Quality of life in patients with Fabry's disease: a cross-sectional study of 86 adults

Background

Fabry disease (FD) is a multi-organ disorder associated with severe physical and psychological impairments, particularly in adulthood. To date, comprehensive data on the psychological burden of FD are lacking. The present study assessed quality of life (QOL) in a representative cohort of adults with FD.

Methods

Patient-reported outcome measures were retrospectively analyzed in 86 adults with FD (49.6±16.6 years; 62.8% female) and compared to adults with congenital heart defects (ACHD) which is another lifelong disease and affliction. QOL was assessed using the European Quality of Life 5 Dimensions 5 Levels questionnaire (EQ-5D-5L).

Results

Subjects affected by FD reported an overall reduced QOL (EQ-VAS: 71.8±20.0). Most frequently reported complaints occurred within the dimensions pain/discomfort (69.7%), daily activities (48.9%) and anxiety/depression (45.4%). Compared to ACHD, individuals with FD scored significantly lower in the areas of pain/discomfort, usual activities and mobility (all P<0.05). Older age and female sex were particularly associated with diminished QOL (P=0.05).

Conclusions

Patients with FD are at high risk for impaired QOL. They require additional support to cope with disease-related challenges. Increased attention should be directed towards improving their subjective well-being to potentially increase their QOL and long-term health outcomes.

Blood pressure control in the general and high risk populations, longitudinal trends

Introduction

Despite better control of high blood pressure (BP) in the general as well as high cardiovascular (CV) risk populations as a factor contributing to the decrease in CV mortality since 1990, the targets set by the guidelines may not have been reached.

Purpose

We analysed longitudinal trends in BP control in the general and high risk populations, to assess implementation of guidelines and to identify subpopulations with still unsatisfactory BP control.

Methods

Analysis of seven independent surveys of the general population (Czech MONICA and post-MONICA studies, 1985–2017) and five independent surveys of patients with stable manifest coronary heart disease (CHD) 1995–2017 (Czech samples of the EUROASPIRE I-V surveys).

Results

A total of 15 000 persons (Czech MONICA) and 2 098 patients (Czech EUROASPIRE) were investigated. In the 1985–2017 period, mean systolic BP decreased in the general population (MONICA) from 134 to 128 mmHg (p&lt;0.001) and diastolic BP from 84 to 82.5 mmHg (p&lt;0.01), hypertensive levels of BP (&gt;140/90mmHg) were found in 45% in 1995 but only in 27.5% in 2017, and the prevalence of uncontrolled severe hypertension (BP&gt;180/110 mmHg) decreased from 3 to 1%. The proportion of properly controlled hypertension increased from 13.2 to 53% (p&lt;0.0001). In the 1995–2017 surveys of the high-risk population (EUROASPIRE) systolic BP decreased from 144.1 to 135.5 mmHg (p&lt;0.001), diastolic BP from 87.5to 83.5mmHg (p&lt;0.01), higher than recommended BP (&gt;140/90mmHg, &gt;140/85mmHg in diabetics) was found in 66.2% in 1995, still present as much as in 54.4% in 2017. Proportion of patients with very high BP (BP&gt;180/110 mmHg) decreased from 18.4 to 1% only. Drugs with a potentially antihypertensive effect were used in 79.9 and 95.3% of patients in 1995 and 2017, respectively (p&lt;0.0001). Population BP levels ceased to decline since 2000/01 survey, in the CHD population since the 2012/13 survey. This is obviously due to considerable increase in prevalence of obesity, and an increasing prevalence of diabetes, both in the general and high-risk populations. The more intensive medical high BP treatment seems to have a beneficial effect on hypertension control, even more in the general than in the high risk population.

