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Aim: Cardiac diseases remain a leading cause of cardiovascular disease (CVD) related hospitalisation and mortality. That is why research to improve our understanding of pathophysiological processes underlying cardiac diseases is of great importance. There is a strong need for healthy and diseased human cardiac tissue and related clinical data to accomplish this, since currently used animal and in vitro disease models do not fully grasp the pathophysiological processes observed in humans. This design paper describes the initiative of the Netherlands Heart Tissue Bank (NHTB) that aims to boost CVD-related research by providing an open-access biobank., Methods: The NHTB, founded in June 2020, is a non-profit biobank that collects and stores biomaterial (including but not limited to myocardial tissue and blood samples) and clinical data of individuals with and without previously known cardiac diseases. All individuals aged ≥ 18 years living in the Netherlands are eligible for inclusion as a potential future donor. The stored samples and clinical data will be available upon request for cardiovascular researchers., Conclusion: To improve the availability of cardiac tissue for cardiovascular research, the NHTB will include extensive (cardiac) biosamples, medical images, and clinical data of donors with and without a previously known cardiac disease. As such, the NHTB will function as a translational bridge to boost a wide range of cardiac disease-related fundamental and translational studies., (© 2022. The Author(s).)

Background: Infections with potentially cardiotropic viruses are associated with the development of atrial fibrillation (AF). However, whether direct viral infection of the atria is involved in the pathogenesis of AF is unclear. We have therefore analysed the presence of cardiotropic viral genomes in AF patients., Methods: Samples of left atrial tissue were obtained from 50 AF patients (paroxysmal, n = 20; long-standing persistent/permanent, n = 30) during cardiac surgery and from autopsied control patients (n = 14). Herein, the presence of PVB19, EBV, CMV, HHV‑6, adenovirus and enterovirus genomes was determined by polymerase chain reaction. The densities of CD45+ and CD3+ cells and fibrosis in the atria were quantified by (immuno)histochemistry., Results: Of the tested viruses only the PVB19 genome was detected in the atria of 10% of patients, paroxysmal AF (2 of 20) and long-standing persistent/permanent AF (3 of 30). Conversely, in 50% of controls (7 of 14) PVB19 genome was found. No significant association was found between PVB19 and CD45+ and CD3+ cells, or between the presence of PVB19 and fibrosis, in either control or AF patients., Conclusion: The presence of viral genomes is not increased in the atria of AF patients. These results do not support an important role for viral infection of the atria in the pathogenesis of AF., (© 2022. The Author(s).)

Objective: Inflammation of the atria is an important factor in the pathogenesis of atrial fibrillation (AF). Whether the extent of atrial inflammation relates with clinical risk factors of AF, however, is largely unknown. This we have studied comparing patients with paroxysmal and long-standing persistent/permanent AF., Methods: Left atrial tissue was obtained from 50 AF patients (paroxysmal = 20, long-standing persistent/permanent = 30) that underwent a left atrial ablation procedure either or not in combination with coronary artery bypass grafting and/or valve surgery. Herein, the numbers of CD45+ and CD3+ inflammatory cells were quantified and correlated with the AF risk factors age, gender, diabetes, and blood CRP levels., Results: The numbers of CD45+ and CD3+ cells were significantly higher in the adipose tissue of the atria compared with the myocardium in all AF patients but did not differ between AF subtypes. The numbers of CD45+ and CD3+ cells did not relate significantly to gender or diabetes in any of the AF subtypes. However, the inflammatory infiltrates as well as CK-MB and CRP blood levels increased significantly with increasing age in long-standing persistent/permanent AF and a moderate positive correlation was found between the extent of atrial inflammation and the CRP blood levels in both AF subtypes., Conclusion: The extent of left atrial inflammation in AF patients was not related to the AF risk factors, diabetes and gender, but was associated with increasing age in patients with long-standing persistent/permanent AF. This may be indicative for a role of inflammation in the progression to long-standing persistent/permanent AF with increasing age.

The incidence of heart valve hemangioma is very low and is mostly observed in the mitral and tricuspid valve. In 2006, two cases of aortic valve hemangioma were reported for the first time, including one with calcifying aortic valve stenosis. We now present a case of aortic valve hemangioma in a patient suffering from aortic valve insufficiency combined with atherosclerotic thickening.

Background: Cardiopulmonary bypass during cardiac surgery leads to impaired microcirculatory perfusion. We hypothesized that vascular leakage is an important contributor to microcirculatory dysfunction. Imatinib, a tyrosine kinase inhibitor, has been shown to reduce vascular leakage in septic mice. We investigated whether prevention of vascular leakage using imatinib preserves microcirculatory perfusion and reduces organ injury markers in a rat model of cardiopulmonary bypass., Methods: Male Wistar rats underwent cardiopulmonary bypass after treatment with imatinib or vehicle (n=8 per group). Cremaster muscle microcirculatory perfusion and quadriceps microvascular oxygen saturation were measured using intravital microscopy and reflectance spectroscopy. Evans Blue extravasation was determined in separate experiments. Organ injury markers were determined in plasma, intestine, kidney, and lungs., Results: The onset of cardiopulmonary bypass decreased the number of perfused microvessels by 40% in the control group [9.4 (8.6-10.6) to 5.7 (4.8-6.2) per microscope field; P<0.001 vs baseline], whereas this reduction was not seen in the imatinib group. In the control group, the number of perfused capillaries remained low throughout the experiment, whilst perfusion remained normal after imatinib administration. Microvascular oxygen saturation was less impaired after imatinib treatment compared with controls. Imatinib reduced vascular leakage and decreased fluid resuscitation compared with control [3 (3-6) vs 12 ml (7-16); P=0.024]. Plasma neutrophil-gelatinase-associated-lipocalin concentrations were reduced by imatinib., Conclusions: Prevention of endothelial barrier dysfunction using imatinib preserved microcirculatory perfusion and oxygenation during and after cardiopulmonary bypass. Moreover, imatinib-induced protection of endothelial barrier integrity reduced fluid-resuscitation requirements and attenuated renal and pulmonary injury markers., (Copyright © 2017 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Objective: Very little is known about histological aspects of paediatric scars and the possible role of the immune system during their formation. In this study, the histology thoracic scars caused by the placement of an implantable central venous access device in children who underwent treatment for cancer was assessed., Method: The amount and type of collagen, the collagen orientation, the type of elastic fibres, the vascularsation, and the count of neutrophils, macrophages, and lymphocytes were analysed. The severity of scarring was assessed using the Vancouver scar scale (VSS). To evaluate the role of the immune system on scar severity and histology, the scars of children suffering from acute lymphoblastic leukaemia (ALL) were compared with the scars of children suffering from other types of childhood cancer., Results: Our results showed an extremely random orientation of the collagen fibres of the paediatric scars with a mean collagen orientation index of 0.22 (standard deviation (SD) 0.10, zero indicating a perfectly random orientation and a perfectly parallel orientation). A lower collagen orientation index was seen in scars with a lower VSS score (VSS score <3: 0.19 versus VSS score ≥3 0.29, p=0.037). A higher total VSS score, resembling a worse scar, was assessed to the scars in the non-ALL group compared with the children with ALL (mean ALL: 0.91 (0-3) versus mean non-ALL: 2.50 (0-6), p=0.037)., Conclusion: To our knowledge, this is the first study investigating a wide array of histological aspects in paediatric scars. Compared with adult scars, an extremely random collagen orientation was found (0.22 in children versus 0.41 and 0.46 adult normotrophic and hypertrophic scars, respectively). A lower collagen orientation index was found in scars with a lower VSS score. In addition, less severe scarring was measured in children suffering from ALL compared with children suffering from other types of childhood cancer. This suggests that the immune system could play a role in the development of aberrant scarring and should be a target for future research.

