The N1 domain of the peroxisomal AAA-ATPase Pex6 is required for Pex15 binding and proper assembly with Pex1.

The heterohexameric ATPases associated with diverse cellular activities (AAA)-ATPase Pex1/Pex6 is essential for the formation and maintenance of peroxisomes. Pex1/Pex6, similar to other AAA-ATPases, uses the energy from ATP hydrolysis to mechanically thread substrate proteins through its central pore, thereby unfolding them. In related AAA-ATPase motors, substrates are recruited through binding to the motor's N-terminal domains or N terminally bound cofactors. Here, we use structural and biochemical techniques to characterize the function of the N1 domain in Pex6 from budding yeast, Saccharomyces cerevisiae. We found that although Pex1/ΔN1-Pex6 is an active ATPase in vitro, it does not support Pex1/Pex6 function at the peroxisome in vivo. An X-ray crystal structure of the isolated Pex6 N1 domain shows that the Pex6 N1 domain shares the same fold as the N-terminal domains of PEX1, CDC48, and NSF, despite poor sequence conservation. Integrating this structure with a cryo-EM reconstruction of Pex1/Pex6, AlphaFold2 predictions, and biochemical assays shows that Pex6 N1 mediates binding to both the peroxisomal membrane tether Pex15 and an extended loop from the D2 ATPase domain of Pex1 that influences Pex1/Pex6 heterohexamer stability. Given the direct interactions with both Pex15 and the D2 ATPase domains, the Pex6 N1 domain is poised to coordinate binding of cofactors and substrates with Pex1/Pex6 ATPase activity.

Insights into the Structure and Function of the Pex1/Pex6 AAA-ATPase in Peroxisome Homeostasis.

The AAA-ATPases Pex1 and Pex6 are required for the formation and maintenance of peroxisomes, membrane-bound organelles that harbor enzymes for specialized metabolism. Together, Pex1 and Pex6 form a heterohexameric AAA-ATPase capable of unfolding substrate proteins via processive threading through a central pore. Here, we review the proposed roles for Pex1/Pex6 in peroxisome biogenesis and degradation, discussing how the unfolding of potential substrates contributes to peroxisome homeostasis. We also consider how advances in cryo-EM, computational structure prediction, and mechanisms of related ATPases are improving our understanding of how Pex1/Pex6 converts ATP hydrolysis into mechanical force. Since mutations in PEX1 and PEX6 cause the majority of known cases of peroxisome biogenesis disorders such as Zellweger syndrome, insights into Pex1/Pex6 structure and function are important for understanding peroxisomes in human health and disease.

Multiple Opioid Prescribers During the Perioperative Period Increases Opioid Consumption Following Upper Extremity Surgery: A Multicenter Analysis.

