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Tu B, Pang Q, Wu D, Song Y, Weng L, Li Q. Ordered Vacancies and Their Chemistry in Metal–Organic Frameworks. J Am Chem Soc 2014; 136:14465-71. [DOI: 10.1021/ja5063423] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Wu D, Guo Z, Yin X, Pang Q, Tu B, Zhang L, Wang YG, Li Q. Metal-organic frameworks as cathode materials for Li-O2 batteries. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:3258-62. [PMID: 24616022 DOI: 10.1002/adma.201305492] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 12/30/2013] [Indexed: 05/24/2023]
Abstract
Metal-organic frameworks (MOFs) with open metal sites enrich the population of O2 in the pores significantly and assist the Li-O2 reaction when employed as a cell electrode material. A primary capacity of 9420 mA h g(-1) is achieved in a cell with Mn-MOF-74; more than four times higher than the value obtained in a cell without an MOF.
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Song Y, Yin X, Tu B, Pang Q, Li H, Ren X, Wang B, Li Q. Metal–organic frameworks constructed from mixed infinite inorganic units and adenine. CrystEngComm 2014. [DOI: 10.1039/c3ce42556h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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54
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Zhao L, Liu W, Gong L, Liu Z, Yuan Z, Wang P, Pang Q, Wang J, Wang P. Is Postoperative Radiation Therapy Necessary for Patients With Completely Resected Small Cell Lung Cancer?: A Retrospective Analysis. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.1385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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55
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Guo F, Li J, Zhang S, Du W, Amarachintha S, Sipple J, Phelan J, Grimes HL, Zheng Y, Pang Q. mTOR kinase inhibitor sensitizes T-cell lymphoblastic leukemia for chemotherapy-induced DNA damage via suppressing FANCD2 expression. Leukemia 2013; 28:203-6. [PMID: 23852546 DOI: 10.1038/leu.2013.215] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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56
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Han J, Zhou L, Pang Q, Yang H. Photoluminescence properties of the red phosphor YInGe 2O 7:Eu 3+. B CHEM SOC ETHIOPIA 2013. [DOI: 10.4314/bcse.v27i2.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Guo F, Li J, Du W, Zhang S, O'Connor M, Thomas G, Kozma S, Zingarelli B, Pang Q, Zheng Y. mTOR regulates DNA damage response through NF-κB-mediated FANCD2 pathway in hematopoietic cells. Leukemia 2013; 27:2040-2046. [PMID: 23538752 DOI: 10.1038/leu.2013.93] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 02/14/2013] [Accepted: 03/20/2013] [Indexed: 12/16/2022]
Abstract
Hematopoietic stem/progenitor cells (HSPCs) function to give rise to mature blood cells. Effective DNA damage response (DDR) and maintenance of genomic stability are crucial for normal functioning of HSPCs. Mammalian target of rapamycin (mTOR) integrates signals from nutrients and growth factors to control protein synthesis, cell growth, survival and metabolism, and has been shown to regulate DDR in yeast and human cancer cells through the p53/p21 signaling cascade. Here, we show that gene targeting of mTOR in HSPCs causes a defective DDR due to a variety of DNA damage agents, mimicking that caused by deficient FANCD2, a key component of the Fanconi anemia (FA) DDR machinery. Mechanistically, mTOR(-/-) HSPCs express drastically reduced FANCD2. Consistent with these genetic findings, inactivation of mTOR in human lymphoblast cells by pp242 or Torin 1, mTOR kinase inhibitors, suppresses FANCD2 expression and causes a defective DDR that can be rescued by reconstitution of exogenous FANCD2. Further mechanistic studies show that mTOR deficiency or inactivation increases phosphorylation and nuclear translocation of nuclear factor (NF)-κB, which results in an enhanced NF-κB binding to FANCD2 promoter to suppress FANCD2 expression. Thus, mTOR regulates DDR and genomic stability in hematopoietic cells through a noncanonical pathway involving NF-κB-mediated FANCD2 expression.
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He Z, Pang Q, Rankine D, Sumby CJ, Zhang L, Doonan CJ, Li Q. Encapsulation of polyoxometalates within layered metal–organic frameworks with topological and pore control. CrystEngComm 2013. [DOI: 10.1039/c3ce41136b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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59
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Wang P, Liu N, Qu C, Zhu L, Wang B, Pang Q, Yuan Z, Zhao L. Prognostic Value of Serial FDG-PET/CT Scanning in Stage I Non-small Cell Lung Cancer Patients Treated With Hypofractionated Radiation Therapy. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Wang P, Liu N, Pang Q, Qu C, Wang B, Guo H. PI3K/AKT Signaling Pathway in the Regulation of Non-small Cell Lung Cancer Radiosensitivity After Hypofractionated Radiation Therapy. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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61
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Zhao L, Yi S, Gong L, Yuan Z, Pang Q, Wang P. Inhibition of TGF-β1 Signaling With Halofuginone can Enhance the Antitumor Effect of Irradiation in Lung Cancer Xenograft. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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62
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Liu Y, Yang Y, Zhang Q, Zhang W, Zhu S, Li X, Pang Q. A study of classification of spontaneous intraventricular haemorrhage: a report of 324 cases. J Clin Neurosci 2012; 5:182-5. [PMID: 18639009 DOI: 10.1016/s0967-5868(98)90035-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/1996] [Accepted: 07/05/1996] [Indexed: 11/18/2022]
Abstract
In order to develop a practical classification of spontaneous intraventricular haemorrhage (IVH), a correlation was made between clinical and computed tomographic (CT) factors in 324 patients with IVH between September 1988 and December 1996. Spontaneous IVH was graded according to age, blood pressure, clinical conditions, conscious state on admission, primary site of bleeding, volume of intraparenchymal haematoma, degree of midline shift, degree of hydrocephalus and location of IVH, producing a score up to 20. A score of 0-5 was Grade I, 6-10 Grade II, 11-15 Grade III, 16-20 Grade IV. The mortality of each Grade, respectively, was 1.6%, 22.5%, 76% and 100%. The authors propose that this grading system may be a practical schema in the evaluation of the prognosis for IVH.
