bluuebunny/crossref_metadata_2025 huggingface dataset:
Slc11a1, Formerly Nramp1, Is Expressed in Dendritic Cells and Influences Major Histocompatibility Complex Class II Expression and Antigen-Presenting Cell Function
Authors: Stober Carmel B. , Brode Sven , White Jacqueline K. , Popoff Jean-François , Blackwell Jenefer M.
Published: July 2007

Solute carrier family 11 member a1 (Slc11a1; formerlyNramp1) encodes a late endosomal/lysosomal protein/divalent cation transporter that regulates iron homeostasis in macrophages. During macrophage activation, Slc11a1 has multiple pleiotropic effects on gene regulation and function, including gamma interferon-induced class II expression and antigen-presenting cell function. The wild-type allele atSlc11a1has been associated with a bias in Th1 cell function in vivo, which is beneficial in resistance to infection against intracellular macrophage pathogens but detrimental in contributing to development of type 1 diabetes. The extent to which this depends on macrophage versus dendritic cell (DC) function is not known. Here we show that Slc11a1 is expressed in late endosomes and/or lysosomes of CD11c+DCs. DCs from mutant and congenic wild-type mice upregulate interleukin-12 (IL-12) and IL-10 mRNA in response to lipopolysaccharide (LPS) stimulation, but the ratio of IL-10 to IL-12 is higher in unstimulated DCs and DCs stimulated for 15 h with LPS from mutant mice than from wild-type mice. DCs from wild-type mice upregulate major histocompatibility complex class II in response to LPS more efficiently than DCs from mutant mice. Unstimulated DCs from wild-type and mutant mice present ovalbumin (OVA) peptide with an efficiency equivalent to that of an OVA-specific CD4 T-cell line, but DCs from wild-type mice are more efficient at processing and presenting OVA orLeishmaniaactivator of cell kinase (LACK) protein to OVA- and LACK-specific T cells. These data indicate that wild-type Slc11a1 expressed in DCs may play a role both in determining resistance to infectious disease and in susceptibility to autoimmune disease such as type 1 diabetes.
Contribution of a Novel Gene,
rpeA
, Encoding a Putative Autotransporter Adhesin to Intestinal Colonization by Rabbit-Specific Enteropathogenic
Escherichia coli
Authors: Leyton Denisse L. , Adams Louise M. , Kelly Michelle , Sloan Joan , Tauschek Marija , Robins-Browne Roy M. , Hartland Elizabeth L.
Published: July 2007

Rabbit-specific enteropathogenic
Escherichia coli
(REPEC) is an attaching and effacing pathogen of young rabbits. Using signature-tagged mutagenesis, we identified several known colonization factors of REPEC as well as a gene predicted to encode a novel autotransporter protein. This novel gene was termed
rpeA
for
R
EPEC
p
lasmid-
e
ncoded
a
utotransporter.
Influence of the Cpx Extracytoplasmic-Stress-Responsive Pathway on
Yersinia
sp.-Eukaryotic Cell Contact
Authors: Carlsson Katrin E. , Liu Junfa , Edqvist Petra J. , Francis Matthew S.
Published: July 2007

The extracytoplasmic-stress-responsive CpxRA two-component signal transduction pathway allows bacteria to adapt to growth in extreme environments. It controls the production of periplasmic protein folding and degradation factors, which aids in the biogenesis of multicomponent virulence determinants that span the bacterial envelope. This is true of the
Yersinia pseudotuberculosis
Ysc-Yop type III secretion system. However, despite using a second-site suppressor mutation to restore Yop effector secretion by yersiniae defective in the CpxA sensor kinase, these bacteria poorly translocated Yops into target eukaryotic cells. Investigation of this phenotype herein revealed that the expression of genes which encode several surface-located adhesins is also influenced by the Cpx pathway. In particular, the expression and surface localization of invasin, an adhesin that engages β1-integrins on the eukaryotic cell surface, are severely restricted by the removal of CpxA. This reduces bacterial association with eukaryotic cells, which could be suppressed by the ectopic production of CpxA, invasin, or RovA, a positive activator of
inv
expression. In turn, these infected eukaryotic cells then became susceptible to intoxication by translocated Yop effectors. In contrast, bacteria harboring an in-frame deletion of
cpxR
, which encodes the cognate response regulator, displayed an enhanced ability to interact with cell monolayers, as well as elevated
inv
and
rovA
transcription. This phenotype could be drastically suppressed by providing a wild-type copy of
cpxR
in
trans
. We propose a mechanism of
inv
regulation influenced by the direct negative effects of phosphorylated CpxR on
inv
and
rovA
transcription. In this fashion, sensing of extracytoplasmic stress by CpxAR contributes to productive
Yersinia
sp.-eukaryotic cell interactions.
A Review on Recent Developments in Syntheses of the post-Secodine Indole Alkaloids. Part II: Modified Alkaloid Types
Authors: Hájíček Josef
Published: July 2007

The second part of the planned review on developments in the field of total and formal total synthesis of the post-secodine indole alkaloids concentrates on modified alkaloid types, i.e. those skeletons derived from primary types by formation of additional and/or rupture of existing bonds, while connectivities next to indol(e)ine moiety remain intact. It thus reviews the synthesis of alkaloids of quebrachamine/cleavamine type including VLB-bis-indoles, rhazinilam type, aspidofractinine/kopsane and kopsifoline type, as well as kopsijasminilam alkaloids, lapidilectine B and danuphylline. It covers the literature of from 1991-1992 up to approximately end 2006. A review with 174 references.
Self-rescue swimming in cold water: the latest advice
Authors: Ducharme Michel B. , Lounsbury David S.
Published: July 2007

