Normal values for intima-media thickness of the common carotid artery--an update following a novel risk factor profiling.

BACKGROUND: There is a widely approved influence of novel risk factors like the body fat distribution and the associated metabolic syndrome, subclinical inflammation, insulin resistance and prediabetic disturbances in glucose metabolism on the progression of atherosclerosis. Former studies examining normal values for intima-media thickness (IMT) did not consider all of these new study results in detail. We therefore aimed to assess an update on age- and gender-specific normal values for IMT accounting for these novel risk factors. PATIENTS AND METHODS: We evaluated IMT by high-resolution ultrasound (13 MHz) on the far wall of the common carotid artery in 801 subjects without cardiovascular disease (428 women aged 46.2±12.9 years; 373 men aged 47.3±13.3 years). After precise evaluation and exclusion of 14 cardiovascular risk factors, 90% limits of IMT were determined by parametric statistics. RESULTS: The reference limits of IMT according to the age classes 18-29, 30-39, 40-49 and 50-59 years were estimated as 0.47, 0.59, 0.67 and 0.70 mm in women and 0.47, 0.62, 0.72 and 0.80 mm in men. CONCLUSIONS: Age and gender-specific normal values for IMT are lower than reported in former studies after additionally accounting for novel cardiovascular risk factors. The still widely regarded upper IMT limit of 1 mm must be strictly regarded as obsolete.

Fetuin-A influences vascular cell growth and production of proinflammatory and angiogenic proteins by human perivascular fat cells.

AIMS/HYPOTHESIS: Fetuin-A (alpha2-Heremans-Schmid glycoprotein), a liver-derived circulating glycoprotein, contributes to lipid disorders, diabetes and cardiovascular diseases. In a previous study we found that perivascular fat cells (PVFCs) have a higher angiogenic potential than other fat cell types. The aim was to examine whether fetuin-A influences PVFC and vascular cell growth and the expression and secretion of proinflammatory and angiogenic proteins, and whether TLR4-independent pathways are involved. METHODS: Mono- and co-cultures of human PVFCs and endothelial cells were treated with fetuin-A and/or palmitate for 6-72 h. Proteins were quantified by ELISA and Luminex, mRNA expression by real-time PCR, and cell growth by BrDU-ELISA. Some PVFCs were preincubated with a nuclear factor κB NFκBp65 inhibitor, or the toll-like receptor 4 (TLR4) inhibitor CLI-095, or phosphoinositide 3-kinase (PI3K)/Akt inhibitors and/or stimulated with insulin. Intracellular forkhead box protein O1 (FoxO1), NFκBp65 and inhibitor of κB kinase ß (IKKß) localisation was visualised by immunostaining. RESULTS: PVFCs expressed and secreted IL-6, IL-8, plasminogen activator inhibitor 1 (PAI-1), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF)-BB, monocyte chemotactic protein-1 (MCP-1), vascular endothelial growth factor (VEGF), placental growth factor (PLGF) and hepatocyte growth factor (HGF). Fetuin-A upregulated IL-6 and IL-8, and this was potentiated by palmitate and blocked by CLI-095. Immunostaining and electrophoretic mobility shift assay (EMSA) showed partial NFκBp65 activation. MCP-1 was upregulated and blocked by CLI-095, but not by palmitate. However, HGF was downregulated, which was slightly potentiated by palmitate. This effect persisted after TLR4 pathway blockade. Stimulation of insulin-PI3K-Akt signalling by insulin resulted in nuclear FoxO1 extrusion and HGF upregulation. Fetuin-A counteracted these insulin effects. CONCLUSIONS/INTERPRETATION: Fetuin-A and/or palmitate influence the expression of proinflammatory and angiogenic proteins only partially via TLR4 signalling. HGF downregulation seems to be mediated by interference with the insulin-dependent receptor tyrosine kinase pathway. Fetuin-A may also influence angiogenic and proinflammatory proteins involved in atherosclerosis.

