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Black AR, Jensen D, Lin SY, Azizkhan JC. Growth/cell cycle regulation of Sp1 phosphorylation. J Biol Chem 1999; 274:1207-15. [PMID: 9880488 DOI: 10.1074/jbc.274.3.1207] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sp1 sites can mediate growth/cell cycle induction of dihydrofolate reductase in late G1 (Jensen, D. E., Black, A. R. Swick, A. G., and Azizkhan, J. C. (1997) J. Cell. Biochem. 67, 24-31). To investigate mechanisms underlying this induction, effects of serum stimulation on regulation of Sp1 were examined. In Balb/c 3T3 cells, serum stimulation did not affect Sp1 synthesis or the relative binding of Sp1 family members to DNA; however, it did result in a rapid, approximately 2-fold increase in Sp1 levels and an approximately 3-fold increase in specific Sp1 phosphorylation in mid-G1. In normal human diploid fibroblasts, serum stimulation also increased Sp1 phosphorylation in mid-G1 but did not affect Sp1 levels. Therefore, Sp1 phosphorylation is regulated in a growth/cell cycle-dependent manner which correlates temporally with induction of dihydrofolate reductase transcription. Further studies revealed a kinase activity specifically associated with Sp1 in a growth-regulated manner. This activity is distinct from purified kinases previously shown to phosphorylate Sp1 in vitro and phosphorylates Sp1 between amino acids 612 and 678 in its C terminus, a region also phosphorylated in mid-G1 in vivo. Therefore, this study indicates that phosphorylation of the C terminus of Sp1 may play a role in the cell cycle regulation of its transcriptional activity.
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Lin SY, Chen KS, Teng HS. Effect of protective colloids on the induction of polymorphic changes in indomethacin agglomerates after solvent evaporation from o/w emulsions. J Microencapsul 1999; 16:39-47. [PMID: 9972501 DOI: 10.1080/026520499289293] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Indomethacin (IMC) agglomerates were prepared by the solvent evaporation process from o/w emulsions containing different protective colloids in the external aqueous solution. The types of protective colloids inducing the polymorphic transformation of IMC in the agglomerates without wall material were investigated. The composition and its polymorphs were evaluated from the X-ray diffraction patterns, IR spectra and DSC thermograms. The results indicate that when pectin, beta-cyclodextrin, sodium alginate or sodium dodecyl supphase acted as a protective colloid, the respective IMC agglomerates consisted only of the alpha form of IMC. When gelatin or hydroxypropyl methylcellulose was used as a protective colloid, the amorphous, alpha and gamma forms as well as methylene chloride solvates of IMC were found in the IMC agglomerates. There was only methylene chloride solvate of IMC with a small amount of amorphous form in the IMC agglomerates prepared from albumin as a protective colloid, while IMC agglomerates prepared from methylcellulose, polyvinyl alcohol or biosoluble polymer consisted of the mixture of amorphous and alpha forms, and methylene chloride solvate of IMC. When polyvinyl pyrrolidone was applied to act as a protective colloid, the mixture of methylene chloride solvate and gamma form of IMC with less quantity of amorphous form was found in its IMC agglomerates. This strongly suggests that the composition of IMC agglomerates prepared from the solvent evaporation process was significantly influenced by the type of protective colloids used.
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Fleming JG, Lin SY. Three-dimensional photonic crystal with a stop band from 1.35 to 1.95 microm. OPTICS LETTERS 1999; 24:49-51. [PMID: 18071404 DOI: 10.1364/ol.24.000049] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A combination of advanced silicon-processing techniques was used to create three-dimensional (3D) photonic crystals with a 180-nm minimum feature size. The resulting 3D crystal displayed a strong stop band at optical wavelengths from lambda=1.35 microm to lambda=1.95 microm . This is believed to be the smallest 3D crystal with a complete 3D photonic bandgap ever created.
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Abstract
The candidate tumour suppressor gene TSG101, located on chromosome 11p15, has been associated with frequent intragenic deletion in uncultured primary human breast cancers. Using paired tumour and normal tissues from surgical specimens, we performed nested reverse transcriptase-polymerase chain reaction and direct sequencing to analyse TSG101 exons 1-6 from 32 gastric, 30 colorectal and 16 oesophageal cancers. Truncated transcripts, were found in both tumour and normal tissues from the stomach (15.6 and 12.5%), colon (13.3 and 3.3%) and oesophagus (25 and 25%). Multiple truncated transcripts in individual specimens were also observed. Two types of splicing patterns, one with three to six bases homology at the deletion junction (25.9%), the other with donor site 5' GT and acceptor site 3' AG (55.6%), were the most common patterns. We conclude that in gastrointestinal cancers, truncated transcripts of TSG101 gene occur not uncommonly and do so with a specific splicing pattern.
