Immunophenotypic analysis of peripheral blood and bone marrow in the staging of B-cell malignant lymphoma.

This study evaluated the contributing roles of flow cytometric immunophenotyping of blood and bone marrow and immunohistochemical paraffin section staining of bone marrow biopsies in the staging of B-cell malignant lymphoma. Flow immunophenotyping was performed on a marrow specimen in 175 cases; a corresponding blood specimen was also immunophenotyped in 135 of these cases. Morphologic marrow involvement by lymphoma was found in 59 cases; flow immunophenotyping identified 54 cases with a monoclonal B-cell process: morphology-positive/flow-positive (n = 49), morphology-positive/flow-negative (n = 10), morphology-negative/flow-positive (n = 5), and morphology-negative/flow-negative (n = 111). The 10 morphology-positive/flow-negative cases included 5 follicular and 5 large-cell lymphomas with minimal marrow involvement. All 5 morphology-negative/flow-positive cases were from patients with large-cell lymphomas and bulky clinical disease. Because the blood contained the same B-cell clone in 2 of 2 morphology-negative/flow-positive cases studied, blood contamination of marrow may account for these findings. Blood flow cytometric immunophenotyping studies were positive in 32 cases; 30 had marrow involvement by morphology and were from patients with follicular, mantle cell, lymphoplasmacytic, small lymphocytic, or marginal zone lymphomas. From our results, we conclude that (1) bone marrow flow cytometric immunophenotyping is not a cost-effective replacement for good morphologic evaluation in lymphoma staging and that (2) a positive peripheral blood flow cytometric immunophenotyping study when performed in low-grade lymphomas correlates with marrow involvement.

Desensitization of myocardial beta-adrenergic receptors and deterioration of left ventricular function after brain death.

Brain death often results in a series of hemodynamic alterations that complicate the treatment of potential organ donors before transplantation. The deterioration of myocardial performance after brain death has been described; however, the pathophysiologic process of the myocardial dysfunction that occurs after brain death has not been elucidated. This study was designed to analyze the function of the myocardial beta-adrenergic receptor and the development of left ventricular dysfunction in a porcine model of experimental brain death. Analysis of the beta-receptor included determination of receptor density and adenylate cyclase activity after stimulation independently at the receptor protein, the G protein, and the adenylate cyclase moiety. Myocardial beta-receptor density did not change after the induction of brain death. A decrease in stimulated adenylate cyclase activity was observed within the first hour after brain death at the level of the beta-receptor, the G protein, and the adenylate cyclase moiety, which suggests the occurrence of rapid desensitization of beta-receptor function. Significant deterioration of myocardial performance also occurred within the first hour after brain death, represented by a decrease in preload-recruitable stroke work compared with the baseline value. The deterioration of myocardial performance after brain death correlates temporally with desensitization of the myocardial beta-receptor signal transduction system. The mechanism of impairment appears to be localized to the adenylate cyclase moiety itself.

Management of biliary complications after heart transplantation.

BACKGROUND: Immunosuppression increases the risk of biliary complications in heart transplant recipients. METHODS: Patients undergoing heart transplantation since 1986 who were at risk for cholelithiasis (n = 60) were retrospectively studied. RESULTS: Cholestatic jaundice developed in all patients after the operation because of biliary obstruction from cholelithiasis, cyclosporine toxicity, Imuran toxicity, or Gilbert's disease. The incidence of cholelithiasis or sludge was 42% (n = 25 of 60). Gallstones developed within 1.8 +/- 1.1 years in 17% of patients (n = 8 of 48) with a normal pretransplantation ultrasonogram. Biliary colic or gallstone pancreatitis developed 2 +/- 1.2 years after transplantation in 58% of patients (n = 7 of 12) with asymptomatic gallstones diagnosed before transplantation. The overall incidence of cholecystectomy or cholecystectomy with Roux-en-Y cystojejunostomy was 40% (n = 24). Both open cholecystectomy (n = 5) and laparoscopic cholecystectomy (n = 19) were performed without significant complications. Recovery is significantly more rapid (p < 0.05) after laparoscopic cholecystectomy versus open cholecystectomy (1 week versus 3 weeks). CONCLUSIONS: This analysis indicates that transplant candidates who have gallstones on pretransplantation evaluation or in whom gallstones develop after transplantation should undergo laparoscopic cholecystectomy at the earliest time in their posttransplantation course (i.e., 3 months) regardless of their symptomatic status. Removal of the diseased gallbladder not only simplifies the evaluation of cholestatic jaundice by eliminating the need for multiple ultrasonograms to exclude acute cholecystitis or choledocholithiasis but also safely minimizes the risk of the development of severe biliary complications.

