Alexander A. Spector

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Polyunsaturated fatty acids (PUFAs) are critical to nervous system function and structure, but their rates of incorporation from plasma into brain have not been evaluated. In the adult rat, calculations based on our model show that at least 3;-5% of esterified brain arachidonic acid (AA) and 2;-8% of esterified brain docosahexaenoic acid (DHA) are replaced(More)
Spatial patterns of cellular growth generate mechanical stresses that help to push, fold, expand, and deform tissues into their specific forms. Genetic factors are thought to specify patterns of growth and other behaviors to drive morphogenesis. Here, we show that tissue form itself can feed back to regulate patterns of proliferation. Using(More)
Polyunsaturated fatty acids (PUFA), which comprise 25-30% of the fatty acids in the human brain, are necessary for normal brain development and function. PUFA cannot be synthesized de novo and must be supplied to the brain by the plasma. It is necessary to know the PUFA content and composition of the various plasma lipids and lipoproteins in order to(More)
Protrusions are deformations that form at the surface of living cells during biological activities such as cell migration. Using combined optical tweezers and fluorescent microscopy, we quantified the mechanical properties of protrusions in adherent human embryonic kidney cells in response to application of an external force at the cell surface. The(More)
Oxidation of LDL in the subendothelial space has been proposed to play a key role in atherosclerosis. Endothelial cells produce superoxide anions (O2.-) and oxidize LDL in vitro; however, the role of O2.- in endothelial cell-induced LDL oxidation is unclear. Incubation of human LDL (200 microg/mL) with bovine aortic endothelial cells (BAECs) for 18 hours(More)
We investigated the mechanotransduction pathway in endothelial cells between their nucleus and adhesions to the extracellular matrix. First, we measured nuclear deformations in response to alterations of cell shape as cells detach from a flat surface. We found that the nuclear deformation appeared to be in direct and immediate response to alterations of the(More)
Elongated, highly polyunsaturated derivatives of linoleic acid (18:2 omega-6) and linolenic acid (18:3 omega-3) accumulate in brain, but their sites of synthesis are not fully characterized. To investigate whether neurons themselves are capable of essential fatty acid elongation and desaturation or are dependent upon the support of other brain cells,(More)
Outer hair cell electromotility is crucial for the amplification, sharp frequency selectivity, and nonlinearities of the mammalian cochlea. Current modeling efforts based on morphological, physiological, and biophysical observations reveal transmembrane potential gradients and membrane tension as key independent variables controlling the passive and active(More)
An initial exposure to high concentrations of free fatty acid increased the transfer of albumin across cultured endothelial monolayers. The rate and amount of albumin transfer was dependent on the oleic acid concentration to which the cultures were initially exposed, with 300 microM producing the maximum transfer. The albumin transfer also increased with(More)