Contrast echocardiography for analysis of heart anatomy in tortoises.

OBJECTIVE: The cardiac anatomy in tortoises depicted on B-mode and color-Doppler should be better differentiated by additional contrast-echocardiography. MATERIAL AND METHODS: An intravenous contrast agent (INN-sulphur hexafluoride [SonoVue®]) was injected in four tortoises (three Testudo hermanni, one Agrionemys horsfieldii), via the coccygeal vein, with parallel B-mode echocardiographic examination. The results of the contrast-enhanced echocardiography were compared with the contrast-free B-mode recordings and color-Doppler ultrasound. RESULTS: The use of SonoVue® enabled clearer distinction of the cardiac structures, differentiation of the arising major arteries, identification of wash-out-shunts, and visualization of blood flow patterns throughout the tortoise heart. CONCLUSION AND CLINICAL RELEVANCE: This study enables the accurate depiction and differentiation of cardiac anatomy in tortoises through the use of a combination of B-mode, color-Doppler and contrast-echocardiography. Basic knowledge of blood flow in the reptile heart is essential to understand echocardiographic anatomy. Blood-flow-patterns and anatomy of the tortoise heart as found in this study will help to establish a basis for further echocardiographic examinations of these animals.

Persistent atrial fibrillation ablation concomitant to coronary surgery.

OBJECTIVE: This analysis was undertaken to evaluate the results of persistent atrial fibrillation (pAF) ablation procedures concomitant to coronary surgery and to identify the risk factors for pAF recurrence. METHODS: Since 2001, a total of 126 consecutive patients with pAF (duration: 0.5-33 years) underwent ablation concomitant to coronary surgery (isolated or in combination with valve surgery), whereby two encircling isolation lesions around the left and the right pulmonary veins and a connecting lesion between both was created using radiofrequency ablation. Patients were reevaluated at discharge, 3 months and 3 years after surgery. RESULTS: Survivals at the time of reexamination were 96.8, 95.1 and 94.7 %, respectively. Stable sinus rhythm (SR) could be documented in 66.4, 75.1 and 75.9 % of surviving patients. Long-term pAF before surgery and a larger left atrium (LA) were predictive of postoperative pAF return ( P < 0.01). Statistical analysis demonstrated a cut-off point of 5 years for pAF and 50 mm for LA diameter: 89.1 % of patients with pAF duration of < 5 years and 86.2 % of patients with LA size of ≤ 50 mm were in stable SR at late follow-up. Cardiac rhythm at 3 months was predictive for long-term rhythm prognosis ( P < 0.01). Age, gender and concomitant diseases (e.g. arterial hypertension, diabetes, renal insufficiency), and the underlying cause of heart disease did not significantly influence the postoperative cardiac rhythm. CONCLUSIONS: The duration of pAF and the LA size are the most reliable preoperative variables to predict the success rate of ablation in patients undergoing coronary surgery. The probability of re-establishing stable SR is excellent when pAF duration is short and LA size is small.

Early and late results of permanent atrial fibrillation ablation surgery in aortic valve and CABG patients.

OBJECTIVE: The study investigates the early and late results of permanent atrial fibrillation (AF) ablation surgery concomitant to coronary artery bypass grafting (CABG) and/or aortic valve (AV) surgery. METHODS: Between February 2001 and April 2006, a selective group of 80 patients with permanent AF (median: 48 months [Perc25/75 24/110; range: 6 - 360 months]) underwent either bipolar (n = 60) or monopolar (n = 20) radiofrequency (RF) ablation procedures concomitant to CABG and/or AV surgery (CABG: n = 39; AV: n = 30; AV + CABG: n = 11). All patients were restudied to assess survival, conversion rate to stable sinus rhythm (SR) and New York Heart Association (NYHA) class early (3 +/- 1 months) and late after surgery (30 +/- 15 months). Data were analyzed exploratively. RESULTS: Survival at 3 and 30 months was 98 % and 96 %, respectively. Stable SR could be documented in 73 % and 77 % of patients. Long-term AF before surgery and larger LA size were predictive for AF return after surgery ( P = 0.004 and P = 0.032, respectively). Neither age, gender, the application modus of the RF energy nor the underlying cardiac disease influenced the postoperative cardiac rhythm significantly. NYHA class improved significantly after surgery ( P < 0.0005), particularly when stable SR was achieved ( P = 0.049). CONCLUSION: Preoperative permanent AF duration time and larger LA size are useful variables to predict the success rate of concomitant ablation surgery in CABG and/or AV patients. Further it could be demonstrated that established SR remained stable over time.