Load-independent analysis of a pulsatile right ventricular assist device.

BACKGROUND: Right ventricular assist devices are becoming increasingly used as both a bridge to heart transplantation and as a means of temporary support after cardiopulmonary bypass. There has also been a resurgence of interest in pulsatile devices fueled by anecdotal, clinical reports. However, a load-independent analysis of biventricular function after right ventricular assistance comparing a pulsatile versus a continuous-flow right ventricular assist device has not been performed, and we hypothesize that a pulsatile device is less detrimental to cardiac function than a conventional, nonpulsatile pump. METHODS: Sixteen dogs (20 to 25 kg) were instrumented through a median sternotomy for placement of left ventricular and right ventricular epicardial dimension transducers in the major, minor, and septal-free wall axes. Intracavitary micromanometers were placed in both ventricles as well. Baseline pressure-dimension data were collected, and the right atrium and pulmonary artery were cannulated. Right ventricular bypass with the use of a pneumatically driven pulsatile right ventricular assist device (SV = 60 ml; n = 7) or a conventional continuous-flow centrifugal right ventricular assist device (n = 9) was instituted for a 4-hour duration. Animals were then weaned from right ventricular support and decannulated. After bypass, biventricular function data were then collected. The load-insensitive stroke work-end diastolic volume relationship known as preload recruitable stroke work was derived and expressed as a fraction of baseline function along with conventional hemodynamic indexes, cardiac output, and pulmonary vascular resistance. RESULTS: Results of this analysis show no significant benefit to either right ventricular or left ventricular function (right ventricular preload recruitable stroke work index: 0.863 +/- 0.3 [pulsatile] versus 0.849 +/- 0.2 [continuous], left ventricular preload recruitable stroke work index: 0.880 +/- 0.4 [pulsatile] versus 0.821 +/- 0.3 [continuous] after pulsatile right ventricular support. Likewise, cardiac output (1.4 +/- 0.1 [pulsatile] versus 1.5 +/- 0.2 [continuous] L/min) and pulmonary vascular resistance (4.8 +/- 1.0 [pulsatile] versus 3.2 +/- 1.1 [continuous] Wood Units) were not significantly different in either study group. CONCLUSIONS: We conclude from these data that pneumatically driven pulsatile right ventricular assist devices provide no additional benefit to myocardial performance beyond that of conventional, nonpulsatile pumps. Further studies investigating a speculative benefit from pulsatile circulatory support are necessary to further define a potential role for these novel devices.

Stability of the beta-adrenergic receptor/adenylyl cyclase pathway of pediatric myocardium after brain death.

Our previous work in the adult porcine model shows that brain death results in a rapid decline in left ventricular systolic function as measured by the preload recruitable stroke work method to 8% of the baseline slope within 6 hours; this process is accompanied by functional uncoupling of the beta-adrenergic receptor at the level of the adenylyl cyclase moiety within 1 hour. In contrast, the pediatric porcine myocardium displays no change in left ventricular systolic function from baseline within 6 hours of brain death. This work investigates whether the beta-adrenergic receptor/adenylyl cyclase pathway remains intact after induction of brain death in the pediatric porcine model. Thirteen 1-month-old swine (7 to 10 kg) were anesthetized and underwent median sternotomy, and baseline transmural left ventricular biopsy specimens were obtained before ligation of head vessels to induce brain death in six piglets, with the remaining seven serving as controls. Baseline left ventricular biopsy specimens were obtained just before and 1 and 3 hours after brain death or at matched time points without brain death in the control group. Myocardial tissue was then analyzed for beta-adrenergic receptor density with the use of saturation [125I]-iodocyanopindolol binding in the absence and presence of propranolol 1 mumol/L. Coupling of the beta-adrenergic receptor to its signal transduction system (stimulation of adenylyl cyclase) was tested at three levels: beta-adrenergic receptor (isoproterenol 100 mumol/L), stimulatory G protein Gs (sodium fluoride 10 mmol/L), and the adenylyl cyclase moiety itself (forskolin 100 mumol/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced cardiac preservation with oxygenated University of Wisconsin solution.

