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Biomedical subjects

E Yamada

Publications and source records attributed to E Yamada.

At least 163 records · Page 9Linked to original sources
PubMed1983

Semiquantitative histochemical investigation of lysosomal enzyme activities in the aortic endothelial cells of rats with renal hypertension.

To obtain information about changes in lysosomal enzyme activities in the aortic endothelial cells in arterial hypertension, semi-quantitative histochemical investigations of acid phosphatase (Ac-Pase) and N-acetyl-beta-glucosaminidase (NAGase) activities in the aorta of rats with renal hypertension were performed on "Häutchen" monolayer preparations. The aortic endothelial cells in renal hypertensive animals showed increased Ac-Pase and NAGase activities compared with those in control normotensive rats and tended to increase with advancing age. These results, like our previous data from spontaneously hypertensive rats (SHR), indicated that degeneration of endothelial cells, expressed by increased lysosomal enzyme activity, was accelerated by hypertension, and the possible participation of genetic factors in the activation of these enzymes in SHR was ruled out. Increased lysosomal enzyme activity may be involved in the development of other hypertensive vascular changes.

Acetylglucosaminidase↗
PubMed1983

Semiquantitative histochemical investigation of lysosomal enzyme activities in the aortic endothelial cells of spontaneously hypertensive rats.

In order to obtain information about changes in lysosomal enzyme activities in the aortic endothelial cells under hypertensive conditions, semiquantitative histochemical investigations of acid phosphatase (Ac-Pase) and N-acetyl-beta-glucosaminidase (NAGase) activities in the aorta of spontaneously hypertensive rats (SHR) were performed on 'Häutchen' monolayer preparations. The aortic endothelial cells in SHR showed increased Ac-Pase and NAGase activities as compared with those in control normotensive rats, and the activities tended to increase with advancing age. The degenerating process of endothelial cells expressed by lysosomal enzyme activity seems to be accelerated by hypertension. The increased lysosomal enzymes may participate in the further development of hypertensive vascular changes.

Acetylglucosaminidase↗
PubMed1983

The fine structure of lamellated nerve endings found in the rat gingiva.

The fine structure of lamellated nerve endings found in the rat gingiva (Sprague Dowly) was examined by electron microscopy. The lamellar corpuscles are localized in the subepithelial portion of the dermal papillae and are circular or oval in shape. The lamellar cells surrounding the nerve terminals demonstrate several modifications in their configuration due to the variable number of cytoplasmic sheets. All the sheets are characterized by the presence of numerous caveolae, small mitochondria, a few cisterns of rough endoplasmic reticulum, microfilaments and microtubules. Serial sections clearly showed that the nerve terminal is subdivided into two or four branches, each of which terminates at different levels of the corpuscle. The laminae branch several times, ultimately connecting with those of neighboring laminae through desmosomes, and are separated from similar processes by an interlaminar substance. The nerve endings contain many mitochondria, neurotubules and small clear vesicles. Cytoplasmic protrusions extend from the nerve terminal into the clefts between the lamellar cells. Small clear vesicles are found in the basal area of the protrusion. The interlaminar spaces are occupied by an amorphous material though collagenous fibrils are conspicuous in some regions.

Animals↗
PubMed1983

The mosaic pattern of the inner surface of vertebrate retina.

Retinas of various vertebrates (bullfrog, crow, bull, pig and human) were treated with HCl and collagenase for removal of the basement membrane. The exposed basal surface of Müller cells was observed under a scanning electron microscope. In the nerve fiber layer, the Müller cells divide into small basal processes which extend towards the basal surface, where they terminate with a mosaic pattern. This pattern varies somewhat from species to species and from region to region of the retina.

Animals↗
PubMed1983

[Adjuvant immunochemotherapy combined with OK-432 following surgery of stomach cancer].

Postoperative immunochemotherapy with mitomycin C (MMC), 5-fluorouracil (5-FU) and OK-432 was evaluated as adjuvant therapy for curative resection in the cases of gastric cancer. One hundred and twenty-two patients (28 were excluded) were randomly assigned to 3 groups: Group A-MMC and 5-FU (28 cases); Group B-MMC, 5-FU and OK-432 (33 cases); Group C-control (33 cases). There were no differences in the back ground factors influencing survival time among each group. Group B showed better results in survival rate and disease free interval as compared with Group A or C. Minor and reversible side effects such as enterogastric disorder, leukopenia (less than 3000/mm3), thrombo cytopenia (less than 7 X 10(4)/mm3) and elevation of serum transaminase (S-GPT greater than or equal to 100 unit) were equivalently observed in frequency in each Group A and B, but they were milder in Group B than Group A.

Aged↗
PubMed1983

[Case of early malignant lymphoma scattered over the whole stomach].

Early malignant lymphoma is rare and cases with scattering over the whole stomach are extremely rare. Malignant lymphoma is frequently accompanied by R.L.H. or multiple malignant lymphoma. In our case, some lesions were difficult to distinguish from reactive lesions because cellular atypia was of a low grade. As preoperative radiograpic and endoscopic examination had suggested the lesions to be widespread, the surgical stump was carefully inspected to avoid leaving malignant cells. We discuss the surgical treatment of malignant lymphoma of the stomach.