Perfusion measurements of the calf in patients with peripheral arterial occlusive disease before and after percutaneous transluminal angioplasty using MR arterial spin labeling.

PURPOSE: To evaluate muscle perfusion in patients with peripheral arterial occlusive disease (PAOD) before and after percutaneous transluminal angioplasty (PTA) of the limb by means of MR arterial spin labeling (ASL) perfusion measurements during reactive hyperemia. MATERIALS AND METHODS: Ten patients with symptomatic PAOD affecting the iliac or femoral vessels were investigated before and after PTA. A pseudo-continuous arterial spin labeling (PCASL) MR technique was applied. Perfusion was measured in soleus and tibialis anterior muscle during reactive hyperemia. Key parameters such as mean perfusion value (Phyp ), time-to-peak (TTP) and duration of hyperemia (Thyp ) describing the perfusion signal curve were examined. RESULTS: Between baseline and post-PTA, Phyp increased in both muscle groups. At the same time, TTP and Thyp decreased in both muscle groups. At the same time the clinically assessed ankle brachial index (ABI) increased from 0.56 ± 0.10 to 0.83 ± 0.15. The impaired pain-free walking distance improved in all patients. CONCLUSION: PCASL MRI can detect changes of the key perfusion parameters Phyp , TTP, and Thyp after successful PTA of the calf muscles during reactive hyperemia and seems to be a promising tool for monitoring of interventional treatments.

Different effects of bariatric surgery on epigenetic plasticity in skeletal muscle of individuals with and without type 2 diabetes.

AIM: Bariatric surgery is highly effective for the treatment of obesity in individuals without (OB1) and in those with type 2 diabetes (T2D2). However, whether bariatric surgery triggers similar or distinct molecular changes in OB and T2D remains unknown. Given that individuals with type 2 diabetes often exhibit more severe metabolic deterioration, we hypothesized that bariatric surgery induces distinct molecular adaptations in skeletal muscle, the major site of glucose uptake, of OB and T2D after surgery-induced weight loss. METHODS: All participants (OB, n = 13; T2D, n = 13) underwent detailed anthropometry before and one year after the surgery. Skeletal muscle biopsies were isolated at both time points and subjected to transcriptome and methylome analyses using a comprehensive bioinformatic pipeline. RESULTS: Before surgery, T2D had higher fasting glucose and insulin levels but lower whole-body insulin sensitivity, only glycemia remained higher in T2D than in OB after surgery. Surgery-mediated weight loss affected different subsets of genes with 2,013 differentially expressed in OB and 959 in T2D. In OB differentially expressed genes were involved in insulin, PPAR signaling and oxidative phosphorylation pathways, whereas ribosome and splicesome in T2D. LASSO regression analysis revealed distinct candidate genes correlated with improvement of phenotypic traits in OB and T2D. Compared to OB, DNA methylation was less affected in T2D in response to bariatric surgery. This may be due to increased global hydroxymethylation accompanied by decreased expression of one of the type 2 diabetes risk gene, TET2, encoding a demethylation enzyme in T2D. CONCLUSION: OB and T2D exhibit differential skeletal muscle transcriptome responses to bariatric surgery, presumably resulting from perturbed epigenetic flexibility.

4-1BB ligand modulates direct and Rituximab-induced NK-cell reactivity in chronic lymphocytic leukemia.

