bluuebunny/crossref_metadata_2025 huggingface dataset:
Isotope anomalies in tellurium and palladium from Allende nanodiamonds
Authors: Maas R. , Loss R. D. , Rosman K. J. R. , De Laeter J. R. , Lewis R. S. , Huss G. R. , Lugmair G. W.
Published: February 2010

Abstract— ‐The elemental and isotopic abundances of Te and Pd have been measured by thermal ionization mass spectrometry in a purified sample of interstellar nanodiamonds from the Allende meteorite, after combustion of the diamonds in an oxygen plasma. Small positive anomalies were found in 128Te (4.0 ± 1.5 %0) and 130Te (9.3 ± 2.8 %0) from three analyses of the Allende nanodiamond sample EB, and in 110Pd (9.4 ± 5.7 %0) from two analyses of the same sample. No other anomalies of a significant nature were found in either Te or Pd. These results are consistent with the neutron burst model (Meyer et al., 2000), and the r‐process based rapid separation model of Ott (1996) in that 128, 130Te and 110Pd are enhanced relative to their solar abundances. However, in the framework of the neutron burst model, some separation between stable products and radioactive precursors may be required in order to be consistent with the full data set of Te isotopes. In the framework of the rapid separation scenario, our data suggests a separation time of approximately 4000 s, based on the magnitudes of the precursor life‐times for 128Te and 130Te. The elemental abundance ratio Te‐H/Xe‐H agrees with the prediction of the rapid separation model, provided little fractionation occurred during trapping of the exotic components by the diamonds, but differs significantly from expectations based on the neutron burst model. Differences in the inferred 128Te/130Te ratio between our work and that of Richter et al. (1998) point to the need for further investigations.
Molecular and chiral analyses of some protein amino acid derivatives in the Murchison and Murray meteorites
Authors: PIZZARELLO Sandra , COOPER George W.
Published: February 2010

Abstract— The varied organic suite extracted from the Murchison meteorite contains several amino acids that are common to the biosphere. Some of these have been found to be non‐racemic, but the indigenous nature of their L‐enantiomeric excesses has been subject to debate in view of possible terrestrial contamination. We have investigated two amino acids of common terrestrial and meteoritic occurrence, alanine and glutamic acid, and assessed their indigenous enantiomeric ratios in the Murchison and Murray meteorites through the ratios of some of their derivatives. Analyzed were N‐acetyl alanine, α‐imino propioacetic acid, N‐acetyl glutamic acid and pyroglutamic acid.

Both alanine derivatives were found to be racemic, while those of glutamic acid showed L‐enantiomeric excesses varying from 16% to 47.2% for pyroglutamic acid, and from 8.6% to 41% for N‐acetyl glutamic acid. The δ13C was determined for the two enantiomers of Murchison pyroglutamic acid both before and after acid hydrolysis to glutamic acid. The values of +27.7%0 (D‐pyro), +10.0%0 (L‐pyro), +32.2%0 (D‐glu) and +14.6%0 (L‐glu) were obtained.

The racemic nature of alanine derivatives strongly suggests that alanine itself, as indigenous to the meteorite, is racemic. The explanation of the L‐enantiomeric excesses found for glutamic acid derivatives is less direct; however, the variability of the enantiomeric ratios for these compounds and the distinctly lower δ13C values determined for pyroglutamic L‐enantiomer point to a terrestrial contamination, possibly dating to the time of fall.
The Leonard Award Address: Presented 2000 August 30, Chicago, Illinois, USA: Early solar system events and timescales
Authors: LUGMAIR G. W. , SHUKOLYUKOV A.
Published: February 2010

Abstract— Some recent information on the Mn‐Cr and Al‐Mg systems is reviewed. This information is used to derive constraints on the timing of processes and events, which took place in the early solar system. Using reasonable assumptions, a timeline is constructed where the estimated age of the solar system is ∼4571 Ma. This age is taken to mark the time when most calcium‐aluminum‐rich inclusions (CAIs) were starting to form, a process that may have lasted for several 105 years. Almost contemporaneously small planetesimals have accreted that served to store these CAIs for later dispersal among larger planetesimals. By the time large numbers of planetesimals of several tens of kilometers in size had formed, the interior of these objects started to melt through the decay of 26Al. Collisional disruption of these planetesimals allowed gases, dust, and melt to escape into the surrounding space. The fine droplets of melt reacted with gas and dust to form chondrules, which, after rapid cooling, were partially re‐accreted onto the residual rubble pile. This process of primary chondrule formation, in most cases involving several generations of planetesimals, most plausibly lasted only for ∼2 Ma. Towards the end of this period and during the following 3 to 4 Ma planetary objects of several hundred kilometers in size were formed. They still stored enough energy to continue melting from the inside to finally differentiate into chemically stratified layers, with basaltic volcanism occurring within a few million years.
Korra Korrabes: A new, large H3 chondrite breccia from Namibia
Authors: ASHWAL L. D.
Published: February 2010

