SEARCH · Search PubMed

Results for “Cross Circulation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources

PubMed1978

Microlymphangiographic study of lymphatic regeneration following intestinal anastomosis.

Using a technique of intestinal microlymphangiography, the canine intestinal lymphatic system was studied. Appearance of a two dimentional network above the muscularis mucosa layer was found to be characteristic. A study of the lymphatic regeneration pattern of the intestinal anastomosis showed a cross circulation through newly reconstructed lymphatics to commence on the seventh postoperative day and to be completed by the 21st day.

Animals↗

PubMed1979

Biochemical, hematological and histological changes in a fulminant hepatic failure rat model for artificial liver assessment.

Galactosamine-induced fulminant hepatic failure rats have been used as a model for statistical assessment of liver support systems. The present study reports in detail the biochemical, hematological and histological changes in these animals. They have been used to study statistically the effects of ACAC charcoal hemoperfusion, cross-circulation and liver perfusion on long-term survival in fulminant hepatic failure.

Animals↗

PubMed1976

Afferent neural pathway in the regulation of cardiopulmonary responses to tissue hypermetabolism.

We studied the role of neural transmission from hypermetabolic peripheral tissues in the regulation of cardiac output and pulmonary ventilation in chloralose-anesthetized dogs. Cross-circulation techniques with femoral-femoral or femoral-aortic anastomoses were used to produce a vascularly isolated, but normally innervated, hindlimb or lower half-body, 2,4-Dinitrophenol (DNP) was infused into the arterial side of the perfusion circuit to triple oxygen consumption and to increase lactate production by the cross-perfused area. After infusion of DNP, cardiac output and mean systemic arterial blood pressure increased, but neither heart rate nor pulmonary artery wedge pressure changed significantly. Pulmonary minute ventilation and arterial pH also increased, while arterial PCO2 fell. These changes were abolished when the nerve connections between the perfused limb and its parent body were severed. Normal saline, when administered in a similar manner, did not increase either ventilation or cardiac output, and simple denervation without previous infusions of DNP also had no effect. These results indicate that there are receptors sensitive to metabolic changes in the tissue, and that neural transmission is an important afferent link in regulating the cardiopulmonary responses to increased tissue metabolism.

Afferent Pathways↗

PubMed1999

C. Walton and F. John.

This paper is a brief biography of two of the most important contributors to the development of open heart surgery. In 1952, John Lewis performed the first successful open heart surgical procedure of any kind, repairing an atrial septal defect under general hypothermia in a 5-year-old girl. In March 1954, Walt Lillehei, utilizing controlled cross circulation, embarked on a series of 45 consecutive patients. The bubble oxygenator appeared in 1955, and open heart surgery was introduced to many of this nation's major medical centers.

Cardiac Surgical Procedures↗

PubMed1991

Humoral factors and hemodynamics during cross-clamping of the thoracic aorta.

The present study was designed to test the hypothesis that vasoactive compounds produced in the ischemic part of the body below an occluded aorta are responsible for the hemodynamic changes observed during cross-clamping of the thoracic aorta. The experiments were performed on 32 rabbits anesthetized with halothane that underwent experiments with cross-circulation; the blood from the inferior caval veins of rabbits A was pumped into the inferior caval veins of rabbits B. Simultaneously, exactly the same amount of blood was pumped from the jugular vein of rabbits B into the jugular vein of rabbits A. The aorta and inferior vena cava were exposed and then simultaneously cross-clamped directly below the diaphragm. The cross-clamping of the aorta and inferior vena cava in rabbits A was associated with a 29% to 44% increase in mean arterial pressure in rabbits B. The experiments support the hypothesis and suggest that endogenously produced humoral factors are responsible for at least one third to one half of the arterial hypertension that usually develops during aortic cross-clamping.

Anesthesia, Inhalation↗

PubMed1993

Partial purification and characterization of a circulating hypertensive factor in spontaneously hypertensive rats.

