bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface electrical conductivity in ultrathin single-wall carbon nanotube/polymer nanocomposite films
Authors: Bliznyuk Valery , Singamaneni Srikanth , Kattumenu Ramesh , Atashbar Massood
Published: April 2006

Ultrathin composite films of single-wall carbon nanotubes dispersed in polymer matrices of polystyrene and polyurethane elastomers with the thickness ranging from 100nmto3μm were formed by dip-coating procedure. Electrical conductivity in plane of the film was measured with application of silver electrodes deposited through shadow mask techniques at polymer-air and polymer-substrate interfaces. Peculiarities of the surface electrical conductivity in the nanocomposite films have been related to the surface free energy of the components and the strength of polymer-substrate interfacial interaction, which promotes a nonuniform distribution of the conductive filler within the film thickness (vertical phase separation).
Photoacoustic imaging in biomedicine
Authors: Xu Minghua , Wang Lihong V.
Published: April 2006

Photoacoustic imaging (also called optoacoustic or thermoacoustic imaging) has the potential to image animal or human organs, such as the breast and the brain, with simultaneous high contrast and high spatial resolution. This article provides an overview of the rapidly expanding field of photoacoustic imaging for biomedical applications. Imaging techniques, including depth profiling in layered media, scanning tomography with focused ultrasonic transducers, image forming with an acoustic lens, and computed tomography with unfocused transducers, are introduced. Special emphasis is placed on computed tomography, including reconstruction algorithms, spatial resolution, and related recent experiments. Promising biomedical applications are discussed throughout the text, including (1) tomographic imaging of the skin and other superficial organs by laser-induced photoacoustic microscopy, which offers the critical advantages, over current high-resolution optical imaging modalities, of deeper imaging depth and higher absorption contrasts, (2) breast cancer detection by near-infrared light or radio-frequency–wave-induced photoacoustic imaging, which has important potential for early detection, and (3) small animal imaging by laser-induced photoacoustic imaging, which measures unique optical absorption contrasts related to important biochemical information and provides better resolution in deep tissues than optical imaging.
Linear photon upconversion of 400meV in an AlGaInP∕GaInP quantum well heterostructure to visible light at room temperature
Authors: Olson M. R. , Russell K. J. , Narayanamurti V. , Olson J. M. , Appelbaum Ian
Published: April 2006

We linearly up convert photons from 820to650nm, an energy change of ∼400meV, using a AlGaInP∕GaInP quantum well heterostructure. Current and luminescence-voltage measurements are presented at temperatures from 6to300K. Photoexcited electrons are injected into the semiconductor from the Au Schottky and a forward bias across the p+-i-n heterostructure drifts electrons into the GaInP quantum well. Holes diffuse from the heavily doped substrate and radiatively recombine, emitting ∼650nm light. Linear upconversion is verified by injecting hot electrons with a solid-state tunnel junction. This device encourages other technologies, including night-vision aids and thermal energy converters.
Enhanced emission from Si-based light-emitting diodes using surface plasmons
Authors: Pillai S. , Catchpole K. R. , Trupke T. , Zhang G. , Zhao J. , Green M. A.
Published: April 2006

Excitation of surface plasmons on metallic nanoparticles has potential for increasing the absorption and emission from thin Si devices. We report an eight-fold enhancement in electroluminescence from silicon-on-insulator light-emitting diodes at 900nm via excitation of surface plasmon resonance in silver nanoparticles, along with a redshift in the electroluminescence by 70nm by overcoating the nanoparticles with ZnS. The enhancement is due to coupling between the electromagnetic excitations of the silver nanoparticles and the waveguide modes.
Refractive index dependence of the absorption and emission cross sections at 1.54μm of Er3+ coupled to Si nanoclusters
Authors: Daldosso N. , Navarro-Urrios D. , Melchiorri M. , Pavesi L. , Sada C. , Gourbilleau F. , Rizk R.
Published: April 2006

Absorption coefficient (αabs) of Er3+ ions coupled to Si nanoclusters (Si-nc) in SiO2 has been determined by optical transmission measurements in rib-loaded waveguides characterized by different refractive indices, thus gauging an Er3+ absorption cross section (σabs) of 0.4–1.2×10−20cm2 at 1534nm. Although no significant enhancement due to the presence of Si-nc was observed, a clear dependence on the refractive index has been found. Measurements of the decay lifetime permit one to model the behavior as due to both local and mean field variations caused by the composite nature of the core waveguide layer.
Pixel-isolation walls of liquid crystal display formed by fluorinated UV-curable polymers
Authors: Baek Jong-In , Shin Jong-Ha , Oh Min-Cheol , Kim Jae Chang , Yoon Tae-Hoon
Published: April 2006

A pixel isolation wall of liquid crystal display is fabricated by utilizing the excellent phase separation between liquid crystal molecules and fluorinated UV-curable polymers. Due to the strong immiscibility of the fluorinated monomers, the segregation of the material occurs effectively to form a polymer wall during the UV exposure. Twisted nematic liquid crystal cells with fluorinated polymer wall are fabricated for the comparison with other devices made of ordinary polymer wall. The fluorinated polymer wall device exhibits enhancement of contrast due to the suppression of the light leakage through the polymer wall as well as reduced saturation voltage by anchoring enhancement.
Characteristics of GaMnN based ferromagnetic resonant tunneling diode without external magnetic field
Authors: Li M. K. , Kim N. M. , Lee S. J. , Jeon H. C. , Kang T. W.
Published: April 2006

