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Mizukami K, Ito T, Saeki S, Zhang Q, Saito F, Ryu H. Computer Simulation Study on the Interaction Between a PVC Model Molecule and Ca(OH)2 Excited Under Mechanical Force. Chem Eng Res Des 2004. [DOI: 10.1205/cerd.82.9.1112.44167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Notomi M, Shinya A, Mitsugi S, Kuramochi E, Ryu H. Waveguides, resonators and their coupled elements in photonic crystal slabs. OPTICS EXPRESS 2004; 12:1551-61. [PMID: 19474980 DOI: 10.1364/opex.12.001551] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The design, fabrication, and measurement of photonic-band-gap (PBG) waveguides, resonators and their coupled elements in two-dimensional photonic crystal (PhC) slabs have been investigated. We have studied various loss mechanisms in PBG waveguides and have achieved a very low propagation loss (~1 dB/mm). For these waveguides, we have observed a large group delay (>100 ps) by time-domain measurement. As regards PBG resonators, we realize very high-Q and small volume resonators in PhC slabs by appropriate design. Finally, we demonstrate various forms of coupled elements of waveguides and resonators: 2-port resonant-tunneling transmission devices, 4-port channel-drop devices using the slow light mode, and 3-port channel-drop devices using the resonant-tunneling process.
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Sasikumar G, Ryu H. Comparison of Electrode Backing Materials for Polymer Electrolyte Membrane Fuel Cells. JOURNAL OF THE KOREAN ELECTROCHEMICAL SOCIETY 2003. [DOI: 10.5229/jkes.2003.6.3.183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lee MS, Yang KH, Huh HJ, Kim HW, Ryu H, Lee HS, Chung HT. Qi therapy as an intervention to reduce chronic pain and to enhance mood in elderly subjects: a pilot study. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2002; 29:237-45. [PMID: 11527067 DOI: 10.1142/s0192415x01000277] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Qi therapy (or external Qi) is an oriental complementary therapy preventing, curing disease and strengthens health and improving the human potentiality through regulation of body. It is increasingly being used to improve the quality of life, but there is little direct evidence of its efficacy. This study assessed the effects of Qi therapy (QT) on reducing pain and enhancing mood states in elderly subjects with chronic pain. We studied 40 elderly participants with chronic pain, who were randomly allocated to receive QT (n=20) or standard care (n=20). The experimental group receives Qi therapy twice a week for 2 weeks (total 4 times), and control group received general care at the same time and the same amount of duration. We measured pain level and Profile of Mood State (POMS) to explore participants' response to Qi therapy. There was a significant reduction in pain (p<0.0001) after QT and an improved positive mood state (p<0.0001). These findings suggest that Qi therapy may have a role in helping the elderly to cope with their pain and mood disturbances.
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Ryu H, Young WB, Park C. Korean American health insurance and health services utilization. Res Nurs Health 2001; 24:494-505. [PMID: 11746078 DOI: 10.1002/nur.10009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The purpose of this ethnic group study was to describe the unique pattern of Korean Americans, as compared with the aggregate of Asian Americans, for: (a) the predisposing, enabling, and need factors for health service utilization, focusing specifically on the role of health insurance coverage; and (b) predictors of health insurance coverage. Using the behavioral model for health service utilization, data were selected from the 1992 National Health Insurance Survey (NHIS, 1994) for Korean Americans (n = 345) and Asian Americans (n = 3,059). Results differed between the Korean American group and the Asian American group. Health insurance coverage was the strongest predictor of Korean American utilization, and need factors lacked significance, suggesting that uninsured Korean Americans have less access regardless of need. For the aggregate Asian American group, need factors tempered the influence of health insurance on utilization. Results of this type of study may be helpful for designing and implementing health care services tailored for specific ethnic at-risk markets.
