Biomedical subjects

Y Kumazawa

Publications and source records attributed to Y Kumazawa.

At least 73 records · Page 4Linked to original sources

PubMed1991

Effect of methyl esterification of isoglutamine residue in 6-O-acylated muramyl dipeptides on expression of immunopharmacological activities.

The effect of methyl esterification of the isoglutamine residue in 6-O-acylated muramyl dipeptide (MDP) on some biological activities was investigated. Methyl esterification influenced more or less the expression of all activities tested. The adjuvant and colony stimulating factor (CSF)-inducing activities of 6-O-acylated MDP analogs carrying a 3-hexadecanoyloxytetradecanoyl [C14-O-(C16)] group were stronger than those of the corresponding analogs carrying a 2-tetradecylhexadecanoyl (B30) group. Macrophage activation, i.e. induction of tumor necrosis factor (TNF) and promotion of phagocytosis, by 6-O-C14-O-(C16)-MDP methyl esters was weaker.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1991

Unilateral aminoacylation specificity between bovine mitochondria and eubacteria.

The present study shows unilateral aminoacylation specificity between bovine mitochondria and eubacteria (Escherichia coli and Thermus thermophilus) in five amino acid-specific aminoacylation systems. Mitochondrial synthetases were capable of charging eubacterial tRNA as well as mitochondrial tRNA, whereas eubacterial synthetases did not efficiently charge mitochondrial tRNA. Mitochondrial phenylalanyl-, threonyl-, arginyl-, and lysyl-tRNA synthetases were shown to charge and discriminate cognate E. coli tRNA species from noncognate ones strictly, as did the corresponding E. coli synthetases. By contrast, mitochondrial seryl-tRNA synthetase not only charged cognate E. coli serine tRNA species but also extensively misacylated noncognate E. coli tRNA species. These results suggest a certain conservation of tRNA recognition mechanisms between the mitochondrial and E. coli aminoacyl-tRNA synthetases in that anticodon sequences are most likely to be recognized by the former four synthetases, but not sufficiently by the seryl-tRNA synthetase. The unilaterality in aminoacylation may imply that tRNA recognition mechanisms of the mitochondrial synthetases have evolved to be, to some extent, simpler than their eubacterial counterparts in response to simplifications in the species-number and the structural elements of animal mitochondrial tRNAs.

Amino Acyl-tRNA Synthetases↗

PubMed1991

Gamma interferon production in endotoxin-responder and -nonresponder mice during infection.

The production of gamma interferon (IFN-gamma) in response to infection and to a number of other agents was compared in Lpsn (C3H/HeN and C57BL/10ScSn) and Lpsd (C3H/HeJ and C57BL/10ScCr) mouse strains. Large differences in IFN-gamma production were observed between C57BL/10ScCr mice and the other mouse strains. With the exception of C57BL/10ScCr, all mouse strains, including C3H/HeJ, exhibited transient levels of IFN-gamma during infection with Salmonella typhimurium. Spleen cells of these mice, explanted on day 3 of infection, produced in vitro IFN-gamma spontaneously; this production was enhanced considerably by heat-killed S. typhimurium, heat-killed Propionibacterium acnes, concanavalin A (ConA), or lipopolysaccharide (LPS). These stimuli, except for LPS, also induced IFN-gamma production in cultures of normal spleen cells from noninfected animals. In contrast, C57BL/10ScCr mice produced no IFN-gamma following infection with S. typhimurium. Also, spleen cells of these mice, explanted on day 3 of infection, exhibited no spontaneous IFN-gamma production. A marginal response was obtained by additional stimulation of the cells with killed S. typhimurium, and a moderate response was obtained with ConA. Normal spleen cells from noninfected C57BL/10ScCr mice showed no IFN-gamma response to killed S. typhimurium, killed P. acnes, or LPS and only a low response to ConA. Impaired IFN-gamma production in C57BL/10ScCr mice was also evident during infection with Plasmodium chabaudi chabaudi, with which a low IFN-gamma response was seen only occasionally. Also, spleen cells from infected animals (days 2 to 8 after infection) exhibited only a very low level of IFN-gamma production in vitro; however, this production could be enhanced further by ConA. In comparison, C57BL/10ScSn mice infected with P. chabaudi chabaudi produced significant amounts of IFN-gamma. Spleen cells explanted from infected animals produced IFN-gamma spontaneously in vitro; this production was enhanced further by killed P. acnes and ConA. The results showed that in addition to the defect in LPS responsiveness, C57BL/10ScCr mice possess a defect in IFN-gamma production in response to different stimuli. During infection, IFN-gamma production and sensitization to LPS occurred in parallel. Infected Lpsn mice exhibited enhanced sensitivity and infected Lpsd C3H/HeJ mice exhibited reasonable sensitivity to the lethal effects of LPS. Lpsd C57BL/10ScCr mice remained resistant to LPS when infected with S. typhimurium and exhibited only marginal sensitivity when infected with P. chabaudi chabaudi.

