[Navigated liver surgery : Current state and importance in the future]

The preoperative computer-assisted resection planning is the basis for every navigation. Thanks to modern algorithms, the prerequisites have been created to carry out a virtual resection planning and a risk analysis. Thus, individual segment resections can be precisely planned in any conceivable combination. The transfer of planning information and resection suggestions to the operating theater is still problematic. The so-called stereotactic liver navigation supports the exact intraoperative implementation of the planned resection strategy and provides the surgeon with real-time three-dimensional information on resection margins and critical structures during the resection. This is made possible by a surgical navigation system that measures the position of surgical instruments and then presents them together with the preoperative surgical planning data. Although surgical navigation systems have been indispensable in neurosurgery and spinal surgery for many years, these procedures have not yet become established as standard in liver surgery. This is mainly due to the technical challenge of navigating a moving organ. As the liver is constantly moving and deforming during surgery due to respiration and surgical manipulation, the surgical navigation system must be able to measure these alterations in order to adapt the preoperative navigation data to the current situation. Despite these advances, further developments are required until navigated liver resection enters clinical routine; however, it is already clear that laparoscopic liver surgery and robotic surgery will benefit most from navigation technology.

Optimization of off-axis electron holography performed with femtosecond electron pulses

We report on electron holography experiments performed with femtosecond electron pulses in an ultrafast coherent Transmission Electron Microscope based on a laser-driven cold field emission gun. We first discuss the experimental requirements related to the long acquisition times imposed by the low emission/probe current available in these instruments. The experimental parameters are first optimized and electron holograms are then acquired in vacuum and on a nano-object showing that useful physical properties can nevertheless be extracted from the hologram phase in pulsed condition. Finally, we show that the acquisition of short exposure time holograms assembled in a stack, combined with a computer-assisted shift compensation of usual instabilities encountered in holography, such as beam and biprism wire instabilities, can yield electron holograms acquired with a much better contrast paving the way to ultrafast time-resolved electron holography.

Systematic Generation of Patient-Derived Tumor Models in Pancreatic Cancer

In highly aggressive malignancies like pancreatic cancer (PC), patient-derived tumor models can serve as disease-relevant models to understand disease-related biology as well as to guide clinical decision-making. In this study, we describe a two-step protocol allowing systematic establishment of patient-derived primary cultures from PC patient tumors. Initial xenotransplantation of surgically resected patient tumors (n = 134) into immunodeficient mice allows for efficient in vivo expansion of vital tumor cells and successful tumor expansion in 38% of patient tumors (51/134). Expansion xenografts closely recapitulate the histoarchitecture of their matching patients' primary tumors. Digestion of xenograft tumors and subsequent in vitro cultivation resulted in the successful generation of semi-adherent PC cultures of pure epithelial cell origin in 43.1% of the cases. The established primary cultures include diverse pathological types of PC: Pancreatic ductal adenocarcinoma (86.3%, 19/22), adenosquamous carcinoma (9.1%, 2/22) and ductal adenocarcinoma with oncocytic IPMN (4.5%, 1/22). We here provide a protocol to establish quality-controlled PC patient-derived primary cell cultures from heterogeneous PC patient tumors. In vitro preclinical models provide the basis for the identification and preclinical assessment of novel therapeutic opportunities targeting pancreatic cancer.

Bloodstream infections with vancomycin-resistant enterococci are associated with a decreased survival in patients with hematological diseases

Enterococcus species are commensals of the human gastrointestinal tract with the ability to cause invasive infections. For patients with hematological diseases, enterococcal bloodstream infections (BSI) constitute a serious clinical complication which may even be aggravated if the pathogen is vancomycin-resistant. Therefore, we analyzed the course of BSI due to vancomycin-susceptible enterococci (VSE) in comparison to vancomycin-resistant enterococci (VRE) on patient survival. In this retrospective single-center study, BSI were caused by VRE in 47 patients and by VSE in 43 patients. Baseline patient characteristics were similar in both groups. Concerning infection-related characteristics, an increased CRP value and an increased rate of prior colonization with multidrug-resistant organisms were detected in the VRE BSI group. More enterococcal invasive infections were found in the VSE group. The primary endpoint, overall survival (OS) at 30 days after BSI, was significantly lower in patients with VRE BSI compared to patients with VSE BSI (74.5% vs. 90.7%, p = 0.039). In a multivariate regression analysis, VRE BSI and a Charlson comorbidity index higher than 4 were independent factors associated with 30-day mortality. Moreover, we found that VRE with an additional teicoplanin resistance showed a trend towards an even lower OS.

