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Kruse Vestergaard E, Thostrup P, An T, Laegsgaard E, Stensgaard I, Hammer B, Besenbacher F. Comment on "High pressure adsorbate structures studied by scanning tunneling microscopy: CO on Pt(111) in equilibrium with the gas phase". PHYSICAL REVIEW LETTERS 2002; 88:259601. [PMID: 12097135 DOI: 10.1103/physrevlett.88.259601] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2002] [Indexed: 05/23/2023]
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Xiong Y, Tong M, An T, Karlsson HT. Aquabis(3,5-dimethyl-1H-pyrazole-kappaN2)(malonato-kappa2O,O')copper(II) dihydrate. Acta Crystallogr C 2001; 57:1385-7. [PMID: 11740090 DOI: 10.1107/s0108270101015116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2001] [Accepted: 09/14/2001] [Indexed: 11/10/2022] Open
Abstract
In the neutral title complex, [Cu(C3H2O4)(C5H8N2)2(H2O)]*2H2O or [Cu(mal)(dmp)2(H2O)]*2H2O (mal is malonate and dmp is 3,5-dimethyl-1H-pyrazole), the Cu(II) ion, in a slightly distorted square-pyramidal geometry, is coordinated by two O atoms of the bidentate malonate, the O atom of the water ligand and two N atoms from the two 3,5-dimethylpyrazole ligands. The mean Cu-N bond length is 2.007 (6) A, longer than the Cu-O(mal) bonds [1.950 (5) A]. The apical position is occupied by a relatively strongly coordinated water molecule [Cu-O(water) 2.288 (5) A]. The crystal structure is characterized by the layer motif of a hydrogen-bonded network.
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An T, Huang RQ, Yang Z, Zhang DK, Li GR, Yao YC, Gao J. Alkaloids from Cynanchum komarovii with inhibitory activity against the tobacco mosaic virus. PHYTOCHEMISTRY 2001; 58:1267-1269. [PMID: 11738420 DOI: 10.1016/s0031-9422(01)00382-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A pyrroloisoquinoline alkaloid, 2,3-dimethoxy-6-(3-oxo-butyl)-7,9,10,11,11a,12-hexahydrobenzo[f]pyrrolo[1,2-b]isoquinoline (1), whose structure was determined by spectroscopic methods, was isolated from the aerial parts of Cynanchum komarovii, together with two known alkaloids, 7-demethoxytylophorine (2) and 7-demethoxytylophorine N-oxide (3). Alkaloids 2 and 3 had antiviral activities against tobacco mosaic virus.
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Wu M, Liu X, Fang J, An T, Wang J. [Clinical and prognostic significance of serum CEA, NSE, CYFRA211, CA125 and CA199 levels in patients with advanced non-small cell lung cancer]. ZHONGGUO FEI AI ZA ZHI = CHINESE JOURNAL OF LUNG CANCER 2001; 4:357-9. [PMID: 21059317 DOI: 10.3779/j.issn.1009-3419.2001.05.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND To judge clinical and prognostic values of serum CEA, NSE, CYFRA211, CA125 and CA199 levels in patients with advanced non-small cell lung cancer ( NSCLC) . METHODS Ninety-five untreated but confirmed by histology or cytology patients with advanced NSCLC were studied. The serum levels of CEA, NSE, CYFRA211, CA125 and CA199 were detected before and after treatment by cisplatin-based regimens. RESULTS The positive rate was 53. 7%, 70. 5%, 62. 2%, 54. 1% and 31. 6% for CEA, NSE, CYFRA211, CA125, CA199 respectively, before treatment. The significant decreases of the markers were observed in 39 partial response patients ( P= 0. 030, 0. 000, 0. 009, 0. 002, 0. 034 respectively) . The overall 1- and 2-year survival rate were 52. 7%( 50/ 95) and 14. 7%( 14/ 95) respectively. Cox proportional hazard multivariate analysis showed that the prognosis of advanced NSCLC patients was related to response rate of first cycle, staging, performance status and serum CYFAR211 level before treatment, but not to histology and serum levels of CEA, NSE, CA125 and CA199 before treatment. CONCLUSIONS The decrease in CEA, NSE, CYFRA211, CA125, and CA199 levels could be used to evaluate the chemotherapeutic response. TNM stage and performance status and CYFRA211 before treatment can be used as prognostic parameters in patients with advanced NSCLC.