According to the 2006 Canadian Red Cross Drowning Report, 2007 persons died of cold-water immersion in Canada between 1991 and 2000. These statistics indicate that prevention of cold-water immersion fatalities is a significant public health issue for Canadians. What should a person do after accidental immersion in cold water? For a long time, aquatic safety organizations and government agencies stated that swimming should not be attempted, even when a personal flotation device (PFD) is worn. The objective of the present paper is to present the recent scientific evidence making swimming a viable option for self-rescue during accidental cold-water immersion. Early studies in the 1960s and 1970s led to a general conclusion that “people are better off if they float still in lifejackets or hang on to wreckage and do not swim about to try to keep warm”. Recent evidence from the literature shows that the initial factors identified as being responsible for swimming failure can be either easily overcome or are not likely the primary contributors to swimming failure. Studies over the last decade reported that swimming failure might primarily be related not to general hypothermia, but rather to muscle fatigue of the arms as a consequence of arm cooling. This is based on the general observation that swimming failure developed earlier than did systemic hypothermia, and can be related to low temperature of the arm muscles following swimming in cold water. All of the above studies conducted in water between 10 and 14 °C indicate that people can swim in cold water for a distance ranging between about 800 and 1500 m before being incapacitated by the cold. The average swimming duration for the studies was about 47 min before incapacitation, regardless of the swimming ability of the subjects. Recent evidence shows that people have a very accurate idea about how long it will take them to achieve a given swimming goal despite a 3-fold overestimation of the absolute distance to swim. The subjects were quite astute at deciding their swimming strategy early in the immersion with 86% success, but after about 30 min of swimming or passive cooling, their decision-making ability became impaired. It would therefore seem wise to make one’s accidental immersion survival plan early during the immersion, directly after cessation of the cold shock responses. Additional recommendations for self-rescue are provided based on recent scientific evidence.
Voluntary wheel running ameliorates vascular smooth muscle hyper-contractility in type 2 diabetic db/db mice
Authors: Esser Karyn A. , Su Wen , Matveev Sergey , Wong Vicki , Zeng Li , McCarthy John J. , Smart Eric J. , Guo Zhenheng , Gong Ming C.
Published: July 2007

Physical activity reduces cardiovascular disease related mortality in diabetic patients. However, it is unknown if the diabetic state reduces voluntary physical activity and, if so, if the voluntary physical activity at the reduced level is sufficient to improve cardiovascular risk factors. To address these two specific questions, we investigated voluntary wheel running performance in an obese and type 2 diabetic mouse model, the db/db mice. In addition, we determined the effects of running on body mass, blood glucose, insulin, plasma free fatty acids, cholesterol, and vascular smooth muscle hyper-contractility. Our results showed that daily running distance, time, and speed were significantly reduced in the db/db mice to about 23%, 32%, and 71%, respectively, of that in non-diabetic control mice. However, this low level of running was sufficient to induce a reduction in the vascular smooth muscle hyper-contractility, cholesterol, and some plasma free fatty acids, as well as to delay the decrease in blood insulin. These changes occurred in the absence of weight loss and a detectable decrease in blood glucose. Thus, the results of this study demonstrated that voluntary wheel running activity was dramatically reduced in db/db mice. However, the low levels of running were beneficial, in the absence of effects on obesity or blood glucose, with significant reductions in cardiovascular risk factors and potential delays in β-cell dysfunction.
FINDING γ FROM THE η-η′ MIXING WITHIN QCD FACTORIZATION
Authors: DAS PRASANTA KUMAR
Published: July 2007

We propose a method to determine the weak CP violating angle γ by analyzing the charmless nonleptonic B→(η, η′)K decay within the QCD factorization framework. We obtain constraints in the γ–θ (the octet-singlet mixing angle in η-η′ sector) contour plane by using the world average data of direct CP-asymmetry Acp(B→(η, η′)K) and the branching ratio BR (B+→(η, η′)K+). For Acp(B→η(η′)K) = -0.33±0.12(0.031±0.021), we find that γ lies in between 60°(20°) and 160°(160°) for θ = -21.3° for μ = mb/2, whereas for μ = mband the same θ, it lies in between 75°(20°) and 150°(160°). We discuss the two mixing angles scenario arised in the SU (3)Fsymmetry breaking limit. We also include the effect of the power corrections in our analysis and found those not so significant in the present case.
NONCOMMUTATIVITY IN A SIMPLE TOY MODEL
Authors: MALIK R. P.
Published: July 2007

We discuss various symmetry properties of the reparametrization invariant toy model of a free nonrelativistic particle and show that its commutativity and noncommutativity (NC) properties are the artifact of the underlying symmetry transformations. For the case of the symmetry transformations corresponding to the noncommutative geometry, the mass parameter of the toy model turns out to be noncommutative in nature. By exploiting the BRST symmetry transformations, we demonstrate the existence of this NC and show its cohomological equivalence with its commutative counterpart. A connection between the usual gauge symmetry transformations corresponding to the commutative geometry and the quantum groups, defined on the phase space, is also established for the present model at the level of Poisson bracket structure. We show that, for the noncommutative geometry, such a kind of quantum group connection does not exist.
NEUTRINO MIXING: FROM THE BROKEN μ-τ SYMMETRY TO THE BROKEN FRIEDBERG–LEE SYMMETRY
Authors: XING ZHI-ZHONG
Published: July 2007