Conclusions

The recent trend in BP levels, both in the general and high-risk populations, are far from satisfactory, with the main causative factor suggested to be the increasing prevalence of obesity and diabetes. While there has been progress in hypertension control, more in the general nad limited in high-risk population, truly effective BP control may be illusory without comprehensive CV risk factor control.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Agency for Medical Research, Ministry of Health of the Czech Republic

Time trends in the relation between the achieved education and the cardiovascular risk factors prevalence and control in general population and in persons with coronary heart disease

Background

Achieved education is the most consistent and powerful socioeconomic status index and the differences in cardiovascular mortality (CV) according to achieved education in the Czech Republic are over a long period among most pronounced in Europe. Higher prevalence of CV risk factors in less educated is the major factor behind their higher CV morbidity and mortality.

Purpose

To analyse the changes in prevalence and control of CV risk factors according to achieved education in general population and in patients with stable CHD and their impact on CV mortality.

Methods

Based on data of 15 590 persons from 7 cross sectional epidemiological surveys carried through the Czech MONICA and post-MONICA project in 1985–2018 in identical 6 districts of the Czech Republic (general population) and on data of 2129 patients from 5 independent descriptive surveys of the Czech EUROASPIRE study in 1995–2018 (patients with stable CHD) time trends of major CV risk factors and their control in respondents with basic, secondary and university education were compared.

Results

The persons from general population as well as patients with CHD with higher education had consistently lower BMI and lower prevalence of obesity, the differences increased in due time (p&lt;0,001), the prevalence of obesity increased in all educational strata (p&lt;0,001). The total and non-HDL cholesterol were higher in lower educational population strata (p&lt;0,01), but not in CHD patients, there was a very pronounced continuous decrease in all educational strata (p&lt;0,001 for trend). Population systolic and diastolic blood pressures and prevalence of hypertension were higher in men and women with basic education (p&lt;0,01) and decreased during the analysed period (p&lt;0,001). In CHD patients the blood pressure was higher only in women. The prevalence of smoking was higher in men with basic education and decreased in all educational strata (p&lt;0,0001), in women the prevalence of smoking increased in women with basic and decreased in women with secondary and university education (p&lt;0,0001), in CHD patients the prevalence of smoking was lower and did not differ according to education. Prevalence of diabetes and of sedentary life style increased and was more prevalent in general as well as in CHD population in persons with lower education.

Conclusion

CV risk gradient in general population and in CHD patients decreased with level of education achieved, was present during the whole analysed period and became more pronounced in the 2016–18 survey. The education based differences were more pronounced in factors influenced by lifestyle (BMI, smoking) and less in factors influenced also by medical therapies (blood pressure, cholesterol levels). The impact on CV mortality is to be expected more pronounced in general CV prevention and less in already treated population. Observation of healthy life style remains a basic problem in CV prevention, particularly in persons with elementary education.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Agency for Medical Research, Ministry of Health of the Czech Republic

P5530The low expression of circulating microRNA-19a represents an additional mortality risk in stable patients with vascular disease

Background

Secondary prevention of atherosclerotic vascular diseases represents a cascade of procedures to reduce the risk of future fatal and non-fatal cardiovascular events. We sought to determine whether the expression of selected microRNAs influenced mortality of stable chronic cardiovascular patients.

Methods

The plasma concentrations of five selected microRNAs (miR-1, miR-19, miR-126, miR-133 and miR-223) were quantified in 826 patients (mean age 65.2 years) with stable vascular disease (6–36 months after acute coronary syndrome, coronary revascularization or first-ever ischemic stroke). All-cause and cardiovascular mortality rates were followed during our prospective study.

Results

Low expression (bottom quartile) of all five miRNAs was associated with a significant increase in five-year all-cause death, even when adjusted for conventional risk factors, treatment, raised troponin I and brain natriuretic protein levels [hazard risk ratios (HRRs) were as follows: miR-1, 1.65 (95% CI: 1.16–2.35); miR-19a, 2.27 (95% CI: 1.59–3.23); miR-126, 1.64 (95% CI: 1.15–2.33); miR-133a, 1.46 (95% CI: 1.01–2.12) and miR-223, 2.05 (95% CI: 1.45–2.91)]. Nearly similar results were found if using five-year cardiovascular mortality as the outcome. However, if entering all five miRNAs (along with other covariates) into a single regression model, only low miR-19a remained a significant mortality predictor; and only in patients with coronary artery disease [3.00 (95% CI: 1.77–5.08)], but not in post-stroke patients [1.63 (95% CI: 0.94–2.86)].

