netter, Hans-Jürgen

    2009-02-01

    The small hepatitis B virus surface antigens (HBsAg-S) have the ability to self-assemble with host-derived lipids into empty non-infectious virus-like particles (VLPs). HBsAg-S VLPs are the sole component of the licensed hepatitis B vaccine, and they are a useful delivery platform for foreign epitopes. To develop VLPs capable of transporting foreign cytotoxic T lymphocyte (CTL) epitopes, HBsAg-S specific CTL epitopes at various sites were substituted with a conserved CTL epitope derived from the influenza matrix protein. Depending on the insertion site, the introduction of the MHC class I A2.1-restricted influenza epitope was compatible with the secretion competence of HBsAg-S indicating that chimeric VLPs were assembled. Immunizations of transgenic HHDII mice with chimeric VLPs induced anti-influenza CTL responses proving that the inserted foreign epitope can be correctly processed and cross-presented. Chimeric VLPs in the absence of adjuvant were able to induce memory T cell responses, which could be recalled by influenza virus infections in the mouse model system. The ability of chimeric HBsAg-S VLPs to induce anti-foreign CTL responses and also with the proven ability to induce humoral immune responses constitute a highly versatile platform for the delivery of selected multiple epitopes to target disease associated infectious agents.

  13. Epidemiology of hepatitis B virus infection in Albania

    PubMed Central

    Resuli, Bashkim; Prifti, Skerdi; Kraja, Bledar; Nurka, Tatjana; Basho, Mimoza; Sadiku, Edita

    2009-01-01

    AIM: To assess the prevalence and socio-demographic distribution of hepatitis B virus (HBV) infection in Albania. METHODS: Blood samples from 410 unselected schoolboys, 666 students, 500 military personnel, 1286 casual blood donors, 378 voluntary blood donors and 640 pregnant women (total 3880 non-vaccinated residents of rural and metropolitan areas from all over Albania; 2354 (60.7%) male and 1526 (39.3%) female; mean age of 26.3 years) were tested during 2004-2006 for hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B virus (anti-HBs) by ELISA. RESULTS: The HBsAg and anti-HBs prevalence were 9.5% and 28.7%, respectively. The highest HBsAg prevalence was evident in the younger age group, such as in schoolchildren (11.8%) and the military (10.6%). Consequently, the anti-HBs prevalence increased with age, from 21.2% in schoolchildren (mean age: 15.7 years), to 36.3% in pregnant women (mean age: 26.3 years) and 29.7% in voluntary blood donors (mean age: 40.1 years). There were no significant differences between males and females. CONCLUSION: Despite the estimated two-fold reduction of HBsAg prevalence in the general population from about 18%-19% to 9.5%, Albania remains a highly endemic country (i.e. over 8% of HBsAg prevalence rate). PMID:19230046

  14. Humoral and cellular immune responses by normal individuals to hepatitis B surface antigen vaccination.

    PubMed Central

    Filion, L G; Saginur, R; Szczerbak, N

    1988-01-01

    The kinetics of the cellular and humoral responses of 30 recipients of hepatitis B vaccine were studied. All individuals exerted an HBsAg blastogenic response sometime throughout the study period but the maximum response was detected on day 28 and 56. The removal of CD8+ cells enhanced significantly the HBsAg response at the times tested, whereas treatment with anti-CD4, anti-CD8, C' and anti-CD4+ C' had no effect. Vaccination also led to the depression of phytohaemagglutinin (PHA) blastogenic response. This response was maximally suppressed 4 to 8 days after immunization at least for the primary and secondary responses and 28 days after the third dose of vaccine. The humoral response to HBsAg was detected only after the second dose of vaccine was given. The results suggest that a CD8+ cell controls the magnitude and intensity of the HBsAg blastogenic response, which may help to explain why several investigators had not been able to detect this response in hyperimmunized individuals. Primary immunization with HBsAg does lead to an expansion of B memory since a secondary response anti-HBsAg was observed. PMID:2968200

  15. Asymptomatic rectal mucosal lesions and hepatitis B surface antigen at sites of sexual contact in homosexual men with persistent hepatitis B virus infection.

    PubMed

    Reiner, N E; Judson, F N; Bond, W W; Francis, D P; Petersen, N J

    1982-02-01

    To ascertain why active and passive oral-anal and genital anal intercourse correlate strongly with hepatitis B virus (HBV) infection in homosexual men, we studied 22 men with HBV infection for the presence of hepatitis B surface antigen (HBsAg) in gingival and anorectal mucosa, feces, and semen. Thirteen of 22 (59%) patients had asymptomatic rectal mucosal lesions consisting of punctate bleeding points. Seventy-seven percent of swabbed specimens from lesions, 62% from feces, 59% from rectal mucosa, and 50% from anal canal mucosa contained HBsAg. Sera diluted serially and tested for HBsAg by radioimmunoassay showed that men with serum titers of 105 or greater were more likely to have HBsAg in specimens from lesions (p = 0.034), feces (p = 0.032), and normal mucosa (p = 0.001) than men with titers under 10 5. Asymptomatic rectal bleeding is frequent in homosexual men with persistent HBV infection. Rectal mucosa, feces, and anal canal mucosa become contaminated with HBsAg, creating a setting for de facto parenteral transmission when there is contact with oral or urethral mucosa. PMID:7059064

  16. Prevalence and Seroincidence of Hepatitis B and Hepatitis C Infection in High Risk People Who Inject Drugs in China and Thailand

    PubMed Central

    Jackson, J. Brooks; Wei, Liu; Liping, Fu; Aramrattana, Apinun; Celentano, David D.; Walshe, Louise; Xing, Yi; Richardson, Paul; Jun, Ma; Beauchamp, Geetha; Donnell, Deborah; Ruan, Yuhua; Ma, Liying; Metzger, David; Shao, Yiming

    2014-01-01

    We determined the prevalence and incidence of HBV and HCV infection in people who inject drugs (PWIDs) at high risk for HIV in China and Thailand and determined the association of HBV and HCV incidence with urine opiate test results and with short-term versus long-term buprenorphine-naloxone (B-N) treatment use in a randomized clinical trial (HPTN 058). 13.8% of 1049 PWIDs in China and 13.9% of 201 PWIDs in Thailand were HBsAg positive at baseline. Among HBsAg negative participants, the HBsAg incidence rate was 2.7/100 person years in China and 0/100 person years in Thailand. 81.9% of 1049 PWIDs in China and 59.7% of 201 in Thailand were HCV antibody positive at baseline. The HCV confirmed seroincidence rate among HCV antibody negative PWIDs was 22/100 person years in China and 4.6/100 person years in Thailand. Incident HBsAg was not significantly different in the short-term versus long-term B-N arm in China or Thailand. Participants with positive opiate results in at least 75% of their urines during the time period were at increased risk of incident HBsAg (HR = 5.22; 95% CI, 1.08 to 25.22; P = 0.04) in China, but not incident HCV conversion in China or Thailand. PMID:24860664

  17. Prevalence of hepatitis B virus in patients with diabetes mellitus: a comparative cross sectional study at Woldiya General Hospital, Ethiopia

    PubMed Central

    Mekonnen, Daniel; Gebre-Selassie, Solomon; Fantaw, Surafel; Hunegnaw, Andualem; Mihret, Adane

    2014-01-01

    Introduction The overall prevalence of HBV in Ethiopia varies from 4.7-16.8% for Hepatitis B surface antigen (HBsAg) and 70-76.38% for at least one marker positive. Patients suffering from type I Diabetes Mellitus (DM) incur high risk of infection with hepatotropic viruses because of frequent hospitalization and blood tests. Methods A comparative cross sectional study was conducted at Woldiya General Hospital using 108 consented study populations from Diabetes and 108 non diabetes control groups during the period November 2010 - January 2011. VISITECT HBsAg rapid test kit and Humastat 80 chemistry analyzer were used. Multivariate logistic regression was used to see the association of HBV with clinical history of participants and Sociodemographic variables. All tests were two-sided with α-level of 0.05 and 80% power. Results Prevalence of HBsAg was equal between diabetic and non diabetic individuals, 3.7% indicating that there was no difference between the two groups. Only history of invasive procedures and chronic liver disease showed association with HBsAg seropositivity. Conclusion In this study a positive relation was not indicated between HBV and Diabetes and the prevalence of HBsAg was equal between diabetic and non diabetic individuals. PMID:24932351

  18. HD-03/ES: A Herbal Medicine Inhibits Hepatitis B Surface Antigen Secretion in Transfected Human Hepatocarcinoma PLC/PRF/5 Cells

    PubMed Central

    Varma, Sandeep R.; Sundaram, R.; Gopumadhavan, S.; Vidyashankar, Satyakumar; Patki, Pralhad S.

    2013-01-01

    HD-03/ES is a herbal formulation used for the treatment of hepatitis B. However, the molecular mechanism involved in the antihepatitis B (HBV) activity of this drug has not been studied using in vitro models. The effect of HD-03/ES on hepatitis B surface antigen (HBsAg) secretion and its gene expression was studied in transfected human hepatocarcinoma PLC/PRF/5 cells. The anti-HBV activity was tested based on the inhibition of HBsAg secretion into the culture media, as detected by HBsAg-specific antibody-mediated enzyme assay (ELISA) at concentrations ranging from 125 to 1000 μg/mL. The effect of HD-03/ES on HBsAg gene expression was analyzed using semiquantitative multiplex RT-PCR by employing specific primers. The results showed that HD-03/ES suppressed HBsAg production with an IC50 of 380 μg/mL in PLC/PRF/5 cells for a period of 24 h. HD-03/ES downregulated HBsAg gene expression in PLC/PRF/5 cells. In conclusion, HD-03/ES exhibits strong anti-HBV properties by inhibiting the secretion of hepatitis B surface antigen in PLC/PRF/5 cells, and this action is targeted at the transcription level. Thus, HD-03/ES could be beneficial in the treatment of acute and chronic hepatitis B infections. PMID:23691296

  19. HIGH RATE OF HEPATITIS B VIRUS MOTHER-TO-CHILD TRANSMISSION IN LAO PEOPLE'S DEMOCRATIC REPUBLIC.

    PubMed

    Jutavijittum, Prapan; Yousukh, Amnat; Saysanasongkham, Bounnack; Samountry, Bounthome; Samountry, Khamtim; Toriyama, Kan; Tokuda, Masaaki; Yoneyama, Hirohito; Masaki, Tsutomu

    2016-03-01

    Hepatitis B virus infection is endemic in Lao People's Democratic Republic (PDR). Among 3,000 pregnant women attending an antenatal clinic at Mother and Child Hospital in Vientiane, Lao PDR, 5.8% were HBsAg positive by a rapid test. Among serum samples of 47 infants aged 9-12 months born to HBsAg-positive mothers, 38% were anti-HBs negative. Percent anti-HBs negative children is significantly higher in those born to HBeAg positive mothers than in those born to HBeAg negative mothers (60% vs 25%, p < 0.05). Out of 47 HBsAg-positive mothers, 10 had infants who were HBsAg positive. None of the infants born to HBsAg negative mothers became HBsAg positive but 10/19 (52.6%) of infants born to HBeAg positive mothers became HBsAg positive. This high rate of mother-to-child transmission of HBV in an endemic country is of concern and indicates that routine vaccination program for Lao infants needs strengthening.

  20. Europium nanoparticle-based simple to perform dry-reagent immunoassay for the detection of hepatitis B surface antigen.

    PubMed

    Talha, Sheikh M; Salminen, Teppo; Juntunen, Etvi; Spangar, Anni; Gurramkonda, Chandrasekhar; Vuorinen, Tytti; Khanna, Navin; Pettersson, Kim

    2016-03-01

    Hepatitis B infection, caused by hepatitis B virus (HBV), presents a huge global health burden. Serological diagnosis of HBV mainly relies on the detection of hepatitis B surface antigen (HBsAg). Although there are high sensitivity commercial HBsAg enzyme immunoassays (EIAs) available, many low-resource laboratories lacking trained technicians continue to use rapid point-of-care assays with low sensitivities for HBsAg detection, due to their simplicity to operate. We developed a time-resolved fluorometric dry-reagent HBsAg immunoassay which meets the detection limit of high sensitivity EIAs but is simple to operate. To develop the assay, anti-HBsAg monoclonal antibody coated on europium nanoparticles was dried atop of biotinylated anti-HBsAg polyclonal antibody immobilized on streptavidin-coated microtiter wells. To test a sample in dry-reagent assay, serum sample and assay buffer were added to the wells, incubated, washed and europium signals were measured. The assay showed a detection limit of 0.25 ng/ml using HBsAg spiked in serum sample. When evaluated with 24 HBV positive and 37 negative serum samples, assay showed 100% sensitivity and specificity. Assay wells are stable for at least 26 weeks when stored at 4°C, and can tolerate elevated temperatures of up to 35°C for two weeks. The developed assay has high potential to be used in low-resource laboratories.

  1. Liver grafts from hepatitis B surface antigen-positive donors: A review of the literature

    PubMed Central

    Loggi, Elisabetta; Conti, Fabio; Cucchetti, Alessandro; Ercolani, Giorgio; Pinna, Antonio Daniele; Andreone, Pietro

    2016-01-01

    The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extended criteria, which include the use of liver from patients with signs of past or present hepatitis B virus (HBV) infection. While the use of liver grafts from donors with evidence of past HBV infection is quite limited, some data have been collected regarding the feasibility of transplanting a liver graft from a hepatitis B surface antigen (HBsAg) positive donor. The aim of the present work was to review the literature regarding liver transplants from HBsAg-positive donors. A total of 17 studies were identified by a search in Medline. To date, HBsAg positive grafts have preferentially been allocated to HBsAg positive recipients. The large majority of these patients continue to be HBsAg positive despite the use of immunoglobulin, and infection prevention can only be guaranteed by using antiviral prophylaxis. Although serological persistence is evident, no significant HBV-related disease has been observed, except in patients coinfected with delta virus. Consistently less data are available for HBsAg negative recipients, although they are mostly promising. HBsAg-positive grafts could be an additional organ source for liver transplantation, provided that the risk of reinfection/reactivation is properly prevented.

  2. Occult hepatitis B viral infection among blood donors in South-Eastern Nigeria.

    PubMed

    Nna, Emmanuel; Mbamalu, Chinenye; Ekejindu, Ifeoma

    2014-07-01

    Hepatitis B virus infection is endemic in many parts of sub-Saharan Africa including Nigeria. Occult hepatitis B virus infection (OBI) is a challenging clinical problem characterized by the absence of Hepatitis B surface Antigen (HBsAg) and low viral DNA load. We aimed at determining the prevalence of OBI among repeat blood donors in Abakaliki, south-eastern Nigeria. Of 113 informed consented repeat blood donors enrolled into the study, 12 donors (10·6%) tested positive to both serological HBsAg screening, anti-HBc total and hepatitis B virus (HBV) DNA Nested PCR tests. One donor (0·9%) tested HBsAg positive, anti-HBC positive but Nested PCR negative. All donors were negative for HIV 1 and 2 and HCV infections. Of the 100 HbsAg negative repeat blood donors, 8·0% (eight donors) were HBV DNA positive by nested PCR method and anti-HBc total positive by ELISA. The median viral load, determined by real time PCR-Taqman chemistry, in the OBI blood samples was 51 IU/ml compared to 228 IU/ml of the HBsAg screen positive donors. The observed OBI prevalence of 8·0% corroborated with high endemicity of HBV infection in Abakaliki. We therefore recommend routine HBV DNA testing by real time PCR method on all sero-negative blood donations in Abakaliki and for a similar policy to be evaluated across the sub-Saharan Africa. PMID:24995918

  3. Occult Hepatitis B Virus Infection among HIV Positive Patients in Nigeria.

    PubMed

    Opaleye, Oluyinka Oladele; Oluremi, Adeolu Sunday; Atiba, Adetona Babatunde; Adewumi, Moses Olubusuyi; Mabayoje, Olatunji Victor; Donbraye, Emmanuel; Ojurongbe, Olusola; Olowe, O Adekunle

    2014-01-01

    HIV has been known to interfere with the natural history of hepatitis B virus (HBV) infection. In this study we investigate the prevalence of occult hepatitis B virus infection (OBI) among HIV-infected individuals in Nigeria. Overall, 1200 archived HIV positive samples were screened for detectable HBsAg using rapid technique, in Ikole Ekiti Specialist Hospital. The HBsAg negative samples were tested for HBsAg, anti-HBc, and anti-HCV by ELISA. Polymerase chain reaction was used for HBV DNA amplification and CD4 counts were analyzed by cytometry. Nine hundred and eighty of the HIV samples were HBsAg negative. HBV DNA was detected in 21/188 (11.2%) of patients without detectable HBsAg. CD4 count for the patients ranged from 2 to 2,140 cells/ μ L of blood (mean = 490 cells/ μ L of blood). HCV coinfection was detected only in 3/188 (1.6%) of the HIV-infected patients (P > 0.05). Twenty-eight (29.2%) of the 96 HIV samples screened were positive for anti-HBc. Averagely the HBV viral load was <50 copies/mL in the OBI samples examined by quantitative PCR. The prevalence of OBI was significantly high among HIV-infected patients. These findings highlight the significance of nucleic acid testing in HBV diagnosis in HIV patients. PMID:24868208

  4. Liver grafts from hepatitis B surface antigen-positive donors: A review of the literature

    PubMed Central

    Loggi, Elisabetta; Conti, Fabio; Cucchetti, Alessandro; Ercolani, Giorgio; Pinna, Antonio Daniele; Andreone, Pietro

    2016-01-01

    The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extended criteria, which include the use of liver from patients with signs of past or present hepatitis B virus (HBV) infection. While the use of liver grafts from donors with evidence of past HBV infection is quite limited, some data have been collected regarding the feasibility of transplanting a liver graft from a hepatitis B surface antigen (HBsAg) positive donor. The aim of the present work was to review the literature regarding liver transplants from HBsAg-positive donors. A total of 17 studies were identified by a search in Medline. To date, HBsAg positive grafts have preferentially been allocated to HBsAg positive recipients. The large majority of these patients continue to be HBsAg positive despite the use of immunoglobulin, and infection prevention can only be guaranteed by using antiviral prophylaxis. Although serological persistence is evident, no significant HBV-related disease has been observed, except in patients coinfected with delta virus. Consistently less data are available for HBsAg negative recipients, although they are mostly promising. HBsAg-positive grafts could be an additional organ source for liver transplantation, provided that the risk of reinfection/reactivation is properly prevented. PMID:27672295

  5. Hepatitis B virus genome replication triggers toll-like receptor 3-dependent interferon responses in the absence of hepatitis B surface antigen.

    PubMed

    Real, Catherine Isabell; Lu, Mengji; Liu, Jia; Huang, Xuan; Trippler, Martin; Hossbach, Markus; Deckert, Jochen; Jahn-Hofmann, Kerstin; Ickenstein, Ludger Markus; John, Matthias Johannes; Gibbert, Kathrin; Dittmer, Ulf; Vornlocher, Hans-Peter; Schirmbeck, Reinhold; Gerken, Guido; Schlaak, Joerg Friedrich; Broering, Ruth

    2016-01-01

    The hepatitis B virus (HBV) has been described as stealth virus subverting immune responses initially upon infection. Impaired toll-like receptor signaling by the HBV surface antigen (HBsAg) attenuates immune responses to facilitate chronic infection. This implies that HBV replication may trigger host innate immune responses in the absence of HBsAg. Here we tested this hypothesis, using highly replicative transgenic mouse models. An HBV replication-dependent expression of antiviral genes was exclusively induced in HBsAg-deficient mice. These interferon responses attributed to toll-like receptor 3 (TLR3)-activated Kupffer and liver sinusoidal endothelial cells and further controlled the HBV genome replication. However, activation of TLR3 with exogenous ligands indicated additional HBs-independent immune evasion events. Our data demonstrate that in the absence of HBsAg, hepatic HBV replication leads to Tlr3-dependent interferon responses in non-parenchymal liver cells. We hypothesize that HBsAg is a major HBV-mediated evasion mechanism controlling endogenous antiviral responses in the liver. Eradication of HBsAg as a therapeutic goal might facilitate the induction of endogenous antiviral immune responses in patients chronically infected with HBV. PMID:27121087

  6. Hepatitis B virus genome replication triggers toll-like receptor 3-dependent interferon responses in the absence of hepatitis B surface antigen

    PubMed Central

    Real, Catherine Isabell; Lu, Mengji; Liu, Jia; Huang, Xuan; Trippler, Martin; Hossbach, Markus; Deckert, Jochen; Jahn-Hofmann, Kerstin; Ickenstein, Ludger Markus; John, Matthias Johannes; Gibbert, Kathrin; Dittmer, Ulf; Vornlocher, Hans-Peter; Schirmbeck, Reinhold; Gerken, Guido; Schlaak, Joerg Friedrich; Broering, Ruth

    2016-01-01

    The hepatitis B virus (HBV) has been described as stealth virus subverting immune responses initially upon infection. Impaired toll-like receptor signaling by the HBV surface antigen (HBsAg) attenuates immune responses to facilitate chronic infection. This implies that HBV replication may trigger host innate immune responses in the absence of HBsAg. Here we tested this hypothesis, using highly replicative transgenic mouse models. An HBV replication-dependent expression of antiviral genes was exclusively induced in HBsAg-deficient mice. These interferon responses attributed to toll-like receptor 3 (TLR3)-activated Kupffer and liver sinusoidal endothelial cells and further controlled the HBV genome replication. However, activation of TLR3 with exogenous ligands indicated additional HBs-independent immune evasion events. Our data demonstrate that in the absence of HBsAg, hepatic HBV replication leads to Tlr3-dependent interferon responses in non-parenchymal liver cells. We hypothesize that HBsAg is a major HBV-mediated evasion mechanism controlling endogenous antiviral responses in the liver. Eradication of HBsAg as a therapeutic goal might facilitate the induction of endogenous antiviral immune responses in patients chronically infected with HBV. PMID:27121087

  7. [Hepatitis B and delta: the prevalence of seroepidemiological markers in volunteer blood donors and their families].

    PubMed

    Alvarez-Muñoz, M T; Bustamante-Calvillo, M E; Guiscafré-Gallardo, J P; Muñoz, O

    1991-01-01

    41 volunteer blood donors and his relatives were studied in order to know about the prevalence of hepatitis B and D virus infections in selected groups. Frequency of HBsAg+ carriers was 0.34 per cent in the Centro Nacional de la Transfusión Sanguínea and 0.15 per cent in the Banco Central de Sangre, IMSS. Most of the HBsAg+ blood donors were 21 to 40 years old (87.8%); 21.9 per cent had IgM antibodies against HBc and just 2.4 per cent were HBeAg positive. Forty one (26.9%) of 152 relatives had one or more of the HBV markers, 3.9 per cent were HBsAg carriers and 1.3 per cent were HBeAg positive. In the infected relatives group 36.6 per cent were ancestory or brothers and just 14.6 per cent of wives were infected. None of the HBsAg+ blood donors or his relatives had antibodies against delta agent. These results support the fact that the frequency of asymptomatic carriers of HBsAg in the volunteer blood donors group is similar to he frequency in the general population and identifies the group of relatives as those with the highest risk to acquire HBV infection.

  8. Annual ADP planning document

    NASA Technical Reports Server (NTRS)

    Mogilevsky, M.

    1973-01-01

    The Category A computer systems at KSC (Al and A2) which perform scientific and business/administrative operations are described. This data division is responsible for scientific requirements supporting Saturn, Atlas/Centaur, Titan/Centaur, Titan III, and Delta vehicles, and includes realtime functions, Apollo-Soyuz Test Project (ASTP), and the Space Shuttle. The work is performed chiefly on the GEL-635 (Al) system located in the Central Instrumentation Facility (CIF). The Al system can perform computations and process data in three modes: (1) real-time critical mode; (2) real-time batch mode; and (3) batch mode. The Division's IBM-360/50 (A2) system, also at the CIF, performs business/administrative data processing such as personnel, procurement, reliability, financial management and payroll, real-time inventory management, GSE accounting, preventive maintenance, and integrated launch vehicle modification status.

  9. Assessment of candidate-expendable launch vehicles for large payloads

    NASA Technical Reports Server (NTRS)

    1984-01-01

    In recent years the U.S. Air Force and NASA conducted design studies of 3 expendable launch vehicle configurations that could serve as a backup to the space shuttle--the Titan 34D7/Centaur, the Atlas II/Centaur, and the shuttle-derived SRB-X--as well as studies of advanced shuttle-derived launch vehicles with much larger payload capabilities than the shuttle. The 3 candidate complementary launch vehicles are judged to be roughly equivalent in cost, development time, reliability, and payload-to-orbit performance. Advanced shuttle-derived vehicles are considered viable candidates to meet future heavy lift launch requirements; however, they do not appear likely to result in significant reduction in cost-per-pound to orbit.

  10. TC-2 post Helios experiment data review. [postflight systems analysis of spacecraft performance

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Data are presented from a systems postflight analysis of the Centaur Launch Vehicle and Helios. Also given is a comparison of data from preflight analyses. Topics examined are: (1) propellant behavior; (2) helium usage; (3) propellant tank pressurization; (4) propellant tank thermodynamics; (5) component heating; thermal control; and thermal protection system; (6) main engine system; (7) H2O2 consumption; (8) boost pump post-meco performance; and (9) an overview of other systems.

  11. NEOWISE Diameters and Albedos V1.0

    NASA Astrophysics Data System (ADS)

    Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; Nugent, C. R.; Sonnett, S. M.; Stevenson, R. A.; Wright, E. L.

    2016-06-01

    This PDS data set represents a compilation of published diameters, optical albedos, near-infrared albedos, and beaming parameters for minor planets detected by NEOWISE during the fully cryogenic, 3-band cryo, post-cryo and NEOWISE-Reactivation Year 1 operations. It contains data covering near-Earth asteroids, Main Belt asteroids, active Main Belt objects, Hildas, Jupiter Trojans, Centaurs, and Jovian and Saturnian irregular satellites. Methodology for physical property determination is described in the referenced articles.

  12. Mariner Mars 1971: Press kit

    NASA Technical Reports Server (NTRS)

    Mittauer, R. T.

    1971-01-01

    The news release describes the 1971 launches of Mariner 8 and 9 which were to be the first attempt by NASA to orbit another planet, Mars. Described are: (1) mission capsule; (2) planetary missions; (3) aiming zones; (4) the spacecraft; (5) scientific experiments to be performed; (6) Atlas Centaur launch vehicle; (7) launch operations; (8) tracking and data system and mission operations; and (9) Mariner Mars 71 team and subcontractors.

  13. Space science

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A fact sheet on the NASA space science program is presented. Some of the subjects considered include the following: (1) the Orbiting Astronomical Observatory, (2) the Orbiting Solar Observatory, (3) the Small Astronomy Satellite, (4) lunar programs, (5) planetary programs using the Mariner, Pioneer 10, and Viking space probes, and (6) the Scout, Thor-Delta, and Atlas-Centaur launch vehicles. For each program there is a description of the effort, the schedule, management, program officials, and funding aspects in outline form.

  14. Systems design study of the Pioneer Venus spacecraft. Volume 1. Technical analyses and tradeoffs, sections 1-4 (part 1 of 4)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The results are reported of the Pioneer Venus studies from 2 October 1972 through 30 June 1973. Many missions were considered, involving two launch vehicles (Thor/Delta and Atlas/Centaur), and different launch opportunities and spacecraft configurations to meet varying science requirements, all at minimum cost. The sequence of events is described and the specific studies conducted are summarized. The effects of science payload on mission and spacecraft design are discussed along with the mission analyses.