Autopsy after transcatheter aortic valve implantation (TAVI) is a new field of interest in cardiovascular pathology. To identify the cause of death, it is important to be familiar with specific findings related to the time interval between the procedure and death. We aimed to provide an overview of the autopsy findings in patients with TAVI in their medical history divided by the timing of death with specific interest in the added value of autopsy over a solely clinically determined cause of death. In 8 European centres, 72 cases with autopsy reports were available. Autopsies were divided according to the time interval of death and reports were analysed. In 32 patients who died ≤72 h postprocedure, mortality resulted from cardiogenic or haemorrhagic shock in 62.5 and 34.4%, respectively. In 31 patients with mortality >72 h to ≤30 days, cardiogenic shock was the cause of death in 51.6% followed by sepsis (22.6%) and respiratory failure (9.7%). Of the nine patients with death >30 days, 88.9% died of sepsis, caused by infective endocarditis in half of them. At total of 12 patients revealed cerebrovascular complications. Autopsy revealed unexpected findings in 61.1% and resulted in a partly or completely different cause of death as was clinically determined. Autopsy on patients who underwent TAVI reveals specific patterns of cardiovascular pathology that clearly relate to the time interval between TAVI and death and significantly adds to the clinical diagnosis. Our data support the role of autopsy including investigation of the cerebrum in the quickly evolving era of cardiac device technology.

Successful stem cell therapy after acute myocardial infarction (AMI) is hindered by lack of engraftment of sufficient stem cells at the site of injury. We designed a novel technique to overcome this problem by assembling stem cell-microbubble complexes, named 'StemBells'. StemBells were assembled through binding of dual-targeted microbubbles (~3μm) to adipose-derived stem cells (ASCs) via a CD90 antibody. StemBells were targeted to the infarct area via an ICAM-1 antibody on the microbubbles. StemBells were characterized microscopically and by flow cytometry. The effect of ultrasound on directing StemBells towards the vessel wall was demonstrated in an in vitro flow model. In a rat AMI-reperfusion model, StemBells or ASCs were injected one week post-infarction. A pilot study demonstrated feasibility of intravenous StemBell injection, resulting in localization in ICAM-1-positive infarct area three hours post-injection. In a functional study five weeks after injection of StemBells cardiac function was significantly improved compared with controls, as monitored by 2D-echocardiography. This functional improvement neither coincided with a reduction in infarct size as determined by histochemical analysis, nor with a change in anti- and pro-inflammatory macrophages. In conclusion, the StemBell technique is a novel and feasible method, able to improve cardiac function post-AMI in rats., (Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.)

In most pre-clinical animal studies investigating stem cell therapy in acute myocardial infarction (AMI), the administered stem cells are isolated from healthy donors. In clinical practice, however, patients who suffer from AMI will receive autologous cells, for example using adipose-derived stem cells (ASC). During AMI, inflammation is induced and we hypothesized that this might affect characteristics of ASC. To investigate this, ASC were isolated from rat adipose tissue 1 day (1D group, n = 5) or 7 days (7D group, n = 6) post-AMI, and were compared with ASC from healthy control rats (Control group, n = 6) and sham-operated rats (Sham 1D group, n = 5). We found that significantly fewer ASC were present 1 day post-AMI in the stromal vascular fraction (SVF), determined by a colony-forming-unit assay (p < 0.001 vs. Control and 7D). These data were confirmed by flow cytometry, showing fewer CD90-positive cells in SVF of the 1D group. When cultured, no differences were found in proliferation rate and cell size between the groups in the first three passages. Also, no difference in the differentiation capacity of ASC was found. In conclusion, it was shown that significantly fewer stem cells were present in the SVF 1 day post-AMI; however, the stem cells that were present showed no functional differences.

Adipose tissue-derived stromal cells (ASC) form a rich source of autologous cells for use in regenerative medicine. In vitro induction of an endothelial phenotype may improve performance of ASCs in cardiovascular repair. Here, we report on an in vitro strategy using direct reprogramming of ASCs by means of ectopic expression of the endothelial-specific transcription factor SRY (sex determining region Y)-box18 (SOX18). SOX18 induces ASCs to express a set of genes involved in vascular patterning: MMP7, KDR, EFNB2, SEMA3G and CXCR4. Accordingly, SOX18 transduced ASCs reorganize under conditions of shear stress, display VEGF-induced chemotaxis and form tubular structures in 3D matrices in an MMP7-dependent manner. These in vitro findings provide insight into molecular and cellular processes downstream of SOX18 and show that reprogramming using SOX18 is sufficient to induce several endothelial-like features in ASCs., (Copyright © 2014. Published by Elsevier B.V.)

Objectives: Irreversible electroporation (IRE) is a new ablation technique that relies on high-voltage electrical pulses. This clinical study evaluates the pathological response of colorectal liver metastases (CRLM) treated with IRE and the clinical safety and feasibility., Methods: Ten patients with resectable CRLM were included. During laparotomy, the metastases were treated with IRE and resected 60 min later. Safety and feasibility were assessed based on adverse events, laboratory values, technical success and intra-operative ultrasound findings. Tissue response was assessed using triphenyl tetrazolium chloride (TTC) vitality staining and (immuno)histochemical stainings (HE, complement-3d and caspase-3)., Results: Ten lesions with a mean diameter of 2.4 cm were successfully electroporated and resected, on average, 84 min later (range 51-153 min). One minor transient cardiac arrhythmia occurred during IRE. Ultrasound showed a sharply demarcated hypoechoic ablation zone around the tumour. TTC showed avitality of all lesions, covering the complete tumour in 8/10 lesions. Although immunohistochemistry proved heterogeneous and difficult to interpret within the tumours, it confirmed irreversible cell damage in the tumour-free margin of all specimens., Conclusions: This ablate-and-resect study demonstrated avitality caused by IRE of CRLM in humans. Further characterisation of tissue- and tumour-specific electrical properties is warranted to improve ablation protocols for maximised tissue ablation., Key Points: • Irreversible electroporation induces cell death in colorectal liver metastases within 1 h. • The ablation zone shows a sharp demarcation between avital and vital tissue. • Apoptosis is involved in cell death of colorectal liver metastases after IRE. • Effects of IRE can be monitored real-time using intraoperative ultrasound. • Local electrical heterogeneities of tumour tissue may require tumour-specific ablation protocols.

