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Liu WT, Marsh TL, Cheng H, Forney LJ. Characterization of microbial diversity by determining terminal restriction fragment length polymorphisms of genes encoding 16S rRNA. Appl Environ Microbiol 1997; 63:4516-22. [PMID: 9361437 PMCID: PMC168770 DOI: 10.1128/aem.63.11.4516-4522.1997] [Citation(s) in RCA: 1123] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A quantitative molecular technique was developed for rapid analysis of microbial community diversity in various environments. The technique employed PCR in which one of the two primers used was fluorescently labeled at the 5' end and was used to amplify a selected region of bacterial genes encoding 16S rRNA from total community DNA. The PCR product was digested with restriction enzymes, and the fluorescently labeled terminal restriction fragment was precisely measured by using an automated DNA sequencer. Computer-simulated analysis of terminal restriction fragment length polymorphisms (T-RFLP) for 1,002 eubacterial sequences showed that with proper selection of PCR primers and restriction enzymes, 686 sequences could be PCR amplified and classified into 233 unique terminal restriction fragment lengths or "ribotypes." Using T-RFLP, we were able to distinguish all bacterial strains in a model bacterial community, and the pattern was consistent with the predicted outcome. Analysis of complex bacterial communities with T-RFLP revealed high species diversity in activated sludge, bioreactor sludge, aquifer sand, and termite guts; as many as 72 unique ribotypes were found in these communities, with 36 ribotypes observed in the termite guts. The community T-RFLP patterns were numerically analyzed and hierarchically clustered. The pattern derived from termite guts was found to be distinctly different from the patterns derived from the other three communities. Overall, our results demonstrated that T-RFLP is a powerful tool for assessing the diversity of complex bacterial communities and for rapidly comparing the community structure and diversity of different ecosystems.
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research-article |
28 |
1123 |
2
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Park Y, Albright KJ, Liu W, Storkson JM, Cook ME, Pariza MW. Effect of conjugated linoleic acid on body composition in mice. Lipids 1997; 32:853-8. [PMID: 9270977 DOI: 10.1007/s11745-997-0109-x] [Citation(s) in RCA: 762] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effects of conjugated linoleic acid (CLA) on body composition were investigated. ICR mice were fed a control diet containing 5.5% corn oil or a CLA-supplemented diet (5.0% corn oil plus 0.5% CLA). Mice fed CLA-supplemented diet exhibited 57% and 60% lower body fat and 5% and 14% increased lean body mass relative to controls (P < 0.05). Total carnitine palmitoyltransferase activity was increased by dietary CLA supplementation in both fat pad and skeletal muscle; the differences were significant for fat pad of fed mice and skeletal muscle of fasted mice. In cultured 3T3-L1 adipocytes CLA treatment (1 x 10(-4)M) significantly reduced heparin-releasable lipoprotein lipase activity (-66%) and the intracellular concentrations of triacylglyceride (-8%) and glycerol (-15%), but significantly increased free glycerol in the culture medium (+22%) compared to control (P < 0.05). The effects of CLA on body composition appear to be due in part to reduced fat deposition and increased lipolysis in adipocytes, possibly coupled with enhanced fatty acid oxidation in both muscle cells and adipocytes.
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28 |
762 |
3
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Katzman R, Zhang MY, Ouang-Ya-Qu, Wang ZY, Liu WT, Yu E, Wong SC, Salmon DP, Grant I. A Chinese version of the Mini-Mental State Examination; impact of illiteracy in a Shanghai dementia survey. J Clin Epidemiol 1988; 41:971-8. [PMID: 3193141 DOI: 10.1016/0895-4356(88)90034-0] [Citation(s) in RCA: 704] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A dementia screening survey was carried out in Shanghai using a culturally adapted Chinese version of the Mini-Mental State Examination. A probability sample of 5055 community-dwelling elderly in Shanghai was surveyed, 1497 aged 55-64, 2187 aged 65-74, and 1371 aged 75 and over. In the 73.3% of the subjects who had gone to school, using the age and education adjustments suggested by Kittner et al. (1986), [Kittner et al. J Chron Dis 39: 163-170; 1986] suitable cutoff scores could readily be selected to identify the subjects who should be examined intensively for the presence of dementia. However, in the 26.7% who had not gone to school, there was a significant increase in low scores on the mental status test as well as a different error pattern, reflecting the lack of formal education. Methods for following cognitive changes in illiterate individuals need further development.
