1
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Suh YA, Arnold RS, Lassegue B, Shi J, Xu X, Sorescu D, Chung AB, Griendling KK, Lambeth JD. Cell transformation by the superoxide-generating oxidase Mox1. Nature 1999; 401:79-82. [PMID: 10485709 DOI: 10.1038/43459] [Citation(s) in RCA: 1100] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Reactive oxygen species (ROS) generated in some non-phagocytic cells are implicated in mitogenic signalling and cancer. Many cancer cells show increased production of ROS, and normal cells exposed to hydrogen peroxide or superoxide show increased proliferation and express growth-related genes. ROS are generated in response to growth factors, and may affect cell growth, for example in vascular smooth-muscle cells. Increased ROS in Ras-transformed fibroblasts correlates with increased mitogenic rate. Here we describe the cloning of mox1, which encodes a homologue of the catalytic subunit of the superoxide-generating NADPH oxidase of phagocytes, gp91phox. mox1 messenger RNA is expressed in colon, prostate, uterus and vascular smooth muscle, but not in peripheral blood leukocytes. In smooth-muscle cells, platelet-derived growth factor induces mox1 mRNA production, while antisense mox1 mRNA decreases superoxide generation and serum-stimulated growth. Overexpression of mox1 in NIH3T3 cells increases superoxide generation and cell growth. Cells expressing mox1 have a transformed appearance, show anchorage-independent growth and produce tumours in athymic mice. These data link ROS production by Mox1 to growth control in non-phagocytic cells.
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26 |
1100 |
2
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Shi J, Blundell TL, Mizuguchi K. FUGUE: sequence-structure homology recognition using environment-specific substitution tables and structure-dependent gap penalties. J Mol Biol 2001; 310:243-57. [PMID: 11419950 DOI: 10.1006/jmbi.2001.4762] [Citation(s) in RCA: 924] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
FUGUE, a program for recognizing distant homologues by sequence-structure comparison (http://www-cryst.bioc.cam.ac.uk/fugue/), has three key features. (1) Improved environment-specific substitution tables. Substitutions of an amino acid in a protein structure are constrained by its local structural environment, which can be defined in terms of secondary structure, solvent accessibility, and hydrogen bonding status. The environment-specific substitution tables have been derived from structural alignments in the HOMSTRAD database (http://www-cryst.bioc. cam.ac.uk/homstrad/). (2) Automatic selection of alignment algorithm with detailed structure-dependent gap penalties. FUGUE uses the global-local algorithm to align a sequence-structure pair when they greatly differ in length and uses the global algorithm in other cases. The gap penalty at each position of the structure is determined according to its solvent accessibility, its position relative to the secondary structure elements (SSEs) and the conservation of the SSEs. (3) Combined information from both multiple sequences and multiple structures. FUGUE is designed to align multiple sequences against multiple structures to enrich the conservation/variation information. We demonstrate that the combination of these three key features implemented in FUGUE improves both homology recognition performance and alignment accuracy.
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24 |
924 |
3
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Yao LH, Jiang YM, Shi J, Tomás-Barberán FA, Datta N, Singanusong R, Chen SS. Flavonoids in food and their health benefits. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2004; 59:113-22. [PMID: 15678717 DOI: 10.1007/s11130-004-0049-7] [Citation(s) in RCA: 813] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
Abstract
There has been increasing interest in the research of flavonoids from dietary sources, due to growing evidence of the versatile health benefits of flavonoids through epidemiological studies. As occurrence of flavonoids is directly associated with human daily dietary intake of antioxidants, it is important to evaluate flavonoid sources in food. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. However, there is still difficulty in accurately measuring the daily intake of flavonoids because of the complexity of existence of flavonoids from various food sources, the diversity of dietary culture, and the occurrence of a large amount of flavonoids itself in nature. Nevertheless, research on the health aspects of flavonoids for humans is expanding rapidly. Many flavonoids are shown to have antioxidative activity, free-radical scavenging capacity, coronary heart disease prevention, and anticancer activity, while some flavonoids exhibit potential for anti-human immunodeficiency virus functions. As such research progresses. further achievements will undoubtedly lead to a new era of flavonoids in either foods or pharmaceutical supplements. Accordingly, an appropriate model for a precise assessment of intake of flavonoids needs to be developed. Most recent research has focused on the health aspects of flavonoids from food sources for humans. This paper reviews the current advances in flavonoids in food, with emphasis on health aspects on the basis of the published literature, which may provide some guidance for researchers in further investigations and for industries in developing practical health agents.
