Preoperative and postoperative right ventricular function during exercise in patients with mitral stenosis. To elucidate the effects of mitral valve surgery on right ventricular function in 11 patients with mitral stenosis, pre- and postoperative right ventricular function were quantified using gated equilibrium blood pool radionuclide ventriculography at rest and during exercise. The preoperative right ventricular ejection fraction was 39 +/- 4% at rest and 36 +/- 9% during exercise, which during exercise was lower than control values (51 +/- 5%) (p < 0.01). When the preoperative right ventricular ejection fraction was lower during exercise than at rest, postoperative right ventricular ejection fraction during exercise was lower than normal values (42 +/- 3% versus 51 +/- 5%) (p < 0.01). When the preoperative right ventricular ejection fraction did not decrease during exercise, the postoperative right ventricular ejection fraction was within normal limits during exercise (54 +/- 5%). In addition, postoperative right ventricular ejection fraction during exercise increased to normal values in patients whose preoperative right ventricular ejection fraction during exercise had been 40% or higher. Preoperative peak ejection rate was -1.81 +/- 0.19 EDV/sec at rest and -1.72 +/- 0.39 EDV/sec during exercise, which during exercise was lower than control values (-2.44 +/- 0.53 EDV/sec) (p < 0.01). Postoperatively, peak ejection rate during exercise (-2.50 +/- 0.37 EDV/sec) increased (p < 0.05) to normal levels. Preoperative peak filling rate was 1.61 +/- 0.47 EDV/sec at rest and 1.88 +/- 0.54 EDV/sec during exercise, which during exercise was lower than control values (2.58 +/- 0.62 EDV/sec) (p < 0.01). Postoperatively, peak filling rate during exercise (2.82 +/- 0.62 EDV/sec) increased (p < 0.05) to normal values in all patients. Preoperative changes in both right ventricular ejection fraction and peak ejection rate from rest to exercise inversely correlated with the preoperative pulmonary vascular resistance at rest (right ventricular ejection fraction, r = -0.79, p < 0.005; and peak ejection rate, r = -0.67, p < 0.05). In conclusion, right ventricular systolic function improved in about half of the patients with mitral stenosis, and diastolic function improved in all patients during exercise following surgery. When the preoperative pulmonary vascular resistance was elevated, the right ventricular systolic dysfunction persisted.


Surgery for atrioventricular node reentry tachycardia. Results with surgical skeletonization of the atrioventricular node and discrete perinodal cryosurgery. Surgical treatment options for interruption of atrioventricular node reentrant tachycardia include (1) skeletonization of the atrioventricular node by dissecting it from most of its atrial inputs and (2) discrete cryosurgery of the perinodal tissues by applying a series of sequential cryolesions to the atrial tissues immediately adjacent to the atrioventricular node. Both these techniques attempt to interrupt one of the dual atrioventricular node conduction pathways while preserving the other. This report describes 17 consecutive patients who underwent surgical treatment, 10 patients with skeletonization of the atrioventricular node and seven patients with discrete perinodal cryosurgery. There were 10 female and seven male patients and their ages ranged from 28 to 56 years (mean 38). Two of the 17 patients had Wolff-Parkinson-White syndrome and their accessory pathways were interrupted before the atrioventricular nodal reentrant tachycardia was ablated. All the procedures were performed in a normothermic beating heart while atrioventricular conduction was monitored closely. In the skeletonization technique, the right atrial septum was mobilized and the atrioventricular node exposed anterior to the tendon of the Todaro. The perinodal cryosurgical procedure was also performed through a right atriotomy and a series of sequential 3 mm cryolesions were placed around the borders of the triangle of Koch on the inferior right atrial septum. There were no operative deaths. Two patients who underwent the skeletonization operation had heart block necessitating pacemaker therapy. At postoperative electrophysiologic study, no echoes or atrioventricular nodal reentrant tachycardia were inducible in any of the 17 patients. All patients have remained free of arrhythmia recurrence and have required no antiarrhythmic therapy after a follow-up of 5 to 28 months (mean 14). In conclusion, both atrioventricular node skeletonization and perinodal cryosurgery successfully ablate atrioventricular nodal reentrant tachycardia; however, perinodal cryosurgery appears to be safer in avoiding heart block, is more easily performed, and is our procedure of choice for the management of medically refractory atrioventricular nodal reentrant tachycardia.


Quantitation of mapping uncertainty in Wolff-Parkinson-White syndrome. Implications for anatomic characterization and surgical division of accessory atrioventricular connections. The purpose of this study was to quantitate the uncertainty inherent in the electrophysiologic mapping of ventricular preexcitation as seen in Wolff-Parkinson-White syndrome. An ink-coated needle electrode was constructed to serve as a point source of unipolar stimulation along the atrioventricular junction. Activation times for 11 ventricular mapping sites at the atrioventricular junction were measured for each stimulation point. Maps were successfully completed for 18 right free wall and 14 posterior septal stimulation points. The activation time at the mapping site closest to the stimulation point was termed the index activation time. Activation times identical to the index activation time were noted at 1.3 +/- 0.5 mapping sites for each free wall stimulation point and 1.9 +/- 0.9 mapping sites for each septal stimulation point (p < 0.05, septal versus free wall stimulation points). Activation times falling within 5 msec of the index activation time were noted at 2.4 +/- 1.0 mapping sites for each free wall stimulation point and at 3.9 +/- 1.4 mapping sites for each septal stimulation point (p < 0.05, septal versus free wall stimulation points). The uncertainty of electrophysiologic mapping can be quantitated, and this error should be considered when making inferences regarding the anatomy of accessory pathways based on electrophysiologic data. A knowledge of the uncertainty inherent in the localization of accessory atrioventricular connections by electrophysiologic mapping can be used to plan borders of surgical dissection that will account for this uncertainty at a 95% confidence level.


Mid-infrared pulsed laser ablation of the arterial wall. Mechanical origin of "acoustic" wall damage and its effect on wall healing. Pulsed mid-infrared lasers are an alternative to excimer lasers for transluminal angioplasty. The mid-infrared lasers, however, were reported to produce "acoustic" wall damage that might impair the immediate and long-term results. To study the immediate and long-term effects on the arterial wall, 184 craters (1 mm diameter and 1 mm depth) were produced perpendicular to the intimal lining in the thoracic aortas of pigs. Three types of craters were evaluated: Ho-YSGG laser-induced (lambda = 2.09 microns, 2 pulses of 500 microseconds, 0.50 joule/pulse, 50 gm force), mechanically drilled, and "acoustic" craters. "Acoustic" craters were produced by two laser pulses delivered into a saline-filled metal fiber cap, which was placed in a mechanically drilled crater. The metal cap was provided with four outlets for water vapor and isolated "acoustic" from optical and thermal laser effects. The pigs survived 3, 14, and 28 days. Arterial wall damage, medial necrosis, and wall healing were assessed microscopically. At 3 days, laser and "acoustic" craters were accompanied by large tissue ruptures (2.7 +/- 0.9 mm and 2.9 +/- 0.8 mm, respectively, mean +/- standard deviation). These were attributed to large vapor bubbles expanding within the tissue. A zone of medial necrosis was observed adjacent to the laser craters (0.43 +/- 0.15 mm) and to the "acoustic" craters (0.17 +/- 0.14 mm). Neither ruptures nor necrosis was observed with the mechanical craters. At 2 and 4 weeks, the necrotic areas were repopulated with smooth muscle cells and all craters were adequately filled with smooth muscle cells, without any sign of an exaggerated proliferative response. We conclude that within the arterial wall, Ho-YSGG ablation was accompanied by the rapid expansion of a water vapor bubble. The formation of the relatively large vapor bubble is inherent to the use of a mid-infrared laser. The risk of creating dissections clinically, when delivering Ho-YSGG laser pulses, remains to be determined. The present study provided no indication that the arterial wall fissures might affect the restenosis rate unfavorably by promoting myointimal proliferation.


Current trends in lung transplantation. Lobar transplantation and expanded use of single lungs. Heart-lung transplantation remains the only therapeutic option for patients with combined end-stage cardiopulmonary disease. Because of the scarcity of heart-lung donors, we have been investigating other surgical alternatives for patients with end-stage vascular and parenchymal lung disease. From June 1989 through June 1991, 48 patients underwent pulmonary transplantation. Seventeen of the 48 patients underwent single lung transplantation. Of the 17 patients in the single lung group, eight patients had pulmonary hypertension and nine had parenchymal lung disease. Four of the 17 patients underwent repair of a cardiac defect with single lung transplantation. One-year actuarial survival was 68%. Pulmonary function has been excellent. The forced expiratory volume in 1 second was 79.6 +/- 13.6 (percent predicted), forced expiratory flow 25%-75% was 72.6 +/- 14.5 (percent predicted), and arterial oxygen tension was 82.8 +/- 10.06 mm Hg when measured at annual follow-up in a group of eight patients without obliterative bronchiolitis. Pulmonary artery pressures of systemic level or greater in the group with pulmonary vascular disease were normal at annual catheterization. Most patients had at least one episode of allograft rejection. Actuarial freedom from rejection at the end of 3 months was 30%. Three of the 17 single lung patients receiving lung lobes were children. Two children received living-related lobe transplants and one neonate received a lobe from a 2-year-old cadaver donor. Single lung transplantation is an effective therapeutic option for selected patients with vascular or parenchymal lung disease. Expanding indications will permit more individuals to receive transplants from the existing donor pool. Living-related and cadaver lobe transplantation will also increase the options available to children in need of lung transplantation.


An experimental study on direct revascularization of bronchial circulation by microvascular anastomosis. The effects of direct revascularization of the bronchial artery after bronchoplasty were estimated by laser Doppler velocimetry and india ink injection in dogs. Bronchoplastic surgery at the right main bronchus was performed in all dogs, and the bronchial artery was reconstructed using the internal thoracic artery in the reconstruction group. The mucosal blood flow was measured at the distal side of the anastomosis. India ink was injected into the aorta in the nonreconstruction group and into the internal thoracic artery in the reconstruction group. The peripheral blood flow had diminished immediately after surgeries to 59% of the baseline value and took 14 days to recover to the baseline value in the nonreconstruction group. However, in the reconstruction group, the blood flow recovered at once to 78% of the baseline value and had returned to that value in 5 days. Statistically significant differences were noted between the groups from just after operation to day 7. India ink data confirmed these findings. In the nonreconstruction group, no ink was observed in the peripheral bronchial vessels on day 3; it was noted in part of the vessels on day 7 and in most on day 14. On the other hand, a relatively large number of vessels were stained just after operation in the reconstruction group. Thus reconstruction of the bronchial artery by means of the anastomosis with the internal thoracic artery can be said to be a useful and effective method for preventing airway ischemia.


