Search PubMed⌕ Search

Biomedical subjects

Y Nakase

Publications and source records attributed to Y Nakase.

At least 55 records · Page 3Linked to original sources
PubMed1986

Effect of Bordetella heat-labile toxin on perfused lung preparations of guinea pigs.

In vitro effects of the Bordetella HLT on the isolated perfused lung and some other tissue preparations from guinea pigs were examined. When HLT (30 to 300 MNDs/ml) was administered, an increase of the perfusion pressure was induced in the perfused lungs, indicating vasoconstriction. When 100 or 300 MNDs/ml of HLT was given, the pressure increase appeared after a lag period of 3.5 to 4 min, reached a maximum within 8 to 13 min, and then slowly decreased by 60 to 80% 25 min after exposure. In calcium-free medium, the pressure increase due to HLT did not occur, but these HLT-treated lungs manifested an increase without any lag period immediately after the calcium-free medium was replaced by normal medium containing calcium. No difference in the response of the perfused lungs to histamine was observed before and after exposure to HLT. The arterial strip did not respond to HLT, but after predigestion with a collagenase and elastase solution the contractive response to 100 MNDs/ml of HLT appeared with a lag period of 1 min. HLT had no effect on the pharmacological responses of the isolated atria, deferent canal or intestinal preparations, or on the ciliary movement of cultured tracheal rings.

Animals↗
PubMed1986

[Pertussis].

Explore the source record for details and available documents.

Adenylyl Cyclases↗
PubMed1986

[OMRON RF hyperthermia treatment system HEH-500 C].

The RF capacitive type hyperthermia system "HEH-500 C" enables regional heating for superficial and deep seated tumors. It consists of a high frequency generator (frequency; 13.56 MHz, out put power; 500 watts), a control unit, a cooling unit for the applicators, an I/F unit (communicate the thermometer to RF generator and plotter printer), a thermometer (thermocouple thermometer or fiber fluorothermometer) and a plotter printer. Heating profile of HEH-500 C was presented with thermographic picture on TX-150 muscle equivalent phantom. Effects of bone and fat layer on heating profile of phantom were also examined. Points to be solved on thermometry, electromagnetic field environment and clinical use were also discussed.

Humans↗
PubMed1985

Bordetella heat-labile toxin: further purification, characterization and mode of action.

The heat-labile toxin (HTL) was purified from sonic extracts of Bordetella bronchiseptica and Bordetella pertussis cells by a series of hydrophobic interactions, density gradient centrifugation, gel filtration, isoelectric precipitation, and isoelectric focusing. A 114-fold purification was regularly obtained with a yield of 31%. A dose of 0.75 ng was dermonecrotizing in guinea pigs. HLT is a simple protein (pI 6.9) with a molecular weight by gel filtration of 102,000 which consists of two polypeptides of 30,000 and 24,000 molecular weight. Amino acid analysis showed 15 common amino acids and the absence of methionine. The dermonecrotizing activity was inactivated at 56 degrees C, and at above pH 10 or below pH 5. Effects of various ions, detergents, enzymes and other chemical agents on HLT were determined. When instilled on the surgically exposed peripheral blood vessels of guinea pigs or suckling mice, HLT induced vasoconstriction within 15 min resulting in the decrease of blood flow, followed by manifestations of ischemia, diapedesis and petechial hemorrhage during the following 5 h. HLT activity on arterioles was unaffected by adrenergic or cholinergic blockades. Biochemically, HLT significantly inhibited in vitro the activity of Na+ - K+ ATPase prepared from rat kidney. A possible mechanism by which HLT induces dermohemorrhagic necrosis and splenic atrophy, is discussed.

Animals↗
PubMed1983

In vitro induction of altered response of rat atria to acetylcholine with histamine-sensitizing factor of Bordetella pertussis.

Purified histamine-sensitizing factor (HSF) of Bordetella pertussis induced in vitro an alteration in the pharmacologic response of rat atria to acetylcholine. Spontaneously beating atrial preparations isolated from rats were exposed to HSF at a concentration of 50 ng/ml at 37 C for 30 min to 4 hr and washed with Krebs-Ringer solution, and then tested at 1-hr intervals up to 28 hr during incubation for their responses to epinephrine and acetylcholine. At 13 hr after exposure to HSF, irrespective of the exposure period, the HSF-treated atria, in which positive-inotropic action of epinephrine was manifested, depressed the negative-inotropic response to acetylcholine. The activity of HSF was neutralized by anti-HSF serum only in the first 3 hr exposure. Only 1.8% of the added 125I-labeled HSF bound "specifically" to one pair of atria for the manifestation of the altered response.

Acetylcholine↗
PubMed1983

Protection against experimental Bordetella bronchiseptica infection in mice by active immunization with killed vaccine.

