Expression of fibroblast activation protein-α in human deep vein thrombosis.

BACKGROUND: Fibroblast activation protein-α (FAP), a type-II transmembrane serine protease, is associated with wound healing, cancer-associated fibroblasts, and chronic fibrosing diseases. However, its expression in deep vein thrombosis (DVT) remains unclear. Therefore, this study investigated FAP expression and localization in DVT. METHODS: We performed pathological analyses of the aspirated thrombi of patients with DVT (n = 14), classifying thrombotic areas in terms of fresh, cellular lysis, and organizing reaction components. The organizing reaction included endothelialization and fibroblastic reaction. We immunohistochemically examined FAP-expressed areas and cells, and finally analyzed FAP expression in cultured dermal fibroblasts. RESULTS: All the aspirated thrombi showed a heterogeneous mixture of at least two of the three thrombotic areas. Specifically, 83 % of aspirated thrombi showed fresh and organizing reaction components. Immunohistochemical expression of FAP was restricted to the organizing area. Double immunofluorescence staining showed that FAP in the thrombi was mainly expressed in vimentin-positive or α-smooth muscle actin-positive fibroblasts. Some CD163-positive macrophages expressed FAP. FAP mRNA and protein levels were higher in fibroblasts with low-proliferative activity cultured under 0.1 % fetal bovine serum (FBS) than that under 10 % FBS. Fibroblasts cultured in 10 % FBS showed a significant decrease in FAP mRNA levels following supplementation with hemin, but not with thrombin. CONCLUSIONS: The heterogeneous composition of venous thrombi suggests a multistep thrombus formation process in human DVT. Further, fibroblasts or myofibroblasts may express FAP during the organizing process. FAP expression may be higher in fibroblasts with low proliferative activity.

Elevated plasma levels of factor VIII enhance arterial thrombus formation on erosive smooth muscle cell-rich neointima but not normal intima in rabbits.

BACKGROUND: Plaque erosion, a type of coronary atherothrombosis, involves superficial injury to smooth muscle cell (SMC)-rich plaques. Elevated levels of coagulation factor VIII (FVIII) correlate with an increased ischemic heart disease risk. FVIII may contribute to thrombus formation on eroded plaques. AIMS: We aimed to elucidate the role of elevated FVIII in arterial thrombus formation within SMC-rich neointima in rabbits. METHODS AND RESULTS: We assessed the effect of recombinant human FVIII (rFVIII) on blood coagulation in vitro and platelet aggregation ex vivo. An SMC-rich neointima was induced through balloon injury to the unilateral femoral artery. Three weeks after the first balloon injury, superficial erosive injury and thrombus formation were initiated with a second balloon injury of the bilateral femoral arteries 45 min after the administration of rFVIII (100 IU/kg) or saline. The thrombus area and contents were histologically measured 15 min after the second balloon injury. rFVIII administration reduced the activated partial thromboplastin time and augmented botrocetin-induced, but not collagen- or adenosine 5'-diphosphate-induced, platelet aggregation. While rFVIII did not influence platelet-thrombus formation in normal intima, it increased thrombus formation on SMC-rich neointima post-superficial erosive injury. Enhanced immunopositivity for glycoprotein IIb/IIIa and fibrin was observed in rFVIII-administered SMC-rich neointima. Neutrophil count in the arterial thrombus on the SMC-rich neointima correlated positively with thrombus size in the control group, unlike the rFVIII group. CONCLUSIONS: Increased FVIII contributes to thrombus propagation within erosive SMC-rich neointima, highlighting FVIII's potential role in plaque erosion-related atherothrombosis.

A 48-Year-Old Man Presenting as an Emergency with Severe Back Pain, a Large Anterior Paravertebral Hematoma, and Spontaneous Rupture of the Right 9th Intercostal Artery Successfully Managed by Transcatheter Arterial Embolization: A Case Report.

