bluuebunny/crossref_metadata_2025 huggingface dataset:
The United States Supreme Court and Health Law
Authors: Ruger Theodore W.
Published: November 2006

Almost everyone involved in the legal profession today is aware of the wide, and perhaps insurmountable, chasm between the scholarly research that takes place in elite law schools and the actual work of practicing lawyers and judges. To a greater extent than other academic professions like medicine and public health, law professors too often have little to say to working lawyers and judges, even those judges on the U.S. Supreme Court. Perhaps this has been the case from the beginning, but the gap appears more dramatic in recent decades, as legal scholarship has departed from traditional doctrinal analysis and moved in more interdisciplinary and abstract theoretical directions.
Response to Comment on Chong
et al
. on Diabetes Reversal in NOD Mice
Authors: Chong Anita S. , Shen Jikun , Tao Jing , Yin Dengping , Kuznetsov Andrey , Hara Manami , Philipson Louis H.
Published: November 2006

We failed to detect transdifferentiation of spleen cells into β cells following diabetes reversal in nonobese diabetic (NOD) mice, thus contradicting a key finding of a 2003 report. We respond to Faustman
et al
. by justifying the use of mouse insulin promoter–green fluorescent protein transgenic mice as an appropriate system for detecting spleen-derived β cells in the islets of cured NOD mice.
Predictive Codes for Forthcoming Perception in the Frontal Cortex
Authors: Summerfield Christopher , Egner Tobias , Greene Matthew , Koechlin Etienne , Mangels Jennifer , Hirsch Joy
Published: November 2006

Incoming sensory information is often ambiguous, and the brain has to make decisions during perception. “Predictive coding” proposes that the brain resolves perceptual ambiguity by anticipating the forthcoming sensory environment, generating a template against which to match observed sensory evidence. We observed a neural representation of predicted perception in the medial frontal cortex, while human subjects decided whether visual objects were faces or not. Moreover, perceptual decisions about faces were associated with an increase in top-down connectivity from the frontal cortex to face-sensitive visual areas, consistent with the matching of predicted and observed evidence for the presence of faces.
A Post-Perovskite Lens and
D''
Heat Flux Beneath the Central Pacific
Authors: Lay Thorne , Hernlund John , Garnero Edward J. , Thorne Michael S.
Published: November 2006

Temperature gradients in a low-shear-velocity province in the lowermost mantle (
D″
region) beneath the central Pacific Ocean were inferred from the observation of a rapid
S
-wave velocity increase overlying a rapid decrease. These paired seismic discontinuities are attributed to a phase change from perovskite to post-perovskite and then back to perovskite as the temperature increases with depth. Iron enrichment could explain the occurrence of post-perovskite several hundred kilometers above the core-mantle boundary in this warm, chemically distinct province. The double phase-boundary crossing directly constrains the lowermost mantle temperature gradients. Assuming a standard but unconstrained choice of thermal conductivity, the regional core-mantle boundary heat flux (∼85 ± 25 milliwatts per square meter), comparable to the average at Earth's surface, was estimated, along with a lower bound on global core-mantle boundary heat flow in the range of 13 ± 4 terawatts. Mapped velocity-contrast variations indicate that the lens of post-perovskite minerals thins and vanishes over 1000 kilometers laterally toward the margin of the chemical distinct region as a result of a ∼500-kelvin temperature increase.
Evolutionary History of
Salmonella
Typhi
Authors: Roumagnac Philippe , Weill François-Xavier , Dolecek Christiane , Baker Stephen , Brisse Sylvain , Chinh Nguyen Tran , Le Thi Anh Hong , Acosta Camilo J. , Farrar Jeremy , Dougan Gordon , Achtman Mark
Published: November 2006

For microbial pathogens, phylogeographic differentiation seems to be relatively common. However, the neutral population structure of
Salmonella enterica
serovar Typhi reflects the continued existence of ubiquitous haplotypes over millennia. In contrast, clinical use of fluoroquinolones has yielded at least 15 independent
gyrA
mutations within a decade and stimulated clonal expansion of haplotype H58 in Asia and Africa. Yet, antibiotic-sensitive strains and haplotypes other than H58 still persist despite selection for antibiotic resistance. Neutral evolution in Typhi appears to reflect the asymptomatic carrier state, and adaptive evolution depends on the rapid transmission of phenotypic changes through acute infections.
Nutrient Amendments in Soil DNA Stable Isotope Probing Experiments Reduce the Observed Methanotroph Diversity
Authors: Cébron Aurélie , Bodrossy Levente , Stralis-Pavese Nancy , Singer Andrew C. , Thompson Ian P. , Prosser James I. , Murrell J. Colin
Published: November 2006

Stable isotope probing (SIP) can be used to analyze the active bacterial populations involved in a process by incorporating
13
C-labeled substrate into cellular components such as DNA. Relatively long incubation times are often used with laboratory microcosms in order to incorporate sufficient
13
C into the DNA of the target organisms. Addition of nutrients can be used to accelerate the processes. However, unnatural concentrations of nutrients may artificially change bacterial diversity and activity. In this study, methanotroph activity and diversity in soil was examined during the consumption of
13
CH
4
with three DNA-SIP experiments, using microcosms with natural field soil water conditions, the addition of water, and the addition of mineral salts solution. Methanotroph population diversity was studied by targeting 16S rRNA and
pmoA
genes. Clone library analyses, denaturing gradient gel electrophoresis fingerprinting, and
pmoA
microarray hybridization analyses were carried out. Most methanotroph diversity (type I and type II methanotrophs) was observed in nonamended SIP microcosms. Although this treatment probably best reflected the in situ environmental conditions, one major disadvantage of this incubation was that the incorporation of
13
CH
4
was slow and some cross-feeding of
13
C occurred, thereby leading to labeling of nonmethanotroph microorganisms. Conversely, microcosms supplemented with mineral salts medium exhibited rapid consumption of
13
CH
4
, resulting in the labeling of a less diverse population of only type I methanotrophs. DNA-SIP incubations using water-amended microcosms yielded faster incorporation of
13
C into active methanotrophs while avoiding the cross-feeding of
13
C.
Green Tea Polyphenols Function as Prooxidants To Activate Oxidative-Stress-Responsive Transcription Factors in Yeasts
Authors: Maeta Kazuhiro , Nomura Wataru , Takatsume Yoshifumi , Izawa Shingo , Inoue Yoshiharu
Published: November 2006