  15. System design of the Pioneer Venus spacecraft. Volume 4: Probe bus and orbiter spacecraft vehicle studies

    NASA Technical Reports Server (NTRS)

    Bozajian, J. M.

    1973-01-01

    The requirements, trades, and design descriptions for the probe bus and orbiter spacecraft configurations, structure, thermal control, and harness are defined. Designs are developed for Thor/Delta and Atlas/Centaur launch vehicles with the latter selected as the final baseline. The major issues examined in achieving the baseline design are tabulated. The importance of spin axis orientation because of the effect on science experiments and earth communications is stressed.

  16. Centaurus

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Centaur; abbrev. Cen, gen. Centauri; area 1060 sq. deg.) A southern constellation which lies between Vela and Lupus, and surrounds Crux on three sides. It culminates at midnight in early April. Its origin dates back at least to ancient Greece, where it was identified with Chiron in Greek mythology. The brightest stars of Centaurus were cataloged by Ptolemy (c. AD 100-175) in the Almagest....

  17. Ara

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Altar; abbrev. Ara, gen. Arae; area 237 sq. deg.) A southern constellation that lies between Scorpius and Apus, and culminates at midnight in early June. It is said to represent the altar upon which in Greek mythology the gods swore allegiance before their battle against the Titans, and that upon which Chiron, the centaur, is about to sacrifice Lupus, the wolf (which was a neighboring conste...

  18. Intelsat satellite scheduled for launch

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The launch schedule for Intelsat 5-B, the prime Intelsat satellite to provide communications services between the Americas, Europe, the Middle East, and Africa, is presented. The planned placement of the satellite into an elliptical transfer orbit, and circularization of the orbit at geosynchronous altitude over the equator are described. Characteristics of the Atlas Centaur launch vehicle, AC-56, are given. The launch operation is summarized and the launch sequence presented. The Intelsat team and contractors are listed.

  19. MARINER 9 SPACE PROBE UNDERGOES FINAL CHECKS PRIOR TO ENCAPSULATION

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A technician checks the Mariner I spacecraft prior to its encapsulation for launch to Mars. An Atlas-Centaur rocket successfully launched the mars-bound spacecraft from Cape Kennedy at 6:23 p.m. EDT, May 30, 1971. Designated Mariner 9 following launch, the probe will arrive at Mars in mid-November. It will transmit scientific data about that planet's surface and atmosphere.

  20. An autonomous rendezvous and docking system using cruise missile technology

    NASA Technical Reports Server (NTRS)

    Jones, ED; Nicholson, Bruce

    1991-01-01

    In November 1990 General Dynamics demonstrated an AR&D system for members of the Strategic Avionics Technology Working Group. This simulation utilized prototype hardware derived from the Cruise Missile and Centaur avionics systems. The object of this proof of concept demonstration was to show that all the accuracy, reliability, and operational requirements established for a spacecraft to dock with Space Station Freedom could be met by the proposed AR&D system.

  1. Summary of Saturn swingby missions to Uranus

    NASA Technical Reports Server (NTRS)

    Manning, L. A.

    1973-01-01

    The interplanetary trajectory characteristics for missions to Uranus, which employ an intermediate swingby of Saturn to reduce the total trip time are summarized. Opportunities for such swingby missions will occur from 1979 through 1987 and not again until 2025. The general trajectory characteristics (C sub 3; departure, swingby, and arrival dates; swingby radius; and arrival speed) are evaluated, and payload and launch window information for a Titan 3E/Centaur/TE-364-4 class launch vehicle is provided.

  2. Physical Properties of Cometary Nucleus Candidates

    NASA Technical Reports Server (NTRS)

    Jewitt, David; Hillman, John (Technical Monitor)

    2003-01-01

    In this proposal we aim to study the physical properties of the Centaurs and the dead comets, these being the precursors to, and the remnants from, the active cometary nuclei. The nuclei themselves are very difficult to study, because of the contaminating effects of near-nucleus coma. Systematic investigation of the nuclei both before they enter the zone of strong sublimation and after they have depleted their near-surface volatiles should neatly bracket the properties of these objects, revealing evolutionary effects.

  3. SIRTF cryo-optics technology plan

    NASA Technical Reports Server (NTRS)

    Norris, David D.

    1993-01-01

    A study was undertaken, early in 1992, to determine if a SIRTF class mission could be developed to allow the Observatory to be launched on an Atlas IIAS rather than the Titan IV/Centaur previously planned. The substantial mass reduction required to make that change resulted in a new set of requirements for science and a heightened interest in light weight optics. This paper addresses the rationale and plan for the Atlas SIRTF cryo-optics technology plan.

  4. Cassini's Digital Video Disk is on display in the PHSF

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In the Payload Hazardous Servicing Facility (PHSF), a Digital Video Disk (DVD) bearing 616,400 digitized signatures of people from nations around the world is attached to the Cassini spacecraft and will soon to be on its way to Saturn. The Cassini spacecraft is scheduled for launch on an Air Force Titan IV/Centaur launch vehicle on Oct. 6, 1997, and is destined to arrive at Saturn in July 2004.

  5. Conical isogrid adapter structural test results

    NASA Technical Reports Server (NTRS)

    Dyer, J. E.; Slysh, P.

    1974-01-01

    The structural characteristics of isogrid composite structures are discussed. To demonstrate the feasibility of applying isogrid to conical structures, a full scale flanged isogrid conical adapter similar to the configuration of the D-1 Centaur equipment module was constructed. The adapter was tested to evaluate the response of the conical isogrid structure to various combinations of bending and axial compression loading. The analysis techniques for predicting conical isogrid structural capability are examined.

  6. System design of the Pioneer Venus spacecraft. Volume 5: Probe vehicle studies

    NASA Technical Reports Server (NTRS)

    Nolte, L. J.; Stephenson, D. S.

    1973-01-01

    A summary of the key issues and studies conducted for the Pioneer Venus spacecraft and the resulting probe designs are presented. The key deceleration module issues are aerodynamic configuration and heat shield material selection. The design and development of the pressure vessel module are explained. Thermal control and science integration of the pressure vessel module are explained. The deceleration module heat shield, parachute and separation/despin are reported. The Thor/Delta and Atlas/Centaur baseline descriptions are provided.

  7. Future space transportation systems. Part 1: Safety aspects. Part 2: Technical aspects

    NASA Astrophysics Data System (ADS)

    Ploechinger, Ludwig; Kuczera, Heribert

    Damage statistics on Ariane, Atlas Centaur and Delta flights are examined. The modifications demanded by insurance companies for the Ariane 1, 2 and 3 boosters, equipment bay and first stage reinforcement are reviewed and the new concept of Ariane 5 is described. The progress in horizontal takeoff and landing aircraft with airbreathing propulsion are examined and the German Saenger and its hypersonic technology program are described.

  8. Nature vs. nurture debate on TNO carbons: constraints from Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Brunetto, R.

    2012-02-01

    We compare spectroscopic data of irradiated laboratory analogs with those of an interplanetary dust particle of cometary origin. We investigate if this comparison can help constraining the origin of carbonaceous materials on small icy bodies in the outer Solar System (TNOs, Centaurs, etc.). We suggest that Raman spectroscopy can help in interpreting the observed heterogeneity of the extraterrestrial carbonaceous component and in constraining the irradiation dose accumulated in space.

  9. Advanced coal-fueled industrial cogeneration gas turbine system

    SciTech Connect

    LeCren, R.T.; Cowell, L.H.; Galica, M.A.; Stephenson, M.D.; Wen, C.S.

    1990-07-01

    The objective of the Solar/METC program is to prove the technical, economic, and environmental feasibility of coal-fired gas turbine for cogeneration applications through tests of a Centaur Type H engine system operated on coal fuel throughout the engine design operating range. This quarter, work was centered on design, fabrication, and testing of the combustor, cleanup, fuel specifications, and hot end simulation rig. 2 refs., 59 figs., 29 tabs.

  10. Comet candidates among quasi-Hilda objects

    NASA Astrophysics Data System (ADS)

    Gil-Hutton, R.; García-Migani, E.

    2016-05-01

    Aims: We present the results of a search for quasi-Hilda comets. We wanted to find objects that have recently arrived from the Centaur zone that could became active near the perihelion of their orbits. Methods: Two hundred and seventy-seven objects from the ASTORB database were selected following a dynamical criteria to constrain the unstable quasi-Hilda region. These objects were integrated backward 50 000 yr in order to identify those that have recently arrived from the outer regions of the solar system. Results: The backward integration showed that 11 objects could be Centaurs or transneptunian objects that ended their dynamical evolution as quasi-Hilda comets. The dynamical evolution of these objects from a statistical point of view was studied by computing the time-averaged distribution of a number of clones as a function of the aphelion and perihelion distances. All the candidates show a dynamical behavior that is expected for comets injected in the inner solar system from the Centaur or transneptunian regions and reaching the quasi-Hilda region.

  11. The Rings of Chariklo under Close Encounters with the Giant Planets

    NASA Astrophysics Data System (ADS)

    Araujo, R. A. N.; Sfair, R.; Winter, O. C.

    2016-06-01

    The Centaur population is composed of minor bodies wandering between the giant planets that frequently perform close gravitational encounters with these planets, leading to a chaotic orbital evolution. Recently, the discovery of two well-defined narrow rings was announced around the Centaur 10199 Chariklo. The rings are assumed to be in the equatorial plane of Chariklo and to have circular orbits. The existence of a well-defined system of rings around a body in such a perturbed orbital region poses an interesting new problem. Are the rings of Chariklo stable when perturbed by close gravitational encounters with the giant planets? Our approach to address this question consisted of forward and backward numerical simulations of 729 clones of Chariklo, with similar initial orbits, for a period of 100 Myr. We found, on average, that each clone experiences during its lifetime more than 150 close encounters with the giant planets within one Hill radius of the planet in question. We identified some extreme close encounters that were able to significantly disrupt or disturb the rings of Chariklo. About 3% of the clones lose their rings and about 4% of the clones have their rings significantly disturbed. Therefore, our results show that in most cases (more than 90%), the close encounters with the giant planets do not affect the stability of the rings in Chariklo-like systems. Thus, if there is an efficient mechanism that creates the rings, then these structures may be common among these kinds of Centaurs.

  12. The discovery of Chiron's cave, a prehistoric school of medicine for animals and humans

    PubMed Central

    Hausmann, Walter; Jöchle, Wolfgang

    1988-01-01

    Chiron the centaur, mythical inventor of medicine for animals and humans, and emblem of numerous veterinary associations worldwide, is possibly an historic personality of the prehomeric period (ca 1300 B.C.) Only 600 to 700 years later did the legend form that centaurs (in antique Greek: “hunters on horseback of the wild bull”) were wild creatures, half horse and half man, and associated with uncontrolled libido and its socially destructive forces. According to tradition, literary as well as folkloric, Chiron taught his medicine to the ruling class of his time in a specially prepared cave in the Pelion Mountains (=the healing mountains) of Eastern Thessalia. Following leads from ancient authors and local traditions, a cave fitting the location and description was discovered in 1981 by the senior author. Details about its location, and observations about its surroundings, including ancient and modern place names indicate once more that Chiron, the centaur, stands for an historic personality. ImagesFigure 2.Figure 3.Figure 4. PMID:17423157

  13. Electric orbit transfer vehicle cryogenic propellant system

    NASA Astrophysics Data System (ADS)

    Schuster, J. R.; Huynh, C. T.; Williams, G. E.

    An electric orbit transfer vehicle (EOTV) is intended to transfer payloads from low Earth orbit (LEO) to higher orbits using low-thrust solar-electric propulsion and hydrogen propellant. Because of its high specific impulse and synergistic sharing of power supply, attitude control and communication systems with the payload, the highly efficient EOTV transfer stage permits use of a smaller, less costly launch vehicle than if orbit transfer were accomplished using chemical propulsion. Study of the propellant storage and supply system for an EOTV intended to fly a 168 day spiral trajectory from LEO to geosynchronous orbit (GEO) reveals that the low propellant flow rate needed by the thrusters can be supplied by the boil-off from the storage tank, eliminating the need for any overboard venting. The tank can be fabricated under the same pressure-stabilized, thin, stainless steel monocoque construction as the current Centaur upper stage, and insulated with Centaur fixed foam and MLI. The tank contains a thermodynamic vent system (TVS) for control of tank pressure in zero and low gravity and for supply of propellant to the thrusters. An external compressor, accumulator and regulator condition the hydrogen boil-off provided by the TVS and provide for start-up and shut-down transients. The resulting system is simple, has a very low structural mass fraction and builds on the Centaur cryogenic upper stage technology, which has been operational for over 25 years.

  14. An analytical study of reduced-gravity flow dynamics

    NASA Technical Reports Server (NTRS)

    Bradshaw, R. D.; Kramer, J. L.; Zich, J. L.

    1976-01-01

    Addition of surface tension forces to a marker-and-cell code and the performance of four incompressible fluid simulations in reduced gravity, were studied. This marker-and-cell code has a variable grid capability with arbitrary curved boundaries and time dependent acceleration fields. The surface tension logic includes a spline fit of surface marker particles as well as contact angle logic for straight and curved wall boundaries. Three types of flow motion were simulated with the improved code: impulsive settling in a model Centaur LH2 tank, continuous settling in a model and full scale Centaur LO2 tank and mixing in a Centaur LH2 tank. The impulsive settling case confirmed a drop tower analysis which indicated more orderly fluid collection flow patterns with this method providing a potential savings in settling propellants. In the LO2 tank, fluid collection and flow simulation into the thrust barrel were achieved. The mixing simulation produced good results indicating both the development of the flow field and fluid interface behavior.

  15. Formation of Centaurs’ Rings through Their Partial Tidal Disruption during Planetary Encounters

    NASA Astrophysics Data System (ADS)

    Hyodo, Ryuki; Charnoz, Sébastien; Genda, Hidenori; Ohtsuki, Keiji

    2016-09-01

    Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one or more giant planets. Recent observations and reinterpretation of previous observations have revealed the existence of ring systems around 10199 Chariklo and 2060 Chiron. However, the origin of the ring systems around such a minor planet is still an open question. Here, we propose that the tidal disruption of a differentiated object that experiences a close encounter with a giant planet could naturally form diverse ring–satellite systems around the Centaurs. During the close encounter, the icy mantle of the passing object is preferentially ripped off by the planet's tidal force and the debris is distributed mostly within the Roche limit of the largest remnant body. Assuming the existence of a 20‑50 wt% silicate core below the icy mantle, a disk of particles is formed when the objects pass within 0.4–0.8 of the planet's Roche limit with the relative velocity at infinity 3‑6 km s‑1 and 8 hr initial spin period of the body. The resultant ring mass is 0.1%–10% of the central object's mass. Such particle disks are expected to spread radially, and materials spreading beyond the Roche limit would accrete into satellites. Our numerical results suggest that ring formation would be a natural outcome of such extreme close encounters, and Centaurs can naturally have such ring systems because they cross the orbits of the giant planets.

  16. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1992-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  17. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1991-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  18. Is There Water on the Moon? NASA's LCROSS Mission [Supplemental Video

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Presents a supplemental video supporting the original conference presentation under the same title. The conference presentation discussed NASA's preparation for its return to the moon with the Lunar CRater Observation and Sensing Satellite (LCROSS) mission which will robotically seek to determine the presence of water ice at the Moon's South Pole. This secondary payload spacecraft will travel with the Lunar Reconnaissance Orbiter (LRO) satellite to the Moon on the same Atlas-V 401 Centaur rocket launched from Cape Canaveral Air Force Station, Florida. The 1000kg Secondary Payload budget is efficiently used to provide a highly modular and reconfigurable LCROSS Spacecraft with extensive heritage to accurately guide the expended Centaur into the crater. Upon separation, LCROSS flies through the impact plume, telemetering real-time images and characterizing water ice in the plume with infrared cameras and spectrometers. LCROSS then becomes a 700kg impactor itself, to provide a second opportunity to study the nature of the Lunar Regolith. LCROSS provides a critical ground-truth for Lunar Prospector and LRO neutron and radar maps, making it possible to assess the total lunar water inventory. The video contains an animated simulation of the Centaur launch, LRO separation, LRO high resolution lunar survey, LCROSS mission elements and LCROSS impactor separation and impact observations.

  19. A Basic Robotic Excavator (the Glenn Digger): Description, Design, and Initial Operation

    NASA Technical Reports Server (NTRS)

    Bauman, Steve; Newman, Paul; Izadnegahdar, Alain; Johnson, Kyle; Abel, Phillip

    2016-01-01

    This paper describes the design, commercial part selections, fabrication, assembly, installation, and initial operation of a two degree of freedom robotic excavator. Colloquially referred to as "the NASA Glenn Digger," it was designed specifically to be mounted onto, and to operate with, the then newly developed Centaur 2 robotic mobility base. The excavator, when mounted to Centaur 2, is designed to scoop loose regolith from the terrain, raise its loaded bucket up and dump the load into a hopper of at least a 1-m-height. The hopper represents the input to a machine that would process the raw material, such as to produce oxygen from lunar regolith as would be required for long-term lunar habitation. This equipment debuted at the annual Research and Technology Studies ("Desert RATS", Ref. 1) event held north of Flagstaff, Arizona, in September of 2010, when the Digger was successfully joined to Centaur 2 and the shoveling articulation was demonstrated. During 2011, the hardware was modified for added strength, strain gauges were added to measure loads, and the controls were improved in preparation for the 2011 Desert RATS event, where additional "field operations" experience was gained.

  20. Symbolics of the constellations of sagittarius and centaurus in russian traditional culture

    NASA Astrophysics Data System (ADS)

    Bagdasarov, R.

    2001-12-01

    Centaurus falls into the category of 'imaginary animals'. The Russian tradition used not only the symbol Sgr (a result of its acquaintance with the circle of Zodiac), but also the symbol Cen, which fact, as we shall demonstrate, is an evidence of certain mythological-astronomical conceptions. Both the constellations Sagittarius (Sgr) and Centaurus (Cen) are usually represented as versions of the picture of a fantastic being, a Centaur, shaped as man from head to waist, and as an animal, mostly, a horse, from waist down. 'Centaurus' (from the Greek word kev (or kevw)) for 'kill' and o, for 'bull') means 'bull killer', and is probably related to the opposition of the zodiacal constellations Taurus and Sagittarius. When the latter begins to rise on to the night sky, the former disappears completely from view. Sagittarius is represented at ancient monuments related to astronomy as a centaur holding a bow and pointing at certain stars. The constellation of Centaurus is also symbolised by a centaur, but holding not a bow, but a staff or a spear in one hand and an 'animal of sacrifice' in the other (Higinus, Astronomica, III, 37, 1; Chernetsov, 1975, Figure 1). The attributes stand for the Peliases Spear (The Mithological Dictionary, 1991), depicted in astrological maps as The Spear of Centaurus1, The Wolf (Lupus), the Panther or the Beast (Flammarion, 1994).

  1. KSC-05PD-1260

    NASA Technical Reports Server (NTRS)

    2005-01-01

    KENNEDY SPACE CENTER, FLA. At the Cape Canaveral Air Force Station Skid Strip, a large crane is attached to the offloaded second stage Centaur (Block I) to lift and place it on a flat bed truck. The Centaur arrived on a Russian Antonov AH-124-100 cargo airplane. The Centaur upper stage will be mated with the Lockheed Martin Atlas V, designated AV-007, that is the launch vehicle for the Mars Reconnaissance Orbiter (MRO). The MRO is designed for a series of global mapping, regional survey and targeted observations from a near-polar, low-altitude Mars orbit. These observations will be unprecedented in terms of the spatial resolution and coverage achieved by the orbiters instruments as they observe the atmosphere and surface of Mars while probing its shallow subsurface as part of a follow the water strategy. The orbiter is undergoing environmental tests in facilities at Lockheed Martin Space Systems in Denver, Colo., and is on schedule for a launch window that begins Aug. 10. Launch will be from Launch Complex 41 at Cape Canaveral Air Force Station in Florida.

  2. Formation of Centaurs’ Rings through Their Partial Tidal Disruption during Planetary Encounters

    NASA Astrophysics Data System (ADS)

    Hyodo, Ryuki; Charnoz, Sébastien; Genda, Hidenori; Ohtsuki, Keiji

    2016-09-01

    Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one or more giant planets. Recent observations and reinterpretation of previous observations have revealed the existence of ring systems around 10199 Chariklo and 2060 Chiron. However, the origin of the ring systems around such a minor planet is still an open question. Here, we propose that the tidal disruption of a differentiated object that experiences a close encounter with a giant planet could naturally form diverse ring-satellite systems around the Centaurs. During the close encounter, the icy mantle of the passing object is preferentially ripped off by the planet's tidal force and the debris is distributed mostly within the Roche limit of the largest remnant body. Assuming the existence of a 20-50 wt% silicate core below the icy mantle, a disk of particles is formed when the objects pass within 0.4-0.8 of the planet's Roche limit with the relative velocity at infinity 3-6 km s-1 and 8 hr initial spin period of the body. The resultant ring mass is 0.1%-10% of the central object's mass. Such particle disks are expected to spread radially, and materials spreading beyond the Roche limit would accrete into satellites. Our numerical results suggest that ring formation would be a natural outcome of such extreme close encounters, and Centaurs can naturally have such ring systems because they cross the orbits of the giant planets.

  3. Advanced coal-fueled industrial cogeneration gas turbine system: Hot End Simulation Rig

    SciTech Connect

    Galica, M.A.

    1994-02-01

    This Hot End Simulation Rig (HESR) was an integral part of the overall Solar/METC program chartered to prove the technical, economic, an environmental feasibility of a coal-fueled gas turbine, for cogeneration applications. The program was to culminate in a test of a Solar Centaur Type H engine system operated on coal slurry fuel throughput the engine design operating range. This particular activity was designed to verify the performance of the Centaur Type H engine hot section materials in a coal-fired environment varying the amounts of alkali, ash, and sulfur in the coal to assess the material corrosion. Success in the program was dependent upon the satisfactory resolution of several key issues. Included was the control of hot end corrosion and erosion, necessary to ensure adequate operating life. The Hot End Simulation Rig addressed this important issue by exposing currently used hot section turbine alloys, alternate alloys, and commercially available advanced protective coating systems to a representative coal-fueled environment at turbine inlet temperatures typical of Solar`s Centaur Type H. Turbine hot end components which would experience material degradation include the transition duct from the combustor outlet to the turbine inlet, the shroud, nozzles, and blades. A ceramic candle filter vessel was included in the system as the particulate removal device for the HESR. In addition to turbine material testing, the candle material was exposed and evaluated. Long-term testing was intended to sufficiently characterize the performance of these materials for the turbine.

  4. High titre of antibody to hepatitis B core antigen detected by immune adherence haemagglutination in HBsAg-positive acute hepatitis.

    PubMed

    Ikegami, F; Takasu, S; Jo, K; Miyakawa, Y; Tsuda, F; Mayumi, M

    1982-08-01

    Nine patients with HBsAg-positive acute hepatitis were tested for antibody to hepatitis B core antigen (anti-HBc) by the immune adherence haemagglutination method. A high anti-HBc titre (2(15) or more) was found in three, while anti-HBc was not detectable in the remaining six. All of them recovered from hepatitis with the return of hepatic function tests to normal, but HBsAg persisted in the three patients whose acute-phase serum had revealed high anti-HBc titres. On the basis of these observations, the three patients were thought to be persistent HBsAg carriers who had contracted opportunistic acute hepatitis of non-B aetiology. Titration of anti-HBc may be indicated in patients with HBsAg-positive acute hepatitis, because it helps distinguish persistent HBsAg carriers with non-B hepatitis from patients with hepatitis B at the outset, during the episode of acute hepatitis.

  5. [Frequency of encountering markers of viral hepatitis A, B, and C in the aboriginal inhabitants of the northwest region of Siberia].

    PubMed

    Netesova, I G; Iaroslavtseva, O A; Dryga, S A; Posukh, O L; Osipova, L P; Bronshteĭn, E L; Zaĭtsev, S A; Netesov, S V

    1995-01-01

    A minor population of Nenets living near the village of Samburg in the Purov District, Tyumen region was screened for serological markers of virus hepatitides A, B, and C (VHA, HVB, and HVC, respectively). Commercial kits manufactured by VectorBest JSC, Russia, were used. All the tested sera contained antiHVA IgG; IgM antibodies to VHA were detected in none of the tested sera, anti-HVC IgG were found in 1 (0.93%) serum, antiHBc IgG in 11 (10.2%), and HBsAg was detected in 2 (1.85%) serum samples. The sera positive by antiHBc IgG and HBsAg were tested for DNA by the polymerase chain reaction. HVB DNA was found in two HBsAg-positive sera with the HBsAg subtype determined as "non ad".

  6. [Frequency of encountering markers of viral hepatitis A, B, and C in the aboriginal inhabitants of the northwest region of Siberia].

    PubMed

    Netesova, I G; Iaroslavtseva, O A; Dryga, S A; Posukh, O L; Osipova, L P; Bronshteĭn, E L; Zaĭtsev, S A; Netesov, S V

    1995-01-01

    A minor population of Nenets living near the village of Samburg in the Purov District, Tyumen region was screened for serological markers of virus hepatitides A, B, and C (VHA, HVB, and HVC, respectively). Commercial kits manufactured by VectorBest JSC, Russia, were used. All the tested sera contained antiHVA IgG; IgM antibodies to VHA were detected in none of the tested sera, anti-HVC IgG were found in 1 (0.93%) serum, antiHBc IgG in 11 (10.2%), and HBsAg was detected in 2 (1.85%) serum samples. The sera positive by antiHBc IgG and HBsAg were tested for DNA by the polymerase chain reaction. HVB DNA was found in two HBsAg-positive sera with the HBsAg subtype determined as "non ad". PMID:7483569

  7. Infection with hepatitis B and C virus in Europe: a systematic review of prevalence and cost-effectiveness of screening

    PubMed Central

    2013-01-01

    Background Treatment for chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection is improving but not benefiting individuals unaware to be infected. To inform screening policies we assessed (1) the hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus antibody (anti-HCV-Ab) prevalence for 34 European countries; and (2) the cost-effectiveness of screening for chronic HBV and HCV infection. Methods We searched peer-reviewed literature for data on HBsAg and anti-HCV-Ab prevalence and cost-effectiveness of screening of the general population and five subgroups, and used data for people who inject drugs (PWID) and blood donors from two European organizations. Of 1759 and 468 papers found in the prevalence and cost-effectiveness searches respectively, we included 124 and 29 papers after assessing their quality. We used decision rules to calculate weighted prevalence estimates by country. Results The HBsAg and anti-HCV-Ab prevalence in the general population ranged from 0.1%-5.6% and 0.4%-5.2% respectively, by country. For PWID, men who have sex with men and migrants, the prevalence of HBsAg and anti-HCV-Ab was higher than the prevalence in the general population in all but 3 countries. There is evidence that HCV screening of PWID and HBsAg screening of pregnant women and migrants is cost-effective. Conclusion The prevalence of chronic HBV and HCV infection varies widely between European countries. Anti-HCV-Ab screening of PWID and HBsAg screening of pregnant women and migrants have European public health priority. Cost-effectiveness analyses may need to take effect of antiviral treatment on preventing HBV and HCV transmission into account. PMID:23597411

  8. Maternal ABO and rhesus blood group phenotypes and hepatitis B surface antigen carriage.

    PubMed

    Lao, T T; Sahota, D S; Chung, M-K; Cheung, T K W; Cheng, Y K Y; Leung, T Y

    2014-11-01

    In view of a persistently high prevalence of hepatitis B surface antigen (HBsAg) carriage in our obstetric population, we examined the association between HBsAg carriage with maternal ABO and rhesus (Rh) blood group phenotypes determined at routine antenatal screening. In a retrospective study, the antenatal screening results of women booked for confinement between 1998 and 2011 in our hospital were examined for the relationship between HBsAg carriage with the ABO and rhesus blood groups, taking into account also the effects of advanced maternal age (≥ 35 years) and parity status (nulliparous or multiparous), and year of birth before or following the availability of the hepatitis B vaccine (1984). HBsAg carriage was found in 9.9%, 9.6%, 9.1% and 10.2% (P = 0.037) for group-A (n = 20 581 or 26.1%), -B (n = 20 744 or 26.4%), -AB (n = 5138 or 6.5%) and -O (n = 32 242 or 41.0%) among the 78705 women in the study cohort. Rhesus negativity was found in 0.6%, and HBsAg carriage was 12.3% and 9.8%, respectively, for the Rh-negative and Rh-positive women (P = 0.071). Carriage rate between group-O and non-O was influenced by nulliparity, age ≥ 35 years and Rh-positive status. Regression analysis indicated that group-B (P = 0.044, aOR = 1.062, 95% CI 1.002-1.127) and group-AB (P = 0.016, aOR = 1.134, 95% CI 1.024-1.256) were associated with HBsAg carriage. Blood groups-B and -AB are associated with increased hepatitis B virus (HBV) infection in our population, and further studies are warranted to elucidate the implications of this on the sequelae of HBV infection.

