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A participatory ergonomics programme was implemented in an automotive parts manufacturing factory in which an ergonomics change team was formed, composed of members from management, the organized labour union and the research team. It was hypothesized that the participatory nature of this change process would result in enhanced worker perceptions of workplace communication dynamics, decision latitude and influence, which in conjunction with anticipated mechanical exposure reductions would lead to reduced worker pain severity. Utilizing a sister plant in the corporation as a referent group, a quasi-experimental design was employed with a longitudinal, repeat questionnaire approach to document pre-post intervention changes. Nine participatory activities (psychosocial interventions) were implemented as part of the process. Communication dynamics regarding ergonomics were significantly enhanced at the intervention plant compared to the referent plant. However, there were no significantly different changes in worker perceptions of decision latitude or influence between the two plants, nor did pain severity change. Possible explanations for these results include limited intervention intensity, context and co-intervention differences between the two plants, high plant turnover reducing the statistical power of the study and lack of sensitivity and specificity in the psychosocial measures used. Further research should include the development of psychosocial tools more specific to participatory ergonomic interventions and the assessment of the extent of change in psychosocial factors that might be associated with improvements in pain.

Chlamydia trachomatis is the most common sexually transmitted bacterial infection in the United States. Utilizing cloned murine oviduct epithelial cell lines, we previously identified Toll-like receptor 2 (TLR2) as the principal epithelial pattern recognition receptor (PRR) for infection-triggered release of the acute inflammatory cytokines interleukin-6 and granulocyte-macrophage colony-stimulating factor. The infected oviduct epithelial cell lines also secreted the immunomodulatory cytokine beta interferon (IFN-beta) in a largely MyD88-independent manner. Although TLR3 was the only IFN-beta production-capable TLR expressed by the oviduct cell lines, we were not able to determine whether TLR3 was responsible for IFN-beta production because the epithelial cells were unresponsive to the TLR3 ligand poly(I-C), and small interfering RNA (siRNA) techniques were ineffective at knocking down TLR3 expression. To further investigate the potential role of TLR3 in the infected epithelial cell secretion of IFN-beta, we examined the roles of its downstream signaling molecules TRIF and IFN regulatory factor 3 (IRF-3) using a dominant-negative TRIF molecule and siRNA specific for TRIF and IRF-3. Antagonism of either IRF-3 or TRIF signaling significantly decreased IFN-beta production. These data implicate TLR3, or an unknown PRR utilizing TRIF, as the source of IFN-beta production by Chlamydia-infected oviduct epithelial cells.

At first glance, the accompanying article by Silas et al. makes for a somewhat-curious read. The picture they paint of the possible risk of a global pandemic posed by the avian influenza virus H5N1 is indeed a chilling one, not only for the possible extent of the epidemic itself but also because of the likely burden it could place on an already thinly stretched healthcare workforce. It therefore raises a rather alarming contradiction. Given our recent experience of living through the consequences of the outbreak of severe acute respiratory syndrome in Ontario and BC, one would think that we would be more than willing this time around to err on the side of caution and be as prepared as possible to deal with the next emerging infectious agent that comes our way. But, surprisingly, as is carefully outlined in Silas et al.'s paper, this does not seem to be the case. In a healthcare environment that is increasingly focused on the need for evidence upon which to base change in practice, are we possibly dragging our heels in raising our preparedness for a future pandemic? It is an interesting debate, and one that certainly merits further examination.

There is significant personal injury risk associated with the provision of high-quality healthcare. The magnitude of this risk, combined with the possibility that it can often go underappreciated by caregivers and the organizations they work for, might help explain why the health sector has largely missed out on the benefits of an overall declining trend in injury rates. Despite covering two very different topics in their lead papers, Shamian and El-Jardali and Clements, Dault and Priest present a surprising degree of overlap in relation to what might help enable effective workplace change. Leadership, role clarity, trust, respect, values and workplace culture are all viewed as key enablers of effective teamwork by Clements, Dault and Priest. They could also be considered required ingredients of successful workplace health initiatives, as discussed by Shamian and El-Jardali. A lot of background and positional work regarding teamwork and healthy workplaces exists, but this has not necessarily translated into front-line change. These authors have done an excellent job of pointing out the potential benefits of workplace changes. What is needed now is for someone to take the lead in developing, implementing and evaluating these changes. The adult human form is an awkward burden to lift or carry. Weighing up to 200 pounds or more, it has no handles, it is not rigid, and it is susceptible to severe damage if mishandled or dropped. When lying in bed, a patient is placed inconveniently for lifting and the weight and placement of such a load would be tolerated by few industrial workers.

