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Englert A, Ren S, Masliyah J, Xu Z. Interaction forces between a deformable air bubble and a spherical particle of tuneable hydrophobicity and surface charge in aqueous solutions. J Colloid Interface Sci 2012; 379:121-9. [DOI: 10.1016/j.jcis.2012.04.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 04/14/2012] [Accepted: 04/16/2012] [Indexed: 11/28/2022]
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102
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Ren S, Ren G. External beam radiation therapy is safe and effective in treating primary pulmonary amyloidosis. Respir Med 2012; 106:1063-9. [DOI: 10.1016/j.rmed.2012.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 01/04/2012] [Accepted: 02/20/2012] [Indexed: 11/16/2022]
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103
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Ren S, Li FH, Ma SL. Two new oxamidato-bridged CuII-CuII complexes: Synthesis, structure, spectra, and cyclic voltammetry studies. RUSS J COORD CHEM+ 2012. [DOI: 10.1134/s1070328412050089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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104
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Ma SL, Ren S. Novel bimetallic Cr3Yb3 mixed salt containing a 3d-4f heterometallic Cr2Yb3 cluster. RUSS J COORD CHEM+ 2012. [DOI: 10.1134/s1070328412040070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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105
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Ren S. Combined Churg-Strauss syndrome and allergic bronchopulmonary aspergillosis - case report and review of the literature. CLINICAL RESPIRATORY JOURNAL 2012; 7:e6-10. [PMID: 22325470 DOI: 10.1111/j.1752-699x.2012.00285.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A rare case of combined Churg-Strauss syndrome (CSS) and allergic bronchopulmonary aspergillosis (ABPA) was presented. A 41-year-old woman was diagnosed with CSS based upon asthma, eosinophilia (23%), chest radiographic findings, paranasal sinusitis, peripheral neuropathy and positive p- anti-neutrophil cytoplasmic antibodies (pANCA). The diagnosis of ABPA was established on the pathological findings of allegic mucin impaction and fungal hyphae on lung biopsy. It was further proved by positive serum IgE and IgG antibodies specific to afumigatus. The clinical investigation features were reviewed in the patients with combined CSS and ABPA. All patients had the time sequence of the development of CSS after ABPA uniformly, suggesting immunopathogenesis involving the emergence of CSS. The role of lung biopsy in the diagnosis of the condition was emphasized.
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Ren S, Ma SL. A novel hexaaza macrocyclic complex [CuL](ClO4)2. RUSS J COORD CHEM+ 2012. [DOI: 10.1134/s1070328412010101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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107
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Zhu Z, Zhou H, Yu X, Chen L, Zhang H, Ren S, Wu Y, Luo D. Potential regulatory role of calsequestrin in platelet Ca(2+) homeostasis and its association with platelet hyperactivity in diabetes mellitus. J Thromb Haemost 2012; 10:116-24. [PMID: 22060633 DOI: 10.1111/j.1538-7836.2011.04550.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Altered Ca(2+) homeostasis contributes significantly to platelet hyperactivity in diabetes mellitus. Calsequestrin (CSQ), as a Ca(2+) buffer protein in the sarcoplasmic reticulum, also regulates the Ca(2+) release process in muscles. We hypothesized that CSQ may be expressed in platelets, but is altered and involved in diabetic platelet Ca(2+) abnormalities and hyperaggregability. METHODS CSQ expression in platelets from streptozotocin-induced type 1 diabetes rats, type 2 diabetes volunteers and Goto-Kakizaki rats were analyzed by western blotting and RT-qPCR. Platelet Ca(2+) and aggregation were evaluated with Fura2 and an aggregometer, respectively. RESULTS Platelets from diabetic patients and rats exhibited increased resting Ca(2+) levels, and hyperactive Ca(2+) and aggregation responses to agonists. This enhanced basal Ca(2+) was largely dependent on intracellular Ca(2+) and insensitive to inositol 1,4,5-trisphosphate receptor (IP(3)R) antagonism. Additionally, the expression of the skeletal CSQ isotype (CSQ-1) was detected in both rat and human platelets, but its levels were significantly lowered in diabetic platelets as compared with normal platelets. Impairment of CSQ by trifluoperazine caused concentration-dependent Ca(2+) release in normal platelets and HEK293 cells. Knocking down CSQ-1 in HEK293 cells resulted in increased leakage of Ca(2+), which was also insensitive to IP(3)R inhibition, and exaggerated Ca(2+) release following carbachol treatment. CONCLUSIONS Downregulation of CSQ-1 in diabetic platelets and impairment of CSQ-1 in normal cells leads to disturbed Ca(2+) release, demonstrating a potential role for CSQ-1 in the regulation of the platelet Ca(2+) release process and a possible causal contribution to diabetic platelet hyperactivity.