Marie M, Stickney K, VanBuecken D, Vellek B, Webber C, Allen L, Bollyk J, Hilderman N, Ismail H, Lamola S, Sanda S, Vendettuoli H, Tridgell D, Monzavi R, Bock M, Fisher L, Halvorson M, Jeandron D, Kim M, Wood J, Geffner M, Kaufman F, Parkman R, Salazar C, Goland R, Clynes R, Cook S, Freeby M, Gallagher MP, Gandica R, Greenberg E, Kurland A, Pollak S, Wolk A, Chan M, Koplimae L, Levine E, Smith K, Trast J, DiMeglio L, Blum J, Evans-Molina C, Hufferd R, Jagielo B, Kruse C, Patrick V, Rigby M, Spall M, Swinney K, Terrell J, Christner L, Ford L, Lynch S, Menendez M, Merrill P, Pescovitz M, Rodriguez H, Alleyn C, Baidal D, Fay S, Gaglia J, Resnick B, Szubowicz S, Weir G, Benjamin R, Conboy D, deManbey A, Jackson R, Jalahej H, Orban T, Ricker A, Wolfsdorf J, Zhang HH, Wilson D, Aye T, Baker B, Barahona K, Buckingham B, Esrey K, Esrey T, Fathman G, Snyder R, Aneja B, Chatav M, Espinoza O, Frank E, Liu J, Perry J, Pyle R, Rigby A, Riley K, Soto A, Gitelman S, Adi S, Anderson M, Berhel A, Breen K, Fraser K, Gerard-Gonzalez A, Jossan P, Lustig R, Moassesfar S, Mugg A, Ng D, Prahalod P, Rangel-Lugo M, Sanda S, Tarkoff J, Torok C, Wesch R, Aslan I, Buchanan J, Cordier J, Hamilton C, Hawkins L, Ho T, Jain A, Ko K, Lee T, Phelps S, Rosenthal S, Sahakitrungruang T, Stehl L, Taylor L, Wertz M, Wong J, Philipson L, Briars R, Devine N, Littlejohn E, Grant T, Gottlieb P, Klingensmith G, Steck A, Alkanani A, Bautista K, Bedoy R, Blau A, Burke B, Cory L, Dang M, Fitzgerald-Miller L, Fouts A, Gage V, Garg S, Gesauldo P, Gutin R, Hayes C, Hoffman M, Ketchum K, Logsden-Sackett N, Maahs D, Messer L, Meyers L, Michels A, Peacock S, Rewers M, Rodriguez P, Sepulbeda F, Sippl R, Steck A, Taki I, Tran BK, Tran T, Wadwa RP, Zeitler P, Barker J, Barry S, Birks L, Bomsburger L, Bookert T, Briggs L, Burdick P, Cabrera R, Chase P, Cobry E, Conley A, Cook G, Daniels J, DiDomenico D, Eckert J, Ehler A, Eisenbarth G, Fain P, Fiallo-Scharer R, Frank N, Goettle H, Haarhues M, Harris S, Horton L, Hutton J, Jeffrrey J, Jenison R, Jones K, Kastelic W, King MA, Lehr D, Lungaro J, Mason K, Maurer H, Nguyen L, Proto A, Realsen J, Schmitt K, Schwartz M, Skovgaard S, Smith J, Vanderwel B, Voelmle M, Wagner R, Wallace A, Walravens P, Weiner L, Westerhoff B, Westfall E, Widmer K, Wright H, Schatz D, Abraham A, Atkinson M, Cintron M, Clare-Salzler M, Ferguson J, Haller M, Hosford J, Mancini D, Rohrs H, Silverstein J, Thomas J, Winter W, Cole G, Cook R, Coy R, Hicks E, Lewis N, Marks J, Pugliese A, Blaschke C, Matheson D, Sanders-Branca N, Sosenko J, Arazo L, Arce R, Cisneros M, Sabbag S, Moran A, Gibson C, Fife B, Hering B, Kwong C, Leschyshyn J, Nathan B, Pappenfus B, Street A, Boes MA, Eck SP, Finney L, Fischer TA, Martin A, Muzamhindo CJ, Rhodes M, Smith J, Wagner J, Wood B, Becker D, Delallo K, Diaz A, Elnyczky B, Libman I, Pasek B, Riley K, Trucco M, Copemen B, Gwynn D, Toledo F, Rodriguez H, Bollepalli S, Diamond F, Eyth E, Henson D, Lenz A, Shulman D, Raskin P, Adhikari S, Dickson B, Dunnigan E, Lingvay I, Pruneda L, Ramos-Roman M, Raskin P, Rhee C, Richard J, Siegelman M, Sturges D, Sumpter K, White P, Alford M, Arthur J, Aviles-Santa ML, Cordova E, Davis R, Fernandez S, Fordan S, Hardin T, Jacobs A, Kaloyanova P, Lukacova-Zib I, Mirfakhraee S, Mohan A, Noto H, Smith O, Torres N, Wherrett D, Balmer D, Eisel L, Kovalakovska R, Mehan M, Sultan F, Ahenkorah B, Cevallos J, Razack N, Ricci MJ, Rhode A, Srikandarajah M, Steger R, Russell WE, Black M, Brendle F, Brown A, Moore D, Pittel E, Robertson A, Shannon A, Thomas JW, Herold K, Feldman L, Sherwin R, Tamborlane W, Weinzimer S, Toppari J, Kallio T, Kärkkäinen M, Mäntymäki E, Niininen T, Nurmi B, Rajala P, Romo M, Suomenrinne S, Näntö-Salonen K, Simell O, Simell T, Bosi E, Battaglia M, Bianconi E, Bonfanti R, Grogan P, Laurenzi A, Martinenghi S, Meschi F, Pastore M, Falqui L, Muscato MT, Viscardi M, Castleden H, Farthing N, Loud S, Matthews C, McGhee J, Morgan A, Pollitt J, Elliot-Jones R, Wheaton C, Knip M, Siljander H, Suomalainen H, Colman P, Healy F, Mesfin S, Redl L, Wentworth J, Willis J, Farley M, Harrison L, Perry C, Williams F, Mayo A, Paxton J, Thompson V, Volin L, Fenton C, Carr L, Lemon E, Swank M, Luidens M, Salgam M, Sharma V, Schade D, King C, Carano R, Heiden J, Means N, Holman L, Thomas I, Madrigal D, Muth T, Martin C, Plunkett C, Ramm C, Auchus R, Lane W, Avots E, Buford M, Hale C, Hoyle J, Lane B, Muir A, Shuler S, Raviele N, Ivie E, Jenkins M, Lindsley K, Hansen I, Fadoju D, Felner E, Bode B, Hosey R, Sax J, Jefferies C, Mannering S, Prentis R, She J, Stachura M, Hopkins D, Williams J, Steed L, Asatapova E, Nunez S, Knight S, Dixon P, Ching J, Donner T, Longnecker S, Abel K, Arcara K, Blackman S, Clark L, Cooke D, Plotnick L, Levin P, Bromberger L, Klein K, Sadurska K, Allen C, Michaud D, Snodgrass H, Burghen G, Chatha S, Clark C, Silverberg J, Wittmer C, Gardner J, LeBoeuf C, Bell P, McGlore O, Tennet H, Alba N, Carroll M, Baert L, Beaton H, Cordell E, Haynes A, Reed C, Lichter K, McCarthy P, McCarthy S, Monchamp T, Roach J, Manies S, Gunville F, Marosok L, Nelson T, Ackerman K, Rudolph J, Stewart M, McCormick K, May S, Falls T, Barrett T, Dale K, Makusha L, McTernana C, Penny-Thomas K, Sullivan K, Narendran P, Robbie J, Smith D, Christensen R, Koehler B, Royal C, Arthur T, Houser H, Renaldi J, Watsen S, Wu P, Lyons L, House B, Yu J, Holt H, Nation M, Vickers C, Watling R, Heptulla R, Trast J, Agarwal C, Newell D, Katikaneni R, Gardner C, Del Rio A, Logan A, Collier H, Rishton C, Whalley G, Ali A, Ramtoola S, Quattrin T, Mastrandea L, House A, Ecker M, Huang C, Gougeon C, Ho J, Pacuad D, Dunger D, May J, O’Brien C, Acerini C, Salgin B, Thankamony A, Williams R, Buse J, Fuller G, Duclos M, Tricome J, Brown H, Pittard D, Bowlby D, Blue A, Headley T, Bendre S, Lewis K, Sutphin K, Soloranzo C, Puskaric J, Madison H, Rincon M, Carlucci M, Shridharani R, Rusk B, Tessman E, Huffman D, Abrams H, Biederman B, Jones M, Leathers V, Brickman W, Petrie P, Zimmerman D, Howard J, Miller L, Alemzadeh R, Mihailescu D, Melgozza-Walker R, Abdulla N, Boucher-Berry C, Ize-Ludlow D, Levy R, Swenson Brousell C, Scott R, Heenan H, Lunt H, Kendall D, Willis J, Darlow B, Crimmins N, Edler D, Weis T, Schultz C, Rogers D, Latham D, Mawhorter C, Switzer C, Spencer W, Konstantnopoulus P, Broder S, Klein J, Bachrach B, Gardner M, Eichelberger D, Knight L, Szadek L, Welnick G, Thompson B, Hoffman R, Revell A, Cherko J, Carter K, Gilson E, Haines J, Arthur G, Bowen B, Zipf W, Graves P, Lozano R, Seiple D, Spicer K, Chang A, Fregosi J, Harbinson J, Paulson C, Stalters S, Wright P, Zlock D, Freeth A, Victory J, Maheshwari H, Maheshwari A, Holmstrom T, Bueno J, Arguello R, Ahern J, Noreika L, Watson V, Hourse S, Breyer P, Kissel C, Nicholson Y, Pfeifer M, Almazan S, Bajaj J, Quinn M, Funk K, McCance J, Moreno E, Veintimilla R, Wells A, Cook J, Trunnel S, Transue D, Surhigh J, Bezzaire D, Moltz K, Zacharski E, Henske J, Desai S, Frizelis K, Khan F, Sjoberg R, Allen K, Manning P, Hendry G, Taylor B, Jones S, Couch R, Danchak R, Lieberman D, Strader W, Bencomo M, Bailey T, Bedolla L, Roldan C, Moudiotis C, Vaidya B, Anning C, Bunce S, Estcourt S, Folland E, Gordon E, Harrill C, Ireland J, Piper J, Scaife L, Sutton K, Wilkins S, Costelloe M, Palmer J, Casas L, Miller C, Burgard M, Erickson C, Hallanger-Johnson J, Clark P, Taylor W, Galgani J, Banerjee S, Banda C, McEowen D, Kinman R, Lafferty A, Gillett S, Nolan C, Pathak M, Sondrol L, Hjelle T, Hafner S, Kotrba J, Hendrickson R, Cemeroglu A, Symington T, Daniel M, Appiagyei-Dankah Y, Postellon D, Racine M, Kleis L, Barnes K, Godwin S, McCullough H, Shaheen K, Buck G, Noel L, Warren M, Weber S, Parker S, Gillespie I, Nelson B, Frost C, Amrhein J, Moreland E, Hayes A, Peggram J, Aisenberg J, Riordan M, Zasa J, Cummings E, Scott K, Pinto T, Mokashi A, McAssey K, Helden E, Hammond P, Dinning L, Rahman S, Ray S, Dimicri C, Guppy S, Nielsen H, Vogel C, Ariza C, Morales L, Chang Y, Gabbay R, Ambrocio L, Manley L, Nemery R, Charlton W, Smith P, Kerr L, Steindel-Kopp B, Alamaguer M, Tabisola-Nuesca E, Pendersen A, Larson N, Cooper-Olviver H, Chan D, Fitz-Patrick D, Carreira T, Park Y, Ruhaak R, Liljenquist D. A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Timepoints of vancomycin-resistant Enterococcus colonization predict outcomes of acute myeloid leukemia patients undergoing allogeneic hematopoietic cell transplantation

