Feasibility of virtual reality-delivered pain psychology therapy for cancer-related neuropathic pain: a pilot randomised controlled trial

Virtual reality-delivered psychological therapies have recently been investigated as non-pharmacological management for acute and chronic pain. However, no virtual reality pain therapy software existed that met the needs of cancer patients with neuropathic pain. We created a bespoke virtual reality-delivered pain therapy software programme to help cancer patients manage neuropathic pain incorporating guided visualisation and progressive muscle relaxation techniques, whilst minimising the risk of cybersickness in this vulnerable patient population. This randomised controlled pilot study evaluated the feasibility, acceptability, recruitment rates and risk of cybersickness of this pain therapy software programme. Clinical outcomes including opioid consumption, pain severity, pain interference and global quality of life scores were secondary aims. Of 87 eligible cancer patients with neuropathic pain, 39 were recruited (47%), allocated to either the intervention (20 patients, virtual reality pain therapy software programme) or control (19 patients, viewing virtual reality videos). Four patients withdrew before the 3-month follow-up (all in the control group). Pre-existing dizziness (Spearman ρ 0.37, p = 0.02) and pre-existing nausea (Spearman ρ 0.81, p < 0.001) were significantly associated with risk of cybersickness in both groups. Patients in the intervention group reported less cybersickness, as well as tolerated and completed all therapy sessions. At 1- and 3-month follow-up, there were trends in the intervention group towards reductions in: oral morphine equivalent daily dose opioid consumption (-8 mg and -4 mg; vs. control: 0 mg and +15 mg respectively); modified Brief Pain Inventory pain severity (-0.4, -0.8; vs. control +0.4, -0.3); and pain interference (-0.9, -1.8; vs. control -0.2, -0.3) scores. The global quality of life subscale from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30 was not significantly changed between groups at 1 and 3 months (intervention: -5, -8; vs. control: +3, +4). This newly created virtual reality-delivered pain therapy software programme was shown to be feasible and acceptable to cancer patients with neuropathic pain. These results will aid the design of a definitive multicentre randomised controlled trial.

Fast nastic motion of plants and bioinspired structures

The capability to sense and respond to external mechanical stimuli at various timescales is essential to many physiological aspects in plants, including self-protection, intake of nutrients and reproduction. Remarkably, some plants have evolved the ability to react to mechanical stimuli within a few seconds despite a lack of muscles and nerves. The fast movements of plants in response to mechanical stimuli have long captured the curiosity of scientists and engineers, but the mechanisms behind these rapid thigmonastic movements are still not understood completely. In this article, we provide an overview of such thigmonastic movements in several representative plants, including Dionaea, Utricularia, Aldrovanda, Drosera and Mimosa. In addition, we review a series of studies that present biomimetic structures inspired by fast-moving plants. We hope that this article will shed light on the current status of research on the fast movements of plants and bioinspired structures and also promote interdisciplinary studies on both the fundamental mechanisms of plants' fast movements and biomimetic structures for engineering applications, such as artificial muscles, multi-stable structures and bioinspired robots.

Viral Anti-Inflammatory Proteins Target Diverging Immune Pathways with Converging Effects on Arterial Dilatation, Plaque and Apoptosis

Abdominal aortic aneurysms are often fatal due to atherosclerosis, thromboembolism, rupture, and hemorrhage, however, treatment is limited to expectant monitoring and surgical intervention. Inflammation is detected in aneurysms and in plaque with associated increased apoptosis, chemokines, cytokines, hemorrhage, and thrombosis. We compared treatment with three different myxomavirus-derived anti-inflammatory proteins targeting apoptosis, thrombosis, and chemokine pathways. The effect of each protein on aortic dilatation and plaque growth was assessed after angioplasty in Apolipoprotein Enull mice. Four myxomavirus-derived proteins were studied; Serp-1 a serine protease inhibitor (serpin) targeting thrombotic and thrombolytic proteases, Serp-2 a cross-class serpin inhibiting granzyme B and caspases 1 and 8, M-T7 a broad spectrum C, CC, and CXC chemokine inhibitor, and R171E, an inactive M-T7 mutant. Cell invasion, elastin breaks, plaque progression, and aortic dilatation were significantly reduced by Serp-1, Serp-2, or M-T7 protein treatment, but not by R171E. PCR array analysis detected altered expression of a group of shared 40 apoptotic genes in monocytes after treatment with each active protein, but not R171E. Interference with inflammatory cell responses, through highly divergent inflammatory response pathways, produces similar reductions in monocyte invasion, arterial dilatation, and plaque growth potentially through modified expression of apoptotic genes.

