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Biomedical subjects

A Trouet

Publications and source records attributed to A Trouet.

At least 145 records · Page 8Linked to original sources
PubMed1974

Analytical fractionation of homogenates from cultured rat embryo fibroblasts.

Homogenates of cultured rat embryo fibroblasts have been assayed for acid phosphatase, N-acetyl-beta-glucosaminidase, cathepsin D, acid deoxyribonuclease, cytochrome oxidase, NADH cytochrome c reductase, 5'-nucleotidase, inosine diphosphatase, acid pyrophosphatase, neutral pyrophosphatase, esterase, catalase, cholesterol, and RNA. The validity of the assay conditions was checked. Neutral pyrophosphatase is a readily soluble enzyme. Acid hydrolases, except acid pyrophosphatase, are particle-bound enzymes, which exhibit a high degree of structural latency. They are activated and solubilized in a parallel fashion by mechanical treatments and tensio-active agents. Catalase is also particle-bound and latent; activating conditions stronger than those for hydrolases are required to activate the enzyme. Acid pyrophosphatase, 5'-nucleotidase and inosine diphosphatase are firmly particle-bound, but not latent; they are not easily solubilized. In differential and isopycnic centrifugation, the latent hydrolases, cytochrome oxidase and catalase dissociate largely from each other; this suggests the occurrence of lysosomes and peroxisome-like structures besides mitochondria. The distribution patterns of 5'-nucleotidase and cholesterol are largely similar; digitonin influences their equilibrium density to the same extent; these two constituents are thought to be related to the plasma membrane. Inosine diphosphatase and acid pyrophosphatase are also partially associated with the plasma membrane, although some part of these enzymic activities probably belongs to other structures. NADH cytochrome c reductase is associated partly with the endoplasmic reticulum, partly with mitochondria.

Acid Phosphatase↗
PubMedDate not supplied

Immunological evaluation of blood contamination in tissue distribution studies.

An original, simple and economical method allowing the evaluation of blood contamination in tissue distribution studies is described. This method is based on the immunochemical determination of the amount of serum albumin present in tissue samples as a quantitative measurement of blood contamination, using a single radial immunodiffusion technique according to Mancina et al. Two pharmacokinetic studies we have performed in mice for different research purposes illustrate the crucial importance of the correction for blood contamination in the exact interpretation of the tissue uptake of a given compound. We have indeed clearly demonstrated first in the development of drug-carrier complexes in targeted cancer chemotherapy and second in the study of receptor-mediated clearance of glycoproteins from the plasma that the blood contamination, if not taken into account, can greatly alter the data of uptake by target organs. Our method is thus particularly useful in in vivo pharmacokinetic studies and is moreover not restricted to one animal species.

Animals↗
PubMedDate not supplied

Smooth muscle cells influence monocyte response to LDL as well as their adhesion and transmigration in a coculture model of the arterial wall.

We investigated the possible interference of smooth muscle cells with monocyte response to LDL as well as with their adhesion and transmigration in a coculture of porcine endothelial and smooth muscle cells. Lysophosphatidylcholine (LPC), a component of oxidized LDL (oxLDL), stimulated the adhesion of THP-1 cells to endothelial cells both in mono- and in coculture with smooth muscle cells. When THP-1 cells were incubated with endothelial cells in the presence of copper oxLDL, their adhesion was increased, but only in coculture. The addition of sodium nitroprusside (SNP) together with oxLDL markedly increased the adhesion of THP-1 cells in coculture. Close proximity between endothelial and smooth muscle cells was necessary to observe that effect. Furthermore, this increase in adhesion of THP-1 cells can, at least in part, be attributed to the augmented production of monocyte chemoattractant protein-1 (MCP-1) observed in coculture under the influence of oxLDL and SNP. The passage of THP-1 cells through the coculture was stimulated by MCP-1 and LPC. These results show that physical contacts or close proximity between endothelial and smooth muscle cells play a key role in the adhesion of monocytes and their infiltration into the intima in response to oxLDL.

Animals↗
PubMedDate not supplied

Vinblastine-C4 alkyl maleoyl and amino acid maleoyl derivatives: III. Experimental antitumor activities of lactosaminated serum albumin conjugates.

Vinblastine-C4 acyl derivatives were synthesized by linking alkyl maleoyl or amino acid maleoyl compounds through an ester linkage at C4 position of the Vindoline moiety of Vinblastine. To target these derivatives selectively to hepatoma, conjugates were prepared with a neoglycoprotein i.e. lactosaminated human albumin, as a specific carrier. The method of preparation of lactosaminated albumin and of coupling to Vinca alkaloid derivatives is described and the mechanism of addition of the protein to the derivative is discussed. The experimental antitumor activity of these conjugates has been screened against the experimental P-388 Leukemia. The activity of the best conjugate has been evaluated in several human tumor xenografts. Further, the therapeutic potential of this type of conjugate has been demonstrated in a model of hepatoma xenograft developed in our laboratory, the HepG2 carcinoma.

Animals↗