BACKGROUND The rupture of an intercostal artery is rare and is usually associated with trauma, neurofibromatosis type 1, or coarctation of the aorta. Transcatheter arterial embolization is a minimally invasive vascular surgical procedure used to control hemorrhage of an intercostal artery. This report describes a case of a 48-year-old man who presented with severe back pain. This was due to a large anterior paravertebral hematoma following the spontaneous rupture of the right 9th intercostal artery. The rupture was successfully managed by transcatheter arterial embolization. CASE REPORT A 48-year-old man suddenly felt severe back pain while walking. He had no previous medical history and he had not experienced any external injury. On arrival, he was tachycardic and hypertensive. He did not have abnormal physical findings. His chest radiograph, 12-lead electrocardiogram, ultrasonography, and blood test findings were unremarkable. A chest computed tomography scan with contrast media was performed, which revealed a 4.3×2.7×7.0 cm mass, enhanced with contrast media, anterior to the 9th vertebral body. The patient was diagnosed with spontaneous rupture of the right ninth intercostal artery. The lesion was embolized with 8 microcoils. The patient was discharged on the 8th hospital day without complications. CONCLUSIONS This report presents a rare case of the rupture of an intercostal artery in which no cause was identified. It highlights the role of imaging as an important diagnostic tool. Furthermore, this report shows the benefits of the timely use of emergency transcatheter arterial embolization, which in this instance resulted in a successful outcome.

Successful covered stent-graft treatment of superficial femoral arterial injury due to blunt trauma.

BACKGROUND: Endovascular treatment is used for traumatic arterial injuries in the torso. However, the effectiveness of endovascular covered stent-graft treatment for peripheral artery injury is unclear. We present a case of superficial femoral artery (SFA) injury successfully treated with a covered stent-graft. CASE REPORT: A 68-year-old man presented with traumatic lower limb injury and shock. Computed tomography angiography revealed left subtrochanteric fracture and hematoma with extravasation. Digital subtraction angiography revealed extravasation from a left SFA branch, and a pseudoaneurysm at the SFA trunk. We coil embolized the SFA branch, and treated the pseudoaneurysm with a covered stent-graft. Computed tomography carried out 22 days later showed complete pseudoaneurysm exclusion and sufficient stent patency. CONCLUSION: We successfully used a covered stent-graft to treat SFA injury due to blunt trauma. A covered stent-graft could be effective for peripheral artery injury.

Improving Thermodynamic Stability and Anticoagulant Activity of a Thrombin Binding Aptamer by Incorporation of 8-trifluoromethyl-2'-deoxyguanosine.

In this study, we incorporated 8-trifluoromethyl-2'-deoxyguanosine (FG) into a thrombin binding aptamer (TBA). Circular dichroism, nuclear magnetic resonance (NMR), electrophoresis, and prothrombin time (PT) assay were performed to investigate the structure, thermodynamic stability, biological stability, and anticoagulant activity of the FG-modified TBA sequences. We found that the replacement of FG into TBA sequences led to a remarkable improvement in the melting temperature up to 30 °C compared with the native sequence. The trifluoromethyl group allowed us to investigate the TBA G-quadruplex structure by 19F NMR spectroscopy. Furthermore, PT assays showed that the modified sequences can significantly improve the anticoagulant activity in comparison with the native TBA. Finally, we demonstrated that the trifluoromethyl-modified TBA sequence could function as an anticoagulant reagent in live rats. Our results strongly suggested that FG is a powerful nucleoside derivative to increase the thermodynamic stability and anticoagulant activity of TBA.

Therapeutic response of immunoglobulin 4-related aortitis and pancreatitis demonstrated by diffusion-weighted MRI.

Immunoglobulin (IgG) 4-related disease is a systemic inflammatory disease, and it affects vascular system as aortitis, periaortitis, or aneurysm. However, due to a lack of serum biomarker on aortic damage and the multiorgan involvement, it is difficult to assess aortic inflammatory activity of IgG4-related disease. We described a case of IgG4-related pancreatitis and aortitis, which was visualized with magnetic resonance merged image of diffusion weighted and T1 weighted images. The aortic signal intensity or apparent diffusion coefficient value reduced or increased after oral prednisone administration, respectively. Magnetic resonance diffusion weighted image and apparent diffusion coefficient may be a useful imaging tool for assessment of vascular inflammation in IgG4-related aortitis.

