Search PubMed⌕ Search

Biomedical subjects

J Kristinsson

Publications and source records attributed to J Kristinsson.

38 records · Page 3Linked to original sources

Impact of morning versus evening schedule for oral methotrexate and 6-mercaptopurine on relapse risk for children with acute lymphoblastic leukemia. Nordic Society for Pediatric Hematology and Oncology (NOPHO).

PURPOSE: To study the risk of non-B-cell acute lymphoblastic leukemia (ALL) relapse in relation to the routines of administration of oral methotrexate (MTX) and 6-mercaptopurine (6MP) and to the erythrocyte (E) levels of the intracellular cytotoxic metabolites, that is, MTX polyglutamates and 6-thioguanine nucleotides (E-MTX and E-6TGN). PATIENTS AND METHODS: E-MTX and E-6TGN levels were measured at least three times (medians, eight and nine) in 294 children with non-B-cell ALL during oral MTX and 6MP therapy. For each patient, we registered (a) the individual circadian schedule of drug administration and (b) the coadministration of food, and (c) calculated a mean (m) of all E-MTX and E-6TGN measurements and (d) the product of mE-MTX and mE-6TGN (mE-MTX*6TGN), due to their synergistic action. RESULTS: A total of 42 patients were on a morning schedule, 219 were on an evening schedule, and 33 had miscellaneous routines. A total of 149 patients took the drugs with meals, 106 took the drugs between meals, and 39 had varying routines. With a median follow-up of 78 months, ALL has recurred in 66 patients. The patients on an evening schedule had a superior outcome [probability of event-free survival (pEFS) = 0.82 +/- 0.03 vs. 0.57 +/- 0.08; p = 0.0002], whereas the coadministration of food did not significantly influence outcome. Patients with a mE-MTX*6TGN < 813 [product of median mE-MTX (4.7 nmol/mmol Hb) and mE-6TGN (173 nmol/mmol Hb)] had an inferior outcome (pEFS = 0.70 +/- 0.04 vs. 0.85 +/- 0.03; p = 0.003), even if only patients on an evening schedule were analyzed. Thus, 109 patients on the MTX/6MP evening schedule with an mE-MTX*6TGN < or = 813 (nmol/mmol Hb)2 had a pEFS of 0.89 +/- 0.03 and a probability of continuous hematopoietic remission of 0.91 +/- 0.03. CONCLUSIONS: An evening schedule should be recommended for oral MTX/6MP maintenance therapy. The value of individual dose adjustments by E-MTX and E-6TGN remains to be determined in prospective randomized trials.

Administration, Oral↗

Copper, ceruloplasmin and superoxide dismutase in patients with Alzheimer's disease . a case-control study.

The copper-containing enzyme superoxide dismutase (SOD) is a key enzyme in suppressing the amounts of superoxide anion radicals. Ceruloplasmin, the copper-transporting protein in plasma, also possesses an important redox capacity. In this study the levels of copper and ceruloplasmin as well as SOD-activity and ceruloplasmin oxidative activity were analyzed in order to throw some light on possible defects in copper mechanisms in patients diagnosed with Alzheimer's disease (AD). The study included 44 patients with AD and their healthy age- and gender-matched controls. No difference of significance was seen when comparing the copper or ceruloplasmin concentration in plasma of AD patients to that of their paired controls. The SOD activity in red blood cells was significantly lower in the patients than in their controls (p = 0.019). The ceruloplasmin oxidative activity in plasma of Alzheimer's patients was greatly reduced as compared to that of age- and gender-matched controls and the difference was highly significant (p = 0.0005). Ceruloplasmin activity and SOD activity were not found to be intrinsically correlated. It was postulated that reduced oxidative activity of ceruloplasmin in plasma might be either a cause or a consequence of AD and that reduced SOD activity might further add to the oxidative disturbances in AD due to defective ceruloplasmin activity.

Aged↗