Yoshiharu Tanaka

Dr. Yoshiharu Tanaka

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Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

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

Representative Publications

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1 July 2022 in Medical Gas Research
Verified
Journal Article
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YTYoshiharu Tanaka
Yoshiharu Tanaka
LXLi Xiao
Li Xiao
NMNobuhiko Miwa
Nobuhiko Miwa
This study compared the effects of hydrogen-water (HW) bath on the oxygen radical absorption-based antioxidant capacity and the inflammatory indicator, C-reactive protein (CRP), in serum between healthy volunteers and inflammatory/collagen disease-patients. The HW bath apparatus supplied nano-bubbles with a diameter of 110 ± 10 nm and 338–682 μg/L of dissolved hydrogen after 120 minutes electrolysis, and nano-bubbles increased to 9.91 × 107/mL along with the increase of correlative dissolved hydrogen. Ten-minute HW bath increased the oxygen radical absorption-based antioxidant capacity to 110.9 ± 9.2% at post-bathing 120 minutes, although unaltered with 10-minute normal water bath at 40°C in healthy subjects. The CRP level was repressed to 70.2 ± 12.1% at 120 minutes after HW bath, although rather increased for normal water bath. In the patients with connective tissue diseases, the CRP level was repressed to 3–24% upon 9 days to 4 months of HW bathing. In another six patients with diverse autoimmune-related diseases, upon daily HW bathing as long as 2–25 months, the pre-bathing CRP level of 5.31 mg/dL decreased to 0.24 mg/dL being within the standard-range, with relief of visible inflammatory symptoms for some cases. Thus, the HW bath with high-density nano-bubbles has beneficial effects on serum antioxidant capacity, inflammation, and the skin appearance. The study was approved by the Committee of Ethics, Japanese Center of Anti-Aging Medical Sciences (Authorization No. H-15-03-2, on January 15, 2019), which was a non-profitable organization officially authenticated by the Hiroshima Prefecture Government of Japan.

1 October 2003 in Anesthesiology
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Journal Article
Open access
SGSumiko Gamo
Sumiko Gamo
JTJunya Tomida
Junya Tomida
KDKatsuyuki Dodo
Katsuyuki Dodo
DKDai Keyakidani
Dai Keyakidani
HMHitoshi Matakatsu
Hitoshi Matakatsu
YTYoshiharu Tanaka
Yoshiharu Tanaka
Background: Various species, e.g., Caenorhabditis elegans, Drosophila melanogaster, and mice, have been used to explore the mechanisms of action of general anesthetics in vivo. The authors isolated a Drosophila mutant, ethas311, that was hypersensitive to diethylether and characterized the calreticulin (crc) gene as a candidate of altered anesthetic sensitivity. Methods: Molecular analysis of crc included cloning and sequencing of the cDNA, Northern blotting, and in situ hybridization to accomplish the function of the gene and its mutation. For anesthetic phenotype assay, the 50% anesthetizing concentrations were determined for ethas311, revertants, and double-mutant strains (wild-type crc transgene plus ethas311). Results: Expression of the crc 1.4-kb transcript was lower in the mutant ethas311 than in the wild type at all developmental stages. The highest expression at 19 h after pupation was observed in the brain of the wild type but was still low in the mutant at that stage. The mutant showed resistance to isoflurane as well as hypersensitivity to diethylether, whereas it showed the wild phenotype to halothane. Both mutant phenotypes were restored to the wild type in the revertants and double-mutant strains. Conclusion: ethas311 is a mutation of low expression of the Drosophila calreticulin gene. The authors demonstrated that hypersensitivity to diethylether and resistance to isoflurane are associated with low expression of the gene. In Drosophila, calreticulin seems to mediate these anesthetic sensitivities, and it is a possible target for diethylether and isoflurane, although the predicted anesthetic targets based on many studies in vitro and in vivo are the membrane proteins, such as ion channels and receptors.