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Review |
21 |
813 |
4
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Fokkens WJ, Lund VJ, Hopkins C, Hellings PW, Kern R, Reitsma S, Toppila-Salmi S, Bernal-Sprekelsen M, Mullol J, Alobid I, Terezinha Anselmo-Lima W, Bachert C, Baroody F, von Buchwald C, Cervin A, Cohen N, Constantinidis J, De Gabory L, Desrosiers M, Diamant Z, Douglas RG, Gevaert PH, Hafner A, Harvey RJ, Joos GF, Kalogjera L, Knill A, Kocks JH, Landis BN, Limpens J, Lebeer S, Lourenco O, Meco C, Matricardi PM, O'Mahony L, Philpott CM, Ryan D, Schlosser R, Senior B, Smith TL, Teeling T, Tomazic PV, Wang DY, Wang D, Zhang L, Agius AM, Ahlstrom-Emanuelsson C, Alabri R, Albu S, Alhabash S, Aleksic A, Aloulah M, Al-Qudah M, Alsaleh S, Baban MA, Baudoin T, Balvers T, Battaglia P, Bedoya JD, Beule A, Bofares KM, Braverman I, Brozek-Madry E, Richard B, Callejas C, Carrie S, Caulley L, Chussi D, de Corso E, Coste A, El Hadi U, Elfarouk A, Eloy PH, Farrokhi S, Felisati G, Ferrari MD, Fishchuk R, Grayson W, Goncalves PM, Grdinic B, Grgic V, Hamizan AW, Heinichen JV, Husain S, Ping TI, Ivaska J, Jakimovska F, Jovancevic L, Kakande E, Kamel R, Karpischenko S, Kariyawasam HH, Kawauchi H, Kjeldsen A, Klimek L, Krzeski A, Kopacheva Barsova G, Kim SW, Lal D, Letort JJ, Lopatin A, Mahdjoubi A, Mesbahi A, Netkovski J, Nyenbue Tshipukane D, Obando-Valverde A, Okano M, Onerci M, Ong YK, Orlandi R, Otori N, Ouennoughy K, Ozkan M, Peric A, Plzak J, Prokopakis E, Prepageran N, Psaltis A, Pugin B, Raftopulos M, Rombaux P, Riechelmann H, Sahtout S, Sarafoleanu CC, Searyoh K, Rhee CS, Shi J, Shkoukani M, Shukuryan AK, Sicak M, Smyth D, Sindvongs K, Soklic Kosak T, Stjarne P, Sutikno B, Steinsvag S, Tantilipikorn P, Thanaviratananich S, Tran T, Urbancic J, Valiulius A, Vasquez de Aparicio C, Vicheva D, Virkkula PM, Vicente G, Voegels R, Wagenmann MM, Wardani RS, Welge-Lussen A, Witterick I, Wright E, Zabolotniy D, Zsolt B, Zwetsloot CP. European Position Paper on Rhinosinusitis and Nasal Polyps 2020. Rhinology 2020; 58:1-464. [PMID: 32077450 DOI: 10.4193/rhin20.600] [Citation(s) in RCA: 660] [Impact Index Per Article: 132.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012. The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings. EPOS2020 contains chapters on definitions and classification where we have defined a large number of terms and indicated preferred terms. A new classification of CRS into primary and secondary CRS and further division into localized and diffuse disease, based on anatomic distribution is proposed. There are extensive chapters on epidemiology and predisposing factors, inflammatory mechanisms, (differential) diagnosis of facial pain, allergic rhinitis, genetics, cystic fibrosis, aspirin exacerbated respiratory disease, immunodeficiencies, allergic fungal rhinosinusitis and the relationship between upper and lower airways. The chapters on paediatric acute and chronic rhinosinusitis are totally rewritten. All available evidence for the management of acute rhinosinusitis and chronic rhinosinusitis with or without nasal polyps in adults and children is systematically reviewed and integrated care pathways based on the evidence are proposed. Despite considerable increases in the amount of quality publications in recent years, a large number of practical clinical questions remain. It was agreed that the best way to address these was to conduct a Delphi exercise . The results have been integrated into the respective sections. Last but not least, advice for patients and pharmacists and a new list of research needs are included. The full document can be downloaded for free on the website of this journal: http://www.rhinologyjournal.com.
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Practice Guideline |
5 |
660 |
5
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Abstract
The methylotrophic yeast Pichia pastoris is now one of the standard tools used in molecular biology for the generation of recombinant protein. P. pastoris has demonstrated its most powerful success as a large-scale (fermentation) recombinant protein production tool. What began more than 20 years ago as a program to convert abundant methanol to a protein source for animal feed has been developed into what is today two important biological tools: a model eukaryote used in cell biology research and a recombinant protein production system. To date well over 200 heterologous proteins have been expressed in P. pastoris. Significant advances in the development of new strains and vectors, improved techniques, and the commercial availability of these tools coupled with a better understanding of the biology of Pichia species have led to this microbe's value and power in commercial and research labs alike.
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Review |
25 |
608 |
6
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Hussain MM, Shi J, Dreizen P. Microsomal triglyceride transfer protein and its role in apoB-lipoprotein assembly. J Lipid Res 2003; 44:22-32. [PMID: 12518019 DOI: 10.1194/jlr.r200014-jlr200] [Citation(s) in RCA: 423] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Apolipoprotein B (apoB) and microsomal triglyceride transfer protein (MTP) are necessary for lipoprotein assembly. ApoB consists of five structural domains, betaalpha(1)-beta(1)-alpha(2)-beta(2)-alpha(3). We propose that MTP contains three structural motifs (N-terminal beta-barrel, central alpha-helix, and C-terminal lipid cavity) and three functional domains (lipid transfer, membrane associating, and apoB binding). MTP's lipid transfer activity is required for the assembly of lipoproteins. This activity renders nascent apoB secretion-competent and may be involved in the import of triglycerides into the lumen of endoplasmic reticulum. In addition, MTP binds to apoB with high affinity involving ionic interactions. MTP interacts at multiple sites in the N-terminal betaalpha(1) structural domain of apoB. A novel antagonist that inhibits apoB-MTP binding decreases apoB secretion. Furthermore, site-directed mutagenesis and deletion analyses that inhibit apoB-MTP binding decrease apoB secretion. Lipids modulate protein-protein interactions between apoB and MTP. Lipids associated with MTP increase apoB-MTP binding whereas lipids associated with apoB decrease this binding. Thus, specific antagonist, site-directed mutagenesis, deletion analyses, and modulation studies support the notion that apoB-MTP binding plays a role in lipoprotein biogenesis. However, specific steps in lipoprotein assembly that require apoB-MTP binding have not been identified. ApoB-MTP binding may be important for the prevention of degradation and lipidation of nascent apoB.
