bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation of sensory neuron mechanotransduction by PKC- and nerve growth factor-dependent pathways
Authors: Di Castro Amalia , Drew Liam J. , Wood John N. , Cesare Paolo
Published: March 2006

Many sensations of pain are evoked by mechanical stimuli, and in inflammatory conditions, sensitivity to such stimuli is commonly increased. Here we used cultured sensory neurons as a model of the peripheral terminal to investigate the effects of inflammatory signaling pathways on mechanosensitive ion channels. Activation of two of these pathways enhanced transduction in a major population of nociceptors. The proinflammatory neurotrophin nerve growth factor caused an up-regulation of mechanically activated currents via a transcriptional mechanism. Activators of PKC, given
in vitro
and
in vivo
, also caused an increase in mechanically activated membrane current and behavioral sensitization to mechanical stimulation, respectively. The effect of activating PKC was inhibited by tetanus toxin, suggesting that insertion of new channels into the cell membrane is involved in sensitization. These results reveal previously undescribed mechanisms by which PKC and nerve growth factor synergistically enhance the response of nociceptors to mechanical stimuli, suggesting possible targets for pain treatment.
Social exploitation of hexamerin: RNAi reveals a major caste-regulatory factor in termites
Authors: Zhou Xuguo , Oi Faith M. , Scharf Michael E.
Published: March 2006

Lower termites express a unique form of eusocial polyphenism in that totipotent workers can differentiate into either soldier or reproductive caste phenotypes. In this initial effort using RNA interference in termites, we found that two hexamerin genes,
Hex-1
and
Hex-2
, participate in the regulation of caste polyphenism. Our methodology involved a dual gene-silencing approach that used a single short-interfering RNA fragment to silence the two homologous hexamerin genes. We performed validation studies that evaluated effects on nontarget housekeeping genes, silencing of a nonhousekeeping control gene, and effects at the protein level. We found that the two hexamerin proteins, which are inducible by the morphogenetic juvenile hormone and which constitute a significant proportion of total termite protein, suppress juvenile-hormone-dependent worker differentiation to the soldier caste phenotype. This mechanism allows termite colonies to retain high proportions of altruistic worker caste members, thus apparently enhancing colony-inclusive fitness. These findings demonstrate a unique status quo regulatory mechanism for termite worker caste retention and provide an example of previously undescribed preadult developmental/caste-regulatory genes from any social insect.
Differential recognition of plant cell walls by microbial xylan-specific carbohydrate-binding modules
Authors: McCartney Lesley , Blake Anthony W. , Flint James , Bolam David N. , Boraston Alisdair B. , Gilbert Harry J. , Knox J. Paul
Published: March 2006

Glycoside hydrolases that degrade plant cell walls have complex molecular architectures in which one or more catalytic modules are appended to noncatalytic carbohydrate-binding modules (CBMs). CBMs promote binding to polysaccharides and potentiate enzymic hydrolysis. Although there are diverse sequence-based families of xylan-binding CBMs, these modules, in general, recognize both decorated and unsubstituted forms of the target polysaccharide, and thus the evolutionary rationale for this diversity is unclear. Using immunohistochemistry to interrogate the specificity of six xylan-binding CBMs for their target polysaccharides in cell walls has revealed considerable differences in the recognition of plant materials between these protein modules. Family 2b and 15 CBMs bind to xylan in secondary cell walls in a range of dicotyledon species, whereas family 4, 6, and 22 CBMs display a more limited capability to bind to secondary cell walls. A family 35 CBM, which displays more restricted ligand specificity against purified xylans than the other five protein modules, reveals a highly distinctive binding pattern to plant material including the recognition of primary cell walls of certain dicotyledons, a feature shared with CBM15. Differences in the specificity of the CBMs toward walls of wheat grain and maize coleoptiles were also evident. The variation in CBM specificity for ligands located in plant cell walls provides a biological rationale for the repertoire of structurally distinct xylan-binding CBMs present in nature, and points to the utility of these modules in probing the molecular architecture of cell walls.
The molecular elasticity of the insect flight muscle proteins projectin and kettin
Authors: Bullard Belinda , Garcia Tzintzuni , Benes Vladimir , Leake Mark C. , Linke Wolfgang A. , Oberhauser Andres F.
Published: March 2006

Projectin and kettin are titin-like proteins mainly responsible for the high passive stiffness of insect indirect flight muscles, which is needed to generate oscillatory work during flight. Here we report the mechanical properties of kettin and projectin by single-molecule force spectroscopy. Force–extension and force-clamp curves obtained from
Lethocerus
projectin and
Drosophila
recombinant projectin or kettin fragments revealed that fibronectin type III domains in projectin are mechanically weaker (unfolding force, F
u
≈ 50–150 pN) than Ig-domains (F
u
≈ 150–250 pN). Among Ig domains in Sls/kettin, the domains near the N terminus are less stable than those near the C terminus. Projectin domains refolded very fast [85% at 15 s
−1
(25°C)] and even under high forces (15–30 pN). Temperature affected the unfolding forces with a Q
10
of 1.3, whereas the refolding speed had a Q
10
of 2–3, probably reflecting the cooperative nature of the folding mechanism. High bending rigidities of projectin and kettin indicated that straightening the proteins requires low forces. Our results suggest that titin-like proteins in indirect flight muscles could function according to a folding-based-spring mechanism.
Structural basis for mammalian vitamin B
12
transport by transcobalamin
Authors: Wuerges Jochen , Garau Gianpiero , Geremia Silvano , Fedosov Sergey N. , Petersen Torben E. , Randaccio Lucio
Published: March 2006

