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Biomedical subjects

E Bos

Publications and source records attributed to E Bos.

At least 91 records · Page 5Linked to original sources
PubMed1992

Polyclonal versus monoclonal rejection prophylaxis after heart transplantation: a randomised study.

Recent studies comparing the effects of induction therapy with polyclonal antilymphocyte globulins (ALG) or with monoclonal T-cell-specific antibodies are not unanimous. Therefore, 55 heart recipients were allocated to either 7-day courses of polyclonal ALG (n = 28) or of monoclonal OKT3 (n = 27). Additionally, azathioprine and low dose steroids were given. There were no severe side effects after OKT3; the course of ALG, however, had to be discontinued in 20 patients because of extensive flares. No differences between the two groups were found in freedom from rejection or in the incidence of infection. The 1- and 2-year survival was 96% in both groups. Although monoclonal and polyclonal induction therapies are equally effective for rejection prophylaxis, OKT3 may be preferred because of a lack of important side effects. However, the fact that a shorter course of ALG is equally effective may be in favour of ALG.

Adolescent↗
PubMed1992

Donor directed cytotoxicity of cardiac graft infiltrating cells during cytomegalovirus infection.

We investigated whether cytomegalovirus (CMV) infection had an effect on donor directed cytotoxicity of cardiac graft infiltrating cells. The group we studied comprised 89 heart transplant recipients. Thirty eight showed signs of CMV infection, and in 27 of them cytolytic activity of biopsy-derived cultures could be tested during the infection. Fifty-one patients had never had CMV infection, and they were used as the control group. Eight patients had a primary, and 19 a secondary infection. We found that during CMV infection, both primary and secondary, a significantly higher proportion of the biopsy-derived cultures showed cytotoxicity against donor antigens (P < 0.01 when compared to the control group). In secondary infections, this was only due to an increase in donor class I directed cytotoxicity, while in primary infections a significant increase of class II directed cytotoxicity was also found (P < 0.005 when compared to secondary infection).

Cell Culture Techniques↗
PubMed1992

The influence of HLA-mismatches on phenotypic and functional characteristics of graft infiltrating lymphocytes after heart transplantation.

We studied the influence of HLA mismatches on T lymphocyte cultures that were derived from endomyocardial biopsies (EMB) from 118 heart transplant recipients. From patients with DR mismatches, the majority of the EMB-derived cultures were dominated by CD4, while in patients without DR mismatches, CD8 was the predominant T cell subset. The majority (75%) of the cultures were cytotoxic against donor antigens. A significantly (P < 0.005) lower proportion of the cultures showed cytotoxicity (36%) against HLA-A antigens when compared to HLA-B (53%) or HLA-DR (49%). A dose effect phenomenon was detected for all HLA antigens, including HLA-A: a higher number of A, B or DR mismatches resulted in a higher number of cytotoxic cultures directed against these antigens. B and DR matching had the greatest influence on 6 month freedom from rejection. Both our experimental and clinical data indicated that HLA matching played a role in the immune response against a transplanted heart.

Biopsy↗
PubMed1992

5-Hydroxytryptamine-induced contractions of the human isolated saphenous vein: involvement of 5-HT2 and 5-HT1D-like receptors, and a comparison with grafted veins.

The receptors mediating the contractile effect of 5-hydroxytryptamine (5-HT) on the human isolated saphenous vein, obtained from 42 patients undergoing coronary bypass surgery, have been further characterized using a number of 5-HT-related drugs. The rank order of agonist potency was 5-carboxamidotryptamine (5-CT) approximately 5-HT greater than methysergide approximately sumatriptan approximately alpha-methyl-5-HT approximately 5-methoxy-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indolesuccinate (RU 24969) approximately 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI) greater than 2-methyl-5-HT greater than 8-hydroxy-2(di-n-propylamino)tetralin (8-OH-DPAT). Flesinoxan was inactive as an agonist. Ketanserin (1 mumol/l) hardly affected sumatriptan-induced contractions but it caused a rightward shift of the upper part of the concentration-response curve of 5-HT and 5-CT. The same concentration of ketanserin caused a parallel rightward shift of the concentration-response curves of alpha-methyl-5-HT and DOI with pKB values of 7.1 and 7.1, respectively. The responses to sumatriptan were antagonized by methiothepin (0.1 mumol/l), metergoline (0.1 and 1 mumol/l), rauwolscine (1 mumol/l) and cyanopindolol (1 mumol/l); the calculated pKB values were 7.3, 6.9, 7.3, 6.7 and 6.5, respectively. Contractions to 5-HT were antagonized by methysergide (1 mumol/l), methiothepin (0.1 mumol/l; pKB = 7.1), ICS 205-930 (1 mumol/l; pKB = 5.9) and flesinoxan (30 mumol/l; pKB = 5.3). Remarkably, the contractions elicited by 2-methyl-5-HT were not attenuated by ICS 205-930, but were antagonized by methiothepin (0.1 mumol/l) and, more markedly, by ketanserin (1 mumol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1992

