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Fu HS, Tu J, Cao JB, Song P, Reinisch BW, Gallagher DL, Yang B. IMAGE and DMSP observations of a density trough inside the plasmasphere. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009ja015104] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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77
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Tu J, Stoodley M, Morgan M, Storer K, Smee R. Different responses of cavernous malformations and arteriovenous malformations to radiosurgery. J Clin Neurosci 2009; 16:945-9. [DOI: 10.1016/j.jocn.2008.09.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 09/04/2008] [Accepted: 09/14/2008] [Indexed: 10/21/2022]
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78
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Gustavson MD, Welsh A, Jones C, Mayotte J, Tu J, Hopkins J, Rimm D, Christiansen J. Evaluation of the false-negative rate of standardized and quantitative measurement of estrogen receptor (ER) in tissue using AQUA technology. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
567 Background: The discovery of an astoundingly high false negative rate for estrogen receptor (ER) testing in Canada has raised questions about the accuracy and reproducibility of ER testing. One solution would be the introduction of a standardized and reproducible diagnostic test that is easily adaptable in the clinical setting. Here, we have tested the AQUA method of quantitative immunofluorescence for the standardized and reproducible quantification of ER protein expression in tissue. Methods: Quantitative Western blotting was used in conjunction with AQUA analysis to create standard curves for assessment of absolute ER protein concentration in tissue (n = 118). We used standard scoring methods and AQUA analysis to quantify ER protein expression in a large cohort of breast cancer samples (n =669). Results: Using a series of standard curves, we determined that the range of the ER AQUA assay is between 100 pg/μg and 1500 pg/μg total protein. ER protein concentration in breast cancer samples showed an expected unimodal distribution for quantitative assessment of ER. Reproducibility studies of AQUA analysis demonstrated significant instrument-to-instrument (laboratory-to-laboratory) reproducibility for 3 instruments across the range of AQUA scores (average %CV = 1.34; R2>0.99; ANOVA p = 0.67). The same cases were then read and classified by 3 pathologists using the Allred scoring system. Although their concordance is similar to that seen in the literature (Kappa = 0.81, 0.88, and 0.89), pathologist concordance rate is lower than for that observed with AQUA analysis (Kappa = 0.95, 0.96, and 0.97). Importantly, 9.0% of cases showed a change of diagnosis (positive/negative) across 3 pathologists whereas only 2.8% of cases changed classification using AQUA analysis. Additionally, misclassified cases occurred across the entire range of Allred scores, but were restricted to a narrow region defined by the cut-point for AQUA scoring. Conclusions: We have demonstrated that AQUA technology can provide for the standardized and reproducible quantification of ER with a 3 fold reduction in misclassification. This approach has the potential to decrease the problem of false negative tests for ER. [Table: see text]
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Fan L, Tao K, Sun Y, Tu J, Zhu W. Regulation of adult human spermatogonial stem cells proliferation by estradiol in vitro. Fertil Steril 2008. [DOI: 10.1016/j.fertnstert.2008.07.163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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80
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Sun Y, Tao K, Fan L, Tu J, Zhu W. Identification, culture and characterization of adult human spermatogonial stem cells in vitro. Fertil Steril 2008. [DOI: 10.1016/j.fertnstert.2008.07.1681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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81
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Ji J, Zhang S, Shao C, Xu M, Chen S, Lu C, Wang Z, Zhao Z, Fan X, Tu J. Poland's syndrome complicated with breast cancer: mammographic, ultrasonographic, and computed tomographic findings. Acta Radiol 2008; 49:387-90. [PMID: 18415780 DOI: 10.1080/02841850801922904] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Poland's syndrome is a rare congenital anomaly characterized by unilateral chest wall hypoplasia and ipsilateral hand abnormalities. It has been reported in association with various malignancies and other developmental defects. We report here the case of a 58-year-old woman with Poland's syndrome who developed breast cancer in the ipsilateral normal breast. A review of the literature reveals that two studies of breast carcinoma associated with Poland's syndrome have been reported, but this paper is the first example of a carcinoma occurring in an otherwise normal breast associated with Poland's syndrome.