Abstract— A new, large, ordinary chondrite has been recovered from near the strewn field of Gibeon iron meteorites in Namibia, and is designated Korra Korrabes, after the farm property on which the specimens were found in 1996–2000. A total of ∼140 kg of related specimens were recovered, including a large stone of 22 kg, and hundreds of smaller objects between 2 g and several kilograms. Cut surfaces indicate that Korra Korrabes is a breccia, containing 10–20% of light grey‐brown clasts up to 3 cm across in a uniform, darker grey‐brown host that contains abundant round chondrules, and irregular grains of Fe‐Ni metal and troilite up to 1 cm across. The vast majority of the stone is unshocked, although some clasts show mild shock features (stage S2), and one chondrule fragment is moderately shocked (stage S3). Weathering grade varies between W1 and W2. Microprobe analyses indicate variable compositions of olivine (Fa13.8–27.2, n = 152, percent mean deviation = 7.82%) and low‐Ca pyroxene (multiply twinned clinobronzite, Fs8.4–27.8, n = 68). There is excellent preservation of magmatic textures and mineralogy within many chondrules, including normally zoned olivine (Fa13.8–18.9) and low‐Ca pyroxene (Fs0.2–20.9) phenocrysts, and abundant glass, some of whose compositions are unusually alkaline (Na2O + K2O = 13.6–16.3 wt%) and Ca‐deficient (CaO = 0‐0.75 wt%), seemingly out of magmatic equilibrium with associated clinoenstatite or high‐Al calcic clinopyroxene crystals. Textural and mineralogical features indicate that Korra Korrabes is an H3 chondrite breccia, which represents the largest and least equilibrated stony meteorite yet recovered from Namibia; it is now one of the four largest unequilibrated ordinary chondrites worldwide.
The antiquity indicator argon‐40/argon‐36 for lunar surface samples calibrated by uranium‐235‐xenon‐136 dating
Authors: EUGSTER Otto , TERRIBILINI Dario , POLNAU Ernst , KRAMERS Jan
Published: February 2010

Abstract— Several solar gas rich lunar soils and breccias have trapped 40Ar/36Ar ratios >10, although solar Ar is expected to yield a ratio of <0.01. Radiogenic 40Ar produced in the lunar crust from 40K decay was outgassed into the lunar atmosphere, ionized, accelerated in the electromagnetic field of the solar wind, and reimplanted into lunar surface material. The 40Ar loss rate depends on the decreasing abundance of 40K. In order to calibrate the time dependence of the 40Ar/36Ar ratio in lunar surface material, the period of reimplantation of lunar atmospheric ions and of solar wind Ar was determined using the 235U‐136Xe dating method that relies on secondary cosmic‐ray neutron‐induced fission of 235U. We identified the trapped, fissiogenic, and cosmogenic noble gases in lunar breccia 14307 and lunar soils 70001‐8, 70181, 74261, and 75081. Uranium and Th concentrations were determined in the 74261 soil for which we obtain the 235U‐136Xe time of implantation of 3.25+0.38‐0.60 Ga ago. On the basis of several cosmogenic noble gas signatures we calculate the duration of this near surface exposure of 393 ± 45 Ma and an average shielding depth below the lunar surface of 73 ± 7 g/cm2. A second, recent exposure to solar and cosmic‐ray particles occurred after this soil was excavated from Shorty crater 17.2 ± 1.4 Ma ago. Using a compilation of all lunar data with reliable trapped Ar isotopic ratios and pre‐exposure times we infer a calibration curve of implantation times, based on the trapped40 Ar/36Ar ratio. A possible trend for the increase with time of the solar 3He/4He and 20Ne/22Ne ratios of about 12%/Ga and about 2%/Ga, respectively, is also discussed.
Refractory calcium‐aluminum‐rich inclusions and aluminum‐diopside‐rich chondrules in the metal‐rich chondrites Hammadah al Hamra 237 and Queen Alexandra Range 94411
Authors: KROT Alexander N. , McKEEGAN Kevin D. , RUSSELL Sara S. , MEIBOM Anders , WEISBERG Michael K. , ZIPFEL Jutta , KROT Tatiana V. , FAGAN Timothy J. , KEIL Klaus
Published: February 2010

Abstract— The metal‐rich chondrites Hammadah al Hamra (HH) 237 and Queen Alexandra Range (QUE) 94411, paired with QUE 94627, contain relatively rare (<1 vol%) calcium‐aluminum‐rich inclusions (CAIs) and Al‐diopside‐rich chondrules. Forty CAIs and CAI fragments and seven Al‐diopside‐rich chondrules were identified in HH 237 and QUE 94411/94627. The CAIs, ∼50–400 μm in apparent diameter, include (a) 22 (56%) pyroxene‐spinel ± melilite (+forsterite rim), (b) 11 (28%) forsterite‐bearing, pyroxene‐spinel ± melilite ± anorthite (+forsterite rim) (c) 2 (5%) grossite‐rich (+spinel‐melilite‐pyroxene rim), (d) 2 (5%) hibonite‐melilite (+spinel‐pyroxene ± forsterite rim), (e) 1 (2%) hibonite‐bearing, spinel‐perovskite (+melilite‐pyroxene rim), (f) 1 (2%) spinel‐melilite‐pyroxene‐anorthite, and (g) 1 (2%) amoeboid olivine aggregate. Each type of CAI is known to exist in other chondrite groups, but the high abundance of pyroxene‐spinel ± melilite CAIs with igneous textures and surrounded by a forsterite rim are unique features of HH 237 and QUE 94411/94627. Additionally, oxygen isotopes consistently show relatively heavy compositions with Δ17O ranging from −6%0 to −10%0 (1σ = 1.3%0) for all analyzed CAI minerals (grossite, hibonite, melilite, pyroxene, spinel). This suggests that the CAIs formed in a reservoir isotopically distinct from the reservoir(s) where “normal”, 16O‐rich (Δ17O < −20%0) CAIs in most other chondritic meteorites formed.

The Al‐diopside‐rich chondrules, which have previously been observed in CH chondrites and the unique carbonaceous chondrite Adelaide, contain Al‐diopside grains enclosing oriented inclusions of forsterite, and interstitial anorthitic mesostasis and Al‐rich, Ca‐poor pyroxene, occasionally enclosing spinel and forsterite. These chondrules are mineralogically similar to the Al‐rich barred‐olivine chondrules in HH 237 and QUE 94411/94627, but have lower Cr concentrations than the latter, indicating that they may have formed during the same chondrule‐forming event, but at slightly different ambient nebular temperatures. Aluminum‐diopside grains from two Al‐diopside‐rich chondrules have O‐isotopic compositions (Δ17O ≅ −7 ± 1.1 %0) similar to CAI minerals, suggesting that they formed from an isotopically similar reservoir. The oxygen‐isotopic composition of one Ca, Al‐poor cryptocrystalline chondrule in QUE 94411/94627 was analyzed and found to have Δ17O ≅ −3 ± 1.4%0.

