The aim of this study was to elucidate the biological functions of the motility regulatory protein CheZ in the probiotic strain Escherichia coli Nissle 1917. A cheZ gene deletion strain Nissle 1917ΔcheZ was constructed using the CRISPR/Cas9 two-plasmid system, and the corresponding complemented strain Nissle 1917ΔcheZ/pBR322-cheZ was established. Combined studies of growth kinetics testing, motility assays, swarming motility assays, and bacterial adherence assays were performed to study the motility regulatory protein CheZ-mediated functions in the prototype Nissle 1917 strain, its isogenic cheZ mutant, and the corresponding complemented strain. The growth rate of the cheZ mutant strain was lower than that of the wild-type strain in the exponential growth phase. The motility of the cheZ mutant strain was significantly lower than that of the wild-type strain. And the adhesion ability of ΔcheZ mutant to the Caco-2 cells was significantly lower than that of the wild-type strain and complemented strain. In conclusion, the results presented in our study suggested that the deletion of the cheZ gene in E. coli Nissle 1917 led to a significant reduction of its swimming ability and a subsequent marked decrease of adhesion to the Caco-2 cells.

• Klíčová slova
• Adherence, CheZ, Growth kinetics, Nissle 1917, Swarming motility,
• MeSH
• Caco-2 buňky MeSH
• delece genu MeSH
• Escherichia coli * genetika   MeSH
• lidé MeSH
• plavání MeSH
• probiotika * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

A heart rate biofeedback system consisting of a JPR 12 minicomputer (12 bit, 4 K), of input devices (an electronic circuit triggered by the EEG R-waves or a photoelectric ear lobe pulse detector and of output devices (a feedback indicator of successful or unsuccessful heart rate control during the preceding time interval, the teletype and the paper tape punch) is described. The actual heart rate is measured and compared with levels differing from the average by a preselected number of pulses/min. When a preset criterion is met, the levels are shifted automatically. In control session shuffled data from the preceding experimental session are used for feedback.

• MeSH
• biofeedback (psychologie) fyziologie   MeSH
• lidé MeSH
• psychofyziologie přístrojové vybavení   MeSH
• srdeční frekvence * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

INTRODUCTION: Late heart rate deceleration parallels the increase of systolic blood pressure during heart rate turbulence (HRT) after ventricular premature complexes (VPC). This is consistent with the involvement of baroreflex mechanism. Physiological background of systolic blood pressure dynamics is not known. Enhanced sympathetic activation and nonautonomic post-VPC changes of stroke volume have been speculated on. METHODS AND RESULTS: We studied 28 subjects (aged 56 +/- 11 years; 20 males; 18 normal and 10 abnormal left ventricular (LV) function) with spontaneous occurrence of VPCs. HRT indices and baroreflex sensitivity were analyzed from the ECGs and finger arterial pressure recordings during 30 minutes of spontaneous respiration in supine position. Beat-by-beat stroke volume and peripheral vascular resistance were computed by a nonlinear, self-adaptive model of aortic input impedance (Modelflow, Finapres Medical Systems, Arnhem, The Netherlands). Indices of HRT and baroreflex sensitivity were highly correlated. In patients with preserved LV function, there was no substantial dynamics of stroke volume in the late phase after VPC, while peripheral vascular resistance increased significantly. In patients with impaired LV function, potentiated first sinus beat after VPC triggered transient hemodynamic alternans. Dynamics of peripheral vascular resistance was attenuated and stroke volume was depressed in the late phase after VPC. CONCLUSIONS: Delayed sympathetically mediated vasomotor response to VPC produces systolic blood pressure overshoot. This subsequently induces vagally mediated late heart rate deceleration. Under physiologic conditions, there is no evidence of other hemodynamic and/or mechanical effect outside the autonomic reflex arch. In patients with LV dysfunction, both depressed vagal and sympathetic modulation and, indirectly, enhanced postextrasystolic potentiation account for attenuated HRT.