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Wang Z, Li X, Yang Z, He X, Tu J, Zhang T. Effects of aloesin on melanogenesis in pigmented skin equivalents. Int J Cosmet Sci 2008; 30:121-30. [DOI: 10.1111/j.1468-2494.2008.00432.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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83
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Tu J, Tao K, Fan L, Lu G. EL-003 Oestradiol regulates the expression of stem cell factor in human Sertoli cells. Reprod Biomed Online 2008. [DOI: 10.1016/s1472-6483(10)61569-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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84
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Li CX, Li H, Siddique AB, Sivasithamparam K, Salisbury P, Banga SS, Banga S, Chattopadhyay C, Kumar A, Singh R, Singh D, Agnihotri A, Liu SY, Li YC, Tu J, Fu TD, Wang YF, Barbetti MJ. The importance of the type and time of inoculation and assessment in the determination of resistance in Brassia napus and B. juncea to Sclerotinia sclerotiorum. ACTA ACUST UNITED AC 2007. [DOI: 10.1071/ar07094] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Sclerotinia stem rot (SSR) is a significant agricultural problem worldwide. Finding sources of resistance is crucial to the ongoing search for better management of this disease. Brassica germplasm from Australia, China and India was screened for resistance to SSR under Western Australian field conditions following stem inoculation, application of a spray of mycelial suspension, or as a consequence of myceliogenic germination originating from sclerotia resident in soil. Significant differences in response were observed among 53 genotypes using each of the three screening methods. There was a variable impact of the time of inoculation on the disease level depending upon time of assessment post-stem inoculation. However, this impact could be reduced to an insignificant level provided the assessment after stem inoculation was delayed until 3 weeks post-inoculation. The results of these studies indicate that the use of appropriate inoculation and assessment methods could significantly reduce variability in the responses commonly observed in screening for resistance in crop plants against Sclerotinia sclerotiorum.
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Tu J, Zhao X, Cao G, Zhuang D, Zhu T, Tu J. Enhanced cycling stability of LiMn2O4 by surface modification with melting impregnation method. Electrochim Acta 2006. [DOI: 10.1016/j.electacta.2006.04.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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86
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Tu J, Bolla S, Barr J, Miedema J, Li X, Jasti B. Alginate microparticles prepared by spray–coagulation method: Preparation, drug loading and release characterization. Int J Pharm 2005; 303:171-81. [PMID: 16129575 DOI: 10.1016/j.ijpharm.2005.07.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2005] [Revised: 07/05/2005] [Accepted: 07/05/2005] [Indexed: 11/25/2022]
Abstract
A spray-coagulation method was developed for the preparation of large scale of porous alginate microparticles. The effect of three variables on porosity was evaluated: (1) alginate solution concentration (2) the concentration of CaCl2 in the coagulation medium and (3) the ratio of guluronic acid to manuronic acid of the alginate. Methylene blue (MB), a highly water-soluble compound and a practically water-insoluble compound, 4-phenylazoaniline (PAA) were used as the model drugs to study drug loading and release characteristics from alginate microparticles. The release of the model compounds from the microparticles was found to depend upon the release medium. Incomplete in vitro release of both model drugs in deionized (DI) water was observed. The release of MB in simulated gastrointestinal fluid (0.1N HCl) was fast and complete, while the release of PAA was slow in 0.1N HCl and fast in phosphate buffer solution (pH 6.8). Interactions between the model drugs and alginate microparticles were identified from scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) analysis. The results indicated that (1) porous alginate microparticles can be produced by the spray-coagulation method; (2) drugs can be loaded by the adsorption method; (3) and the obtained microparticles may be used for delaying the release of drugs of low water solubility in acidic conditions.
