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intracellular ph of cardiac muscle after administration of potassium-magnesium-aspartate (author's transl).27 sprague-dawley rats were anesthetized with pentobarbital. artificial ventilation was given by a starling pump respirator via a tracheal tube. intracellular ph of cardiac muscle was determined by means of the indirect procedure of measuring the distribution of 5,5-dimethyl-2,4-oxazolidinedione (dmo) in intra- and extracellular spaces (dmo-method). 12 rats were injected i.p. with 0.33 mval potassium-magnesium-aspartate/100 g body weight and 15 rats served as controls. using a regression analysi ...19753185
pulsus alternans in regionally hypoxic ventricles of open-chest dogs: regional mechanical alternation of potentiation and attenuation of the inotropic state.sustained mechanical alternation appeared after a spontaneous premature ventricular contraction in 6 open-chest dogs during the perfusion of the left circumflex coronary artery by krebs-henseleit solution equilibrated with 5% co2 and 95% n2. the animals were instrumented with a catheter in the left ventricle and ultrasonic crystals in hypoxic and control segments. left ventricular systolic pressure was significantly higher in the strong than in the weak beats with no significant difference of en ...197994997
nationwide residues of organochlorine compounds in starlings (sturnus vulgaris), 1976.organochlorine pesticide and pcb residues in starlings from 126 sites within the contiguous 48 states were monitored during fall 1976. the average nationwide level of dde and pcbs has increased significantly since 1974, but the number of sites reporting pcb residues has decreased fivefold. dieldrin residues have remained unchanged since 1974. highest dde levels occurred in samples from parts of arizona, arkansas, california, louisiana, and new mexico.1979111216
intramyocardial pressure: effect of preload on transmural distribution of systolic coronary blood flow.impairment of systolic coronary blood flow (cbf) may be mediated by intramyocardial pressure (pim). however, the effect of systole on the magnitude and transmural distribution of coronary blood flow has not been investigated. the purpose of this study was to measure this effect, and, indirectly, intramyocardial pressure. it is assumed that intramyocardial pressure acts on the coronary vessels as a starling resistor, such that local coronary blood flow is determined by the equation: coronary perf ...1975124128
consequences of myocardial structural adaptation on left ventricular compliance and the frank-starling relationship in spontaneously hypertensive rats.the frank-starling relationship of hearts from adult spontaneously hypertensive rats (shr, okamoto 1969), representing the established phase of hypertension, and of young shr, representing the initial phase of hypertension, was investigated by using the isolated working heart preparation. in the "normal" diastolic pressure range (5 to 10 cm h2o), the left ventricle of both shr groups displayed significantly reduced stroke volumes compared with hearts of normotensive controls (ncr); the degree of ...1975125525
[interstitial transudation with postural changes in man].starling-landis concepts of formation of interstitial fluids are in agreement with measurements of calf volume in normal young women, in horizontal recumbency or after horizontal immersion. the volume of the calf is reduced when the hydrostatic pressure of the blood column is diminished under the phlebostatic level and when the external pressure is increased by the hydrostatic pressure of the water bath.1979158412
attempted experimental transmission of pseudorabies virus to european starlings (sturnus vulgaris).forty european starlings (sturnus vulgaris) were inoculated orally with pseudorabies virus. subsequent attempts to isolate the virus from feces, liver, lung and kidney of the birds were negative; antibody against the virus could not be detected in their serums.1978206733
[experimental control of the dye dilution method of measuring telediastolic ventricular volume by the steps in the curve of indicator "washing"].after a brief discussion on the basis of the dilution method for determination of telediastolic volume (tdv) of the ventricles, the authors described the results from their own experimental studies on 8 nonbred dogs, on whom 186 curves of indicator "washing" (of the dye "cardiogreen" were recorded, presented on 2 tables. the results showed that the measurements should be made by means of the later steps of the curves. tdv and accordingly the relative stroke volume of both ventricles differed sli ...1977338287
the frank--starling curve. 1978340114
[the anatomical and histological investigation of the pancreas in the 19th century and till the discovery of insulin (1921). 4. the pancreas-research after the discovery of pancreas-diabetes (1889) till the discovery of insulin].in this study is the history of the pancreas-research between 1889 and 1921 described. in this period are any important discoverys detected: the islets have 2 cell types (tschassow-nikow 1900, 1906); the connection between diabetes mellitus and islet-alterations (opie 1900); the independence of islets on exocrine parenchyma (schulze 1900); the discovery of internal secretion (bayliss, starling 1902) and the regeneration of islets in mammals and the man (kyrle 1908; weichselbaum 1908 in independe ...1978369404
evidence of frank-starling effect in man during severe semisupine exercise. 1979421307
physiological actions of angiotensin ii on the kidney.the importance of angiotensin as a modulator of renal function is well documented. several lines of evidence suggest strongly that angiotensin plays an important role in the maintenance of renal vascular resistance and arterial pressure in several physiological and pathophysiological states with increased activity of the renin-angiotensin system. angiotensin also acts as a physiological "brake" on excessive release of renin from juxtaglomerular cells. angiotensin influences renal sodium excretio ...1979456613
organochlorine pesticide residues in animals of tasmania, australia-1975-77.animals taken in tasmania including duck (anas superciliosa), eel (anguilla australis), english perch (perca fluviatilis), white-faced heron (ardea pacifica), brown trout (salmo trutta), european starling (strunus vulgaris), cat (felis cattus), cormorant (phalacrocorax sp.), mutton bird (puffinus tenuirostris), tasmanian devil (sarcophilus harrisii), rainbow trout (salmo gairdnerii), tasmanian raven (corvus mellori), tench (tinca tinca), and quail (coturnix sp.) were sampled for p,p'-dde, pp,p'- ...1979537866
experimental transmission of chlamydia psittaci to turkeys from wild birds.wild birds were inoculated with chlamydia psittaci to determine species that could be potential hosts and vectors in transmitting the agent to domestic turkeys. infection occurred in turkeys exposed to starlings (sturnus vulgaris), common grackles (quiscalus quiscula), brown-headed cowbirds (molothrus ater), and inca doves (cardafella inca). mourning doves (zenaidura macroura) shed the agent sparingly, but turkeys exposed to them did not become infected, these findings and knowledge of the habit ...1979546413
