To assess the value of rescreening patients with Alzheimer's disease who do not meet the inclusion criteria for the Repeatable Battery for the Assessment of Neuropsychological Status Delayed Memory ...Index (RBANS DMI) at the initial assessment.
Participants (aged 50-85 years, without dementia, Mini-Mental State Examination score ≥22, valid Clinical Dementia Rating CDR global score, and amyloid status at baseline) were identified in the European Prevention of Alzheimer's Dementia database. Changes from baseline in RBANS DMI were estimated using a mixed model for repeated measurements. Logistic regressions were used to estimate the probability of participants with baseline RBANS DMI 86-95 having RBANS DMI ≤85, CDR global score ≥0.5, and amyloid positivity at 6 and 12 months.
There was significant variability in the change in RBANS DMI scores over time (median change at 6 months: 2.0). An estimated 15% of participants with RBANS DMI 86-95 at baseline progressed to ≤85 at 6 months; 8% also achieved CDR global score ≥0.5 and 5% were also amyloid positive.
The results from our analysis indicate that there is limited value in rescreening patients based on their initial RBANS DMI score.
The Geography of Chinese Science Andersson, David Emanuel; Gunessee, Saileshsingh; Matthiessen, Christian Wichmann ...
Environment and planning. A,
12/2014, Letnik:
46, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Chinese scientific output has increased dramatically in recent years, but its internal spatial structure has received scant attention. Estimated gravity models of intercity scientific coauthorships ...show that there are two types of spatial political bias in China, apart from the expected mass and distance effects. Intercity coauthorships involving Beijing are more common than Beijing's output volume and location would imply, and this Beijing bias is increasing over time. The second type of spatial political bias is greater intraprovincial collaboration than is accounted for by size and distance. The geography of Chinese science is thus not only monocentric as regards overall scientific output, but also exhibits unusually hierarchical collaboration patterns. Unlike in Europe and North America, national and regional capitals are becoming ever more important as scientific coordination centers.
Selective antibody targeted delivery of α particle emitting actinium-225 to tumors has significant therapeutic potential. This work highlights the design and synthesis of a new bifunctional ...macrocyclic diazacrown ether chelator, H
2
MacropaSqOEt, that can be conjugated to antibodies and forms stable complexes with actinium-225. The macrocyclic diazacrown ether chelator incorporates a linker comprised of a short polyethylene glycol fragment and a squaramide ester that allows selective reaction with lysine residues on antibodies to form stable vinylogous amide linkages. This new H
2
MacropaSqOEt chelator was used to modify a monoclonal antibody, girentuximab (hG250), that binds to carbonic anhydrase IX, an enzyme that is overexpressed on the surface of cancers such as clear cell renal cell carcinoma. This new antibody conjugate (H
2
MacropaSq-hG250) had an average chelator to antibody ratio of 4 : 1 and retained high affinity for carbonic anhydrase IX. H
2
MacropaSq-hG250 was radiolabeled quantitatively with
225
AcAc
III
within one minute at room temperature with micromolar concentrations of antibody and the radioactive complex is stable in human serum for >7 days. Evaluation of
225
AcAc(MacropaSq-hG250) in a mouse xenograft model, that overexpresses carbonic anhydrase IX, demonstrated a highly significant therapeutic response. It is likely that H
2
MacropaSqOEt could be used to modify other antibodies providing a readily adaptable platform for other actinium-225 based therapeutics.
Alpha particle therapy with an actinium-225 labelled antibody for carbonic anhydrase IX leads to a highly significant therapeutic response in a mouse xenograft model.
Numerous cell⁻cell and cell⁻matrix interactions within the bone marrow microenvironment enable the controlled lifelong self-renewal and progeny of hematopoietic stem and progenitor cells (HSPCs). On ...the cellular level, this highly mutual interaction is granted by cell adhesion molecules (CAMs) integrating differentiation, proliferation, and pro-survival signals from the surrounding microenvironment to the inner cell. However, cell⁻cell and cell⁻matrix interactions are also critically involved during malignant transformation of hematopoietic stem/progenitor cells. It has become increasingly apparent that leukemia-associated gene products, such as activated tyrosine kinases and fusion proteins resulting from chromosomal translocations, directly regulate the activation status of adhesion molecules, thereby directing the leukemic phenotype. These observations imply that interference with adhesion molecule function represents a promising treatment strategy to target pre-leukemic and leukemic lesions within the bone marrow niche. Focusing on myeloid leukemia, we provide a current overview of the mechanisms by which leukemogenic gene products hijack control of cellular adhesion to subsequently disturb normal hematopoiesis and promote leukemia development.
Oncogenic transcription factors such as the leukemic fusion protein RUNX1/ETO, which drives t(8;21) acute myeloid leukemia (AML), constitute cancer-specific but highly challenging therapeutic ...targets. We used epigenomic profiling data for an RNAi screen to interrogate the transcriptional network maintaining t(8;21) AML. This strategy identified Cyclin D2 (CCND2) as a crucial transmitter of RUNX1/ETO-driven leukemic propagation. RUNX1/ETO cooperates with AP-1 to drive CCND2 expression. Knockdown or pharmacological inhibition of CCND2 by an approved drug significantly impairs leukemic expansion of patient-derived AML cells and engraftment in immunodeficient murine hosts. Our data demonstrate that RUNX1/ETO maintains leukemia by promoting cell cycle progression and identifies G1 CCND-CDK complexes as promising therapeutic targets for treatment of RUNX1/ETO-driven AML.
