bluuebunny/crossref_metadata_2025 huggingface dataset:
Self‐rated health in the unwell elderly presenting to the emergency department
Authors: Wong Daniel D , Wong Reginald PC , Caplan Gideon A
Published: February 2007

Objective:  Self‐rated health (SRH) has been shown to be a reliable predictor of functional decline and mortality. These studies, however, have largely focused on well community‐dwelling elderly. We assessed whether the predictive value of SRH would still be valid for the acutely unwell older person presenting to the ED.

Methods:  The present study was a secondary analysis of data obtained from the Discharge of Elderly from Emergency Department (DEED II) study. The sample consisted of 741 older people sent home from an ED. On enrolment, patients were asked the SRH question, ‘In general, would you say your health is excellent, very good, good, fair or poor?’ Phone interviews were conducted at 3, 6, 12 and 18 months. Functional status was assessed using the Barthel index of activities of daily living (ADL), modified instrumental activities of daily living (IADL) and the Short Portable Mental Status Questionnaire (MSQ).

Results:  An SRH of fair/poor produced a hazard ratio of 3.1 (95% confidence interval 1.3–7.2, P = 0.010) for predicting mortality after controlling for confounders. The rate of decline in ADL and IADL (but not MSQ) over time was also more pronounced for those with an SRH of fair/poor (P < 0.001 for both ADL and IADL). An SRH of fair/poor had a relative risk of 3.4 for predicting decline in ADL at 18 months (95% confidence interval 1.7–7.1, P = 0.001). The effects of SRH on IADL and MSQ were not statistically significant.

Conclusions:  The ability of SRH to predict functional decline and mortality persists for the acutely unwell elderly presenting to the ED. SRH is a simple and valuable tool to assess the elderly in the ED and to identify high‐risk patients who would benefit from comprehensive geriatric assessment aimed at delaying such outcomes.
Site Variation in Spatial Aggregation and Phorophyte Preference in Psychilis monensis (Orchidaceae)
Authors: Otero J. Tupac , Aragón Susan , Ackerman James D.
Published: February 2007

Aggregation patterns of plants vary according to spatial scale and developmental stage, and are dependent on vegetation dynamics and species composition. We describe the aggregation patterns of the epiphytic orchid Psychilis monensis from two sites with different vegetation structure and composition on Mona Island, Puerto Rico. We analyzed spatial variation for seedlings, juveniles, and adults using the density‐independent, standardized Morisita index (IMS). We censused a total of 879 plants. Strong preferences for some phorophyte species were evident, including dead trees, but association with bark roughness was equivocal. The highest densities occurred in the site with the lowest fruit and seed production, suggesting that the best sites for pollination and seedling establishment were not the same. Seedlings at one site were significantly aggregated, but all other stages were indistinguishable from a random distribution. Nevertheless, adults at both sites had the lowest IMS values indicating that they tend to be the least aggregated of the three life history stages. The abundance and age structure of P. monensis were clearly affected by the frequency of their preferred hosts, but site‐specific factors affecting seedling survival probably play a major role in site differences.
Urbanization and Mismatch with Protected Areas Place the Conservation of a Threatened Species at Risk
Authors: Uehara‐Prado Marcio , Fonseca Rafael Luís
Published: February 2007

In this work, we report the predicted distribution of the threatened fluminense swallowtail butterfly, Parides ascanius (Cramer 1775), and correlate it to the presence of urban and protected areas within its range. The distribution was modeled using a genetic algorithm. The predicted distribution of the fluminense swallowtail shows high agreement within Rio de Janeiro state, in a near‐continuous strip of 2,038,253 ha along the coastal lowlands, 17.8 percent of which is within urban areas. Only 8.7 percent (178,187 ha) of the remaining (nonurban) predicted model overlapped at least partially with protected areas (19 in all). Almost half of these protected areas also overlapped with urban areas, resulting in an additional loss of 58,751 ha. In seven of 19 protected areas, the distribution of P. ascanius was predicted by less than 50 percent of the models; five of the remaining protected areas are less restrictive reserves. Despite the wide distribution predicted by the models, only two of the observed occurrence points matched the predicted distribution within protected areas. Modeling threatened species distribution is a useful tool for highlighting gaps in networks of protected areas and should aid in planning to fill these gaps. However, in several developing countries with high biodiversity, there is insufficient basic biological information for many threatened species. In these cases, prospecting field studies are urgently needed.
Arthropod Assemblages in Epiphyte Mats of Costa Rican Cloud Forests
Authors: Yanoviak Stephen P. , Nadkarni Nalini M. , Solano J. Rodrigo
Published: February 2007

Tropical cloud forests are functionally important ecosystems, but are severely threatened due to deforestation and fragmentation. Epiphyte mats, accumulations of live vegetation and dead organic matter on tree trunks and branches, are a conspicuous component of cloud forests and harbor diverse assemblages of meso‐ and microarthropods. We compared the morphospecies richness, composition, and abundance of arthropods in epiphyte mats between primary and secondary forests of Monteverde, Costa Rica, and at two nearby replicate sites. Epiphyte mats were thinner and less structurally diverse in secondary forest. We collected ca 36,000 micro‐ and mesoarthropods from epiphyte mats in the 2‐yr study. Whereas arthropod morphospecies richness did not differ among forest types, arthropod abundance was significantly higher in secondary forest due to larger numbers of ants, especially Solenopsis spp. Arthropod assemblages showed a high degree of taxonomic overlap both within and between primary and secondary forests (Jaccard abundance‐based similarity = 0.93–0.96). Although characteristics of the arthropod fauna proved to be similar among sites and between forest types, there was a significant temporal effect: arthropod morphospecies richness in epiphyte mats generally was lower in the dry season (February–May), when many taxa probably became dormant or sought shelter against desiccation in deeper portions of mats.
Exploring parents’ perceptions of television food advertising directed at children: A South Australian study
Authors: IP Joyce , MEHTA Kaye P. , COVENEY John
Published: February 2007

Objective:  To increase our understanding of parents’ perceptions of the influence of television food advertising on children’s food choices.

