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Biomedical subjects

R Silvennoinen

Publications and source records attributed to R Silvennoinen.

8 recordsLinked to original sources

Oral treatment of acute myeloid leukaemia with etoposide, thioguanine, and idarubicin (ETI) in elderly patients: a prospective randomised comparison with intravenous cytarabine, idarubicin, and thioguanine in the second and third treatment cycle.

A randomised multicentre study was conducted among patients over 65 yr of age with newly diagnosed acute myeloid leukaemia (AML) to compare oral treatment with etoposide 80 mg/m(2) and thioguanine 100 mg/m(2) twice daily on 5 d and idarubicin 15 mg/m(2) on 3 d (ETI) to a mainly i.v. combination of cytarabine 100 mg/m(2) twice daily on 5 d, idarubicin 12 mg/m(2) x 1, and thioguanine (TAI). Ninety-two patients were enrolled. Their median age was 72 yr, range 65-84 yr. Sixty-five patients had de novo AML, 21 AML subsequent to myelodysplastic syndrome, and six treatment-related AML. They received at first a 6-d i.v. treatment with cytarabine and idarubicin. After the first treatment, 68 patients were randomised to receive two cycles of ETI (n = 36) or TAI (n = 32) and thereafter maintenance with mercaptopurine and methotrexate. Of the 92 patients, 52 (57%) achieved remission at some stage. The median survival was 10 months. There were no significant differences between the patients randomised to ETI or TAI in the remission rate (67% vs. 72%), survival (12 months from randomisation in both arms), event-free survival or relapse rate. The patients randomised to receive ETI spent significantly fewer days at hospital during the two randomised cycles (20 vs. 41 d, P = 0.010), and they had fewer days with infusions, shorter neutropenias and thrombocytopenias and fewer and less severe infections. In conclusion, treatment with oral ETI resulted in a similar antileukaemic effect as obtained with mainly i.v. TAI, with less toxicity and reduced need for hospitalisation.

Administration, Oral↗

Optical inspection of punches: flat surfaces.

Optical inspection techniques for estimation of surface roughness and surface quality of flat punches, which are used in the pharmaceutical industry for tablet compression, were studied. It was observed that a simple specular reflection technique is useful for surface roughness assessment of flat punches. A diffractive element based sensor was used for the surface quality detection, such as mirror property or flatness, with the aid of image information of a test pattern. It was observed that a new punch may have a poorer surface quality than a used one.

Optics and Photonics↗

Pharmacokinetics of chlorambucil in patients with chronic lymphocytic leukaemia: comparison of different days, cycles and doses.

The effects of repeated treatment cycles and different doses on intraindividual variation in oral bioavailability of chlorambucil and its first, active, and more toxic metabolite, phenylacetic acid mustard, were studied. Chlorambucil and phenylacetic acid mustard concentrations were measured with HPLC on Day 1 and on Day 4 in 15 timed blood samples from 11 chronic lymphocytic leukaemia patients receiving chlorambucil therapy cycles. Bioavailability was evaluated also after the first chlorambucil doses of six consecutive treatment cycles repeated every 4 weeks with increasing chlorambucil doses starting with 0.8 mg/kg/4 days, and increased by 0.1 mg/kg/4 days cycle. Area under the concentration-time-curve (AUC) from t=0 to infinite was in average 3.2 hr* microg/ml for the first cycle, and decreased by 17% in four days (P<0.05). The mean distribution half-life of chlorambucil was 0.49 hr and the terminal elimination half-life 2.45 hr. The bioavailability of chlorambucil decreased further when 4-day treatment cycles were repeated. For the fifth cycle, dose-corrected AUC for the first 2 hr was 33% smaller than that for the first cycle (P for trend <0.01). Data suggest accelerated metabolism and elimination of chlorambucil and phenylacetic acid mustard, but reduced oral bioavailability of chlorambucil cannot be excluded. However, except for AUC, none of the pharmacokinetic parameters of chlorambucil changed significantly during the first 4-day treatment period. The maximal plasma concentration and AUC of phenylacetic acid mustard did not change significantly during repeated treatment cycles. According to this trial a dose adjustment of chlorambucil is not necessary during a short-term course, but may be necessary when treatment cycles are repeated. An average increase in the chlorambucil dose of 10% per cycle maintains similar plasma concentration of chlorambucil.

Administration, Oral↗

Optical surface roughness study of starch acetate compacts.

Optical surface roughness of starch acetate compacts was investigated by specular reflection of a laser beam as a function of angle of incidence. The intensity data was fitted using the model of Gaussian and Lorentzian curves to solve numerical values for optical surface roughness which was observed to be order of 1 microm with the present samples.

Starch↗

Detoxification of an alkylating drug, N,N-bis(2-chloroethyl)-p-aminophenylbutyric acid (chlorambucil), in human gastric juice and saliva.

N,N-Bis(2-chloroethyl)-p-aminophenylbutyric acid (chlorambucil, 1) is an orally administered drug widely used in the chemotherapy of chronic lymphocytic leukemia. It is converted in gastric juice into three stable metabolites, which were characterized as N,N-bis(2-hydroxyethyl)-p-aminophenylbutyric acid (4), N-(2-hydroxyethyl)-N-[2-(thiocyano)ethyl]-p-aminophenylbutyric+ ++ acid (5), and N,N-bis[2-(thiocyano)ethyl]-p-aminophenylbutyric acid (6). 4 is the product of chloroambucil hydrolysis, while 5 and 6 are results of the reaction of 1 with saliva-derived thiocyanate ion. The destabilizing effect of low gastric oxonium ion concentration on 1 is also demonstrated.

Administration, Oral↗