Early and late results of restrictive mitral valve annuloplasty in 121 patients with cardiomyopathy and chronic mitral regurgitation.

OBJECTIVE: This study investigated the early and late results of restrictive mitral valve (MV) annuloplasty in patients with chronic mitral regurgitation (MR) and advanced ischemic (ICM) or dilated cardiomyopathy (DCM). METHODS: From October 2001 to September 2006, 121 patients (age: 69 +/- 9 years) with a left ventricular ejection fraction (LVEF) of 30 +/- 9 % and chronic MR grade 3 - 4 (ICM: n = 102, DCM: n = 19) underwent restrictive prosthetic ring annuloplasty (downsizing of 2.7 +/- 0.8 ring sizes). Eighty-five ICM-patients had indications for concomitant coronary artery bypass grafting (CABG). All patients were restudied at 7 +/- 1 days, 3 +/- 1 and 30 +/- 12 months after surgery to assess survival, residual MR, New York Heart Association (NYHA) class and left ventricular (LV) function (end-systolic/end-diastolic dimensions/volume indexes and LVEF). Data were analyzed exploratively. RESULTS: 30-day mortality was 3.3 %; survival at follow-up was 95 % and 91 %, respectively. Postoperative recurrence of significant MR (> grade 2) was absent in all patients. NYHA class, LV dimensions/volume indexes and LVEF improved significantly after surgery in both groups ( P < 0.0005). A prediction of continuous postoperative improvement of myocardial function in the sense of reverse remodeling could be demonstrated by univariate logistic regression for ischemic etiology and concomitant CABG ( P = 0.0001). In DCM-patients or ICM-patients without CABG, the postoperative benefit on myocardial function was limited. CONCLUSION: Restrictive mitral valve (MV) annuloplasty corrected chronic MR in cardiomyopathy patients with low mortality and improved contractility. Surgery also prevented recurrence of significant MR, although the phenomenon of postoperative continuous reverse myocardial remodeling could not be verified in cases with a non-ischemic etiology or ICM without concomitant CABG.

Ablation surgery failure after combined permanent atrial fibrillation ablation and mitral valve surgery.

OBJECTIVE: The aim of this study was to evaluate the early and late results of a permanent atrial fibrillation (pAF) ablation concept carried out concomitantly with mitral valve (MV) surgery and to identify risk factors for ablation surgery failure. METHODS: Between February 2001 and April 2006, 109 patients with pAF over a median time of 48 months (Perc25/75; range 6 - 396 months) underwent monopolar endocardial radiofrequency ablation procedures concomitantly with MV surgery. All patients were restudied to assess survival, conversion rate to stable sinus rhythm (SR) and New York Heart Association (NYHA) class early (3 +/- 1 months) and late after surgery (36 +/- 19 months). For data assessment an explorative data analysis including univariate and multivariate binary logistic regression was performed. RESULTS: Early and late survival was 95 % and 91 %, respectively; at follow-up stable SR was documented in 76 % (74 %) of patients. NYHA class improved significantly after surgery ( P = 0.009), particularly when stable SR was achieved ( P = 0.042). Among these MV patients left atrial (LA) enlargement and pAF of long-time duration prior to surgery were detected as risk factors for postoperative recurrence and persistence of atrial fibrillation ( P = 0.026 and P = 0.002); furthermore, advanced age and significant tricuspidal regurgitation at the time of surgery were also relevant. The best prediction (95 % of patients) for SR, as demonstrated in a multivariate model, was based on the factors LA size and pAF duration ( P = 0.052 and 0.005). CONCLUSION: Particularly the preoperative LA size and pAF duration seem to be useful parameters to evaluate the success rate of ablation performed concomitantly with MV surgery. It could be demonstrated that an established SR remains stable over time.

Changes of myocardial function after combined coronary revascularization and mitral valve downsizing in patients with ischemic mitral regurgitation and advanced cardiomyopathy.

