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Preston-Martin S, Pogoda JM, Mueller BA, Lubin F, Modan B, Holly EA, Filippini G, Cordier S, Peris-Bonet R, Choi W, Little J, Arslan A. Prenatal vitamin supplementation and pediatric brain tumors: huge international variation in use and possible reduction in risk. Childs Nerv Syst 1998; 14:551-7. [PMID: 9840378 DOI: 10.1007/s003810050271] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976-1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1051 cases and for 1919 controls in eight geographic areas of North America, Europe and Israel. While risk estimates varied by study center, combined results suggest that maternal supplementation for two trimesters may decrease risk of brain tumor [odds ratio (OR)=0.7; 95% confidence interval (CI)=0.5-0.9], with a trend toward less risk with longer duration of use (P trend= 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all three trimesters (OR=0.5; CI=0.3- 0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breast feeding. These findings are largely driven by data from the US, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied tremendously, from 3% in Israel and in France through 21% in Italy, 33% in Canada, 52% in Spain to 86-92% at the three US centers. The composition of the various multivitamin compounds taken also varied: daily dose of vitamin C ranged from 0 up to 600 mg; vitamin E from 0 to 70 mg; vitamin A from 0 to 30,000 IU and folate from 0 to 2000 mg. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine potential independent effects of these micronutrients.
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152
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Kim W, Tang Y, Okada Y, Torrey TA, Chattopadhyay SK, Pfleiderer M, Falkner FG, Dorner F, Choi W, Hirokawa N, Morse HC. Binding of murine leukemia virus Gag polyproteins to KIF4, a microtubule-based motor protein. J Virol 1998; 72:6898-901. [PMID: 9658142 PMCID: PMC109902 DOI: 10.1128/jvi.72.8.6898-6901.1998] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
A cDNA clone encoding a cellular protein that interacts with murine leukemia virus (MuLV) Gag proteins was isolated from a T-cell lymphoma library. The sequence of the clone is identical to the C terminus of a cellular protein, KIF4, a microtubule-associated motor protein that belongs to the kinesin superfamily. KIF4-MuLV Gag associations have been detected in vitro and in vivo in mammalian cells. We suggest that KIF4 could be involved in Gag polyprotein translocation from the cytoplasm to the cell membrane.
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153
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Preston-Martin S, Pogoda JM, Mueller BA, Lubin F, Modan B, Holly EA, Filippini G, Cordier S, Peris-Bonet R, Choi W, Little J, Arslan A. Results from an international case-control study of childhood brain tumors: the role of prenatal vitamin supplementation. ENVIRONMENTAL HEALTH PERSPECTIVES 1998; 106 Suppl 3:887-892. [PMID: 9646053 PMCID: PMC1533075 DOI: 10.1289/ehp.98106887] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976 to 1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1051 cases and 1919 controls from eight geographic areas in North America, Europe, and Israel. Although risk estimates varied by study center, combined results suggest that maternal supplementation for two trimesters may decrease risk of brain tumor (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.5-0.9), with a trend of less risk with longer duration of use (p trend = 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all three trimesters (OR 0.5, CI 0.3-0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breast feeding. These findings are largely driven by data from the United States, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied tremendously: from 3% in Israel and France, 21% in Italy, 33% in Canada, 52% in Spain and 86 to 92% at the three U.S. centers. The composition of the various multivitamin compounds taken also varied: the daily dose of vitamin C ranged from 0 to 600 mg, vitamin E ranged from 0 to 70 mg, vitamin A ranged from 0 to 30,000 IU, and folate ranged from 0 to 2000 micrograms. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine potential independent effects of these micronutrients.
