Akihiro Hemmi

Expression of vascular endothelial growth factor (VEGF) in human thyroid neoplasms

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), is an angiogenic factor that plays important roles in tumor growth. Angiogenesis studies on VEGF deal with various types of malignant tumors, but very little is known about the role or significance of VEGF in human thyroid neoplasms. Therefore, in the current study, we determined whether VEGF is found in normal and neoplastic thyroids and whether its expression is altered in different histological types of thyroid neoplasms. Reverse-transcription polymerase chain reaction (RT-PCR) analysis showed that all specimens of thyroid tumors expressed bands corresponding to 121-, 165-, and 189-amino acid forms of VEGF. Northern blot analysis showed an increase in VEGF mRNA levels in neoplastic tissues in comparison with normal thyroid samples. By nonisotopic in situ hybridization, most of the tumor cells in follicular adenomas expressed VEGF mRNA, whereas VEGF mRNA expression was identified only in epithelium of isolated follicles in normal thyroid tissues. In papillary thyroid carcinomas, an intense labeling with VEGF probe was often found in overlying tumor cells of neoplastic papillae. VEGF expression was distinctly intensified in undifferentiated carcinoma cells that were immediately adjacent to necrotic foci. The immunohistochemical localizations of VEGF protein were comparable to the localization of VEGF mRNA. In conclusion, our results suggest that the histological types of thyroid tumor may determine the vascular pattern through a paracrine mechanism involving VEGF.

Survivin as a prognostic factor for osteosarcoma patients.

Purpose: Survivin is one of the apoptosis inhibitor genes and is rarely expressed in adult tissues. However, survivin expression has been detected in various human cancers and correlations have been recognized between the level of expression of this gene in tumors and prognosis. In this study, we investigated the correlations between survivin mRNA expression in osteosarcoma tissues and clinicopathological parameters. Methods: There were 22 osteosarcoma patients in our hospital with paraffin-embedded tissues which could be extracted from biopsy specimens. We used the RT-PCR method after extracting total RNA and conducted a densitometric analysis to determine the ratio of survivin relative to h-GAPDH as an internal marker. Results: Expression of survivin mRNA was detected in all osteosarcoma samples. Patients with metastasis had high survivin mRNA levels in initial biopsy specimens (p<0.01). Moreover, there was a statistically significant difference in survivin mRNA expression between patients with and without metastasis (p<0.01). Conclusion: We concluded that high levels of survivin mRNA expression suggest poor prognosis for osteosarcoma patients.

MALIGNANT PLEOMORPHIC ADENOMA (MALIGNANT MIXED TUMOR) OF THE TRACHEA. Report of a Case

Malignant pleomorphic adenoma arising in the trachea has not been reported in the literature. We report here a case of malignant pleomorphic adenoma (malignant mixed tumor) occurring in the trachea of a 65‐year‐old woman. The tumor metastasized to the lung and the chest wall 11 years after complete resection of the primary tumor, which was a polypoid submucosal tumor, 1.3 cm in diameter. Light microscopic examination of the primary and metastatic tumors showed the presence of epithelial and stromal elements, consisting of grandular structures, foci of squamous metaplasia and a myxochondroid stroma. Many tumor cells showed myoepithelial cell features by electron microscopy, and immunoreactivity for S‐100 protein and GFAP was also seen in many of them. These findings were consistent with those of pleomorphic adenoma. However, the epithelial elements were cytologically atypical with prominent mitotic figures. Infiltration of the tumor cells into the surrounding soft tissue was also seen. No foci of benign pleomorphic adenoma were found in the primary tumor. These findings indicate that this tumor was not a carcinoma ex pleomorphic adenoma, but a true malignant pleomorphic adenoma (true malignant mixed tumor) of the trachea. ACTA PATHOL JPN 38: 1215∼1226, 1988.

Tc-99m-MIBI scintigraphy for detecting parathyroid adenoma and hyperplasia

We performed scintigraphy with technetium-99m-methoxyisobutylisonitrile (MIBI) in 10 patients with parathyroid adenoma (7 lesions) or hyperplasia (9 lesions). Correlation between an amount of accumulation of MIBI and histological types of the lesions were evaluated with special reference to an amount of oxyphilic cell in the lesions. Selected lesions were also evaluated for mitochondrial density by electromicroscopy and showed increased mitochondrial density in the oxyphilic cells. All lesions equal to or above 220 mg showed positive scintigraphic results despite differences in cell types. Undetected lesions were all equal to or below 100 mg. The scintigraphic results for 2 lesions with abundant oxyphilic cells were both positive although those for 11 lesions with abundant chief cells only 6 were positive, probably because these lesions were smaller in the hyperplasia group. In conclusion, MIBI uptake in parathyroid lesions was not dependent on the cell type but either on the size or functional state of the lesions.

