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Abbasi RU, Abu-Zayyad T, Amann JF, Archbold G, Bellido JA, Belov K, Belz JW, Bergman DR, Cao Z, Clay RW, Cooper MD, Dai H, Dawson BR, Everett AA, Fedorova YA, Girard JHV, Gray RC, Hanlon WF, Hoffman CM, Holzscheiter MH, Hüntemeyer P, Jones BF, Jui CCH, Kieda DB, Kim K, Kirn MA, Loh EC, Manago N, Marek LJ, Martens K, Martin G, Matthews JAJ, Matthews JN, Meyer JR, Moore SA, Morrison P, Moosman AN, Mumford JR, Munro MW, Painter CA, Perera L, Reil K, Riehle R, Roberts M, Sarracino JS, Sasaki M, Schnetzer SR, Shen P, Simpson KM, Sinnis G, Smith JD, Sokolsky P, Song C, Springer RW, Stokes BT, Taylor SF, Thomas SB, Thompson TN, Thomson GB, Tupa D, Westerhoff S, Wiencke LR, VanderVeen TD, Zech A, Zhang X. Measurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experiment. PHYSICAL REVIEW LETTERS 2004; 92:151101. [PMID: 15169276 DOI: 10.1103/physrevlett.92.151101] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2002] [Revised: 05/28/2003] [Indexed: 05/24/2023]
Abstract
We have measured the cosmic ray spectrum above 10(17.2) eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode. We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors. We fit the spectrum to a model consisting of galactic and extragalactic sources.
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Dandliker PJ, Pratt SD, Nilius AM, Black-Schaefer C, Ruan X, Towne DL, Clark RF, Englund EE, Wagner R, Weitzberg M, Chovan LE, Hickman RK, Daly MM, Kakavas S, Zhong P, Cao Z, David CA, Xuei X, Lerner CG, Soni NB, Bui M, Shen LL, Cai Y, Merta PJ, Saiki AYC, Beutel BA. Novel antibacterial class. Antimicrob Agents Chemother 2004; 47:3831-9. [PMID: 14638491 PMCID: PMC296205 DOI: 10.1128/aac.47.12.3831-3839.2003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the discovery and characterization of a novel ribosome inhibitor (NRI) class that exhibits selective and broad-spectrum antibacterial activity. Compounds in this class inhibit growth of many gram-positive and gram-negative bacteria, including the common respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, and Moraxella catarrhalis, and are nontoxic to human cell lines. The first NRI was discovered in a high-throughput screen designed to identify inhibitors of cell-free translation in extracts from S. pneumoniae. The chemical structure of the NRI class is related to antibacterial quinolones, but, interestingly, the differences in structure are sufficient to completely alter the biochemical and intracellular mechanisms of action. Expression array studies and analysis of NRI-resistant mutants confirm this difference in intracellular mechanism and provide evidence that the NRIs inhibit bacterial protein synthesis by inhibiting ribosomes. Furthermore, compounds in the NRI series appear to inhibit bacterial ribosomes by a new mechanism, because NRI-resistant strains are not cross-resistant to other ribosome inhibitors, such as macrolides, chloramphenicol, tetracycline, aminoglycosides, or oxazolidinones. The NRIs are a promising new antibacterial class with activity against all major drug-resistant respiratory pathogens.
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Cao Z, McAdory BS, Wang Y, Peng H, Martinez JL, Townsel JG. The chemorepellent semaphorin is expressed in the horseshoe crab, Limulus polyphemus. Cell Mol Biol (Noisy-le-grand) 2003; 49:1261-7. [PMID: 14983996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Semaphorins are a family of soluble and membrane-bound proteins that play a critical role in axonal guidance and other processes of neuronal development. Currently, more than twenty semaphorins have been identified, all of which share a conserved 500 amino acid domain near the amino terminus. Semaphorins are divided into eight classes according to species of origin and structural similarities. Classes 1 and 2 are found in invertebrates, classes 3 through 7 are present in vertebrates and viruses encode class V semaphorin. Microarray analysis of Limulus CNS RNA revealed the presence of a semaphorin-like gene in Limulus polyphemus. Based on these data, we aligned 31 different sequences and designed degenerate primers for the consensus domains (WTT/SFLKA) and (DPY/VCA/GW). RT-PCR products were generated using 6 forward primers and 4 reverse primers. The expected size PCR products (750 bp) was obtained and then ligated with pCR II TOPO vector and transferred into E. coli Top 10. Five partial semaphorin cDNAs were found in Limulus: semaphorins 1a, 1b, 2a, 2b and F (now known as 5) were partially cloned. Subsequent Northern blot analyses using these Limulus specific-probes revealed hybridization with total RNAs purified from six different tissues.