Background Opioid prescribing practices have been an area of interest for orthopedic surgeons in the wake of the opioid epidemic. Previous studies have investigated the effects of a multitude of patient-specific risk factors on prolonged opioid use postoperatively. However, to date, there is a lack of studies examining the effects of multiple prescribers during the perioperative period and their potential contribution to prolonged opioid use postoperatively. This study aimed to investigate if multiple unique opioid prescribers perioperatively predispose patients to prolonged opioid use following upper extremity surgery. Second, we compared opioid prescribing patterns among different medical specialties. Methodology This retrospective study was conducted at three academic institutions. Between April 30, 2018, and August 30, 2019, 634 consecutive patients who underwent one of three upper extremity procedures  were included in the analysis: carpal tunnel release (CTR), basal joint arthroplasty (BJA), or distal radius fracture open reduction and  internal fixation (DRF ORIF). Prescription information was collected using the state Prescription Drug Monitoring Program (PDMP) online database  from a period of three months preoperatively to six months postoperatively. A Google search was performed to group prescriptions by medical specialty.  Dependent outcomes included whether patients filled an additional opioid prescription postoperatively and prolonged opioid use (defined as opioid use three to six months postoperatively). Results In total, 634 patients were identified, including 276 CTRs, 217 DRF ORIFs, and 141 BJAs. This consisted of 196 males (30.9%) and 438 females (69.1%) with an average age of 59.4 years (SD: 14.7 years). By six months postoperatively, 191 (30.1%) patients filled an additional opioid prescription, and 89 (14.0%) experienced prolonged opioid use. In total, 235 (37.1%) patients had more than one unique opioid prescriber during the study period (average 2.5 prescribers). Patients with more than one unique opioid prescriber were significantly more likely to have received overlapping opioid prescriptions (15.7% vs. 0.8%, p<.001), to have filled an additional opioid prescription postoperatively (63.8% vs 10.3%, p<.001), and to have experienced prolonged opioid use postoperatively (35.3% vs 1.5%, p<.001) compared to patients with only one opioid prescriber. Patients with multiple unique prescribers filled more opioid prescriptions compared to those with a single prescriber (2.8 refills vs 1.8 refills, p=.035). Within six months postoperatively, 71.4% of opioid refills were written by non-orthopedic providers. Opioid refills written by non-orthopedic prescribers were written for a significantly greater number of pills (68.4 vs. 27.9, p<.001), for a longer duration (22.2 vs. 6.2 days, p<.001), and for larger total morphine milligram equivalents per prescription (831.4 vs. 169.8, p<.001) compared to those written by orthopedic prescribers. Conclusions Patients with multiple unique opioid prescribers during the perioperative period are at a higher risk for prolonged opioid use postoperatively. Non-orthopedic providers were the highest prescribers of opioids postoperatively, and they prescribed significantly larger and longer prescriptions. Our findings highlight the value of utilizing PDMP databases to help curtail opioid overprescription and potential adverse opioid-related outcomes following upper extremity surgery.

Larger Perioperative Opioid Prescriptions Lead to Prolonged Opioid Use After Hand and Upper Extremity Surgery: A Multicenter Analysis.

INTRODUCTION: The opioid epidemic remains an ongoing public health crisis. The purpose of this study was to investigate whether surgeons' prescribing patterns of the initial postoperative opioid prescription predispose patients to prolonged opioid use after upper extremity surgery. METHODS: This multicenter retrospective study was done at three academic institutions. Patients who underwent carpal tunnel release, basal joint arthroplasty, and distal radius fracture open reduction and internal fixation over a 1.5-year period were included. Opioid prescription data were obtained from the Pennsylvania Prescription Drug Monitoring Program website. RESULTS: Postoperatively, 30.1% of the patients (191/634) filled ≥1 additional opioid prescription, and 14.0% (89/634) experienced prolonged opioid use 3 to 6 months postoperatively. Patients who filled an additional prescription postoperatively were initially prescribed significantly more pills (P = 0.001), a significantly longer duration prescription (P = 0.009), and a significantly larger prescription in total milligram morphine equivalents (P = 0.002) than patients who did not fill additional prescriptions. Patients who had prolonged opioid use were prescribed a significantly longer duration prescription (P = 0.026) than those without prolonged use. CONCLUSION: Larger and longer duration of initial opioid prescriptions predisposed patients to continued postoperative opioid use. These findings emphasize the importance of safe and evidence-based prescribing practices to prevent the detrimental effects of opioid use after orthopaedic surgery.

Ten Years of Sports Health: Authorship Characteristics and Levels of Evidence.

CONTEXT: Sports Health: A Multidisciplinary Approach, now 10 years into production, has been ranked a top-25 journal in sport sciences and has tripled its impact throughout its existence. OBJECTIVE: To evaluate authorship trends and levels of evidence (LOE) of articles published in Sports Health from 2009 to 2018. The secondary aim was to analyze funding sources and internationalization throughout the journal's tenure. DATA SOURCES: All clinical studies published in Sports Health between the years 2009 and 2018 were examined. STUDY SELECTION: All publications from the provided years were electronically reviewed by 2 reviewers and evaluated for inclusion criteria. Editorials, society news, memorials, letters to the editor, and corrigenda were excluded. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 5. DATA EXTRACTION: Articles were examined for number of authors, presence of female authorship, funding, country of origin, international collaboration, academic degree or certification of first and senior authors, and LOE. Clinical articles were assigned LOE based on guidelines from the University of Oxford's Centre for Evidence-Based Medicine. RESULTS: A total of 654 articles were examined. The percentage of high-LOE studies increased throughout the study period. The percentage of publications with female authors also increased throughout the study period. The mean number of authors per article increased from 3.2 to 4.6 over the 10-year period (P < 0.05). The percentage of publications with international collaboration stayed consistent, while the number of countries per year increased during the study period. Overall, institutions from 23 countries have published in Sports Health since its inception to the time of this study. CONCLUSION: Female authorship in Sports Health surpasses industry standards, and the percentage of high-LOE studies remains remarkably high. Sports Health has stayed true to its multidisciplinary scope, as evidenced by the authors' varying degrees and numerous countries that publish in the journal.

