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Dive into the research topics where Hiroto Wakabayashi is active.

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Featured researches published by Hiroto Wakabayashi.


Journal of Gastroenterology and Hepatology | 1993

Subcutaneous seeding of small hepatocellular carcinoma after fine needle aspiration biopsy

Nobuo Yamada; Haruhide Shinzawa; Katsuaki Ukai; Hiroto Wakabayashi; Hitoshi Togashi; Tsuneo A. Takahashi; Nobuo Seo; Shuichi Ishiyama; Masaru Tsukamoto; Shigemi Fuyama

Ultrasonically guided fine needle (21 gauge) aspiration biopsy (FNAB) was performed on a patient with a hepatocellular carcinoma (HCC) measuring 1.5 × 1.5 cm in segment VI of the liver. The tumour was located just beneath the liver surface. Subsegmentectomy of segment VI was performed. Twelve months after the biopsy and 10 months after the operation, levels of alpha‐fetoprotein (AFP) and protein induced by Vitamin K absence or antagonist‐II (PIVKA‐II) increased gradually without any evidence of recurrence of HCC in the liver. Thirteen months after the biopsy, the patient palpated a hard subcutaneous nodule 1.5 cm in diameter in the right lower anterior chest wall at the insertion site of the biopsy needle. A subcutaneous tumour was excised and histological examination revealed moderately differentiated HCC. The levels of AFP and PIVKA‐II normalized thereafter. These tumour markers were therefore useful for diagnosing the subcutaneous nodule as a metastatic HCC. The patient is currently doing well without further recurrence of HCC or needle‐tract seeding 23 months after subsegmentectomy and 11 months after excision of the subcutaneous tumour.


Journal of Hepatology | 1990

Activities of free oxygen radical scavenger enzymes in human liver

Hitoshi Togashi; Haruhide Shinzawa; Hiroto Wakabayashi; Toichiro Nakamura; Nobuo Yamada; Tsuneo Takahashi; Makoto Ishikawa

Activities of superoxide dismutase, catalase and glutathione peroxidase were measured in liver biopsy specimens from patients with various liver diseases, including six with chronic persistent hepatitis, nine with chronic active hepatitis, nine with non-alcoholic cirrhosis, eight with alcoholic cirrhosis and eight with acute hepatitis. Measurements from ten patients without liver disease were used as controls. Levels of total superoxide dismutase activity in the chronic active hepatitis and non-alcoholic cirrhosis groups were significantly lower than those in the controls (p less than 0.01 and p less than 0.01, respectively). The level of total superoxide dismutase activity in the acute hepatitis group was significantly higher than that in the control group (p less than 0.01). The levels of Cu,Zn-superoxide dismutase activity in all the experimental groups, except for the chronic persistent hepatitis group, were significantly lower than those in the controls (p less than 0.01 in all groups). The levels of Mn-superoxide dismutase activity in the alcoholic cirrhosis and acute hepatitis groups were significantly higher than those in the controls (p less than 0.01 and p less than 0.01, respectively), although no difference in the level of this enzyme was seen among the controls, chronic persistent hepatitis, chronic active hepatitis and non-alcoholic cirrhosis groups. The levels of catalase activity in the groups with chronic active hepatitis, non-alcoholic and alcoholic cirrhosis and acute hepatitis were significantly lower than those in the controls (p less than 0.01 in all groups). Glutathione peroxidase activity showed no difference among the groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Digestive Diseases and Sciences | 1994

Treatment of symptomatic hepatic cysts by percutaneous instillation of minocycline hydrochloride

Nobuo Yamada; Haruhide Shinzawa; Katsuaki Ukai; Naohiko Makino; Takaaki Matsuhashi; Hiroto Wakabayashi; Hitoshi Togashi; Tsuneo Takahashi

Nine patients with 16 symptomatic nonneoplastic congenital hepatic cysts were treated prospectively by ultrasonically guided percutaneous minocycline hydrochloride injection, and the usefulness of this treatment was evaluated. Seven of the patients had multiple hepatic cysts, and two solitary cysts. All the patients were women, ranging in age from 36 to 81 years. After cystic fluid had been aspirated with a 21-gauge PTC needle, minocycline hydrochloride was injected into all the cysts. The minocycline hydrochloride was dissolved in saline at a concentration of 200 mg in 9 ml, and mixed with 1 ml of 2% mepivacaine hydrochloride. The total quantity of minocycline hydrochloride injected varied from 100 mg to 1200 mg per hepatic cyst, depending on its size. Total or subtotal regression of the cysts was observed in all patients during follow-up periods ranging from 15 to 35 months. Seven patients became symptom-free, one showed symptom reduction, and one showed no change in symptoms. Minor side effects, eg, transient abdominal pain, slight right shoulder pain, and temperature elevation, were noted in three patients respectively. On the basis of these results, we conclude that ultrasonically guided percutaneous minocycline hydrochloride injection is useful for the treatment of symptomatic hepatic cysts.


Journal of Gastroenterology and Hepatology | 1997

Case Report: Interferon induced coma in Sheehan's syndrome

Katsuhiro Mabe; Haruhide Shinzawa; Keiichi Yamatani; Tadashi Takeda; Masamichi Ishibashi; Nobuo Yamada; Hiroyuki Misawa; Hiroto Wakabayashi; Hitoshi Togashi; Tsuneo Takahashi

A 54‐year‐old woman who was being treated with 10 million units (mu) of natural interferon (IFN)‐α per day for chronic active hepatitis C at a local clinic, developed coma on the fourth day of treatment. On admission to Yamagata University Hospital, she was still in a state of semicoma with severe hyponatraemia (122 mEq/L) and hypochloraemia (89 mEq/L). After the administration of electrolytes, her condition improved remarkably. Endocrinological loading tests showed a hypofunction of the anterior pituitary gland. In consideration of these results, and her past experiences of haemorrhage during childbirth and subsequent amenorrhoea, we diagnosed her illness as a coma as a result of Sheehans syndrome which had become overt during IFN therapy. She recovered completely after treatment with hydrocortisone and 1‐thyroxine.