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Lin SY, Chen KS, Lin YY. pH of preparations affecting the on-off drug penetration behavior through the thermo-responsive liquid crystal-embedded membrane. J Control Release 1998; 55:13-20. [PMID: 9795002 DOI: 10.1016/s0168-3659(98)00024-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A liquid crystal (cholesteryl oleyl carbonate, COC)-embedded membrane with a controlled rate and higher reversibly thermo-responsive function was successfully fabricated by the vacuum filtration method. The aim of this study was to investigate the effect of the pH of aqueous solutions and gel preparations on the penetration of salbutamol sulfate through this thermo-responsive COC-embedded membrane. The results indicate that the on-off switching penetration behavior of salbutamol sulfate through the COC-embedded membrane in response to a repeatedly exchanging temperature cycle (10 <=> 25 degreesC) is not influenced by the pH of the medium. However, the pH-dependent ionization of salbutamol and the viscosity of the gel base, as well as the interaction between salbutamol and carbopol, might change the amount and the rate of salbutamol sulfate that penetrates across this COC-embedded membrane.
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Lin SY, Chow E, Hietala V, Villeneuve PR, Joannopoulos JD. Experimental demonstration of guiding and bending of electromagnetic waves in a photonic crystal. Science 1998; 282:274-6. [PMID: 9765148 DOI: 10.1126/science.282.5387.274] [Citation(s) in RCA: 553] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The routing and interconnection of optical signals through narrow channels and around sharp corners are important for large-scale all-optical circuit applications. A recent computational result suggests that photonic crystals may offer a novel way of achieving this goal by providing a mechanism for guiding light that is fundamentally different from traditional index guiding. Waveguiding in a photonic crystal and near 100 percent transmission of electromagnetic waves around sharp 90 degree corners were observed experimentally. Bending radii were made smaller than one wavelength.
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Shih YF, Yang CM, Lin SY, Huang JS, Lin LL, Hung PT. Effects of lid suturing and trans-scleral cryotherapy on ocular growth in a piglet model. Optom Vis Sci 1998; 75:758-62. [PMID: 9798216 DOI: 10.1097/00006324-199810000-00021] [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: 11/26/2022] Open
Abstract
PURPOSE To study whether lid suturing can induce axial myopia and explore whether trans-scleral cryotherapy can affect ocular growth in piglets or not. METHODS A total of fourteen 2- to 3-week-old piglets were studied. Three groups were included: lid suture, cryotherapy, and both lid suture/cryotherapy groups. The lid suturing group (N = 6) was given lid suturing to produce visual deprivation. The cryotherapy group (N = 4) received trans-scleral cryotherapy 360 degrees to encircle anterior to the equator. Both treatment groups (N = 4) received both cryotherapy and lid suturing. The cycloplegic refraction, corneal power, biometric axial length, and intraocular pressure (IOP) were measured before the experiments and 4 months later. RESULTS Mild axial myopia was induced in five lid-sutured eyes of the lid suturing group. The ocular refraction and eye size of cryotherapy eyes were not different from the control eyes in the cryotherapy group. More myopia was found in all four piglets that received both cryotherapy and lid suturing. CONCLUSIONS Lid suturing can induce axial myopia; however, cryotherapy did not affect normal eye growth and did not prevent the development of lid suturing myopia in piglets.
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Abstract
From 1988 to 1995, 96 patients (161 feet) underwent a modified Mitchell distal metatarsal osteotomy performed for mild-to-moderate hallux valgus. On AP x-rays of the standing foot, the average intermetatarsal angle was corrected from 15 degrees to 9 degrees, and the first metatarsophalangeal angles were corrected from an average of 41 degrees to 15 degrees. Criteria for evaluation of clinical results included relief of pain, appearance of foot, and shoe wear. After an average follow-up of 38 months, the overall satisfaction rate was 92.5%. Complications included 13 pin tract infections, two delayed unions, and two correction losses. The most common late sequela was transfer metatarsalgia of the lesser toes, which occurred in 20 feet (12.4%), leading to some dissatisfaction. The Mitchell osteotomy can be used on cases with less than 20 degrees of intermetatarsal angle, offering a stable construct with easy postoperative care.