Epigallocatechin gallate (EGCG) is the most abundant polyphenolic flavonoid in green tea. Catechin and its derivatives, including EGCG, are widely believed to function as antioxidants. Here we demonstrate that both EGCG and green tea extract (GTE) cause oxidative stress-related responses in the budding yeast
Saccharomyces cerevisiae
and the fission yeast
Schizosaccharomyces pombe
under weak alkaline conditions in terms of the activation of oxidative-stress-responsive transcription factors. GTE as well as EGCG induced the nuclear localization of Yap1 in
S. cerevisiae
, which was repressed by the addition of catalase but not by the addition of superoxide dismutase. The same phenomena were observed for the nucleocytoplasmic localization of Msn2 in
S. cerevisiae
and Pap1, a Yap1 homologue, in
S. pombe
. The formation of intramolecular disulfide bonds has been proposed to be crucial for the H
2
O
2
-induced nuclear localization of Yap1, and we verified the importance of cysteine residues of Yap1 in response to EGCG and GTE. Additionally, we show that EGCG and GTE produce H
2
O
2
in a weak alkaline medium. Finally, we conclude that tea polyphenols are able to act as prooxidants to cause a response to oxidative stress in yeasts under certain conditions.
Inhibitory Impact of Bifidobacteria on the Transfer of β-Lactam Resistance among
Enterobacteriaceae
in the Gnotobiotic Mouse Digestive Tract
Authors: Moubareck C. , Lecso M. , Pinloche E. , Butel M. J. , Doucet-Populaire F.
Published: November 2006

While looking for new means to limit the dissemination of antibiotic resistance, we evaluated the role of potentially probiotic bifidobacteria on the transfer of resistance genes between enterobacteria. Transfers of
bla
genes encoding extended-spectrum β-lactamases (SHV-5 and CTX-M-15) were studied in the absence or presence of bifidobacteria. In vitro, transfer frequencies of these
bla
genes decreased significantly in the presence of three of five tested strains, i.e.,
Bifidobacterium longum
CUETM-89-215,
Bifidobacterium bifidum
CIP-56.7T, and
Bifidobacterium pseudocatenulatum
CIP-104168T. Four transfer experiments were conducted in the digestive tract of gnotobiotic mice, the first three observing the effect of
B. longum
CUETM-89-215,
B. bifidum
CIP-56.7T, and
B. pseudocatenulatum
CIP-104168T on
bla
SHV-5
transfer and the fourth experiment studying the effect of
B. bifidum
CIP-56.7T on
bla
CTX-M-15
transfer. These experiments revealed significant decreases in the transconjugant levels (up to 3 logs) in mice having received
B. bifidum
CIP-56.7T or
B. pseudocatenulatum
CIP-104168T compared to control mice. Bifidobacteria appear to have an inhibitory impact on the transfer of antibiotic resistance genes. The inhibitory effect is associated to specific bifidobacterial strains and may be related to the production of thermostable metabolites by these strains.
Transcriptional and Metabolic Responses of
Bacillus subtilis
to the Availability of Organic Acids: Transcription Regulation Is Important but Not Sufficient To Account for Metabolic Adaptation
Authors: Schilling Oliver , Frick Oliver , Herzberg Christina , Ehrenreich Armin , Heinzle Elmar , Wittmann Christoph , Stülke Jörg
Published: November 2006

The soil bacterium
Bacillus subtilis
can use sugars or organic acids as sources of carbon and energy. These nutrients are metabolized by glycolysis, the pentose phosphate pathway, and the Krebs citric acid cycle. While the response of
B. subtilis
to the availability of sugars is well understood, much less is known about the changes in metabolism if organic acids feeding into the Krebs cycle are provided. If
B. subtilis
is supplied with succinate and glutamate in addition to glucose, the cells readjust their metabolism as determined by transcriptome and metabolic flux analyses. The portion of glucose-6-phosphate that feeds into the pentose phosphate pathway is significantly increased in the presence of organic acids. Similarly, important changes were detected at the level of pyruvate and acetyl coenzyme A (acetyl-CoA). In the presence of organic acids, oxaloacetate formation is strongly reduced, whereas the formation of lactate is significantly increased. The
alsSD
operon required for acetoin formation is strongly induced in the presence of organic acids; however, no acetoin formation was observed. The recently discovered phosphorylation of acetolactate decarboxylase may provide an additional level of control of metabolism. In the presence of organic acids, both types of analyses suggest that acetyl-CoA was catabolized to acetate rather than used for feeding the Krebs cycle. Our results suggest that future work has to concentrate on the posttranslational mechanisms of metabolic regulation.
Antibiotic Resistances of Starter and Probiotic Strains of Lactic Acid Bacteria
Authors: Hummel Anja S. , Hertel Christian , Holzapfel Wilhelm H. , Franz Charles M. A. P.
Published: November 2006

