Femoral Occlusion Research Articles

ASIC3 in dorsal root ganglion neurons contributes to femoral occlusion enhanced sympathetic responsiveness

Acid sensing ion channel subtype 3 (ASIC3) is responsive to acid in the extracellular medium. Prior studies suggest that muscle metabolite lactic acid and ASIC play a role in muscle afferent mediated reflex sympathetic response. Also, femoral occlusion increases the reflex sympathetic nerve response. Thus, we tested the hypothesis that enhanced ASIC3 expression and its responsiveness in primary afferent neurons innervating muscles contribute to the exaggerated reflex sympathetic responses after femoral occlusion. The femoral occlusion was induced by the femoral artery ligation in rats. First, we employed Western blot to examine expression of ASIC3 in dorsal root ganglion (DRG). The data showed that 24 hrs of femoral occlusion led to upregulation of ASIC3 expression in DRG (optical density: 0.93 ± 0.08 in control vs. 1.47 ± 0.04 after occlusion, P<0.05), e.g. 1.58‐fold increase. Second, experiments using whole cell patch‐clamp demonstrated that current amplitude of DRG neurons innervating muscle was larger in response to a lower pH in femoral occlusion. Third, responses of renal sympathetic nerve activity and blood pressure to acid injected into the arterial blood supply of hindlimb muscles were also enhanced after the ligation. This study suggests that ASIC3 has an important contribution to augmented sympathetic responsiveness after femoral occlusion. (Supported by R01 HL078866 and R01 HL090720).

Interstitial nitric oxide concentrations are elevated in rat gastrocnemius muscle following recovery from femoral occlusion

The present study examined the effects of ischemia‐reperfusion on the interstitial levels of nitric oxide (NO) and adenosine (Ado). Eight anesthetized rats had two microdialysis fibers inserted into the gastrocnemius muscle of each leg and perfused with Ringers (control) or 500 μM AOPCP (5'ectonucleotidase inhibitor). Following baseline collections both femoral arteries were clamped for 60 min (samples at 20, 40 and 60 min) and then released (samples at 20 min). With Ringers perfusion there were no increases in interstitial NO (baseline = 4.2±0.4 μM) during ischemia but NO was elevated (P<0.05) following reperfusion (5.4±0.5 μM). Prior to occlusion AOPCP treatment resulted in an increase (P<0.05) in NO from 4.3±0.6 to 5.5±0.5 μM as compared to Ringers. No further increases in NO were observed with AOPCP during ischemia, but NO was further elevated (P<0.05) following reperfusion (6.5±0.6 μM). Interstitial NO concentrations were higher (P<0.05) during AOPCP treatment compared to Ringers at all time points. There were no changes in interstitial Ado during the study. These data show that NO and Ado are not altered during femoral occlusion, but NO is elevated during reperfusion and that NO is even higher during ischemia‐reperfusion when Ado production is inhibited. These findings suggest that NO plays an important role in interstitially mediating vasodialtion during skeletal muscle reperfusion.Supported by NSERC

Femoral occlusion increases hypoxia‐inducible factor‐1α in dorsal root ganglion and hindlimb muscle

Hypoxia inducible factor‐1 (HIF‐1) has an important contribution to pathophysiological changes of homeostasis under conditions of oxygen deprivation as well as ischemia. We employed western blotting methods to examine effects of femoral occlusion on protein expression of HIF‐1α in dorsal root ganglion (DRG), different fiber types of muscle i.e. oxidative and glycolytic muscle. DMOG was used to enhance HIF‐1α activity following local intramuscular injection (IM). Our data show that HIF‐1α was increased in lumbar DRG after formal artery ligation by using a rat model in different time courses as compared with sham control (3.4±0.5 vs 1.1±0.1 fold at 6 hrs; 3.1±0.4 vs 1.2±0.2 fold at 24 hrs; 2.3±0.4 vs 1.1±0.2 fold at 72 hrs; p<0.05). This effect was mimicked by IM of DMOG (5.0±0.3 vs 1.3±0.2 fold at 24 hrs, p<0.05) in lumbar DRG. In contrast, HIF‐1α outside lumbar DRG was not altered, which suggests HIF‐1α was increased due to specifically localized hindlimb. In addition, HIF‐1α was increased in both red and white muscle after femoral occlusion compared with non‐occlusion control; however, the level of HIF‐1α was greater in white muscle as compared with red muscle. In conclusion, femoral occlusion increases HIF‐1α expression in DRG, and differentially increases HIF‐1α expression in different fiber types of muscle. We anticipate that HIF‐1α is likely to contribute to autonomic responses to activation of muscle afferents.