Level of evidence and authorship trends of clinical studies in knee surgery, sports traumatology, arthroscopy, 1995-2015.

PURPOSE: There is increasing emphasis on publication quality and internationalization of author groups in orthopaedic literature. The purpose of this review was to evaluate the type of studies and the level of evidence (LOE) published in knee surgery, sports traumatology, arthroscopy (KSSTA) from 1995 to 2015. The secondary aim was to analyze trends in authorship characteristics in KSSTA. METHODS: Two reviewers reviewed the table of contents of KSSTA and identified original papers from 1995, 2000, 2005, 2010, and 2015. The reviewers graded LOE from Levels I to IV using guidelines from the University of Oxford's Centre for Evidence-Based Medicine. For each article, the total number of authors and country of author group were also analyzed. RESULTS: A total of 880 papers were analyzed. The proportions in LOE have stayed consistent throughout the study period (n.s.). There has been a significant increase in the number of published articles and the number of Level I and II studies (P < 0.01). Therapeutic articles were the most common type. The mean number of authors per KSSTA article significantly increased from 3.9 to 5.7 over the 20-year period (P < 0.01). The number of represented countries increased yearly and academic institutions from 40 different nationalities published articles in the Journal. Of the examined years, the percent of articles with international collaboration was 17.6%. CONCLUSION: The proportion of LOE I and II articles published in KSSTA remains consistently high. Therapeutic studies are the most frequently published articles. There is an increase in international groups publishing in KSSTA. LEVEL OF EVIDENCE: IV.

Near-infrared operating lamp for intraoperative molecular imaging of a mediastinal tumor.

BACKGROUND: Near-Infrared (NIR) intraoperative molecular imaging is a new diagnostic modality utilized during cancer surgery for the identification of tumors, metastases and lymph nodes. Surgeons typically use headlamps during an operation to increase visible light; however, these light sources are not adapted to function simultaneously with NIR molecular imaging technology. Here, we design a NIR cancelling headlamp and utilize it during surgery to assess whether intraoperative molecular imaging of mediastinal tumors is possible. METHODS: A NIR cancelling headlamp was designed and tested using NIR spectroscopy preoperatively. Next, a 46 year-old-female was referred to the thoracic surgery clinic for a 5.8 cm mediastinal mass noted on chest x-ray. Prior to surgery, she was given intravenous indocyanine green (ICG). Then, the prototype headlamp was used in conjunction with our intraoperative molecular imaging device. The tumor was imaged both in vivo and following resection prior to pathological examination. RESULTS: NIR spectroscopy confirmed NIR light excitation of the unfiltered headlamp and the absence of NIR emitted light after addition of the filter. Next, in vivo imaging confirmed fluorescence of the tumor, but also demonstrated a significant amount of NIR background fluorescence emanating from the unfiltered headlamp. During imaging with the filtered headlamp, we again demonstrated a markedly fluorescent tumor but with a reduced false positive NIR signal. Final pathology was well-differentiated thymoma with negative surgical margins. CONCLUSIONS: NIR intraoperative molecular imaging using a systemic injection of intravenous ICG was successful in localizing a thymoma. Additionally, a simple design and implementation of a NIR cancelling headlamp reduces false positive NIR fluorescence.

Intraoperative Molecular Diagnostic Imaging Can Identify Renal Cell Carcinoma.

