9 research outputs found

    The impact of selected planned motorways and expressways on the potential accessibility of the Polish-Slovak borderland with respect to tourism development

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    Further tourism development in the Polish-Slovak borderland, as well as its overall economic development, depends on the construction of a motorway and expressway network. This paper analyses the impact of selected planned motorways and expressways (D1, A4, D3/S69, R1/R3/S7, and R4/S19) on the potential accessibility of the Polish-Slovak borderland with respect to the development of tourism. The most important investment project in Slovakia is the completion of the (started) D1 motorway. The R4/S19 and the R1/R3/S7 expressways and the D3 motorway/S69 expressway are expected to contribute to improved cross-border connections

    Influence of Nuclides and Chelators on Imaging Using Affibody Molecules : Comparative Evaluation of Recombinant Affibody Molecules Site-Specifically Labeled with 68Ga and 111In via Maleimido Derivatives of DOTA and NODAGA

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    Accurate detection of cancer-associated molecular abnormalities in tumors could make cancer treatment more personalized. Affibody molecules enable high contrast imaging of tumor-associated protein expression shortly after injection. The use of the generator-produced positron-emitting radionuclide 68Ga should increase sensitivity of HER2 imaging. The chemical nature of radionuclides and chelators influences the biodistribution of Affibody molecules, providing an opportunity to further increase the imaging contrast. The aim of the study was to compare maleimido derivatives of DOTA and NODAGA for site-specific labeling of a recombinant ZHER2:2395 HER2-binding Affibody molecule with 68Ga. DOTA and NODAGA were site-specifically conjugated to the ZHER2:2395 Affibody molecule having a C-terminal cysteine and labeled with 68Ga and 111In. All labeled conjugates retained specificity to HER2 in vitro. Most of the cell-associated activity was membrane-bound with a minor difference in internalization rate. All variants demonstrated specific targeting of xenografts and a high tumor uptake. The xenografts were clearly visualized using all conjugates. The influence of chelator on the biodistribution and targeting properties was much less pronounced for 68Ga than for 111In. The tumor uptake of 68Ga-NODAGA-ZHER2:2395 and 68Ga-DOTA-ZHER2:2395 and tumor-to-blood ratios at 2 h p.i. did not differ significantly. However, the tumor-to-liver ratio was significantly higher for 68Ga-NODAGA- ZHER2:2395 (8 ± 2 vs 5.0 ± 0.3) offering the advantage of better liver metastases visualization. In conclusion, influence of chelators on biodistribution of Affibody molecules depends on the radionuclides and reoptimization of labeling chemistry is required when a radionuclide label is changed.De två (2) första författarna delar förstaförfattarskapet.</p

    Nuclear expression of Ku70/80 is associated with CHEK2 germline mutations in breast cancer

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    Ku70/80 protein inhibitors reduce the repair of DNA double-strand breaks via the Ku70/80 pathway, so they can be used to treat cancers with Ku70/80 overexpression. Since the association of Ku70/80 with germline CHEK2 mutations in breast cancer is unknown, in this study we evaluated the expression of Ku70/80 in breast cancers with germline CHEK2 mutations. Immunohistochemistry with a Ku70/80 antibody on tissue microarrays from 225 CHEK2-associated breast cancers was used and automatically assessed with computerized image analysis. We report that the vast majority of breast cancers expressed high level of nuclear Ku70/80 and a small percentage of tumors (3.5%) were negative for Ku70/80 expression. There was a significant difference between the nuclear Ku70/80 expression in CHEK2-associated vs. CHEK2-non-associated breast cancers in all tumors (p = 0.009), and in the estrogen receptor (ER) positive subgroup of breast cancers (p = 0.03). This study is the first reporting an association of Ku70/80 expression with CHEK2 germline mutations in breast cancer. The results suggest that evaluation of Ku70/80 expression in breast cancer may improve the selection of breast cancer patients for Ku70/80 inhibitor therapy, and point to CHEK2-associated breast cancer and a subset of ER-positive breast cancer as potential suitable targets for such therapy

    Incorporation of a Triglutamyl Spacer Improves the Biodistribution of Synthetic Affibody Molecules Radiofluorinated at the N-Terminus via Oxime Formation with (18)F-4-Fluorobenzaldehyde

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    Affibody molecules are a class of affinity agents for molecular imaging based on a non-immunoglobulin protein scaffold. Previous studies have demonstrated high contrast for in vivo imaging of cancer-associated molecular abnormalities using Affibody molecules. Using the radionuclide (18)F for labeling and PET as the imaging modality, the sensitivity of molecular imaging using Affibody molecules can be further increased. The use of oxime formation between an aminooxy-functionalized peptide and (18)F-fluorobenzaldehyde ((18)F-FBA) is a promising way of radiolabeling of targeting peptides. However, previous studies demonstrated that application of this method to Affibody molecules is associated with high liver uptake. We hypothesized that incorporation of a triglutamyl spacer between the aminooxy moiety and the N-terminus of a synthetic Affibody molecule would decrease the hepatic uptake of the (18)F-N-(4-fluorobenzylidine)oxime) ((18)F-FBO)-labeled tracer. To verify this, we have produced two variants of the HER2-targeting ZHER2:342 Affibody molecule by peptide synthesis: OA-PEP4313, where aminooxyacetic acid was conjugated directly to the N-terminal alanine, and OA-E3-PEP4313, where a triglutamyl spacer was introduced between the aminooxy moiety and the N-terminus. We have found that the use of the spacer is associated with a minor decrease of affinity, from KD = 49 pM to KD = 180 pM. Radiolabeled (18)F-FBO-E3-PEP4313 demonstrated specific binding to HER2-expressing ovarian carcinoma SKOV-3 cells and slow internalization. Biodistribution studies in mice demonstrated that the use of a triglutamyl linker decreased uptake of radioactivity in liver 2.7-fold at 2 h after injection. Interestingly, radioactivity uptake in kidneys was also reduced (2.4-fold). Experiments in BALB/C nu/nu mice bearing SKOV-3 xenografts demonstrated HER2-specific uptake of (18)F-FBO-E3-PEP4313 in tumors. At 2 h pi, the tumor uptake (20 ± 2% ID/g) exceeded uptake in liver 5-fold and uptake in kidneys 3.6-fold. The tumor-to-blood ratio was 21 ± 3. The microPET/CT imaging experiment confirmed the biodistribution data. In conclusion, the use of a triglutamyl spacer is a convenient way to improve the biodistribution profile of Affibody molecules labeled at the N-terminus using (18)F-FBA. It provides a tracer capable of producing high-contrast images of HER2-expressing tumors
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