bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential regulation of adipocyte PDE3B in distinct membrane compartments by insulin and the β3-adrenergic receptor agonist CL316243: effects of caveolin-1 knockdown on formation/maintenance of macromolecular signalling complexes
Authors: Ahmad Faiyaz , Lindh Rebecka , Tang Yan , Ruishalme Iida , Öst Anita , Sahachartsiri Bobby , Strålfors Peter , Degerman Eva , Manganiello Vincent C.
Published: September 2009

In adipocytes, PDE3B (phosphodiesterase 3B) is an important regulatory effector in signalling pathways controlled by insulin and cAMP-increasing hormones. Stimulation of 3T3-L1 adipocytes with insulin or the β3-adrenergic receptor agonist CL316243 (termed CL) indicated that insulin preferentially phosphorylated/activated PDE3B associated with internal membranes (endoplasmic reticulum/Golgi), whereas CL preferentially phosphorylated/activated PDE3B associated with caveolae. siRNA (small interfering RNA)-mediated KD (knockdown) of CAV-1 (caveolin-1) in 3T3-L1 adipocytes resulted in down-regulation of expression of membrane-associated PDE3B. Insulin-induced activation of PDE3B was reduced, whereas CL-mediated activation was almost totally abolished. Similar results were obtained in adipocytes from Cav-1-deficient mice. siRNA-mediated KD of CAV-1 in 3T3-L1 adipocytes also resulted in inhibition of CL-stimulated phosphorylation of HSL (hormone-sensitive lipase) and perilipin A, and of lipolysis. Superose 6 gel-filtration chromatography of solubilized membrane proteins from adipocytes stimulated with insulin or CL demonstrated the reversible assembly of distinct macromolecular complexes that contained 32P-phosphorylated PDE3B and signalling molecules thought to be involved in its activation. Insulin- and CL-induced macromolecular complexes were enriched in cholesterol, and contained certain common signalling proteins [14-3-3, PP2A (protein phosphatase 2A) and cav-1]. The complexes present in insulin-stimulated cells contained tyrosine-phosphorylated IRS-1 (insulin receptor substrate 1) and its downstream signalling proteins, whereas CL-activated complexes contained β3-adrenergic receptor, PKA-RII [PKA (cAMP-dependent protein kinase)-regulatory subunit] and HSL. Insulin- and CL-mediated macromolecular complex formation was significantly inhibited by CAV-1 KD. These results suggest that cav-1 acts as a molecular chaperone or scaffolding molecule in cholesterol-rich lipid rafts that may be necessary for the proper stabilization and activation of PDE3B in response to CL and insulin.
Experimental measurement of the total energy losses in a low pressure inductively coupled argon plasma
Authors: Lee Young-Kwang , Lee Min-Hyong , Chung Chin-Wook
Published: September 2009

Total energy losses per electron-ion pair lost (εT) were measured experimentally in a low pressure inductively coupled argon plasma. A floating probe working at very low bias voltage (∼1 V) was used to obtain the electron temperatures and plasma densities at the plasma-sheath boundary. εT was found from a power balance equation between the absorbed power and dissipated power by electrons and ions. At 10 mTorr, the measurement shows that the measured εT (∼100 V) gradually decreased with absorbed power, and this indicates that the ionization efficiency enhances by multistep ionizations. These εT are consistent with the theoretical results.
Tuning the transport and thermoelectric properties of In2O3 bulk ceramics through doping at In-site
Authors: Guilmeau E. , Bérardan D. , Simon Ch. , Maignan A. , Raveau B. , Ovono D. Ovono , Delorme F.
Published: September 2009

Bulk ceramics In2−xMxO3, with a metal-like behavior, have been synthesized in air for M=Ti4+, Zr4+, Sn4+, Ta5+, and Nb5+, with rather low solubility limits xℓ, ranging from 0.01 to 0.1. An abrupt increase in the electrical conductivity and of the carrier concentration with x is observed in the monophasic region (xxℓ) these values do not vary significantly. These results show that the valence of the doping element plays a crucial role in such properties, similar to degenerated semiconductors. Similarly, the thermopower |S| value is correlated with this evolution decreasing as x increases for x<xℓ. For the Sn doped samples, the maximum carrier concentration n=10.8×1020 cm−3 and electrical conductivity σ=5×103 S cm−1 are both achieved at x=0.06–0.1 (∼3–5 at. %) for a thermopower S of −20 μV/K at room temperature. In comparison, the minimum |S| and maxima σ and n of In2O3 compounds doped with the other cations occur at lower doping levels, e.g., xℓ∼0.02 and xℓ∼0.015 for Ti and Zr/Nb/Ta doped In2O3, respectively. The relationship between the values of room temperature Hall mobility and carrier concentration shows that numbers and/or effects of multicharged scattering centers of electrons are different depending on the doping element. In2O3 doped with M(IV) elements shows maximum values of mobility close to x=0.006, whereas the doping with M(V) cations induces a decrease in the Hall mobility even for small doping levels. The thermoelectric performances are significantly improved at these low doping levels, with ZT values close to 0.3 at 1000 K in the doped materials against 0.1 mW/mK2 for the undoped phase.
Magnetic force microscope tip-induced remagnetization of CoPt nanodisks with perpendicular anisotropy
Authors: Mironov V. L. , Gribkov B. A. , Vdovichev S. N. , Gusev S. A. , Fraerman A. A. , Ermolaeva O. L. , Shubin A. B. , Alexeev A. M. , Zhdan P. A. , Binns C.
Published: September 2009