Osteopontin expression in ulcerative colitis is distinctly different from that in Crohn’s disease and diverticulitis

BackgroundThe aim of the present work was to assess osteopontin (OPN) expression in the colon tissues of ulcerative colitis (UC), Crohn’s disease (CD), and diverticulitis (Div) patients.MethodsThis study included three groups: the UC group, CD group, and Div group. Immunohistochemical staining was performed, using an immunoperoxidase method.ResultsRegarding OPN expression in intestinal epithelial cells, no difference was noted among the three groups. However, in the submucosa of the UC group, the ratio of two types of large cells (oval and spindle-shaped) expressing OPN was 61.2 ± 14.4% (mean ± SD), which was significantly higher than that in the CD group (14.9 ± 7.0%; P < 0.05) and that in the Div group (11.2 ± 6.1%; P < 0.05). In addition, in the UC group, the ratio of these cells in the subserosa (50.1 ± 15.0%; mean ± SD) was significantly higher than that in the CD group (16.9 ± 6.2%; P < 0.05) and that in the Div group (12.6 ± 5.7%; P < 0.05). In a serial section study, the oval-shaped cells were stained for anti-CD 68, while the spindle-shaped cells were stained for anti-vimentin.ConclusionsOPN in two types of large colon-infiltrating cells is possibly related to one of the pathogenic factors of UC.

Poorly differentiated desmin-negative and vimentin-positive leiomyosarcoma of the stomach examined by the immunohistochemical and quick-freezing and deep-etching methods

Abstract A poorly differentiated leiomyosarcoma of the stomach in a 41-year-old woman is reported. The diagnosis was confirmed by the diffuse immunohistochemical reaction to HHF35, and the presence of focal density and caveolas in some of the tumour cells by conventional electron microscopy. Immunohistochemically, most tumour cells had an undifferentiated nature, in which negative immunostaining for desmin, alpha-smooth muscle actin, and type IV collagen, and positive immunostaining for vimentin were observed. By the quick-freezing and deep-etching (QF-DE) method, these tumour cells revealed the loss of bundled actin and myosin filaments, which constitute desmin associated structures (focal densities and dense patchy areas). Their cytoplasm had many mitochondria and other cell organelles. The intermediate filaments (IFs), which were determined to be vimentin by immunohistochemistry, were observed in the inter-organellar spaces, and connected with these cell organelles. Actin filaments formed a meshwork structure and were distributed mainly in subplasmalemmal regions. Although a basal lamina was not detected by conventional electron microscopy, basal lamina-like structures, an association between the extracellular matrices and the cell membrane, were observed. Using the QF-DE method, three dimensional ultrastructural alterations of the cytoskeleton and extracellular matrix of the leiomyosarcoma were observed.

Nature and significance of calcium oxalate crystals in normal human thyroid gland A clinicopathological and immunohistochemical study

To elucidate the significance and nature of calcium oxalate crystals in the thyroid, we studied these crystals clinicopathologically and immunohistochemically in 182 normal thyroids from patients autopsied within 5 h of death. Under polarized light, calcium oxalate crystals showed brilliant birefringence and were invariably found within the colloid. The crystals were found in 73.1% of all cases but were more prevalent and denser in older individuals, with the highest prevalence (85.2%) being observed in those over 70 years of age. No crystals were seen in those under 10 years of age. Although underlying diseases seemed to have little influence, post-mortem delay apparently affected the prevalence and density of occurrence since the crystals tended to disappear with hours after death. An immunohistochemical study using anti-thyroid hormone antibodies revealed that the crystals were within negatively or weakly stained colloid and were not common in strongly stained colloid. These findings support the hypothesis that the occurrence of calcium oxalate crystals in normal human thyroid is associated with a low functional state of the thyroid follicles.

Different organization of intermediate filaments in columnar cells of rat large intestinal mucosa as revealed by confocal laser scanning microscopy and quick-freezing and deep-etching method.