Reliable thirty-hour lung preservation by donor lung hyperinflation. We examined the hypothesis that the degree of inflation of the lungs at the time of harvest may have an important role in postpreservation function. Lungs of donor dogs randomly assigned to groups 1 (n = 5) and 2 (n = 5) were ventilated with large tidal volumes (tidal volume, 25 ml/kg; positive end-expiratory pressure, 5 cm H2O; respiratory rate, 12 breaths/min, inspired oxygen fraction 1.0) and were inflated to 30 cm H2O for 15 seconds before pulmonary artery flush and again immediately before tracheal crossclamping. In group 3 (n = 5) donor lungs were normally ventilated (tidal volume, 12.5 ml/kg, positive end-expiratory pressure 0 cm H2O; respiratory rate 12 breaths/min, inspired oxygen fraction, 1.0) and were not hyperinflated before pulmonary artery flushing; the trachea was crossclamped at end-inspiration. In groups 1 and 3 a large bolus (25 micrograms/kg) of prostaglandin E1 was injected into the pulmonary artery before flushing and was also added to the pulmonary artery flush solution (500 micrograms/L). A rapid (approximately 50 seconds), high-volume mm Hg), hypothermic (4 degrees C) pulmonary artery flush was performed in all hypothermic (4 degrees C) pulmonary artery flush was performed in all groups with modified Euro-Collins solution. Heart-lung blocks were stored at 4 degrees C for approximately 29 hours before left single lung allografting. An inflatable cuff was placed around the recipient right pulmonary artery, allowing independent study of the transplanted lung. Hyperinflated lungs harvested with or without prostaglandin E1 provided equivalently excellent early posttransplant function (arterial oxygen tension [mean +/- standard deviation]: group 1; 503 +/- 45, vs group 2; 529 +/- 150 mm Hg; inspired oxygen fraction 1.0). Mean arterial oxygen tension was significantly lower in group 3 (116 +/- 78 mm Hg) than in either groups 1 or 2 (p < 0.0002 for either comparison). Copious reperfusion pulmonary edema was a constant feature in group 3 but was not seen in groups 1 and 2. All 10 recipients in groups 1 and 2 survived the 3-day assessment period without difficulty; two of the five recipients in group 3 died during initial unilateral perfusion of the transplanted lung. Donor hyperventilation and inflation to 30 cm H2O before hypothermic storage can help provide excellent posttransplantation lung function after 30-hour preservation, with or without prostaglandin E1 pretreatment. We speculate that this improvement may be due to effects of increased lung volume on pulmonary vascular tone and/or surfactant metabolism.


Effects of the pericardium on left ventricular diastolic filling and systolic performance early after cardiac operations. To determine whether closure of the pericardium after cardiac operations affects the filling characteristics and systolic performance of the left ventricle, we measured left ventricular volume, pressure, cardiac index, and stroke work index in 10 patients between 11 and 15 hours after cardiac operations, with the pericardium first closed and then open. At the time of operation, radiopaque tantalum markers were inserted in the left ventricular myocardium to outline the chamber in the 30-degree right anterior oblique projection, and the pericardium was closed by a continuous polypropylene suture exteriorized at both ends of the sternotomy. The patient was then transferred to the surgical intensive care unit, where left atrial pressure was measured via a fluid-filled catheter, left ventricular pressure with a micromanometer-tipped catheter, and myocardial oxygen consumption via a coronary sinus catheter. Left ventricular volume was measured by computer-aided analysis of fluoroscopic images (recorded at 30 frames per second) of the implanted myocardial markers. Left atrial pressure was maintained at target values of 10, 15, and 20 mm Hg by intravenous augmentation of blood volume. Left ventricular and left atrial pressures and volumes were measured with the pericardium closed; the pericardium was then opened by withdrawal of the pericardial suture. Radiopaque clips on the pericardial edges confirmed opening of the pericardium seconds after withdrawal of the suture. Repeated measurements of left ventricular pressures and volumes were then made at the target left atrial pressures with the pericardium open. End-diastolic volume index, peak positive time derivative of pressure, stroke work index, and cardiac index all increased significantly when the pericardium was opened (p < 0.001). Thus we found the following: (1) At physiologic pressures, the pericardium had a significant constraining effect on diastolic filling of the left ventricle, and (2) opening of the pericardium resulted in increased cardiac index and stroke work index. These increases may be attributed to the Frank-Starling response to increased left ventricular preload. The demonstrated improvement in left ventricular systolic performance should be considered when contemplating closure of the pericardium after cardiac operations, especially in patients with preoperative left ventricular dysfunction.


Homologous blood transfusion as a risk factor for postoperative infection after coronary artery bypass graft operations. Homologous transfusions are immunosuppressive and associated with a higher risk of postoperative infection. In this retrospective analysis, we studied 238 consecutive patients who underwent first-time coronary operations by a single surgeon in 1988 to 1989 and collected clinical and laboratory data relevant to postoperative infections including pulmonary, urinary, and wound sites. Culture-proved postoperative infections occurred in 16 of the 238 patients (6.7%), with only 3 (1.3%) being deep sternal wound infections. Seven of 16 (44%) of the infections were away from the wound sites, suggesting that nonsurgical variables contributed to at least some infections. Factors significantly associated with an increased risk of postoperative infection by univariate analysis included female sex, diabetes mellitus, and transfusion dose. Infections occurred in 3.9% of patients receiving up to 2 units of red cells and whole blood, 6.9% receiving 3 to 5 units, and 22% of those receiving 6 units or more. Multiple linear and logistic regression analysis showed that transfusion dose was the most significant predictor of infection, days of fever, days of antibiotic therapy, and length of hospital stay. Homologous transfusion is associated (in a dose-dependent fashion) with a threefold to eightfold increased risk of postoperative infection in patients undergoing coronary artery operations. This increased risk of infection may be due to transfusion-induced immunosuppression of the patient.


Spinal cord protection with intravenous nimodipine. A functional and morphologic evaluation. The purpose of this study is to determine the effects of ischemia in the spinal cord when a calcium channel blocker, nimodipine, is administered intravenously before, during, and after crossclamping of the thoracic aorta. In this series of experiments, 18 pigs underwent thoracotomies and had 17.5 to 18.0 cm of the thoracic aorta clamped for 30 minutes. By random selection, nine animals received intravenous nimodipine (2 micrograms/kg per minute) and nine control animals received only a carrier solution. Of the nine animals that received nimodipine, eight walked after the operation. In contrast, in the control group only two of nine animals walked. The ninth nimodipine-treated animals walked but had a severe delayed deterioration response. All animals, except one control animal, had a negative central spinal perfusion pressure. Morphologic examination of serial sections of spinal cords from control animals showed diffuse neuronal necrosis. In comparison, cords from the nimodipine group had swollen neurons accompanied by an inflammatory infiltrate and only occasional necrotic neurons. With this data, we conclude that certain calcium channel blockers, when administered in sufficient doses, can lend a protective effect to the spinal cord during ischemic events even when cord perfusion pressure has dropped to dangerously low levels.


Simple hypothermic retrograde cerebral perfusion during aortic arch replacement. A preliminary report on two successful cases. We recently found that hypothermic retrograde cerebral perfusion can be performed by simply elevating the central venous pressure in Trendelenburg's position while the aortic arch is open. In this technique, with an occlusion balloon in the descending aorta, deep hypothermic perfusion of the lower half of the body is performed as oxygen-rich venous blood supplies the brain. Two successful cases are reported: one of dissecting aortic aneurysm, DeBakey type II, with a true aortic arch aneurysm, in a 53-year-old woman, and one of acute aortic dissection, DeBakey type I, in a 53-year-old man. With the brain under retrograde perfusion at a rectal temperature of 15 degrees C and a central venous pressure of 15 mm Hg, replacement of the ascending to the descending aorta in the former case and to the proximal aortic arch in the latter case was successful. Cerebral circulatory arrest times were 81 and 65 minutes, respectively. No neurologic deficit was found postoperatively. It is suggested that this simple technique protected the brain for a long period of cerebral circulatory arrest during the aortic arch operation by supplying it with oxygen and simplifying the operative procedure.


Cardiopulmonary bypass and the blood-brain barrier. An experimental study. The diffuse inflammation produced by cardiopulmonary bypass might disrupt the blood-brain barrier and lead to the transient neurologic dysfunction occasionally seen after cardiac operations. To evaluate this possibility, blood-brain barrier integrity was measured by carbon 14-aminoisobutyric acid tracer technique after 2 hours of cardiopulmonary bypass in piglets. Six animals were cooled to 28 degrees C on cardiopulmonary bypass and then rewarmed to 38 degrees C before carbon 14-aminosisobutyric acid was injected intraarterially. A control group of six animals underwent median sternotomy and heparinization but were not placed on cardiopulmonary bypass. Blood-to-brain transfer coefficients for carbon 14-aminosisobutyric acid were calculated for multiple brain regions; higher coefficients reflect greater flux of carbon 14-aminosisobutyric acid and suggest loss of blood-brain barrier integrity. The brain regions examined and their transfer coefficients (cardiopulmonary bypass versus control mean +/- standard error of the mean ml/gm/min) were middle cerebral artery territory cortex (0.0032 +/- 0.0002 versus 0.0030 +/- 0.0002; p = 0.42), diencephalon (0.0031 +/- 0.0003 versus 0.0029 +/- 0.0002; p = 0.50), midbrain (0.0028 +/- 0.0002 versus 0.0027 +/- 0.0002; p = 0.86), cerebellum (0.0036 +/- 0.0003 versus 0.0029 +/- 0.0002; p = 0.22), and spinal cord (0.0035 +/- 0.0003 versus 0.0041 +/- 0.0008; p = 0.48). There were no significant differences in transfer coefficients between animals placed on cardiopulmonary bypass and control animals in any brain region examined. The pituitary gland lacks a blood-brain barrier and had a correspondingly high coefficient in control animals and those undergoing cardiopulmonary bypass (0.077 +/- 0.012 versus 0.048 +/- 0.008; p = 0.07). Two hours of moderately hypothermic cardiopulmonary bypass does not disrupt the blood-brain barrier.


Patient memory before and after cardiac operations. The memories of 20 patients undergoing elective operations on the heart were assessed by a comprehensive battery of standardized psychometric tests. Testing was conducted 1 to 2 days before, 7 to 10 days after, and 1 month after each operation. Twenty age-matched, healthy control subjects were given the same battery of tests at comparable times. Compared with healthy subjects, the patient group had significantly lower scores on 3 of 19 tests before, 10 of 19 tests 1 week after, and 5 of 19 tests 1 month after surgical intervention. The patient group had similar test performances before and 1 week after the operations and improved on 3 of 19 measures 1 month after the operations. Degrees of illness and cardiopulmonary bypass variables were significantly related to only a small subset of memory measures. Results of this study are consistent with previous reports that underscore the contribution of nonspecific aspects of surgical intervention to neuropsychologic dysfunction in the immediate postoperative period. We conclude that neither the illness nor the surgical variables are directly related to substantial variance in cognitive function after operations on the heart.