  9. Partial analysis of hepatitis B virus DNA from hepatocellular carcinoma showing negative hepatitis B virus surface antigen: an analysis of two Japanese cases.

    PubMed

    Shiota, Goshi; Oyama, Kenji; Udagawa, Akihide; Nomi, Takahiro; Tanaka, Kiwamu; Tsutsumi, Atsushi; Noguchi, Noya; Okano, Jun-ichi; Kishimoto, Yosuke; Kanbe, Takamasa; Kishimoto, Hiroyuki; Kawasaki, Hironaka

    2009-01-01

    It has been reported that hepatitis B virus (HBV) DNA is detected in serum and/or liver in patients with hepatocellular carcinoma (HCC) without HBsAg. To adress this issue, we analyzed HBV genome in 2 HCC cases without HBsAg. The DNA from serum from patients with HCC was amplified with a nested PCR, and 'a' determinant of S region, core promoter region and precore region were sequenced. The first case, a 50 years-old male, was negative for HBsAg and HBeAg, and positive for anti-HBs, anti-HBe and anti-HBc. Viral load of HBV in serum was 4.0 log genome equivalent/ml by TMA assay, and was 1.1 X 105 copy/ml by real-time PCR system. A nucleotide analysis of the common 'a' determinant of S gene showed that the 5 first amino acids of 'a' determinant, CTIPA, were changed to CKTCTTPA. The second case, a 76 years-old male, was positive for anti-HBe, but negative for HBsAg, anti-HBs, HBeAg and anti-HBc. No missense or nonsense mutations were seen in 'a' determinant of S region. Viral load of serum HBV was < 3.7 log genome equivalent/ml by TMA assay, but was 2.4X103 copy/ml by real-time PCR system. The results of the present study suggest that the mechanisms of HBsAg loss are diverse among HCC patients without HBsAg, and that an analysis of HBV genome is a useful tool to dissolve molecular mechanisms losing HBs antigenicity. PMID:19950820

  10. Hepatitis delta virus: protein composition of delta antigen and its hepatitis B virus-derived envelope.

    PubMed Central

    Bonino, F; Heermann, K H; Rizzetto, M; Gerlich, W H

    1986-01-01

    Hepatitis delta virus (HDV)-associated particles were purified from the serum of an experimentally infected chimpanzee by size chromatography and by density centrifugation. Hepatitis delta antigen (HDAg) was detected after mild detergent treatment at a column elution volume corresponding to 36-nm particles and banded at a density of 1.25 g/ml. The serum had an estimated titer of 10(9) to 10(10) HDV-associated particles and had only a 10-fold excess of hepatitis B surface antigen (HBsAg) not associated with HDAg. Therefore, HDV appears to be much more efficiently packed and secreted than is its helper virus, hepatitis B virus (HBV), which is usually accompanied by a 1,000-fold excess of HBsAg. The protein compositions of the HDAg-containing particles were analyzed by immunoblotting with HDAg-, HBsAg-, and hepatitis B core antigen-specific antisera and monoclonal antibodies to HBV surface gene products. The HBsAg envelope of HDAg contained approximately 95% P24/GP27s, 5% GP33/36s, and 1% P39/GP42s proteins. This protein composition was more similar to that of the 22-nm particles of HBsAg than to that of complete HBV. The significant amount of GP33/36s suggests that the HBsAg component of the HDV-associated particle carries the albumin receptor. Two proteins of 27 and 29 kilodaltons which specifically bound antibody to HDAg but not HBV-specific antibodies were detected in the interior of the 36-nm particle. Since these proteins were structural components of HDAg and were most likely coded for by HDV, they were designated P27d and P29d. Images PMID:3701932

  11. Chronic Hepatitis D; at a Standstill?

    PubMed

    Rizzetto, Mario

    2016-01-01

    Chronic hepatitis D (CHD) is a severe liver disease with worldwide distribution caused by the hepatitis D virus (HDV). Therapy of CHD is at a standstill. It still relies on interferon (IFN), introduced empirically in the 1980s; results are limited. With the peghilated IFNs that are now in use, only 25% of CHD reach a sustained viral response, that is, clear the HDV-RNA 6 months after stopping therapy. However, HDV remains infectious and ready to reactivate at very low titers undetectable by current assays, if the HBsAg persists in serum; relapses of hepatitis D post-therapy are frequent and further diminish the therapeutic response. The major obstacle to CHD therapy is the minimalist nature of the HDV. It does not encode for any enzymatic function but is replicated by host RNA polymerases deceived to recognize the viral RNA as it were a cellular DNA; therefore, it has no replicative machinery of its own to be targeted by antivirals. The only help required from hepatitis B virus (HBV) is the HBsAg coat to attach to hepatocytes and assembly in the virion; HBV antivirals that decrease HBV-DNA but leave HBsAg unaffected are of no avail in CHD. Novel therapeutic strategies are under evaluation. Myrcludex B, a peptidic inhibitor of HBV entry, was used with some success in vitro in the mouse to block the Na+-tauro chocolate cotransporting polypeptide and prevent entry of the HD virion into hepatocytes. The nuclei acid polymer REP-2139 was shown to distinctly diminish serum HBsAg and HDV-RNA by blocking HBsAg entry and inhibiting its intracellular synthesis. Prenylation of the large HD-antigen is critical for its interaction with the HBsAg in the assembly of the virion. A proof of concept study in humans has shown that the prenylation inhibitor lonafarnib reduced HDV-viremia. PMID:27170382

  12. Seroepidemiology and occult hepatitis B virus infection in young adults in Banjarmasin, Indonesia.

    PubMed

    Darmawan, Erica; Turyadi; El-Khobar, Korri E; Nursanty, Ni Ketut Dias; Thedja, Meta D; Muljono, David Handojo

    2015-02-01

    Hepatitis B virus (HBV) infection remains a public health problem in Indonesia. There has been limited data regarding HBV infection in young adult population. This study aimed to evaluate the seroepidemiology of HBV infection and characterize occult HBV variants in healthy young adults in Banjarmasin, Indonesia, who were born before the implementation of the universal infant hepatitis B vaccination. Serum samples of 195 healthy young adults were tested for HBsAg, anti-HBc, and anti-HBs. The prevalence of HBsAg, anti-HBc, and anti-HBs was 9 (4.6%), 62 (31.8%), and 96 (49.2%), respectively. Seventy four (37.9%) samples were seronegative for all three parameters, indicating the susceptibility to HBV infection. Among 66 samples positive for HBsAg and/or anti-HBc, 13 (19.7%) were HBV DNA positive; of these, four were HBsAg positive and nine were HBsAg negative, and categorized as occult HBV infection. Most occult HBV cases had high-level anti-HBs (>100 IU/l), suggesting that blood with positive anti-HBs and anti-HBc could not be regarded as noninfectious. Thirteen amino acid substitutions were identified: T126S, P127S, Q129R, T131N, M133T, and Y161S in the HBsAg-positive group; P120T, T126I, G145S, Y161F, E164V, and V168F in the occult-HBV group; and T143S in both groups. More studies are required to provide data on the prevalence and characteristics of mutants to ensure reliable diagnosis. The occult HBV infection, combined with the HBsAg prevalence, could indicate the high HBV carriage among young adults in this area. The high percentage of individuals susceptible to HBV infection reiterates the need for catch-up immunization strategies targeted at young adults.

  13. Induction of endoplasmic reticulum-derived oxidative stress by an occult infection related S surface antigen variant

    PubMed Central

    Lee, In-Kyung; Lee, Seoung-Ae; Kim, Hong; Won, You-Sub; Kim, Bum-Joon

    2015-01-01

    AIM: To investigate the mechanism of endoplasmic reticulum (ER) stress induction by an occult infection related hepatitis B virus S surface antigen (HBsAg) variant. METHODS: We used an HBsAg variant with lower secretion capacity, which was a KD variant from a Korean subject who was occultly infected with the genotype C. We compared the expression profiles of ER stress-related proteins between HuH-7 cells transfected with HBsAg plasmids of a wild-type and a KD variant using Western blot. RESULTS: Confocal microscopy indicated that the KD variant had higher levels of co-localization with ER than the wild-type HBsAg. The KD variant up-regulated ER stress-related proteins and induced reactive oxygen species (ROS) compared to the wild-type via an increase in calcium. The KD variant also down-regulated anti-oxidant proteins (HO-1, catalase and SOD) compared to the wild-type, which indicates positive amplification loops of the ER-ROS axis. The KD variant also induced apoptotic cell death via the up-regulation of caspase proteins (caspase 6, 9 and 12). Furthermore, the KD variant induced a higher level of nitric oxide than wild-type HBsAg via the up-regulation of the iNOS protein. CONCLUSION: Our data indicate that occult infection related HBsAg variants can lead to ER-derived oxidative stress and liver cell death in HuH-7 cells. PMID:26078563

  14. Immunogenicity and safety of Advax™, a novel polysaccharide adjuvant based on delta inulin, when formulated with hepatitis B surface antigen: a randomized controlled Phase 1 study.

    PubMed

    Gordon, David; Kelley, Peter; Heinzel, Susanne; Cooper, Peter; Petrovsky, Nikolai

    2014-11-12

    There is a need for additional safe and effective human vaccine adjuvants. Advax™ is a novel adjuvant produced from semi-crystalline particles of delta inulin. In animal studies Advax enhanced humoral and cellular immunity to hepatitis B surface antigen (HBsAg) without inducing local or systemic reactogenicity. This first-in-man Phase 1 clinical trial tested the safety and tolerability of three intramuscular doses of HBsAg formulated with Advax in a group of healthy adult subjects. Advax was well tolerated with injection site pain scores not significantly different to subjects receiving HBsAg alone and no adverse events were reported in subjects that received Advax. Seroprotection and HBsAb geometric mean titers (GMT) after three immunizations were higher in the Advax 5mg (seroprotection 5/6, 83.3%, GMT 40.7, 95% CI 11.9-139.1) and 10mg (seroprotection 4/5, 80%, GMT 51.6, 95% CI 10.0-266.2) groups versus HBsAg alone (seroprotection 1/5, 20%, GMT 4.1, 95% CI 1.3-12.8). Similarly the proportion of subjects with positive CD4 T-cell responses to HBsAg was higher in the Advax 5mg (4/6, 67%) and Advax 10mg (4/5, 80%) groups versus HBsAg alone (1/5, 20%). These results confirm the safety, tolerability and immunogenicity of Advax adjuvant observed in preclinical studies. Advax may represent a suitable replacement for alum adjuvants in prophylactic human vaccines subject to confirmation of current results in larger studies. Australia and New Zealand Clinical Trial Registry: ACTRN12607000598482.

  15. A Retrospective Study on the Significance of Liver Biopsy and Hepatitis B Surface Antigen in Chronic Hepatitis B Infection

    PubMed Central

    Zeng, Da-Wu; Zhang, Jie-Min; Liu, Yu-Rui; Dong, Jing; Jiang, Jia-Ji; Zhu, Yue-Yong

    2016-01-01

    Abstract To investigate changes in the HBV replication level along with the natural course of chronic HBV infection and to examine the accuracy of the immune tolerant phase defined by the serological profile. A total of 390 chronic HBV-infected patients were retrospectively recruited for this study. They were classified into immune-tolerance (IT), immune-clearance (IC), low-replicative (LR), and HBeAg-negative hepatitis (ENH) phases according to serological profiles (single-standard, SS) or dual-standard (DS) with the inclusion of liver histology. Serum HBV DNA and HBsAg were quantitatively measured, and liver histology was quantitatively analyzed. The accuracy of the SS-defined IT phase was low, and active pathological changes were detected in 56 of 112 SS-defined IT patients. DS-defined IT patients had higher HBsAg levels (P = 0.0002) than the SS-defined patients. The quantitative HBsAg level can help identify SS-defined IT patients with potential liver injury. The area under the received operating characteristic curve for predicting the DS-defined IT phase was 0.831 (HBsAg 4.398 log IU/mL; sensitivity 87.5%; specificity 73.2%). HBV DNA was reduced by 4 logs, whereas HBsAg was only decreased by 2 logs with HBeAg positive to negative phase conversion. Approximately half of IT patients defined by SS may have medium or severe liver injury. Quantitative measurement of the HBsAg level can help identify SS-defined IT patients with potential liver injury. PMID:26937895

  16. Unique immunogenicity of hepatitis B virus DNA vaccine presented by live-attenuated Salmonella typhimurium.

    PubMed

    Woo, P C; Wong, L P; Zheng, B J; Yuen, K Y

    2001-04-01

    A novel vaccine for hepatitis B virus (HBV) was designed by putting a naked DNA vaccine carrying hepatitis B surface antigen (HBsAg) into live-attenuated Salmonella typhimurium. Mucosal immunization by the oral route in mice showed significantly stronger cytotoxic T lymphocyte (CTL) response than recombinant HBsAg vaccination (P < 0.01 at an effector:target ratio of 100:1), while comparable to intramuscular naked DNA immunization at all effector:target ratios. Contrary to previous reports on naked DNA vaccines given intramuscularly, the IgG antibody response induced by the mucosal DNA vaccine is relatively weak when compared to recombinant HBsAg vaccine (P < 0.001 at day 21). These findings are supported by a high interferon-gamma but a low interleukin-4 level detected in the supernatant of splenic cell cultures obtained from mucosally immunized mice. As distinct to recombinant HBsAg vaccine which is effective for protection, oral mucosal DNA vaccine should be considered as a candidate for therapeutic immunization in chronic HBV infection, donor immunization before adoptive transfer of HBV-specific CTL to HBsAg positive bone marrow transplant recipients, and immunization of non-responders to recombinant HBsAg vaccine. This strongly cellular and relatively absent humoral response may make this vaccine a better candidate as a therapeutic vaccine for chronic HBV carriers than naked DNA vaccines, as the humoral response is relatively less important for the clearance of HBV from hepatocytes, but its presence may lead to side effects such as serum sickness and immune complex deposition in chronic HBV carriers.

  17. Serologic indices of hepatitis B virus infection in military recruits in Greece (2004–2005)

    PubMed Central

    German, Vasilios; Giannakos, Georgios; Kopterides, Petros; Liaskonis, Konstantinos; Falagas, Matthew E

    2006-01-01

    Background The prevalence of hepatitis B virus infection in Greece has been decreasing over the last decades. However, recent epidemiological data are lacking. Methods We studied 1,840 Army recruits from 05/2004 until 10/2005, and performed serological testing for HBsAg, anti-HBsAg, and anti-HBcAg. We also examined their association with several factors, including age, residential area, socioeconomic class, and educational level. Results Mean age (± SD) of the recruits was 20.5 (± 2.1) years. Antibodies to HBV core antigen [anti-HBcAg (+)] were found in 31 (1.68%) of 1,840 participants. Only 6 (0.32%) were HBsAg (+)/anti-HBsAg (-)/anti-HBcAg (+), while 21 (1.14%) were HBsAg (-)/anti-HBsAg (+)/anti-HBcAg (+), and 4 (0.22%) were HBsAg (-)/anti-HBsAg (-)/anti-HBcAg (+). Overall, 1,144 recruits (62.17%) had antibodies against HBsAg [HBsAg (-)/anti-HBsAg (+)/anti-HBcAg (-)]; 665 recruits (36.14%) had undetectable anti-HBsAg levels. Multivariable analysis showed that younger age (OR: 0.87; 95% CI: 0.82–0.92) and advanced educational level (OR: 1.59; 95% CI: 1.32–1.93) were independently associated with serologic evidence suggestive of previous HBV vaccination. Conclusion We document a further decline of the prevalence of chronic HBV infection among Greek military recruits, a fact that may support the effectiveness of the ongoing immunization programme. PMID:17105648

  18. Preparation and characterization of human monoclonal antibodies directed against the hepatitis B virus surface antigen.

    PubMed

    Colucci, G; Kohtz, D S; Waksal, S D

    1986-06-01

    The hepatitis B surface antigen (HBsAg) is highly immunogenic and induces an antibody response which is protective in vivo against hepatitis B virus (HBV) infection. Human monoclonal antibodies specific for HBsAg were produced, which could have potential therapeutic applications. Lymphocytes obtained from a vaccinated donor were stimulated in vitro and fused with the human myeloma cell line GM 4672, and eight hybridomas were obtained. Three of these clones, which reacted in an ELISA against the HBsAg vaccine, were expanded, subcloned and further analyzed. The subclones E7C2, C4C10, and D5B2 were able to bind to different HBsAg preparations, which express various subtypes, and recognized the major HBsAg peptides in Western blot analysis. Cross-inhibition experiments showed that E7C2, C4C10 and D5B2 are directed against the same epitope and have an affinity constant ranging from 5 X 10(7) to 3.3 X 10(9) M. Furthermore, these antibodies stained the surface and cytoplasm of the HBsAg-secreting cell lines PLC/PRF/5 and 4.10. The production of immunoglobulins varies from 0.3 to 1.3 micrograms/ml/10(6) and has remained stable over a period of 8 months. These human monoclonal antibodies, which appear to be directed against an antigenic determinant common to all HBsAg subtypes, could be useful in the study of HBV-related liver diseases as well as in their diagnosis and experimental therapy.

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

    NASA Astrophysics Data System (ADS)

    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

  20. Potential for laboratory exposures to biohazardous agents found in blood.

    PubMed Central

    Evans, M R; Henderson, D K; Bennett, J E

    1990-01-01

    The magnitude of risk for occupational exposures to biohazardous agents found in blood was assessed by 800 environmental samples taken from a total of 10 clinical and research laboratories at the National Institutes of Health (NIH). Thirty-one samples from 11 work stations in three laboratories contained hepatitis B virus surface antigen (HBsAg). Observations of workers indicated that environmental contamination arose from several sources. Among the 11 work stations with HBsAg environmental samples, eight had high work loads, seven had inappropriate behaviors, and nine had flawed laboratory techniques. This information suggests that a multifactorial approach is needed to minimize the risk of laboratory-associated infections. PMID:2316762

  1. Prevalence of Serologic Hepatitis B Markers in Blood Donors From Puebla, Mexico: The Association of Relatively High Levels of Anti-Core Antibodies With the Detection of Surface Antigen and Genomic DNA

    PubMed Central

    Sosa-Jurado, Francisca; Hilda Rosas-Murrieta, Nora; Guzman-Flores, Belinda; Perez Zempoaltecalt, Cintia; Patricia Sanchez Torres, Ana; Ramirez Rosete, Leticia; Bernal-Soto, Maribel; Marquez-Dominguez, Luis; Melendez-Mena, Daniel; Angel Mendoza Torres, Miguel; Teresa Lopez Delgado, Maria; Reyes-Leyva, Julio; Vallejo-Ruiz, Veronica; Santos-Lopez, Gerardo

    2016-01-01

    Background The hepatitis B virus (HBV) causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg) detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc) suggests either a previous or ongoing infection or occult hepatitis B infection (OBI). Objectives The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the “a” determinant associated with the non-detection of HBsAg in serum. Patients and Methods We conducted a cross-sectional study from 2003–2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA) or chemiluminescent (CMIA)) were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR) was used and the genotypes were determined using Sanger sequencing. Results Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26) were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079) were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1). Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some “a” determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays. Conclusions We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing positive

  2. Prevalence of Serologic Hepatitis B Markers in Blood Donors From Puebla, Mexico: The Association of Relatively High Levels of Anti-Core Antibodies With the Detection of Surface Antigen and Genomic DNA

    PubMed Central

    Sosa-Jurado, Francisca; Hilda Rosas-Murrieta, Nora; Guzman-Flores, Belinda; Perez Zempoaltecalt, Cintia; Patricia Sanchez Torres, Ana; Ramirez Rosete, Leticia; Bernal-Soto, Maribel; Marquez-Dominguez, Luis; Melendez-Mena, Daniel; Angel Mendoza Torres, Miguel; Teresa Lopez Delgado, Maria; Reyes-Leyva, Julio; Vallejo-Ruiz, Veronica; Santos-Lopez, Gerardo

    2016-01-01

    Background The hepatitis B virus (HBV) causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg) detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc) suggests either a previous or ongoing infection or occult hepatitis B infection (OBI). Objectives The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the “a” determinant associated with the non-detection of HBsAg in serum. Patients and Methods We conducted a cross-sectional study from 2003–2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA) or chemiluminescent (CMIA)) were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR) was used and the genotypes were determined using Sanger sequencing. Results Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26) were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079) were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1). Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some “a” determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays. Conclusions We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing positive

  3. Response to antiretroviral therapy in occult hepatitis B and HIV co-infection in West Africa.

    PubMed

    Chadwick, David; Stanley, Alastair; Sarfo, Stephen; Appiah, Lambert; Ankcorn, Michael; Foster, Geraldine; Schwab, Uli; Phillips, Richard; Geretti, Anna M

    2013-01-01

    This study evaluated the outcome of first-line antiretroviral therapy among 35 Ghanaians with occult HBV/HIV co-infection, comparing them over 2 years to 120 patients with HBsAg+ HBV/HIV co-infection and 230 patients without HBV co-infection. Increases in CD4 cell count and BMI were similar, whereas elevations of hepatic transaminases were more frequent in both the occult HBV and HBsAg+ patients. Occult HBV/HIV co-infection appears not to impact adversely on response to antiretroviral therapy in Ghana. PMID:22874516

  4. Practical guidelines for assessing patients positive for hepatitis B surface antigen.

    PubMed Central

    Feinman, S. V.; Berris, B.; Sinclair, J. C.; Wrobel, D. W.

    1976-01-01

    In assessing the patient the hepatitis B surface antigen (HBsAg) the physician must decide on the basis of physical findings, results of laboratory tests and biopsy, when indicated, whether the patient is an asymptomatic carrier or has acute or chronic hepatitis. Asymptomatic carriers of HBsAg must be educated in personal hygiene and the possibility of transmission, should not be allowed to donate blood or breast-feed and should not work with blood products for human use or pharmaceutical products designated for intravenous use. However, it is otherwise not necessary to advise these individuals to change their profession. PMID:1032589

  5. NXY 059: CPI 22, NXY 059G.

    PubMed

    2003-01-01

    NXY 059 [CPI 22, NXY 059G], a nitrone with free radical trapping properties, has potential in the treatment of ischaemic stroke.This profile has been selected from R&D Insight, a pharmaceutical intelligence database produced by Adis International Ltd. NXY 059 is based on Centaur Pharmaceuticals' proprietary Nitrone-Related Therapeutics (NRT) technology. A generic form of NXY 059, NXY 059G, has been synthesised. On 12 December 2002, Centaur Pharmaceuticals was acquired by, and integrated into, Renovis. AstraZeneca has exclusive worldwide rights to NXY 059, under a licence from Centaur Pharmaceuticals; the licensing agreement is continuing with Renovis. Renovis will receive a significant milestone payment and retains a co-promotion option for NXY 059 in the US. In addition, Renovis is entitled to royalties on profits from worldwide sales of the drug once commercialised. Centaur received a cash payment of $US1.25 million, and up to 30% of Renovis stock in exchange for these assets. In May 2003, AstraZeneca announced the initiation of two major phase III pivotal clinical trials to determine the effect of NXY 059 on disability and neurological recovery in acute ischemic stroke patients. The trials, known as the SAINT (Stroke-Acute-Ischaemic-NXY-Treatment) trials, will compare the efficacy and safety of a 72-hour intravenous infusion of NXY 059 given within 6 hours of the onset of symptoms vs placebo. The studies will enrol >3000 patients. The SAINT I trial will involve 200 centres across 24 countries in Europe, Asia, Australia and South Africa. The SAINT II trial will involve patients from approximately 150 sites in the US, Canada and South America. AstraZeneca is evaluating NXY 059 in a phase I clinical study in the US. Phase III trials of NXY 059 have begun in the UK and Sweden for the treatment of stroke. In November 2000, Centaur Pharmaceuticals announced that the Japanese regulatory authorities approved AstraZeneca's regulatory filings for phase I clinical studies

  6. The first known Uranian Trojan and the frequency of temporary giant-planet co-orbitals

    NASA Astrophysics Data System (ADS)

    Greenstreet, Sarah; Alexandersen, M.; Gladman, B.; Kavelaars, J.; Petit, J.; Gwyn, S.

    2013-10-01

    We report the first discovery of a Uranian Trojan (2011 QF99) in 2011-2012 CFHT Megacam imaging taken for a 20 square degree outer Solar System survey designed to detect and track Trans-Neptunian Objects and Centaurs. The orbit of the newly discovered object was constrained with 29 astrometric measurements over 7 dark runs with a total arc of 419 days. Numerical integrations of both the nominal orbit and all other orbits within the (already small) orbital uncertainties show 2011 QF99 oscillates around the L4 Lagrange point 60 degrees ahead of Uranus for >70 kyr and remains co-orbital (in 1:1 resonance) for ~1 Myr before becoming a Centaur. We performed additional orbital integrations to investigate the possibility the object could have evolved to its current orbit from a nearby, stable niche of phase-space. However, test particles started on orbits in the small region of phase-space surrounding the nominal orbit remained co-orbital for <100 Myr, most for <10 Myr. This leads to the conclusion that 2011 QF99 must be a temporary co-orbital instead of being a primordial Trojan. To investigate the frequency and duration (to factor of two accuracy) of temporary co-orbital captures with Uranus and Neptune, we construct a model of Centaurs supplied from the transneptunian region over 1 Gyr, building a relative orbital distribution for the a<34 AU region. The simulation output interval of 300 yr for the planets and all a<34 AU particles allows the 1:1 resonant argument to be well sampled; to our knowledge, this is the first time such a meticulous search for short-term co-orbitals of giant planets has been performed for an armada of incoming scattering objects. Analysis of the particle histories showed that at any given time, significant fractions (0.4% and 2.8%) of the a<34 AU Centaur population will be Uranian and Neptunian co-orbitals, respectively. We show for the first time that the high fraction 3%) of the transient co-orbital Centaurs in the IAU Minor Planet Center

  7. Chitosan and Sodium Alginate Combinations Are Alternative, Efficient, and Safe Natural Adjuvant Systems for Hepatitis B Vaccine in Mouse Model

    PubMed Central

    AbdelAllah, Nourhan H.; Boseila, Abeer A.; Amin, Magdy A.