PURPOSE: Margin status can often be difficult to assess intraoperatively, particularly during partial nephrectomy given the time constraints related to renal hilar clamping. We hypothesized that a targeted molecular imaging approach could be used during surgery to identify tumor margins and confirm disease clearance. MATERIALS AND METHODS: EC17, a novel tracer targeting FRα, was used in murine models of renal cell carcinoma to identify positive margins after surgery. Positive margins were detected due to elevated tumor-to-background ratios of the tumor compared to surrounding normal tissues. We performed a pilot study in 4 patients using EC17 preoperatively with intraoperative imaging during the operation. RESULTS: FRα was highly expressed in 65% of clear cell renal cell carcinomas harvested from the operating room. In the murine model intraoperative imaging of renal cell carcinoma revealed a mean ± SD tumor-to-background ratio of 8.2 ± 1.1 in the RCC10, 11.2 ± 1.1 in the 786-0 and 4.3 ± 1.1 in the UMRC2 cell line. Compared to visual inspection intraoperative imaging of the surgical resection bed identified residual disease in 24% more animals. In the human pilot study targeted molecular imaging identified 2 of 4 renal cell carcinomas and had no false-positive results. In these 2 cases the tumor-to-background ratio was 3.7 and 4.6, respectively. In each case we confirmed disease clearance and tumor fluorescence did not correlate with nodule size or tumor grade. CONCLUSIONS: To our knowledge this is the first demonstration in humans of identifying renal cell carcinoma during surgery using a targeted molecular contrast agent. This approach may lead to a superior method of identifying malignancy and tumor borders in the intraoperative setting.

Intraoperative Molecular Imaging of Lung Adenocarcinoma Can Identify Residual Tumor Cells at the Surgical Margins.

PURPOSE: During lung surgery, identification of surgical margins is challenging. We hypothesized that molecular imaging with a fluorescent probe to pulmonary adenocarcinomas could enhance residual tumor during resection. PROCEDURES: Mice with flank tumors received a contrast agent targeting folate receptor alpha. Optimal dose and time of injection was established. Margin detection was compared using traditional methods versus molecular imaging. A pilot study was then performed in three humans with lung adenocarcinoma. RESULTS: The peak tumor-to-background ratio (TBR) of murine tumors was 3.9. Fluorescence peaked at 2 h and was not improved beyond 0.1 mg/kg. Traditional inspection identified 30% of mice with positive margins. Molecular imaging identified an additional 50% of residual tumor deposits (p < 0.05). The fluorescent probe visually enhanced all human tumors with a mean TBR of 3.5. CONCLUSIONS: Molecular imaging is an important adjunct to traditional inspection to identify surgical margins after tumor resection.

Quantification of tumor fluorescence during intraoperative optical cancer imaging.

Intraoperative optical cancer imaging is an emerging technology in which surgeons employ fluorophores to visualize tumors, identify tumor-positive margins and lymph nodes containing metastases. This study compares instrumentation to measure tumor fluorescence. Three imaging systems (Spectropen, Glomax, Flocam) measured and quantified fluorescent signal-to-background ratios (SBR) in vitro, murine xenografts, tissue phantoms and clinically. Evaluation criteria included the detection of small changes in fluorescence, sensitivity of signal detection at increasing depths and practicality of use. In vitro, spectroscopy was superior in detecting incremental differences in fluorescence than luminescence and digital imaging (Ln[SBR] = 6.8 ± 0.6, 2.4 ± 0.3, 2.6 ± 0.1, p = 0.0001). In fluorescent tumor cells, digital imaging measured higher SBRs than luminescence (6.1 ± 0.2 vs. 4.3 ± 0.4, p = 0.001). Spectroscopy was more sensitive than luminometry and digital imaging in identifying murine tumor fluorescence (SBR = 41.7 ± 11.5, 5.1 ± 1.8, 4.1 ± 0.9, p = 0.0001), and more sensitive than digital imaging at detecting fluorescence at increasing depths (SBR = 7.0 ± 3.4 vs. 2.4 ± 0.5, p = 0.03). Lastly, digital imaging was the most practical and least time-consuming. All methods detected incremental differences in fluorescence. Spectroscopy was the most sensitive for small changes in fluorescence. Digital imaging was the most practical considering its wide field of view, background noise filtering capability, and sensitivity to increasing depth.