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Bonnet F, Cao Z, Cooper ME, Cox AJ, Kelly DJ, Gilbert RE. Tranilast attenuates vascular hypertrophy, matrix accumulation and growth factor overexpression in experimental diabetes. DIABETES & METABOLISM 2003; 29:386-92. [PMID: 14526266 DOI: 10.1016/s1262-3636(07)70049-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVES The growth factors transforming growth factor-B (TGF-B) and epidermal growth factor (EGF) have both been implicated in the hypertrophic structural changes in the vasculature that are characteristic features of both human and experimental diabetes. Recently, tranilast (N(3,4-dimethoxycinnamoyl)anthranilic acid), a drug used in the treatment of allergic and dermatological diseases, has also been reported to inhibit transforming growth factor-B (TGF-B)-mediated collagen formation. However, its effects on vascular hypertrophy in diabetes are unknown. The present study thus sought to determine the effects of tranilast on both TGF-B and EGF expression and mast cells in mediating the trophic vascular changes in experimental diabetes. METHODS Vessel morphology, growth factors and collagen gene expression and matrix deposition were examined in the mesenteric arteries of control rats treated with or without tranilast, and streptozotocin-induced diabetic Sprague-Dawley rats treated with or without tranilast (200 mg/kg/day) during a 3-week period. RESULTS Compared with control animals, diabetic rats had significantly increased vessel weight, wall: lumen ratio, ECM accumulation, gene expression of TGF-B1, EGF, and both alpha1 (I) and alpha1 (IV) collagen. Tranilast treatment did not influence plasma glucose or systemic blood pressure. However, tranilast significantly reduced mesenteric weight, wall: lumen ratio and matrix deposition and also attenuated the overexpression of TGF-B1, EGF, and both alpha1 (I) and alpha1 (IV) collagen mRNA in diabetic rats. CONCLUSION These findings indicate that tranilast ameliorates pathological vascular changes observed in experimental diabetes in association with reduced growth factor expression independent of blood glucose or systemic blood pressure.
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Qian D, Shi Z, Zhang S, Cao Z, Liu W, Li L, Xie Y, Cambournac I, Bonami JR. Extra small virus-like particles (XSV) and nodavirus associated with whitish muscle disease in the giant freshwater prawn, Macrobrachium rosenbergii. JOURNAL OF FISH DISEASES 2003; 26:521-527. [PMID: 14575370 DOI: 10.1046/j.1365-2761.2003.00486.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A disease of Macrobrachium rosenbergii, the giant freshwater prawn, farmed in China was recently recorded in Zhejiang, Jiangsu, Shanghai, Guangxi and Guangdong provinces. The clinical sign of the disease, which develops in post-larvae (PL), is a whitish appearance of the muscles, particularly noticeable in the abdomen. Mortalities may reach 100% in some hatcheries. Investigations by transmission electron microscopy after negative staining of diseased PL homogenates showed the presence of two types of viral particles: one, unenveloped, icosahedral in shape, 26-27 nm in diameter, the second, much smaller, about 14-16 nm in diameter, designated extra small virus particle (XSV). The large virus has a genome with two pieces of ssRNA (RNA-1 and RNA-2), of 3 and 1.2 kb, respectively. Hybridization tests confirmed that this large virus is closely related to M. rosenbergii nodavirus (MrNV) which was isolated from diseased prawns in a hatchery in the French West Indies. Its very small size and hypothesized biochemical and biological characteristics suggest XSV is a new type of crustacean virus. As XSV has always been found associated with the larger virus (nodavirus) and is located in muscle and connective cells of diseased animals, it could be an autonomous virus, a helper-type virus or a satellite-like virus.
