Acoustic Activation Imaging With Intravenous Perfluoropropane Nanodroplets Results in Selective Bioactivation of the Risk Area.

BACKGROUND: Acoustically activatable perfluoropropane droplets (PD) can be formulated from commercially available microbubble preparations. Diagnostic transthoracic ultrasound frequencies have resulted in acoustic activation (AA) predominately within myocardial infarct zones (IZ). OBJECTIVE: We hypothesized that the AA area following acute coronary ischemia/reperfusion (I/R) would selectively enhance the developing scar zone, and target bioeffects specifically to this region. METHODS: We administered intravenous PD in 36 rats and 20 pigs at various stages of myocardial scar formation (30 minutes, 1 day, and 7 days post I/R) to determine what effect infarct age had on the AA within the IZ. This was correlated with histology, myeloperoxidase activity, and tissue nitrite activity. RESULTS: The degree of AA within the IZ in rats was not associated with collagen content, neutrophil infiltration, or infarct age. AA within 24 hours of I/R was associated with increased nitric oxide utilization selectively within the IZ (P < .05 compared with remote zone). The spatial extent of AA in pigs correlated with infarct size only when performed before sacrifice at 7 days (r = .74, P < .01). CONCLUSIONS: Acoustic activation of intravenous PD enhances the developing scar zone following I/R, and results in selective tissue nitric oxide utilization.

Characterization of COVID-19-associated cardiac injury: evidence for a multifactorial disease in an autopsy cohort.

As the coronavirus disease 2019 (COVID-19) pandemic evolves, much evidence implicates the heart as a critical target of injury in patients. The mechanism(s) of cardiac involvement has not been fully elucidated, although evidence of direct virus-mediated injury, thromboembolism with ischemic complications, and cytokine storm has been reported. We examined suggested mechanisms of COVID-19-associated heart failure in 21 COVID-19-positive decedents, obtained through standard autopsy procedure, compared to clinically matched controls and patients with various etiologies of viral myocarditis. We developed a custom tissue microarray using regions of pathological interest and interrogated tissues via immunohistochemistry and in situ hybridization. Severe acute respiratory syndrome coronavirus 2 was detected in 16/21 patients, in cardiomyocytes, the endothelium, interstitial spaces, and percolating adipocytes within the myocardium. Virus detection typically corresponded with troponin depletion and increased cleaved caspase-3. Indirect mechanisms of injury-venous and arterial thromboses with associated vasculitis including a mixed inflammatory infiltrate-were also observed. Neutrophil extracellular traps (NETs) were present in the myocardium of all COVID-19 patients, regardless of injury degree. Borderline myocarditis (inflammation without associated myocyte injury) was observed in 19/21 patients, characterized by a predominantly mononuclear inflammatory infiltrate. Edema, inflammation of percolating adipocytes, lymphocytic aggregates, and large septal masses of inflammatory cells and platelets were observed as defining features, and myofibrillar damage was evident in all patients. Collectively, COVID-19-associated cardiac injury was multifactorial, with elevated levels of NETs and von Willebrand factor as defining features of direct and indirect viral injury.

Diagnostic performance of 2D-shear wave elastography and serum fibrosis markers for evaluation of hepatic graft fibrosis in pediatric liver-inclusive transplant recipients: A prospective pilot study.

BACKGROUND: Liver biopsy is the gold standard for hepatic fibrosis staging, but it is invasive and has potential severe complications. We aimed to determine the diagnostic performance of 2D-SWE and serum markers to predict significant hepatic graft fibrosis (≥F2) in pediatric liver-inclusive transplant recipients. METHODS: This prospective, cross-sectional pilot study included children younger than 19 years who had received a LT or LSBT and underwent a liver biopsy performed for clinical indications. LS was measured using 2D-SWE. The AUROC was calculated to evaluate the diagnostic performance of 2D-SWE and biomarkers (AST/ALT ratio, APRI, FIB4) for predicting significant fibrosis. RESULTS: Twenty-two children (13 males, 8 LSBT) were included. Eighteen (81.8%) children received a whole liver graft. Thirteen (59.1%) patients had hepatic fibrosis (≥F1) and four (18.2%) had significant fibrosis. The AUROCs of AST/ALT ratio, APRI, and FIB4 for predicting significant hepatic graft fibrosis were 0.71 (p = .29), 0.85 (p = .0001), and 0.76 (p = .03), respectively. When FIB4 was calculated using the hepatic graft's age, its AUROC improved to 0.85 (p < .0001). The AUROC of 2D-SWE for predicting significant hepatic graft fibrosis was 0.80 (p = .046). When 2D-SWE was combined with APRI or FIB4, its AUROC improved to 0.82 (p = .08) and 0.87 (p = .002), respectively. CONCLUSIONS: APRI and FIB4 can accurately predict significant hepatic graft fibrosis. 2D-SWE may serve as a valuable adjunct tool to detect significant graft fibrosis, especially when combined with these serum markers.

