The effect of the alliance on social recovery outcomes and usage in a moderated online social therapy for first-episode psychosis.

OBJECTIVES: We investigated the effect of the therapeutic alliance on both change in social recovery outcomes and usage of a moderated online social therapy platform for first-episode psychosis (FEP), Horyzons. DESIGN: Secondary analysis of a single group pilot trial. METHODS: Clients completed an alliance measure adapted for guided digital interventions at mid-treatment. A series of multi-level models evaluated change in outcomes by mid- and post-treatment assessments (relative to baseline) as a function of the overall alliance. Quasi-Poisson models evaluated the effect of the overall alliance on aggregated counts of platform usage. Exploratory analyses repeated these models in terms of the bond (human-human) or the task/goal (human-program) alliance. RESULTS: Stronger overall alliance at mid-treatment predicted lower loneliness at mid-treatment and lower social anxiety at mid- and post-treatment. It was also associated with higher completion of therapy activities and authoring of comments and reactions. A strong bond with an online therapist was associated with lower loneliness and higher perceived social support at mid-treatment, lower social anxiety at post-treatment as well as a higher number of reactions made on the social network. Stronger alliance with the platform's tasks and goals facilitated lower social anxiety at both follow-up assessments and was further associated with higher completion of therapy activities and reactions in the social network. CONCLUSIONS: The alliance may impact aspects of social recovery and usage in digital interventions for FEP. Specific aspects of the alliance (human-human and human-program relationships) should be considered in future research.

The value of disease-free survival (DFS) and osimertinib in adjuvant non-small-cell lung cancer (NSCLC): an international Delphi consensus report.

BACKGROUND: Rates of disease recurrence and death following surgery remain high in early-stage non-small-cell lung cancer (NSCLC), despite adjuvant treatment and curative intent. Recently, osimertinib showed overwhelming evidence for disease-free survival (DFS), as demonstrated by an overall reduction in the risk of disease recurrence or death in the adjuvant setting of 80% versus control in the ADAURA study (stage IB-IIIA; hazard ratio 0.20; 99.12% confidence interval 0.14-0.30; P < 0.001). However, due to the early unblinding of ADAURA and lack of mature overall survival data, there is a need to qualitatively confirm consensus on the clinical and patient relevance of DFS. MATERIALS AND METHODS: We conducted a modified Delphi panel study consisting of two rounds of surveys, followed by a consensus meeting. An international panel of experts in the field of NSCLC and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) (n = 13) was asked to rate agreement and comment on a list of pre-defined statements covering key consensus gaps. Statements were eliminated or updated between surveys, depending on the level of agreement. A final list of agreed-upon statements was drafted in the consensus meeting. RESULTS: Consensus was reached on 32 qualitative statements, with topics including unmet needs in early-stage NSCLC, the value of DFS, and the value of osimertinib. Crucially, DFS was agreed to be a clinically and patient-relevant endpoint in adjuvant NSCLC. The relevance of DFS was found to relate to the ability of an adjuvant therapy, such as osimertinib, to keep patients in the clinically valuable curative intent setting, while preventing the burden associated with distant and locoregional recurrence, and progressive disease. CONCLUSIONS: Addressing the need for measures that reflect clinical benefit is essential to continue improving outcomes for NSCLC patients. To that end, this work provides a qualitative framework for clinicians to consider the clinical and patient relevance of DFS in adjuvant NSCLC and the benefit demonstrated in ADAURA thus far.

Wnt/ß-catenin activation and macrophage induction during liver cancer development following steatosis.