haemodynamic changes during tilt after autonomic blockade in spontaneously hypertensive rats.the haemodynamic shifts during head up and head down tilt were investigated in adult spontaneously hypertensive rats (shr) and matched normotensive control rats (ncr) under nembutal anaesthesia and autonomic blockage. during head up tilt a greater fall in blood pressure and stroke volume was observed in shr than in ncr, while the reverse was true when tilted in the opposite direction. this altered cardiac response to venous filling, also observed in patients with essential hypertension, is sugge ...1977603871
extent of utilization of the frank-starling mechanism in conscious dogs.the extent to which an increase in preload increases left ventricular (lv) end-diastolic (ed) diameter (d) was studied in seven conscious dogs instrumented with ultrasonic d transducers and miniature lv pressure (p) gauges. preload was elevated by three techniques: 1) volume loading with saline infusion, 2) induction of global myocardial ischemia by constricting the left main coronary artery, and 3) infusion of methoxamine. these three interventions increased lvedp to over 30 mmhg from a control ...1978645872
occurrence and attempted transmission of toxoplasma gondii in european starlings (sturnus vulgaris).serums of 563 fledgling starlings (sturnus vulgaris) trapped during a 14 month period near lodi, california were examined for antibodies to toxoplasma gondii using the microtiter indirect hemagglutination method. titers ranging from 1:64 to 1:512 were found in 4.8% of the birds. starlings collected during may through october had a higher prevalence of antibody than those collected during november through april. rats inoculated with individual heart and brain suspensions from 10 seropositive star ...1978650781
the prevalence of serum antibodies to toxoplasma gondii in ontario mammals.the prevalence of seropositive reactions to toxoplasma gondii was studied in farm animals, companion animals, wild rodents and birds. of the animals tested, 17% of cattle, 65% of sheep, 45% of pigs, 9% of horses, 33% of dogs and 20% of cats were seropositive by the sabin-feldman dye test. in addition 11% of mice (mus musculus), 5% of deer mice (peromyscus), 3% of rats (rattus norvegicus) and less than 2% of sparrows (passer domestcus) were seropositive. all samples from short-tailed field mice ( ...1978667705
cardiac performance: significance of the frank--starling mechanism at low inotropy. 1978705224
[intensity of action of inotropic interventions in different degrees of myofibril stretch; apparent interrelation between the frank-starling mechanism and cardiac inotropism]. 1978718460
[pigmentation of feather primordium achieved by grafting of retinal pigment epithelium].small fragments of the retinal pigmented epithelium from white leghorn, rhode island red chick embryos, and from quail, starling and red partridge embryos, were grafted into the wing bud of white leghorn chick embryos. retinal pigmented epithelium of white leghorn chick embryos did not give rise to pigmentation of feather primordia in the hosts. in contrast, 60% of grafts from rhode island red, quail, starling and red partridge, gave rise to feather primordia whose pigmentation was identical to ...1978747782
cardiovascular adjustments to exercise: hemodynamics and mechanisms.the integrated response to severe exercise involves fourfold to fivefold increases in cardiac output, which are due primarily to increases in cardiac rate and to a lesser extent to augmentation of stroke volume. the increase in stroke volume is partly due to an increase in end-diastolic cardiac size (frank-starling mechanism) and secondarily due to a reduction in end-systolic cardiac size. the full role of the frank-starling mechanism is masked by the concomitant tachycardia. the reduction in e ...1976790460
application of the starling resistor concept to the lungs during cppv.the application of the starling resistor concept of the lungs during continuous positive pressure ventilation (cppv) was evaluated. ventilation and hemodynamics were studied in eight anesthetized and paralyzed dogs before and during the use of cppv. cppv resulted in an increase in transpulmonary pressure and functional residual capacity (frc), and a decrease in arterial ph and mixed venous oxygen tension (pvo2). cardica index decreased 32% (p less than 0.01) and stroke volume 51% (p less than 0. ...197714809
regulation of glomerular filtration and proximal tubule reabsorption.in this review current hypotheses for the regulation of filtration rate and the subsequent reabsorption of that filtrate by the proximal tubule are discussed. in the rat the filtration rate is highly plasma flow dependent because of the phenomenon of filtration equilibrium. on the other hand, in man and dog filtration rate is much less dependent on renal plasma flow. in these species glomerular capillary pressure rather than glomerular plasma flow may be the primary determinant of filtration. th ...1975805670
the coordination of gastrointestinal hormones and the autonomic nerves.we have conducted investigations on the relationship between gastrointestinal hormones and the autonomic nervous system. in this paper are described main themes of our investigations where a close association between gastrointestinal hormones and the autonomic nervous system was shown from the functional and morphological points of view. the "nervism" proposed by pavlov, where the regulation of various organs in the body was thought to be accomplished wholly by the nervous system, was based on t ...1978645686
isolation of salmonella hessarek from starlings (sturnus vulgaris).salmonella hessarek was isolated from dead starlings which were part of a large population wintering in israel. isolation techniques and laboratory inoculation of birds are described.1977843299
functional and metabolic features of an isolated perfused guinea pig heart performing pressure-volume work.cardiac performance and some parameters of glycolytic and oxidative metabolism were analyzed in isolated perfused guinea pig hearts performing pressure-volume work. perfusion medium was an oxygenated krebs-henseleit bicarbonate buffer (ph 7.4) which contained glucose and physiological concentrations of pyruvate and insulin. the pressure-flow relationship in the coronary vascular bed indicated autoregulation of coronary flow. left ventricular function was influenced by aortic pressure (pa) and ve ...1979573465
systolic time intervals and other cardiovascular changes following leg elevation.cardiovascular responses were noninvasively monitored as the legs of 16 supine human subjects were passively elevated to increase return of blood to the heart. forearm vasodilation occurred promptly as previously observed by roddie and shepard (7). arterial pressure and heart rate were unchanged. ventricular performance, monitored by systolic-time-interval analysis, was enhanced after a delay of approximately 6 s, an effect which lasted throughout the 40-s leg-elevation period. all affected vari ...1979526216