Background: Participatory ergonomic (PE) interventions have been increasingly utilized to deal with work-related musculoskeletal disorders (WMSD)., Methods: Using a longitudinal quasi-experimental design, a PE process was launched at one depot of a large courier company, with a nearby depot serving as a control. Evaluations focused on 122 employees across the two depots who participated in both pre- and post-questionnaires. An evaluation framework assessed the process of implementation, changes in risk factors, and changes in musculoskeletal health outcomes. Partial and multiple regressions explored the relationships in the evaluation framework., Results: Changes in work organizational factors had a consistent impact upon changes in health outcomes. Greater participation in the process was associated with increased levels of job influence and communication (P = 0.0059 and P = 0.0940 respectively). Improvements in communication levels were associated with reduced pain intensity and improved work role function (WRF) (P = 0.0077 and P = 0.0248 respectively). Lower levels of pain post-intervention were related to greater WRF (P = 0.0493)., Conclusions: A PE approach can improve risk factors related to WMSD, and meaningful worker participation in the process is an important aspect for the success of such interventions.

Chlamydia trachomatis is the most common bacterial sexually transmitted disease in the United States and a major cause of female infertility due to infection-induced Fallopian tube scarring. Epithelial cells are likely central to host defense and pathophysiology as they are the principal cell type productively infected by C. trachomatis. We generated cloned murine oviduct epithelial cell lines without viral or chemical transformation to investigate the role of the TLRs and cytosolic nucleotide binding site/leucine-rich repeat proteins Nod1 and Nod2 in epithelial responses to Chlamydia muridarum infection. RT-PCR assays detected mRNA for TLR2 (TLRs 1 and 6), TLR3, and TLR5. No mRNA was detected for TLRs 4, 7, 8, and 9. Messenger RNAs for Nod1 and Nod2 were present in the epithelial cell lines. Oviduct epithelial cell lines infected with C. muridarum or exposed to the TLR2 agonist peptidoglycan secreted representative acute phase cytokines IL-6 and GM-CSF in a MyD88-dependent fashion. Infected epithelial cell lines secreted the immunomodulatory cytokine IFN-beta, even though C. muridarum does not have a clear pathogen-associated molecular pattern (PAMP) for triggering IFN-beta transcription. The oviduct epithelial lines did not secrete IFN-beta in response to the TLR2 agonist peptidoglycan or to the TLR3 agonist poly(I:C). Our data identify TLR2 as the principal TLR responsible for secretion of acute phase cytokines by C. muridarum-infected oviduct epithelial cell lines. The pattern recognition molecule responsible for infection-induced IFN-beta secretion by oviduct epithelial cells remains to be determined.

[reaction: see text] The promising utility of triazolyl N-heterocyclic carbene catalysts in umpolung aldehyde chemistry requires a straightforward reliable synthesis from readily available materials. Herein, we describe the synthesis of a variety of triazolyl N-heterocyclic carbene precursors. The reactions commence from commercially available amino acids and proceed in 44-68% overall yields. The N-heterocyclic salts are air-stable crystalline solids that can be stored with no special precaution and can generate the active catalyst when treated with an appropriate base.

Background: Back pain continues to be the leading overall cause of morbidity and lost productivity in the workplace. Recently, there has been a renewed interest in the use of back belts by industry to reduce occupational low back pain (LBP)., Objectives: To examine the literature and evaluate the effectiveness of back belt use for the primary prevention of occupational LBP., Methods: MEDLINE, CINAHL, EMBASE, and HEALTHSTAR were searched for relevant articles published up to July 2003. Studies were included if participants were material handlers, and outcomes included the incidence and/or duration of lost time of reported LBP among workers who wore back belts compared with those who did not. The quality of the evidence was scored independently by 2 reviewers using a double rating method, first according to research design followed by an internal validity rating. Final synthesis of the evidence was performed in which the evidence was classified as good, fair, conflicting, or insufficient., Results: Ten epidemiologic studies meeting inclusion criteria were identified. Of 5 randomized controlled trials, 3 showed no positive results with back belt use; 2 cohort studies had conflicting results; and 2 nonrandomized controlled studies and 1 survey showed positive results., Conclusions: Currently, because of conflicting evidence and the absence of high-quality trials, there is no conclusive evidence to support back belt use to prevent or reduce lost time from occupational LBP.

