Experimental retrograde cerebral perfusion via bilateral maxillary vein in dogs.
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Animals↗
Biomedical subjects
M Onoe
Publications and source records attributed to M Onoe.
Clinical significance of reverse redistribution phenomenon after coronary artery bypass grafting.
The reverse redistribution (RR) phenomenon is a decrease in thallium 201 uptake during redistribution compared with 201Tl uptake immediately after exercise. We evaluated RR in 23 patients after coronary artery bypass grafting. Postoperative RR was present in 48% and was significantly more common in patients with a history of myocardial infarction (62%). The patients were classified according to the presence (+) or absence (-) of RR. An analysis of left ventricular wall motion showed significant improvement after coronary artery bypass grafting in the RR+ group (n = 12) but not in the RR- group (n = 11). Quantitative myocardial viability was evaluated using the defect volume ratio, mean defect severity, and defect severity index. The preoperative defect volume ratio was higher in the RR+ group than in the RR- group (p < 0.05). In the RR- group, no improvement in these indices was observed after operation. In contrast, the RR+ group showed significant improvement in all three indices (p < 0.05). These results indicate that after coronary artery bypass grafting, an adequate blood supply to the remaining myocardium may induce RR. This phenomenon, therefore, may be a significant indicator of postoperative myocardial viability.
Adult↗
Effects of auricular stimulation on feeding-related hypothalamic neuronal activity in normal and obese rats.
It is known that auriculotherapy occasionally affects dramatic body weight reduction for obese patients, although the physiological and anorexigenic functions are not clear. Effects of auricular stimulation on feeding-related lateral (LHA) and ventromedial (VMH) hypothalamic neuronal activity in normal and experimental (hypothalamic and dietary) obese rats were investigated. The LHA and/or VMH neuronal activity were recorded from feeding-related regions in Wistar SPF/VAF male and experimental (hypothalamic and dietary) obese rats, anesthetized with urethane-chloralose, under stereotaxic coordination. Recording was through 3 M KCI glass microelectrodes, while stimulating the ipsilateral vagal innervated region of the auricle. This is equivalent to the cavum conchae in the human, and was identified by resistance less than 10-50 k omega. The stimulating electrode was a stainless steel ear acupuncture (0.12 x 2.0 mm). The latency of potentials evoked in the LHA by unilateral stimulation of a specific site in the ear was 28.1 +/- 3.3 ms (8-92, n = 41). LHA neuronal activity was depressed 45.6% (n = 12, p < 0.01), and VMH activity was excited (60.5%, n = 18, p < 0.01). The auricular acupuncture stimulation clearly modulates feeding-related hypothalamic neuronal activity of experimental (both hypothalamic and dietary) obese rats. These auricle acupuncture stimulation effects were correlated to the degree of obesity. In conclusion, the results suggest that auricular acupuncture stimulation may not reduce appetite, but is more likely concerned with satiation formation and preservation. Thus, auricular acupuncture should be more effective on obese rats than on normal rats.
Acupuncture Therapy↗
Surgical repair of a ventricular septal defect in a patient with trisomy 8 syndrome.
We surgically repaired a ventricular septal defect (-VSD) in a patient with trisomy 8 syndrome. This case illustrated a number of characteristic clinical features associated with trisomy 8 syndrome patients which have previously been reported in the literature. However, our patient's VSD was not found to be particularly different from the VSD of patients without chromosomal abnormalities during either the surgery or the postoperative course.
Child, Preschool↗
Bilateral main bronchial compression caused by the ductal ligament.
Several authors have reported cases of respiratory distress resulting from bronchial compression due to a hypertensive pulmonary artery in the setting of a large left-to-right shunt. However, respiratory distress due to bilateral main bronchial compression due to an enlarged pulmonary artery suspended posteriorly by the ductal ligament following repair of a ventricular septal defect is extremely rare. In this report, we advocate the necessity of dividing the ductal ligament in some patients with large left-to-right shunts when there are episodes of idiopathic respiratory distress before operation.
Airway Obstruction↗
Optimal perfusion pressure for experimental retrograde cerebral perfusion.