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Lin SY, Li MJ, Liang RC, Lee SM. Non-destructive analysis of the conformational changes in human lens lipid and protein structures of the immature cataracts associated with glaucoma. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 1998; 54A:1509-1517. [PMID: 9807241 DOI: 10.1016/s1386-1425(98)00175-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Previous study has supposed a possible mechanism of exacerbating cataract formation in cataractous human lens capsules induced by hypertension or glaucoma. To clarify the glaucoma-induced cataract formation of the eyes lens, changes in the human lens lipid and protein structures of immature cataractous patients with or without glaucoma were investigated. Two normal lenses, ten immature cataractous lenses without any complication and four immature cataractous lenses with glaucoma were used after surgical operation. Each de-capsulated human lens sample was sliced with a number 15 surgical blade. The intact nuclear lens regions were used for non-destructive analysis. The lens lipid and protein structures, as well as compositions of these lens samples, were determined using a Fourier transform infrared (FTIR) microspectroscopy with second-derivative, de-convolution and curve-fitting methods. The results indicate that the IR spectrum of glaucomatous lenses appeared as a shoulder only at 2853 cm-1, thus the composition of the symmetric CH2 stretching band at 2853 (2852) cm-1 decreased more significantly in glaucomatous lens to only one half of that in normal and immature cataractous lenses. The composition of the asymmetric CH3 stretching band at 2965 cm-1 for normal lens decreases markedly from 32 to 20% for immature cataractous lenses with or without glaucoma. The compositional ratio of component at 2965 cm-1 to component at 2928 (2930) cm-1 for normal lenses was about 0.702, and that ratio for cataractous lenses without glaucoma was 0.382 but for glaucomatous lenses was 0.377. The maximum peak position of amide I band for IR spectra of the normal lens, immature cataractous lenses without complications or glaucomatous lenses appeared respectively at 1632, 1630 or 1622 cm-1, assigned to beta sheet structure. A marked difference in peak intensity of amide I band for the normal lenses and immature cataractous human lenses with or without glaucoma was observed. The peak intensity ratio of amide I/amide II (1632/1545 cm-1) for normal lenses was in the range of 2.20-2.33, whereas in the spectra of immature cataractous lenses without glaucoma this ratio (1630/1545 cm-1) was 1.28-1.41 but was 1.04-1.13 for glaucomatous lens in the intensity ratio of 1622/1545 cm-1. The intensity of the glycogen bands in the wavenumber region 1135-1076 and 1069-1032 cm-1 was found to increase for the immature cataractous lenses with or without glaucoma, as compared with the normal ones. The peaks ranging from 1633 to 1610 cm-1 assigned to beta-sheet structure also exhibited a pronounced compositional difference, particularly in glaucomatous lenses. The human lens lipid and protein secondary structures were more affected by glaucoma. Higher protein side chains and reduced lipid content contributed predominantly to the CH stretching vibrations of normal lens structure, whereas high lipid content and less protein side chains dominated the CH stretching vibrations of cataractous lenses with or without glaucoma. Decrease alpha-helix and random coil structures but enhanced beta-sheet structure in the immature cataractous human lens induced by glaucoma might result from the formation of intermolecular hydrogen-bonding insoluble protein aggregates that modify the secondary structure of protein in lenses.
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Suen PC, Wu K, Xu JL, Lin SY, Levine ES, Black IB. NMDA receptor subunits in the postsynaptic density of rat brain: expression and phosphorylation by endogenous protein kinases. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 59:215-28. [PMID: 9729394 DOI: 10.1016/s0169-328x(98)00157-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-methyl-D-aspartate (NMDA) receptors (NRs) play critical roles in diverse synaptic processes in the brain. However, subcellular distribution, spatiotemporal expression and regulation of NR subunits in brain synapses are unknown. We report that NR1 and NR2A-2C subunits are all enriched in the postsynaptic density (PSD), which plays critical roles in trophin-mediated synaptic plasticity. Significant expression of NRs was observed the first two weeks after birth, during synaptogenesis, and in adulthood. Functional diversity of NRs, resulting from heterogeneous composition, was supported by the finding that different NR2 subunits were associated in a region-specific manner with NR1. Phosphorylation of NR1, a key subunit of the NMDA receptor-channel complex, was significantly enhanced by activators of calmodulin (CaM) kinases (CKs) or protein kinase C (PKC), but not by those of PKA. Co-immunoprecipitation studies revealed that NR1 was physically associated with functionally active PKCgamma and the major PSD protein (mPSDp) through noncovalent interactions. Our results suggest that NMDA receptors play roles in postsynaptic mechanisms in a subunit-, composition-, brain region- and developmental-specific manner. Our findings also indicate that the PSD is a coherent functional unit containing protein kinases that potentially regulate NMDA receptor function via phosphorylation.