A participatory ergonomics programme was implemented in an automotive parts manufacturing factory. An ergonomics change team was formed composed of members from management and the organized labour union. It was hypothesized that the physical change projects implemented as part of this process would result in decreased worker exposures to peak and cumulative physical demands and reduced worker perceptions of physical effort and pain severity. A quasi-experimental design was employed, utilizing a sister plant in the corporation as a referent group. A longitudinal questionnaire approach was used to document pre-post changes in worker perceptions. In general, the physical change projects were rated as improvements by workers and were successful at reducing peak and/or cumulative mechanical exposures. However, there were few systematic changes in perceived effort or pain severity levels. Explanations include the confounding effects of differential production rate and staffing changes at the intervention and referent plants and/or insufficient overall intervention intensity due to a relatively short intervention period, plant and team ambivalence towards the process and the low overall impact on exposure of the particular changes implemented.

The aim of this descriptive study was to help policy- and decision-makers enhance the health of the Canadian nursing workforce by highlighting key factors of concern and exploring options for collecting and utilizing nurses' health data. This paper describes the views of 62 nursing stakeholders from a diverse spectrum of professional, labour, management and government perspectives from across Canada, regarding key factors contributing to work-related health problems in the nursing profession, particularly those relating to the work environment and hospital restructuring. The results were combined with a synthesis of existing information sources about the health of nurses in Canada. With respect to the key concerns, musculoskeletal conditions/injuries and stress and burnout were identified as nurses' major work-related health problems. An examination of the data synthesis inventory revealed that no existing data sources can adequately profile nurses' health, especially in relation to the components of the Conceptual Model of Nurses' Health developed in the study. Three strategies for monitoring nurses' health are proposed.

A new electron-deficient chiral triazolium salt has been shown to catalyze the formation of quaternary stereocenters by an asymmetric intramolecular Stetter reaction. Pentafluorophenyl substitution on an aminoindanol-derived catalyst affords tertiary ether, thioether, and quaternary stereocenters in typically greater than 90% ee and very good chemical yield. Aromatic and aliphatic aldehydes are equally competent substrates for this reaction. The reaction proceeds at room temperature under mild conditions to provide quaternary stereocenters with functional group relationships that are particularly difficult to access by other methods.

The purpose of this study was to test an expanded model of Rosabeth Moss Kanter's Structural Theory of Organizational Behaviour (Kanter 1977; Laschinger, Finegan, Shamian and Wilk 2001) by examining the relationship between nurses' empowerment and their perceptions of effort-reward imbalance (Siegrist 1996). A sample of 112 staff nurses employed in teaching hospitals in Ontario participated in this study (58% return rate). A descriptive correlational survey design was used to collect data by eLiciting responses to five self-report instruments: the Conditions of Work Effectiveness II, the Job Activities Scale II, and the Organizational Relationships Scale II (Laschinger, Finegan, Shamian and Wilk 2001), the Effort-Reward Imbalance (ERI) scale (Siegrist and Peter 1999a) and a demographic questionnaire. Staff nurses were only moderately empowered, and 24.1% perceived their work to have more efforts than rewards, according to Siegrist's guidelines.

Researchers of work-related musculoskeletal disorders are increasingly asked about the evidentiary base for mechanical exposure reductions. Mixed messages can arise from the different disciplinary cultures of evidence, and these mixed messages make different sets of findings incommensurate. Interventions also operate at different levels within workplaces and result in different intensities of mechanical exposure reduction. Heterogeneity in reporting intervention processes and in measuring relevant outcomes makes the synthesis of research reports difficult. As a means of synthesizing the current understanding of measures, this paper describes a set of intervention and observation nodes for which relevant workplace indicators prior to, during, and after mechanical exposure reduction can provide useful information. On the basis of this path of impacts from exposure reduction, an approach to the evaluation of multilevel ergonomic interventions is described that can assist fellow researchers in producing evidence relevant to the challenges faced by workplace parties and policy makers.

A family of chiral triazolium salts has been developed for inducing the asymmetric intramolecular Stetter reaction. The use of an aminoindanol-derived catalyst affords optimal results, with the product keto esters formed in 82-97% ee and very good chemical yield. Aromatic and aliphatic aldehydes are equally competent substrates for this reaction. The reaction conditions are reasonably mild and allow the isolation of the newly formed stereocenter without epimerization, although the presumed carbenic intermediates are strong bases.

