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Biomedical subjects

A Meulemans

Publications and source records attributed to A Meulemans.

10 recordsLinked to original sources
PubMed1992

Diffusion from gel in brain: modelisation and identification.

A mathematical model is proposed for describing the mechanism of diffusion from gel (Tissucol) into the extracellular space. After diffusion of the antibiotic in one dimension, the gradient concentration was determined with microvoltametric electrodes. These microelectrodes measure the free diffusible form of electroactive antibiotics in the extracellular brain space. The aim of this study was to find simultaneously the coefficient of diffusion and extraction of some antibiotics (in our case the Fotemustin) using the Alienor Algorithm. These coefficients are useful for predicting the concentration gradient into abscesses, fibrin, etc.

Algorithms↗
PubMed1992

A model of cefoperazone tissue penetration: diffusion coefficient and protein binding.

The apparent diffusion coefficient of a bound drug, cefoperazone, was studied. The protein binding of cefoperazone was studied by voltammetry, a technique which permitted instant measurements. The apparent diffusion coefficients were similar in agar and fibrin and lower in rat brain tissue. The influence of protein on the value of the apparent diffusion coefficient was negligible. The hypothesis that only the free drug diffuses was supported. The percentage of binding determined by voltammetry corresponded to the true concentration of drug which diffuses and is much lower than the percentage of binding determined by the ultrafiltration centrifugation method. This discrepancy could be explained by the rate of dissociation of the protein-drug complex.

Animals↗
PubMed1991

Magnesium deficiency as a cause of acute intractable seizures.

Clinical and experimental investigations have shown that magnesium depletion causes a marked irritability of the nervous system, eventually resulting in epileptic seizures. Although magnesium deficiency as a cause of epilepsy is uncommon, its recognition and correction may prove life-saving. Two case reports are presented which emphasize the importance of recognizing hypomagnesaemia in patients with acute intractable seizures.

Adult↗
PubMed1991

Comparative diffusion study of two nitrosoureas: carmustine and fotemustine in normal rat brain, human and rat brain biopsies.

In order to assess the apparent diffusion coefficient of two nitrosoureas (carmustine and fotemustine) in the brain, a model of planar diffusion was used in the rat brain and in rat and human brain biopsies. Drugs were deposed on the brain surface at a constant concentration for 30 min. At the end of the diffusion time, the concentration gradient was determined with microelectrodes using voltammetry at 5 different depths in the extracellular space of the gray matter (0-304 microns). Voltammetry with microelectrodes measured quantitatively intact drug in the brain extracellular space (CV 4% for the 2 drugs) in the range studied. The same procedure was used for human and rat brain biopsies which were held in a small cup. The apparent diffusion coefficients in living animals were 0.49 x 10(-6) cm2.s-1 for carmustine and 0.23 x 10(-6) cm2.s-1 for fotemustine; in human biopsies, they were 0.84 x 10(-6) cm2.s-1 for carmustine and 0.37 x 10(-6) cm2.s-1 for fotemustine. Significant differences in the apparent diffusion coefficients of the drugs were accounted for by the fact that the intracellular penetration of fotemustine was better than that of carmustine.

Adult↗
PubMed1990

Gastrointestinal decontamination for acute poisoning.

Acute poisoning remains a common cause of morbidity and even mortality in children and adults. The goal of gastrointestinal decontamination is to eliminate or to reduce the potentially life-threatening effects of the ingested poison. Methods of gastrointestinal detoxication in case of acute poisoning, such as induced emesis, gastric lavage, administration of activated charcoal and intestinal cleansing are discussed. As far as induced emesis is still concerned, only the administration of Ipecac-syrup can be retained. The controversy between emesis and gastric lavage still remains. For those toxins well adsorbed by activated charcoal, the administration of activated charcoal, followed or not by gastric lavage, is the treatment of choice. Single doses of activated charcoal can be insufficient. In certain kinds of poisoning, repeated doses of activated charcoal are advisable because of the interruption of the entero-hepatic and entero-enteric circulation. The benefit and the indications for intestinal cleansing in case of acute poisoning seem to be very limited.

Cathartics↗
PubMed1979

A bone-fixing trephine for large-diameter iliac biopsies in dogs.

For experimental studies of bone in dogs it may be necessary to collect from the iliac crest biopsies of a larger diameter than is usually obtainable. A disadvantage of using a trephine with a large bore is that the biopsy may be pulled out of the trephine by the forces exerted by tendons inserted in the medial cortex of the ilium. To overcome this difficulty we developed a trephine with an internal bore of 10 mm combined with a biopsy-fixing attachment.

Animals↗