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An T, Zhu X, Xiong Y. Synergic degradation of reactive brilliant red X-3B using three dimension electrode-photocatalytic reactor. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2001; 36:2069-2082. [PMID: 11759916 DOI: 10.1081/ese-100107449] [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
A new reactor, three dimension electrode-photocatalytic reactor, was designed and used to investigate the photoelectrochemical degradation of reactive brilliant red X-3B (RBRX) in simulated wastewater. The reactor was characterized by a series of parameters, the current change, decolorization ratio, COD removal and degradation ratio. It was found that the three dimensional electrode-photocatalytic reactor could effectively destroy the RBRX within a reaction time of 30 min. The results also showed that the photoelectrochemical process is more efficient than the single application of electrochemical oxidation or photocatalytic degradation. The degradation reactions of RBRX conformed to pseudo first order kinetics in the three processes, and an apparent synergic effect in the increase of the photocurrent and the disappearance of RBRX was observed by combining the electrochemistry with photocatalytic process in the three dimension electrode-photocatalytic reactor.
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Cao W, Wu T, An T, Li L. [Study on the mortality of injury in Chinese population in urban and rural areas from 1990 to 1997]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2000; 21:327-9. [PMID: 11860806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To describe the characteristics and trend of injuries among urban and rural Chinese population. METHODS Data from annual Chinese national health statistics (1990 - 1997) were analyzed. RESULTS The overall mortality of injury in China increased from 36.8/10(6) to 76.7/10(6) from 1990 to 1997. Injury was the forth leading causes of death in urban areas and the fifth in rural areas. The death rate of injury declined in the urban while increasing in the rural areas. The rural death rate of injury was about two times of that in urban and the difference was increasing over time. The death rate of men was higher than that of women and the ratio was 1.3 - 1.9. Children below 4 years old and people above 60 years old showed the highest rates. The first three leading causes of death of injuries in urban areas were traffic accident, suicide and fall, while in rural areas were suicide, traffic accident and drowning. The death rate caused by suicide was 6.5/10(6) - 27.1/10(6) and the rate in rural areas was 2.7 to 4.0 times of that in urban areas. The mortality of suicide declined in urban while increased in rural areas. The mortality of traffic accidents had a tendency of increase in both urban and rural areas. CONCLUSION Injury has been one of the leading cause of death but without effectively control programs for population in Urban and Rural areas in China, special in rural areas.
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Jimenez RE, Tiguert R, Hurley P, An T, Grignon DJ, Lawrence D, Triest J. Unilateral hydronephrosis resulting from intraluminal obstruction of the ureter by adenosquamous endometrioid carcinoma arising from disseminated endometriosis. Urology 2000; 56:331. [PMID: 10925117 DOI: 10.1016/s0090-4295(00)00580-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A case of adenosquamous carcinoma arising in the background of disseminated pelvic endometriosis presented as unilateral hydronephrosis and a polypoid intraluminal ureteral mass. This is the first case of a malignancy arising in endometriosis presenting as an obstructive ureteral mass. The patient had a history of total hysterectomy and bilateral salpingo-oophorectomy 5 years earlier because of an endometriotic cyst, and had since been under unopposed estrogen replacement therapy. An analysis of the case and related literature is presented. Possible pathogenic mechanisms are discussed.
