Publications by authors named "Helena Lenasi"

We aimed to elucidate the effects of acute hyperglycaemia, induced by an oral glucose tolerance test (OGTT), on the autonomic nervous system (ANS) and skin microvascular reactivity at the time point of peak plasma glucose concentration (c) in 20 young, healthy participants. We assessed their heart rate variability (HRV) as a measure of the ANS activity and the parameters of post-occlusive reactive hyperaemia (PORH) to estimate skin microvascular reactivity as measured by laser Doppler (LD) fluxmetry. The tests were repeated 30 min after a standard OGTT (75 g glucose dissolved in 250 mL water) and, in a separate control experiment, after drinking the same amount of water.

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Wavelet analysis (WA) provides superior time-frequency decomposition of complex signals than conventional spectral analysis tools. To illustrate its usefulness in assessing transient phenomena, we applied a custom-developed WA algorithm to laser-Doppler (LD) signals of the cutaneous microcirculation measured at glabrous (finger pulp) and nonglabrous (forearm) sites during early recovery after dynamic exercise. This phase, importantly contributing to the establishment of thermal homeostasis after exercise cessation, has not been adequately explored because of its complex, transient form.

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Introduction: Due to altered anatomy of the upper respiratory tract, brachycephalic dogs exhibit increased airway resistance and reduced surface area for evaporative heat loss, predisposing them to respiratory and thermoregulatory problems, a syndrome referred to as Brachycephalic Obstructive Airway Syndrome (BOAS). Compared to non-brachycephalic dogs, brachycephalic breeds are more susceptible to heat-related injuries even at low ambient temperatures and relatively low physical activity levels. Surgical treatment alleviates clinical signs, potentially improving dogs' thermoregulatory ability with BOAS.

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Neonatal apnoea can be treated with caffeine, which affects the central nervous and cardiovascular systems. Heart rate variability (HRV) reflects the activity of the autonomic nervous system (ANS) and might be used as a measure of ANS maturation in newborns. We aimed to establish the effect of caffeine on HRV in newborns and investigated the potential correlation between HRV and postmenstrual age (PMA).

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Laser Doppler flowmetry (LDF) has long been considered a gold standard for non-invasive assessment of skin microvascular function. Due to the laser Doppler (LD) microcirculatory signal's complex biological and physiological context, using spectral analysis is advisable to extract as many of the signal's properties as feasible. Spectral analysis can be performed using either a classical Fourier transform (FT) technique, which has the disadvantage of not being able to localize a signal in time, or wavelet analysis (WA), which provides both the time and frequency localization of the inspected signal.

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Šet, V, and Lenasi, H. Does hyperbaric oxygenation improve athletic performance? J Strength Cond Res 37(2): 482-493, 2023-Hyperbaric oxygen (HBO) has been suggested to affect oxygen availability and performance, and delay the onset of fatigue. Many mechanisms of HBO-induced alterations have been proposed, including modulation of various metabolic pathways, and the antioxidant defense mechanisms.

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As cardio-vascular diseases are the leading cause of death worldwide, establishing measures to improve cardiovascular health is of crucial importance. Exercise plays an essential role in cardiac rehabilitation of patients with coronary artery disease (CAD), in whom an evaluation of the cardiorespiratory fitness (CRF) is necessary. CRF of CAD patients could be assessed using 6-min walk test (6MWT), and the results interpreted by using Enright-Sherill prediction equation which has mainly been designed and evaluated for a healthy population.

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Previous echocardiographic studies were mainly focused on preterm infants and early fetal-to-neonatal transition period, whereas little is known about changes in the parameters of the right ventricular (RV) function after 72 h of life. Our aim was to quantitatively characterize potential changes in RV function by echocardiography in healthy term newborns between the third and the seventh day of life. We conducted a prospective observational study in 35 full-term newborns, in whom we performed echocardiographic examinations on the third and the seventh day of life.

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Microcirculation in vivo has been assessed using non-invasive technologies such as laser Doppler flowmetry (LDF). In contrast to chronic hyperglycemia, known to induce microvascular dysfunction, the effects of short-term elevations in blood glucose on microcirculation are controversial. We aimed to assess the impact of an oral glucose load (OGL) on the cutaneous microcirculation of healthy subjects, quantified by LDF and coupled with wavelet transform (WT) as an interpretation tool.

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Background: Lower heart rate variability (HRV) in a newborn might represent a risk factor for unfavourable outcome, a longer recovery after illness, and a sudden infant death. Our aim was to determine whether the newborn's sleeping position is associated with HRV.

Methods: We performed a prospective clinical study in 46 hospitalized cardiorespiratory stable term newborns.

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We aimed to assess the effects of intermittent hyperbaric oxygenation (HBO2 at 2 bars for 120 minutes a day for four successive days) on acetylcholine-induced vasorelaxation (AChIR) in female Sprague-Dawley (SD) rats (N=80) that were randomized into four groups: healthy controls (CTR); diabetic rats (DM); and control and diabetic rats that underwent hyperbaric oxygenation (CTR+HBO and DM+HBO), respectively. AChIR was measured in vitro in aortic rings, with/without L-NAME, MS-PPOH, HET0016 or indomethacin. mRNA expression of eNOS, iNOS, COX-1, COX-2, thromboxane A synthase 1 (TBXAS1), CYP4A1, CYP4A3 and CYP2J3 was assessed by qPCR.