Full-thickness dynamic cardiomyoplasty of the left ventricle with free revascularized latissimus dorsi myografts. An experimental feasibility study. Dynamic cardiomyoplasty, with use of a free latissimus dorsi myograft revascularized by the internal thoracic artery and vein, was performed in eight dogs subjected to electrical preconditioning for 8 to 12 weeks (group I) and in six unconditioned dogs (group II). The procedure was performed after the resection of the anterior wall of the left ventricle. Cardiac output and left ventricular stroke work were augmented by 23.7% +/- 9.4% and 44.1% +/- 15.9% after graft pacing with 50 Hz burst stimulation at a 1:1 synchronization ratio, while left atrial pressure ranged from 8 to 12 mm Hg. Analysis of the left ventricular function curve showed that graft pacing at rates of 1:1, 2:1, and 3:1 augmented global left ventricular function. Hemodynamic benefit by continuous pacing at a 3:1 ratio was seen for 1.97 +/- 1.90 hours (0.5 to 6.1 hours) in group I until complications unrelated to the graft terminated the study, while it lasted for only 0.19 +/- 0.09 hour in group II. During the stimulation, the ratio of the lactate output to the oxygen consumption of the graft in group I, a possible indicator of metabolic shift, was significantly less than in group II, (0.46 +/- 0.58 and 6.34 +/- 1.73; p < 0.01). We conclude that free grafts of transformed latissimus dorsi muscle can augment global left ventricular performance, with a physiologic preload by oxidative metabolism, and provide a viable option in full-thickness dynamic cardiomyoplasty.


Warm glutamate/aspartate-enriched blood cardioplegic solution for perioperative sudden death. This report describes an initial experience applying warm glutamate/aspartate substrate-enriched blood cardioplegic solution to resuscitate hearts in 14 patients with witnessed perioperative arrest. Ten patients were in stable hemodynamic condition in the catheterization laboratory (n = 3) or intensive care unit when sudden irreversible fibrillation developed. It progressed to electromechanical arrest in six patients. In patients with preoperative or postoperative arrest, conventional cardiopulmonary resuscitation and defibrillation were unsuccessful and extracorporeal circulation was started 22 to 150 minutes after arrest. The left ventricle was vented, the aorta clamped, and warm (37 degrees C) aspartate/glutamate blood cardioplegic solution was given at a rate of 150 ml/min for 20 minutes. All bypass grafts were open with good flows in patients who had had coronary bypass, and coronary bypass was done in the three patients who had preoperative arrest. Eleven of 14 hearts resumed normal sinus rhythm after aortic unclamping, only two electrocardiographically proved infarctions occurred, and 13 patients had complete hemodynamic recovery with improved ejection fraction. Three patients died: one of progressive cardiogenic shock, another of mediastinitis, and the third of irreversible neurologic damage. Eleven patients were discharged from the hospital and are well after a follow-up period between 3 and 9 months. We conclude that witnessed perioperative arrest with intractable ventricular fibrillation should be treated aggressively by administering cardiopulmonary resuscitation during prompt transfer to the operating room for total vented bypass and delivery of warm substrate-enriched blood cardioplegic solution. This treatment may salvage hearts thought to be damaged irreversibly and may be a feasible approach to intractable witnessed cardiac arrest, provided cardiopulmonary resuscitation maintains satisfactory cerebral perfusion pressure.


Effect of an oxygen-enriched solution and multiple dosing of antegrade crystalloid cardioplegic solution on myocardial metabolism during coronary artery bypass graft operations. The metabolic effect of excessive oxygenation and frequency of administration of antegrade crystalloid cardioplegic solution was assessed in 33 patients undergoing routine coronary artery bypass graft operations. Four patient groups were designed in which the initial aortic root injection was 1000 ml and then 100 ml administered through the vein grafts after completion of each distal anastomosis. The groups were divided as follows: group 1, single dose, normally oxygenated cardioplegic solution infused via the aortic root; group 2, single dose, high oxygen content cardioplegic solution infused via the aortic root; group 3, normally oxygenated cardioplegic solution with additional 250 ml doses via the aortic root every 20 minutes; group 4, high oxygen content cardioplegic solution with additional 250 ml doses via the aortic root every 20 minutes. In all groups myocardial mean septal temperature showed an immediate fall to approximately 11 degrees C with the initial aortic root doses and then a gradual rewarming to approximately 20 degrees C during the crossclamp period (mean 58.6 minutes). Metabolic parameters measured or calculated from the coronary sinus effluent were myocardial oxygen extraction, lactate production, base deficit, inorganic phosphate, glucose, potassium, creatine kinase (total and myocardial band fraction), and catecholamine production. There was no statistically significant difference in any of these determinations between each patient group. Furthermore, myocardial recovery, myocardial performance, and postoperative recovery characteristics were not different. We conclude that single or multidose aortic root crystalloid cardioplegic solution (either oxygen enriched or normally oxygenated) is equally effective in routine coronary artery bypass graft operations when septal temperatures are maintained between 15 degrees and 21 degrees C for a total arrest time of 60 minutes or less. In this study, increasing the volume cardioplegic solution given in multiple doses appeared to offer no significant metabolic or functional advantage in patients without complications who had satisfactory left ventricular function.


Assessment of regional and transmural myocardial perfusion by means of intraoperative myocardial contrast echocardiography during coronary artery bypass grafting. By using intraoperative myocardial contrast echocardiography, we assessed regional myocardial perfusion and transmural blood flow distribution immediately after myocardial revascularization. A total of 62 revascularized myocardial areas were studied in 31 patients undergoing coronary artery bypass grafting. The revascularized areas were divided into three different areas: S area, supplied by significantly stenosed coronary arteries (43 areas); C area, supplied by coronary collateral situation associated with totally occluded coronary arteries (12 areas); MI area, preexisting transmural myocardial infarction (7 areas). Myocardial contrast echocardiography was obtained by direct injection of 2 ml of sonicated 5% human albumin into the saphenous vein grafts at rest and during atrial pacing. Each area was divided into two layers of endocardial and epicardial halves, and myocardial enhancement of peak intensity was measured for each half and endocardial/epicardial gray level ratio was calculated: (1) The peak intensity of myocardial enhancement in S area and C area was significantly higher than that in MI area at rest as well as during pacing after myocardial revascularization. There was no significant difference in the peak intensity between S area and C area both at rest and during pacing. In S area the peak intensity significantly increased during pacing (p < 0.01), whereas it did not change in C area and MI area. (2) S area demonstrated no significant change in endocardial/epicardial intensity ratio during pacing. In contrast, the ratio in C area significantly decreased during pacing. (3) In S area with preoperative percent increase of segmental wall thickening lower than 25%, there was a significant correlation (r = 0.84, p < 0.001) between the peak intensity of myocardial enhancement and the postoperative changes of percent increase of segmental wall thickening in the revascularized areas. Thus, immediately after myocardial revascularization, intraoperative myocardial contrast echocardiography could provide a quantitative assessment of regional myocardial perfusion as well as blood flow distribution in the areas with myocardial infarction and with coronary collateral situation and in the areas supplied by stenosed coronary arteries.


Physiologic assessment and surgical management of diffuse esophageal spasm. The physiologic abnormalities and management of patients with diffuse esophageal spasm are controversial. We evaluated the symptomatic and functional results of surgical therapy in 19 patients with diffuse esophageal spasm who were incapacitated with dysphagia and chest pain and unresponsive to conservative management. A long esophageal myotomy with an antireflux procedure was performed in 15 patients, and four patients with multiple previous esophageal procedures had an esophagectomy. Eleven patients had increased esophageal exposure to gastric juice on preoperative 24-hour esophageal pH monitoring. The severity of dysphagia, chest pain, regurgitation, and heartburn was scored on a scale of 0 to 3 before and a mean of 24 months (range 8 months to 13 years) after the operation. After myotomy, each of these symptoms and the overall symptom score improved significantly (p < 0.01). The improvement in the symptom scores in the patients who had esophagectomy were comparable with the improvement after myotomy. On self-assessment, 90% of the patients would have the operation again if again faced with the decision. Standard and ambulatory 24-hour manometry showed a significant reduction in the amplitude of the esophageal body contractions, a decrease in the frequency of simultaneous contractions, and the elimination of multi-peaked waves after the myotomy. Despite the addition of an antireflux procedure, lower esophageal sphincter pressure, overall length, and abdominal length were reduced markedly after the myotomy. This was associated with persistent or emerging heartburn or regurgitation in four patients. These data indicate that a long esophageal myotomy is a valid treatment alternative in appropriately selected patients with diffuse esophageal spasm. Esophagectomy and colon interposition is the procedure of choice in patients with multiple previously failed myotomies.


Plasma cell granuloma of the lung.

Plasma cell granuloma of the lung. Plasma cell granuloma is an uncommon, nonneoplastic pulmonary lesion. An 11-year retrospective review of resected pulmonary tumors yielded six patients with plasma cell granulomas. Fine needle aspiration biopsy results were falsely positive for carcinoma in one patient. Adherence or invasion of the mediastinum was present in three patients. Granuloma in one patient, who underwent two operative procedures, was deemed unresectable at the initial thoracotomy. For both diagnostic and therapeutic reasons, early surgical excision is recommended for plasma cell granulomas of the lung.


Surgical treatment of pulmonary metastases from uterine cervical cancer. Operation method by lung tumor size. Between 1959 and 1986, 32 patients with pulmonary metastatic tumors from squamous cell carcinoma of the uterine cervix underwent pulmonary resection. The method of pulmonary resection was correlated with the pathology of the metastases. In 20 patients with pulmonary metastatic lesions 3 cm in diameter or larger, secondary lymph node involvement was observed in 65% and microscopic satellite lesions around the main metastatic lesion were seen in 50%. On the other hand, in none of 12 patients having metastatic lesions smaller than 3 cm was there accompanying lymph node involvement, and microscopic satellite lesions were observed in only one patient among them. Consequently, we concluded that wedge resection with a disease-free margin of 2 cm or a little more from the tumor edge was appropriate for lesions smaller than 3 cm in diameter, and lobectomy with lymph node dissection was necessary for lesions 3 cm in diameter or more.