I argue that the observed flavor structures of leptons and quarks might imply the existence of certain flavor symmetries. The latter should be a good starting point to build realistic models towards deeper understanding of the fermion mass spectra and flavor mixing patterns. The μ-τ permutation symmetry serves for such an example to interpret the almost maximal atmospheric neutrino mixing angle (θ23 ~ 45°) and the strongly suppressed CHOOZ neutrino mixing angle (θ13 < 10°). In this talk I like to highlight a new kind of flavor symmetry, the Friedberg–Lee symmetry, for the effective Majorana neutrino mass operator. Luo and I have shown that this symmetry can be broken in an oblique way, such that the lightest neutrino remains massless but an experimentally-favored neutrino mixing pattern is achievable. We get a novel prediction for θ13 in the CP-conserving case: sin θ13 = tan θ12|(1 - tan θ23)/(1 + tan θ23)|. Our scenario can simply be generalized to accommodate CP violation and be combined with the seesaw mechanism. Finally I stress the importance of probing possible effects of μ-τ symmetry breaking either in terrestrial neutrino oscillation experiments or with ultrahigh-energy cosmic neutrino telescopes.
LOW ENERGY EFFECTIVE LAGRANGIAN FOR SUPERSYMMETRIC SEESAW MODEL
Authors: KATO AKINA , MOROZUMI TAKUYA , YOKOZAKI NORIMI , KANG SYN KYU
Published: July 2007

Seesaw model is an attractive model because it may explain baryogenesis through leptogenesis and also may explain the small neutrino mass. The supersymmetric seesaw model may be more attractive because the naturalness problem is absent in supersymmetric theory. Recently, the higgs mass correction due to leptons and sleptons loops is computed.1 In this talk, we report on the preliminary results on the one loop corrections of leptons and sleptons loops to the effective action of Higgs sector for super symmetric seesaw model. Our results show that the corrections to the mass parameters for Higgs sector are proportional to the soft breaking parameters of supersymmetric seesaw model, while for the quartic couplings of Higgs fields, the corrections are suppressed by inverse powers of the right-handed neutrino mass.
ANOMALY OF DISCRETE FAMILY SYMMETRIES AND GAUGE COUPLING UNIFICATION
Authors: ARAKI TAKESHI
Published: July 2007

Anomaly of a discrete symmetry is defined as the Jacobian of the path-integral measure. Assuming that anomaly at low energy is cancelled by the Green–Schwarz (GS) mechanism at a fundamental scale, we investigate possible Kac–Moody levels for anomalous discrete family symmetries. As the first example we consider discrete abelian Baryon number and Lepton number symmetries in the minimal supersymmetric standard model with see-saw mechanism, and find that the ordinary unification of gauge couplings is not consistent with the GS conditions, indicating a possible existence of further Higgs doublets. Next we consider the recently proposed supersymmetric model with Q6 family symmetry. In this model, the GS conditions are such that the gauge coupling unification appears close to the Planck scale.
INTRODUCING NEUTRINO MASS INTO UNIVERSAL EXTRA DIMENSION MODELS AND SOLVING COSMOLOGICAL PROBLEM
Authors: MATSUMOTO SHIGEKI , SATO JOE , YAMANAKA MASATO , SENAMI MASATO
Published: July 2007

Universal extra dimension (UED) models with right-handed neutrinos are studied. The introduction of the neutrinos makes us possible not only to describe Dirac neutrino masses but also to solve the cosmological problem called the KK graviton problem. This problem is essentially caused by the late time decay of a KK photon into a KK graviton and a photon, and it distorts the spectrum of the cosmic microwave background or the diffuse photon. We point out that, once we introduce right-handed neutrinos to UED models, the KK photon decays dominantly into neutrinos and does not emit a photon. We also discuss sub-dominant modes with a photon in the decay quantitatively, and show that their branching ratios are so small that the spectra are not distorted.
Core-Level Spectroscopy in High-Tc Superconductors
Authors: Kotani Akio , Okada Kozo
Published: July 2007

A short review is presented on the spectroscopic study of X-ray photoemission (XPS), X-ray absorption (XAS) and X-ray emission (XES) associated with the Cu 2p and O 1s core-levels in high- Tc systems and related materials. Experimental data are analyzed using the single-site impurity Anderson model (and its extension) with Cu 3d orbitals and O 2p valence bands specified by irreducible representations of the D4h symmetry around the Cu atom. By analyzing Cu 2p-XPS, we can get information on the hybridization strength between Cu 3d and O 2p states and the charge transfer energy. In determining the spectral shape of the XPS satellite, it is shown that the interplay between the intraatomic multiplet coupling and the solid-state hybridization plays an essential role. The Cu 2p-XAS, especially its polarization dependence, gives the most direct information on the site and the symmetry of doped holes. Finally, we show the Cu 2p-XES can also be interpreted with the impurity Anderson model in a manner consistent with XPS and XAS.
Dynamics of Antiferromagnetic Heisenberg Model at Low Temperatures
Authors: Takahashi Minoru
Published: July 2007

