Preclinical Testing of Radiopharmaceuticals for the Detection and Characterization of Osteomyelitis: Experiences from a Porcine Model

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.

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Preclinical characterization of dostarlimab, a therapeutic anti-PD-1 antibody with potent activity to enhance immune function in in vitro cellular assays and in vivo animal models

mAbs ◽

10.1080/19420862.2021.1954136 ◽

2021 ◽

Vol 13 (1) ◽

pp. 1954136

Author(s):

Sujatha Kumar ◽

Srimoyee Ghosh ◽

Geeta Sharma ◽

Zebin Wang ◽

Marilyn R. Kehry ◽

...

Keyword(s):

Animal Models ◽

Immune Function ◽

Cellular Assays ◽

In Vivo Animal Models

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Animal Models in the Evaluation of the Effectiveness of Phage Therapy for Infections Caused by Gram-Negative Bacteria from the ESKAPE Group and the Reliability of Its Use in Humans

Microorganisms ◽

10.3390/microorganisms9020206 ◽

2021 ◽

Vol 9 (2) ◽

pp. 206

Author(s):

Martyna Cieślik ◽

Natalia Bagińska ◽

Andrzej Górski ◽

Ewa Jończyk-Matysiak

Keyword(s):

Animal Models ◽

Phage Therapy ◽

Animal Experiments ◽

Species Group ◽

Effectiveness Evaluation ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Enterobacter Species ◽

The Individual

The authors emphasize how extremely important it is to highlight the role played by animal models in an attempt to determine possible phage interactions with the organism into which it was introduced as well as to determine the safety and effectiveness of phage therapy in vivo taking into account the individual conditions of a given organism and its physiology. Animal models in which phages are used make it possible, among other things, to evaluate the effective therapeutic dose and to choose the possible route of phage administration depending on the type of infection developed. These results cannot be applied in detail to the human body, but the knowledge gained from animal experiments is invaluable and very helpful. We would like to highlight how useful animal models may be for the possible effectiveness evaluation of phage therapy in the case of infections caused by gram-negative bacteria from the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species) group of pathogens. In this review, we focus specifically on the data from the last few years.

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Establishment and Characterization of a Reliable Xenograft Model of Hodgkin Lymphoma Suitable for the Study of Tumor Origin and the Design of New Therapies

Cancers ◽

10.3390/cancers10110414 ◽

2018 ◽

Vol 10 (11) ◽

pp. 414 ◽

Cited By ~ 3

Author(s):

Radhia M’kacher ◽

Monika Frenzel ◽

Mustafa Al Jawhari ◽

Steffen Junker ◽

Corina Cuceu ◽

...

Keyword(s):

Animal Model ◽

Histone Deacetylase ◽

High Frequency ◽

Histone Deacetylase Inhibitor ◽

Telomerase Activity ◽

Nsg Mice ◽

Deacetylase Inhibitor

To identify the cells responsible for the initiation and maintenance of Hodgkin lymphoma (HL) cells, we have characterized a subpopulation of HL cells grown in vitro and in vivo with the aim of establishing a reliable and robust animal model for HL. To validate our model, we challenged the tumor cells in vivo by injecting the alkylating histone-deacetylase inhibitor, EDO-S101, a salvage regimen for HL patients, into xenografted mice. Methodology: Blood lymphocytes from 50 HL patients and seven HL cell lines were used. Immunohistochemistry, flow cytometry, and cytogenetics analyses were performed. The in vitro and in vivo effects of EDO-S101 were assessed. Results: We have successfully determined conditions for in vitro amplification and characterization of the HL L428-c subline, containing a higher proportion of CD30−/CD15− cells than the parental L428 cell line. This subline displayed excellent clonogenic potential and reliable reproducibility upon xenografting into immunodeficient NOD-SCID-gamma (−/−)(NSG) mice. Using cell sorting, we demonstrate that CD30−/CD15− subpopulations can gain the phenotype of the L428-c cell line in vitro. Moreover, the human cells recovered from the seventh week after injection of L428-c cells into NSG mice were small cells characterized by a high frequency of CD30−/CD15− cells. Cytogenetic analysis demonstrated that they were diploid and showed high telomere instability and telomerase activity. Accordingly, chromosomal instability emerged, as shown by the formation of dicentric chromosomes, ring chromosomes, and breakage/fusion/bridge cycles. Similarly, high telomerase activity and telomere instability were detected in circulating lymphocytes from HL patients. The beneficial effect of the histone-deacetylase inhibitor EDO-S101 as an anti-tumor drug validated our animal model. Conclusion: Our HL animal model requires only 103 cells and is characterized by a high survival/toxicity ratio and high reproducibility. Moreover, the cells that engraft in mice are characterized by a high frequency of small CD30−/CD15− cells exhibiting high telomerase activity and telomere dysfunction.

