An experimental method has been established to measure the electric properties of a cell membrane by combination of patch clamp and dual-wavelength ratio imaging of a fluorescent potentiometric dye, 1-(3-sulfonatopropyl)-4-[beta[2-(di-n-octylamino)-6-naphthyl]vinyl ]pyridinium betaine (di-8-ANEPPS). Pairs of fluorescence images from the dye-stained membrane of neuroblastoma N1E-115 cells excited at two wavelengths were initially obtained to calculate ratio images corresponding to the resting transmembrane potential. Subsequently, a whole-cell patch was established and the membrane potential clamped to levels varying from -100 to +60 mV; at each voltage, a pair of dual-wavelength images were acquired to develop a calibration of the fluorescence ratio. Using this method, the resting potentials could accurately be measured showing that the differentiated cells were 17 mV more polarized than undifferentiated cells. The combination of electrical and optical methods can also follow changes in other membrane electric properties, such as dipole potential, and thus permit a detailed analysis of the membrane electrical properties underlying the voltage regulation of ion channels.
Abstract:In reviewing the literature pertaining to interfacial water, colloidal stability, and cell membrane function, we are led to propose that a cascade of events that begins with acute exogenous surfactant-induced interfacial water stress can explain the etiology of sudden death syndrome (SDS), as well as many other diseases associated with modern times. A systemic lowering of serum zeta potential mediated by exogenous cationic surfactant administration is the common underlying pathophysiology. The cascade leads to subsequent inflammation, serum sickness, thrombohemorrhagic phenomena, colloidal instability, and ultimately even death. We propose that a sufficient precondition for sudden death is lowered bioavailability of certain endogenous sterol sulfates, sulfated glycolipids, and sulfated glycosaminoglycans, which are essential in maintaining biological equipose, energy metabolism, membrane function, and thermodynamic stability in living organisms. Our literature review provides the basis for the presentation of a novel hypothesis as to the origin of endogenous bio-sulfates which involves energy transduction from sunlight. Our hypothesis is amply supported by a growing body of data showing that parenteral administration of substances that lower serum zeta potential results in kosmotropic cationic and/or chaotropic anionic interfacial water stress, and the resulting cascade.Keywords: inflammation; serum sickness; colloidal instability; interfacial water stress; bio-sulfates; Shwartzman phenomena; sudden death syndrome Glossary of TermsAnaphylaxis a severe, rapidly progressing, life-threatening, generalized allergic reaction. Biological equipoise a stable, non-equilibrium, dissipative system synonymous with life. Cholesterol sulfate (Ch-S)quantitatively the most important known sterol sulfate in human plasma where it regulates the activity of the serine proteases, in cell membranes where it has a stabilizing role, and in platelet membranes where it supports platelet adhesion. Coherence domain (CD)a water CD is a collection of liquid water molecules which oscillate in unison in tune with a self-trapped electromagnetic field at a well-defined frequency. The coherent oscillations produce an ensemble of quasi-free electrons, able to collect noise energy from the environment and transform it into high-grade coherent energy in the form of electron vortices. This high-grade energy may then activate biomolecules resonating with the water CD. Colloidal instabilitya property attributed to a colloidal suspension that develops when stabilizing repulsive steric and electrostatic forces between colliding particles are insufficient to prevent their natural tendency to aggregate into masses large enough to precipitate.Colloidal suspension a colloid that has a continuous liquid phase in which a solid is suspended in a liquid, e.g., our flowing blood. Exclusion zone (EZ)a glass-like, gel phase consisting of water CDs resonating in-phase, adjacent to hydrophilic surfaces, several hundred micrometers wide which excludes colloi...
