bluuebunny/crossref_metadata_2025 huggingface dataset:
Melatonin location in egg phosphatidylcholine liposomes: possible relation to its antioxidant mechanisms
Authors: De Lima Vânia Rodrigues , Caro Miguel Soriano Balparda , Tavares Maria Inês Bruno , Creczynski‐Pasa Tânia Beatriz
Published: July 2007

Abstract:  Although it is known that the antioxidant properties of melatonin can be modulated by its effect on membrane fluidity, there are few studies on this subject reported in the literature and they are controversial. In this study, viscosimetry and nuclear magnetic resonance (NMR) techniques were used to determine melatonin’s effect and location on egg phosphatidylcholine bilayers mobility. Melatonin decreases the dynamic viscosity of the lipid dispersion. 31P‐NMR line width analysis indicated that melatonin induces a slight but uniform restriction of the lipid motional freedom in the polar head. However, melatonin changes in choline 13C dynamics was only observed through chemical shift analysis. On the other hand, melatonin can induce an increase in the lipid nonpolar chain mobility, as observed by 13C and 1H relaxation time analysis. These results suggest the interfacial location of melatonin in the membrane. Additionally, the results of the analysis of the lipid 1H‐fitted exponential relaxation times suggest that melatonin promotes a molecular rearrangement of the bilayers. The melatonin effect and location in the lipid membrane may explain its antioxidant properties against lipid peroxidation induced by reactive species.
Prevention by melatonin of hepatocarcinogenesis in rats injected with N‐nitrosodiethylamine
Authors: Subramanian Perumal , Mirunalini Shankaran , Dakshayani Kadiyala Babu , Pandi‐Perumal Seithikurippu R. , Trakht Ilya , Cardinali Daniel P.
Published: July 2007

Abstract:  N‐nitrosodiethylamine (NDEA) is a potent carcinogenic agent that induces liver cancer. To evaluate the chemopreventive function of melatonin in this experimental model, Wistar male rats received a single i.p. injection of NDEA or vehicle followed by weekly s.c. injections of carbon tetrachloride or vehicle for 6 weeks. Melatonin (5 mg/kg body weight) or its vehicle (0.5 mL saline) was given i.p. on a daily basis 2 hr before lights off for 20 wk. At the end of this period the rats were killed and liver and blood samples were taken for histological and biochemical studies. As markers for liver function, the activity of aspartate transaminase (AST) and alanine transaminase (ALT) and the levels of α‐fetoprotein were measured in serum. To assess lipid peroxidation and the antioxidant status in liver and blood, the levels of thiobarbituric acid reactive substances (TBARS) and of reduced glutathione (GSH) were measured. The activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S‐transferase (GST) was assessed in liver and erythrocyte fraction of NDEA‐treated rats. NDEA administration inhibited body weight, macro‐ and microscopically detectable liver tumors and increased levels of plasma AST, ALT and α‐fetoprotein. NDEA treatment decreased liver TBARS levels and CAT and SOD activities and increased liver GSH levels and GST and GPx activities. Plasma TBARS were augmented, while plasma GSH levels and the activities of erythrocyte CAT, SOD, GST and GPx decreased, in NDEA‐treated rats. Melatonin administration significantly curtailed tumor development and counteracted all the biochemical effects.
Preoperative intravenous iron administration corrects anemia and reduces transfusion requirement in women undergoing abdominal hysterectomy
Authors: DIEZ‐LOBO ANA I. , FISAC‐MARTÍN MARÍA P. , BERMEJO‐AYCAR IGNACIO , MUÑOZ MANUEL
Published: July 2007

We prospectively investigated the utility of preoperative intravenous (IV) iron treatment to increase hemoglobin (Hb) levels and reduce the need for transfusion in women with iron deficiency anemia (IDA) or iron deficiency (ID) scheduled for elective abdominal hysterectomy. Seventy‐five women with ID or IDA were enrolled in the study. Women having their surgical procedure at least 1 month after preoperative assessment received IV iron sucrose during 2–4 weeks (IV iron group, n = 31). Women having their surgical procedure a few days after preoperative assessment did not receive IV iron (control group, n = 44). At baseline, there were no differences between the two groups in terms of weight or age, prevalence of anemia, Hb levels or iron laboratory parameters. IV iron sucrose (760 ± 290 mg) increased preoperative Hb (ΔHb: 2.2 ± 1.2 g/dL; P < 0.001) and reduced postoperative transfusion rates when compared with the control group (32%vs. 0%, respectively; P < 0.001). In addition, fewer women from the IV iron group were anemic on postoperative day 21 (23%vs. 68%, respectively; P < 0.01). No life‐threatening iron sucrose adverse effect was observed. Because of the rapid increase in Hb levels, IV iron sucrose administration seems to be an effective approach for treating preoperative anemia and reducing transfusion rates in this female population.
Development of GaSb Photoreceiver Arrays for Solar Thermophotovoltaic Systems
Authors: Martín Diego , Algora Carlos , Corregidor Victoria , Datas Alejandro
Published: July 2007

In comparison to conventional solar photovoltaics, where sun radiation is converted into electricity directly by solar cells, solar thermophotovoltaic (STPV) conversion has some specific advantages. These advantages come from the fact that in thermophotovoltaics the photon radiator is always inside the conversion system and near the photovoltaic cells. For these reasons we are developing small prototypes with sun heated emitters and photoreceiver arrays to be installed inside complete STPV systems. In order to achieve these complete STPV systems, the first step is to determine the optimum way of packaging the TPV cells into STPV arrays, choosing the best series/parallel configurations depending on the TPV cell band gap, the size of arrays, and the materials. This is the goal of this paper. To carry out the calculations, 18 and 24 cell arrays have been connected following different series and parallel configurations, using the PSPICE commercial circuit-simulation software. Each TPV cell is simulated as a block consisting of the well-known photogenerated current source, two dark diodes of ideality factors equal to one and two, and two resistances, one in parallel and the other in series. As a result, recommendations about the size and front grid design of the GaSb cells are obtained. When the optimally designed cells are connected to be included in two specific systems, recommendations about the best parallel/series connection are achieved. Evaluation on the performance of the arrays at nonuniform illumination is also carried out. The first photoreceiver arrays are being constructed and implemented in real STPV systems following these recommendations.
GaSb