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Review |
22 |
423 |
7
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Shi J, Le Maguer M. Lycopene in tomatoes: chemical and physical properties affected by food processing. Crit Rev Food Sci Nutr 2000; 40:1-42. [PMID: 10674200 DOI: 10.1080/10408690091189275] [Citation(s) in RCA: 372] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Lycopene is the pigment principally responsible for the characteristic deep-red color of ripe tomato fruits and tomato products. It has attracted attention due to its biological and physicochemical properties, especially related to its effects as a natural antioxidant. Although it has no provitamin A activity, lycopene does exhibit a physical quenching rate constant with singlet oxygen almost twice as high as that of beta-carotene. This makes its presence in the diet of considerable interest. Increasing clinical evidence supports the role of lycopene as a micronutrient with important health benefits, because it appears to provide protection against a broad range of epithelial cancers. Tomatoes and related tomato products are the major source of lycopene compounds, and are also considered an important source of carotenoids in the human diet. Undesirable degradation of lycopene not only affects the sensory quality of the final products, but also the health benefit of tomato-based foods for the human body. Lycopene in fresh tomato fruits occurs essentially in the all-trans configuration. The main causes of tomato lycopene degradation during processing are isomerization and oxidation. Isomerization converts all-trans isomers to cis-isomers due to additional energy input and results in an unstable, energy-rich station. Determination of the degree of lycopene isomerization during processing would provide a measure of the potential health benefits of tomato-based foods. Thermal processing (bleaching, retorting, and freezing processes) generally cause some loss of lycopene in tomato-based foods. Heat induces isomerization of the all-trans to cis forms. The cis-isomers increase with temperature and processing time. In general, dehydrated and powdered tomatoes have poor lycopene stability unless carefully processed and promptly placed in a hermetically sealed and inert atmosphere for storage. A significant increase in the cis-isomers with a simultaneous decrease in the all-trans isomers can be observed in the dehydrated tomato samples using the different dehydration methods. Frozen foods and heat-sterilized foods exhibit excellent lycopene stability throughout their normal temperature storage shelf life. Lycopene bioavailability (absorption) can be influenced by many factors. The bioavailability of cis-isomers in food is higher than that of all-trans isomers. Lycopene bioavailability in processed tomato products is higher than in unprocessed fresh tomatoes. The composition and structure of the food also have an impact on the bioavailability of lycopene and may affect the release of lycopene from the tomato tissue matrix. Food processing may improve lycopene bioavailability by breaking down cell walls, which weakens the bonding forces between lycopene and tissue matrix, thus making lycopene more accessible and enhancing the cis-isomerization. More information on lycopene bioavailability, however, is needed. The pharmacokinetic properties of lycopene remain particularly poorly understood. Further research on the bioavalability, pharmacology, biochemistry, and physiology must be done to reveal the mechanism of lycopene in human diet, and the in vivo metabolism of lycopene. Consumer demand for healthy food products provides an opportunity to develop lycopene-rich food as new functional foods, as well as food-grade and pharmaceutical-grade lycopene as new nutraceutical products. An industrial scale, environmentally friendly lycopene extraction and purification procedure with minimal loss of bioactivities is highly desirable for the foods, feed, cosmetic, and pharmaceutical industries. High-quality lycopene products that meet food safety regulations will offer potential benefits to the food industry.
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Review |
25 |
372 |
8
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Arnold RS, Shi J, Murad E, Whalen AM, Sun CQ, Polavarapu R, Parthasarathy S, Petros JA, Lambeth JD. Hydrogen peroxide mediates the cell growth and transformation caused by the mitogenic oxidase Nox1. Proc Natl Acad Sci U S A 2001; 98:5550-5. [PMID: 11331784 PMCID: PMC33250 DOI: 10.1073/pnas.101505898] [Citation(s) in RCA: 360] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nox1, a homologue of gp91phox, the catalytic moiety of the superoxide (O(2)(-))-generating NADPH oxidase of phagocytes, causes increased O(2)(-) generation, increased mitotic rate, cell transformation, and tumorigenicity when expressed in NIH 3T3 fibroblasts. This study explores the role of reactive oxygen species (ROS) in regulating cell growth and transformation by Nox1. H(2)O(2) concentration increased approximately 10-fold in Nox1-expressing cells, compared with <2-fold increase in O(2)(-). When human catalase was expressed in Nox1-expressing cells, H(2)O(2) concentration decreased, and the cells reverted to a normal appearance, the growth rate normalized, and cells no longer produced tumors in athymic mice. A large number of genes, including many related to cell cycle, growth, and cancer (but unrelated to oxidative stress), were expressed in Nox1-expressing cells, and more than 60% of these returned to normal levels on coexpression of catalase. Thus, H(2)O(2) in low concentrations functions as an intracellular signal that triggers a genetic program related to cell growth.