NK cells play an important role in tumor immunosurveillance and largely contribute to the therapeutic success of anti-tumor antibodies like Rituximab. Here, we studied the role of the TNF family member 4-1BB ligand (4-1BBL) during the interaction of NK cells with chronic lymphocytic leukemia (CLL) cells. 4-1BBL was highly expressed on patient B-CLL cells in all 56 investigated cases. Signaling via 4-1BBL following interaction with 4-1BB, which was detected on NK cells of CLL patients but not healthy individuals, led to the release of immunoregulatory cytokines including TNF by CLL cells. CLL patient sera contained elevated levels of TNF and induced 4-1BB upregulation on NK cells, which in turn impaired direct and Rituximab-induced NK-cell reactivity against 4-1BBL-expressing targets. NK-cell reactivity was not only enhanced by blocking the interaction of NK cell-expressed 4-1BB with 4-1BBL expressed by CLL cells, but also by preventing 4-1BB upregulation on NK cells via neutralization of TNF in patient serum with Infliximab. Our data indicate that 4-1BBL mediates NK-cell immunosubversion in CLL, and thus might contribute to the reportedly compromised efficacy of Rituximab to induce NK-cell reactivity in the disease, and that TNF neutralization may serve to enhance the efficacy of Rituximab treatment in CLL.

MiR-205 is up-regulated in islets of diabetes-susceptible mice and targets the diabetes gene Tcf7l2.

AIM: MicroRNAs play an important role in the maintenance of cellular functions by fine-tuning gene expression levels. The aim of the current study was to identify genetically caused changes in microRNA expression which associate with islet dysfunction in diabetic mice. METHODS: To identify novel microRNAs involved in islet dysfunction, transcriptome and miRNome analyses were performed in islets of obese, diabetes-susceptible NZO and diabetes-resistant B6-ob/ob mice and results combined with quantitative trait loci (QTL) and functional in vitro analysis. RESULTS: In islets of NZO and B6-ob/ob mice, 94 differentially expressed microRNAs were detected, of which 11 are located in diabetes QTL. Focusing on conserved microRNAs exhibiting the strongest expression difference and which have not been linked to islet function, miR-205-5p was selected for further analysis. According to transcriptome data and target prediction analyses, miR-205-5p affects genes involved in Wnt and calcium signalling as well as insulin secretion. Over-expression of miR-205-5p in the insulinoma cell line INS-1 increased insulin expression, left-shifted the glucose-dependence of insulin secretion and supressed the expression of the diabetes gene TCF7L2. The interaction between miR-205-5p and TCF7L2 was confirmed by luciferase reporter assay. CONCLUSION: MiR-205-5p was identified as relevant microRNA involved in islet dysfunction by interacting with TCF7L2.

Polymorphisms in miRNA binding sites involved in metabolic diseases in mice and humans.

Type 2 diabetes and obesity are well-studied metabolic diseases, which are based on genetic and epigenetic alterations in combination with an obesogenic lifestyle. The aim of this study was to test whether SNPs in miRNA-mRNA binding sites that potentially disrupt binding, elevate the expression of miRNA targets, which participate in the development of metabolic diseases. A computational approach was developed that integrates transcriptomics, linkage analysis, miRNA-target prediction data, and sequence information of a mouse model of obesity and diabetes. A statistical analysis demonstrated a significant enrichment of 566 genes for a location in obesity- and diabetes-related QTL. They are expressed at higher levels in metabolically relevant tissues presumably due to altered miRNA-mRNA binding sites. Of these, 51 genes harbor conserved and impaired miRNA-mRNA-interactions in human. Among these, 38 genes have been associated to metabolic diseases according to the phenotypes of corresponding knockout mice or other results described in the literature. The remaining 13 genes (e.g. Jrk, Megf9, Slfn8 and Tmem132e) could be interesting candidates and will be investigated in the future.

Reduced insulin clearance is linked to subclinical atherosclerosis in individuals at risk for type 2 diabetes mellitus.