Design:  Five focus group discussions.

Subjects:  Thirty‐two parents (24 women and eight men) of children attending primary school.

Setting: Adelaide, South Australia.

Data analyses:  The focus group discussions were taped and transcribed and coded as themes. Transcripts were verified and coding was audited. All researchers met regularly to analyse data and reach consensus on emergent themes (researcher triangulation).

Results:  Parents who participated in the study indicated that television is a powerful source of information for children’s food choices. Parents expressed concern about the negative influence of television food advertising on children’s food preferences. They suggested that the current regulations governing television food advertising were not adequately enforced. Parents wanted to see an overall reduction in the volume of food advertisements directed at children, and an increase in advertisements promoting healthy foods. Parents expressed mixed views about banning food advertisements directed at children.

Conclusion:  In order for television food advertising to be health‐enhancing for children, parents in the study suggested the need for restrictions on advertising practices, tighter enforcement of existing regulations and an increase in healthy food advertisements. The present research shows that parents want to see changes in the current arrangements governing television food advertising to children.
Comparison of the guideline development processes used for type 2 diabetes dietetic practice guidelines
Authors: KNIGHTS Sallyanne , TAPSELL Linda
Published: February 2007

Objective:  To compare procedures used for the development of three sets of dietetic practice guidelines for type 2 diabetes: the Queensland Best Practice Guidelines (Queensland Guidelines), New Zealand Standards of Care (New Zealand Guidelines) (unpublished, 2003) and American Nutrition Practice Guidelines (American Guidelines) against National Health and Medical Research Council (NHMRC) standards for development of clinical practice guidelines.

Design:  The Queensland, New Zealand and American guidelines were audited against a checklist based on the NHMRC clinical practice guideline development standards, accounting for the recommended tasks and the order in which they should be completed. Additional information regarding the development processes was obtained from development coordinators of the existing dietetic practice guidelines for type 2 diabetes.

Results:  The American guidelines addressed more of the components of development recommended by the NHMRC than the Queensland and New Zealand guidelines. Most importantly the American guidelines were tested for clinical and cost effectiveness.

Conclusion or application:  The data presented show that the American Guidelines came closest to meeting the NHMRC criteria. These results suggest that the American Guidelines may best suit Australian requirements.
Enceladus: Cosmic Graffiti Artist Caught in the Act
Authors: Verbiscer Anne , French Richard , Showalter Mark , Helfenstein Paul
Published: February 2007

As one of the most geologically active bodies in the solar system, Saturn's moon Enceladus not only coats itself with water ice particles, it accounts for the unusually high albedos of the other satellites orbiting within Saturn's vast, tenuous E ring. This effect is evident in Hubble Space Telescope observations obtained at true opposition on 13 and 14 January 2005 that reveal that the mean geometric albedos of satellites embedded within the E ring approximate or exceed unity.
Relative Impact of Nucleotide and Copy Number Variation on Gene Expression Phenotypes
Authors: Stranger Barbara E. , Forrest Matthew S. , Dunning Mark , Ingle Catherine E. , Beazley Claude , Thorne Natalie , Redon Richard , Bird Christine P. , de Grassi Anna , Lee Charles , Tyler-Smith Chris , Carter Nigel , Scherer Stephen W. , Tavaré Simon , Deloukas Panagiotis , Hurles Matthew E. , Dermitzakis Emmanouil T.
Published: February 2007

Extensive studies are currently being performed to associate disease susceptibility with one form of genetic variation, namely, single-nucleotide polymorphisms (SNPs). In recent years, another type of common genetic variation has been characterized, namely, structural variation, including copy number variants (CNVs). To determine the overall contribution of CNVs to complex phenotypes, we have performed association analyses of expression levels of 14,925 transcripts with SNPs and CNVs in individuals who are part of the International HapMap project. SNPs and CNVs captured 83.6% and 17.7% of the total detected genetic variation in gene expression, respectively, but the signals from the two types of variation had little overlap. Interrogation of the genome for both types of variants may be an effective way to elucidate the causes of complex phenotypes and disease in humans.
Response to Comment on "Obestatin, a Peptide Encoded by the Ghrelin Gene, Opposes Ghrelin's Effects on Food Intake"
Authors: Zhang Jian V. , Klein Cynthia , Ren Pei-Gen , Kass Stefan , Donck Luc Ver , Moechars Dieder , Hsueh Aaron J. W.
Published: February 2007

We cannot reproduce our original findings on obestatin binding and activation of GPR39 receptors in vitro. However, we can reproduce our original findings on the in vivo effects of obestatin in mice (decreases in food intake, gastric emptying responses, and body weight gain) under precise experimental conditions. Further studies are needed to reveal the exact relation between obestatin and the G protein–coupled receptor GPR39.
Evidence That Focal Adhesion Complexes Power Bacterial Gliding Motility
Authors: Mignot Tâm , Shaevitz Joshua W. , Hartzell Patricia L. , Zusman David R.
Published: February 2007