    2016-01-01

    Hepatitis B viral (HBV) infections represent major public health problem and are an occupational hazard for healthcare workers. Current alum-adjuvanted HBV vaccine is the most effective measure to prevent HBV infection. However, the vaccine has some limitations including poor response in some vaccinee and being a frost-sensitive suspension. The goal of our study was to use an alternative natural adjuvant system strongly immunogenic allowing for a reduction in dose and cost. We tested HBV surface antigen (HBsAg) adjuvanted with chitosan (Ch) and sodium alginate (S), both natural adjuvants, either alone or combined with alum in mouse model. Mice groups were immunized subcutaneously with HBsAg adjuvanted with Ch or S, or triple adjuvant formula with alum (Al), Ch, and S, or double formulations with AlCh or AlS. These were compared to control groups immunized with current vaccine formula or unadjuvanted HBsAg. We evaluated the rate of seroconversion, serum HBsAg antibody, IL-4, and IFN-γ levels. The results showed that the solution formula with Ch or S exhibited comparable immunogenic responses to Al-adjuvanted suspension. The AlChS gave significantly higher immunogenic response compared to controls. Collectively, our results indicated that Ch and S are effective HBV adjuvants offering natural alternatives, potentially reducing dose. PMID:27493674

  8. Frequency and significance of antibodies against hepatitis B core (anti-HBc) antigen as the only serological marker for hepatitis B infection in Lebanese blood donors.

    PubMed Central

    Ramia, S.; Ramlawi, F.; Kanaan, M.; Klayme, S.; Naman, R.

    2005-01-01

    During a 2-year period, blood samples from 2505 Lebanese blood donors were chosen at random, at various periods of time at one blood donation centre (Hotel Dieu de France, Beirut, Lebanon) and were screened for markers of HBV infection (HBsAg, anti-HBc and anti-HBs). The study showed HBsAg positivity of 0.6% and an overall exposure rate to HBV of 10.0%. Out of the 2505 blood donors screened, 56 (22%) were found to be 'anti-HBc alone' positive which is almost four times the HBsAg positivity. The 56 'anti-HBc alone' samples were retested by another ELISA kit commercially available and 54 samples were 'anti-HBc alone' positive by both assays. The 54 samples had no serological markers as evidence of infection with human immunodeficiency virus (HIV) or hepatitis C virus (HCV). Only seven (13%) out of the 54 samples were HBV DNA positive by PCR and all were HBV genotype D. All seven HBV DNA-positive samples had HBV DNA levels below 400 copies/ml. Although any circulating HBV DNA among our 'anti-HBc alone' blood donors was below the detection limit of our Amplicor Monitor assay, some of these samples had circulating virus. A national study, where a larger number of blood donors from different blood donation centres across the country will perhaps determine whether screening for anti-HBc in addition to HBsAg detection is needed in Lebanese blood donors. PMID:16050516

  9. [Comparison of adsorbent with varying arm length and ligand density for the purification of recombinant hepatitis B virus surface antigen].

    PubMed

    Li, Rui-Hong; Li, Yan; Bi, Jing-Xiu; Zhao, Lan; Zhou, Wei-Bin; Huang, Yong-Dong; Zhang, Yan; Sun, Li-Jing; Wang, Hua-Jun; Su, Zhi-Guo

    2007-07-01

    Novel hydrophobic absorbents were synthesized by immobilizing butyl derivative onto the highly cross-linked agarose beads manufatured in China, which are used as matrix. The effect of the spacer arm length (3C, 8C and 10C) and ligand density (from 13 to 45 micromol/mL) on the hydrophobicity were investigated using purified Hepatitis B surface antigen (HBsAg) expressed by CHO cell lines. Also considering the effects of salt concentration and pH on HBsAg recovery and purification factor, orthogonal experiment design method was used to evaluated the absorbents. The results showed the butyl-S absorbent with the spacer arm length of C8, the ligand density of 22 micromol/mL gel showed the best performance for the separation of HBsAg. Approximately 100% HBsAg recovery and 60 as purification fold were achieved by this media under the operating condition of pH 7.0 and 9% of salt concentrateion.

  10. Hepatitis C and B virus infections in populations at low or high risk in Ho Chi Minh and Hanoi, Vietnam.

    PubMed

    Nakata, S; Song, P; Duc, D D; Nguyen, X Q; Murata, K; Tsuda, F; Okamoto, H

    1994-01-01

    Inhabitants and patients of two cities in Vietnam were tested for antibodies to hepatitis C virus (anti-HCV), hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs). Anti-HCV was detected in 43 (9%) of 491 individuals without liver disease in Ho Chi Minh, more frequently (P < 0.001) than in 18 (4%) of 511 in Hanoi. There was no apparent age-specific distribution of anti-HCV. Among inhabitants of both cities, HBsAg and anti-HBs were frequent, detected in 10-14% and 35-37%, respectively; the prevalence of anti-HBs increased in parallel with age. Among individuals at high risk, the prevalence of anti-HCV was particularly high in drug users (58/67 or 87%) and patients on maintenance haemodialysis (15/28 or 54%) or with haemophilia (7/24 or 29%) in Ho Chi Minh, and in drug users in Hanoi (61/200 or 31%). Prevalence of HBsAg and anti-HBs in high-risk groups was not different from those in the general population. Screening of anti-HCV in blood donors in Vietnam is of urgent necessity because blood supply is dependent on commercial blood donors, many of whom are drug users at high risk.

  11. Chitosan and Sodium Alginate Combinations Are Alternative, Efficient, and Safe Natural Adjuvant Systems for Hepatitis B Vaccine in Mouse Model.

    PubMed

    AbdelAllah, Nourhan H; Abdeltawab, Nourtan F; Boseila, Abeer A; Amin, Magdy A

    2016-01-01

    Hepatitis B viral (HBV) infections represent major public health problem and are an occupational hazard for healthcare workers. Current alum-adjuvanted HBV vaccine is the most effective measure to prevent HBV infection. However, the vaccine has some limitations including poor response in some vaccinee and being a frost-sensitive suspension. The goal of our study was to use an alternative natural adjuvant system strongly immunogenic allowing for a reduction in dose and cost. We tested HBV surface antigen (HBsAg) adjuvanted with chitosan (Ch) and sodium alginate (S), both natural adjuvants, either alone or combined with alum in mouse model. Mice groups were immunized subcutaneously with HBsAg adjuvanted with Ch or S, or triple adjuvant formula with alum (Al), Ch, and S, or double formulations with AlCh or AlS. These were compared to control groups immunized with current vaccine formula or unadjuvanted HBsAg. We evaluated the rate of seroconversion, serum HBsAg antibody, IL-4, and IFN-γ levels. The results showed that the solution formula with Ch or S exhibited comparable immunogenic responses to Al-adjuvanted suspension. The AlChS gave significantly higher immunogenic response compared to controls. Collectively, our results indicated that Ch and S are effective HBV adjuvants offering natural alternatives, potentially reducing dose. PMID:27493674

  12. Delta hepatitis agent: structural and antigenic properties of the delta-associated particle.

    PubMed Central

    Bonino, F; Hoyer, B; Shih, J W; Rizzetto, M; Purcell, R H; Gerin, J L

    1984-01-01

    Delta agent (delta) was serially passaged to a second and third hepatitis B surface antigen (HBsAg) carrier chimpanzee, using as inoculum the peak delta antigen (delta Ag) serum of an animal previously infected with human serum. The characteristics of serially transmitted delta Ag were similar to those described in first-passage animals. It was consistently detected before the development of anti-delta, in association with a 35- to 37-nm subpopulation of HBsAg particles and a unique low-molecular-weight (5.5 X 10(5)) RNA. RNase susceptibility of the delta-associated RNA and release of delta Ag activity upon treatment of delta-associated particles with detergent revealed that this particle is organized into a virion-like form with the RNA and delta Ag as internal components within a coat of HBsAg. Surface determinants of the delta-associated particle other than HBsAg were not detected by radioimmunoprecipitation experiments, using sera of humans and chimpanzees convalescent from delta hepatitis. The HBsAg-associated particle is the "candidate agent" of delta hepatitis. Images PMID:6698598

  13. Limited Genetic Diversity of Hepatitis B Virus in the General Population of the Offin River Valley in Ghana

    PubMed Central

    Ampah, Kobina Assan; Pinho-Nascimento, Carlos Augusto; Kerber, Sarah; Asare, Prince; De-Graft, Daniel; Adu-Nti, Frank; Paixão, Izabel C. N. P.; Niel, Christian; Yeboah-Manu, Dorothy; Pluschke, Gerd; Röltgen, Katharina

    2016-01-01

    Hepatitis B virus (HBV) infections account for approximately 780,000 deaths per year, most of which occur in the developing world. Co-infection with HBV and hepatitis delta virus (HDV) may lead to the most severe form of viral hepatitis. In Ghana, knowledge on the prevalence of HBV and HDV in the general population is scanty and the few genetic analyses of the prevailing HBV genotypes are dating back more than a decade. In the present study, 1,323 serum samples from individuals living in a rural area (Offin river valley) of Ghana were analyzed for the presence of the hepatitis B surface antigen (HBsAg). Positive sera were subsequently tested for the presence of anti-HDV antibodies. A total of 107 (8%) sera were HBsAg positive with an 8.4% prevalence of anti-HDV antibodies among the HBsAg positives. Phylogenetic analysis based on HBV pre-S/S sequences, attributed all 52 typable samples to genotype E. All belonged to serotype ayw4. While 19 sequences clustered with those from a number of African countries, the other 33 formed a separate cluster distinguished by an intergroup mean distance of 1.5% from the pan-African HBV/E cluster. Successful implementation of HBV vaccination in the region was reflected by the low HBsAg carrier rate of 1.8% among children ≤11 years. PMID:27271290

  14. Clinically important immunological processes in acute and fulminant hepatitis, mainly due to hepatitis B virus.

    PubMed Central

    Mackenjee, M K; Kiepiela, P; Cooper, R; Coovadia, H M

    1982-01-01

    Clinically useful criteria were found by studying immunological functions on admission in 15 African children with acute hepatitis (AH) (11 of whom were HBsAg positive) and in 11 children with fulminant hepatic failure (FHF) (8 of whom were HBsAg positive), and by comparing these results with normal controls. Nine of the FHF patients died. All the AH patients survived despite the development of transient liver failure in seven. There was significant diminution of components of the classical and alternative pathways of complement and total haemolytic complement in FHF compared with AH, and in both groups in comparison with controls. Cellular immunity tested by phytohaemagglutinin and HBsAg transformation of lymphocytes and leucocyte migration inhibition with HBsAg, were more impaired in FHF than AH. These indices were reduced in both groups of patients compared with controls. The most important index correlating with severity of clinical disease was C3. It was lowest in FHF, but within this group was highest in 2 patients who survived, and in AH the C3 on admission was significantly lower in patients who subsequently showed signs of transient liver failure than in those who did not. The prothrombin index was less sensitive in differentiating serious from mild illness. It is suggested that C3 levels can be helpful in monitoring patients with acute liver disease. PMID:7082040

  15. Hepatitis B Virus Core Promoter Double Mutations (A1762T, G1764A) Are Associated with Lower Levels of Serum Dihydrolipoyl Dehydrogenase

    PubMed Central

    Jiang, Zhi-Hua; Chen, Qin-Yan; Harrison, Tim J.; Li, Guo-Jian; Wang, Xue-Yan; Li, Hai; Hu, Li-Ping; Li, Kai-Wen; Yang, Qing-Li; Tan, Chao; Fang, Zhong-Liao

    2016-01-01

    Objectives The aim of this study was to identify serum proteins with differential concentrations between hepatocellular carcinoma (HCC) patients and HBsAg asymptomatic carriers among individuals infected with hepatitis B virus (HBV) with basal core promoter (BCP) double mutations (A1762T, G1764A). Methods iTRAQ and liquid chromatography-tandem mass spectrometry were used to identify differentially expressed protein, and an ELISA test was used for the validation test. Results The total number of proteins identified was 1,125, of which 239 showed statistically significant differences in their expression. The relative concentrations of serum dihydrolipoyl dehydrogenase (DLD), which showed the most significant correlation with liver diseases and infection, were significantly lower in HCC patients than asymptomatic HBsAg carriers and individuals negative for HBsAg. However, only the difference between HCC patients with BCP double mutations and HBsAg-negative individuals could be confirmed by ELISA. Meanwhile, we found that the concentrations of serum DLD in those infected with HBV with BCP double mutations were significantly lower than in individuals with the wild-type BCP. However, the difference in the concentrations of serum DLD between individuals with wild-type BCP and those negative for HBsAg was not significant. Conclusions HBV with BCP double mutations are associated with lower concentrations of serum DLD. PMID:27303803

  16. Breaking B and T cell tolerance using cationic lipid--DNA complexes (CLDC) as a vaccine adjuvant with hepatitis B virus (HBV) surface antigen in transgenic mice expressing HBV.

    PubMed

    Morrey, John D; Motter, Neil E; Chang, Stella; Fairman, Jeffery

    2011-06-01

    Cationic lipid DNA complexes (CLDC), referred to here as JVRS-100, were evaluated as an adjuvant for hepatitis B surface antigen (HBsAg) for eliciting B and T cell responses in transgenic mice expressing hepatitis B virus (HBV). To confirm the immunogenicity of HBsAg+JVRS-1000, a study was conducted in C57BL/6 mice, the genetic background of the HBV transgenic mice used in the study. HBsAg+JVRS-100 elicited a T cell response and B cell response as evidenced by interferon-gamma (IFN-γ) secretion by re-stimulated splenocytes and anti-HBsAg IgG induction, respectively, whereas, HBsAg only elicited a B cell response. In HBV transgenic mice, HBsAg did not elicit either T or B cell responses, unlike the HBsAg+JVRS-100 that elicited both. Energix-B vaccine did perform better than the HBsAg by eliciting a B cell response in the transgenic mice, but it did not perform as HBsAg+JVRS-100 since it did not elicit a T cell response. The response by HBsAg+JVRS-100 was not sufficient to cause destruction of infected liver cells, but it did suppress HBV DNA non-cytolytically. From these results, JVRS-100 might be considered for further development as an adjuvant for HBV therapeutic vaccines. PMID:21545812

  17. Fibronectin and asialoglyprotein receptor mediate hepatitis B surface antigen binding to the cell surface.

    PubMed

    Yang, Jing; Wang, Feng; Tian, Linlin; Su, Jing; Zhu, Xiangqian; Lin, Li; Ding, Xiaoran; Wang, Xuejun; Wang, Shengqi

    2010-06-01

    Both fibronectin and the asialoglycoprotein receptor (ASGPR) have been identified by some investigators as partners for hepatitis B virus (HBV) envelope proteins. Because fibronectin is a natural ligand for ASGPR, we speculated that HBV might attach to ASGPR expressed on the hepatocyte surface via fibronectin. To test this hypothesis, we first confirmed by co-immunoprecipitation that ASGPR, fibronectin and HBsAg bind to each other in HepG2.2.15 cells, and possible binding domains were identified by GST pull-down. In addition, by measuring binding of HBsAg to cells, we found that ASGPR and fibronectin enhanced the binding capability of HBsAg to HepG2 cells, and even to 293T and CHO cells, which normally do not bind HBV. In conclusion, our findings suggest that both fibronectin and ASGPR mediate HBsAg binding to the cell surface, which provides further evidence for the potential roles of these two proteins in mediating HBV binding to liver cells. PMID:20364278

  18. Low Prevalence of Hepatitis B and C Virus Markers among Children and Adolescents

    PubMed Central

    Villar, Livia Melo; Amado, Luciane Almeida; de Almeida, Adilson José; de Paula, Vanessa Salete; Lewis-Ximenez, Lia Laura; Lampe, Elisabeth

    2014-01-01

    This study aimed to determine the prevalence of HBV and HCV among children and adolescents attending schools and daycare centres in Rio de Janeiro State, located in southern Brazil. Serum samples from 1,217 individuals aged 0 to 18 years were collected from 1999 to 2012 and tested for HBsAg, total anti-HBc, anti-HBs, and anti-HCV by ELISA. Reactive HBsAg and anti-HBc samples were tested for HBV DNA. Reactive anti-HCV samples were tested for HCV RNA and genotyped by RFLP. HBsAg was detected in 1.8% of individuals, and total anti-HBc was detected among 3.6% of individuals. Anti-HBs reactivity was found among 25.3% (322/1,217) of the individuals and increased from 6.28% in the years 1999-2000 to 76.2% in the years 2001–2012 (P < 0.0001). HBV DNA was detected in 18 of 51 individuals who presented with HBsAg or isolated anti-HBc, and nine were considered occult hepatitis B cases. Three individuals were anti-HCV- and HCV RNA-positive: two of them were infected with genotype 1, and the other was infected with genotype 3. Low levels of HBV and HCV markers were observed in children and adolescents. HBV immunity increased during the period of study, indicating that childhood universal HBV vaccination has been effective for controlling HBV infection in Brazil. PMID:25093164

  19. Prevalence of Hepatitis B and C in Donated Blood from the Jazan Region of Saudi Arabia

    PubMed Central

    Mohammed Abdullah, Saleh

    2013-01-01

    Background: Infections caused by the hepatitis B virus (HBV) and the hepatitis C virus (HCV) are global public health problems. The safety of donated blood can be estimated by monitoring the prevalence of viral markers in the donor population. The present study was carried out in the Jazan region to determine the prevalence of HBV and HCV among Saudi blood donors. Methods: Over a period of six years (January 2004 to December 2009), a total of 29 949 blood units were collected from healthy voluntary and replacement native Saudi blood donors. The donated units were serologically screened for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc), and antibody to hepatitis C virus (anti-HCV). These data were then analysed. Results: HBsAg was positive in 3.8% of the blood units that were collected, the blood units with anti–HCV seropositivity had the lowest prevalence (0.41%), and the prevalence of HBsAg was highest in the group that was > 46 years of age. A significant decline in the prevalence of HBV infection has been observed, from 5.6% in 2004 to 2.3% in 2009 (P < 0.001). Conclusion: The present study showed that the prevalence of HBV and HCV was in a significant decline from 2004 to 2009, and the prevalence of HBsAg and anti-HCV significantly increased with age. PMID:23983576

  20. Mucoadhesive glycol chitosan nanoparticles for intranasal delivery of hepatitis B vaccine: enhancement of mucosal and systemic immune response.

    PubMed

    Pawar, Dilip; Jaganathan, K S

    2016-01-01

    In this study, for the first time, glycol chitosan (GC) nanoparticles (NPs) were prepared and evaluated to obtain systemic and mucosal immune responses against nasally administered hepatitis B surface antigen (HBsAg). Size, zeta potential and morphology of the NPs were investigated as a function of preparation method. NPs with high loading efficacy ( > 95%) and positively charged surface were obtained with an average particle size of approximately 200 nm. The structural integrity of HBsAg in NPs was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis and further confirmed by measuring the in vitro antigenicity using an enzyme immunoassay. During in vivo studies, GC NPs showed the lowest nasal clearance rate and better mucosal uptake when compared with chitosan (CS) NPs. The immunogenicity of NPs-based delivery system(s) was assessed by measuring anti-HBsAg antibody titer in mice serum and secretions after intranasal administration. The alum-based HBsAg vaccine injected subcutaneously was used as positive control. Results indicated that alum-based HBsAg induced strong humoral but negligible mucosal immunity. However, GC NPs induced stronger immune response at both of the fronts as compared to generated by CS NPs. This study demonstrates that this newly developed system has potential for mucosal administration of vaccines.

  1. Clinical significance of hepatitis B surface antigen mutants

    PubMed Central

    Coppola, Nicola; Onorato, Lorenzo; Minichini, Carmine; Di Caprio, Giovanni; Starace, Mario; Sagnelli, Caterina; Sagnelli, Evangelista

    2015-01-01

    Hepatitis B virus (HBV) infection is a major public health problem in many countries, with nearly 300 million people worldwide carrying HBV chronic infection and over 1 million deaths per year due to cirrhosis and liver cancer. Several hepatitis B surface antigen (HBsAg) mutations have been described, most frequently due to a single amino acid substitution and seldom to a nucleotide deletion. The majority of mutations are located in the S region, but they have also been found in the pre-S1 and pre-S2 regions. Single amino acid substitutions in the major hydrophilic region of HBsAg, called the “a” determinant, have been associated with immune escape and the consequent failure of HBV vaccination and HBsAg detection, whereas deletions in the pre-S1 or pre-S2 regions have been associated with the development of hepatocellular carcinoma. This review article will focus on the HBsAg mutants and their biological and clinical implications. PMID:26644816

  2. Universal immunization of infants with low doses of a low-cost, plasma-derived hepatitis B vaccine in South Africa.

    PubMed Central

    Schoub, B. D.; Matai, U.; Singh, B.; Blackburn, N. K.; Levin, J. B.

    2002-01-01

    OBJECTIVE: To evaluate the effectiveness of universal vaccination against viral hepatitis B in South Africa among 18-month-old rural children. METHODS: Children were immunized with a course of low-dose (1.5 microg), plasma-derived hepatitis B vaccine at 6, 10 and 14 weeks of age, and blood samples from the children were tested for three hepatitis B markers: hepatitis B surface antigen (HBsAg), anti-HBs and anti-HBc. FINDINGS: One year after vaccination, a protective anti-HBs antibody titre of at least 10 IU/l was present in 669/769 (87.0%) of blood serum samples tested. Only 3/756 children (0.4%) were HBsAg positive and a fourth child was anti-HBc positive (HBsAg negative). This is a marked decrease compared to the hepatitis B prevalences reported in previous studies. Among rural migrant mine-workers, for example, HBsAg prevalence was 9.9%, and was 10.1% among children 0-6 years of age in the Eastern Cape Province. CONCLUSION: The low-dose, plasma-derived hepatitis B vaccine, which is affordable to most developing countries, was very successful in controlling endemic hepatitis B infection, where the virus is predominantly spread by horizontal transmission among infants and young children. PMID:12075363

  3. Hepatitis B virus DNA in blood donors with anti-HBc as a possible indicator of active hepatitis B virus infection in Yucatan, Mexico.

    PubMed

    García-Montalvo, B M; Farfán-Ale, J A; Acosta-Viana, K Y; Puerto-Manzano, F I

    2005-10-01

    Hepatitis B virus (HBV) may be present in serum even when negative for HBV surface antigen (HBsAg). If routine screening of sera for anti-HBV core antigen (anti-HBc) is not done, low-level HBV viraemia may not be identified. A study was done on the presence of HBV DNA in serum samples from Mexican blood donors negative for HBsAg. Sera from 158 volunteer blood donors, negative for HBsAg and anti-HBs, but positive for anti-HBc, were analysed using nested polymerase chain reaction (PCR). HBV DNA was detected in sera from 13 (8.23%) of the 158. Specificity of the PCR-amplified products was corroborated using Southern blot. Single strand conformation polymorphism (SSCP) analysis showed identical SSCP-banding patterns for all 13 PCR products, suggesting similar cDNA sequences. Occult HBV infection was observed in approximately 8% of anti-HBc only donors. The absence of HBsAg in the blood of apparently healthy individuals may not be sufficient to ensure lack of circulating HBV, and blood containing anti-HBc only may be infectious until proven otherwise.

  4. Study of the immunogenicity of hepatitis B surface antigen synthesized in transgenic potato plants with increased biosafety.

    PubMed

    Rukavtsova, Elena B; Rudenko, Natalya V; Puchko, Elena N; Zakharchenko, Natalya S; Buryanov, Yaroslav I

    2015-06-10

    Oral immunogenicity of the hepatitis B surface antigen (HBsAg) synthesized in the tubers of marker-free potato plants has been demonstrated. Experiments were performed in the two groups of outbred NMRI mice. At the beginning of investigations, the mice of experimental group were fed the tubers of transgenic potato synthesizing the HBsAg three times. The mice of control group were fed nontransgenic potato. Intraperitoneal injection of the commercial vaccine against hepatitis B (0.5μg/mouse) was made on day 71 of the experiment. Enzyme-linked immunoassay (ELISA) of the serum of immunized animals showed an increase in the level of HBsAg antibodies significantly above the protective value, which was maintained for 1 year after the immunization. In 1 year, the experimental group of mice underwent additional oral immunization with HBsAg-containing potato tubers. As a result, the level of antibodies against the HBsAg increased and remained at a high protective level for several months. The findings show the possibility of using transgenic plants as a substance for obtaining a safe edible vaccine against hepatitis B. PMID:25840367

  5. Hepatitis B and C status among health care workers in the five main hospitals in eastern Libya.

    PubMed

    Elzouki, Abdel-Nasser; Elgamay, Salwa M; Zorgani, Abdeulaziz; Elahmer, Omer

    2014-01-01

    The aim of the present study was to determine the frequency of hepatitis B and C transmission to health care workers (HCWs) in five major hospitals in eastern Libya and to analyze how the risk of these infections are affected by the type of occupation, hospital work place and working period. From July 2008 to June 2009, 601 HCWs (mean age: 32.90 ± 8.85 years) were tested for HBV and HCV markers using ELISA techniques. Polymerase chain reaction (PCR) was performed on all positive samples of HBsAg and Anti-HCV antibody to determine the level of HBV-DNA and HCV-RNA viremia, respectively. The overall frequency of HBsAg positivity was 1.8%. Anti-HBc, HBeAg and Anti-HBe antibodies were found in 8.5%, 0.7% and 8.0% of samples, respectively. The HBV-DNA level was positive in 55% of all HBsAg-positive samples. Approximately half of the HCWs (51.4%) were Anti-HBs antibody positive. The overall positivity rate of Anti-HCV antibodies was 2.0%, and HCV-RNA was positive in 33.3% of these samples. Overall, 52% of HCWs reported receiving full vaccination doses (three doses) against HBV infection. Among them, anti-HBs positivity was approximately 98.0%. 3.9% of those who never received any HBV vaccination dose were HBsAg positive, compared to 1.3% HBsAg positive in those HCWs who had received one or two doses of hepatitis B vaccine (p=0.01 for all comparisons). Nurses and nurse-aides had the highest rates of both HBsAg and Anti-HCV among the studied HCWs (HBsAg: 2.1% and 3.2%; Anti-HCV: 3.2% and 4.9%, respectively). It is noteworthy that doctors also had a relatively high prevalence rate of Anti-HCV (2.2%). Obstetric wards, isolation room, dialysis units and dentist work places had higher frequencies of HBV. HCV was found to be higher in the medical and surgical wards (the prevalence varied between 3% and 5.6%). There was no significant difference between HBsAg status and the work period of HCWs. In conclusion, universal precautions should be applied for the care of all patients

  6. Linearized hepatitis B surface antigen and hepatitis B core-related antigen in the natural history of chronic hepatitis B.