Achievement of a spin polarization without magnetic field through a GaMnN based ferromagnetic resonant tunneling diode (RTD) is proposed theoretically. The influences of the temperature and structure on the spin polarization current and differential conductance have been investigated. The clear spin splitting current can be observed in an optimal RTD structure without magnetic field even though the splitting energy of the ferromagnetic barrier is very small. Large spin polarization can be obtained and the polarization orientation can be varied by an applied bias voltage without external magnetic field.
Increased efficiency in multijunction solar cells through the incorporation of semimetallic ErAs nanoparticles into the tunnel junction
Authors: Zide J. M. O. , Kleiman-Shwarsctein A. , Strandwitz N. C. , Zimmerman J. D. , Steenblock-Smith T. , Gossard A. C. , Forman A. , Ivanovskaya A. , Stucky G. D.
Published: April 2006

We report the molecular beam epitaxy growth of Al0.3Ga0.7As∕GaAs multijunction solar cells with epitaxial, semimetallic ErAs nanoparticles at the interface of the tunnel junction. The states provided by these nanoparticles reduce the bias required to pass current through the tunnel junction by three orders of magnitude, and therefore drastically reduce the voltage losses in the tunnel junction. We have measured open-circuit voltages which are 97% of the sum of the constituent cells, which result in nearly double the efficiency of our multijunction cell with a conventional tunnel junction.
Superconductivity in epitaxial thin films of NaxCoO2∙yD2O
Authors: Krockenberger Y. , Fritsch I. , Christiani G. , Habermeier H.-U. , Yu Li , Bernhard C. , Keimer B. , Alff L.
Published: April 2006

The observation of superconductivity in the layered transition metal oxide NaxCoO2∙yH2O [K. Takada et al., Nature (London) 422, 53 (2003)] has caused a tremendous upsurge of scientific interest due to its similarities and its differences to the copper based high-temperature superconductors. Two years after the discovery, we report the fabrication of single-phase superconducting epitaxial thin films of Na0.3CoO2∙1.3D2O grown by pulsed laser deposition technique. This opens additional roads for experimental research exploring the superconducting state and the phase diagram of this unconventional material.
Lack of IL-15 results in the suboptimal priming of CD4+T cell response against an intracellular parasite
Authors: Combe Crescent L. , Moretto Magali M. , Schwartzman Joseph D. , Gigley Jason P. , Bzik David J. , Khan Imtiaz A.
Published: April 2006

IFN-γ-producing CD4+T cells, although important for protection against acuteToxoplasma gondiiinfection, can cause gut pathology, which may prove to be detrimental for host survival. Here we show that mice lacking IL-15 gene develop a down-regulated IFN-γ-producing CD4+T cell response against the parasite, which leads to a reduction in gut necrosis and increased level of survival against infection. Moreover, transfer of immune CD4+T cells from WT to IL-15−/−mice reversed inhibition of gut pathology and caused mortality equivalent to levels of parental WT mice. Down-regulated CD4+T cell response in the absence of IL-15, manifested as reduced antigen-specific proliferation, was due to defective priming of the T cell subset by dendritic cells (DCs) of these animals. When stimulated with antigen-pulsed DCs from WT mice, CD4+T cells from IL-15−/−mice were primed optimally, and robust proliferation of these cells was observed. A defect in the DCs of knockout mice was further confirmed by their reduced ability to produce IL-12 upon stimulation withToxoplasmalysate antigen. Addition of exogenous IL-15 to DC cultures from knockout mice led to increased IL-12 production by these cells and restored their ability to prime an optimal parasite-specific CD4+T cell response. To our knowledge, this is the first demonstration of the role of IL-15 in the development of CD4+T cell immunity against an intracellular pathogen. Furthermore, based on these observations, targeting of IL-15 should have a beneficial effect on individuals suffering from CD4+T cell-mediated autoimmune diseases.
Defocused orientation and position imaging (DOPI) of myosin V
Authors: Toprak Erdal , Enderlein Joerg , Syed Sheyum , McKinney Sean A. , Petschek Rolfe G. , Ha Taekjip , Goldman Yale E. , Selvin Paul R.
Published: April 2006

The centroid of a fluorophore can be determined within ≈1.5-nm accuracy from its focused image through fluorescence imaging with one-nanometer accuracy (FIONA). If, instead, the sample is moved away from the focus, the point-spread-function depends on both the position and 3D orientation of the fluorophore, which can be calculated by defocused orientation and position imaging (DOPI). DOPI does not always yield position accurately, but it is possible to switch back and forth between focused and defocused imaging, thereby getting the centroid and the orientation with precision. We have measured the 3D orientation and stepping behavior of single bifunctional rhodamine probes attached to one of the calmodulins of the light-chain domain (LCD) of myosin V as myosin V moves along actin. Concomitant with large and small steps, the LCD rotates and then dwells in the leading and trailing position, respectively. The probe angle relative to the barbed end of the actin (β) averaged 128° while the LCD was in the leading state and 57° in the trailing state. The angular difference of 71° represents rotation of LCD around the bound motor domain and is consistent with a 37-nm forward step size of myosin V. When β changes, the probe rotates ±27° azimuthally around actin and then rotates back again on the next step. Our results remove degeneracy in angles and the appearance of nontilting lever arms that were reported.
Single-cell analysis of normal and FOXP3-mutant human T cells: FOXP3 expression without regulatory T cell development
Authors: Gavin Marc A. , Torgerson Troy R. , Houston Evan , deRoos Paul , Ho William Y. , Stray-Pedersen Asbjørg , Ocheltree Elizabeth L. , Greenberg Philip D. , Ochs Hans D. , Rudensky Alexander Y.
Published: April 2006

