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T. Muka, K. Vargas, L. Jaspers, Ke-xin Wen, K. Dhana, A. Vitezova, J. Nano, Adela Brahimaj et al.

In recent years significant overlap between cardio-metabolic risk factors and cognitive decline has been reported. Cardio-metabolic and vascular factors shown to be associated with Alzheimer’s disease (AD) and other forms of dementia include midlife diabetes and hypertension, cerebrovascular lesions, diminished vascular function, dyslipidemia, obesity, and cigarette smoking. Accordingly, it has been recently proposed that amyloid is not the cause of AD but merely a marker and a later consequence of upstream changes that lead to neuronal and synaptic losses. However, although the idea that features of vascular dysfunction and injury are present in cognitive decline and AD patients was suggested over 25 years ago, the role of cardio-metabolic and cerebrovascular mechanisms in the pathogenesis of AD is far from being fully elucidated. Based on newly proposed vascular hypothesis, there is an impaired structure and function of cerebral blood vessels and cells in patients with cognitive decline and AD which is mediated by vascular oxidative stress. Consistent with these observations, the importance of endothelial dysfunction in the development of AD has been highlighted. One of the most prominent features of endothelial dysfunction is decreased production and bioavailability of Nitric Oxide (NO). Based on versatile properties in physiological as well as in pathophysiological conditions NO is regarded as a key molecule for longevity and cardiovascular health. NO is produced by three different isoforms of the enzyme NO synthase (NOS), namely: endothelial (eNOS), neuronal (nNOS), and inducible (iNOS). Reduced NO bioavailability and altered vascular expression and activity of NOS enzymes are implicated as major molecular players in the process of vascular aging. In the process of aging, the mechanisms by which NOS enzymes promote vascular dysfunction are specific for each NOS isoform. Normal activity of eNOS is required for the balanced production/bioavailability of NO, which is the main prerequisite for optimal vascular function. Conversely, excessive amount of NO produced by iNOS contributes to vascular dysfunction. Furthermore, although the possible role of nNOS-derived NO in aging-associated vascular dysfunction is far from being fully elucidated, experimental findings indicate that impaired perivascular NO release from nNOS increases vasoconstriction in aged arterioles. Oxidative stress and inhibitors of NO synthase are regarded as most potent initiators of disturbed production and bioavailability of NO. Important endogenous inhibitor of all three isoforms of NOS is asymmetrical dimethylarginine (ADMA). It has been recently proposed that ADMA may be a possible link between vascular disease and dementia. Based on this assumption ADMA might represent a unifying pathophysiological pathway linking the presence of vascular risk factors with the onset and progression of cognitive decline and dementia. These observations were made based on good evidence from literature that higher plasma ADMA concentrations favor atherosclerosis and independently predict adverse cardiovascular and cerebrovascular outcomes in several patient groups. However, possible role of ADMA in pathophysiology of cognitive decline and AD is still not fully understood. Prospective studies are warranted aiming at further clarification of ADMA involvement in development and progression of dementia. Moreover, use of ADMA in CSF and /or plasma as prospective biomarker of AD should be explored. According to newly introduced hypothesis disturbed NOS-NO-ADMA pathway is one of the most important attributes of cerebrovascular dysfunction that plays a pathogenic role in the development of cognitive decline and dementia. Experimental data from cell cultures and animal models have demonstrated that dysfunction of the NO-NOS- ADMA pathway results in cell death, blood-brain barrier (BBB) disruption, and brain edema via different pathological mechanisms. However, exact underlining mechanisms through which disturbed NOS-NO-ADMA pathway contributes to cognitive decline and dementia remain to be elucidated. Clarification of these mechanisms may be helpful in the identification of new therapeutic targets for aging and neurodegenerative diseases. Future research should also explain whether endothelial dysfunction precede or follow neurological changes which characterize cognitive decline and dementia. Moreover, clinical and epidemiological studies have shown that healthy nutrition and physical exercise are important non-pharmacological, lifestyle-related interventions that could help in maintaining appropriate vascular tone, adequate cerebral blood flow and normal cognition during aging. It is reasonable to suggest that prevention of cardio-metabolic diseases via endorsement of healthy aging determinants such as control of blood pressure, lipids and glucose levels as well as maintenance of optimal body weight achieved by regular physical activity and nutrition with high anti-oxidant capacity might be effective strategy in the preservation of cognitive function.