The majority of patients survive an acute myocardial infarction (AMI). Their outcome is negatively influenced by post-AMI events, such as loss of viable cardiomyocytes due to a post-AMI inflammatory response, eventually resulting in heart failure and/or death. Recent pre-clinical animal studies indicate that mesenchymal stem cells derived from adipose tissue (ASC) are new promising candidates that may facilitate cardiovascular regeneration in the infarcted myocardium. In this review we have compared all animal studies in which ASC were used as a therapy post-AMI and have focused on aspects that might be important for future successful clinical application of ASC.

The Wistar rat is a commonly used strain for experimental animal models. Recently it was shown that results vary between studies using Wistar rats of different suppliers. Therefore we studied whether Wistar rats obtained from Harlan Laboratories (Ha, n=24) and Charles River (CR, n=22) had a different outcome in an acute myocardial infarction (AMI) model. AMI was induced in both Ha and CR Wistar rats by one operator. This resulted in a significantly higher survival rate for Ha (79.2±10.2%) compared with CR rats (54.2±10.2%, p<0.05). Furthermore, CR rats had lost significantly more weight after 7 days (-5.9±3.1%) compared with Ha rats (-0.8±1.7%; p<0.001), indicating a worse health status of the CR rats. Paradoxically, the induced infarct was smaller in CR rats (7.3±3.6% of the heart) compared with Ha rats (12.1±4.7%, p<0.05). This indicates that CR rats were less sensitive for the cardiomyocyte damage subsequent to AMI induction, but remarkably showed more clinical side effects indicating that Wistar rats from two suppliers had a different response within the same AMI model., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Ischemia-reperfusion (I/R) models have shown that C-reactive protein (CRP) and immunoglobulin M (IgM) are involved in complement activation. Binding of CRP and IgM to damaged cell membranes initiates complement activation and aggravates I/R injury in various organs. However, the time course of CRP- and IgM-mediated complement activation and the relation to hepatocellular injury and inflammation in liver I/R are unknown., Aim: To evaluate the time course of IgM- and CRP-related complement activation and the relation to hepatocellular injury and inflammation in a hepatic I/R rat model., Methods: Male Wistar rats were allocated to (1) five groups of animals exposed to 60 min of partial ischemia (70%) induced via clamping of the left segmental portal triad, followed by 0, 3, 6, 12 or 24 h of reperfusion (n = 6 in each group); (2) five groups of sham-operated animals with corresponding reperfusion times (n = 5), and (3) a control group sacrificed before ischemia (n = 5). Hepatocellular injury, inflammatory response, rat plasma CRP and IgM levels and immunohistochemical depositions of CRP, IgM and C3 were assessed for each group., Results: Histopathological injury scores of hematoxylin and eosin sections of ischemic liver lobes demonstrated increasing values throughout the reperfusion time with a peak at 12 h. Plasma aminotransferases (alanine aminotransferase and aspartate aminotransferase) significantly increased after 3 h of reperfusion, peaking at 6 h (3,100 ± 800 U/l; p < 0.05). Hepatic neutrophil influx significantly increased from 3 to 6 h of reperfusion (p < 0.05) and demonstrated the highest value at 12 h (1.1 ± 0.2 U/mg of protein). Plasma IL-6 levels in the ischemia groups showed peak values after 6 h of reperfusion, decreasing significantly thereafter (p < 0.05). Plasma CRP values reached highest levels after 3 h of reperfusion (mean 91 ± 5% of control pool), decreasing significantly thereafter. Rat IgM concentrations in plasma did not significantly change throughout the reperfusion time. Immunohistochemical depositions of IgM, CRP and C3 in ischemic lobes demonstrated a similar pattern in time, reaching maximum values at 12 h of reperfusion. The percentages of depositions of CRP and IgM were significantly correlated [r(S) = 0.569; p < 0.001; Spearman test]. The time course of C3 and CRP depositions throughout reperfusion and C3 and IgM staining were significantly similar [r(S) = 0.797 and r(S) = 0.656, respectively; p < 0.0001; ANOVA]., Conclusions: CRP and IgM depositions demonstrate a parallel time course throughout the reperfusion to hepatocellular damage, inflammatory response and activated complement deposition in this rat hepatic I/R model. Furthermore, the time course of CRP and IgM depositions was significantly similar to that of activated complement depositions., (© 2014 S. Karger AG, Basel.)

Inadequate healing following acute myocardial infarction (AMI) can lead to the development of heart failure. The ischemic myocardium triggers an inflammatory response that clears cell debris and initiates the onset of scar tissue formation. The duration and intensity of this inflammatory response have been linked to the cardiac functioning post-AMI. In order to diminish scar tissue formation and stimulate regeneration of cardiac tissue, mesenchymal stem cell (MSC) have been applied post-AMI and showed beneficial effects on cardiac function. However, other than the expected regeneration of cardiac tissue, modulation of the inflammatory response post-AMI, especially related to an effect on monocytes/macrophages, was recently found to be an important aspect of MSC therapy. In healing post-AMI, monocytes and macrophages are key players that can either stimulate or repress inflammation using different phenotypes. Increased levels of the proinflammatory phenotype have clinically been associated with poor cardiac functional outcome post-AMI. MSC have been suggested to switch the monocytes/macrophages phenotype into a more anti-inflammatory state and might therefore beneficially influence the duration and intensity of the inflammatory response and subsequent cardiac function post-AMI. To gain more insight into this effect of MSC, this review provides an overview of the most relevant studies regarding this modulatory effect of MSC on monocytes/macrophages including its mechanisms to improve cardiac functioning post-AMI.

Aims/hypothesis: Methylglyoxal (MGO) is a major precursor for advanced glycation end-products (AGEs), which are thought to play a role in vascular complications in diabetes. Known MGO-arginine-derived AGEs are 5-hydro-5-methylimidazolone (MG-H1), argpyrimidine and tetrahydropyrimidine (THP). We studied THP in relation to type 1 diabetes, endothelial dysfunction, low-grade inflammation, vascular complications and atherosclerosis., Methods: We raised and characterised a monoclonal antibody against MGO-derived THP. We measured plasma THP with a competitive ELISA in two cohort studies: study A (198 individuals with type 1 diabetes and 197 controls); study B (individuals with type 1 diabetes, 175 with normoalbuminuria and 198 with macroalbuminuria [>300 mg/24 h]). We measured plasma markers of endothelial dysfunction and low-grade inflammation, and evaluated the presence of THP and N (ε)-(carboxymethyl)lysine (CML) in atherosclerotic arteries., Results: THP was higher in individuals with type 1 diabetes than in those without (median [interquartile range] 115.5 U/μl [102.4-133.2] and 109.8 U/μl [91.8-122.3], respectively; p = 0.03). THP was associated with plasma soluble vascular cell adhesion molecule 1 in both study A (standardised β = 0.48 [95% CI 0.38, 0.58]; p < 0.001) and study B (standardised β = 0.31 [95% CI 0.23, 0.40]; p < 0.001), and with secreted phospholipase A2 (standardised β = 0.26 [95% CI 0.17, 0.36]; p < 0.001) in study B. We found no association of THP with micro- or macro-vascular complications. Both THP and CML were detected in atherosclerotic arteries., Conclusions/interpretation: Our results suggest that MGO-derived THP may reflect endothelial dysfunction among individuals with and without type 1 diabetes, and therefore may potentially play a role in the development of atherosclerosis and vascular disease.