Cobalamin (Cbl, vitamin B
12
) serves for two essential cofactors in mammals. The pathway for its intestinal absorption, plasma transport, and cellular uptake uses cell surface receptors and three Cbl-transporting proteins, haptocorrin, intrinsic factor, and transcobalamin (TC). We present the structure determination of a member of the mammalian Cbl-transporter family. The crystal structures of recombinant human and bovine holo-TCs reveal a two-domain architecture, with an N-terminal α
6
-α
6
barrel and a smaller C-terminal domain. One Cbl molecule in base-on conformation is buried inside the domain interface. Structural data combined with previous binding assays indicate a domain motion in the first step of Cbl binding. In a second step, the weakly coordinated ligand H
2
O at the upper axial side of added H
2
O-Cbl is displaced by a histidine residue of the α
6
-α
6
barrel. Analysis of amino acid conservation on TC’s surface in orthologous proteins suggests the location of the TC-receptor-recognition site in an extended region on the α
6
-α
6
barrel. The TC structure allows for the mapping of sites of amino acid variation due to polymorphisms of the human TC gene. Structural information is used to predict the overall fold of haptocorrin and intrinsic factor and permits a rational approach to the design of new Cbl-based bioconjugates for diagnostic or therapeutic drug delivery.
High-efficiency biolistic transformation of
Chlamydomonas
mitochondria can be used to insert mutations in complex I genes
Authors: Remacle Claire , Cardol Pierre , Coosemans Nadine , Gaisne Mauricette , Bonnefoy Nathalie
Published: March 2006

Mitochondrial transformation of
Chlamydomonas reinhardtii
has been optimized by using a particle-gun device and cloned mitochondrial DNA or PCR fragments. A respiratory-deficient strain lacking a 1.2-kb mitochondrial DNA region including the left telomere and part of the
cob
gene could be rescued as well as a double-frameshift mutant in the mitochondrial
cox1
and
nd1
genes. High transformation efficiency has been achieved (100–250 transformants per microgram of DNA), the best results being obtained with linearized plasmid DNA. Molecular analysis of the transformants suggests that the right telomere sequence can be copied to reconstruct the left telomere by recombination. In addition, both nondeleterious and deleterious mutations could be introduced. Myxothiazol-resistant transformants have been created by introducing a nucleotide substitution into the
cob
gene. Similarly, an in-frame deletion of 23 codons has been created in the
nd4
mitochondrial gene of both the deleted and frameshift recipient strains. These 23 codons are believed to encode the first transmembrane segment of the ND4 protein. This Δ
nd4
mutation causes a misassembly of complex I, with the accumulation of a subcomplex that is 250-kDa smaller than the wild-type complex I. The availability of efficient mitochondrial transformation in
Chlamydomonas
provides an invaluable tool for the study of mitochondrial biogenesis and, more specifically, for site-directed mutagenesis of mitochondrially encoded subunits of complex I, of special interest because the yeast
Saccharomyces cerevisiae
, whose mitochondrial genome can be manipulated virtually at will, is lacking complex I.
Role of the lytic repressor in prophage induction of phage λ as analyzed by a module-replacement approach
Authors: Atsumi Shota , Little John W.
Published: March 2006

Using a module exchange approach, we have tested a long-standing model for the role of Cro repressor in λ prophage induction. This epigenetic switch from lysogeny to the lytic state occurs on activation of the host SOS system, which leads to specific cleavage of CI repressor. It has been proposed that Cro repressor, which operates during lytic growth and which we shall term the lytic repressor, is crucial to prophage induction. In this view, Cro binds to the
O
R
3 operator, thereby repressing the
cI
gene and making the switch irreversible. Here we tested this model by replacing λ Cro with a dimeric form of Lac repressor and adding several
lac
operators. This approach allowed us to regulate the function of the lytic repressor at will and to prevent it from repressing
cI
, because
lac
repressor could not repress
P
RM
in our constructs. Repression of
cI
by the lytic repressor was not required for prophage induction to occur. However, our evidence suggests that this binding can make induction more efficient, particularly at intermediate levels of DNA damage that otherwise cause induction of only a fraction of the population. These results indicate that this strategy of module exchange will have broad applications for analysis of gene regulatory circuits.
S-nitrosylation and permeation through connexin 43 hemichannels in astrocytes: Induction by oxidant stress and reversal by reducing agents
Authors: Retamal Mauricio A. , Cortés Constanza J. , Reuss Luis , Bennett Michael V. L. , Sáez Juan C.
Published: March 2006

