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Fu X, Tao L, Zhang X. An HSV-2-based oncolytic virus deleted in the PK domain of the ICP10 gene is a potent inducer of apoptotic death in tumor cells. Gene Ther 2007; 14:1218-25. [PMID: 17538637 DOI: 10.1038/sj.gt.3302971] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The N-terminus of the ICP10 gene of type 2 herpes simplex virus (HSV-2) encodes a serine/threonine protein kinase (PK) domain that facilitates HSV-2 replication by activating the Ras/MEK/MAPK mitogenic pathway and suppressing apoptosis. We recently demonstrated that deletion of this oncogenic PK domain converts it to a potent oncolytic agent. This mutant, which we have designated FusOn-H2, preferentially replicates in and thus lyses tumor cells in which the Ras signaling pathway is constitutively activated. Here we show that FusOn-H2 exerts strong ability in inducing apoptosis in different lines of human tumor cells and in esophageal tumors growing in mice. The apoptotic effect produced by FusOn-H2 was not restricted to infected cells but extended to uninfected bystander cells, thereby increasing the lethality of the virus. These results add a novel killing mechanism to those previously assigned to FusOn-H2, rendering it an attractive candidate for clinical trials.
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Cao Y, Jiao X, Yuan Y, Tao L, Lopez B, Christopher T, Ma X. Endothelial Dysfunction in Adiponectin Knockout Mice and its Mechanisms Involved. Acad Emerg Med 2007. [DOI: 10.1197/j.aem.2007.03.1203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Fu X, Tao L, Zhang X. An oncolytic virus derived from type 2 herpes simplex virus has potent therapeutic effect against metastatic ovarian cancer. Cancer Gene Ther 2007; 14:480-7. [PMID: 17290283 DOI: 10.1038/sj.cgt.7701033] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oncolytic viruses derived from herpes simplex virus (HSV) have shown considerable promise as antitumor agents against solid tumors including ovarian cancer. The current group of oncolytic HSVs was constructed exclusively from type 1 HSV. To exploit further the therapeutic potential of replication-selective viruses, we constructed an oncolytic virus from type 2 HSV by deleting the protein kinase domain of the viral ICP10 gene, which targets the activated Ras signaling pathway in tumor cells. In the study reported here, we administered this HSV-2-derived virus intraperitoneally (i.p.) to nude mice bearing metastatic human ovarian tumor xenografts, evaluated its oncolytic activity, and compared with to that of a virus constructed from HSV-1. Two injections of the HSV-2-derived virus (3 x 10(6) pfu per dose) led to complete eradication of disseminated tumors in the peritoneal cavity in more than 87% of the mice, whereas the HSV-1-based oncolytic virus, administered at the same dose and on the same schedule, eradicated tumor nodules in only 12% of mice (P<0.01). We conclude that i.p. administration of this HSV-2-based oncolytic virus may provide effective treatment for metastatic human ovarian cancer.
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Wei C, Xingcan Z, Tao L. Considerations on the issue of water reuse in eastern China plain brooky regions. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2007; 55:387-95. [PMID: 17305163 DOI: 10.2166/wst.2007.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This paper summarises the characteristics of water systems in plain brooky regions of Jiangsu Province in eastern China, and discusses the water shortage issue resulting from water quality deterioration. It is emphasised that attention should be paid not only to the full treatment of wastewater and rainwater but also the proper disposal of treated wastewater which meets the national discharge standard GB18918-2002 but still contain significant amount of pollutants if compared with the national surface water quality standard GB3838-2002. To the plain brooky regions of Jiangsu Province, the discharged pollutant loads still significantly exceed the environmental capacity of the receiving waters even if all treated wastewater meet the first grade B limits of GB18918-2002, and the water pollution problem still cannot be really eliminated. Therefore, the disposal and utilisation of the treated wastewater need to be taken into consideration. Thus, this paper presents some considerations on the disposal of treated wastewater and management of urban rainwater, mainly concerning water reclamation and reuse, construction of ecological purification systems, strategy changes of wastewater and rainwater management, and the key technology selections.
