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1.
Eur J Appl Physiol ; 116(11-12): 2315-2326, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27699485

ABSTRACT

PURPOSE: We tested the hypothesis that both post-exercise and passive cold water immersion (CWI) increases PGC-1α and VEGF mRNA expression in human skeletal muscle. METHOD: Study 1 Nine males completed an intermittent running protocol (8 × 3-min bouts at 90 % [Formula: see text], interspersed with 3-min active recovery (1.5-min at 25 % and 1.5-min at 50 % [Formula: see text]) before undergoing CWI (10 min at 8 °C) or seated rest (CONT) in a counterbalanced, randomised manner. Study 2 Ten males underwent an identical CWI protocol under passive conditions. RESULTS: Study 1 PGC-1α mRNA increased in CONT (~3.4-fold; P < 0.001) and CWI (~5.9-fold; P < 0.001) at 3 h post-exercise with a greater increase observed in CWI (P < 0.001). VEGFtotal mRNA increased after CWI only (~2.4-fold) compared with CONT (~1.1-fold) at 3 h post-exercise (P < 0.01). Study 2 Following CWI, PGC-1α mRNA expression was significantly increased ~1.3-fold (P = 0.001) and 1.4-fold (P = 0.0004) at 3 and 6 h, respectively. Similarly, VEGF165 mRNA was significantly increased in CWI ~1.9-fold (P = 0.03) and 2.2-fold (P = 0.009) at 3 and 6 h post-immersion. CONCLUSIONS: Data confirm post-exercise CWI augments the acute exercise-induced expression of PGC-1α mRNA in human skeletal muscle compared to exercise per se. Additionally CWI per se mediates the activation of PGC-1α and VEGF mRNA expression in human skeletal muscle. Cold water may therefore enhance the adaptive response to acute exercise.


Subject(s)
Exercise/physiology , Hypothermia, Induced/methods , Immersion , Muscle, Skeletal/physiology , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Vascular Endothelial Growth Factor A/metabolism , Adaptation, Physiological/physiology , Adult , Cold Temperature , Humans , Male , Up-Regulation/physiology
2.
Bone Marrow Transplant ; 50(11): 1459-64, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26301966

ABSTRACT

We analyzed the incidence and risk factors for ocular GVHD in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Korea. In this retrospective, noncomparative, observational study, 635 subjects were included who had at least 2 years of follow-up ophthalmological examinations after allo-HSCT from 2009 to 2012 at Seoul St Mary's Hospital, Seoul, Korea. The mean duration between allo-HSCT and onset of ocular GVHD was 225.5±194.3 days. The adjusted incidence for acute ocular GVHD was 1.33% and that for chronic GVHD was 33.33%. In the multivariate analysis, preexisting diabetes mellitus (odds ratio (OR): 4.22, 95% confidence interval (CI): 1.66-10.72), repeated allo-HSCT (OR: 29.10, 95% CI: 1.02-8.28) and the number of organs that chronically developed GVHD by stage I (OR: 14.63, 95% CI: 9.81-21.84) increased risk of ocular GVHD. Careful monitoring of ocular GVHD is needed in patients with chronic GVHD in multiple organs and preexisting diabetes.


Subject(s)
Graft vs Host Disease/epidemiology , Hematopoietic Stem Cell Transplantation/adverse effects , Keratoconjunctivitis Sicca/epidemiology , Adult , Allografts , Comorbidity , Diabetes Mellitus/epidemiology , Female , Follow-Up Studies , Graft vs Host Disease/drug therapy , Graft vs Host Disease/etiology , Hematologic Diseases/therapy , Humans , Immunosuppressive Agents/therapeutic use , Incidence , Keratoconjunctivitis Sicca/drug therapy , Keratoconjunctivitis Sicca/etiology , Male , Middle Aged , Multiple Myeloma/therapy , Organ Specificity , Republic of Korea/epidemiology , Retrospective Studies , Risk Factors , Severity of Illness Index
4.
Cell Death Dis ; 4: e714, 2013 Jul 04.
Article in English | MEDLINE | ID: mdl-23828577