Pyruvate-Fortified Fluid Resuscitation Improves Hemodynamic Stability While Suppressing Systemic Inflammation and Myocardial Oxidative Stress After Hemorrhagic Shock

To determine whether controlled resuscitation with pyruvate-fortified Ringer's (PR) solution vs. conventional lactate Ringer's (LR) more effectively stabilizes mean arterial pressure (MAP) and suppresses myocardial inflammation postresuscitation. Goats were hemorrhaged (255 +/- 22 ml) to lower MAP to 48 +/- 1 mmHg. Next, the right femoral vessels were occluded for 90 min to model tourniquet application. Beginning at 30 min occlusion, LR or PR was infused i.v. at 10 ml/min for 90 min. The femoral occlusions were released at 60 min infusion. At 4 h postocclusion, MAP (mmHg) was increased in PR (59 +/- 4) vs. LR (47 +/- 3) resuscitated goats (p < 0.05). PR also more effectively augmented circulating HCO3 and total base excess. Nitrosative stress, detected in myocardium 4 h after LR resuscitation, was suppressed by PR. Finally, PR prevented the increase in circulating neutrophils that accompanied LR resuscitation. Relative to LR, resuscitation with PR more effectively stabilized MAP, suppressed myocardial nitrosative stress and minimized systemic inflammation after hemorrhagic shock with hindlimb ischemia-reperfusion.

Internal Carotid Artery Stenting in Patients over 80 Years of Age: Single‐Center Experience and Review of the Literature

Thirty percent to 40% of strokes in the elderly are secondary to carotid bifurcation disease. The treatment of internal carotid artery (ICA) stenosis in this patient population is a clinical dilemma. Age more than 80 years is a risk factor for carotid endarterectomy (CEA). Carotid artery stenting (CAS) may be also associated with increased peri-procedural complications in this age group. This study was a single-center, retrospective database analysis evaluating CAS in patients more than 80 years old. Primary outcome included death, myocardial infarction (MI), or ipsilateral stroke. Secondary outcome included re-stenosis at 30 days, 6 months, and 1-year post-procedure. Between March 2001 and March 2004, CAS was performed in 178 patients. Twenty-four patients were more than 80 years old (range 80-91), and 16 men, 70.8%, were symptomatic. Success rate was 100% with residual stenosis of <20%. At the 30 days follow-up there was 1 non-Q wave MI (4.2%), 1 transitory ischemic attack (TIA), and 1 femoral occlusion in the symptomatic group. There were no deaths at 1-year follow-up evaluation as well as no ICA re-stenosis. CAS can be performed in patients more than 80 years old. Complications may be higher than in younger patients. However, because of the high prevalence of stroke in octogenarians, randomized trials should include this patient population.

α‐Adrenergic and neuropeptide Y Y1 receptor control of collateral circuit conductance: influence of exercise training

This study evaluated the role of alpha-adrenergic receptor- and neuropeptide Y (NPY) Y1 receptor-mediated vasoconstriction in the collateral circuit of the hind limb. Animals were evaluated either the same day (Acute) or 3 weeks following occlusion of the femoral artery; the 3-week animals were in turn limited to cage activity (Sed) or given daily exercise (Trained). Collateral-dependent blood flows (BFs) were measured during exercise with microspheres before and after alpha-receptor inhibition (phentolamine) and then NPY Y1 receptor inhibition (BIBP 3226) at the same running speed. Blood pressures (BPs) were measured above (caudal artery) and below (distal femoral artery) the collateral circuit. Arterial BPs were reduced by alpha-inhibition (50-60 mmHg) to approximately 75 mmHg, but not further by NPY Y1 receptor inhibition. Effective experimental sympatholysis was verified by 50-100% increases (P < 0.001) in conductance of active muscles not affected by femoral occlusion with receptor inhibition. In the absence of receptor inhibition, vascular conductance of the collateral circuit was minimal in the Acute group (0.13 +/- 0.02), increased over time in the Sed group (0.41 +/- 0.03; P < 0.001), and increased further in the Trained group (0.53 +/- 0.03; P < 0.02). Combined receptor inhibition increased collateral circuit conductances (P < 0.005), most in the Acute group (116 +/- 37%; P < 0.02), as compared to the Sed (41 +/- 6.6%; P < 0.001) and Trained (31 +/- 5.6%; P < 0.001) groups. Thus, while the sympathetic influence of the collateral circuit remained in the Sed and Trained animals, it became less influential with time post-occlusion. Collateral conductances were collectively greater (P < 0.01) in the Trained as compared to Sed group, irrespective of the presence or absence of receptor inhibition. Conductances of the active ischaemic calf muscle, with combined receptor inhibition, were suboptimal in the Acute group, but increased in Sed and Trained animals to exceptionally high values (e.g. red fibre section of the gastrocnemius: approximately 7 ml min(-1) (100 g)(-1) mmHg(-1)). Thus, occlusion of the femoral artery promulgated vascular adaptations, even in vessels that are not part of the collateral circuit. The presence of active sympathetic control of the collateral circuit, even with exercise training, raises the potential for reductions in collateral BF below that possible by the structure of the collateral circuit. However, even with release of this sympathetic vasoconstriction, conductance of the collateral circuit was significantly greater with exercise training, probably due to the network of structurally larger collateral vessels.

