著者

Shun Sato Tokuma Fukuoka Azusa Saika Tatsuyuki Koshiyama Tomotake Morita

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.68, no.12, pp.1287-1294, 2019 (Released:2019-12-01)

参考文献数

16

被引用文献数

12

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We applied matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) to screen for glycolipid-type biosurfactant (BS) producers. A crude extract of Pseudozyma antarctica, a well-known mannosylerythritol lipid (MEL) producer, was initially subjected to MALDI-TOF/MS. The spectrum of the extract showed the accumulation of diacylated MELs in culture. We then screened 80 environmental samples for BS-producing yeasts, and extracts from broth cultures of the selected five strains were examined using MALDI-TOF/MS. The results showed that all five strains produced MELs, whereas four strains also produced cellobiose lipids (CLs). By D1/D2 region sequence analysis, the MEL-producing strain was assigned to P. antarctica while the four MEL- and CL-producing strains were assigned to P. hubeiensis. These results demonstrate that MALDI-TOF/MS is a rapid and reliable tool to detect BS molecules in crude extracts of broth cultures to screen for glycolipid-type BS producers.

著者

Shun Sato Chengzhu Yin Akira Teramoto Yasuo Sakuma Masakatsu Kato

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

The Journal of Physiological Sciences (ISSN:18806546)

巻号頁・発行日

vol.58, no.5, pp.317-322, 2008 (Released:2008-10-29)

参考文献数

47

被引用文献数

7 16

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Gonadotropin-releasing hormone (GnRH) neurons represent the final output neurons in the central control of reproduction. γ-Amino butyric acid (GABA), one of the major regulators of GnRH neurons, depolarizes GnRH neurons isolated from adult rats via GABAA receptors. The presence of GABAA receptors in GnRH neurons has also been demonstrated morphologically. Furthermore, the pineal hormone melatonin is involved in the regulation of reproductive function, including the timing of the luteinizing hormone surge. The suprachiasmatic nucleus and the GABAergic system in the medial preoptic area are considered as possible sites of the action of melatonin. Until now, however, a direct action of melatonin on GnRH neurons has not been reported. Therefore we examined the effect of melatonin on GABAA receptor currents in GnRH neurons isolated from GnRH-EGFP transgenic rats by means of perforated patch-clamp experiments. The GABAA receptor currents were modulated by melatonin in a sex-specific manner. In GnRH neurons from adult males, melatonin augmented these currents in 67% of the neurons examined, but attenuated the currents in only 19% of them. These modulations were blocked by the melatonin receptor antagonist luzindole, suggesting an involvement of melatonin receptors. The modulation by melatonin was not observed in GnRH neurons isolated from infantile rats. These findings indicate that GABA affects the excitability of GnRH neurons in adult rats through GABAA receptors, and that melatonin modifies this excitability via melatonin receptors in a sex-specific manner.

著者

Yosuke Kakisaka Tomoichiro Ohara Hideo Tozawa Shun Sato Saori Katayama Tasuku Suzuki Naomi Hino-Fukuyo Shigeo Kure

出版者

東北ジャーナル刊行会

雑誌

The Tohoku Journal of Experimental Medicine (ISSN:00408727)

巻号頁・発行日

vol.228, no.2, pp.143-145, 2012 (Released:2012-09-22)

参考文献数

7

被引用文献数

2 9

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Gynecomastia or benign proliferation of the male breast glandular tissue is not uncommon for adolescent males. Its pathogenesis has been attributed to a transient imbalance between estrogens and androgens. Ginseng is a popular herb with a long history of medicinal use. Oriental folk medicine describes it as both a tonic for restoring strength and a panacea. The term “ginseng” generally refers to a plant, Panax ginseng. Based on estrogen-like actions of Panax ginseng due to its structural similarity with estradiol, this agent could be speculated to cause gynecomastia. Here we report a 12-year-old Korean-Japanese boy with bilateral enlargement of the breasts with tenderness in the right breast, which was noticed about 1 month before his first visit to our outpatient clinic. He was diagnosed with gynecomastia based on physical, laboratory, and ultrasound examinations. Detailed questioning about his medications and supplements revealed that he had been given red ginseng extract daily to enhance his performance for 1 month before his clinical presentation. He wanted to make his body stronger as an athlete. He was recommended from his grandmother to take Panax ginseng for his purpose. After stopping this, there was no further growth of the masses and no pain when his right breast was pressed. In conclusion, physicians should consider ginseng in the investigation of gynecomastia.