Abdominal aortic aneurysm screening program in Poland

BACKGROUND

Screening for abdominal aortic aneurysms (AAA) is currently recommended by several vascular societies. In countries where it has been introduced the prevalence of AAAs differed greatly and was mainly related to cigarette smoking. The screening program also had an enormous impact on the decrease of AAA ruptures and reduced mortality rate. These facts have led to the introduction of the first screening program for AAAs in Poland.

OBJECTIVE

The aim of the study was to determine the prevalence of AAAs among men aged 60 years and older undergoing ultrasound examination of the abdominal aorta.

MATERIAL AND METHODS

A single ultrasonography of the abdomen was performed to assess the aorta from the renal arteries to the bifurcation and the diameter of the aorta was measured at its widest point. The cut-off value for determining an aortic aneurysm was set at a diameter of ≥ 30 mm. All ultrasonography measurements were performed by physicians in outpatient departments throughout the Kuyavian-Pomeranian Province. Additionally, each subject had to fill out a questionnaire with demographic data, smoking habits, existing comorbidities and familial occurrence of AAAs. The study was conducted from October 2009 to November 2011.

RESULTS

The abdominal aorta ultrasound examinations were carried out in 1556 men aged 60 years and older. The prevalence of AAA in the study population was 6.0 % (94 out of 1556). The average age of the men was 69 years (SD 6 years, range 60-92 years). In the study population 55 % of the men smoked or had smoked and 3 % were aware of the presence of AAAs in family members. There were three risk factors significantly associated with the presence of AAAs: age (p < 0.05), smoking (72.3 % vs 53.9 %, p = 0.004) and family history of AAAs (9.6 % vs 2.7 %, p = 0.017).

CONCLUSION

The prevalence of AAAs among men in Poland is higher than in other European countries and the USA. The screening program for AAAs is an easy and reliable method for detecting early stages of the disease and risk factors which are the driving forces for the development of AAAs.

Venous symptoms in C0 and C1 patients: UIP consensus document

This UIP document provides an update on venous symptoms in CO and C1 patients. The correlation between venous symptoms and the presence of telangiectases and/or reticular veins is one of the most controversial topics in chronic venous disorders. As symptoms may be non-specific of chronic venous disease, it is important to differentiate venous symptoms from symptoms of other causes. Some data from the Bonn Vein Study suggest that the risk to develop venous symptoms is increased in women, advanced age and obesity. Treatment is based on physical advice, elastic compression, venoactive drugs, sclerotherapy, correction of foot static disorders and reduction of body weight. Future research should be promoted on venous symptoms in epidemiological and follow-up studies, about the relationship between female hormone levels and symptomatic telangiectasias, and between venous pain and foot static disorders in C0s C1s patients.

Does morphology of carotid plaque depend on patient's oxidative stress?

OBJECTIVES

This study explored the relationship between oxidative stress biomarkers and stability of carotid plaque. We decided to analyze the broad range of parameters describing oxidative stress in patients with carotid stenosis.

DESIGN AND METHODS

124 consecutive patients undergoing carotid endarterectomy were enrolled in the study group. The control group consisted of 49 patients without symptoms of atherosclerosis. The stability of carotid plaques was assessed using GSM (gray-scale median) scoring system and the study group was divided into three subgroups according to echogenicity of the plaque. The following parameters of oxidative stress/DNA damage were analyzed: i) urinary excretion of the products of oxidative DNA damage repair; ii) the background level of 8-oxo-7,8-dihydro-2'-deoxyguanosine in leukocytes' DNA and in atherosclerotic plaques; and iii) the concentrations of antioxidant vitamins, uric acid and C-reactive protein in plasma.

RESULTS

Oxidative stress (described by redox status) was higher in the patient group than in the control group. There is a correlation between oxidative stress of the patients and stability of the plaque, echolucent plaques (GSM<25) being associated with the highest antioxidant level and lowest excretion of DNA repair markers.

CONCLUSIONS

The plaque formation/morphology may depend on local environment and is independent of oxidative stress/inflammation observed on the level of the whole body.

