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Simmons RM, Finer JT, Warrick HM, Kralik B, Chu S, Spudich JA. Force on single actin filaments in a motility assay measured with an optical trap. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1993; 332:331-6; discussion 336-7. [PMID: 8109348 DOI: 10.1007/978-1-4615-2872-2_32] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have used an optical trap to measure or exert a force on single actin filaments via the attachment of polystyrene beads which were coated with NEM-modified HMM. In the simplest experiment, beads were attached to rhodamine phalloidin labelled actin filaments and observed to move on an HMM coated surface in the presence of ATP. Moving beads were steered into the vicinity of the trap using a PZT operated microscope stage. The minimum force needed to stop a moving bead was measured by lowering the trap strength until the bead resumed movement. By aligning the optical trap with the centre of a quadrant detector placed in an image plane of the microscope, it was possible to measure the force exerted on a filament by measuring the displacement of the bead position from the centre of the trap. In each of these experiments, the trap was calibrated by applying a Stokes force to a bead in free solution. The characteristics of the trap were studied, and the displacement of the bead from the centre of the trap was shown to be directly proportional to the applied force over a large part of the total range of the trap. The compliance of the trap could be substantially reduced by the use of feedback control to deflect the laser beam via an acousto-optic modulator. The advantages and limitations of this technique will be discussed.
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Dasch JR, Pace DR, Avis PD, Bentz H, Chu S. Characterization of monoclonal antibodies recognizing bovine bone osteoglycin. Connect Tissue Res 1993; 30:11-21. [PMID: 7512011 DOI: 10.3109/03008209309032927] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Six monoclonal antibodies (mAb) are described that bound to the bovine bone glycoprotein, osteoglycin. The protein osteoglycin was originally called Osteoinductive Factor (OIF). The antibodies were characterized with respect to their reaction patterns in Western blots, indirect immunoprecipitation, and binding epitope. The antibodies bound to one of two sequential determinants, either residues 62-76 or 95-105, in the C-terminal region of mature osteoglycin. One mAb, 2C11, was found to be useful for affinity purification of osteoglycin. Another mAb, 3B2, was able to immunohistochemically stain osteoblasts, osteocytes, chondrocytes, occasional osteoclasts and nail bed epithelial cells in rat neonatal forelimb. The mAbs will provide an essential tool for the further characterization of this unique glycoprotein.
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Warrick HM, Simmons RM, Finer JT, Uyeda TQ, Chu S, Spudich JA. In vitro methods for measuring force and velocity of the actin-myosin interaction using purified proteins. Methods Cell Biol 1993; 39:1-21. [PMID: 8246790 DOI: 10.1016/s0091-679x(08)60158-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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229
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Kasevich M, Chu S. Laser cooling below a photon recoil with three-level atoms. PHYSICAL REVIEW LETTERS 1992; 69:1741-1744. [PMID: 10046302 DOI: 10.1103/physrevlett.69.1741] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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230
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Kasevich M, Chu S. Measurement of the gravitational acceleration of an atom with a light-pulse atom interferometer. ACTA ACUST UNITED AC 1992. [DOI: 10.1007/bf00325375] [Citation(s) in RCA: 255] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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231
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Gibble KE, Kasapi S, Chu S. Improved magneto-optic trapping in a vapor cell. OPTICS LETTERS 1992; 17:526-528. [PMID: 19794547 DOI: 10.1364/ol.17.000526] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have captured 3.6 x 10(10) cesium atoms in a magneto-optic trap loaded from a vapor cell. The 300-fold increase in the number of trapped atoms compared with that of previous research was accomplished by using larger laser intensities and 4-cm-diameter laser beams. The loading time constant was as short as 0.2 s.
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Fee MS, Danzmann K, Chu S. Optical heterodyne measurement of pulsed lasers: Toward high-precision pulsed spectroscopy. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 45:4911-4924. [PMID: 9907574 DOI: 10.1103/physreva.45.4911] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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233
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Chu S, Park Y, Locke C, Wilson DS, Cavanaugh JC. Drug-food interaction potential of clarithromycin, a new macrolide antimicrobial. J Clin Pharmacol 1992; 32:32-6. [PMID: 1531484 DOI: 10.1002/j.1552-4604.1992.tb03784.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To evaluate the effect of food on bioavailability, clarithromycin and 14-hydroxyclarithromycin (active metabolite) pharmacokinetics were assessed in 26 healthy adult volunteers after ingestion of a single oral 500-mg dose of clarithromycin in a fasting state (2 hours before breakfast after an overnight fast) and a nonfasting state (0.5 hours after the start of breakfast). Clarithromycin and 14-hydroxy metabolite plasma concentrations were measured using a high-performance liquid chromatographic technique. Food intake immediately before dosing increased the extent of absorption from the 500-mg tablet formulation by approximately 25%. The mean increase in metabolite area under the plasma concentration-time curve was approximately 9%. These results suggest that clarithromycin can be taken without regard to timing in relation to meals.