Marked increase in cell permeability ascribed to open connexin (Cx)43 hemichannels is induced by metabolic inhibition (MI) of cortical astrocytes in culture, but the molecular mechanisms are not established. Dephosphorylation and/or oxidation of Cx43 hemichannels was proposed as a potential mechanism to increase their open probability. We now demonstrate that MI increases the number of hemichannels on the cell surface assayed by biotinylation and Western blot, and that this change is followed by increased dephosphorylation and S-nitrosylation. The increase in rate of dye uptake caused by MI is comparable to the increase in surface expression; thus, open probability and permeation per hemichannel may be unchanged. Reducing agents did not affect dephosphorylation of Cx43 hemichannels but reduced dye uptake and S-nitrosylation. Uptake was also reduced by elevated intracellular but not extracellular levels of reduced glutathione. Moreover, nitric oxide donors induced dye uptake and nitrosylation of surface Cx43 but did not affect its abundance or phosphorylation. Thus, permeability per channel is increased, presumably because of increase in open probability. We propose that increased dye uptake induced by MI is mediated by an increased number of Cx43 hemichannels in the surface and is associated with multiple molecular changes, among which nitrosylation of intracellular Cx43 cysteine residues may be a critical factor.
Indoleacetic acid, a product of transferred DNA, inhibits
vir
gene expression and growth of
Agrobacterium tumefaciens
C58
Authors: Liu Pu , Nester Eugene W.
Published: March 2006

Agrobacterium tumefaciens
induces crown gall tumors by transferring a piece of its tumor-inducing plasmid into plant cells. This transferred DNA encodes the synthesis of indole acetic acid (IAA) and cytokinin, and their overproduction results in tumor formation. The transfer is initiated by a two-component regulatory system, VirA/G recognizing plant signal molecules in the plant rhizosphere and activating a regulon on the tumor-inducing plasmid, which is required for the processing and transfer of DNA and protein. Although a great deal is known about
vir
gene activation, nothing is known about whether or how the
vir
gene regulon is inactivated after plant cell transformation. Presumably, just as a mechanism exists for activating the
vir
gene regulon only when a plant is in the immediate environment, a mechanism should exist for inactivating the same regulon once it has fulfilled its mission to transferred DNA into plant cells. We now show that IAA inactivates
vir
gene expression by competing with the inducing phenolic compound acetosyringone for interaction with VirA. IAA does not inhibit the
vir
genes in cells containing a constitutive sensor
virA
locus, which does not require any signal molecules to become phosphorylated. At higher concentrations, IAA inhibits the growth of
Agrobacterium
and many other plant-associated bacteria but not the growth of bacteria that occupy other ecological niches. These observations provide the missing link in the cycle of
vir
gene activation and inactivation.
Discrete and analogue quantity processing in the parietal lobe: A functional MRI study
Authors: Castelli Fulvia , Glaser Daniel E. , Butterworth Brian
Published: March 2006

The human intraparietal sulcus (IPS) is implicated in processing symbolic number information and possibly in nonsymbolic number information. Specific IPS activity for discrete quantities (numerosities) as compared with continuous, analogue quantity has not been demonstrated. Here we use a stimulus-driven paradigm to distinguish automatic estimation of “how many things” from “how much” and “how long.” The discrete analogue response task (DART) uses the perception of hues which can change either abruptly (discrete, numerous stimuli) or smoothly (analogue, nonnumerous stimuli) in space or in time. Subjects decide whether they saw more green or more blue. A conjunction analysis of spatial and temporal conditions revealed that bilateral IPS was significantly more active during the processing of discrete stimuli than during analogue stimuli, as was a parietal-occipital transition zone. We suggest that processing numerosity is a distinct process from processing analogue quantity, whether extended in space or time, and that an intraparietal network connects objects’ segmentation to the estimation of their numerosity.
Recombination between elongation factor 1α genes from distantly related archaeal lineages
Authors: Inagaki Yuji , Susko Edward , Roger Andrew J.
Published: March 2006

Homologous recombination (HR) and lateral gene transfer are major processes in genome evolution. The combination of the two processes, HR between genes in different species, has been documented but is thought to be restricted to very similar sequences in relatively closely related organisms. Here we report two cases of interspecific HR in the gene encoding the core translational protein translation elongation factor 1α (EF-1α) between distantly related archaeal groups. Maximum-likelihood sliding window analyses indicate that a fragment of the EF-1α gene from the archaeal lineage represented by
Methanopyrus kandleri
was recombined into the orthologous gene in a common ancestor of the Thermococcales. A second recombination event appears to have occurred between the EF-1α gene of the genus
Methanothermobacter
and its ortholog in a common ancestor of the Methanosarcinales, a distantly related euryarchaeal lineage. These findings suggest that HR occurs across a much larger evolutionary distance than generally accepted and affects highly conserved essential “informational” genes. Although difficult to detect by standard whole-gene phylogenetic analyses, interspecific HR in highly conserved genes may occur at an appreciable frequency, potentially confounding deep phylogenetic inference and hypothesis testing.
Detection of Postoperative Surgical-Site Infections: Comparison of Health Plan–Based Surveillance With Hospital-Based Programs
Authors: Sands Kenneth E. , Yokoe Deborah S. , Hooper David C. , Tully John L. , Horan Teresa C. , Gaynes Robert P. , Solomon Steven L. , Platt Richard
Published: March 2006

Background:

Review of health plan administrative data has been shown to be more sensitive than other methods for identifying postdischarge surgical-site infections (SSIs), but there has not been a direct comparison between this method and hospital-based surveillance for all infections, including those diagnosed before discharge. We compared these two methods for identifying SSIs following coronary artery bypass graft (CABG) procedures:.

Methods:

We studied 1,352 CABG procedures performed among members of one health plan from March 1993 through June 1997. Health plan administrative records were reviewed based on claims containing diagnoses or procedures suggestive of infection or outpatient dispensing of antibiotics appropriate for SSI. Hospital-based surveillance information was also reviewed. SSI rates were calculated based on the total events identified by either mechanism.

