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Biomedical subjects

A C Moulijn

Publications and source records attributed to A C Moulijn.

At least 19 recordsLinked to original sources
PubMed2001

Screening for solid organ malignancies prior to heart transplantation.

BACKGROUND: Prognosis of solid organ cancer in immunosuppressed hosts is generally dismal. Therefore, every effort to identify patients with asymptomatic carcinomas before transplantation should be encouraged. METHODS: Sixty-seven patients referred for heart transplantation were examined adhering to the scheme proposed at the 24th Bethesda Conference. To increase the sensitivity of this work-up, the following items were added: tumor marker assays (prostate-specific antigen in males, carcino embryogenic antigen), abdominal ultrasound, CT scan of the abdomen and the thorax, mammography/echography of the breasts, PAP smear, colonoscopy if carcino embryogenic antigen abnormal or occult blood in stool, prostate echography if prostate-specific antigen abnormal or prostate hypertrophy. RESULTS: Carcinoma was detected in 10 of the 67 patients; for 8 patients of this cancer group, transplantation was denied. Importantly, 9 of the 10 malignancies were detected by means of the diagnostic items that were added to the standard screening protocol. There were no significant differences between the cancer and the non-cancer group regarding mean age, sex, etiology of heart failure, and smoking history. Stratifying patients in younger (i.e., < or =54 years) and older (i.e., > or =55 years) age groups showed a significantly greater proportion of older patients in the cancer group (8/10=80%) compared to the non-cancer group (25/57=44%), P=0.04. After a mean follow-up of 34 months, 5 of the 36 transplanted patients developed a malignancy (4 skin carcinomas, 1 non-Hodgkin lymphoma). There have been no malignancy-related deaths until now. CONCLUSION: The importance of a thorough screening program in the triage of candidates with preexisting malignancies, especially in an older patient population, is illustrated in this report.

Adult↗
PubMed2001

Establishment of serum-free pre-colony forming unit assays for differentiation of primitive hematopoietic progenitors: serum induces early macrophage differentiation and inhibits early erythroid differentiation of CD34++CD38- cells.

In this report we show that serum has differentiation-inducing effects on primitive hematopoietic progenitor cells with the CD34++CD38- immunophenotype. Using the pre-colony forming unit (pre-CFU) assay as a model for early myelopoiesis, we compared the effects of serum-containing and serum-free media and evaluated different cytokine cocktails [interleukin (IL)-1, IL-3, IL-6, kit ligand with and without the Flt3/Flk2 ligand (FL)]. In this assay, pre-CFUs are defined as cells unable to form colonies when plated directly in semi-solid assays, but which can differentiate into CFUs when cultured in liquid medium containing early-acting cytokines. In one of the investigated serum-free media, the average myeloid expansion in liquid medium reached up to more than 50% of that obtained in serum-containing medium. In addition, our experiments revealed differences in the clonogenic output between cells cultured in serum-free medium and those cultured in serum-containing medium, demonstrating that serum has a monocyte differentiation-inducing effect on primitive hematopoietic progenitors. Also in serum-free medium, higher proportions of erythroid progenitors were generated. These differentiation-inducing effects of serum further emphasize the need for serum-free culture protocols for hematopoietic graft engineering. Addition of FL to the culture media ameliorated cellular expansion and resulted in a decrease in the proportion of erythroid and granulocyte progenitors and an increase in the proportion of monocyte progenitors. In conclusion, this study shows that good serum-free conditions are available for differentiation assays with primitive hematopoietic progenitors and demonstrates that serum and FL have biasing effects on the initial phase of hematopoietic differentiation, favoring the monocyte lineage.

ADP-ribosyl Cyclase↗
PubMed2001

Should we use video-assisted endoscopic vein harvesting as a standard technique?

BACKGROUND: To investigate the feasability and results of endoscopic vein harvesting (EVH) using the Vasoview Uniport system (Guidant Corporation, Menlo Park,CA). Can this technique be used as a standard technique for vein harvesting in coronary artery bypass surgery (CABG) or is it too time consuming? Do smaller incisions result in less morbidity and discomfort? METHODS: From October 1998 to May 1999, 158 patients who underwent CABG with venous grafts, in addition to arterial grafts, formed the study population for EVH. In group A (n=131) the vein was harvested with the Vasoview Uniport System. In group B (n=27) the vein was harvested by a conventional open technique with interrupted incisions because of unavailability of the equipment. Recordings were made on vein length, harvest time, length of incision, and complications. RESULTS: In none of the patients in group A was a conversion to the open technique necessary. In 72/131, pure EVH was used. In 59/131 an additional incision below the knee was used for harvesting extra vein length. Mean harvested vein graft length (cm) was 35.9 (range 18-56) in group A and 30.6 (range 16-51) in group B, and mm of vein harvested/min was 77 and 71 in group A and B. Mean time for harvesting and closing (min) was 56.1 (range 14-120) SD 20.4 and 78.3 (range 37-129) SD 26 for a mean length of incision (cm) of six (range 2-19) and 27 (range 12-54). Wound complications at postoperative day three at discharge, and after six weeks were seen in 30 (23%), 27 (20%) and four (4%) patients of group A, and in five (18%), five (18%) and four (23%) of group B. CONCLUSIONS: Despite a learning curve in using endoscopic techniques, the total procedural time for EHV is acceptable and even shorter than open harvesting. Most of the time is gained in closure of the wound. Hematoma formation is the most common peroperative complication, but diminishes with experience. The absence of postoperative edema after EVH is striking. Despite the higher costs for disposable material, we have adopted EVH as a standard technique since patient and surgeon satisfaction have improved substantially.