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Lin SY, Ho CJ, Li MJ. Thermal stability and reversibility of secondary conformation of alpha-crystallin membrane during repeated heating processes. Biophys Chem 1998; 74:1-10. [PMID: 9742681 DOI: 10.1016/s0301-4622(98)00152-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Reflectance FT-IR/DSC microspectroscopy was first used to study the structural conformation of alpha-crystallin membranes in the heating-cooling-reheating cycle. The thermotropic transition and the changes in secondary structure of alpha-crystallin membrane during heating and reheating processes were investigated. A thermal transition ranging between 50 and 70 degrees C with a midpoint at 60 degrees C for the alpha-crystallin membrane was easily obtained from the three-dimensional plots of the reflectance FT-IR spectra as a function of temperature. The secondary structural components of the alpha-crystallin membrane were modified step-by-step with the increase of temperature from 25 to 120 degrees C, but restored to original values after cooling to 25 degrees C. During the heating process, the compositions of the alpha-helix, random coil and beta-sheet structure decreased with temperature, but the content of the beta-turn structure increased, however, all of them were restored after cooling. The absence of significant alteration in the secondary structures for the alpha-crystallin membrane before and after the first-heating process strongly suggests the high thermal stability and reversibility of alpha-crystallin. Interestingly, the thermal behavior of the first-heated alpha-crystallin membrane during the reheating process exhibited a unique thermal behavior with two transitional temperatures at 35-50 and 55-70 degrees C. The reflectance FT-IR/DSC microscopic data indicated that alpha-crystallin in the membrane state had higher thermal stability and reversibility.
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Hsiue GH, Liao CM, Lin SY. Effect of drug-polymer interaction on the release characteristics of methacrylic acid copolymer microcapsules containing theophylline. Artif Organs 1998; 22:651-6. [PMID: 9702316 DOI: 10.1046/j.1525-1594.1998.04804.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Theophylline anhydrate microcapsules with different amounts of MA/MMA copolymer (Eudragit L) were prepared by the solvent evaporation method. Qualitative as well as quantitative investigation of the drug-polymer interaction by Fourier transform infrared (FTIR) spectroscopy with a curve fitting program was undertaken. The release mechanisms of theophylline in pH 1.2 and pH 6.8 media were also studied to elucidate the effect of drug-polymer interaction on the release characteristics of microcapsules. Direct evidence for a hydrogen bonding interaction between theophylline and Eudragit L in microcapsules was obtained. Moreover, the fraction of hydrogen bonded theophylline increased with the increase of Eudragit L. The dissolution of theophylline from microcapsules exhibited an enteric-coated release property. The drug release mechanism was found to fit the Higuchi matrix model in the simulated gastric acid condition, but drug release was much more rapid in the pH 6.8 buffer solution. The drug release rate decreased as the composition of theophylline increased, and it was proportional to the fraction of hydrogen bonded theophylline. These results suggest that the increased fraction of hydrogen bonded theophylline in microencapsulation might improve the mixing and dispersibility of theophylline in the Eudragit L matrix, thus resulting in the increase of the release rate of theophylline from microcapsules.