Posterior wall capture and resultant common femoral occlusion complicating StarClose access closure

Vascular closure devices have been shown to decrease hemostasis and ambulation time after percutaneous transcatheter procedures. The StarClose Vascular Closure System (Abbott Vascular, Redwood City, Calif) is a shape memory clip-mediated device that is designed to provide extraluminal mechanical closure without compromising the arterial lumen. We report a case of iatrogenic arterial occlusion secondary to mechanical closure of the anterior and posterior walls of the common femoral artery with a StarClose device. We provide objective observations from the rescue surgical intervention and discuss potential mechanisms of device failure.

Stenting for superficial femoral artery atherosclerotic occlusion: long-term follow-up results

Recent advances in interventional devices and technology have greatly improved the results of percutaneous transluminal angioplasty (PTA), and it is now being widely used. However, it is important to obtain information regarding its results and its long-term patency. We examined the primary success rates and long-term patency in 29 limbs out of 27 patients with superficial femoral artery (SFA) occlusion who underwent PTA with self-expandable stents. Among the 29 lesions, 19 were long occlusions (>10 cm) and 10 were short (<10 cm). Overall primary success was achieved in 26 of the 29 limbs (90%). There were three unsuccessful cases in which the patients were on dialysis and had hard calcification in the arterial walls. After 3 years, primary patency, primary-assisted patency, and secondary-assisted patency were 81%, 86%, and 96%, respectively. In the case of short occlusions (<10 cm), the 3-year patency was 100%. Both the primary success rate and the long-term patency were considerably better than expected. Our results with self-expanding stents were superior to previously reported results and were not inferior to those of surgical bypass. Therefore, PTA may be considered as a good first option for the treatment of SFA occlusions.

Utilização da veia ilíaca externa recanalizada para implante de cateter de longa permanência para hemodiálise

O uso de cateteres venosos cervicais para hemodiálise leva freqüentemente à oclusão dessas veias. Como alternativa, os acessos venosos femorais são válidos, porém o seu uso também está associado à oclusão dessas veias e a um maior índice de infecção. Vias alternativas são cada vez mais utilizadas na impossibilidade dos acessos previamente mencionados. Descrevemos neste relato de caso uma alternativa para o implante de cateter de longa permanência para hemodiálise usando a veia ilíaca externa recanalizada. Comentamos os detalhes da técnica utilizada, suas vantagens e desvantagens.

α‐Adrenergic inhibition increases collateral circuit conductance in rats following acute occlusion of the femoral artery

This study evaluated whether alpha-adrenergic activation contributes to collateral circuit vascular resistance in the hindlimb following acute unilateral occlusion of the femoral artery in rats. Blood pressures (BPs) were measured above (caudal artery) and below (distal femoral artery) the collateral circuit. Arterial BPs were reduced (15-35 mmHg) with individual (prazosin, rauwolscine) or combined (phentolamine) alpha-receptor inhibition. Blood flows (BFs) were measured using microspheres before and after alpha inhibition during the same treadmill speed. alpha(1) inhibition increased blood flow by approximately 40% to active muscles that were not affected by femoral occlusion, whereas collateral-dependent BFs to the calf muscles were reduced by 29 +/- 8.4% (P < 0.05), due to a decrease in muscle conductance with no change in collateral circuit conductance. alpha(2) inhibition decreased both collateral circuit (39 +/- 6.0%; P < 0.05) and calf muscle conductance (36 +/- 7.3%; P < 0.05), probably due to residual alpha(1) activation, since renal BF was markedly reduced with rauwolscine. Most importantly, inhibiting alpha(2) receptors in the presence of alpha(1) inhibition increased (43 +/- 12%; P < 0.05) collateral circuit conductance. Similarly, non-selective alpha inhibition with phentolamine increased collateral conductance (242 +/- 59%; P < 0.05). We interpret these findings to indicate that both alpha(1)- and alpha(2)-receptor activation can influence collateral circuit resistance in vivo during the high flow demands caused by exercise. Furthermore, we observed a reduced maximal conductances of active muscles that were ischaemic. Our findings imply that in the presence of excessive sympathetic activation, which can occur in the condition of intermittent claudication during exertion, an exaggerated vasoconstriction of the existing collateral circuit and active muscle will occur.

