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5492. Head-up tilt rapidly compromises hemodynamics in healthy anesthetized swine
- Creator:
- Mikuláš Mlček, Jan Bělohlávek, Michal Huptych, Tomáš Bouček, Belza, T., Lacko, S., Krupickova, P., Hrachovina, M., Popkova, M., Petr Neužil, and Otomar Kittnar
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, hemodynamika, hemodynamics, head-up tilt, pressure-volume loop, cardiac output, swine, oximetry, 14, and 612
- Language:
- English
- Description:
- The aims were to explore the effect of head-up tilt (HUT) to 30 and 60 degrees on hemodynamics and tissue oxygenation in anesthetized healthy swine. The data serve as a reference for a study of resuscitation efficacy at HUT such as during transport. Nine healthy swine (49±4 kg) were anesthetized and multiple sensors including myocardial pressure-volume loops catheter, carotid flow probe, blood pressure catheters, near infrared spectroscopy (NIRS) tissue oximetry and mixed venous oximetry (SVO2) catheter were introduced and parameters continuously recorded. Experimental protocol consisted of baseline in supine position (15 min), 30 degrees HUT (15 min), recovery at supine position (15 min) and 60 degrees HUT (5 min). Vacuum mattress was used for body fixation during tilts. We found that 30 and 60 degrees inclination led to significant immediate reduction in hemodynamic and oximetry parameters. Mean arterial pressure (mm Hg) decreased from 98 at baseline to 53 and 39, respectively. Carotid blood flow dropped to 47 % and 22 % of baseline values, end diastolic volume to 49 % and 53 % and stroke volume to 47 % and 45 % of baseline. SVO2 and tissue oximetry decreased by 17 and 21 percentage points. The values are means. In conclusions, within minutes, both 30 and 60 degrees head-up tilting is poorly tolerated in anesthetized swine. Significant differences among individual animals exist., M. Mlcek, J. Belohlavek, M. Huptych, T. Boucek, T. Belza, S. Lacko, P. Krupickova, M. Hrachovina, M. Popkova, P. Neuzil, O. Kittnar., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5493. Heart failure and angiotensin converting enzyme inhibition: problems and perspectives
- Creator:
- Fedor Šimko and Šimko, J.
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, srdeční selhání, heart failure, ACE inhibitors, Angiotensin II receptor antagonists, beta-blockers, local angiotensin II, chymase, neurohumoral activation, 14, and 612
- Language:
- English
- Description:
- Heart failure has become the most widely studied syndrome in cardiology over the recent years. Despite the encouraging achievements by angiotensin converting enzyme (ACE) inhibitors, the mortality of patients with chronic heart failure remains high. There are several factors which can potentially be responsible for the fact that about 80% of patients with a failing heart defy protection by ACE inhibitors: different activation of tissue and systemic renin-angiotensin system (RAS) in a particular heart disease and the distinct ability of various ACE inhibitors to block cardiac ACE, alternative pathways for angiotensin II formation (chymase), genetic polymorphism of the RAS system and the complexity of neuroendocrine activation. Moreover, chronic heart failure can provoke disturbances in the reactivity of peripheral vessels and metabolism of striated muscles. These factors may then potentiate the vicious circle of heart failure. New therapeutic approaches, which could further reduce the mortality in patients with heart failure involve angiotensin II type 1 receptor antagonists, beta-blockers, aldosterone antagonists and blockers of the endothelin receptor. A number of questions associated with functions of the RAS still remain open and their solution could be of substantial benefit for patients with a failing heart., F. Šimko, J. Šimko., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5494. Heart rate and increased intravascular volume
- Creator:
- Miroslav Souček, Tomáš Kára, Pavel Jurák, Josef Halámek, Lenka Špinarová, Meluzín, J., Toman, J., Ivan Řiháček, Josef Šumbera, and Petr Fráňa
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, ledviny, srdeční rytmus, kidneys, heart rate, atrial mechanisms, intravascular volume, breathing, 14, and 612
- Language:
- English
- Description:
- The objective was to establish whether an intravascular volume increase leads to a heart rate (HR) increase without increased sympathetic tonus. HR changes at rest and at deep breathing (6/min - simulated increase of atrial filling pressure) were measured in patients after heart transplantation. Evaluation of dependency of HR changes on breathing depth was done through a new time series methodology. The data was evaluated through graphs displaying a significant increase in the graph area at deep breathing, when compared with breathing at rest (p < 0.01). We presume that an increase in HR corresponds to increased intravascular volume and malfunctioning kidneys., M. Souček, T. Kára, P. Jurák, J. Halámek, L. Špinarová, J. Meluzím, J. Toman, I. Řiháček, J. Šumbera, P. Fráňa., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5495. Heart rate variability and inflammatory response in rats with lipopolysaccharide-induced endotoxemia
- Creator:
- Ivan Žila, Daniela Mokrá, Kopincova, J., Kolomaznik, M., Michal Javorka, and Andrea Čalkovská
