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Biomedical subjects

J Boldt

Publications and source records attributed to J Boldt.

At least 271 records · Page 15Linked to original sources
PubMed1989

Influence of acute volume loading on right ventricular function after cardiopulmonary bypass.

The influence of acute volume loading on right ventricular function immediately after extracorporeal circulation (ECC) was investigated in 25 patients undergoing elective aortocoronary bypass grafting. In addition to commonly monitored hemodynamic variables, right ventricular (RV) ejection fraction (EF) was measured by thermodilution technique using a new fast-response thermodilution catheter. In eight patients with concomitant severe stenosis (greater than 89%) of the right coronary artery (RCA), volume loading was followed by a decreased RVEF and cardiac output. In contrast, RVEF in the 17 patients without diseased RCA increased significantly, with an increase in cardiac output. Duration of aortic cross-clamping (i.e., ischemia) was more pronounced in the group with decreased RVEF due to RCA grafting. Increased end-diastolic volume and decreased RV contractility index indicated that patients with myocardial ischemia during cardiac surgery procedures sometimes were unable to make the adaptations required. We conclude that cardiocirculatory dysfunction associated with ECC may be caused by depressed RV function. Acute volume loading in this situation may lead to further deterioration of myocardial function due to RV failure, a condition which cannot be diagnosed readily at the bedside with the usual monitoring techniques.

Aged↗
PubMed1989

An immunohistochemical study of architectural remodeling and connective tissue synthesis in pulmonary fibrosis.

Fibroblasts in healthy adult lung are quiescent, synthesizing little collagen. We studied lung biopsies from 30 patients with pulmonary fibrosis, using immunohistochemistry with monoclonal antibodies against the propeptides of type I collagen to localize fibroblasts actively synthesizing collagen. Adjacent sections were stained with antibodies to type III and IV collagen, fibrin, cytokeratin, plasma fibronectin, or EDIIIa-containing "cellular" fibronectin (cFN). In rapid pulmonary fibrosis, including the proliferative phase of diffuse alveolar damage, organizing pneumonia, and subacute idiopathic fibrosis, collagen-synthesizing cells were numerous in organizing exudate filling airspaces but were also seen in the interstitium of the alveolar walls, interlobular septa, and walls of blood vessels. The new matrix deposited in the airspaces also contained type III collagen and EDIIIa-containing fibronectin. In chronic pulmonary fibrosis, more than half of the biopsies showed foci of collagen synthesis and cFN deposition near the air-tissue interface. The foci were consistently localized outside remnants of basal lamina and therefore within airspaces. The results indicate that (1) fibrosis in chronic idiopathic pulmonary fibrosis results mainly from organization of exudate within airspaces, just as it does after acute lung injury, and (2) during this process, fibroblasts increase their synthesis of collagen and fibronectin coordinately. Foci of active matrix deposition provide evidence for the progressive nature of chronic pulmonary fibrosis.

Antibodies, Monoclonal↗
PubMed1989

Hemodynamic effects of enoximone in cardiac surgery patients.

Enoximone belongs to a new class of inotropic drugs that are not related either to digitalis or to catecholamines. It acts primarily through selective inhibition of phosphodiesterase III (PDE-III) and has additional vasodilating properties. Hemodynamic effects of intravenously administered enoximone (0.5 mg/kg) were investigated in patients undergoing aortocoronary bypass grafting before and during anesthesia as well as during extracorporeal circulation (ECC). Patients who were impossible to be weaned off ECC without pharmacological support were investigated also. A significant increase in cardiac index and dp/dtmax, a decrease in pulmonary capillary pressure, and a small decrease in mean arterial pressure were the major hemodynamic effects. Heart rate was not changed and no signs of arrhythmia were seen during the entire investigation period. Interactions with the anesthetics used could not be observed in this study. In patients with impaired myocardial performance during weaning from ECC, enoximone seems to be helpful in stabilizing cardiac output and decreasing filling pressure. The mechanism for improvement appears to be enhanced contractility due to its positive inotropic effects, as well as a decrease in left ventricular outflow resistance resulting from peripheral vasodilation.

Cardiac Surgical Procedures↗
PubMed1989

[Hemodynamic effects of the new phosphodiesterase inhibitor enoximone in heart surgery patients].