Transhepatic, Transseptal, Anterograde Balloon Angioplasty for Recurrent Neonatal Coarctation

Transhepatic cardiac catheterization is useful in patients in whom more conventional routes of access are no longer patent or associated with undesirable risks. We describe our success in performing transhepatic, transeptal, anterograde balloon angioplasty without complication in a 1.6 kg neonate with recurrent aortic coarctation and femoral venous occlusion. This report illustrates the utility of a transhepatic approach, even in very small patients.

Prevention of Tissue Death by Killer Cells?

Based on the observation that mouse strains differing in lymphocyte-mediated immune responses differed also markedly in collateral density, in their ability to develop a collateral circulation, in remodeling and the expression of VEGF-A after femoral artery occlusion, previously reported by Scholz et al,1 Chalothorn,2 and Helisch et al,3 van Weel et al had set out to test the role of lymphocytes in arteriogenesis.4 They found that NK-cells and CD4 cells are important for collateral vessel growth and that substitution in animals deficient for these cells accelerated collateral development. These elegant studies, using mouse genetics as well as antibody-based deletion experiments, provide a solution to a long smoldering discussion about the role of lymphocytes in arteriogenesis as well as in angiogenesis. As early as 1976 Klintworth and collaborators5 showed that angiogenesis in response to corneal injury was associated with an influx of leukocytes. The causal relationship was proven by irradiation to depress the bone marrow leading to impaired angiogenesis. The contribution of subsets of leukocytes was difficult to discern at the time because …

Exercise Training Improves Peripheral Vascular Function Following Chronic Femoral Artery Occlusion in the Ossabaw Swine Model of Cardiometabolic Risk

PURPOSE: Peripheral arterial disease (PAD) is a major cause of morbidity and mortality in the developed world. Diabetes is a strong risk factor for PAD; thus, incidence of PAD can only be expected to rise as the prevalence of diabetes increases. The treatment of choice for PAD is exercise training. Training is well-known to increase collateral-dependent peripheral blood flow in healthy animals, mainly rodents. However, it is unclear whether training induces the same changes in collateral structure and/or function in the setting of the metabolic syndrome. Thus, we investigated peripheral vascular function in Ossabaw swine. Results from this unique large animal model of cardiometabolic risk may be closely relevant to human disease. METHODS: Swine were divided into 3 groups: sedentary control (C, N=6), sedentary high fat/cholesterol fed (H, N=4), and exercise trained H (HX, N=6). H and HX pigs were fed a high fat/cholesterol diet (46% kcal from fat; 2% cholesterol w:w) for 50 wk. Hydrogenated soybean oil (containing 56% trans fatty acids) served as the fat source. H and HX pigs were obese, hyperlipidemic, hypertensive, and insulin resistant, all characteristics of the metabolic syndrome. HX pigs trained on a motorized treadmill 4 d/wk for 7 wk. Pigs wore a wireless heart rate monitor for continuous assessment of exercise intensity. After a 10-min warmup, treadmill speed was increased until heart rate reached ∼65-75% of max. Pigs then exercised for 30 min, followed by a 5-min cool down. After 4 wk of training, the right femoral artery was occluded under general anesthesia using surgical suture. After recovery, pigs continued training for a further 3 wk. Pigs were then anesthetized for measurement of mean saphenous artery pressure (SAP). RESULTS: SAP did not differ between groups in the left (non-occluded) limb. Left SAP fell ∼50% in all groups in response to acute occlusion of the left femoral artery and did not significantly recover by 10 min post-occlusion. In the right (chronically occluded) limb, SAP was significantly higher in HX than in C pigs (71 ± 5 vs 49 ± 5 mm Hg; p=0.013). Recovery of SAP after 4 wk of femoral occlusion was complete in the HX group (113 ± 14% of pre-occlusion left SAP), and was greater than that in the H group (48 ± 23%; p=0.017 vs HX) or the C group (75 ± 8%, p=NS vs HX). Typical "corkscrew" collaterals were angiographically visible in the right thigh, suggesting that structural remodeling occurred in response to the chronic femoral occlusion. CONCLUSIONS: Exercise training significantly improves peripheral vascular function in obese Ossabaw swine, a novel and useful large animal model for the study of the effects of exercise on PAD. Support: HL062552, RR013223 (MS).