Obesity confers an independent risk for carcinogenesis. In the liver, steatosis often proceeds cancer formation; however, the mechanisms by which steatosis promotes carcinogenesis is unknown. We hypothesize that steatosis alters the microenvironment to promote proliferation of tumor initiating cells (TICs) and carcinogenesis. We used several liver cancer models to address the mechanisms underlying the role of obesity in cancer and verified these findings in patient populations. Using bioinformatics analysis and verified by biochemical assays, we identified that hepatosteatosis resulting from either Pten deletion or transgenic expression of HCV core/NS5A proteins, promotes the activation of Wnt/ß-catenin. We verified that high fat diet lipid accumulation is also capable of inducing Wnt/ß-catenin. Caloric restriction inhibits hepatosteatosis, reduces Wnt/ß-catenin activation and blocks the expansion of TICs leading to complete inhibition of tumorigenesis without affecting the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) loss regulated protein kinase B (AKT) activation. Pharmacological inhibition or loss of the Wnt/ß-catenin signal represses TIC growth in vitro, and decreases the accumulation of TICs in vivo. In human liver cancers, ontology analysis of gene set enrichment analysis (GSEA)-defined Wnt signature genes indicates that Wnt signaling is significantly induced in tumor samples compared with healthy livers. Indeed, Wnt signature genes predict 90% of tumors in a cohort of 558 patient samples. Selective depletion of macrophages leads to reduction of Wnt and suppresses tumor development, suggesting infiltrating macrophages as a key source for steatosis-induced Wnt expression. These data established Wnt/ß-catenin as a novel signal produced by infiltrating macrophages induced by steatosis that promotes growth of tumor progenitor cells, underlying the increased risk of liver tumor development in obese individuals.

Gene Microarray Analyses of Daboia russelli russelli Daboiatoxin Treatment of THP-1 Human Macrophages Infected with Burkholderia pseudomallei.

Burkholderia pseudomallei is the causative agent of melioidosis and represents a potential bioterrorism threat. In this study, the transcriptomic responses of B. pseudomallei infection of a human macrophage cell model were investigated using whole-genome microarrays. Gene expression profiles were compared between infected THP-1 human monocytic leukemia cells with or without treatment with Daboia russelli russelli daboiatoxin (DRRDbTx) or ceftazidime (antibiotic control). Microarray analyses of infected and treated cells revealed differential upregulation of various inflammatory genes such as interleukin-1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-α), cyclooxygenase (COX-2), vascular endothelial growth factor (VEGF), chemokine C-X-C motif ligand 4 (CXCL4), transcription factor p65 (NF-kB); and several genes involved in immune and stress responses, cell cycle, and lipid metabolism. Moreover, following DRR-DbTx treatment of infected cells, there was enhanced expression of the tolllike receptor 2 (TLR-2) mediated signaling pathway involved in recognition and initiation of acute inflammatory responses. Importantly, we observed that highly inflammatory cytokine gene responses were similar in infected cells exposed to DRR-DbTx or ceftazidime after 24 h. Additionally, there were increased transcripts associated with cell death by caspase activation that can promote host tissue injury. In summary, the transcriptional responses during B. pseudomallei infection of macrophages highlight a broad range of innate immune mechanisms that are activated within 24 h post-infection. These data provide insights into the transcriptomic kinetics following DRR-DbTx treatment of human macrophages infected with B. pseudomallei.

Spectral properties of Titan's impact craters imply chemical weathering of its surface.

We examined the spectral properties of a selection of Titan's impact craters that represent a range of degradation states. The most degraded craters have rims and ejecta blankets with spectral characteristics that suggest that they are more enriched in water ice than the rims and ejecta blankets of the freshest craters on Titan. The progression is consistent with the chemical weathering of Titan's surface. We propose an evolutionary sequence such that Titan's craters expose an intimate mixture of water ice and organic materials, and chemical weathering by methane rainfall removes the soluble organic materials, leaving the insoluble organics and water ice behind. These observations support the idea that fluvial processes are active in Titan's equatorial regions.

GRP78 as a regulator of liver steatosis and cancer progression mediated by loss of the tumor suppressor PTEN.

