bluuebunny/crossref_metadata_2025 huggingface dataset:
Monoclonal Antibody-Based Competitive Enzyme-Linked Immunosorbent Assay for Detecting and Quantifying West Nile Virus-Neutralizing Antibodies in Horse Sera
Authors: Choi Kang-Seuk , Ko Young-Joon , Nah Jin-Ju , Kim Yong-Joo , Kang Shien-Young , Yoon Kyoung-Jin , Joo Yi-Seok
Published: November 2006

A rapid immunoassay for detecting and quantifying West Nile virus (WNV)-neutralizing antibodies in sera was developed as an alternative to the plaque reduction neutralization test (PRNT), the gold standard test for WNV. The assay is a competitive, enzyme-linked immunosorbent assay using neutralizing monoclonal antibody 5E8 (NT-ELISA). A cutoff percent inhibition (PI) value of 35% (mean PI plus 3 standard deviations), with a specificity of 99%, was established based on analysis of 246 serum samples from horses free of WNV. The NT-ELISA detected neutralizing antibodies in all sera collected 7 or 14 days postinoculation from mice (n= 11) infected with lineage I (strain NY385-99) or II (strain B956) WNV. When sera from WNV-vaccinated horses (n= 212) were tested by NT-ELISA and PRNT, the NT-ELISA gave a positive result for 96.1% (173/180) of the PRNT-positive sera and 3.1% (1/32) of the PRNT-negative sera. Discrepancies between the two tests were observed mainly with sera with low PRNT90titers (expressed as the reciprocal of the highest dilution yielding ≥90% reduction in the number of plaques) for WNV or low PIs by NT-ELISA. The overall agreement (kvalue) between the two tests was 0.86. A good correlation (r2= 0.77) was also observed between the tests for endpoint titration of sera (n= 116). In conclusion, the newly developed NT-ELISA may be a good alternative serologic assay for detecting WNV that can be used for large-scale testing of WNV-neutralizing antibodies in multiple species.
Sequencing of the
pncA
Gene in Members of the
Mycobacterium tuberculosis
Complex Has Important Diagnostic Applications: Identification of a Species-Specific
pncA
Mutation in “
Mycobacterium canettii
” and the Reliable and Rapid Predictor of Pyrazinamide Resistance
Authors: Somoskovi Akos , Dormandy Jillian , Parsons Linda M. , Kaswa Michel , Goh Khye Seng , Rastogi Nalin , Salfinger Max
Published: November 2006

Testing for susceptibility to pyrazinamide (PZA) and analysis of the
pncA
gene sequences of 423
Mycobacterium tuberculosis
complex isolates have revealed a unique silent nucleotide substitution that enables the rapid identification of “
M. canettii
” (proposed name). Moreover, the lack of a defined mutation within the
pncA
gene strongly suggests that an alternative mechanism is responsible for PZA resistance. Our results indicate that DNA sequencing of the
pncA
gene has the potential to shorten the turnaround time and increase the accuracy of PZA susceptibility testing of the
M. tuberculosis
complex.
Conjugative Transfer of Chromosomally Encoded Antibiotic Resistance from
Helicobacter pylori
to
Campylobacter jejuni
Authors: Oyarzabal Omar A. , Rad Roland , Backert Steffen
Published: November 2006

Many strains of
Helicobacter pylori
are naturally competent for transformation and able to transfer chromosomal DNA among different isolates using a conjugation-like mechanism. In this study, we sought to determine whether
H. pylori
can transfer DNA into
Campylobacter jejuni
, a closely related species of the
Campylobacterales
group. To monitor the transfer, a chromosomally encoded streptomycin resistance cassette prearranged by a specific mutation in the
rpsL
gene of
H. pylori
was used. Mating of the bacteria on plates or in liquid broth medium produced
C. jejuni
progeny containing the streptomycin marker. DNA transfer was unidirectional, from
H. pylori
to
C. jejuni
, and the progeny were genetically identical to
C. jejuni
recipient strains. DNase I treatment reduced but did not eliminate transfer, and DNase I-treated cell supernatants did not transform, ruling out phage transduction. Recombinants also did not occur when the mating bacteria were separated by a membrane, suggesting that DNA transfer requires cell-to-cell contact. Transfer of the streptomycin marker was independent of the
H. pylori comB
transformation system, the
cag
pathogenicity island, and another type IV secretion system called
tfs3
. These findings indicated that a DNase I-resistant, conjugation-like mechanism may contribute to horizontal DNA transfer between different members of the
Campylobacteriales
group. The significance of this DNA uptake by
C. jejuni
in the context of acquiring antibiotic resistance is discussed.
Identification of Sequence Diversity in the
Escherichia coli fliC
Genes Encoding Flagellar Types H8 and H40 and Its Use in Typing of Shiga Toxin-Producing
E. coli
O8, O22, O111, O174, and O179 Strains
Authors: Beutin Lothar , Strauch Eckhard
Published: November 2006