The characteristics of the CAIs in HH 237 and QUE 94411/94627 are inconsistent with an impact origin of these metal‐rich meteorites. Instead they suggest that the components in CB chondrites are pristine products of large‐scale, high‐temperature processes in the solar nebula and should be considered bona fide chondrites.
Pattern of Serum Cytokine Expression and T-Cell Subsets in Sickle Cell Disease Patients in Vaso-Occlusive Crisis
Authors: Musa Bolanle O. P. , Onyemelukwe Geoffrey C. , Hambolu Joseph O. , Mamman Aisha I. , Isa Albarka H.
Published: February 2010

The pathogenesis of sickle vaso-occlusive crisis (VOC) in sickle cell disease (SCD) patients involves the accumulation of rigid sickle cells and the stimulation of an ongoing inflammatory response, as well as the stress of infections. The immune response, via cytokine imbalances and deregulated T-cell subsets, also has been proposed to contribute to the development of VOC. In this study, a panel of high-sensitivity cytokine kits was used to investigate cytokines in the sera of SCD patients in VOC. The results were compared primarily with those for stable SCD patients and secondarily with those for normal healthy people who served as controls. The cytokines studied included interleukin-2 (IL-2), IL-4, and IL-10. Lymphocyte subsets of patients with VOC were also studied and were compared with those of both control groups (20 stable patients without crisis [SCD group] and 20 normal healthy controls [NHC]). The VOC group was notable for remarkably elevated levels of IL-4, among the three cytokines tested, compared with those for the SCD and NHC groups. Patients with VOC also differed from stable SCD patients and NHC by having notably lower IL-10 levels, as well as the lowest ratio of CD4+to CD8+T cells (0.7). The patterns of the proinflammatory cytokine IL-2 did not differ between VOC and stable SCD patients, but NHC had significantly lower IL-2 levels than both the VOC and SCD groups. Our results demonstrate coexisting levels, both high and low, of TH1- and TH2-type cytokines, as well as diminished levels of T-cell subsets in VOC. These results are discussed in an effort to better understand the importance of the immune system profile in the pathogenesis of sickle cell VOC. Since the possibility that a cytokine imbalance is implicated in the pathogenesis of sickle cell crisis has been raised, our results should prompt further investigation of the host immune response in terms of TH1 and TH2 balance in sickle cell crisis.
Progesterone and 17β-Estradiol Enhance Regulatory Responses to Human Papillomavirus Type 16 Virus-Like Particles in Peripheral Blood Mononuclear Cells from Healthy Women
Authors: Marks Morgan A. , Gravitt Patti E. , Burk Robert D. , Studentsov Yevgeniy , Farzadegan Homayoon , Klein Sabra L.
Published: February 2010

Human papillomavirus (HPV) virus-like particle (VLP) vaccines are highly effective at preventing viral infections and the development of precancerous lesions through the induction of high-titer neutralizing antibodies and strong cell-mediated immune responses. Women taking combined oral contraceptives (COCs), however, show large variabilities in the magnitudes of their antibody responses. The goal of the present study was to determine the effects of 17β-estradiol (E2) and progesterone (P4) alone and in combination on the cellular immune response to HPV type 16 (HPV-16) VLPsin vitro. Peripheral blood mononuclear cells (PBMCs) from healthy donor women were stimulatedin vitrowith HPV-16 VLPs (2.5 μg/ml) in the presence of E2 and P4 administered either alone or in combination; and lymphoproliferation, cytokine production, transcription factor expression, and steroid hormone receptor expression were analyzed. HPV-16 VLPs significantly increased the levels of lymphoproliferation, proinflammatory cytokine (gamma interferon [IFN-γ], interleukin-1β [IL-1β], IL-2, IL-6, IL-8, IL-12p70, IL-17, tumor necrosis factor alpha [TNF-α]) production, anti-inflammatory cytokine (IL-1ra, IL-10) production, and the expression of Erα and Erβ but decreased the levels ofFoxp3expression and production of transforming growth factor β (TGF-β). Exposure of PBMCs to E2 and P4 either alone or in combination significantly decreased the levels of lymphoproliferation and production of proinflammatory cytokines (IFN-γ, IL-12p70, TNF-α) but increased the levels of production of IL-10 and TGF-β and the expression ofFoxp3in response to HPV-16 VLPs. Treatment of cells with biologically relevant concentrations of sex steroid hormones suppressed the inflammatory response and enhanced the regulatory response to HPV-16 VLPs, which may have implications for predicting the long-term efficacy of HPV vaccines, adverse events, and cross-protection among women taking COCs.
Rapid and Direct Quantification of Viable
Candida
Species in Whole Blood by Use of Immunomagnetic Separation and Solid-Phase Cytometry
Authors: Vanhee Lies M. E. , Meersseman Wouter , Lagrou Katrien , Maertens Johan , Nelis Hans J. , Coenye Tom
Published: February 2010