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Tang MY, Ren S, Xu GF, Ma SL. A novel bimetallic chain based on [Mo(Cn)8]3− and Eu3+ ions as building blocks. RUSS J COORD CHEM+ 2011. [DOI: 10.1134/s1070328411090107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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109
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Brandis KJ, Kingsford RT, Ren S, Ramp D. Crisis water management and ibis breeding at Narran Lakes in arid Australia. ENVIRONMENTAL MANAGEMENT 2011; 48:489-498. [PMID: 21667315 DOI: 10.1007/s00267-011-9705-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Accepted: 05/29/2011] [Indexed: 05/30/2023]
Abstract
Narran Lakes is a Ramsar site recognised for its importance for colonial waterbird breeding, which only occurs after large highly variable flooding events. In 2008, 74,095 pairs of ibis bred for the first time in seven years, establishing two contiguous colonies, a month apart. Most (97%) of the colony consisted of the straw-necked ibis (Threskiornis spinicollis) with the remainder consisting of glossy ibis (2%, Plegadis falcinellus) and Australian white ibis (1%, T. molucca). Following cessation of river flows, water levels fell rapidly in the colony site, resulting in a crisis management decision by governments to purchase and deliver water (10,423 Ml) to avert mass desertion of the colonies. There were significant differences in the reproductive success of each colony. In colony 1 60% of eggs hatched and 94% of chicks fledged, while in colony 2 40% of eggs hatched with only 17% of chicks fledging. Statistical analyses found that water depth was a significant variable in determining reproductive success. Rapid falls in water level during the chick stage in colony 2 resulted in decreased chick and overall offspring success. The results of this study identify the impact of upstream water resource development on colonial waterbird breeding and have implications for water management policies.
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Zhou C, Wu YL, Chen G, Feng JF, Liu X, Wang C, Zhang S, Wang J, Zhou S, Ren S, Lu S, Zhang L. Updated efficacy and quality-of-life (QoL) analyses in OPTIMAL, a phase III, randomized, open-label study of first-line erlotinib versus gemcitabine/carboplatin in patients with EGFR-activating mutation-positive (EGFR Act Mut+) advanced non-small cell lung cancer (NSCLC). J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.7520] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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111
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Chen X, Zhou C, Sun H, Ren S, Zhang L, Zhou S. Association of XRCC3 and XPD751 SNP with response to platinum-based chemotherapy in advanced NSCLC patients. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e18045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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112
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Ren S, Zhou S, Zhang L., Chen X, Zhou C. Individualized chemotherapy in the advanced NSCLC patients based on the mRNA level of BRCA1 and RRM1. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e18029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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113
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Pearce J, Li M, Ren S, Li G, Chen W, Vincent C, Kirk K. CO2 storage capacity estimates for selected regions of China - results from the China-UK Near Zero Emissions Coal (NZEC) Initiative. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.egypro.2011.02.608] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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114
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Jia Y, Liu M, Cao L, Zhao X, Wu J, Lu F, Li Y, He Y, Ren S, Ju Y, Wang Y, Li Z. Recombinant human endostatin, Endostar, enhances the effects of chemo-radiotherapy in a mouse cervical cancer xenograft model. EUR J GYNAECOL ONCOL 2011; 32:316-324. [PMID: 21797125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND The effects of recombinant human endostatin, Endostar, combined with concurrent chemo-radiotherapy (CCRT) on tumor growth, angiogenesis and lymphangiogenesis in a mouse xenograft model of cervical cancer was investigated. METHODS HeLa cells were injected subcutaneously to establish mouse xenograft models and mice were treated with normal saline (control), CCRT with cisplatin (CDDP), Endostar, or a combination of Endostar and CCRT. Growth, metastasis, and angiogenesis of tumors was monitored. RESULTS Tumorogenic activity of tumor cells in the CCRT, Endostar and combination Endostar-CCRT treatment groups was markedly decreased compared with the activity in the NS group (p < 0.05). The most significant inhibition of tumor growth was observed in the Endostar with CCRT group. Lymph node metastases in the Endostar with CCRT group (12.5%) and Endostar alone group (25%) were lower compared to the CCRT group (42.8%) and NS group (66.7%; p < 0.05). Endostar was also found to inhibit tumor angiogenesis. Endostar induced apoptosis of HeLa cells in vivo, and inhibited expression of VEGF and HIF-1alpha in vivo and in vitro. CONCLUSION Endostar enhanced the anti-cancer effect of CCRT in a mouse xenograft model of cervical cancer. These findings thus provide a new strategy to treat cervical cancer.
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Ren S, Ma SL. A novel oxo-bridged Mn4 mixed salt, {[(n-Bu4N)(ClO4)]2[Mn4O6(Tacn)4](ClO4)4} · 2H2O and its analogue Mn4 cluster [Mn4O6(Tacn)4](ClO4)4 · 2H2O (Tacn = 1,4,7-triazacyclononane). RUSS J COORD CHEM+ 2010. [DOI: 10.1134/s1070328410110126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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116
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Ma SL, Ren S. Magnetic study of a cyano-bridged bimetallic complex with Cu2+ macrocycle and [Fe(CN)6]3− ions as building blocks. RUSS J INORG CHEM+ 2010. [DOI: 10.1134/s0036023610080206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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117
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Su C, Zhou S, Zhang L, Ren S, Zhou C. ERCC1, RRM1, and BRCA1 mRNA expression levels and clinical outcome of advanced non-small cell lung cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e18045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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118
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Zhou S, Ren S, Yan L, Zhang J, Zhou C. The relationship of EGFR intron 1 (CA) and microsatellite polymorphism and the efficacy of EGFR-TKI in advanced NSCLC patients. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e18051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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119
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Zhou C, Wu Y, Chen G, Feng J, Liu X, Wang C, Zhang S, Wang J, Zhou S, Ren S. Preliminary results of randomized phase III study comparing efficacy and safety of first-line erlotinib versus carboplatin (CBDCA) plus gemcitabine (GEM) in Chinese advanced non-small cell lung cancer (NSCLC) patients (pts) with EGFR-activating mutations (OPTIMAL). J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.7575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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120