Flagellar type H8 is associated with many strains of pathogenic Shiga toxin-producing
Escherichia coli
(STEC), such as O8, O22, O111, O174, and O179 strains. Serological typing of the H8 antigen is limited to motile strains only and suffers from cross-reactivity between flagellar H8 and H40 antigens. In order to develop a method useful for typing of motile and nonmotile STEC O111 and other strains, we have analyzed the flagellar antigen (
fliC
) genes in representative
E. coli
H8 and H40 types. Two genotypes of the
fliC
gene encoding H8 (the
fliC
-H8 gene) were identified. Genotype
fliC
-H8a was found to be conserved in STEC O111, O174, and O179 strains; and type
fliC
-H8b was associated with STEC O8 and O22 strains. Sequence variations were also found in the genetically closely related
fliC
-H40 gene, although the latter was not found to be associated with STEC strains. A PCR was developed for the specific identification of the
fliC
-H8 and the
fliC
-H40 genes in motile and nonmotile
E. coli
strains. Digestion of PCR products with HhaI resulted in restriction fragment length polymorphisms (RFLPs) which were associated with genotypes
fliC
-H8a and -H8b as well as with genotypes
fliC
-H40a and -H40b. The
fliC
-specific PCR/RFLP typing method was suitable for the rapid typing of motile and nonmotile STEC O8, O22, O111, O174, and O179 strains from different sources whose
fliC
-H8 genotypes were found to be highly conserved. The
fliC
genotyping method is advantageous over serotyping and is useful for epidemiological investigations and studies of the evolution of STEC clones.
Discovering Potential Pathogens among Fungi Identified as Nonsporulating Molds
Authors: Pounder June I. , Simmon Keith E. , Barton Claudia A. , Hohmann Sheri L. , Brandt Mary E. , Petti Cathy A.
Published: November 2006

Fungal infections are increasing, particularly among immunocompromised hosts, and a rapid diagnosis is essential to initiate antifungal therapy. Often fungi cannot be identified by conventional methods and are classified as nonsporulating molds (NSM).We sequenced internal transcribed spacer regions from 50 cultures of NSM and found 16 potential pathogens that can be associated with clinical disease. In selected clinical settings, identification of NSM could prove valuable and have an immediate impact on patient management.
Diversity in Indian Equine Rotaviruses: Identification of Genotype G10,P6[1] and G1 Strains and a New VP7 Genotype (G16) Strain in Specimens from Diarrheic Foals in India
Authors: Gulati B. R. , Deepa R. , Singh B. K. , Rao C. Durga
Published: November 2006

Rotaviruses causing severe diarrhea in foals in two organized farms in northern India, during the period from 2003 to 2005, were characterized by electropherotyping, serotyping, and sequence analysis of the genes encoding the outer capsid proteins. Of 137 specimens, 47 (34.31%) were positive for rotavirus and exhibited at least five different electropherotypes (E), E1 to E5. Strains belonging to different electropherotypes exhibited either a different serotype/genotype specificity or a lack of reactivity to typing monoclonal antibodies (MAbs) used in this study. Strains belonging to E1, E2, and E5 exhibited genotype G10,P6[1], G3, and G1 specificities and accounted for 19.0, 42.9, and 9.5% of the isolates, respectively. Though they possessed G10-type VP7, the E1 strains exhibited high reactivity with the G6-specific MAb, suggesting that the uncommon combination of the outer capsid proteins altered the specificity of the conformation-dependent antigenic epitopes on VP7. E3 and E4 strains accounted for 28.6% of the isolates and were untypeable. Sequence analysis of VP7 from E4 strains (Erv92 and Erv99) revealed that they represent a new VP7 genotype, G16. The detection of unexpected bovine rotavirus-derived G10,P6[1] reassortants, G1 serotype strains, and a new genotype (G16) strain in two distant farms reveals an interesting epidemiological situation and diversity of equine rotaviruses in India.
Rapid and Real-Time Detection of Chikungunya Virus by Reverse Transcription Loop-Mediated Isothermal Amplification Assay
Authors: Parida M. M. , Santhosh S. R. , Dash P. K. , Tripathi N. K. , Lakshmi V. , Mamidi N. , Shrivastva A. , Gupta N. , Saxena P. , Babu J. Pradeep , Rao P. V. Lakshmana , Morita Kouichi
Published: November 2006

The standardization and validation of a one-step, single-tube, accelerated, quantitative reverse transcription (RT) loop-mediated isothermal amplification (RT-LAMP) assay targeting the E1 gene for the rapid and real-time detection of Chikungunya virus (CHIKV) are reported. A linear relationship between the amount of template and time of positivity value over a range of 2 × 10
8
to 2 × 10
2
copies was obtained. The feasibility of CHIKV RT-LAMP for clinical diagnosis was validated with patient serum samples from an ongoing epidemic in Southern India. Optimal assay conditions with zero background were established for the detection of low levels of CHIKV in acute-phase patient serum samples. The comparative evaluation of the RT-LAMP assay with acute-phase patient serum samples demonstrated exceptionally higher sensitivity by correctly identifying 21 additional positive borderline cases that were missed by conventional RT-PCR (
P
< 0.0001) with a detection limit of 20 copies. The quantification of virus load in patient serum samples was also determined from the standard curve based on their time of positivity and was found to be in the range of 2 × 10
8
to 2 × 10
1
copies. In addition, the field applicability of the RT-LAMP assay was also demonstrated by standardizing SYBR Green I-based RT-LAMP wherein the amplification was carried out in a water bath at 63°C for 60 min, which was followed by monitoring gene amplification with the naked eye through color changes. These findings demonstrated that the RT-LAMP assay is a valuable tool for rapid, real-time detection as well as quantification of CHIKV in acute-phase serum samples without requiring any sophisticated equipment and has potential usefulness for clinical diagnosis and surveillance of CHIKV in developing countries.
Comparison of Disk Diffusion, VITEK 2, and Broth Microdilution Antimicrobial Susceptibility Test Results for Unusual Species of
Enterobacteriaceae
Authors: Stone Nimalie D. , O'Hara Caroline M. , Williams Portia P. , McGowan John E. , Tenover Fred C.
Published: November 2006

