The circulating vascular endothelial growth factor is only marginally associated with an increased risk for atherosclerosis

BACKGROUND

Vascular endothelial growth factor-A (VEGF-A) is a protein that plays a role in the formation and function of blood vessels, promotes increased vascular permeability or migration of monocytes through endothelial layers. We have tested the hypothesis that plasma levels of VEGF-A may be associated with biochemical and radiological parameters as a marker of cardiovascular risk in Caucasian patients with early-onset CAD.

METHODS

The study group included 100 patients: 75 men not older than 50 years and 25 women not older than 55 years at the moment of CAD diagnosis. The control group (patients without CAD) comprised 50 healthy cases. ELISA test was used to measure plasma concentrations of VEGF. Doppler ultrasound of carotid and peripheral arteries was carried out in each patient. Serum glucose, complete lipid profile, ApoA1, ApoB, Lp(a) and blood count were measured in each case.

RESULTS

Only very weak correlations of plasma VEGF levels with biochemical cardiovascular risk factors in the CAD subjects have been demonstrated. In the study group, VEGF concentration was significantly positively correlated with the same blood parameters as white blood cells, platelets, plateletcrit, apolipoprotein B, total and LDL cholesterol fraction. The plaque of common carotid arteries and bifurcation was present in 39% of CAD patients, however, there was no significant association between VEGF plasma concentration and any measured parameters in Doppler ultrasound of carotid and peripheral arteries.

CONCLUSIONS

The circulating VEGF is only marginally associated with an increased risk for atherosclerosis.

Associations between IL-6 and Echo-Parameters in Patients with Early Onset Coronary Artery Disease

BACKGROUND

Over the last two decades, many studies have investigated the association between interleukin 6 (IL-6) and pathogenesis and progression of coronary artery disease (CAD). Patients with CAD manifested at a young age are a particularly interesting group. They differ from older patients, not only in terms of the severity of coronary artery atherosclerosis, but also risk factor profiles, short- and long-term prognosis after myocardial infarction (MI). The role of IL-6 in younger patients with CAD is less well-known. Therefore, our study aimed to analyze the relationship between IL-6 level and other inflammations, atherosclerosis, and cardiac function parameters in early onset CAD patients.

METHODS

The study covered 100 patients with early onset CAD and a group of 50 healthy participants. Plasma levels of IL-6 and basic biochemical parameters, anthropometric, echocardiographic, and arteries Doppler ultrasound measurements were performed.

RESULTS

We did not observe a significant difference in IL-6 concentration in plasma between patients with early onset CAD and a control group, but IL-6 level was negatively correlated with echocardiographic measurements of ascending aorta diameter, left ventricular shortening fraction, and right ventricular end-diastolic diameter in our patients.

CONCLUSIONS

In patients with early onset CAD, plasma IL-6 level is associated with other inflammation parameters and with cardiac function, potentially contributing to right ventricular remodeling and left ventricular systolic dysfunction. This suggests possible prognostic benefits of long-time observation of IL-6 level after the acute coronary syndrome.

Is plasma-soluble CD36 associated with density of atheromatous plaque and ankle-brachial index in early-onset coronary artery disease patients?

BACKGROUND

CD36 is a major macrophage scavenger receptor for oxidised low-density lipoprotein particles. Soluble CD36 (sCD36) is circulating as a ligand-bound complex and may be present in microparticles shed from cells such as platelets, monocytes/macrophages, or adipocytes. Positive association of plasma sCD36 with insulin resistance has been reported, and it has been proposed that sCD36 might represent a marker of macrophage activation and inflammation leading to atherosclerosis. Recently we have identified an association between CD36 polymorphism and low thickness of atheromatous plaque, suggesting its protective effect against atherosclerosis development.

AIM

To obtain insight into the relationship between plasma concentration of sCD36 and radiological parameters of atherosclerosis in patients with early-onset coronary artery disease (CAD).

METHODS

The study group comprised 70 clinically stable patients (18 women and 52 men) with early CAD (aged no more than 50 years for men and 55 years for women). Fasting blood sample was taken for serum glucose, lipid profile, ApoA1, ApoB, Lp(a), and plasma sCD36 protein measurements. Each subject's weight, height, waist and hip circumference, and systolic and diastolic blood pressure were measured, and the body mass index, waist-to-hip ratio, and mean arterial pressure were calculated. Doppler ultrasound examinations of carotid and peripheral arteries were performed in all patients. Thickness of intima-media complex (IMC) of common carotid (CCA) and brachial arteries, as well as density and thickness of atheromatous plaque at CCA bifurcation, were measured with M'Ath programme. Plasma concentrations of CD36 antigen were measured by ELISA. Correlations between quantitative variables and sCD36 plasma concentration were assessed with the Spearman rank correlation coefficient (Rs). Associations between qualitative variables and sCD36 plasma concentration were tested with the Mann-Whitney U test.

