Shawn J. Green
Publications
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34.48Impact points
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4.29Impact points
Regarding the potential perils of phytosterols.
Atherosclerosis. 06/2007; 192(1):227-9; author reply 230.
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7.54Impact points
Tissue factor/factor VIIa inhibitors block angiogenesis and tumor growth through a nonhemostatic mechanism.
Cancer research. 07/2003; 63(11):2997-3000.
An association between cancer and thrombosis has been recognized for more than a century. However, the manner by which tumor growth is regulated by coagulation in vivo remains unclear. To assess the role of coagulation on tumor growth, in vivo, we tested coagulation inhibitors specific for either ti... [more] An association between cancer and thrombosis has been recognized for more than a century. However, the manner by which tumor growth is regulated by coagulation in vivo remains unclear. To assess the role of coagulation on tumor growth, in vivo, we tested coagulation inhibitors specific for either tissue factor (TF)/factor VIIa (fVIIa) complexes or factor Xa (fXa) for antitumor activity. Here, we show that two inhibitors of TF/fVIIa, TF pathway inhibitor (TFPI) and the nematode anticoagulant protein rNAPc2, inhibit both primary and metastatic tumor growth in mice. In addition, we show that rNAPc2 is also a potent inhibitor of angiogenesis. In contrast, rNAP5, a second nematode anticoagulant protein that specifically inhibits fXa, does not exhibit antitumor activity. Because the hemostatic activity of TF/fVIIa is mediated through activation of fXa, these data suggest that proteolytic activity of TF/fVIIa promotes tumor growth and angiogenesis through a novel proangiogenic mechanism and independently of hemostasis.
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4.75Impact points
Dose-response effects of 2-methoxyestradiol on estrogen target tissues in the ovariectomized rat.
Endocrinology. 04/2003; 144(3):785-92.
In three experiments, we evaluated the pharmacological effects of 2-methoxyestradiol (2ME(2)) on several estrogen target tissues. Experiment 1: we gavaged recently ovariectomized (OVX) 9.5-wk-old rats with 2ME(2) at doses of 0, 0.1, 1, 4, 20, and 75 mg/kg in a 21-d dose-response study. 2ME(2) reduce... [more] In three experiments, we evaluated the pharmacological effects of 2-methoxyestradiol (2ME(2)) on several estrogen target tissues. Experiment 1: we gavaged recently ovariectomized (OVX) 9.5-wk-old rats with 2ME(2) at doses of 0, 0.1, 1, 4, 20, and 75 mg/kg in a 21-d dose-response study. 2ME(2) reduced body weight and serum cholesterol, increased uterine weight and epithelial cell height, and inhibited longitudinal and radial bone growth compared with values in the untreated OVX rat. All doses of 2ME(2) maintained cancellous bone mass at the baseline level, the lowest effective dose being 20-fold less than a uterotrophic dose. Experiment 2: in an 8-wk experiment in adult OVX rats, a nonuterotrophic dose of 2ME(2) (4 mg/kg x d) suppressed body weight gain, inhibited bone formation in cancellous bone and partially prevented bone loss in the tibial metaphysis. Experiment 3: in weanling rats, ICI 182,780 did not antagonize the effect of 2ME(2). We conclude that 2ME(2) antagonizes the skeletal changes that follow OVX at doses that have minimal or no effects in the uterus in both young and adult rats; 2ME(2) does not appear to act via estrogen receptors and is active on bone at doses well below those required for tumor suppression in mice. 2ME(2), through a novel pathway, may be a useful alternative to conventional hormone replacement therapy for prevention of postmenopausal bone loss.
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7.54Impact points
2-methoxyestradiol up-regulates death receptor 5 and induces apoptosis through activation of the extrinsic pathway.
Cancer research. 02/2003; 63(2):468-75.