We compared the antimicrobial susceptibility testing results generated by disk diffusion and the VITEK 2 automated system with the results of the Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) reference method for 61 isolates of unusual species of
Enterobacteriaceae
. The isolates represented 15 genera and 26 different species, including
Buttiauxella
,
Cedecea
,
Kluyvera
,
Leminorella
, and
Yokenella
. Antimicrobial agents included aminoglycosides, carbapenems, cephalosporins, fluoroquinolones, penicillins, and trimethoprim-sulfamethoxazole. CLSI interpretative criteria for
Enterobacteriaceae
were used. Of the 12 drugs tested by BMD and disk diffusion, 10 showed >95% categorical agreement (CA). CA was lower for ampicillin (80.3%) and cefazolin (77.0%). There were 3 very major errors (all with cefazolin), 1 major error (also with cefazolin), and 26 minor errors. Of the 40 isolates (representing 12 species) that could be identified with the VITEK 2 database, 36 were identified correctly to species level, 1 was identified to genus level only, and 3 were reported as unidentified. VITEK 2 generated MIC results for 42 (68.8%) of 61 isolates, but categorical interpretations (susceptible, intermediate, and resistant) were provided for only 22. For the 17 drugs tested by both BMD and VITEK 2, essential agreement ranged from 80.9 to 100% and CA ranged from 68.2% (ampicillin) to 100%; thirteen drugs exhibited 100% CA. In summary, disk diffusion provides a reliable alternative to BMD for testing of unusual
Enterobacteriaceae
, some of which cannot be tested, or produce incorrect results, by automated methods.
Brain Abscess Associated with Multidrug-Resistant
Capnocytophaga ochracea
Infection
Authors: Wang Hua-Kung , Chen Yee-Chun , Teng Lee-Jene , Hung Chien-Ching , Chen Mei-Lin , Du Shin-Hei , Pan Hui-Ju , Hsueh Po-Ren , Chang Shan-Chwen
Published: November 2006

Brain abscesses are occasionally associated with a dental source of infection. An unusual case of frontal lobe abscess in a nonimmunocompromised child infected with multidrug-resistant
Capnocytophaga ochracea
is described and confirms the pathogenic potential of this organism to cause human disease in the central nervous system.
Using a Resequencing Microarray as a Multiple Respiratory Pathogen Detection Assay
Authors: Lin Baochuan , Blaney Kate M. , Malanoski Anthony P. , Ligler Adam G. , Schnur Joel M. , Metzgar David , Russell Kevin L. , Stenger David A.
Published: November 2006

Simultaneous testing for detection of infectious pathogens that cause similar symptoms (e.g., acute respiratory infections) is invaluable for patient treatment, outbreak prevention, and efficient use of antibiotic and antiviral agents. In addition, such testing may provide information regarding possible coinfections or induced secondary infections, such as virally induced bacterial infections. Furthermore, in many cases, detection of a pathogen requires more than genus/species-level resolution, since harmful agents (e.g., avian influenza virus) are grouped with other, relatively benign common agents, and for every pathogen, finer resolution is useful to allow tracking of the location and nature of mutations leading to strain variations. In this study, a previously developed resequencing microarray that has been demonstrated to have these capabilities was further developed to provide individual detection sensitivity ranging from 10
1
to 10
3
genomic copies for more than 26 respiratory pathogens while still retaining the ability to detect and differentiate between close genetic neighbors. In addition, the study demonstrated that this system allows unambiguous and reproducible sequence-based strain identification of the mixed pathogens. Successful proof-of-concept experiments using clinical specimens show that this approach is potentially very useful for both diagnostics and epidemic surveillance.
Reassortment and Concerted Evolution inBanana Bunchy Top VirusGenomes
Authors: Hu Jer-Ming , Fu Hui-Chuan , Lin Chia-Hua , Su Hong-Ji , Yeh Hsin-Hung
Published: November 2006

The nanovirusBanana bunchy top virus(BBTV) has six standard components in its genome and occasionally contains components encoding additional Rep (replication initiation protein) genes. Phylogenetic network analysis of coding sequences of DNA 1 and 3 confirmed the two major groups of BBTV, a Pacific and an Asian group, but show evidence of web-like phylogenies for some genes. Phylogenetic analysis of 102 major common regions (CR-Ms) from all six components showed a possible concerted evolution within the Pacific group, which is likely due to recombination in this region. The CR-M of additional Rep genes is close to that of DNA 1 and 2. Comparison of tree topologies constructed with DNA 1 and DNA 3 coding sequences of 14 BBTV isolates showed distinct phylogenetic histories based on Kishino-Hasegawa and Shimodaira-Hasegawa tests. The results of principal component analysis of amino acid and codon usages indicate that DNA 1 and 3 have a codon bias different from that of all other genes of nanoviruses, including all currently known additional Rep genes of BBTV, which suggests a possible ancient genome reassortment event between distinctive nanoviruses.
Heterogeneity of Raft-Type Membrane Microdomains Associated with VP4, the Rotavirus Spike Protein, in Caco-2 and MA 104 Cells
Authors: Delmas Olivier , Breton Michelyne , Sapin Catherine , Le Bivic André , Colard Odile , Trugnan Germain
Published: November 2006