Adult↗
PubMed1999

The effects of beta-adrenergic stimulation on the length-dependent regulation of myocardial function in coronary surgery patients.

UNLABELLED: Increasing cardiac load by leg elevation identifies patients with load-dependent impairment of left ventricular (LV) function. This impairment is related to a deficient length-dependent regulation of LV function. We investigated the effects of dobutamine on length-dependent regulation of LV function in coronary surgery patients (n = 25). High-fidelity LV pressure tracings were obtained at end-expiration, while hearts were paced at a fixed rate of 90 bpm. Effects of leg elevation on contraction and relaxation were compared before and during dobutamine 5 microg x kg(-1) x min(-1). Effects on contraction were evaluated by analysis of changes in dP/dtmax. Effects on relaxation were assessed by analysis of R (slope of the relation between the time constant of isovolumic relaxation and end-systolic pressure). Correlations were calculated with linear regression analysis using Pearson's coefficient r. The effects of leg elevation on variables of contraction and relaxation were coupled. We found a close relationship between changes in dP/dtmax and individual values of R (r = 0.84; P < 0.001). Dobutamine improved myocardial function and accelerated LV pressure decrease. Under dobutamine, the increase in dP/dtmax with leg elevation was larger (P < 0.001) and load dependence of LV relaxation was reduced (P = 0.001). Dobutamine improved the effects of leg elevation on LV function, reflecting improved length-dependent regulation of LV function. IMPLICATIONS: This study demonstrated that beta-adrenoreceptor stimulation with dobutamine improved length-dependent regulation of myocardial function assessed during leg elevation in cardiac surgical patients.

Adrenergic beta-Agonists↗
PubMed1999

Contraction-relaxation coupling and impaired left ventricular performance in coronary surgery patients.

BACKGROUND: Dependence of left ventricular (LV) relaxation on cardiac systolic load is a function of myocardial contractility. The authors hypothesized that, if a tight coupling would exist between LV contraction and relaxation, the changes in relaxation rate with an increase in cardiac systolic load would be related to the changes in LV contraction. METHODS: Coronary surgery patients (n = 120) with preoperative ejection fraction >40% were included. High-fidelity LV pressure tracings (n = 120) and transgastric transesophageal echocardiographic data (n = 40) were obtained. Hearts were paced at a fixed rate of 90 beats/min. Effects on contraction were evaluated by analysis of changes in dP/dt(max) and stroke area. Effects on relaxation were assessed by analysis of R (slope of the relation between tau and end-systolic pressure). Correlations were calculated with linear regression analysis using Pearson's coefficient r. RESULTS: Baseline LV end-diastolic pressure was 10+/-3 mm Hg (mean +/- SD). During leg raising, systolic LV pressure increased from 93+/-9 to 107+/-11 mm Hg. The change in dP/dt(max) was variable and ranged from -181 to +254 mm Hg/s. A similar variability was observed with the changes in stroke area, which ranged from -2.0 to +5.5 cm2. Changes in dP/dt(max) and in stroke area were closely related to individual R values (r = 0.87, P<0.001; and r = 0.81, P<0.001, respectively) and to corresponding changes in LV end-diastolic pressure (r = 0.81, P< 0.001; and r = 0.74, P<0.001, respectively). CONCLUSIONS: A tight coupling was observed between contraction and relaxation. Leg raising identified patients who developed a load-dependent impairment of LV performance and increased load dependence of LV relaxation.

Aged↗
PubMed1999

Length-dependent regulation of left ventricular function in coronary surgery patients.

