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Sample records for advia centaur hbsag

  1. Evaluation of the automated ADVIA centaur® XP syphilis assay for serological testing.

    PubMed

    Saw, Sharon; Zhao, Huiqin; Tan, Phyllis; Saw, Betty; Sethi, Sunil

    2017-02-20

    We evaluated the performance of the ADVIA Centaur XP Syphilis assay (Siemens Healthcare Diagnostics, Tarrytown, NY, USA) using samples previously tested on the ARCHITECT i4000SR system (Abbott Diagnostics, Lake Forest, IL, USA) and confirmed by the Treponema pallidum particle agglutination assay (TPPA) (SERODIA-TPPA, Fujirebio Diagnostics Inc., Malvern, PA, USA). Clinical patient information was included to aid resolution of discordant samples where available. Precision, interference, and cross-reactivity were also assessed. Relative to patient clinical status, the sensitivity of both the ADVIA Centaur XP and the ARCHITECT assays was 100% (95% CI, 93.9-100), and the specificity of the ADVIA Centaur XP assay was 95.5% (95% CI, 90.4-98.3), which was slightly higher than that of the ARCHITECT assay at 93.9% (95% CI, 88.4-97.3). Overall agreement relative to patient clinical status was 96.9% (95% CI, 93.3-98.8) for the ADVIA Centaur XP assay and 95.8% (95% CI, 91.9-98.2) for the ARCHITECT assay. Overall agreement between the two automated assays was 96.9% (95% CI, 93.3-98.8). ADVIA Centaur XP assay precision was <5% at all index values tested. No significant interference was observed for lipemia or hemolysis; a small effect was seen with some samples for bilirubin. The assay exhibited no significant cross-reactivity with a number of potential interfering factors. The ADVIA Centaur XP Syphilis assay can be considered a sensitive and accurate assay for identification of treponemal antibodies in screening populations as well as patients presenting with suspicion of syphilitic infection.

  2. Blood Collection Tubes and Storage Temperature Should Be Evaluated when Using the Siemens ADVIA Centaur XP for Measuring 25-Hydroxyvitamin D.

    PubMed

    Yu, Songlin; Zhou, Weiyan; Cheng, Xinqi; Fang, Huiling; Zhang, Ruiping; Cheng, Qian; Han, Jianhua; Su, Wei; Xia, Liangyu; Qiu, Ling

    2016-01-01

    A significant bias was found when using the Siemens ADVIA Centaur XP system for measurement of 25-hydroxyvitamin D (25OHD) with VACUETTE® tubes with Serum Clot Activator and Gel. Here, we examined whether other commonly used tubes or temperatures affected 25OHD results obtained with the Siemens ADVIA Centaur XP system. Serum was collected into five types of vacuum blood collection tubes from three manufacturers, and 25OHD was analyzed using the Siemens ADVIA Centaur XP system and liquid chromatography tandem mass spectrometry (LC-MS/MS) immediately or after storage at 4°C or -80°C for 48 h. Significantly higher 25OHD values were found when using the Siemens ADVIA Centaur XP system with VACUETTE® tubes with serum clot activator and gel and VACUETTE® tubes with clot activator but no gel compared with VACUETTE® tubes with no additives. The 25OHD values in all of these tubes were not significantly different from those obtained by LC-MS/MS. Moreover, after storage at -80°C for 48 h, the values obtained in IMPROVEVACUTER® tubes with serum clot activator and gel significantly increased, with a mean bias of 74.6% compared with the values before storage, on analysis with the Siemens ADVIA Centaur XP system. VACUETTE® tubes containing additives significantly affect the accuracy of 25OHD results obtained using the Siemens ADVIA Centaur XP system. Additionally, the composition of serum collected in IMPROVEVACUTER® tubes was affected by freezing, resulting in different measurements when using the Siemens 25OHD assay platform.

  3. Influence of Vitamin D Binding Protein on Accuracy of 25-Hydroxyvitamin D Measurement Using the ADVIA Centaur Vitamin D Total Assay

    PubMed Central

    Freeman, James; Wilson, Kimberly; Spears, Ryan; Shalhoub, Victoria; Sibley, Paul

    2014-01-01

    Vitamin D status in different populations relies on accurate measurement of total serum 25-hydroxyvitamin D [25(OH)D] concentrations [i.e., 25(OH)D3 and 25(OH)D2]. This study evaluated agreement between the ADVIA Centaur Vitamin D Total assay for 25(OH)D testing (traceable to the NIST-Ghent reference method procedure) and a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for various populations with different levels of vitamin D binding protein (DBP). Total serum 25(OH)D concentrations were measured for 36 pregnant women, 40 hemodialysis patients, and 30 samples (DBP-spiked or not) from healthy subjects. ELISA measured DBP levels. The mean serum DBP concentrations were higher for pregnancy (415 μg/mL) and lower for hemodialysis subjects (198 μg/mL) than for healthy subjects and were highest for spiked serum (545 μg/mL). The average bias between the ADVIA Centaur assay and the LC-MS/MS method was −1.4% (healthy), −6.1% (pregnancy), and 4.4% (hemodialysis). The slightly greater bias for samples from some pregnancy and hemodialysis subjects with serum DBP levels outside of the normal healthy range fell within a clinically acceptable range—reflected by analysis of their low-range (≤136 μg/mL), medium-range (137–559 μg/mL), and high-range (≥560 μg/mL) DBP groups. Thus, the ADVIA Centaur Vitamin D Total assay demonstrates acceptable performance compared with an LC-MS/MS method for populations containing different amounts of DBP. PMID:25045351

  4. ANNALS EXPRESS: Impact of light exposure on TSH results using the Siemens Advia Centaur TSH-3Ultra assay.

    PubMed

    Armer, Jane M; Giles, Diane; Lancaster, Ian; Brownbill, Kathryn

    2017-01-01

    Background TSH is used as the first line test of thyroid function. Siemens Healthcare Diagnostics recommend that Siemens Centaur reagents must be protected from light in the assay information and on reagent packaging. We have compared the effect of light exposure on results using Siemens TSH-3Ultra and FSH reagents. The TSH reagent includes fluoroscein thiocyanate (FITC) whereas the FSH reagent does not. Methods Three levels of quality controls were analysed using SiemensTSH-3Ultra and FSH reagent packs that had been kept protected from light or exposed to light at 6 hour intervals for 48 hours and then at 96 hours. Results TSH results were significantly lower after exposure of TSH-3Ultra reagent packs to light. Results were >15% lower at all three levels of QC following 18 hours of light exposure and continued to decrease until 96 hours. There was no significant difference in FSH results whether reagents had been exposed to or protected from light. Conclusions TSH results but not FSH results are lowered after exposure of reagent packs to light. Laboratories must ensure that TSH-3Ultra reagents are not exposed to light and analyse quality control samples on every reagent pack to check that there has not been light exposure prior to delivery. The labelling on TSH-3Ultra reagent packs should reflect the significant effect of light exposure compared to the FSH reagent. We propose that the effect of light exposure on binding of FITC to the solid phase antibody is causing the falsely low results.

  5. Hydroxyzine and cetirizine interfere with the PENTINA carbamazepine assay but not with the ADVIA CENTEUR carbamazepine assay.

    PubMed

    Dasgupta, Amitava; Tso, Gertie; Johnson, Myrtle; Chow, Loretta

    2010-02-01

    Because of a published report indicating significant interference of hydroxyzine with the particle-enhanced turbidimetric inhibition immunoassay (PENTINA) carbamazepine assay, we investigated whether such interference can be avoided by using the ADVIA Centaur carbamazepine assay. Both the Dimension Vista analyzer and ADVIA Centaur analyzer are available from Siemens Diagnostics. Aliquots of a drug-free serum pool were supplemented with various concentrations of hydroxyzine or cetirizine (0.05 microg/mL to 20 microg/mL covering therapeutic and toxic levels in serum) followed by analysis using both assays. We observed significant apparent carbamazepine concentrations using the PENTINA assay but no apparent carbamazepine level using the ADVIA Centaur assay. Because crossreactivity should be studied in the presence of the primary analyte, we also prepared a serum carbamazepine pool from patients receiving carbamazepine and then supplemented aliquots of this pool with various amounts of hydroxyzine or cetirizine followed by reanalyzing carbamazepine concentration using both assays. We observed falsely elevated carbamazepine values using the PENTINA assay but no interference was observed using the ADVIA Centaur assay. However, the falsely elevated carbamazepine values using the PENTINA assay were clinically significant at hydroxyzine or cetirizine concentrations expected in patients with severe overdoses with these drugs. We conclude that the ADVIA Centaur carbamazepine assay is free from interference of both hydroxyzine and cetirizine.

  6. Preliminary Centaur Systems Analysis

    NASA Technical Reports Server (NTRS)

    Maronde, R. G.; Holmes, J. K.; Iwasaki, R. S.

    1981-01-01

    The Centaur is stored in the Orbiter payload bay on the Centaur Integrated Support System (CISS). The CISS not only cradles the Centaur prior to deployment but also provides any signal conditioning required to make the Centaur/Orbiter hardwire interfaces compatible. In addition, the CISS provides other Centaur functions such as controlling all the avionics safety features and providing all the helium supplies for tank pressurizations. Problems associated with a Centaur design concept using a transponder and two switchable antennas are defined. Solutions to these problems are presented.

  7. THE ACTIVE CENTAURS

    SciTech Connect

    Jewitt, David

    2009-05-15

    The Centaurs are recent escapees from the Kuiper Belt that are destined either to meet fiery oblivion in the hot inner regions of the solar system or to be ejected to the interstellar medium by gravitational scattering from the giant planets. Dynamically evolved Centaurs, when captured by Jupiter and close enough to the Sun for near-surface water ice to sublimate, are conventionally labeled as 'short-period' (specifically, Jupiter-family) comets. Remarkably, some Centaurs show comet-like activity even when far beyond the orbit of Jupiter, suggesting mass loss driven by a process other than the sublimation of water ice. We observed a sample of 23 Centaurs and found nine to be active, with mass-loss rates measured from several kg s{sup -1} to several tonnes s{sup -1}. Considered as a group, we find that the 'active Centaurs' in our sample have perihelia smaller than the inactive Centaurs (median 5.9 AU versus 8.7 AU), and smaller than the median perihelion distance computed for all known Centaurs (12.4 AU). This suggests that their activity is thermally driven. We consider several possibilities for the origin of the mass loss from the active Centaurs. Most are too cold for activity at the observed levels to originate via the sublimation of crystalline water ice. Solid carbon monoxide and carbon dioxide have the opposite problem: they are so volatile that they should drive activity in Centaurs at much larger distances than observed. We consider the possibility that activity in the Centaurs is triggered by the conversion of amorphous ice into the crystalline form accompanied by the release of trapped gases, including carbon monoxide. By imposing the condition that crystallization should occur when the crystallization time is shorter than the orbital period we find a qualitative match to the perihelion distribution of the active Centaurs and conclude that the data are consistent with the hypothesis that the Centaurs contain amorphous ice.

  8. Centaur Standard Shroud (CSS) cryogenic unlatch tests

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Cryogenic tanking and partial jettison (unlatch) tests were performed on a full scale Centaur vehicle and Centaur Standard Shroud (CSS) to develop and qualify the CSS insulation system, the CSS and Centaur ground-hold purge systems, and the Centaur hydrogen tank flight vent system. Operation of the shroud/Centaur pyrotechnic systems, seals, and the shroud jettison springs, hinges, and other separation systems was demonstrated by a partial jettison of the shroud into catch nets. The Centaur tanks were filled with liquid hydrogen and liquid nitrogen. Prelaunch operations were performed, and data taken to establish system performances. Results from the initial tests showed a higher than expected heat transfer rate to the Centaur hydrogen tank. In addition, the release mechanism for the forward seal between the Centaur and the CSS did not function properly, and the seal was torn during jettison of the shroud.

  9. Centaur size distribution with DECam

    NASA Astrophysics Data System (ADS)

    Fuentes, Cesar; Trilling, David E.; Schlichting, Hilke

    2014-11-01

    We present the results of the 2014 centaur search campaign on the Dark Energy Camera (DECam) in Tololo, Chile. This is the largest debiased Centaur survey to date, measuring for the first time the size distribution of small Centaurs (1-10km) and the first time the sizes of planetesimals from which the entire Solar System formed are directly detected.The theoretical model for the coagulation and collisional evolution of the outer solar system proposed in Schlichting et al. 2013 predicts a steep rise in the size distribution of TNOs smaller than 10km. These objects are below the detection limit of current TNO surveys but feasible for the Centaur population. By constraining the number of Centaurs and this feature in their size distribution we can confirm the collisional evolution of the Solar System and estimate the rate at which material is being transferred from the outer to the inner Solar System. If the shallow power law behavior from the TNO size distribution at ~40km can be extrapolated to 1km, the size of the Jupiter Family of Comets (JFC), there would not be enough small TNOs to supply the JFC population (Volk & Malhotra, 2008), debunking the link between TNOs and JFCs.We also obtain the colors of small Centaurs and TNOs, providing a signature of collisional evolution by measuring if there is in fact a relationship between color and size. If objects smaller than the break in the TNO size distribution are being ground down by collisions then their surfaces should be fresh, and then appear bluer in the optical than larger TNOs that are not experiencing collisions.

  10. 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.

  11. 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.

  12. The sizes, albedos, and comae of Centaurs

    NASA Astrophysics Data System (ADS)

    Trilling, David; Mueller, Michael; Noll, Keith; Stansberry, John

    2008-03-01

    The small bodies of the Solar System retain the best information about the era of planet formation and the subsequent evolution of our planetary system. As escaped KBOs that wander close(r) to Earth and to the Sun, we have the opportunity to study KBOs with a sensitivity and resolution that is not generally available in the main Kuiper Belt. Centaurs are both dynamically transitional --- as former Kuiper Belt Objects and potentially future comets --- and physically so, as some display cometary activity that is absent in the Kuiper Belt. We propose here to observe 27 Centaurs with Spitzer to address these fundamental questions about this interesting transitional population. We will determine their physical properties --- size and albedo --- as a probe of their fundamental nature. We will carry out a coma search. This program will more than double the number of Centaurs observed with Spitzer and create a sample of nearly 50 targets in which we can look for correlations among physical properties and derive a true size distribution for Centaurs that can be compared to the best-known KBO and Jupiter family comet size distributions. If any Centaurs in our sample are observed to be binaries in a companion HST program, we will derive their densities, and compare Centaur densities to KBO densities. We will look for common properties among active Centaurs. The results will reveal the physical properties of this interesting transitional population, and help constrain the suggested link between Kuiper Belt Objects and Jupiter family comets.

  13. 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.

  14. 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.

  15. 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.

  16. New Limits to CO Outgassing in Centaurs

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    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.

  17. 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.

  18. 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.

  19. The Centaur family. [for future use with Space Shuttle

    NASA Technical Reports Server (NTRS)

    Rector, W. F., III

    1982-01-01

    The Centaur upper stage has been used with Atlas and Titan boosters for a total of 66 launches, and is now being considered for future use with the Space Shuttle. Centaur's high-energy oxygen-hydrogen propellant combination provides the maximum performance capability for launching geosynchronous and earth-escape missions with both boosters. Shuttle/Centaur performance, combined with the demonstrated low-thrust operating capability of the Centaur engines, will allow gentle transfer of large communications spacecraft into geostationary orbit, thus significantly increasing the economies of communication satellites. This paper presents Centaur configurations, payload capabilities, and payload envelopes for future applications.

  20. 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.

  1. On the dynamical evolution and end states of binary centaurs

    NASA Astrophysics Data System (ADS)

    Brunini, A.

    2014-01-01

    In this paper, we perform a numerical integration of 666 fictitious binary Centaurs coming from the trans Neptunian space. Our population is restricted to tight binaries whose components have sizes between 30 and 100 km. We included the dynamical perturbations from the giant planets, Kozai Cycles induced by the Sun and tidal friction on the orbits of the binaries. We found that most binaries are disrupted during one of the close planetary encounters, making the mean lifetime of binary Centaurs much shorter than the one of single Centaurs. Nearly 10 per cent of the binaries reach a very tight circular orbit, arguing in favour of the existence of a non-negligible population of contact Centaurs. Another 10 per cent survive as a binary during their lifetime as Centaur. Our simulations favour the existence of a small population of very tight binary Centaurs.

  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. 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.

  4. Centaur D-1A guidance/software system

    NASA Technical Reports Server (NTRS)

    Gordan, A. L.

    1983-01-01

    The main body of this paper describes the evolution of the Centaur D-1A Guidance and Software System. Specifically, the performance of the explicit guidance equations, using a linear tangent steering law. Inherent flexibility exists in the equations in that they have multimission capability. They can accommodate both Earth-orbital and Earth-escape missions with either one or two Centaur burns. They can also guide for multi-burn orbital missions. The Centaur performance is indicated in terms of optimality (propellant usage), accuracy, flexibility and computer requirements. In the course of the Centaur Guidance development substantial changes and improvements have been made and more improvements are on the way for the Shuttle/Centaur Guidance. It is the intent of this paper to describe, provide insight into, and identify certain unique aspects of the individual Centaur flight profiles. Mission profile(s) are described narratively with some numerical data given in cases where it may be useful.

  5. Aerobrake for the Centaur Aerobrake Flight Experiment

    NASA Astrophysics Data System (ADS)

    Porter, John

    A retractable aerobrake using only current technology was predesigned. It would be flown on the Centaur rocket in 1992 as the principal part of the Centaur Aerobrake Flight Experiment (CAFE). A triple pass, constant dynamic pressure (TCP) trajectory was chosen to limit peak temperature to 2 260 F, and heating to 22 Btu/s-sq ft. The brake would fly at a 12-degree nominal angle of attack (AOA). Given a + or - 2-degree uncertainty, a worst case AOA of 10 degrees, producing a lift to drag (L/D) of 0.139 for trajectory correction, was used in the analysis. A new flexible Thermal Protection System was developed and crudely tested. An 8-inch diameter wind tunnel model and a 1/20th scale functional model were built. Flyable solutions were conceived for all technical challenges. It is concluded that with a 1988 start, there are no major technical roadblocks to a 1992 CAFE flight.

  6. 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.

  7. Calibration of qualitative HBsAg assay results for quantitative HBsAg monitoring.

    PubMed

    Gunning, Hans; Adachi, Dena; Tang, Julian W

    2014-10-01

    Evidence is accumulating that quantitative hepatitis B surface antigen monitoring may be useful in managing patients with chronic HBV infection on certain treatment regimens. Based on these results with the Abbott Architect qualitative and quantitative HBsAg assays, it seems feasible to convert qualitative to quantitative HBsAg values for this purpose.

  8. 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

  9. Development of STS/Centaur failure probabilities liftoff to Centaur separation

    NASA Technical Reports Server (NTRS)

    Hudson, J. M.

    1982-01-01

    The results of an analysis to determine STS/Centaur catastrophic vehicle response probabilities for the phases of vehicle flight from STS liftoff to Centaur separation from the Orbiter are presented. The analysis considers only category one component failure modes as contributors to the vehicle response mode probabilities. The relevant component failure modes are grouped into one of fourteen categories of potential vehicle behavior. By assigning failure rates to each component, for each of its failure modes, the STS/Centaur vehicle response probabilities in each phase of flight can be calculated. The results of this study will be used in a DOE analysis to ascertain the hazard from carrying a nuclear payload on the STS.

  10. Albedos of Centaurs, Jovian Trojans and Hildas

    NASA Astrophysics Data System (ADS)

    Romanishin, William

    2017-01-01

    I present optical V band albedo distributions for samples of outer solar system minor bodies including Centaurs, Jovian Trojans and Hildas. Diameters come almost entirely from the NEOWISE catalog (Mainzer etal 2016- Planetary Data System). Optical photometry (H values) for about 2/3 of the approximately 2700 objects studied are from PanStarrrs (Veres et al 2015 Icarus 261, 34). The PanStarrs optical photometry is supplemented by H values from JPL Horizons (corrected to be on the same photometric system as the PanStarrs data) for the objects in the NEOWISE catalog that are not in the PanStarrs catalog. I compare the albedo distributions of various pairs of subsamples using the nonparametric Wilcoxon rank sum test. Examples of potentially interesting comparisons include: (1) the median L5 Trojan cloud albedo is about 10% darker than that of the L4 cloud at a high level of statistical significance and (2) the median albedo of the gray Centaurs lies between that of the L4 and L5 Trojan groups.

  11. 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.

  12. Centaur boost pump turbine icing investigation

    NASA Technical Reports Server (NTRS)

    Rollbuhler, R. J.

    1976-01-01

    An investigation was conducted to determine if ice formation in the Centaur vehicle liquid oxygen boost pump turbine could prevent rotation of the pump and whether or not this phenomenon could have been the failure mechanism for the Titan/Centaur vehicle TC-1. The investigation consisted of a series of tests done in the LeRC Space Power Chamber Facility to evaluate evaporative cooling behavior patterns in a turbine as a function of the quantity of water trapped in the turbine and as a function of the vehicle ascent pressure profile. It was found that evaporative freezing of water in the turbine housing, due to rapid depressurization within the turbine during vehicle ascent, could result in the formation of ice that would block the turbine and prevent rotation of the boost pump. But for such icing conditions to exist it would be necessary to have significant quantities of water in the turbine and/or its components, and the turbine housing temperature would have to be colder than 40 F at vehicle liftoff.

  13. 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.

  14. Nucleus of the active Centaur C/2011 P2 (PANSTARRS)

    NASA Astrophysics Data System (ADS)

    Mazzotta Epifani, E.; Perna, D.; Dotto, E.; Palumbo, P.; Dall'Ora, M.; Micheli, M.; Ieva, S.; Perozzi, E.

    2017-01-01

    Aims: In this paper we present observations of the active Centaur C/2011 P2 (PANSTARRS), showing a compact comet-like coma at the heliocentric distance of rh = 9 au. The observations were obtained in the framework of a wider program on Centaurs aimed at searching for comet-like activity in several targets outside Jupiter's aphelion. Methods: We analysed visible images of the Centaur taken at the TNG telescope in the R filter to investigate the level of coma contributing to the target brightness and to derive information on its nucleus size. Results: Centaur C/2011 P2 (PANSTARRS) shows a faint but still detectable comet-like activity, which accounts for more than 50% to the observed brightness. The coma contribution has been subtracted in order to derive an estimate for the Centaur's diameter of D 16 km, assuming an albedo of A = 0.07 (average of albedo measured within the Centaur group). The results for Centaur C/2011 P2 (PANSTARRS) fit in the general picture of the group: Centaurs with smaller perihelion distance q and semi-major axis a are smaller than those remaining farther from the Sun during their orbital path, thus reinforcing the idea that active Centaurs are "comets in fieri". Based on observations collected at the Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the Centro Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  15. 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.

  16. 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.

  17. Two Color Populations of Kuiper Belt and Centaur Objects and the Smaller Orbital Inclinations of Red Centaur Objects

    NASA Astrophysics Data System (ADS)

    Tegler, S. C.; Romanishin, W.; Consolmagno, G. J.; J., S.

    2016-12-01

    We present new optical colors for 28 Kuiper Belt objects (KBOs) and 35 Centaur objects measured with the 1.8 m Vatican Advanced Technology Telescope and the 4.3 m Discovery Channel Telescope. 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 gray Centaurs. We find red Centaurs have a smaller orbital inclination angle distribution than gray 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 H V > 7.0 have bimodal colors at the 99.96% confidence level and KBOs with H V < 6.0 have bimodal colors at the 96% confidence level.

  18. Spectrophotometry of Kuiper Belt Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Lederer, S. M.; Vilas, F.

    2002-09-01

    We present an ongoing study of Kuiper Belt Objects (KBOs) and Centaurs. We acquired broadband (UBVRI) and medium band photometry with the 4m Mayall telescope at Kitt Peak and the 1.8m Perkins telescope at Lowell Observatory. We present broadband colors of these objects and discuss the results of our search for absorption bands in the visible spectral region. Vilas (Icarus, 111) demonstrated that the existence of the 0.7um absorption feature in asteroids with solar-like colors was strongly correlated with the presence of the 3.0um water of hydration feature. The broad 0.7um absorption band is attributed to a charge-transfer in Fe-bearing hydrated silicates (phyllosilicates), which are a product of aqueous alteration. For aqueous alteration to take place, one must have water ice present in an object, and an energy source to heat the water ice to a liquid water phase. Water ice has already been discovered in some Centaurs (Luu et al. ApJ, 531; Brown AJ, 119), and Durda and Stern (Icarus, 145) estimate that KBOs experience collisional processing regularly throughout their lifetimes. The estimated impact energies are high enough to induce aqueous alteration. We undertook this study to search for evidence of the 0.7um feature in KBOs and Centaurs. We employed medium band Windhorst filters, located at 0.527, 0.666, 0.705, 0.755 and 0.848 um in conjunction with the Mosaic CCD to search for this absorption band, which extends from 0.57-0.83um. Initial analysis suggests that an absorption feature exists near 0.7um in the greyer objects but not the redder objects, following the correlations observed in asteroids. These data are consistent with the absorption band detected near 0.7um by de Bergh et al. (ACM 2002, Berlin) in visible spectra of 2000 EB173 and 2000 GN171. However, further analysis is required to confirm whether the absorption we see is due to phyllosilicates or another source. We will present the results from this analysis. This research was supported through the

  19. Spectroscopy of Kuiper Belt Objects and Centaurs

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; Brown, Robert H.; Pendleton, Y. J.; Veeder, Glenn J.

    1998-01-01

    Recent near-infrared spectroscopy of Kuiper Belt objects and Centaurs indicates considerable spectral diversity among them. Some have entirely bland spectra with no discernible spectral features (e.g., Chiron), while 5145 Pholus has a very active spectrum with absorption bands of H2O, CH3OH, and probably the mineral olivine present. In addition, the strong red color of Pholus indicates the presence of organic solids. Among the KBOs, 1993 SC has an active spectrum with the probably presence of hydrocarbons and possibly the ices of H2O and N2. The diversity among these spectra and the implications that such diversity has for models of the formation of the formation of the planets will be discussed.

  20. 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.

  1. 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.

  2. Atlas Centaur 77 GOES-J Mated to Centaur at Cape Canaveral Air Station Complex 36B

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Geostationary Operational Environmental Satellite-J (GOES-J), a weather satellite to be launched aboard the Atlas I rocket, is hoisted into the Pad 36-B gantry and mated to the Atlas Centaur 77 (AC-77) rocket.

  3. A new HBsAg screening assay designed for sensitive detection of HBsAg subtypes and variants.

    PubMed

    van Roosmalen, M H; de Jong, J J; Haenen, W; Jacobs, T; Couwenberg, F; Ahlers-de Boer, G J C M; Hellings, J A

    2006-01-01

    The design of a new HBsAg screening assay, the Hepanostika HBsAg Ultra is based on the use of monoclonal antibodies raised against native wild-type HBsAg and reactive with HBsAg in which the common 'a'-determinant is modified by site-directed mutagenesis of four of the cysteine moieties. The design was checked using the same cysteine variants and samples from patients known to be infected with HBsAg variants. The results found were compared with other state-of-the-art commercial screening assays. The design of the Hepanostika HBsAg Ultra enabled detection of all variant HBsAg-positive samples in contrast to the other commercial assays. An additional 980 samples were tested to assess the specificity and sensitivity of the Hepanostika HBsAg Ultra. Screening of presumed negative serum and plasma samples resulted in a specificity of 100%. This makes the Hepanostika HBsAg Ultra the first screening assay with a design able to detect HBsAg variants with high sensitivity and specificity.

  4. 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.

  5. 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.

  6. 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.

  7. Vapor ingestion in Centaur liquid-hydrogen tank

    NASA Technical Reports Server (NTRS)

    Symons, E. P.

    1977-01-01

    Vapor ingestion phenomena were investigated using scale models of the Centaur liquid hydrogen tank to determine the height of the free surface of the liquid when vapor is intially ingested into the tank outlet. Data are compared with an analysin and, is general the agreement is very good. Predictions are presented for minimum liquid levels required in the Centaur liquid hydrogen tank in order to prevent vapor ingestion when restarting the engines in space and the quantities of liquid remaining in the tank at vapor ingestion during main engine firing.

  8. 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.

  9. 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.

  10. Analytical performance evaluation of ADVIA Chemistry Carbamazepine_2 assay: minimal cross-reactivity with carbamazepine 10, 11-epoxide and none with hydroxyzine or cetirizine.

    PubMed

    Dasgupta, Amitava; Reyes, Meredith A; Davis, Barbara G; Marlow, Anne M; Johnson, Myrtle

    2010-01-01

    Carbamazepine is an anticonvulsant requiring routine therapeutic drug monitoring. Recently, Siemens Healthcare Diagnostic Division released a new carbamazepine assay: ADVIA Chemistry Carbamazepine_2 (Carbamazepine_2) for application on ADVIA analyzers. We evaluated the analytical performance of this assay as well as its potential cross-reactivities with carbamazepine 10, 11-epoxide, hydroxyzine, and cetirizine. The within-run and between-run precisions of the Carbamzepine-2 assay were <6% and limit of detection was 0.5 microg/ml using ADVIA 1800 analyzer. The assay was linear up to a carbamazepine concentration of 20.0 microg/ml. The new method compared well with a widely used carbamazepine EMIT 2000 assay on the Hitachi 917 analyzer. Using 75 patients' specimens (where carbamazepine concentrations varied from 0.5 to 21.7 microg/ml) and carbamazepine EMIT 2000 as the reference method (x-axis), we observed the following regression equation: y=1.04 x+0.32 (r=0.99). The new carbazepine_2 method was not affected by a hemoglobin concentration of 1,000 mg/dl, conjugated or unconjugated bilirubin concentration of 60 mg/dl, and triglyceride concentration of 1,000 mg/dl. In addition, this assay showed no cross-reactivity with hydroxyzine or cetirizine and demonstrated minimal cross-reactivity with carbamazepine 10, 11-epoxide. We conclude that the ADVIA Chemistry carbamazepine_2 assay has adequate precision and accuracy for routine therapeutic drug monitoring of carbamazepine in clinical laboratories.

  11. Zero-G thermodynamic vent system for shuttle/Centaur

    NASA Technical Reports Server (NTRS)

    Niggemann, Richard E.

    1987-01-01

    Viewgraphs are presented showing drawings of Centaur configurations, the Thermodynamic Vent System (TVS), the mixer pump, and the hydrogen vent motor pump inverter. A cryogenic performance summary is given in chart form. The TVS liquid flow operation and vapor flow operation are diagrammed.

  12. 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.

  13. 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.

  14. 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.

  15. Enumeration of feline platelets in ethylenediamine tetra-acetic acid anticoagulated blood with the ADVIA 2120 system and two manual methods: Leucoplate and Thrombo-TIC.

    PubMed

    Tvedten, Harold W; Ljusner, Jessika; Lilliehöök, Inger E

    2013-07-01

    A manual method (Thrombo-TIC; Bioanalytic GmbH, Umkirch/Freiburg, Germany) was advertised to disaggregate platelet clumps and to make human platelets spherical to improve platelet enumeration. The current study's hypothesis was that this method would perform better than current methods for feline blood anticoagulated with ethylenediamine tetra-acetic acid (EDTA), which often contains platelet aggregates. Platelet concentrations (PLTs) were determined in 21 feline blood samples by 3 methods. Thrombo-TIC was compared to the manual method (Leucoplate; Sobioda, Montbonnot-Saint-Martin, France) currently used in the authors' laboratory along with an ADVIA 2120 (Siemens AG, Eschborn, Germany) optical platelet concentration. Feline blood samples often contained platelet aggregates. ADVIA flagged for platelet aggregates in 11 of the 21 feline blood samples, and examination of blood smear revealed platelet aggregates in 14 of the 21 samples. The hemocytometers displayed more platelet aggregates with the Thrombo-TIC method than with Leucoplate. The method giving the greatest PLT was considered most accurate. The Leucoplate median PLT (238 × 10(9)/1) was greater than Thrombo-TIC (202 × 10(9)/1) or ADVIA (157 × 10(9)/1). Intra-assay precision was determined for the 3 methods using the 21 feline blood samples. Median Thrombo-TIC and Leucoplate precision (7.4% and 7.3% coefficient of variation [CV], respectively) were similar and not much worse than ADVIA (5.9% CV). The Thrombo-TIC method did not appear to perform better than the current manual method (Leucoplate). Leucoplate appeared least affected by platelet aggregation in feline blood. The ADVIA automated PLT appeared to be most negatively affected by platelet aggregation. The Thrombo-TIC method did not appear to prevent platelet aggregation in feline EDTA blood samples and, thus, is not recommended for such use.

  16. Hepatocellular carcinoma HBsAg positive in pregnancy.

    PubMed

    Gonçalves, C S; Pereira, F E; de Vargas, P R; Ferreira, L S

    1984-01-01

    The authors present a case of hepatocellular carcinoma diagnosed in a pregnant woman (four months pregnancy). The clinical evolution was complicated because of a severe hypoglicemia and the patient died 12 weeks after admission. The fetus died before a tentative of surgical delivery. The patient was HBsAg positive and five out of eight sons (inclusively the fetus), were HBsAg positive. There was not indication that the pregnancy had enhanced the tumor evolution.

  17. Centaur D-1A nose fairing jettison test

    NASA Technical Reports Server (NTRS)

    Prati, W. M.

    1976-01-01

    An experimental investigation was conducted to verify the functional and structural capability of the Centaur D-1A nose fairing. A full-scale flight-type nose fairing was jettisoned at the Lewis Research Center Space Power Chamber at simulated altitude. Two complete jettisons of the nose fairing were performed, one without aft helper springs and one with aft helper springs. A ''static'' rotation test was also performed to verify capability of the helper springs and to allow clearance measurements between the nose fairing and spacecraft envelope mock-up at certain discrete nose fairing rotation angles. Nose fairing trajectories, structural deflections, clearances, and hinge forces during jettison are presented. Data from subsequent Centaur D-1A flights, relative to nose fairing jettisons, are compared with the experimental results.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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)

  5. 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.

  6. 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.

  7. All Shuttle Centaur engine and nozzle support plug vibration testing

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Loads applied to the RL10 engines while in flight in the orbiter payload bay are significantly different from the load environment experienced in Atlas and Titan/Centaur applications. To predict the engine loads, a NASTRAN analysis was conducted. As part of this effort a vibration test program was accomplished to provide input to the analysis, and to verify engine durability. This program was completed in two phases. The first phase provided data and characteristics which were used as input to the analysis. The second phase subjected the engine to limit loads, and included hot firings before and after the vibration test. The test hardware, performance, and results are described.

  8. Centaur Standard Shroud (CSS) full jettison test dynamic analysis

    NASA Technical Reports Server (NTRS)

    Kasper, H. J.; Donovan, R. M.

    1974-01-01

    During the space power facility jettison tests, the non-domed half of the Centaur standard shroud was allowed to completely separate from its hinge connection and was caught in a horizontal catch net. A rigid body dynamic analysis that was performed to predict the half shroud prior to and after net contact is presented. Analytical predictions of the longitudinal and circumferential bending moments imposed on the half shroud by the catch net and the net pressure on the half shroud corrugated skin are also presented.

  9. 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.

  10. Stellar Occultations by Trans-Neptunian Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Wolf, Juergen

    2015-10-01

    Our solar system beyond Neptune's orbit is populated with numerous small objects, referred to as Trans-Neptunian Objects (TNOs). About 1400 TNOs are known today ranging in size from the most prominent one, Pluto (2370 km diameter), down to a few tens of kilometers. Most diameters have been determined by radiometric methods in the IR/FIR (SPITZER, HERSCHEL) with uncertainties in the 20% range. Only for Pluto and about 12 other objects have the projected diameters been measured more accurately by stellar occultations. A group of objects lingering between the orbits of Jupiter and Neptune, the Centaurs, are believed to have originated from TNOs. Two of them, Chariklo and Chiron, have recently drawn attention, as stellar occultations have revealed rings around them. Our proposed occultation observations with SOFIA shall add to the sparse knowledge on TNOs and Centaurs by determining more projected diameters and albedos. They have the potential of detecting moons, rings and atmospheres. We will use SOFIA's demonstrated capability of measuring occultations (Pluto 2011 & 2015) with its Focal Plane Imager (FPI) to observe up to five events on flight legs of approximately 30 min each. As most of these events cannot be predicted accurately enough more than a few months or weeks ahead of time, we propose these as targets of opportunity.

  11. 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.

  12. 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.

  13. 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

  14. [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.

  15. 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.

  16. Identification of water ice on the Centaur 1997 CU26.

    PubMed

    Brown, R H; Cruikshank, D P; Pendleton, Y; Veeder, G J

    1998-05-29

    Spectra of the Centaur 1997 CU26 were obtained at the Keck Observatory on 27 October 1997 (universal time). The data show strong absorptions at 1.52 and 2.03 micrometers attributable to water ice on the surface of 1997 CU26. The reflectance spectrum of 1997 CU26 is matched by the spectrum of a mixture of low-temperature, particulate water ice and spectrally featureless but otherwise red-colored material. Water ice dominates the spectrum of 1997 CU26, whereas methane or methane-like hydrocarbons apparently dominate the spectrum of the Kuiper belt object 1993 SC, perhaps indicating different origins, thermal histories, or both for these two objects.

  17. 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.

  18. Identification of water ice on the Centaur 1997 CU26

    NASA Technical Reports Server (NTRS)

    Brown, R. H.; Cruikshank, D. P.; Pendleton, Y.; Veeder, G. J.

    1998-01-01

    Spectra of the Centaur 1997 CU26 were obtained at the Keck Observatory on 27 October 1997 (universal time). The data show strong absorptions at 1.52 and 2.03 micrometers attributable to water ice on the surface of 1997 CU26. The reflectance spectrum of 1997 CU26 is matched by the spectrum of a mixture of low-temperature, particulate water ice and spectrally featureless but otherwise red-colored material. Water ice dominates the spectrum of 1997 CU26, whereas methane or methane-like hydrocarbons apparently dominate the spectrum of the Kuiper belt object 1993 SC, perhaps indicating different origins, thermal histories, or both for these two objects.

  19. 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.

  20. 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.

  1. Methanol On The Extra-red Tnos And Centaurs

    NASA Astrophysics Data System (ADS)

    Antonieta Barucci, Maria; Dalle Ore, C.; Emery, J.; Merlin, F.; Cruikshank, D.; Perna, D.; de Bergh, C.

    2012-10-01

    We present an analysis of the reddest objects of the transneptunian and centaur populations, following the taxonomical class RR. A statistical analysis was performed by Barucci et al. (2011) including all existing data in the literature (76 objects) covering the spectral range from 0.4 to 2.3μm. The subgroup of RR class of objects (23) contains more than ¼ of the whole studied populations, including Centaurs, detached, classical, plutinos and scattered objects. In the whole studied sample, the CH3OH ice was detected spectroscopically only on three objects (Pholus, 2002VE95 and Sedna). These objects which are among the reddest ones, belong to different dynamical classes, and have different sizes. To further investigate the presence of CH3OH as part of the composition of the entire RR class we used the Spitzer data available for the RR class for a subgroup of nine objects. Both methanol and methane have a strong absorption at 3.6μm, the first of the Spitzer IRAC channels, and a much brighter albedo at the following channel at 4.5μm. Our technique makes use of a large database of models including H2O, CH3OH, CH4, and N2 ices combined with tholins, amorphous carbon, and silicates. We find that models containing some hydrocarbon ices are possible matches to the spectrum of almost all objects in our sample. Laboratory irradiation experiments show a strong reddening of the spectra of methanol. The presence of methanol on the extra-red objects could imply that these objects exhibit an almost primordial surface. Following the Brown et al (2011) hypothesis, the TNO surface composition and colors are established by formation-location in the early solar system. This would support the idea that objects formed further in the solar planetary disk could retain methanol. These results are in agreement with the hypothesis that substantial mixing has occurred after the TNOs formation.