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Comparative Study |
37 |
704 |
4
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Vaughan JT, Garwood M, Collins CM, Liu W, DelaBarre L, Adriany G, Andersen P, Merkle H, Goebel R, Smith MB, Ugurbil K. 7T vs. 4T: RF power, homogeneity, and signal-to-noise comparison in head images. Magn Reson Med 2001; 46:24-30. [PMID: 11443707 DOI: 10.1002/mrm.1156] [Citation(s) in RCA: 636] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Signal-to-noise ratio (SNR), RF field (B(1)), and RF power requirement for human head imaging were examined at 7T and 4T magnetic field strengths. The variation in B(1) magnitude was nearly twofold higher at 7T than at 4T ( approximately 42% compared to approximately 23%). The power required for a 90 degrees pulse in the center of the head at 7T was approximately twice that at 4T. The SNR averaged over the brain was at least 1.6 times higher at 7T compared to 4T. These experimental results were consistent with calculations performed using a human head model and Maxwell's equations. Magn Reson Med 46:24-30, 2001.
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Comparative Study |
24 |
636 |
5
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Park Y, Storkson JM, Albright KJ, Liu W, Pariza MW. Evidence that the trans-10,cis-12 isomer of conjugated linoleic acid induces body composition changes in mice. Lipids 1999; 34:235-41. [PMID: 10230716 DOI: 10.1007/s11745-999-0358-8] [Citation(s) in RCA: 543] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We investigated the effects of conjugated linoleic acid (CLA) preparations, which were enriched for the cis-9,trans-11 CLA isomer or the trans-10,cis-12 CLA isomer, on body composition in mice. Body composition changes (reduced body fat, enhanced body water, enhanced body protein, and enhanced body ash) were associated with feeding the trans-10,cis-12 CLA isomer. In cultured 3T3-L1 adipocytes, the trans-10,cis-12 isomer reduced lipoprotein lipase activity, intracellular triacylglycerol and glycerol, and enhanced glycerol release into the medium. By contrast, the cis-9,trans-11 and trans-9,trans-11 CLA isomers did not affect these biochemical activities. We conclude that CLA-associated body composition change results from feeding the trans-10,cis-12 isomer.
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26 |
543 |
6
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Roberds SL, Anderson J, Basi G, Bienkowski MJ, Branstetter DG, Chen KS, Freedman SB, Frigon NL, Games D, Hu K, Johnson-Wood K, Kappenman KE, Kawabe TT, Kola I, Kuehn R, Lee M, Liu W, Motter R, Nichols NF, Power M, Robertson DW, Schenk D, Schoor M, Shopp GM, Shuck ME, Sinha S, Svensson KA, Tatsuno G, Tintrup H, Wijsman J, Wright S, McConlogue L. BACE knockout mice are healthy despite lacking the primary beta-secretase activity in brain: implications for Alzheimer's disease therapeutics. Hum Mol Genet 2001; 10:1317-24. [PMID: 11406613 DOI: 10.1093/hmg/10.12.1317] [Citation(s) in RCA: 529] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by accumulation of amyloid plaques and neurofibrillary tangles in the brain. The major components of plaque, beta-amyloid peptides (Abetas), are produced from amyloid precursor protein (APP) by the activity of beta- and gamma-secretases. beta-secretase activity cleaves APP to define the N-terminus of the Abeta1-x peptides and, therefore, has been a long- sought therapeutic target for treatment of AD. The gene encoding a beta-secretase for beta-site APP cleaving enzyme (BACE) was identified recently. However, it was not known whether BACE was the primary beta-secretase in mammalian brain nor whether inhibition of beta-secretase might have effects in mammals that would preclude its utility as a therapeutic target. In the work described herein, we generated two lines of BACE knockout mice and characterized them for pathology, beta-secretase activity and Abeta production. These mice appeared to develop normally and showed no consistent phenotypic differences from their wild-type littermates, including overall normal tissue morphology and brain histochemistry, normal blood and urine chemistries, normal blood-cell composition, and no overt behavioral and neuromuscular effects. Brain and primary cortical cultures from BACE knockout mice showed no detectable beta-secretase activity, and primary cortical cultures from BACE knockout mice produced much less Abeta from APP. The findings that BACE is the primary beta-secretase activity in brain and that loss of beta-secretase activity produces no profound phenotypic defects with a concomitant reduction in beta-amyloid peptide clearly indicate that BACE is an excellent therapeutic target for treatment of AD.
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24 |
529 |
7
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Liu J, Xiao H, Lei F, Zhu Q, Qin K, Zhang XW, Zhang XL, Zhao D, Wang G, Feng Y, Ma J, Liu W, Wang J, Gao GF. Highly pathogenic H5N1 influenza virus infection in migratory birds. Science 2005; 309:1206. [PMID: 16000410 DOI: 10.1126/science.1115273] [Citation(s) in RCA: 509] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
H5N1 avian influenza virus (AIV) has emerged as a pathogenic entity for a variety of species, including humans, in recent years. Here we report an outbreak among migratory birds on Lake Qinghaihu, China, in May and June 2005, in which more than a thousand birds were affected. Pancreatic necrosis and abnormal neurological symptoms were the major clinical features. Sequencing of the complete genomes of four H5N1 AIV strains revealed them to be reassortants related to a peregrine falcon isolate from Hong Kong and to have known highly pathogenic characteristics. Experimental animal infections reproduced typical highly pathogenic AIV infection symptoms and pathology.