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Tao L, Chen X, Qin Z, Bian S. Could NF-κB and caspase-3 be markers for estimation of post-interval of human traumatic brain injury? Forensic Sci Int 2006; 162:174-7. [PMID: 16854541 DOI: 10.1016/j.forsciint.2006.06.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Previous studies in a rat model showed expressions of caspase-3 (p20) and NF-kappaB (p65) in different time after TBI. We test the activation changes of caspase-3 and NF-kappaB of human specimen after traumatic brain injury (TBI) in this study to see whether they could be markers to estimate post-intervals of TBI for forensic practice. MATERIAL AND METHODS Caspase-3 (p20) and NF-kappaB (p65) immunohistochemical staining were performed on 39 TBI specimens (dead from TBI) and eight controls (dead from none TBI reasons) grouped 0, 12, 24, 48, 72, 168, 264 and 480 h. Positive cells were counted and image analysis techniques were used to determine the morphological changes in each group. RESULTS Immunohistochemical analysis showed a marked induction of caspase-3 (p20) in every injured group compared with normal controls; each positive group has it's morphological character with variant positive cell count. NF-kappaB (p65) did not showed markedly change compared with normal controls until 168 h after TBI and almost all nerve cells were stained by NF-kappaB (p65) in 264 and 480 h groups. CONCLUSION NF-kappaB (p65) could contribute to estimate delayed death cases after TBI for forensic applications. Caspase-3 (p20) estimating post-TBI intervals are dubious but could suggest TBI exists.
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Tao L, Lefèvre M, Ricci S, Saintigny P, Callard P, Périé S, Lacave R, Bernaudin JF, Lacau St Guily J. Detection of occult carcinomatous diffusion in lymph nodes from head and neck squamous cell carcinoma using real-time RT-PCR detection of cytokeratin 19 mRNA. Br J Cancer 2006; 94:1164-9. [PMID: 16622440 PMCID: PMC2361256 DOI: 10.1038/sj.bjc.6603073] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The aim of the present study was to evaluate the occult lymph node carcinomatous diffusion in head and neck squamous cell carcinoma (HNSCC). A total of 1328 lymph nodes from 31 patients treated between 2004 and 2005 were prospectively evaluated by routine haematoxylin–eosin–safran (HES) staining, immunohistochemistry (IHC) and real-time Taqman reverse–transcriptase polymerase chain reaction (real-time RT–PCR) assay. Amplification of cytokeratin 19 (CK19) mRNA transcripts using real-time RT–PCR was used to quantify cervical micrometastatic burden. The cervical lymph node metastatic rates determined by routine HES staining and real-time RT–PCR assay were 16.3 and 36.0%, respectively (P<0.0001). A potential change in the nodal status was observed in 13 (42.0%) of the 31 patients and an atypical pattern of lymphatic spread was identified in four patients (12.9%). Moreover, CK19 mRNA expression values in histologically positive lymph nodes were significantly higher than those observed in histologically negative lymph nodes (P<0.0001). These results indicate that real-time RT–PCR assay for the detection of CK19 mRNA is a sensitive and reliable method for the detection of carcinomatous cells in lymph nodes. This type of method could be used to reassess lymph node status according to occult lymphatic spread in patients with HNSCC.