Candida
species are a common source of nosocomial bloodstream infections in critically ill patients. The sensitivity of the traditional diagnostic procedure based on blood culture is variable, and it usually takes 2 to 4 days before growth of
Candida
species is detected. We developed a 4-h method for the quantification of
Candida
species in blood, combining immunomagnetic separation (IMS) with solid-phase cytometry (SPC) using viability labeling. Additionally,
Candida albicans
cells could be identified in real time by using fluorescent
in situ
hybridization. By analysis of spiked blood samples, our method was shown to be sensitive and specific, with a low detection limit (1 cell/ml of blood). In a proof-of-concept study, we applied the IMS/SPC method to 16 clinical samples and compared it to traditional blood culture. Our method proved more sensitive than culture (seven samples were positive with IMS/SPC but negative with blood culture), and identification results were in agreement. The IMS/SPC data also suggest that mixed infections might occur frequently, as
C. albicans
and at least one other
Candida
species were found in five samples. Additionally, in two cases, high numbers of cells (175 to 480 cells/ml of blood) were associated with an endovascular source of infection.
Full-Genome Sequence Analysis of a Multirecombinant Echovirus 3 Strain Isolated from Sewage in Greece
Authors: Kyriakopoulou Zaharoula , Dedepsidis Evaggelos , Pliaka Vaia , Tsakogiannis Dimitris , Pratti Anastassia , Levidiotou-Stefanou Stamatina , Markoulatos Panayotis
Published: February 2010

An echovirus 3 (Echo3) strain (strain LR31G7) was isolated from a sewage treatment plant in Greece in 2005. Full-genome molecular, phylogenetic, and SimPlot analyses were conducted in order to reveal the evolutionary pathways of the isolate. Nucleotide and phylogenetic analyses of part of the VP1 genomic region revealed that the isolated strain correlates with Echo3 strains isolated during the same year in France and Japan, implying that the same virus circulated in Europe and Asia. LR31G7 was found to be a recombinant that shares the 3′ part of its genome with an Echo25 strain isolated from asymptomatic infants in Norway in 2003. Nucleotide and SimPlot analyses of the VP1-2A junction, where the recombination was located, revealed the exact recombination breakpoint (nucleotides 3357 to 3364). Moreover, there is evidence that recombination events had occurred in 3B-3D region in the evolutionary history of the isolate. Our study indicates that recombination events play major roles in enterovirus evolution and that the circulation of multirecombinant strains with unknown properties could be potentially dangerous for public health.
Scrub Typhus in Previously Unrecognized Areas of Endemicity in China
Authors: Zhang Shouyin , Song Hongbin , Liu Yan , Li Qun , Wang Yong , Wu Jiabin , Wan Junfeng , Li Guolan , Yu Changjun , Li Xiuyong , Yin Wenwu , Xu Zhen , Liu Bo , Zhang Qian , Wan Kanglin , Li Guichang , Fu Xiuping , Zhang Jingshan , He Jinrong , Hai Rong , Yu Dongzheng , Walker David H. , Xu Jianguo , Yu Xue-Jie
Published: February 2010

Scrub typhus, caused by
Orientia tsutsugamushi
, has emerged recently in areas of northern China where the disease had not been known to exist. We analyzed epidemiological, clinical, and laboratory data for 104 patients who were admitted to a hospital in Fuyang City between 26 September and 1 November 2008. We showed that the major clinical manifestations of the patients were fever (100%), headache (82%), myalgias (77%), eschar (67%), rash (52%), and unusual facial flushing (62%). Among the 104 patients, the sera of 98% contained IgM antibodies to
O. tsutsugamushi
detected by indirect immunofluorescence assays (IFA), and DNA of the
O. tsutsugamushi
56-kDa gene was amplified by PCR from the blood of 36 patients. We conclude that 104 patients were infected with scrub typhus in Fuyang City, Anhui Province. Our study indicates that physicians need to consider the diagnosis of scrub typhus for febrile patients living in northern China, where scrub typhus had not been considered to exist in the past.
Prompt and Successful Toxin-Targeting Treatment of Three Patients with Necrotizing Pneumonia Due to
Staphylococcus aureus
Strains Carrying the Panton-Valentine Leukocidin Genes
Authors: Rouzic Nicolas , Janvier Frédéric , Libert Nicolas , Javouhey Etienne , Lina Gerard , Nizou Jacques-Yves , Pasquier Pierre , Stamm Didier , Brinquin Louis , Pelletier Christophe , Vandenesch François , Floret Daniel , Etienne Jerome , Gillet Yves
Published: February 2010

Three patients with extensive necrotizing pneumonia due to Panton-Valentine leukocidin-positive
Staphylococcus aureus
strains and with aggravating factors (leukopenia count of less than 3 × 10
9
/liter in all three cases and hemoptysis in two cases) were successfully treated with toxin-suppressing agents introduced rapidly after hospital admission.
Antifungal Susceptibility Testing of
Candida
Isolates from the Candida Surveillance Study
Authors: Lyon G. Marshall , Karatela Sulaiman , Sunay Susan , Adiri Yaffa
Published: February 2010