Defining the anti-inflammatory activity of a potent myxomaviral chemokine modulating protein, M-T7, through site directed mutagenesis

Viral chemokine modulating proteins provide new and extensive sources for therapeutics. Purified M-T7, a poxvirus-derived secreted immunomodulatory protein, reduces mononuclear cell invasion and atheroma in rodent models of angioplasty injury as well as aortic and renal transplant, improving renal allograft survival. M-T7 is a rabbit species-specific interferon gamma receptor (IFNγR) homolog, but also inhibits chemokine/glycosaminoglycan (GAG) interactions for C, CC and CXC chemokines, with cross-species specific inhibitory activity. M-T7 anti-atheroma activity is blunted in GAG deficient mouse aortic transplants, but not in CC chemokine receptor deficient transplants, supporting M-T7 interference in chemokine/GAG interactions as the basis of the atheroma-inhibitory activity. We have assessed point mutants of M-T7 both in vivo in a mouse angioplasty model and in vitro in tissue culture and binding assays, in order to better define the primary mechanism of anti-atheroma activity. Of these M-T7 mutants, the R(171)E and E(209)I M-T7 mutants lost inhibitory activity for plaque growth in hyperlipidemic ApoE(-/-) mice after angioplasty injury and R(171)E, moreover, greatly exacerbated plaque growth and inflammation. F(137)D retained some inhibitory activity for plaque growth. In contrast, for cell migration assays, M-T7-His6X, F(137)D, R(171)E, and E(209)I all inhibited CC chemokine (RANTES) mediated cell migration. For the ligand binding assays, R(171)E and E(209)I had significantly reduced binding to RANTES and IFNγ, whereas F(137)D retained wild-type binding activity. Heparin treatment further reduced RANTES binding of all three M-T7 mutants. In summary, point mutations of M-T7, R(171)E and E(209)I, exhibited reduced anti-inflammatory properties in vivo after mouse angioplasty with a loss of in vitro binding to RANTES and IFNγ, indicating these point mutations partially disrupt M-T7 ligand-binding activities. Unexpectedly, the M-T7 mutants all retained inhibitory activity for human monocyte THP-1 cell migration ex vivo, suggesting additional inhibitory properties against human monocyte THP-1 cells that are independent of chemokine inhibition.

Increased atherogenesis during Streptococcus mutans infection in ApoE-null mice

Streptococcus mutans, a dental caries pathogen, also causes endocarditis and is detected in atheroscelerotic plaque. We investigated the potential for an invasive strain of S. mutans, OMZ175, to accelerate plaque growth in apolipoprotein E deficient (ApoE(null)) mice without and with balloon angioplasty (BA) injury, a model of restenosis. ApoE(null) mice were divided into 4 groups (N = 10), 2 with and 2 without BA. One each of the BA and non-BA groups was infected with S. mutans (Sm). S. mutans DNA, plaque area, inflammatory cell invasion, and Toll-like receptor (TLR) expression were measured at 6-20 weeks post-infection. S. mutans genomic DNA was detected in the aorta, liver, spleen, and heart. Plaque growth was significantly increased in infected mice with BA (Sm+BA) vs. those in the non-infected groups (p < 0.03). Plaque size was increased after infection without BA (Sm), but did not reach significance. Aortic specimens from both S. mutans and Sm+BA groups displayed increased numbers of macrophages, and TLR4 expression was increased in BA mice. In conclusion, S. mutans infection accelerated plaque growth, macrophage invasion, and TLR4 expression after angioplasty. S. mutans may also be associated with atherosclerotic plaque growth in non-injured arteries.

Transplant vasculopathy: viral anti-inflammatory serpin regulation of atherogenesis

BACKGROUND

Surgical and ischemic injury to the artery wall initiates vascular wound-healing responses that stimulate atherosclerotic plaque growth. The plasminogen activators have cellular chemotactic, adhesion, and proteolytic activity. Serp-1 is a secreted myxoma virus glycoprotein serpin that binds and inhibits plasminogen activators. We have examined the effects of Serp-1 on plaque growth and inflammatory cell invasion in animal models after balloon injury and after aortic allograft transplant.