Parabiosis and cross-circulation experiments with spontaneously hypertensive and normotensive rats gave indications for a previously unidentified circulating hypertensive agent. In this study, plasma from normotensive and hypertensive rats was fractionated and the vasopressor action of the corresponding fractions was measured in the isolated perfused rat kidney. One of three vasoactive fractions obtained by gel filtration (Biol-Gel P2) from hypertensive rats showed a significantly higher activity (increase in perfusion pressure by 1502.9 +/- 438.9 Pa) than that from normotensive rats (increase in perfusion pressure by 505.4 +/- 186.2 Pa, P < 0.01). Further chromatographic separations of this fraction revealed that the hypertensive factor is hydrophilic and has no ionic groups or vicinal diol groups. The molecular mass was estimated by dialysis and the matrix-assisted laser desorption/ionization mass spectrometry to be in the range of 1 kDa. The vasopressor is heat resistant and not degradable with trypsin or carboxypeptidase Y. The vasopressor action was not inhibited with the angiotensin-II-receptor antagonist saralasin, the alpha-receptor antagonist phentolamine, the thromboxane-receptor antagonist carbocyclic thromboxane A2 or the serotonin antagonist ketanserin. The results confirm the existence of a vasopressor factor in the plasma of hypertensive rats and, in a lower concentration, of normotensive rats, which is possibly related to the pathogenesis of essential hypertension. The chromatographic behavior suggests that this factor is different from the parathyroid hypertensive factor described recently.

Animals↗

PubMed1989

Reduction of highly elevated plasma levels of gamma-aminobutyric acid does not reverse hepatic coma.

The pathogenesis of coma in patients with fulminant hepatic failure is still unknown, but there is some evidence that decreased hepatic metabolism of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) may be involved. If this hypothesis is true, reduction of increased GABA levels in patients with hepatic encephalopathy should reduce the depth of hepatic coma. In the case described here, highly elevated plasma GABA levels were reduced by cross-circulation with baboon liver. No amelioration of the coma was observed, thus suggesting that decreased hepatic metabolism of GABA is not critically involved in hepatic encephalopathy.

Adult↗

PubMed1980

Sequential scintiangiography of the hepato-splenic system of xiphopagus conjoined twins.

Scintiangiography of xiphopagus conjoined twins following sequential i.v. injection of Tc-99m sulfur colloid revealed the size, configuration, and anatomic point of fusion of the twins' common liver prior to surgery. Cross circulation was determined to be non-significant by this approach. The technique is presented, compared to other methods, and the benefit of sequential hepatic scintiangiography for xiphopagus conjoined twins is reviewed.

Cross Circulation↗

PubMed1959

The central action of lignocaine and its effect on cardiac output.

Fifty-nine tests were performed on twenty-four anaesthetized dogs in a study of the effects of lignocaine on circulatory and respiratory functions. In single-dog experiments, it was shown that lignocaine (1 to 2 mg./kg. body weight) increased ventilation somewhat, but had no effect on O(2) consumption. Cardiac output was increased due to a rise in both heart rate and stroke volume. There was an elevation of arterial blood pressure. The central blood volume was increased, but central venous pressure, total peripheral resistance and the ventilationperfusion ratio were decreased. The increase in cardiac output after lignocaine was abolished both in decerebrate and in vagotomized dogs. In cross-circulation experiments with dogs, it was demonstrated that the primary site of action of lignocaine on cardiac output was central. The effect of lignocaine on cardiac output could be blocked by intravenous procaine.

Animals↗

PubMed1981

Circulating hepatodepressant factors decreasing the energy charge levels of the remnant liver after hepatectomy.