BACKGROUND

In hematology and oncology, in particular in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT), vancomycin-resistant Enterococcus spp. (VRE) colonization rates are high due to previous hospital stays and preceding antibiotic treatment and colonized patients have a lower overall survival (OS).

OBJECTIVE

We reanalyzed our previously published cohort, to unravel which colonization timepoints before and during allo-HSCT might be predictive for the subsequent outcome.

PATIENTS AND METHODS

We report about 268 patients with acute myeloid leukemia receiving an allo-HSCT between 2006 and 2016.

RESULTS

We identified 129 never-colonized patients, 15 previously colonized patients (positive only before admission for allo-HSCT), 41 persistently colonized patients (positive before and at admission for allo-HSCT), and 83 newly colonized patients (positive only during allo-HSCT). Persistently and newly colonized patients had a worse 60 months OS due to increased incidence of non-relapse-related mortality (NRM) than never-colonized patients (OS: never-colonized: 61.0% vs persistently colonized: 43.5%; P = 0.023 vs newly colonized: 45.6%; P = 0.046). In contrast, OS and NRM of never-colonized and previously colonized patients as well as between persistently and newly colonized patients were similar.

CONCLUSION

Patients can lose their VRE colonization status and acquisition of VRE during inpatient stay for allo-HSCT decreases survival to a similar extend as persistent colonization.

Accuracy assessment of a potential clinical use of navigation-guided intra-operative liver metastasis brachytherapy-a planning study

For patients with inoperable liver metastases, intra-operative liver high dose-rate brachytherapy (HDR-BT) is a promising technology enabling delivery of a high radiation dose to the tumor, while sparing healthy tissue. Liver brachytherapy has been described in the literature as safe and effective for the treatment of primary or secondary hepatic malignancies. It is preferred over other ablative techniques for lesions that are either larger than 4 cm or located in close proximity to large vessels or the common bile duct. In contrast to external beam radiation techniques, organ movements do not affect the size of the irradiated volume in intra-operative HDR-BT and new technical solutions exist to support image guidance for intra-operative HDR-BT. We have retrospectively analyzed anonymized CT datasets of 5 patients who underwent open liver surgery (resection and/or ablation) in order to test whether the accuracy of a new image-guidance method specifically adapted for intra-operative HDR-BT is high enough to use it in similar situations and whether patients could potentially benefit from navigation-guided intra-operative needle placement for liver HDR-BT.

Bloodstream infections with gram-negative organisms and the impact of multidrug resistance in patients with hematological malignancies

Infections and especially blood stream infections (BSI) with gram-negative bacteria (GNB) represent a major threat for patients with hematological diseases undergoing chemotherapy and mainly contribute to morbidity and mortality. In this retrospective single-center study, we analyzed the impact of BSI with different gram-negative multidrug-resistant bacteria (MDRGN) compared to BSI with antibiotic susceptible gram-negative bacteria. Data of 109 patients with hematological malignancies and GNB BSI were analyzed with overall survival (OS) 30 days after BSI being the primary endpoint. BSI with non-fermentative gram-negative bacteria were found in 26.6% of all patients and 73.4% suffered from a BSI with an Enterobacteriaceae. Thirty-two of 109 patients suffered from BSI with MDRGN. Characteristics of MDRGN and non-MDRGN BSI patients did not differ besides the fact that significantly more patients received an immunosuppressive therapy in the MDRGN BSI group. OS (30 days after BSI) of patients with MDRGN BSI was significantly lower (85.6 vs. 55.9%; p < 0.001) compared to patients with non-MDRGN BSI. Patients with MDRGN BSI with non-fermentative pathogens had a worse OS after 30 days compared to MDRGN BSI with Enterobacteriaceae and the same holds true for non-MDRGN BSI. In multivariate analysis of MDRGN BSI, non-fermenters and ICU admission were independently associated with increased 30-day mortality. Our data demonstrate the negative impact of non-fermentative gram-negative pathogens causing BSI compared to Enterobacteriaceae in hematological patients and thereby underlining the heterogeneity of gram-negative BSI.