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Ou CB, Pan Q, Pang Q, Chen X, Hou N, He C. Protocatechuic acid, a new active substance against the challenge of avian infectious bursal disease virus. Poult Sci 2012; 91:1604-9. [PMID: 22700505 DOI: 10.3382/ps.2011-02069] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The present study aims to investigate the potential antiviral activity of protocatechuic acid (PCA) and its mechanism against infectious bursal disease virus (IBDV) infection. In the curative test, dosages of PCA of 40, 20, and 10 mg/kg, the survival rate was 90, 90, and 60%, respectively, and the BW gain was 36.63, 31.85, and 51.8%, respectively. The survival rate for the Astragalus polysaccharide (ASP) group was significantly lower than those of the birds treated with 20 mg/kg or 40 mg/kg of PCA. The bursa indeces of chickens in 40 mg/kg, 20 mg/kg, and ASP groups were significantly higher than that of the infection group, whereas a significant increase of the spleen index was found in birds with 20 mg/kg PCA in comparison with other challenged groups. The birds treated with 20 mg/kg or 40 mg/kg of 3,4-dihydroxybenzoic acid also showed slightly higher levels of IBDV clearance in the bursa of Fabricius. Furthermore, the chickens treated with 20 mg/kg of PCA induced a significant lymphocyte proliferation and a significant increase in the CD4+/CD8+ ratio in comparison with the ASP chickens. These results imply that chickens treated with 20 mg/kg of PCA for 5 d could effectively induce active nonspecific immune responses against the IBDV infection.
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Zhang K, Pang B, Xin T, Hou X, Jia J, Feng B, Meng L, Xu S, Pang Q. Increased signal transducer and activator of transcription 3 (STAT3) and decreased cyclin D1 in recurrent astrocytic tumours compared with paired primary astrocytic tumours. J Int Med Res 2012; 39:2103-9. [PMID: 22289525 DOI: 10.1177/147323001103900606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This study compared the levels of signal transducer and activator of transcription 3 (STAT3) and cyclin D1 protein in paired primary and recurrent astrocytic tumours, and analysed their correlation with clinicopathological and treatment factors. A total of 48 samples from 24 patients who had undergone surgical removal of primary and recurrent astrocytic tumours were analysed. Levels of STAT3 and cyclin D1 protein were detected using immunohistochemistry. Increased STAT3 and decreased cyclin D1 levels were observed in recurrent astrocytic tumours compared with their paired primary tumours. There was a significant correlation between higher levels of STAT3 protein and shorter progression-free survival in primary tumours after surgery (r = 0.417), and a significant correlation between decreased cyclin D1 protein levels and radiotherapy in recurrent tumours (r = 0.468). It was concluded that increased STAT3 and decreased cyclin D1 protein levels may contribute to the recurrence of astrocytic tumours. Detection of STAT3 may be useful in predicting progressionfree survival in primary astrocytic tumours after surgery. In addition, radiotherapy may decrease cyclin D1 levels in astrocytic tumours, but the nature of this association requires further investigation.
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Pang Q, Wang P, Wang J, Zhao L, Yuan Z, Wang W, Sun J, Hou H. PO-0743 EGFR TKIS COMBINED WITH DEFINITE RADIOTHERAPY FOR STAGE IV NON-SMALL CELL LUNG CANCER WITH BONE-ONLY METASTASES. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)71076-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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66
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Pang Q, Wei Q, Yuan X, López Guerra J, Gomez D, Yan Z, Liu Z, Mohan R, Komaki R, Liao Z. Functional Promoter rs2868371 Variant of HSPB1 Associates with the Risk of Radiation Pneumonitis in Patients with Non-small Cell Lung Cancer Treated with Radiotherapy. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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67
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Fagerlie S, Lensch MW, Pang Q, Bagby GC. The Fanconi anemia group C gene product: signaling functions in hematopoietic cells. Exp Hematol 2001; 29:1371-81. [PMID: 11750095 DOI: 10.1016/s0301-472x(01)00755-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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68
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Hu YS, Zhang QL, Tian ZG, Wei HM, Li G, Pang Q, Feng JB, Xu XQ, Wang CW, Sun R. [Significance of the unbalanced expression of Th1/Th2 type cytokines in human glioma]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 2001; 23:594-8. [PMID: 12901105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE To study the significance of the unbalanced expression of Th1/Th2 type cytokines in human glioma. METHODS The gene expressions of Th1/Th2 type cytokines in 62 specimens of human glioma tissues, 4 glioma cell lines, peripheral blood mononuclear cell (PBMC) of 15 glioma patients, 5 specimens of normal adult brain tissue and 5 brain meningioma tissues were detected by semiquantitative reverse transcription polymerase chain reaction. IFN-gamma and IL-2 represent Th1 type cytokines. IL-4, IL-6, IL-10 and IL-13 represent Th2 type cytokines. RESULTS There were obviously predominant expression of Th2 type cytokines in glioma cell lines (P < 0.01) and specimens of human glioma tissues (P < 0.01). The tendency of distinct expression of Th2 type cytokines in PBMC was also existent. There wasn't obvious discrepancy of the expression of two type cytokines in normal adult brain tissues and meningioma tissues. CONCLUSIONS It is likely that the switching of Th1/Th2 type cytokines in gliomas as predominant expression of Th2 type cytokine genes is related to the origination of gliomas and the evasion of glioma cells from immune surveillance.