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154
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Cho JS, Wilson JT, DiGiulio DC, Vardy JA, Choi W. Implementation of natural attenuation at a JP-4 jet fuel release after active remediation. Biodegradation 1998; 8:265-73. [PMID: 9523452 DOI: 10.1023/a:1008212127604] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
After eighteen months of active remediation at a JP-4 jet-fuel spill, a residual of unremediated hydrocarbon remained. Further site characterization was conducted to evaluate the contribution of natural attenuation to control exposure to hazards associated with the residual contamination in the subsurface. Activities included the detailed characterization of ground-water flow through the spill; the distribution of fuel contaminants in groundwater; and the analysis of soluble electron acceptors moving into the spill from upgradient. These activities allowed a rigorous evaluation of the transport of contaminants from the spill to the receptor of groundwater, the Pasquotank River. The transport of dissolved contaminants of concern, that is benzene, toluene, ethyl benzene, xylene isomers (BTEX) and methyl-tertiary-butyl ether (MTBE), into the river from the source area was controlled by equilibrium dissolution from the fuel spill to the adjacent groundwater, diffusion in groundwater from the spill to permeable layers in the aquifer, and advective transport in the permeable layers. The estimated yearly loading of BTEX compounds and MTBE into the receptor was trivial even without considering biological degradation. The biodegradation of hydrocarbon dissolved in groundwater through aerobic respiration, denitrification, sulfate reduction, and iron reduction was estimated from changes in ground-water chemistry along the flow path. The concentrations of target components in permanent monitoring wells continue to decline over time. Long term monitoring will ensure that the plume is under control, and no further active remediation is required.
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155
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Choi W, Dean RA. The adenylate cyclase gene MAC1 of Magnaporthe grisea controls appressorium formation and other aspects of growth and development. THE PLANT CELL 1997; 9:1973-83. [PMID: 9401122 PMCID: PMC157051 DOI: 10.1105/tpc.9.11.1973] [Citation(s) in RCA: 218] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Magnaporthe grisea, the causal agent of rice blast disease, differentiates a specialized infection structure called an appressorium that is crucial for host plant penetration. Previously, it was found that cAMP regulates appressorium formation. To further understand the cellular mechanisms involved in appressorium formation, we have cloned a gene (MAC1) encoding adenylate cyclase, a membrane-bound enzyme that catalyzes the production of cAMP from ATP, by using a polymerase chain reaction-based strategy. The entire gene was isolated and subcloned from a large insert bacterial artificial chromosome library. Sequence characterization showed that MAC1 has a high degree of identity with other adenylate cyclase genes from several filamentous fungi as well as yeasts. Gene deletion resulted in reduced vegetative growth, conidiation, and conidial germination. Transformants lacking MAC1 were unable to form appressoria on an inductive surface and were unable to penetrate susceptible rice leaves. mac1- transformants were also sterile and produced no perithecia. Appressorium formation was restored in the presence of exogenous cAMP derivatives. These results confirm that cell signaling involving cAMP plays a central role in the development and pathogenicity of M. grisea.
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156
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Gunawardana G, Rasmussen RR, Scherr M, Frost D, Brandt KD, Choi W, Jackson M, Karwowski JP, Sunga G, Malmberg LH, West P, Chen RH, Kadam S, Clement JJ, McAlpine JB. Corynecandin: a novel antifungal glycolipid from Coryneum modonium. J Antibiot (Tokyo) 1997; 50:884-6. [PMID: 9402997 DOI: 10.7164/antibiotics.50.884] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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157
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Suh YH, Choi W, Kim SH, Kim JS, Rhi BY, Chong YH, Woo JI, Lee KW. Expression of Alzheimer's amyloid precursor protein in human lymphocyte. Arch Gerontol Geriatr 1997; 24:1-7. [PMID: 15374130 DOI: 10.1016/s0167-4943(96)00721-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/1996] [Revised: 05/29/1996] [Accepted: 06/06/1996] [Indexed: 10/18/2022]
Abstract
Beta-amyloid precursor protein (betaAPP) has been shown to be involved in cell growth regulation. In spleen, the majority of cells showing betaAPP like immunoreactivity was found in the T cell-dependent zone. In Northern blot, the expression of betaAPP was increased to reach the peak at 72 h after the treatment of phytohemagglutinin (PHA). But, in cytofluorometry, almost all CD4(+) T helper/inducer cells and the majority of CD(8+) T suppressor/cytotoxic cells show betaAPP immunoreactivity which remained constant during the stimulation with PHA. These results suggest that betaAPP is a surface molecule of T lymphocyte and the turnover or release of APP might be increased with the treatment of T cell mitogen.