In 25% hepatectomized rabbits, the mitochondrial phosphorylative activity and the energy charge [(ATP + 1/2 ADP)/(ATP + ADP + AMP)] levels of the remnant liver remained unchanged after hepatectomy. In 70% hepatectomized rabbits, the energy charge levels of the remnant liver decreased maximally 24 h after hepatectomy (p less than 0.001), simultaneously with a marked enhancement of mitochondrial phosphorylative activity (P less than 0.001). Afterward, both returned to normal levels within 4 days. In 93% hepatectomized rabbits, the energy charge levels fell rapidly, with an inhibition of mitochondrial phosphorylative activity, within 6 h after hepatectomy. When a 24-hour 70% hepatectomized rabbit was cross-circulated with a normal rabbit, the energy charge in the liver of the normal partner decreased to 0.732 at 30 min after the blood exchange and then returned to 0.855 while that in the remnant liver of the hepatectomized partner increased from 0.767 to 0.820 (p less than 0.001). Also, the energy charge values of a 24-hour 70% hepatectomized rabbit were increased by the extracorporeal normal liver perfusion. It is suggested that a decrease in the energy charge of the remnant liver is due, at least partly, to the accumulation of the substances consuming hepatic energy (hepatodepressant factors) in the systemic blood of hepatectomized rabbits.

Adenine Nucleotides↗

PubMed2000

Establishment of a parabiotic rat model by anastomosis of common carotid artery.

A cross circulation model was established by replacing mutual blood between two rats by anastomoses of each common carotid artery. In this model, parabiotic rats were shown to replace their mutual blood completely without any artificial materials or instruments, such as silicon tubes or pumps. The rate of blood exchange was measured by intravenous injection of Evans blue dye without the use of the radioactive materials that were so far commonly used. The partial alteration of blood circulation through microvascular surgery may reveal the mechanisms of organ tropism of bacteria, protozoa, and parasites. Microvascular surgery is available for reconstruction and analysis of organ functions as well as for clinical use in organplasty.

Anastomosis, Surgical↗

PubMed1975

Mechanisms of oral staphylococcal enterotoxin B-induced emesis in the monkey (38553).

Vomition is the most consistent response to oral SEB challenge in the monkey. The technique of cross-circulation clearly differentiates local neural phenomenon from humoral mechanisms. Our results support the theory that SED-induced vomition follows stimulation of local neural receptors in the gut. The evidence indicates no significant amount of enterotoxin absorption or stimulation of vomition by any centrally acting humoral mechanism.

Administration, Oral↗

PubMed1976

Alterations of the Frank orthogonal scalar leads induced by anaphylactic shock in the rabbit.

The anaphylactic shock of the rabbit is characterized by an acute right ventricular overload, accompanied by severe alterations of cardiac electrogenesis. During shock, the mean QRS vector, as measured from the algebraic sum of the Q, R, and S deflections on the three leads, shifts to the right, inferiorly and anteriorly. An injury current quickly appears. The TQ vector points away from the right ventricle. A progressive depolarization on the right ventricular wall is displayed by suction electrodes and the suppression of right ventricular hypertension by a cross circulation produces an almost immediate disappearance of the injury current. The geneses of these electrical alterations are briefly discussed. The possibility of an anaphylactic reaction at the level of the coronary arterial wall, previously mentioned in the literature, seems unlikely. The role of the haemodynamic changes and of the increased right ventricular blood pool is thought to be predominant.

Action Potentials↗

PubMedDate not supplied

Centrally mediated hypocholesterolaemic response of insulin in dogs.

Insulin on intravenous administration in dogs caused a rise in blood cholesterol level. This may be due to its direct action on liver or other peripheral structures. On the other hand, insulin administered into the lateral cerebral ventricles in normal as well as in spinal and vagotomized dogs resulted in a lowering of blood cholesterol. In cross circulation studies insulin administered into lateral cerebral ventricles of donor dogs produced a hypocholesterolaemia in the recepient dogs without significant changes in blood cholesterol of donor dogs. It is suggested that some substance may be liberated from some parts of central nervous system due to an action of centrally administered insulin. This substance in turn causes hypocholesterolaemia by acting on liver or some other peripheral structures in dogs.