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Ryu H, Morita K, Shoji Y, Waseda Y, Maeda H. Abnormal exploratory eye movements in schizophrenic patients vs healthy subjects. Acta Neurol Scand 2001; 104:369-76. [PMID: 11903092 DOI: 10.1034/j.1600-0404.2001.00279.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We examined previously described exploratory eye movements abnormalities as biologic markers in schizophrenic patients in comparison with age-matched healthy subjects. MATERIAL AND METHODS Using an eye-mark recorder, eye movements were analysed for mean gazing time, total number of gazing points, mean eye scanning length, total eye scanning length, and total gazing times as subjects viewed six simple pictures in preparation for copying them. RESULTS In-patients, and to a lesser extent, out-patients, with schizophrenia showed a longer gazing time, fewer gazing points, a shorter mean and total eye scanning length. and longer gazing time than healthy subjects. In schizophrenic patients. negative symptom scores were positively correlated with mean gazing time (r = 0.33), and negatively correlated with the total number of gazing points (r = -0.29) as well as, the mean (r = -0.40) and total scanning length (r = -0.46). CONCLUSION Exploratory eye movements are a biologic marker useful for evaluation of schizophrenia.
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Lee MS, Huh HJ, Jang HS, Han CS, Ryu H, Chung HT. Effects of emitted Qi on in vitro natural killer cell cytotoxic activity. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2001; 29:17-22. [PMID: 11321475 DOI: 10.1142/s0192415x01000034] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present study investigated the effects of Korean Qi-therapy, ChunSoo Energy Healing, on natural killer (NK) cell cytotoxicity in vitro depending on Qi-treatment time and the types of cells treated. NK cell cytotoxicity was assayed by measuring LDH release from tumor target cells (K562 cell lines). NK activity was significantly increased by emitted-Qi treatment of 30 sec duration. Three and 5 minutes of Qi projection created the greatest increase in NK cell activity when mixtures of NK cells and K562 cells were treated (1.81 and 2.12 fold for 4 hr culture; 1.54 and 1.36 for 16 hr culture, respectively). NK cell activity increased significantly in Qi-treated K562 cells alone (1.13 fold, p<0.05) compared to control. These results are consistent with in vivo Qi-therapy on humans and suggests that emitted-Qi has an acute stimulatory effect on NK cell activity. This study provides direct scientific support that Qi as such may positively affect human cellular immunity.
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Chatterjee S, Zaman K, Ryu H, Conforto A, Ratan RR. Sequence-selective DNA binding drugs mithramycin A and chromomycin A3 are potent inhibitors of neuronal apoptosis induced by oxidative stress and DNA damage in cortical neurons. Ann Neurol 2001; 49:345-54. [PMID: 11261509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Global inhibitors of RNA or protein synthesis such as actinomycin D or cycloheximide abrogate neuronal apoptosis induced by numerous pathological stimuli in vitro and in vivo. The clinical application of actinomycin D or cycloheximide to human neurological disease has been limited by the toxicities of these agents. To overcome these toxicities, strategies must be developed to inhibit selectively the expression of deleterious proapoptotic proteins, while leaving the expression of antiapoptotic, proregeneration, and other critical homeostatic proteins unperturbed. Mithramycin A (trade name Plicamycin) is an aureolic acid antibiotic that has been used in humans to treat hypercalcemia and several types of cancers. This class of agents is believed to act, in part, by selectively inhibiting gene expression by displacing transcriptional activators that bind to G-C-rich regions of promoters. Here we demonstrate that mithramycin A and its structural analog chromomycin A3 are potent inhibitors of neuronal apoptosis induced by glutathione depletion-induced oxidative stress or the DNA-damaging agent camptothecin. We correlate the protective effects of mithramycin A with its ability to inhibit enhanced DNA binding of the transcription factors Sp1 and Sp3 to their cognate "G-C" box induced by oxidative stress or DNA damage. The protective effects of mithramycin A cannot be attributed to global inhibition of protein synthesis. Together, these results suggest that mithramycin A and its structural analogs may be effective agents for the treatment of neurological diseases associated with aberrant activation of apoptosis and highlight the potential use of sequence-selective DNA-binding drugs as neurological therapeutics.