Transorbital Sonography for Early Prognostication of Hypoxic-Ischemic Encephalopathy After Cardiac Arrest

BACKGROUND AND PURPOSE

Early prognostication of the outcome in resuscitated post cardiac arrest (CA) patients remains challenging especially if treated with therapeutic hypothermia. Brain edema caused by hypoxic-ischemic encephalopathy (HIE) can indirectly be estimated by transorbital sonography (TOS) taking in account the optic nerve sheath diameter (ONSD). The prognostic value of this easy, safe, and reproducible technique was investigated in this study.

METHODS

A total of 49 patients, initially unconscious (Glasgow Coma Scale ≤6) after successful resuscitation, were enrolled into this prospective observational study. Sonographic ONSD measurements were performed twice on day of admission (day 0) and once on days 1 and 2 after CA. Beyond ONSD, established prognostic parameters like neuron specific enolase and gray-white matter ratios were assessed. Cerebral Performance Category (CPC) score served as outcome parameter.

RESULTS

A total of 15 (31.3%) patients had a good outcome (CPC-score 1-2), 8 patients (14.6%) had severe disability (CPC-score 3-4), and 26 (54.2%) had a fatal outcome (CPC-score 5). Already in the first measurement on day 0, nonsurvivors showed significantly higher ONSD values (P < .001). For predicting mortality, a threshold of 5.75 mm was calculated with a specificity of 100%. ONSD did not differ significantly depending on hypothermia (P = .7009).

CONCLUSION

Early and reliable prognostication of outcomes in patients with HIE can be simplified by ONSD values gathered with the use of TOS. Main advantages compared to other established markers are prognostication within the first 24 hours and independence from therapy with hypothermia. A higher level of accuracy can be reached by combining computed tomography (gray-to-white matter ratio values) and ONSD values.

Zoonotic origin and transmission of Middle East respiratory syndrome coronavirus in the UAE

Since the emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, there have been a number of clusters of human-to-human transmission. These cases of human-to-human transmission involve close contact and have occurred primarily in healthcare settings, and they are suspected to result from repeated zoonotic introductions. In this study, we sequenced whole MERS-CoV genomes directly from respiratory samples collected from 23 confirmed MERS cases in the United Arab Emirates (UAE). These samples included cases from three nosocomial and three household clusters. The sequences were analysed for changes and relatedness with regard to the collected epidemiological data and other available MERS-CoV genomic data. Sequence analysis supports the epidemiological data within the clusters, and further, suggests that these clusters emerged independently. To understand how and when these clusters emerged, respiratory samples were taken from dromedary camels, a known host of MERS-CoV, in the same geographic regions as the human clusters. Middle East respiratory syndrome coronavirus genomes from six virus-positive animals were sequenced, and these genomes were nearly identical to those found in human patients from corresponding regions. These data demonstrate a genetic link for each of these clusters to a camel and support the hypothesis that human MERS-CoV diversity results from multiple zoonotic introductions.

The role of bradykinin receptor type 2 in spontaneous extravasation in mice skin: implications for non-allergic angio-oedema

BACKGROUND AND PURPOSE

Non-allergic angio-oedema is a life-threatening disease mediated by activation of bradykinin type 2 receptors (B₂ receptors). The aim of this study was to investigate whether activation of B₂ receptors by endogenous bradykinin contributes to physiological extravasation. This may shed new light on the assumption that treatment with an angiotensin converting enzyme inhibitor (ACEi) results in an alteration in the vascular barrier function predisposing to non-allergic angio-oedema.

EXPERIMENTAL APPROACH

We generated a new transgenic mouse model characterized by endothelium-specific overexpression of the B₂ receptor (B2^tg ) and established a non-invasive two-photon laser microscopy approach to measure the kinetics of spontaneous extravasation in vivo. The B2^tg mice showed normal morphology and litter size as compared with their transgene-negative littermates (B2ⁿ ).

KEY RESULTS

Overexpression of B₂ receptors was functional in conductance vessels and resistance vessels as evidenced by B₂ receptor-mediated aortic dilation to bradykinin in presence of non-specific COX inhibitor diclofenac and by significant hypotension in B2^tg respectively. Measurement of dermal extravasation by Miles assay showed that bradykinin induced extravasation was significantly increased in B2^tg as compared with B2ⁿ . However, neither endothelial overexpression of B₂ receptors nor treatment with the ACEi moexipril or B₂ antagonist icatibant had any effect on spontaneous extravasation measured by two-photon laser microscopy.

CONCLUSIONS AND IMPLICATIONS

Activation of B₂ receptors does not appear to be involved in spontaneous extravasation. Therefore, the assumption that treatment with an ACEi results in an alteration in the physiological vascular barrier function predisposing to non-allergic angio-oedema is not supported by our findings.

A Rapid Extraction Method to Quantify Drug Uptake in Contact Lenses

Purpose

To develop a simple extraction procedure to quantify the uptake of four topical ocular pharmaceutical drugs into contact lenses (CLs).

Methods

Four silicone hydrogel (SH) CLs (balafilcon A, senofilcon A, lotrafilcon B, comfilcon B) and four conventional hydrogel (CH) CLs (nesofilcon A, hilafilcon B, nelfilcon A, etafilcon A) were evaluated. The drugs studied were natamycin, moxifloxacin, timolol maleate, and ketotifen fumarate. For drug incubation, three CLs of each type were placed in 1 mL of 1 mg/mL drug-loading solution for 24 hours. The lenses were then extracted in 2 mL methanol for 2 hours. This process was repeated to obtain a total of three extraction cycles. Detection of natamycin, moxifloxacin, ketotifen fumarate, and timolol maleate were measured by absorbance at 305, 287, 297, and 295 nm, respectively.

Results

The majority of the drugs were extracted after the first extraction cycle (P < 0.001). For moxifloxacin and timolol, CH CLs had higher drug uptake than SH CLs (P < 0.05). There were no differences in drug uptake between CH CLs and SH CLs for natamycin and ketotifen (P > 0.05).