Adipose tissue-derived stem cells (ASCs) are promising candidates for regenerative therapy, like after myocardial infarction. However, when transplanted into the infarcted heart, ASCs are jeopardized by the ischemic environment. Interestingly, it has been shown that multidrug resistance (MDR) proteins like the breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp) have a protective effect in haematopoietic stem cells. In ASC, however, only expression of BCRP was shown until now. In this study, we therefore analysed the expression and functional activity of BCRP and P-gp and their putative function in ischemia in ASC. BCRP and P-gp protein expression was studied over time (passages 2-6) using western blot analysis and immunohistochemical staining. MDR activity was analysed using protein-specific substrate extrusion assays. Ischemia was induced using metabolic inhibition. All analyses demonstrated protein expression and activity of BCRP in ASCs. In contrast, only minor expression of P-gp was found, without functional activity. BCRP expression was most prominent in early passage ASCs (p2) and decreased during culture. Finally, ischemia induced expression of BCRP. In addition, when BCRP was blocked, a significant increase in dead ASCs was found already after 1 h of ischemia. In conclusion, ASCs expressed BCRP, especially in early passages. In addition, we now show for the first time that BCRP protects ASCs against ischemia-induced cell death. These data therefore indicate that for transplantation of ASCs in an ischemic environment, like myocardial infarction, the optimal stem cell protective effect of BCRP theoretically will be achieved with early culture passages ASCs.

Adipose-derived stromal cells (ASC) are promising candidates for cell therapy, for example to treat myocardial infarction. Commonly, fetal bovine serum (FBS) is used in ASC culturing. However, FBS has several disadvantages. Its effects differ between batches and, when applied clinically, transmission of pathogens and antibody development against FBS are possible. In this study, we investigated whether FBS can be substituted by human platelet lysate (PL) in ASC culture, without affecting functional capacities particularly important for cardiac repair application of ASC. We found that PL-cultured ASC had a significant 3-fold increased proliferation rate and a significantly higher attachment to tissue culture plastic as well as to endothelial cells compared with FBS-cultured ASC. PL-cultured ASC remained a significant 25% smaller than FBS-cultured ASC. Both showed a comparable surface marker profile, with the exception of significantly higher levels of CD73, CD90, and CD166 on PL-cultured ASC. PL-cultured ASC showed a significantly higher migration rate compared with FBS-cultured ASC in a transwell assay. Finally, FBS- and PL-cultured ASC had a similar high capacity to differentiate towards cardiomyocytes. In conclusion, this study showed that culturing ASC is more favorable in PL-supplemented medium compared with FBS-supplemented medium.

Stem cell therapy is a promising tool to improve outcome after acute myocardial infarction (AMI), but needs to be optimized since results from clinical applications remain ambiguous. A potent source of stem cells is the stromal vascular fraction of adipose tissue (SVF), which contains high numbers of adipose derived stem cells (ASC). We hypothesized that: 1) intravenous injection can be used to apply stem cells to the heart. 2) Uncultured SVF cells are easier and safer when cultured ASCs. 3) Transplantation after the acute inflammation period of AMI is favorable over early injection. For this, AMI was induced in rats by 40min of coronary occlusion. One or seven days after AMI, rats were intravenously injected with vehicle, 5×10(6) uncultured rat SVF cells or 1×10(6) rat ASCs. Rats were analyzed 35 days after AMI. Intravenous delivery of both fresh SVF cells and cultured ASCs 7 days after AMI significantly reduced infarct size compared to vehicle. Similar numbers of stem cells were found in the heart, after treatment with fresh SVF cells and cultured ASCs. Importantly, no adverse effects were found after injection of SVF cells. Using cultured ASCs, however, 3 animals had shortness of breath, and one animal died during injection. In contrast to application at 7 days post AMI, injection of SVF cells 1 day post AMI resulted in a small but non-significant infarct reduction (p=0.35). Taken together, intravenous injection of uncultured SVF cells subsequent to the acute inflammation period, is a promising stem cell therapy for AMI., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: Recent studies indicate a role for complement in the pathogenesis of aortic valve disease. However, the role of naturally occurring anti-complement mediators in this context is unknown. In this study, we have analysed this in three different pathological conditions of the aortic valve: degeneration, atherosclerosis and bacterial endocarditis., Materials and Methods: Human aortic valves were obtained at autopsy (n = 30): 5 control valves, 10 aortic valves with atherosclerotic changes, 10 aortic valves with degenerative changes and 5 degenerative changed aortic valves with bacterial infection. These valves were analysed immunohistochemically for the presence of activated complement (C3d and C5b9) and the complement inhibitors C1-inh and clusterin. Areas of positivity were then quantified., Results: C3d, C5b9 and the complement inhibitors C1-inh and clusterin depositions were mainly found in the endothelium and extracellular matrix in aortic valves. All these mediators were already present in control valves, but the area of positivity increased significantly in response to the different diseases, with the highest increase in response to bacterial endocarditis. Interestingly, in all three aortic diseases, the depositions of complement were significantly more widespread than that of their inhibitors., Conclusions: Our study indicates that anti-complement mediators (C1-inh and clusterin) are deposited in diseased aortic valves together with activated complement, indicating an existing counter response against complement locally in the valve. However, deposition of activated complement is significantly more widespread than that of its inhibitors, which could explain ongoing inflammation in those diseased aortic valves.

Adipose-derived stem cells (ASCs) are promising candidates for therapy in myocardial infarction (MI). However, the frequency of human ASCs that differentiate towards cardiomyocytes is low. We hypothesized that adherence to extracellular matrix molecules that are upregulated after MI might increase human stem cell differentiation towards cardiomyocytes. We analysed putative ASC differentiation on fibronectin-coated, laminin-coated and uncoated culture plates. Expression of cardiac markers in cells was analysed 1, 3 and 5 weeks after stimulation with 5-aza-2-deoxycytidine. After 1 week, mRNA expression of myosin light chain-2alpha (MLC-2alpha), an early marker in cardiomyocyte development, was increased significantly in treated cells, independent of coating. At 5 weeks, however, mRNA expression of the late cardiomyocyte development marker SERCA2alpha was only significantly increased in 5-aza-2-deoxycytidine-treated cells cultured on laminin. Significantly higher numbers of cells were immunopositive for MLC-2alpha in cultures of treated cells grown on laminin-coated wells, when compared with cultures of treated cells grown on uncoated wells, both at 1 week and at 5 weeks. Furthermore, after 3 weeks, significantly more alpha-actinin- and desmin-positive cells were detected after treatment with 5-aza-2-deoxycytidine, but only in uncoated wells. After 5 weeks, however, the number of desmin-positive cells was only significantly increased after treatment of cells with 5-aza-2-deoxycytidine and culture on laminin (61% positive cells). Thus, we have found that a high percentage of human ASCs can be differentiated towards cardiomyocytes; this effect can be improved by laminin, especially during late differentiation.

