Journal Article

in vivo imaging; ProSense; GI imaging

N/A

Journal Article

Ovarian cancer; Molecular imaging; Intraoperative imaging; Fluorescence imaging

OBJECTIVES: Cytoreductive surgery is a cornerstone of therapy in metastatic ovarian cancer. While conventional white light (WL) inspection detects many obvious tumor foci, careful histologic comparison has shown considerable miss rates for smaller foci. The goal of this study was to compare tumor detection using WL versus near infrared (NIR) imaging with a protease activatable probe, as well as to evaluate the ability to quantify NIR fluorescence using a novel quantitative optical imaging system.

METHODS: A murine model for peritoneal carcinomatosis was generated and metastatic foci were imaged using WL and NIR imaging following the i.v. administration of the protease activatable probe ProSense750. The presence of tumor was confirmed by histology. Additionally, the ability to account for variations in fluorescence signal intensity due to changes in distance between the catheter and target lesion during laparoscopic procedures was evaluated.

RESULTS: NIR imaging with a ProSense750 significantly improved upon the target-to-background ratios (TBRs) of tumor foci in comparison to WL imaging (minimum improvement was approximately 3.5 fold). Based on 52 histologically validated samples, the sensitivity for WL imaging was 69%, while the sensitivity for NIR imaging was 100%. The effects of intraoperative distance changes upon fluorescence intensity were corrected in realtime, resulting in a decrease from 89% to 5% in signal variance during fluorescence laparoscopy.

CONCLUSIONS: With its molecular specificity, low background autofluorescence, high TBRs, and quantitative signal, optical imaging with NIR protease activatable probes greatly improves upon the intraoperative detection of ovarian cancer metastases.

Journal Article

AngioSense

Macrophages are central regulators of disease progression in both atherosclerosis and myocardial infarction (MI). In atherosclerosis, macrophages are the dominant leukocyte population that influences lesional development. In MI, which is caused by atherosclerosis, macrophages accumulate readily and have important roles in inflammation and healing. Molecular imaging has grown considerably as a field and can reveal biological process at the molecular, cellular and tissue levels. Here, we explore how various imaging modalities, from intravital microscopy in mice to organ-level imaging in patients, are contributing to our understanding of macrophages and their progenitors in cardiovascular disease.Immunology and Cell Biology advance online publication, 4 December 2012; doi:10.1038/icb.2012.72.

Journal Article

Xen26, Xen 26, Salmonella typhumurium, Animals; Anti-Bacterial Agents/therapeutic use; Cell Separation; Disease Models, Animal; Flow Cytometry; Fluoroquinolones/therapeutic use; Intestine, Small/microbiology; Lymph Nodes/*microbiology; Mesentery/immunology/microbiology; Mice; Mice, Inbred C57BL; Monocytes/immunology/*microbiology; Recurrence; Salmonella Infections, Animal/immunology/*microbiology/pathology; Salmonella typhi/immunology

Enteric pathogens can cause relapsing infections in a proportion of treated patients, but greater understanding of this phenomenon is hindered by the lack of appropriate animal models. We report here a robust animal model of relapsing primary typhoid that initiates after apparently successful antibiotic treatment of susceptible mice. Four days of enrofloxacin treatment were sufficient to reduce bacterial loads below detectable levels in all major organs, and mice appeared otherwise healthy. However, any interruption of further antibiotic therapy allowed renewed fecal shedding and renewed bacterial growth in systemic tissues to occur, and mice eventually succumbed to relapsing infection. In vivo imaging of luminescent Salmonella identified the mesenteric lymph nodes (MLNs) as a major reservoir of relapsing infection. A magnetic-bead enrichment strategy isolated MLN-resident CD11b(+) Gr-1(-) monocytes associated with low numbers of persistent Salmonella. However, the removal of MLNs increased the severity of typhoid relapse, demonstrating that this organ serves as a protective filter to restrain the dissemination of bacteria during antibiotic therapy. Together, these data describe a robust animal model of typhoid relapse and identify an important intestinal phagocyte subset involved in protection against the systemic spread of enteric infection.

Journal Article

Animals; Bacterial Toxins; Biliary Tract; Bioware; Feces; Food Contamination; Intestines; Listeria monocytogenes; Listeriosis; Mice; Mice, Inbred BALB C; pXen-5

Listeria monocytogenes is a ubiquitous gram-positive bacterium that can cause systemic and often life-threatening disease in immunocompromised hosts. This organism is largely an intracellular pathogen; however, we have determined that it can also grow extracellularly in animals, in the lumen of the gallbladder. The significance of growth in the gallbladder with respect to the pathogenesis and spread of listeriosis depends on the ability of the bacterium to leave this organ and be disseminated to other tissues and into the environment. Should this process be highly inefficient, growth in the gallbladder would have no impact on pathogenesis or spread, but if it occurs efficiently, bacterial growth in this organ may contribute to listeriosis and dissemination of this organism. Here, we use whole-body imaging to determine the efficacy and kinetics of food- and hormone-induced biliary excretion of L. monocytogenes from the murine gallbladder, demonstrating that transit through the bile duct into the intestine can occur within 5 min of induction of gallbladder contraction by food or cholecystokinin and that movement of bacteria through the intestinal lumen can occur very rapidly in the absence of fecal material. These studies demonstrate that L. monocytogenes bacteria replicating in the gallbladder can be expelled from the organ efficiently and that the released bacteria move into the intestinal tract, where they pass into the environment and may possibly reinfect the animal.