Conclusions

This study provides a simple approach to determine drug uptake into CLs. This method can also be modified, such as changing the extraction time, extraction cycles, or extraction solvent to better suit other drugs and CL combinations.

Translational Relevance

There is considerable interest in using CLs for ocular drug delivery. Accurately quantifying drug uptake on CLs has been a challenge. Hence, this study provides a simple method to quantify drug uptake in CLs.

Abstract P3-08-14: Prediction of distant recurrence in low risk early breast cancer by RT-qPCR based subtyping using MammaTyper®

Background:

Estrogen receptor (ER/ESR1), progesterone receptor (PR/PGR) and epidermal growth factor receptor 2 (HER2/ERBB2) are routinely assessed by immunohistochemistry (IHC) during workup of breast cancer samples. The routine use of Ki67 (MKI67) IHC assessment in the context of breast cancer subtyping, however, remains controversial, due to poor reproducibility and lack of standardization.

The MammaTyper® test is an in-vitro diagnostic (IVD) test which measures the expression status of the four breast cancer biomarkers ERBB2, ESR1, PGR and MKI67 on the mRNA level via reverse transcription-quantitative PCR (RT-qPCR) and has demonstrated a high degree of reproducibility in the assessment of the four markers.

In this retrospective analysis we assessed the prognostic power of molecular subtyping by MammaTyper® in archived samples from low risk early breast cancers treated with adjuvant endocrine therapy only.

Methods:

ER+/HER2- (according to initial diagnosis) FFPE breast cancer samples from patients treated with adjuvant endocrine therapy only were obtained from 6 different centers. Tumor cellularity was assessed by H&E staining and RNA was extracted from samples with a tumor cell content of ≥20% using a bead-based RNA purification kit (RNXtract®). Total RNA was then used as input for MammaTyper® RT-qPCR. Expression values were classified as positive or negative for each marker based on predefined cutoff values. Tumor subtypes were assigned to each sample based on the combination of binary (pos/neg) single marker expression status according the St Gallen surrogate subtype definition. Distant disease free survival of Luminal A-like samples vs. samples with other subtypes was assessed by Kaplan Meier analysis and Cox regression using SAS version 9.4.

Results:

The final analysis included 319 samples with sufficient tumor cellularity and RNA content for reliable analysis. The rate of distant recurrence in the analyzed set was 8.5%. Median follow up was 7.8 years. The MammaTyper® test called 60% (192) of samples as Luminal-A-like (4.7% (9) distant events), 37% (119) as Luminal B-like (HER2 negative) (13.4% (16) distant events), 1.3% (4) as Triple negative (ductal) (25% (1) distant events), 0.6% (2) as “not defined according to St Gallen” (ESR1-/PGR+) (50% (1) distant events) and 0.6% (2) as Luminal B-like (HER2 positive) (no distant events).

When comparing Luminal A-like samples with the samples of the other subtypes in survival analysis, Luminal A-like samples had a significantly better distant disease free survival when assessing samples from patients with pN0 status (278) (p=0.0177, HR=0.344 (95% CI 0.137-0.866), pN1 status (0-3 affected nodes) (314) (p=0.0153, HR=0.374 (95% CI 0.163-0.855) as well as for all samples (p=0.0032, HR=0.319 (95% CI 0.143-0.711).

Conclusion:

Determination of HER2, ER, PR and Ki67 mRNA levels allows molecular subtyping according to the St Gallen surrogate subtype definition. Low risk of distant recurrence could be confirmed for the MammaTyper® Luminal A-like samples suggesting that for this patient group endocrine treatment alone may be sufficient. The high degree of standardization of mRNA measurement may drive the use of the Ki67/MKI67 biomarker in routine breast cancer pathology.

Citation Format: Laible M, Hartmann K, Gürtler C, Anzeneder T, Weber S, Keller T, Sahin U. Prediction of distant recurrence in low risk early breast cancer by RT-qPCR based subtyping using MammaTyper® [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-08-14.

[Pioneering surgical innovations in Germany : Part 1: generation of medical evidence]

BACKGROUND

In recent years research which conforms to evidence-based medicine (EBM) has been required even in surgery. Prospective, randomized studies are carried out in order to provide justification for the benefits of new procedures.

OBJECTIVE

The acquisition of special features in surgery with respect to the application of EBM.

MATERIAL AND METHODS

The investigation period selected was from1933 to 2013; therefore, all disciplines within the German Society of Surgery were questioned on the achievement of revolutionary innovations. The investigation was carried out utilizing personal interviews and a questionnaire. Only novel methods which were developed in Germany were considered. The survey was completed by carrying out research in database files.

RESULTS

During the past 80 years 15 pioneering innovations have been published in surgical research, although the prerequisites of EBM were only partly met. They appear to be based on the lowest level of evidence as these methods were mostly published as case reports or case series in journals with a low impact factor.

DISCUSSION

In general, innovative surgical procedures through top level research are still being published in the form of case reports or case series. This allows a rapid distribution of research results to the surgical community. Controlled studies still do not represent an alternative for the introduction of pioneering surgical innovations.

A Linear Programming Approach to Limited Angle 3D Reconstruction from DSA Projections

Objectives: We investigate the feasibility of binary-valued 3D tomographic reconstruction using only a small number of projections acquired over a limited range of angles.

Methods: Regularization of this strongly ill-posed problem is achieved by (i) confining the reconstruction to binary vessel/non-vessel decisions, and (ii) by minimizing a global functional involving a smoothness prior.

Results: Our approach successfully reconstructs volumetric vessel structures from three projections taken within 90°. The percentage of reconstructed voxels differing from ground truth is below 1%.

Conclusion: We demonstrate that for particular applications – like Digital Subtraction Angiography – 3D reconstructions are possible where conventional methods must fail, due to a severely limited imaging geometry. This could play an important role for dose reduction and 3D reconstruction using non-conventional technical setups.