ABSTRACT

Members of the transforming growth factor beta (TGF-ß) superfamily are multifunctional cytokines that regulate several cellular processes, including cell cycle arrest, differentiation, morphogenesis, and apoptosis. TGF-ß promotes extracellular matrix production and morphological change. Morphogenetic responses to TGF-ß include cell migration and epithelial-mesenchymal transition (EMT), which are critical during embryogenesis, development of fibrotic diseases, and the spreading of advanced carcinomas. The purpose of this study was to clarify how TGF-ß regulates the fate of retinal pigment epithelial (RPE) cells. TGF-ß1 promoted cell cycle progression and phosphorylation of retinoblastoma protein (Rb) in ARPE-19 cells. TGF-ß1 induced survivin expression, which in turn stabilized tubulin and Aurora B. RT-PCR and western blot analysis revealed that survivin expression increased in ARPE-19 cells following TGF-ß1 treatment. When survivin was depleted, TGF-ß1 induced cell cycle arrest and apoptosis and also reduced Rb phosphorylation. In conclusion, the present study shows that induction of EMT in human RPE cells upregulates survivin, leading to survivin-dependent inhibition of cell cycle arrest and apoptosis. Whether cells undergo EMT or apoptosis in response to TGF-ß1 is dependent on their cell cycle state, and TGF-ß1 regulates the cell cycle via survivin.


Subject(s)
Epithelial-Mesenchymal Transition , Inhibitor of Apoptosis Proteins/genetics , Transcriptional Activation , Transforming Growth Factor beta1/physiology , Apoptosis , Aurora Kinase B/metabolism , Cell Line, Tumor , Cell Survival , Humans , Inhibitor of Apoptosis Proteins/metabolism , Mitosis , Phosphatidylinositol 3-Kinases/metabolism , Protein Stability , Retinal Pigment Epithelium/physiology , Survivin , Tubulin/metabolism , Up-Regulation
5.
Phys Rev Lett ; 109(13): 132002, 2012 Sep 28.
Article in English | MEDLINE | ID: mdl-23030084

ABSTRACT

The Θ(+) pentaquark baryon was searched for via the π(-)p→K(-)X reaction with a missing mass resolution of 1.4 MeV/c(2) (FWHM) at the Japan Proton Accelerator Research Complex (J-PARC). π(-) meson beams were incident on the liquid hydrogen target with a beam momentum of 1.92 GeV/c. No peak structure corresponding to the Θ(+) mass was observed. The upper limit of the production cross section averaged over the scattering angle of 2° to 15° in the laboratory frame is obtained to be 0.26 µb/sr in the mass region of 1.51-1.55 GeV/c(2). The upper limit of the Θ(+) decay width is obtained to be 0.72 and 3.1 MeV for J(Θ)(P)=1/2(+) and J(Θ)(P)=1/2(-), respectively, using the effective Lagrangian approach.

6.
J Med Primatol ; 40(5): 300-9, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21463330

ABSTRACT

BACKGROUND: Simian immunodeficiency virus (SIV) infection and persistent CD8(+) lymphocyte depletion rapidly leads to encephalitis and neuronal injury. The objective of this study is to confirm that CD8 depletion alone does not induce brain lesions in the absence of SIV infection. METHODS: Four rhesus macaques were monitored by proton magnetic resonance spectroscopy ((1) H-MRS) before and biweekly after anti-CD8 antibody treatment for 8 weeks and compared with four SIV-infected animals. Post-mortem immunohistochemistry was performed on these eight animals and compared with six uninfected, non-CD8-depleted controls. RESULTS: CD8-depleted animals showed stable metabolite levels and revealed no neuronal injury, astrogliosis or microglial activation in contrast to SIV-infected animals. CONCLUSIONS: Alterations observed in MRS and lesions in this accelerated model of neuroAIDS result from unrestricted viral expansion in the setting of immunodeficiency rather than from CD8(+) lymphocyte depletion alone.