We report on the results of a magnetic force microscopy investigation of remagnetization processes in arrays of CoPt nanodisks with diameters of 35 and 200 nm and a thickness of 9.8 nm fabricated by e-beam lithography and ion etching. The controllable magnetization reversal of individual CoPt nanodisks by the magnetic force microscope (MFM) tip-induced magnetic field was demonstrated. We observed experimentally two essentially different processes of tip-induced remagnetization. Magnetization reversal of 200 nm disks was observed when the probe moved across the particle while in case of 35 nm nanodisks one-touch remagnetization was realized. Micromagnetic modeling based on the Landau–Lifshitz–Gilbert (LLG) equation demonstrated that the tip-induced magnetization reversal occurs through the essentially inhomogeneous states. Computer simulations confirmed that in case of 200 nm disks the mechanism of embryo nucleation with reversed magnetization and further dynamic propagation following the probe moving across the particle was realized. On the other hand one-touch remagnetization of 35 nm disks occurs through the inhomogeneous vortexlike state. Micromagnetic LLG simulations showed that magnetization reversal in an inhomogeneous MFM probe field has a lower energy barrier in comparison with the mechanism of coherent rotation, which takes place in a homogeneous external magnetic field.
Macroscopic liquid phase separation of Fe–Sn immiscible alloy investigated by both experiment and simulation
Authors: Luo B. C. , Liu X. R. , Wei B.
Published: September 2009

The macroscopic phase separation of undercooled liquid Fe50Sn50 immiscible alloy was investigated by both drop tube experiment and the modified Model H. Core-shell structures with two, three, and five layers were formed during experiment. The concentric shells comprised of Fe-rich phase and Sn-rich phase distribute periodically in the solidified droplet, and the Sn-rich phase is always located at the sample surface owing to its smaller surface tension. The simulated results of modified Model H reproduce core-shell structures with the same layers, which justifies the prediction of this model. If the fluidity parameter Cf and solute concentration ϕ satisfy the physical conditions of both Cf<1 and 0<ϕ<0.45 or Cf≥1, the phase separation morphology exhibits the double-layer core-shell structure, whereas the multilayer core-shell structure is expected to form under the conditions of both Cf<1 and 0.45≤ϕ<0.5. The forming ability of core-shell structure for various immiscible alloys can be predicted accordingly.
Formation of creases on the surfaces of elastomers and gels
Authors: Hong Wei , Zhao Xuanhe , Suo Zhigang
Published: September 2009

When a block of an elastomer is bent, the compressed surface may form a crease. The critical strain for creasing measured experimentally is known to disagree with that predicted by linear perturbation analysis. This paper calculates the critical strain by comparing the elastic energy in a creased body and that in a smooth body. This difference in energy is expressed by a scaling relation. Critical conditions for creasing are determined for elastomers subject to general loads and gels swelling under constraint. The theoretical results are compared with existing experimental observations.
Single- and double-negative refractive indices of combined metamaterial structure
Authors: Tung N. T. , Lam V. D. , Park J. W. , Cho M. H. , Rhee J. Y. , Jang W. H. , Lee Y. P.
Published: September 2009

We experimentally and numerically studied the transmission spectra of a combined metamaterial structure whose negative refractive index was supposed to be achievable only with simultaneously negative permittivity and permeability. However, it was found that the negativity of the refractive index of such a structure could be obtained not only when both parameters were negative but also when only one parameter, more specifically the permittivity was negative. These characteristics of combined structure were analyzed in detail by using the standard retrieval effective-medium method. According to the analyses, it can be concluded that the negativity originates from the complex permittivity and permeability. The interplay among the real and the imaginary parts of those parameters is the key to the negative behavior of refractive index.
Spin canting and spin-flop transition in antiferromagnetic Cr2O3 nanocrystals
Authors: Li D. , Han Z. , Zheng J. G. , Wang X. L. , Geng D. Y. , Li J. , Zhang Z. D.
Published: September 2009

The structure and magnetic properties of Cr2O3 and Cr nanoparticles have been investigated. The as-prepared Cr nanoparticles show a core/shell structure, consisting of a Cr core and a thin Cr oxide shell with a thickness of 1.5–2.5 nm. Annealing the Cr nanoparticles in air leads to the formation of Cr2O3 nanoparticles with spherical morphology. The temperature dependence of the magnetization indicates that these Cr2O3 nanocrystals are antiferromagnetic below their Néel temperature of 320 K and undergo an antiferromagnetic to weak-ferromagnetic transition below about 140 K due to spin canting at disordered surfaces. Below 100 K, a spin-flop transition is induced by an external field with a critical field lower than about 7 T.
Exciton bound to a neutral donor in a parabolic quantum-well wire
Authors: Zhang Hong , Shen Man , Liu Jian-Jun
Published: September 2009

The properties of an exciton bound to a neutral donor (D0,X) in a parabolic GaAs quantum-well wire in the presence of a parallel magnetic field are investigated using the finite-difference method within the quasi-one-dimensional effective potential model. The magnetic field effects on the binding energy of the D0,X is studied for various parabolic potentials. The results show that high magnetic fields significantly increase the binding energy of the D0,X in the case of weak spatial confinement. In addition, we also found that with weak spatial confinement, the magnetic field has much stronger effects on the D0,X than it does on the biexciton, but with strong spatial confinement it has less effect.
Interband transitions of InAsxSb1−x alloy films
Authors: Kim T. J. , Yoon J. J. , Hwang S. Y. , Aspnes D. E. , Kim Y. D. , Kim H. J. , Chang Y. C. , Song J. D.
Published: September 2009