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Davis BJ, Johnston CI, Burrell LM, Burns WC, Kubota E, Cao Z, Cooper ME, Allen TJ. Renoprotective effects of vasopeptidase inhibition in an experimental model of diabetic nephropathy. Diabetologia 2003; 46:961-71. [PMID: 12838387 DOI: 10.1007/s00125-003-1121-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2002] [Revised: 12/19/2002] [Indexed: 01/13/2023]
Abstract
AIMS Although ACE inhibitors slow progression of diabetic renal disease, the mortality and morbidity is still high. As other hormonal factors are involved, inhibition of vasopeptidases could further reduce progression. We studied dual inhibition of angiotensin converting enzyme and neutral endopeptidase in a model of progressive diabetic renal injury. The major endpoints were reductions in systemic blood pressure, albuminuria and renal structural injury. METHODS Diabetic spontaneously hypertensive rats were treated with the ACE inhibitor perindopril (mg.kg(-1).day(-1)) or the vasopeptidase inhibitor omapatrilat at doses of 10 (oma10) and 40 (oma40) mg.kg(-1).day(-1) for 32 weeks. In vivo ACE and NEP inhibition was quantitated by in vitro autoradiography. Renal structural injury was assessed by measurement of the glomerulosclerotic (GS) index and tubulointerstitial area (TI). The expression of transforming growth factor beta, beta-inducible gene-h3 and nephrin were also quantitated. RESULTS Despite a similar reduction in blood pressure by perindopril and oma10, greater attenuation of albuminuria was afforded by oma10, with a complete amelioration observed with oma40. Oma40 lead to a 33% reduction in renal NEP binding and this was associated with less albuminuria and prevention of GS, TI area and overexpression of TGFbeta and betaig-h3. Diabetes-associated reduction in nephrin expression was restored by both drugs. CONCLUSION/INTERPRETATION These findings suggest that other vasoactive mechanisms in addition to angiotensin II are important in the prevention of diabetic nephropathy, and that vasopeptidase inhibition might confer an advantage over blockade of the RAS alone in the treatment of diabetic renal disease.
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Cao Z, Carling PA. Mathematical modelling of alluvial rivers: reality and myth. Part 2: Special issues. ACTA ACUST UNITED AC 2002. [DOI: 10.1680/wame.2002.154.4.297] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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208
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Cao Z, Carling PA. Mathematical modelling of alluvial rivers: reality and myth. Part 1: General review. ACTA ACUST UNITED AC 2002. [DOI: 10.1680/wame.2002.154.3.207] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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209
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Ching LM, Cao Z, Kieda C, Zwain S, Jameson MB, Baguley BC. Induction of endothelial cell apoptosis by the antivascular agent 5,6-Dimethylxanthenone-4-acetic acid. Br J Cancer 2002; 86:1937-42. [PMID: 12085190 PMCID: PMC2375421 DOI: 10.1038/sj.bjc.6600368] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2001] [Revised: 04/11/2002] [Accepted: 04/16/2002] [Indexed: 11/24/2022] Open
Abstract
5,6-Dimethylxanthenone-4-acetic acid, synthesised in this laboratory, reduces tumour blood flow, both in mice and in patients on Phase I trial. We used TUNEL (TdT-mediated dUTP nick end labelling) assays to investigate whether apoptosis induction was involved in its antivascular effect. 5,6-Dimethylxanthenone-4-acetic acid induced dose-dependent apoptosis in vitro in HECPP murine endothelial cells in the absence of up-regulation of mRNA for tumour necrosis factor. Selective apoptosis of endothelial cells was detected in vivo in sections of Colon 38 tumours in mice within 30 min of administration of 5,6-Dimethylxanthenone-4-acetic acid (25 mg x kg(-1)). TUNEL staining intensified with time and after 3 h, necrosis of adjacent tumour tissue was observed. Apoptosis of central vessels in splenic white pulp was also detected in tumour-bearing mice but not in mice without tumours. Apoptosis was not observed in liver tissue. No apoptosis was observed with the inactive analogue 8-methylxanthenone-4-acetic acid. Positive TUNEL staining of tumour vascular endothelium was evident in one patient in a Phase I clinical trial, from a breast tumour biopsy taken 3 and 24 h after infusion of 5,6-Dimethylxanthenone-4-acetic acid (3.1 mg x m(-2)). Tumour necrosis and the production of tumour tumour necrosis factor were not observed. No apoptotic staining was seen in tumour biopsies taken from two other patients (doses of 3.7 and 4.9 mg x m(-2)). We conclude that 5,6-Dimethylxanthenone-4-acetic acid can induce vascular endothelial cell apoptosis in some murine and human tumours. The action is rapid and appears to be independent of tumour necrosis factor induction.
