The cost and distribution of firefighter injuries in a large Canadian Fire Department.

BACKGROUND: There is limited data available regarding the cost of firefighter injuries. This information is necessary to develop targeted injury prevention strategies. OBJECTIVE: To categorize the cost of injuries filed in 2012 by firefighters from a from a large department by job duty, injury type, body part affected, and the general motion pattern employed at the time of injury. METHODS: Data were taken from reports filed by CFD personnel and claims filed with the Workers' Compensation Board (WCB) of Alberta between January 1, 2012 and December 31, 2012. RESULTS: Of the 244 injuries reported, 65% were categorized as sprains and strains, the most frequent of which affected the back (32%). The total cost of all claims was $555,955; 77% were sprain/strain-related. Knee and back injuries were most costly ($157,383 and $100,459). Categorized by job duty, most sprains/strains (31%) were sustained while attending to fire station responsibilities, although physical training was associated with the highest costs (34%). Fireground operations were attributed to 18% of sprains/strains and 16% of costs. Lifting injuries were more frequent (23%) and costly (20%) than all injuries. CONCLUSIONS: The most common and costly injuries occurred while attending to fire station-related responsibilities and during physical training.

Firefighter injuries are not just a fireground problem.

BACKGROUND: Linking firefighter injury reporting to general motion patterns may provide insight into potential injury mechanisms and the development of prevention strategies. OBJECTIVE: To characterize the injuries sustained by members of a large Canadian metropolitan fire department over a 5-year span. METHODS: Data were taken from injury reports filed by career firefighters between 2007 and 2011. Injuries were described by job duty, type, body part affected, and the general motion pattern employed at the time of injury (e.g. lifting). RESULTS: Of the 1311 injuries reported, 64% were categorized as sprains and strains (musculoskeletal disorders -MSDs), the most frequent of which affected the back (32%). Categorized by job duty, 65% of MSDs were sustained while working at the fire station or during physical training-related activities. Only 15% were attributed to fireground operations. Furthermore, the associated job duty could not differentiate the types of injuries sustained; back injuries occurred primarily while lifting, knee injuries while stepping, and shoulder injuries during pushing/pulling-related activities. CONCLUSIONS: Firefighter injuries are not just a fireground problem. Injury causation may be better understood by linking the injury location and type with motion patterns rather than job duties. This information could assist in developing general prevention strategies for the fire service.

Purification and characterization of creatine kinase, an estrogen-induced uterine protein (IP) from immature rats.

An estrogen-responsive translational product, the induced protein (IP) first described by Notides and Gorski (8), was obtained solely from the target organ, immature rat uterus, and purified to homogeneity in a procedure using two chromatography steps. The purified IP has a molecular weight of 49,000, and the isoelectric point is 5.2. Creatine kinase activity is associated with the homogeneous IP. There are some differences between the uterine enzyme and the creatine kinase BB isoenzyme, including differences in stability, and sensitivity to mercaptans. Estrogen-induced creatine kinase purified by this simple, reproducible method is a useful antigen for further studies on the translation and transcription processes involved in hormone-modulated synthesis.

Oligodeoxynucleotide base recognition by steroid hormone receptors.

Oligodeoxynucleotides covalently linked to cellulose were used as probes of the DNA-binding domains of mouse steroid holoreceptors. With uterine cytosol estrogen receptor (E2R) the relative binding order, in prior studies, was oligo(dG) greater than oligo(dT) greater than or equal to oligo(dC) much greater than oligo(dA) greater than oligo(dI). The binding reactions were salt-sensitive with an optimal KCl concentration of 0.1-0.2 M. There was no enhancement of binding by activation, either temperature- or salt-induced. In the present study, using the oligomer ligands at a lower concentration, oligo(dT) binding was greater than that to oligo(dC). Quantitative differences in oligodeoxynucleotide binding were elicited by a number of inhibitors. These differences are again seen by exposure of E2R to chaotropic salts such as SCN-, ClO-4 and NO3- as well as to putative modifiers of receptor amino acids, ie, iodoacetamide, 1,2 cyclohexanedione, and Rose Bengal. These results, and the quantitative differences following heat and purification, led to a designation of two types of subsites within the DNA-binding domain of uterine E2R. These are stable G sites, which interact with oligo(dG); and labile N sites, which bind to oligo(dT), oligo(dC) and oligo(dA). Stimulation of binding to N sites and stabilization of the holoreceptor was effected by histones H2A and H2B. However, the differential response to incubation at 37 degrees C was not altered by addition of H2B. Treatment of uterine E2R by limited proteolysis also eliminated the stimulatory response to H2B. The above data, as well as prior studies, indicate that steroid holoreceptors can discriminate between the structural features of deoxynucleotide bases and this recognition process can be modulated by accessory proteins.

