Retraction notice to "Haemodynamic effects of the phosphodiesterase inhibitor enoximone in comparison with dobutamine in esmolol-treated cardiac surgery patients" [Br J Anaesth 64 (1990) 611-6]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief, Professor Hugh Hemmings, based on the recommendations of Justus-Liebig-University Giessen following an internal review of research conducted by Joachim Boldt at the University. This is further described in 'Further Retractions of Articles by Joachim Boldt', https://doi.org/10.1016/j.bja.2020.02.024.

Reduced plaque formation induced by rosiglitazone in an STZ-diabetes mouse model of atherosclerosis is associated with downregulation of adhesion molecules

Adhesion molecules have been implicated in the development and progression of cardiovascular disease, which is highly prevalent in people with diabetes. Adhesion molecules can mediate adhesion of leukocytes to the endothelium. Furthermore, P-selectin expressed on platelets is able to mediate the adhesion of leukocytes to platelets. In this study, we examine the in-vivo and in-vitro effects of rosiglitazone with particular emphasis on three important adhesion molecules (VCAM-1, ICAM-1 and P-selectin). In the aorta of STZ-diabetic apolipoprotein E-deficient (apoE KO) mice, rosiglitazone significantly reduced both total and arch plaque area. The mechanism for this appeared to be reduced macrophage infiltration into the atherosclerotic plaque which was also associated with reduced mRNA levels for VCAM-1, ICAM-1, MCP-1 and P-selectin in the aorta. In-vitro studies revealed reduced cell adhesion of monocytic cells (THP-1) to fibrinogen and endothelial cells (HUVEC) after incubation with rosiglitazone. Furthermore, the reduction in leukocyte adhesion also correlated with significant reductions in mRNA levels for VCAM-1, ICAM-1 and P-selectin indicating that reduced macrophage infiltration in atherosclerotic plaques may occur as a result of a direct effect of rosiglitazone on adhesion molecules in both monocytes and endothelial cells. Thus, we have shown that rosiglitazone appears to have direct anti-atherosclerotic effects in an animal model of diabetes-associated atherosclerosis which are at least partly due to effects on VCAM-1, ICAM-1, MCP-1 and P-selectin expression which leads to decreased leukocyte adhesion and macrophage infiltration.

Study of the pharmacokinetic interaction between simvastatin and prescription omega-3-acid ethyl esters

The coadministration of prescription omega-3-acid ethyl esters (P-OM3) with a statin may present a treatment option for patients with mixed hyperlipidemia. This open-label, randomized, 2-way crossover, drug-drug interaction study evaluated the impact of P-OM3 capsules on plasma simvastatin pharmacokinetics in 24 healthy volunteers. Under fasted conditions, 80 mg simvastatin was administered with or without 4 g P-OM3 for two 14-day periods. After 14 days of dosing to achieve steady state, no significant differences were found in either the extent (AUC(tau)) or rate (Cmax) of exposure to simvastatin or its major beta-hydroxy metabolite after coadministration of P-OM3 with simvastatin compared with administration of simvastatin alone. At steady state, the coadministration of P-OM3 capsules did not appear to affect the pharmacokinetics of simvastatin tablets. The combination of P-OM3 capsules and simvastatin appeared to be well tolerated.

Raised Plasma Soluble P-Selectin in Peripheral Arterial Occlusive Disease Enhances Leukocyte Adhesion

Raised levels of soluble P-selectin (sP-selectin) have been reported in the plasma of patients with vascular diseases; however, the functional importance of this ligand remains unclear. In this study we have examined a potential role for plasma sP-selectin in regulating neutrophil adhesion in patients with peripheral arterial occlusive disease (PAOD). Patients with PAOD had significantly higher levels of sP-selectin (mean±SD: 73.3±13.0 versus 16.7±6.4 ng/mL) and enhanced whole blood leukocyte adhesion to platelets under shear. To examine whether the raised sP-selectin levels can directly influence leukocyte adhesion, isolated neutrophils were incubated with plasma from PAOD patients before and after immunodepletion of sP-selectin. Neutrophil adhesion to fibrinogen increased 2-fold following incubation with PAOD plasma, which was abrogated on sP-selectin immunodepletion. We subsequently demonstrated that recombinant sP-selectin dose-dependently (75 to 250 ng/mL) increased leukocyte adhesion to fibrinogen and platelet monolayers. This increase was PSGL-1 and Src kinase-dependent and correlated with an increase in sP-selectin-mediated Mac-1 activation. sP-selectin–stimulated neutrophil adhesion to platelet monolayers was inversely correlated with shear, such that at low shear (50 s −1 ) a 92.7%±15.7 increase in adhesion was observed decreasing to 38.5%±11.9 at 150 s −1 and 10.1%±7.4 at 300 s −1 . These studies suggest a potentially important role for sP-selectin in modulating neutrophil adhesion in patients with PAOD, particularly at sites of low shear, where it raises the possibility that raised plasma sP-selectin levels may enhance leukocyte recruitment to vascular injury and promote disease progression.