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Datta K, Baisakh N, Thet KM, Tu J, Datta SK. Pyramiding transgenes for multiple resistance in rice against bacterial blight, yellow stem borer and sheath blight. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2002; 106:1-8. [PMID: 12582865 DOI: 10.1007/s00122-002-1014-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2002] [Accepted: 04/10/2002] [Indexed: 05/18/2023]
Abstract
Here we describe the development of transgene-pyramided stable elite rice lines resistant to disease and insect pests by conventional crossing of two transgenic parental lines transformed independently with different genes. The Xa21 gene (resistance to bacterial blight), the Bt fusion gene (for insect resistance) and the chitinase gene (for tolerance of sheath blight) were combined in a single rice line by reciprocal crossing of two transgenic homozygous IR72 lines. F4 plant lines carrying all the genes of interest stably were identified using molecular methods. The identified lines, when exposed to infection caused by Xanthomonas oryzae pv oryzae, showed resistance to bacterial blight. Neonate larval mortality rates of yellow stem borer ( Scirpophaga incertulas) in an insect bioassay of the same identified lines were 100%. The identified line pyramided with different genes to protect against yield loss showed high tolerance of sheath blight disease caused by Rhizoctonia solani.
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Woese CR, Gupta R, Hahn CM, Zillig W, Tu J. The phylogenetic relationships of three sulfur dependent archaebacteria. Syst Appl Microbiol 2001; 5:97-105. [PMID: 11541975 DOI: 10.1016/s0723-2020(84)80054-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Oligonucleotide catalogs have been determined for the 16S ribosomal RNAs of three sulfur dependent (i.e. "thermoacidophilic") archaebacteria--Sulfolobus acidocaldarius, S. solfataricus, and Thermoproteus tenax. The three form a group specifically related to one another, but are only distantly related to the other archaebacteria--i.e. the group comprising the methanogens, extreme halophiles, and (peripherially) the genus Thermoplasma. The three catalogs exhibit two features unique among bacteria: (1) an unusually high number of long pyrimidine runs, and (2) a remarkably high number of (post-transcriptionally) modified nucleotides.
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Kim ES, Caiati JM, Tu J, Nowygrod R, Stolar CJ. Congenital abdominal aortic aneurysm causing renovascular hypertension, cardiomyopathy, and death in a 19-day-old neonate. J Pediatr Surg 2001; 36:1445-9. [PMID: 11528624 DOI: 10.1053/jpsu.2001.26394] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A full-term baby girl who was sent home day of life 2 was admitted to the hospital on day of life 7 for respiratory distress and poor feeding. The child was found to be hypertensive and in heart failure. Further workup led to the diagnosis of a suprarenal abdominal aortic aneurysm, but the infant had deteriorated clinically with heart failure, modest renal failure, renovascular hypertension, and no operative cure. The child died on day of life 20. Early diagnosis and prompt surgical resection are essential to managing this rare and lethal condition.
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Tu J, Wang L, Yang J, Fei H, Li X. Formulation and pharmacokinetic studies of acyclovir controlled-release capsules. Drug Dev Ind Pharm 2001; 27:687-92. [PMID: 11694016 DOI: 10.1081/ddc-100107325] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Acyclovir controlled-release capsules (CRCs) were prepared by a three-step process: (1) melt granulation of acclovir; (2) coating of granules with ethyl-cellulose, (3) incorporation of coated granules into hard gelatin capsules. In vitro release experiments showed that the main factors affecting the release rate were the mean particle size of the actylovir raw material and the amount of coating material applied. Release of acyclovir from the capsules was in accordance with the Higuchi equation. Pharmacokinetic studies in dogs after oral administration of acyclovir controlled-release capsules showed that the formulation was successful in providing slow release of aciclovir and was superior to a commercially available controlled-release formulation.
