First reported long-term two- and three-dimensional echocardiographic follow-up with histopathological analysis of a transcatheter pulmonary valve implantation in a pet dog.

Transcatheter pulmonary valve implantation (TPVI) is indicated for use in the management of failing pulmonary valves in humans. We report here the long-term follow-up of the first documented transcatheter pulmonary valve implanted in a client-owned dog. A one-year-old Beagle dog with severe congenital type A valvular pulmonic stenosis first underwent percutaneous balloon pulmonary valvuloplasty, leading two years later to severe pulmonary regurgitation. A TPVI using a Melody™ bioprosthetic valve was then successfully performed, with normalization of the right heart cavities. Repeated two- and three-dimensional transthoracic echocardiographic examinations combined with Doppler modes confirmed the appropriate position and function of the valve for four years. Mitral myxomatous valvular degeneration led to refractory left-sided congestive heart failure, and the dog was humanely euthanized. After postmortem examination, X-ray imaging and histopathological evaluation of the stent and the valve were performed. Ex-vivo imaging of the implanted valve using a Faxitron® Path radiography system and microscopic evaluation of the implanted stent and bioprosthetic leaflets did not show any relevant leaflet or stent alterations. This case provides a proof of concept in interventional veterinary cardiology, showing that TPVI can be performed in dogs with subsequent long-term maintaining normal pulmonary valve function.

Specific Follicular Helper T Cell Signature in Takayasu Arteritis.

OBJECTIVE: Our aim was to compare transcriptome and phenotype profiles of CD4+ T cells and CD19+ B cells in patients with Takayasu arteritis (TAK), patients with giant cell arteritis (GCA), and healthy donors. METHODS: Gene expression analyses, flow cytometry immunophenotyping, T cell receptor (TCR) gene sequencing, and functional assessments of cells from peripheral blood and arterial lesions from TAK patients, GCA patients, and healthy donors were performed. RESULTS: Among the most significantly dysregulated genes in CD4+ T cells of TAK patients compared to GCA patients (n = 720 genes) and in CD4+ T cells of TAK patients compared to healthy donors (n = 1,447 genes), we identified a follicular helper T (Tfh) cell signature, which included CXCR5, CCR6, and CCL20 genes, that was transcriptionally up-regulated in TAK patients. Phenotypically, there was an increase in CD4+CXCR5+CCR6+CXCR3- Tfh17 cells in TAK patients that was associated with a significant enrichment of CD19+ B cell activation. Functionally, Tfh cells helped B cells to proliferate, differentiate into memory cells, and secrete IgG antibodies. Maturation of B cells was inhibited by JAK inhibitors. Locally, in areas of arterial inflammation, we found a higher proportion of tertiary lymphoid structures comprised CD4+, CXCR5+, programmed death 1+, and CD20+ cells in TAK patients compared to GCA patients. CD4+CXCR5+ T cells in the aortas of TAK patients had an oligoclonal α/ß TCR repertoire. CONCLUSION: We established the presence of a specific Tfh cell signature in both circulating and aorta-infiltrating CD4+ T cells from TAK patients. The cooperation of Tfh cells and B cells might be critical in the occurrence of vascular inflammation in patients with TAK.

Renin-producing Tumour in the Kidney of a Cat.

Clinical and post-mortem examination of an adult neutered male cat with immune-mediated haemolytic anaemia revealed suspected nodules of tumour tissue in the cortex of the right kidney. Cytology and histopathology indicated a malignant renal tumour of undetermined type. Immunohistochemistry confirmed renin production by a proportion of the tumour cells. The lesion may represent a renal adenocarcinoma producing renin or a tumour of juxtaglomerular cells ('reninoma').

Molecular Assessment of Microcirculation Injury in Formalin-Fixed Human Cardiac Allograft Biopsies With Antibody-Mediated Rejection.