Glucose-regulated protein 78 (GRP78), a molecular chaperone widely elevated in human cancers, is critical for endoplasmic reticulum (ER) protein folding, stress signaling and PI3K/AKT activation. Genetic knockout models of GRP78 revealed that GRP78 maintains homeostasis of metabolic organs, including liver, pancreas and adipose tissues. Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the most common liver cancers. There is a lack of effective therapeutics for HCC and CC, highlighting the need to further understand liver tumorigenic mechanisms. PTEN (phosphatase and tenson homolog deleted on chromosome 10), a tumor suppressor that antagonizes the PI3K/AKT pathway, is inactivated in a wide range of tumors, including 40-50% of human liver cancers. To elucidate the role of GRP78 in liver cancer, we created a mouse model with biallelic liver-specific deletion of Pten and Grp78 mediated by Albumin-Cre-recombinase (cP(f/f)78(f/f)). Interestingly, in contrast to PTEN, deletion of GRP78 was progressive but incomplete. At 3 months, cP(f/f)78(f/f) livers showed hepatomegaly, activation of lipogenic genes, exacerbated steatosis and liver injury, implying that GRP78 protects the liver against PTEN-null-mediated pathogenesis. Furthermore, in response to liver injury, we observed increased proliferation and expansion of bile duct and liver progenitor cells in cP(f/f)78(f/f) livers. Strikingly, bile duct cells in cP(f/f)78(f/f) livers maintained wild-type (WT) GRP78 level, whereas adjacent areas showed GRP78 reduction. Analysis of signaling pathways revealed selective JNK activation, ß-catenin downregulation, along with PDGFRα upregulation, which was unique to cP(f/f)78(f/f) livers at 6 months. Development of both HCC and CC was accelerated and was evident in cP(f/f)78(f/f) livers at 8-9 months, coinciding with intense GRP78 expression in the cancer lesions, and GRP78 expression in adjacent normal areas reverted back to the WT level. In contrast, c78(f/f) livers showed no malignancy even at 14 months. These studies reveal that GRP78 is a novel regulator for PTEN-loss-mediated liver injury and cancer progression.

Snake venom phospholipases A(2): a novel tool against bacterial diseases.

The majority of snake venom phospholipases A(2) (svPLA(2)s) are toxic and induce a wide spectrum of biological effects. They are cysteine-rich proteins that contain 119-134 amino acids and share similar structures and functions. About 50% of the residues are incorporated into α-helices, whereas only 10% are in ß-sheets. Fourteen conserved cysteines form a network of seven disulfide bridges that stabilize the tertiary structure. They show a high degree of sequence and structural similarity, and are believed to have a common calcium- dependent catalytic mechanism. Additionally, svPLA(2)s display an array of biological actions that are either dependent or independent of catalysis. The PLA(2)s of mammalian origin also exert potent bactericidal activity by binding to anionic surfaces and enzymatic degradation of phospholipids in the target membranes, preferentially of Gram-positive species. The bactericidal activity against Gram-negatives by svPLA(2) requires a synergistic action with bactericidal/permeability-increasing protein (BPI), but is equally dependent on enzymatic- based membrane degradation. Several hypotheses account for the bactericidal properties of svPLA(2)s, which include "fatal depolarization" of the bacterial membrane, creation of physical holes in the membrane, scrambling of normal distribution of lipids between the bilayer leaflets, and damage of critical intracellular targets after internalization of the peptide. The present review discusses several svPLA(2)s and derived peptides that exhibit strong bactericidal activity. The reports demonstrate that svPLA(2)-derived peptides have the potential to counteract microbial infections. In fact, the C-terminal cationic/hydrophobic segment (residues 115-129) of svPLA(2)s is bactericidal. Thus identification of the bactericidal sites in svPLA(2)s has potential for developing novel antimicrobials.

Molecular network pathways and functional analysis of tumor signatures associated with development of resistance to viral gene therapy.