[S-(+)-ketamine versus ketamine racemic mixture: hemodynamic studies]

OBJECTIVE

Evaluation of hemodynamic effects of S-(+)-ketamine versus ketamine-racemic mixture during induction of anesthesia, during steady-state of a fentanyl-midazolam-anesthesia and in the period of aortic cross-clamping during extracorporeal circulation.

METHODS

PATIENTS

80 patients scheduled for coronary revascularization.

STUDY DESIGN

double-blind, randomized.

STUDY 1

Induction of anesthesia with ketamine-racemic mixture (3 mg/kg) or S-(+)-ketamine (1.5 mg/kg) plus midazolam 0.15 mg/kg.

PARAMETERS

invasive hemodynamic monitoring including right ventricular volumes and pressure. STUDY 2: Bolus of ketamine-racemic mixture (3 mg/kg), S-(+)-ketamine (1.5 mg/kg) or placebo during steady-state anesthesia with fentanyl and midazolam.

PARAMETERS

see study 1, additionally left ventricular systolic and end-diastolic pressure and maximum speed of left ventricular pressure increase (dp/dt). STUDY 3: Bolus of ketamine-racemic mixture (3 mg/kg), S-(+)-ketamine (1.5 mg/kg) or placebo in the period of aortic cross clamping during ECC.

PARAMETERS

mean systemic pressure, central venous pressure, reservoir volume.

RESULTS

STUDY 1

Heart rate and systemic blond pressure remained unchanged until intubation, which caused significant increases of these parameters. Stroke volume Index and cardiac index decreased in the S-(+)-group compared with racemic mixture, right- and left ventricular filling parameters remained unchanged throughout the study. STUDY 2: There were no significant hemodynamic changes with time or between the groups. STUDY 3: Significant arterial vasodilation was observed in the racemic mixture group, venous parameters remained unchanged.

CONCLUSION

There were no major differences in the hemodynamic profiles of S-(+)-ketamine and the racemic mixture. S(+)-ketamine did not provide hemodynamic advantages. The use of both preparations should be limited to selected clinical situations in patients with reduced coronary reserve.

Human napsin A: expression, immunochemical detection, and tissue localization

A novel aspartic proteinase, called napsin, has recently been found in human and mouse. Due to high similarity with cathepsin D a structural model of human napsin A could be built. Based on this model a potential epitope SFYLNRDPEEPDGGE has been identified, which was used to immunize rabbits. The resulting antibody was employed in monitoring the expression of recombinant human napsin A in HEK293 cell line. Western blot analysis confirmed the specificity of the antibody and showed that human napsin A is expressed as a single chain protein with the molecular weight of approximately 38 kDa. Immunohistochemical studies revealed high expression levels of napsin A in human kidney and lung but low expression in spleen.

High-resolution intravascular magnetic resonance imaging: monitoring of plaque formation in heritable hyperlipidemic rabbits

BACKGROUND

The individual makeup of atherosclerotic plaque has been identified as a dominant prognostic factor. With the use of an intravascular magnetic resonance (MR) catheter coil, we evaluated the effectiveness of high-resolution MR in the study of the development of atherosclerotic lesions in heritable hyperlipidemic rabbits.

METHODS AND RESULTS

Sixteen hyperlipidemic rabbits were investigated at the ages of 6, 12, 24, and 36 months. The aorta was studied with digital subtraction angiography and high-resolution MR with the use of a surface coil and an intravascular coil that consisted of a single-loop copper wire integrated in a 5F balloon catheter. Images were correlated with histological sections regarding wall thickness, plaque area, and plaque components. Digital subtraction angiography revealed no abnormalities in the 6- and 12-month-old rabbits and only mild stenoses in the 24- and 36-month-old rabbits. High-resolution imaging with surface coils resulted in an in-plane resolution of 234x468 microm. Delineation of the vessel wall was not possible in younger rabbits and correlated only poorly with microscopic measurements in the 36-month-old rabbits. Intravascular images achieved an in-plane resolution of 117x156 microm. Increasing thickness of the aortic wall and plaque area was observed with increasing age. In the 24- and 36-month-old animals, calcification could be differentiated from fibrous and fatty tissue on the basis of the T2-fast spin echo images, as confirmed by histological correlation.

CONCLUSIONS

Atherosclerotic evolution of hyperlipidemic rabbits can be monitored with high-resolution intravascular MR imaging. Image quality is sufficient to determine wall thickness and plaque area and to differentiate plaque components.

Blood-borne tissue factor: another view of thrombosis

Arterial thrombosis is considered to arise from the interaction of tissue factor (TF) in the vascular wall with platelets and coagulation factors in circulating blood. According to this paradigm, coagulation is initiated after a vessel is damaged and blood is exposed to vessel-wall TF. We have examined thrombus formation on pig arterial media (which contains no stainable TF) and on collagen-coated glass slides (which are devoid of TF) exposed to flowing native human blood. In both systems the thrombi that formed during a 5-min perfusion stained intensely for TF, much of which was not associated with cells. Antibodies against TF caused approximately 70% reduction in the amount of thrombus formed on the pig arterial media and also reduced thrombi on the collagen-coated glass slides. TF deposited on the slides was active, as there was abundant fibrin in the thrombi. Factor VIIai, a potent inhibitor of TF, essentially abolished fibrin production and markedly reduced the mass of the thrombi. Immunoelectron microscopy revealed TF-positive membrane vesicles that we frequently observed in large clusters near the surface of platelets. TF, measured by factor Xa formation, was extracted from whole blood and plasma of healthy subjects. By using immunostaining, TF-containing neutrophils and monocytes were identified in peripheral blood; our data raise the possibility that leukocytes are the main source of blood TF. We suggest that blood-borne TF is inherently thrombogenic and may be involved in thrombus propagation at the site of vascular injury.

