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Hong CJ, Lin CH, Yu YW, Yang KH, Tsai SJ. Genetic variants of the serotonin system and weight change during clozapine treatment. PHARMACOGENETICS 2001; 11:265-8. [PMID: 11337942 DOI: 10.1097/00008571-200104000-00010] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Clozapine-induced weight gain may impair health and affect patient compliance. The aim of this study is to investigate the relationship between the genetic variants of the serotonin system and clozapine-induced body weight change (BWC). Ninety-three treatment-resistant schizophrenic patients were weighed monthly for 4 months during clozapine treatment. At the conclusion of treatment, patients had gained an average of 2.4 kg body weight, with BWC ranging from -17.5 to +12.9 kg. The levels of the serotonin transporter variants, serotonin 2A, serotonin 2C and serotonin 6, demonstrated no statistically significant relationship to BWC. Patients with a lower initial body mass index demonstrated a greater weight gain associated with clozapine treatment. Further exploration of the neurotransmitters implicated in the antipsychotic-induced BWC is important in order to reduce the morbidity and noncompliance associated with weight gain.
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Ala TA, Yang KH, Sung JH, Frey WH. Clinical parkinsonism in dementia patients with substantia nigra Lewy bodies. J Neural Transm (Vienna) 2001; 106:47-57. [PMID: 10195334 DOI: 10.1007/s007020050140] [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: 10/28/2022]
Abstract
In a retrospective clinicopathological study, we examined the substantia nigra (SN) of 48 dementia patients with SN Lewy bodies (LBs) to determine if the severity of degeneration correlated with either the occurrence of signs of parkinsonism at dementia presentation or with the frequency of treatment for parkinsonism during the disease course. The SN specimens were graded for microscopic degeneration using a semi-quantitative five-tiered scale. Whereas no correlation was found between the grade of degeneration and occurrence of signs at presentation (r = -0.16, p = 0.18), with 16 of 38 patients having had signs reported, a more severe grade was statistically correlated with an increased frequency of treatment during the course (r = 0.41, p = 0.004), with ten of 41 patients having been treated for parkinsonism. Contrary to our expectations, we found that fewer than half of the patients with the two most severe grades of degeneration presented with signs of parkinsonism or were ever treated for parkinsonism.
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Hong CJ, Yu YW, Lin CH, Song HL, Lai HC, Yang KH, Tsai SJ. Association study of apolipoprotein E epsilon4 with clinical phenotype and clozapine response in schizophrenia. Neuropsychobiology 2001; 42:172-4. [PMID: 11096331 DOI: 10.1159/000026689] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Schizophrenic patients with the apolipoprotein E (APOE = gene; apoE = protein) epsilon4 allele exhibited lower psychosis scores than patients without the epsilon4 allele in previous reports. The present study tested the hypothesis that the APOE epsilon4 allele confers association with the clinical manifestations of schizophrenia or clozapine response. A total of 95 schizophrenic patients who were treatment resistant were included in the study. The results demonstrated that the presence of the APOE epsilon4 allele did not influence the response to clozapine in schizophrenic patients, neither was the baseline psychopathology related to the APOE epsilon4 allele. Given the multiple functions of the apoE protein in the brain, further study of the influence of APOE on CNS medication response is needed.
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Abstract
This paper reviews the traditional areas of impact biomechanics as they relate to brain injury caused by blunt impact. These areas are injury mechanisms, human response to impact, human tolerance to impact and the use of human surrogates. With the advent of high-speed computers, it is now possible to add computer models to the list of human surrogates that used to be limited to animals and human cadavers. The advantages and shortcomings of current computer models are discussed. One of the computer models was used to predict the pressures and shear stresses developed in the brain and the extent of stretch of the bridging veins in the brains of American football players who sustained severe helmet-to-helmet head impact during the game. It was found that increases in intracranial pressure were more dependent on translational acceleration while the primary determinant for the development of shear stresses in the brain is rotational acceleration. Although the current head injury criterion is based almost entirely on translational acceleration, it is recommended that any new criterion should reflect the contribution of both translational and rotational acceleration.