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Kung CC, Lin SY, Tang CS, Wu TJ, Sun WZ. Clinical study of failure in continuous spinal anesthesia with bupivacaine. Kaohsiung J Med Sci 1998; 14:486-91. [PMID: 9780598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
BACKGROUND Continuous spinal anesthesia (CSA) has been considered to be better in temporal and dose flexibility, as well as hemodynamic stability than single dose spinal anesthesia. However, the failure of spinal anesthesia is not a rare experience for anesthesiologists. Here we present our experience in solving the problem and discuss the possible causes for the failure. METHODS 236 cases were studied retrospectively from January to December in 1996. All were over 65 years old, ASA III, scheduled for transurethral procedures or orthopedic operation. CSA was performed with 0.2% bupivacaine. Failed CSA was confirmed by positive pin-prick test at T10 dermatome(umbilicus) 30 minutes after 20 mg bupivacaine was injected. For failed cases, 5 mL 1% lidocaine was injected intrathecally for rescue. The failure rate, sensory and motor blockade, success rate by changing to lidocaine and its dosage were recorded. RESULTS Eleven of 236 cases (4.7%) were considered spinal failure since the initial 20 mg bupivacaine could not provide adequate T10 anesthesia in 30 minutes. Addition of 5 mL 1% lidocaine produced a profound sensory and motor blockade in 9 cases, while further lidocaine injection was required in two cases. The success rate by rescuing lidocaine was 100% with an average lidocaine consumption by 52.5 +/- 4.5 mg. DISCUSSION Factors contributed to failure spinal anesthesia including failure of technique, errors of judgment, maldistribution and failure of local anesthetic itself. However, we thought that change of pH value of local anesthetic in CSF may play a great part in these failed CSAs. Despite the reasons for failure, we demonstrate that failure of continuous spinal anesthesia by 0.2% bupivacaine can be readily resolved by 1% lidocaine.
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Lin SY, Hsu HS, Liang RC, Li MJ. Integrality of benign prostatic hyperplasia tissues after transurethral thermotherapy evidenced by transmittance fourier transform infrared spectroscopy combined with thermal analyzer. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 1998; 32:256-60. [PMID: 9764451 DOI: 10.1080/003655998750015403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Transmittance Fourier transform infrared microspectroscopy combined with differential scanning calorimetry was used to simulate the clinically transurethral thermotherapy of benign prostatic hyperplasia (BPH) by in vitro isothermal determination. The simulative study to the thermotherapy of epithelium or stroma in BPH tissue was performed at 47 degrees C for 3 h, like clinical therapy. Whether thermal treatment can induce changes in the secondary structure of epithelium or stroma in BPH tissue was investigated. The results indicate that the epithelium and stroma in BPH tissue had different protein secondary structures, due to the different compositions of the epithelium and stroma. No significant change was evidenced in secondary structure for each sample either before or after isothermal study, suggesting the integrality and safety of BPH thermotherapy in a 47 degrees C for 3 h treatment course.
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Lee LS, Chi CW, Liu HC, Cheng CL, Li MJ, Lin SY. Assessment of protein conformation in human benign and malignant astrocytomas by reflectance Fourier transform infrared microspectroscopy. Oncol Res 1998; 10:23-7. [PMID: 9613454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The secondary structure and composition of protein in the tissues of benign and malignant astrocytomas were determined by reflectance Fourier-transform infrared (FT-IR) microspectroscopy. The peak maximum of IR spectra of the tissues from recurrent malignant astrocytoma markedly appeared at higher frequency (1655 or 1663 cm(-1)), which was significantly different from that of the tissues from benign astrocytoma at 1651 cm(-1) and tissues from malignant astrocytoma at 1652 cm(-1). Malignant astrocytoma indicated slightly different compositions in the protein secondary structure from benign astrocytoma. However, a significant increase in beta-turn structure but a marked decrease in beta-sheet and random coil structures were observed in the protein secondary structure of the recurrent malignant astrocytoma. The phenomenon was more pronounced in recurrent malignant astrocytoma pretreated with radiation and chemotherapy. The rapid cell proliferation and cell differentiation of malignant astrocytoma with or without recurrence might be the possible explanations for the different compositions of protein conformational structures.
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Mazza G, Housset D, Piras C, Gregoire C, Lin SY, Fontecilla-Camps JC, Malissen B. Glimpses at the recognition of peptide/MHC complexes by T-cell antigen receptors. Immunol Rev 1998; 163:187-96. [PMID: 9700511 DOI: 10.1111/j.1600-065x.1998.tb01197.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
More than a decade after the first description of the primary structure of a T-cell antigen receptor (TCR), the recent determination of the crystal structure of several unliganded TCR ectodomains and of two TCRs complexed to peptide-MHC ligand provides a structural basis for understanding the initial event that triggers T-cell activation. This review focuses on the topology of the variable (V) domains found in TCRs and immunoglobulins and attempts to delineate the structural features that may render the TCR complementarity-determining regions particularly suited to dock on the peptide/MHC surface. Finally, the available TCR structures provide an opportunity to re-evaluate the molecular basis for intrathymic positive selection as well as the mechanisms that make a given TCR neither infinitely specific, nor so flexible that it engages productively any MHC-binding peptides.
