Kazuhiro Satonaka

The Role of DNase and EDTA on DNA Degradation in Formaldehyde Fixed Tissues

Degradation and extraction of high molecular weight DNA from formaldehyde fixed tissues suitable for gene analysis are presented. We previously reported that DNase might play an important role in the degradation of DNA extracted from formaldehyde fixed tissues (Tokuda et al. 1990). In the present study, DNase activity of the supernatant from rat tissues fixed in buffered formaldehyde at room temperature was negligible within 3 hr. Analysis of DNA extracted from reconstituted chromatin revealed that the degradation increased in the absence of DNase depending on the duration of the formaldehyde fixation. Furthermore, high molecular weight DNA could be extracted from tissues devoid of DNase activity fixed in buffered formaldehyde containing EDTA. These results demonstrated that DNA degradation was due mainly to a mechanism other than DNAse which was inhibited by EDTA. For clinical application, v-H-ras gene was successfully detected by Southern blotting from rat spleen tissues fixed in buffered formaldehyde especially at 4 C. Fixation at low temperature is useful for gene analysis.

Immunohistochemical study of epidermal growth factor and transforming growth factor-β in the penetrating type of early gastric cancer

We report that the penetrating type of early gastric cancer (PEN) is a specific type of early gastric cancer and that the poorly differentiated PEN type could be considered an initial lesion of linitis plastica-type cancer. We performed an immunohistochemical study to clarify the role of growth factors (epidermal growth factor [EGF] and transforming growth factor-beta [TGF-beta]) in the PEN type of early gastric cancer. The results indicated that the PEN type of early gastric cancer has a high growth capacity. Moreover, it was suggested that EGF was involved in its specific infiltrative growth and that both EGF and TGF-beta were involved in its specific scirrhous growth. From these findings, it was assumed that the immunohistochemical staining of EGF and TGF-beta in endoscopic biopsy specimens was useful for the diagnosis of the PEN type of gastric cancer and also for the diagnosis of the initial lesion of linitis plastica-type gastric cancer.

P53 MUTATIONS IN FLAT- AND POLYPOID-TYPE COLORECTAL TUMORS DETECTED BY TEMPERATURE-GRADIENT GEL ELECTROPHORESIS

Reports of cases of flat-type colorectal tumors are increasing in Japan, but almost nothing has been elucidated about the genetic abnormalities of these tumors. In this study, we have examined p53 mutations in six cases of colon cancer cell lines, 22 cases of flat-type colorectal tumors, and 27 cases of polypoid-type colorectal tumors using the polymerase chain reaction (PCR) and temperature-gradient gel electrophoresis (TGGE); the latter has recently been developed as a screening method for gene mutations. p53 mutations were observed in four colon cancer cell lines, six flat-type colorectal tumors, and three polypoid-type colorectal tumors, all of which were analyzed by direct sequencing. These mutations were observed only in adenomas with high-grade dysplasia and in colorectal cancers but not in adenomas with low-grade dysplasia. These observations suggest that p53 gene mutations are involved in flat-type as well as polypoid-type colorectal tumors at relatively later stages of carcinogenesis and that TGGE seems to be useful as one of the rapid screening methods.

Analysis of Helicobacter pylori vacA gene and serum antibodies to VacA in Japan.

Vacuolating cytotoxin, VacA, is one of the most important pathogenetic factors produced by Helicobacter pylori. However, it is not clear whether the diversity in disease outcome may be ascribed to variations in strain and/or to the host responses to virulence factors. In this study, we analyzed the vacA middle region sequence among 65 Japanese isolates to clarify the variation in strain and assayed antibody titer to VacA by ELISA using purified VacA to evaluate the host response to cytotoxin. The nucleotide sequence identities compared among Japanese isolates were 92.8 ± 3.56%, and compared to 88.3 ± 2.89% in tox+ strains reported in GenBank. Positive correlation was found between the antibody titers and the severity of atrophic change of the stomach. In Japan the nucleotide sequences of the vacA middle region were highly homologous and genetically closer to tox+ strains. Antibody titers and host response to cytotoxin may be associated with atrophy of the stomach.

