- 著者
- Nami Takada Mitsuyoshi Hirokawa Chiho Ohbayashi Takeshi Nishikawa Tomoo Itoh Naoko Imagawa Tetsunari Oyama Tadashi Handa Tadashi Hasegawa Shintaro Sugita Akiko Murata Akira Miyauchi
- 出版者
- The Japan Endocrine Society
- 雑誌
- Endocrine Journal (ISSN:09188959)
- 巻号頁・発行日
- vol.65, no.2, pp.239-244, 2018 (Released:2018-02-26)
- 参考文献数
- 14
- 被引用文献数
- 6 18
Hyalinizing trabecular tumour (HTT) immunohistochemically shows cell membranous immunoreactivity for MIB-1. This aberrant immunoreactivity is an important factor for the diagnosis of HTT. However, fully automated stainers frequently fail to confirm the immunoreactivity. The aim of this study is to investigate the cause of false negative cell membranous immunoreactivity for MIB-1 in HTT using fully automated stainers, to determine potential reasons for the problem, and to establish methods confirming cell membranous immunoreactivity for MIB-1 in HTT. Six participating institutions examined immunoreactivity for MIB-1 in 10 HTT cases using two approaches: fully automated and semi-automated methods. In the latter, antigen retrieval was carried out using manual methods adopted for routine assays at each institute. The autostainers used included the BOND-MAX, BOND-III, Benchmark XT, and Omnis systems. Using fully automated methods, institute E showed cell membranous MIB-1 positivity in all HTT cases. In contrast, at institute D, all HTT cases were negative. The positive rates of the remaining four institutes ranged from 10% to 20%. The incidence of positive cases using semi-automated methods was 100%, 90%, 90%, 30%, 80%, and 100% at institutes A, B, C, D, E, and F, respectively. We assert that antigen retrieval should be conducted manually for diagnosis of HTT; furthermore, definitively diagnosed HTT should be prepared as the external positive control.
- 著者
- Maika KISSEI Tomoo ITOH Tomoya NARAWA
- 出版者
- The Japanese Society for the Study of Xenobiotics
- 雑誌
- Drug Metabolism and Pharmacokinetics (ISSN:13474367)
- 巻号頁・発行日
- vol.29, no.5, pp.367-372, 2014-10-25 (Released:2014-10-25)
- 参考文献数
- 45
- 被引用文献数
- 7
Folic acid (FA) is a water-soluble vitamin, and orally ingested FA is absorbed from the small intestine by the proton-coupled folate transporter (PCFT). In the present study, we investigated whether epigallocatechin gallate (EGCG), one of the tea catechins, affects the transport of FA by PCFT. EGCG inhibited the uptake of FA into Caco-2 cells and human PCFT-expressing HEK293 cells (PCFT-HEK293 cells). The initial rate of uptake of FA into PCFT-HEK293 cells followed Michaelis–Menten kinetics (Km = 1.9 µM). Dixon plots revealed that PCFT-mediated FA uptake was competitively inhibited by EGCG (Ki ≒ 9 µM). The uptake of the PCFT substrate methotrexate (MTX) was competitively inhibited by EGCG as well (Ki ≒ 15 µM). In conclusion, it is suggested that when FA or MTX is ingested with tea, it is likely that the intestinal absorption of these compounds by PCFT is inhibited, which could result in insufficient efficacy.