Dynamical correlation function Gr(t)=〈Sr(t)·S0(0)〉 and dynamical structure factor Sq(ω) for the Heisenberg antiferromagnet are calculated by the modified spin-wave theory. We use the Dyson-Maleev transformation, the ideal spin-wave states and the rotational averaging. The static correlation function Gr(t=0) coincides with that obtained in previous papers for the antiferromagnet. We rederive the Auerbach and Arovas dynamical structure factor. This satisfies the dynamic scaling hypothesis at low temperature and low momentum. Analytical form of dynamical scaling function is obtained. We find that the characteristic time τ is proportional to the correlation length ξ. In the classical limit our results are compared with the molecular dynamics calculation for 1D system. The agreement is good for the short time correlation, but it is not good for the long time correlation. This is in contrast to the agreement for a wide range of time in the case of ferromagnet. The analysis of magnetic susceptibility of La2CuO4 is given.
Structure Analysis of the CaF2/Si(111) Interface in Its Initial Stage of Formation by Coaxial Impact-Collision Ion Scattering Spectroscopy (CAICISS)
Authors: Katayama Mitsuhiro , King B. V. , Nomura Eiichi , Aono Masakazu
Published: July 2007

The structure of the CaF2/Si(111) interface in its initial stage of formation has been analyzed with a coaxial impact-collision ion scattering spectroscopy (CAICISS), in which an ion source and a time-of-flight energy analyzer are arranged coaxially so as to take the experimental scattering angle at 180°. It has been found that in the initial stage of the formation of the CaF2/Si(111) interface, a monolayer of CaF rather than CaF2 is formed on Si(111). The arrangement of the Ca and F atoms in the monolayer of CaF with reference to Si(111) is B-type, the Ca atoms being situated at the T4. site just above the second-layer Si atoms. The interlayer distance between the topmost F layer and the underlaying Ca layer is estimated to be 0.64 ± 0.05 A.
Overview
Authors: Tamagaki Ryozo
Published: July 2007

An overview is given to various phases of nuclear matter in high density region from the nuclear density ρ0 to about 10 ρ0. Emphasis is put on how the characteristic aspects of the phases and their realization mechanisms reflect specific features of the nuclear interaction. This chapter also serves for an introductory description to the succeeding chapters.
Level Statistics and Time Evolution at the Mobility Edge
Authors: Evangelou S. N.
Published: July 2007

We present results for the statistics of the eigenvalues in random matrix ensembles characterized by an Anderson delocalization-localization transition. The nearest-level-spacing distribution function P(S) and the number variance 〈(δN(E))2〉 are shown at the mobility edge where we obtain universal curves interpolating between Wigner-Dyson and Poisson statistics valid for delocalized and for localized eigenfunctions, respectively. We also discuss the connection of level statistics with dynamics by considering the time evolution of a quantum wavepacket in a quasirandom matrix model. The critical quantum dynamics is characterized by anomalous diffusion, described via continuous sets of multifractal exponents.
Envelope Equations Near the Onset of a Hexagonal Pattern
Authors: Brand Helmut R.
Published: July 2007

We present the amplitude equation including slow spatial modulations for the hexagonal patterns observed near the onset of the Bénard instability in the presence of non-Boussinesq effects. In contrast to the onset of convection in Boussinesq approximation for rigid-rigid boundary conditions, we do not find a generalized thermodynamic potential. The same conclusion is found to hold for surface tension driven Marangoni convection and for temporally modulated convection. We also point out the applicability of our approach to other systems such as the Rosenzweig instability in ferrofluids as well as to the baroclinic instability and to the buckling of plates and shells, for which an envelope equation, which is second order in time, results.
Preoperative Thresholds for Pulmonary Valve Replacement in Patients With Corrected Tetralogy of Fallot Using Cardiovascular Magnetic Resonance
Authors: Oosterhof Thomas , van Straten Alexander , Vliegen Hubert W. , Meijboom Folkert J. , van Dijk Arie P.J. , Spijkerboer Anje M. , Bouma Berto J. , Zwinderman Aeilko H. , Hazekamp Mark G. , de Roos Albert , Mulder Barbara J.M.
Published: July 2007

Background—

To facilitate the optimal timing of pulmonary valve replacement, we analyzed preoperative thresholds of right ventricular (RV) volumes above which no decrease or normalization of RV size takes place after surgery.

Methods and Results—

Between 1993 and 2006, 71 adult patients with corrected tetralogy of Fallot underwent pulmonary valve replacement in a nationwide, prospective follow-up study. Patients were evaluated with cardiovascular magnetic resonance both preoperatively and postoperatively. Changes in RV volumes were expressed as relative change from baseline. RV volumes decreased with a mean of 28%. RV ejection fraction did not change significantly after surgery (from 42±10% to 43±10%;
P
=0.34). Concomitant RV outflow tract reduction resulted in a 25% larger decrease of RV volumes. After correction for surgical RV outflow tract reduction, higher preoperative RV volumes (mL/m
2
) were independently associated with a larger decrease of RV volumes (RV end-diastolic volume: β=0.41;
P
<0.001). Receiver operating characteristic analysis revealed a cutoff value of 160 mL/m
2
for normalization of RV end-diastolic volume or 82 mL/m
2
for RV end-systolic volume.

