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Biomedical subjects

Y Katsukura

Publications and source records attributed to Y Katsukura.

9 recordsLinked to original sources
PubMed1993

Interaction of GTP-binding protein Gq with photoactivated rhodopsin in the photoreceptor membranes of crayfish.

Interaction of G-protein with photoactivated rhodopsin (Rh*) in crayfish photoreceptor membranes was investigated by immunoprecipitation using an antibody against rhodopsin. Two kinds of protein were co-precipitated with rhodopsin. One is an alpha subunit of class-q G-protein (42 kDa, CGq alpha) which showed light-induced, dose-dependent binding to rhodopsin, and the other is an actin-like protein (44 kDa) with light-independent binding. Most of the CGq alpha was available for binding to Rh* but was dissociated from Rh* in the presence of GTP gamma S. These findings demonstrate that, in the crayfish photoreceptor, a Gq class of G-protein is activated by Rh*.

Amino Acid Sequence↗
PubMed1989

Effect of Streptococcus lactis preparation in diet of mice on inhibiting age-dependent loss of superoxide dismutase activity in tissues.

SL-diet was prepared using commercial pellets supplemented with 1% pulverized Streptococcus lactis (SL). SL fed group of ICR strain mice were bred from 8 weeks up to 75 weeks. End-point age for survival in these mice was approximately 75 weeks. No significant differences in survival rate were observed at 75 weeks between the commercial diet and SL-diet group. The superoxide dismutase (SOD) activities in the liver, brain and erythrocytes of 75-week-old mice significantly decreased compared with those aged 10 weeks. Cu.Zn-SOD and Mn-SOD activities in the liver and brain of SL-diet mice were maintained in similar degree in the juvenile group, however, decreased significantly in the commercial diet group. SOD in erythrocytes was slightly decreased and no significant difference was noted in either group.

Aging↗
PubMed1985

Distribution pattern of liver matrix proteins, fibronectin and type I collagen, in DAB-induced hepatoma of rat.

Specific antibodies to fibronectin and type I collagen in rat livers were used to demonstrate these matrix proteins with direct immunoperoxidase method in paraffin sections of normal liver, DAB-induced hepatoma and CCl4-induced fibrotic liver. In normal livers, the immunoreactive products of both matrix proteins were found in the periportal regions, while the hepatocytes and most of the interstitial matrix remained unstained. The specimens obtained from DAB-treated liver showed a more intense reaction with fibronectin antibody in the perisinusoidal space including proliferated cholangiolar cells, as compared to no reaction with type I collagen antibody. In CCl4-fibrotic liver, apparent reactions were also found for both matrix proteins in the periportal interstitium and in progressing fibrotic area with severe fatty metamorphosis. These findings suggest that these matrix proteins have an advantage in the attempt to distinguish different patterns of neoplastic alteration in experimental rat livers.

Animals↗
PubMed1983

Inhibition of aging changes by lyophilized Streptococcus faecalis in diet.

Effects of dietary Streptococcus faecalis (SF) on aging were evaluated using 1-week, 6-month, and 27-month-old Wistar and SHR rats. SF was lyophilized and added to commercial pellets at 1%. SF inhibited hypertension in aging SHR. SF inhibited aging-related changes in a wide variety of tissues. These changes were a disarray of hepatic cords, portal fibrosis; calcification of cartilage matrix, dominance of chondroitin sulfate B, and keratosulfate over chondroitin sulfates A and C; aortic endothelial damage, segmental thickening, calcification, and chondroid cells in the intima; atrophy of epidermis and appendages, and increase in amorphous dermal matrix; waxy degeneration and atrophy of psoas muscles; increase in lipoperoxides in the serum, liver, and brain; and reduction of cyclic AMP and GMP in the serum. Histological changes of the xyphoid cartilage, aorta, mesenteric artery, liver, dorsal skin, and psoas muscles in 27-month-old SF rats were much less severe than those in controls.

Aging↗
PubMed1978

Roentgeno-histological studies on serial alveolography.

Using the lung obtained from a 22-year-old female at autopsy, roentgeno-histological studies were carried out on serial alveolography. The pulmonary lymphatics were shown to play an important role in the wash-out of the contrast media. The contrast media injected into the alveolus was gradually transferred on and into the alveolar wall and finally entered the subpleural space. Inflow of the contrast media was further noted into the portion probably representing the "juxta-alveolar lymphatic capillary" according to Lauweryns. Since local edema occurs artificially in serial alveolography, the functional aspects of fluid clearance may also be studied simultaneously unlike the conventional alveolography with its emphasis on morphological diagnosis.

Adult↗
PubMed1977

Serial alveolography-preliminary report.

Serial alveolography using a contrast medium for indirect lymphography was developed at our department. With this technique radiograms comparable to so-called barium-imbibed preparations of resected lung are possible. Furthermore, the procedure has the advantage of demonstrating serial radiographic changes as well as the local contrast medium wash-out or clearance, a local functional aspect of the lung, successively in a very short time. It is practical to accomplish simultaneous examinations in both morphological and functional (most probably concerned with the local pulmonary lymph) aspects with the new procedure. Significant differences in radiographic features have been demonstrated between the normal lung and chronic pulmonary emphysema or fibrotic pulmonary diseases.

Adult↗