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E Couture

Publications and source records attributed to E Couture.

8 recordsLinked to original sources
PubMed1997

Physicochemical characterisation of mangafodipir trisodium.

PURPOSE: To determine the structure and various physicochemical properties of mangafodipir (MnDPDP) trisodium, the active ingredient of Teslascan, a new-organ-specific contrast medium for MR imaging. MATERIAL AND METHODS: The structure of MnDPDP trisodium crystals was determined by X-ray crystallography. The possible existence of polymorphism in MnDPDP trisodium was evaluated by powder X-ray diffraction, optical microscopy, thermal analysis and IR spectroscopy. In addition, various spectroscopic techniques and physicochemical measurements were used for characterisation of MnDPDP trisodium. RESULTS: The crystallographic data obtained for MnDPDP trisodium show that the general core structure of the MnDPDP anion is similar to that seen in related substances. The metal coordination geometry is a distorted octahedron defined by 2 phenolate oxygens, 2 carboxylate oxygens and 2 amine nitrogens. The unit cell contains 2 MnDPDP anions, 6 sodium ions and 50 water molecules. The various spectroscopic data are consistent with the structure determined by X-ray crystallography. The product (Teslascan) has low viscosity, is isotonic with blood and has a physiological pH. CONCLUSION: MnDPDP trisodium is a crystalline, hygroscopic solid which is readily soluble in water. No evidence of polymorphism was seen in the samples studied.

Chemical Phenomena↗
PubMed1987

Effect of 40749 RP on basal and sham feeding stimulated gastric secretion in man.

40749 RP, a pyridyl-2-tetrahydrothiophene derivative, is known to be a potent inhibitor of the gastric acid response to pentagastrin, betazole and a meal. In 6 healthy young volunteers, a single oral dose of 2 mg.kg-1 greatly reduced the gastric acid secretory response to sham-feeding. By contrast, neither gastric pepsin nor the plasma PP response were altered by the drug. No change was observed in plasma gastrin, motilin, VIP or somatostatin concentrations. The results show that 40749 RP is also active on the pure vagus-stimulated gastric acid secretion. The lack of effect upon gastric pepsin and plasma PP suggests that 40749 RP is not likely to act on the basolateral cholinergic receptor and that it affects further cellular steps involved in hydrogen ion secretion.

Adult↗
PubMed1983

Monoclonal antibodies reveal lamB antigenic determinants on both faces of the Escherichia coli outer membrane.

LamB protein is involved in the transport of maltose across the outer membrane and constitutes the receptor for phage lambda. In this study we characterized six previously described anti-LamB monoclonal antibodies (mAbs). Four of these, the E-mAbs, recognized determinants that were exposed at the cell surface, whereas the other two, the I-mAbs, recognized determinants which were not exposed. Competition experiments demonstrated that the domains recognized by these two classes of mAbs were completely distinct. In addition, the E-mAbs prevented LamB from neutralizing phage lambda in vitro and protected LamB against proteolytic degradation, whereas the I-mAbs had no such effects. The E-mAbs have been shown previously to constitute two classes: some E-mAbs inhibit maltose transport in vivo, and others do not. Immunoelectron microscopy demonstrated that the I-mAbs also define at least two types of determinants. One of these, which is accessible in membrane fragments from a mutant (lpp) devoid of lipoprotein but not in membrane fragments from an lpp+ strain, probably corresponds to a region of LamB that is involved in the interactions with peptidoglycan. The other determinant, which is fully accessible in LamB-peptidoglycan complexes and in LamB-containing phospholipid vesicles but only slightly accessible in membrane fragments from an lpp mutant, is probably located very close to the inner surface of the outer membrane. LamB also contains at least one additional determinant, which (i) is exposed at the inner surface of the membrane, (ii) is accessible to antibodies in membrane fragments from an lpp+ strain, and (iii) may be involved in the interaction of LamB with the periplasmic maltose-binding protein.

Antibodies, Monoclonal↗
PubMed1977

Studies related to the head-maturation pathway of bacteriophages T4 And T2:II. nuclear disruption, protein synthesis and particle formation with the mutant 43-.30-.46-.

We describe the aberrant phage multiplication of the triple conditional lethal mutant 43-(polymerase).30-(ligase).46-(exonuclease) of bacteriophage T4D in which phage DNA replication is arrested but some late protein synthesis occurs (33). The nuclear disruption is indistinguishable from wild type. Forty-five empty small and empty large particles are assembled per cell when the multiplicity of infection (m.o.i.) is 100. This number corresponds closely to the 38 phage equivalents of cleaved major head protein determined biochemically. By reducing the m.o.i. the number of observable particles decreases, reaching 1-5 per cell at an m.o.i. of 5(+5). The total synthesis of phage related proteins is not significantly dependant on the m.o.i. The synthesis of late proteins is about 10% of that of wild type at high m.o.i. and decreases with the m.o.i. The different early and late proteins do not show the same relative proportions as in wild type and respond differently to an increased m.o.i. These and other results are discussed with respect to the role of phage DNA in prehead assembly and head maturation.

Coliphages↗