1126
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Lin H, Niu MT, Yoganathan T, Buck GA. Characterization of the rRNA-encoding genes and transcripts, and a group-I self-splicing intron in Pneumocystis carinii. Gene X 1992; 119:163-73. [PMID: 1398096 DOI: 10.1016/0378-1119(92)90268-t] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Although Pneumocystis carinii is the most common opportunistic pathogen infecting individuals with AIDS, very little is known of the basic biology of the organism. We have examined the ribosomal RNA (rRNA) and the DNA encoding it (rDNA) in P. carinii in an attempt to clarify its taxonomic position and to begin to study its genetic processes. Electrophoretic analysis showed that the sizes of the P. carinii rRNAs are quite similar to the sizes of the corresponding rRNAs from Saccharomyces cerevisiae. Direct sequence analysis of approx. 60% of the 18S small subunit-rRNA (Ss-rRNA) confirmed that its sequence is similar to that of yeast-like fungi and that a putative group-I intron previously observed in the 18S rDNA is, in fact, excised from the mature rRNA. PCR analysis of the intron in P. carinii genomic DNA showed that each of the multiple rDNA genes bears the group-I intron and in vitro transcripts of the intron autocatalytically excise from the rRNA primary transcript in the presence of GTP. Finally, analogues of GTP inhibit the self-splicing reaction, indicating that the guanosine-binding site of the intron closely resembles that of other well-characterized group-I introns. Since no group-I introns have been found in higher eukaryotes, this self-splicing process represents a viable target for chemotherapy of P. carinii pneumonia (PCP).
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MESH Headings
- Antifungal Agents/pharmacology
- Base Sequence
- Binding, Competitive
- Cloning, Molecular
- DNA, Fungal
- Guanosine/metabolism
- Introns
- Molecular Sequence Data
- Nucleic Acid Conformation
- Pneumocystis/genetics
- Polymerase Chain Reaction
- RNA Splicing
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Ribosomal/genetics
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 5.8S/genetics
- RNA, Ribosomal, 5S/genetics
- Transcription, Genetic
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1127
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Budick B, Chen J, Lin H. Bremsstrahlung from tritium beta decay. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1992; 46:1267-1275. [PMID: 9968234 DOI: 10.1103/physrevc.46.1267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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1128
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Lamy P, Kuhn JR, Lin H, Koutchmy S, Smartt RN. No Evidence of a Circumsolar Dust Ring from Infrared Observations of the 1991 Solar Eclipse. Science 1992; 257:1377-80. [PMID: 17738279 DOI: 10.1126/science.257.5075.1377] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
During the past 25 years there have been many attempts to detect a possible dust ring around the sun, with contradictory results. Before the 1991 eclipse, infrared eclipse experiments used single-element detectors to scan the corona along the ecliptic for excess surface brightness peaks. The availability of relatively large-format infrared array detectors now provides a considerable observational advantage: two-dimensional mapping of the brightness and polarization of the corona with high photometric precision. The 1991 eclipse path included the high-altitude Mauna Kea Observatory, a further advantage to measure the corona out to large angular distances from the sun. Results are reported from an experiment conducted on Mauna Kea with a HgCdTe-array detector sensitive to wavelengths between 1 and 2.5 micrometers, using broad-band J, H, and K filters. Although the sky conditions were not ideal, the H- and K-band surface brightnesses clearly show the inhomogeneous structure in the K-corona and the elliptical flattening of the F-corona, but no evidence of a circumsolar, local dust component out to 15 solar radii.
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1129
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Lin H, Kenyon E, Miller S. Apical membrane pHi regulatory mechanisms in human retinal pigenent epithelium (RPE). Exp Eye Res 1992. [DOI: 10.1016/0014-4835(92)90837-i] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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1130
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1131
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Blank M, Soo L, Lin H, Henderson A, Goodman R. Changes in transcription in HL-60 cells following exposure to alternating currents from electric fields. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0302-4598(92)80021-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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1132
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Blank M, Soo L, Lin H, Henderson A, Goodman R. Changes in transcription in HL-60 cells following exposure to alternating currents from electric fields. J Electroanal Chem (Lausanne) 1992. [DOI: 10.1016/0022-0728(92)85095-k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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1133
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Lin H, Collins MF, Holden TM, Wei W. Magnetic structure of erbium. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:12873-12882. [PMID: 10001348 DOI: 10.1103/physrevb.45.12873] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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1134
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Lin H, Palffy-Muhoray P. TE and TM modes in a cylindrical liquid-crystal waveguide. OPTICS LETTERS 1992; 17:722-724. [PMID: 19794609 DOI: 10.1364/ol.17.000722] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We consider a cylindrical waveguide consisting of an inhomogeneous anisotropic liquid-crystal core embedded in an infinite homogeneous isotropic cladding. The wave equations for the pure modes are uncoupled but may have complex coefficients owing to the inhomogeneity and anisotropy of the liquid crystal. A simple numerical method is proposed for solving these equations. For the configuration considered, numerical results for the TE modes agree exactly with the analytical solution. For the TM modes, no analytical solution is available, and the unusual result obtained is that the phase of the fields inside the core depends on the distance from the cylinder axis.