Role of aromatic transmembrane residues of the delta-opioid receptor in ligand recognition

In the present study we examine the role of transmembrane aromatic residues of the delta-opioid receptor in ligand recognition. Three-dimensional computer modeling of the receptor allowed to identify an aromatic pocket within the helices bundle which spans transmembrane domains (Tms) III to VII and consists of tyrosine, phenylalanine, and tryptophan residues. Their contribution to opioid binding was assessed by single amino acid replacement: Y129F and Y129A (Tm III), W173A (Tm IV), F218A and F222A (Tm V), W274A (Tm VI), and Y308F (Tm VII). Scatchard analysis shows that mutant receptors, transfected into COS cells, are expressed at levels comparable with that of the wild-type receptor. Binding properties of a set of representative opioids were examined. Mutations at position 129 most dramatically affected the binding of all tested ligands (up to 430-fold decrease of deltorphin II binding at Y129A), with distinct implication of the hydroxyl group and the aromatic ring, depending on the ligand under study. Affinity of most ligands was also reduced at Y308F mutant (up to 10-fold). Tryptophan residues seemed implicated in the recognition of specific ligand classes, with reduced binding for endogenous peptides at W173A mutant (up to 40-fold) and for nonselective alkaloids at W274A mutant (up to 65-fold). Phenylalanine residues in Tm V appeared poorly involved in opioid binding as compared with other aromatic amino acids examined. Generally, the binding of highly selective delta ligands (TIPPpsi, naltrindole, and BW373U86) was weakly modified by these mutations. Noticeably, TIPPpsi binding was enhanced at W274A receptor by 5-fold. Conclusions from our study are: (i) aromatic amino acid residues identified by the model contribute to ligand recognition, with a preponderant role of Y129; (ii) these residues, which are conserved across opioid receptor subtypes, may be part of a general opioid binding domain; (iii) each ligand-receptor interaction is unique, as demonstrated by the specific binding pattern observed for each tested opioid compound.

Mononuclear leukocytes invade rabbit arterial intima during thickening formation via CD18-and VLA-4-dependent mechanisms and stimulate smooth muscle migration

The role of mononuclear leukocytes for the migration of smooth muscle cells (SMCs) during intimal thickening was investigated in the rabbit model of electrically stimulated carotid artery. The approach was to inhibit leukocyte entry into the arterial intima with antibodies against the adhesion molecules very late activation antigen-4 (VLA-4) and CD11/CD18. In electrically stimulated control rabbits treated either with saline or a nonspecific antibody, all types of granulocytes, monocytes, and lymphocytes migrated across an intact endothelium into the acellular subendothelial space, followed by the movement of SMCs from the media into the intima within 36 hours of applying electrical current. Treatment of the rabbits with monoclonal antibody (mAb) HP1/2 directed toward the alpha 4 subunit (CD49d) of VLA-4 inhibited mononuclear leukocyte invasion (consisting of monocytes and lymphocytes) by approximately 70% compared with the IgG-treated control rabbits and completely abolished the minimal influx of basophils and eosinophils after 36 hours. Neutrophil infiltration, however, remained unaffected by anti-VLA-alpha 4 treatment. Under these conditions, SMC migration across the internal elastic lamina was reduced by 50%. The use of mAb HP1/2 together with mAb 60.3 (directed to the beta 2 chain of CD11/CD18) completely abolished the influx of monocytes, lymphocytes, and all types of granulocytes into the arterial intima. This complete blockade of leukocyte infiltration resulted in a 70% reduction of intimal SMC accumulation. Together with our previous findings excluding neutrophils as stimulators of SMC migration, the present results indicate that mononuclear leukocyte promote lesion development by stimulating SMC migration.

A combined ELISA-immunoelectron microscopic approach for topological mapping of membrane protein epitopes: application to the nicotinic acetylcholine receptor

Identification of epitope localization on either side of the lipid membrane by immunoelectron microscopy constitutes an intrinsic powerful method of structure determination for membrane proteins. We have developed a method allowing measurement and observation, under almost identical experimental conditions, of the binding of monoclonal antibodies (MAb) to membrane-bound acetylcholine receptor from Torpedo marmorata electric tissue. This method, based on ELISA and electron microscopy of negatively stained specimens, was developed with MAb of known epitope specificity. With native membrane fragments, we found that MAb bound to extracellular epitopes in a stoichiometric manner, whereas almost no binding was detected for intracellular epitopes. The treatment based on tissue homogenization in the presence of Zn2+ ions and sucrose resulted in the formation of large, stable openings, rendering accessible about 25% of intracellular epitopes. Electron microscopic observations showed a clear distinction between antibody binding to either intracellular or extracellular epitopes, both with native and Zn(2+)-treated membranes. In addition, the binding of one antibody directed against an extracellular epitope was strikingly dependent on the packing density of acetylcholine receptor molecules, thus enabling us to further distinguish between two levels of accessibility for extracellular epitopes. The method presented here is of general application for studies of epitope mapping in membrane proteins.