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Objectives: We aimed to assess whether a 7-day high-salt (HS) diet affects endothelium-dependent and/or endothelium-independent microvascular function in the absence of changes in arterial blood pressure (BP), and to determine whether such microvascular changes are associated with changes in body composition and fluid status in healthy young humans.

Materials And Methods: Fifty-three young healthy individuals (28 women and 25 men) were assigned to a 7-day low-salt diet (<3.5 g salt/day) followed by a 7-day HS diet (∼14 g salt/day).

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Aim: To compare regional tissue oxygenation (rSO2) in the brain, intestine, and kidney between newborns with and without congenital heart defects (CHD).

Methods: This observational case-control study was conducted at the Neonatal Department of Children's Hospital Ljubljana between December 2012 and April 2014. It included 35 newborns with CHD and 30 healthy age- and sex-matched controls.

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Purpose: The effect of acute exhaustive exercise session on skin microvascular reactivity was assessed in professional rowers and sedentary subjects. A potential involvement of altered hemodynamic parameters and/or oxidative stress level in the regulation of skin microvascular blood flow by acute exercise were determined.

Methods: Anthropometric, biochemical, and hemodynamic parameters were measured in 18 young healthy sedentary men and 20 professional rowers who underwent a single acute exercise session.

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We aimed to evaluate hemodynamic parameters in the cutaneous microcirculation during recovery to graded dynamic exercise performed on a cycloergometer by using two distinctive methods: high-frequency ultrasound Doppler flowmetry (UDF) and laser Doppler fluxmetry (LDF). Regarding UDF, the medium linear blood flow velocity (Vam) was estimated, expressed in absolute units (cm/s) whereas blood flow assessed by LDF was registered in arbitrary perfusion units (PU). We compared the corresponding perfusion values obtained by UDF and LDF, respectively, every 20 s during recovery period to physical exercise.

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Diabetes mellitus (DM) is associated with cardiovascular complications. Impairment of glycemic control induces noxious glycations, an increase in oxydative stress and dearangement of various metabolic pathways. DM leads to dysfunction of micro- and macrovessels, connected to metabolic, endothelial and autonomic nervous system.

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Hypothyroidism is associated with impaired vascular function; however, little is known about its impact on microcirculation. We aimed to determine skin microvascular reactivity in hypothyroidism focusing on endothelial function and the sympathetic response. We measured skin laser Doppler (LD) flux (LDF) on the volar forearm and the finger pulp using LD flowmetry in hypothyroid patients (N = 13) and healthy controls (N = 15).

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Increasing prevalence, high morbidity and mortality, and decreased health-related quality of life are hallmarks of peripheral arterial disease. About one-third of peripheral arterial disease patients have intermittent claudication with deleterious effects on everyday activities, such as walking. Exercise training improves peripheral arterial disease symptoms and is recommended as first line therapy for peripheral arterial disease.

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Background And Objective: Urinary incontinence (UI) is a common disorder that affects women of various ages and impacts all aspects of life. Our aim was to evaluate the non-invasive erbium:yttrium-aluminum-garnet (Er:YAG) laser that exploits its thermal effect and has been used in reconstructive and rejuvenation surgery as a potential treatment strategy for stress UI (SUI) and mixed UI (MUI).

Study Design/materials And Methods: We included 175 women (aged 49.

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Background: The impact of hyperthyroidism induced by Graves' disease (GD) on skin microcirculation has not been established. We aimed to assess vascular reactivity in hyperthyroid GD patients before and during treatment.

Methods: Laser Doppler flux (LDF) was measured in 31 newly diagnosed hyperthyroid GD patients with an increased TSH receptor stimulating antibody (TSAb) levels before the methimazole treatment; and again 5.

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The saprophytic fungus Rhizopus nigricans constitutes a serious problem when thriving on gathered crops. The identification of any compounds, especially natural ones, that inhibit fungal growth, may therefore be important. During its life cycle, Rhizopus nigricans encounters many compounds, among them the flavonoids, plant secondary metabolites that are involved in plant defense against pathogenic microorganisms.

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The mammalian steroid hormone progesterone actuates a signalling pathway in the zygomycete Rhizopus nigricans which includes heterotrimeric G proteins. To investigate the possibility that the Gβ subunit of these proteins is involved in the signalling, a cDNA library from R. nigricans exposed to progesterone was prepared and a sequence coding for a Gβ subunit was searched for.

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Regular physical activity leads to increased endothelium-dependent vasodilatation. Postocclusive reactive hyperemia (PRH) is a transient increase of blood flow after the release of an arterial occlusion and has been used as a clinical tool to estimate endothelial function. The aim of our study was to assess the potential effect of regular physical training on PRH of skin microcirculation.

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Mitogen-activated protein kinase (MAPK) cascades and the calcium-calcineurin pathway control fundamental aspects of fungal growth, development and reproduction. Core elements of these signalling pathways are required for virulence in a wide array of fungal pathogens of plants and mammals. In this review, we have used the available genome databases to explore the structural conservation of three MAPK cascades and the calcium-calcineurin pathway in ten different fungal species, including model organisms, plant pathogens and human pathogens.

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