Maiko Kitajima

Dr. Maiko Kitajima

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 April 2018 in Nutrients
Verified
Journal Article
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NNNaoki Nanashima
Naoki Nanashima
KHKayo Horie
Kayo Horie
Hayato MaedaHayato Maeda
Hayato Maeda
TTToshiko Tomisawa
Toshiko Tomisawa
MKMaiko Kitajima
Maiko Kitajima
TNToshiya Nakamura
Toshiya Nakamura
Blackcurrants (Ribes nigrum L.) contain high levels of anthocyanin polyphenols, which have beneficial effects on health, owing to their antioxidant and anticarcinogenic properties. Phytoestrogens are plant-derived substances with estrogenic activity, which could have beneficial effects on the skin. Estradiol secretion decreases during menopause, reducing extracellular matrix (ECM) component production by skin fibroblasts. Using a normal human female skin fibroblast cell line (TIG113) and ovariectomized rats, the present study investigated whether an anthocyanin-rich blackcurrant extract (BCE) and four blackcurrant anthocyanins have novel phytoestrogenic activities that could benefit the skin in menopausal women. In TIG113 cells, a microarray and the Ingenuity® Pathway Analysis showed that 1.0 μg/mL of BCE upregulated the expression of many estrogen signaling-related genes. A quantitative RT-PCR analysis confirmed that BCE (1.0 or 10.0 μg/mL) and four types of anthocyanins (10 μM) altered the mRNA expression of ECM proteins and enzymes involved in ECM turnover. Immunofluorescence staining indicated that the anthocyanins stimulated the expression of ECM proteins, such as collagen (types I and III) and elastin. Dietary administration of 3% BCE to ovariectomized rats for 3 months increased skin levels of collagen, elastin, and hyaluronic acid. This is the first study to show that blackcurrant phytoestrogens have beneficial effects on skin experimental models.

25 May 2020 in Nutrients
Verified
Journal Article
Open access
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NNNaoki Nanashima
Naoki Nanashima
KHKayo Horie
Kayo Horie
KYKanako Yamanouchi
Kanako Yamanouchi
TTToshiko Tomisawa
Toshiko Tomisawa
MKMaiko Kitajima
Maiko Kitajima
Hayato MaedaHayato Maeda
Hayato Maeda
Estrogen is involved in lipid metabolism. Menopausal women with low estrogen secretion usually gain weight and develop steatosis associated with abnormal lipid metabolism. A previous study showed that blackcurrant (Ribes nigrum L.) extract (BCE) had phytoestrogen activity. In this study, we examined whether BCE improved lipid metabolism abnormalities and reduced liver steatosis in ovariectomized rats, as a menopausal animal model. Twelve-week-old ovariectomized (OVX) rats were fed a regular diet (Ctrl) or a 3% BCE supplemented diet while sham rats were fed a regular diet for three months. Body weight, visceral fat weight, levels of serum triglycerides, total cholesterol, and LDL cholesterol decreased in the BCE-treated OVX and sham rats, but not in OVX Ctrl rats. The results of hematoxylin and eosin staining revealed that BCE decreased the diameters of adipocytes and the nonalcoholic fatty liver disease activity score. Furthermore, quantitative RT-PCR indicated a decreased expression of hepatitis-related genes, such as tumor necrosis factor-α, IL-6, and IL-1β in OVX rats after BCE treatment. This is the first study that reported improvement of lipid metabolism abnormalities in OVX rats by BCE administration. These results suggest that the intake of BCE alleviated dyslipidemia and prevented nonalcoholic steatohepatitis during menopause in this animal model.

25 November 2019 in Molecules
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Journal Article
Open access
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TTToshiko Tomisawa
Toshiko Tomisawa
NNNaoki Nanashima
Naoki Nanashima
MKMaiko Kitajima
Maiko Kitajima
KMKasumi Mikami
Kasumi Mikami
STShizuka Takamagi
Shizuka Takamagi
TOTomohiro Osanai
Tomohiro Osanai
Background: Blackcurrant anthocyanin (BCA) is expected to repair endothelial dysfunction, but it remains unclear whether beneficial effects are present in young healthy persons. This study examines whether supplements containing blackcurrant anthocyanin improve endothelial function and peripheral temperature in young smokers. Methods: Young, healthy male nonsmokers (N group: n = 11; mean age 22 ± 2 years) and smokers (S group: n = 13; mean age 21 ± 1 years) were enrolled. A randomized and double-blind trial was designed to compare the effects of no supplement, a supplement containing 50 mg of blackcurrant anthocyanin (supplement A), and a supplement containing 50 mg of blackcurrant anthocyanin plus vitamin E (supplement B) on flow-mediated dilatation (FMD) and skin temperature. Results: Under no supplement, FMD was unchanged during the 2 h period after smoking in the N group, whereas it was decreased during the 2 h period after smoking in the S group. Under the A supplement, FMD was decreased 1 h after smoking and returned to the baseline level 2 h after smoking in the S group. The skin temperature in the area of the foot dorsum was decreased in the S group after smoking compared with that in the N group, who did not smoke, whereas under A and B supplements, it was higher in the S group compared with that in the N group. Conclusions: BCA could attenuate the smoking-induced acute endothelial dysfunction and improve peripheral temperature in young smokers.