Conclusions

In stable chronic coronary artery disease patients, low miR-19a expression was associated with a substantial increase in mortality risk independently of other conventional cardiovascular risk factors.

Acknowledgement/Funding

Health Development Agency of the Czech Ministry of Health [project 17-29520A], Charles University Research Fund (PROGRES, project Q39)

Desphospho-uncarboxylated matrix Gla protein is associated with increased aortic stiffness in a general population

Matrix Gla protein (MGP), a natural inhibitor of calcification, strongly correlates with the extent of coronary calcification. Vitamin K is the essential cofactor for the activation of MGP. The nonphosphorylated-uncarboxylated isoform of MGP (dp-ucMGP) reflects the status of this vitamin. We investigated whether there is an association between dp-ucMGP and stiffness of elastic and muscular-type large arteries in a random sample from the general population. In a cross-sectional design, we analyzed 1087 subjects from the Czech post-MONICA study. Aortic and femoro-popliteal pulse wave velocities (PWVs) were measured using a Sphygmocor device. Dp-ucMGP concentrations were assessed in freshly frozen samples by enzyme-linked immunosorbent assay methods using the InaKtif MGP iSYS pre-commercial kit developed by IDS and VitaK. Aortic PWV significantly (P<0.0001) increased across the dp-ucMGP quartiles. After adjustment for all potential confounders, aortic PWV independently correlated with dp-ucMGP (with beta coefficient (s.d.) 11.61 (5.38) and P-value=0.031). In a categorized manner, subjects in the top quartile of dp-ucMGP (⩾ 671 pmol l(-1)) had a higher risk of elevated aortic PWV, with corresponding adjusted odds ratio (95% confidence interval) 1.73 (1.17-2.5). In contrast, no relation between dp-ucMGP and femoro-popliteal PWV was found. In conclusion, increased dp-ucMGP, which is a circulating biomarker of vitamin K status and vascular calcification, is independently associated with aortic stiffness, but not with stiffness of distal muscular-type arteries.

[Distribution of lipoprotein associated phospholipase A2 in Czech population and its interaction with conventional cardiovascular risk]

INTRODUCTION

Lipoprotein associated phospholipase A2 (Lp PLA2) represent new cardiovascular risk factor and potential treatment target. We aimed to analyze the epidemiological situation of this factor in Czech population.

METHODS AND RESULTS

The study population consisted from 1 962 subjects, a random samples of general population (postMONICA study), and from patients with manifest coronary or cerebrovascular disease (Czech samples of EUROASPIRE III survey). Lp PLA2 activity was estimated using commercial kits by diaDexus Inc. in frozen samples. Increased activity (by definition, i.e. > 195 nmol/ min/ ml) was observed in 21.1 % of sample, no apparent difference between subject with and without manifest vascular disease was found. Males showed higher Lp PLA2 activity, than females (179.6 vs 146, resp., p < 0.0001), while no substantial increase with age was observed. Taking Lp PLA2 activity > 195 as dependent variable, following independent variables entered the multiple logistic regression: male gender [with odds ratio 4.26 (3.26- 5.58)], low HDL cholesterol (i.e. < 1.0 mmol/ l in males or < 1.2 mmol/ l in females) [3.49 (2.62- 4.64)], LDLcholesterol > 2.5 mmol/ l [6.95 (4.79- 10.07)] and lipid  lowering treatment [0.59 (0.44- 0.79)]. In subject without manifest vascular disease, 6.3 % of them showed co incidence of markedly increased Lp PLA2 activity with high conventional risk (SCORE > 10 %). Expanding this group by intermediate risk subjects (ie. with Lp PLA2 activity 152- 194 and/ or SCORE 5- 9.9 %) leads to increase of this prevalence to 28.9 % of primary prevention subjects.