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Qun L, Jie L, Tao L, Zhong Z, Zhen T. P-425. Fertil Steril 2006. [DOI: 10.1016/j.fertnstert.2006.07.785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Tao L, Gao E, Hu A, Coletti C, Wang Y, Christopher TA, Lopez BL, Koch W, Ma XL. Thioredoxin reduces post-ischemic myocardial apoptosis by reducing oxidative/nitrative stress. Br J Pharmacol 2006; 149:311-8. [PMID: 16921396 PMCID: PMC2014279 DOI: 10.1038/sj.bjp.0706853] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE Thioredoxin (Trx) is an oxidoreductase that prevents free radical-induced cell death in cultured cells. Here we assessed the mechanism(s) underlying the cardioprotective effects of Trx in vivo. EXPERIMENTAL APPROACH The effects of myocardial ischemia (30 min) and reperfusion were measured in mice, with assays of myocardial apoptosis, superoxide production, NOx and nitrotyrosine content, and myocardial infarct size. Recombinant human Trx (rhTrx, 0.7-20 mg kg(-1), i.p.) was given 10 min before reperfusion. KEY RESULTS Treatment with 2 mg kg(-1) rhTrx significantly decreased myocardial apoptosis and reduced infarct size (P<0.01). Nitrotyrosine content of cardiomyocytes was markedly reduced in rhTrx-treated animals (P<0.01). To further identify the mechanisms by which rhTrx may exert its anti-nitrative effect, iNOS expression and production of NOx and superoxide were determined. Treatment with rhTrx had no significant effect on iNOS expression or NOx content in the ischemic/reperfused heart. However, it markedly upregulated mSOD and reduced tissue superoxide content. To further establish a causative link between the anti- peroxynitrite effect and the cardioprotective effect of rhTrx, cultured adult cardiomyocytes were incubated with SIN-1, a peroxynitrite donor, (50 microM for 3 h) resulting in a nitrotyrosine content comparable to that seen in the ischemic/reperfused heart and causing significant cardiomyocyte apoptosis (P<0.01). Treatment with rhTrx markedly decreased SIN-1 induced apoptosis (P<0.01). CONCLUSIONS AND IMPLICATIONS These results demonstrate that Trx is a novel anti-apoptotic and cardioprotective molecule that exerts its cardioprotective effects by reducing ischemia/reperfusion-induced oxidative/nitrative stress.
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Tao L. Thioredoxin Nitration and Postischemic Myocardial Apoptosis: Role of ASK-1 Signaling. Acad Emerg Med 2006. [DOI: 10.1197/j.aem.2006.03.384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Atlagic D, Kiliç AO, Tao L. Unmarked gene deletion mutagenesis of gtfB and gtfC in Streptococcus mutans using a targeted hit-and-run strategy with a thermosensitive plasmid. ACTA ACUST UNITED AC 2006; 21:132-5. [PMID: 16476024 DOI: 10.1111/j.1399-302x.2006.00267.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Unmarked gene deletion of the Streptococcus mutans gtfB-gtfC locus was achieved using a thermosensitive plasmid. DNA fragments flanking the locus were amplified by polymerase chain reaction and jointly ligated into pG+host5, which was transformed into S. mutans at 37 degrees C to facilitate integration. A transformant was then grown at 28 degrees C for 60 generations without antibiotics to facilitate excision. Antibiotic sensitive clones appeared at a frequency of about 99% and were analyzed for deletions of gtfB, gtfC and a part of mbrA by the lack of insoluble glucan synthesis, sensitivity to bacitracin, and polymerase chain reaction. Targeted gene deletions occurred at a frequency of 2.5%.
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Li DY, Tao L, Liu H, Christopher TA, Lopez BL, Ma XL. Role of ERK1/2 in the anti-apoptotic and cardioprotective effects of nitric oxide after myocardial ischemia and reperfusion. Apoptosis 2006; 11:923-30. [PMID: 16547595 DOI: 10.1007/s10495-006-6305-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Experimental results from cultured cells suggest that there is cross-talk between nitric oxide (NO) and extracellular signal-regulated kinase (ERK) in their anti-apoptotic effect. However, the cross-talk between these two molecules in either direction has not been confirmed in the whole organ or whole animal level. The aim of the present study was to determine whether ERK may play a role in the anti-apoptotic and cardioprotective effects of NO in myocardial ischemia/reperfusion (MI/R). METHODS Isolated perfused mouse hearts were subjected to 20 min of global ischemia and 120 min of reperfusion and treated with vehicle or an NO donor (SNAP, 10 muM) during reperfusion. To determine the role of ERK1/2 in the anti-apoptotic and cardioprotective effects of NO, hearts were pre-treated (10 min before ischemia) with U0126, a selective MEK1/2 inhibitor (1 muM). RESULTS Treatment with SNAP exerted significant cardioprotective effects as evidenced by reduced cardiac apoptosis (TUNEL and caspase 3 activity, p < 0.01), and improved cardiac functional recovery (p < 0.01). In addition, treatment with SNAP resulted in a 2.5-fold increase in ERK activation when compared with heart receiving vehicle. Pre-treatment with U0126 slightly increased post-ischemic myocardial apoptosis but had no significant effect on cardiac functional recovery in this isolated perfused heart model. However, treatment with U0126 completely blocked SNAP-induced ERK activation and markedly, although not completely, inhibited the cardioprotection exerted by SNAP. CONCLUSION These results demonstrate that nitric oxide exerts its anti-apoptotic and cardioprotective effects, at least in part, by activation of ERK in ischemic/reperfused heart.