The demographic impact of AIDS in sub-Saharan Africa: short- and long-term projections.

"This paper describes the methodology used to incorporate AIDS mortality in recently revised World Bank population projections.... The paper first reviews different approaches for projecting AIDS and its demographic consequences. This is followed by a summary of an epidemiological model that simulates the spread of HIV used in this analysis, and a demographic model that translates mortality from AIDS into population outcomes. These models are then used in a set of simulations, from which the effect of current HIV prevalence on projected future mortality is extracted. Finally, the extracted equations linking current HIV prevalence with future mortality indicators are applied to sub-Saharan countries with a measurable level of current HIV prevalence."

Acquired Immunodeficiency Syndrome↗
PubMed1992

Management of fixed subaortic stenosis: a retrospective study of 57 cases.

Although recommended by several investigators, the benefit of early surgery in patients with fixed subaortic stenosis has not been proved. Findings were reviewed of 57 patients with isolated fixed subaortic stenosis, including 27 surgically treated patients, with special emphasis on the occurrence of aortic regurgitation during a mean follow-up period of 6.7 years. The number of patients with aortic regurgitation increased preoperatively in the total group (23% at diagnosis to 54% after 3.7 years of follow-up). The prevalence of aortic regurgitation in the 27 surgically treated patients was higher (81%) than that in the nonsurgically treated group but remained unchanged after a mean postoperative period of 4.7 years. In all patients but one, aortic regurgitation remained of minor hemodynamic significance. One patient died during follow-up. After surgery, 15 patients (55%) showed a relapse; 11 redeveloped a subvalvular pressure gradient greater than 30 mm Hg and discrete subvalvular ridges (range 6 months to 24 years after surgery, mean 7 years). In those patients with fixed subaortic stenosis, follow-up did not reveal any benefit from early surgery. The unpredictable course and sometimes very severe progression of this disease make frequent and careful follow-up necessary.

Adolescent↗
PubMed1992

Conversion of lusoric artery into right subclavian artery in one-stage neonatal repair of aortic arch anomalies and intracardiac defects.

In 2 patients, a lusoric artery was compressing the mediastinal structures during a one-stage repair of type B aortic arch interruption and ventricular septal defect. In order to prevent the long-term complications of sacrifice of the subclavian artery, the lusoric artery was not simply divided but converted into a regular right subclavian artery by re-implantation of the abberant vessel at the origin of the right carotid artery during the one-stage repair. At follow up, both patients have normal right radial arterial pulsations. In one patient, angiography was repeated and confirmed a well functioning right subclavian artery. Conversion of a lusoric artery into a right subclavian artery during one-stage repair of aortic arch anomalies and intracardiac defects is not only feasible but also indicated to preserve subclavian artery function and to prevent compression of the mediastinal structures by a vascular ring.

Aorta, Thoracic↗
PubMed1992

Transoesophageal echocardiographic evaluation of atrial morphology in children with congenital heart disease.

