Особенности акушерско-гинекологического консультирования беременных, страдающих эпилепсией

БЕРЕМЕННОСТИ ОСЛОЖНЕНИЯЭПИЛЕПСИ

Возникновение первых аптек в восточной части территории Республики Беларусь в дореволюционный период (12-19 вв.)

АПТЕКИИСТОРИЯ МЕДИЦИН

Использование РДФ-топлива в качестве энергетического ресурса (опыт Европейского союза)

Материалы XI Междунар. науч. конф. студентов, аспирантов и молодых ученых, Гомель, 17-18 мая 2018 г

Антигипертензивные средства могут снизить риск развития деменции

ДЕМЕНЦИЯАНТИГИПЕРТЕНЗИВНЫЕ СРЕДСТВАФАКТОРЫ РИСК

Development of Affibody molecules for radionuclide molecular imaging and therapy of cancer

Affibody molecules are a promising class of scaffold-based targeting proteins for radionuclide-based imaging and therapy of cancer. This thesis work is based on 5 original research articles (papers I-V), which focus on optimization of molecular design of HER2-binding Affibody variants for high contrast imaging of this predictive biomarker as well as development of Affibody molecules suitable for radionuclide-based targeted therapies.  Papers I and II were dedicated to evaluation of the influence of the macrocyclic chelator DOTA positioning at N-terminus, in the middle of helix-3 and at C terminus of a synthetic Affibody molecule, ZHER2:S1. These synthetic variants were labelled with different radionuclides i.e. 111In and 68Ga to study also the effect of different labels on their biodistribution properties. In paper III a 2-helix variant, Z342min, was developed using native ligation cyclization to cross-link helices one and two resulting in a stable 2-helix scaffold and characterized in vivo. This study was performed with the aim to obtain structure-properties relationship for development of smaller Affibody molecules.   Papers IV and V were devoted to development of therapeutic strategies. In paper IV, a series of peptide based chelators was investigated for labelling of Affibody molecules with 188Re to provide low renal retention. In paper V, a pretargeting approach using peptide nucleic acid was investigated. These studies were performed with the aim to overcome the high renal retention of Affibody molecules when labelled with residualizing therapeutic radionuclides. Otherwise, the particle emitting radiometals could damage the kidneys more than the tumours. The results obtained for anti-HER2 Affibody molecules summarized in this thesis might be of importance for the development of other scaffold protein based targeting agents.

Экономика: Интегрированный модуль

Affibody molecules are small scaffold-based affinity proteins with promising properties as probes for radionuclide-based molecular imaging. However, a high reabsorption of radiolabeled Affibody molecules in kidneys is an issue. We have shown that the use of I-125-3-iodo-((4-hydroxyphenyl)ethyl)maleimide (IHPEM) for site-specific labeling of cysteine-containing Affibody molecules provides high tumor uptake but low radioactivity retention in kidneys. We hypothesized that the use of 4-iodophenethylmaleimide (IPEM) would further reduce renal retention of radioactivity because of higher lipophilicity of radiometabolites. An anti-human epidermal growth factor receptor type2 (HER2) Affibody molecule (Z(HER2:2395)) was labeled using I-125-IPEM with an overall yield of 45 +/- 3%. I-125-IPEM-Z(HER2:2395) bound specifically to HER2-expressing human ovarian carcinoma cells (SKOV-3 cell line). In NMRI mice, the renal uptake of I-125-IPEM-Z(HER2:2395) (24 +/- 2 and 5.7 +/- 0.3%IAg(-1)at 1 and 4 h after injection, respectively) was significantly lower than uptake of I-125-IHPEM-Z(HER2:2395) (50 +/- 8 and 12 +/- 2%IAg(-1)at 1 and 4 h after injection, respectively). In conclusion, the use of a more lipophilic linker for the radioiodination of Affibody molecules reduces renal radioactivity

Feasibility of Affibody Molecule-Based PNA-Mediated Radionuclide Pretargeting of Malignant Tumors

Affibody molecules are small (7 kDa), non-immunoglobulin scaffold proteins with a potential as targeting agents for radionuclide imaging of cancer. However, high renal re-absorption of Affibody molecules prevents their use for radionuclide therapy with residualizing radiometals. We hypothesized that the use of Affibody-based peptide nucleic acid (PNA)-mediated pretargeting would enable higher accumulation of radiometals in tumors than in kidneys. To test this hypothesis, we designed an Affibody-PNA chimera ZHER2:342-SR-HP1 containing a 15-mer HP1 PNA recognition tag and a complementary HP2 hybridization probe permitting labeling with both (125)I and (111)In. (111)In-ZHER2:342-SR-HP1 bound specifically to HER2-expressing BT474 and SKOV-3 cancer cells in vitro, with a KD of 6±2 pM for binding to SKOV-3 cells. Specific high affinity binding of the radiolabeled complementary PNA probe (111)In-/(125)I-HP2 to ZHER2:342-SR-HP1 pre-treated cells was demonstrated. (111)In-ZHER2:342-SR-HP1 demonstrated specific accumulation in SKOV-3 xenografts in BALB/C nu/nu mice and rapid clearance from blood. Pre-saturation of SKOV-3 with non-labeled anti-HER2 Affibody or the use of HER2-negative Ramos xenografts resulted in significantly lower tumor uptake of (111)In-ZHER2:342-SR-HP1. The complementary PNA probe (111)In/(125)I-HP2 accumulated in SKOV-3 xenografts when ZHER2:342-SR-HP1 was injected 4 h earlier. The tumor accumulation of (111)In/(125)I-HP2 was negligible without ZHER2:342-SR-HP1 pre-injection. The uptake of (111)In-HP2 in SKOV-3 xenografts was 19±2 %ID/g at 1 h after injection. The uptake in blood and kidneys was approximately 50- and 2-fold lower, respectively. In conclusion, we have shown that the use of Affibody-based PNA-mediated pretargeting enables specific delivery of radiometals to tumors and provides higher radiometal concentration in tumors than in kidneys.De två första författarna delar förstaförfattarskapet och de två sista författarna delar sistaförfattarskapet.</p