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Lin SY, Wong WW, Fung CP, Liu CE, Liu CY. Acinetobacter calcoaceticus-baumannii complex bacteremia: analysis of 82 cases. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 1998; 31:119-24. [PMID: 10596990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Eighty-two cases of Acinetobacter calcoaceticus-baumannii complex bacteremia were identified during a 33-month period, from November 1993 to July 1996, at the Veterans General Hospital, Taipei. All cases were due to hospital-acquired infections, with 28 cases of polymicrobial bacteremia. Most patients had severe debilitating conditions: 26 had malignancies, 40 required stay in Intensive Care Unit and 17 had undergone major operations. The main predisposing factors included central venous catheterization, endotracheal intubation or tracheostomy, prior antibiotic therapy and prolonged hospitalization. Amikacin, tobramycin, and ceftazidime were the most effective agents in vitro against A. calcoaceticus-baumannii complex. 32 patients (39 %) died during hospitalization, 19 of the cases (23 %) directly attributed to septicemia. Factors that adversely influenced mortality included polymicrobial bacteremia, inappropriate antimicrobial therapy and prior antibiotic treatment. Of particular interest is the fact that none of the patients who did not receive appropriate antimicrobial therapy survived. Early diagnosis and appropriate antibiotic therapy are critical for improving the prognosis of A. calcoaceticus-baumannii complex bacteremia.
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Lin SY, Constantine-Paton M. Suppression of sprouting: An early function of NMDA receptors in the absence of AMPA/kainate receptor activity. J Neurosci 1998; 18:3725-37. [PMID: 9570803 PMCID: PMC6793148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Electrophysiological studies have documented the existence of synapses showing only NMDA ionotropic glutamate receptor function that are therefore presumably "silent" at resting membrane potentials. Silent synapses are more prevalent in young than in older neurons, and NMDA receptor activity at such contacts may facilitate the appearance of functional AMPA receptors. However, it is uncertain whether such silent synapses actually have a function in young neurons independent of AMPA receptor induction. Using a newly characterized culture system for neurons from larval Xenopus tecta, we show that blocking NMDA receptors or preventing changes in intracellular free Ca2+ concentration with BAPTA AM significantly increases neurite sprouting and elongation in contacted but not in isolated neurons. Blocking AMPA/KA receptors or Na+-dependent action potentials does not mimic this effect. Moreover, in these young neurons, NMDA receptor-dependent Ca2+ responses to glutamate measured with confocal fluo-3 imaging are retained during AMPA/KA receptor blockade. The data suggest that many of the young contacts in these cultures are active even though they use only NMDA ionotropic glutamate receptors. Calcium influx through the NMDA receptor at these contacts seems to reduce neurite motility. This effect should lead to the accumulation of glutamatergic inputs on NMDA receptor-expressing dendrites, which could facilitate the onset of AMPA/KA receptor function and the action potential-dependent phase of synaptogenesis.
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Carriero D, Aberman J, Lin SY, Hill A, Makriyannis A, Salamone JD. A detailed characterization of the effects of four cannabinoid agonists on operant lever pressing. Psychopharmacology (Berl) 1998; 137:147-56. [PMID: 9630001 DOI: 10.1007/s002130050604] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The present experiments were conducted to investigate the effects of four cannabimimetics on detailed temporal parameters of operant responding. In this study, the behavioral output during performance of a fixed ratio 5 schedule of reinforcement was recorded by a computer program that measured the response initiation time (IT; time interval between the offset of one lever press and the onset of the next) and the response duration (the amount of time that elapses from the onset to the offset of one lever press) of each lever press. ITs were further partitioned into fast responses (IT=0.0-1.0 s), short pauses (IT= 1.0-2.5 s), and long pauses (IT>2.5 s). Four cannabimimetic agents were assessed in this study: (R)-methanandamide (AM 356), a hydrolytically stable analog of arachidonylethanolamide, an endogenous ligand for the CB1 receptor; CP-55,940, a potent non-classical synthetic ligand; (-)-delta8-tetrahydrocannabinol (delta8-THC), an isomer of the naturally occurring delta9-THC; and WIN 55,212-2, a synthetic aminoalkylindole. All four of the cannabimimetic drugs tested significantly suppressed operant lever pressing in a dose dependent manner. The rank order of potencies observed in the present study was CP-55,940>>WIN-55,212-2>delta8-THC>AM 356, which is consistent with the rank order of affinities for the CB1 receptor shown by these drugs. All of the cannabimimetics substantially increased average IT, and also increased duration time. There was a substantial increase in average length of long pauses, and statistically significant but very small changes in the local rate of responding as measured by the average length of fast ITs. Cannabinoid-treated rats were largely immobile during pauses in responding, and these animals showed several signs of ataxia and catalepsy at the doses that suppressed lever pressing. Together with other data, the present results suggest that CB1 stimulation leads to motor effects that are associated with a suppression of lever pressing.