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Hu YS, Zhang QL, Tian ZG, Wei HM, Zhang JH, Li G, Pang Q, Wang CW, Jin P, Sun R. [Influence of adjustment of balance of Th1/Th2 type cytokines on proliferation of glioma cells]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 2001; 23:599-602. [PMID: 12901106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE To study the influence of adjustment of balance of Th1/Th2 by external cytokines on proliferation of glioma cells. METHODS The gene expressions of Th1/Th2 type cytokines in C6, 9L, U251 and SHG44 glioma cells were detected by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). After the cells were induced with IFN-gamma + IL-4 McAb and IL-4 + IFN-gamma McAb respectively, we isolated the total RNA to proceed RT-PCR again. The evaluation of cell proliferation was proceeded by MTT assay method. RESULTS There was obviously predominant expression of Th2 type cytokines in glioma cell lines (P < 0.01). The expression intensity of IFN-gamma was improved in IFN-gamma + IL-4 McAb groups and Th2 type cytokines were enhanced in IL-4 + IFN-gamma McAb groups. IFN-gamma and IL-4 McAb could cause the switch from Th2 to Th1, and could remarkably inhibit the proliferation of glioma cells in a dose-dependent way (P < 0.01). On the other hand, IL-4 and IFN-gamma McAb could strengthen the switch of Th2, and might stimulate the glioma cell growth, also in a dose-dependent way (P < 0.01). CONCLUSIONS There is a Th2 preponderance in glioma cells. IFN-gamma and IL-4 McAb could regulate the switch from Th2 to Th0 or Th1, and inhibit the proliferation of glioma cells.
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Yuan L, He S, Guan C, Pang Q. [The preparation and study on hepatic targeting tendency of galactosyl-anti-CD3-McAb in mice]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2001; 32:424-6. [PMID: 12536583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE This study sought to reduce the recurrence rate of primary liver cacer (PLC) after hepatectomy by increasing the concentration of infiltrating lymphocytes(TILs) at the target organ. METHODS It has been reported that galactosyl-anti-CD3-McAb has an obvious hepatic targeting tendency in vitro. On the basis of that work, the present authors conducted a study in mice. Galactosyl-anti-CD3-McAb was prepared and its carbohydrate density was measured with the phenol-sulphyric acid method, and then anti-CD3-McAb (labeled with 125I) and galactosyl-anti-CD3-McAb (labeled with 131I) were infused respectively via the peripheral vein and the radioactivity in each organ was measured. RESULTS The carbohydrate density of galactosyl-anti-CD3-McAb in this experiment was 58.12, which effectively guaranteed the specific binding between galactosyl-anti-CD3-McAb and hepatic binding protein(HBP). It was also noticed that anti-CD3-McAb tended to aggregate in the lungs while being infused via the peripheral vein, and that galactosyl-anti-CD3-McAb had an obvious hepatic targeting tendency in vivo and it stayed in liver for quite a long period. CONCLUSIONS Galactosyl-anti-CD3-McAb has an obvious hepatic targeting tendency in vivo while being infused through peripheral vein; this may be due to the specific binding between galactose and HBP.
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Pang Q, Christianson TA, Keeble W, Diaz J, Faulkner GR, Reifsteck C, Olson S, Bagby GC. The Fanconi anemia complementation group C gene product: structural evidence of multifunctionality. Blood 2001; 98:1392-401. [PMID: 11520787 DOI: 10.1182/blood.v98.5.1392] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Fanconi anemia (FA) group C gene product (FANCC) functions to protect cells from cytotoxic and genotoxic effects of cross-linking agents. FANCC is also required for optimal activation of STAT1 in response to cytokine and growth factors and for suppressing cytokine-induced apoptosis by modulating the activity of double-stranded RNA-dependent protein kinase. Because not all FANCC mutations affect STAT1 activation, the hypothesis was considered that cross-linker resistance function of FANCC depends on structural elements that differ from those required for the cytokine signaling functions of FANCC. Structure-function studies were designed to test this notion. Six separate alanine-substituted mutations were generated in 3 highly conserved motifs of FANCC. All mutants complemented mitomycin C (MMC) hypersensitive phenotype of FA-C cells and corrected aberrant posttranslational activation of FANCD2 in FA-C mutant cells. However, 2 of the mutants, S249A and E251A, failed to correct defective STAT1 activation. FA-C lymphoblasts carrying these 2 mutants demonstrated a defect in recruitment of STAT1 to the interferon gamma (IFN-gamma) receptor and GST-fusion proteins bearing S249A and E251A mutations were less efficient binding partners for STAT1 in stimulated lymphoblasts. These same mutations failed to complement the characteristic hypersensitive apoptotic responses of FA-C cells to tumor necrosis factor-alpha (TNF-alpha) and IFN-gamma. Cells bearing a naturally occurring FANCC mutation (322delG) that preserves this conserved region showed normal STAT1 activation but remained hypersensitive to MMC. The conclusion is that a central highly conserved domain of FANCC is required for functional interaction with STAT1 and that structural elements required for STAT1-related functions differ from those required for genotoxic responses to cross-linking agents. Preservation of signaling capacity of cells bearing the del322G mutation may account for the reduced severity and later onset of bone marrow failure associated with this mutation.