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Research Support, Non-U.S. Gov't |
20 |
509 |
8
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Liu W, Flytzanistephanopoulos M. Total Oxidation of Carbon Monoxide and Methane over Transition Metal Fluorite Oxide Composite Catalysts. J Catal 1995. [DOI: 10.1006/jcat.1995.1132] [Citation(s) in RCA: 494] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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30 |
494 |
9
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Irwin M, Marin MC, Phillips AC, Seelan RS, Smith DI, Liu W, Flores ER, Tsai KY, Jacks T, Vousden KH, Kaelin WG. Role for the p53 homologue p73 in E2F-1-induced apoptosis. Nature 2000; 407:645-8. [PMID: 11034215 DOI: 10.1038/35036614] [Citation(s) in RCA: 454] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The transcription factor E2F-1 induces both cell-cycle progression and, in certain settings, apoptosis. E2F-1 uses both p53-dependent and p53-independent pathways to kill cells. The p53-dependent pathway involves the induction by E2F-1 of the human tumour-suppressor protein p14ARF, which neutralizes HDM2 (human homologue of MDM2) and thereby stabilizes the p53 protein. Here we show that E2F-1 induces the transcription of the p53 homologue p73. Disruption of p73 function inhibited E2F-1-induced apoptosis in p53-defective tumour cells and in p53-/- mouse embryo fibroblasts. We conclude that activation of p73 provides a means for E2F-1 to induce death in the absence of p53.
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25 |
454 |
10
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Ichikawa K, Liu W, Zhao L, Wang Z, Liu D, Ohtsuka T, Zhang H, Mountz JD, Koopman WJ, Kimberly RP, Zhou T. Tumoricidal activity of a novel anti-human DR5 monoclonal antibody without hepatocyte cytotoxicity. Nat Med 2001; 7:954-60. [PMID: 11479629 DOI: 10.1038/91000] [Citation(s) in RCA: 424] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A novel anti-human DR5 monoclonal antibody, TRA-8, induces apoptosis of most tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-sensitive tumor cells both in vitro and in vivo. In contrast to both the membrane-bound form of human TRAIL, which induced severe hepatitis in mice, and the soluble form of human TRAIL, which induced apoptosis of normal human hepatocytes in vitro, TRA-8 did not induce significant cell death of normal human hepatocytes. However, both primary hepatocellular carcinoma cells and an established liver cancer cell line were highly susceptible to the killing mediated by TRA-8. We show here that elevated levels of cell-surface expression of DR5 and increased susceptibility to DR5-mediated apoptosis are characteristics of malignant tumor cells. In contrast, DR5 alone is not sufficient to trigger apoptosis of normal hepatocytes. Therefore, selective, specific targeting of DR5 with an agonistic antibody might be a safe and effective strategy for cancer therapy.
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24 |
424 |
11
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Liu W, Dong X, Mai M, Seelan RS, Taniguchi K, Krishnadath KK, Halling KC, Cunningham JM, Boardman LA, Qian C, Christensen E, Schmidt SS, Roche PC, Smith DI, Thibodeau SN. Mutations in AXIN2 cause colorectal cancer with defective mismatch repair by activating beta-catenin/TCF signalling. Nat Genet 2000; 26:146-7. [PMID: 11017067 DOI: 10.1038/79859] [Citation(s) in RCA: 379] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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25 |
379 |
12
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Nakatani K, Thompson DA, Barthel A, Sakaue H, Liu W, Weigel RJ, Roth RA. Up-regulation of Akt3 in estrogen receptor-deficient breast cancers and androgen-independent prostate cancer lines. J Biol Chem 1999; 274:21528-32. [PMID: 10419456 DOI: 10.1074/jbc.274.31.21528] [Citation(s) in RCA: 364] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We measured the insulin-stimulated amount of Akt1, Akt2, and Akt3 enzymatic activities in four breast cancer cell lines and three prostate cancer cell lines. In the estrogen receptor-deficient breast cancer cells and the androgen-insensitive prostate cells, the amount of Akt3 enzymatic activity was approximately 20-60-fold higher than in the cells that were estrogen- or androgen-responsive. In contrast, the levels of Akt1 and -2 were not increased in these cells. The increase in Akt3 enzyme activity correlated with an increase in both Akt3 mRNA and protein. In a prostate cancer cell line lacking the tumor suppressor PTEN (a lipid and protein phosphatase), the basal enzymatic activity of Akt3 was constitutively elevated and represented the major active Akt in these cells. Finally, reverse transcription-PCR was used to examine the Akt3 expression in 27 primary breast carcinomas. The expression levels of Akt3 were significantly higher in the estrogen receptor-negative tumors in comparison to the estrogen receptor-positive tumors. To see if the increase in Akt3 could be due to chromosomal abnormalities, the Akt3 gene was assigned to human chromosome 1q44 by fluorescence in situ hybridization and radiation hybrid cell panel analyses. These results indicate that Akt3 may contribute to the more aggressive clinical phenotype of the estrogen receptor-negative breast cancers and androgen-insensitive prostate carcinomas.