In a prospective study, atrial morphology was evaluated by both transoesophageal and precordial echocardiography in 86 unoperated children with congenital heart disease (age range = 0.2 to 14.8 years, mean = 3.8 years) to determine what advantages, if any, might be inherent in the transoesophageal approach. The information derived from both ultrasound approaches was correlated and compared to information obtained during subsequent cardiac catheterization (78 patients) and, or, surgical inspection (53 patients). Atrial appendage morphology and hence atrial situs was determined by transoesophageal echocardiography in every case (82 solitus, two right atrial isomerism, two left atrial isomerism). In addition, the transoesophageal approach indicated left juxtaposition in four patients, compared to only one by precordial examination. Probe patency of the foramen ovale was correctly predicted in 21 patients by transoesophageal imaging, but in only 10 by precordial imaging. In two children significant secundum defects, undetected by the precordial route, were identified. Multiple atrial septal defects were correctly defined in four patients by transoesophageal study but in only one by precordial study. Sinus venosus defects were documented in four by the transoesophageal approach, but in only one by the precordial. Primum defects were equally well documented (nine patients) by either technique, but the associated valve leaflet morphology was better documented by transoesophageal study in 5/9. A subtotal cor triatriatum was diagnosed in one child only by transoesophageal investigation. Transoesophageal echocardiography allows a much more detailed evaluation of atrial morphology than precordial imaging even in infants. It provides direct diagnosis of atrial situs, detection of juxtaposed atrial appendages and improved demonstration or definitive exclusion of atrial septal defects.

Adolescent↗
PubMed1992

A modification of staged septation for univentricular atrioventricular connection.

A case is reported in which is described a modification of staged septation for univentricular atrioventricular connection with double-inlet left ventricle and left-sided rudimentary outlet chamber beneath the aorta. This modification diminishes the risk of atrioventricular conduction disturbances by gluing the perforated septation patch on the myocardium in the area overlying the central conduction system. Fixation of the patch was facilitated by exact fitting of the patch in this area, by ample contact of the patch and the myocardium in this area, and by immobilization of the patch because of equal pressures on both sides because of the perforation of the patch. In addition, this modification facilitates evenly drawing in of the ventricular free wall because already, in the first stage, the complete circumference of the patch is fixed, defining the maximal contribution of prosthetic material to the newly created septum.

Double Outlet Right Ventricle↗
PubMed1991

[11-year survival following aortocoronary bypass surgery].

To evaluate longterm survival after a first aortocoronary bypass operation we followed up all such patients with operations between July 1971 and June 1980. Included were 1041 patients, mean follow-up time was 11 years (8.5-17.4). Data were complete in 98%. The perioperative mortality equalled 1.2%, survival probability at 5 and 10 years was 92% and 77%, respectively. The yearly mortality rate increased from the fifth year onward up to 5% in the tenth. Of the deceased patients 72% had a cardiac cause of death. Extent of vascular involvement, quality of left ventricular function and age at operation had an important influence on survival probability. The aortocoronary bypass operation is a safe procedure, with a good prognosis for survival, but does not prevent cardiac death in the future.

Age Factors↗
PubMed1991

Surgery for Ebstein's anomaly: the clinical and echocardiographic evaluation of a new technique.

Ten consecutive patients (age range 4 to 44 years, mean 22) underwent surgical repair of Ebstein's anomaly by vertical plication of the right ventricle and reimplantation of the tricuspid valve leaflets. No patient died during or after operation. Intraoperative postbypass echocardiography documented a good result in nine patients but severe tricuspid regurgitation in one patient, who then underwent prosthetic valve replacement during a second period of cardiopulmonary bypass. Two of four patients who had had right ventricular papillary muscle dysfunction in the early postoperative period showed improved papillary muscle function with concomitant reduction of tricuspid regurgitation 6 months later. All patients were evaluated clinically and by echocardiography 2 to 23 months later. All patients showed clinical improvement, seven by one functional class and three by two classes. All were in sinus rhythm. The mean cardiothoracic ratio decreased by 6% (p less than 0.05). On bicycle ergometry performed in six patients, peak oxygen consumption exceeded 20 ml/kg per min in five. Tricuspid regurgitation diminished in eight patients (by three grades in two patients, by two grades in five and by one grade in one patient); it remained unchanged in two. Comparison of preoperative and postoperative pulsed Doppler flow velocities across the pulmonary valve showed an increase in the peak velocity of flow across the valve (mean 83 +/- 14 versus 97 +/- 11 cm/s, p less than 0.005) and a decrease in the time to peak velocity (mean 130 +/- 16 versus 91 +/- 23 ms, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

An unusual problem during surgical removal of a broken guidewire.

At operation, it proved impossible using traction alone to remove an angioplasty guidewire that was lodged in an intermediate artery. The problem was solved by passing a Teflon catheter over the wire, thus protecting the left main coronary artery while freeing the entrapped distal end of the guidewire.