Post-transplant hepatic fibrosis in pediatric liver-small bowel transplant recipients: A single-center, retrospective, observational study.

BACKGROUND: Little is known about the prevalence of hepatic graft fibrosis in combined LSBT children. We aimed to determine the prevalence of and identify potential predictors for hepatic graft fibrosis in LSBT children and to compare them with those in LT children. METHODS: We retrospectively included children younger than 19 years who had received a primary LT/LSBT between 2000 and 2018 and had a liver biopsy performed at least 6 months post-transplant. A Cox proportional hazards regression model was used to determine predictors associated with significant hepatic graft fibrosis (≥F2) in LSBT vs LT children. RESULTS: Ninety-six children (47 LSBT, 54 females) were included. The median post-transplant follow-up (years) was 12.8 in LT vs 10.5 in LSBT patients (P = .06). Hepatic graft fibrosis was found in 81.6% of LT vs 70.2% of LSBT children (P = .19), after a median time of 2.5 years and 2.6 years, respectively. On multivariate analyses, having post-transplant biliary complications was found to be associated with significant graft fibrosis in LT children, whereas AST/ALT ratio was found to predict significant hepatic graft fibrosis in LSBT children. The use of parenteral nutrition after transplant was not associated with significant hepatic graft fibrosis. CONCLUSIONS: The prevalence of hepatic graft fibrosis in LSBT children did not significantly differ from that in LT children, but the predictors may differ. Future studies should investigate the role of post-transplant autoimmune antibodies and donor-specific antibodies in the development and progression of hepatic graft fibrosis in LSBT children.

Sirolimus for Recurrent Giant Cell Myocarditis After Heart Transplantation: A Unique Therapeutic Strategy.

CLINICAL FEATURES: Giant cell myocarditis (GCM) is a rare and a rapidly progressive disorder with fatal outcomes such that patients often require heart transplantation. We present a case of recurrent GCM in a transplanted patient with a history of Crohn disease requiring a novel therapeutic approach. THERAPEUTIC CHALLENGE: After the orthotopic heart transplantation, GCM recurred on aggressive immunosuppression over the months, which included corticosteroids, basiliximab, tacrolimus, antithymocyte globulin, and rituximab. Although combination immunosuppressive therapy containing cyclosporine and 2-4 additional drugs including corticosteroids, azathioprine, mycophenolate mofetil, muromonab, gammaglobulin, or methotrexate have shown to prolong the transplant-free survival by keeping the disease under control, its role in preventing and treating recurrence posttransplantation is unclear. SOLUTION: We added sirolimus, a macrolide antibiotic, with properties of T- and B-lymphocyte proliferation inhibition on the above immunosuppressive treatment postrecurrence of GCM. After sirolimus initiation and continuation, the patient has remained disease free.

Effect of Ambient Conditions on Acoustic Activation of the Perfluoropropane Droplets Within the Infarct Zone.

BACKGROUND: Acoustically activated perfluoropropane droplets (PD) formulated from lipid encapsulated microbubble preparations produce a delayed myocardial contrast enhancement that preferentially highlights the infarct zones (IZ). Since activation of PDs may be temperature sensitive, it is unclear what effect body temperature (BT) has on acoustic activation (AA). OBJECTIVE: We sought to determine whether the microvascular retention and degree of myocardial contrast intensity (MCI) would be affected by BT at the time of intravenous injection. METHODS: We administered intravenous (IV) PD in nine rats following 60 min of ischemia followed by reperfusion. Injections in these rats were given at temperatures above and below 36.5°C, with high MI activation in both groups at 3 or 6 min following IV injection (IVI). In six additional rats (three in each group), IV PDs were given only at one temperature (<36.5°C or ≥36.5°C), permitting a total of 12 comparisons of different BT. Differences in background subtracted MCI at 3-6 min post-injection were compared in the infarct zone (IZ) and remote zone (RZ). Post-mortem lung hematoxylin and eosin (H&E) staining was performed to assess the effect potential thermal activation on lung tissue. RESULTS: Selective MCI within the IZ was observed in 8 of 12 rats who received IVI of PDs at <36.5°C, but none of the 12 rats who had IVI at the higher temperature (p < 0.0001). Absolute MCI following droplet activation was significantly higher in both the IZ and RZ when given at the lower BT. H&E indicated significant red blood extravasation in 5/7 rats who had had IV injections at higher BT, and 0/7 rats who had IV PDs at <36.5°C. CONCLUSIONS: Selective IZ enhancement with AA of intravenous PDs is possible, but temperature sensitive. Thermal activation appears to occur when PDs are given at higher temperatures, preventing AA, and increasing unwanted bioeffects.