  2. 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.

  3. HBsAg sT123N mutation induces stronger antibody responses to HBsAg and HBcAg and accelerates in vivo HBsAg clearance.

    PubMed

    Li, Songxia; Zhao, Kaitao; Liu, Shuhui; Wu, Chunchen; Yao, Yongxuan; Cao, Liang; Hu, Xue; Zhou, Yuan; Wang, Yun; Pei, Rongjuan; Lu, Mengji; Chen, Xinwen

    2015-12-02

    Immune escape mutants with mutations in the hepatitis B surface antigen (HBsAg) major hydrophilic region (MHR) often emerge in association with diagnostic failure or breakthrough of HBV infection in patients with anti-HBs antibodies. Some mutants harboring substitutions to Asn in HBsAg MHR may have an additional potential N-glycosylation site. We have previously showed that sT123N substitution could generate additional N-glycosylated forms of HBsAg. In the present study, 1.3-fold-overlength HBV genomes containing the sT123N substitution were digested from the pHBV1.3-sT123N construct and subcloned into the pAAV vector to generate pAAV1.3-sT123N for hydrodynamic injection (HI) in mice. Viral expression and replication were phenotypically characterized by transient transfection. The results demonstrated that sT123N substitution impaired virion secretion, resulting in intracellular retention of HBcAg. Using the HBV HI mouse model, we found that mice mounted significantly stronger antibody responses to HBsAg and HBcAg, which accelerated HBsAg clearance. Thus, additional N-glycosylation generated by amino acid substitutions in HBsAg MHR may significantly modulate specific host immune responses and influence HBV infection in vivo. Our results help further the understanding of the role of immune escape mutants with N-linked glycosylation in the biology of HBV infection.

  4. 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.

  5. 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

    2014-04-03

    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.

  6. A THERMAL EVOLUTION MODEL OF CENTAUR 10199 CHARIKLO

    SciTech Connect

    Guilbert-Lepoutre, A.

    2011-03-15

    Centaur 10199 Chariklo appears to have a varying spectral behavior. While three different spectral studies detect the presence of water ice at the surface, two more recent studies do not detect any absorption bands. In this article, we consider the possibility that Chariklo undergoes cometary activity that could be responsible for the observed spectral variations. We simulate its thermal evolution, finding that crystalline water ice should be present in the object core, and amorphous water ice should be found at the surface. Upon entering the inner solar system, Chariklo might experience some cometary activity due to ice crystallization if the obliquity is high, due to the adjustment of the internal structure to a new thermal equilibrium. No other activity is expected from this source, unless an external source like an impact provides the heat needed. In the case of such an event, we find that dust emitted in a coma is unlikely to be responsible for the observed spectral variations. In contrast, water ice grains in the coma would reproduce this pattern, meaning that the water ice detected after Chariklo's discovery was present in these grains and not on the object surface. Nonetheless, any activity would require an external additional heat source to be triggered, through an outburst, which might favor the spatial variations hypothesis.

  7. 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.

  8. 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.

  9. 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.

  10. Influence of the Centaurs and TNOs on the main belt and its families

    NASA Astrophysics Data System (ADS)

    Galiazzo, Mattia A.; Wiegert, Paul; Aljbaae, Safwan

    2016-12-01

    Centaurs are objects whose orbits are found between those of the giant planets. They are supposed to originate mainly from the Trans-Neptunian objects, and they are among the sources of Near-Earth Objects. Trans-Neptunian Objects (TNOs) cross Neptune's orbit and produce the Centaurs. We investigate their interactions with main belt asteroids to determine if chaotic scattering caused by close encounters and impacts by these bodies may have played a role in the dynamical evolution of the main belt. We find that Centaurs and TNOs that reach the inner Solar System can modify the orbits of main belt asteroids, though only if their mass is of the order of 10^{-9} m_{⊙} for single encounters or, one order less in case of multiple close encounters. Centaurs and TNOs are unlikely to have significantly dispersed young asteroid families in the main belt, but they could have perturbed some old asteroid families. Current main belt asteroids that originated as Centaurs or Trans-Neptunian Objects may lie in the outer belt with short lifetime ≤ 4 My, most likely between 2.8 and 3.2 au at larger eccentricities than typical of main belt asteroids.

  11. Investigation of the Centaur boost pump overspeed condition at main engine shutdown on the Titan Centaur TC-2 flight

    NASA Technical Reports Server (NTRS)

    Baud, K. W.

    1975-01-01

    An investigation was conducted to evaluate a potential boost pump overspeed condition which could exist on the Titan/Centaur launch vehicle after main engine shut-off. Preliminary analyses indicated that the acceleration imparted to the unloaded boost pump-turbine assembly, caused by purging residual hydrogen peroxide from the turbine supply lines, could result in a pump-turbine overspeed. Previous test experience indicated that turbine damage occurs at speeds in excess of 75,000 rpm. Detailed theoretical analyses, in conjunction with pump tests, were conducted to establish the maximum pump-turbine speed at main engine shut-off. The analyses predicted a maximum speed of 68,000 rpm. Testing showed the pump-turbine speed to be 66,700 rpm in the overspeed condition. Inasmuch as both the analysis and tests showed the overspeed to be sufficiently less than the speed at which damage could occur, it was concluded that no corrective action would be required for the launch vehicle.

  12. Seroclearance of Hbsag in Chronic Hepatitis B Virus Patients on Lamivudine Therapy: A 10 Year Experience

    PubMed Central

    Sali, Shahnaz; Merza, Muayad A.; Saadat, Sina; Mustafa, Nazik H.; Queiky, Farzam; Yadegarynia, Davood

    2015-01-01

    Introduction: The aim of this study was to determine hepatitis B surface antigen (HBsAg) seroclearance rate among patients treated with lamivudine at a specialized tertiary care referral hospital in Tehran, Iran. Methods: All patients on lamivudine (biovudin®) therapy at a dose of 100 mg/day, who showed seroclearnace between March 2001 and September 2011 were recruited. The main evaluation parameters were duration of HBsAg seroclearance and duration of HBsAg seroconversion. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were evaluated using standard methods. HBsAg seroclearance was defined as two consecutive negative serums HBsAg at least 6 months apart, whereas HBsAg seroconversion was defined as the disappearance of serum HBsAg and the presence of anti-HBs for >6 months. Results: A total of 203 chronic HBV patients treated with lamivudine at a dose of 100 mg/day were included in the study. HBsAg seroclearance and seroconversion were observed in 11 patients after the initiation of the lamivudine therapy. Overall, in lamivudine responder patients, the mean time to HBsAg seroclearance was 26.90±10.93 months (range: 12-48 months). Furthermore, the responders showed seroconversion after a mean time of 26.90±11.08 months from the initiation of lamivudine therapy. When comparing the characteristics of those who have responded to lamivudine and those who have not responded, baseline HBV-DNA levels was significantly lower in responder than non responder patients (p<0.001). Meantime, there was no difference in age, sex, baseline ALT, AST and liver biopsy score between lamivudine responder and lamivudine non-responder patients. Conclusion: Despite introduction of tenofovir and entecavir as first line treatment for chronic HBV infection, lamivudine remains to be a low cost, safe and effective drug for HBsAg seroclearnace. PMID:26153167

  13. 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.

  14. Self-regulating heater application to Shuttle/Centaur hydrazine fuel line thermal control

    NASA Technical Reports Server (NTRS)

    Unkrich, David B.

    1987-01-01

    The Shuttle/Centaur high energy upper stage vehicle thermal environments were more severe than previous Centaur vehicle thermal environments, creating need for a new hydrazine fuel line thermal control technique. Constant power heaters did not satisfy power dissipation requirements, because the power required to maintain fuel line thermal control during cold conditions exceeded the maximum power allowable during hot conditions. Therefore, a Raychem Thermolimit self-regulating heater was selected for this application, and was attached to the hydrazine fuel line with Kapton and aluminum foil tapes. Fuel line/heater thermal modeling and subsequent thermal vacuum chamber testing simulated heater thermal performance during all worst-case Shuttle/Centaur thermal environmental conditions. Fuel line temperatures were maintained between the 4C to 71C limits during all analytical and test cases. Finally, the thermal model predictions were correlated with the test data, thereby ensuring that the model would provide satisfactory predictions for future missions and/or vehicles.

  15. Hydrocarbon ices in extra-red TNOs and Centaurs

    NASA Astrophysics Data System (ADS)

    Dalle Ore, C. M.; Barucci, M.; Emery, J. P.; Cruikshank, D. P.; Merlin, F.; Perna, D.

    2012-12-01

    We present an analysis of the reddest trans-neptunian objects (TNOs) and Centaurs - those belonging to the RR taxon. The RR class contains more than ¼ of the population of TNOs for which photometric colors are available, including a variety of dynamically different objects. The available data cover the spectral range from 0.3 to 2.2 μm. Previous work investigated possible relations between spectral characteristics and other physical and dynamical parameters. The distribution of ices on TNOs has been analyzed as a function of the object absolute magnitude, taxonomy and dynamical class. In a sample of 76 objects for which visible and near-IR spectroscopic measurements are available, CH3OH ice was detected only on three objects belonging to the RR taxonomic class (5145 Pholus, 55638 2002 VE95 and 90377 Sedna). These three objects are among the reddest, they belong to different dynamical classes, and they have different dimensions. However, all three have similar compositions with Sedna showing a more significant heterogeneity in the kind of hydrocarbon ices found on its surface than the others. To further investigate the presence of hydrocarbon ices, and in particular CH3OH, as part of the composition of the RR taxon we used Spitzer IRAC data available for a subgroup of nine objects. Both methanol and methane have a strong absorption at 3.6 μm, the first of the Spitzer IRAC channels, and a much higher albedo at the following channel at 4.5 μm. This albedo pattern is characteristic of some hydrocarbon ices and is very different from H2O ice that shows instead very low albedos at both channels. Our technique makes use of a large database of models including H2O, CH3OH, CH4, and N 2 ices combined with tholins, amorphous carbon, hydrogenated amorphous carbon, serpentine and olivine in different combinations of relative abundances and grain sizes. We automatically extract the models that match the observations at all color wavelengths therefore obtaining for each

  16. The Ring System Discovered Around the Centaur Object (10199) Chariklo

    NASA Astrophysics Data System (ADS)

    Braga-Ribas, F.; Sicardy, B.; Ortiz, J. L.; Vieira Martins, R.; Colas, F.; Duffard, R.; Camargo, J. I. B.; Desmars, J.; Gulbis, A.; Assafin, M.; Maquet, L.; Beisker, W.; Benedetti-Rossi, G.; Vachier, F.; Dumas, C.; Ivanov, V. D.; Renner, S.; Bath, K. L.; Klotz, A.; Pollock, J. T.

    2014-12-01

    Observations of a stellar occultation on 03 June 2013 led to the discovery of the first ring system around a small Solar System object, the Centaur (10199) Chariklo (Braga-Ribas et al. 2014, Nature, 508, 72). The object has a radius of about 125 km and moves on an unstable orbit between Saturn and Uranus, with lifetime of about 10 Myr. The fifth ring system ever discovered (after those around the four giant planets) is made of two dense and narrow rings with respective widths of 7 and 3 kilometers, normal optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometers, respectively (see figure). They are separated by an empty gap of about 9 km (see Figure 1). Their current configuration may be explained by the presence of putative kilometric-sized satellites. By means of the shepherd mechanism, satellites can confine and open the gap between the rings, otherwise they would spread out in few thousand years. From 1997 to 2008, the Chariklo system exhibited an unexplained behavior. It dimmed by 0.6 in absolute magnitude and the water-ice band in its spectrum, formerly observed, could not be detected in 2008. All this is simply explained by the rings' pole orientation, which implies that they were seen edge-on in 2007-2008. We can also calculate their reflectivity I/F ~ 0.1. Spectroscopic and photometric observations of the system allowed us to calculate the amount of water ice and silicate elements in the rings as well as on the main body. No water ice is detectable on the surface of Chariklo. New stellar occultations by the Chariklo system were observed in 2014, and they show the fine structure of the rings as well confirm the preferred pole position from the 2013 event. These findings will be presented and possible formation scenarios will be discussed.

  17. 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

  18. 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

  19. Water Ice in 2060 Chiron and Its Implications for Centaurs and Kuiper Belt Objects.

    PubMed

    Luu; Jewitt; Trujillo

    2000-03-10

    We report the detection of water ice in the Centaur 2060 Chiron, based on near-infrared spectra (1.0-2.5 µm) taken with the 3.8 m United Kingdom Infrared Telescope and the 10 m Keck Telescope. The appearance of this ice is correlated with the recent decline in Chiron's cometary activity: the decrease in the coma cross section allows previously hidden solid-state surface features to be seen. We predict that water ice is ubiquitous among Centaurs and Kuiper Belt objects, but its surface coverage varies from object to object and thus determines its detectability and the occurrence of cometary activity.

  20. 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.

  1. Time to seroconversion of HBsAg to anti-HBs in individuals who lost HBsAg during follow-up.

    PubMed

    Roushan, M R H; Mohammadpour, M; Baiany, M; Soleimani, S; Bijani, A

    2016-09-01

    To determine the time to appearance of antibody against hepatitis B surface antigen (anti-HBs) after clearance of hepatitis B surface antigen (HBsAg) in chronically infected individuals, we followed up 3963 cases with positive antibody against hepatitis B e antigen (anti-HBe) from 1991 to 2014. Of these, 101 (67 males, 34 females) lost HBsAg. These serocleared cases were checked every 6-month interval regarding HBsAg, anti-HBs, liver function tests, and liver sonography. Hepatitis B virus DNA was assessed at the time of seroclearance or the appearance of anti-HBs. The mean age of these patients at entry to this study was 34·4 ± 13 years. The mean follow-up duration until seroclearance of HBsAg was 6·6 ± 4·3 years. After the mean follow-up of 43·7 ± 45 months, anti-HBs appeared in 64 (63·4%) cases. The cumulative probabilities of anti-HBs appearance for 2, 5 and 10 years were 24·3%, 58% and 78·2%, respectively. The appearance of anti-HBs was associated with age ⩾35 years and seroclearance of HBsAg (hazard ratio 1·96, 95% confidence interval 1·32-3·38, P = 0·016) but not with sex. The results show that anti-HBs may develop in 78·2% of cases within 10 years of HBsAg clearance. Age ⩾35 years at HBsAg loss was associated with earlier development of anti-HBs.

  2. 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.

  3. Forward bearing reactor mechanism for Titan 3-E/Centaur D-1T space launch vehicle

    NASA Technical Reports Server (NTRS)

    Jones, R. A.

    1975-01-01

    System between the Titan/Centaur launch vehicle and its aerodynamic shroud is described. The system provides a precise spring constant and is capable of being inactivated during flight. Design requirements, design details, and the test program are discussed. The conventional English system of units was used during this development program for all principal measurements and calculations.

  4. 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

  5. Ion Irradiation of Asphaltite: Optical Effects and Implications for Trans-Neptunian Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Moroz, L. V.; Baratta, G.; Distefano, E.; Strazzulla, G.; Starukhina, L. V.; Dotto, E.; Barucci, M. A.

    2003-06-01

    Trans-Neptunian Objects (TNOs) and Centaurs show remarkable colour variations in the visual and near-infrared spectral regions. Surface alteration processes such as space weathering (e.g., bombardment with ions) and impact resurfacing may play an important role in the colour diversity of such bodies. Ion irradiation of hydrocarbon ices and their mixtures with water ice transforms neutral (grey) surface colours of ices to red and further to grey. Along with the ices, TNOs and Centaurs probably contain complex carbonaceous compounds, in particular, complex hydrocarbons. Unlike ices, such refractory organic materials have originally low visual albedos and red colours in the visible and near-infrared ranges. Here we present the first results of ion irradiation experiments on asphaltite. Asphaltite is a natural complex hydrocarbon material. The reflectance spectra of asphaltite in the 0.4-0.8 μm range have been recorded before irradiation and after each irradiation step. We demonstrate that irradiation of this red dark material with 30 keV H+ and 15 keV N+ ions gradually transforms its colour from red to grey as a result of carbonization. A moderate increase in the visual albedo has been observed. These results may imply that the surfaces of primitive red objects optically dominated by complex refractory organics may show a similar space weathering trend. Our laboratory results were compared with published colours of TNOs and Centaurs. A broad variety of spectral colours observed for TNOs and Centaurs may be reproduced by various spectra of irradiated organics corresponding to different ion fluences. However, such objects probably also contain ices and silicate components which show different space weathering trends. This fact, together with a lack of information about albedos, may explain difficulties to reveal correlations between surface colours within TNO and Centaur populations and their other properties, such as absolute magnitudes and orbital parameters.

  6. Dense and narrow rings around the Centaur object (10199) Chariklo

    NASA Astrophysics Data System (ADS)

    Sicardy, Bruno; Braga-Ribas, Felipe; Ortiz, Jose Luis; Vieira-Martins, Roberto; Colas, Francois; Duffard, Rene; Camargo, Julio I.; Desmars, Josselin; Gulbis, Amanda; Assafin, Marcelo; Maquet, Lucie; Beisker, Wolfgang; Benedetti-Rossi, Gustavo; Vachier, Frederic; Dumas, Christophe; Ivanov, Valentin D.; Renner, Stefan; Bath, Karl-Ludwig; Klotz, Alain; Pollock, Joseph T.; Lecacheux, Jean; Dauvergne, Jean-Luc; Peyrot, Andre; Teng, Jean-Paul

    2014-11-01

    A stellar occultation observed on June 3, 2013 (Braga-Ribas et al., Nature 508, 72, 2014) revealed the unexpected presence of two dense rings around (10199) Chariklo, the largest Centaur object known to date with a radius of 119±5 km (Fornasier et al. A&A 2014, in press). The two rings (called respectively C1R and C2R hereby) have orbital radii a_C1R= 390.6±3.3 km and a_C2R= 404.8±3.3 km (1-sigma limits), and typical average optical depths of tau_C1R= 0.4 and tau_C2R= 0.06. They are separated by a gap of about 9 km with optical depth less than 0.004.The presence of those two rings was confirmed during four stellar occultations observed in 2014, on February 16 (Chile), March 16 (Thailand), April 29 (Southern Africa) and June 28 (Southern Africa).The occultation events imply a J2000 pole position of α= 151.25±0.50 and δ= 41.48±0.22 deg. The rings' changing geometry explains the long term variations of Chariklo's absolute magnitude and the spectral changes observed between 1997 and 2013. They imply a reflectance I/F of about 0.07 for C1R, and show that it contains about 20% of water ice, the latter remaining undetected on Chariklo's surface (Duffard et aL A&A 2014, in press).The April 29, 2014 occultation reveals a W-shaped structure for C1R, with the densest parts reaching an apparent optical depth of about 2. The width of C1R exhibits variations that are compatible with a m=1 mode, its value varying between ~5.5 and ~7.1 km over the full 360 degrees longitude range. The width of C2R is less constrained and lies between 2 and 4 km.This is the first ring system ever observed that does not pertain to a giant planet. The existence of such a system raises several questions as to the origin and evolution of rings around such a small object. This discovery also suggests that rings may be a more frequent feature than previously thought, in particular around small bodies.Possible models for the ring formation will be proposed. They can be classified into collisional

  7. 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.

  8. Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis of WISE/NEOWISE Observations

    NASA Astrophysics Data System (ADS)

    Bauer, James M.; Grav, Tommy; Blauvelt, Erin; Mainzer, A. K.; Masiero, Joseph R.; Stevenson, Rachel; Kramer, Emily; Fernández, Yan R.; Lisse, C. M.; Cutri, Roc M.; Weissman, Paul R.; Dailey, John W.; Masci, Frank J.; Walker, Russel; Waszczak, Adam; Nugent, Carrie R.; Meech, Karen J.; Lucas, Andrew; Pearman, George; Wilkins, Ashlee; Watkins, Jessica; Kulkarni, Shrinivas; Wright, Edward L.; WISE Team; PTF Team

    2013-08-01

    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 ~-1.7 ± 0.3. The data also reveal a relation between albedo and color at the 3σ level. No significant relation between diameter and albedos is found.

  9. 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.

  10. Atlas/Centaur-29 Intelsat IV (F5) flash flight report

    NASA Technical Reports Server (NTRS)

    1972-01-01

    ATLAS/CENTAUR-29 was launched from ETR Complex 36B, June 13, 1972, at a flight azimuth of 101 degrees. The ETR test number was 1240. The launch vehicle consisted of an ATLAS SLV-3C first stage and a CENTAUR second stage. The spacecraft was INTELSAT 4 (F-5). The launch occurred at the opening of the window. Indications are that the spacecraft was injected into the required transfer orbit and has achieved it's final orbit. All orbital parameters were extremely close to nominal. A nominal apogee motor burn took place at 2101 EDT on June 14, 1972 at 124 degrees East longitude and the final duty station of the spacecraft will be at 62 degrees East longitude. A two week communications checkout was started on or about June 15, 1972.

  11. 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.

  12. 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.

  13. Modal test/analysis correlation for Centaur G Prime launch vehicle

    NASA Technical Reports Server (NTRS)

    Chen, J.; Rose, T.; Trubert, M.; Wada, B.; Shaker, F.

    1986-01-01

    A modal test was performed on the Centaur G Prime launch vehicle for the purpose of verifying the loads analysis model. This paper describes the procedure by which modal parameters obtained in this test were correlated with the corresponding analytical predictions. Based on this correlation the stiffness model of the shuttle trunnion system has been modified. The evolution of the model updating and the final results are described.

  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. Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis of WISE/NEOWISE Observations

    NASA Astrophysics Data System (ADS)

    Bauer, James M.; Grav, T.; Mainzer, A. K.; Masiero, J. R.; Blauvelt, E.; Stevenson, R.; Kramer, E.; Fernandez, Y. R.; Lisse, C. M.; Cutri, R. M.; Weissman, P. R.; Dailey, J. W.; Masci, F. J.; Walker, R.; Waszczak, A.; Nugent, C. R.; Meech, K. J.; Lucas, A.; Pearman, G.; Wilkins, A.; Watkins, J.; Kulkarni, S.; Wright, E. L.; WISE Team; PTF Team

    2013-10-01

    The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and Scattered Disk Objects in the thermal infrared, including discoveries of 15 previously unknown objects. At this writing, this is the largest published collection of thermal infrared measurements of Centaur and SDOs. We present analyses of these observations to estimate sizes and mean optical albedos derived from photometry of the WISE images taken simultaneously at wavelengths of 3.4, 4.6, 12, and 22 microns. We find mean visual-wavelength geometric albedos of 0.08, +/- 0.04 standard deviations, 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, and there appears to be no trend of beaming with heliocentric distance. Raw cumulative size distributions for objects with diameters > 20 km yield size-frequency distribution power law indices ~ -1.7 +/- 0.3. The data also reveal a relation between albedo and color at the 3-sigma level, with those objects with visual-wavelength B-R colors < 1.4 magnitudes having significantly lower albedos than those with B-R colors exceeding 1.4 magnitudes. No significant relation between diameter and albedos is found. We will also discuss the implications of these survey results concerning the related comet and TNO populations.

  16. Effect of Gimbal friction modeling technique on control stability and performance for Centaur upper-stage

    NASA Technical Reports Server (NTRS)

    Graham, Ronald E.

    1987-01-01

    The powered-phase autopilot for the Centaur upper stage rocket uses an autopilot forward loop gain scheduler that decreases the proportional gain as propellant mass is depleted. Nonlinear time response simulation studies revealed that Centaur vehicles with low-gain autopilots would have large attitude error limit cycles. These limit cycles were due to the assumed presence of Coulomb friction in the engine gimbals. This situation could be corrected through the use of an harmonic dither, programmed into the on-board digital computer and added to the engine command signal. This would introduce impending motion to the engines, allowing control of the engines even under small commands. Control authority was found to be restored when dither was used. A concern arose that the Centaur could be unacceptably excited at resonances near the dither frequency, if the dither amplitude was to be chosen on the basis of friction level present, a test was conducted to measure this level. Dither characteristics were to be based on the test results. The test results showed that the gimbal friction characteristic was actually hysteretic rather than the assumed Coulomb friction. The simulation results showed that, using this new model of gimbal friction, dither would no longer be necessary.

  17. Effect of gimbal friction modelling technique on control stability and performance for Centaur upper stage

    NASA Technical Reports Server (NTRS)

    Graham, Ronald E.

    1987-01-01

    The powered-phase autopilot for the Centaur upper stage rocket uses an autopilot forward loop gain scheduler that decreases the proportional gain as propellant mass is depleted. Nonlinear time response simulation studies revealed that Centaur vehicles with low-gain autopilots would have large attitude error limit cycles. These limit cycles were due to the assumed presence of Coulomb friction in the engine gimbals. This situation could be corrected through the use of an harmonic dither, programmed into the on-board digital computer and added to the engine command signal. This would introduce impending motion to the engines, allowing control of the engines even under small commands. Control authority was found to be restored when dither was used. A concern arose that the Centaur could be unacceptably excited at resonances near the dither frequency, if the dither amplitude was to be chosen on the basis of friction level present, a test was conducted to measure this level. Dither characteristics were to be based on the test results. The test results showed that the gimbal friction characteristic was actually hysteretic rather than the assumed Coulomb friction. The simulation results showed that, using this new model of gimbal friction, dither would no longer be necessary.

  18. 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.

  19. 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.

  20. Different Mechanisms May Exist for HBsAg Synthesis and Secretion During Various Phases of Chronic Hepatitis B Virus Infection

    PubMed Central

    Li, Yunsong; Cai, Qun; Xie, Qinxiu; Zhang, Yafei; Meng, Xiangling; Zhang, Zhenhua

    2017-01-01

    Background The aim of this study was to characterize the expression and secretion of hepatitis B surface-antigen (HBsAg) in the hepatocytes of hepatitis B virus (HBV)-infected patients at different phases of infection; as such, the association of intrahepatic HBsAg expression with virological markers and the histological characteristics were analyzed. Material/Methods 302 chronic HBV infection patients who had not received antiviral therapy were stratified by HBeAg status. The proportion of HBsAg-positive cells was used as an indicator for HBsAg expression level. Results In HBeAg-positive patients, there was a significant correlation between serum HBsAg and serum HBV DNA levels (r=0.569, p<0.001). Intrahepatic HBsAg expression and serum HBsAg level in HBeAg-positive patients were higher than those in HBeAg-negative patients (p=0.002 and p<0.001, respectively). A significant correlation between serum HBsAg level and intrahepatic HBsAg expression was found in HBeAg-negative patients (r=0.377, p<0.001), but not in HBeAg-positive patients (r=0.051, p=0.557). Very interestingly, the correlation between serum HBsAg level and HBsAg expression in hepatocytes gradually increased along with disease progression through the immune-tolerant, immune-clearance, inactive, and recovery phases of HBV infection (r=−0.184, 0.068, 0.492, and 0.575; and p=0,238, 0,722, 0.012, and 0.002, respectively). Conclusions Different mechanisms may be involved in HBsAg synthesis and secretion in different phases of chronic HBV infection. PMID:28321112

  1. [Partial purification of HBsAg by the progressive elimination of serum proteins].

    PubMed

    Babeş, V T; Anton, G

    1988-01-01

    Partial elimination of proteins from HBsAg-positive sera was realised by raising the temperature and simultaneously lowering the pH. Products with a convenient level of purity (2.2 mg of proteins per ml) were obtained as well as a good recovery rate of the HBsAgs (8-24%).

  2. 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.

  3. 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

  4. 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.

  5. Titian/Centaur D-1TTC-4 Viking A flight data report

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Titan/Centaur TC-4 was launched from the Eastern Test Range, Complex 41, at 05:22 PM EDT on Wednesday, August 20, 1975. This was the second operational flight of the newest NASA unmanned launch vehicle. The spacecraft was the Viking A, the first 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. This report presents a review of the launch vehicle system flight data.

  6. 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.

  7. Analytic performance evaluation of a new turbidimetric immunoassay for carbamazepine on the ADVIA 1650 analyzer: effect of carbamazepine 10,11-epoxide.

    PubMed

    Dasgupta, Amitava; Datta, Pradip

    2005-02-01

    Carbamazepine, an anticonvulsant, requires therapeutic drug monitoring. Recently Bayer HealthCare, Diagnostics Division released a turbidimetric immunoassay of carbamazepine on the ADVIA 1650 analyzer. We evaluated the analytic performance of this assay by comparing values obtained with this new assay in sera of 54 patients receiving carbamazepine with the values obtained by using a widely used fluorescence polarization immunoassay (FPIA) and a chemiluminescent immunoassay (CLIA). The new turbidimetric immunoassay for carbamazepine showed excellent precision. The low control showed a total CV of 4.9% (mean 2.86, SD 0.14 microg/mL), the medium control demonstrated a total CV of 3.5% (mean 7.79, SD 0.27 microg/mL), and the high control showed a total CV of 4.8% (mean 16.15, SD 0.78 microg/mL). The assay was linear up to a carbamazepine concentration of 20 microg/mL. The assay showed excellent dilution recovery and recovery of samples supplemented with carbamazepine (mean recovery 102.2%). We observed an excellent correlation between the values obtained by the FPIA (x-axis) assay and the new turbidimetric (y-axis) assay (y = 0.96 x - 0.46, r = 0.99, n = 54). We also observed excellent correlation between the values obtained by the CLIA (x-axis) and the turbidimetric (y-axis) assay (y = 1.10 x -0.32, r = 0.99, n = 54). However, the slope of 1.10 was higher than the slope of 0.96 observed with the regression equation obtained by using values obtained by the FPIA and the turbidimetric assay. The positive bias obtained with the new turbidimetric assay compared with the CLIA assay resulted from lower cross reactivity of carbamazepine 10,11-epoxide, the active metabolite of carbamazepine, with CLIA. On the other hand, the cross reactivity of the metabolite is similar between the new turbidimetric assay and the FPIA assay. We conclude that the new turbidimetric assay can be used for routine monitoring of carbamazepine in clinical laboratories.

  8. Sequence analysis of the HBV S protein in Chinese patients with coexisting HBsAg and anti-HBs antibodies.

    PubMed

    Ding, Feng; Yu, Hong-Gang; Li, Yan-Xia; Cui, Ning; Dai, Jin-Fen; Yu, Jie-Ping

    2015-12-01

    The coexistence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in patients with hepatitis B virus (HBV) infection has been discovered and explained for several decades, but debate still exists. This study was to explore the relationship between this special serological pattern and mutations in S gene region. Fifteen patients with coexisting HBsAg and anti-HBs were selected as the experimental group, and 27 patients with HBsAg positive only were selected as the control group. The S gene region was amplified and sequenced. No significant differences were observed between the two groups with regard to age, gender, alanine aminotransferase level, HBsAg titer, genotype, and HBV DNA level. The patients from the two groups were infected with HBV of the genotype B and C. Compared with the control group, the experimental group showed a higher variability in amino acid within the N-terminal region and the MHR, especially the "a" determinant. The most frequent change in patients from the experimental group was located at positions s126. The coexistence of HBsAg and anti-HBs might be associated with the increased amino acid mutations in the "a" determinant. Further studies should be performed to determine the clinical implication of this serological pattern, including the binding of anti-HBs to HBsAg, escape from immune system, and efficacy of antiviral therapy.

  9. 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.

  10. Investigation of a Novel Hepatitis B Virus Surface Antigen (HBsAg) Escape Mutant Affecting Immunogenicity

    PubMed Central

    Hossain, Md. Golzar; Ueda, Keiji

    2017-01-01

    Mutation in the hepatitis B virus surface antigen (HBsAg) may affect the efficiency of diagnostic immunoassays or success of vaccinations using HBsAg. Thus, antigenicity and immunogenicity analyses of the mutated HBsAg are necessary to develop novel diagnostic tools and efficient vaccinations. Here, the in vitro antigenicity of three wild-type HBsAg open reading frames (ORFs) (adr4, W1S [subtype adr] and W3S [subtype adr]) isolated from clinically infected patients and nineteen synthesized single/double/multiple amino acid-substituted mutants were tested with commercial ELISA kits. Immunofluorescence staining of transfected cells and Western blot analysis confirmed that these ORFs were expressed at comparable levels in HEK-293 cells. W1S and adr4 were clearly detected, whereas W3S could not be detected. Using the same commercial immunoassay kit, we found that the single mutants, K120P and D123T, were marginally reactive, whereas W3S-aW1S and the double mutant, K120P/D123T, exhibited antigenicity roughly equivalent to the wild-type wako1S. On the other hand, the single mutants of W1S, P120K and T123D, significantly impaired the reactivity, while W1S-aW3S and the double mutant of W1S, P120K/T123D, resulted in a complete loss of antigenicity. In addition, ELISA revealed reduced HBs antigenicity of two mutants, W1S N146G and W1S Q129R/G145R. These commercial ELISA-based antigenic reactivities of HBsAg were also strongly correlated with the predicted Ai alterations of affected amino acids due to the specific mutation. In conclusion, this study showed for the first time that lysine (K120) and aspartate (D123) simultaneously affected HBsAg antigenicity, leading to diagnostic failure. These findings will improve diagnostic assays and vaccine development. PMID:28045894

  11. 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

  12. 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.

  13. 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.

  14. "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

  15. 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

  16. 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

  17. 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.

  18. 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).

  19. TLR8 agonists stimulate newly recruited monocyte-derived cells into potent APCs that enhance HBsAg immunogenicity

    PubMed Central

    Du, Jun; Wu, Zhiyuan; Ren, Shurong; Wei, Yong; Gao, Meihua; Randolph, Gwendalyn J.; Qu, Chunfeng

    2011-01-01

    We previously reported that synthetic or natural Toll-like receptor (TLR) 7/8 agonists present within dead cells enhanced cell-associated antigen presentation both in vitro and in vivo. Here, we investigated the immunopotency of different chemically synthesized TLR7/8 agonists, Resiquimod, Gardiquimod, CL075, and CL097, on HBsAg immunogenicity. These agonists stimulated inflammatory monocyte-derived cells to become potent antigen-presenting dendritic cells (DCs), which augmented HBsAg specific T cell proliferation after they were conditioned with HBsAg. The TLR8 agonist CL075 and the TLR7/8 dual agonist CL097 showed more potent effects than the TLR7 agonist. Compared with alum adjuvant, when HBsAg mixed with CL075 was injected intramuscularly into mice, more monocyte-derived DCs carried antigens into draining lymph nodes and spleens. Specific Abs, particularly IgG2a, were significantly increased, and more IL-5 and IFN-γ were produced by splenocytes and intrahepatic immunocytes in mice that received HBsAg mixed with CL075 and CL097. These results suggest that TLR8 agonists are good candidates to enhance recombinant HBsAg immunogenicity to induce specific humoral and cellular immune responses. PMID:20637759

  20. Titan/Centaur D-1TTC-5 Helios B flight data report

    NASA Technical Reports Server (NTRS)

    Adams, K. A.

    1976-01-01

    The fourth operational flight of the newest NASA unmanned launch vehicle is reported. The spacecraft was the Helios B, the second of two solar probes designed and built by the Federal Republic of Germany. The primary mission objective, to place the Helios spacecraft on a heliocentric orbit in the ecliptic plane with a perihelion distance of 0.29 AU, was successfully accomplished. After successful injection of the Helios spacecraft, a series of experiments were performed with the Centaur stage to demonstrate its operational capabilities. All objectives of the extended mission phase were successfully met. This report presents the analysis of the launch vehicle flight data for the primary mission phase of the TC-5 flight.

  1. 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.

  2. Status of HBsAg seroprevalence in 15 million rural couples in China: a cross-sectional study

    PubMed Central

    Zhang, Long; Wang, Yuan-Yuan; Huang, Yan-Jie; Wang, Qiao-Mei; Nelson, Kenrad E.; Wang, An-Qi; Shen, Hai-Ping; Liu, Xiao-Li; Zhang, Yi-Ping; Yan, Dong-Hai; Peng, Zuo-Qi; Zhang, Hong-Guang; Zhang, Ya; Zhao, Jun; Wang, Yan; Yang, Ying; He, Yuan; Xu, Ji-Hong; Liu, Du-Jia; Guo, Tong-Jun; Xin, Xiao-Na; Zhou, Hong; Ma, Xu

    2017-01-01

    A cross-sectional analysis of prevalence of hepatitis B virus infection (HBV) among rural couples was conducted between 2010 and 2014. Serologic HBV markers, including hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), were tested. Primary outcome of interest comprised HBsAg positivity in couples (both positive: F+M+, only wife positive: F+M−, only husband positive: F−M+), and secondary outcome consisted of prevalence and risk factors of HBsAg positivity among husbands or wives. Of 14,816,300 couples included, 0.7% were F+M+; 6.3% were F−M+; 4.4% were F+M−, resulting in the overall seroprevalence of 11.4%. Individually, 6.1% were HBsAg positive with a higher rate seen in husbands (7.0%) than in wives (5.2%). Wife’s HBeAg(+)/HBsAg (+) (AOR = 2.61), HBeAg(−)/HBsAg (+) (AOR = 2.23), positivity of syphilis (AOR = 1.50), living in a high-risk region (AOR = 1.46) were significantly predictors of HBsAg positivity in husbands. Prevalence and predictors of HBsAg positivity in wives had similar results. Our data show a high burden and discordant pattern of HBV infection in rural couples, and partner’s double positivity of HBeAg and HBsAg was the most significant factor of HBV infection in couples. A comprehensive strategy that emphasizes vaccination and education is needed. PMID:28220812

  3. Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg.

    PubMed

    Marcondes, Jackson; Hansen, Ekkehard

    2008-12-01

    The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L.) using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons with Agrobacterium tumefaciens harboring the recombinant plasmid. It is the first description of a lettuce Brazilian variety 'Vitória de Verão' genetically modified.