Forkhead winged-helix transcription factor Foxp3 serves as the dedicated mediator of the genetic program governing CD25+CD4+regulatory T cell (Tr) development and function in mice. In humans, its role in mediating Trdevelopment has been controversial. Furthermore, the fate of Trprecursors in FOXP3 deficiency has yet to be described. Making use of flow cytometric detection of human FOXP3, we have addressed the relationship between FOXP3 expression and human Trdevelopment. Unlike murine Foxp3−T cells, a small subset of human CD4+and CD8+T cells transiently up-regulated FOXP3 uponin vitrostimulation. Induced FOXP3, however, did not alter cell-surface phenotype or suppress T helper 1 cytokine expression. Furthermore, onlyex vivoFOXP3+Trcells persisted after prolonged culture, suggesting that induced FOXP3 did not activate a Trdevelopmental program in a significant number of cells. FOXP3 flow cytometry was also used to further characterize several patients exhibiting symptoms of immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) with or withoutFOXP3mutations. Most patients lacked FOXP3-expressing cells, further solidifying the association between FOXP3 deficiency and immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome. Interestingly, one patient bearing aFOXP3mutation enabling expression of stable FOXP3mutprotein exhibited FOXP3mut-expressing cells among a subset of highly activated CD4+T cells. This observation raises the possibility that the severe autoimmunity in FOXP3 deficiency can be attributed, in part, to aggressive T helper cells that have developed from Trprecursors.
Monte Carlo simulations of proton pumps: On the working principles of the biological valve that controls proton pumping in cytochrome
c
oxidase
Authors: Olsson Mats H. M. , Warshel Arieh
Published: April 2006

Gaining a detailed understanding of the proton-pumping process in cytochrome
c
oxidase (COX) is one of the challenges of modern biophysics. Recent mutation experiments have highlighted this challenge by showing that a single mutation (the N139D mutation) blocks the overall pumping while continuing to channel protons to the binuclear center without inhibiting the oxidase activity. Rationalizing this result has been a major problem because the mutation is quite far from E286, which is believed to serve as the branching point for the proton transport in the pumping process. In the absence of a reasonable explanation for this important observation, we have developed a Monte Carlo simulation method that can convert mutation and structural information to pathways for proton translocation and simulate the pumping process in COX on a millisecond and even subsecond time scale. This tool allows us to reproduce and propose a possible explanation to the effect of the N139D mutation and to offer a consistent model for the origin of the “valve effect” in COX, which is crucial for maintaining uphill proton pumping. Furthermore, obtaining the first structure-based simulation of proton pumping in COX, or in any other protein, indicates that our approach should provide a powerful tool for verification of mechanistic hypotheses about the action of proton transport proteins.
Limited evolutionary conservation of imprinting in the human placenta
Authors: Monk D. , Arnaud P. , Apostolidou S. , Hills F. A. , Kelsey G. , Stanier P. , Feil R. , Moore G. E.
Published: April 2006

The epigenetic phenomenon of genomic imprinting provides an additional level of gene regulation that is confined to a limited number of genes, frequently, but not exclusively, important for embryonic development. The evolution and maintenance of imprinting has been linked to the balance between the allocation of maternal resources to the developing fetus and the mother's well being. Genes that are imprinted in both the embryo and extraembryonic tissues show extensive conservation between a mouse and a human. Here we examine the human orthologues of mouse genes imprinted only in the placenta, assaying allele-specific expression and epigenetic modifications. The genes from the
KCNQ1
domain and the isolated human orthologues of the imprinted genes
Gatm
and
Dcn
all are expressed biallelically in the human, from first-trimester trophoblast through to term. This lack of imprinting is independent of promoter CpG methylation and correlates with the absence of the allelic histone modifications dimethylation of lysine-9 residue of H3 (H3K9me2) and trimethylation of lysine-27 residue of H3 (H3K27me3). These specific histone modifications are thought to contribute toward regulation of imprinting in the mouse. Genes from the
IGF2R
domain show polymorphic concordant expression in the placenta, with imprinting demonstrated in only a minority of samples. Together these findings have important implications for understanding the evolution of mammalian genomic imprinting. Because most human pregnancies are singletons, this absence of competition might explain the comparatively relaxed need in the human for placental-specific imprinting.
Direct electrical detection of DNA synthesis
Authors: Pourmand Nader , Karhanek Miloslav , Persson Henrik H. J. , Webb Chris D. , Lee Thomas H. , Zahradníková Alexandra , Davis Ronald W.
Published: April 2006

Rapid, sequence-specific DNA detection is essential for applications in medical diagnostics and genetic screening. Electrical biosensors that use immobilized nucleic acids are especially promising in these applications because of their potential for miniaturization and automation. Current DNA detection methods based on sequencing by synthesis rely on optical readouts; however, a direct electrical detection method for this technique is not available. We report here an approach for direct electrical detection of enzymatically catalyzed DNA synthesis by induced surface charge perturbation. We discovered that incorporation of a complementary deoxynucleotide (dNTP) into a self-primed single-stranded DNA attached to the surface of a gold electrode evokes an electrode surface charge perturbation. This event can be detected as a transient current by a voltage-clamp amplifier. Based on current understanding of polarizable interfaces, we propose that the electrode detects proton removal from the 3′-hydroxyl group of the DNA molecule during phosphodiester bond formation.
Surveillance in Taiwan Using Molecular Epidemiology for Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae
Authors: Yu Wen-Liang , Winokur Patricia L. , Jones Ronald N. , Sader Hélio S.
Published: April 2006

Objective:

To evaluate intrahospital and interhospital clonal dissemination of extended-spectrum beta-lactamase (ESBL)-producing strains of Klebsiella pneumoniae.

