Further evidence to support disconjugate eye torsion as a predictor of space motion sickness.

Disconjugate eye torsion in hypo- and hypergravity of parabolic flight was examined in four former astronauts and four previously tested ex-astronauts to replicate an earlier study and to further test the asymmetry hypothesis of otolith function. Results in the new subjects supported the asymmetry hypothesis and confirmed previous findings that those with low scores of torsional disconjugacy on the KC-135 did not suffer space motion sickness in their prior Shuttle missions while those with high scores did. Tilting subjects with high disconjugacy scores slightly to one side and the other failed to find a position that decreased disconjugacy in hypergravity, leading to the conclusion that a simple planar asymmetry about the y-axis was probably not the cause of the observed torsional differences in the two eyes. Disconjugacy increased at 0 G with increasing parabolas, much more so in subjects who had suffered SMS. Because of this, 10 to 20 parabolas were deemed to be a more certain discriminator than a fewer number.     

FS13.5Occupational contact dermatitis: printer worker's viewpoints

Introduction:  Occupational contact dermatitis (OCD) is very common in the printing industry due to contact with chemicals, paper, and wet work. It can be avoided by adequate protective measures, but the effectiveness of intervention depends heavily on the employer's and employee's awareness of this health risk.
Objectives:  The study aimed to collect information on the knowledge, attitudes and beliefs of print workers about the risk of OCD and methods of prevention.
Methods:  A series of focus groups were held with print workers, health and safety officers and managers to discuss their awareness of dermal risk factors, risk behaviour at work, attitudes to health and safety and options on possible preventive measures. A number of companies were also visited to observe, overtly and covertly, the normal work practices.
Results:  OCD was not perceived to be either a major problem or a health and safety priority. There was general agreement about the processes and work practices that could cause skin problems. However, work practices varied considerably and did not always reflect this awareness. There was general concern about the type and availability of personal protective equipment, especially gloves and after‐work skin cream. The provision of an occupational health service was generally felt to be inadequate, and no company had a policy in place that specifically addressed skin care.
Conclusions:  These findings highlight the urgency to intensify health and safety education on skin care within the printing industry. Recommendations were developed for the evaluation of a series of risk reduction strategies.     

Evaluation of kemptide, a synthetic serine-containing heptapeptide, as a phosphate acceptor for the estimation of cyclic AMP-dependent protein kinase activity in respiratory tissues

In the search for a phosphate acceptor to estimate cyclic AMP-dependent protein kinase (A-kinase) activity in respiratory tissues devoid of the disadvantages inherent with the use of histones, we compared and contrasted a conventional substrate, histone IIa, with that of a novel heptapeptide phosphate acceptor, Kemptide (Kemp et al., J Biol Chem 252: 4888-4894, 1977). The specific activities of soluble A-kinase isolated from guinea-pig lung parenchyma and from bovine tracheal smooth muscle were significantly (12-16-fold) greater when Kemptide was used as substrate when compared to histone IIa. Moreover, studies with a specific inhibitor of A-kinase demonstrated that whilst the cyclic AMP-stimulated phosphorylation of Kemptide was catalysed exclusively by A-kinase, only approximately 89% of the phosphate incorporated into histone IIa was attributed to the activity of this enzyme. The activation constant (Kact) of cyclic AMP for A-kinase was estimated to be 1.5 microM when Kemptide was used as substrate, 25-fold higher than that obtained using histone IIa (60 nM) under identical conditions. In a complementary series of experiments it was found that both the basal and isoprenaline-stimulated A-kinase activity ratios were significantly higher when histone IIa was used as substrate when compared with that obtained using Kemptide. Elevating the ionic strength of the homogenization buffer or assay cocktail with NaCl produced a reversible (following dialysis), concentration-dependent, mixed uncompetitive, inhibition of cyclic AMP-stimulated histone phosphorylation; phosphokemptide formation was unaffected. The ability of salt to inhibit A-kinase activity also affected the elution profile of A-kinase isoenzymes following their separation by DEAE-cellulose chromatography. With histone IIa as substrate the Type I:Type II isoenzyme ratio in guinea-pig lung and in bovine tracheal smooth muscle was 9:91 and 35:65, respectively. Changing the phosphate acceptor to Kemptide reduced these respective ratios to 5:95 and 29:71. Although the effect on the isoenzyme ratio was small, the specific activities of the two isoenzymes isolated from both tissues were markedly attentuated by ca. 9% (Type I) and 36% (Type II). It is concluded that Kemptide is without many of the disadvantages inherent with histone IIa and is, thus, a preferable phosphate acceptor for estimating soluble A-kinase activity and determining the isoenzyme ratio in guinea-pig lung and in bovine tracheal smooth muscle.     

Reproducibility of lateral spine scans using dual energy X-ray absorptiometry

Summary Reproducibility of lateral spine dual energy X-ray absorptiometry (LAT DEXA) scans using a Lunar DPX-L scanner was assessed in a cadaveric phantom and in patients. One hundred phantom measurements over 7 months demonstrated a longitudinal stability of 1.7% (coefficient of variation, CV). Additional scans were performed with the phantom rotated by up to 20° in each of the three orthogonal planes to assess the effects of variable patient positioning. Horizontal and vertical rotation of the spine had little effect on the estimated bone mineral density (BMD), however, axial rotation of greater than 8° led to errors in the BMD measurement. One hundred consecutive patients had two lateral scans performed within 1 month. BMD (range 0.10–1.6 g/cm²) was determined for each scan by one operator. Significant overlap from ribs and pelvis was often seen with L2 and L4 vertebrae but one vertebra (L3) could be measured in every case. Intraoperator and interoperator variability was assessed by three experienced operators, each analyzing 10 patients' scans on five separate occasions, and was found to be less than 1.1% for a single vertebra. BMD estimation of vertebral bodies and midslices by lateral DEXA scans (CV% of 3.8% and 4.6%) have a 95% confidence interval of 0.074 g/cm² and 0.096 g/cm², respectively for two vertebrae. This variability is due mainly to axial rotation, with operator variability, horizontal rotation, and vertical rotation having little effect on BMD estimation.