Previous studies have shown that rotavirus virions, a major cause of infantile diarrhea, assemble within small intestinal enterocytes and are released at the apical pole without significant cell lysis. In contrast, for the poorly differentiated kidney epithelial MA 104 cells, which have been used extensively to study rotavirus assembly, it has been shown that rotavirus is released by cell lysis. The subsequent discovery that rotavirus particles associate with raft-type membrane microdomains (RTM) in Caco-2 cells provided a simple explanation for rotavirus polarized targeting. However, the results presented here, together with those recently published by another group, demonstrate that rotavirus also associates with RTM in MA 104 cells, thus indicating that a simple interaction of rotavirus with rafts is not sufficient to explain its apical targeting in intestinal cells. In the present study, we explore the possibility that RTM may have distinct physicochemical properties that may account for the differences observed in the rotavirus cell cycle between MA 104 and Caco-2 cells. We show here that VP4 association with rafts is sensitive to cholesterol extraction by methyl-β-cyclodextrin treatment in MA 104 cells and insensitive in Caco-2 cells. Using the VP4 spike protein as bait, VP4-enriched raft subsets were immunopurified. They contained 10 to 15% of the lipids present in total raft membranes. We found that the nature and proportion of phospholipids and glycosphingolipids were different between the two cell lines. We propose that this raft heterogeneity may support the cell type dependency of virus assembly and release.
Genome Sequence, Full-Length Infectious cDNA Clone, and Mapping of Viral Double-Stranded RNA Accumulation Determinant of Hypovirus CHV1-EP721
Authors: Lin Haiyan , Lan Xiuwan , Liao Hong , Parsley Todd B. , Nuss Donald L. , Chen Baoshan
Published: November 2006

Cryphonectria parasitica
strain EP721 is infected with a strain of hypovirus CHV1, CHV1-EP721, and exhibits typical hypovirulence-associated traits such as reduced pigmentation and reduced asexual sporulation. However, the accumulation of the viral double-stranded RNA (dsRNA) in this hypovirus-infected
C. parasitica
strain is atypically low. We now report the complete nucleotide sequence and construction of a full-length infectious cDNA clone for hypovirus CHV1-EP721. The genome sequence of CHV1-EP721 was determined to be 12,724 bp in length and to share extensive homology with two other hypovirus strains, CHV1-Euro7 and CHV1-EP713, with an average of 99% and 90% identities at the nucleotide level and 99% and 92% identities at the amino acid level, respectively. CHV1-EP721 was successfully introduced into virus-free fungal host strain EP721(-v) by transfection with transcripts derived from a full-length viral cDNA. The transfected strain had a phenotype indistinguishable from that of EP721, and the accumulation of CHV1-EP721 dsRNA in the transfectant was lower than those transfected by CHV1-Euro7 and CHV1-EP713 transcripts. Through the construction of chimeric viruses by domain swapping using infectious cDNA clones of CHV1-EP721, CHV1-EP713, and CHV1-Euro7 hypoviruses, the determinant for the low level of viral dsRNA accumulation in CHV1-EP721 was mapped to the second of two CHV1-EP721 open reading frames (ORFs), ORF B. Further refined swapping of domains within ORF B identified a 2.5-kb coding region between p48 and the polymerase domain of CHV1-EP721 as being responsible for the low viral dsRNA accumulation. Evidence is also provided that low rates of hypovirus transmission through conidial spores correlates with low viral dsRNA accumulation.
Evidence for the Existence of the Loop E Motif of
Potato Spindle Tuber Viroid
In Vivo
Authors: Wang Ying , Zhong Xuehua , Itaya Asuka , Ding Biao
Published: November 2006

RNA motifs comprising nucleotides that interact through non-Watson-Crick base pairing play critical roles in RNA functions, often by serving as the sites for RNA-RNA, RNA-protein, or RNA small ligand interactions. The structures of viral and viroid RNA motifs are studied commonly by in vitro, computational, and mutagenesis approaches. Demonstration of the in vivo existence of a motif will help establish its biological significance and promote mechanistic studies on its functions. By using UV cross-linking and primer extension, we have obtained direct evidence for the in vivo existence of the loop E motif of
Potato spindle tuber viroid
. We present our findings and discuss their biological implications.
Measles Virus Infection of SLAM (CD150) Knockin Mice Reproduces Tropism and Immunosuppression in Human Infection
Authors: Ohno Shinji , Ono Nobuyuki , Seki Fumio , Takeda Makoto , Kura Shinobu , Tsuzuki Teruhisa , Yanagi Yusuke
Published: November 2006

The human signaling lymphocyte activation molecule (SLAM, also called CD150), a regulator of antigen-driven T-cell responses and macrophage functions, acts as a cellular receptor for measles virus (MV), and its V domain is necessary and sufficient for receptor function. We report here the generation of SLAM knockin mice in which the V domain of mouse SLAM was replaced by that of human SLAM. The chimeric SLAM had an expected distribution and normal function in the knockin mice. Splenocytes from the SLAM knockin mice permitted the in vitro growth of a virulent MV strain but not that of the Edmonston vaccine strain. Unlike in vitro infection, MV could grow only in SLAM knockin mice that also lacked the type I interferon receptor (IFNAR). After intraperitoneal or intranasal inoculation, MV was detected in the spleen and lymph nodes throughout the body but not in the thymus. Notably, the virus appeared first in the mediastinal lymph node after intranasal inoculation. Splenocytes from MV-infected IFNAR−/−SLAM knockin mice showed suppression of proliferative responses to concanavalin A. Thus, MV infection of SLAM knockin mice reproduces lymphotropism and immunosuppression in human infection, serving as a useful small animal model for measles.
Normal clinical and ultrasound findings indicate a low risk to sustain jumper’s knee patellar tendinopathy: a longitudinal study on Swedish elite junior volleyball players
Authors: Gisslén Karl , Gyulai Csaba , Nordström Peter , Alfredson Håkan
Published: November 2006

Background:Jumper’s knee patellar tendinopathy is well known to be a common and difficult injury in volleyball. Knowledge about its aetiology and pathogenesis is sparse.

Objective:To prospectively follow clinical status, tendon structure and vascularity in elite junior volleyball players.

