Citation Details

Journal Article

Bioware; MCF-7-luc-F5 cells

A clonal human tumor cell line expressing firefly luciferase, MCF-7-luc-F5, was developed from parental MCF-7 breast carcinoma cells and characterized for bioluminescence in vitro and in vivo. As few as twenty cells were detectable in vitro and average bioluminescence measured approximately 680 photons/sec/cell. Tumorigenesis of MCF-7-luc-F5 cells was assessed with and without estrogen supplement in vivo following injection of cells into the mammary fat pad of nude-beige mice. Continuous tumor growth was observed by weekly bioluminescent imaging in mice receiving a slow release (60 day) estrogen pellet implant (0.36 mg/pellet), while no tumor growth occurred in mice without estrogen supplement. Caliper measurements of tumor volume indicated similar results. A kinetic analysis of luciferase activity in vivo demonstrated that peak signals were evident approximately 12-15 minutes after injection of luciferin substrate and were maintained at a relatively stable level for at least another 20-25 minutes. Spontaneous metastasis from the primary mammary fat pad tumor to thoracic and axillary regions was observed in vivo in 50% of the animals. Subsequent ex vivo images and histology identified metastatic sites in lung, rib, or lymph nodes depending on the mouse. Standard drug treatment on primary and secondary tumor growth was also monitored by bioluminescent imaging.

Journal Article

Animals; Bioware; Carcinoma; Cell Proliferation; Colonic Neoplasms; DNA Damage; Drug Therapy, Combination; Female; HT-29-luc-D6 cells; Humans; Hydrogen peroxide; Hyperthermia, Induced; Injections, Intraperitoneal; Mice; Mice, Nude; Oxidants; Oxidative Stress; Survival Rate; tert-Butylhydroperoxide; Treatment Outcome; Tumor Cells, Cultured

BACKGROUND The purpose of this study was to extend our in vitro observations that induced oxidative stress under hyperthermic conditions decreases tumor cell growth into a preclinical murine model of hyperthermic perfusion. METHODS A nude mouse model of colon cancer carcinomatosis with HT-29-Luc-D6 colon cancer cells was established, and tumor growth was measured by serial bioluminescent imaging. RESULTS By means of a survival model of hyperthermic perfusion, we demonstrated that perfusion with normothermic saline decreased tumor growth compared with no perfusion controls, and tumor growth was further decreased with hyperthermic perfusion alone. The induction of oxidative stress with hydrogen peroxide in the perfusate at concentrations as high as 600 microM was well tolerated in this model of hyperthermic perfusion. Importantly, induced oxidative stress using hydrogen peroxide under hyperthermic conditions significantly decreased in vivo tumor cell growth compared with all other controls. CONCLUSIONS On the basis of our observations, thermal sensitization through modulation of cellular oxidative stress may represent a novel approach to increase the efficacy of hyperthermia as an anticancer modality.

Journal Article

Abdominal Wall; Animals; Bioware; Female; Luminescent Measurements; Mice; Mice, Inbred BALB C; Polypropylenes; Polytetrafluoroethylene; pXen-5; Staphylococcal Infections; Staphylococcus aureus; Surgical Mesh; Xen29

OBJECTIVE To study the influence of morphology of surgical meshes on the course of bacterial infection under the influence of the host immune system in an in vivo chronic bacterial infection model. BACKGROUND The use of prosthetic meshes has increased dramatically the last decades in abdominal wall reconstructive surgery. Whereas infection is becoming a more frequent complication, attention is increasingly drawn to the influence of the surgeon's mesh choice on the course of this complication. METHODS Samples of 6 often applied surgical meshes were contaminated with a bioluminescent strain of Staphylococcus aureus and implanted subcutaneously in an immunocompetent BALB/c mouse. The intensity and the spreading of bioluminescence (ie, p/s/cm/sr) were analyzed non-invasively in vivo during a 10-day follow-up period. RESULTS Over the course of infection, multifilament polypropylene and hydrophobic materials showed a significantly higher persistence of bacteria as well as spreading of infection compared to all other meshes. In contrast, infection resolved in almost all animals with a low-weight polyester mesh. CONCLUSION The results of this study are in accordance with circumstantial evidence from limited clinical reports on infection involving surgical meshes and suggest that multifilament and hydrophobic meshes significantly increase bacterial persistence or spreading in the infected area in contrast to monofilament polypropylene and lightweight meshes. Therefore, the surgeon should consider this outcome when choosing a mesh graft for limiting infection in abdominal wall repair.

