Biomedical subjects

Hannes Alber

Publications and source records attributed to Hannes Alber.

8 recordsLinked to original sources

PubMed2006

Atherosclerosis as a risk factor for benign prostatic hyperplasia.

OBJECTIVES: To evaluate the relationship between clinical benign prostatic hyperplasia (BPH) and atherosclerosis, using colour Doppler ultrasonography (CDUS) and symptom scores. PATIENTS, SUBJECTS AND METHODS: CDUS was used to evaluate prostatic vascularity in four groups of men, comprising young healthy subjects, patients presenting with coronary artery disease (CAD), diabetes mellitus, or peripheral arterial occlusive disease (PAOD). Resistive index (RI) measurements and computer-assisted quantification of colour pixel density (CPD) were used to objectively evaluate perfusion. The International Prostate Symptom Score (IPSS) and the International Index of Erectile Function were used to quantify symptoms. RESULTS: In diabetic patients and men with PAOD, perfusion of the transition zone (TZ) of the prostate was significantly lower (P < 0.001) and the RI of the TZ was significantly higher (P < 0.001) than in healthy controls and men with CAD. In diabetics and men with PAOD, the mean prostate volume was greater than in healthy controls and men with CAD. The IPSS in patients with vascular damage (diabetes, PAOD) was significantly worse than in the control group. CONCLUSIONS: The significantly lower CPD and higher RI values of the TZ in patients with vascular disease than in healthy subjects support the hypothesis that an age-related impairment of blood supply to the prostate has a key role in the development of BPH.

Aged↗

PubMed2006

Comparison of three-dimensional imaging to transesophageal echocardiography for preoperative evaluation in mitral valve prolapse.

Transesophageal echocardiography (TEE) is not optimally suited for recognizing which valve segments are involved in type II mitral valve dysfunction. This study was conducted to compare the diagnostic value of TEE and 3-dimensional image reconstruction (3DIR) in the assessment of Carpentier type II mitral valve lesions. In 74 patients (mean age 59+/-13 years) with mitral regurgitation due to type II valve dysfunction, TEE and 3DIR were performed and analyzed by 2 experts before surgical repair. Leaflet scallops and commissures were displayed in short-axis en face and long-axis views. Echocardiographic results were surgically validated. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated, broken down by valve segments and Barlow's disease. Interobserver variability was also determined. Compared with TEE, 3DIR was superior with respect to sensitivity, positive and negative predictive values, and accuracy, although not always significantly (p<0.05). Specificity was higher for P2 lesions. The clearest advantage of 3DIR over TEE was higher sensitivity in commissural and bileaflet defects (p<0.05). Interobserver agreement on 3DIR was stronger than on TEE results (kappa values 0.52 vs 0.82, p<0.0001). There were 16 disagreements (23%) on TEE but only 5 (7%) on 3DIR readings. In conclusion, the more complex the lesion, the more valuable 3DIR is compared with TEE. Before repair, 3DIR is beneficial for the evaluation and classification of the specific pathology in type II mitral valve dysfunction.

Adult↗

PubMed2006

Multislice computed tomography for detection of patients with aortic valve stenosis and quantification of severity.

OBJECTIVES: The purpose of this study was to evaluate whether multislice computed tomography (MSCT) provides a reliable, noninvasive imaging modality for identification of patients with degenerative aortic valve stenosis (AS) by quantifying the aortic valve area (AVA) in comparison to the accepted diagnostic standard transthoracic echocardiography (TTE). BACKGROUND: Management of patients with degenerative AS is based on the severity of disease. The severity of AS in clinical practice is assessed by TTE and classified as mild, moderate, or severe according to the AVA. METHODS: Forty-six patients were examined with contrast-enhanced, electrocardiogram-gated, 16-row MSCT for the evaluation of the diagnostic accuracy. In 30 patients, quantification of the AVA with MSCT was compared to TTE using the continuity equation with Doppler velocity-time integral for calculation of the AVA. RESULTS: Sensitivity of MSCT for the identification of patients with degenerative AS was 100%, and the specificity was 93.7%. Thirty of 46 patients had AS determined by TTE. Quantification of AVA by MSCT (mean AVA = 0.94 cm2) in patients with AS showed a good correlation to TTE (r = 0.89; p < 0.001). Bland-Altman plot illustrated good intermodality agreement between the two methods (limits of agreement, 0.20; 0.29). CONCLUSIONS: Multislice computed tomography may provide an accurate, noninvasive imaging technique for detection of patients with AS and quantification of AVA.