  4. Clinical features of HBsAg seroclearance in hepatitis B virus carriers in South Korea: A retrospective longitudinal study

    PubMed Central

    Park, Young Min; Lee, Seong Gyu

    2016-01-01

    AIM To investigate the characteristic features of hepatitis B surface antigen (HBsAg) seroclearance among Korean hepatitis B virus (HBV) carriers. METHODS Carriers with HBsAg seroclearance were selected by analyzing longitudinal data collected from 2003 to 2015. The period of time from enrollment to the negative conversion of HBsAg (HBsAg-NC) was compared by stratifying various factors, including age, sex, hepatitis B e antigen (HBeAg), HBV DNA, sequential changes in the signal-to-cutoff ratio of HBsAg (HBsAg-SCR), as measured by qualitative HBsAg assay, and chronic liver disease on ultrasonography (US-CLD). Quantification of HBV DNA and HBsAg (HBsAg-QNT) in the serum was performed by commercial assay. RESULTS Among the 1919 carriers, 90 (4.7%) exhibited HBsAg-NC at 6.2 ± 3.6 years after registration, with no differences observed among the different age groups. Among these carriers, the percentages of those with asymptomatic liver cirrhosis (LC) and hepatocellular carcinoma (HCC) at registration were 31% and 7.8%, respectively. The frequency of HBsAg-NC significantly differed according to the HBV DNA titer and US-CLD. HBeAg influenced HBsAg-NC in the 40-50 and 50-60 year age groups. HBsAg-SCR < 1000 was correlated with an HBsAg-QNT < 200 IU/mL. A gradual decrease in the HBsAg-SCR to < 1000 predicted HBsAg-NC. Six patients developed HCC after registration, including two before and four after HBsAg-NC. The rate at which the patients developed new HCC after HBsAg seroclearance was 4.8%. LC with excessive drinking and vertical infection were found to be risk factors for HCC in the HBsAg-NC group. CONCLUSION HCC surveillance should be continued after HBsAg seroclearance. An HBsAg-SCR < 1000 and its decrease in sequential testing are worth noting as predictive markers of HBsAg loss. PMID:27956808

  5. Mutation in the S gene a determinant of the hepatitis B virus associated with concomitant HBsAg and anti-HBs in a population in Northeastern Brazil.

    PubMed

    de Campos Albuquerque, Ingrid; Sousa, Marinilde Teles; Santos, Max Diego Cruz; Nunes, Jomar Diogo Costa; Moraes, Maria Josélia Diniz; Gomes-Gouvêa, Michele Soares; Pinho, João Renato Rebelo; Carrilho, Flair José; Fonseca, Lena Maria Barros; de Sousa Paiva Ferreira, Adalgisa

    2017-03-01

    Mutations in the a determinant of S gene may develop co-existence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in the serum of infected hepatitis B virus (HBV) individuals. Mutations in this region may change the antigenicity of HBsAg, which in turn, lead to escape of neutralizing action of anti-HBs antibodies. This study identified individuals with concomitant HBsAg and anti-HBs serological markers in individuals of Maranhão, Northeastern Brazil. Samples from a population-based study were evaluated for HBsAg, anti-HBs, and anti-HBc, and those that tested positive for simultaneous HBsAg and anti-HBs were submitted to HBV DNA quantification and S gene characterization by Sanger sequencing. Mutations were investigated in the a determinant located in major hydrophilic region (MHR) of the S gene. Among 3,984 samples analyzed, 92 (2.3%) were positive for HBsAg and three had the atypical HBsAg and anti-HBs-positive profile (3.26%). The frequency of HBsAg and anti-HBs co-existence was similar to previous studies. Only one individual harbored mutation in the S gene a determinant associated with this profile. Little is known about this phenomenon; however, studies as ours may contribute for future enlightenment of this important issue. J. Med. Virol. 89:458-462, 2017. © 2016 Wiley Periodicals, Inc.

  6. An Analysis of the Centaur Ground Processing System at the Kennedy Space Center/Cape Canaveral AFS.

    DTIC Science & Technology

    1985-12-01

    three TTF/four CISS model did even better with an output of 38 flights. This configuration was processing Centaur vehicles as fast as they arrived as...ACT,RLOGN(1.610,0.7782)*3; VENT SYS FUNCT CK FREE,CCLS,4; RELEASE CCLS E-4 ACT,, ,N51C; ACT,RLOGN(1.610,0.7782)*3,,N22AK; INSTL FORWORD BULKHEAD INSUL

  7. 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.

  8. 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

  9. 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

  10. VizieR Online Data Catalog: Visible colors of Centaurs and KBOs (Peixinho+, 2015)

    NASA Astrophysics Data System (ADS)

    Peixinho, N.; Delsanti, A.; Doressoundiram, A.

    2015-02-01

    Table 2: significant Spearman-rho correlations detected between all colors and all orbital parameters of Centaurs, scattered disk objects, scattered or detached objects, Plutinos, other resonants, classical KBOs, binary or multiple KBOs, KBOs (without Haumea family and retrograde orbits), all objects (also without Haumea family and retrograde orbits), and KBOs except classical KBOs (also without Haumea family and retrograde orbits). First and second columns indicate the variables, third column the number of objects with both variables measured, forth column indicate the correlation value and its 68.2% error interval, fifth column indicates the p-value of the correlation, sixth column indicate the equivalent confidence level of the p-value in Gaussian sigmas, columns seven to nine indicate the detail of the False Discovery Correction for confidence levels of 2.5σ and 3σ (see Sect. 3.4), tenth column indicates the maximum detectable rho at a 2.5σ confidence level with a 10% risk of missing it, eleventh column indicates the maximum detectable rho at a 3σ confidence level with a 10% risk of missing it (see Sect. 3.2) Table 5: Compilation of R-band absolute magnitude, not corrected for the phase-angle, of Spectral gradient, B-V, V-R, R-I, V-I, B-I, B-R, and corresponding orbital and orbital related parameters of 366 Centaurs and KBOs. For each object/observation, we computed the reflectance spectrum using equation (3) from Delsanti et al. (2001A&A...380..347D), when 2 or more filters were available. The resulting spectra were manually checked, and obviously deviant data from a given filter were removed from the dataset. Color indexes are computed within one given epoch, leading to colors obtained from "simultaneous" photometry (the different bands were observed over a maximum timespan of 2 hours). Then the average colors indexes and their one σ errors from different papers and epochs are computed for each object using equations (1) and (2) from Hainaut and Delsanti

  11. Short-term variability of a sample of 29 trans-Neptunian objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Thirouin, A.; Ortiz, J. L.; Duffard, R.; Santos-Sanz, P.; Aceituno, F. J.; Morales, N.

    2010-11-01

    Aims: We attempt to increase the number of trans-Neptunian objects (TNOs) whose short-term variability has been studied and compile a high quality database with the least possible biases, which may be used to perform statistical analyses. Methods: We performed broadband CCD photometric observations using several telescopes (the 1.5 m telescope at Sierra Nevada Observatory, the 2.2 m Calar Alto telescope and the 2.5 m INT on La Palma). Results: We present the results of 6 years of observations, reduced and analyzed with the same tools in a systematic way. We report completely new data on 15 objects, for 5 objects we present a new analysis of previously published results plus additional data and for 9 objects we present a new analysis of data already published. Lightcurves, possible rotation periods, and photometric amplitudes are reported for all of them. The photometric variability is smaller than previously thought: the mean amplitude of our sample is 0.1 mag and only around 15% of our sample has a larger variability than 0.15 mag. The smaller variability seems to be caused by a bias of previous observations. We find a very weak trend of faster spinning objects towards smaller sizes, which appears to be consistent with the smaller objects being more collisionally evolved, but may also be a specific feature of the Centaurs, the smallest objects in our sample. We also find that the smaller the objects, the larger their amplitude, which is also consistent with the idea that small objects are more collisionally evolved and thus more deformed. Average rotation rates from our work are 7.5 h for the whole sample, 7.6 h for the TNOs alone and 7.3 h for the Centaurs. Maxwellian fits to the period distribution yield similar results. Table 1 and Appendix are only available in electronic form at http://www.aanda.orgTable 3 is available in electronic form in the Center of astronomical Data of Strasbourg cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb

  12. 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.

  13. Evaluation of LIAISON® XL system for HBsAg, and anti-HCV and anti-HIV/Ag p24.

    PubMed

    De Paschale, Massimo; Manco, Maria Teresa; Belvisi, Luisa; Cagnin, Debora; Cerulli, Teresa; Paganini, Alessia; Arpino, Olivia; Cianflone, Annalisa; Agrappi, Carlo; Mirri, Paola; Clerici, Pierangelo

    2017-03-01

    The aim of this study was to compare the data obtained using the new LIAISON® XL chemiluminescence system to search for HBsAg, anti-HCV, and anti-HIV1-2/p24 Ag with those obtained using the VITROS system currently adopted by the Microbiology Unit of the Hospital of Legnano. Routine samples of patients who were referred by practitioners for the determination of HBsAg (1,000 samples) and/or anti-HCV (1,002 samples) and/or anti-HIV1-2 (995 samples) were simultaneously analyzed using both systems. The concordant positive and discordant samples were re-examined for confirmation by means of an HBsAg neutralization assay, anti-HCV immunoblot, or anti-HIV1-2 Western blot; HBV-DNA, or HCV-RNA or HIV-RNA was also sought in the discordant samples. Samples of patients known to be positive were tested (100 HBsAg positive, 100 anti-HCV positive, and 100 HIV 1-2 positive) as well throughout treatment, with viremia levels becoming undetectable after treatment. The HBsAg, anti-HCV, and anti-HIV1-2 concordance between the two systems in routine series was respectively 99.8%, 98.5% and 99.7%, and 100% for all markers in samples known positive. The various molecular biology and confirmatory tests of the discordant samples were all negative (except for one anti-HCV positive sample). Measure of Cohen's kappa coefficient for HBsAg, anti-HCV, and anti-HIV gave K values of respectively 0.992, 0.946, and 0.980. In conclusion, the performance of the LIAISON® XL system in the routine laboratory determination for all three markers was comparable with that of the VITROS system. J. Med. Virol. 89:489-496, 2017. © 2016 Wiley Periodicals, Inc.

  14. Presence of HBsAg and anti-HBs in patients with primary liver cancer or hepatic metastases.

    PubMed

    Nastac, E; Stoian, M; Iosipenco, M; Iordache, C

    1985-01-01

    The presence of HBsAg was detected in the serum of 1 out of 13 patients with chronic hepatitis, in 2 out of the 7 patients with liver metastases, but in none of the 10 patients with hepatocellular carcinoma (HCC) investigated. HBsAg could be visualized by orcein staining in the liver cells of 66.6% of the HCC patients, in 50% of the patients with liver metastases and in 40% of the patients with liver cirrhosis. The prevalence of anti-HBs was low both in HCC patients and in the control groups. The possible significance of these findings is discussed.

  15. 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.

  16. 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.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1987-09-01

    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.

  19. Evolution of full-length genomes of HBV quasispecies in sera of patients with a coexistence of HBsAg and anti-HBs antibodies.

    PubMed

    Zhou, Tai-Cheng; Li, Xiao; Li, Long; Li, Xiao-Fei; Zhang, Liang; Wei, Jia

    2017-04-06

    Although the evolutionary changes of viral quasispecies are correlated to the pathological status of a disease, little is known in the coexistence of hepatitis B surface antigen (HBsAg) and antibodies to these antigens (anti-HBs). To examine evolutionary changes in hepatitis B virus (HBV) and their relationship to the coexistence of HBsAg and anti-HBs antibodies, HBV genomes in patients with a coexistence of HBsAg and anti-HBs antibodies (experimental group) and HBsAg positive without anti-HBs (control group) were assessed. Our results showed that quasispecies diversity was significantly higher in the experimental group for large HBsAg (LHBsAg), middle HBsAg (MHBsAg), and HBsAg genes. LHBsAg harbored dN/dS values eight times higher in the experimental group; however, the mean dN/dS ratios in genes HbxAg, Pol and PreC/C of the experimental patients had an opposite trend. Phylogenetic trees in the experimental group were more complex than the control group. More positive selection sites, mutations and deletions were observed in the experimental group in specific regions. Furthermore, several amino acid variants in epitopes were potentially associated with the immune evasion. In conclusion, cumulative evolutionary changes in HBV genome that facilitate immune evasion provide insights into the genetic mechanism of a coexistence of HBsAg and anti-HBs antibodies.

  20. Clinical and pathological study of asymptomatic HBsAg carriers in Chile.

    PubMed Central

    Velasco, M; González-Cerón, M; de la Fuente, C; Ruiz, A; Donoso, S; Katz, R

    1978-01-01

    A clinical, biochemical, and pathological study was performed in 38 chronic HBsAg carriers. The study group is a part of 393 carriers found among 117 705 voluntary blood donors at the National Blood Bank, Hospital del Salvador, Santiago, Chile. None of the 38 carriers had a past history of illicit drug abuse, hepatitis, or work involving a high risk of hepatitis B virus infection. Ten individuals had a normal liver biopsy, 17 reactive non-specific hepatitis, one fatty changes, four chr onic persistent hepatitis, one aggressive hepatitis, two post-necrotic cirrhosis, and three alcoholic cirrhosis. There was not a close correlation between liver function test and liver histology. The most significant laboratory finding was the postivity of alpha fetoprotein in two cases. During the follow-up the two alpha fetoprotein patients presented a hepatocarcinoma 12 and 14 months after admission to the study. PMID:680591

  1. [Research on HBsAg: comparison between two methods of the third generation, RPHA and IEA].

    PubMed

    Moretti, R; Vujovic, A; Benda, N

    1982-06-01

    Two tests of the 3rd generation were evaluated for the identification of HBsAg: the reverse hemoagglutination and the enzymatic immunoassay. The results of the study, carried out on 2,434 sera of occasional and periodic donors, have been slightly discordant. It was confirmed the greater sensibility of the IEA test over the RHA and there was a high incidence of false positive results of the IEA test probably caused by the presence in the sera of an elevated concentration of lipid and/or Hb. However, we can consider the RHA a useful test adaptable as an emergency test while the IEA method, being more sensible, can be used as a basic screening test.

  2. Renal involvement in a syndrome of vasculitis complicating HBsAg negative cirrhosis of the liver.

    PubMed

    Montoliu, J; Darnell, A; Grau, J M; Torras, A; Revert, L

    1985-01-01

    Six HBsAg negative patients with cirrhosis of the liver (CL) presented with recurrent bouts of palpable purpura in the legs due to small vessel leucocytoclastic vasculitis. In addition, all patients had renal failure, proteinuria and microhaematuria. Renal biopsy disclosed either diffuse proliferative (3 cases) or focal necrotising glomerulonephritis with crescents (2 cases). One patient had IgM-IgG mixed cryoglobulinaemia (type II). Four patients died of complications of their CL. Hepatocellular carcinoma was found in 1 case. In the patient without renal biopsy renal function improved following steroids and cyclophosphamide. The pathogenesis of this syndrome of cutaneous vasculitis with severe glomerular involvement in CL is unknown but could be immune-complex mediated.

  3. Biochemical and Biophysical Characterization of Maize-derived HBsAg for the Development of an Oral Vaccine

    PubMed Central

    Shah, Shweta; Hayden, Celine A.; Fischer, Maria E.; Rao, A.Gururaj; Howard, John A.

    2015-01-01

    Although a vaccine against hepatitis B virus (HBV) has been available since 1982, it is estimated that 600,000 people die every year due to HBV. An affordable oral vaccine could help alleviate the disease burden and to this end the hepatitis B surface antigen (HBsAg) was expressed in maize. Orally delivered maize material induced the strongest immune response in mice when lipid was extracted by CO2 supercritical fluid extraction (SFE), compared to full fat and hexane-extracted material. The present study provides a biochemical and biophysical basis for these immunological differences by comparing the active ingredient in the differently treated maize material. Purified maize-derived HBsAg underwent biophysical characterization by gel filtration, transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-CD, and fluorescence. Gel filtration showed that HBsAg forms higher-order oligomers and TEM demonstrated virus-like particle (VLP) formation. The VLPs obtained from SFE were more regular in shape and size compared to hexane or full fat material. In addition, SFE-derived HBsAg showed the greatest extent of α-helical structure by far UV-CD spectrum. Fluorescence experiments also revealed differences in protein conformation. This work establishes SFE-treated maize material as a viable oral vaccine candidate and advances the development of the first oral subunit vaccine. PMID:26519888

  4. Biochemical and biophysical characterization of maize-derived HBsAg for the development of an oral vaccine.

    PubMed

    Shah, Shweta; Hayden, Celine A; Fischer, Maria E; Rao, A Gururaj; Howard, John A

    2015-12-15

    Although a vaccine against hepatitis B virus (HBV) has been available since 1982, it is estimated that 600,000 people die every year due to HBV. An affordable oral vaccine could help alleviate the disease burden and to this end the hepatitis B surface antigen (HBsAg) was expressed in maize. Orally delivered maize material induced the strongest immune response in mice when lipid was extracted by CO2 supercritical fluid extraction (SFE), compared to full fat and hexane-extracted material. The present study provides a biochemical and biophysical basis for these immunological differences by comparing the active ingredient in the differently treated maize material. Purified maize-derived HBsAg underwent biophysical characterization by gel filtration, transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-CD, and fluorescence. Gel filtration showed that HBsAg forms higher-order oligomers and TEM demonstrated virus-like particle (VLP) formation. The VLPs obtained from SFE were more regular in shape and size compared to hexane or full fat material. In addition, SFE-derived HBsAg showed the greatest extent of α-helical structure by far UV-CD spectrum. Fluorescence experiments also revealed differences in protein conformation. This work establishes SFE-treated maize material as a viable oral vaccine candidate and advances the development of the first oral subunit vaccine.

  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. Mutations in surface and polymerase gene of chronic hepatitis B patients with coexisting HBsAg and anti-HBs

    PubMed Central

    Lu, Hai-Ying; Zeng, Zheng; Xu, Xiao-Yuan; Zhang, Nai-Lin; Yu, Min; Gong, Wei-Bo

    2006-01-01

    AIM: To investigate the clinical significance and presence of mutations in the surface (S) and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS: Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, 11 were both positive for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV surface antigen (anti-HBs), 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200 μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced. RESULTS: Forty-one mutations were found within the surface gene protein of HBV in 15 patients (10 with coexisting HBsAg and anti-HBs). Six (14.6%) out of 41 mutations were located at “α” determinant region in 5 patients (4 positive for HBsAg and anti-HBs). Eleven mutations (26.8%) occurred in the downstream or upstream of “α” determinant region. Lamivudine (LMV)-selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions (196, 198, 199) of the surface protein and in YMDD motif (M204I/V) of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA levels. CONCLUSION: Besides mutations in the “α” deter-minant region, mutations at downstream or upstream of the “α” determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs. PMID:16830379

  7. Anti-HIV seropositivity was related to HBsAg seropositivity among injecting drug users in Taiwan.

    PubMed

    Hsieh, Meng-Hsuan; Hsieh, Ming-Yen; Huang, Chung-Feng; Yeh, Ming-Lun; Wang, Shu-Chi; Yang, Jeng-Fu; Chang, Ko; Lin, Wei-Ru; Lin, Chun-Yu; Chen, Tun-Chieh; Huang, Jee-Fu; Dai, Chia-Yen; Tsai, Jih-Jin; Chuang, Wan-Long; Yu, Ming-Lung

    2016-02-01

    In Taiwan, the number of new cases of human immunodeficiency virus (HIV) infection via drug injection has been increasing since 2003. Due to HIV and hepatitis B virus (HBV) having similar transmission routes, HBV and HIV infections among injecting drug users (IDUs) has become an important public health issue. The aim of this study was explore the prevalence of HBV infection among IDUs with and without HIV infection, and examine whether HIV infection is associated with HBV infection among IDUs in Southern Taiwan. We enrolled 566 IDUs, including 87 anti-HBV positive IDUs and 479 anti-HBV negative IDUs, and also analyzed the results of liver function tests, HBV DNA, anti-HIV, HIV RNA, and CD4 cell count. The results showed that the prevalence of HBV infection among IDUs was 15.4%. The prevalence of hepatitis B surface antigen (HBsAg) was higher among individuals born before 1985 (15.9% vs. 4.0%), but this was not significant. Anti-HIV seropositivity was related to HBsAg seropositivity [odds ratio (OR) = 2.47, 95% confidence interval = 1.26-4.82, p = 0.008). Anti-HCV and anti-HIV were risk factors for abnormal alanine aminotransferase (ALT; OR = 2.11, 95% confidence interval = 1.005-4.42, p = 0.048 and OR = 1.47, 95% confidence interval = 1.02-2.10, p = 0.04, respectively), and HBsAg was not a factor related to abnormal ALT. In conclusion, the prevalence of HBV infection was similar in the general population and in IDUs, and due to anti-HIV seropositivity being significantly related to HBsAg seropositivity, HBV infection among IDUs is still important. We suggest that for IDUs, HBsAg should be monitored closely.

  8. New amino acid changes in drug resistance sites and HBsAg in hepatitis B virus genotype H.

    PubMed

    Fernández-Galindo, D A; Sánchez-Ávila, F; Bobadilla-Morales, L; Gómez-Quiróz, P; Bueno-Topete, M; Armendáriz-Borunda, J; Sánchez-Orozco, L V

    2015-06-01

    Long-term treatment with retrotranscriptase (RT) inhibitors eventually leads to the development of drug resistance. Drug-related mutations occur naturally and these can be found in hepatitis B virus (HBV) carriers who have never received antiviral therapy. HBsAg are overlapped with RT domain, thus nucleot(s)ide analogues (NAs) resistance mutations and naturally-occurring mutations can cause amino acid changes in the HBsAg. Twenty-two patients with chronic hepatitis B were enrolled; three of them were previously treated with NAs and 19 were NAs-naïve treated. HBV reverse transcriptase region was sequenced; genotyping and analysis of missense mutations were performed in both RT domain and HBsAg. There was predominance of genotype H. Drug mutations were present in 18.2% of patients. Classical lamivudine resistance mutations (rtM204V/rtL180M) were present in one naïve-treatment patient infected with genotype G. New amino acid changes were identified in drug resistance sites in HBV strains from patients infected with genotype H; rtQ215E was present in two naïve-NAs treatment patients and rtI169M was identified in a patient previously treated with lamivudine. Mutations at sites rt169, rt204, and rt215 resulted in the Y161C, I195M, and C206W mutations at HBsAg. Also, new amino acid changes were identified in B-cell and T-cell epitopes and were more frequent in HBsAg compared to RT domain. In conclusion, new amino acid changes at antiviral resistance sites, B-cell and T-cell epitopes in HBV genotype H were identified in Mexican patients.

  9. Signatures Of A Putative Planetary Mass Solar Companion On The Orbital Distribution Of Tno's And Centaurs

    NASA Astrophysics Data System (ADS)

    Gomes, Rodney S.; Soares, J. S.

    2012-05-01

    Gomes et al. 2006 (Icarus 184, 589) show that a planetary mass solar companion (PMSC) can produce orbits in an inner Oort cloud that can account for Sedna's orbit. On the other hand, one should expect that this faraway planet would also produce some peculiar orbital distribution for distant TNO's and Centaurs. A pair of interesting orbits in this respect are those of 2006 SQ372 and 2000 OO67. These objects have very large semimajor axes and perihelion between Uranus and Neptune orbits. It has been claimed that a likely source for 2006 SQ372 is the Oort cloud. Yet a PMSC has an important effect on objects at inner Oort cloud distances, say between 300 AU and 2000 AU, to make their perihelion distances to continually oscillate with a large enough amplitude to account for objects both inside and outside Neptune's orbit. This naturally produces an extra amount of TNO's with semimajor axes between 300 and 2000 AU and perihelion inside Neptune's orbit, like 2006 SQ372 and 2000 OO67. This signature should be found in present observations. To deal with this problem we construct a numerical simulator and apply it to populations of distant TNO's produced by numerical integration of planetesimals and planets according to the Nice model, either including or not a PMSC. With the results from the numerical simulator we compare the model with and without the PMSC with observations. We conclude that a PMSC is compatible with the existence of 2006 SQ372 and 2000 OO67 and, in fact, although not conclusively, we can also claim that the observations of 2006 SQ372 and 2000 OO67, compared to all other scattered objects, would be lucky events if no PMSC exists.

  10. How can we explain the presence of rings around the Centaur Chariklo?

    NASA Astrophysics Data System (ADS)

    El Moutamid, Maryame; Kral, Quentin; Sicardy, Bruno; Charnoz, Sebastien; Roques, Françoise; Nicholson, Philip D.; Burns, Joseph A.

    2014-05-01

    Recently two rings have been detected around the small body known as (10199) Chariklo (Braga-Ribas et al. 2014). Chariklo is the largest Centaur, with a diameter of 250 km and a dynamical lifetime estimated at less than 10 Myrs, given its orbital position. By the technique of multi-chord stellar occultation, Felipe Braga-Ribas and colleagues observed two dense rings around this asteroid separated by a gap of 14 km, with widths of 7 km and 3 km, optical depths 0.4 and 0.06, and radii from the central body of 391 km and 405 km, respectively. This raises several questions concerning the stability of such a ring system and its origin. In this talk we will try to present the first attempt at answering these issues from a dynamical point of view.The presence of rings around such a body is an exciting but surprising result. Several scenarios could account for their formation: - A violent impact such as the Moon-forming collision could potentially lead to the creation of a ring. - The potential presence of larger bodies surviving the initial impact and acting as shepherd satellites for the rings could make it long-lived. - Another scenario involves a small satellite (less than 2 km) which is destroyed by tidal effects as it migrates inwards to the Roche limit... We hope to present preliminary results of these studies. This diminutive ring system opens the way to a new view of the evolution of small bodies as it is hard to believe that Chariklo is an isolated case.

  11. 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.

  12. Nationwide seroepidemiology of hepatitis B virus infection in South Korea in 2009 emphasizes the coexistence of HBsAg and anti-HBs.

    PubMed

    Lee, Byung Seok; Cho, Yong Kyun; Jeong, Sook-Hyang; Lee, Joon Hyeok; Lee, Don; Park, Neung Hwa; Ki, Moran

    2013-08-01

    Hepatitis B virus (HBV) infection is the major cause of chronic liver disease in Korea. This study investigated the seroprevalence of HBV infection with an emphasis on the coexistence of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs). In all, 290,212 people undergoing health check-up examinations in 29 institutions during 2009 were recruited. The crude seroprevalences of HBsAg and anti-HBs was adjusted by age, sex, and geographic area using the 2009 estimated population of Korea. The adjusted seroprevalences of HBsAg and anti-HBs was 4.0% and 73.5%, respectively. Males showed higher HBsAg positivity and lower anti-HBs positivity than females (P<0.001). HBsAg positivity increased with age from 3.5% in people 20-29 years old to 4.8% in people 40-49 years old, followed by a decrease in people ≥ 50 years old. HBsAg positivity in Southern provinces (4.5%) including Jeju (5.9%), was significantly higher than that in Central provinces (3.6%; P<0.001). Interestingly, HBsAg and anti-HBs coexisted in 0.1% of the total subjects and in 2.9% of the HBsAg-positive group, showing distinct age distribution and higher alanine aminotransferase levels than those of the group positive for only HBsAg. In conclusion, the seroprevalence of HBsAg and anti-HBs in Korea varies significantly by age, sex and geographical location and coexisted in 2.9% of HBsAg-positive subjects. Continuous monitoring of seroepidemiology may facilitate the eventual eradication of HBV infection.

  13. Understanding early serum hepatitis D virus and HBsAg kinetics during pegylated interferon-alfa therapy via mathematical modeling

    PubMed Central

    Guedj, Jeremie; Rotman, Yaron; Cotler, Scott J.; Koh, Christopher; Schmid, Peter; Albrecht, Jeff; Haynes-Williams, Vanessa; Liang, Jake T.; Hoofnagle, Jay H.; Heller, Theo; Dahari, Harel

    2014-01-01

    There is little information on the early kinetics of hepatitis delta virus (HDV) and hepatitis B surface antigen (HBsAg) during interferon-α therapy. Here a mathematical model was developed and fitted to frequent HDV and HBsAg kinetic data from 10 patients during the first 28 weeks of pegylated-interferon-α2a (peg-IFN) therapy. Three patients achieved a complete virological response (CVR), defined as undetectable HDV 6 months after treatment stopped with loss of HBsAg and anti-HBsAg seroconversion. After initiation of therapy a median delay of 9 days (interquartile range IQR:[5;15]) was observed with no significant changes in HDV level. Thereafter, HDV declined in a biphasic manner, where a rapid first-phase lasting for 25 days (IQR:[23;58]) was followed by a slower or plateau second-phase. The model predicts that the main effect of peg-IFN is to reduce HDV production/release with a median effectiveness of 96% (IQR:[93;99.8]). Median serum HDV half-life (t1/2) was estimated to 2.9 days (IQR:[1.5;5.3]) with pretreatment production and clearance of about 1010 (IQR:[109.8-1010.8]) virions/day. None of the patients with flat 2nd phase in HDV achieved CVR. HBsAg kinetics of decline paralleled the second-phase of HDV decline consistent with HBsAg-productive-infected cells being the main source of production of HDV, with a median t1/2 of 135 days (IQR:[20-460]. The interferon lambda-3 polymorphism (rs12979860) was not associated with kinetic parameters. Conclusions Modeling results provide insights into HDV-host dynamics, the relationship between serum HBsAg levels and HBsAg-infected cells, IFN's mode of action and its effectiveness. The observation that a flat second phase in HDV and HBsAg kinetics was associated with failure to achieve CVR provides the basis to develop early stopping rules during peg-IFN treatment in HDV-infected patients. PMID:25098971

  14. Dynamical analyses on the transitivity from JFC and Centaur regions to NEAs with Tisserand parameters from 2 to 3

    NASA Astrophysics Data System (ADS)

    Kaplan, Murat; Erece, Orhan; Aslan, Gürkan; Eker, Zeki

    2016-12-01

    We study the contribution of JFC (Jupiter family comet) and Centaur regions to the NEA (near Earth asteroid) population having Tisserand parameters for Jupiter between 2 and 3. We define a region for JFCs (aphelion distance (Q) > 4.61 au, perihelion distance (q) < 4.95 au, > 1.3 au) and we check the contributions of selected bodies (JFCs, Centaurs, Halley-type comets (HTCs), some elliptic comets, and some outer main belt asteroids) from various regions to the NEA region. Additionally, we integrated NEAs with Tisserand parameters for Jupiter (TJ) between 2 and 3 and their clones backward in time to see whether there was a strong dynamical path between those NEAs and the defined JFC region. As a result, 35.1% of the orbits from the defined JFC region turned out to be Earth-crossing orbits for forward integrations, while 66.7% of NEAs (2

  15. 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.

  16. 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

  17. Purification of HBsAg produced by the human hepatoma cell line PLC/PRE/5 by affinity chromatography using monoclonal antibodies and application for ELISA diagnostic.

    PubMed

    Merten, O W; Reiter, S; Scheirer, W; Katinger, H

    1983-01-01

    The human cell line PLC/PRF/5 (5) was used for the production of hepatitis B surface antigen subtype ad (HBsAg ad) and purified by affinity chromatography (AC) with monoclonal antibodies (mAb). mAb to HBsAg from mouse ascites have been purified by Protein A - AC prior coupling to AH-Sepharose 4B (Pharmacia). The combined procedure of ammonium-sulphate-precipitation of HBsAg from culture supernatants and immunosorbent-AC leads to approx. 700-fold purification. ELISA results using the mAb and the HBsAg for diagnostics of human serum, positive for anti-HBsAg-antibodies correlate with the RIA (AUSAB, Abbott).

  18. 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.

  19. Hepatitis B surface antigen (HBsAg) expression in plant cell culture: Kinetics of antigen accumulation in batch culture and its intracellular form.

    PubMed

    Smith, Mark L; Mason, Hugh S; Shuler, Michael L

    2002-12-30

    The production of edible vaccines in transgenic plants and plant cell culture may be improved through a better understanding of antigen processing and assembly. The hepatitis B surface antigen (HBsAg) was chosen for study because it undergoes substantial and complex post-translational modifications, which are necessary for its immunogenicity. This antigen was expressed in soybean (Glycine max L. Merr. cv Williams 82) and tobacco NT1 (Nicotiana tabacum L.) cell suspension cultures, and HBsAg production in batch culture was characterized. The plant-derived antigen consisted predominantly of disulfide cross-linked HBsAg protein (p24(s)) dimers, which were all membrane associated. Similar to yeast, the plant-expressed HBsAg was retained intracellularly. The maximal HBsAg titers were obtained with soybean suspension cultures (20-22 mg/L) with titers in tobacco cultures being approximately 10-fold lower. For soybean cells, electron microscopy and immunolocalization demonstrated that all the HBsAg was localized to the endoplasmic reticulum (ER) and provoked dilation and proliferation of the ER network. Sucrose gradient analysis of crude extracts showed that HBsAg had a complex size distribution uncharacteristic of the antigen's normal structure of uniform 22-nm virus-like particles. The extent of authentic epitope formation was assessed by comparing total p24(s) synthesized to that reactive by polyclonal and monoclonal immunoassays. Depending on culture age, between 40% and 100% of total p24(s) was polyclonal antibody reactive whereas between 6% and 37% was recognized by a commercial monoclonal antibody assay. Possible strategies to increase HBsAg production and improve post-translational processing are discussed.

  20. 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.

  1. 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

  2. The Zodiacal Dust Cloud Populations at Saturn: signs of Centaurs activity ? The point of view of CASSINI-CDA

    NASA Astrophysics Data System (ADS)

    Altobelli, Nicolas; Kempf, Sascha; Moragas, Georg; Srama, Ralf

    2013-04-01

    We present a preliminary analysis of the entrance charge grid (EG) subsystem data of the CASSINI-Cosmic Dust Analyzer (CDA). This subsystem can detect micron to tens of micron-sized particles through the electrostatic charge induced on a grid of conductive wires located at the entrance of the CDA instrument. An analysis of the induced electric signals on the wires allow us to retrieve the direction and speed of dust grains with a precision higher than any other CDA subsystems. We have identified and analyzed all CDA-EG events identified at 2 Saturn Radii from Saturn's equatorial plane and all events beyond Titan's orbit, looking specifically for the signature of particles on hyperbolic orbit with respect to Saturn (and hence, of exogenous origin). The exogenous origin could be confirmed for a fraction of the EG events and their heliocentric orbital elements derived, at the time they crosses the Hill's sphere boundary, by performing a backward propagation of their trajectory in the Saturn's system. The values of the grain orbital elements suggest a connection with parent bodies like Centaurs objects, while Jupiter Family Comets can only explain a minority of the detected dust grains. Centaur objects have been recently the focus of observation campaigns, as cometary-like activity was identified for a few of them, and hence, are a potential significant source of dust in the outer Solar System. We discuss our results, trying in particular to understand how other expected dust grain populations like Kuiper belt collisional products could also contribute to our data set.

  3. [A retrospective study on HBsAg clearance rate after antiviral therapy in children with HBeAg-positive chronic hepatitis B aged 1-7 years].

    PubMed

    Zhu, S S; Dong, Y; Xu, Z Q; Wang, L M; Chen, D W; Gan, Y; Wang, F C; Yan, J G; Cao, L L; Wang, P; Zhang, H F

    2016-10-20

    Objective: To investigate the HBsAg clearance rate after antiviral therapy in children with HBeAg-positive chronic hepatitis B (CHB) aged 1-7 years. Methods: A retrospective analysis was performed for the HBsAg clearance rate in 293 children who were hospitalized in 302 Hospital of PLA from June 2006 to December 2013, met the inclusion criteria, received antiviral therapy, and were followed up for at least 6 months after the withdrawal of antiviral therapy. The t-test or the rank sum test was applied according to the distribution of continuous data, and the chi-square test was used for comparison of categorical data. Results: The HBsAg positive rate of children's mothers was 91.1%. In the age groups of >1-≤2 years, >2-≤3 years, >3-≤4 years, >4-≤5 years, >5-≤6 years, and >6-≤7 years, the HBsAg clearance rates were 66.1%, 65.5%, 45.7%, 41.3%, 20.6%, and 27.6%, respectively. There were significant differences in HBsAg clearance rate between the age groups of >1-≤3 years and >3-≤5 years, >1-≤3 years and >5-≤7 years, and >3-≤5 years and >5-≤7 years (P = 0.001, 0.000, and 0.008). Of all children, 64.8% were boys, among whom 41.1% achieved HBsAg clearance, and 35.2% were girls, among whom 61.2% achieved HBsAg clearance; there was a significant difference in HBsAg clearance rate between boys and girls (P = 0.001). The children with pretreatment alanine aminotransferase (ALT) levels of ≤80 IU/L, > 80 IU/L, ≤200 IU/L, and > 200 IU/L had HBsAg clearance rates of 40.7%, 51.2%, 47.6%, and 49.4%, respectively; there were no significant differences in HBsAg clearance rate between the ALT ≤80 IU/L and ALT > 80 IU/L groups and the ALT ≤200 IU/L and ALT > 200 IU/L groups (P = 0.101 and 0.778). There was no significant difference in HBsAg clearance rate between the pretreatment HBV DNA load < 1×10(7) IU/ml and ≥1×10(7) IU/ml groups (54.9% vs 46.7%, P = 0.286). Of all children, 14.2% had genotype B and an HBsAg clearance rate of 57.1%, and 85% had

  4. Exposition of hepatitis B surface antigen (HBsAg) on the surface of HEK293T cell and evaluation of its expression

    PubMed Central

    Mirian, Mina; Taghizadeh, Razieh; Khanahmad, Hossein; Salehi, Mansour; Jahanian-Najafabadi, Ali; Sadeghi-aliabadi, Hojjat; Kouhpayeh, Shirin

    2016-01-01

    Hepatitis B virus (HBV) is considered as a global health concern and hepatitis B surface antigen (HBsAg) is the most immunogenic protein of HBV. The purpose of this study was to evaluate the expression of HBsAg on the cell surface of human embryonic kidney cell line (HEK293T). After transformation of expression vector pcDNA/HBsAg to E.coli TOP10F’, plasmid was extracted and digested with BglII. Afterwards, the linearized vector was transfected to cells and treated with hygromycin B for 5 weeks to expand the resulted clonies. The permanent expression of HBsAg followed by flow cytometry uptill now about one year. Genomic DNA was extracted from transfected cells and the existence of HBsAg gene was assessed by PCR. Real-time RT-PCR was utilized to measure the expression at the RNA level and flow cytometery was carried out to assess protein expression. Insertion of HBsAg cDNA in HEK293T genome was confirmed by PCR. The results of real-time RT-PCR illustrated that each cell expresses 2275 copies of mRNA molecule. Flow cytometry showed that compared with negative control cells, 99.9% of transfected cells express HBsAg on their surface. In conclusion, stable expression of hepatitis B surface antigen on the membrane of HEK293T provides an accurate post-translational modification, proper structure, and native folding in contrast with purified protein from prokaryotic expression systems. Therefore, these exposing HBsAg cells are practical in therapeutic, pharmaceutical, and biological sets of research. PMID:27920818

  5. 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.

  6. 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.

  7. 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.

  8. Biological characteristics comparison of HBV rtA181T mutants with truncated or substituted HBsAg expression in vitro and in vivo model systems

    PubMed Central

    Zhou, Ling-Yun; Chen, En-Qiang; Wang, Meng-Lan; Chen, Lan-Lan; Liu, Cui-Ping; Zeng, Fan; Tang, Hong

    2016-01-01

    The hepatitis B virus(HBV) polymerase rtA181T mutation is selected during long-term antiviral therapy. As the polymerase gene completely overlaps with the envelope (S) gene, HBV rtA181T mutation also carries sW172 mutations. In this study, we investigated whether there were biological differences between rtA181T/sW172* (coding truncated HBsAg) and rtA181T/sW172L (coding substituted HBsAg) mutants. In cell experiments, a slight decline of viral replication was observed in both two mutants as compared to wild-type strains, but the levels of supernatant HBsAg and HBV DNA in rtA181T/sW172* were significantly lower than those in rtA181T/sW172L transfected cells. In animal experiments, we were amazed to find that viral replication in rtA181T/sW172* mutant increased and maintained significantly longer than that in rtA181T/sW172L mutant, while no significant difference was observed between rtA181T/sW172L and wild-type strains. Compared with wild-type strains, there were intracellular accumulations of HBsAg and HBcAg in rtA181/sW172* but none in rtA181/sW172L mutant strains. Importantly, we also found that truncated HBsAg could increase the activity of HBV core promoter, but substituted HBsAg could not. In summary, the characteristics of above two rtA181T mutants mentioned above were significantly different, and it is necessary and important for us to distinguish sW172* truncated mutation from sW172L substituted mutation. PMID:27976732

  9. [Dynamic expression profile of HBsAg according to hepatic parenchyma cells' volume at different liver fibrosis stages in the immune clearance phase].