Conclusions—

Overall, we could not find a threshold above which RV volumes did not decrease after surgery. Preoperative RV volumes were independently associated with RV remodeling and also when corrected for a surgical reduction of the RV outflow tract. However, normalization could be achieved when preoperative RV end-diastolic volume was <160 mL/m
2
or RV end-systolic volume was <82 mL/m
2
.
Neurogenic Abnormalities in Masked Hypertension
Authors: Grassi Guido , Seravalle Gino , Trevano Fosca Quarti , Dell’Oro Raffaella , Bolla GianBattista , Cuspidi Cesare , Arenare Francesca , Mancia Giuseppe
Published: July 2007

Patients with hypertension exhibit an increased sympathetic activity. No information exists as to whether this is the case in normotensive individuals in whom there is an increased ambulatory blood pressure, a condition termed “masked” hypertension. We studied 18 middle-aged subjects with masked hypertension in whom we measured muscle sympathetic nerve traffic (peroneal nerve and microneurography) and beat-to-beat arterial blood pressure at rest and during baroreceptor deactivation and activation. Measurements also included anthropometric values and insulin sensitivity (homeostasis model assessment index). Data were compared with those of 20 normotensive subjects, 18 subjects with white-coat hypertension, and 20 patients with “in-office” and “out-of-office” hypertension. All of the individuals were pharmacologically untreated and age-matched with subjects with masked hypertension. Patients with in- and out-of-office and white-coat hypertension displayed resting sympathetic nerve activity values significantly greater than normotensive subjects (75.8±2.5 and 70.8±2.2 versus 45.5±2.0 bursts per 100 heartbeats respectively;
P
<0.01). This was the case also for masked hypertension (73.5±2.4 bursts per 100 heartbeats;
P
<0.01), the degree of the sympathetic activation being similar for magnitude to that seen in the other 2 hypertensive conditions. Compared with normotensive subjects, baroreflex-heart rate control was significantly attenuated in all of the hypertensive states, whereas baroreflex-sympathetic control was unaffected. Homeostasis model assessment index was increased in patients with in- and out-of-office and white-coat hypertension, with a further increase in masked hypertension and a direct relation with resting sympathetic nerve traffic (
r
=0.46;
P
<0.01). These data provide the first evidence that masked hypertension is characterized by a marked sympathetic overdrive. They further show that the neurogenic alterations are coupled with metabolic and baroreflex abnormalities.
Reconciling State Aid and Property Tax Relief for Urban Schools
Authors: Tae Ho Eom  , Killeen Kieran M.
Published: July 2007

Similar to many property tax relief programs, New York State's School Tax Relief (STAR) program has been shown to exacerbate school resource inequities across urban, suburban, and rural schools. STAR's inherent conflict with the wealth equalization policies of New York State's school finance system are highlighted in a manner that effectively penalizes large, urban school districts by not adjusting for factors likely to contribute to high property taxation. As a policy solution, this article presents results of a simulation that distributes property tax relief using an econometrically based cost index. The results substantially favor high-need urban and rural school districts.
Efficiency as a mediator in turnover—organizational performance relations
Authors: Morrow Paula , McElroy James
Published: July 2007

This study adds to scientific understanding of how employee turnover affects organizational performance in a multi-unit commercial bank setting operating in the United States. Theoretically, expected relationships among turnover, efficiency and performance are outlined. Empirically, two indicators of organizational efficiency are examined and one, cost-per-loan efficiency, is found to fully mediate relations between voluntary employee turnover and two organizational performance outcomes, profitability and customer satisfaction, in both synchronous and longitudinal analyses These results replicate recent findings in disparate industries, suggesting that efficiency may explain why higher levels of turnover are typically associated with lower levels of organizational performance. The need to distinguish among conceptualizations of efficiency is discussed, along with the need to consider temporal effects associated with turnover and efficiency.
Stretching out and expanding work practices in time and space: The case of telemedicine
Authors: Nicolini Davide
Published: July 2007

The article utilizes the imagery of stretching out and expanding for exploring what happens when medical practices and health working arrangements are temporally and spatially reconfigured. Based on the tenets of contemporary practice theory, and on the back of a three years' longitudinal study of telemedicine in northern Italy, the article investigates some of the practical issues raised by the subversion of the proximity principles that still underscore most current medical practices. The study argues that in order to cope with the expansion of their activity practitioners had to face three main practical problems: they had to redistribute their work and tasks among human and non-human elements, they had to reframe the ways in which the activity was made accountable, and they had to reconfigure the relationships between all those involved. The stretching out and expanding of medical practices in space and time implies thus much more than a simple redistribution of what was already there and it triggers profound changes which included the reframing of the object and content of the activity, the emergence of new artefacts and new identities, and the modification of the geography of the power positions between all those involved.
Is the natural PCDD/PCDF mixture toxic for human placental JEG-3 cell line? The action of the toxicants on hormonal profile, CYP1A1 activity, DNA damage and cell apoptosis
Authors: Augustowska Katarzyna , Magnowska Zofia , Kapiszewska Maria , Gregoraszczuk Ewa L.
Published: July 2007

The present study was conducted to define the action of a mixture obtained by the extraction and purification of real fly ash, on specific toxicity endpoints, such as hormonal secretion, CYP1A1 expression, DNA damage and cell apoptosis. JEG-3 cell line was exposed in vitro to different doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or Polychlorinated dibenzo-p-dioxin/Polychlorinated dibenzo-P-furan (PCDD/PCDF) mixture. Both TCDD and the mixture decreased hCG secretion, while inhibition of progesterone levels was noted only under the influence of TCDD. The changes in hormone production were not due to the action on cell viability. There were time-dependent differences in CYP1A1 expression in cells exposed to TCDD and PCDD/PCDF mixture. Both TCDD and PCDD/PCDF mixture did not induce the DNA damage, as evaluated by the comet assay. Significantly lower DNA migration from the head of comet into the comet tail was noted after the removal of reagents. The highest efficiency of this process was noted 4 h after the TCDD and 24 h after the PCDD/PCDF mixture removal. These results suggest that the DNA adducts and/or DNA—DNA cross-links were formed. Neither TCDD nor PCDD/PCDF mixture had any effect on cell apoptosis assessed by caspase-3 activity and Hoechst 33258. Taken together, these findings clearly indicate a weaker action of the mixture when compared with TCDD. However, in both cases, their action was not due to the induction of the DNA damage and subsequent cell apoptosis but due to a direct influence of these toxicants on placental hormone production. Human & Experimental Toxicology ( 2007) 26, 407—417
Exposure to persistent organochlorine pollutants and type 2 diabetes mellitus
Authors: Rignell-Hydbom Anna , Rylander Lars , Hagmar Lars
Published: July 2007