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Genotypic characterization of two bacterial artificial chromosome clones derived from a single DNA source of the very virulent gallid herpesvirus-2 strain C12/130

Journal of General Virology ◽

10.1099/vir.0.027706-0 ◽

2011 ◽

Vol 92 (7) ◽

pp. 1500-1507 ◽

Cited By ~ 17

Author(s):

Stephen J. Spatz ◽

Lorraine P. Smith ◽

Susan J. Baigent ◽

Lawrence Petherbridge ◽

Venugopal Nair

Keyword(s):

Bacterial Artificial Chromosome ◽

Artificial Chromosome ◽

Genetic Changes ◽

Mixed Genotype ◽

Bac Clones ◽

Gallid Herpesvirus 2 ◽

The Individual

The identification of specific genetic changes associated with differences in the pathogenicity of Marek's disease virus strains (GaHV-2) has been a formidable task due to the large number of mutations in mixed-genotype populations within DNA preparations. Very virulent UK isolate C12/130 induces extensive lymphoid atrophy, neurological manifestations and early mortality in young birds. We have recently reported the construction of several independent full-length bacterial artificial chromosome (BAC) clones of C12/130 capable of generating fully infectious viruses with significant differences in their pathogenicity profiles. Two of these clones (vC12/130-10 and vC12/130-15), which showed differences in virulence relative to each other and to the parental strain, had similar replication kinetics both in vitro and in vivo in spite of the fact that vC12/130-15 was attenuated. To investigate the possible reasons for this, the nucleotide sequences of both clones were determined. Sequence analysis of the two genomes identified mutations within eight genes. A single 494 bp insertion was identified within the genome of the virulent vC12/130-10 clone. Seven non-synonymous substitutions distinguished virulent vC12/130-10 from that of attenuated vC12/130-15. By sequencing regions of parental DNA that differed between the two BAC clones, we confirmed that C12/130 does contain these mutations in varying proportions. Since the individual reconstituted BAC clones were functionally attenuated in vivo and derived from a single DNA source of phenotypically very virulent C12/130, this suggests that the C12/130 virus population exists as a collection of mixed genotypes.

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Concentration-Dependent Selection of Small Phenotypic Differences in TEM β-Lactamase-Mediated Antibiotic Resistance

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.9.2485-2491.2000 ◽

2000 ◽

Vol 44 (9) ◽

pp. 2485-2491 ◽

Cited By ~ 89

Author(s):

Maria-Cristina Negri ◽

Marc Lipsitch ◽

Jesús Blázquez ◽

Bruce R. Levin ◽

Fernando Baquero

Keyword(s):

Amino Acid Replacement ◽

Single Amino Acid ◽

Chromosomal Marker ◽

Beta Lactamase ◽

Antibiotic Resistant ◽

Phenotypic Differences ◽

The Individual ◽

Selection Of

ABSTRACT In this paper, the first robust experimental evidence of in vitro and in vivo concentration-dependent selection of low-level antibiotic-resistant genetic variants is described. The work is based on the study of an asymmetric competition assay with pairs of isogenicEscherichia coli strains, differing only (apart from a neutral chromosomal marker) in a single amino acid replacement in a plasmid-mediated TEM-1 beta-lactamase enzyme, which results in the new TEM-12 beta-lactamase. The mixture was challenged by different antibiotic concentrations, both in vitro and in the animal model, and the selective process of the variant population was carefully monitored. A mathematical model was constructed to test the hypothesis that measured growth and killing rates of the individual TEM variants at different antibiotic concentrations could be used to predict quantitatively the strength of selection for TEM-12 observed in competition experiments at these different concentrations.

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Identification of a Chromosome-Targeting Domain in the Human Condensin Subunit CNAP1/hCAP-D2/Eg7

Molecular and Cellular Biology ◽

10.1128/mcb.22.16.5769-5781.2002 ◽

2002 ◽

Vol 22 (16) ◽

pp. 5769-5781 ◽

Cited By ~ 33

Author(s):

Alexander R. Ball, ◽

John A. Schmiesing ◽

Changcheng Zhou ◽

Heather C. Gregson ◽

Yoshiaki Okada ◽

...

Keyword(s):

Mitotic Chromosome ◽

Mitotic Chromosomes ◽

Family Protein ◽

Localization Signal ◽

The Individual ◽

Mitotic Chromosome Condensation ◽

Structural Maintenance Of Chromosomes

ABSTRACT CNAP1 (hCAP-D2/Eg7) is an essential component of the human condensin complex required for mitotic chromosome condensation. This conserved complex contains a structural maintenance of chromosomes (SMC) family protein heterodimer and three non-SMC subunits. The mechanism underlying condensin targeting to mitotic chromosomes and the role played by the individual condensin components, particularly the non-SMC subunits, are not well understood. We report here characterization of the non-SMC condensin component CNAP1. CNAP1 contains two separate domains required for its stable incorporation into the complex. We found that the carboxyl terminus of CNAP1 possesses a mitotic chromosome-targeting domain that does not require the other condensin components. The same region also contains a functional bipartite nuclear localization signal. A mutant CNAP1 missing this domain, although still incorporated into condensin, was unable to associate with mitotic chromosomes. Successful chromosome targeting of deletion mutants correlated with their ability to directly bind to histones H1 and H3 in vitro. The H3 interaction appears to be mediated through the H3 histone tail, and a subfragment containing the targeting domain was found to interact with histone H3 in vivo. Thus, the CNAP1 C-terminal region defines a novel histone-binding domain that is responsible for targeting CNAP1, and possibly condensin, to mitotic chromosomes.

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