Recruitment and dynamics of leukocytes in the formation of arterial intimal thickening--a comparative study with normo- and hypercholesterolemic rabbits

Leukocyte involvement in intimal thickening was investigated as a function of time and diet. Fibromuscular or foam cell-rich thickings were induced by electrical stimulation (ES) of carotid arteries in rabbits either on a normal or a high (1%) cholesterol diet. Under both dietary conditions granulocytes (predominantly neutrophils), monocytes and lymphocytes migrated through and accumulated beneath a continuous, yet structurally altered endothelium already after 1 day of ES. This preceded the occurrence of smooth muscle cells (SMCs) in the intima. Under normocholesterolemia, leukocyte attachment to the endothelium decreased with continued ES, which coincided with the re-establishment of a normal endothelial cell pattern. Neutrophils ceased to invade the stimulated intima and disappeared from the lesion after 14 days. The proportion of mononuclear leukocytes was also reduced in the thickened intima, finally amounting to 5.5 +/- 5.9% in the 4-week-old fibromuscular lesion where SMCs prevailed. Hypercholesterolemia did not affect neutrophil involvement in response to ES. However, it provoked lipid deposition first in macrophages, then in SMCs and resulted in elevated amounts of mononuclear leukocytes both within the foam cell-rich thickening and in association with the overlying endothelium. These data indicate adaptive behavior of leukocytic infiltration in the development of fibromuscular thickening, and a shift to a chronic inflammatory response under additional hypercholesterolemia.

Inhibition of leukocyte extravasation with a monoclonal antibody to CD18 during formation of experimental intimal thickening in rabbit carotid arteries

In the rabbit model of electrically induced intimal thickening, the adherence processes of different leukocyte subsets as well as the functional significance of leukocyte invasion in the initial migration of smooth muscle cells (SMCs) into the intima were studied by using monoclonal antibody (MAb) 60.3 (directed to the leukocyte adherence glycoprotein CD18), a known potent inhibitor of leukocyte adhesive functions. In control carotid arteries exposed to two periods of electrical stimulation within 36 hours, leukocytes, including all granulocyte subsets, monocytes, and lymphocytes, invaded the cell-free subendothelium. Concomitantly, SMCs were observed to migrate from the media into the intima. In the MAb 60.3-treated rabbits, however, neutrophil emigration into the stimulated arteries was abolished, whereas mononuclear leukocyte accumulation in the intima was only partially inhibited, indicating a complete CD18-dependent mechanism for neutrophil extravasation and additional receptor-ligand systems for the emigration of mononuclear leukocytes. SMCs moved into the intima despite complete blockage of neutrophils and the reduced accumulation of mononuclear cells within the subendothelium after MAb administration. These results preclude neutrophils as initiators of SMC migration into the intima. The influence of mononuclear cells on the migratory behavior of SMCs in intimal thickening formation, however, needs further elucidation.

Acute preoperative hemodilution in cardiac surgery: volume replacement with a hypertonic saline-hydroxyethyl starch solution

Preoperative hemodilution (HD) is a recommended practice in cardiac surgery that conserves blood and reduces the complications of homologous blood transfusion. In 45 patients undergoing myocardial revascularization, HD was performed preoperatively. Withdrawn volume (10 mL/kg) was replaced either by a new hypertonic saline (HS) solution prepared in hydroxyethyl starch (HES) (2,400 mOsm/L, HS-HES group, n = 15) or by a standard low molecular weight hydroxyethyl starch solution (6% HES 200/0.5, HES group, n = 15) to maintain baseline PCWP (acute normovolemic hemodilution [ANH]). Fifteen comparable patients without HD served as controls. Significantly less HS-HES (210 +/- 20 mL) than HES 6% (890 +/- 90 mL) was necessary to sustain hemodynamics during HD. Stable cardiocirculatory conditions were obtained even after termination of bypass. Fluid balance during cardiopulmonary bypass as well as in the postoperative period was significantly lower in HS-HES-treated patients. With regard to hemodynamics, CI increased most in the HS-HES group (+36%), whereas systemic vascular resistance was lower in these patients. Right ventricular ejection fraction increased only in HS-HES patients (+15%). However, sodium concentration as well as osmolarity increased after volume replacement with HS-HES, without exceeding normal values. None of the patients suffered from organ failure. Pulmonary gas exchange (PaO2) was less compromised in the HS-HES patients. There were no renal function differences between the groups. In conclusion, HS solution prepared in HES is an attractive alternative for blood substitution in cardiac patients undergoing acute hemodilution for blood conservation.

