Citation Details

Journal Article

Xen41, Xen 41, Pseudomonas aeruginosa Xen41, IVIS

BACKGROUND: : Experimental models of intestinal ischemia-reperfusion (IIR) injury are invariably performed in mice harboring their normal commensal flora, even though multiple IIR events occur in humans during prolonged intensive care confinement when they are colonized by a highly pathogenic hospital flora. The aims of this study were to determine whether the presence of the human pathogen Pseudomonas aeruginosa in the distal intestine potentiates the lethality of mice exposed to IIR and to determine what role any in vivo virulence activation plays in the observed mortality. METHODS: : Seven- to 9-week-old C57/BL6 mice were exposed to 15 minutes of superior mesenteric artery occlusion (SMAO) followed by direct intestinal inoculation of 1.0 x 10 colony-forming unit of P. aeruginosa PAO1 into the ileum and observed for mortality. Reiterative studies were performed in separate groups of mice to evaluate both the migration/dissemination pattern and in vivo virulence activation of intestinally inoculated strains using live photon camera imaging of both a constitutive bioluminescent P. aeruginosa PAO1 derivative XEN41 and an inducible reporter derivative of PAO1, the PAO1/lecA:luxCDABE that conditionally expresses the quorum sensing-dependent epithelial disrupting virulence protein PA 1 Lectin (PA-IL). RESULTS: : Mice exposed to 15 minutes of SMAO and reperfusion with intestinal inoculation of P. aeruginosa had a significantly increased mortality rate (p < 0.001) of 100% compared with <10% for sham-operated mice intestinally inoculated with P. aeruginosa without SMAO and IIR alone (<50%). Migration/dissemination patterns of P. aeruginosa in mice subjected to IIR demonstrated proximal migration of distally injected strains and translocation to mesenteric lymph nodes, liver, spleen, lung, and kidney. A key role for in vivo virulence expression of the barrier disrupting adhesin PA-IL during IIR was established since its expression was enhanced during IR and mutant strains lacking PA-IL displayed attenuated mortality. CONCLUSIONS: : The presence of intestinal P. aeruginosa potentiates the lethal effect of IIR in mice in part due to in vivo virulence activation of its epithelial barrier disrupting protein PA-IL.

Journal Article

Xen5, Xen39, Xen26, Xen14, Xen36, Xen 5, Xen 39, Xen 26, Xen 14, Xen 36, Psuedomonas aeruginosa, S. aureus, Klebsiella, E. coli, Salmonella,

The 3(2H) furanone derivative 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) was investigated for its antimicrobial and cell-adhesion inhibition properties against Klebsiella pneumoniae Xen 39, Staphylococcus aureus Xen 36, Escherichia coli Xen 14, Pseudomonas aeruginosa Xen 5 and Salmonella typhimurium Xen 26. Nanofibers electrospun from solution blends of DMHF and poly(vinyl alcohol) (PVA) were tested for their ability to inhibit surface-attachment of bacteria. Antimicrobial and adhesion inhibition activity was determined via the plate counting technique. To quantify viable but non-culturable cells and to validate the plate counting results, bioluminescence and fluorescence studies were carried out. Nanofiber production was upscaled using the bubble electrospinning technique. To ascertain that no DMHF leached into filtered water, samples of water filtered through the nanofibrous mats were analyzed using gas chromatography coupled with mass spectrometry (GC-MS). Scanning electron microscopy (SEM) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) were used to characterize the electrospun nanofibers.

Journal Article

BxPC-3, BxPC-3-luc2, IVIS, Achyranthes; Animals; Antineoplastic Agents, Phytogenic/pharmacology/*therapeutic use; Apoptosis/*drug effects; Caspase 3/genetics/metabolism; Gene Expression/drug effects; Humans; Injections, Intraperitoneal; Medicine, Ayurvedic; Mice; Mice, Nude; Pancreatic Neoplasms/*drug therapy/genetics/metabolism; Phosphorylation; *Phytotherapy; Plant Extracts/pharmacology/*therapeutic use; Plant Leaves; Proto-Oncogene Proteins c-akt/metabolism; RNA, Messenger/metabolism; Xenograft Model Antitumor Assays

ETHNOPHARMACOLOGICAL RELEVANCE: Achyranthes aspera (Family Amaranthacea) is used for cancer therapy by ayurvedic medical practitioners in India. However, due to the non formal nature of its use, there are no systematic studies validating its medicinal properties. Thus, it's utility as an anti cancer agent remains anecdotal. Earlier, we demonstrated A. aspera to exhibit time and dose-dependent preferential cytotoxicity to cultured human pancreatic cancer cells. In this report we validate in vivo anti tumor properties of A. aspera. MATERIALS AND METHODS: The in vivo anti tumor activity of leaf extract (LE) was tested by intraperitoneal (IP) injections into athymic mice harboring human pancreatic tumor subcutaneous xenograft. Toxicity was monitored by recording changes in behavioral, histological, hematological and body weight parameters. RESULTS: Dosing LE to athymic mice by I.P. injection for 32 days showed no adverse reactions in treated mice. Compared to the control set, IP administration of LE to tumor bearing mice significantly reduced both tumor weight and volume. Gene expression analysis using Real time PCR methods revealed that LE significantly induced caspase-3 mRNA (p<0.001) and suppressed expression of the pro survival kinase Akt-1 (p<0.05). TUNEL assay and immunohistochemistry confirmed apoptosis induction by activation of caspase-3 and inhibiting Akt phosphorylation in treated sets. These results are in agreement with RT PCR data. CONCLUSION: Taken together, these data suggest A. aspera to have potent anti cancer property.