13 September 2020 in Molecules
Verified
Journal Article
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NNNaoki Nanashima
Naoki Nanashima
MKMaiko Kitajima
Maiko Kitajima
STShizuka Takamagi
Shizuka Takamagi
MFMiyuki Fujioka
Miyuki Fujioka
TTToshiko Tomisawa
Toshiko Tomisawa
Kuromoji (Lindera umbellata) is a tree that grows throughout Japan. The components of kuromoji essential oil have antitumor and aromatherapy effects. However, the composition of the hydrosol, obtained as a by-product of the essential oil process, is unknown. Furthermore, it is unknown whether kuromoji essential oil has a deodorizing effect. Therefore, the purpose of the current study was to compare the chemical composition of kuromoji essential oil and hydrosol, as well as evaluate the deodorizing effect of the former. The chemical composition of samples was evaluated using gas chromatography–mass spectrometry (GC-MS). Additionally, the deodorizing effect of Kuromoji essential oil was investigated with the detector tube method using ammonia, hydrogen sulfide, methyl mercaptan, and isovaleric acid. Linalool was the most abundant component in both the essential oil and hydrosol; however, its proportion was higher in the hydrosol (57.5%) than in the essential oil (42.8%). The hydrosol contained fewer chemical components, but higher proportions of trans-geraniol and ethanol. Moreover, the essential oil eliminated 50% of ammonia and 97.6% or more of isovaleric acid. Interestingly, linalool was soluble in the hydrosol and did not irritate the skin. This suggests that the hydrosol may be an effective foot care product.

11 November 2019 in Molecular and Clinical Oncology
Verified
Journal Article
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MKMaiko Kitajima
Maiko Kitajima
KMKasumi Mikami
Kasumi Mikami
YNYuka Noto
Yuka Noto
CIChieko Itaki
Chieko Itaki
YFYasuyo Fukushi
Yasuyo Fukushi
TOTomohiro Osanai
Tomohiro Osanai
Assessment of skin condition is necessary for providing advice regarding skin self‑care to patients with breast cancer who have undergone radiation therapy. Acute and chronic phases of radiodermatitis were analyzed in patients using objective assessment tools in the present study. A total of 18 women who received radiation therapy for breast cancer were enrolled in the present study and their skin surface temperature (SST), hydration level of the skin surface (HL), melanin intensity (MI) and erythema intensity (EI) were measured prior to radiation therapy and six months thereafter. Furthermore, skin condition was assessed using the Common Terminology Criteria for Adverse Events (CTCAE). EI and MI levels at the irradiated site peaked upon the completion of radiation therapy and declined to baseline at 6 months. In contrast, SST levels were elevated at the irradiated site during radiation therapy (P<0.05) and plateaued after its completion. The same parameters in non‑irradiated control sites remained unchanged during the study period. HL reached the minimum in irradiated and non‑irradiated sites upon completion of radiation therapy. Although HL returned to baseline in the non‑irradiated site 6 months after radiation therapy, it remained low in the irradiated site. No relationship between the CTCAE and EI level was observed. In conclusion, the present study demonstrated that objective assessment tools, including SST and EI levels, were useful for assessing skin condition during radiodermatitis. The combination of the CTCAE and objective assessment tools will enable a more accurate assessment of radiodermatitis.

13 May 2021 in Applied Sciences
Verified
Journal Article
Open access
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MOMinoru Osanai
Minoru Osanai
HSHidenori Sato
Hidenori Sato
KSKana Sato
Kana Sato
KKKohsei Kudo
Kohsei Kudo
Masahiro HosodaMasahiro Hosoda
Masahiro Hosoda
Yoko SaitoYoko Saito
Yoko Saito
Radiation dose management of medical staff has become increasingly important. Particularly, based on the statement by the International Commission on Radiological Protection (ICRP) in 2011, a new lower equivalent dose limit for the eye lens is being established in each country. Although many reports have discussed the occupational radiation dose in interventional radiology (IR), few studies have examined the dose during computed tomography (CT) examinations. This study investigated the radiation dose exposure to medical staff present in the CT room during irradiation, with particular focus on the exposure to eye lens. The radiation dose exposure to those who assist patients during head, chest and upper abdomen CT examination was measured in a phantom study. The radiation dose exposure with scattered radiation was never negligible (i.e., high); Hp(3) was the highest in head CT examination, at 0.44 mSv per examination. Furthermore, the shielding effect of radiation protection glasses was large, and radiation protection glasses are useful tools for the medical staff who are involved in CT examinations. The justification and optimisation should be carefully considered in assistant actions.