Setting:

Eight tertiary-care university hospitals and 16 regional hospitals in Taiwan.

Methods:

Two hundred eleven confirmed ESBL-producing isolates of K. pneumoniae were collected from January 1998 to June 2000. The isolates were characterized by various typing methods, including antibiogram (9 antimicrobial agents), computer-based ribotyping, pulsed-field gel electrophoresis (PFGE), and isoelectric focusing of beta-lactamase.

Results:

Ribotyping identified 70 distinct ribogroups among 200 isolates evaluated. Forty-three of these ribogroups were unique. Eleven ribogroups, comprising 115 isolates, were detected in more than one hospital (interhospital dissemination), whereas 16 groups (42 isolates) were detected in more than one patient within a hospital (intrahospital dissemination). The combination of ribotyping and PFGE identified two large epidemic clones, which were called 691.5/PFGE-G and 595.7/PFGE-A. These epidemic clones were detected mainly in the hospitals located in the northern and central regions of Taiwan. However, variation of the profiles of antibiograms and isoelectric focusing was apparent within each clone. In addition, isolates with the same isoelectric focusing profile (isoelectric points 7.9, 8.2, and 8.4) and antibiogram (resistance to 9 compounds evaluated) were present among different molecular-typed clones.

Conclusions:

Our results showed that clonal dissemination (both interhospital and intrahospital dissemination) is occurring in several regions of Taiwan. Rapid computer-based ribotyping associated with PFGE demonstrated multiple epidemic clones of ESBL-producing K. pneumoniae in Taiwan. The combination of phenotypic and molecular methods has proved useful to characterize these epidemic clones.
Control of Enterobacteriaceae Producing Extended-Spectrum Beta-Lactamase in Intensive Care Units: Rectal Screening May Not Be Needed in Non-Epidemic Situations
Authors: Thouverez Michelle , Talon Daniel , Bertrand Xavier
Published: April 2006

Objective:

To evaluate the usefulness of screening cultures in the control of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in intensive care units (ICUs).

Design:

A 4-year retrospective study.

Setting:

Two adult ICUs of a university-affiliated public hospital in France.

Results:

A total of 7,777 specimens were analyzed and 28 (0.97%) of 2,883 screened patients had a positive result on a screening test, among the 3,678 admitted patients. Thirteen of these 28 patients were only carriers; 4 were carriers and then were colonized or infected 2, 2, 3, and 8 days later, respectively; and 11 were colonized or infected before a screening test was positive. Cluster analysis showed that the occurrence of ESBL-producing Enterobacteriaceae cross-transmission within both ICUs was limited to 9 cases. Thus, most cases (19 of 28) were probably imported. Surveillance cultures failed to detect 9 of the 19 cases.

Conclusion:

The low prevalence of ESBL-producing Enterobacteriaceae carriers on admission (0.45%) and the relative ineffectiveness of our screening test to detect imported cases suggest that systematic detection of ESBL-producing Enterobacteriaceae in ICU patients is not cost-effective and that the use of clinical cultures may be sufficient to control ESBL-producing Enterobacteriaceae in non-epidemic situations.
Rapidly Rising Prevalence of Nosocomial Multidrug-Resistant, Gram-Negative Bacilli: A 9-Year Surveillance Study
Authors: D'Agata Erika M. C.
Published: April 2006

Objective:

To examine and quantify the temporal trends of nosocomial multidrug-resistant, gram-negative bacilli.

Design:

A 9-year surveillance study was conducted. Multidrug resistance was defined as resistance to 3 or more antimicrobial classes.

Setting:

Tertiary-care institution.

Results:

From 1994 to 2002, multidrug-resistant, gram-negative bacilli increased from 1% to 16% for multidrug-resistant Pseudomonas aeruginosa, 4% to 13% for multidrug-resistant Enterobacter species, 0.5% to 17% for multidrug-resistant Klebsiella species, 0% to 9% for multidrug-resistant Proteus species, and 0.2% to 4% for multidrug-resistant Escherichia coli (P ≤ .05). The most common pattern of multidrug resistance was co-resistance to quinolones, third-generation cephalosporins, and aminoglycosides.

Conclusion:

The rapid rise of multidrug-resistant, gram-negative bacilli may warrant infection control programs to include these pathogens in strategies aimed at limiting the emergence and spread of antimicrobial-resistant pathogens.
Multidrug-Resistant Pseudomonas aeruginosa Cholangitis After Endoscopic Retrograde Cholangiopancreatography: Failure of Routine Endoscope Cultures to Prevent an Outbreak
Authors: Fraser Thomas G. , Reiner Sandra , Malczynski Michael , Yarnold Paul R. , Warren John , Noskin Gary A.
Published: April 2006

Background:

Nosocomial infections due to medical devices are of increasing concern to infection control practitioners. Attempts to prevent such infections have included surveillance cultures of endoscopes and bronchoscopes. In July 2002, the infectious disease consultation service was asked to see three patients with sepsis due to multidrug-resistant Pseudomonas aeruginosa after endoscopic retrograde cholangiopancreatography (ERCP).