Hyperglycemia and insulin resistance contribute to vascular damage and are regulated by different pathophysiological processes. The aim of the study was to systematically investigate the relative contributions of multiple fasting state- and oral glucose tolerance test (oGTT)-derived glycemic traits to carotid intima-media thickness (cIMT), a surrogate parameter of subclinical atherosclerosis, in individuals with increased risk for type 2 diabetes mellitus (T2D). 667 volunteers (417 women and 250 men, mean age 44.1 years), who were free of cardiovascular disease (CVD), were included in this cross-sectional study. Glucose tolerance, insulin sensitivity, insulin secretion and insulin clearance were assessed by frequently sampled 75 g oGTT. CIMT was measured by high-resolution ultrasound. Insulin clearance was associated with cIMT in univariate analysis (ßst = - 0.17, p < 0.0001) and in a stepwise regression analysis on 15 variables possibly affecting cIMT, age (r2 = 0.3923, p < 0.0001), insulin clearance (r2 = 0.4564, p < 0.0001), systolic blood pressure (r2 = 0.4733, p < 0.0001), body mass index (BMI) (r2 = 0.4804, p = 0.002), gender (r2 = 0.4831, p = 0.013), and fasting insulin clearance (r2 = 0.4857, p = 0.030) turned out to be significant determinants of cIMT. In a cross-validated model resulting from this analysis, insulin clearance was found to be an independent determinant of cIMT (ßst = - 0.16, p < 0.0001) even after adjusting for traditional CVD risk factors. Reduced insulin clearance may be an early marker of damage on the vasculature, independent of classical CVD risk factors. Reduced insulin clearance should be considered with regard to vascular insulin resistance.

Ultrafast whole-body MR angiography with two-dimensional parallel imaging at 3.0 T: feasibility study.

The study was approved by the local ethics committee, and informed consent was provided by all participants prior to the examination. The aim of the study was to assess the feasibility of whole-body three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiography with parallel imaging in the phase- and section-encoding directions (ie, integrated parallel acquisition technique [iPAT(2); Siemens, Erlangen, Germany]) for all anatomic imaging stations in combination with a single injection of contrast material. Whole-body contrast-enhanced MR angiography was performed in 23 patients at 3.0 T. Images were evaluated by two independent observers for quality on a four-point scale (where a score of 1 indicated poor image quality and a score of 4, excellent image quality); signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for representative vessel regions in each station. Mean image quality scores were 3.13 +/- 1.15 (standard deviation) and 3.17 +/- 1.14 for observers 1 and 2, respectively (kappa = 0.81). Signal intensity measurements revealed mean SNR values between 36.2 +/- 8.0 and 56.2 +/- 17.7 and mean CNR values between 29.0 +/- 7.4 and 48.2 +/- 15.7. The data suggest that contrast-enhanced MR angiography with iPAT(2) is feasible for whole-body applications and allows acquisition of 3D data sets with adequate spatial resolution within short measurement times, facilitating a single injection of contrast material.

Visceral Adiposity Index as an Independent Marker of Subclinical Atherosclerosis in Individuals Prone to Diabetes Mellitus.

AIM: The visceral adiposity index (VAI) has been proposed as an estimate of visceral adipose tissue (VAT) mass and as an indicator of VAT dysfunction. Both parameters are associated with cardiometabolic risk, including insulin resistance. In this study, we investigated whether VAI is associated with subclinical atherosclerosis in subjects who were free of cardiovascular disease but were at risk of developing diabetes mellitus. METHODS: A total of 731 adults with a median age of 47 years old without diabetes mellitus were included in this cross-sectional study. The anthropometric data, blood pressure, and lipid profiles of 398 women and 333 men were measured. All subjects underwent an oral glucose tolerance test, and carotid intima-media thickness (cIMT) was evaluated by ultrasound. Insulin resistance was estimated using the homeostatic model assessment of insulin resistance (HOMA-IR). RESULTS: VAI and HOMA-IR (ßst=0.44, p＜0.0001), VAI and cIMT (ßst=0.17, p＜0.0001), and HOMA-IR and cIMT (ßst=0.09, p=0.0127) were correlated with each other. After adjusting for cofounding variables, VAI is still correlated with HOMA-IR (ßst=0.42, p＜0.0001). Furthermore, VAI (ßst=0.07, p=0.0392) but not HOMA-IR (ßst=0.03, p=0.37) was correlated with cIMT independently of other established cardiovascular risk factors. CONCLUSION: The calculation of VAI may provide a better estimation of subclinical atherosclerosis than the calculation of HOMA-IR.

