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A Salmon

Publications and source records attributed to A Salmon.

44 records · Page 3Linked to original sources
PubMedDate not supplied

The effect of lung surfactant apolipoproteins B/C on the chemical shift anisotropy of sn-2-[1-13C]dipalmitoylphosphatidylcholine.

Nuclear magnetic resonance spectroscopy has been used to investigate the effect of the lung surfactant apolipoproteins B/C on dipalmitoylphosphatidylcholine to address the mechanism by which the adsorption rate of phospholipids from the bulk to the air/water interface is enhanced. Apolipoproteins B/C were isolated from bovine lung and separated from associated lipids by lipophilic Sephadex column chromatography. Amino acid analysis indicated the presence of both apolipoproteins B and C. The 13C chemical shift anisotropy of DPPC was determined as a function of temperature. Previous workers (Wittebort et al., Biochemistry, 20 (1981) 3487-3502) have concluded that the observed magnitude of the chemical shift anisotropy of the carbonyl group of the sn-2 acyl chain in pure DPPC is a result of rapid rotation about an axis along the length of the phospholipid both in the gel and liquid crystalline state. The orientation of the carbonyl group with respect to the axis of diffusion, however, undergoes an approximately 25-30 degrees shift in passage from the gel to liquid crystalline state, with the intermediate, rippled (P beta') state composed of an exchange between these two orientations. The presence of physiological concentrations SP-B/C reduced the width of the anisotropy of DPPC below but had no effect on lipids above the main phase transition temperature. This suggests that SP-B/C has a general effect on the entire assembly of lipids. The temperature of the onset of the orientational change is lowered indicating a portion of the lipids are affected by the lung surfactant apolipoproteins.

1,2-Dipalmitoylphosphatidylcholine↗
PubMedDate not supplied

[Thrombocytopenia: clinicobiologic validation and classification].

Thrombocytopenia occurs frequently. We will illustrate, through the presentation of a clinical case, the difficulties encountered to identify and characterize thrombocytopenia. The clinicobiological validation of a low platelet count implies, at the same time, the biologist, who must assume the validation of numeration while mentioning the morphological characteristics of the platelets and other blood cells, as well as the clinician who must interpret these data according to the clinical context. Firstly, we will detail the basic rules to correctly ensure this validation. Secondly, we will see which are the arguments which that make it possible to direct the diagnosis towards an acquired or inherited thrombocytopenia. Lastly, we will approach the classification of inherited thrombocytopenias.

Female↗