1326
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Zarnstorff MC, Bell MG, Bitter M, Goldston RJ, Grek B, Hawryluk RJ, Hill K, Johnson D, McCune D, Park H, Ramsey A, Taylor G, Wieland R. Bootstrap current in TFTR. PHYSICAL REVIEW LETTERS 1988; 60:1306-1309. [PMID: 10038001 DOI: 10.1103/physrevlett.60.1306] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1327
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Abstract
It has been proposed that mucoadhesives which adhere to the gastric mucus layer may be used to prolong gastric retention time of oral dosage forms. Preliminary studies, using acrylic hydrogels, have established that the density of carboxyl groups on the polymer chain is important for mucoadhesion. To understand the role(s) of the carboxyl groups in mucoadhesion, acrylic acid-acrylamide random copolymers [P(AA-co-AM)] were synthesized, and the adhesion strength of the cross-linked polymers to the gastric mucus layer was examined as a function of the pH, initial concentration of the cross-linking agent, degree of swelling, and carboxyl-group density. From the study on mucoadhesion of various P(AA-co-AM), it was found that at least 80% of the vinyl groups of the polymer must possess carboxyl groups in the protonated form. The dependence of mucoadhesion on pH and carboxyl-group density suggests that mucoadhesion occurs through hydrogen bonding. In addition, the density of the cross-linking agent significantly affects mucoadhesion. As the density of the cross-linking agent is lowered, the mucoadhesive strength increases, although the density of carboxyl groups in the test surface area is reduced. It is concluded that for mucoadhesion to occur, polymers must have functional groups that are able to form hydrogen bonds above the critical concentration (80% for vinyl polymers), and the polymer chains should be flexible enough to form as many hydrogen bonds as possible.
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1328
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Li L, Lipert RJ, Park H, Chupka WA, Colson SD. Dynamics and spectroscopic manifestations of two‐photon bound–bound absorption through a repulsive intermediate state. J Chem Phys 1987. [DOI: 10.1063/1.453416] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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1329
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Ono M, Greene GJ, Darrow D, Forest C, Park H, Stix TH. Steady-state tokamak discharge via dc helicity injection. PHYSICAL REVIEW LETTERS 1987; 59:2165-2168. [PMID: 10035441 DOI: 10.1103/physrevlett.59.2165] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1330
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Park H, Kephart JO, Klein RK, Pantell RH, Berman BL, Datz S. Channeling radiation from GaAs. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 36:1259-1261. [PMID: 9942936 DOI: 10.1103/physrevb.36.1259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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1331
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Strachan JD, Bitter M, Ramsey AT, Zarnstorff MC, Arunasalam V, Bell MG, Bretz NL, Budny R, Bush CE, Davis SL, Dylla HF, Efthimion PC, Fonck RJ, Fredrickson E, Furth HP, Goldston RJ, Grisham LR, Grek B, Hawryluk RJ, Heidbrink WW, Hendel HW, Hill KW, Hsuan H, Jaehnig KP, Jassby DL, Jobes F, Johnson DW, Johnson LC, Kaita R, Kampershroer J, Knize RJ, Kozub T, LeBlanc B, Levinton F, Manos DM, Mansfield DK, McGuire K, McNeill DH, Meade DM, Medley SS, Morris W, Mueller D, Nieschmidt EB, Owens DK, Park H, Schivell J, Schilling G, Schmidt GL, Scott SD, Sesnic S, Sinnis JC, Stauffer FJ, Stratton BC, Tait GD, Taylor G, Towner HH, Ulrickson M, Wieland R, Williams MD, Wong KL, Yoshikawa S, Young KM. High-temperature plasmas in a tokamak fusion test reactor. PHYSICAL REVIEW LETTERS 1987; 58:1004-1007. [PMID: 10034307 DOI: 10.1103/physrevlett.58.1004] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1332
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Park H, Kephart JO, Klein RK, Pantell RH, Hynes MV, Berman BL, Dahling BA, Datz S, Swent RL, Alguard MJ. Temperature dependence of planar channeling radiation. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 35:13-17. [PMID: 9940564 DOI: 10.1103/physrevb.35.13] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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1333
