Publications by authors named "Hiroki Asakawa"

11 Publications

  • Page 1 of 1

Ischemic hepatitis with infectious endocarditis: A case report.

Biomed Rep 2021 Nov 22;15(5):97. Epub 2021 Sep 22.

Department of Gastroenterology, Suzuka General Hospital, Suzuka, Mie 513-8630, Japan.

A 58-year-old woman was admitted to Suzuka General Hospital with fever. She was diagnosed with infectious endocarditis based on the presence of anterior mitral leaflet vegetation on the echocardiography analysis and isolation of by blood culture. During treatment, the hepatic enzymes levels, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were increased without any abdominal symptoms. Prolonged prothrombin time (PT) and prothrombin time international normalized ratio were observed, and acute hepatic failure was diagnosed. However, the hepatic injury resolved spontaneously with restoration of the PT value after the hepatic enzymes (AST, ALT, LDH and ALP) peaked. Diffusion-weighted imaging of hepatic magnetic resonance imaging showed diffuse high intensity of the entire liver except for part of the left lobe. The hepatic injury was diagnosed as ischemic hepatitis caused by embolization from the vegetation associated with infectious endocarditis. The recovery from hepatic ischemia was thought to be due to hepatic blood supply from extrahepatic collateral blood. After antibiotic treatment, the patient underwent resection of the vegetation on the anterior mitral valve leaflet. Hepatic artery occlusion is rare, but it may cause severe hepatic complications. During follow-up of infectious endocarditis, clinicians should be aware of the potential for whole organ ischemic damage caused by vessel occlusion, as well as hepatic ischemic damage.
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http://dx.doi.org/10.3892/br.2021.1473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8493543PMC
November 2021

Early stage clear cell adenocarcinoma coexisting with tubular adenoma and adenoma with clear cell change in the colon.

Clin J Gastroenterol 2021 Apr 8;14(2):589-593. Epub 2021 Jan 8.

Department of Clinical Laboratory Medicine, Shiga University of Medical Science, 520-2192, Seta Tsukinowa, Otsu, Shiga, Japan.

Primary clear cell adenocarcinoma (CCA) of the colorectum is rare. We report a case of a 57-year-old man with early-stage CCA with conventional tubular adenoma and tubular adenoma with clear cell change in the transverse colon, diagnosed with image-enhanced endoscopy. The tumor was then treated with endoscopic submucosal dissection. The endoscopic findings characteristic of clear cell adenoma/adenocarcinoma could not be identified. Therefore, similar diagnostic tools as for conventional colorectal adenoma/cancer were considered. The pathogenesis of the clear cell change was unknown, but it might appear with the progression of the malignancy.
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http://dx.doi.org/10.1007/s12328-020-01334-xDOI Listing
April 2021

Salvage endoscopic submucosal dissection with a small-caliber endoscope for recurrent esophageal cancer on distal side of esophageal stricture.

Endoscopy 2021 10 19;53(10):E363-E364. Epub 2020 Nov 19.

Department of Gastroenterology and Hepatology, Mie University Hospital, Tsu, Japan.

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http://dx.doi.org/10.1055/a-1296-7632DOI Listing
October 2021

The spontaneous clearance of hepatitis E virus (HEV) and emergence of HEV antibodies in a transfusion-transmitted chronic hepatitis E case after completion of chemotherapy for acute myeloid leukemia.

Clin J Gastroenterol 2020 Apr 24;13(2):252-259. Epub 2019 Jul 24.

Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.

A 64-year-old woman was infected with hepatitis E virus (HEV) during chemotherapy for leukemia. By retrospective analyses of stored serum from the blood products and the patient, the source of the infection was determined to be platelet concentration (PC) transfused during chemotherapy. The partial nucleotide sequence of the HEV strain isolated from the donated PC and that from the patient's sera was identical and was subgenotype 3b. Clinical indicators such as alanine aminotransferase, HEV RNA titer, and anti-HEV antibodies in the serum were investigated from the beginning of the infection until 1 year after the termination of HEV infection. HEV RNA had propagated over 6 months and then cleared spontaneously after the completion of chemotherapy. Anti-HEV antibodies appeared in the serum just before the clearance of HEV RNA. Interestingly, HEV RNA was detected in the patient's urine, spinal fluid, and saliva. The HEV RNA titers in those samples were much lower than in the serum and feces. No renal, neurological, or salivary gland disorders appeared during the follow-up. We observed virological and biochemical progress and cure of transfusion-transmitted chronic hepatitis E in the patient despite an immunosuppressive status during and after chemotherapy against hematological malignancy.
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http://dx.doi.org/10.1007/s12328-019-01024-3DOI Listing
April 2020