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Ma SL, Ren S. Novel ladder-like structure motif assembled from edge-sharing rhombus and square of Mo2Dy2 based on [Mo(CN)8]4− and Dy3+ ions as building blocks. RUSS J COORD CHEM+ 2010. [DOI: 10.1134/s1070328410010100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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121
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Ma SL, Ren S. Two octacyanomolybdate(IV)-M(II) (M = Mn, Co) bimetallic assemblies: Crystal structures and magnetic properties. RUSS J COORD CHEM+ 2009. [DOI: 10.1134/s1070328409100091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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122
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Zhou S, Ren S, Zhang L, Sun H, Zhou C. The efficacy of chemotherapy in the advanced NSCLC patients who failed with the treatment of EGFR-TKI. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e19078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e19078 Background: EGFR-TKI such as gefitinib and erlotinib were used as standard 2nd/3rd line therapy in previously treated NSCLC. However, those who benefit from EGFR-TKI will inevitably progress from the disease. We reported the efficacy of chemotherapy(CT) in the advanced NSCLC pts failed with the previously 2nd/3rd line treatment of EGFR-TKIs. Methods: Eligibility criteria included advanced NSCLC pts who got disease control(included CR, PR or SD) initially from TKI therapy and then progressed, PS = 0–2, and normal fatal organ function. Pts received systemic CT (docetaxal, pemetrexed, gemicitabine, novelbine or combined with platinum agent) until disease progression or unacceptable toxicity. Results: 32 pts were enrolled from Oct 15 2007 to Nov 30 2008. Demographics: M 56.3%/F 43.7%; median age 56 y [range 34–72]; stage IV 100%; PS 0/1/2: 3 (9.4%)/22(68.8%)/7(21.8%); adenocarcinoma/non-adenocarcinoma 29(90.6%)/3(9.4%); EGFR-TKI treatment duration >6 m 20(62.5%) /< 6 m 12(37.5%); monotherapy 16 (50%)/ doublets 16 (50%). All pts were evaluable for efficacy; partial response in 5 cases (15.6%), stable disease in 21 cases(37.5%), progressive disease in 15 (46.9%) ( Table ). The response of CT was not related with gender, age, regimens, but these with TKI treatment > 6 m achieved a significantly better response than those < 6 m(p=0.01) and these with PS 0–1 got a marginally significantly better response than PS 2(p=0.095). The toxicity was acceptable. Median progression free survival was 3.4 months and it was not correlated with the gender, age and regimens, but PFS were significant longer in the pts received > 6 m of TKI (median 4.8 vs 1.9, p=0.009) and with PS 0–1 (median 4.7 vs 1.9, p=0.002). Conclusions: Pts benefited from TKI therapy and developed progressive disease could also benefit from CT. The response duration of EGFR-TKI and performance status could be predictive for the better efficacy of CT. [Table: see text] No significant financial relationships to disclose.
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Ren S. A tiered approach for aquatic risk assessment of alcohol ethoxylates. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2008; 71:187-199. [PMID: 18022692 DOI: 10.1016/j.ecoenv.2007.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 09/13/2007] [Accepted: 10/03/2007] [Indexed: 05/25/2023]
Abstract
An environmental risk assessment approach for alcohol ethoxylate (AE) mixtures was recently published which required the concentrations of the AE homologues in a mixture. The application of this approach can be limited in certain circumstances because AE homologue concentrations would generally not be available without environmental monitoring and would be difficult to estimate by exposure modeling. A tiered assessment approach was proposed in this study which required AE homologue concentrations only in the last tier. A key parameter in the tiered approach was based on Monte Carlo simulation in which simulated AE mixtures were decomposed into plausible combinations of homologues. The value of this parameter was determined so that the probability of false-negative conclusions in the tiered risk assessment approach was minimized. The use of the tiered approach was demonstrated.
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Ren S, Zhang L, Zhou C, Zhou S, Sun H. The efficacy and safety of loading dose ibandronate in the treatment of non-small cell lung cancer metastatic bone pain(MBP). J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.19127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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125
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Zhou C, Ren S, Zhou S, Zhang L, Zhang Z, Deng Q, Zhang J. Genotyping single-nucleotide polymorphisms (SNPs) in ERCC1 and XRCC3 genes for efficacy prediction in chemotherapy of non-small cell lung cancer (NSCLC). J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.8098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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126
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Guo J, Zhou C, Deng Q, Ren S, Zhang J. Effect of EGFR mutations on gefitinib in advanced previous treated non-small-cell lung cancer. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.19132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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127
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Zhou S, Zhou C, Ren S, Yan L, Zhang L. Predictive effects of serum VEGF, TGF-a and EGFR mutations in advanced non-small cell lung cancer treated by erlotinib. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.19133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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128
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Ren S. Probabilistic risk assessment for zinc in some commercial dishwashing detergents: the anaerobic digestion processes in US POTWs. CHEMOSPHERE 2008; 71:589-600. [PMID: 17959223 DOI: 10.1016/j.chemosphere.2007.09.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 08/31/2007] [Accepted: 09/12/2007] [Indexed: 05/25/2023]
Abstract
A US patent was issued to a commercial dishwashing detergent composition in which soluble zinc serves as an anti-corrosion agent. Since the detergents are used in a down-the-drain fashion, some of the detergents are discharged as wastewater and treated in publicly owned treatment works (POTWs). A risk assessment was previously conducted which focused on the nitrification processes in US POTWs. As a conservative pollutant, zinc removed from wastewater during treatment is transferred to sludges and at sufficiently high concentrations may inhibit the sludge treatment processes. In the present assessment, a probabilistic risk assessment was conducted to quantitatively determine the risk of zinc in the detergents to the anaerobic digestion processes in US POTWs. The procedure for POTW local limit development designed by the US Environmental Protection Agency (EPA) was used as a reference when conducting the risk assessment. The assessment took into account the background zinc concentrations in POTW influents and was conducted at different market penetration rates (MPRs) for the US market of detergents based on the patented formula. Several factors were present that contributed to the conservativeness of the assessment. Results indicate that zinc in detergents does not present a significant risk to the anaerobic digestion processes in POTWs at a MPR up to 10%, with a probability of anaerobic digestion inhibition of below 1%.