The antibiotic resistances of 45 lactic acid bacteria strains belonging to the genera
Lactobacillus
,
Streptococcus
,
Lactococcus
,
Pediococcus
, and
Leuconostoc
were investigated. The objective was to determine antibiotic resistances and to verify these at the genetic level, as is currently suggested by the European “qualified presumption of safety” safety evaluation system for industrial starter strains. In addition, we sought to pinpoint possible problems in resistance determinations. Primers were used to PCR amplify genes involved in β-lactam antibiotic, chloramphenicol, tetracycline, and erythromycin resistance. The presence of ribosomal protection protein genes and the
ermB
gene was also determined by using a gene probe. Generally, the incidences of erythromycin, chloramphenicol, tetracycline, or β-lactam resistances in this study were low (<7%). In contrast, aminoglycoside (gentamicin and streptomycin) and ciprofloxacin resistances were higher than 70%, indicating that these may constitute intrinsic resistances. The genetic basis for ciprofloxacin resistance could not be verified, since no mutations typical of quinolone resistances were detected in the quinolone determining regions of the
parC
and
gyrA
genes. Some starter strains showed low-level ampicillin, penicillin, chloramphenicol, and tetracycline resistances, but no known resistance genes could be detected. Although some strains possessed the
cat
gene, none of these were phenotypically resistant to chloramphenicol. Using reverse transcription-PCR, these
cat
genes were shown to be silent under both inducing and noninducing conditions. Only
Lactobacillus salivarius
BFE 7441 possessed an
ermB
gene, which was encoded on the chromosome and which could not be transferred in filter-mating experiments. This study clearly demonstrates problems encountered with resistance testing, in that the breakpoint values are often inadequately identified, resistance genes may be present but silent, and the genetic basis and associated resistance mechanisms toward some antibiotics are still unknown.
Self-Splicing of the Bacteriophage T4 Group I Introns Requires Efficient Translation of the Pre-mRNA In Vivo and Correlates with the Growth State of the Infected Bacterium
Authors: Sandegren Linus , Sjöberg Britt-Marie
Published: November 2006

Bacteriophage T4 contains three self-splicing group I introns in genes in de novo deoxyribonucleotide biosynthesis (in
td
, coding for thymidylate synthase and in
nrdB
and
nrdD
, coding for ribonucleotide reductase). Their presence in these genes has fueled speculations that the introns are retained within the phage genome due to a possible regulatory role in the control of de novo deoxyribonucleotide synthesis. To study whether sequences in the upstream exon interfere with proper intron folding and splicing, we inhibited translation in T4-infected bacteria as well as in bacteria containing recombinant plasmids carrying the
nrdB
intron. Splicing was strongly reduced for all three T4 introns after the addition of chloramphenicol during phage infection, suggesting that the need for translating ribosomes is a general trait for unperturbed splicing. The splicing of the cloned
nrdB
intron was markedly reduced in the presence of chloramphenicol or when translation was hindered by stop codons inserted in the upstream exon. Several exon regions capable of forming putative interactions with
nrdB
intron sequences were identified, and the removal or mutation of these exon regions restored splicing efficiency in the absence of translation. Interestingly, splicing of the cloned
nrdB
intron was also reduced as cells entered stationary phase and splicing of all three introns was reduced upon the T4 infection of stationary-phase bacteria. Our results imply that conditions likely to be frequently encountered by natural phage populations may limit the self-splicing efficiency of group I introns. This is the first time that environmental effects on bacterial growth have been linked to the regulation of splicing of phage introns.
Novel Type IV Secretion System Involved in Propagation of Genomic Islands
Authors: Juhas Mario , Crook Derrick W. , Dimopoulou Ioanna D. , Lunter Gerton , Harding Rosalind M. , Ferguson David J. P. , Hood Derek W.
Published: November 2006

Type IV secretion systems (T4SSs) mediate horizontal gene transfer, thus contributing to genome plasticity, evolution of infectious pathogens, and dissemination of antibiotic resistance and other virulence traits. A gene cluster of theHaemophilus influenzaegenomic island ICEHin1056has been identified as a T4SS involved in the propagation of genomic islands. This T4SS is novel and evolutionarily distant from the previously described systems. Mutation analysis showed that inactivation of key genes of this system resulted in a loss of phenotypic traits provided by a T4SS. Seven of 10 mutants with a mutation in this T4SS did not express the type IV secretion pilus. Correspondingly, disruption of the genes resulted in up to 100,000-fold reductions in conjugation frequencies compared to those of the parent strain. Moreover, the expression of this T4SS was found to be positively regulated by one of its components, thetfc24gene. We concluded that this gene cluster represents a novel family of T4SSs involved in propagation of genomic islands.
Cyclohexa-1,5-Diene-1-Carbonyl-Coenzyme A (CoA) Hydratases of
Geobacter metallireducens
and
Syntrophus aciditrophicus
: Evidence for a Common Benzoyl-CoA Degradation Pathway in Facultative and Strict Anaerobes
Authors: Peters Franziska , Shinoda Yoshifumi , McInerney Michael J. , Boll Matthias
Published: November 2006

In the denitrifying bacterium
Thauera aromatica
, the central intermediate of anaerobic aromatic metabolism, benzoyl-coenzyme A (CoA), is dearomatized by the ATP-dependent benzoyl-CoA reductase to cyclohexa-1,5-diene-1-carbonyl-CoA (dienoyl-CoA). The dienoyl-CoA is further metabolized by a series of β-oxidation-like reactions of the so-called benzoyl-CoA degradation pathway resulting in ring cleavage. Recently, evidence was obtained that obligately anaerobic bacteria that use aromatic growth substrates do not contain an ATP-dependent benzoyl-CoA reductase. In these bacteria, the reactions involved in dearomatization and cleavage of the aromatic ring have not been shown, so far. In this work, a characteristic enzymatic step of the benzoyl-CoA pathway in obligate anaerobes was demonstrated and characterized. Dienoyl-CoA hydratase activities were determined in extracts of
Geobacter metallireducens
(iron reducing),
Syntrophus aciditrophicus
(fermenting), and
Desulfococcus multivorans
(sulfate reducing) cells grown with benzoate. The benzoate-induced genes putatively coding for the dienoyl-CoA hydratases in the benzoate degraders
G. metallireducens
and
S. aciditrophicus
were heterologously expressed and characterized. Both gene products specifically catalyzed the reversible hydration of dienoyl-CoA to 6-hydroxycyclohexenoyl-CoA (

