Induction of glutathione-dependent formaldehyde dehydrogenase activity in Escherichia coli and Hemophilus influenza.

We have examined the induction of glutathione-dependent formaldehyde dehydrogenase (GS-FDH) activity in Escherichia coli and Hemophilus influenza. Formaldehyde was found to induce enzyme activity in both E. coli and H. influenza at concentrations between 0.6 and 20 ppm. Higher formaldehyde concentrations were toxic. Methanol concentrations up to 20% (200,000 ppm) and sodium formate concentrations up to 2% (20,000 ppm) gave negligible amounts of induction. The basic mechanism of induction was probed by inducing GS-FDH activity in the presence of rifampicin to inhibit RNA synthesis or chloramphenicol to inhibit protein synthesis. Both reagents inhibited GS-FDH induction, demonstrating that regulation occurs at the level of transcription. These results indicate that at least one function of GS-FDH in Gram-negative bacteria is to detoxify exogenous formaldehyde encountered in their environment and that GS-FDH inducibility may be a common feature of Gram-negative bacteria.

Adrenocortical suppression in workers employed in manufacturing synthetic glucocorticosteroids: solutions to a problem.

Earlier studies showed gross adrenocortical suppression in three workers employed in manufacturing synthetic glucocorticoids. A further nine had either recognisable abnormalities of their responses to tetracosactrin or evidence of chronic skin contact with glucocorticoids. By 1978 the mean morning cortisol concentration of 20 workers employed in active steroid processes was 235 nmol/1 +/- 28.6 (8.5 microgram/ml +/- 1.04), which was significantly lower than the value of 428 nmol/l +/- 37.7 (15.5 microgram/ml +/- 1.40) obtained in a control group of 19 men (p less than 0.005). The mean morning cortisol of workers employed in processing steroids believed to be physiologically inactive, 306 nmol/l +/- 22.4 (11.1 microgram/ml +/- 0.81), was also significantly lower than this control group (0.01 greater than p greater than 0.005). Improvement of protection for workers together with operational and plant changes resulted in a significant rise in the mean morning cortisol values of workers until, in 1979, men employed in all steroid processes had concentrations that did not differ from those of a control group.