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Biomedical subjects

S Asaki

Publications and source records attributed to S Asaki.

81 records · Page 5Linked to original sources

Cytological diagnosis of leiomyogenic tumors of the stomach.

The cytological findings in 7 cases of leiomyoma and 4 cases of leiomyosarcoma can be summarized as follows: For differential diagnosis of these lesions, in comparison with leiomyoma cells, leiomyosarcoma cells were found to have 1) increased minor axis diameters of the nuclei and nuclear anisokaryosis, 2) dark nuclear staining, 3) enlarged and darkly stained chromocenters, 4) dark staining and thickening of the nuclear rim, 5) enlargement of nuclear clear areas, 6) increased numbers of oval nuclei and greater pleomorphism, 7) an increase in size and number of the nucleoli, 8) a strong tendency for cell atypism, such as anisocytosis and pleomorphism. In the light of these findings, it is believed that differential diagnosis is indeed possible.

Cell Nucleus↗

Early endoscopic features of stomach cancer and its mode of growth.

To establish the earliest sign of stomach cancer in endoscopy and to reveal the subsequent morphologic changes of the lesion, we studied retrospectively 41 cases of stomach cancer. The eariest sign consisted of redness, small polypoid lesions, flat mucosa with slight unevenness and small depressed lesions. There was no clear correlation between the observation period and the size of cancer lesion in cases of early stomach cancer. In cases of advanced cancer, however, the observation period correlated with the size of cancer lesion to a certain extent, and the correlation between the area of cancer (Y cm2) and the observation period (X months) gave a linear equation of Y = 0.68X-3.13.

Aged↗

Observations on benign gastric ulcer simulating gastric carcinoma.

We have re-evaluated over-diagnosed cases which were first diagnosed, pre-operatively, as gastric cancer yet later confirmed as benign lesion (excavated lesion, in particular) in the post-operative histological examination of resected stomachs. We have experienced a total number of 1,358 cases which, being detected through mass survey, were diagnosed as cancer and, consequently, operated upon. On the other hand, 61 benign cases were misdiagnosed as cancer, 28 cases being protruded lesions and 33 cases excavated lesions. Among the misdiagnosed cases of excavated lesions, 27 cases were gastric ulcers or their scars, the remaining 6 cases being gastritis or gastric erosion. In 22 out of 33 cases of misdiagnosis, the wrong diagnosis was made by relying solely upon X-ray and endoscopy. Even after the addition of cytology, there were still 9 cases of misdiagnosis. Since, however, biopsy was introduced, there have been only 2 cases of wrong diagnosis. We may safely say that through these findings the absolute necessity of biopsy for the attainment of an accurate diagnosis of early gastric cancer has been sufficiently attested.

Biopsy↗

Lipid-chemical features of human gastric cancerous, polypous and ulcerative tissues.

Fourteen cases of gastric cancer, 9 cases of gastric polyp and 4 cases of gastric ulcer were studied on their tissues lipid-chemically with the aim to clarify the biochemical differences between malignant and benign growth of the human gastric tissue. Tissues were collected by surgical operation or a biopsy together with the normal tissues surrounding the lesions. One part of each tissue was subjected to histologic examination and the other part to lipid analyses by means of TLC and GLC. The total lipid content was dcreased in 71% of gastric cancerous cases and in 75% of both cases of gastric polyp and gastric ulcer as compared with the respective control tissues. The phospholipid fatty acid content of the lesions was decreased in 83% of cancerous cases but in 50% of polypous cases as compared with the respective control tissues. As for the phospholipid fatty acid composition, the percentage value of C20:4 was increased and the percentage value of C18:2 was decreased in gastric cancerous tissues when compared with those of gastric polypous tissues. Such a change of the phospholipid fatty acid composition may produce the change of the fluidity of the cell membrane and may provoke a malignant growth of human gastric cancer cells.

Fatty Acids↗

Endoscopical polypectomy of the gastric polyp with electro-coagulation wire loop.

A forward-viewing fiberscope equipped with two channels was designed for safer and easier gastric polypectomy under endoscopic control using electro-surgical technique. No electrical accident, bleeding, perforation or significant complications were noticed. Mucosal ulcerations at the polypectomy site healed within a month leaving minor scars behind. In 30 cases, U1 II gastric ulcers developed after polypectomy, which healed leaving convergence of mucosal folds behind. Fiberscopic excision of gastric polyps was also useful for establishing a reliable diagnosis of gastric polyp cancer which is sometimes overlooked by routine biopsy procedure. It may be the "perfect biopsy". The patient with gastric polyp who is aware of his own illness and feels uneasy can be released from his anxiety and regain both physical and mental health at the cost of minimal risks of endoscopic polypectomy.

Electrocoagulation↗

Endoscopic treatment of bleeding peptic ulcers.