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Kim J, Hwang JS, Cho YK, Han Y, Jeon YJ, Yang KH. Protective effects of (-)-epigallocatechin-3-gallate on UVA- and UVB-induced skin damage. SKIN PHARMACOLOGY AND APPLIED SKIN PHYSIOLOGY 2001; 14:11-9. [PMID: 11174086 DOI: 10.1159/000056329] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It has been known that green tea and its components possess significant chemopreventive effects against chemical carcinogens and photo-caused skin tumor formation. In this study, the protective effects of (-)-epigallocatechin-3-gallate (EGCG), a major green tea catechin, on the ultraviolet (UV)-induced skin damage (photoaging) were studied in guinea pigs, hairless mice and human dermal fibroblast cultures. The lipid peroxidation was significantly reduced in the EGCG-treated group. The amount of lipid peroxides produced in the control and EGCG treated group were 838 +/- 144 and 286 +/- 57 nmol/mg at 18 h after UV irradiation, respectively. UVB-induced erythema was also significantly reduced in the EGCG treated group. The erythema relative index of the control and the EGCG treated group were 311 +/- 45 and 191 +/- 49 at 16 h after UV irradiation, respectively. EGCG treatment reduced UVA-induced skin damage (roughness and sagginess) and protected from the decrease of dermal collagen in hairless mouse skin. EGCG treatment blocked the UV-induced increase of collagen secretion and collagenase mRNA level in fibroblast culture. The nuclear transcription factors NF-kappaB and AP-1 binding activities were also inhibited by EGCG treatment.
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Zhang L, Yang KH, King AI. Comparison of brain responses between frontal and lateral impacts by finite element modeling. J Neurotrauma 2001; 18:21-30. [PMID: 11200247 DOI: 10.1089/089771501750055749] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study was conducted to investigate differences in brain response due to frontal and lateral impacts based on a partially validated three-dimensional finite element model with all essential anatomical features of a human head. Identical impact and boundary conditions were used for both the frontal and lateral impact simulations. Intracranial pressure and localized shear stress distributions predicted from these impacts were analyzed. The model predicted higher positive pressures accompanied by a relatively large localized skull deformation at the impact site from a lateral impact when compared to a frontal impact. Lateral impact also induced higher localized shear stress in the core regions of the brain. Preliminary results of the simulation suggest that skull deformation and internal partitions may be responsible for the directional sensitivity of the head in terms of intracranial pressure and shear stress response. In previous experimental studies using subhuman primates, it was found that a lateral impact was more injurious than a frontal impact. In this study, shear stress in the brain predicted by the model was much higher in a lateral impact in comparison with a frontal impact of the same severity. If shear deformation is considered as an injury indicator for diffuse brain injuries, a higher shear stress due to a lateral impact indicate that the head would tend to have a decreased tolerance to shear deformation in lateral impact. More research is needed to further quantify the effect of the skull deformation and dural partitions on brain injury due to impacts from a variety of directions and at different locations.
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Iwamoto M, Miki K, Mohammad M, Nayef A, Yang KH, Begeman PC, King AI. Development of a finite element model of the human shoulder. STAPP CAR CRASH JOURNAL 2000; 44:281-97. [PMID: 17458732 DOI: 10.4271/2000-01-sc19] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Previous studies have hypothesized that the shoulder may be used to absorb some impact energy and reduce chest injury due to side impacts. Before this hypothesis can be tested, a good understanding of the injury mechanisms and the kinematics of the shoulder is critical for occupant protection in side impact. However, existing crash dummies and numerical models are not designed to reproduce the kinematics and kinetics of the human shoulder. The purpose of this study was to develop a finite element model of the human shoulder in order to achieve a deeper understanding of the injury mechanisms and the kinematics of the shoulder in side impact. Basic anthropometric data of the human shoulder used to develop the skeletal and muscular portions of this model were taken from commercial data packages. The shoulder model included three bones (the humerus, scapula and clavicle) and major ligaments and muscles around the shoulder. This model was then integrated into a human thorax model developed at Wayne State University (WSU) along with pre-existing models of other body parts such as the pelvis and the lower extremities. Material properties used for the model were taken from the literature. The model was first used to simulate lateral shoulder impact study by the Association Peugeot- Renault (APR) followed by simulations of several of the 17 rigid and padded cadaveric impacts conducted on a side impact sled at WSU. Contact forces measured at the levels of shoulder, thorax, abdomen and pelvis were used as response variables to validate the model. Additionally, a cadaveric test involving the deployment of a generic side airbag was also used to check the validity of the model. Model prediction of accelerations of the shoulder matched well against those measured experimentally. The role of the shoulder in side impact protection and the reduction of injury to the ribcage are discussed, based on model results.