Animals↗

PubMed1991

Formation of interferon-gamma and tumor necrosis factor in mice during Salmonella typhimurium infection.

Formation of interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF) during Salmonella typhimurium infection was investigated in lipopolysaccharide (LPS)-sensitive C3H/HeN and C57BL/10ScSn(B10ScSn), and LPS-resistant (lpsd mutant) C3H/HeJ and C57BL/10ScCr(B10ScCr) mice. When infected with 50 colony-forming units (CFU) of S. typhimurium C5, C3H/HeN and B10ScSn mice became hypersensitive to the lethal effect of LPS. In the case of lpsd mutants, only C3H/HeJ mice became hypersensitive to LPS, while B10ScCr mice remained resistant. C3H/HeJ as well as B10ScSn mice produced significant amounts of plasma IFN-gamma on day 3 after infection. By this time bacterial CFU in the liver of B10ScSn and C3H/HeJ mice were 10(6.7) and 10(7.1), respectively. In B10ScCr mice, however, IFN-gamma was not detectable although bacteria present in the liver exceeded 10(8) CFU. On the other hand, plasma TNF was not detectable in any of the mouse strains during S. typhimurium infection. When S. typhimurium-infected mice were challenged with LPS on day 3, significant amounts of plasma TNF were measured in C3H/HeN and B10ScSn mice, while in the lpsd mutant C3H/HeJ and B10ScCr mice plasma TNF was undetectable.

Animals↗

PubMed1991

Mitogenic and colony-stimulating factor-inducing activities of polysaccharide fractions from the fruit bodies of Dictyophora indusiata Fisch.

Biological effects (mitogenic and colony-stimulating factor (CSF)-inducing activities) of five homogeneous polysaccharides and a conjugated polysaccharide fraction isolated from the fruit bodies of Dictyophora indusiata Fisch. were investigated. Fucomammogalactan (T-3-Ad) and conjugated polysaccharide fraction (T-2-A) exhibited significant mitogenic and CSF-inducing activities. Among two beta-(1----6)-branched (1----3)-beta-D-glucans (T-4-N and T-5-N), only T-4-N showed both mitogenic and CSF-inducing effects. Partially O-acetylated (1----3)-alpha-D-mannans (T-2-HN and T-3-M') did not show these effects.

Animals↗

PubMed1991

Structure of mitochondrial tRNA.

Some mitochondrial (mt) tRNAs are presumed to have unusual secondary structures on the basis of DNA sequence analyses. However there are few tRNAs whose structures have been investigated at RNA level. Thus we isolated some mt tRNAs to investigated their structures and also synthesized mt tRNA by run-off transcription. In these experiments, following results have been obtained. 1) Bovine mt tRNA(Ser)(AGY) needs the interaction between the T-loop and D-arm for its aminoacylation activity. 2) The secondary structure of bovine mt tRNA(Ser)(UCN) is difficult from that predicted previously from its gene. 3) It has been confirmed by the hybridization using oligonucleotide probes that some Ascaris suum mt tRNAs possessing the unusual T-arms actually exist in its mitochondria.

Animals↗

PubMed1991

Structural and biological comparison of lipopolysaccharides (LPS) from Bordetella species.

Lipopolysaccharides (LPS) isolated from Bordetella pertussis (Bp), B. parapertussis (Bpp), and B. bronchiseptica (Bbs) were analysed for their chemical composition, molecular heterogeneity, and immunological and biological properties. All LPS contained heptose, KDO, GlcN, uronic acid, phosphate, and fatty acids. The fatty acids C14:0, C16:0 and 3-OHC14:0 were common to all LPS preparations. By SDS-PAGE, Bp-LPS had two bands of low molecular mass, and Bpp- and Bbs-LPS showed a low molecular mass band together with ladder bands of high molecular mass. Immunological assays demonstrated that Bp-LPS reacted with antisera prepared from Bp and Bpp; Bpp-LPS reacted with antisera against Bpp and Bbs, and Bbs-LPS reacted with antisera against any of the three species. Bp-LPS showed biological activities comparable to those of E. coli LPS in terms of lethal toxicity, pyrogenicity, mitogenicity, macrophage activation, and induction of tumor necrosis factor. All activities of Bpp-LPS, except mitogenicity, were lower than those of E. coli LPS. Biological activities stronger or comparable to those of E. coli LPS were observed for Bbs-LPS.