K
m

, 80 and 35 μM;
V
max
, 350 and 550 μmol min
−1
mg
−1
, respectively). Neither enzyme had significant activity with cyclohex-1-ene-1-carbonyl-CoA or crotonyl-CoA. The results suggest that benzoyl-CoA degradation proceeds via dienoyl-CoA and 6-hydroxycyclohexanoyl-CoA in strictly anaerobic bacteria. The steps involved in dienoyl-CoA metabolism appear identical in all nonphotosynthetic anaerobic bacteria, although totally different benzene ring-dearomatizing enzymes are present in facultative and obligate anaerobes.
Agreement between the AMPLICOR Human Papillomavirus Test and the Hybrid Capture 2 Assay in Detection of High-Risk Human Papillomavirus and Diagnosis of Biopsy-Confirmed High-Grade Cervical Disease
Authors: Carozzi Francesca , Bisanzi Simonetta , Sani Cristina , Zappa Marco , Cecchini Silvia , Ciatto Stefano , Confortini Massimo
Published: November 2006

The AMPLICOR HPV test (AMP) and the Hybrid Capture 2 assay (HC2) detect 13 high-risk human papillomavirus (HR-HPV) types. Evaluation of comparative performance with clinical samples is needed to allow informed implementation of AMP into clinical practice. AMP was used (i) to assess the prevalence of HR-HPV in 1,032 samples of known cytology, HC2 status, and/or confirmed histology; (ii) to determine agreement between AMP and HC2; (iii) to evaluate the clinical sensitivity and specificity for detecting HR-HPV; and (iv) to detect the presence of biopsy-confirmed high-grade cervical intraepithelial neoplasia. The prevalence of HR-HPV was 39.3% and 45.6% by AMP and HC2, respectively. Overall agreement was 89.2% (kappa value, 0.78). Of 509 HR-HPV-negative specimens by HC2, 488 (95.9%) were AMP negative. Of 427 HR-HPV-positive specimens by HC2, 347 (81.2%) were AMP positive. In comparing the ability to detect high-grade squamous intraepithelial lesions (HSIL), the two tests were positive for all HSIL samples. Both tests performed similarly on CIN2+ samples (clinical sensitivities were 96.7% and 97.8%, respectively, for AMP and HC2). The clinical specificities of AMP and HC2 were comparable (54.9% versus 51.6%;
P
= 0.18). Genotyping of 20 HC2-negative/AMP-positive cases using alternative technologies revealed target HR genotypes in 63.1% of cases and low-risk types in 15.7% of cases, while 21% of cases were negative. In conclusion, AMP provides a viable alternative to HC2, with good agreement for samples with high-grade cytology and similar sensitivity in detecting CIN2+ lesions.
Detection of Human Bocavirus in Canadian Children in a 1-Year Study
Authors: Bastien Nathalie , Chui Natalie , Robinson Joan L. , Lee Bonita E. , Dust Kerry , Hart Laura , Li Yan
Published: November 2006

Human bocavirus was detected by PCR in 65 (5.1%) of 1,265 respiratory specimens collected in 2002 and 2003 from the Stollery Children's Hospital from children <17 years of age. The spectrum of illness included upper respiratory infection, croup, bronchiolitis, and pneumonia with a prominence of cough and fever.
Strain Typing and Determination of Population Structure ofCandida kruseiby Multilocus Sequence Typing
Authors: Jacobsen Mette D. , Gow Neil A. R. , Maiden Martin C. J. , Shaw Duncan J. , Odds Frank C.
Published: November 2006

A multilocus sequence typing (MLST) scheme forCandida kruseiwas devised, based on sequencing of six gene fragments of the species. The existence of heterozygous results for each of the six fragments sequenced confirms thatC. kruseiis diploid for at least part of its genome. TheC. kruseiMLST scheme had a discriminatory index of 0.998, making this system ideal for strain typing ofC. kruseiclinical isolates. MLST data for 122 independentC. kruseiisolates from a range of geographical sources were analyzed by eBURST,structure, and the unweighted-pair group method using average linkages to derive a population structure comprising four subtype strain clusters. There was no evidence of geographical associations with particular subtypes. Data for pairs of isolates from seven patients showed that each patient was colonized and/or infected with strain types that were indistinguishable by MLST. TheC. kruseiMLST database can be accessed online athttp://pubmlst.org/ckrusei/.
Magnetic Silica Extraction for Low-Viremia Human Immunodeficiency Virus Type 1 Genotyping
Authors: McClernon D. R. , Ramsey E. , StClair M.
Published: November 2006

Nucleic acid extraction and human immunodeficiency virus type 1 (HIV-1) genotyping using the NucliSens miniMAG platform and the TruGene HIV-1 genotyping kit gave HIV-1 sequence data from HIV-1-negative plasma spiked with 100 copies/ml reference HIV-1 RNA and from low-viremia clinical samples (<500 copies/ml) without the need for ultracentrifugation or nested second-round PCR.
Interaction between a 54-Kilodalton Mammalian Cell Surface Protein and Cowpea Mosaic Virus
Authors: Koudelka Kristopher J. , Rae Chris S. , Gonzalez Maria J. , Manchester Marianne
Published: November 2006