Aberrant repair of etheno-DNA adducts in leukocytes and colon tissue of colon cancer patients

To assess the role of lipid peroxidation-induced DNA damage and repair in colon carcinogenesis, the excision rates and levels of 1,N(6)-etheno-2'-deoxyadenosine (epsilondA), 3,N(4)-etheno-2'-deoxycytidine (epsilondC), and 1,N(2)-etheno-2'-deoxyguanosine (1,N(2)-epsilondG) were analyzed in polymorphic blood leukocytes (PBL) and resected colon tissues of 54 colorectal carcinoma (CRC) patients and PBL of 56 healthy individuals. In PBL the excision rates of 1,N(6)-ethenoadenine (epsilonAde) and 3,N(4)-ethenocytosine (epsilonCyt), measured by the nicking of oligodeoxynucleotide duplexes with single lesions, and unexpectedly also the levels of epsilondA and 1,N(2)-epsilondG, measured by LC/MS/MS, were lower in CRC patients than in controls. In contrast the mRNA levels of repair enzymes, alkylpurine- and thymine-DNA glycosylases and abasic site endonuclease (APE1), were higher in PBL of CRC patients than in those of controls, as measured by QPCR. In the target colon tissues epsilonAde and epsilonCyt excision rates were higher, whereas the epsilondA and epsilondC levels in DNA, measured by (32)P-postlabeling, were lower in tumor than in adjacent colon tissue, although a higher mRNA level was observed only for APE1. This suggests that during the onset of carcinogenesis, etheno adduct repair in the colon seems to be under a complex transcriptional and posttranscriptional control, whereby deregulation may act as a driving force for malignancy.

Results of the randomized, placebo-controlled clopidogrel and acetylsalicylic acid in bypass surgery for peripheral arterial disease (CASPAR) trial

OBJECTIVE

Dual antiplatelet therapy with clopidogrel plus acetylsalicylic acid (ASA) is superior to ASA alone in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention. We sought to determine whether clopidogrel plus ASA conferred benefit on limb outcomes over ASA alone in patients undergoing below-knee bypass grafting.

METHODS

Patients undergoing unilateral, below-knee bypass graft for atherosclerotic peripheral arterial disease (PAD) were enrolled 2 to 4 days after surgery and were randomly assigned to clopidogrel 75 mg/day plus ASA 75 to 100 mg/day or placebo plus ASA 75 to 100 mg/day for 6 to 24 months. The primary efficacy endpoint was a composite of index-graft occlusion or revascularization, above-ankle amputation of the affected limb, or death. The primary safety endpoint was severe bleeding (Global Utilization of Streptokinase and Tissue plasminogen activator for Occluded coronary arteries [GUSTO] classification).

RESULTS

In the overall population, the primary endpoint occurred in 149 of 425 patients in the clopidogrel group vs 151 of 426 patients in the placebo (plus ASA) group (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.78-1.23). In a prespecified subgroup analysis, the primary endpoint was significantly reduced by clopidogrel in prosthetic graft patients (HR, 0.65; 95% CI, 0.45-0.95; P = .025) but not in venous graft patients (HR, 1.25; 95% CI, 0.94-1.67, not significant [NS]). A significant statistical interaction between treatment effect and graft type was observed (P(interaction) = .008). Although total bleeds were more frequent with clopidogrel, there was no significant difference between the rates of severe bleeding in the clopidogrel and placebo (plus ASA) groups (2.1% vs 1.2%).

CONCLUSION

The combination of clopidogrel plus ASA did not improve limb or systemic outcomes in the overall population of PAD patients requiring below-knee bypass grafting. Subgroup analysis suggests that clopidogrel plus ASA confers benefit in patients receiving prosthetic grafts without significantly increasing major bleeding risk.

