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At least 289 records · Page 16Linked to original sources
PubMed2001

Induction of JAB/SOCS-1/SSI-1 and CIS3/SOCS-3/SSI-3 is involved in gp130 resistance in cardiovascular system in rat treated with cardiotrophin-1 in vivo.

CIS (cytokine-inducible SH2 protein), SOCS (suppressor of cytokine signaling), or SSI (signal transducers and activators of transcription [STAT]-induced STAT inhibitor) proteins are a family of cytokine-inducible negative regulators of cytokine signaling via Janus kinase (JAK)-STAT pathways. Given the evidence that the JAK-STAT pathway plays a critical role in the cardiovascular system, the primary objective of this study was to assess the effects of the CIS family on JAK-STAT signaling in the cardiovascular system in rats treated with cardiotrophin-1 (CT-1), an interleukin-6 family of cytokines. Intravenous injection of 20 microgram/kg body weight of CT-1 induced a transient, marked increase in STAT3 activation in various tissues, including heart and lung, and subsequent upregulation of 2 members of the CIS family, JAK-binding protein (JAB)/SOCS-1/SSI-1 and CIS3/SOCS-3/SSI-3, in the same tissues. It was also observed that CIS3 was directly associated with JAK2 in vivo. Pretreatment with the same dose of CT-1 60 minutes before significantly attenuated the STAT3 activation induced by a second injection of CT-1. We previously reported that intravenous injection of CT-1 results in the nitric oxide (NO)-dependent hypotension accompanied by the induction of inducible NO synthase mRNA. In rats pretreated with CT-1, the induction of inducible NO synthase mRNA or hypotension by subsequent CT-1 injection was not observed. Forced expression of JAB or CIS3, but not other CISs, directly blocked CT-1-induced STAT3 activation in 293 cells. These results suggest that JAB and CIS3 serve as endogenous inhibitors of CT-1-mediated JAK-STAT signaling in the cardiovascular system in vivo.

Animals↗
PubMed1997

Participation of the pituitary-thyroid axis in the cardiovascular system in elderly patients with congestive heart failure.

The relationship between the pituitary-thyroid axis and the cardiovascular system in patients with congestive heart failure (CHF) remains unknown. Therefore, we attempted to determine serum levels of thyroid hormones in relation to plasma atrial natriuretic peptide (ANP) levels and left ventricular (LV) function in patients with CHF. The echocardiographic ejection fraction significantly correlated with the thyroid stimulating hormone (TSH) (p < 0.005) and free triiodothyronine (FT3)/free thyroxine (FT4) ratio (p < 0.005), respectively, in patients with CHF but not in control subjects. TSH was positively correlated with the FT3/FT4 ratio (p < 0.01) in CHF. In patients with CHF, TSH and thyroid hormones may participate in regulatory mechanisms of the cardiovascular system and altered thyroid hormone metabolism, which was characterized by a euthyroid sick syndrome.

Aged↗
PubMed1984

Demonstration of the fetal cardiovascular system by MR imaging.

Magnetic resonance is potentially a second imaging modality that can be used to study the fetal cardiovascular system. Magnetic resonance imaging to date has not been associated with any harmful effects and, since it does not involve ionizing radiation, we are evaluating its role in fetal imaging. We report a case in which this modality showed the unique features of the cardiovascular system.

Adult↗
PubMed1977

[Effect of training in sports on the cardiovascular system of children and adolescents].

In a review the specific reaction of the cardiovascular system of children and youth to actual athletic stress and on a staying power training is dealt with. The present knowledge is imperfect because the medicine had a cautious opinion of the maximum stress of the infantile heart till recent times, and children training systematically were exceptions. The examination of the cardiovascular system of training children is complicated as far as the effects of training are mostly equal in direction like growth, maturing, and development effects. But it is evident that the infantile circulation system is well adaptable to staying power results. During training a cardiac enlargement surpassing the growth rate is arising. Under the condition of rest the heart of the trained child is more subjected to vagal control with the appropriate functional consequences. By submaximum stress an economization of the function can be observed. During stress a stronger inotropia with increased stroke volume and better oxygen absorption is stated. The post-stress phase is characterized by an accelerated return of the deflected functions to the zero level. Furthermore statements are made about the specific ECG of sporting children, about the problems of sports at heart diseases, about acceleration and retardation as well as about the transformation of physiologic knowledge into methodical conceptions for training.

