Endothelial function assessment in atherosclerosis: Comparison of brachial artery flow‑mediated vasodilation and peripheral arterial tonometry

INTRODUCTION Endothelial dysfunction, characterized by the loss of nitric oxide bioavailability, is a key element in the pathogenesis of atherosclerosis and an important prognostic factor in cardiovascular diseases. Therefore, the development of reliable, safe, and noninvasive methods of endothelial function assessment is important for their use in cardiovascular risk stratification. Brachial artery flow‑mediated dilation (FMD) is widely used in research but technical difficulties and problems with calibration between laboratories limit its clinical use. Reactive hyperemia–peripheral artery tonometry (RH‑PAT, EndoPAT) has been developed as a simpler, cheaper, and potentially more reproducible method. OBJECTIVES We aimed to investigate associations between RH‑PAT and FMD in relation to atherosclerotic risk factor profile. PATIENTS AND METHODS The study involved 80 subjects (52 men, 28 women) aged 43.6 ±14.8 years, with moderate‑to‑low cardiovascular risk (mean SCORE, 2.2% ±2%), in whom FMD, RH‑PAT, and intima–media thickness (IMT) were determined. RESULTS The reactive hyperemia index (RHI) measured by RH‑PAT correlated with FMD (r = 0.35, P <0.01). However, no significant correlation was observed between RHI and IMT, SCORE, or the number of classical atherosclerotic risk factors (hypertension, smoking, diabetes, hypercholesterolemia), while FMD was significantly correlated with IMT (r = –0.53, P <0.001), risk factors (r = –0.55, P <0.05), and SCORE (r = –0.4, P <0.05). CONCLUSIONS Despite its technical requirements, FMD is a more sensitive method than RH‑PAT in evaluating the effect of classical atherosclerotic risk factors on vascular endothelial function. Microvasculature response during RH‑PAT needs to be further studied, including the assessment of nonendothelial factors that may affect the measurements, before RH‑PAT becomes the universal tool for the evaluation of the endothelial cells

Treatment of denture-related stomatitis improves endothelial function assessed by flow-mediated vascular dilation

Introduction: The presence of oral inflammation has recently been linked with the pathogenesis of cardiovascular diseases. While numerous studies have described links between periodontitis and endothelial dysfunction, little is known about the influence of denture-related stomatitis (DRS) on cardiovascular risk. Therefore, the aim of this study was to determine whether the treatment of DRS can lead to improvement of the clinical measures of vascular dysfunction. Material and methods: The DRS patients were treated with a local oral antifungal agent for 3 weeks. Blood pressure, flow-mediated dilatation (FMD) and nitroglycerine-mediated vascular dilatation (NMD) were measured during three study visits: before treatment, one day and two months after conclusion of antifungal therapy. Results: Flow-mediated dilatation measurements showed significant improvement of endothelial function 2 months after treatment (FMD median 5%, 95 CI: 3–8.3 vs. 11%, 95% CI: 8.8–14.4; p < 0.01), while there was no difference in control, endothelium-independent vasorelaxations (NMD; median = 15.3%, 95% CI: 10.8–19.3 vs. 12.7%, 95% CI: 10.6–15; p = 0.3). Other cardiovascular parameters such as systolic (median = 125 mm Hg; 95% CI: 116–129 vs. 120 mm Hg, 95% CI: 116–126; p = 0.1) as well as diastolic blood pressure and heart rate (median = 65.5 bpm, 95% CI: 56.7–77.7 vs. 71 bpm, 95% CI: 66.7–75; p = 0.5) did not change during or after the treatment. Conclusions: Treatment of DRS is associated with improvement of endothelial function. Since endothelial dysfunction is known to precede the development of severe cardiovascular disorders such as atherosclerosis and hypertension, patients should be more carefully screened for DRS in general dental practice, and immediate DRS treatment should be advised