Volume therapy with hypertonic saline hydroxyethyl starch solution in cardiac surgery

The ideal solution for volume therapy remains controversial. In cardiac surgery, haemodynamic efficacy as well as the influence of extracorporeal oxygenation are of major interest when administering volume. The present study examines the effects of a new hypertonic saline hydroxyethyl starch solution in comparison to a 6% hydroxyethyl starch solution on haemodynamics and laboratory variables. Patients scheduled for elective aortocoronary bypass grafting received hypertonic saline hydroxyethyl starch (n = 10) or hydroxyethyl starch (n = 10) after induction of anaesthesia in order to double baseline pulmonary capillary wedge pressure. Ten patients without volume therapy served as a control group. Significantly less hypertonic solution than standard solution was effective in doubling pulmonary capillary wedge pressure. Fluid requirements in the patients who received the hypertonic solution were significantly less during, as well as after, cardiopulmonary bypas in comparison to those in the other groups. Cardiac index increased most in the patients who received the hypertonic solution (+34.8%), as did right ventricular end-diastolic volume. Patients in that group showed the highest decrease in total systemic resistance (-29.8%), whereas arterial pressure and right ventricular ejection fraction remained almost unchanged in all groups. No negative alteration in coagulation or organ function was demonstrated within the investigation period. It can be concluded that hypertonic saline hydroxyethyl starch solution seems to be a valuable alternative to conventional volume therapy in cardiac surgery.

Myocardial temperature during cardiac operations: influence on right ventricular function

Maintenance of right heart integrity is frequently neglected during coronary operations. Right ventricular dysfunction sometimes limits the success of the surgical procedure, however. In addition to the use of cardioplegic solutions, myocardial hypothermia during ischemic cardiac arrest seems to be an important factor for guaranteeing right ventricular performance thereafter. This study was designed to measure myocardial temperature in patients with coronary artery disease who have significant stenosis of the right coronary artery in comparison with those who do not have stenosis of the right coronary artery and to evaluate the influence of myocardial temperature on right ventricular hemodynamics after cardiopulmonary bypass. Right ventricular function was assessed by thermodilution technique, which allows measurement of right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume. Right ventricular temperature differed significantly between the two groups, with the lowest value of 15.1 degrees +/- 1.8 degrees C in the group without stenosis of the right coronary artery and a value of 22.2 degrees +/- 2.1 degrees C in the group with stenosis of the right coronary artery. Left ventricular and septal temperatures were without group differences within the investigation period. Right ventricular hemodynamics were impaired only in the group with stenosis of the right coronary artery with a decrease in right ventricular ejection fraction from 44.2% to 34.1% immediately after termination of bypass and an increase in right ventricular end-diastolic volume index (+38%) and right ventricular end-systolic volume index (+70%). Cardiac index decreased only in this group, too (-22.5%). Analysis of covariance revealed a significant correlation only between changes in right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume and the course of right myocardial temperature. It is concluded that right ventricular hypothermia is more difficult to achieve in patients with a diseased right coronary artery. Constant myocardial hypothermia, however, seems to be important in guaranteeing right ventricular function, which easily can be evaluated by the thermodilution technique.

Acute plasmapheresis during cardiac surgery: volume replacement by crystalloids versus colloids

Acute plasmapheresis (APP) is an additional tool for blood conservation during cardiac surgery. In a randomized study of 60 aortocoronary bypass patients undergoing APP, the influence of replacement of the withdrawn autologous plasma (10 mL/kg) by either colloids (low molecular weight hydroxyethyl starch solution [6% HES 200/0.5]) or crystalloids (Ringer's solution) was investigated. APP was performed by means of a centrifugation technique producing platelet-poor plasma. During and after cardiopulmonary bypass (CPB), either a cell saver (CS) or a hemofiltration (HF) device was also used for blood concentration. Almost three times as much crystalloid as HES solution was necessary for replacement of autologous plasma. Fluid balance during CPB was significantly more positive in the crystalloid patients, particularly when a CS was used. Blood loss was highest in the crystalloid patients in whom a CS was used in addition to APP, and these were the only patients who needed packed red cells. The platelet count, AT-III and fibrinogen plasma concentrations, colloid osmotic pressure, albumin, and total protein were significantly less compromised in the patients with colloid volume replacement. These parameters were closest to control values in patients receiving colloid replacement and HF. It is concluded that colloid is preferred for replacement of autologous plasma withdrawn by APP, and HF is superior to the CS when the combined technique for blood conservation is used.

Enoximone treatment of impaired myocardial function during cardiac surgery: combined effects with epinephrine

Enoximone belongs to a new class of noncatecholamine-positive inotropes, which selectively inhibit phosphodiesterase type III and increase cyclic AMP (cAMP). This study was performed in 30 coronary artery surgery patients with impaired myocardial function (ejection fraction [EF] less than 50%). The study's two purposes were to investigate the hemodynamic effects of enoximone, 0.5 mg/kg, administered following induction of anesthesia (phase I), and to assess whether enoximone can potentiate the actions of sympathomimetic agents during weaning from cardiopulmonary bypass (CPB) (phase II). Starting with already reduced hemodynamics, induction of anesthesia led to a further deterioration of blood pressure and cardiac output (CO). Administration of enoximone produced a significant increase in cardiac index (CI) (+47%), whereas pulmonary capillary wedge pressure (PCWP) (-37%), pulmonary artery pressure (PAP) (-17%), and systemic vascular resistance (SVR) (-17%) were significantly reduced. Heart rate (HR) was not increased, and no dysrhythmias occurred during the investigation. The hemodynamic effects were maintained for 30 minutes until the start of the operation. In phase II, where weaning from CPB was not possible without pharmacological support, either enoximone (0.5 mg/kg) + epinephrine (0.1 micrograms/kg/min) or only epinephrine (same dosage) was randomly selected. Weaning was successful in both groups, but the combined therapy produced a larger increase in cl and a more pronounced decrease of the elevated filling pressure (PCWP). PAP was not changed in the combined therapy group, but increased in the patients receiving epinephrine alone. It is concluded that enoximone has beneficial hemodynamic effects in the perioperative period, and that potentiation of the effects of epinephrine in severe heart failure may be one of the drug's most useful features.