The new phosphodiesterase-III inhibitor (PDI) enoximone is a non-catecholamine, non-glycoside cardiotonic agent with concomitant vasodilating properties. It has proved beneficial in patients with severe chronic heart failure. The influence of enoximone i.v. on hemodynamics was investigated during cardiac surgery under various conditions. METHODS. A randomized series of 60 patients undergoing elective aorto-coronary bypass grafting were studied. The hemodynamic effects of 0.5 mg/kg enoximone given i.v. as a bolus (30 s) were investigated before anesthesia (n = 10), during anesthesia (n = 10), and during extracorporeal circulation (ECC, n = 10) and compared with those observed in corresponding control groups (n = 10 in each control) of patients who had received saline solution as placebo. Anesthesia was maintained with weight-dependent dosages of fentanyl, midazolam and pancuronium bromide. All patients were invasively monitored by means of a pulmonary artery catheter. Additionally, left ventricular pressure (LVP), left ventricular end-diastolic pressure (LVEDP) and dp/dtmax were measured before the initiation of ECC. During ECC direct vascular effects were investigated with measurement of perfusion pressure and the volume of the oxygenator. RESULTS. Before the induction of anesthesia no significant change in MAP and HR could be observed, whereas CI increased (+20%) and TSR decreased (-24%) significantly. During anesthesia, the injection of enoximone was followed by a significant decrease in MAP only in the 1st min (-17%); baseline level was reached again after 6 min; and HR was slightly increased (+8%). TSR (-31%) and LVEDP (-38%) decreased, whereas CI (+17%) and dp/dtmax (+45%) were increased significantly. During ECC perfusion pressure (-37%) and the volume of the oxygenator (-17%) were significantly decreased, demonstrating direct vasodilating effects on both the arteries and the vein. CONCLUSION. Arterial and venous vasodilation with an increase in myocardial performance (dp/dtmax) resulting in an increase in CI were the predominant hemodynamic effects of enoximone i.v. No arrhythmogenic effects or interactions with the anesthetics used were observed in this study.

Anesthesia↗
PubMed1989

[Homologous fresh frozen plasma in heart surgery. Myth or necessity].

Routine administration of homologous fresh frozen plasma (FFP) is widely carried out in cardiac surgery although the risks of blood transfusion can never be excluded. The effect of two units of FFP (430 +/- 11 ml) given after the end of extracorporeal circulation (ECC) (group 1, n = 20) was compared to a control group (n = 20) without FFP in elective aorto coronary bypass patients. Various laboratory parameters, including coagulation data, were measured before and after the end of ECC up to the 1st postoperative day. The patients were comparable with regard to biometric data, anesthesia, and surgical procedure. The major result of this study shows, that routine administration of FFP has no beneficial effect with respect to hemostatic balance. In comparison to a control group, the increase in elastase and decrease in paO2 was even more pronounced in the FFP group. Both blood loss and the need for blood transfusion did not differ between the groups. It can be concluded that a bleeding tendency in cardiac surgery may be caused by ECC itself and by perioperative plasma loss. The routine administration of a relatively small amount of FFP has no positive influence on hemostasis. Substitution therapy in this situation should be guided by the results of coagulation studies.

Aged↗
PubMed1989

[Preoperative normvolemic hemodilution in heart surgery. Pulmonary changes with the use of new technics].

Interest in preoperative hemodilution (HD) has intensified perceptibly again, because of the increasing risk of adverse reactions to donor blood. However, in coronary surgery patients the use of HD is still the subject of controversy, as it may possibly influence organ function and especially lung water content. New techniques, including membrane oxygenation, extracorporeal circulation (ECC) with only "partial" bypass due to 2-stage cannulation, and hemoconcentration with cell separators, have significantly modified patient management in the field of cardiac surgery. Therefore, the influence of moderate hemodilution (12 ml/kg) on extravascular lung water (EVLW) was investigated under these conditions in 45 patients with coronary artery disease. Volume replacement was performed either with hydroxyethyl starch solution (HD-HES group, n = 15, ratio of replacement 1:1) or with Ringer's lactate (HD-RL-group, n = 15, ratio 2.5:1); 15 patients not subjected to HD served as controls. ECC was carried out with membrane oxygenators only in partial bypass. Both during and after ECC, blood was concentrated by means of a cell-saving system allowing separation and reinfusion of the red cells while the plasma is discarded. EVLW was measured using a double-indicator dilution technique with indocyanine green. Starting from comparable baseline values, EVLW was not significantly changed by hemodilution. After ECC, however, the HD-RL group showed a significant increase in lung water content (means: +2.49 ml/kg equal 42.6%), whereas this was not significantly changed in the other groups. By 5 h after ECC, the lung water content had returned to baseline values and no more differences could be observed between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Water↗
PubMed1989

[Sympatho-adrenergic reactions following theophylline administration with the use of various anesthesia technics].