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Ryu SY, Kou NY, Choi HS, Ryu H, Kim TS, Kim KM. Cnidicin, a coumarin, from the root of Angelica koreana, inhibits the degranulation of mast cell and the NO generation in RAW 264.7 cells. PLANTA MEDICA 2001; 67:172-174. [PMID: 11301870 DOI: 10.1055/s-2001-11509] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cnidicin (1) and five related coumarins were isolated from the root extract of Angelica koreana (Umbelliferae) as active principles responsible for the inhibitory effect on the degranulation process of cultured mast cells. Cnidicin (1) demonstrated a significant inhibition upon the release of beta-hexosaminidase from the cultured RBL-2H3 cells in a dose dependent manner (IC50 value, 25 microM) and upon the nitric oxide production from the activated RAW264.7 cells (IC50 value, 7.5 microM). In agreement with this, cnidicin inhibited the expression of nitric oxide synthase in RAW264.7 cells.
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Yamamoto S, Ryu H, Tanaka T, Takehara Y. Usefulness of high-resolution magnetic resonance cisternography in patients with hemifacial spasm. ACTA OTO-LARYNGOLOGICA. SUPPLEMENTUM 2001; 542:54-7. [PMID: 10897401 DOI: 10.1080/000164800454675-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
To analyse the usefulness of preoperative magnetic resonance (MR) cisternography in patients with hemifacial spasm (HFS), MR observations were compared with surgical findings. High-definition images were obtained using MR cisternography which employed a long echo train length, fast spin-echo sequence, which revealed both nerves and blood vessels without any contrast media. In 35 HFS patients, certified radiologists examined the presence of vascular compression of the facial nerve and identified the offending vessels. MR cisternography depicted neurovascular compression in 31 patients (sensitivity 88.6%) and correctly determined the offending vessels in 28 patients. In 4 patients, MR cisternography revealed the presence of the vessel near the facial nerve, but the radiologist evaluated the compression as questionable (false-negative rate 11.4%). Even in these patients, MR cisternography revealed the precise anatomy of cerebellopontine (CP) cistern. High-resolution MR cisternography is useful in identifying the vessels and nerve bundles in the CP cistern, and in so doing can provide surgeons with valuable information regarding neurovascular decompression for HFS.
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Ryu H, Kim YS, Grange PA, Cassels FJ. Escherichia coli strain RDEC-1 AF/R1 endogenous fimbrial glycoconjugate receptor molecules in rabbit small intestine. Infect Immun 2001; 69:640-9. [PMID: 11159950 PMCID: PMC97934 DOI: 10.1128/iai.69.2.640-649.2001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Escherichia coli strain RDEC-1 causes a diarrheagenic infection in rabbits with AF/R1 fimbriae, which have been identified as an important colonization factor in RDEC-1 adherence leading to disease. The AF/R1-mediated RDEC-1 adherence model has been used as a model systems for E. coli diarrheal diseases. In this study, RDEC-1 adhered specifically to small intestinal brush borders, with both sialic acid and beta-galactosyl residues apparently involved. The AF/R1-mediated adherence activity of [(14)C]-labeled RDEC-1 was analyzed quantitatively by using 24-well plates coated with purified brush borders and purified microvilli. Two microvillus membrane proteins (130 and 140 kDa) were individually isolated, and chicken antibody raised to each protein inhibited bacterial adherence. These same two proteins, previously shown to be recognized by AF/R1, were individually digested with trypsin, and the amino acid sequences of peptides were determined by reversed-phase capillary liquid chromatography-mass spectrometry tandem mass spectrometry (LC-MS). This LC-MS analysis indicated that these proteins are subunits of the rabbit sucrase-isomaltase protein (SI) complex. Guinea pig serum raised to purified rabbit SI complex inhibited bacterial adherence to microvilli. Additionally, as determined by high-performance thin-layer chromatography and autoradiography, RDEC-1 adhered selectively, via AF/R1 fimbriae, to a glycolipid tentatively identified as galactosylceramide (Gal beta 1-1Cer) in the lipid extract of rabbit small intestinal brush borders. RDEC-1 adherence to Gal beta 1-1Cer was partially inhibited in the presence of galactose. These combined results indicate that the endogenous receptor molecule for AF/R1 fimbriae of RDEC-1 is each individual component of the SI complex, although binding to glycolipid may be responsible for an additional adherence mechanism.
