Biomedical subjects

G J Ensing

Publications and source records attributed to G J Ensing.

47 records · Page 3Linked to original sources

PubMed1986

In vitro function of radiocolloid-labelled monocytes.

Human monocytes in a mononuclear cell suspension were labelled specifically using 111In-Fe-colloid, with the ultimate goal of using them for monocyte kinetic studies in haematological malignancies. In order to examine the function of the labelled monocytes, in vitro function tests were performed on cell suspensions containing labelled or non-labelled monocytes. These tests were: phagocytosis of opsonized zymosan particles and ability of monocytes to mature into macrophages when cultured in glass tissue chambers. There were no significant differences in in vitro function between labelled and non-labelled monocytes. Cell viability was always greater than 90%. During culture, a rapid loss of monocyte-bound radioactivity took place. We conclude that the labelling procedures do not interfere with subsequent in vitro cell function. However, because of the rapid loss of cell bound radioactivity in vitro, monocytes labelled by this method do not seem suited for long-term studies in vivo.

Colloids↗

PubMed1985

Technique of labeling monocytes with 111In-Fe colloid for use in humans.

In order to follow monocyte kinetics in hematologic malignancies by means of radioactive labeling, three conditions are necessary: (a) no loss of monocytes during separation, (b) specific labeling of monocytes, and (c) normal functional capacities of the labeled monocytes. In this report a method is described that fulfills the first two conditions and can be executed with maintenance of sterility. Cell labeling was performed using a mononuclear cell suspension consisting of monocytes (20%-50%), lymphocytes (50%-80%), and with minor contamination by granulocytes, thrombocytes, and erythrocytes. This cell suspension was obtained by centrifugation of a leukocyte suspension on a gradient of 16% wt/vol and 22% wt/vol human serum albumin solutions. The recovery of monocytes with this enrichment method approached 100%. Monocytes were labeled by endocytosis of 111In-Fe colloid; monocytes were labeled significantly higher than lymphocytes (P less than 0.001) and granulocytes (P less than 0.01) (Wilcoxon's two-sample test). Cell viability after labeling was greater than 90%.

Autoradiography↗

PubMed1984

Is the relative 99mTc-DMSA clearance a useful marker of proximal tubular dysfunction?

The clearance of 125I-sodium iothalamate, 131I-sodium hippurate, 99mTc-DMSA, and beta 2-microglobulin were determined in 20 patients with proven or suspected proximal tubular dysfunction and in 18 control patients with various renal diseases. A clear distinction in the relative 99mTc-DMSA clearance was observed between patients with proximal tubulopathy (14%-35%) and control patients (less than 14%). A similar difference between the two groups was found in the relative beta 2-microglobulin clearance. Nine patients with proximal tubulopathy showed an elevated filtration fraction versus only two control patients. The renal handling of 99mTc-DMSA seems to be an indicator of proximal tubular function.

Adolescent↗

PubMed1983

Low renal uptake of 99mTc-DMSA in patients with proximal tubular dysfunction.

In nine patients with different types of proximal tubulopathy and a nearly normal glomerular filtration rate a low uptake of 99mTc-DMSA in kidneys was found. The underlying mechanism seems to be an increased urinary excretion of 99mTc-DMSA. This radiopharmaceutical might be used as a marker of proximal tubular dysfunction.

Adolescent↗

PubMed1983

Lymphocyte characteristics and function in paroxysmal nocturnal haemoglobinuria.

In six patients with paroxysmal nocturnal haemoglobinuria (PNH) lymphocyte studies were performed to investigate whether the observed immunological dysfunction could be ascribed to a defect in lymphocytes as result of the PNH characteristics, or to an imbalance between T-cell subsets. The PNH characteristics were studied by means of the effect of serum and acidified serum on Indium111-oxine labelled lymphocytes. No increase in release of Indium111-oxine was found when lymphocytes were exposed to acidified sera. Thus a complement mediated lymphocyte lysis in PNH could not be demonstrated. T-cells were defined by monoclonal antibodies, directed at total T-cells (OKT3), helper T cells (OKT4) and suppressor/cytotoxic T-cells (OKT8). In two of the six patients a decreased proportion of OKT3 cells was found, while a significantly depressed ratio of OKT4/OKT8 cells was present in the whole group. No obvious correlation was found between a functional assay - the concanavalin-A suppressor cell activity - and the ratio of OKT4/OKT8 positive cells. It is concluded that the PNH characteristics could not be demonstrated in the lymphocytes; and that the immunological dysregulation in PNH may be ascribed to an imbalance of T-cell subsets, while a decreased number of monocytes, defined by the monoclonal antibody OKM1, may contribute to this defect.

