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Biomedical subjects

Y Nagashima

Publications and source records attributed to Y Nagashima.

At least 235 records · Page 13Linked to original sources

[Familial predisposition to cancer: a cohort study of participants in a cervical cancer screening program].

A numerous number of case-control studies have already demonstrated a certain extent of familial clustering for most human cancers. This is the first report of follow-up study with respect to familial predisposition to cancer. About 40 thousands women who participated in a cervical cancer screening program in 1977 were followed up until 1985 by using the population-based cancer registry. Cancer patients who were detected in the cohort population and their controls were compared for the family history of cancer and female reproductive history both of which had been recorded in a computer file beforehand. For large bowel cancer and breast cancer, positive effect of familial predisposition was observed, though not statistically significant.

Adult↗

Evidence for a role of the plasma kallikrein-kinin system in acute inflammation: reduced exudation during carrageenin- and kaolin-pleurisies in kininogen-deficient rats.

Experimental pleurisy was induced by intrapleural injection of carrageenin or kaolin in three strains of rat: Brown Norway-Katholiek (B/N-Ka), Brown Norway-Kitasato (B/N-Ki) and Sprague-Dawley (SD). B/N-Ka rats (kininogen-deficient) showed significantly less pleural fluid accumulation and exudation rate than SD rats or than B/N-Ki rats (normal). The result indicates the involvement of the plasma kallikrein-kinin system in these pleurisies and a role of high-molecular-weight kininogen is suggested.

Acute Disease↗

Myoepithelial cell ultrastructure in the submandibular gland of man.

In human submandibular glands, two types of myoepithelial cells can be distinguished in serial ultrathin sections. The dark myoepithelial cell type was stellate in shape and exhibited a pronounced electron density due to numerous myofilaments with focal densities. Dark cell types accounted for the greater part (76%) of the myoepithelial cells and furthermore showed adenosine triphosphatase activity. This type of myoepithelial cell is considered to be that previously observed in mammalian salivary glands. Occasionally, desmosomes could be found between the processes of adjacent dark myoepithelial cell types, which is appropriate with respect to the strong compression of acinar or intercalated duct cells. The light myoepithelial cell type was large and ellipsoid with a few short-thick processes, and was characterized by an electron lucent cytoplasm which included scant and unevenly distributed myofilaments. Light cell types showed positive adenosine triphosphatase activity and accounted for only a small part (17%) of the myoepithelial cell number. Transitional forms between these two types were also observed. The light myoepithelial cell type may mature into the dark myoepithelial cell type by means of the transitional form. In addition, clear cells were sometimes encountered between the myoepithelial cell and the acinar or intercalated duct cells.

Aged↗

Effects of purified hog pancreatic kallikrein on the kinin-prostaglandin system and renin-angiotensin-aldosterone system.

In the present study, hog pancreatic kallikrein (HPK, 2,000 KU/kg body weight) was intramuscularly injected into male rabbits and several plasma hormones [kinin, prostaglandin E (PGE), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), thromboxane B2 (TXB2), plasma renin activity (PRA), aldosterone, and ACTH] were measured before and after the HPK administration, in order to clarify the role of glandular kallikrein in the blood. The plasma kinin concentrations were significantly (p less than 0.001) increased from 1 +/- 1 (mean +/- SE), the baseline level, to 230 +/- 22, 288 +/- 36 and 130 +/- 9 pg/ml at 30, 60, and 120 min, respectively, after HPK administration. The plasma level of PGE were slightly increased after HPK administration, but the change was not significant compared to the mean baseline level. The plasma levels of 6-keto-PGF1 alpha were significantly increased from 229 +/- 38, the baseline level, to 594 +/- 131 (p less than 0.05) at 30 min after the administration of HPK and tended to increase (378 +/- 67) at 60 min after the HPK administration, but fell to 278 +/- 37 pg/ml at 120 min after the administration of HPK. On the other hand, the changes in plasma TXB2, aldosterone, ACTH, and PRA before and after HPK administration were not significant. The present results showed that exogenous intramuscular administration of HPK increased the plasma levels of kinin and prostacyclin, but caused no elevation in the plasma levels of other hormones including PRA. It is concluded, therefore, that in this acute experiment, there was a close relationship between the kallikrein-kinin system and prostaglandins.

6-Ketoprostaglandin F1 alpha↗

Scanning electron microscopical observation on the isolated mucosa of rat small intestine: with special reference to the intestinal crypt.