Methods:22 volleyball players (44 patellar tendons) beginning their first grade at the Swedish National Centre for high school volleyball were continuously evaluated clinically and by ultrasonography (US) and power Doppler (PD) over the 3 school years.

Results:At inclusion, there were 44 tendons being assessed. Jumper’s knee was diagnosed clinically in eight patellar tendons (seven of eight had structural changes and vascularity on US+PD). There were 27 normal (clinical and US+PD) tendons. At 3 years, there were 36 tendons still being assessed. Four individuals (eight tendons) had been excluded. Jumper’s knee had developed in 2 of 25 (2 were excluded) tendons that were normal (clinical and US+PD) at inclusion. Jumper’s knee (clinical and US+PD) was also present in six tendons.

Conclusions:Normal clinical tests and ultrasound findings at the start indicated a low risk for these elite junior volleyball players to sustain jumper’s knee during three school years with intensive training and playing.
Eccentric training in Achilles tendinopathy: is it harmful to tendon microcirculation?
Authors: Knobloch Karsten
Published: November 2006

Background:Eccentric training has been shown to reduce pain and gain function in patients with chronic Achilles tendinopathy. However, currently no data are available regarding any potential adverse effects of an eccentric training intervention on Achilles tendon microcirculation.

Methods:59 patients (49 (12) years; body mass index 27 (5); 49 mid-portion, 10 chronic insertional tendinopathy) with 64 symptomatic (54 mid-portion, 10 insertional) Achilles tendons were prospectively enrolled. Baseline tendon microcirculation at four distinct tendon positions from the insertion to the proximal mid-portion area was assessed using a laser Doppler system for capillary blood flow, tissue oxygen saturation and postcapillary venous filling pressure. A 12-week daily painful home-based eccentric training regimen was initiated (3×15 repetitions per tendon and day).

Results:Achilles tendon capillary blood flow was significantly reduced at the insertion (by 35%, p = 0.008) and the distal mid-portion area (by 45%, p = 0.015) at 2 mm and by 22% (p = 0.007) and 13% (p = 0.122) at 8 mm tissue depths, respectively. Achilles tendon oxygen saturation was not decreased after the 12-week eccentric training regimen throughout the insertion to the proximal mid-portion area (insertion 72 (13) vs 73 (10), proximal mid-portion 63 (13) vs 62 (11), both NS). Achilles tendon postcapillary venous filling pressures were significantly reduced at the insertion (51 (16) vs 41 (19), p = 0.001) and the distal mid-portion (36 (13) vs 32 (12), p = 0.037) at 2 mm and at the insertion at 8 mm (63 (19) vs 51 (13), p = 0.0001). Pain was reduced from 5.4 (2.1) to 3.6 (2.4; p = 0.001) in the mid-portion and from 6 (2.5) to 3.2 (2.7; p = 0.002) in the insertional tendinopathy group. No Achilles tendon rupture or any interruption during the eccentric training was noted among the 59 patients.

Conclusion:Daily eccentric training for Achilles tendinopathy is a safe and easy measure, with beneficial effects on the microcirculatory tendon levels without any evident adverse effects in both mid-portion and insertional Achilles tendinopathy.
Resistance exercise does not affect the serum concentrations of cell adhesion molecules
Authors: Petridou Anatoli , Chatzinikolaou Athanasios , Fatouros Ioannis , Mastorakos George , Mitrakou Asimina , Chandrinou Helen , Papassotiriou Ioannis , Mougios Vassilis
Published: November 2006

Background:Cell adhesion molecules are proteins expressed on the surface of a variety of cells and mediate the leucocyte response to inflammation. Some of these molecules are released to the plasma as soluble forms, whose presence indicates the degree of vascular endothelial activation or dysfunction. Increased concentrations of soluble adhesion molecules are thought to hamper the immune response and mediate the atherosclerotic inflammatory process. Studies on the effect of exercise on the concentrations of soluble adhesion molecules have almost exclusively used aerobic exercise.

Aim:To assess the effect of resistance exercise on the serum concentrations of five cell adhesion molecules during and immediately after 30 min of exercise in lean and obese participants.

Methods:Fourteen healthy young men (eight lean and six obese) performed 3 sets of 10 resistance exercises with 10–12 repetitions at 70–75% of one repetition maximum in a circuit training fashion. Venous blood samples were drawn at baseline and at the end of the first, second and third sets. The serum concentrations of vascular cell adhesion molecule-1, intercellular cell adhesion molecule-1, E-selectin, P-selectin and L-selectin were measured in a biochip array analyser.

Results:No significant changes were observed in the concentrations of these cell adhesion molecules during exercise, or between lean and obese participants.

Conclusion:Our data indicate that resistance exercise of moderate to high intensity does not affect the serum concentrations of cell adhesion molecules in healthy young lean or obese men, suggesting no considerable negative effect on immune function.
Animal models for the study of tendinopathy
Authors: Warden S J
Published: November 2006

Tendinopathy is a common and significant clinical problem characterised by activity-related pain, focal tendon tenderness and intratendinous imaging changes. Recent histopathological studies have indicated the underlying pathology to be one of tendinosis (degeneration) as opposed to tendinitis (inflammation). Relatively little is known about tendinosis and its pathogenesis. Contributing to this is an absence of validated animal models of the pathology. Animal models of tendinosis represent potential efficient and effective means of furthering our understanding of human tendinopathy and its underlying pathology. By selecting an appropriate species and introducing known risk factors for tendinopathy in humans, it is possible to develop tendon changes in animal models that are consistent with the human condition. This paper overviews the role of animal models in tendinopathy research by discussing the benefits and development of animal models of tendinosis, highlighting potential outcome measures that may be used in animal tendon research, and reviewing current animal models of tendinosis. It is hoped that with further development of animal models of tendinosis, new strategies for the prevention and treatment of tendinopathy in humans will be generated.
EXPRESS PASSENGER TRANSPORT SYSTEM AS A SCALE-FREE NETWORK
Authors: FU BAIBAI , GAO ZIYOU , LIU FASHENG , KONG XIANJUAN
Published: November 2006

