Single iPSC and hESC cardiomyocytes.

<p>Histograms of contraction force, beat width and beat rate of single iPSC-CM (a, top) and hESC-CM (a, bottom). Each curve in the plot is the smoothed histogram of the beats of a single cell measured at a single site on each cell. (b) Statistical analysis showing means of individual cells (dots), plus 25^th, 50^th, and 75^th percentile quantiles (box) and range of all points (whiskers). Statistical comparison by t test is shown.</p

Measurement of force of CMs.

<p>(a) The AFM cantilever is brought into gentle contact with the cardiomyocyte, placing 100 pN of pre-loaded force on it. The z-piezo is locked and the cantilever tip dwells on the top of the cardiomyocyte. (b) Shows a typical force trajectory where the green box shows indentation of the cell. The contraction of the cardiomyocyte appears as peaks in the trajectory. The height, full width at half maximum (FWHM) and reciprocal of beat-to-beat separation of peaks characterize the force, duration and frequency of cardiomyocyte beat, respectively. The fit of indentation curve by using Hertz model (red curve in (c)) produces the Young's modulus of the cell membrane at the contact point.</p

Measurement of drug effect on CMs.

<p>(a) Contraction force trajectories measured before and after treatment of iPSC- and hESC-CMs with norepinephrine. (b) Histograms of contraction force and frequency before and after treatment. (c) Beating force measured from a cluster of iPSC-CM in response to increasing doses of the adrenergic agonist epinephrine. (d) Beating force measured from a cluster of iPSC-CM in response to increasing doses of epinephrine, treated prior with the beta-blocker metoprolol.</p

AFM dwell map of dilated cardiomyopathy iPSC-CM.

<p>(<b>a</b>) Brightfield image of an iPSC-CM showing the AFM cantilever (black shadow). The yellow grid superimposed on the cell shows the range of the dwell map. (<b>b</b>) Dwell map showing contraction forces of a single iPSC-CM at various points on the grid. (<b>c</b>) Dwell map showing Young's modulus of a single iPSC-CM at various points on the grid. The periphery of the cell had higher contraction forces and elasticity compared to the central areas. (<b>d</b>) Beating force and Young's modulus (local elasticity) measurements were obtained from dwell mapping iPSC-CM derived from either a healthy subject (red) or from a subject with dilated cardiomyopathy (DCM, blue). Single points on the plot correspond to beat force and elasticity measured at each grid points of the dwell map. Points where no contraction force was measured (e.g., on the glass slide surrounding the cell) are not shown. The contour plot (middle) represents the probability distribution of dwell mapped points in the Young's modulus vs. beating force coordinate system. The contours show that beats measured from most portions of the healthy iPSC-CM fall in a region of moderate elasticity (50 – 5 kPa) and strong force (∼1 nN), whereas some points of the dwell map of DCM iPSC-CM showed comparatively lower beat forces and lower elasticity. Corresponding histograms that flank the contour plot are the distributions of beat force (above the contour plot) and elasticity (left of the contour plot), respectively.</p

AFM measurement of iPSC-CM cluster.

<p>(a) Bright field micrograph of cluster of iPSC-CMs. (b) Contraction force trajectory. The contraction of the CM cluster shows very regular beat force (c), frequency (d) and width (e).</p

Discovery of a Novel Class of Bicyclo[3.1.0]hexanylpiperazines as Noncompetitive Neuropeptide Y Y1 Antagonists

A novel class of bicyclo[3.1.0]­hexanylpiperazine neuropeptide Y (NPY) Y1 antagonists has been designed and synthesized. Scatchard binding analysis showed these compounds to be noncompetitive with [¹²⁵I]­PYY binding to the Y1 receptor. The most potent member, 1-((1α,3α,5α,6β)-6-(3-ethoxyphenyl)-3-methylbicyclo[3.1.0]­hexan-6-yl)-4-phenylpiperazine (<b>2</b>) had an IC₅₀ = 62 nM and displayed excellent oral bioavailability in rat (% <i>F</i> po = 80), as well as good brain penetration (B/P ratio = 0.61). In a spontaneous nocturnal feeding study with male Sprague–Dawley rats, <b>2</b> significantly reduced food intake during a 12 h period