    PubMed

    Seto, W-K; Wong, D K-H; Fung, J; Huang, F-Y; Liu, K S-H; Lai, C-L; Yuen, M-F

    2014-11-01

    Changes in two novel HBV serological markers, linearized hepatitis B surface antigen (HQ-HBsAg) and hepatitis B core-related antigen (HBcrAg), in the natural history of chronic hepatitis B (CHB) have not been well characterized. Serum HQ-HBsAg and HBcrAg levels of 404 Asian treatment-naïve CHB patients were analysed in a cross-sectional manner. Patients were categorized into five groups: immune tolerant (IT group, n=52), immune clearance (IC group, n=105), hepatitis B e antigen (HBeAg)-negative hepatitis (ENH group, n=97), HBeAg-negative quiescent group (ENQ group, n=95) and CHB with hepatitis B surface antigen (HBsAg) seroclearance (SC group, n=55). HQ-HBsAg and HBcrAg were measured and correlated with HBV DNA, HBsAg, HBV genotype and clinical parameters. HQ-HBsAg showed good correlation with HBsAg, especially in the ENQ group (r=0.874, p<0.001). Correlation of HQ-HBsAg with HBV DNA was less prominent and weakest in the ENH group (r=0.268, p 0.008). HBcrAg correlated best with HBV DNA in the ENQ group (r=0.537, p<0.001). In the ENQ group, 42.1% of patients had undetectable HBcrAg; this subgroup of patients, when compared with those with detectable HBcrAg, had significantly lower median HBV DNA (3.17/4.48 log IU/mL, p<0.001) and HBsAg (5.05/5.96 log mIU/mL, p<0.001) levels. Forty per cent of the SC group patients had detectable HQ-HBsAg and/or HBcrAg up to 42 months after HBsAg seroclearance. When comparing anti-HBs positivity and median time after HBsAg seroclearance in the SC group with and without detectable HQ-HBsAg/HBcrAg, there was no significant difference (22.7% and 36.4%, respectively, p 0.284, and 76.5 and 93.2 months, respectively, p 0.245). HQ-HBsAg and HBcrAg showed unique patterns of distribution throughout the five disease phases of CHB, including high detectability rates after HBsAg seroclearance, opening up different possibilities for their applicability.

  7. Immunochromatographic assay for quantitative and sensitive detection of hepatitis B virus surface antigen using highly luminescent quantum dot-beads.

    PubMed

    Shen, Jun; Zhou, Yaofeng; Fu, Fen; Xu, Hengyi; Lv, Jiaofeng; Xiong, Yonghua; Wang, Andrew

    2015-09-01

    Hepatitis B virus infection is one of the major causes of hepatitis, liver cirrhosis and liver cancer. In this study, we used highly luminescent quantum dot-beads (QBs) as signal amplification probes in the sandwich immunochromatographic assay (ICA) for ultrasensitive and quantitative detection of hepatitis B virus surface antigen (HBsAg) in human serum. Various parameters that influenced the sensitivity and stability of the QB-based ICA (QB-ICA) sensor were investigated. Two linear independent regression equations for detection of serum HBsAg were expressed with Y=0.3361X-0.0059 (R(2)=0.9983) for low HBsAg concentrations between 75 pg mL(-1) and 4.8 ng mL(-1), and Y=0.8404 X-2.9364 (R(2)=0.9939) for high HBsAg concentrations in the range from 4.8 ng mL(-1) to 75 ng mL(-1). The detection limit of the proposed ICA sensor achieved was 75 pg mL(-1), which is much higher than that of the routinely-used gold nanoparticle based ICA. The intra- and inter-assays recovery rates for spiked serum samples at HBsAg concentrations of 75 pg mL(-1), 3.75 ng mL(-1) and 18.75 ng mL(-1) ranged from 90.14% to 97.6%, and coefficients of variation were all below 7%, indicating that the QB-ICA sensor has an acceptable accuracy for HBsAg detection. Additionally, the quantitative method developed showed no false positive results in an analysis of 49 real HBsAg-negative serum samples, and exhibited excellent agreement (R(2)=0.9209) with a commercial chemiluminescence immunoassay kit in identifying 47 HBsAg-positive serum samples. In summary, due to its high fluorescence intensity, the sandwich QB-ICA sensor is a very promising point-of-care test for rapid, simple and ultrasensitive detection of HBsAg, as well as other disease-related protein biomarkers.

  8. Chronic hepatitis type B in childhood: longitudinal study of 35 cases.

    PubMed Central

    Bortolotti, F; Cadrobbi, P; Crivellaro, C; Bertaggia, A; Alberti, A; Realdi, G

    1981-01-01

    Clinical, virological, and histological features of hepatitis B virus infection have been examined in 35 children, aged 1 to 11 years, known to be hepatitis B surface antigen (HBsAg) carriers for at least six months when entering the study. Only 10 patients had a history of acute unresolved hepatitis: in the remaining cases the detection of HBsAg had been an occasional finding. Although 77% of the patients were asymptomatic, all had evidence of hepatic involvement and liver history showed the features of chronic persistent hepatitis in 18 cases and of chronic active hepatitis in 16 cases, with associated cirrhosis in two of them. One patient had only minimal histological changes. A high percentage of children with both chronic persistent and chronic active hepatitis had evidence of active virus replication throughout the observation period. During the follow-up study of one to eight years (mean 3.1 +/- 1.7 years), transaminase levels became consistently normal in five patients with chronic persistent hepatitis, and inflammatory infiltrates disappeared in three of them. However, only one of these children cleared HBsAg from serum. Eleven of 16 patients with chronic active hepatitis received immunosuppressive treatment but only one of them achieved a complete and protracted remission, although active viral replication persisted. On the other hand, two of five untreated patients reached complete remission after two and three years of follow-up respectively and one of them cleared HBsAg three years later. These results would suggest the possibility of a spontaneous complete remission of HBsAg positive chronic active hepatitis in children but also raise doubts about the usefulness of immunosuppressive therapy in such patients. PMID:7262628

  9. Expression of hepatitis B virus S gene by herpes simplex virus type 1 vectors carrying alpha- and beta-regulated gene chimeras.

    PubMed

    Shih, M F; Arsenakis, M; Tiollais, P; Roizman, B

    1984-09-01

    The domain of the hepatitis B virus (HBV) S gene specifying the HBV surface antigen (HBsAg) and comprising 25 base pairs of the 5'-transcribed noncoding region, the structural gene sequences, and the 3'-noncoding gene sequences including the polyadenylylation site was fused to the promoter-regulatory regions of the beta-thymidine kinase and of the alpha 4 gene of herpes simplex virus type 1 (HSV-1). The chimeric constructs were then inserted into the HSV-1 genome and specifically into the thymidine kinase gene by homologous recombination through flanking sequences. Cells infected with recombinants carrying the chimeric genes produced and excreted the HBsAg into the extracellular medium for at least 12 hr concurrently with the multiplication of the HSV-1 vector. The temporal patterns of expression and the observation that HBV S gene linked to the HSV-1 alpha promoter-regulatory region was regulated as an HSV-1 alpha gene indicate that the HBsAg gene chimeras inserted into the virus were regulated as viral genes. The HBsAg banded in isopycnic CsCl density gradients at a density of 1.17 g/cm3. Electron microscopic studies revealed that HBsAg harvested from the extracellular medium and banded in CsCl density gradients contained spherical particles 15-22 nm in diameter, characteristic of empty HBV envelopes. The results indicate that HSV-1 is a suitable vector for the expression of foreign genes placed under the control of HSV promoter-regulatory regions.

  10. Prophylactic vaccination against hepatitis B: achievements, challenges and perspectives.

    PubMed

    Gerlich, Wolfram H

    2015-02-01

    Large-scale vaccination against hepatitis B virus (HBV) infection started in 1984 with first-generation vaccines made from plasma of chronic carriers containing HBV surface antigen (HBsAg). Thereafter, it was replaced in most countries by second-generation vaccines manufactured in yeast cells transformed with gene S encoding HBsAg. Both generations of vaccines have been applied for universal neonate and early childhood vaccination worldwide and have led to a 70-90 % decrease in chronic HBV carrier rates. However, 10-30% of newborns from HBsAg/HBeAg-positive mothers cannot be protected by passive/active vaccination alone and become chronic HBV carriers themselves. Asymptomatic occult HBV infections are frequent even in those who have protective levels of anti-HBs. Suboptimal protection may be due to heterologous HBsAg subtypes that are present in 99% of HBV carriers worldwide. Second-generation vaccines contain partially misfolded HBsAg and lack preS1 antigen that carries the major HBV attachment site and neutralizing epitopes. Third-generation vaccines produced in mammalian cells contain correctly folded HBsAg and neutralizing epitopes of the preS antigens, induce more rapid protection, overcome nonresponse to second-generation vaccines and, most importantly, may provide better protection for newborns of HBV-positive mothers. PreS/S vaccines expressed in mammalian cells are more expensive to manufacture, but introduction of more potent HBV vaccines should be considered in regions with a high rate of vertical transmission pending assessment of health economics and healthcare priorities. With optimal vaccines and vaccination coverage, eradication of HBV would be possible. PMID:25523195

  11. Unusual presentation of hepatitis B serological markers in an Amerindian community of Venezuela with a majority of occult cases

    PubMed Central

    2011-01-01

    Background Occult hepatitis B infection (OBI) is characterized by the presence of hepatitis B virus (HBV) DNA in the absence of HBsAg in the serum of patients. The aim of this study was to characterize HBV infection among a Piaroa community, an Amerindian group which exhibits significant evidence of exposure to HBV but relatively low presence of HBsAg, and to explore the presence of OBI in this population. Results Of 150 sera, with 17% anti-HBc and 1.3% HBsAg prevalence, 70 were tested for the presence of HBV DNA. From these, 25 (36%) were found positive for HBV DNA by PCR in the core region. Two of these 25 sera were HBsAg positive, indicating an overt infection. Of the remaining 68 sera tested, 23 exhibited OBI. Of these, 13 were HBV DNA out of 25 anti-HBc positive (52%) and 10 HBV DNA positive, out of 43 anti-HBc negative (23%), with a statistical significance of p = 0.03. Viral DNA and HBsAg were present intermittently in follow up sera of 13 individuals. Sequence analysis in the core region of the amplified DNA products showed that all the strains belonged to HBV genotype F3. The OBI isolates displayed 96-100% nucleotide identity between them. One isolate exhibited the co-circulation of a wild type variant with a variant with a premature stop codon at the core protein, and a variant exhibiting a deletion of 28 amino acids. Conclusions The frequency of OBI found in this Amerindian group warrants further studies in other communities exhibiting different degrees of HBV exposure. PMID:22152023

  12. National blood requirement, serum ALT and hepatitis in Ethiopian blood donors.

    PubMed

    Zawde, D; Sisay, Y

    1991-10-01

    To appraise the national blood requirement and supply, and to determine the impact of alanine aminotransferase (ALT) and hepatitis B surface antigen (HBsAg) screening on the blood supply, 407 random blood donor sera were tested for HBsAg, human immunodeficiency virus (HIV), and ALT activity. HBsAg and anti-HIV antibody were determined by the enzyme linked immunosorbent assay (ELISA) technique using Hepanostica and Welcozyme kits, respectively. The Western Blot test was performed to confirm anti-HIV positive sera by the ELISA technique. ALT was determined by an automated photometer using ALAT kits and serologic testing for syphilis was done by the rapid plasma reagin (RPR) test. The amount of blood required in Ethiopia and the actual supply was calculated on the basis of the number and type of hospital beds in Addis Abeba and the amount of blood transfusions in units per hospital bed. The results showed that the combined donor and unit rejection rate was 34.6%. The annual blood requirement was 7 units for emergency and 4 units for nonemergency beds. The national blood requirement in 1989 was 64,350-80,000 units, but the supply met only a third of the requirement. The mean and 2SD cut off ALT levels were 28 and 69 IU/L, respectively. ALT was elevated in 9.1% of HBsAg positive but apparently healthy donors, while HBsAg screening eliminated 25% of those with elevated ALT activity. This data suggests that there is a serious blood shortage in Ethiopia and that the currently supplied blood is relatively unsafe in terms of hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1659534

  13. Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

    PubMed

    An, So Jung; Woo, Joo Sung; Chae, Myung Hwa; Kothari, Sudeep; Carbis, Rodney

    2015-03-24

    The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg. When conjugation was performed without the ADH spacer the induction of an anti-PRP response was equivalent to that seen by conjugate with the ADH spacer, however, a negligible anti-HBsAg response was induced. For comparison, PRP was conjugated to diphtheria toxoid (DT) and Vi polysaccharide purified from Salmonella Typhi conjugated to HBsAg both using an ADH spacer. The PRPAH-DT conjugate induced strong anti-PRP and anti-DT responses, the Vi-AHHBsAg conjugate induced a good anti-HBsAg response but not as strong as that induced by the PRPAH-HBsAg conjugate. This study demonstrated that in mice it was possible to induce robust antibody responses to both polysaccharide and carrier protein provided the conjugate has certain physico-chemical properties. A PRPAH-HBsAg conjugate with the capacity to induce anti-PRP and anti-HBsAg responses could be incorporated into a multivalent pediatric vaccine and simplify formulation of such a vaccine. PMID:25659268

  14. Aggregation and antigenicity of virus like particle in salt solution--A case study with hepatitis B surface antigen.

    PubMed

    Chen, Yi; Zhang, Yan; Quan, Can; Luo, Jian; Yang, Yanli; Yu, Mengran; Kong, Yingjun; Ma, Guanghui; Su, Zhiguo

    2015-08-20

    The phenomenon of aggregation of virus-like particles (VLPs) in salt solution and the corresponding effect upon antigenicity was reported. Asymmetrical flow field-flow fractionation (AF4) combined with multi-angle laser light scattering (MALLS) was used to characterize the size and the aggregation behavior of hepatitis B surface antigen (HBsAg). The average diameter of HBsAg VLP was 22.8±0.4 nm and it tended to aggregate in salt solution to form large particles and the antigenicity changed accordingly. In 0-4 M NaCl solution, part of HBsAg molecules aggregated rapidly into oligomeric particles (OP), whose diameter distributed from 25 to 40 nm, and the antigenicity slightly decreased about 10%. The aggregation reaction is reversible. After removing NaCl, both size and antigenicity could recover to normal level (92-96%). By contrast, the aggregation process is more complicated in (NH4)2SO4 solution. Most of HBsAg particles aggregated into OP and further aggregated into polymeric particles (PP). The diameter of the PP could reach 40 to 140 nm. The concentration of (NH4)2SO4 had remarkable influence upon the rate of aggregation. When concentration of (NH4)2SO4 was below 1 M, most of HBsAg aggregated only into OP in 1 h. While with concentration of (NH4)2SO4 above 1 M, most of particles formed PP within 1 h. The aggregation process to PP was irreversible. After removing (NH4)2SO4, the large aggregates could not recover to normal particles and the remaining antigenicity was below 30%. PMID:25862298

  15. Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

    PubMed

    An, So Jung; Woo, Joo Sung; Chae, Myung Hwa; Kothari, Sudeep; Carbis, Rodney

    2015-03-24

    The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg. When conjugation was performed without the ADH spacer the induction of an anti-PRP response was equivalent to that seen by conjugate with the ADH spacer, however, a negligible anti-HBsAg response was induced. For comparison, PRP was conjugated to diphtheria toxoid (DT) and Vi polysaccharide purified from Salmonella Typhi conjugated to HBsAg both using an ADH spacer. The PRPAH-DT conjugate induced strong anti-PRP and anti-DT responses, the Vi-AHHBsAg conjugate induced a good anti-HBsAg response but not as strong as that induced by the PRPAH-HBsAg conjugate. This study demonstrated that in mice it was possible to induce robust antibody responses to both polysaccharide and carrier protein provided the conjugate has certain physico-chemical properties. A PRPAH-HBsAg conjugate with the capacity to induce anti-PRP and anti-HBsAg responses could be incorporated into a multivalent pediatric vaccine and simplify formulation of such a vaccine.

  16. Cryogenic Orbital Testbed (CRYOTE) Ground Test Article, Final Report

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley L.; Rhys, Noah O.; Bradley, David E.; Wollen, Mark; Kutter, Bernard; Gravlee, Mari; Walls, Laurie K.

    2015-01-01

    Liquid propulsion has been used since Robert Goddard started developing a liquid oxygen (LO2) and gasoline powered rocket and fired it in 1923 (Ref. 1). In the following decades engineers settled on the combination of liquid hydrogen (LH2) and LO2 as the most efficient propellant combination for in-space travel. Due to their low temperatures (LH2 at 20 K and LO2 at 90 K), they require special handling and procedures. General Dynamics began developing LO2 and LH2 upper stages in 1956 in the form of Centaur, these efforts were soon funded by the Department of Defense in conjunction with NASA (beginning in 1958) (Ref. 2). Meanwhile NASA also worked with McDonnell Douglas to develop the SIV-B stage for the Saturn V rocket. In the subsequent years, the engineers were able to push the Centaur to up to 9 hr of orbital lifetime and the SIV-B to up to 6 hr. Due to venting the resultant boil-off from the high heat loads through the foam insulation on the upper stages, both vehicles remained in a settled configuration throughout the flights, thus the two phases of propellant (liquid and vapor) were separated at a known location. The one exception to this were the Titan/Centaur missions, which thanks to the lower boil-off using three layers of multilayer insulation (MLI), were able to coast unsettled for up to 5.25 hr during direct geosynchronous orbit insertion missions. In the years since there has been a continuous effort to extend the life of these upper stages from hours to days or even months.

  17. A Model for the Common Origin of Jupiter Family and Halley Type Comets

    NASA Astrophysics Data System (ADS)

    Emel'yanenko, V. V.; Asher, D. J.; Bailey, M. E.

    2013-02-01

    A numerical simulation of the Oort cloud is used to explain the observed orbital distributions and numbers of Jupiter-family (JF) and Halley-type (HT) short-period (SP) comets. Comets are given initial orbits with perihelion distances between 5 and 36 au, and evolve under planetary, stellar and Galactic perturbations for 4.5 Gyr. This process leads to the formation of an Oort cloud (which we define as the region of semimajor axes a > 1,000 au), and to a flux of cometary bodies from the Oort cloud returning to the planetary region at the present epoch. The results are consistent with the dynamical characteristics of SP comets and other observed cometary populations: the near-parabolic flux, Centaurs, and high-eccentricity trans-Neptunian objects. To achieve this consistency with observations, the model requires that the number of comets versus initial perihelion distance is concentrated towards the outer planetary region. Moreover, the mean physical lifetime of observable comets in the inner planetary region ( q < 2.5 au) at the present epoch should be an increasing function of the comets' initial perihelion distances. Virtually all observed HT comets and nearly half of observed JF comets come from the Oort cloud, and initially (4.5 Gyr ago) from orbits concentrated near the outer planetary region. Comets that have been in the Oort cloud also return to the Centaur (5 < q < 28 au, a < 1,000 au) and near-Neptune high-eccentricity regions. Such objects with perihelia near Neptune are hard to discover, but Centaurs with characteristics predicted by the model (e.g. large semimajor axes, above 60 au, or high inclinations, above 40°) are increasingly being found by observers. The model provides a unified picture for the origin of JF and HT comets. It predicts that the mean physical lifetime of all comets in the region q < 1.5 au is less than ˜200 revolutions.

  18. Rosetta/VIRTIS-M spectral data: Comet 67P/CG compared to other primitive small bodies.

    NASA Astrophysics Data System (ADS)

    De Sanctis, M. C.; Capaccioni, F.; Filacchione, G.; Erard, S.; Tosi, F.; Ciarniello, M.; Raponi, A.; Piccioni, G.; Leyrat, C.; Bockelée-Morvan, D.; Drossart, P.; Fornasier, S.

    2014-12-01

    VIRTIS-M, the Visible InfraRed Thermal Imaging Spectrometer, onboard the Rosetta Mission orbiter (Coradini et al., 2007) acquired data of the comet 67P/Churyumov-Gerasimenko in the 0.25-5.1 µm spectral range. The initial data, obtained during the first mission phases to the comet, allow us to derive albedo and global spectral properties of the comet nucleus as well as spectra of different areas on the nucleus. The characterization of cometary nuclei surfaces and their comparison with those of related populations such as extinct comet candidates, Centaurs, near-Earth asteroids (NEAs), trans-Neptunian objects (TNOs), and primitive asteroids is critical to understanding the origin and evolution of small solar system bodies. The acquired VIRTIS data are used to compare the global spectral properties of comet 67P/CG to published spectra of other cometary nuclei observed from ground or visited by space mission. Moreover, the spectra of 67P/Churyumov-Gerasimenko are also compared to those of primitive asteroids and centaurs. The comparison can give us clues on the possible common formation and evolutionary environment for primitive asteroids, centaurs and Jupiter-family comets. Authors acknowledge the funding from Italian and French Space Agencies. References: Coradini, A., Capaccioni, F., Drossart, P., Arnold, G., Ammannito, E., Angrilli, F., Barucci, A., Bellucci, G., Benkhoff, J., Bianchini, G., Bibring, J. P., Blecka, M., Bockelee-Morvan, D., Capria, M. T., Carlson, R., Carsenty, U., Cerroni, P., Colangeli, L., Combes, M., Combi, M., Crovisier, J., De Sanctis, M. C., Encrenaz, E. T., Erard, S., Federico, C., Filacchione, G., Fink, U., Fonti, S., Formisano, V., Ip, W. H., Jaumann, R., Kuehrt, E., Langevin, Y., Magni, G., McCord, T., Mennella, V., Mottola, S., Neukum, G., Palumbo, P., Piccioni, G., Rauer, H., Saggin, B., Schmitt, B., Tiphene, D., Tozzi, G., Space Science Reviews, Volume 128, Issue 1-4, 529-559, 2007.

  19. COLOR SYSTEMATICS OF COMETS AND RELATED BODIES

    SciTech Connect

    Jewitt, David

    2015-12-15

    Most comets are volatile-rich bodies that have recently entered the inner solar system following long-term storage in the Kuiper belt and the Oort cloud reservoirs. These reservoirs feed several distinct, short-lived “small body” populations. Here, we present new measurements of the optical colors of cometary and comet-related bodies including long-period (Oort cloud) comets, Damocloids (probable inactive nuclei of long-period comets) and Centaurs (recent escapees from the Kuiper belt and precursors to the Jupiter family comets). We combine the new measurements with published data on short-period comets, Jovian Trojans and Kuiper belt objects to examine the color systematics of the comet-related populations. We find that the mean optical colors of the dust in short-period and long-period comets are identical within the uncertainties of measurement, as are the colors of the dust and of the underlying nuclei. These populations show no evidence for scattering by optically small particles or for compositional gradients, even at the largest distances from the Sun, and no evidence for ultrared matter. Consistent with earlier work, ultrared surfaces are common in the Kuiper belt and on the Centaurs, but not in other small body populations, suggesting that this material is hidden or destroyed upon entry to the inner solar system. The onset of activity in the Centaurs and the disappearance of the ultrared matter in this population begin at about the same perihelion distance (∼10 AU), suggesting that the two are related. Blanketing of primordial surface materials by the fallback of sub-orbital ejecta, for which we calculate a very short timescale, is the likely mechanism. The same process should operate on any mass-losing body, explaining the absence of ultrared surface material in the entire comet population.

  20. Tracking and data relay satellite system configuration and tradeoff study. Volume 2: System engineering, part 1, final report

    NASA Technical Reports Server (NTRS)

    1972-01-01

    All elements of the TDRS system were studied with emphasis on the design of a 3-axis stabilized satellite, and a telecommunication system optimized for support of low and medium data rate user spacecraft constrained to be launched on a Delta 2914. The research is reported to upgrade the spacecraft design to provide telecommunications support low, medium and high data rate users, considering launches with the Atlas/Centaur and the space shuttle. For Vols. 4, 5, 7, and 8, see N74-10809 through N74-10812.

  1. Axial jet mixing of ethanol in cylindrical containers during weightlessness

    NASA Technical Reports Server (NTRS)

    Aydelott, J. C.

    1979-01-01

    An experimental program was conducted to examine the liquid flow patterns that result from the axial jet mixing of ethanol in 10-centimeter-diameter cylindrical tanks in weightlessness. A convex hemispherically ended tank and two Centaur liquid-hydrogen-tank models were used for the study. Four distinct liquid flow patterns were observed to be a function of the tank geometry, the liquid-jet velocity, the volume of liquid in the tank, and the location of the tube from which the liquid jet exited.

  2. Study of extraterrestrial disposal of radioactive wastes. Part 1: Space transportation and destination considerations for extraterrestrial disposal of radioactive wastes. [feasibility of using space shuttle

    NASA Technical Reports Server (NTRS)

    Thompson, R. L.; Ramler, J. R.; Stevenson, S. M.

    1974-01-01

    A feasibility study of extraterrestrial disposal of radioactive waste is reported. This report covers the initial work done on only one part of the NASA study, that evaluates and compares possible space destinations and space transportation systems. The currently planned space shuttle was found to be more cost effective than current expendable launch vehicles by about a factor of 2. The space shuttle requires a third stage to perform the waste disposal missions. Depending on the particular mission, this third stage could be either a reusable space tug or an expendable stage such as a Centaur.

  3. Summary of the study of disposal of nuclear waste into space

    NASA Technical Reports Server (NTRS)

    Rom, F. E.

    1973-01-01

    NASA, at the request of the AEC, is conducting a preliminary study to determine the feasibility of disposing of nuclear waste material into space. The study has indicated that the Space Shuttle together with expendable and nonexpendable orbital stages such as the Space Tug or Centaur can safety dispose of waste material by ejecting it from the solar system. The safety problems associated with all phases of launching and operation (normal, emergency and accident) of such a system are being examined. From the preliminary study it appears that solutions can be found that should make the risks acceptable when compared to the benefits to be obtained from the disposal of the nuclear waste.

  4. Summary of the study of disposal of nuclear waste into space

    NASA Technical Reports Server (NTRS)

    Rom, F. E.

    1973-01-01

    The space shuttle together with expendable and nonexpendable orbital stages such as the space tug or Centaur can safely dispose of waste material by ejecting it from the solar system. The safety problems associated with all phases of launching and operation (normal, emergency, and accident) of such a system are being examined. It appears that solutions can be found that should make the risks acceptable when compared to the benefits to be obtained from the disposal of the nuclear waste. The techniques proposed to make such a system acceptable need to be carefully verified by further study and experiment.

  5. Investigation of Super*Zip separation joint

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1988-01-01

    An investigation to determine the most likely cause of two failures of five tests on 79 inch diameter Lockheed Super*Zip spacecraft separation joints being used for the development of a Shuttle/Centaur propulsion system. This joint utilizes an explosively expanded tube to fracture surrounding prenotched aluminum plates to achieve planar separation. A test method was developed and more than 300 tests firings were made to provide an understanding of severance mechanisms and the functional performance effects of system variables. An approach for defining functional margin was developed, and specific recommendations were made for improving existing and future systems.

  6. D-1A nose fairing separation fitting load test

    NASA Technical Reports Server (NTRS)

    Vanvleet, J. O.

    1976-01-01

    Structural testing of the D-1A Centaur nose fairing was completed to determine the loads imposed during flight on the latch bolts of the fairing separation system. This testing was conducted to supplement and/or verify the analytic techniques used in calculating bolt loads for the D-1A, and to gain insight into the general structural behavior of separation latch systems. It was shown that the assumed bolt load magnification due to prying action of the latch fittings on the bolt does occur, but is strongly dependent on fairing shell stiffness.

  7. A damper for ground wind-induced launch vehicle oscillations

    NASA Technical Reports Server (NTRS)

    Bodle, J. G.; Hackley, D. S.

    1975-01-01

    Prelaunch oscillatory bending deflections of the Atlas/Centaur launch vehicle are restrained by a damper mechanism mounted on the end of a horizontal boom supported from the umbilical tower. A single vertical pin on the vehicle engages the mechanism, and the damper is connected to the vehicle until liftoff. As the attach pin rises with the vehicle, a retractable arm mechanism provides initial clearance. An explosive release mechanism allows the boom to swing clear of the vehicle like a pendulum, while a snubber mechanism decelerates the free swinging boom and damper mechanism to a safe stop.