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Pang Q, Keeble W, Diaz J, Christianson TA, Fagerlie S, Rathbun K, Faulkner GR, O'Dwyer M, Bagby GC. Role of double-stranded RNA-dependent protein kinase in mediating hypersensitivity of Fanconi anemia complementation group C cells to interferon gamma, tumor necrosis factor-alpha, and double-stranded RNA. Blood 2001; 97:1644-52. [PMID: 11238103 DOI: 10.1182/blood.v97.6.1644] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Hematopoietic cells bearing inactivating mutations of Fanconi anemia group C (FANCC) are excessively apoptotic and demonstrate hypersensitivity not only to cross-linking agents but also to interferon gamma (IFN-gamma) and tumor necrosis factor-alpha. Seeking essential signaling pathways for this phenotype, this study quantified constitutive and induced RNA-dependent protein kinase (PKR) activation in Fanconi anemia cells of the C complementation group (FA-C). PKR was constitutively phosphorylated and exhibited an increased binding affinity for double-stranded RNA (dsRNA) in FANCC(-/-) cells. FANCC(-/-) cells were hypersensitive to both dsRNA and the combination of dsRNA and IFN-gamma in that these agents induced a higher fraction of apoptosis in FANCC(-/-) cells than in normal cells. Overexpression of wild-type PKR-sensitized FANCC(-/-) cells to apoptosis induced by IFN-gamma and dsRNA. Conversely, inhibition of PKR function by enforced expression of a dominant-negative inhibitory mutant of PKR (PKRDelta6) substantially reduced the IFN and dsRNA hypersensitivity of FANCC(-/-) cells. Two PKR target molecules, IkappaB-alpha and IRF-1, were not differentially activated in FANCC(-/-) cells, but enforced expression of a nonphosphorylatable form of eukaryotic translation initiation factor-2alpha reversed the PKR-mediated block of messenger RNA translation and partially abrogated the PKR-mediated apoptosis in FANCC(-/-) cells. Because no evidence was found of a PKR/FANCC complex in normal cells, it was concluded that an essential function of FANCC is to suppress, indirectly, the activity of PKR and that FANCC inactivation results in IFN hypersensitivity, at least in part, because this function of FANCC is abrogated.
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Pang Q, Wang C, Hu Y, Xu G, Zhang L, Hao X, Zhang Q, Gregerson H. Experimental study of the morphology of cerebral bridging vein. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 2001; 16:19-22. [PMID: 12899343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE To investigate the morphological properties of pig cerebral bridging vein. METHODS The morphology and fibre arrangement of 15 cerebral bridging veins obtained from 7 Danish Yorkshire landrace pigs were observed. RESULTS There was a narrow region at the junction of the cerebral bridging veins and superior sagittal sinus termed "outflow cuff segment". The diameter and length of outflow cuff segment were much smaller and the thickness was higher than those of the cerebral bridging veins ( P < 0.01), and circumferential collagen fibres were most dense in the outflow cuff segment. The opening angle of the outflow cuff segment and the cerebral bridging veins were 115 +/- 4 degrees and 120 +/- 4 degrees ( P > 0.05). CONCLUSIONS There were differences in fibre arrangement and morphological properties between the outflow cuff segment and the cerebral bridging vein, just like a resistance valve, the outflow cuff segment may play an important role in stabilizing cerebral venous outflow and regulating intracranial pressure.
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Pang Q, Lu X, Gregersen H, von Oettingen G, Astrup J. Biomechanical properties of porcine cerebral bridging veins with reference to the zero-stress state. J Vasc Res 2001; 38:83-90. [PMID: 11173998 DOI: 10.1159/000051033] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Passive mechanical and morphometric properties of porcine cerebral bridging veins were studied. Fifteen cerebral bridging veins were obtained from 7 pigs. The superior sagittal sinus, bridging veins and the meninges were excised and placed in aerated calcium-free Krebs solution. The outflow cuff segment is a narrow region at the junction of the cerebral bridging veins and superior sagittal sinus. The principal direction of collagen fibres was longitudinal in the bridging vein and circumferential in the cuff region. The diameter was smaller in the outflow cuff segment than in the cerebral bridging veins in the pressure range studied (0-23 mm Hg) whereas the thickness was highest in the outflow cuff segment (p < 0.01). The circumferential stress-strain analysis showed that the outflow cuff segment was extensible up to a strain of 0.25. At higher strains the outflow cuff segment was progressively stiffer than the cerebral bridging vein (p < 0.05). The longitudinal stress-strain relation for the cerebral bridging vein was shifted to the left compared to the outflow cuff segment (p < 0.05). When compared to the stress-strain properties in the circumferential direction, the outflow cuff segment was more extensible and the cerebral bridging vein stiffer in longitudinal direction (p < 0.05). The opening angle of the outflow cuff segment and the cerebral bridging vein was 115 +/- 4 and 120 +/- 4 (means +/- SE) without statistical difference between the two regions. In conclusion the difference in biomechanical properties between the outflow cuff segment and the cerebral bridging vein was associated to their difference in histology and fibre arrangement. This indicates that the function of the outflow cuff segment is to act as a flow-limiting resistance to the outflow from the cerebral circulation.