Persistent organochlorine pollutants (POPs), such aspolychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), dichloro diphenyl trichloroethane (DDT) and its major metabolite 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p' -DDE) have been associated with type 2 diabetes mellitus (T2DM) in recent epidemiological studies. We have analysed 2,2',4,4',5,5' -hexachlorobiphenyl (CB-153) and p,p'-DDE in 544 serum-samples from Swedish women with a median age of 50 years. The participants were asked if they had diabetesand if so, what type of diabetes, years since diagnosis and what kind of treatment they had. Associations between exposure and T2DM were analysed by logistic regression. Moreover, trends of T2DM prevalence were tested with Jonckheere-Terpstra' test. Sixteen of the 544 women (3%) had diabetes, of which15 were classified as T2DM. There was a significant associationwith T2DM for both CB-153 (an increase of 100ng/glipid corresponded to an odds ratio [OR] of 1. 6, 95% confidenceinterval [CI] 1. 0, 2. 7) and p,p9-DDE (OR 1. 3, 95%CI 1. 1, 1. 6). In addition, significant positive trends betweenquartiles of CB-153 and T2DM (P 5 0. 004) and p,p9-DDEand T2DM (P 5 0. 002) were observed. The study showsan association between POP serum concentrations andan increased prevalence of T2DM. Human & Experimental Toxicology (2007) 26, 447—451
Do Social Network Characteristics Predict Mammography Screening Practices?
Authors: Allen Jennifer D. , Stoddard Anne M. , Sorensen Glorian
Published: July 2007

Background: Many breast cancer outreach programs assume that dissemination of information through social networks and provision of social support will promote screening. The authors prospectively examined the relationship between social network characteristics and adherence to screening guidelines. Method: Employed women age 40 years and older completed baseline and 2-year follow-up assessments ( N = 1,475) as part of an intervention trial. The authors modeled screening adherence at follow-up as a function of social network characteristics at baseline. Results: Baseline adherence explained most of the variation in adherence at follow-up. For women age 40 to 51 years, having a mammogram at follow-up was predicted by encouragement by family and/or friends and subjective norms at baseline (odds ratio = 2.20 and 1.18, respectively). For women age 52 years and older, the perception that screening was normative was related to adherence at follow-up (odds ratio = 1.46). Conclusions: Previous mammography use is strongly predictive of future screening. Social network characteristics have a modest impact on screening. Outreach efforts should focus on those who have previously underutilized mammography.
Education service delivery
Authors: Allais Stephanie Matseleng
Published: July 2007

International trends towards outcomes-based qualifications frameworks as the drivers of educational reform fit in well with trends in service delivery and public sector reform. Education reform in South Africa provides a particularly interesting case study of this phenomenon, because of the very comprehensive outcomes-based national qualifications framework that was implemented shortly after the transition to democracy. Problems with the framework as a basis for education reform became rapidly apparent, and the system is now deadlocked in a series of unresolved policy reviews. A key to understanding this collapse is the role of knowledge in relation to education. The outcomes-based qualification framework approach turns out to have very little to do with education, and in fact to have the potential to increase educational inequalities, particularly in poor countries.
Modelling conditional covariance in the linear mixed model
Authors: Pan Jianxin , MacKenzie Gilbert
Published: July 2007

We provide a data-driven method for modelling the conditional, within-subject covariance matrix arising in linear mixed models (Laird and Ware, 1982). Given an agreed structure for the between-subject covariance matrix we use a regression equation approach to model the within-subject covariance matrix. Using an EM algorithm we estimate all of the parameters in the model simultaneously and obtain analytical expressions for the standard errors. By re-analyzing Kenward's (1987) cattle data, we compare our new model with classical menu-selection–based modelling techniques, demonstrating its superiority using the Bayesian Information Criterion. We also conduct a simulation study, which confirms our observational findings. The paper extends our previous covariance modeling work (Pan and MacKenzie, 2003, 2006) to the conditional covariance space of the linear mixed model (LMM).
Globalization, Habitus, and the Balletic Body
Authors: Wainwright Steven P. , Williams Clare , Turner Bryan S.
Published: July 2007

The aim in this article is to write an evocative ethnography of the embodiment of ballet as a cultural practice. The authors draw on their fieldwork at the Royal Ballet (London), where they conducted 20 in-depth interviews with ballet staff (and watched "the company at work" in class, rehearsal, and performance). They explored dancers' (n = 9) and ex-dancers' (who are now teachers, administrators, and character dancers; n = 11) perceptions of their bodies, dancing careers, and the major changes that have occurred in the world of ballet over their professional lives. They focus on their accounts of the homogenizing effects of globalization on the culture of the Royal Ballet. Although this research is set within the elite and narrow cultural field of dance, the authors hope that it is an interesting addition to broader debates on the interrelationships between individuals and institutions, the body and society, and globalization and culture.
Constitutive alternative NF-κB signaling promotes marginal zone B-cell development but disrupts the marginal sinus and induces HEV-like structures in the spleen
Authors: Guo Feng , Weih Debra , Meier Elke , Weih Falk
Published: July 2007