  8. Amphiaraos of Attica: the "Second Asclepius".

    PubMed

    Iavazzo, Christos; Gkegkes, Ioannis D; Gkegke, Xanthi-Ekaterini D; Ntziora, Fotinie

    2012-01-01

    Amphiaraos is one of the most prominent Greek heroes. He was the son of god Apollo and student of Centaur Chiron from whom he learned the art of medicine. He was thought to be the "Second Asclepius" and he had many sanctuaries around Greece of which the most well known is the Amphiaraeion of Oropos, near Athens. The aim of this study is to present the genealogical tree and life of Amphiaraos, as well as the methods used in his sanctuaries in order to offer cure in the ill pilgrims.

  9. Project Intelsat 5

    NASA Technical Reports Server (NTRS)

    1980-01-01

    With 12,000 voice circuits and 2 television channels, intelsat 5, the first of a new generation of international telecommunication satellites, has almost double the communication capability of early satellites in the series. The 1,928 kilogram (at a lunch) satellite will be placed into geosynchronous orbit over the Atlantic Ocean to provide communications between North America and Europe. The characteristics of the Atlas Centaur launch vehicle to be used are described and the flights events of the launch sequence are tabulated.

  10. MARINER 8 SPACE PROBE'S SOLAR ARRAYS ARE INSTALLED

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Technicians prepare to install a solar panel on the Mariner H spacecraft in preparation for its launch to Mars, no earlier than May 7, 1971. The spacecraft will be launched aboard an Atlas Centaur space vehicle from Cape Kennedy's Complex 36A, and will go into orbit around Mars at the completion of a seven-month journey from Earth. It is designed to operate 90 days and return data about the planet's atmospheric and surface characteristics. Following launch, the spacecraft will be designated Mariner 8. A second Mariner Mars spacecraft is scheduled to be launched 10 days later.

  11. MARINER 8 SPACE PROBE UNDERGOES INSTALLATION OF SOLAR ARRAYS

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Technicians install solar panels aboard the mariner H spacecraft in a cleanroom facility at Cape Kennedy. The spacecraft will orbit Mars following a seven-month journey from Earth. Designed to function 90 days, the spacecraft, which will be designated Mariner 8 following launch, will provide data about the Red Planet's atmospheric and surface characteristics. Mariner Mars H will be launched aboard an Atlas-Centaur space vehicle no earlier than May 7, 1971, from Cape Kennedy's Launch Complex 36A. A second Mariner Mars spacecraft will be launched 10 days later.

  12. The commercial Atlas today

    NASA Astrophysics Data System (ADS)

    Patzer, Mike; White, Robert C.

    1990-07-01

    Spanning more than three decades, the General Dynamics Atlas launch vehicle program has contributed greatly to the productive exploitation of space. This paper briefly reviews Atlas history and achievements and then focuses on present Atlas launch vehicle configurations, capabilities, and propulsion systems. The four-vehicle Atlas family is described, inluding manufacturing, performance, and design differences. Vehicle launch options including the fairing and spacecraft adapter are discussed. A mission profile, flight environments, and a nominal sequence of events are described for a standard GTO mission. Details on vehicle enhancements are presented including the addition of solid rocket motors, booster and Centaur engine uprates, and avionics improvements.

  13. Space nuclear power system and the design of the nuclear electric propulsion OTV

    SciTech Connect

    Buden, D.; Garrison, P.W.

    1984-01-01

    Payload increases of three to five times that of the Shuttle/Centaur can be achieved using nuclear electric propulsion. Various nuclear power plant options being pursued by the SP-100 Program are described. These concepts can grow from 100 kW/sub e/ to 1MW/sub e/ output. Spacecraft design aspects are addressed, including thermal interactions, plume interactions, and radiation fluences. A baseline configuration is described accounting for these issues. Safety aspects of starting the OTV transfer from an altitude of 300 km indicate no significant additional risk to the biosphere.

  14. Acquisition/expulsion system for earth orbital propulsion system study. Volume 4: Flight test article

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Two orbital test plans were prepared to verify one of the passive cryogenic storage tank/feedline candidate designs. One plan considered the orbital test article to be launched as a dedicated payload using an Atlas F burner launching configuration. The second plan proposed to launch the orbital test article as a secondary payload on the Titan E/Centaur proof flight. The secondary payload concept was pursued until January 1973, when work to build the hardware for this phase of the contract was terminated for lack of a sponsor for the flight. The dedicated payload launched on an Atlas F is described.

  15. COMPASS Final Report: Saturn Moons Orbiter Using Radioisotope Electric Propulsion (REP): Flagship Class Mission

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2011-01-01

    The COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) team was approached by the NASA Glenn Research Center (GRC) In-Space Project to perform a design session to develop Radioisotope Electric Propulsion (REP) Spacecraft Conceptual Designs (with cost, risk, and reliability) for missions of three different classes: New Frontier s Class Centaur Orbiter (with Trojan flyby), Flagship, and Discovery. The designs will allow trading of current and future propulsion systems. The results will directly support technology development decisions. The results of the Flagship mission design are reported in this document

  16. Amphiaraos of Attica: the "Second Asclepius".

    PubMed

    Iavazzo, Christos; Gkegkes, Ioannis D; Gkegke, Xanthi-Ekaterini D; Ntziora, Fotinie

    2012-01-01

    Amphiaraos is one of the most prominent Greek heroes. He was the son of god Apollo and student of Centaur Chiron from whom he learned the art of medicine. He was thought to be the "Second Asclepius" and he had many sanctuaries around Greece of which the most well known is the Amphiaraeion of Oropos, near Athens. The aim of this study is to present the genealogical tree and life of Amphiaraos, as well as the methods used in his sanctuaries in order to offer cure in the ill pilgrims. PMID:25761361

  17. Feasibility demonstration for hydrogen chloride detection using a chemisorption technique and a quartz crystal microbalance

    NASA Technical Reports Server (NTRS)

    Jex, D. W.; Workman, G. L.

    1975-01-01

    A method of measuring concentrations of hydrogen chloride between 1 part per billion and 10 parts per million at standard temperature and pressure is presented. The feasibility of a low-cost device incorporating a chemisorption technique coupled with a quartz crystal microbalance was demonstrated in the field at the Viking B launch using a Titan-Centaur vehicle from Kennedy Space Center on August 20, 1975. Hydrogen chloride is a product of solid rocket combustion. The concentration level of hydrogen chloride for this particular launch was measured as approximately 0.2 parts per million at 4 km from the launch site.

  18. ADDJUST-A View of the First 25 Years

    NASA Technical Reports Server (NTRS)

    Nieberding, Joe; Williams, Craig H.

    2015-01-01

    Various technologies and innovative launch operations were developed during the 50 years of the Centaur upper stage—the first launch vehicle to use high performing liquid hydrogen fuel. One innovation was “ADDJUST”, which enabled the successful negotiation of upper level winds measured only hours before launch. Initial causes for its creation, development, and operation during countdown are detailed. Problem definition, wind measuring/monitoring process, pitch and yaw steering coefficient generation, loads analysis, angle of attack, major risks/concerns, and anecdotal recollections are provided. Launch availability improved from as low as 55 to 95 percent due to ADDJUST, which is still in use.

  19. Tracking and data relay satellite system configuration and tradeoff study. Volume 1: Summary. Part 2: Final Report, 22 August 1972 - 1 April 1973

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A Tracking and Data Relay Satellite System (TDRSS) concept for service of low, medium, and high data rate user spacecraft has been defined. During the study, four TDRS dual spin stabilized configurations (contractual requirement) were designed; two are compatible with Delta 2914, one with Atlas Centaur, and one with space shuttle launches. A summary of the study and the salient results are presented. The topics included are: (1) TDRSS operations, (2) telecommunications service performance, telecommunications service equipment, (3) TDRS configurations and their design characteristics, and (4) TDRS system reliability.

  20. Asteroidi: perché osservarli? Sono piccoli, brutti e vicini

    NASA Astrophysics Data System (ADS)

    Foglia, Sergio

    2002-01-01

    Astronomers interest about asteroids has rapidly grown in the last years. This work is a brief review of the actual knowledge with the aim of involving more amateur astronomers in this research. Spatial configuration of minor planets is shown with the two asteroid belts named "main belt" and "Edgeworth-Kuiper belt"; also Centaurs, Trojan and Near Earth Asteroids are identified and the potential collision with the Earth is discussed. The effect of resonances is explained. Observational contribute of amateurs: astrometry and photometry are summarized and the contribution of Italian amateurs is discussed.

  1. Reflectance Spectra of Titan Tholins at Cryogenic Temperatures and Implications for Compositional Interpretation of Red Objects in the Outer Solar System

    NASA Technical Reports Server (NTRS)

    Roush, T. L.; Dalton, J. B.

    2002-01-01

    We report the visual and near-infrared (0.4-2.5 micron) laboratory bi-directional reflectance of Titan tholin at cryogenic temperatures (approx. 100-300 K). When compared with room temperature measurements, the visual and near-infrared color of Titan tholin becomes slightly redder by approx. 5% at low temperatures in the 0.4-1.3 micron region. We estimate the influence of these colr changes on the interpretation of the Centaur Pholus and find that the modest color changes will not significantly alter existing interpretations.

  2. TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of nine bright targets at 70-500 μm

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lellouch, E.; Müller, T.; Santos-Sanz, P.; Panuzzo, P.; Kiss, C.; Lim, T.; Mommert, M.; Bockelée-Morvan, D.; Vilenius, E.; Stansberry, J.; Tozzi, G. P.; Mottola, S.; Delsanti, A.; Crovisier, J.; Duffard, R.; Henry, F.; Lacerda, P.; Barucci, A.; Gicquel, A.

    2013-07-01

    Aims: Trans-Neptunian objects (TNOs) are bodies populating the Kuiper belt and they are believed to retain the most pristine and least altered material of the solar system. The Herschel open time key programme entitled "TNOs are Cool: A survey of the trans-Neptunian region" has been awarded 373 h to investigate the albedo, size distribution and thermal properties of TNOs and Centaurs. Here we focus on the brightest targets observed by both the PACS and SPIRE multiband photometers: the dwarf planet Haumea, six TNOs (Huya, Orcus, Quaoar, Salacia, 2002 UX25, and 2002 TC302), and two Centaurs (Chiron and Chariklo). Methods: Flux densities are derived from PACS and SPIRE instruments using optimised data reduction methods. The spectral energy distribution obtained with the Herschel PACS and SPIRE instruments over 6 bands (centred at 70, 100, 160, 250, 350, and 500 μm), with Spitzer-MIPS at 23.7 and 71.4 μm, and with WISE at 11.6 and 22.1 μm in the case of 10199 Chariklo, has been modelled with the NEATM thermal model in order to derive the albedo, diameter, and beaming factor. For the Centaurs Chiron and Chariklo and for the 1000 km sized Orcus and Quaoar, a thermophysical model was also run to better constrain their thermal properties. Results: We derive the size, albedo, and thermal properties, including thermal inertia and surface emissivity, for the 9 TNOs and Centaurs. Several targets show a significant decrease in their spectral emissivity longwards of ~300 μm and especially at 500 μm. Using our size estimations and the mass values available in the literature, we also derive the bulk densities for the binaries Quaoar/Weywot (2.18-0.36+0.43 g/cm3), Orcus/Vanth (1.53-0.13+0.15 g/cm3), and Salacia/Actea (1.29-0.23+0.29 g/cm3). Quaoar's density is similar to that of the other dwarf planets Pluto and Haumea, and its value implies high contents of refractory materials mixed with ices. Herschel is an ESA space observatory with science instruments provided by European

  3. Space nuclear power system and the design of the nuclear electric propulsion OTV

    NASA Technical Reports Server (NTRS)

    Buden, D.; Garrison, P. W.

    1984-01-01

    Payload increases of three to five times that of the Shuttle/Centaur can be achieved using nuclear electric propulsion. Various nuclear power plant options being pursued by the SP-100 Program are described. These concepts can grow from 100 kWe to 1 MWe output. Spacecraft design aspects are addressed, including thermal interactions, plume interactions, and radiation fluences. A baseline configuration is described accounting for these issues. Safety aspects of starting the OTV transfer from an altitude of 300 km indicate no significant additional risk to the biosphere.

  4. Nuclear Electric Propulsion mission operations.

    NASA Technical Reports Server (NTRS)

    Prickett, W. Z.; Spera, R. J.

    1972-01-01

    Mission operations are presented for comet rendezvous and outer planet exploration missions conducted by unmanned Nuclear Electric Propulsion (NEP) system employing in-core thermionic reactors for electric power generation. The selected reference mission are Comet Halley rendezvous and a Jupiter orbiter at 5.9 planet radii, the orbit of the moon Io. Mission operations and options are defined from spacecraft assembly through mission completion. Pre-launch operations and related GSE requirements are identified. Shuttle launch and subsequent injection to earth escape by the Centaur d-1T are discussed, as well as power plant startup and heliocentric mission phases.

  5. Viking Mars launch set for August 11

    NASA Technical Reports Server (NTRS)

    Panagakos, N.

    1975-01-01

    The 1975-1976 Viking Mars Mission is described in detail, from launch phase through landing and communications relay phase. The mission's scientific goals are outlined and the various Martian investigations are discussed. These investigations include: geological photomapping and seismology; high-resolution, stereoscopic horizon scanning; water vapor and thermal mapping; entry science; meteorology; atmospheric composition and atmospheric density; and, search for biological products. The configurations of the Titan 3/Centaur combined launch vehicles, the Viking orbiters, and the Viking landers are described; their subsystems and performance characteristics are discussed. Preflight operations, launch window, mission control, and the deep space tracking network are also presented.

  6. PFERD Mission: Pluto Flyby Exploration/Research Design

    NASA Technical Reports Server (NTRS)

    Lemke, Gary; Zayed, Husni; Herring, Jason; Fuehne, Doug; Sutton, Kevin; Sharkey, Mike

    1990-01-01

    The Pluto Flyby Exploration/Research Design (PFERD) mission will consist of a flyby spacecraft to Pluto and its satellite, Charon. The mission lifetime is expected to be 18 years. The Titan 4 with a Centaur upper stage will be utilized to launch the craft into the transfer orbit. The proposal was divided into six main subsystems: (1) scientific instrumentation; (2) command, communications, and control: (3) altitude and articulation control; (4) power and propulsion; (5) structures and thermal control; and (6) mission management and costing. Tradeoff studies were performed to optimize all factors of design, including survivability, performance, cost, and weight. Problems encountered in the design are also presented.

  7. New strategies for blood donor screening for hepatitis B virus: nucleic acid testing versus immunoassay methods.

    PubMed

    Kuhns, Mary C; Busch, Michael P

    2006-01-01

    Serologic testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc) has historically been the foundation of blood screening, while HBV nucleic acid testing (NAT) was recently developed to detect HBsAg-negative, anti-HBc-negative blood units donated during early acute infection. Comparison data on seroconversion panels using HBsAg assays of varying sensitivities and pooled- or single-sample NAT, along with viral load estimates corresponding to HBsAg assay detection limits, have provided information on the theoretical benefits of NAT relative to HBsAg. Model-derived estimates have generally been predictive of the yields of DNA-positive, HBsAg-negative window period blood units detected in a number of studies from Europe, Japan, and the US. Studies indicate that the added benefit of pooled-sample NAT is relatively small in areas of low endemicity, with greater yields in areas highly endemic for HBV. Single-sample NAT would offer more significant early window period closure and could prevent a moderate number of residual HBV transmissions not detected by HBsAg assays; however, no fully automated single-sample HBV NAT systems are currently available.Even single-sample HBV NAT may not substitute for anti-HBc screening, as indicated by studies of donors with isolated anti-HBc who have extremely low DNA levels undetectable by standard single-sample NAT and who have been associated with transfusion-transmitted HBV. Moreover, HBsAg testing may still be needed even in the setting of combined anti-HBc and NAT screening. HBsAg-positive units from donors in the chronic stage of infection may contain very low or intermittently detectable DNA levels that single-sample NAT would miss. Although such donors are usually anti-HBc reactive and would be interdicted by anti-HBc screening, some lack anti-HBc. Extensive parallel testing will be needed to determine whether single-sample NAT in combination with anti-HBc might be sufficient to

  8. Hematologic and biochemical reference intervals for specific pathogen free 6-week-old Hampshire-Yorkshire crossbred pigs

    PubMed Central

    2014-01-01

    Background Hematologic and biochemical reference intervals depend on many factors, including age. A review of the literature highlights the lack of reference intervals for 6-wk-old specific pathogen free (SPF) Hampshire-Yorkshire crossbred pigs. For translational research, 6-wk-old pigs represent an important animal model for both human juvenile colitis and diabetes mellitus type 2 given the similarities between the porcine and human gastrointestinal maturation process. The aim of this study was to determine reference intervals for hematological and biochemical parameters in healthy 6-wk-old crossbred pigs. Blood samples were collected from 66 clinically healthy Hampshire-Yorkshire pigs. The pigs were 6 wks old, represented both sexes, and were housed in a SPF facility. Automated hematological and biochemical analysis were performed using an ADVIA 120 Hematology System and a Cobas 6000 C501 Clinical Chemistry Analyzer. Results Reference intervals were calculated using both parametric and nonparametric methods. The mean, median, minimum, and maximum values were calculated. Conclusion As pigs are used more frequently as medical models of human disease, having reference intervals for commonly measured hematological and biochemical parameters in 6-wk-old pigs will be useful. The reference intervals calculated in this study will aid in the diagnosis and monitoring of both naturally occurring and experimentally induced disease. In comparison to published reference intervals for older non SPF pigs, notable differences in leukocyte populations, and in levels of sodium, potassium, glucose, protein, and alkaline phosphatase were observed. PMID:24410946

  9. A new enzyme-linked chemiluminescent immunosorbent digoxin assay is virtually free from interference of spironolactone, potassium canrenoate, and their common metabolite canrenone.

    PubMed

    Dasgupta, Amitava; Kang, Edward; Datta, Pradip

    2006-01-01

    Spironolactone and potassium canrenoate (aldosterone antagonist diuretics) are sometimes used in conjunction with digoxin for patient management. Spironolactone, potassium canrenoate, and their common metabolite canrenone interfere with serum digoxin measurement using various immunoassays. Recently a new enzyme-linked chemiluminescent immunosorbent digoxin assay (ECLIA-Digoxin) became commercially available for application on the ADVIA IMS 800i modular system (Bayer HealthCare, Tarrytown, NY). We investigated the potential interference of spironolactone and related compounds in this assay by comparing the results with the fluorescence polarization immunoassay (FPIA), which is known to have significant cross-reactivity with these compounds as well as a turbidimetric assay for digoxin with no known cross-reactivity with spironolactone and related compounds. Aliquots of drug free serum were supplemented with therapeutic and above therapeutic concentrations of spironolactone, canrenone, and potassium canrenoate, and apparent digoxin concentrations were measured. No apparent digoxin concentration was observed using the ECLIA-Digoxin or turbidimetric assay. When serum pools prepared from patients receiving digoxin were further supplemented with these compounds, we observed no significant change in digoxin concentrations in the presence of these compounds with the ECLIA-Digoxin. We conclude that this assay is virtually free from interferences from spironolactone, potassium canrenoate and their common metabolite canrenone. PMID:16960898

  10. Large hepatitis delta antigen in packaging and replication inhibition: role of the carboxyl-terminal 19 amino acids and amino-terminal sequences.

    PubMed

    Lee, C Z; Chen, P J; Chen, D S

    1995-09-01

    Hepatitis delta virus (HDV) encodes two proteins, the small delta antigen (SHDAg) and large delta antigen (LHDAg). The latter is identical to the former except for the presence of additional 19 amino acids at the C terminus. While SHDAg is required for HDV replication, LHDAg inhibits replication and, together with hepatitis B surface antigen (HBsAg), is required for the assembly of HDV. The last 19 C-terminal amino acids of LHDAg are essential for HDV assembly. Most of LHDAg (amino acids 19 to 146 and 163 to 195) had been shown to be dispensable for packaging with HBsAg. To discern whether the last 19 C-terminal amino acids solely constitute the signal for packaging with HBsAg, we constructed two LHDAg deletion mutants and tested their abilities to be packaged with HBsAg in cotransfection experiments. We found that deletion of amino acids 2 to 21 and 142 to 165 did not affect LHDAg packaging. This result suggested that only the last 19 C-terminal amino acids of LHDAg are required for packaging. We further constructed two plasmids which expressed c-H-ras with or without additional 19 C-terminal amino acids identical to those in LHDAg. Only c-H-ras with additional 19 amino acids could be cosecreted with HBsAg in the cotransfection experiment. This result confirmed that the C-terminal 19 amino acids are the packaging signal for HBsAg. We also tested the trans activation activity and trans-dominant inhibitory activity of the deletion mutants of SHDAg and LHDAg, respectively. In contrast to deletion of amino acids 142 to 165, deletion of amino acids 2 to 21 impaired the trans-dominant inhibitory activity of LHDAg. Deletion of amino acids 2 to 21 and 142 to 165 did not affect the trans activation activity of SHDAg. This result suggested that a functional domain which is important for the trans-dominant inhibitory activity of LHDAg exists in the amino terminus of HDAg. PMID:7636976

  11. Expression of hepatitis B virus S gene in Pichia pastoris and application of the product for detection of anti-HBs antibody.

    PubMed

    Bo, Hu; Minjian, Liang; Guoqiang, Hong; Zhaoxia, Li; Zhenyu, Zhu; Lin, Li

    2005-11-30

    Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying a hexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5 % of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100 % with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent

  12. Impact of Universal Hepatitis B Vaccination on Prevalence, Infection-Associated Morbidity and Mortality, and Circulation of Immune Escape Variants in Russia

    PubMed Central

    Klushkina, Vitalina V.; Kyuregyan, Karen K.; Kozhanova, Tatiana V.; Popova, Oksana E.; Dubrovina, Polina G.; Isaeva, Olga V.; Gordeychuk, Ilya V.; Mikhailov, Mikhail I.

    2016-01-01

    Vaccination of newborns against hepatitis B (HB) was introduced in Russia in 1998. Since then the incidence of acute HB has rapidly declined. However, prevalence of chronic HB remains stable. The aim of this study was to estimate the effect of vaccination on HBV-associated morbidity, and to assess the prevalence of HBV immune escape variants after 10 years of vaccination. Methods 6,217 sera samples collected from volunteers in six epidemiologically different regions of Russia were tested for serological and molecular markers of HBV infection. A mathematical model developed by the U.S. Centers for Disease Control and Prevention was used to estimate the effect of vaccination and birth dose coverage on the incidence of HB and adverse outcomes of infection. Results Prevalence of HBsAg in the study population varied from 1.2% to 8.2%; anti-HBc detection rates were 13.0–46.2%. HBsAg detection rates in epidemiologically significant cohorts were 0.6–10.5% in women of childbearing age; 0–2.4% in children ≤5 years old; 1.9–8.1% in adults ≥30 years old. Mathematical modeling demonstrated that the current 96.1–99.6% level of birth dose coverage increased the effectiveness of vaccination 10–21 times compared to 50% and 0% birth dose coverage scenarios. HBV DNA was detected in 63 sera samples. The frequency of amino acid substitutions in HBsAg was 38% (24/63). Only in 3% (2/63) the mutations were within the a-determinant of HBsAg (M133T and G145S, one case each). None of the identified mutations eluded HBsAg detection, since all these samples tested positive for HBsAg by commercial ELISA. Conclusion Despite a significant decline in acute HB incidence after the introduction of universal vaccination, many undiagnosed potential sources of infection remain. Low prevalence of HBV immune escape variants is a favorable predictor of vaccine effectiveness in the future. PMID:27280884

  13. Seroprevalence and biochemical features of hepatitis B surface antigenemia in patients with HIV-1 infection in Lagos, Nigeria.

    PubMed

    Iwalokun, B A; Hodonu, S O; Olaleye, B M; Olabisi, O A

    2006-09-01

    Studies have confirmed HBsAg antigenemia as an important correlate of HIV-1 infections in Nigeria. However, the hepatic pathophysiology and therapeutic implications in antiretroviral regimens are poorly understood. In this study, fifty-four HIV-1 seropositive patients aged 16-47 years (mean age 31.8 years) with CD4 T lymphocyte counts of 148-420 cells/mm3 attending clinics in General Hospital, Ikeja and private medical centres in Lagos Island, Nigeria and forty sex and age-matched apparently healthy controls were serologically examined as carriers of hepatitis B surface antigen (HBsAg) using a particle agglutination assay procedure (Sensitivity 94.5 - 100%, Serodia-HBs.PA, Fujirebio, Inc.). HBsAg was detected in 28 (51.9%) and 5 (12.5%) of the patients and controls respectively ( 2 Mantel-Haenszel = 13.8; P = 0.02). HBV co-infection was found to result in significant (P < 0.05) reduction in total lymphocyte count (1368.6 +/- 53.2 vs. 1590.5 +/- 80.4 cells/ mm3) with 7 of 10 (70%), 18 of 33 (54.5%) and 3 of 6 (50%) HIV-1 patients having < 200, 200 - 350 and > 350 CD4 lymphocyte cells/microl and eliciting HBsAg antigenemia. These patients exhibited 2.9 - 8.6% reduction in CD4 T lymphocyte counts compared to their seronegative counterparts. Although the liver function parameters measured in HIV-1 patients tested were higher than control values, significantly (P < 0.05) elevated liver enzymes: sGOT (44.1 +/- 2.2 vs. 26.2 +/- 2.1 IU/L), sGPT (46.2 +/- 2.4 vs. 23.5 +/- 1.8 IU/ L), and serum bilirubin levels (2.04 +/- 0.18 vs. 1.0 +/- 0.07 mg/ dL) were observed in HBsAg positive HIV-1 patients. sGOT or sGPT activity that was five times greater than the control was observed in 7(25%) and 2 (7.7%) of HbsAg positive and negative HIV-1 patients in whom significant association between decreased total lymphocyte count and measured liver parameters was found. We conclude that hepatitis infection deteriorates liver functions and its investigation in HIV-1 infected patients may be

  14. Planetary mission applications for space storable propulsion

    NASA Technical Reports Server (NTRS)

    Chase, R. L.; Cork, M. J.; Young, D. L.

    1974-01-01

    This paper presents the results of a study to compare space-storable with earth-storable spacecraft propulsion systems, space-storable with solid kick stages, and several space-storable development options on the basis of benefits received for cost expenditures required. The results show that, for a launch vehicle with performance less than that of Shuttle/Centaur, space-storable spacecraft propulsion offers an incremental benefit/cost ratio between 1.0 and 5.5 when compared to earth-storable systems for three of the four missions considered. In the case of VOIR 83, positive benefits were apparent only for a specific launch vehicle-spacecraft propulsion combination. A space-storable propulsion system operating at thrust of 600 lbf, 355 units of specific impulse, and with blowdown pressurization, represents the best choice for the JO 81 mission on a Titan/Centaur if only spacecraft propulsion modifications are considered. For still higher performance, a new solid-propellant kick stage with space-storable spacecraft propulsion is preferred over a system which uses space-storable propellants for both the kick stage and the spacecraft system.

