The predictivity of preliminary embryo-fetal development (EFD) studies: results of a retrospective survey in Japanese pharmaceutical companies.

To explore the predictivity of dose range-finding (DRF) studies, we conducted asurvey by sending out questionnaires to 72 Japanese pharmaceutical companies.The survey yielded data for 108 and 85 compounds for which any embryo-fetaldevelopment (EFD) toxicities were observed in the definitive studies in rodentsand non-rodents, respectively. As a result of the analysis, 83% of studies inrodents and 80% in non-rodents showed EFD effects in the DRF studies.

Collaborative work on evaluation of ovarian toxicity by repeated-dose and fertility studies in female rats.

The National Institute of Health Sciences (NIHS) and 18 pharmaceutical companies of the Japan Pharmaceutical Manufacturers Association (JPMA) have conducted a validation study intended to evaluate whether a 2-week repeated general toxicity period with histopathological examination is sufficient to detect ovarian toxicity or not. The current repeated dose general toxicity study is considered to be insufficient in terms of evaluating female reproductive function due to a lack of evidence indicating that it is adequate. Evaluation of ovarian toxicity by comprehensive histopathological examination of the female reproductive organs based on the underlying morphology of a normal cycle of the reproductive tract including the ovary and additional immunohistochemical staining with proliferative cell nuclear antigen (PCNA) to identify small follicles may be a good tool to assess female reproductive function.

Safety assessment of biopharmaceuticals: Japanese perspective on ICH S6 guideline maintenance.

Safety assessment of biopharmaceuticals in preclinical studies is guided by the ICH S6 guideline issued in 1997. Along with enormous experiences and knowledge on safety assessment of some classes of biopharmaceuticals over the last decade, the necessity and feasibility of updating the guideline has been discussed. According to a recommendation by safety experts at the ICH meeting in Chicago in 2006, regional discussions of ICH S6 were held in the USA, EU and Japan.

Points to consider on the non-clinical safety evaluation of anticancer drugs.

Since malignant tumors are life-threatening, the death rate from these diseases is high, and existing therapies have limited effectiveness, it is desired to provide new effective anticancer drugs to tumor patients sooner. However, there is no guideline regarding non-clinical safety studies on the development of anticancer drugs required for the first in human clinical trials and for the approval applications in Japan. Then, the Ministry of Health, Labour and Welfare (MHLW) established the collaboration group including regulatory, academic and industrial scientists to prepare the guideline on the non-clinical safety evaluation of anticancer drugs in 2004.

Current opinion: safety evaluation of drug metabolites in development of pharmaceuticals.

Safety assessment of drug metabolites in the development of pharmaceuticals was discussed in January 2007 at the kick-off meeting of a "Drug Evaluation Forum", with reference to the views of clinicians and other academic representatives. Safety evaluation of metabolites cannot readily be based on a single theoretical framework, and basically a case-by-case approach is called for. These evaluations should be performed precisely and an accurate profile secured taking into account adverse reactions that are unpredictable from the parent compound administered in clinical studies and any signs or symptoms that may be associated with the metabolites.

"Points to consider" regarding safety assessment of biotechnology-derived pharmaceuticals in non-clinical studies (English translation).

Regulatory and industrial scientists collaborated to publish a "points to consider" document regarding the safety assessment of biotechnology-derived pharmaceuticals in non-clinical studies in 2002 (Pharmaceutical Non-clinical Investigation Group, 2002). The collaboration team intended to clarify the interpretation of ICH-S6 guideline and furthermore share recent Japanese practices on this matter. However, the document was written in Japanese.

Studies on experimental iodine allergy: 3. Low molecular weight elicitogenic antigens of iodine allergy.

We hypothesize that iodine allergy is an immune response to iodinated self proteins produced in vivo from various iodine-containing chemicals. Since an antigenic determinant of experimental iodine allergy is diiodotyrosine (DIT), we designed low molecular weight DIT derivatives having provocative antigenicity without sensitizing immunogenicity. Tetraiododityrosine and hexaiodotrityrosine provoked dose-dependent skin reactions in guinea pigs previously immunized with iodine.

Studies on experimental iodine allergy: 2. Iodinated protein antigens and their generation from inorganic and organic iodine-containing chemicals.

We hypothesize that iodine allergy is an immune response to iodinated autologous proteins generated in vivo from iodine-containing organic and inorganic chemicals. In this report, effects of protein iodination on elicitogenic activity in guinea pig iodine allergy model and iodinated protein antigen generation in vitro from iodine-containing chemicals were investigated. Active cutaneous anaphylaxis (ACA) and delayed-type hypersensitivity (DTH) tests were performed in guinea pigs immunized with iodine.

Studies on experimental iodine allergy: 1. Antigen recognition of guinea pig anti-iodine antibody.

It has generally been thought that iodine allergy is cross-sensitive to various iodine-containing chemicals. However, this concept seems to deviate from the immunological principle that immune recognition is specific. To solve this contradiction, we hypothesize that iodine allergy is an immunological reaction to iodinated autologous proteins produced in vivo by iodination reaction from various iodine-containing chemicals.

Use of human liver S9 in the Ames test: assay of three procarcinogens using human S9 derived from multiple donors.

The purpose of the present study was to examine the inter-individual variation in the mutagenicity of chemicals using a variety of human S9 fractions. For this purpose, three procarcinogens, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), benzo[a]pyrene (BP), and dimethylnitrosamine (DMN), were selected for the Ames test and their mutagenicity was examined using human liver S9 fractions prepared from 18 different donors and one pooled liver S9 fraction prepared from 15 different donors. In addition, rat S9 fraction prepared from male rats pretreated with phenobarbital and 5,6-benzoflavone (PB/BF) was used as reference in order to examine the mutagenic differences between human and rat (PB/BF) S9 fractions.

Peripheral Primitive Neuroectodermal Tumor (Peripheral Neuroepithelioma) in a Dog.

A peripherally located primitive neuroectodermal tumor (peripheral PNET) originating in subcutaneous tissues was observed in an adult Beagle. The highly aggressive tumor spread rapidly and metastasized to various organs. The neoplasm was diagnosed as a peripheral PNET on the basis of morphologic and immunohistochemical characteristics such as small round tumor cells, rosette formations, many interdigitating cytoplasmic processes, neurosecretory granules and microtubules, and positive immunohistochemical reactions to neurogenic markers.