Journal Article

Amino Acid Transport Systems, Neutral; Animals; Bacterial Proteins; Bioware; Blotting, Northern; Disease Models, Animal; Gene Expression Regulation, Bacterial; Humans; Lac Operon; Mice; Osmolar Concentration; Proline; pXen-5; Recombinant Fusion Proteins; Staphylococcal Infections; Staphylococcus aureus; Symporters; Transcriptional Activation

Staphylococcus aureus can grow virtually anywhere in the human body but needs to import proline through low- and high-affinity proline transporters to survive. This study examined the regulation of the S. aureus putP gene, which encodes a high-affinity proline permease. putP::lacZ and putP::lux transcriptional fusions were constructed and integrated into the genomes of several S. aureus strains. Enzyme activity was measured after growth in media with various osmolyte concentrations. As osmolarity rose, putP expression increased, with a plateau at 2 M for NaCl in strain LL3-1. Proline concentrations as low as 17.4 muM activated expression of the putP gene. The putP::lux fusion was also integrated into the genomes of S. aureus strains that were either SigB inactive (LL3-1, 8325-4, and SH1003) or SigB active (Newman and SH1000). SigB inactive strains showed increased putP gene expression as NaCl concentrations rose, whereas SigB active strains displayed a dramatic decrease in putP expression, suggesting that the alternative sigma factor B plays a negative role in putP regulation. Mice inoculated with S. aureus strains containing the putP::lux fusion exhibited up to a 715-fold increase in putP expression, although levels in the various murine organs differed. Moreover, urine from human patients infected with S. aureus showed elevated putP levels by use of a PCR procedure, whereas blood and some abscess material had no significant increase. Thus, putP is transcriptionally activated by a low-proline and high osmotic environment both in growth media and in murine or human clinical specimens.

Journal Article

Aminolevulinic Acid; Animals; Biofilms; Bioware; Cell Survival; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Implants, Experimental; Light; Luminescent Measurements; Methylene Blue; Osteomyelitis; Photochemotherapy; Photosensitizing Agents; Rats; Rats, Sprague-Dawley; Staphylococcus aureus; Xen29

Osteomyelitis can lead to severe morbidity and even death resulting from an acute or chronic inflammation of the bone and contiguous structures due to fungal or bacterial infection. Incidence approximates 1 in 1000 neonates and 1 in 5000 children in the United States annually and increases up to 0.36% and 16% in adults with diabetes or sickle cell anaemia, respectively. Current regimens of treatment include antibiotics and/or surgery. However, the increasing number of antibiotic resistant pathogens suggests that alternate strategies are required. We are investigating photodynamic therapy (PDT) as one such alternate treatment for osteomyelitis using a bioluminescent strain of biofilm-producing staphylococcus aureus (S. aureus) grown onto kirschner wires (K-wire). S. aureus-coated K-wires were exposed to methylene blue (MB) or 5-aminolevulinic acid (ALA)-mediated PDT either in vitro or following implant into the tibial medullary cavity of Sprague-Dawley rats. The progression of S. aureus biofilm was monitored non-invasively using bioluminescence and expressed as a percentage of the signal for each sample immediately prior to treatment. S. aureus infections were subject to PDT 10 days post inoculation. Treatment comprised administration of ALA (300 mg kg(-1)) intraperitoneally followed 4 h later by light (635 +/- 10 nm; 75 J cm(-2)) delivered transcutaneously via an optical fiber placed onto the tibia and resulted in significant delay in bacterial growth. In vitro, MB and ALA displayed similar cell kill with > or =4 log(10) cell kill. In vivo, ALA-mediated PDT inhibited biofilm implants in bone. These results confirm that MB or ALA-mediated PDT have potential to treat S. aureus cultures grown in vitro or in vivo using an animal model of osteomyelitis.