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Shortridge VD, Zhong P, Cao Z, Beyer JM, Almer LS, Ramer NC, Doktor SZ, Flamm RK. Comparison of in vitro activities of ABT-773 and telithromycin against macrolide-susceptible and -resistant streptococci and staphylococci. Antimicrob Agents Chemother 2002; 46:783-6. [PMID: 11850262 PMCID: PMC127460 DOI: 10.1128/aac.46.3.783-786.2002] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The activity of a new ketolide, ABT-773, was compared to the activity of the ketolide telithromycin (HMR-3647) against over 600 gram-positive clinical isolates, including 356 Streptococcus pneumoniae, 167 Staphylococcus aureus, and 136 Streptococcus pyogenes isolates. Macrolide-susceptible isolates as well as macrolide-resistant isolates with ribosomal methylase (Erm), macrolide efflux (Mef), and ribosomal mutations were tested using the NCCLS reference broth microdilution method. Both compounds were extremely active against macrolide-susceptible isolates, with the minimum inhibitory concentrations at which 90% of the isolates tested were inhibited (MIC90s) for susceptible streptococci and staphylococci ranging from 0.002 to 0.03 microg/ml for ABT-773 and 0.008 to 0.06 microg/ml for telithromycin. ABT-773 had increased activities against macrolide-resistant S. pneumoniae (Erm MIC90, 0.015 microg/ml; Mef MIC90, 0.12 microg/ml) compared to those of telithromycin (Erm MIC90, 0.12 microg/ml; Mef MIC90, 1 microg/ml). Both compounds were active against strains with rRNA or ribosomal protein mutations (MIC90, 0.12 microg/ml). ABT-773 was also more active against macrolide-resistant S. pyogenes (ABT-773 Erm MIC90, 0.5 microg/ml; ABT-773 Mef MIC90, 0.12 microg/ml; telithromycin Erm MIC90, >8 microg/ml; telithromycin Mef MIC90, 1.0 microg/ml). Both compounds lacked activity against constitutive macrolide-resistant Staphylococcus aureus but had good activities against inducibly resistant Staphylococcus aureus (ABT-773 MIC90, 0.06 microg/ml; telithromycin MIC90, 0.5 microg/ml). ABT-773 has superior activity against macrolide-resistant streptococci compared to that of telithromycin.
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Cao Z, Tongate C, Elin RJ. Evaluation of AVL988/4 analyzer for measurement of ionized magnesium and ionized calcium. Scand J Clin Lab Invest 2002; 61:389-94. [PMID: 11569486 DOI: 10.1080/003655101316911431] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Ionized magnesium (Mg++) and ionized calcium (Ca++) are the physiologically active forms of these elements in the body and their concentrations have clinical value. Though the AVL988/4 instrument that measures concentrations of Mg++ and Ca++ has been evaluated, some clinically important parameters were unknown. In this study, we evaluated AVL988/4 analyzer for measuring Mg++ and Ca++ concentrations and provided the following information: (1) The newly formulated Becton Dickinson (BD) Vacutainer plastic tubes with clot activator and silicone as the stopper lubricant (serial no. 367820) caused a significant high bias for the Mg++ measurement but had no effect on the Ca++ measurement; (2) the optimal conditions for specimen storage were no exposure to air at 4 degrees C for up to 24 h; (3) no significant difference in the results of the Ca++ concentration determined using AVL988/4 or i-STAT; (4) no carryover between samples was found.
