1,728,553 research outputs found
Targeting of immune checkpoint regulator V-domain Ig suppressor of T-cell activation (VISTA) with 89Zr-labelled CI-8993
No full textBACKGROUND: CI-8993 is a fully human IgG1κ monoclonal antibody (mAb) that binds specifically to immune checkpoint molecule VISTA (V-domain Ig suppressor of T-cell activation). Phase I safety has been established in patients with advanced cancer (NCT02671955). To determine the pharmacokinetics and biodistribution of CI-8993 in patients, we aimed to develop 89Zr-labelled CI-8993 and validate PET imaging and quantitation in preclinical models prior to a planned human bioimaging trial. METHODS: CI-8993 and human isotype IgG1 control were conjugated to the metal ion chelator p-isothiocyanatobenzyl-desferrioxamine (Df). Quality of conjugates were assessed by SE-HPLC, SDS-PAGE, and FACS. After radiolabelling with zirconium-89 (89Zr), radioconjugates were assessed for radiochemical purity, immunoreactivity, antigen binding affinity, and serum stability in vitro. [89Zr]Zr-Df-CI-8993 alone (1 mg/kg, 4.6 MBq) or in combination with 30 mg/kg unlabelled CI-8993, as well as isotype control [89Zr]Zr-Df-IgG1 (1 mg/kg, 4.6 MBq) were assessed in human VISTA knock-in female (C57BL/6 N-Vsirtm1.1(VSIR)Geno, huVISTA KI) or control C57BL/6 mice bearing syngeneic MB49 bladder cancer tumours; and in BALB/c nu/nu mice bearing pancreatic Capan-2 tumours. RESULTS: Stable constructs with an average chelator-to-antibody ratio of 1.81 were achieved. SDS-PAGE and SE-HPLC showed integrity of CI-8993 was maintained after conjugation; and ELISA indicated no impact of conjugation and radiolabelling on binding to human VISTA. PET imaging and biodistribution in MB49 tumour-bearing huVISTA KI female mice showed specific localisation of [89Zr]Zr-Df-CI-8993 to VISTA in spleen and tumour tissues expressing human VISTA. Specific tumour uptake was also demonstrated in Capan-2 xenografted BALB/c nu/nu mice. CONCLUSIONS: We radiolabelled and validated [89Zr]Zr-Df-CI-8993 for specific binding to huVISTA in vivo. Our results demonstrate that 89Zr-labelled CI-8993 is now suitable for targeting and imaging VISTA expression in human trials
Town houses, Lot 8993, Ellengowan Drive, Brinkin
No full textTown houses, Lot 8993, Ellengowan Drive, Brinkin. Selling agents Key. "Brinkin Court." Buildings still under construction.Mannix, Ian.Date:198
324 Preclinical evaluation of anti-VISTA antibody CI-8993 in a syngeneic huVISTA-KI model
No full textVISTA (V-domain Ig suppressor of T-cell activation) inhibits anti-tumour immune responses. The Investigational product CI-8993 is a fully human IgG1k monoclonal antibody that binds specifically to this immune checkpoint molecule. Phase I safety has been established in prior trials in patients with advanced cancer (NCT02671955). To assist determining the pharmacokinetics and biodistribution of CI-8993 in patients we aimed to develop a Zirconium-89 (89Zr)-labelled CI-8993 for PET imaging and quantitation, and validate in preclinical models prior to a planned human trial. Conjugation conditions of CI-8993 to the metal ion chelator desferrioxamine B (Df-) were established by optimisation of Df:mAb ratio, reaction temperature, time and purification method. Conjugates were assessed by SE-HPLC, SDS-PAGE, and ELISA. Radiolabelling was performed with 89Zr and the radioconjugate was tested for specific activity, radiochemical purity and binding affinity for huVISTA. The in-vivo biodistribution and properties of 89Zr-Df-CI-8993 and IgG1 isotype control radioconjugates were assessed in huVISTA knock-in female (C57BL/6N-Vsirtm1.1(VSIR)Geno) or control C57BL/6 mice bearing syngeneic MB49 bladder cancer tumours. Whole body animal PET/CT imaging was performed on day of radioconjugate synthesis and injection and day 1 and day 3 p.i. Biodistribution was assessed by image analyses, and tissue counting, with IHC analyses performed to verify VISTA antigen expression. Conjugation of Df- to CI-8993 for 60 minutes at room temperature followed by purification via gel filtration resulted in stable constructs with an average chelator-to-antibody ratio of 1.81. SDS-PAGE showed integrity of CI-8993 was maintained after conjugation, and ELISA indicated no impact of conjugation on binding to human VISTA. Radiochemical purity (iTLC) and protein integrity (SE-HPLC) at EOS were > 99% and 93%. PET imaging and biodistribution in MB49 tumour-bearing huVISTA knock-in female mice showed specific localisation of 89Zr-Df-CI-8993 to VISTA expressing organs (liver: 14.98 ± 0.50 %ID/g; spleen: 292.00 ± 14.51 %ID/g; n = 3) compared to 89Zr-Df-IgG1 control (liver: 4.615 ± 0.15 %ID/g; spleen: 6.37 ± 0.22 %ID/g; n = 4) or in the presence of competing unlabelled CI-8993 (liver: 8.14 ± 0.50 %ID/g; spleen: 41.14 ± 3.00 %ID/g; n = 5). Tumour-to-blood ratios indicated specific tumour targeting of 89Zr-Df-CI-8993 in the presence of unlabelled CI-8993 (20.47 ± 3.09) compared to trace dose 89Zr-Df-CI-8993 (0.97 ± 0.12; P = 0.0001) or 89Zr-Df-IgG1 control (1.75 ± 0.11; P < 0.0001). We have validated 89Zr-Df-CI-8993 for specific binding to huVISTA in-vivo. A clinical trial of 89Zr-Df-CI-8993 is planned in solid tumour patients. All animal studies were approved by the Austin Health Animal Ethics Committee and were conducted in compliance with the Australian Code for the care anduse of animals for scientific purposes
Mitochondrial DNA mutations at nucleotide 8993 show a lack of tissue- or age-related variation
No full textTwo pathogenic mitochondrial DNA mutations, a T-to-G substitution (8993T > G) and a T-to-C substitution (8993T > C), at nucleotide 8993 have been reported. We describe 13 pedigrees with mitochondrial DNA mutations at nucleotide 8993; 10 pedigrees with the 8993T > G mutation and three with the 8993T > C mutation. Prenatal diagnosis of the nucleotide 8993 mutations is technically possible. However, there are three major concerns: (i) that there is variation in mutant loads among tissues; (ii) that the mutant load in a tissue may change over time; and (iii) that the genotype-phenotype correlation is not clearly understood. We have used the 13 pedigrees to determine specifically the extent of tissue- and age-related variation of the two mutations at nucleotide 8993 in the mitochondrial DNA. The tissue variation was investigated by analysing two or more different tissues from a total of 18 individuals. The age-related variation of the mutation was investigated by comparing the amount of both mutations in blood taken at birth and at a later age. No substantial tissue variation was found, nor was there any substantial change in the proportion of either mutation over periods of 8-23 years in the four individuals studied. In addition, we noted that two features were remarkably common in families with nucleotide 8993 mutations, namely (i) unexplained infant death (8 cases in 13 pedigrees), and (ii) de novo mutations (5 of the 10 8993T > G pedigrees)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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