An express highway itself is not a scale-free network, while the Express Passenger Transport System (EPTS) on the express highway network has the properties of a small-world and scale-free network. Data analysis based on the observation of the EPTS in Shandong province, China, shows that the EPTS has the properties of scale-free networks and the power exponent λ of the distribution is equal to about 2.1. Based on the scale-free network topology structure of the EPTS network, the construction of the EPTS network will be more efficient and robust.
PHASE FORMATION AND SUPERCONDUCTIVITY OF Fe-TUBE ENCAPSULATED AND VACUUM-ANNEALED MgB2
Authors: SINGH K. P. , AWANA V. P. S. , SHAHABUDDIN MD. , HUSAIN M. , SAXENA R. B. , NIGAM RASHMI , ANSARI M. A. , GUPTA ANURAG , NARAYAN HIMANSHU , HALDER S. K. , KISHAN H.
Published: November 2006

We report optimization of the synthesis parameters viz. heating temperature (TH), and hold time (t hold ) for vacuum-annealed (10-5 Torr) and LN 2 (liquid nitrogen) quenched MgB 2 compound. These are single-phase compounds crystallizing in the hexagonal structure (space group P 6/mmm ) at room temperature. Our XRD results indicated that for phase-pure MgB 2, the TH for 10-5 Torr annealed and LN 2-quenched samples is 750°C. The right stoichiometry i.e., MgB 2 of the compound corresponding to 10-5 Torr and TH of 750°C is found for the hold time (t hold ) of 2.30 hours. With varying t hold from 1–4 hours at fixed TH (750°C) and vacuum (10-5 Torr), the c-lattice parameter decreases first and later increases with t hold (hours) before a near saturation, while the a-lattice parameter first increases and later decreases beyond a t hold of 2.30 hours. The c/a ratio versus t hold plot showed an inverted bell-shaped curve, touching the lowest value of 1.141, which is the reported value for perfect stoichiometry of MgB 2. The optimized stoichimetric MgB 2 compound exhibited superconductivity at 39.2 K with a transition width of 0.6 K. In conclusion, the synthesis parameters for phase pure stoichimetric vacuum-annealed MgB 2 compound are optimized and are compared with widely-reported Ta tube encapsulated samples.
POLARON IN THE SINGLE-WALLED POLAR NANOTUBE
Authors: GUSEINOV N. M. , ALEKPEROV O. Z. , GUSEINOVA S. S.
Published: November 2006

The model of electron gas situated on the two-dimensional continual cylindrical surface is suggested to describe a polaron in the single-walled nanotube made of polar material. The problem on weak-coupling polaron is solved using perturbation theory. Analytical expression for the polaron energy shift of the subband is found in the case of bulk phonon approximation and the case when longitudinal optical (LO) phonons are confined on the cylinder's surface. It is shown that in the second case the polaron effect is negligible.
INVESTIGATION OF THE Si:H FILMS DEPOSITED NEAR THE TRANSITION REGION FOR APPLICATION IN SOLAR CELLS
Authors: LEI QINGSONG , WU ZHIMENG , GENG XINHUA , ZHAO YING , XI JIANPING
Published: November 2006

Hydrogenated silicon thin films (Si:H) have been deposited by using very high-frequency plasma-enhanced chemical vapor deposition (VHF PECVD). The structural, electrical and optical properties of the films were characterized. The transition process and the effect of pressure were studied. Results suggest that a narrow region, in which the transition from microcrystalline to amorphous growth takes place, exists in the regime of silane concentration (SC). This region is influenced by the working pressure (P). At lower pressure, the transition region is shifted to higher SC. Microcrystalline silicon (μ c-Si:H ) thin films deposited near transition region was applied as i-layer to the p-i-n solar cells. An efficiency of about 5.30% was obtained.
Nuclear Receptor Structure: Implications for Function
Authors: Bain David L. , Heneghan Aaron F. , Connaghan-Jones Keith D. , Miura Michael T.
Published: November 2006

Small lipophilic molecules such as steroidal hormones, retinoids, and free fatty acids control many of the reproductive, developmental, and metabolic processes in eukaryotes. The mediators of these effects are nuclear receptor proteins, ligand-activated transcription factors capable of regulating the expression of complex gene networks. This review addresses the structure and structural properties of nuclear receptors, focusing on the well-studied ligand-binding and DNA-binding domains as well as our still-emerging understanding of the largely unstructured N-terminal regions. To emphasize the allosteric interdependence among these subunits, a more detailed inspection of the structural properties of the human progesterone receptor is presented. Finally, this work is placed in the context of developing a quantitative and mechanistic understanding of nuclear receptor function.
ROS and NF-κB but not LXR mediate IL-1β signaling for the downregulation of ATP-binding cassette transporter A1
Authors: Chen Min , Li Wenjing , Wang Nanping , Zhu Yi , Wang Xian
Published: November 2006