Subject(s)
Brain/pathology , CD8-Positive T-Lymphocytes/pathology , Lymphocyte Depletion/veterinary , Macaca mulatta , Simian Acquired Immunodeficiency Syndrome/pathology , Animals , Antibodies, Monoclonal/metabolism , Astrocytes/metabolism , Astrocytes/pathology , Astrocytes/virology , Brain/metabolism , Brain/virology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/virology , Disease Models, Animal , Encephalitis, Viral/immunology , Encephalitis, Viral/metabolism , Encephalitis, Viral/pathology , Encephalitis, Viral/veterinary , Flow Cytometry/veterinary , Glial Fibrillary Acidic Protein/metabolism , Immunohistochemistry/veterinary , Magnetic Resonance Spectroscopy , Microfilament Proteins/metabolism , Microglia/metabolism , Microglia/pathology , Microglia/virology , Microtubule-Associated Proteins/metabolism , Monkey Diseases/immunology , Monkey Diseases/pathology , Monkey Diseases/virology , Neurons/metabolism , Neurons/pathology , Neurons/virology , Protons , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/physiology , Synaptophysin/metabolism
7.
Clin Exp Immunol ; 164(2): 275-81, 2011 May.
Article in English | MEDLINE | ID: mdl-21391988

ABSTRACT

Allergic conjunctivitis from an allergen-driven T helper type 2 (Th2) response is characterized by conjunctival eosinophilic infiltration. Association between signalling through Toll-like receptor 4 (TLR-4) and adaptive immune responses has been observed in allergic airway disease. We examined whether administration of bacterial lipopolysaccharide (LPS), a prototypic bacterial product that activates immune cells via TLR-4, could affect the development of allergic conjunctivitis and modify the immune response to ovalbumin (OVA) allergen in an experimental allergic conjunctivitis (EAC) model. Mice were challenged with two doses of OVA via conjunctival sac after systemic challenge with OVA in alum. Several indicators for allergy were evaluated in wild-type and TLR-4(-/-) mice with or without adding of different doses of LPS into OVA in alum. Mice challenged with OVA via conjunctival sac following systemic challenge with OVA in alum had severe allergic conjunctivitis. Of interest, LPS administration markedly suppressed immunoglobulin (Ig)E-mediated and eosinophil-dependent conjunctival inflammation. In addition, mice sensitized with OVA plus LPS had less interleukin (IL)-4, IL-5 and eotaxin secretion than mice sensitized with OVA only. The suppression of allergic response by LPS administration was due to Th1 shift. In contrast, the presence of LPS during sensitization with OVA had no effect on severity of allergic conjunctivitis and Th2 responses in TLR4-4(-/-) mice. Our findings demonstrate, for the first time, that LPS suppresses Th2 responses via the TLR-4-dependent pathway in the EAC model.


Subject(s)
Conjunctivitis, Allergic/immunology , Th2 Cells/immunology , Toll-Like Receptor 4/physiology , Administration, Topical , Allergens/immunology , Allergens/toxicity , Animals , Cells, Cultured/immunology , Chemokine CCL11 , Disease Models, Animal , Female , Immunoglobulin E/immunology , Injections, Intraperitoneal , Interleukin-4 , Interleukin-5 , Lipopolysaccharides/toxicity , Mice , Mice, Inbred BALB C , Mice, Knockout , Models, Immunological , Ovalbumin/toxicity , Specific Pathogen-Free Organisms , Th1 Cells/immunology , Toll-Like Receptor 4/deficiency
8.
Solid State Electron ; 54(10): 1185-1191, 2010 Oct 01.
Article in English | MEDLINE | ID: mdl-20711489