CONCLUSION

Increased Lp PLA2 activity is in Czech population highly prevalent and with exception of lipid parameters, generally independent from conventional cardiovascular risk. However, up to 29 % of subject in primary prevention amalgamate increased Lp PLA2 activity with high conventional cardiovascular risk.

DEAD-box protein facilitated RNA folding in vivo

In yeast mitochondria the DEAD-box helicase Mss116p is essential for respiratory growth by acting as group I and group II intron splicing factor. Here we provide the first structure-based insights into how Mss116p assists RNA folding in vivo. Employing an in vivo chemical probing technique, we mapped the structure of the ai5γ group II intron in different genetic backgrounds to characterize its intracellular fold. While the intron adopts the native conformation in the wt yeast strain, we found that the intron is able to form most of its secondary structure, but lacks its tertiary fold in the absence of Mss116p. This suggests that ai5γ is largely unfolded in the mss116-knockout strain and requires the protein at an early step of folding. Notably, in this unfolded state misfolded substructures have not been observed. As most of the protein-induced conformational changes are located within domain D1, Mss116p appears to facilitate the formation of this largest domain, which is the scaffold for docking of other intron domains. These findings suggest that Mss116p assists the ordered assembly of the ai5γ intron in vivo.

The interaction of endothelial nitric oxide synthase polymorphism and current smoking in terms of increased arterial stiffness

Nitric oxide belongs to the most important factors influencing structural and functional properties of vessel wall. Both genetic and environmental factors may influence its metabolism. The aim of this study was to explore whether two common polymorphisms of endothelial nitric synthase (eNOS) may, jointly with smoking, influence the stiffness of large arteries, quantified as pulse wave velocity (PWV). One hundred ninety four subjects free of manifest atherosclerotic disease or chronic pharmacotherapy were selected from population-based postMONICA study. PWV´s were measured using Sphygmocor® device between carotic and femoral arteries (aortic PWV) and between femoral and tibialis-posterior arteries (peripheral PWV). Two common polymorphisms, T786C and G894T, were assessed. Among current smokers, homo- or heterozygous carriers of T786C mutation showed significantly higher peripheral PWV than normal genotype carriers (14.0 vs 10.7 m/s, p<0.002); the same was true for the carriers of G894T mutation (13.9 vs 11.0 m/s, p<0.015). No differences were found in non-smokers, and neither of the eNOS polymorphisms influenced aortic PWV in our setting. In conclusion, genetically determined disorder of nitric oxide metabolism was associated with increased stiffness of peripheral, muscular-type arteries in generally healthy, untreated subjects, but only in the interaction with current smoking.

Detection of disseminated tumour cells in mediastinoscopic lymph node biopsies and endobronchial ultrasonography-guided transbronchial needle aspiration in patients with suspected lung cancer

PURPOSE

Ultrasound-guided transbronchial needle aspiration of mediastinal lymph nodes (EBUS-TBNA) is apparently more accurate for cancer diagnosis than standard transbronchial needle aspiration (TBNA), but it is less sensitive than mediastinoscopy. The detection of disseminated tumour cells in transbronchial needle aspiration and mediastinoscopic biopsies could improve staging and might be helpful concerning indications for neoadjuvant regimen. The goal of this study was to develop a quantitative method for the detection of disseminated tumour cells (DTCs) in lymph node samples from patients with suspected lung cancer.

PATIENTS AND METHODS

We compared in a prospective trail EBUS-TBNA (n=58 patients, 86 samples) and mediastinoscopy (n=22 patients, 37 samples) in two largely independent cohorts of lung cancer patients. Eleven patients, 14 samples were analysed using both methods. Patients without evidence of malignant disease were available as controls for EBUS-TBNA (n=20 patients, 28 samples) and mediastinoscopy (n=6 patients, 8 samples). Real-time quantitative mRNA analysis was performed for the cytokeratin 19 (CK19) and MAGE-A genes (MAGE-A 1-6, MAGE-A12) as markers, using a LightCycler 480 instrument.