OBJECTIVE: At present not much data is available on changes in myocardial function after combined coronary artery bypass grafting (CABG) and downsizing of the mitral valve (MV) by restrictive prosthetic ring annuloplasty in patients with chronic ischemic mitral regurgitation (IMR) and advanced cardiomyopathy. METHODS: 63 patients with coronary artery disease, chronic IMR grade 3 - 4+, ischemic cardiomyopathy and reduced left ventricular (LV) function (LV ejection fraction [LVEF] of 30 +/- 9 %; range 12 - 45 %) underwent combined CABG and MV downsizing. Clinical follow-up and serial echocardiographic studies were performed to assess survival, New York Heart Association (NYHA) class, mitral regurgitation (MR), leaflet coaptation height (LCH), left atrial (LA) and LV end-systolic/end-diastolic dimensions/volumes and volume indices (LVESD, -EDD; LVESV, -EDV; LVESVI, -EDVI), fractional shortening (FS) and LVEF to evaluate the changes in myocardial function after surgery. RESULTS: Early mortality (< 30 days) was 1.6 %, survival at follow-up was 95 % (3 +/- 1 months) and 83 % (2 +/- 1 years), respectively. Functional class improved significantly after surgery; recurrence of relevant MR was absent in all patients. In general, LA/LV dimensions/volumes and volume indices, FS and LVEF improved significantly, even in patients with already severely reduced preoperative LV function (LVEF

Permanent atrial fibrillation ablation surgery in CABG and aortic valve patients is at least as effective as in mitral valve disease.

BACKGROUND: Data on combined permanent atrial fibrillation (pAF) surgery and coronary artery bypass grafting (CABG) and/or aortic valve replacement (AVR) are scarce, and the mid- and long-term effects on survival and cardiac rhythm are unknown. MATERIAL AND METHODS: In a prospective analysis 125 patients (Group I: CABG and/or AVR, n = 50; Group II: mitral valve [MV] surgery, n = 75) with pAF (> or = 6 months) underwent either concomitant monopolar (Group I: n = 20; Group II: n = 75) or bipolar (Group I: n = 30) radiofrequency (RF) ablation procedures. Group I patients had a significantly smaller left atrial (LA) size than Group II patients (LA-diameter: 47.7 +/- 4.6 vs. 58.2 +/- 6.1 mm; p < 0.01). Regular follow-up was performed from 3 to 36 months after surgery to assess survival, NYHA-class, and conversion rate to stable sinus rhythm (SR). RESULTS: Early mortality (< 30 days) of Group I patients was 0% (Group II: 2.7%), cumulative survival at long-term follow-up was 0.95 vs. 0.82 (p = 0.31) and NYHA-class improved significantly in both groups, particularly in cases with stable SR. At follow-up 80% of Group I patients had SR (Group II: 70%). In Group I patients the bipolar approach was associated with significantly shorter ablation procedure times compared to the monopolar procedure (12.1 +/- 3.4 vs. 18.9 +/- 1.6 min; p < 0.05). CONCLUSIONS: Concomitant pAF ablation surgery in CABG and/or AVR is safe and at least as effective as in MV surgery, presumably because severe LA enlargement is exceptionally rare in this group.

[Papillary fibroelastoma of the aortic valve--a rare cause of thromboembolic cerebral infarct]. / Papilläres Fibroelastom der Aortenklappe--Eine seltene Ursache für einen thrombembolischen Hirninfarkt.

We report on a case of papillary fibroelastoma of the aortic valve in a 55 year old female patient, who had thrombembolic complications and subsequent stroke. The tumor was resected without disturbing the structure and function of the aortic valve.

Re-graft patency and clinical efficacy of aprotinin in elective bypass surgery.

To investigate possible influence of aprotinin on graft patency, a randomized, double-blind group comparative study was carried out in male patients selected for primary bypass surgery. One hundred and ten patients received either placebo treatment or aprotinin according to the Hammersmith Hospital regimen(n = 55 per group). Graft patency was evaluated by angiography in 44 aprotinin and 35 placebo patients between the 18th and 35th day postoperatively. There was no difference in overall graft occlusion. Among the aprotinin patients, 73% (32/44) hsd grafts patent compared with 71% (25/35) of the placebo group. Graft occlusion was not accompanied by signs of myocardial infarction in any case. Blood loss within 6 h postoperatively was reduced by 58.5% in the aprotinin group (P < 0.001). of these patients 51% (26/51) did not need donor blood compared with 21% (10/47) of the placebo patients (P = 0.003). Mean transfusion requirements per patient were 1.1 and 2.7 units in the aprotinin and placebo groups, respectively.

