Patients with in-stent restenoses

Aims: We compared the intracoronary β-brachytherapy using a liquid rhenium-188 filled balloon with the slow-release, polymer-based, paclitaxel-eluting Taxus-Express stent for treatment of in-stent restenoses. Patients, methods: During the same study period, patients with restenoses in bare-metal stents were either treated with Taxus- Express stents (n = 50) or β-brachytherapy after successful angioplasty (n = 51). For brachytherapy 30 Gy in 0.5 mm tissue depth were administered. The irradiated segment exceeded the traumatized segment 7.5 mm on both sides. Primary endpoint was the minimal lumen diameter (MLD) at the target lesion at six months follow-up. Angiographic follow-up was available in 78% (n = 79/101) and clinical follow-up in all patients. Results: Baseline parameters did not differ statistically. The Taxus-Express stent resulted in a significantly larger MLD and a significantly lower percent diameter stenosis post intervention compared to β-brachytherapy, which both maintained until angiographic follow-up (primary endpoint 2.44 ± 0.74 mm versus 1.73 ± 0.74 mm, p <0.0001). Therefore, Taxus- Express stents were associated with a lower angiographic restenosis rate compared with β-brachytherapy, both for the target lesion (6.1% versus 17.4%) and the total segment (9.1% versus 23.9%). Moreover, use of Taxus-stent was associated with a clinical benefit based on a significantly lower MACE rate compared with β-brachytherapy (p <0.05). Conclusions: Paclitaxel-eluting Taxus- Express stents resulted in superior clinical and angiographic outcomes compared to intracoronary β-brachytherapy with a liquid 188Re filled balloon for treatment of restenosis within a bare-metal stent.

Signalling processes involved in C-peptide-induced chemotaxis of CD4-positive lymphocytes

Previous data from our group demonstrated that C-peptide induces chemotaxis of CD4-positive lymphocytes in-vitro, mediated by activation of G-protein and PI 3-kinase gamma, but additional signalling pathways involved in this process remained unexplored. In the present study we further analyze intracellular signalling pathways which lead to C-peptide-induced CD4-positive lymphocyte migration. We provide evidence that C-peptide-induced chemotaxis of CD4-positive lymphocytes is critically dependent on activation of Src-kinase and RhoA, Rac-1 and Cdc42 GTPases. Furthermore, C-peptide stimulates phosphorylation of PAK, LIMK and cofilin downstream of Rac-1 and Cdc42, leading to cofilin inactivation and actin filament stabilization. In addition, C-peptide induces ROCK kinase activity and MLC phosphorylation downstream of RhoA, thereby stimulating myosin mediated cell contraction. In contrast, C-peptide does not activate ERK1/2, p38 or Akt in CD4-positive lymphocytes. Our data support an active role of C-peptide in CD4-positive lymphocyte chemotaxis and elucidate molecular mechanisms in C-peptide-induced cell migration.

Systolic ventricular function in acute hypothyroidism: a study using Doppler echocardiography

The influence of thyroid state on left ventricular systolic function was studied in 11 patients (5 men, 6 women, aged 20-55 years) without cardiac disease, who had undergone total thyroidectomy and radioiodine treatment for thyroid cancer before. Pulsed-wave Doppler echocardiographic measuring of aortic blood flow and two-dimensional/time-motion (2D/M-mode) echocardiography were performed on two occasions once while the patients were mildly hyperthyroid on thyroxine replacement therapy and once when they were hypothyroid. During hypothyroidism left ventricular end-diastolic diameter decreased from 48 +/- 5 mm to 46 +/- 5 mm (p < 0.05). The diameter of the aortic ring, the left ventricular end-systolic diameter, the thickness of the interventricular septum and posterior wall, and fractional shortening did not differ significantly between the two studies. The following parameter of aortic blood flow changed significantly when passing from the hyperthyroid to the hypothyroid state: peak velocity (0.86 +/- 0.15 m/s versus 0.72 +/- 0.15 m/s, p < 0.01); mean velocity (0.49 +/- 0.08 m/s versus 0.44 +/- 0.08 m/s, p < 0.01); time- velocity integral (14.1 +/- 3.0 cm versus 12.3 +/- 3.1 cm, p < 0.05); stroke volume (43.0 +/- 9.7 ml versus 35.2 +/- 8.2 ml, p < 0.05); and preejection period (124 +/- 23 ms versus 147 +/- 21 ms, p < 0.01). Peak acceleration, mean acceleration, acceleration time and left ventricular ejection time did not change when the thyroid state was altered. It is concluded that left ventricular contractile function was not affected by acute hypothyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of the ST-segment in terms of principal components: application on multichannel magnetocardiographic recordings

Parameterization of the ST-segment is used as a tool for risk stratification for patients to suffer from ventricular tachycardia. This parameterization is performed in terms of Principal Component Analysis (PCA) applied on multichannel magnetocardiographic (MCG) recordings. 55-channel MCG was recorded from 14 normal persons, 10 patients with CHD, 14 patients with MI, and six patients with VT. We found a significantly (p < 0.05) lower PCA-score in patients with MI compared to normals. The lowest PCA-score was found in VT patients. Significant differences can be found between VT patients and normals and also between VT patients and CHD patients.

Integrated FDG PET-CT imaging improves staging in malignant pleural mesothelioma

AIM of this study was to investigate, how often TNM staging is changed in patients with malignant pleural mesothelioma (MPM) by the application of integrated PET-CT compared to computed tomography alone and how often these changes are clinically relevant.

PATIENTS, METHODS

We studied 17 patients (68 +/- 6 years, 8 women) with MPM. Integrated PET-CT scan and histological confirmation were performed in all patients.