The bacterium
Myxococcus xanthus
has two motility systems: S motility, which is powered by type IV pilus retraction, and A motility, which is powered by unknown mechanism(s). We found that A motility involved transient adhesion complexes that remained at fixed positions relative to the substratum as cells moved forward. Complexes assembled at leading cell poles and dispersed at the rear of the cells. When cells reversed direction, the A-motility clusters relocalized to the new leading poles together with S-motility proteins. The Frz chemosensory system coordinated the two motility systems. The dynamics of protein cluster localization suggest that intracellular motors and force transmission by dynamic focal adhesions can power bacterial motility.
Renewable Energy Sources and the Realities of Setting an Energy Agenda
Authors: Potočnik Janez
Published: February 2007

The European Commission has been devoting considerable attention to energy issues. This Perspective describes recent progress in Europe toward achieving goals for renewable energy use, and the role that technology can play, as well as the new Strategic Energy Package.
Generation and Characterization of Monoclonal Antibodies against Dengue Virus Type 1 for Epitope Mapping and Serological Detection by Epitope-Based Peptide Antigens
Authors: Chen Yun-Ching , Huang Hsien-Neng , Lin Chin-Tarng , Chen Yi-Fang , King Chwan-Chuen , Wu Han-Chung
Published: February 2007

Dengue virus (DEN), the pathogen behind dengue hemorrhagic fever, remains a public health problem in Asia and South America. In this study, monoclonal antibodies (MAbs) against DEN serotype 1 (DEN-1) were generated by fusing NSI/1-Ag4-1 mouse myeloma cells with lymphocytes from BALB/c mice immunized with DEN-1. Twelve MAbs were found to react specifically to the DENs by enzyme-linked immunosorbent assay, immunofluorescence analysis, and immunoblotting analysis. Five MAbs, namely, DA4-7, DA6-7, DA9-5, DA10-2, and DA11-13, were found to react with envelope proteins of DEN-1. Two serotype-specific MAbs of DEN-1, DA6-7 and DA11-13, were further shown to neutralize DEN-1 infection by a plaque reduction neutralization test. The neutralizing epitopes of these MAbs were further identified from a random peptide library displayed on phage. Immunopositive phage clones reacted specifically with these MAbs and did not react with normal mouse serum. Epitope-based peptide antigens were proved able to detect antibodies in serum samples collected from DEN-1-infected patients but not in those taken from DEN-2-infected patients or healthy controls. We believe that these MAbs and neutralizing epitopes will provide information that will lead to the development of DEN-1 serotype-specific diagnostic reagents and vaccines.
An Immunomagnetic Single-Platform Image Cytometer for Cell Enumeration Based on Antibody Specificity
Authors: Li Xiao , Tibbe Arjan G. J. , Droog Erik , Terstappen Leon W. M. M. , Greve Jan
Published: February 2007

Simplification of cell enumeration technologies is necessary, especially for resource-poor countries, where reliable and affordable enumeration systems are greatly needed. In this paper, an immunomagnetic single-platform image cytometer (SP ICM) for cell enumeration based on antibody specificity is reported. A chamber/magnet assembly was designed such that the immunomagnetically labeled, acridine orange-stained cells in a blood sample moved to the surface of the chamber, where a fluorescent image was captured and analyzed for cell enumeration. The system was evaluated by applying one kind of antibody to count leukocytes and one kind for each leukocyte subpopulation: CD45 for leukocytes, CD3 for T lymphocytes, and CD19 for B lymphocytes. Excellent precision and linearity were achieved. Moreover, these cell counts, each from blood specimens of 42 to 52 randomly selected patients, were compared with those obtained by SP (TruCount) and dual-platform (DP) flow cytometry (FCM) technologies. The cell counts obtained by our system were in between those obtained from the TruCount and DP FCM methods; and good correlations were achieved (R≥ 0.95). For CD4+counts, as we expected, the cell count by our system was significantly higher than the CD4+T-lymphocyte counts obtained by SP and DP FCM methods. Immunophenotyping of the immunomagnetically selected CD4+cells showed that, besides CD4+T lymphocytes, a proportion of the CD4+dim monocytes was also selected. Our system is a simple immunomagnetic SP ICM, which can potentially be used for enumeration of CD3+CD4+T lymphocytes in resource-poor countries if an additional CD3 immunofluorescent label is applied.
Immunoblot Assay Using Recombinant Antigens as a Supplemental Test To Confirm the Presence of Antibodies to
Trypanosoma cruzi
Authors: Cheng Kevin Y. , Chang Chi-Deu , Salbilla Vince A. , Kirchhoff Louis V. , Leiby David A. , Schochetman Gerald , Shah Dinesh O.
Published: February 2007