Cowpea mosaic virus (CPMV), a plant virus that is a member of the picornavirus superfamily, is increasingly being used for nanotechnology applications, including material science, vascular imaging, vaccine development, and targeted drug delivery. For these applications, it is critical to understand the in vivo interactions of CPMV within the mammalian system. Although the bioavailability of CPMV in the mouse has been demonstrated, the specific interactions between CPMV and mammalian cells need to be characterized further. Here we demonstrate that although the host range for replication of CPMV is confined to plants, mammalian cells nevertheless bind and internalize CPMV in significant amounts. This binding is mediated by a conserved 54-kDa protein found on the plasma membranes of both human and murine cell lines. Studies using a deficient cell line, deglycosidases, and glycosylation inhibitors showed that the CPMV binding protein (CPMV-BP) is not glycosylated. A possible 47-kDa isoform of the CPMV-BP was also detected in the organelle and nuclear subcellular fraction prepared from murine fibroblasts. Further characterization of CPMV-BP is important to understand how CPMV is trafficked through the mammalian system and may shed light on how picornaviruses may have evolved between plant and animal hosts.
Proteasome-Independent Major Histocompatibility Complex Class I Cross-Presentation Mediated by Papaya Mosaic Virus-Like Particles Leads to Expansion of Specific Human T Cells
Authors: Leclerc Denis , Beauseigle Diane , Denis Jérome , Morin Hélène , Paré Christine , Lamarre Alain , Lapointe Réjean
Published: November 2006

The development of versatile vaccine platforms is a priority that is recognized by health authorities worldwide; such platforms should induce both arms of the immune system, the humoral and cytotoxic-T-lymphocyte responses. In this study, we have established that a vaccine platform based on the coat protein of papaya mosaic virus (PapMV CP), previously shown to induce a humoral response, can induce major histocompatibility complex (MHC) class I cross-presentation of HLA-A*0201 epitopes from gp100, a melanoma antigen, and from influenza virus M1 matrix protein. PapMV proteins were able to assemble into stable virus-like particles (VLPs) in a crystalline and repetitive structure. When we pulsed HLA-A*0201
+
antigen-presenting cells (APCs) with the recombinant PapMV FLU or gp100, we noted that antigen-specific CD8
+
T cells were highly reactive to these APCs, demonstrating that the epitope from the VLPs were processed and loaded on the MHC class I complex. APCs were preincubated with two different proteasome inhibitors, which did not affect the efficiency of peptide presentation on MHC class I. Classical presentation from an endogenous antigen was abolished in the same conditions. Clearly, antigen presentation mediated by the PapMV system was proteasome independent. Finally, PapMV-pulsed APCs had the capacity to expand highly avid antigen-specific T cells against the influenza virus M1 HLA-A*0201 epitope when cocultured with autologous peripheral blood mononuclear cells. This study demonstrates the potential of PapMV for MHC class I cross-presentation and for the expansion of human antigen-specific T cells. It makes VLPs from PapMV CP a very attractive platform to trigger cellular responses for vaccine development against chronic infectious diseases and cancers.
IκB Kinase Subunits α and γ Are Required for Activation of NF-κB and Induction of Apoptosis by Mammalian Reovirus
Authors: Hansberger Mark W. , Campbell Jacquelyn A. , Danthi Pranav , Arrate Pia , Pennington Kevin N. , Marcu Kenneth B. , Ballard Dean W. , Dermody Terence S.
Published: November 2006

Reoviruses induce apoptosis both in cultured cells and in vivo. Apoptosis plays a major role in the pathogenesis of reovirus encephalitis and myocarditis in infected mice. Reovirus-induced apoptosis is dependent on the activation of transcription factor NF-κB and downstream cellular genes. To better understand the mechanism of NF-κB activation by reovirus, NF-κB signaling intermediates under reovirus control were investigated at the level of Rel, IκB, and IκB kinase (IKK) proteins. We found that reovirus infection leads initially to nuclear translocation of p50 and RelA, followed by delayed mobilization of c-Rel and p52. This biphasic pattern of Rel protein activation is associated with the degradation of the NF-κB inhibitor IκBα but not the structurally related inhibitors IκBβ or IκBε. Using IKK subunit-specific small interfering RNAs and cells deficient in individual IKK subunits, we demonstrate that IKKα but not IKKβ is required for reovirus-induced NF-κB activation and apoptosis. Despite the preferential usage of IKKα, both NF-κB activation and apoptosis were attenuated in cells lacking IKKγ/Nemo, an essential regulatory subunit of IKKβ. Moreover, deletion of the gene encoding NF-κB-inducing kinase, which is known to modulate IKKα function, had no inhibitory effect on either response in reovirus-infected cells. Collectively, these findings indicate a novel pathway of NF-κB/Rel activation involving IKKα and IKKγ/Nemo, which together mediate the expression of downstream proapoptotic genes in reovirus-infected cells.
Charm Decays at B Factories
Authors:   Representing the BABAR collaboration., Meadows Brian T.
Published: November 2006

Recent results relating to charm baryon and meson decays from the Belle and BABAR experiments are presented. In addition to recent observations for charm hyperons, evidence for a new charm baryon state, the Λc(2940), observed in its decay to D0p is also reported. No evidence for doubly charmed baryons is seen in e+e- interactions. A measurement of the spin of the Ω- hyperon is made using decays of the [Formula: see text] and [Formula: see text] baryons. On the assumption that the spin of the parent baryons are J = 1/2, the assignment J = 3/2 is confirmed and both J = 1/2 and also higher spins are excluded. New results on rare, Cabibbo-suppressed decays of charm mesons are also presented.
Leptonic D+ and $D_s^+$ Decays at CLEO-c
Authors:   Representing the CLEO Collaboration., Ryd Anders
Published: November 2006

