Low level chromium (VI) inhalation effects on alveolar macrophages and immune functions in Wistar rats.

In inhalation chambers, 5-week-old male Wistar rats of the strain TNO-W-74 were continuously exposed to submicron aerosols of sodium dichromate in concentrations from 25 (low level) to 200 micrograms/m3 Cr (high level). Subacute exposure (28 days) to 25 and 50 micrograms/m3 Cr resulted in "activated" alveolar macrophages with stimulated phagocytic activities, and significantly elevated antibody responses to injected SRBC's. After subchronic (90 days) low level exposure there was a more pronounced effect on activation of the alveolar macrophages, with increased phagocytic activities. However, at high Cr (VI) exposure level (200 microgram/m3), inhibited phagocytic function of the alveolar macrophages was seen. In rats which were exposed to this chromium aerosol concentration for 42 days, the lung clearance of inert iron oxide was reduced significantly. The humoral immune system was still stimulated at subchronic low chromium aerosol concentrations of 100 micrograms/m3, but significantly depressed at 200 micrograms/m3 Cr. These results show that respiratory defence and immunologic functions were stimulated or inhibited depending on dose and time of chromium (VI) inhalation.

Influence of atropine upon ageing and reactivation of soman inhibited acetylcholinesterase from human erythrocytes. Preliminary communication.

From human blood concentrates erythrocyte "ghosts" were prepared. These and an enzyme solution, obtained by Triton X 100 treatment of the ghosts, were reacted with 1.2.2-trimethylpropyl-methyl-phosphonylfluoridate (soman). The rate constants of inhibition of the membrane bound and solubilized acetylcholinesterase (AChE) were determined at 3 degrees C, pH 8 and 9 to be 2 X 10(7) and 1.4 X 10(7) mol-1 min-1, respectively. Ageing of the phosphonylated AChE occurred with rate constants of 3.5 X 10(-2) (ghost bound) and 1.3 X 10(-2) (solubilized) min-1 at 3 degrees C, pH 8. 5 X 10(-4) mol/l atropine decreased the ageing rate by 50%. Reactivation of the non aged phosphonyl-AChE by several pyridinium oximes was enhanced by atropine with the ghost-bound enzyme; the reactivation of the phosphonylated solubilized enzyme, however, was not affected by atropine.

Long-term evaluation of naproxen suspension in juvenile chronic arthritis.

Twenty-six children suffering from juvenile chronic arthritis were entered into a 6-month open evaluation of naproxen suspension. Sixteen patients completed 6-months' treatment, 6 were lost to follow-up and 4 dropped out, 2 because of side-effects (rash, and burning on swallowing the formulation), 1 for lack of efficacy and 1 because of no further need of treatment. Pain severity scores were significantly reduced from admission levels at all monthly follow-up visits and significant overall improvement since the last visit was noted up to third month of treatment, as assessed by doctor and parent/patient. Transient indigestion was reported by 2 patients. No clinically significant trends were noted in any of the laboratory investigations carried out. The results add to the accumulation of data on the use of naproxen in children and underline its long-term efficacy and tolerance.