We report pseudodielectric-function spectra from 1.5 to 6.0 eV of InAsxSb1−x ternary alloys obtained by spectroscopic ellipsometry. Energies of the E1, E1+Δ1, E0′, E0′+Δ0′, E2, E2+Δ2, E2′, E2′+Δ2, and E1′ critical points (CPs) were obtained from numerically calculated second derivatives, and identifications established by band-structure calculations using the linear augmented Slater-type orbital method. The E2, E2+Δ2, E2′, and E2′+Δ2 CP structures cross with increasing As-composition. Two saddle-point transitions, Δ5cu-Δ5vu and Δ5cl−Δ5vu, are found for InSb.
Wavelength dependence of the damage threshold of inorganic materials under extreme-ultraviolet free-electron-laser irradiation
Authors: Hau-Riege S. P. , London R. A. , Bionta R. M. , Ryutov D. , Soufli R. , Bajt S. , McKernan M. A. , Baker S. L. , Krzywinski J. , Sobierajski R. , Nietubyc R. , Klinger D. , Pelka J. B. , Jurek M. , Juha L. , Chalupský J. , Cihelka J. , Hájková V. , Velyhan A. , Krása J. , Tiedtke K. , Toleikis S. , Wabnitz H. , Bergh M. , Caleman C. , Timneanu N.
Published: September 2009

We exposed bulk SiC and films of SiC and B4C to single 25 fs long free-electron-laser pulses with wavelengths between 13.5 and 32 nm. The materials are candidates for x-ray free-electron laser optics. We found that the threshold for surface-damage of the bulk SiC samples exceeds the fluence required for thermal melting at all wavelengths. The damage threshold of the film sample shows a strong wavelength dependence. For wavelengths of 13.5 and 21.7 nm, the damage threshold is equal to or exceeds the melting threshold, whereas at 32 nm the damage threshold falls below the melting threshold.
E
centers in ternary Si1−x−yGexSny random alloys
Authors: Chroneos A. , Jiang C. , Grimes R. W. , Schwingenschlögl U. , Bracht H.
Published: September 2009

Density functional theory calculations are used to study the association of arsenic (As) atoms to lattice vacancies and the formation of As-vacancy pairs, known as E centers, in the random Si0.375Ge0.5Sn0.125 alloy. The local environments are described by 32-atom special quasirandom structures that represent random Si1−x−yGexSny alloys. It is predicted that the nearest-neighbor environment will exert a strong influence on the stability of E centers in ternary Si0.375Ge0.5Sn0.125.
Nonpolar m-plane GaN on patterned Si(112) substrates by metalorganic chemical vapor deposition
Authors: Ni X. , Wu M. , Lee J. , Li X. , Baski A. A. , Özgür Ü. , Morkoç H.
Published: September 2009

The concept of nonpolar (11¯00) m-plane GaN on Si substrates has been demonstrated by initiating growth on the vertical (1¯1¯1) sidewalls of patterned Si(112) substrates using metalorganic chemical vapor deposition. The Si(112) substrates were wet-etched to expose {111} planes using stripe-patterned SiNx masks oriented along the [1¯10] direction. Only the vertical Si(1¯1¯1) sidewalls were allowed to participate in GaN growth by masking other Si{111} planes using SiO2, which led to m-plane GaN films. Growth initiating on the Si(1¯1¯1) planes normal to the surface was allowed to advance laterally and also vertically toward full coalescence. InGaN double heterostructure active layers grown on these m-GaN templates on Si exhibited two times higher internal quantum efficiencies as compared to their c-plane counterparts at comparable carrier densities. These results demonstrate a promising method to obtain high-quality nonpolar m-GaN films on large area, inexpensive Si substrates.
A biologically motivated signal transmission approach based on stochastic delay differential equation
Authors: Xu Mingdong , Wu Fan , Leung Henry
Published: September 2009

Based on the stochastic delay differential equation (SDDE) modeling of neural networks, we propose an effective signal transmission approach along the neurons in such a network. Utilizing the linear relationship between the delay time and the variance of the SDDE system output, the transmitting side encodes a message as a modulation of the delay time and the receiving end decodes the message by tracking the delay time, which is equivalent to estimating the variance of the received signal. This signal transmission approach turns out to follow the principle of the spread spectrum technique used in wireless and wireline wideband communications but in the analog domain rather than digital. We hope the proposed method might help to explain some activities in biological systems. The idea can further be extended to engineering applications. The error performance of the communication scheme is also evaluated here.
Are Long Commute Distances Inefficient and Disorderly?
Authors: O'Kelly Morton E , Niedzielski Michael A
Published: September 2009

By joining ideas from the spatial interaction and excess commuting literatures, we integrate and organize three related aspects of commuting statistics: trip length, distance decay, and entropy. We use concepts and calculations from the excess commuting literature to improve interpretation of trip length parameters in a doubly constrained trip distribution model. We derive a direct mathematical relationship between trip length and entropy, thereby providing an analytical model to calculate the ease with which trip lengths might be reduced. The new analysis not only ties these statistics together in a mathematically useful way, but also allows for a new entropy metric—relative entropy—that determines the organization (or lack thereof) of aggregate work trips. As a result, we disentangle the entropy component from the distance component and offer new perspectives on aggregate commuting in a comparative framework. Twenty-five cities are classified in an interesting and useful way that includes the average trip length and the degree of organization in each city.
Counteracting Path Dependencies: ‘Rational’ Investment Decisions in the Globalising Commercial Property Market
Authors: Fuchs Martina , Scharmanski André
Published: September 2009

