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Biomedical subjects

M Kurata

Publications and source records attributed to M Kurata.

At least 91 records · Page 5Linked to original sources

A possible mechanism for the changes in hepatic and intestinal alkaline phosphatase activities in bile-duct-ligated rats or guinea pigs.

The effects of bile-duct ligation on hepatic and intestinal (jejunum) alkaline phosphatase activities were studied using rats and guinea pigs. In ligated rats, the enzyme activity was increased 4.1-fold in the liver after 24 h and 2.8-fold in the intestine after 12 h. In guinea pigs, the hepatic and intestinal enzyme activities were increased 2.3-fold and 1.5-fold after 100 and 24 h, respectively. The intestinal activity was induced sooner after ligation than hepatic activity. The induction of alkaline phosphatase was inhibited by prior treatment of animals with amanitin, an inhibitor of RNA polymerase activity. This result indicates that the induction is associated with de novo enzyme synthesis. The content of cyclic AMP in liver and intestine increased immediately after ligation. The increase in alkaline phosphatase activities was also inhibited by pretreatment with chlorpromazine, an inhibitor of adenylate cyclase activity. Hence, cellular cyclic AMP may be implicated in playing a role in the induction of alkaline phosphatase by bile-duct ligation.

Alkaline Phosphatase↗

Relationship between luminous fish and symbiosis. I. Comparative studies of lipopolysaccharides isolated from symbiotic luminous bacteria of the luminous marine fish, Physiculus japonicus.

In order to investigate the relationship between host and symbiosis in the luminous marine fish, Physiculus japonicus, the bacterial lipopolysaccharides (LPS) of symbiotic luminous bacteria were compared serologically and electrophoretically. Five symbiotic luminous bacteria (PJ strains) were separately isolated from five individuals of this fish species caught at three points, off the coasts of Chiba, Nakaminato, and Oharai. LPS preparations were made from these bacteria by Westphal's phenol-water method and highly purified by repeated ultracentrifugation. These LPSs contained little or no 2-keto-3-deoxyoctonate and had powerful mitogenic activity. In sodium dodecylsulfate polyacrylamide gel electrophoresis, these PJ-1 to -5 LPSs were separated by their electrophoretic patterns into three groups; the first group included PJ-1 and PJ-4, the second group PJ-2 and PJ-3, and the third group PJ-5 alone. The results agreed with those of the double immunodiffusion test; precipitin lines completely coalesced within each group but not with other groups. In immunoelectrophoresis, one precipitin line was observed between anti PJ-2 LPS serum and PJ-5 LPS but the electrophoretic mobility of PJ-5 LPS was clearly different from that of the PJ-2 LPS group. Furthermore, in a 50% inhibition test with PJ-2 LPS by the passive hemolysis system, the doses of PJ-2 LPS, PJ-3 LPS, and PJ-5 LPS required for 50% inhibition (ID50) in this system were 0.25, 0.25, and 21.6 micrograms/ml for each alkali-treated LPS, respectively, and the ID50's of both PJ-1 LPS and PJ-4 LPS were above 1,000 micrograms/ml. These results indicate that PJ-5 LPS has an antigenic determinant partially in common with LPS from the PJ-2 group but not with LPS from the PJ-1 group and that the symbiotic luminous bacterium PJ-5 is more closely related to the PJ-2 group than to the PJ-1 group. These results show that the species Physiculus japonicus is symbiotically associated with at least three immunologically different strains of luminous marine bacteria in its specialized light organ.

Animals↗

Chemical and biological properties of Lipopolysaccharides from symbiotic luminous bacteria from several luminous marine animals.

The chemical and biological properties of lipopolysaccharides (LPS) in five strains of symbiotic luminous bacteria isolated from four species of luminous marine fishes, Coelorhynchus kishinouyei (CK-1), Chlorophthalmus albatrossis (CA-1), Ventrifossa garmani (VG-1), and Acropoma japonicum (AJ-1b), as well as from a luminous squid, Doryteuthis kensaki (DK-1) were examined. The LPS isolated from these symbiotic luminous bacteria were characterized by the absence of 2-keto-3-deoxyoctonate, known to be a basic component of the usual gram-negative bacterial LPS. All LPS from these symbiotic luminous bacteria upon electrophoresis in sodium dodecylsulfate polyacrylamide gel exhibited one or two clear main bands with high mobility, and one or two obscure minor bands with low mobility when stained with periodate-Schiff reagent. LPS from CA-1 and VG-1 exhibited similar electrophoretic patterns, whereas the electrophoretic patterns of the LPS from CK-1, AJ-1b, and DK-1 were easily distinguishable from each other. All these LPS also had similarly potent and diverse biological activities in regard to their adjuvanticity, immunosuppression, polyclonal effect, B-cell mitogenicity, and activation of the phagocytic function of macrophages.