Precise diagnosis of antibody-mediated rejection (AMR) in cardiac allograft endomyocardial biopsies (EMBs) remains challenging. This study assessed molecular diagnostics in human EMBs with AMR. A set of 34 endothelial, natural killer cell and inflammatory genes was quantified in 106 formalin-fixed, paraffin-embedded EMBs classified according to 2013 International Society for Heart and Lung Transplantation (ISHLT) criteria. The gene set expression was compared between ISHLT diagnoses and correlated with donor-specific antibody (DSA), endothelial injury by electron microscopy (EM) and prognosis. Findings were validated in an independent set of 57 EMBs. In the training set (n = 106), AMR cases (n = 70) showed higher gene set expression than acute cellular rejection (ACR; n = 21, p < 0.001) and controls (n = 15, p < 0.0001). Anti-HLA DSA positivity was associated with higher gene set expression (p = 0.01). Endothelial injury by electron microscopy strongly correlated with gene set expression, specifically in AMR cases (r = 0.62, p = 0.002). Receiver operating characteristic curve analysis for diagnosing AMR showed greater accuracy with gene set expression (area under the curve [AUC] = 79.88) than with DSA (AUC = 70.47) and C4d (AUC = 70.71). In AMR patients (n = 17) with sequential biopsies, increasing gene set expression was associated with inferior prognosis (p = 0.034). These findings were confirmed in the validation set. In conclusion, biopsy-based molecular assessment of antibody-mediated microcirculation injury has the potential to improve diagnosis of AMR in human cardiac transplants.

Transcatheter heart valve crimping and the protecting effects of a polyester cuff.

INTRODUCTION: Prior to deployment, the percutaneous heart valves must be crimped and loaded into sheaths of diameters that can be as low as 6mm for a 23mm diameter valve. However, as the valve leaflets are fragile, any damage caused during this crimping process may contribute to reducing its long-term durability in vivo. MATERIAL AND METHOD: Bovine pericardium percutaneous valves were manufactured as follows. The leaflets were sutured on a nitinol frame. A polyester cuff fabric served as a buffer between the pericardium and the stent. Two valves were crimped and one valve was used as control. The valves were examined in gross observation and micro-CT scan and then the leaflets were processed for histology and analyzed in scanning electron microscopy, light microscopy and transmission electron microscopy. RESULT: Crimping of the valves resulted in the increase thickness of the leaflets and there was no evidence of additional delamination. The heavy prints of the stents were irregularly distributed on the outflow surface in the crimped devices and were shallow and did not penetrate throughout the thickness of the leaflets. However, the wavy microscopy of collagen fiber bundles was well preserved. They were found to remain individualized without any agglutination as shown by the regular banding appearance. CONCLUSION: Crimping of self-deployable valves per se caused only minor damages to the leaflets. However, the procedure could be refined in order to minimize areas of high pressure and swelling of the tissue that can be accompanied with flow surface disruption and increase of the hydraulic conductance. The incorporation of a polyester buffer serves to prevent the deleterious effects that may be caused if the pericardium tissue were in direct contact with the nitinol stent.

Late Failing Heart Allografts: Pathology of Cardiac Allograft Vasculopathy and Association With Antibody-Mediated Rejection.

In heart transplantation, there is a lack of robust evidence of the specific causes of late allograft failure. We hypothesized that a substantial fraction of failing heart allografts may be associated with antibody-mediated injury and immune-mediated coronary arteriosclerosis. We included all patients undergoing a retransplantation for late terminal heart allograft failure in three referral centers. We performed an integrative strategy of heart allograft phenotyping by assessing the heart vascular tree including histopathology and immunohistochemistry together with circulating donor-specific antibodies. The main analysis included 40 explanted heart allografts patients and 402 endomyocardial biopsies performed before allograft loss. Overall, antibody-mediated rejection was observed in 19 (47.5%) failing heart allografts including 16 patients (40%) in whom unrecognized previous episodes of subclinical antibody-mediated rejection occurred 4.5 ± 3.5 years before allograft loss. Explanted allografts with evidence of antibody-mediated rejection demonstrated higher endothelitis and microvascular inflammation scores (0.89 ± 0.26 and 2.25 ± 0.28, respectively) compared with explanted allografts without antibody-mediated rejection (0.42 ± 0.11 and 0.36 ± 0.09, p = 0.046 and p < 0.0001, respectively). Antibody-mediated injury was observed in 62.1% of failing allografts with pure coronary arteriosclerosis and mixed (arteriosclerosis and atherosclerosis) pattern, while it was not observed in patients with pure coronary atherosclerosis (p = 0.0076). We demonstrate that antibody-mediated rejection is operating in a substantial fraction of failing heart allografts and is associated with severe coronary arteriosclerosis. Unrecognized subclinical antibody-mediated rejection episodes may be observed years before allograft failure.