The diagnosis of chronic Chagas' disease is generally made by detecting antibodies to
Trypanosoma cruzi
. Most conventional serological tests are based on lysates of whole parasites or semipurified antigen fractions from
T. cruzi
epimastigotes grown in culture. The occurrence of inconclusive and false-positive results has been a persistent problem with the conventional assays, and there is no universally accepted gold standard for confirmation of positive test results. We describe here an immunoblot assay for detecting antibodies to
T. cruzi
in which four chimeric recombinant antigens (rAgs), designated FP3, FP6, FP10, and TcF, are used as target antigens. Each of these rAgs is composed of several antigenically distinct regions and includes repetitive as well as nonrepetitive sequences. Each rAg is coated as a discrete line on a nitrocellulose strip. Assay sensitivity was assessed by testing 345 specimens known to be positive for antibodies to
T. cruzi
. All 345 of these samples showed two to four reactive test bands in addition to the three on-board control bands that are on each strip. Assay specificity was determined by testing 500 specimens from random U.S. blood donors, all of which gave negative results. Based on the results obtained in this study, we propose the following scheme for interpretation of test results: (i) no bands or a single test band = a negative result; (ii) two or more test bands with at least one band showing intensity of 1+ or higher = a positive result; and (iii) multiple faint test bands (±) = indeterminate result. Based on this scheme, the prototype immunoblot assay showed sensitivity of 100% (
n
= 345) and specificity of 100% (
n
= 500). Additionally, all 269 potentially cross-reacting and
T. cruzi
antibody-negative specimens tested negative in our immunoblot assay. The rAg-based immunoblot assay has potential as a supplemental test for confirming the presence of antibodies to
T. cruzi
in blood specimens and for identifying false-positive results obtained with other assays.
Zoonotic Vaccinia Virus Infection in Brazil: Clinical Description and Implications for Health Professionals
Authors: de Souza Trindade Giliane , Drumond Betania Paiva , Guedes Maria Isabel Maldonado Coelho , Leite Juliana Almeida , Mota Bruno Eduardo Fernandes , Campos Marco Antônio , da Fonseca Flávio Guimarães , Nogueira Maurício Lacerda , Lobato Zélia Inês Portela , Bonjardim Cláudio Antônio , Ferreira Paulo César Peregrino , Kroon Erna Geessien
Published: February 2007

Bovine vaccinia virus outbreaks have been occurring in different regions of Brazil. We report here the time course of natural human infection by vaccinia virus and describe important clinical and epidemiological aspects of this zoonotic infection. The diagnosis of vaccinia virus infection was based on clinical, serological, and molecular procedures.
Molecular Identification of
Cryptococcus neoformans
Serotypes
Authors: Enache-Angoulvant A. , Chandenier J. , Symoens F. , Lacube P. , Bolognini J. , Douchet C. , Poirot J. L. , Hennequin C.
Published: February 2007

Cryptococcus neoformans
is a fungal pathogen that causes life-threatening infections primarily in immunocompromised hosts. Based on the genetic characteristics and serologic properties of capsular polysaccharides, three varieties and five serotypes have been defined:
C. neoformans
var.
neoformans
(serotype D),
C. neoformans
var.
grubii
(serotype A), hybrid serotype AD, and
C. neoformans
var.
gattii
(serotypes B and C). Epidemiologic features, such as geographic distribution and ecologic niche, and clinical characteristics have been shown to be associated with serotypes. At the present time, serotyping is based on agglutination tests with either commercial or “homemade” antisera or on immunofluorescence assays using a monoclonal antibody directed against the capsule polysaccharide. In this paper, we describe two molecular methods (PCR-restriction enzyme analysis and length polymorphism analysis) for
C. neoformans
serotype identification. Both are based on the sequence characteristics of a fragment of the
CAP59
gene required for capsule biosynthesis. Testing of 72
C. neoformans
strains including representatives of the five serotypes demonstrated the reliability of these methods.
Detection of Extended-Spectrum Beta-Lactamases among
Enterobacteriaceae
by Use of Semiautomated Microbiology Systems and Manual Detection Procedures
Authors: Wiegand Irith , Geiss Heinrich K. , Mack Dietrich , Stürenburg Enno , Seifert Harald
Published: February 2007

Three commercially available microbiology identification and susceptibility testing systems were compared with regard to their ability to detect extended-spectrum β-lactamase (ESBL) production in
Enterobacteriaceae
, i.e., the Phoenix Automated Microbiology System (BD Diagnostic Systems, Sparks, MD), the VITEK 2 System (bioMérieux, Marcy l'Etoile, France), and the MicroScan WalkAway-96 System (Dade Behring, Inc., West Sacramento, CA), using routine testing panels. One hundred fifty putative ESBL producers were distributed blindly to three participating laboratories. Conventional phenotypic confirmatory tests such as the disk approximation method, the CLSI double-disk synergy test, and the Etest ESBL were also evaluated. Biochemical and molecular characterization of β-lactamases performed at an independent laboratory was used as the reference method. One hundred forty-seven isolates of
Escherichia coli
,
Klebsiella pneumoniae
,
Klebsiella oxytoca
,
Enterobacter cloacae
,
Enterobacter aerogenes
,
Citrobacter freundii
,
Serratia marcescens
,
Proteus mirabilis
,
Proteus vulgaris
, and
Morganella morganii
were investigated. Of these isolates, 85 were identified as ESBL producers by the reference method. The remaining isolates were identified as non-ESBL producers; they were either hyperproducers of their chromosomal AmpC, Koxy, or SHV enzymes or lacked any detectable β-lactamase activity. The system with the highest sensitivity for the detection of ESBLs was the Phoenix (99%), followed by the VITEK 2 (86%) and the MicroScan (84%); however, specificity was more variable, ranging from 52% (Phoenix) to 78% (VITEK 2). The performance of the semiautomated systems differed widely with the species investigated. The sensitivities of the conventional test methods ranged from 93 to 94%. The double-disk synergy test showed the highest specificity and positive predictive value among all test methods, i.e., 97% and 98%, respectively.
Controlled Evaluation of the IDI-MRSA Assay for Detection of Colonization by Methicillin-Resistant
Staphylococcus aureus
in Diverse Mucocutaneous Specimens
Authors: de San Nour , Denis Olivier , Gasasira Marie-Fabrice , De Mendonça Ricardo , Nonhoff Claire , Struelens Marc J.
Published: February 2007