Comparison between a linear versus a macrocyclic contrast agent for whole body MR angiography in a clinical routine setting.

BACKGROUND: Previous experiences of whole body MR angiography are predominantly available in linear 0.5 M gadolinium-containing contrast agents. The aim of this study was to compare image quality on a four-point scale (range 1-4) and diagnostic accuracy of a 1.0 M macrocyclic contrast agent (gadobutrol, n = 80 patients) with a 0.5 M linear contrast agent (gadopentetate dimeglumine, n = 85 patients) on a 1.5 T whole body MR system. Digital subtraction angiography served as standard of reference. RESULTS: All examinations yielded diagnostic image quality. There was no significant difference in image quality (3.76 +/- 0.3 versus 3.78 +/- 0.3, p = n.s.) and diagnostic accuracy observed. Sensitivity and specificity of the detection of hemodynamically relevant stenoses was 93%/95% in the gadopentetate dimeglumine group and 94%/94% in the gadobutrol group, respectively. CONCLUSION: The high diagnostic accuracy of gadobutrol in the clinical routine setting is of high interest as medical authorities (e.g. the European Agency for the Evaluation of Medicinal Products) recommend macrocyclic contrast agents especially to be used in patients with renal failure or dialysis.

A practical approach for bridging anticoagulation after mechanical heart valve replacement.

BACKGROUND AND AIM OF THE STUDY: Following mechanical heart valve replacement, patients may require a form of 'bridging' anticoagulation to prevent valve-associated thromboembolism until oral vitamin K antagonists take effect. In 2000, the present authors changed their bridging protocol to a fixed dose of 40 mg enoxaparin twice daily (b.i.d., subcutaneous), regardless of the patient's body weight and renal function. The study aim was to evaluate the feasibility of this protocol with regards to thromboembolism, hemorrhage and other valve-associated adverse effects. METHODS: Between April 2000 and December 2004, a total of 256 consecutive patients who had undergone mechanical heart valve replacement were enrolled into this retrospective study. All patients received 40 mg enoxaparin b.i.d., subcutaneously, as bridging anticoagulation for a mean of 6.7 days, commencing at a mean of 3.8 days (range: 2-42 days) after surgery. This was approximately 55% (range: 32-95%) of the recommended dose considered to be safe in this setting. RESULTS: A total of 18 (7%) minor bleeding events and two (0.7%) arterial thromboses were seen to arise from previously existing high-grade (>90%) stenosis of the affected vessels. At discharge, all prosthetic valves showed regular, echocardiographically confirmed, function. The mean follow up was 38.6 days (range: 8-106 days). Mitral valve replacement (p = 0.005) was shown to be a significant risk factor for minor bleeding, but not for thromboembolism. None of the other risk factors reached significance when testing for minor bleeding or major thromboembolic events. CONCLUSION: Within the special setting of postoperative cardiac surgery, this modified anticoagulation protocol appears feasible and safe, with efficacy equivalent to that of full-dose protocols reported elsewhere using either low-molecular-weight or unfractionated heparin. By using this protocol, the effort required to bridge patients to effective oral anticoagulation was greatly reduced as there was no requirement for repeated laboratory measurements and dose adjustments. A prospective multi-center study should be conducted to confirm the hypothesis that the first bridging period after prosthetic heart valve replacement with extracorporeal circulation is different, and permits the use of a bridging protocol with a lower anticoagulation dose.

Periaortic Adipose Tissue Compared With Peribrachial Adipose Tissue Mass as Markers and Possible Modulators of Cardiometabolic Risk.