Buerger's Disease in the Testicle: A Case of Testicular Thromboangiitis Obliterans.

Thromboangiitis obliterans (TAO), otherwise known as Buerger's disease, is a rare, non-atherosclerotic inflammatory vasculopathy that typically affects small and medium-sized arteries of the distal extremities. Smoking is believed to be integral to the pathogenesis, as TAO primarily affects young male smokers. The disease is characterized by extremity pain secondary to ischemia that may progress to ulceration, gangrene, and amputation. Involvement of the reproductive system is uncommon. Here, we offer a case of TAO presenting as a testicular mass lesion.

Sudden cardiac death in the young: A consensus statement on recommended practices for cardiac examination by pathologists from the Society for Cardiovascular Pathology.

Sudden cardiac death is, by definition, an unexpected, untimely death caused by a cardiac condition in a person with known or unknown heart disease. This major international public health problem accounts for approximately 15-20% of all deaths. Typically more common in older adults with acquired heart disease, SCD also can occur in the young where the cause is more likely to be a genetically transmitted process. As these inherited disease processes can affect multiple family members, it is critical that these deaths are appropriately and thoroughly investigated. Across the United States, SCD cases in those less than 40 years of age will often fall under medical examiner/coroner jurisdiction resulting in scene investigation, review of available medical records and a complete autopsy including toxicological and histological studies. To date, there have not been consistent or uniform guidelines for cardiac examination in these cases. In addition, many medical examiner/coroner offices are understaffed and/or underfunded, both of which may hamper specialized examinations or studies (e.g., molecular testing). Use of such guidelines by pathologists in cases of SCD in decedents aged 1-39 years of age could result in life-saving medical intervention for other family members. These recommendations also may provide support for underfunded offices to argue for the significance of this specialized testing. As cardiac examinations in the setting of SCD in the young fall under ME/C jurisdiction, this consensus paper has been developed with members of the Society of Cardiovascular Pathology working with cardiovascular pathology-trained, practicing forensic pathologists.

Virtual microscopy in cytotechnology education: Application of knowledge from virtual to glass.

BACKGROUND: Virtual microscopy (VM) is a technology in which the glass slides are converted into digital images. The main objective of this study is to determine if cellular morphology, learned through virtual microscopy, can be applied to glass slide screening. MATERIALS AND METHODS: A total of 142 glass slides (61 teaching and 81 practice) of breast, thyroid, and lymph node fine needle aspiration body sites were scanned with a single focal plane (at 40X) using iScanCoreo Au (Ventana, Tuscan, AZ, USA, formerly known as BioImagene, California, USA). Six students including one distant student used these digital images to learn cellular morphology and conduct daily screening. Subsequently, all the students were tested on 10 glass slides using light microscopy (LM). At the end of the study, the students were asked to respond to an online survey on their virtual microscopy experience. The glass slide screening test scores of the participating students who were taught through VM and tested on glass slides (VMLM group) were compared with the last three classes of students who were taught through LM and tested on glass slides (LMLM group). RESULTS: A non-parametric statistical analysis indicated no difference (P = 0.20) in the glass screening test scores between VMLM (median = 93.5) and LMLM groups (median = 87). The survey indicated that the annotated teaching slides and access to the VM, off campus, were well appreciated by the students. CONCLUSIONS: Although the students preferred LM, they were able to apply the cytological criteria learned through VM to glass slide screening. Overall, VM was considered a great teaching tool.

Hydroxychloroquine and Fabry Disease: Three Case Reports Examining an Unexpected Pathologic Link and a Review of the Literature.