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Zhou G, Ren S, Chen N, Duan L, Zhang Z, Fang S, Zhao W. Cerebral White Matter Lesions and Cognitive Function in a Non-demented Chinese Veteran Cohort. J Int Med Res 2008; 36:115-22. [PMID: 18230275 DOI: 10.1177/147323000803600115] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This study examined the association between cerebral white matter lesions (WMLs) and cognitive function in a male, non-demented Chinese veteran cohort. A total of 662 participants underwent CT scan and cognitive function assessments; 51 were excluded from the analysis because they exhibited non-lacunar infarcts or suspected dementia. Subjects were allocated to one of four groups according to WML status and between-group comparisons were made for seven cognitive function tests. Logistic regression was used to assess odds ratios for impaired performance associated with WML status. In all cognitive tests, subjects with severe WMLs differed significantly from those without WMLs or with mild WMLs, and in three tests subjects with severe WMLs differed significantly from those with moderate WMLs. For each cognitive test severe WMLs were strongly associated with increased risk of impaired performance. Severe WMLs were associated with greater diminished cognitive function and there may be a WML threshold after which, in elderly Chinese subjects, an impact on cognitive function occurs.
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Sun Y, Kong F, Ren S, Yuan F, Liang F, Liu N, Jin L, Xi Y. Severe acute graft-vs-host disease in a patient with acute monocytic leukemia having a recombination event between HLA-A/B loci from a multiple recombinant family. ACTA ACUST UNITED AC 2007; 70:499-505. [PMID: 17990988 DOI: 10.1111/j.1399-0039.2007.00953.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human leukocyte antigen (HLA) recombination, particularly multiple recombinations can produce novel haplotypes, thereby complicating donor-recipient selection and possibly inducing severe graft-vs-host disease (GVHD) after nonfully matched allogeneic hematopoietic stem cell transplantation. Here, we report for the first time that a 30-year-old female acute monocytic leukemia patient with an HLA-A/B recombinant haplotype, who has three unmatched and one HLA-B/DRB1 recombinant haplotype siblings, presented grade IV acute GVHD (aGVHD) after transplantation from a sibling with a single allele only mismatch at the classical HLA-A locus. Furthermore, using a new three-dimensional structure modeling application, we inferred that the structural differences in peptide-binding and T-cell receptor interaction sites can significantly change the immunogenicity of mismatched HLA molecules, potentially one of the main causes of aGVHD.
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Wu S, Ren S, Nguyen L, Adams JS, Hewison M. Splice variants of the CYP27b1 gene and the regulation of 1,25-dihydroxyvitamin D3 production. Endocrinology 2007; 148:3410-8. [PMID: 17395703 DOI: 10.1210/en.2006-1388] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The cytochrome P450 25-hydroxyvitamin D3-1alpha-hydroxylase (CYP27b1) plays a pivotal role in vitamin D physiology by catalyzing synthesis of active 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. In common with other P450s, CYP27b1 is known to exhibit alternative splicing. Here we have cloned and sequenced several novel intron 2-containing, noncoding splice variant mRNAs for CYP27b1 in 1,25(OH)2D3-producing HKC-8 human proximal tubule and THP-1 monocytic cells. Regulation of 1,25(OH)2D3 synthesis in these cell lines by calciotropic and noncalciotropic factors was associated with altered expression of the CYP27b1 splice variants. To assess the functional significance of this, HKC-8 cells were transfected with short hairpin RNA (shRNA) to inhibit mRNAs containing sequences from intron 2. This resulted in a significant increase in the expression of CYP27b1 protein and synthesis of 1,25(OH)2D3 by HKC-8 cells compared with control cells for two different intron 2-containing shRNAs (both P<0.001). shRNA to intron 2 had no significant effect on the levels of wild-type CYP27b1 mRNA, suggesting a posttranscriptional mechanism of action. By contrast, shRNA to wild-type CYP27b1 suppressed transcription and activity of the enzyme by 70 and 31%, respectively (both P<0.01). These data indicate that noncoding splice variants of CYP27b1 are functionally active and may play a significant role in the regulation of 1,25(OH)2D3 synthesis during normal physiology.
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Ren S. Probabilistic risk assessment for zinc in some commercial dishwashing detergents: the nitrification processes in US POTWs. CHEMOSPHERE 2007; 68:1474-88. [PMID: 17512032 DOI: 10.1016/j.chemosphere.2007.03.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Revised: 03/16/2007] [Accepted: 03/20/2007] [Indexed: 05/15/2023]
Abstract
A US patent was issued to a commercial dishwashing detergent composition in which soluble zinc is used to protect glassware from corrosion. Some of the consumed detergents are discharged as wastewater and treated in publicly owned treatment works (POTWs). A probabilistic risk assessment was conducted to quantitatively determine the risk of zinc in the detergents to the nitrification processes in US POTWs. The procedure for POTW local limit development designed by the US Environmental Protection Agency (EPA) was used as a reference when conducting the risk assessment. The assessment took into account the background zinc concentrations in POTW influents and potential shock loading patterns, and was conducted at different market penetration rates (MPRs) for the US market of detergents based on the patented formula. The assessment involved several conservative factors including conservative determination of primary treatment efficiency, bioavailability, inhibition concentration, configuration of the nitrification process, as well as background zinc concentration in wastewater. With the conservative factors in the assessment, it was found that zinc in detergents does not present a significant risk to the nitrification processes in POTWs at a MPR up to 10%. It was noted that additional analyses would be required when the MPR is higher than 10% to adequately account for the effects of the conservative factors on the result of the assessment.
