Inverse electron demand Diels-Alder click chemistry for pretargeted PET imaging and radioimmunotherapy

This approach leverages the rapid, bio-orthogonal inverse electron demand Diels-Alder reaction between a radiolabeled tetrazine and a trans-cyclooctene-bearing antibody to enable pretargeted positron emission tomography imaging and endoradiotherapy in a murine model of cancer. Radiolabeled antibodies have shown promise as tools for both the nuclear imaging and endoradiotherapy of cancer, but the protracted circulation time of radioimmunoconjugates can lead to high radiation doses to healthy tissues. To circumvent this issue, we have developed an approach to positron emission tomography (PET) imaging and radioimmunotherapy (RIT) predicated on radiolabeling the antibody after it has reached its target within the body. This in vivo pretargeting strategy is based on the rapid and bio-orthogonal inverse electron demand Diels-Alder reaction between tetrazine (Tz) and trans-cyclooctene (TCO). Pretargeted PET imaging and RIT using TCO-modified antibodies in conjunction with Tz-bearing radioligands produce high activity concentrations in target tissues as well as reduced radiation doses to healthy organs compared to directly labeled radioimmunoconjugates. Herein, we describe how to prepare a TCO-modified antibody (humanized A33-TCO) as well as how to synthesize two Tz-bearing radioligands: one labeled with the positron-emitting radiometal copper-64 ([Cu-64]Cu-SarAr-Tz) and one labeled with the beta-emitting radiolanthanide lutetium-177 ([Lu-177]Lu-DOTA-PEG(7)-Tz). We also provide a detailed description of pretargeted PET and pretargeted RIT experiments in a murine model of human colorectal carcinoma. Proper training in both radiation safety and the handling of laboratory mice is required for the successful execution of this protocol.Peer reviewe

A Pretargeted Approach for the Multimodal PET/NIRF Imaging of Colorectal Cancer

The complementary nature of positron emission tomography (PET) and near-infrared fluorescence (NIRF) imaging makes the development of strategies for the multimodal PET/NIRF imaging of cancer a very enticing prospect. Indeed, in the context of colorectal cancer, a single multimodal PET/NIRF imaging agent could be used to stage the disease, identify candidates for surgical intervention, and facilitate the image-guided resection of the disease. While antibodies have proven to be highly effective vectors for the delivery of radioisotopes and fluorophores to malignant tissues, the use of radioimmunoconjugates labeled with long-lived nuclides such as 89Zr poses two important clinical complications: high radiation doses to the patient and the need for significant lag time between imaging and surgery. In vivo pretargeting strategies that decouple the targeting vector from the radioactivity at the time of injection have the potential to circumvent these issues by facilitating the use of positron-emitting radioisotopes with far shorter half-lives. Here, we report the synthesis, characterization, and in vivo validation of a pretargeted strategy for the multimodal PET and NIRF imaging of colorectal carcinoma. This approach is based on the rapid and bioorthogonal ligation between a trans-cyclooctene- and fluorophore-bearing immunoconjugate of the huA33 antibody (huA33-Dye800-TCO) and a 64Cu-labeled tetrazine radioligand (64Cu-Tz-SarAr). In vivo imaging experiments in mice bearing A33 antigen-expressing SW1222 colorectal cancer xenografts clearly demonstrate that this approach enables the non-invasive visualization of tumors and the image-guided resection of malignant tissue, all at only a fraction of the radiation dose created by a directly labeled radioimmunoconjugate. Additional in vivo experiments in peritoneal and patient-derived xenograft models of colorectal carcinoma reinforce the efficacy of this methodology and underscore its potential as an innovative and useful clinical tool

Submicrometer Pattern Fabrication by Intensification of Instability in Ultrathin Polymer Films under a Water-Solvent Mix