Objectives: Aim of the present study was to investigate serum concentration of leptin and its association with values of body mass index (BMI), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) in hemodialysis (HD) patients. Methods: This cross-sectional study included 60 HD patients (34 male, 26 female) and 30 age- and sex-matched (4 males, 26 females) apparently healthy subjects. Serum leptin concentration was determined by an enzyme-linked immunosorbent assay (ELISA). Serum CRP concentration was measured by means of particle-enhanced immunonephelometry. ESR value was determined by Western Green method. BMI was calculated as weight (kg) divided by height squared (m2). Results: Results have shown that median serum leptin concentration (30.65 ng/mL; 12.48-86.40 ng/mL) was statistically significantly higher in HD patients compared to median serum leptin concentration (15.75 ng/mL; 9.15-30.65 ng/mL) in the control group of healthy subjects (p<0.05). Likewise, median serum CRP concentration (5.5 mg/L; 1.93-8.9 mg/L) and median ESR value (57.5 mm/h; 40.5-77.0 mm/h) were significantly higher in HD patients compared to median serum CRP concentration (0.8 mg/L; 0.38-1.43 mg/L) (p<0.001) and median ESR value (10.0 mm/h; 6.5-14.0 mm/h) (p<0.001) determined in the control group. Statistically significant positive correlation was found between BMI values and serum leptin concentration in HD patients (rho=0.434; p<0.001). Positive, although not significant, correlation was observed between serum CRP and leptin levels in HD patients (rho=0.171; p>0.05). Negative correlation between ESR values and serum leptin concentrations in HD patients was determined but it was not statistically significant (rho= -0.029; p>0.05). Conclusions: Increased serum concentration of leptin as pro-inflammatory cytokine as well as elevated serum values of CRP and ESR indicate presence of systemic micro inflammation in HD patients. Results of the present study point to possible use of serum leptin concentration as an indicator of nutritional status in HD patients based on observed significant positive correlation between serum leptin concentrations and BMI values. However, absence of significant association between serum leptin and CRP levels as well as between serum leptin concentrations and ESR values in HD patients requires further investigation and clarification.

The aim of this study was to investigate changes in serum nitric oxide (NO) concentration in inflammatory bowel diseases (IBD) patients and its use as potential biomarker in differential diagnosis of ulcerative colitis (UC) and Crohn's disease (CD) and in disease activity assessment. In 60 patients of both genders - 30 with ulcerative colitis and 30 with Crohn's disease - and 30 controls serum nitric oxide concentration was determined by measuring nitrite concentration, a stable metabolic product of NO with oxygen. Conversion of nitrates (NO3-) to nitrites (NO2-) was done with elementary zinc. The nitrite concentration was determined by classic colorimetrical Griess reaction. Median serum NO concentration was statistically different (p=0,0005) between UC patients (15.25 µmol/L; 13.47 - 19.88 µmol/L), CD patients (14.54 µmol/L; 13.03 -16.32 µmol/L) and healthy controls (13.29 µmol/L; 12.40 - 13.92 µmol/L). When active UC and CD patients were compared with inactive UC and CD patients respectively a significant difference in serum NO level was found (p=0.0005). With a cut-off level of 17.39 µmol/L NO had a sensitivity of 100% and a specificity of 100% in discriminating between active and inactive UC patients. With cut-off value of 14.01 µmol/L serum NO level had a sensitivity of 88% and a specificity of 69% in distinguishing between patients with active CD and inactive CD. Serum NO concentration is a minimally invasive and rapid tool for discriminating between active and inactive IBD patients and could be used as useful biomarker in monitoring of disease activity in IBD patients.

Autoimmune diseases occur in 3−5% of the population. Study included 30 patients with clinically diagnosed SLE and 30 healthy controls (American college of Rheumatology, 1997). SLE was diagnosed according to criteria issued in 1997 by the American College of Rheumatology (ACR). The aim of this study was to evaluate concentration values of each antigen of ENA-6 profile in SLE, to investigate possible correlation between the concentration of Sm antibodies and CIC, and to test their use as possible immunobiological markers in SLE. Furthermore, the aim of our study was to determine whether there is a correlation between Sm antibodies and CIC and SLE activity. The results revealed that all of these ENA-6 and Sm antibodies as biomarkers complement diagnoses of active SLE but their use as solo markers does not allow classifying patients with SLE. Our study has shown that based on calculations from ROC curves, Sm/RNP was clearly a very important marker for diagnosis of SLE (cut off ≥ 9.56 EU, AUC 0,942). The high incidence of Scl-70 (10%) reactivity suggests that ELISA monitoring of this antibody produces more false positive results than other multiplex assay. An important conclusion that can be drawn from the results of our study is that laboratory tests are no more effective than clinical examination for detecting disease relapse, but are helpful in the confirmation of SLE activity.

Cardiovascular diseases (CVD) remain a major burden for public health worldwide. Pivotal concern of primary prevention is identification of individuals that are at risk for developing cardiovascular disease. The use of different algorithms for an assessment of cardiovascular risk allows physicians to identify and treat in a simple and cost-effective manner individuals that may be at high long-term cardiovascular risk.

This study investigated whether serum C-reactive protein (CRP) concentration is increased in patients with type 1 diabetes mellitus with a normal body mass index (BMI) and whether BMI, glycated haemoglobin (HbA1c) and CRP are correlated in patients with type 1 diabetes. High-sensitivity CRP was determined by immunonephelometry and HbA1c by an immunoturbidimetric method in 30 patients with type 1 diabetes and 30 healthy individuals matched for age, sex and BMI. Median serum CRP concentration in patients with type 1 diabetes (1.34 mg/L) was significantly higher than healthy individuals (0.2 mg/L; p<0.0001). Positive correlation between CRP and BMI was observed (rho=0.598; p<0.0001), but no significant correlation was observed between CRP and HbA1c (rho=0.285; p=NS) in patients with type 1 diabetes. Increased CRP levels in type 1 diabetes patients do not appear to be associated with glycaemic control, and may reflect low-grade inflammation associated with atherosclerosis, as well as activation of innate immune activity. Br J Diabetes Vasc Dis 2011;11:249-252

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