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Pang Q, Fagerlie S, Christianson TA, Keeble W, Faulkner G, Diaz J, Rathbun RK, Bagby GC. The Fanconi anemia protein FANCC binds to and facilitates the activation of STAT1 by gamma interferon and hematopoietic growth factors. Mol Cell Biol 2000; 20:4724-35. [PMID: 10848598 PMCID: PMC85895 DOI: 10.1128/mcb.20.13.4724-4735.2000] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/1999] [Accepted: 04/07/2000] [Indexed: 12/31/2022] Open
Abstract
Hematopoietic progenitor cells from Fanconi anemia (FA) group C (FA-C) patients display hypersensitivity to the apoptotic effects of gamma interferon (IFN-gamma) and constitutively express a variety of IFN-dependent genes. Paradoxically, however, STAT1 activation is suppressed in IFN-stimulated FA cells, an abnormality corrected by transduction of normal FANCC cDNA. We therefore sought to define the specific role of FANCC protein in signal transduction through receptors that activate STAT1. Expression and phosphorylation of IFN-gamma receptor alpha chain (IFN-gammaRalpha) and JAK1 and JAK2 tyrosine kinases were equivalent in both normal and FA-C cells. However, in coimmunoprecipitation experiments STAT1 did not dock at the IFN-gammaR of FA-C cells, an abnormality corrected by transduction of the FANCC gene. In addition, glutathione S-transferase fusion genes encoding normal FANCC but not a mutant FANCC bearing an inactivating point mutation (L554P) bound to STAT1 in lysates of IFN-gamma-stimulated B cells and IFN-, granulocyte-macrophage colony-stimulating factor- and stem cell factor-stimulated MO7e cells. Kinetic studies revealed that the initial binding of FANCC was to nonphosphorylated STAT1 but that subsequently the complex moved to the receptor docking site, at which point STAT1 became phosphorylated. The STAT1 phosphorylation defect in FA-C cells was functionally significant in that IFN induction of IFN response factor 1 was suppressed and STAT1-DNA complexes were not detected in nuclear extracts of FA-C cells. We also determined that the IFN-gamma hypersensitivity of FA-C hematopoietic progenitor cells does not derive from STAT1 activation defects because granulocyte-macrophage CFU and erythroid burst-forming units from STAT1(-/-) mice were resistant to IFN-gamma. However, BFU-E responses to SCF and erythropoietin were suppressed in STAT(-/-) mice. Consequently, because the FANCC protein is involved in the activation of STAT1 through receptors for at least three hematopoietic growth and survival factor molecules, we reason that FA-C hematopoietic cells are excessively apoptotic because of an imbalance between survival cues (owing to a failure of STAT1 activation in FA-C cells) and apoptotic and mitogenic inhibitory cues (constitutively activated in FA-C cells in a STAT1-independent fashion).
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Liu M, Chen Z, Pang Q, Liang C, Park CS. [Application of less-than-one-hour in situ hybridization to diagnosis of infectious agents]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2000; 31:269-71. [PMID: 12515158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Less-than-one-hour in situ hybridization manual method for immunocytochemical analyses of formalin-fixed, paraffin embedded tissue sections was used to detect infectious agents. The method employs capillary action to sequentially apply, incubate and remove liquid reagents from opposite pairs of glass microscope slides and allows for simultaneous immunocytochemical analyses. We used this method to detect EB virus in nasopharyngeal tissues and human papilloma virus in cervical tissues. This rapid and sensitive procedure represents a significant improvement for clinical immunocytochemical and research laboratories alike.
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Li Y, Guan C, Zhang H, Chen Z, Li T, Pang Q. [Pharmacokinetic analysis of lactosaminated human growth hormone and human growth hormone]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2000; 31:7-10. [PMID: 12501599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
This study was undertaken to explore and compare the pharmacokinetic features of lactosaminated human growth hormone(hGH-L) and human growth hormone (hGH). Radioimmunoassay (RIA) technique was used. After mice were intravenously injected with hGH-L, their blood and liver samples were collected and handled. The blood drug concentration and liver drug concentration were determined using RIA technique. Then the pharmacokinetic parameters were obtained by analysing the curves of blood drug concentration-time and liver drug concentration-time. hGH was determinated with the same methods. The results showed that the area under curve (AUC) of blood drug concentration-time curve of hGH-L was 32,686.90, the mean remain time (MRT) of hGH-L in blood was 21.37 minutes, but the AUC of blood drug concentration-time curve of hGH was 36,913.08 and the MRT of hGH in blood was 24.98 minutes. Therefore, in blood, the uptake of hGH-L was less than that of hGH, the removal of hGH-L was faster than the removal of hGH. In liver, for hGH-L, the half-time of distribution (t1/2 alpha) was 1.84 minutes, the half-time of removal(t1/2 beta) was 11.09 minutes, the AUC of liver drug concentration-time curve was 17,621.9; for hGH, the t1/2 alpha was 2.11 minutes, the t1/2 beta was 75.65 minutes, the AUC of liver drug concentration-time curve was 12,148.2. Therefore, in liver, the uptake of hGH-L was more than that of hGH, the distribution and removal of hGH-L were faster than those of hGH. Therefore, the pharmacokinetic features of hGH-L was better than the feature of hGH.