Results:

Postdischarge information was reviewed for 328 (85%) of 388 procedures. SSIs were confirmed in 167 patients (13% overall risk of confirmed SSI; range, 3% to 14% in the 5 hospitals). The overall sensitivity of hospital-based surveillance was 49.7% (83 of 167), and that of health plan data was 71.8% (120 of 167). There was no significant difference among hospitals in the sensitivity of either surveillance mechanism.

Conclusions:

Surveillance based on health plan data identified more postoperative infections, including those occurring before discharge, than did hospital-based surveillance. Screening administrative data and pharmacy activity may be an important adjunct to SSI surveillance, allowing efficient comparison of hospital-specific rates. Interpretation of differences among hospitals' infection rates requires case mix adjustment and understanding of variations in hospitals' discharge diagnosis coding practices
Standardized Infection Ratios for Three General Surgery Procedures: A Comparison Between Spanish Hospitals and U.S. Centers Participating in the National Nosocomial Infections Surveillance System
Authors: Jodra V. Monge , Rodela A. Robustillo , Martínez F. Martín , Fresneña N. López ,   Quality Control Indicator Working Group
Published: March 2006

Objectives:

To compare Spanish surgical wound infection (SWI) rates for three procedures with those published by the U.S. NNIS System, and to analyze quarterly trends.

Design:

This was a 4-year prospective analysis of SWI using data from a Spanish nosocomial infection surveillance network based on CDC classification criteria. SWI rates were computed as standardized infection ratios (SIRs). Trends for both SWIs and SIRs were evaluated by linear regression.

Setting:

Forty-three Spanish hospitals during 1997 through 2000.

Patients:

Those undergoing cholecystectomy (n = 7,631), appendectomy (n = 5,780), and herniorrhaphy (n = 9,864).

Results:

For cholecystectomy patients, the SWI rate was 4.38% and the SIR was 3.32. Both of these variables showed a slightly rising, although nonsignificant, linear trend during the study period. For appendectomy patients, the SWI rate was 7.94% and the SIR was 2.86. The linear trend was increasing for both, but only the SWI rate attained significance. For herniorrhaphy patients, the SWI rate was 1.77% and the SIR was 1.64. Both of these variables showed a significant descending tendency during the 4 years.

Conclusions:

Because the SIR takes into account the patient risk category, it is the best indicator of the trend shown by the SWI rate over time for a given surgical procedure. According to our comparison of SIRs with reference NNIS System values, SWI rates for cholecystectomy and appendectomy were high. Monitoring of the SIR will provide a basis for the design of infection control measures and the assessment of their effectiveness.
PseudomonasSurgical-Site Infections Linked to a Healthcare Worker With Onychomycosis
Authors: Mermel Leonard A. , McKay Maria , Dempsey Jane , Parenteau Stephen
Published: March 2006

Objective:

To determine the etiology ofPseudomonas aeruginosasurgical-site infections following cardiac surgery.

Setting:

University teaching hospital.

Patients:

Those with wound cultures that grewP. aeruginosaafter cardiac surgery performed from 1999 to 2001.

Methods:

Medical records and operating room (OR) records of patients withP. aeruginosacardiac surgical-site infections from 1999 to 2001 were reviewed. Healthcare workers involved with two or more cases were interviewed and examined. Specimens for environmental cultures were obtained from the ORs and cardiac surgical equipment. Cardiac surgery cases were observed and postoperative care and the cleaning of surgical instruments were investigated. OR air handling system records during the epidemic period were reviewed. Molecular fingerprinting of availableP. aeruginosaisolates from infected patients and a healthcare worker was done.

Results:

There were fiveP. aeruginosacardiac surgical-site infections from January to August 2001, compared with no such infections from 1999 to 2000. All were adult patients. One cardiac surgeon with onychomycosis operated on all five cases. He did not routinely double glove. The involved fingernail grewP. aeruginosa.ThreeP. aeruginosapatient isolates were available for pulsed-field gel electrophoresis; two were identical to the isolate from the involved surgeon's onychomycotic nail. No environmental OR cultures grewP. aeruginosa.The surgeon's culture-positive nail was completely removed. There have been noP. aeruginosasurgical-site infections among cardiac surgery patients since this intervention.

Conclusion:

At least two cases of a cluster ofP. aeruginosasurgical-site infections resulted from colonization of a cardiac surgeon's onychomycotic nail.
A National Survey of Surgical Antibiotic Prophylaxis in Turkey
Authors: Hosoglu Salih , Sunbul Mustafa , Erol Serpil , Altindis Mustafa , Caylan Rahmet , Demirdag Kutbettin , Ucmak Hasan , Mendes Havva , Geyik Mehmet Faruk , Turgut Huseyin , Gundes Sibel , Doyuk Elif Kartal , Aldemir Mustafa , Dokucu Ali ihsan
Published: March 2006

Objective:

To assess the quality of antibiotic prophylaxis for clean and clean-contaminated elective surgical procedures.

Design:

A cross-sectional, country-wide survey.

Setting:

Thirty-six hospitals in 12 cities in Turkey.

Participants:

Four hundred thirty-nine surgeons from 6 different specialties who performed selected procedures of interest.

Methods:

A random sample of surgeons from different hospitals was selected. A standardized data collection form was used to record the type of procedure, the names, doses, timing of the first doses, and duration of antibiotics, important decisive factors, and problems in the management of prophylactic antibiotic use for surgical procedures.