RESULTS

CK19 mRNA expression in EBUS-TBNA samples was detected in 84/86 (98%) and in 28/28 control samples (100%). After mediastinoscopy 16/37 (43%) samples of lung cancer patients were CK19 mRNA positive while controls showed no CK19 mRNA expression (0/8). MAGE-A expression was detectable in 42/86 (49%) EBUS-TBNA samples and in 13/37 (35%) mediastinoscopy samples. MAGE-A expression was detected in EBUS-TBNA controls in 3/28 (11%) and 1/8 (12%) mediastinoscopy controls. High MAGE-A expression correlated with increased tumour stage.

CONCLUSION

Since CK19 expression was detected in all EBUS-TBNA samples from the control patients, but not in mediastinoscopy samples, we conclude that CK19 is not suitable as a marker for disseminated tumour cells in samples attained by EBUS-TBNA. One possible explanation is a contamination with epithelial cells from the bronchial tubes. MAGE-A genes are promising markers for disseminated tumour cells in lymph nodes in patients with suspected lung cancer which merit further investigation.

Infectious Risk Factors for Atherosclerotic Vascular Disease in Hemodialysis Patients—Chlamydia pneumoniaebut notHelicobacter pylorior Cytomegalovirus is Associated with Increased C‐Reactive Protein

BACKGROUND

Cardiovascular disease is a major problem in patients with chronic renal failure leading to increased mortality. Several infectious agents have been implicated to be associated with atherosclerosis. We were interested to evaluate whether there is a correlation between a past infection with Chlamydia pneumoniae (Cpn), Helicobacter pylori (Hp) or cytomegalovirus (CMV) and the manifestation of a symptomatic atherosclerotic disease in patients with endstage renal failure.

METHODS AND RESULTS

Patients (n=267) on hemodialysis were investigated. In 101 patients with an apparent atherosclerotic disease (case group) increased IgA levels against Cpn were found (p < or = 0.0001 vs. controls; n=33). Nearly 45% of the case group had a history of myocardial infarction (MI) (p < or = 0.0001). Prior stroke was found in about 30% of patients in the case group (p < or = 0.002). Elevated CRP levels were identified as an independent risk factor for atherosclerosis in all groups. IgA seropositivity against Cpn correlated with elevated CRP values for all atherosclerotic patients (p < or = 0.001), especially in the group of patients with MI (p < or = 0.019) and peripheral vascular disease (p < or = 0.005). There was no correlation between CMV (IgG, IgM) or Hp (IgA, IgG) seropositivity and atherosclerotic disease.

CONCLUSION

IgA seropositivity for Cpn and elevated CRP values but not Hp or CMV was associated with an increased rate of symptomatic atherosclerotic manifestations as MI, stroke, cerebral or peripheral atherosclerosis in patients with endstage renal disease on hemodialysis.

Laboratory Evaluation of Antiphospholipid Antibodies in Patients With Venous Thromboembolism

The objective of our study was to evaluate the significance of extended antiphospholipid profile in patients with venous thromboembolism without any systemic autoimmune disease. In 140 patients (age 18-69 years; 47.1% men) with venous thromboembolism and 136 control participants we tested anticardiolipin antibodies, anti-beta 2 glycoprotein I (anti-β2-GPI) and also non-criteria antiphospholipid antibodies: antiphosphatidic acid, antiphosphatidylethanolamine, antiphosphatidylglycerol, antiphosphatidylinositol, antiphosphatidylserine. Commercial and in-house enzyme-linked immunosorbent assays were used. The antibodies with significantly higher prevalence in patients (compared to controls) were: immunoglobulin (Ig) M-anticardiolipin antibodies (12.9%; P = 0.035), IgG-anti-β2-GPI (16.4%; P = 0.0032), IgM-antiphosphatidylethanolamine (14.3%; P = 0.014). In most cases, these three antibodies did not overlap. In conclusion, of non-criteria antiphospholipid antibodies, only antiphosphatidylethanolamine were significantly more prevalent in patients with venous thromboembolism, with only minor overlapping with the criteria antiphospholipid antibodies. Our results suggest the possible utility of searching for antiphosphatidylethanolamine in the clinical suspicion of antiphospholipid syndrome and the absence of criteria antiphospholipid antibodies.