Oxidative stress and 8-oxoguanine repair are enhanced in colon adenoma and carcinoma patients

Oxidative stress is involved in the pathogenesis of colon cancer. We wanted to elucidate at which stage of the disease this phenomenon occurs. In the examined groups of patients with colorectal cancer (CRC, n = 89), benign adenoma (AD, n = 77) and healthy volunteers (controls, n = 99), we measured: vitamins A, C and E in blood plasma, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanine (8-oxoGua) in leukocytes and urine, leukocyte 8-oxoGua excision activity, mRNA levels of APE1, OGG1, 8-oxo-7,8-dihydrodeoxyguanosine 5'-triphosphate pyrophosphohydrolase (MTH1) and OGG1 polymorphism. The vitamin levels decreased gradually in AD and CRC patients. 8-OxodG increased in leukocytes and urine of CRC and AD patients. 8-OxoGua was higher only in the urine of CRC patients. 8-OxoGua excision was higher in CRC patients than in controls, in spite of higher frequency of the OGG1 Cys326Cys genotype, encoding a glycosylase with decreased activity. mRNA levels of OGG1 and APE1 increased in CRC and AD patients, which could explain increased 8-oxoGua excision rate in CRC patients. MTH1 mRNA was also higher in CRC patients. The results suggest that oxidative stress occurs in CRC and AD individuals. This is accompanied by increased transcription of DNA repair genes, and increased 8-oxoGua excision rate in CRC patients, which is, however, insufficient to counteract the increased DNA damage.

Nautilus survey on chronic venous diseases

AIM

The large diffusion of venous disease (CVD) has been confirmed by several epidemiological studies in Europe and the USA. Since general practitioners (GPs) are the first segment of the population to evaluate for CVD, the Italian Project Nautilus (concerning vascular prevention) organized a monitoring campaign in 2009 with the aim of studying CVD using the CEAP classification criteria.

METHODS

More than 1000 GPs were included in the survey. The study produced anamnestic and clinical data on more than 10,000 patients with CVD divided into three age segments: </=30 years; 31-60 years; >60 years. Of these results, 83% were considered valid for a statistical evaluation.

RESULTS

The prevalent population in CVD includes adult and aging subjects; four out of five are women. The number of pregnancies is the first risk or predisposing factor in the adult population, and prolonged standing is the first cause in younger subjects. Excess weight and previous thromboses, either superficial (SVT) or deep (DVT), become more significant factors with advancing age and included, respectively, 58% and 44% of the study's subjects over the age of 60. The most severe signs of CVD (edema, venous ulcers) show a significant progression in the aging segment of the population. Edema is present in 50% of the aging population, and inflammatory endothelial activation (swollen, heavy or painful legs) also increases with aging. Symptoms related to hemorrheological activation (including itching, nocturnal cramps) progress in parallel with increasing signs. A history of previous SVT or DVT episodes is the determining factor in more severe signs (CEAP: C4-C6) in more than 50% of the studied patients in comparison with only 20% of patients without a history for SVT or DVT. Diabetes is associated with more severe signs in 50% of patients.

CONCLUSION

The Nautilus Survey of CVD indicates determining factors associated with the beginning and progression of CVD in three different age segments. These factors may be considered as clinically significant parameters for defining the clinical evolution of CVD. The observations are useful to evaluate the best preventive and treatment options on the basis of the most recent pathophysiological considerations.

Initial multi-centre observations upon the effect of a new Topical Negative Pressure device upon patient and clinician experience and the treatment of wounds

Topical Negative Pressure (TNP) has become an accepted intervention in wound healing with a growing body of scientific literature supporting the effectiveness of TNP across a wide variety of wound aetiologies. The range of TNP devices has also increased with perhaps the primary distinction being between those TNP devices that employ gauze or foam as a wound dressing. This study reports preliminary multi-centre observations upon the use of a new gauze based TNP device in the treatment of wounds. Across 3 study centres twenty-nine subjects were recruited to the study with 8 presenting with leg ulcers, 8 with pressure ulcers, 12 with acute or surgical wounds and 1 with a non-healing burn injury. Wounds were then treated with the new TNP therapy for a maximum of 17 days (range 2-17 days). There appeared to be a trend for subjects with leg ulcers to be treated for longer (mean duration 12.9 days) compared to subjects with pressure ulcers (mean duration 6.5 days) or those with surgical wounds (mean duration 8.2 days). Given the relatively short duration of the TNP therapy no wound completely healed although 22/29 (75.9%) showed reductions in surface area per day of treatment with all but 1 pressure ulcer and 1 leg ulcer responding positively to treatment. While not an RCT, this and similar cohort studies may be central to the future selection of TNP devices given the increasing importance of the role of the user interface to reduce the likelihood of incorrect use and sub-optimal outcomes.