    PubMed

    Wu, Zhe-bin; Cao, Hong; Liu, Ting; Wu, Ze-qian; Ke, Wei-min; Gao, Zhi-liang

    2012-10-01

    The aim of this study was to determine the dynamic expression profile of hepatitis B surface antigen (HBsAg) according to hepatic parenchyma cells' volume at different stages of liver fibrosis during the immune clearance phase. Eighty-nine patients with HBeAg-positive chronic hepatitis B (CHB) in the immune clearance stage were recruited for study. Each patient's serum HBsAg levels were detected by electrochemiluminescence. The serum HBsAg levels were apportioned according to hepatic parenchyma cells' volume at liver fibrosis stages 1, 2, 3, and 4 and compared by ANOVA. The unapportioned serum HBsAg levels (IU/mL) at liver fibrosis stages 1 (227.2+/-237.7), 2 (211.0+/-131.4), 3(300.1+/-144.6), and 4 (278.7+/-148.8) were not significantly different (all comparisons, P range: 0.061 to 0.759). However, when the serum HBsAg levels were apportioned by the same hepatic parenchyma cells' volume at liver fibrosis stages 1 (343.9+/-359.8), 2 (336.4+/-209.5), 3 (508.7+/-245.1), and 4 (525.2+/-274.8), the levels were significantly different (all comparisons, F = 3.045 and P = 0.033; stage 1 vs. 3, P = 0.041; stage 1 vs. 4, P = 0.046; stage 2 vs. 3, P = 0.028; stage 2 vs. 4, P = 0.034). During the immune clearance phase of chronic hepatitis B, increased HBsAg expression is associated with increased hepatic parenchyma cells' volume and progressive liver fibrosis stage.

  10. [Atypical serological profiles in hepatitis B infections: investigation of S gene mutations in cases with concurrently positive for HBsAg and anti-HBs].

    PubMed

    Aydın, Neriman; Kırdar, Sevin; Uzun, Nilgül; Eyigör, Mete; Sayan, Murat

    2016-10-01

    Hepatitis B virus (HBV) causes different clinical manifestations, ranging from asymptomatic carriage to fulminant or chronic hepatitis. Serological tests are widely used for the diagnosis of HBV infections to detect viral markers. However, facing with atypical serological profiles in some patients leads to problems in interpreting of the results and management of the patients. The aims of this study were to investigate the atypical serologic profiles seen in patients screened for HBV infection and the S gene mutations in patients with concurrent positivity of HBsAg and anti-HBs. A total of 592 sera from patients (332 male, 260 female; age range: 13-84 years, mean age: 43.9 years) prediagnosed as HBV infection between January to September 2013, and screened for HBV markers (HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc-IgM, anti-HBc-total and HBV-DNA) were included in the study. Of those samples 364 were screened only for HBsAg and anti-HBs markers. S gene mutations were investigated by direct sequencing method in sera which were concurrent positive for HBsAg and anti-HBs. In our study, 5.2% (31/592) of the sera yielded atypical serologic profiles. Of these 13 cases were concurrently positive for HBsAg and anti-HBs; nine were HBeAg positive, anti-HBe and HBV-DNA negative; eight were HBeAg, anti-HBe and HBV-DNA positive; and one was HBsAg and anti-HBs negative, anti-HBe and HBV-DNA positive. The rate of concurrent positivity of HBsAg and anti-HBs was 3.6% (13/364), while 76.9% (10/13) of those cases were also positive for HBV-DNA. DNA sequencing was performed for seven out of 10 samples which were positive for HBsAg, anti-HBs and HBV-DNA, however three samples were not used because of the low amounts. Sequence analysis of seven samples showed S gene mutations in two samples, one was sS143L with sS193L, a HBV vaccine escape mutation, and the other was sP120R, a HBV immune escape mutation. Of the patients 2.7% (10/364) was negative for both HBsAg and anti-HBs; in which

  11. 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.

  12. Human Cytokine Genetic Variants Associated With HBsAg Reverse Seroconversion in Rituximab-Treated Non-Hodgkin Lymphoma Patients

    PubMed Central

    Hsiao, Liang-Tsai; Wang, Hao-Yuan; Yang, Ching-Fen; Chiou, Tzeon-Jye; Gau, Jyh-Pyng; Yu, Yuan-Bin; Liu, Hsiao-Ling; Chang, Wen-Chun; Chen, Po-Min; Tzeng, Cheng-Hwai; Chan, Yu-Jiun; Yang, Muh-Hwa; Liu, Jin-Hwang; Huang, Yi-Hsiang

    2016-01-01

    Abstract Hepatitis B virus (HBV) reactivation has been noted in HBV surface antigen (HBsAg)-seronegative patients with CD20+ B-cell non-Hodgkin lymphoma (NHL) undergoing rituximab treatment. Clinically, hepatitis flares are usually associated with the reappearance of HBsAg (reverse seroconversion of HBsAg, HBV-RS). It is unclear whether human genetic factors are related to rituximab-associated HBV reactivation. Unvaccinated HBsAg-seronegative adults (n = 104) with CD20+ NHL who had received rituximab-containing therapy without anti-HBV prophylaxis were enrolled. Eighty-nine candidate single nucleotide polymorphisms (SNPs) of 49 human cytokine genes were chosen and were analyzed using the iPLEX technique. Competing risk regression was used to identify the factors associated with HBV-RS. Participants had a median age of 66.1 years and 56.7% were male (n = 59). The anti-HBs and anti-HBc positivity rates were 82.4% and 94.1%, respectively, among patients for whom data were available (approximately 81%). A mean of 7.14 cycles of rituximab therapy were administered, and a total of 14 (13.4%) patients developed HBV-RS. Nine SNPs showed significant differences in frequency between patients with or without HBV-RS: CD40 rs1883832, IL4 rs2243248 and rs2243263, IL13 rs1295686, IL18 rs243908, IL20 rs1518108, and TNFSF13B rs12428930 and rs12583006. Multivariate analysis showed that ≥6 cycles of rituximab therapy, IL18 rs243908, and the IL4 haplotype rs2243248∼rs2243263 were independently associated with HBV-RS. The IL4 haplotype rs2243248∼rs2243263 was significantly associated with HBV-RS regardless of anti-HBs status. Polymorphisms in human cytokine genes impact the risk of rituximab-associated HBV-RS. PMID:26986131

  13. Peginterferon add-on results in more HBsAg decline compared to monotherapy in HBeAg-positive chronic hepatitis B patients.

    PubMed

    Brouwer, W P; Sonneveld, M J; Xie, Q; Guo, S; Zhang, N; Zeuzem, S; Tabak, F; Zhang, Q; Simon, K; Akarca, U S; Streinu-Cercel, A; Hansen, B E; Janssen, H L A

    2016-06-01

    It is unknown whether peginterferon (PEG-IFN) add-on to entecavir (ETV) leads to more HBsAg decline compared to PEG-IFN monotherapy or combination therapy, and whether ETV therapy may prevent HBsAg increase after PEG-IFN cessation. We performed a post hoc analysis of 396 HBeAg-positive patients treated for 72 weeks with ETV + 24 weeks PEG-IFN add-on from week 24 to 48 (add-on, n = 85), 72 weeks with ETV monotherapy (n = 90), 52 weeks with PEG-IFN monotherapy (n = 111) and 52 weeks PEG-IFN + lamivudine (combination, n = 110) within 2 randomized trials. HBsAg decline was assessed at the end of PEG-IFN (EOP) and 6 months after PEG-IFN (EOF) discontinuation. Differences in baseline characteristics were accounted for using inversed probability of treatment weights. At EOP, a HBsAg reduction of ≥1log10 IU/mL was more frequently achieved for patients in the add-on or combination therapy arms (both 36%), compared to PEG-IFN mono (20%) or ETV (8%) (add-on vs PEG-IFN mono P = 0.050). At EOF, the HBsAg reduction ≥1log10 IU/mL was only sustained in patients treated with ETV consolidation (add-on vs combination and PEG-IFN mono: 40% vs 23% and 18%, P = 0.029 and P = 0.003, respectively). For add-on, combination, PEG-IFN mono and ETV, the mean HBsAg-level change at EOF was -0.84, -0.81, -0.68 and -0.33 log10 IU/mL, respectively (P > 0.05 for PEG-IFN arms). HBeAg loss at EOF was 36%, 31%, 33% and 20%, respectively (P > 0.05). PEG-IFN add-on for 24 weeks results in more on-treatment HBsAg decline than does 52 weeks of PEG-IFN monotherapy. ETV therapy may maintain the HBsAg reduction achieved with PEG-IFN.

  14. Prevalence of HBsAg and knowledge about hepatitis B in pregnancy in the Buea Health District, Cameroon: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Although infection with Hepatitis B Virus (HBV) remains a global public health problem, little is known about its epidemiology in pregnancy in sub-Saharan Africa. This study sought to determine the prevalence of, and identify factors associated with hepatitis B surface antigen (HBsAg) positivity among pregnant women in the Buea Health District (BHD) in rural Cameroon. We also assessed pregnant women’s knowledge about hepatitis B. Methods A cross-sectional, descriptive study was undertaken. Participants were evaluated using a structured questionnaire with clinical examination and were then screened for HBsAg using a commercial rapid diagnostic test. Assessment of knowledge was done using a hepatitis B basic knowledge summary score. Results Of the 176 pregnant women studied, 9.7% (95% CI: 5.7%, 15%) tested positive for HBsAg. None of the risk factors assessed was significantly associated with HBsAg positivity. The hepatitis B knowledge summary score ranged from 0 to 12 with a mean of 1.5 (SD = 3.14, median = 0, IQR = 0 to 0). Only 16% of participants had scores greater than 6/12. The knowledge summary score of the participants was associated with the educational level (p-value = 0.0037). Conclusion The high prevalence of HBsAg (9.7%) among women of child bearing age suggests that vertical transmission of HBV may be a public health problem in Buea Health District. Knowledge of HBV among pregnant women was poor. We recommend that all pregnant women ought to be routinely screened for HBV and that health education on HBV should be provided to pregnant women especially during antenatal visits. PMID:24965844

  15. Factors Predicting HBsAg Seroclearance and Alanine Transaminase Elevation in HBeAg-Negative Hepatitis B Virus-Infected Patients with Persistently Normal Liver Function

    PubMed Central

    Chien, Tai-Long; Wang, Jing-Houng; Kee, Kwong-Ming; Chen, Chien-Hung; Hung, Chao-Hung; Lu, Sheng-Nan

    2016-01-01

    Background A certain proportion of hepatitis B virus (HBV)-infected patients with persistently normal alanine transaminase (ALT) levels have significant fibrosis. Using liver stiffness measurements (Fibroscan®) and laboratory data, including serum ALT, quantitative HBsAg (qHBsAg), and HBV DNA, we attempted to predict the natural histories of these patients. Methods Non-cirrhotic HBeAg-negative chronic hepatitis B patients with persistently normal ALT were followed up prospectively with the end points of HBsAg seroclearance and ALT elevation above the upper limit of normal. The factors that were predictive of the end points were identified. Results A total of 235 patients with an average age of 48.1 +/- 10.7 years were followed up for 7 years. Eight patients (3.4%) lost HBsAg, and 15 patients (6.4%) experienced ALT elevation. The overall cumulative HBsAg seroclearances were 0.4%, 1.3% and 2.3% at years 1, 3 and 5, respectively. Regarding HBsAg seroclearance, the qHBsAg (< 30 IU/ml) cutoff resulted in a hazard ratio (HR) of 19.6 with a 95% confidence interval (CI) of 2.2–166.7 (P = 0.008). The baseline ALT level (odd ratio (OR) 1.075, 95% CI 1.020–1.132, P = 0.006) and a qHBsAg above 1000 IU/ml (3.7, 1.1–12.4, P = 0.032) were associated with ALT elevation. Limited to men, the baseline liver stiffness (1.6, 1.0–2.5, P = 0.031) and a qHBsAg above 1000 IU/ml (10.4, 2.1–52.4, P = 0.004) were factors that were independently associated with ALT elevation. Conclusion A low qHBsAg level predicted HBsAg clearance. Baseline ALT and a qHBsAg above 1000 IU/ml were independent predictive factors for ALT elevation. Among the men, the independent predictive factors for ALT elevation were qHBsAg and liver stiffness. PMID:27935953

  16. 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.

  17. 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

  18. [Retrospective evaluation of HBsAg, anti-HCV, anti-HIV and syphilis reagin antibody seropositivity in blood donors at the Trabzon Farabi Hospital].

    PubMed

    Aydin, Faruk; Cubukçu, Kivanç; Yetişkul, Serpil; Yazici, Yelda; Kaklikkaya, Neşe

    2002-01-01

    Transfusion of blood and blood products is a widely used method for therapy in medicine, however it may result with the transmission of infectious agents from donor to recipient. In order to achieve safe blood transfusions and to minimize post-transfusion infections, several screening tests for infectious agents are routinely done all around the world as well as in our country. In this study, HBsAg, anti-HCV, anti-HIV and syphilis reagin antibody tests results have been retrospectively evaluated for 33.766 blood donors during January 1, 1997 to December 31, 2000 in Blood Center of Farabi Hospital, Black Sea Technical University. Testing for HBsAg, anti-HIV and anti-HCV has been done by using commercially available micro and/or macro enzyme immunoassays, and syphilis reagin antibody test by latex agglutination (RPR) method. The indeterminate results were confirmed by retesting of sera with microparticle enzyme immunoassay and Western blot methods. As a result, in 1331 (3.94%) subjects HBsAg, in 250 (0.74%) subjects anti-HCV, and in 161 (0.47%) subjects RPR were found positive. Twenty samples which have had the results in gray-zone for anti-HIV, have been found negative with the confirmation tests.

  19. Mutation in the S gene of hepatitis B virus and anti-HBs subtype-nonspecificity contributed to the co-existence of HBsAg and anti-HBs in patients with chronic hepatitis B virus infection.

    PubMed

    Fu, Xiaochun; Chen, Jing; Chen, Huijuan; Lin, Jinpiao; Xun, Zhen; Li, Shiqi; Liu, Can; Zeng, Yongbin; Chen, Tianbin; Yang, Bin; Ou, Qishui

    2017-02-15

    The mechanism for the co-existence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in chronic HBV infected patients remains controversial. This study aimed to explore the role of HBV S gene mutation and anti-HBs subtype-nonspecificity in patients with simultaneous HBsAg/anti-HBs positivity. Chronic HBV infections with (n = 145, group I) and without (n = 141, group II) anti-HBs were included. The S gene was amplified and sequenced. The neutralization experiment was used in group I patients' sera to determine the specificity of anti-HBs. Additionally, the HBV vaccinated persons' sera were used to estimate the neutralize capacity of anti-HBs against HBsAg in group I patients. Results showed that 2.63% (145/5513) chronic HBV infected patients had positive results for anti-HBs. HBsAg amino acid (aa) substitution rate in 35 patients of group I was significantly higher than that in 58 patients of group II (1.89% vs 0.95%, P < 0.05), especially within "a" determinant (4.05% vs 1.22%, P < 0.05). In group I patients, anti-HBs in (74.29%, 26/35) patients was not directed to the subtypes of the co-existing HBsAg. Besides, some HBsAg variations in group I patients, sG145R mutation, inserted mutations, and continuous aa mutations within the major hydrophilic region (MHR), decreased the neutralized capacity of anti-HBs from HBV vaccinated persons. In conclusion, both of HBsAg mutation and anti-HBs subtype-nonspecificity contributed to the co-existence of HBsAg and anti-HBs in chronic HBV infection. HBV vaccine recipients may still have a risk of HBV infection when exposure to patients with simultaneous HBsAg/anti-HBs positivity.

  20. Role of quantitative hepatitis B surface antigen in predicting inactive carriers and HBsAg seroclearance in HBeAg-negative chronic hepatitis B patients

    PubMed Central

    Ungtrakul, Teerapat; Sriprayoon, Tassanee; Kusuman, Pattama; Chunnuan, Pitchayachuda; Soonklang, Kamonwan; Sornsamdang, Gaidganok; Auewarakul, Chirayu U.; Tanwandee, Tawesak

    2017-01-01

    Abstract To evaluate quantitative hepatitis B surface antigen (qHBsAg) as a diagnostic marker for inactive carriers (ICs) and hepatitis B surface antigen (HBsAg) seroclearance in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. We retrospectively studied 300 HBeAg-negative CHB patients with initial serum hepatitis B virus (HBV) Deoxyribonucleic acid (DNA) levels <2000 IU/mL. Serum HBV DNA and alanine aminotransferase (ALT) levels were monitored every 6 months for 24 months. ICs were identified as having persistent HBV DNA levels <2000 IU/mL and normal ALT levels, whereas active carriers (ACs) were identified as having HBV DNA levels ≥2000 IU/mL, with or without elevated ALT levels. The serum qHBsAg level was defined at baseline and evaluated as a diagnostic predictor using a receiver-operating characteristic curve. The study group comprised 134 men and 166 women with a median age of 41.5 years. At baseline, 200 ICs displayed lower levels of qHBsAg (1492 IU/mL) compared with 100 ACs (2936 IU/mL) (P = 0.005). The qHBsAg level was independently associated with the IC state and HBsAg seroclearance. Baseline qHBsAg levels <1000 IU/mL and HBV DNA levels <2000 IU/mL, when detected simultaneously, allowed for identification of ICs with 41% sensitivity and 72% specificity. Fifteen patients (5%) displayed HBsAg seroclearance after 24 months. A qHBsAg cutoff value of <50 IU/mL provided 100% sensitivity and 92% specificity in predicting HBsAg seroclearance. The qHBsAg level at a single timepoint among HBeAg-negative CHB patients with low HBV DNA levels at baseline was not a predictive marker for ICs; however, it accurately predicted spontaneous HBsAg seroclearance at 24 months. PMID:28353619

  1. Reanalyzing the visible colors of Centaurs and KBOs: what is there and what we might be missing

    NASA Astrophysics Data System (ADS)

    Peixinho, Nuno; Delsanti, Audrey; Doressoundiram, Alain

    2015-05-01

    Since the discovery of the Kuiper belt, broadband surface colors were thoroughly studied as a first approximation to the object reflectivity spectra. Visible colors (BVRI) have proven to be a reasonable proxy for real spectra, which are rather linear in this range. In contrast, near-IR colors (JHK bands) could be misleading when absorption features of ices are present in the spectra. Although the physical and chemical information provided by colors are rather limited, broadband photometry remains the best tool for establishing the bulk surface properties of Kuiper belt objects (KBOs) and Centaurs. In this work, we explore for the first time general, recurrent effects in the study of visible colors that could affect the interpretation of the scientific results: i) how a correlation could be missed or weakened as a result of the data error bars; ii) the "risk" of missing an existing trend because of low sampling, and the possibility of making quantified predictions on the sample size needed to detect a trend at a given significance level - assuming the sample is unbiased; iii) the use of partial correlations to distinguish the mutual effect of two or more (physical) parameters; and iv) the sensitivity of the "reddening line" tool to the central wavelength of the filters used. To illustrate and apply these new tools, we have compiled the visible colors and orbital parameters of about 370 objects available in the literature - assumed, by default, as unbiased samples - and carried out a traditional analysis per dynamical family. Our results show in particular how a) data error bars impose a limit on the detectable correlations regardless of sample size and that therefore, once that limit is achieved, it is important to diminish the error bars, but it is pointless to enlarge the sampling with the same or larger errors; b) almost all dynamical families still require larger samplings to ensure the detection of correlations stronger than ±0.5, that is, correlations that

  2. Graphics enhanced computer emulation for improved timing-race and fault tolerance control system analysis. [of Centaur liquid-fuel booster

    NASA Technical Reports Server (NTRS)

    Szatkowski, G. P.

    1983-01-01

    A computer simulation system has been developed for the Space Shuttle's advanced Centaur liquid fuel booster rocket, in order to conduct systems safety verification and flight operations training. This simulation utility is designed to analyze functional system behavior by integrating control avionics with mechanical and fluid elements, and is able to emulate any system operation, from simple relay logic to complex VLSI components, with wire-by-wire detail. A novel graphics data entry system offers a pseudo-wire wrap data base that can be easily updated. Visual subsystem operations can be selected and displayed in color on a six-monitor graphics processor. System timing and fault verification analyses are conducted by injecting component fault modes and min/max timing delays, and then observing system operation through a red line monitor.

  3. 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.

  4. Wind tunnel investigation of a Centaur standard shroud compartment vent from Mach number of 0.70 to 1.96

    NASA Technical Reports Server (NTRS)

    Johns, A. L.; Jones, M. L.

    1975-01-01

    An experimental investigation was conducted in the Lewis Research Center 8- by 6-foot supersonic wind tunnel to determine the vent discharge coefficient for the Centaur standard shroud/liquid hydrogen tank compartment vent. The test was conducted from Mach 0.70 to 1.96 with the vent mounted in a flat plate. Full scale simulated flight hardware, such as the vent, corrugations, aft field joint ring and ice bag clip was used. Air was discharged from a plenum chamber, located on the tunnel sidewall behind the plate, through five 6.35 cm diameter vent orifices into the free stream. Boundary layer thickeners, analytically predicted displacement thickness for the vehicle nominal flight trajectory could be simulated over the Mach number range. The highest vent discharge coefficient for any given Mach number and vent pressure ratio generally occurred at the maximum displacement thickness.

  5. Experimental measurements of the ground cloud growth during the 11 February 1974, Titan-Centaur launch at Kennedy Space Center. [(measurement of rocket exhaust from rocket launching)

    NASA Technical Reports Server (NTRS)

    Stewart, R. B.; Sentell, R. J.; Gregory, G. L.

    1976-01-01

    The Titan-Centaur was launched from Kennedy Space Center on February 11, 1974 at 0948 eastern daylight time. Ground level effluent measurements were obtained from the solid rocket motors for comparison with NASA diffusion models for predicting effluent ground level concentrations and cloud behavior. The results obtained provide a basis for an evaluation of such key model inputs such as cloud rise rate, stabilization altitude, crosswind growth, volume expansion, and cloud trajectory. Ground level effluent measurements were limited because of changing meteorological conditions, incorrect instrument location, and operational problems. Based on the measurement results, operational changes are defined. Photographs of the ground exhaust clouds are shown. The chemical composition of the exhaust gases was analyzed and is given.

  6. 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

  7. Immunization of babies born to HBsAg positive mothers: An audit on the delivery and completeness of follow up in Norfolk and Suffolk, United Kingdom.

    PubMed

    Keeble, Stuart; Quested, Jane; Barker, Deborah; Varadarajan, Abina; Shankar, Ananda Giri

    2015-01-01

    Perinatal transmission of hepatitis B infection has increased in the UK over the last decade. Routine antenatal screening of pregnant mothers (based on HBsAg) provides an effective means to identify 'at risk' babies. Follow up of babies born to infected mothers involves 4 doses of vaccination and/or a single dose of HBIG at birth. In this study we report the outcome of follow up of babies born to infected mothers over a 5 y period. One hundred sixty-three babies born to HBsAg positive mothers were followed up to ascertain the completeness for immunization and serological testing. Vaccination completion was 99.4% (162 of babies) at birth (1st dose), 95.6% (152 babies) for the second dose (at 1st month), 94.3 % (148 babies) for the 3rd dose (at 2nd month) and 83.4% (106 babies) for the 4th dose (at 12 months). Additionally, at 12 months 29.9% (38) of babies had their blood tested serologically to ascertain infection status; all babies receiving antigen testing were HBsAg negative. The overall vaccination coverage was good, although there is scope to improve the coverage of 4th dose. However, the proportion of children who were serologically tested for surface antigen at 12 months was considerably lower and there is a greater need to test babies concurrently at the time of giving the 4(th) dose. The proposed dried blood spot testing which will be rolled out from September 2014 should address this issue.

  8. 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.

  9. Universal screening for hepatitis B among pregnant women led to 96% vaccination coverage among newborns of HBsAg positive mothers in Denmark.

    PubMed

    Harder, Katja Majlund; Cowan, Susan; Eriksen, Mette Brandt; Krarup, Henrik B; Christensen, Peer Brehm

    2011-11-21

    In Denmark selective screening programs of pregnant women for hepatitis B missed 30-50% of high-risk groups and in late 2005 a universal screening of pregnant women for HBsAg was implemented. During a 2-year period a prospective enhanced surveillance of the universal screening was performed to examine the effectiveness of universal HBV-screening of pregnant women and HBV-immunizations of their newborn, and to provide a prevalence-estimate for HBV in Denmark. On a opt out basis all women in Denmark attending antenatal care were tested for hepatitis B serology. Vaccination data of the newborns and households of HBsAg positive pregnant women were assembled. Among 140,376 HBsAg tests of pregnant women, 371 (0.26%) were positive. The prevalence among women of Danish origin was 0.012% and 2.74% among foreign born women, highest for women from Southeast Asia (14.5%). Genotype C was the most prevalent (37%) and 13% had a HBVDNA ≥10(8) IU/ml. The prevalence estimate of chronic hepatitis B in Denmark was 0.2-0.3% in the general population. Among children born within the project period, 96% received vaccination at birth compared to 50% of siblings born prior to universal screening. During 3 years of passive follow-up two transmissions (0.5%) have been notified. Among children born of the positive mothers prior to the trial-period 7.3% had been notified. Thus the prevalence of HBV positive mothers has more than doubled in Denmark over the last 40 years, but among women of Danish origin it has decreased 10-fold. By replacing selective screening with universal, identification of newborns in need of HBV-immunization was increased from 50% to almost complete coverage, and also identifies mothers with high viral load for evaluation of pre-term treatment to interrupt in utero transmission.

  10. Evaluation of the automated hematology analyzer Sysmex XT-2000iV ™ compared to the ADVIA ® 2120 for its use in dogs, cats, and horses. Part II: Accuracy of leukocyte differential and reticulocyte count, impact of anticoagulant and sample aging.

    PubMed

    Bauer, Natali; Nakagawa, Julia; Dunker, Cathrin; Failing, Klaus; Moritz, Andreas

    2012-01-01

    The automated laser-based hematology analyzer Sysmex XT-2000iV™ provides a 5-part differential count and specific cytograms that are of great interest for large veterinary laboratories. The aim of the study was to validate the Sysmex XT-2000iV compared to the laser-based hematology analyzer ADVIA® 2120 and manual differential in dogs, cats, and horses as well as the impact of anticoagulant (heparin, ethylenediamine tetra-acetic acid [EDTA], and citrate) and storage at 22°C and 4°C. Consecutive fresh K(3)-EDTA blood samples from 216 cats, 314 dogs, and 174 horses were included. The impact of anticoagulant and sample storage was assessed in specimens obtained from an additional 9 cats, 10 dogs, and 10 horses. Agreement between both analyzers was excellent to good except for monocytes and canine reticulocytes. Spearman rank correlation coefficients (r (s)) between Sysmex XT-2000iV and manual differential were good to fair and ranged from 0.91 (cat lymphocytes) to 0.44 (cat monocytes). Hematocrit value (Hct), mean corpuscular hemoglobin (MCH), MCH concentration (MCHC; all: P < 0.001), and mean corpuscular volume (MCV; P < 0.01) were higher in canine citrated blood compared to heparin and EDTA. In cats, lymphocytes and monocytes were lower in heparinized blood compared to EDTA (P < 0.05), whereas in horses no significant effect was seen. Regarding storage time and temperature, white and red blood cell counts, hemoglobin, and MCH were stable. Hct, MCV, and MCHC were influenced by erythrocyte swelling. Differential count remained stable for 24 hr (22°C) and nearly 72 hr (4°C) except for monocytes. The overall performance of the Sysmex XT-2000iV was excellent and compared favorably with that of the ADVIA 2120. A special strength was the excellent detection of feline eosinophils.

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

    PubMed

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

    2013-09-13

    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(78) and Pro(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 (NH4)2SO4 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.

  12. 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.

  13. 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.

  14. 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.

  15. A new look at the visible color correlations of Centaurs and KBOs: what’s there and what we may be missing.

    NASA Astrophysics Data System (ADS)

    Peixinho, Nuno; Delsanti, Audrey; Doressoundiram, Alain

    2014-11-01

    Broadband surface colors of Centaurs and KBOs are usually seen as a mere rough approximation of their reflectivity spectra. Whereas JHK colors are not the best proxy for the near-IR spectra with possible presence of absorption features of several ices, BVRI colors have shown to be so when it comes to visible spectra. We have compiled a data-set of visible colors available in the literature for 369 objects and analyzed their color vs. color correlations and their color vs. orbital parameters correlations, both globally and by dynamical family. In this work we present the first study on: i) the “degradation” of the detectable strength of a correlation as a function of data error-bars, ii) the “risk” of missing-out existing correlations due to low sampling, iii) the sample-sizes required to “warrant” detection at a given significance level, iv) the use of partial correlations to disentangle complex mutual correlations, and v) the high sensitivity of the so-called “reddening line” to the central wavelength of similar filters at different telescopes. We will discuss, in particular: a) how data error-bars impose a limit on the detectable correlations regardless of sample size and, therefore, once that limit is achieved it is important to diminish the error-bars but pointless to enlarge the sampling with the same or larger errors; b) how almost all families still require larger samplings to “ensure” the detection of correlations stronger than +/-0.5, i.e. correlations that may “explain” ~25% or more of the color variability; and c) how it is statistically equivalent to use any of the different “flavors” of orbital excitation or collisional velocity parameters regarding the famous color-inclination correlation among Classical KBOs, whereas the inclination and Tisserand parameter relative no Neptune cannot be separated from one another.Acknowledgements: NP acknowledges funding by the Gemini-Conicyt Fund, allocated to the project #32120036.

  16. 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

  17. 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.

  18. Hepatitis B virus basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients.

    PubMed

    Yan, Chun-Hui; Zhao, Cheng-Yu; Ding, Hai; Peng, Ya-Qin; Jin, Peng-Yuan; Yan, Ling; Zhuang, Hui; Li, Tong

    2012-11-01

    The present study was aimed to obtain baseline information of basal core promoter A1762T/G1764A and precore G1896A mutations of hepatitis B virus (HBV) in 192 HBeAg-positive chronically-infected Chinese patients, who were potential candidates for antiviral treatment. The detection of these mutations (including minor mutant subpopulations) was achieved by direct sequencing, whose sensitivity for minor mutant subpopulations identification was confirmed by clone sequencing. Patients enrolled were infected with either genotype B (46.35%) or C (53.65%) HBV identified by routine tests in our laboratory. The A1762T/G1764A or G1896A mutations were detected in 125specimens (125/192, 65.10%), in which 77 (77/125, 61.60%) existed as subpopulations. The A1762T/G1764A mutations were found to be more prevalent in genotype C than that in genotype B HBV [62.14% (64/103) vs. 20.22% (18/89), P<0.0001]. There is no statistically significant link between G1896A and genotypes. The emergence of A1762T/G1764A mutations was also found to be associated with an older age, an elevated ALT/AST level, and a lower HBsAg level in serum [wild-type vs. mutant: 4.57 (3.46-5.42) vs. 3.93 (2.51-5.36), P<0.0001]. In conclusion, HBV basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients.

  19. Meeting the Centaur on the Way

    ERIC Educational Resources Information Center

    DuBois, Fletcher

    2006-01-01

    This article is an example of the use of an autobiographical curriculum theory approach which centers on the production of multiple educational lifelines across time and subject. Reactions to and questions about a late Medieval painting at the National Gallery of Art in Washington, DC are used to raise issues concerning what it means to be taught…

  20. 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.

  1. Development of lithium-thionyl chloride batteries for Centaur

    NASA Technical Reports Server (NTRS)

    Halpert, Gerald; Frank, Harvey; Lutwack, Ralph

    1988-01-01

    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.

  2. Development of lithium-thionyl chloride batteries for Centaur

    NASA Astrophysics Data System (ADS)

    Halpert, Gerald; Frank, Harvey; Lutwack, Ralph

    1987-09-01

    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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Dynamics of Centaur Chariklo and evolution of its rings

    NASA Astrophysics Data System (ADS)

    Kondratyev, B. P.

    2016-12-01

    It follows from observations that the asteroid Chariklo has two outer rings. The purpose of this paper is constructing the equilibrium model of asteroid and developing the kinetic mechanism of evolution of its rings. We have specified for Chariklo the density ρ0 ≈ 2.71 g/cm3, the mass M0 ≈ 8.817 × 10^{21} g, and the average radius R0 ≈ 128.16 km. Its rings are modeled by circular gravitating tori consisting of the small rock-ice particles that orbit the asteroid. The method does not imply the presence of hidden satellites close to the asteroid, and the equilibrium of the rings is determined by the small velocity dispersion and gravity of particles. The problem of expansion of the internal torus gravitational potential in series in powers of its geometrical parameter is solved. This enables the gravitational energy of Chariklo's rings to be found and to express their masses in terms of the mass of the asteroid M0. We calculated the mass of the inner ring to be M_{r1} ≈ 9.8 × 10^{18} g, and its relation to the mass of the asteroid is M_{r1}/M0 ≈ 0.001; similarly, for the outer ring M_{r2} ≈ 10^{18} g, and M_{r2}/M0 ≈ 0.0001. The mass ratio M_{r1}/M_{r2} ≈ 10 is typical for satellites of other asteroids and dwarf planets. The velocity dispersion of particles in rings υ1 ≈ 1 m/s and υ2 ≈ 45 cm/s is no greater than 1 div 2 % of its rotational velocity υ_{rot} ≈ 40 m/s. The particle of medium radius rp = 25 cm has the mean free path λ ≈ 7 m, and its diffusion time from center line on the surface of the torus is T'1/T_{rot1} ≈ 13 and T'2/T_{rot2} ≈ 5. The dissipation rate equation for Chariklo's rings is derived. From this equation a surprising result follows: the time of energy dissipation (the time of evolution of rings) is only T_{d1} ≈ 103 div 104 years, which by astronomical measures is a very short time scale. We adduce the arguments supporting the idea that these rings in near future can become Chariklo's satellites, and that the transformation of the rings into satellites energetically is favored.

  8. [HBsAG in feces, urine and saliva].

    PubMed

    Lento, F G; Tandurella, S

    1979-01-01

    After some observations about the tests of the research exposed in the literature, authors illustrate the tests for 142 patients divided into 5 groups: a) patients affected with acute viral hepatitis; b) patients affected with praegressa acute viral hepatitis; c) relatives of patients with acute viral hepatitis; d) volunteers; e) patients affected with chronic uraemia under dialisis periodic treatment. After the testing control, authors, conclude with an hipotesis: a possible epidemic function of faeces, urine saliva, in the passage of the acute viral hepatitis.

  9. HER-2 tissue expression correlated with serum levels in breast cancer patients.

    PubMed

    Pribylová, O; Springer, D; Vítková, I; Zima, T; Petruzelka, L

    2007-01-01

    We explored the relationship between circulating HER-2 extracellular domain and tissue HER-2 status in a group of 42 postmenopausal breast cancer patients. All patients were examined before adjuvant chemotherapy or other adjuvant treatment. Serum levels were measured by BAYER Advia Centaur System, Golden, CO (the cut-off level was in our conditions considered at 12 ng/ml). Tissue expression was assayed with the DAKO HercepTest, North America, Inc, Carpinteria, CA. Our findings that serum levels are in consonance with tissue expression could be important in metastatic breast cancer, when it is impossible to get a new tumour sample and establish the actual HER-2 status, which may be different from the primary tumour. Although we know that serum HER-2 concentration cannot be substituted for IHC or FISH, we have observed a statistically significant correlation between serum level concentration and tissue HER-2 status.

  10. 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.

  11. 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.

  12. Fatal Insulin Overdoses: Case Report and Update on Testing Methodology.

    PubMed

    Sunderland, Nick; Wong, Sophia; Lee, Carol K

    2016-01-01

    Suicidal insulin overdoses are an under-recognized and uncommon cause of death, often relying on scene and nonspecific autopsy findings. Here, we present a case report of a fatal exogenous insulin overdose in a patient with type 1 diabetes. In our case, there were no contributory autopsy findings; however, serum analog aspart insulin levels were c. 10× the predicted therapeutic upper limit (4000, reference 6.6-55 uU/mL), which correlated with scene findings. This was specifically determined by a newly developed immunocapture liquid chromatography-tandem mass spectrometry assay, able to discriminate between various synthetic insulin analogs. Total insulin levels by immunoassay were highly elevated on the Siemens Advia Centaur, but not the Roche platforms (4741 vs. 5.2 uU/mL, respectively), showing variable sensitivity of detection within the same analog depending on assay. We discuss the prevalence and features to look for at autopsy in these types of cases. Additionally, analytical options for testing insulin levels, including new methodologies, guidance on collection of samples, as well as an outline of available historical reference range data are discussed.

  13. 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.

  14. [Assessment of AFP in amniotic fluid: comparison of three automated techniques].

    PubMed

    Leguy, Marie-Clémence; Tavares, Silvina Dos Reis; Tsatsaris, Vassili; Lewin, Fanny; Clauser, Eric; Guibourdenche, Jean

    2011-01-01

    Ultrasound scanning is useful to detect neural tube defect (NTD) but scarcely distinguished between closed NTD and open NTD, which had very different prognosis. An amniotic fluid punction is thus mandatory to search for an increase in alpha foeto protein (AFP) levels and for the presence of acetylcholinesterase which identified open NTD. However, AFP levels fluctuate both with the gestational age and the assay used. Our aim was to establish normative values for AFP in amniotic fluid in the second half of pregnancy using three different immunoassays and to improve their clinical relevance. Amniotic fluid punctions were performed on 527 patients from 9 week of gestation (WG) to 37 WG either for maternal age, Trisomy 21 screening, increase in nucal translucency (control group, n = 527) or for suspicion of neural tube defect or abdominal defect (n = 5). AFP was measured using the immunoassay developed for serum AFP on the Access 2 system, the Immulite 2000 and the Advia Centaur. Results were expressed in ng/ml, multiple of the median (MoM) and percentiles. AFP decrease by 1.5 fold between 9 and 19 WG. When NTD was suspected, an increase in anmniotic AFP was observed (from 2.5 MoM to 9.3 MoM) confirming an open NTD. In conclusion, the assay developed on those 3 automates is suitable for the measurement of AFP in amniotic fluid.

  15. Evaluation of analytical performance and comparison of clinical results of the new generation method AccuTnI+3 for the measurement of cardiac troponin I using both patients and quality control plasma samples.