2-Methoxyestradiol (2ME2), a natural metabolite of estradiol, is a potent antitumor and antiangiogenic agent. In vitro, 2ME2 inhibits the proliferation of a wide variety of cell lines and primary cultures, and in numerous models in vivo, it has been shown to be an effective inhibitor of tumor growth... [more] 2-Methoxyestradiol (2ME2), a natural metabolite of estradiol, is a potent antitumor and antiangiogenic agent. In vitro, 2ME2 inhibits the proliferation of a wide variety of cell lines and primary cultures, and in numerous models in vivo, it has been shown to be an effective inhibitor of tumor growth and angiogenesis. 2ME2 is currently in several Phase I and Phase II clinical trials under the name Panzem. Although various molecular targets have been proposed for this compound, the mechanism by which 2ME2 exerts its effects is still uncertain. This study shows that 2ME2 uses the extrinsic pathway for induction of apoptosis. 2ME2 treatment results in up-regulation of death receptor 5 (DR5) protein expression in vitro and in vivo and renders cells more sensitive to the cytotoxic activities of the DR5 ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). 2ME2-induced apoptosis requires caspase activation and kinetic studies show the sequential activation of caspase-8, caspase-9, and caspase-3. Blockage of death receptor signaling by expression of dominant-negative Fas-associated death domain severely attenuates the ability of 2ME2 to induce apoptosis. Because 2ME2 administration has not manifested dose-limiting toxicity in the clinic, DR5 expression may serve as a surrogate marker for biological response.
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7.54Impact points
2-Methoxyestradiol inhibits proliferation and induces apoptosis independently of estrogen receptors alpha and beta.
Cancer research. 08/2002; 62(13):3691-7.
2-Methoxyestradiol (2ME(2)) is an endogenous metabolite of 17beta-estradiol (E(2)) that arises from the hydroxylation and subsequent methylation at the 2-position. In vitro 2ME(2) inhibits a large variety of tumor and nontumor cell lines from diverse origins, as well as several stages of the angioge... [more] 2-Methoxyestradiol (2ME(2)) is an endogenous metabolite of 17beta-estradiol (E(2)) that arises from the hydroxylation and subsequent methylation at the 2-position. In vitro 2ME(2) inhibits a large variety of tumor and nontumor cell lines from diverse origins, as well as several stages of the angiogenic cascade. In vivo it has been shown to be a very effective inhibitor of tumor growth and angiogenesis in numerous models. Although various molecular targets have been proposed for this compound, the mechanism of action is still uncertain. As this molecule emerges as a drug candidate it is important to assess the estrogen receptors (ERs) as molecular targets for 2ME(2). The purpose of this study was to investigate whether 2ME(2) is able to engage ERs as an agonist and whether its antiproliferative activities are mediated through ERs. We confirm that 2ME(2) has a lower binding affinity for ERalpha as compared with E(2) and other E(2) metabolites and antagonists, and we demonstrate that the affinity of 2ME(2) for ERbeta is even lower. When assessed in the presence of galangin, a cytochrome P450 enzyme inhibitor, at concentrations at which 2ME(2) interacts with ERalpha in an in vitro binding assay, it does not stimulate the proliferation of an estrogen-dependent breast carcinoma cell line. Similar IC(50) values for inhibition of proliferation and induction of apoptosis are obtained in estrogen-dependent and estrogen-independent human breast cancer cell lines, irrespective of the expression of ERalpha and ERbeta. Moreover, the estrogen antagonist ICI 182,780 does not inhibit the antiproliferative activity of 2ME(2). In E(2)-responsive cells such as MCF-7 and human umbilical vascular endothelial cells, high levels of E(2) inhibit the antiproliferative activity of ICI 182,780 but not of 2ME(2). Collectively, these results suggest that 2ME(2) is distinct among estradiol metabolites because of its inability to engage ERs as an agonist, and its unique antiproliferative and apoptotic activities are mediated independently of ERalpha and ERbeta.
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3.28Impact points
Studies on transcriptional regulation of the mucosal T-cell integrin alphaEbeta7 (CD103).
Immunology. 07/2001; 103(2):146-54.