Replication-competent attenuated herpes simplex viruses have proven effective in killing many cancer cell lines. However, determinants of resistance to oncolytic therapy are mostly unknown. We developed viral therapy-resistant cells and examined changes in gene-expression pattern compared with therapy-sensitive parental cells. Colon cancer cell line HT29 and hepatoma cell line PLC5 were exposed to increasing concentrations of virus G207. Therapy-resistant cells were isolated and grown in vitro. Tumorigenicity was confirmed by ability of cell lines to form tumors in mice. Human Genome U133A complementary DNA microarray chips were used to determine gene-expression patterns, which were analyzed in the context of molecular network interactions, pathways and gene ontology. In parental cell lines, 90-100% of cells were killed by day 7 at 1.0 multiplicity of infection. In resistant cell lines, cytotoxicity assay confirmed 200- to 400-fold resistance. Microarray analysis confirmed changes in gene expressions associated with resistance: cell surface proteins affecting viral attachment and entry, cellular proteins affecting nucleotide pools and proteins altering apoptotic pathways. These changes would decrease viral infection and replication. Our study identifies gene-expression signatures associated with resistance to oncolytic viral therapy. These data provide potential targets to overcome resistance, and suggest that molecular assays may be useful in selecting patients for trial with this novel treatment.

miR-200b restoration and DNA methyltransferase inhibitor block lung metastasis of mesenchymal-phenotype hepatocellular carcinoma.

Epithelial-to-mesenchymal transition (EMT) is associated with poor prognosis and metastasis in hepatocellular carcinoma. We have previously demonstrated an in vivo model of liver cancer in which mesenchymal cells post-EMT demonstrate a high rate of invasive growth and metastasis. Here, we investigate the role of microRNA 200 (miR-200) family members and epigenetic modifications on the maintenance of mesenchymal/metastatic phenotype after EMT. Mesenchymal cells post-EMT demonstrates high levels of E-box repressors Zeb1 and Zeb2 and downregulation of four miR-200 family members (miR-200a, miR-200b, miR-200c and miR-429). In addition, DNA sequencing after bisulfite modification demonstrates that several CpG sites within the E-cadherin promoter are methylated in mesenchymal cells. In mesenchymal cells, forced expression of miR-200b results in a significant increase in E-cadherin and a reduction in cell migration/invasion. Despite these mesenchymal-to-epithelial transition (MET) changes in vitro, there is no significant change in metastatic potential after miR-200b upregulation in vivo. After the mesenchymal cells were treated with combination of DNA methyltransferase (DNMT) inhibitor and upregulation of miR-200b, invasive phenotype was significantly reduced and metastatic potential was eliminated. Direct targeting of E-cadherin with short hairpin RNA does not restore metastatic potential after DNMT inhibition and miR-200b re-expression. In addition, restoration of E-cadherin alone was unable to block metastatic potential in primary mesenchymal cells. In conclusion, targeting mesenchymal liver cancer cells with miR-200b and DNMT inhibitor reduces metastatic potential irrespective of E-cadherin expression. Thus, the broader differentiation and MET effects of DNMT inhibition and miR-200b must be considered in terms of rescuing metastatic potential.

Antimicrobial proteins from snake venoms: direct bacterial damage and activation of innate immunity against Staphylococcus aureus skin infection.

The innate immune system is the first line of defense against microbial diseases. Antimicrobial proteins produced by snake venoms have recently attracted significant attention due to their relevance to bacterial infection and potential development into new therapeutic agents. Staphylococcus aureus is one of the major human pathogens causing a variety of infections involving pneumonia, toxic shock syndrome, and skin lesions. With the recent emergence of methicillin (MRSA) and vancomycin (VRSA) resistance, S. aureus infection is a serious clinical problem that will have a grave socio-economic impact in the near future. Although S. aureus susceptibility to innate antimicrobial peptides has been reported recently, the protective effect of snake venom phospholipase A2 (svPLA2) proteins on the skin from S. aureus infection has been understudied. This review details the protective function of svPLA2s derived from venoms against skin infections caused by S. aureus. We have demonstrated in vivo that local application of svPLA2 provides complete clearance of S. aureus within 2 weeks after treatment compared to fusidic acid ointment (FAO). In vitro experiments also demonstrate that svPLA2 proteins have inhibitory (bacteriostatic) and killing (bactericidal) effects on S. aureus in a dose-dependant manner. The mechanism of bacterial membrane damage and perturbation was clearly evidenced by electron microscopic studies. In summary, svPLA2s from Viperidae and Elapidae snakes are novel molecules that can activate important mechanisms of innate immunity in animals to endow them with protection against skin infection caused by S. aureus.