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1135
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Lin H, Konieczny SF. Identification of MRF4, myogenin, and E12 oligomer complexes by chemical cross-linking and two-dimensional gel electrophoresis. J Biol Chem 1992; 267:4773-80. [PMID: 1311321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The muscle-specific regulatory factors MRF4 and myogenin, as well as the ubiquitous factor E12, belong to a protein family which shares a common structural motif referred to as the basic helix-loop-helix domain. Recent studies have demonstrated that MRF4 and myogenin, in the presence of E12, bind efficiently to enhancer regions of muscle-specific genes, thereby activating their transcription. Although several lines of evidence suggest that MRF4 and E12 or myogenin and E12 hetero-oligomers exist, direct studies revealing the composition of these protein complexes have not been reported. Here, we demonstrate that MRF4 and myogenin preferentially form heterodimers with E12 in solution and that heterodimer formation in vitro is greatly enhanced when the two proteins are co-synthesized. Utilizing a novel two-dimensional gel electrophoresis system, we have found that MRF4 and myogenin, when complexed with E12, bind as heterodimers to the E-box consensus sequences associated with the troponin I, M-creatine kinase, and myosin light chain gene enhancers. In all cases, higher order oligomer structures were not detected, demonstrating that in vitro DNA binding abilities of these basic helix-loop-helix proteins require heterodimer formation.
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1136
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Lin H, Chensue SW, Strieter RM, Remick DG, Gallagher KP, Bolling SF, Kunkel SL. Antibodies against tumor necrosis factor prolong cardiac allograft survival in the rat. J Heart Lung Transplant 1992; 11:330-5. [PMID: 1576139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Tumor necrosis factor (TNF)-alpha has significant biologic actions in many circumstances, such as infectious diseases, ischemia/reperfusion injury, and delayed-type hypersensitivity reactions. Based on the hypothesis that manipulation of TNF can play an important role in treatment of heart transplant rejection, the objective of this study was to determine whether anti-TNF antibodies could prolong cardiac allograft survival. Hearts from brown rats were transplanted to the necks of recipient Lewis rats. Graft survival was determined by direct palpation of the heart; complete graft rejection was defined by cessation of contraction. In untreated rats, the hearts were rejected 6.8 +/- 0.6 days (n = 10; mean +/- SEM) after transplantation. The mononuclear cell infiltrate in the transplanted hearts stained intensely for TNF by immunohistochemistry, indicating that TNF was present within the inflammatory cells associated with the rejection process. In rats receiving a single injection of anti-TNF antibody at the time of transplantation (n = 6), however, graft survival was nearly doubled (12.7 +/- 1.4 days; p less than 0.001 vs controls). Prolonged cardiac graft survival was also evident if the anti-TNF treatment was delayed until 1 day (n = 5; rejection at 16.2 +/- 2.4 days; p less than 0.001 vs controls) or even 3 days after transplantation (n = 5; rejection at 11.4 +/- 2.3 days; p less than 0.005 vs controls). Treatment at 5 days after transplantation, however, was not effective (n = 3; rejection at 7.7 +/- 0.6 days; p, not significant vs controls). The data indicate that a single bolus of anti-TNF antibodies can delay heart transplant rejection, even when administered up to 3 days after implantation, supporting the potential utility of anti-TNF therapy for treatment of heart transplant rejection.