Comparison of Folate Receptor Targeted Optical Contrast Agents for Intraoperative Molecular Imaging.

Background. Intraoperative imaging can identify cancer cells in order to improve resection; thus fluorescent contrast agents have emerged. Our objective was to do a preclinical comparison of two fluorescent dyes, EC17 and OTL38, which both target folate receptor but have different fluorochromes. Materials. HeLa and KB cells lines were used for in vitro and in vivo comparisons of EC17 and OTL38 brightness, sensitivity, pharmacokinetics, and biodistribution. In vivo experiments were then performed in mice. Results. The peak excitation and emission wavelengths of EC17 and OTL38 were 470/520 nm and 774/794 nm, respectively. In vitro, OTL38 required increased incubation time compared to EC17 for maximum fluorescence; however, peak signal-to-background ratio (SBR) was 1.4-fold higher compared to EC17 within 60 minutes (p < 0.001). Additionally, the SBR for detecting smaller quantity of cells was improved with OTL38. In vivo, the mean improvement in SBR of tumors visualized using OTL38 compared to EC17 was 3.3 fold (range 1.48-5.43). Neither dye caused noticeable toxicity in animal studies. Conclusions. In preclinical testing, OTL38 appears to have superior sensitivity and brightness compared to EC17. This coincides with the accepted belief that near infrared (NIR) dyes tend to have less autofluorescence and scattering issues than visible wavelength fluorochromes.

Optimization of the enhanced permeability and retention effect for near-infrared imaging of solid tumors with indocyanine green.

Surgery is the most effective method to cure patients with solid tumors. New techniques in near-infrared (NIR) cancer imaging are being used to identify surgical margins and residual tumor cells in the wound. Our goal was to determine the optimal time and dose for imaging solid tumors using Indocyanine Green. Syngeneic murine flank tumor models were used to test NIR imaging of ICG at various doses ranging from 0 to 10 mg/kg. Imaging was performed immediately after injection and up to 72 hours later. Biodistribution in the blood and murine organs were quantified by spectroscopy and fluorescence microscopy. Based on these results, a six patient dose titration study was performed. In murine flank tumors, the tumor-to-background ratio (TBR) for ICG at doses less than 5 mg/kg were less than 2 fold at all time points, and the surgeons could not subjectively identify tissue contrast. However, for doses ranging from 5 mg/kg to 10 mg/kg, the TBR ranged from 2.1 to 8.0. The tumor signal was best appreciated at 24 hours and the background was least pronounced after 24 hours. Biodistribution studies in the blood and murine organs revealed excretion through the biliary tree and gastrointestinal tract, with minimal blood fluorescence at the higher doses. A follow up pilot study confirmed that these findings were applicable to lung cancer patients, and tumor was clearly delineated from surrounding normal tissue by NIR imaging. For non-hepatic solid tumors, we found ICG was optimal when dosed at 5 mg/kg and 24 hours before surgery.

Intraoperative molecular imaging can identify lung adenocarcinomas during pulmonary resection.

BACKGROUND: More than 80,000 people undergo resection of a pulmonary tumor each year, and the only method to determine if the tumor is malignant is histologic analysis. We propose that a targeted molecular contrast agent could bind lung adenocarcinomas, which could be identified using real-time optical imaging at the time of surgery. METHODS: Fifty patients with a biopsy-proven lung adenocarcinoma were enrolled. Before surgery, patients were systemically administered 0.1 mg/kg of a fluorescent folate receptor alpha (FRα)-targeted molecular contrast agent by intravenous infusion. During surgery, tumors were imaged in situ and ex vivo, after the lung parenchyma was dissected to directly expose the tumor to the imaging system. RESULTS: Tumors ranged from 0.3 to 7.5 cm (mean: 2.6 cm), and 46 of 50 (92%) lung adenocarcinomas were fluorescent. No false uptake occurred, and in 2 cases, intraoperative imaging revealed tumor metastases (3 mm and 6 mm) that were not recognized preoperatively. Four adenocarcinomas were not fluorescent, and immunohistochemistry showed that these adenocarcinomas did not express FRα. Tumor fluorescence was independent of nodule size, uptake of 2-deoxy-2-((18)F)fluoro-D-glucose, histology, and tumor differentiation. Molecular imaging could identify only 7 of the 50 adenocarcinomas in situ in the patient without bisection. The most important predictor of the success of molecular imaging in locating the tumor in situ was the distance of the nodule from the pleural surface. CONCLUSIONS: Intraoperative molecular imaging with a targeted contrast agent can identify lung adenocarcinomas, and this technology is currently useful in patients with subpleural tumors, irrespective of size. With further refinements, this tool may prove useful in locating adenocarcinomas that are deeper in the lung parenchyma, in lymph nodes, and at pleural and resection margins.