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research-article |
24 |
360 |
9
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Shi J, Gider S, Babcock K, Awschalom DD. Magnetic Clusters in Molecular Beams, Metals, and Semiconductors. Science 1996. [DOI: 10.1126/science.271.5251.937] [Citation(s) in RCA: 252] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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29 |
252 |
10
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Chen CH, Shi J, Tang CW. Recent developments in molecular organic electroluminescent materials. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19981250102] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14 |
216 |
11
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Shyn SI, Shi J, Kraft JB, Potash JB, Knowles JA, Weissman MM, Garriock HA, Yokoyama JS, McGrath PJ, Peters EJ, Scheftner WA, Coryell W, Lawson WB, Jancic D, Gejman PV, Sanders AR, Holmans P, Slager SL, Levinson DF, Hamilton SP. Novel loci for major depression identified by genome-wide association study of Sequenced Treatment Alternatives to Relieve Depression and meta-analysis of three studies. Mol Psychiatry 2011; 16:202-15. [PMID: 20038947 PMCID: PMC2888856 DOI: 10.1038/mp.2009.125] [Citation(s) in RCA: 207] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 08/20/2009] [Accepted: 08/27/2009] [Indexed: 01/11/2023]
Abstract
We report a genome-wide association study (GWAS) of major depressive disorder (MDD) in 1221 cases from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study and 1636 screened controls. No genome-wide evidence for association was detected. We also carried out a meta-analysis of three European-ancestry MDD GWAS data sets: STAR*D, Genetics of Recurrent Early-onset Depression and the publicly available Genetic Association Information Network-MDD data set. These data sets, totaling 3957 cases and 3428 controls, were genotyped using four different platforms (Affymetrix 6.0, 5.0 and 500 K, and Perlegen). For each of 2.4 million HapMap II single-nucleotide polymorphisms (SNPs), using genotyped data where available and imputed data otherwise, single-SNP association tests were carried out in each sample with correction for ancestry-informative principal components. The strongest evidence for association in the meta-analysis was observed for intronic SNPs in ATP6V1B2 (P=6.78 x 10⁻⁷), SP4 (P=7.68 x 10⁻⁷) and GRM7 (P=1.11 x 10⁻⁶). Additional exploratory analyses were carried out for a narrower phenotype (recurrent MDD with onset before age 31, N=2191 cases), and separately for males and females. Several of the best findings were supported primarily by evidence from narrow cases or from either males or females. On the basis of previous biological evidence, we consider GRM7 a strong MDD candidate gene. Larger samples will be required to determine whether any common SNPs are significantly associated with MDD.
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Research Support, N.I.H., Extramural |
14 |
207 |
12
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Shi J, Potash JB, Knowles JA, Weissman MM, Coryell W, Scheftner WA, Lawson WB, DePaulo JR, Gejman PV, Sanders AR, Johnson JK, Adams P, Chaudhury S, Jancic D, Evgrafov O, Zvinyatskovskiy A, Ertman N, Gladis M, Neimanas K, Goodell M, Hale N, Ney N, Verma R, Mirel D, Holmans P, Levinson DF. Genome-wide association study of recurrent early-onset major depressive disorder. Mol Psychiatry 2011; 16:193-201. [PMID: 20125088 PMCID: PMC6486400 DOI: 10.1038/mp.2009.124] [Citation(s) in RCA: 205] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 08/20/2009] [Accepted: 08/27/2009] [Indexed: 01/07/2023]
Abstract
A genome-wide association study was carried out in 1020 case subjects with recurrent early-onset major depressive disorder (MDD) (onset before age 31) and 1636 control subjects screened to exclude lifetime MDD. Subjects were genotyped with the Affymetrix 6.0 platform. After extensive quality control procedures, 671 424 autosomal single nucleotide polymorphisms (SNPs) and 25 068 X chromosome SNPs with minor allele frequency greater than 1% were available for analysis. An additional 1 892 186 HapMap II SNPs were analyzed based on imputed genotypic data. Single-SNP logistic regression trend tests were computed, with correction for ancestry-informative principal component scores. No genome-wide significant evidence for association was observed, assuming that nominal P<5 × 10(-8) approximates a 5% genome-wide significance threshold. The strongest evidence for association was observed on chromosome 18q22.1 (rs17077540, P=1.83 × 10(-7)) in a region that has produced some evidence for linkage to bipolar-I or -II disorder in several studies, within an mRNA detected in human brain tissue (BC053410) and approximately 75 kb upstream of DSEL. Comparing these results with those of a meta-analysis of three MDD GWAS data sets reported in a companion article, we note that among the strongest signals observed in the GenRED sample, the meta-analysis provided the greatest support (although not at a genome-wide significant level) for association of MDD to SNPs within SP4, a brain-specific transcription factor. Larger samples will be required to confirm the hypothesis of association between MDD (and particularly the recurrent early-onset subtype) and common SNPs.