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Yang KH, Blackwell KT. Analogue pattern matching in a dendritic spine model based on phosphorylation of potassium channels. NETWORK (BRISTOL, ENGLAND) 2000; 11:281-297. [PMID: 11128168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Modification of potassium channels by protein phosphorylation has been shown to play a role in learning and memory. If such memory storage machinery were part of dendritic spines, then a set of spines could act as an 'analogue pattern matching' device by learning a repeatedly presented pattern of synaptic activation. In this study, the plausibility of such analogue pattern matching is investigated in a detailed circuit model of a set of spines attached to a dendritic branch. Each spine head contains an AMPA synaptic channel in parallel with a calcium-dependent potassium channel whose sensitivity depends on its phosphorylation state. Repeated presentation of synaptic activity results in calcium activation of protein kinases and subsequent channel phosphorylation. Simulations demonstrate that signal strength is greatest when the synaptic input pattern is equal to the previously learned pattern, and smaller when components of the synaptic input pattern are either smaller or larger than corresponding components of the previously learned pattern. Therefore, our results indicate that dendritic spines may act as an analogue pattern matching device, and suggest that modulation of potassium channels by protein kinases may mediate neuronal pattern recognition.
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Luan F, Yang KH, Deng B, Begeman PC, Tashman S, King AI. Qualitative analysis of neck kinematics during low-speed rear-end impact. Clin Biomech (Bristol, Avon) 2000; 15:649-57. [PMID: 10946097 DOI: 10.1016/s0268-0033(00)00031-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To analyze neck kinematics and loading patterns during rear-end impacts. DESIGN The motion of each cervical vertebra was captured using a 250 frame/s X-ray system during a whole body rear-end impact. These data were analyzed in order to understand different phases of neck loading during rear-end impact. BACKGROUND The mechanism of whiplash injury remains largely unknown. An understanding of the underlying kinematics of whiplash is crucial to the identification of possible injury mechanisms before countermeasures can be designed. METHODS Metallic markers were inserted into the vertebral bodies and spinous processes of each of the seven cervical vertebrae. Relative displacement-time traces between each pair of adjacent cervical vertebrae were calculated from X-ray data. Qualitative analyses of the kinematics of the neck at different phase of impact were performed. RESULTS The neck experiences compression, tension, shear, flexion and extension at different cervical levels and/or during different stages of the whiplash event. CONCLUSIONS Neck kinematics during whiplash is rather complicated and greatly influenced by the rotation of the thoracic spine, which occurs as a result of the straightening of the kyphotic thoracic curvature. RELEVANCE Understanding the complicated kinematics of a rear-end impact may help clinicians and researchers shed some light on potential mechanisms of whiplash neck injury.
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Deng B, Begeman PC, Yang KH, Tashman S, King AI. Kinematics of human cadaver cervical spine during low speed rear-end impacts. STAPP CAR CRASH JOURNAL 2000; 44:171-88. [PMID: 17458726 DOI: 10.4271/2000-01-sc13] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The purposes of this study were to measure the relative linear and angular displacements of each pair of adjacent cervical vertebrae and to compute changes in distance between two adjacent facet joint landmarks during low posterior-anterior (+Gx) acceleration without significant hyperextension of the head. A total of twentysix low speed rear-end impacts were conducted using six postmortem human specimens. Each cadaver was instrumented with two to three neck targets embedded in each cervical vertebra and nine accelerometers on the head. Sequential x-ray images were collected and analyzed. Two seatback orientations were studied. In the global coordinate system, the head, the cervical vertebrae, and the first or second thoracic vertebra (T1 or T2) were in extension during rear-end impacts. The head showed less extension in comparison with the cervical spine. Relative motion for each cervical motion segment went from flexion at the upper cervical levels to extension at the lower cervical levels, with a transition region at the mid-cervical levels. This rotational pattern formed an "S" shape in the cervical spine during the initial phase of low-speed rear impacts. A pair of facet joint landmarks on each cervical motion segment was used to measure the distance across the joint space. Uni-axial facet capsular strains were calculated by dividing changes in this distance over the original distance in seven tests using three specimens. In 20-degree seatback tests, the average strain was 32+/-11% for the C2/C3 facet joint (17%-43% range), and 59+/-26% for the C3/C4 facet joint (41%-97% range). The C4/C5 and C5/C6 facet joints exhibited peak tensile or compressive strains in different specimens. In 0-degree seatback tests, the average strain was 28+/-11% for the C2/C3 facet joint (21%-41% range), 30+/-9% for the C3/C4 facet joint (21%-39% range), 22+/-4% for the C4/C5 facet joint (19%-25% range), and 60+/-13% for the C5/C6 facet joint (51%-69% range). In 20-degree seatback tests, there was less initial cervical lordosis, more upward ramping of the thoracic spine, and more relative rotation of each cervical motion segment in comparison with the 0-degree seatback tests. Relative to T1, the head went from flexion to extension for 20-degree seatback tests while stayed in extension for 0-degree seatback tests.