Integrin alphaEbeta7 is expressed almost exclusively by mucosal T cells and mucosal dendritic antigen-presenting cells (APCs) and is thought to be induced locally by transforming growth factor-beta (TGF-beta). In mice, mRNA for the alphaE subunit was found to be abundant in mucosal T cells but absen... [more] Integrin alphaEbeta7 is expressed almost exclusively by mucosal T cells and mucosal dendritic antigen-presenting cells (APCs) and is thought to be induced locally by transforming growth factor-beta (TGF-beta). In mice, mRNA for the alphaE subunit was found to be abundant in mucosal T cells but absent from other tissues. Exposure of a T-cell line to TGF-beta strongly up-regulated alphaE mRNA levels within 30 min, and nuclear run-on experiments established that regulation occurred at the level of transcription. The organization of the human alphaE gene and a very closely linked novel gene, ELG, was determined. The alphaE promoter was tested in T cells and fibroblasts and functioned equally well in both cell types and did not confer TGF-beta responsiveness. Regions of the promoter providing enhancer activity and phorbol 12-myristate 13-acetate (PMA) responsiveness were identified by deletion studies. DNAse 1 hypersensitivity analysis of 36 kb of the alphaE gene revealed one hypersensitive site, found only in alphaE+ cells, located near the transcription start points. These results show that, unlike the situation with other integrins, lineage specificity and cytokine responsiveness of alphaE transcription are not conferred by the proximal promoter. Specificity may depend on distant control elements that have not yet been identified.
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Oxidative metabolism of murine macrophages.
Current protocols in immunology / edited by John E. Coligan ... [et al.]. 06/2001; Chapter 14:Unit 14.5.
This unit describes two simple and straightforward microassays that can be used to measure the levels of NO(2)(-) and O(2)(-), respectively that are generated by a small number of immunologically-stimulated macrophages. Detection of these products may be used to identify cytokine(s), microbe(s), or ... [more] This unit describes two simple and straightforward microassays that can be used to measure the levels of NO(2)(-) and O(2)(-), respectively that are generated by a small number of immunologically-stimulated macrophages. Detection of these products may be used to identify cytokine(s), microbe(s), or microbial products(s) that regulate oxidative metabolism and effector activity. Although a number of other reliable and sensitive methods are available for assaying these two oxidative metabolites, the microassays described here require little time, technical expertise, or materials. It is not clear at present whether human monocytes/macrophages can also produce NO(2)(-). These protocols are therefore restricted to mouse macrophages.
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5.33Impact points
Tissue factor pathway inhibitor inhibits endothelial cell proliferation via association with the very low density lipoprotein receptor.
The Journal of biological chemistry. 05/2001; 276(15):12241-8.
Tissue factor pathway inhibitor (TFPI) contains three Kunitz-type proteinase inhibitor domains and is a potent inhibitor of tissue factor-mediated coagulation. Here, we report that TFPI inhibits the proliferation of basic fibroblast growth factor-stimulated endothelial cells. A truncated form of TFP... [more] Tissue factor pathway inhibitor (TFPI) contains three Kunitz-type proteinase inhibitor domains and is a potent inhibitor of tissue factor-mediated coagulation. Here, we report that TFPI inhibits the proliferation of basic fibroblast growth factor-stimulated endothelial cells. A truncated form of TFPI, containing only the first two Kunitz-type proteinase inhibitor domains, has very little antiproliferative activity, suggesting that the carboxyl-terminal region of TFPI is responsible for this activity. Binding studies revealed that full-length TFPI, but not the truncated TFPI molecule, is recognized by the very low density lipoprotein receptor (VLDL receptor) indicating that this receptor is a novel high affinity endothelial cell receptor for TFPI. The antiproliferative activity of TFPI on endothelial cells is inhibited by the receptor-associated protein, a known antagonist of ligand binding by the VLDL receptor, and by anti-VLDL receptor antibodies. These results confirm that the antiproliferative activity of TFPI is mediated by the VLDL receptor and suggest that this receptor-ligand system may be a useful target for the development of new anti-angiogenic and antitumor agents.
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7.54Impact points
Metastatin: a hyaluronan-binding complex from cartilage that inhibits tumor growth.
Cancer research. 03/2001; 61(3):1022-8.