    PubMed

    Storti, Simona; Masotti, Silvia; Prontera, Concetta; Franzini, Maria; Buzzi, Paola; Casagranda, Ivo; Ciofini, Enrica; Zucchelli, Gian Carlo; Ndreu, Rudina; Passino, Claudio; Clerico, Aldo

    2015-12-07

    The study aims are to evaluate the analytical performance and the clinical results of the chemiluminescent Access AccuTnI+3 immunoassay for the determination of cardiac troponin I (cTnI) with DxI 800 and Access2 platforms and to compare the clinical results obtained with this method with those of three cTnI immunoassays, recently introduced in the European market. The limits of blank (LoB), detection (LoD), and quantitation (LoQ) at 20% CV and 10% CV were 4.5 ng/L and 10.9 ng/L, 17.1 and 30.4 ng/L, respectively. The results of STAT Architect high Sensitive TnI (Abbott Diagnostics), ADVIA Centaur Troponin I Ultra (Siemens Healthcare Diagnostics), ST AIA-Pack cTnI third generation (Tosoh Bioscience), and Access AccuTnI+3 (Beckman Coulter Diagnostics) showed very close correlations (R ranging from 0.901 to 0.994) in 122 samples of patients admitted to the emergency department. However, on average there was a difference up to 2.4-fold between the method measuring the highest (ADVIA method) and lowest cTnI values (AccuTnI+3 method). The consensus mean values between methods ranged from 6.2% to 29.6% in 18 quality control samples distributed in an external quality control study (cTnI concentrations ranging from 29.3 ng/L to 1557.5 ng/L). In conclusion, the results of our analytical evaluation concerning the AccuTnI+3 method, using the DxI platform, are well in agreement with those suggested by the manufacturer as well as those reported by some recent studies using the Access2 platform. Our results confirm that the AccuTnI+3 method for the Access2 and DxI 800 platforms is a clinically usable method for cTnI measurement.

  16. Environmental Impact Statement: Construction and Operation of Titan IV/Centaur Launch Complex, Vandenberg Air Force Base, California. Volume 3

    DTIC Science & Technology

    1990-08-01

    water resources would be affected by ground water withdrawal for direct project construction and operations needs and for domestic use by project...construction and operations personnel and their families. Increases in withdrawal from S-40 activities would not measurably affect local and regional air...However, the caliche plant fossils on San Miguel Island may be affected by the shock from launch-induced sonic booms, regardless of the chosen alternative

  17. 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.

  18. P/2010 TO20 LINEAR-Grauer: A comet in transition from Centaurs to the Jupiter family

    NASA Astrophysics Data System (ADS)

    Emel'yanenko, V. V.; Emel'yanenko, N. Yu.; Naroenkov, S. A.; Andreev, M. V.

    2013-05-01

    The object P/2010 TO20 LINEAR-Grauer, discovered at a heliocentric distance of over 5 AU, and at first classified as a Trojan, is now believed to be a comet. This paper reports special observations of the object that have allowed a significant refinement of its orbit and investigation of its dynamic evolution. It is shown that P/2010 TO20 LINEAR-Grauer is not a Trojan yet demonstrates unusual dynamic features. In particular, the object moves in a temporary satellite orbit relative to Jupiter over the observation interval. The comet has been in the Hill sphere for about two years and has made one revolution around the planet. The jovicentric distance function has two minima, and the smallest distance is 0.075 AU. Our estimates show that, with a probability of 0.76, the comet is likely to move in a Jupiter family orbit with a perihelion distance of less than 2.5 AU. The average time for such a transition is around forty thousand years.

  19. Effects of Prophylactic and Therapeutic Paracetamol Treatment during Vaccination on Hepatitis B Antibody Levels in Adults: Two Open-Label, Randomized Controlled Trials

    PubMed Central

    Doedée, Anne M. C. M.; Boland, Greet J.; Pennings, Jeroen L. A.; de Klerk, Arja; Berbers, Guy A. M.; van der Klis, Fiona R. M.; de Melker, Hester E.; van Loveren, Henk; Janssen, Riny

    2014-01-01

    Worldwide, paracetamol is administered as a remedy for complaints that occur after vaccination. Recently published results indicate that paracetamol inhibits the vaccination response in infants when given prior to vaccination. The goal of this study was to establish whether paracetamol exerts similar effects in young adults. In addition, the effect of timing of paracetamol intake was investigated. In two randomized, controlled, open-label studies 496 healthy young adults were randomly assigned to three groups. The study groups received paracetamol for 24 hours starting at the time of (prophylactic use) - or 6 hours after (therapeutic use) the primary (0 month) and first booster (1 month) hepatitis B vaccination. The control group received no paracetamol. None of the participants used paracetamol around the second booster (6 months) vaccination. Anti-HBs levels were measured prior to and one month after the second booster vaccination on ADVIA Centaur XP. One month after the second booster vaccination, the anti-HBs level in the prophylactic paracetamol group was significantly lower (p = 0.048) than the level in the control group (4257 mIU/mL vs. 5768 mIU/mL). The anti-HBs level in the therapeutic paracetamol group (4958 mIU/mL) was not different (p = 0.34) from the level in the control group. Only prophylactic paracetamol treatment, and not therapeutic treatment, during vaccination has a negative influence on the antibody concentration after hepatitis B vaccination in adults. These findings prompt to consider therapeutic instead of prophylactic treatment to ensure maximal vaccination efficacy and retain the possibility to treat pain and fever after vaccination. Trial Registration Controlled-Trials.com ISRCTN03576945 PMID:24897504

  20. Multicenter Comparison of Seven 25OH Vitamin D Automated Immunoassays

    PubMed Central

    Lippi, Giuseppe; Salvagno, Gian Luca; Fortunato, Antonio; Dipalo, Mariella; Aloe, Rosalia; Da Rin, Giorgio; Giavarina, Davide

    2015-01-01

    Summary Background The measurement of 25OH vitamin D continues to grow in clinical laboratories. The aim of this multi-center study was to compare the results of seven automated commercial immunoassays with a reference HPLC technique. Methods One hundred and twenty consecutive outpatient serum samples were centrifuged, divided in aliquots, frozen and shipped to the participating laboratories. 25OH Vitamin D was measured with a reference HPLC system and with seven automated commercial immunoassays (Roche Cobas E601, Beckman Coulter Unicel DXI 800, Ortho Vitros ES, DiaSorin Liaison, Siemens Advia Centaur, Abbott Architect i System and IDS iSYS). Results Compared to the reference method, the regression coefficients ranged from 0.923 to 0.961 (all p<0.001). The slope of Deming fit ranged from 0.95 to 1.06, whereas the intercept was comprised between −15.2 and 9.2 nmol/L. The bias from the reference HPLC technique varied from −14.5 to 8.7 nmol/L. The minimum performance goal for bias was slightly exceeded by only one immunoassay. The agreement between HPLC and the different immunoassays at 50 nmol/L 25OH Vitamin D varied between 0.61 and 0.85 (all p<0.001). The percentage of samples below this cut-off was significantly different with only one immunoassay. Conclusions The excellent correlation with the reference HPLC technique attests that all seven automated immunoassays may be reliably used for routine assessment of 25OH-D in clinical laboratories. The significant bias among the different methods seems mostly attributable to the lack of standardization and calls for additional efforts for improving harmonization of 25OH-D immunoassays. PMID:28356846

  1. 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.

  2. 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.

  3. 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.

  4. Vaccine Self-Assembling Immune Matrix Is a New Delivery Platform That Enhances Immune Responses to Recombinant HBsAg in Mice

    PubMed Central

    Grenfell, Rafaella F. Q.; Shollenberger, Lisa M.; Samli, E. Farah

    2015-01-01

    Vaccination remains the most effective public health tool to prevent infectious diseases. Many vaccines are marginally effective and need enhancement for immunocompromised, elderly, and very young populations. To enhance immunogenicity, we exploited the biphasic property of the (RADA)4 synthetic oligopeptide to create VacSIM (vaccine self-assembling immune matrix), a new delivery method. VacSIM solution can easily be mixed with antigens, organisms, and adjuvants for injection. Postinjection, the peptides self-assemble into hydrated nanofiber gel matrices, forming a depot with antigens and adjuvants in the aqueous phase. We believe the depot provides slow release of immunogens, leading to increased activation of antigen-presenting cells that then drive enhanced immunogenicity. Using recombinant hepatitis B virus surface antigen (rHBsAg) as a model immunogen, we compared VacSIM delivery to delivery in alum or complete Freund's adjuvant (CFA). Delivery of the rHBsAg antigen to mice via VacSIM without adjuvant elicited higher specific IgG responses than when rHBsAg was delivered in alum or CFA. Evaluating IgG subtypes showed a mixed Th1/Th2 type response following immunization with VacSIM, which was driven further toward Th1 with addition of CpG as the adjuvant. Increased specific IgG endpoint titers were observed in both C57BL/6 and BALB/c mice, representative of Th1 and Th2 environments, respectively. Restimulation of splenocytes suggests that VacSIM does not cause an immediate proinflammatory response in the host. Overall, these results suggest that VacSIM, as a new delivery method, has the potential to enhance immunogenicity and efficacy of numerous vaccines. PMID:25609075

  5. 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

  6. Acute hepatitis B virus infection with simultaneous high HBsAg and high anti-HBs signals in a previously HBV vaccinated HIV-1 positive patient.

    PubMed

    van Dommelen, Laura; Verbon, Annelies; van Doorn, H Rogier; Goossens, Valère J

    2010-03-01

    We present a case of a clinical manifest hepatitis B virus infection and a potentially misleading HBV serological profile in an HIV-1 positive patient despite previous HBV vaccination. The patient presented with an acute hepatitis B and there was no indication of chronic HBV infection or the presence of a mutation in the 'a' determinant. Remarkably, simultaneously with high HBV surface antigen and HBV viral load, high anti-HBs antibodies were present. If, due to previous HBV vaccination only anti-HBs was tested in this patient, the result of the high anti-HBs antibodies could be very misleading and offering a false sense of security. Our findings contribute to the ongoing discussion on how to assess HBV specific immunological memory and determining the role of HBV booster vaccinations in immunocompromised individuals.

  7. 77 FR 60704 - Medical Devices; Availability of Safety and Effectiveness Summaries for Premarket Approval...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... (with the adjunctive Zenith Alignment Stent). P110029, FDA-2012-M-0372 Abbot Laboratories... ARCHITECT HBsAg April 12, 2012. Qualitative, ARCHITECT HBsAg Qualitative Confirmatory, ARCHITECT HBsAg Qualitative Confirmatory Manual Diluent, ARCHITECT HBsAg Qualitative Calibrators, and ARCHITECT...

  8. 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

    2008-11-05

    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.

  9. Investigation of TC-1 flight failure using power spectral analysis

    NASA Technical Reports Server (NTRS)

    Lorenzo, C. F.

    1976-01-01

    During the Titan Centaur 1 test flight a failure involving at least one of the Centaur propellant boost pumps occurred. Also, neither of the boost pump speed instruments indicated pump rotation. Accelerometer data from the Titan Centaur 1 flight failure were analyzed using power spectral density methods to determine boost pump speed during attempted starts of the Centaur. The technique was demonstrated on a reference flight. The hydrogen boost pump speed transient was determined for the TC-1 flight. Other trends are seen in the data. However, these are not believed to be the oxygen boost pump. Discussion of data enhancement techniques is also presented.

  10. Small Bodies Exploration in the Next 35 Years

    NASA Astrophysics Data System (ADS)

    Swindle, T. D.; Chabot, N.; Barbee, B.; Bauer, J.; Bierhaus, B.; Britt, D.; Castillo-Rogez, J.; Chodas, P.; Feaga, L.; Hartzell, C.; Mercer, C.; Stickle, A.

    2017-02-01

    Small bodies (asteroids, comets, KBOs, centaurs, martian moons, meteorites, etc.) are important for science, planetary defense, and human exploration. Possibilities for the next 35 years are considered.

  11. Roentgen Satellite (ROSAT)

    NASA Technical Reports Server (NTRS)

    1986-01-01

    As result of the Challenger accident, the alternative possibility for launch of the ROSAT mission with an Atlas/Centaur launch vehicle is being considered. An overview of the problems involved in having the ROSAT flight ready for either a Shuttle or Atlas/Centaur launch is presented.

  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. 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.

  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. 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.

  16. 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.

  17. On-Orbit Propellant Motion Resulting from an Impulsive Acceleration

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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 cargo bay. Although the shuttle/Centaur development activity has been suspended, the numerical modeling techniques are available to predict on-orbit liquid motion resulting from impulsive accelerations for other missions and spacecraft.

  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.

    1986-01-01

    In-space docking and separation maneuvers of spacecraft that have large fluid mass fractions may cause undersirable 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 surface antigen vector delivers protective cytotoxic T-lymphocyte responses to disease-relevant foreign epitopes.

    PubMed

    Woo, Wai-Ping; Doan, Tracy; Herd, Karen A; Netter, Hans-Jürgen; Tindle, Robert W

    2006-04-01

    Although hepatitis B surface antigen (HBsAg) per se is highly immunogenic, its use as a vector for the delivery of foreign cytotoxic T-lymphocyte (CTL) epitopes has met with little success because of constraints on HBsAg stability and secretion imposed by the insertion of foreign sequence into critical hydrophobic/amphipathic regions. Using a strategy entailing deletion of DNA encoding HBsAg-specific CTL epitopes and replacement with DNA encoding foreign CTL epitopes, we have derived chimeric HBsAg DNA immunogens which elicited effector and memory CTL responses in vitro, and pathogen- and tumor-protective responses in vivo, when the chimeric HBsAg DNAs were used to immunize mice. We further show that HBsAg DNA recombinant for both respiratory syncytial virus and human papillomavirus CTL epitopes elicited simultaneous responses to both pathogens. These data demonstrate the efficacy of HBsAg DNA as a vector for the delivery of disease-relevant protective CTL responses. They also suggest the applicability of the approach of deriving chimeric HBsAg DNA immunogens simultaneously encoding protective CTL epitopes for multiple diseases. The DNAs we tested formed chimeric HBsAg virus-like particles (VLPs). Thus, our results have implications for the development of vaccination strategies using either chimeric HBsAg DNA or VLP vaccines. HBsAg is the globally administered vaccine for hepatitis B virus infection, inviting its usage as a vector for the delivery of immunogens from other diseases.

  20. Development of a Highly Sensitive Bioluminescent Enzyme Immunoassay for Hepatitis B Virus Surface Antigen Capable of Detecting Divergent Mutants

    PubMed Central

    Takehara, Shizuka; Takahashi, Masaharu

    2013-01-01

    Hepatitis B virus (HBV) infections are sometimes overlooked when using commercial kits to measure hepatitis B virus surface antigen (HBsAg) due to their low sensitivities and reactivities to mutant strains of various genotypes. We developed an ultrasensitive bioluminescent enzyme immunoassay (BLEIA) for HBsAg using firefly luciferase, which is adaptable to a variety of HBsAg mutants, by combining four monoclonal antibodies with a polyclonal antibody against HBsAg. The measurement of seroconversion panels showed trace amounts of HBsAg during the early infection phase by the BLEIA because of its high sensitivity of 5 mIU/ml. The BLEIA detected HBsAg as early as did PCR in five of seven series and from 2.1 to 9.4 days earlier than commercial immunoassay methods. During the late infection phase, the BLEIA successfully detected HBsAg even 40 days after the disappearance of HBV DNA and the emergence of antibodies against HBsAg. The HBsAg BLEIA successfully detected all 13 recombinant HBsAg and 45 types of HBsAg mutants with various mutations within amino acids 90 to 164 in the S gene product. Some specimens had higher values determined by the BLEIA than those by a commercial chemiluminescent immunoassay; this suggests that such discrepancies were caused by the dissociation of preS1/preS2 peptides from the particle surface. With its highly sensitive detection of low-titer HBsAg, including various mutants, the HBsAg BLEIA is considered to be useful for the early diagnosis and prevention of HBV infection because of the shorter window of infection prior to detection, which facilitates early prediction of recurrence in HBV-infected individuals. PMID:23761660

  1. Kinetics of Hepatitis B Surface Antigen Level in Chronic Hepatitis B Patients who Achieved Hepatitis B Surface Antigen Loss during Pegylated Interferon Alpha-2a Treatment

    PubMed Central

    Li, Ming-Hui; Zhang, Lu; Qu, Xiao-Jing; Lu, Yao; Shen, Ge; Wu, Shu-Ling; Chang, Min; Liu, Ru-Yu; Hu, Lei-Ping; Li, Zhen-Zhen; Hua, Wen-Hao; Song, Shu-Jing; Xie, Yao

    2017-01-01

    Background: Hepatitis B surface antigen (HBsAg) loss/seroconversion is considered to be the ideal endpoint of antiviral therapy and the ultimate treatment goal in chronic hepatitis B (CHB). This study aimed to assess the patterns of HBsAg kinetics in CHB patients who achieved HBsAg loss during the treatment of pegylated interferon (PEG-IFN) α-2a. Methods: A total of 150 patients were enrolled, composing of 83 hepatitis B envelope antigen (HBeAg)-positive and 67 HBeAg-negative patients. Patients were treated with PEG-IFN α-2a180 μg/week until HBsAg loss/seroconversion was achieved, which occurred within 96 weeks. Serum hepatitis B virus deoxyribonucleic acid and serological indicators (HBsAg, anti-HBs, HBeAg, and anti-HBe) were determined before and every 3 months during PEG-IFN α-2a treatment. Biochemical markers and peripheral blood neutrophil and platelet counts were tested every 1–3 months. Results: Baseline HBsAg levels were 2.5 ± 1.3 log IU/ml, and decreased rapidly at 12 and 24 weeks by 48.3% and 88.3%, respectively. The mean time to HBsAg loss was 54.2 ± 30.4 weeks, though most patients needed extended treatment and 30.0% of HBsAg loss occurred during 72–96 weeks. Baseline HBsAg levels were significantly higher in HBeAg-positive patients (2.9 ± 1.1 log IU/ml) compared with HBeAg-negative patients (2.0 ± 1.3 log IU/ml; t = 4.733, P < 0.001), but the HBsAg kinetics were similar. Patients who achieved HBsAg loss within 48 weeks had significantly lower baseline HBsAg levels and had more rapid decline of HBsAg at 12 weeks compared to patients who needed extended treatment to achieve HBsAg loss. Conclusions: Patients with lower baseline HBsAg levels and more rapid decline during early treatment with PEG-IFN are more likely to achieve HBsAg loss during 96 weeks of treatment, and extended therapy longer than 48 weeks may be required to achieve HBsAg loss. PMID:28229987

  2. Changes of hematological references depends on storage period and temperature conditions in rats and dogs

    PubMed Central

    Lee, Jung-Min

    2016-01-01

    Because changes in rat and dog hematological parameters according to storage conditions have been poorly documented, we sought to examine such changes. Blood analysis was performed using two hematology analyzers (ADVIA 2120i and Sysmex XN-V) after storage at room temperature and in cold storage for 5, 24, and 48 h, respectively. Interassay coefficients of variation for hematological parameters analyzed with the ADVIA 2120i and the XN-V showed similar. The levels of hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelet (PLT) showed significant variations with time in blood samples of rats and dogs. The leukocyte subpopulation showed high variation with storage conditions. The data for leukocyte differential counts obtained using the ADVIA 2120i, XN-V, and a manual differential counting procedure showed good agreement for neutrophils and lymphocyte counts, but monocytes, eosinophils, and basophils showed differences between the procedures. In conclusions, most rat and dog hematological parameters showed minimal changes; however, some showed high variation with storage time and temperature, especially PLT and leukocyte subpopulations. In conclusion, when performing hematological analysis in dogs and rats, it will be exactitude to analyze blood samples in fresh condition and at least within 24 h in the cold storage. PMID:28053618

  3. 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.

  4. 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.

  5. 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.

  6. The role of flight experiments in the development of cryogenic fluid management technologies

    NASA Astrophysics Data System (ADS)

    Chato, David J.

    2006-02-01

    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 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.

  7. 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.

  8. 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.

  9. 76 FR 60080 - Notice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... Apple Inc. of CA. The complainant, proposed respondents, other interested parties, and members of the... behalf of VIA Technologies Inc., IP-First, LLC and Centaur Technology on September 22, 2011....

  10. 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

  11. 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.

  12. Prevalence of hepatitis B virus infection in pregnant Turkish women and their families.

    PubMed

    Kuru, U; Turan, O; Kuru, N; Saglam, Z; Ceylan, Y; Nurluoglu, M; Agacfidan, A

    1996-03-01

    A total of 5,366 pregnant Turkish women were screened for hepatitis B surface antigen (HBsAg) and 225 (4.2%) of them were found to be positive. Hepatitis B e antigen (HBeAg) was detected in 6.2% of HBsAg-positive pregnant women. the overall prevalence of HBsAg and antibody to HBsAg (anti-HBs) among the spouses, previous children, mothers and first degree relatives of the HBsAg-positive pregnant women was 56%, 49%, 79% and 74% respectively. The prevalence of HBsAg is thus high in pregnant Turkish women with familial clustering of hepatitis B virus infection.

  13. 42 CFR 493.927 - General immunology.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Hepatitis markers (HBsAg, anti-HBc, HBeAg) IgA IgG IgE IgM Infectious mononucleosis Rheumatoid factor... nonreactive. Complement C3 Target value ±3 SD. Complement C4 Target value ±3 SD. Hepatitis (HBsAg,...

  14. 42 CFR 493.927 - General immunology.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Hepatitis markers (HBsAg, anti-HBc, HBeAg) IgA IgG IgE IgM Infectious mononucleosis Rheumatoid factor... nonreactive. Complement C3 Target value ±3 SD. Complement C4 Target value ±3 SD. Hepatitis (HBsAg,...

  15. 42 CFR 493.927 - General immunology.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Hepatitis markers (HBsAg, anti-HBc, HBeAg) IgA IgG IgE IgM Infectious mononucleosis Rheumatoid factor... nonreactive. Complement C3 Target value ±3 SD. Complement C4 Target value ±3 SD. Hepatitis (HBsAg,...

  16. 42 CFR 493.927 - General immunology.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Hepatitis markers (HBsAg, anti-HBc, HBeAg) IgA IgG IgE IgM Infectious mononucleosis Rheumatoid factor... nonreactive. Complement C3 Target value ±3 SD. Complement C4 Target value ±3 SD. Hepatitis (HBsAg,...

  17. 42 CFR 493.927 - General immunology.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Hepatitis markers (HBsAg, anti-HBc, HBeAg) IgA IgG IgE IgM Infectious mononucleosis Rheumatoid factor... nonreactive. Complement C3 Target value ±3 SD. Complement C4 Target value ±3 SD. Hepatitis (HBsAg,...

  18. [Quantification of the hepatitis B surface antigen in the characterization and follow-up].

    PubMed

    Rodríguez, Manuel; González-Diéguez, María Luisa

    2014-07-01

    The recent availability of commercial techniques for the quantification of the hepatitis B surface antigen (HBsAg) has revived interest in this antigen. In recent years, the antigen's potential as a biomarker of the natural history of the disease and its response to antiviral treatment has been assessed. HBsAg serum values reflect the transcriptional activity of cccDNA; reading these values could therefore complement the reading of hepatitis B virus (HBV) DNA in the categorization of the various phases of chronic HBV infection. During its natural history, HBsAg values progressively decrease from the immune-tolerant phase to the inactive carrier phase. For patients who are HBeAg-negative, the combined reading of HBV DNA and HBsAg can be useful for differentiating inactive carriers from patients with chronic HBeAg-negative hepatitis, for stratifying the risk of developing hepatocarcinoma and for predicting HBsAg clearance.

  19. Early hepatitis B surface antigen decline predicts treatment response to entecavir in patients with chronic hepatitis B

    PubMed Central

    Peng, Cheng-Yuan; Lai, Hsueh-Chou; Su, Wen-Pang; Lin, Chia-Hsin; Chuang, Po-Heng; Chen, Sheng-Hung; Chen, Ching-Hsiang

    2017-01-01

    Early declines in serum hepatitis B surface (HBsAg) levels, their optimal cutoffs, and association with therapeutic endpoints in chronic hepatitis B (CHB) patients receiving entecavir treatment remain unclear. We prospectively enrolled 529 patients (195 hepatitis B e antigen [HBeAg]-positive and 334 HBeAg-negative) with a median treatment duration of 49.2 months. Median HBsAg levels declined significantly in both groups at Month 3, but only at Months 6–12 in the HBeAg-negative group. Both groups exhibited a significant HBsAg decline with each successive year of treatment. An HBsAg decline of ≥75% from baseline, assessed at Months 3 and 12 of treatment in the HBeAg-positive and -negative patients, respectively, independently predicted a virological response and HBeAg seroconversion in the HBeAg-positive patients, an HBsAg level of <100 IU/mL in the HBeAg-negative patients, and HBsAg loss in all the patients during treatment. HBsAg levels of <3,000 IU/mL at baseline combined with an HBsAg decline of ≥75% from baseline provided a predictive algorithm for HBsAg loss (positive and negative predictive values: 70% and 100%, respectively) during 5 years of treatment. The proposed cutoffs for defining an HBsAg decline may assist clinicians in early assessments of treatment responses in genotype B-infected or C-infected CHB patients receiving entecavir therapy. PMID:28220833

  20. ON THE MASS AND ORIGIN OF CHARIKLO’S RINGS

    SciTech Connect

    Pan, Margaret; Wu, Yanqin

    2016-04-10

    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 10{sup 16} g and a typical particle size of a few meters. These values imply a collisional spreading time of ∼10{sup 5} 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 N{sub 2} 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.

  1. 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.

  2. A Uranian Trojan and the Frequency of Temporary Giant-Planet Co-Orbitals

    NASA Astrophysics Data System (ADS)

    Alexandersen, Mike; Gladman, Brett; Greenstreet, Sarah; Kavelaars, J. J.; Petit, Jean-Marc; Gwyn, Stephen

    2013-08-01

    Trojan objects share a planet’s orbit, never straying far from the triangular Lagrangian points, 60° ahead of (L4) or behind (L5) the planet. We report the detection of a Uranian Trojan; in our numerical integrations, 2011 QF99 oscillates around the Uranian L4 Lagrange point for >70,000 years and remains co-orbital for ∼1 million years before becoming a Centaur. We constructed a Centaur model, supplied from the transneptunian region, to estimate temporary co-orbital capture frequency and duration (to a factor of 2 accuracy), finding that at any time 0.4 and 2.8% of the population will be Uranian and Neptunian co-orbitals, respectively. The co-orbital fraction (∼2.4%) among Centaurs in the International Astronomical Union Minor Planet Centre database is thus as expected under transneptunian supply.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. Production of hepatitis B surface antigen in transgenic plants for oral immunization.

    PubMed

    Richter, L J; Thanavala, Y; Arntzen, C J; Mason, H S

    2000-11-01

    Here we present data showing oral immunogenicity of recombinant hepatitis B surface antigen (HBsAg) in preclinical animal trials. Mice fed transgenic HBsAg potato tubers showed a primary immune response (increases in HBsAg-specific serum antibody) that could be greatly boosted by intraperitoneal delivery of a single subimmunogenic dose of commercial HBsAg vaccine, indicating that plants expressing HBsAg in edible tissues may be a new means for oral hepatitis B immunization. However, attainment of such a goal will require higher HBsAg expression than was observed for the potatoes used in this study. We conducted a systematic analysis of factors influencing the accumulation of HBsAg in transgenic potato, including 5' and 3' flanking elements and protein targeting within plant cells. The most striking improvements resulted from (1) alternative polyadenylation signals, and (2) fusion proteins containing targeting signals designed to enhance integration or retention of HBsAg in the endoplasmic reticulum (ER) of plant cells.

  8. 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

  9. 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.

  10. SO{sub 2} oxidation in a periodically operated trickle bed: Comparison of activated carbon catalysts

    SciTech Connect

    Lee, Joong Kee; Hudgins, R.R.; Silveston, P.L.

    1996-12-31

    Catalytic activities of two different activated carbons, BPL{trademark} and Centaur{trademark} catalysts (Calgon Carbon Corp.), were compared in a periodically operated trickle-bed reactor for SO{sub 2} oxidation by varying the cycle period and split. In an effort to characterize the carbon surface, differential thermogravimetric analysis and TPD were used to observe oxygen functional groups. The Centaur catalyst, which appears to have a more suitable density of oxygen functional groups, has the higher catalytic activity for SO{sub 2} oxidation. 8 refs., 8 figs., 1 tab.

  11. 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.

  12. DFVLR Roentgen satellite

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The entire engineering model is being concluded in the shuttle configuration. The flight model components are extensively included in the shuttle configuration and will not be changed until after a binding Atlas/Centaur (A/C) booster decision for the A/C configuration. The urgent projects for the altering of the shuttle configuration on the A/C configuration must be carried out before a binding Atlas/Centaur booster decision is completed. All other modification projects are being delayed until the presentation of a binding booster decision.

  13. Cryogenic storage technology readiness for First Lunar Outpost

    NASA Astrophysics Data System (ADS)

    Schuster, John R.

    The topics are presented in viewgraph form and include the following: an assessment of cryogenic storage technology; cryogenic boiloff predictions; Space Shuttle/Centaur thermodynamic vent system; zero-g thermodynamic vent system; heat exchanger/mixer pump module; the thick multilayer insulation (MLI) development program; blanket geometry concept evaluations; four-inch thick MLI system on 1/4-scale test tank; combined environments of vibration, acceleration, and temperature testing (CEVAT); Centaur fixed foam insulation; insulation system design; and fixed foam on operational Atlas 2.

  14. Extension of MINOTAUR to higher-order spatial functions

    SciTech Connect

    Pevey, R.E.

    1999-09-01

    MINOTAUR, a generalized multidimensional geometry discrete ordinates kernel that can be used to calculate the particle flow through a complicated geometrical arrangement of materials, has been extended to use higher-order within-node spatial flux expansions. MINOTAUR is an improved version of the CENTAUR code, which was developed at the Savannah River Site by DeHart, Pevey, and Parish for flat intranode flux distributions. CENTAUR was later extended to linear spatial flux shapes by Grove and Pevey. Both of these codes were limited to two-dimensional generalized geometries, for which the regions are bounded by arbitrarily oriented line segments.

  15. 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.

  16. Cryogenic storage technology readiness for First Lunar Outpost

    NASA Technical Reports Server (NTRS)

    Schuster, John R.

    1992-01-01

    The topics are presented in viewgraph form and include the following: an assessment of cryogenic storage technology; cryogenic boiloff predictions; Space Shuttle/Centaur thermodynamic vent system; zero-g thermodynamic vent system; heat exchanger/mixer pump module; the thick multilayer insulation (MLI) development program; blanket geometry concept evaluations; four-inch thick MLI system on 1/4-scale test tank; combined environments of vibration, acceleration, and temperature testing (CEVAT); Centaur fixed foam insulation; insulation system design; and fixed foam on operational Atlas 2.

  17. Hepatitis B surface antigen in blood donors. An epidemiologic study.

    PubMed

    Jayaprakash, P A; Shanmugam, J; Hariprasad, D

    1983-01-01

    Of 8085 volunteer donors attending the blood bank at SCTIMST screened for hepatitis B surface antigen (HBsAg) carrier state by counterimmunoelectrophoresis, 103 (1.27%) were HBsAg positive. The personal data of donors showed a higher rate of HBsAg among men than women and in the age group of 21 to 30 years than in the other age groups. A significantly higher rate was noted among donors belonging to the lower socioeconomic group (p less than 0.05).

  18. Relationships between platelet counts, platelet volumes and reticulated platelets in patients with ITP: evidence for significant platelet count inaccuracies with conventional instrument methods.

    PubMed

    Diquattro, M; Gagliano, F; Calabrò, G M; Tommasi, M; Scott, C S; Mancuso, G; Palma, B; Menozzi, I

    2009-04-01

    The platelet count has a primary role in the diagnosis and treatment of idiopathic thrombocytopenic purpura (ITP). This study analysed the accuracy of ITP patient platelet counts determined by Abbott CD-Sapphire (impedance/optical) and Bayer Advia 120 (optical) analyses, compared with a reference immunoplatelet method. Instrument platelet estimates showed broad equivalence in the higher range of observed values, but significant discrepancies against the immunoplatelet count were seen when platelet counts were <10 x 10(9)/l. CD-Sapphire mean platelet volume (MPV) results revealed increased (>12 fl) platelet volumes in eight of eight ITP patients with counts of <20 x 10(9)/l compared with 6/6 and 5/13 patients with platelet counts of 20-50 and >50 x 10(9)/l. In contrast, Bayer Advia MPV values showed no relationship with the platelet count. Increased reticulated platelets were associated with an increasing CD-Sapphire MPV (R(2) = 0.61) and a decreasing platelet count. High (>40%) reticulated platelet values were seen in 9/9 patients with immunoplatelet counts of <20 x 10(9)/l compared with 0/19 patients with platelet counts above 20 x 10(9)/l. There may be a need for caution in the interpretation of platelet counts in ITP patients obtained with conventional instrument methods, and therapeutic decisions should ideally be validated by reference immunoplatelet procedures.

  19. Identification of cell morphology parameters from automatic hematology analyzers to predict the peripheral blood CD34-positive cell count after mobilization

    PubMed Central

    Shin, Saeam; Cho, Sung Ran; Kim, Sinyoung; Choi, Jong Rak; Lee, Kyung-A

    2017-01-01

    Optimal timing of apheresis initiation is important for maximizing the hematopoietic stem cell (HSC) yield. This study aimed to identify useful parameters from automatic hematology analyzers for predicting the peripheral blood CD34+ cell count after mobilization. We prospectively enrolled 53 healthy donors and 72 patients, and evaluated 43 cell morphology parameters from Unicel DxH800 (Beckman Coulter, USA) and Advia 2120i (Siemens Healthcare Diagnostics, USA). The correlation of each parameter with the CD34+ cell count in pre-apheresis blood samples was analyzed. The delta neutrophil index (DNI) from Advia 2120i, standard deviation of volume of neutrophils and monocytes (SD-V-NE and SD-V-MO), standard deviation of conductivity of neutrophils and monocytes (SD-C-NE and SD-C-MO), mean conductivity of neutrophils and monocytes (MN-C-NE and MN-C-MO), and standard deviation of axial light loss of neutrophils and monocytes (SD-AL2-NE and SD-AL2-MO) from DxH800 showed significant correlations with the CD34+ cell count. SD-V-NE, SD-C-NE, and SD-C-MO showed good or fair area under the curve values for the prediction of the CD34+ cell count. SD-V-NE, SD-C-NE, and SD-C-MO from DxH800 will provide rapid, useful information for the initiation of apheresis after mobilization. PMID:28319139

  20. [Production of marker-free plants expressing the gene of the hepatitis B virus surface antigen].

    PubMed

    Rukavtsova, E B; Gaiazova, A R; Chebotareva, E N; Bur'ianova, Ia I

    2009-08-01

    The pBM plasmid, carrying the gene of hepatitis B virus surface antigen (HBsAg) and free of any selection markers of antibiotic or herbicide resistance, was constructed for genetic transformation of plants. A method for screening transformed plant seedlings on nonselective media was developed. Enzyme immunoassay was used for selecting transgenic plants with HBsAg gene among the produced regenerants; this method provides for a high sensitivity detection of HBsAg in plant extracts. Tobacco and tomato transgenic lines synthesizing this antigen at a level of 0.01-0.05% of the total soluble protein were obtained. The achieved level of HBsAg synthesis is sufficient for preclinical trials of the produced plants as a new generation safe edible vaccine. The developed method for selecting transformants can be used for producing safe plants free of selection markers.

  1. Photocatalysis effect of nanometer TiO2 and TiO2-coated ceramic plate on Hepatitis B virus.

    PubMed

    Zan, Ling; Fa, Wenjun; Peng, Tianyou; Gong, Zhen-Kui

    2007-02-01

    The photocatalysis effect of nanometer TiO2 particles and TiO2-coated ceramic plate on Hepatitis B virus surface antigen (HBsAg) was investigated. The ELISA (enzyme-linked immunosorbent assay) standard method was used to assess the efficiency of TiO2 material to destroy the HBsAg. The research has shown that the suspension of TiO2 (0.5g/L) can destroy most of the HBsAg under the irradiation of mercury lamp, with the light intensity of 0.6mW/cm(2) at 365nm wavelength, or under the sunlight irradiation for a few hours. TiO2-coated ceramic plates can also destroy the HBsAg under the irradiation of mercury lamp, with the light intensity of 0.05mW/cm(2) at 365nm wavelength or under the room daylight for a few hours.

  2. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... infection due to hepatitis B surface antigen (HBsAg) when previously tested under § 610.40(a), (b), and (e) subsequently may donate Source Plasma for use in the preparation of Hepatitis B Immune Globulin...

  3. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... infection due to hepatitis B surface antigen (HBsAg) when previously tested under § 610.40(a), (b), and (e) subsequently may donate Source Plasma for use in the preparation of Hepatitis B Immune Globulin...

  4. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... infection due to hepatitis B surface antigen (HBsAg) when previously tested under § 610.40(a), (b), and (e) subsequently may donate Source Plasma for use in the preparation of Hepatitis B Immune Globulin...

  5. Hepatitis B Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Hepatitis B Testing Share this page: Was this page ... known as: HBV Tests; Hep B; anti-HBs; Hepatitis B Surface Antibody; HBsAg; Hepatitis B Surface Antigen; ...

  6. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... infection due to hepatitis B surface antigen (HBsAg) when previously tested under § 610.40(a), (b), and (e) subsequently may donate Source Plasma for use in the preparation of Hepatitis B Immune Globulin...

  7. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... infection due to hepatitis B surface antigen (HBsAg) when previously tested under § 610.40(a), (b), and (e) subsequently may donate Source Plasma for use in the preparation of Hepatitis B Immune Globulin...

  8. Know HBV: What Every Asian and Pacific Islander Should Know About Hepatitis B and Liver Cancer

    MedlinePlus

    ... chronic hepatitis B. For more information visit http://liver.stanford.edu » Get Vaccinated If both your HBsAg ... vaccine is so effective at preventing HBV and liver cancer that it is called “the first anti- ...

  9. [Development of cellular immunity in patients with viral hepatitis].

    PubMed

    Andonov, A; Teokharova, M; Astrukova, S; Losev, B; Mineva, E; Dragonov, P

    1976-01-01

    The development of cell-mediated immunity (CMI) to the surface antigen of hepatitis B virus (HBSAg) and Botevgrad antigen (BA) was traced in 50 hepatitis patients. Migration inhibition test (MIT) was performed with purified HBSg and AB. Blood samples from every hepatitis patient were obtained at the beginning of the icteric phase, 10 days later and during convalescence. There was correlation between the two types of viral hepatitis and the type of cellular immune response. The development of CMI is associated with disappearance of HBSAg from the serum of hepatitis patients. CMI to HBSAg develops within 9-12 days after the onset of icterus and to BA during the first two days of icterus. There is a relationship between the persistence of HBSAg and CMI.

