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Biomedical subjects

F Van de Vyver

Publications and source records attributed to F Van de Vyver.

6 recordsLinked to original sources
PubMed1993

Photochemically-induced cerebral infarction in the rat: comparison of NMR imaging and histologic changes.

The evolution of a photochemically induced cerebral thrombotic infarction was followed in rats during the first week after the insult by means of NMR imaging and histology. Heavily T2-weighted images provided an excellent lesion detection and a high specificity for the discrimination of different histological abnormalities. The T2-weighted images showed a brain lesion evolving during the first 24 h from a homogeneous hyperintense area, histologically corresponding to diffuse vasogenic and cytotoxic oedema with concomitant neuronal necrosis, to an iso-intense area with a hyperintense seam, which microscopically correlated with increased vascular permeability at the periphery of the lesion. The hyperintense seam was observed up to day 7, but at that time coincided with gliomesodermal repair reaction which could be verified histochemically and ultrastructurally. It may be concluded that NMR-micro-imaging at a moderately high field, enables early detection and adequate follow-up of small cerebral infarctions in rats.

Animals↗
PubMed1992

Noninvasive in vivo 13C-NMR spectroscopy of a 13C-labeled xenobiotic in the rat.

This study demonstrates that the xenobiotic product, 1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloro-3-13C-propane can be monitored in the liver of an intact animal by in vivo 13C surface coil NMR spectroscopy after intraperitoneal administration. The carbon-13 label could be detected after a single dose of only 200 mg/kg of the product. The intrahepatic changes of the signal intensity of the labeled product were monitored as a function of time. No signals corresponding to metabolites could be detected.

Animals↗
PubMed1991

High resolution NMR imaging: Gd-DTPA labeled enzyme as a probe for permeability studies in polyacrylamide gels.

The penetration of horse liver alcohol dehydrogenase (HLAD) molecules into polyacrylamide gel beads, which are used to immobilize the enzyme, was studied. HLAD was labeled with gadolinium diethylene-triamine-pentaacetic acid (Gd-DTPA), using the N-hydroxy-succinimide active ester of DTPA as a chelating agent. The HLAD-(Gd-DTPA)27 has a 3.7-fold larger longitudinal (R1) and a 14-fold larger transversal relaxivity (R2) (at 2.4 T) than the plain Gd-DTPA. A series of dry polyacrylamide gel beads, with total monomer concentration ranging from 5% to 30% were synthesized and swollen in a buffered solution of HLAD-(Gd-DTPA)27. The gel beads were examined with high resolution NMR imaging. The T1- and T2-weighted images revealed that the permeability for the labeled HLAD decreased with increasing total monomer concentration of the gel beads. These imaging results correlate fairly well with the enzymatic reactivities measured for the same range of gel beads but swollen in a solution of non labeled HLAD and NAD+ (nicotinamide adenine dinucleotide). It is concluded that Gd-labeling can be used to monitor the distribution of weakly concentrated, water soluble products in a solid matrix.

Acrylic Resins↗
PubMed1987

Applications of laser microprobe mass analysis in medicine.

An instrument for laser microprobe mass analysis (LAMMA) has been available for applied research for several years. The value of this sensitive microanalytical technique has been demonstrated in various fields of science, including medicine and biology. The LAMMA instrument comprises two laser systems. The first is a weak continuous pilot laser that can be aimed at a region of interest of the sample, e.g., a histological microtome section, using a light microscope. The second is a powerful pulsed laser that can evaporate the selected area. The generated ions are then analyzed in a time-of-flight mass spectrometer. The advantages of LAMMA present new perspectives in biomedical research. Elements can be located and analyzed down to the parts per million-level with a 1 micron spatial resolution. Speciation and/or fingerprinting of (in)organic molecules may be obtained. However, the technique is destructive, the quality of the light-microscopic view is poor, and quantification is still under investigation. In this review, the analytical characteristics of LAMMA are evaluated, including instrumental features, detection sensitivity, ionization parameters, molecular speciation, and quantification. Applications of LAMMA in medicine are reviewed, covering the microanalysis of a wide range of physiological and toxic constituents (alkali metals, calcium, aluminum, titanium, fluorine and iodine, heavy metals, transition elements, and molecular compounds).

Humans↗