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158
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Park CH, Kim SH, Choi W, Lee YJ, Kim JS, Kang SS, Suh YH. Novel anticholinesterase and antiamnesic activities of dehydroevodiamine, a constituent of Evodia rutaecarpa. PLANTA MEDICA 1996; 62:405-409. [PMID: 8923803 DOI: 10.1055/s-2006-957926] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To find a new compound with antiamnesic activity, we screened 29 natural products for their abilities to inhibit acetylcholinesterase and reverse scopolamine-induced amnesia. Among the plants tested Evodia rutaecarpa Bentham showed a strong inhibitory effect on acetylcholinesterase in vitro and an anti-amnesic effect in vivo. By sequential fractionation of E. rutaecarpa, the active component was finally identified as dehydroevodiamine hydrochloride (DHED). DHED inhibited acetylcholinesterase activity in a dose-dependent and non-competitive manner. The IC50 value of DHED is 37.8 microM. A single administration of DHED to rats (6.25 mg/kg) significantly reversed the scopolamine-induced memory impairment in a passive avoidance test. The antiamnesic effect of DHED was more potent than that of tacrine which is the only drug for Alzheimer's disease approved by FDA. This potent antiamnesic effect of DHED was thought to be due to the combined effects of acetylcholinesterase inhibition and the known cerebral blood flow enhancement. These results indicate that DHED has novel anti-cholinesterase and antiamnesic activities and might have therapeutic potential in various disorders including Alzheimer's disease.
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159
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Choi W, Camassa R. Long Internal Waves of Finite Amplitude. PHYSICAL REVIEW LETTERS 1996; 77:1759-1762. [PMID: 10063164 DOI: 10.1103/physrevlett.77.1759] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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160
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Lee DH, Park HJ, Song SY, Lee SJ, Choi W, Lee YC, Chung JB, Kang JK, Park IS, Lee YH, Kim HK. Evaluation of therapeutic regimens for the treatment of Helicobacter pylori infection. Yonsei Med J 1996; 37:270-7. [PMID: 8942297 DOI: 10.3349/ymj.1996.37.4.270] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Helicobacter pylori (H. pylori) is currently considered the most important exogenous factor in the genesis of gastritis and peptic ulcer disease. However, the optimum regimen for the eradication of H. pylori remains unclear. The purpose of this study was to evaluate the eradication rate of H. pylori, the side effects, and the patients' compliance with regard to various drug regimens. We also analyzed factors influencing the eradication of H. pylori. One hundred and eighty patients were included and divided into four groups: 42 patients (Group I) received tripotassium dicitrato bismuthate (240 mg b.i.d.), metronidazole (250 mg t.i.d.) and amoxicillin (500 mg t.i.d.) for 14 days; 55 patients (Group 2) received omeprazole (20 mg b.i.d.) and amoxicillin (1000 mg b.i.d.) for 14 days; 36 patients (Group 3) were treated with omeprazole (20 mg b.i.d.), metronidazole (250 mg t.i.d.) and amoxicillin (500 mg t.i.d.) for 14 days; and 47 patients (Group 4) received omeprazole (20 mg q.d.) and amoxicillin (500 mg t.i.d.) for 14 days and then tripotassium dicitrato bismuthate (240 mg b.i.d.) and nizatidine (150 mg q.d.) for 14 days. The diagnosis of H. pylori was made by histology. The eradication of H. pylori was defined both by histology (H&E and Giemsa stain) and by rapid urease test (CLOR) showing negative for H. pylori 4 weeks after the completion of therapy. Of the 180 patients, 95 patients had non-ulcer dyspepsia, 40 patients had gastric ulcer and 45 patients had duodenal ulcer. The eradication rate of H. pylori was highest (89.3%) in Group 3, as compared with Group 1 (68.9%), Group 2 (65.4%), and Group 4 (48.9%). The eradication rate was significantly higher in Group 3 than in Groups 2 and 4 (p < 0.05). There was no significant difference in the eradication rate among clinical diagnosis, sex and age. But, in the conventional triple therapy (Group 1), the eradication rate was higher in male (78.6%) than in female (46.2%). The side effects in order, were nausea (22.1%), dizziness (19.5%), abdominal pain (11.6%) and diarrhea (97%), and there was no difference among the drug regimens. The compliance of the patients was good (more than 80% irrespective of drug regimen). On the basis of these findings, the side effects of the drugs seemed minimal, and the compliance of patients was good irrespective of the drug regimen. In conclusion, the triple therapy with omeprazole, metronidazole and amoxicillin was the most effective regimen and could be recommended for H. pylori eradication.