Results:

Fifty-five percent of surgeons addressed completed the survey. For clean-contaminated procedures, 6% of surgeons did not use antibiotic prophylaxis, whereas 88% used more than a single dose. Inappropriate antibiotics were chosen for 32% of procedures. In 39% of procedures, the first dose of antibiotics was not administered during induction of anesthesia. Duration of prophylaxis was longer than 24 hours in 80% and longer than 48 hours in 46% of all procedures. Only 112 surgeons (26%) were using definitely appropriate prophylaxis in all ways. Multivariate analysis revealed that surgeons in university hospitals (OR, 2.353; CI95, 1.426–3.884; P = .001) and general surgeons (OR, 4.986; CI95, 2.890–8.604; P < .001) used antibiotic prophylaxis more appropriately. Patients not covered by health insurance (OR, 0.417; CI95, 0.225–0.772; P < .001) were associated with inappropriate prophylaxis.

Conclusion:

Given the high frequency of antibiotics prescribed for surgical prophylaxis in Turkey, adherence to surgical prophylaxis guidelines is urgently needed.
Antimicrobial Activity of Glucoprotamin: A Clinical Study of a New Disinfectant for Instruments
Authors: Widmer Andreas F. , Frei Reno
Published: March 2006

Objective:

To determine the in vitro efficacy of glucoprotamin for the disinfection of instruments.

Design:

Prospective observational study.

Setting:

University women's hospital.

Methods:

Instruments were immersed in saline solution after use, and glucoprotamin was added to a concentration of 1.5% before soaking for 60 minutes. Biocidal activity was determined by the difference in colony-forming units (CFU) on instruments before and after disinfection.

Results:

One hundred thirty-seven instruments were collected during 10 days and exposed to a 1.5% dilution of glucoprotamin without prior washing. Bioburden before disinfection ranged from 2 × 105to 7.1 × 107CFU per instrument. Average bacterial killing was 5.98 log10CFU ± 0.48 under aerobic conditions and 6.75 log10CFU ± 0.54 under anaerobic conditions, despite the presence of large amounts of proteins on instruments that were frequently bloody. No vegetative bacteria were isolated in any sample after disinfection.

Conclusion:

This clinical study confirmed excellent in vitro efficacy of glucoprotamin without prior removal of proteins and debris.
Effectiveness of Gentamicin-Impregnated Cement in the Prevention of Deep Wound Infection After Primary Total Knee Arthroplasty
Authors: Eveillard Matthieu , Mertl Patrice , Tramier Blaise , Eb François
Published: March 2006

Effectiveness of gentamicin-impregnated cement in preventing deep wound infection after total knee arthroplasty (TKA) was estimated using data from prospective surveillance. In multivariate analysis, the protective effect of gentamicin-impregnated cement on the development of infection was close to the limit of significance. Gentamicin-impregnated cement may prevent TKA infections.
Light-Activated Antimicrobial Coating for the Continuous Disinfection of Surfaces
Authors: Wilson Michael
Published: March 2006

The ability of a photosensitizer-containing cellulose acetate film to kill bacteria was evaluated. Substantial kills were achieved following irradiation of the film with white light for up to 24 hours. Applying a photosensitizer-containing coating to surfaces could reduce the environmental load of pathogens, thus helping to prevent infectious disease transmission.
A Survey of Latent Tuberculosis Infection Among Laboratory Healthcare Workers in New York City
Authors: Garber Elizabeth , Gabriel Pablo San , Lambert Lauren , Saiman Lisa
Published: March 2006

Objective:

To determine the prevalence of positive tuberculin skin tests (TSTs), incidence of TST conversion, risk factors for positive TSTs, and history of active TB among HCWs in microbiology laboratories in New York City.

Design:

Two-year survey from May 1999 to June 2001.

Setting:

Nineteen microbiology laboratories.

Results:

During the first year, interviews were conducted with 345 laboratory HCWs (mean, 18 HCWs per site; range, 2 to 51) to assess the prevalence of positive TSTs, but 3 (1%) could not recall their result and were excluded from further analyses. The mean age of the remaining 342 HCWs was 48 years; 68% (n = 233) were female, 54% (n = 183) received bacille Calmette-Guérin (BCG) vaccination, and 71% (n = 244) were foreign born. The prevalence of a positive TST was 57% (n = 196), but only 20% (n = 39) of the HCWs received isoniazid. The incidence of TST conversion in the second year of the study was 1% (1 of 108). Multivariate analysis identified age (odds ratio [OR] per year, 1.05; 95% confidence interval [CI95], 1.02–1.08), foreign birth (OR, 3.80; CI95, 1.98–7.28), BCG immunization (OR, 4.89; CI95, 2.72–8.80), and employment in a mycobacteriology laboratory (OR, 2.14; CI95, 1.25–3.68) as risk factors for a positive TST. Only one HCW had been treated for active TB.

Conclusions:

The prevalence of positive TSTs was high among laboratory HCWs, but the TST conversion rate was low. Higher rates of treatment for latent TB infection are desirable.
Prevalence of Tuberculin Skin Test Positivity and Conversions Among Healthcare Workers in New York City During 1994 to 2001
Authors: Cook Sharlette , Maw Khin Lay , Munsiff Sonal S. , Fujiwara Paula I. , Frieden Thomas R.
Published: March 2006

Objective:

To determine the prevalence of and risk factors for tuberculin skin test positivity and conversion among New York City Department of Health and Mental Hygiene employees.