Candida
species are a common cause of nosocomial bloodstream infections. Recent surveillance has shown an increase in the relative proportion of infections caused by
Candida glabrata
, which has reduced susceptibility to fluconazole. We undertook sentinel surveillance with antifungal susceptibility testing to monitor the trends in the proportions of various
Candida
species causing invasive disease. Forty-one institutions participated in the Candida Surveillance Study. All isolates were submitted to a central laboratory for identification and susceptibility testing. Susceptibility testing was performed in compliance with CLSI guidelines using a custom, broth dilution, microtiter system. There were 5,900 isolates submitted for identification and antifungal susceptibility testing. The distribution of species was as follows:
C. albicans
, 2,567 (43.5%) isolates;
C. glabrata
, 1,464 (24.8%) isolates;
C. parapsilosis
, 1,048 (17.8%) isolates;
C. tropicalis
, 527 (8.9%) isolates;
C. krusei
, 109 (1.9%) isolates;
C. lusitaniae
, 76 (1.3%) isolates; and other
Candida
species, 109 (1.9%) isolates. Resistance to fluconazole occurred in 1.2% of
C. albicans
isolates, 5.9% of
C. glabrata
isolates, 0.3% of
C. parapsilosis
isolates, and 0.4% of
C. tropicalis
isolates. Resistance to fluconazole was highly predictive of resistance to voriconazole. Resistance to echinocandins was rarely found, occurring in only 0.2% of all isolates. The rate of fluconazole susceptibility increased significantly from 87.5% in 2005 to 97.4% in 2007. The proportion of cases of disease caused by various
Candida
species did not change appreciably between 2004 and 2007, and the rate of antifungal susceptibility was high.
A Chimeric Alphavirus Replicon Particle Vaccine Expressing the Hemagglutinin and Fusion Proteins Protects Juvenile and Infant Rhesus Macaques from Measles
Authors: Pan Chien-Hsiung , Greer Catherine E. , Hauer Debra , Legg Harold S. , Lee Eun-Young , Bergen M. Jeff , Lau Brandyn , Adams Robert J. , Polo John M. , Griffin Diane E.
Published: February 2010

Measles remains a major cause of child mortality, in part due to an inability to vaccinate young infants with the current live attenuated virus vaccine (LAV). To explore new approaches to infant vaccination, chimeric Venezuelan equine encephalitis/Sindbis virus (VEE/SIN) replicon particles were used to express the hemagglutinin (H) and fusion (F) proteins of measles virus (MV). Juvenile rhesus macaques vaccinated intradermally with a single dose of VEE/SIN expressing H or H and F proteins (VEE/SIN-H or VEE/SIN-H+F, respectively) developed high titers of MV-specific neutralizing antibody and gamma-interferon (IFN-γ)-producing T cells. Infant macaques vaccinated with two doses of VEE/SIN-H+F also developed neutralizing antibody and IFN-γ-producing T cells. Control animals were vaccinated with LAV or with a formalin-inactivated measles vaccine (FIMV). Neutralizing antibody remained above the protective level for more than 1 year after vaccination with VEE/SIN-H, VEE/SIN-H+F, or LAV. When challenged with wild-type MV 12 to 17 months after vaccination, all vaccinated juvenile and infant monkeys vaccinated with VEE/SIN-H, VEE/SIN-H+F, and LAV were protected from rash and viremia, while FIMV-vaccinated monkeys were not. Antibody was boosted by challenge in all groups. T-cell responses to challenge were biphasic, with peaks at 7 to 25 days and at 90 to 110 days in all groups, except for the LAV group. Recrudescent T-cell activity coincided with the presence of MV RNA in peripheral blood mononuclear cells. We conclude that VEE/SIN expressing H or H and F induces durable immune responses that protect from measles and offers a promising new approach for measles vaccination. The viral and immunological factors associated with long-term control of MV replication require further investigation.
Pathogenesis of a Model Gammaherpesvirus in a Natural Host
Authors: Hughes David J. , Kipar Anja , Sample Jeffery T. , Stewart James P.
Published: February 2010

Murine gammaherpesvirus 68 (MHV-68) infection of laboratory mice (
Mus musculus
) is an established model of gammaherpesvirus pathogenesis. The fact that
M. musculus
is not a host in the wild prompted us to reassess MHV-68 infection in wood mice (
Apodemus sylvaticus
), a natural host. Here, we report significant differences in MHV-68 infection in the two species: (i) following intranasal inoculation, MHV-68 replicated in the lungs of wood mice to levels approximately 3 log units lower than in BALB/c mice; (ii) in BALB/c mice, virus replication in alveolar epithelial cells was accompanied by a diffuse, T-cell-dominated interstitial pneumonitis, whereas in wood mice it was restricted to focal granulomatous infiltrations; (iii) within wood mice, latently infected lymphocytes were abundant in inducible bronchus-associated lymphoid tissue that was not apparent in BALB/c mice; (iv) splenic latency was established in both species, but well-delineated secondary follicles with germinal centers were present in wood mice, while only poorly delineated follicles were seen in BALB/c mice; and, perhaps as a consequence, (v) production of neutralizing antibody was significantly higher in wood mice. These differences highlight the value of this animal model in the study of MHV-68 pathogenesis.
Introduction of Virulence Markers in PB2 of Pandemic Swine-Origin Influenza Virus Does Not Result in Enhanced Virulence or Transmission
Authors: Herfst Sander , Chutinimitkul Salin , Ye Jianqiang , de Wit Emmie , Munster Vincent J. , Schrauwen Eefje J. A. , Bestebroer Theo M. , Jonges Marcel , Meijer Adam , Koopmans Marion , Rimmelzwaan Guus F. , Osterhaus Albert D. M. E. , Perez Daniel R. , Fouchier Ron A. M.
Published: February 2010

In the first 6 months of the H1N1 swine-origin influenza virus (S-OIV) pandemic, the vast majority of infections were relatively mild. It has been postulated that mutations in the viral genome could result in more virulent viruses, leading to a more severe pandemic. Mutations E627K and D701N in the PB2 protein have previously been identified as determinants of avian and pandemic influenza virus virulence in mammals. These mutations were absent in S-OIVs detected early in the 2009 pandemic. Here, using reverse genetics, mutations E627K, D701N, and E677G were introduced into the prototype S-OIV A/Netherlands/602/2009, and their effects on virus replication, virulence, and transmission were investigated. Mutations E627K and D701N caused increased reporter gene expression driven by the S-OIV polymerase complex. None of the three mutations affected virus replication
in vitro
. The mutations had no major impact on virus replication in the respiratory tracts of mice and ferrets or on pathogenesis. All three mutant viruses were transmitted via aerosols or respiratory droplets in ferrets. Thus, the impact of key known virulence markers in PB2 in the context of current S-OIVs was surprisingly small. This study does not exclude the possibility of emergence of S-OIVs with other virulence-associated mutations in the future. We conclude that surveillance studies aimed at detecting S-OIVs with increased virulence or transmission should not rely solely on virulence markers identified in the past but should include detailed characterization of virus phenotypes, guided by genetic signatures of viruses detected in severe cases of disease in humans.
Bimolecular Complementation Defines Functional Regions of Herpes Simplex Virus gB That Are Involved with gH/gL as a Necessary Step Leading to Cell Fusion
Authors: Atanasiu Doina , Whitbeck J. Charles , de Leon Manuel Ponce , Lou Huan , Hannah Brian P. , Cohen Gary H. , Eisenberg Roselyn J.
Published: February 2010