BACKGROUND: Load-dependent impairment of left ventricular (LV) function was observed after leg elevation in a subgroup of coronary surgery patients. The present study investigated underlying mechanisms by comparing hemodynamic effects of an increase in LV systolic pressures with leg elevation to effects of a similar increase in systolic pressures with phenylephrine. METHODS: The study was performed in patients undergoing elective coronary surgery prior to cardiopulmonary bypass. High-fidelity LV pressure tracings (n = 25) and conductance LV volume data (n = 10) were obtained consecutively during leg elevation and after phenylephrine administration (5 microg/kg). RESULTS: Leg elevation resulted in a homogeneous increase in end-diastolic volume. The change in stroke volume (SV), stroke work (SW) and dP/dtmax was variable, with an increase in some patients but no change or a decrease in other patients. For a matched increase in systolic pressures, phenylephrine increased SW and dP/dtmax in all patients with no change in SV. Load dependence of relaxation (slope R of the tau-end-systolic pressure relation) was inversely related for changes in SV, SW, and dP/dtmax with leg elevation but not with phenylephrine. CONCLUSIONS: The different effects of leg elevation and phenylephrine suggest that the observed decrease in SV, SW, and dP/dtmax with leg elevation in some patients could not be attributed to an impaired contractile response to increased systolic LV pressures. Instead, load-dependent impairment of LV function after leg elevation appeared related to a deficient length-dependent regulation of myocardial function.

Aged↗
PubMed1999

Spontaneous dissection of three major coronary arteries subsequent to cystic medial necrosis.

This case report describes the devastating consequences of spontaneous coronary dissection in a 36-year-old female patient. Surgical revascularization was attempted, but diffuse myocardial infarction developed. The patient was bridged to heart transplantation but died secondary to multiple organ failure. To our knowledge, this is the only reported case of spontaneous dissection of the three main coronary arteries due to severe cystic medial necrosis.

Adult↗
PubMed1998

[Quality assessment indicators of cardiac surgeons' work; the validity of mortality rates].

OBJECTIVE: To determine the possibility of comparing the mortality rates of patients operated by different heart surgeons with each other. DESIGN: Retrospective cohort study. SETTING: Academic Medical Centre, Amsterdam, the Netherlands. PATIENTS AND METHODS: Clinical information, operation data and follow-up data on 783 patients who had undergone cardiac valve replacement, were collected from the clinical records. Aortic valve replacement had been performed in 446 patients (1979-1986) and mitral valve replacement in 337 patients (1980-1990). RESULTS: The one-year mortality rate was higher among patients operated on by heart surgeon A than among patients operated on by the other heart surgeons from the same team, viz. 16.4% and 9.5%, respectively, an absolute difference of 6.9%. The 95% confidence interval of the difference was 1.7-12.9. However, it was also found that the risk profiles of these patients of surgeon A differed from those of the other patients. After multivariate correction for this difference in risk profile, the difference in mortality was no longer statistically significant. CONCLUSION: The differences in mortality observed in our study could not be attributed to difference in quality of the heart surgeons, but were related with the risk profiles of the patients operated by one of them. Thorough analysis with correction for risks is necessary for the assessment of the quality of care, if the conclusions are not to be misleading.

Adult↗
PubMed1997

Effects of calcium on left ventricular function early after cardiopulmonary bypass.

OBJECTIVES: Evaluation of the effects of intravenous CaCl2 on systolic and diastolic function early after separation from cardiopulmonary bypass (CPB) DESIGN: Prospective study SETTING: University hospital PARTICIPANTS: Twenty patients scheduled for elective coronary artery surgery INTERVENTIONS: Left ventricular (LV) pressures were measured with fluid-filled catheters. Data were digitally recorded during pressure elevation induced by tilt-up of the legs. Transgastric short-axis echocardiographic views of the LV were simultaneously recorded on videotape. Measurements were obtained before the start of CPB, 10 minutes after termination of CPB, after intravenous administration of CaCl2, 5 mg/kg, and 10 minutes later. MEASUREMENTS AND MAIN RESULTS: Systolic function was evaluated with the slope (Ees, mmHg/mL) of the systolic pressure-volume relation. Diastolic function was evaluated with the chamber stiffness constant (Kc, mmHg/mL) of the diastolic pressure-volume relation. CaCl2 increased Ees from 2.62 +/- 0.46 to 5.58 +/- 0.61 (mean +/- SD), but induced diastolic dysfunction with an increase in Kc from 0.011 +/- 0.006 to 0.019 +/- 0.007. These changes were transient and had disappeared within 10 minutes after administration of CaCl2. CONCLUSIONS: CaCl2 early after CPB transiently improved systolic function at the expense of an increase in ventricular stiffness, suggesting temporary diastolic dysfunction.

Adult↗
PubMed1997

Inotropic effects of sodium nitroprusside: a clinical study on coronary surgery patients.