Small portable interchangeable imager of fluorescence for fluorescence guided surgery and research.

Fluorescence guided surgery (FGS) is a developing field of surgical and oncologic research. Practically, FGS has shown useful applications in urologic surgery, benign biliary surgery, colorectal cancer liver metastasis resection, and ovarian cancer debulking. Most notably in in cancer surgery, FGS allows for the clear delineation of cancerous tissue from benign tissue. FGS requires the utilization of a fluorescent contrast agent and an intraoperative fluorescence imaging device (IFID). Currently available IFIDs are expensive, unable to work with multiple fluorophores, and can be cumbersome. This study aims to describe the development and utility of a small, cost-efficient, and interchangeable IFID made from commercially available components. Extensive research was done to design and construct a light-weight, portable, and cost-effective IFID. We researched the capabilities, size, and cost of several camera types and eventually decided on a near-infrared (NIR) charged couple device (CCD) camera for its overall profile. The small portable interchangeable imager of fluorescence (SPIIF) is a "scout" IFID system for FGS. The main components of the SPIIF are a NIR CCD camera with an articulating light filter. These components and a LED light source with an attached heat sink are mounted on a small metal platform. The system is connected to a laptop by a USB 2.0 cable. Pixielink © software on the laptop runs the system by controlling exposure time, gain, and image capture. After developing the system, we evaluated its utility as an IFID. The system weighs less than two pounds and can cover a large area. Due to its small size, it is easily made sterile by covering it with any sterile plastic sheet. To determine the system's ability to detect fluorescent signal, we used the SPIIF to detect indocyanine green under ex and in-vivo conditions and fluorescein under ex-vivo conditions. We found the SPIIF was able to detect both ICG and fluorescein under different depths of a semi-opaque colloid. Second, we found that a concentration as low as 0.5 g/ml of indocyanine green dissolved in plasma was detectable. Lastly, in a murine and human cancer model, the SPIIF was able to detect indocyanine green signal within tumors and generate a signal-to-background ratio (SBR) of 3.75. This study shows that a low-cost IFID can be made from commercially available parts. Second, this IFID is capable of in and ex-vivo detection of multiple fluorophores without sacrificing its small size or favorable ergonomics.

Molecular imaging to identify tumor recurrence following chemoradiation in a hostile surgical environment.

Surgical biopsy of potential tumor recurrence is a common challenge facing oncologists, surgeons, and cancer patients. Imaging modalities have limited ability to accurately detect recurrent cancer in fields affected by previous surgery, chemotherapy, or radiation. However, definitive tissue diagnosis is often needed to initiate treatment and to direct therapy. We sought to determine if a targeted fluorescent intraoperative molecular imaging technique could be applied in a clinical setting to assist a surgical biopsy in a "hostile" field. We describe the use of a folate-fluorescein conjugate to direct the biopsy of a suspected recurrent lung adenocarcinoma invading the mediastinum that had been previously treated with chemoradiation. We found that intraoperative imaging allowed the identification of small viable tumor deposits that were otherwise indistinguishable from scar and necrosis. Our operative observations were confirmed by histology, fluorescence microscopy, and immunohistochemistry. Our results demonstrate one possible application and clinical value of intraoperative molecular imaging.

Intraoperative near-infrared imaging can identify pulmonary nodules.