Animals↗

PubMed1991

Sequence specific purification of a particular tRNA by solid phase DNA probe.

A novel method for the purification of a specific tRNA using solid phase DNA probe is developed. With this method, the probe DNA immobilized on HPLC gel hybridized with target tRNA within a minute at room temperature. The hybridizing capacity of the solid phase probe was about 20 O.D. per gram dry gel when yeast phenylalanine tRNA was used. The specificity of this method was extremely high and the recovery rate was about 90%.

Base Sequence↗

PubMed1990

Biological properties of lipopolysaccharides isolated from Bordetella.

Biological activity of lipopolysaccharides (LPSs) separated from Bordetella, i.e., B. pertussis (Bp), B. parapertussis (Bpp) and B. bronchiseptica (Bbs), was determined and compared with that of an Escherichia coli LPS as a control. Two Bp-LPS preparations showed marked biological activities comparable to those of E. coli LPS in terms of lethal toxicity in galactosamine-sensitized mice, pyrogenicity in rabbits, mitogenicity in C3H/He spleen cell cultures, macrophage activation and tumor necrosis factor-inducing activity. All the activities except mitogenicity of two Bpp-LPS preparations were lower than or comparable to those of E. coli LPS. Activities stronger than or comparable to those of E. coli LPS were observed in two Bbs-LPS preparations. Among six LPS preparations from Bordetella tested, a Bbs-LPS from L3 strain exhibited the most intensive activities.

Animals↗

PubMed1990

Structure-activity relationship of chemically synthesized nonreducing parts of lipid A analogs.

Some synthetic compounds of the nonreducing part of lipid A were found to preserve significant immunopharmacological activities of the endotoxin, at the same time showing very slight if any endotoxic activity such as pyrogenicity lethality or Shwartzman reactivity. Thus, divers activities of the endotoxin which had earlier been considered intrinsic and inseparable were shown to be separable when certain synthetic analogs of lipid A-subunit are at work. The combination of acyl components as well as phosphorylation and acylation positions in these partial structure analogs of lipid A affect the expression of biological activities of the endotoxin. Moreover, stereospecificities of acyl substituents contribute differently to enhance the various biological activities of the endotoxin. It was remarkable that protective activities of the endotoxin such as enhancing nonspecific resistance against microbial infections and antitumor activity are preserved in lipid A-subunit analogs of small molecular weight of ca. 1,000, which at the same time lose all or most toxic activity such as pyrogenicity, lethality and Shwartzman reactivity. It is hoped that new derivatives of lipid A and/or lipid A-subunit which exert only limited biological activities of endotoxin, whether they be protective or toxic, can be synthesized in order to clarify the structural requirements for expressing a given activity. Such compounds will be useful not only for promoting basic endotoxin research but also for application in clinical medicine. Further detailed experiments on the structure-activity relationships of the newly synthesized 4-O-phosphono-D-glucosamine derivatives binding acyl substituents of varying carbon chain length at the 2-N- and 3-O- positions are in progress.

Animals↗

PubMed1990

Enhancement of nonspecific resistance to microbial infections of synthetic lipid A-subunit analogues of GLA-27 modified at the C1 position of the glucosamine backbone.

The C1 position of lipid A-subunit analogue GLA-27, 4-O-phosphono-D-glucosamine carrying N-3-tetradecanoyloxytetradecanoyl(C14-O-(C14)) and 3-O-tetradecanoyl (C14) groups, was S-acetylated, thiolated or phosphorylated. Enhancement of nonspecific resistance to Pseudomonas aeruginosa and vaccinia virus infections of these chemically modified compounds were investigated. Thiolation augmented the nonspecific resistance to P. aeruginosa infection. Protective activity against vaccinia virus infection was reduced by all the chemical modifications. NK cell activity was found not to be effected by S-acetylation, but to be decreased slightly by thiolation or phosphorylation. IFN-inducing activity was reduced remarkably by thiolation or S-acetylation, or completely diminished by phosphorylation, compared with that of GLA-27.