The nutritional status of older adults with and without venous ulcers: a comparative, descriptive study

The nutritional requirements of healthy people differ from those who have chronic wounds and while it is generally suggested that the nutritional status of persons with chronic wounds must be addressed, actual data about the nutritional status of older adults with venous ulcers is limited. The nutritional status of hospitalized older adults (n = 40, average age 77 +/- 7.4) with vascular disease was compared to randomly selected outpatients with venous insufficiency ulcers (n = 37, average age 70.4 +/- 8.13) using the Mini Nutritional Assessment instrument. Among all patients assessed, 37 (48%) were at risk for malnutrition or were malnourished. No differences between nutritional status and age or gender were found. The proportion of patients at risk for malnutrition or currently malnourished was significantly higher in the venous ulcer (24 out of 37) than in the control group (13 of 40, chi2 = 15.51, P <0.05). Statistically significant differences were found between the control and venous ulcer group for all anthropometrical assessment variables (BMI, arm circumference, calf circumference, and weight loss in past 3 months), use of more than three prescription drugs, dietary history/assessment (appetite, fluid consumption, independent feeding), and patient self-rated health. The results of this study confirm that a complete patient assessment must include evaluating patient nutritional status and that nutritional disorders are a serious problem among the elderly, especially those with venous ulcers. Additional studies to help optimize the nutritional assessment and management of older adults with venous ulcers are needed.

Tissue Factor, Tissue Factor Pathway Inhibitor and Vascular Endothelial Growth Factor-A in Carotid Atherosclerotic Plaques

OBJECTIVE

To determine the concentration of tissue factor (TF), tissue factor pathway inhibitor (TFPI) and vascular endothelial growth factor A (VEGF-A) in carotid plaques.

MATERIALS AND METHODS

Thirty-eight consecutive patients (20 symptomatic, 18 asymptomatic) undergoing carotid endarterectomy were enrolled into the current study. The concentration of TF, TFPI and VEGF-A in carotid plaque homogenates and blood plasma was measured using enzyme immunoassay.

RESULTS

The concentration of TF in carotid plaque homogenates was 60 fold higher than in blood plasma. There were no statistically significant differences between the concentration of TF, TFPI and VEGF-A in symptomatic and asymptomatic plaques. Carotid plaques of diabetic patients contained an increased level of TF and VEGF-A ( p = 0.002, p = 0.005). The plaque concentration of VEGF-A was elevated among older patients ( p = 0.02). Carotid plaques of non-smokers contained an increased level of TFPI ( p = 0.03). The concentration of TF, TFPI and VEGF-A in carotid plaques correlated positively with plasma level of these factors ( R = 0.86; p < 0.0001; R = 0.91; p < 0.0001; R = 0.80; p = 0.001, respectively). A highly positive correlation between concentration of VEGF-A and TF, TFPI in carotid plaques was also observed ( R = 0.75; p < 0.001; R = 0.62; p < 0.001, respectively).

CONCLUSIONS

TF, TFPI and VEGF-A concentrations do not differ in atheroma removed from symptomatic and asymptomatic patients but are higher in diabetic patients. There is a highly positive correlation between the level of VEGF-A and TF, TFPI in carotid plaques.

Efficacy and safety of the freeze-dried cultured human keratinocyte lysate, LyphoDermtm 0.9%, in the treatment of hard-to-heal venous leg ulcers