In this study, a hyaluronan-binding complex, which we termed Metastatin, was isolated from bovine cartilage by affinity chromatography and found to have both antitumorigenic and antiangiogenic properties. Metastatin was able to block the formation of tumor nodules in the lungs of mice inoculated wit... [more] In this study, a hyaluronan-binding complex, which we termed Metastatin, was isolated from bovine cartilage by affinity chromatography and found to have both antitumorigenic and antiangiogenic properties. Metastatin was able to block the formation of tumor nodules in the lungs of mice inoculated with B16BL6 melanoma or Lewis lung carcinoma cells. Single i.v. administration of Metastatin into chicken embryos inhibited the growth of both B16BL6 mouse melanoma and TSU human prostate cancer cells growing on the chorioallantoic membrane. The in vivo biological effect may be attributed to the antiangiogenic activity because Metastatin is able to inhibit the migration and proliferation of cultured endothelial cells as well as vascular endothelial growth factor-induced angiogenesis on the chorioallantoic membrane. In each case, the effect could be blocked by either heat denaturing the Metastatin or premixing it with hyaluronan, suggesting that its activity critically depends on its ability to bind hyaluronan on the target cells. Collectively, these results suggest that Metastatin is an effective antitumor agent that exhibits antiangiogenic activity.
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9.35Impact points
2-Methoxyestradiol: an endogenous antiangiogenic and antiproliferative drug candidate.
Cancer metastasis reviews. 02/2000; 19(1-2):173-9.
2-Methoxyestradiol, once considered an inacitve end-metabolite of estradiol, has recently emerged as a very promising agent for cancer treatment. It is orally active in a wide range of tumor models, and inhibits tumor growth at doses showing no clinical signs of toxicity. 2ME2 targets both the tumor... [more] 2-Methoxyestradiol, once considered an inacitve end-metabolite of estradiol, has recently emerged as a very promising agent for cancer treatment. It is orally active in a wide range of tumor models, and inhibits tumor growth at doses showing no clinical signs of toxicity. 2ME2 targets both the tumor cell and endothelial cell compartments by inducing apoptosis in rapidly proliferating cells and inhibiting blood vessel formation at several stages in the angiogenic cascade. Moreover, the ability of 2ME2 to inhibit metastatic spread in several models adds to its therapeutic value for cancer treatment at various stages of the disease. Though the mechanism of action is still undefined, several potential molecular targets and pathways of activation have been suggested.
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4.36Impact points
Nonrandomized comparison between stent deployment and percutaneous transluminal coronary angioplasty in acute myocardial infarction.
American heart journal. 02/2000; 139(1 Pt 1):44-51.
BACKGROUND: Compared with angioplasty, elective stent implantation has improved short-term and long-term outcome with a decrease in abrupt closure and a reduced 6-month restenosis rate. Although primary angioplasty during acute myocardial infarction has improved outcome, recurrent ischemic events an... [more] BACKGROUND: Compared with angioplasty, elective stent implantation has improved short-term and long-term outcome with a decrease in abrupt closure and a reduced 6-month restenosis rate. Although primary angioplasty during acute myocardial infarction has improved outcome, recurrent ischemic events and restenosis are still a problem. METHODS: Outcomes for 166 consecutively treated patients who underwent stent insertion procedures within 24 hours after the onset of acute myocardial infarction were compared with those for a similar group of patients (n = 212) who underwent consecutive balloon angioplasty procedures at one tertiary care institution. The objective of this study was to examine in-hospital and late clinical outcomes for the 2 groups. RESULTS: The procedural success rate for stenting in acute myocardial infarction was 100%; that for angioplasty was 98%. Mortality rates during hospitalization were similar for the stent group and the angioplasty group (4.0% vs 2.0%). The rate of in-hospital acute reocclusion necessitating urgent percutaneous reintervention was significantly lower for the stent group (0% vs 3%, P =.02). Six months after the procedure, the stent group had a significantly lower need for revascularization of the infarct-related artery (8% vs 20%, P =.001) and a significantly lower incidence of combined serious clinical events (death, acute occlusion, emergency bypass, target vessel revascularization, and nonfatal myocardial infarction; 12% vs 30%, P =.00003). CONCLUSION: Compared with balloon angioplasty, stent deployment in the setting of acute myocardial infarction was associated with significantly lower frequency of in-hospital acute occlusion and significantly less need for target-vessel revascularization 6 months after myocardial infarction.