Bonner Venenstudie der Deutschen Gesellschaft für Phlebologie

Ziel: Die Bonner Venenstudie zur Frage der Häufigkeit und Ausprägung von chronischen Venenkrankheiten in der städtischen und ländlichen deutschen Wohnbevölkerung im Alter von 18-79 Jahren fand zwischen dem 13. 11. 2000 und 15. 3. 2002 statt. Es nahmen insgesamt 3072 Probanden teil, die Response-Proportion lag insgesamt bei 59%. Ergebnisse: Eine Beinschwellung in der Anamnese trat bei jedem 6. Mann (16,2%) und bei nahezu jeder 2. Frau (42,1%) auf. Eine kurz zurückliegende ein- oder beidseitige Beinschwellung in den letzten vier Wochen gab jeder 6. Teilnehmer an. Dies entspricht 14,8% (7,9% der Männer, 20,2% der Frauen). Für Gefäßerkrankungen typische Beinbeschwerden innerhalb der letzten vier Wochen gab insgesamt jeder 2. der Probanden (56,4%) an. Bei der Beurteilung der klinischen Ausprägung gemäß der CEAP-Klassifikation fällt auf, dass lediglich 9,6% der Probanden keinerlei Venenveränderungen aufweisen. Bei 59% bestehen isoliert Teleangiektasien oder retikuläre Venen, bei 14,3% Krampfadern (C2) ohne weitere Zeichen einer chronischen venösen Insuffizienz. Auffällig ist, dass bei 13,4% ein prätibiales Ödem im Rahmen von Venenveränderungen zum Untersuchungszeitpunkt vorlag. Demgegenüber liegt die Zahl der fortgeschrittenen Zeichen der chronischen venösen Insuffizienz bei 3,3%. Die Häufigkeit des floriden oder abgeheilten Ulcus cruris lag bei 0,7%. Schlussfolgerungen: Jeder 6. Mann und jede 5. Frau hat somit chronische Veneninsuffizienz (C3–C6). Die Zahlen zeigen, dass Venenkrankheiten insgesamt nach wie vor eine hohe Prävalenz aufweisen, dass aber die schweren Ausprägungen der chronischen venösen Insuffizienz in den vergangenen 20 Jahren zurückgegangen sind.

Development of a high brightness ultrafast Transmission Electron Microscope based on a laser-driven cold field emission source

We report on the development of an ultrafast Transmission Electron Microscope based on a cold field emission source which can operate in either DC or ultrafast mode. Electron emission from a tungsten nanotip is triggered by femtosecond laser pulses which are tightly focused by optical components integrated inside a cold field emission source close to the cathode. The properties of the electron probe (brightness, angular current density, stability) are quantitatively determined. The measured brightness is the largest reported so far for UTEMs. Examples of imaging, diffraction and spectroscopy using ultrashort electron pulses are given. Finally, the potential of this instrument is illustrated by performing electron holography in the off-axis configuration using ultrashort electron pulses.

Patient-derived xenografts of gastrointestinal cancers are susceptible to rapid and delayed B-lymphoproliferation

Patient-derived cancer xenografts (PDX) are widely used to identify and evaluate novel therapeutic targets, and to test therapeutic approaches in preclinical mouse avatar trials. Despite their widespread use, potential caveats of PDX models remain considerably underappreciated. Here, we demonstrate that EBV-associated B-lymphoproliferations frequently develop following xenotransplantation of human colorectal and pancreatic carcinomas in highly immunodeficient NOD.Cg-Prkdc^scid Il2rg^tm1Wjl /SzJ (NSG) mice (18/47 and 4/37 mice, respectively), and in derived cell cultures in vitro. Strikingly, even PDX with carcinoma histology can host scarce EBV-infected B-lymphocytes that can fully overgrow carcinoma cells during serial passaging in vitro and in vivo. As serial xenografting is crucial to expand primary tumor tissue for biobanks and cohorts for preclinical mouse avatar trials, the emerging dominance of B-lymphoproliferations in serial PDX represents a serious confounding factor in these models. Consequently, repeated phenotypic assessments of serial PDX are mandatory at each expansion step to verify "bona fide" carcinoma xenografts.

Genetic subclone architecture of tumor clone-initiating cells in colorectal cancer

Combining high-coverage whole-genome sequencing with functional analyses, Giessler et al. demonstrate that tumor initiation and long-term tumor formation in human colorectal cancer are driven by multiple genomic subclones and that the functional heterogeneity of colorectal cancer tumor clone–initiating cells is not based on genomic architecture.

A hierarchically organized cell compartment drives colorectal cancer (CRC) progression. Genetic barcoding allows monitoring of the clonal output of tumorigenic cells without prospective isolation. In this study, we asked whether tumor clone-initiating cells (TcICs) were genetically heterogeneous and whether differences in self-renewal and activation reflected differential kinetics among individual subclones or functional hierarchies within subclones. Monitoring genomic subclone kinetics in three patient tumors and corresponding serial xenografts and spheroids by high-coverage whole-genome sequencing, clustering of genetic aberrations, subclone combinatorics, and mutational signature analysis revealed at least two to four genetic subclones per sample. Long-term growth in serial xenografts and spheroids was driven by multiple genomic subclones with profoundly differing growth dynamics and hence different quantitative contributions over time. Strikingly, genetic barcoding demonstrated stable functional heterogeneity of CRC TcICs during serial xenografting despite near-complete changes in genomic subclone contribution. This demonstrates that functional heterogeneity is, at least frequently, present within genomic subclones and independent of mutational subclone differences.

Correlation of endoscopic disease severity with pediatric ulcerative colitis activity index score in children and young adults with ulcerative colitis

AIM

To investigate of pediatric ulcerative colitis activity index (PUCAI) in ulcerative colitis correlate with mucosal inflammation and endoscopic assessment of disease activity (Mayo endoscopic score).

METHODS

We reviewed charts from ulcerative colitis patients who had undergone both colonoscopy over 3 years. Clinical assessment of disease severity within 35 d (either before or after) the colonoscopy were included. Patients were excluded if they had significant therapeutic interventions (such as the start of corticosteroids or immunosuppressive agents) between the colonoscopy and the clinical assessment. Mayo endoscopic score of the rectum and sigmoid were done by two gastroenterologists. Inter-observer variability in Mayo score was assessed.

RESULTS

We identified 99 patients (53% female, 74% pancolitis) that met inclusion criteria. The indications for colonoscopy included ongoing disease activity (62%), consideration of medication change (10%), assessment of medication efficacy (14%), and cancer screening (14%). Based on PUCAI scores, 33% of patients were in remission, 39% had mild disease, 23% had moderate disease, and 4% had severe disease. There was “moderate-substantial” agreement between the two reviewers in assessing rectal Mayo scores (kappa = 0.54, 95%CI: 0.41-0.68).

CONCLUSION

Endoscopic disease severity (Mayo score) assessed by reviewing photographs of pediatric colonoscopy has moderate inter-rater reliability, and agreement was less robust in assessing patients with mild disease activity. Endoscopic disease severity generally correlates with clinical disease severity as measured by PUCAI score. However, children with inflamed colons can have significant variation in their reported clinical symptoms. Thus, assessment of both clinical symptoms and endoscopic disease severity may be required in future clinical studies.