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Ryu H, Lee JH, Kim KS, Jeong SM, Kim PH, Chung HT. Regulation of neutrophil adhesion by pituitary growth hormone accompanies tyrosine phosphorylation of Jak2, p125FAK, and paxillin. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:2116-23. [PMID: 10925297 DOI: 10.4049/jimmunol.165.4.2116] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neutrophil adhesion is fundamentally important during the onset of inflammatory responses. The adhesion signaling pathways control neutrophil arrest and extravasation and influence neutrophil shape and function at sites of inflammation. In the present study the intracellular signaling pathways for the adhesion of human neutrophils by pituitary growth hormone (GH) were examined. Pituitary GH triggered the tyrosine phosphorylation of Janus kinase 2 (Jak2) and STAT3 in neutrophils. In addition, pituitary GH treatment resulted in the morphological changes and the tyrosine phosphorylation of focal adhesion kinase (p125FAK) and paxillin. Preincubation with genistein, a tyrosine kinase inhibitor, blocked the GH-stimulated adhesion and Jak2, STAT3, p125FAK, and paxillin phosphorylation. Confocal microscopy revealed that pituitary GH stimulates the focal localization of p125FAK, paxillin, phosphotyrosine, and filamentous actin filament into the membrane rufflings and uropods of human neutrophils. Immunoprecipitation experiments revealed a physical association of Jak2 with p125FAK via STAT3 in vivo. Also an in vitro kinase assay showed an augmentation of p125FAK autophosphorylation as a result of pituitary GH treatment. These results suggest that pituitary GH modulates neutrophil adhesion through tyrosine phosphorylation of Jak2, p125FAK, and paxillin and actin polymerization.
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Chun M, Kang S, Ryu H, Chang K, Oh Y, Ju H, Lee E. Modified partial hyperfractionation in radiotherapy for bulky uterine cervical cancer: reduction of overall treatment time. Int J Radiat Oncol Biol Phys 2000; 47:973-7. [PMID: 10863067 DOI: 10.1016/s0360-3016(00)00539-3] [Citation(s) in RCA: 11] [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
PURPOSE The purpose of this study was to assess the feasibility and toxicity of modified fractionation of external beam radiation with the intention of reducing the overall treatment time (OT) by 1 week in cervical cancer. METHODS AND MATERIALS Thirty-one patients (Group 1, n = 31) with bulky cervical cancer (>/= 4 cm with Stage II and III, >/= 5 cm with Stage IB2) were entered into the twice a day (b.i. d.) protocol (18 Gy/10 fx in 2 weeks followed by 18 Gy/12 fx, b.i.d. in 6 days, then midline block at 36 Gy with 45 Gy to the whole pelvis and 51-59 Gy to the parametrium). These patients underwent high-dose-rate brachytherapy with 4 Gy/fx x 7 to point A, biweekly. During the same period, patients with non-bulky tumors (Group 2, n = 31) received conventional treatment and similar brachytherapy. RESULTS The OT of Group 1 was 7 weeks or less in 61.3%, 7.1-8 weeks in 29%, and more than 8 weeks in 9.7% (19.4%, 51.6%, and 29% in Group 2, respectively, p = 0.003). Incidences of acute complications and treatment breaks were similar in both groups. Late complication (rectal bleeding) occurred only in Group 1 (13%, 4/31), but was self-limited. Locoregional failures occurred within 2 years after completion of radiation therapy in both groups (16% and 13% in Group 1 and 2, respectively, with minimum and median follow-ups of 2 years and 34 months). CONCLUSION Partial hyperfractionation on the third week of radiation permitted patients to finish their treatment with shorter OT without excessive acute complications and with acceptable grade 2 late rectal bleeding complications. This treatment scheme may be an effective method for the improvement of local control of bulky cervical cancer.