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1137
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Lin H, Konieczny S. Identification of MRF4, myogenin, and E12 oligomer complexes by chemical cross-linking and two-dimensional gel electrophoresis. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42899-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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1138
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Blümel R, Davidson IH, Reinhardt WP, Lin H, Sharnoff M. Quasilinear ridge structures in water surface waves. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 45:2641-2644. [PMID: 9907292 DOI: 10.1103/physreva.45.2641] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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1139
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Brower DL, Yu CX, Bravenec RV, Lin H, Luhmann NC, Peebles WA, Ritz CP, Smith BA, Wootton AJ, Zhang ZM, Zhao SJ. Brower et al. reply. PHYSICAL REVIEW LETTERS 1992; 68:892. [PMID: 10046020 DOI: 10.1103/physrevlett.68.892] [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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1140
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Bolling SF, Kunkel SL, Lin H. Prolongation of cardiac allograft survival in rats by anti-TNF and cyclosporine combination therapy. Transplantation 1992; 53:283-6. [PMID: 1738921 DOI: 10.1097/00007890-199202010-00006] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cyclosporine is well known to have many adverse side effects. However, while decreasing the dosage of CsA can reduce its toxicity, this also lowers its immunosuppressive effectiveness. Additionally, anti-tumor necrosis factor has been demonstrated to have immunosuppressive activity and been shown to prolong cardiac allograft survival. This current study therefore investigated the efficacy of a combined therapy of anti-TNF with low-dose CsA in a rat heterotopic cardiac transplant model utilizing Brown-Norway donors and Lewis recipients. Control transplant recipients received no immunotherapy. Experimental animals received single-dose anti-TNF intraperitoneally on posttransplant days 0, 3, or 5 and/or low-dose CsA (1.5 mg/kg/day) intramuscularly from days 0 to 14 after transplantation. Rejection was determined by the lack of contractions in the transplanted heart. No animal received any other form of immunosuppression. Graft survival was significantly prolonged with combination CsA and anti-TNF therapy, suggesting a synergistic effect against acute cardiac allograft rejection, possibly from CsA and anti-TNF interacting at different levels of the recipient immune response. This form of combination therapy may hold promise for future immunosuppressive techniques.
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1141
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Lin H, Van't Veen SJ, Klein CP. Permucosal implantation pilot study with HA-coated dental implant in dogs. Biomaterials 1992; 13:825-31. [PMID: 1457675 DOI: 10.1016/0142-9612(92)90175-n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The histological response of transmucosal one-stage titanium dental implants coated with hydroxyapatite is described. The gingival adhesion to the implant was examined with regard to coated, partially coated or non-coated surfaces in the cervical region. From each coating type, 9 implants were inserted into dogs. Six months after the insertion, 19 implants could be evaluated, but 8 implants were lost. From these 19 implants, 6 implants showed severe pockets with inflammation up to the bony tissue. The 13 successful implants showed direct bone bonding with the hydroxyapatite coating and adhesion of submucosal connective tissue to the implant surface, with inflammation. The marginal gingiva showed slight inflammation. A totally coated implant will probably introduce inflammation by debris formation against the rough implant surface more easily. The hydroxyapatite coating often disappeared in the soft tissue or in the oral cavity. Bone which directly adapted to the coating seemed to prevent it from resorption.
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1142
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Yang XZ, Zhang BZ, Wootton AJ, Schoch PM, Richards B, Baldwin D, Brower DL, Castle GG, Hazeltine RD, Heard JW, Hickok RL, Li WL, Lin H, McCool SC, Simcic VJ, Ritz CP, Yu CX. The space potential in the tokamak text. ACTA ACUST UNITED AC 1991. [DOI: 10.1063/1.859774] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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1143
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Budick B, Chen J, Lin H. Bremsstrahlung technique for measuring the end point of tritium beta decay. PHYSICAL REVIEW LETTERS 1991; 67:2626-2629. [PMID: 10044476 DOI: 10.1103/physrevlett.67.2626] [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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1144
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Budick B, Chen J, Lin H. Half-Life of Molecular Tritium and the Axial-Vector Interaction in Tritium beta Decay. PHYSICAL REVIEW LETTERS 1991; 67:2630-2633. [PMID: 10044477 DOI: 10.1103/physrevlett.67.2630] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1145
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Abstract
A subsynaptic protein of Mr approximately 300 kD is a major component of Torpedo electric organ postsynaptic membranes and copurifies with the AChR and the 43-kD subsynaptic protein. mAbs against this protein react with neuromuscular synapses in higher vertebrates, but not at synapses in dystrophic muscle. The Torpedo 300-kD protein comigrates in SDS-PAGE with murine dystrophin and reacts with antibodies against murine dystrophin. The sequence of a partial cDNA isolated by screening an expression library with mAbs against the Torpedo 300-kD protein shows striking homology to mammalian dystrophin, and in particular to the b isoform of dystrophin. These results indicate that dystrophin is a component of the postsynaptic membrane at neuromuscular synapses and raise the possibility that loss of dystrophin from synapses in dystrophic muscle may have consequences that contribute to muscular dystrophy.