ABSTRACT

One-dimensional nanostructures such as silicon nanowires (SiNW) are attractive candidates for low power density electronic and optoelectronic devices including sensors. A new simple method for SiNW bulk synthesis[1, 2] is demonstrated in this work, which is inexpensive and uses low toxicity materials, thereby offering a safe, energy efficient and green approach. The method uses low flammability liquid phenylsilanes, offering a safer avenue for SiNW growth compared with using silane gas. A novel, duo-chamber glass vessel is used to create a low-pressure environment where SiNWs are grown through vapor-liquid-solid mechanism using gold nanoparticles as a catalyst. The catalyst decomposes silicon precursor vapors of diphenylsilane and triphenylsilane and precipitates single crystal SiNWs, which appear to grow parallel to the substrate surface. This opens up possibilities for synthesizing nano-junctions amongst wires which is important for the grid architecture of nanoelectronics proposed by Likharev[3]. Even bulk synthesis of SiNW is feasible using sacrificial substrates such as CaCO(3) that can be dissolved post-synthesis. Furthermore, by dissolving appropriate dopants in liquid diphenylsilane, a controlled doping of the nanowires is realized without the use of toxic gases and expensive mass flow controllers. Upon boron doping, we observe a characteristic red shift in photoluminescence spectra. In summary, an inexpensive and versatile method for SiNW is presented that makes these exotic materials available to any lab at low cost.

9.
J Environ Sci (China) ; 21(1): 23-9, 2009.
Article in English | MEDLINE | ID: mdl-19402395

ABSTRACT

In this study, chlorine decay experiments were conducted for the raw water from Nakdong River that is treated by Chilseo Water Treatment Plant (CWTP) situated in Haman, Korea as well as the effluents from sand and granular activated carbon (GAC) filters of CWTP and fitted using a chlorine decay model. The model estimated the fast and slow reacting nitrogenous as well as organic/inorganic compounds that were present in the water. It was found that the chlorine demand due to fast and slow reacting (FRA and SRA) organic/inorganic substances was not reduced significantly by sand as well as GAC filters. However, the treated effluents from those filters contained FRA and SRA that are less reactive and had small reaction rate constants. For the effluents from microfiltration, ultrafiltration, and nanofiltration the chlorine demand because FRA and SRA were further reduced but the reaction rate constants were larger compared to those of sand and GAC filter effluents. This has implications in the formation of disinfection by products (DBPs). If DBPs are assumed to form due to the interactions between chlorine and SRA, then it is possible that the DBP formation potential in the effluents from membrane filtrations could be higher than that in the effluents from granular media filters.


Subject(s)
Chlorine/chemistry , Chlorine/isolation & purification , Drinking , Filtration/methods , Membranes, Artificial , Water Purification , Water Supply , Carbon/chemistry , Chlorine/supply & distribution , Disinfectants/chemistry , Disinfection , Kinetics , Models, Chemical , Nanotechnology , Osmosis , Rivers/chemistry
10.
Eye (Lond) ; 23(4): 895-903, 2009 Apr.
Article in English | MEDLINE | ID: mdl-18464802

ABSTRACT

PURPOSE: To investigate the possibility of collagen type VIII alpha2 (COL8A2) as a potential susceptibility gene for Korean patients with Fuchs' corneal dystrophy (FECD), we performed mutation screening of the COL8A2 gene. METHODS: A total of 25 FECD patients were screened, including 15 patients from six pedigrees with early onset FECD and an additional 10 unrelated patients, all of Korean ancestry. Seventy-three control individuals without corneal disease were selected from the general population. PCR-SSCP and direct sequencing were used to screen genetic variations in COL8A2. The pathogenic impact of these sequence variants was evaluated through the SIFT and PolyPhen algorithms. RESULTS: We have identified a novel heterozygous mutation, Q455V, in exon 2 of COL8A2. All patients of Korean pedigrees with FECD had the Q455V mutation, and two out of nine unrelated cases also had this mutation. But it was not present in unaffected individuals from these pedigrees or from control groups. Two heterozygous missense mutations, R155Q and T502M, were also observed, but, they showed no significant difference between FECD patients and controls. The allele frequencies of A35A and G495G, which were synonymous substitutions, were significantly associated with FECD. Both Q455V and T502M were predicted as deleterious mutations by computational methods using PolyPhen and SIFT. CONCLUSIONS: Our data constitute the first report of a heterozygous Q455V mutation of the COL8A2 gene in Korean patients with FECD. Q455V may be the causative defect in the development and progression of Korean FECD patients.


