Microvascular research
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Microvascular research · May 2017
Randomized Controlled TrialReduced perfusion in systemic sclerosis digital ulcers (both fingertip and extensor) can be increased by topical application of glyceryl trinitrate.
In patients with systemic sclerosis (SSc), fingertip digital ulcers (DUs) are believed to be ischaemic, and extensor surface DUs a result of mechanical factors/microtrauma. Our aim was to assess blood flow response to topical glyceryl trinitrate (GTN) compared to placebo in SSc DUs, looking for differences in pathophysiology between fingertip and extensor lesions. ⋯ DUs (both fingertip and extensor) were responsive to topical GTN, with an increase in perfusion to the ischaemic DU centre. If both fingertip and extensor DUs have a (potentially reversible) ischaemic aetiology, this has important treatment implications.
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Microvascular research · Dec 2010
Randomized Controlled Trial Comparative StudyTissue viability imaging for assessment of pharmacologically induced vasodilation and vasoconstriction in human skin.
Tissue viability imaging (TIVI) is a novel polarization spectroscopy method for assessing dermal vascular viability. The purpose of the present study was to compare TIVI with laser Doppler flowmetry (LDF) for assessment of pharmacologically induced vasodilation and vasoconstriction in human skin. Eight individual skin sites on the backs of seven healthy volunteers were randomized to receive an intradermal injection of prostaglandin E2 (PGE2, 10(-6) to 10(-9)M), norepinephrine (NE, 10(-5) to 10(-7)M), or vehicle. ⋯ There was a modest though significant correlation between relative changes in vascular responses measured by the two methods (p<0.0001, r(2)=0.521). A Bland-Altman difference plot demonstrated significant underestimation of relative increase versus baseline measured by TIVI (r(2)=0.99, p<0.0001). We conclude that TIVI polarization spectroscopy is a sensitive method for measurement of NE-induced vascular responses but that it is less sensitive than LDF for measurement of the PGE2-induced reactions.
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Microvascular research · Jan 1996
Randomized Controlled Trial Comparative Study Clinical TrialSpontaneous laser doppler flux distribution in ischemic ulcers and the effect of prostanoids: a crossover study comparing the acute action of prostaglandin E1 and iloprost vs saline.
The flux distribution within ischemic ulcers and adjacent skin and its change by prostanoids was investigated using laser Doppler flux scanning. A prostanoid-induced increase in ulcer flux could be a rationale for the improved wound healing. In a single-blind prospective study 18 patients received prostaglandin E1 (PGE1) (333.3 ng/min.), iloprost (41.7 ng/min final dose), and 0.9% saline in a randomized order. ⋯ Simultaneously, LFS was not significantly changed when pretreatment values were compared with mean flux at 120 min: PGE1 2.13 +/- 0.27 vs 2.54 +/- 0.34, iloprost 2.03 +/- 0.26 vs 1.94 +/- 0.21, and saline 1.74 +/- 0.27 vs 1.92 +/- 0.30 (P > 0.05, each), respectively. The laser Doppler flux scanning technique might be a tool to study the distribution of laser Doppler flux within ischemic ulcers. This might be useful to study the physiological or pathophysiological control of flux within ischemic ulcers as well as possible therapeutic approaches.