We report measurements of the branching fractions for the leptonic decays D+ → μ+νμ and [Formula: see text] from the CLEO-c experiment. From these measurements we extract the decay constants [Formula: see text] and fDs = 280.1 ± 11.6 ± 6.0 MeV .
D Mixing and CPV in D Decays from Belle
Authors: Zhang L. M.
Published: November 2006

We report the recent results of [Formula: see text] mixing and CP violation studies in D0 decays from Belle, which include the time-dependent measurements of D0 wrong-sign semileptonic decay, wrong-sign hadronic decay to K+π-, as well as the wrong-sign ratio of hadronic decays to K+π-n(π).
Cleavage of the angiotensin II type 1 receptor and nuclear accumulation of the cytoplasmic carboxy-terminal fragment
Authors: Cook Julia L. , Mills Sarah J. , Naquin Ryan T. , Alam Jawed , Re Richard N.
Published: November 2006

Our published studies show that the distribution of the ANG II type 1 (AT1) receptor (AT1R), expressed as a enhanced yellow fluorescent fusion (YFP) protein (AT1R/EYFP), is altered upon cellular treatment with ANG II or coexpression with intracellular ANG II. AT1R accumulates in nuclei of cells only in the presence of ANG II. Several transmembrane receptors are known to accumulate in nuclei, some as holoreceptors and others as cleaved receptor products. The present study was designed to determine whether the AT1R is cleaved before nuclear transport. A plasmid encoding a rat AT1R labeled at the amino terminus with enhanced cyan fluorescent protein (CFP) and at the carboxy terminus with EYFP was employed. Image analyses of this protein in COS-7 cells, CCF-STTG1 glial cells, and A10 vascular smooth muscle cells show the two fluorescent moieties to be largely spatially colocalized in untreated cells. ANG II treatment, however, leads to a separation of the fluorescent moieties with yellow fluorescence accumulating in more than 30% of cellular nuclei. Immunoblot analyses of extracts and conditioned media from transfected cells indicate that the CFP domain fused to the extracellular amino-terminal AT1R domain is cleaved from the membrane and that the YFP domain, together with the intracellular cytoplasmic carboxy terminus of the AT1R, is also cleaved from the membrane-bound receptor. The carboxy terminus of the AT1R is essential for cleavage; cleavage does not occur in protein deleted with respect to this region. Overexpressed native AT1R (nonfusion) is also cleaved; the intracellular 6-kDa cytoplasmic domain product accumulates to a significantly higher level with ANG II treatment.
Cellular and molecular determinants of altered Ca2+handling in the failing rabbit heart: primary defects in SR Ca2+uptake and release mechanisms
Authors: Armoundas Antonis A. , Rose Jochen , Aggarwal Rajesh , Stuyvers Bruno D. , O'Rourke Brian , Kass David A. , Marbán Eduardo , Shorofsky Stephen R. , Tomaselli Gordon F. , William Balke C.
Published: November 2006

Myocytes from the failing myocardium exhibit depressed and prolonged intracellular Ca2+concentration ([Ca2+]i) transients that are, in part, responsible for contractile dysfunction and unstable repolarization. To better understand the molecular basis of the aberrant Ca2+handling in heart failure (HF), we studied the rabbit pacing tachycardia HF model. Induction of HF was associated with action potential (AP) duration prolongation that was especially pronounced at low stimulation frequencies. L-type calcium channel current ( ICa,L) density (−0.964 ± 0.172 vs. −0.745 ± 0.128 pA/pF at +10 mV) and Na+/Ca2+exchanger (NCX) currents (2.1 ± 0.8 vs. 2.3 ± 0.8 pA/pF at +30 mV) were not different in myocytes from control and failing hearts. The amplitude of peak [Ca2+]iwas depressed (at +10 mV, 0.72 ± 0.07 and 0.56 ± 0.04 μM in normal and failing hearts, respectively; P < 0.05), with slowed rates of decay and reduced Ca2+spark amplitudes ( P < 0.0001) in myocytes isolated from failing vs. control hearts. Inhibition of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a revealed a greater reliance on NCX to remove cytosolic Ca2+in myocytes isolated from failing vs. control hearts ( P < 0.05). mRNA levels of the α1C-subunit, ryanodine receptor (RyR), and NCX were unchanged from controls, while SERCA2a and phospholamban (PLB) were significantly downregulated in failing vs. control hearts ( P < 0.05). α1Cprotein levels were unchanged, RyR, SERCA2a, and PLB were significantly downregulated ( P < 0.05), while NCX protein was significantly upregulated ( P < 0.05). These results support a prominent role for the sarcoplasmic reticulum (SR) in the pathogenesis of HF, in which abnormal SR Ca2+uptake and release synergistically contribute to the depressed [Ca2+]iand the altered AP profile phenotype.
Effect of arterial oxygenation on quadriceps fatigability during isolated muscle exercise
Authors: Katayama Keisho , Amann Markus , Pegelow David F. , Jacques Anthony J. , Dempsey Jerome A.
Published: November 2006