Subject(s)
Asian People/genetics , Collagen Type VIII/genetics , Fuchs' Endothelial Dystrophy/genetics , Mutation , Adult , Aged , Aged, 80 and over , Alleles , Amino Acid Substitution , DNA Mutational Analysis , Exons , Female , Fuchs' Endothelial Dystrophy/pathology , Gene Frequency , Humans , Korea , Male , Middle Aged , Pedigree , Polymerase Chain Reaction/methods , Young Adult
11.
Mol Vis ; 14: 2109-16, 2008.
Article in English | MEDLINE | ID: mdl-19043479

ABSTRACT

PURPOSE: To investigate the genetic association between unrelated Korean keratoconus patients and interleukin 1 alpha (IL1A), interleukin 1 beta (IL1B), and IL1 receptor antagonist (IL1RN) gene polymorphisms. METHODS: We investigated the association between IL1A (rs1800587, rs2071376, and rs17561), IL1B (rs1143627, rs16944, rs1143634, and rs1143633), and IL1RN (rs419598, rs423904, rs424078, and rs315952, variable number tandem repeat [VNTR]) polymorphisms in 100 unrelated Korean keratoconus patients. One hundred control individuals without any corneal disease were selected from the general population. Polymerase chain reaction (PCR) - restriction fragment length polymorphism (RFLP) analysis and direct sequencing were used to screen for genetic variations in the IL1 gene cluster. Haplotypes for the IL1 gene cluster were constructed using Haploview version 4.0. RESULTS: We analyzed a total of 12 polymorphic sites in the IL1 gene cluster. Among them, the -511 (rs16944) and -31 (rs1143627) positions in the promoter region of IL1B were significantly different between patient and control groups. The C allele of rs16944 (-511C>T, p=0.022, odds ratio of risk [OR]=1.46, 95% confidence intervals [CI] 0.94<2.27) and the T allele of rs1143627 (-31T>C, p=0.025, OR=1.43, 95% CI 0.92<2.22) were associated with a significantly increased risk of keratoconus in Korean patients. Linkage of the two alleles, -31*C and -511*T, was associated with an increased risk for keratoconus with OR=2.38 (p=0.012, 95% CI=1.116-5.046). The *C/*A genotype of rs2071376 in IL1A intron 6 was significantly different between the keratoconus patients and control subjects (p=0.034, OR=0.59, 95% CI 0.32<1.11). Other polymorphisms did not show an association with keratoconus risk. CONCLUSIONS: This is the first report of IL1 gene cluster mutation screening in Korean keratoconus patients. Significant differences in allelic frequency of IL1B between keratoconus patients and the control group suggest that IL1B polymorphisms may play a role in the susceptibility of unrelated Koreans to develop keratoconus.


Subject(s)
Asian People/genetics , Genetic Predisposition to Disease , Interleukin-1beta/genetics , Keratoconus/genetics , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , Haplotypes , Humans , Linkage Disequilibrium/genetics
12.
Opt Express ; 16(22): 17186-95, 2008 Oct 27.
Article in English | MEDLINE | ID: mdl-18957999

ABSTRACT

Spectral-domain optical coherence phase microscopy (SD-OCPM) measures minute phase changes in transparent biological specimens using a common path interferometer and a spectrometer based optical coherence tomography system. The Fourier transform of the acquired interference spectrum in spectral-domain optical coherence tomography (SD-OCT) is complex and the phase is affected by contributions from inherent random noise. To reduce this phase noise, knowledge of the probability density function (PDF) of data becomes essential. In the present work, the intensity and phase PDFs of the complex interference signal are theoretically derived and the optical path length (OPL) PDF is experimentally validated. The full knowledge of the PDFs is exploited for optimal estimation (Maximum Likelihood estimation) of the intensity, phase, and signal-to-noise ratio (SNR) in SD-OCPM. Maximum likelihood (ML) estimates of the intensity, SNR, and OPL images are presented for two different scan modes using Bovine Pulmonary Artery Endothelial (BPAE) cells. To investigate the phase accuracy of SD-OCPM, we experimentally calculate and compare the cumulative distribution functions (CDFs) of the OPL standard deviation and the square root of the Cramér-Rao lower bound (1/ square root 2SNR ) over 100 BPAE images for two different scan modes. The correction to the OPL measurement by applying ML estimation to SD-OCPM for BPAE cells is demonstrated.