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Yu S, Pu P, Jiang D, An T, Guan X, Yang L. [Relationship of bcl-2 gene expression with cell proliferation and apoptosis in human gliomas]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 2000; 29:12-5. [PMID: 11866884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the relationship of bcl-2 gene expression level in human gliomas with the malignant degree, cell proliferative activity and apoptosis of the tumors. METHODS The expression of bcl-2 mRNA, bcl-2 protein and proliferating cell antigen, and the apoptosis in sixty-nine human glioma specimens with different malignant grades were studied using in situ hybridization, in situ cell death detection (TUNEL method) and immunohistochemistry. RESULTS Of the 69 gliomas, 64 (92.8%) and 60 (87.0%) expressed bcl-2 mRNA and bcl-2 protein, respectively. The expression levels of bcl-2 mRNA and bcl-2 protein were correlated positively with each other (r(s) = 0.999, P < 0.01). The expression levels of bcl-2 mRNA and bcl-2 protein were both higher in WHO grade IV gliomas than in grade III gliomas, and the expression was lowest in grade I-II gliomas (P < 0.02 approximately 0.001). With the increase in the expression of bcl-2 protein, the cell proliferating activity increased and apoptosis decreased in the tumor cells. There was significant difference of cell proliferation and apoptosis between + + + group and + + group of bcl-2 protein expression (P < 0.05) as well as between both the former groups, and the negative and + group (P < 0.01) respectively. CONCLUSIONS Over-expression of bcl-2 gene inhibits apoptosis of glioma cells, and the inhibitory intensity increases with the ascending of bcl-2 gene expression level in glioma cells. Both the decrease in apoptosis caused by bcl-2 gene over-expression and the excessive cell proliferation promoted by other gene abnormalities may result in unlimited cell accumulation, which may play an important role in the development and malignant progression of gliomas.
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Sugawa C, Takekuma Y, Lucas CE, Amamoto H, An T, Sanchez EQ. Experimental studies of thermal therapy for severe nonvariceal bleeding in dogs. Surg Endosc 1999; 13:1203-7. [PMID: 10594266 DOI: 10.1007/pl00009621] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND There are several methods of achieving endoscopic hemostasis for nonvariceal hemorrhage, including use of a heater probe, bipolar electrocoagulation, use of a Gold probe, and injection therapy with epinephrine or ethyl alcohol. However, due to clinical variations, clinical studies comparing thermal with injection therapy have yielded conflicting results. Therefore, we used a canine model of acute bleeding from gastric serosal vessels to examine the efficacy of the heater probe and the Gold probe in achieving hemostasis and to compare the injurious effects of these methods with injection therapy. METHODS Seven mongrel dogs were used in the study. Four were assigned to acute experiments in which transected blood vessels were allowed to bleed profusely. Two dogs of this group were treated with either a large or small Gold probe, while the other two were treated with either a large or small heater probe. In the other three dogs, we tested the chronic effects of the heater probe, the Gold probe, and injection therapy with dilute epinephrine. RESULTS Complete hemostasis was achieved for all four dogs in the acute experiments. Dogs treated with either a large or small heater probe had coagulation necrosis that extended to the serosa and muscularis but not to the mucosa. The large Gold probe had similar results, but the small Gold probe caused tissue damage to the serosa, muscularis, submucosa, and mucosa at several of the application sites. Both probes caused scarring of the gastric wall. In the chronic experiments, we found that the Gold probe caused larger mucosal ulcers than the heater probe. All ulcers healed in 3 weeks. The epinephrine injection caused localized swelling and discoloration, but after 1 week the tissue returned to normal. CONCLUSIONS Both the heater probe and the Gold probe are effective in achieving hemostasis in a canine model of nonvariceal hemorrhage, and both methods are superior to injection therapy. For active bleeding ulcers, we currently recommend a combination therapy, using first injection therapy and then a heater or Gold probe. However, clinicians should be aware of the potential for tissue damage.
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Abstract
After treatment with etoposide, two patients with lung cancer developed interstitial infiltrates and respiratory failure. Of the two, one patient responded rapidly to steroid therapy and developed recurrent symptoms on re-challenge with etoposide. Both patients had histopathologic findings consistent with drug-induced pulmonary toxicity. Etoposide-induced lung disease needs to be considered in patients who develop subacute dyspnea and interstitial infiltrates during treatment with this agent.