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Levy RJ, Haidar M, Park H, Tar L, Levinson AI. Bacterial peptidoglycan induces in vitro rheumatoid factor production by lymphocytes of healthy subjects. Clin Exp Immunol 1986; 64:311-7. [PMID: 3488857 PMCID: PMC1542358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The present studies were carried out to further characterize the polyclonal B cell activating properties of bacterial peptidoglycan (PG) and to determine if this ubiquitous agent induces in vitro IgM rheumatoid factor (RF) production by lymphocytes from healthy volunteers. Peripheral blood mononuclear cells (PBMC) were cultured in the presence of peptidoglycan, pokeweed mitogen (PWM), a standard polyclonal B cell activator, or additional culture medium. Supernatants were harvested on days 7-8 for determination of total IgM, total IgG, and IgM RF by an enzyme-linked immunosorbent assay (ELISA). PG and PWM induced comparable amounts of total IgM production but PG was a less potent stimulant of total IgG production. PG induced in vitro IgM-RF production in 9/33 experiments, a frequency of response of less than that observed in corresponding PWM stimulated cultures (22/33 experiments). PG-induced IgM-RF production depended upon active protein synthesis and did not correlate with the magnitude of PG-induced total IgM production. The latter finding suggests that PG-induced IgM-RF may not merely reflect polyclonal B cell activation. These results add to a growing list of PG's functional properties and provide further impetus for considering this ubiquitous agent as a potential stimulant for in vivo RF production.
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1334
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Wong KL, Bitter M, Hammett GW, Heidbrink W, Hendel H, Kaita R, Scott S, Strachan JD, Tait G, Bell MG, Budny R, Bush C, Chan A, Coonrod J, Efthimion PC, England AC, Eubank HP, Fredrickson E, Furth HP, Goldston RJ, Grek B, Grisham L, Hawryluk RJ, Hill KW, Johnson D, Kamperschroer J, Kugel H, Ma C, Mansfield D, Manos D, McCune DC, McGuire K, Medley SS, Mueller D, Nieschmidt E, Owens DK, Paré VK, Park H, Ramsey A, Rasmussen D, Roquemore AL, Schivell J, Sesnic S, Taylor G, Williams MD, Zarnstorff MC. Acceleration of beam ions during major-radius compression in the tokamak fusion test reactor. PHYSICAL REVIEW LETTERS 1985; 55:2587-2590. [PMID: 10032185 DOI: 10.1103/physrevlett.55.2587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1335
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Goree J, Ono M, Colestock P, Horton R, McNeill D, Park H. Fast-wave current drive in a toroidal plasma. PHYSICAL REVIEW LETTERS 1985; 55:1669-1672. [PMID: 10031888 DOI: 10.1103/physrevlett.55.1669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1336
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Piestrup MA, Kephart JO, Park H, Klein RK, Pantell RH, Ebert PJ, Moran MJ, Dahling BA, Berman BL. Measurement of transition radiation from medium-energy electrons. PHYSICAL REVIEW. A, GENERAL PHYSICS 1985; 32:917-927. [PMID: 9896144 DOI: 10.1103/physreva.32.917] [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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1337
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Bartlett JC, Park H, Moe R. Hepatic toxicity associated with trimethoprim-sulfamethoxazole: report of a case. THE JOURNAL OF THE AMERICAN OSTEOPATHIC ASSOCIATION 1985; 85:381-2. [PMID: 3877712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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1338
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Ch'ng HS, Park H, Kelly P, Robinson JR. Bioadhesive polymers as platforms for oral controlled drug delivery II: synthesis and evaluation of some swelling, water-insoluble bioadhesive polymers. J Pharm Sci 1985; 74:399-405. [PMID: 3998999 DOI: 10.1002/jps.2600740407] [Citation(s) in RCA: 263] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A series of cross-linked, swellable polymers was sythesized from monomers such as acrylic acid, methacrylic acid, and others with various cross-linking agents to produce a range of polymers differing in charge densities and hydrophobicity. The densities, rate, and extent of hydration of the polymers were determined. An increase in the number of hydrophobic groups in the polymer structure reduced hydration whereas the density of the polymer was unaffected. A sensitive in vitro method for measuring adhesion of polymer to tissue from the rabbit stomach was developed. Polymers of acrylic acid loosely cross-linked (0.3%, w/w) with three different agents, divinyl glycol, 2,5-dimethyl-1,5-hexadiene, and divinylbenzene, showed the same degree of bioadhesion while poly(methacrylic acid-divinylbenzene) showed reduced bioadhesion. The small percent of cross-linking agent, irrespective of physicochemical properties, did not contribute substantially to bioadhesion, whereas the starting monomer had a large effect. The effect of pH on the bioadhesion of poly(acrylic acid-divinyl glycol) was studied at constant temperature, ionic strength, and osmolality. The polymer showed maximum adhesion at pH 5 and 6 and a minimum at pH 7. Gastrointestinal transit studies of cross-linked polymers in rats were studied. Poly(acrylic acid-divinyl glycol) and poly(methacrylic acid-divinylbenzene) were shown to have substantially longer GI transit times than the control, Amberlite 200 resin beads. The delay in transit time was due to bioadhesion of the polymer to the mucin-epithelial cell surface which was clearly observable on animal autopsy. The acrylic acid polymer showed a longer GI transit time than the methacrylic acid polymer, and this in vivo GI transit result is consistent with in vitro bioadhesion test results.
