Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

In hepatocarcinogenesis induced by diethylnitrosamine (DEN) in B6C3F1 mice, the BrafV637E mutation, corresponding to the human BRAFV600E mutation, plays a pivotal role. The livers of transgenic mice with a hepatocyte‐specific human BRAFV600E mutation weighed 4.5 times more than that of normal mice and consisted entirely of hepatocytes, resembling DEN‐induced preneoplastic hepatocytes. However, these transgenic mice spontaneously died 7 wk after birth, therefore this study aimed to clarify the causes of death. In the transgenic mice, the liver showed thrombopoietin (TPO) overexpression, which is associated with eventual megakaryocytosis and thrombocytosis, and activated platelets were deposited in hepatic sinusoids. TPO was also overexpressed in the DEN‐induced hepatic tumors, and sinusoidal platelet deposition was observed in the hepatic tumors of humans and mice. Podoplanin was expressed in some of the Kupffer cells in the liver of the transgenic mice, indicating that platelet activation occurred via the interaction of podoplanin with C‐type lectin receptor 2 (CLEC‐2) on the platelet membrane. Additionally, erythrocyte dyscrasia and glomerulonephropathy/interstitial pneumonia associated with platelet deposition were observed. In the transgenic mice, aspirin (Asp) administration prevented platelet activation, reduced the liver/body weight ratio, decreased the platelet deposition in the liver, kidney, and lung, and prevented erythrocyte dyscrasia and ameliorated the renal/pulmonary changes. Thrombopoietin overproduction by BRAFV600E‐mutated hepatocytes may contribute to hepatocyte proliferation via thrombocytosis, platelet activation, and the interaction of platelets with hepatic sinusoidal cells, while hematologic, renal, and pulmonary disorders due to aberrant platelet activation may lead to spontaneous death in the transgenic mice.

DOI： 10.1111/cas.14130

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/cas.14130

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s10620-019-05729-w

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Other Link： http://link.springer.com/article/10.1007/s10620-019-05729-w/fulltext.html

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.fsigen.2019.03.018

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

We analyzed the degradation level of DNA from buccal cells under humid conditions using quantitative PCR analysis. Gauze samples with buccal cells were incubated for up to 12 months under three different conditions (25 °C/dry, 25 °C/humid, or 40 °C/humid). The degradation was evaluated based on two degradation ratios (129:41 and 305:41 bp). DNA degraded slowly under the 25 °C/humid condition, and significant differences in the two degradation ratios were detected between 25 °C/dry and 25 °C/humid conditions after 12 months. Moreover, the degradation rapidly progressed under the 40 °C/humid condition, and the two degradation ratios in this condition were much lower than those from 25 °C/dry and 25 °C/humid conditions after a short incubation period (3 months). To evaluate the effect of DNA repair on low-copy degraded DNA, degenerate oligonucleotide-primed PCR (DOP-PCR) was performed before short tandem repeats (STR) genotyping. As a standard DOP-PCR, we used a 22-base primer with 10 degenerate sequences (5'-CTCGAGNNNNNNNNNNATGTGG-3'), and additionally designed DOP-PCR primers with 2, 4, 6, or 8 locked nucleic acids (LNAs). When slightly degraded DNA (305:41-bp ratio = 0.60) was used, DOP-PCR significantly increased the fluorescent intensity and success rate of genotyping using Identifiler and Globalfiler kits. In particular, the reaction with four LNAs produced the highest value. However, such benefits were not observed in the analysis of moderately degraded DNA (305:41-bp ratio = 0.13). Although the recovery rates of STR profiles by DOP-PCR were dependent on the degradation level of low-copy DNA, the effectiveness of DOP-PCR highlights the potential of LNA for degenerate sequences.

DOI： 10.1016/j.legalmed.2018.09.005

PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Paraquat (PQ) is a widely used herbicide in the world despite being highly toxic to humans. PQ causes fatal damage to multiple organs, especially the lungs. While oxidative stress is the main toxic mechanism of PQ, there is no established standard therapy for PQ poisoning. In this study, we investigated the cytoprotective effect of 4-phenylbutyrate (4PBA) on PQ toxicity in human lung adenocarcinoma A549 cells. Phosphorylation levels of major survival signaling kinases Akt and ERK, as well as expression levels of antioxidant enzymes catalase and superoxide dismutase 2 (SOD2) were examined. The cytoprotective mechanism of 4PBA against PQ was compared with the antioxidant reagent trolox. We demonstrated that both 4PBA and trolox attenuated PQ toxicity, but their mechanisms were different. 4PBA increased ERK2 phosphorylation levels, which could be inhibited by the PI3K inhibitor LY294002. The cytoprotective effect of 4PBA was also inhibited by LY294002. Catalase expression levels were increased by 4PBA, although this increase was not inhibited by LY294002. 4PBA did not increase SOD2 expression. Trolox did not affect phosphorylation of Akt or ERK, or the expression of antioxidant enzymes. These results suggest that 4PBA attenuated PQ cytotoxicity by ERK2 activation via PI3K. Our study may provide new findings for understanding the molecular mechanism underlying cytoprotection by 4PBA, as well as new therapeutic targets for PQ poisoning.