  10. 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

  11. Role of hepatitis B virus genotype D & its mutants in occult hepatitis B infection

    PubMed Central

    Sengupta, Sonali; Panda, Subrat Kumar; Acharya, Subrat Kumar; Durgapal, Hemlata

    2013-01-01

    Background & objectives: Non-detection of hepatitis B virus (HBV) envelope protein (hepatitis B surface antigen, HBsAg) in a chronically HBV infected individual has been described as occult infection. One possible reason for this phenotype is alteration in large (L-HBsAg) to small (S-HBsAg) envelope protein ratio associated with reduced or non secretion of HBsAg. This results in quantitative levels of serum HBsAg below the detection limit of enzyme immunoassays. Genotype D of HBV has a characteristic 33 nucleotide (nt) deletion upstream of the pre-S2/S promoter. This deletion may reduce HBsAg secretion in occult infection patients infected with genotype D HBV. Additional deletions in the pre-S2/S promoter may further aggravate reduced HBsAg secretion in patients infected with genotype D HBV. Thus, the aim of the present study was to determine the role of genotype D specific 33nt deletion and additional pre-S2/S promoter deletions in causing reduced or no secretion of HBsAg, in occult infection. Since these deletions overlap virus polymerase, their effect on virus replication was also investigated. Methods: We examined the in vitro expression of HBsAg, ratio of cure and ‘e’ antigen (HBcAg/HBeAg), their secretion and virus replication, using overlength 1.3 mer/1.86 mer genotype A replicons, and genotype D replicons with and without additional pre-S2/S promoter deletions from cases of occult infection. Results: Genotype D replicon showed a decrease in HBsAg secretion compared to the wild-type genotype A. Genotype D replicons carrying additional pre-S2/S promoter deletions, showed further reduction in HBsAg secretion, demonstrated presence of intracellular HBcAg/HBeAg, virus replication intermediates and ‘e’ antigen secretion. Interpretation & conclusions: The characteristic 33 nt deletion of genotype D HBV reduces HBsAg secretion. Additional pre-S2/S promoter deletions may further diminish HBsAg secretion, leading to occult infection. Pre-S2/S promoter

  12. Hepatitis B Surface Antigen Reduction by Switching from Long-term Nucleoside/nucleotide Analog Administration to Pegylated Interferon.

    PubMed

    Tamaki, Nobuharu; Kurosaki, Masayuki; Kusakabe, Atsunori; Orito, Etsuro; Joko, Kouji; Kojima, Yuji; Kimura, Hiroyuki; Uchida, Yasushi; Hasebe, Chitomi; Asahina, Yasuhiro; Izumi, Namiki

    2017-02-15

    Hepatitis B surface antigen (HBsAg) reduction during nucleoside/nucleotide analog (NA) therapy is slow and an alternative strategy for patients receiving ongoing NA to facilitate HBsAg reduction is required. We investigated whether switching to pegylated interferon (PEG-IFN) after long-term NA administration enhances HBsAg reduction. Forty-nine patients who switched from long-term NA to 48 weeks of PEG-IFN alfa-2a were studied. The mean duration of previous NA was 48 months (sequential group). A total of 147 patients who continued NA and matched for baseline characteristics were analyzed for comparison (NA continuation group). The treatment response was defined as HBsAg reduction ≥1.0 logIU/ml at the end of PEG-IFN. HBsAg reduction at week 48 was 0.81 ± 1.1 logIU/ml in the sequential group, which was significantly higher than that in the NA continuation group (0.11 ± 0.3 logIU/ml, p <0.001). The treatment response was achieved in 29% and 2% of the sequential group and NA continuation group (p <0.001), and the odds ratio of sequential therapy for treatment response was 19 compared with NA continuation (p <0.001). In patients positive for hepatitis B e antigen (HBeAg), HBeAg seroconversion was higher in the sequential group (44% vs. 8%, p <0.001). In HBeAg negative patients, only patients in the sequential group achieved HBsAg loss. No patient needed to resume NA administration because of HBV DNA increase accompanied by alanine aminotransferase flares. In summary, sequential therapy with PEG-IFN after long-term NA enhances the reduction of HBsAg and may represent a treatment option to promote HBsAg loss. This article is protected by copyright. All rights reserved.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Distant Comets in the Early Solar System

    DTIC Science & Technology

    2000-05-23

    the small outer solar system bodies in comparison with comets in the inner solar system and in the Kuiper Belt will give us infor- mation about the...Small Satellites This is the focus of the thesis work of G. Bauer. It is thought that the origin of the Centaurs is the L(Igeworth- Kuiper Belt , the

  19. The Population of Sedna-Like Objects

    NASA Astrophysics Data System (ADS)

    Chen, Y.-T.; Kavelaars, J. J.; Gwyn, S.; Parker, A.; Suc, V.; Jordan, A.; Ip, W.-H.

    2012-05-01

    We present results of wide-field survey based on CFHTLP which searched ˜ 100 deg2 (25.1 in g’). 91 NEW TNOs and Centaurs have been discovered, one of which was identified as Sedna-like objects. We also estimate the population of Sedna-like objects.

  20. Computer controlled vent and pressurization system

    NASA Technical Reports Server (NTRS)

    Cieslewicz, E. J.

    1975-01-01

    The Centaur space launch vehicle airborne computer, which was primarily used to perform guidance, navigation, and sequencing tasks, was further used to monitor and control inflight pressurization and venting of the cryogenic propellant tanks. Computer software flexibility also provided a failure detection and correction capability necessary to adopt and operate redundant hardware techniques and enhance the overall vehicle reliability.

  1. Computer controlled vent and pressurization system. [of launch vehicle cryogenic propellant tanks

    NASA Technical Reports Server (NTRS)

    Cieslewicz, E. J.

    1975-01-01

    The paper illustrates how the Centaur space launch vehicle airborne computer, which was primarily used to perform guidance, navigation, and sequencing tasks, was further used to monitor and control inflight pressurization and venting of the cryogenic propellant tanks. Computer software flexibility also provided a failure detection and correction capability necessary to adopt and operate redundant hardware techniques and enhance the overall vehicle reliability.

  2. 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.

  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. 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.

  5. 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.

  6. Comet 29P/SW1 outburst

    NASA Astrophysics Data System (ADS)

    Trigo-Rodriguez, Josep M.

    2008-10-01

    The present outburst experienced by this Centaur (#IAUC 8978) is the brightest detected since September 2004 [for more details see Trigo-Rodriguez et al. (2008) A&A485, pp. 599-606]. In the previously reported work the outburst frequency was established in 7.3 outbursts/year, typically reaching a +13 maximum magnitude or less.

  7. 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.

  8. Quantification of hepatitis B surface antigen: a new concept for the management of chronic hepatitis B.

    PubMed

    Moucari, Rami; Marcellin, Patrick

    2011-01-01

    HBsAg is a very important clinical test that might not only indicate active hepatitis B virus (HBV) infection but might also be used to predict clinical and treatment outcome. Clearance of HBsAg in patients with chronic HBV infection is associated with a much better clinical outcome, although surveillance for early detection of hepatocellular carcinoma (HCC) should continue. HBV DNA quantification is currently used for selecting candidates for therapy, monitoring response to therapy and detecting the emergence of drug resistance. Assays for HBsAg quantification are less expensive than HBV DNA and fully automated with a high throughput capacity. HBsAg titering may be a useful tool to manage patients with chronic HBV, to more clearly define which patients may, and more importantly, may not, benefit from treatment. Baseline and on-treatment HBsAg quantification may help to refine future treatment algorithms for both immune-modulator therapy and nucleos(t)ide analogues. Both HBV markers provide complementary information on the status of HBV infection. However, the relevance of serum HBsAg levels and its use as a reliable replacement for both covalently closed circular DNA and HBV DNA remain unclear.

  9. Mechanism of inactivation of hepatitis B surface antigen by N alpha-cocoyl-L-arginine ethyl ester.

    PubMed Central

    Sugimoto, Y; Toyoshima, S

    1981-01-01

    The mechanism of N alpha-cocoyl-L-arginine ethyl ester (CAE) in the inactivation of hepatitis B surface antigen (HBsAg) was investigated. The CAE increased the density of HBsAg, and particles of the antigen were destroyed in amorphous clusters, suggesting that CAE influences the lipid components of HBsAg. The lipid components such as cholesterol and phospholipid were mostly removed from the antigen by the treatment with CAE. N alpha-Lauroyl-L-[U-14C] arginine ethyl ester (LAE), a principal component of CAE, became tightly bound to HBsAg in place of the lipid components. The binding amounts of LAE in the HBsAg-LAE complex reached 3.04 +/- 0.44 microgram/mg of protein. The formation of the complex was not influenced by the presence of CAE-related compounds such as L-arginine, L-arginine ethyl ester, and N alpha-cocoyl-L-arginine. Treatment with mercaptoethanolurea, guanidine hydrochloride, and some detergents failed to resolve appreciably the labeled LAE from the labeled complex. All attempts to reactivate the CAE-treated HBsAg and to restore it morphologically from the denatured aggregates were unsuccessful. These results indicate that CAE tightly binds to HBsAg, followed by formation of stable aggregates of the denatured HBsAg-CAE complex. Images PMID:7283411

  10. 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.

  11. 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.

  12. Pancreatitis following liver transplantation.

    PubMed

    Alexander, J A; Demetrius, A J; Gavaler, J S; Makowka, L; Starzl, T E; Van Thiel, D H

    1988-06-01

    Since 1981, when the liver transplantation program was initiated at the University of Pittsburgh, we have been impressed with the prevalence of pancreatitis occurring following liver transplantation in patients transplanted for hepatitis B-related liver disease. To either confirm this clinical impression or refute it, the records of the 27 HbsAg+ patients and those of an additional 24 HbsAg- but HbcAb and/or HbsAb+ patients who underwent orthotopic liver transplantation were reviewed to determine the prevalence of clinical pancreatitis and hyperamylasemia (biochemical pancreatitis) following liver transplantation (OLTx). Post-OLTx hyperamylasemia occurred significantly more frequently in HbsAg+ patients (6/27) than it did in the HbsAg- patients (0/24) (P less than 0.05). More importantly, clinical pancreatitis occurred in 14% (4/27) of the HbsAg+ patients and 0% (0/24) of the HbsAg- patients. Interestingly, in each case, the pancreatitis was associated with the occurrence of acute hepatitis B infection of the allograft. Based upon these data, we conclude that pancreatitis occurring after liver transplantation is more common in patients transplanted for active viral liver disease caused by hepatitis B than in those with inactive viral liver disease. These observations suggest that pancreatitis occurring in, at least some cases following liver transplantation for viral liver disease, may result from hepatitis B virus infection of the pancreas.

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

    PubMed Central

    2012-01-01

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

  14. Intra-familial spread of hepatitis B virus infection in eastern Turkey.

    PubMed

    Ucmak, H; Faruk Kokoglu, O; Celik, M; Ergun, U G O

    2007-11-01

    Hepatitis B virus (HBV) infection is a worldwide health problem. The aim of the present study was not only to determine the prevalence of HBsAg in children of HBV-infected parents but also to identify all HBSAg-positive family members to protect as many children, in the present and future, as possible. The study was carried out with the participation of 2113 family members (1205 children, 453 mothers, and 455 fathers) at Sivas SSK Hospital, Turkey. They were screened for HBV markers using standard enzyme immunoassay between September 2001 and March 2005. The prevalence of any HBV markers and HBsAg among family members of index cases was 50.5% and 30.5% respectively. HBsAg carrier rate was higher among fathers (61%) than mothers (47%), (P<0.05). The children of mother index cases had higher rates of HBsAg compared with the children of father index cases (P<0.01). Our results suggest that intra-familial childhood horizontal transmission (especially mother-to-child) is important for HBV transmission in the Turkish community, and highlights the need for screening of adult siblings and mothers of adult HBsAg carriers in addition to their spouses and children.

  15. Overview of expression of hepatitis B surface antigen in transgenic plants.

    PubMed

    Guan, Zheng-jun; Guo, Bin; Huo, Yan-lin; Guan, Zheng-ping; Wei, Ya-hui

    2010-10-28

    Hepatitis B virus (HBV), a pathogen for chronic liver infection, afflicts more than 350 million people world-wide. The effective way to control the virus is to take HBV vaccine. Hepatitis B surface antigen (HBsAg) is an effective protective antigen suitable for vaccine development. At present, "edible" vaccine based on transgenic plants is one of the most promising directions in novel types of vaccines. HBsAg production from transgenic plants has been carried out, and the transgenic plant expression systems have developed from model plants (such as tobacco, potato and tomato) to other various plant platforms. Crude or purified extracts of transformed plants have been found to conduct immunological responses and clinical trials for hepatitis B, which gave the researches of plant-based HBsAg production a big boost. The aim of this review was to summarize the recent data about plant-based HBsAg development including molecular biology of HBsAg gene, selection of expression vector, the expression of HBsAg gene in plants, as well as corresponding immunological responses in animal models or human.

  16. 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

  17. 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

  18. 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

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

    PubMed

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

    2016-07-15

    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), 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.

  20. A Study on the Age-Related Changes in Hepatitis B and C Virus Serology

    PubMed Central

    Guclu, Ertugrul; Ogutlu, Aziz; Karabay, Oguz

    2016-01-01

    Objective: There are a limited number of studies on the seroprevalence of Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infection in Turkey. This study aimed to compare HBV and HCV seroprevalence rates before and after the implementation of national hepatitis B vaccination program (NHPVP) and to explore age-related changes in the seroprevalences. Materials and Methods: Results of Hepatitis B surface antigen (HBsAg), Hepatitis B virus surface antibody (antiHBs) and anti-HCV tests performed during 2009 and 2010 in a state hospital laboratory were reviewed retrospectively. As NHPVP was started in 1998, 12 years of age and younger children were considered post- NHPVP period subjects. Results: A total of 3280 HBsAg, 2444 antiHBs and 3188 anti-HCV test results were reviewed, representing approximately 3% of the population of the city where the study was conducted. HBsAg, antiHBs and anti-HCV positivity were 3.2%, 36.12% and 0.97%, respectively. HBsAg and antiHBs positivity were higher among males (p<0.001). When assessed by age groups, HBsAg positivity was found to be the lowest in the age group 0–12 and highest in the age group 51–60. HBsAg positivity was lower in the post-NHPVP period versus pre-NHPVP period (p=0.01). Anti-HCV positivity was similar for pre- and post- NHPVP periods (p>0.05). Conclusion: Owing to the use of NHPVP, HBsAg seropositivity has decreased, and it is expected to decrease further in the next years with a wider implementation of the program. Efforts should be continued to increase the level of awareness in the community for HBV and the importance of immunization. PMID:27026763

  1. Expression of hepatitis B surface antigen in transgenic banana plants.

    PubMed

    Kumar, G B Sunil; Ganapathi, T R; Revathi, C J; Srinivas, L; Bapat, V A

    2005-10-01

    Embryogenic cells of bananan cv. Rasthali (AAB) have been transformed with the 's' gene of hepatitis B surface antigen (HBsAg) using Agrobacterium mediated transformation. Four different expression cassettes (pHBS, pHER, pEFEHBS and pEFEHER) were utilized to optimize the expression of HBsAg in banana. The transgenic nature of the plants and expression of the antigen was confirmed by PCR, Southern hybridization and reverse transcription (RT)-PCR. The expression levels of the antigen in the plants grown under in vitro conditions as well as the green house hardened plants were estimated by ELISA for all the four constructs. Maximum expression level of 38 ng/g F.W. of leaves was noted in plants transformed with pEFEHBS grown under in vitro conditions, whereas pHER transformed plants grown in the green house showed the maximum expression level of 19.92 ng/g F.W. of leaves. Higher monoclonal antibody binding of 67.87% of the antigen was observed when it was expressed with a C-terminal ER retention signal. The buoyant density in CsCl of HBsAg derived from transgenic banana leaves was determined and found to be 1.146 g/ml. HBsAg obtained from transgenic banana plants is similar to human serum derived one in buoyant density properties. The transgenic plants were grown up to maturity in the green house and the expression of HBsAg in the fruits was confirmed by RT-PCR. These transgenic plants were multiplied under in vitro using floral apex cultures. Attempts were also made to enhance the expression of HBsAg in the leaves of transgenic banana plants by wounding and/or treatment with plant growth regulators. This is the first report on the expression of HBsAg in transgenic banana fruits.

  2. Characterization of hepatitis B virus surface antigen variability and impact on HBs antigen clearance under nucleos(t)ide analogue therapy.

    PubMed

    Velay, A; Jeulin, H; Eschlimann, M; Malvé, B; Goehringer, F; Bensenane, M; Frippiat, J-P; Abraham, P; Ismail, A M; Murray, J M; Combet, C; Zoulim, F; Bronowicki, J-P; Schvoerer, E

    2016-05-01

    For hepatitis B virus (HBV)-related chronic infection under treatment by nucleos(t)ide analogues (NUCs), HBsAg clearance is the ultimate therapeutic goal but very infrequent. We investigated how HBV envelope protein variability could lead to differential HBsAg clearance on NUCs. For 12 HBV genotype D patients receiving NUCs, six resolvers (HBsAg clearance) were compared to six matched nonresolvers (HBsAg persistence). PreS/S amino acid (aa) sequences were analysed with bioinformatics to predict HBV envelope antigenicity and aa covariance. To enrich our analyses on very rare resolvers, these were compared with other HBV genotype D strains in three characterized clinical cohorts including common chronically infected patients. The sT125M+sP127T combination was observed in four nonresolvers of six, corroborated by aa covariance analysis, associated with a lower predicted antigenicity than sT125T+sP127P. Concordant features within this HBV key functional domain, at positions 125 and 127, were reported from two of the three comparative cohorts. In our hands, a lower ELISA reactivity of HBV-vaccinated mice sera was observed against the sT125M mutant. In the S gene, 56 aa changes in minor variants were detected in non-resolvers, mainly in the major hydrophilic region, vs 28 aa changes in resolvers. Molecular features in patients showing HBsAg persistence on NUCs argue in favour of a different aa pattern in the HBV S gene compared to those showing HBsAg clearance. In nonresolvers, a decrease in HBs 'a' determinant antigenicity and more frequent mutations in the S gene suggest a role for the HBV envelope characteristics in HBsAg persistence.

  3. Targeted case finding for hepatitis B using dry blood spot testing in the British-Chinese and South Asian populations of the North-East of England.

    PubMed

    McPherson, S; Valappil, M; Moses, S E; Eltringham, G; Miller, C; Baxter, K; Chan, A; Shafiq, K; Saeed, A; Qureshi, R; Hudson, M; Bassendine, M F

    2013-09-01

    Chronic infection with the hepatitis B virus (HBV) is a frequent cause of cirrhosis and liver cancer. Targeted HBV screening is recommended by the Centre for Disease Control (CDC) and Prevention for subjects born in countries with >2% HBV prevalence. However, there are no UK guidelines. Here, we applied the (CDC) recommendations to the British-Chinese and British-South Asian community of North-East (NE) England. British-Chinese and South Asian subjects were invited to attend for HBV education and screening sessions held in community centres. Hepatitis B surface antigen (HBsAg) and hepatitis B core total antibody (HBcAb) were tested with dry blood spot tests. South Asians were also tested for hepatitis C antibody (HCVAb). A total of 1126 subjects (606 Chinese and 520 South Asian) were screened. Sixty-two (5.5%) were HBsAg positive. Ten of these reported a previous diagnosis of HBV. The prevalence of HBsAg positivity was 4.6% when previously diagnosed individuals were excluded. The HBsAg prevalence was significantly higher in the Chinese subjects compared with South Asians (8.7% VS. 1.7% P < 0.001). In Chinese subjects, HBsAg positivity was highest in subjects born in Vietnam (17.4%), followed by China (11%), Hong Kong (7.8%) and the UK (6.7%). Subjects from Pakistan had the highest HBsAg and HCV Ab prevalence in the South Asians (3.1% and 1.8%, respectively). Ten percentage of HBsAg positive patients who had follow-up assessment had active disease requiring antiviral treatment. Undiagnosed HBV infection was above the 2% threshold for screening suggested by the CDC in the British-Chinese and Pakistani community of NE England, which provides evidence for a UK HBV-targeted screening programme.

  4. Seroprevalence of hepatitis B surface antigen in pregnant women attending antenatal clinic in Honiara Solomon Islands, 2015

    PubMed Central

    Getahun, Aneley; Baekalia, Margaret; Panda, Nixon; Lee, Alice; Puiahi, Elliot; Khan, Sabiha; Tahani, Donald; Manongi, Doris

    2016-01-01

    AIM To determine the seroprevalence of hepatitis B surface antigen (HBsAg) among pregnant women attending antenatal clinic in Honiara, Solomon Islands. METHODS This descriptive cross-sectional study was carried out in seven area health centers in Honiara. From March to June 2015, identification of eligible pregnant women in each site was conducted using systematic random sampling technique. A total of 243 pregnant women who gave written informed consent were enrolled. Standardized tool was used to record demographics, obstetric history and serology results. HBsAg and hepatitis B e antigen (HBeAg) were tested using point-of-care rapid diagnostic test. All HBsAg positive samples were verified using enzyme-linked immunosorbent assay. RESULTS The mean age of participants was 26 ± 6 years. The overall hepatitis HBsAg prevalence was 13.8% with higher rate (22%) reported in women between 30-34 years of age. Majority of HBsAg positive participants were Melanesians (29 out for 33). None of the pregnant women in the 15-19 years and ≥ 40 years tested positive for HBsAg. There was no statistically significant difference in HBsAg prevalence by age, ethnicity, education and residential location. The overall HBeAg seroprevalence was 36.7%. Women between 20-24 years of age had the highest rate of 54.5%. Low level of knowledge about hepatitis B vaccination was reputed. Overall, 54.6% of participants were not aware of their hepatitis B vaccination status and only 65.2% of mothers reported their child had been vaccinated. CONCLUSION Hepatitis B is a disease of public health importance in Solomon Islands and emphasize the need for integrated preventative interventions for its control. PMID:28008343

  5. 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.

  6. 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).

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

    PubMed

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

    1983-03-01

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

  8. The colors of cometary nuclei—Comparison with other primitive bodies of the Solar System and implications for their origin

    NASA Astrophysics Data System (ADS)

    Lamy, P.; Toth, I.

    2009-06-01

    We present new color results of cometary nuclei obtained with the Hubble Space Telescope (HST) whose superior resolution enables us to accurately isolate the nucleus signals from the surrounding comae. By combining with scrutinized available data obtained with ground-based telescopes, we accumulated a sample of 51 cometary nuclei, 44 ecliptic comets (ECs) and 7 nearly-isotropic comets (NICs) using the nomenclature of Levison [Levison, H.F., 1996. In: Rettig, T.W., Hahn, J.M. (Eds.), Completing the Inventory of the Solar System. In: ASP Conf. Ser., vol. 107, pp. 173-192]. We analyze color distributions and color-color correlations as well as correlations with other physical parameters. We present our compilation of colors of 232 outer Solar System objects—separately considering the different dynamical populations, classical KBOs in low and high-inclination orbits (respectively CKBO-LI and CKBO-HI), resonant KBOs (practically Plutinos), scattered-disk objects (SDOs) and Centaurs—of 12 candidate dead comets, and of 85 Trojans. We perform a systematic analysis of all color distributions, and conclude by synthesizing the implications of the dynamical evolution and of the colors for the origin of the minor bodies of the Solar System. We find that the color distributions are remarkably consistent with the scenarios of the formation of TNOs by Gomes [Gomes, R.S., 2003. Icarus 161, 404-418] generalized by the "Nice" model [Levison, H.F., Morbidelli, A., VanLaerhoven, Ch., Gomes, R., Tsiganis, L., 2008. Icarus 196, 258-273], and of the Trojans by Morbidelli et al. [Morbidelli, A., Levison, H.F., Tsiganis, K., Gomes, R., 2005. Nature 435, 462-465]. The color distributions of the Centaurs are globally similar to those of the CKBO-HI, the Plutinos and the SDOs. However the potential bimodality of their distributions allows to possibly distinguish two groups based on their (B-R) index: Centaur I with (B-R)>1.7 and Centaurs II with (B-R)<1.4. Centaurs I could be composed of

  9. 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

  10. 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

  11. Active compounds from Saussurea lappa Clarks that suppress hepatitis B virus surface antigen gene expression in human hepatoma cells.

    PubMed

    Chen, H C; Chou, C K; Lee, S D; Wang, J C; Yeh, S F

    1995-05-01

    We have examined the antiviral activity of the crude extract prepared from the root of Saussurea lappa Clarks, a Chinese medicinal herb which is widely used for many illnesses including cancer. Two active components, costunolide and dehydrocostus lactone, were identified which show strong suppressive effect on the expression of the hepatitis B surface antigen (HBsAg) in human hepatoma Hep3B cells, but have little effect on the viability of the cells. Both costunolide and dehydrocostus lactone suppress the HBsAg production by Hep3B cells in a dose-dependent manner with IC50s of 1.0 and 2.0 microM, respectively. Northern blotting analysis shows that the suppression of HBsAg gene expression by both costunolide and dehydrocostus lactone were mainly at the mRNA level. Furthermore, the suppressive effect of costunolide and dehydrocostus lactone on HBsAg and hepatitis B e antigen (HBeAg), a marker for hepatitis B viral genome replication in human liver cells, was also observed in another human hepatoma cell line HepA2 which was derived from HepG2 cells by transfecting a tandemly repeat hepatitis B virus (HBV) DNA. Similarly, the mRNA of HBsAg in HepA2 cells was also suppressed by these two compounds. Our findings suggest that costunolide and dehydrocostus lactone may have potential to develop as specific anti-HBV drugs in the future.

  12. Influence of chemical modification of N alpha-cocoyl-L-arginine ethyl ester on its hepatitis B surface antigen-inactivating effect.

    PubMed Central

    Sugimoto, Y; Toyoshima, S

    1980-01-01

    We have reported previously that N alpha-cocoyl-L-arginine ethyl ester (CAE) strongly inactivates hepatitis B surface antigen (HBsAg; Sugimoto and Toyoshima, Antimicrob. Agents Chemother. 16:329--332, 1979). Replacement of the L-arginine moiety of CAE by L-lysine did not decrease the HBsAg-inactivating effect of CAE, whereas replacement by some neutral amino acids and L-ornithine decreased it. Esterification of the carboxyl group of N alpha-acyl-L-arginine enhanced its inactivating effect. When the ethyl ester of CAE was converted to an amide group, the effect was appreciably decreased. Modification of the carboxyl group was essential for the inactivation. The effectiveness of N alpha-acyl-L-arginine ethyl ester depends upon the length of the acyl group, with the optimum length for the inactivation of HBsAg being C12 to C14. In addition to CAE, N alpha-lauroyl-L-lysine ethyl ester and N alpha-cocoyl-L-arginine amide were found to be strong inactivators of HBsAg. Significant inactivating effects on HBsAg were not observed in many anionic detergents containing an amino acid. These results suggest that for strongly inactivating HBsAg, a compound should contain a special amino acid, such as L-arginine, and a long acyl group and exhibit a cationic property. PMID:7447415

  13. Development of the CpG Adjuvant 1018: A Case Study.

    PubMed

    Campbell, John D

    2017-01-01

    The development of aluminum salts (alum) as vaccine adjuvants was an empirical process with little understanding of the mechanism of action and, with decades of use, it has become clear that there is a need for alternatives where alum-based adjuvants are suboptimal. Oligonucleotides containing unmethylated CpG sequences represent one alternative as they are potent stimulators of the vertebrate innate immune system through activation of Toll-like receptor-9. This chapter outlines the methods used by Dynavax Technologies to progress a CpG-containing oligonucleotide sequence termed 1018 through preclinical and clinical testing as an adjuvant for immunization against hepatitis B virus (HBV). 1018 is a short (22-mer) oligonucleotide sequence containing CpG motifs active in both rodents and primates. Preclinical testing of hepatitis B surface antigen (HBsAg) + 1018 in comparison to HBsAg + alum demonstrated induction of substantially higher antibody titers and a favorable safety profile for 1018. Most importantly, clinical studies with HBsAg vaccination consistently demonstrate more rapid induction of protective antibody titers with 1018 compared to alum in all populations studied, including groups that are harder to immunize such as the elderly and immunocompromised individuals. These studies represent the basis for use of the CpG-motif-containing oligonucleotide 1018 as an improved adjuvant for HBsAg immunogenicity. HBsAg + 1018 (HEPLISAV-B(™)) is currently in late-stage clinical testing for prophylactic immunization against HBV.

  14. Low prevalence of hepatitis B virus infection in patients with autoimmune diseases in a Chinese patient population.

    PubMed

    Sui, M; Wu, R; Hu, X; Zhang, H; Jiang, J; Yang, Y; Niu, J

    2014-12-01

    Hepatitis B is a very common communicable disease in China but the prevalence of hepatitis B virus (HBV) infection in patients with autoimmune diseases is unknown. We retrospectively investigated the prevalence of autoimmune diseases in patients with HBV infection. The medical records of 4060 patients with autoimmune or nonautoimmune diseases were reviewed. A positive test result for hepatitis B surface antigen (HBsAg) was used to indicate the presence of HBV infection. Autoimmune diseases included autoimmune hepatitis, primary biliary cirrhosis, systemic lupus erythematosus and ulcerative colitis. Nonautoimmune conditions included inguinal hernia, appendicitis and pregnant or postpartum women. The proportion of autoimmune disease patients who were HBsAg positive (2.24%) was significantly lower than that of nonautoimmune disease patients who were HBsAg positive (4.58%; P = 0.0014). Regarding hepatic autoimmune diseases, the positivity rates for HBsAg in autoimmune hepatitis patients (0.83%) and primary biliary cirrhosis patients (1.02%) were both significantly lower than in nonautoimmune patients (4.58%; P = 0.006 and 0.004, respectively). Patients with hepatic autoimmune disease were significantly less likely to be HBsAg positive (0.93%) than patients with non-hepatic autoimmune disease (3.99%; P = 0.002). Patients with autoimmune diseases, especially those with hepatic autoimmune disease, may more efficiently clear HBV than patients with nonautoimmune diseases.

  15. Hepatitis B virus in drug users in France: prevalence and vaccination history, ANRS-Coquelicot Survey 2011-2013.

    PubMed

    Brouard, C; Pillonel, J; Sogni, P; Chollet, A; Lazarus, J V; Pascal, X; Barin, F; Jauffret-Roustide, M

    2017-01-19

    People who use drugs (PWUD) are a key population for hepatitis B virus (HBV) vaccination and screening. We aimed to estimate the seroprevalence of HBs antigen (HBsAg) and self-reported HBV vaccination history in French PWUD attending harm reduction centres using data from the ANRS-Coquelicot multicentre survey conducted in 2011-2013 in 1718 PWUD. Self-fingerprick blood samples were collected on dried blood spots to detect the presence of HBsAg. HBsAg seroprevalence was estimated at 1·4% [95% confidence interval (CI) 0·8-2·5]. It varied between PWUD born in high (7·6%, 95% CI 2·7-19·1), moderate (2·2%, 95% CI 0·8-5·7) and low (0·7%, 95% CI 0·3-1·5) endemic zones. Factors independently associated with HBsAg carriage were being born in a moderate or high endemic zone or reporting precarious housing. Self-reported HBV vaccination history varied from 47·4% in high endemic zones, to 59·3% and 62·6% for moderate and low endemic zones, respectively. Our results suggest that drug use plays a small and substantial role, respectively, in HBsAg carriage in PWUD born in high/moderate and low endemic zones.

  16. 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.

  17. 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.

  18. Hepatitis B virus surface antigen as delivery vector can enhance Chlamydia trachomatis MOMP multi-epitope immune response in mice.

    PubMed

    Zhu, Shanli; Feng, Yan; Rao, Pinhuan; Xue, Xiangyang; Chen, Shao; Li, Wenshu; Zhu, Guanbao; Zhang, Lifang

    2014-05-01

    Chlamydia trachomatis is the leading cause of sexually transmitted infections worldwide. There is currently no commercially available vaccine against C. trachomatis. Major outer membrane protein (MOMP) of C. trachomatis is considered to be an ideal candidate for prophylactic vaccine. We designed a MOMP multi-epitope containing T- and B-cell epitope-rich peptides and developed hepatitis B surface antigen (HBsAg) as antigen delivery vehicle. In order to study the immunogenicity and efficacy of the candidate vaccine in a murine model of chlamydial genital infection, we engineered a recombinant plasmid expressing HBsAg and MOMP multi-epitope genes. Results of reverse transcription polymerase chain reaction and immunofluorescence assay revealed successful expression of the recombinant HBsAg/MOMP multi-epitope gene at both the transcription and translation levels. Intramuscular administration in mice was able to elicit not only antibodies against Chlamydia and HBsAg but also cytotoxic T lymphocyte activity against Chlamydia. In addition, mice inoculated with the rHBsAg were highly resistant to C. trachomatis genital infection. The rHBsAg DNA with MOMP multi-epitope appended at the C terminus of the HBsAg stimulated a stronger immune response and protective response than that appended at the N terminus. Together, our results suggested that use of a recombinant HBsAg encoding the MOMP multi-epitope could be a powerful approach to developing a safe and immunogenic C. trachomatis vaccine.

  19. Occult hepatitis B viral infection among blood donors in South–Eastern Nigeria

    PubMed Central

    Nna, Emmanuel; Mbamalu, Chinenye; Ekejindu, Ifeoma

    2014-01-01

    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

  20. [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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. [Pseudohypobicarbonatemia in a patient with a kappa IgA monoclonal gammapathy].

    PubMed

    Lazzouni, Ismaïl; Cornec, Emilie; Meskar, Ahmed; Lucas, Danièle; Kerspern, Hélène; Carré, Jean-Luc

    2014-01-01

    Paraprotein interferences assays are known but rather unusual in clinical chemistry.we here report a paraprotein interference with a bicarbonate assay in a IgA kappa-type myeloma patient. Serum bicarbonate level was assessed by the enzymatic method of a multiparametric chemistry analyzer (Advia 1800, Siemens) as well as a specific electrode assay on a blood gas analyzer (GEM 4000, IL). Paraprotein interference with the enzymatic assay was evidenced by an abnomally low bicarbonate level measured by the enzymatic method in contrast with usual levels obtained by using the gas analyzer and with the clinical status of the patient. Therefore, gammapathy has to be taken into consideration when interpreting biological data.

  6. Automated analysis of mature red blood cells and reticulocytes in SS and SC disease.

    PubMed

    Maier-Redelsperger, Micheline; Flahault, Antoine; Neonato, Maria Grazia; Girot, Robert; Labie, Dominique

    2004-01-01

    Phenotypic expression of sickle cell disease (SCD) is highly variable. We investigated red blood cells (RBCs) and reticulocytes using a laser light scattering method (ADVIA120, Bayer Diagnostics, Tarrytown, NY) in a series of patients with either sickle cell anemia (SS) or compound SC heterozygosity (SC), both groups with or without alpha thalassemia. Results were compared with those of a series of patients without hematological disease. Known data were consistently confirmed, namely heterogeneity in cell volume and hemoglobin (Hb) concentration, as well as the premature exit of "stress" reticulocytes from the bone marrow, mostly in SS patients. Specific changes were observed during maturation, including decreases in macrocytic and hypodense cells. Simultaneous viewing of the indices of the different RBC populations provided information on erythropoietic maturation by a rapid, reproducible, and cost-effective method.

  7. 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."

  8. Performance evaluation of the latest fully automated hematology analyzers in a large, commercial laboratory setting: a 4-way, side-by-side study.

    PubMed

    Bourner, G; Dhaliwal, J; Sumner, J

    2005-01-01

    Gamma-Dynacare is a Canadian-based community laboratory partnership formed in the mid-1990s through the merger of 3 prominent Ontario medical diagnostic laboratories. Laboratory Corporation of America acquired an interest in the GD partnership in mid 2002. We service more than 10,000 community-based Canadian clinicians, hospital partners, and private clients with an integrated customer-focused system that includes specimen collection, transportation, and results reporting services. With more than 1,700 highly qualified medical, technical, and support staff and a network of laboratories, Gamma Dynacare aims to be at the forefront of technological innovation to better service the clinician base and ultimately deliver better patient care. We were looking for a hematology analyzer that would allow. (1) standardization throughout Ontario in our 4 largest sites and (2) better performance to effectively handle aged samples and minimize slide review. To select the best, most productive hematology analyzer for our environment, it was decided to perform a side-by-side comparison of the top hematology analyzers from Abbott (Cell-Dyn 3500), Beckman Coulter (LH 750), Bayer (Advia 120), and Sysmex (XE 2100), utilizing the same samples. CBC, differential and reticulocyte parameters were all evaluated according to CLSI (formerly NCCLS) and established hematology analyzer evaluation guidelines. We assessed each analyzer for precision, linearity, carryover, stability, differential capabilities, slide review rates, and throughput (clean bench studies). Two hundred samples were assessed for differential and morphology flagging on each analyzer using the reference 400 cell manual differential for comparison. Throughput was assessed by analyzing 700 consecutive samples representative of our workload mix. Stability studies at 24 hours showed that the Beckman Coulter LH 750 was least affected by EDTA, effect with minimal changes in the mean corpuscular volume (MCV) and hematocrit. Both

  9. 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.

  10. 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.

  11. Automated Mars surface sample return mission concepts for achievement of essential scientific objectives

    NASA Technical Reports Server (NTRS)

    Weaver, W. L.; Norton, H. N.; Darnell, W. L.

    1975-01-01

    Mission concepts were investigated for automated return to Earth of a Mars surface sample adequate for detailed analyses in scientific laboratories. The minimum sample mass sufficient to meet scientific requirements was determined. Types of materials and supporting measurements for essential analyses are reported. A baseline trajectory profile was selected for its low energy requirements and relatively simple implementation, and trajectory profile design data were developed for 1979 and 1981 launch opportunities. Efficient spacecraft systems were conceived by utilizing existing technology where possible. Systems concepts emphasized the 1979 launch opportunity, and the applicability of results to other opportunities was assessed. It was shown that the baseline missions (return through Mars parking orbit) and some comparison missions (return after sample transfer in Mars orbit) can be accomplished by using a single Titan III E/Centaur as the launch vehicle. All missions investigated can be accomplished by use of Space Shuttle/Centaur vehicles.

  12. 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.

  13. 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.

  14. Occurrence of hepatitis and hepatitis B surface antigen in adult patients with acute leukemia.

    PubMed Central

    Cowan, D. H.; Kouroupis, G. M.; Leers, W. D.

    1975-01-01

    Fifty-eight adult patients with acute leukemia were screened at the onset of the disease for hepatitis B antigen (HBSAg) in the serum, and during the course of the disease for the development of hepatitis B. One patient had a positive test for HBSAg by the radioimmunoassay technique only at the time leukemia was diagnosed; this patient had received transfusions some years before. In six patients icteric hepatitis B developed; five recovered completely and one died of leukemia during the course of hepatitis. All patients in whom hepatitis developed had received transfusions as a part of supportive therapy for leukemia. The hepatitis risk for patients who received transfusions of blood found to be negative for HBSAg by counterimmunoelectrophoresis was 0.26 percent per unit of blood administered. PMID:1054615

  15. Active viral B hepatitis in parenteral drug abusers with acquired immune deficiency syndrome (AIDS).

    PubMed

    Leevy, C B; Nurse, H; Kapila, R

    1989-01-01

    Eighty-percent of 47 parenteral drug abusers with hepatomegaly and acquired immunodeficiency syndrome had HBV DNA in serum, although only 27% were HBsAg or "e" antigen-positive by polyclonal radioimmunoassay. Liver biopsies from each of 37 HBV DNA seropositive patients showed HBV DNA and were HBcAg-positive. The absence of positive HBsAg and "e" antigen in HBV DNA-positive patients was attributable to the presence of immune complexes; after in vitro dissociation of these complexes there was an increase in HBsAg from 24% to 86%, and of "e" antigen from 19% to 62%. These data indicate that actively replicating hepatitis B virus is common in patients with AIDS, and that precautions should be taken to prevent its dissemination. Therapy in these patients should address both human immunodeficiency and hepatitis B virus infections.