13.
Hum Exp Toxicol ; 27(5): 401-7, 2008 May.
Article in English | MEDLINE | ID: mdl-18715886

ABSTRACT

We made gene therapeutics for X-chronic granulomatous disease (CGD) by transducing murine bone marrow-derived stem cells with MT-gp91 retrovirus and evaluated possible toxicity in mice as a prerequisite for human clinical trials. Male C57BL/6 mice were injected intravenously with gene therapeutics for X-CGD twice at an interval of two weeks at 5 x 10(7) cells/kg and sacrificed 2 weeks after the last administration. Significant changes noted in gene therapeutics for X-CGD-treated animals were an increase in white blood cell counts and a slight decrease in albumin/globulin ratio. The red pulp hyperplasia in the spleen accompanied with an increase in organ weight was considered to result from the accumulation of gene therapeutics for X-CGD, bone marrow-derived stem cells, in the spleen. No anti-gp91 antibody was detected in the sera collected from the animals treated with gene therapeutics for X-CGD. No integration of gp91 DNA from retroviral vector was detected in chromosomal DNA of gonads in animals dosed with the test substance, indicating no potential of genomic integration. In conclusion, the repeated dose of gene therapeutics for X-CGD exerted no toxicity. The splenic red pulp hyperplasia and the increase observed in white blood cell counts and in spleen weights were considered as pharmacological changes induced by the treatment.


Subject(s)
Genetic Therapy/adverse effects , Genetic Vectors/adverse effects , Granulomatous Disease, Chronic/genetics , Granulomatous Disease, Chronic/therapy , Animals , Bone Marrow Cells/drug effects , Bone Marrow Cells/pathology , Disease Models, Animal , Genetic Therapy/methods , Hyperplasia/chemically induced , Hyperplasia/pathology , Injections, Intravenous , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Organ Size/drug effects , Retroviridae/genetics , Spleen/drug effects , Spleen/pathology
14.
Eur J Ophthalmol ; 18(3): 377-83, 2008.
Article in English | MEDLINE | ID: mdl-18465720

ABSTRACT

PURPOSE: To compare the clinical results of heparin surface modified (HSM) hydrophilic acrylic intraocular lens (IOL) with those of hydrophobic acrylic IOL. METHODS: One hundred patients with cataract were randomized to receive one of acrylic foldable IOLs after phacoemulsification: HSM hydrophilic acrylic IOL (n=50) BioVue3 (BioVue, OII, Ontario, CA, USA) and hydrophobic acrylic IOL (n=50) Sensar (AR40e, AMO, Santa Ana, CA, USA). Bestcorrected visual acuity and refractive error were measured at 1 week, 2 months, 6 months and 12 months after surgery in both IOL groups. To assess posterior capsular opacification (PCO), digital retroillumination image of posterior capsule was analyzed at 12 months using POCOman software. RESULTS: Best-corrected visual acuity (log MAR) was 0.032+/-0.082 in BioVue3 group and 0.034+/-0.077 in Sensar group at 12 months. There was no statistically significant difference between the two groups (p=0.554). Refractive error was -0.247+/-0.821 diopter in BioVue3 group and -0.264+/-0.808 diopter in Sensar group at 12 months. There was no statistically significant difference of refractive error between the two groups (p=0.909). At 12 months, BioVue3 IOL group had a lower percentage area and severity of PCO than Sensar group. However, it was not statistically significant (p=0.349, p=0.288). No Nd:YAG capsulotomy was performed in BioVue3 group while it was required in two eyes (4.0%) in Sensar group. CONCLUSIONS: There was no statistically significant difference of postoperative visual acuity, refractive error and degree of PCO between HSM hydrophilic acrylic IOL and hydrophobic acrylic IOL.


