Shigeharu Miwa

Pathobiological characteristics of intestinal and diffuse-type gastric carcinoma in Japan: an immunostaining study on the tissue microarray.

Aim: To investigate the pathobiological features of intestinal and diffuse-type gastric carcinomas in the Japanese population. Methods: The expression of fragile histine triad (FHIT), phosphatase and tensin homology deleted from human chromosome 10 (PTEN), caspase-3, Ki-67, mutant p53, matrix metalloproteinase (MMP)-2, MMP-9, and extracellular matrix metalloproteinase inducer (EMMPRIN) on tissue microarrays of gastric carcinomas by immunostaining was examined in comparison with the clinicopathological characteristics between intestinal and diffuse-type cases. Results: Intestinal-type carcinoma frequently occurred in old men, whereas the diffuse type comparatively occurred more in young women (p<0.05). The diffuse-type carcinoma was more inclined to invasion into muscularis propria, lymphatic invasion and lymph node metastasis, and belonged to higher International Union against Cancer (UICC) staging (p<0.05) compared with intestinal-type counterparts. Expression of FHIT, PTEN, Ki-67, caspase-3, mutant p53 and EMPPRIN was higher in intestinal-type carcinomas than in diffuse-type carcinomas (p<0.05). Kaplan–Meier analysis indicated that patients with intestinal-type carcinomas had a higher cumulative survival rate (p<0.05). Conclusion: Intestinal-type gastric carcinomas with a more favourable prognosis frequently show high levels of proliferation and apoptosis, and always accompany strong expression of FHIT, PTEN and mutant p53 and EMMPRIN. EMMPRIN expression might underlie the molecular basis of liver metastasis and higher proliferation of intestinal-type gastric carcinomas in Japan. Lauren’s classification thus proved pathologically relevant for the clinical treatment of gastric carcinomas.

The liver in itai-itai disease (chronic cadmium poisoning): pathological features and metallothionein expression

Cadmium (Cd) is a highly hepatotoxic heavy metal, which is widely dispersed in the environment. Acute Cd hepatotoxicity has been well studied in experimental animals; however, effects of prolonged exposure to Cd doses on the liver remain unclear. In the present study, to evaluate chronic Cd hepatotoxicity, we examined specimens from cases of itai-itai disease, the most severe form of chronic Cd poisoning. We compared 89 cases of itai-itai disease with 27 control cases to assess Cd concentration in organs. We also examined 80 cases of itai-itai disease and 70 control cases for histopathological evaluation. In addition, we performed immunohistochemistry for metallothionein, which binds and detoxifies Cd. Hepatic Cd concentration was higher than Cd concentration in all other organs measured in the itai-itai disease group, whereas it was second highest following renal concentration in the control group. In the liver in the itai-itai disease group, fibrosis was observed at a significantly higher rate than that in the control group. Metallothionein expression was significantly higher in the itai-itai disease group than that in the control group. Prolonged exposure to low doses of Cd leads to high hepatic accumulation, which can then cause fibrosis; however, it also causes high expression of metallothionein, which is thought to reduce Cd hepatotoxicity.

Spontaneous onset of nonalcoholic steatohepatitis and hepatocellular carcinoma in a mouse model of metabolic syndrome

Metabolic syndrome is a worldwide healthcare issue and a dominant risk factor for the development of incurable diseases that affect the entire body. The hepatic manifestations of this syndrome include nonalcoholic fatty liver disease (NAFLD) and its progressive variant nonalcoholic steatohepatitis (NASH). The basic pathogenesis of NAFLD/NASH remains controversial because it is difficult to clarify the disease process of NASH on the basis of metabolic syndrome alone. To determine the pathogenesis and effective treatment, an excellent animal model of NASH is required. Tsumura Suzuki obese diabetes (TSOD) male mice spontaneously develop diabetes mellitus, obesity, glucosuria, hyperglycemia, and hyperinsulinemia without any special treatments such as gene manipulation. In this study, we examined the histopathological characteristics of visceral fat and liver of 56 male TSOD mice aged 4–17 months and 9 male Tsumura Suzuki non-obesity (control) mice aged 6–12 months. In the visceral fat, enlargement of adipocytes and perivascular and pericapsular CD8-positive lymphoid aggregation were observed in 4-month-old mice. Abnormal expression of tumor necrosis factor-α, interleukin-6, and lipid peroxidation endo products was observed in macrophages. In the liver, microvesicular steatosis, hepatocellular ballooning, and Mallory bodies were observed in 4-month-old mice, with severity worsening with increasing time. These pathological findings in the liver mimic those seen in patients with NASH. Interestingly, small liver nodules with high cellularity and absence of portal tracts were frequently observed after 12 months. Most of them showed nuclear and structural atypia, and mimicked human hepatocellular carcinoma. The degree of steatosis in the non-tumor portions of the liver improved when the liver nodules developed. These findings were not observed in control mice. Here, we report that TSOD male mice spontaneously developed NAFLD without any special treatment, and that these mice are a valuable model for assessing NASH and NASH carcinogenesis owing to metabolic syndrome.