Design:

Point-prevalence survey and prospective cohort analysis. Sentinel surveillance was conducted from March 1,1994, to December 31, 2001.

Participants:

HCWs in high-risk and low-risk settings for occupational TB exposure.

Results:

Baseline tuberculin positivity was 36.2% (600 of 1,658), 15.5% (143 of 922) among HCWs born in the United States, and 48.5% (182 of 375) among HCWs not born in the United States. There were 36 tuberculin conversions during 2,754 observation-years (rate, 1.3 per 100 person-years). For HCWs born in the United States, the risk for tuberculin conversion was greater in high-risk occupational settings compared with low-risk settings (OR 5.7; CI95, 1.7–19.2;P< .01). HCWs not born in the United States and those employed at the Office of the Chief Medical Examiner (OCME) were at high risk for baseline tuberculin positivity (OR, 3.2; CI95,1.7–5.8;P< .001); OCME HCWs (OR 4.7; CI95, 2.3–9.4;P< .001), those of Asian ethnicity (OR 4.3; CI95,1.4–13.5;P< .01), and older HCWs (OR, 1.0; CI95,1.0–1.1;p< .05) were at a higher risk for conversion.

Conclusions:

Although the prevalence of tuberculin positivity decreased after the peak of the recent TB epidemic in New York City, the conversion rate among HCWs in high-risk occupational settings for TB exposure was still greater than that among HCWs in low-risk settings. Continued surveillance of occupational TB infection is needed, especially among high-risk HCWs.
Costs of Implementing and Maintaining a Tuberculin Skin Test Program in Hospitals and Health Departments
Authors: Lambert Lauren , Rajbhandary Sameer , Qualls Noreen , Budnick Lawrence , Catanzaro Antonino , Cook Sharlette , Daniels-Cuevas Linda , Garber Elizabeth , Reves Randall
Published: March 2006

Objective:

To determine (1) the annual costs of implementing and maintaining tuberculin skin test (TST) programs at participating study sites, (2) the cost of the TST program per healthcare worker (HCW), and (3) the outcomes of the TST programs, including the proportion of HCWs with a documented TST conversion and the proportion who accepted and completed treatment for latent TB infection, before and after the implementation of staffTRAK-TB software (Centers for Disease Control and Prevention, Atlanta, GA).

Design:

Cost analysis in which costs for salaries, training, supplies, radiography, and data analysis were collected for two 12-month periods (before and after the implementation of staffTRAK-TB).

Setting:

Four hospitals (two university and two city) and two health departments (one small county and one big city).

Results:

The annual cost of implementing and maintaining a TST program ranged from $66,564 to $332,728 for hospitals and $92,886 to $291,248 for health departments. The cost of the TST program per HCW ranged from $41 to $362 for hospitals and $176 to $264 for health departments.

Conclusions:

Costs associated with implementing and maintaining a TST program varied widely among the participating study sites, both before and after the implementation of staffTRAK-TB. Compliance with the TB infection control guidelines of the Centers for Disease Control and Prevention may require a substantial investment in personnel time, effort, and commitment.
Potential Nosocomial Exposure toMycobacterium tuberculosisFrom a Bronchoscope
Authors: Larson Janet L. , Lambert Lauren , Stricof Rachel L. , Driscoll Jeffrey , McGarry Michael A. , Ridzon Renée
Published: March 2006

Objective:

To investigate a possible nosocomial outbreak of tuberculosis (TB).

Design:

Retrospective cohort study.

Setting:

Community hospital.

Methods:

We reviewed medical records, hospital infection control measures, and potential locations of nosocomial exposure. We examined the results of acid-fast bacilli (AFB) smears, cultures, and drug susceptibility testing, and performed a DNA fingerprint analysis. We observed laboratory specimen processing procedures and bronchoscope disinfection procedures. We also reviewed bronchoscopy records.

Results:

In October 2000, three patients had bronchoscopy specimen cultures that were positive forMycobacterium tuberculosis.Of the three, only one had clinical signs and symptoms consistent with TB and positive AFB sputum smears. The other two did not have signs and symptoms consistent with TB and had no known exposure to individuals with infectious TB. The threeM. tuberculosisisolates had matching DNA fingerprints. No evidence of laboratory cross-contamination was identified. The three culture-positive specimens ofM. tuberculosiswere collected with the same bronchoscope within 9 days. This bronchoscope was inadequately cleaned and disinfected between patients, and the automated reprocessor used was not approved for use with the hospital bronchoscope.

Conclusions:

One of the bronchoscopes at this hospital was contaminated withM. tuberculosisduring bronchoscopy of an AFB-smear-positive patient. Subsequent specimen contamination likely occurred because the bronchoscope had been inadequately cleaned and disinfected. Patients who subsequently underwent bronchoscopy were also potentially exposed toM. tuberculosisfrom this bronchoscope.
Use of, Effectiveness of, and Attitudes Regarding Influenza Vaccine Among House Staff
Authors: Lester Richard T. , McGeer Allison , Tomlinson George , Detsky Allan S.
Published: March 2006

Objective:

To determine influenza vaccination rates, vaccine effectiveness, and factors influencing vaccination decisions among house staff.

Design:

Cross-sectional survey.

Setting and Participants:

All residents registered at the University of Toronto were surveyed after the 1999-2000 influenza season. Of the 1,159 questionnaires mailed, 670 (58%) could be evaluated.