Adolescent↗
PubMed1989

[Current approaches to the study of psychosomatic effects on the pathology of the cardiovascular system in children].

A total of 131 children suffering from hereditary predisposition to coronary heart disease, 70 subjects with dysfunction of the and 120 subjects with dysfunction of the vegetative nervous system and low blood pressure were examined. The examination of the children included a study of the cardiovascular system and the vegetative nervous system as well as psychological studies. The cardiovascular system response to the psychoemotional teleplay test was measured in addition. It has been demonstrated that the psychoneurosomatic interrelations are implicated in the occurrence of the main most prevalent cardiovascular diseases in children. This determines approaches to the treatment and prevention of arterial high and low blood pressure and cardiac rhythm disorders.

Adolescent↗
PubMed1997

Parametric imaging of the chick embryonic cardiovascular system: a novel functional measure.

Morphogenesis of the cardiovascular system is likely linked to its functional development. This report presents an approach to functional assessment of early cardiovascular development using parametric imaging based on videodensitometry. Trypan blue was injected into the sinus venosus of chick embryos at stage 20 (3.5 d of incubation). Images were recorded on videotape, digitized, and analyzed by a microcomputer. A sampling window was placed over the entire image, and a densogram (time-density curve) for each pixel in the window was obtained. Parameters extracted from the densogram and its derivative were plotted in form of: 1) maximal image, 2) peak derivative image, and 3) time to peak derivative image. This approach revealed isochronal lines that divide the aortic arch and dorsal aorta into several segments. Regional flow velocity at these segments was estimated by dividing the distance between isochronal lines by the time interval. Flow velocity at the mid-systolic phase at the dorsal aorta and at the fourth aortic arch was 35.9 and 45.0 mm/s, respectively. Shear rate at the vessel wall was estimated to be 2.7 times larger at the fourth aortic arch than at the dorsal aorta. The extensive remodeling experienced by the aortic arch system compared with the dorsal aorta could be related to increased shear rate on the walls of the aortic arches.

Animals↗
PubMedDate not supplied

[Mathematical modeling of cardiovascular system in patients with hemorrhage and hypothermia].

Mathematical modeling is the most expedient method for studying the response of human cardiovascular system to a combined effect of several external factors, in particular, hemorrhage and hypothermia. A complex mathematical model integrating models of the functional systems of human body and the physiological effects of disturbing factors can be used to study the combined effect of external factors. It allows the response of human body to various combinations of external effects of different intensities to be assessed with high accuracy. In addition, the model makes it possible to prognosticate the dynamics of changes in the cardiovascular system parameters from their initial variation. This facilitates prediction of the development of patient's state.

Cardiovascular System↗
PubMed1997

Magnetic resonance imaging of the cardiovascular system and airway.

Cardiovascular MR imaging is unique in its ability to combine anatomic, physiologic, and functional information in a single examination. Established applications in the pediatric population include the evaluation of the child with a suspected thoracic aortic arch anomaly, vascular compression of the airway, coarctation of the aorta, pulmonary arterial and venous abnormalities, and cardiac or paracardiac masses. The increasing availability of radiologists with the knowledge and commitment to cardiac imaging will allow this exciting technique to thrive in the future, to the benefit of our patients.

Cardiovascular Diseases↗
PubMed1991

Pharmacological studies with the alpha 2-adrenoceptor antagonist midaglizole. Part I: Respiratory and cardiovascular systems.