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Wilson E, Taylor G, Phillips S, Stewart PJ, Dickinson G, Ramsden VR, Teasell RW, Mayo N, Tu J, Elson S, Strauss B. Creating a Canadian stroke system. CMAJ 2001; 164:1853-5. [PMID: 11450282 PMCID: PMC81194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
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92
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Yang YC, Yang MK, Kuo TT, Tu J. Structural and functional characterization of the lexA gene of Xanthomonas campestris pathovar citri. Mol Genet Genomics 2001; 265:316-26. [PMID: 11361343 DOI: 10.1007/s004380000417] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The role of the LexA protein and, specifically, its effect on recA expression were analyzed in Xanthomonas campestris pathovar citri (X.c. pv. citri). Overexpression of LexA from X.c. pv. citri, in the plant pathogen, as well as in Escherichia coli, results in increased sensitivity to the DNA-damaging agents mitomycin C and ultraviolet radiation, indicating that the recombinant X.c. pv. citri LexA protein is functional in a different bacterial species. Immunoblot analysis revealed that the overexpressed LexA protein functioned as a repressor of recA expression in X.c. pv. citri, and that the mitomycin C-induced increase in the abundance of RecA was accompanied by specific proteolysis of LexA that required RecA. Although the LexA protein from X.c. pv. citri also blocked the expression of recA in E. coli, the E. coli RecA protein was not able to support the autocatalytic cleavage of LexA from the plant pathogen. The transcription start site of the X.c. pv. citri lexA gene was identified, and the region upstream of this gene was shown to confer responsiveness to mitomycin C on a luciferase reporter gene construct. Electrophoretic mobility-shift assays demonstrated that X.c. pv. citri LexA interacts with the promoter region of X.c. pv. citri lexA, as well as with those of the recA genes of X.c. pv. citri and E. coli. These results indicate that LexA functions as a repressor of gene expression in X.c. pv. citri just as it does in E. coli.
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Groutas WC, He S, Kuang R, Ruan S, Tu J, Chan HK. Inhibition of serine proteases by functionalized sulfonamides coupled to the 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold. Bioorg Med Chem 2001; 9:1543-8. [PMID: 11408173 DOI: 10.1016/s0968-0896(01)00037-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A challenge associated with drug design is the development of selective inhibitors of proteases (serine or cysteine) that exhibit the same primary substrate specificity, that is, show a preference for the same P(1) residue. While these proteases have similar active sites, nevertheless there are subtle differences in their S and S' subsites which can be exploited. We describe herein for the first time the use of functionalized sulfonamides as a design and diversity element which, when coupled to the 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold yields potent, time-dependent inhibitors of the serine proteases human leukocyte elastase (HLE), proteinase 3 (PR 3) and cathepsin G(Cat G). Our preliminary findings suggest that (a) appending to the 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold recognition and diversity elements that interact with both the S and S' subsites of a target protease may result in optimal enzyme selectivity and potency and, (b) functionalized sulfonamides constitute a powerful design and diversity element with low intrinsic chemical reactivity and potentially wide applicability.
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Chen H, Ling J, Yang G, Tu J. [Recombinant Salmonella typhimurium anticaries vaccine. II. Construction and confirmation of expressing plasmid carrying a region of S. mutans pac gene]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2001; 19:139-41. [PMID: 12539394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE The objective of this study is to construct prokaryotic expressing plasmids carrying A region of S. mutans pac gene. METHODS The A region of pac gene was amplified by using PCR from plasmid pPC41 containing S. mutans surface protein pac gene. The new expression plasmid was constructed by using A region of pac gene and expressing plasmids pET17-b and directed cloning technique. The recombinant plasmid was identified by agarose gel electrophoresis after it was cut by using BamHI and EcoRV. RESULTS The expressing plasmid carrying pac gene A region was acquired. CONCLUSION The recombinant plasmid provides useful experimental materials for further research work.