RESULTS

Final histological diagnosis confirmed 9 epithelial type, 2 sarcomatoid type and 6 biphasic type MPM. Mean standardized uptake value (SUV) was 5.9 +/- 1.9 in epithelial MPM and 15.1 +/- 10.2 in sarcomatoid MPM. CT and PET-CT revealed discordances in 8/17 (47%) patients in TNM classification with 4/8 (50%) being clinically relevant. PET-CT led to downstaging in 5 (29%) and upstaging in 3 (18%) patients. Mean survival time tended to be higher in the subgroup of patients with lower mean SUV.

CONCLUSIONS

PET-CT seems to be a valuable tool in staging of MPM and leads to discordant findings in almost every second patient compared to CT alone. In many cases these differences are clinically relevant and have therapeutic consequences.

Pericardial synovial sarcoma mimicking pericarditis in findings of cardiac magnetic resonance imaging

We report a case of a 64-year-old woman with increasing shortness of breath due to massive pericardial effusion. Cardiac magnetic resonance imaging (CMRI) identified typical findings for pericarditis. Pericardectomy was needed due to suspicion of pericardial abscess formation. Histological examination of the resected tissue revealed an undifferentiated primary pericardial synovial sarcoma. The present case illustrates that pericardial tumours could be an important differential diagnosis to pericarditis, even if typical findings of pericarditis were present in CMRI.

Patients with in-stent restenoses: comparison of intracoronary beta-brachytherapy using a rhenium-188 filled balloon catheter with the polymer-based paclitaxel-eluting taxus-express stent

AIMS

We compared the intracoronary beta-brachytherapy using a liquid rhenium-188 filled balloon with the slow-release, polymer-based, paclitaxel-eluting Taxus-Express stent for treatment of in-stent restenoses.

PATIENTS, METHODS

During the same study period, patients with restenoses in bare-metal stents were either treated with Taxus-Express stents (n = 50) or beta-brachytherapy after successful angioplasty (n = 51). For brachytherapy 30 Gy in 0.5 mm tissue depth were administered. The irradiated segment exceeded the traumatized segment 7.5 mm on both sides. Primary endpoint was the minimal lumen diameter (MLD) at the target lesion at six months follow-up. Angiographic follow-up was available in 78% (n = 79/101) and clinical follow-up in all patients.

RESULTS

Baseline parameters did not differ statistically. The Taxus-Express stent resulted in a significantly larger MLD and a significantly lower percent diameter stenosis post intervention compared to beta-brachytherapy, which both maintained until angiographic follow-up (primary endpoint 2.44 +/- 0.74 mm versus 1.73 +/- 0.74 mm, p < 0.0001). Therefore, Taxus-Express stents were associated with a lower angiographic restenosis rate compared with beta-brachytherapy, both for the target lesion (6.1% versus 17.4%) and the total segment (9.1% versus 23.9%). Moreover, use of Taxus-stent was associated with a clinical benefit based on a significantly lower MACE rate compared with beta-brachytherapy (p < 0.05).

CONCLUSIONS

Paclitaxel-eluting Taxus-Express stents resulted in superior clinical and angiographic outcomes compared to intracoronary beta-brachytherapy with a liquid (188)Re filled balloon for treatment of restenosis within a bare-metal stent.

Improved non-invasive T-Staging in non-small cell lung cancer by integrated 18F-FDG PET/CT

AIM

In this prospective study, reliability of integrated (18)F-FDG PET/CT for staging of NSCLC was evaluated and compared to MDCT or PET alone.

PATIENTS, METHODS

240 patients (pts) with suspected NSCLC were examined using PET/CT. Of those patients 112 underwent surgery comprising 80 patients with NSCLC (T1 n = 26, T2 n = 37, T3 n = 11, T4 n = 6). Imaging modalities were evaluated independently.

RESULTS

MDCT, PET and PET/CT diagnosed the correct T-stage in 40/80 pts (50%; CI: 0.39-0.61), 40/80 pts (50%; CI: 0.39-0.61) and 51/80 pts (64%; CI: 0.52-0.74), respectively, whereas equivocal T-stage was found in 15/80 pts (19%; CI: 0.11-0.19), 12/80 pts (15%; CI: 0.08-0.25) and 4/80 pts (5%; CI: 0.01-0.12), respectively. With PET/CT, T-stage was more frequently correct compared to MDCT (p = 0.003) or PET (p = 0.019). Pooling stages T1/T2, T-stage was correctly diagnosed with MDCT, PET and PET/CT in 54/80 pts (68%; CI: 0.56-0.78), 56/80 pts (70%; CI: 0.59-0.80) and 65/80 pts (81%; CI: 0.71-0.89). T3 stage was most difficult to diagnose. T3 tumors were correctly diagnosed with MDCT in 2/11 pts (18%; CI: 0.02-0.52) versus 0/11 pts (0%; CI: 0.00-0.28) with PET and 5/11 pts (45%; CI: 0.17-0.77) with PET/CT. In all imaging modalities, there were no equivocal findings for T4 tumors. Of these, MDCT found the correct tumor stage in 4/6 pts (67%; CI: 0.22-0.95), PET in 3/6 pts (50%; CI: 0.12-0.88) and PET/CT in 5/6 pts (83%; CI: 0.36-0.99).

CONCLUSION

Integrated PET/CT was significantly more accurate for T-staging of NSCLC compared to MDCT or PET alone. The advantages of PET/CT are especially pronounced combining T1- and T2-stage as well as in advanced tumors.