BACKGROUND: Over 80,000 people undergo pulmonary resection for a lung nodule in the United States each year. Small nodules are frequently missed or difficult to find despite preoperative imaging. We hypothesized that near-infrared (NIR) imaging technology could be used to identify and locate lung nodules during surgery. METHODS: We enrolled 18 patients who were diagnosed with a pulmonary nodule that required resection. All patients had a fine-cut 1-mm computed tomography scan preoperatively. The patients were given systemic 5 mg/kg indocyanine green and then underwent an open thoracotomy 24 hours later. The NIR imaging was used to identify the primary nodule and search for additional nodules that were not found by visual inspection or manual palpation of the ipsilateral lung. RESULTS: Manual palpation and visual inspection identified all 18 primary pulmonary nodules and no additional lesions. Intraoperative NIR imaging detected 16 out of the 18 primary nodules. The NIR imaging also identified 5 additional subcentimeter nodules; 3 metastatic adenocarcinomas and 2 metastatic sarcomas. This technology could identify nodules as small as 0.2 cm and as deep as 1.3 cm from the pleural surface. This approach discovered 3 nodules that were in different lobes than the primary tumor. Nodule fluorescence was independent of size, metabolic activity, histology, tumor grade and vascularity. CONCLUSIONS: This is the first-in-human demonstration of identifying pulmonary nodules during thoracic surgery with NIR imaging without a priori knowledge of their location or existence. The NIR imaging can detect pulmonary nodules during lung resections that are poorly visualized on computed tomography and difficult to discriminate on finger palpation.

Intraoperative near-infrared imaging can distinguish cancer from normal tissue but not inflammation.

INTRODUCTION: Defining tumor from non-tumor tissue is one of the major challenges of cancer surgery. Surgeons depend on visual and tactile clues to select which tissues should be removed from a patient. Recently, we and others have hypothesized near-infrared (NIR) imaging can be used during surgery to differentiate tumors from normal tissue. METHODS: We enrolled 8 canines and 5 humans undergoing cancer surgery for NIR imaging. The patients were injected with indocyanine green (ICG), an FDA approved non-receptor specific NIR dye that accumulates in hyperpermeable tissues, 16-24 hours prior to surgery. During surgery, NIR imaging was used to discriminate the tumor from non-tumor tissue. RESULTS: NIR imaging identified all tumors with a mean signal-to-background ratio of 6.7. Optical images were useful during surgery in discriminating normal tissue from cancer. In 3 canine cases and 1 human case, the tissue surrounding the tumor was inflamed due to obstruction of the vascular supply due to mass effect. In these instances, NIR imaging could not distinguish tumor tissue from tissue that was congested, edematous and did not contain cancer. CONCLUSIONS: This study shows that NIR imaging can identify tumors from normal tissues, provides excellent tissue contrast, and it facilitates the resection of tumors. However, in situations where there is significant peritumoral inflammation, NIR imaging with ICG is not helpful. This suggests that non-targeted NIR dyes that accumulate in hyperpermeable tissues will have significant limitations in the future, and receptor-specific NIR dyes may be necessary to overcome this problem.

Adenoviral-based immunotherapy provides local disease control in an orthotopic murine model of esophageal cancer.

Despite recent advances in the development of novel therapies, esophageal carcinoma remains an aggressive cancer associated with a poor prognosis. The lack of a high throughput, reproducible syngeneic animal model that replicates human disease is partly responsible for the paucity of novel therapeutic approaches. In this report, we present the first successful syngeneic, orthotopic model for esophageal cancer. This model was used to test an established adenoviral-based tumor vaccine. We utilized a murine esophageal cancer cell line established from the ED-L2-cyclin D1;p53 mouse that was transduced to express a viral tumor antigen, the Human Papilloma Virus (HPV) E7 protein. The tumor was established in its natural microenvironment at the gastroesophageal junction. Tumor growth was consistent and reproducible. An adenoviral vaccine to E7 (Ad.E7) induced an E7-specific population of functionally active CD8 T cells that trafficked into the tumors and retained cytotoxicity. Ad.E7 vaccination reduced local tumor growth and prolonged overall survival. These findings suggest that orthotopic tumor growth is a reasonable preclinical model to validate novel therapies.