METHODS

We used histologic analysis to assess 4 animal models of angioplasty-mediated injury and 2 models of aortic allograft transplant for intimal hyperplasia and cellular invasion. We assessed plasminogen activator (uPA and tPA) and inhibitor (PAI-1) expression in rat iliofemoral arteries after balloon injury using Western blot, enzyme activity, and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Plaque growth after balloon injury decreased after Serp-1 treatment in all balloon-injury models tested. Transplant vasculopathy also significantly decreased in 2 rat models of aortic allograft transplant. Infusion of a Serp-1 active site mutant, that lacked plasminogen activator inhibiting activity, did not inhibit plaque growth. Quantitative RT-PCR detected increased transcription of PAI-1 mRNA. Increased PAI-1 protein and enzyme-inhibitory activity was also detected in Serp-1-treated arteries by activity assay and Western blot.

CONCLUSIONS

Thrombolytic serpins are central regulatory agents in vascular wound-healing responses. Investigation of the inhibitory mechanisms of viral serpins may provide new insights into atherogenesis.

Optical detection of triggered atherosclerotic plaque disruption by fluorescence emission analysis

Fluorescence emission analysis (FEA) has proven to be very sensitive for the detection of elastin, collagen and lipids, which are recognized as the major sources of autofluorescence in vascular tissues. FEA has also been reported to detect venous thromboemboli. In this paper we have tested the hypothesis that FEA can reproducibly detect in vivo and in vitro triggered plaque disruption and thrombosis in a rabbit model. Fluorescence emission (FE) spectra, recorded in vivo, detected Russell's viper venom (RVV)-induced transformation of atherosclerotic plaque. FE intensity at 410-490 nm 4 weeks after angioplasty was significantly lower (P < 0.0033 by analysis of variance) in RVV-treated rabbits when compared to control animals with stable plaque. FE spectral profile analyses also demonstrated a significant change in curve shape as demonstrated by polynomial regression analysis (R2 from 0.980 to 0.997). We have also demonstrated an excellent correlation between changes in FE intensity and the structural characteristics detected at different stages of "unstable atherosclerotic plaque" development using multiple regression analysis (R2 = 0.989). Thus, FEA applied in vivo is a sensitive and highly informative diagnostic technique for detection of triggered atherosclerotic plaque disruption and related structural changes, associated with plaque transformation, in a rabbit model.

Detection of transplant vasculopathy in a rat aortic allograft model by fluorescence spectroscopic optical analysis

BACKGROUND AND OBJECTIVE

Transplant vasculopathy is a leading cause of late cardiac graft loss. We have examined laser-induced fluorescence (LIF) spectroscopy as an optical diagnostic tool for detection of intimal plaque development and inflammatory cellular invasion in a rat model of aortic allograft transplant.

STUDY DESIGN/MATERIALS AND METHODS

Infrarenal aortic segments were transplanted from Lewis to Sprague Dawley rats. A range of vasculopathy development was produced by treatment with a viral anti-inflammatory protein. LIF spectra were recorded from the intima of aortic implants at 28 days. Fluorescence intensity was analyzed for correlation with vasculopathy development.

RESULTS

Significant differences in LIF intensity at 400-450 nm (P < or = 0.05 by ANOVA) were detected. LIF emission was correlated with plaque growth (R2 = 0.980), vessel narrowing (R2 = 0.964), and cellular invasion (R2 = 0.971) by regression analysis.

CONCLUSION

LIF optical analysis provides a nontraumatic diagnostic approach for detection of atherosclerosis prior to cardiac transplant or during development of vasculopathy after transplant.