Antibodies, Monoclonal↗

PubMedDate not supplied

Thrombus formation in the native aortic root in patients with hypoplastic left heart syndrome.

Thrombus formation in the native aortic root is a rare but potentially life-threatening complication in patients with hypoplastic left heart syndrome. The native aortic root in these patients serves as a conduit for the retrograde filling of the coronary arteries. Thrombus in this location could result in myocardial ischemia. We present three cases of native aortic root thrombosis at our institution with clinical presentations ranging from asymptomatic to sudden cardiac arrest. Our experience with these patients argues for careful and consistent evaluation of the native aortic root regardless of clinical symptoms.

Adult↗

PubMedDate not supplied

Dynamic three-dimensional echocardiographic reconstruction of congenital cardiac septation defects.

Dynamic three-dimensional echocardiographic reconstructions of 27 cardiac septation defects were performed in 19 sedated infants and children. Using a subxiphoid rotational scanning approach, complete visualization of the entire shape and breadth of the defect was attained in 11 of 16 ventricular septal defects and 9 of 11 atrial septal defects. This technique enabled the operator to cut slices from the three-dimensional block of echocardiographic data in order to present septation defects in a region- or lesion-oriented fashion. Poor baseline two-dimensional image quality and certain small septation defects that were readily obscured by nearby structures led to inadequate three-dimensional reconstructions. The application of dynamic three-dimensional echocardiography for assessment of cardiac septation defects uniquely provided (1) the ability to present en face views of atrial and ventricular septal defects; and (2) a means by which intracardiac anatomy can be displayed in a region- and lesion-oriented fashion for interventional and surgical planning purposes.

Adolescent↗

PubMedDate not supplied

Rings, slings and such things: diagnosis and management with special emphasis on the role of echocardiography.

Vascular anomalies of the aorta and pulmonary artery that cause tracheal, esophageal, or tracheoesophageal compression form an important group of congenital cardiovascular malformations. The diagnostic approach to the patient with possible vascular ring is variable. This article presents a systematic approach to the evaluation and management of this fascinating group of malformations, with special emphasis on the role and limitations of echocardiography. Using this approach between September 1990 and March 1992, we identified and defined vascular anomalies of aorta and pulmonary artery in eight children.

Aorta, Thoracic↗

PubMedDate not supplied

Coronary artery abnormalities in children.

Although coronary artery abnormalities are somewhat rare in children, they constitute a population at significant risk for morbidity and/or mortality. The expeditious and accurate diagnosis of these lesions is imperative for optimum management. The ability of two-dimensional and Doppler echocardiography to accurately evaluate coronary artery abnormalities in children will be discussed under three headings: (1) major congenital coronary artery anomalies, (2) coronary artery anomalies associated with specific congenital heart lesions, and (3) acquired coronary artery abnormalities.

Child, Preschool↗

PubMedDate not supplied

A systematic approach to echocardiographic image acquisition and three-dimensional reconstruction with a subxiphoid rotational scan.

Rotational scanning from the subxiphoid position is an image acquisition technique used for reconstruction of dynamic three-dimensional echocardiographic images in infants and small children. The orientation of the heart within the three-dimensional data set is variable and dependent on the image plane at which rotational scanning was initiated. We describe an image acquisition technique that standardizes the orientation of the heart within the three-dimensional data set, thereby permitting a systematic approach to the reconstruction of three-dimensional renderings. Thirteen infants and small children with congenital heart disease were studied by this approach. Illustrative examples are provided. The average time required to derive a three-dimensional rendering was 37 +/- 9 minutes. We conclude that subxiphoid rotational scanning by a systematic approach to image acquisition and reconstruction can be applied successfully to the derivation of three-dimensional renderings of congenital cardiac defects.

Child↗

PubMedDate not supplied

Patent ductus arteriosus in neonates.

Patency of the ductus arteriosus is one of the more common problems of the neonate. Although the ductus arteriosus usually closes within the first days of life, persistent patency can complicate the clinical status of a newborn. The ductus arteriosus also may play a role in the pathophysiology of persistent pulmonary hypertension of the newborn and in some forms of congenital heart disease. Diagnosis of patent ductus arteriosus can be suspected clinically but should be verified by echocardiography before treatment. Accurate diagnosis, early intervention and proper treatment are necessary to decrease the immediate risks and minimize the potential for long-term complications.

Contraindications↗