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•An RNAi screen identifies CCND2 as a crucial transcriptional target of RUNX1/ETO•RUNX1/ETO promotes CCND2 expression by binding to an upstream element•CCND2 knockdown inhibits RUNX1/ETO-driven leukemic expansion in vitro and in vivo•RUNX1/ETO-expressing leukemic cells are highly sensitive to a CDK4/6 inhibitor
Using in vitro and in vivo screens to identify essential RUNX1/ETO transcriptional targets in AML, Martinez-Soria identify CCND2 as required for leukemia maintenance and self-renewal. Targeting this dependency using the CDK4/6 inhibitor palbociclib prolongs the survival of AML PDX models.
Positron emission tomography is the imaging modality of choice when it comes to the high sensitivity detection of key markers of thrombosis and inflammation, such as activated platelets. We, ...previously, generated a fluorine-18 labelled single-chain antibody (scFv) against ligand-induced binding sites (LIBS) on activated platelets, binding it to the highly abundant platelet glycoprotein integrin receptor IIb/IIIa. We used a non-site-specific bio conjugation approach with N-succinimidyl-4-18Ffluorobenzoate (S18FFB), leading to a mixture of products with reduced antigen binding. In the present study, we have developed and characterised a novel fluorine-18 PET radiotracer, based on this antibody, using site-specific bio conjugation to engineer cysteine residues with N-2-(4-18Ffluorobenzamido)ethylmaleimide (18FFBEM). ScFvanti-LIBS and control antibody mut-scFv, with engineered C-terminal cysteine, were reduced, and then, they reacted with N-2-(4-18Ffluorobenzamido)ethylmaleimide (18FFBEM). Radiolabelled scFv was injected into mice with FeCl3-induced thrombus in the left carotid artery. Clots were imaged in a PET MR imaging system, and the amount of radioactivity in major organs was measured using an ionisation chamber and image analysis. Assessment of vessel injury, as well as the biodistribution of the radiolabelled scFv, was studied. In the in vivo experiments, we found uptake of the targeted tracer in the injured vessel, compared with the non-injured vessel, as well as a high uptake of both tracers in the kidney, lung, and muscle. As expected, both tracers cleared rapidly via the kidney. Surprisingly, a large quantity of both tracers was taken up by organs with a high glutathione content, such as the muscle and lung, due to the instability of the maleimide cysteine bond in vivo, which warrants further investigations. This limits the ability of the novel antibody radiotracer 18F-scFvanti-LIBS to bind to the target in vivo and, therefore, as a useful agent for the sensitive detection of activated platelets. We describe the first fluorine-18 variant of the scFvanti-LIBS against activated platelets using site-specific bio conjugation.
Hemato-oncological diseases account for nearly 10% of all malignancies and can be classified into leukemia, lymphoma, myeloproliferative diseases, and myelodysplastic syndromes. The causes and ...prognosis of these disease entities are highly variable. Most entities are not permanently controllable and ultimately lead to the patient's death. At the molecular level, recurrent mutations including chromosomal translocations initiate the transformation from normal stem-/progenitor cells into malignant blasts finally floating the patient's bone marrow and blood system. In acute myeloid leukemia (AML), the so-called master transcription factors such as RUNX1, KMT2A, and HOX are frequently disrupted by chromosomal translocations, resulting in neomorphic oncogenic fusion genes. Triggering ex vivo expansion of primary human CD34+ stem/progenitor cells represents a distinct characteristic of such chimeric AML transcription factors. Regarding oncogenic mechanisms of AML, most studies focus on murine models. However, due to biological differences between mice and humans, findings are only partly transferable. This review focuses on the genetic manipulation of human CD34+ primary hematopoietic stem/progenitor cells derived from healthy donors to model acute myeloid leukemia cell growth. Analysis of defined single- or multi-hit human cellular AML models will elucidate molecular mechanisms of the development, maintenance, and potential molecular intervention strategies to counteract malignant human AML blast cell growth.
89Zr-labelled proteins are gaining importance in clinical research in a variety of diseases. To date, no clinical study has been reported that utilizes an automated approach for radiosynthesis of ...89Zr-labelled radiopharmaceuticals. We aim to develop an automated method for the clinical production of 89Zr-labelled proteins and apply this method to Durvalumab, a monoclonal antibody targeting PD-L1 immune-checkpoint protein. PD-L1 expression is poorly understood and can be up-regulated over the course of chemo- and radiotherapy treatment. The ImmunoPET multicentre study aims to examine the dynamics of PD-L1 expression via 89Zr-Durvalumab PET imaging before, during, and after chemoradiotherapy. The developed automated technique will enable reproducible clinical production of 89ZrZr-DFOSq-Durvalumab for this study at three different sites.