Esophageal tissue engineering: Current status and perspectives.

Tissue engineering, which consists of the combination and in vivo implantation of elements required for tissue remodeling toward a specific organ phenotype, could be an alternative for classical techniques of esophageal replacement. The current hybrid approach entails creation of an esophageal substitute composed of an acellular matrix and autologous epithelial and muscle cells provides the most successful results. Current research is based on the use of mesenchymal stem cells, whose potential for differentiation and proangioogenic, immune-modulator and anti-inflammatory properties are important assets. In the near future, esophageal substitutes could be constructed from acellular "intelligent matrices" that contain the molecules necessary for tissue regeneration; this should allow circumvention of the implantation step and still obtain standardized in vivo biological responses. At present, tissue engineering applications to esophageal replacement are limited to enlargement plasties with absorbable, non-cellular matrices. Nevertheless, the application of existing clinical techniques for replacement of other organs by tissue engineering in combination with a multiplication of translational research protocols for esophageal replacement in large animals should soon pave the way for health agencies to authorize clinical trials.

Control of Immune Response to Allogeneic Embryonic Stem Cells by CD3 Antibody-Mediated Operational Tolerance Induction.

Implantation of embryonic stem cells (ESCs) and their differentiated derivatives into allogeneic hosts triggers an immune response that represents a hurdle to clinical application. We established in autoimmunity and in transplantation that CD3 antibody therapy induces a state of immune tolerance. Promising results have been obtained with CD3 antibodies in the clinic. In this study, we tested whether this strategy can prolong the survival of undifferentiated ESCs and their differentiated derivatives in histoincompatible hosts. Recipients of either mouse ESC-derived embryoid bodies (EBs) or cardiac progenitors received a single short tolerogenic regimen of CD3 antibody. In immunocompetent mice, allogeneic EBs and cardiac progenitors were rejected within 20-25 days. Recipients treated with CD3 antibody showed long-term survival of implanted cardiac progenitors or EBs. In due course, EBs became teratomas, the growth of which was self-limited. Regulatory CD4(+)FoxP3(+) T cells and signaling through the PD1/PDL1 pathway played key roles in the CD3 antibody therapeutic effect. Gene profiling emphasized the importance of TGF-ß and the inhibitory T cell coreceptor Tim3 to the observed effect. These results demonstrate that CD3 antibody administered alone promotes prolonged survival of allogeneic ESC derivatives and thus could prove useful for enhancing cell engraftment in the absence of chronic immunosuppression.

Inflammatory cell burden and phenotype in endomyocardial biopsies with antibody-mediated rejection (AMR): a multicenter pilot study from the AECVP.

This multicenter case-controlled pilot study evaluated myocardial inflammatory burden (IB) and phenotype in endomyocardial biopsies (EMBs) with and without pathologic antibody-mediated rejection (pAMR). Sixty-five EMBs from five European heart transplant centers were centrally reviewed as positive (grade 2, n = 28), suspicious (grade 1, n = 7) or negative (n = 30) for pAMR. Absolute counts of total, intravascular (IV) and extravascular (EV) immunophenotyped mononuclear cells were correlated with pAMR grade, capillary C4d deposition, donor specific antibody (DSA) status and acute cellular rejection (ACR). In pAMR+ biopsies, equivalent number of IV CD3+ T lymphocytes (23 ± 4/0.225 mm(2) ) and CD68+ macrophages (21 ± 4/0.225 mm(2) ) were seen. IB and cell phenotype correlated with pAMR grade, C4d positivity and DSA positivity (p < 0.0001). High numbers of IV T lymphocytes were associated with low grade ACR (p = 0.002). In late-occurring AMR EV plasma cells occurring in 34% of pAMR+ EMBs were associated with higher IB. The IB in AMR correlated with pAMR+, C4d positivity and DSA positivity. In pAMR+ equivalent numbers of IV T lymphocytes and macrophages were found. The presence of plasma cells was associated with a higher IB and occurrence of pAMR late after transplantation.