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Research Support, N.I.H., Extramural |
14 |
205 |
13
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Shi J, Le Maguer M. Lycopene in tomatoes: chemical and physical properties affected by food processing. Crit Rev Biotechnol 2001; 20:293-334. [PMID: 11192026 DOI: 10.1080/07388550091144212] [Citation(s) in RCA: 201] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Lycopene is the pigment principally responsible for the characteristic deep-red color of ripe tomato fruits and tomato products. It has attracted attention due to its biological and physicochemical properties, especially related to its effects as a natural antioxidant. Although it has no provitamin A activity, lycopene does exhibit a physical quenching rate constant with singlet oxygen almost twice as high as that of beta-carotene. This makes its presence in the diet of considerable interest. Increasing clinical evidence supports the role of lycopene as a micronutrient with important health benefits, because it appears to provide protection against a broad range of epithelial cancers. Tomatoes and related tomato products are the major source of lycopene compounds, and are also considered an important source of carotenoids in the human diet. Undesirable degradation of lycopene not only affects the sensory quality of the final products, but also the health benefit of tomato-based foods for the human body. Lycopene in fresh tomato fruits occurs essentially in the all-trans configuration. The main causes of tomato lycopene degradation during processing are isomerization and oxidation. Isomerization converts all-trans isomers to cis-isomers due to additional energy input and results in an unstable, energy-rich station. Determination of the degree of lycopene isomerization during processing would provide a measure of the potential health benefits of tomato-based foods. Thermal processing (bleaching, retorting, and freezing processes) generally cause some loss of lycopene in tomato-based foods. Heat induces isomerization of the all-trans to cis forms. The cis-isomers increase with temperature and processing time. In general, dehydrated and powdered tomatoes have poor lycopene stability unless carefully processed and promptly placed in a hermetically sealed and inert atmosphere for storage. A significant increase in the cis-isomers with a simultaneous decrease in the all-trans isomers can be observed in the dehydrated tomato samples using the different dehydration methods. Frozen foods and heat-sterilized foods exhibit excellent lycopene stability throughout their normal temperature storage shelf life. Lycopene bioavailability (absorption) can be influenced by many factors. The bioavailability of cis-isomers in food is higher than that of all-trans isomers. Lycopene bioavailability in processed tomato products is higher than in unprocessed fresh tomatoes. The composition and structure of the food also have an impact on the bioavailability of lycopene and may affect the release of lycopene from the tomato tissue matrix. Food processing may improve lycopene bioavailability by breaking down cell walls, which weakens the bonding forces between lycopene and tissue matrix, thus making lycopene more accessible and enhancing the cis-isomerization. More information on lycopene bioavailability, however, is needed. The pharmacokinetic properties of lycopene remain particularly poorly understood. Further research on the bioavalability, pharmacology, biochemistry, and physiology must be done to reveal the mechanism of lycopene in human diet, and the in vivo metabolism of lycopene. Consumer demand for healthy food products provides an opportunity to develop lycopene-rich food as new functional foods, as well as food-grade and pharmaceutical-grade lycopene as new nutraceutical products. An industrial scale, environmentally friendly lycopene extraction and purification procedure with minimal loss of bioactivities is highly desirable for the foods, feed, cosmetic, and pharmaceutical industries. High-quality lycopene products that meet food safety regulations will offer potential benefits to the food industry.
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Review |
24 |
201 |
14
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Ravi V, Catha M, D'Addario L, Djorgovski SG, Hallinan G, Hobbs R, Kocz J, Kulkarni SR, Shi J, Vedantham HK, Weinreb S, Woody DP. A fast radio burst localized to a massive galaxy. Nature 2019; 572:352-354. [PMID: 31266051 DOI: 10.1038/s41586-019-1389-7] [Citation(s) in RCA: 195] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 06/25/2019] [Indexed: 11/09/2022]
Abstract
Intense, millisecond-duration bursts of radio waves (named fast radio bursts) have been detected from beyond the Milky Way1. Their dispersion measures-which are greater than would be expected if they had propagated only through the interstellar medium of the Milky Way-indicate extragalactic origins and imply contributions from the intergalactic medium and perhaps from other galaxies2. Although several theories exist regarding the sources of these fast radio bursts, their intensities, durations and temporal structures suggest coherent emission from highly magnetized plasma3,4. Two of these bursts have been observed to repeat5,6, and one repeater (FRB 121102) has been localized to the largest star-forming region of a dwarf galaxy at a cosmological redshift of 0.19 (refs. 7-9). However, the host galaxies and distances of the hitherto non-repeating fast radio bursts are yet to be identified. Unlike repeating sources, these events must be observed with an interferometer that has sufficient spatial resolution for arcsecond localization at the time of discovery. Here we report the localization of a fast radio burst (FRB 190523) to a few-arcsecond region containing a single massive galaxy at a redshift of 0.66. This galaxy is different from the host of FRB 121102, as it is a thousand times more massive, with a specific star-formation rate (the star-formation rate divided by the mass) a hundred times smaller.
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Research Support, Non-U.S. Gov't |
6 |
195 |
15
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Shi J, Aisaki K, Ikawa Y, Wake K. Evidence of hepatocyte apoptosis in rat liver after the administration of carbon tetrachloride. THE AMERICAN JOURNAL OF PATHOLOGY 1998; 153:515-25. [PMID: 9708811 PMCID: PMC1852991 DOI: 10.1016/s0002-9440(10)65594-0] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In acute liver injury induced by the injection of CCl4, cell death has been attributed to the necrosis of hepatocytes in the centrilobular area. In the present study, we re-examined the hepatic injury evoked by CCl4 in rats and explored the possibility that apoptosis may also contribute to its pathogenesis. Apoptotic hepatocytes were identified and quantified by light and electron microscopy, the in situ immunohistochemical labeling of nuclear DNA fragmentation, flow cytometry, and DNA gel electrophoresis. We found that a substantial number of hepatocytes underwent apoptosis. Apoptotic changes were also observed in ballooned hepatocytes. Apoptotic hepatocytes increased in number at 3 hours and peaked at 6 hours after the CCl4 injection. Apoptotic bodies were sequestrated in the adjacent hepatocytes and sinusoidal cells. Double staining of the cells with immunostaining for phagocytes and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining for labeling of DNA fragmentation showed that the majority of apoptotic hepatocytes were phagocytosed by Kupffer cells and macrophages. The results indicated that apoptosis occurs in the ballooned and injured hepatocytes of the centrilobular area. What occurs after CCl4 administration may be important in reducing inflammation, shortening the course of acute hepatic injury, and preventing the development of fibrosis.