The viral anti-inflammatory chemokine-binding protein M-T7 reduces intimal hyperplasia after vascular injury

Chemokines and IFN-gamma function as central regulators of inflammatory responses to vascular injury. Both classes of cytokines are upregulated during restenosis, a response to vascular injury that leads to recurrent atherosclerotic plaque growth, but the relative impact of each class of cytokines remains undetermined. M-T7 is a secreted myxoma viral immunomodulatory glycoprotein that functions both as a species-specific inhibitor of rabbit IFN-gamma and as a chemokine-binding protein, interacting with a wide range of C, C-C, and C-X-C chemokines in a species-nonspecific fashion. We wished to (a) assess the efficacy of purified M-T7 protein in inhibiting intimal hyperplasia after angioplasty injury and (b) exploit unique species-specific functions of M-T7 in order to judge the relative importance of each cytokine class on plaque growth. Anesthetized New Zealand white rabbits and Sprague-Dawley rats received either M-T7 or control at the time of arterial angioplasty injury. Histological analysis at 28 days demonstrated significant reductions in intimal hyperplasia with M-T7 treatment in both models, with an associated early inhibition of inflammatory cell invasion. Purified M-T7 protein inhibits intimal hyperplasia after angioplasty injury in a species-nonspecific fashion, thus implicating the chemokine-binding activity as more critical for prevention of plaque growth after vascular injury.

Inhibition of transplant vasculopathy in a rat aortic allograft model after infusion of anti-inflammatory viral serpin

BACKGROUND

Transplant vasculopathy remains a difficult therapeutic problem, resulting in the majority of late cardiac graft losses. This chronic vascular disease is thought to be triggered by alloantigen-dependent and alloantigen-independent inflammatory factors. Despite improved 1-year survival, the incidence of transplant vasculopathy has not improved with current immunosuppressive protocols. Highly effective strategies have evolved in the large DNA viruses that shield infecting viruses from host inflammatory responses. Serp-1 is a secreted myxoma virus anti-inflammatory serine proteinase inhibitor. Serp-1 inhibits plasminogen activators in a manner similar to plasminogen activator inhibitor (PAI-1), a vascular protein that plays a pivotal regulatory role in vascular wound healing. In this study, we tested the ability of purified Serp-1 protein to ameliorate posttransplant vasculopathy after rat aortic allograft surgery.

METHODS AND RESULTS

Serp-1 protein or controls were infused into 98 rats immediately after segmental aortic allograft transplantation. After either late (28 days, 64 rats) or early (12 to 48 hours, 24 rats) follow-up, transplanted aortic segments were harvested for morphological and immunohistochemical analysis. Significant reductions in intimal plaque growth (P<0.002) and mononuclear cell invasion (P<0.033) were detected after Serp-1 infusion at nanogram doses. Serp-1 reduced early macrophage (P<0.0016) and nonspecific lymphocyte (P<0.0179) invasion into medial and adventitial layers and inhibited associated depletion of medial smooth muscle cells (P<0.0006).

CONCLUSIONS

Infusion of a viral anti-inflammatory serpin, Serp-1, significantly reduces early inflammatory responses and later luminal occlusion in a rat aortic allograft model.

Comparison of two blood pool contrast agents for 0.5-T MR angiography: experimental study in rabbits

PURPOSE

To evaluate two experimental blood pool agents for potential use in equilibrium phase abdominal magnetic resonance (MR) angiography.

MATERIALS AND METHODS

MR imaging at 0.5 T was performed in 37 rabbits before and after intravenous injection of a gadolinium-based blood pool contrast agent (SH L 643 A), superparamagnetic iron oxide blood pool agent (SH U 555 C), or gadopentetate dimeglumine. T1-weighted fast spoiled gradient-echo images from the renal arteries to below the iliac bifurcation were obtained. The aorta-to-tissue signal difference-to-noise ratio (SDNR) was measured over time.

RESULTS

Both blood pool agents yielded excellent demonstration of the rabbit abdominal aorta. At a dose of 0.1 mmol/kg, both provided a statistically significant increase in aorta-to-tissue SDNR in comparison with that achieved with gadopentetate dimeglumine (200% increase for SH L 643 A, 95% increase for SH U 555 C; P < .05). A 0.1 mmol/kg dose of SH L 643 A provided a 24% increase in SDNR relative to the increase with a 0.37 mmol/kg dose of gadopentetate dimeglumine. Time-dependent enhancement properties of the blood pool agents differed due to differences in elimination method.

CONCLUSION

Both blood pool agents were found to be promising contrast agents for 0.5-T MR angiography; however, their clinical applicability warrants further investigation. The gadolinium-based agent had several advantages over the iron oxide compound, including less T2* dephasing, lack of susceptibility artifacts, and fast renal elimination.