Results:

Influenza-like illnesses were reported by 36% of house staff. The vaccination rate was 51% among respondents, being highest for community and occupational medicine and pediatric staff (77% and 75%) and lowest for psychiatry, surgery, and radiology staff (32%, 36%, and 36%). Vaccinees reported significantly fewer episodes of illness (42 vs 54 per 100 subjects; P = .03) and fewer days of illness (272 vs 374 per 100 subjects; P = .02); absenteeism was not different (63 vs 69 per 100 subjects; P = .69). Self-protection was the most common reason for vaccination. Vaccinees believed the vaccine was more effective than did non-vaccinees (P < .01). Non-vaccinees considered influenza-like symptoms the most important side effect of the vaccine. Busy schedules and inconvenience were the most common reasons for not getting vaccinated. Overall, 44% of house staff believed the influenza vaccine should be mandatory.

Conclusions:

Influenza-like illness was common among house staff. They tended to work through their illnesses, potentially putting patients at risk. They were motivated mostly by self-protection and did report a benefit. Despite busy schedules and an unfounded fear of getting influenza symptoms from the vaccine, many thought the vaccine should be mandatory.
Correlation Between Healthcare Workers' Knowledge of Influenza Vaccine and Vaccine Receipt
Authors: Martinello Richard A. , Jones Laura , Topal Jeffrey E.
Published: March 2006

Objective:

Influenza vaccine receipt by healthcare workers (HCWs) is important because HCWs are at risk for occupational exposure to influenza and may act as vectors in the nosocomial transmission of influenza. HCWs were surveyed to determine whether belief in commonly held influenza vaccine misconceptions was associated with influenza vaccine acceptance.

Design:

Cross-sectional study.

Setting:

A large urban teaching hospital.

Method:

A self-administered survey was used to assess nursing and physician staff influenza vaccine knowledge, current vaccination status, and potential reasons for vaccine declination.

Results:

Two hundred twelve of 215 surveys were completed. The overall influenza vaccination rate was 73%. Physician staff were significantly more likely to have been vaccinated compared with nursing staff (82% vs 62%, respectively; P = .0009). HCWs answering the 5 influenza vaccine basic knowledge questions correctly were significantly more likely to have been vaccinated than those responding incorrectly to any question (84% vs 64%, respectively; P = .002). This association was present in the nursing group where 80% of those answering the knowledge questions correctly were vaccinated, but only 49% of those answering incorrectly were vaccinated (P = .000005). However, in the physician group, there was no significant difference in the influenza vaccination rates between those answering correctly and those answering incorrectly (P = .459).

Conclusion:

Belief in commonly held influenza vaccine misconceptions was significantly associated with influenza vaccine declination among nursing staff and may act as a barrier to greater rates of influenza vaccination. Reasons for influenza vaccine nonreceipt may differ between nursing and physician staff.
A Preventable Outbreak of Pneumococcal Pneumonia Among Unvaccinated Nursing Home Residents in New Jersey During 2001
Authors: Tan Christina G. , Ostrawski Stanley , Bresnitz Eddy A.
Published: March 2006

Objective:

To characterize risk factors for invasive pneumococcal infection in a nursing home outbreak.

Design:

Outbreak investigation, case-control study.

Setting:

A 114-bed nursing home in New Jersey.

Participants:

Case-patients were nursing home residents hospitalized with febrile respiratory illness and radiographic findings consistent with pneumonia, and either sputum specimens positive for diplococci or blood cultures positive for Streptococcus pneumoniae, with illness onset during April 3-24, 2001. Control-patients were selected randomly from remaining residents without respiratory symptoms.

Methods:

Chart reviews were performed for case-patients and control-patients. Serotyping and susceptibility testing were performed on S. pneumoniae isolates. Long-term-care facilities (LTCFs) were surveyed to assess compliance with a state regulation mandating pneumococcal vaccination of residents 65 years and older.

Results:

Nine case-patients were identified, with a median age of 86 years (range, 78 to 100 years). The median age of control-patients was 86 years (range, 58 to 95 years). No case-patients versus 9 (50%) control-patients received pneumococcal vaccine before the outbreak (OR, 0; CI95, 0–0.7). Recent antibiotic use, pneumonia history, and physical functioning were not associated with illness. Illness attack rate was 16% among all unvaccinated residents versus 0 among vaccinated residents. S. pneumoniae serotype 14, included in pneumococcal vaccine, was isolated from blood cultures of 7 case-patients. Of 361 LTCFs (42%) that replied to the survey, 28 (8%) were not complying with state immunization regulations.

Conclusions:

This outbreak occurred in an LTCF with low vaccine coverage. Implementing standing order programs, enforcing regulations, documenting vaccinations, and providing education might increase coverage among nursing home residents.
Ventilator-Associated Pneumonia in a Multi-Hospital System Differences in Microbiology by Location
Authors: Babcock Hilary M. , Zack Jeanne E. , Garrison Teresa , Trovillion Ellen , Kollef Marin H. , Fraser Victoria J.
Published: March 2006

Objective:

To determine whether there were differences in the microbiologic etiologies of ventilator-associated pneumonia in different clinical settings.

Design:

Observational retrospective cohort study of microbiologic etiologies of ventilator-associated pneumonia from 1998 to 2001 in a multi-hospital system. Microbiologic results were compared between hospitals and between different intensive care units (ICUs) within hospitals.