Background: Several studies have suggested an association between Chlamydophila pneumoniae (Cp) infection and atherosclerosis. A recent study detected Cp DNA in the saphenous vein of 12% of all patients before bypass grafting and in 38% of failed grafts. We used a system in which human veins were perfused with autologous blood under arterial pressure., Materials and Methods: Veins were surplus segments of saphenous veins of coronary artery bypass grafting (CABG) patients. Vein grafts were perfused with the blood of the same patient after CABG procedures. Veins were analysed for Cp-specific membrane protein using immunohistochemical and PCR analysis. Veins were analysed before and after perfusion (up to 4 h). The number of Cp positive cells was then quantified in the vein layers., Results: Cp protein was detected within macrophages only. In non-perfused veins, Cp was present in the adventitia in 91% of all patients, in the circular (64%) and longitudinal (23%) layer of the media. No positivity was found in the intima. Perfusion subsequently resulted in a significant increase of Cp positive cells within the circular layer of the media that, however, differed strongly between different patients. Cp DNA was not detected by PCR in those specimens., Conclusion: Cp protein was present in 91% of veins, but the number of positive cells differed remarkably between patients. Perfusion of veins resulted in increased infiltration of Cp into the circular layer. These results may point to a putative discriminating role of Cp with respect to graft failure between different patients.

Objective: Non-enzymatic glycation of proteins and their end products (advanced glycation end products, AGE) have been implicated in the pathogenesis of diabetic complications. Our aim was to evaluate the association between diabetes mellitus (DM) and the accumulation of one of the most abundant AGEs, Nepsilon-(carboxymethyl)-lysine (CML), in cerebral vessels., Research Design and Methods: Brain tissue samples were obtained by autopsy from 20 DM patients and 13 age-matched controls. In addition, we investigated brain tissue samples of seven rats after induction of diabetes with streptozotocin (STZ) and six non-diabetic control rats. We used an immunohistochemical staining method to examine the CML immunoreactivity in the cerebral vessels., Results: Staining intensity of CML was significantly higher in cerebral vessels of diabetic patients than in non-diabetic subjects (median of the immunohistochemical intensity score/cm(2) in the diabetic group of 0.85 (interquartile range (IQR) 0.66-1.52) vs 0.63 in the control group (IQR 0.44-0.70); P=0.002). Furthermore, there was a similar significant difference in CML staining intensity of cerebral vessels between STZ diabetic rats and non-diabetic control rats (median of the immunohistochemical intensity score/cm(2) in the diabetic group of 1.08 (IQR 0.73-1.43) vs 0.23 in the control group (IQR 0.12-0.43); P=0.003)., Conclusions: Accumulation of CML-modified proteins is significantly greater in the cerebral vessels of the diabetic patients than their age-matched controls. This association has been confirmed in the insulin-deficient diabetic rat model. It may be possible that the excessive accumulation of AGE-modified proteins in the cerebral vasculature alters the local environment and microcirculation and thereby contributes to the development of cognitive impairments in diabetes. Therefore, additional study on the causal link between AGE accumulation and cognitive dysfunction and the potential benefits of AGE-blocking and/or breaking compounds is indicated.

Stem cell therapy is a promising treatment after myocardial infarction (MI). A major problem in stem cell therapy, however, is that only a small proportion of stem cells applied to the heart can survive and differentiate into cardiomyocytes. We hypothesized that fibronectin in the heart after MI might positively affect stem cell adhesion and proliferation at the site of injury. Therefore, we investigated the kinetics of attachment and proliferation of adipose-tissue-derived stem cells (ASC) on fibronectin and analysed the time frame and localization of fibronectin accumulation in the human heart after MI. ASCs were seeded onto fibronectin-coated and uncoated culture wells. The numbers of adhering ASC were quantified after various incubation periods (5-30 min) by using DNA quantification assays. The proliferation of ASC was quantified after culturing ASC for various periods (0-9 days) by using DNA assays. Fibronectin accumulation after MI was quantified by immunohistochemical staining of heart sections from 35 patients, after different infarction periods (0-14 days old). We found that ASC attachment and proliferation on fibronectin-coated culture wells was significantly higher than on uncoated wells. Fibronectin deposition was significantly increased from 12 h to 14 days post-infarction, both in the infarction area and in the border-zone, compared with the uninfarcted heart. Our results suggest that a positive effect of fibronectin on stem cells in the heart can only be achieved when stem cell therapy is applied at least 12 h after MI, when the accumulation of fibronectin occurs in the infarcted heart.

Background: Secretory type-II phospholipase A(2) (sPLA(2)-II) is a cardiovascular risk marker since higher levels of this acute phase protein imply an increased risk for coronary artery disease. Moreover, it is hypothesized that local activity of sPLA(2)-II in the atherosclerotic plaque facilitates an inflammatory response to induce plaque instability or rupture. We have studied the presence of sPLA(2)-II in culprit lesions in the coronary arteries of patients with acute myocardial infarction (AMI) or angina pectoris., Materials and Methods: We performed a histological examination of culprit lesions in 41 patients with stable (SAP) or unstable angina pectoris (UAP), or AMI using directed coronary atherectomy (DCA). Frozen slides were analysed immuno-histochemically for the presence of sPLA(2)-II, macrophages and smooth muscle cells. Immunopositive areas were calculated as a percentage of the total tissue area using image analysis software., Results: Intracellular sPLA(2)-II was found in atherosclerotic lesions in the macrophages of the intima as well as in vascular smooth muscle cells. Next to this, extracellular sPLA(2)-II depositions were also found. These depositions were significantly more extensive in patients with AMI, i.e. 26%(median)[6%(25th(percentile))-44%(75th(percentile))] of the intima area, than in patients with SAP 0%(median) (0%(25th)-10%(75th); P = 0.013) or UAP 0%(median) (0%(25th)-0%(75th); P = 0.04)., Conclusions: Extracellular sPLA(2)-II is more abundantly present in atherosclerotic culprit lesions that have led to myocardial infarction. This suggests a role for extracellular sPLA(2)-II in the development of complications of atherosclerotic lesions in coronary arteries.

Background: Pulmonary embolism (PE) is a significant cause of morbidity and mortality. In a recent study in patients with PE, an increased level of macrophages was found in the right ventricle., Objective: To evaluate the presence of inflammatory cells, myocytolysis and intracavitary thrombi in the left and right ventricle of patients who died because of PE as a putative new source of heart failure., Patients and Methods: 22 patients with PE were studied. For comparison, eight controls and 11 patients who died of chronic pulmonary hypertension (PHT) were used. Slides of the left and right ventricle were stained with antibodies, identifying neutrophilic granulocytes, lymphocytes and macrophages, which were subsequently quantified. Myocytolysis was visualised using complement staining. Thrombi were identified by conventional staining., Results: Compared with controls, in patients with PE a significant increase in extravascular localisation of all three inflammatory cells was found both in the right and left ventricle, coinciding with myocytolysis, indicative for myocarditis. No increase in inflammatory cells was found in patients with PHT. Endocardial cellular infiltration was also found, partly coinciding with the presence of ventricular thrombi., Conclusions: In patients with PE, endomyocarditis and intracavitary thrombi in the left and right ventricle were found. These abnormalities may be an additional new explanation for the observed cardiac enzyme release and functional abnormalities of the heart in these patients and may contribute to the morbidity and mortality of the disease.