The mechanism of action of theophylline is still the subject of controversy. Possible mechanisms that have been suggested are inhibition of phosphodiesterase, release of catecholamines, effects on intracellular calcium, and adenosine antagonism. With regard to these aspects, it was the aim of this study to compare sympatho-adrenal responses after theophylline application during different anesthetic techniques. A total of 60 patients scheduled for orthopedic surgery were investigated: they were divided into three groups of 20 patients who received either halothane anesthesia with thiopentone induction, modified neurolept anesthesia with fentanyl and midazolam, or spinal anesthesia with bupivacaine and mepivacaine. Within these three groups, the patients were randomly allocated to a theophylline collective receiving an injection of theophylline, 4 mg/kg body weight and to the control group. Plasma levels of epinephrine and norepinephrine (by HPLC/ECD), glucose, lactate and free glycerol and MAP and HR were determined over a period of 120 min. In all groups, epinephrine levels increased immediately after injection of theophylline; group levels of epinephrine were higher in the theophylline-groups than in controls (P less than 0.0001). A remarkable increase was observed within 60 min. Peak epinephrine concentrations were comparable after single injections of 100 micrograms or infusions of 5 micrograms/min. The norepinephrine increase after theophylline injection was brief and less pronounced. MAP, HR, glucose, lactate and free glycerol were not influenced by theophylline. A comparison of the theophylline patients showed no statistical differences attributable to the different anesthetic techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Blood conservation in cardiac operations. Cell separation versus hemofiltration.

The effects of hemoconcentration performed during and after extracorporeal circulation by either centrifugation (cell separation group, n = 20) or hemofiltration (n = 20) were investigated in 40 patients undergoing elective aorta-coronary bypass grafting. Interest was focused on the quality of the blood concentrated from the blood remaining in the extracorporeal circuit and on the reaction of the patients after retransfusion of the concentrated products. Hemofiltration was easy to perform and produced whole blood quicker than the cell separation technique. Coagulation studies revealed no significant differences in heparin concentration, levels of fibrinogen and antithrombin III, or platelet counts. Various coagulation parameters tended to normalize completely and more quickly after hemofiltration than after centrifugation. None of the patients had severe bleeding postoperatively. Free hemoglobin levels were not affected by hemofiltration; elastase concentration was higher only immediately after retransfusion of the concentrated blood, with no effect on organ function. We conclude that both methods were effective means of hemoconcentration during extracorporeal circulation and in salvaging the diluted pump blood after extracorporeal circulation. Loss of plasma fraction is an important disadvantage in the centrifugation technique, which can be avoided by hemofiltration; derangement in colloid osmotic pressure and coagulation parameters was less pronounced after hemofiltration. Costs were lower, as well. Therefore, when a high volume of cardioplegic solution and two-stage cannulation are used, hemofiltration seems to be the method of choice for blood conservation during cardiac operations.

Aged↗
PubMed1988

Inhibition of amino acid uptake and incorporation into proteins in Friend erythroleukemia cells by the anthracycline antitumor antibiotic aclacinomycin A.