Animals↗

PubMed1978

Humorally mediated alterations in cardiac performance as a consequence of positive end-expiratory pressure.

Two experimental designs were used to study the mechanism of the decreased cardiac output associated with the use of positive end-expiratory pressure (PEEP). In the first study of nine dogs the application of 15 cm H2O PEEP led to a decrease in cardiac output (CO) from 2.68 +/- 1.05 to 2.01 +/- 1.26 liters/min (+/- SD) (p less than 0.05) concomitant with an increase in transmural central venous pressure of 5.2 +/- 0.9 to 8.4 +/- 2.7 mm Hg (p less than 0.05) and a slight increase in transmural left atrial pressure of 6.8 +/- 3.3 to 7.3 +/- 3.6 mm Hg (p less than 0.1). These data are consistent with altered ventricular performance. In a second study nine pairs of dogs were cross-circulated. Application of 15 cm H2O PEEP to one member of the experimental pair led to a decrease in the CO of the other member from 2.71 +/- 0.98 to 2.21 +/- 0.81 liters/min (p less than 0.001). This decrease returned toward baseline with the removal of PEEP (p less than 0.02). Results indicate that one mechanism whereby PEEP reduces the cardiac output is through the action of a humoral agent.

Animals↗

PubMed1993

Left ventricular ORS widening decreases Emax without lowering VO2-PVA relation in dog hearts.

We observed a few rare spontaneous cases of a suddenly widened QRS wave of left ventricular ECG associated with a simultaneous decrease in left ventricular (LV) contractility (Emax, end-systolic pressure-volume ratio) in excised cross-circulated dog heart experiments. The decreased Emax was not associated with a descent of the relation between cardiac oxygen consumption (VO2) and LV systolic pressure-volume area (PVA, a measure of total ventricular mechanical energy). This result is intriguing because ventricular VO2-PVA relation generally changes its elevation in proportion to Emax under various inotropic interventions. We suspected the unusual observation to reflect no change in myocardial contractility despite ventricular asynchrony augmented by an intraventricular conduction defect.

Animals↗

PubMed1975

Chimeric analysis of hemopoietic cells after cross-sex parabiosis.

Anemia or polycythemia was induced in male rats. These males were conjugated with healthy, untreated female litter mates by FANG'S method of aortic parabiosis that resulted in complete cross circulation of blood between the two animals. The sex chromosomes of cells in erythropoiesis in various hemopoietic organs were examined in the treated male animals. The anemic parabionts indicated sharp increases in chimerical rates with erythroid marrows being evident. Polycythemic parabionts indicated marked decreases in chimerical rates with evidence of myeloid marrows. These findings suggested that the so-called stem cells in peripheral blood of the female parabiont migrated to the bone marrow of the male partner and that these migrating cells differentiated to erythroblast. The possible relationships between erythropoiesis and other cell proliferations in the hemopoietic organs are discussed.

Anemia↗

PubMed1977

Nonexcised papillary muscle preparation: force and length measurement and control.

An electromechanical servocontrol system was developed to analyze mechanical properties of a nonexcised, blood-perfused papillary muscle. A miniature load cell mounted on the moving arm of a pen motor measured muscle force, and a shaft angle sensor built in the motor measured the length. The pen motor was actuated by a servocontrol command signal. A papillary muscle was exposed in the right ventricle of an excised, cross-circulated canine heart. The tendinous end of the papillary muscle was connected to the load cell. The intact root of the muscle was fixed by a metal ring. The preparation was stable over 5 h heating at a regular spontaneous heart rate (95-150/min) at 37 degrees C. The system allowed the muscle to contract in various modes such as isometric, isotonic, auxotonic, afterloaded isotonic, quick released, lengthening, etc. Changes in the contraction mode, preload, and afterload could be achieved at the investigator's disposal simply by turning switches and potentiometers, or by feeding external command signals of desired wave forms.

Animals↗