Denture-related stomatitis is associated with endothelial dysfunction

Oral inflammation, such as periodontitis, can lead to endothelial dysfunction, accelerated atherosclerosis, and vascular dysfunction. The relationship between vascular dysfunction and other common forms of oral infections such as denture-related stomatitis (DRS) is unknown. Similar risk factors predispose to both conditions including smoking, diabetes, age, and obesity. Accordingly, we aimed to investigate endothelial function and major vascular disease risk factors in 44 consecutive patients with dentures with clinical and microbiological features of DRS (n = 20) and without DRS (n = 24). While there was a tendency for higher occurrence of diabetes and smoking, groups did not differ significantly in respect to major vascular disease risk factors. Groups did not differ in main ambulatory blood pressure, total cholesterol, or even CRP. Importantly, flow mediated dilatation (FMD) was significantly lower in DRS than in non-DRS subjects, while nitroglycerin induced vasorelaxation (NMD) or intima-media thickness (IMT) was similar. Interestingly, while triglyceride levels were normal in both groups, they were higher in DRS subjects, although they did not correlate with either FMD or NMD. Conclusions. Denture related stomatitis is associated with endothelial dysfunction in elderly patients with dentures. This is in part related to the fact that diabetes and smoking increase risk of both DRS and cardiovascular disease

Mechanisms of oxidative stress in human aortic aneurysms — association with clinical risk factors for atherosclerosis and disease severity

Aortic abdominal aneurysms (AAA) are important causes of cardiovascular morbidity and mortality. Oxidative stress may link multiple mechanisms of AAA including vascular inflammation and increased metalloproteinase activity. However, the mechanisms of vascular free radical production remain unknown. Accordingly, we aimed to determine sources and molecular regulation of vascular superoxide (O2radical dot−) production in human AAA. Methods and results: AAA segments and matched non-dilated aortic samples were obtained from 40 subjects undergoing AAA repair. MDA levels (determined by HPLC/MS) were greater in plasma of AAA subjects (n = 16) than in risk factor matched controls (n = 16). Similarly, superoxide production, measured by lucigenin chemiluminescence and dihydroethidium fluorescence, was increased in aneurysmatic segments compared to non-dilated aortic specimens. NADPH oxidases and iNOS are the primary sources of O2radical dot− in AAA. Xanthine oxidase, mitochondrial oxidases and cyclooxygenase inhibition had minor or no effect. Protein kinase C inhibition had no effect on superoxide production in AAA. NADPH oxidase subunit mRNA levels for p22phox, nox2 and nox5 were significantly increased in AAAs while nox4 mRNA expression was lower. Superoxide production was higher in subjects with increased AAA repair risk Vanzetto score and was significantly associated with smoking, hypercholesterolemia and presence of CAD in AAA cohort. Basal superoxide production and NADPH oxidase activity were correlated to aneurysm size. Conclusions: Increased expression and activity of NADPH oxidases are important mechanisms underlying oxidative stress in human aortic abdominal aneurysm. Uncoupled iNOS may link oxidative stress to inflammation in AAA. Oxidative stress is related to aneurysm size and major clinical risk factors in AAA patients

Th17 responses are not altered by natural exposure to seasonal allergens in pollen-sensitive patients

Background: Allergic rhinitis affects 10–30 % of the global population and this number is likely to increase in the forthcoming years. Moreover, it commonly co-exists with allergic asthma as a chronic allergic respiratory syndrome. While the involvement of Th2 cells in allergy is well understood, alterations of pro-inflammatory Th17 responses remain poorly characterized. The aim of our study was to determine whether natural seasonal allergen exposure causes changes in T cell subset characteristics in patients with allergic rhinitis and asthma. Methods: Sixteen patients with allergic rhinitis/atopic asthma (9M, 7F; age 31.8 ± 12.1) and 16 healthy controls were recruited into the study (9M, 7F; age 31.2 ± 5.3). Blood samples were collected from the patients 1–3 months before pollen season (visit 1), within 7 days of the appearance of pollen/initiation of allergic symptoms (visit 2) and 2 weeks after visit 2 following the introduction of symptomatic treatment with antihistamines (visit 3). Flow cytometry was used to assess major T cell subsets (naïve, central memory, effector memory and CD45RA+ effector) and key T cell cytokine production (IFNγ, IL-17A, TNF and IL-4) using intracellular staining. Data were analyzed using repeated measures ANOVA and paired t test. Results: As expected, an increase in the percentage of IL‐4+ CD4+ cells was observed during natural pollen exposure in patients with allergic respiratory syndrome. No significant changes were observed in the production of other cytokines, including Th17 cells, which tended to be lower than in the control population but unchanged during pollen exposure. Introduction of antihistamine treatment led to only moderate changes in cytokine production from CD4 and CD8 T cells. Selective changes in CD8+ T cells were observed during natural pollen exposure including a decrease in transient cells (with features of CD45RA+ and CD45RO+ cells) and a decrease in the percentage of central memory cells in the peripheral circulation. Within the CD4 cell group the total percentage of CD45RA positive CD4 cells was increased during pollen exposure. Conclusions: Th1 and Th17 responses are not altered during pollen season but allergen exposure affects T cell activation and memory cell status in patients with allergic respiratory syndrome