The commercial property market is transforming from a locally embedded industry to an international one. In the neverending search for opportunities, an increasing number of investors are turning their attention to new, distant, and opaque property markets. Still largely unknown to the investors, such markets generate much uncertainty for decision making. Investors seek to overcome this by adopting new decision-making strategies based on economic models promising transparent optimum solutions. Using global office investors as an example, we show that these actors attempt to generate know-how systematically, to take better ‘rational’ decisions rooted in neoclassical economy and based on key performance indicators. However, we also highlight that the process of rational decision making contains some cracks in its edifice, thus providing space for path dependencies to intrude.
Autistic Autobiographies and More-Than-Human Emotional Geographies
Authors: Davidson Joyce , Smith Mick
Published: September 2009

This paper draws on an analysis of forty-five published autobiographical accounts of individuals with an autistic spectrum disorder (ASD) to highlight the important role of their, often intense, emotional relations to ‘natural’ things and places. In doing so, it offers a partial corrective to clinical and popular views of people with autism as almost entirely asocial and unconcerned with the beings and doings of others. A textual hermeneutic of the phenomenal insights reported by authors reveals instead that their personal geographies are characterized by rich, rewarding, and meaningful relationships with the wider more-than-human world, and that aspects of their lives can be undeniably, agreeably, ‘social’ in this broader sense. Such an analysis may offer important, albeit methodologically limited, insights into experiences of ASD while also challenging dominant understandings of ‘sociality’—in the sense of ‘being-with-others’—and of emotional involvement, that focus entirely on interactions between human beings. Indeed, to some extent, these emotionally charged experiences of the ‘natural’ world resonate with the feelings of many more neurotypical individuals.
Evaluation of the Variety of Plasmid Profiles in S epidermidis Isolates from Hospital Patients and Staff
Authors: Valentine Carrie R. , Yandle Susan H. , Marsik Frederic J. , Ebright Jack R. , Dawson Mark S.
Published: September 2009

Plasmid profiling was used to determine the variability of normal flora isolates of Staphylococcus epidermidis in order to evaluate the usefulness of plasmid profiling for identifying pathogens. Fifteen hospital staff members and patients repeatedly had cultures taken from the hands and nares, and multiple isolates were examined for plasmid profiles. S epidermidis isolated from the nares of 15 neonates were also examined. The total number of isolates examined for plasmid profiles was 726. Repetition of profiles was common among the different isolates from a single sampling (one swab). The frequency of re-isolating similar profiles on different days varied from 7% to 13%. Simultaneous isolation of similar profiles from nares and hands on the same individual varied from 0% to 11%, the percentage being lower for personnel. Isolation of the same plasmid profile from different individuals occurred only twice and resulted in an assignment probability of Pa = 0.002 for isolates obtained from different individuals. Significantly more isolates from nares contained plasmids (97%) compared with isolates from hands (89%).Patients who had two or more isolates of coagulase-negative staphylococci with similar profiles were judged, clinically, to have infections in 12 of 13 cases. However, the likelihood of re-isolating an S epidermidis strain with a similar plasmid profile twice from the same person at different times was sufficiently high to prevent plasmid profiling from being used as an absolute criterion for infection.
Management of Health Care Workers Remotely Vaccinated for Hepatitis B Who Sustain Significant Blood and Body Fluid Exposures
Authors: Snyder Michael B.
Published: September 2009

The availability of both plasma-derived and recombinant hepatitis B vaccines has given hospitals and other health care institutions the possibility of significantly reducing a major infectious hazard in the workplace. With the increasing use and acceptance of these vaccines, many employees who have a significant blood or body fluid exposure (percutaneous or mucous membrane) have already completed hepatitis B vaccination. Concerns have arisen over the duration of protection of vaccination, as it has been over five years since the introduction of the plasma-derived vaccine.
Respiratory Syncytial Virus
Authors: Sinnott John T. , Gilchrist Lindy S. , Ellis Leighton
Published: September 2009

Respiratory syncytial virus (RSV) is the most important cause of lower respiratory tract infection in outpatients, as well as the major viral cause of nosocomial illness in pediatric inpatients. Immunity to this common pathogen is short lived and reinfection can occur later in life, even into adulthood. Virtually all children have one infection before 24 months and 50% experience two or more episodes of infection. The attack rate is substantial with about half of all infants in a community becoming ill during the season's first epidemic. About 100,000 children in the US each year become ill enough to require hospitalization, the hospitalization rate being 1411,000 during epidemic periods. In certain locations, RSV accounts for about 45% of hospital admissions for respiratory disease in children under two years of age.
Subungual Bacteria of the Hand Contribution to the Glove Juice Test: Efficacy of Antimicrobial Detergents
Authors: Leyden J.J. , McGinley K.J. , Kates S.G. , Myung K.B.
Published: September 2009

Methodologies for evaluating the efficacy of antimicrobial agents in the bacterial flora of the hand involve variations of the “glove juice” or “sterile bag” procedures. In this study we demonstrate that the subungual flora contribute significantly to the recovery of bacteria in these procedures. Culturing hands that had the subungual spaces sealed with acrylic polish demonstrated a decay type of curve for the number of bacteria recovered in successive samplings with 106 colony forming units (CFU) bacteria recovered in the first sampling and 103 in the sixth while the opposite hand on which the subungual spaces were not sealed demonstrated a continuous recovery of 106 CFU.