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Zhou Z, Zwelling LA, Kawakami Y, An T, Kobayashi K, Herzog C, Kleinerman ES. Adenovirus-mediated human topoisomerase IIalpha gene transfer increases the sensitivity of etoposide-resistant human breast cancer cells. Cancer Res 1999; 59:4618-24. [PMID: 10493516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Cellular resistance to chemotherapeutic agents is attributable to several mechanisms, including alteration of topoisomerase IIalpha (topo IIalpha) gene expression. Etoposide-resistant MDA-VP human breast cancer cells express lower amounts of enzymatically active and drug-sensitive topo IIalpha than do MDA parent cells, suggesting that the low level of topo IIalpha is the mechanism of resistance. To determine whether transfer of a normal topo IIalpha gene into MDA-VP cells can increase topo IIalpha gene expression, topo IIalpha protein production, and cell sensitivity to etoposide, a recombinant adenovirus, Ad-hTopoIIalpha, containing the human topo IIalpha gene, was constructed. The shuttle vector pAvCvSv-hTopIIalpha was constructed and co-transfected with the pBHG10 packaging vector into 293 cells. Infectious recombinant adenovirus plaques were isolated and purified. Presence of the topo IIalpha gene was confirmed by PCR and restriction enzyme digestion. After infection with Ad-hTopoIIalpha, topo IIalpha mRNA expression in MDA-VP cells increased 7.4-fold, topo IIalpha protein production increased 5.9-fold, and sensitivity to etoposide was enhanced 4.5-fold compared with control transfected cells. Infection of normal human embryonic lung cells and human fibroblast cells with Ad-hTopoIIalpha did not enhance the expression of topo IIalpha or sensitivity to etoposide. Viral uptake was comparable in the MDA-VP and normal cell lines. These data suggest that topo IIalpha gene transfer using an adenoviral vector can selectively increase etoposide sensitivity in drug-resistant tumor cells and may enhance the therapeutic index of etoposide.
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Worth LL, Jia SF, An T, Kleinerman ES. ImmTher, a lipophilic disaccharide derivative of muramyl dipeptide, up-regulates specific monocyte cytokine genes and activates monocyte-mediated tumoricidal activity. Cancer Immunol Immunother 1999; 48:312-20. [PMID: 10473806 PMCID: PMC11037117 DOI: 10.1007/s002620050580] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
ImmTher, a liposome-encapsulated lipophilic disaccharide tripeptide derivative of muramyl dipeptide, previously showed activity against liver and lung colorectal metastases in a phase I trial. The purpose of the current studies was to investigate whether ImmTher could up-regulate specific cytokine gene expression and protein production, as well as activate the tumoricidal or cytostatic activity of human monocytes. ImmTher induced the expression and production of interleukin(IL)-1alpha IL-1beta, IL-6, IL-8, IL-12, macrophage chemotactic and activating factor, and tumor necrosis factor alpha but not IL-2 or IL-10. Cytostatic or cytotoxic monocyte activity was stimulated against human Ewing's sarcoma, osteosarcoma, and melanoma cells but not breast cancer cells. Production and secretion of these cytokine proteins may play a role in the antitumor activity of ImmTher.
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Yu S, Pu P, Jiang D, Cheng Y, An T, Guan X. [Observations on expression of c-fos and c-myc genes and activity of PDGFBB autocrine loop in 67 human gliomas]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 1999; 28:182-6. [PMID: 11869525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the variance of expression of c-fos and c-myc genes and the activity of platelet-derived growth factor (PDGF) BB autocrine loop in human gliomas as well as their relationship. METHODS In situ hybridization and immunohistochemistry were used to study 67 human glioma specimens of different grades. RESULTS The incidences, of positive expression for c-fos mRNA, c-fos protein, c-myc mRNA and c-myc protein were 100% (67/67), 100% (67/67), 85.1% (57/67) and 83.6% (56/67) respectively. There was significant positive correlation between the positive cell densities of c-fos mRNA (92.49 +/- 33.87) and c-fos protein (91.64 +/- 38.11), and of c-myc mRNA (72.70 +/- 40.56) and c-myc protein (71.49 +/- 41.11, r = 0.917 - 0.988, P < 0.001). All of them also increased correspondingly with the malignant degree of the tumors and level of PDGFB mRNA expression in the tumor cells (P < 0.05 - 0.01). Not only were the positive cell densities of PDGF alpha receptor (58.46 +/- 28.77), PDGF beta receptor (63.03 +/- 31.63) and phosphotyrosine protein (68.25 +/- 29.30) correlated positively with one another (r = 0.827 - 0.896, P < 0.001), but they also all correlated positively with the positive cell densities of PDGFB mRNA, c-fos mRNA, c-fos protein, c-myc mRNA and c-myc protein respectively (r = 0.615 - 0.888, P < 0.001). CONCLUSIONS The abnormally increased activity of the PDGFBB autocrine loop possibly upregulated the overexpression of c-fos and c-myc genes in glioma cells and suggested that c-fos and c-myc proteins probably played an important role as downstream response factors in the signaling pathway in which PDGFBB could induce gliocyte transformation and glioma development.