Transition from Collisional to Collisionless Regimes in Interpenetrating Plasma Flows on the National Ignition Facility

A study of the transition from collisional to collisionless plasma flows has been carried out at the National Ignition Facility using high Mach number (M>4) counterstreaming plasmas. In these experiments, CD-CD and CD-CH planar foils separated by 6-10 mm are irradiated with laser energies of 250 kJ per foil, generating ∼1000  km/s plasma flows. Varying the foil separation distance scales the ion density and average bulk velocity and, therefore, the ion-ion Coulomb mean free path, at the interaction region at the midplane. The characteristics of the flow interaction have been inferred from the neutrons and protons generated by deuteron-deuteron interactions and by x-ray emission from the hot, interpenetrating, and interacting plasmas. A localized burst of neutrons and bright x-ray emission near the midpoint of the counterstreaming flows was observed, suggesting strong heating and the initial stages of shock formation. As the separation of the CD-CH foils increases we observe enhanced neutron production compared to particle-in-cell simulations that include Coulomb collisions, but do not include collective collisionless plasma instabilities. The observed plasma heating and enhanced neutron production is consistent with the initial stages of collisionless shock formation, mediated by the Weibel filamentation instability.

The molluscum contagiosum virus death effector domain containing protein MC160 RxDL motifs are not required for its known viral immune evasion functions

The molluscum contagiosum virus (MCV) uses a variety of immune evasion strategies to antagonize host immune responses. Two MCV proteins, MC159 and MC160, contain tandem death effector domains (DEDs). They are reported to inhibit innate immune signaling events such as NF-κB and IRF3 activation, and apoptosis. The RxDL motif of MC159 is required for inhibition of both apoptosis and NF-κB activation. However, the role of the conserved RxDL motif in the MC160 DEDs remained unknown. To answer this question, we performed alanine mutations to neutralize the arginine and aspartate residues present in the MC160 RxDL in both DED1 and DED2. These mutations were further modeled against the structure of the MC159 protein. Surprisingly, the RxDL motif was not required for MC160's ability to inhibit MAVS-induced IFNβ activation. Further, unlike previous results with the MC159 protein, mutations within the RxDL motif of MC160 had no effect on the ability of MC160 to dampen TNF-α-induced NF-κB activation. Molecular modeling predictions revealed no overall changes to the structure in the MC160 protein when the amino acids of both RxDL motifs were mutated to alanine (DED1 = R67A D69A; DED2 = R160A D162A). Taken together, our results demonstrate that the RxDL motifs present in the MC160 DEDs are not required for known functions of the viral protein.

Measurement system for temperature dependent noise characterization of magnetoresistive sensors

Magnetoresistive (MR) sensors and sensor systems are used in a large variety of applications in the field of industrial automation, automotive business, aeronautic industries, and instrumentation. Different MR sensor technologies like anisotropic magnetoresistive, giant magnetoresistive, and tunnel magnetoresistive sensors show strongly varying properties in terms of magnetoresistive effect, response to magnetic fields, achievable element miniaturization, manufacturing effort, and signal-to-noise ratio. Very few data have been reported so far on the comparison of noise performance for different sensor models and technologies, especially including the temperature dependence of their characteristics. In this paper, a stand-alone measurement setup is presented that allows a comprehensive characterization of MR sensors including sensitivity and noise over a wide range of temperatures.

Role of Frequency Chirp and Energy Flow Directionality in the Strong Coupling Regime of Brillouin-Based Plasma Amplification

A detailed analysis is presented of the various stages of strong coupling Brillouin plasma amplification, emphasizing the importance of the chirp which can be of threefold origin: the intrinsic one driven by the amplification process, the one originating from the chirped-pulse-generated laser pulses, and the one associated with the plasma profile. Control of the overall chirp can optimize or quench the energy transfer. The time-dependent phase relation explains the energy flow direction during amplification and is characteristic for this strong coupling process. The study is also of potential importance to understand and maybe control cross-beam-energy transfer in inertial confinement fusion.

A microwave resonator integrated on a polymer microfluidic chip

We describe a novel stacked split-ring type microwave (MW) resonator that is integrated into a 10mm by 10mm sized microfluidic chip. A straightforward and scalable batch fabrication process renders the chip suitable for single-use applications. The resonator volume can be conveniently loaded with liquid sample via microfluidic channels patterned into the mid layer of the chip. The proposed MW resonator offers an alternative solution for compact in-field measurements, such as low-field magnetic resonance (MR) experiments requiring convenient sample exchange. A microstrip line was used to inductively couple MWs into the resonator. We characterised the proposed resonator topology by electromagnetic (EM) field simulations, a field perturbation method, as well as by return loss measurements. Electron paramagnetic resonance (EPR) spectra at X-band frequencies were recorded, revealing an electron-spin sensitivity of 3.7·10(11)spins·Hz(-1/2)G(-1) for a single EPR transition. Preliminary time-resolved EPR experiments on light-induced triplet states in pentacene were performed to estimate the MW conversion efficiency of the resonator.

Vascularization of malignant and benign skin tumours measured by d-galactose-based signal-enhanced colour doppler sonography

Purpose: Evaluation of colour Doppler criteria to differentiate between malignant and benign skin tumours on the basis of the degree of vascularization.

Material and Methods: The B-mode sonomorphology and the degree of vascularization in colour Doppler of 81 clinically potentially malignant tumours of cutaneous and subcutaneous structures were analyzed and quantified by number of intratumoral vessels per sonographic slice and percentage vessel area.

Results: Of all criteria employed, counting the intratumoral vessels visible on one ultrasound slice after application of a signal-enhancing agent led to highest sensitivity (94%) of all used criteria but the specificity was poor (64%). The highest specificity (88%) and greatest diagnostic accuracy (86%) discriminating benign and malignant lesions were found using the criterion "percentage vessel area &gt;5.0%" after all inflamed lesions had been excluded on the basis of clinical criteria. Plain colour Doppler increased the specificity up to 97%, although the sensitivity decreased simultaneously to max. 75%. Analysis of the B-mode morphology and spectral Doppler parameter of intratumoral vessels did not contribute to the differential diagnosis.

Conclusion: Signal-enhanced colour Doppler sonography is a valuable tool in the pretherapeutic assessment of cutaneous lesions. This method may be relevant for therapy and prognosis.