Animals↗

PubMed1990

Induction of interferon after administration of a traditional Chinese medicine, xiao-chai-hu-tang (shosaiko-to).

We examined the ability of a traditional chinese herbal medicine, xiao-chai-hu-tang (Japanese name: shosaiko-to) to induce IFN in mice. A maximum activity (105 units/ml) of interferon (IFN) appeared in the serum of mice 16 h after intraperitoneal (i.p.) treatment with 250 mg/kg of shosaiko-to. Addition of polymyxin B did not abrogate the ability of shosaiko-to to induced serum IFN. The IFN was identified as IFN-alpha/beta by neutralizing test using anti-IFN alpha/beta antibodies. Pretreatment of mice with carrageenan suppressed the IFN induction by shosaiko-to, whereas the IFN induction by shosaiko-to was impaired neither in mice treated with anti-asialo-GM1 antibody nor in T-cell-deficient athymic nude mice. IFN was produced in vitro by spleen cells obtained from shosaiko-to treated mice. Moreover, spleen cells from untreated mice could also produce IFN when they were cultured with shosaiko-to. Additionally, serum IFN was also induced by the adoptive transfer of spleen cells from shosaiko-to treated mice to normal mice. On the other hand, peroral administration of shosaiko-to also induced IFN-alpha/beta in the serum. While IFN activity induced by i.p. administration of shosaiko-to declined after repeated treatments, the activity induced by its peroral administration did not decline during a long term treatment. These results showed that shosaiko-to is an IFN-alpha/beta inducer capable of repeated peroral administration.

Administration, Oral↗

PubMed1990

Accelerated recovery from gamma-irradiation-induced leukopenia in mice by the biscoclaurine alkaloid, Cepharanthin--comparison with recombinant human granulocyte colony-stimulating factor.

The effect of a biscoclaurine alkaloid drug, Cepharanthin (CE), on recovery from severe leukopenia induced by whole body gamma-irradiation at a dose of 3 Gy, was compared with that of recombinant human granulocyte colony-stimulating factor (rhG-CSF). Daily intraperitoneal administration of 100 micrograms CE into the irradiated mice significantly prevented decrease of leukocyte numbers in the peripheral blood and accelerated recovery from leukopenia to normal. The activity of CE was somewhat weaker than that of 20,000 units of rhG-CSF when administered daily subcutaneously. In cell composition of peripheral leukocytes, CE increased the numbers of polymorphonuclear (PMN) cells and lymphocytes compared with those of the irradiated controls. Stronger change in PMN cell numbers than with CE was induced by administration of rhG-CSF. No significant increment of the activity to form colonies in spleen (colony-forming unit in spleen; CFU-S) was observed in bone marrow cells from irradiated donor mice administered CE, though CE induced CSF production into sera. Administration of rhG-CSF stimulated the CFU-S activity. These results indicate that CE increased recruitment of PMN cells from the marginal pool rather than the stimulation of pluripotent stem cells in the bone marrow.

Alkaloids↗

PubMed1990

Protective effect of saikosaponin A, saikosaponin D and saikogenin D against Pseudomonas aeruginosa infection in mice.

Effects of saikosaponins and their genins on nonspecific resistance against Pseudomonas aeruginosa and Listeria monocytogenes infections were investigated. When mice were administered intraperitoneally (i.p.) saikosaponins one day before i.p. infection with P. aeruginosa, saikosaponins a and d induced a marked enhancement of nonspecific resistance at a dose of 10 micrograms/mouse. Also, saikogenin D, a secondary metabolite of saikosaponin d, showed an enhancing effect. The most effective condition for enhancing the nonspecific resistance was i.p. administration of saikosaponin d one day before i.p. or intravenous (i.v.) infection with P. aeruginosa, when mice were treated i.p., i.v., or subcutaneously with saikosaponin d 1, 4 or 7 days previously. Effect of saikosaponin d was weaker than that of formalin-killed bacilli of Propionibacterium acnes and lipopolysaccharide. On the other hand, effect of saikosaponin d on enhancement of nonspecific resistance against L. monocytogenes was not seen. Effector cells participating in the enhanced protection induced by saikosaponin d may be macrophages, since macrophages were a major component in peritoneal cells obtained from mice administered i.p. saikosaponin d 1 day earlier and intracellular bactericidal activity of peritoneal macrophages against P. aeruginosa increased.