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MESH Headings
- Breast Neoplasms/enzymology
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- Chromosome Mapping
- Chromosomes, Human, Pair 1
- Female
- Gene Expression Regulation, Neoplastic
- Genes, Tumor Suppressor
- Humans
- In Situ Hybridization, Fluorescence
- Male
- Oncogene Proteins/genetics
- Oncogene Proteins/metabolism
- Prostatic Neoplasms/enzymology
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/pathology
- Protein Biosynthesis
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-akt
- RNA, Messenger/genetics
- Receptors, Estrogen/deficiency
- Receptors, Estrogen/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription, Genetic
- Tumor Cells, Cultured
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26 |
364 |
13
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Ye C, Liu W, Chen Y, Yu L. Room-temperature ionic liquids: a novel versatile lubricant. Chem Commun (Camb) 2001:2244-5. [PMID: 12240132 DOI: 10.1039/b106935g] [Citation(s) in RCA: 355] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alkylimidazolium tetrafluoroborates are promising versatile lubricants for the contact of steel/steel, steel/aluminium, steel/copper, steel/SiO2, Si3N4/SiO2, steel/Si(100), steel/sialon ceramics and Si3N4/sialon ceramics; they show excellent friction reduction, antiwear performance and high load-carrying capacity.
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24 |
355 |
14
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Liu W, Toyosawa S, Furuichi T, Kanatani N, Yoshida C, Liu Y, Himeno M, Narai S, Yamaguchi A, Komori T. Overexpression of Cbfa1 in osteoblasts inhibits osteoblast maturation and causes osteopenia with multiple fractures. J Cell Biol 2001; 155:157-66. [PMID: 11581292 PMCID: PMC2150799 DOI: 10.1083/jcb.200105052] [Citation(s) in RCA: 345] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Targeted disruption of core binding factor alpha1 (Cbfa1) showed that Cbfa1 is an essential transcription factor in osteoblast differentiation and bone formation. Furthermore, both in vitro and in vivo studies showed that Cbfa1 plays important roles in matrix production and mineralization. However, it remains to be clarified how Cbfa1 controls osteoblast differentiation, bone formation, and bone remodelling. To understand fully the physiological functions of Cbfa1, we generated transgenic mice that overexpressed Cbfa1 in osteoblasts using type I collagen promoter. Unexpectedly, Cbfa1 transgenic mice showed osteopenia with multiple fractures. Cortical bone, which was thin, porous, and enriched with osteopontin, was invaded by osteoclasts, despite the absence of acceleration of osteoclastogenesis. Although the number of neonatal osteoblasts was increased, their function was impaired in matrix production and mineralization. Furthermore, terminally differentiated osteoblasts, which strongly express osteocalcin, and osteocytes were diminished greatly, whereas less mature osteoblasts expressing osteopontin accumulated in adult bone. These data indicate that immature organization of cortical bone, which was caused by the maturational blockage of osteoblasts, led to osteopenia and fragility in transgenic mice, demonstrating that Cbfa1 inhibits osteoblast differentiation at a late stage.
