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Biomedical subjects

Y Osamura

Publications and source records attributed to Y Osamura.

At least 91 records · Page 5Linked to original sources
PubMed1985

Ultrastructural studies in 4-aminopyrazolopyrimidine (4-APP)-induced fatty liver.

Ultrastructural alterations of 4-aminopyrazolopyrimidine (4-APP)-induced fatty liver were studied. Light microscopically, liver sections after 3 to 5 days of 4-APP administration demonstrated more extensive fatty changes and highly osmiophilic lipid droplets were mainly observed in the portal zones of the lobules. The most striking ultrastructural alterations were seen in the Golgi complexes and rough endoplasmic reticulum. Golgi complexes were markedly dilated and osmiophilic vesicles were noted near the Golgi complexes. In the rough endoplasmic reticulum, dilatation of cisternae, loss of the parallel arrangement and dilated vesicles, most of which contained diminished numbers of ribosomes, were also seen. In addition, degranulation of rough endoplasmic reticulum was observed. However, no remarkable changes were noted in the mitochondria. Based on these findings, the functional state of the organellae concerned was discussed.

Adenine↗
PubMed1984

Ultrastructural changes in rat adrenocortical cells produced by a 4-aminopyrazolopyrimidine (4-APP) dosage.

The relation between adrenal cholesterol synthesis and ultrastructural changes was studied in rat adrenal glands stimulated by 4-aminopyrazolopyrimidine (4-APP). Ultrastructural observations were focused on the inner fasciculata-reticularis (Zone I) and the outer fasciculata (Zone O) of the adrenal glands. Zone I in 4-APP-treated rat adrenals had increased tubules and vesicles in the smooth endoplasmic reticulum, mitochondrial enlargement and the accumulated osmiophilic lipid droplets. In contrast, Zone O of the 4-APP-treated rat adrenals showed a decrease in osmiophilic lipid droplets and no increase in any of the elements of the smooth endoplasmic reticulum. These results are strong evidence that under 4-APP treatment cholesterol synthesis takes place in the increased smooth endoplasmic reticulum in Zone I cells. The functional status of the cells of the inner and outer zones of the adrenal cortex also is discussed.

Adenine↗
PubMed1984

Observations on the timing of operative intervention for aortic regurgitation.

We examined the application and timing of valve replacement in 105 cases of aortic regurgitation, from the aspect of etiology, clinical findings and prognosis. The mortality for patients after aortic valve replacement was 12.9%. This was lower than that for the patients not operated up on, which was 35.0%. The mortality after valve replacement for patients having acute aortic regurgitation due to active endocarditis was as high as 80%, which showed the limitations of medical and surgical therapy. In cases of chronic aortic regurgitation, if valve replacement is performed within 3 years of the appearance of heart failure symptoms, the mortality is 0. Even after three years, valve replacement is applicable if there are no ventricular premature contractions. CTR 65%, %FS 21%, R/Th 2.9 and EF 38% were considered to be the critical factors for postoperative prognosis.

Adult↗
PubMed1984

Rhabdomyosarcoma of the prostate--report of a case with an immunohistochemical study of the neoplastic rhabdomyoblast.

A case of rhabdomyosarcoma of the embryonal alveolar type arising from the prostate in a 6-year-old boy was reported with a immunohistochemical survey. Tumor cells in the biopsied inguinal lymph node were weakly positive for myoglobin and CPK-mm and showed positive staining for neuron specific enolase (NSE). At autopsy, an immunohistochemical examination demonstrated that the tumor cells, especially differentiated elongated cells, were strongly positive for myoglobin, CPK-mm and NSE. An enzyme immunoassay for three distinct subunits of NSE revealed a 320 fold increase in the beta subunit of enolase which is specific for heart and skeletal muscle. The diagnostic significance of immunohistochemical methods for rhabdomyoblasts was discussed.

Child↗
PubMed1984

Distribution of filipin-sterol complexes in rat hepatocytes.

Distribution of cholesterol in rat hepatocytes under normal untreated and phenobarbital-treated conditions was studied by freeze-fracturing using filipin. In untreated rat hepatocytes, filipin-sterol complexes were observed on intercellular plasma membranes as well as on lysosomes and microbodies. These complexes were evenly distributed. In phenobarbital-treated rat hepatocytes, filipin-sterol complexes in the lysosomes or microbodies were distributed unevenly. In the bile canaliculi, no filipin-sterol complexes were noted. Based on these findings, the functional state of the organellae concerned was discussed.

Alkaline Phosphatase↗
PubMed1984

Enzyme histochemical and ultrastructural studies in human adrenal glands of normal and anencephalic fetuses.

