Reduced neural baroreflex sensitivity is related to enhanced endothelial function in patients with end-stage liver disease.

Objectives: Reduced baroreflex sensitivity (BRS) is a frequent complication in end-stage liver disease, but the underlying mechanism is unknown. We investigated the mechanical and neural components of BRS. Increased nitric oxide (NO) production has been reported in end-stage liver failure.

Impaired baroreflex function is related to reduced carotid artery elasticity in patients with tetralogy of Fallot.

Sudden cardiac death (SCD) is a common late complication in patients with tetralogy of Fallot (ToF). Reduced baroreflex sensitivity (BRS) is an independent predictor of SCD and BRS reduction was reported in ToF. Relationship between BRS and carotid artery distensibility (DC) in healthy subjects was reported by us earlier.

Genetic impact dominates over environmental effects in development of carotid artery stiffness: a twin study.

Arterial stiffness is an independent predictor of cardiovascular, cerebrovascular and all-cause mortality. Quantifying the genetic influence on the stiff arterial phenotype allows us to better predict the development of arterial stiffness. In this study, we aimed to determine the heritability of carotid artery stiffness in healthy twins.

Relationship between heart rate variability and endothelial function in healthy subjects.

In various diseased states reduced cardiac vagal activity is accompanied by impaired endothelial function. Evidence from animal studies indicates interaction between the two systems, but such data from human studies is limited. The aim of this study was to test the hypothesis that cardiac vagal activity and endothelial function are related in healthy individuals.

Reversible autonomic dysfunction during antiviral treatment in patients with chronic hepatitis C virus infection: Anti-HCV therapy and autonomic function.

Background: The first clinical sign of chronic hepatitis C virus (HCV) infection can be one of the various extrahepatic manifestations. During antiviral treatment, symptoms of HCV-associated neuropathies usually improve, but can also worsen and lead to discontinuation of anti-HCV therapy. Recently, we have reported autonomic dysfunction in patients with HCV infection.

Carotid artery stiffness is not related to endothelial function in young healthy subjects.

Introduction: Carotid artery stiffness, an important determinant of arterial baroreflex sensitivity, varies considerably in healthy individuals, the source of which variability is not known. Tonic relaxant influence of the endothelium on vascular smooth muscle, reducing stiffness of the vessel wall, has been established in muscular conduit arteries. It is not known to what extent stiffness of the elastic carotid artery is under endothelial control.

Impaired carotid artery elastic function in patients with tetralogy of Fallot.

Complex congenital heart diseases with abnormal formation of the aorticopulmonary septum are also associated with defective large artery elastogenesis. In the current study, we tested the hypothesis that carotid artery elastic function was impaired in patients with tetralogy of Fallot (ToF). The study included 45 Fallot-patients (male:female 27:18; age 21.

Evolution and predictors of morphological and functional arterial changes in the course of type 1 diabetes mellitus.

Background: Diabetes mellitus results in accelerated atherosclerosis. We evaluated preclinical, morphological and functional vascular changes in type 1 diabetes mellitus.

Methods: Diameter, intima-media thickness, intima-media cross-section area, and elasticity features (compliance, distensibility coefficient, circumferential strain, stiffness index, incremental elastic modulus) of the common carotid arteries and carotid-femoral pulse wave velocity were studied in 42 patients with type 1 diabetes mellitus without macroangiopathy, and 41 control subjects matched for sex, age and body mass index using an ultrasonographic vessel wall-movement tracking system and applanation tonometry.

Biomechanics of resistance artery wall remodeling in angiotensin-II hypertension and subsequent recovery.

Background/aims: To identify the relationship between systemic and local hemodynamics, as well as segmental biomechanical properties in a musculocutaneous resistance artery during angiotensin-II hypertension and its recovery.

Methods: Rats were infused with angiotensin-II using implanted osmotic minipumps (ALZET 2ML4, 150 ng/kg/min) for 4 weeks. Measurements were made either immediately following infusion or after an additional 4-week recovery period.