Serial scrubbings of three minutes with plain detergent, 10% povidone-iodine or 4% chlorhexidine demonstrated a three logarithm reduction for povidone-iodine and four logarithm reduction compared to plain detergent alone for chlorhexidine in hands that had subungual spaces sealed, while the opposite hand showed only a 0.5 to 1.0 logarithm reduction. Povidone-iodine produced a 0.6 logarithm reduction and 4% chlorhexidine or 1.4 logarithm reduction in the density of subungual bacteria.
Nosocomial Bloodstream Infection at a Veterans Hospital; 1979 to 1987
Authors: Mylotte Joseph M. , White Donald , McDermott Carolyn , Hodan Carolyn
Published: September 2009

Studies of nosocomial bloodstream infection (NBI) have come primarily from university, municipal or community hospitals with little specific information from veterans hospitals. The objective of this study was to define trends in NBI at a tertiary care veterans hospital. Patients with NBI were identified by retrospective review of microbiology records and of infection control surveillance records from 1979 to 1987 at the Buffalo Veterans Administration Medical Center (VAMC). Between 1979 and 1985 there was no significant upward or downward trend. Beginning in early 1986 a significant increase in NBI was noted. This increase was because of changes in incidence of gram-positive NBI (primarily Streptococcus aureus and enterococcus) while there was no change in incidence of gram-negative NBI. The most common sources of NBI were similar to previous studies and included urinary tract infection, pneumonia, surgical wound infections and intravenous catheter related infections. The frequency of various organisms causing NBI was likewise similar to other studies except for pneumonia in which Streptococcus pneumoniae most commonly was isolated. The yearly incidence of gentamicin resistance among gram-negative NBI isolates demonstrated no significant trend. In conclusion, there was a significant increase in incidence of NBI at the Buffalo VAMC between 1979 and 1987 that occurred primarily in the last two years studied. The importance of gram-positive organisms as a cause of NBI at the Buffalo VAMC has been clearly documented as a recent phenomenon.
Annual Tuberculin Skin Testing of Employees at a University Hospital: A Cost-Benefit Analysis
Authors: Raad Issam , Cusick Janet , Sherertz Robert J. , Sabbagh Mouin , Howell Nora
Published: September 2009

The usefulness of routine annual tuberculin skin testing (purified protein derivative [PPD]) of hospital employees has been questioned. Between 1984 and the end of 1987 the PPD conversion rates of hospital employees at a university and psychiatric hospital in North Florida were compared. The number of employees in both hospitals were almost equal and compliance with the annual testing was more than 95%. In the psychiatric hospital tuberculosis screening of patients was practiced on admission and annually thereafter. Although no unsuspected smear-positive tuberculosis patients were diagnosed in the psychiatric hospital as compared to four in the university hospital, the annual conversion rates of employees were 0.42% and 0.13%, respectively (p>0.001). However, the ratios of these conversion rates to the incidence of tuberculosis in the counties where these hospitals are located respectively were similar (20.0 vs 24.3, p=0.7). The community seems be the major source of the PPD conversion. At the university hospital more than $70,000 was spent on the annual PPD testing to discover 15 converters; nine had no or minimal contact with patients and only two complied with isoniazid (INH) prophylaxis. Annual PPD testing is not cost effective in hospitals with a low annual conversion rate among its employees and with low tuberculosis case rates in the hospital and the surrounding community.
Nosocomial Group B Streptococcal Infections
Authors: Klein Natalie C. , Schoch Paul E. , Cunha Burke A.
Published: September 2009

Group B streptococci are the most frequent cause of life-threatening infections in newborn infants in the United States. The reservoir of this organism is thought to be the mother's vaginal or rectal microflora or both. Prevalence surveys have documented arriage rates ranging from 8% to 31%. Increased rates of vertical transmission are seen in infants born to women with dense vaginal colonization at delivery. In most cases, early onset group B streptococcal disease in neonates is diagnosed during the first day of life.' While the carrier rate may approach 30% in pregnant women, the incidence of serious disease in neonates is 0.2% to 0.4% with a mortality rate approaching 50% in some studies. Risk factors prominently associated with early onset group B streptococcal disease have been identified as premature labor, prolonged rupture of amniotic membranes and intrapartum fever.
Current Challenges and Future Opportunities
Authors: Bentley David W.
Published: September 2009

This article is the first in a new series entitled “Topics in Long-Term Care.” The author, a full-time academic physician, is based at a chronic disease hospital with a 577-bed nursing home where he is head of infectious diseases and, with the support of a full-time infection control officer (RN), manages the infection control programs as the hospital epidemiologist and chair of the infection control committee. Although most interest centers on the nursing home setting, the title reflects the need to consider all long-term care facilities (LTCFs) with special populations and risk factors for acquiring infection, e.g., rehabilitation units, day care centers and day hospitals for the elderly and institutions for developmental disabled persons of all ages.
Prevention of Catheter-Associated Urinary Tract Infection: A Cost-Benefit Analysis
Authors: Platt Richard , Frank Polk B. , Murdock Bridget , Rosner Bernard
Published: September 2009