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Moler K, Weiss DS, Kasevich M, Chu S. Theoretical analysis of velocity-selective Raman transitions. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 45:342-348. [PMID: 9906732 DOI: 10.1103/physreva.45.342] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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235
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Keefe J, Wauk L, Chu S, DeLustro F. Clinical use of injectable bovine collagen: a decade of experience. CLINICAL MATERIALS 1991; 9:155-62. [PMID: 10171198 DOI: 10.1016/0267-6605(92)90095-b] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Bovine collagen has long been recognized as a safe, highly biocompatible material. In 1981 and 1985, two injectable fibrillar suspensions of purified bovine dermal collagen, Zyderm and Zyplast collagen implant, were commercially launched in the USA for use in soft tissue contour irregularities. Since that time more than 750 000 patients have been treated with Zyderm and/or Zyplast collagen implants internationally. Adverse reactions to bovine collagen implants occur in a small percentage of treated patients. The most prevalent adverse reaction is localized hypersensitivity at treatment sites, occurring in 3% of skin tested patients and 1 to 2% of the treated patients. These reactions resolve with time as the implant material is resorbed by the host. Circulating antibodies to bovine collagen can be demonstrated in the sera of a majority of patients (90-100%) with local hypersensitivity. These antibodies are specific for bovine collagen and do not cross react with human type I, II or III collagen. Although the presence of a humoral immune response to bovine collagen can be associated with localized symptoms of hypersensitivity, antibodies to bovine collagen can also be demonstrated in the absence of any clinical manifestation.
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Chu S, Cavaignac S, Feutrier J, Phipps BM, Kostrzynska M, Kay WW, Trust TJ. Structure of the tetragonal surface virulence array protein and gene of Aeromonas salmonicida. J Biol Chem 1991; 266:15258-65. [PMID: 1869553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The paracrystalline surface protein array of the pathogenic bacterium Aeromonas salmonicida is a primary virulence factor with novel binding capabilities. The species-specific structural gene (vapA) for this array protein (A-protein) was cloned into lambda gt11 but was unstable when expressed in Escherichia coli, undergoing an 816-base pair deletion due to a 21-base pair direct repeat within the gene. However, the gene was stable in cosmid pLA2917 as long as expression was poor. A-protein was located in the cytoplasmic, inner membrane and periplasmic fractions in E. coli. The DNA sequence revealed a 1,506-base pair open reading frame encoding a protein consisting of a 21-amino acid signal peptide, and a 481-residue 50,778 molecular weight protein containing considerable secondary structure. When assembled into a paracrystalline protein array on Aeromonas the cell surface A-protein was totally refractile to cleavage by trypsin, but became trypsin sensitive when disassembled. Trypsin cleavage of the isolated protein provided evidence that both the NH2- and COOH-terminal regions form distinct structural domains, consistent with three-dimensional ultrastructural evidence. The NH2-terminal 274-residue domain remained refractile to trypsin activity. This segment connects by a trypsin and CNBr-sensitive 78-residue linker region to a COOH-terminal 129-residue fragment which could apparently refold into a partially trypsin-resistant structure after cleavage at residue 323.
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237
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Kasevich M, Chu S. Atomic interferometry using stimulated Raman transitions. PHYSICAL REVIEW LETTERS 1991; 67:181-184. [PMID: 10044515 DOI: 10.1103/physrevlett.67.181] [Citation(s) in RCA: 257] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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238
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Fee MS, Mills AP, Shaw ED, Chichester RJ, Zuckerman DM, Chu S, Danzmann K. Sensitive detection of Doppler-free two-photon-excited 2S positronium by spatially separated photoionization. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1991; 44:R5-R8. [PMID: 9905741 DOI: 10.1103/physreva.44.r5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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239
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Kasevich M, Weiss DS, Riis E, Moler K, Kasapi S, Chu S. Atomic velocity selection using stimulated Raman transitions. PHYSICAL REVIEW LETTERS 1991; 66:2297-2300. [PMID: 10043449 DOI: 10.1103/physrevlett.66.2297] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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240
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Kasevich MA, Weiss DS, Chu S. Normal-incidence reflection of slow atoms from an optical evanescent wave. OPTICS LETTERS 1990; 15:607. [PMID: 19768022 DOI: 10.1364/ol.15.000607] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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241
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Riis E, Weiss DS, Moler KA, Chu S. Atom funnel for the production of a slow, high-density atomic beam. PHYSICAL REVIEW LETTERS 1990; 64:1658-1661. [PMID: 10041454 DOI: 10.1103/physrevlett.64.1658] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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242