Respiratory and cardiovascular effects of midaglizole (DG-5128, CAS 66529-17-7) were investigated in comparison with yohimbine, idazoxan and tolbutamide. 1. Respiration: Midaglizole had little or no effect on respiration of anesthetized dogs. Yohimbine and idazoxan augmented respiration at low dose. Tolbutamide depressed respiratory rate and depth at high dose. 2. Blood pressure and heart rate: Midaglizole produced dose-related hypotension and bradycardia in anesthetized dogs which had laparotomy, whereas it had little or no effect on blood pressure and heart rate of dogs which had no laparotomy (unlaparotomized dogs). Tendency of slight hypertension was observed after high dose of tolbutamide in laparotomized dogs, and transient hypotension was induced in unlaparotomized dogs. Yohimbine and idazoxan increased blood pressure at low dose in unlaparotomized dogs. In laparotomized dogs, yohimbine produced hypertension and hypotension at low and high doses, respectively. In isolated guinea pig atria, midaglizole produced bradycardia which was not observed after yohimbine. Tolbutamide decreased the pulse rate at high concentration. 3. Cardiac contractility: Midaglizole produced increase in cardiac contractility of anesthetized dogs. Yohimbine and idazoxan, at low dose, showed similar inotropic activity. Prazosin also produced a positive inotropic effect, whereas tolbutamide lacked the activity. The inotropic effects of midaglizole and yohimbine were antagonized by pretreatment with propranolol or hexamethonium, whereas a similar effect of prazosin was not influenced by both blockers. In isolated guinea pig atria, midaglizole showed slight inotropic activity. Yohimbine was without any effect, whereas tolbutamide reduced the contractile force. 4. Femoral blood flow: Midaglizole produced a transient increase in femoral blood flow and a decrease in femoral arterial resistance of anesthetized dogs. Yohimbine and idazoxan, at low dose, showed similar vasodilator activity. Prazosin also produced a vasodilator effect, whereas tolbutamide lacked the activity. The vasodilator effects of midaglizole and yohimbine were not affected with propranolol, but inhibited after hexamethonium. 5. Mesenteric blood flow: Midaglizole significantly decreased mesenteric blood flow and increased the arterial resistance of anesthetized dogs in a dose dependent manner. Tolbutamide induced a decrease in blood flow and an increase in arterial resistance only at the highest dose used. Yohimbine increased mesenteric blood flow at low dose and decreased it at high dose. 6. Renal blood flow: Midaglizole dose-relatedly decreased renal blood flow of anesthetized dogs. Tolbutamide and yohimbine at high dose produced a long-lasting decrease of the blood flow. Midaglizole produced a slight transient reduction of renal arterial resistance which was followed by a slight increase. Tolbutamide increased the arterial resistance at high dose.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1980

Monitoring the cardiovascular system during anesthesia.

Cardiovascular data can provide the anesthesiologist with very valuable information that enables him to take better care of his patient. This information will prove even more valuable if the following few rules are followed: (1) do not be mesmerized, confused, or preoccupied by complex equipment, (2) do not avoid paying direct attention to your patient, (3) remember to use what will provide clinically useful information and heed this information, and (4) remember that electronic monitoring is not always superior to other methods.

Anesthesia↗
PubMedDate not supplied

Potential approaches to evaluating the cardiovascular system using NMR.

The current status and some of the future possibilities for nuclear magnetic resonance imaging of the cardiovascular system have been described. With many of these possibilities there is overlap with existing techniques. For example, functional analysis of the left ventricle can be obtained using either echocardiography or radionuclide techniques. With current instrumentation and current costs, these conventional techniques could frequently provide a more cost-effective approach for morphologic and functional assessment of the cardiovascular system. Nevertheless, because of the excellent resolution, the inherent contrast, the sensitivity to blood motion, the three-dimensional nature, and the lack of ionizing radiation, the cardiovascular morphologic imaging capabilities of NMR may provide justification for such applications. However, for NMR to achieve its most important status as a cardiovascular imaging technique, some of its unique possibilities will need to be developed. These include the ability to reproducibly depict the proximal coronary arteries, to define regional myocardial blood flow distribution, to evaluate regional high energy phosphate or other metabolic activity; and to characterize myocardial disease using proton T1 and T2 alterations.

Animals↗
PubMed1989

Role of G proteins in the regulation of the cardiovascular system.