mechanism of inhibition of proximal tubule fluid reabsorption after exposure of the rat kidney to the physical effects of expansion of extracellular fluid volume.the natriuresis and concomitant decline in absolute proximal reabsorption (apr) that occur in rats in response to saline loading are blunted markedly when renal perfusion pressure is reduced immediately before, but not after, the volume load. to ascertain the mechanism responsible for these differences between early clamp (ec) vs. late clamp (lc), intracapillary and interstitial determinants of peritubular capillary uptake of apr were measured in seven lc and seven ec munich-wistar rats before a ...1979500820
regulation of cardiac output during rapid volume loading.interactions between heart rate (hr) and the frank-starling mechanism in augmenting cardiac output (co) during acute volume loading were studied in dogs under varying conditions. in normal conscious dogs with low hrs of 70--90 beats/min, end-diastolic diameter (edd) was maximal and co was increased reflexly by cardioacceleration. by contrast, anesthetized open-chest dogs with high hrs ranging from 140 to 160 beats/min, responded with bradycardia and co was adjusted solely by increasing stroke vo ...1979474792
systolic time intervals during combined hand cooling and head-up tilt.cardiac effects initiated by hand cooling and head-up tilt, separately and in combination, were studied in human subjects. systolic and diastolic arterial pressures, heart rate, pre-ejection period (pep), and left ventricular ejection time (lvet) were measured while subjects were resting supine, supine with hand immersed in 10 degrees c water, tilted 70 degrees head up, and hand immersed during head-up tilt. hand immersion and head-up tilt individually increased diastolic blood pressure and conc ...1979454319
an analysis of water movement between myocardial tissue and capillary blood during reactive hyperemia.the colloid osmotic pressure (cop) of blood from the great cardiac vein was continuously measured by means of a membrane colloid osmometer during the reactive hyperemia following temporary occlusion of the anterior descending branch of the left coronary artery in anesthetized open-chest dogs. the cop increased sharply after releasing the occlusion, then decreased below the preocclusion level before gradually returning to it. these findings indicate that a measurable amount of water moved from th ...1979449120
normal left ventricular function.the starling relationship in the normal human ventricle may be different than usually portrayed. in normal, resting, supine man the ventricular function curve is at its peak at a left ventricular end-diastolic pressure of approximately 10 mm hg. below this point is a strong direct relation between filling pressure and stroke work, while at higher filling pressures, a plateau occurs. limitation of ventricular response is related to a sharply rising ventricular pressure-volume curve at a normal le ...1979376177
ionic basis of myocardial contractility.knowledge about the basic physiology of mammalian cardiac muscle has lagged behind that of skeletal muscle because the tissue is more difficult to deal with experimentally. the cells are much smaller, they do not tolerate anaerobic conditions very well, and they cannot be tentanized. therefore as knowledge has developed about skeletal muscle, there has been a tendency to extrapolate to the myocardium. in many instances such extrapolation has been misleading especially in the area of ionic contro ...1977324352
acute hypoproteinemic fluid overload: its determinants, distribution, and treatment with concentrated albumin and diuretics.we simulated the use of massive volumes of crystalloid fluids as a treatment of acute plasma loss in a standardized experimental model and studied the factors determining the retention or excretion of the resulting acute hypoproteinemic fluid overload, its distribution within the body, and its treatment with concentrated albumin and diuretics. in accordance with the classic starling concept, the serum protein level, i.e. the serum colloid osmotic pressure, determined the excretion/retention rati ...1977919420
demonstration of two different types of beta1-receptors in man (selective blockade of the positively inotropic and the positively chronotropic effect of isoproterenol).the hemodynamic effect of a beta-receptor blockade with mepindolol--a noncardioselective beta-receptor blocker--was studied in 6 male test subjects age 25 to 30 years with an increasing dose of isoproterenol. the cardiac output per min, the heart rate and the stroke volume, the wet blood pressure and the contractility parameters dp/dt max in the right and left ventricles were measured as part of the study. it was found that a dissociated right shift of the dose-effect curves occurred for the str ...1978208993
involvement of camp-dependent protein kinase in the regulation of heart contractile force.the effects of perfusate epinephrine, 1-methyl-3-isobutylxanthine, calcium, and filling pressure were investigated in the perfused working rat heart. epinephrine produced a rapid increase in camp, in the protein kinase activity ratio, and in active phosphorylase. these effects preceded the increase in contractile force produced by the hormone. there was good correlation between protein kinase activation and the increase in force. epinephrine and the phosphodiesterase inhibitor 1-methyl-3-isobuty ...1977196511
left atrial pressure in normotensive and spontaneously hypertensive rats.the left atrial pressure in adult spontaneously hypertensive rats (shr) of the okamoto strain and normotensive control rat (ncr) was measured via chronically implanted catheters. in shr left atrial pressure in end-expiration was more than twice as high (10.3 +/- 0.4 mmhg) as in ncr (4.6 +/- 0.3 mmhg). there was no difference in the intrapleural pressure between the two groups of rats, therefore the enhanced left atrial pressure in shr represents a real rise in the diastolic filling pressure of i ...1979160746
performance of the hypertrophied left ventricle in spontaneously hypertensive rat. effects of changes in preload and afterload.isolated hearts from adult spontaneously hypertensive rats (shr; okamoto 1969), with established hypertension, were investigated in an antegrade perfusion apparatus where preload and afterload could be varied independently. frank-starling curves were constructed at constant afterloads ranging from 50 mmhg to 150 mmhg. as earlier reported, the shr hearts exhibited a rightward shift of their frank-startling relationships compared to those from the normotensive control hearts, though visible only a ...1979160744