Gastrectomy↗
PubMed1983

[Adenocarcinoma adjoining to the gastric antrum and minute carcinoid--a case report].

The simultaneous occurrence of carcinoma and carcinoid in the stomach is rare. Only 5 cases have been reported in the literature so far. Our patient developed double primary neoplasms adjoining the gastric antrum. One was an early ulcerated adenocarcinoma limited to the submucosa, the other a minute carcinoid also within the submucosa. A large amount of 5-HIAA, but a normal amount of histamine, was excreted in the urine. The carcinoid syndrome, however, was absent through clinical course. The patient died of liver metastasis 3.5 months after gastrectomy. Microscopic examination after autopsy disclosed that the metastases consisted of only carcinoid cells.

Adenocarcinoma↗
PubMed1982

Image analysis of electron micrographs of ATPase (Coupling Factor TF1) from thermophilic bacteria and luminal epithelium of mouse urinary bladder.

Electron micrographs of two dimensional array of H+-ATPase (Coupling Factor TF1 from the thermophilic bacteria) and luminal epithelial protein of urinary bladder were obtained using negative staining method and freeze-fracture method, respectively. Images which showed good optical diffraction pattern were digitized by a computer-linked flat-bed two dimensional microdensitometer and processed digitally. The results of translational computer noise filtering showed that the outline of TF1 molecules looks like a hexagon or an asterisk in the presence of sodium azide which is a specific inhibitor of TF1 or AMPPNP which is an unsplitable analogue of ATP, respectively. The luminal epithelial protein also looks like a hexagon. Rotational harmonic analysis was carried out to examine the rotational symmetry of the filtered images of TF1. It was found that 2-fold or 6-fold symmetry is dominant in the presence of sodium azide or AMPPNP, respectively.

Adenosine Triphosphatases↗
PubMed1981

Localization of tritiated vitamin A in lymph nodes of the mouse: an autoradiographic study of vitamin A-storing cells.

Localization of tritiated vitamin A in lymph nodes of the mouse was investigated by the use of light- and electron-microscopic autoradiography. Young male mice were fed a diet containing 3H-vitamin A acetate for a week. Lymph nodes were removed and prepared for autoradiography. Lipid droplets in fibroblast-like cells showed high concentrations of radioactivity. These cells were distributed around lymphatic sinuses and blood vessels. The cells can, therefore, be classified as "vitamin A-storing cells" according to criteria proposed earlier by Yamada and Hirosawa (1976). Control animals from the same litter were maintained on ordinary laboratory food for the same period and examined by electron microscopy. Lipid-droplet-containing cells were found in the same areas as in the experimental animals but in fewer numbers. This suggests that the increased number of vitamin A-containing lipid droplets is due to hypervitaminosis A in the experimental animals. The presence of some cells containing these droplets in the control animals would imply that even under normal feeding conditions the animals ingested excess amounts of vitamin A, which was retained in lipid droplets. The stored vitamin A probably participates in metabolic processes such as the formation of glycoproteins in ground substance.

Animals↗
PubMed1981

Unusual cytoplasmic bodies in Purkinje cells of the Gunn rats.

The fine structural changes of cerebellar Purkinje cells in Gunn rats were studied with electron microscope to clarify the neurotoxicity of bilirubin. The previous reports including mitochondrial change were confirmed. The new cytologic feature demonstrated in this study was the presence of two different types of unusual membranous cytoplasmic bodies (MCB). One type was the aggregation of rod-like structures which were enveloped in double membranes and contained homogeneous and electron-dense matrix. Another type was the whirled lamellar structure which appeared to be formed of the microtubules and its unit particles. These two different MCB may suggest the different neurotoxicity of bilirubin: the former may result from the accumulation product of bilirubin-lipid complex, the latter may reflect the abnormal process of the microtubular assembly induced by bilirubin.

Animals↗
PubMed1981

Acid phosphatase activity in the aorta of spontaneously hypertensive rats and the effect of various antihypertensive drugs.

In an attempt to obtain information about the arterial lysosomal enzymes in hypertension, we biochemically investigated acid phosphatase (Ac-Pase) activity in the aorta of spontaneously hypertensive rats (SHR) and the effects of various antihypertensive drugs. Ac-Pase activity in SHR was always higher than that in age-matched control rats. The enzyme activity tended to increase progressively with advancing age, a tendency which was more pronounced in SHR than in control rats. The aging process expressed by the Ac-Pase activity seems to be accelerated under hypertensive conditions. Antihypertensive drugs such as reserpine, hydrochlorothiazide, hydralazine and propranolol significantly suppressed the rise of blood pressure and decreased the aortic Ac-Pase activity in SHR. In particular reserpine and propranolol lowered Ac-Pase activity more effectively than it did blood pressure. Hypertension as well as catecholamine seem to be involved in the increase in the aortic lysosomal enzyme activity in SHR.

Acid Phosphatase↗