Tracheal sleeve resection for iatrogenic stenoses (subglottic laryngeal and tracheal). Since 1975 200 tracheal sleeve resections for iatrogenic tracheal and subglottic laryngeal stenoses have been performed in our institution. Preoperative Nd:YAG laser is of paramount help in opening the stenoses. Tracheography is usually performed to specify the length of the stenosis and the distance from the vocal cords. Operative procedures are described. One hundred seventy five (87.5%) patients are definitely cured, but in this group 16 patients required a Montgomery tube for 6 months to 1 year to recover a normal tracheal diameter. Two patients needed a second tracheal sleeve resection. Nine (4.5%) patients died, and 16 (8%) had recurrent stenoses. Stenoses in these patients were treated with use of a tracheostomy tube, a permanent Montgomery tube, or an endotracheal stent. Partial anterior cricoid resections performed in 21 patients have had the same results as those of the whole series. Twenty one laryngeal releases were performed and proved to be efficient and safe. In our experience complications can be avoided by good selection and preparation of the patients, accurate identification of the level and length of the stenosis, and meticulous technique.


Effects of low-dose steroids on bronchial healing after sleeve resection. A clinical study. We prospectively evaluated the effect of low-dose steroids after bronchial sleeve resection in 20 consecutive patients. Ten patients (group I) did not receive steroids. Ten patients (group II) received 10 mg of methylprednisolone intravenously intraoperatively and 10 mg intramuscularly every day for 10 days. In addition, group II patients received 250 mg of hydrocortisone succinate endobronchially before extubation and 5 mg of methylprednisolone daily in an aerosol solution. Bronchoscopy was performed in all patients before extubation, every day for 10 days, and 1 and 3 months after the operation. Bronchial healing was graded endoscopically from grade I (no edema, excellent healing) to grade V (dehiscence). In group I, three patients showed grade I, four had grade II, one indicated grade III, one revealed grade IV (granuloma), and one showed grade V (dehiscence) healing. Mean postoperative hospital stay was 9.7 days. In group II all 10 patients showed grade I healing. Mean postoperative hospital stay was 7.3 days. We conclude that low-dose steroids improve the postoperative course in patients undergoing bronchial sleeve resection.


Desmoid tumors of the chest wall. A locally recurrent problem. Desmoid tumors, in general, are known for their propensity to recur. To evaluate treatment and results, we reviewed the records of 32 patients admitted to our institution with a chest wall desmoid tumor from 1948 to 1988. There were 13 men and 19 women whose ages ranged from 12 to 67 years (median 36 years). Four patients had Gardner's syndrome. Treatment was wide resection. Median follow-up was 110 months. The overall 5-year survival was 93%; 5-year disease-free survival was 71%. The 5-year local recurrence rate was 29%. Since death from disease is uncommon after resection, but local recurrence is common, we recommend aggressive wide resection in patients who have desmoid tumors of the chest wall when seen initially.


Bidirectional cavopulmonary anastomosis in patients under two years of age. Between December 1986 and December 1990, a bidirectional cavopulmonary anastomosis was performed in 27 patients younger than 2 years of age, including 12 with heterotaxia syndrome. Age and weight of patients averaged 14.2 +/- 6.6 months and 8.1 +/- 2.2 kg, respectively. Eleven had pulmonary atresia and 16 had pulmonary stenosis. The main pulmonary artery was ligated in seven patients in the latter group (subsequently reopened in one) and left open in nine (subsequently ligated in two). There were four hospital deaths (15%). All patients were discharged with anticoagulant/antithrombotic therapy to be continued for 6 months. There were two late deaths before further operations (8.7%). Two patients, one with acquired massive pulmonary arteriovenous fistulas and one with progressive common atrioventricular valve regurgitation, subsequently underwent definitive repair (biventricular in one), and both died. Heterotaxia syndrome (p = 0.087) and preoperative mean pulmonary artery pressure higher than 15 mm Hg (p = 0.09) were the only risk factors for overall mortality.


Midterm results with cryopreserved allograft valved conduits from the right ventricle to the pulmonary arteries. From 1985 to 1990, 89 patients underwent placement of 41 aortic and 54 pulmonic cryopreserved allograft valved conduits between the right ventricle and the pulmonary arteries. Six patients underwent replacement with a second allograft conduit. Median age at operation was 4.3 years, and 20 patients were infants less than 1 year of age. Conduit sizes averaged 11 mm in the conduits placed in 20 infants and 20 mm in the 75 placed in patients more than 1 year of age. There were 7 early deaths in 89 patients (7.8%, 70% confidence levels 5.4% to 11.3%) and 9 late deaths in 82 hospital survivors (11%, 70% confidence levels 8% to 15%). Actuarial survival was 81% (70% confidence levels 75% to 86%) at 33 months, and no deaths were due to conduit problems. Late reoperation was required in 13 patients (7 for conduit obstruction, 1 for conduit valve insufficiency, and 5 for nonconduit-related problems). Six of the eight reoperations were done in patients who had small (< or = 13 mm) conduits placed during infancy. Conduit failure was similar between pulmonic and aortic allografts. There were no deaths in the eight patients who required conduit reoperation. Actuarial freedom from reoperation for conduit dysfunction was 80.5% (70% confidence levels 72% to 86%) at 53 months for the entire group and 94% (confidence levels 88% to 97%) at 44 months for patients more than 1 year of age. Cryopreserved allograft conduits have good early and midterm results and are comparable to porcine xenograft conduits. Despite a likely need for replacement within 3 years, we continue to favor the use in infants of an allograft valved conduit over a xenograft Dacron conduit. The need to replace a cryopreserved allograft conduit appears similar for conduits of aortic or pulmonic origin.


Evaluation of right ventricular function by regional wall motion analysis in patients after correction of tetralogy of Fallot. Comparison of transventricular and nontransventricular repairs. Right ventricular function was assessed by regional wall motion analysis and by global function in 62 patients after repair for tetralogy of Fallot. Its relation to surgical procedures, with special attention to right ventriculotomy, was investigated. Patients were classified as follows: group Ia (n = 17), transpulmonary-transatrial repair without right ventriculotomy; group Ib (n = 22), transpulmonary-transatrial repair with minimal right ventriculotomy and small transannular patch; and group II (n = 23), transventricular repair with or without transannular patch. For regional wall motion analysis, fractional area change was used for three anterior parts obtained from hemiaxis area analysis of the lateral right ventriculogram. Ejection fractions were used for global right ventricular function. Functional assessment was done both at rest and during isoproterenol infusion, which is a stress test to evaluate cardiac functional reserve. At rest, group Ia showed better right ventricular anterior wall motion as well as global ejection fraction than did group II. Group Ib showed a global ejection fraction comparable to group Ia, with better regional wall motion in the middle anterior part of the right ventricle despite the depressed upper and lower anterior parts of the right ventricle. Group II showed depressed wall motion of the middle anterior part and the resultant impaired global ejection fraction. During isoproterenol infusion, group Ia showed significant increase in fractional area change of all anterior parts and in global ejection fraction. Group Ib showed significant increases in fractional area change at the middle and lower parts and in global ejection fraction comparable with group Ia. Otherwise, group II showed no significant change in fractional area change, or in global ejection fraction, at the upper and middle parts. These results indicated that transpulmonary-transatrial repair for tetralogy of Fallot provided better postoperative global right ventricular function and its reserve, with less impaired regional wall motion, than did the transventricular repair.


Aortic wall stress profile after repair of coarctation of the aorta. It is related to subsequent true aneurysm formation? True aneurysm formation at the site of coarctation repair has been increasingly recognized after synthetic patch aortoplasty. A mathematical model was developed to determine the aortic wall stress profile after coarctation repair with this technique. A two-dimensional nonlinear mathematical model and a three-dimensional finite element model were developed for different physiologic, geometric, and materials properties variables, which were incorporated into an idealized coarctation repair. The models demonstrated that the major variable affecting stress levels in the aortic wall after coarctation repair was the patch geometry. If the patch was allowed to balloon out, the aortic wall stress increased out of proportion to the increase in aortic diameter because of nonlinear effects. The maximal aortic wall stress concentration occurred opposite the patch. Patch stiffness was also an important variable, with a lower stiffness (subclavian flap repair) leading to a higher aortic wall stress for the same patch geometry as a synthetic patch repair. Inferences: Development of true aneurysms after coarctation repair by synthetic patch aortoplasty is likely to result from excessive aortic wall stress due to patch geometry.


Can we predict the long-term function of the subclavian flap angioplasty? Neonatal operations have improved the prognosis for newborn children with aortic coarctation. The 30-day mortality of 123 neonates with isolated coarctation of the aorta collected from nine series was found to be 0.8%. The subclavian flap angioplasty was the most frequently used surgical procedure in this collected series. This technique is relatively new, however, and many questions have yet to be answered. In this study we have done subclavian flap repair in newborn pigs and followed them up to adult ages. The pigs were killed 28 or 44 weeks postoperatively, and the aortas were reexamined. All flaps had grown symmetrically in width and length and parallel to the growth of the descending thoracic aorta. The flaps were macroscopically intact. Signs of degenerative processes were not found. The wall thickness of the subclavian flap increased by growth of the individual fibroelastic lamellar units in the tunica media. This adaptation to the increased wall stress occurred early in life. The wall strength of the flap also increased by thickening of the intimal layer. We conclude that the subclavian flap is well suited to function as a part of the aorta in adult life.


The recognition, identification of morphologic substrate, and treatment of subaortic stenosis after a Fontan operation. An analysis of twelve patients. Twelve children were identified with subaortic stenosis after Fontan's operation. All had absent resting and isoproterenol-provoked pressure gradient before the Fontan procedure. Six had a univentricular heart of left ventricular morphology, three had a single ventricle of right ventricular morphology, one had tricuspid atresia with transposition of the great arteries, one had pulmonary atresia, intact ventricular septum, and hypoplastic right ventricle, and one had corrected transposition with hypoplastic systemic ventricle. The median interval between the Fontan operation and the recognition of subaortic stenosis was 2.5 years. Ten patients underwent surgical treatment after a prior Fontan operation: Five had myectomy and enlargement of ventricular septal defect with two operative deaths; two had placement of a valved conduit from the ventricular apex to the descending aorta, and both died postoperatively; two with single ventricle had subaortic myectomy, and one had enlargement of ventricular septal defect and pulmonary aortic connection. Complete heart block developed in only one patient. Postoperative testing with Doppler echocardiography with color flow imaging demonstrated good relief of subaortic stenosis. All six children who survived the operation are well 4 months to 4 years later. Subaortic stenosis is a progressive lesion that may develop after a Fontan operation. Its surgical treatment continues to carry a significant mortality. Myectomy and enlargement of ventricular septal defect achieve direct relief of the obstruction with minimal risk of heart block.