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161
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Suh YH, Chong YH, Kim SH, Choi W, Min K, Jeong SJ, Fraser SP, Djamgoz MB. Molecular physiology, biochemistry, and pharmacology of Alzheimer's amyloid precursor protein (APP). Ann N Y Acad Sci 1996; 786:169-83. [PMID: 8687017 DOI: 10.1111/j.1749-6632.1996.tb39060.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The function of APP is not yet known in detail but growing evidence exists that APP may mediate cell interactions with the cell surface or soluble glycoproteins and defense mechanisms in the CNS involving the immune system. We describe here the finding that almost all CD4+ lymphocytes and the majority of CD8+ lymphocytes were positive for A beta and the antibodies against A beta or APP did not inhibit the [3H]-thymidine uptake of mitogen-treated lymphocytes significantly. There were no differences in the A beta immunoreactivity on the cell surface of lymphocytes between Alzheimer's disease (AD) and control samples. Excessive amyloidogenic pathway of APP processing may be the final common pathway involved in the pathogenesis of AD. Thus, the identification of proteases or factors leading to aberrant proteolysis which process APP to yield a variety of potentially amyloidogenic fragments would promise pharmacological targets to develop anti-AD drugs. In attempts to define the proteases or factors which alter the balance between nonamyloidogenic and amyloidogenic processing pathways, our study indicates that thrombin or acetylcholinesterase(AChE)-associated protease may be involved in the amyloidogenic processing pathway of APP in vivo to generate amyloidogenic intermediates linked to amyloid deposition. Highly specific and dose-dependent direct modulation of APP processing by biologically available metal ions including Ca2+, Zn2+, Fe2+/Fe3+ and Al3+ suggest the disrupted metal homeostasis as factors leading to overaccumulation of APP and subsequent aberrant proteolysis utilizing excessive amyloidogenic processing pathway. There is mounting evidence that at least some of the neurotoxicity associated with AD is due to fragments from APP. Most research has focused on the toxic effect and the ion channel activity of A beta in causation of the disease. The possible role of other cleaved products of APP is less clear. We investigated the channel-forming ability of various products of APP when applied to Xenopus oocytes and their neurotoxicity in vitro. CT105 peptide was found to be exceedingly potent at 500 nM concentration in forming nonselective ion channels during application from either outside or inside the oocyte and more toxic than either of the A beta fragments, A beta 25-35, or A beta 1-40. Taken together, these results suggest the possible involvement of CT peptide in inducing the neurotoxicity characteristic of AD through the direct damage on the cell membrane. Therefore, we hypothesize that amyloidogenic CT may make nonselective ion channels or pores in the membrane and may cause neuronal death in the early stage of AD and then further metabolized to more stable and less toxic A beta which may be finally deposited in the brain where it could inflict further toxicity to neurons. Here we report successful inhibition of APP gene expression by antisense oligodeoxynucleotides at the mRNA or the protein level in in vitro and cell culture systems.