RNA chaperones, RNA annealers and RNA helicases

RNA molecules face difficulties when folding into their native structures. In the cell, proteins can assist RNAs in reaching their functionally active states by binding and stabilizing a specific structure or, in a quite opposite way, by interacting in a non-specific manner. These proteins can either facilitate RNA-RNA interactions in a reaction termed RNA annealing, or they can resolve non-functional inhibitory structures. The latter is defined as "RNA chaperone activity" and is the main topic of this review. Here we define RNA chaperone activity in a stringent way and we review those proteins for which RNA chaperone activity has been clearly demonstrated. These proteins belong to quite diverse families such as hnRNPs, histone-like proteins, ribosomal proteins, cold shock domain proteins and viral nucleocapsid proteins. DExD/H-box containing RNA helicases are discussed as a special family of enzymes that restructure RNA or RNPs in an ATP-dependent manner. We further address the different mechanisms RNA chaperones might use to promote folding including the recently proposed theory of protein disorder as a key element in triggering RNA-protein interactions. Finally, we present a new website for proteins with RNA chaperone activity which compiles all the information on these proteins with the perspective to promote the understanding of their activity.

Asymmetric dimethylarginine and the effect of folate substitution in children with familial hypercholesterolemia and diabetes mellitus type 1

A recently discussed cardiovascular risk factor, asymmetric dimethylarginine (ADMA), is known to act as an endogenous inhibitor of endothelial nitric oxide synthase. The aim of this study was to establish 1) the relationship between ADMA and ultrasonographically or biochemically determined endothelial dysfunction in children, and 2) the effect of folate supplementation on these parameters. The study cohort included 32 children with familial hypercholesterolemia (FH), 30 with diabetes mellitus type 1 (DM1) and 30 age-matched healthy children as the control group. Furthermore, twenty-eight randomly selected FH and DM1 children were re-examined after 3-months supplementation with folic acid. Baseline levels of ADMA and oxidized low density lipoproteins (oxLDL) were significantly higher in FH group than in DM1 and healthy children. Children in DM1 group had significantly lower concentration of homocysteine, but ADMA levels were normal. Folic acid supplementation significantly lowered homocysteine and hsCRP levels in both FH and DM1 group; however, ADMA and oxLDL concentrations remained unaltered. In conclusion, ADMA and oxLDL appear to be associated with endothelial dysfunction in children with FH. Administration of folic acid did not influence these markers in both FH and DM1 children.

Isolation of small RNA-binding proteins from E. coli: evidence for frequent interaction of RNAs with RNA polymerase

Bacterial small RNAs (sRNAs) are non-coding RNAs that regulate gene expression enabling cells to adapt to various growth conditions. Assuming that most RNAs require proteins to exert their activities, we purified and identified sRNA-binding factors via affinity chromatography and mass spectrometry. We consistently obtained RNA polymerase betasubunit, host factor Hfq and ribosomal protein S1 as sRNA-binding proteins in addition to several other factors. Most importantly, we observed that RNA polymerase not only binds several sRNAs but also reacts with them, both cleaving and extending the RNAs at their 3' ends. The fact that the RNA polymerase reacts with sRNAs maps their interaction site to the active centre cleft of the enzyme and shows that it takes RNAs as template to perform RNA-dependent RNA polymerase activity. We further performed genomic SELEX to isolate RNA polymerase-binding RNAs and obtained a large number of E. coli sequences binding with high affinity to this enzyme. In vivo binding of some of the RNAs to the RNA polymerase was confirmed via co-immunoprecipitation in cell extracts prepared from different growth conditions. Our observations show that RNA polymerase is able to bind and react with many different RNAs and we suggest that RNAs are involved in transcriptional regulation more frequently than anticipated.

