Maiko Kitajima

Maiko Kitajima

*This is an algorithmically generated author record based on publicly available information.

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Maiko Kitajima has a total of 40 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Assessment of air dose distribution in the vertical plane for better occupational exposure management

    by Tomuhiro Noro, Minoru Osanai, Shota Hosokawa, Maiko Kitajima, Megumi Tsushima, Kohsei Kudo

    The International Commission on Radiological Protection recommended a significant reduction of the equivalent dose limit for the eye lens. Reportedly, medical staff in charge of diagnostic imaging procedures may exceed the new dose limits for the eye lens. The use of dosimeters dedicated to the eye lens remains low, and dosimeters for the neck region were often used to assess eye lens doses. However, measurements by neck badges may overestimate or underestimate the recommended eye lens doses because the height of the neck differs from that of the eye. This study aimed to evaluate the air dose distribution in the vertical plane to understand the difference between neck and eye doses. H*(10) in the height of the eye position was 52.8% lower than that in the height of the neck position in the under-table position. Thus, the equivalent eye lens dose evaluated using a neck badge dosimeter may be overestimated.


  • Open Access

    Service-Learning Experiences Related to Health Support Activities for Residents Who Have Returned Home after Evacuation Due to a Radiation Disaster

    by Naoya In, Toshiko Tomisawa, Kasumi Mikami, Mayumi Urushizaka, Kotetsu Tanaka, Chieko Itaki, Maiko Kitajima, Yuka Noto, Ayako Ohgino, Shizuka Takamagi, et al.

    Hirosaki University has regularly offered health support activities to residents of X town in Fukushima, and thus, some interactive benefits are expected as a service-learning experience for nursing students. This study aimed to clarify the experiences of students who participated in service-learning and consider which methods and content were effective. In total, 52 nursing students were recruited into the program, which was held from 2018 to 2021. The roles of students included assisting in health consultations related to a radiation disaster. Questionnaires designed by researchers with experience in risk communication programs were conducted on the students after the program, and included the reasons why they joined, their most memorable experiences, and their opinions regarding required support for residents. The data were analyzed by content analysis. The nursing students thought about the health of residents through health support activities in the affected areas. Furthermore, by communicating with residents via on-site service-learning, they could experience the humanity of the residents and the current status of the affected areas, learn the importance of person-to-person relationships, and think about reconstruction. Thus, service-learning was found to be effective and to offer substantial benefits for both residents and students in affected areas.


  • Open Access

    Psychological and Antibacterial Effects of Footbath Using the Lindera umbellata Essential Oil

    by Maiko Kitajima, Marika Miura, Naoki Nanashima, Toshiko Tomisawa, Shizuka Takamagi, Miyuki Fujioka, Naoya In, Tomohiro Osanai

    Lindera umbellata (Lu) essential oil primarily contains linalool and has relaxation properties. We investigated the psychological and antibacterial effects of footbath with Lu essential oil. The participants included 20 women without medical history and received two intervention plans: footbath without any essential oil and footbath using Lu essential oil. Next, questionnaires regarding impressions and mood states were provided for them to answer. In addition, their autonomic nervous system activity was measured, and the aerobic viable of count on the feet was determined. The high-frequency value reflecting the parasympathetic nervous system activity significantly increased after footbath using Lu essential oil. In the questionnaire about the mood states, the subscale scores of tension–anxiety, depression, fatigue, and confusion after intervention were lower than those before intervention regardless of the use of the essential oil. Conversely, the anger–hostility score decreased only in the group using Lu essential oil. Furthermore, the decrease in aerobic viable count after intervention was not significantly different between the two groups. Footbath using Lu essential oil increased the parasympathetic nervous system activity and relieved anger. Taken together, we suggest that footbath using Lu essential oil has a relaxation effect.


  • Open Access

    Hypocholesterolemic Effect of Blackcurrant (Ribes nigrum) Extract in Healthy Female Subjects: A Pilot Study

    by Naoki Nanashima, Kayo Horie, Maiko Kitajima, Shizuka Takamagi, Kasumi Mikami, Naoya In, Toshiko Tomisawa

    Blackcurrant extract (BCE) ameliorates dyslipidemia in menopausal model animals and in elderly women at a risk of dyslipidemia. However, it is unknown whether the daily intake of BCE can prevent lipid abnormalities in healthy individuals. Lipids are essential for the body, but they also cause arteriosclerosis. In this noncomparative pilot study, we examined the effects of BCE administered for 29 days on serum lipids in young healthy women. Blood samples were collected before and on days 4 and 29 after BCE intake, and 20 lipoprotein fractions in the serum were separated using a gel-permeation high-performance liquid chromatography method to measure the triacylglycerol and cholesterol levels in lipoproteins. There were no effects on lipids on day 4 of BCE intake, but the total cholesterol level decreased on day 29. Furthermore, the levels of total very-low-density lipoprotein (VLDL) cholesterol, small VLDL cholesterol, and large low-density lipoprotein cholesterol were significantly decreased. These results suggest that the daily intake of BCE has a hypocholesterolemic effect in healthy women, and that it is effective in preventing atherosclerosis.


  • Open Access

    Occupational Radiation Dose, Especially for Eye Lens: Hp(3), in Medical Staff Members Involved in Computed Tomography Examinations

    by Minoru Osanai, Hidenori Sato, Kana Sato, Kohsei Kudo, Masahiro Hosoda, Shota Hosokawa, Maiko Kitajima, Megumi Tsushima, Akira Fujita, Yoichiro Hosokawa, et al.

    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.


  • Open Access

    Comparison of Chemical Composition between Kuromoji (Lindera umbellata) Essential Oil and Hydrosol and Determination of the Deodorizing Effect

    by Naoki Nanashima, Maiko Kitajima, Shizuka Takamagi, Miyuki Fujioka, 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.


  • Open Access

    Blackcurrant (Ribes nigrum) Extract Prevents Dyslipidemia and Hepatic Steatosis in Ovariectomized Rats

    by Naoki Nanashima, Kayo Horie, Kanako Yamanouchi, Toshiko Tomisawa, Maiko Kitajima, Indrawati Oey, 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.


  • Open Access

    Effects of Blackcurrant Anthocyanin on Endothelial Function and Peripheral Temperature in Young Smokers

    by Toshiko Tomisawa, Naoki Nanashima, Maiko Kitajima, Kasumi Mikami, Shizuka Takamagi, Hayato Maeda, Kayo Horie, Fu-Chih Lai, 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.


  • Open Access

    Quantitative assessment of radiodermatitis through a non‑invasive objective procedure in patients with breast cancer

    by Maiko Kitajima, Kasumi Mikami, Yuka Noto, Chieko Itaki, Yasuyo Fukushi, Yoshiko Hirota, Yasushi Mariya, Megumi Tsushima, Keiichi Kattou, 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.


  • Open Access

    Blackcurrant Anthocyanins Increase the Levels of Collagen, Elastin, and Hyaluronic Acid in Human Skin Fibroblasts and Ovariectomized Rats

    by Naoki Nanashima, Kayo Horie, Hayato Maeda, Toshiko Tomisawa, Maiko Kitajima, 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.