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research-article |
24 |
345 |
15
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Jiang Y, Woronicz JD, Liu W, Goeddel DV. Prevention of constitutive TNF receptor 1 signaling by silencer of death domains. Science 1999; 283:543-6. [PMID: 9915703 DOI: 10.1126/science.283.5401.543] [Citation(s) in RCA: 290] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Tumor necrosis factor receptor type 1 (TNF-R1) contains a cytoplasmic death domain that is required for the signaling of TNF activities such as apoptosis and nuclear factor kappa B (NF-kappaB) activation. Normally, these signals are generated only after TNF-induced receptor aggregation. However, TNF-R1 self-associates and signals independently of ligand when overexpressed. This apparent paradox may be explained by silencer of death domains (SODD), a widely expressed approximately 60-kilodalton protein that was found to be associated with the death domain of TNF-R1. TNF treatment released SODD from TNF-R1, permitting the recruitment of proteins such as TRADD and TRAF2 to the active TNF-R1 signaling complex. SODD also interacted with death receptor-3 (DR3), another member of the TNF receptor superfamily. Thus, SODD association may be representative of a general mechanism for preventing spontaneous signaling by death domain-containing receptors.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Sequence
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Apoptosis
- Carrier Proteins/chemistry
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Line
- Fas-Associated Death Domain Protein
- Humans
- Jurkat Cells
- Molecular Sequence Data
- Mutation
- NF-kappa B/metabolism
- Protein Binding
- Proteins/metabolism
- Receptor Aggregation
- Receptor-Interacting Protein Serine-Threonine Kinases
- Receptors, Tumor Necrosis Factor/chemistry
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/metabolism
- Receptors, Tumor Necrosis Factor, Member 25
- Receptors, Tumor Necrosis Factor, Type I
- Recombinant Fusion Proteins/metabolism
- Signal Transduction
- TNF Receptor-Associated Factor 1
- TNF Receptor-Associated Factor 2
- Transfection
- Tumor Necrosis Factor-alpha/pharmacology
- U937 Cells
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26 |
290 |
16
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Smalla K, Wachtendorf U, Heuer H, Liu WT, Forney L. Analysis of BIOLOG GN Substrate Utilization Patterns by Microbial Communities. Appl Environ Microbiol 1998; 64:1220-5. [PMID: 16349535 PMCID: PMC106132 DOI: 10.1128/aem.64.4.1220-1225.1998] [Citation(s) in RCA: 286] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT
BIOLOG GN plates are increasingly used to characterize microbial communities by determining the ability of the communities to oxidize various carbon sources. Studies were done to determine whether the BIOLOG GN plate assay accurately reflects the catabolic potential of the inoculum used. To gain insight into which populations of microbial communities contribute to the BIOLOG patterns, denaturing gradient gel electrophoresis and temperature gradient gel electrophoresis (TGGE) were used to assess the diversity of ribotypes in the inocula and individual wells of BIOLOG plates following incubation. These studies were done with microbial communities from the rhizosphere of potatoes and an activated sludge reactor fed with glucose and peptone. TGGE analyses of BIOLOG wells inoculated with cell suspensions from the potato rhizosphere revealed that, compared with the inoculum, there was a decrease in the number of 16S rRNA gene fragments obtained from various wells, as well as a concomitant loss of populations that had been numerically dominant in the inoculum. The dominant fragments in TGGE gels could be assigned to the γ subclass of the class
Proteobacteria
, suggesting that fast-growing bacteria adapted to high substrate concentrations were numerically dominant in the wells and may have been primarily responsible for the patterns of substrate use that were observed. Similarly, the community structure changed in wells inoculated with cells from activated sludge; one or more populations were enriched, but all dominant populations of the inoculum could be detected in at least one well. This study showed that carbon source utilization profiles obtained with BIOLOG GN plates do not necessarily reflect the functional potential of the numerically dominant members of the microbial community used as the inoculum.
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27 |
286 |
17
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Sullivan PF, Lin D, Tzeng JY, van den Oord E, Perkins D, Stroup TS, Wagner M, Lee S, Wright FA, Zou F, Liu W, Downing AM, Lieberman J, Close SL. Genomewide association for schizophrenia in the CATIE study: results of stage 1. Mol Psychiatry 2008; 13:570-84. [PMID: 18347602 PMCID: PMC3910086 DOI: 10.1038/mp.2008.25] [Citation(s) in RCA: 282] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 01/07/2008] [Accepted: 01/11/2008] [Indexed: 02/07/2023]
Abstract
Little is known for certain about the genetics of schizophrenia. The advent of genomewide association has been widely anticipated as a promising means to identify reproducible DNA sequence variation associated with this important and debilitating disorder. A total of 738 cases with DSM-IV schizophrenia (all participants in the CATIE study) and 733 group-matched controls were genotyped for 492,900 single-nucleotide polymorphisms (SNPs) using the Affymetrix 500K two-chip genotyping platform plus a custom 164K fill-in chip. Following multiple quality control steps for both subjects and SNPs, logistic regression analyses were used to assess the evidence for association of all SNPs with schizophrenia. We identified a number of promising SNPs for follow-up studies, although no SNP or multimarker combination of SNPs achieved genomewide statistical significance. Although a few signals coincided with genomic regions previously implicated in schizophrenia, chance could not be excluded. These data do not provide evidence for the involvement of any genomic region with schizophrenia detectable with moderate sample size. However, a planned genomewide association study for response phenotypes and inclusion of individual phenotype and genotype data from this study in meta-analyses hold promise for eventual identification of susceptibility and protective variants.