Synergistic effect of angiotensin II type 1 receptor and endothelial nitric oxide synthase gene polymorphisms on arterial stiffness

Angiotensin II and nitric oxide belong to important factors in the functional and structural changes of vessel wall, leading to its increased stiffness. We investigated, whether common mutations of angiotensin II type 1 receptor (AGTR(1)) and endothelial nitric oxide synthase (eNOS) are associated with increased arterial stiffness. Two polymorphisms, A(1166)C of AGTR(1) and T(786)C of Enos, were estimated in a random, general population-based sample of 250 subjects. Arterial stiffness was measured using Sphygmocor as aortic (carotid-femoral) and peripheral (femoral-tibial) pulse wave velocities (PWV). Carriers of 3-4 mutant alleles from both polymorphisms, that is, homozygous for both mutations or homozygous for one and heterozygous for the second one, showed significantly higher peripheral PWV (17.92+/-2.40) than those with none or only 1-2 mutant alleles (12.37+/-0.51; P<0.003). Carriers of 3-4 mutant alleles had three times higher risk of having increased peripheral PWV (>or= 13.63 m s(-1), that is, in the top quartile) and this association remained significant after adjustment for potential confounders. No association was found between estimated genotypes and aortic PWV. In conclusion, combination of A(1166)C of AGTR(1) and T(786)C of eNOS mutations increased stiffness of muscular-type arteries.

Even mild changes in free thyroxine could influence the degree of heart failure measured by its biological surrogates

Both, severe hypo- or hyperthyroidism may alter hemodynamic parameters. The aim of our study was to ascertain, whether also distinct changes within normal range of free thyroxine (fT4) would be associated with an impairment of left ventricle function in patients with chronic heart failure. Hundred-forty-eight patients (m121, f27, mean age 63.8 +/- 1.14 years) with chronic heart failure, fT4 levels within the normal range (9-22 pmol/l) and without thyrostatics or substitution treatment. Degree of heart failure was quantified by plasma B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP). Patients with fT4 in the range 11.9-14.6 pmol/l [optimal, second-third quintile] had significantly lower NT-proBNP (718 +/- 70.4 pg/ml), than those with fT4 < or = 11.8 [low-normal, bottom quintile](1236 +/- 223.6 pg/ml; p<0.03) and those with fT4 over 14.6 pmol/l [high-normal, top two quintiles] (1192 +/- 114.9 pg/ml; p<0.0002). These differences remain significant, also if adjusted for age, gender and other confounders; adjusted odds ratio was 1.30 (1.05-1.59) for optimal vs. low-normal and 1.27 (1.04-1.55) for optimal vs. high-normal. Similar statistical differences were also found in BNP, but only when optimal and high-normal fT4 ranges were compared. In conclusion, the severity of heart failure seems to be also influenced by only mild deviations of fT4 concentrations from optimal levels.

RNA chaperone activity and RNA-binding properties of the E. coli protein StpA

The E. coli protein StpA has RNA annealing and strand displacement activities and it promotes folding of RNAs by loosening their structures. To understand the mode of action of StpA, we analysed the relationship of its RNA chaperone activity to its RNA-binding properties. For acceleration of annealing of two short RNAs, StpA binds both molecules simultaneously, showing that annealing is promoted by crowding. StpA binds weakly to RNA with a preference for unstructured molecules. Binding of StpA to RNA is strongly dependent on the ionic strength, suggesting that the interactions are mainly electrostatic. A mutant variant of the protein, with a glycine to valine change in the nucleic-acid-binding domain, displays weaker RNA binding but higher RNA chaperone activity. This suggests that the RNA chaperone activity of StpA results from weak and transient interactions rather than from tight binding to RNA. We further discuss the role that structural disorder in proteins may play in chaperoning RNA folding, using bioinformatic sequence analysis tools, and provide evidence for the importance of conformational disorder and local structural preformation of chaperone nucleic-acid-binding sites.