Expression and mutational status of treatment-relevant targets and key oncogenes in 123 malignant salivary gland tumours.

BACKGROUND: Malignant tumours of the salivary glands (MSGT) are rare and pleomorphic entities. Patients with advanced disease may benefit from targeted therapy; however, specific targets for optimising and personalising treatments are yet to be identified. DESIGN: Immunohistochemistry for C-KIT, EGFR, HER2, MUC1, phospho-mTOR, androgen/estrogens/progesterone receptors and Ki67 was carried out and evaluated in terms of progression-free and overall survival. High throughput molecular screening of key oncogenes was done in 107 patients using routine diagnostic methods and Sequenom technology. RESULTS: Several therapy leads were identified, including high levels of HER2 and androgen receptors in salivary duct carcinomas, C-KIT in myoepithelial carcinomas and EGFR in mucoepidermoid carcinomas. Recurrent mutations involving downstream elements of the EGFR pathway were found in HRAS, notably in tumours with a myoepithelial component, and in other key oncogenes (KRAS/NRAS/PI3KCA/BRAF/MAP2K). On the other hand, <1% of samples had EGFR or HER2 mutations. CONCLUSION: Several tumour subtypes overexpressed targets of directed therapies suggesting potential therapy leads. Genotyping results suggest activation downstream of EGFR in 18 of the 107 samples that could be associated with low efficacy of EGFR inhibitors. Other molecules, such as PI3K/MEK or mTOR inhibitors, may have anti-tumour activity in this subgroup. The high mutation rate in HRAS highlights a novel key oncogenic event in MSGT.

Therapeutic effect of fucoidan-stimulated endothelial colony-forming cells in peripheral ischemia.

BACKGROUND: Fucoidan, an antithrombotic polysaccharide, can induce endothelial colony-forming cells (ECFC) to adopt an angiogenic phenotype in vitro. OBJECTIVES: We evaluated the effect of fucoidan on vasculogenesis induced by ECFC in vivo. METHODS: We used a murine hindlimb ischemia model to probe the synergic role of fucoidan-treatment and ECFC infusion during tissue repair. RESULTS: We found that exposure of ECFC to fucoidan prior to their intravenous injection improved residual muscle blood flow and increased collateral vessel formation. Necrosis of ischemic tissue was significantly reduced on day 14, to 12.1% of the gastronecmius cross-sectional surface area compared with 40.1% in animals injected with untreated-ECFC. ECFC stimulation with fucoidan caused a rapid increase in cell adhesion to activated endothelium in flow conditions, and enhanced transendothelial extravasation. Fucoidan-stimulated ECFC were resistant to shear stresses of up to 21 dyn cm(-2). Direct binding assays showed strong interaction of fucoidan with displaceable binding sites on the ECFC membrane. Bolus intramuscular administration of fucoidan 1 day after surgery reduces rhabdomyolysis. Mice injected with fucoidan (15 mg kg(-1)) had significantly lower mean serum creatine phosphokinase (CPK) activity than control animals. This CPK reduction was correlated with muscle preservation against necrosis (P < 0.001). CONCLUSIONS: Fucoidan greatly increases ECFC-mediated angiogenesis in vivo. Its angiogenic effect would be due in part to its transportation to the ischemic site and its release after displacement by proteoglycans present in the extracellular matrix. The use of ECFC and fucoidan together, will be an efficient angiogenesis strategy to provide therapeutic neovascularization.

Significance of C4d Banff scores in early protocol biopsies of kidney transplant recipients with preformed donor-specific antibodies (DSA).