Crystals and Wafers for Photovoltaic Devices
Authors: Luca S. , Santailler J. L. , Rothman J. , Belle J. P. , Calvat C. , Basset G. , Passero A. , Khvostikov V. P. , Potapovich N. S. , Levin R. V.
Published: July 2007

GaSb material presents interesting properties for single junction thermophotovoltaic (TPV) devices. GaSb:Te single crystal grown with Czochralski (Cz) or modified Czochralski (Mo-Cz) methods are presented and the problem of Te homogeneity discussed. As the carrier mobility is one of the key points for the bulk crystal, Hall measurements are carried out. We present here some complementary developments based on the material processing point of view: the bulk crystal growth, the wafer preparation, and the wafer etching. Subsequent steps after these are related to the p∕n or n∕p junction elaboration. Some results obtained for different thin-layer elaboration approaches are presented. So from the simple vapor phase diffusion process or the liquid phase epitaxy process up to the metal organic chemical vapor deposition process we report some material specificity.
Solar Thermophotovoltaic Converters Based on Tungsten Emitters
Authors: Andreev V. M. , Vlasov A. S. , Khvostikov V. P. , Khvostikova O. A. , Gazaryan P. Y. , Sorokina S. V. , Sadchikov N. A.
Published: July 2007

Results of a solar thermophotovoltaic (STPV) system study are reported. Modeling of the STPV module performance and the analysis of various parameters influencing the system are presented. The ways for the STPV system efficiency to increase and their magnitude are considered such as: improvement of the emitter radiation selectivity and application of selective filters for better matching the emitter radiation spectrum and cell photoresponse; application of the cells with a back side reflector for recycling the sub-band gap photons; and development of low-band gap tandem TPV cells for better utilization of the radiation spectrum. Sunlight concentrator and STPV modules were designed, fabricated, and tested under indoor and outdoor conditions. A cost-effective sunlight concentrator with Fresnel lens was developed as a primary concentrator and a secondary quartz meniscus lens ensured the high concentration ratio of ∼4000×, which is necessary for achieving the high efficiency of the concentrator–emitter system owing to trap escaping radiation. Several types of STPV modules have been developed and tested under concentrated sunlight. Photocurrent density of 4.5A∕cm2 was registered in a photoreceiver based on 1×1cm2GaSb cells under a solar powered tungsten emitter.
Triple-Junction III–V Based Concentrator Solar Cells: Perspectives and Challenges
Authors: Baur C. , Bett A. W. , Dimroth F. , Siefer G. , Meusel M. , Bensch W. , Köstler W. , Strobl G.
Published: July 2007

This paper gives a review of the work performed in the framework of the EC-funded project FULLSPECTRUM aiming for higher photovoltaic (PV) conversion efficiencies by investigating GaInP∕GaInAs∕Ge triple-junction concentrator solar cells. Lattice mismatched structures reached efficiencies beyond 35% at 600 sun concentration level. These cells are now ready to enter the terrestrial PV market. The perspectives and challenges associated with the market introduction of these cells are addressed. Specifically issues of reliability and on-wafer characterization are discussed. A new characterization tool MAPCON was developed and is presented.
Efficiency Enhancement of Solar Cells by Application of a Polymer Coating Containing a Luminescent Dye
Authors: Slooff L. H. , Kinderman R. , Burgers A. R. , Bakker N. J. , van Roosmalen J. A. M. , Büchtemann A. , Danz R. , Schleusener M.
Published: July 2007

One of the major loss mechanisms in state of the art photovoltaic cells is spectral loss resulting from inefficient use of ultraviolet photons and the lack of absorption of infrared photons by the solar cell. For a Si solar cell, e.g., spectral losses alone result in over 55% loss of the energy of the solar spectrum. Converting the spectrum of the incoming light such that it has a better match with the absorption spectrum of the solar cell can reduce spectral losses, especially in the case of a small absorption band, such as for dye sensitized solar cells and polymer solar cells. In this paper it is shown that the ultraviolet response of a multicrystalline silicon solar cell and polymer solar cell can be enhanced by application of a polymer coating doped with a luminescent dye. An increase in the power conversion efficiency is obtained for coatings with luminescent dyes with an absorption onset <450 nm. Coatings with luminescent dyes that absorb at higher wavelengths give rise to lower power conversion efficiencies. When applied to a dye sensitized solar cell, a decrease in the cell performance is observed.
I-V Performance and Stability Study of Dyes for Luminescent Plate Concentrators
Authors: Kinderman R. , Slooff L. H. , Burgers A. R. , Bakker N. J. , Büchtemann A. , Danz R. , van Roosmalen J. A. M.
Published: July 2007

In this paper, both the performance and stability of luminescent flat plate concentrator (LFPC) plates in combination with mc-Si photovoltaic cells are studied. It is shown that the electrical current of a silicon solar cell attached to the luminescent plate is improved by a factor 1.5 using a LFPC containing a single dye. It is also shown that most of the dyes are not stable in the polymer plates that are currently used. Screening of the stability of several other dyes indicates that the stability is strongly dependent on the type of dye and the polymer matrix, e.g., additives or the monomer residues.
Motor Proteins at Work for Nanotechnology
Authors: van den Heuvel Martin G. L. , Dekker Cees
Published: July 2007