Journal Article

U-87 MG-luc2, U-87-MG-luc2, Glioma, Bioware, IVIS, Animals; Brachytherapy/*methods; Brain Neoplasms/pathology/*radiotherapy; Convection; Glioblastoma/pathology/*radiotherapy; Glioma/pathology/*radiotherapy; Liposomes; Nanoparticles/therapeutic use; Radioisotopes/*therapeutic use; Rats; Rhenium/*therapeutic use; Tumor Burden; Xenograft Model Antitumor Assays

Although external beam radiation is an essential component to the current standard treatment of primary brain tumors, its application is limited by toxicity at doses more than 80 Gy. Recent studies have suggested that brachytherapy with liposomally encapsulated radionuclides may be of benefit, and we have reported methods to markedly increase the specific activity of rhenium-186 ((186)Re)-liposomes. To better characterize the potential delivery, toxicity, and efficacy of the highly specific activity of (186)Re-liposomes, we evaluated their intracranial application by convection-enhanced delivery in an orthotopic U87 glioma rat model. After establishing an optimal volume of 25 microL, we observed focal activity confined to the site of injection over a 96-hour period. Doses of up to 1850 Gy were administered without overt clinical or microscopic evidence of toxicity. Animals treated with (186)Re-liposomes had a median survival of 126 days (95% confidence interval [CI], 78.4-173 days), compared with 49 days (95% CI, 44-53 days) for controls. Log-rank analysis between these 2 groups was highly significant (P = .0013) and was even higher when 100 Gy was used as a cutoff (P < .0001). Noninvasive luciferase imaging as a surrogate for tumor volume showed a statistically significant separation in bioluminescence by 11 days after 100 Gy or less treatment between the experimental group and the control animals (chi(2)[1, N= 19] = 4.8; P = .029). MRI also supported this difference in tumor size. Duplication of tumor volume differences and survival benefit was possible in a more invasive U251 orthotopic model, with clear separation in bioluminescence at 6 days after treatment (chi(2)[1, N= 9] = 4.7; P = .029); median survival in treated animals was not reached at 120 days because lack of mortality, and log-rank analysis of survival was highly significant (P = .0057). Analysis of tumors by histology revealed minimal areas of necrosis and gliosis. These results support the potential efficacy of the highly specific activity of brachytherapy by (186)Re-liposomes convection-enhanced delivery in glioma.

Journal Article

Colo205-luc2, colorectal cancer, Bioware, IVIS

PURPOSE: The carbohydrate antigen sialyl-Lewis(a) (sLe(a)), also known as CA19.9, is widely expressed on epithelial tumors of the gastrointestinal tract and breast and on small-cell lung cancers. Since overexpression of sLe(a) appears to be a key event in invasion and metastasis of many tumors and results in susceptibility to antibody-mediated lysis, sLe(a) is an attractive molecular target for tumor therapy. EXPERIMENTAL DESIGN: We generated and characterized fully human monoclonal antibodies (mAb) from blood lymphocytes from individuals immunized with a sLe(a)-KLH vaccine. RESULTS: Several mAbs were selected based on ELISA and FACS including two mAbs with high affinity for sLe(a) (5B1 and 7E3, binding affinities 0.14 and 0.04 nmol/L, respectively) and further characterized. Both antibodies were specific for Neu5Acalpha2-3Galbeta1-3(Fucalpha1-4)GlcNAcbeta as determined by glycan array analysis. Complement-dependent cytotoxicity against DMS-79 cells was higher (EC(50) 0.1 mug/mL vs. 1.7 mug/mL) for r7E3 (IgM) than for r5B1 (IgG1). In addition, r5B1 antibodies showed high level of antibody-dependent cell-mediated cytotoxicity activity on DMS-79 cells with human NK cells or peripheral blood mononuclear cells. To evaluate in vivo efficacy, the antibodies were tested in a xenograft model with Colo205 tumor cells engrafted into SCID (severe combined immunodeficient mice) mice. Treatment during the first 21 days with four doses of r5B1 (100 mug per dose) doubled the median survival time to 207 days, and three of five animals survived with six doses. CONCLUSION: On the basis of the potential of sLe(a) as a target for immune attack and their affinity, specificity, and effector functions, 5B1and 7E3 may have clinical utility.