• MeSH
• analýza rozptylu MeSH
• autonomní nervový systém patofyziologie   MeSH
• baroreflex fyziologie   MeSH
• cévní rezistence fyziologie   MeSH
• elektrokardiografie MeSH
• komorové extrasystoly patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• regresní analýza MeSH
• srdeční frekvence fyziologie   MeSH
• tepový objem fyziologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE: Excessive tachycardia in resuscitated septic shock patients can impair hemodynamics and worsen patient outcome. We investigated whether heart rate (HR) control can be achieved without increased vasopressor requirements using the titratable highly selective, ultra-short-acting β1-blocker landiolol. METHODS: This randomized, open-label, controlled trial was conducted at 20 sites in 7 European countries from 2018 to 2022 and investigated the efficacy and safety of landiolol in adult patients with septic shock and persistent tachycardia. Patients were randomly assigned to receive either landiolol along with standard treatment (n = 99) or standard treatment alone (n = 101). The combined primary endpoint was HR response (i.e., HR within the range of 80-94 beats per minute) and its maintenance without increasing vasopressor requirements during the first 24 h after treatment start. Key secondary endpoints were 28-day mortality and adverse events. RESULTS: Out of 196 included septic shock patients, 98 received standard treatment combined with landiolol and 98 standard treatment alone. A significantly larger proportion of patients met the combined primary endpoint in the landiolol group than in the control group (39.8% [39/98] vs. 23.5% [23/98]), with a between-group difference of 16.5% (95% confidence interval [CI]: 3.4-28.8%; p = 0.013). There were no statistically significant differences between study groups in tested secondary outcomes and adverse events. CONCLUSION: The ultra-short-acting beta-blocker landiolol was effective in reducing and maintaining HR without increasing vasopressor requirements after 24 h in patients with septic shock and persistent tachycardia. There were no differences in adverse events and clinical outcomes such as 28-day mortality vs. standard of care. The results of this study, in the context of previous trials, do not support a treatment strategy of stringent HR reduction (< 95 bpm) in an unselected septic shock population with persistent tachycardia. Further investigations are needed to identify septic shock patient phenotypes that benefit clinically from HR control.

• Klíčová slova
• Heart rate control, Landiolol, Persistent tachycardia, Sepsis, Septic shock, Ultra-short-acting beta-blocker,
• MeSH
• lidé středního věku MeSH
• lidé MeSH
• močovina * analogy a deriváty   terapeutické užití   farmakologie   MeSH
• morfoliny * terapeutické užití   farmakologie   MeSH
• senioři MeSH
• septický šok * farmakoterapie   komplikace   patofyziologie   MeSH
• srdeční frekvence * účinky léků   MeSH
• tachykardie * farmakoterapie   patofyziologie   komplikace   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• randomizované kontrolované studie MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• landiolol MeSH Prohlížeč
• močovina * MeSH
• morfoliny * MeSH

UNLABELLED: The aim of this study is to analyse the acute effect of water-pipe smoking on heart rate, blood pressure and the baroreflex control of heart rate. SUBJECTS AND METHODS: Non-invasive continuous methods were used for investigating inter-beat interval (IBI; ms), systolic blood pressure (SBP; mm Hg), diastolic blood pressure (DBP; mm Hg), pulse pressure (PP; mm Hg), mean blood pressure (MBP; mm Hg); baroreflex sensitivity in ms/mm Hg (BRS) and baroreflex sensitivity in Hz/mm Hg (BRSf), were determined by spectral analysis, in 20 normotensive volunteers age of 27+/-6 years (mean+/-S.D.) who served as their own control. The measurements were taken twice. The first measurement was taken before the water-pipe smoking session (this is after >12 h of smoking cessation with a complete stopping of alcohol, coffee or tea consumption). The second measurement was taken during a 5 min period immediately after that session. (In the smoking session the volunteer smokes 5 g Maassel (fruit flavoured tobacco) for a period of 45 min). RESULTS: The inter-beat interval decreased (846+/-100 to 709+/-109 ms, p=0.0003), SBP increased (110+/-13 to 123+/-12 mm Hg, p=0.004), DBP increased (67+/-11 to 81+/-11 mm Hg, p=0.0002), PP decreased (43+/-10 to 41+/-9 mm Hg, p=0.46 ns), MBP increased (82+/-10 to 95+/-11 mm Hg, p=0.0001), BRS decreased (9.16+/-4 to 5.67+/-3 ms/mm Hg, p=0.003) and BRSf (0.013+/-0.005 to 0.011+/-0.004 Hz/mm Hg, p=0.3 ns). CONCLUSIONS: Water-pipe smoking induced a high increase in heart rate, SBP, DBP, MBP and markedly impaired BRS. All of those markers are known as risk factors in cardiovascular diseases, hence it is concluded that water-pipe smoking is not as harmless as is thought.