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Xin C, Ren S, Eberhardt W, Pfeilschifter J, Huwiler A. FTY720 suppresses interleukin-1beta-induced secretory phospholipase A2 expression in renal mesangial cells by a transcriptional mechanism. Br J Pharmacol 2007; 150:943-50. [PMID: 17325654 PMCID: PMC2013874 DOI: 10.1038/sj.bjp.0707171] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE FTY720 is a potent immunomodulatory prodrug that is converted to its active phosphorylated form by a sphingosine kinase. Here we have studied whether FTY720 mimicked the action of sphingosine-1-phosphate (S1P) and exerted an anti-inflammatory potential in renal mesangial cells. EXPERIMENTAL APPROACH Prostaglandin E(2) (PGE(2)) was quantified by an enzyme-linked immunosorbent-assay. Secretory phospholipase A(2) (sPLA(2)) protein was detected by Western blot analyses. mRNA expression was determined by Northern blot analysis and sPLA(2)-promoter activity was measured by a luciferase-reporter-gene assay. KEY RESULTS Stimulation of cells for 24 h with interleukin-1beta (IL-1beta) is known to trigger increased PGE(2) formation which coincides with an induction of the mRNA for group-IIA-sPLA(2) and protein expression. FTY720 dose-dependently suppressed IL-1beta-induced IIA-sPLA(2) protein secretion and activity in the supernatant. This effect is due to a suppression of cytokine-induced sPLA(2) mRNA expression which results from a reduced promoter activity. As a consequence of suppressed sPLA(2) activity, PGE(2) formation is also reduced by FTY720. Mechanistically, the FTY720-suppressed sPLA(2) expression results from an activation of the TGFbeta/Smad signalling cascade since inhibition of the TGFbeta receptor type I by a specific kinase inhibitor reverses the FTY720-mediated decrease of sPLA(2) protein expression and sPLA(2) promoter activity. CONCLUSIONS AND IMPLICATIONS In summary, our data show that FTY720 was able to mimic the anti-inflammatory activity of TGFbeta and blocked cytokine-triggered sPLA(2) expression and subsequent PGE(2) formation. Thus, FTY720 may exert additional in vivo effects besides the well reported immunomodulation and its anti-inflammatory potential should be considered.
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Ren S, Hesk D, McNamara P, Koharski D. A simple and efficient synthesis of [3α-3H]5α-androst-16-en-3β-ol. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.1117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Sangle G, Zhu F, Ren S, Shen G. Mo-P2:188 Involvement of RAF/ERK pathway in production of plasminogen activator inhibitor-1 in vascular endothelial cells induced by oxidized or glycated LDL. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)80323-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hall EA, Ren S, Hylemon PB, Redford K, del Castillo A, Gil G, Pandak WM. Mitochondrial cholesterol transport: A possible target in the management of hyperlipidemia. Lipids 2005; 40:1237-44. [PMID: 16477808 DOI: 10.1007/s11745-005-1491-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sterol 27-hydroxylase (CYP27A1) may defend cells against accumulation of excess cholesterol, making this enzyme a possible target in the management of hyperlipidemia. The study objective was to analyze cholesterol homeostatic responses to increases in CYP27A1 activity in HepG2 cells and primary human hepatocytes. Increasing CYP27A1 activity by increasing enzyme expression led to significant increases in bile acid synthesis with compensatory increases in HMG-CoA reductase (HMGR) activity/protein, LDL receptor (LDLR) mRNA, and LDLR-mediated cholesterol uptake. Under these conditions, only a small increase in cellular 27-hydroxycholesterol (27OH-Chol) concentration was observed. No changes were detected in mature sterol regulatory element-binding proteins (SREBP) 1 or 2. Increasing CYP27A1 activity by increasing mitochondrial cholesterol transport (i.e., substrate availability) led to greater increases in bile acid synthesis with significant increases in cellular 27OH-Chol concentration. Mature SREBP 2 protein decreased significantly with compensatory decreases in HMGR protein. No change was detected in mature SREBP 1 protein. Despite increasing 27OH-Chol and lowering SREBP 2 protein concentrations, LDLR mRNA increased significantly, suggesting alternative mechanisms of LDLR transcriptional regulation. These findings suggest that regulation of liver mitochondrial cholesterol transport represents a potential therapeutic strategy in the treatment of hyperlipidemia and atherosclerosis.