Hepatic Injury without Granulomatous Formation Associated with Intravesical Bacillus Calmette-Guérin Therapy.

Intern Med 2019 May 10;58(10):1429-1432. Epub 2019 Jan 10.

Department of Pathology, Suzuka General Hospital, Japan.

A 74-year-old man developed hepatic injury after intravesical Bacillus Calmette-Guérin (BCG) therapy for bladder carcinoma. Although hepatitis-associated disseminated BCG was suspected, granulomatous formations were undetectable. The hepatic injury was considered to have resulted from an allergic reaction to BCG therapy because a histopathological assessment revealed enlarged portal areas with eosinophils and neutrophils. The hepatic injury was resolved by prednisolone. This case suggested that hepatic injury associated with BCG therapy might be due to an allergic mechanism unrelated to disseminated BCG disease. A liver biopsy is needed to confirm the histopathological findings of hepatic injury after BCG therapy in order to differentiate allergic hepatic injury from infectious hepatic injury.
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http://dx.doi.org/10.2169/internalmedicine.2073-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6548914PMC
May 2019

Early stage clear cell adenocarcinoma of the colon examined in detail with image-enhanced endoscopy: a case report.

Clin J Gastroenterol 2018 Dec 30;11(6):465-469. Epub 2018 Jul 30.

Department of Pathology, Niigata Cancer Center Hospital, 2-15-3, Kawagishicho, Chuo-ku, Niigata-Shi, Niigata, Japan.

Primary clear cell adenocarcinoma (CCA) of the colorectum is a rare tumor. We report on a 48-year-old man with early stage CCA in the descending colon who underwent detailed examination with image-enhanced endoscopy, such as magnifying endoscopy with narrow-band imaging and crystal violet staining. The tumor was treated successfully with endoscopic mucosal resection at our hospital.
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http://dx.doi.org/10.1007/s12328-018-0889-6DOI Listing
December 2018

Gastric adenocarcinoma coexisting with a reddish semipedunculated polyp arising from Helicobacter pylori-negative normal gastric mucosa: a report of two cases.

Clin J Gastroenterol 2018 Dec 18;11(6):481-486. Epub 2018 Jul 18.

Happy GI Clinic, 2-9-33 Honmachi, Kameyama, Mie, Japan.

We experienced two cases of adenocarcinoma coexisting with a hyperplastic polyp arising from Helicobacter pylori-negative normal gastric mucosa. The first case was of a 59-year-old man. Esophagogastroduodenoscopy revealed a protruding lesion measuring 4 mm in diameter on the greater curvature of the middle gastric body. The second case was of a 47-year-old man. Esophagogastroduodenoscopy showed a protruding lesion measuring 5 mm located at the greater curvature of the upper gastric body. The absence of atrophic changes in the entire gastric mucosa was confirmed endoscopically in both cases. Multiple H. pylori tests were all negative. Endoscopically, these protruding lesions appeared as reddish, semipedunculated polyps. Hyperplastic polyps were suspected based on white light endoscopic findings. Magnified endoscopy with narrow band imaging could not predict the coexistence of cancer. However, histopathological examination of the resected specimen revealed focal cancer at the surface of the gastric hyperplastic polyps. Considering the possibility that cancer may be coexisting in polyps, when reddish polyps are detected in H. pylori-negative normal gastric mucosa, it is important to perform a biopsy, or a careful follow-up endoscopy.
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http://dx.doi.org/10.1007/s12328-018-0887-8DOI Listing
December 2018

Reactivity of highly Lewis acidic diborane(4) towards pyridine and isocyanide: formation of boraalkene-pyridine complex and -functionalized pyridine derivatives.