• MeSH
• baroreflex účinky léků   fyziologie   MeSH
• dospělí MeSH
• kouření patofyziologie   MeSH
• krevní tlak fyziologie   MeSH
• lidé MeSH
• neparametrická statistika MeSH
• srdeční frekvence účinky léků   fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• srovnávací studie MeSH

BACKGROUND: Investigate real-world outcomes of early rhythm versus rate control in patients with recent onset atrial fibrillation. METHODS: The Global Anticoagulant Registry in the FIELD-AF (GARFIELD-AF) is an international multi-centre, non-interventional prospective registry of newly diagnosed (≤6 weeks' duration) atrial fibrillation patients at risk for stroke. Patients were stratified according to treatment initiated at baseline (≤48 days post enrolment), and outcome risks evaluated by overlap propensity weighted Cox proportional-hazards models. RESULTS: Of 45,382 non-permanent atrial fibrillation patients, 23,858 (52.6 %) received rhythm control and 21,524 (47.4 %) rate control. Rhythm-controlled patients had lower median age (68.0 [Q1;Q3: 60.0;76.0] versus 73.0 [65.0;79.0]), fewer histories of stroke/transient ischemic attack/systemic embolism (9.4 % versus 13.0 %), and lower expected probabilities of death (median GARFIELD-AF death score 4.0 [2.3;7.5] versus 5.1 [2.8;9.2]). The two groups had the same median CHA2DS2-VASc scores (3.0 [2.0;4.0]) and similar proportions of anticoagulated patients (rhythm control: 66.0 %, rate control: 65.5 %). The propensity-score-weighted hazard ratios of rhythm vs rate control (reference) were 0.85 (95 % CI: 0.79-0.92, p-value < 0.0001) for all-cause mortality, 0.84 (0.72-0.97, p-value 0.020) for non-haemorrhagic stroke/systemic embolism and 0.90 (0.78-1.04, p-value 0.164) for major bleeding. CONCLUSION: Rhythm control strategy was initiated in about half of the patients with newly diagnosed non-valvular non-permanent atrial fibrillation. After balancing confounders, significantly lower risks of all-cause mortality and non-haemorrhagic stroke were observed in patients who received early rhythm control.

• Klíčová slova
• Atrial fibrillation, Mortality, Rate control, Real-world evidence, Rhythm control, Stroke,
• Publikační typ
• časopisecké články MeSH

Tachyarrhythmia-induced cardiomyopathy (TIC) is a rare, yet life-threatening phenomenon in children. TIC has been defined as myocardial dysfunction that is entirely or partially reversible after control of the responsible tachyarrhythmia and is typically caused by an incessant supraventricular tachycardia. In cases of unsuccessful termination of the tachycardia, cardiogenic shock may occur. Several authors favour the use of mechanical circulatory support in such cases. Particularly with regard to these partly severe cases, the authors would like to present the option of transoesophageal overdrive pacing (TOP) as a tool for initial heart rate control and hemodynamic stabilization of patients with TIC refractory to conventional strategies of tachycardia termination. Chart review for patients receiving TOP during the last 5 years in two centres was performed. A case series of successful TOP including technique and outcomes is depicted. Rate control through TOP is a safe and effective option to restore acceptable hemodynamics in infants with refractory supraventricular tachycardia and severe impairment of ventricular function. It presents the possibility of immediate heart rate control and offers time for myocardial recovery and safe implementation of antiarrhythmic drug therapy.

• Klíčová slova
• Cardiac pacing, Children, Supraventricular tachycardia, Transoesophageal pacing,
• MeSH
• elektrokardiografie MeSH
• kardiomyopatie komplikace   MeSH
• kardiostimulace umělá škodlivé účinky   metody   MeSH
• kojenec MeSH
• komorová dysfunkce komplikace   MeSH
• lidé MeSH
• novorozenec MeSH
• srdeční frekvence * MeSH
• supraventrikulární tachykardie terapie   MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Baroreflex control of heart rate was studied in inbred salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) Dahl rats that were subjected to chronic dietary sodium chloride loading (for 4 weeks) either in youth or only in adulthood, i.e. from the age of 4 or 12 weeks. Using phenylephrine administration to pentobarbital-anesthetized male rats we have demonstrated the decreased baroreflex sensitivity (lower slope for reflex bradycardia) in young prehypertensive SS/Jr rats fed a low-salt diet as compared to age-matched SR/Jr animals. High salt intake further suppressed baroreflex sensitivity in young SS/Jr but not in SR/Jr rats. Baroreflex sensitivity decreased with age in SR/Jr rats, whereas it increased in SS/Jr rats fed a low-salt diet. Thus at the age of 16 weeks baroreflex sensitivity was much higher in SS/Jr than in SR/Jr animals. High salt intake lowered baroreflex sensitivity even in adult SS/Jr rats without affecting it in adult SR/Jr rats. Nevertheless, baroreflex sensitivity was significantly lower in young SS/Jr rats with a severe salt hypertension than in adult ones with a moderate blood pressure elevation. It is concluded that the alterations of baroreflex sensitivity in young inbred SS/Jr rats (including the response to high salt intake) are similar to those described earlier for outbred salt-sensitive Dahl rats. We have, however, disclosed contrasting age-dependent changes of baroreflex sensitivity in both inbred substrains of Dahl rats.