Gastroenterologia Japonica | 1989

Fundamental and clinical studies on fluorescence laparoscopy after intravenous injection of fluorescein-sodium

Hiroto Wakabayashi; Haruhide Shinzawa; Hirotaka Toda; Tsuneo Takahashi; Makoto Ishikawa

SummaryIn rats with experimental liver injuries and humans with various liver diseases, fluorescence from the liver surface after intravenous injection of 10% fluorescein-sodium was investigated. Our improved fluorescence laparoscopy allowed clear fluorescent images. In normal rats and in cases of nonspecific reactive hepatitis, fluorescence was first found in the portal area of the liver surface; it was then observed spreading into the lobules towards the central veins. In damaged livers of both rats and humans, bright fluorescence was observed in arterioles, necrotic foci, and fibrotic areas on the liver surface. The patterns of fluorescence which appeared in the early phase after intravenous injection of fluorescein-sodium seemed to reflect the shapes and distribution patterns of the portal areas. These results suggest that observations with improved fluorescence laparoscopy are useful for diagnoses of liver diseases.


Gastroenterologia Japonica | 1988

Computerized morphometry of liver cells in diffuse hepatic diseases

Hiromichi Shimazu; Haruhide Shinzawa; Hitoshi Togahi; Hiroto Wakabayashi; Nobuo Yamada; Toichiro Nakamura; Tsuneo Takahashi; Makoto Ishikawa

SummaryComputerized morphometrical measurements were made of liver cells and their nuclei taken from livers of healthy persons and from patients with acute hepatitis (AH), chronic hepatitis (CH), and liver cirrhosis (LC). Liver biopsies were performed on 127 people (24 convalescing from acute hepatitis, 20 with chronic inactive hepatitis (CIH), 24 with chronic active hepatitis (CAH), 38 with liver cirrhosis (LC) and 21 who were healthy controls (HC)). The specimens were stained with hematoxylin-eosin, then light microscopic pictures were obtained.The original cells were magnified 1000 times. The sizes of the cells and of their nuclei were calculated using a computer. Correlative variation was noted in cell and nuclear sizes resulting in an consistently constant nucleus-cytoplasm ratio. Average sizes of both cells and nuclei were maximal in livers with LC, followed in decreasing order by those in livers with CAH, CIH, HC and convalescent AH. The smallest cells and nuclei were found in convalescent AH cases. It might be possible to some degree to obtain gross impressions of the histopathological type of the liver lesion by measuring the sizes of cells and nuclei of the liver.


Digestive Endoscopy | 1992

Quantitative Measurement of Fluorescent Intensity of the Rat Liver Surface Using Video Fluorescence Laparoscopy Following Intravenous Fluorescein Injection

Hiroto Wakabayashi; Haruhide Shinzawa; Hirotaka Toda; Ichiro Aoyama; Makoto Kuboki; Masamichi Ishibashi; Takahumi Saitoh; Katsuaki Ukai; Nobuo Yamada; Hitoshi Togashi; Tsuneo Takahashi; Makoto Ishikawa

Abstract: A new method for the quantitative measurement of fluorescent intensity of the rats liver surface after fluorescein injection is described. The measuring system of fluorescent intensity on the rat liver surface consisted of a video laparoscopy with a video densitometer. An excitation filter was placed in the light source and an absorbing filter was attached to the eyepiece of the magnifying scope in this fluorescence video laparoscopy system. Fluorescein was injected intravenously into the inferior vena cava. Video fluorescence images of the liver surface were recorded with a CCD TV camera which was connected to the scope. In measuring the mean intensity of video images, a region of interest was designated on the TV monitor. The fluorescent intensity in this region was measured by a video densitometer and expressed in volts. The time‐intensity curve was graphically presented using a pen recorder. In this way, the time course of the liver surface fluorescent intensity could be analyzed with data expressed in volts. In normal livers, the fluorescent intensity began to rise 4.0 ± 0.5 seconds after fluorescein injection and reached a peak at 14.4 ± 1.5 seconds. Thereafter, the intensity fell slightly but then rose again to a second peak 170±50 seconds after injection.


Hepatology | 1991

Superoxide is involved in the pathogenesis of paraquat‐induced injury in cultured rat liver slices

Hitoshi Togashi; Haruhide Shinzawa; Hiroto Wakabayashi; Toichiro Nakamura; Huang Yong; Nobuo Yamada; Katsuaki Ukai; Yoshimi Okuyama; Tsuneo Takahashi; Makoto Ishikawa


Histology and Histopathology | 1989

Ultrastructural localization of Cu, Zn-SOD in hepatocytes of patients with various liver diseases.

Katsuaki Ukai; Hitoshi Togashi; Makoto Ishikawa; Tsuneo A. Takahashi; Takafumi Saito; Haruhide Shinzawa; Yutaka Imai; Michio Dobashi; Hiroto Wakabayashi


Kanzo | 1987

A study of superoxide dismutase activity in the liver tissue and the serum of the patients with viral hepatitis.

Hitoshi Togashi; Haruhide Shinzawa; Hiroto Wakabayashi; Nobuo Yamada; Touichirou Nakamura; Katuaki Ukai; Takafumi Saitoh; Tsuneo A. Takahashi; Makoto Ishikawa; Mitunori Yamakawa; Yosihiko Oyanagui

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