Chem Sci 2018 Feb 11;9(5):1301-1310. Epub 2017 Dec 11.

Department of Molecular and Macromolecular Chemistry , Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa-ku , Nagoya , 464-8603 , Aichi , Japan . Email:

The reaction of pinB-BMes (pin = pinacolato, Mes = 2,4,6-MeCH) with Xyl-NC (Xyl = 2,6-MeCH) and pyridine results in the formation of a pyridine-coordinated boraalkene that exhibits an intense color caused by an intramolecular charge-transfer interaction. In the presence of an excess of pyridine, the C-H bond of pyridine was selectively functionalized to afford a quinoid compound or an isocyanide-coupled product. Based on the concentration effect, the reaction stoichiometry, and previously reported DFT calculations, a reaction mechanism that involves several rearrangement reactions was proposed. Using the present method, substituted pyridines and N-heterocycles afforded the corresponding functionalized derivatives. A subsequent hydrolysis of one of the resulting products furnished an aminomethylated pyridine derivative in two steps from parent pyridine.
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http://dx.doi.org/10.1039/c7sc04759bDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5887101PMC
February 2018

Cleaving Dihydrogen with Tetra(o-tolyl)diborane(4).

J Am Chem Soc 2017 02 10;139(7):2593-2596. Epub 2017 Feb 10.

Department of Applied Chemistry, Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa-ku, Nagoya, 464-8603 Aichi, Japan.

Tetra(o-tolyl)diborane(4), 1, was synthesized and characterized experimentally as well as theoretically by density functional theory (DFT) calculations. Exposure of 1 to H (1 bar) at room temperature afforded the corresponding di(o-tolyl)hydroborane through cleavage of the H-H and B-B bonds. DFT calculations suggested a diarylboryl anion character for the transition state.
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http://dx.doi.org/10.1021/jacs.7b00924DOI Listing
February 2017

Lowering the reduction potential of a boron compound by means of the substituent effect of the boryl group: one-electron reduction of an unsymmetrical diborane(4).

Chemistry 2015 Mar 29;21(11):4267-71. Epub 2015 Jan 29.

Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, 112-8551 Tokyo (Japan) http://www.chem.chuo-u.ac.jp/∼element/index-e.html.

We have clarified and observed the high electron affinity of pinB-BMes2 (1; Mes = mesityl, pin = pinacolato). By using electrochemistry, it was shown that 1 has a higher electron affinity than those of B2pin2 and Mes3B. One-electron reduction of 1 gave the corresponding radical anion. The ESR spectroscopy and DFT calculation revealed the unsymmetrical distribution of electron density over the B-B bond. UV/Vis spectroscopy showed that the SOMO-related absorption supports the deep purple color of the radical anion. DFT studies on the torsion angle dependency of the LUMO levels and relative energies revealed the reason why 1 has high electron affinity as a result of the substituent effect of the Bpin group.
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http://dx.doi.org/10.1002/chem.201406609DOI Listing
March 2015

Facile scission of isonitrile carbon-nitrogen triple bond using a diborane(4) reagent.

Nat Commun 2014 Jun 26;5:4245. Epub 2014 Jun 26.

Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku 112-8551, Japan.

Transition metal reagents and catalysts are generally effective to cleave all three bonds (one σ and two π) in a triple bond despite its high bonding energy. Recently, chemistry of single-bond cleavage by using main-group element compounds is rapidly being developed in the absence of transition metals. However, the cleavage of a triple bond using non-transition-metal compounds is less explored. Here we report that an unsymmetrical diborane(4) compound could react with carbon monoxide and tert-butyl isonitrile at room temperature. In the latter case, the carbon-nitrogen triple bond was completely cleaved in the absence of transition metal as confirmed by X-ray crystallographic analysis, (13)C NMR spectroscopy with (13)C labelling and DFT calculations. The DFT calculations also revealed the detailed reaction mechanism and indicated that the key for the carbon-nitrogen triple-bond cleavage could be attributed to the presence of nucleophilic nitrogen atom in one of the intermediates.
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http://dx.doi.org/10.1038/ncomms5245DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4083417PMC
June 2014
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