Subject(s)
Acrylic Resins , Coated Materials, Biocompatible , Heparin , Lens Implantation, Intraocular , Lenses, Intraocular , Visual Acuity/physiology , Adult , Aged , Aged, 80 and over , Cataract/pathology , Female , Follow-Up Studies , Humans , Lens Capsule, Crystalline/pathology , Male , Middle Aged , Phacoemulsification , Postoperative Complications , Prospective Studies , Refractive Errors/physiopathology
15.
Appl Magn Reson ; 34(3-4): 237-263, 2008 Aug.
Article in English | MEDLINE | ID: mdl-19194532

ABSTRACT

Dynamic nuclear polarization (DNP) results in a substantial nuclear polarization enhancement through a transfer of the magnetization from electrons to nuclei. Recent years have seen considerable progress in the development of DNP experiments directed towards enhancing sensitivity in biological nuclear magnetic resonance (NMR). This review covers the applications, hardware, polarizing agents, and theoretical descriptions that were developed at the Francis Bitter Magnet Laboratory at Massachusetts Institute of Technology for high-field DNP experiments. In frozen dielectrics, the enhanced nuclear polarization developed in the vicinity of the polarizing agent can be efficiently dispersed to the bulk of the sample via (1)H spin diffusion. This strategy has been proven effective in polarizing biologically interesting systems, such as nanocrystalline peptides and membrane proteins, without leading to paramagnetic broadening of the NMR signals. Gyrotrons have been used as a source of high-power (5-10 W) microwaves up to 460 GHz as required for the DNP experiments. Other hardware has also been developed allowing in situ microwave irradiation integrated with cryogenic magic-angle-spinning solid-state NMR. Advances in the quantum mechanical treatment are successful in describing the mechanism by which new biradical polarizing agents yield larger enhancements at higher magnetic fields. Finally, pulsed methods and solution experiments should play a prominent role in the future of DNP.

16.
Oncogene ; 27(5): 614-28, 2008 Jan 24.
Article in English | MEDLINE | ID: mdl-17637750

ABSTRACT

Many of the signaling responses induced by transforming growth factor-beta (TGF-beta) are mediated by Smad proteins, but there is evidence that it can also signal independently of Smads. Here, we provide evidence that multiple signal pathways induced by TGF-beta1-including Src family tyrosine kinases (SFKs), generation of reactive oxygen species (ROS), de novo protein synthesis and E-cadherin-dependent cell-cell interactions-transactivate the epidermal growth factor receptor (EGFR), which in turn regulates expression of c-Fos and c-Jun. Immunoprecipitation and immunofluorescence staining showed that EGFR was phosphorylated on tyrosine in response to TGF-beta1. EGFR transactivation required the activation of SFKs and the production of ROS via NADPH oxidase, but was not dependent on metalloproteases or the release of EGF-like ligands. In addition, the production of ROS was dependent on signaling by specific SFKs as well as de novo protein synthesis. Stable transfection of E-cadherin into MDA-MB-231 cells as well as E-cadherin-blocking assays revealed that E-cadherin-mediated cell-cell interactions were also essential for EGFR transactivation. Finally, EGFR transactivation was involved in the expression of c-Fos and c-Jun via the extracellular signal-regulated kinase signaling cascade. Taken together our data suggest that ligand release-independent transactivation of EGFR may diversify early TGF-beta signaling and represent a novel pathway leading to TGF-beta-mediated gene expression.


Subject(s)
ErbB Receptors/metabolism , Transforming Growth Factor beta1/physiology , src-Family Kinases/metabolism , Cadherins/metabolism , Cells, Cultured , Humans , Keratinocytes , Ligands , Protein Biosynthesis , Reactive Oxygen Species/metabolism , Signal Transduction , Transcriptional Activation , Transfection
17.
Water Sci Technol ; 46(6-7): 255-61, 2002.
Article in English | MEDLINE | ID: mdl-12380999

ABSTRACT

To predict daily water demand for Seoul, Korea, the artificial neural network (ANN) was used. For the cross correlation, the factors affecting water demand such as maximum temperature, humidity, and wind speed as natural factors, holidays as a social factor and daily demand 1 day before were used. From the results of learning using various hidden layers and units in order to establish the structure of optimal ANN, the case of 3 hidden layers and numbers of unit with the same number of input factors showed the best result and, therefore, it was applied to seasonal water demand prediction. The performance of ANN was compared with a multiple regression method. We discuss the representation ability of the model building process and the applicability of the ANN approach for the daily water demand prediction. ANN provided reasonable results for time series prediction.