Specificity of oligodeoxynucleotide binding of mouse uterine cytosol estradiol receptors.

The relative capacities of oligodeoxynucleotides, covalently linked to cellulose, to bind estradiol receptor complexes (E2R) of mouse uterine cytosol have been shown to follow the order oligo(dG) > oligo(dT) greater than or equal to oligo(dC) > oligo(dA). The E2R . oligo(dT)-cellulose-binding reaction is more sensitive to Cibacron blue F3GA than is E2R . oligo(dG)-cellulose or oligo(dC)-cellulose binding. Preformed E2R . oligo(dT)- or oligo(dC)-cellulose complexes are dissociated more readily by lower concentrations of KCl or Cibacron blue F3GA than is the E2R . oligo(dG)-cellulose complex. Preincubation of E2R at 37 degrees C results in a rapid loss of binding ability towards oligo(dT)- and oligo(dC)-cellulose, while up to 90% of the binding ability to oligo(dG)-cellulose is retained. On the basis of the differential sensitivities of E2R to temperature and the inhibition by Cibacron blue F3GA of the binding reaction, it is suggested that the polynucleotide-binding domain consists of two types of subsites, one of which has a higher affinity for oligo(dG) residues and the other of which recognizes oligo(dT), oligo(dC), and, to a lesser extent, oligo(dA).

Stimulation of oligonucleotide binding of estradiol receptor complexes by accessory proteins.

During purification of E2R using oligo(dT)-cellulose chromatography, a receptor accessory factor (RAF) was identified in the cytosol of mouse kidney. This factor stimulates the binding of purified E2R to oligo(dT)-, oligo(dC)-, and oligo(dA)-cellulose as well as to DNA cellulose. It is a heat-stable, trypsin-resistant protein with an apparent molecular weight of between 10 and 30,000 daltons. Although structurally unrelated, similar stimulation of oligonucleotide binding was seen with calf thymus histones and, to a lesser extent, egg white lysozyme. Individual histones, especially H2a, H2B, and H3, also facilitate rebinding of purified E2R to oligo(dT)-cellulose, while H1 is less effective. Furthermore, histones stabilize the holoreceptor during sedimentation at 4 degrees and 12 degrees C. The N- and C-terminal half molecules of H2b were generated by cyanogen bromide-mediated cleavage and the N-terminal half was found to duplicate the effects of the parent molecule, both in binding and holoreceptor stabilization. These data suggest that the in vivo binding of E2R to DNA can be modulated by accessory proteins of cytosol and nuclear origin.

Effect of Cibacron blue F3GA on oligonucleotide binding site of estradiol--receptor complexes of mouse uterine cytosol.

The binding of estradiol--receptor complexes of mouse uterine cytosol to oligodeoxynucleotide celluloses is inhibited by the sulfonated polyaromatic dye Cibacron blue F3GA. The dye does not have any effect on the estradiol binding site. Additon of the dye to preformed estradiol--receptor--oligo(dT)-cellulose complex results in the release of estradiol--receptor. The inhibition of binding is competitive with respect to oligo(dT)- or oligo(dA)-Celluloses, suggesting that the effect of the dye is directly on the polynucleotide binding site of the receptor. The observed inhibitory effect of Cibacron blue is not a simple electrostatic effect of polyanions because heparin and polyglutamic acid are much less effective. The selective inhibition by Cibacron blue suggests that the polynucleotide binding domain of estradiol--receptor possesses a special "supersecondary" structure [Stellwagen, E. (1977) Acc. Chem. Res. 10, 92--98].

Selective binding of mouse estradiol.receptor complexes to oligo(dT)-cellulose.

As a model for the nonspecific interaction of steroid receptors with DNA, the binding of estradiol.receptor complexes of mouse kidney and uterine cytosols to oligo(dT)-cellulose was studied in detail. A limited concentration range of monovalent cationic salts was required for optimal binding, regardless of prior activation of the receptor complexes or the oligomer ligand. Thermal activation of the receptor complexes did not facilitate binding. The reaction was selective for intracellular steroid hormone.receptor complexes, as extracellular proteins binding estradiol with low affinity (bovine serum albumin) or high affinity (mouse alpha-fetoprotein) were inactive. Both crude and partially purified kidney cytosol receptor complexes bound preferentially to oligo(dT)- and oligo(dC)-celluloses, rather than oligo(dA)-celluloses. These findings suggest that at least part of the nonspecific interaction of estradiol.receptor complexes with native DNA is through a salt-sensitive binding of the complex to pyrimidine-rich surfaces of the DNA.