A cost-benefit analysis was used to assess four strategies to prevent catheter-associated urinary tract infections in an acute care setting. Routine use of catheters with sealed collection junctions, selective use of these catheters, and oral antibiotic prophylaxis all result in fewer deaths, fewer infections, and lower overall costs than not using any of these. Routine use of sealed junction catheters results in fewer infections and deaths than does selective use. When the cost of a nosocomial urinary tract infection is $500, routine use of sealed junction catheters is also less expensive than selective use in many circumstances. Oral antibiotic prophylaxis would result in the lowest net cost and the fewest deaths and infections, if it were as effective as parenteral prophylaxis, if more than 72% of patients received it, and if important negative factors such as selection of antimicrobial resistance and adverse drug reactions are not considered. When there is no extra cost of sealed junction catheters, their use is less expensive than the oral prophylaxis strategy if the total cost of oral prophylaxis, including the cost of adverse reactions, is greater than $15. If the extra cost of sealed junction catheters is $4 per unit, their use is less expensive than oral prophylaxis when its cost exceeds $35. Prevention of catheter-associated urinary tract infection reduces the overall cost of patient care, even when the prevention itself incurs costs. This analysis supports the routine use of sealed junction catheters in most acute care situations that require indwelling catheter drainage. Currently, we do not recommend routine antibiotic prophylaxis.
Regulator of G protein signalling 16 is a target for a porcine circovirus type 2 protein
Authors: Timmusk Sirje , Merlot Elodie , Lövgren Tanja , Järvekülg Lilian , Berg Mikael , Fossum Caroline
Published: September 2009

Interaction studies have suggested that the non-structural protein encoded by open reading frame 3 (ORF3) of porcine circovirus type 2 (PCV2) binds specifically to a regulator of G protein signalling (RGS) related to human RGS16 (huRGS16). The full-length clone of RGS16 was generated from porcine cells and sequence analysis revealed a close relationship to huRGS16 and murine RGS16.In vitropull-down experiments verified an interaction between porcine RGS16 (poRGS16) and ORF3 from PCV2. Using GST-linked ORF3 proteins from three different genogroups of PCV2 and from porcine circovirus type 1 (PCV1) in the pull-down experiments indicated that there were differences in their ability to bind poRGS16. Quantitative RT-PCR demonstrated that the expression of poRGS16 mRNA could be induced by a number of cell activators including mitogens (LPS and PHA), interferon inducers (ODN 2216 and poly I : C) and the neurotransmitter norepinephrine. Immunofluorescence labelling confirmed the induced expression of poRGS16 at the protein level and suggested that the PCV2 ORF3 protein co-localized with poRGS16 in LPS-activated porcine PBMC. Furthermore, poRGS16 appeared to participate in the translocation of the ORF3 protein into the cell nucleus, suggesting that the observed interaction may play an important role in the infection biology of porcine circovirus.
Genetic analysis of the SPRN gene in ruminants reveals polymorphisms in the alanine-rich segment of shadoo protein
Authors: Stewart Paula , Shen Cuicui , Zhao Deming , Goldmann Wilfred
Published: September 2009

Prion diseases in ruminants, especially sheep scrapie, cannot be fully explained by PRNP genetics, suggesting the influence of a second modulator gene. The SPRN gene is a good candidate for this role. The SPRN gene encodes the shadoo protein (Sho) which has homology to the PRNP gene encoding prion protein (PrP). Murine Sho has a similar neuroprotective activity to PrP and SPRN gene variants are associated with human prion disease susceptibility. SPRN gene sequences were obtained from 14 species in the orders Artiodactyla and Rodentia. We report here the sequences of more than 20 different Sho proteins that have arisen due to single amino acid substitutions and amino acid deletions or insertions. All Sho sequences contained an alanine-rich sequence homologous to a hydrophobic region with amyloidogenic characteristics in PrP. In contrast with PrP, the Sho sequence showed variability in the number of alanine residues.
Novel cytomegaloviruses in free-ranging and captive great apes: phylogenetic evidence for bidirectional horizontal transmission
Authors: Leendertz Fabian H. , Deckers Merlin , Schempp Werner , Lankester Felix , Boesch Christophe , Mugisha Lawrence , Dolan Aidan , Gatherer Derek , McGeoch Duncan J. , Ehlers Bernhard
Published: September 2009

Wild great apes often suffer from diseases of unknown aetiology. This is among the causes of population declines. Because human cytomegalovirus (HCMV) is an important pathogen, especially in immunocompromised individuals, a search for cytomegaloviruses (CMVs) in deceased wild and captive chimpanzees, gorillas and orang-utans was performed. By using a degenerate PCR targeting four conserved genes (UL54–UL57), several distinct, previously unrecognized CMVs were found for each species. Sequences of up to 9 kb were determined for ten novel CMVs, located in the UL54–UL57 block. A phylogenetic tree was inferred for the ten novel CMVs, the previously characterized chimpanzee CMV, HCMV strains and Old World and New World monkey CMVs. The primate CMVs fell into four clades, containing New World monkey, Old World monkey, orang-utan and human CMVs, respectively, plus two clades that each contained both chimpanzee and gorilla isolates (termed CG1 and CG2). The tree loci of the first four clades mirrored those for their respective hosts in the primate tree, suggesting that these CMV lineages arose through cospeciation with host lineages. The CG1 and CG2 loci corresponded to those of the gorilla and chimpanzee hosts, respectively. This was interpreted as indicating that CG1 and CG2 represented CMV lineages that had arisen cospeciationally with the gorilla and chimpanzee lineages, respectively, with subsequent transfer within each clade between the host genera. Divergence dates were estimated and found to be consistent with overall cospeciational development of major primate CMV lineages. However, CMV transmission between chimpanzees and gorillas in both directions has also occurred.
Predominance of hepatitis C virus genotype 4 infection and rapid transmission between 1935 and 1965 in the Central African Republic
Authors: Njouom Richard , Frost Eric , Deslandes Sylvie , Mamadou-Yaya Fleurie , Labbé Annie-Claude , Pouillot Régis , Mbélesso Pascal , Mbadingai Sylvestre , Rousset Dominique , Pépin Jacques
Published: September 2009