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Randomized Controlled Trial |
17 |
282 |
18
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Lee SC, Dickson DW, Liu W, Brosnan CF. Induction of nitric oxide synthase activity in human astrocytes by interleukin-1 beta and interferon-gamma. J Neuroimmunol 1993; 46:19-24. [PMID: 7689587 DOI: 10.1016/0165-5728(93)90229-r] [Citation(s) in RCA: 265] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Nitric oxide (NO) is a short-lived, diffusible molecule that has a variety of biological activities including vasorelaxation, neurotransmission, and cytotoxicity. In the central nervous system, a constitutive form of nitric oxide synthase (NOS) has been localized in a subset of neurons and in endothelial cells. In addition, both constitutive and LPS-inducible NOS has been demonstrated in rat astrocytes and microglia in vitro. In this report, we present evidence for the production of NO, as measured by the production of nitrite, in highly enriched human fetal astrocyte cultures stimulated with IL-1 beta. The production of nitrite paralleled the induction of NADPH diaphorase enzyme activity in the perikarya of the majority of stimulated astrocytes. The IL-1 beta-induced nitrite production by astrocytes was markedly enhanced when cells were co-stimulated with IFN-gamma or TNF-alpha (IFN-gamma > TNF-alpha); LPS had no effect used as a single agent or in combination with other cytokines. NGMMA and NG-nitro-arginine, competitive inhibitors of NOS, diminished the accumulation of nitrite, but calmodulin antagonists (trifluoperazine, W-5 and W-7) had little or no inhibitory effect. Human fetal microglia, in contrast to astrocytes, failed to secrete significant amounts of nitrite in response to various stimuli. The results demonstrate the presence of an inducible form of NOS in human fetal astrocytes; human microglia, in turn, may control astrocyte NO production by providing IL-1 beta as an activating signal.
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265 |
19
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Burch GH, Gong Y, Liu W, Dettman RW, Curry CJ, Smith L, Miller WL, Bristow J. Tenascin-X deficiency is associated with Ehlers-Danlos syndrome. Nat Genet 1997; 17:104-8. [PMID: 9288108 DOI: 10.1038/ng0997-104] [Citation(s) in RCA: 263] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The tenascins are a family of large extracellular matrix proteins with at least three members: tenascin-X (TNX), tenascin-C (TNC, or cytotactin) and tenascin-R (TN-R, or restrictin). Although the tenascins have been implicated in a number of important cellular processes, no function has been clearly established for any tenascin. We describe a new contiguous-gene syndrome, involving the CYP21B and TNX genes, that results in 21-hydroxylase deficiency and a connective-tissue disorder consisting of skin and joint hyperextensibility, vascular fragility and poor wound healing. The connective tissue findings are typical of the Ehlers-Danlos syndrome (EDS). The abundant expression of TNX in connective tissues is consistent with a role in EDS, and our patient's skin fibroblasts do not synthesize TNX protein in vitro or in vivo. His paternal allele carries a novel deletion arising from recombination between TNX and its partial duplicate gene, XA, which precludes TNX synthesis. Absence of TNX mRNA and protein in the proband, mapping of the TNX gene and HLA typing of this family suggest recessive inheritance of TNX deficiency and connective-tissue disease. Although the precise role of TNX in the pathogenesis of EDS is uncertain, this patient's findings suggest a unique and essential role for TNX in connective-tissue structure and function.
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Case Reports |
28 |
263 |
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Tang XC, Zhang JX, Zhang SY, Wang P, Fan XH, Li LF, Li G, Dong BQ, Liu W, Cheung CL, Xu KM, Song WJ, Vijaykrishna D, Poon LLM, Peiris JSM, Smith GJD, Chen H, Guan Y. Prevalence and genetic diversity of coronaviruses in bats from China. J Virol 2006; 80:7481-90. [PMID: 16840328 PMCID: PMC1563713 DOI: 10.1128/jvi.00697-06] [Citation(s) in RCA: 259] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Coronaviruses can infect a variety of animals including poultry, livestock, and humans and are currently classified into three groups. The interspecies transmissions of coronaviruses between different hosts form a complex ecosystem of which little is known. The outbreak of severe acute respiratory syndrome (SARS) and the recent identification of new coronaviruses have highlighted the necessity for further investigation of coronavirus ecology, in particular the role of bats and other wild animals. In this study, we sampled bat populations in 15 provinces of China and reveal that approximately 6.5% of the bats, from diverse species distributed throughout the region, harbor coronaviruses. Full genomes of four coronavirues from bats were sequenced and analyzed. Phylogenetic analyses of the spike, envelope, membrane, and nucleoprotein structural proteins and the two conserved replicase domains, putative RNA-dependent RNA polymerase and RNA helicase, revealed that bat coronaviruses cluster in three different groups: group 1, another group that includes all SARS and SARS-like coronaviruses (putative group 4), and an independent bat coronavirus group (putative group 5). Further genetic analyses showed that different species of bats maintain coronaviruses from different groups and that a single bat species from different geographic locations supports similar coronaviruses. Thus, the findings of this study suggest that bats may play an integral role in the ecology and evolution of coronaviruses.