Rapid and reliable detection of methicillin-resistant
Staphylococcus aureus
(MRSA) carriers is crucial for the effective control of MRSA transmission in healthcare facilities. The aim of this study was to verify the performance of the IDI-MRSA real-time PCR assay for direct MRSA detection in diverse mucocutaneous swabs from hospitalized patients. Swabs from nares (
n
= 522) and skin or other superficial sites (
n
= 478) were prospectively collected for MRSA screening from 466 patients admitted to an 858-bed teaching hospital. Swabs were inoculated onto selective chromogenic MRSA-ID agar, buffer extraction solution for IDI-MRSA assay, and enrichment broth. MRSA was detected by culture in 100 specimens from 47 patients. Compared to enrichment culture, the sensitivity and specificity of the PCR assay were 81.0 and 97.0%, respectively, and its positive and negative predictive values were 75.0 and 97.9%, respectively. The IDI-MRSA assay was more sensitive on swabs from nares (90.6%) than from other body sites (76.5%,
P
< 0.01). The PCR assay detected MRSA in 42 of 47 patients with culture positive study samples. Of 26 patients with culture-negative but PCR-positive study samples, 11 were probable true MRSA carriers based on patient history and/or positive culture on a new sample. The median turnaround time for PCR results was 19 h versus 3 days for agar culture results and 6 days for enrichment culture results. These data confirm the value of IDI-MRSA assay for rapid screening of MRSA mucocutaneous carriage among hospitalized patients. Cost-effectiveness studies are warranted to evaluate the impact of this assay on infection control procedures in healthcare settings.
High Frequencies of Clindamycin and Tetracycline Resistance in Methicillin-Resistant
Staphylococcus aureus
Pulsed-Field Type USA300 Isolates Collected at a Boston Ambulatory Health Center
Authors: Han Linda L. , McDougal Linda K. , Gorwitz Rachel J. , Mayer Kenneth H. , Patel Jean B. , Sennott Janet M. , Fontana John L.
Published: February 2007

Individual or multiple resistance to clindamycin, tetracycline, erythromycin, levofloxacin, or mupirocin was detected in a large proportion of methicillin-resistant
Staphylococcus aureus
pulsed-field type USA300 isolates collected at an ambulatory health center in Boston. The clindamycin, tetracycline, and mupirocin resistance genes identified in these isolates are commonly associated with plasmids.
Deletion of
fetA
Gene Sequences in Serogroup B and C
Neisseria meningitidis
Isolates
Authors: Marsh Jane W. , O'Leary Mary M. , Shutt Kathleen A. , Harrison Lee H.
Published: February 2007

The immunogenic iron-regulated FetA outer membrane protein of
Neisseria meningitidis
is one of various outer membrane proteins that have been considered potential meningococcal vaccine candidates. In this report, we describe the characterization of three meningococcal isolates that have deleted
fetA
sequences through genetic recombination at repetitive elements.
Real-Time PCR Assay Using Specimens on Filter Disks as a Template for Detection of Cytomegalovirus in Urine
Authors: Nozawa Naoki , Koyano Shin , Yamamoto Yumiko , Inami Yuhki , Kurane Ichiro , Inoue Naoki
Published: February 2007

Since congenital cytomegalovirus (CMV) infection causes late-onset sequelae, the identification of CMV-infected newborns is important. For this purpose, we established a simple real-time PCR assay using a filter disk. Combined with the collection of urine using filter papers placed in the diaper, this assay can make CMV screening more feasible and cost-effective.
Characterization of Class I Newcastle Disease Virus Isolates from Hong Kong Live Bird Markets and Detection Using Real-Time Reverse Transcription-PCR
Authors: Kim L. Mia , King Daniel J. , Suarez David L. , Wong Chun W. , Afonso Claudio L.
Published: February 2007

Newcastle disease viruses isolated from Hong Kong live bird markets (LBMs) were not detected by a USDA-validated matrix gene real-time reverse transcription-PCR (RT-PCR) assay. Based upon phylogenetic analysis of the fusion gene, these viruses were related to lentogenic class I viruses found in U.S. LBMs and wild waterfowl. An alternative real-time RT-PCR assay which complements the matrix gene assay was developed to efficiently detect class I viruses.
Identification of a Third Human Polyomavirus
Authors: Allander Tobias , Andreasson Kalle , Gupta Shawon , Bjerkner Annelie , Bogdanovic Gordana , Persson Mats A. A. , Dalianis Tina , Ramqvist Torbjörn , Andersson Björn
Published: February 2007

We have previously reported on a system for large-scale molecular virus screening of clinical samples. As part of an effort to systematically search for unrecognized human pathogens, the technology was applied for virus screening of human respiratory tract samples. This resulted in the identification of a previously unknown polyomavirus provisionally named KI polyomavirus. The virus is phylogenetically related to other primate polyomaviruses in the early region of the genome but has very little homology (<30% amino acid identity) to known polyomaviruses in the late region. The virus was found by PCR in 6 (1%) of 637 nasopharyngeal aspirates and in 1 (0.5%) of 192 fecal samples but was not detected in sets of urine and blood samples. Since polyomaviruses have oncogenic potential and may produce severe disease in immunosuppressed individuals, continued searching for the virus in different medical contexts is important. This finding further illustrates how unbiased screening of respiratory tract samples can be used for the discovery of diverse virus types.
Human Immunodeficiency Virus Type 1: Resistance to Nucleoside Analogues and Replicative Capacity in Primary Human Macrophages
Authors: Perez-Bercoff Danielle , Wurtzer Sébastien , Compain Séverine , Benech Henri , Clavel François
Published: February 2007