The effect of various levels of oxygenation on quadriceps muscle fatigability during isolated muscle exercise was assessed in six male subjects. Twitch force (Qtw) was assessed using supramaximal magnetic femoral nerve stimulation. In experiment 1, maximal voluntary contraction (MVC) and Qtw of resting quadriceps muscle were measured in normoxia [inspired O2 fraction (FiO2) = 0.21, percent arterial O2 saturation (Sp[Formula: see text]) = 98.4%, estimated arterial O2 content (CaO2) = 20.8 ml/dl], acute hypoxia (FiO2 = 0.11, Sp[Formula: see text] = 74.6%, CaO2 = 15.7 ml/dl), and acute hyperoxia (FiO2 = 1.0, Sp[Formula: see text] = 100%, CaO2 = 22.6 ml/dl). No significant differences were found for MVC and Qtw among the three FiO2 levels. In experiment 2, the subjects performed three sets of nine, intermittent, isometric, unilateral, submaximal quadriceps contractions (62% MVC followed by 1 MVC in each set) while breathing each FiO2. Qtw was assessed before and after exercise, and myoelectrical activity of the vastus lateralis was obtained during exercise. The percent reduction of twitch force (potentiated Qtw) in hypoxia (−27.0%) was significantly ( P < 0.05) greater than in normoxia (−21.4%) and hyperoxia (−19.9%), as were the changes in intratwitch measures of contractile properties. The increase in integrated electromyogram over the course of the nine contractions in hypoxia (15.4%) was higher ( P < 0.05) than in normoxia (7.2%) or hyperoxia (6.7%). These results demonstrate that quadriceps muscle fatigability during isolated muscle exercise is exacerbated in acute hypoxia, and these effects are independent of the relative exercise intensity.
ATP reduces gel compaction in osteoblast-populated collagen gels
Authors: Qi Jie , Chi Liqun , Faber James , Koller Beverly , Banes Albert J.
Published: November 2006

Bone remodeling is a localized process, but regulated by systemic signals such as hormones, cytokines, and mechanical loading. The mechanism by which bone cells convert these systemic signals into local signals is not completely understood. It is broadly accepted that the “prestress” in cytoskeleton of cells affects the magnitude of cellular responses to mechanical stimuli. Prestress derives from stiff cytoskeletal proteins and their connections within the cell and from cell contractility upon attaching to matrix. In an in vitro model of three-dimensional gel compaction, the relative cellular prestress levels in the same matrix environment were determined by matrix compaction rate: a greater compaction rate resulted in a higher level of prestress. In the present study, the effects of ATP on the prestress of osteoblasts were studied using mouse MC3T3-E1 cells grown in three-dimensional bioartificial tissues (BATs). ATP (≥100 μM) reduced the compaction rate of BATs in a dose-dependent manner. ADP, 2′-(or 3′)- O-(4-benzoylbenzoyl) ATP, and UTP, but not α,β-methylene ATP, also reduced the compaction rate but to a lesser extent. Pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid tetrasodium did not block the effect of ATP on BAT compaction rate. These results indicate that both P2X and P2Y receptors are involved in ATP-induced reduction of BAT compaction rate. Steady fluid flow and RT-PCR results showed that ATP reduced cell attachment on type I collagen by downregulating the expression of integrin α1. These results suggest a potential role for P2 receptors in matrix remodeling and repair and as a potential drug target in treatment of bone diseases.
A novel, fully implantable, multichannel biotelemetry system for measurement of blood flow, pressure, ECG, and temperature
Authors: Axelsson M. , Dang Q. , Pitsillides K. , Munns S. , Hicks J. , Kassab G. S.
Published: November 2006

Biotelemetry provides high-quality data in awake, free-ranging animals without the effects of anesthesia and surgery. Although many biological parameters can be measured using biotelemetry, simultaneous telemetric measurements of pressure and flow have not been available. The objective of this study was to evaluate simultaneous measurements of blood flow, pressure, ECG, and temperature in a fully implantable system. This novel system allows the measurement of up to four channels of blood flow, up to three channels of pressure, and a single channel each of ECG and temperature. The system includes a bidirectional radio-frequency link that allows the implant to send data and accept commands to perform various tasks. The system is controlled by a base station decoder/controller that decodes the data stream sent by the implant into analog signals. The system also converts the data into a digital data stream that can be sent via ethernet to a remote computer for storage and/or analysis. The system was chronically implanted in swine and alligators for up to 5 wk. Both bench and in vivo animal tests were performed to evaluate system performance. Results show that this biotelemetry system is capable of long-term accurate monitoring of simultaneous blood flow and pressure. The system allows, within the room, recordings, since the implant transmission range is between 6 and 10 m, and, with a relay, backpack transmission distance of up to 500 m can be achieved. This system will have significant utility in chronic models of cardiovascular physiology and pathology.
Dependence of changes in β-adrenoceptor signal transduction on type and stage of cardiac hypertrophy
Authors: Sethi Rajat , Saini Harjot K. , Guo Xiaobing , Wang Xi , Elimban Vijayan , Dhalla Naranjan S.
Published: November 2006

To examine whether cardiac hypertrophy is associated with changes in β-adrenoceptor signal transduction mechanisms, pressure overload (PO) was induced by occlusion of the abdominal aorta and volume overload (VO) by creation of an aortocaval shunt for 4 and 24 wk in rats. After hemodynamic assessment of the animals, the left ventricular (LV) particulate fraction was isolated for measurement of β1-adrenoceptors and adenylyl cyclase activity, and cardiomyocytes were isolated for monitoring of the intracellular Ca2+concentration. Although PO and VO produced cardiac hypertrophy and increased LV end-diastolic pressure at 4 wk, cardiac function was increased in animals subjected to PO but remained unaltered in animals subjected to VO. Cardiac hypertrophy and increased LV end-diastolic pressure were associated with depressed cardiac function at 24 wk of PO or VO, but clinical signs of congestive heart failure were evident only in animals subjected to VO. Isoproterenol-induced increases in cardiac function, activation of adenylyl cyclase activity, and increase in intracellular Ca2+concentration, as well as β1-adrenoceptor density, were unaltered by PO at 4 wk, augmented by VO at 4 wk, and attenuated by PO and VO at 24 wk. These results suggest that alterations in β1-adrenoceptor signal transduction are dependent on the type and stage of cardiac hypertrophy.
Transfer function analysis between arterial pressure and renal sympathetic nerve activity at cardiac pacing frequencies in the rat
Authors: Oréa Valérie , Kanbar Roy , Chapuis Bruno , Barrès Christian , Julien Claude
Published: November 2006