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1339
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Ebert PJ, Moran MJ, Dahling BA, Berman BL, Piestrup MA, Kephart JO, Park H, Klein RK, Pantell RH. Transition x rays from medium-energy electrons. PHYSICAL REVIEW LETTERS 1985; 54:893-896. [PMID: 10031648 DOI: 10.1103/physrevlett.54.893] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1340
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Klein RK, Kephart JO, Pantell RH, Park H, Berman BL, Swent RL, Datz S, Fearick RW. Electron channeling radiation from diamond. PHYSICAL REVIEW. B, CONDENSED MATTER 1985; 31:68-92. [PMID: 9935399 DOI: 10.1103/physrevb.31.68] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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1341
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Park H, Schumacher HR, Zeiger AR, Rosenbaum JT. Antibodies to peptidoglycan in patients with spondylarthritis: a clue to disease aetiology? Ann Rheum Dis 1984; 43:725-8. [PMID: 6497464 PMCID: PMC1001516 DOI: 10.1136/ard.43.5.725] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Although the aetiology of the spondylarthritic diseases, ankylosing spondylitis and Reiter's syndrome, is obscure, a clue to the pathogenesis might be an animal model, adjuvant arthritis. Rats with this disease develop a spectrum of pathology with marked similarity to the spondylarthritides. Since peptidoglycan, a major cell wall component of most bacteria is causally implicated in adjuvant arthritis, we sought evidence that peptidoglycan exposure accompanies both Reiter's syndrome and ankylosing spondylitis. Antibodies to the D-Ala-D-Ala moiety of peptidoglycan were measured by a sensitive and specific ELISA. Antibodies were elevated significantly in patients with ankylosing spondylitis or Reiter's syndrome, but not in patients with rheumatoid arthritis or degenerative joint disease in comparison with normal controls. The findings should be considered preliminary, since only a minority of patients had increased antibody titres. However, the findings are compatible with the hypothesis that peptidoglycan is causally related to spondylarthritis. Antibodies to other moieties in the peptidoglycan molecule might be a more sensitive test for significant exposure.
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1342
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Schaffer JP, Park H, Lind JH, Jones PL. Hydrogenated Amorphous Boron: Transient and Steady State Photoconductivity. ACTA ACUST UNITED AC 1984. [DOI: 10.1002/pssa.2210810159] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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1343
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Park H, Zeiger AR, Schumacher HR. Detection of soluble peptidoglycan in urine after penicillin administration. Infect Immun 1984; 43:139-42. [PMID: 6690400 PMCID: PMC263400 DOI: 10.1128/iai.43.1.139-142.1984] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
A unique enzyme-linked immunosorbent assay was developed to detect soluble peptidoglycans in biological fluids. It makes use of the similar affinities of vancomycin and purified rabbit antibodies to peptidoglycan precursor sequences found in soluble peptidoglycans. This assay has been used to detect as little as 500 pg of soluble peptidoglycan per ml of serum and 5 pg/ml of urine. Studies of normal individuals and Staphylococcus aureus-infected patients revealed only a few sera with detectable levels of soluble peptidoglycans. Studies of normal volunteers who were given a single oral dose of 250 mg of penicillin VK showed that about half had detectable levels of soluble peptidoglycans in their urine up to 6 h after ingestion. This suggests that soluble peptidoglycans can be released by indigenous bacteria in detectable amounts. In one volunteer, a detectable level of soluble peptidoglycan in the urine at 6 h decreased to an undetectable level at 12 h. Such an ephemeral appearance of soluble peptidoglycan in the urine could account for the small number of human sera that had detectable levels of soluble peptidoglycan.