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Choi YJ, Lee JD, Yang KH, Woo JY, Kim BK, Bang BK, Shim SI. Immunotactoid glomerulopathy associated with idiopathic hypereosinophilic syndrome. Am J Nephrol 2000; 18:337-43. [PMID: 9653841 DOI: 10.1159/000013362] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A case of immunotactoid glomerulopathy in an 18-year-old man with an idiopathic hypereosinophilic syndrome is presented. The patient showed cervical lymphadenopathy, asymptomatic proteinuria of nephrotic range, and hematuria without any defined immunologic disease. Marked and prolonged hypereosinophilia was found in peripheral blood (eosinophil count; 6,248/mm3) and bone marrow (eosinophil series; 32%). Diffuse and/or nodular eosinophilic infiltration was identified in multiple organs such as kidney, stomach, liver, lymph node, and skin. Renal biopsy revealed endocapillary proliferative features of typical immunotactoid glomerulopathy with IgG and C3 deposition and microtubular structures of variable size, 20-80 nm in diameter, mainly in the subendothelium. This study suggests that immunotactoid glomerulopathy may be a secondary immunologic manifestation of the tissue damage by eosinophils in the idiopathic hypereosinophilic syndrome.
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Tsai SJ, Hong CJ, Yu YW, Lin CH, Song HL, Lai HC, Yang KH. Association study of a functional serotonin transporter gene polymorphism with schizophrenia, psychopathology and clozapine response. Schizophr Res 2000; 44:177-81. [PMID: 10962219 DOI: 10.1016/s0920-9964(99)00170-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Serotonin is implicated in the pathogenesis of schizophrenia. Following serotonin release, the serotonin transporter (5-HTT) is the major determinant of serotonin inactivation. The present study tested the hypothesis that a biallelic polymorphism in the 5' regulatory region of the 5-HTT gene (5-HTTLPR) confers susceptibility to schizophrenia, association with the clinical manifestations of schizophrenia or clozapine response. 90 treatment-resistant schizophrenic patients were assessed using the Brief Psychiatric Rating Scale before and after clozapine treatment. The results demonstrated that the 5-HTTLPR variants did not play a major role in the susceptibility, clinical manifestations or clozapine response in schizophrenia.
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Dai G, Yang KH, Li QH. [Bibliometric analysis on tissue engineering research literatures]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2000; 14:308-10. [PMID: 12516484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To comprehend the progress of tissue engineering research and speculate its developmental trends. METHODS MEDLINE search was conducted to retrieve the papers published between 1987 to 1999 under the main headings of tissue engineering. Years, nationalities, languages, journals, authors and heading frequencies of 314 papers were analyzed by bibliometrics. RESULTS Since 1990, the number of tissue engineering research literatures had doubled, and papers between 1998 and 1999 made up 57.96% of the total papers. All papers came from 15 nations, in 6 languages and 140 journals; 64.97% came from United States and 25.79% from England, Netherlands and Germany; 93.95% was in English; 42.04% was published on 15 journals. Vacanti JP and 19 other authors presented 5 to 24 papers. Heading frequencies were cytology 22.89%, transplantation 13.30%, scaffolds and extracellular matrixes 11.72%, implanting 10.60%, polymers 8.91%, potential applications 8.91%, artificial substitutes 6.88%, tissue culture 6.70% and biogenetics 4.96%. CONCLUSION Tissue engineering literatures mainly come from United States, England, Netherlands and Germany. English is the major language. J Biomed Mater Res and 14 other journals are important journals about tissue engineering research. Vacanti JP and 19 other authors are prolific authors. Cytology, transplantation, scaffolds and extracellular matrixes and implanting are hot topics and key points on tissue engineering research.