Adjuvants, Immunologic↗

Buckling of the distal innominate artery simulating a nodular lung mass.

A 68-year-old woman with long-standing hypertension was referred to us. Her plain roentgenogram and tomogram of the chest revealed a nodular mass seen within the right apical lung field. Angiography and computed tomography revealed that this mass, possibly simulating an intrapulmonary mass lesion, was actually due to arteriosclerotic buckling of the distal segment of the innominate artery. This made a posterior-downward protrusion into the lung from the soft tissue above the right lung apex.

Aged↗

Sensitivity to the weed killer DNA-nitralin and cross-sensitivity to dinitrochlorobenzene.

A man, with a dermatitis acquired while working in a factory producing a weed killer, showed sensitivity to 4-methylsulfonyl 2,6-dinitro-N,N-dipropylaniline (DNA-nitralin) and its precursor, 4-chloro 3,-5-dinitrophenylmethyl sulfone (DNC), and cross-sensitivity to dinitrochlorobenzene (DNCB). Sensitization capacities of DNA-nitralin and DNC compared with DNCB, and cross-sensitizations among 11 dinitrobenzene derivatives, including DNA-nitralin, DNC, and DNCB, were studied in guinea pigs. We found that the order of potency was DNCB, DNC, and DNA-nitralin for the sensitization capacity, and that cross-sensitizations may occur among DNCB, DNC, DNA-nitralin, and dinitrofluorobenzene, in comparatively high incidence.

Aniline Compounds↗

Release of 6-keto-prostaglandin F1 alpha and thromboxane B2 from mouse peritoneal macrophages during their adhesion and spreading on a glass surface.

The release of 6-keto-prostaglandin F1 alpha (6KF1 alpha) and of thromboxane B2 (TXB2) from cells were investigated using mouse peritoneal exudate cells (PECs) and non-cultured peritoneal macrophages. They were prepared by adhesion to glass dishes and incubated for 1 hr at 37 degrees C in 5% CO2 in air. Both the percentage of spreading macrophages and the release of 6KF1 alpha and TXB2 increased in proportion to the incubation time. 6KF1 alpha and TXB2 were released from the macrophages, not from the non-coated glass dishes, the spreading of macrophages was hardly detected and lower amounts of 6KF1 alpha and TXB2 were released from these cells compared with cells incubated in non-treated glass dishes. These findings suggest that adhesion with the correlated spreading of macrophages on glass dishes serve as a considerable physical factor for the release of 6KF1 alpha and TXB2.

6-Ketoprostaglandin F1 alpha↗

Chemical and biological properties of lipopolysaccharide from a marine bacterium, Photobacterium phosphoreum PJ-1.

The chemical and biological properties of the lipopolysaccharide (LPS) isolated from a marine bacterium, Photobacterium phosphoreum PJ-1, were studied. This LPS consists of 40.6% carbohydrate, 27.3% fatty acid, 0.2% 2-keto-3-deoxyoctonate (KDO) and other components. One characteristic of this LPS is its small amount of KDO, the basic component of the usual LPS. Electrophoresis in sodium dodecylsulfate polyacrylamide gel revealed at least two staining bands for carbohydrates. These bands were continuous and broad, and showed rapid electrophoretic mobility which corresponded closely to the fastest moving band of LPS from Salmonella typhimurium. This LPS preparation had adjuvant activity, lethality for ddY mice, and the ability to gel Limulus amebocyte lysate, and the strength of these activities corresponded closely to those of LPS preparations from Escherichia coli 0111:B4 and S. typhimurium. In the test for lethality of the LPS for ddY mice, the lethal action appeared in two phases depending on the dose used for intravenous (i.v.) injection: the early lethal action appeared within 30 min after injection of 250 micrograms or less, and the late lethal action occurred gradually after 16 hr at doses of 500 microgrms or more. The total (both phases) LD50 of this LPS (i.v.) for ddY mice was 265 micrograms per mouse and in only the late phase it was 500 micrograms. These results show that in spite of structural differences in regard to KDO content, LPS from P. phosphoreum PJ-1 has some biological properties similar to those of LPS from E. coli 0111:B4 and S. typhimurium but it shows no immunological cross-reaction with other LPS.

Carbohydrates↗