Laser-induced fluorescence (LIF) recognition of the structural composition of porcine heart valves

Reconstruction and replacement of heart valves with grafts fro pig tissue is a common procedure. However, bioprosthetic valves wear out in a shorter time span than mechanical valves. Bioprosthetic valve structure may contribute to degenerative changes that lead to valve failure. There is, at present, no method to examine the structure of a tissue valve prior to implant. Laser-induced fluorescence (LIF) of natural fluorophores is an elegant method developed for the detection of tumors, dermal lesions and atherosclerosis. We have studied LIF as a potential diagnostic technique for analysis of valvular tissue. Using excimer laser excitation, we examined natural fluorescence recorded from porcine aortic, mitral and pulmonary valves. All three valve outflow surface tissue layers are less fluorescent at 390-450 nm than the inflow layers. Immunohistochemical analysis of collagen I and elastin content in inflow and outflow surface layers of all three valves correlated well with LIF intensities and dI/d lambda values at selected wavelengths. In conclusion, the differences observed in emitted LIF from valve surface layers are found to correlate well with diversity in the structural protein content. The LIF spectroscopic measurements may provide an appropriate tool for examination of tissue valve structure prior to use for implantation.

Atherosclerosis in Marek's disease virus infected hypercholesterolemic roosters is reduced by HMGCoA reductase and ACE inhibitor therapy

OBJECTIVES

Accelerated atherosclerosis is associated with herpesviral infection both in transplant patients and after balloon angioplasty. Marek's disease virus (MDV) is a herpesvirus that induces accelerated atherosclerosis associated with the development of an invasive lymphoma in hyperlipemic roosters. We have examined the effects of pravastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A (HMGCoA) reductase inhibitor and quinapril, an angiotensin converting enzyme (ACE) inhibitor, on atherosclerosis development in MDV infected, cholesterol fed rooster chicks.

METHODS

The effects of these drugs on plaque growth after MDV infection were examined in two studies. In Study 1, MDV infected White Leghorn rooster chicks were divided into 4 groups assigned to normal or high cholesterol diet, and treated at three months of age with either pravastatin or saline. In Study 2, cholesterol fed rooster chicks infected with MDV were divided into 3 groups for treatment with either pravastatin, quinapril, or saline control.

RESULTS

A significant decrease in plaque area was detected after 60 days of treatment with both pravastatin and quinapril in cholesterol fed chicks (P < 0.001). Lymphocyte infiltration into the arterial wall or target organs was not inhibited by treatment with either drug.

CONCLUSIONS

(1) HMGCoA reductase inhibitor and ACE inhibitor therapy reduce atherosclerosis induced by virus infection and cholesterol diet, but this decrease in plaque growth is not due to a reduction in lymphocyte invasion. (2) MDV infection in cholesterol fed roosters provides a model for virus-induced arterial injury in atherogenesis.

Calreticulin, a potential vascular regulatory protein, reduces intimal hyperplasia after arterial injury

Both thrombotic and inflammatory responses to arterial injury have been implicated in atherosclerotic plaque growth. Calreticulin is a ubiquitous calcium-binding protein with antithrombotic activity and, in addition, is associated with leukocyte activation. We are investigating calreticulin as a potential vascular regulatory protein. The development of intimal hyperplasia was studied at sites of balloon injury in iliofemoral arteries from 91 rats. Calreticulin was infused directly into the artery immediately before balloon injury, and plaque growth was then assessed at 4 weeks' follow-up. Parallel studies of the effects of each calreticulin domain as well as a related calcium-binding protein, calsequestrin, were examined. The effects of calreticulin on platelet activation, clot formation, and mononuclear cell migration were also studied. When infused before balloon injury in rat iliofemoral arteries, calreticulin, or its high-capacity Ca(2+)-binding C domain, significantly reduces plaque development, whereas calsequestrin, a related calcium-binding protein that lacks the multifunctional nature of calreticulin, does not decrease plaque area (saline: 0.037 +/- 0.007 mm2, calsequestrin: 0.042 +/- 0.021 mm2, calreticulin: 0.003 +/- 0.002 mm2, n = 46, P < .04). The N domain and more specifically the P domain, a low-capacity, high-affinity calcium-binding domain in calreticulin, do not reduce intimal hyperplasia (N + P domain: 0.038 +/- 0.012 mm2, C domain: 0.003 +/- 0.002 mm2, n = 45 rats, P < .0001). Calreticulin reduces macrophage and T cell staining in the arterial wall after injury but has no direct effect on monocyte migration in vitro (percent medial area staining positive for macrophage 24 hours after injury (N + P: 4.06 +/- 1.42, calreticulin: 0.273 +/- 0.02; n = 26, P < .009). Calreticulin does, however, reduce platelet-dependent whole blood clotting time, in vitro (baseline: 78.23 +/- 2.04 seconds, calreticulin: 113.5 +/- 1.95 seconds; n = 5, P < .002). We conclude that calreticulin significantly reduces intimal hyperplasia after arterial injury, potentially acting as a vascular regulatory protein.