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Research Support, Non-U.S. Gov't |
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Jung YD, Kim MS, Shin BA, Chay KO, Ahn BW, Liu W, Bucana CD, Gallick GE, Ellis LM. EGCG, a major component of green tea, inhibits tumour growth by inhibiting VEGF induction in human colon carcinoma cells. Br J Cancer 2001; 84:844-50. [PMID: 11259102 PMCID: PMC2363808 DOI: 10.1054/bjoc.2000.1691] [Citation(s) in RCA: 257] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Catechins are key components of teas that have antiproliferative properties. We investigated the effects of green tea catechins on intracellular signalling and VEGF induction in vitro in serum-deprived HT29 human colon cancer cells and in vivo on the growth of HT29 cells in nude mice. In the in vitro studies, (-)-epigallocatechin gallate (EGCG), the most abundant catechin in green tea extract, inhibited Erk-1 and Erk-2 activation in a dose-dependent manner. However, other tea catechins such as (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epicatechin (EC) did not affect Erk-1 or 2 activation at a concentration of 30 microM. EGCG also inhibited the increase of VEGF expression and promoter activity induced by serum starvation. In the in vivo studies, athymic BALB/c nude mice were inoculated subcutaneously with HT29 cells and treated with daily intraperitoneal injections of EC (negative control) or EGCG at 1.5 mg day(-1)mouse(-1)starting 2 days after tumour cell inoculation. Treatment with EGCG inhibited tumour growth (58%), microvessel density (30%), and tumour cell proliferation (27%) and increased tumour cell apoptosis (1.9-fold) and endothelial cell apoptosis (3-fold) relative to the control condition (P< 0.05 for all comparisons). EGCG may exert at least part of its anticancer effect by inhibiting angiogenesis through blocking the induction of VEGF.
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Piyasirisilp S, McCutchan FE, Carr JK, Sanders-Buell E, Liu W, Chen J, Wagner R, Wolf H, Shao Y, Lai S, Beyrer C, Yu XF. A recent outbreak of human immunodeficiency virus type 1 infection in southern China was initiated by two highly homogeneous, geographically separated strains, circulating recombinant form AE and a novel BC recombinant. J Virol 2000; 74:11286-95. [PMID: 11070028 PMCID: PMC113233 DOI: 10.1128/jvi.74.23.11286-11295.2000] [Citation(s) in RCA: 248] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
New outbreaks of human immunodeficiency virus type 1 (HIV-1) among injecting drug users (IDUs) are spreading in China along heroin trafficking routes. Recently, two separate HIV-1 epidemics among IDUs were reported in Guangxi, Southern China, where partial sequencing of the env gene showed subtype C and circulating recombinant form (CRF) AE. We evaluated five virtually full-length HIV-1 genome sequences from IDUs in Guangxi to determine the genetic diversity and the presence of intersubtype recombinants. Sequence analysis showed two geographically separated, highly homogeneous HIV-1 strains. B/C intersubtype recombinants were found in three IDUs from Baise City, in a mountainous region near the Yunnan-Guangxi border. These were mostly subtype C, with portions of the capsid and reverse transcriptase (RT) genes from subtype B. The subtype B portion of the capsid was located in the N-terminal domain, which has been shown to influence virus core maturation, virus infectivity, and binding to cyclophilin A, whereas the subtype B portion of RT was located in the palm subdomain, which is the active site of the enzyme. These BC recombinants differed from a BC recombinant found in Xinjiang Province in northwestern China. CRF AE strains were found in IDUs from Nanning, the capital of Guangxi, and in IDUs from Pingxiang City near the China-Vietnam border. The AE and BC recombinants were both remarkable for their low interpatient diversity, less than 1% for the full genome. Rapid spread of HIV-1 among IDUs may foster the emergence of highly homogeneous strains, including novel recombinants in regions with multiple subtypes.
