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Biomedical subjects

S Hatanaka

Publications and source records attributed to S Hatanaka.

8 recordsLinked to original sources
PubMed1992

Effects of nefiracetam, DM-9384 on amnesia and decrease in choline acetyltransferase activity induced by cycloheximide.

The effects of nefiracetam, [N-(2,6-dimethyl-phenyl)-2-(2-oxo-pyrrolidinyl)acetamide, DM-9384], a cyclic derivative of GABA, were investigated in the cycloheximide (CXM)-induced amnesia animal model using the passive avoidance task. Pre-training administration of DM-9384 attenuated the CXM-induced amnesia as indicated by prolongation of step-down latency. It protected against CXM-induced inhibition of choline acetyltransferase activity in the cerebral cortex. These results suggest that DM-9384 attenuates CXM-induced amnesia by interacting with AChergic neuronal system and enhancing protein synthesis in the brain.

Amnesia↗
PubMed1992

Signet ring cells in breast carcinoma. An immunohistochemical and ultrastructural study.

Two cases of breast carcinoma composed predominantly of neoplastic cells with a signet ring appearance, one a case of invasive lobular carcinoma (ILC) and the other a case of invasive ductal carcinoma (IDC), were examined electron microscopically and immunohistochemically. In signet ring cells in the ILC, mucin was demonstrated ultrastructurally in the intracytoplasmic lumina and also to a small degree in the cytoplasmic mucous granules, whereas in signet ring cells in the IDC, mucin was found only in the cytoplasmic mucous granules. Immunohistochemically, signet ring cells in the ILC were intensely positive for gross cystic disease fluid protein (GCDFP-15), but those in the IDC showed no immunoreaction for GCDFP-15. Thus ultrastructural features and GCDFP-15 immunoreactivity appear to be useful for distinguishing between the two different types of signet ring cells.

Adenocarcinoma, Mucinous↗
PubMed1991

von Recklinghausen's disease associated with somatostatin-rich duodenal carcinoid (somatostatinoma), medullary thyroid carcinoma and diffuse adrenal medullary hyperplasia.

This report describes the concomitant occurrence of a somatostatin-rich duodenal carcinoid, a medullary thyroid carcinoma and a diffuse adrenal medullary hyperplasia in a patient with von Recklinghausen's disease. A 50-year-old Japanese man died from lung metastasis of a malignant schwannoma. In addition to extensive viscero-cutaneous neurofibromatosis, two different types of neuroendocrine tumors were found in the duodenum and thyroid gland at autopsy. The duodenal tumor, which was located in the second portion, showed the histologic appearance of a carcinoid tumor with glandular differentiation and psammoma-bodies. Immunohistochemically the tumor cells were intensely positive for somatostatin. The thyroid tumor was composed of nests of tumor cells arranged in an endocrine pattern, and showed immunoreactivity for calcitonin. A review of the literature revealed no previously reported case of concomitant occurrence of duodenal somatostatinoma and medullary thyroid carcinoma in a single patient with von Recklinghausen's disease. Morphometric analysis of adrenal glands disclosed the presence of diffuse medullary hyperplasia. Thus, the present case exhibited a similarity in some respects with multiple endocrine neoplasia (MEN) syndrome, Type IIa or IIb.

Adrenal Gland Diseases↗
PubMed1991

Apocrine adenocarcinoma of the bilateral axillae.

A case of apocrine adenocarcinoma arising in the bilateral axillae is reported. The patient was an 88-year-old Japanese male who complained of a mass lesion and pus-like discharge in the right axilla. Another mass was also noticed in the left axilla. No other neoplastic lesion was found in other sites of the body. The histologic appearances of the bilateral axillary tumors were almost identical. Both were adenocarcinoma with varying degrees of differentiation, composed of glands and nests of atypical epithelial cells with abundant eosinophilic cytoplasm. Some neoplastic cells exhibited cytoplasmic projections on their apical surface. Foci of in situ carcinoma were observed within the neoplastic tissue in the bilateral axillae. The neoplastic cells were immunohistochemically positive for epithelial membrane antigen (EMA) and gross cystic disease fluid protein (GCDFP-15), but negative for carcinoembryonic antigen (CEA). On the basis of their histologic and immunohistochemical features and distinctive location, the tumors were diagnosed as apocrine adenocarcinoma.