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McLennan SV, Kelly DJ, Cox AJ, Cao Z, Lyons JG, Yue DK, Gilbert RE. Decreased matrix degradation in diabetic nephropathy: effects of ACE inhibition on the expression and activities of matrix metalloproteinases. Diabetologia 2002; 45:268-75. [PMID: 11935159 DOI: 10.1007/s00125-001-0730-4] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS Extracellular matrix accumulation is thought to be involved in the pathogenesis of diabetic nephropathy. Increased matrix synthesis has been well documented but the effects of diabetes on degradative pathways, particularly in the in vivo setting, have not been fully explored. Furthermore, the effect of renoprotective therapies on matrix accumulation through these pathways has not been examined. We investigated the degradative pathway of type IV collagen and the effects of ACE inhibition in experimental diabetic nephropathy. METHODS Diabetes was induced in 16 rats by administrating streptozocin; 8 of the diabetic rats were allocated at random to receive the ACE inhibitor perindopril (2 mg/l) in their drinking water and 8 age and weight matched rats served as controls. Gene expression of matrix metalloproteinase ( MMP) and tissue inhibitor of metalloproteinase ( TIMP) was measured by RT-PCR and type IV collagen content by immunohistochemistry. MMP activities were determined by degradation of a radiolabelled substrate and by zymography. RESULTS Six months of diabetes was associated with a decrease in mRNA and enzymatic activity of MMP-9 (21 % and 51 % respectively, p < 0.05 vs control) and a 51 % increase in TIMP-1 mRNA ( p < 0.05 vs control). By contrast, MMP-2 mRNA was increased but its activity decreased (43 % and 43 % respectively, p < 0.05 vs control). Total degradative capacity of kidney tissue from diabetic rats was also lower (Control: 48 +/- 7 %, Diabetic: 33 +/- 6 %, p < 0.05). Activation of latent MMPs with amino-phenylmercuric acetate increased matrix degradation by two-fold. However the relative decrease associated with experimental diabetes still remained. All diabetes-associated changes in MMP and TIMP mRNA and activities were attenuated by perindopril treatment in association with reduced type IV collagen accumulation. CONCLUSIONS/INTERPRETATION These results indicate that the impairment of matrix degradation contributes to matrix accumulation in diabetic nephropathy and that the beneficial effects of ACE inhibition could in part be mediated by modulation of changes in matrix degradative pathways.
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Bonnet F, Cao Z, Cooper ME. Apoptosis and angiotensin II: yet another renal regulatory system? EXPERIMENTAL NEPHROLOGY 2002; 9:295-300. [PMID: 11549846 DOI: 10.1159/000052624] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Apoptosis plays a key role in the regulation of normal renal structure and kidney remodeling in various renal diseases. Angiotensin II plays a prominent role in renal injury through its receptor subtypes, the type 1 (AT1) receptor and the type 2 (AT2) receptor, which involve different molecular mechanisms. In addition to its haemodynamic actions, angiotensin II induces apoptosis. Angiotensin II also increases proliferation in the kidney. A close correlation between renal cell proliferation and apoptosis has been shown in renal diseases as well as in the angiotensin II infusion model. Angiotensin induces upregulation of p53 and other pro-apoptotic proteins. Recent studies suggest that both AT1 and AT2 receptors influence the apoptotic process in the kidney. These apoptotic effects of angiotensin II should be considered as representing another regulatory mechanism that may modulate the balance between cell growth and proliferation within the kidney.
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Rej R, Norton-Wenzel CS, Cao Z. Target values and method evaluation in proficiency testing programs. Clin Chem 2001; 47:2185-6. [PMID: 11719494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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215
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Fang X, Cao Z, Beck T, Tan W. Molecular aptamer for real-time oncoprotein platelet-derived growth factor monitoring by fluorescence anisotropy. Anal Chem 2001; 73:5752-7. [PMID: 11774917 DOI: 10.1021/ac010703e] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Monitoring proteins in real time and in homogeneous solution has always been a difficult task. We have applied a fluorophore-labeled molecular probe based on a high-affinity platelet-derived growth factor (PDGF) aptamer for the ultrasensitive detection of PDGF in homogeneous solutions. The aptamer is labeled with fluorescein to specifically bind with the PDGF protein. Fluorescence anisotropy is used for the real-time monitoring of the binding between the aptamer and the protein. When the labeled aptamer is bound with its target protein, the rotational motion of the fluorophore attached to the complex becomes much slower because of an increased molecular weight after binding, resulting in a significant fluorescence anisotropy change. Using the anisotropy change, we are able to detect the binding events between the aptamer and the protein in real time and in homogeneous solutions (detection without separation). This assay is highly selective and ultrasensitive. It can detect PDGF in the subnanomolar range. The new method for protein detection is simple and inherits all of the advantages of molecular aptamers. Efficient oncoprotein detection using aptamer-based fluorescence anisotropy measurement will find wide applications in protein monitoring, in cancer diagnosis as well as other studies in which protein analysis is important.