• MeSH
• baroreflex účinky léků   fyziologie   MeSH
• fenylefrin farmakologie   MeSH
• hypertenze chemicky indukované   patofyziologie   MeSH
• krevní tlak účinky léků   fyziologie   MeSH
• krysa rodu Rattus MeSH
• kuchyňská sůl farmakologie   MeSH
• potkani inbrední Dahl MeSH
• srdeční frekvence účinky léků   fyziologie   MeSH
• sympatomimetika farmakologie   MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• fenylefrin MeSH
• kuchyňská sůl MeSH
• sympatomimetika MeSH

The cardiovascular system is primarily controlled by the autonomic nervous system, and any changes in sympathetic or parasympathetic activity also have an impact on myocardial activity. Heart rate variability (HRV) is a readily available metric used to assess heart rate control by the autonomic nervous system. HRV can provide information about neural (parasympathetic, sympathetic, reflex) and humoral (hormones, thermoregulation) control of myocardial activity. Because there are no relevant reference values for HRV parameters in rats in the scientific literature, all experimental results are only interpreted on the basis of changes from currently measured control or baseline HRV values, which are, however, significantly different in individual studies. Considering the significant variability of published HRV data, the present study focused primarily on comparing control or baseline HRV values under different conditions in in vivo experiments involving rats. The aim of the study was therefore to assess whether there are differences in the starting values before the experiment itself.

• Klíčová slova
• heart rate variability, in vivo experiments, rats,
• MeSH
• autonomní nervový systém * MeSH
• krysa rodu Rattus MeSH
• myokard MeSH
• referenční hodnoty MeSH
• srdeční frekvence MeSH
• termoregulace * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

UNLABELLED: Listening to music is experimentally associated with positive stress reduction effect on human organisms. However, the opinions of therapists about this complementary non-invasive therapy are still different. PURPOSE: The aim of our study was to investigate the effect of selected passive music therapy frequencies without vocals on selected cardio-vagal and complexity indices of short-term heart rate variability (HRV) in healthy youth, in terms of calming the human. MAIN METHODS: 30 probands (15 male, averaged age: 19.7+/-1.4 years, BMI: 23.3+/-3.8 kg/m2) were examined during protocol (Silence baseline, Music 1 (20-1000 Hz), Silence 1, Music 2 (250-2000 Hz), Silence 2, Music 3 (1000-16000 Hz), and Silence 3). Evaluated HRV parameters in time, spectral, and geometrical domains represent indices of cardio-vagal and emotional regulation. Additionally, HRV complexity was calculated by approximate entropy and sample entropy (SampEn) and subjective characteristics of each phase by Likert scale. RESULTS: the distance between subsequent R-waves in the electrocardiogram (RR intervals [ms]) and SampEn were significantly higher during Music 3 compared to Silence 3 (p=0.015, p=0.021, respectively). Geometrical cardio-vagal index was significantly higher during Music 2 than during Silence 2 (p=0.006). In the subjective perception of the healthy youths evaluated statistically through a Likert scale, the phases of music were perceived significantly more pleasant than the silent phases (p<0.001, p=0.008, p=0.003, respectively). CONCLUSIONS: Our findings revealed a rise of cardio-vagal modulation and higher complexity assessed by short-term HRV indices suggesting positive relaxing effect music especially of higher frequency on human organism.

• MeSH
• dospělí MeSH
• elektrokardiografie MeSH
• hudba * psychologie   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nervus vagus MeSH
• srdce MeSH
• srdeční frekvence fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH