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Background: Evidence-based physical employment standards are vital for recruiting, training and maintaining the operational effectiveness of personnel in physically demanding occupations. Aims: (i) Develop criterion tests for in-service physical assessment, which simulate the role-related physical demands of UK fire and rescue service (UK FRS) personnel. (ii) Develop practical physical selection tests for FRS applicants. (iii) Evaluate the validity of the selection tests to predict criterion test performance. Methods: Stage 1: we conducted a physical demands analysis involving seven workshops and an expert panel to document the key physical tasks required of UK FRS personnel and to develop 'criterion' and 'selection' tests. Stage 2: we measured the performance of 137 trainee and 50 trained UK FRS personnel on selection, criterion and 'field' measures of aerobic power, strength and body size. Statistical models were developed to predict criterion test performance. Stage 3: matter experts derived minimum performance standards. Results: We developed single person simulations of the key physical tasks required of UK FRS personnel as criterion and selection tests (rural fire, domestic fire, ladder lift, ladder extension, ladder climb, pump assembly, enclosed space search). Selection tests were marginally stronger predictors of criterion test performance (r = 0.88-0.94, 95% Limits of Agreement [LoA] 7.6-14.0%) than field test scores (r = 0.84-0.94, 95% LoA 8.0-19.8%) and offered greater face and content validity and more practical implementation. Conclusions: This study outlines the development of role-related, gender-free physical employment tests for the UK FRS, which conform to equal opportunities law. [ABSTRACT FROM AUTHOR]

Dietary copper deficiency is known to affect metabolism of neutral lipids, phospholipids, prostaglandins, Cu-Zn superoxide dismutase and crosslinks of connective tissues. To investigate the effects of copper deficiency on lung ultrastructure, dietary copper deficiency was induced by feeding female guinea-pigs a diet marginally deficient in copper (0.8 microgram Cu/g diet) and compared with those fed a diet sufficient in copper (5.8 micrograms Cu/g diet). After 10 months on the diets, at age 340 days, animals were killed and the lungs removed and processed for electron microscopy to study the changes in cellular morphology. Type II epithelial cells in lung alveoli of copper deficient guinea-pigs, revealed larger lamellar bodies, in comparison with lungs of copper supplemented guinea-pigs (2.1 +/- 0.67 vs 1.35 +/- 0.47 microns). Fusion of lamellar bodies had occurred. Lipid droplets were found in the cytoplasm, which, in 20% of these cells, was as a single large lipid droplet approximately 10 microns in diameter. Features of the bronchiolar Clara cells in response to copper deficiency included the formation of packed tubular structures, 50 nm diameter. These tubules resembled smooth endoplasmic reticulums, and occupied 35.6% of the cell profiles by stereologic analysis. Clara cells from copper deficient guinea-pigs also contained many uniform, hexagonal crystal structures, in greater concentration than reported previously. Residual macrophages and monocytes observed in the capillaries contained giant lipid inclusions, which were stained by Sudan Black, indicative of neutral lipids. In this study, we suggest that perturbations in protein, lipid and membrane metabolism resulting from dietary copper deficiency in the guinea-pig may have altered the synthesis or degradation of lipid and protein components of lung cells or prevented their normal secretion into the airways or extracellular spaces.

Dietary copper-deficient guinea pig dams (0.8 microgram Cu/g diet) were administered oxytocin to induce delivery of pups, whereas dietary copper-sufficient guinea pig dams (5.8 micrograms Cu/g diet) had uneventful deliveries with 79% surviving pups. The copper-deficient dams carried the fully-formed fetuses to term but did not go into labor unless 0.5 to 6.2 U oxytocin was administered (i.m.). Birth of live pups from copper-deficient dams increased from 28% overall, to 50% if oxytocin was administered in a timely manner. Many pups died of internal hemorrhages probably the result of defective connective tissue crosslinks requiring copper as a co-factor for lysyl oxidase activity. Dietary copper deficiency may be a factor in depressed parturition in the copper-deficient guinea pig dam that responds to administration of exogenous oxytocin for delivery of pups.