Objective:

To describe an outbreak of multidrug-resistant P. aeruginosa sepsis after ERCP at an institution that performs routine surveillance cultures of endoscopes.

Design:

A traditional outbreak investigation supplemented by pulsed-field gel electrophoresis (PFGE) was undertaken, including a case-control analysis based on the hypothesis that all infected individuals had their ERCP performed with the same endoscope.

Setting:

A tertiary-care academic medical center.

Results:

The case-control analysis confirmed the hypothesis that undergoing ERCP with the implicated endoscope was associated with a culture positive for Pseudomonas (P = .01). The available strains were identical by PFGE. This outbreak occurred despite a negative surveillance culture of the implicated endoscope 1 month earlier.

Conclusions:

Infectious morbidity can occur after endoscopy despite negative surveillance cultures. The practice of routine endoscope cultures does not prevent device-related infectious morbidity.
Intrinsic Klebsiella pneumoniae Contamination of Liquid Germicidal Hand Soap Containing Chlorhexidine
Authors: Brooks Steven E. , Walczak Mary A. , Malcolm Sharon , Hameed Rizwanullah
Published: April 2006

We describe intrinsic contamination with Klebsiella pneumoniae occurring during the manufacture of germicidal hand soap, labeled as containing 2% chlorhexidine, used throughout a 350-bed community medical center. A 3-year retrospective study failed to find evidence of increased incidence of clinical isolates of this strain.
Molecular Typing of Agrobacterium Species Isolates From Catheter-Related Bloodstream Infections
Authors: Giammanco Giovanni M. , Pignato Sarina , Santangelo Carmelita , Grimont Patrick A. D. , Grimont Francine , Giammanco Giuseppe
Published: April 2006

Agrobacterium isolates from intravenous catheters of three hospitalized patients were initially identified as A. tumefaciens, but inability to produce 3-ketolactose revealed that two of them were A. vitis. However, rDNA analysis correlated all of the isolates to A. tumefaciens. Pulsed-field gel electrophoresis analysis ascertained the nosocomial transmission of the infection.
Policies and Practices for Improving Influenza Immunization Rates Among Healthcare Workers
Authors: Goldstein Adam O. , Kincade Jean E. , Gamble George , Bearman Rachel S.
Published: April 2006

Objective:

To determine the attitudes, policies, and barriers for requiring annual versus voluntary influenza vaccinations for the staff of healthcare institutions in North Carolina.

Methods:

Five different types of institutions serving at-risk elderly populations throughout North Carolina were chosen for study, including hospitals, home health agencies, nursing homes, dialysis centers, and assisted living facilities. Infection control managers completed a 45-question telephone survey on policies for annual influenza vaccinations for employees, incentives to encourage immunizations, support for mandatory influenza vaccinations for workers, barriers to employee vaccinations, and support for a state law to mandate influenza immunizations for employees with patient care contact.

Results:

Of 312 institutions, 268 (86%) participated in the study. Only 38% of institutions reported having formal written employee influenza vaccination policies, and only 2% actually mandated annual employee vaccinations. Reported barriers to increasing healthcare worker annual influenza vaccinations included “fear of side effects” and “perceived ineffectiveness of the flu vaccine.” Almost half of the respondents would support mandating influenza vaccinations for all healthcare workers with direct patient contact.

Conclusion:

A state-wide survey of the receptivity, policies, and implications of mandated employee influenza vaccinations among healthcare institutions serving the elderly in North Carolina found written policies uncommon and most of the mechanisms used to increase vaccinations voluntary. Efforts should be tailored to individuals, institutions, and healthcare systems to dramatically increase employee immunization rates.
Use Of A Mobile Cart Influenza Program For Vaccination Of Hospital Employees
Authors: Sartor Catherine , Tissot-Dupont Herve , Zandotti Christine , Martin Francoise , Roques Pierre , Drancourt Michel
Published: April 2006

Objective:

Rates of annual influenza vaccination of healthcare workers (HCWs) remained low in our university hospital. This study was conducted to evaluate the impact of a mobile cart influenza vaccination program on HCW vaccination.

Methods:

From 2000 to 2002, the employee health service continued its annual influenza vaccination program and the mobile cart program was implemented throughout the institution. This program offered influenza vaccination to all employees directly on the units. Each employee completed a questionnaire. Vaccination rates were analyzed using the Mantel–Haenszel test.

Results:

The program proposed vaccination to 50% to 56% of the employees. Among the nonvaccinated employees, 52% to 53% agreed to be vaccinated. The compliance with vaccination varied from 61% to 77% among physicians and medical students and from 38% to 55% among nurses and other employees. Vaccination of the chief or associate professor of the unit was associated with a higher vaccination rate of the medical staff (P < .01). Altogether, the vaccination program led to an increase in influenza vaccination among employees from 6% in 1998 and 7% in 1999 before the mobile cart program to 32% in 2000, 35% in 2001, and 32% in 2002 (P < .001).

Conclusions:

The mobile cart program was associated with a significantly increased vaccination acceptance. Our study was able to identify HCW groups for which the mobile cart was effective and highlight the role of the unit head in its success.
Preventing Nosocomial Influenza by Improving the Vaccine Acceptance Rate of Clinicians
Authors: Salgado Cassandra D. , Giannetta Eve T. , Hayden Frederick G. , Farr Barry M.
Published: April 2006

Objectives:

To assess the effects of interventions to prevent transmission of influenza and to increase employee compliance with influenza vaccination.