Antiretroviral treatment failure is associated with the emergence of resistant human immunodeficiency virus type 1 (HIV-1) populations which often express altered replicative capacity (RC). The resistance and RC of clinical HIV-1 strains, however, are generally assayed using activated peripheral blood mononuclear cells (PBMC) or tumor cell lines. Because of their high proliferation rate and concurrent high deoxynucleoside triphosphate (dNTP) content, both resistance and RC alterations might be misestimated in these cell systems. We have evaluated the resistance of HIV-1 clones expressing a variety of RT resistance mutations in primary human macrophages using a single cycle system. Our experiments indicate that d4T, ddI, and 3TC are more potent in macrophages than in HeLa-derived P4 tumor cells. Mutant viruses bearing thymidine analogue mutations (TAMs) or the K65R mutation had similar resistance levels in the two cell types. Strikingly, however, the M184V mutant, although fully resistant to 3TC in P4 cells, maintained some susceptibility to 3TC in macrophages from 8 of 11 donors. Using the same system, we found that the impact of resistance mutations on HIV RC was minimal in activated PBMC and in P4 cells. In contrast, mutant viruses exhibited strongly impaired RC relative to the wild type (WT) in macrophages, with the following RC order: WT > two TAMs > four TAMs = M184V > K65R. In undifferentiated monocytes, WT virus replication could be detected in three of six donors, but replication of all mutant viruses remained undetectable. Altogether, our results confirm that nucleoside reverse transcriptase inhibitors (NRTIs) are powerful antiviral agents in differentiated macrophages, reveal that HIV resistance to some NRTIs may be less efficient in these cells, and indicate that resistance-associated loss of RC is more pronounced in macrophages than in high-dNTP content cell systems.
Fusogenic Variants of a Noncytopathic Paramyxovirus
Authors: Seth Shaguna , Skountzou Ioanna , Gernert Kim M. , Compans Richard W.
Published: February 2007

SER virus is a type 5 parainfluenza virus that does not exhibit syncytium formation, in contrast to most other paramyxoviruses. This property has been attributed, at least in part, to the presence of an extension of the cytoplasmic tail (CT) of the SER F protein, as truncations or mutations of this region resulted in enhanced fusion. In this study we used repeated passage to select for mutant SER viruses, which were found to be fusogenic. The mutant viruses replicated at levels comparable to or higher than the wild-type SER virus and caused plaque formation, in contrast to the wild-type virus which does not form plaques. The mutants differed strikingly in their plaque sizes. The F genes of mutant viruses were cloned and sequenced and shared some mutations, including a proline-to-leucine change at position 22 and an isoleucine-to-leucine substitution at position 191; other changes that were specific to each mutant were also found. The HN proteins of mutant viruses also showed mutations spanning the length of the protein whereas the M protein showed a consistent mutation, threonine to isoleucine, at position 129. The structure of the F protein was used to identify residues involved in the mutant phenotypes in terms of their location and proximity to heptad repeat domains.
Kaposi's Sarcoma-Associated Herpesvirus Promotes Angiogenesis by Inducing Angiopoietin-2 Expression via AP-1 and Ets1
Authors: Ye Feng-Chun , Blackbourn David J. , Mengel Michael , Xie Jian-Ping , Qian Li-Wu , Greene Whitney , Yeh I-Tien , Graham David , Gao Shou-Jiang
Published: February 2007

Infection by Kaposi's sarcoma-associated herpesvirus (KSHV) is required for the development of Kaposi's sarcoma (KS), a highly inflammatory angiogenic tumor of endothelial cells commonly found in untreated AIDS patients. Angiopoietin 2 (Ang-2) modulates the vasculature during inflammation and angiogenesis, but the mechanism by which KSHV regulates Ang-2 expression has not been investigated. Here, we show that KSHV infection of primary human umbilical vein endothelial cells induced the expression and release of Ang-2, which in turn was required for KSHV-induced paracrine-dependent angiogenesis in vivo. Ang-2 was strongly expressed in small vessels and spindle tumor cells in KS tumors. Mechanistically, KSHV activated the Ang-2 promoter via AP-1 and Ets1 transcriptional factors, which were mediated by ERK, JNK, and p38 mitogen-activated protein kinase (MAPK) pathways. Our findings demonstrate the importance of Ang-2 in KS angiogenesis and define a novel role for AP-1 and MAPK pathways in regulating angiogenesis. This study also illustrates a distinct mechanism by which a tumor virus modulates vasculature to promote tumorigenesis and exemplifies the convergence of oncogenesis and angiogenesis pathways in tumor development.
Kaposi's Sarcoma-Associated Herpesvirus Induces Sustained NF-κB Activation during De Novo Infection of Primary Human Dermal Microvascular Endothelial Cells That Is Essential for Viral Gene Expression
Authors: Sadagopan Sathish , Sharma-Walia Neelam , Veettil Mohanan Valiya , Raghu Hari , Sivakumar Ramu , Bottero Virginie , Chandran Bala
Published: February 2007