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3.50Impact points
Alpha-galactosyl-mediated activation of porcine endothelial cells: studies on CD31 and VE-cadherin in adhesion and signaling.
Transplantation. 10/1999; 68(6):861-7.
BACKGROUND: Ligation of alpha-galactosyl epitopes on endothelial cells by naturally occurring human antibodies causes hyperacute rejection in porcine-to-human xenotransplantation. The alpha-galactosyl-specific lectin Bandeiraea simplicifolia isolectin B4 (IB4) has been reported to trigger endothelia... [more] BACKGROUND: Ligation of alpha-galactosyl epitopes on endothelial cells by naturally occurring human antibodies causes hyperacute rejection in porcine-to-human xenotransplantation. The alpha-galactosyl-specific lectin Bandeiraea simplicifolia isolectin B4 (IB4) has been reported to trigger endothelial "gap" formation and tyrosine phosphorylation of an unidentified 130-kDa protein. We have studied two 130-kDa junctional adhesion molecules, CD31 and VE-cadherin, in porcine aortic endothelial cells (PAECs) during IB4-mediated activation. The cellular distribution of these molecules, their susceptibility to tyrosine phosphorylation, and their capacity to bind IB4 or natural human antibodies have been determined. METHODS: Porcine CD31 and VE-cadherin were cloned. Recombinant proteins and monoclonal antibodies were prepared. The distribution and phosphorylation of CD31 and VE-cadherin in confluent PAECs activated with IB4 or human serum were studied by confocal microscopy and Western blotting, respectively. RESULTS: IB4 caused rapid redistribution of CD31 and VE-cadherin away from cell junctions and tyrosine-phosphorylation of CD31 but not VE-cadherin. A monoclonal antibody to CD31 also triggered tyrosine phosphorylation of this molecule, but brief exposure of PAECs to normal human serum did not. Tyrosine-phosphorylated CD31 complexed with SHP2 and other unidentified phosphoproteins. Both IB4 and natural human antibodies bound to porcine CD31 but not to VE-cadherin. Cell adhesion tests showed that porcine and human CD31 are functionally incompatible. CONCLUSIONS: Endothelial cell retraction during IB4-mediated activation of PAECs is associated with rapid loss of CD31 and VE-cadherin from cell junctions. CD31 becomes strongly tyrosine-phosphorylated and forms a cell signaling complex, which may have a significant role in the response of the xenograft vascular endothelium.
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4.80Impact points
Synthesis and enantiomeric separation of 2-phthalimidino-glutaric acid analogues: potent inhibitors of tumor metastasis.
Journal of medicinal chemistry. 09/1999; 42(16):3014-7.
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4.80Impact points
Indolequinone antitumor agents: correlation between quinone structure, rate of metabolism by recombinant human NAD(P)H:quinone oxidoreductase, and in vitro cytotoxicity.
Journal of medicinal chemistry. 12/1998; 41(24):4755-66.
A series of indolequinones bearing various functional groups has been synthesized, and the effects of substituents on the metabolism of the quinones by recombinant human NAD(P)H:quinone oxidoreductase (NQO1) were studied. Thus 5-methoxyindolequinones were prepared by the Nenitzescu reaction, followe... [more] A series of indolequinones bearing various functional groups has been synthesized, and the effects of substituents on the metabolism of the quinones by recombinant human NAD(P)H:quinone oxidoreductase (NQO1) were studied. Thus 5-methoxyindolequinones were prepared by the Nenitzescu reaction, followed by functional group interconversions. The methoxy group was subsequently displaced by amine nucleophiles to give a series of amine-substituted quinones. Metabolism of the quinones by NQO1 revealed that, in general, compounds with electron-withdrawing groups at the indole 3-position were among the best substrates, whereas those with amine groups at the 5-position were poor substrates. Compounds with a leaving group at the 3-indolyl methyl position generally inactivated the enzyme. The toxicity toward non-small-cell lung cancer cells with either high NQO1 activity (H460) or no detectable activity (H596) was also studied in representative quinones. Compounds which were good substrates for NQO1 showed the highest selectivity between the two cell lines.