The purpose of this study was to determine if oxygen delivery to rabbit cardiac allografts arrested and stored in University of Wisconsin solution (UWS) at 4 degrees C would affect preservation. Nineteen isolated rabbit hearts were rapidly excised and perfused at 80 mm Hg on an isovolumic modified Langendorff apparatus. A micromanometer was placed within a balloon and inserted into the left ventricle through the mitral valve orifice. Digitized pressure waveforms were collected at 11 known balloon volumes from 0.8 to 1.2 ml. Baseline data were obtained for all hearts while perfused with Krebs-Henseleit solution equilibrated with 95% O2:5% CO2 at 37 degrees C. All hearts were arrested with 30 ml of UWS (290 mOsm). The control group (N = 10) was stored in UWS at 4 degrees C for 8 hr, and the experimental group (N = 9) was perfused with oxygenated UWS (O2 content = 5.6 ml O2) at 4 degrees C for 8 hr at a pressure of 60 mm Hg (5-10 ml/min). Both groups were then reperfused with Krebs-Henseleit buffer at 80 mm Hg for 15 min at for postpreservation data acquisition. Left ventricular developed pressures over a physiologic range (pressure-volume area) and maximum positive and negative dP/dt were calculated. Recovery of left ventricular parameters as a percentage of the baseline values was determined. Mean pressure-volume area recovery in the nonperfused group was 40 +/- 7.9% versus the perfused group (71 +/- 7.0%, P = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Improved tolerance of the pediatric myocardium to brain death.

The occurrence of brain death has been shown to significantly diminish left ventricular function in the adult porcine model. This study examined whether the pediatric myocardium is as sensitive as the adult myocardium to the detrimental effects of brain death in the porcine model. Left ventricular intracavitary pressure and major and minor axis epicardial dimensions were measured in eleven 1-month old pigs (7.5 to 10 kg) during a vena caval occlusion. Brain death was induced in six pigs by acutely ligating the brachiocephalic and left subclavian arteries. The remaining five pigs served as controls. Data were then collected every hour for 6 hours. The plot of the stroke work versus the end diastolic volume, called the preload recruitable stroke work relationship, was determined from the measured pressure and calculated intracavitary volume data. The slope of this linear relationship is an index of contractility, and the x intercept (Vo) is an index of diastolic mechanics. At each hour after instrumentation two vena caval occlusions were performed, and the mean slope of the preload recruitable stroke work line was calculated as a percentage of the baseline slope in both the brain-dead and control group. The mean values from the brain-dead pigs were 118%, 138%, 126%, 154%, 123%, and 87% of the baseline value for the 6 hours after brain death. The mean control values were 128%, 117%, 133%, 123%, 114%, and 111% of baseline for the 6 hours after instrumentation alone.(ABSTRACT TRUNCATED AT 250 WORDS)

The efficiency of pulmonary blood transport following single lung transplantation.

Perioperative right ventricular (RV) dysfunction remains a significant problem following single lung transplantation (SLT), especially in patients with pulmonary hypertension. Total RV power (Wt), a determinant of RV function, is the sum of the mean component (Wm) which contributes to actual blood flow and the oscillatory component (Wo) which is the energy expended on arterial pulsation. Calculation of Wo is possible only through harmonic analysis of pulmonary arterial (PA) pressure and flow waveforms, and as much as 33% of RV power is attributed to it. The purpose of this study was to precisely quantify changes in RV power output using Fourier analysis of PA pressure and flow waveforms after SLT. Fourteen dogs (donors) were instrumented with a PA ultrasonic flow probe, PA and left atrial (LA) micromanometers, and LA epicardial pacing leads. Control (Pre-Tx) pressure-flow data were acquired during transient occlusion of the right PA at a heart rate of 140. The PA was cannulated, the lungs were flushed with 1 liter of modified Euro-Collins solution at 4 degrees C, and the left lung was harvested and transplanted to 14 recipient dogs in a standard manner. After 1 hr of reperfusion, PA (Post-Tx) pressure-flow data were acquired as above. All recipient animals survived SLT with a mean ischemic time of 183 +/- 3 min. Following SLT, both the mean, Wm, (69 +/- 9 to 161 +/- 23 mW) and oscillatory, Wo, (23 +/- 3 to 46 +/- 10 mW) components of RV power output increased significantly after SLT (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of triiodothyronine and vasopressin on cardiac function and myocardial blood flow after brain death.