Herpes simplex virus (HSV) entry into cells requires four membrane glycoproteins: gD is the receptor binding protein, and gB and gH/gL constitute the core fusion machinery. Crystal structures of gD and its receptors have provided a basis for understanding the initial triggering steps, but how the core fusion proteins function remains unknown. The gB crystal structure shows that it is a class III fusion protein, yet unlike other class members, gB itself does not cause fusion. Bimolecular complementation (BiMC) studies have shown that gD-receptor binding triggers an interaction between gB and gH/gL and concurrently triggers fusion. Left unanswered was whether BiMC led to fusion or was a by-product of it. We used gB monoclonal antibodies (MAbs) to block different aspects of these events. Non-virus-neutralizing MAbs to gB failed to block BiMC or fusion. In contrast, gB MAbs that neutralize virus blocked fusion. These MAbs map to three functional regions (FR) of gB. MAbs to FR1, which contains the fusion loops, and FR2 blocked both BiMC and fusion. In contrast, MAbs to FR3, a region involved in receptor binding, blocked fusion but not BiMC. Thus, FR3 MAbs separate the BiMC interaction from fusion, suggesting that BiMC occurs prior to fusion. When substituted for wild-type (wt) gB, fusion loop mutants blocked fusion and BiMC, suggesting that loop insertion precedes BiMC. Thus, we postulate that each of the gB FRs are involved in different aspects of the path leading to fusion. Upon triggering by gD, gB fusion loops are inserted into target lipid membranes. gB then interacts with gH/gL, and this interaction is eventually followed by fusion.
Voltammetric studies of the Co(II)-tris(hydroxymethyl)aminomethane and sodium perborate volumetric catalytic system
Authors: Zarębski Jerzy , Bobrowski Andrzej , Królicka Agnieszka , Putek Maria
Published: February 2010

It has been shown that in the tris(hydroxymethyl)aminomethane (THAM)/HCl buffer, Co(II) ions catalyze the oxidation of THAM by sodium perborate. The reaction occurs at boiling temperature, and the product of the catalytic THAM oxidation, tris(hydroxymethyl)nitrosomethane, gives a well-defined quasireversible cathodic wave preceding that of the Co(II) ions by about 160 mV. The voltammetric responses of this product are proportional to the amount of sodium perborate and to the concentration of Co(II) ions. In the volumetric catalytic system of Co(II) ions/THAM/sodium perborate, the sensitivity of the determination of Co(II) is increased by one to two orders of magnitude, depending on the voltammetric technique used. Prior to the detection of tris(hydroxymethyl)nitrosomethane, EDTA was added to the solution to form voltammetrically inactive complexes with Co(II) and other interfering ions. Therefore, this method may be applied for the determination of Co(II) ions at low concentrations in the presence of a large excess of interfering ions, in particular Ni(II) and Zn(II).
Polarography in initial stages of elucidation of organic electrode processes
Authors: Zuman Petr
Published: February 2010

To develop a reliable electroanalytical method, it is essential to understand – at least in principle – the nature of physical and chemical processes involved. DC polarography is a useful tool in initial stages of elucidation of processes involving reductions and oxidations of organic compounds in aqueous solutions. Main information to be obtained involves: the number of reduction and oxidation steps, the number of electrons transferred in each step, the nature of the transport of electroactive species, the roles of fast, slower and slow chemical reactions (such as proton transfers or hydration–dehydration equilibria), in particular those preceding electron transfer and the structure of the electrolysis product. The used tools are: (i) Measurements of the limiting current and half-wave potentials and their dependence on composition of the supporting electrolyte; (ii) dependences on drop-time and scan-rate; (iii) product identification; (iv) comparison with structurally related compounds, experimentally and from literature. Examples of reductions of the following bonds are given. Single bonds: C–X (X = halides, OR, OH, NH2, SR), N–Y (Y = O, N, S), O–O, N–N, S–S. Double bonds: C=C, C=N, C=S, N=N, and also triple bonds: C≡C, C≡N. Examples of oxidations are those of phenols and of enediols. Anodic waves due to mercury salt formations are observed for thiols, urea and thiourea derivatives (barbiturates, thiobarbiturates), and dithiocarbamates. References are restricted to our work.
From DC polarographic presodium wave of proteins to electrochemistry of biomacromolecules
Authors: Paleček Emil , Heyrovský Michael , Janík Bořivoj , Kaláb Dušan , Pechan Zdeněk
Published: February 2010

History of electrochemistry of proteins and nucleic acids is briefly reviewed. The ability of proteins to catalyze hydrogen evolution at Hg electrodes was discovered almost 80 years ago in J. Heyrovský’s laboratory. This phenomenon was not sufficiently appreciated for several decades. Recently it has been shown that using constant current chronopotentiometric stripping (CPS) with hanging mercury drop, solid amalgam or Hg-film electrodes the CPS peak H is obtained with nanomolar concentrations of peptides and proteins. This peak is derived from the presodium wave but it has some new properties useful in protein research. It is sensitive to changes in protein structures and to protein redox states, representing a new tool for protein analysis applicable in biomedicine. Electroactivity of nucleic acids was discovered about 50 years ago. Electrochemistry of DNA and RNA is now a booming field because of its potential use in sensors for DNA hybridization and DNA damage. Quite recently it has been shown that electrochemistry can be applied also in polysaccharide analysis. A review with 99 references.
Assessment of parental decision-making in neonatal cardiac research: a pilot study
Authors: Nathan Aruna T , Hoehn K Sarah , Ittenbach Richard F , Gaynor J William , Nicolson Susan , Wernovsky Gil , Nelson Robert M
Published: February 2010

Objective

To assess parental permission for a neonate's research participation using the MacArthur competence assessment tool for clinical research (MacCAT-CR), specifically testing the components of understanding, appreciation, reasoning and choice.