The purpose of this study was to investigate the cardioprotective effect of the semisynthetic flavonoid 7-monohydroxyethylrutoside (monoHER) on doxorubicin (DOX)-induced cardiotoxicity in a phase II study in patients with metastatic cancer. Eight patients with metastatic cancer were treated with DOX preceded by a 10 min i.v. infusion of 1500 mg m(-2) monoHER. Five patients were examined by endomyocardial biopsy after reaching a cumulative dose of 300 mg m(-2). Histopathological changes in the cardiomyocytes (Billingham score) were compared with those described in literature for patients treated with DOX only. The mean biopsy score of the patients was higher (2.7) than the mean score (1.4) of historical data of patients who received similar cumulative doses of DOX. Although there is a considerable variability in few investigated patients, it was indicative that monoHER enhanced DOX-induced cardiotoxicity. However, the antitumour activity of DOX seemed better than expected: three of the four patients with metastatic soft-tissue sarcoma had a partial remission and the fourth patient stable disease. It is likely that the relatively high dose of monoHER is responsible for the lack of cardioprotection and for the high response rate in patients with soft-tissue sarcoma possibly by depleting the glutathione defense system in both heart and tumour.

Cardiac damage is the major limiting factor for the clinical use of doxorubicin (DOX). Preclinical studies indicate that inflammatory effects may be involved in DOX-induced cardiotoxicity. Nepsilon-(carboxymethyl) lysine (CML) is suggested to be generated subsequent to oxidative stress, including inflammation. Therefore, the aim of this study was to investigate whether CML increased in the heart after DOX and whether anti-inflammatory agents reduced this effect in addition to their possible protection on DOX-induced cardiotoxicity. These effects were compared with those of the potential cardioprotector 7-monohydroxyethylrutoside (monoHER).BALB/c mice were treated with saline, DOX alone or DOX preceded by ketoprofen (KP), dexamethasone (DEX) or monoHER. Cardiac damage was evaluated according to Billingham. Nepsilon-(carboxymethyl) lysine was quantified immunohistochemically. Compared to saline, a 21.6-fold increase of damaged cardiomyocytes was observed in mice treated with DOX (P<0.001). Addition of KP, DEX or monoHER before DOX significantly reduced the mean ratio of abnormal cardiomyocytes in comparison to mice treated with DOX alone (P

Objective: Advanced glycation end products (AGEs), such as N(epsilon)-(carboxymethyl)lysine (CML), are implicated in vascular disease. We previously reported increased CML accumulation in small intramyocardial blood vessels in diabetes patients. Diabetes patients have an increased risk for acute myocardial infarction (AMI). Here, we examined a putative relationship between CML and AMI., Methods and Results: Heart tissue was stained for CML, myeloperoxidase, and E-selectin in AMI patients (n=26), myocarditis patients (n=17), and control patients (n=15). In AMI patients, CML depositions were 3-fold increased compared with controls in the small intramyocardial blood vessels and predominantly colocalized with activated endothelium (E-selectin-positive) both in infarction and noninfarction areas. A trend of increased CML positivity of the intima of epicardial coronary arteries did not reach significance in AMI patients. In the rat heart AMI model, CML depositions were undetectable after 24 hours of reperfusion, but became clearly visible after 5 days of reperfusion. In line with an inflammatory contribution, human myocarditis was also accompanied by accumulation of CML on the endothelium of intramyocardial blood vessels., Conclusions: CML, present predominantly on activated endothelium in small intramyocardial blood vessels in patients with AMI, might reflect an increased risk for AMI rather than being a result of AMI.

In previous work we have demonstrated increased expression of NOX2 in cardiomyocytes of infarcted human hearts. In the present manuscript we investigated the functional role of NOX2 in ischemically challenged H9c2 cells, a rat cardiomyoblast cell line, and adult rat cardiomyocytes. Expression of NOX2 in H9c2 cells was confirmed by RT-PCR. In Western-blot experiments, increased NOX2 expression was detected during ischemia, which was inhibited by transcription and translation inhibitors. Surprisingly, under ischemia, in addition to an increased cytosolic expression, NOX2 was localized mainly in the nucleus of apoptotic cardiomyocytes, where it colocalized with nitrotyrosine residues and activated caspase 3. Inhibition of reactive-oxygen-species generation with the flavoenzyme inhibitor diphenylene iodonium (DPI) and the NADPH-oxidase inhibitor apocynin led to a significantly decreased induction of apoptosis as assessed by quantification of caspase-3 activity and by TUNEL analysis. These results demonstrate that NOX2 is expressed in the nucleus of cardiomyocytes during apoptosis and that it likely participates in proapoptotic signaling. To the best of our knowledge, this is the first demonstration of nuclear NOX2 expression and its involvement in cardiomyocyte apoptosis.

Background: C reactive protein (CRP), an important serum marker of atherosclerotic vascular disease, has recently been reported to be active inside human atherosclerotic plaques., Aims: To investigate the simultaneous presence of macrophages, CRP, membrane attack complex C5b-9 (MAC), and oxidised low density lipoprotein (oxLDL) in atherectomy specimens from patients with different coronary syndromes., Methods: In total, 54 patients with stable angina (SA; n = 21), unstable angina (UA; n = 15), and myocardial infarction (MI; n = 18) underwent directional coronary atherectomy for coronary lesions. Cryostat sections of atherosclerotic plaques were immunohistochemically stained with monoclonal antibodies: anti-CD68 (macrophages), anti-5G4 (CRP), aE11 (MAC), and 12E7 (oxLDL). Immunopositive areas were evaluated in relation to fibrous and neointima tissues, atheroma, and media. Quantitative analysis was performed using image cytometry with systematic random sampling (percentage immunopositive/total tissue area)., Results: Macrophages, CRP, MAC, and oxLDL were simultaneously present in a higher proportion of fibrous tissue and atheroma of atherectomy specimens from patients with UA and MI compared with SA (p<0.05). Quantitative analysis showed significantly higher mean percentages of macrophages in plaques from patients with MI (44%) than UA (30%; p<0.01) and SA (20%; p<0.001). Significantly higher mean percentages of CRP were also seen in MI (25%) and UA (25%) compared with SA (12%; p<0.05)., Conclusions: The presence of CRP, complement, and oxLDL in a high proportion of plaque tissue from patients with unstable coronary artery disease implies that these surrogate markers have important proinflammatory effects inside atherosclerotic plaques. This may increase vulnerability to plaque rupture and thrombosis, with subsequent clinical sequelae.