We evaluated cerebral metabolism during retrograde cerebral perfusion (RCP) and circulatory arrest during profound hypothermia, and also investigated the effects of perfusion pressure on RCP. Twenty-four adult mongrel dogs were placed on cardiopulmonary bypass and cooled to a nasopharyngeal temperature of 20 degrees C. At this temperature, hypothermic circulatory arrest (HCA; n = 6), and RCP with a perfusion pressure of 10 mmHg (RCP10; n = 6), 20 mmHg (RCP20; n = 6), and 30 mmHg (RCP30; n = 6) were carried out for 60 minutes. RCP was performed with oxygenated blood via the bilateral maxillary veins, and the retrograde flow rate was regulated to maintain a mean perfusion pressure of 10, 20, or 30 mmHg in the external jugular vein. At 60 minutes of RCP, we measured nasopharyngeal temperature; regional cerebral blood flow (rCBF); cerebral oxygen consumption, carbon dioxide excretion, and excess lactate; cerebral tissue adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and energy charge; and cerebral tissue water content. In the RCP10 group, there was excess cerebral lactate, and ATP and energy charge were low. In the RCP30 group, the water content of cerebral tissue was significantly higher than in other groups. In the RCP20 group, temperature was maintained in a narrow range, oxygen consumption and carbon dioxide excretion could be observed, there was no excess lactate, and ATP and energy charge were significantly higher than in the HCA group. In conclusion, RCP can provide adequate metabolic support for the brain during circulatory arrest, and a perfusion pressure of 20 mmHg is most appropriate for RCP.
Animals↗
A clinical study on the effects of pulsatile cardiopulmonary bypass on the blood endotoxin levels.
Levels of endogenous endotoxins have been reported to increase after cardiopulmonary bypass. Endotoxin levels have also been implicated in multiple organ failure and may contribute to the immunocompromised state seen after bypass. We evaluated the effects of pulsatile cardiopulmonary bypass circulation on endogenous endotoxin levels. The study population consisted of 15 consecutive adult patients who underwent cardiac operations with cardiopulmonary bypass. Pulsatile flow was used during aortic crossclamping in eight patients (group I) and nonpulsatile flow was used in the remaining seven patients (group II). Changes in blood endotoxin levels were monitored during aortic crossclamping, after release of the clamp, and after weaning from bypass. The blood endotoxin level at each stage was expressed as a percentage of the level at the beginning of bypass. Group I patients a significantly lower blood endotoxin percentage than group II (from 20 to 120 minutes after the initiation of aortic crossclamping). In group I, the blood endotoxin percentage was nearly constant during aortic crossclamping. After release of aortic crossclamping, group I also had a lower blood endotoxin percentage than group II. Endogenous endotoxin levels appear to increase in the presence of intestinal congestion and ischemia. Improvement in intestinal circulation by pulsatile cardiopulmonary bypass may prevent increases in endogenous endotoxin levels by reducing these factors.
Adult↗
Cerebral metabolism during retrograde cerebral perfusion.
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Animals↗
[Experimental study of optimal perfusion pressure during retrograde cerebral perfusion].
The effects of retrograde perfusion pressure on the brain was experimentally investigated during profound hypothermic circulatory arrest. Fifteen adult mongrel dogs were placed cardiopulmonary bypass and induced profound hypothermia of 20 degrees C at nasopharyngeal temperature. Retrograde cerebral perfusion (RCP) with perfusion pressure of 10 mmHg (RCP10; n = 5), 20 mmHg (RCP20; n = 5), 30 mmHg (RCP30; n = 5) underwent for 60 minutes. The oxygenated blood was infused via the bilateral maxillary veins, and the flow rate was kept to maintain a desired pressure in the external jugular vein for each group. Regional cerebral blood flow (rCBF), excess lactate, cerebrospinal fluid pressure (CSFP), adenosine triphosphate (ATP) concentration of cerebral tissue, and water content of cerebral tissue were measured. In the RCP10 group, cerebral excess lactate was positive and ATP concentration was low. In the RCP30 group, the water content of cerebral tissue was significantly higher than those in the other groups. In the RCP20 group, the excess lactate was maintained in a negative range, and ATP concentration was significantly higher than in the RCP10 group. In conclusion, RCP may provide metabolically adequate support for the brain and a perfusion pressure of 20 mmHg was appropriate for RCP in dogs.
Animals↗
The effect of pulsatile perfusion on cerebral blood flow during profound hypothermia with total circulatory arrest.
