The gp41 envelope protein of human immunodeficiency virus type 1 (HIV-1) contains an alpha-helical core structure responsible for mediating membrane fusion during viral entry. Recent studies suggest that a conserved hydrophobic cavity in the coiled coil of this core plays a distinctive structural role in maintaining the fusogenic conformation of the gp41 molecule. Here we investigated the impor...

OBJECTIVE In the present work we studied the expression of nerve growth associated protein (GAP-43) in a rat model of intervertebral disc degeneration. METHODS 16 healthy adult SD rats, male or female, with an average weight 220g were selected. FluoroGold was injected in L5-L6 disc as the tracer. After 7 days, Freund's adjuvant was then injected to build model of intervertebral disc degenerat...

Oleate has been shown to protect against palmitate-induced insulin resistance. The present study investigates mechanisms involved in the interaction between oleate and palmitate on insulin-stimulated glucose uptake by L6 skeletal muscle cells. L6 myotubes were cultured for 6 h with palmitate or oleate alone, and combinations of palmitate with oleate, with and without phosphatidylinositol 3-kina...

F-BAR proteins are a newly described family of proteins with unknown physiological significance. Because F-BAR proteins, including Cdc42 interacting protein-4 (CIP4), drive membrane deformation and affect endocytosis, we investigated the role of CIP4 in GLUT4 traffic by flow cytometry in GLUT4myc-expressing L6 myoblasts (L6 GLUT4myc). L6 GLUT4myc cells express CIP4a as the predominant F-BAR pro...

Ampelopsin (APL), a major bioactive constituent of Ampelopsis grossedentata, exerts a number of biological effects. Here, we explored the anti-diabetic activity of APL and elucidate the underlying mechanism of this action. In palmitate-induced insulin resistance of L6 myotubes, APL treatment markedly up- regulated phosphorylated insulin receptor substrate-1 and protein kinase B, along with a co...

1. Exposure of 7 L2-L6 neurones to hypoxia for 65 min resulted in hyperpolarization of the membrane potential (EM) from a mean of -49.1 +/- 2.1 to -54.1 +/- 3.6 mV (S.E.). 2. Intracellular potassium ion activities (aiK) increased significantly from 137.7 +/- 4.0 to 155.6 +/- 3.4 mM-K+. This is equivalent to a change in EK from -74.2 mV commensurate with the observed hyperpolarization of 5 mV. 3...

Layer 4 (L4) of primary auditory cortex (A1) receives a tonotopically organized projection from the medial geniculate nucleus of the thalamus. However, individual neurons in A1 respond to a wider range of sound frequencies than would be predicted by their thalamic input, which suggests the existence of cross-frequency intracortical networks. We used laser scanning photostimulation and uncaging ...

The monitoring of antibody-directed enzyme-prodrug therapies re quires evaluation of drug activation within the tissues of interest. We have demonstrated the feasibility of noninvasive magnetic resonance spectroscopy and spectroscopic imaging (chemical shift imaging) to detect activa tion of the prodrug 5-fluorocytosine (5-FCyt) to the cytotoxic species 5-fluorouracil (5-FU) by monoclonal antib...

1. A linear relation, with a slope of 0-9 +/- 0-2 on a log-log plot, was obtained between acetylcholine (ACh) sensitivity and alpha-bungarotoxin (alpha-BTX) binding site density in developing L6 and rat primary myotubes. ACh sensitivity was defined as g/Qn where g is conductance, Q is ACh charge and n is the Hill coefficient. Experimentally we found n approximately 1-7 for our myotubes, which i...

A method is described for measuring volume changes in single L6 myoblasts at a stage of proliferating "myoballs", which allows to follow volume changes on single cell level by means of quantitative video image analysis. Myoblasts exposed to hypoosmotic or hyperosmotic challenges for up to 3-5 min behave as osmometers. The relative cell volume is a linear function of the reciprocal of the relati...