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1146
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Brower DL, Yu CX, Bravenec RV, Lin H, Luhmann NC, Peebles WA, Ritz CP, Smith BA, Wootton AJ, Zhang ZM, Zhao SJ. Confinement degradation and enhanced microturbulence as long-time precursors to high-density-limit tokamak disruptions. PHYSICAL REVIEW LETTERS 1991; 67:200-203. [PMID: 10044520 DOI: 10.1103/physrevlett.67.200] [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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1147
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Lin H, Miller SS. pHi regulation in frog retinal pigment epithelium: two apical membrane mechanisms. THE AMERICAN JOURNAL OF PHYSIOLOGY 1991; 261:C132-42. [PMID: 1858851 DOI: 10.1152/ajpcell.1991.261.1.c132] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This study demonstrates that the apical membrane of frog retinal pigment epithelium (RPE) contains two intracellular pH (pHi) regulatory mechanisms, an electrogenic Na-HCO3 cotransporter blocked by DIDS and an amiloride-inhibitable Na-H antiporter. pHi was studied using the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF). In these cells resting pHi equals 7.26 +/- 0.09 (n = 58). After an acid load (NH4Cl prepulse), pHi recovery required apical extracellular Na concentration ([Na]o) in HCO3 or HCO3-free Ringer. In HCO3 Ringer recovery was completely blocked by 1 mM apical DIDS (n = 5) but was not affected by absence of Cl. In HCO3-free Ringer, recovery was completely blocked by 1 mM apical amiloride (n = 3). At resting pHi, the intrinsic pH-buffering capacity of the cell is approximately 7.1 mM/pH and rises monotonically as pHi decreases. In HCO3 Ringer, the initial rate of acidification caused by apical Na removal, 0.39 +/- 0.03 pH/min (n = 26), was 80-90% inhibited by apical DIDS (n = 5) and 16% inhibited by 1 mM apical amiloride (n = 7), but not affected by absence of Cl. In HCO3 Ringer, initial rates of acidification induced by apical DIDS or amiloride were 0.11 +/- 0.06 (n = 5) and 0.03 +/- 0.02 pH/min (n = 7), respectively. These results indicate that the Na-HCO3 cotransporter accounts for 80-90% of the acid extrusion from frog RPE cells. Increasing apical [K]o from 2 to 5 mM approximates the in vivo apical [K]o changes during a light-dark transition and alkalinizes the cells. [K]o-induced alkalinization had an initial rate of 0.11 +/- 0.02 pH/min (n = 16), which was approximately 75% inhibited by apical DIDS (to 0.04 +/- 0.01 pH/min, n = 7) and completely blocked by HCO3/CO2 removal from both bathing solutions. [K]o-induced pHi changes alter RPE transport mechanisms and may affect RPE-photoreceptor interactions.
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1148
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Bolling SF, Lin H, Annesley TM, Boyd JA, Gallagher KP, Levy RJ. Local cyclosporine immunotherapy of heart transplants in rats enhances survival. J Heart Lung Transplant 1991; 10:577-83. [PMID: 1911801] [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
High-dose systemic cyclosporine (CyA) administration frequently results in severe side effects. To evaluate a means of limiting the adverse effects of CyA, we implanted CyA-collagen matrices (0.2 or 1 mg/kg/day released) around the cardiac homografts at the time of rat heterotopic (neck) heart transplantation. Control animals received empty collagen (nondrug) matrix implants. A fourth group received CyA matrix (1 mg/kg/day released), implanted in a distal subdermal leg pouch at the time of heart transplantation. Rejection was determined by the absence of contraction in the transplanted heart. No animal received any other immunosuppression. Parallel groups of animals had whole blood, heart, and kidney CyA levels measured on the sixth posttransplant day. Local immunosuppression with high-dose CyA in a controlled-release matrix resulted in a significant survival advantage (mean survival time, 17.1 days; control, 6.9 days; p less than 0.001). The lower dose of CyA also demonstrated significant survival benefits (10.1 days), with clinically negligible blood CyA levels and very low kidney CyA levels. Both doses of epicardial local release CyA were well absorbed locally, resulting in very high CyA levels in cardiac tissue. Local immunotherapy of transplanted hearts with CyA was shown to be an effective means of preventing rejection. If this technology can be developed, this approach may prove advantageous clinically, both in extending transplantation and in minimizing systemic side effects of immunosuppression.
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1149
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Lin H, Rebelsky L, Collins MF, Garrett JD, Buyers WJ. Magnetic structure of UNi2Si2. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 43:13232-13239. [PMID: 9997148 DOI: 10.1103/physrevb.43.13232] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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1150
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Broholm C, Lin H, Matthews PT, Mason TE, Buyers WJ, Collins MF, Menovsky AA, Mydosh JA, Kjems JK. Magnetic excitations in the heavy-fermion superconductor URu2Si2. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 43:12809-12822. [PMID: 9997095 DOI: 10.1103/physrevb.43.12809] [Citation(s) in RCA: 170] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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