Conjugation of Durvalumab to H3DFOSqOEt was optimized for optimal chelator-to-antibody ratio. Automated radiolabelling of H3DFOSq-Durvalumab with zirconium-89 was optimized on the disposable cassette based iPHASE technologies MultiSyn radiosynthesizer using a modified cassette. Activity losses were tracked using a dose calibrator and minimized by optimizing fluid transfers, reaction buffer, antibody formulation additives and pH. The biological profile of the radiolabelled antibody was confirmed in vivo in PD-L1+ (HCC827) and PD-L1- (A549) murine xenografts. Clinical process validation and quality control were performed at three separate study sites to satisfy clinical release criteria.
H3DFOSq-Durvalumab with an average CAR of 3.02 was obtained. Radiolabelling kinetics in succinate (20 mM, pH 6) were significantly faster when compared to HEPES (0.5 M, pH 7.2) with >90 % conversion observed after 15 min. Residual radioactivity in the 89Zr isotope vial was reduced from 24 % to 0.44 % ± 0.18 % (n = 7) and losses in the reactor vial were reduced from 36 % ± 6 % (n = 4) to 0.82 % ± 0.75 % (n = 4) by including a surfactant in the reaction and formulation buffers. Overall process yield was 75 % ± 6 % (n = 5) and process time was 40 min. Typically, 165 MBq of 89ZrZr-DFOSq-Durvalumab with an apparent specific activity of 315 MBq/mg ± 34 MBq/mg (EOS) was obtained in a volume of 3.0 mL. At end-of-synthesis (EOS), radiochemical purity and protein integrity were always >99 % and >96 %, respectively, and dropped to 98 % and 65 % after incubation in human serum for 7 days at 37 °C. Immunoreactive fraction in HEK293/PD-L1 cells was 83.3 ± 9.0 (EOS). Preclinical in vivo data at 144 h p.i. showed excellent SUVmax in PD-L1+ tumour (8.32 ± 0.59) with a tumour-background ratio of 17.17 ± 3.96. 89ZrZr-DFOSq-Durvalumab passed all clinical release criteria at each study site and was deemed suitable for administration in a multicentre imaging trial.
Fully automated production of 89ZrZr-DFOSq-Durvalumab for clinical use was achieved with minimal exposure to the operator. The cassette-based approach allows for consecutive productions on the same day and offers an alternative to currently used manual protocols. The method should be broadly applicable to other proteins and has the potential for clinical impact considering the growing number of clinical trials investigating 89Zr-labelled antibodies.
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Prostate‐specific membrane antigen (PSMA)‐targeted imaging and therapy of prostate cancer using theranostic pairs is rapidly changing clinical practice. To facilitate clinical trials, fully automated ...procedures for the radiosyntheses of 68GaGa‐PSMA‐11 and 177LuLu‐PSMA‐617 were developed from commercially available precursors using the cassette based iPHASE MultiSyn module. Formulated and sterile radiopharmaceuticals were obtained in 76 ± 3% (n = 20) and 91 ± 4% (n = 15) radiochemical yields after 17 and 20 min, respectively. Radiochemical purity was always >95% and molar activities exceeded 792 ± 100 and 88 ± 6 GBq/μmol, respectively. Quality control showed conformity with all relevant release criteria and radiopharmaceuticals were used in the clinic.
Methods for the fully automated production of a relevant theranostic pair of prostate‐specific membrane antigen (PSMA)‐targeting molecules are described. Quality control parameters and test results for clinical application are presented and the performance of the procedures is compared other reported protocols.
Chimeric transcription factors are a hallmark of human leukemia, but the molecular mechanisms by which they block differentiation and promote aberrant self-renewal remain unclear. Here, we ...demonstrate that the ETO2-GLIS2 fusion oncoprotein, which is found in aggressive acute megakaryoblastic leukemia, confers megakaryocytic identity via the GLIS2 moiety while both ETO2 and GLIS2 domains are required to drive increased self-renewal properties. ETO2-GLIS2 directly binds DNA to control transcription of associated genes by upregulation of expression and interaction with the ETS-related ERG protein at enhancer elements. Importantly, specific interference with ETO2-GLIS2 oligomerization reverses the transcriptional activation at enhancers and promotes megakaryocytic differentiation, providing a relevant interface to target in this poor-prognosis pediatric leukemia.
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•The GLIS2 moiety of ETO2-GLIS2 oncoprotein controls the megakaryocytic identity•Human AMKL oncogenes often cause GATA/ETS functional imbalance•ETO2-GLIS2 binds enhancer regions together with the ERG transcription factor•The NHR2 interface is essential for maintenance of ETO2-GLIS2-driven leukemia
Thirant et al. show that the ETO2-GLIS2 fusion protein found in acute megakaryoblastic leukemia confers megakaryocytic identity via the GLIS2 moiety, but requires both ETO2 and GLIS2 domains to drive self-renewal. Disruption of ETO2-GLIS2 oligomerization inhibits the maintenance of ETO2-GLIS2+ human AMKL blasts.
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