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Yang SH, Shi J, Day AL, Simpkins JW. Estradiol exerts neuroprotective effects when administered after ischemic insult. Stroke 2000; 31:745-9; discussion 749-50. [PMID: 10700514 DOI: 10.1161/01.str.31.3.745] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE 17beta-Estradiol (E2) has been reported to exert neuroprotective effects when administered before an ischemic insult. This study was designed to determine whether E2 treatment after ischemia exerts the same effects and, if so, how long this therapeutic window remains open, and whether the effects are related to changes in cerebral blood flow (CBF). METHODS Female Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO). In protocol 1, E2 was administered (100 microg/kg IV followed immediately by subcutaneous implantation of crystalline E2 in a silicone elastomer tube) to ovariectomized females (OVX+E2) at 0.5 (n=8), 1 (n=6), 2 (n=7), 3 (n=6), or 4 (n=9) hours after MCAO. Intact (INT; n=6) and ovariectomized females (OVX; n=12) were subjected to MCAO and received vehicle instead of E2. Two days after MCAO the animals were killed, and ischemic lesion volume was determined by 2,3,5-triphenyltetrazolium chloride staining. In protocol 2, CBF was monitored before and at 1, 24, and 48 hours in a group of animals receiving E2 or vehicle 0.5 hour after ischemia induction (INT, n=6; OVX, n=8; OVX+E2, n=6). RESULTS Lesion volume was 20.9+/-2.2% and 21.8+/-1.2% in the INT and OVX groups, respectively. E2 was found to decrease lesion volume significantly when administered within 3 hours after MCAO. The lesion volumes were 6.3+/-0.5%, 10.3+/-2.1%, 11.8+/-1.8%, 13.5+/-1.6%, and 17.9+/-2.8% when E2 was administered at 0.5, 1, 2, 3, or 4 hours after MCAO, respectively. CBF decreased to 43.1+/-2.2% and 25.4+/-1.0% in the INT and OVX animals, respectively, at 5 minutes after MCAO. In comparison to OVX rats, CBF was not different at 1 hour after E2 administration but was increased significantly in the OVX+E2 group 1 and 2 days after E2 administration. CONCLUSIONS E2 exerts neuroprotective effects when administered after ischemia, with a therapeutic window in a permanent focal cerebral ischemia model of approximately 3 hours. This effect of estradiol was associated with no immediate change in blood flow but with a delayed increase in CBF.
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Mukhopadhyay R, Shi J, Rosen BP. Purification and characterization of ACR2p, the Saccharomyces cerevisiae arsenate reductase. J Biol Chem 2000; 275:21149-57. [PMID: 10801893 DOI: 10.1074/jbc.m910401199] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Saccharomyces cerevisiae, expression of the ACR2 and ACR3 genes confers arsenical resistance. Acr2p is the first identified eukaryotic arsenate reductase. It reduces arsenate to arsenite, which is then extruded from cells by Acr3p. In this study, we demonstrate that ACR2 complemented the arsenate-sensitive phenotype of an arsC deletion in Escherichia coli. ACR2 was cloned into a bacterial expression vector and expressed in E. coli as a C-terminally histidine-tagged protein that was purified by sequential metal chelate affinity and gel filtration chromatography. Acr2p purified as a homodimer of 34 kDa. The purified protein was shown to catalyze the reduction of arsenate to arsenite. Enzymatic activity as a function of arsenate concentration exhibited an apparent positive cooperativity with an apparent Hill coefficient of 2.7. Activity required GSH and glutaredoxin as the source of reducing equivalents. Thioredoxin was unable to support arsenate reduction. However, glutaredoxins from both S. cerevisiae and E. coli were able to serve as reductants. Analysis of grx mutants lacking one or both cysteine residues in the Cys-Pro-Tyr-Cys active site demonstrated that only the N-terminal cysteine residue is essential for arsenate reductase activity. This suggests that during the catalytic cycle, Acr2p forms a mixed disulfide with GSH before being reduced by glutaredoxin to regenerate the active Acr2p reductase.
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Zhang YQ, Shi J, Rajakumar G, Day AL, Simpkins JW. Effects of gender and estradiol treatment on focal brain ischemia. Brain Res 1998; 784:321-4. [PMID: 9518671 DOI: 10.1016/s0006-8993(97)00502-7] [Citation(s) in RCA: 171] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The present studies were undertaken to investigate the effects of gender and estrogen treatment on focal cerebral ischemia in male and female rats. Focal ischemia was created by inserting a 3-0 surgical suture through the left cervical internal carotid artery to obstruct the blood flow into the middle cerebral artery (MCA). The MCA was reperfused by removing the suture in 40 min. All rats were sacrificed for measurement of infarct area after 24 h. In the first study, mortalities from MAC occlusion were 12.5% (2/16) each for intact male rats and intact female rats, and 23.5% (4/17) for ovariectomized (OVX) female rats. The coronal infarct area (mean+/-S. E.M.) was 9.5+/-1.0% for intact female rats, 16.6+/-1.6% for intact male rats (p=0.0001 vs. intact female rats), and 16.0+/-1.4% for OVX female rats (p=0.0002 vs. intact female rats). In a second experiment, OVX-female rats were administrated either 17beta-estradiol (E2) or its vehicle, hydroxypropyl-beta-cyclodextrin (HPCD), at 40 min after the onset of MCA occlusion. Mortalities were 40% (4/10) for vehicle treated OVX rats and 0% for E2 treated OVX rats. The coronal infarct area (mean+/-S.E.M.) was 19.3+/-1.8% for vehicle treated rats vs. 8.0+/-1. 2% for E2 treated rats (p<0.01). Serum estrogen levels for vehicle treated OVX rats were 14.5+/-1.2% pg/ml vs. 142.7+/-23.6 pg/ml for E2 treated OVX rats (p<0.01). These results strongly suggest that the level of circulating estrogens play an important role in protecting brain tissues against ischemia induced by MCA occlusion.