Elastic fibers comprise elastin and other proteins termed as elastin-associated proteins. The nature of association between the elastin and elastin-associated-protein is not known. We have isolated elastic fibers from 5-month-old porcine aorta and lung parenchyma using urea, dithiothreitol and 1% sodium dodecyl sulfate at 55 degrees C. Lysyl-derived crosslinks were stabilized by sodium borohydride reduction. The methionine residues and associated peptides were decreased by CNBr treatment. Limited proteolysis of elastic fibers obtained by this procedure by trypsin (TPCK) and chymotrypsin (TLCK), removed 3% and 11% of the elastic fibers from aorta and lung, respectively. Limited elastase digestion solubilized a further 12 to 14% of the elastic fiber from aorta and lung samples, respectively. The insoluble residue remaining after elastase digestion had amino acid composition similar to alkali extracted elastin and to tropoelastin. The material solubilized by chymotrypsin and trypsin contained lysinonorleucine, whereas desmosine crosslinks were present only in the elastase digests. Aorta and lung elastic fibers differ in their structures as indicated by quantitative differences in limited proteolysis. These results strongly indicate that elastin and elastin-associated proteins interact strongly through lysyl-derived crosslinks.

Lung elastic fiber was isolated from anatomically defined porcine parenchymal tissue. Constituent microfibrillar acidic structural glycoproteins (external and meso) were obtained by mild dissociative quantitative procedures, leaving the elastin-rich fraction as the insoluble residue. The presumptive cross-link lysylnorleucine was identified in both of the highly aggregated acidic structural glycoprotein fractions. The external-acidic structural glycoproteins require dithiothreitol but not sodium dodecyl sulfate for solubility. Both sodium dodecyl sulfate and dithiothreitol at 55 degrees C are required to release meso-acidic structural glycoproteins from the elastic fiber. On the basis of physical characteristics, I propose a new fraction from elastic fiber, the meso-acidic structural glycoprotein. The meso-acidic structural glycoproteins may have been in longest and closest contact with the elastin core of the elastic fiber. Alkali-soluble peptides from the elastin-rich fraction contained desmosine and high concentrations of hydroxyproline, polar amino acids and lysylnorleucine. The cross-link, lysylnorleucine, may be evidence of covalent bonding of glycoprotein to elastin, explaining my inability to obtain the biopolymer elastin with the composition of tropoelastin corrected for the desmosine-lysine content.

Dialysis membranes used for simultaneous dialysis-concentration required pretreatment to remove uv-absorbing compounds leached from the membranes and to reduce the absorption of protein to the membranes. This was accomplished with sodium carbonate and ethanol or with "sulfur-removal solutions." Protein determinations were made with a micro-Bradford protein reaction and with uv absorbance at 280 nm. Soluble membrane components contributed to aberrant uv spectra and altered the ratio of 280/260-nm absorbance. Simultaneous dialysis and concentration in the micro protein dialyzer-concentrator apparatus, combining aspects of thin-layer dialysis and ultrafiltration, resulted in rapid removal of salts from the protein solutions. Prior treatment of membranes reduced uncertainties in retentate recoveries, eliminated uv-absorbing components of membranes, and improved recoveries of protein.

Methionine, an essential amino acid, and cysteine are the major sulfur-containing amino acids in the body and both are thought to be synthesized predominantly in plants and micro-organisms. Methylsulfonylmethane (MSM) is a natural constituent of the environment in which it is found in plants, in milk and urine of both bovines and humans, is a normal oxidation product of dimethyl sulfoxide (DMSO) also in the natural environment and may be part of the natural global sulfur cycle. To determine whether sulfur from methylsulfonylmethane (MSM) is incorporated into sulfur amino acids, I fed 35S-MSM to guinea pigs. 35S was incorporated into peptidyl methionine and cysteine of guinea pig serum proteins. The specific activity of 35S-methionine was 30% greater than for 35S-cysteine, suggesting a precursor-product relationship. Total specific activity of serum proteins was increased by only 30% with a 100% increase of administered 35S-MSM, suggesting a limiting step in synthesis. Approximately 1% of the radioactivity was recovered in serum proteins, none in the feces and most was excreted in the urine. Microorganisms of intestinal lumen may be responsible for the incorporation of the 35S of MSM into sulfur amino acids. MSM may provide a source of sulfur for essential animal methionine by mechanisms not yet elucidated in either animals or micro-organisms.