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Takimoto E, Champion HC, Li M, Ren S, Rodriguez ER, Tavazzi B, Lazzarino G, Paolocci N, Gabrielson KL, Wang Y, Kass DA. Pressure Overload and Cardiac Remodelling—A Smoking Gun Points to Uncoupled Nitric Oxide Synthase. J Am Soc Nephrol 2005; 16:2820-2823. [PMID: 37000921 DOI: 10.1681/01.asn.0000926756.36912.0b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
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Hall EA, Ren S, Hylemon PB, Rodriguez-Agudo D, Redford K, Marques D, Kang D, Gil G, Pandak WM. Detection of the steroidogenic acute regulatory protein, StAR, in human liver cells. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1733:111-9. [PMID: 15863358 DOI: 10.1016/j.bbalip.2005.01.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 12/16/2004] [Accepted: 01/20/2005] [Indexed: 11/30/2022]
Abstract
Overexpressing StAR (a mitochondrial cholesterol transporter) increases (>5-fold) the rate of 27-hydroxylation of cholesterol and the rates of bile acid synthesis in primary rat hepatocytes; suggesting that the transport of cholesterol into mitochondria is rate-limiting for bile acid biosynthesis via the CYP27A1 initiated 'acidic' pathway. Our objective was to determine the level of StAR expression in human liver and whether changes in StAR would correlate with changes in CYP27A1 activity/bile acid synthesis rates in human liver tissues. StAR mRNA and protein were detected in primary human hepatocytes and HepG2 cells by RT-PCR/Northern analysis and by Western analysis, respectively. In immunocompetition assays, liver StAR was competed away with the addition of purified human adrenal StAR. Overexpressing CYP27A1 in both cell types led to >2-fold increases in liver StAR concentration. StAR protein levels also increased approximately 2-fold with the addition of 27-hydroxycholesterol to HepG2 cell culture medium. Overexpressing StAR increased the rates of 27-hydroxylation of cholesterol/bile acid synthesis in both cell lines and increased intracellular levels of 27-hydroxycholesterol. In conclusion, human liver cells contain regulable StAR protein whose level of expression appears capable of regulating cellular cholesterol homeostasis, representing a potential therapeutic target in the management of hyperlipidemia.
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Ren S, Terman DS, Bohach G, Silvers A, Hansen C, Colt H, Sahn SA. Intrapleural Staphylococcal Superantigen Induces Resolution of Malignant Pleural Effusions and a Survival Benefit in Non-Small Cell Lung Cancer. Chest 2004; 126:1529-39. [PMID: 15539723 DOI: 10.1378/chest.126.5.1529] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Malignant pleural effusion (MPE) may occur in up to 50% of patients with non-small cell lung cancer (NSCLC). The majority of these patients have a poor performance status and a dismal prognosis, with survival duration ranging from 2 to 3 months. Since these patients are typically symptomatic from their MPE, prompt treatment is required. Patients with symptomatic MPE from NSCLC and poor performance scores (Eastern Cooperative Oncology Group [ECOG] score >/= 2, Karnofsky performance status [KPS] score < 50) are generally not offered systemic chemotherapy. Treatment is palliative and includes intrapleural catheter drainage or chemical pleurodesis with talc, doxycycline, or bleomycin. None of the latter modalities prolong survival. OBJECTIVE Our goal was to investigate the toxicity and therapeutic effect of a new therapeutic agent, Staphylococcus aureus superantigen (SSAg), a powerful T-cell stimulant administered intrapleurally to unselected, consecutive patients with MPE from NSCLC (stage IIIb with pleural effusion) and a poor performance status. By providing direct access of the SSAg to the bronchial and mediastinal lymphatics, we predicted that intrapleural administration of SSAg would induce resolution of MPE and prolong survival in this population with advanced NSCLC and a limited prognosis. METHODS Fourteen consecutive, unselected patients with MPE from NSCLC and a median pretreatment KPS score of 40 (range, 10 to 60) received pleural instillation of SSAg, 100 to 400 pg, once or twice weekly (mean, 3.7 +/- 1.3 treatments [+/- SD]) until the pleural effusions resolved. They were evaluated for drug toxicity, resolution, duration of MPE, and survival. RESULTS Other than mild fever (maximum grade 2), toxicity of SSAg treatment was trivial and notably devoid of respiratory distress or hypotension. Eleven patients had a complete response (CR), and 3 patients had a partial response of their MPE. In 12 patients, the response endured for > 90 days, with a median time to recurrence of 5 months (range, 3 to 23 months). The median survival for the SSAg-treated group was 7.9 months (range, 2 to 36 months; 95% confidence interval [CI], 5.9 to 11.4 months), compared to a median survival of 2.5 months (range, 0.1 to 57 months; 95% CI, 1.3 to 3.4 months) for 18 consecutive, unselected patients with MPE from NSCLC (stage IIIb) treated with talc poudrage (p = 0.044). Survival duration of all 14 SSAg-treated cases and 13 talc-poudrage-treated patients with comparable pretreatment KPS (range, 10 to 60; median, 40 and 30, respectively), and distribution (p = 0.5) was 7.9 months (95% CI, 5.9 to 11.4 months) and 2.0 months (95% CI, 0.4 to 2.9 months), respectively (p = 0.0023). Nine of 14 patients treated with SSAg survived > 6 months, 4 patients survived > 9 months, and 3 patients survived > 350 days. One of the patients in the CR group has survived 36 months. None of the 13 talc-treated patients survived > 6 months. INTERPRETATION In 14 unselected, consecutive patients with MPE from NSCLC and poor pretreatment performance (median KPS of 40), the intrapleural administration of SSAg was efficacious in resolving the MPE without any clinically important adverse effects. SSAg-treated patients with a median KPS of 40 (range, 10 to 60) had a median survival that exceeded that with talc poudrage, and was comparable to current systemic chemotherapy used in patients with KPS >/= 70 status. SSAg treatment is simple to perform, minimally invasive, and does not require hospital time. It may be an attractive alternative to existing palliative modalities for stage IIIb patients with MPE and poor performance who are not candidates for systemic chemotherapy.