RESULTS

We observed no significant correlations between sCD36 concentration and radiological parameters of atherosclerosis. We found only borderline significant negative correlation of sCD36 concentration with thickness of IMC of left brachial artery. We also observed a significantly negative correlation with CCA plaque density, but only in the female subgroup and on the right side. Borderline higher sCD36 plasma concentrations were observed in patients with lower ankle-brachial index value (< 0.9).

CONCLUSIONS

The results of the study show no strong associations and do not prove either detrimental or beneficial influence of sCD36 on radiological parameters of atherosclerosis. Further research is necessary to assess the association of high plasma sCD36 concentrations with the risk of plaque instability in patients with early-onset CAD.

CD36 gene is associated with thickness of atheromatous plaque and ankle-brachial index in patients with early coronary artery disease

BACKGROUND

CD36 is a multifunctional molecule engaged in the removal of oxidised LDL from plasma. It is unclear whether mutation of the CD36 gene protects against, or increases, the risk of hypercholesterolaemia, atherosclerosis and its complications.

AIM

To search for associations between the CD36 gene polymorphisms and radiological markers of atherosclerosis progress in Caucasian patients with coronary artery disease (CAD) diagnosed at a young age.

METHODS

The study group comprised 70 patients with early CAD. Doppler ultrasound of carotid and peripheral arteries was carried out and genomic DNA was isolated from each patient.

RESULTS

We found two single nucleotide substitutions in introns (IVS3-6 T/C - rs3173798 and IVS4-10 G/A - rs3211892) and two synonymous polymorphisms in exon 6 (G573A - rs5956 and A591T). The allele frequencies were: 10.7% for the IVS3-6C, 3.6% for the IVS4-10A, 3.6% for the 573A, and 2.1% for the 591T. The 573A allele of CD36 rs5956 polymorphism is associated with low thickness of atheromatous plaque. The 591T allele is associated with lower ankle-brachial index.

CONCLUSIONS

The 573A allele has a protective effect against atherosclerosis development and the 591T allele is a cardiovascular risk factor. Assessment of their functional implications requires further research.

[64-slice computer tomography for diagnostics of the small bowel: computer tomography enteroclysis]

INTRODUCTION

Radiologic imaging of the small bowel is the method of choice because other methods are of limited availability. Computer tomography (CT) enteroclysis is the leading modern method for diagnostic imaging of the small intestine. It combines the advantages of conventional small bowel infusion with those of abdominal CT and can serve to disclose a wide range of small bowel pathologies.

MATERIAL AND METHODS

101 patients underwent CT enteroclysis at the Department of Diagnostic Imaging and Interventional Radiology, Pomeranian Medical University in Szczecin. The procedure of CT enteroclysis is described starting from patient preparation and infusion technique to the scanning protocols.

RESULTS

The results served to characterize the patients, establish indications and contraindications to CT enteroclysis, and reveal common errors of the method.

CONCLUSIONS

Preliminary findings bring to light the considerable usefulness of CT enteroclysis. Other methods like ultrasound, MRI, conventional enteroclysis, or capsule endoscopy can be complementary in special cases.

[Molecular bases of prion diseases]

Prion diseases are transmissible neurodegenerative conditions that include Creutzfeldt-Jakob disease (CJD) in humans and bovine spongiform encephalopathy and scrapie in animals. The normal cellular prion protein (PrP(c)) is a membrane sialoglycoprotein of unknown function having the unique property of adopting an abnormal tertiary conformation. The pathological conformer (PrP(sc)) would be the agent of transmissible spongiform encephalopathies or prion diseases. Prion propagation involves recruitment of host cellular prion protein, primarily of alpha-helical structure, into a disease-specific isoform rich in beta-sheet structure. The existence of multiple prion strains has been difficult to explain in terms of a protein-only infectious agent, but recent studies suggest that strain specific phenotypes can be encoded by different prion protein conformations and glycosylation patterns. It is an intriguing proposition that the post-translational modifications alone, or in combination with amino acid changes, play dominant roles in the pathogenic transformation of PrP(c) to PrP(sc). Prion diseases are unique in that they comprise sporadic, genetic (autosomal dominant inheritance), and iatrogenically or environmentally acquired forms. Point mutations in the prion protein gene lead to neurodegenerative disease.