The biological cell is equipped with a variety of molecular machines that perform complex mechanical tasks such as cell division or intracellular transport. One can envision employing these biological motors in artificial environments. We review the progress that has been made in using motor proteins for powering or manipulating nanoscale components. In particular, kinesin and myosin biomotors that move along linear biofilaments have been widely explored as active components. Currently realized applications are merely proof-of-principle demonstrations. Yet, the sheer availability of an entire ready-to-use toolbox of nanosized biological motors is a great opportunity that calls for exploration.
Host Immune System Gene Targeting by a Viral miRNA
Authors: Stern-Ginossar Noam , Elefant Naama , Zimmermann Albert , Wolf Dana G. , Saleh Nivin , Biton Moshe , Horwitz Elad , Prokocimer Zafnat , Prichard Mark , Hahn Gabriele , Goldman-Wohl Debra , Greenfield Caryn , Yagel Simcha , Hengel Hartmut , Altuvia Yael , Margalit Hanah , Mandelboim Ofer
Published: July 2007

Virally encoded microRNAs (miRNAs) have recently been discovered in herpesviruses. However, their biological roles are mostly unknown. We developed an algorithm for the prediction of miRNA targets and applied it to human cytomegalovirus miRNAs, resulting in the identification of the major histocompatibility complex class I–related chain B (MICB) gene as a top candidate target of hcmv-miR-UL112. MICB is a stress-induced ligand of the natural killer (NK) cell activating receptor NKG2D and is critical for the NK cell killing of virus-infected cells and tumor cells. We show that hcmv-miR-UL112 specifically down-regulates MICB expression during viral infection, leading to decreased binding of NKG2D and reduced killing by NK cells. Our results reveal a miRNA-based immunoevasion mechanism that appears to be exploited by human cytomegalovirus.
Comment on "Redefining the Age of Clovis: Implications for the Peopling of the Americas"
Authors: Haynes Gary , Anderson David G. , Ferring C. Reid , Fiedel Stuart J. , Grayson Donald K. , Haynes C. Vance , Holliday Vance T. , Huckell Bruce B. , Kornfeld Marcel , Meltzer David J. , Morrow Julie , Surovell Todd , Waguespack Nicole M. , Wigand Peter , Yohe Robert M.
Published: July 2007

Waters and Stafford (Reports, 23 February 2007, p. 1122) provided useful information about the age of some Clovis sites but have not definitively established the temporal span of this cultural complex in the Americas. Only a continuing program of radiometric dating and careful stratigraphic correlations can address the lingering ambiguity about the emergence and spread of Clovis culture.
Brain IRS2 Signaling Coordinates Life Span and Nutrient Homeostasis
Authors: Taguchi Akiko , Wartschow Lynn M. , White Morris F.
Published: July 2007

Reduced insulin-like signaling extends the life span of
Caenorhabditis elegans
and
Drosophila
. Here, we show that, in mice, less insulin receptor substrate–2 (Irs2) signaling throughout the body or just in the brain extended life span up to 18%. At 22 months of age, brain-specific
Irs2
knockout mice were overweight, hyperinsulinemic, and glucose intolerant; however, compared with control mice, they were more active and displayed greater glucose oxidation, and during meals they displayed stable superoxide dismutase–2 concentrations in the hypothalamus. Thus, less Irs2 signaling in aging brains can promote healthy metabolism, attenuate meal-induced oxidative stress, and extend the life span of overweight and insulin-resistant mice.
Queen Pheromone Blocks Aversive Learning in Young Worker Bees
Authors: Vergoz Vanina , Schreurs Haley A. , Mercer Alison R.
Published: July 2007

Queen mandibular pheromone (QMP) has profound effects on dopamine signaling in the brain of young worker honey bees. As dopamine in insects has been strongly implicated in aversive learning, we examined QMP's impact on associative olfactory learning in bees. We found that QMP blocks aversive learning in young workers, but leaves appetitive learning intact. We postulate that QMP's effects on aversive learning enhance the likelihood that young workers remain in close contact with their queen by preventing them from forming an aversion to their mother's pheromone bouquet. The results provide an interesting twist to a story of success and survival.
Tumor Growth Need Not Be Driven by Rare Cancer Stem Cells
Authors: Kelly Priscilla N. , Dakic Aleksandar , Adams Jerry M. , Nutt Stephen L. , Strasser Andreas
Published: July 2007

The cancer stem cell hypothesis postulates that tumor growth is driven by a rare subpopulation of tumor cells. Much of the supporting evidence for this intriguing idea is derived from xenotransplantation experiments in which human leukemia cells are grown in immunocompromised mice. We show that, when lymphomas and leukemias of mouse origin are transplanted into histocompatible mice, a very high frequency (at least 1 in 10) of the tumor cells can seed tumor growth. We suggest that the low frequency of tumor-sustaining cells observed in xenotransplantation studies may reflect the limited ability of human tumor cells to adapt to growth in a foreign (mouse) milieu.
A Late Triassic Dinosauromorph Assemblage from New Mexico and the Rise of Dinosaurs
Authors: Irmis Randall B. , Nesbitt Sterling J. , Padian Kevin , Smith Nathan D. , Turner Alan H. , Woody Daniel , Downs Alex
Published: July 2007

It has generally been thought that the first dinosaurs quickly replaced more archaic Late Triassic faunas, either by outcompeting them or when the more archaic faunas suddenly became extinct. Fossils from the Hayden Quarry, in the Upper Triassic Chinle Formation of New Mexico, and an analysis of other regional Upper Triassic assemblages instead imply that the transition was gradual. Some dinosaur relatives preserved in this Chinle assemblage belong to groups previously known only from the Middle and lowermost Upper Triassic outside North America. Thus, the transition may have extended for 15 to 20 million years and was probably diachronous at different paleolatitudes.
Passage to Global Stem Cells
Authors: Phillips M. Ian
Published: July 2007

Cell of Cells The Global Race to Capture and Control the Stem Cell
.
By Cynthia Fox
. Norton, New York, 2007. 558 pp. $26.95, C$35.50. ISBN 9780393058772.