Staphylococcus aureus: the toxic presence of a pathogen extraordinaire.

Staphylococcus aureus is a facultative, Gram-positive coccus well known for its disease-causing capabilities. In particular, methicillin and vancomycin resistant strains of S. aureus (MRSA and VRSA, respectively) isolated globally represent daunting medical challenges for the 21(st) Century. This bacterium causes numerous illnesses in humans such as food poisoning, skin infections, osteomyelitis, endocarditis, pneumonia, enterocolitis, toxic shock, and autoimmune disorders. A few of the many virulence factors attributed to S. aureus include antibiotic resistance, capsule, coagulase, lipase, hyaluronidase, protein A, fibronectin-binding protein, and multiple toxins with diverse activities. One family of protein toxins is the staphylococcal enterotoxins (SEs) and related toxic shock syndrome toxin-1 (TSST-1) that act as superantigens. There are more than twenty different SEs described to date with varying amino acid sequences, common conformations, and similar biological effects. By definition, very low (picomolar) concentrations of these superantigenic toxins activate specific T-cell subsets after binding to major histocompatibility complex class II. Activated T-cells vigorously proliferate and release proinflammatory cytokines plus chemokines that can elicit fever, hypotension, and other ailments which include a potentially lethal shock. In vitro and in vivo models are available for studying the SEs and TSST-1, thus providing important tools for understanding modes of action and subsequently countering these toxins via experimental vaccines or therapeutics. This review succinctly presents the pathogenic ways of S. aureus, with a toxic twist. There will be a particular focus upon the biological and biochemical properties of, plus current neutralization strategies targeting, staphylcoccocal superantigens like the SEs and TSST-1.

Surgical management of chylothorax.

BACKGROUND: Chylothorax remains an uncommon but challenging clinical problem. Thoracic duct ligation is the treatment of choice for postsurgical patients. However, the optimal treatment for traumatic patients is unclear. We wanted to examine the outcomes of patients with high output or recurrent chylothorax who were treated by surgical means. METHODS: From December 1992 to April 2008, 29 patients underwent surgical procedures for high output (> 1 L/day) (16) or recurrent chylothorax (13). We analyzed these patients to determine the surgical approach, perioperative complications, and outcomes of the treatment approach. RESULTS: Of the 29 patients, 12 patients developed chylothorax following esophagectomy, in 5 patients it resulted from lymphoproliferative disorders, in 2 patients following ascending aneurysm repair, in 2 after trauma, in 3 following lung resection, and in 1 patient respectively from coronary artery bypass grafting (CABG), thymectomy for thymoma, vasculitis, and metastatic lung cancer, while 1 patient had no clear etiology. The median age of patients was 61 (range 20-79) years. 22 patients initially underwent thoracic duct ligation, 6 had talc pleurodesis, and one underwent bilateral pleuroperitoneal shunt placement. Approaches for thoracic duct ligation included: right thoracotomy (16), left thoracotomy (3), VATS (2), and right thoracotomy together with laparotomy (1). There were no intraoperative complications or deaths within 30 days or during postoperative hospitalization. The success rate after initial thoracic duct ligation was 95 % (21/22). One patient needed re-exploration after ligation with resolution of chylothorax after the second operation. The success rate after pleurodesis was 83 % (5/6). One patient after pleurodesis needed subsequent thoracic duct ligation for resolution of bilateral chylothoraces. All patients in this series had resolution of chylothorax. CONCLUSIONS: Thoracic duct ligation is the treatment of choice for high output or recurrent chylothorax with a 96 % success rate. Surgical pleurodesis is effective in some cases and may be an option for marginal patients.

Morning report: combining education with patient handover.