Aprotinin in elective primary bypass surgery. Graft patency and clinical efficacy.

The proteinase inhibitor aprotinin is used in open heart surgery to reduce intraoperative and postoperative blood loss and transfusion requirements. To investigate a possible influence on graft patency, a randomized double-blind group comparison study was carried out in male patients elected for primary bypass surgery. One hundred ten (55/55) patients received either placebo treatment or aprotinin according to the Hammersmith scheme (2 Mio KIU as loading dose before sternotomy, followed by an infusion of 0.5 Mio KIU/h until the end of surgery; 2 Mio KIU added to the priming volume additionally). Graft patency was evaluated by angiography in 44 aprotinin and 35 placebo patients between the 18th and 35th days postoperatively. There was no difference in the overall graft occlusion: in the aprotinin group 89.5% (111/124) grafts were found patent compared to 87.2% (89/102) in the placebo group. Of the aprotinin patients 72.7% (32/44) and 71.4% (25/35) of the placebo patients had all grafts patent. Venous grafts were occluded in 16% (7/44) of aprotinin patients and in 29% (10/35) of placebo patients. On the other hand 5/27 patients in the aprotinin group vs 0/27 in the placebo group had occluded internal mammary artery (IMA) grafts (P = 0.0511%). Graft occlusions were not accompanied by signs of myocardial infarction in any case. Fifty-one patients in the aprotinin group and 47 patients in the placebo group were valid for parameters of clinical efficacy: blood loss within 6 h postoperatively was reduced by 58.5% in the aprotinin group (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Comment: population and development.

PIP: The 1994 International Conference on Population and Development (ICPD) was held to assess global population trends and explore solutions consistent with development priorities, national laws, religions, ethical values, and cultural values of the countries attending. The final document adopted at the end of the conference reflects a growing awareness that population issues are inextricably linked to human development concerns, including the alleviation of poverty, the empowerment of women, and the protection of the environment. Transforming the laudable objectives of the conference into reality is, however, a far more daunting challenge than the already difficult establishment of the conference document. Indeed, resolutions made at the conference can be readily substituted for action and invite delay. Danger therefore exists that conferences such as the 1994 ICPD may help lull the general public into a sense of false security that something is truly being done to solve the problems addressed, when nothing has really been put into motion. Changes recommended by the ICPD will ultimately be extremely difficult to achieve given the social, economic, and political revolution of global scale which they would require.^ieng

Influence of intravenous calcium gluconate on saphenous vein graft flow in closed-chest patients.

The effects of calcium gluconate on hemodynamics and saphenous vein graft flow in a group of patients undergoing elective coronary artery bypass grafting who developed ionized hypocalcemia at the end of the surgical procedure were examined. The patients received a central venous bolus of 15 mg/kg of calcium gluconate. Heart rate (HR), arterial pressure (AP), central venous pressure (CVP), pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), and cardiac output were measured immediately before and 30, 60, 120, 180, and 240 seconds after injection of calcium gluconate. Systemic and pulmonary vascular resistance (SVR and PVR, respectively), cardiac index (CI), stroke volume index (SVI), and right and left ventricular stroke work index (RVSWI and LVSWI, respectively), were calculated. Venous bypass flow velocity (Vbypass-flow) was assessed using a Doppler probe that was attached to the left anterior descending artery (LAD) bypass intraoperatively. Calcium gluconate significantly increased MAP, SVR, and LVSWI from 67 +/- 3 mmHg (mean +/- SEM), 1,128 +/- 128 dyne.s.cm-5 and 25 +/- 3 g.m.beat/m to a maximum of 81 +/- 5 mmHg (P < 0.01), 1,401 +/- 196 dyne.s.cm-5 (P < 0.05), and 32 +/- 4 g.m/beat/m (P < 0.01), respectively. HR, CVP, PAP, PCWP, PVR, CI, SVI, and Vbypass-flow remained unaltered. It is concluded that calcium gluconate administered to moderately hypocalcemic patients increases arterial pressure mainly by peripheral vasoconstriction. Because the increase of arterial pressure, and, thereby, coronary perfusion pressure is not associated with an increase of LAD bypass flow, vasoconstriction in the coronary vascular bed distal to the venous graft cannot be ruled out, and deterioration of the myocardial oxygen supply/demand ratio is strongly suggested.