Fox offers a timely and lively account of the science, history, politics, and sociology of stem cell research.
Ex Vivo Monitoring of Antigen-Specific CD4+T Cells after Recall Immunization with Tetanus Toxoid
Authors: Barbey Catherine , Pradervand Estelle , Barbier Nathalie , Spertini François
Published: July 2007

To monitor antigen-specific CD4+T cells during a recall immune response to tetanus toxoid (TT), a sequential analysis including ex vivo phenotyping and cytokine flow cytometry, followed by cloning and T-cell-receptor (TCR) spectratyping of cytokine-positive CD4+T cells, was performed. Grossly, twice as many TT-specific CD4+T-cell clones, ex vivo derived from the CCR7+/−CD69+interleukin-2-positive (IL-2+) CD4+subsets, belonged to the central memory (TCM; CD62L+CD27+CCR7+) compared to the effector memory population (TEM; CD62L−CD27−CCR7−). After the boost, a predominant expansion of the TCMpopulation was observed with more limited variations of the TEMpopulation. TCR beta-chain-variable region (BV) spectratyping and sequencing confirmed a large concordance between most frequently expressed BV TCR-CDR3 from ex vivo-sorted CCR7+/−CD69+IL-2+CD4+subsets and BV usage of in vitro-derived TT-specific CD4+T-cell clones, further demonstrating the highly polyclonal but stable character of the specific recall response to TT. Taken together, ex vivo flow cytometry analysis focused on the CCR7+/−CD69+IL-2+CD4+subsets appears to target the bulk of antigen-specific T cells and to reach an analytical power sufficient to adequately delineate in field trials the profile of the antigen-specific response to vaccine.
Aggregating Phenotype in
Lactobacillus crispatus
Determines Intestinal Colonization and TLR2 and TLR4 Modulation in Murine Colonic Mucosa
Authors: Voltan Sandra , Castagliuolo Ignazio , Elli Marina , Longo Stefano , Brun Paola , D'Incà Renata , Porzionato Andrea , Macchi Veronica , Palù Giorgio , Sturniolo Giacomo C. , Morelli Lorenzo , Martines Diego
Published: July 2007

The colonic microbiota is a major modulator of the mucosal immune system; therefore, its manipulation through supplementation with probiotics may significantly affect the host's immune responses. Since different probiotics seem to exert various effects in vivo, we tested the relevance of the autoaggregation phenotype on the intestinal persistence of lactobacilli and their ability to modulate the host's innate immune responses. After 14 days of diet supplementation, the aggregating strain
Lactobacillus crispatus
M247 but not aggregation-deficient isogenic mutant MU5 was recovered from the feces and colonic mucosa of mice. This observation was confirmed by strain-specific PCR amplification and by
Lactobacillus
-specific denaturing gradient gel electrophoresis analysis. Indeed,
L. crispatus
M247 increased Toll-like receptor 2 (TLR2) mRNA levels, while it reduced TLR4 mRNA and protein levels in the colonic mucosa, whereas MU5 was ineffective. In colonic epithelial cells (CMT-93 cells)
L. crispatus
M247 but not MU5 induced time-dependent extracellular signal-regulated kinase-1 (ERK1) tyrosine phosphorylation and TLR modulation, which were abolished in the presence of PD98059 (an ERK1 inhibitor). To assess the functional relevance of probiotic-induced TLR modulation, we determined the consequences of
L. crispatus
preexposure on TLR4 (lipopolysaccharide [LPS]) and TLR2 [Pam
3
Cys-Ser-(Lys)
4
] ligand-mediated effects in intestinal epithelial cells. Preexposure to
L. crispatus
M247 blunted LPS-induced interleukin-6 (IL-6) release and inhibition of CMT-93 migration over a wound edge, whereas it enhanced TLR2-mediated IL-10 up-regulation. In summary, the aggregation phenotype is required for
L. crispatus
persistence in the colon and for modulation of TLR2/TLR4 expression through an ERK-dependent pathway. We speculate that the aggregation phenotype in
L. crispatus
M247 is required to temper epithelial cell responsiveness to bacterial endotoxins, which thus affects the evolution of intestinal inflammatory processes.
Immunogenicity and Safety of a Combination of Two Serogroup B Meningococcal Outer Membrane Vesicle Vaccines
Authors: Sandbu Synne , Feiring Berit , Oster Philipp , Helland Oddveig S. , Bakke Hilde S. W. , Næss Lisbeth M. , Aase Audun , Aaberge Ingeborg S. , Kristoffersen Anne-Cathrine , Rydland Kjersti M. , Tilman Sandrine , Nøkleby Hanne , Rosenqvist Einar
Published: July 2007