fluid exchanges through capillary walls: a modification of the starling hypothesis.in textbooks of physiology it is usually stated that fluids are extravasated from the arterial ends of capillaries, because, there, the outward transmural pressure of the blood exceeds its net inward osmotic pressure. at the venous ends, however, the position is reversed. the fluids are, therefore, reabsorbed. inthis paper it is argued that this is not a true picture of what must really happen. for, having once become equal there is no reason why the pressures should ever cease to be so. instead ...1976958036
left ventricle contractile function in trained dogs with cardial hypertrophy.eight mongrel dogs exercised for 8 weeks by treadmill running at 20 per cent incline 20 to 25 minutes twice daily, 4-5 days/week. another eight dogs which were kept in the cages for a similar period served as controls. the exercise program was effective in inducing myocardial hypertrophy since the ratio left ventricular weight/body weight was significantly (p less than 0.001) higher in the trained dogs (5.04 g/kg) than in the sedentary animals (3.83 g/kg). in morphine-chloralose anesthesia the d ...1976132926
dimensional analysis of the left ventricle: effects of acute aortic regurgitation.the effects of acute severe aortic regurgitation on the left ventricle were investigated in conscious, chronically instrumented dogs. left ventricular dimensions and volumes were measured from biplane cineradiographs of beads positioned near the endocardium. data were collected before and after the production of aortic regurgitation by a catheter technique. the aortic regurgitation resulted in increases in mean aortic pulse pressure from 44 to 73 mmhg (p smaller than 0.001), heart rate from 87 t ...1975123419
the action of histamine on pulmonary vessels of cats and rats.1. the actions of histamine on pulmonary vascular smooth muscle have been studied in isolated cat and rat lungs perfused with blood, lobes of cat lung perfused in vivo and isolated strips of rat, cat and rabbit pulmonary artery. 2. in all the lung preparations histamine caused both dilatation and constriction. in the rat strips it caused both contraction and relaxation. dilatation was only well shown when the vessels were in a prior constricted state. in any one lung dilatation occurred with sma ...1976975628
acute hemodynamic interventions shift the diastolic pressure-volume curve in man.frame-by-frame analysis of angiograms in 16 patients revealed that hemodynamic interventions are capable of producing substantial shifts in the diastolic pressure-volume curve. angiotensin raises blood pressure and shifts the entire pressure-volume curve up, and nitroprusside lowers blood pressure and shifts the curve down. indirect measurements of pleural pressure in seven patients (via esophageal pressure) showed that pleural pressure changes were too small to account for these shifts. analyzi ...1976786501
[the significance of the veins for transcapillary fluid balance].various results from experimental as well as from theoretical studies challenge the classical concept of the starling hypothesis of fluid balance between blood and tissue. although most of these considerations are based on work with animal preparations, the following points appear to be applicable to human physiology: 1. the values of pressure as measured directly in venules, prohibit reabsorption of fluid from the interstitium. in addition, due to the increased permeability of the venular vesse ...19761007836
effects of intraaortic balloon counterpulsation on regional myocardial function during acute coronary occlusion in the dog.the effects of intraaortic counterpulsation on regional myocardial function were studied using ultrasonic dimension gauges in 24 open chest dogs. pairs of ultrasonic crystals were implanted in the subendocardium of the left ventricle in control, marginally ischemic and ischemic segments. after coronary arterial occlusion, the end-diastolic length of all three segments was increased. segment shortening was rapidly replaced by systolic expansion in the ischemic segment. in the marginal segment, ac ...1979758771
effect of gravitational and inertial forces on vertical distribution of pulmonary blood flow.vertical distribution of pulmonary blood flow (vdpbf) was studied, using radioactive microsphere emboli, in dogs without thoracotomy in the right decubitus position during exposure to lateral (--gy) accelerations of 1, 2, 4, and 6 g. at all levels of force environment studied, an inverse linear relationship was observed between vertical height in the thorax and pulmonary blood flow (ml/min/ml lung tissue) with a decrease in flow to the most dependent region of the lung despite large increases in ...1978656003
cardiac function during vagus escape.it is generally believed that the stimulation of vagus nerve has no direct effect on ventricular myocardium. but recent work has demonstrated clear-cut negative inotropic effect of vagal stimulation on ventricles. in an attempt to study further the effect of vagal stimulation on heart, 15 dogs were studied hemodynamically under nembutal anaesthesia. bilateral vagotomy caused 9% elevation of heart rate whereas arterial pressure and cardiac output increased by 5% and 3% respectively. stroke volume ...19751158429
the dependence of the blood to brain passage of radioactive sodium on blood pressure and temperature.brain sodium uptake (bsu) was calculated from estimated radioactivities of brain and blood, collected from rats which were given [24na]sodium chloride 30 min and [22na]sodium chloride 1 min before killing. the calculated bsu values, when plotted against the average blood pressure of the animal during the survival time of 30 min, showed a linear dependence of bsu on blood pressure. in another series of animals, in which in addition to variation of the blood pressure as in the former series, the b ...19751174971
left ventricular dynamics during recovery from exercise.left ventricular dynamics during recovery were measured in dogs, 3 min after brief periods of mild, moderate, and severe treadmill exercise. as compared with resting values, stroke volume was unchanged, and the maximum first derivative of the left ventricular pressure was either unchanged or slightly elevated. increases in heart rate of 20, 26, and 46 beats/min for mild, moderate, and severe exercise appear to be the major factor in augmenting cardiac output during recovery. with moderate and se ...19751176410
[a histochemical and biometric comparison of the long peroneal muscle and its innervation in gallus gallus and coturnix c. japonica].following a previous comparison of the peroneus longus muscle of the quail and the starling, the present paper deals with a comparative study of this muscle in two birds of the order gallinaceae, the quail and the bantam, bearing in mind certain data found in the starling. the study deals with the types of muscle fibres, their frequency in various parts of the muscle, their lipid content and their innervation. in the quail, two types of fibres are found, with a low and high lipid content respect ...19751189892