  16. Potential risk of salivary-mediated viral hepatitis type B transmission from oral exposure to fomites.

    PubMed

    Osterholm, M T; Max, B J; Hanson, M; Polesky, H F

    1979-12-01

    Twelve grade school and junior high school students had oral exposures to hepatitis B surface antigen (HBsAg) positive saliva via contact with contaminated musical instruments. The 12 exposed students and 18 students who served as age and sex matched controls were tested for the presence of HBsAg and antibody to the hepatitis surface antigen (anti-HBs) at 2 weeks, 8 weeks and 6 months after exposure. All students were negative for HBsAg and anti-HBs on all dates tested and reported no illness during that time suggestive of viral hepatitis. There was no evidence of viral hepatitis, type B transmission from the exposure. The students probably experienced the maximum possible oral exposure from direct or fomites contact, since there was no cleaning of the musical instruments between use by the students and teacher. Based on these results, the risk of transmission of viral hepatitis, type B from oral contact with fomites is unlikely.

  17. Prenatal screening for markers of hepatitis B in aboriginal mothers resident in non-metropolitan Western Australia.

    PubMed

    Moore, D J; Bucens, M R; Holman, C D; Ott, A K; Wells, J I

    Of 1947 Aboriginal women who resided in non-metropolitan regions of Western Australia and gave birth during January 1983 to February 1985, 42% of women were screened prenatally for the presence of hepatitis B surface antigen (HBsAg). The proportions of Aboriginal women who were screened varied from 17% in the southern divisions to 72% in the Kimberley region. The screening programme identified 29 Aboriginal women with a positive result of the test. On this basis, the estimated prevalence of HBsAg among non-metropolitan Aboriginal women was 3.6% (95% confidence interval, 2.5%-5.1%). According to the geographical location of the mother's residence, the observed prevalence of HBsAg varied from 0 in the southern divisions to around 4%-5% in the central and eastern divisions.

  18. [The fabrication of hepatitis B electrochemical immunosensor array].

    PubMed

    Dai, Xiaofeng; Liu, Zhongming

    2008-04-01

    Based on integrate circuit (IC) technology, an eight-channel gold electrodes (GEs) array was developed. The immunosensor array is prepared by co-immobilizing thionine and Hepatitis B (HB) antibody on the gold electrodes through covalently binding them to GEs with a cysteamine/glutaraldehyde linkage. Hepatitis B surface antigen (HBsAg) was detected qualitatively and quantitatively by the peak current decrease percentage of the thionine. HBsAg positive/negative standard serum was well defined by the array. 8-channel synchronous detection for HBsAg was noted to be of good accuracy and reliability. The results of its clinical application were in good agreement with the results from ELISA.

  19. Hepatitis B virus (HBV) and dual HBV-hepatitis delta virus (HDV) infection in apparently healthy persons.

    PubMed

    Brehar-Cioflec, D; Claici, C; Roşiu, N; Negrea, D A; Moldovan, R; Coşniţă, M

    1998-01-01

    The main aims of the present study were to evaluate the transfusional risk concerning HBV and HBV-HDV infections and the prevalence of viral serum markers in apparently healthy persons. Our study included 226 apparently healthy persons in whom we performed tests for HBV (HBsAg, HBsAb, HBcAb) and HDV (Delta Ab) serum markers, using the enzyme immunoassay. In 45 (19.9%) subjects we detected serum HBsAg. In the 181 HBsAg-negative apparently healthy persons, our tests detected HBsAb (31 subjects) and HBcAb (49 subjects). Thus, 125 (55.3%) of the 226 apparently healthy persons had serologic evidence of past HBV infections. Delta Ab were detected in 3 (1.3%) of our subjects. We must state that one of the three Delta Ab-positive apparently healthy persons tested negative for both HBsAg and HBcAb.

  20. [Clinical and immunological studies of an experimental series of vaccines against hepatitis B].

    PubMed

    Teokharova, M P; Andonov, A P; Mineva, E G; Draganov, P I

    1984-01-01

    Two experimental lots of hepatitis B vaccine were prepared by purification of HBsAg from human plasma, inactivation at 100 degrees C for 2 min and at 37 degrees C for 72 hours with formalin in a concentration of 1:4000. The former lot comprises purified HBsAg (40 mg/ml) adsorbed with 0.32 mg % Al(OH)3, the latter consists of purified HBsAg stabilized with 0.1% human albumin and adsorbed with 1 mg% Al(OH)3. The immune response after vaccination with the first lot was observed in 54.54% of the vaccinees. The second vaccine after 3 administrations of 80 micrograms/ml each produced a very good primary and a very good secondary immune response. Both vaccines are nonreactogenic and well tolerated by the vaccinees.

  1. 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.

  2. 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.

  3. The Pan-STARRS-1 Outer Solar System Key Project: A Status Report

    NASA Astrophysics Data System (ADS)

    Holman, Matthew J.

    2014-06-01

    The Pan-STARRS-1 (PS1) survey is capable of detecting slow-moving objects in the outer solar system. Among these are Trojans, Centaurs, long-period comets, short-period comets, and trans-neptunian objects brighter than magnitude 22. We have developed a software pipeline to search for these objects. I will present a status report for this pipeline, as well highlights from the PS1 Outer Solar System Key Project.

  4. Low launch-energy trajectories to the outer solar system via Venus and earth gravity-assist flybys

    NASA Technical Reports Server (NTRS)

    Diehl, Roger; Belbruno, Edward; Bender, David; Myers, Mark; Stetson, Douglas

    1988-01-01

    Recent cancellation of the program to develop a Centaur upper stage for use in the Space Transportation System (STS) has motivated considerable interest in trajectory modes with low launch-energy requirements to the outer solar system. Flyby encounters of the inner planets, especially Venus and earth, may be used to enable missions to Jupiter, Saturn, and a restricted class of comets. An examination of mission opportunities to these targets is presented through the end of this century using gravity-assist trajectories.

  5. Candidate technologies for the Integrated Health Management Program

    NASA Technical Reports Server (NTRS)

    Johnson, Neal F.; Martin, Fred H.

    1993-01-01

    The purpose of this report is to assess Vehicle Health Management (VHM) technologies for implementation as a demonstration. Extensive studies have been performed to determine technologies which could be implemented on the Atlas and Centaur vehicles as part of a bridging program. This paper discusses areas today where VHM can be implemented for benefits in reliability, performance, and cost reduction. VHM Options are identified and one demonstration is recommended for execution.

  6. Research Summary Number 36-14

    DTIC Science & Technology

    1962-05-01

    contacts while minimizing contact of like Contact diagrams may be used to predict the optimum ions; this would be realized near the center of the XY...encountered in working with low con- problem is anticipated. An apparatus is under construc- centrations of microorganisms. Samples containing statis...r. (r + 2I/Vs )] ’ 13 JPL RESEARCH SUMMARY NO. 36-14 Table 1. Nomwenclature Mars trajectory due to the "pessimistic" estimates of the Centaur

  7. 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.

  8. 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.

  9. 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.

  10. X-ray satellite

    NASA Technical Reports Server (NTRS)

    1987-01-01

    As far as technical performance is concerned, the project is still within the previously arranged plan and as far as the launching possibilities are conserned, there is a change from the previous situation. A launch date in 1989 can only be realized with a Delta II, since there is no data available at present for the Atlas/Centaur as to whether and when production will resume.

  11. RTO Technical Publications: A Quarterly Listing

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The titles of five reports are listed here, together with an abstract for each. The titles include: 1) 'Spectral Models of Kuiper Belt Objects and Centaurs'; 2) 'Simulation of and for Military Decision Making'; 3) 'Abundance of the Radioactive Be-10 in the Cosmic Radiation up to 2 GeV/nucleon with the Balloon-borne Instrument ISOMAX1998'; 4) 'Optical Air Flow Measurements in Flight'; 5) 'Flight Test Measurement Techniques for Laminar Flow'.

  12. 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.

  13. A Formal Application of Safety and Risk Assessment in Software Systems

    DTIC Science & Technology

    2004-09-01

    299 2. THERAC –25 RADIATION EXPOSURE INCIDENT ......................300 3. TITAN–4 CENTAUR/MILSTAR FAILURE...Engineering Leveson & Turner wrote in their analysis and summary of the Therac –25 accidents that, “The mistakes that were made are not unique to this...Turner, Clark S.; An Investigation of the Therac -25 Accidents, IEEE Computer Magazine, vol. 26 num 7 pg. 18-41, Institute of Electrical and

  14. 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.

  15. 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....

  16. 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...

  17. Optimization of Lightning Warning Areas at Cape Canaveral/Kennedy Space Center

    DTIC Science & Technology

    2013-06-01

    74  D .  MULTI-OBJECTIVE DECISION ANALYSIS .........................................84  1.  Single-Dimension Value...THIS PAGE INTENTIONALLY LEFT BLANK xv LIST OF ACRONYMS AND ABBREVIATIONS 3- D : 3-Dimensional 45 WS: 45th Weather Squadron AC-67: Atlas/Centaur-67...pair of sensors generates a 3-dimensional (3- D ) hyperbolic surface on which the step leader must lie. Since 3- D locating is being done, four pairs

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. NASA Center update: Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Distefano, Sal

    1993-01-01

    The topics covered are presented in viewgraph form and include the following: flight project support activities for TOPEX and the Mars Observer; and research/development and engineering activities for NiCd model development, secondary lithium battery development, the sodium-NiCl2 moderate temperature battery, Li-SOCl2 batteries for the Centaur launch vehicle, and direct hydrocarbon/methanol fuel cells.

  4. Vapor ingestion in a cylindrical tank with a concave elliptical bottom

    NASA Technical Reports Server (NTRS)

    Klavins, A.

    1974-01-01

    An approximate analytical technique is presented for estimating the liquid residual in a tank of arbitrary geometry due to vapor ingestion at any drain rate and acceleration level. The bulk liquid depth at incipient pull-through is defined in terms of the Weber and Bond numbers and two functions that describe the fluid velocity field and free surface shape appropriate to the tank geometry. Numerical results are obtained for the Centaur LH2 tank using limiting approximations to these functions.

  5. 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

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

    PubMed

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

    2014-01-01

    Hepatitis B virus (HBV) surface antigen (HBsAg) is a reliable marker for HBV infection, but HBsAg-negative forms of HBV infection occur. The introduction of HBV DNA screening of Dutch blood donors, which were not preselected for absence of HBV core antibodies, enabled the characterization of HBsAg-negative HBV infection in healthy persons and a comparison of the HBV genomes involved. The screening of 4.4 million Dutch blood donations identified 23 HBsAg-negative, HBV DNA-positive persons. Serological testing of the index donations, follow-up samples and archived earlier samples was performed to determine the nature of each HBV DNA-only case. Despite low viral loads HBV DNA could be sequenced in 14 out of 23 donors, allowing HBV genotyping and the analysis of mutations in the HBV surface gene. Four types of HBsAg-negative HBV infection were detected: infection in the early stage before occurrence of HBsAg; suppressed infection after vaccination; HBV genotype G infection with decreased HBsAg production; and chronic occult (HBsAg negative) HBV infection. In the donors with occult HBV genotype D infection the HBV surface gene showed multiple "escape" mutations in the HBsAg a-determinant and CTL epitopes, while in an occult genotype A case the surface gene showed no mutations. HBsAg-negative forms of HBV infection in healthy blood donors explain the ongoing transmission of HBV via blood transfusion, if donor screening is limited to HBsAg. The screening of blood donors for HBV DNA and HBV core antibodies seems to cover all stages and variants of HBV infection.

  7. In vitro antigen-induced antibody responses to hepatitis B surface antigen in man. Kinetic and cellular requirements.

    PubMed Central

    Cupps, T R; Gerin, J L; Purcell, R H; Goldsmith, P K; Fauci, A S

    1984-01-01

    In this report we define the parameters of the human immune response after immunization with hepatitis B vaccine. 2 wk after booster immunization, there is significant spontaneous secretion of antibody to hepatitis B surface antigen (anti-HBs IgG), which is not further augmented by stimulation with antigen or pokeweed mitogen (PWM). By 4 wk there is little spontaneous secretion of specific antibody, and low doses of antigen or PWM produce significant increases in the amount of anti-HBs IgG produced. By 8 wk the peripheral blood mononuclear cells are refractory to stimulation by antigen, but anti-HBs IgG is produced in response to PWM. 0.5 yr or more after the last immunization, some individuals will manifest an antigen-induced specific antibody response. This induction of anti-HBs IgG by hepatitis B surface antigen (HBsAg) is monocyte- and T cell-dependent. Note that there is a dichotomy in the T cell response to HBsAg. The specific antibody response is clearly T cell dependent, but no in vitro T cell proliferative response to HBsAG could be demonstrated in the immunized individuals. Although the precise reason for the absent proliferative response to HBsAg despite well-established humoral immunity has not been determined, there was no evidence to suggest nonspecific suppression by HBsAg or the presence of an adherent suppressor cell population. The ability to evaluate antigen-induced, antigen-specific responses to HBsAg will be useful in defining the unique interaction between the human immune response and this clinically important viral agent. PMID:6332826

  8. Characteristics of escape mutations from occult hepatitis B virus infected patients with hematological malignancies in South Egypt

    PubMed Central

    Elkady, Abeer; Iijima, Sayuki; Aboulfotuh, Sahar; Mostafa Ali, Elsayed; Sayed, Douaa; Abdel-Aziz, Nashwa M; Ali, Amany M; Murakami, Shuko; Isogawa, Masanori; Tanaka, Yasuhito

    2017-01-01

    AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus (HBV) infections in patients with hematological malignancies in South Egypt. METHODS Serum samples were collected from 165 patients with hematological malignancies to monitor titers of HBV DNA, hepatitis B surface antigen (HBsAg), and antibodies to HBV core (anti-HBc) and surface antigens. Serum samples negative for HBsAg and positive for anti-HBc were subjected to nucleic acid extraction and HBV DNA detection by real-time polymerase chain reaction. DNA sequences spanning the S region were analyzed in cases with occult HBV infection. In vitro comparative study of constructed 1.24-fold wild type and S protein mutant HBV genotype D clones was further performed. RESULTS HBV DNA was detected in 23 (42.6%) of 54 patients with hematological malignancies who were HBsAg negative, but anti-HBc positive, suggesting the presence of occult HBV infection. The complete HBV genome was retrieved from 6 occult HBV patients, and P120T and S143L were detected in 3 and 2 cases, respectively. Site directed mutagenesis was done to produce 1.24-fold genotype D clones with amino acid mutations T120 and L143. The in vitro analyses revealed that a lower level of extracellular HBsAg was detected by chemiluminescence enzyme immunoassay (CLEIA) with the clone containing T120 mutation, compared with the wild type or the clone with S143L mutation despite the similar levels of extracellular and intracellular HBsAg detected by Western blot. Southern blot experiments showed that the levels of intracellular HBV DNA were not different between these clones. CONCLUSION Occult HBV infection is common in patients with hematological malignancies and associated with P120T and S143L mutations. 120T mutation impairs the detection of HBsAg by CLEIA.

  9. 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

  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. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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).

  18. 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.

  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. Risks Associated with Fresh Whole Blood and Red Blood Cell Transfusions in a Combat Support Hospital

    DTIC Science & Technology

    2007-01-01

    Donorsa HIV (%) 0/460 (0) 0/2371 (0) 0/41,297 (0) HCV (%) 0/406 (0) 3/2427 (0.12) 24/41,297 (0.06) HBsAg (%) 0/406 (0) 0/2427 (0) 26/41,297 (0.06) HTLV ...NA 2/2831 (0.07) 25/41,297 (0.06) HIV, human immunodeficiency virus; HCV, hepatitis C virus; HBsAg, hepatitis B surface antigen; HTLV , human T-cell

  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. 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

  3. The seroprevalences of HBs Ag and anti-HCV in pregnant women in Ankara.

    PubMed

    Altinbas, Sibel; Erdogan, Mine; Danişman, Nuri

    2010-02-01

    In the previous decade, the prevalence of HBs-Ag positivity and the anti-HCV positivity declined in Turkey. We aimed to investigate the prevalences of HBs Ag and anti-HCV positivity in pregnant women in Ankara, the capital city of Turkey, while the vertical transmission should be important way of HBV and HCV transmission. HBs-Ag positivity was determined 2.8% (102) out of 4,700 pregnant women, and 0.1% (6) out of them were positive for anti-HCV. The prevalences of HBs Ag and anti-HCV were both similar to the rate of that seen in western region of Turkey.

  4. 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

  5. 'TNOs are Cool: A survey of the trans-Neptunian region'. Results from the PACS and SPIRE observations with the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lellouch, E.; Mueller, T.; Panuzzo, P.; Santos-Sanz, P.; Lim, T.; Kiss, C.; Vilenius, E.; Stansberry, J.; Delsanti, A.; Henry, F.; Boehnhardt, H.; Pal, A.; Duffard, R.; Barucci, A.

    2012-04-01

    The TNOs are the frozen leftovers from the formation period of the outer solar system. The TNO population comprises (i) the main Kuiper belt beyond the orbit of Neptune consisting of objects in resonant and non-resonant orbits, (ii) the halo outskirts of "scattered" and "detached" bodies, and (iii) the Centaurs, the objects located between Jupiter and Neptune which have origin from the Kuiper belt. Up to date, more than 1500 TNOs and Centaurs have been discovered. Their study reveal a richness of orbital and physical properties. TNOs cover a wide range of intrinsic colours from slightly bluish slopes to the reddest gradients known in the solar system [1]. Spectroscopy confirms the presence of water-ice on the surface of about 30 objects, but also of volatile-ice like methane and perhaps nitrogen on bright objects such as Pluto, Eris, Makemake and Sedna [2]. An Open Time Key Program entitled "TNOs are Cool: A survey of the Transneptunian Region" (PI T. Mueller) was submitted to the Herschel space telescope in order to investigate the albedo, size distribution and thermal properties of these distant and primitive bodies. This proposal has been awarded 372.7 hours to perform radiometric measurements of around 140 TNOs/Centaurs [3]. All the targets are observed with the PACS photometer instrument (3 bands centered at 70, 100 and 160 micron), and only the brightest ones with the SPIRE instrument (with channels centered at 250, 350, and 500 microns). In this work we present the results of the combined SPIRE and PACS instruments observations for the 2 Centaurs Chiron and Chariklo, the dwarf planet Haumea, 2 plutinos (Huya and Orcus), 3 classical TNOs (Quaoar, Salacia and 2002 UX25), and 2002 TC302 (a 2:5 resonant object). The spectral energy distribution of these targets have been modeled with a NEATM thermal model and in cases where rotational properties are known also with a thermophysical model. We will present our results on the size, the albedo, and the thermal

  6. Prevalence and estimation of hepatitis B and C infections in the WHO European Region: a review of data focusing on the countries outside the European Union and the European Free Trade Association.

    PubMed

    Hope, V D; Eramova, I; Capurro, D; Donoghoe, M C

    2014-02-01

    Knowledge of hepatitis B and C prevalence, and numbers infected, are important for planning responses. Published HBsAg and anti-HCV prevalences for the 20 WHO European Region countries outside the EU/EFTA were extracted, to complement published data for the EU/EFTA. The general population prevalence of HBsAg (median 3·8%, mean 5·0%, seven countries) ranged from 1·3% (Ukraine) to 13% (Uzbekistan), and anti-HCV (median 2·3%, mean 3·8%, 10 countries) from 0·5% (Serbia, Tajikistan) to 13% (Uzbekistan). People who inject drugs had the highest prevalence of both infections (HBsAg: median 6·8%, mean 8·2%, 13 countries; anti-HCV: median 46%, mean 46%, 17 countries), and prevalence was also elevated in men who have sex with men and sex workers. Simple estimates indicated 13·3 million (1·8%) adults have HBsAg and 15·0 million (2·0%) HCV RNA in the WHO European Region; prevalences were higher outside the EU/EFTA countries. Efforts to prevent, diagnose, and treat these infections need to be maintained and improved. This article may not be reprinted or reused in any way in order to promote any commercial products or services.

  7. 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.

  8. Oral immunization with hepatitis B surface antigen expressed in transgenic plants.

    PubMed

    Kong, Q; Richter, L; Yang, Y F; Arntzen, C J; Mason, H S; Thanavala, Y

    2001-09-25

    Oral immunogenicity of recombinant hepatitis B surface antigen (HBsAg) derived from yeast (purified product) or in transgenic potatoes (uncooked unprocessed sample) was compared. An oral adjuvant, cholera toxin, was used to increase immune responses. Transgenic plant material containing HBsAg was the superior means of both inducing a primary immune response and priming the mice to respond to a subsequent parenteral injection of HBsAg. Electron microscopy of transgenic plant samples revealed evidence that the HBsAg accumulated intracellularly; we conclude that natural bioencapsulation of the antigen may provide protection from degradation in the digestive tract until plant cell degradation occurs near an immune effector site in the gut. The correlate of protection from hepatitis B virus infection is serum antibody titers induced by vaccination; the protective level in humans is 10 milliunits/ml or greater. Mice fed HBsAg-transgenic potatoes produced HBsAg-specific serum antibodies that exceeded the protective level and, on parenteral boosting, generated a strong long-lasting secondary antibody response. We have also shown the effectiveness of oral delivery by using a parenteral prime-oral boost immunization schedule. The demonstrated success of oral immunization for hepatitis B virus with an "edible vaccine" provides a strategy for contributing a means to achieve global immunization for hepatitis B prevention and eradication.

  9. Twenty-year survey of the epidemiology of hepatitis B in Denmark: effect of immigration.

    PubMed

    Gjørup, I E; Smith, E; Borgwardt, L; Skinhøj, P

    2003-01-01

    Implementation of hepatitis B virus (HBV) vaccination is being considered in Denmark. Therefore, a 20 y survey on the epidemiology of HBV infection was performed. All notified cases of acute HBV infection in Denmark from 1982 to 2002 were reviewed retrospectively and all available data from 1970 to 2001 on the prevalence of hepatitis B surface antigen (HBsAg) in different groups of the Danish population were studied. The notified annual incidence of acute HBV infection has declined from more than 200 cases to fewer than 50 cases in 2001. In the indigenous population there has been a similar decline in prevalence of HBsAg carriers, from 0.15 to 0.03%, but owing to immigration of new HBsAg carriers from developing countries the overall number of carriers has not changed. The small effect of immigration on the incidence of acute HBV infections as well as the decreasing prevalence of HBsAg carriers among Danes should be taken into account when planning new vaccination strategies in Denmark.

  10. Construction and identification of Complex DNA vaccine of hepatitis B and Toxoplasma gondii

    PubMed Central

    Wei, Qing-Kuan; Xiao, Ting; Li, Jin; Yin, Kun; Jia, Feng-Ju; Xu, Chao; Zhao, Gui-Hua; Cui, Yong; Liu, Gong-Zhen; Sun, Hui; Jiang, Hong-Tao; Yan, Ge; Huang, Bing-Cheng

    2015-01-01

    Objective: To construct and identify multi-gene recombinant expression vector pcDNA3-HBsAg-p30-ROP2. Method: Primers were designed according to the gene sequences of restriction enzyme cutting site of recombinant pcDNA3-p30-ROP2 and hepatitis B surface antigen (HBsAg). The target fragment of HBsAg was amplified and cloned to expression vector pcDNA3-p30-ROP2 by restriction enzyme digestion and ligation. The recombinant expression vector pcDNA3-HBsAg-p30-ROP2 was identified by PCR detection, followed by enzyme restriction and sequencing. Results: The target fragment of HBsAg was successfully amplified, and the multi-gene eukaryotic expression vector pcDNA3-HBsAg-p30-ROP2 was established. PCR detection and restriction enzyme digestion showed that the length of the target fragment was consistent with the theoretical value. The recombinant expression vector contained the complete sequences of p30-ROP2 compound gene and HBsAg. Conclusion: Multi-gene recombinant expression vector pcDNA3-HBsAg-p30-ROP2 was successfully established. The constructed expression vector could be used to develop multi-gene nucleic acid vaccines. PMID:26309572

  11. Epidemiology of hepatitis B virus infection: results from a community-based study of 0.15 million residents in South China

    PubMed Central

    Zeng, Fangfang; Guo, Pi; Huang, Yun; Xin, Wei; Du, Zhicheng; Zhu, Shuming; Deng, Yu; Zhang, Dingmei; Hao, Yuantao

    2016-01-01

    Limited information is available about the current epidemic status of hepatitis B virus (HBV) in Guangdong province in South China, where hepatitis B is endemic. We sought to provide an up-to-date assessment of hepatitis B prevalence in a large population through a community-based study. A total of 169,211 local residents were recruited using the stratified cluster random sampling method from 2014 to 2015, and each participant’s information was collected using an interviewer-administered questionnaire. Accordingly, the prevalence of hepatitis B surface antigen (HBsAg) in the total population was 8.76%. HBsAg prevalence was lowest (0.29%) among children aged 0–12 years and highest (12.71%) among those aged 23–59 years. Moreover, the prevalence (8.82%) in males approximately equalled that (8.65%) in females (P > 0.05). Overall, vaccination was effective in preventing HBV infection, regardless of age. Among adults aged 23–59 years, male sex tended to keep the HBsAg persistence. However, reduced persistence for participants with occasional physical exercise and drinking was observed. For participants older than 59 years, a history of prior surgery placed people at high risk for infection. Although Guangdong has successfully decreased the HBsAg prevalence among children, it is urgent to expand vaccination to adults, and employ interventions to reduce the infection risk. PMID:27819332

  12. Hepatitis B surface antigen seroprevalence among children in Papua New Guinea, 2012-2013.

    PubMed

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

    2015-03-01

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

  13. Human Leukocyte Antigens Influence the Antibody Response to Hepatitis B Vaccine.

    PubMed

    Jafarzadeh, Abdollah; Bagheri-Jamebozorgi, Masoome; Nemati, Maryam; Golsaz-Shirazi, Forough; Shokri, Fazel

    2015-06-01

    Hepatitis B virus (HBV) infection and its sequelae such as cirrhosis and hepatocellular carcinoma has remained a serious public health problem throughout the world. The WHO strategy for effective control of HBV infection and its complications is mass vaccination of neonates and children within the framework of Expanded Programme on Immunization (EPI). Vaccination with hepatitis B surface antigen (HBsAg) induces protective antibody response (anti-HBs ≥ 10 IU/L) in 90-99% of vaccinees. The lack of response to HBsAg has been attributed to a variety of immunological mechanisms, including defect in antigen presentation, defect in HBsAg-specific T and/or B cell repertoires, T-cell suppression, increase in the regulatory T cell count, lack of necessary help of T-cells for production of anti-HBs by B cells, defect in Th1 and/or Th2 cytokine production and selective killing of HBsAg-specific B-cells by human leukocyte antigen (HLA)-restricted cytotoxic T lymphocytes. The HLA complex plays an important role in many of these immunological processes. A variety of HLA class I, II, and III alleles and antigens have been reported to be associated with antibody response to HBsAg vaccination in different ethnic populations. Moreover, some HLA haplotypes were also associated with responsiveness to HBsAg. In this review the association of the HLA specificities with antibody response to hepatitis B (HB) vaccine is discussed.

  14. Seroprevalence of hepatitis B virus infection and seroconvertion to anti-HBsAg in laboratory staff in Goiânia, Goiás.

    PubMed

    Silva, Paula Andréia; Fiaccadori, Fabíola Souza; Borges, Ana Maria Tavares; Silva, Simone Almeida; Daher, Roberto Ruhman; Martins, Regina Maria Bringel; Cardoso, Divina das Dores de Paula

    2005-01-01

    Were analyzed 648 serum samples from laboratory staff in Goiânia, Goiás aiming detection of three serological markers of HBV: HBsAg, anti-HBsAg and anti-HBcAg. The HBsAg and anti-HBcAg positive samples were also analyzed for HBeAg, anti-HBeAg and anti-HBcAgIgM markers. HBV infection rate of 24.1% was observed and, from them, 0.7% were positive for HBsAg. Viral DNA was detected by PCR in two HBsAg positive samples. A vaccination index of 74.5% and a global index of 89.9% of serological response to vaccination were observed. The direct work with biological fluids as well as cleaning workers represented significant risks for acquisition of HBV infection. The data from the present study showed an increase of the vaccination index among laboratory staff but the rates of HBV infection did not change through the years in the region.

  15. Hepatitis B viral antigenic structure: signature analysis by monoclonal radioimmunoassays.

    PubMed Central

    Wands, J R; Wong, M A; Shorey, J; Brown, R D; Marciniak, R A; Isselbacher, K J

    1984-01-01

    An approach has been developed for the analysis of hepatitis B viral (HBV) antigenic structure that creates numerical "signatures" of HBV strains. This technique employs high-affinity IgM and IgG monoclonal antibodies (anti-HBsAg) directed toward distinct and separate determinants on hepatitis B surface antigen (HBsAg). Such antibodies have been used to develop sensitive and specific radioimmuno-assays for measurement of HBsAg-associated determinants in serum. In performing "signature" analysis separate binding curves for each monoclonal anti-HBsAg are generated by measuring immunoreactivity in serial dilutions of HBsAg-positive serum. Since the HBsAg concentration in serum is unknown, the binding profiles of groups of samples from the same "classic" HBV subtype are aligned by an iterative maximum likelihood procedure to give the numerical signature of that HBV subtype. By using this approach, HBsAg shows far more antigenic heterogeneity than previously recognized by polyvalent anti-HBsAg antibodies. Indeed, there are subgroups within the classic HBsAg subtypes. In addition, the a domain (common to all known subtypes or strains of HBV) has been shown to be multideterminant. Thus, these studies have demonstrated heretofore unrecognized differences in HBV subtypes. This approach also has broader significance for the study of subtle or major antigenic changes among other viral agents since it is not necessary to know the concentration of virus or viral protein in complex protein mixtures. PMID:6585796

  16. The Relationship between Serum Bilirubin and Elevated Fibrotic Indices among HBV Carriers: A Cross-Sectional Study of a Chinese Population

    PubMed Central

    Du, Min; Zhang, Shanshan; Xiao, Lin; Xu, Yanyan; Liu, Peiyi; Tang, Yuhan; Wei, Sheng; Xing, Mingyou; Miao, Xiaoping; Yao, Ping

    2016-01-01

    The study probed the association between bilirubin and hepatitis B virus (HBV) infection and progression. A cross-sectional analysis of 28,500 middle aged and elderly Chinese participants was performed to analyze the differences of bilirubin in terms of hepatitis B surface antigen (HBsAg) positive or negative and the correlation between bilirubin and severity of hepatic fibrosis estimated by non-invasive indices. Bilirubin was significantly higher in the HBsAg (+) group than the HBsAg (−) group. Higher bilirubin levels were consistently associated with elevated liver fibrosis indices among HBsAg carriers. Compared with quartile 1 of total bilirubin (TBil), the multivariable-adjusted ORs (95% CIs) for elevated fibrosis indices of quartile 4 were 2.24 (95% CIs, 1.57–3.21) estimated by fibrosis 4 score (FIB-4) and 2.22 (95% CIs, 1.60–3.08) estimated by aspartate transaminase to platelet ratio index (APRI). In addition, direct bilirubin (DBil) had a stronger association with elevated liver fibrosis indices than did indirect bilirubin (IBil). Furthermore, the relationship between DBil and elevated fibrosis indices was more robust among participants who were female, overweight or had central fat distribution. These findings suggested that bilirubin levels, especially DBil, were independently associated with an increased risk of increased fibrosis indices. PMID:27941693

  17. Immune response to hepatitis B vaccine in a group of health care workers in Sri Lanka.

    PubMed

    Chathuranga, L S; Noordeen, F; Abeykoon, A M S B

    2013-11-01

    Health care workers (HCWs) are considered at high risk of acquiring the hepatitis B virus (HBV). Seroconversion rates after vaccination against HBV among HCWs have not previously been available in Sri Lanka. In the current study, the response to HBV surface antigen (HBsAg) vaccine was assessed in a selected group of HCWs by testing for antibodies against HBsAg (anti-HBs). This was a retrospective descriptive study to measure the anti-HBs levels, using an ELISA, in an immunized group of HCW referred to Department of Microbiology, Faculty of Medicine, University of Peradeniya, Sri Lanka. Among the 342 participants, 9.9% (n=34) were non-responders. Female participants had a significantly higher immune response (94.7%) than males (p<0.05). The results of the study found no significant decline in the immune response with time (p > 0.05). Post HBsAg vaccination immunity in HCW in Sri Lanka is similar to that of global rates with similar gender variation. Anti-HBs levels should be tested in all HCW following HBsAg vaccination so that necessary precautions can be taken.

  18. Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients

    PubMed Central

    Alvarez-Muñoz, Ma Teresa; Maldonado-Rodriguez, Angelica; Rojas-Montes, Othon; Torres-Ibarra, Rocio; Gutierrez-Escolano, Fernanda; Vazquez-Rosales, Guillermo; Gomez, Alejandro; Muñoz, Onofre; Torres, Javier; Lira, Rosalia

    2014-01-01

    AIM: To determine the frequency of occult hepatitis B infection (OHBI) in a group of human immunodeficiency virus (HIV)-1+/ hepatitis B surface antigen negative (HBsAg)- patients from Mexico. METHODS: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus (HBV) DNA was analyzed using nested PCR to amplify the Core (C) region and by real-time PCR to amplify a region of the S and X genes. The possible associations between the variables and OHBI were investigated using Pearson’s χ2 and/or Fisher’s exact test. RESULTS: We found that the frequency of OHBI was 49% among the group of 49 HIV-1+/HBsAg- patients studied. The presence of OHBI was significantly associated with the HIV-1 RNA viral load [odds ratio (OR) = 8.75; P = 0.001; 95%CI: 2.26-33.79] and with HIV-antiretroviral treatment with drugs that interfere with HBV replication (lamivudine, tenofovir or emtricitabine) (OR = 0.25; P = 0.05; 95%CI: 0.08-1.05). CONCLUSION: The OHBI frequency is high among 49 Mexican HIV-1+/HBsAg- patients and it was more frequent in patients with detectable HIV RNA, and less frequent in patients who are undergoing HIV-ARV treatment with drugs active against HBV. PMID:25309083

  19. Fluoroimmunoassay for antigen based on fluorescence quenching between quantum dots and gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Huang, Peng; Wang, Kan; Pandoli, Omar; Zhang, Xueqing; Gao, Feng; Shao, Jun; You, Xiaogang; He, Rong; Song, Hua; Cui, Daxiang

    2010-11-01

    A unique, sensitive, and highly specific fluoroimmunoassay system for antigen detection using gold and quantum dot nanoparticles has been developed. The assay is based on the fluorescence quenching of quantum dots caused by gold nanoparticles coated with antibody. To demonstrate its analytical capabilities, the CdTe quantum dots were coated with anti-HBsAg monoclonal antibodies (QDs-MAb1) and gold nanoparticles coated with another anti-HBsAg monoclonal antibodies (GNPs-MAb2) which specifically bound with HBsAg could sandwich the HBsAg captured by the immunoreactions. The sandwich-type immunocomplex was formed and the fluorescence intensity of quantum dots was measured. The results showed that the fluorescence intensity of quantum dots at 570 nm was negative linear proportional to the HBsAg concentration logarithm, and the limit of detection of the HBsAg was 0.928 ng/mL. This new system can be extended to detect target molecules with matched antibodies and has broad potential applications in immunoassay and disease diagnosis.

  20. 21 CFR 1270.21 - Determination of donor suitability for human tissue intended for transplantation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2 (e.g., FDA licensed screening test for anti-HIV-2); (3) Hepatitis B (e.g., FDA licensed screening test for HBsAg); and (4) Hepatitis C (e.g., FDA licensed screening test for anti-HCV). (b) In the case... been tested and found negative using FDA licensed screening tests for HIV-1, HIV-2, hepatitis B,...

  1. 21 CFR 1270.21 - Determination of donor suitability for human tissue intended for transplantation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2 (e.g., FDA licensed screening test for anti-HIV-2); (3) Hepatitis B (e.g., FDA licensed screening test for HBsAg); and (4) Hepatitis C (e.g., FDA licensed screening test for anti-HCV). (b) In the case... been tested and found negative using FDA licensed screening tests for HIV-1, HIV-2, hepatitis B,...

  2. 21 CFR 1270.21 - Determination of donor suitability for human tissue intended for transplantation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2 (e.g., FDA licensed screening test for anti-HIV-2); (3) Hepatitis B (e.g., FDA licensed screening test for HBsAg); and (4) Hepatitis C (e.g., FDA licensed screening test for anti-HCV). (b) In the case... been tested and found negative using FDA licensed screening tests for HIV-1, HIV-2, hepatitis B,...

  3. 77 FR 14801 - Request for Information (RFI) on Design of a Pilot Operational Study To Assess Alternative Blood...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-13

    ...- transmissible infections (e.g. Human Immunodeficiency Virus (HIV) and Hepatitis B Virus (HBV)) in some groups of... transfusion-transmissible infections (e.g. HIV, HBV, and Hepatitis C Virus (HCV)) obtained from routine... NAT), Antibody to HTLV-I and -II (Anti-HTLV-I/II), Hepatitis B Surface Antigen (HBsAg), Antibody...

  4. 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

  5. PROSPECTIVE POPULATION MANAGEMENT FOR HEPATITIS B IN THE CHIMPANZEE (PAN TROGLODYTES) SSP® POPULATION.

    PubMed

    Meals, Laura Cummins; Ross, Stephen R; Eng, Curtis; Gamble, Kathryn C

    2016-09-01

    Hepatitis B virus causes horizontally transmitted infectious hepatopathy of primates and may progress to hepatocellular carcinoma. Historically, a small number of chimpanzees ( Pan troglodytes ) living in accredited North American zoos have been confirmed with positive hepatitis B serology consistent with exposure. However, the overall status for this population and the interpretation of these individual test results have not been established previously. The current U.S. zoo-housed population (n = 259) was assessed serologically for hepatitis B by surface protein antigen (HbsAg) and surface antibodies (anti-Hbs). Signalment, origin, current health status, history of liver disease, and hepatitis B vaccination history were obtained for each animal. Serologic status was measured directly in 86.5% (n = 224) of these individuals, with 2.2% (n = 5) of the study population determined to be chronically infected by positive HbsAg and negative anti-Hbs status. Additionally, 11.6% (n = 26) of the directly measured population tested were HbsAg negative and anti-Hbs positive, which was indicative of viral exposure. No animals were determined to be acutely infected as HbsAg and anti-Hbs positive. Although these results demonstrated a relatively low prevalence of hepatitis B infection among these chimpanzees, the varied serologic results between institutions underscored the importance of routine serologic testing, especially at times of proposed transfers, and consideration of species vaccination protocols.