MenBvac and MeNZB are safe and efficacious vaccines against serogroup B meningococcal disease. MenBvac is prepared from a B:15:P1.7,16 meningococcal strain (strain 44/76), and MeNZB is prepared from a B:4:P1.7-2,4 strain (strain NZ98/254). At 6-week intervals, healthy adults received three doses of MenBvac (25 μg), MeNZB (25 μg), or the MenBvac and MeNZB (doses of 12.5 μg of each vaccine) vaccines combined, followed by a booster 1 year later. Two-thirds of the subjects who received a monovalent vaccine in the primary schedule received the other monovalent vaccine as a booster dose. The immune responses to the combined vaccine were of the same magnitude as the homologous responses to each individual vaccine observed. At 6 weeks after the third dose, 77% and 87% of the subjects in the combined vaccine group achieved serum bactericidal titers of ≥4 against strains 44/76 and NZ98/254, respectively, and 97% and 93% of the subjects achieved a fourfold or greater increase in opsonophagocytic activity against strains 44/76 and NZ98/254, respectively. For both strains, a trend of higher responses after the booster dose was observed in all groups receiving at least one dose of the respective strain-specific vaccine. Local and systemic reactions were common in all vaccine groups. Most reactions were mild or moderate in intensity, and there were no vaccine-related serious adverse events. The safety profile of the combined vaccine was not different from those of the separate monovalent vaccines. In conclusion, use of either of the single vaccines or the combination of MenBvac and MeNZB may have a considerable impact on the serogroup B meningococcal disease situation in many countries.
Immunization of Broiler Chickens against
Clostridium perfringens
-Induced Necrotic Enteritis
Authors: Kulkarni R. R. , Parreira V. R. , Sharif S. , Prescott J. F.
Published: July 2007

Necrotic enteritis (NE) in broiler chickens is caused by
Clostridium perfringens
. Currently, no vaccine against NE is available and immunity to NE is not well characterized. Our previous studies showed that immunity to NE followed oral infection by virulent rather than avirulent
C. perfringens
strains and identified immunogenic secreted proteins apparently uniquely produced by virulent
C. perfringens
isolates. These proteins were alpha-toxin, glyceraldehyde-3-phosphate dehydrogenase, pyruvate:ferredoxin oxidoreductase (PFOR), fructose 1,6-biphosphate aldolase, and a hypothetical protein (HP). The current study investigated the role of each of these proteins in conferring protection to broiler chickens against oral infection challenges of different severities with virulent
C. perfringens
. The genes encoding these proteins were cloned and purified as histidine-tagged recombinant proteins from
Escherichia coli
and were used to immunize broiler chickens intramuscularly. Serum and intestinal antibody responses were assessed by enzyme-linked immunosorbent assay. All proteins significantly protected broiler chickens against a relatively mild challenge. In addition, immunization with alpha-toxin, HP, and PFOR also offered significant protection against a more severe challenge. When the birds were primed with alpha-toxoid and boosted with active toxin, birds immunized with alpha-toxin were provided with the greatest protection against a severe challenge. The serum and intestinal washings from protected birds had high antigen-specific antibody titers. Thus, we conclude that there are certain secreted proteins, in addition to alpha-toxin, that are involved in immunity to NE in broiler chickens.
The Binax NOW Test as a Tool for Diagnosis of Severe Acute Otitis Media and Associated Complications
Authors: Gisselsson-Solén Marie , Bylander Anita , Wilhelmsson Christina , Hermansson Ann , Melhus Åsa
Published: July 2007

The diagnosis of acute otitis media (AOM) is often difficult, depending heavily on the experience and skills of the examiner. However, it is important to identify episodes of AOM that involve the risk of complications and to treat these episodes appropriately. The present study was performed in order to evaluate the use of a rapid antigen assay for
Streptococcus pneumoniae
, the Binax NOW test, as a diagnostic tool in patients with severe AOM and associated complications. The study included 70 patients with 74 episodes of AOM, 18 of them with complications. Cultures, Binax NOW tests, and a PCR assay were performed on nasopharyngeal secretions, middle ear fluid, and in some cases mastoid bone, cerebrospinal fluid, and urine. According to culture and PCR of the middle ear fluid, 30 (41%) of the episodes were caused by
S. pneumoniae
. The Binax NOW test was positive in 24 of these episodes (80%). It identified pneumococcal AOM independent of antibiotic treatment, and it was easily adapted to bone tissue. The test yielded sensitivity, specificity, and positive and negative predictive values for middle ear specimens of 85%, 100%, 100%, and 89%, respectively. The corresponding positive and negative values for predicting the bacterial etiology with nasopharyngeal secretions were 51% and 75%. This study showed that the Binax NOW test is a useful diagnostic tool for patients with severe AOM with or without complications.
Molecular Characterization of Vancomycin-Resistant
Enterococcus faecium
Isolates from Mainland China
Authors: Zheng Bo , Tomita Haruyoshi , Xiao Yong Hong , Wang Shan , Li Yun , Ike Yasuyoshi
Published: July 2007

Little is known about vancomycin-resistant enterococci in China. Thirteen pulsed-field gel electrophoresis-confirmed heterogeneous VanA-type vancomycin-resistant
Enterococcus faecium
(VRE) isolates were obtained from five Chinese hospitals from 2001 to 2005. The isolates were typed by multilocus sequence typing into nine different sequence types (STs), including five new STs (ST18, ST25, ST78, ST203, ST320, ST321, ST322, ST323, and ST335). Vancomycin resistance in each isolate was encoded on conjugative plasmids; two of the plasmids, pZB18 (67 kbp) and pZB22 (200 kbp), were highly conjugative and were able to transfer at high frequencies of around 10
−4
and 10
−7
per donor cell in broth mating, respectively. None of the plasmids identified in these isolates carried
traA
, which is usually conserved in the pMG1-like highly conjugative plasmid for
E. faecium
, implying that pZB18 and pZB22 were novel types of a highly conjugative plasmid in enterococci. Thirteen Tn
1546
-like elements encoding VanA-type VRE on the conjugative plasmids were classified into six types (types I to VI), and most of them contained both IS
1216V
and IS
1542
insertions. The isolates carrying the type II element were predominant. The six type elements were different from that of a VanA-type
Enterococcus faecalis
strain isolated from Chinese chicken meat. The results suggested that the disseminations of VRE in these areas were by Tn
1546
-like elements being acquired by the conjugative plasmids and transferred among
E. faecium
strains.
Impact of the COBAS AmpliPrep/COBAS AMPLICOR HIV-1 MONITOR Test, Version 1.5, on Clinical Laboratory Operations
Authors: Germer Jeffrey J. , Bendel Jordan L. , Dolenc Craig A. , Nelson Sarah R. , Masters Amanda L. , Gerads Tara M. , Mandrekar Jayawant N. , Mitchell P. Shawn , Yao Joseph D. C.
Published: July 2007