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Jia SF, An T, Worth L, Kleinerman ES. Interferon-alpha enhances the sensitivity of human osteosarcoma cells to etoposide. J Interferon Cytokine Res 1999; 19:617-24. [PMID: 10433362 DOI: 10.1089/107999099313758] [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: 11/13/2022] Open
Abstract
The purpose of these studies was to determine whether interferon-alpha (IFN-alpha) could enhance the sensitivity of human osteosarcoma cells to the cytotoxic actions of etoposide (VP-16). Cytostasis was determined using a [3H]thymidine incorporation assay, whereas cytotoxicity was quantified by a colony-formation assay. Low concentrations (0.1-5 U/ml) of IFN-alpha enhanced the cytostatic activity of VP-16 against MG-63, SAOS-2, and TE-85 osteosarcoma cells. The cytostatic activity of 1 microM VP-16 rose from 11% to 64%, 9% to 31%, and 10% to 71%, respectively, in the three cell lines when IFN-alpha was present. Survival fraction was also decreased when the osteosarcoma cells were treated with VP-16 + IFN-alpha as compared to either agent alone. The interaction between these two agents was determined to be synergistic rather than additive by interaction index analysis. Similar effects on cytostasis and cytotoxicity were observed when IFN-alpha was combined with Adriamycin but not cisplatin, actinomycin D, vinblastine, or amsacrine. VP-16 uptake was enhanced 12-fold in the presence of IFN-alpha, but this did not appear to translate into an increase in topoisomerase-II (topo-II)-DNA complex formation as quantified by the sodium dodecyl sulfate-KCl precipitation assay. We also could not detect alterations in topo-II expression, topo-II protein production, or cell cycle kinetics that have been shown to correlate with increased VP-16 cell sensitivity. Therefore, at this time the mechanism of enhanced cell sensitivity to the combination treatment remains unclear.
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An T, Ma C, Li J. [High tibial osteotomy combined with autogenous periosteal graft for osteoarthritis of knee]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 1998; 12:226-8. [PMID: 10437074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
The osteoarthritis of knee is a common disorder but no always to be treated satisfactorily. Between 1988 and 1992, the method, a high tibial osteotomy to correct the genu varum combined with autogenous periosteal or perichondrial graft to deal with the chondromalacia patella was used. Thirty-two patients (51 knees) were treated by this method and the patients were followed up for an average of 5.1 years. The excellent and good results were obtained in 90.2%. This method was obviously better than any other simple high tibial osteotomy. Therefore, this method was considered to be effective for treatment of osteoarthritis of knee with varum deformity and chondromalcia patella.
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Li L, Yiannopoulou A, Urbanski K, Lyyra AM, Ji B, Stwalley WC, An T. Erratum: Hyperfine structures of the 7Li2, b 3Πu, 2 3Πg, and 3 3Πg states: Continuous wave perturbation facilitated optical–optical double resonance spectroscopy [J. Chem. Phys. 105, 6192 (1996)]. J Chem Phys 1997. [DOI: 10.1063/1.474130] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Li L, Yiannopoulou A, Urbanski K, Lyyra AM, Ji B, Stwalley WC, An T. Hyperfine structures of the 7Li2 b3Πu, 23Πg, and 33Πg states: Continuous wave perturbation facilitated optical–optical double resonance spectroscopy. J Chem Phys 1996. [DOI: 10.1063/1.473003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Asano T, An T, Mayes J, Zwelling LA, Kleinerman ES. Transfection of human topoisomerase II alpha into etoposide-resistant cells: transient increase in sensitivity followed by down-regulation of the endogenous gene. Biochem J 1996; 319 ( Pt 1):307-13. [PMID: 8870683 PMCID: PMC1217769 DOI: 10.1042/bj3190307] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have investigated the possibility of overcoming the resistance of human brain tumour cells (HBT20) to etoposide by transferring the normal human topoisomerase II alpha (H-topo II) gene into these cells. H-topo II in a mammalian expression vector containing a glucocorticoid-inducible mouse mammary tumour virus (MMTV) promoter was transfected into etoposide-resistant HBT20 cells (HBT20-hTOP2MAM). HBT20 cells transfected with pMAMneo vector alone served as control cells (HBT20-MAM). These were stable transfections. Following a 2 h dexamethasone treatment, H-topo II mRNA expression, protein production, etoposide-induced DNA-protein complex formation and sensitivity to etoposide were increased in HBT20-hTOP2MAM cells compared with control HBT20-MAM cells and with HBT20-hTOP2MAM cells not treated with dexamethasone. However, mRNA and protein levels and cell sensitivity returned to baseline when incubation with dexamethasone was continued for 24 h. This decrease from the 2 h values could not be explained by a loss of the MMTV promoter response to dexamethasone. (H-topo II alpha promoter)-(chloramphenicol acetyltransferase) constructs containing regions -559-0 and -2400-0 were significantly down-regulated in HBT20-hTOP2MAM cells treated for 24 h with dexamethasone compared with dexamethasone-treated control cells. H-topo II mRNA stability after 24 h of dexamethasone treatment was not altered compared with that in control cells. Our data indicate that the exogenously produced H-topo II may have a negative-feedback effect on the endogenous topoisomerase II promoter, causing down-regulation of the endogenous gene.