OBJECTIVE: Sodium nitroprusside (SNP) induces release of nitric oxide and is widely used as a vasoactive drug. Recent research analyzed effects of SNP on cardiac muscle and described variable inotropic effects. The present study evaluated effects of SNP on left ventricular (LV) function in patients undergoing coronary artery surgery. METHODS: The study was performed in 100 patients with a preoperative ejection fraction > 40%. LV pressures were measured with a fluid-filled catheter in the LV cavity. Hearts were placed in AV sequential mode at a rate of 90 beats/min. Measurements were obtained at end-expiration and consisted of a control tracing and a tracing obtained after a 5 min infusion of SNP 0.5 microgram.kg-1.min-1. These measurements were obtained before and after cardiopulmonary bypass (CPB). An average of 5 consecutive beats was obtained for analysis. Ventricular function was assessed with LV pressure and dP/dt. Data were analyzed using two factor analysis of variance for repeated measurements. RESULTS: 1. Baseline patient data (n = 80). Before CPB, a variable inotropic response to SNP was observed. The direction of the inotropic response was related to preoperative beta-blocking medication. LVP and dP/dtmax increased with SNP in patients without preoperative beta-blocking medication. In patients on preoperative beta-blocking medication, SNP did not alter LVP and dP/dtmax. After CPB, a positive inotropic response was not observed in any of the patients. 2. Postoperative patient data under dobutamine (n = 20). Data of these separate observations were similar to baseline data before CPB. After CPB and under dobutamine administration (5 micrograms.kg-1.min-1) all 20 patients developed a positive inotropic response to SNP. CONCLUSIONS: In coronary surgery patients, SNP induced variable inotropic effect. The direction of the inotropic response appeared to be modulated by the beta-adrenergic drive.

Adrenergic beta-Agonists↗
PubMed1996

Biventricular assist for severe acute rheumatic pancarditis.

Severe heart failure in acute rheumatic myocarditis is rare. It may be rapidly reversible with treatment, so maximal medical treatment and, if necessary, mechanical support should be given before heart transplantation is considered.

Acute Disease↗
PubMed1996

Nonfebrile mitral valve endocarditis due to Neisseria subflava.

Native valve endocarditis normally presents with fever and only later in its course demonstrates dysfunction of the affected valve. We describe a case of endocarditis due to Neisseria subflava, a Gram-negative diplococcal saprophyte of the oral cavity, which was unsuspected clinically and found unexpectedly during a mitral valve operation performed for symptomatic prolapse with regurgitation.

Endocarditis, Bacterial↗
PubMed1995

Analysis of risk factors for excess mortality after aortic valve replacement.

OBJECTIVES: This study sought to identify risk factors for both late observed and late "excess" mortality after aortic valve replacement and to examine the causes of late mortality. BACKGROUND: Because operative mortality after aortic valve replacement is very low, the timing of surgical intervention should focus on maximizing long-term survival. However, to judge the effect of valve replacement on long-term survival in an elderly population, it is important to separate mortality resulting from extraneous causes (background mortality) from disease-related mortality (excess mortality). Background mortality can be estimated by calculating expected mortality on the basis of age and gender. METHODS: From 1966 to 1986, 643 patients (mean age 59.6 years, 138 [21%] > or = 70 years old) underwent aortic valve replacement, 129 of whom also underwent coronary bypass grafting; 594 patients survived > or = 30 days after the procedure. The overall operative mortality rate for isolated aortic valve replacement decreased over time from 25.5% (1966 to 1972) to 2.6% (1980 to 1986). Cumulative total follow-up after discharge was 3,603 patient-years. Multivariate analysis was performed for both observed and excess mortality. RESULTS: Risk factors for both observed and excess mortality were previous myocardial infarction, coronary artery disease, heart failure and atrial fibrillation. Although age > or = 70 years was a risk factor for observed mortality (hazard rate ratio [HRR] 2.4, 95% confidence interval [CI] 1.6 to 3.7), it was not a risk factor for excess mortality. In contrast, isolated aortic regurgitation was an important risk factor for excess mortality only (HRR 3.8, 95% CI 1.3 to 11.2). Late mortality was valve related in 22% of patients, including sudden death in 7% and cerebral vascular accidents in 7%. Congestive heart failure was an important cause of death (21%) irrespective of the time elapsed since aortic valve replacement. In patients with aortic regurgitation, congestive heart failure was the main cause of death (38%); in patients with aortic regurgitation and preoperative heart failure or severe left ventricular dysfunction, heart failure was the cause of death in 44% and 63%, respectively. CONCLUSIONS: Analysis of excess mortality revealed that older age in itself is not a risk factor for late mortality after aortic valve replacement. Aortic regurgitation carries a high risk, probably associated with left ventricular dysfunction at the time of operation. Earlier operation may be warranted in such patients.

Age Factors↗