Comparison of the slow-release polymerbased paclitaxel-eluting Taxus-Express stent with the bare-metal Express stent for saphenous vein graft interventions

BACKGROUND

The paclitaxel-eluting Taxus-Express stent is superior regarding angiographic and clinical outcome compared with its bare-metal platform for lesions in native coronary arteries. We studied the potential impact of the Taxus-Express stent in comparison with its bare-metal counterpart for treatment of lesions in saphenous vein grafts (SVGs). Furthermore, a meta-analysis was performed regarding use of drug-eluting (DES) vs bare-metal stents (BMS) in SVG lesions.

METHODS

We analyzed 13 consecutive patients who underwent percutaneous revascularization in SVG lesions using the slow-release, paclitaxel-eluting Taxus-Express stent. These lesions were balanced with 26 patients with SVG lesions treated with the bare-metal Express stent (BMS) in the preceding period. Angiographic follow-up was performed after 6 months, clinical follow-up after 6 and 12 months.

RESULTS

There were no statistically significant differences regarding clinical, procedural and angiographic parameters pre and post intervention. Binary restenoses occurred significantly less in the Taxus group compared with the BMS group (0% vs 34.6%; p=0.016). This translated into a significantly lower occurrence of major adverse cardiac events (death, Q-wave myocardial infarction, repeat target vessel revascularization) in the Taxus group compared with the BMS group at the 6-month (0% vs 26.9%, p=0.039) and 12-month follow-up (7.7% vs 38.5%, p=0.045). Multivariate predictors for freedom of binary restenosis were the reference diameter pre intervention and treatment with Taxus stents. Meta-analysis including 280 DES and 256 BMS patients revealed an odds ratio of 0.34 (95% confidence interval 0.21-0.54) for MACE and 0.26 (95% confidence interval 0.16-0.44) for target vessel revascularizations, both favoring DES.

CONCLUSIONS

We conclude that the use of the slow-release Taxus-Express stent has the potential to be superior regarding angiographic and clinical outcome compared with its bare-metal counterpart for treatment of SVG lesions within a 12-month follow-up. A large, randomized trial including a long follow-up period is now required to prove the results of the meta-analysis.

Use of integrated FDG PET/CT imaging in pulmonary carcinoid tumours

BACKGROUND

Integrated positron emission tomography (PET)/computed tomography (CT) scanners have been recently introduced in the diagnostic work-up of suspected pulmonary malignancy and demonstrate encouraging results in the staging of nonsmall-cell lung cancer.

OBJECTIVE

To evaluate the usefulness of integrated FDG PET/CT in pulmonary carcinoid tumours.

SETTING

University hospital.

METHODS

We studied 13 patients (mean age +/- 1 SD, 57 +/- 11 years) with pulmonary carcinoid tumours. All patients demonstrated a single pulmonary lesion. Integrated PET/CT scan and surgical resection were performed in all patients.

RESULTS

The pulmonary lesion size ranged from 1.1 to 5.0 cm. Final histological diagnosis confirmed 12 typical and one atypical pulmonary carcinoid. Mean proliferation rate of the typical carcinoids was 1.7 +/- 1.4%. None of the patients had recurrent carcinoid disease or died during follow-up (864 +/- 218 days). Mean standardized uptake value (SUV) of (18)F-fluorodeoxyglucose (FDG) in typical carcinoids was 3.0 +/- 1.5 (range 1.2 - 6.6); SUV in the atypical carcinoid was remarkably high with a value of 8.5. The SUV was lower than 2.5 in 6 of 12 patients (50%). Mediastinal lymph node metastases or extrathoracic metastases were not detected in any patient.

CONCLUSIONS

(18)F-fluorodeoxyglucose PET/CT imaging improves accurate localization of metabolic activity and thus the interpretation of pulmonary lesions on CT. FDG uptake in pulmonary carcinoid tumours is often lower than expected for malignant tumours. Therefore, surgical resection or biopsy of lesions suspected to be carcinoids should be mandatory, even if they show no hypermetabolism on FDG PET images.

Labeling of adult stem cells for in vivo-application in the human heart

Tissue regeneration with human hematopoietic or mesenchymal stem cells has become a fashionable research topic. In cardiology, intracoronary injection of adult stem cells has already been used for the treatment of human myocardial infarction and ischemic cardiomyopathy. The experimental background of such therapies, however, i.e. the potential of adult stem cells to regenerate myocardium through "transdifferentiation" of hematopoietic or mesenchymal stem cells into cardiomyocytes described in animal models, has recently been challenged by other experimental data. Nonetheless, clinical trials are continuing. This may be due to the fact that, in open-labeled pilot trials, a benefit of intracoronary injection of adult stem cells for the treatment of myocardial infarction has been described. As pilot trials may overemphasize the beneficial effects of intracoronary injection of bone marrow stem cells, controlled double-blinded randomised multicenter studies are warranted. Furthermore, a careful characterization of the cells involved in the proposed cardiac repair as well as in vivo-monitoring of such cells following intracoronary injection in humans might help to answer many essential questions linked to this important research topic. The latter requires biocompatible labeling. This review focuses on the technologies available for stem cell labeling and summarizes the arguments and contra-arguments to use these labeling technologies for application in humans.

A new strategy for easy volume conductor modelling in magnetocardiography

Modelling the electromagnetic properties of the thorax in magnetocardiographic (MCG) studies is usually performed by the Boundary Element Method (BEM). Magnetic Resonance Imaging (MRI) scans are generally used as the basis for extracting the coordinates for BEM. As MRI is a (time) expensive technique and scanners have a high use demand, in this work a strategy is presented that reduces the costs and the need for additional MRI images. This strategy is based on the use of low resolution and incomplete MRI image sets of the thorax.