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Schmid-Schönbein GW, Delano FA, Chu S, Zweifach BW. Wall structure of arteries and arterioles feeding the spinotrapezius muscle of normotensive and spontaneously hypertensive rats. INTERNATIONAL JOURNAL OF MICROCIRCULATION, CLINICAL AND EXPERIMENTAL 1990; 9:47-66. [PMID: 2323897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Vessel wall structure in feed arteries and their hierarchical ramifications were investigated in a rat skeletal muscle. Emphasis was placed on the transition of wall structure elements from the axillary and thoracodorsal arteries to the feeder arteries and the arcade and transverse arterioles forming the microcirculation of the spinotrapezius muscle. Semi-thin sections, prepared for light microscopy, and ultra-thin sections for electron microscopy were used to compare mature (15-20 week old) normotensive and hypertensive animals. The results demonstrate a gradual transition of the elastica intima and the smooth muscle from the central arteries towards the arterioles, accompanied by an attenuation of the adventitia. The elastica intima in 60-40 microns arcade arterioles is reduced from a continuous sheet in the central arteries to single fibers oriented parallel to the vessel axis. The multiple layers of smooth muscle cells at the level of the feeder arteries are reduced in the majority of arcade arterioles and in transverse arterioles to a single smooth muscle coat. Comparisons of the smooth muscle mass per unit length of vessel at selected sites of normotensive and spontaneously hypertensive rats show evidence for some degree of wall hypertrophy in the axillary artery, but no evidence for wall hypertrophy in arterioles of the microcirculation. There is no evidence of a pressure-mediated structural medial wall hypertrophy along this peripheral vascular pathway.
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Kasevich MA, Riis E, Chu S, DeVoe RG. rf spectroscopy in an atomic fountain. PHYSICAL REVIEW LETTERS 1989; 63:612-615. [PMID: 10041127 DOI: 10.1103/physrevlett.63.612] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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244
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Danzmann K, Fee MS, Chu S. Doppler-free laser spectroscopy of positronium and muonium: Reanalysis of the 1S-2S measurements. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 39:6072-6073. [PMID: 9901204 DOI: 10.1103/physreva.39.6072] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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245
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Shevy Y, Weiss DS, Ungar PJ, Chu S. Bimodal speed distributions in laser-cooled atoms. PHYSICAL REVIEW LETTERS 1989; 62:1118-1121. [PMID: 10039581 DOI: 10.1103/physrevlett.62.1118] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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246
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Prentiss M, Cable A, Bjorkholm JE, Chu S, Raab EL, Pritchard DE. Atomic-density-dependent losses in an optical trap. OPTICS LETTERS 1988; 13:452-454. [PMID: 19745929 DOI: 10.1364/ol.13.000452] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have observed that two-body collisions between cold sodium atoms confined within a magnetic-molasses optical trap lead to significant atomic-density-dependent trap losses. Such losses set an upper limit to the product of atomic density and confinement time that can be achieved in such a trap.
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Chu S, Mills AP, Yodh AG, Nagamine K, Miyake Y, Kuga T. Laser excitation of the muonium 1S-2S transition. PHYSICAL REVIEW LETTERS 1988; 60:101-104. [PMID: 10038209 DOI: 10.1103/physrevlett.60.101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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248
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Raab EL, Prentiss M, Cable A, Chu S, Pritchard DE. Trapping of neutral sodium atoms with radiation pressure. PHYSICAL REVIEW LETTERS 1987; 59:2631-2634. [PMID: 10035608 DOI: 10.1103/physrevlett.59.2631] [Citation(s) in RCA: 268] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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249
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Stegman SJ, Chu S, Bensch K, Armstrong R. A light and electron microscopic evaluation of Zyderm collagen and Zyplast implants in aging human facial skin. A pilot study. ARCHIVES OF DERMATOLOGY 1987; 123:1644-9. [PMID: 3120651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Four patients received Zyderm collagen implant (ZCI) or Zyplast implant (ZI) in preauricular and infraauricular regions of facial skin periodically between one and nine months. Both materials were identified microscopically in the mid- to deep dermis at all points of the study and, in 60% to 70% of the injected sites, some material was also present subdermally. A slow, gradual colonization of ZCI by fibroblasts was noted compared with a delayed intense interaction of these cells with ZI. Also, there was some new collagen deposition associated with remodeling of the ZI, while no demonstrable synthetic activity occurred in relationship to ZCI. The results suggest that ZCI and ZI "migrate" deeper and eventually move into the subcutaneous plane. This movement could explain the loss of correction at six to nine months that is noted when this implant is used for age-related changes.
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250
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Chu S, Bjorkholm JE, Ashkin A, Cable A. Experimental observation of optically trapped atoms. PHYSICAL REVIEW LETTERS 1986; 57:314-317. [PMID: 10034028 DOI: 10.1103/physrevlett.57.314] [Citation(s) in RCA: 179] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
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