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162
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Chen RH, Tennant S, Frost D, O'Beirne MJ, Karwowski JP, Humphrey PE, Malmberg LH, Choi W, Brandt KD, West P, Kadam SK, Clement JJ, McAlpine JB. Discovery of saricandin, a novel papulacandin, from a Fusarium species. J Antibiot (Tokyo) 1996; 49:596-8. [PMID: 8698645 DOI: 10.7164/antibiotics.49.596] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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163
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Cho HS, Kim SS, Choi W, Kim SH, Jeong SJ, Chong YH, Lee YJ, Park CW, Lee KW. Age-related changes of mRNA expression of amyloid precursor protein in the brain of senescence-accelerated mouse. Comp Biochem Physiol B Biochem Mol Biol 1995; 112:399-404. [PMID: 7584867 DOI: 10.1016/0305-0491(95)00090-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
APP695 mRNA is only expressed in the brains of SAM. The expression of APP mRNA in SAM P1 mice brains is more marked than that in SAM R1 mice brain. APP mRNA expression was increased with advancing age in all brain regions of SAM P1 mice compared with SAM R1. Especially, the changes of the amount of APP mRNA in the prosencephalon and the mesencephalon are significant at P value of 0.05. We suggest that overexpression of APP mRNA may be related to accelerated aging phenomenon in the SAM brain. This is the first report of age-related increase in the amount of APP mRNA in the SAM brain.
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164
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Choi W, Hoffmann MR. Photoreductive Mechanism of CCl4 Degradation on TiO2 Particles and Effects of Electron Donors. ENVIRONMENTAL SCIENCE & TECHNOLOGY 1995; 29:1646-1654. [PMID: 22276890 DOI: 10.1021/es00006a031] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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165
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Suh YH, Chun YS, Lee IS, Kim SS, Choi W, Chong YH, Hong L, Kim SH, Park CW, Kim CG. Complete nucleotide sequence and tissue-specific expression of the rat phenylethanolamine N-methyltransferase gene. J Neurochem 1994; 63:1603-8. [PMID: 7931317 DOI: 10.1046/j.1471-4159.1994.63051603.x] [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: 01/27/2023]
Abstract
The rat phenylethanolamine N-methyltransferase (PNMT) gene was isolated from a genomic library by cross-hybridization with a bovine PNMT cDNA probe. Complete nucleotide sequence analysis of a genomic clone showed that this gene contained three exons and spanned about 2.8 kb in length. There were the acute-phase response element, TATA, SP1, and GRE sequences. The physicochemical properties of rat adrenal PNMT were different from those of the brainstem PNMT. However, northern blot and reverse transcription-polymerase chain reaction analysis showed that the rat PNMT gene may not express the multiple forms of mRNA. These results suggest that the rat PNMT gene might produce a single enzyme protein, whose activity may be differentially modulated by tissue-specific environment in the central and peripheral systems.
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166
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Choi JH, Chung HC, Yoo NC, Lee HR, Lee KH, Choi W, Lim HY, Koh EH, Kim JH, Roh JK. Changing trends in histologic types of lung cancer during the last decade (1981-1990) in Korea: a hospital-based study. Lung Cancer 1994; 10:287-96. [PMID: 8075972 DOI: 10.1016/0169-5002(94)90658-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A review of the histopathology and past history of 2229 patients with primary lung cancer diagnosed at the Yonsei University Medical Center from 1981 to 1990 was performed to investigate the changes in histologic types and the relationship to smoking history. The most frequent histologic type of lung cancer was squamous cell carcinoma (956 patients, 54.0%) followed by adenocarcinoma (311 patients, 17.6%) in males (1772 patients), and adenocarcinoma (206 patients, 45.1%) followed by squamous cell carcinoma (126 patients, 27.6%) in females (457 patients). In both sexes, the predominant type was adenocarcinoma under the age of 40, whereas squamous cell carcinoma was the most frequent type above the age of 40. While squamous cell carcinoma decreased over 10 years (54.3% in 1981, 44.3% in 1990), adenocarcinoma showed a gradually increased incidence (17.0% in 1981, 28.3% in 1990) in both sexes, and the proportion of small cell carcinoma and large cell carcinoma remained unchanged. These changes in histologic type were more prominent in non-smokers. In conclusion, the increasing incidence of adenocarcinoma in both sexes, especially in non-smokers, suggests the possible presence of etiologic factors other than smoking, such as environmental pollution.
