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Salmonellosis is among the most reported foodborne illnesses in the United States. The Salmonella enterica Typhimurium DT104 phage type, which is associated with multidrug-resistant disease in humans and animals, possesses an ADP-ribosylating toxin called ArtAB. Full-length art AB has been found on a number of broad-host-range non-typhoidal Salmonella species and serovars. ArtAB is also homologous to many AB 5 toxins from diverse Gram-negative pathogens, including cholera toxin (CT) and pertussis toxin (PT), and may be involved in Salmonella pathogenesis, however, in vitro cellular toxicity of ArtAB has not been characterized. art AB was cloned into E. coli and initially isolated using a histidine tag (ArtABHIS) and nickel chromatography. ArtABHIS was found to bind to African green monkey kidney epithelial (Vero) cells using confocal microscopy and to interact with glycans present on fetuin and monosialotetrahexosylganglioside (GM1) using ELISA. Untagged, or native, holotoxin (ArtAB), and the pentameric receptor-binding subunit (ArtB) were purified from E. coli using fetuin and d-galactose affinity chromatography. ArtAB and ArtB metabolic and cytotoxic activities were determined using Vero and Chinese hamster ovary (CHO) epithelial cells. Vero cells were more sensitive to ArtAB, however, incubation with both cell types revealed only partial cytotoxicity over 72 h, similar to that induced by CT. ArtAB induced a distinctive clustering phenotype on CHO cells over 72 h, similar to PT, and an elongated phenotype on Vero cells, similar to CT. The ArtB binding subunit alone also had a cytotoxic effect on CHO cells and induced morphological rounding. Results indicate that this toxin induces distinctive cellular outcomes. Continued biological characterization of ArtAB will advance efforts to prevent disease caused by non-typhoidal Salmonella .

Staphylococcus aureus ( S. aureus ) is a primary agent of bovine mastitis and a source of significant economic loss for the dairy industry. We previously reported antigen-specific immune induction in the milk and serum of dairy cows following vaccination with a cholera toxin A 2 and B subunit (CTA 2 /B) based vaccine containing the iron-regulated surface determinant A (IsdA) and clumping factor A (ClfA) antigens of S. aureus (IsdA + ClfA-CTA 2 /B). The goal of the current study was to assess the efficacy of this vaccine to protect against S. aureus infection after intramammary challenge. Six mid-lactation heifers were randomized to vaccinated and control groups. On days 1 and 14 animals were inoculated intranasally with vaccine or vehicle control, and on day 20 animals were challenged with S. aureus . Clinical outcome, milk quality, bacterial shedding, and somatic cell count (SCC) were followed for ten days post-challenge. Vaccinated animals did not show signs of clinical S. aureus mastitis and had lower SCCs compared to control animals during the challenge period. Reductions in bacterial shedding were observed but were not significant between groups. Antibody analysis of milk and serum indicated that, upon challenge, vaccinated animals produced enhanced IsdA- and ClfA-CTA 2 /B specific immunoglobulin G (IgG) responses, while responses to CTA 2 /B alone were not different between groups. Responses after challenge were largely IgG1 against the IsdA antigen and mixed IgG1/IgG2 against the ClfA antigen. In addition, there was a significant increase in interferon gamma (IFN-γ) expression from blood cells in vaccinated animals on day 20. While preliminary, these findings support evidence of the induction of active immunity by IsdA + ClfA-CTA 2 /B, and further assessment of this vaccine is warranted.

Background: The aim of this study was to examine relations between computer work aspects and elbow and wrist/hand pain conditions and disorders., Methods: In a 1-year follow-up study among 6,943 technical assistants and machine technicians self-reported active mouse and keyboard time, ergonomic exposures and associations with elbow and wrist/hand pain were determined. Standardized clinical examinations were performed among symptomatic participants at baseline and at follow-up., Results: For continuous duration of mouse time adjusted linear effects were statistically significant for all investigated pain conditions. For continuous duration of keyboard time the corresponding effects were statistically significant for wrist/hand pain conditions except incident 'severe' wrist/hand pain. There were no threshold effects above 0 hr per week (hr/w) of mouse exposure in association with pain conditions, while keyboard exposure showed a threshold effect with 12-month wrist/hand pain at follow-up. Clinical diagnoses were not associated with exposure., Conclusions: Detailed examination of self-reported exposures showed that mouse and keyboard time predicted elbow and wrist/hand pain from low exposure levels without a threshold effect, but mouse and keyboard time were not predictors of clinical conditions., (Copyright 2004 Wiley-Liss, Inc.)