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Datta K, Tu J, Oliva N, Ona I, Velazhahan R, Mew TW, Muthukrishnan S, Datta SK. Enhanced resistance to sheath blight by constitutive expression of infection-related rice chitinase in transgenic elite indica rice cultivars. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2001; 160:405-414. [PMID: 11166426 DOI: 10.1016/s0168-9452(00)00413-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Genetic transformation has been attempted for management of rice sheath blight disease, caused by Rhizoctonia solani. We introduced a PR-3 rice chitinase gene (RC7), isolated from R. solani-infected rice plants, into indica rice cultivars IR72, IR64, IR68899B, MH63, and Chinsurah Boro II by the biolistic and PEG-mediated transformation system. Inheritance was studied up to the T(2) generation by Southern blot analysis. Western blot analysis of transgenic plants with polyclonal antibody revealed the presence of chitinase protein with a molecular weight of 35 kDa that reacts with chitinase antibody. The transformants synthesized different levels of chitinase proteins constitutively and progeny from the plants containing the chitinase gene showed different levels of enhanced resistance when challenged with the sheath blight pathogen R. solani.
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Groutas WC, Epp JB, Kuang R, Ruan S, Chong LS, Venkataraman R, Tu J, He S, Yu H, Fu Q, Li YH, Truong TM, Vu NT. 1,2,5-Thiadiazolidin-3-one 1,1 Dioxide: A Powerful Scaffold for Probing the S′ Subsites of (Chymo)trypsin-Like Serine Proteases. Arch Biochem Biophys 2001; 385:162-9. [PMID: 11361013 DOI: 10.1006/abbi.2000.2139] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold (I) embodies a motif that allows it to dock to the active site of (chymo)trypsin-like proteases in a predictable and substrate-like fashion. Consequently, inhibitors derived from this heterocyclic scaffold interact with both the S and S' subsites of an enzyme. Exploitation of binding interactions with both the S and S' subsites of a target enzyme may lead to compounds with greatly enhanced enzyme selectivity and inhibitory potency. This preliminary report describes the use of a series of compounds having the heterocyclic scaffold linked to various amino acids to probe the S' subsites of human leukocyte elastase (HLE), proteinase 3 (PR 3), and cathepsin G (Cat G). For comparative purposes, a series of compounds derived from a related scaffold, isothiazolidin-3-one 1,1 dioxide (II), was also generated. Several of the compounds were found to be highly potent and selective time-dependent inhibitors of HLE, PR 3, and Cat G.
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Tu J, Zhang G, Datta K, Xu C, He Y, Zhang Q, Khush GS, Datta SK. Field performance of transgenic elite commercial hybrid rice expressing bacillus thuringiensis delta-endotoxin. Nat Biotechnol 2000; 18:1101-4. [PMID: 11017051 DOI: 10.1038/80310] [Citation(s) in RCA: 343] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Here we describe development of transgenic elite rice lines expressing a Bt fusion gene derived from cryIA(b) and cryIA(c) under the control of rice actinI promoter. The lines used in the study were indica CMS restorer line of Minghui 63 and its derived hybrid rice Shanyou 63. The level of Bt fusion protein CryIA(b)/CryIA(c) detected in Minghui 63 (T51-1) plants was 20 ng/mg soluble protein. The Bt Shanyou 63 was field-tested in natural and repeated heavy manual infestation of two lepidopteran insects, leaffolder and yellow stem borer. The transgenic hybrid plants showed high protection against both insect pests without reduced yield.