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167
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Radák Z, Lee K, Choi W, Sunoo S, Kizaki T, Oh-ishi S, Suzuki K, Taniguchi N, Ohno H, Asano K. Oxidative stress induced by intermittent exposure at a simulated altitude of 4000 m decreases mitochondrial superoxide dismutase content in soleus muscle of rats. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1994; 69:392-5. [PMID: 7875134 DOI: 10.1007/bf00865401] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The effects were examined of 6-month intermittent hypobaric (4000 m) exposure on the antioxidant enzyme systems in soleus and tibialis muscles of rats. At the end of the 6-month experimental exposure, the six rats in both the exposed group and the control group were sacrificed. Immunoreactive mitochondrial superoxide dismutase (Mn-SOD) contents were measured as well as the activities of antioxidant enzymes [Mn-SOD, cytosolic SOD (Cu,Zn-SOD), catalase (CAT), and glutathione peroxidase (GPX)]. Thiobarbituric acid-reactive substances (TBARS) were also determined as an indicator of lipid peroxidation. The high altitude exposure resulted in a marked increase in TBARS content in soleus muscle, suggesting increased levels of oxygen free radicals. Conversely, significant decreases in both Mn-SOD content and activity in soleus muscle were noted after exposure. Such trends were not noticed in tibialis muscle. On the other hand, no significant changes in Cu,Zn-SOD, CAT, or GPX were observed in either muscle. These results suggested that the increases in lipid peroxidation were most probably a result of decreased Mn-SOD function which was more depressed in oxidative than in glycolytic muscle.
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168
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Chong YH, Jung JM, Choi W, Park CW, Choi KS, Suh YH. Bacterial expression, purification of full length and carboxyl terminal fragment of Alzheimer amyloid precursor protein and their proteolytic processing by thrombin. Life Sci 1994; 54:1259-68. [PMID: 8164508 DOI: 10.1016/0024-3205(94)00853-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Human amyloid protein precursor(APP770) and its carboxyl terminal portion (CT105) including beta/A4 domain were highly expressed using strong expression systems in E. coli. These recombinant APP peptides were purified with a combination of urea solubilization and ion-exchange chromatography and used for proteolytic processing by thrombin. Three thrombin cleavage sites were predicted by the decrease of APP770 and the appearance of M(r) 56, 27 and 18 kDa fragments containing beta/A4 domain on SDS-PAGE gel and on the immunoblot. A similar but limited proteolysis of platelet APPs exposed to thrombin resulted in the stimulated production of 60 and 27 KDa carboxyl terminal peptides containing the intact beta/A4. This thrombin mediated proteolysis was completely blocked by hirudin, the specific thrombin inhibitor. These results suggest that thrombin may play a role in altered processing of APP to generate potentially amyloidogenic intermediates in vivo leading to amyloid deposition.
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169
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Suh YH, Lee IS, Kim SS, Choi W, Park CW, Chung MH, Lim JK. Ligand binding characteristics of [3H] dihydroalprenolol in cerebral cortical membranes of young and old senescence-accelerated mouse. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C, COMPARATIVE PHARMACOLOGY AND TOXICOLOGY 1993; 104:423-6. [PMID: 8103434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1. The values of both Kd and Bmax of [3H] dihydroalprenolol binding in the cerebral cortical membranes of old-aged (12 month old) SAM-P/1 were not significantly different compared with those of young (2 month old) SAM-P/1. 2. The values of Ki of metoprolol in the young and old aged SAM were 119 +/- 39.5 nM and 157 +/- 55 nM, respectively. 3. The values of beta 1/beta 2 ratio of the young and old aged SAM were 1.67 +/- 0.15 and 1.64 +/- 0.13, respectively. 4. These results suggest that there were no significant changes of binding characteristics of beta 1 and beta 2 adrenoceptors during aging in the cerebral cortex of SAM.