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Ryu H, Lee MS, Jeong SM, Lee JH, Kang CW, Lee DY, Chung HT. Modulation of neuroendocrinological function by psychosomatic training: acute effect of ChunDoSunBup Qi-training on growth hormone, insulin-like growth factor (IGF)-I, and insulin-like growth factor binding protein (IGFBP)-3 in men. Psychoneuroendocrinology 2000; 25:439-51. [PMID: 10818279 DOI: 10.1016/s0306-4530(99)00069-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The neuroendocrine system is regarded as the major link between the psychological state and the immune system in man. The present study was undertaken to examine the acute effect of ChunDoSunBup Qi-training, a traditional psychosomatic training, on the plasma level of growth hormone (GH), insulin-like growth factor (IGF)-I and insulin like growth factor binding protein (IGFBP)-3 in young men. To characterize the plasma level of hormones and the pattern of IGFBP-3 at pre- (-10 min), mid-time (40 min), and immediately after (post-time, +10 min) Qi-training, radioimmunoassay (RIA) and western ligand blot (WLB) analysis were used. The plasma level of GH at the mid-time was significantly increased (P<0.05) compared to the level at pre-time of Qi-training. The plasma level of IGF-I was also increased at mid-time (P<0.05) and immediately after Qi-training. There was a significant correlation between the levels of GH and IGF-I immediately after Qi-training (r=0.69, P<0.01). In this study, the change of IGFBP-3 among the several IGFBPs was determined. There was a relative shift in IGFBP-3 for the 43-kDa fraction during mid-time of Qi-training (P<0.05). These results suggest that Qi-training influences the growth hormone, IGF-I and IGFBP-3 status via brain-target organ axis in men.
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Lee MS, Kim BG, Huh HJ, Ryu H, Lee HS, Chung HT. Effect of Qi-training on blood pressure, heart rate and respiration rate. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 2000; 20:173-6. [PMID: 10792409 DOI: 10.1046/j.1365-2281.2000.00242.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To examine the physiological effects of Korean traditional Qi-training, we investigated the changes in blood pressure, heart and respiratory rates before, during and after ChunDoSunBup (CDSB) Qi-training. Twelve normal healthy CDSB Qi-trainees (19-37 years old; trained for 1.3 +/- 0.2 years; 9 men and 3 women) volunteered to participate in this study. Heart rate, respiratory rate, systolic blood pressure and rate-pressure product were significantly decreased during Qi-training. From these results, we suggest that CDSB Qi-training has physiological effects that indicate stabilization of cardiovascular system.
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Abstract
Various synthetic materials and plastic adhesives are used for neurovascular decompression, but they may have some adverse effects on nervous tissue. We used fibrin glue alone for neurovascular decompression and obtained excellent results without complications or recurrence, compared with the previous technique with a prosthesis or plastic adhesive.
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Lee MS, Jeong SM, Kim BG, Ryu H, Oh SW, Chung HT. A Minnesota multiphasic personality inventory profile of ChunDoSunBup qi-trainees: a preliminary study. THE AMERICAN JOURNAL OF CHINESE MEDICINE 1999; 27:307-13. [PMID: 10592839 DOI: 10.1142/s0192415x99000355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this study is to explore the effects of ChunDoSunBup Qi-training on personality traits. Twenty-six normal healthy subjects (mean age = 26.58 +/- 6.56) and 26 CDSB Qi-trainees (mean age = 27.74 +/- 5.21) participated in this study. Analysis of MMPI profiles showed that CDSB Qi-trainees scored significantly lower on Depression (D), Hysteria (Hy), Paranoia (Pa), Schizophrenia (Sc) and Frequency (F) and significantly higher on the Correction (K) Scales. In addition, CDSB Qi-trainees reported a significantly lower Cook-Medley Hostility (Ho) scale than that of controls. This preliminary study suggests that CDSB Qi-training may be effective in protection as well as restoration of emotional, psychological symptomatology and personality trait disorder.