Nonalcoholic steatohepatitis and hepatocellular carcinoma in galectin‐3 knockout mice

Aim:  Nonalcoholic fatty liver disease (NAFLD) represents a growing health concern due to its rapidly increasing prevalence worldwide. Nonalcoholic steatohepatitis (NASH) is a progressing form of NAFLD, and recently many studies have reported that it could eventually develop into hepatocellular carcinoma (HCC). We previously reported that 6‐month‐old male galectin‐3 knockout (gal3−/−) mice developed clinicopathological features similar to those of NAFLD in humans. Our aim was to investigate the changes in liver histology in gal3−/− mice by long‐term observation.

Mutation assay of the novel gene DOG1 in gastrointestinal stromal tumors (GISTs)

BackgroundRecently, the novel gene DOG1 has been found to be overexpressed in most gastrointestinal stromal tumors (GISTs) specifically within the field of soft tissue tumors. DOG1 might play a role in development of GISTs and have potential as a diagnostic marker and therapeutic target, but the biological function and the overexpression mechanism have not yet been investigated. In this study we examined whether the DOG1 gene mutation occurs as with the KIT gene and PDGFRA gene.MethodsWe investigated ten resected primary GIST tissues. All cases were examined for immunoreactivity for KIT and DOG1 and screened for mutation in the KIT gene (exons 9, 11, 13, and 17) and the PDGFRA gene (exons 12, 14, and 18) by direct DNA sequencing. Four cases with relatively good quality DNA were analyzed for the DOG1 gene (exons 1-26) mutation.ResultsAll ten GISTs showed immunoreactivity for KIT. Although all cases expressed DOG1 in immunohistochemistry, we could not find any mutations within all 26 exons (a total of 104 exons) of the DOG1 gene in the four analyzed cases.ConclusionsBased on four cases, the DOG1 gene was found not to be mutated in GISTs.

Malignant transformation of hyperplastic gastric polyps: An immunohistochemical and pathological study of the changes of neoplastic phenotype

In spite of the evidence that the malignant transformation of gastric hyperplastic polyps (HPs) is a rare event, it must always be taken into account during diagnosis. The aim of the current study was to clarify the mechanism of the malignant transformation of gastric hyperplasia polyps, with focus on phenotypic expression, cell proliferation and p53 overexpression. Immunohistochemistry for mucin phenotypic markers, including MUC1, MUC2, MUC5AC, MUC6, tight junction factors (claudin-3, -4 and -18), an intestinal phenotypic marker [caudal type homeobox 2 (Cdx2)], Ki-67 proliferative index and p53 overexpression, was performed on archival specimens of gastric polyps excised from six patients. Histologically, the intermingled components of several lesions were present in these polyps. Furthermore, the cancer components were predominantly differentiated adenocarcinoma. Immunohistochemically, all hyperplastic components expressed MUC5AC, but did not exhibit positivity for MUC2. Additionally, the majority of hyperplastic components were immunonegative for claudin-3, while claudin-3 positivity was observed in the majority of areas of dysplasia and carcinoma. Expression of claudin-4 was also observed in the majority of cases and claudin-18 was preserved in the hyperplastic, dysplastic and adenocarcinomatous lesions of all cases. Nuclear accumulation of Cdx2 was detected in almost all the samples with dysplasia and carcinoma, while nuclear p53 was detected in 24–80% of the dysplastic areas and >85% of the cancer components. The Ki-67 labeling index appeared to correlate with neoplastic progression. The observations provided evidence that the mechanism underlying malignant transformation of gastric HPs may occur by multistep carcinogenesis, such as the hyperplasia-adenoma (dysplasia)-adenocarcinoma sequence, and these neoplastic cells may acquire various phenotypes during this process.