Since June, 1979, patients with upper gastrointestinal bleeding, other than of the varices, have been subjected to the procedure of endoscopic hemostasis with injection of absolute ethanol. This method is based on the principle of tissue dehydration and fixation with absolute ethanol. In this procedure, the bleeding vessels are dehydrated and fixed with consequent vasoconstriction and necrosis of the vascular wall, including its endothelial lining, thereby facilitating thrombogenesis and hemostasis. We have applied this method in 147 cases of upper gastrointestinal bleeding, obtaining a successful temporary hemostasis in all cases. Rebleeding from the same site occurred in 5 cases and new bleeding from another site occurred in 6 cases; however, in these cases, hemostasis was successfully obtained by reinjecting ethanol. After hemostasis, 6 patients received elective surgery and another 2 were operated on due to perforation of the stomach. Of the patients treated by this method, 11 died due to causes unrelated to gastrointestinal bleeding. After the hemostatic procedure, cure of the ulcer by conservative treatment was attained in the remaining 136 cases. Therefore, the local injection of absolute ethanol is an effective hemostatic method for upper gastrointestinal bleeding.

Adolescent↗

Analysis of p53 abnormalities in endoscopic gastric biopsies.

We performed immunohistochemical staining for p53 in 152 endoscopic gastric biopsy specimens, including 39 adenomas, 80 carcinomas, and 33 cases of regenerative atypia. Direct DNA sequencing of exons 5,7 and 8 of the p53 gene was performed on 8 specimens. Nuclear p53 immunoreactivity was observed in 36 of 80 carcinomas, 7 of 39 adenomas and none of the cases of regenerative atypia. Three of the adenomas demonstrated diffuse or focal p53 immunoreactivity. All three cases were associated with severe degrees of epithelial dysplasia, and two of them harbored carcinoma on subsequent polypectomy. Among 6 p53 positive carcinomas and adenomas sequenced, 3 showed DNA mutations, all G:C to A:T transitions. These results indicate that positive p53 immunoreactivity in intraepithelial atypical cells on gastric biopsies represents true dysplasia or carcinoma rather than regenerative atypia.

Adenocarcinoma↗

Immunohistochemistry of Caspase3/CPP32 in human stomach and its correlation with cell proliferation and apoptosis.

Caspase3/CPP32 is a member of the interleukin-1 beta-converting enzyme (ICE) or cell death effector (CED)-3 family, which is involved in the induction of apoptosis and has been considered to be correlated with apoptosis because of the most downstream enzyme in their apoptosis inducing pathway. We immunolocalized Caspase3/CPP32 in both normal and neoplastic human gastric mucosa. We then correlated the findings with cell proliferation studied by Ki67 immunostaining and apoptosis, which was tested for by DNA fragmentation in situ using TdT-mediated dUTP biotin nick end labeling (TUNEL) method in order to examine possible biological significance in cell turnover of normal and pathological human gastric tissues. Caspase3/CPP32 immunoreactivity was detected in both the cytoplasm and nuclei of glandular epithelial cells, predominantly in the Ki67 positive proliferative zone and TUNEL positive foveolar epithelium of normal non-neoplastic gastric mucosa (n = 10) and tumor cells of both adenoma (n = 17) and carcinoma (n = 33). We determined the labeling index (LI) of Ki67, Caspase3/CPP32 and TUNEL positive cells by evaluating the number of positive cells in the same areas of serial tissue sections using computer-assisted image analysis. Ki67 LI in adenocarcinoma (78.6 +/- 12.6%) was significantly [p < 0.0001] higher than that of adenoma (43.8 +/- 8.9%) and non-neoplastic gastric mucosa (24.2 +/- 9.0%). Caspase3/CPP32 LI in adenocarcinoma (17.1 +/- 10.3%) was significantly lower [p < 0.0001] than that of gastric adenoma (33.1 +/- 19.8%) and non-neoplastic gastric mucosa (42.4 +/- 15.8%). TUNEL LI in adenocarcinoma (1.9 +/- 2.1%) was significantly [p < 0.0001] lower than that of non-neoplastic gastric mucosa (6.0 +/- 3.5%), but not significantly different from that of adenoma (3.0 +/- 2.9%). These results indicate that gastric adenocarcinoma is associated with an inhibition of apoptosis and the augmentation of proliferative activity of tumor cells compared to non-neoplastic gastric mucosa. There was a tendency to a positive correlation between the Caspase3/CPP32 and TUNEL LI and an inverse correlation between the Caspase3/CPP32 and Ki67 LI, when evaluating all the specimens, although the correlation did not reach statistical significance. These results also suggest that Caspase3/CPP32 is involved in the development or regulation of apoptotic cell death in cell turnover of normal and neoplastic mucosa of the human stomach.

Adenocarcinoma↗