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Ceglarek D, Shi J. Fixture Failure Diagnosis for Autobody Assembly Using Pattern Recognition. ACTA ACUST UNITED AC 1996. [DOI: 10.1115/1.2803648] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this paper, a fault diagnostic method is proposed for autobody assembly fixtures. This method uses measurement data to detect and isolate dimensional faults of part caused by fixture. The proposed method includes a predetermined variation pattern model and a fault mapping procedure. The variation pattern model is based on CAD information about the fixture geometry and location of the measurement points. This fault mapping procedure combines Principal Component Analysis with pattern recognition approach. Simulations and one case study illustrate the proposed method.
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Shi J, Ross CR, Leto TL, Blecha F. PR-39, a proline-rich antibacterial peptide that inhibits phagocyte NADPH oxidase activity by binding to Src homology 3 domains of p47 phox. Proc Natl Acad Sci U S A 1996; 93:6014-8. [PMID: 8650211 PMCID: PMC39180 DOI: 10.1073/pnas.93.12.6014] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Reactive oxygen intermediates generated by the phagocyte NADPH oxidase are critically important components of host defense. However, these highly toxic oxidants can cause significant tissue injury during inflammation; thus, it is essential that their generation and inactivation are tightly regulated. We show here that an endogenous proline-arginine (PR)-rich antibacterial peptide, PR-39, inhibits NADPH oxidase activity by blocking assembly of this enzyme through interactions with Src homology 3 domains of a cytosolic component. This neutrophil-derived peptide inhibited oxygen-dependent microbicidal activity of neutrophils in whole cells and in a cell-free assay of NADPH oxidase. Both oxidase inhibitory and direct antimicrobial activities were defined within the amino-terminal 26 residues of PR-39. Oxidase inhibition was attributed to binding of PR-39 to the p47phox cytosolic oxidase component. Its effects involve both a polybasic amino-terminal segment and a proline-rich core region of PR-39 that binds to the p47phox Src homology 3 domains and, thereby, inhibits interaction with the small subunit of cytochrome b558, p22phox. These findings suggest that PR-39, which has been shown to be involved in tissue repair processes, is a multifunctional peptide that can regulate NADPH oxidase production of superoxide anion O2-. thus limiting excessive tissue damage during inflammation.
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Shi J, Zhu L, Liu S, Xie WF. A meta-analysis of case-control studies on the combined effect of hepatitis B and C virus infections in causing hepatocellular carcinoma in China. Br J Cancer 2005; 92:607-12. [PMID: 15685242 PMCID: PMC2362087 DOI: 10.1038/sj.bjc.6602333] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We investigated whether concurrent infection by hepatitis B virus (HBV) and hepatitis C virus (HCV) in China, a hyperepidemic area for these infections, was associated with a higher risk of causing hepatocellular carcinoma (HCC) than each infection alone in a meta-analysis in China, 32 case–control studies involving 3201 cases and 4005 controls, identified from a computer-based literature search from 1966 to 2004. The pooled odds ratio and 95% confidence interval (CI) for HBsAg positivity was 14.1 (95% CI: 10.6–18.8); for anti-HCV/HCV RNA positivity was 4.6 (95% CI: 3.6–5.9); for HBsAg positivity and anti-HCV/HCV RNA negativity were 15.6 (95% CI: 11.5–21.3); for HBsAg negativity and anti-HCV/HCV RNA positivity were 8.1 (95% CI: 5.0–13.0); and positivity for both HBsAg and anti-HCV/HCV RNA was 35.7 (95% CI: 26.2–48.5). We conclude that HBV and HCV infections are important independent risk factors for HCC in China, and that dual infection by HBV and HCV is associated with a higher risk of causing HCC than each infection alone, suggesting a synergism between HBV and HCV.
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Carroll KM, Ball SA, Nich C, O'Connor PG, Eagan DA, Frankforter TL, Triffleman EG, Shi J, Rounsaville BJ. Targeting behavioral therapies to enhance naltrexone treatment of opioid dependence: efficacy of contingency management and significant other involvement. ARCHIVES OF GENERAL PSYCHIATRY 2001; 58:755-61. [PMID: 11483141 PMCID: PMC3651594 DOI: 10.1001/archpsyc.58.8.755] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Contingency management (CM) and significant other involvement (SO) were evaluated as strategies to enhance treatment retention, medication compliance, and outcome for naltrexone treatment of opioid dependence. METHODS One hundred twenty-seven recently detoxified opioid-dependent individuals were randomly assigned to 1 of 3 conditions delivered for 12 weeks: (1) standard naltrexone treatment, given 3 times a week; (2) naltrexone treatment plus contingency management (CM), with delivery of vouchers contingent on naltrexone compliance and drug-free urine specimens; or (3) naltrexone treatment, CM, plus significant other involvement (SO), where a family member was invited to participate in up to 6 family counseling sessions. Principal outcomes were retention in treatment, compliance with naltrexone therapy, and number of drug-free urine specimens. RESULTS First, CM was associated with significant improvements in treatment retention (7.4 vs 5.6 weeks; P =.05) and in reduction in opioid use (19 vs 14 opioid-free urine specimens; P =.04) compared with standard naltrexone treatment. Second, assignment to SO did not significantly improve retention, compliance, or substance abuse outcomes compared with CM. Significant effects for the SO condition over CM on retention, compliance, and drug use outcomes were seen only for the subgroup who attended at least 1 family counseling session. The SO condition was associated with significant (P =.02) improvements in family functioning. CONCLUSION Behavioral therapies, such as CM, can be targeted to address weaknesses of specific pharmacotherapies, such as noncompliance, and thus can play a substantial role in broadening the utility of available pharmacotherapies.