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Jacquard AC, Nassal M, Pichoud C, Ren S, Schultz U, Guerret S, Chevallier M, Werle B, Peyrol S, Jamard C, Rimsky LT, Trepo C, Zoulim F. Effect of a combination of clevudine and emtricitabine with adenovirus-mediated delivery of gamma interferon in the woodchuck model of hepatitis B virus infection. Antimicrob Agents Chemother 2004; 48:2683-92. [PMID: 15215126 PMCID: PMC434178 DOI: 10.1128/aac.48.7.2683-2692.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Our aim was to evaluate the antiviral effect of a combination of two nucleoside reverse transcriptase inhibitors, emtricitabine (FTC) and clevudine (L-FMAU), with the addition of an adenovirus-driven delivery of recombinant gamma interferon (IFN-gamma) in the woodchuck model of hepatitis B virus infection. Six woodchuck hepatitis virus (WHV)-infected woodchucks received L-FMAU (10 mg/kg) plus FTC (30 mg/kg) intraperitoneally for 8 weeks; six other animals received in addition an intravenous injection of a recombinant adenovirus vector expressing woodchuck IFN-gamma (Ad-IFN) at weeks 4 and 8. In the control group, two animals received Ad-IFN alone, two received adenovirus vector expressing the green fluorescent protein reporter gene, and one remained untreated. In less than 2 weeks, all woodchucks that received L-FMAU plus FTC showed a rapid and marked inhibition of viral replication, with a 4-log(10) drop in serum WHV DNA. In two animals, viremia remained suppressed for several months after the end of treatment. Similarly, a dramatic decrease in intrahepatic replicative intermediates of viral DNA was observed in the L-FMAU/FTC-treated groups. The additional administration of Ad-IFN led to increased inflammation in the liver but did not enhance the antiviral effect of the L-FMAU/FTC combination. In conclusion, therapies combining L-FMAU and FTC in WHV-infected woodchucks resulted in a potent and sustained antihepadnaviral effect both in the liver and in the blood circulation. However, no extra benefit of adding IFN-gamma gene transduction to the L-FMAU/FTC combination could be detected.
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Wu QB, Ren S, Deng SZ, Chen J, She JC, Xu NS. Template-based synthesis of carbon nanofibres and their field emission characteristics. SURF INTERFACE ANAL 2004. [DOI: 10.1002/sia.1726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ren S, Schultz TW, Frymier PD. Evaluation of the Shk1 activated sludge bacterial luminescence inhibition assay: narcotic chemicals. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2004; 72:1187-1194. [PMID: 15362448 DOI: 10.1007/s00128-004-0369-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Shen J, Shu N, Ren S, Zhou X, Zhou X. Development of a surface acoustic wave LB membrane immunity sensor. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 2003; 20:20-2. [PMID: 12845747 DOI: 10.1007/bf02887666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A new kind of biosensor for immunology was developed by ultrasonic technique and LB membrane. A double delay-line resonator was made by using ST-cut quartz crystal with working frequency of 149.7 MHz. Then a layer of LB membrane was covered on it. When anti-IgM antibody of various concentrations was added to it, the sensor can be used to detect IgM antigen. The biosensor was highly sensitive, small and light. The experimental results showed that the working frequency change of the sensor was proportional to the concentration of antibody with its dilution ratio between 1:10,000 and 1:100. It was also first observed that the frequency curve of the sensor resulting from the reaction of IgM antigen and antibody undulated in the experiment.
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Li ZB, Liu XW, Xu NS, Deng SZ, Chen J, Wu MM, Ren S, Chen J, Zhao FL. Resonant field emission through amorphous diamond thin films (a model study). Ultramicroscopy 2003; 95:75-80. [PMID: 12535547 DOI: 10.1016/s0304-3991(02)00299-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A model for field emission through an amorphous diamond thin film with defects is constructed. Theoretical study shows that the emission is enhanced by attractive defects which would make the resonant emission observable for films with thickness of about 10nm. The emitted current density in typical parameters is calculated as functions of thickness, field strength and defect density. The energy distribution of emitted electrons is attained.
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Ren S. Classifying class I and class II compounds by hydrophobicity and hydrogen bonding descriptors. ENVIRONMENTAL TOXICOLOGY 2002; 17:415-423. [PMID: 12242671 DOI: 10.1002/tox.10074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The successful development of quantitative structure-activity relationships (QSARs) and the prediction of toxicity based on QSARs depend on the correct classification of the mechanism of toxic action of chemical compounds. The toxicity mechanism of a compound can be determined by a few existing methods, such as studying the chemical structure of the compound for certain substructures and assigning a mechanism accordingly. However, these methods are less reliable for compounds with complex structures and are usually complicated. A novel descriptor-based method employing a multivariate statistical technique--discriminant analysis--was developed in this study for the classification of class I and class II compounds. The discriminating variables used in discriminant analysis were the hydrophobicity descriptor log(K(ow)) and the hydrogen bonding descriptors E(LUMO), E(HOMO), Q(+), and Q(-). Because only numerical values of these descriptors are required for this method, which can be calculated, no additional experimental work was required for the toxicity mechanism classification of new compounds. A nonlinear discriminant function was generated that could not be expressed explicitly. Assessing the predicting ability of the discriminant function by the cross-validation method showed that a low total error rate, 4.2% was achieved.