DOI： 10.1016/j.bbrc.2018.06.080

PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Electrical injury is damage caused by an electrical current passing through the body. We have previously reported that irregular stripes crossing skeletal muscle fibers (python pattern) and multiple small nuclei arranged in the longitudinal direction of the muscle fibers (chained nuclear change) are uniquely observed by histopathological analysis in the skeletal muscle tissues of patients with electrical injury. However, it remains unclear whether these phenomena are caused by the electrical current itself or by the joule heat generated by the electric current passing through the body. To clarify the causes underlying these changes, we applied electric and heat injury to the exteriorized rat soleus muscle in situ. Although both the python pattern and chained nuclear change were induced by electric injury, only the python pattern was induced by heat injury. Furthermore, a chained nuclear change was induced in the soleus muscle cells by electric current flow in physiological saline at 40 °C ex vivo, but a python pattern was not observed. When the skeletal muscle was exposed to electrical injury in cardiac-arrested rats, a python pattern was induced within 5 h after cardiac arrest, but no chained nuclear change was observed. Therefore, a chained nuclear change is induced by an electrical current alone in tissues in vital condition, whereas a python pattern is caused by joule heat, which may occur shortly after death. The degree and distribution of these skeletal muscle changes may be useful histological markers for analyzing cases of electrical injury in forensic medicine.

DOI： 10.1016/j.legalmed.2017.11.001

PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Being a stable metabolite of hydrogen sulfide, thiosulfate has been utilized as an index for hydrogen sulfide poisoning (HSP). Thiosulfate analysis is mainly performed using gas chromatography/mass spectrometry (GC-MS) due to its high sensitivity and specificity. The GC-MS analysis requires two-step derivatizations of thiosulfate, and the derivative is not stable in solution as it has a disulfide moiety. To resolve this stability issue, we developed a novel analytical method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for monitoring the pentafluorobenzyl derivative of thiosulfate (the first reaction product of the GC-MS method) in this study. The established method exhibited high reproducibility despite being a more simplified and rapid procedure compare to the GC-MS method. Phenyl 4-hydroxybenzoate was used as an internal standard because 1,3,5-tribromobenzene which had been used in the GC-MS method was not suitable compound for LC-MS/MS with Electrospray ionization (ESI) negative detection. The linear regression of the peak area ratios versus concentrations was fitted over the concentration ranges of 0.5-250μM and 0.25-250μM in blood and urine, respectively. The validation results satisfied the acceptance criteria for intra- and inter-day accuracy and precision. Blood and urine samples from 12 suspected HSP cases were tested using this method. The thiosulfate concentration detected in the sample coincided well with that determined at the scene of each HSP accident.

DOI： 10.1016/j.legalmed.2016.12.004

PubMed

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Language：Japanese   Publisher：(株)へるす出版  

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Language：Japanese   Publisher：(一社)日本DNA多型学会  

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Language：Japanese   Publisher：(NPO)日本法医学会  

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Language：English   Publisher：(NPO)日本法医学会  

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Language：Japanese   Publisher：(NPO)日本法医学会  

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Language：Japanese   Publisher：(公社)日本薬学会  

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Language：Japanese   Publisher：(NPO)日本法医学会  

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Language：Japanese   Publisher：法医学談話会  

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Language：Japanese   Publisher：(一社)日本DNA多型学会  

急性コルヒチン中毒死事例の胃内容物からギョウジャニンニクおよびイヌサフランの識別を試みた。さらに、酸性条件下(pH2から6)におけるDNAの分解の程度について定量的PCRを用いて検討した。急性コルヒチン中毒事例の胃内容物のうち、葉茎様のもの8片を試料とし、DNeasy Plant Mini Kitを使用してDNAを抽出した。属特異的配列に基づいて設計したFAMおよびVICで標識したプライマーの特異性を確認し、ネギ属から99bpの青色のピーク、コルチカム属から緑色の81bpのピークが検出された。DNAバーコーディング解析ではギョウジャニンニクおよびイヌサフランは確認できなかった。一方、属特異的な増幅では、ネギ属が2試料、コルチカム属が4試料から検出された。摂取したコルヒチン含有植物はイヌサフランである可能性が高いと考えられた。酸性処理した植物片からのコピー数の決定および分解度の測定を行った結果、96bpに基づいたコピー数は各pHで時間の経過とともに減少しており、特にpH2からpH5の120分では顕著に減少していた。それに対し、分解度を示す342bp/96bpはpH2で大きく減少していたが、pH3からpH6でわずかな減少、あるいは減少は認められなかった。以上より、必ずしも大きなpHでなくてもDNA量は大きく減少し、DNA分析が困難になると考えられた。

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Language：Japanese   Publisher：(株)へるす出版  

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Language：Japanese   Publisher：日本組織細胞化学会  

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Language：Japanese   Publisher：(株)へるす出版  

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Language：Japanese   Publisher：(NPO)日本法医学会  

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Language：Japanese   Publisher：(NPO)日本法医学会  

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Language：Japanese   Publisher：法医学談話会  

分析試料の総数は1538検体で、DNA鑑定は戦没者遺骨の判別が778検体で最も多く、次いで解剖死体468検体、現場遺留試料292検体の順であった。遺骨試料445検体のうち大半が歯牙であり、多くの場合1本から良好な常染色体STR型、Y染色体SR型およびmtDNA多型の結果が得られた。比較対照である遺族試料は333検体解析し、身元が特定されたのは113検体であった。解剖死体では238事例280検体から型判定を行い、試料は血液が43%で最も多かった。多くの場合、15座位のSTR判定により、対照試料を用いることで身元が判定された。分析した遺留試料は156検体で、毛髪を含む人毛が71検体と最も多く、次いで多いものがガーゼ片であった。人毛では2検体からのみSTR型が検出可能であったが、mtDNA多型は55検体から検出可能であった。対照試料は136検体で、大半が口腔内細胞であった。

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Language：Japanese   Presentation type：Poster presentation  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Type：Peer review 

2023年4月 査読1件
2025年3月 査読1件
2025年4月 査読1件

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Type：Academic society, research group, etc. 

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Type：Academic society, research group, etc. 

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Type：Academic society, research group, etc. 

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Type：Peer review 

2022年4月～2023年3月 査読19件
2023年4月～2024年3月 査読16件
2024年4月～2025年3月 査読14件

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