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Lin SY, Chen KS, Teng HH. Functionality of protective colloids affecting the formation, size uniformity and morphology of drug-free polylactic acid microspheres. J Microencapsul 1998; 15:383-90. [PMID: 9608400 DOI: 10.3109/02652049809006865] [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: 11/13/2022]
Abstract
Drug-free polylactic acid (PLA) microspheres were prepared by an emulsification-solvent evaporation technique using different types of protective colloids. The influence of five types of hydrophilic prolymers (polysaccharides, proteins, synthetic cellulose derivatives, synthetic nonionic polymers and surfactants) on the formation, size uniformity and morphology of PLA microspheres was investigated. Four characteristic functions (surface activity, viscosity, electric charge and interfacial film formation) of the hydrophilic polymer aqueous solutions were used to evaluate the efficacy of these protective colloids used. The results indicate that these four functions were the key parameters to achieve the formation of PLA microspheres. The best protective colloid should have high surface activity, optimum viscosity, adequate electric charge, and form an interfacial film to give a higher recovery, better size uniformity and smoother topography of the PLA microspheres.
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Peng HJ, Chang ZN, Lin SY, Han SH, Chang CH. Chemical denaturation of ovalbumin abrogates the induction of oral tolerance of mouse reaginic antibody responses. Scand J Immunol 1998; 47:475-80. [PMID: 9627132 DOI: 10.1046/j.1365-3083.1998.00333.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effect of chemical denaturation of ovalbumin (OVA) on the induction of oral tolerance of reaginic antibody responses was studied. Both urea-denatured OVA (UD-OVA) and carboxymethylated UD-OVA (CM-OVA) were purified by centrifugation. When compared with OVA and UD-OVA, CM-OVA had the least sensitizing capacity and allergenicity in IgE responses to OVA. BALB/c IgE, IgG1 and IgG antibody responses were suppressed by OVA, but not by UD-OVA or CM-OVA, fed prior to sensitization with OVA, UD-OVA, or CM-OVA in alum, respectively. The priming effect of specific IgG and IgG1 antibody responses was induced by CM-OVA fed prior to sensitization with OVA or CM-OVA. The proliferation of BALB/c spleen cells and their secretion of T helper type 2 (Th2) cytokines interleukin-4 (IL-4) and IL-5 were also orally tolerized by OVA, but not by denatured OVA. Although denatured OVA is hypoallergenic, the present result indicates that denaturation of a soluble protein prevents the induction of oral tolerance of Th2 responses.
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Lin SY, Cheng YM, Huang PJ, Tien YC, Yap WK. Modified Blair method for ankle arthrodesis. Kaohsiung J Med Sci 1998; 14:217-20. [PMID: 9589615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In this study, the ordinary Blair's ankle arthrodesis was modified by longitudinal oblique cutting to get the sliding bone graft, up side down grafting, and additional screw fixation at talar site with or without staples fixation of tibia-talar junction. The method of ankle arthrodesis was used on 34 cases from 1987 to 1990 with a 91.2% fusion rate and an average 5.6 months fusion time. The oblique cut bone graft provided larger contact surface to enhance bony fusion and the upside-down bone graft provided stronger tibia-talar bone bridge with thicker cortex for distal screw fixation and the distal screw fixation of bone graft to talus had the advantage of securing union and maintaining position. With such modifications, solid ankle arthrodesis could be obtained even without interarticular compression.