A precise description of the involvement of G proteins in regulation of the cardiovascular system is not possible at the present time although it is clear that they do have important regulatory roles. The cardiovascular system is composed of a variety of cell types, which are subject to control by several different hormones, as well as by hormones that have several different effects in the same cell type. Although, historically, variations in the type and number of receptors located on each cell have been used to explain this diversity of hormonal responses, we must now consider the large number and diversity of G proteins in any effort to understand the coordinated hormonal regulation of cellular functions. Given that there are eight known G proteins and several others have been speculated, each of which is composed of three subunits, each of which has several different forms, the possible combinations of subunits into functionally distinct G proteins is enormous. To place this newly described family of G proteins into the appropriate hormone signaling pathways will require a continued research effort. However, with recent progress in producing specific antibodies to each of the G protein subunits, it may now be possible to determine the specific receptor-effector functions of each G protein and their individual subunits.

Animals↗
PubMed1976

Norepinephrine, epinephrine, and dopamine contents of the cardiovascular system in long-term diabetics.

Norepinephrine, epinephrine, and dopamine concentrations were studied in the cardiovscular system of postmortem material obtained from six long-term diabetics and six control subjects. Norepinephrine concentration was considerably reduced in the cardiovascular system of the diabetic patients. The mean norepinephrine concentration in the apex of the heart, the radial artery, the posterior tibial artery, and the femoral artery in the diabetics averaged 6, 9, 12, and 20 per cent, respectively, of the corresponding mean values in the controls. Epinephrine was present in the cardiovascular system in the controls but in small amounts in comparision with norepinephrine. There was no correlation between the epinephrine and the norepinephrine concentrations in the tissue. In the diabetics the epinephrine concentration in the heart and in the arteries did not differ from the values obtained in the controls. The dopamine concentration averaged 11 per cent of the norepinephrine concentration in the cardiovascular system in the controls. There was a strong correlation between tissue concentrations of dopamine and of norepinephrine. In the diabetics the dopamine concentration was reduced, but relatively less than that of norepinephrine, and constituted 53 per cent of the norepinephrine concentration. It is suggested that the depletion of the norepinephrine stores in the heart in diabetic patients may in part be responsible for their reduced survival rate in acute myocardial infarction.

Adult↗
PubMed1997

Noninvasive assessment of the developing Xenopus cardiovascular system using optical coherence tomography.

Studies investigating normal and abnormal cardiac development are frequently limited by an inability to assess cardiovascular function within the intact organism. In this work, optical coherence tomography (OCT), a new method of micron-scale, noninvasive imaging based on the measurement of backscattered infrared light, was introduced for the high resolution assessment of structure and function in the developing Xenopus laevis cardiovascular system. Microstructural details, such as ventricular size and wall positions, were delineated with OCT at 16-microm resolution and correlated with histology. Three-dimensional representation of the cardiovascular system also was achieved by repeated cross-sectional imaging at intervals of 25 microm. In addition to structural information, OCT provides high speed in vivo axial ranging and imaging, allowing quantitative dynamic activity, such as ventricular ejection fraction, to be assessed. The sensitivity of OCT for dynamic assessment was demonstrated with an inotropic agent that altered cardiac function and dimensions. Optical coherence tomography is an attractive new technology for assessing cardiovascular development because of its high resolution, its ability to image through nontransparent structures, and its inexpensive portable design. In vivo and in vitro imaging are performed at a resolution approaching that of histopathology without the need for animal killing.

Animals↗
PubMed1985

Effects of an indazole derivative, FKK, a novel bronchodilator, on the cardiovascular system in dogs.