Changes in plant species richness in some riparian plant communities as an result of their colonisation by taxa of Reynoutria (Fallopia)

This study deals with the current issue of the synanthropisation of plant cover which manifests itself, amongst other ways, in the spreading of species outside the limits of their natural distribution range. The aim of the studies undertaken for the present report was to estimate the type and scale of threat posed by alien plant species to native plant diversity. The studies were carried out using the example of Reynoutria (Fallopia) species (knotweeds), which are considered to be invasive in our country as well as in other regions of the world. This is an attempt to determine the impact of these plants on the composition and diversity of the natural components of the herb layer in floodplain forest. Investigations were performed on permanent study plots localised in patches of floodplain forest which have been preserved in the valleys of the So≥a, Bia≥a and Jasienica rivers. The results of the field studies have confirmed the hypothesis that Reynoutria species exert a negative influence on the native components of the floodplain forest herb layer. This impact is, however, different with regard to the various life forms and ecological habitat groups of the plants. The increase of surface coverd by knotweeds does not significantly influence the development of early spring geophytes which are able to complete their full life cycle

Changes in plant species richness in some riparian plant communities as an result of their colonisation by taxa of Reynoutria (Fallopia)

This study deals with the current issue of the synanthropisation of plant cover which manifests itself, amongst other ways, in the spreading of species outside the limits of their natural distribution range. The aim of the studies undertaken for the present report was to estimate the type and scale of threat posed by alien plant species to native plant diversity. The studies were carried out using the example of Reynoutria (Fallopia) species (knotweeds), which are considered to be invasive in our country as well as in other regions of the world. This is an attempt to determine the impact of these plants on the composition and diversity of the natural components of the herb layer in floodplain forest. Investigations were performed on permanent study plots localised in patches of floodplain forest which have been preserved in the valleys of the So≥a, Bia≥a and Jasienica rivers. The results of the field studies have confirmed the hypothesis that Reynoutria species exert a negative influence on the native components of the floodplain forest herb layer. This impact is, however, different with regard to the various life forms and ecological habitat groups of the plants. The increase of surface coverd by knotweeds does not significantly influence the development of early spring geophytes which are able to complete their full life cycle

The effect of the treatment of denture related stomatitis on peripheral T cells and monocytes

Purpose: Systemic immune activation has been recently linked to chronic inflammatory disorders of the oral cavity, particularly to periodontitis. The purpose of this study was to determine whether treatment of a fungus-induced oral inflammation, namely denture-related stomatitis (DRS), can affect the activation of the systemic immune response. Materials and Methods: Peripheral blood from patients with denture-related stomatitis caused by Candida albicans infection (n = 15) was collected at three time points: before treatment with nystatin, at the end of therapy and 2 months after finishing therapy. Activation of T cells and monocytes was assessed by flow cytometry. Results: The percentages of peripheral lymphocytes, T cells and their subpopulations, as well as monocytes were similar before, immediately following and two months after nystatin treatment. Cells expressing early activation marker CD69 and RANTES C-C chemokine receptor type 5 significantly increased immediately after treatment and returned to baseline levels after two months. Th17 cells, which have been implicated in the pathogenesis of DRS, remained unchanged. Central memory CD4+ subset and intermediate subset of monocytes were lower after therapy and this effect was sustained for two months. Conclusion: Treatment of denture-related stomatitis does not seem to affect the general state of the cellular components of the immune system. The results suggest a potential proinflammatory effect of the antifungal agent, nystatin. Although transient and not intense, this effect might be of particular clinical importance, because of relationships between inflammation and certain diseases. Further studies are required to clarify this aspect

The Effect of High Silicon and Molybdenum Content on the Mechanical Properties and Microstructure of Gray Cast Iron

This paper presents an overview of the current knowledge concerning SiMo ductile cast iron begins by describing the standard type of ductile cast iron before proceding to description of its microstructures. The paper then presents its chemical composition and the significant influence of individual elements on technological and mechanical properties. The research section focuses the influence of the addition of Si and Mo to the matrix of gray iron. After casting, stepped samples were carried out on the microstructure along with UTS tensile strength tests. The research presented in the article is a preliminary step towards the goal of obtaining a stable production process for silico-molybdenum cast iron