  15. A portrait of the extreme solar system object 2012 DR30

    NASA Astrophysics Data System (ADS)

    Kiss, Cs.; Szabó, Gy.; Horner, J.; Conn, B. C.; Müller, T. G.; Vilenius, E.; Sárneczky, K.; Kiss, L. L.; Bannister, M.; Bayliss, D.; Pál, A.; Góbi, S.; Verebélyi, E.; Lellouch, E.; Santos-Sanz, P.; Ortiz, J. L.; Duffard, R.; Morales, N.

    2013-07-01

    2012 DR30 is a recently discovered solar system object on a unique orbit, with a high eccentricity of 0.9867, a perihelion distance of 14.54 AU, and a semi-major axis of 1109 AU, in this respect outscoring the vast majority of trans-Neptunian objects (TNOs). We performed Herschel/PACS and optical photometry to uncover the sizeand albedo of 2012 DR30, together with its thermal and surface properties. The body is 185 km in diameter and has a relatively low V-band geometric albedo of ~8%. Although the colours of the object indicate that 2012 DR30 is an RI taxonomy class TNO or Centaur, we detected an absorption feature in the Z-band that is uncommon among these bodies. A dynamical analysis of the target's orbit shows that 2012 DR30 moves on a relatively unstable orbit and was most likely only recently placed on its current orbit from the most distant and still highly unexplored regions of the solar system. If categorised on dynamical grounds 2012 DR30 is the largest Damocloid and/or high inclination Centaur observed so far. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  16. Giant comets and mass extinctions of life

    NASA Astrophysics Data System (ADS)

    Napier, W. M.

    2015-03-01

    I find evidence for clustering in age of well-dated impact craters over the last 500 Myr. At least nine impact episodes are identified, with durations whose upper limits are set by the dating accuracy of the craters. Their amplitudes and frequency are inconsistent with an origin in asteroid breakups or Oort cloud disturbances, but are consistent with the arrival and disintegration in near-Earth orbits of rare, giant comets, mainly in transit from the Centaur population into the Jupiter family and Encke regions. About 1 in 10 Centaurs in Chiron-like orbits enter Earth-crossing epochs, usually repeatedly, each such epoch being generally of a few thousand years' duration. On time-scales of geological interest, debris from their breakup may increase the mass of the near-Earth interplanetary environment by two or three orders of magnitude, yielding repeated episodes of bombardment and stratospheric dusting. I find a strong correlation between these bombardment episodes and major biostratigraphic and geological boundaries, and propose that episodes of extinction are most effectively driven by prolonged encounters with meteoroid streams during bombardment episodes. Possible mechanisms are discussed.

  17. A HYPOTHESIS FOR THE COLOR DIVERSITY OF THE KUIPER BELT

    SciTech Connect

    Brown, M. E.; Fraser, W. C.; Schaller, E. L.

    2011-10-01

    We propose a chemical and dynamical process to explain the surface colors of the Kuiper belt. In our hypothesis, the initial bulk compositions of the bodies themselves can be quite diverse-as is seen in comets-but the early surface compositions are set by volatile evaporation after the objects are formed. Strong gradients in surface composition, coupled with UV and particle irradiation, lead to the surface colors that are seen today. The objects formed in the inner part of the primordial belt retain only H{sub 2}O and CO{sub 2} as the major ice species on their surfaces. Irradiation of these species plausibly results in the dark neutrally colored centaurs and Kuiper belt objects (KBOs). Object formed further in the disk retain CH{sub 3}OH, which has been shown to lead to brighter redder surfaces after irradiation, as seen in the brighter redder centaurs and KBOs. Objects formed at the current location of the cold classical Kuiper belt uniquely retain NH{sub 3}, which has been shown to affect irradiation chemistry and could plausibly lead to the unique colors of these objects. We propose observational and experimental tests of this hypothesis.

  18. An overview of autonomous rendezvous and docking system technology development at General Dynamics

    NASA Technical Reports Server (NTRS)

    Kuenzel, Fred

    1991-01-01

    The Centaur avionics suite is undergoing a dramatic modernization for the commercial, DoD Atlas and Titan programs. The system has been upgraded to the current state-of-the-art in ring laser gyro inertial sensors and Mil-Std-1750A processor technology. The Cruise Missile avionic system has similarly been evolving for many years. Integration of GPS into both systems has been underway for over five years with a follow-on cruise missile system currently in flight test. Rendezvous and Docking related studies have been conducted for over five years in support of OMV, CTV, and Advanced Upper Stages, as well as several other internal IR&D's. The avionics system and AR&D simulator demonstrated to the SATWG in November 1990 has been upgraded considerably under two IR&D programs in 1991. The Centaur modern avionics system is being flown in block upgrades which started in July of 1990. The Inertial Navigation Unit will fly in November of 1991. The Cruise Missile avionics systems have been fully tested and operationally validated in combat. The integrated AR&D system for space vehicle applications has been under development and testing since 1990. A Joint NASA / GD ARD&L System Test Program is currently being planned to validate several aspects of system performance in three different NASA test facilities in 1992.

  19. The effects of the exhaust plume on the lightning triggering conditions for launch vehicles

    NASA Technical Reports Server (NTRS)

    Eriksen, Frederick J.; Rudolph, Terence H.; Perala, Rodney A.

    1991-01-01

    Apollo 12 and Atlas Centaur 67 are two launch vehicles that have experienced triggered lightning strikes. Serious consequences resulted from the events; in the case of Atlas Centaur 67, the vehicle and the payload were lost. These events indicate that it is necessary to develop launch rules which would prevent such occurrences. In order to develop valid lightning related rules, it is necessary to understand the effects of the plume. Some have assumed that the plume can be treated as a perfect conductor, and have computed electric field enhancement factors on that basis. The authors have looked at the plume, and believe that these models are not correct, because they ignore the fluid motion of the conducting plates. The authors developed a model which includes this flow character. In this model, the external field is excluded from the plume as it would be for any good conductor, but, in addition, the charge must distribute so that the charge density is zero at some location in the exhaust. When this condition is included in the calculation of triggering enhancement factors, they can be two to three times larger than calculated by other methods which include a conductive plume but don't include the correct boundary conditions. Here, the authors review the relevant features of rocket exhausts for the triggered lightning problem, present an approach for including flowing conductive gases, and present preliminary calculations to demonstrate the effect that the plume has on enhancement factors.

  20. Nuclear reactor power for a space-based radar. SP-100 project

    NASA Technical Reports Server (NTRS)

    Bloomfield, Harvey; Heller, Jack; Jaffe, Leonard; Beatty, Richard; Bhandari, Pradeep; Chow, Edwin; Deininger, William; Ewell, Richard; Fujita, Toshio; Grossman, Merlin

    1986-01-01

    A space-based radar mission and spacecraft, using a 300 kWe nuclear reactor power system, has been examined, with emphasis on aspects affecting the power system. The radar antenna is a horizontal planar array, 32 X 64 m. The orbit is at 61 deg, 1088 km. The mass of the antenna with support structure is 42,000 kg; of the nuclear reactor power system, 8,300 kg; of the whole spacecraft about 51,000 kg, necessitating multiple launches and orbital assembly. The assembly orbit is at 57 deg, 400 km, high enough to provide the orbital lifetime needed for orbital assembly. The selected scenario uses six Shuttle launches to bring the spacecraft and a Centaur G upper-stage vehicle to assembly orbit. After assembly, the Centaur places the spacecraft in operational orbit, where it is deployed on radio command, the power system started, and the spacecraft becomes operational. Electric propulsion is an alternative and allows deployment in assembly orbit, but introduces a question of nuclear safety.

  1. Is There Water on the Moon? NASA's LCROSS Mission

    NASA Technical Reports Server (NTRS)

    Noneman, Steven

    2007-01-01

    NASA is preparing for its return to the moon with the Lunar CRater Observation and Sensing Satellite (LCROSS) mission. This secondary payload spacecraft will travel with the Lunar Reconnaissance Orbiter (LRO) satellite to the Moon on the same Atlas-V 401 Centaur rocket launched from Cape Canaveral Air Force Station, Florida. The LCROSS mission will robotically seek to determine the presence of water ice at the Moon's South Pole. The 1000kg Secondary Payload budget is efficiently used to provide a highly modular and reconfigurable LCROSS Spacecraft with extensive heritage to accurately guide the expended Centaur into the crater. Upon separation, LCROSS flies through the impact plume, telemetering real-time images and characterizing water ice in the plume with infrared cameras and spectrometers. LCROSS then becomes a 700kg impactor itself, to provide a second opportunity to study the nature of the Lunar Regolith. LCROSS provides a critical ground-truth for Lunar Prospector and LRO neutron and radar maps, making it possible to assess the total lunar water inventory. This presentation contains a reference to video animation of the LCROSS mission that will be covered separately.

  2. Chimeric creatures in Greek mythology and reflections in science.

    PubMed

    Bazopoulou-Kyrkanidou, E

    2001-04-15

    "The Chimaera" in Homer's Iliad, "was of divine stock, not of men, in the forepart a lion, in the hinder a serpent, and in the midst a goat, ellipsis Bellerophon slew her, trusting in the signs of the gods." In Hesiod's Theogony it is emphasized that "Chimaera ellipsis had three heads, one of a grim-eyed lion, another of a goat, and another of a snakeellipsis". In addition to this interspecies animal chimera, human/animal chimeras are referred to in Greek mythology, preeminent among them the Centaurs and the Minotaur. The Centaurs, as horse/men, first appear in Geometric and early Archaic art, but in the literature not until early in the fifth century B.C. The bullheaded-man Minotaur, who is not certainly attested in the literary evidence until circa 500 B.C., first appears in art about 650 B.C. Attempts, in the fourth century B.C. and thereafter, to rationalize their mythical appearance were in vain; their chimeric nature retained its fascinating and archetypal form over the centuries. Early in the 1980s, experimental sheep/goat chimeras were produced removing the reproductive barrier between these two animal species. Late in the 1990s, legal, political, ethical, and moral fights loomed over a patent bid on human/animal chimeras. Chimeric technology is recently developed; however, the concept of chimerism has existed in literary and artistic form in ancient mythology. This is yet another example where art and literature precede scientific research and development.

  3. Mars Sample Return mission: Two alternate scenarios

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Two scenarios for accomplishing a Mars Sample Return mission are presented herein. Mission A is a low cost, low mass scenario, while Mission B is a high technology, high science alternative. Mission A begins with the launch of one Titan IV rocket with a Centaur G' upper stage. The Centaur performs the trans-Mars injection burn and is then released. The payload consists of two lander packages and the Orbital Transfer Vehicle, which is responsible for supporting the landers during launch and interplanetary cruise. After descending to the surface, the landers deploy small, local rovers to collect samples. Mission B starts with 4 Titan IV launches, used to place the parts of the Planetary Transfer Vehicle (PTV) into orbit. The fourth launch payload is able to move to assemble the entire vehicle by simple docking routines. Once complete, the PTV begins a low thrust trajectory out from low Earth orbit, through interplanetary space, and into low Martian orbit. It deploys a communication satellite into a 1/2 sol orbit and then releases the lander package at 500 km altitude. The lander package contains the lander, the Mars Ascent Vehicle (MAV), two lighter than air rovers (called Aereons), and one conventional land rover. The entire package is contained with a biconic aeroshell. After release from the PTV, the lander package descends to the surface, where all three rovers are released to collect samples and map the terrain.

  4. Mathematical and computational studies of the stability of axisymmetric annular capillary free surfaces

    NASA Technical Reports Server (NTRS)

    Albright, N.; Concus, P.; Karasalo, I.

    1977-01-01

    Of principal interest is the stability of a perfectly wetting liquid in an inverted, vertical, right circular-cylindrical container having a concave spheroidal bottom. The mathematical conditions that the contained liquid be in stable static equilibrium are derived, including those for the limiting case of zero contact angle. Based on these results, a computational investigation is carried out for a particular container that is used for the storage of liquid fuels in NASA Centaur space vehicles, for which the axial ratio of the container bottom is 0.724. It is found that for perfectly wetting liquids the qualitative nature of the onset of instability changes at a critical liquid volume, which for the Centaur fuel tank corresponds to a mean fill level of approximately 0.503 times the tank's radius. Small-amplitude periodic sloshing modes for this tank were calculated; oscillation frequencies or growth rates are given for several Bond numbers and liquid volumes, for normal modes having up to six angular nodes.

  5. Experimental Enhanced Upper Stage (XEUS): An affordable large lander system

    NASA Astrophysics Data System (ADS)

    Scotkin, J.; Masten, D.; Powers, J.; O'Konek, N.; Kutter, B.; Stopnitzky, B.

    The Experimental Enhanced Upper Stage (XEUS) offers a path to reduce costs and development time to sustainable activity beyond LEO by equipping existing large cryogenic propulsion stages with MSS VTVL propulsion and GNC to create a large, multi-thrust axis lander. Conventional lander designs have been driven by the assumption that a single, highly reliable, and efficient propulsion system should conduct the entire descent, approach, and landing. Compromises in structural, propulsion, and operational efficiency result from this assumption. System reliability and safety also suffer. The result is often an iterative series of optimizations, making every subsystem mission-unique and expensive. The XEUS multi-thrust axis lander concept uniquely addresses the programmatic and technical challenges of large-mass planetary landing by taking advantage of proven technologies and decoupling the deorbit and descent propulsion system from the landing propulsion system. Precise control of distributed, multi-thrust axis landing propulsion units mounted on the horizontal axis of a Centaur stage will ultimately enable the affordable deployment of large planetary rovers, uncrewed base infrastructure and manned planetary expeditions. The XEUS lander has been designed to offer a significantly improved mass fraction and mass to surface capability over conventional lander designs, while reducing airlock/payload to surface distances and distributing plume effects by using multiple gimbaled landing thrusters. In utilizing a proven cryogenic propulsion stage, XEUS reduces development costs required for development of new cryogenic propulsion stages and fairings and builds upon the strong heritage of successful Centaur and MSS RLV flights.

  6. Production of activated char from Illinois coal for flue gas cleanup

    USGS Publications Warehouse

    Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.

    1997-01-01

    Activated chars were produced from Illinois coal and tested in several flue gas cleanup applications. High-activity chars that showed excellent potential for both SO2 and NOx removal were prepared from an Illinois No. 2 bituminous coal. The SO2 (120 ??C) and NOx (25 ??C) removal performance of one char compared favorably with that of a commercial activated carbon (Calgon Centaur). The NOx removal performance of the same char at 120 ??C exceeded that of the Centaur carbon by more than 1 order of magnitude. Novel char preparation methods were developed including oxidation/thermal desorption and hydrogen treatments, which increased and preserved, respectively, the active sites for SO2 and NOx adsorption. The results of combined SO2/NOx removal tests, however, suggest that SO2 and NOx compete for similar adsorption sites and SO2 seems to be more strongly adsorbed than NO. A low-activity, low-cost char was also developed for cleanup of incinerator flue gas. A three-step method involving coal preoxidation, pyrolysis, and CO2 activation was used to produce the char from Illinois coal. Five hundred pounds of the char was tested on a slipstream of flue gas from a commercial incinerator in Germany. The char was effective in removing >97% of the dioxins and furans present in the flue gas; mercury levels were below detectable limits.

  7. Solar System Research with the Spacewatch 1.8-m Telescope

    NASA Technical Reports Server (NTRS)

    McMillan, Robert S.

    2001-01-01

    During this grant period, the 1.8-m Spacewatch telescope was put into routine operation to search for asteroids and comets ranging in location from near-Earth space to regions beyond the orbit of Neptune. All of these classes of objects can be detected simultaneously with our uniform scanning procedures. We are studying near Earth objects (NEOs), main belt asteroids, comets, Centaurs, and trans-Neptunian objects (TNOs), as well as the interrelationships of these classes and their bearing on the origin and evolution of the solar system. The Spacewatch 1.8-meter telescope is sensitive to V(mag) < 22.6 in sidereal scanning mode and is able to reach even fainter in longer 'staring' exposures, with a field of view 0.5 degrees square. These faint limits make the operation of the Spacewatch 1.8-m telescope complementary to asteroid surveys being done by other groups. Specifically, EAs smaller than 100 m in diameter and small main belt asteroids can be found, as well as more distant objects such as Centaurs/Scattered Disk Objects (SDOs) and TNOs. The 1.8-m telescope is also being used to do recoveries and astrometry of recently-discovered asteroids that subsequently become too faint for the other groups before good orbits are established.

  8. Solar System Observations with Spitzer Space Telescope: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.

    2005-01-01

    The programs of observations of Solar System bodies conducted in the first year of the operation of the Spitzer Space Telescope as part of the Guaranteed Observing Time allocations are described. Initial results include the determination of the albedos of a number of Kuiper Belt objects and Centaurs from observations of their flux densities at 24 and 70 microns, and the detection of emission bands in the spectra of several distant asteroids (Trojans) around 10 and 25 microns. The 10 Kuiper Belt objects observed to date have albedos in the range 0.08 - 0.15, significantly higher than the earlier estimated 0.04. An additional KBO [(55565) 2002 AW(sub l97)] has an albedo of 0.17 plus or minus 0.03. The emission bands in the asteroid spectra are indicative of silicates, but specific minerals have not yet been identified. The Centaur/comet 29P/Schwassmann-Wachmann 1 has a nucleus surface albedo of 0.025 plus or minus 0.01, and its dust production rate was calculated from the properties of the coma. Several other investigations are in progress as the incoming data are processed and analyzed.

  9. Altitude Wind Tunnel at NASA Glenn Research Center: An Interactive History

    NASA Technical Reports Server (NTRS)

    2008-01-01

    When constructed in the Early 1940s, the Altitude Wind Tunnel (AWT) at NASA Glenn Research Center was the nation's only wind tunnel capable of studying full scale engines under realistic flight conditions. It played a significant role in the development of the first U.S. jet engines as well as technologies such as the afterburner and variable-area nozzle. In the late 1950s, the tunnels interior components were removed so that hardware for Project Mercury could be tested in altitude conditions. In 1961, a portion of the tunnel was converted into one of the country's first large vacuum tanks and renamed the Space Power Chamber (SPC). SPC was used extensively throughout the 1960s for the Centaur rocket program. This multimedia piece allows one to interactively learn about the Altitude Wind Tunnel facility. and the research performed there. The piece contains: (1) A chronological history of the AWT from its construction during World War II and the testing of early jet engines, through the Mercury and Centaur programs of the 1960s and up to the final use of the building for the Microwave Systems laboratory. (2) Photographic surveys of the facility in it wind tunnel, vacuum tank and final configurations. (3) Browsable gallery of over 200 captioned photographs and video clips.(4) A nine minute documentary of the AWT produced by NASA in 1961 (5) Links to over 70 reports and publications related to AWT research and the history of the NACA.

  10. KSC-05PD-1259

    NASA Technical Reports Server (NTRS)

    2005-01-01

    KENNEDY SPACE CENTER, FLA. At the Cape Canaveral Air Force Station Skid Strip, a second stage Centaur (Block I) is rolled out of a Russian Antonov AH-124-100 cargo airplane. The Centaur will be mated with the Lockheed Martin Atlas V, designated AV- 007, that is the launch vehicle for the Mars Reconnaissance Orbiter (MRO). The MRO is designed for a series of global mapping, regional survey and targeted observations from a near- polar, low-altitude Mars orbit. These observations will be unprecedented in terms of the spatial resolution and coverage achieved by the orbiters instruments as they observe the atmosphere and surface of Mars while probing its shallow subsurface as part of a follow the water strategy. The orbiter is undergoing environmental tests in facilities at Lockheed Martin Space Systems in Denver, Colo., and is on schedule for a launch window that begins Aug. 10. Launch will be from Launch Complex 41 at Cape Canaveral Air Force Station in Florida.

  11. KSC-05PD-1258

    NASA Technical Reports Server (NTRS)

    2005-01-01

    KENNEDY SPACE CENTER, FLA. At the Cape Canaveral Air Force Station Skid Strip, a second stage Centaur (Block I) is rolled out of a Russian Antonov AH-124-100 cargo airplane. The Centaur will be mated with the Lockheed Martin Atlas V, designated AV- 007, that is the launch vehicle for the Mars Reconnaissance Orbiter (MRO). The MRO is designed for a series of global mapping, regional survey and targeted observations from a near- polar, low-altitude Mars orbit. These observations will be unprecedented in terms of the spatial resolution and coverage achieved by the orbiters instruments as they observe the atmosphere and surface of Mars while probing its shallow subsurface as part of a follow the water strategy. The orbiter is undergoing environmental tests in facilities at Lockheed Martin Space Systems in Denver, Colo., and is on schedule for a launch window that begins Aug. 10. Launch will be from Launch Complex 41 at Cape Canaveral Air Force Station in Florida.

  12. KSC-05PD-1257

    NASA Technical Reports Server (NTRS)

    2005-01-01

    KENNEDY SPACE CENTER, FLA. At the Cape Canaveral Air Force Station Skid Strip, a second stage Centaur (Block I) is ready to be offloaded from a Russian Antonov AH-124-100 cargo airplane. The Centaur will be mated with the Lockheed Martin Atlas V, designated AV-007, that is the launch vehicle for the Mars Reconnaissance Orbiter (MRO). The MRO is designed for a series of global mapping, regional survey and targeted observations from a near-polar, low-altitude Mars orbit. These observations will be unprecedented in terms of the spatial resolution and coverage achieved by the orbiters instruments as they observe the atmosphere and surface of Mars while probing its shallow subsurface as part of a follow the water strategy. The orbiter is undergoing environmental tests in facilities at Lockheed Martin Space Systems in Denver, Colo., and is on schedule for a launch window that begins Aug. 10. Launch will be from Launch Complex 41 at Cape Canaveral Air Force Station in Florida.

  13. KSC-05PD-1261

    NASA Technical Reports Server (NTRS)

    2005-01-01

    KENNEDY SPACE CENTER, FLA. Safely placed on a flat bed truck, the Centaur (Block I) is rolled away from Cape Canaveral Air Force Station Skid Strip where it landed aboard a Russian Antonov AH- 124-100 cargo airplane, seen at left. The upper stage Centaur will be mated with the Lockheed Martin Atlas V, designated AV- 007, that is the launch vehicle for the Mars Reconnaissance Orbiter (MRO). The MRO is designed for a series of global mapping, regional survey and targeted observations from a near- polar, low-altitude Mars orbit. These observations will be unprecedented in terms of the spatial resolution and coverage achieved by the orbiters instruments as they observe the atmosphere and surface of Mars while probing its shallow subsurface as part of a follow the water strategy. The orbiter is undergoing environmental tests in facilities at Lockheed Martin Space Systems in Denver, Colo., and is on schedule for a launch window that begins Aug. 10. Launch will be from Launch Complex 41 at Cape Canaveral Air Force Station in Florida.

  14. The size-distribution of scattering TNOs observed by La Silla - QUEST

    NASA Astrophysics Data System (ADS)

    Rabinowitz, David L.; Schwamb, M. E.; Hadjiyska, E.

    2013-10-01

    Now in its final year of operation, the La Silla - QUEST (LSQ) survey for distant solar-system objects [1] has covered most of the southern hemisphere to magnitude limit R = 21.4. The total number of detected TNOs and Centaurs exceeds 108, more than any other full-hemisphere survey of the outer system. These bodies have been found at distances ranging from 10 to 100 AU, at ecliptic latitudes ranging from 0 to 40 deg, and over a size range of 15 to 2500 km. Nearly all have well-determined orbits from observations covering wide arcs or multiple oppositions. The efficiency of the survey has also been well characterized, with careful attention to maintaining a constant level of sensitivity. Remarkably, the LSQ observations of actively scattering TNOs spans the ~100 km knee in the size distribution which has been difficult for smaller-area, deeper surveys to detect. The results of the LSQ survey thus present a unique opportunity to constrain the total number and size distribution of the Centaurs and their likely parent population at the same time. Here we present preliminary results for the R-band absolute magnitude distribution of the actively scattering TNOs and discuss the implications for the existence of a "divot" at ~100 km as reported by Shankman et al [2]. [1] Rabinowitz, D. et al. 2012, AJ, 144, 140; [2] Shankman, C. et al. 2013, ApJ, 764, 2

  15. WATER ICE IN THE KUIPER BELT

    SciTech Connect

    Brown, M. E.; Fraser, W. C.; Schaller, E. L.

    2012-06-15

    We examine a large collection of low-resolution near-infrared spectra of Kuiper Belt objects (KBOs) and centaurs in an attempt to understand the presence of water ice in the Kuiper Belt. We find that water ice on the surface of these objects occurs in three separate manners: (1) Haumea family members uniquely show surfaces of nearly pure water ice, presumably a consequence of the fragmentation of the icy mantle of a larger differentiated proto-Haumea; (2) large objects with absolute magnitudes of H < 3 (and a limited number to H = 4.5) have surface coverings of water ice-perhaps mixed with ammonia-that appears to be related to possibly ancient cryovolcanism on these large objects; and (3) smaller KBOs and centaurs which are neither Haumea family members nor cold-classical KBOs appear to divide into two families (which we refer to as 'neutral' and 'red'), each of which is a mixture of a common nearly neutral component and either a slightly red or very red component that also includes water ice. A model suggesting that the difference between neutral and red objects due to formation in an early compact solar system either inside or outside, respectively, of the {approx}20 AU methanol evaporation line is supported by the observation that methanol is only detected on the reddest objects, which are those which would be expected to have the most of the methanol containing mixture.

  16. Hepatitis-B virus infection in anaesthetists.

    PubMed

    Carstens, J; Macnab, G M; Kew, M C

    1977-09-01

    To determine whether anaesthetists are at risk from developing hepatitis-B virus (HBV) infection from their patients, 95 anaesthetists working with black South Africans (who have a high prevalence of hepatitis-B antigenaemia) were questioned about attacks of viral hepatitis and their blood was tested for hepatitis-B (surface) antigen (HBsAg) and antibody (Anti-HBs). Anti-HBs was detected in the serum of 17.9% of the anaesthetists, but none was a chronic carrier of HBsAg. Two anaesthetists had suffered from acute viral hepatitis during their careers, one of whom is now positive for Anti-HBs. Forty-five of the anaesthetists (47.4%) were known to have anaesthetized patients with HBs antigenaemia, and of these seven were Anti-HBs-positive. Anaesthetists working with a population having a high carrier rate of HBV appear to be more at risk from HBV infection than the general population. PMID:911589

  17. Complement activation in chronic liver disease.

    PubMed Central

    Munoz, L E; De Villiers, D; Markham, D; Whaley, K; Thomas, H C

    1982-01-01

    Patients with HBsAg positive chronic active liver disease (CALD) and primary biliary cirrhosis (PBC) exhibit increased C3d concentrations and changes in the serum concentrations of the complement components consistent with activation of the classical and alternative pathways. In these patients the concentrations of the regulatory proteins, C3b inactivator (C3bINA) and beta IH globulin, are normal. Patients with HBsAg negative CALD and alcohol induced liver disease (ALD) exhibit no evidence of an increased level of complement system activation. In these patients diminished serum concentrations of complement components appear to be related to diminished hepatic synthetic function. C4 synthesis may be specifically reduced in autoimmune chronic active liver disease. PMID:7083631

  18. Biotin avidin amplified magnetic immunoassay for hepatitis B surface antigen detection using GoldMag nanoparticles

    NASA Astrophysics Data System (ADS)

    Yu, An; Geng, Tingting; Fu, Qiang; Chen, Chao; Cui, Yali

    2007-04-01

    Using GoldMag (Fe3O4/Au) nanoparticles as a carrier, a biotin-avidin amplified ELISA was developed to detect hepatitis B surface antigen (HBsAg). A specific antibody was labeled with biotin and then used to detect the antigen with an antibody coated on GoldMag nanoparticles by a sandwich ELISA assay. The results showed that 5 mol of biotin were surface bound per mole of antibody. The biotin-avidin amplified ELISA assay has a higher sensitivity than that of the direct ELISA assay. There is 5-fold difference between HBsAg positive and negative serum even at dilution of 1:10000, and the relative standard deviation of the parallel positive serum at dilution of 1:4000 is 5.98% (n=11).