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Hays JB, Pang Q. Monitoring removal of cyclobutane pyrimidine dimers in Arabidopsis. Methods Mol Biol 1999; 113:175-81. [PMID: 10443420 DOI: 10.1385/1-59259-675-4:175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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Li Y, Guan C, Zhang H, Li L, Yang X, Chen C, Li T, Pang Q. [Comparative study on livertaxis of lactosaminated human growth hormone and galactosyl-human growth hormone]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1999; 30:138-41. [PMID: 12212040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
This study was conducted to compare the livertaxis of lactosaminated human growth hormone (hGH-L) with that of galactosyl human growth hormone (hGH-Gal), using radioactive tracer technique. hGH-L and hGH-Gal were first prepared. After hGH-L, hGH-Gal and hGH were labelled with 131I or 125I, the data on biodistribution in mice, imaging in rabbits and chicken were obtained. hGH-L and hGH-Gal had remarkable livertaxis and their percentages for uptake in liver were 68.83%-74.65% and 68.18%-74% respectively, which were about two times as high as that of hGH. All of the hepatic bindings were receptor-mediated. But, the synthesizing of hGH-L was more easy-to-do, more mild in reaction conditions, and more economical of raw material as compared with the synthesizing of hGH-Gal. Therefore, hGH-L is a more potential receptor-mediated hepatic targeting secreting somatomedian drug for treating dwarfism.
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80
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Pang Q, Mao B, Li B. [[symbol: see text]-shaped splitting of spinous process for lumbar spinostenosis]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 1998; 12:266-8. [PMID: 10437100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
In order to modify the plastic operation for lumbar spinostenosis, [symbol: see text]-shaped splitting of spinous process was designed. Fifty-six patients with lumbar spinostenosis were treated. There were 36 males and 16 females, age ranged from 32-67 years old (with an average of 48.9 years old). Among them, 8 patients operation on L2-L5 segments, 16 on L3-L5 segments and 22 patients on L4-L5 segments. After operation, 32 cases were followed up from 8 to 27 months. The results were: 1. The result of operation was excellent in 21 cases, good in 8 fair in 2 and poor in 1. The effective rate was 90.6%. 2. The rate of bony union from laminectomy was 95.1%. 3. The sagittal diameter and transverse diameter of the spinal canal were enlarged in an average of 6.4 mm and 3.2 mm, respectively, with a mean enlargement of 37.6%. The conclusion were that the plastic operation with [symbol: see text]-shaped splitting of spinous process for lumbar spinal canal was easy to handle and it could effectively prevent the lumbar instability and secondary stenosis following operation.
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81
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Pang Q, Prolla TA, Liskay RM. Functional domains of the Saccharomyces cerevisiae Mlh1p and Pms1p DNA mismatch repair proteins and their relevance to human hereditary nonpolyposis colorectal cancer-associated mutations. Mol Cell Biol 1997; 17:4465-73. [PMID: 9234704 PMCID: PMC232300 DOI: 10.1128/mcb.17.8.4465] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The MutL protein is an essential component of the Escherichia coli methyl-directed mismatch repair system but has no known enzymatic function. In the yeast Saccharomyces cerevisiae, the MutL equivalent, an Mlh1p and Pms1p heterodimer, interacts with Msh2p bound to mismatch-containing DNA. Little is known of the functional domains of Mlh1p and Pms1p. In this report, we define the Mlh1p and Pms1p domains required for Mlh1p-Pms1p interaction. The Mlh1p-interactive domain of Pms1p is comprised of 260 amino acids near the carboxyl terminus while the Pms1p-interactive domain of Mlh1p resides in the final 212 residues. The two domains are sufficient for Mlh1p-Pms1p interaction, as determined by the two-hybrid assay and by in vitro protein affinity chromatography. Deletions within the domains completely eliminated Mlh1p-Pms1p interaction. Using site-directed mutagenesis, we altered a number of highly conserved residues in the Mlh1p and Pms1p proteins, including some alterations that mimic germline mutations observed for human hereditary nonpolyposis colorectal cancer. Alterations either in the consensus MutL box located in the amino-terminal portion of each protein or in the carboxyl-terminal homology motif of Mlh1p eliminated DNA mismatch repair function but had no effect on Mlh1p-Pms1p interaction. In addition, certain MLH1 and PMS1 mutant alleles caused a dominant negative mutator effect when overexpressed. We discuss the implications of these findings for the structural organization of the Mlh1p and Pms1p proteins and the importance of Mlh1p-Pms1p interaction.
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Pang Q, Lo Y. [Experimental study on nerve growth factor in protecting injured spinal cord]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 1997; 11:3-5. [PMID: 9867940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Thirty-five SD rats were divided into 3 groups, in which 5 rats were served as control. The other 2 groups, 15 rats in each received either NGF solution or normal saline. The injury at the level of T8 spinal segment of the rat in these two groups were made by dropping a weight of 10 g from a height 2.5 cm after a total laminectomly from T7-11 segments. A thin plastic tube was inserted into the subarachnoid space below the injured segments. NGF was introduced through the tube at intervals of 1, 2, 3, 4, 8, 12, 24, 48 hours in the NGF group, and normal saline in the normal saline group. At 4, 8, 24 hours following surgery, 5 rats in each group were sacrificed and the injured segments were resected for examination. The contents of water and calcium were measured by dry-wet method and atomic absorption spectroscopy. The result showed that total calcium and water contents in normal saline group were markly increased, however, the changes of these two parametere were not so prominent in NGF group. It was suggested that NGF play a role in protecting the spinal cord by maintaining the calcium level of the injured segment.