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Tao A, Tao L, Nicholson C. Cell cavities increase tortuosity in brain extracellular space. J Theor Biol 2005; 234:525-36. [PMID: 15808873 DOI: 10.1016/j.jtbi.2004.12.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Revised: 12/07/2004] [Accepted: 12/08/2004] [Indexed: 11/18/2022]
Abstract
Brain extracellular space (ECS) forms hindered pathways for molecular diffusion in chemical signaling and drug delivery. Hindrance is quantified by the tortuosity lambda; the tortuosity obtained from simulations using uniformly spaced convex cells is significantly lower than that measured experimentally. To attempt to account for the difference in results, this study employed a variety of ECS models based on an array of cubic cells containing open rectangular cavities that provided the ECS with dead-space microdomains. Monte Carlo simulations demonstrated that, in such ECS models, lambda can equal or exceed the typical experimental value of about 1.6. The simulations further revealed that lambda is relatively independent of cavity shape and the number of cavities per cell. It mainly depends on the total ECS volume fraction alpha, the cavity volume fraction alpha(c), and whether the cavity is located at the center of a cell face or formed at the junction of multiple cells. To describe the results from the different ECS models, an expression was obtained that related lambda to alpha, alpha(c), and an empirical exit factor beta that correlated with the ease with which a molecule could leave a cavity and its vicinity.
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Surgent R, Saw C, Tao L, Komanduri K. SU-FF-T-214: Quality Assurance Of Modern Helical CT-Simulator Scanners: Reproducibility Of Tissue Heterogeneity Curve. Med Phys 2005. [DOI: 10.1118/1.1997942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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214
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Saw C, Surgent R, Tao L, Komanduri K. SU-FF-T-230: Anomaly Characteristics Of Tissue Heterogeneity Curve From Three Commercially Available Tissue Characterization CT Phantoms. Med Phys 2005. [DOI: 10.1118/1.1997958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Gao F, Tao L, Yan W, Gao E, Liu HR, Lopez BL, Christopher TA, Ma XL. Early anti-apoptosis treatment reduces myocardial infarct size after a prolonged reperfusion. Apoptosis 2005; 9:553-9. [PMID: 15314283 DOI: 10.1023/b:appt.0000038035.75845.ab] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Significant myocardial apoptosis occurs in ischemia/reperfused hearts. However, the contribution of apoptosis to the development of myocardial injury remains controversial. The present study attempted to obtain evidence that inhibition of apoptosis at early reperfusion can reduce myocardial infarction after prolonged reperfusion. METHODS Adult male rats were subjected to 30 min ischemia and 4 (apoptosis assay) or 24 h (myocardial infarction determination) of reperfusion and treated with vehicle, SB 239063, insulin or insulin plus wortmannin. RESULTS Treatment with SB 239063 or insulin markedly decreased myocardial apoptosis (10.6 +/- 1.5% and 7.9 +/- 0.9% respectively, P < 0.01 vs. vehicle) and significantly reduced infarct size (43 +/- 3.6% and 35 +/- 2.9%, respectively, P < 0.01 vs. vehicle). Most interestingly, inhibition of insulin signaling with wortmannin to block insulin signaling not only blocked insulin's anti-apoptotic effect, but also abolished its infarct reduction property. CONCLUSION These data indicate that apoptosis contributes to the development of myocardial infarction, and inhibition of apoptosis at early reperfusion reduces the myocardial infarction.