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1344
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Park H. Why don't women attend for antenatal care? Is that all...? MIDWIVES CHRONICLE 1982; 95:365-6. [PMID: 6923133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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1345
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Lee P, Luhmann NC, Park H, Peebles WA, Taylor RJ, Yu CX. Far-infrared laser scattering studies of density fluctuations in tokamak fusion plasmas. APPLIED OPTICS 1982; 21:1738-1744. [PMID: 20389932 DOI: 10.1364/ao.21.001738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Development of a far-infrared Thomson scattering system for the study of density fluctuations in fusion plasmas is described. New data are presented of naturally occurring low-frequency microturbulence and also of electrostatic modes generated at the ion cyclotron range of frequencies (ICRF). The latter studies are important in understanding ICRF supplementary heating experiments. They have produced the first internal observation of mode-converted ion -Bernstein waves in a tokamak plasma.
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1346
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Park H. A simple washing technique for solid-phase radioimmunoassays and enzyme-linked immunosorbent assays. J Clin Pathol 1981; 34:1309-10. [PMID: 7033300 PMCID: PMC494500 DOI: 10.1136/jcp.34.11.1309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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1347
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Park H, Chodorow M, Kompfner R. High resolution optical ranging system. APPLIED OPTICS 1981; 20:2389-2394. [PMID: 20332965 DOI: 10.1364/ao.20.002389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An optical ranging system which can see through opaque material has been demonstrated. It uses picosecond pulses, generated in a mode-locked dye laser for viewing and, as a very fast gate, a second frequency offset pulse train with a variable delay at the detector. The system could detect a reflection from a mirror inside an opaque mixture with 64-dB round-trip loss and with 1.7-mm range resolution. Transverse resolution of 0.1 mm was also observed. With certain obvious changes in instrumentation this could be converted into a scanning device. The present depth of penetration (round-trip attenuation) would correspond to 0.67 cm in human tissue.
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1348
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Zalph BL, Dimmey LJ, Park H, Jones PL, Cocks FH. Hydrogenated amorphous boron: Resistivity and doping behavior. ACTA ACUST UNITED AC 1980. [DOI: 10.1002/pssa.2210620264] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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1349
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Chern CJ, Tan P, Park H. Chromosomal mapping of human creatine kinase (brain type) using human-rodent somatic cell hybrids. CYTOGENETICS AND CELL GENETICS 1980; 27:232-7. [PMID: 6934066 DOI: 10.1159/000131491] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Concordant segregation of human brain-type creatine kinase, CK(BB), expression with nucleoside phosphorylase (NP) expression and the presence of chromosome 14 was observed in 53 independently derived cell hybrids between CK(BB)-positive human cells and CK(BB)-negative rodent cells. Further analysis of 26 subclones of two CK(BB)-positive human-mouse cell hybrids confirmed the positive correlation of CK(BB) expression with NP expression. The results suggest that the gene coding for human CK(BB) can be assigned to chromosome 14.
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1350
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Abstract
Abstract
I describe a new technique for improving the sensitivity of the solid-phase "sandwich" assay, by using the through-passage receptacle in a novel flow-communication device. The technique allows a large volume of serum to flow through the antibody-coated receptacle repeatedly during the incubation and is thus termed the "flow-through large-volume incubation" method. Binding of 125I-labeled hepatitis B surface antigen to its corresponding antibody on a solid-phase by this method was more rapid and persistent than binding by the conventional method. When the method was applied to the first incubation of the sandwich assay, the test for the antigen was rendered four-, eight-, and 32-fold as sensitive as an accepted third-generation test for the antigen, by incubating 5-mL volumes of serum at (a) room temperature for 18 h, (b) 45 degrees C for 8 h, or (c) room temperature for seven days, respectively.
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