the effect of saline and hyperoncotic dextran infusion on canine ileal salt and water absorption and regional blood flow.1. the unidirectional na and h2o fluxes, vascular pressures and total and absorptive site blood flows in the canine ileum were determined before and during i.v. saline infusion and subsequent i.v. infusion of hyperoncotic dextran. the intestinal perfusion solutions were isotonic saline or isotonic saline and mannitol, but the effects of i.v. saline or i.v. hyperoncotic dextran infusion were generally the same for both luminal solutions. 2. continuous i.v. infusion of saline caused a continuous i ...19751202200
pressure-flow and volume-flow relationships of the systemic circulation of the dog.mean systemic pressure-flow (ps-q) and volume-flow (v-q) relationships of the systemic vascular bed were determined in two groups of dogs anesthetized with sodium pentobarbital (group i) and with methoxyflurane (group ii). all blood returning to the heart (q) was removed from the right atrial appendage and passed through a starling resistor, a pump, a flowmeter , and then returned directly into the pulmonary artery. ps was estimated from plateau values of right atrial pressure obtained during st ...19751211468
efficiency of the frank-starling mechanism at various levels of inotropy and afterload during aortic insufficiency in the dog.reversible aortic insufficiency was produced in six dogs before and during aortic contrictions at control myocardial inotropy, during high and low inotropy induced by calcium infusion and propranolol administration, respectively. myocardial chord lengths (mcl) of the left ventricular wall were continuously recorded by ultrasonic technique. activation of the frank-starling mechanism during aortic insufficiency was verified by an increase in end-diastolic length and systolic shortening of mcl. eff ...1978653301
functional reductions in left ventricular volume. minimum chamber size consonant with effective hemodynamic performance.a heart model in dogs was developed to evaluate quantitatively the extent to which left ventricular chamber size could be reduced and yet retain residual mechanical function to perform adequately as a pump. in 9 animals placed on right heart bypass perfusion to control systemic flows; left ventricular performance was estimated from high-fidelity left ventricular pressure and aortic flowmeter recordings and from lateral plane left ventricular angiograms. studies were made during unrestricted left ...19761246144
community ecology of helminth parasitism in an insular passerine avifauna.three hundred and thirty specimens of 7 species of passerine birds from south bass island, ottawa county, ohio, were examined for helminth parasites. the total number of helminth specimens collected was 4,333. forty-one helminth taxa were identified. ten species of helminths were identified as having foci of infection on the island. an index of association for these 10 species is presented. the low association revealed between helminth species utilizing common species of intermediate hosts indic ...19761255354
impaired rate of left ventricular filling in idiopathic hypertrophic subaortic stenosis with atrial fibrillation.the external carotid pulse and the phonocardiogram were recorded in a 48-year-old man with idiopathic hypertrophic subaortic stenosis and atrial fibrillation. the degree of obstruction of left ventricular outflow was assessed by the depth of the mid-systolic dip, the length of the left ventricular ejection time and the intensity of the systolic murmur. the correlation found between the degree of outflow obstruction and the length of the preceeding diastole was interpreted in terms of the frank-s ...1979573175
effect of positive end-expiratory pressure on ventricular function in dogs.artificial ventilation with positive end-expiratory pressure (peep) reduces venous return by raising intrathoracic pressure. to determine whether peep decreases cardiac output further by depressing myocardial function, we constructed starling curves, using rapid dextran infusion in 7 anesthetized dogs ventilated with zero (zeep) and 20 cm peep. the changes in stroke volume and in left ventricular stroke work (lvsw) when peep was added or removed were significantly greater than could be attribute ...1979373468
failure of methylprednisolone to protect acutely ischemic myocardium: a contrast with subsequent beta-adrenergic blockade in man.two grams of methylprednisolone was administratered to ten patients with acute myocardial infarction at an average of 13 hours from the onset of symptoms; pain in the chest was not relieved in six of the ten patients. in one hour, no significant improvement was noted in the function of the ischemic segments (examined using a multiaxis echocardiographic method) or in the s-t segments of the 12-lead electrocardiogram. left ventricular filling pressure soon increased by an average of 4 mm hg (p les ...1978348414
cardiovascular 'reactivity' to graded splanchnic nerve stimulation in spontaneously hypertensive and normotensive control rats.cardiovascular 'reactivity' to graded splanchnic nerve stimulation was compared in adult spontaneously hypertensive rats (shr) and normotensive controls (ncr), during abolished adrenal medullary secretion and neurogenic cardiac control and depressed reflex vascular adjustments. arterial pressure, heart rate and cardiac output were measured, and total peripheral resistance (tpr) and stroke volume (sv) computed before, during and after nerve stimulation. the neurogenic resistance increases in the ...1979159600
length-dependent activation: its effect on the length-tension relation in cat ventricular muscle.in cat papillary muscles at 30 degrees c, bathed with tyrode's solution containing 2.25 mm ca2+, the effect of various inotropic interventions (varying the stimulus frequency and continual paired stimulation) on the shape of the steady state length-tension relation was examined at lengths from lmax, where tension production is maximal, to 0.87 lmax. the relative steepness of the length-tension curves for peak tension developed (dt) and for maximum rate of tension development (dt/dt) varied inver ...1977837472
experimental model for systematic study of impaired microvascular reperfusion.a technique is described for reliably producing quantifiable impairment of microvascular reperfusion of the brain after ischemia in dogs. the technique is derived from an analysis of the cerebrospinal fluid compression ischemia model as a starling resistor. it is proposed that this model would be useful in systematic study of post-ischemic impairment of reperfusion.1977847789
[influence of transient and sustained increase of blood pressure on the 1st temporal derivative of the ventricular pressure].to analyze the influence of transient and sustained elevations of arterial pressure (ap) on the rate of rise of the left ventricular pressure (dp/dt).19921340722