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Tao L, Cheng Q. Novel beta-carotene ketolases from non-photosynthetic bacteria for canthaxanthin synthesis. Mol Genet Genomics 2004; 272:530-7. [PMID: 15538629 DOI: 10.1007/s00438-004-1083-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2004] [Accepted: 10/15/2004] [Indexed: 10/26/2022]
Abstract
We reported previously that the Rhodococcus erythropolis strain AN12 synthesizes the monocyclic carotenoids 4-keto gamma-carotene and gamma-carotene. We also identified a novel lycopene beta-monocyclase in this strain. Here we report the identification of the rest of the carotenoid synthesis genes in AN12. Two of these showed apparent homology to putative phytoene dehydrogenases. Analysis of Rhodococcus knockout mutants suggested that one of them ( crtI) encodes a phytoene dehydrogenase, whereas the other ( crtO) encodes a beta-carotene ketolase. Expression of the beta-carotene ketolase gene in an Escherichia coli strain which accumulates beta-carotene resulted in the production of canthaxanthin. In vitro assays using a crude extract of the E. coli strain expressing the crtO gene confirmed its ketolase activity. A crtO homologue (DR0093) from Deinococcus radiodurans R1 was also shown to encode a beta-carotene ketolase, despite its sequence homology to phytoene dehydrogenases. The Rhodococcus and Deinococcus CrtO ketolases both catalyze the symmetric addition of two keto groups to beta-carotene to produce canthaxanthin. Even though this activity is similar to the CrtW-type of ketolase activity, the CrtO ketolases show no significant sequence homology to CrtW-type ketolases. The presence of six conserved regions may be a signature for the CrtO-type of beta-carotene ketolases.
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Tao L, Nicholson C. Maximum geometrical hindrance to diffusion in brain extracellular space surrounding uniformly spaced convex cells. J Theor Biol 2004; 229:59-68. [PMID: 15178185 DOI: 10.1016/j.jtbi.2004.03.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Revised: 02/16/2004] [Accepted: 03/03/2004] [Indexed: 11/25/2022]
Abstract
Brain extracellular space (ECS) constitutes a porous medium in which diffusion is subject to hindrance, described by tortuosity, lambda = (D/D*)1/2, where D is the free diffusion coefficient and D* is the effective diffusion coefficient in brain. Experiments show that lambda is typically 1.6 in normal brain tissue although variations occur in specialized brain regions. In contrast, different theoretical models of cellular assemblies give ambiguous results: they either predict lambda-values similar to experimental data or indicate values of about 1.2. Here we constructed three different ECS geometries involving tens of thousands of cells and performed Monte Carlo simulation of 3-D diffusion. We conclude that the geometrical hindrance in the ECS surrounding uniformly spaced convex cells is independent of the cell shape and only depends on the volume fraction alpha (the ratio of the ECS volume to the whole tissue volume). This dependence can be described by the relation lambda = ((3-alpha)/2)1/2, indicating that the geometrical hindrance in such ECS cannot account for lambda > 1.225. Reasons for the discrepancy between the theoretical and experimental tortuosity values are discussed.