Objectives: Neck and shoulder pain and disorders were studied among frequent computer users, and the associated effect of mouse and keyboard use was evaluated., Methods: Technical assistants and machine technicians were followed for 1 year. Questionnaires were sent to 9480 persons (initial response 73%, follow-up response 82%). Computer use information was obtained from the questionnaires. Symptom cases at baseline and follow-up were clinically examined using a standardized clinical protocol. The main outcomes were self-reported pain symptoms in the neck and right shoulder and clinical cases of rotator cuff syndrome, tension neck syndrome, and neck-shoulder pain with pressure tenderness., Results: The prevalence of moderate-to-severe pain in the neck and right shoulder was 4.1% and 3.4%, respectively, and the 1-year incidence for no or minor baseline symptoms was 1.5% and 1.9%, respectively. At baseline, the prevalence rate ratio (PRR) for neck pain was 1.7 [95% confidence interval (95% CI) 1.1-2.6] for mouse use >25 hours/week, that for right shoulder pain increased from 1.6 (95% CI 1.1-2.4) for 15-19 hours/ week to 2.5 (95% CI 1.4-4.3) for >30 hours/week of mouse use, and that for tension neck syndrome increased from 3.5 (95% CI 1.0-12) for 25-29 hours/week to 4.7 (95% CI 1.2-18) for >30 hours/week of mouse use. The relative risk (RR) for new neck pain was 1.8 (95% CI 0.8-3.9) for keyboard use > or = 15 hours/week and increased to 2.4 (95% CI 0.8-6.8) for > or = 30 hours/week. New right-shoulder pain symptoms were associated with mouse use >20 hours/week (RR 1.9, 95% Cl 1.0-3.5, and RR 3.3, 95% CI 1.2-8.9) and with keyboard use >15 hours/week (RR 2.2, 95% CI 1.0-4.9)., Conclusions: Mouse use is associated with an increased risk of moderate-to-severe pain in the neck and right shoulder, and an association with tension neck syndrome is possible.

Context: Computer use is increasingly common among many working populations, and concern exists about possible adverse effects of computer use, such as carpal tunnel syndrome (CTS)., Objectives: To estimate the prevalence and incidence of possible CTS and to evaluate the contribution of use of mouse devices and keyboards to the risk of possible CTS., Design and Setting: A 1-year follow-up study with questionnaires conducted in 2000 and 2001 at 3500 workplaces in Denmark, followed on each of the 2 occasions by a clinical interview on symptom distribution and frequency., Participants: The questionnaire was sent to 9480 members of a trade union, with an initial response rate of 73% (n = 6943), and 82% (n = 5658) at follow-up., Main Outcome Measures: At baseline, there were 3 outcome measures: tingling/numbness in the right hand once a week or more as reported in the questionnaire; tingling, numbness, and pain in the median nerve in the right hand confirmed by clinical interview; and tingling, numbness, and pain in the median nerve in the right hand at night confirmed by clinical interview. At 1 year of follow-up the main outcome of interest was onset of symptoms among participants who had no or minor symptoms at baseline., Results: The overall self-reported prevalence of tingling/numbness in the right hand at baseline was 10.9%. The interview confirmed that prevalence of tingling/numbness in the median nerve was 4.8%, of which about one third, corresponding to a prevalence of 1.4%, experienced symptoms at night. Onset of new symptoms in the 1-year follow-up was 5.5%. In the cross-sectional comparisons and in the follow-up analyses, there was an association between use of a mouse device for more than 20 h/wk and risk of possible CTS but no statistically significant association with keyboard use., Conclusions: The occurrence of possible CTS in the right hand was low. The study emphasizes that computer use does not pose a severe occupational hazard for developing symptoms of CTS.

Chronic inflammation of the skin and mucous membranes following prolonged exposure to high doses of toxic hexavalent chromium is well known in the occupational medical literature. Perforation of the nasal septum is a cardinal clinical feature. Late development of cancer in the respiratory system is established. A recently diagnosed case with an unusually severe affect on the eyes is described. The industrial usage of chromium and its toxicological profile is reviewed.