Design:

The change in the proportion of hospitalized patients with laboratory-confirmed nosocomial influenza was observed over time and assessed using chi-square for trend analysis. The association between nosocomial influenza in patients and healthcare worker (HCW) compliance with vaccine was assessed by logistic regression.

Setting:

A 600-bed, tertiary-care academic hospital.

Methods:

After an outbreak of influenza A at this hospital in 1988, a mobile cart program was instituted with increased efforts to motivate employees to be vaccinated and furloughed when ill as well as new measures to prevent nosocomial spread.

Results:

HCW vaccination rates increased from 4% in 1987–1988 to 67% in 1999–2000 (P < .0001). Proportions of nosocomially acquired influenza cases among employees or patients both declined significantly (P < .0001). Logistic regression analysis revealed a significant inverse association between HCW compliance with vaccination and the rate of nosocomial influenza among patients (P < .001).

Conclusion:

A mobile cart vaccination program and an increased emphasis on HCWs to receive the vaccine were associated with a significant increase in vaccine acceptance and a significant decrease in the rate of nosocomial influenza among patients.
Influenza Vaccination: A Collaborative Effort to Improve the Health of the Community
Authors: Parry Michael F. , Grant Brenda , Iton Anthony , Parry Patricia D. , Baranowsky Diane
Published: April 2006

Background:

The need to improve influenza vaccination delivery in our community became painfully clear during the winter of 1997–1998 when high rates of respiratory illness led to congestion in the emergency department and a critical shortage of hospital beds. In response, the local hospital and the Department of Health launched a collaborative program to increase influenza vaccine coverage in the community.

Methods:

The partnership was designed to increase the number of citizens receiving influenza vaccine and to moderate the severity of lower respiratory tract illness during the winter season. A variety of methods were used to increase public awareness, enhance vaccine delivery, and create a relatively seamless service for the community.

Results:

During three seasons, influenza vaccination rates increased by a relative 150%. This represented immunization of 16% of the entire community and more than 75% of residents older than 65 years. Hospital employee vaccination rates also rose from 34% to 58%. When compared with other hospitals in the county, the campaign reduced the average number of annual visits to the emergency department for all respiratory diagnoses by 34% and exacerbations of chronic obstructive pulmonary disease by 46%.

Conclusions:

This influenza vaccination program illustrates the potential for synergy that exists between local departments of health and community hospitals in successfully increasing vaccine delivery to the community. Furthermore, it also suggests that such efforts can be successful in reducing use of the emergency department, resulting in a positive impact on the health of the community.
Characteristics of Long-Term–Care Facility Residents Associated With Receipt of Influenza and Pneumococcal Vaccinations
Authors: Bardenheier Barbara , Shefer Abigail , McKibben Linda , Roberts Henry , Bratzler Dale
Published: April 2006

Background:

Studies have found residency in long-term–care facilities (LTCFs) a risk factor for influenza and pneumonia and have demonstrated that vaccinations against these diseases reduce the risk of disease. However, rates are below Healthy People 2010 goals of 90% for LTCFs. During 1999–2002, a multi-state demonstration project was conducted in LTCFs to implement standing orders programs for immunizations.

Objective:

Identify nursing home resident–specific characteristics associated with vaccination coverage at baseline.

Methods:

Facility-level data were collected from self-reported surveys of selected nursing homes in 14 states and from the On-line Survey and Certification Reporting System. Resident-level data, including demographics and physical functioning, were obtained from the Centers for Medicare & Medicaid Services' Minimum Data Set; 2000–2001 vaccination status was obtained by chart review. Influenza vaccination status reflected a single season, whereas pneumococcal vaccination status reflected vaccination in the past. Multilevel analysis was used to control for facility-level variation.

Results:

Of 22,188 residents sampled in 249 LTCFs, complete data were obtained for 20,516 (92%). The average coverage for immunizations was 58.5% ± 0.7% for influenza and 34.6% ± 0.3% for pneumococcal. On bivariate analyses, residents with cognitive, psychiatric, or neurologic problems were more likely to be vaccinated; those with accidental injuries, unstable conditions, or cancer were less likely to receive either vaccine. On multilevel analysis, the strongest resident characteristics associated with receipt of immunizations, controlling facility variation, were cognitive deficits and psychiatric illness.

Conclusion:

The variation in baseline vaccination coverage associated with LTCF resident characteristics supports the need for strategies to increase vaccination coverage in LTCFs.
Adverse Effects of Amantadine and Oseltamivir Used During Respiratory Outbreaks in a Center for Developmentally Disabled Adults
Authors: McGeer Allison J. , Lee Wayne , Loeb Mark , Simor Andrew E. , McArthur Margaret , Green Karen , Benjamin Jonathan Hayfron , Gardner Charles
Published: April 2006

Background And Objectives:

Antiviral prophylaxis is recommended for the control of institutional influenza A outbreaks. In long-term–care institutions other than nursing homes, neither the seriousness of influenza nor the risks and benefits of antiviral prophylaxis is clearly understood. We studied the severity of illness due to influenza among adults residing in a center for the developmentally disabled and assessed adverse reactions to amantadine and oseltamivir prophylaxis.