INTRODUCTION: The advent of resident work hour restrictions has challenged us to train residents within a shorter working week, while ensuring continuity of patient care. We instituted morning report (MR) at the University of Virginia primarily as a means to accomplish these objectives. Serendipitously MR has become an integral educational tool for the surgical residents. The rationale for the format and instructional design are discussed in the context of learning theory. METHODS: The chief residents as primary stakeholders were strongly encouraged to play a leadership role in designing MR. A faculty- led didactic format was rejected because of the importance of focusing on resident team building, and leadership, but poor faculty participation was also an issue. RESULTS: The initial obstacles included timing, and designing the format. CONCLUSIONS: MR is an opportunity for residents to exercise and improve their knowledge, leadership, presentation and problem-solving skills. We would hypothesise that the advantages for teaching are many and include that residents are prepared for actual clinical problems in a supportive environment with opportunities for immediate feedback and assessment. Reports of educational effectiveness of MR are mostly anecdotal and further studies are needed to characterise the types of learning and teaching that occur during MR and to document educational effectiveness.

Cytokine-secreting herpes viral mutants effectively treat tumor in a murine metastatic colorectal liver model by oncolytic and T-cell-dependent mechanisms.

In this model of hepatic micrometastases, the antitumor efficacy and role of the T-cell and natural killer (NK) cell populations were studied for oncolytic herpes simplex virus type-1 (HSV-1) viral mutants containing the granulocyte-monocyte colony stimulating factor (GM-CSF (NV1034)) or interluken-12 (IL-12 (NV1042)) cytokine genes. These were compared to saline and control virus (NV1023) in vitro and in vivo. HSV-1 mutants were assessed for cytotoxicity, replication and cytokine expression in CT-26 cells. A syngeneic micrometastatic liver model was then established in naive and immune cell-depleted animals to assess the antitumor efficacy of these viruses. In vitro cytotoxicity and viral replication were similar for each virus, resulting in greater than 80 and 98% cytotoxicity at multiplicity of infection of 1 and 10, respectively. Peak viral titers were 25- to 50-fold higher than initial titer and were not significantly different between viruses. In vivo, all three viruses reduced metastases relative to control, but cytokine-secreting viruses did so with greater efficacy compared to NV1023. This effect was abrogated by T-cell depletion, but not NK-cell depletion. Single-agent therapy with oncolytic viral agents containing GM-CSF or IL-12 is effective in a murine model of liver metastases and likely involves direct viral oncolysis and actions of specific immune effector cells.

The lakes of Titan.

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.

Fluorescent cholangiography in a mouse model: an innovative method for improved laparoscopic identification of the biliary anatomy.

BACKGROUND: Real-time imaging of the biliary anatomy may facilitate safe and timely completion of laparoscopic cholecystectomy. This study sought to determine whether the unique autofluorescent properties of bile could facilitate intraoperative identification of the biliary anatomy in mice using fluorescent cholangiography. METHODS: Fluorimetry was performed on samples of mouse bile to determine excitation and emission spectra. For seven mice, chevron laparotomy was performed, followed by liver retraction to expose the porta hepatis. Using stereomicroscopy, photographs were taken in brightfield and fluorescent modes without a change in depth or focus. Six surgical residents evaluated the pictures and identified the gallbladder, cystic duct, common bile duct, and whether the cystic duct joined the right hepatic duct or the common bile duct. RESULTS: Fluorimetry demonstrated autofluorescence of bile at an excitation wavelength of 475 nm. Intense emission was observed at 480 nm. At these settings, fluorescent stereomicroscopy easily identified the gallbladder and biliary tree in mice. This technique decreased diagnostic errors of the biliary anatomy 11-fold (2% vs 22%; p < 0.01), as compared with brightfield visualization. Fluorescent stereomicroscopy also was used to diagnose bile leak, obstruction, and complex anatomy. Using a prototype 5-mm laparoscope equipped with fluorescent filters, the results were reproduced. CONCLUSIONS: Fluorescent cholangiography based solely on the autofluorescence of bile may facilitate real-time identification of the biliary anatomy during laparoscopic procedures, without the need for extraneous dye administration or the use of radiography. This technique has the potential to decrease the rate of iatrogenic biliary tract injuries during laparoscopic cholecystectomy.