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Abstract
A patient with a ruptured intracranial aneurysm of the right persistent primitive hypoglossal artery is described. Clipping of the aneurysmal neck was achieved by a far lateral approach together with drilling of the jugular tubercle, and it was concluded that this approach should be followed for safe and complete clipping.
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Ryu H, Nishizawa S, Yamamoto S. One-stage removal of a large dumb-bell-shaped cervical neurinoma without laminectomy or interbody fusion in a child. Br J Neurosurg 1999; 13:587-90. [PMID: 10715728 DOI: 10.1080/02688699943105] [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: 10/17/2022]
Abstract
A 12-year-old boy had a large dumb-bell-shaped cervical neurinoma originating at the C5 spinal root that was removed in a one-stage operation through the enlarged C4/5 intervertebral foramen. This technique required no laminectomy, discectomy or interbody fusion, which may frequently produce spinal deformity in children.
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Ryu H, Yamamoto S. Microvascular decompression. J Neurosurg 1999; 91:1063-5. [PMID: 10584862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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Zaman K, Ryu H, Hall D, O'Donovan K, Lin KI, Miller MP, Marquis JC, Baraban JM, Semenza GL, Ratan RR. Protection from oxidative stress-induced apoptosis in cortical neuronal cultures by iron chelators is associated with enhanced DNA binding of hypoxia-inducible factor-1 and ATF-1/CREB and increased expression of glycolytic enzymes, p21(waf1/cip1), and erythropoietin. J Neurosci 1999; 19:9821-30. [PMID: 10559391 PMCID: PMC6782985] [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: 02/14/2023] Open
Abstract
Iron chelators are pluripotent neuronal antiapoptotic agents that have been shown to enhance metabolic recovery in cerebral ischemia models. The precise mechanism(s) by which these agents exert their effects remains unclear. Recent studies have demonstrated that iron chelators activate a hypoxia signal transduction pathway in non-neuronal cells that culminates in the stabilization of the transcriptional activator hypoxia-inducible factor-1 (HIF-1) and increased expression of gene products that mediate hypoxic adaptation. We examined the hypothesis that iron chelators prevent oxidative stress-induced death in cortical neuronal cultures by inducing expression of HIF-1 and its target genes. We report that the structurally distinct iron chelators deferoxamine mesylate and mimosine prevent apoptosis induced by glutathione depletion and oxidative stress in embryonic cortical neuronal cultures. The protective effects of iron chelators are correlated with their ability to enhance DNA binding of HIF-1 and activating transcription factor 1(ATF-1)/cAMP response element-binding protein (CREB) to the hypoxia response element in cortical cultures and the H19-7 hippocampal neuronal cell line. We show that mRNA, protein, and/or activity levels for genes whose expression is known to be regulated by HIF-1, including glycolytic enzymes, p21(waf1/cip1), and erythropoietin, are increased in cortical neuronal cultures in response to iron chelator treatment. Finally, we demonstrate that cobalt chloride, which also activates HIF-1 and ATF-1/CREB in cortical cultures, also prevents oxidative stress-induced death in these cells. Altogether, these results suggest that iron chelators exert their neuroprotective effects, in part, by activating a signal transduction pathway leading to increased expression of genes known to compensate for hypoxic or oxidative stress.