In vitro Kaposi's sarcoma-associated herpesvirus (KSHV) infection of primary human dermal microvascular endothelial (HMVEC-d) cells and human foreskin fibroblast (HFF) cells is characterized by the induction of preexisting host signal cascades, sustained expression of latency-associated genes, transient expression of a limited number of lytic genes, and induction of several cytokines, growth factors, and angiogenic factors. Since NF-κB is a key molecule involved in the regulation of several of these factors, here, we examined NF-κB induction during de novo infection of HMVEC-d and HFF cells. Activation of NF-κB was observed as early as 5 to 15 min postinfection by KSHV, and translocation of p65-NF-κB into nuclei was detected by immunofluorescence assay, electrophoretic mobility shift assay, and p65 enzyme-linked immunosorbent assay. IκB phosphorylation inhibitor (Bay11-7082) reduced this activation significantly. A sustained moderate level of NF-κB induction was seen during the observed 72 h of in vitro KSHV latency. In contrast, high levels of ERK1/2 activation at earlier time points and a moderate level of activation at later times were observed. p38 mitogen-activated protein kinase was activated only at later time points, and AKT was activated in a cyclic manner. Studies with UV-inactivated KSHV suggested a role for virus entry stages in NF-κB induction and a requirement for KSHV viral gene expression in sustained induction. Inhibition of NF-κB did not affect target cell entry by KSHV but significantly reduced the expression of viral latent open reading frame 73 and lytic genes. KSHV infection induced the activation of several host transcription factors, including AP-1 family members, as well as several cytokines, growth factors, and angiogenic factors, which were significantly affected by NF-κB inhibition. These results suggest that during de novo infection, KSHV induces sustained levels of NF-κB to regulate viral and host cell genes and thus possibly regulates the establishment of latent infection.
Transmission and Adaptation of Chronic Wasting Disease to Hamsters and Transgenic Mice: Evidence for Strains
Authors: Raymond Gregory J. , Raymond Lynne D. , Meade-White Kimberly D. , Hughson Andrew G. , Favara Cynthia , Gardner Donald , Williams Elizabeth S. , Miller Michael W. , Race Richard E. , Caughey Byron
Published: February 2007

In vitro screening using the cell-free prion protein conversion system indicated that certain rodents may be susceptible to chronic wasting disease (CWD). Therefore, CWD isolates from mule deer, white-tailed deer, and elk were inoculated intracerebrally into various rodent species to assess the rodents' susceptibility and to develop new rodent models of CWD. The species inoculated were Syrian golden, Djungarian, Chinese, Siberian, and Armenian hamsters, transgenic mice expressing the Syrian golden hamster prion protein, and RML Swiss and C57BL10 wild-type mice. The transgenic mice and the Syrian golden, Chinese, Siberian, and Armenian hamsters had limited susceptibility to certain of the CWD inocula, as evidenced by incomplete attack rates and long incubation periods. For serial passages of CWD isolates in Syrian golden hamsters, incubation periods rapidly stabilized, with isolates having either short (85 to 89 days) or long (408 to 544 days) mean incubation periods and distinct neuropathological patterns. In contrast, wild-type mouse strains and Djungarian hamsters were not susceptible to CWD. These results show that CWD can be transmitted and adapted to some species of rodents and suggest that the cervid-derived CWD inocula may have contained or diverged into at least two distinct transmissible spongiform encephalopathy strains.
Inhibition of Airway Na
+
Transport by Respiratory Syncytial Virus
Authors: Kunzelmann Karl , Sun Jane , Meanger Jayesh , King Nicholas J. , Cook David I.
Published: February 2007

In previous studies, we have shown that two major respiratory pathogens, influenza virus and parainfluenza virus, produce acute alterations in ion transport upon contacting the apical membrane of the respiratory epithelium. In the present study, we examine the effects on ion transport by the mouse tracheal epithelium of a third major respiratory pathogen, respiratory syncytial virus (RSV). RSV infections are associated with fluid accumulation in the respiratory tract and cause illnesses that range in severity from rhinitis, sinusitis, otitis media, and bronchitis to bronchiolitis and pneumonia. We find that within minutes of RSV contacting the apical membrane; it inhibits amiloride-sensitive Na
+
transport by the epithelium. This effect is mediated by protein kinase C and is reproduced by recombinant viral F (fusion) protein. Since this inhibition is not accompanied by any alteration in the epithelial responses to carbachol or to forskolin plus 3-isobutyl-1-methylxanthine (IBMX), it is not due to a nonspecific toxic action of the virus. The inhibition also appears to require Toll-like receptor 4 and the presence of asialogangliosides in the apical membrane. Since the concentration range over which this inhibition is observed (10
2
to 10
5
PFU/ml) is comparable to the viral concentrations observed in clinical and experimental RSV infections, it seems likely that direct inhibition by the virus of epithelial Na
+
transport may contribute to the fluid accumulation that is observed in RSV infections.
Enzymatic Activities of Human Cytomegalovirus Maturational Protease Assemblin and Its Precursor (pPR, pUL80a): Maximal Activity of pPR Requires Self-Interaction through Its Scaffolding Domain
Authors: Brignole Edward J. , Gibson Wade
Published: February 2007

Herpesviruses encode an essential, maturational serine protease whose catalytic domain, assemblin (28 kDa), is released by self-cleavage from a 74-kDa precursor (pPR, pUL80a). Although there is considerable information about the structure and enzymatic characteristics of assemblin, a potential pharmacologic target, comparatively little is known about these features of the precursor. To begin studying pPR, we introduced five point mutations that stabilize it against self-cleavage at its internal (I), cryptic (C), release (R), and maturational (M) sites and at a newly discovered “tail” (T) site. The resulting mutants, called ICRM-pPR and ICRMT-pPR, were expressed in bacteria, denatured in urea, purified by immobilized metal affinity chromatography, and renatured by a two-step dialysis procedure and by a new method of sedimentation into glycerol gradients. The enzymatic activities of the pPR mutants were indistinguishable from that of IC-assemblin prepared in parallel for comparison, as determined by using a fluorogenic peptide cleavage assay, and approximated rates previously reported for purified assemblin. The percentage of active enzyme in the preparations was also comparable, as determined by using a covalent-binding suicide substrate. An unexpected finding was that, in the absence of the kosmotrope Na
2
SO
4
, optimal activity of pPR requires interaction through its scaffolding domain. We conclude that although the enzymatic activities of assemblin and its precursor are comparable, there may be differences in how their catalytic sites become fully activated.
Characterization of Hepatitis B Virus (HBV)-Specific T-Cell Dysfunction in Chronic HBV Infection
Authors: Boni Carolina , Fisicaro Paola , Valdatta Caterina , Amadei Barbara , Di Vincenzo Paola , Giuberti Tiziana , Laccabue Diletta , Zerbini Alessandro , Cavalli Albertina , Missale Gabriele , Bertoletti Antonio , Ferrari Carlo
Published: February 2007