Mild hyperhomocysteinaemia is associated with increased aortic stiffness in general population

Total homocysteine (tHcy) level was identified as a strong and independent predictor of cardiovascular events. We investigated the association between tHcy and mechanical properties of large arteries in a random, general population-based sample of 251 subjects (mean age 48 years). Large artery properties, such as aortic and peripheral (lower-limb) pulse wave velocity (PWV), and augmentation index of radial artery were measured using semi-automatic Sphygmocor device. Aortic PWV (APWV) positively correlated with tHcy (r = 0.28, P<0.0001), and a significant increasing trend of APWV was found by tHcy quartiles (P = 0.0003 by ANOVA). This association remained significant after adjustment for conventional cardiovascular risk factors (age, gender, smoking, overweight, hypertension, dyslipidaemia and impaired glucose metabolism) and for usual homocysteine confounders (folate, B12, renal function). Subjects with mild hyperhomocysteinaemia (i.e. with tHcy > or = 15 micromol/l) had 2.74 times higher risk of having their APWV over 8.42 m/s (i.e. in the top quartile). No such association was found either for PWV measured at lower extremity or for radial augmentation index. In conclusion, in our series of subjects from general population, we found a strong and independent relationship between homocysteine concentration and APWV, a parameter of stiffness of central arteries.

Folate co-administration improves the effectiveness of fenofibrate to decrease the lipoprotein oxidation and endothelial dysfunction surrogates

Fibrate therapy results in elevation of plasma total homocysteine (tHcy), which is known to induce oxidative stress and endothelial dysfunction. We aimed to establish whether fibrate-induced elevation of tHcy has also similar consequences and whether they may be prevented by folate co-administration. Eighteen subjects with hypercholesterolemia were included in an open, prospective, cross-over study. We compared intra-individually the effect of fenofibrate on tHcy, oxidative stress and endothelial dysfunction surrogates, in monotherapy and when combined with 10 mg of folate. These effects were also compared with fluvastatin monotherapy. Fenofibrate in monotherapy significantly decreased LDL cholesterol, increased the tHcy by 39.5 %, while oxidized LDL (oxLDL), malondialdehyde (MDA), von Willebrand factors (vWf) and thrombomodulin (TMD) remained unchanged. When fibrate was co-administered with folate, the tHcy remained on the initial post-diet level, while both the total and oxLDL as well as MDA, vWf and TMD decreased. In contrast to fenofibrate monotherapy, fluvastatin (80 mg) had a similar effect as combined therapy with fenofibrate and folate, while tHcy remained uninfluenced. In conclusion, fenofibrate decreases the LDL cholesterol, but in contrast to fluvastatin, has no significant antioxidative and endothelium-protective potential, probably due to a concomitant increase of tHcy. These effects may be improved by co-administration of folate.

Assays for the RNA chaperone activity of proteins

Proteins with RNA chaperone activity promote RNA folding by loosening the structure of misfolded RNAs or by preventing their formation. How these proteins achieve this activity is still unknown, the mechanism is not understood and it is unclear whether this activity is always based on the same mechanism or whether different RNA chaperones use different mechanisms. To address this question, we compare and discuss in this paper a set of assays that have been used to measure RNA chaperone activity. In some assays, this activity is related to the acceleration of monomolecular reactions such as group I intron cis-splicing or anti-termination of transcription. Hereby, it is proposed that the proteins release the RNAs from folding traps, which represent the kinetic barriers during the folding process and involve the loosening of structural elements. In most assays, however, bimolecular reactions are monitored, which include the simple acceleration of annealing of two complementary RNAs, the turnover stimulation of ribozyme cleavage and group I intron trans-splicing. The acceleration of these reactions most probably involves the unfolding of structures that interfere with annealing or folding and may in addition provoke annealing by crowding. Most assays are performed in vitro, where conditions might differ substantially from intracellular conditions, and two assays have been reported that detect RNA chaperone activity in vivo.