In order to confirm the functional status of adrenal gland in human anencephalic fetuses, an enzyme histochemical and ultrastructural approach was used to study the adrenocortical cells of normal and anencephalic human fetuses. In the adrenal gland of the anencephalic fetuses (32nd, 34th and 36th week of gestation), enzyme histochemical activities of alkaline phosphatase and acid phosphatase was weaker than those in normal human fetuses (20th and 26th week of gestation). Ultrastructurally, a large number of lipid droplets, rough endoplasmic reticulum, tubular or vesicular profiles of smooth endoplasmic reticulum and mitochondria with poorly developed cristae were noted in the cytoplasm. In addition, Golgi complexes and microvilli were very poorly developed. Based on these findings, functional aspects of the adrenal gland in anencephalic fetuses were discussed.

Acid Phosphatase↗
PubMed1984

Histochemical studies of metaplastic lesions in the human gallbladder.

We studied goblet cell metaplasia and pseudopyloric gland metaplasia in 25 surgically removed, paraffin-embedded gallbladder specimens using mucin histochemistry, silver methods for endocrine cells, and the indirect immunoperoxidase method for 12 peptide hormones, secretory component, and lysozyme. Goblet cell metaplasia was closely related to the occurrence of endocrine cells that showed argentaffinity, argyrophilia, or immunoreactive gastrin, somatostatin, pancreatic polypeptide, or motilin. Mucosal areas without goblet cell metaplasia were devoid of such endocrine cells. Metaplastic pseudopyloric glands showing lysozyme immunoreactivity were positive for class III mucin with paradoxical concanavalin A staining. Specimens with florid metaplastic lesions revealed a low tendency to form Rokitansky-Aschoff sinuses whose cells never showed a metaplastic nature. We compared the pathophysiological significance of metaplastic lesions in the gallbladder with intestinal metaplasia of the stomach.

Endocrine Glands↗
PubMed1983

Enzyme histo-cytochemical studies in human adrenocortical adenomas. [II] Cushing's syndrome.

Enzyme histo-cytochemical staining was performed for 3 beta-hydroxysteroid dehydrogenase, alkaline phosphatase and acid phosphatase in the compact and clear cells of the adrenocortical adenomas associated with Cushing's syndrome (Cushing's adenomas). In the compact cells, enzymatic activities of 3 beta-hydroxysteroid dehydrogenase and alkaline phosphatase were stronger than those in the clear cells. Electron microscopic localization of alkaline phosphatase was mostly present on well developed microvilli, while, acid phosphatase was observed in lysosomes near the well developed smooth endoplasmic reticula. On the other hand, in the clear cells, cytochemical localization of alkaline phosphatase was mainly present on the intercellular plasma membrane, while acid phosphatase was mostly observed near the lipid droplets. Based on these data, functional aspects of the compact and clear cells in Cushing's adenomas are discussed.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Enzyme histo-cytochemical studies in human fetal adrenal glands.

Enzyme histo-cytochemical staining including alkaline phosphatase, acid phosphatase and 3 beta ol dehydrogenase in human fetal adrenal glands (13 to 20 week fetuses) was studied. Enzyme histo-chemical activity of alkaline phosphatase was mainly observed in cell membranes of the fetal cortex. The permanent cortex showed weak or negative activity. Histochemical staining of acid phosphatase was mostly observed in the cytoplasm as large globular structures near the nucleus in the fetal cortex, and intracellular localization of acid phosphatase by electron microscopic enzyme cytochemistry was mainly observed in lysosomes including dense bodies of the fetal cortex. The permanent cortex was only slightly stained for acid phosphatase. The activity of 3 beta ol dehydrogenase was predominantly observed in the cytoplasm of the fetal cortex in the 20 week fetus. Based on these findings, the significance of these enzymes in the fetal cortex is discussed.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Enzyme histocytochemical studies in human adrenocortical adenomas. [I]. Primary aldosteronism.

Enzyme histocytochemical staining including alkaline phosphatase, acid phosphatase, 3 beta hydroxysteroid dehydrogenase and 11 beta hydroxysteroid dehydrogenase was studied in human adrenocortical adenomas associated with primary aldosteronism. Histochemically, these enzyme activities were weaker in clear cell type adenomas than in the normal human adrenal cortex. While compact cell type adenomas showed stronger enzyme activities than the clear cell type adenomas. Electron microscopic localization of alkaline phosphatase was mainly observed in plasma membrane at the intercellular sites. Occasionally, this enzyme activity was also observed in the mitochondrial outer membrane, mainly in compact cells. The significance of these enzymes in the adenoma cells is discussed.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Leiomyoma of the lung--report of a case.

A case of leiomyoma of the lung appearing in a 28-year-old female with a history of supracervical hysterectomy for uterine leiomyoma 10 years previously is reported. She had no symptoms but chest X-ray film showed a single nodule in the right upper lobe which slowly increased in size over a 3 year interval. At thoracotomy the tumor measured 4 cm in size and was sharply demarcated from the lung parenchyma without any connection with the bronchial tree. Histological findings proved this tumor to be a leiomyoma with no atypical cells or mitoses showing a close resemblance to uterine leiomyoma. Metastasizing uterine leiomyoma is very rare. Because these leiomyomas behave clinically as a low grade malignancy despite a histologically benign appearance, careful long term follow-up is necessary.

Adult↗