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4.70Impact points
Expanded phase II trial of paclitaxel in metastatic breast cancer: a Southwest Oncology Group study.
Breast cancer research and treatment. 09/1998; 51(2):169-81.
BACKGROUND: The study was designed to evaluate the efficacy of paclitaxel in metastatic breast cancer patients. The design was motivated by a report from FDA and NCI staff proposing assessment of pre- and post-treatment symptoms as a means of evaluating treatment effectiveness [1]. METHODS: Patients... [more] BACKGROUND: The study was designed to evaluate the efficacy of paclitaxel in metastatic breast cancer patients. The design was motivated by a report from FDA and NCI staff proposing assessment of pre- and post-treatment symptoms as a means of evaluating treatment effectiveness [1]. METHODS: Patients with symptomatic and/or measurable metastatic breast cancer with prior treatment received paclitaxel 210 mg/m2 as a 3 hour infusion every three weeks until toxicity or progression. A unique endpoint was subjective symptomatic response, defined as an improvement in the Symptom Distress Scale score by > or = 3 points at two successive evaluations before treatment failure. Patients were also evaluated for objective response and toxicity. RESULTS: Of 135 patients registered, 123 were eligible and treated. The subjective symptomatic response rate for 93 symptomatic patients who completed forms was 40%, 95% confidence interval 29-51%. The objective response rate in 77 patients with measurable disease was 19%, 95% confidence interval 11-30%. In patients with both measurable and symptomatic disease, 37% had symptomatic and 13% had objective responses. Median times to treatment failure and death were 4 and 11 months, respectively. Toxicity was greater than anticipated: 12% discontinued treatment due to toxicity, 29% developed at least one Grade 3 neuromuscular toxicity, and two patients died of sepsis while neutropenic. CONCLUSION: Paclitaxel by 3 hour infusion at a dose of 210 mg/m2 produced excessive neurotoxicity in patients with previously treated metastatic breast cancer. Both sustained subjective symptom reduction and objective responses were demonstrated, but dose reduction for routine practice is recommended.
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29.75Impact points
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4.21Impact points
Inhibition of nitric oxide interrupts the accumulation of CD8+ T cells surrounding Plasmodium berghei-infected hepatocytes.
Infection and immunity. 10/1997; 65(9):3882-8.
The elimination of liver-stage malaria parasites by nitric oxide (NO)-producing hepatocytes is regulated by T cells. Both CD8+ and CD4+ T cells, which surround infected hepatocytes, are evident by 24 h after sporozoite challenge in Brown Norway rats previously immunized with irradiated Plasmodium be... [more] The elimination of liver-stage malaria parasites by nitric oxide (NO)-producing hepatocytes is regulated by T cells. Both CD8+ and CD4+ T cells, which surround infected hepatocytes, are evident by 24 h after sporozoite challenge in Brown Norway rats previously immunized with irradiated Plasmodium berghei sporozoites. While the number of CD4+ T cells remained the same beyond 24 h postchallenge, the number of CD8+ T cells increased three- and sixfold by 31 and 44 h, respectively. This increase in the number of CD8+ T cells correlated with a decrease in the number of intrahepatic parasites. In immunized rats, intrahepatic parasites were reduced in number by 31 h after sporozoite challenge and cleared from the liver by 44 h, as visualized by P. berghei-specific DNA in situ hybridization. If immunized rats were treated with aminoguanidine, a substrate inhibitor of NO synthase, at the time of challenge, liver-stage protection was blocked, as shown by the increase in parasite liver burden. Further histological examination of infected livers from immunized animals treated with aminoguanidine revealed fewer and smaller cellular infiltrates surrounding the infected hepatocytes, and the number of CD8+ T cells that normally accumulate within the infiltrates was drastically reduced. Consequently, the infected hepatocytes were not cleared from the liver. We hypothesize that the early production of NO may promote the influx and/or enhance local proliferation of malaria parasite-specific CD8+ T cells or a CD8+ T-cell subset which is required for parasite clearance.