This study examined the possible influence of changes in heart rate (HR) on the gain of the transfer function relating renal sympathetic nerve activity (RSNA) to arterial pressure (AP) at HR frequency in rats. In seven urethane-anesthetized rats, AP and RSNA were recorded under baseline conditions (spontaneous HR = 338 ± 6 beats/min, i.e., 5.6 ± 0.1 Hz) and during 70-s periods of cardiac pacing at 6–9 Hz applied in random order. Cardiac pacing slightly increased mean AP (0.8 ± 0.2 mmHg/Hz) and decreased pulse pressure (−3.6 ± 0.3 mmHg/Hz) while leaving the mean level of RSNA essentially unaltered ( P = 0.680, repeated-measures ANOVA). The gain of the transfer function from AP to RSNA measured at HR frequency was always associated with a strong, significant coherence and was stable between 6 and 9 Hz ( P = 0.185). The transfer function gain measured under baseline conditions [2.44 ± 0.28 normalized units (NU)/mmHg] did not differ from that measured during cardiac pacing (2.46 ± 0.27 NU/mmHg). On the contrary, phase decreased linearly as a function of HR, which indicated the presence of a fixed time delay (97 ± 6 ms) between AP and RSNA. In conclusion, the dynamic properties of arterial baroreflex pathways do not affect the gain of the transfer function between AP and RSNA measured at HR frequency in the upper part of the physiological range of HR variations in the rat.
Direct Comparison of the Task-Dependent Discharge of M1 in Hand Space and Muscle Space
Authors: Morrow M. M. , Jordan L. R. , Miller L. E.
Published: November 2006

Since its introduction in the early 1980s, the concept of a “preferred direction” for neuronal discharge has proven to be a powerful means of studying motor areas of the brain. In the current paper, we introduce the concept of a “muscle-space”–preferred direction (PDM) that is analogous to the familiar hand-space–preferred direction (PDH). PDM reflects the similarity between the discharge of a given neuron and the activity of each muscle in much the way that PDH reflects the similarity of discharge with motion along each of the three Cartesian coordinate axes. We used PDM to analyze the data recorded from neurons in the primary motor cortex (M1) of three different monkeys. The monkeys performed center-out movements within two different cubical workspaces centered either to the left or right of the monkey's shoulder while we simultaneously recorded neuronal discharge, muscle activity, and limb orientation. We calculated preferred directions in both hand space and muscle space, and computed the angles between these vectors under a variety of conditions. PDs for different neurons were broadly distributed throughout both hand space and muscle space, but the muscle-space vectors appeared to form clusters of functionally similar neurons. In general, repeated estimates of PDM were more stable over time than were similar estimates of PDH. Likewise, there was less change in PDM than in PDH for data recorded from the two different workspaces. However, although a majority of neurons had this muscle-like property, a significant minority was more stable in Cartesian hand space, reflecting a heterogeneity of function within M1.
Identification and Clinical Impact of Impaired Cerebrovascular Autoregulation in Patients With Malignant Middle Cerebral Artery Infarction
Authors: Dohmen Christian , Bosche Bert , Graf Rudolf , Reithmeier Thomas , Ernestus Ralf-Ingo , Brinker Gerrit , Sobesky Jan , Heiss Wolf-Dieter
Published: November 2006

Background and Purpose—

To study cerebrovascular autoregulation and its impact on clinical course in patients with impending malignant middle cerebral artery infarction, we used invasive multimodal neuromonitoring, including measurement of cerebral perfusion pressure, tissue oxygen pressure, and microdialysis.

Methods—

Fifteen patients with a stroke that involved >50% of the middle cerebral artery territory were included. Probes were placed into the ipsilateral frontal lobe. Autoregulation was assessed by calculation of the cerebral perfusion pressure–oxygen reactivity index (COR) and the correlation coefficient (
R
) of cerebral perfusion pressure and tissue oxygen pressure at 24 and 72 hours after stroke.

Results—

COR and
R
at 24 hours after stroke were higher in the 8 patients with a malignant course (ie, massive edema formation) compared with the 7 patients with a benign course (COR, 1.99±1.46 versus 0.68±0.29;
R
, 0.49±0.28 versus 0.06±0.31;
P
<0.05), indicating impaired autoregulation in the malignant course group. At 72 hours, further increases in COR and
R
were observed in the malignant course group in contrast to the benign course group with stable values over time (COR, 3.31±2.38 versus 0.75±0.31;
R
, 0.75±011 versus 0.36±0.27;
P
<0.05). With a COR of 0.99, a cutoff value for prediction of a malignant course was found. The lactate-pyruvate ratio was higher in patients with a malignant compared with a benign course at both time points. COR,
R
, and the lactate-pyruvate ratio showed significant correlations with outcome parameters as a midline shift on cranial computed tomography and score on the modified Rankin scale after 3 months.

Conclusions—

We found early impairment of cerebrovascular autoregulation in peri-infarct tissue of patients who developed malignant brain edema, whereas autoregulation was preserved in patients with a benign course. Impaired cerebral autoregulation seems to play a key role for development of a malignant course and might serve as a predictive marker. Impaired cerebral autoregulation also accentuates the need for consequent adjustment of cerebral perfusion pressure in patients with impaired autoregulation.