ATP-binding cassette transporter A1 (ABCA1), a pivotal regulator of cholesterol efflux from cells to apolipoproteins, plays an important role in cholesterol homeostasis. As an inflammatory factor, IL-1β has been shown to downregulate ABCA1 in macrophages and facilitates foam cell formation. However, the molecular mechanism underlining the downregulated ABCA1 by IL-1β is still elusive. In the present study, we demonstrated that IL-1β downregulated ABCA1 but not ABCG1 at mRNA and protein levels in a time- and dose-dependent manner in THP-1 and A549 cells. IL-1β attenuated ABCA1 promoter activity through an LXR (liver X receptor)-independent pathway, since IL-1β did not alter the expression and activities of LXRα/β, and deletion of the LXR responsive element from the ABCA1 promoter failed to reverse the IL-1β effect. In contrast, NF-κB inhibition by pyrrolidine dithiocarbamate and MG132 prevented the suppression of ABCA1 by IL-1β. Cotransfection with ABCA1 luciferase reporter and the expression plasmids of Rel A decreased ABCA1 promoter activities. An adenovirus expressing NF-κB inhibitor subunit-α inhibited NF-κB activities and also reversed the IL-1β effect at the promoter activity and protein levels of ABCA1. In addition, IL-1β could induce the production of reactive oxygen species (ROS), and N-acetyl-l-cysteine, a scavenger of ROS, reversed the decreased level of ABCA1 induced by IL-1β. H2O2 decreased ABCA1 at the mRNA and protein levels and the promoter activity. Thus our data provide strong evidence that ROS and NF-κB, but not LXR, mediate the IL-1β-induced downregulation of ABCA1 via a novel transcriptional mechanism, which might play an important role of proinflammation in the alteration of lipid metabolism.
Chloride channelopathy in myotonic dystrophy resulting from loss of posttranscriptional regulation for CLCN1
Authors: Lueck John D. , Lungu Codrin , Mankodi Ami , Osborne Robert J. , Welle Stephen L. , Dirksen Robert T. , Thornton Charles A.
Published: November 2006

Transmembrane chloride ion conductance in skeletal muscle increases during early postnatal development. A transgenic mouse model of myotonic dystrophy type 1 (DM1) displays decreased sarcolemmal chloride conductance. Both effects result from modulation of chloride channel 1 (CLCN1) expression, but the respective contributions of transcriptional vs. posttranscriptional regulation are unknown. Here we show that alternative splicing of CLCN1 undergoes a physiological splicing transition during the first 3 wk of postnatal life in mice. During this interval, there is a switch to production of CLCN1 splice products having an intact reading frame, an upregulation of CLCN1 mRNA encoding full-length channel protein, and an increase of CLCN1 function, as determined by patch-clamp analysis of single muscle fibers. In a transgenic mouse model of DM1, however, the splicing transition does not occur, CLCN1 channel function remains low throughout the postnatal interval, and muscle fibers display myotonic discharges. Thus alternative splicing is a posttranscriptional mechanism regulating chloride conductance during muscle development, and the chloride channelopathy in a transgenic mouse model of DM1 results from a failure to execute a splicing transition for CLCN1.
TGF-β-regulated collagen type I accumulation: role of Src-based signals
Authors: Mishra Rangnath , Zhu Ling , Eckert Richard L. , Simonson Michael S.
Published: November 2006

Transforming growth factor-β (TGF-β) stimulates myofibroblast transdifferentiation, leading to type I collagen accumulation and fibrosis. We investigated the function of Src in TGF-β-induced collagen I accumulation. In human mesangial cells, PTyr416 Src (activated Src) was 3.3-fold higher in TGF-β-treated cells than in controls. Src activation by TGF-β was blocked by rottlerin and by a dominant negative mutant of protein kinase Cδ (PKCδ), showing that TGF-β activates Src by a PKCδ-based mechanism. Pharmacological inhibitors and a dominant negative Src mutant prevented the increase in collagen type I secretion in cells exposed to TGF-β. Similarly, on-target Src small interference RNA (siRNA) prevented type I collagen secretion in response to TGF-β, but off-target siRNA complexes had no effect. It is well established in mesangial cells that upregulation of type I collagen by TGF-β requires extracellular signal-regulated kinase 1/2 (ERK1/2), and we found that activation of ERK1/2 by TGF-β requires Src. In conclusion, these results suggest that stimulation of collagen type I secretion by TGF-β requires a PKCδ-Src-ERK1/2 signaling motif.
Impact of Type 2 diabetes and aging on cardiomyocyte function and O-linked N-acetylglucosamine levels in the heart
Authors: Fülöp Norbert , Mason Meredith M. , Dutta Kaushik , Wang Peipei , Davidoff Amy J. , Marchase Richard B. , Chatham John C.
Published: November 2006

Increased levels of O-linked attachment of N-acetylglucosamine ( O-GlcNAc) on nucleocytoplasmic proteins are implicated in the development of diabetic cardiomyopathy and are regulated by O-GlcNAc transferase (OGT) expression and its substrate UDP-GlcNAc. Therefore, the goal of this study was to determine whether the development of diabetes in the Zucker diabetic fatty (ZDF) rat, a model of Type 2 diabetes, results in defects in cardiomyocyte mechanical function and, if so, whether this is associated with increased levels of O-GlcNAc and increased OGT expression. Six-week-old ZDF rats were hyperinsulinemic but normoglycemic, and there were no differences in cardiomyocyte mechanical function, UDP-GlcNAc, O-GlcNAc, or OGT compared with age-matched lean control rats. Cardiomyocytes isolated from 22-wk-old hyperglycemic ZDF rats exhibited significantly impaired relaxation, compared with both age-matched lean control and 6-wk-old ZDF groups. There was also a significant increase in O-GlcNAc levels in high-molecular-mass proteins in the 22-wk-old ZDF group compared with age-matched lean control and 6-wk-old ZDF groups; this was associated with increased UDP-GlcNAc levels but not increased OGT expression. Surprisingly, there was a significant decrease in overall O-GlcNAc levels between 6 and 22 wk of age in lean, ZDF, and Sprague-Dawley rats that was associated with decreased OGT expression. These results support the notion that an increase in O-GlcNAc on specific proteins may contribute to impaired cardiomyocyte function in diabetes. However, this study also indicates that in the heart the level of O-GlcNAc on proteins appears to be differentially regulated by age and diabetes.
Phosphorothioate oligonucleotides reduce mitochondrial outer membrane permeability to ADP
Authors: Tan Wenzhi , Lai Johnathan C. , Miller Paul , Stein C. A. , Colombini Marco
Published: November 2006