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17.79Impact points
Megestrol acetate and aminoglutethimide/hydrocortisone in sequence or in combination as second-line endocrine therapy of estrogen receptor-positive metastatic breast cancer: a Southwest Oncology Group phase III trial.
Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 08/1997; 15(7):2494-501.
PURPOSE: A phase III randomized trial was performed to determine whether combination hormonal therapy with aminoglutethimide (AG) and hydrocortisone (HC) plus megestrol acetate (MA) improved response rates, response duration, or increased survival over the sequential use of each hormone in women wit... [more] PURPOSE: A phase III randomized trial was performed to determine whether combination hormonal therapy with aminoglutethimide (AG) and hydrocortisone (HC) plus megestrol acetate (MA) improved response rates, response duration, or increased survival over the sequential use of each hormone in women with estrogen receptor-positive metastatic breast cancer (MBC) who had maintained stable disease for at least 6 months or responded to tamoxifen. PATIENTS AND METHODS: Two hundred eighty-eight postmenopausal women with progressive estrogen receptor-positive MBC were randomly selected to receive MA 40 mg four times daily (arm I), AG 250 mg four times daily with HC 40 mg daily in divided doses (arm II), versus the combination of MA plus AG given at the same dosages (arm III). Patients on arms I and II who progressed after an adequate trial were crossed over to the other treatment arm. RESULTS: Two hundred thirty-five eligible patients were evaluated for response, time to treatment failure, and survival. Response was only reported for patients with measurable disease and was not statistically different among the three arms. There were two partial responses (PRs) on MA (6%), four complete responses (CRs) and six PRs on AG (24%), and eight PRs and three CRs on MA plus AG (23%) in 32, 42, and 48 measurable patients, respectively. Median times to treatment failure were also similar at 5, 4, and 7 months. Survival was also not statistically different among the three arms at 26, 27, and 26 months for arms I, II, and III, respectively. Toxicity was greater in the two AG arms with respect to fatigue, nausea and vomiting, and rash. CONCLUSION: With the exception of toxicity, there is no response, time to treatment failure, or survival benefit for any one group when comparing MA, AG, or the combination at their stated doses in women with estrogen receptor-positive MBC who had previously responded to or stabilized with tamoxifen.
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5.33Impact points
Identification of a binding site for integrin alphaEbeta7 in the N-terminal domain of E-cadherin.
The Journal of biological chemistry. 12/1996; 271(48):30909-15.
The integrin alphaEbeta7, which is predominantly expressed on mucosal T lymphocytes, has recently been shown to recognize the cell adhesion molecule, E-cadherin, on epithelial cells. We have carried out mutations on E-cadherin, involving domain deletions as well as substitutions of specific amino ac... [more] The integrin alphaEbeta7, which is predominantly expressed on mucosal T lymphocytes, has recently been shown to recognize the cell adhesion molecule, E-cadherin, on epithelial cells. We have carried out mutations on E-cadherin, involving domain deletions as well as substitutions of specific amino acids, in order to identify the sites recognized by the integrin. Binding of alphaEbeta7 required the presence of the first two N-terminal domains of E-cadherin. Deletion of extracellular domains 3 and 4 or truncation of the cytoplasmic domain of E-cadherin had no consequence on integrin binding. Substitution of a glutamic acid in the BC loop of the Ig structure of the fist, N-terminal, domain of E-cadherin abrogated binding of alphaEbeta7. This mutation did not appear to affect the conformation of the domain nor the pattern of expression of E-cadherin on the cell surface. Synthetic peptides encompassing the first domain of E-cadherin had very little inhibitory effect on the interaction with alphaEbeta7. Our results highlight structural dissimilarities between recognition of E-cadherin by alphaEbeta7 and recognition of other members of the IgSF by integrins and show that the heterophilic (integrin binding) and homophilic sites in the N-terminal domain of E-cadherin are distinct.
