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Stephen Carter

Publications and source records attributed to Stephen Carter.

11 recordsLinked to original sources

Detection of bleeding in injured femoral arteries with contrast-enhanced sonography.

OBJECTIVE: The purpose of this study was to investigate the feasibility of detecting acute arterial bleeding by means of contrast-enhanced sonography. METHODS: Puncture injury was produced transcutaneously with an 18-gauge needle in 26 femoral arteries (13 in the control group and 13 in the contrast-enhanced group) of rabbits. A sonographic contrast agent (Optison; Mallinckrodt Inc, St Louis, MO) was administered intravenously at a dose of 0.06 to 0.07 mL/kg. Sonography of the femoral arteries was performed before and after injury, both before and after injection of Optison, with B-mode imaging, color Doppler imaging, and pulse inversion harmonic imaging (PIHI). RESULTS: The specific location of active bleeding could not be visualized in B-mode and PIHI scans in the control group (no Optison injection). After administration of Optison, the bleeding site was visualized because of the increased echogenicity of the extravasated blood at the puncture site in both B-mode imaging and PIHI. In color Doppler images, bleeding sites were localized successfully in 84.6% of the cases in the presence of Optison and in 30.8% of the cases without Optison. Histologic examination (light microscopy) of the hematoma confirmed the presence of contrast agent microbubbles in the extravascular space surrounding the artery. CONCLUSIONS: Contrast-enhanced sonography may provide an effective method for detecting arterial bleeding.

Albumins↗

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Topical methyl nicotinate-induced skin vasodilation in diabetic neuropathy.

OBJECTIVE: To evaluate the vasodilation induced by topical application of methyl nicotinate (MN) and to compare it with the vasodilatory response to acetylcholine (ACh) and sodium nitroprusside (SNP) in healthy subjects and diabetic neuropathic patients. RESEARCH DESIGN AND METHODS: Ten diabetic patients with peripheral neuropathy (DN) and 10 age- and sex-matched healthy control subjects (C) were enrolled. The vasodilatory response to topical application of 1% MN and a placebo emulsion at the forearm and dorsum of the foot skin at 5, 15, 30, 60 and 120 min was measured using Laser Doppler Perfusion Imaging. The vasodilatory response to iontophoresis of 1% ACh and 1% SNP solutions was also evaluated. RESULTS: The maximal vasodilatory response to ACh, SNP and MN was similar at the forearm and foot level in the diabetic patients. In the control group, the responses to MN, ACh and SNP were similar on the forearm but in the foot, the MN vasodilatory response was higher when compared to the ACh and SNP responses. MN-related vasodilation was present 5 min after the application, reached its peak at 15-30 min and declined to pre-application levels 120 min afterward. CONCLUSIONS: Topical application of MN at the forearm and foot levels of diabetic neuropathic patients results in skin vasodilation that is comparable to the maximal vasodilation that can be induced by iontophoresis of ACh or SNP and lasts for less than 2 h. Further studies will be required to explore the potential of MN to increase blood flow and to prevent diabetic foot problems in clinical practice.

Acetylcholine↗