RETRACTED: Efficacy of the phosphodiesterase inhibitor enoximone in complicated cardiac surgery

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the request of the editor. In 2018, CHEST published a notice1 that all articles authored by Joachim Boldt be read with caution due to expressions of concern about falsified data. In 2020, CHEST received additional evidence of research misconduct and breaches of scientific integrity that were discovered following an investigation by the author's former institution, the University of Giessen2. In light of this new evidence, this article has been retracted by CHEST. 1. Irwin, R.S., MD, Master FCCP. Notice From the Editor in Chief. CHEST 153(3), p. 767. 2. Mukherjee, J. Statement on the scientific credibility of articles published by Joachim Boldt, formerly professor at Justus Liebig University (JLU), Giessen, Germany. https://ars.els-cdn.com/content/image/1-s2.0-S000709122030163X-mmc3.pdf.

RETRACTED: Acute preoperative plasmapheresis and established blood conservation techniques

Plasmapheresis performed weeks before an operation producing autologous plasma has proved to be of benefit in elective operations. First experiences in acute plasmapheresis, which is performed immediately before the operation, have been reported recently. When acute plasmapheresis is used in cardiac operations, however, it must be viewed in connection with other techniques for reducing blood consumption such as the Cell Saver (CS) and ultrafiltration devices. In 60 patients undergoing elective aortocoronary bypass grafting, acute plasmapheresis was performed, producing either platelet-poor plasma or platelet-rich plasma, in combination with either the Cell Saver or hemofiltration. Fluid balance during cardiopulmonary bypass was significantly lower in the hemofiltration patients. Postoperatively, none of these patients received donor blood, whereas 4 patients of the Cell-Saver groups needed packed red blood cells. AT-III, fibrinogen, the number of platelets, albumin, total protein, and colloid osmotic pressure were less compromised when hemofiltration was used in combination with acute plasmapheresis in contrast to combination with the Cell-Saver technique. Plasma hemoglobin was without differences during the investigation period, and polymorphonuclear elastase was less increased when platelet-rich plasma was produced preoperatively. On the first postoperative day, most of the differences between the groups had already disappeared. We conclude that when acute plasmapheresis is used in cardiac operations, discarding of plasma by the Cell Saver should be avoided and ultrafiltration devices should replace centrifugation techniques for blood conservation.

[The hemodynamic effects of a treatment with beta-receptor blockers during coronary surgery. A comparison between acebutolol and esmolol]

Patients undergoing coronary artery bypass grafting are at risk for perioperative myocardial ischemia. Most such ischemic episodes occur without obvious hemodynamic changes. Tachycardia as a predictor for increased myocardial oxygen consumption doubles the incidence of myocardial ischemia when heart rate increases to over 110 beats/min. During the operative procedure for coronary revascularization, some maneuvers, e.g. intubation, sternotomy and mediastinal preparation, may be associated with tachycardia and increases in blood pressure despite an adequate level of anesthesia, so that the administration of beta-receptor blocking agents seems to be indicated.

METHODS

The study included 20 patients undergoing elective aortocoronary bypass grafting. All patients developed tachycardia (heart rate greater than 100 beats/min) before the start of extracorporeal circulation. The hemodynamic effects of 0.1 mg/kg acebutolol given i.v. as a bolus over 30 s and hemodynamic effects of the ultrashort-acting esmolol by continuous infusion (loading dose 500 micrograms/kg over 1 min followed by a dose of 100 micrograms/kg per min) were randomly investigated. Anesthesia was maintained with fentanyl, midazolam and pancuronium bromide. All patients were invasively monitored by means of a pulmonary artery catheter. In addition, left ventricular pressure (LVP), left ventricular end diastolic pressure (LVEDP) and dp/dtmax were measured.

RESULTS

Both acebutolol and esmolol, decreased the heart rate significantly (-24%, -27.5%), while the mean arterial pressure remained nearly unchanged. The cardiac index was diminished following acebutolol (-15.4%) and esmolol (-27.4%), while no significant change in stroke volume index was observed; systemic vascular resistance rose in all patients. Pulmonary artery pressure, PCP, PRA, LVP and LVEDP were unchanged, whereas dp/dtmax decreased both with acebutolol (-23.5%) and with esmolol (-36.5%).

CONCLUSION

Both beta-receptor blockers--acebutolol and the ultrashort-acting esmolol--diminish heart rate sufficiently when tachycardia occurs during coronary artery bypass grafting. Reduction of heart rate is associated with a decrease of cardiac output and an impairment of myocardial contractility. From the hemodynamic point of view there is no major difference between the two beta-receptor blockers investigated, but esmolol may have an advantage over acebutolol because of its short elimination half-life.