Does Down syndrome affect prognosis of surgically managed atrioventricular canal defects? The appropriateness of surgical correction of complete atrioventricular canal defect in patients with Down syndrome has been questioned on a cost-benefit basis. Our experience with nonselective correction of all patients with atrioventricular canal defects gave us the opportunity to evaluate the impact of Down syndrome on postoperative survival. Between January 1, 1975, and December 31, 1989, we operated on 94 patients with Down syndrome and on 127 genetically normal patients. One hundred thirty-four patients had partial or intermediate atrioventricular canal defect (28% Down patients) and 87 had complete atrioventricular canal defect (74% Down patients). Thirty-two patients died perioperatively and 10 patients died during the 15-year follow-up. The actuarial survival was 90% in the genetically normal patients and 57% in patients with Down syndrome (p < 0.0001). Nonetheless, when the confounding effects of pulmonary vascular resistance and the prevalence of more severe anatomic forms in patients with Down syndrome were eliminated with a multivariable analysis in the hazard domain, Down syndrome was not a significant independent incremental risk factor. This was verified by fitting parametric survival to actuarial survival graphically and by a testing of fit. Patients with Down syndrome underwent fewer reoperations and fared as well as or even better, on clinical and echocardiographic investigation, than their genetically normal counterparts.


The conduction system in truncus arteriosus and its surgical significance. A study of five cases. Atrioventricular block may occasionally occur after surgical correction of truncus arteriosus. We therefore studied the conduction system by means of serial sections in five cases of truncus (one after surgical intervention) to delineate the course of the conduction system and its relationship to the ventricular septal defect and the membranous septum. In general, the ventricular septal defect is in the anterior septum, confluent with the truncus, and the atrioventricular bundle is posterior and unrelated to the rim of the ventricular septal defect. In cases in which the ventricular septal defect is anterior and separated from the membranous septum by distinct muscle, the ventricular septal defect can be surgically closed without injury to the atrioventricular bundle. If the ventricular septal defect is related to the membranous septum, the atrioventricular bundle may be close to the ventricular septal defect and susceptible to surgical injury. If muscle separates the ventricular septal defect from the membranous septum, the branching bundle is close to the ventricular septal defect and also is susceptible to surgical injury. In one operated case there was partial dissolution of the left bundle branch, and the right bundle branch was involved in surgical closure of the defect. In summary, in truncus the conduction system varies in its course and is related to the location of the ventricular septal defect and its relationship to the membranous septum. The ventricular septal defect may be close to or related to the membranous septum, and the atrioventricular bundle and the beginning of the bundle branches may be vulnerable to surgical injury.


Results of early repair of ventricular septal defect after an acute myocardial infarction. A 10-year experience with early operation for postinfarction ventricular septal defect is reviewed. Twenty-two patients underwent surgical repair; operative mortality was 36% (< 30 days). The actuarial survival was 64% at 1 month, 59% at 1 year, and 47% at 5 years. Risk factors predictive of operative mortality were diabetes (p = 0.001), elevated preoperative right atrial pressure (p = 0.02), the absence of a preoperative intraaortic balloon pump (p = 0.006), and a short time interval between infarct and operation (p = 0.018). Long-term survival was adversely related to diabetes (p = 0.030), elevated preoperative right atrial pressure (p = 0.005), and, surprisingly, survival was better in patients with a greater extent of coronary artery disease (p = 0.023). There were 14 operative survivors (64%) and 11 long-term survivors (3 months to 10 years, mean 6.0 +/- 3.5 years). Six of eleven survivors were in functional New York Heart Association class I, one was in class II, and four were in class III.


Impaired relaxation of the human mammary artery after temporary clamping. Internal mammary artery specimens from 17 patients were each divided into three separate rings. One ring (control) remained in Krebs solution and the other two were clamped for 30 minutes with either a soft or hard jaw clamp. Isometric tensions were measured in an organ chamber by contracting the rings twice with a thromboxane A2 mimetic, U46619, and relaxing the rings first with the endothelium-dependent agent acetylcholine followed by the endothelium-independent agent sodium nitroprusside. Endothelium-dependent maximal relaxation of the rings was impaired from control after both soft (20% versus 91%; p < 0.01) and hard (1% versus 91%; p < 0.01) jaw clamps were used. However, relaxation after use of hard jaw clamps was significantly less than after use of soft jaw clamps (1% versus 20%; p < 0.05). Endothelium-independent maximal relaxation was not impaired from control after soft jaw clamps (89% versus 97%) were applied but was significantly impaired after use of the hard jaw clamps compared with control (73% versus 97%; p < 0.01) and compared with soft jaw clamps (73% versus 89%; p < 0.05). Rings of internal mammary artery specimens from 10 patients from each experimental group were silver stained. The percentage of intact endothelial cells was significantly greater after soft jaw clamping than after hard jaw clamping (39% versus 15%; p < 0.02). These data suggest that soft jaw clamps significantly reduce the degree of vasoactive dysfunction compared with hard jaw clamps. In addition, soft jaw clamps produce fewer morphologic changes in the human mammary artery after temporary occlusion.


Detrimental sequelae on the wall of the internal mammary artery caused by hydrostatic dilation with diluted papaverine solution. We studied the effect of hydrostatic dilation of the internal mammary artery used for coronary revascularization in 10 patients (aged 45 to 79 years, median 63 years). Diluted papaverine solution was injected in the lumen of distal segments of the internal mammary artery, the musculophrenic artery, or the superior epigastric artery that had been obtained at operation; injection was followed by hydrostatic dilation not exceeding a sheer force of 50 gm. In 12 control patients (aged 42 to 76 years, median 64 years) in whom the internal mammary artery had also been harvested for elective myocardial revascularization, similar arterial segments were wrapped in sponges soaked in papaverine solution of the same dilution. In the nondilated group the median (with interquartile range) number of fenestrations in the internal elastic lamina increased from the elastic (21, 7) to the elastomuscular (41, 11) and muscular segments (89, 12) (elastic-elastomuscular: p = 0.006; elastic-muscular: p = 0.006; elastomuscular-muscular: p = 0.003) (Wilcoxon signed-rank test). In none of the three histologic segments were full-thickness disruptions of the intima and disruptions of the internal elastic lamina seen. Similarly, in the dilated group the number of fenestrations in the internal elastic lamina increased from the elastic (25, 18) to the elastomuscular (43, 9) and muscular (100, 13) segments (p values 0.01, 0.01, and 0.006, respectively). In addition, in 20% of the elastic sections, in 17% of the elastomuscular sections, and in 35% of the muscular sections of the dilated group, disruptions of the intima and internal elastic lamina were seen. Comparison of the number of fenestrations in internal elastic lamina in the three histologic segments between the nondilated and dilated groups revealed a significantly greater value in the muscular segments of the latter group (p = 0.01) (Mann-Whitney U test). We concluded that (1) hydrostatic dilation of the internal mammary, musculophrenic, and superior epigastric arteries may have detrimental effects on the histologic characteristics of the intima and the internal elastic lamina and (2) the number of fenestrations in the internal elastic lamina of these arteries is related to the presence or absence of elastic lamellae in the media.


Inhibition of human internal mammary artery contractions. An in vitro study of vasodilators. The internal mammary artery is currently the preferred conduit for myocardial revascularization; however, perioperative vasospasm of the internal mammary artery may limit its use as a bypass graft. The ability of various vasodilators to inhibit internal mammary artery contraction was investigated with the use of discarded segments of human internal mammary artery not used in coronary artery bypass grafting. Ring segments of human internal mammary arteries were suspended on strain gauges in muscle baths containing 37 degrees C Krebs solution for measurement of isometric tension in vitro. Arterial contraction was stimulated by elevating the extracellular potassium concentration to 70 mmol/L or by exposure to a 10 mumol/L concentration of norepinephrine, and inhibition of contraction by vasodilators was measured. The order of potency to inhibit potassium-induced contraction was as follows: nifedipine > verapamil > nitroprusside > papaverine. At maximal effective doses, nifedipine, verapamil, and papaverine almost completely inhibited potassium-induced contraction, whereas nitroprusside inhibited contraction by only 55%. When norepinephrine was used to contract the arteries, a biphasic relaxation curve was seen with nifedipine, but not with other vasodilator drugs. The order of potency to inhibit norepinephrine-induced contraction was as follows: nifedipine > nitroprusside > verapamil > papaverine. Maximal inhibition of norepinephrine contraction by these vasodilators ranged from 68% to 95%. Nitroglycerin, isoproterenol, and adenosine produced little or no inhibition of internal mammary artery contraction caused by potassium or norepinephrine. Although nifedipine was the most potent vasodilator, papaverine produced the greatest maximal inhibition of both potassium- and norepinephrine-induced contraction of human internal mammary artery.


Synergism between infarct-borne left ventricular dysfunction and cardiomegaly in increasing the risk of coronary bypass surgery. The effect of cardiomegaly on operative and late mortality in patients with left ventricular dysfunction undergoing coronary bypass operation was investigated. The study group consisted of 178 patients whose left ventricular ejection fraction was below 45% and who were operated on from 1978 through 1985. Forty-five patients (group A) had severe left ventricular dysfunction (ejection fraction < 30%) and 133 (group B) had moderate dysfunction (30% > ejection fraction > 45%). Twenty-four of group A (53%) and 54 of group B (41%) patients had cardiomegaly (cardiothoracic ratio on chest x-ray films > 0.5). There were 10 (6%) hospital deaths, four in group A (9%) and six in group B (4.5%). All four deaths in group A and the six deaths in group B were patients who had cardiomegaly. Regardless of the severity of the left ventricular dysfunction, there was no operative death among patients with normal heart size (p < 0.001). Age over 65, bypass time longer than 2 hours, and incomplete revascularization emerged as risk factors. Follow-up ranged from 5 to 13 years (mean 7.8 years). Overall 5-year actuarial survival, including hospital mortality, was 80% +/- 3%. Reduced 5-year survival was observed in patients with cardiomegaly (67% +/- 5% versus 91% +/- 3%, p < 0.05). Five- and 10-year survival of patients from group A with cardiomegaly was 53% +/- 7% and 18% +/- 13%, respectively.


Combined cardiac and abdominal aortic aneurysm operations. The dual operation on cardiopulmonary bypass. Eight patients underwent both cardiac operation and repair of abdominal aortic aneurysm. All had respiratory impairment and significant impairment of left ventricular function, whereas six patients had severe diffuse distal coronary disease. In all patients the cardiac procedure was performed first, and the patients continued to receive cardiopulmonary bypass. Rewarming was not commenced until the abdominal repair was well under way, to protect the vital organs. There were no problems in weaning the patients from bypass, and six of the patients were extubated within 24 hours; one required ventilation for 36 hours. One patient died of colonic infarction complicated by kidney failure without being extubated. Another patient who was initially extubated in 11 hours required reintubation because of poor lung function and eventually died of multisystem organ failure caused by bilateral lower limb ischemia that persisted despite embolectomies. All survivors are well and in New York Heart Association functional class I or II between 3 and 18 months postoperatively. We conclude that for patients considered unfit for abdominal aortic aneurysm operations because of the nature of the cardiac disease, the combined operation with cardiopulmonary bypass is both safe and effective.


