Biomedical subjects

E Mandrusov

Publications and source records attributed to E Mandrusov.

5 recordsLinked to original sources

PubMed2006

Comparison of transendocardial and retrograde coronary venous intramyocardial catheter delivery systems in healthy and infarcted pigs.

UNLABELLED: We compared two routes for myocardial delivery of therapeutics, transendocardial (TE) delivery with an intramyocardial injection catheter, and retrograde coronary venous (RCV) delivery with a balloon occlusion catheter in the interventricular vein. METHODS: TE and RCV injection of 15 microM, neutron-activatable microspheres was compared in healthy pigs (Group I, n = 3), pigs with a 1-week-old myocardial infarction (MI; group II, n = 5), and pigs with a 2-weeks-old MI (group III, n = 4). The MI was induced by a 1-hr balloon occlusion in the LAD. Both methods were compared in the same animal using different microspheres. The RCV catheter allowed for continuous measurement of distal pressure and 2.5 x 10(6) microspheres were injected in 10 ml at 300 mmHg above balloon occlusion pressure. The TE injections were targeted to the infarct zone and 2.5 x 10(6) microspheres were distributed over 10 injections of 200 microl. RESULTS: The retention of microspheres decreased with increase in MI age, but was comparable between devices within the groups. RCV delivery resulted in (14.3 +/- 0.9)% microsphere retention in Group I, (10.3 +/- 0.2)% in Group II, and (6.4 +/- 0.1)% in group III (P < 0.05 versus group I). Microsphere retention after TE was (15.1 +/- 0.7)% in group I, (18.9 +/- 0.6)% in group II, (4.1 +/- 0.1)% in Group III (P < 0.05 versus groups I and II). The RCV catheter delivered primarily to midventricular, antero-septal segments, whereas TE targeted apical areas predominantly. CONCLUSIONS: Delivery efficacy was comparable between devices in each group however RCV targeted midventricular areas whereas TE targeted apical areas.

Anastomosis, Surgical↗

PubMed1996

Detection of specific plasma proteins on surfaces by immunospecific adhesion of dyed polystyrene beads.

This paper describes and evaluates a method for quantifying the amounts of specific plasma proteins adsorbed to biomaterial surfaces. In particular, it demonstrates that macroscopic images ('stains'), that assess the spatial distribution of albumin, IgG, fibrinogen, and HMK (high molecular weight kininogen), can be obtained over areas of at least 12 cm2 using immunospecific adhesion of dyed polystyrene beads. Stain intensities, measured with a scanner and an image analysis system, were found to quantify the amount of specific protein in the solution used to coat the surfaces. Results obtained with the proposed method produced single protein isotherms for albumin, immunoglobulin G (IgG) and fibrinogen that followed Langmuir-like adsorption behavior and were similar to previously published isotherms. The HMK isotherm also exhibited Langmuir-like adsorption behavior. The proposed method also detected the presence of an expected maximum in the adsorption of fibrinogen onto glass as a function of plasma dilution. Adsorption of fibrinogen out of 6.4% plasma onto glass from a separated flow produced results indicating the quantity as well as the location of fibrinogen at the boundary of the separated region. This result confirmed the utility of the proposed method for detecting spatial distributions of specific proteins adsorbed from plasma in practical devices.

Adsorption↗

PubMedDate not supplied

Membrane-based cell affinity chromatography to retrieve viable cells.

A novel scheme for the separation and live recovery of one cell type from a mixture of cells using a cell affinity chromatography (CAC) system is demonstrated. An anti-murine IgG was chemically immobilized to a cellophane support via a carbonyldiimidazole (CDI) link. Murine splenocytes flowed over the support, and B-cells were allowed to attach at a shear rate of 15 s-1. Once loading was terminated, the support was washed at a shear rate of 315 s-1 to remove nonspecifically bound cells. Elution of the B-cells was initiated by the transmembrane diffusion of hydrochloric acid (pH 1), supplied to the side of the membrane opposite the cells. At the same time, a shear flow of normal saline was established on the cell side of the membrane, and cells, freed by acid, were retrieved. Results showed that, on average, 250 cells/mm2 attached to antibody immobilized on cellophane surfaces, at a shear rate of 15 s-1, and that attached cells were successfully displaced by acid supplied to the side of the membrane opposite that holding the cells. On average, at least 60% of the B-cells removed by this elution appeared viable, based on a Trypan Blue dye exclusion assay.

Animals↗

PubMedDate not supplied

Effects of secondary flow caused by a curved channel on plasma protein adsorption to artificial surfaces.

The effects of secondary flow induced by a curved channel on fibrinogen deposition and replacement on a glass surface were studied. Platelet adhesion to surface-bound fibrinogen was also studied to indicate how secondary flow may affect thrombogenesis on artificial surfaces. A saline pre-wetted channel with straight and curved sections was exposed to flowing plasma at a Reynolds number of 28.6. Results show that fibrinogen deposited on the surface at a shear rate of 175 s-1 was replaced faster in regions of secondary flow (Dean numbers from 11 to 19) than in adjacent regions of shear flow. Platelets adhered only to those surfaces where fibrinogen had been detected.

Adsorption↗

PubMedDate not supplied

Separated flows in artificial organs. A cause of early thrombogenesis?

Separated flow is unavoidable in artificial blood-wetted devices. Surfaces bound by separated flows cause abnormal protein adsorption, then platelet adhesion and activation, and eventually thrombogenesis and embolization. A prolonged abnormal adsorption pattern is expected, especially in separated flows, as blood first displaces a wetting liquid during start-up of a device. The authors obtained patterns of immunoglobulin G (IgG), fibrinogen, and high molecular weight kininogen (HMK) adsorption in and near a separated flow. The flow was induced in flowing saline, replaced at time zero by plasma. The separated flow was induced behind a 4 mm bar introduced into a steady shear flow (Re = 26.4) in an apparatus designed so that the surface behind the bar was a standard glass microscope slide. The staining technique revealed the distribution of each protein of interest over the surface of the slide, and was applied to slides residing in the flow for 1, 5, 10, 30, and 60 min after the introduction of plasma (final dilution, 3.5% and 8.5%). Results show the expected, rapid disappearance of fibrinogen from surfaces near (but not in) the separated region, and prolonged appearance and even more prolonged disappearance of fibrinogen from the surface bounding the separated region. Slides removed from the apparatus, when exposed to a platelet suspension, showed that platelets adhered where fibrinogen was present on the surface.

Adsorption↗