A bispecific antibody NXT007 exerts a hemostatic activity in hemophilia A monkeys enough to keep a nonhemophilic state.

Background: Emicizumab, a factor (F) VIIIa-function mimetic bispecific antibody (BsAb) to FIXa and FX, has become an indispensable treatment option for people with hemophilia A (PwHA). However, a small proportion of PwHA still experience bleeds even under emicizumab prophylaxis, as observed in the long-term outcomes of clinical studies. A more potent BsAb may be desirable for such patients.

Standard protocol for the PIGRET assay, a high-throughput reticulocyte Pig-a assay with an immunomagnetic separation, used in the interlaboratory trial organized by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen and Genome Society.

The PIGRET assay is one of the Pig-a assays targeting reticulocytes (RETs), an in vivo genotoxicity evaluation method using flow cytometry with endogenous reporter glycosylphosphatidylinositol anchor protein. The PIGRET assay with RETs selectively enriched with anti-CD71 antibodies has several desirable features: high-throughput assay system, low background frequency of mutant cells, and early detection of mutation. To verify the potential and usefulness of the PIGRET assay for short-term testing, an interlaboratory trial involving 16 laboratories organized by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen and Genome Society was conducted.

Standard protocol for the total red blood cell assay used in the interlaboratory trial organized by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen Society.

The assay, a promising tool for evaluating in vivo genotoxicity, is based on flow cytometric enumeration of red blood cells (RBCs) that are deficient in glycosylphosphatidylinositol anchor protein. Various approaches for measuring mutant cells have been developed, particularly focusing on measuring mutants in peripheral RBCs and reticulocytes (RETs). The assay on concentrated RETs-the PIGRET assay-has the potential to detect genotoxicity in the early stages of a study.

Evaluation for a mutagenicity of aristolochic acid by Pig-a and PIGRET assays in rats.

The Pig-a assay, which uses the endogenous phosphatidylinositol glycan, class A gene (Pig-a) as a reporter of mutation, has been developed as a method for evaluating in vivo mutagenicity. Pig-a gene mutation can be detected by identifying the presence of CD59, the glycosylphosphatidylinositol anchor protein, on the surface of erythrocytes (RBC Pig-a assay) and reticulocytes (PIGRET assay). The International Workshop on Genotoxicity Testing (IWGT) showed the usefulness of the RBC Pig-a assay through the evaluation of several compounds.

Evaluation of the PIGRET assay in rats by single oral dosing with azidothymidine.

In vivo phosphatidylinositol glycan, class A (Pig-a) gene mutation assay using peripheral blood is known to be a novel and useful tool to evaluate the mutagenicity of compounds. Recently, the rat PIGRET assay which is an improved method for measuring Pig-a mutant cells in reticulocytes with magnetic enrichment of CD71 positive cells has been developed. Several reports showed that the PIGRET assay could detect the increase of Pig-a mutant frequency earlier than the Pig-a assay in total red blood cells (RBC Pig-a assay).

The PIGRET assay, a method for measuring Pig-a gene mutation in reticulocytes, is reliable as a short-term in vivo genotoxicity test: Summary of the MMS/JEMS-collaborative study across 16 laboratories using 24 chemicals.

The in vivo mutation assay using the X-linked phosphatidylinositol glycan class A gene (Pig-a in rodents, PIG-A in humans) is a promising tool for evaluating the mutagenicity of chemicals. Approaches for measuring Pig-a mutant cells have focused on peripheral red blood cells (RBCs) and reticulocytes (RETs) from rodents. The recently developed PIGRET assay is capable of screening >1×10 RETs for Pig-a mutants by concentrating RETs in whole blood prior to flow cytometric analysis.

Repeated-dose liver micronucleus test of 4,4'-methylenedianiline using young adult rats.

Liver micronucleus (MN) tests using partial hepatectomized rats or juvenile rats have been shown to be useful for the detection of hepatic carcinogens. Moreover, Narumi et al. established the repeated-dose liver MN test using young adult rats for integration into general toxicity.