The significance of C4d-Banff scores in protocol biopsies of kidney transplant recipients with preformed donor-specific antibodies (DSA) has not been determined. We reviewed 157 protocol biopsies from 80 DSA+ patients obtained at 3 months and 1 year post-transplant. The C4d Banff scores (1,2,3) were associated with significant increments of microcirculation inflammation (MI) at both 3 months and 1 year post-transplant, worse transplant glomerulopathy and higher class II DSA-MFI (p < 0.01). Minimal-C4d had injury intermediate between negative and focal, while focal and diffuse-C4d had the same degree of microvascular injury. A total of 54% of patients had variation of C4d score between 3 months and 1 year post-transplant. Cumulative (3 month + 1 year) C4d scores correlated with long-term renal function worsening (p = 0.006). However, C4d staining was not a sensitive indicator of parenchymal disease, 55% of C4d-negative biopsies having evidence of concomitant MI. Multivariate analysis demonstrated that the presence of MI and class II DSA at 3 months were associated with a fourfold increased risk of progression to chronic antibody-mediated rejection independently of C4d (p < 0.05). In conclusion, the substantial fluctuation of C4d status in the first year post-transplant reflects a dynamic humoral process. However, C4d may not be a sufficiently sensitive indicator of activity, MI and DSA being more robust predictors of bad outcome.

[Detection of renin in chromophobe renal cell carcinomas]. / Detección de renina en carcinomas cromófobos de células renales.

AIM: To evaluate frequency of renin detection in chromophobe renal cell carcinoma, and if this expression was associated to systemic high blood pressure. MATERIAL AND METHODS: A descriptive retrospective study. All the cases with confirmed diagnosis of chromophobe carcinoma and resected between 1990 and 2004 were included in our study: 31 cases from 31 patients. Immunohistochemistry was carried out on sections from the paraffin-embedded tissue using a monoclonal antiserum. Patient blood pressure before and after neoplasm resection was registered from clinical histories. We compared frequencies of hypertension in cases with and without expression of renin (Fisher's text or chi(2) as appropriate) and evolution of HTA after tumour resection. RESULTS: We found that 10 of 31 tumors (32.3%) contained immunoreactivity for renin; this staining was diffuse in 6 cases and focal in the other 4. Systemic hypertension was detected in 6 of 10 (60.0%) patients with renin expression and in 6 of 21 (28.6%) patients without renin immunolabeling (p=0.13). After tumor resection none patient with renin expression and high blood pressure showed remission of the hypertension. CONCLUSION: Renin is frequently expressed in chromophobe renal cell carcinoma, but this renin appears clinically inactive. More studies will be necessary to know implications of this feature on clinical presentation, diagnosis or pathogenesis.

Expression of the familial cardiac valvular dystrophy gene, filamin-A, during heart morphogenesis.

Myxoid degeneration of the cardiac valves is a common feature in a heterogeneous group of disorders that includes Marfan syndrome and isolated valvular diseases. Mitral valve prolapse is the most common outcome of these and remains one of the most common indications for valvular surgery. While the etiology of the disease is unknown, recent genetic studies have demonstrated that an X-linked form of familial cardiac valvular dystrophy can be attributed to mutations in the Filamin-A gene. Since these inheritable mutations are present from conception, we hypothesize that filamin-A mutations present at the time of valve morphogenesis lead to dysfunction that progresses postnatally to clinically relevant disease. Therefore, by carefully evaluating genetic factors (such as filamin-A) that play a substantial role in MVP, we can elucidate relevant developmental pathways that contribute to its pathogenesis. In order to understand how developmental expression of a mutant protein can lead to valve disease, the spatio-temporal distribution of filamin-A during cardiac morphogenesis must first be characterized. Although previously thought of as a ubiquitously expressed gene, we demonstrate that filamin-A is robustly expressed in non-myocyte cells throughout cardiac morphogenesis including epicardial and endocardial cells, and mesenchymal cells derived by EMT from these two epithelia, as well as mesenchyme of neural crest origin. In postnatal hearts, expression of filamin-A is significantly decreased in the atrioventricular and outflow tract valve leaflets and their suspensory apparatus. Characterization of the temporal and spatial expression pattern of filamin-A during cardiac morphogenesis is a crucial first step in our understanding of how mutations in filamin-A result in clinically relevant valve disease.