left ventricular function during lower body negative pressure.the purpose of this study was to characterize the response of the human left ventricle to lower body negative pressure (lbnp) and to delineate the relation between left ventricular function and hemodynamic response. ventricular function curves relating stroke volume to end-diastolic volum were obtained in 12 normal men. volume data were derived from echocardiographic measurements of left ventricular end-systolic and end-diastolic diameters at rest and during lbnp at -40 mm hg. end-diastolic volu ...1977869837
interaction of transcapillary starling forces in the isolated dog forelimb.three of the four starling forces were measured in the intact dog forelimb after anesthetization and all four of the starling forces were measured in the same forelimb which was surgically isolated yet innervated. in the isolated forelimb, isogravimetric capillary pressure (pci) averaged 15.6 mmhg; colloid osmotic pressure of the plasma proteins (iip) averaged 19.9 mmhg; mean interstitial fluid pressure (pif) was +0.4 mmhg, and the average value of interstitial colloid osmotic pressure (iiif) wa ...1977889604
responses of isolated rabbit thoracic aortae to endothelin-1 and several vasoactive substances. a new blood perfusion circuit under the controlled conditions of resistance and flow.analysis of the reactivity of isolated rabbit thoracic aorta to isoproterenol and norepinephrine injected into a blood perfusion circuit intraarterially (i.a.) under controlled conditions of resistance and flow using conscious support rabbits revealed that with pressure loads of 10-20 mmhg for a vessel-holding chamber and 60 mmhg for a starling pneumatic resistance set, a suitable vasodilation or vasoconstriction can be obtained. this leads us to assume that the system could be used to assess th ...19921392057
effect of hypophosphatemia on myocardial performance in man.severe hypophosphatemia is associated in man with low intracellular stores of atp and a set of specific cellular dysfunctions. to investigate whether hypophosphatemia affects myocardial performance, we measured cardiac output by thermodilution and calculated stroke work in seven patients with severe hypophosphatemia before, during and after repletion with an intravenous potassium phosphate solution. mean left ventricular stroke work for these patients increased from 49.57 to 71.71 g-m per beat ( ...1977904668
dynamics of glomerular ultrafiltration. ix. effects of plasma protein concentration.experiments were carried out on 42 munich-wistar rats with surface glomeruli accessible to micropuncture to investigate the effects of reduction in systemic plasma protein concentration. ca, and thus afferent oncotic pressure, iia, on the determinants of glomerular ultrafiltration. in animals in which ca was reduced by a variety of maneuvers, observed values for single-nephron gfr were lower than values predicted by the starling relation, when the latter were calculated assuming that the observe ...1977835714
measurement of right ventricular volumes using 131i-maa.a method has been presented for determining the right ventricular residual ratio, that is, the ratio of the end-systolic volume to the end-diastolic volume during each cardiac cycle. 131i-maa was injected as a bolus into the right ventricle, and the ratio of isotope remaining in the chamber during the succeeding cardiac cycles was determined with a collimated scintillation counter placed over the right ventricle. since the counter detected the radioactivity from the entire right ventricular cavi ...19751090136
[acute reduction of uterine blood flow and fetal heart rate changes in pregnant sheep near term].five merino sheep near term were used for acute preparations to investigate the influence of basal uterine blood flow (ubf), basal fetal oxygenation and basal fetal heart rate (fhr) on fhr changes elicited by acute reduction of ubf. the ewes were anaesthesized with pentobarbital and alloferin was given for relaxation. ventilation was maintained via a tracheal tube by a starling pump. maternal heart rate, arterial pressure and intrauterine pressure as well as fetal heart rate and umbilical artery ...1977870676
mechanical determinants of myocardial oxygen consumption with special reference to external work and efficiency.the aim of the study was to investigate the ambiguous effect of left ventricular afterload on myocardial work, oxygen consumption, and efficiency.19921451165
diastolic vibration improves systolic function in cases of incomplete relaxation.incomplete relaxation of the left ventricle (lv) affects lv filling, but the subsequent effect on lv systolic function remains unclear. we attempted to improve relaxation by applying oscillatory mechanical perturbation during diastole (diastolic vibration) and examined the extent to which systolic function improved.19921451267
intrapulmonary co2 receptors in the duck: iv. discharge pattern of the population during a respiratory cycle.we used single-unit vagal recordings to study the average discharge pattern during a respiratory cycle from 57 intrapulmonary co2 receptors in 6 ducks artificially ventilated with a starling pump. peak discharge frequency occurred during inspiration in 51%, expiration in 19%, and both inspiration and expiration in 30% of the receptors. average discharge frequency from all receptors was maximum at mid-inspiration, but frequency also increased slightly during early expiration. the results suggest ...1976935700
frank-starling relationship as an important determinant of fetal cardiac output.the importance of the frank-starling mechanism was evaluated in seven chronically instrumented fetal lambs (128-141 days gestation). continuous determinations of left ventricular (lv) internal dimensions and pressures were obtained while lv end-diastolic diameter (lvedd) was reduced by superior vena cava occlusion and increased by infusion of fetal blood into left atrium. a highly significant relationship was found to exist between stroke volume and lv extent of shortening (delta d) (r = + 0.99, ...1976961903
the concept of afterload mismatch and its implications in the clinical assessment of cardiac contractility.the characteristics of left ventricular ejection (velocity and extent of wall shortening) can be analysed in relation to the appropriateness of the matching between afterload and the level of inotropic state (contractility), as modified by the preload (frank-starling) reserve. in the normal left ventricle if the preload is not allowed to compensate for an acute increase in afterload, or if the limit of preload reserve is reached, velocity (v cf) and stroke volume will diminish; that is an afterl ...1976966366
auditory perception of conspecific and heterospecific vocalizations in birds: evidence for special processes.budgerigars (melopsittacus undulatus), canaries (serinus canaria), and zebra finches (poephila guttata castanotis) were tested for their ability to discriminate among distance calls of each species. for comparison, starlings (sturnus vulgaris) were tested on the same sounds. response latencies to detect a change in a repeating background of sound were taken as a measure of the perceptual similarity among calls. all 4 species showed clear evidence of 3 perceptual categories corresponding to the c ...19921555398