Organic vapor sensors based on SAW resonator and organic films

The majority of investigations of SAW devices used as chemical sensors are based on delay line oscillators. However, SAW resonator oscillator offers some advantages over the SAW delay line oscillator for its higher stability. In the incipient stage of fabricating gas sensors based upon SAW resonator, taking detection of organic vapor as an example, the analysis method that combines the SAW theory with organic film technology has been adopted to give an intensive insight into the responses of two-port SAW resonator coated with LB-film and cast-film after exposure to organic vapors.

Virus-encoded serine proteinase inhibitor SERP-1 inhibits atherosclerotic plaque development after balloon angioplasty

BACKGROUND

Recurrent atherosclerotic plaque growth, restenosis, is a significant clinical problem after interventional procedures. Initiation of restenosis involves activation of inflammatory and thrombotic cascades, which are regulated by serine proteinase enzymes and inhibitors. We have investigated the use of a viral serine proteinase inhibitor, SERP-1, to reduce plaque development after primary balloon angioplasty. This is the first experimental report of the use of a viral anti-inflammatory protein for the prevention of atherosclerosis.

METHODS AND RESULTS

Seventy-four cholesterol-fed rabbits were treated with either local or systemic infusions of SERP-1 protein (or control solutions) after balloon-mediated injury. Sites of SERP-1 infusion in rabbits had dramatically reduced plaque compared with control infusions at the 4-week follow-up. At low-dose infusions (30 to 300 pg), only the primary infusion site had a demonstrable decrease in plaque, whereas at higher-dose infusions (> 3000 pg), a generalized reduction in plaque development was detected. An associated decrease in mononuclear cell infiltration of the arterial wall was detected after SERP-1 infusion within the first 24 hours. Infusion of an active-site mutant of SERP-1 (P1-P1', ala-ala) lacking serine proteinase inhibitory activity failed to prevent plaque growth.

CONCLUSIONS

Purified SERP-1, a virus-encoded secreted glycoprotein, reduces plaque growth after primary balloon-mediated injury. Plaque development is decreased by inhibition of serine proteinase activity and is associated with a focal reduction in macrophage infiltration immediately after injury. Investigation of serine proteinase inhibitors may provide new insight into the regulation of arterial responses to injury.

Development of an avian model for restenosis

Recurrence of atherosclerotic plaque growth after interventional therapy, restenosis, is a significant clinical problem occurring in 20%-50% of cases. We have developed a new avian model for the investigation of restenosis after arterial injury in cholesterol fed White Leghorn roosters. Atherosclerotic plaque growth 1-30 weeks after angioplasty balloon mediated endothelial injury in the abdominal aorta was studied in 37 roosters. Roosters were maintained on either normal poultry diet or high cholesterol diet. Twelve cholesterol fed roosters were also fed a hormone supplemented diet in order to modify plaque morphology. The procedural success rate was high. Angiographic stenoses (mean 36% with maximum of 74%) were detectable in cholesterol fed roosters after balloon angioplasty with associated histological evidence of plaque growth (P < 0.017). Cholesterol feeding enhanced fatty plaque growth; hormone manipulation increased calcific and ulcerated plaque but with high associated morbidity. Three interventional devices were subsequently examined in 32 roosters (16 laser angioplasty, 7 atherectomy, and 9 stent implant). Plaque development was again assessed by contrast angiography and histological analysis. We conclude that balloon mediated arterial injury in cholesterol fed roosters produces early proliferative and late, complex atherosclerotic lesions providing an inexpensive model for plaque development after intimal injury.