In 39 mongrel dogs, regional cerebral blood flow was measured during pulsatile and nonpulsatile deep hypothermic cardiopulmonary bypass with total circulatory arrest. Total circulatory arrest was performed at 20 degrees C cerebral temperature for 40 minutes in 15 dogs, 60 minutes in 12 dogs, and 80 minutes in 12 dogs. Cerebral blood flow in both groups decreased as cerebral temperature fell and there was no significant difference in cerebral blood flow between the two groups during the cooling period. After circulatory arrest for 40 minutes, as cerebral temperature increased to 35 degrees C, cerebral blood flow in both groups recovered to values as high as the respective initial values, which were measured just after the beginning of cardiopulmonary bypass for cooling (102.5% +/- 10.2% in the pulsatile group and 97.2% +/- 12.6% in the nonpulsatile group). After circulatory arrest for 60 minutes, cerebral blood flow in the pulsatile group increased to 141.8% +/- 16.1% of its initial value when the cerebral temperature became 35 degrees C, but it remained significantly lower (64.5% +/- 9.2%) in the nonpulsatile group (p < 0.01). After circulatory arrest for 80 minutes, cerebral blood flow in both groups remained lower than the respective initial values. These results suggest that pulsatile perfusion maintains cerebral blood flow even during profound hypothermia and that it may protect the brain from ischemic and hypoxic damage caused by profound hypothermia and total circulatory arrest in cardiac operations.
Animals↗
[Experimental studies of pulsatile retrograde cerebral perfusion].
This study was investigated for the effects of pulsatile flow on retrograde cerebral perfusion under profound hypothermic circulatory arrest. Fifteen adult mongrel dogs were placed cardiopulmonary bypass and induced profound hypothermia of 20 degrees C at nasopharyngeal temperature. Five dogs were performed non-pulsatile retrograde cerebral perfusion (NP-RCP) and 5 were pulsatile retrograde cerebral perfusion (P-RCP) for 60 minutes each group. The rest of 5 dogs were performed hypothermic circulatory arrest (HCA) without any circulatory assist. Retrograde cerebral perfusion flow rate was regulated to maintain an external jugular vein pressure of 20 mmHg by infusing oxygenated blood by way of bilateral maxillary vein. Regional cerebral blood flow (rCBF), cerebrospinal fluid pressure (CSFP), adenosine triphosphate (ATP) concentration of cerebral tissue, and water content of cerebral tissue were measured. The rCBF were no statistical difference between the two groups. CSFP and ATP concentration in both of NP-RCP and P-RCP were significantly higher than those of HCA. Water content of cerebral tissue in P-RCP were significantly lower than those of NP-RCP. We concluded that retrograde cerebral perfusion for 60 minutes protects the brain as the assistances of circulatory arrest and retrograde cerebral perfusion with pulsatile flow has the possibility to control brain edema as compared with non-pulsatile flow in dogs.
Adenosine Triphosphate↗
Disruption of the expanded polytetrafluoroethylene (EPTFE) graft of axillofemoral by-pass.
The rupture of the artificial vascular graft is a rare complication. The disruption of the expanded polytetrafluoroethylene (EPTFE) graft has never been reported. The present report describes a patient who suffered the disruption of an EPTFE graft five years after a right axillofemoral by-pass.
Aged↗
Hygroscopic stability and dissolution properties of spray-dried solid dispersions of furosemide with Eudragit.
Spray-dried solid dispersions of furosemide-Eudragit RS100 and RL100 (ethyl methacrylate chlorotrimethylammoniumethyl methacrylate copolymer) were studied to determine their stability at 45 degrees C and 0, 44, and 75% relative humidity and their dissolution characteristics. The crystallization rates of the solid dispersions were measured by X-ray powder diffractometry and calculated on the basis of the Jander equation to estimate physicochemical stability in the presence of water vapor. The stability of the solid dispersion depended on the kind of acrylic resins and the drug content. The solid dispersion with a drug: Eudragit RL100 ratio of 1:3 was the most stable at 75% relative humidity. The dissolution profiles of the solid dispersions were measured in a pH 6.8 buffer at 37 degrees C. The equilibrium drug concentration of the solid dispersions were estimated from the dissolution profiles after 24 h. The equilibrium drug concentration decreased with an increasing Eudragit quaternary ammonium group: furosemide molar ratio. The equilibrium drug concentrations of the solid dispersions with > 0.3 mol of the quaternary ammonium group were approximately 0. Thus, the drug was completely adsorbed on Eudragit.
Acrylic Resins↗
Physicochemical stability of phenobarbital polymorphs at various levels of humidity and temperature.
The physicochemical stability of six phenobarbital modifications [forms A, B, C (monohydrate), D (dioxane solvate), E (hemihydrate), and F] at various levels of humidity and temperature were measured using X-ray diffractometry and differential scanning calorimetry. Form D was identified as a new crystalline form (dioxane solvate). Polymorphic transformations of the modifications were investigated by the Kissinger method under nonisothermal conditions. Change of polymorphic content of phenobarbital modifications under various humidity levels at 45 degrees C was evaluated by X-ray powder diffraction. The polymorphic stability under isothermal conditions was estimated kinetically, based upon the Jander equation. Forms A, B, and F were stable at 0 and 75% RH and 45 degrees C for 3 months. On the contrary, forms C, D, and E transformed during storage. The transformation rates of form D were larger than that of forms C and E.