Abstract 910: Genetic subclone heterogeneity of the human colon cancer initiating cell compartment

A subpopulation of tumor-initiating cells (TIC) drives colorectal cancer (CRC) progression in serial xenotransplantation. Strikingly, the CRC TIC compartment itself is heterogeneous and comprised of a hierarchy of long-term (LT-) TIC, tumor transient amplifying cells (T-TAC) and delayed contributing (DC-) TIC. Whether this functionally heterogeneous TIC compartment is genetically homogenous or whether distinct genetic subclones drive the functional heterogeneity of the TIC compartment is yet unknown. To address this question, we performed high coverage (91-126 fold) whole genome sequencing on primary CRC patient tumors (n = 3), corresponding serially passaged TIC enriched spheroids as well as spheroid derived serial xenografts. Sequenced samples harbored between 22.800 and 232.000 synonymous or non-synonymous single nucleotide variants (SNVs). In addition, all samples contained multiple focal or large-scale somatic copy number alterations (CNAs). Clustering of SNVs as well as subclonal copy numbers from serial xenografts and spheroids were used to define SNV- and CNA-based subpopulations. Next, cellular fractions of identified subpopulations were determined and combined applying maximal parsimony to create models of the minimal number of subclones present in each sample. Using this strategy, we found that multiple subclones were present in each sample analyzed. Subclone heterogeneity was maintained during serial in vitro passaging and serial xenografting. Importantly, tumor initiation in xenografts was driven by at least 3 distinct genetic subclones whose relative contribution dynamically changed over time. Strikingly, in serial samples from the same patients, different genetic subclones grew out in vivo and in vitro.

To test whether functional heterogeneity of the TIC compartment is related to the presence of genetic subclones, we assessed the contribution of different TIC subtypes - LT-TIC, T-TAC and DC-TIC - at early and late time points of xenografting using secondary genetic marking. Therefore, 1×10⁁5 cells derived from early and late generation xenografts were transduced with an integrating lentiviral vector, thereby generating a stable barcode-like genetic mark which differs in each transduced cell. Following serial transplantation of transduced cells for 3 mouse generations, tumors were harvested and lentiviral integration sites were determined using highly sensitive LAM-PCR and high-throughput sequencing. Assessing the relative contribution of LT-TIC, T-TAC and DC-TIC revealed that the functional heterogeneity of the TIC compartment was preserved despite profound genetic subclone dynamics in serial xenotransplantation. These results strongly indicate that multiple genetic subclones drive long-term tumor formation and that functional heterogeneity of the CRC TIC compartment is not based on specific genetic subclones.

Citation Format: Klara M. Giessler, Kortine Kleinheinz, Gnana Prakash Balasubramanian, Daniel Hübschmann, Taronish D. Dubash Rai, Sebastian D. Dieter, Christine Siegl, Christopher M. Hoffmann, Sarah Weber, Raffaele Fronza, Saira Afzal, Manfred Schmidt, Martin Schneider, Alexis Ulrich, Juergen Weitz, Wilko Weichert, Matthias Schlesner, Benedikt Brors, Claudia R. Ball, Hanno Glimm. Genetic subclone heterogeneity of the human colon cancer initiating cell compartment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 910.

Postoperative Color Flow Duplex Scanning in Aortic Endografting

Purpose:

To report the feasibility and sensitivity of duplex sonography compared to computed tomography (CT) for aortic endograft follow-up surveillance.

Methods:

In a 26-month period, 113 aortic aneurysm patients received 79 tube and 34 bifurcated stent-grafts. Follow-up used contrast-enhanced CT scanning and duplex sonography with an intravenous ultrasound contrast agent (Levovist).

Results:

Eleven patients (9.7%) were converted to open repair; 1 died from hemorrhagic shock secondary to retroperitoneal hematoma. The mean follow-up time was 7.2 months (range 1 to 24), during which 5 patients died of unrelated causes. Sixteen primary (within 30 days) and 5 secondary endoleaks were detected by duplex after tube graft implantation. Among 5 endoleaks due to retrograde side-branch perfusion, 3 were detected only with contrast-enhanced duplex scanning. Iliac artery occlusion was also documented using duplex; however, 2 stent fractures could not be seen with ultrasound. Ten primary endoleaks were detected in bifurcated stent-graft patients. One endoleak originating from the distal iliac limb anchoring site was missed by duplex owing to bowel gas. Graft limb thrombosis was clearly identified by lack of a flow signal on duplex.

Conclusions:

Duplex sonography could be a valuable, reliable, and economical surveillance tool for endovascular aortic reconstructions. The adjunctive use of an intravenous ultrasound contrast agent increased the sensitivity for detecting endoleak to a level comparable to contrast-enhanced CT scanning. However, stent fractures may not be seen on ultrasound, and bowel gas can interfere with obtaining an adequate image.

[Pioneering surgical innovations in Germany : Part 2: public funding and origins of surgical innovations]

BACKGROUND

In recent years research that conforms with evidence-based medicine (EBM) has been demanded even in surgery. Uniform studies were carried out to prove the benefits of new procedures; however, compared to other research sectors, public third party funding for surgical research was significantly cut back.

OBJECTIVE

Collation of special features in surgery with respect to external funding of surgical top level research. Examination of the benefits of a continuous promotion and of organizations involved in research.

MATERIAL AND METHODS

Part one of this investigation presented the methods used to identify and analyze pioneering research in surgery.

RESULTS

Out of a total of 15 revolutionary innovations only 3 projects were financed by external funding and 2 projects received indirect financial support as a result of a cooperation with the medical industry. This demonstrates that the majority of projects were neither directly nor indirectly subsidized. Apart from one instance the majority of innovations were generated by university hospitals highly active in research.

DISCUSSION

In effect, the non-existing external funding for outstanding surgical innovations and hospitals suggests that a reformation of surgical research is required. To strengthen the quality of innovations in surgery a concentration of funding to institutions that are highly active in research makes sense. Institutional funding directly linked to a project should form a key component of support particularly in the early stages of development.

Signatures of the Self-Similar Regime of Strongly Coupled Stimulated Brillouin Scattering for Efficient Short Laser Pulse Amplification

Plasma-based laser amplification is considered as a possible way to overcome the technological limits of present day laser systems and achieve exawatt laser pulses. Efficient amplification of a picosecond laser pulse by stimulated Brillouin scattering (SBS) of a pump pulse in a plasma requires to reach the self-similar regime of the strongly coupled (SC) SBS. In this Letter, we report on the first observation of the signatures of the transition from linear to self-similar regimes of SC-SBS, so far only predicted by theory and simulations. With a new fully head-on collision geometry, subpicosecond pulses are amplified by a factor of 5 with energy transfers of few tens of mJ. We observe pulse shortening, frequency spectrum broadening, and down-shifting for increasing gain, signatures of SC-SBS amplification entering the self-similar regime. This is also confirmed by the power law dependence of the gain on the amplification length: doubling the interaction length increases the gain by a factor 1.4. Pump backward Raman scattering (BRS) on SC-SBS amplification has been measured for the first time, showing a strong decrease of the BRS amplitude and frequency bandwidth when SBS seed amplification occurs.