ischemia-induced depressed systolic thickening is transiently augmented by remote coronary occlusion.to determine if ischemia-induced depressed myocardial thickening can be augmented by remote coronary occlusion, posterior wall function (pulsed doppler crystal) was measured before and after left anterior descending coronary artery occlusion in the presence of reduced circumflex coronary artery flow (of sufficient severity to reduce resting function) in an anesthetized open-chest canine preparation in which the circumflex was pump-perfused with carotid arterial blood. left anterior descending co ...19921571984
estimation of total body fluid shifts between plasma and interstitium in man during extracorporeal circulation.fluid transport between plasma and interstitium during extracorporeal circulation was studied in seven patients undergoing aortocoronary bypass grafting. the absolute shifts in plasma volume during hypothermia were determined as the difference between input and loss of fluid and the changes in blood volume. the change in haemoglobin concentration due to acute haemodilution when starting extracorporeal circulation was used to calculate the absolute blood and plasma volume. the starling equation f ...19921574974
the cardiodynamic and metabolic effects of glucagon.the cardiac effects of a continuous infusion of glucagon at the rate of 10 mug/min were studied in the starling heart-lung preparation, modified to measure coronary flow and myocardial oxygen consumption. a maximal increase in myocardial contractility, as reflected by maximal rate of rise of left ventricular pressure, dp/dt, of 31% was observed at a total dose of glucagon of 50 mug and was accompanied by an increase in heart rate and in myocardial oxygen consumption of 59% and 57%, respectively. ...19761004638
single perturbed beat vs. steady-state beats for assessing systolic function in the isolated heart.single-beat and steady-state techniques for evaluating end-systolic pressure-volume relationship (espvr) and frank-starling mechanism (fsm) in the crystalloid-perfused isolated rabbit heart were compared. in the single-beat technique, a train of stable isovolumic beats was interrupted with a single perturbed beat that either ejected against various levels of imposed isobaric load (espvr protocol) or beat isovolumically against various levels of end-diastolic volume (v(ed); fsm protocol). in stea ...19921621824
lymphatic versus nonlymphatic fluid absorption from the peritoneal cavity as related to the peritoneal ultrafiltration capacity and sieving properties.in this article we discuss the role of capillary fluid absorption via starling mechanisms (the transcapillary hydrostatic pressure gradient opposed by the colloid osmotic pressure gradient as multiplied by the capillary uf coefficient) vs. lymphatic fluid absorption as determinants of the total fluid loss from the peritoneal cavity during continuous ambulatory peritoneal dialysis (capd). we also mention that, under nonsteady state conditions, there is in addition some net absorption of fluid int ...19921308683
cardiac muscle models for both isotonic and isometric contractions.the choice of a suitable muscle model consistent with the mechanical behaviour of rat papillary muscle at rest or during isotonic or isometric contraction has been considered. three different preload levels within the ascending limb of the frank-starling curve have been used in five papillary muscles. series elastic (se) and parallel elastic (pe) length-tension relationships have been evaluated according to five mechanical muscle models using data from systolic and diastolic quick-release manoeu ...19751239734
capillary filtration measurement by strain gauge. i. analysis of methods.the strain-gauge method for measuring changes in limb size, introduced by whitney in 1953 has not received wide usage for measurement of capillary filtration coefficient (cfc). this method was compared for the dog hindlimb to simultaneous measurements by the classic gfavimetric technique and was found to give comparable results. the larger question of whether either method gives useful information about the true cfc of the limb was addressed by a mathematical analysis of the technique combined w ...1977851198
modification of the flow-generating capability of the canine heart-lung compartment by the carotid sinus baroreceptor reflex.to quantitatively understand how the carotid sinus baroreceptor reflex modifies the starling curve (i.e., the aortic flow (af)-mean right atrial pressure (mrap) relationship), experiments were performed in closed-chest, naturally breathing, and anesthetized dogs before and after vagotomy. mean aortic pressure (map) was fixed at approximately 100 mm hg and the pressure in the isolated carotid sinus (isp) was varied from 75 to 150 mm hg in steps of 25 mm hg. at each isp, mrap was slowly increased ...19761269105
capillary filtration measurement by strain gauge. ii. effects of mannitol infusion.maintenance of normal partition of extracellular fluid into vascular and interstitial compartments is a tightly controlled system. one means of studying control of this system is to induce filtration by fluid loading, and to measure associated changes capillary filtration coefficients (cfc) and starling pressures in a particular vascular bed. we therefore measured responses of the dog hindlimb to isotonic mannitol infusions. using strain-gauge plethysmography to measure cfc, the johnson zero-flo ...1977851199
a two-dimensional morphometry-based model of interstitial and transcapillary flow in rabbit synovium.the synovial lining of a joint is a layer of specialized connective tissue, containing fenestrated capillaries, that regulates the volume and composition of fluid in the joint cavity. the hydraulic conductance of the synovial lining and of the plasma-to-cavity pathway is increased by high intra-articular pressures (iap greater than 9 cmh2o) and this is accompanied by an increase in the interstitial pathway's area/pathlength ratio. in order to assess the contribution of the altered pathway geomet ...19911768416
quantitative assessment of cardiac pump performance.1. a means of quantitating left ventricular performance in the conscious dog is presented. changes in heart rate, stroke volume and cardiac output during elevation of left atrial pressure by acute volume expansion were measured in the conscious dog. 2. the changes in heart rate and stroke volume could be described by y = ym - (ym-yi)e-kp, where yi and ym are initial and maximum values of the variable and p is the change in mean left atrial pressure. 3. because cardiac output is a derived variabl ...1977894597
starling forces and lymphatic drainage in pleural liquid and protein exchanges.pleural liquid volume and protein concentration (c) were determined in rabbits 60 min after a 2 ml hydrothorax with various albumin concentrations in ringer, homologous serum or plasma. the absorption rate of the hydrothorax decreased with the increase in colloid osmotic pressure of the pleural liquid (pi), being 0.56 +/- 0.03, 0.32 +/- 0.02 and 0.17 +/- 0.05 ml/h with ringer, 1.1 and 3 g% albumin, respectively, and nil with 5% albumin, serum or plasma. c increased with ringer and 1.1% albumin, ...19911780605
