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D S Irwin

Publications and source records attributed to D S Irwin.

6 recordsLinked to original sources
PubMed1987

"Matrigenin" activity from bovine bone--I. Partial purification of activity.

1. Bovine bone contains an extractable activity which stimulated the synthesis of glycosaminoglycans by bovine synovial, human synovial and mouse 3T3 fibroblastic cells in culture. Human cells were used to develop an assay for purification of the stimulatory activity ("matrigenin" activity) from bovine bone. 2. Partial purification of "matrigenin" activity was achieved by precipitation of the EDTA extract at pH 3.5 and Sepharose CL-6B chromatography in 4 M guanidinium HCl. Dissociative conditions were necessary to prevent aggregation. 3. On SDS-polyacrylamide gel electrophoresis the activity ran with a mobility equivalent to a Mr = 27,500 and could be recovered from the SDS gels.

Animals↗
PubMedDate not supplied

Bioavailability of chlorothiazide from 50, 100, and 250 MG solution doses.

The bioavailability of chlorothiazide was examined following single oral solution doses to eight healthy male volunteers. Drug was administered in 250 ml of water after overnight fast. Bioavailability was determined by measuring 72 h urinary recovery of unchanged drug. Mean urinary recovery from 50, 100, and 250 mg doses was, respectively, 28.3, 47.0 and 83.3 mg, representing 56.4, 47.0, and 33.3 per cent of the administered dose. The correlation coefficient between dose size and percentage recovery was -0.662. These results add support to previous suggestions that the absorption of chlorothiazide from the gastrointestinal tract is saturable, and that the availability of chlorothiazide may be similar to that of hydrochlorothiazide when these compounds are administered in the same dosage range.

Adult↗
PubMedDate not supplied

Absorption of theophylline from enteric coated and sustained release formulations in fasted and non-fasted subjects.

The influence of prior food ingestion, and also of varying fluid volumes, on plasma theophylline levels was examined following single oral doses of two sustained-release formulations, Theobid (260 mg) and Theo-Dur (200 mg) and one partially enteric-coated formulation, Choledyl (128 mg), to 9 healthy volunteers. Prior food ingestion tended to delay the absorption of theophylline from all formulations to a small extent. This effect was observed only at early sampling times, and plasma drug profiles were similar for all treatments within a particular formulation. Theobid and Theo-Dur gave rise to plasma profiles that were characteristic of sustained-release formulations, with mean Cmax values of 5.5-5.7 micrograms ml-1 (Theobid) and 2.8-3.2 micrograms ml-1 (Theo-Dur) occurring at 5.8-9.1 h after dosing. Choledyl gave rise to a longer absorption lag time than the other formulations but was subsequently absorbed at a faster rate yielding mean Cmax values of 3.2-3.5 micrograms ml-1 at 2.8-4.1 h. The intersubject variability in theophylline plasma levels, and also in most pharmacokinetic parameter values, was generally less following Theo-Dur compared to the other formulations.

Adult↗