Zymosan-Induced Peritonitis

Zymosan-induced peritonitis is a model commonly used to study systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). However, effects of zymosan on cardiac function have not been reported. We evaluated cardiac responses to zymosan in mice and the role of β-glucan and dectin-1 in mediating these responses. Temperature and cardiac function were evaluated before and after intraperitoneal (i.p.) injection of zymosan (100 or 500 mg/kg) or saline. Chronotropic and dromotropic functions were measured using electrocardiograms collected from conscious mice. Cardiac inotropic function was determined by echocardiography. High-dose zymosan caused rapid and maintained hypothermia along with visual signs of illness. Baseline heart rate (HR) was unaffected but HR variability increased, and there was a modest slowing of ventricular conduction. High-dose zymosan also caused prominent decreases in cardiac contractility at 4 and 24 h. Since zymosan is known to cause gastrointestinal tract pathology, peritoneal wash and blood samples were evaluated for bacteria at 24 h after zymosan or saline injection. Translocation of bacterial occurred in all zymosan-treated mice (n=3), and two had bacteremia. Purified β-glucan (50 and 125 mg/kg, i.p.) had no effect on temperature or ECG parameters. However, deletion of dectin-1 modified the ECG responses to high-dose zymosan; slowing of ventricular conduction and the increase in HR variability were eliminated but a marked bradycardia appeared at 24 h post-zymosan treatment. Zymosan-treated dectin-1 knockout mice also showed hypothermia and visual signs of illness. Fecal samples from dectin-1 knockout mice contained more bacteria than wild types, but zymosan caused less translocation of bacteria. Collectively, these findings demonstrate that zymosan induced systemic inflammation causes cardiac dysfunction in mice. The data suggest that dectin-1 dependent and independent mechanisms are involved. While zymosan treatment causes translocation of bacteria this effect does not have a major role in the overall systemic response to zymosan

sEMG Activity Contribution to Risk Assessment for PRM Assistance Workers

Aim of this study is to analyze the task of pushing Passengers with Restricted Mobility (PRM) on three different wheelchairs currently supplied in an Italian airport. The wheelchairs differed in their width, weight and wheel dimensions. We investigated the task with two different PRMs weight (100 and 55 kg) and three different caster wheels positions (0°, 90° and 180°). We computed the Average Rectified Value, as percentage of maximum voluntary contraction, recorded from Erector Spinae and Anterior Deltoid muscles bilaterally in the starting phase of pushing. We can conclude that by means of sEMG it is possible to obtain useful data about the risks of pushing and pulling tasks in addition to those obtained by measuring the applied forces. In future research, it could be useful to analyze also muscle co-activation to better understand the biomechanical risks of pushing and pulling tasks

Epidemiologic study of low back pain in 1398 Swiss conscripts between 1985 and 1992.

The two objectives of this study, based on a sample of 1398 Swiss army conscripts born in 1966 who participated in a first study in 1985, were to measure the prevalence of low back pain (LBP) at age 26 years and its incidence between 19 and 26 years and to analyze the relationship between LBP and occupational, nonoccupational, or physical risk factors. The lifetime prevalence of LBP at age 26 was 69.1% and the incidence of LBP between 19 and 26, 44.7%. A history of LBP or a pathological physical examination result at age 19 did not predict the prevalence or the incidence at age 26. Standing, twisting, vibration, and heavy work were significantly associated with chronic LBP and/or the 1-year prevalence of LBP at age 26 (P < 0.05). The evolution of sport and leisure-time activities from age 19 to 26 did not differ between people with or without LBP. The ergonomic organization of the workplace should represent a major element of future strategies to prevent LBP