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MESH Headings
- Animals
- Antigens, Neoplasm
- Antineoplastic Agents, Phytogenic/pharmacology
- Blotting, Northern
- Brain Neoplasms/drug therapy
- Brain Neoplasms/enzymology
- Brain Neoplasms/genetics
- DNA/metabolism
- DNA Topoisomerases, Type II/genetics
- DNA-Binding Proteins
- Dexamethasone/pharmacology
- Down-Regulation
- Drug Resistance, Neoplasm
- Etoposide/pharmacology
- Gene Expression Regulation, Enzymologic
- Humans
- Isoenzymes/genetics
- Mice
- Plasmids/metabolism
- Promoter Regions, Genetic
- RNA, Messenger/metabolism
- Restriction Mapping
- Transcription, Genetic/drug effects
- Transfection
- Tumor Cells, Cultured
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Asano T, An T, Jia SF, Kleinerman ES. Altered monocyte chemotactic and activating factor gene expression in human glioblastoma cell lines increased their susceptibility to cytotoxicity. J Leukoc Biol 1996; 59:916-24. [PMID: 8691078 DOI: 10.1002/jlb.59.6.916] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A cDNA encoding for human monocyte chemotactic and activating factor (MCAF) was ligated into the retroviral vector pLXSN. These pMCAF-LXSN and antisense p-antiMCAF-LXSN vectors were transfected into HBT20 and HBT28 human brain tumor cells. HBT28 cells constitutively express high amounts of MCAF, whereas HBT20 cells express much less MCAF. HBT20 cells transfected with pMCAF-LXSN (HBT20-MCAF) showed significantly higher MCAF mRNA expression and MCAF protein production than the HBT20-parent or HBT20 cells transfected with control vector (HBT20-LXSN). In contrast, supernatant from HBT28 cells transfected with p-antiMCAF-LXSN (HBT28-antiMCAF) contained less MCAF than HBT28-parent, HBT28-LXSN, and HBT28-MCAF cells. Activated human monocytes killed HBT20-MCAF cells more efficiently compared with HBT20-parent, HBT20-LXSN, and HBT20-antiMCAF cells (P< 0.02), whereas HBT28-antiMCAF cells were killed more efficiently by activated monocytes compared with HBT28-parent, HBT28-LXSN, and HBT28-MCAF cells (P< 0.05). Cultured supernatants from activated monocytes plus HBT20-MCAF cells or from activated monocytes plus HBT28-antiMCAF cells inhibited the growth of HBT20 and HBT28 cells, respectively. Altered MCAF expression can therefore enhance the ability of activated monocytes to kill brain tumor cells. This increased cytotoxicity is partially dependent upon the basal state of MCAF in the individual tumor cells.