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Lin SY, Wu K, Levine ES, Mount HT, Suen PC, Black IB. BDNF acutely increases tyrosine phosphorylation of the NMDA receptor subunit 2B in cortical and hippocampal postsynaptic densities. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 55:20-7. [PMID: 9645956 DOI: 10.1016/s0169-328x(97)00349-5] [Citation(s) in RCA: 225] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
While neurotrophins are critical for neuronal survival and differentiation, recent work suggests that they acutely regulate synaptic transmission as well. Brain-derived neurotrophic factor (BDNF) enhances excitatory postsynaptic currents in cultured dissociated hippocampal neurons within 2-3 min through postsynaptic, phosphorylation-dependent mechanisms. Moreover, BDNF modulates hippocampal long-term potentiation, in which postsynaptic NMDA (N-methyl-D-aspartate) receptors (NRs) play a key role. We now report that BDNF acutely increases tyrosine phosphorylation of the specific NMDA receptor subunit NR2B, which has recently been shown to play a role in long-term potentiation. Incubation of BDNF with cortical or hippocampal postsynaptic densities for 5 min increased tyrosine phosphorylation of the NR2B subunits in a dose-dependent manner. A maximal increase to 165% of control phosphorylation occurred at a BDNF concentration of 2 ng/ml. The BDNF action appeared to be specific, since nerve growth factor, another member of the neurotrophin gene family, had no effect on NR2B phosphorylation. Further, BDNF action was selective, since it did not alter tyrosine phosphorylation of NR2A subunits. Our results suggest that tyrosine phosphorylation of NR2B subunits of the NMDA receptor may contribute to neurotrophin modulation of postsynaptic responsiveness and long-term potentiation.
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Lin SY, Lee RK, Hwu YM, Lin MH. Reproducibility of the revised American Fertility Society classification of endometriosis using laparoscopy or laparotomy. Int J Gynaecol Obstet 1998; 60:265-9. [PMID: 9544711 DOI: 10.1016/s0020-7292(97)00247-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To assess the discrepancy between laparoscopic and laparotomic scoring methods using the revised American Fertility Society (AFS) classification of endometriosis. METHOD In this prospective study, 84 patients with endometriosis were scored twice (laparoscopically and laparotomically) by the same subspecialty-certified reproductive endocrinologist. The magnitude of inter-method variability was reported quantitatively by the S.D. of the differences in scores between the pairs. The differences in the mean endometriosis scores between the two methods were assessed by the paired Student's t-test. P < 0.05 was considered as statistically significant. Discrepancy between the two methods in the staging of endometriosis patients was presented by kappa measure of agreement. RESULT There was considerable variability in the scores between the two scoring methods by the same observer. Among individual components of the scoring system, the greatest variability occurred in the ovarian endometriosis and cul-de-sac obliteration subscores, with the least variability observed for peritoneum endometriosis. The inter-method variation in score was sufficient to alter the endometriosis staging in 34.5% of patients, including a difference of two stages in 3.6% of patients. The kappa coefficient was 0.49, indicating fair-to-good agreement between the two scoring methods. CONCLUSION Inter-method variability between laparoscopic and laparotomic scoring methods was high for ovarian endometriosis subscore using the revised AFS classification of endometriosis. Agreement in endometriosis staging between the two methods was fair to good.
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Lin SY, Chang CL, Jap TS, Lin HD, Won JG. Genitourinary tuberculosis complicated with adrenal involvement and primary adrenocortical insufficiency: a case report. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1998; 61:170-4. [PMID: 9556950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genitourinary tuberculosis (TB) rarely involves the adrenal gland. A 67-year-old man presented with progressively hyperpigmented skin and an enlarged mass over both testes. Early morning plasma cortisol concentration was low and adrenocorticotropic hormone (ACTH) concentration was high. A rapid ACTH stimulation test revealed the absence of plasma cortisol response and confirmed a diagnosis of primary adrenocortical insufficiency. An abdomen computed tomography (CT) scan disclosed enlargement of the right adrenal gland and punctuate calcification over the left one. This is compatible with tuberculous adrenalitis. Currettage biopsy of the prostate demonstrated chronic granulomatous inflammation with Langerhan's giant cells, but without TB bacilli. Anti-TB treatment, in addition to glucocorticoid and mineralocorticoid replacement, was administered. The testicular mass decreased progressively though the results of a subsequent ACTH stimulation test, six months later, disclosed no significant change. A follow-up CT scan, one and a half years later, showed a decrease in the size of the right adrenal mass.
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