Aged↗

PubMed2006

Valvular heart disease in Parkinson's disease vs. controls: An echocardiographic study.

Restrictive valvulopathy has been reported in association with dopamine agonist therapy in parkinsonian patients. The majority of reports have been related to pergolide, but anecdotal cases following treatment with bromocriptine or cabergoline have also been presented. It is presently unclear whether the potential induction of restrictive cardiac valvulopathy is a class effect of all dopamine agonists or if there is a differential risk between ergot and nonergot compounds. In this study, the frequency of a valvular regurgitation as assessed by routine transthoracic echocardiography was compared between 75 patients with Parkinson's disease (PD) treated with pergolide (n = 29), cabergoline (n = 13), pramipexole or ropinirole (n = 33), and 49 age-matched nonparkinsonian controls. The exposure to pergolide and cabergoline was associated with higher frequencies of valvular regurgitation grades 2 and 3 (31% and 47%) compared with age-matched controls (13%), while there was no increase of valvular regurgitation grades 2 and 3 in patients treated with nonergot compounds (10%). Evidence for restrictive valvulopathy was found in one patient treated with pergolide and cabergoline each. While this study shows similarly increased frequencies of valvular regurgitation in patients treated with the ergot agonists pergolide and cabergoline in comparison to both normal controls and patients treated with nonergot agonists, evidence for restrictive valvulopathy was only found in two cases. These results highlight the need for further prospective studies of the prevalence and underlying mechanisms of cardiac valvulopathy in PD patients treated with different dopamine agonists.

Aged↗

PubMed2005

Effects of local gene transfer of VEGF on neointima formation after balloon injury in hypercholesterolemic rabbits.

Enhancement of the generation of nitric oxide (NO) and vascular endothelial growth factor (VEGF) are suggested to prevent restenosis after angioplasty. Accordingly, we tested whether the local delivery of L-arginine (L-Arg), a substrate for NO generation and the VEGF gene, alone or in combination, can influence neointima formation in hypercholesterolemic rabbits. Balloon injury of the iliac arteries was performed in 24 New Zealand White rabbits fed a 1% cholesterol diet for 3 weeks followed by a local infusion of: (1) pSG5VEGF165 plasmid alone (1000 microg); (2) pSG5VEGF165 (1000 microg) with L-Arg (800mg); (3) L-Arg (800mg) alone; and (4) L-Arg (800 mg) with naked pSVbeta-gal plasmid (1000 microg). The animals were kept on the hypercholesterolemic diets for a further 28 days, when vessels were taken for morphometric analysis and immunocytochemistry. Endogenous rabbit VEGF concentration in the plasma increased significantly at 7 days after injury (17.06 +/- 1.57 vs 23.01 +/- 1.9 pg/ml; p < 0.02) and remained elevated for up to 28 days (28.46 +/- 5.24; p < 0.01). Injured arteries exhibited strong immunocytochemical staining for rabbit VEGF. Rabbits that received a VEGF gene transfer revealed more prominent neointima formation, whereas treatment with L-Arg was associated with significantly less intimal thickness (p < 0.05). Local transfer of the VEGF gene does not inhibit neointima formation in hypercholesterolemic rabbits. Our results suggest that VEGF gene therapy applied locally in atherosclerotic arteries may not be beneficial.

Angioplasty, Balloon↗

PubMed2004

Successful switch from inhalative iloprost to oral bosentan in portopulmonary hypertension associated with liver cirrhosis.