Mice immunized with a killed vaccine of phase I Bordetella bronchiseptica were challenged with various numbers of virulent B. bronchiseptica by intraperitoneal, intracerebral, or intranasal routes. The course of infection was compared among these routes, and the protective effect of vaccination was quantitatively analyzed. In ddN mice infected intraperitoneally with 1.8 X 10(8) cells (ca. 80 times the 50% lethal dose [LD50]) the organisms rapidly increased in the intraperitoneal fluid, spleen, and liver within few days and caused splenic atrophy, septicemia, and death. However, immunizations with 5 X 10(9) cells gave the mice a high agglutinin titer and suppressed the increase in the number of organisms. With four immunizations, the lungs and livers were clear within 3 days, and with one or two immunizations, they were clear within 7 days. These immunizations effectively protected the mice from death but did not protect them from splenic atrophy. In the intracerebral infection with 1.4 X 10(6) cells (ca. 1.2 X 10(5) LD50), the number of organisms rapidly increased in the brain and caused encephalitis, splenic atrophy, and death. However, four or five immunizations completely suppressed the increase in the brain and protected the mice from death and splenic atrophy. After intranasal infection with 4 X 10(6) cells (ca. 25 LD50), the organisms rapidly increased in the nasal cavity and lungs and caused pneumonia and death. Immunization with 5 X 10(9) cells was effective in clearing the organisms from the lungs and in protecting against death and splenic atrophy. However, the organisms were not cleared from the nasal cavity for 60 to 150 days after the challenge with as little as 10(2) cells, even in the mice with an agglutinin titer as high as 1:10,000.

Animals↗
PubMed1982

Effect of histamine-sensitizing factor of Bordetella pertussis on pharmacologic response of rat atria.

The effects of sensitization with the histamine-sensitizing factor (HSF) of Bordetella pertussis as well as Bordetella vaccines on a pharmacologic response in rat heart preparations were determined. In normal rats the spontaneous beating of atria in vitro through the positive inotropic action produced by the addition of epinephrine was inhibited immediately by addition of acetylcholine, whereas in the B. pertussis vaccine-treated rats the exciting atria were scarcely inhibited by acetylcholine. Neither B. parapertussis nor B. bronchiseptica vaccines induced such an altered atrial response in rats. Of the B. pertussis cell components purified HSF induced the altered response at the minimal dose of 0.1 microgram per rat, and a dose of 1 microgram or more produced the maximal change. This altered atrial-inducing activity of HSF was inactivated by heating at 63 C for 30 min, and was neutralized by anti-HSF rabbit serum. The altered response rose quickly in 1 day after i.v. injection of 1 microgram of HSF, reached a plateau in 3 to 5 days, which lasted at least 14 days, and disappeared completely 56 days later. HSF failed to produce directly any functional damage to the beating atria in vitro, and to induce the altered response of the normal rat atria by incubation with as much as 10 microgram of HSF per bath (50 ml) for 4 hr. A trace stimulation was found in the normal rat atria as well as in perfused frog hearts, if HSF was given directly at a dose of 20 microgram per bath.

Acetylcholine↗
PubMed1982

Glycerol-releasing activity of histamine-sensitizing factor of Bordetella pertussis for rat adipocytes in vitro.

Histamine-sensitizing factor (HSF) purified from Bordetella pertussis induced specifically the release of glycerol from rat epididymal adipocytes in vitro. The most sensitive and reproducible results were obtained by using 1 to 2 x 10(5) adipocytes/tube from rats weighing 150 to 200 g, and by incubation at 37 C for 180 min. After a lag period of about 60 min, HSF-treated adipocytes released glycerol in increasing amounts between 60 and 240 min, depending on the dose of HSF. A close correlation between the glycerol-releasing (GR) activity of HSF for adipocytes and histamine-sensitizing or leukocytosis-promoting activity in mice was observed. The GR activity was inactivated by heating at 56 C for 60 min, 63 C for 30 min or 96 C for 10 min. The adipocytes washed out with a Krebs-Ringer bicarbonate buffer immediately after being exposed to HSF for 1 to 3 min manifested about 75% of the total GR activity induced by HSF, and those washed out after being exposed for 30 min or longer had full activity. Anti-HSF serum neutralized the activity when it was added to adipocytes simultaneously with HSF, but did not when it was added 30 min after being exposed to HSF. By using both native and 125 I-labeled HSF, the ratio of binding of HSF to adipocytes was estimated to be 10 to 15% of the total HSF per 2 x 10(5) cells/tube, and to be about 1,000 molecules of HSF per cell to induce the release of glycerol. The GR activity induced with 10 ng of HSF was inhibited by addition of insulin at a dose of over 1 micro IU/tube, but not by concanavalin A.

Adipose Tissue↗
PubMed1982

Mutant of Bordetella pertussis which lacks ability to produce filamentous hemagglutinin.

Mutant cultures that lacked the ability to produce filamentous hemagglutinin were obtained by UV irradiation of Bordetella pertussis strain 18-323. Various biological activities of these mutants were compared with those of the parent culture. It was found that the leukocytosis-promoting, histamine-sensitizing, and mouse-protecting activities of the mutants were similar to those of the parent strain but that the virulence to mice was lower. The results seemed to rule out fimbrial hemagglutinin as a protective antigen when the ability to protect mice was measured by the intracerebral challenge test.

Agglutination↗