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Gadewar S, Tao L, Malone M, Doherty M. Process Alternatives for Coupling Reaction and Distillation. Chem Eng Res Des 2004. [DOI: 10.1205/026387604772992701] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tao L, Picataggio S, Rouvière PE, Cheng Q. Asymmetrically acting lycopene beta-cyclases (CrtLm) from non-photosynthetic bacteria. Mol Genet Genomics 2004; 271:180-8. [PMID: 14740205 DOI: 10.1007/s00438-003-0969-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2003] [Accepted: 11/21/2003] [Indexed: 10/26/2022]
Abstract
Carotenoids have important functions in photosynthesis, nutrition, and protection against oxidative damage. Some natural carotenoids are asymmetrical molecules that are difficult to produce chemically. Biological production of carotenoids using specific enzymes is a potential alternative to extraction from natural sources. Here we report the isolation of lycopene beta-cyclases that selectively cyclize only one end of lycopene or neurosporene. The crtLm genes encoding the asymmetrically acting lycopene beta-cyclases were isolated from non-photosynthetic bacteria that produced monocyclic carotenoids. Co-expression of these crtLm genes with the crtEIB genes from Pantoea stewartii (responsible for lycopene synthesis) resulted in the production of monocyclic gamma-carotene in Escherichia coli. The asymmetric cyclization activity of CrtLm could be inhibited by the lycopene beta-cyclase inhibitor 2-(4-chlorophenylthio)-triethylamine (CPTA). Phylogenetic analysis suggested that bacterial CrtL-type lycopene beta-cyclases might represent an evolutionary link between the common bacterial CrtY-type of lycopene beta-cyclases and plant lycopene beta- and epsilon-cyclases. These lycopene beta-cyclases may be used for efficient production of high-value asymmetrically cyclized carotenoids.
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Fu X, Meng F, Tao L, Jin A, Zhang X. A strict-late viral promoter is a strong tumor-specific promoter in the context of an oncolytic herpes simplex virus. Gene Ther 2003; 10:1458-64. [PMID: 12900760 DOI: 10.1038/sj.gt.3302029] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Confinement of transgene expression to target cells is highly desirable in gene therapy. Current strategies of transcriptional targeting to tumors usually rely on tissue-specific promoters to control gene expression. However, such promoters generally have much lower activity than the constitutive viral promoters. We have explored an alternative approach, using a strict-late viral promoter (UL38p) in the context of an oncolytic herpes simplex virus (HSV) for tumor-selective gene expression. As with many DNA viruses, the genomic transcription of HSV is a tightly regulated molecular cascade in which early and late phases of gene expression are separated by viral DNA replication. In particular, some of the late transcripts are categorized as strict-late, whose expression depends rigorously on the initiation of viral DNA replication. Our in vitro and in vivo characterization showed that in normal nondividing cells, where the oncolytic HSV has limited ability to replicate, the UL38p has minimal activity. However, in tumor or cycling cells where the virus can fully replicate, transgene expression from UL38p was almost as high as from the cytomegalovirus immediate-early promoter. These results suggest that delivery of therapeutic genes driven by UL38p through an oncolytic HSV may be an effective approach to gene therapy for malignant diseases.
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Kostichka K, Tao L, Bramucci M, Tomb JF, Nagarajan V, Cheng Q. A small cryptic plasmid from Rhodococcus erythropolis: characterization and utility for gene expression. Appl Microbiol Biotechnol 2003; 62:61-8. [PMID: 12835922 DOI: 10.1007/s00253-003-1242-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2002] [Revised: 11/25/2002] [Accepted: 01/03/2003] [Indexed: 11/30/2022]
Abstract
Exploration of metabolically diverse rhodococci is generally hampered by the lack of genetic tools. A small cryptic plasmid (pAN12) isolated from Rhodococcus erythropolis strain AN12 was sequenced. Plasmid pAN12 encodes proteins that share homology to replication proteins and putative cell division proteins. Based on in vitro transposon mutagenesis, we determined that the Rep protein of pAN12 is essential for plasmid replication in Rhodococcus spp., and the putative cell division protein Div is important for plasmid stability. The pAN12 replicon is able to replicate in R. erythropolis strains AN12 and CW23 (ATCC 47072) and is compatible with the nocardiophage Q4 replicon present on a Rhodococcus shuttle plasmid pDA71. pAN12 appears to belong to the pIJ101/pJV1 family of rolling circle replication plasmids. Expression of an isoprenoid pathway gene ( dxs) on the pAN12-derived multicopy shuttle vector increased production of carotenoid pigments in R. erythropolis ATCC 47072.
