Effects of quercetin on exercise performance, physical activity and blood supply in a novel model of sustained hind-limb ischaemia.

BACKGROUND: There are currently few effective drugs to treat the leg symptoms of peripheral arterial disease (PAD). Previous studies have suggested that the nutraceutical, quercetin, can improve exercise performance and reduce pain sensitivity in healthy mice and improve blood supply in a rodent model of acute hind-limb ischaemia. These models may not be relevant to people with PAD. The aim of this study was to examine the effect of quercetin on exercise performance, physical activity and blood supply in a novel mouse model of sustained hind-limb ischaemia. METHODS: Hind-limb ischaemia was induced in 6-month-old male apolipoprotein E-deficient mice using a novel two-stage surgical procedure. Five days after induction of ischaemia, mice were allocated to commence dietary quercetin or a control diet for 4 weeks. The primary outcome was exercise performance evaluated using a treadmill test. Other outcomes included physical activity, estimated by an open field test, and hind-limb blood supply, assessed by laser Doppler monitoring. RESULTS: A sustained reduction in relative limb blood supply (P < 0.001) was achieved consistently in all 48 mice before allocation to a control (n = 24) or quercetin (n = 24) diet. Quercetin did not improve exercise performance (P = 0.785), physical activity (P = 0.151) or relative limb blood supply (P = 0.954) over the 4-week assessment period. CONCLUSION: These data suggest that quercetin does not improve exercise performance, physical activity or limb blood supply in mice with sustained hind-limb ischaemia, and therefore is unlikely be an effective treatment for PAD.

Plasma Low-density Lipoprotein Receptor-related Protein 1 Concentration is not Associated with Human Abdominal Aortic Aneurysm Presence.

OBJECTIVE/BACKGROUND: Recent genetic data suggest that a polymorphism of LRP1 is an independent risk factor for abdominal aortic aneurysm (AAA). The aims of this study were to assess whether plasma and aortic concentrations of low-density lipoprotein receptor-related protein 1 (LRP1) are associated with AAA, and to investigate the possible relevance of LRP1 to AAA pathophysiology. METHODS: Three analyses were conducted. First, plasma LRP1 concentrations were measured in community-dwelling men with and without AAA (n = 189 and n = 309, respectively) using enzyme-linked immunosorbent assay. Second, Western blotting analyses were employed to compare the expression of LRP1 protein in aortic biopsies collected from patients with AAA and nonaneurysmal postmortem donors (n = 6/group). Finally, the effect of in vitro LRP1 blockade on matrix metalloprotease 9 (MMP9) clearance by vascular smooth muscle cells was assessed by zymography. RESULTS: Plasma LRP1 concentrations did not differ between groups of men with and without AAA (median concentration 4.56 µg/mL [interquartile range {IQR} (3.39-5.96)] and 4.43 µg/mL [IQR 3.44-5.84], respectively; p = .48), and were not associated with AAA after adjusting for other risk factors (odds ratio 1.10 [95% confidence interval: 0.91-1.32]; p = 0.35). In contrast, LRP1 expression was approximately 3.4-fold lower in aortic biopsies recovered from patients with AAA compared with controls (median [IQR] expression 1.72 [0.94-3.14] and 5.91 [4.63-6.94] relative density units, respectively; p < .01). In vitro LRP1 blockade significantly reduced the ability of vascular smooth muscle cells to internalize extracellular MMP9. CONCLUSIONS: These data suggest that aortic but not circulating LRP1 is downregulated in patients with AAA and indicates a possible role for this protein in clearing an aneurysm-relevant ligand.

Acute generalized exanthematous pustulosis: atypical presentations and outcomes.

Acute generalized exanthematous pustulosis (AGEP) is an acute drug eruption characterized by erythematous plaques and papules studded with numerous, pinpoint pustules. Several atypical clinical presentations and triggers of AGEP have been described in the literature. These include systemic presentations similar to toxic epidermal necrolysis (TEN) and drug-induced hypersensitivity syndrome (DIHS) and localized presentations mimicking other medication reactions. We herein aim to review atypical presentations and medication triggers of AGEP to assist clinicians in recognizing this condition and making appropriate therapeutic interventions.

A novel agent with histone deacetylase inhibitory activity attenuates neointimal hyperplasia.

PURPOSE: Neointimal hyperplasia (NIH), a pathophysiological event identified in bypass graft and stent re-stenosis, is characterised by aberrant vascular smooth muscle cell (VSMC) migration and proliferation. Recent evidence identifies histone deacetylase modulation as a regulator of VSMC proliferation and migration and a potential therapeutic target in the treatment of NIH. The purpose of our study was to determine the in vitro and in vivo potential of a novel agent, MCT-3, to modulate VSMC migration, proliferation and NIH. METHODS: In vitro VSMC studies utilized reverse transcriptase and real time Q-PCR gene expression analysis, western blot, elisa assay and cellular proliferation and migration scratch assay's. In vivo studies utilized the partial carotid artery ligation model of NIH together with immunohistochemistry in FVB/N mice. RESULTS: MCT-3 treatment induced histone H3 and H4 acetylation and inhibited VSMC migration and proliferation in vitro and significantly attenuated NIH in vivo. MCT-3-mediated regulation of orphan nuclear receptor NUR77, Plasminogen Activator Inhibitor Type-1 (PAI-1) and cyclin dependent kinase inhibitors (CDKI) p21(CIP1/WAF1) and p27(KIP1) expression was also identified. CONCLUSIONS: Together these observations identify a novel agent, MCT-3, with histone deacetylase inhibitory activity, able to inhibit NIH and identify a potential molecular mechanism responsible for these effects. Additional pre-clinical studies may be warranted to determine the potential clinical utility of this compound.

Adult postoperative intussusception: a rare cause of small bowel obstruction.

A case is reported of postoperative jejunojejunal intussusception in a 45-year-old Afro-Caribbean male following an emergency truncal vagotomy and pyloroplasty. This is a rare cause of postoperative small bowel obstruction, and the pathogenesis and diagnosis of postoperative intussusception in the adult is discussed. Differences between conventional childhood, postoperative childhood, adult, and postoperative adult intussusception are outlined.