Publications by authors named "Sayaka Kawaguchi"

According to the ICH S3A Q&A, microsampling is applicable to pharmaceutical drugs and toxicological analysis. Few studies have reported the effect of microsampling on the toxicity of immunotoxicological drugs. The aim of this multicenter study was to evaluate the toxicological effects of serial microsampling on rats treated with azathioprine as a model drug with immunotoxic effects.

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The site-directed chemical conjugation of antibodies remains an area of great interest and active efforts within the antibody-drug conjugate (ADC) community. We previously reported a unique site modification using a class of immunoglobulin-G (IgG) Fc-affinity reagents to establish a versatile, streamlined, and site-selective conjugation of native antibodies to enhance the therapeutic index of the resultant ADCs. This methodology, termed "AJICAP", successfully modified Lys248 of native antibodies to produce site-specific ADC with a wider therapeutic index than the Food and Drug Administration-approved ADC, Kadcyla.

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Although microsampling of blood is recommended to promote the 3Rs in toxicokinetic (TK) evaluation, there are few reports applying microsampling in actual toxicity evaluation. Here, we assessed the effects of microsampling on toxicological evaluation of methapyrilene hydrochloride, a hepatotoxic substance. Female SD rats received methapyrilene hydrochloride orally at dose levels of 0 (vehicle), 10, and 30 mg/kg BW, once daily for 4 weeks.

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Although astrocytes are involved in the pathogenesis of CNS diseases, how they induce synaptic abnormalities is unclear. Currently, pathological astrocyte cultures or animal models do not reproduce human disease phenotypes accurately. Induced pluripotent stem cells (iPSCs) are replacing animal models in pathological studies.

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To overcome a lack of selectivity during the chemical modification of native non-engineered antibodies, we have developed a technology platform termed "AJICAP" for the site-specific chemical conjugation of antibodies through the use of a class of IgG Fc-affinity reagents. To date, a limited number of antibody-drug conjugates (ADCs) have been synthesized via this approach, and no toxicological study was reported. Herein, we describe the compatibility and robustness of AJICAP technology, which enabled the synthesis of a wide variety of ADCs.

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