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170
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Kaldor JM, Day NE, Bell J, Clarke EA, Langmark F, Karjalainen S, Band P, Pedersen D, Choi W, Blair V. Lung cancer following Hodgkin's disease: a case-control study. Int J Cancer 1992; 52:677-81. [PMID: 1428226 DOI: 10.1002/ijc.2910520502] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It is recognized that survivors of Hodgkin's disease are at a substantially increased risk of lung cancer. A collaborative group of population-based cancer registries and major treatment centers carried out a case-control study, in which 98 cases of lung cancer were identified in patients who had survived at least 1 year following a diagnosis of Hodgkin's disease. A total of 259 matched controls were selected from patients with Hodgkin's disease who did not develop subsequent lung cancer, and for both cases and controls detailed information was abstracted from medical records concerning stage and treatment of Hodgkin's disease. Patients treated with chemotherapy alone had about twice the risk of developing lung cancer than those treated by radiotherapy alone or both modalities. There was no increase in risk with cumulative number of cycles of chemotherapy. Among patients treated with radiotherapy alone, there was an increase in risk related to estimated radiation dose to the lung. There was also a strong association between cigarette smoking and the risk of lung cancer. The finding of a higher risk following chemotherapy than following radiotherapy was unexpected, but could not be explained by any identified methodological flaws. A plausible inference from the study is that all forms of Hodgkin's disease therapy are carcinogenic to the lung and that, in particular, chemotherapy is associated with an increase in risk which is at least comparable to and perhaps higher than the risk produced by radiotherapy.
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Abstract
METHODS. A randomly selected sample of Californian adults was surveyed by telephone to assess their knowledge, attitudes, and behaviors with respect to tobacco use and its control. The questions asked of this sample were whether they had recently (in the past 12 months) asked someone not to smoke in certain situations and whether they would ever consider doing such a thing. RESULTS. Results of the survey indicated that 59.1% of nonsmokers and 44.4% of smokers had asserted themselves within the past 12 months, while another 28.2 and 29.1% of the nonsmokers and smokers, respectively, indicated that they would consider asking someone not to smoke. Only 12.7% of the nonsmokers and 26.4% of the smokers indicated that they would not consider doing such a thing. Those more likely to object publicly to tobacco smoke are generally younger, are more educated, and have anti-tobacco attitudes related to either a specific health belief or social influence.
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172
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Smits JG, Choi W. Very large deflection with quadratic voltage dependence of ZnO on Si(3)N(4) bimorph. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 1992; 39:302-304. [PMID: 18263151 DOI: 10.1109/58.139129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
ZnO on Si(3)N(4) bimorphs have shown large deflections with quadratic dependence on applied voltages. Several effects are suggested that might explain these large deflections. No conclusion on the origin of these large deflections can yet be given.
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173
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Smits JG, Choi W. The constituent equations of piezoelectric heterogeneous bimorphs. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 1991; 38:256-270. [PMID: 18267583 DOI: 10.1109/58.79611] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The electromechanical characteristics of a heterogeneous piezoelectric bender subjected to various electrical and mechanical boundary conditions are discussed based on the results of the free bender analysis. The mechanical boundary conditions considered are: a mechanical moment at the end of the bender, a force applied perpendicularly to the tip of the bender, and a uniform load applied over the entire length of the bender. The constituent equations of the bender under these electromechanical influences are derived by calculating the internal energy assuming thermodynamic equilibrium.
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174
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Kaldor JM, Day NE, Pettersson F, Clarke EA, Pedersen D, Mehnert W, Bell J, Host H, Prior P, Karjalainen S, Neal F, Koch M, Band P, Choi W, Pompe Kirn V, Arslan A, Zaren B, Belch AR, Storm H. Leukemia following chemotherapy for ovarian cancer. Int J Gynaecol Obstet 1990. [DOI: 10.1016/0020-7292(90)90055-p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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175
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Kim JY, Bom HS, Kim YJ, Choi W. Adjuvant internal hepatic radiotherapy using colloidal 32P chromic phosphate in colorectal cancer. RADIATION MEDICINE 1990; 8:246-9. [PMID: 2093946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The purpose of the study is to investigate the value of adjuvant radiotherapy given in the form of colloidal chromic phosphate 32P suspension administered via portal vein, in preventing the growth of occult metastases in the liver. Twenty two patients (10 patients of treated group with 12 controls) were followed 12 months after operation. There was no significant change in the CBC and liver functions after administration of 32P labeled colloidal chromic phosphate. Although local recurrence rates were very similar in both groups of colorectal cancer (3/12 in the control group and 4/10 in the treated group), liver metastasis rates were quite different: 4/12 in the control group and none (0/10) in the treated group. In conclusion, 32P labeled colloidal chromic phosphate is expected to prevent liver metastases of completely resected colorectal cancer.