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Li T, Pang Q, Jia Y, Wang P, Ma T, Meng J, Zhao S. [Determination of primaquine and hepatic targeting neoglycoalbumin-primaquine in whole blood and liver of mouse by normalphase high-performance liquid chromatography]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1995; 26:109-12. [PMID: 7657325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have developed a method to estimate primaquine (PQ) and hepatic targeting antimalarial agent neoglycoalbumin-primaquine (NGA PQ) in whole blood and liver of mice by sensitive and selective high-performance liquid chromatography. The primaquine was extracted out with ether from the basified biological samples in the PQ diphosphate group or from the samples which were acidic hydrolyzed then basified in NGA-PQ group. The extracts were evaporated under N2 then dissolved in the mobile phase. A linear chain analogue of primaquine was used as the internal standard. The samples were injected into the normal phase silica column with chloroform: methanol:ammonia solution (86.8:12.5:0.7,V/V/V) as mobile phase and detected at 254 nm. The average recovery of the method was 100.09 +/- 3.46 (mean +/- s)%; the CV of within-day and between-day were 2.7%-6.13% (n = 5) and 8.32%-13.56% (n = 9) respectively; in PQ group and NGA-PQ group, the PQ concentrations ranged from 10-20,000 ng/ml blood or 1g. liver respectively, and they all yielded a good linear relationship with the peak height ratios. No endogeneous interference was found in chromatograms of biological samples.
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Prolla TA, Pang Q, Alani E, Kolodner RD, Liskay RM. MLH1, PMS1, and MSH2 interactions during the initiation of DNA mismatch repair in yeast. Science 1994; 265:1091-3. [PMID: 8066446 DOI: 10.1126/science.8066446] [Citation(s) in RCA: 226] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The discovery that mutations in DNA mismatch repair genes can cause hereditary nonpolyposis colorectal cancer has stimulated interest in understanding the mechanism of DNA mismatch repair in eukaryotes. In the yeast Saccharomyces cerevisiae, DNA mismatch repair requires the MSH2, MLH1, and PMS1 proteins. Experiments revealed that the yeast MLH1 and PMS1 proteins physically associate, possibly forming a heterodimer, and that MLH1 and PMS1 act in concert to bind a MSH2-heteroduplex complex containing a G-T mismatch. Thus, MSH2, MLH1, and PMS1 are likely to form a ternary complex during the initiation of eukaryotic DNA mismatch repair.
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Pang Q, Hays JB, Rajagopal I, Schaefer TS. Selection of Arabidopsis cDNAs that partially correct phenotypes of Escherichia coli DNA-damage-sensitive mutants and analysis of two plant cDNAs that appear to express UV-specific dark repair activities. PLANT MOLECULAR BIOLOGY 1993; 22:411-426. [PMID: 8329681 DOI: 10.1007/bf00015972] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To resist terrestrial UV radiation, plants employ DNA-damage-repair/toleration (DRT) activities, as well as shielding mechanisms. Little is known about the structure and regulation of plant DRT genes. We isolated DRT cDNAs from Arabidopsis thaliana, by selecting for complementation of Escherichia coli mutants lacking all bacterial defenses against UV-light damage to DNA. These mutants are phenotypically deficient in recombinational and mutagenic toleration (RecA-), excision repair (Uvr-) and photoreactivation (Phr-). Among 840 survivors of heavily UV-irradiated (10(-7) survival) mutants harboring plasmids derived from an Arabidopsis cDNA library in the vector lambda YES, we identified four unique plant cDNAs, designated DRT100, DRT101, DRT102, and DRT103. Drt101 and Drt102 activity were specific for UV-light damage, and complemented both UvrB- and UvrC- phenotypes in the dark. Apparent Uvr- correction efficiencies were 1 to 40% for Drt101, and 0.2 to 15% for Drt102, depending on the UV fluence. Drt101 and Drt102 showed no extensive amino-acid homology with any known DNA-repair proteins. Drt100 appeared to correct RecA-, rather than Uvr-, phenotypes. Although the light dependence of Drt103 activity was consistent with its identification as a photoreactivating enzyme, its predicted amino-acid sequence did not resemble known photolyase sequences. The N-terminal coding sequence of Drt101 suggests that it is targeted to chloroplasts, as reported for Drt100. These cDNAs afforded only modest increases in survival during the original selection procedure. The fact that they were readily isolated nevertheless suggests that selections may be made powerful enough to overcome barriers to expression and function in bacteria, at least for cDNAs of reasonable abundance.