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Asano T, Zwelling LA, An T, McWatters A, Herzog CE, Mayes J, Loughlin SM, Kleinerman ES. Effect of transfection of a Drosophila topoisomerase II gene into a human brain tumour cell line intrinsically resistant to etoposide. Br J Cancer 1996; 73:1373-80. [PMID: 8645582 PMCID: PMC2074495 DOI: 10.1038/bjc.1996.261] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The human brain tumour cell line HBT20 is intrinsically resistant to etoposide and does not express mdr-1 mRNA. These studies were conducted to determine whether transfecting a Drosophila (D) topoisomerase II (topo II) gene into HBT20 cells could increase their sensitivity to etoposide. A D-topo II construct in a pMAMneo vector under the control of a mouse mammary tumour virus (MMTV) promoter was transfected into HBT20 cells. The gene is inducible by dexamethasone (Dex). The growth rate of the transfected cells and percentage of the cells in G1, S and G2M was no different than the parental cells. Survival after etoposide exposure (10 microM x 2 h) was measured by colony formation. Parental cells and cells transfected by pMAMneo vector alone showed no enhanced etoposide sensitivity after 24 h of Dex stimulation. By contrast, D-topo II transfected cells were sensitised 3-fold when etoposide treatment was preceded by 24 h Dex stimulation. Northern blotting and Western blotting confirmed that Dex had induced D-topo II expression in the sensitised cells. However, in D-topo II-transfected cells increasing the duration of Dex stimulation to 48 h eliminated the sensitisation to etoposide although increased MMTV promoter activity and expression of the D-topo II gene persisted. Measurement of endogenous human topo-II mRNA and protein revealed a decrease after Dex exposure of greater than 24 h. At these distal times, the total cellular topo II levels (endogenous + exogenous) may be decreased, which may explain why increased sensitivity to etoposide could no longer be demonstrated. This model suggests that D-topo II gene transfection can sensitise de novo resistant HBT20 cells to etoposide but that the time frame of that sensitisation is limited.
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Yiannopoulou A, Urbanski K, Antonova S, Lyyra AM, Li L, An T, Whang TJ, Ji B, Wang XT, Stwalley WC, Leininger T, Jeung G. The 2 3Πg and 3 3Πg states of 7Li2: Optical–optical double resonance spectroscopy and ab initio calculations. J Chem Phys 1995. [DOI: 10.1063/1.470469] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Fernandez-Madrid F, Karvonen RL, Teitge RA, Miller PR, An T, Negendank WG. Synovial thickening detected by MR imaging in osteoarthritis of the knee confirmed by biopsy as synovitis. Magn Reson Imaging 1995; 13:177-83. [PMID: 7739358 DOI: 10.1016/0730-725x(94)00119-n] [Citation(s) in RCA: 160] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Previous studies have established the value of magnetic resonance imaging (MRI) in detecting articular changes characteristic of osteoarthritis (OA) of the knee. We have observed some MRI features in OA of the knee presumably indicating synovial thickening. To determine whether these MR features represent chronic synovial inflammation, we studied the knees of nine patients at the mild end of the spectrum of OA of relatively short duration (89%: < or = 4 yr), who were selected because MRI showed anatomical abnormalities compatible with synovial thickening. The painful knee was examined using conventional and weight-bearing radiographs, MRI, and arthroscopy. MR images suggestive of synovial thickening typically appeared in or near the intercondylar region of the knee, in the infrapatellar fat pad, or in the posterior joint margin. The site of an arthroscopic biopsy of the synovial membrane was guided by MRI to the area thought to represent synovial thickening for each patient knee. Pathological examination of these synovial membrane biopsies showed a mild chronic synovitis, and thus a correspondence with the synovial thickening detected by MRI. Our results suggest that MRI can be used to evaluate the extent of synovitis, observed as synovial thickening, in patients with early OA of the knee.
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Asano T, McWatters A, An T, Matsushima K, Kleinerman ES. Liposomal muramyl tripeptide up-regulates interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor-alpha, interleukin-6 and interleukin-8 gene expression in human monocytes. J Pharmacol Exp Ther 1994; 268:1032-9. [PMID: 8113959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) is a new biologic agent presently in clinical trials for metastatic osteosarcoma and melanoma. The mechanism of L-MTP-PE antitumor activity is linked to its activation of monocyte tumoricidal function. The purpose of this study was to determine whether L-MTP-PE affected the expression of cytokine genes in monocytes. Monocyte interleukin (IL)-1 alpha, IL-1 beta, IL-6, IL-8 and tumor necrosis factor (TNF)-alpha expression were all up-regulated after a 2-h incubation with L-MTP-PE. The increased expression of IL-1 alpha, IL-1 beta, IL-6 and IL-8 persisted up to 72 h. Increased TNF-alpha expression declined by 24 h. The kinetics of cytokine expression stimulated by L-MTP-PE were different from those seen after lipopolysaccharide (LPS) stimulation. Lipopolysaccharide stimulation caused a rapid increase in cytokine expression followed by a rapid decline. L-MTP-PE did not affect the expression of these cytokines in lymphocytes, nor did L-MTP-PE upregulate IL-2 expression in lymphocytes. The early up-regulation of all five cytokines was due to an increase in the transcriptional activity. Modification of mRNA stability was not detected at 2 h but was seen after a 24-h exposure to L-MTP-PE. The subsequent production and secretion of these cytokine proteins may play a role in L-MTP-PE antitumor activity.