Nuclear factor-κB (NF-κB) plays a crucial role in B-cell and lymphoid organ development. Here, we studied the consequences of constitutive, signal-independent activation of the alternative NF-κB pathway for the splenic marginal zone (MZ). In contrast to nfkb2−/− mice, which lack both p100 and p52, mice that lack only the inhibitory p100 precursor but still express the p52 subunit of NF-κB2 (p100−/−) had markedly elevated MZ B-cell numbers. Both cell-intrinsic mechanisms and increased stromal expression of vascular cell adhesion molecule-1 (VCAM-1) contributed to the accumulation of MZ B cells in p100−/− spleens. While migration of p100−/− MZ B cells toward the lysophospholipid sphingosine-1 phosphate (S1P) was not affected, CXCL13-stimulated chemotaxis was impaired, correlating with reduced migration of MZ B cells into follicles in response to lipopolysaccharide (LPS). Strikingly, p100 deficiency resulted in the absence of a normal marginal sinus, strongly induced expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) and glycosylated cell adhesion molecule-1 (GlyCAM-1), and the formation of nonfunctional ectopic high endothelial venule (HEV)–like structures in the red pulp. Thus, constitutive activation of the alternative NF-κB pathway favors MZ B-cell development and accumulation but leads to a disorganized spleen microarchitecture.
A potent erythropoietin-mimicking human antibody interacts through a novel binding site
Authors: Liu Zhihong , Stoll Vincent S. , DeVries Peter J. , Jakob Clarissa G. , Xie Nancy , Simmer Robert L. , Lacy Susan E. , Egan David A. , Harlan John E. , Lesniewski Richard R. , Reilly Edward B.
Published: July 2007

Recombinant human erythropoietin (rHu-EPO) is used to treat anemia by activating the erythropoietin receptor (EPOR) in erythroid progenitor cells, leading to proliferation and differentiation into mature red blood cells. To allow less frequent dosing, a hyperglycosylated version of EPO has been developed with a longer half-life. In principle, an agonistic antibody targeting EPOR would offer an even longer half-life, support robust monthly dosing, and, unlike EPO products, reduce the risk of pure red cell aplasia. The efficiency of signaling and corresponding potency of previously reported antibody mimics are generally suboptimal compared with EPO and not suitable for clinical use. Here we describe a potent, fully human, agonistic antibody (ABT007) targeting EPOR that supports potent, more sustained, and less pulsatile elevation of hematocrit in a human EPOR–expressing transgenic mouse model compared with standard doses of rHu-EPO while requiring less frequent dosing. Resolution of the crystal structure of the EPOR extracellular domain (ECD) complexed to the ABT007 Fab fragment, determined at 0.32 nm, identifies a binding site that is consistent with a novel mechanism of receptor activation based on a unique antibody-imposed conformational change. These results demonstrate that a symmetric molecule can serve as a potent activator of the EPOR.
Development of Multiscale Biological Image Data Analysis: Review of 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics, Santa Barbara, USA (BII06)
Authors: Auer Manfred , Peng Hanchuan , Singh Ambuj
Published: July 2007

The 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics was held at Santa Barbara, on Sept 7–8, 2006. Based on the presentations at the workshop, we selected and compiled this collection of research articles related to novel algorithms and enabling techniques for bio- and biomedical image analysis, mining, visualization, and biology applications.
Enhanced effect of microdystrophin gene transfection by HSV-VP22 mediated intercellular protein transport
Authors: Xiong Fu , Xiao Shaobo , Yu Meijuan , Li Wanyi , Zheng Hui , Shang Yanchang , Peng Funing , Zhao Cuiping , Zhou Wenliang , Chen Huanchun , Fang Liurong , Chamberlain Jeffrey S , Zhang Cheng
Published: July 2007

Background

Duchenne musclar dystrophy (DMD) is an X-linked recessive disease caused by mutations of dystrophin gene, there is no effective treatment for this disorder at present. Plasmid-mediated gene therapy is a promising therapeutical approach for the treatment of DMD. One of the major issues with plasmid-mediated gene therapy for DMD is poor transfection efficiency and distribution. The herpes simplex virus protein VP22 has the capacity to spread from a primary transduced cell to surrounding cells and improve the outcome of gene transfer. To improve the efficiency of plasmid-mediated gene therapy and investigate the utility of the intercellular trafficking properties of VP22-linked protein for the treatment for DMD, expression vectors for C-terminal versions of VP22-microdystrophin fusion protein was constructed and the VP22-mediated shuttle effect was evaluated both in vitro and in vivo.

Results

Our results clearly demonstrate that the VP22-microdystrophin fusion protein could transport into C2C12 cells from 3T3 cells, moreover, the VP22-microdystrophin fusion protein enhanced greatly the amount of microdystrophin that accumulated following microdystrophin gene transfer in both transfected 3T3 cells and in the muscles of dystrophin-deficient (mdx) mice.