Increased perivascular fat mass contributes to cardiometabolic risk (CMR). High peribrachial adipose tissue (PBAT) associates with insulin resistance independently of established CMR parameters. It is unknown to what extent periaortic adipose tissue (PAAT) may have a similar impact. In 95 participants, precise quantification of total adipose tissue, PBAT, PAAT, visceral adipose tissue (VAT), and liver fat (LF) content was performed by whole-body magnetic resonance imaging. Insulin sensitivity was determined by oral glucose tolerance test and carotid intima-media thickness (cIMT) by high-resolution ultrasound. In univariate analyses, PAAT correlated with PBAT (ß = .65, P < .0001). A negative correlation of PAAT (ß = -.35, P = .0002) and PBAT (ß = -.43, P < .0001) with insulin sensitivity was observed. While in a stepwise forward regression analysis the relationship of PAAT with insulin sensitivity was no longer significant after adjustment for VAT, LF content, and other CMR factors ( P = 0.42), PBAT still correlated with insulin sensitivity ( r2 = .35, P = .01). The association between PAAT and cIMT (ß = .49, P < .0001) remained significant after adjustment for these variables ( r2 = .42, P = .0001). Although PAAT and PBAT strongly correlate, PAAT is not associated with insulin resistance, but with cIMT. Therefore, PAAT and PBAT may act differently as possible modulators of insulin resistance and subclinical atherosclerosis.

Antiangiogenesis mediates cisplatin-induced peripheral neuropathy: attenuation or reversal by local vascular endothelial growth factor gene therapy without augmenting tumor growth.

BACKGROUND: Toxic neuropathies induced by cisplatin and other chemotherapeutic agents are important clinical problems because of their high incidence, their lack of effective treatment, and the fact that neuropathy represents a dose-limiting factor for these therapies. The pathogenic basis for toxic neuropathies induced by chemotherapeutic agents has not been completely elucidated. METHODS AND RESULTS: We investigated the hypothesis that experimental toxic neuropathy results from an antiangiogenic effect of these drugs, resulting in destruction of the vasa nervorum, and accordingly that the neuropathy could be prevented or reversed by locally administered VEGF gene transfer without augmenting tumor growth. In an animal model of cisplatin-induced neuropathy, nerve blood flow was markedly attenuated, and there was a profound reduction in the number of vasa nervorum associated with marked endothelial cell apoptosis, resulting in a severe peripheral neuropathy with focal axonal degeneration characteristic of ischemic neuropathy. After intramuscular gene transfer of naked plasmid DNA encoding VEGF-1 in animals with an established neuropathy, vascularity and blood flow returned to levels similar to those of control rats, peripheral nerve function was restored, and histological nerve architecture was normalized. Gene therapy administered in parallel with cisplatin chemotherapy completely attenuated endothelial cell apoptosis and inhibited destruction of nerve vasculature, deterioration of nerve function, and axonal degeneration. In a rat tumor model, VEGF gene transfer administered locally did not alter tumor growth or vascularity. CONCLUSIONS: These findings implicate microvascular damage as the basis for toxic neuropathy induced by cisplatin and suggest that local angiogenic gene therapy may constitute a novel prevention or treatment for this disorder without augmenting tumor growth or vascularization.

Rapid effects of rosiglitazone treatment on endothelial function and inflammatory biomarkers.