Animals↗

PubMed1990

Biological properties of lipopolysaccharides from Bordetella species.

Biological activities of lipopolysaccharides (LPS) extracted from Bordetella pertussis, B. parapertussis and B. bronchiseptica were compared with those of Escherichia coli LPS. The LPS preparations from B. pertussis showed biological activities comparable to those of E. coli LPS in terms of lethal toxicity in galactosamine-sensitized mice, pyrogenicity in rabbits, mitogenicity in C3H/He spleen cell cultures, macrophage activation, and induction of tumour necrosis factor. All the activities of LPS preparations from B. parapertussis, except mitogenicity, were lower than those of E. coli LPS. LPS from B. parapertussis gave the greatest mitogenic action of all those tested. Biological activities stronger than or comparable to those of E. coli LPS were observed for LPS from B. bronchiseptica.

Animals↗

PubMed1990

[Protective activities of a Chinese medicine, hochu-ekki-to, to impairment of hematopoietic organs and to microbial infection].

Effect of Hochu-ekki-to (HET) on the number of peripheral leukocytes (PL) and their functions in cyclophosphamide (CY)-treated or gamma ray-irradiated mice was investigated. By treatment of mice with anticancer agent CY or gamma ray irradiation, unfavorable side effects usually occurred to impair hematopoietic organs, causing bone marrow disorder. However, it was significantly protected by oral administration of HET (1 g/kg/d) to CY-treated or gamma ray-irradiated mice. The numbers of neutrophils and monocytes in PL were restored to the normal level, and colony-stimulating factor (CSF) was induced in the sera of mice by HET in a dose-dependent manner. The induction of serum CSF reached a peak at 3h after HET administration. Colony-forming unit of bone marrow cells in the spleen adoptively transferred into syngeneic mice, that is defined as CFU-S, was extremely reduced by CY-treatment. However, when HET was orally administered, CFU-S of CY-treated mice was markedly stimulated, suggesting that bone marrow cells were reactivated for further proliferation and mobilization. HET enhanced other leukocyte functions in CY-treated mice; i.e., superoxide production of neutrophils and phagocytic activity of macrophages. Thus, oral administration of HET to CY-treated mice enforced protection against Pseudomonas aeruginosa infection.

Administration, Oral↗

PubMed1990

[A study of linearity and reciprocity during shock applied with a hammer to human dry skull].

The authors used a human dry skull on which the cranial bone mandible had been joined with an artificial articulator disk to form a single unit. Impact acceleration corresponding to weak and strong tapping was considered a dynamic load in examining the vibration transfer characteristics of the facial cranial bone when impact was applied from the mentum section in a situation designed to be closer to reality. Flexion injection type (resonance frequency f0 = 100 to 150 Hz, produced by GC Corp.) was applied to the human dry skull as an artificial periodontal membrane at thickness of 0.3 mm. In addition, Exaflex heavy body type (f0 = 400 Hz, produced by GC Corp.) was applied as an artificial disk. This was then placed on a damper produced by spreading a rubber dam sheet with a thickness of 35 microns on a tire tube with a diameter of 35 cm and an air pressure of 35 kg/cm2. Investigations were then made concerning linearity and reciprocity to determine whether an experimental system could be achieved or not. This was then followed by modal analysis. As a result, the following matters were ascertained: (1) The resonating area differed according to the extent of the force. (2) An increase in the viscoelastic elements of the silicon was accompanied by attenuation of force. (3) Directionality of force attenuation was caused by the complexity of bone structure. (4) A tapping force of 0.3G or 1G was sufficiently attenuated by the facial cranial bone. (5) The transfer function at the bone seams and thinner areas of the bones was insufficient for modal analysis of the facial region and total cranial bone of the human dry skull.

Biomechanical Phenomena↗

PubMed1990

[Anesthetic experience of a patient with blue rubber bleb nevus syndrome].

We report an anesthetic experience of a 63-year-old female patient with blue rubber bleb nevus syndrome who underwent an open reduction of the fracture of the right femur. The syndrome is characterized by bluish nevus scattered throughout the skin of the whole body and angiomas of the gastrointestional tract causing serious bleeding. Anesthesia was induced with thiopental followed by intravenous injection of succinylcholine chloride and maintained with neuroleptanesthesia in nitorous oxide and oxygen. The course of anesthesia and emergence from anesthesia were uneventful. Anesthetic management of patients with blue rubber bleb nevus syndrome was also discussed.

Female↗