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Ma Z, Clark RF, Brazzale A, Wang S, Rupp MJ, Li L, Griesgraber G, Zhang S, Yong H, Phan LT, Nemoto PA, Chu DT, Plattner JJ, Zhang X, Zhong P, Cao Z, Nilius AM, Shortridge VD, Flamm R, Mitten M, Meulbroek J, Ewing P, Alder J, Or YS. Novel erythromycin derivatives with aryl groups tethered to the C-6 position are potent protein synthesis inhibitors and active against multidrug-resistant respiratory pathogens. J Med Chem 2001; 44:4137-56. [PMID: 11708916 DOI: 10.1021/jm0102349] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel series of erythromycin derivatives has been discovered with potent activity against key respiratory pathogens, including those resistant to erythromycin. These compounds are characterized by having an aryl group tethered to the C-6 position of the erythronolide skeleton. Extensive structural modification of the C-6 moiety led to the discovery of several promising compounds with potent activity against both mef- and erm-mediated resistant Streptoccoccus pneumoniae. Preliminary mechanistic studies indicated that the new macrolides are potent protein synthesis inhibitors, which interact with methylated ribosomes isolated from resistant organisms. In experimental animal models, these compounds exhibited excellent in vivo efficacy and balanced pharmacokinetic profiles.
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Jiao P, Huang Y, Li S, Hua Y, Cao Z. Effects and mechanisms of H(2)O(2) on production of dicarboxylic acid. Biotechnol Bioeng 2001; 75:456-62. [PMID: 11668445 DOI: 10.1002/bit.10027] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The system of producing long chain dicarboxylic acid (DCA) by Candida tropicalis is an aerobic and viscous fermentation system. A method to overcome the gas-liquid transport resistance and to increase oxygen supply is by adding hydrogen peroxide (H(2)O(2)) to the fermentation system. Here we report that the H(2)O(2) not only can enhance the oxygen supply but also change the metabolism by inducing cytochrome P450, the key enzyme of a, o-oxidation. When C. tropicalis was cultivated in a 3-L bioreactor using the combination of aeration and H(2)O(2) feeding, DCA production rates increased by about 10% after a short period of decrease at the beginning. Furthermore, the experiments showed that the maximum activities of P450 could be induced at 2 mM H(2)O(2), and the inducible mechanisms are also discussed. Moreover, we suggest that alkane might be oxidized through the "peroxide shunt pathway" when H(2)O(2) is present. By adding H(2)O(2), the DCA yield in a 22-L bioreactor could increase by 25.3% and reach 153.9 g/L.
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Zhu S, Li W, Cao Z. A naturally occurring non-coding fusion transcript derived from scorpion venom gland: implication for the regulation of scorpion toxin gene expression. FEBS Lett 2001; 508:241-4. [PMID: 11718723 DOI: 10.1016/s0014-5793(01)03067-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Scorpion venom glands synthesize and secrete a great number of low molecular mass toxic peptides for prey and defense. Many cDNAs and genomic genes encoding these toxins have been isolated and sequenced. However, their expression regulation mechanism is not yet known at present. During screening of a cDNA library prepared from venom glands of the scorpion Buthus martensii Karsch, we isolated a natural fusion cDNA composed of the 5'-untranslated region (UTR) and upstream coding sequence of a long-chain toxin transcript and the downstream coding sequence and 3'-UTR of a short-chain toxin transcript. The junction site is just the overlapping region of 11 nucleotides (GGCAAGGAAAT) between the two wild transcripts, and thus leads to the formation of an early stop codon, which will cause premature translation. Based on the above observations, combined with the genomic data, we proposed a characteristic regulation mechanism of scorpion toxin genes, in which trans-splicing and nonsense mediated mRNA decay are involved.