nationwide residues of organochlorines in starlings, 1974.organochlorine residues in starlings (sturnus vulgaris) from 126 collection sites were monitored during the fall of 1974. dde, ddt, polychlorinated biphenyls (pcb's), and benzene hexachloride were present in all samples. dieldrin, heptachlor expoxide, hexachlorobenzene, and oxychlordane were present in approximately 97% of the samples. dde, dieldrin, and pcb residues in starlings were significantly lower than they had been in 1972.1976940731
renal sodium retention in the nephrotic syndrome.where do the experiments on rat kidneys exposed to puromycin leave us in attempting to evaluate further the pathophysiology of oedema in human nephrotic syndrome? they cannot be considered conclusive. the arguments favouring an intrinsic abnormality in the kidney as a major factor in sodium retention, rather than this being a secondary response to humoral and neural influences stimulated by changes in actual or perceived plasma volume, would be strengthened by experiments using another animal mo ...19911818554
[turdus merula l. as a proper host of capillaria ovopunctata (nematoda, capillariidae)].biometrical analysis of four morphometric characters of male and female specimens of capillaria ovopunctata parasitizing in sturnus vulgaris, erithacus rubecula, turdus philomelos and turdus merula, i.e. length of body, oesophagus, number of stichocytes or length of spicula and vulvar appendage respectively was carried out. it has been proved, that characters of females c. ovopunctata parasitizing in t. merula significantly differ from those of the nematodes found in other hosts. the present and ...19911822042
hemodynamic effects of staged hematocrit reduction in patients with stable cor pulmonale and severely elevated hematocrit levels.patients with cor pulmonale and high hematocrit levels are often subjected to phlebotomy in the belief that the adverse effects of high viscosity may outweigh the benefit of increased oxygen carrying capacity. to evaluate this, 12 patients with stable cor pulmonale and hematocrit values greater than 55 per cent were studied before and after a series of venesections. right heart and aortic pressures, cardiac output and blood gases were measured at three mean hematocrit levels, 61 per cent (stage ...19751115064
absence of fetal placental waterfall phenomenon in chronically prepared fetal lambs.an electromagnetic flow sensor was placed on the distal fetal aorta (umbilical flow fraction 78.1 +/- 1.6 sem, %), an inflatable occluder was tied around the umbilical cord, and catheters were placed in distal branches of an umbilical artery and vein, a uterine vein, and in the amniotic cavity. an inflatalbe occluder was tied around the vagina of some of the ewes. control values 3 days after surgery were (mean +/- se): fetal femoral artery ph, 7.37 +/- 0.01; umbilical blood flow, 186 +/- 14 ml-m ...19761267019
responses of slowly and rapidly adapting receptors in the airways of rabbits to changes in the starling forces.1. the responses of the rapidly adapting receptors (rars) and the slowly adapting receptors (sars) of the airways to changes in the starling forces regulating fluid exchange in the pulmonary extravascular space were investigated in anaesthetized rabbits. the hydrostatic pressure in the pulmonary microvasculature was raised by partial obstruction of the mitral valve (mean left atrial pressure increased by approximately 5 and 10 mmhg above the control values) and the concentration of plasma protei ...19911886073
effect of afterload and beta-adrenergic blockade on nonischemic myocardial contraction pattern.we studied how changes in afterload affect regional contraction in the anterior wall of the left ventricular after circumflex coronary arterial (cfx) occlusion and subsequent beta-adrenergic blockade in pentobarbital sodium-anesthetized cats. regional function was determined by orthogonal sonomicrometry. cfx occlusion produced nonuniform hyperkinesis in the nonischemic anterior wall; shortening of circumferential segments increased from 10.1 to 14.1% (p < 0.001), whereas shortening of longitudin ...19921362331
effect of dexmedetomidine, an alpha 2-adrenergic agonist, in the isolated heart.dexmedetomidine (dm) was studied in the isolated dog heart in the form of a starling heart-lung preparation, (hlp). hearts were subjected to increased loading by (a) increasing cardiac output, and (b) increasing systemic resistance. results are depicted by cardiac function curves, prepared by plotting left atrial pressure against either systemic cardiac output or mean arterial pressure. dm, given in divided doses up to 44 micrograms, had no effect on heart rate or cardiac function, nor did injec ...19921353991
acute lowering of plasma oncotic pressure increases filtration fraction and sodium excretion in conscious sheep.we examined the effect of acutely lowering the colloid osmotic pressure by removing plasma (36.2 +/- 3.1 ml/kg) and replacing it with hartmann's solution (93.0 +/- 8.2 ml/kg) in 6 conscious merino sheep. the colloid osmotic pressure was reduced significantly (p < 0.05) from 20.3 +/- 0.9 to 8.5 +/- 2.5 mm hg 0 h after plasmapheresis and to 15.2 +/- 0.8 mm hg 20 h after treatment. the filtration fraction increased from 0.16 +/- 0.02 to 0.27 +/- 0.02 at 0 h (p < 0.05 vs. control) and to 0.20 +/- 0. ...19921282727
regional contractile performance during acute ischemia in porcine right ventricle.studies of regional ischemia in the canine left ventricle (lv) have shown augmented systolic segmental shortening in nonischemic regions. to characterize these responses in the right ventricle (rv), acute occlusions of the right coronary artery (rcao) were produced in anesthetized pigs. orthogonal pairs of ultrasonic segment-length crystals were implanted in the mid-rv free wall (ischemic region) and in the outflow tract (nonischemic region). rv pressure-area work loops were generated during inf ...19921636753
changes in pericardial pressure during the perinatal period.to determine how the tissues that surround the heart affect diastolic and systolic function during the perinatal period, we studied the pressure-diameter relation of the left ventricle in partially delivered fetal lambs.19921423972
left ventricular hypertrophy: dissociation of structural and functional effects by therapy.the heart is one of the major target organs that becomes secondarily involved with the unrelenting and progressive vascular disease of essential hypertension. as a result of this increasing afterload that is imposed upon the left ventricle, the ventricular chamber adapts structurally and functionally. structural changes involve an increase in muscle mass that is achieved through left ventricular hypertrophy (in a manner similar to the arteriolar changes demonstrated by increased thickening). unl ...19911839347
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