[Perioperative endothelin, ACTH and cortisol plasma concentrations in coronary bypass patients]. / Perioperative Endothelin-, ACTH- und Kortisolplasma- konzentrationen bei Koronarbypasspatienten.

STUDY OBJECTIVE: To follow up endothelin (ET), adrenocorticotropic hormone (ACTH), and cortisol levels in patients undergoing aortocoronary bypass grafting (CABG) and to determine whether these are extracted from plasma by the pulmonary circulation. DESIGN: Convenience sample trial. SETTING: University hospital. PATIENTS: Eight male routine CABG patients without appreciable concomitant disease. INTERVENTIONS: Patients were given anaesthesia in a strictly standardised manner using etomidate, flunitrazepam, fentanyl, and pancuronium. Nitroglycerin was administered prior to cardiopulmonary bypass (CPB) at 2 mg/h and dopamine as the only catecholamine starting from CPB weaning until the end of sampling at 3.5-5 micrograms/kg.min. Samples were drawn in rapid sequence from cannulated radial and a distal pulmonary arteries (Swan-Ganz catheter) at eight sampling times starting after induction of anaesthesia and catheter placement and finishing 22 h after the end of operation. MEASUREMENTS AND RESULTS: ET levels were determined by an ET-1, 2, 3-sensitive radioimmunoassay (RIA), ACTH and cortisol by commercially available RIA kits. There was significant (P = 0.032, linear regression analysis) correlation between ET and cortisol from pulmonary arterial samples. ET was significantly (P = 0.042, two-tailed Wilcoxon test) extracted by the pulmonary circulation after induction of anaesthesia. This pulmonary-systemic arterial difference nearly disappeared intraoperatively, but tended to be restored 22 h after the end of operation at an approximately twofold increased level. CONCLUSIONS: No interrelation between ET and the hypothalamic-pituitary-adrenal axis could be established by the ET, ACTH, and cortisol plasma levels. However, the significant correlation between perioperative ET and cortisol lends further support to the hypothesis of ET release by cortisol from vascular smooth-muscle cells. There is a net pulmonary clearance of ET in patients prior to CABG that is lost intra- and early postoperatively, but tends to be restored on the 1st day thereafter at an increased level.

Effects of vasoactive drugs on postoperative coronary bypass flow: a new technique.

OBJECTIVE: This study aimed to investigate the influence of vasoactive drugs, including a calcium channel blocker, nitroglycerine, and a beta-blocker, often used after coronary artery bypass grafting (CABG). Measurements were taken using a new, completely implantable, mini-Doppler system. The probes were implanted during CABG, led outside through the thoracic wall, and removed 3 days after the operation by a simple pull. RESULTS: The mean Doppler flow increased dramatically in the calcium channel blocker and the nitroglycerine groups (P = 0.002) and decreased slightly in the beta-blocker group (P = 0.015). Mean arterial pressure decreased significantly in all three groups. Heart rate decreased in the beta-blocker group (P = 0.002). Changes in the other hemodynamic variables measured were not significant; there were no changes in the control group. Doppler sonographic monitoring of bypass diameters did not show any changes. CONCLUSION: This is the first study to measure the influence of vasoactive drugs directly and online after CABG. From our experience of more than 40 implantations, we conclude that our method is easy to use and reliable and will help improve the therapeutic regimen for patients after CABG.

A new experimental approach for monitoring postoperative bypass patency after coronary artery bypass grafting.

Little information is known concerning hemodynamic parameters of bypass grafts after open heart surgery during the postoperative period. As there is no easy to use bedside-method for monitoring, we developed a new implantable Doppler probe to measure blood flow velocity with a 20 MHz pulsed Doppler system. The accuracy of this method was proved in a circulatory model and in animal studies. Our conclusion is that the implantable pulsed Doppler system is a sensitive method for monitoring small vessel hemodynamics.

[Heart injury. Description of a traumatologic heart surgery patient sample]. / Herzverletzung. Beschreibung eines traumatologisch-herzchirurgischen Krankheitsguts.