Influence of α 2 ‐adrenergic Inhibition on Collateral Blood Flow to the Calf Muscle Following Acute Femoral Occlusion

Immediately following arterial occlusion collateral vessels are not fully patent. This exacerbates limb ischemia during exercise compared to later when better patency has occurred. The objective of this study was to determine if α2 receptors contribute to this exaggerated resistance of the collateral circuit following acute occlusion of the femoral artery (FA). Male SD rats (~350g) (n=14) received unilateral femoral ligation and recovered for 4 hours, following which exercise (20m/min) blood flow (BF) was measured using μspheres (85Sr); caudal and distal FA pressures were also obtained during exercise. Rats were then given rauwolscine (RAU), an α2 antagonist, sufficient (150 μg) to decrease systemic pressure during exercise 15±4.8 mmHg (p<0.01) indicating release of tonic constriction in the vasculature. Arterial pressure in the distal femoral artery decreased 24% (p<0.05) with RAU. Blood flow was again obtained with μspheres (141Ce) during the same exercise intensity. RAU decreased renal conductance (ml/min/100g/mmHg) 39% (p<0.05). Calf muscle BF (ml/min/100g) was reduced by 42% (p<0.001), with specific decreases in both red and white muscle portions (p< 0.0001), with α2 inhibition; this was due to a decrease (p<0.05) in collateral circuit (38%) and calf muscle (22%) conductances. The surprising loss of collateral circuit conductance with α2 inhibition implies confounding counteractive responses occurred. This could be due to an exaggerated α1 mediated constriction, as possibly characterized by the reduction in renal conductance. Support: HL 37387-17

Is Magnetic Resonance Image Guidance the Key to Opening Chronic Total Occlusions?

Through progressive plaque growth or fibrotic organization of occlusive thrombus, atherosclerosis may result in chronic total occlusion (CTO) of a major arterial conduit. If CTO develops slowly, collateral pathways may supply sufficient perfusion to retain tissue viability despite occlusion of the major inflow conduit. However, such collateral-mediated perfusion rarely matches that provided by an open main conduit, particularly during the peak demand of regional muscular activity. Although strategies to limit regional oxygen demand (eg, β-blockers for the treatment of angina pectoris) or to enhance collateral function (eg, a walking program for superficial femoral occlusion, experimental angiogenesis) may be of some benefit, these approaches generally offer less complete return of normal physiology and relief of ischemic symptoms than does direct revascularization of the occluded vessel. With surgical bypass, the nature of the occlusion (its length, duration, tortuosity, calcification) is less important than the presence of a suitable distal anastomotic target. On the other hand, with catheter-based techniques, success depends heavily on these lesion characteristics. In fact, crossing such occluded segments with a guidewire remains the dominant barrier to catheter-based treatments of occluded arterial segments. Once the guidewire has been passed successfully into the distal true lumen, the process of dilating and stenting the segment is usually straightforward and durable, at least with the use of drug-eluting stents in coronary CTOs.1,2 Article p 1101 Devices designed to cross CTOs should have 3 key features: an ability to distinguish a true luminal path from one created within (dissection) or through (perforation) the vessel wall of the occluded segment, an ability to change direction (steer) to correct deviations from the desired path through the occlusion, and an ability to penetrate the frequently fibrotic and focally calcific substance of the occlusion through the use of either mechanical stiffness or an alternative energy modality (laser, …