Chronic hepatitis C virus infection associated with autonomic dysfunction.

Background: Impaired autonomic function has been described in patients with chronic liver diseases from different aetiologies, and has proven to be a poor prognostic indicator. To date, it is not known how chronic hepatitis C virus (HCV) infection affects the autonomic nervous system.

Aims: In the present study, we compared cardiovagal autonomic function in patients with chronic HCV infection and healthy controls and examined the relation between autonomic function and serum levels of aminotransferases, HCV RNA, cryoglobulins, albumin and glucose.

Use of generalized transfer function-derived central blood pressure for the calculation of baroreflex gain.

Background: Peripheral blood pressure measurement underestimates pressure changes during baroreflex testing, resulting in an overestimation of baroreflex gain. This error might be reduced by measuring central blood pressure; the invasive measurement, however, may represent ethical and practical problems. The solution may be the derivation of central blood pressure from the peripheral pulse using a generalized transfer function.

Decreased cardiovagal regulation in exfoliation syndrome.

Purpose: To investigate the parasympathetic cardiovascular regulation, baroreflex sensitivity (BRS), and pulse wave velocity (PWV) in exfoliation syndrome (XFS).

Methods: Heart rate variability indices [standard deviation of all RR intervals (SDNN); the mean of absolute successive differences (RMSSD); the percentage of intervals differing by >50 ms from the preceding interval (pNN50); low frequency power, and high frequency power], as well as BRS and PWV, were determined on 27 consecutive white XFS patients and 20 white control subjects under standard circumstances, with controlled breath rate of 0.25 Hz.

[The pH of the exhaled breath condensate: new method for investigation of inflammatory airway diseases].

Collecting exhaled breath condensate (EBC) has become a frequently used method in respiratory researches to date. Through this method we can sample airway surface liquid non-invasively by streaming the exhaled breath through a cooled chamber and after we examine the fluid deposited on the wall of the condenser. The sample contains several mediators, biomarkers.

Adaptation of baroreflex function to increased carotid artery stiffening in patients with transposition of great arteries.

We have shown previously that TGA (transposition of great arteries) is associated with increased carotid artery stiffness. It has been established that stiffening of the barosensory vessel wall results in reduced baroreceptor activation and impaired BRS (baroreflex sensitivity). In the present study we tested the hypothesis that the increased carotid artery stiffness in TGA patients was associated with reduced cardiovagal BRS.

Human heart mitochondria do not produce physiologically relevant quantities of nitric oxide.

Previous studies raised the possibility that nitric oxide synthase is present in heart mitochondria (mtNOS) and the existence of such an enzyme became generally accepted. However, original experimental evidence is rather scarce and positive identification of the enzyme is lacking. We aimed to detect an NOS protein in human and mouse heart mitochondria and to measure the level of NO released from the organelles.

Transposition of great arteries is associated with increased carotid artery stiffness.

Transposition of great arteries is the consequence of abnormal aorticopulmonary septation. Animal embryonic data indicate that septation and elastogenesis are related events, but human and clinical data are not available. We tested the hypothesis that large artery elastic function was impaired in patients with transposition of great arteries.

Mitochondria produce reactive nitrogen species via an arginine-independent pathway.

We measured the contribution of mitochondrial nitric oxide synthase (mtNOS) and respiratory chain enzymes to reactive nitrogen species (RNS) production. Diaminofluorescein (DAF) was applied for the assessment of RNS production in isolated mouse brain, heart and liver mitochondria and also in a cultured neuroblastoma cell line by confocal microscopy and flow cytometry. Mitochondria produced RNS, which was inhibited by catalysts of peroxynitrite decomposition but not by nitric oxide (NO) synthase inhibitors.

Graft derived cells with double nuclei in the penumbral region of experimental brain trauma.