We examined the relationship between clusterin and activated complement in human heart infarction and evaluated the effect of this protein on ischemic rat neonatal cardiomyoblasts (H9c2) and isolated adult ventricular rat cardiomyocytes as in vitro models of acute myocardial infarction. Clusterin protects cells by inhibiting complement and colocalizes with complement on jeopardized human cardiomyocytes after infarction. The distribution of clusterin and complement factor C3d was evaluated in the infarcted human heart. We also analyzed the protein expression of clusterin in ischemic H9c2 cells. The binding of endogenous and purified human clusterin on H9c2 cells was analyzed by flow cytometry. Furthermore, the effect of clusterin on the viability of ischemically challenged H9c2 cells and isolated adult ventricular rat cardiomyocytes was analyzed. In human myocardial infarcts, clusterin was found on scattered, morphologically viable cardiomyocytes within the infarcted area that were negative for complement. In H9c2 cells, clusterin was rapidly expressed after ischemia. Its expression was reduced after reperfusion. Clusterin bound to single annexin V-positive or annexin V and propidium iodide-positive H9c2 cells. Clusterin inhibited ischemia-induced death in H9c2 cells as well as in isolated adult ventricular rat cardiomyocytes in the absence of complement. We conclude that ischemia induces the upregulation of clusterin in ischemically challenged, but viable, cardiomyocytes. Our data suggest that clusterin protects cardiomyocytes against ischemic cell death via a complement-independent pathway.

Aims: Reperfusion of ischaemic myocardium after acute myocardial infarction (AMI) can induce ischaemia/reperfusion (I/R) injury, as a result of local activation of the complement system. C reactive protein (CRP) is involved in this activation. This study analysed the potential role of IgM in complement activation in the infarcted human myocardium., Methods: Immunochemical analysis was carried out on heart specimens from 59 patients who died from AMI. Serial slides of frozen tissue from the infarction site were stained for IgM, complement factors C3d and C5b-9 (membrane attack complex), and CRP., Results: IgM deposits were found on the plasma membrane, cross striations, and in the cytoplasm of jeopardised cardiomyocytes in infarcts of one to five days duration. IgM depositions were remarkably similar to those of CRP and both complement factors. The relative staining intensities of IgM and CRP varied greatly among patients., Conclusions: Similar to CRP, IgM targets complement locally to jeopardised cardiomyocytes in the human heart after AMI. Localisation patterns and relative staining intensities suggest that IgM and CRP recognise similar epitopes in the ischaemic heart, but that the relative contribution of each protein to complement activation in the ischaemic myocardium differs among patients.

The cardiovascular system is a common target of amyloidosis. This review presents the current clinical and diagnostic approach to amyloidosis, with the emphasis on cardiovascular involvement. It summarises recent nomenclature, classification, and pathogenesis of amyloidosis. In addition, non-invasive possibilities are discussed, together with endomyocardial biopsies in the diagnosis of cardiac amyloidosis. Finally, recent advances in treatment and prognostic implications are presented.

Background: Impaired perfusion of the heart induces a local inflammatory response, which involves deposition of C-reactive protein and complement activation products C3d and C5b-9. We investigated whether reperfusion or reinfarction enhances these phenomena in humans., Materials and Methods: Depositions of C-reactive protein and complement were quantified in tissue samples of infarcted myocardium from 76 patients who had died after acute myocardial infarction. The extent of depositions in patients treated with reperfusion or suffering from reinfarction was compared with that in patients who had no reperfusion or reinfarction., Results: Patients with reinfarction had significantly more extensive depositions of C-reactive protein and complement (C3d and C5b-9) in the infarcted myocardium than patients without reinfarction. Similarly, patients who received reperfusion therapy had more extensive depositions also than those who had not received this therapy., Conclusions: Both reinfarction and reperfusion therapy significantly increase the extent of C-reactive protein and complement depositions in human myocardial infarcts.

Certain strains of Escherichia coli have been shown to cause gas accumulation in--for example, emphysematous pyelonephritis. This paper describes a patient with intramyocardial air collections resulting from an intramyocardial infection with gas forming E coli.

Inflammation plays an important role in the initiation, development, progression and complications of atherosclerotic vascular disease. Our present knowledge of the elementary role of inflammation for the onset of plaque rupture in atherosclerotic coronary lesions primarily stems from autopsy studies. However, the introduction of directional coronary atherectomy catheters has provided a unique opportunity to directly investigate the role of inflammation in coronary syndromes. In this report we describe the role of coronary plaque inflammation, as determined by immunohistochemistry, on the presentation of coronary syndromes and on the clinical outcome following percutaneous interventions.

Type II secretory phospholipase A2 (sPLA2) is a cardiovascular risk factor. We recently found depositions of sPLA2 in the necrotic center of infarcted human myocardium and normally appearing cardiomyocytes adjacent to the border zone. The consequences of binding of sPLA2 to ischemic cardiomyocytes are not known. To explore a potential effect of sPLA2 on ischemic cardiomyocytes at a cellular level we used an in vitro model. The cardiomyocyte cell line H9c2 or adult cardiomyocytes were isolated from rabbits that were incubated with sPLA2 in the presence of metabolic inhibitors to mimic ischemia-reperfusion conditions. Cell viability was established with the use of annexin V and propidium iodide or 7-aminoactinomycin D. Metabolic inhibition induced an increase of the number of flip-flopped cells, including a population that did not stain with propidium iodide and that was caspase-3 negative. sPLA2 bound to the flip-flopped cells, including those negative for caspase-3. sPLA2 binding induced cell death in these latter cells. In addition, sPLA2 potentiated the binding of C-reactive protein (CRP) to these cells. We conclude that by binding to flip-flopped cardiomyocytes, including those that are caspase-3 negative and presumably reversibly injured, sPLA2 may induce cell death and tag these cells with CRP.

Background: The amelioration of the adaptation process (arterialisation) of the vein graft wall to the arterial circulation in coronary artery bypass surgery by using extravascular support is clearly established in animal models and in in vitro and ex vivo set-ups. This support consists of some form of external graft-supporting modality like a prosthetic graft of stent. The clinical application of perivenous support, however, is hampered due to the fact that no easy applicable external support is available. Considering that application in the form of a spray is the most convenient modality, we evaluated whether polyethylene glycol is capable of providing adequate perivenous support. Polyethylene glycol is a synthetic, biodegradable product, used in cardiac surgery as a sealant, and is commercially available in the form of a spray., Methods: Segments of human saphenous vein graft obtained during coronary artery bypass graft (CABG) procedures were placed in an ex vivo model, a side loop of the extracorporeal perfusion circuit, and perfused with autologous blood, making the circumstances identical to the implanted saphenous vein grafts concerning pressure, temperature, level of complement and leukocyte activation and blood pressure. Alternately around every other study vein graft segment polyethylene glycol was applied. Unsupported grafts served as control. After 1 min of solidification, perfusion was started with a pressure of about 60 mmHg (nonpulsatile flow). Perfusion was maintained for 60 min, after which the grafts were collected for light microscopy and electron microscopy., Results: Light microscopy and electron microscopy showed remarkable attenuation of endothelial cell loss and less injury of smooth muscle cells of the circular and longitudinal layer of the media in the supported group compared to the nonsupported vein graft segments., Conclusion: Polyethylene glycol is able to provide adequate external vein graft support, preventing overdistension, in an ex vivo model. This provides a basis for clinical application. Further investigation is warranted to evaluate long-term effects.