Assessment of left ventricular function with steady-state-free-precession magnetic resonance imaging. Reference values and a comparison to left ventriculography

Ejection fraction (EF) and end-diastolic and end-systolic volume index (EDVI/ ESVI) derived from ventriculography are important prognostic parameters. Cine magnetic resonance imaging (MRI) using a steady-state, free-precession sequence (SSFP) offers excellent delineation of the endocardial borders and highly reproducible and accurate results for cardiac volumes. We evaluated MRI volumetry against routine x-ray ventriculography. In 200 patients EF, EDVI and ESVI were measured with MRI volumetry and x-ray ventriculography. The same MRI protocol was applied to 102 healthy persons in order to establish reference values. In healthy subjects mean EF was 68.8% +/- 5.4% (range 59-84%), mean EDVI 69 +/- 10 (43-90) and mean ESVI 22 +/- 5.8 (10-35 ml). In the patients, overall correlation (Spearman's R) of MRI with ventriculography was 0.86 for EF, 0.77 for EDVI and 0.88 for ESVI. For postextrasystolic beats (38% of the measurements), R was 0.73/0.65/0.73 for EF/EDVI/ESVI. MRI correlated best with biplane ventriculography during sinus rhythm (0.96/0.85/0.93); the worst correlation (0.78/0.81/0.83) resulted from patients with wall motion abnormalities in comparison to monoplane x-ray ventriculography.

CONCLUSION

Contemporary MRI volumetry compares well to invasive data obtained under optimal conditions. In view of the known limitations of single plane ventriculography, MRI seems to allow exact volumetry independent from regional wall motion abnormalities.

C-reactive protein and atherosclerosis. Is there a causal link?

C-reactive protein (CRP) is a powerful cardiovascular risk marker. Evidence suggests that this may be due to its direct proatherogenic properties. Because of different biological functions of CRP in different species, an appropriate animal model for the study of its role in atherogenesis is difficult to set up. Binding to low density lipoprotein (LDL), activation of the complement system and interaction with monocyte/macrophages are rigorously defined pathogenic properties of CRP which might contribute to an active role of the molecule in human atherogenesis. Furthermore, direct effects on arterial wall cells, i.e. endothelial cells and smooth muscle cells, have been reported. The molecular basis of CRP interaction with these cells, however, remains unclear. Should CRP indeed be actively involved in human atherogenesis, the molecule may become a target for therapy. Pharmaceutical companies develop CRP-inhibitors.

Inhibition of MMP-9 expression by PPARgamma activators in human bronchial epithelial cells

BACKGROUND

The release of matrix degrading enzymes such as matrix metalloproteinase 9 (MMP-9) from bronchial epithelial cells is critically involved in airway wall remodelling in chronic inflammatory processes of the respiratory system. MMP-9 expression is induced by inflammatory mediators such as tumour necrosis factor (TNF)-alpha, but to date nothing is known about the mechanisms of inhibition of MMP-9 expression in these cells.

METHODS

A study was undertaken to examine whether activators of the nuclear transcription factor peroxisome proliferator activated receptor gamma (PPARgamma) might modulate MMP-9 expression in two different bronchial epithelial cell lines.

RESULTS

PPARgamma was expressed and was functionally active in NL20 and BEAS cells. Activation of PPARgamma by rosiglitazone or pioglitazone significantly reduced TNF-alpha and PMA induced MMP-9 gelatinolytic activity in a concentration dependent manner in both cell lines, but did not alter the expression of tissue inhibitor of MMPs type 1 (TIMP-1), the local inhibitor of MMP-9. Northern blot analysis revealed a decrease in MMP-9 mRNA expression following treatment with PPARgamma which resulted from the inhibition of NF-kappaB activation in these cells, as determined by transient transfection assays and electromobility shift assays.

CONCLUSION

Activation of PPARgamma in human bronchial epithelial cells limits the expression of matrix degrading MMP-9. This might have therapeutic applications in chronic inflammatory processes of the respiratory system.

Pulmonary Hemodynamics in Obstructive Sleep Apnea: Frequency and Causes of Pulmonary Hypertension

The association between nocturnal apneas and transient pulmonary hypertension (PHT) has been well documented. However, there is controversy over the frequency and pathophysiological mechanisms of daytime pulmonary hypertension in patients with obstructive sleep apnea (OSAS). The present study sought to evaluate frequency and mechanisms of pulmonary hypertension in patients with OSAS. It included 49 consecutive patients with polysomnographically proven OSAS without pathological lung function testing. All patients performed daytime measurements of pulmonary hemodynamics at rest and during exercise (50-75W). Six patients (12%) had resting PHT mean pulmonary of artery pressure (PAPM) of >20 mmHg), whereas 39 patients (80%) showed PHT during exercise (PAPM >30 mmHg). Multiple regression analysis revealed 3 independent contributing factors for mean pulmonary artery pressure during exercise (PAPMmax): body mass index, age and total lung capacity % of predicted. Twenty-five of the 39 patients with pathologically high PAPMmax (64%) showed elevated pulmonary capillary wedge pressures (PCWPmax > 20 mmHg), whereas no patient had elevated pulmonary vascular resistance (PVRmax > 120 dynes x s x cm(-5)). In conclusion, daytime PHT during exercise is frequently seen in patients with OSAS and normal lung function testing and is mainly caused by abnormally high PCWP, whereas PVR seems to play a minor role.

[Effect of molsidomine on rheological parameters and the incidence of cardiovascular events]

BACKGROUND AND OBJECTIVE

In-vitro studies revealed that nitric oxide (NO) may affect rheological parameters. We studied the effect of highly-dosed NO-donor molsidomine on blood rheology and the impact of rheological parameters on the incidence of severe cardiovascular events.