BACKGROUND: Antidiabetic thiazolidinediones (TZDs), like rosiglitazone or pioglitazone, improve endothelial function in patients with type 2 diabetes or metabolic syndrome, but it is currently unknown, whether these beneficial effects of TZDs depend on their metabolic action or may be caused by direct effects on the endothelium. Therefore, the present study examined whether short-term rosiglitazone treatment influences endothelium-dependent vasodilation as well as serum levels of vascular disease biomarkers in healthy, nondiabetic subjects. METHODS AND RESULTS: Short-term treatment (21 days) of healthy subjects (n = 10) did not significantly change blood glucose levels or lipid profile. In contrast, rosiglitazone significantly increased flow-mediated, endothelium-dependent vasodilation already within the first day from 5.3+/-2.7% at baseline to 7.8+/-2.6%, further increasing it to 9.4+/-3.0% at day 21. In addition, the early improvement of endothelium-dependent vasodilation was paralleled by a rapid reduction of serum levels of the biomarkers C-reactive protein (CRP), serum amyloid A (SAA), and sE-selectin. Moreover, after drug withdrawal all markers remained suppressed for the whole follow-up period of 7 days. In contrast, rosiglitazone treatment did not significantly affect tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, sICAM-1, sVCAM-1, and sCD40L levels. CONCLUSIONS: Our study suggests a direct effect of TZD treatment on endothelial function and inflammatory biomarkers of arteriosclerosis, promoting the concept that TZDs, independent of their metabolic action, may exhibit protective effects in the vessel wall.

[Thromboembolic complication after ovarian stimulation]. / Thromboembolische Komplikation nach ovarieller Stimulation--Fall 1/2016.

HISTORY AND ADMISSION FINDINGS: We report on two pregnant women with dyspnoe and thoracic pain in the context of an ovarian hyperstimulation syndrome. INVESTIGATIONS: Both patients had pleural effusions. The first patient was diagnosed with pulmonary embolism via computer tomography. In the second patient, thrombosis of the upper part of the body including intracranial thrombosis was revealed via magnetic resonance and ultrasound imaging. In both cases, thrombosis was caused by ovarian hyperstimulation. DIAGNOSIS, TREATMENT AND COURSE: Therapy included anticoagulation with low molecular weight heparin and a drainage of the pleural effusions. One patient had an abortion in the 8th week of pregnancy, the second patient gave birth to two healthy children. CONCLUSIONS: Ovarian hyperstimulation syndrome is a potentially life-threatening disease, which should be considered as a differential diagnosis of causes of thromboembolic events in early pregnancy.

Statin therapy accelerates reendothelialization: a novel effect involving mobilization and incorporation of bone marrow-derived endothelial progenitor cells.

BACKGROUND: Primary and secondary prevention trials suggest that statins possess favorable effects independent of cholesterol reduction. We investigated whether statin therapy may also accelerate reendothelialization after carotid balloon injury. METHODS AND RESULTS: Simvastatin treatment in 34 male Sprague-Dawley rats accelerated reendothelialization of the balloon-injured arterial segments (reendothelialized area at 2 weeks, 12.3+/-1.8 versus 5.4+/-1.1 mm2, P< 0.01) and resulted in a dose-dependent (0.2 or 1 mg/kg IP) significant reduction in neointimal thickening at 2, 3, and 4 weeks compared with saline-injected controls (n=18). To elucidate the mechanism, we investigated the contribution of bone marrow-derived endothelial progenitor cells (EPCs) by bone marrow transplantation from Tie2/lacZ mice to background mice or nude rats. X-gal staining of mouse carotid artery specimens revealed a 2.9-fold increase in the number of beta-gal-positive cells per square millimeter appearing on the carotid artery luminal surface at 2 weeks, and double-fluorescence immunohistochemistry disclosed a significant 5-fold increase in the number of double-positive cells (beta-gal, isolectin B4) on the luminal surface in carotid arteries of statin-treated nude rats (20+/-3 versus 4+/-1 cells/mm surface length, P<0.005). Statins increased circulating rat EPCs (2.4-fold at 2 weeks and 2.5-fold at 4 weeks, P<0.001) and induced adhesiveness of cultured human EPCs by upregulation of the integrin subunits alpha5, beta1, alpha(v), and beta5 of human EPCs as shown by reverse transcription-polymerase chain reaction and fluorescence-activated cell sorting. CONCLUSIONS: These findings establish additional mechanisms by which statins may specifically preempt disordered vascular wall pathology and constitute physiological evidence that EPC mobilization represents a functionally relevant consequence of statin therapy.