Higher lactate and purine metabolite levels in erythrocyte-rich fresh venous thrombus: Potential markers for early deep vein thrombosis.

BACKGROUND: Thrombolytic therapy is effective in fresh deep vein thrombosis (DVT) although the benefit may fall below the risk of bleeding in non-fresh thrombosis. Markers reflecting fresh DVT have not been established. The present study aims to identify metabolites reflecting fresh venous thrombus and their role in thrombus formation. METHODS: Metabolites of rabbit venous blood and jugular venous thrombus 4 h after thrombus induction were analysed using electrophoresis-time of flight mass spectrometry. The effects of the altered metabolites on blood coagulation and platelet aggregation were assessed by using rotation thromboelastometry and platelet aggregometer. Cellular contents and glucose transporter (Glut)-1 expression in aspirated human DVT samples were pathologically analysed. RESULTS: Metabolome analysis identified 226 metabolites (133 cationic and 93 anionic metabolites). Largely altered 18 metabolites (thrombus/blood ratio: >5 or <0.5) included glycolytic metabolites, redox-related metabolites, purine nucleotides and tryptophan metabolites. Among the metabolites with >5-fold increase, lactic acid was most abundant and guanine modestly enhanced whole blood clotting with thromboelastometry. Lactic acid and adenosine monophosphate inhibited collagen-induced platelet aggregation. Human DVTs were rich in erythrocytes expressing Glut-1. The erythrocyte content and Glut-1 expression were negatively correlated with the time after onset of DVT. CONCLUSIONS: Glycolysis-, purine-, and redox-related metabolites may reflect fresh erythrocyte-rich venous thrombus, and altered metabolites may affect venous thrombus formation. An increased level of lactate may reflect active glycolysis of thrombus cellular components, predominantly erythrocytes.

Efficient screening of patients with aldosterone-producing adenoma using the ACTH stimulation test.

Adrenal venous sampling (AVS) is the gold standard test for distinguishing between unilateral and bilateral primary aldosteronism (PA); however, AVS requires advanced and time consuming technique. The needs for AVS have been increasing due to the increased utilization of screening for PA. An efficient selection of unilateral PA, such as aldosterone-producing adenoma (APA), before AVS is useful to avoid undesirable AVS in bilateral PA, such as idiopathic hyperaldosteronism. In this study, 40 patients who received all three confirmatory tests, including the captopril challenge test, furosemide upright test and adrenocorticotropin (ACTH) stimulation test (AST), and who were diagnosed as having PA by AVS were recruited. Subjects were diagnosed as having unilateral aldosterone excess (n = 22) or bilateral aldosterone excess (n = 18) by AVS. All patients with unilateral PA underwent an operation and were finally diagnosed with APA. Major differences were detected in serum potassium level, basal plasma aldosterone concentration (PAC), presence of adrenal tumor, and AST results between the two groups. The PAC/cortisol ratio at 120 min in the AST showed the highest diagnostic capability for distinguishing the subtypes of PA according to a receiver operating characteristic (ROC) curve analysis (area under the ROC curve was 0.956). At a cutoff value of 1.20 for the PAC/cortisol ratio at 120 min on the AST, the sensitivity was 95.5%, and the specificity was 88.9%. This sufficiently high sensitivity suggests that the PAC/cortisol ratio at 120 min in the AST could be useful for the screening of patients with PA who are suitable for AVS.

Safe Resection of Renal Cell Carcinoma with Liver Invasion Using Liver Hanging Technique Supported by Preoperative Portal Vein Embolization.

In cases of RCC with liver involvement, partial hepatectomy is known to provide a better chance of survival for patients. For this reason, complete resection with clear surgical margin is thought to be necessary to achieve favorable outcome. Anterior liver hanging maneuver was extremely useful during hemihepatectomy in this rare type of RCC. A 63-year-old male was diagnosed with a large right renal cell carcinoma. The tumor measured 10 cm in diameter with tumor thrombus toward the inferior vena cava (IVC). In addition, we observed direct infiltration to the liver. We attempted a preoperative portal vein embolization (PVE) to preserve residual liver volume and function after right lobectomy. After PVE the resected volume decreased from 921 cm3 (71%) to 599 cm3 (53.4%). During the procedure, a nasogastric tube was placed in the retrohepatic space for liver hanging maneuver according to the original Belghiti's maneuver after dissection of the renal artery and vein. After hepatic parenchymal transection exposing vena cava, the right hepatic veins were safely transected using vascular stapler; right nephrectomy and hemihepatectomy were performed. The patient recovered without postoperative hepatic or urinary complications and has remained free of local recurrence and any de novo metastasis for 18 months.