Study Design

Quantitative interviews using study-specific MacCAT-CR tools.

Hypothesis

Parents of critically ill newborns would produce comparable MacCAT-CR scores to healthy adult controls despite the emotional stress of an infant with critical heart disease or the urgency of surgery. Parents of infants diagnosed prenatally would have higher MacCAT-CR scores than parents of infants diagnosed postnatally. There would be no difference in MacCAT-CR scores between parents with respect to gender or whether they did or did not permit research participation.

Participants

Parents of neonates undergoing cardiac surgery who had made decisions about research participation before their neonate's surgery.

Methods

The MacCAT-CR.

Results

35 parents (18 mothers; 17 fathers) of 24 neonates completed 55 interviews for one or more of three studies. Total scores: magnetic resonance imaging (mean 36.6, SD 7.71), genetics (mean 38.8, SD 3.44), heart rate variability (mean 37.7, SD 3.30). Parents generally scored higher than published subject populations and were comparable to published control populations with some exceptions.

Conclusions

The MacCAT-CR can be used to assess parental permission for neonatal research participation. Despite the stress of a critically ill neonate requiring surgery, parents were able to understand study-specific information and make informed decisions to permit their neonate's participation.
The use of placebo in a trial of rectal artesunate as initial treatment for severe malaria patients en route to referral clinics: ethical issues
Authors: Kitua Andrew , Folb Peter , Warsame Marian , Binka Fred , Faiz Abul , Ribeiro Isabela , Peto Tom , Gyapong John , Yunus Emran Bin , Rahman Ridwan , Baiden Frank , Clerk Christine , Mrango Zakayo , Makasi Charles , Kimbute Omari , Hossain Amir , Samad Rasheda , Gomes Melba
Published: February 2010

Placebo-controlled trials are controversial when individuals might be denied existing beneficial medical interventions. In the case of malaria, most patients die in rural villages without healthcare facilities. An artesunate suppository that can be given by minimally skilled persons might be of value when patients suddenly become too ill for oral treatment but are several hours from a facility that can give injectable treatment for severe disease. In such situations, by default, no treatment is (or can be) given until the patient reaches a facility, making the placebo control design clinically relevant; alternative bioequivalence designs at the facility would misrepresent reality and risk incorrect conclusions. We describe the ethical issues underpinning a placebo-controlled trial in severe malaria. To protect patients and minimise risk, all patients were referred immediately to hospital so that each had a higher chance of prompt treatment through participation. There was no difference between artesunate and placebo in patients who reached clinic rapidly; among those who could not, a single artesunate suppository significantly reduced death or permanent disability, a finding of direct and indirect benefit to patients in participating villages and elsewhere.
Hidden risks associated with clinical trials in developing countries
Authors: Lorenzo Cláudio , Garrafa Volnei , Solbakk Jan Helge , Vidal Susana
Published: February 2010

The academic literature in research ethics has been marked in the past decade by a much broader focus on the need for the protection of developing communities subjected to international clinical trials. Because of the proximity of the revision of the Declaration of Helsinki, completed in October 2008, most papers have addressed the issue of a double standard of care following the use of placebo. However, other no less important issues, such as interactions between the lifestyles structures of low-income communities and the efficiency of risk-minimising procedures also deserve attention. The purpose of this paper is to discuss forms of uncertainty involved in clinical trials in poor and low-income countries that are not addressed by conventional methods of risk assessment. Furthermore, the increase in size of risks that are identified by conventional assessment methods will be addressed. Besides, the difficulty in properly applying risk-minimising procedures will be discussed. Finally, this paper proposes the involvement of research ethics committees in the risk evaluation process and the establishment of national ethics evaluation systems.
Attributes of a good physician: what are the opinions of first-year medical students?: Table 1
Authors: Sehiralti Mine , Akpinar Aslihan , Ersoy Nermin
Published: February 2010

Background

Undergraduate medical education is beginning to concern itself with educating students about professional attributes as well as about clinical knowledge and skills. Defining these characteristics, and in particular seeking the help of the students themselves to define them, can be a useful starting point when considering how to incorporate aspects of professional behaviour into the medical curricula.

Method

This study explores the views of first-year medical students at Kocaeli University Faculty of Medicine in the 2007–8 academic year. The students were asked the open-ended question: ‘What, in your opinion, are the attributes a good physician should have?’ Four topics were defined by researchers based on the undergraduate and graduate education projects. The attributes expressed by the students were evaluated by the researchers according to these topics and compared with the topics covered in the undergraduate and graduate education projects.

Results

A total of 127 students responded, and between them suggested 756 attributes. The majority of these attributes (54.6%) were concerned with interpersonal relations and communication, whereas the category representing the fewest attributes (12.3%) was that involving scientific knowledge and medical practice. In general, students' perception corresponded to the concept of the ‘competent physician’ as described in the professionalism projects, but attributes reflecting their world-view were also expressed.