Recent in vitro studies showed that stem cells might fuse with mature cells or each other; however, there is no in vivo evidence for this phenomenon in the cerebral cortex. Our goal was to find evidence for cell fusion in a model of traumatic brain injury followed by grafting of embryonic cortical cells. Cold lesion protocol was applied to induce lesion of the motor cortex in adult male rats.

[Investigation of cerebral autoregulation in Parkinson's disease--a transcranial Doppler study].

Background And Purpose: The frequent orthostatic intolerance in Parkinson's disease could be the consequence of cardiovascular autonomic failure and/or a damaged cerebral autoregulation (AR). To clarify this question the regulation of cerebral circulation was investigated by polygraphic method.

Methods: On a tilt table simultaneous and continuous registrations were made of MCA velocity (V(MCA)) by transcranial Doppler, arterial blood pressure by non-invasive method, and end-tidal CO2, in supine and in tilted positions of 10 degrees, 30 degrees, 70 degrees grades.

Gender differences in the endotoxin-induced inflammatory and vascular responses: potential role of poly(ADP-ribose) polymerase activation.

Activation of poly(ADP-ribose) polymerase (PARP) is an important factor in the pathogenesis of various cardiovascular and inflammatory diseases. Here, we report that the gender-specific inflammatory response is preferentially down-regulated by PARP in male animals. Female mice produce less tumor necrosis factor-alpha and macrophage inflammatory protein-1alpha in response to systemic inflammation induced by endotoxin than male mice and are resistant to endotoxin-induced mortality.

The novel red-fluorescent probe DAR-4M measures reactive nitrogen species rather than NO.

Introduction: Several fluorescent probes were designed for the measurement of nitric oxide (NO), however, questions arose regarding their specificity and sensitivity in biological samples. In the present study we tested the reaction of a novel rhodamine-based chromophore diaminorhodamine-4M (DAR-4M) with NO and other reactive nitrogen and oxygen species.

Methods: We performed fluorometry in 96-well plates in a cell-free buffer with similar ion concentrations as the cytoplasm.

Mitochondrial NO and reactive nitrogen species production: does mtNOS exist?

It is more than 10 years now that mitochondria are suspected to be sources of nitric oxide (NO). This hypothesis is intriguing since NO has multiple targets within the organelle and it is even suggested that mitochondria are the primary targets of NO in the cell. Most remarkably, nanomolar concentrations of NO can inhibit mitochondrial respiration, so even a small amount of NO in the mitochondrial matrix may regulate ATP synthesis.

Reduced baroreceptor sensitivity and elasticity of the carotid artery in a preeclamptic patient.

Baroreflex sensitivity, distensibility coefficient, and intima-media thickness (IMT) of the common carotid artery were determined in a preeclamptic patient during 1st and 3rd trimesters as well as after childbirth. From the beginning of her pregnancy, baroreflex sensitivity and distensibility coefficient of the carotid artery exhibited a parallel decline, whereas the IMT increased as compared with normotensive pregnancies. The values of all parameters examined returned to their initial levels after 14 weeks of delivery.

Cardiovagal autonomic function in sedentary and trained offspring of hypertensive parents.

In young normotensive subjects, parental hypertension is associated with stiffening of the carotid artery and reduction in cardiovagal outflow and baroreflex gain. In subjects without parental hypertension regular exercise training was found to attenuate age-related reduction in carotid compliance and baroreflex gain. The aim of the present study was to test the hypothesis that regular physical activity is associated with better parameters of carotid artery elasticity, increased cardiovagal outflow and higher baroreflex gain in normotensive offspring of hypertensive parents.

Experimental orthostasis elicits sustained hypertension, which can be prevented by sympathetic blockade in the rat.

Incidence of orthostatic hypertension is estimated at 5% but is even more prevalent in borderline hypertension and autonomic neuropathies. The aim of this study was to develop a potential model to investigate orthostatic hypertension. We used normotensive and hypertensive Wistar rats to analyze responses and diurnal variations of arterial blood pressure, heart rate, temperature, and locomotor activity by telemetry.