Calorimetry, Differential Scanning↗
Surgical treatment of the Wolff-Parkinson-White syndrome in children.
From 1986 to 1989, seven children ranging in age from 5 months to 16 years underwent surgical treatment for the Wolff-Parkinson-White syndrome at the Shiga University of Medical Science. None of the patients had any other associated congenital heart disease. There was a right free wall accessory pathway in four patients and a left free wall accessory pathway in three. Surgical ablation of these accessory pathways was performed on eight occasions, using the endocardial approach three times and the epicardial approach five. All the children are alive and none has since had episodes of tachycardia. Only one patient had a recurrent delta wave, which was noted 18 months after the operation. Surgical ablation of the accessory pathway for the Wolff-Parkinson-White syndrome can be performed safely, even in infants and children; it is concluded that this useful procedure is capable of improving a patient's quality of life.
Adolescent↗
Acute extensive necrosis of the visceral organs after repair of a ruptured thoracic aortic aneurysm.
A 47-year-old woman was admitted to our hospital for repair of a ruptured thoracic aortic aneurysm. Her post-operative course was uneventful, but she had persistent complaints of anorexia and general fatigue that failed to improve. Thirty-one days after surgery, she complained of severe abdominal pain. Abdominal computed tomography (CT) and X-ray revealed extensive necrosis of the visceral organs. She underwent emergency abdominal exploration and was found to have necrosis of the liver, gallbladder, stomach, entire small bowel and colon. The extensive necrosis made resection of the involved organs unfeasible. The patient died one day after exploratory laparotomy.
Acute Disease↗
Cerebral metabolism and effects of pulsatile flow during retrograde cerebral perfusion.
We evaluated cerebral metabolism during retrograde cerebral perfusion (RCP) and circulatory arrest under profound hypothermia, and also investigated the effect of pulsatile flow on RCP. Eighteen adult mongrel dogs were placed on cardiopulmonary bypass and were cooled to a nasopharyngeal temperature of 20 degrees C. At this temperature, hypothermic circulatory arrest (HCA; n = 6), non-pulsatile RCP (NP-RCP; n = 6), and pulsatile RCP (P-RCP; n = 6) were performed for 60 minutes. Retrograde cerebral perfusion was performed via the bilateral internal maxillary veins, and retrograde flow rate was regulated to maintain a mean perfusion pressure of 20 mmHg in the external jugular vein. During RCP, the temperature was maintained in a narrow range, oxygen consumption and carbon dioxide excretion could be observed, the excess lactate was maintained at a negative value, and cerebral tissue ATP concentration was significantly higher than in the HCA group. The cerebral tissue water content was significantly lower in the P-RCP group than in the NP-RCP group. These findings suggest that hypothermia of the central nervous system, the supply of oxygen, the excretion of metabolites, aerobic metabolism, and the cerebral ATP level were maintained by RCP. In conclusion, RCP may possibly provide adequate metabolic support for the brain during total circulatory arrest, and pulsatile flow appears to reduce cerebral edema when compared with non-pulsatile flow in dogs.
Adenosine Triphosphate↗
[Experimental studies on retrograde cerebral perfusion: efficacy of clamping of the venous blood flow through IVC cannula].
Retrograde cerebral perfusion (RCP) is used to prolong the safe period of circulatory arrest under profound hypothermia. However, this technique now varies in some maneuvers at different institutions. This study investigated the effects on cerebral metabolism of clamping blood flow through the IVC cannula during RCP using fourteen adult mongrel dogs. During circulatory arrest, RCP by way of the bilateral internal maxillary vein was performed. In seven dogs, blood flow was drained through IVC cannula (IVC-drained group) and in the other seven dogs, the blood flow was clamped during RCP (IVC-clamped group). During RCP, the percent of returned blood volume, oxygen consumption, exudation of carbon-dioxide, and oxygen saturation of the returned blood were significantly higher in the IVC-clamped group than in the IVC-drained group, and the concentration of serum CK-BB in the IVC-clamp group was significantly lower than in the IVC-drained group. However, there was no statistical difference between the two groups concerning the regional cerebral blood flow or water content of the cerebral tissue. Concerning about these results, a part of perfused blood passed through not only the extra cranial veno-venous connection but also the intra cranial veno-capillary-venous connection. We concluded that clamping of the venous blood flow through the IVC cannula during RCP is a more protective procedure for cerebral tissue.
Animals↗