Conclusion

These results highlight the efficiency of the VP22-mediated intercellular protein delivery for potential therapy of DMD and suggested that protein transduction may be a potential and versatile tool to enhance the effects of gene delivery for somatic gene therapy of DMD.
Low enrolment in Ugandan Community Health Insurance Schemes: underlying causes and policy implications
Authors: Basaza Robert , Criel Bart , Van der Stuyft Patrick
Published: July 2007

Background

Despite the promotion of Community Health Insurance (CHI) in Uganda in the second half of the 90's, mainly under the impetus of external aid organisations, overall membership has remained low. Today, some 30,000 persons are enrolled in about a dozen different schemes located in Central and Southern Uganda. Moreover, most of these schemes were created some 10 years ago but since then, only one or two new schemes have been launched. The dynamic of CHI has apparently come to a halt.

Methods

A case study evaluation was carried out on two selected CHI schemes: the Ishaka and the Save for Health Uganda (SHU) schemes. The objective of this evaluation was to explore the reasons for the limited success of CHI. The evaluation involved review of the schemes' records, key informant interviews and exit polls with both insured and non-insured patients.

Results

Our research points to a series of not mutually exclusive explanations for this under-achievement at both the demand and the supply side of health care delivery. On the demand side, the following elements have been identified: lack of basic information on the scheme's design and operation, limited understanding of the principles underlying CHI, limited community involvement and lack of trust in the management of the schemes, and, last but not least, problems in people's ability to pay the insurance premiums. On the supply-side, we have identified the following explanations: limited interest and knowledge of health care providers and managers of CHI, and the absence of a coherent policy framework for the development of CHI.

Conclusion

The policy implications of this study refer to the need for the government to provide the necessary legislative, technical and regulative support to CHI development. The main policy challenge however is the need to reconcile the government of Uganda's interest in promoting CHI with the current policy of abolition of user fees in public facilities.
Plasma lyso-phosphatidylcholine concentration is decreased in cancer patients with weight loss and activated inflammatory status
Authors: Taylor Lenka A. , Arends Jann , Hodina Arwen K. , Unger Clemens , Massing Ulrich
Published: July 2007

Background

It has been observed that ras-transformed cell lines in culture have a higher phosphatidylcholine (PC) biosynthesis rate as well as higher PC-degradation rate (increased PC-turnover) than normal cells. In correspondence to these findings, the concentrations of the PC-degradation product lyso-phosphatidylcholine (LPC) in cancer patients were found to be decreased. Our objective was the systematic investigation of the relationship between LPC and inflammatory and nutritional parameters in cancer patients. Therefore, plasma LPC concentrations were assessed in 59 cancer patients and related to nutritional and inflammatory parameters. To determine LPC in blood plasma we developed and validated a HPTLC method.

Results

Average plasma LPC concentration was 207 ± 59 μM which corresponds to the lower limit of the reported range in healthy subjects. No correlation between LPC and age, performance status, body mass index (BMI) or fat mass could be seen. However, LPC correlated inversely with plasma C-reactive protein (CRP) and whole blood hydrogen peroxides (HPO). Further, a negative correlation could be observed between LPC and whole body extra cellular fluid volume (ECF) as well as with relative change in body weight since cancer diagnosis.

Conclusion

In conclusion, LPC concentrations were decreased in cancer patients. LPC plasma concentrations correlated with weight loss and inflammatory parameters and, therefore, might be a general indicator of severity of malignant disease.
Relaxin family peptide receptors Rxfp1 and Rxfp2: mapping of the mRNA and protein distribution in the reproductive tract of the male rat
Authors: Filonzi Marcelo , Cardoso Laís C , Pimenta Maristela T , Queiróz Daniel BC , Avellar Maria CW , Porto Catarina S , Lazari Maria FM
Published: July 2007

Background

Relaxin is the endogenous ligand of the G-protein coupled receptor RXFP1, previously known as LGR7. In humans relaxin can also activate, but with lower affinity, the closely related receptor for the insulin-like peptide from Leydig cells, RXFP2, previously known as LGR8. The lack of relaxin impairs male fertility but the precise distribution and the function of relaxin receptors in the male reproductive tract is not known. We investigated the distribution of Rxfp1 and Rxfp2 in the reproductive tract of the male rat and the function of relaxin in the vas deferens, a tissue with high expression of both receptors.

Methods

The presence of mRNA for Rxfp1 and Rxfp2 was investigated in testes, cultured Sertoli cells, epididymis, vas deferens, seminal vesicle, prostate, and spermatozoa by RT-PCR and Southern blot. Protein expression in the testis, vas deferens, primary culture of Sertoli cells, and spermatozoa was assessed by immunohistochemistry and immunofluorescence. The role of relaxin in the vas deferens was evaluated by contractility studies and radioimmunoassay of cAMP production. The effect of relaxin on mRNA levels for metalloproteinase-7 was measured by Northern blot.

Results

Transcripts for Rxfp1 and Rxfp2 were present in almost all parts of the male reproductive tract, with high levels in testis and vas deferens. Both receptors were immunolocalized in late stage germ cells but not in mature spermatozoa, although mRNAs for both receptors were also present in mature spermatozoa. Rxfp1 but not Rxfp2 was detected in cultured Sertoli cells. Strong immunostaining for Rxfp1 and Rxfp2 was seen in muscular and epithelial layers of the vas deferens and in arteriolar walls. Relaxin did not affect contractility and cyclic AMP production of the vas deferens, but increased the levels of mRNA for metalloproteinase-7.

Conclusion

Rxfp1 and Rxfp2 are widely and similarly distributed throughout the male reproductive tract. Our results suggest that Rxfp1 on spermatids and Sertoli cells may be important in spermatogenesis. Relaxin in the vas deferens does not affect contractility, but may affect vascular compliance and collagen and matrix remodeling.