[Optimized diagnostic performance of brain magnetic resonance imaging in children with idiopathic growth hormone deficiency]

PURPOSE

The aim of this study was to search for correlations between anatomic changes in the pituitary gland and hormonal disturbances in children with short stature.

MATERIAL AND METHODS

Children with short stature were enrolled when criteria of pituitary growth hormone deficiency were partly or completely met. Magnetic resonance imaging was performed in 87 children and particular attention was given to the pituitary gland. Measurements were compared with pituitary dimensions accepted as normal in the literature. Contrast with GdDTPA was used to visualize the pituitary gland and associated structures (stalk, infundibulum). T1-weighted images in the sagittal and coronal planes were obtained. The results were statistically analyzed with non-parametric tests.

CONCLUSIONS

1. Magnetic resonance imaging is a very sensitive method for detecting changes in the pituitary gland and may well be recommended as a method of choice even though the percentage of changes detected with it is rather small. 2. The use of contrast agent may be abandoned to limit costs when searching for cause of growth deficit in children with idiopathic growth hormone deficiency, save for the following cases: hypoplasia or aplasia of the pituitary gland, transection of the stalk, empty sella syndrome or tumor in the central nervous system. 3. Pituitary volume and height appear to be of greatest diagnostic significance, while width (which varies little) can serve as an auxiliary parameter.

Exchange of unsaturated fatty acids between adipose tissue and atherosclerotic plaque studied with artificial neural networks

The linoleic C18:2 (n-6) and linolenic C18:3 (n-3) are recognized as essential components of the diet. Free radical peroxidation of essential fatty acids (EFAs) present in lipoproteins produces oxidized low-density lipoproteins which play a critical role in the development of atherosclerosis. The accumulation of EFAs in the vascular wall and correlations between their content in the adipose tissue and atherosclerotic plaque have been confirmed. The present study was undertaken to determine the usefulness of a neural network for studying the exchange between tissues of linoleic, alpha-linolenic, and arachidonic acids-three fatty acids with a well-understood metabolism. Atheromatous plaques, adipose tissue, and serum were obtained from 31 patients who underwent surgery due to atherosclerotic stenosis of the abdominal aorta, iliac or femoral arteries. Fatty acids were extracted and separated as methyl esters using gas chromatography. Statistical analysis was done with STATISTICA neural networks package. Several correlations reported previously were corroborated and factors modifying the content of individual EFAs in adipose tissue and atherosclerotic plaque were revealed. Artificial neural networks (ANNs) were used to determine factors modifying the content of linoleic, alpha-linolenic, and arachidonic acids in human atheromatous plaques. The mechanism of exchange of some fatty acids between the adipose tissue, atheromatous plaque, and plasma is discussed. The results provide evidence for an effective mechanism of tissue uptake and turnover of linoleic acid. Reduced plasma levels of this acid are compensated by release from adipose tissue and atheromatous plaque. While alpha-linolenic acid is continuously taken up by the plaque, adipose tissue absorbs this acid to a certain level only. The dynamics of exchange of arachidonic acid between adipose tissue and atheromatous plaque reflects a minor role for adipose tissue in determining plaque content of this acid, suggesting that "de novo" synthesis is the chief source of arachidonic acid in plaques.

[The treatment of acute lower limb ischemia]

In 1988-1997 297 patients were operated on acute limb ischemia. In 131 patients ischemia was caused by arterial embolism, in 144 patients by acute arterial thrombosis, in 20 patients by arterial trauma and in 2 patients acute aortic dissection. Acute limb ischemia causes 12.8% risk of death especially in elderly and when the reason for ischemia is acute occlusion of aortic bifurcation. The majority of patients with acute arterial thrombosis requires arterial reconstruction.

[How does carotid artery stenosis increase?]

In 25 patients with carotid artery stenosis equal or higher than 40% colour doppler examinations were performed 105 times. The aim of this study was estimate the dynamics of progress of carotid artery stenosis. The mean time of observation was 22.5 months. In 11 (44%) patients there was no progress of stenosis, in 6 (24%) a leap progress over 30% of arterial lumen, and in 8 (32%) patients the progress of carotid artery stenosis were gradual and slow. The leap progress of carotid artery stenosis was usually caused by eruption or dissection of atherosclerotic plaque located in carotid bifurcation and this situation poses especially high risk of stroke.