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Asano T, Fujimaki W, McWatters A, An T, Matsushima K, Kleinerman ES. Effect of Adriamycin on liposomal muramyl tripeptide's ability to up-regulate monocyte cytokine expression. Cancer Immunol Immunother 1993; 37:408-11. [PMID: 8242665 PMCID: PMC11038091 DOI: 10.1007/bf01526798] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/1993] [Accepted: 09/03/1993] [Indexed: 01/29/2023]
Abstract
Liposomal muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) is a biological agent in phase I and II trials for osteosarcoma and melanoma. Its mechanism of action has been linked to its ability to activate monocyte tumoricidal function and to stimulate monocyte production of tumor necrosis factor (TNF) and interleukins(IL)-1, -6, and -8. Our ultimate goal is to combine L-MTP-PE with chemotherapy. The purpose of this study was to determine whether doxorubicin (Adriamycin) interfered with the ability of L-MTP-PE to activate monocyte cytokine production. Human monocytes were cultured with or without 5-500 ng/ml of Adriamycin for 3 h and washed before being exposed to 2 micrograms/ml L-MTP-PE for 16 h. Cultured supernatants were collected and assayed for TNF, IL-1, IL-6, and IL-8. The messenger RNA expression of IL-1 alpha, IL-1 beta, TNF alpha, IL-6, and IL-8 was quantified with northern blot analysis. Adriamycin did not suppress the up-regulation of any of these cytokines. We concluded that combination therapy with L-MTP-PE and Adriamycin is feasible and that this combination warrants further investigation in a clinical setting.
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Fujimaki W, Itoh K, An T, Gano JB, Ross MI, Mansfield PF, Balch CM, Augustus LB, Karkevitch DD, Johnston D. Cytokine production and immune cell activation in melanoma patients treated with liposomal muramyl tripeptide (CGP 19835A lipid). CANCER BIOTHERAPY 1993; 8:307-18. [PMID: 7804372 DOI: 10.1089/cbr.1993.8.307] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We conducted a pilot study using liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) preoperatively in patients with stage III or IV resectable melanoma who were at high risk for recurrence. Patients received L-MTP-PE for 1 month before surgery and then 5 months postoperatively. Several immune parameters were monitored during preoperative therapy to search for correlations with clinical (tumor) response. The 18 patients were classified into three groups according to their responses and disease-free intervals: no evidence of disease (NED) at week 24 of therapy, relapse during therapy and progressive disease on therapy noted at the time of surgery. Six of nine patients in the NED group demonstrated increased monocyte tumoricidal activity (MTA) during week 1 of therapy. MTA increased in three of the six patients in the relapse group. MTA did not increase in the three patients who had progressive disease on therapy. Plasma neopterin levels were elevated by 72 h following the first L-MTP-PE dose in all 18 patients. Circulating levels of tumor necrosis factor were elevated in 15 of 16 patients tested, and IL-6 levels were elevated in all 18 patients. Melanoma cells from all three patients with progressive disease at the time of surgery proliferated well in vitro, whereas tumor cells from 10 of the 15 patients in the other two groups did not proliferate. There were no discernible differences among the three groups in the magnitude of IL-2-induced proliferation of tumor infiltrating lymphocytes. However, IL-2-activated TILs from the NED group exhibited cytotoxicity against autologous tumor cells in vitro. In summary, whereas L-MTP-PE stimulated several immunologic responses in all patients, the only two parameters that correlated with clinical status were MTA and the tumor proliferation assay. These two biologic assays could serve to distinguish potential responders from nonresponders early in the course of treatment.
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