The relationship between cell differentiation and ultrastructural changes of intermediate filaments (IF) was studied in columnar cells of large intestinal mucosa of rats by confocal laser scanning microscopy and quick-freezing and deep-etching method. A feature of the IF in immature columnar cells was minibundle formation with prominent branching, which organized the meshwork structures. The minibundles, which appeared to be formed by the attachment of two or more IF in side-to-side fashion, were loosely distributed throughout the cytoplasm. In contrast, in mature columnar cells, the IF were densely distributed under the terminal web in the cytoplasm and beneath the upper part of the lateral membrane regions, whereas the other areas of the cytoplasm contained only a small number of IF. Minibundle formation was not observed, and the branching was rarely identified. The changes in the distribution and density of IF, which are expressed in specific areas of mature columnar cells, apparently represent a characteristic of intracellular differentiation. It is suggested that the dissociation of minibundled IF, which was often observed in the immature columnar cells, is an important step in the acquisition of functional polarity in cells of this type.

Immunohistochemical Study of Cytokeratin Distribution in the Collecting Duct of the Human Kidney

In order to assess the expression of different cytokeratins in the collecting duct cells (CDCs) of the human kidney, three consecutive sections were stained with periodic acid‐Schiff, CAM 5.2, and AE‐1 (CAM 5.2 recognizes cytokeratins #19,18,8 and AE 1 #19,16,15,14,10 of Molls catalog.), respectively. By comparing these sections, it was found that most CDCs in the inner medulla were both CAM 5.2 and AE 1 positive, whereas in the outer medulla and cortex, 77% of the CDCs were both CAM 5.2 and AE 1 positive, 15% CAM 5.2 positive and AE 1 negative, 8% both CAM 5.2 and AE‐1‐negative, and 0.4% CAM 5.2 negative and AE 1 positive. Recent studies have shown that most CDCs express low‐molecular weight cytokeratins #7,8,18 and 19(17,18,19,20). Of these cytokeratins, CAM 5.2 recognizes cytokeratins #8,18,19 and AE‐1 recognizes cytokeratin #19. Therefore, most CDCs belong to one of the following three major types; 1. Those positive for cytokeratins #8,18 and 19 (CAM 5.2 and AE 1 positive), 2. Those positive for cytokeratins #8 and 18 and negative for #19 (CAM 5.2‐positive and AE 1 ‐negative) and 3. Those negative for cytokeratins #8,18 and 19 (CAM 5.2 and AE 1 negative). A few CAM 5.2 negative and AE 1 positive cells were thought to express high molecular weight cytokeratins. The significance of these various cytokeratin expressions is discussed. Acta Pathol Jpn 41: 516 520, 1991.

Long term changes in platelet counts after H. pylori eradication in non-ITP patients

Helicobacter pylori eradication is becoming a first-line therapy against idiopathic thrombocytopenic purpura (ITP) and its long term efficacy has already been reported. In contrast, eradication therapy reduced peripheral platelets in non-ITP patients 8 weeks later. To confirm the long term efficacy of Helicobacter eradication on platelet counts in non-ITP patients, we evaluated changes in peripheral platelet counts in endoscopically diagnosed patients with Helicobacter infection. Endoscopically diagnosed patients with Helicobacter infection received eradication therapy using amoxicillin (1500 mg/day), clarithromycin (400 mg/day) and lansoprazole (60 mg/day). The changes in platelet counts after Helicobacter eradication were serially evaluated for as long as 3 years or more. In total, 294 patients were enrolled: 243 patients successfully received eradication therapy and 51 were unsuccessfully treated. As a whole, peripheral platelet counts significantly decreased after Helicobacter eradication, being reduced by more than 1.0 × 109/l by 5–6 months, 1 year, 2 years and 3 years or more (from 24.2+/−5.6 to 23.1+/−5.0, 23.0+/−5.0, 22.1+/−4.5, 22.4+/−5.6, and 21.6+/−5.3 × 109/l: p = <0.0001, <0.0001, 0.0001, 0.0052, and <0.0001, respectively). Helicobacter pylori eradication finally reduced peripheral platelet counts around 2.0 × 109/l in non-ITP patients. There was a definite difference in platelet regulation by Helicobacter pylori between ITP and non-ITP patients. These bivalent effects, upregulation and downregulation, on the peripheral platelet induced by Helicibacter pylori infection appeared to originate from quite different mechanisms.