PATIENTS AND METHODS

In this randomized, placebo-controlled and double-blind trial 166 patients (60 +/- 10 years) with stable angina pectoris and coronary intervention received molsidomine 3 x 8 mg t. i. d. (controlled release tablets) or placebo for 6 months. Patients with inflammatory/neoplastic disorders or elevated values of C-reactive protein were excluded from analysis. A rheological profile (plasma viscosity, blood viscosity, aggregation and flexibility of erythrocytes, filtrability of leukocytes, fibrinogen levels) was done initially and after 6 months. Adverse cardiovascular events (death, myocardial infarction, stroke, coronary/peripheral revascularization) were recorded during 12 months. Furthermore, the impact of rheological parameters regarding the occurrence of severe cardiovascular events (death, myocardial infarction, stroke) was evaluated during a follow-up of median 38 months.

RESULTS

The data of 137 patients (n = 71 placebo, n = 66 molsidomine) were analysed. The difference of rheological parameters between the two measurements did not vary between the two groups. Analysis of event-free survival with Kaplan-Meier technique revealed no difference between the two groups. Multivariate Cox regression analysis with adjustment for diabetes mellitus, smoking and therapy with statin showed a significant association of fibrinogen and plasma viscosity with the occurrence of severe cardiovascular events.

CONCLUSION

Treatment with molsidomine 3 x 8 mg/day for 6 months does not improve blood rheology or reduce cardiovascular events. But elevated levels of fibrinogen and plasma viscosity were associated with the occurrence of severe cardiovascular events.

Temperature changes in chicken embryos exposed to a continuous-wave 1.25 GHz radiofrequency electromagnetic field

A total of 550 fertile chicken eggs (White Leghorn) were exposed to a radiofrequency (RF) electromagnetic field of 1.25 GHz (continuous wave) at six different power flux densities in the range of 9.0-0.75 mW/cm(2). The eggs were exposed either continuously throughout the whole 21 days of incubation (long-term exposure) or in a short-term exposure (1-2 h/day). The temperatures of the embryonic tissue and the amniotic fluid, respectively, were measured with inserted temperature probes. This study was designed to investigate the relationship between exposure and temperature changes in exposed tissues, without considering biological and medical effects. This knowledge is of general interest for studies of nonthermic teratological or embryo-lethal effects of exposure to electromagnetic fields (EMFs). Throughout the entire 21 days of embryonic development, the mean temperature increases in the eggs during the exposure were found to be up to 0.25 degrees C for a power flux density of 1.25 mW/cm(2) and increased to 2.3 degrees C for 9.0 mW/cm(2). The corresponding maximum whole-body SARs for the embryos over the 21 days of embryonic development were 1.45 and 10.44 W/kg, respectively. At 0.75 mW/cm(2) (0.87 W/kg) the extent of the RF-field induced hyperthermia was within the measurement accuracy (+/-0.1 degrees C) of the temperature probes used in the tests. The field-induced temperature increase was greatest in the first week of incubation and was less pronounced in the last (third) week before hatching. In both the short- and the long-term exposures, the temperature of the exposed tissue and the amniotic fluid, respectively, reached its maximum (asymptotic) approximately 40-50 min after the RF field was switched on. After the field was switched off, the temperature inside the exposed eggs returned to its initial value within 40-50 min.

On the variability of QRS time-duration in magnetocardiographic recordings

High resolution electrocardiography (HRECG) recordings have already shown an increased beat-to-beat microvariability of the QRS duration of the terminal QRS in patients with a history of ventricular tachycardia (VT). The purpose of this study is to detect QRS-duration microvariability with magnetocardiographic (MCG) recordings in normals, patients with coronary heart disease (CHD), patients with a history of myocardial infarction (MI), and VT patients. QRS microvariability is calculated as the variance of time-shifts of single beats respectively to the average of all beats. The average over all channels of the MCG is performed. QRS microvariability was evaluated from 55-channel MCG in 15 normal persons, in 12 patients with CHD, in 13 patients with MI, and in 10 patients with VT. We found a significantly higher microvariability in patients with MI compared to normals. The highest microvariability was found in VT patients.

Microvascular permeability is increased in both types of diabetes and correlates differentially with serum levels of insulin-like growth factor I (IGF-I) and vascular endothelial growth factor (VEGF)

Vascular endothelial growth factor (VEGF) and insulin-like growth factor-I (IGF-I) both play a pivotal role in diabetic microangiopathy. This study assessed the relationship between capillary permeability as a marker of endothelial dysfunction and serum VEGF and IGF-I levels in normotensive diabetics. Subjects were 10 Type 1 (6/4, male/female, age: 30 [mean] +/- 5 [SD] years, HbA1c: 7.5 +/- 1.1 %), 13 Type 2 diabetics (9/4, m/f; 63 +/- 7 years, 8.3 +/- 1.8 %), and 24 age- and sex-matched control subjects. We determined nailfold capillary permeability by intravital fluorescence videomicroscopy after intravenous injection of sodium-fluorescein. Serum VEGF, free and total IGF-I, IGF binding protein (IGFBP)-1, IGFBP-3, and insulin levels were measured by specific immunoassays. Capillary permeability was increased in both types of diabetes patients compared to age- and sex-matched controls. In Type 1 diabetics, fluorescence light intensities increased over time, reaching significance 30 minutes after dye injection. Type 2 diabetics already revealed an early onset of elevated fluorescence light intensities after one minute. Capillary permeability showed a significant positive correlation with VEGF levels in Type 1 diabetics, (r = 0.76, p < 0.05; 20 min after dye injection) but with free IGF-I levels in type 2 diabetics (r = 0.65, p < 0.05; 5 min after dye injection). IGFBP-3 correlated negatively with capillary permeability in both diabetes types, whereas IGFBP-1 levels correlated positively in Type 2 patients. In conclusion, capillary permeability is increased in both types of diabetes mellitus. However, VEGF and IGF-I may differentially affect microvascular permeability depending on the diabetes type.