Methods:

Data were collected from the charts of consenting residents. Complications of upper respiratory tract illness were recorded. Potential adverse events were documented during amantadine and oseltamivir therapy, and during a baseline period with neither medication.

Results:

The median age of the 287 participants was 46.4 years. Only 15 (5%) were older than 65 years, and 69 (24%) had chronic underlying medical illness placing them at high risk for influenza. Of the 122 residents with an upper respiratory tract infection, 16 (13%) developed pneumonia, 12 (9.8%) were hospitalized, and 5 (4%) died. Twenty-eight (25%) of 112 residents had an adverse neurologic event while receiving amantadine prophylaxis, compared with 3 (2.7%) receiving no antiviral medication and 5 (4.5%) receiving oseltamivir (P < .001). Sixteen percent of the residents discontinued amantadine due to adverse events; in contrast, adverse events were identified in 2.9% of the residents prescribed oseltamivir, and none discontinued therapy.

Conclusions:

Viral respiratory tract infections are associated with a high risk of complications in this population. The rate of adverse neurologic events associated with amantadine was significantly higher than that associated with oseltamivir.
Concurrent Summer Influenza and Pertussis Outbreaks in a Nursing Home in Sydney, Australia
Authors: Ferson Mark J. , Morgan Keira , Robertson Peter W. , Hampson Alan W. , Carter Ian , Rawlinson William D.
Published: April 2006

Objective:

To report on the investigation of a summer outbreak of acute respiratory illness among residents of a Sydney nursing home.

Design:

An epidemiologic and microbiological investigation of the resident cohort at the time of the outbreak and medical record review 5 months later.

Setting:

A nursing home located in Sydney, Australia, during February to July 1999.

Patients:

The cohort of residents present in the nursing home at the time of the outbreak.

Interventions:

Public health interventions included recommendations regarding hygiene, cohorting of residents and staff, closure to further admissions, and prompt reporting of illness; and virologic and serologic studies of residents.

Results:

Of the 69 residents (mean age, 85.1 years), 35 fulfilled the case definition of acute respiratory illness. Influenza A infection was confirmed in 19 residents, and phylogenetic analysis of the resulting isolate, designated H3N2 A/Sydney/203/99, showed that it differed from strains isolated in eastern Australia during the same period. Serologic evidence of Bordetella infection was also found in 10 residents; however, stratified epidemiologic analysis pointed to influenza A as the cause of illness.

Conclusions:

The investigation revealed an unusual summer outbreak of influenza A concurrent with subclinical pertussis infection. Surveillance of acute respiratory illness in nursing homes throughout the year, rather than solely during epidemic periods, in combination with appropriate public health laboratory support, would allow initiation of a timely public health response to outbreaks of acute respiratory illness in this setting.
Persistent Acinetobacter baumannii? Look Inside Your Medical Equipment
Authors: Bernards A. T. , Harinck H. I. J. , Dijkshoorn L. , van der Reijden T. J. K. , van den Broek P. J.
Published: April 2006

Two outbreaks of multidrug-resistant Acinetobacter baumannii occurred in our hospital. The outbreak strains were eventually isolated from respiratory ventilators, an apparatus used to cool or warm patients, and four continuous veno-venous hemofiltration machines. Removing dust from the machines and replacing all dust filters brought the outbreaks to an end.
Epidemiologic Study of Nosocomial Urinary Tract Infections in Saudi Military Hospitals
Authors: Al-Helali Nabil S. , Al-Asmary Saeed M. , Abdel-Fattah Moataz M. , Al-Jabban Tawfiq M. , Al-Bamri Abdel-Latif M.
Published: April 2006

A case-control study of patients with and without confirmed UTI was performed to identify risk factors for nosocomial UTI. Duration of hospitalization, unit of admission, history of diabetes mellitus or debilitating diseases, and duration and number of urinary catheters were independently associated with increased risk of nosocomial UTIs.
Mycobacterium simiae Outbreak Associated With a Hospital Water Supply
Authors: Conger Nicholas G. , O'Connell Robert J. , Laurel Valerie L. , Olivier Kenneth N. , Graviss Edward A. , Williams-Bouyer Natalie , Zhang Yansheng , Brown-Elliott Barbara A. , Wallace Richard J.
Published: April 2006

Objective:

Mycobacterium simiae is found primarily in the southwestern United States, Israel, and Cuba, with tap water as its suspected reservoir. Our institution saw an increase in M. simiae isolates in 2001. An investigation into possible contaminated water sources was undertaken.

Design:

Environmental cultures were performed from water taps in the microbiology laboratory, patient rooms, points in the flow of water to the hospital, and patients' homes. Patient and environmental M. simiae were compared by PFGE.

Setting:

Military treatment facility in San Antonio, Texas.

Patients:

All patients with cultures positive for M. simiae between January 2001 and April 2002. Medical records were reviewed.

Results:

M. simiae was recovered from water samples from the hospital, patients' home showers, and a well supplying the hospital. A single PFGE clone was predominant among water isolates (9 of 10) and available patient isolates (14 of 19). There was an association between exposure to hospital water and pulmonary samples positive for the clonal M. simiae strain (P = .0018). Only 3 of 22 culture-positive patients met criteria for M. simiae pulmonary disease. Of them, two had indistinguishable M. simiae strains from tap water to which they were routinely exposed.