The stretched ventricle. Myocardial creep and contractile dysfunction after acute nonischemic ventricular distention. The hypothesis that nonischemic distention of the arrested, flaccid ventricle causes myocardial creep and reduces ventricular contractile force was tested in 16 sheep. Left ventricular volume was calculated from ultrasonic dimension transducers spanning left ventricular major and minor axes and left ventricular wall thickness. Changes in left ventricular volume were plotted against left ventricular pressure, with and without temporary occlusion of both venae cavae before and after nonischemic distention of the continuously perfused, flaccid nonbeating left ventricle arrested with oxygenated, normothermic blood-potassium perfusate. During 12 minutes of cardiac arrest, an apical balloon progressively distended the left ventricle to a peak pressure of 40 mm Hg in 11 sheep using a protocol designed to prevent subendocardial ischemia or mechanical injury. Coronary sinus lactate measurements and myocardial distribution of microspheres confirmed the absence of ischemia in 16 animals. In five control sheep the balloon was inserted but not inflated. Left ventricular volume at zero pressure increased from 5.9 +/- 3.5 to 9.5 +/- 4.4 ml (p < 0.05) after balloon inflation and did not change in the control animals. After maximum distention of the balloon, static left ventricular volumes at identical pressures were significantly greater. After passive distention, the slope of the end-systolic pressure-volume relationship, a measure of contractility, decreased significantly (p < 0.05) from 7.1 +/- 2.8 to 3.5 +/- 1.8 mm Hg/ml and did not change in the control group. Passive distention ("stretching") of the nonischemic flaccid left ventricle thus causes myocardial creep and reduces ventricular contractility.


c-myc and c-myb expression in acute myelogenous leukemia. Monoclonal antibodies and flow cytometry were used to detect the expression of c-myc and c-myb in the bone marrow (BM) and peripheral blood (PB) cells of patients with acute myelogenous leukemia (AML). The expression of neither gene was correlated with the percent blast cells in the BM or PB nor was there a correlation between c-myc and c-myb expression. A wide range of expression of each gene was found within each FAB type of AML. Patients who had a high proportion of leukemia cells expressing c-myb were less likely to respond to remission induction therapy than patients in whom a low proportion of cells expressed c-myb. This association appears to reflect an inverse relationship between the proportion of cells expressing c-myb and the sensitivity of leukemia cells to the killing effects of chemotherapy in vivo. Treatment outcome was unrelated to c-myc expression.


Prolongation by differentiation-stimulating factor/leukemia inhibitory factor of the survival time of mice implanted with mouse myeloid leukemia cells. Mouse myeloid leukemic M1 cells can be induced to differentiate into macrophages by differentiation-stimulating factor (D-factor)/leukemia inhibitory factor (LIF). We examined the effect of D-factor on the survival times of syngeneic mice implanted with two different clones (T-22 and R-4) of M1 cells. D-factor induced differentiation and suppressed DNA synthesis of sensitive T-22 cells but not resistant R-4 cells in vitro. For in vivo experiments, we used recombinant mouse D-factor (rmD-factor) produced in mammalian cells, which is glycosylated and is more stable in vitro and in vivo than unglycosylated rmD-factor produced in Escherichia coli. Treatment with rmD-factor prolonged the survival times of mice implanted with T-22 cells but not R-4 cells.


Use of the polymerase chain reaction to detect hypermethylation in the calcitonin gene. A new, sensitive approach to monitor tumor cells in acute myelogenous leukemia. Based on the recent observations that, in a majority of patients with acute leukemia, the 5' end of the calcitonin gene was hypermethylated and abnormal DNA fragments were observed following HpaII restriction digestion, we have developed a PCR-based method to sensitively detect this abnormal methylation of the calcitonin gene in AML. Applying the concept of competitive PCR, a semi-quantitative correlation was obtained between the amount of hypermethylation and the amount of leukemic cells present. These results suggest that this method will be useful to monitor the amount of tumor cells in bone marrow from patients with AML.


Bleeding complications and coagulopathy in acute leukaemia. Factors and inhibitors of coagulation and fibrinolysis were investigated on admission in 57 patients with acute leukaemia and they were correlated to the occurrence of haemorrhage. Coagulation disturbances were found in 98%. Seventeen of the patients with haemorrhagic symptoms had major bleeding. Severe thrombocytopenia (< 20 x 10(9)/l) was found in 16%. Patients with major bleedings had significantly lower concentrations of prothrombin complex, fibrinogen, protein C and platelets. Low levels of antiplasmin and fibrinogen were characteristic of 'bleeders' with promyelocytic and lymphoblastic leukaemia. We found a positive correlation between vWF:Ag and leukaemic cell count especially in lymphoblastic leukaemia (ks = 0.72). Reduced levels of antithrombin indicated a poorer prognosis.


Role of interleukin 6 in the growth of myeloma-derived cell lines. The role of interleukin 6 (IL-6) in the growth of five multiple myeloma-derived cell lines was characterized. The U266 and RPMI 8226 cell lines demonstrated increased DNA synthesis when cultured with exogenous IL-6, expressed IL-6 cell surface receptors (IL-6Rs) and expressed mRNA for IL-6R. However, these cells did not secrete detectable IL-6 protein, and a neutralizing antibody to IL-6 did not inhibit their growth. Three other myeloma-derived cell lines ARH-77, IM-9 and HS-Sultan did not respond to exogenous IL-6, secrete IL-6 or express cell surface IL-6Rs. The IL-6 responsive cell lines bore late B-cell surface antigens (Ags), CD38 and PCA-1, whereas those lines which were non-IL-6 responsive strongly expressed B1 (CD20) and B4 (CD19) Ags, representing earlier stages in B-cell differentiation. Finally, the two IL-6 responsive cell lines did not express Epstein-Barr virus (EBV) proteins; in contrast, EBV encoded proteins typically expressed during latency could be detected in the three non-IL-6 responsive lines, confirming infection with virus. These studies clarify the heterogeneity observed in the myeloma cell line phenotype and biology and suggest that the U266 and RPMI 8226 cell lines, which express IL-6 cell surface receptors and are IL-6 responsive, may be useful for further study of IL-6 signal transduction in and related IL-6 mediated growth of myeloma in vivo. In contrast, those cell lines which are IL-6-independent provide a model for further study of EBV transformation and IL-6-dependent growth mechanisms in malignancy.


Epidemiology of acute leukaemia in the Cape Province of South Africa. Of 535 consecutive cases of acute leukaemia diagnosed in the Cape Province between 1978 and 1985, demographic data are incomplete in 75 black patients and they have had to be excluded from the spatial analysis. Of the remaining 460 cases, 223 (48.5%) occurred in white patients and 237 (51.5%) in those of mixed ancestry, classified as coloureds according to the Population Registration Act No. 30 of 1950. The average incidence was 2.12, 1.37 and 0.58/100,000 for whites, coloureds and blacks respectively. There was no temporal trend in the incidence of acute leukaemia between the three race groups. The median age for whites was 30 years and for the coloureds was 15 years, which is comparable to the 16 years for the black patients. The two-peak age distribution for leukaemia was seen in the white group, but was absent in the other two groups. This is accounted for by a different distribution in non-lymphoblastic as opposed to lymphoblastic subtypes. Furthermore, there was a disproportionately high frequency of acute progranulocytic leukaemia in the black patients, whereas the white and coloured groups were similar. There was a single, clearly defined macro-scale cluster restricted to white patients in Statistical Region 17 (SR-17). This exploratory study provides the first epidemiologic data for acute leukaemia in the Cape Province. It needs to be extended in order to verify these observations under more controlled circumstances and to seek evidence for some environmental factors that may account for the geographical cluster.


Effects of interleukin 2 on engraftment following autologous bone marrow transplantation (ABMT) in dogs. Beagle dogs were treated with recombinant human interleukin 2 (IL-2) 6 x 10(6) International Units (IU)/day for 7 consecutive days following conditioning with sublethal (200 cGy) or lethal (400 cGy) doses of high-dose rate whole body irradiation (WBI) and reconstitution with 2 x 10(8)/kg autologous bone marrow cells, in order to assess the effect of IL-2 on engraftment. Engraftment of dogs conditioned by lethal doses of WBI was not impaired following treatment with IL-2 6 x 10(6) IU/day. At an RIL-2 dose of 6 x 10(6) and 9 x 10(4) IU/day, enhanced engraftment of autologous bone marrow cells was observed in dogs irradiated with a sublethal WBI dose in comparison with controls not treated by IL-2(p < 0.05). We conclude that therapeutic doses of IL-2 may be safely utilized during hematopoietic reconstitution. Under certain conditions IL-2 may even enhance hematopoietic reconstitution following ABMT.


In vitro purging of clonogenic leukemic cells from human bone marrow by heat: simulation experiments for autologous bone marrow transplantation. In order to apply a simple purging method by heat to autologous bone marrow transplantation (ABMT), we have revaluated the ability to purge clonogenic leukemic cells from the simulated marrow mixture of normal marrow cells and leukemic cell lines (HL-60, Molt-3 and HEL) in vitro by heat, using two different clonogenic assays for normal granulocyte-macrophage progenitors (CFU-GM) and leukemic cell lines. It appeared that in vitro hyperthermia (42 degrees C for 120 min) is able to selectively remove clonogenic leukemic cells from simulated tumor cell-normal marrow mixtures even when leukemic cell concentrations are increased up to 3 x 10(6) cells/ml in vitro, and results in a 4-6 log destruction of clonogenic leukemic cells/ml according to a limiting dilution assay, while leaving half of normal CFU-GM surviving. The hyperthermic purging of clonogenic leukemic cells was not affected in the presence of normal marrow cells in vitro. This high level of clonogenic leukemic cell depletion by heat correlated with that of immunologic and pharmacologic studies. These results suggest that in vitro hyperthermia could be applied effectively and safely for the elimination of residual clonogenic leukemic cells in autologous marrow grafts before ABMT.