Subject(s)
Models, Theoretical , Neural Networks, Computer , Water Supply , Forecasting , Humidity , Korea , Regression Analysis , Seasons , Temperature
19.
Ophthalmic Res ; 33(6): 329-35, 2001.
Article in English | MEDLINE | ID: mdl-11721185

ABSTRACT

We investigated the kinetics of multiple cytokines and inducible nitric oxide synthase (iNOS) in experimental uveitis induced by bovine melanin protein (BMP) for the proper treatment of uveitis. Experimental uveitis was induced in male Lewis rats by injection of BMP. The levels of various inflammatory cytokines and iNOS mRNAs were semiquantified by the reverse-transcriptase reaction followed by PCR. The uveitis was started to develop at approximately day 14 and peaked around 21 days after immunization. The signs of uveitis disappeared by 4 weeks after immunization. When the inflammation was severest, TNF-alpha, IL-1alpha, IL-10, IFN-gamma and iNOS mRNA increased to their peak, which varied with the degree of induction and different time course. We concluded that both cytokines and iNOS might modulate the inflammation at different states of experimental melanin-protein-induced uveitis. Their combination will be necessary for an effective treatment of inflammation.


Subject(s)
Ciliary Body/metabolism , Cytokines/genetics , Iris/metabolism , Nitric Oxide Synthase/genetics , Uveitis, Anterior/metabolism , Animals , Cattle , Ciliary Body/pathology , Cytokines/metabolism , DNA Primers/chemistry , Disease Models, Animal , Iris/pathology , Male , Melanins , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type II , RNA, Messenger/metabolism , Rats , Rats, Inbred Lew , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , Uveitis, Anterior/chemically induced , Uveitis, Anterior/pathology
20.
Neurobiol Dis ; 8(5): 774-83, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11592847

ABSTRACT

Synaptically released Zn2+ ions enter into neurons primarily through voltage-gated Ca2+ channels (VGCC) or N-methyl-d-aspartate (NMDA) receptors, which can mediate pathological neuronal death. We studied the possibility (and underlying mechanisms) that aspirin, known to prevent NMDA neurotoxicity, would also attenuate Zn2+ neurotoxicity. Administration of 3 to 10 mM aspirin, in cortical cell cultures, attenuated the evolution of neuronal death following exposure to 300 microM Zn2+ for 30 min. This neuroprotective effect of aspirin was attributable to the prevention of Zn2+ ion entry. Aspirin interfered with inward currents and an increase in [Ca2+]i through VGCC and selective binding of omega-conotoxin, sensitive to N-type Ca2+ channel. The omega-conotoxins GVIA or MVIIC, the selective inhibitors of N-type Ca2+ channels, attenuated Zn2+ neurotoxicity. Aspirin derivatives lacking the carboxyl acid group did not reduce Zn2+ neurotoxicity. The present findings suggest that aspirin prevents Zn2+-mediated neuronal death by interfering with VGCC, and its action specifically requires the carboxyl acid group.


Subject(s)
Apoptosis/drug effects , Aspirin/pharmacology , Calcium Channels, N-Type/physiology , Ion Transport/drug effects , Nerve Tissue Proteins/physiology , Neurons/drug effects , Neuroprotective Agents/pharmacology , Zinc/toxicity , Acetylcysteine/pharmacology , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antioxidants/pharmacology , Aspirin/analogs & derivatives , Aspirin/chemistry , Benzoates/pharmacology , Calcium/metabolism , Calcium Channels, N-Type/drug effects , Cerebral Cortex/cytology , Cerebral Cortex/drug effects , Chromans/pharmacology , Excitatory Amino Acid Agonists/pharmacology , Ion Channel Gating/drug effects , Membrane Potentials/drug effects , Mice , N-Methylaspartate/pharmacology , Nerve Tissue Proteins/drug effects , Neurons/metabolism , Staurosporine/pharmacology , Structure-Activity Relationship , Zinc/antagonists & inhibitors , Zinc/pharmacology , omega-Conotoxin GVIA/pharmacology , omega-Conotoxins/pharmacology
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