The COBAS AmpliPrep/COBAS AMPLICOR HIV-1 MONITOR Test, version 1.5 (CAP/CA), and the COBAS AMPLICOR HIV-1 MONITOR Test, version 1.5, were compared. CAP/CA reduced and consolidated labor while modestly increasing assay throughput without increased failure rates or direct costs, regardless of batch size and assay format.
Molecular Study of Microsporidiosis Due toEnterocytozoon bieneusiandEncephalitozoon intestinalisamong Human Immunodeficiency Virus-Infected Patients from Two Geographical Areas: Niamey, Niger, and Hanoi, Vietnam
Authors: Espern Anne , Morio Florent , Miegeville Michel , Illa Hachimou , Abdoulaye Moustapha , Meyssonnier Vanina , Adehossi Eric , Lejeune Anne , Cam Phung Dac , Besse Bernard , Gay-Andrieu Françoise
Published: July 2007

Microsporidiosis cases due toEnterocytozoon bieneusiandEncephalitozoon intestinalisare emerging opportunistic infections associated with a wide range of clinical syndromes in humans. The aim of this study was to specify microsporidial epidemiology in two different geographical areas. From November 2004 to August 2005, 228 and 42 stool samples were collected in Niamey, Niger, and Hanoi, Vietnam, respectively. Screening for microsporidia was performed using UV-light microscopy. Detection was confirmed by molecular biology using two methods specific forE. bieneusiandE. intestinalis. All samples positive forE. bieneusiwere subjected to genotyping. In this study, we found high prevalences of microsporidiosis among human immunodeficiency virus-infected patients, 10.5% and 9.5%, respectively, in Niamey and Hanoi. These levels of prevalence are similar to those recorded in European countries before highly active antiretroviral therapy was introduced. In the samples positive forE. bieneusi, we found seven distinct genotypes, including two genotypes not previously described. TheE. bieneusigenotype distributions in the two geographical areas suggest different routes of infection transmission, person-to-person in Niger and zoonotic in Vietnam.
Molecular Epidemiological and Antibiotic Susceptibility Characterization of
Brucella
Isolates from Humans in Sicily, Italy
Authors: Marianelli Cinzia , Graziani Caterina , Santangelo Carmela , Xibilia Maria Teresa , Imbriani Alida , Amato Rosa , Neri Domenico , Cuccia Mario , Rinnone Sebastiano , Di Marco Vincenzo , Ciuchini Franco
Published: July 2007

Brucellosis is a serious problem in Sicily.
Brucella melitensis
was identified as the species most frequently isolated in humans in Italy. No data, however, are available about the molecular epidemiological characterization of
Brucella
isolates from humans. We have conducted this study to molecularly characterize clinical isolates of
Brucella
spp. and to evaluate their antimicrobial susceptibilities. Twenty
Brucella
isolates were studied. Differential growth characteristics and DNA polymorphisms such as the restriction patterns of the PCR-amplified
omp2a
and
omp2b
genes,
rpoB
nucleotide sequencing, and multiple-locus variable-number tandem repeat analysis of 16 loci (MLVA-16) were used to characterize the strains. In vitro antibiotic susceptibility was determined by the E-test method on two different agar media, and the results were compared. All isolates were identified as
B. melitensis
biovar 3.
rpoB
nucleotide sequence analysis allowed the identification of two different genotypes of
B. melitensis
biovar 3. On the other hand, the MLVA-16 typing assay recognized 17 distinct genotypes. All isolates were sensitive to all tested antibiotics (rifampin, doxycycline, ciprofloxacin, ceftriaxone, and trimethoprim-sulfamethoxazole), and the Mueller-Hinton agar plate is recommended for antibiotic susceptibility testing by the E-test method. Our findings identify
B. melitensis
biovar 3 as the etiological agent isolated in Sicily and encourage the use of both molecular methods, and in particular of the MLVA-16 assay, in epidemiological trace-back analysis. This study represents the first epidemiological data from molecular typing of
Brucella
strains circulating in Italy and, in particular, in eastern Sicily.
Bacterial Peritonitis Caused byKingella kingae
Authors: Bofinger Jason J. , Fekete Thomas , Samuel Rafik
Published: July 2007

Kingella kingaeis a commensal of the upper respiratory tract that occasionally causes skeletal infections in children and endocarditis in children and adults. We report a case of a 55-year-old man with liver disease and tense ascites who performed a paracentesis on himself and developedK. kingaeperitonitis and bacteremia.
The ORF49 Protein of Murine Gammaherpesvirus 68 Cooperates with RTA in Regulating Virus Replication
Authors: Lee Sangmi , Cho Hye-Jeong , Park Jung-Jin , Kim Yong-Sun , Hwang Seungmin , Sun Ren , Song Moon Jung
Published: July 2007