Differences in Risk Factors for Lower Extremity Arterial Occlusive Disease

Patients undergoing lower extremity revascularization have associated cardiovascular risks: smoking, hypertension, dyslipidemia, and diabetes. This study evaluated the impact of cardiovascular risk factors on proximal versus distal arterial occlusive disease in patients undergoing lower extremity revascularization as adjusted to a control group without vascular disease. We performed a retrospective, case-control study that included 151 patients undergoing lower extremity revascularization and 229 patients undergoing knee and hip replacement (controls). Risk factors were determined for each of three separate groups undergoing revascularization for different levels of occlusive disease: aortoiliac, superficial femoral, and popliteal-tibial. Comparisons to controls were tested using t-tests or chi-square tests and multiple logistic regression. Dyslipidemia was associated with a significant risk of aortoiliac (odds ratio [OR]=3.4; p=0.0006) and superficial femoral occlusion (OR=2.8; p=0.01) but was less strongly associated with popliteal-tibial occlusion (OR=2.1; p=0.09). Smoking was strongly associated with aortoiliac (OR=4.5; p=0.004) and superficial femoral disease (OR=4.6; p=0.0007) but not popliteal-tibial disease (OR=1.3; p=0.53). In contrast, diabetes mellitus and chronic renal insufficiency were strong risk factors for popliteal-tibial occlusion (OR=5.4, p=0.0002; OR=3.9, p=0.01, respectively), but were not significant risk factors for aortoiliac or superficial femoral occlusion. These data, which use revascularization level as a surrogate marker for lower extremity arterial disease, suggest that the risk factor profile for proximal disease differs from that of distal disease. These findings may reflect differences in the biology of disease and indicate that different risk factors have various anatomic influences on arterial disease formation.

Femoral vein occlusion and spontaneous collateral ectasia presenting as recurrent hernia of the groin: a case report

Femoral vein occlusion is not a common complication even after repeated hernia repair. We describe a case of a 14-year-old boy with a visible and soft, yet irreducible, mass below the inguinal ligament after 3 previous inguinal hernia repairs and heart catheterization in infancy. Further examination showed dilated venous collaterals, bypassing an occluded common femoral vein via the testicular sheaths and across the pelvic floor. We discuss etiology, diagnostic pitfalls, therapeutic options, and possible future complications, with a literature review.

Noninvasive Imaging of Angiogenesis With a 99m Tc-Labeled Peptide Targeted at α v β 3 Integrin After Murine Hindlimb Ischemia

Noninvasive imaging strategies play a critical role in assessment of the efficacy of angiogenesis therapies. The alpha(v)beta3 integrin is activated in angiogenic vessels and represents a potential target for noninvasive imaging of angiogenesis. We evaluated a 99mTc-labeled peptide (NC100692) targeted at alpha(v)beta3 integrin for imaging in an established murine model of angiogenesis induced by hindlimb ischemia. Control mice (n=9) or mice with surgical right femoral artery occlusion (n=29) were injected with NC100692 (1.5+/-0.2 mCi IV) at different times after femoral occlusion (1, 3, 7, and 14 days) for in vivo pinhole planar gamma camera imaging. Tissue from hindlimb proximal and distal to occlusion was excised for gamma well counting and for immunostaining. On in vivo pinhole images, increased focal NC100692 activity was seen distal to the occlusion at days 3 and 7. This increase in relative NC100692 activity was confirmed by gamma well counting. Lectin staining confirmed increased angiogenesis in the ischemic hindlimb at these time points. A fluorescent analogue of NC100692 was used to confirm specificity and localization of the targeted tracer in cultured endothelial cells. In addition, endothelial cell specificity was confirmed on tissue sections with the use of dual immunofluorescent staining of endothelium and the fluorescent analogue targeted at the alpha(v)beta3 integrin. A 99mTc-labeled peptide (NC100692) targeted at alpha(v)beta3 integrin selectively localized to endothelial cells in regions of increased angiogenesis and could be used for noninvasive serial "hot spot" imaging of angiogenesis. This targeted radiotracer imaging approach is a major advance in tracking therapeutic myocardial angiogenesis and has an important clinical potential.

Three arm randomised trial of femoral vascular occlusion devices

Three arm randomised trial of femoral vascular occlusion devices

Identification of differentially expressed genes like cofilin2 in growing collateral arteries

Arteriogenesis, the growth of pre-existing collateral arteries, can be induced in rabbits by occlusion of the femoral artery. In order to analyze the differential gene expression in arteriogenesis, cDNA of collateral arteries 24 h after femoral occlusion or sham operation was subjected to suppression subtractive hybridization (SSH). We demonstrated an upregulation of the U6 snRNA binding protein Lsm5, cytochrome b, an expressed sequence tag, and the actin-depolymerizing factor cofilin2 mRNA in collateral arteries 24 h after femoral ligation. For cofilin2, we also detected an increase in the protein level and a localization predominantly in smooth muscle cells of collaterals. Simultaneously with the upregulation of cofilin2 we found a downregulation of the α-smooth muscle actin mRNA in growing collateral arteries. In summary, our data showed an augmented expression level of genes contributing to different fundamental processes of arteriogenesis.