The molecular epidemiology of hepatitis C virus (HCV) in the Central African Republic (CAR) is poorly documented. Thus, we conducted phylogenetic analyses of NS5B gene sequences from 58 HCV-infected inhabitants of a remote area of south-west CAR, which indicated that 48 (82.8 %) were infected with genotype 4 (HCV-4), five (8.6 %) with genotype 2 and five (8.6 %) with genotype 1. HCV-4 strains were highly heterogeneous, containing previously described subtypes 4k (48 %), 4c (27 %), 4r (4 %), 4f (4 %) and unclassified subtypes (17 %). To estimate the epidemic history of these HCV-4 strains, an evolutionary analysis using the coalescent approach was used. The estimated date of the most recent common ancestor of the CAR HCV-4 strains was 1539 (95 % confidence intervals, 1317–1697). They exhibited a rapid, exponential spread from 1935 to 1965, simultaneously with what was recently reported in neighbouring Cameroon and Gabon. The hypothesis of a massive iatrogenic transmission during interventions for the control of endemic tropical diseases is discussed.
Vaccination against porcine parvovirus protects against disease, but does not prevent infection and virus shedding after challenge infection with a heterologous virus strain
Authors: Jóźwik A. , Manteufel J. , Selbitz H.-J. , Truyen U.
Published: September 2009

The demonstration of field isolates of porcine parvovirus (PPV) that differ genetically and antigenically from vaccine strains of PPV raises the question of whether the broadly used inactivated vaccines can still protect sows against the novel viruses. Ten specific-pathogen-free primiparous sows were assigned to three groups and were vaccinated with one of two vaccines based on the old vaccine strains, or served as non-vaccinated controls. After insemination, all sows were challenged with the prototype genotype 2 virus, PPV-27a, on gestation day 41; fetuses were delivered on gestation day 90 and examined for virus infection. The fetuses of the vaccinated sows were protected against disease, but both the vaccinated and the non-vaccinated sows showed a marked increase in antibody titres after challenge infection, indicating replication of the challenge virus. All sows (vaccinated and non-vaccinated) shed the challenge virus for at least 10 days after infection, with no difference in the pattern or duration of virus shedding.
Identification of a novel human gammapapillomavirus species
Authors: Li Linlin , Barry Pennan , Yeh Elaine , Glaser Carol , Schnurr David , Delwart Eric
Published: September 2009

By using random PCR amplification, shotgun sequencing and sequence similarity searches, we analysed nucleic acids present in cell cultures inoculated with samples from unexplained cases of encephalitis. We identified a divergent human papillomavirus (HPV) sequence originating from a rectal swab. The full genome was amplified by inverse PCR and sequenced. The prototype of the sixth gammapapillomavirus species, HPV116, was not found in the patient's cerebrospinal fluid or respiratory secretions, nor in culture supernatants from other unexplained cases of encephalitis, indicating that its identification in an encephalitis patient was accidental.
New insights into processing of bovine viral diarrhea virus glycoproteins Erns and E1
Authors: Wegelt Anne , Reimann Ilona , Zemke Johanna , Beer Martin
Published: September 2009

Bovine viral diarrhea virus (BVDV) is a member of the genusPestiviruswithin the familyFlaviviridae. Its single-stranded RNA encodes a polyprotein that is cleaved co- and post-translationally by viral and cellular proteases. However, the cleavage between the envelope proteins Ernsand E1 is still unexplained. In this study, an Erns–E1 protein could be identified and characterized with a new E1-specific antiserum. With bicistronic constructs bearing a deletion in the Erns-encoding region and expressing Ernsor the Erns–E1 protein, it could be shown that this protein is not essential for virus replication. Furthermore, two putative cleavage sites were mutated in eukaryotic expression plasmids, as well as in full-length cDNA constructs. The mutation of position P3 of a potential signal peptide peptidase site abolished cleavage completely and no infectious virus progeny could be observed, indicating that cleavage of the Erns–E1 protein is indispensable for virus growth.
Protective effect of the T112 PrP variant in sheep challenged with bovine spongiform encephalopathy
Authors: Saunders G. C. , Lantier I. , Cawthraw S. , Berthon P. , Moore S. J. , Arnold M. E. , Windl O. , Simmons M. M. , Andréoletti O. , Bellworthy S. , Lantier F.
Published: September 2009

Sheep with an ARQ/ARQ PRNP genotype at codon positions 136/154/171 are highly susceptible to experimental infection with bovine spongiform encephalopathy (BSE). However, a number of sheep challenged orally or intracerebrally with BSE were clinically asymptomatic and found to survive or were diagnosed as BSE-negative when culled. Sequencing of the full PRNP gene open reading frame of BSE-susceptible and -resistant sheep indicated that, in the majority of Suffolk sheep, resistance was associated with an M112T PRNP variant (TARQ allele). A high proportion (47 of 49; 96 %) of BSE-challenged wild-type (MARQ/MARQ) Suffolk sheep were BSE-infected, whereas none of the 20 sheep with at least one TARQ allele succumbed to BSE. Thirteen TARQ-carrying sheep challenged with BSE are still alive and some have survival periods equivalent to, or greater than, reported incubation periods of BSE in ARR/ARR and VRQ/VRQ sheep.
Quantitative evaluation of the role of Epstein–Barr virus immediate-early protein BZLF1 in B-cell transformation
Authors: Katsumura Koichi Ricardo , Maruo Seiji , Wu Yi , Kanda Teru , Takada Kenzo
Published: September 2009