Adenocarcinoma↗
PubMed1991

Effects of DM-9384, a cyclic derivative of GABA, on amnesia and decreases in GABAA and muscarinic receptors induced by cycloheximide.

The effects of N-(2,6-dimethyl-phenyl)-2-(2-oxo-1-pyrrolidinyl)-acetamide [DM-9384], a cyclic derivative of GABA, were investigated in the cycloheximide (CXM)-induced amnesia animal model using the passive avoidance task. Pre- and post-training and pre-retention test administration of DM-9384 attenuated the CXM-induced amnesia as indicated by prolongation of step-down latency. Aniracetam, another cyclic derivative of GABA, also showed antiamnesic effects. Scopolamine, a muscarinic ACh receptor antagonist, and the GABA antagonists, picrotoxin and bicuculline, all antagonized the antiamnesic effects of DM-9384. CXM decreased the number of GABAA and muscarinic ACh receptor binding sites. DM-9384 not only inhibited this effect but actually increased the latter. These results suggest that DM-9384 attenuates CXM-induced amnesia by interacting with GA-BAergic and AChergic neuronal systems and enhancing protein synthesis in the brain.

Amnesia↗
PubMed1991

Paraganglioma of the cauda equina. A case report and review of the literature.

A case of paraganglioma of the cauda equina is reported. The patient was a 55-year-old Japanese woman who complained of lower back pain and gradual weakening of the left lower extremity, she was diagnosed as having a spinal cord tumor, and the tumor was removed surgically. Histologically, the tumor was encapsulated, and consisted of solid nests of large, polyhedral epithelioid cells with abundant eosinophilic cytoplasm. The nests were separated from each other by a thin fibrovascular stroma. Grimelius staining revealed neurosecretory granules in the cytoplasm of the tumor cells. This was further confirmed by electron microscopic observation. The tumor cells were immunohistochemically positive for neuron-specific enolase (NSE), but negative for glial fibrillary acidic protein (GFAP). On the basis of the histologic, immunohistochemical and electron microscopic features of the tumor cells, the tumor was diagnosed as paraganglioma. The cauda equina is a rare location for this type of tumor, and only a limited number of cases have been reported.

Cauda Equina↗
PubMed1990

Protective effect of DM-9384, a novel pyrrolidone derivative, against experimental cerebral anoxia.

The protective effects of DM-9384 [N-(2,6-dimethylphenyl)-2-(2-oxo- 1-pyrrolidinyl) acetamide] against cerebral anoxia were investigated using various animal models. Oral administration of DM-9384 resulted in a significant prolongation of survival time in mice and rats subjected to the normobaric hypoxia; its minimal effective doses were 30 and 10 mg/kg, respectively. A significant protection by this drug against hypobaric hypoxia, histotoxic anoxia and cerebral ischemia also occurred in mice at a dose of 100 mg/kg, p.o. Bifemelane (100-300 mg/kg, p.o.) was protective against these models except for hypobaric hypoxia, and the effects of piracetam, aniracetam and pramiracetam (1000 mg/kg, p.o.) were variable depending on the type of anoxia model used. DM-9384 (100 mg/kg and lower) attenuated the hypolocomotion and the disturbance of cerebral energy metabolism such as a decrease in ATP, an increase in lactate and lactate/pyruvate ratio induced by hypoxia in rats. The spontaneous motor activity, uptake and utilization of brain glucose in normal animals, however, were not influenced by this drug. Based on these results, DM-9384 is characterized as a broad spectrum anti-anoxic drug with negligible CNS depression, and the cerebral protective effect of this drug may be, at least in part, attributable to its ability to improve the cerebral energy metabolic disturbance.

Animals↗