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Tu J, Karasavvas N, Heaney ML, Vera JC, Golde DW. Molecular characterization of a granulocyte macrophage-colony-stimulating factor receptor alpha subunit-associated protein, GRAP. Blood 2000; 96:794-9. [PMID: 10910889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The granulocyte macrophage-colony-stimulating factor receptor (GM-CSF-R) is a heterodimer composed of 2 subunits, alpha and beta, and ligand binding to the high-affinity receptor leads to signalling for the multiple actions of GM-CSF on target cells. In order to explore the role of the alpha subunit in signalling, we used a yeast-2-hybrid system to identify proteins interacting with the intracellular domain of the GMR-alpha. A cDNA encoding a predicted protein of 198 amino acids, designated GRAP (GM-CSF receptor alpha subunit-associated protein), was isolated in experiments using the intracellular portion of GMR-alpha as bait. The interaction between GRAP and GMR-alpha was confirmed by coimmunoprecipitation in mammalian cells. GRAP mRNA is widely expressed in normal human and mouse tissues and in neoplastic human cell lines, but it is not restricted to cells or tissues that express GM-CSF receptors. Three discrete GRAP mRNA species were detected in human tissues and cells, with estimated sizes of 3.3, 3.1, and 1.3 kb. GRAP is highly conserved throughout evolution, and homologues are found in yeast. The GRAP locus in Saccharomyces cerevisiae was disrupted, and mutant yeast cells showed an inappropriate stress response under normal culture conditions, manifested by early accumulation of glycogen during the logarithmic growth phase. GRAP is, therefore, a highly conserved and widely expressed protein that binds to the intracellular domain of GMR-alpha, and it appears to play an important role in cellular metabolism.
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He S, Kuang R, Venkataraman R, Tu J, Truong TM, Chan HK, Groutas WC. Potent inhibition of serine proteases by heterocyclic sulfide derivatives of 1,2,5-thiadiazolidin-3-one 1,1 dioxide. Bioorg Med Chem 2000; 8:1713-7. [PMID: 10976518 DOI: 10.1016/s0968-0896(00)00101-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The existence of subtle differences in the Sn' subsites of closely-related (chymo)trypsin-like serine proteases, and the fact that the 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold docks to the active site of (chymo)trypsin-like enzymes in a substrate-like fashion, suggested that the introduction of recognition elements that can potentially interact with the Sn' subsites of these proteases might provide an effective means for optimizing enzyme potency and selectivity. Accordingly, a series of heterocyclic sulfide derivatives based on the 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold (I) was synthesized and the inhibitory activity and selectivity of these compounds toward human leukocyte elastase (HLE), proteinase 3 (PR 3) and cathepsin G (Cat G) were then determined. Compounds with P1 = isobutyl were found to be potent, time-dependent inhibitors of HLE and, to a lesser extent PR 3, while those with P1 = benzyl inactivated Cat G rapidly and irreversibly. This study has demonstrated that 1,2,5-thiadiazolidin-3-one 1,1 dioxide-based heterocyclic sulfides are effective inhibitors of (chymo)trypsin-like serine proteases.
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Kuang R, Epp JB, Ruan S, Chong LS, Venkataraman R, Tu J, He S, Truong TM, Groutas WC. Utilization of the 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold in the design of potent inhibitors of serine proteases: SAR studies using carboxylates. Bioorg Med Chem 2000; 8:1005-16. [PMID: 10882012 DOI: 10.1016/s0968-0896(00)00038-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A series of carboxylate derivatives based on the 1,2,5-thiadiazolidin-3-one 1,1 dioxide and isothiazolidin-3-one 1,1 dioxide scaffolds has been synthesized and the inhibitory profile of these compounds toward human leukocyte elastase (HLE), cathepsin G (Cat G) and proteinase 3 (PR 3) was then determined. Most of the compounds were found to be potent, time-dependent inhibitors of elastase, with some of the compounds exhibiting k(inact)/K1 values as high as 4,928,300 M(-1) s(-1). The inhibitory potency of carboxylate derivatives based on the 1,2,5-thiadiazolidin-3-one 1,1 dioxide platform was found to be influenced by both the pKa and the inherent structure of the leaving group. Proper selection of the primary specificity group (R(I)) was found to lead to selective inhibition of HLE over Cat G, however, those compounds that inhibited HLE also inhibited PR 3, albeit less efficiently. The predictable mode of binding of these compounds suggests that, among closely-related serine proteases, highly selective inhibitors of a particular serine protease can be fashioned by exploiting subtle differences in their S' subsites. This study has also demonstrated that the degradative action of elastase on elastin can be abrogated in the presence of inhibitor 17.
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