  19. [Prevalence of HBs antigen carriage in a population of national Gendarmerie recruits in Ivory Coast in 2008].

    PubMed

    Kra, O; N'dri, N; Ouattara, B; Kadjo, K; Aba, T; Bissagnéné, E

    2012-01-01

    The purpose of this study was to determine the prevalence of HBsAg carriage in Ivorian gendarmerie recruits in 2008. This prevalence was 15.6%. It was highest in recruits aged 18 years (24%), in those who were married (33.3%) and in those who had had more than three sexual partners in the 6 months before the survey (19.4%). It was also higher in recruits who had never used condoms (20.6%) and in those who had undergone blood transfusions (27%). A policy of vaccination against HBV in the army, in teenagers and adults must be implemented to reduce HBsAg carriage in the army and in the Ivorian population.

  20. Hepatitis B infection in Vietnam: current issues and future challenges.

    PubMed

    Nguyen, Van T T

    2012-03-01

    Hepatitis B virus (HBV) infection remains a major public health problem in Vietnam. Recent studies have found that prevalence of current HBV infection (HBsAg+) ranges from 10% to 20% in the general population and 20% to 40% among injecting drug users and HIV+ patients. However, HBV prevention and control in Vietnam relies heavily on universal infant vaccination program and HBsAg screening for blood donors. Currently, HBV prevention and control is underfunded by the government and receives little support from international agencies. HBV-related liver disease will continue to create a heavy burden for public health in Vietnam in the next several decades unless appropriate interventions are undertaken urgently. Establishment of a national strategy for HBV prevention and control is crucial to develop and implement effective interventions.

  1. Genetic variation of occult hepatitis B virus infection

    PubMed Central

    Zhu, Hui-Lan; Li, Xu; Li, Jun; Zhang, Zhen-Hua

    2016-01-01

    Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare. PMID:27053845

  2. Studies on the disposable obstetrical dressings sterilized by radiation and the effect of its application

    NASA Astrophysics Data System (ADS)

    Haiqiao, Wang; Sujing, Sun

    1993-10-01

    In order to attain an optimum sterilization treatment to obstetric dressings, a new product made by us, with 60Coγ-ray, the effects of radiation on standard bacteria pseudomonas aeruginosa ATcc27853, Escherichia coli ATcc25922, Staphylococcus aureus ATcc25923, Clostridium PB6KA, short Bacillus E60163202 and HBSAg were studied. Results showed that at the absorbed dose of 10 kGy, all the bacteria, bacillus and HBSAg were killed off, and sterilized with the dose, the dressings can completely accord with the demands of hygiene, which was further confirmed by microbiological and poisonous tests and the effects of clinical application. In Nov. 1988, the dressings was awarded the excellent prize in the 1st international exhibition of patent, new technique and new equipment in Guangzhou; its effective application is also reported in the paper.

  3. Prevalence of hepatitis B and C virus infections and their related risk factors in Libya: a national seroepidemiological survey.

    PubMed

    Elzouki, A-N; Smeo, M-N; Sammud, M; Elahmer, O; Daw, M; Furarah, A; Abudher, A; Mohamed, M K

    2013-07-01

    A high prevalence of hepatitis B (HBV) and C virus (HCV) infections has been reported among specific patient groups in Libya; a survey was thus designed to determine the extent of the problem at the national level. A multi-stage sampling design covering all administrative areas of Libya was applied, covering > 65,000 individuals of all age groups. All subjects gave a blood sample and completed a questionnaire on demographic and risk behaviour data. The prevalence of HBV surface antigen (HBsAg) and anti-HCV were 2.2% and 1.3% respectively. The prevalence of anti-HCV increased with age, rising gradually after age 30 years, in contrast to a stable prevalence of HBsAg in all age groups 10+ years. Age-adjusted risk factors for HCV infection were previous hospitalization, surgical operations, previous blood transfusions and intravenous drug use; for HBV infection only family exposure or contact with HBV case were identified.

  4. Clearing Persistent Extracellular Antigen of Hepatitis B Virus: An Immunomodulatory Strategy To Reverse Tolerance for an Effective Therapeutic Vaccination.

    PubMed

    Zhu, Danming; Liu, Longchao; Yang, Dan; Fu, Sherry; Bian, Yingjie; Sun, Zhichen; He, Junming; Su, Lishan; Zhang, Liguo; Peng, Hua; Fu, Yang-Xin

    2016-04-01

    Development of therapeutic vaccines/strategies to control chronic hepatitis B virus (HBV) infection has been challenging because of HBV-induced tolerance. In this study, we explored strategies for breaking tolerance and restoring the immune response to the HBV surface Ag in tolerant mice. We demonstrated that immune tolerance status is attributed to the level and duration of circulating HBsAg in HBV carrier models. Removal of circulating HBsAg by a monoclonal anti-HBsAg Ab in tolerant mice could gradually reduce tolerance and reestablish B cell and CD4(+) T cell responses to subsequent Engerix-B vaccination, producing protective IgG. Furthermore, HBsAg-specific CD8(+) T cells induced by the addition of a TLR agonist resulted in clearance of HBV in both serum and liver. Thus, generation of protective immunity can be achieved by clearing extracellular viral Ag with neutralizing Abs followed by vaccination.

  5. Risk and prophylaxis strategy of hepatitis B virus reactivation in patients with lymphoma undergoing chemotherapy with or without rituximab.

    PubMed

    Pei, Sung-Nan; Chen, Chien-Hung

    2015-06-01

    Hepatitis B virus (HBV) reactivation is a serious but preventable complication for patients with lymphoma receiving systemic therapy. Without antiviral prophylaxis, the HBV reactivation rate is estimated to be > 50% in patients who are positive for hepatitis B surface antigen (HBsAg), and fatal hepatic failure is not uncommon. Current guidelines suggest that routine antiviral prophylaxis should be administered to all HBsAg-positive patients until 6-12 months after completion of chemotherapy. For those who are negative for HBsAg and positive for hepatitis B core antibody, HBV reactivation is uncommon when a conventional dose of chemotherapy is administered. However, with rituximab-containing immunochemotherapy, the HBV reactivation rate is 18% and the clinical course can vary from asymptomatic viremia to fulminant hepatic failure that can be potentially fatal. In this review, we discuss the risk, clinical course and prophylactic strategy of HBV reactivation in patients with lymphoma treated with chemotherapy with or without rituximab.

  6. Prevalence, correlates and pattern of Hepatitis B among antenatal clinic attenders in Yaounde-Cameroon: is perinatal transmission of HBV neglected in Cameroon?

    PubMed Central

    2013-01-01

    Background Few studies have evaluated the prevalence of HBV in the general Cameroonian population or among antenatal attendants. The aim of this study was to determine the prevalence, correlates and patterns of Hepatitis B surface antigen among pregnant women attending antenatal care in Yaounde-Cameroon. Methods This was a cross-sectional multicenter study carried out in a referral hospital and two secondary hospitals in Yaounde, the capital of Cameroon. The study lasted 15 months (March 2011 to June 2012), and recruited 959 pregnant women. Patient recruitment was consecutive. The HBsAg was tested using the Monalisa HBsAg Ultra ELISA kit. Other hepatitis B markers were equally tested. We used the statistical package for social sciences (SPSS) version 14.0 software to conduct a quantitative analysis of the derived data. Simple descriptive statistics such as means, standard deviations, and proportions were used to describe the data. We tested for association in categorical variables using the chi-squared (χ2) test. The odds ratio (OR) and the corresponding 95% confidence intervals (95% CI) were used to summarise the strength of association between specific binary exposure and outcome variables. The level of statistical significance for the study was set at p < 0.05. Results The prevalence of hepatitis B infection (HBsAg) among antenatal clinic attenders in our setting was 7.7%. Amongst these women, just 5.4% were previously aware of their HBsAg status. The rate of HBV infectivity was high, with 28% of HBsAg positive women having evidence of HBeAg in their plasma, and up to 45.8% of these women lacking antibodies against hepatitis B e antigen (anti-HBe). About 41% of the pregnant women had had previous contact with HBV as evidenced by the positive status for anti-HBc. Just 2.7% of the pregnant women had previously been vaccinated against HBV. The mean age for HBsAg positivity in our setting was 26.9 ±4.7 years, and the most affected age group was the 25 – 29

  7. Screening for transfusion transmissible infections using rapid diagnostic tests in Africa: a potential hazard to blood safety?

    PubMed

    Prugger, C; Laperche, S; Murphy, E L; Bloch, E M; Kaidarova, Z; Tafflet, M; Lefrère, J-J; Jouven, X

    2016-02-01

    Rapid diagnostic tests (RDTs) are routinely used in African blood centres. We analysed data from two cross-sectional studies representing 95 blood centres in 29 African countries. Standardized panels of sera containing varying concentrations of anti-human immunodeficiency virus (HIV) antibodies (Ab), hepatitis B virus antigen (HBsAg) and antihepatitis C virus (HCV) Ab were screened using routine operational testing procedures at the centres. Sensitivity of detection using RDTs was high for HIV Ab-positive samples, but low for intermediately HBsAg (51·5%) and HCV Ab (40·6%)-positive samples. These findings suggest that current RDT use in Africa could pose a hazard to blood safety. PMID:26646317

  8. Production of highly concentrated, heat stable hepatitis B surface antigen in maize

    PubMed Central

    Hayden, Celine A.; Egelkrout, Erin M.; Moscoso, Alessa M.; Enrique, Cristina; Keener, Todd K.; Jimenez-Flores, Rafael; Wong, Jeffrey C.; Howard, John A.

    2012-01-01

    Summary Plant-based oral vaccines are a promising emergent technology that could help alleviate disease burden worldwide by providing a low-cost, heat stable, oral alternative to parenterally administered commercial vaccines. Here we describe high-level accumulation of the hepatitis B surface antigen (HBsAg) at a mean concentration of 0.51%TSP in maize T1 seeds using an improved version of the globulin1 promoter. This concentration is more than four-fold higher than any previously reported lines. HBsAg expressed in maize seeds was extremely heat stable, tolerating temperatures up to 55°C for one month without degradation. Optimal heat stability was achieved after oil extraction of ground maize material, either by supercritical fluid extraction or hexane treatment. The contributions of this material towards the development of a practical oral vaccine delivery system are discussed. PMID:22816734

  9. Serologic and molecular characteristics of hepatitis B virus among school children in East Java, Indonesia.

    PubMed

    Utsumi, Takako; Yano, Yoshihiko; Lusida, Maria Inge; Amin, Mochamad; Soetjipto; Hotta, Hak; Hayashi, Yoshitake

    2010-07-01

    Universal childhood hepatitis B vaccination was introduced in Indonesia in 1997; by 2008, coverage was estimated to be 78%. This study aimed to investigate the serologic status and virologic characteristics of hepatitis B virus (HBV) among the children in East Java. A total of 229 healthy children born during 1994-1999 were enrolled in this study. Overall, 3.1% were positive for hepatitis B surface antigen (HBsAg) and 23.6% were positive for antibody to HBsAg (anti-HBs). HBV DNA was detected in 5 of 222 HBsAg-negative carriers, which were suggested to be cases of occult HBV infection. A single amino substitution (T126I) in the S region was frequently found. HBV infection remains endemic, and the prevalence of anti-HBs remains insufficient among children in East Java, Indonesia.

  10. Synthesis and biological evaluation of nucleoside analogues than contain silatrane on the basis of the structure of acyclovir (ACV) as novel inhibitors of hepatitis B virus (HBV).

    PubMed

    Han, Anyue; Li, Lingna; Qing, Kuiyou; Qi, Xiaolu; Hou, Leping; Luo, Xintong; Shi, Shaohua; Ye, Faqing

    2013-03-01

    Hepatitis B virus (HBV) infection causes major public health problems worldwide. Acyclovir (ACV) is mainly used to inhibit herpes simplex virus (HSV) rather than HBV. In this study, we used the combination principle to design and synthesize nucleoside analogues that contain silatrane on the basis of the structure of ACV. We found that the compounds were effective inhibitors of HBV, both in vitro and in vivo. All of the compounds showed suppressive activity on the expression of HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) in the HepG2.2.15 cell line with low cytotoxicity. One of compounds was studied in HBV transgenic mice model, and the test results showed its ability to reduce the levels of HBsAg, HBeAg and HBV DNA by ELASE and qPCR. Furthermore, significant improvement of T lymphocyte was observed after treatment, as evaluated by flow cytometry (FCM).

  11. Successful hepatitis B vaccination in patients who underwent transplantation for hepatitis B virus-related cirrhosis: preliminary results.

    PubMed

    Bienzle, Ulrich; Günther, Matthias; Neuhaus, Ruth; Neuhaus, Peter

    2002-06-01

    Long-term hepatitis B immunoglobulin (HBIg) prophylaxis prevents endogenous hepatitis B virus (HBV) reinfection in the majority of liver transplant recipients. Active hepatitis B vaccination after orthotopic liver transplantation (OLT) in these patients has produced conflicting results to date. On this study, patients who remained hepatitis B surface antigen (HBsAg) negative with passive immunization after OLT for HBV cirrhosis were actively immunized using recombinant HBV antigen (Engerix), together with a novel adjuvant system (monophosphoryl lipid A and a natural saponine molecule). This led to a sustained antibody response to HBsAg (>500 IU/L) in 5 of 10 patients. This antibody response prevented reinfection and allowed termination of prophylactic HBIg substitution for more than 12 months in these patients. PMID:12037789

  12. Effects of He-Ne laser acupuncture-point irradiation on serology hepatitis virus markers in chronic hepatitis B

    NASA Astrophysics Data System (ADS)

    Wang, Yue-lan; Huang, Bing-chen; Ni, Liu-da

    1993-03-01

    For most of the patients with chronic hepatitis B the immunologic function is deficient. Immunopotentiation and immunoregulation can be used as effective treatments. Laser irradiation can potentiate the cellular immune function of the human body and has good effects on improving clinical symptoms, cutting short the process of diseases, and promoting HBsAg negative change. Thereby we have a randomized opportunity to study the effect of He-Ne laser acupoint irradiation on serological HBV markers (HBVM) in chronic hepatitis B (CHB).

  13. Medical practices for prevention of perinatal infections in Puerto Rico.

    PubMed

    Dayan, Gustavo H; Caquías, Carmen Rodríguez; García, Yaniré; Malik, Tasneem; Copeland, John; Bi, Daoling; Reef, Susan

    2008-01-01

    Recommendations for screening for maternal infections and interventions to prevent disease in the fetus or newborn have been in place in Puerto Rico for more than 10 years. However, compliance with these recommendations has not been widely documented. We evaluated compliance with rubella/hepatitis B prenatal screening and vaccination recommendations, assessed hospital screening practices for syphilis and HIV, and determined risk factors for suboptimal prenatal care. Records of a random, stratified sample of 2003 pregnant women delivering in eight maternity hospitals in Puerto Rico in 2002 were reviewed. Obstetric prenatal and postnatal records were also reviewed when rubella/hepatitis B surface antigen (HBsAg) screening was not available at the hospital, and to document rubella postpartum vaccination (PPV). Prenatal screening rates were 98.4% for rubella and 98.8% for HBsAg. Overall, 5.4% [95% CI 4.4, 6.5] of women were susceptible to rubella. No eligible women received rubella PPV at the hospital and only 1.5% had documented rubella vaccine prescription at the obstetric records. Only one woman was found to be HBsAg positive and her newborn was adequately treated. However, only 0.9% newborns born to mothers with unknown HBsAg status received hepatitis B vaccine. Screening was documented in 85.7% of the hospital records for HIV and 87.9% for syphilis. Suboptimal prenatal care was more likely among teenagers, low-educated women, and women with >3 previous pregnancies. Screening rates for rubella and hepatitis B were high; however, implementation of recommendations for prevention of rubella and hepatitis B needs to be improved. PMID:18173782

  14. Seroprevalence and associated risk factors of hepatitis B virus among pregnant women in southern Ethiopia: a hospital-based cross-sectional study

    PubMed Central

    Metaferia, Yeshi; Dessie, Walelign; Ali, Ibrahim

    2016-01-01

    OBJECTIVES: Hepatitis B virus (HBV) is a major blood-borne and sexually transmitted infectious agent that is a significant global public health issue. The aim of this study was to determine the seroprevalence and risk factors of HBV among pregnant women attending the antenatal clinic of the Hawassa University referral hospital in Ethiopia. METHODS: A cross-sectional study was conducted from April to May, 2015. A total of 269 consecutive pregnant women attending antenatal consultations were enrolled. Sociodemographic information and data regarding possible risk factors were collected using a structured questionnaire. Hepatitis B surface antigen (HBsAg) screening was performed using an enzyme-linked immunosorbent assay, and the data were analyzed. RESULTS: The overall seroprevalence of HBsAg among the 269 participants enrolled in the study was 7.8% (n=21). The prevalence of human immunodeficiency virus (HIV) infection was 5.2% (n=14), of whom two participants (14.2%) were also positive for HBsAg. Study participants with no formal education (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.27 to 10.68; p<0.05) were more likely to be infected with HBV than those who had completed at least secondary school. Although HBsAg was detected more often in pregnant women who had multiple exposure factors (8.8%, n=13) than in pregnant women who had not experienced possible risk factors (4%, n=1), this difference was not statistically significant (OR, 2.33; 95%CI, 0.29 to 18.63). CONCLUSIONS: A high prevalence of HBV infection was detected in the study population. Neither the type of risk factors nor exposure to multiple risk factors was significantly associated with HBV infection. Hence, screening pregnant women regardless of risk factors and improving awareness of the transmission routes of HBV within this group may reduce the risk of HBV infections. PMID:27336446

  15. A rapid and sensitive method based on magnetic beads for the detection of hepatitis B virus surface antigen in human serum.

    PubMed

    Ren, Zhi-Qi; Liu, Tian-Cai; Hou, Jing-Yuan; Chen, Mei-Jun; Chen, Zhen-Hua; Lin, Guan-Feng; Wu, Ying-Song

    2014-09-01

    Current clinically assays, such as enzyme-linked immunosorbent assay and chemiluminescence immunoassay, for hepatitis B surface antigen (HBsAg) are inferior in terms of either sensitivity and accuracy or rapid and high-throughput analysis. A novel assay based on magnetic beads and time-resolved fluoroimmunoassay was developed for the quantitative determination of HBsAg in human serum. HBsAg was captured using two types of anti-HBsAg monoclonal antibodies (B028, S015) immobilized on to magnetic beads and detected using europium-labeled anti-HBsAg polyclonal detection antibody. Finally, the assay yielded a high sensitivity (0.02 IU/mL) and a wide dynamic range (0.02-700 IU/mL) for HBsAg when performed under optimal conditions. Satisfactory accuracy, recovery and specificity were also demonstrated. The intra- and interassay coefficients of variation were 4.7-8.7% and 3.8-7.5%, respectively. The performance of this assay was further assessed against a well-established commercial chemiluminescence immunoassay kit with 399 clinical serum samples. It was revealed that the test results for the two methods were in good correlation (Y = 1.182X - 0.017, R = 0.989). In the current study, we demonstrated that this novel time-resolved fluoroimmunoassay could be used: as a highly sensitive, automated and high-throughput immunoassay for the diagnosis of acute or chronic hepatitis B virus infection; for the screening of blood or organ donors; and for the surveillance of persons at risk of acquiring or transmitting hepatitis B virus.

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

    ERIC Educational Resources Information Center

    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:…

  17. Prevalence of hepatitis B and C infections in rheumatoid arthritis and ankylosing spondylitis: A multicenter countrywide study

    PubMed Central

    Yılmaz, Neslihan; Karadağ, Ömer; Kimyon, Gezmiş; Yazıcı, Ayten; Yılmaz, Sema; Kalyoncu, Umut; Kaşifoğlu, Timuçin; Temiz, Hakan; Baysal, Birol; Tözün, Nurdan

    2014-01-01

    Objective Immunosuppressive therapies, especially tumor necrosis factor-α inhibitors, are frequently used in treatment of rheumatoid arthritis (RA) and ankylosing spondylitis (AS). These therapies can induce viral reactivation in concurrent hepatitis B virus (HBV)- or hepatitis C virus (HCV)-positive patients. On the other hand, the prevalence of HBV and HCV infections is not exactly known in RA and AS patients. The aim of this study was to investigate the prevalence of HBV and HCV infections in RA and AS patients. Material and Methods A group of 1517 RA and 886 AS consecutive patients followed by six different rheumatology outpatient clinics of Turkey were recruited in this study. The prevalence of HBV surface antigen (HBsAg) and HCV antibody (anti-HCV) were retrospectively investigated. Results The mean age was 49.0±13.2 years in RA and 37.3±10.5 years in AS patients. HBsAg prevalence was 35 (2.3%) in RA and 27 (3%) in AS patients. Anti-HCV prevalence was 17 (1.1%) and 10 (1.1%), respectively. In the RA group, both HBsAg and anti-HCV positive patients were older than negative ones (p<0.05), and the highest prevalence was found in those 60–69 years (p<0.05). Conclusion In previous national data, the prevalence of HBsAg has been reported as 3.99% and shown to increase with age. In this study we have found a lower HBV infection prevalence in both RA and AS patients according to Turkish national data. This result may explain by being younger age of our patients. In another conclusion, lower prevalence could be related to, joint complaints may less consulted to Rheumatologist in HBV positive.

  18. Synthesis of antibodies to hepatitis B virus by cultured lymphocytes from chronic hepatitis B surface antigen carriers

    SciTech Connect

    Dusheiko, G.M.; Hoofnagle, J.H.; Cooksley, W.G.; James, S.P.; Jones, E.A.

    1983-05-01

    It has been postulated that host immune defects are responsible for the development and persistence of the hepatitis B surface antigen (HBsAg) carrier state. The synthesis of both anti-HBs and antibody to hepatitis B core antigen (anti-HBc) in cultures containing peripheral blood mononuclear cells from chronic HBsAg carriers and from control (antibody-positive) patients was measured in the presence of pokeweed mitogen. Similar amounts of polyclonal IgG and IgM were synthesized by cultures containing lymphocytes from chronic carriers and controls. Anti-HBc was detectable in lymphocyte supernatants from 2 of 20 controls and from 21 of 29 carriers. The presence of anti-HBc synthesis in vitro correlated with high serum titers of anti-HBc. In contrast, anti-HBs was detected in lymphocyte supernatants from 6 of 20 controls (predominantly in those who had high serum titers of anti-HBs) but in none of the supernatants from 29 HBsAg carriers. Co-culture experiments were performed using T and B lymphocyte fractions that had been purified by affinity chromatography. B lymphocytes from carriers co-cultured with allogeneic irradiated (''helper'') T lymphocytes from controls synthesized normal amounts of IgG, IgM, and anti-HBc but still did not synthesize detectable amounts of anti-HBs. In the converse experiments, B lymphocytes from controls were co-cultured with irradiated T lymphocytes from carriers. The T lymphocytes from 16 of 24 carriers augmented anti-HBs production by control B cells normally, the remaining eight did not. Finally, mixtures of control B cells and control irradiated T lymphocytes were co-cultured with T lymphocytes from chronic HBsAg carriers. 5 of 12 carriers demonstrated active suppression of anti-HBs production, and in three this suppression was specific, as IgG and IgM production remained normal.

  19. Mutations Associated With Occult Hepatitis B in HIV-Positive South Africans

    PubMed Central

    Powell, Eleanor A.; Gededzha, Maemu P.; Rentz, Michael; Rakgole, Nare J.; Selabe, Selokela G.; Seleise, Tebogo A.; Mphahlele, M. Jeffrey; Blackard, Jason T.

    2015-01-01

    Occult hepatitis B is characterized by the absence of hepatitis B surface antigen (HBsAg) but the presence of HBV DNA. Because diagnosis of hepatitis B virus (HBV) typically includes HBsAg detection, occult HBV remains largely undiagnosed. Occult HBV is associated with increased risk of hepatocellular carcinoma, reactivation to chronic HBV during immune suppression, and transmission during blood transfusion and liver transplant. The mechanisms leading to occult HBV infection are unclear, although viral mutations are likely a significant factor. In this study, sera from 394 HIV-positive South Africans were tested for HBV DNA and HBsAg. For patients with detectable HBV DNA, the overlapping surface and polymerase open reading frames (ORFs) were sequenced. Occult-associated mutations—those mutations found exclusively in individuals with occult HBV infection but not in individuals with chronic HBV infection from the same cohort or GenBank references—were identified. Ninety patients (22.8%) had detectable HBV DNA. Of these, 37 had detectable HBsAg, while 53 lacked detectable surface antigen. The surface and polymerase ORFs were cloned successfully for 19 patients with chronic HBV and 30 patients with occult HBV. In total, 235 occult-associated mutations were identified. Ten occult-associated mutations were identified in more than one patient. Additionally, 15 amino acid positions had two distinct occult-associated mutations at the same residue. Occult-associated mutations were common and present in all regions of the surface and polymerase ORFs. Further study is underway to determine the effects of these mutations on viral replication and surface antigen expression in vitro. PMID:25164924

  20. Hepatitis B Virus Screening for Patients With Cancer Before Therapy: American Society of Clinical Oncology Provisional Clinical Opinion Update

    PubMed Central

    Hwang, Jessica P.; Somerfield, Mark R.; Alston-Johnson, Devena E.; Cryer, Donna R.; Feld, Jordan J.; Kramer, Barnett S.; Sabichi, Anita L.; Wong, Sandra L.; Artz, Andrew S.

    2015-01-01

    Purpose This updated provisional clinical opinion presents a revised opinion based on American Society of Clinical Oncology panel consensus in the context of an evolving database. Context Despite the 2010 provisional clinical opinion recommendation, there is still evidence of suboptimal hepatitis B virus (HBV) screening among patients at high risk for HBV infection or HBV reactivation after chemotherapy. This updated provisional clinical opinion introduces a risk-adaptive strategy to identify and treat patients with HBV infection to reduce their risk of HBV reactivation. Provisional Clinical Opinion Medical providers should screen by testing patients for HBV infection before starting anti-CD20 therapy or hematopoietic cell transplantation. Providers should also screen patients with risk factors for HBV infection. Screening should include both hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc), because reactivation can occur in patients who are HBsAg positive/anti-HBc positive or HBsAg negative/anti-HBc positive. Either total anti-HBc or anti-HBc immunoglobulin G (not immunoglobulin M) test should be used. Clinicians should start antiviral therapy for HBsAg-positive/anti-HBc–positive patients before or contemporaneously with cancer therapy and monitor HBsAg-negative/anti-HBc–positive patients for reactivation with HBV DNA and ALT levels, promptly starting antivirals if reactivation occurs. Clinicians can initiate antivirals for HBsAg-negative/anti-HBc–positive patients anticipating cancer therapies associated with a high risk of reactivation, or they can monitor HBV DNA and ALT levels and initiate on-demand antivirals. For patients who neither have HBV risk factors nor anticipate cancer therapy associated with a high risk of reactivation, current evidence does not support HBV screening before initiation of cancer therapy. Two panel members provided a minority viewpoint, involving a strategy of universal HBsAg and selective anti