Successful transarterial embolization with cellulose porous beads for occipital haemangioma in an infant with Kasabach-Merritt syndrome.

We report a 3-month-old boy with Kasabach-Merritt Syndrome (KMS) with an occipital haemangioma who underwent successful transarterial embolization (TAE) with cellulose porous beads (CPBs). As his response to steroids and coil embolization was inadequate, we performed TAE with CPBs, carefully preventing their migration via dangerous anastomoses. The tumour blush decreased, there were no complications, all coagulation tests were immediately normalized and the tumor size decreased gradually. TAE with CPBs is useful for the treatment of KMS.

CD163 macrophage and erythrocyte contents in aspirated deep vein thrombus are associated with the time after onset: a pilot study.

BACKGROUND: Thrombolytic therapy is effective in selected patients with deep vein thrombosis (DVT). Therefore, identification of a marker that reflects the age of thrombus is of particular concern. This pilot study aimed to identify a marker that reflects the time after onset in human aspirated DVT. METHODS: We histologically and immunohistochemically analyzed 16 aspirated thrombi. The times from onset to aspiration ranged from 5 to 60 days (median of 13 days). Paraffin sections were stained with hematoxylin and eosin and antibodies for fibrin, glycophorin A, integrin α2bß3, macrophage markers (CD68, CD163, and CD206), CD34, and smooth muscle actin (SMA). RESULTS: All thrombi were immunopositive for glycophorin A, fibrin, integrin α2bß3, CD68, CD163, and CD206, and contained granulocytes. Almost all of the thrombi had small foci of CD34- or SMA-immunopositive areas. CD68- and CD163-immunopositive cell numbers were positively correlated with the time after onset, while the glycophorin A-immunopositive area was negatively correlated with the time after onset. In double immunohistochemistry, CD163-positive cells existed predominantly among the CD68-immunopositive macrophage population. CD163-positive macrophages were closely localized with glycophorin A, CD34, or SMA-positive cell-rich areas. CONCLUSIONS: These findings indicate that CD163 macrophage and erythrocyte contents could be markers for evaluation of the age of thrombus in DVT. Additionally, CD163 macrophages might play a role in organization of the process of venous thrombus.

A synthetic tryptophan metabolite reduces hemorrhagic area and inflammation after pulmonary radiofrequency ablation in rabbit nonneoplastic lungs.

PURPOSE: The purpose of this study was to determine the effect of a synthetic tryptophan metabolite, tranilast [N-(3,4-dimethoxycinnamoyl)-anthranilic acid], on inflammatory and hemorrhagic areas after pulmonary radiofrequency ablation (RFA) in rabbits. MATERIALS AND METHODS: Percutaneous RFA using a 17-gauge LeVeen electrode was performed in normal rabbit lungs. The rabbits were divided into tranilast-treated (300 mg/kg/day, orally) and control groups (n = 24/group). The effects of tranilast were evaluated using multidetector-row computed tomography (CT), histology, and immunohistochemistry immediately after RFA on days 1, 7, 14, and 28. RESULTS: Oral administration of tranilast significantly reduced the size of ablated lesions assessed using CT and histology on days 7 and 14. Furthermore, it reduced the hemorrhagic areas on day 7 and inflammatory areas on day 14, but did not affect the areas of coagulation necrosis on days 1, 7, 14, and 28. Immunohistochemical analysis showed an increase in the ratio of CD163-positive macrophage areas to rabbit macrophage (RAM11)-positive pan-macrophage areas and a decrease in the number of nuclear factor-κB-positive nuclei and CD31-positive microvessels in the tranilast group on days 7 and/or 14. CONCLUSIONS: The results suggest that tranilast modulates the repair process after pulmonary RFA through macrophage accumulation, suppression of inflammation, and angiogenesis.