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Ren S. Determining the mechanisms of toxic action of phenols to Tetrahymena pyriformis. ENVIRONMENTAL TOXICOLOGY 2002; 17:119-127. [PMID: 11979590 DOI: 10.1002/tox.10040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Phenols are environmentally important compounds that are widely used in agriculture and industry. Thus, phenols are of interest to environmental toxicologists, which has led to the development of several quantitative structure-activity relationship (QSAR) models. The most successful QSARs have been established for compounds having a common mechanism of toxic action (MOA). However, correctly determining the MOA of a compound is not easy. Discriminant analysis was used in this study to separate phenols by their MOAs. The working hypothesis of this study was that phenols with different MOAs lie in different regions in the response surface described by the ionization-corrected hydrophobicity descriptor, log D, the electrophilicity descriptor, ELUMO, and the interaction between hydrophobicity and electrophilicity, D * ELUMO. Results of discriminant analysis showed a total error rate of 15%. In addition, it was difficult to separate phenols that had a polar narcosis MOA from phenols that had a proelectrophile MOA.
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Picardeau M, Ren S, Saint Girons I. Killing effect and antitoxic activity of the Leptospira interrogans toxin-antitoxin system in Escherichia coli. J Bacteriol 2001; 183:6494-7. [PMID: 11591696 PMCID: PMC100147 DOI: 10.1128/jb.183.21.6494-6497.2001] [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: 11/20/2022] Open
Abstract
We report the first evidence of a chromosome-encoded toxin-antitoxin locus in spirochetes. This locus has been found in the pathogenic spirochete Leptospira interrogans and exhibits homologies with the pem/chp loci. The L. interrogans chp locus consists of two genes: chpK (for "killer protein") and its upstream partner chpI (for "inhibitory protein"). Expression of ChpK in Escherichia coli results in the inhibition of bacterial growth. The coexpression of ChpI neutralizes ChpK toxicity. By Southern blot analysis, chp homologs were found in all representative pathogenic strains of L. interrogans.
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Ren S, Lien EJ. Development of HIV protease inhibitors: a survey. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2001; Spec No:1-34. [PMID: 11548206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
In the treatment of infections caused by rapidly mutating viruses like human immunodeficiency virus (HIV), combination therapy with multiple drugs acting by different mechanisms offers several advantages over monotherapy. It may provide: synergistic effect, possible reduction of dosages and side-effects, and reduction of the chance of drug resistance. In the past few years, hundreds of HIV protease inhibitors have been synthesized and tested in order to overcome the limitations of reverse transcriptase inhibitors like zidovudine and others. In this review, emphasis is placed on the development of HIV protease inhibitors as antiviral agents against HIV, and structure-activity relationship analysis of saquinavir and related compounds. Limitations of some protease inhibitors and ways to overcome the shortcomings are presented. Among these many protease inhibitors five have been marketed during 1995-1999. They are saquinavir, ritonavir, indinavir, nelfinavir and amprenavir. Their different structural features, important physicochemical, pharmacokinetic and clinical profiles are presented in a table form for easy comparison. It is hoped that in the future new drugs based on additional mechanisms can be developed for the treatment of AIDS.
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Ren S, Tokes ZA, Csipke C, Zhou B, Yen Y, Lien EJ. Inhibition of tumor cell growth by Schiff bases of hydroxysemicarbazide. Anticancer Res 2001; 21:3445-51. [PMID: 11848507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The inhibitory activities of Schiff bases of hydroxysemicarbazide (HSC) against eight human and murine tumor cell lines and one non-cancer cell line were studied using MTS/PES microculture tetrazolium and methylene blue assays. Compounds 1 (1-[9-(10-methylanthryl)methylene]-4-HSC), 2 (1-[2-hydroxy-3,5-dibromobenzylidene]-4-HSC) and 3 (1-[2,3,4-trihydroxybenzylidene]-4-HSC), which have been shown to be active against murine leukemia L1210 cells in our laboratories, inhibited human leukemia CCRF-CEM cells with similar IC50s ranging from 2.7 to 7.0 microM. Of the compounds tested against attached tumor cell lines (B16, CHO, HT29, ZR75) at 50 microM concentration, compound 1 showed the strongest inhibition, followed by 4 (1-[2-(5-nitrothienyl)methylene]-4-HSC), 2 and 5 (1-[2-hydroxy-3,5-diiodobenzylidene]-4-HSC) with more than 50% inhibition. The IC50s of compound 1 were found to range from 2.7 to 12 microM against the attached tumor cell lines examined. As compared with hydroxyurea, compound 1 had more favorable selectivity against tumor cells. Further more, compound 1 was found to have IC50s of 2.8 and 6.5 microM against hydroxyurea-resistant and gemcitabine-resistant KB cells, respectively, but had no cross-resistance with hydroxyurea and gemcitabine (two known ribonucleotide reductase inhibitors acting at different sites of the same enzyme). In conclusion, several Schiff bases of HSC showed inhibition of tumor cell growth at micromolar concentration and had no cross-resistance with hydroxyurea-resistant KB cells.
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Liu Z, Short J, Rose A, Ren S, Contel N, Grossman S, Unger S. The simultaneous determination of diazepam and its three metabolites in dog plasma by high-performance liquid chromatography with mass spectroscopy detection. J Pharm Biomed Anal 2001; 26:321-30. [PMID: 11470209 DOI: 10.1016/s0731-7085(01)00404-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A fast, sensitive and specific LC/MS/MS method for the simultaneous determination of diazepam and its three metabolites, oxazepam, temazepam and desmethyldiazepam, in dog plasma is described. The method consists of an automated 96-well solid phase extraction procedure and electrospray LC/MS/MS analysis. D(5)-Diazepam is used as the internal standard for all the compounds. Intra-day and inter-day assay coefficients of variations are less than 12.7%. The lower limit of quantitation (LLOQ) is 1 nM for each analyte, based on 0.1 ml aliquots of dog plasma. The analytical run time was 5 min. Linearity is observed over the range of 1--500 nM. This method has been used to support the discovery of pharmacokinetic studies.
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