The small intestinal mucosa of rats (male, aged 8 weeks) was isolated by the Bjerknes and Cheng's method (1981): the anesthetized rats were perfused through the left ventricle with a solution of ethylenediaminetetraacetic acid (30 mmol/l) in calcium-magnesium-free Hanks' solution, and then the mucous epithelium was removed from a segment of the duodenum, jejunum and ileum by means of vibration. Three-dimensional images of crypts on the isolated mucosa were obtained by scanning electron microscopy. The length and number of the crypts between the villi were observed to decrease along the intestine from the duodenum to the ileum. The majority of intestinal crypts were simple non-branched tubular glands, however, budding and bifurcation of the crypt ends were often observed. It was relatively rare to find longitudinally split crypts. The shapes of the crypts seems to denote various stages of the proliferation of crypts.

Animals↗

[The effects of hog pancreatic kallikrein on the plasma kinins-prostaglandins and renin-angiotensin-aldosterone systems].

Recently several reports have been presented stating that glandular kallikrein is present in human and animal blood, and that the oral administration of hog pancreatic kallikrein (HPK) normalises decreased urinary kallikrein and prostaglandin E2 (PGE2) excretions and elevated blood pressure in hypertensive patients. In this study, HPK (2,000 KU/kg body weight) was intramuscularly injected into male rabbits, and several hormones (plasma kinins, plasma PGE, plasma 6-keto PGF1 alpha, plasma thromboxane B2 (TXB2), plasma renin activity (PRA), plasma aldosterone, plasma ACTH) were measured before and after HPK administration in order to clarify the role of glandular kallikrein in the blood. Plasma kinins concentrations were significantly increased (the mean baseline level: 1 +/- 1 pg/ml (mean +/- S.E.), 30 min: 230 +/- 22 (p less than 0.001), 60 min: 288 +/- 36 (p less than 0.001), and 120 min: 130 +/- 9 (p less than 0.001] after HPK administration. Plasma levels of PGE were slightly increased after HPK administration, but the change was not significant as compared with the mean baseline level. Plasma levels of 6-keto PGF1 alpha were significantly increased from the mean baseline level of 229 +/- 38 pg/ml to 594 +/- 131 (p less than 0.05) at 30 min and to 378 +/- 67 (p less than 0.01) at 60 min but were decreased to 278 +/- 37 at 120 min after HPK administration. On the other hand, the changes in plasma TXB2, aldosterone and ACTH concentrations, and PRA were not significant before and after HPK administration. From the present study, it was clarified that the exogenous intramuscular administration of HPK increased plasma levels of kinins and PGI2, but induced no elevation in plasma levels of other hormones including PRA. Therefore, it was concluded in this acute experiment that there was a close relationship between the kallikrein-kinin system and PGs.

6-Ketoprostaglandin F1 alpha↗

Separation of tetrodotoxin and paralytic shellfish poisons by high-performance liquid chromatography with a fluorometric detection using o-phthalaldehyde.

Tetrodotoxin (TTX) and a variety of paralytic shellfish poisons (PSPs) were extracted from toxic specimens of puffer and scallop, and quantitated by high-performance liquid chromatography with a fluorometric detection using o-phthalaldehyde. Fluorescence spectra for the TTX- and PSP-fluorophors in 0.05 M borate buffer (pH 10) showed maxima at 453 nm with 332-nm excitation. The fluorescence intensity per nM of TTX was found to be 3 and those of PSP to be 4-12. This fluorometric technique may be useful for the simultaneous quantitation of TTX and PSP in small volumes of toxin extracts.

Animals↗

Structural study on the active site of porcine pepsin and Rhizopus chinensis acid protease. Spin labeling with diazoketone reagents.

To investigate the active site structures of porcine pepsin and Rhizopus chinensis acid protease (RAP), spin label techniques were applied for these enzymes. Comparison of spin labeled porcine pepsin and RAP suggested that the active site cleft of porcine pepsin was narrower at the top, but wider at the bottom than that of RAP. Addition of pepstatin restricted the motion of the labeled nitroxide radicals. Under alkaline conditions, the enzymes changed their conformation discontinuously and irreversibly to open the active site clefts and to lose the binding ability for pepstatin. The denaturation points of both the enzymes were determined to be pH 6.2.

Animals↗