Aged↗
PubMed1991

Alloreactive lymphoid infiltrates in human heart transplants. Loss of class II-directed cytotoxicity more than 3 months after transplantation.

From 535 endomyocardial biopsies (87 heart transplant recipients) 283 cell cultures could be generated. All cultures tested contained T lymphocytes and in most cases CD4 was the predominant phenotype at any time posttransplant. A significantly higher proportion of CD8-dominated cultures was found among cultures from biopsies without myocytolysis. In the first 3 months post transplant 57% of cultures showed cytotoxicity against both class I and class II mismatched donor major histocompatibility complex (MHC) antigens, changing to an incidence of 33% at greater than 90 days. This proved to be due to a significant decrease in the number of cultures with human leukocyte antigen class II-directed cytotoxicity. This study shows that early after transplantation a heart transplant is infiltrated with activated donor-specific cytotoxic T cells which recognize a broad spectrum of mismatched donor MHC antigens, and that in time this spectrum becomes more restricted.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Transesophageal echocardiography in evaluation and management after a Fontan procedure.

Transesophageal echocardiography was used in 18 patients (aged 1.6 to 34 years, mean age 12.6) to assess the immediate (5 patients) or intermediate (13 patients) results after a Fontan-type procedure. The findings were correlated with precordial echocardiographic (all patients) and cardiac catheterization (11 patients) data. Atrial shunting was documented by transesophageal studies in three patients (precordial in one patient). In two patients it was confirmed by cardiac catheterization; the third underwent reoperation based on the transesophageal study alone. Pulmonary artery obstruction was documented in three patients (precordial in one patient) and was confirmed by subsequent cardiac catheterization in all. Evaluation of anterior Fontan connections was successful in 5 of 8 patients (precordial in 6 of 8), and posterior connections in 10 of 10 patients (precordial in 5 of 10). A Glenn shunt could be evaluated in eight of nine patients (precordial in three of nine). Thrombus formation was detected by transesophageal studies in three patients (precordial in one patient); repeat studies were used to evaluate thrombolytic therapy in two. Atrioventricular valvular regurgitation (11 of 18 patients) was better defined by transesophageal than by precordial studies (5 of 18). A coronary artery fistula was identified in two cases (precordial in none). Transesophageal pulsed Doppler interrogation of pulmonary artery and pulmonary vein flow patterns consistently allowed a detailed evaluation of the Fontan circulation. Transesophageal echocardiography is an important diagnostic and monitoring technique after the Fontan procedure. In this series, it was far superior to precordial ultrasound evaluation and of substantial additional value to cardiac catheterization.

Adolescent↗
PubMed1991

One stage repair of aortic arch anomalies and intracardiac defects.

Between August 1985 and May 1990, 27 neonates and infants underwent combined correction of intracardiac and aortic arch anomalies through a median sternotomy. Coarctation (CoA) was combined with VSD (6), AVSD (2), Taussig-Bing (TB) heart (5), transposition of the great arteries (TGA) (1), TGA + VSD (2), congenitally corrected TGA + VSD (1) and VSD + myxoid stenotic outlet valves (1). Interrupted aortic arch (IAA) was combined with VSD (10) and TB heart (1). Two patients had IAA type B as well as CoA. Age at operation varied from 2 to 243 days with a mean age of 51 days. Twenty patients (70%) were younger than 30 days. One TGA + VSD and all TB hearts had maligned outlet septum and right ventricular outflow tract obstruction (RVOTO). Posterior outlet septum deviation and left ventricular outflow tract obstruction (LVOTO) occurred in 8 patients with malalignment VSD and IAA (7) or CoA (1). Aortic arch reconstruction was performed using extended end-to-end anastomoses. In 3 patients, arch hypoplasia necessitated patch implantation. VSDs were closed through the right atrium unless the anatomy dictated otherwise. One TB heart was reconstructed with a Kawashima procedure. All other TB hearts and all TGAs were corrected with arterial switch operation. Obstructing outlet septum was resected whenever necessary. Follow-up was complete and included echo-Doppler control. Eleven patients had postoperative heart catheterisation. Early mortality was 18.5% (5 patients). Persisting LVOTO or RVOTO was responsible. There was no late mortality. Five patients were reoperated upon: 3 for stenotic anastomoses and 2 for a subaortic membranous stenosis. Successful balloon dilatation of recoarctation was performed four times.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