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Pang Q, Hays JB, Rajagopal I. Two cDNAs from the plant Arabidopsis thaliana that partially restore recombination proficiency and DNA-damage resistance to E. coli mutants lacking recombination-intermediate-resolution activities. Nucleic Acids Res 1993; 21:1647-53. [PMID: 8479917 PMCID: PMC309376 DOI: 10.1093/nar/21.7.1647] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Escherichia coli ruvC recG mutants lack RuvC endonuclease, which resolves crossed-strand joint molecules (Holliday junctions) formed during homologous recombination into recombinant products, and an activity (RecG) thought to partially replace RuvC. They are therefore highly deficient in homologous recombination, and sensitive to UV light and chemical DNA-damaging agents, presumably because of inability to tolerate unrepaired DNA damage by recombinational mechanisms (Lloyd, R.G. (1991) J. Bacteriol. 173:5414-5418). We transformed these mutants with plasmids expressing cDNAs from the plant Arabidopsis thaliana. Selection for bacteria with increased resistance to methylmethanesulfonate yielded two cDNAs, designated DRT111 and DRT112 (DNA-damage-repair/toleration). Expression of these plant cDNAs, especially DRT111, restored conjugal recombination proficiencies in ruvC and ruvC recG mutants to nearly wild-type levels. Both plant cDNAs significantly increased resistance of both mutants to UV light and several chemical DNA-damaging agents, but did not fully correct the mutant phenotypes. Drt111 activity, but not Drt112, also increased, to nearly wild-type levels, resistance of recG single mutants to UV plus mitomycin C. The predicted Drt111 and Drt112 polypeptides, 383 and 167 amino acids respectively, show no similarity with one another or with prokaryotic Holliday resolvases. Both appear chloroplast targeted; Drt112 is highly homologous to Arabidopsis plastocyanin. DRT111 and DRT112 probes hybridize only to DNA from closely related plants.
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87
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Pang Q, Hays JB, Rajagopal I. A plant cDNA that partially complements Escherichia coli recA mutations predicts a polypeptide not strongly homologous to RecA proteins. Proc Natl Acad Sci U S A 1992; 89:8073-7. [PMID: 1518832 PMCID: PMC49858 DOI: 10.1073/pnas.89.17.8073] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A plant (Arabidopsis thaliana) cDNA previously selected for its ability to partially complement the UV sensitivity of Escherichia coli RecA-UvrC-Phr- mutants and designated DRT100 (DNA-damage repair/toleration) was subcloned into a high-copy-number plasmid and expressed via a bacterial promotor. It increased resistance of RecA-UvrB-Phr- bacteria to mitomycin C and methyl methanesulfonate as well as to UV light. This lack of specificity, and its ability to increase resistance in both UvrB- and UvrC- mutants, suggested that Drt100 activity might be complementing RecA- phenotypes. DRT100 partially complemented three RecA- phenotypes thought to reflect deficiencies in homologous recombination--namely, inability to plate lambda red-gam- phages and P1 phages and to recombinationally integrate donor DNA during conjugal crosses--but did not complement inability to induce E. coli SOS functions. The 395-amino acid DRT100 open reading frame encodes an apparent N-terminal chloroplast transit peptide and a putative 322-residue mature protein with a conserved nucleotide binding motif, but otherwise little global homology with bacterial RecA proteins. There are several tandemly repeated leucine-rich motifs. DNA from two closely related plants, but not from maize, hybridized strongly to a DRT100 cDNA probe.
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Pang Q, Hays JB. UV-B-Inducible and Temperature-Sensitive Photoreactivation of Cyclobutane Pyrimidine Dimers in Arabidopsis thaliana. PLANT PHYSIOLOGY 1991; 95:536-43. [PMID: 16668017 PMCID: PMC1077565 DOI: 10.1104/pp.95.2.536] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Removal of cyclobutane pyrimidine dimers (CBPDs) in vivo from the DNA of UV-irradiated eight-leaf seedlings of Arabidopsis thaliana was rapid in the presence of visible light (half-life about 1 hour); removal of CBPDs in the dark, presumably via excision repair, was an order of magnitude slower. Extracts of plants contained significant photolyase in vitro, as assayed by restoration of transforming activity to UV-irradiated Escherichia coli plasmids; activity was maximal from four-leaf to 12-leaf stages. UV-B treatment of seedlings for 6 hours increased photolyase specific activity in extracts twofold. Arabidopsis photolyase was markedly temperature-sensitive, both in vitro (half-life at 30 degrees C about 12 minutes) and in vivo (half-life at 30 degrees C, 30 to 45 minutes). The wavelength dependency of the photoreactivation cross-section showed a broad peak at 375 to 400 nm, and is thus similar to that for maize pollen; it overlaps bacterial and yeast photolyase action spectra.
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Yuan M, Zhong Y, Pang Q, Li Z. [Synthesis of 4-[(4-chlorophenyl) (5-fluoro-2-hydroxyphenyl) methylene amino]butyrates and its anticonvulsant activity]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1990; 21:310-4. [PMID: 2093071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
It is known that gamma-aminobutyric acid (GABA) plays an important role in the pathophysiology of epilepsy. Under physiological conditions it is very difficult for GABA to cross the blood-brain barrier. It is likely that the esters of GABA, Which easily enter the brain, will have useful therapeutic properties. With this in mind, we have designed and synthesized 8 derivatives (IVa to IVh) of gamma-aminobutyric acid with an imine to link a lipophilic carrier in order to facilitate the passage of gamma-aminobutyric acid to cross the blood-brain barrier. All the eight synthesized title compounds were evaluated as anticonvulsants in mice via the Antiepileptic Drug Development Program of NIH. The compounds IVb and IVf showed anticonvulsant activity.
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