Alcohol consumption and risk of leukemia, non-Hodgkin's lymphoma, and multiple myeloma. Population-based case-control interview studies of white men, 578 with leukemia, 622 with non-Hodgkin's lymphoma, and 820 controls from Iowa and Minnesota and 173 with multiple myeloma and 452 controls from Iowa, offered the opportunity to investigate the relationship of these cancers with alcohol consumption. Although drinkers had non-significantly elevated risks for specific subtypes of leukemia (acute lymphocytic leukemia (OR = 3.0), myelodysplasia (OR = 1.6), and other leukemia (OR = 1.5)) and multiple myeloma (OR = 1.3), there were no statistically significant findings and no dose-response gradients with amount of alcohol consumed. Thus, these data suggest that alcohol is not an important contributor to the etiology of lymphatic and hematopoietic tumors.


Influence of high versus low intestinal concentration of gram-negative bacteria and endotoxin on the susceptibility of murine myelopoiesis in bone marrow and spleen to cytostatic treatment with Ara-C. The haematopoietic recovery after i.v. cytarabine was studied in C3H/Law mice as a measure for stem cell susceptibility in relation to the intestinal Gram-negative bacteria (GNB) and endotoxin. Reduction or elevation of GNB and endotoxin was induced by either polymyxin or bacitracin, both non-absorbable antibiotics. Bacitracin caused less suppression of the splenic cellularity after cytarabine, and an advancement of the recovery of femoral nucleated cells. The femoral recovery of CFU-GM exhibited a biphasic pattern. The speed and height of the rebound increase of CFU-GMs were significantly affected by the antibiotics. Thus, (modulation of) the murine intestinal microflora influences the haematopoietic recovery after cytostatic drugs. The mechanisms involved are complex; intestinal endotoxin seems to play a role.


Rapid production of diversity during the progression of a mixed lineage leukaemia. A leukaemia presenting with two morphologically different blast populations failed to respond to either antimyeloid or antilymphoid treatment and showed a rapid clinical progression. Immunophenotyping provided good evidence for two blast populations, one lymphoid and the other lymphoid with granulocyte monocytic markers. Two different gene rearrangements within JH were also observed with band densities corresponding to the sizes of the two blast cell populations. A t(19; 22) translocation was observed in almost all cells at presentation one of which evolved into a subclone, becoming dominant in the terminal phase of the disease. We show here both the clonal evolution and clonal competition that occurred in this leukaemia and suggest that the potential of the tumour stem line for rapidly producing diversity was the reason for the resistance to treatment.


Primary, single, autosomal trisomies associated with haematological disorders. United Kingdom Cancer Cytogenetics Group (UKCCG). The United Kingdom Cancer Cytogenetics Group (UKCCG) collected retrospective data on 73 cases of acquired, single autosomal trisomies associated with haematological disorders, excluding trisomy 8 cases in myeloid conditions and trisomy 12 in lymphoid conditions. The bone marrow and/or blood smear morphology was reviewed in 49 cases. Trisomies for chromosomes 21, 11, 9 and 13 respectively were represented most frequently. Trisomy was not reported for chromosomes 1, 2, 5, 7, 16 or 17 and there was only one case of trisomy 8 in a non-myeloid condition and one case of trisomy 18. Of the 73 patients, 60 had myeloid disorders, 12 had lymphoid disorders and there was one case of acute undifferentiated leukaemia. There was no evidence of predisposing factors involved in the etiology of trisomy associated with haematological disorders.


Flow cytometric analysis of cytokinetics of L3-acute lymphoblastic leukemia/lymphoma. Cell kinetic differences have been described between acute lymphoblastic leukemia with L1 and L2 morphology. We now report cytokinetic and DNA ploidy findings of the rare L3 B-cell leukemia/lymphoma. Flow cytometry analysis of nineteen samples was performed by simultaneous DNA-RNA staining with acridine orange. RNA and DNA indices and cell cycle distributions were calculated. The RNA-index of the G0/G1 cells was 17.9 +/- 8.7 and the number of cells in S phase and S + G2M were 21 +/- 10.6 and 28.0 +/- 13.9 percent respectively. DNA aneuploidy was found in 6/19 (31.6%) and in two cases multiple aneuploid cell lines were observed. DNA aneuploidy and multiple abnormal stemlines adversely affected survival (p less than 0.05), while kinetic parameters did not affect survival (p greater than 0.05). The cytokinetic data are significantly different (S phase and RNA-I; p less than 0.001) than previously reported for the L1 and L2 ALL. Abnormal DNA stemlines were found in cases with no detected cytogenetic abnormalities. This study confirms that L3 ALL is characterized by significantly increased proliferation and provides a means for a flow cytometric identification of this subtype as compared to L1 and L2 ALL.


Maturational stage specific immunoglobulin heavy chain gene rearrangements, determined by D and D upstream region gene structures. In 43 cases of various B-cell lineage tumors, precise gene structures of rearranged immunoglobulin heavy chain (IgH) were studied. By Southern-blot analysis of D upstream (5'D) gene of IgH, biallelic rearrangement structures, D-J or V-D-J, were determined and consequently maturational stage specific IgH rearrangement patterns were investigated. B-precursor ALL cases (especially stage IV of Nadler's criteria) have V-D-J rearranged IgH genes on both alleles. In contrast, most of the mature B-cell malignancies, excluding multiple myeloma, have IgH genotype of D-J/V-D-J. In addition, in case of D-J/V-D-J, the D gene used in D-J joining has been speculated by Southern-blot of D genes. So, these approaches for inquiring precise structures of rearranged IgH genes are supposed to provide new information of lymphocyte differentiation and leukemogenesis.


Relation of 5'-nucleotidase and phosphatase activities with immunophenotype, drug resistance and clinical prognosis in childhood leukemia. Ecto-5'-nucleotidase (ecto-5'NT) catalyzes the extracellular dephosphorylation of nucleotides like IMP. Cytoplasmic 5'NT (cyto-5'NT) and non-specific (e.g. acid- and alkaline) phosphatases (AP) regulate the intracellular degradation of nucleotides. High NT and AP activities might cause a resistance to the thiopurines 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG). We studied the relation between these enzymes and immunophenotype, drug resistance and prognosis in 77 children with acute lymphoblastic leukemia (ALL). Enzyme activities were assessed radiochemically; in vitro drug resistance was measured with the MTT assay. AP activities were higher in T-ALL and B-ALL than in precursor B-ALL. Cyto-5'NT activity was very low in all phenotypes and accounted for a significant proportion of total IMPase activity only in the very immature CD10- c mu- precursor B-ALL. CD10+ ALL cases with high ecto-5'NT activities showed a trend (p = 0.065) for a lower probability of continuous complete remission than those with a low activity. Ecto-5'NT activity was not related to in vitro drug resistance to 6-TG. A weak correlation was found between in vitro 6-TG resistance and cyto-5'NT and AP activities. We conclude that high ecto-5'NT activities do not cause a resistance to 6-thiopurines in childhood ALL. Some patients have high cyto-5'NT and AP activities associated with 6-thiopurine resistance.


Induction of permanent regression of Friend virus (FV) leukemia by adoptive transfer of T helper and not T cytotoxic cells. Friend virus (FV) induces a progressive erythroleukemia that can be made to permanently regress by the transfer of in vitro cultured virus-specific T cells (CTL/RFB) without any other adjunctive treatment. To determine the role of T cells in regression, CTL/RFB were enriched for specific T-cell subsets by treatment with monoclonal anti-Lyt2.2 or anti-L3T4 antibody and complement (C'). Pre-treatment of CTL/RFB with anti-Lyt2 antibody and C' did not affect permanent regression incidence, while CTL/RFB depleted of L3T4+ cells induced temporary regressions with all mice recurring. The number of splenic Lyt2+ (CD8+ equivalent) cells was constant irrespective of the leukemic status of the animals. However, the number of L3T4+ cells (CD4+ equivalent) in leukemic mice was three-fold lower than that of normal mice with regressed mice demonstrating a 30% increase in the number of L3T4+ cells compared to normals. Spleen cells from leukemic animals were also unable to produce IL-2 in response to mitogen stimulation. These results indicate that L3T4+ cells are involved in regression of erythroleukemia.


Production of a negative regulator of IL-3 by bone marrow cells in response to the supernatant of IL-3-producing STIL-3 leukemia cells. When spleen cells of mice grafted with STIL-3 C5 cells, a leukemic T-cell line producing IL-3, are cultured in vitro, a high IL-3 activity is detectable in the culture supernatant. However, when bone marrow cells of the same grafted mice are cultured under similar conditions, hardly any IL-3 activity is detectable. To elucidate the mechanism of this difference, we examined whether the bone marrow cells either suppress IL-3 production by STIL-3 C5 cells or produce an IL-3 inhibitor. When STIL-3 C5 cells were cultured in the presence of normal bone marrow cells, the culture supernatant showed a significantly reduced IL-3 activity as assessed by growth stimulatory effects on IL-3-dependent DA-1 cells and mast cells. The conditioned medium (CM) did not inhibit the growth of IL-3-independent cell lines. Heat treatment of the CM resulted in a recovery of the IL-3 activity, indicating that the effect was mediated by a heat-labile inhibitor rather than by suppression of IL-3 production. CM of bone marrow cells alone did not inhibit the IL-3 activity. The inhibitor was produced by a stem cell-enriched fraction of the bone marrow, and not by fractions of T cells, granulocytes, or adherent cells including macrophages. Stimulation of the stem cell-enriched fraction of bone marrow with STIL-3 C5-CM also induced the production of the IL-3 inhibitor, which was recovered in a MW 50-100 kD fraction after ultrafiltration. These results suggest a possible presence of a feedback mechanism against the IL-3 effect on hemopoietic stem cells and progenitors in the bone marrow.


Analysis of chronic lymphoid leukaemias according to FAB. We have studied the immunophenotypic features in patients with chronic lymphoid leukaemia and investigated the suitability of classification according to guidelines of the French-American-British (FAB) group. Immunophenotyping was carried out on cytocentrifuge preparations of mononuclear blood leukocytes using the alkaline phosphatase-antialkaline phosphatase (APAAP) method. The 114 leukaemias, including 58 cases of B-chronic lymphocytic leukaemia (B-CLL), 3 Waldenström's macroglobulinaemia, 6 prolymphocytic leukaemia (B-PL), 13 B-CLL/PL, 4 B-CLL of mixed cell type, 8 splenic lymphoma with villous lymphocytes (SLVL), 8 hairy cell leukaemia (HCL), two HCL variant, three leukaemic phase of follicular lymphoma, two leukaemic phase of intermediate lymphoma, two plasma cell leukaemia and two chronic T-cell leukaemia, were investigated. The 111 of 112 B-chronic lymphoid leukaemias (B-CLL + B-PL + B-CLL/PL + SLVL + HCL etc.) showed monotypic light chains. The antibody HML1 was highly specific for HCL. The antibodies CD11c and CD25 were positive in all HCL cases, but were not specific for this disease. CD5 positivity and CD22s negativity were found in most patients with B-CLL, B-CLL/PL and B-CLL of mixed type. This marker type has a limited value for differentiation from the other chronic lymphoid leukaemias. We also studied three patients with chronic lymphoid leukaemia which were not described by the FAB classification. We conclude that a study of the morphology of the leukaemic cells was the most useful basis for the diagnosis of these leukaemias, whereas immunotyping was apparently valuable only in individual cases.