Objective: This paper reviews the psychometric properties of the core components from Karasek's job content questionnaire, the decision latitude and psychological job demands scales., Methods: A self-reported survey was administered in 1995 (time 1), 1996 (time 2), and 1997 (time 3) to employees of a large teaching hospital. Analyses for this paper are based on data from the 484 employees who responded at times 1 and 2., Results: Both scales demonstrated acceptable internal consistency as assessed by item-total correlations and Cronbach's alpha. In confirmatory factor analysis, the two-factor decision latitude model adequately fit the data. However, our findings suggest that a two-factor model may provide an improved fit over the original one-factor demands model, suggesting that this scale may be two distinct subscales. Lastly, the scales demonstrated acceptable discriminant validity., Conclusion: Apart from some guarded uncertainty over what the demands scale may be measuring, overall, the two scales appeared to perform reasonably well in this sample of health care workers.

Characterization of virulence traits in Actinobacillus actinomycetemcomitans requires the application of recombinant DNA techniques. To develop appropriate genetic tools it is necessary to identify suitable host-vector systems. The current study assessed cloning parameters in A. actinomycetemcomitans for two previously described vectors, pDMG4 and pMMB67. It was determined that the maximum size of recombinant molecules that could be transferred to A. actinomycetemcomitans strain ATCC29522 via electroporation was 33 kb. The size limit for transformation of the same strain with ligation mixtures (direct cloning), however, was limited to 23-24 kb. Additional experiments included electroporation of various A. actinomycetemcomitans strains with plasmid DNA isolated from Escherichia coli and different A. actinomycetemcomitans sources. Differences in transformation efficiencies suggested the presence of a restriction modification system for pDMG4 in some strains of A. actinomycetemcomitans. Cloning of portions of the enterococcal plasmid pJH1 into A. actinomycetemcomitans resulted in the insertion of the intact vector into the chromosome., (Copyright 2002 Elsevier Science (USA).)

Objectives: This paper examines the performance of 4 different methods of estimating peak spinal loading and their relationship with the reporting of low-back pain., Methods: The data used for this comparison was a subset of subjects from a case-referent study of low-back-pain reporting in the automotive industry, in which 130 random referents and 105 cases (or job-matched proxies) were studied. The peak load on the lumbar spine was determined using a biomechanical model with model inputs coming from a detailed self-report questionnaire, a task-based check list, a video digitization method, and a posture and load sampling technique., Results: The methods were directly comparable through a common metric of newtons or newton meters of spinal loading in compression, shear, or moment modes. All the methods showed significant and substantial associations with low-back pain in all modes (odds ratios 1.6-2.3). The intraclass correlation coefficients (ICC) showed strong similarities between the checklist and video digitized techniques (ICC 0.84-0.91), moderate similarities between these techniques and the work sampling method (ICC 0.49-0.52), and poor correlations (ICC 0.16-0.40) between the self-report questionnaire and the observer recorded measures., Conclusions: While all the methods detected significant odds ratios, they cannot all be used interchangeably for risk assessment at the individual level. Peak spinal compression, moment, and shear are important risk factors for low-back pain reporting, no matter which measurement method is used. Questionnaires can be used for large-scale studies. At the individual level a task-based checklist provides biomechanical model inputs at lower cost and equal performance compared with the criterion video digitization system.

In most industrialized countries, disability and work absence due to occupational back pain have risen steadily in recent decades. Conventional views of the causes of this slow epidemic tend to fall into one of the following three areas: (i) the clinical pathology view, which attributes the level of pain and disability to either the severity of the initial injury or to psychosomatic conditions; (ii) the biomechanical exposures view, which attributes the problem to hazardous and preventable conditions of work; and (iii) the perverse incentives view, which suggests that reporting and disability are influenced by a combination of work dissatisfaction and accessible disability benefits. This paper reviews, from an epidemiologic perspective, the specific methodological hurdles faced during investigations of the etiology of occupational back pain. It is argued that methodological issues have contributed to the perpetuation of the three distinct but incomplete views of the problem. New research directions are suggested and a broader interdisciplinary perspective is proposed to help resolve the existing polemic.