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Tao L. Rosiglitazone Improves Endothelial Function in Rabbits with Hypercholesterolemia by Reducing Oxidative Stress and Preserving NO/cGMP Signaling. Acad Emerg Med 2003. [DOI: 10.1197/aemj.10.5.425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ye JH, Tao L, Zhu L, Krnjević K, McArdle JJ. Decay of ethanol-induced suppression of glycine-activated current of ventral tegmental area neurons. Neuropharmacology 2002; 43:788-98. [PMID: 12367623 DOI: 10.1016/s0028-3908(02)00179-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We demonstrated previously that ethanol depresses glycine-induced currents in 45% of neurons freshly isolated from the ventral tegmental area (VTA) of rats (), and that protein kinase C (PKC) modulates this action of ethanol (). In the present study, we investigated the time course of this effect of ethanol on VTA neurons from young rats. For 70% of the neurons in which ethanol reduced glycine-evoked currents, this depressant effect gradually diminished during continuous superfusion with ethanol. Its action decayed faster when ethanol was applied in several brief pulses than by continuous superfusion. On the other hand, the decay was especially slower when ethanol was applied in pulses at longer intervals or by preincubation. Phorbol ester 12,13-dibutyrate (PDBu, 1 microM), an activator of PKC, also depressed glycine-induced currents. In approximately 40% (6/15) of the neurons, the effect of PDBu diminished with time and was antagonized by the specific PKC inhibitor, chelerythrine (7 microM). Chelerythrine also attenuated the ethanol-induced depression of glycine-induced currents and its time-dependent decay, thus confirming our previous evidence that PKC mediates, at least in part, the decay of the depressant effect of ethanol on glycine-induced currents of VTA neurons.
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Tao L, Xu H, Sun M, Ikeda T. [Investigation of the bone mineral density in hemodialysis patients for different terms]. HUNAN YI KE DA XUE XUE BAO = HUNAN YIKE DAXUE XUEBAO = BULLETIN OF HUNAN MEDICAL UNIVERSITY 2002; 24:177-8. [PMID: 11938784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The investigate the change of bone mineral density(BMD) in hemodialysis patients for different terms of hemodialysis, 50 patients were divided into three groups according to the duration of hemodialysis. Group I was < 5 years. Group II was 5-10 years, and Group III > 10 years. The BMD of the patients were assayed by using dual energy X-ray bone absorptiometer. Serum calcium, phosphorus, aluminium, and intact parathyroid hormone(iPTH) were detected at the same time. The mean BMD and serum iPTH were 0.624 +/- 0.180 g.cm-2 and 9.67 +/- 9.46 ng.cm-1 in Group I, 0.573 +/- 0.160 g.ml-2 and 10.16 +/- 28.05 ng.ml-1 in Group II, and 0.513 +/- 0.117 g.cm-2 and 10.75 +/- 24.94 ng.ml-1 in Group III, respectively. There was no statistical significance in BMD (P > 0.05) and iPTH(P > 0.05) among the above groups. The BMD of hemodialysis patients is not affected by different terms of hemodialysis.
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Abstract
Streptococcus mutans glucosyltransferases form extracellular glucans from sucrose to promote adhesion to the teeth. We tested whether additional factors are involved in S. mutans sucrose-dependent adhesion. By screening a pVA891-insertion mutant library of S. mutans LT11, we isolated four clones deficient in adhesion to glass in the presence of sucrose, but normal in glucosyltransferase activities. The genetic loci flanking the insertion sites were retrieved and identified. They encode glycerol-3-phosphate dehydrogenase, an ABC transporter, a multidrug-efflux pump, and either the ribulose monophosphate operon or ascorbate metabolism operon. The four mutants were analyzed for their phenotypic expression and in vivo colonization in rats. The multidrug efflux pump mutant failed to colonize the rats. Three other mutants colonized the rats by reverting to the wild type. Therefore, these four factors may contribute to S. mutans sucrose-dependent adhesion.
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