Patch-clamp recording techniques were used to examine the direct effects of mechanical stimulation on ion channel activity in human osteoblast-like osteosarcoma cells. Three classes of mechanosensitive ion channels were present and could be distinguished on the basis of conductance, ionic selectivity, and sensitivity to membrane tension. The largest conductance channel (160 pS) was K(+)-selective and showed both a decrease in long closed interval duration and an increase in burst length with increasing membrane tension. For low applied pressures, there was an e-fold increase in the probability of this channel being open (Popen) for every 3.4 cm2 Hg change in pressure. Two additional pressure-dependent channels had smaller conductances, i.e., 60 pS and 20 pS; the 60 pS channel appeared to be non-selective for cations. We propose that one or more of these mechanosensitive channels is involved in the response of bone to mechanical loading.
IMPORTANCE Guidelines for patients with atherosclerotic cardiovascular disease (ASCVD) recommend intensive statin therapy and adding nonstatin therapy if low-density lipoprotein cholesterol (LDL-C) levels are 70 mg/dL or more. Compliance with guidelines is often low.OBJECTIVE To track LDL-C treatment patterns in the US over 2 years. DESIGN, SETTING, AND PARTICIPANTS GOULD is a prospective observational registry study involving multiple centers. Patients with ASCVD receiving any lipid-lowering therapy (LLT) were eligible. Between December 2016 and July 2018, patients were enrolled in 1 of 3 cohorts: (1) those currently receiving proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) and 2 groups not receiving PCSK9i drugs, with (2) LDL-C levels of 100 mg/dL or more or (3) LDL-C levels of 70 to 99 mg/dL. Patients had medical record reviews and telephone interviews every 6 months. Analysis was done on data collected as of October 5, 2020. MAIN OUTCOMES AND MEASURESThe primary outcome was the change in LLT use in 2 years. Secondary outcomes included the number of LDL-C measurements, LDL-C levels, and responses to structured physician and patient questionnaires over 2 years.RESULTS A total of 5006 patients were enrolled (mean [SD] age, 67.8 [9.9] years; 1985 women [39.7%]; 4312 White individuals [86.1%]). At 2 years, 885 (17.1%) had LLT intensification. In the cohorts with LDL-C levels of 100 mg/dL or more and 70 to 99 mg/dL, LLT intensification occurred in 403 (22.4%) and 383 (14.4%), respectively; statins were intensified in 115 (6.4%) and 168 (6.3%), ezetimibe added in 123 (6.8%) and 118 (4.5%), and PCSK9i added in 114 (6.3%) and 58 (2.2%), respectively. In the PCSK9i cohort, 508 of 554 (91.7%) were still taking PCSK9i at 2 years. Lipid panels were measured at least once over 2 years in 3768 patients (88.5%; PCSK9i cohort, 492 [96.1%]; LDL-C levels Ն100 mg/dL or more, 1294 [85.9%]; 70-99 mg/dL, 1982 [88.6%]). Levels of LDL-C fell from medians (interquartile ranges) of 120 (108-141) mg/dL to 95 (73-118) mg/dL in the cohort with LDL-C levels of 100 mg/dL or more, 82 (75-89) to 77 (65-90) mg/dL in the cohort with LDL-C levels of 70 to 99 mg/dL, and 67 (42-104) mg/dL to 67 (42-96) mg/dL in the PCSK9i cohort. Levels of LDL-C less than 70 mg/dL at 2 years were achieved by 308 patients (21.0%) and 758 patients (33.9%) in the cohorts with LDL-C levels of 100 mg/dL or more and 70 to 99 mg/dL, respectively, and 272 patients (52.4%) in the PCSK9i cohort. At 2 years, practice characteristics were associated with more LLT intensification (teaching vs nonteaching hospitals, 148 of 589 [25.1%] vs 600 of 3607 [16.6%]; lipid protocols or none, 359 of 1612 [22.3%] vs 389 of 2584 [15.1%]; cardiology, 452 of 2087 [21.7%] vs internal or family medicine, 204 of 1745 [11.7%] and other, 92 of 364 [25.3%]; all P < .001) and achievement of LDL-C less than 70 mg/dL (teaching vs nonteaching hospitals, 173 of 488 [35.5%] vs 823 of 2986 [27.6%]; lipid protocols vs none, 451 of 1411 [32.0%] vs 545 of 2063 [26.4%]; both P < .001; cardi...
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