Evaluation of (99m)Tc-Z IGF1R:4551-GGGC affibody molecule, a new probe for imaging of insulin-like growth factor type 1 receptor expression

Overexpression of insulin-like growth factor-1 receptor (IGF-1R) in several cancers is associated with resistance to therapy. Radionuclide molecular imaging of IGF-1R expression in tumors may help in selecting the patients that will potentially respond to IGF-1R-targeted therapy. Affibody molecules are small (7 kDa) non-immunoglobulin-based scaffold proteins that are well-suited probes for radionuclide imaging. The aim of this study was the evaluation of an anti-IGF-1R affibody molecule labeled with technetium-99m using cysteine-containing peptide-based chelator GGGC at C-terminus. ZIGF1R:4551-GGGC was efficiently and stably labeled with technetium-99m (radiochemical yield 97 ± 3 %). (99m)Tc-ZIGF1R:4551-GGGC demonstrated specific binding to IGF-1R-expressing DU-145 (prostate cancer) and MCF-7 (breast cancer) cell lines and slow internalization in vitro. The tumor-targeting properties were studied in BALB/c nu/nu mice bearing DU-145 and MCF-7 xenografts. [(99m)Tc(CO)3](+)-(HE)3-ZIGF1R:4551 was used for comparison. The biodistribution study demonstrated high tumor-to-blood ratios (6.2 ± 0.9 and 6.9 ± 1.0, for DU-145 and MCF-7, respectively, at 4 h after injection). Renal radioactivity concentration was 16-fold lower for (99m)Tc-ZIGF1R:4551-GGGC than for [(99m)Tc(CO)3](+)-(HE)3-ZIGF1R:4551 at 4 h after injection. However, the liver uptake of (99m)Tc-ZIGF1R:4551-GGGC was 1.2- to 2-fold higher in comparison with [(99m)Tc(CO)3](+)-(HE)3-ZIGF1R:4551. A possible reason for the elevated hepatic uptake of (99m)Tc-ZIGF1R:4551-GGGC is a high lipophilicity of amino acids in the binding site of ZIGF1R:4551, which is not compensated in (99m)Tc-ZIGF1R:4551-GGGC. In conclusion, (99m)Tc-ZIGF1R:4551-GGGC can visualize the IGF-1R expression in human tumor xenografts and provides low retention of radioactivity in kidneys. Further development of this imaging agent should include molecular design aimed at reducing the hepatic uptake

Position for Site-Specific Attachment of a DOTA Chelator to Synthetic Affibody Molecules Has a Different Influence on the Targeting Properties of Ga-Compared to In-Labeled Conjugates

Affibody molecules, small (7 kDa) scaffold proteins, are a promising class of probes for radionuclide molecular imaging. Radiolabeling of Affibody molecules with the positron-emitting nuclide 68 Ga would permit the use of positron emission tomography (PET), providing better resolution, sensitivity, and quantification accuracy than single-photon emission computed tomography (SPECT). The synthetic anti-HER2 Z HER2:S1 Affibody molecule was conjugated with DOTA at the N-terminus, in the middle of helix 3, or at the C-terminus. The biodistribution of 68 Ga- and 111 In-labeled Affibody molecules was directly compared in NMRI nu/nu mice bearing SKOV3 xenografts. The position of the chelator strongly influenced the biodistribution of the tracers, and the influence was more pronounced for 68 Ga-labeled Affibody molecules than for the 111 In-labeled counterparts. The best 68 Ga-labeled variant was 68 Ga-[DOTA-A1]-Z HER2:S1 which provided a tumor uptake of 13 ± 1 %ID/g and a tumor to blood ratio of 39 ± 12 at 2 hours after injection. 111 In-[DOTA-A 1 ]-Z HER2:S1 and 111 In-[DOTA-K 58 ]-Z HER2:S1 were equally good at this time point, providing a tumor uptake of 15 to 16 %ID/g and a tumor to blood ratio in the range of 60 to 80. In conclusion, the selection of the best position for a chelator in Affibody molecules can be used for optimization of their imaging properties. This may be important for the development of Affibody-based and other protein-based imaging probes

20 Years of Regulation and Policy under EO 12,898

Panel presentations and discussion on Executive Order 12,898--Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations. Panel I: 20 Years of Regulation and Policy under EO 12,898 Laura McKelvey -- Group Leader of Community and Tribal Programs, EPA; Charles Lee -- Deputy Associate Assistant Administrator of Environmental Justice, EPA; Amy Simes -- Liaison for Transportation at N.C. Dept. of Environ & Natural Resource