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, srdeční rytmus, autonomní nervový systém, heart rate, autonomic nervous system, heart rate variability, interleukin 6, lipopolysaccharide, endotoxemia, rat model, 14, and 612
- Language:
- English
- Description:
- The aim of the study was to evaluate short-term heart rate variability (HRV) as an index of cardiac autonomic control in rats with lipopolysaccharide (LPS)-induced endotoxemia. Animals were injected intraperitoneally with LPS (100 μg/kg b.w.) and control group with an equivalent volume of saline. ECG recordings were done before (base) and 60, 120, 180, 240 and 300 min after LPS or saline administration. HRV magnitude was quantified by time and frequency-domain analysis (mean RR interval, SDRR, RMSSD, spectral powers in low (LF) and high frequency (HF) bands. Heart tissue homogenates and plasma were analyzed to determine interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and oxidative stress level (TBARS). Administration of lipopolysaccharide was followed by continuous rise in colonic body temperature compared to saline-treated controls. Endotoxemia in rats was accompanied by significant decrease in HRV spectral activity in high-frequency range at maximal body temperature (logHFpower: 1.2±0.5 vs. 1.9± 0.6 ms2, P<0.01). Increased IL-6 was found in heart tissue homogenates of LPS rats (8.0±0.6 vs. 26.4±4.8 pg/ml, (P<0.05). In conclusions, reduced HRV in HF band may indicate a decreased parasympathetic activity in LPS-induced endotoxemia as basic characteristics of altered cardiac control during response to endotoxemia., I. Zila, D. Mokra, J. Kopincova, M. Kolomaznik, M. Javorka, A. Calkovska., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5496. Heart rate variability in newborns
- Creator:
- Kamil Javorka, Lehotska, Z., Kozar, M., Uhrikova, Z., Branislav Kolarovszki, Michal Javorka, and Mirko Zibolen
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- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, novorozenci, autonomní nervový systém, srdeční rytmus, newborns, autonomic nervous system, heart rate, premature newborn, heart rate variability, postnatal adaptation, 14, and 612
- Language:
- English
- Description:
- Heart rate (HR) and heart rate variability (HRV) in newborns is influenced by genetic determinants, gestational and postnatal age, and other variables. Premature infants have a reduced HRV. In neonatal HRV evaluated by spectral analysis, a dominant activity can be found in low frequency (LF) band (combined parasympathetic and sympathetic component). During the first postnatal days the activity in the high frequency (HF) band (parasympat hetic component) rises, together with an increase in LF band and total HRV. Hypotrophy in newborn can cause less mature autonomic cardiac control with a higher contribution of sympathetic activity to HRV as demonstrated by sequence plot analysis. During quiet sleep (QS) in newborns HF oscillations increase - a phenomenon less expressed or missing in premature infants. In active sleep (AS), HRV is enhanced in contrast to reduced activity in HF band due to the rise of spectral activity in LF band. Comparison of the HR and HRV in newborns born by physiological vaginal delivery, without (VD) and with epidural anesthesia (EDA) and via sectio cesarea (SC) showed no significant differences in HR and in HRV time domain parameters. Analysis in the frequency domain re vealed, that the lowest sympathetic activity in chronotropic cardiac chronotropic regulation is in the VD group. Different neonatal pathological states can be associated with a reduction of HRV and an improvement in the health conditions is followed by ch anges in HRV what can be use as a possible prognostic marker. Examination of heart rate variability in neonatology can provide information on the maturity of the cardiac chronotropic regulation in early postnatal life, on postnatal adaptation and in pathological conditions about the potential dysregulation of cardiac function in newborns, especially in preterm infants., K. Javorka, Z. Lehotska, M. Kozar, Z. Uhrikova, B. Kolarovszki, M. Javorka, M. Zibolen., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5497. Heart rate, body temperature and physical activity are variously affected during insulin treatment in alloxan-induced type 1 diabetic rat
- Creator:
- Howarth, F. C., Jacobson, M., Shafiullah, M., Ljubisavljevic, M., and Adeghate, E.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, srdeční rytmus, tělesná teplota, diabetes mellitus, inzulin, heart rate, body temperature, insulin, physical activity, alloxan, 14, and 612
- Language:
- English
- Description:
- Diabetes mellitus is associated with a variety of cardiovascular complications including impaired cardiac muscle function. The effects of insulin treatment on heart rate, body temperature and physical activity in the alloxan (ALX)-induced diabetic rat were investigated using in vivo biotelemetry techniques. The electrocardiogram, physical activity and body temperature were recorded in vivo with a biotelemetry sy stem for 10 days before ALX treatment, for 20 days following administration of ALX (120 mg/kg) and thereafter, for 15 days whilst rats received daily insulin. Heart rate declined rapi dly after administration of ALX. Pre-ALX heart rate was 321 ± 9 beats per minute, falling to 285 ± 12 beats per minute 15-20 days after ALX and recovering to 331±10 beats per minute 5-10 days after commencement of insulin. Heart rate variabilit y declined and PQ, QRS and QT intervals were prolonged after administration of ALX. Physical activity and body temperature declined after administration of ALX. Pre-ALX body temperature was 37.6 ± 0.1 °C, falling to 37.3 ± 0.1 °C 15-20 days after ALX an d recovering to 37.8±0.1 °C 5-10 days after commencement insulin. ALX-induced diabetes is associated with disturbances in heart rhythm, physical activity and body temperature that are variously affected during insulin treatment., F. C. Howarth ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5498. Heat adaptation of protein synthesis in wheat. A phenomenon besides heat shock response
- Creator:
- Weidner, M., Ohm, S., and Pohl, C.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- Translational efficiency of wheat ribosomes was studied as a function of an in vivo temperature pretreatment of wheat seedlings. The ribosomes were isolated from 41 oř 36 oC-adapted and non-adapted (20 oQ wheat seedlings. The poly-U-dependent translational efficiency, measured as ^H phenylalanine incorporation into poly-Phe, was enhanced up to 3-fold in the heat-adapted ribosomes. The adaptive enhancement was due to the large ribosomal subunit, as demonstrated earlier by heterologous recombination of ribosomal subímits, obtained from the plants pretreated by different temperatures. According to this, the pattem of ribosomal proteins of the large subunit exhibited pronounced differences as a function of preadaptation temperature: one spot increased markedly in the protein staining intensity on the two-dimensional polyacrylamide gels, while another almost disappeared. Two minor protein spots disappeared at high preadaptation temperatures. An evaluation of the protein phosphorylation of ribosomal proteins yielded a decreased ^zp-iabel degree in čase of the smáli subunit of heat-adapted ribosomes. These results are considered to be an important molecular correlation to phenotypical temperature adaptatíon of in vivo protein synthesis in wheat, where the optimum temperature of ^‘♦C-leucine incorporation into the total protein fraction, as a measure of in vivo protein synthesis, shifts to higher grades with increasing preadaptation temperature of the wheat seedlings. Besides Triticum aestivum L. (spring wheat; cv. Kolibri), heat adaptatíon potentíals of T. dicoccoides (tetraploid), T. longissimum (2n), T. monococcum (2n), T speltoides (2«) and T. tauschii (2n) were investígated. The temperature coefficient p (apparent actívation energy) also underwent adaptive alteratíons, although these changes were not unidirectíonal. T. tauschii proved to be the species with the most pronounced adaptive potentíal in the high temperature range, surpassed only by the heat adaptability of 14 d-postanthesis caryopses: its optimum temperature of in vivo protein synthesis rose by more than 20 «€ after a 38 oC-preadaptation period (2 d).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5499. Heat shock proteins HSP70 and HSP60 in in Echinococcus Granulosus Protoscolices
- Creator:
- Martinez, Javier, Péres-Serrano, Jorge, Bodega, Guillermo, Casado, Nieves, and Rodriguez-Caabeiro, Filomena
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- English
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5500. Heat stress prevents the decrease in succinate dehydrogenase activity in the extensor digitorum longus of streptozotocin-induced diabetic rats
- Creator:
- Nonaka, K, Une, S, Akiyama, J, Yamaji, R, and Komatsu, M
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- Type:
- model:article and TEXT
- Subject:
- fyziologie člověka, human physiology, Diabetes mellitus, Heat stress, Succinate dehydrogenase, Heat shock protein 60, Superoxide dismutase 2, 14, and 612
- Language:
- English
- Description:
- This study aimed to investigate whether heat stress (HS) prevents a decrease in succinate dehydrogenase (SDH) activity and heat shock protein 60 (HSP60) and superoxide dismutase 2 (SOD2) contents in the extensor digitorum longus of streptozotocin (STZ)-induced diabetic rats. Twelve-week-old male Wistar rats were assigned to one of the four groups (n=6/group): control (Con), HS, diabetes mellitus (DM), and diabetes mellitus and heat stress (DM+HS). Diabetes was induced by the administration of STZ (50 mg/kg). HS was initiated 7 days after STZ treatment and performed at 42 °C for 30 min 5 times a week for 3 weeks. SDH activity was decreased in the DM and DM+HS groups. However, SDH activity was greater in the DM+HS group than in the DM group. Although HSP60 content was lower in the DM group than in the Con group, it was maintained in the DM+HS groups and was higher than that in the DM group. SOD2 content was decreased only in the DM group. These findings suggest that HS prevents the decrease in SDH activity in the skeletal muscle induced by DM. According to this mechanism, the maintenance of SOD2 and HSP60 by HS may suppress the increase in oxidative stress., K. Nonaka, S. Une, M. Komatsu, R. Yamaji, J. Akiyama., and Seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public