Comparison of the heparin coated vs the uncoated Jostent--no influence on restenosis or clinical outcome

AIMS

Heparin coating of stents is thought to reduce stent thrombosis and restenosis rates. However, clinical data comparing coated and uncoated stents of the same model are lacking. We compared the heparin coated (C) and the uncoated (U) version of the Jostent stent with regard to the clinical and angiographic outcome after 6 months.

METHODS AND RESULTS

Provisional stenting was done in 277 patients and 306 lesions; only 40 were Benestent-II like lesions. Delivery success rate was 98.4%. Both groups (C/U: n=156/150 lesions) were comparable in clinical and procedural data. Post stenting, reference diameter (C/U: 2.68+/-0.56/2.66+/-0.53 mm) and minimal lumen diameter did not differ (C/U: 2.48+/-0.47/2.48+/-0.52 mm). During follow-up the rate of subacute stent thrombosis (C/U: 1.9%/1.3%) and myocardial infarction did not differ. Angiography at the 6-month follow-up (79.4%) revealed no difference in restenosis rate (C/U: 33.1%/30.3%). Risk factors for restenosis were a type B2/C lesion (P<0.02), a stented segment longer than 16 mm (P<0.006) and a stent inflation pressure <14 bar (P<0.0063).

CONCLUSION

Corline heparin coating of the Jostent has no impact on the in-hospital complication rate, stent thrombosis or restenosis. The Jostent design gives a high procedural success rate and satisfying result at 6 months in an everyday patient population undergoing provisional stenting.

Effects of chronic nitrate therapy on left-ventricular volume in patients with heart failure secondary to coronary disease already treated with captopril: a withdrawal study

OBJECTIVE

This randomized, double-blind, placebo-controlled study with treatment lasting 16 weeks and withdrawal lasting 6 weeks tried to determine whether stopping nitrates has an effect on left-ventricular end-systolic volume in patients with heart failure who were chronically treated with captopril and diuretics.

PATIENTS AND METHODS

The study group comprised 29 patients with previous myocardial infarction, symptoms of mild-to-moderate heart failure, ejection fraction below 40%, no exercise-induced angina and no electrocardiographic signs of ischemia. After all patients had been treated with captopril (target dose: 25 mg twice daily), diuretics and the study drug (target dose: 40 mg isosorbide dinitrate twice daily or placebo) for 16 weeks, the study drug was withdrawn. The patients were then maintained on captopril and diuretics at constant doses for a 6-week withdrawal period. Radionuclide ventriculography with right-heart catheterization was performed at rest and during supine bicycle exercise after 16 weeks of double-blind treatment and at the end of the 6-week withdrawal period.

RESULTS

The changes in resting parameters following the withdrawal of the study drug were not different between the groups. At comparable maximum workload (placebo group 68 +/- 15 W, nitrate group 68 +/- 20 W), nitrate withdrawal caused a decrease in ejection fraction (placebo withdrawal: +0.8 +/- 4.0%; nitrate withdrawal: -2.7 +/- 4.3%, p < 0.02) and increases in left-ventricular end-diastolic volume (-9 +/- 35 vs. 23 +/- 48 ml, p < 0.02) and end-systolic volume (-9 +/- 33 vs. +24 +/- 47 ml; p < 0.01).

CONCLUSION

The addition of nitrates to a baseline therapy with captopril and diuretics might reduce exercise-induced left-ventricular dilatation in patients with heart failure from coronary disease.

Leukocyte attack in a 3D human coronary in-vitro model

OBJECTIVE

The importance of peripheral blood leukocytes for the development of early atherosclerosis and restenosis has confronted cardiologists with classical hematologic issues. Three-dimensional human coronary in-vitro units of leukocyte attack (3DLA-units) open the field for exact studies of leukocyte attack and its subsequent effects on human medial coronary smooth muscle cells (HCMSMC).

METHODS

Central part of 3DLA-units are polycarbonate membranes with a pore size of 5 microm that correspond to the internal elastic membrane. Human coronary endothelial cells (HCAEC) were cultured on one side of the membranes, HCMSMC on the other side. Before leukocyte attack expression of adhesion molecules was up-regulated by tumour necrosis factor-alpha (TNF-alpha). Leukocyte attack was mimicked by selective adding of human monocytes (MC), respectively human CD4+-lymphocytes (CD4+-LC) to the HCAEC side of the 3DLA-units. Three-dimensional leukocyte attack units were fixed and stained after a period of 30 min, 1, 2, 3, 4, 6, and 24 h. Cell divisions of HCMSMC were analysed by measuring the uptake of bromodeoxyuridine (BrdU).

RESULTS

Monocytes were able to adhere to the endothelial surface, pass through the filter-pores, and penetrate the HCMSMC side of the 3DLA-units. Human CD4+-lymphocytes (CD4+-LC) only attached to the HCAEC side, and no chemotaxis to the HCMSMC side was detected. Proliferation of HCMSMC was increased 2.9-fold (P< 0.001) after selective MC-attack and 3.5-fold after selective MC-attack and TNF-alpha stimulus. No significant increase was found after selective CD4+-LC attack, a significant increase (2.1-fold; P < 0.001) was seen after selective CD4+-LC attack and TNF-alpha, stimulus.