The usefulness of (18)F-FDG PET/MRI fusion image in diagnosing pancreatic tumor: comparison with (18)F-FDG PET/CT.

PURPOSE: This study aimed at demonstrating the feasibility of retrospectively fused (18)F FDG-PET and MRI (PET/MRI fusion image) in diagnosing pancreatic tumor, in particular differentiating malignant tumor from benign lesions. In addition, we evaluated additional findings characterizing pancreatic lesions by FDG-PET/MRI fusion image. METHODS: We analyzed retrospectively 119 patients: 96 cancers and 23 benign lesions. FDG-PET/MRI fusion images (PET/T1 WI or PET/T2WI) were made by dedicated software using 1.5 Tesla (T) MRI image and FDG-PET images. These images were interpreted by two well-trained radiologists without knowledge of clinical information and compared with FDG-PET/CT images. We compared the differential diagnostic capability between PET/CT and FDG-PET/MRI fusion image. In addition, we evaluated additional findings such as tumor structure and tumor invasion. RESULTS: FDG-PET/MRI fusion image significantly improved accuracy compared with that of PET/CT (96.6 vs. 86.6 %). As additional finding, dilatation of main pancreatic duct was noted in 65.9 % of solid types and in 22.6 % of cystic types, on PET/MRI-T2 fusion image. Similarly, encasement of adjacent vessels was noted in 43.1 % of solid types and in 6.5 % of cystic types. Particularly in cystic types, intra-tumor structures such as mural nodule (35.4 %) or intra-cystic septum (74.2 %) were detected additionally. Besides, PET/MRI-T2 fusion image could detect extra benign cystic lesions (9.1 % in solid type and 9.7 % in cystic type) that were not noted by PET/CT. CONCLUSIONS: In diagnosing pancreatic lesions, FDG-PET/MRI fusion image was useful in differentiating pancreatic cancer from benign lesions. Furthermore, it was helpful in evaluating relationship between lesions and surrounding tissues as well as in detecting extra benign cysts.

MR signal change in venous thrombus relates organizing process and thrombolytic response in rabbit.

Venous thrombus is subsequently organized and replaced by fibrous connective tissue. However, the sequential changes in venous thrombi are not reliably detected by current noninvasive diagnostic techniques. The purpose of this study is to reveal whether magnetic resonance (MR) can detect venous thrombus, define thrombus age and predict thrombolytic responses. Thrombus in the rabbit jugular vein was imaged with a 1.5-T MR system at 4 h and at 1, 2 and 4 weeks using three-dimensional (3D) fast asymmetric spin echo T2-weighted (T2W) and 3D-gradient echo T1-weighted (T1W) sequences. The jugular veins were histologically assessed at each time point. Magnetic resonance imaging (MRI) was also performed in vivo before and 30 min after tissue plasminogen activator (t-PA) administration. The thrombi in MRI were comparable in size to histological sections. The signal intensity (SI) of thrombi at 4 h was heterogeneously high or low on T2W or T1W images, respectively. The SI of thrombi on T2W images decreased time-dependently, but increased on T1W images at 1 and 2 weeks. Morphological analysis showed time-dependent decreases in erythrocyte, platelet and fibrin areas and time-dependent increases in smooth muscle cell, macrophage, collagen and iron areas. The t-PA administration significantly decreased thrombus volume at 4 h but not at 1, 2 and 4 weeks. Venous thrombosis can be reliably and noninvasively detected by MRI. Measurement of SI might support assessments of thrombus age and thrombolytic response.

Atherosclerotic lesions rich in macrophages or smooth muscle cells discriminated in rabbit iliac arteries based on T1 relaxation time and lipid content.