Background: Hydroxychloroquine is an effective and widely used treatment in multiple autoimmune connective tissue diseases that gained a lot of publicity in the coronavirus disease 2019 (COVID-19) pandemic. Our case reports are unique in that they explore the rare and sometimes overlooked effects of this drug on multiple organ systems, specifically the kidney, cardiac muscle, and skeletal muscle. We include key histologic features in images which aid in identifying and distinguishing hydroxychloroquine toxicity from mimickers. Lastly, we report the very interesting similarity in the intracellular action of hydroxychloroquine to the pathology of Fabry disease (and its associated lysosomal enzyme, α-galactosidase A). Case Presentation. We will examine the case presentations of three female Caucasian patients: a 22-year-old with lupus nephritis class V, a 72-year-old with long-standing systemic lupus erythematosus, and a 74-year-old with undifferentiated connective tissue disease. All three patients were on hydroxychloroquine therapy for varying amounts of time with histologic evidence of hydroxychloroquine toxicity that is three is present in histological samples of the kidney, the heart, and the skeletal muscle. Conclusions: Hydroxychloroquine is a very important and beneficial medication used for various autoimmune connective tissue diseases. Clinicians should be aware of the rare but sometimes serious side effects that can result from the medication, which at times can mimic manifestations of the connective tissue disease itself or Fabry disease. A thorough investigation should be performed in these cases to properly elucidate the cause followed by the appropriate targeted therapy.

Pulmonary Hypertensive Changes Secondary to COVID-19 Pneumonia in a Chronically SARS-CoV-2-Infected Bilateral Lung Explant.

COVID-19, the syndrome caused by the novel coronavirus SARS-CoV-2, has spread throughout the world, causing the death of at least three million people. For the over 81 million who have recovered, however, the long-term effects are only beginning to manifest. We performed a bilateral lung transplant on a 31-year-old male patient for chronic hypoxic respiratory failure, severe pulmonary hypertension and radiographically identified pulmonary fibrosis five months after an acute COVID-19 infection. The explant demonstrated moderate pulmonary vascular remodeling with intimal thickening and medial hypertrophy throughout, consistent with pulmonary hypertension. The parenchyma demonstrated an organizing lung injury in the proliferative phase, with severe fibrosis, histiocytic proliferation, type II pneumocyte hyperplasia, and alveolar loss consistent with known COVID-19 pneumonia complications.This report highlights a novel histologic finding in severe, chronic COVID-19. Although the findings in acute COVID-19 pneumonia have been well-examined at autopsy, the chronic course of this complex disease is not yet understood. The case presented herein suggests that COVID-induced pulmonary hypertension may become more common as more patients survive severe SARS-CoV-2-related pneumonia. Pulmonologists and pulmonary pathologists should be aware of this possible association and look for the clinical, radiographic, and histologic criteria in the appropriate clinical setting.

Intraventricular Septation in the Context of Dilated Cardiomyopathy Associated With TTN Mutation.

A 6-month-old infant boy presented with symptomatic heart failure. Dilated cardiomyopathy was found in association with a mutation in TTN. Structural heart disease included novel septation of the left ventricle with a fenestrated membrane resulting from aberrant congenital mitral valve apparatus formation. (Level of Difficulty: Advanced.).

Autoimmune hepatitis induced by syngeneic liver cytosolic proteins biotransformed by alcohol metabolites.

BACKGROUND AND AIMS: Aldehydes that are produced following the breakdown of ethanol (acetaldehyde) and lipid peroxidation of membranes (malondialdehyde) have been shown to bind (adduct) proteins. Additionally, these two aldehydes can combine (MAA) on nonsyngeneic and syngeneic proteins to initiate numerous immune responses to the unmodified part of the protein in the absence of an adjuvant. Therefore, these studies provide a potential mechanism for the development of antigen-specific immune responses resulting in liver damage should syngeneic liver proteins be adducted with MAA. METHODS: This study sought to test whether MAA-modified syngeneic liver cytosolic proteins administered daily in the absence of adjuvant into C57BL/6 mice abrogates tolerance to initiate a MAA-induced autoimmune-like hepatitis. RESULTS: In mice immunized with MAA-modified cytosols, there was an increase in liver damage as assessed by aspartate aminotransferase/alanine aminotransferase levels that correlated with liver pathology scores and the presence of the pro-fibrotic factors, smooth muscle actin, TGF-ß, and collagen. IgG antibodies and T-cell proliferative responses specific for cytosolic proteins were also detected. Pro-inflammatory cytokines were produced in the livers of animals exposed to MAA-modified cytosols. Finally, transfer of immunized T cells to naïve animals caused biochemical and histological evidence of liver damage. CONCLUSIONS: These data demonstrate that a disease with an autoimmune-like pathophysiology can be generated in this animal model using soluble MAA-modified syngeneic liver cytosols as the immunogen. These studies provide insight into potential mechanism(s) that the metabolites of alcohol may play in contributing to the onset of an autoimmune-like disease in patients with alcoholic liver disease.