Hymenolepis diminuta migrates up the small intestine in response to feeding the host 1 g of glucose. Locomotion during migration may result from fixed patterns of retrograde peristaltic-like waves in the strobila of the tapeworm which propel the organism against the normal expulsive forces in the small intestine. The peristaltic-like locomotory waves occur in a gradient along the strobila with a frequency of 24.9 +/- 0.9 cycles/min in the anterior segments of the worm, decreasing linearly to 6.6 +/- 1.4 cycles/min in the posterior segments of the worm. Chemical signals, isolated from the small intestine of fed hosts, which stimulate migration behaviour in vivo do not alter the behaviour of the scolex or strobila in vitro. Removal of the scolex containing the cerebral ganglia does not alter the frequency or pattern of locomotory activity in the strobila. After the worm is cut into pieces, each region generates the pattern of locomotory activity that is appropriate for that region. These data suggest that the peripheral nervous system, and not the central nervous system, is responsible for the coordination of the fixed patterns of locomotory activity in these tapeworms.

We compared the ability of three thiols--dithiothreitol (DTT), cysteamine and WR-151326--to protect aerated Chinese hamster ovary cells from the lethal and DNA-damaging effects of gamma-radiation. These results were compared with earlier measurements for WR-1065 and WR-255591. The time-course and the concentration dependence of protection against cell killing was determined after 10 Gy of gamma-rays. The aminothiols cysteamine and WR-151326 protected at much lower extracellular concentrations than the simple thiol DTT; however, there was no clear difference between the behaviour of cysteamine, WR-151326, WR-1065 and WR-255591 in this respect. Protection by DTT and cysteamine was complete within 1 min, whereas for WR-151326, WR-1065 and WR-255591 about 30 min was required before protection began to reach a plateau. Based on these data, complete radiation survival curves were generated for each thiol and protection factors calculated. Effects on the induction of DNA single-strand breaks (ssb) and double-strand breaks (dsb) by gamma-rays were measured using alkaline (pH 12.1) and neutral (pH 7.0 and 9.6) elution, respectively. All three thiols protected against ssb induction, although to a significantly lower extent than against cell killing measured under identical conditions. Each thiol also protected against dsb induction. After high radiation doses the protection factors for dsb induction were also less than the protection factors for cell survival; however, when dsb were assayed using the low-dose replicate plating neutral elution method, the relative effect of each thiol on cell survival and on dsb induction appeared to be equivalent. The hierarchy of protection against both ssb and dsb induction (based on the extracellular thiol concentration required to produce a given degree of protection) was similar to that for cell survival, i.e., WR-151326 congruent to cysteamine less than DTT.

We examined the radioprotective effect of the aminothiol WR-255591 and its phosphorothioate derivative WR-3689 on aerated cultured Chinese hamster ovary cells. At concentrations up to 10 mmol dm-3, WR-3689 afforded little protection from the lethal effects of gamma-radiation. The free thiol WR-255591, on the other hand, efficiently protected these cells, giving a protection factor (PF) for cell survival of 2.3 at a concentration of 6 mmol dm-3. The effects of WR-255591 on the induction and rejoining of gamma-ray-induced DNA single-strand breaks (ssb) and double-strand breaks (dsb) were measured using alkaline (pH 12.1) and neutral (pH 7.0 or 9.6) elution, respectively. PFs calculated from these data were compared with the PFs measured for cell survival. WR-255591 (6 mmol dm-3) protected against the induction of both DNA ssb and dsb; however, the magnitude of the modification of both ssb (PF of 1.23) and dsb (PF of 1.83 at pH 7.0 and 1.70 at pH 9.6) was less than that for cell survival (PF of 2.3) measured under identical conditions (irradiation on ice). Treatment of cells with WR-255591 prior to irradiation retarded the subsequent rate of ssb rejoining but had no effect on dsb rejoining. Postirradiation treatment with the drug slightly retarded ssb rejoining but had no effect on cell survival. The observation of lower PFs for DNA strand breaks than for cell survival suggests that radioprotection by WR-255591 probably does not result from a uniform decrease in the induction of all types of DNA lesions. Rather, the drug may differentially protect against the induction of subclasses of DNA damage--which could also explain the effects on the kinetics of ssb rejoining--and/or enhance cellular recovery processes.

A negative chemographic effect, or fading of the latent image, has been found in autoradiographic studies of human red blood cells. The effect is heterogeneous, being restricted to a halo-shaped region over each cell.