The Epstein–Barr virus (EBV) immediate-early transactivator BZLF1 plays a key role in switching EBV infection from the latent to the lytic form by stimulating the expression cascade of lytic genes; it also regulates the expression of several cellular genes. Recently, we reported that BZLF1 is expressed in primary human B cells early after EBV infection. To investigate whether this BZLF1 expression early after infection plays a role in the EBV-induced growth transformation of primary B cells, we generated BZLF1-knockout EBV and quantitatively evaluated its transforming ability compared with that of wild-type EBV. We found that the 50 % transforming dose of BZLF1-knockout EBV was quite similar to that of wild-type EBV. Established lymphoblastoid cell lines (LCLs) harbouring BZLF1-knockout EBV were indistinguishable from LCLs harbouring wild-type EBV in their pattern of latent gene expression and in their growthin vitro. Furthermore, the copy numbers of EBV episomes were very similar in the LCLs harbouring BZLF1-knockout EBV and in those harbouring wild-type EBV. These data indicate that disrupting BZLF1 expression in the context of the EBV genome, and the resultant inability to enter lytic replication, have little impact on the growth of LCLs and the steady-state copy number of EBV episomes in established LCLs.
Diverse circovirus-like genome architectures revealed by environmental metagenomics
Authors: Rosario Karyna , Duffy Siobain , Breitbart Mya
Published: September 2009

Single-stranded DNA (ssDNA) viruses with circular genomes are the smallest viruses known to infect eukaryotes. The present study identified 10 novel genomes similar to ssDNA circoviruses through data-mining of public viral metagenomes. The metagenomic libraries included samples from reclaimed water and three different marine environments (Chesapeake Bay, British Columbia coastal waters and Sargasso Sea). All the genomes have similarities to the replication (Rep) protein of circoviruses; however, only half have genomic features consistent with known circoviruses. Some of the genomes exhibit a mixture of genomic features associated with different families of ssDNA viruses (i.e. circoviruses, geminiviruses and parvoviruses). Unique genome architectures and phylogenetic analysis of the Rep protein suggest that these viruses belong to novel genera and/or families. Investigating the complex community of ssDNA viruses in the environment can lead to the discovery of divergent species and help elucidate evolutionary links between ssDNA viruses.
Immune control of mammalian gamma-herpesviruses: lessons from murid herpesvirus-4
Authors: Stevenson P. G. , Simas J. P. , Efstathiou S.
Published: September 2009

Many acute viral infections can be controlled by vaccination; however, vaccinating against persistent infections remains problematic. Herpesviruses are a classic example. Here, we discuss their immune control, particularly that of gamma-herpesviruses, relating the animal model provided by murid herpesvirus-4 (MuHV-4) to human infections. The following points emerge: (i) CD8+T-cell evasion by herpesviruses confers a prominent role in host defence on CD4+T cells. CD4+T cells inhibit MuHV-4 lytic gene expression via gamma-interferon (IFN-γ). By reducing the lytic secretion of immune evasion proteins, they may also help CD8+T cells to control virus-driven lymphoproliferation in mixed lytic/latent lesions. Similarly, CD4+T cells specific for Epstein–Barr virus lytic antigens could improve the impact of adoptively transferred, latent antigen-specific CD8+T cells. (ii) In general, viral immune evasion necessitates multiple host effectors for optimal control. Thus, subunit vaccines, which tend to prime single effectors, have proved less successful than attenuated virus mutants, which prime multiple effectors. Latency-deficient mutants could make safe and effective gamma-herpesvirus vaccines. (iii) The antibody response to MuHV-4 infection helps to prevent disease but is suboptimal for neutralization. Vaccinating virus carriers with virion fusion complex components improves their neutralization titres. Reducing the infectivity of herpesvirus carriers in this way could be a useful adjunct to vaccinating naive individuals with attenuated mutants.
Identification of a novel herpes simplex virus type 1 transcript and protein (AL3) expressed during latency
Authors: Jaber Tareq , Henderson Gail , Li Sumin , Perng Guey-Chuen , Carpenter Dale , Wechsler Steven L. , Jones Clinton
Published: September 2009

The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) is abundantly expressed in latently infected sensory neurons. In small animal models of infection, expression of the first 1.5 kb of LAT coding sequences is necessary and sufficient for wild-type reactivation from latency. The ability of LAT to inhibit apoptosis is important for reactivation from latency. Within the first 1.5 kb of LAT coding sequences and LAT promoter sequences, additional transcripts have been identified. For example, the anti-sense to LAT transcript (AL) is expressed in the opposite direction to LAT from the 5′ end of LAT and LAT promoter sequences. In addition, the upstream of LAT (UOL) transcript is expressed in the LAT direction from sequences in the LAT promoter. Further examination of the first 1.5 kb of LAT coding sequences revealed two small ORFs that are anti-sense with respect to LAT (AL2 and AL3). A transcript spanning AL3 was detected in productively infected cells, mouse neuroblastoma cells stably expressing LAT and trigeminal ganglia (TG) of latently infected mice. Peptide-specific IgG directed against AL3 specifically recognized a protein migrating near 15 kDa in cells stably transfected with LAT, mouse neuroblastoma cells transfected with a plasmid containing the AL3 ORF and TG of latently infected mice. The inability to detect the AL3 protein during productive infection may have been because the 5′ terminus of the AL3 transcript was downstream of the first in-frame methionine of the AL3 ORF during productive infection.