RATIONALE AND OBJECTIVES: Atherothrombosis usually occurs on macrophage- and lipid-rich unstable plaque, but rarely on smooth muscle cell (SMC)-rich stable plaque. Magnetic resonance imaging (MRI) has been extensively applied for noninvasive vascular imaging. We therefore investigated whether MRI provides valuable information about the characteristics of atherosclerotic vessels using rabbit models of macrophage-rich or SMC-rich atherosclerotic arteries. MATERIALS AND METHODS: Rabbits were fed with a conventional (CD group, n = 3) or 0.5% cholesterol (ChD group, n = 3) diet for 1 week before and 3 weeks after balloon injury of the left iliac arteries. Three weeks later, these arteries were investigates by 1.5 T MRI and by conventional angiographic imaging, followed by histological and immunohistochemical analyses. RESULTS: Three weeks after balloon injury, injured iliac arteries of both groups formed neointima with luminal stenosis. Conventional and MRI angiographic findings of the luminal diameter significantly and positively correlated. T1 relaxation time was significantly shorter and the lipid content was much higher in injured arteries from the ChD than from the CD group. The injured arteries from the ChD also contained more macrophages and less SMCs that those from the CD group. The T1 relaxation time and lipid content in injured arteries negatively and positively correlated with the degree of macrophage accumulation, respectively. CONCLUSION: These results showed that MRI could provide valuable information about luminal stenosis and the characteristics of atherosclerotic vessels in rabbits.

Factor VIII contributes to platelet-fibrin thrombus formation via thrombin generation under low shear conditions.

INTRODUCTION: Thrombus growth under low blood flow velocity plays an important role in the development of deep venous thrombosis (DVT). Increased plasma levels and activities of coagulation factor VIII (FVIII) comprise risk factors for DVT and pulmonary thromboembolism. OBJECTIVE: To localize FVIII in human venous thrombi of DVT and to determine whether FVIII contributes to thrombus formation under low shear conditions. METHODS: The localization of FVIII in venous thrombi obtained from patients with DVT was examined by immunohistochemistry. The role of FVIII in thrombus formation was investigated using a flow chamber system. Venous blood from healthy volunteers were incubated with an anti-FVIII monoclonal antibody (VIII-3776) or non-immunized mouse IgG(1). Blood samples were perfused on immobilized type III collagen at wall shear rates of 70/s and 400/s and then the surface area covered by platelets and fibrin was morphometrically evaluated. Prothrombin fragment 1+2 (PF1+2) generation was measured before and after perfusion. RESULTS: Venous thrombi of DVT comprised a mixture of platelets, fibrin and erythrocytes. Factor VIII appeared to be colocalized with glycoprotein IIb/IIIa, fibrin and von Willebrand factor in the thrombi. VIII-3776 specifically recognized the light chain of FVIII and prolonged the activated partial thromboplastin time (aPTT), but not prothrombin time (PT). The antibody significantly reduced platelets and fibrin covering, as well as PF1+2 generation at wall shear rates of 70/s and 400/s. CONCLUSIONS: These results suggest that FVIII contributes to platelet aggregation and fibrin formation via thrombin generation under low shear conditions.

Different inflammatory response and oxidative stress in neointimal hyperplasia after balloon angioplasty and stent implantation in cholesterol-fed rabbits.

Inflammatory responses appear to play an important role in the occurrence of restenosis following coronary intervention. However, the contribution of C-reactive protein (CRP) and oxidative stress to restenosis after balloon angioplasty and stent implantation remains unclear. The aim of this study was to examine this issue using hyperlipidemic rabbits. Rabbits were divided into two groups; they were fed with a 0.5% cholesterol diet and with a mixed 0.5% cholesterol and 0.5% probucol diet. Each group of rabbits underwent balloon injury and stent implantation in right and left iliac arteries, respectively. Eight weeks after the intervention, we examined luminal stenosis, neointimal hyperplasia, immunoreactivity for macrophage, CRP and oxidized phosphatidylcholine (oxPC), and also the expression of CRP mRNA. The degrees of neointimal hyperplasia and immunopositive areas (%) for macrophage, CRP, and oxPC in the neointima were significantly higher after stent implantation than after balloon injury, but CRP mRNA was undetectable in either artery. Anti-oxidant probucol reduced angiographic stenosis, neointimal hyperplasia, and macrophage- and oxPC-positive areas much more significantly after stenting. The results demonstrate that the inflammatory response to the development of neointimal hyperplasia differs after balloon injury and stent implantation and that CRP deposition and oxidative stress might be involved more significantly in neointimal development after stent implantation.