Our functional mapping study of murine gammaherpesvirus 68 (MHV-68, or γHV-68) revealed that a mutant harboring a transposon at the ORF49 locus (ORF49
null
) evidenced a highly attenuated in vitro growth. ORF49 resides adjacent to and in an opposite direction from RTA, the primary switch of the gammaherpesvirus life cycle. A FLAG-tagged ORF49 protein was able to transcomplement ORF49
null
, and a revertant of ORF49
null
restored its attenuated growth to a level comparable to that of the wild type. The FLAG-tagged ORF49 protein promoted the ability of RTA to activate downstream target promoters and enhanced virus replication from the ORF50
null
virus in the presence of RTA. Furthermore, ORF49 enhanced wild-type virus replication by increasing the RTA transcript levels. Our data indicate that ORF49 may perform an important function in MHV-68 replication in cooperation with RTA.
A Tyrosine-Based Signal Plays a Critical Role in the Targeting and Function of Adenovirus RIDα Protein
Authors: Cianciola Nicholas L. , Crooks Denise , Shah Ankur H. , Carlin Cathleen
Published: July 2007

Early region 3 genes of human adenoviruses contribute to the virus life cycle by altering the trafficking of cellular proteins involved in adaptive immunity and inflammatory responses. The ability of early region 3 genes to target specific molecules suggests that they could be used to curtail pathological processes associated with these molecules and treat human disease. However, this approach requires genetic dissection of the multiple functions attributed to early region 3 genes. The purpose of this study was to determine the role of targeting on the ability of the early region 3-encoded protein RIDα to downregulate the EGF receptor. A fusion protein between the RIDα cytoplasmic tail and glutathione
S
-transferase was used to isolate clathrin-associated adaptor 1 and adaptor 2 protein complexes from mammalian cells. Deletion and site-directed mutagenesis studies showed that residues 71-AYLRH of RIDα are necessary for in vitro binding to both adaptor complexes and that Tyr72 has an important role in these interactions. In addition, RIDα containing a Y72A point mutation accumulates in the
trans
-Golgi network and fails to downregulate the EGF receptor when it is introduced into mammalian cells as a transgene. Altogether, our data suggest a model where RIDα is trafficked directly from the
trans
-Golgi network to an endosomal compartment, where it intercepts EGF receptors undergoing constitutive recycling to the plasma membrane and redirects them to lysosomes.
Modification of Small RNAs Associated with Suppression of RNA Silencing by Tobamovirus Replicase Protein
Authors: Vogler Hannes , Akbergenov Rashid , Shivaprasad Padubidri V. , Dang Vy , Fasler Monika , Kwon Myoung-Ok , Zhanybekova Saule , Hohn Thomas , Heinlein Manfred
Published: July 2007

Plant viruses act as triggers and targets of RNA silencing and have evolved proteins to suppress this plant defense response during infection. Although
Tobacco mosaic tobamovirus
(TMV) triggers the production of virus-specific small interfering RNAs (siRNAs), this does not lead to efficient silencing of TMV nor is a TMV-green fluorescent protein (GFP) hybrid able to induce silencing of a GFP-transgene in
Nicotiana benthamiana
, indicating that a TMV silencing suppressor is active and acts downstream of siRNA production. On the other hand, TMV-GFP is unable to spread into cells in which GFP silencing is established, suggesting that the viral silencing suppressor cannot revert silencing that is already established. Although previous evidence indicates that the tobamovirus silencing suppressing activity resides in the viral 126-kDa small replicase subunit, the mechanism of silencing suppression by this virus family is not known. Here, we connect the silencing suppressing activity of this protein with our previous finding that
Oilseed rape mosaic tobamovirus
infection leads to interference with HEN1-mediated methylation of siRNA and micro-RNA (miRNA). We demonstrate that TMV infection similarly leads to interference with HEN1-mediated methylation of small RNAs and that this interference and the formation of virus-induced disease symptoms are linked to the silencing suppressor activity of the 126-kDa protein. Moreover, we show that also
Turnip crinkle virus
interferes with the methylation of siRNA but, in contrast to tobamoviruses, not with the methylation of miRNA.
Epstein-Barr Virus Latent Nuclear Antigens Can Induce Metastasis in a Nude Mouse Model
Authors: Kaul Rajeev , Murakami Masanao , Choudhuri Tathagata , Robertson Erle S.
Published: July 2007

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus associated with the development of both lymphoid and epithelial tumors. The EBV critical latent antigens EBNA1 and EBNA3C interact with Nm23-H1, a known suppressor of cell migration and tumor metastasis. This interaction is critical for the regulation of downstream cellular genes involved in tumorigenesis and cell migration. The significance of these interactions was determined in nude mice using cancer cells expressing both EBV antigens and Nm23-H1. The EBV antigens promoted the growth of transformed cells in vivo, but their expression was less critical during the later stage of tumor development. The expression of Nm23-H1 affected the growth of cancer cells and suppressed their metastatic potential. This effect was effectively rescued by the expression of both EBV antigens. Interestingly, the prometastatic potential of EBNA3C was greater than that of EBNA1, which triggered a dramatic immune response, as indicated by increased spleen size and development of ascites in the mice. These studies now bridge the expression of the EBV antigens with tumorigenesis and metastasis and widen the range of potential targets for development of therapies for EBV-associated malignancies.
Murine Gammaherpesvirus 68
ORF52
Encodes a Tegument Protein Required for Virion Morphogenesis in the Cytoplasm
Authors: Bortz Eric , Wang Lili , Jia Qingmei , Wu Ting-Ting , Whitelegge Julian P. , Deng Hongyu , Zhou Z. Hong , Sun Ren
Published: July 2007