G3139, an antisense Bcl-2 phosphorothioate oligodeoxyribonucleotide, induces apoptosis in melanoma and other cancer cells. This apoptosis happens before and in the absence of the downregulation of Bcl-2 and thus seems to be Bcl-2-independent. Binding of G3139 to mitochondria and its ability to close voltage-dependent anion-selective channel (VDAC) have led to the hypothesis that G3139 acts, in part, by interacting with VDAC channels in the mitochondrial outer membrane ( 21 ). In this study, we demonstrate that G3139 is able to reduce the mitochondrial outer membrane permeability to ADP by a factor of 6 or 7 with a Ki between 0.2 and 0.5 μM. Because VDAC is responsible for this permeability, this result strengthens the aforesaid hypothesis. Other mitochondrial respiration components are not affected by [G3139] up to 1 μM. Higher levels begin to inhibit respiration rates, decrease light scattering and increase uncoupled respiration. These results agree with accumulating evidence that VDAC closure favors cytochrome c release. The speed of this effect (within 10 min) places it early in the apoptotic cascade with cytochrome c release occurring at later times. Other phosphorothioate oligonucleotides are also able to induce VDAC closure, and there is some length dependence. The phosphorothioate linkages are required to induce the reduction of outer membrane permeability. At levels below 1 μM, phosphorothioate oligonucleotides are the first specific tools to restrict mitochondrial outer membrane permeability.
Interleukin-15 responses to aging and unloading-induced skeletal muscle atrophy
Authors: Pistilli Emidio E. , Siu Parco M. , Alway Stephen E.
Published: November 2006

Interleukin-15 (IL-15) mRNA is constitutively expressed in skeletal muscle. Although IL-15 has proposed hypertrophic and anti-apoptotic roles in vitro, its role in skeletal muscle cells in vivo is less clear. The purpose of this study was to determine if skeletal muscle aging and unloading, two conditions known to promote muscle atrophy, would alter basal IL-15 expression in skeletal muscle. We hypothesized that IL-15 mRNA expression would increase as a result of both aging and muscle unloading and that muscle would express the mRNA for a functional trimeric IL-15 receptor (IL-15R). Two models of unloading were used in this study: hindlimb suspension (HS) in rats and wing unloading in quail. The absolute muscle wet weight of plantaris and soleus muscles from aged rats was significantly less when compared with muscles from young adult rats. Although 14 days of HS resulted in reduced muscle mass of plantaris and soleus muscles from young adult animals, this effect was not observed in muscles from aged animals. A significant aging times unloading interaction was observed for IL-15 mRNA in both rat soleus and plantaris muscles. Patagialis (PAT) muscles from aged quail retained a significant 12 and 6% of stretch-induced hypertrophy after 7 and 14 days of unloading, respectively. PAT muscles from young quail retained 15% hypertrophy at 7 days of unloading but regressed to control levels following 14 days of unloading. A main effect of age was observed on IL-15 mRNA expression in PAT muscles at 14 days of overload, 7 days of unloading, and 14 days of unloading. Skeletal muscle also expressed the mRNAs for a functional IL-15R composed of IL-15Rα, IL-2/15R-β, and -γc. Based on these data, we speculate that increases in IL-15 mRNA in response to atrophic stimuli may be an attempt to counteract muscle mass loss in skeletal muscles of old animals. Additional research is warranted to determine the importance of the IL-15/IL-15R system to counter muscle wasting.
Modifications of cellular responses to lysophosphatidic acid and platelet-activating factor by plasma gelsolin
Authors: Osborn Teresia M. , Dahlgren Claes , Hartwig John H. , Stossel Thomas P.
Published: November 2006

Gelsolin is a highly conserved intracellular actin-binding protein with an extracellular isoform, plasma gelsolin (pGSN). Blood concentrations of pGSN decrease in response to diverse tissue injuries. Depletion of pGSN to critical levels precedes and often predicts complications of injuries such as lung permeability changes and death. Administration of recombinant pGSN ameliorates such complications and reduces mortality in animal models. One proposed mechanism for pGSN's protective effects is that it inhibits inflammatory mediators generated during primary injuries, since pGSN binds bioactive mediators, including lysophospatidic acid (LPA) and endotoxin in vitro. However, no direct evidence in support of this hypothesis has been available. Here we show that recombinant pGSN modestly inhibited LPA-induced P-selectin upregulation by human platelets in the presence of albumin ( P < 0.0001). However, physiologically relevant pGSN concentrations inhibit platelet-activating factor (PAF)-mediated P-selectin expression by up to 77% ( P < 0.0001). pGSN also markedly inhibited PAF-induced superoxide anion (O2−) production of human peripheral neutrophils (PMN) in a concentration-dependent manner ( P < 0.0001). A phospholipid-binding peptide derived from pGSN (QRLFQVKGRR) also inhibited PAF-mediated O2−generation ( P = 0.024). Therefore, pGSN interferes with PAF- and LPA-induced cellular activation in vitro, suggesting a mechanism for the protective role of pGSN in vivo.