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Liu W, Miller BL, Kramer JH, Rankin K, Wyss-Coray C, Gearhart R, Phengrasamy L, Weiner M, Rosen HJ. Behavioral disorders in the frontal and temporal variants of frontotemporal dementia. Neurology 2004; 62:742-8. [PMID: 15007124 PMCID: PMC2367136 DOI: 10.1212/01.wnl.0000113729.77161.c9] [Citation(s) in RCA: 247] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To compare the behavioral features and to investigate the neuroanatomic correlates of behavioral dysfunction in anatomically defined temporal and frontal variants of frontotemporal dementia (tvFTD and fvFTD). METHODS Volumetric measurements of the frontal, anterior temporal, ventromedial frontal cortical (VMFC), and amygdala regions were made in 51 patients with FTD and 20 normal control subjects, as well as 22 patients with Alzheimer disease (AD) who were used as dementia controls. FTD patients were classified as fvFTD or tvFTD based on the relative degree of frontal and anterior temporal volume loss compared with controls. Behavioral symptoms, cerebral volumes, and the relationship between them were examined across groups. RESULTS Both variants of FTD showed significant increases in rates of elation, disinhibition, and aberrant motor behavior compared with AD. The fvFTD group also showed more anxiety, apathy, and eating disorders, and tvFTD showed a higher prevalence of sleep disturbances than AD. The only behaviors that differed significantly between fvFTD and tvFTD were apathy, greater in fvFTD, and sleep disorders, more frequent in tvFTD. FvFTD was associated with greater frontal atrophy and tvFTD was associated with more temporal and amygdala atrophy compared with AD, but both groups showed significant atrophy in the VMFC compared with AD, which was not associated with VMFC atrophy. In FTD, the presence of many of the behavioral disorders was associated with decreased volume in right-hemispheric regions. CONCLUSION FvFTD and tvFTD show many similarities in behavior, which appear to be associated with damage to right frontal and temporal structures.
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Research Support, U.S. Gov't, P.H.S. |
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Park Y, Albright KJ, Storkson JM, Liu W, Cook ME, Pariza MW. Changes in body composition in mice during feeding and withdrawal of conjugated linoleic acid. Lipids 1999; 34:243-8. [PMID: 10230717 DOI: 10.1007/s11745-999-0359-7] [Citation(s) in RCA: 241] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two experiments were conducted. In Experiment 1, 8-wk-old mice were fed control diet or diet supplemented with 0.5% conjugated linoleic acid (CLA) to study the effect of CLA on body composition (CLA: 40.8-41.1% c-9,t-11 isomer, 43.5-44.9% t-10,c-12 isomer). The data for CLA-fed mice vs. controls described parallel but significantly distinct responses for both absolute and relative changes in body fat mass (reduced in CLA-fed mice) and for relative changes in whole body protein and whole body water (both of which were increased in CLA-fed mice). In the CLA-fed mice, the effect on whole body protein appeared to precede the reduction in body fat mass. In Experiment 2, weanling mice were fed control diet or diet supplemented with 0.5% CLA for 4 wk (test group), at which time all mice were fed control diet devoid of added CLA. The test group exhibited significantly reduced body fat and significantly enhanced whole body water relative to controls at the time of diet change. Time trends for changes in relative body composition were described by parallel lines where the test group exhibited significantly less body fat but significantly more whole body protein, whole body water, and whole body ash than controls. Tissue CLA levels declined following the withdrawal of CLA from the diet. In skeletal muscle of mice fed CLA-supplemented diet, the t-10,c-12 isomer was cleared significantly faster than the c-9,t-11 CLA isomer.
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Dickson DW, Liu W, Hardy J, Farrer M, Mehta N, Uitti R, Mark M, Zimmerman T, Golbe L, Sage J, Sima A, D'Amato C, Albin R, Gilman S, Yen SH. Widespread alterations of alpha-synuclein in multiple system atrophy. THE AMERICAN JOURNAL OF PATHOLOGY 1999; 155:1241-51. [PMID: 10514406 PMCID: PMC1867032 DOI: 10.1016/s0002-9440(10)65226-1] [Citation(s) in RCA: 229] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Glial cytoplasmic inclusions (GCI) are the hallmark of multiple system atrophy (MSA), a rare movement disorder frequently associated with autonomic dysfunction. In this study of 21 cases of MSA, GCI were consistently immunoreactive for alpha-synuclein and double-immunostained for ubiquitin and oligodendroglial markers, but not glial fibrillary acidic protein. No statistically significant difference was found in the density of GCI in various brain regions in the two forms of MSA, striatonigral degeneration (SND) and olivopontocerebellar atrophy (OPCA). Postmortem brain samples from 9 cases of MSA were fractionated according to solubility in buffer, Triton-X 100, sodium dodecyl sulfate (SDS), and formic acid, and alpha-synuclein immunoreactivity was measured in Western blots. Total alpha-synuclein immunoreactivity was increased in MSA compared to controls, with no statistically significant difference between SND and OPCA. Most of the increase was due to alpha-synuclein in SDS fractions. In controls this fraction had little or no immunoreactivity. In 7 cases and 4 controls correlations were investigated between quantitative neuropathology and biochemical properties of alpha-synuclein. Surprisingly, the amount of SDS-soluble alpha-synuclein correlated poorly with the number of GCI in adjacent sections. Furthermore, areas with few or no GCI unexpectedly had abundant SDS-soluble alpha-synuclein. These findings provide evidence that modifications of alpha-synuclein in MSA may be more widespread than obvious histopathology. Moreover, these alterations may constitute a biochemical signature for the synucleinopathies.
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