The tegument, a semiordered matrix of proteins overlying the nucleocapsid and underlying the virion envelope, in viruses in the gamma subfamily of
Herpesviridae
is poorly understood. Murine gammaherpesvirus 68 (MHV-68) is a robust model for studying gammaherpesvirus virion structure, assembly, and composition, as MHV-68 efficiently completes the lytic phase and productively infects cultured cells. We have found that MHV-68
ORF52
encodes an abundant tegument protein conserved among gammaherpesviruses. Detergent sensitivity experiments revealed that the MHV-68 ORF52 protein is more tightly bound to the virion nucleocapsid than the ORF45 tegument protein but could be dissociated from particles that retained the ORF65 small capsomer protein. ORF52, tagged with enhanced green fluorescent protein or FLAG epitope, localized to the cytoplasm. A recombinant MHV-68 bacterial artificial chromosome mutant with a nonsense mutation incorporated into
ORF52
exhibited viral DNA replication, expression of late lytic genes, and capsid assembly and packaging at levels near those of the wild type. However, the MHV-68
ORF52
-null virus was deficient in the assembly and release of infectious virion particles. Instead, partially tegumented capsids produced by the
ORF52
-null mutant accumulated in the cytoplasm, containing conserved capsid proteins, the ORF64 and ORF67 tegument proteins, but virtually no ORF45 tegument protein. Thus, ORF52 is essential for the tegumentation and egress of infectious MHV-68 particles in the cytoplasm, suggesting an important conserved function in gammaherpesvirus virion morphogenesis.
Host Cell Cathepsins Potentiate Moloney Murine Leukemia Virus Infection
Authors: Kumar Pankaj , Nachagari Deepa , Fields Carolyn , Franks John , Albritton Lorraine M.
Published: July 2007

The roles of cellular proteases in Moloney murine leukemia virus (MLV) infection were investigated using MLV particles pseudotyped with vesicular stomatitis virus (VSV) G glycoprotein as a control for effects on core MLV particles versus effects specific to Moloney MLV envelope protein (Env). The broad-spectrum inhibitors cathepsin inhibitor III and E-64d gave comparable dose-dependent inhibition of Moloney MLV Env and VSV G pseudotypes, suggesting that the decrease did not involve the envelope protein. Whereas, CA-074 Me gave a biphasic response that differentiated between Moloney MLV Env and VSV G at low concentrations, at which the drug is highly selective for cathepsin B, but was similar for both glycoproteins at higher concentrations, at which CA-074 Me inhibits other cathepsins. Moloney MLV infection was lower on cathepsin B knockout fibroblasts than wild-type cells, whereas VSV G infection was not reduced on the B
−/−
cells. Taken together, these results support the notion that cathepsin B acts at an envelope-dependent step while another cathepsin acts at an envelope-independent step, such as uncoating or viral-DNA synthesis. Virus binding was not affected by CA-074 Me, whereas syncytium induction was inhibited in a dose-dependent manner, consistent with cathepsin B involvement in membrane fusion. Western blot analysis revealed specific cathepsin B cleavage of SU in vitro, while TM and CA remained intact. Infection could be enhanced by preincubation of Moloney MLV with cathepsin B, consistent with SU cleavage potentiating infection. These data suggested that during infection of NIH 3T3 cells, endocytosis brings Moloney MLV to early lysosomes, where the virus encounters cellular proteases, including cathepsin B, that cleave SU.
Hip osteoarthritis: influence of work with heavy lifting, climbing stairs or ladders, or combining kneeling/squatting with heavy lifting
Authors: Jensen L K
Published: July 2007

The aim of the study was to evaluate the evidence for an association between hip osteoarthritis (OA) and physical work demands. Systematic searches were made and epidemiological studies on hip OA and heavy lifting, including farming and construction work and climbing stairs, were reviewed for the period 1966–2007 inclusive. The quality of the studies was assessed and best-evidence syntheses of a causal relation between hip OA and physical demanding work have been made using specific criteria of the different degrees of evidence of causality. Limitations of the studies include few participants, use of different diagnostic criteria, and a poor description of the exposure. It is concluded that moderate to strong evidence was found for a relation between heavy lifting and hip OA. The burdens have to be at least 10–20 kg and the duration at least 10–20 years to give a clearly increased risk of hip OA. For farmers the risk of hip OA seems doubled after approximately 10 years of farming and the evidence is considered as moderate to strong. The evidence for a relation between hip OA for construction workers is limited and there is insufficient or no evidence that climbing stairs or ladders causes hip OA.
Knee osteoarthritis: influence of work involving heavy lifting, kneeling, climbing stairs or ladders, or kneeling/squatting combined with heavy lifting
Authors: Jensen L K
Published: July 2007

The purpose of the study was to evaluate the evidence for an association between knee osteoarthritis (kneeOA) and physical work demands. Systematic searches were made, and epidemiological studies on kneeOA and heavy lifting, kneeling and climbing stairs published in 1966 to 2007 inclusive were reviewed. The quality of the studies was assessed and an overall evaluation of the degree of evidence of a causal relationship between kneeOA and physically demanding work was made, using specific criteria of the different degrees of evidence of causality. Limitations of the studies include few participants, use of different diagnostic criteria and a poor description of the exposure. It is concluded that moderate evidence was found for a relationship between kneeling, heavy lifting and kneeOA. For the combination of kneeling/squatting and heavy lifting the association seemed stronger than for kneeling/squatting or heavy lifting alone, but only a few studies were found concerning this relationship. Therefore the degree of evidence for a causal relationship was considered to be moderate. In the studies on the association between kneeOA and climbing stairs or ladders, there was an increased risk for kneeOA, but only a few studies were found and no dose–response relationship has been investigated. The evidence of a causal relationship is therefore considered to be limited.