  6. Virological and serological features of acute hepatitis B in adults

    PubMed Central

    Du, Xiaofei; Liu, Yali; Ma, Lina; Lu, Junfeng; Jin, Yi; Ren, Shan; He, Zhimin; Chen, Xinyue

    2017-01-01

    Abstract Various viral kinetics among patients with acute hepatitis B (AHB) have been observed in clinical practice. This study investigated the virological, biochemical, and serological characteristics of AHB in adults. A total of 192 adult patients with AHB were recruited between December 2010 and January 2014. The quantification of biochemical and serologic markers for hepatitis B virus (HBV) infection was monitored from the onset. Of the 192 patients, 113 patients were followed up. One patient died due to acute liver failure, 2 developed chronic HBV infection. Clinical recovery was observed in 110 patients; 92.7% (102/110) achieved clinical recovery within 24 weeks, and 7.3% (8/110) between 24 and 44 weeks. There were 3 different viral kinetics patterns among the patients with AHB: the clearance of HBV DNA preceded hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg), the clearance of HBeAg preceded HBV DNA and HBsAg, the clearance of HBsAg preceded HBV DNA and HBeAg. In the absence of HBV DNA clearance within 13 weeks, the risk of development of chronic HBV infection increased. The serologic HBV markers clearance occurred between 24 and 44 weeks (6–11 months) from the onset in 8 of the AHB patients, which was longer than 6 months. Thus, AHB may be redefined as HBV DNA undetectable, HBsAg and HBeAg seroconversion within 44 weeks. PMID:28207518

  7. 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

  8. 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

  9. Long-term persistence of hepatitis B surface antigen and antibody induced by DNA-mediated immunization results in liver and kidney lesions in mice.

    PubMed

    Zi, Xiao-Yuan; Yao, Yu-Cheng; Zhu, Hai-Ying; Xiong, Jun; Wu, Xiu-Ju; Zhang, Nan; Ba, Yue; Li, Wen-Lin; Wang, Xin-Ming; Li, Jian-Xiu; Yu, Hong-Yu; Ye, Xu-Ting; Lau, Joseph T Y; Hu, Yi-Ping

    2006-04-01

    DNA-mediated immunization has been recognized as a new approach for prevention and treatment of hepatitis B virus (HBV) infection. However, the side effects of this approach have not been well described. Here we report that DNA-mediated immunization by intramuscular injection of plasmid DNA encoding HBV surface antigen (HBsAg) induced long-term persistence of HBsAg and HBsAg-specific antibody (anti-HBs) in the sera of the immunized BALB/c mice and resulted in liver and kidney lesions. The lesions persisted for 6 months after injection. Lesions were also found in normal mice injected with the sera from immunized mice, and in HBV-transgenic mice injected with anti-HBs antibody, or sera from immunized mice. Furthermore, lesions were accompanied by deposition of circulating immune complex (CIC) of HBsAg and anti-HBs antibody in the damaged organs. These results indicate that long-term persistence of HBsAg and anti-HBs in the immunized mice can result in deposited CIC in liver and kidney, and in development of lesions. The use of DNA containing mammalian replication origins, such as the plasmids used in this study, is not appropriate for human vaccines due to safety concerns relating to persistence of DNA; nevertheless, the safety of DNA-mediated immunization protocols still needs to be carefully evaluated before practical application.

  10. Sero-Prevalence of Hepatitis B Surface Antigen Amongst Pregnant Women Attending an Antenatal Clinic, Volta Region, Ghana

    PubMed Central

    Dassah, Sylvester; Lokpo, Sylvester; Ameke, Louise; Noagbe, Mark; Adatara, Peter; Hagan, Oheneba; Binka, Fred

    2017-01-01

    Hepatitis B virus (HBV) infection remains a global challenge, although there is currently a safe and effective vaccine available. HBV prevalence in Ghana is not well documented, but vary regionally from 4.8% to 12.3% in the general population, 10.8% to 12.7% in blood donors and about 10.6% in pregnant women. This puts Ghana among the high endemic countries in Africa. The study objective was to determine the sero-prevalence of HBs antigen (Ag) and HBeAg among pregnant women in the Ho municipality. Two hundred and eigh participants (pregnant women), attending Ho Municipal antenatal clinic were enrolled into the study. This study recorded a HBsAg sero-prevalence rate of 2.4% among the pregnant women, with primigravida pregnant women recording (0.98%) and multigravida (1.42%). The prevalence of HBsAg among the pregnant women can be classified as Low Intermediate; therefore there is still the need for routine screening of pregnant women during antenatal visits. Amongst HBsAg positives, HBeAg positivity was significantly high (40% of all HBsAg positive women), which suggests high chances of carrier and vertical transmission (mother to child) state. PMID:28299162

  11. 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.

  12. 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

  13. Hepatitis B virus markers in the population of Dar es Salaam, Tanzania.

    PubMed

    Haukenes, G; Shao, J F; Mbena, E; Rustad, S

    1987-09-01

    A total of 542 serum samples from healthy adults (medical students and medical staff, blood donors and pregnant women) residing in or near the city of Dar es Salaam, Tanzania were examined for markers of hepatitis B virus (HBV) infection. Of these samples, 95 (17.5%) were not found to contain any HBV marker when examined by enzyme-linked immunoassay for hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs) and antibody to hepatitis B core antigen (anti-HBc). HBsAg was demonstrated in 52 (9.6%) samples of which 7 (13.5%) were positive for hepatitis Be antigen (HBeAg) and 17 (32.7%) were positive for anti-HBc IgM. None of 9 HBsAg positive pregnant women were carriers of HBeAg. These results show that hepatitis B infection is very common in this country. The relatively low prevalence of HBeAg among HBsAg carriers may indicate that transmission of hepatitis B at birth is not of major importance.

  14. Efficacy of post-exposure prophylaxis with hepatitis B immunoglobulin in Norway.

    PubMed

    Winsnes, R; Siebke, J C

    1986-01-01

    The efficacy of hepatitis B immunoglobulin (HBIG) in preventing infection by hepatitis B virus (HBV) after exposure to blood or blood-containing secretions that carried hepatitis B surface antigen (HBsAg), was studied in an uncontrolled trial in Norway from 1976-1983. Of the 177 HBIG recipients, followed up for 5-24 months, 166 were exposed by needle-stick, splash on mucous membranes or open wounds, sexual contact or medical investigation. With few exceptions, this group was given a single injection of 1250 IU of antibody to HBsAg (anti-HBs) within 7 days after exposure. One person developed clinical hepatitis B (HB) of short duration and two others developed anti-HBs. Six infants with perinatal exposure were injected with three or four doses of about 1250 IU anti-HBs at intervals of 2-3 months. The first dose was given immediately after birth. One child developed clinical HB at the age of 14 months and recovered. Of five patients exposed by blood transfusion, four developed clinical HB; the fifth apparently developed passive-active immunity. One of the four probably became an HBsAg carrier. These patients, except the one without clearance of HBsAg, received one to seven doses of HBIG within 2 days after exposure. Administration of HBIG after needle-stick and similar types of exposure, as well as administration to infants at risk of contracting HB, seems to be of great value.

  15. Efficacy of selective antenatal screening for hepatitis B among pregnant women in Denmark: is selective screening still an acceptable strategy in a low-endemicity country?

    PubMed

    Jensen, Lise; Heilmann, Carsten; Smith, Else; Wantzin, Per; Peitersen, Birgit; Weber, Tom; Krogsgaard, Kim

    2003-01-01

    The prevalence of hepatitis B virus (HBV) carriage in Denmark is unknown, but expected to be low (0.1%). This study aimed to evaluate the efficacy of selective antenatal screening for HBV infection and the epidemiology of HBV and hepatitis C virus (HCV) among pregnant women. 4098 women were included in the study. Blood tests were examined for hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc) and anti-HCV. Case records were studied to evaluate whether patients at risk for HBV infection had been tested. Among the 4098 women, 18 10.4%, 95% confidence interval (95% CI) 0.3-0.71 were HBsAg positive. All had a risk factor for HBV infection. Only 13 (72%) were identified as HBsAg positive in the selective screening programme. 115 women (2.8%, 95% CI 2.3-3.4) were anti-HBc positive only. 95 (83%) were at risk for HBV. Only 72 of these (63%) were tested for HBsAg. The screening programme in this area of Denmark did not pick up one-third of pregnant women at risk of HBV.

  16. Effectiveness of the Targeted Hepatitis B Vaccination Program in Greenland

    PubMed Central

    Koch, Anders; Biggar, Robert J.; Ladefoged, Karin; Melbye, Mads; Wohlfahrt, Jan; Krause, Tyra Grove

    2012-01-01

    Objectives. To evaluate the effectiveness of the hepatitis B virus (HBV) vaccination program in Greenland, which targets children born to mothers who are positive for HBV surface antigen (HBsAg), we determined vaccination coverage, levels of postvaccination antibodies, and frequency of breakthrough infections in at-risk children. Methods. We conducted a population-based retrospective cohort study with data from nationwide registries. We identified all children born to HBsAg-positive mothers from 1992 to 2007 and collected data on their HBV vaccination status. In 2008 to 2010, we tested the children for HBV core antibody, HBsAg, and anti-HBsAg antibody (HBsAb). Results. Of 4050 pregnant women, 3.2% were HBsAg positive. Of 207 children born to these women, 20% received no vaccinations, and only 58% received at least 3 vaccinations. At follow-up, HBsAb levels in vaccinated children were much lower than expected, and 8 (6%) of 140 at-risk children had breakthrough infections, with 4 chronically infected (persistently HBsAg positive). Conclusions. The prevention program targeting children at risk for HBV in Greenland is ineffective. HBV vaccination should be included in the universal childhood vaccination program, and postvaccination HBsAb levels should be monitored. PMID:21940914

  17. New therapeutic perspectives in HBV: when to stop NAs.

    PubMed

    Pérez-Cameo, Cristina; Pons, Mònica; Esteban, Rafael

    2014-02-01

    The goal of chronic hepatitis B (CHB) treatment is to achieve seroclearance of HBsAg. Nucleos(t)ide analogues (NAs) are one of the first-line treatments for CHB. NAs produce a potent suppression of viral replication but are associated with a low rate of HBsAg seroclearance and a high risk of virological relapse after discontinuation. Because of these reasons, long-term treatment is needed. They are well-tolerated oral drugs, and it seems they do not produce important side-effects in long-term administration. The duration of NA treatment remains unclear, nevertheless, in some patients NAs can be stopped with a low rate of relapse. HBeAg-positive patients could discontinue NA therapy if they achieved HBeAg seroclearance and maintain undetectable HBV DNA. For HBeAg-negative patients, to stop NA treatment is not recommended. In addition to other factors, serum HBsAg titres during treatment have recently been proposed to guide NA-based therapy duration in selected patients. All patients could be stopped from taking treatment if they achieve HBsAg loss.

  18. Hepatitis B surface antigen in blood donors: further observations.

    PubMed

    Szmuness, W; Hirsch, R L; Prince, A M; Levine, R W; Harley, E J; Ikram, H

    1975-02-01

    A survey of 128,000 volunteer blood donors from the Greater New York metropolitan area revealed that first-time male donors were positive for hepatitis B surface antigen (HBsAg) 2.5 times more frequently than were first-time female donors; Negroes and Mongols were positive four to 20 times more frequently than Caucasians. The ratio of ad to ay seemed to be higher in non-Caucasian antigen carriers than in Caucasian carriers. Among both Caucasians and non-Caucasians the rate of positivity declined after the age of 50. An excess prevalence of HBsAg was observed in donors with the lowest level of education and in those with the highest level. HBsAg was detectable nine times less frequently among repeat donors than among first-time donors (0.2 vs.1.90 per 1,000). Detection of HBsAg was unrelated to ABO-Rh blood groups. Several mechanisms for these wide variations of antigen detection are possible.

  19. Cell-mediated immunity to hepatitis B virus antigens in mice: correlation of in vivo and in vitro assays.

    PubMed Central

    De Moerloose, P A; Frazer, I H; Sewell, W A; Collins, E J; Mackay, I R

    1986-01-01

    Cell mediated immunity (CMI) to hepatitis B viral antigens was studied in BALB/mice after immunization with purified hepatitis B surface antigen (HBsAg), or core antigen (HBcAg), with adjuvants. The two in vitro assays for cell-mediated immunity (CMI), utilizing lymph node cells, were release of interferon after exposure to antigen, and blast transformation of lymphocytes, and the in vivo assay was ear swelling at 24 h after local injection of antigen. Immunization with HBsAg or HBcAg with adjuvants induced antigen-specific cutaneous reactivity; if no adjuvants were given, immunization with HBcAg, but not HBsAg, induced cutaneous reactivity. CMI could be adoptively transferred by lymph node cells, but for only a limited period after immunization with HbsAg or HBcAg. The ability of lymph node cells from mice immunized with HBV antigens to transfer adoptively CMI correlated well with their production of interferon after challenge with antigen in vitro, but less well with blastogenesis after challenge with antigen in vitro, or with cutaneous reactivity to antigen in the donor mouse. Reliable antigen-specific lymphokine release assays, rather than blast transformation of lymphocytes or cutaneous reactivity after antigen challenge, are required to assess CMI to HBV antigens in the mouse and, by inference, in man. Images Fig. 1 PMID:3091300

  20. 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

  1. 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.

  2. 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

  3. Hepatitis B virus surface antigen selectively inhibits TLR2 ligand-induced IL-12 production in monocytes/macrophages by interfering with JNK activation.

    PubMed

    Wang, Sen; Chen, Zhiao; Hu, Conghua; Qian, Fangxing; Cheng, Yuming; Wu, Min; Shi, Bisheng; Chen, Jieliang; Hu, Yunwen; Yuan, Zhenghong

    2013-05-15

    It is widely accepted that chronic hepatitis B virus (HBV) infection is the result of an ineffective antiviral immune response against HBV infection. Our previous study found that the hepatitis B surface Ag (HBsAg) was related to decreased cytokine production induced by the TLR2 ligand (Pam3csk4) in PBMCs from chronic hepatitis B patients. In this study, we further explored the mechanism involved in the inhibitory effect of HBsAg on the TLR2 signaling pathway. The results showed that both Pam3csk4-triggered IL-12p40 mRNA expression and IL-12 production in PMA-differentiated THP-1 macrophage were inhibited by HBsAg in a dose-dependent manner, but the production of IL-1β, IL-6, IL-8, IL-10, and TNF-α was not influenced. The Pam3csk4-induced activation of NF-κB and MAPK signaling were further examined. The phosphorylation of JNK-1/2 and c-Jun was impaired in the presence of HBsAg, whereas the degradation of IκB-α, the nuclear translocation of p65, and the phosphorylation of p38 and ERK-1/2 were not affected. Moreover, the inhibition of JNK phosphorylation and IL-12 production in response to Pam3csk was observed in HBsAg-treated monocytes/macrophages (M/MΦs) from the healthy donors and the PBMCs and CD14-positive M/MΦs from chronic hepatitis B patients. Taken together, these results demonstrate that HBsAg selectively inhibits Pam3csk4- stimulated IL-12 production in M/MΦs by blocking the JNK-MAPK pathway and provide a mechanism by which HBV evades immunity and maintains its persistence.

  4. Seroprevalence of hepatitis B virus infection among children and adolescents in Singapore, 2008-2010.

    PubMed

    Ang, Li Wei; Tey, Su Hui; Cutter, Jeffery; James, Lyn; Goh, Kee Tai

    2013-04-01

    A national pediatric survey was undertaken to determine the prevalence of hepatitis B virus markers in Singapore. The aim was to assess the impact of the national childhood immunization program against hepatitis B implemented for all newborns since 1987. The survey involved prospective collection of residual sera from Singapore residents aged 1-17 years attending inpatient services or day surgery in two public hospitals between August 2008 and July 2010. A total of 1,200 sera were collected comprising 400 in each of the three age groups of 1-6, 7-12, and 13-17 years. The sera were tested for hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs). Four of the 1,200 samples tested positive for HBsAg, giving an overall prevalence of 0.3%. One and three in the 7-12 years and 13-17 years age groups, respectively, were positive for HBsAg. About 40% possessed anti-HBs (≥10 mIU/ml); the antibody prevalence decreased significantly from 63.8% in children aged 1-6 years to 32.8% in 7-12 year olds, and 23.5% in 13-17 year olds (P < 0.0005). The successful implementation of the national childhood hepatitis B immunization program over the last two decades has resulted in a low prevalence of HBsAg among children and adolescents. Singapore has achieved the World Health Organization Western Pacific Region's goal in reducing the prevalence of chronic HBV infection to below 2% among children aged 5 years and older by 2012 and to below 1% by 2017.

  5. Increase of the prevalence of hepatitis B virus surface antigen related to immunodeficiency inherent in acquired immune deficiency syndrome (AIDS).

    PubMed

    Ouattara, S A; Meite, M; Aron, Y; Akran, V; Gody, M; Manlan, L K; de-The, G

    1990-01-01

    During the period from January to December 1987, 2,191 serum samples were collected from different groups of the population in the Ivory Coast (1,126 healthy people selected from the general population, 416 blood donors, 112 healthy anti-HIV carriers, 173 AIDS patients, and 364 patients suffering from icterigenic hepatitis) and tested for anti-HIV (HIV-1 and HIV-2) antibodies, HBsAg, HBeAg, delta antigen (HDAg), and anti-delta (anti-HD) antibody. Anti-HIV antibodies were found in 30 (2.6%) of the general population. 55 (13.2%) blood donors, and 93 (25.5%) patients suffering from icterigenic hepatitis. HBsAg was observed in 103 (9.1%) of the general population, 45 (10.8%) blood donors, 15 (13.4%) healthy anti-HIV carriers, 59 (34.1%) AIDS patients, and 45 (40%) icterigenous hepatitis patients. The simultaneous presence of anti-HIV and HBsAg was noted in 4 (0.4%) of the general population, 8 (2%) blood donors, 15 (13.4%) healthy anti-HIV carriers, 59 (34.1%) AIDS cases, and 36 (10%) patients suffering from icterigenic hepatitis. A high prevalence of HBeAg and serological markers of infection by the delta agent were noted in the different groups. HDAg was noted only among AIDS patients or those suffering from icterigenic hepatitis, with a higher frequency among anti-HIV carriers. Our conclusion from this study is that healthy anti-HIV carriers are no more likely to be HBsAg carriers than the HIV-seronegative subjects. However, immunodeficiency induced previously by HIV infection is likely to be responsible for the high prevalence of HBsAg among AIDS patients.

  6. Clinical features and viral quasispecies characteristics associated with infection by the hepatitis B virus G145R immune escape mutant.

    PubMed

    Xue, Yuan; Wang, Ming-Jie; Yang, Zhi-Tao; Yu, De-Min; Han, Yue; Huang, Dao; Zhang, Dong-Hua; Zhang, Xin-Xin

    2017-03-22

    Coexistence of the hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) is an uncommon phenomenon, and the underlying mechanisms remain largely unknown. Amino-acid (aa) substitution from glycine to arginine at aa 145 (G145R), in the major hydrophilic region, has been reported in patients with HBsAg and anti-HBs coexistence. However, there is limited knowledge about the clinical features and viral quasispecies characteristics associated with G145R mutant hepatitis B virus (HBV) infection. We herein describe the dynamic changes in the serological and virological markers in a case of hepatitis B with coexisting HBsAg and anti-HBs, caused by a G145R immune escape mutant (genotype C). Entecavir was administered during the 4th week after admission. Alanine aminotransferase peaked in the 16th week, while both the HBsAg and HBeAg declined rapidly. HBsAg clearance and hepatitis B e antigen (HBeAg)/hepatitis B e antibody (anti-HBe) seroconversion were achieved in the 36th week, and then entecavir was withdrawn. A follow-up of 96 weeks showed that HBV DNA remained undetectable and that anti-HBs was maintained above 100 mIU/mL. The quasispecies characteristics of the G145R mutant HBV were investigated via ultra-deep sequencing. The complexity and genetic distance of the S and RT regions were much higher in the 8th week than at baseline or in the 4th week. Moreover, the frequencies of mutations (L173P, Q181R and A184V) in cytotoxic T lymphocyte epitopes increased before entecavir treatment. These findings extend understanding of the evolution of HBV under host immune pressure and of the clinical outcomes of affected patients.

  7. Seroprevalence of hepatitis B and immune response to hepatitis B vaccination in Chinese college students mainly from the rural areas of western China and born before HBV vaccination integrated into expanded program of immunization.

    PubMed

    Liao, Xue-Yan; Zhou, Zhen-Zuo; Wei, Fu-Bang; Qin, Han-Ning; Ling, Yuan; Li, Rong-Cheng; Li, Yan-Ping; Nong, Yi; Sun, Kui-Xia; Li, Jie; Zhuang, Hui

    2014-01-01

    The prevalence of hepatitis B surface antigen (HBsAg) in a population aged 15 y or older was high in China, but an immunization strategy for this population was unavailable. We investigated the seroprevalence of hepatitis B and immune response to HBV vaccine in Chinese college students (n=2040 participants), 11.1%, 80.8%, and 8.1% had confirmed, unknown and no HBV vaccination history, respectively. The seropositive rates for HBsAg, anti-HBs sole and anti-HBs plus anti-HBc were 12.6%, 25.7%, and 30.1%, respectively. The HBsAg seropositive rate was significantly lower in participants with confirmed HBV vaccination history than in those with unknown or no vaccination history (5.3%, 13.6%, and 12.6%, respectively, P=0.0019). The anti-HBs alone seropositive rate was significantly higher in participants with confirmed HBV vaccination history than in those with unknown or no vaccination history (37.6%, 25.3%, and 13.8%, respectively, P<0.0001). Participants negative for HBsAg, anti-HBs, and anti-HBc at baseline (n=600) were given three doses of recombinant HBV vaccine (GlaxoSmithKline) at month 0, 1, and 6. Robust immune response was elicited after two and three doses (seroprotective rate: 91.9% and 99.0%, respectively, and geometric mean concentration [GMC]: 95.8 and 742.6 IU/L, respectively). Fourteen months after the third dose, the anti-HBs seroprotective rate of the group remained more than 97%. The seroprotective rates and GMCs did not differ significantly by vaccination history. This study suggested that three doses of 20 μg HBV vaccine were needed for college students negative for HBsAg, anti-HBs, and anti-HBc to ensure high seroprotective rates and concentrations.

  8. Clinical significance of antibody to hepatitis B core antigen in multitransfused hemodialysis patients

    PubMed Central

    Elghannam, Doaa M.; Aly, Rabab M.; Goda, Enas F.; Eltoraby, Ehab E.; Farag, Raghda E.

    2009-01-01

    Background: In spite of the progress made in the prevention of transfusion transmitted infections over the last few years, transmission of HBV infection through transfusion of HBsAg negative blood has been documented. Objectives: To assess the frequency and clinical significance of anti-HBc in multitransfused hemodialysis patients. Materials and Methods: One hundred and forty-three hemodialysis patients who had been receiving blood regularly with an average of 39.4 ± 7.579 months on hemodialysis were enrolled in this study. HBV markers (HBsAg, anti-HBc, anti-HBs) were measured in these patients and in 100 healthy controls by the ELISA technique. The following data were obtained for all patients: socio demographic data, number of blood transfusions and some laboratory investigations. Results: In our patients, anti-HBc was positive in 9%, anti HBs in 7%, coexistant HbsAg/anti-HBc in 2.8% and anti HBc/anti HBs in 18.9%, meanwhile no patients were positive for HBsAg alone. In patients with only positive anti-HBc, the levels of anti-HBc were significantly related to abnormal results of liver function. In patients with positive anti-HBs/anti-HBc (n = 27), 18 patients had abnormal liver function, and 9 patients had normal liver function with no significant difference between them. Conclusions: This study suggests that hepatitis B prevalence in our multitransfused hemodialysis patients is far in excess of that anticipated on the basis of HBsAg prevalence. Absence of HBsAg in the blood of hemodialyzed patients may not be sufficient to ensure lack of circulating HBV, and isolated positivity of anti-HBc may be a possible indicator of active hepatitis B infection. PMID:20041091

  9. Evaluation of the Impact of Hepatitis B Vaccination in Adults in Jiangsu Province, China

    PubMed Central

    Zhu, Yefei; Xu, Weiguo; Bao, Changjun; Peng, Hong; Bian, Qian; Yang, Haitao; Wang, Hua; Hu, Zhibin; Shen, Hongbing

    2014-01-01

    Hepatitis B immunization programs for newborns, children, and adolescents in China have shown remarkable results. To establish whether there would be any benefit in extending the program to cover older individuals, we examined both the epidemiology of hepatitis B virus (HBV) infection and the coverage of hepatitis B vaccinations among adults born before routine vaccinations were implemented. We then evaluated the impact of hepatitis B vaccination in adults aged 20–59 years. A large-scale cross-sectional epidemiological survey of HBV infection was performed in the province of Jiangsu, south-east China, between September 2009 and March 2010. A total of 86,732 adults aged 20–59 years were included, of which 8,615 (9.9%, 95% CI = 9.7–10.1%) were HBsAg sero-positive. Self-reported vaccination status suggested that the coverage was approximately 23.7% (95% CI = 23.4–24.0%). It was shown that higher HBV vaccination coverage was associated with a lower rate of HBsAg seropositivity among adults. There was a negative correlation between hepatitis B vaccination coverage and HBsAg prevalence (correlation coefficient = −0.805, p = 0.016), which might demonstrate the combined effects of vaccination and pre-vaccination HBsAg screening. In the unvaccinated group, the HBsAg-positive rate had an obvious upward trend with age growing among 20–39 year-olds (Trend χ2 = 22.605, P<0.001), while the vaccinated group showed no such trend (Trend χ2 = 3.462, P = 0.063). Overall, hepatitis B vaccination in adults might reduce the rate of HBsAg positivity. Therefore, routine immunization of adults aged 20–39 years should be seriously considered. PMID:24979048

  10. 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.

  11. Post-transfusion hepatitis. Sudden drop of its incidence associated with hyperbilirubinemic donors disqualification.

    PubMed

    Pintera, J; Krácmar, C; Pinterová, A

    1986-01-01

    The lacking impact of various precautions on the incidence of post-transfusion hepatitis (PTH) in the last 15 years is presented. In 1984, however, PTH dropped from 0.12 to 0.04%. This PTH drop did not coincide with the disqualification of HBsAg carriers, nor with that of high ALT, nor with the introduction of complete voluntary donorship in 1982, but with the systematic exclusion of hyperbilirubinemic donors. Circulating immune complexes (CIC) were found in 28.9% of PTH compromised donors, and CIC are therefore supposed to be a marker of PTH risk even if HBsAg was not demonstrable. Re-examining donors compromised in 120 PTH found 12.4% HBsAg carriers who had not been detected by CIEP prior to the transfusions. Accumulation of more than one HBsAg positive transfusion in 56.5% of the PTH patients suggests a cumulative effect. The inability of specific tests to identify sources of infection in 50% of PTH suggests that doubts must be raised as to their post-transfusional origin. This thesis is also supported by the relative increase of this group after the considerable drop of PTH. The importance of viral sources non-B and B undetectable by sensitive specific methods must be emphasized. The latter is in accordance with the observed PTH drop due to a non-specific marker effect. The bilirubin level screening in each donor before stored blood collection is recommended by means of the described extended AST screening test and, besides HBsAg screening, this is supposed to be the most effective precaution for preventing PTH.

  12. Simple high-cell density fed-batch technique for high-level recombinant protein production with Pichia pastoris: Application to intracellular production of Hepatitis B surface antigen

    PubMed Central

    Gurramkonda, Chandrasekhar; Adnan, Ahmad; Gäbel, Thomas; Lünsdorf, Heinrich; Ross, Anton; Nemani, Satish Kumar; Swaminathan, Sathyamangalam; Khanna, Navin; Rinas, Ursula

    2009-01-01

    Background Hepatitis B is a serious global public health concern. Though a safe and efficacious recombinant vaccine is available, its use in several resource-poor countries is limited by cost. We have investigated the production of Hepatitis B virus surface antigen (HBsAg) using the yeast Pichia pastoris GS115 by inserting the HBsAg gene into the alcohol oxidase 1 locus. Results Large-scale production was optimized by developing a simple fed-batch process leading to enhanced product titers. Cells were first grown rapidly to high-cell density in a batch process using a simple defined medium with low salt and high glycerol concentrations. Induction of recombinant product synthesis was carried out using rather drastic conditions, namely through the addition of methanol to a final concentration of 6 g L-1. This methanol concentration was kept constant for the remainder of the cultivation through continuous methanol feeding based on the on-line signal of a flame ionization detector employed as methanol analyzer in the off-gas stream. Using this robust feeding protocol, maximum concentrations of ~7 grams HBsAg per liter culture broth were obtained. The amount of soluble HBsAg, competent for assembly into characteristic virus-like particles (VLPs), an attribute critical to its immunogenicity and efficacy as a hepatitis B vaccine, reached 2.3 grams per liter of culture broth. Conclusion In comparison to the highest yields reported so far, our simple cultivation process resulted in an ~7 fold enhancement in total HBsAg production with more than 30% of soluble protein competent for assembly into VLPs. This work opens up the possibility of significantly reducing the cost of vaccine production with implications for expanding hepatitis B vaccination in resource-poor countries. PMID:19208244

  13. Visible and near-IR observations of transneptunian objects. Results from ESO and Calar Alto Telescopes

    NASA Astrophysics Data System (ADS)

    Boehnhardt, H.; Tozzi, G. P.; Birkle, K.; Hainaut, O.; Sekiguchi, T.; Vair, M.; Watanabe, J.; Rupprecht, G.; FORS Instrument Team

    2001-11-01

    We present visible (BVRI) and near-IR (JHKs) broadband photometry and visible low-dispersion spectroscopy of Transneptunian Objects (TNOs) and Centaurs. In total, 16 TNOs and 1 Centaur were observed over the past two years at ESO telescopes in La Silla and Paranal in Chile as well as at the Calar Alto Observatory in Spain. The sample consists of objects measured for the first time and those for which comparison data is available from literature. The targets were: 1992QB1, 1993RO, 1994EV3, 1995HM5, 1995SM55, 1996RQ20, 1996TL66, 1996TO66, 1996TP66, 1997CQ29, 1997CS29, 1998HK151, 1998TF35, 1998VG44, 1998WH24, 1998XY95, 1999TC36. The spectra of 5 TNOs (1995SM55, 1996TO66, 1997CQ29, 1997CS29, 1998HK151) show almost constant gradients over the visible wavelength range with only marginal indication for a flatter slope beyond 750-800 nm. The photometric colour gradients obtained quasi-simultaneously are in good agreement with the spectral data. This suggests that in general photometric colour gradients are a valuable diagnostic tool for spectral type classification of TNOs. The photometric study revealed a number of new objects with neutral and red colours. For re-measured objects the published broadband colours were - in general - confirmed, although a few remarkable exceptions exist. Two TNOs appear to be outlyers according to the available broadband colours: 1993EV3 and 1995HM5. 1995SM55 is the bluest TNO measured so far. No clear global correlation between V-I colour and absolute R filter brightness of our TNO targets is found. However, the data for the 5 brightest TNOs (brighter than 5 mag absolute magnitude) could also be interpreted with a linear increase of V-I colour by about 0.75 mag per brightness magnitude. The colour-colour diagrams show continuous reddening of the TNOs in V-R vs. B-V, R-I vs. B-V and R-I vs. V-R. The bimodality suggested from earlier measurements of Tegler & Romanishin (\\cite{Tegler98}) is not confirmed. According to our colour gradient

  14. Effect of switching from treatment with nucleos(t)ide analogs to pegylated interferon α-2a on virological and serological responses in chronic hepatitis B patients

    PubMed Central

    He, Li-Ting; Ye, Xiao-Guang; Zhou, Xiao-Yuan

    2016-01-01

    AIM To investigate the efficacy of switching to pegylated interferon-α-2a (PegIFNα-2a) treatment in nucleos(t)ide analog (NA)-treated chronic hepatitis B (CHB) responder patients. METHODS A 48-wk prospective and retrospective treatment trial of NA-treated CHB patients who had received entecavir (ETV) for at least 48 wk and had serum hepatitis B virus (HBV)-DNA < 500 IU/mL, serum hepatitis B envelope antigen (HBeAg) < 100 S/CO, serum alanine aminotransferase, and aspartate aminotransferase levels < 2 × the upper limit of normal of 40 IU/L was performed. The effects on virological and serological responses and adverse reactions to 0.5 mg daily ETV for 48 wk vs switching to PegIFNα-2a were compared. Forty-four patients were randomized to be switched from NA treatment to the PegIFNα-2a group, and 44 patients were simultaneously randomized to the ETV group. RESULTS After 48 wk of therapy, the decrease in hepatitis B surface antigen (HBsAg) levels was greater in the PegIFNα-2a group than in the ETV group (3.1340 log10 IU/mL vs 3.6950 log10 IU/mL, P = 0.00). Seven patients who were anti-HBs-positive at baseline achieved HBsAg loss when switched to PegIFNα-2a (15.91% vs 0%, P = 0.018). The HBeAg serological conversion rate was higher in the PegIFNα-2a group than in the ETV group; however, the difference was not significant because of the small sample sizes (34.38% vs 21.88%, P = 0.232). In the PegIFNα-2a group, patients with HBsAg levels < 1500 IU/mL at baseline had higher HBeAg seroconversion and HBsAg loss rates at week 48 than those with HBsAg levels ≥ 1500 IU/mL (HBeAg seroconversion: 17.86% vs 62.5%, P = 0.007; HBsAg loss: 41.67% vs 6.25%, P = 0.016). Moreover, patients with HBsAg levels < 1500 IU/mL at week 24 had higher HBsAg loss rates after therapy than those with HBsAg levels ≥ 1500 IU/mL (36.84% vs 0%, P = 0.004). However, there were no statistically significant differences in HBeAg seroconversion rates (47.06% vs 25.93%, P = 0.266). CONCLUSION NA

  15. 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.

  16. 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.

  17. The Large-Grained Dust Coma of 174P/Echeclus

    NASA Technical Reports Server (NTRS)

    Bauer, James M.; Choi, Young-Jun; Weissman, Paul R.; Stansberry, John A.; Fernandez, Yanga R.; Roe, Henry G.; Buratti, Bonnie J.; Sung, Hyun-Il

    2008-01-01

    On 2005 December 30, Y.-J. Choi and P. R. Weissman discovered that the formerly dormant Centaur 2000 EC98 was in strong outburst. Previous observations by P. Rousselot et al. spanning a 3-year period indicated a lack of coma down to the 27 mag arcsec 2 level.We present Spitzer Space Telescope MIPS observations of this newly active Centaur--now known as 174P/Echeclus (2000 EC98)--or 60558 Echeclus--taken in 2006 late February. The images show strong signal at both the 24 and 70 micron bands and reveal an extended coma about 2' in diameter. Analyses yield estimates of the coma signal contribution that are in excess of 90% of the total signal in the 24 micron band. Dust production estimates ranging from 1.7-4 x 10(exp 2) kg/s are on the order of 30 times that seen in other Centaurs. Simultaneous visible-wavelength observations were also obtained with Palomar Observatory's 200-inch telescope, the 1.8-m Vatican Advanced Technology Telescope, the Bohyunsan Optical Astronomy Observatory (BOAO) 1.8-m telescope, and Table Mountain Observatory's 0.6-m telescope, revealing a coma morphology nearly identical to the mid-IR observations. The grain size distribution derived from the data yields a log particle mass power-law with slope parameter (alpha) = -0.87 +/- 0.07, and is consistent with steady cometary-activity, such as that observed during the Stardust spacecraft's encounter at 81P/Wild 2, and not with an impact driven event, such as that caused by the Deep Impact experiment.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. Possible origin of the Saturn satellite, Phoebe

    NASA Astrophysics Data System (ADS)

    Di Sisto, R. P.; Brunini, A.

    The orbit of the outermost Saturn's irregular moon, Phoebe, suggests that it was captured by Saturn rather than formed in situ. The Cassini-Huygens mission results allowed to find that Phoebe's composition is similar to that derived for the outer solar system bodies and very different from the composition of the Saturn regular satellites. In this paper we present new results suggesting that Phoebe could be a component of a binary centaur captured by Saturn during a three-body gravitational encounter. FULL TEXT IN SPANISH

  5. Meeting with a majestic giant - The Cassini mission to Saturn

    NASA Astrophysics Data System (ADS)

    Kohlhase, Charley

    1993-08-01

    A Cassini mission to Saturn scheduled for launch on board of a two-story-high robotic spacecraft in October 1997 is described. The spacecraft characterized by a mass of about 2,500 kg of dry hardware and 3,000 kg of propellant will need a boost from the Titan IV/Centaur launch vehicle and several planetary gravity assists. The mission is aimed at delivering a European-built probe to the large, hazy moon Titan, and then touring the saturnian system for nearly four years. The Cassini mission is initiated by NASA, the ESA, and the Italian Space Agency.

  6. Navigation and performance analysis of a Mars surface sample return /MSSR/ mission

    NASA Technical Reports Server (NTRS)

    Satin, A. L.; Asnin, S. K.

    1974-01-01

    A Viking-derived MSSR mission involves a rendezvous in Mars orbit between the sample-carrying Mars Ascent Vehicle (MAV) and a modified Viking Orbiter spacecraft. Conditions for the automatic terminal rendezvous phase are established by an initial earth-controlled phase which uses very accurate relative state information obtained by multi-vehicle interferometric tracking data. A navigation analysis has demonstrated sufficient performance and control capability to satisfy those conditions prior to terminal rendezvous. Specific performance constraints for the mission are developed, leading to a sizing of vehicle weight requirements and trades applicable to a 1981 MSSR, launched by a single Titan IIIE/Centaur.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. On the anisotropy of E 0 ⩾ 5.5× 1019 eV cosmic rays according to data of the Pierre Auger Collaboration

    NASA Astrophysics Data System (ADS)

    Glushkov, A. V.

    2012-02-01

    The Pierre Auger Collaboration discovered, in a solid angle of radius about 18°, a local group of cosmic rays having energies in the region E 0 ≥ 5.5 × 1019 eV and coming from the region of the Gen A radio galaxy, whose galactic coordinates are l G = 309.5° and b G = 19.4°. Near it, there is the Centaur supercluster of galaxies, its galactic coordinates being l G = 302.4° and b G = 21.6°. It is noteworthy that the Great Attractor, which may have a direct bearing on the observed picture, is also there.

  15. Current trajectory options for a comet nucleus sample return mission

    NASA Astrophysics Data System (ADS)

    Sauer, Carl G., Jr.

    1992-08-01

    A summary of the current trajectory options available for the ESA comet nucleus sample return mission, Rosetta, is presented. These options include direct trajectories, delta-V-EGA trajectories using a Titan IV/Centaur launch vehicle with upgraded solid rocket motors, a trajectory involving a gravity assist of the earth (VEGA) prior to comet rendezvous, and one involving an additional gravity assist of the earth (VEEGA). Other propulsion options proposed and discussed are solar electric propulsion/ballistic trajectory modes and nuclear electric propulsion trajectory modes. Tables of performance data for each of these trajectory options are given.

  16. 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.

  17. Development and test of a liquid hydrogen propellant tank foam insulation

    NASA Astrophysics Data System (ADS)

    Gruszczynski, Michael J.; Gagliani, John; Thorp, Vernon L.; Heim, Walter J.; Swanson, Neil J.

    An external bonded foam insulation system has been developed and tested for the Atlas II Centaur cryogenic upper stage pressure-stabilized hydrogen propellant tank. This bonded foam insulation system replaces the jettison panel system used on the Atlas I upper stage propellant tank since 1962. A closed-cell polyvinyl chloride foam bonded to the stainless steel tank wall with a modified epoxy adhesive was selected as the insulation system. Vehicle-level cryogenic tanking tests and supersonic aerodynamic wind tunnel heating tests were conducted to simulate the vehicle system environment and were successful in qualifying this system for flight.

  18. 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.

  19. 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.

  20. 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.