The effects of microtubule disrupting drugs on the differentiation of HL-60 leukemia cells. We and others have previously shown that microtubules (MT) are stained more intensely and are organized differently in differentiating leukemia cells. To study the effects of the MT disrupting drugs, colchicine (Coln) and vincristine (VCR), on the maturation process, HL-60 leukemia cells were pretreated with Coln or VCR for 1 h and then exposed to either retinoic acid (RA) or dimethyl sulfoxide (DMSO). Neither Coln nor VCR induced the differentiation of HL-60 cells, but in combination with RA increased the percentage of nitroblue tetrazolium-positive cells, the expression of the mature myelocyte surface marker Mo 1, and the content of MT over the effects produced by RA alone. In contrast, pretreatment with Coln or VCR delayed the commitment to a differentiation pathway induced by DMSO. The supra-additivity exhibited between Coln and RA required the administration of Coln prior to RA; thus, Coln had no effect when given two days after the cellular exposure to RA. The findings suggest that (a) a combination of non-cytotoxic concentrations of Coln or VCR with RA may have clinical utility as inducers of leukemia cell maturation, and (b) MT may be involved in modulating signal transduction during the initiation of HL-60 cell differentiation.


No correlation between site of breakpoint in the BCR gene and platelet counts in Philadelphia chromosome-positive CML. In chronic myelogenous leukemia (CML) malignant cells are characterised by the Philadelphia chromosome (Ph), resulting from a translocation t(9;22). The position of the breakpoint within the major breakpoint cluster region (M-bcr) on chromosome 22 has been shown to correlate with the clinical course of the disease or, more recently, thrombopoietic activity. We have therefore determined the breakpoint localisation in 53 Ph-positive CML patients. Following the 5'/3'-region definition of Inokuchi et al. Leukemia Research 15, 1067 (1991) [1], 22 of our patients have 5' and 31 of our patients have 3' orientated breaks. No correlation was found between platelet counts and breakpoint localisation.


Molecular analysis of a HTLV-IpX defective human adult T-cell leukemia. Fresh and cultured leukemia cells from an adult T-cell leukemia (ATL) patient which possessed gag and env gene defective human T-cell leukemia virus type I (HTLV-I) provirus genome were molecularly analyzed. Cells from both fresh and the established cell line, named KB-1 showed identical surface markers of helper T cells, expressed the interleukin 2 (IL-2) receptor and had an identical defective HTLV-I provirus genome with deletions of the gag and env genes involving pX gene exon 2. The KB-1 cells grew vigorously in vitro, even in the absence of IL-2 and the culture supernatant of KB-1 contained a large amount of IL-2. Neither pX mRNA nor p40(TAX) protein was detected in the KB-1 cells. The collective evidence suggests that the pX gene was not functioning in this particular ATL case. The biological function of the HTLV-I genes, especially the pX gene is discussed in relation to the early and late leukemogenesis of ATL.


Electron microscopical demonstration of horseradish peroxidase by use of tetramethylbenzidine as chromogen and sodium tungstate as stabilizer (TMB-ST method): a tracing method with high sensitivity and well preserved ultrastructural tissue. Until now methods using tetramethylbenzidine (TMB) for electron microscopy (TMB-EM methods) are all unable to provide a maximum demonstration of transported horseradish peroxidase (HRP) while maintaining good ultrastructural tissue preservation. In order to solve this problem, we have attempted to adapt a newly developed, highly sensitive TMB method using sodium tungstate (ST) as the stabilizer (TMB-ST method) for HRP electron microscopic retrograde and anterograde fiber tracing. The present study shows that the TMB-ST method combined with diaminobenzidine-cobalt (DAB-Co) is more sensitive than existing TMB-EM methods and that ultrastructural details are well preserved with this combined method. The resultant reaction product complex after osmication is stable and is observed as characteristic crystal-like structures which are extremely electron dense and often aggregated into clumps. In contrast, the TMB-ST method without the DAB-Co step frequently produces a moderate electron-dense reaction product. Therefore, we recommend the TMB-ST method combined with DAB-Co for HRP electron microscopy.


Open fetal spinal cord surgery in rats with low mortality achieved by prevention of oligohydramnios. Myelotomies were performed with an open microsurgical technique in rat fetuses aged between E16 and E18. In 87 consecutively treated fetuses the net surgical mortality was as low as 7%. The cause of death due to fetal surgery is shown to be amniotic fluid loss. The high survival rate is attributed to the prevention of oligohydramnios. The technique is described in detail and the results are discussed.


A non-surgical technique for accurate intracerebral injections in rat. An improved technique for intracerebral injection into rats is described. This technique uses a metallic skull template as an injection aid, aligned with the maxillary incisors, the eyes and the outer ear canals of anesthesized animals. With this device we have been able to target brain structures as small as 4 mm3 both rapidly, accurately and reproducibly. The new method provides a useful alternative to common stereotaxic techniques for rats up to 300 g.


Combining in vivo volume-controlled pressure microejection with extracellular unit recording. We report a method for combining extracellular single-unit recording with pressure ejection, permitting microvolume quantification through the measurement of meniscus movement. Good optimization of both high quality recording and precise determination (in the nanoliter range) of the pressure-ejected volume can be obtained by using a recording electrode affixed to a calibrated, narrow inner diameter ejection pipette.


An in vitro preparation of the mudpuppy for simultaneous intracellular and electromyographic recording during locomotion. In this report we describe the development of an in vitro preparation of the mudpuppy (Necturus maculatus) used to investigate locomotion in walking vertebrates. The preparation consists of the first 5 segments of the cervical spinal cord and the attached forelimb. The preparation is bathed in a cooled (15 degrees C) and oxygenated spinal cord Ringers solution and remains viable for 36-100 h. Locomotion can be elicited during the first 36-48 h by applying the excitatory amino acid N-methyl D-aspartate (NMDA) to the bath. Cutaneous and dorsal root reflexes remain unchanged for much longer periods of time (72-100 h). During locomotion, intracellular recordings can be made from interneurons and motoneurons while simultaneous electromyographic (EMG) recordings are made from forelimb muscles. Rhythmically active interneurons can be classified according to their phase of activity during the step cycle. Further classification of interneurons involves both monitoring the afferent input to these cells from dorsal root and cutaneous afferents as well as using their action potentials as a trigger for averaging the ongoing locomotor EMG activity. In this way some of the input and output characteristics of the interneurons can be monitored. The ability to record simultaneously from interneurons and muscles offers distinct advantages over current in vitro preparations.


An empirical test for the reliability of quantal analysis based on Pascal statistics. We have previously shown that amplitude distributions of excitatory postsynaptic potentials (EPSPs) can be better described by Pascal distribution when the mean quantal content (m) is not stationary but fluctuating according to gamma distribution. We have developed the procedure of estimating quantal parameters by the method of maximum likelihood. In this study, we examined empirically the reliability of this quantal parameter estimation procedure by using Monte Carlo simulations. The reliability was evaluated by absolute values of error (magnitude of error) of estimated parameters relative to the known 'true' parameters. The mean values of relative magnitude of error were relatively small unless the probability of failures was too large (greater than 0.7) or too small (less than 0.1). The values of relative magnitude of error became smaller in association with increases in the sample size. When the probability of failure was between 0.1 and 0.7, the sample size was 1000, coefficient of variation of quantal size was 0.45, the values of relative magnitude of error of estimated parameters were below 0.1. These results mean that this procedure gives relatively reliable estimates of quantal parameters with the limitation that the probability of failure is neither too large (greater than 0.7) nor too small (less than 0.1); it is preferable that the sample size is as large as 1000.


A simplified approach to retrograde/anterograde axonal labeling using combined injections of horseradish peroxidase and ibotenic acid. Combined injections of ibotenic acid and horseradish peroxidase (HRP) were made into the region of the mouse ventrobasal thalamus that is related to the large mystacial vibrissae. Examination 4 and 5 days later of the corresponding area of the primary somatosensory cortex (i.e., barrel cortex), in thick and in thin sections, showed it to contain numerous corticothalamic projection cells the somata, dendrites and axons of which were densely labeled by the retrograde transport of HRP. Analysis of serial thin sections showed that thalamocortical axon terminals, which had degenerated in response to the injection of ibotenic acid, formed approximately 20% of the asymmetrical synapses in barrel cortex. The fine structure and distribution in cortex of degenerating thalamocortical axon terminals and of intrinsic HRP-labeled corticothalamic axon terminals were identical to those reported in previous studies in which the injection of HRP into the thalamus was combined with the making of electrolytic lesions. This indicates that injecting ibotenic acid is an effective replacement for electrolytic lesioning of the thalamus. The combined injection of ibotenic acid and HRP represents a new and efficient approach for studying reciprocal projection pathways.


Brain tissue slice thickness monitored by ion-profile measurement. The thickness of a brain tissue slice preparation governs the amount of time required for substances to diffuse from the bathing solution to preparation. Slice thickness may increase during the experiment, e.g., in cases of hypoxia where osmotic pressure within the tissue changes, enabling water to enter the preparation. With increasing slice thickness diffusion paths from the bath to central layers of the preparation increase possibly resulting in an insufficient O2 supply to central layers. Therefore, the actual slice thickness should be monitored during the experiment especially in cases where osmolarity is changed or during hypoxia. This paper describes a simple method to monitor the actual slice thickness using ion profiles measured by ion selective micro-electrodes driven at a constant rate of approximately 10 microns/s (sample rate ca. 10/s). The method is based on steep changes in the concentration gradients at the upper and lower surfaces of the preparation induced by simple diffusion in the presence of concentration gradients between the non-tortuous bath and the tortuous tissue. The thickness of the preparation is derived from the location of the steep gradient changes as reflected by the registered profile.


Polyacrylamide as an infiltrating and embedding medium for vibratome sectioning of human fetal cerebellum containing DiI-filled axons. Polyacrylamide is widely used for the separation of proteins by electrophoresis. Here the usage of polyacrylamide as an infiltrating and embedding medium for vibratome sectioning of human fetal cerebellum containing DiI-filled axons is reported. The procedure is simple to implement and has several advantages: it does not require prior dehydration and clearing of tissue; it can be carried out at a low temperature of 4 degrees C; and the polyacrylamide neither dissolves the DiI nor does it interfere with the visualizing of DiI-filled profiles under fluorescence microscope.