CONCLUSIONS

Within the given limitations of the model the study emphasizes a predominance of MC in comparison to CD4+-LC in the process of adhesion, chemotaxis, and triggered reactive proliferation of co-cultured HCMSMC within the first 24 h after leukocyte attack. 3DLA-units offer an elegant method to study directly the effects of intravascular and intramural treatment strategies.

[Peroxisome proliferator-activated receptors (PPARs) in the vessel wall: new regulators of gene expression in vascular cells]

Peroxisome proliferator-activated receptor alpha and gamma (PPAR alpha, PPAR gamma) are nuclear transcription factors regulating gene expression in response to their ligands. Initially, PPARs were identified as regulators of gene expression in lipid metabolism and adipogenesis, but recent work has demonstrated PPAR expression in vascular cells and suggests antiinflammatory properties in the vasculature. Since PPAR alpha activators include lipid-lowering fibric acid derivatives and since PPAR gamma can be activated by antidiabetic thiazolidinediones, activation of these receptors might be an intriguing tool to influence atherogenesis in patients with vascular disease. However, there is also evidence that PPAR activators might furnish lesion development under certain circumstances. The following review will focus on these aspects of potential anti- or proatherogenic effects in the vessel wall and discuss potential clinical implications of these findings.

Aspirin (5 mmol/L) inhibits leukocyte attack and triggered reactive cell proliferation in a 3D human coronary in vitro model

BACKGROUND

Leukocyte attack (LA) and the triggered reactive proliferation of smooth muscle cells (SMCs) are key events for the development of early atherosclerosis and restenosis. In the present study, we used a 3D human coronary in vitro model of LA (3DLA model) to examine the effect of high-dose aspirin on the adhesion and chemotaxis of leukocytes and the reactive proliferative response of SMCs.

METHODS AND RESULTS

For dose-finding, the effect of aspirin (1, 2, 5, and 10 mmol/L) on the tumor necrosis factor-alpha-induced upregulation of intercellular adhesion molecule-1 was analyzed in monocultures of human coronary endothelial cells (HCAEC) and the SMCs of the human coronary media (HCMSMC). In cytoflow and Northern blot experiments, the expression of intercellular adhesion molecule-1 was slightly reduced after incubation with 5 mmol/L aspirin, and strong inhibition was found after incubation with 10 mmol/L. In 3DLA models, HCAECs and HCMSMCs were cultured on both sides of a porous filter. For LA, human monocytes or CD4(+) lymphocytes were seeded on the HCAEC side of the 3DLA unit. A dose of 5 mmol/L aspirin inhibited the adherence of monocytes or CD4(+) lymphocytes by 50% (P:<0.01) and the chemotaxis of monocytes by 90% (P:<0.01). The reactive proliferative response of cocultured HCMSMCs after LA, as measured by the uptake of bromodeoxyuridine, was significantly reduced by 83% after selective monocyte attack (P:<0.001) and by 42% after selective CD4(+) lymphocyte attack (P:<0.05).

CONCLUSIONS

A local concentration of 5 mmol/L aspirin should be accepted as the lowest rational concentration for the beneficial in vitro effects of high-dose aspirin to be reproduced in clinical studies.

C-reactive protein-mediated low density lipoprotein uptake by macrophages: implications for atherosclerosis

BACKGROUND

LDL and C-reactive protein (CRP) are important cardiovascular risk factors. Both LDL and CRP deposit in the arterial wall during atherogenesis. Stranded LDL is taken up by macrophages, causing foam cell formation. Because native LDL does not induce foam cell formation, we hypothesized that CRP may opsonize native LDL for macrophages.

METHODS AND RESULTS

Monocytes were isolated from human blood and transformed into macrophages. CRP/LDL uptake was assessed by immunofluorescent labeling and the use of confocal laser scanning microscopy. Native LDL coincubated with CRP was taken up by macrophages by macropinocytosis. Uptake of the CRP/LDL coincubate was mediated by the CRP receptor CD32.

CONCLUSIONS

We conclude that foam cell formation in human atherogenesis may be caused in part by uptake of CRP-opsonized native LDL.

Current infection with Helicobacter pylori, but not seropositivity to Chlamydia pneumoniae or cytomegalovirus, is associated with an atherogenic, modified lipid profile

Infectious agents may be involved in atherothrombogenesis. The potential pathogenic pathway, however, remains unclear. We investigated the association between various infectious agents and lipoproteins known to have an atherogenic effect. We recruited 470 healthy blood donors and 238 patients with angiographically proven coronary heart disease (CHD), aged 40 to 68 years. Seropositivity to Chlamydia pneumoniae (CP), chlamydial lipopolysaccharide, and cytomegalovirus (CMV) was determined; infection with Helicobacter pylori (HP) was assessed by using the [(13)C]urea breath test. In all subjects, total cholesterol, high density lipoprotein (HDL) cholesterol, lipoprotein(a), and various apolipoproteins (apos) were determined. In unadjusted analysis, mean HDL cholesterol concentration was significantly decreased in HP-positive healthy subjects (1.36 vs 1.44 mmol/L, P=0.006) compared with HP-negative subjects. The HDL cholesterol to total cholesterol ratio was significantly decreased in HP-positive (0.259 vs 0.276, P=0.01) and CP-seropositive (0.266 vs 0.280, P=0.04) healthy subjects compared with (sero)negatives. Mean apoAI levels were significantly lower in HP-positive healthy subjects (1.46 vs 1.51 g/L, P=0.03) and in CMV-positive healthy subjects (1.47 vs 1.52 g/L, P=0.01) compared with (sero)negative subjects. After multivariable adjustment by means of linear regression analysis, only the association between HP infection and decreased HDL cholesterol (P=0.002), decreased HDL cholesterol to total cholesterol ratio (P:=0.005), decreased apoAI (P=0.02), and increased apoB (P=0.02) persisted and remained significant. There was no independent association between other lipoproteins and serological markers of CP or CMV infection. Current infection with HP, but not seropositivity to CP or CMV, was associated with an atherogenic, modified lipid profile. These lipid alterations could explain, at least in part, the reported weak association between chronic HP infection and atherosclerotic diseases.