LyphoDerm (XCELLentis, Belgium) is an end-sterilized, freeze-dried lysate from cultured allogeneic epidermal keratinocytes, formulated into a hydrophilic gel. Its efficacy and safety were evaluated, in combination with standard care (hydrocolloid dressing and compression therapy), in 194 patients suffering from hard-to-heal (lasting more than 6 weeks and not responding to conventional therapy) venous leg ulcers. Two control groups received standard care, with or without vehicle, respectively. Patients had a median age of 67.5 years and the majority were females (61%). The median duration of the ulcer was 43 weeks and in 39% of the subjects it had been present for more than 1 year. Thirty-eight percent of the patients in the standard care + LyphoDerm group had complete ulcer healing within 24 weeks (primary end point) compared to 27% of patients in the standard care + vehicle pooled groups (P = 0.114) in the "as treated" intent-to-treat cohort (37% vs. 27% in the "as randomized intent-to-treat cohort; p = 0.137). In the subgroup of patients with enlarging ulcers, the difference between the two groups was significant (30% vs. 11%; p = 0.024 in the "as treated" intent-to-treat cohort and 31% vs. 9%; p = 0.005 in the "as randomized" intent-to-treat cohort). LyphoDerm was well tolerated and safe, and no differences in the frequency of adverse events were noted between the treatment groups. Although the primary objective of the study was not achieved, the exploratory analysis carried out in patients with enlarging ulcers suggests that LyphoDerm could offer a new prospect for the treatment of patients with venous ulcers that may prove to be a significant adjunct to the overall provision of care.

Sciatic Nerve Varices

OBJECTIVE(S)

To describe patients presenting with sciatic nerve varices (SNV), presenting pitfalls in diagnosis and management.

DESIGN

Case series.

METHODS

Patients were investigated using duplex ultrasonography pre-operatively in three cases. Treatment was undertaken both by surgery and by foam sclerotherapy.

RESULTS

Clinically, SNV appeared just below the popliteal skin crease, lateral to the small saphenous vein (SSV). In two cases SNV occurred alone, in two further cases SNV occurred in conjunction with varices from other sources. Symptoms of 'sciatic' pain were present in all. Foam sclerotherapy (1% Polidocanol) was undertaken in one case with a varix. Complete obliteration of the vein and resolution of all symptoms was achieved at the 1-month follow-up examination. Surgical management was used in the other cases.

CONCLUSION

The sciatic nerve vein follows the fibular saphenous nerve (lying superficial to the fascia in the leg). This nerve arises from the common peroneal nerve (in the popliteal fossa), and is a major branch of the sciatic nerve. Varices of the associated vein appear to be the result of a dysplasia. This condition may be more common than is currently recognised.

Selected Haemostatic Factors in Carotid Bifurcation Plaques of Patients Undergoing Carotid Endarterectomy

OBJECTIVE

To determine the concentration of selected haemostatic factors (HFs): thrombin-antithrombin complexes (TAT), antithrombin (AT), tissue plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1) and D-dimers in carotid bifurcation plaques and to compare plaque composition in different subgroups of patients (mainly those with symptomatic and asymptomatic carotid stenosis).

MATERIALS AND METHODS

Thirty-eight consecutive patients (20 symptomatic, 18 asymptomatic) undergoing carotid endarterectomy were enrolled in the study. The concentration of selected HFs in carotid plaques was measured using mainly enzyme immunoassay (ELISA). Simultaneously, the concentration of HFs in plasma was also obtained.

RESULTS

Symptomatic plaques contained significantly more TAT complexes (p=0.03). AT was found only in nine out of 38 carotid plaques and was present mainly in symptomatic carotid plaques (n=8/9)(p<0.006). No significant differences were found between symptomatic and asymptomatic carotid plaques with respect to t-PA, PAI-1 and D-dimers concentration. There was an increased concentration of TAT (p<0.001), t-PA (p<0.02) and D-dimers (p<0.02) in carotid plaques of diabetic patients. Patients with coexisting intermittent claudication had elevated levels of D-dimers in carotid plaques (p<0.02). The only positive correlation was demonstrated between the concentration of AT in plasma and carotid plaques (R=0.76; p=0.02).

CONCLUSIONS

All the evaluated HFs are the components of a carotid plaque. Symptomatic patients have increased concentration of TAT complexes in a carotid plaque. The symptomatic carotid plaque contains AT more frequently, which correlates positively with AT plasma levels. The most marked changes in the carotid plaque haemostatic composition (expressed by elevated levels of TAT, t-PA and D-dimers) have diabetic patients.