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Lee YW, Han SH, Lee M, Yang KH, Kim HM, Jeon YJ. 2-Amino-3-methylimidazo[4,5-f]quinoline inhibits nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells by blocking p38 kinase activation. Cancer Lett 2000; 156:133-9. [PMID: 10880762 DOI: 10.1016/s0304-3835(00)00452-3] [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: 11/25/2022]
Abstract
We show that 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a heterocyclic amine, significantly inhibits nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophages. The decrease in NO production was found to correlate well with a decrease in inducible NO synthase (iNOS) mRNA expression as demonstrated by Northern blot analysis. Treatment of RAW 264.7 cells with IQ selectively inhibited the activation of NF-kappaB/Rel, an important transcription factor of iNOS gene expression, while neither AP-1 nor Oct was affected by IQ. Since iNOS transcription has been shown recently to be under the control of the p38 kinase signaling cascade, we assessed the effect of IQ on p38 kinase activation. Treatment of RAW 264.7 with IQ inhibited LPS-stimulated p38 kinase phosphorylation in a dose-related manner. IQ also inhibited the p38 kinase activity. Collectively, this series of experiments indicates that IQ inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Based on our findings, the most likely mechanism that can account for this biological effect involves the negative regulation of NF-kappaB/Rel and p38 kinase pathway.
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Jeon YJ, Han SH, Lee YW, Lee M, Yang KH, Kim HM. Dexamethasone inhibits IL-1 beta gene expression in LPS-stimulated RAW 264.7 cells by blocking NF-kappa B/Rel and AP-1 activation. IMMUNOPHARMACOLOGY 2000; 48:173-83. [PMID: 10936515 DOI: 10.1016/s0162-3109(00)00199-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In the present study, the mechanism by which dexamethasone (DEX) inhibited IL-1beta gene expression in bacterial lipopolysaccharide (LPS)-activated RAW 264.7 cells was investigated. The decrease in LPS-induced IL-1beta mRNA expression was demonstrated by quantitative reverse transcription polymerase chain reaction (RT-PCR). Since the promoter in IL-1beta gene contains binding motifs for NF-kappaB/Rel, AP-1, NF-IL6, and CREB/ATF, which appear to be important in LPS-mediated IL-1beta induction, the effects of DEX on the activation of these transcription factors were examined. Treatment of DEX to RAW 264.7 cells induced a dose-related inhibition of NF-kappaB/Rel and AP-1 in chloramphenicol acetyltransferase activity, while neither NF-IL6 nor CREB/ATF activation was affected by DEX. Treatment of RAW 264.7 cells with DEX inhibited DNA binding of NF-kappaB/Rel and AP-1 proteins to their cognate DNA sites as measured by electrophoretic mobility shift assay (EMSA). DEX treatment caused a significant reduction in nuclear c-rel, p65, and p50 protein contents, and these decreases were paralleled by the accumulation of cytoplasmic c-rel, p65, and p50. DEX treatment of RAW 264.7 cells did not inhibit the nuclear translocation of c-jun and c-fos. We found that the inhibition of IL-1beta production by DEX is not related to p38, which is important in the IL-1beta induction. These results suggest that DEX may inhibit IL-1beta gene expression by a mechanism involving the blocking of LPS-induced NF-kappaB/Rel and AP-1 activation.