Titan Radar Mapper observations from Cassini's T3 fly-by.

Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be longitudinal dunes. Here we describe this great diversity of landforms. We conclude that much of the surface thus far imaged by radar of the haze-shrouded Titan is very young, with persistent geologic activity.

The sand seas of Titan: Cassini RADAR observations of longitudinal dunes.

The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show approximately 100-meter ridges consistent with duneforms and reveal flow interactions with underlying hills. The distribution and orientation of the dunes support a model of fluctuating surface winds of approximately 0.5 meter per second resulting from the combination of an eastward flow with a variable tidal wind. The existence of dunes also requires geological processes that create sand-sized (100- to 300-micrometer) particulates and a lack of persistent equatorial surface liquids to act as sand traps.

Virally-directed fluorescent imaging (VFI) can facilitate endoscopic staging.

BACKGROUND: Replication-competent, tumor specific herpes simplex virus NV1066 expresses green fluorescent protein (GFP) in infected cancer cells. We sought to determine the feasibility of GFP-guided imaging technology in the intraoperative detection of small tumor nodules. METHODS: Human cancer cell lines were infected with NV1066 at multiplicities of infection of 0.01, 0.1 and 1. Cancer cell specific infectivity, vector spread and GFP signal intensity were measured by flow cytometry and time-lapse digital imaging (in vitro); and by use of a stereomicroscope and endoscope equipped with a fluorescent filter (in vivo). RESULTS: NV1066 infected all cancer cell lines and expressed GFP at all MOIs. GFP signal was significantly higher than the autofluorescence of normal cells. One single dose of NV1066 spread within and across body cavities and selectively infected tumor nodules sparing normal tissue. Tumor nodules undetectable by conventional thoracoscopy and laparoscopy were identified by GFP fluorescence. CONCLUSION: Virally-directed fluorescent imaging (VFI) is a real-time novel molecular imaging technology that has the potential to enhance the intraoperative detection of endoluminal or endocavitary tumor nodules.

Minimally invasive localization of oncolytic herpes simplex viral therapy of metastatic pleural cancer.

Herpes simplex virus-1 (HSV-1) oncolytic therapy and gene therapy are promising treatment modalities against cancer. NV1066, one such HSV-1 virus, carries a marker gene for enhanced green fluorescent protein (EGFP). The purpose of this study was to determine whether NV1066 is cytotoxic to lung cancer and whether EGFP is a detectable marker of viral infection in vitro and in vivo. We further investigated whether EGFP expression in infected cells can be used to localize the virus and to identify small metastatic tumor foci (<1 mm) in vivo by means of minimally invasive endoscopic systems equipped with fluorescent filters. In A549 human lung cancer cells, in vitro viral replication was determined by plaque assay, cell kill by LDH release assay, and EGFP expression by flow cytometry. In vivo, A549 cells were injected into the pleural cavity of athymic mice. Mice were treated with intrapleural injection of NV1066 or saline and examined for EGFP expression in tumor deposits using a stereomicroscope or a fluorescent thoracoscopic system. NV1066 replicated in, expressed EGFP in infected cells and killed tumor cells in vitro. In vivo, treatment with intrapleural NV1066 decreased pleural disease burden, as measured by chest wall nodule counts and organ weights. EGFP was easily visualized in tumor deposits, including microscopic foci, by fluorescent thoracoscopy. NV1066 has significant oncolytic activity against a human NSCLC cell line and is effective in limiting the progression of metastatic disease in an in vivo orthotopic model. By incorporating fluorescent filters into endoscopic systems, a minimally invasive means for diagnosing small metastatic pleural deposits and localization of viral therapy for thoracic malignancies may be developed using the EGFP marker gene inserted in oncolytic herpes simplex viruses.