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176
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Kaldor JM, Day NE, Pettersson F, Clarke EA, Pedersen D, Mehnert W, Bell J, Host H, Prior P, Karjalainen S, Neal F, Koch M, Band P, Choi W, Pompe Kirn V, Arslan A, Zaren B, Belch AR, Storm H. Leukemia following chemotherapy for ovarian cancer. Int J Gynaecol Obstet 1990. [DOI: 10.1016/0020-7292(90)90615-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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177
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Kaldor JM, Day NE, Pettersson F, Clarke EA, Pedersen D, Mehnert W, Bell J, Host H, Prior P, Karjalainen S, Neal F, Koch M, Band P, Choi W, Pompe Kirn V, Arslan A, Zaren B, Belch AR, Storm H. Leukemia following chemotherapy for ovarian cancer. Int J Gynaecol Obstet 1990. [DOI: 10.1016/0020-7292(90)90150-j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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178
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Yoo-Hun S, Park IS, Kim HS, Huh SO, Kim SS, Chun YS, Choi W, Park CW. Cloning and analysis of the pseudogene for human epinephrine synthesizing enzyme, phenylethanolamine N-methyltransferase (PNMT). THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1990; 22:921-4. [PMID: 2279621 DOI: 10.1016/0020-711x(90)90298-h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1. This gene completely lacks the intervening sequences. 2. This gene is truncated at the 5' end peptide encoding region by 433 base pairs (bp). 3. The 502 bp of this gene containing poly(A) signal are completely identical to the 3' half of mRNA encoding region of functional gene. 4. This gene has a poly(A) tail and is flanked by direct repeat of 6 bp. 5. Here we report for the first time the complete sequence of a human pseudogene for phenylethanolamine N-methyltransferase and this is the first report of cloning of pseudogene for catecholamine biosynthetic enzymes.
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Abstract
Findings described in this report are for 6,763 white male Seventh-day Adventists who completed a dietary questionnaire in 1960. Between 1960 and 1980 mortality data were collected on cohort members. Overweight men had a significantly higher risk of fatal prostate cancer than men near their desirable weight. The predicted relative risk of fatal prostate cancer was 2.5 for overweight men. Suggestive positive associations were also seen between fatal prostate cancer and the consumption of milk, cheese, eggs, and meat. There was an orderly dose-response between each of the four animal products and risk. The predicted relative risk of fatal prostate cancer was 3.6 for those who heavily consumed all four animal products. The results of this study and others suggest that animal product consumption and obesity may be risk factors for fatal prostate cancer.
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180
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Kahn HA, Phillips RL, Snowdon DA, Choi W. Association between reported diet and all-cause mortality. Twenty-one-year follow-up on 27,530 adult Seventh-Day Adventists. Am J Epidemiol 1984; 119:775-87. [PMID: 6720674 DOI: 10.1093/oxfordjournals.aje.a113798] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
This report examines the association between mortality from all causes during a 21-year period and frequency of consumption of 28 specific foods among 27,530 adult California members of the Seventh-Day Adventist Church. Food consumption was measured at the beginning of the study (1960) by a self-administered questionnaire. Deaths were identified by computer-assisted matching of study subjects to the file of death certificates for all deaths that occurred in California during 1960-1980. All-cause mortality showed a significant negative association with green salad consumption and a significant positive association with consumption of eggs and meat. For green salad and eggs, the association was stronger for women; for meat, the association was stronger for men. All the observed associations were adjusted for age, sex, smoking history, history of major chronic disease, and age at initial exposure to the Adventist Church.
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