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Biomedical subjects

A Wirsen

Publications and source records attributed to A Wirsen.

2 recordsLinked to original sources

Micro and nano-structured surfaces.

The study of cell reaction to micro and nanotopography is dependent on the method of manufacture available. Several methods of manufacture have been developed: polymer demixing, embossing and photolithography. Surfaces obtained with these different techniques, having micro and/or nanodomains, have been studied toward the same type of cells, i.e. human endothelial cells (HGTFN) and mouse fibroblasts (3T3). Polymer demixing of polystyrene (PS) and poly(4-bromostyrene) (PBrS) producing nanometrically islands of 18, 45 and 100 nm height, polycarbonate (PC) and polycaprolactone (PCL) grooved with grooves 450 nm wide and 190 high, the natural polysaccharide hyaluronic acid (Hyal) and its sulfated derivative (HyalS) photoimmobilized on silanized glass as grooves 250 nm high and 100, 50, 25 or 10 microm wide have been obtained. The morphology and polarization of the cells has been studied by optical microscopy and scanning electron microscopy. Cells respond in different way to the topography of the materials, but the surface chemistry is dominant in inducing different cell behavior.

Journal Article↗

Prizidilol, a combined vasodilatory and beta-adrenoceptor blocking drug, in primary hypertension. A long-term efficacy, tolerance and pharmacokinetic study.

After an initial placebo period of four weeks 24 patients with primary hypertension were treated with prizidilol, a hydrazinopyridazine derivative with combined vasodilator and non-selective beta-adrenoceptor blocking actions, for a dose titration period of 14 weeks. Prizidilol 200 to 800 mg was given once daily to achieve a target supine diastolic blood pressure (BP) less than 90 mmHg. Supine and standing BP recorded 24-27 h after drug intake decreased from 172 +/- 17/106 +/- 6 mmHg (mean +/- SD) and 167 +/- 18/111 +/- 8 mmHg, respectively, after placebo to 159 +/- 16/99 +/- 8 and 154 +/- 18/101 +/- 9 mmHg after active treatment for six weeks (mean dose 447 mg), and to 154 +/- 16/97 +/- 7 and 148 +/- 14/97 +/- 7 mmHg after treatment for 14 weeks (mean dose 687 mg/day). A slight reduction in HR was seen after treatment for six weeks and in plasma renin activity and urinary methoxycatecholamine excretion after treatment for 14 weeks. A sustained decrease in BP was observed for 10 h after prizidilol 800 mg (n = 9), with a maximum antihypertensive effect (mean reduction in supine BP 33/18 mmHg) 2.5 h after dosing, which coincided with the mean peak plasma concentration. The plasma elimination half-life of the drug was 3.9 h (range 2.0-8.9 h). Changing to a twice daily regimen in 17 patients (mean daily dose 748 mg at six months) did not produce any further reduction in the BP (recorded 12-15 h after dosing) as compared to the once daily regimen at 14 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylation↗