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Cho KJ, Han SH, Kim BY, Hwang SG, Park KK, Yang KH, Chung AS. Chlorophyllin suppression of lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells. Toxicol Appl Pharmacol 2000; 166:120-7. [PMID: 10896853 DOI: 10.1006/taap.2000.8958] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, functions as an anticarcinogen and antioxidant. In the present study, we investigated the effect of CHL on nitric oxide production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Treatment with CHL inhibited nitric oxide production in the LPS-stimulated RAW 264. 7 cells in a dose-related manner. Competitive RT-PCR analysis, using a DNA competitor as an internal standard, demonstrated that the treatment with 1, 10, and 50 microM CHL decreased LPS-induced iNOS mRNA expression in a concentration-dependent manner. Since the expression of the iNOS gene is mainly regulated by NF-kappaB, we then examined the effects of CHL on the NF-kappaB DNA binding activity, using an electrophoretic mobility shift assay. CHL down-regulated the NF-kappaB DNA binding on its cognate recognition site at the concentrations just noted. Employing a transfection and reporter gene expression system with p(NF-kappaB)(3)-chloramphenicol acetyl transferase (CAT), the treatment of CHL produced a dose-dependent inhibition of CAT activity in RAW 264.7 cells. Furthermore, CHL partially restored LPS-decreased IkappaBalpha, an inhibitory protein against NF-kappaB activation, in the cytosolic extract from the LPS-treated cells determined by immunoblot analysis. CHL also protected the hydroxyl radical-induced cytotoxicity in RAW 264.7 cells, indicating its antioxidant effect. These results suggest that CHL suppresses the nitric oxide production and iNOS mRNA expression mediated by the inhibition of NF-kappaB activation, and its action mechanism may be based on its antioxidant effect.
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Chang SC, Miller G, Halbert CF, Yang KH, Chao WC, Wei FC. Limiting donor site morbidity by suprafascial dissection of the radial forearm flap. Microsurgery 2000; 17:136-40. [PMID: 9016457 DOI: 10.1002/(sici)1098-2752(1996)17:3<136::aid-micr7>3.0.co;2-k] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A technique of suprafascial flap elevation to prevent donor site problems is described, based on careful intraoperative observation of the anatomical relations of all involved structures in a series of over 400 free forearm flaps used in various reconstructive procedures.
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Ala TA, Yang KH, Sung JH, Frey WH. Inconsistency between severe substantia nigra degeneration with Lewy bodies and clinical parkinsonism in dementia patients: a cliniconeuropathological study. Acta Neuropathol 2000; 99:511-6. [PMID: 10805094 DOI: 10.1007/s004010051153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In a retrospective cliniconeuropathological study, we reviewed all the cases received in our dementia brain bank during a 4-year period to determine if all patients with severe substantia nigra (SN) degeneration and SN Lewy bodies (LBs) exhibited prominent signs of parkinsonism and were treated for parkinsonism during the disease course. The SN of 426 cases were graded for microscopic degeneration using a semiquantitative five-tiered scale, with grade 0 indicating normal and grade 4 the most severe degeneration. Twenty-nine cases with grade 3 (16) or grade 4 (13) SN degeneration with SN LBs and clinical records were identified. Ten had been treated for parkinsonism (6 grade 3, 4 grade 4) and 19 had not. Whereas most of the patients had exhibited signs of end-stage parkinsonism during their last year, 1 grade 3 and 2 grade 4 patients apparently never exhibited prominent signs of parkinsonism during the course of their dementia. No clear neuropathological differences were noted between these patients that did not have prominent signs and a control group of six patients with clinical Parkinson's disease with dementia (parkinsonism onset at least 1 year before dementia onset). We conclude that in patients with dementia there is an inconsistent relationship between the expression of clinical parkinsonism during life and severe SN degeneration with LBs identified at necropsy.
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Yea SS, Kim HM, Jeon YJ, Oh HM, Jeong HG, Yang KH. Suppression of IL-2 and IL-4 gene expression by nodularin through the reduced NF-AT binding activity. Toxicol Lett 2000; 114:215-24. [PMID: 10713487 DOI: 10.1016/s0378-4274(99)00299-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nodularin is a cyclic peptide produced by cyanobacteria. In the present study, the inhibitory effect of nodularin on T lymphocyte functions was demonstrated. Direct addition of nodularin to B6C3F1 mouse splenocyte cultures produced a concentration-dependent inhibition of the lymphoproliferative response to concanavalin A stimulation. Nodularin inhibited PMA plus ionomycin (Io)-induced IL-2 mRNA expression in murine splenocytes and thymocytes as determined by quantitative/competitive RT-PCR. To further characterize the mechanism for the transcriptional regulation of IL-2, the binding activity of transcription factors, NF-AT, AP-1, NF-kappaB, and Oct, was evaluated by electrophoretic mobility shift assays in mouse splenocytes. Nodularin reduced the NF-AT binding activity in PMA/Io-induced splenocytes, but no significant effect was observed on AP-1, NF-kappaB, or Oct binding activity. Nodularin also inhibited IL-4 mRNA expression in PMA/Io-stimulated murine splenocytes. These results suggest that T lymphocyte is a possible cellular target of nodularin, and the inhibitory effect of nodularin on T-cell specific transcription factor NF-AT induces T-cell dysfunction, which leads to a diminution in IL-2 and IL-4 gene transcription.