The influence of environmental factors in chronic venous insufficiency

The present article focuses on the prevalence and risk factors for varicose veins and the severe stage of chronic venous insufficiency (CVI). The evaluation was made by reviewing the results of specific well-designed studies performed on the general population (case-control studies, cross-sectional studies, and large case series). Data from the literature were compared with the results of a recent multicenter cross-sectional study in Poland, in which 40,095 individuals from 803 registers of primary care physicians were clinically examined and assigned a clinical CEAP class. Analysis of the associations between varicose veins or severe CVI prevalence and factors that are usually considered as representing a risk for the development of CVI was performed. In Poland, a prevalence of varicose veins and severe CVI (skin changes, leg ulcer) similar to that observed in the other developed countries was reported. It was more common in women, but female sex was not found to be a strong risk factor. Among the risk factors most closely associated with CVI were age, family history of varicose veins, and constipation, whatever the sex. This is in keeping with findings from recent epidemiologic studies. Obesity and lack of physical activity were strongly associated with CVI in women, more so than in men. The number of pregnancies (more than 2 pregnancies) significantly distinguished between women with and without CVI. Regarding these latter risk factors, the Polish results do not contradict the commonly held beliefs that are found in the literature. A modest association was found with female sex, previous injury in legs (DVT), and remaining in the standing position for a long time, although these parameters are usually among those mostly agreed as being risk factors. The role of the prolonged sitting position was not established. The Polish epidemiologic survey provided updated figures on the prevalence of and risk factors for varicose veins and severe CVI, using clear and globally accepted clinical definitions for the venous disease based on the CEAP classification.

Lymphocyte labile iron pool, plasma iron, transferrin saturation and ferritin levels in colon cancer patients

Patients with colorectal carcinoma showed statistically significant lower values of transferrin saturation, total iron binding capacity and serum iron level as compared with control group, while the level of ferritin and the size of labile iron pool in carcinoma patients were higher, although this difference was not statistically significant. Our observations are in favour of the hypothesis which suggests that changes in iron metabolism restrict iron availability for tumour cells and as consequence, slow their growth.

Persistent oxidative stress in colorectal carcinoma patients

We examine whether the level of 8-oxo-2'-deoxyguanosine (8-oxodGuo) in lymphocytes DNA is higher in colon cancer when compared to the control group. Factors that may influence oxidative stress such as antioxidant vitamins and uric acid were also determined. Blood samples were obtained from a control group of 55 healthy persons and 43 colon cancers. 8-OxodGuo level and the vitamins concentration were measured by high-performance liquid chromatography. The levels of 8-oxodGuo were significantly higher whereas the concentrations of the vitamins and uric acid were significantly lower in colon cancer patients than in control group. Therefore, the decreased concentration of antioxidant vitamins together with lower amount of uric acid may be responsible for the formation of pro-oxidative environment in blood of colorectal carcinoma patients.

The level of 8-oxo-7,8-dihydro-2'-deoxyguanosine is positively correlated with the size of the labile iron pool in human lymphocytes

It appears that the labile iron pool (LIP, low molecular weight iron) presence in cells can result in the production of reactive oxygen species (ROS). ROS may be responsible for the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) in cellular DNA. In the present study we report on the relationship between LIP and the endogenous level of 8-oxodGuo in human lymphocytes. Good correlation has been determined between LIP and the oxidatively modified nucleoside. This in turn points out the possibility that under physiological condition there is the availability of LIP for catalyzing Fenton-type reactions in close proximity to cellular DNA. Electronic supplementary material to this paper can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00775-001-0335-x.

Lymphocyte labile iron pool, plasma iron, transferrin saturation and ferritin levels in colon cancer patients

Patients with colorectal carcinoma showed statistically significant lower values of transferrin saturation, total iron binding capacity and serum iron level as compared with control group, while the level of ferritin and the size of labile iron pool in carcinoma patients were higher, although this difference was not statistically significant. Our observations are in favour of the hypothesis which suggests that changes in iron metabolism restrict iron availability for tumour cells and as consequence, slow their growth.