The cardiovascular effects of FKK (2,3-dihydro-7-methyl-9-phenyl-1H-pyrazolo [1,2-a]indazolium bromide) were compared with those of aminophylline and isoproterenol in anesthetized dogs. The doses of the three drugs used were sufficient to cause significant tracheal dilation in the anesthetized dogs. FKK (0.1-3.0 mg/kg, i.v.) slightly increased respiratory frequency, left ventricular (LV) dp/dt max and myocardial contractile force. A slight increase followed by a decrease was observed in systemic blood pressure and LV systolic pressure. The drug caused direct vasodilation in the coronary, mesenteric and femoral vasculatures, but had no effect on the renal vasculature. Similar results were obtained with aminophylline (0.3-30.0 mg/kg, i.v.) and isoproterenol (0.003-0.3 microgram/kg, i.v.), but their effects on the measured cardiac parameters were much more potent and long-lasting than those of FKK, when compared in doses producing a bronchodilation in similar magnitude. It is particularly pertinent that FKK (30 mg/kg, i.d., enough to cause marked bronchodilation), unlike aminophylline (30 mg/kg, i.d.), did not significantly influence the cardiovascular system.

Aminophylline↗
PubMed1986

[Radionuclide evaluation of the cardiovascular system in arterial hypertension].

Proceeding from a study of the nature of changes in hemodynamics during development of hypertensive disease (HD) at its different stages it was shown that hemodynamic changes in 42.1% of the patients with Stage I-IIA HD were of hypertensive type, in the patients with Stage IIB-III HD normal and hypokinetic types of the blood circulation prevailed. After bicycle ergometry exercise the reactivity of the cardiovascular system was revealed more completely. The transition of one hemodynamic type into another and its detection acquired a great importance. The definition of the types of hemodynamics at rest and of effort was very important in terms of adequate antihypertensive therapy and the prediction of a subsequent course of disease. The most complete information on function of the cardiovascular system and myocardial contractility can be obtained with the help of radio-angiocardiography and radionuclide ventriculography. However in the absence of a gamma-chamber radiocardiography can provide necessary information on function of the cardiovascular system in case it is used in one and the same patient over time using bicycle ergometry testing.

Cardiovascular System↗
PubMed2001

A mathematical model of the fetal cardiovascular system based on genetic algorithms as identification technique.

The development of fetal cardiac surgery, considered the ultimate goal in the treatment of congenital cardiac malformations, needs to be supported by detailed knowledge of the blood circulation in the fetal cardiovascular system. The hemodynamic behavior in distal territories is usually inferred from vessel resistance indices, which give limited physiological information. This study presents a mathematical model of the human fetal global cardiovascular system, developed to clarify the relationships and differences existing between upper and lower body circulation. We modelled the heart with two time-varying capacitances, each representing the respective ventricle's pressure-volume relationship. The fetal vascular system was represented using two six-element Windkessel models, for the upper and lower body respectively. We obtained the identification of the set of circuital and elastance function parameters of the model using Genetic Algorithms (GAs), which follow the laws of evolutionary theory. We compared the results of our numerical study on the model identified with data collected from measurements and literature, to validate the proposed global cardiovascular system model of the human fetus. This model is intended as an instrument to investigate the differences in blood distribution between the different vascular districts in the upper and lower fetal body and the role of the aortic isthmus, the small tract of vessel connecting upper and lower fetal vascular beds; it may also represent a useful tool in the assessment of dynamic balance during mechanical assistance of circulation.

Algorithms↗
PubMed2001

[Effect of 12-hour work shifts of dispatchers of electric networks on their cardiovascular systems].

Blood pressure, heart rate and haemodynamics parameters in dispatchers of electric networks were studied in productive conditions under two days rotation of 12-hour shifts (17 subjects, 1224 subject-observations). It was revealed, that taking and giving periods of the shifts activate cardiovascular system work to the pronounced extent (significant increase of blood pressure at the beginning and in the end of the shifts and heart rate--at the beginning of the shifts). That is accompanied with unfavourable changes of bloodcirculation selfregulation (BCS): Predominantly heart BCS that is forming at the beginning of the shifts, especially in the evening, gradually convert towards the mainly vascular one, that is especially pronounced after 8 hours of continuous working in the day shifts. Significant predominance of the vascular BCS is noted during second consecutive day shifts, predominance of the heart BCS is noted during second consecutive night shifts. This evidences the difficulty of the second consecutive 12-hour shifts to be maintained from the cardiovascular system. Breaking of BCS, that is repeated systematically, can promote forming of the steady unfavourable changes of dispatchers' cardiovascular system state.

Adult↗