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Miller KA, Eklund EA, Peddinghaus ML, Cao Z, Fernandes N, Turk PW, Thimmapaya B, Weitzman SA. Kruppel-like factor 4 regulates laminin alpha 3A expression in mammary epithelial cells. J Biol Chem 2001; 276:42863-8. [PMID: 11551969 DOI: 10.1074/jbc.m108130200] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Laminin-5, the major extracellular matrix protein produced by mammary epithelial cells, is composed of three chains (designated alpha3A, beta3, and gamma2), each encoded by a separate gene. Laminin-5 is markedly down-regulated in breast cancer cells. Little is known about the regulation of laminin gene transcription in normal breast cells, nor about the mechanism underlying the down-regulation seen in cancer. In the present study, we cloned the promoter of the gene for the human laminin alpha3A chain (LAMA3A) and investigated its regulation in functionally normal MCF10A breast epithelial cells and several breast cancer cell lines. Using site-directed mutagenesis of promoter-reporter constructs in transient transfection assays in MCF10A cells, we find that two binding sites for Kruppel-like factor 4 (KLF4/GKLF/EZF) are required for expression driven by the LAMA3A promoter. Electrophoretic mobility shift assays reveal absence of KLF4 binding activity in extracts from T47D, MDA-MB 231, ZR75-1, MDA-MB 436, and MCF7 breast cancer cells. Transient transfection of a plasmid expressing KLF4 activates transcription from the LAMA3A promoter in breast cancer cells. A reporter vector containing duplicate KLF4-binding sites in its promoter is expressed at high levels in MCF10A cells but at negligible levels in breast cancer cells. Thus, KLF4 is required for LAMA3A expression and absence of laminin alpha3A in breast cancer cells appears, at least in part, attributable to the lack of KLF4 activity.
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Abstract
The renin angiotensin system (RAS) has been implicated in tubulointerstitial injury in a range of clinical and experimental settings. Angiotensin II, the major effector molecule of the RAS, in addition to its effects on systemic blood pressure and intrarenal hemodynamics, also acts as a local hormone and growth factor to modulate renal function and pathology. There is increasing evidence for a pivotal role of this hormone in influencing renal tubular and interstitial function and structure including regulation of multiple cytokines and chemokines, promoting infiltration of monocytes/macrophages, promoting cellular proliferation, and inducing apoptosis. Pathologic actions of angiotensin II lead to tubulointerstitial fibrosis and inflammation via a range of cytokines and chemokines including transforming growth factor (TNF)-beta1, osteopontin, tumor necrosis factor (TNF)-alpha, secreted protein acidic and rich in cysteine (SPARC), and RANTES (regulated on activation normal T-cell expression and secreted). Blockade of production of angiotensin II by an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II receptor antagonism with an angiotensin type 1 receptor antagonist has been shown to attenuate tubulointerstitial injury and reduce expression of cytokines and matrix proteins. The role of angiotensin II in tubulointerstitial fibrosis and inflammation is addressed in this article.
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221
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Cao Z, Wanagat J, McKiernan SH, Aiken JM. Mitochondrial DNA deletion mutations are concomitant with ragged red regions of individual, aged muscle fibers: analysis by laser-capture microdissection. Nucleic Acids Res 2001; 29:4502-8. [PMID: 11691938 PMCID: PMC60181 DOI: 10.1093/nar/29.21.4502] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Laser-capture microdissection was coupled with PCR to define the mitochondrial genotype of aged muscle fibers exhibiting mitochondrial enzymatic abnormalities. These electron transport system (ETS) abnormalities accumulate with age, are localized segmentally along muscle fibers, are associated with fiber atrophy and may contribute to age-related fiber loss. DNA extracted from single, 10 microm thick, ETS abnormal muscle fibers, as well as sections from normal fibers, served as templates for PCR-based deletion analysis. Large mitochondrial (mt) DNA deletion mutations (4.4-9.7 kb) were detected in all 29 ETS abnormal fibers analyzed. Deleted mtDNA genomes were detected only in the regions of the fibers with ETS abnormalities; adjacent phenotypically normal portions of the same fiber contained wild-type mtDNA. In addition, identical mtDNA deletion mutations were found within different sections of the same abnormal region. These findings demonstrate that large deletion mutations are associated with ETS abnormalities in aged rat muscle and that, within a fiber, deletion mutations are clonal. The displacement of wild-type mtDNAs with mutant mtDNAs results in concomitant mitochondrial enzymatic abnormalities, fiber atrophy and fiber breakage.