Conclusion

Experience suggests that the active participation of students in determining which attributes are necessary for a good physician is a positive way of ensuring they embrace the importance of such qualities and attributes in themselves.
Drusen and the misleading optic disc
Authors: Arbabi Esmaeil M , Fearnley Thomas E , Carrim Zia I
Published: February 2010

Optic disc drusen are acellular calcified deposits occurring in small optic discs. They have a prevalence of up to approximately 2% and are bilateral in 75% of cases. Their size and fundosc pic visibility increase with age, and they are commonly responsible for the misdiagnosis of papilloedema by the unwary. Although largely asymptomatic, they can be associated with vascular problems affecting the optic nerve. Ocular ultrasonography is the most sensitive method for their detection. This article highlights their commonly encountered clinical presentations and the practical aspects of diagnosis and management.
Work-relatedHelicobacter pyloriinfection among sewage workers in municipal wastewater treatment plants in Belgium
Authors: Van Hooste Wim , Charlier Anne-Marie , Rotsaert Paul , Bulterys Simon , Moens Guido , van Sprundel Marc , De Schryver Antoon
Published: February 2010

Introduction

Most studies among sewage workers of wastewater treatment plants (WWTPs) have found a higher prevalence of gastrointestinal symptoms than among non-sewage exposed workers. Waterborne transmission ofHelicobacter pylori(H pylori) has been hypothesised, as the bacteria can survive into an aqueous environment and has been detected in sewage. A health and hygiene questionnaire has demonstrated a higher prevalence of peptic ulcers among Belgian WWTP operators and maintenance workers than among non-sewage exposed colleagues.

Objectives

To assess the seroprevalence ofH pyloriinfection in Belgian sewage workers at municipal WWTPs, and to determine whether sewage exposure is an important risk factor for acquisition ofH pyloriand the possible association with gastrointestinal symptoms.

Methods

A seroprevalence study ofH pyloriantibodies was conducted among 317 WWTP employees (operators, maintenance workers, laboratory personnel, other job). Information about demographic variables, possibleH pyloririsk factors, working history, and history of current gastrointestinal symptoms during last 3 months was obtained by a questionnaire. The presence ofH pyloriIgG was investigated with an ELISA. The results were compared with those of 250 employees of a pharmaceutical company (operators, maintenance workers, laboratory personnel).

Results

The prevalence ofH pyloriIgG antibodies among sewage workers was 16.7% (95% CI 12.6 to 20.8%) compared to 13.6% (95% CI 9.4 to 17.8%) among the control group. In a logistic regression model with controlling for age and educational levels, OR study/control group was 1.02 (95% CI 0.58 to 1.80 with p=0.93). No significant associations were found between theH pyloristatus and gastrointestinal symptoms, occupational exposures in different tasks, nor with hygienic practices.

Conclusions

Our results do not suggest thatH pyloriinfection is a probable cause of part of gastrointestinal symptoms among Flemish municipal sewage workers of WWTPs.
ENHANCING THE SYNCHRONIZABILITY OF SCALE-FREE NETWORKS BY ADDING EDGES
Authors: WANG SHENG-JUN , WU ZHI-XI , DONG HAI-RONG , CHEN GUANRONG
Published: February 2010

To efficiently enhance the synchronizability of a scale-free network by adding some edges, we numerically study the effect of edge-adding on the spectrum of the network Laplacian matrix. Based on the relation between the largest eigenvalue of the Laplacian matrix and the largest degree of the scale-free network, we show that adding a new edge to the node of largest degree will generally weaken the synchronizability of a scale-free network. We consequently propose a method to effectively enhance the network synchronizability by attaching the new edge to a node whose nearest-neighbors have small degrees. The effect of the new method is analyzed and demonstrated with comparisons.
NEWS FRAMING OF POPULATION AND FAMILY PLANNING ISSUES VIA SYNTACTIC NETWORK ANALYSIS
Authors: LEGARA ERIKA , MONTEROLA CHRISTOPHER , DAVID CLARISSA , MAE ATUN JENNA
Published: February 2010

Contentious political debates regarding the issues on population and family planning have been perennial over the past four decades especially in developing countries. While its prominence in the public agenda varies depending on other national issues vying for public attention, its presence in policy and political agendas is constant. Here, a computational approach to framing analysis is developed that examines the pattern of media coverage on the population issue in the Philippines. The content of 146 articles sampled from 1988 to 2007 in Manila Bulletin (one of the leading newspapers in the Philippines) is analyzed by creating a syntactic network of concept co-occurrences. The topological properties of the network indicates that the discussion of an article revolves around few central ideas. Moreover, cluster analysis of the network suggests three well-defined frame themes, namely:

(1) Development Frame;

(2) Maternal Health Frame; and

(3) Framing by the Catholic Church.

Our results support the thesis that the inability to fruitfully discuss points of contention to reach agreement about suitable population policies in the Philippines is due to the mismatched frames within which it is discussed.
MUTUAL SELECTION IN NETWORK EVOLUTION: THE ROLE OF THE INTRINSIC FITNESS
Authors: XU XIN-JIAN , ZHANG LIU-MING , ZHANG LI-JIE
Published: February 2010

We propose a new mechanism leading to scale-free networks which is based on the presence of an intrinsic character of a vertex called fitness. In our model, a vertex i is assigned a fitness xi, drawn from a given probability distribution function f(x). During network evolution, with rate p we add a vertex j of fitness xj and connect to an existing vertex i of fitness xi selected preferentially to a linking probability function g(xi, xj) which depends on the fitnesses of the two vertices involved and, with rate 1 - p we create an edge between two already existed vertices with fitnesses xi and xj, with a probability also preferential to the connection function g(xi, xj). For the proper choice of g, the resulting networks have generalized power-laws, irrespective of the fitness distribution of vertices.