8-Oxo-7,8-dihydroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine levels in human urine do not depend on diet

In the present study, we used the method involving HPLC pre-purification followed by gas chromatography with isotope dilution mass spectrometric detection for the determination of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and 8-oxo-7,8-dihydroguanine (8-oxoGua) in human urine. The mean levels of 8-oxoGua and 8-oxodGuo in the urine samples of the subjects on unrestricted diet were respectively 1.87 nmol/kg 24 h (+/-0.90) and 0.83 nmol/kg 24 h (+/-0.49), and in the case of the groups studied, they did not depend on the applied diet. The sum of the amounts of both compounds in urine can give information about the formation rate of 8-oxoGua in cellular DNA. It is also likely that the levels of modified nucleo-base/side in urine sample are reflective of the involvement of different repair pathways responsible for the removal of 8-oxodGuo from DNA, namely base excision repair (BER) and nucleotide excision repair (NER).

Further evidence that oxidative stress may be a risk factor responsible for the development of atherosclerosis

There are numerous data suggesting that oxidative stress may be involved in the development of atherosclerosis. Therefore, in the present study we measured the amount of 8-hydroxy-2'-deoxyguanosine (8-OH-dG), one of the typical biomarkers of oxidative stress, in DNA isolated from lymphocytes of the patients and in the control group. Levels of antioxidant vitamins (A, C, and E) and intracellular labile iron pool (LIP), which can influence oxidative stress, were also determined. Blood samples were obtained from a control group of 55 healthy persons and from 43 atherosclerotic patients. 8-OH-dG and the vitamin levels were measured by high-performance liquid chromatography. Labile iron pool in lymphocytes was analyzed by fluorescent assay. The levels of 8-OH-dG and LIP were significantly higher and vitamin C concentration was significantly lower in the patient group than in the control group. The rest of the analyzed parameters do not significantly differ between the groups. A lower concentration of vitamin C and higher levels of labile iron pool in a group of atherosclerotic patients when compared with the control group may lead to oxidative stress, which is manifested by a higher level of 8-OH-dG in blood lymphocytes. All these factors may create an environment that promotes the development of atherosclerosis.

Flow affects development of intimal hyperplasia after arterial injury in rats

This study examined the effects of blood flow on intimal hyperplasia after balloon catheter injury of the rat common carotid artery. Flow was altered by ligation of the opposite common carotid artery (increased flow) or of the ipsilateral internal carotid artery (decreased flow). Blood flow decreased by 35% in the low-flow group and increased by 29% in the high-flow group. Similar changes in mean velocity were observed. Cross-sectional intimal area was significantly greater in the low- than the high-flow group at 2 weeks (0.11 +/- 0.01 versus 0.06 +/- 0.01 mm2, p less than 0.01) and 4 weeks (0.17 +/- 0.02 versus 0.12 +/- 0.01 mm2, p = 0.01) but not at 1 or 8 weeks. Smooth muscle cell proliferation rates (thymidine labeling indexes) were not different in high- and low-flow groups at 2 days and at 1 and 4 weeks. Matrix accumulation at 2 and 4 weeks was the same in both groups. Mature neointima did not respond to changes in flow; when vessel ligation was delayed until 2 months after injury, there was no effect on neointimal area. These data indicate that early neointimal hyperplasia is increased when flow is reduced, possibly because of alteration of smooth muscle cell migration.

Platelet-derived growth factor promotes smooth muscle migration and intimal thickening in a rat model of balloon angioplasty

Platelet-derived growth factor (PDGF) is a mitogen and chemoattractant for vascular smooth muscle cells (SMC) in vitro, but its activities in vivo remain largely undefined. We infused recombinant PDGF-BB (0.01-0.30 mg/kg per d i.v.) into rats subjected to carotid injury. PDGF-BB produced a small increase (two- to threefold) in medial SMC proliferation. More importantly, PDGF-BB greatly increased (20-fold) the intimal thickening and the migration of SMC from the media to the intima during the first 7 d after injury. These data provide support for the hypothesis that PDGF, and perhaps other platelet factors, might play an important role in the movement of mesenchymal cells into zones of injury undergoing repair.