Evaluation of the repeated-dose liver and gastrointestinal tract micronucleus assays with 22 chemicals using young adult rats: summary of the collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/The Japanese Environmental Mutagen Society (JEMS) - Mammalian Mutagenicity Study Group (MMS).

The repeated-dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect hepatocarcinogens. We conducted a collaborative study to assess the performance of this assay and to evaluate the possibility of integrating it into general toxicological studies. Twenty-four testing laboratories belonging to the Mammalian Mutagenicity Study Group, a subgroup of the Japanese Environmental Mutagen Society, participated in this trial.

Nonclinical safety assessment of Efinaconazole Solution (10%) for onychomycosis treatment.

Efinaconazole is a triazole developed as a 10% solution for topical treatment of onychomycosis, a common fungal nail infection. Efinaconazole solution and topical formulation vehicle administered dermally to mice (13weeks), rats (6months) and minipigs (9months) produced transient erythema, minimal to modest hyperkeratosis, and mild microscopic skin inflammation. The liver was the target organ of systemic toxicity; reversible, minimal to moderate vacuolated changes were noted in the rat dermal study at 15 and 50mg/kg/day.

Discrimination of genotoxic and non-genotoxic hepatocarcinogens by statistical analysis based on gene expression profiling in the mouse liver as determined by quantitative real-time PCR.

The general aim of the present study is to discriminate between mouse genotoxic and non-genotoxic hepatocarcinogens via selected gene expression patterns in the liver as analyzed by quantitative real-time PCR (qPCR) and statistical analysis. qPCR was conducted on liver samples from groups of 5 male, 9-week-old B6C3F(1) mice, at 4 and 48h following a single intraperitoneal administration of chemicals. We quantified 35 genes selected from our previous DNA microarray studies using 12 different chemicals: 8 genotoxic hepatocarcinogens (2-acetylaminofluorene, 2,4-diaminotoluene, diisopropanolnitrosamine, 4-dimethylaminoazobenzene, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, N-nitrosomorpholine, quinoline and urethane) and 4 non-genotoxic hepatocarcinogens (1,4-dichlorobenzene, dichlorodiphenyltrichloroethane, di(2-ethylhexyl)phthalate and furan).

Changes in expression of hepatic cytochrome P450 subfamily enzymes during development of adjuvant-induced arthritis in rats.

An animal model of rheumatoid arthritis can be elicited in male Lewis rats by a single intradermal injection of liquid paraffin containing dead Mycrobacterium tuberculosis (MT adjuvant) into the planar surface of the right hind-foot. In the present study, we used this animal model to examine the changes in expression of hepatic cytochorme P450 (CYP) enzymes during the development of the arthritis. Swellings of the MT adjuvant-injected hind-foot initially occurred at 1-8 days after the injection.

Integration of in vivo genotoxicity and short-term carcinogenicity assays using F344 gpt delta transgenic rats: in vivo mutagenicity of 2,4-diaminotoluene and 2,6-diaminotoluene structural isomers.

An important trend in current toxicology is the replacement, reduction, and refinement of the use of experimental animals (the 3R principle). We propose a model in which in vivo genotoxicity and short-term carcinogenicity assays are integrated with F344 gpt delta transgenic rats. Using this model, the genotoxicity of chemicals can be identified in target organs using a shuttle vector lambda EG10 that carries reporter genes for mutations; short-term carcinogenicity is determined by the formation of glutathione S-transferase placenta form (GST-P) foci in the liver.

Inhibitory effects of antiparkinsonian drugs and caspase inhibitors in a parkinsonian flatworm model.

It has been known that rotenone and 1-methyl-4-phenylpyridinium ion (MPP(+), a metabolite of MPTP), which inhibit mitochondrial complex I, are useful tools for parkinsonian models in vertebrates such as primates and rodents. Planarian, an invertebrate flatworm, has a high potential for regeneration, and dopamine plays a key role in its behavior. In the present study, we examined a cloned planarian, the GI strain from Dugesia japonica.