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Ryu H, Makino A, Hinokuma K. An arachnoid cyst involving only the hypoglossal nerve: case report and review of the literature. Br J Neurosurg 1999; 13:492-5. [PMID: 10627782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
We describe a patient with an arachnoid cyst, possibly of traumatic origin, at the hypoglossal canal producing atrophy of the tongue. An arachnoid cyst should be considered in the differential diagnosis of any patient with a localized cystic mass around the cranial nerves at the base of the skull.
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Lee MS, Kang CW, Ryu H, Kim JD, Chung HT. Effects of ChunDoSunBup Qi-training on growth hormone, insulin-like growth factor-I, and testosterone in young and elderly subjects. THE AMERICAN JOURNAL OF CHINESE MEDICINE 1999; 27:167-75. [PMID: 10467451 DOI: 10.1142/s0192415x99000215] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We observed the response of plasma growth hormone (GH), insulin-like growth factor-I (IGF-I) and testosterone (T) to an acute period of ChunDoSunBup (CDSB) Qi-training. Although the basal level of GH was not different between the two groups, after the portion of the training in which the subjects were physically active (the mid-training point), plasma GH levels increased by 7.26 fold (p < 0.05) in the elderly trainees and by 1.66 fold (p < 0.05) in the young. In response to CDSB Qi-training, IGF-I levels in the young increased significantly at mid-training point, but there were no increase in the elderly. Significant correlations existed between GH and IGF-I levels in the young subjects, but not in the elderly. The T level at the mid-training point increased significantly in elderly subjects but not in the young. These results suggest that CDSB Qi-training is a potential method for modulating of the secretion of growth factor in the young and the elderly, but that the elderly IGF-I response does not equal that of the young. In addition, our study suggests CDSB Qi-training may be one mode of therapy applicable to growth factor related disorders such as GH deficiency in children and osteoporosis in the elderly, especially women.
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Ohta S, Ryu H, Miura K. Eighteen-year survival of a patient with malignant pleomorphic xanthoastrocytoma associated with von Recklinghausen neurofibromatosis. Br J Neurosurg 1999; 13:420-2. [PMID: 10616574 DOI: 10.1080/02688699943583] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The authors report the first adult case of pleomorphic xanthoastrocytoma associated with neurofibromatosis-1. A 40-year-old man with history of neurofibromatosis-1 underwent total removal of a right temporo-parietal superficial glioma followed by radiation therapy. Eighteen years after surgery, the patient remained well with no tumour recurrence, which prompted review of the surgical material. The diagnosis of pleomorphic xanthoastrocytoma was then made though the tumour exhibited malignant features histologically, with marked necrosis. This extremely good clinical outcome suggest that some astrocytoma tumours in patients with neurofibromatosis might be associated with a favourable prognosis.
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Ryu H, Yamamoto S, Sugiyama K, Nishizawa S, Nozue M. Neurovascular compression syndrome of the eighth cranial nerve. Can the site of compression explain the symptoms? Acta Neurochir (Wien) 1999; 141:495-501. [PMID: 10392205 DOI: 10.1007/s007010050330] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Considerable skepticism still exists concerning the concept of neurovascular compression (NVC) syndromes of the eighth cranial nerve (8th N). If such syndromes exist, the sites of compression of the nerve must explain the symptoms encountered. We recorded compound action potentials of the cochlear nerve (CCAPs) during neurovascular decompression (NVD) to examine the topography of the three components of the 8th N. The sites of compression of the 8th N in cases of NVC syndrome confirmed at surgery were superimposed on the topography of the CN and vestibular nerve (VN) in order to determine the relationship between the sites of compression and the symptoms. CCAPs were clearly and consistently recorded on the caudal surface of the 8th N along the midline. In patients with vertigo and tinnitus there was vascular compression of the rostroventral (VN) and caudal surface (CN) of the nerve, respectively. In patients with both vertigo and tinnitus, there was compression of both VN and CN. Our findings clearly demonstrate that the symptoms of NVC of the 8th N depend on the part of the nerve that is compressed by blood vessels, and they support the concept of NVC syndrome of the 8th N.
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