Treatment of Friend erythroleukemia cells with aclacinomycin A caused a concomitant inhibition of the uptake of 14C-alpha-aminoisobutyric acid (AIB) and of the incorporation of 3H-alanine into proteins. The decrease in amino acid uptake and incorporation into proteins was dose-dependent and reached a maximum of 60% within 3 hours at the concentration of aclacinomycin A, 200 ng/ml. A comparison of the effect on protein incorporation of 3H-alanine and cell proliferation by various anthracycline antitumor antibiotics in a concentration range of 50-200 ng/ml revealed that two other N-alkylated anthracyclines, pyrromycin and marcellomycin, are also potent inhibitors of the incorporation of amino acids into proteins. Inhibition of amino acid incorporation into proteins correlated well with the reduction of cell number at a later time. In contrast, adriamycin and daunomycin inhibited the incorporation of 3H-alanine into proteins only weakly, although these substances were highly active at inhibiting cell proliferation. Studies with an inhibitor of RNA synthesis, actinomycin D, suggest that the concomitant inhibition of amino acid uptake and incorporation into proteins observed with aclacinomycin A is not due to a reduced RNA synthesis. In addition, aclacinomycin A, up to a concentration of 10 micrograms/ml, did not inhibit protein synthesis in a cell-free translational system from rabbit reticulocytes. These results indicate that the reduction of amino acid incorporation into proteins after treatment of Friend erythroleukemia cells with aclacinomycin A may be due to a reduced uptake of amino acids. Inhibition of the transport of 14C-AIB may be indicative for an interaction of aclacinomycin A with the plasma membrane.

Aclarubicin↗
PubMed1988

Influence of acute preoperative hemodilution on right ventricular function.

In a randomized study, the effects of acute, preoperative hemodilution (HD) (12 mL/kg) on right ventricular function were investigated in coronary artery surgery patients with reduced left ventricular function (ejection fraction < 50%) and significant stenosis of the right coronary artery (RCA). Blood was replaced either by hydroxyethyl starch (HES) solution (ratio 1:1; HD-HES; n = 15) or by Ringer's lactate, (RL) (ratio 2.5:1; HD-RL; n = 15). Fifteen comparable patients without HD served as a control group. Besides commonly measured pressure parameters, right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and right ventricular ejection fraction (RVEF) were measured using a computerized thermodilution technique before and after HD, as well as after extracorporeal circulation (ECC). Right ventricular systolic function, expressed as RVEF, was not changed significantly by HD in any group. Furthermore, right ventricular function of the hemodiluted patients was not impaired by the subsequent ECC procedure. None of the traditionally measured parameters could be correlated significantly to the right ventricular thermodilution variables. It is concluded that moderate HD does not change right ventricular function even when the RCA is significantly stenosed.

Aged↗
PubMed1988

Revascularization of the right coronary artery: influence on thermodilution right ventricular ejection fraction.

This study was designed in order to evaluate the influence of right coronary artery (RCA) disease and its revascularization on right heart performance monitored by measuring thermodilution right ventricular ejection fraction (RVEF). Forty patients undergoing elective aortocoronary bypass surgery were divided into two groups: group 1, with RCA revascularization, n=20; and group 2, without RCA disease or revascularization, n=20. RVEF was measured using a pulmonary arterial catheter mounted with a fast-response thermistor and a bedside microprocessor ejection fraction computer. The major finding of the study was that myocardial revascularization with extracorporeal circulation was followed by a decrease in RVEF which was significantly more pronounced in group 1 (-13.1%) in comparison to group 2 (-5.0%). RVEF gradually increased after bypass, but did not reach baseline values. By the first postoperative day, RVEF had reached baseline values again in group 1 and had increased beyond baseline values in group 2. Traditionally measured hemodynamic parameters could not be correlated with the course of RVEF, except for cardiac index. The present study further suggests that right-sided events may have clinical effects on left-sided function. Inadequate protection of the right heart, especially in patients with RCA stenosis, may result in depression of right ventricular myocardial performance, which can be monitored serially by measuring RVEF.

Blood Pressure↗
PubMed1988

Enzymatic alteration of the ability of mouse egg plasma membrane to interact with sperm.

The effect of a variety of proteolytic, glycosidic and lipid hydrolyzing enzymes on the ability of mouse egg plasma membrane to interact with sperm was evaluated in this study. Zona-free mouse eggs were exposed to enzymes at various concentrations, washed, and inseminated; the number of sperm attached to or having penetrated the egg plasma membrane was determined at 20 and 180 min post-insemination, respectively. The proteases trypsin and chymotrypsin caused concentration-dependent reductions in both sperm attachment and sperm penetration levels when eggs were incubated at enzyme concentrations ranging from 1- to 1000 micrograms/ml for 30 min prior to insemination. Time-course studies revealed significant inhibition of both sperm attachment and sperm penetration levels after treating zona-free eggs for 5 min at 1000 micrograms/ml of either trypsin or chymotrypsin. Several of the phospholipases tested, including phospholipases C, D, and A2, had no inhibitory effect on sperm penetration levels, with phospholipase C and A2 (100 micrograms/ml) causing inhibition of sperm attachment. Of the glycosidic enzymes evaluated, glucuronidase (1000 micrograms/ml) caused significant inhibition of sperm binding but not sperm penetration, and glucosidase, galactosidase, and neuraminidase had no effect on either sperm attachment or sperm penetration. These findings indicate that the ability of the mouse egg plasma membrane to fuse with sperm can be preferentially altered by treatment with proteases.