[Case report and review of a voluminous right atrial myxoma revealed by heart failure]. / Volumineux myxome de l'oreillette droite révélé par une insuffisance cardiaque congestive.

Right atrial myxoma is a rare disease and its clinical presentation is not specific. The usual mode of revelation is heart failure. The most frequent complications are pulmonary embolism and atrioventricular valve obstruction by the tumor. A 49-year-old woman was admitted to intensive care unit for heart failure. The echocardiogram showed a voluminous right atrial myxoma, appending to the interatrial septum. Its surgical excision under extracorporeal circulation was successfully performed. Histology confirmed the final diagnosis of myxoma. No complication was observed at 6 months follow-up.

Outcome of subclinical antibody-mediated rejection in kidney transplant recipients with preformed donor-specific antibodies.

This study describes clinical relevance of subclinical antibody-mediated rejection (SAMR) in a cohort of 54 DSA-positive kidney transplant recipients receiving a deceased donor. In 3 months screening biopsies, 31.1% of patients met the criteria of SAMR. A total of 48.9% had an incomplete form of SAMR (g+/ptc+/C4d-negative) whereas 20% had no humoral lesions. Patients with SAMR at 3 months had at 1 year: a higher C4d score, ptc score, and arteriosclerosis score, higher rate of IFTA (100% vs. 33.3%, p < 0.01) and a higher rate of transplant glomerulopathy (43% vs. 0%, p = 0.02) compared to patients without 3-month SAMR. Patients with SAMR at 3 months exhibited at 1 year a higher class II MFImax-DSA and a lower mGFR compared to patients without SAMR (39.2 +/- 13.9 vs. 61.9 +/- 19.2 mL/min/1.73 m(2) respectively, p < 0.01). The group of patients with C4d-negative SAMR at 3 months developed more ptc and IFTA lesions, and lower GFR at 1 year in comparison to biopsies without humoral lesions. SAMR is a frequent entity in KTR with preexisting DSAs and promotes subsequent GFR impairment and development of chronic AMR. C4d-negative SAMR patients displayed an intermediate course between the no-SAMR group and the C4d+ SAMR group. Screening biopsies may be useful to recognize patients more likely to develop SAMR.

Combined heart and kidney transplantation in a patient with Fabry disease in the enzyme replacement therapy era.

Fabry disease (FD) is an X-linked genetic disease, resulting from the deficiency of alpha-galactosidase A, a lysosomal enzyme responsible for the cleavage of glycosphingolipids. In absence of enzyme replacement therapy (ERT), globotriaosylceramide (Gb3) accumulates in tissue, leading to progressive organ damage with severe renal, cardiac and central nervous system complications. We herein describe the first case of successful combined and simultaneous heart and kidney transplantation in a young male patient with FD complicated by end-stage renal disease and severe heart failure not responding to late-onset ERT. Combined heart and kidney transplantation can be recommended for Fabry patients with end-stage renal disease and overt hypertrophic cardiomyopathy, severe ischemic or valvular heart disease.

Soluble interleukin-2 receptor and metalloproteinase-9 expression in head and neck cancer: prognostic value and analysis of their relationships.