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Lee M, Yang KH. 2-Acetylaminofluorene suppresses immune response through the inhibition of nuclear factor-kappaB activation during the early stage of B cell development. Toxicol Lett 2000; 114:173-80. [PMID: 10713482 DOI: 10.1016/s0378-4274(99)00294-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
2-Acetylaminofluorene (AAF), an arylamide carcinogen, has been known to inhibit humoral and cell-mediated immune response by lipopolysaccharide (LPS). In the current study we demonstrate that AAF induced the down-regulation of protein kinase C (PKC) that is a key enzyme in the pathways leading to LPS-induced B-cell proliferation, while having no inhibitory effect on intracellular cAMP in spleen cells. Additionally, to identify the mechanism of action of AAF during B-cell development, we determined the effects of AAF on LPS-induced nuclear factor-kappaB (NF-kappaB) activation in 70Z/3 murine pre-B cells, CH12 murine mature B cells and S194 murine plasmacytoma cells. LPS-induced NF-kappaB activation, which is dependent on PKC, was inhibited by pretreatment with AAF for 2 h in the nuclei of 70Z/3 murine pre-B cells by detection of NF-kappaB specific DNA-protein binding. Conversely, AAF barely inhibited the constitutive NF-kappaB binding activity in mature B-cells, S194 and CH12. To confirm the effect of AAF on NF-kappaB activation, a chloramphenicol acetyl transferase (CAT) expression vector containing multiple copies of the NF-kappaB element (pCAT(kappaB)(3)) was transiently transfected into 70Z/3 or S194 cells, and assessed for inducible CAT activity. AAF treatment of 70Z/3 cells resulted in a significant inhibition of CAT activity induced by LPS. However, AAF exhibited no inhibitory effect on constitutive CAT activity in mature B cells, S194, indicating that AAF no longer has suppressive effects on the immune response in differentiated B cells. Taken together, these results suggest that AAF may act to suppress immune response by blocking the activation of PKC and nuclear expression of NF-kappaB at the early stage of B cell development.
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Yea SS, Yang KH, Kaminski NE. Role of nuclear factor of activated T-cells and activator protein-1 in the inhibition of interleukin-2 gene transcription by cannabinol in EL4 T-cells. J Pharmacol Exp Ther 2000; 292:597-605. [PMID: 10640296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
We previously reported that immunosuppressive cannabinoids inhibited interleukin (IL)-2 steady-state mRNA expression and secretion by phorbol-12-myristate-13-acetate plus ionomycin-activated mouse splenocytes and EL4 murine T-cells. Here we show that inhibition of IL-2 production by cannabinol, a modest central nervous system-active cannabinoid, is mediated through the inhibition of IL-2 gene transcription. Moreover, electrophoretic mobility shift assays demonstrated that cannabinol markedly inhibited the DNA binding activity of nuclear factor of activated T-cells (NF-AT) and activator protein-1 (AP-1) in a time- and concentration-dependent manner in activated EL4 cells. The inhibitory effects produced by cannabinol on AP-1 DNA binding were quite transient, showing partial recovery by 240 min after cell activation and no effect on the activity of a reporter gene under the control of AP-1. Conversely, cannabinol-mediated inhibition of NF-AT was robust and sustained as demonstrated by an NF-AT-regulated reporter gene. Collectively, these results suggest that decreased IL-2 production by cannabinol in EL4 cells is due to the inhibition of transcriptional activation of the IL-2 gene and is mediated, at least in part, through a transient inhibition of AP-1 and a sustained inhibition of NF-AT.
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Abstract
We performed endoscopic bone grafting for eight patients of delayed union and nonunion which developed after femoral and humeral shaft fractures. The mean interval from initial intervention to endoscopic bone grafting was 7.3 months. Six patients of delayed union and nonunion healed at 4.1 months on average. Two patients had unsatisfactory healing and eventually underwent non-endoscopic revisional surgery. There was no intraoperative on postoperative complication. Endoscopic bone grafting can be a less invasive alternative, obtaining rapid bone union in cases of compromised healing of the diaphyseal fracture.
