Biomedical subjects

Michihiro Suzuki

Publications and source records attributed to Michihiro Suzuki.

23 records · Page 2Linked to original sources

PubMed2002

A case of complete necrosis of well-differentiated early hepatocellular carcinoma by percutaneous transhepatic portal embolization.

The patient was a 49-year-old male under observation for chronic hepatitis B. In July 1997, abdominal ultrasonography showed multiple hyperechoic nodules in the right lobe, the largest with a diameter of 3.5 cm. Abdominal computed tomography did not reveal enhanced nodules, and the patient was hospitalized for suspected multiple liver tumors. All biochemical tests were normal, except for a slight decrease in platelets. The patient was positive for HBs antigen, negative for HBe antigen and positive for anti-HBe antibody. Hepatocellular carcinoma (HCC) with patent portal blood flow was strongly suspected based on the results of various imaging techniques. A tumor biopsy was conducted, and findings of multiple early hepatocellular carcinoma of a well-differentiated type were observed. Based on the HCC stage and liver function, an extensive right hepatectomy was indicated. Before the surgical resection, a percutaneous transhepatic portal embolization (PTPE) was performed using gerfoam sponzel in the right portal vein. Complete necrosis of the tumor lesions was observed in the resected liver. Early HCC thought to have developed multifocally concurrently with chronic inactive hepatitis was observed. It is highly possible that complete necrosis of these tumors occurred due to PTPE, suggesting that they are supplied by the portal blood flow.

Journal Article↗

PubMed2002

Esophageal extraskeletal Ewing's sarcoma.

Extraskeletal Ewing's sarcoma is a rare tumor. The most common sites of occurrence are on the trunk, extremities, and retroperitoneum. This type of tumor is well characterized by recurrent chromosomal translocation such as t (11;22) (q24;q12) (EWSR1/FLI1) or t (21;22) (q22;q12) (EWSR1/ERG) and overexpression of MIC2/CD99 on tumor cell membrane. We describe the first reported case of an esophageal extraskeletal Ewing's sarcoma with confirmation from immunohistochemical and molecular diagnoses. A 56-year-old man developed a polypoid tumor located in the lower part of the esophagus. The tumor was composed of small-sized round cells showing prominent fibrillar cytoplasmic processes. Intracytoplasmic glycogen was detected in all the tumor cells. Immunoreactivity for MIC2/CD99 was positive on the membrane of all tumor cells. A reverse transcriptase-polymerase chain reaction followed by sequencing revealed an EWSR1/ERG chimeric transcript, which combined EWSR1 exon 10 with ERG exon 6. The present report added a new entity of esophageal small round cell tumor.

12E7 Antigen↗

PubMed2002

Effects of isopropyl unoprostone and latanoprost on melanogenesis in mouse epidermal melanocytes.

PURPOSE: The authors sought to investigate the cellular mechanism of melanogenesis by prostaglandin antiglaucomatous compounds, isopropyl unoprostone (referred to as unoprostone) and latanoprost, and to quantitatively compare their effect on melanogenesis using cultured mouse epidermal melanocytes. METHODS: M1, M2, and the acid of latanoprost, all of which are possible intraocular metabolites of unoprostone or latanoprost, were used. Tested prostaglandin-related compounds (final concentration range, 1 micromol/L-10 nmol/L) were administrated to the culture medium of purely cultured mouse melanoblasts, melan-A, once daily for 2 weeks. One micromole per liter prostaglandin F(2 alpha) solution was administered in parallel. Radioisotope assays were used to measure the total melanin synthesis and the activity of tyrosinase in converting tyrosine to L-3,4-dihydroxyphenylalanine, which is a rate-limiting reaction in melanogenesis. The effects of prostaglandin F(2 alpha), M1, or M2 on proliferation of melan-A were examined. RESULTS: M1, M2, and acid of latanoprost but not prostaglandin F(2 alpha), significantly enhanced tyrosinase activity. M2 and acid of latanoprost more greatly enhanced tyrosinase activity than did M1. None of the tested compounds significantly altered the proliferation and total melanin synthesis of melan-A. CONCLUSIONS: Both unoprostone and latanoprost enhanced tyrosinase activity. These prostaglandin-related compounds may influence the nature of melanin and result in pigmentation.

Animals↗

PubMed2002

Outcomes of small nodular lesions in heavy drinkers.

BACKGROUND: Increased detection of nodular lesions in patients not yet definitively diagnosed with hepatocellular carcinoma (HCC) has occurred with the use of advanced imaging techniques. In heavy drinkers, decrease in the size of nodular lesions during on-going observation, and negation of diagnoses of HCC after surgical resection have been reported, suggesting the need for caution in diagnosis in such cases. METHODS: The subjects were eight heavy drinkers with small nodular lesions, 20 mm or less in diameter. All patients were male, with a mean age of 53 years. Five had single and three had multiple nodular lesions. Five of the eight patients were followed up for more than 4 years after an initial biopsy, while three patients were recent cases. Of the three recent cases, two were positive for antibody to hepatitis C virus (HCV) and two had hypervascular nodular lesion. Biopsies were performed percutaneously, under ultrasonography, for histological diagnosis of all cases, and the recent cases were also assessed using a variety of imaging techniques. RESULTS: On initial biopsy, no atypism (NO) was found in two patients, and borderline lesions (Border) were present in six patients. Of the five cases followed up long-term, only one of the two with NO progressed to HCC, and the three with Border showed disappearance, decrease, and no change, respectively, during the follow-up period. Of the three recent cases, no changes in size or morphology as revealed by imaging were observed following biopsy. CONCLUSIONS: In heavy drinkers, no fixed relationship was observed between initial biopsy finding and clinical course, suggesting that indication for biopsy requires reassessment, refinement, and discussion. Furthermore, tumor staining may occur in hyperplastic nodules, which are histologically similar to early HCC by needle biopsy, and care needs to be exercised for diagnosis in heavy drinkers.

Biopsy↗

PubMedDate not supplied

Quantitative multilevel mapping of hepatic blood flow by xenon computed tomography using aorta.

A noninvasive and quantitative technique has been developed to measure human hepatic blood flow by xenon computed tomography (Xe-CT). Accurate data on time-dependent xenon concentrations in the arterial blood are indispensable for Xe-CT to ensure quantitativeness of measured blood flow. A method has been established by our group to use both aorta and end-tidal data to obtain arterial xenon information. Multilevel (3 levels) maps of arterial blood flow (Fa), portal blood flow (Fp), and partition coefficient (lambda) were created for patients with chronic hepatitis. A method to objectively evaluate Fa, Fp, and lambda values for the whole liver has also been developed by our group.

Aorta↗