Comparative effects of enoximone and theophylline on plasma catecholamines and haemodynamics in cardiosurgical patients

The release of endogenous catecholamines in aorto-coronary bypass graft patients receiving either 0.5 mg/kg enoximone (n = 10), 4.0 mg/kg theophylline (n = 10) or saline solution (control, n = 10) has been studied, as well as certain haemodynamic parameters. Adrenaline (A) and noradrenaline (NA) concentrations were not significantly changed by the administration of enoximone. Theophylline caused a small increase in NA (+40% in the 1st min) and a marked increase in A (approximately +7000% in the 1st min), which still remained elevated at the end of the investigation period (+220% in the 30th min). The major haemodynamic effects of enoximone were a significant increase in cardiac index (CI; +35%) and a decrease in pulmonary capillary wedge pressure (PCWP; -27%), pulmonary artery pressure (PAP; -21%), RVEDV and RVESV, while the heart rate (HR) remained almost unchanged. The dominant haemodynamic effects of theophylline were an increase in HR (+26%; arrhythmia in 3 patients), PAP (+22%), and RVEDV (+19%), while RVESV (+26%), MAP (-16%), CI (-14%), and RVEF (-15%) fell significantly. It is concluded that the haemodynamic actions of enoximone are not mediated by catecholamine release, whereas the adverse cardiovascular effects of theophylline might partly be explained by the significant increase in plasma adrenaline.

Haemodynamic effects of the phosphodiesterase inhibitor enoximone in comparison with dobutamine in esmolol-treated cardiac surgery patients

In a randomized study, the haemodynamic effects of the new phosphodiesterase-III-inhibitor, enoximone, were compared with dobutamine in acutely beta-adrenoceptor blocked patients. Twenty patients scheduled for aorto-coronary bypass grafting suffering from tachycardia (heart rate (HR) greater than 100 beat min-1) were treated by infusion of esmolol, an ultra-short acting, selective beta 1-blocker. Twenty minutes after the start of esmolol, either enoximone 0.5 mg kg-1 as a bolus (n = 10) or dobutamine 5 micrograms kg-1 min-1 was administered. Haemodynamic effects were monitored for 40 min, including measurement of left ventricular haemodynamics. Esmolol reduced HR (-27%) and dP/dtmax (-38%) significantly in both groups. Cardiac index (CI) was decreased also. Enoximone increased Cl (+35%) and dP/dtmax (+39%) significantly, while no change in dobutamine-treated patients was observed. Systemic vascular resistance increased only in the dobutamine group (+44%).

Effects of nitrous oxide on endocrine stress response and haemodynamic parameters during coronary artery surgery

To compare simultaneously the influence of nitrous oxide on haemodynamic parameters and on surgical stress response, 20 patients scheduled for coronary artery bypass graft were investigated during standardized modified neurolept anaesthesia. Before onset of cardiopulmonary bypass, one group received nitrous oxide and oxygen (2:1), whereas in the other group air with oxygen (F10(2) 0.33) was used. Increases in adrenaline, noradrenaline, ADH, and cortisol were slightly less and mean arterial pressure and cardiac output reached markedly lower levels in the nitrous oxide group. When nitrous oxide is not acceptable for a cardiac surgery patient during modified neurolept anaesthesia due to haemodynamic side effects enhancing intravenous application of anaesthetics to compensate the analgetic properties of the substance should be considered.

Suppression of tumor-forming ability and related traits in MCF-7 human breast cancer cells by fusion with immortal mammary epithelial cells

Somatic cell hybrids between MCF-7 human breast cancer cells and normal immortalized human mammary epithelial cells have been obtained by polyethylene glycol-mediated cell fusion. The hybrid cells are suppressed in their ability to form tumors in nude mice, as well as in traits specific to the tumorigenic MCF-7 parent: growth factor independence, tumor necrosis factor sensitivity, and pS2 gene expression. In addition, they display other characteristics of the "normal" parent, including increased expression relative to the MCF-7 cells of the genes for the extracellular matrix component fibronectin, the intermediate filament keratin 5, and the angiogenesis inhibitor thrombospondin. The levels of keratins 8 and 18 also resemble those of the nontumorigenic parent. These results provide evidence for the existence of tumor suppressor gene products in immortal mammary epithelial cells. We propose a characteristic "suppressed" tumor cell phenotype, which encompasses altered cytoarchitecture, angiogenesis capabilities, and growth factor requirements.