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MESH Headings
- Aging/physiology
- Animals
- Cellular Senescence
- DNA Mutational Analysis
- DNA, Mitochondrial/genetics
- Dissection/methods
- Electron Transport
- Genome
- Genotype
- Lasers
- Male
- Mitochondria, Muscle/enzymology
- Mitochondria, Muscle/genetics
- Mitochondria, Muscle/metabolism
- Mitochondria, Muscle/pathology
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Phenotype
- Polymerase Chain Reaction
- Rats
- Rats, Inbred BN
- Rats, Inbred F344
- Sequence Deletion/genetics
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222
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He H, Ding Y, Cao Z, Shao Y, Bartlam M, Tang H, Jiang F, Liu Y, Liu J, Zhao N, Rao Z. Crystallization and preliminary X-ray crystallographic analysis of native and selenomethionyl recombinant tabtoxin-resistance protein complexed with acetyl-coenzyme A. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2001; 57:1729-31. [PMID: 11679759 DOI: 10.1107/s0907444901014202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2001] [Accepted: 08/29/2001] [Indexed: 11/10/2022]
Abstract
Tabtoxin-resistance protein (TTR), an acetyltransferase from Pseudomonas syringae pv. tabaci, was overexpressed in Eschericha coli M15 and the TTR fusion protein complexed with acetyl-coenzyme A (AcCoA) was purified and crystallized. Diffraction data were collected to 3.0 A resolution in-house and the crystal was found to belong to space group P2(1), with unit-cell parameters a = 47.6, b = 66.6, c = 53.5 A, beta = 104.3 degrees. Furthermore, a selenomethionine (SeMet) TTR fusion protein derivative was overexpressed in the same expression system and its complex with AcCoA was purified in a reductive environment. The SeMet TTR derivative crystallized in two forms: the first was identical to that observed for native crystals and the second belonged to space group C2, with unit-cell parameters a = 101.7, b = 45.6, c = 84.2 A, beta = 105.8 degrees. Data from the P2(1) crystal form were collected in-house to 2.3 A resolution. Subsequently, three different wavelength data sets of the C2 crystal form to 1.55 A resolution were collected at the Advanced Photon Source at Argonne National Laboratory.
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223
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Cao Z, Liu Q, Jiang Y, Shen Q, Dou X, Ozaki Y. Phase shift at a turning point in a planar optical waveguide. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2001; 18:2161-2163. [PMID: 11551049 DOI: 10.1364/josaa.18.002161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present a novel matrix approach to proving that the phase shift at a turning point in a planar optical wave-guide is exactly equal to pi rather than to pi/2 or to some other value. We also show the existence of phase contributions from reflected subwaves, which to our knowledge have never been taken into account previously.
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224
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Wang Y, Cao Z. [The progress of electrogastrogram]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2001; 18:491-3. [PMID: 11605524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
This paper reviews the advances in basic researches on the physiological factors and other factors that influence electrogastrogram and summarizes the clinical application of electrogastrogram in the diagnoses and studies of gastric dyspepsia, gastroparesis, delayed gastric emptying, kinetia and gastrohelcosis.
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225
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Cheng G, Cao Z, Xu X, van Meir EG, Lambeth JD. Homologs of gp91phox: cloning and tissue expression of Nox3, Nox4, and Nox5. Gene 2001; 269:131-40. [PMID: 11376945 DOI: 10.1016/s0378-1119(01)00449-8] [Citation(s) in RCA: 627] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
gp91phox is the catalytic subunit of the respiratory burst oxidase, an NADPH-dependent, superoxide generating enzyme present in phagocytes. In phagocytes, the enzyme functions in host defense, but reactive oxygen generation has also been described in a variety of non-phagocytic cells, including cancer cells. We previously reported the cloning of Nox1 (NADPH oxidase1), a homolog of gp91phox, its expression in colon and vascular smooth muscle, and its oncogenic properties when overexpressed [Suh et al. (1999). Nature 401, 79-82]. Herein, we report the cloning and tissue expression of three additional homologs of gp91phox, termed Nox3, Nox4 and Nox5, members of a growing family of gp91phox homologs. All are predicted to encode proteins of around 65 kDa, and like gp91phox, all show 5-6 conserved predicted transmembrane alpha-helices containing putative heme binding regions as well as a flavoprotein homology domain containing predicted binding sites for both FAD and NADPH. Nox3 is expressed primarily in fetal tissues, and Nox4 is expressed in not only fetal tissues, but also kidney, placenta and glioblastoma cells. Nox5 is expressed in a variety of fetal tissues as well as in adult spleen and uterus. Nox isoforms are aberrantly expressed in several cells derived from human cancers, with Nox4 being the isoform most frequently expressed in the tumor cells investigated. Thus, expression of Nox family members is likely to account for some of the reactive oxygen generation seen in non-phagocytic cells.
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