Acute effect of rheopheresis on peripheral endothelial dysfunction in patients suffering from sudden hearing loss.

Single low density lipoprotein (LDL) fibrinogen apheresis has shown beneficial effects in the treatment of patients with sudden sensorineural hearing loss (SSHL). Pathophysiologically, a microcirculatory disorder of the inner ear, probably caused by disturbed endothelial function, is discussed as a final common pathway of a variety of SSHL etiologies. Thus, we carried out a prospective pilot study on the efficacy of Rheopheresis on vascular function in these patients, embedded into an ongoing randomized controlled multicenter trial investigating the efficacy of Rheopheresis for the treatment of SSHL. Potential modulation of systemic endothelial dysfunction by Rheopheresis was examined by measuring flow-associated vasodilatation of the brachial artery (according to the criteria of the American College of Cardiology) in a small group of patients suffering from SSHL (N=6, 5m/1f, mean age 56+/-11 years) within the last 3 days. At baseline, five of the six patients with acute hearing loss showed endothelial dysfunction as evidenced by diminished flow-mediated vasodilatation (FMD<5%). After a single Rheopheresis treatment, flow-mediated vasodilatation improved significantly (from 3.9+/-3.6% to 7.2+/-2.4%, P=0.05, mean+/-SD, two-sided paired T-test). This was paralleled by a reduction in fibrinogen (364+/-216 mg/dL to 142+/-96 mg/dL, P=0.03), total cholesterol (228+/-23 to 98+/-10, P<0.0001) and LDL cholesterol levels (153+/-8 mg/dL to 83+/-23 mg/dL, P<0.01). Based on this case series we conclude that single Rheopheresis treatment might have an acute beneficial effect on endothelial dysfunction in patients suffering from SSHL.

Insulin resistant young subjects at risk of accelerated atherosclerosis exhibit a marked reduction in peripheral endothelial function early in life but not differences in intima-media thickness.

Reduced bio-availability of nitric oxide leading to disturbed flow mediated (endothelial dependent) vasodilation (FMD) has been shown to be an early functional abnormality of the vascular system in insulin resistant individuals and other subjects at high risk for accelerated atherosclerosis. In addition, an increase of the intima-media thickness (IMT) is regarded as an early marker of morphological alterations of the vessel wall. Whether endothelial dysfunction (ED) is evident already at an early stage when morphological changes of the vessel wall are not apparent is still an open question. We, therefore, examined IMT and peripheral endothelial function in a group of young insulin resistant subjects in a cross-sectional study and compared these results with a metabolically healthy (insulin sensitive) control group. We measured IMT (distal common carotid arteries), endothelium-dependent and endothelium-independent vasodilation (flow mediated and glyceroltrinitrate induced vasodilation of the brachial artery) non-invasively with high resolution ultrasound (13 MHz) in 91 young normoglycemic subjects (40/51 M/F, median: 31 years, range 18-50 years). Insulin sensitivity was measured with a euglycemic, hyperinsulinemic glucose clamp. Despite a marked reduction in flow-mediated vasodilation in insulin resistant (IR) subjects (FMD: median 3.4%, range -4.0 to 12.5 in IR versus 6.6%, range -1.2 to 20.1% in insulin sensitive subjects; P = 0.017), there was no difference in endothelial independent vasodilation (16.3%, range 5.7-41.0% versus 16.1%, range 0.5-39.2%) and in IMT (0.50 mm, range 0.39-0.66 and 0.51, 0.40-0.70 mm, respectively). These data suggest that ED can be detected very early in the life of insulin resistant subjects whereas no significant structural changes, indicated by a thickening of the intima-media layer, could be found. We therefore conclude that for identification of subjects with a high risk for accelerated atherosclerosis at an early stage, measurement of flow mediated vasodilation of the brachial artery may be more helpful than measuring thickness of the vascular wall.