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Biomedical subjects

J D Brailsford

Publications and source records attributed to J D Brailsford.

10 recordsLinked to original sources
PubMed1989

Red cell membrane crenation: a macromodel of the echinocyte I.

A physical macromodel of the erythrocyte membrane was constructed to investigate the effect of intrinsic membrane precurvature on a unique non-isotropic, composite material that dissipated shear energy but stored bending energy. The intrinsic precurvature of the material could be modified from strong positive precurvature through neutral to strong negative precurvature. A spherical shell constructed of the negatively precurved variant of this non-isotropic material spontaneously assumed the characteristic shape of the echinocyte I.

Erythrocyte Membrane↗
PubMed1982

Erythrocyte membrane expansion due to the volatile anesthetics, the 1-alkanols, and benzyl alcohol.

The extent to which semiturgid red cells could enter the tip of a glass micropipette of approximately 1-microgram internal diameter was used to measure the area expansion of freshly drawn erythrocytes. The pipette was mounted in a gas-tight glass observation chamber so that one single cell at a time could be observed while it was being perfused, either with buffer alone or with buffer containing an anesthetic at physiologic concentration. The effect of the drugs was studied at room temperature at doses of 1, 2, and 4 times ED50 for tadpoles. The drugs studied were: halothane, methoxyflurane, diethyl ether, fluroxene, isoflurane, hexanol, heptanol, octanol, decanol, dodecanol, tridecanol, tetradecanol, hexadecanol, and benzyl alcohol. The measured expansion closely approximated the expansion expected by incorporation of the molecules. Tetradecanol and hexadecanol are not anesthetic to tadpoles, but they did expand the membrane. Therefore, expansion may not be related to anesthesia.

Alcohols↗
PubMed1976

Red cell membrane deformability: new data.

Red cells arrested by fine fibers and subjected to drag forces in a moving stream of fluid can be stressed beyond the point of rupture. The technique, which is basically an in vitro analogue of the microangiopathic hemolytic state, thus permits a study of red cell behavior over the entire range of stress that the membrane can withstand. Measurements made by this approach show an exponential relationship between the velocity of fluid flow and the resultant membrane deformation. Such exponential membrane deformation is consistent with the morphology of red cell fragments and appears to explain their mechanism of formation.

Blood Flow Velocity↗
PubMed1975

A new method of measuring the deformability of the red cell membrane.

Red cells moving in a stream of fluid can be arrested by means of a network of fibrin threads. Those cells which fold over a fibrin thread present to view a flat strap-like portion of membrane in which the strain can be easily observed and accurately measured both optically and by scanning electron microscopy. Preliminary results obtained by this method show elastic strains of nearly 300% and indicate that the stress required to produce these large strains is an order of magnitude greater than that reported by other methods.

Blood Flow Velocity↗