Role of novel markers of inflammation in patients with stable coronary heart disease

The role of novel markers of inflammation in patients with coronary heart disease (CHD) is still unclear. We conducted a case-control study to assess the association between various markers of inflammation and the presence and severity of chronic stable CHD. We included 312 clinically stable patients with angiographically documented CHD, aged 40 to 68 years. Voluntary blood donors (n = 479) matched for age and gender served as controls. High-sensitivity C-reactive protein, serum amyloid A, plasminogen activator inhibitor-1 activity, von Willebrand factor, fibrinogen, plasma viscosity, albumin, and neutrophils were determined. The severity of CHD was evaluated by 3 coronary scoring systems: the clinical 1- to 3-vessel disease score, the American Heart Association extension score (1 to 15 segments), and the Gensini score. All markers of inflammation were highly significantly elevated (all p <0.005) in patients with stable CHD compared with controls. After multivariable adjustment by means of logistic regression analysis, the association between CHD and fibrinogen, plasma viscosity, von Willebrand factor, and plasminogen activator inhibitor-1 activity remained substantial, whereas it decreased in high-sensitivity C-reactive protein, serum amyloid A, and neutrophils. The combination of > or = 2 markers of inflammation was associated with a strongly increased risk of CHD. No association between markers of inflammation and any of the coronary scores applied was found. These results document an independent association between most of the markers of inflammation and chronic CHD, even in clinically stable patients. The combination of several of these biochemical markers, i.e., the determination of an "inflammatory risk profile," may be useful to further stratify cardiovascular risk.

Angioscopic predictors of restenosis following coronary angioplasty--the impact of yellow smooth plaques

Despite angioscopy being used for more than 10 years, data regarding the prognostic significance are still limited. This study evaluated the prognostic relevance of the angioscopic lesion morphology and plaque colour on restenosis rate following coronary angioplasty. Out of 66 patients with coronary angioscopy prior to an angioplasty procedure, 46 patients with successful balloon dilation and 16 patients with stenting were included into the study. Angioscopic plaque morphology and plaque colour were correlated with the anginal status, the angiographic lesion morphology, the procedural result, and the restenosis rate during six months follow-up. Clinical follow-up was obtained from all patients, re-angiography was performed in 61%. Angioscopically complicated lesions were more frequent in patients with unstable versus stable angina (63% versus 28%, p < 0.005) and ACC/AHA type B2/C versus A/B1 stenoses (86% versus 7%, p < 0.03). In addition yellow plaques were more often seen in unstable versus stable angina (80% versus 50%, p < 0.02) and in type B2/C versus A/B1 lesions (81% versus 47%, p < 0.005). There were no deaths or myocardial infarctions during follow-up. Restenosis (n = 11) occurred significantly more frequent in patients with smooth, yellow lesions (37%) compared to all other lesion morphologies (9%, p < 0.02). Logistic regression analysis revealed angioscopically smooth, yellow plaques (p < 0.05) and angiographically type B2/C lesions (p < 0.03) as independent predictors for restenosis. We conclude that angioscopically smooth, yellow plaques covered by an intact inner vessel surface are associated with a higher incidence of restenosis following coronary angioplasty, potentially indicating a higher proliferative response after a mechanical trauma of such lesions.

PPARalpha activators inhibit tissue factor expression and activity in human monocytes

BACKGROUND

Tissue factor (TF), expressed on the surface of monocytes and macrophages in human atherosclerotic lesions, acts as the major procoagulant initiating thrombus formation in acute coronary syndromes. Peroxisome proliferator-activated receptor-alpha (PPARalpha), a nuclear receptor family member, regulates gene expression in response to certain fatty acids and fibric acid derivatives. Given that some of these substances reduce TF activity in patients, we tested whether PPARalpha activators limit TF responses in human monocytic cells.

METHODS AND RESULTS

Pretreatment of freshly isolated human monocytes or monocyte-derived macrophages with PPARalpha activators WY14643 and eicosatetraynoic acid (ETYA) led to reduced lipopolysaccharide (LPS)-induced TF activity in a concentration-dependent manner (maximal reduction to 43+/-8% with 250 micromol/L WY14643 [P:<0.05, n=5] and to 42+/-12% with 30 micromol/L ETYA [P:>0.05, n=3]). Two different PPARgamma activators (15-deoxy(_Delta12,14)-prostaglandin J(2) and BRL49653) lacked similar effects. WY14643 also decreased tumor necrosis factor-alpha protein expression in supernatants of LPS-stimulated human monocytes. Pretreatment of monocytes with WY14643 inhibited LPS-induced TF protein and mRNA expression without altering mRNA half-life. Transient transfection assays of a human TF promoter construct in THP-1 cells revealed WY14643 inhibition of LPS-induced promoter activity, which appeared to be mediated through the inhibition of nuclear factor-kappaB but not to be due to reduced nuclear factor-kappaB binding.

CONCLUSIONS

PPARalpha activators can reduce TF expression and activity in human monocytes/macrophages and thus potentially reduce the thrombogenicity of atherosclerotic lesions. These data provide new insight into how PPARalpha-activating fibric acid derivatives and certain fatty acids might influence atherothrombosis in patients with vascular disease.