1 January 2017 in Medical Gas Research
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YTYoshiharu Tanaka
Yoshiharu Tanaka
QLQiang Li
Qiang Li
NMNobuhiko Miwa
Nobuhiko Miwa
In the last decade, many studies have shown that hydrogen gas or hydrogen water can reduce the levels of reactive oxygen species in the living body. Molecular hydrogen has antioxidant and antiapoptotic effects and a preventive effect on oxidative stress-induced cell death. In the present study, we investigated solidified hydrogen-occluding-silica (H2-silica) that can release molecular hydrogen into cell culture medium because the use of hydrogen gas has strict handling limitations in hospital and medical facilities and laboratories, owing to its physicochemical characteristics. Human esophageal squamous cell carcinoma (KYSE-70) cells and normal human esophageal epithelial cells (HEEpiCs) were used to investigate the effects of H2-silica on cell viability and proliferation. Cell migration was examined with wound healing and culture-insert migration assays. The intracellular levels of reactive oxygen species were evaluated with a nitroblue tetrazolium assay. To assess the apoptotic status of the cells, the Bax/Bcl-2 ratio and cleaved caspase-3 were analyzed by western blot. The results showed that KYSE-70 cells and HEEpiCs were generally inhibited by H2-silica administration, and there was a significant proliferation-inhibitory effect in an H2-silica concentration-dependent manner compared with the control group (P < 0.05) in KYSE-70. Apoptosis-inducing effect on KYSE-70 cells was observed in 10, 300, 600, and 1,200 ppm H2-silica, and only 1,200 ppm H2-silica caused a 2.4-fold increase in apoptosis in HEEpiCs compared with the control group as the index of Bax/Bcl-2. H2 silica inhibited cell migration in KYSE-70 cells, and high concentrations had a cytotoxic effect on normal cells. These findings should provide insights into the mechanism of inhibition of H2-silica on human cancer cells in vitro.

22 April 2022 in Archives of Microbiology
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RARyoko Asada
Ryoko Asada
TWTakeru Watanabe
Takeru Watanabe
YTYoshiharu Tanaka
Yoshiharu Tanaka
MKMasao Kishida
Masao Kishida
MFMasakazu Furuta
Masakazu Furuta

1 June 2007 in Current Medicinal Chemistry
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YTYoshiharu Tanaka
Yoshiharu Tanaka
MTMasaya Takase
Masaya Takase
SGSumiko Gamo
Sumiko Gamo
On undergoing an operation under general anesthesia, we tend to lose consciousness, and on recovering from the anesthetic effect, we realize a memory loss during the operation, but do remember the happenings before the operation. It implies that the anesthesia deprivers us of short-term memory without affecting long-term memory. Drosophila melanogaster is known to be an excellent model for genetic studies related to general anesthesia and memory. The various mutants in the genes related to general anesthesia and memory have been found to influence these mechanisms at the molecular level. In Drosophila, learning and memory are classified into four distinct phases: (1) short-term memory (STM), (2) middle-term memory (MTM), (3) longer-lasting anesthesia-resistant memory (ARM), and (4) long-term memory (LTM). On the other hand, based on the genetic studies of the putative target molecules of general anesthetics in model animals, the anesthetic action is classified into five pathways: (1) presynaptic pathway including action potential production, its transmission, and neurotransmitter release; (2) postsynaptic pathway including inhibitory receptors for sleep and pain; (3) memory pathway coupled with cAMP/PKA signaling; (4) adhesion pathway in neuron; and (5) energy production pathway. Memory and adhesion pathways of the anesthetic action are developed in the Drosophila melanogaster model. Many mutants of general anesthesia and those of memory are overlapped suggesting that common molecules and signal pathways are involved in both phenomena. In this review, we will describe the relation between anesthesia and memory, especially highlighting the interaction between the general anesthetics and STM and MTM processes in Drosophila, especially concentrating on the cAMP/PKA signaling and molecular adhesion pathways.

9 December 2020 in Journal of Radiation Research
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Journal Article
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YTYoshiharu Tanaka
Yoshiharu Tanaka
MFMasakazu Furuta
Masakazu Furuta
While the damage to chromosomes and genes induced by high-dose radiation (HDR) has been well researched in many organisms, the effects of low-dose radiation (LDR), defined as a radiation dose of ≤100 mSv, are still being debated. Recent research has suggested that the biological effects of LDR differ from those observed in HDR. To detect the effect of LDR on genes, we selected a gene of Drosophila melanogaster, known as the multiple wing hair (mwh) gene. The hatched heterozygous larvae with genotype mwh/+ were irradiated by γ-rays of a 60Co source. After eclosion, the wing hairs of the heterozygous flies were observed. The area of only one or two mwh cells (small spot) and that of more than three mwh cells (large spot) were counted. The ratio of the two kinds of spots were compared between groups irradiated by different doses including a non-irradiated control group. For the small spot in females, the eruption frequency increased in the groups irradiated with 20–75 mGy, indicating hypersensitivity (HRS) to LDR, while in the groups irradiated with 200 and 300 mGy, the frequency decreased, indicating induced radioresistance (IRR), while in males, 50 and 100 mGy conferred HRS and 75 and 200 mGy conferred IRR. For the large spot in females, 75 mGy conferred HRS and 100–800 mGy conferred IRR. In conclusion, HRS and IRR to LDR was found in Drosophila wing cells by delimiting the dose of γ-rays finely, except in the male large spot.