Animals↗
PubMed1988

Influence of acute normovolemic hemodilution on extravascular lung water in cardiac surgery.

Preoperative hemodilution (HD) is an established blood-saving method. With HD, however, a concomitant increase in extracellular and interstitial water has been reported. This randomized study was undertaken to compare the effects of acute normovolemic HD (10 ml/kg; n = 15) using hydroxyethyl starch solution (HES) on extravascular lung water (EVLW) with those of an untreated control group (n = 15) of cardiac surgery patients submitted to extracorporeal circulation (ECC). A thermal-dye technique was used to measure EVLW. There was no significant change in EVLW due to preoperative HD (5.55 +/- 0.51 vs. 5.71 +/- 0.59 ml/kg). After ECC, a transient increase in both groups could be demonstrated because of a possible change in pulmonary capillary permeability (maximal increase in the HD group: +1.30 ml/kg and in the nonHD group: +1.02 ml/kg). Five hours after ECC, no differences could be seen between the groups. Pulmonary gas exchange was not significantly affected (PaO2 in the HD group: -20 torr). Hemodynamic and laboratory variables indicated the typical changes during HD (cardiac index increases while albumin concentration decreases); circulatory stability was maintained during the entire study. We conclude that preoperative normovolemic HD did not increase lung water content significantly nor compromise pulmonary function even in cardiac surgery patients. Although ECC provides an additional HD (crystalloid priming of the heart-lung bypass machine) and possibly damage of capillary integrity, the two groups did not differ.

Body Water↗
PubMed1988

RETRACTED: Influence of PEEP ventilation immediately after cardiopulmonary bypass on right ventricular function.

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.

Cardiac Output↗
PubMed1988

[Hemodynamic effects of benzodiazepines].

Benzodiazepines are of major interest in anesthesiology and intensive care medicine; they are indicated world-wide pre-, intra- and postoperatively. Application of these drugs is influenced by their side-effects such as hemodynamic changes, limiting their indication. The paper is focusing on general hemodynamic changes caused by benzodiazepines; the most important intravenous derivatives are reviewed with specific reference to their hemodynamic profile.

Anti-Anxiety Agents↗
PubMed1988

[Enoximone, a new phosphodiesterase inhibitor: the spectrum of applications during heart surgery--a comparison with dobutamine].

During cardiac surgery treatment of deterioration of myocardial function is usually based on catecholamines. Development of selective phosphodiesterase-(PDE-)III-inhibitors seems to be a new aspect in treating myocardial dysfunction. Therefore the hemodynamic effects of the new PDE-inhibitor enoximone were investigated in 20 coronary surgery patients unable to be weaned from extracorporeal circulation (ECC) without pharmacological intervention (MAP less than 60 mmHg, CI less than 2.00 l/min.m2, PCP greater than 15 mmHg). After controlled reperfusion with 2.4 1/min.m2 two groups were separated in a random sequence receiving either 0.5 mg/kg enoximone as a bolus (n = 10), or dobutamine (n = 10, 5 micrograms/kg.min) as perfusion. In the dobutamine-group MAP and CI (-14%) were decreased, while HR was increased significantly (+30%). Application of enoximone was followed by a slight increase in CI (+5%), a significant decrease in TSR while HR remained almost unchanged. PCP, too, differed significantly between the groups (enoximone: -38%; dobutamine: -10%). Ten minutes after weaning from ECC additional pharmacologic therapy (calcium, vasodilators, epinephrine) was necessary in eight dobutamine treated patients in contrast to four patients in the enoximone group (calcium, epinephrine). In patients with impaired myocardial performance during weaning from ECC enoximone seems to be an alternative therapy and is judged to be of some advantage compared to dobutamine application in this situation. The mechanism for improvement appears to be enhanced contractility owing to its positive inotropic effects, as well as a decrease in left ventricular outflow resistance resulting from peripheral vasodilation.

Aged↗