In a series of 84 head and neck patients, a statistically significant correlation was observed between high serum soluble interleukin (IL)-2 receptor alpha (sIL-2Ralpha) (P = 0.034) and metalloproteinase-9 (MMP-9) concentrations (P = 0.036) at diagnosis and a shorter survival of these patients. As MMP-9 has been shown to mediate cleavage of IL-2Ralpha (CD25) by preactivated T cells, we looked for a relationship between MMP-9 expression and soluble IL-2Ralpha serum concentrations in these cancer patients. We did not find any correlation between intratumoral expression of MMP-9 or serum MMP-9 concentrations and serum sIL-2Ralpha levels. These results led us to reassess the role of MMP-9 in the release of sIL-2Ralpha. Treatment of Kit225 leukaemic cells with recombinant MMP-9 slightly decreased membrane CD25 expression and was associated with an increased concentration of sIL-2Ralpha in the supernatants. However, using a selective inhibitor of MMP-9 we did not succeed in specifically inhibiting the release of sIL-2Ralpha by the Kit225 cell line or by phytohaemagglutinin (PHA)-activated peripheral blood mononuclear cells. In addition, in a preclinical mouse model, basal serum sIL-2Ralpha concentrations and sIL-2Ralpha production by activated cells were not altered in MMP-9-deficient mice compared to wild-type mice. Interestingly, a broad spectrum metalloproteinase inhibitor inhibited the release of sIL-2Ralpha by PHA-activated peripheral blood mononuclear cells, suggesting that in contrast with current views concerning the major role of MMP-9 in the cleavage of membrane IL-2Ralpha, other proteases are involved in the shedding of sIL-2Ralpha. MMP-9 and sIL-2Ralpha appear therefore as independent prognostic markers in head and neck cancers.

Magnetic resonance imaging of ruptured plaques in the rabbit with ultrasmall superparamagnetic particles of iron oxide.

BACKGROUND: Magnetic resonance imaging (MRI) enhanced with ultrasmall superparamagnetic particles of iron oxide (USPIO) has previously been evaluated in hyperlipidemic rabbits. The aim of this study was therefore to compare USPIO in ruptured and non-ruptured arteries in an atherosclerotic rabbit model. METHODS: Atherosclerotic-like lesions were induced by the combination of endothelial abrasion and high-cholesterol diet in iliac rabbit arteries (n = 16). Rupture of atherosclerotic lesions was realized by oversized balloon angioplasty in one iliac artery, whereas the contralateral artery was used as control. USPIO (ferumoxtran-10: 1 mmol Fe/kg) was administered immediately (n = 10) or 28 days (n = 6) after injury. MRI and histological analysis were performed 7 and 35 days after injury and in control arteries. RESULTS: In vivo MRI analysis showed extended susceptibility artifact with transluminal signal loss in all ruptured arteries 7 days after injury. In contrast, hyposignal was reduced 35 days following injury (i.e. after healing), and absent in non-ruptured arteries. Similarly, histological analysis of iron uptake was significantly increased 7 days after injury compared to healed-ruptured and control arteries. CONCLUSIONS: Accumulation ofUSPIO is significantly increased in ruptured as compared to non-ruptured arteries in the atherosclerotic rabbit model.

Skin involvement in scleroderma--where histological and clinical scores meet.

OBJECTIVES: A clinico-pathological study in diffuse systemic sclerosis (SSc) patients was performed to analyse whether the skin histological organization and the pro-fibrotic signals elicited by TGF-beta in fibroblasts vary according to the modified Rodnan skin score (mRSS). METHODS: Twenty-seven SSc patients underwent 45 skin biopsies with simultaneous measure of mRSS before or after treatment by immunosuppressive drugs, with or without autologous peripheral haematopoietic stem cell transplantation (HSCT). RESULTS: Double-blind optic microscopy analysis of the biopsies standard extracellular matrix stains allowed to define three histological subgroups: 6 with grade 1 weak fibrosis, 30 with grade 2 moderate fibrosis and 9 with grade 3 severe fibrosis. A significant (P < 0.0001) was identified between the grades of fibrosis and the mRSS. In skin fibroblast cultures, Smad3 phosphorylation levels, as well as mRNA steady-state levels of two transforming growth factor (TGF)-beta/Smad3 targets, COL1A2 and PAI-1, increased in parallel with the mRSS. When compared with pre-transplant values the degree of fibrosis observed after HSCT in the papillary and in the reticular dermis decreased in parallel with the fall in mRSS (n = 5 consecutive patients with repeated biopsies). CONCLUSIONS: The histological extent of skin fibrosis correlates closely with the mRSS. Both parameters appeared to regress after HSCT. The extent of TGF-beta signalling activation in SSc skin fibroblasts appears to parallel the severity of disease.