Previous studies have documented decreases in serum-free triiodothyronine (T3) after brain death and improved hemodynamics with its replacement, suggesting its controversial, but promising, clinical utility for managing potential organ donors. Vasopressin is also commonly used clinically as a pressor agent after brain death. A load-independent analysis of cardiac function and an assessment of myocardial blood flow (MBF) with these agents have not been reported, however. Eighteen pigs were instrumented with left ventricular epicardial dimension transducers and a left ventricular micromanometer. MBF was assessed by standard microsphere techniques. Baseline left ventricular pressure-dimension data were collected, and brain death was induced by ligating the innominate and left subclavian arteries. Left ventricular function data were collected every 30 minutes after brain death to 6 hours or until the animal died. Microsphere injections were performed before brain death and hourly thereafter to 4 hours. At 90 minutes after brain death, animals were assigned to a vasopressin (2 units/hr, intravenously, n = 6), T3 (0.05 microgram/kg/hr, intravenously, n = 6), or control (n = 6) treatment group. Preload recruitable stroke work (PRSW), a load-independent index of left ventricular function, was derived from the pressure-dimension data. MBF was calculated by conventional methods. At 4 hours after brain death, PRSW and MBF decreased significantly in the control, vasopressin, and T3 groups relative to the baseline, pre-brain dead state (PRSW: -36% +/- 12%, -48 +/- 7%, -52% +/- 5%; MBF: -27% +/- 15%, -38% +/- 5%, -78% +/- 2%, respectively). Neither vasopressin nor T3, however, showed any advantage over the control group in terms of preserving left ventricular function or prolonging survival. Furthermore, these data show a marked decrease in MBF in the T3 group (p < 0.01 versus control and vasopressin groups) without a significant change in cardiac function. Analysis of endocardial to epicardial flow ratios disclosed no significant differences between groups at any time. In summary, animals treated with T3 had a greater decline in MBF than the control group at 4 hours, without any benefit to cardiac function. Further studies examining the mechanism responsible for the deterioration of MBF and cardiac dysfunction will be necessary to optimally manage the brain dead patient before organ harvest, especially regarding the precise role of T3.

Pulmonary arterial impedance after single lung transplantation.

Single lung transplantation (SLT) is emerging as definitive therapy for end-stage pulmonary disease of varying etiology, yet a complete description of the hemodynamic properties of the transplanted lung has not been reported. In this study, Fourier analysis was used to calculate the pulmonary arterial (PA) impedance spectrum before and immediately after SLT to define precisely the pulmonary pressure-flow relationship. Median sternotomies were performed in 18 dogs (donors): an ultrasonic flow probe was placed around the PA and micromanometers were placed in the PA and left atrium (LA). Control PA pressure and flow (PAQ) and LA pressure were measured during transient occlusion of the right PA. The lungs were harvested using cold modified Euro-Collins solution for preservation. After thoracotomy and pneumonectomy, left SLT was performed in 18 recipient dogs with a mean ischemic time of 179 +/- 6 min. After reperfusion for 1 hr, PA pressure and flow data were again collected. Characteristic impedance (Z0), a measure of resistance to pulsatile flow, was compared to input resistance (Rin), a measure of resistance to mean flow, and pulmonary vascular resistance (PVR), the conventional index. Rin is defined as the zeroth harmonic of the impedance spectrum and Z0 as the mean of impedance moduli from 2-12 Hz. All recipients survived transplantation. Both PVR and Rin increased significantly after transplantation (11 +/- 1 vs 19 +/- 3 Wood U, P less than 0.05, and 1352 +/- 121 vs 1964 +/- 244 dyne.sec.cm-5, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

The role of bilirubin production in breast-fed infants with elevated serum bilirubin concentrations at 2 weeks of life.

The carboxyhemoglobin level (COHb), an accepted qualitative index of bilirubin production, was measured in normal, full-term, breast-fed (n = 9) or formula-fed (n = 11) infants at 2 days and 2 weeks of life. The mean COHb did not differ significantly at 2 days and 2 weeks in either of the groups, nor did the mean COHb differ between the groups at 2 weeks. The mean serum bilirubin concentration was lower in the formula-fed infants compared to the breast-fed infants at 2 weeks (p less than 0.05). The mean serum bilirubin concentration decreased by only 14 percent among the breast-fed infants, and actually increased in three infants by 2 weeks. In comparison, the mean serum bilirubin concentration of the formula-fed infants decreased by 61 percent (p less than 0.05), with the serum bilirubin concentration decreasing in each infant by 2 weeks. These findings are consistent with the generally held belief that bilirubin production is not the primary etiology of elevated serum bilirubin concentrations associated with breast-feeding in the second week of life. However, continued high bilirubin production at 2 weeks may contribute to the potential for significant jaundice in some infants with impaired hepatic function or increased enterohepatic circulation of bilirubin.