Conclusions:

This represents an outbreak of M. simiae colonization with one nosocomial infection. It is only the second time that M. simiae has been recovered from hospital tap water and its first presentation in municipal water. This study raises issues about the need and feasibility of eliminating or avoiding exposure to M. simiae from tap water.
Environmental Cultures and Hospital-Acquired Legionnaires' Disease: A 5-Year Prospective Study in 20 Hospitals in Catalonia, Spain
Authors: Sabrià Miquel , Mòdol Josep M. , Garcia-Nuñez Marian , Reynaga Esteban , Pedro-Botet Maria L. , Sopena Nieves , Rey-Joly C.
Published: April 2006

Objective:

To determine whether environmental cultures for Legionella increase the index of suspicion for legionnaires' disease (LD).

Design:

Five-year prospective study.

Setting:

Twenty hospitals in Catalonia, Spain.

Methods:

From 1994 to 1996, the potable water systems of 20 hospitals in Catalonia were tested for Legionella, Cases of hospital-acquired LD and availability of an “in-house” Legionella test in the previous 4 years were assessed. After the hospitals were informed of the results of their water cultures, a prospective 5-year-study was conducted focusing on the detection of new cases of nosocomial legionellosis and the availability and use of Legionella testing.

Results:

Before environmental cultures were started, only one hospital had conducted active surveillance of hospital-acquired pneumonia and used Legionella tests including Legionella urinary antigen in all pneumonia cases. Only one other hospital had used the latter test at all. In six hospitals, Legionella tests had been completely unavailable. Cases of nosocomial LD had been diagnosed in the previous 4 years in only two hospitals. During prospective surveillance, 12 hospitals (60%) used Legionella urinary antigen testing in house and 11 (55%) found cases of nosocomial legionellosis, representing 64.7% (11 of 17) of those with positive water cultures. Hospitals with negative water cultures did not find nosocomial LD.

Conclusions:

The environmental study increased the index of suspicion for nosocomial LD. The number of cases of nosocomial LD increased significantly during the prospective follow-up period, and most hospitals began using the Legionella urinary antigen test in their laboratories.
Tuberculosis Prevention and Control in Long-Term–Care Facilities for Older Adults
Authors: Thrupp Lauri , Bradley Suzanne , Smith Philip , Simor Andrew , Gantz Nelson , Crossley Kent , Loeb Mark , Strausbaugh Larry , Nicolle Lindsay ,   SHEA Long-Term-Care Committee
Published: April 2006

In the United States, older adults comprise 22% of cases of tuberculous disease but only 12% of the population. Most cases of tuberculosis (TB) occur in community dwellers, but attack rates are highest among frail residents of long-term–care facilities. The detection and treatment of latent TB infection and TB disease can pose special challenges in older adults. Rapid recognition of possible disease, diagnosis, and implementation of airborne precautions are essential to prevent spread. It is the intent of this evidence-based guideline to assist healthcare providers in the prevention and control of TB, specifically in skilled nursing facilities for the elderly.
Limitations of Forehead Infrared Body Temperature Detection for Fever Screening for Severe Acute Respiratory Syndrome
Authors: Liu Chuan-Chuan , Chang Ray-E , Chang Wen-Cheng
Published: April 2006

We investigated alternative measurement methodology for infrared body thermometry to increase accuracy for outdoor fever screening during the 2003 SARS epidemic. Our results indicate that the auditory meatus temperature is a superior alternative compared with the forehead body surface temperature due to its close approximation to the tympanic temperature.
Factors Affecting Perceived Risk of Contracting Severe Acute Respiratory Syndrome Among Academic Physicians
Authors: Grace Sherry L. , Hershenfield Karen , Robertson Emma , Stewart Donna E.
Published: April 2006

SARS disproportionately affects healthcare providers. A physician survey was administered within three hospitals providing care to SARS patients. Knowing a colleague who contracted SARS and previous occupational exposure to infectious agents were significantly predictive of greater perceived risk, whereas perceived effectiveness of precautions and provision of direct care were not.
Dynamics of Bacterial Hand Contamination During Routine Neonatal Care
Authors: Pessoa-Silva Carmem Lúcia , Dharan Sasi , Hugonnet Stéphane , Touveneau Sylvie , Posfay-Barbe Klara , Pfister Riccardo , Pittet Didier
Published: April 2006

Objective:

To evaluate the dynamics of bacterial contamination of healthcare workers' (HCWs) hands during neonatal care.

Setting:

The 20-bed neonatal unit of a large acute care teaching hospital in Geneva, Switzerland.

Methods:

Structured observation sessions were conducted. A sequence of care began when the HCW performed hand hygiene and ended when the activity changed or hand hygiene was performed again. Alcohol-based handrub was the standard procedure for hand hygiene. An imprint of the five fingertips of the dominant hand was obtained before and after hand hygiene and at the end of a sequence of care. Regression methods were used to model the final bacterial count according to the type and duration of care and the use of gloves.

Results:

One hundred forty-nine sequences of care were observed. Commensal skin flora comprised 72.4% of all culture-positive specimens (n = 360). Other microorganisms identified were Enterobacteriaceae (n = 55, 13.8%);Staphylococcus aureus(n = 10, 2.5%); and fungi (n = 7,1.8%). Skin contact, respiratory care, and diaper change were independently associated with an increased bacterial count; the use of gloves did not fully protect HCWs' hands from bacterial contamination.

Conclusions:

These data confirm that hands become progressively contaminated with commensal flora and potential pathogens during neonatal care, and identify activities at higher risk for hand contamination. They also reinforce the need for hand hygiene after a sequence of care, before starting a different task, and after glove removal.