Introduction and utility of liquid‑based cytology on aspiration biopsy of peripheral nodular lesions of the lung

In the present study, aspiration biopsy cytology (ABC) was used for the diagnosis of peripheral nodular lesions in the lung (PNLL), and liquid-based cytology (LBC) was carried out on the material collected to evaluate it in comparison with the conventional method (CM). The subjects comprised 130 cases that underwent computed tomography (CT)-guided ABC for PNLL. A total of 73 cases received a tumor resection, with a diagnosis based on the pathology, while 57 cases were followed up, as the tumor showed no change on the radiological examinations. Biopsy samples from these patients and lavage fluid from the aspiration needles were used for analysis. Cellular material was obtained by centrifugation of the lavage fluid, and samples were prepared by two methods, direct smearing and LBC according to the ThinPrep method. The samples were categorized into three diagnoses: i) Benign, ii) suspicion of malignancy and iii) malignant. Appropriate samples were collected in 72% of cases by LBC, but only in 36% of cases by the CM. There was no marked difference in cellular images between the two methods, with the exception of a few specific cases. LBC on its own provided sensitivity at 68%, specificity at 61% and accuracy at 65%, while a combination of LBC and biopsy markedly improved these figures to 94, 81 and 84%, respectively. The introduction of LBC is considered useful for the cytopathological diagnosis of PNLL by CT-guided ABC. LBC enables the examination of appropriate samples rich in cellular components and supports a biopsy-based diagnosis. A combination of these two methods provides even higher diagnostic accuracy, and LBC is considered an excellent method to evaluate these pathological samples.

Neonatal monosodium glutamate treatment causes obesity, diabetes, and macrovesicular steatohepatitis with liver nodules in DIAR mice

Non‐alcoholic steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome (MS). Monosodium glutamate (MSG)‐treated ICR mice is a useful model of MS and NASH, but it shows the different patterns of steatosis from human NASH. Because inbred aged DIAR (ddY, Institute for Animal Reproduction) mice spontaneously show the similar pattern of steatosis as NASH, we analyzed their liver pathology after administering MSG.

A simple and rapid decalcification procedure of skeletal tissues for pathology using an ultrasonic cleaner with D-mannitol and formic acid.

Decalcification procedures are required in order to prepare histopathological preparations of hard tissues such as bone and teeth. Decalcification is usually performed by immersing the hard tissue in different decalcification fluids with various properties. These decalcification fluids typically include inorganic and organic acids, a neutral fluid containing a chelating agent, or a mixture of solutions. Unfortunately, there is no universal decalcification fluid that satisfies all the requirements of pathologists such as rapid decalcification, easy handling, and minimal tissue damage. Techniques involving use of microwaves (MW) or ultrasonic apparatus (US) have been shown to be useful for shortening the time for decalcification procedures. In the present study, we investigated a unique decalcification procedure that uses a common commercial ultrasonic cleaner and a decalcification fluid (formic acid) containing a free-radical scavenger (D-mannitol). The time required to complete the procedure is approximately half of that required to complete a standard decalcification procedure. In addition, tissue morphology and antigenicity is fairly well preserved after decalcification. The procedure is quick, easy to perform, and achieves decalcification of hard tissue with minimal tissue damage.

Hepatic Sinusoidal Obstruction Syndrome Induced by Non-transplant Chemotherapy for Non-Hodgkin Lymphoma

Hepatic sinusoidal obstruction syndrome (SOS), a serious complication that mainly occurs after hematopoietic-stem cell transplantation (HSCT), is caused by damage to the sinusoidal endothelial cells after the obstruction of the sinusoid. Recently, hepatic SOS was reported to occur after non-HSCT chemotherapies. This report describes a patient who experienced hepatic SOS after non-HSCT chemotherapy for non-Hodgkin lymphoma. A liver biopsy showed the slight dilatation of the hepatic sinusoid, which may be indicative of hepatic SOS. Hepatic SOS should be included in the differential diagnosis of patients with severe liver injury following the administration of chemotherapy regimens that are toxic to the vascular endothelial cells.