Evaluation of cellular ingrowth within porcine extracellular matrix scaffolding in congenital heart disease surgery.

The search for an ideal material for cardiac tissue repair has led to utilization of porcine small intestinal submucosa extracellular matrix (CorMatrix). Here, we examine the histologic features of CorMatrix and the associated cellular growth at a variety of time intervals. Tissues with CorMatrix from ten patients (4 male, 6 female) with ages ranging from 2 weeks to 2 years, and implant duration ranging from 1 week to 2 years were included in this study. Samples for analysis were collected at autopsy. Surgical repair sites included great vessel repair (n=9), atrial septum defect (n=1), coronary vessels (n=1), as well as aortic (n=1) and mitral valve (n=2) leaflets. In all specimens, CorMatrix was composed of dense laminated regions of collagen, without appreciable elastin staining. In most grafts, especially those implanted for extended periods of time, tissue with luminal CD31 positivity covered the intimal surface of the CorMatrix graft. This tissue (neo-intima) consisted of spindled myofibroblasts (SMA) and small CD31 positive vessels with occasional mononuclear cells in a matrix composed of collagen, glycosaminoglycans, and rarely elastin, after extended periods of implantation. These features were readily identified in patients as early as 1 month after CorMatrix implantation. The matrix comprising the CorMatrix itself remained largely acellular, despite implantation times up to 2 years, with degradation of the graft material. We provide a framework for histologic expectations when evaluating explanted CorMatrix grafts. In this regard, the CorMatrix matrix is likely to remain acellular without significant elastin deposition, whereas the intimal and adventitial surfaces become coated by proliferating cells in a novel matrix of collagen and glycosaminoglycans.

Loss of the PTCH1 gene locus in cardiac fibroma.

BACKGROUND: Cardiac fibroma (CF) is a rare benign tumor that is poorly characterized genetically. CF is more commonly encountered in patients with Gorlin syndrome (3%) than the general population. Mutations of the tumor suppressor gene PTCH1 are the underlying cause of Gorlin syndrome. METHODS: Conventional cytogenetic analysis was performed on a peripheral blood and a CF sample from a 2-week-old male. In addition, fluorescence in situ hybridization (FISH) studies were performed to assess the copy number of the PTCH1 gene locus (9q22.3) on metaphase and interphase cells from these same specimens using yeast artificial protein (YAC) probe 891G1 and on representative paraffin-embedded tissue sections of two additional CFs (one arising in a 2-month-old female and the other in a 13-week-old male). None of the patients had Gorlin syndrome. RESULTS: Karyotypically, the following abnormal chromosomal complement was detected in the 2-week-old male's CF: 46,XY,del(9)(q22q34)[15]. FISH studies revealed homozygous loss of the PTCH1 locus in the cytogenetically analyzed CF and in the CF arising in the 13-week-old male. Heterozygous loss of this locus was identified in the remaining CF from the 2-month-old female. A mutational mechanism other than deletion may be responsible for PTCH1 inactivation on the other locus in this latter patient. Conventional cytogenetic and FISH studies of the peripheral blood sample from the 2-week-old male were normal. CONCLUSION: These data support a tumor suppressor gene role for PTCH1 in nonsyndromic or sporadic CFs.

The role of complement in the adherence of microbubbles to dysfunctional arterial endothelium and atherosclerotic plaque.