Dewetting of ultrathin (< 100 nm) polymer films, by heating above the glass transition, produces droplets of sizes of the order of microns and mean separations between droplets of the order of tens of microns. These relatively large length scales are because of the weak destabilizing van der Waals forces and the high surface energy penalty required for deformations on small scales. We show a simple, one-step versatile method to fabricate sub-micron (>~100 nm) droplets and their ordered arrays by room temperature dewetting of ultrathin polystyrene (PS) films by minimizing these limitations. This is achieved by controlled room temperature dewetting under an optimal mixture of water, acetone and methyl-ethyl ketone (MEK). Diffusion of organic solvents in the film greatly reduces its glass transition temperature and the interfacial tension, but enhances the destabilizing field by introduction of electrostatic force. The latter is reflected in a change in the exponent, n of the instability length scale, {\lambda} ~h^n, where h is the film thickness and n = 1.51 \pm 0.06 in the case of water-solvent mix, as opposed to its value of 2.19 \pm 0.07 for dewetting in air. The net outcome is more than one order of magnitude reduction in the droplet size as well as their mean separation and also a much faster dynamics of dewetting. We also demonstrate the use of this technique for controlled dewetting on topographically patterned substrates with submicrometer features where dewetting in air is either arrested, incomplete or unable to produce ordered patterns

MARINE CORPS ACQUISITION OPTIMIZATION

MBA Professional ProjectThe purpose of this report is to provide a comprehensive analysis on how the United States Marine Corps conducts contracting and acquisition activities. This report further evaluates how those activities, when optimized, can enable the Marine Corps to be ready to fight and win within current and future operating environments. This report begins by dissecting the status quo through the three pillars of acquisitions and contracting. The three pillars are: people, or talent management; processes, the mindset with which acquisition decisions are made; and platforms, the vehicles used in that acquisition. Through these three pillars, this report examines the status quo and identifies its strengths, weaknesses, opportunities, and threats. This study then explores multiple optimization alternatives to the status quo, for each of the three pillars, and discusses their respective merits and deficiencies. Finally, based on the results of the analysis, this report provides comprehensive recommendations that have the potential of optimizing operational contracting support and the capabilities the Marine Corps contingency contracting force can provide commanders at every level.http://archive.org/details/marinecorpsacqui1094561305Captain, United States Marine CorpsCaptain, United States Marine CorpsCaptain, United States Marine Corp

Usefullness of the ultrasonically activated scalpel in laparoscopic cholecystectomy: our experience and review of literature

Laparoscopic cholecystectomy (LC) actually represents the most used and proper treatment for gallbladder lithiasis, because its many and known advantages in comparison with ‘open’ abdominal surgery. But there are some problems during and after LC due to the use of the electric scalpel and these have brought to the search of an alternative system of dissection and coagulation. The ultrasonically activated scalpel (Harmonic Scalpel, HS) allows to perform dissection and coagulation with a minimal thermal side effect for surrounding tissues, unlike the electrocoagulation. Furthermore, the use of the HS brings a series of advantages in comparison to the other electromagnetic forms of energy (electroscalpel, laser). HS cuts and coagulates with the same effectiveness of the electroscalpel but, unlike this, it doesn't introduce risks of wandering currents. Moreover, HS contributes to have a more clean and clear (smokes-free) field of operation and it reduces the operative time, the bleeding and the costs of the operation without an increase of the complications and of the percentages of ‘open’ conversion, and perhaps leads to a less negative influence on the postoperative systemic immune response. The Authors report their experience that confirm these observations, according also with results reported in a brief review of the recent scientific literature, and support wider diffusion and technical development of this ultrasonically-operating surgical team

Investment and Demand Uncertainty: An Investigation with a Panel of Italian Firms

In the last fifteen years the debate about the investment-uncertainty relationship has flourished. From a theoretical point of view, uncertainty over the demand for a firm’s product may have unclear effects on investments, as it depends on a number of factors (such as the production technology and the degree of competition in the product market). Even assuming risk neutrality, the sign and the intensity of the investment-uncertainty relationship cannot be settled on purely theoretical grounds but need an empirical investigation. The aim of this paper is to extend the findings of the empirical literature by using a panel of Italian firms over a fairly long period of time (1996-2004), covering a complete business cycle. The availability of a panel of survey data about companies’ investment plans, expected future sales and demand uncertainty allows us to account for unobservable individual firm differences and for macroeconomic shocks, and to avoid the use of proxies based on assumptions at least quite restrictive. A key finding from our analysis is the increasing weakness over time of the link between investment plans and uncertainty. In explaining this fact, the results of the paper emphasise the influence on the investment-uncertainty relationship of the increase in the competition faced by Italian firms in the period under scrutiny. If our empirical analyses had been conducted with realised, instead of planned, data about the variables of interest, previous findings at best would have weaken, making evident that data of survey’s questionnaires are a key ingredient for appropriately modelling companies’ behaviour