Different origin of leiomyoblastoma by immunohistochemical study

SummaryLeiomyoblastoma has been regarded as a neoplasm of smooth muscle origin. With recent progress in immunohistostaining techniques, many clinicopathological discrepancies have been pointed out about the origin of leiomyoblastoma. It has been claimed that gastrointestinal non-epithelial tumors should be regarded as stromal tumors in order to study their origin. In the present study, we performed various forms of immunohistostaining in seven cases of leiomyoblastoma to determine their origin. One case expressed desmine and muscle specific actin and was considered to be derived from smooth muscle. Four neoplasms expressed S-100 protein (two cases were also NSE positive) and were thought to be derived from the nerve. Two cases were of unknown derivation. These results suggest that the cells of leiomyoblastoma may arise from a primitive to totipotential cell of neural lineages that may anomalously express smooth muscle filaments.

The Specificity of the Penetrating and the Superficial Spreading Types of Early Gastric Cancer—Classification of Early Gastric Cancer Using the Interactive Image Analysis System—

Abstract: Specific types of early gastric cancer were investigated in accordance with the cancer surface area and the degree of penetration by means of quantitative measurements of the surface area of early gastric cancer using the interactive image analysis system.

Immunohistochemical Study of Estrogen Receptor in the Penetrating Type of Early Gastric Cancer

Abstract: The estrogen receptor was studied in a total of 42 cases of gastric carcinoma which included 14 cases of the penetrating type of early gastric carcinoma (PEN), 14 cases of the common type of early gastric carcinomas (EA) and 14 cases of the advanced gastric carcinomas (AD). An immunohistochemical study using the anti‐ER‐D5 antibody revealed that the detection of estrogen receptor‐positive tumor cells was significantly higher in the PEN group and in the AD group than in the EA group. Moreover, the incidence of estrogen receptor immunoreactivity in infiltrative and scirrhous PENs was significantly higher than that in non‐infiltrative and non‐scirrhous PENs. These results suggests that the estrogen receptor may play an important role in infiltrative proliferation and scirrhous growth in the PENs. Furthermore, the results indicated that ER immunostaining procedures applied to endoscopic biopsy specimens could be useful for the endoscopic diagnosis of PEN‐type early gastric cancer.

Development of a Submucosal Tumor‐like Protrusion at the Site of a Gastric Ulcer during H2‐Blocker Treatment—Report of a Case—

Abstract: We studied a patient with a gastric ulcer in which the entire ulcer protruded like a submucosal tumor. Candida albicans was observed in the biopsy specimen taken during treatment with cimetidine; the tumor disappeared after treatment with an antifungal agent, both topically and orally. The patient was a 68‐year‐old male who had undergone periodical endoscopic examinations of his upper digestive tract although he did not complain of any subjective symptoms. He was admitted to Suma Red Cross Hospital because examination revealed an active ulcer on the greater curvature of the fornix of the stomach. The patient was treated with 800mg/day of cimetidine. After ten days of treatment, endoscopic studies revealed the elevation of the entire ulcer, which grew into a mass resembling a submucosal tumor associated with a bridging fold. A biopsy of the periphery of the ulcer revealed the presence of Candida albicans in the tissue specimen. Endoscopic ultrasonography revealed a tear in the submucosa and an inflammatory picture that extended into the tunica muscularis. The patient was diagnosed as having a Candida‐infected gastric ulcer. Concomitant use of topical and oral fungizon resulted in the protuberance settling; it was confirmed that the tumor mass completely disappeared and the ulcer healed after 58 days of treatment.

A Small Gastric Cancer in Association with Menetrier Disease

Abstract: We studied a 57‐year‐old man who was diagnosed as having giant rugae at a mass‐screening for gastric cancer. He was examined endoscopically for check‐up purposes. In addition to giant rugal folds which occurred throughout the entire fundus and body of the stomach, a type IIc lesion was noted in the posterior lower wall of the gastric body. A biopsy revealed signet ring cell carcinoma. A total gastrectomy was performed. A resected specimen was serially sectioned and underwent histopathological examination; hypertrophy and cystic elongation of the gastric glands indicative of so‐called giant hypertrophic gastritis was seen. The histological type of the type IIc lesion was undifferentiated adenocarcinoma with the signet ring cells being confined to the mucosal layer. This patient had a rare case of Menetriers disease complicated by intramucosal carcinoma.