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Yu O, Jung W, Shi J, Croes RA, Fader GM, McGonigle B, Odell JT. Production of the isoflavones genistein and daidzein in non-legume dicot and monocot tissues. PLANT PHYSIOLOGY 2000; 124:781-94. [PMID: 11027726 PMCID: PMC59182 DOI: 10.1104/pp.124.2.781] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2000] [Accepted: 07/31/2000] [Indexed: 05/18/2023]
Abstract
Metabolic engineering for production of isoflavones in non-legume plants may provide the health benefits of these phytoestrogens from consumption of more widely used grains. In legumes, isoflavones function in both the symbiotic relationship with rhizobial bacteria and the plant defense response. Expression of a soybean isoflavone synthase (IFS) gene in Arabidopsis plants was previously shown to result in the synthesis and accumulation of the isoflavone genistein in leaf and stem tissue (Jung et al., 2000). Here we further investigate the ability of the heterologous IFS enzyme to interact with the endogenous phenylpropanoid pathway, which provides the substrate for IFS, and produces genistein in several plant tissue systems. In tobacco (Nicotiana tabacum) floral tissue that synthesizes anthocyanins, genistein production was increased relative to leaves. Induction of the flavonoid/anthocyanin branch of the phenylpropanoid pathway through UV-B treatment also enhanced genistein production in Arabidopsis. In a monocot cell system, introduced expression of a transcription factor regulating genes of the anthocyanin pathway was effective in conferring the ability to produce genistein in the presence of the IFS gene. Introduction of a third gene, chalcone reductase, provided the ability to synthesize an additional substrate of IFS resulting in production of the isoflavone daidzein in this system. The genistein produced in tobacco, Arabidopsis, and maize (Zea mays) cells was present in conjugated forms, indicating that endogenous enzymes were capable of recognizing genistein as a substrate. This study provides insight into requirements for metabolic engineering for isoflavone production in non-legume dicot and monocot tissues.
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Ge J, Li Y, Qian J, Shi J, Wang Q, Niu Y, Fan B, Liu X, Zhang S, Sun A, Zou Y. Efficacy of emergent transcatheter transplantation of stem cells for treatment of acute myocardial infarction (TCT-STAMI). Heart 2006; 92:1764-7. [PMID: 16775089 PMCID: PMC1861266 DOI: 10.1136/hrt.2005.085431] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE To study whether emergent intracoronary autologous bone marrow cell transplantation (BMT) is applicable for the treatment of acute myocardial infarction (AMI). METHODS 20 patients admitted within 24 h after the onset of a first AMI were randomly allocated to receive intracoronary autologous BMT (n = 10) or bone marrow supernatant (controls, n = 10) immediately after primary percutaneous coronary intervention. Left ventricular ejection fraction (LVEF), left ventricular end diastolic internal diameter (LVDd) and myocardial perfusion defect scores were examined respectively by echocardiography and single-photon emission computed tomography at one week and six months after AMI. RESULTS From one week to six months after AMI, LVEF was enhanced from mean 53.8 (SD 9.2)% to 58.6 (9.9)% (p < 0.05) in the BMT group but was unchanged in the control group (58.2 (7.5)% v 56.3 (3.5)%, p > 0.05); LVDd remained unchanged (52.5 (2.8) v 52.1 (3.2) mm, p > 0.05) in the BMT group but was significantly enlarged in the control group (50.4 (6.0) v 55.2 (7.1) mm, p < 0.05). Additionally, myocardial perfusion defect scores decreased from 21 (11) to 13 (10) (p < 0.01) in the BMT group but were unchanged in the control group (20 (14) v 17 (15), p > 0.05). CONCLUSION Emergent intracoronary transplantation of bone marrow mononuclear cells after AMI is practicable, and it improved cardiac function, prevented myocardial remodelling and increased myocardial perfusion at six months' follow up.
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Shcherban TY, Shi J, Durachko DM, Guiltinan MJ, McQueen-Mason SJ, Shieh M, Cosgrove DJ. Molecular cloning and sequence analysis of expansins--a highly conserved, multigene family of proteins that mediate cell wall extension in plants. Proc Natl Acad Sci U S A 1995; 92:9245-9. [PMID: 7568110 PMCID: PMC40961 DOI: 10.1073/pnas.92.20.9245] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Expansins are unusual proteins discovered by virtue of their ability to mediate cell wall extension in plants. We identified cDNA clones for two cucumber expansins on the basis of peptide sequences of proteins purified from cucumber hypocotyls. The expansin cDNAs encode related proteins with signal peptides predicted to direct protein secretion to the cell wall. Northern blot analysis showed moderate transcript abundance in the growing region of the hypocotyl and no detectable transcripts in the nongrowing region. Rice and Arabidopsis expansin cDNAs were identified from collections of anonymous cDNAs (expressed sequence tags). Sequence comparisons indicate at least four distinct expansin cDNAs in rice and at least six in Arabidopsis. Expansins are highly conserved in size and sequence (60-87% amino acid sequence identity and 75-95% similarity between any pairwise comparison), and phylogenetic trees indicate that this multigene family formed before the evolutionary divergence of monocotyledons and dicotyledons. Sequence and motif analyses show no similarities to known functional domains that might account for expansin action on wall extension. A series of highly conserved tryptophans may function in expansin binding to cellulose or other glycans. The high conservation of this multigene family indicates that the mechanism by which expansins promote wall extensin tolerates little variation in protein structure.
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