Microvascular research
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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 · Dec 2010
The evolving methodology to perform limb lymphoscintigraphy: from rest to exercise acquisition protocol.
In this technical report, prepared following the kind invitation of Professor D'Amore, we describe the evolution in the methodology of performing the limb lymphoscintigraphy. In details we described and compared the rest protocol with subcutaneous injection of the radio-colloids vs. the exercise intradermal injection protocol. The latter appears to be faster and easier to interpret, moreover allowing an adequate measurements of quantitative parameters of lymph drainage and distribution.
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Microvascular research · Dec 2010
Comparative StudyHyperaemic changes in forearm skin perfusion and RBC concentration after increasing occlusion times.
Tissue occlusion and the hyperaemic response upon reperfusion can be used as a tool to assess microvascular function in various vascular diseases. Currently, laser Doppler flowmetry (LDF) is applied most often to measure hyperaemic responses. In this study, we have applied tissue viability imaging (TiVi) and LDF to measure the change in red blood cell concentration and perfusion in the skin after occlusions of the forearm with increasing duration. ⋯ Furthermore, for both perfusion and RBC concentration, the maximum responses (perfusion: r(2)=0.59; RBC concentration: r(2)=0.78) and the recovery times (perfusion: r(2)=0.62; RBC concentration: r(2)=0.91) increase linearly with the duration of the occlusion. Maximum responses and recovery times were more reproducible for RBC concentration (as measured with TiVi) than for perfusion (as measured with LDF). These results show that perfusion and RBC concentration are related during post-occlusive hyperaemia and that TiVi can be used as a tool in the assessment of hyperaemic responses that has advantages in terms of reproducibility, sensitivity and ease of use.