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Yang KH, Han DY, Kim HS. Removal of the deeply inserted proximal interlocking screw in the greater trochanter after femoral nailing. J Orthop Trauma 1999; 13:506-8. [PMID: 10513974 DOI: 10.1097/00005131-199909000-00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Removal of the proximal interlocking screw (PIS), especially one that is deeply inserted in the greater trochanter or covered by heterotopic ossification, is troublesome and requires considerable effort because the search for its head usually requires removing bone from around the insertion site. We introduce a simple tip to remove this complicated PIS with the aid of a proximal drill guide, drill bit, and AO countersink.
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Han SH, Jeon YJ, Yea SS, Yang KH. Suppression of the interleukin-2 gene expression by aflatoxin B1 is mediated through the down-regulation of the NF-AT and AP-1 transcription factors. Toxicol Lett 1999; 108:1-10. [PMID: 10472804 DOI: 10.1016/s0378-4274(99)00008-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The effect of aflatoxin B1 (AFB1) on the interleukin-2 (IL-2) gene expression was investigated in thymocytes of B6C3F1 mice, Jurkat E6-1 human T-cell leukemia, and EL4.IL-2 murine thymoma. AFB1 inhibited the phorbol-12myristate-13-acetate/i6nomycin (PMA/Io)-induced IL-2 mRNA expression in the murine thymocytes and Jurkat E6-1 cells as determined by qualitative RT-PCR, while no effect was observed in the EL4.IL-2 cells. Electrophoretic mobility shift assay indicated that AFB1 treatment showed an inhibition of the NF-AT and AP-1 DNA binding in PMA/Io-stimulated thymocytes and Jurkat E6-1 cells. No effect was observed on the Oct and NF-kappaB DNA binding. Employing a reporter gene expression system with p(NF-AT)3-CAT and p(AP-1)3-CAT, treatment with AFB1 to the transfected Jurkat E6-1 cells also showed an inhibition of the PMA/Io-induced NF-AT/CAT and AP-1/CAT activities. These results suggest that suppression of the IL-2 gene expression by AFB1 is mediated through the down-regulation of the NF-AT and AP-1 activation.
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Lien TF, Horng YM, Yang KH. Performance, serum characteristics, carcase traits and lipid metabolism of broilers as affected by supplement of chromium picolinate. Br Poult Sci 1999; 40:357-63. [PMID: 10475633 DOI: 10.1080/00071669987458] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
1. This study investigated the effects of dietary supplementation with chromium picolinate on the performance, serum and carcase traits and lipid metabolism of broilers. In trial 1, 120 1-day-old broilers with an equal number of males and females were assigned at random to 4 groups with 3 replicates. Four treatments with dietary supplements of 0 (control), 800, 1600 and 3200 microg/kg of chromium picolinate were used. In trial 2, 6-week-old broilers (20) were used to determine how supplements of 0, 200, 400 and 800 microg/kg chromium in an incubation medium influence their hepatocyte lipogenic capacity and adipocyte lipolysis, in vitro. 2. Dietary supplements of 1600 and 3200 microg/kg chromium in broiler diets significantly increased food consumption (P<0.05); 1600 microg/kg markedly improved weight gain (P<0.05); 1600 and 3200 microg/kg groups showed increased liver lipid content (P<0.05). However, the abdominal fat content tended to decrease in these 2 groups. 3. Dietary supplements of 1600 and 3200 microg/kg of chromium decreased serum glucose and nonesterified fatty acids (NEFA) concentrations while increasing serum phospholipid content (P<0.05). Insulin concentration decreased only in birds receiving 3200 ppb chromium (P<0.05). Serum triacylglycerol (TG) clearance rate in chromium-supplemented groups was markedly enhanced (P<0.05). 4. In addition, chromium supplemented groups had increased serum HDL contents and also reduced serum VLDL and LDL contents (P<0.05). 5. Trial 2 indicated that lipogenesis from [U-14C]glucose by isolated hepatocytes was significantly enhanced by 400 ppb chromium (P<0.05). 6. The results from this study demonstrate that a supplement of 1600 microg/kg of chromium picolinate in the ration influences the growth, carcase, serum traits and lipid metabolism of broilers.
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