Self-reported musculoskeletal symptoms and observed risk factors in bareroot tree nurseries.

A cross-sectional study of jobs at four bareroot reforestation tree nurseries in Washington and Oregon investigated the prevalence of musculoskeletal symptoms and potential work-related musculoskeletal disorders (WMSDs), and analyzed their association with physical and psychosocial risk factors of the jobs. Questionnaires were used to assess symptoms and psychosocial factors. Direct observational work sampling was utilized to estimate physical risk factors. The response rate for the questionnaires was 41% (203 subjects), of which 72% reported recurring symptoms in the past year. The most common body region was the wrist/hand (42%). Pain was the most commonly reported symptom. Forty-one percent of the subjects had at least one potential WMSD, the hand region having the greatest number of cases (n = 51). The average age of those with and without potential WMSDs did not significantly differ; however, tenure at the nursery (p < 0.03) did. Being female (OR = 7.37; 95% CI = 2.75, 19.7,) high job satisfaction (OR = 0.32; 95% CI = 0.15, 0.72), and having a second job (OR = 3.76; 95% CI = 1.12, 12.57) were significantly associated with potential WMSDs. No significant difference in WMSD prevalence was found between the field and packing shed areas of the nurseries (p = 0.88). Pinch gripping was observed 24% of the time in the shed and 8% of the time in the field. Torso flexion was observed more often in the field than the shed (38% vs. 18% of the time). This study found that both physical and psychosocial factors associated with WMSDs are present in bareroot trees nurseries.

Chemical studies on protease A of Bitis arietans (puff adder) venom.

Protease A of Bitis arietans venom is probably a metalloprotease, since it is inhibited by o-phenanthroline and contains 0.77 moles of zinc per mole protein. The enzyme comprises 213 amino acids, including 9 methionine residues and one free sulphydryl group. It contains one polypeptide chain, which is terminated at the carboxyl end by serine. The amino terminal sequence of protease A is: Arg-Ser-Ser-Asp-Pro-Asn-Lys-Tyr-Phe-Asn-Val-Ile-Val-Val-Val-Asp-Asn-Arg- Met-Val-Asn-Tyr-Tyr-Lys-Gly-Glu-Leu-Asn-Lys-Ile-Thr-. Despite difficulties with 'insoluble peptide core' formation, a number of peptides were purified from peptic and tryptic digests of S-derivatized protease A.