Background/aims: Recent studies indicate the presence of reactive oxygen species (ROS) producing homologues of the enzymatic subunit (Nox2) of phagocytic NADPH oxidase in non-phagocytic cells. Interestingly, in these cells, ROS produced by the Nox2 homologue(s) was shown to play a role in various regulatory processes, including cell death, proliferation, and aging. The purpose of this study was to investigate whether human cardiomyocytes express Nox2., Methods: The expression of Nox2 was studied in human cardiomyocytes using western blot and immunohistochemical analysis. To analyse the putative expression of Nox2 in human heart disease, cardiac samples from patients who had died subsequent to acute myocardial infarction (AMI) were studied., Results: Both in western blot and immunohistochemical studies, Nox2 expression was found in normal human cardiomyocytes. In patients with AMI, a significant increase in Nox2 expression was found both in viable and in jeopardised cardiomyocytes in the infarcted area. In addition, in the "remote from infarction" area, Nox2 expression was present in cardiomyocytes, but was not increased., Conclusions: Nox2 or its homologue(s) is expressed in normal and jeopardised human cardiomyocytes. This expression is increased in patients with AMI, suggesting a role for this ROS producing Nox2 homologue(s) in the human heart after AMI.

Objectives: The effect of topical vascular endothelial growth factor (VEGF) on post-surgical tracheal healing using various reconstruction materials was studied, with particular regard to prevention of granulation tissue or fibrosis., Methods: Twenty-four New Zealand White rabbits underwent survival surgery using autograft patches (n=6), xenopericardium patches (n=6), intraluminal Palmaz wire stents (n=6), and controls (n=6). Autograft and pericardial half-patches were soaked in topical VEGF (5 microg/ml over 30 min) and saline before reimplantation. Stents and controls received circumferential injections of VEGF and saline in the tracheal wall. At 1-4 months postoperatively, specimens of sacrificed animals were stained with anti-VEGF antibody, followed by morphological and immunohistochemical examination., Results: Rabbits with autografts and controls fared well until planned sacrifice. After xenopericardium repair, obstructive intraluminal granulation tissue led to early sacrifice in three rabbits. Stent insertion led to earlier death from airway obstruction in all six rabbits. Topical VEGF reduced granulation tissue after pericardial repair and fibrosis in all repairs except in stents. Remarkably, VEGF-pretreated half-patches and saline half-patches stained similarly high for VEGF, suggesting also local production of VEGF, probably in plasmacells, and in submucosal glands., Conclusions: Autograft repair induces the least granulation tissue and fibrosis, and the best healing pattern. Stents rapidly induced critical airway obstruction, unhindered by VEGF, leading to premature death. Tracheal pretreatment with topical VEGF reduces postoperative fibrosis after autograft and pericardial patch repairs, and reduces granulation tissue after xenopericardium repair. In time, VEGF is probably locally produced, although its potential role in tracheal healing remains to be established.

Recent studies indicate that, in addition to necrosis, apoptosis also plays a role in the process of tissue damage after myocardial infarction, which has pathological and therapeutic implications. This review article will discuss studies in which the role and mechanisms of apoptosis in myocardial infarction were analysed in vivo and in vitro in humans and in animals.

Reactive oxygen species play an important role in a variety of (patho)physiological vascular processes. Recent publications have produced evidence of a role for putative non-phagocyte NADP oxidase(s) in the vascular production of reactive oxygen species. In the present review, we discuss the detection of the different components of NADP oxidase(s) in the vascular system, together with the putative role of reactive oxygen species produced by vascular NADPH oxidase(s), in both in vitro and in vivo studies.

This study was financially supported by the Netherlands Heart Foundation, grant numbers 93-119 and 97-088. Dr. Niessen is a recipient of the Dr. E. Dekker programme of the Netherlands Heart Foundation (D99025).

Objectives: From animal and clinical studies it is known that prevention of 'over-distention' of vein grafts by using extravascular support ameliorates the arterialization process in vein grafts with subsequent more favorable patency. The most ideal support is a biodegradable, porous, elastic graft (Biomaterials, 15 (1994) 83). However, a specific graft meeting these criteria is not available yet. Fibrin glue on the other hand, although used for other purposes in cardiac surgery, theoretically meets the criteria for ideal extravascular support. In this ex vivo study, we evaluated the possible beneficial effect of perivenous application of fibrin glue., Methods: Segments of human vein graft obtained during CABG procedures in 14 consecutive patients were placed in a side loop of the extracorporeal perfusion circuit. In this way the study vein grafts did meet identical circumstances as the vein grafts implanted. Perfusion in the loop was started with a flow just enough to counteract the collapse of the vein, usually about 8 mm Hg, and alternately around the segments fibrin glue was applied or no perivenous support was administered as control. After 1 min of soldification, perfusion was started with a pressure of about 60 mm Hg (non-pulsatile flow). Perfusion was maintained for 60 min, after which the grafts were collected for light microscopic and electron microscopic assessment., Results: Light microscopy and electron microscopy showed remarkable attenuation of endothelial cell loss and less injury of smooth muscle cells of the circular muscle layer of the media in the fibrin glue supported vein grafts compared to the non-supported group., Conclusion: Fibrin glue is able to accomplish adequate external vein graft support, preventing overdistention, in an ex vivo model. This provides a basis for clinical application. Further investigation is necessary to evaluate long-term effects.

This report hypothesises an active role for the acute phase protein, C reactive protein (CRP), in local inflammatory reactions. This was studied in infarction sites from liver and kidney in a patient who died as a result of multiple complications after cholecystectomy. In this patient, a general acute phase protein reaction was induced, with an increase in plasma CRP. In infarction sites of kidney and liver, colocalisation of CRP and activated complement were found, whereas non-infarct sites were negative for CRP and complement. These results suggest that CRP directly participates in local inflammatory processes, possibly via complement activation, after binding of a suitable ligand.

The aim of this study was to determine whether the morphology of the muscular femoral artery in patients with atherosclerosis and hyperhomocysteinemia differs from that of atherosclerotic vessels from patients with normal homocysteine levels. Whole-vessel biopsies of the superficial femoral artery were taken from patients with symptomatic atherosclerotic disease with and without hyperhomocysteinemia and from patients without atherosclerosis from traumatic amputations. The morphology of these specimens was studied qualitatively by light and electron microscopy and quantitatively by light microscopy in combination with a video overlay system. Atherosclerotic lesions in patients with hyperhomocysteinemia were morphologically similar to those in patients with normal homocysteine levels, except for a significantly decreased smooth muscle cell/extracellular matrix ratio of the media in hyperhomocysteinemic patients (P=0.02 versus normohomocysteinemic atherosclerotic group and P=0.001 versus group without a history of cardiovascular disease). Hyperhomocysteinemia is associated with a significant decrease of the smooth muscle cell/extracellular matrix ratio of the media of muscular femoral arteries without significant changes in medial thickness. Further investigations should concentrate on the cause of this newly discovered phenomenon and its impact on vascular compliance.