The new phosphodiesterase inhibitor enoximone in patients following cardiac surgery--pharmacokinetics and influence on parameters of coagulation

Enoximone is a selective inhibitor of the phosphodiesterase-III enzyme (PDE-III) and possesses positive inotropic and vasodilatory properties. The PDE-inhibitor amrinone has been associated with adverse effects on coagulation by decreasing platelets. To investigate the influence of enoximone on hemostasis, 18 patients undergoing elective aorto-coronary bypass grafting and receiving enoximone were compared to a control group (n = 18). In addition, the plasma levels of enoximone and its major metabolite (enoximone-sulfoxide) were studied following a single injection (0.5 mg/kg) and during a continuous infusion (5 and 10 micrograms/kg.min) before, during and after extracorporeal circulation (ECC). No difference between study and control groups was found for the parameters of coagulation during the investigation period; in particular there were no differences in platelet count and platelet function (thrombelastography). Following the single bolus, peak plasma levels decreased during ECC to ineffective levels. Continuous infusion, however, maintained effective plasma levels of enoximone; sulfoxide levels were twice as high as enoximone concentrations up until the end of the investigation period. It is concluded that enoximone can be judged to be safe in respect to its effects on coagulation even following ECC and at relatively high doses. The use of continuous infusion results in plasma levels which remain at an effective concentration through to the time that the patient is transferred to the intensive care unit.

Drug interactions: the new phosphodiesterase inhibitor enoximone and the calcium channel blocker nifedipine in coronary surgery patients--influence on hemodynamics and plasma concentrations

The calcium channel blocker nifedipine and the new phosphodiesterase (PDE) inhibitor enoximone are used in the treatment of cardiovascular diseases. Since both substances are acting on slow calcium channels and because systemic elimination of these two agents is dependent on oxidative drug metabolizing enzyme activity, this study was performed in order to investigate hemodynamic changes and effects on plasma levels when both substances are given simultaneously. Forty-five patients undergoing aortocoronary bypass grafting were randomly subdivided into three groups: (a) group (n = 15) received 0.3 micrograms/kg/min of nifedipine as an infusion (N patients); (b) group (n = 15) received 0.5 mg/kg of enoximone as a bolus (E patients); and (c) group (n = 15) received nifedipine and enoximone in the same dosages (E + N patients). In addition to various hemodynamic variables, plasma levels of nifedipine, enoximone, and enoximone sulfoxide were measured until the end of the operation. Injection of enoximone was followed by an increase in cardiac index and right ventricular ejection fraction, decrease in pulmonary artery pressure, pulmonary capillary pressure, and systemic vascular resistance, whereas heart rate and mean arterial pressure remained almost unchanged. These changes were comparable for E and E + N patients. Plasma concentrations of enoximone and enoximone sulfoxide were not affected by nifedipine infusion and showed a comparable course in E and E + N patients. Nifedipine plasma level dropped to values less than 15 ng/ml at the end of extracorporeal circulation in N and E + N patients. It can be concluded that enoximone improved hemodynamics even in patients pretreated with nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

[The hemodynamic effects of various hydroxyethyl starch solutions in heart surgery patients]

Blood conservation is gaining more and more interest because of the increasing risks involved in homologous blood transfusions. Acute normovolemic hemodilution (ANH) is becoming an established technique even in cardiac surgery patients. The "optimal" kind of volume replacement, however, is still controversial. Thus, this study was carried out to investigate the hemodynamic response of 6 different hydroxyethyl starch (HES) solutions as volume replacement. METHODS. In 60 patients undergoing elective aortocoronary bypass surgery, acute, preoperative hemodilution was performed (10 ml/kg) and HES with different concentrations, molecular weight, and substitution was infused according to a randomized sequence: 1. 6% HES 450,000/0.7; 2. 10% HES 200,000/0.5; 3. 3% HES 200,000/0.5%; 4. 6% HES 40,000/0.5; 5. 6% HES 200,000/0.5; 6. 6% HES 200,000/0.62. All patients were monitored using a new pulmonary artery catheter that allows measurement of the right ventricular ejection fraction (RVEF), right ventricular enddiastolic volume (RVEDV), and right ventricular end systolic volume (RVESV) in addition to standard hemodynamic parameters. RESULTS. Immediately after finishing ANH the typical hemodynamic changes of hemodilution (HD) were apparent (decrease in peripheral resistance and increase in cardiac index (CI]. All 6 solutions investigated were effective in hemodynamic stabilization (no changes in mean arterial pressure (MAP), filling pressures (PCP, RAP), or heart rate (HR]. Forty min after ANH, however (before beginning extracorporeal circulation (ECC], there were significant differences between the groups: in groups 3 and 4 the increase in CI had already disappeared, and SVI in group 3 was even lower than the baseline values (-8%). In the other groups, a higher CI level remained even 40 min after ANH, which was most pronounced in groups 2 (+40%) and 5 (+43%). Right ventricular performance was not changed by ANH (RVEF unchanged in all groups). Forty min after hemodilution RVEDVI (-8%) and RVESVI (-16%) decreased significantly only in group 4, whereas in the other groups these parameters were still elevated. The most pronounced positive fluid balance after the end of ECC was found in group 4 (+850 ml); in these patients paO2 decreased significantly (-150 mmHg). CONCLUSIONS. The guarantee of stable hemodynamic conditions is a prerequisite when performing ANH in coronary surgery patients. The different physiochemical attributes of various HES solutions seem to be important, thus influencing their hemodynamic response. In this study, low-concentration (3% HES 200/0.5) and low-molecular (6% HES 40/0.5) HES solutions were less effective in stabilizing hemodynamics until the beginning of ECC. Additionally, their negative influence on fluid balance during ECC, followed by a deterioration in pulmonary function led to the conclusion that other solutions are preferable; in particular, 10% HES seems to be of advantage in these situations.