Dysfunctional CD8+T cells present in chronic virus infections can express programmed death 1 (PD-1) molecules, and the inhibition of the engagement of PD-1 with its ligand (PD-L1) has been reported to enhance the antiviral function of these T cells. We took advantage of the wide fluctuations in levels of viremia which are typical of chronic hepatitis B virus (HBV) infection to comprehensively analyze the impact of prolonged exposure to different virus quantities on virus-specific T-cell dysfunction and on its reversibility through the blocking of the PD-1/PD-L1 pathway. We confirm that chronic HBV infection has a profound effect on the HBV-specific T-cell repertoire. Despite the use of a comprehensive panel of peptides covering all HBV proteins, HBV-specific T cells were rarely observed directly ex vivo in samples from patients with chronic infection, in contrast to those from patients with acute HBV infection. In chronic HBV infection, virus-specific T cells were detected mainly in patients with lower levels of viremia. These HBV-specific CD8+T cells expressed PD-1, and their function was improved by the blocking of PD-1/PD-L1 engagement. Thus, a broad spectrum of anti-HBV immunity is expressed by patients with chronic HBV infection and this spectrum is proportional to HBV replication levels and can be improved by blocking the PD-1/PD-L1 pathway. This information may be useful for the design of immunotherapeutic strategies to complement and optimize available antiviral therapies.
The energetics of the X2 + X– → X3– equilibrium (X = Cl, Br, I) in aqueous and nonaqueous solution
Authors: Crawford Evan , McIndoe J Scott , Tuck (the late) Dennis G.
Published: February 2007

The magnitude of the stability constants (K) for the formation of X3– from X– and X2 (X = Cl, Br, I) in aqueous and nonaqueous solution depends strongly on both X and solvent. Thermodynamic arguments establish that for aqueous solutions this is not the result of differing bond strengths in the X3– anion but rather depends on the solvation energies of the relevant anions and halogens. The experimental results for K in different organic solvents can also be rationalized in terms which emphasise solvation effects. Electrospray ionization mass spectrometry (ESI-MS) has been used to qualitatively probe relative bond strengths in the absence of solvent.Key words: trihalides, stability constants, solvation, electrospray ionization, mass spectrometry.
Carbonate radical anion — Thermochemistry
Authors: Armstrong D A , Waltz W L , Rauk A
Published: February 2007

High level ab initio calculations along with isodesmic reactions have been used to derive a set of self-consistent free energies of formation for carbonate and nitrate species in the gas phase and in aqueous solution. The results show that HCO3· is a strong acid, pKa = –4.1, and that E°(CO3·–/CO32) = 1.23 ± 0.15 V.Key words: carbonate radical anion, theoretical, thermochemistry, acidity, reduction potentials.
Electrocatalytic hydrogenation of catechol on Rh–Al2O3 in different media — pH-Dependent reduction mechanism for intermediate formation
Authors: Brisach-Wittmeyer Anne , Bouchard Nicolas-Alexandre , Breault Raymond , Ménard Hugues
Published: February 2007

The electrocatalytic hydrogenation of catechol was carried out in aqueous media in different pH ranges with Rh–Al2O3 powder catalyst. The reactions were conducted in an H-cell used as a dynamic cell, with a reticulated vitreous carbon electrode in contact with the catalyst powder as the working electrode. It was shown that the final product is 1,2-cyclohexanediol (cis and trans isomers) and that several intermediates are detected depending on the pH of the solution. Different media, from pH 5 to 13, were studied. One of the intermediates is 1,2-cyclohexanedione, detected at all pH values. The other is 2-hydroxycyclohexan-1-one, only observed at pH ≤ 7. To determine the mechanism of the reactions involved, the electrocatalytic hydrogenation of these intermediates to form the final 1,2-cyclohexanediol product was also conducted, and their UV spectroscopy and cyclic voltammetry data recorded. The influence of the nature of the solution was screened by measuring the Henry constant of each molecule.Key words: electrocatalytic hydrogenation of catechol, pH-dependent reduction mechanism, UV–vis spectroscopy, cyclic voltammetry, Henry constants.
A STOPPING RULE FOR THE CONJUGATE GRADIENT REGULARIZATION METHOD APPLIED TO INVERSE PROBLEMS IN ACOUSTICS
Authors: DELILLO THOMAS , HRYCAK TOMASZ
Published: February 2007

We present a novel parameter choice strategy for the conjugate gradient regularization algorithm which does not assume a priori information about the magnitude of the measurement error. Our approach is to regularize within the Krylov subspaces associated with the normal equations. We implement conjugate gradient via the Lanczos bidiagonalization process with reorthogonalization, and then we construct regularized solutions using the SVD of a bidiagonal projection constructed by the Lanczos process. We compare our method with the one proposed by Hanke and Raus and illustrate its performance with numerical experiments, including detection of acoustic boundary vibrations.