OBJECTIVE: To determine whether serum complement C3 mediates adherence of albumin-encapsulated microbubbles to vascular endothelium in the development of atherosclerotic plaques. METHODS: Adherence of microbubbles to aortic endothelium was examined with scanning electron microscopy following intravenous injection of 20% intralipid in wild-type mice, genetic complement-deficient mice (C3-/-), and in pharmacologic C3-depleted wild-type mice. In a second experimental model, atherosclerostic plaque was induced in apolipoprotein E-deficient mice (apoE-/-), and adherence of microbubbles to atherosclerotic plaques was evaluated using fluorescent microscopy of fluorescein isothiocynate-conjugated microbubbles. Finally, imaging of aortas was performed in eight rats (four JCR:LA-cp atherosclerosis-prone rats on high cholesterol diets; four controls) following intravenous albumin microbubble injections (PESDA) to determine whether microbubble adherence to the endothelium could be detected with low mechanical index pulse sequence schemes. RESULTS: Scanning electron microscopy confirmed the adherence of microbubbles to the endothelial cells of the aorta in wild-type mice following induction of hypertriglyceridemia but not in C3-depleted mice. Microbubble adherence to the endothelial surface of atherosclerotic plaque was confirmed in all apoE-/- mice (median 172 microbubbles/field; compared to a median of 3 microbubbles/field in cobra venom factor-treated apoE-/- mice; p < 0.001). Low mechanical index ultrasound imaging detected microbubble adherence in all JCR atherosclerosis prone rats even in the absence of vasomotor or phenotypical evidence of endothelial dysfunction. The numbers of adherent microbubbles correlated with serum triglyceride levels, and were seen in conjunction with increased endothelial nitric oxide synthase activity. CONCLUSIONS: Complement C3 binds to albumin-encapsulated microbubbles and mediates microbubble adherence to vascular endothelium both early and late in the atherosclerotic process.

Location and structure of fibrous sheath formed after placing a tunneled hemodialysis catheter in a large pig model.

BACKGROUND AND OBJECTIVES: We evaluated the location and structure of the fibrous sheath formed after the placement of tunneled, cuffed hemodialysis catheters in large animals, 70 kg pigs. We focused on describing the location of the fibrous sheath in relation to the catheter. Its location explains the fibrous sheath's ability to cause catheter dysfunction by covering the catheter exit ports located at the catheter's tip. DESIGN: We used three animals. Each animal had a tunneled, cuffed, 15-French diameter hemodialysis catheter placed in the external jugular vein, with the tip at the junction of the superior vena cava and the right atrium. Two animals were sacrificed at 5 weeks and one animal at 17 weeks after catheter placement. The catheter and surrounding tissues were removed in one block. The fibrous sheath was dissected and longitudinally cut along the catheter to evaluate its extension in relation to the catheter. Relevant portions of the fibrous sheath were sent for pathology examination. RESULTS: The fibrous sheath covered the catheter in its entire length and circumference. It started at the entry site and continued without any interruption along the entire length of the catheter, including the tip. Its average thickness is 1 mm and has an inner cellular/inflammatory layer comprising lymphocytes, plasma cells, neutrophils, macrophages, multinucleated giant cells, and spindled cells and an outer layer comprising a mixture of collagen and fibroblasts. CONCLUSION: Our model showed that the fibrous sheath forms around all catheters and covers them in their entire length and circumference without any gaps.

Targeted vascular delivery of antisense molecules using intravenous microbubbles.

OBJECTIVE: Perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microbubbles bind the antisense to the c-myc protooncogene (anti-c-myc) which prevents neointimal hyperplasia following vascular endothelial injury. The microbubbles also adhere to sites of damaged vascular endothelium and thus may be a method of systemically targeting delivery of anti-c-myc. METHODS: Laser scanning microscopy was performed on the aorta of 10 mice (five which were complement depleted) that received intravenous FITC-PESDA following aortic endothelial injury. C-myc expression was quantified following selective intracoronary injury in nine pigs that received intravenous (IV) anti-c-myc bound to PESDA. Finally, neointimal formation was measured following intracoronary stent deployment in 30 pigs that received either IV anti-c-myc alone or the same dose bound to PESDA. RESULTS: Fluorescent microscopy confirmed selective PESDA microbubble adherence to aortic endothelium in all mice with aortic injury. This binding was nearly abolished when serum complement was depleted prior to injury. C-myc expression at the site of coronary endothelial injury was significantly lower in pigs treated with systemic anti-c-myc bound to PESDA. There was a 33% reduction in % stenosis and a 28% reduction in intimal area at 45 days post-stent deployment in pigs that received IV antisense plus PESDA. The stent margins also had reduced neointimal formation. CONCLUSION: Systemic administration of anti-c-myc bound to PESDA microbubbles may be a good method for preventing coronary neointimal formation within and around implanted stents.