High-dose AZA therapy in a triple-drug regimen, monitored by 6-TGN, will keep myelotoxicity within acceptable limits with the benefit of a reduction in acute rejection episodes.

No abstract

CYP2D6 activity does not have a major impact on the disposition of diltiazem. In contrast, desacetyl diltiazem and N-demethyldesacetyl diltiazem are markedly accumulated in individuals expressing a deficient CYP2D6 phenotype. Because these metabolites exhibit pharmacologic properties of possible importance, individual CYP2D6 activity might be an aspect to consider in the clinical use of diltiazem.

An endogenous cytoplasmic protein, metallothionein (MT) apparently gave rise to radioresistance in 2 different cell lines. A dose reduction factor of 1.9 was achieved in MT-containing cells. MT accounted for a 3-4 fold increase of total sulfhydryl groups in the resistant cell strains, compared to the non-resistant lines from which they were derived. The protein is rich in cysteine (30%), an amino acid known to give radioprotection when administered exogenously. Glutathione levels and cell-cycle phase distribution showed no marked difference between resistant and corresponding non-resistant cells.

Cyclosporin A (CyA) and azathioprine (Aza) were compared with respect to renal side effects in an open controlled, randomized study of patients with rheumatoid arthritis. Twelve patients were treated with CyA (mean dose 7.8 +/- 1.2 mg/kg/day) and 12 with azathioprine for 26 weeks. All patients also received prednisolone 5 mg/day. The patients had normal serum creatinine (less than 120 mumoles/liter) and protein-free urine before the trial. CyA increased serum creatinine in nine out of the 11 patients followed for 26 weeks, the mean increase was approximately 50%. Creatinine clearance was reduced by 31%. Mean arterial pressure (MAP) and serum potassium were significantly increased by CyA. Urinary beta 2-microglobulin excretion was significantly increased by CyA, in five of the patients more than ten times. Urinary kallikrein excretion was reduced by more than 50% and urinary albumin excretion was doubled. All these parameters remained normal and unchanged in the azathioprine group. CyA was withdrawn in seven patients after 26 weeks. Urinary beta 2-microglobulin was still increased by 85% nine months after CyA treatment. The other parameters were gradually normalized after three to nine months except for one patient who developed renal failure. Urinary beta 2-microglobulin excretion was a very sensitive parameter for renal tubular damage in this study.