Thoracic injuries can always involve cardiac structures. If the heart is affected, penetrating or blunt injuries need urgent treatment. An unstable cardiac situation with shock symptoms is life-threatening. The diagnostic method of choice is ultrasound examination. This can show pericardial effusion, enlargement of cardiac chambers, wall motion changes and intracardiac defects. Pathologic ultrasound and ECG findings or abnormal enzyme values arising after blunt traumas need intensive care monitoring. Surgical interventions should be done immediately by the first surgeon involved: time should not be wasted by sending patients to special units, as extracorporal circulation is seldom needed. If it is necessary treatment should be carried out by a cardiac surgeon. Between 1989 and 1990 seven patients with thoracic trauma and heart involvement were operated on at the University of Ulm. The indications applied and results achieved are discussed with reference to the literature.

[Monitoring aortocoronary bypass. A new experimental approach]. / Monitoring des aortokoronaren Bypass. Ein neuer experimenteller Ansatz.

Only few data are known concerning haemodynamic parameters and pathomechanisms of small vessels and bypass grafts. No easy-to-use bedside method exists for monitoring. We developed a miniaturised implantable Doppler probe linked to a 20 MHz pulsed Doppler system. In a circulation model and in animal studies we can show the accuracy of this method. We conclude that the implantable pulsed Doppler system is a sensitive method for monitoring the haemodynamics of small vessels.

Experimental and first clinical experiences with implantable ultrasonic Doppler probes for postoperative bypass control after coronary surgery.

Concerning postoperative bypass hemodynamics after open heart surgery only few data are known. With this new implantable doppler probe we developed an easy-to-use bedside method for monitoring postoperative bypass function after coronary artery bypass grafting. The accuracy of our method is shown by using a circulation model and by animal studies. Furthermore first clinical data are shown which support our conclusion of having found a sensitive method for monitoring small vessels' hemodynamics.

[The quality of life of the aged after heart surgery interventions. Analysis of a patient sample of very advanced age]. / Lebensqualität des alten Menschen nach herzchirurgischen Eingriffen. Analyse eines sehr alten Krankengutes.

Due to the continual improvement of surgical and anaesthesiological techniques, the cardiac patients are now of a much higher age than was previously the case. Only pre- and postoperative comparison of life quality can show in what manner these old patients are improved by cardiac surgery. 71 patients with the mean age of 77.6 years were examined by standardized interviews at hospital admittance and one year after returning home. Although there was no statistical significance, there was a very clear trend towards improved quality of life. These very good long-term results concerning the quality of life justify an increased operative risk in this group of 70-80 years old patients. In our study we could show results which were as good as has been shown with younger patients in literature.

Differentiation and functional activity of human eosinophilic cells from an eosinophil HL-60 subline: response to recombinant hematopoietic growth factors.

We studied the effect of hematopoietic growth factors (granulocyte-macrophage colony-stimulating factor [GM-CSF], granulocyte [G]-CSF, interleukin (IL)-1, IL-3, IL-5, IL-6, and macrophage [M]-CSF) on differentiation and functional activity of human eosinophilic HL-60 cells (Eos-HL-60) and compared them with effects on parental HL-60 promyelocytic leukemia cells. Purified biosynthetic GM-CSF and IL-5 enhanced cell proliferation and induced eosinophilic differentiation in the eosinophilic subline in both liquid and agar cultures. IL-3 and IL-6 stimulated cell proliferation but had no effect on cell differentiation, whereas IL-1 and G-CSF affected neither differentiation nor proliferation of Eos-HL-60 cells under the conditions tested. GM-CSF-, IL-3-, and IL-5-treated Eos-HL-60 cells showed increased O2- production in response to phorbol esters (PMA), enhanced phagocytosis of Candida albicans, and release of the enzymes arylsulfatase, beta-glucuronidase and eosinophil peroxidase (EPO). The degranulation of eosinophils induced by GM-CSF, IL-5, and IL-3 may have relevance to the potential clinical toxicity of these hematopoietins, which also stimulate eosinophilopoiesis. G-CSF had no effect on enzyme release, oxidative metabolism, or phagocytic capacity of Eos-HL-60 cells. IL-5 did not affect proliferation, differentiation, or enzyme release in promyelocytic HL-60 cells. These results indicate the specificity of IL-5 for the eosinophil lineage, confirm the effects of GM-CSF and IL-3 on eosinophilopoiesis and mature eosinophil function in a model system, and indicate the absence of G-CSF and IL-1 stimulation of eosinophils. The Eos-HL-60 line is a useful model for studying human eosinophil responses to cytokines.