Setting:

Three hospitals—one pediatric teaching hospital, one adult teaching hospital, and one community hospital— in one healthcare system in the midwestern United States.

Patients:

Patients at the target hospitals who developed ventilator-associated pneumonia and for whom microbiologic data were available.

Results:

Seven hundred fifty-three episodes of ventilator-associated pneumonia had culture data available for review. The most common organisms at all hospitals wereStaphylococcus aureus(28.4%) andPseudomonas aeruginosa(25.2%). The pediatric hospital had higher proportions ofEscherichia coli(9.5% vs 2.3%;P< .001) andKlebsiella pneumoniae(13% vs 3.1%;P< .001) than did the adult hospitals. In the pediatric hospital, the pediatric ICU had higherP. aeruginosarates than did the neonatal ICU (33.3% vs 17%;P= .01). In the adult hospitals, the surgical ICU had higherAcinetobacter baumanniirates (10.2% vs. 1.7%;P< .001) than did the other ICUs.

Conclusions:

Microbiologic etiologies of ventilator-associated pneumonia vary between and within hospitals. Knowledge of these differences can improve selection of initial antimicrobial regimens, which may decrease mortality.
Is Cutaneous Tuberculosis Infectious? A Case Presentation and Practical Management Plan
Authors: Hui Charles , Garg Amit X. , Pennie Ross
Published: March 2006

Infection control measures for cutaneous tuberculosis in the absence of pulmonary disease are problematic. Delays in diagnosis can lead to the exposure of many individuals. This article describes a case of cutaneous tuberculosis and the subsequent contact investigation. Strategies for infection control and their practicality are discussed.
Role of Comorbidity in Mortality Related to Staphylococcus aureus Bacteremia: A Prospective Study Using the Charlson Weighted Index of Comorbidity
Authors: Lesens Olivier , Methlin Cédric , Hansmann Yves , Remy Véronique , Martinot Martin , Bergin Colm , Meyer Pierre , Christmann Daniel
Published: March 2006

Objective:

To demonstrate the effectiveness of the Charlson weighted index of comorbidity (WIC) for controlling comorbidity in prospective studies focusing on mortality in patients with Staphylococcus aureus bacteremia (SAB).

Design:

Cohort study.

Setting:

Two tertiary-care, university-affiliated hospitals in France.

Patients:

One hundred sixty-six inpatients 18 years or older consecutively diagnosed with SAB from May 15, 2001, to May 15, 2002.

Methods:

Patients were prospectively assessed and cases were followed by the infectious diseases consult service at least 3 months after effective antibiotic therapy completion. The Charlson WIC was computed and dichotomized into scores of fewer than 3 points and 3 or more points. Bacteremia source, acute complication due to SAB acquisition in the ICU, and inappropriate empiric antibiotic therapy were recorded. The endpoint was death due to SAB and overall mortality.

Results:

In univariate analysis, the Charlson WIC was able to predict overall mortality and S. aureus-related death. The following variables were found to be independently predictive of mortality due to SAB using the Cox model: an acute complication due to S. aureus (OR, 8.9; CI95, 4 to 19.7; P < .001), a Charlson WIC score of 3 or more (OR, 3; CI95, 1.3 to 5.5; P = .006), and age (OR, 1.04; CI95, 1.009 to 1.07; P < .01).

Conclusions:

Comorbidity contributes to death in patients with SAB. The Charlson WIC is a good predictor of mortality in this population and may be a useful instrument to control comorbidity in studies aiming to investigate risk factors for death due to bacteremia.
Outcomes of Hickman Catheter Salvage in Febrile Neutropenic Cancer Patients WithStaphylococcus aureusBacteremia
Authors: Kim Sung-Han , Kang Cheol-In , Kim Hong-Bin , Youn Sung-Soo , Oh Myoung-don , Kim Eui-Chong , Park Seon-Yang , Kim Byoung-Kook , Choe Kang-Won
Published: March 2006

Objective:

To evaluate the outcome of attempted Hickman catheter salvage in neutropenic cancer patients withStaphylococcus aureusbacteremia who were not using antibiotic lock therapy.

Design:

Retrospective cohort study.

Setting:

A university-affiliated, tertiary-care hospital with 1,500 beds for adult patients.

Patients:

All neutropenic cancer patients who had a Hickman catheter andS. aureusbacteremia (32 episodes in 29 patients) between January 1998 and March 2002.

Methods:

Salvage attempts were defined as cases where the Hickman catheter was not removed until we obtained the results of follow-up blood cultures performed 48 to 72 hours after starting treatment with antistaphylococcal antibiotics. Salvage was considered to be successful if the Hickman catheter was still in place 3 months later without recurrent bacteremia or death.

Results:

Catheter salvage was attempted in 24 (75%) of the 32 episodes. Of the salvage attempts, the success rate was 50% (12 of 24). Salvage attempts were successful in 14% (1 of 7) of the episodes with positive follow-up blood cultures, and in 65% (11 of 17) of those with negative follow-up blood cultures (P= .07). If the analysis is confined to cases with no external signs of catheter infection, salvage attempts were successful in 14% (1 of 7) of the episodes with positive follow-up blood cultures and in 80% (8 of 10) of those with negative follow-up blood cultures (P= .02).

Conclusion:

In neutropenic cancer patients withS. aureusbacteremia, attempted catheter salvage without antibiotic lock therapy was successful in 50% of the cases.