Portopulmonary hypertension (PPHTN) is a rare complication of liver cirrhosis. Prostanoids have been shown to be effective in the treatment of PPHTN and have been used as a bridge to orthotopic liver transplantation. However, inhibition of platelet aggregation might be a limitation of prostacyclin therapy in patients with end-stage liver disease having an increased risk of bleeding from esophageal varices. The effect of oral bosentan, a dual endothelin-receptor antagonist in the reversal of PPHTN, is still unclear. We report a case of PPHTN (mean pulmonary artery pressure [mPAP] of 51 mmHg) that was successfully switched from inhalative iloprost to oral bosentan therapy. Hemodynamic and symptomatic improvements were maintained after a 12-month long-term treatment with inhalative iloprost as well as after single oral bosentan therapy. This is the first reported case of a successful switch from therapy with an inhalative prostacyclin analogue to oral bosentan in a patient suffering from PPHTN. Thus, oral bosentan therapy might be a promising new option for patients suffering from PPHTN.

Administration, Inhalation↗

PubMed2003

Statins differentially regulate vascular endothelial growth factor synthesis in endothelial and vascular smooth muscle cells.

OBJECTIVES: HMG-CoA reductase inhibitors (statins) can modulate the formation of new blood vessels, but the reports on their contribution to angiogenesis are contradictory. Therefore, we investigated whether the effect of statins is dependent either on the concentration of the drug or on the cell type. METHODS AND RESULTS: Under basal conditions human vascular smooth muscle cells (HVSMC) and microvascular endothelial cells (HMEC-1) constitutively generate and release vascular endothelial growth factor (VEGF). In contrast, primary macrovascular endothelial cells (HUVEC) produce minute amounts of VEGF. Different statins (atorvastatin, simvastatin and lovastatin, 1-10 micromol/l) significantly reduced basal and cytokine-, nitric oxide- or lysophosphatidylcholine (LPC)-induced VEGF synthesis in HMEC-1 and HVSMC. Interestingly, at the same concentrations statins upregulated VEGF generation in HUVEC. Furthermore, statins exerted dual, concentration-dependent influence on angiogenic activities of HUVEC as determined by tube formation assay. At low concentrations (0.03-1 micromol/l) the pro-angiogenic activity of statins is prevalent, whereas at higher concentrations statins inhibit angiogenesis, despite increasing VEGF synthesis. CONCLUSION: Our data show that statins exert concentration- and cell type-dependent effects on angiogenic activity of endothelial cells and on VEGF synthesis. The data are of relevance for elucidating the differential activity of statins on angiogenesis in cardiovascular diseases and cancer.

Atorvastatin↗

PubMedDate not supplied

Atorvastatin affects several angiogenic mediators in human endothelial cells.

The pleiotropic effects of statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, have been recently extended to the modulation of angiogenesis. Here, to get more insight into the statins action, the authors have investigated the effect of atorvastatin on the expression of several angiogenic and inflammatory genes in human umbilical endothelial cells (HUVECs). Atorvastatin was proangiogenic at the dose of 10 nM, and antiangiogenic at the concentrations of 1 to 10 micro M. Moreover, these higher concentrations inhibited also the proliferation of HUVECs induced by vascular endothelial growth factor (VEGF). Lower doses of atorvastatin did not influence endothelial cell proliferation. Importantly, atorvastatin at the micromolar concentrations diminished the production of interleukin (IL)-8, a proinflammatory and proangiogenic chemokine, and inhibited the synthesis of urokinase plasminogen activator (uPA), a potent proinflammatory mediator. However, it decreased also the expression of plasminogen activator inhibitor-1 (PAI-1) and thrombospondin-1 (TSP-1), the inhibitors of angiogenesis. Atorvastatin stimulated the expression of angiopoietin (Ang)-2 and moderately enhanced the expression of endothelial nitric oxide synthase (eNOS), whereas heme oxygenase-1 (HO-1) was not significantly affected. In conclusion, the present findings points to other angiogenesis-related effects of atorvastatin, which may be of relevance to the beneficial influence of statins in cardiovascular system.

Atorvastatin↗