著者

Shingo Tanaka Noboru Ohba Kiyoshi Abe Yuka Tamoto Kenji Yasui Chihiro Kobayashi Nagomi Saito Koji Miyanishi Satoshi Takahashi Junji Kato

出版者

Japanese Society of Laboratory Medicine

雑誌

Laboratory Medicine International (ISSN:24368660)

巻号頁・発行日

vol.2, no.3, pp.42-49, 2023 (Released:2023-12-29)

参考文献数

24

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Aims: Attenuation imaging (ATI) is a new ultrasonography method of evaluating hepatic steatosis. Attenuation coefficients (ACs) in the region of interest are measured using two-dimensional ultrasonography. ATI also displays the coefficient of determination (R2) as an index of AC reliability. This study aimed to elucidate R2 values in patients who underwent ATI in clinical practice and to determine factors that influence R2 values. Methods: This study included 749 patients who underwent ATI to evaluate hepatic steatosis at a single center. All abdominal ultrasound examinations were performed by one of the five experienced ultrasonographers. The AC and R2 values were measured five times, and the median values were calculated. Multivariate analysis was conducted to identify factors affecting R2 values. Results: One hundred and nine (15%) patients showed R2 values of < 0.80, of which 108 had non-fatty liver. Further, the R2 value was strongly correlated with AC (correlation coefficient = 0.842). Uncomplicated diabetes (Odds ratio [OR], 2.68) and AC (< 0.60 dB/cm/MHz; OR, 72.76) were identified as independent factors associated with low R2 values (< 0.80). Conclusion: ATI in patients with non-fatty liver showed low R2 values. Worldwide standardization of the ATI measurement method is urgently needed for consistent results.

著者

Shabierjiang JIAPAER Takuya FURUTA Shingo TANAKA Tomohiro KITABAYASHI Mitsutoshi NAKADA

出版者

The Japan Neurosurgical Society

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

vol.58, no.10, pp.405-421, 2018 (Released:2018-10-15)

参考文献数

154

被引用文献数

78 210

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Glioblastoma (GBM) is a highly malignant type of primary brain tumor with a high mortality rate. Although the current standard therapy consists of surgery followed by radiation and temozolomide (TMZ), chemotherapy can extend patient’s post-operative survival but most cases eventually demonstrate resistance to TMZ. O6-methylguanine-DNA methyltransferase (MGMT) repairs the main cytotoxic lesion, as O6-methylguanine, generated by TMZ, can be the main mechanism of the drug resistance. In addition, mismatch repair and BER also contribute to TMZ resistance. TMZ treatment can induce self-protective autophagy, a mechanism by which tumor cells resist TMZ treatment. Emerging evidence also demonstrated that a small population of cells expressing stem cell markers, also identified as GBM stem cells (GSCs), contributes to drug resistance and tumor recurrence owing to their ability for self-renewal and invasion into neighboring tissue. Some molecules maintain stem cell properties. Other molecules or signaling pathways regulate stemness and influence MGMT activity, making these GCSs attractive therapeutic targets. Treatments targeting these molecules and pathways result in suppression of GSCs stemness and, in highly resistant cases, a decrease in MGMT activity. Recently, some novel therapeutic strategies, targeted molecules, immunotherapies, and microRNAs have provided new potential treatments for highly resistant GBM cases. In this review, we summarize the current knowledge of different resistance mechanisms, novel strategies for enhancing the effect of TMZ, and emerging therapeutic approaches to eliminate GSCs, all with the aim to produce a successful GBM treatment and discuss future directions for basic and clinical research to achieve this end.