Biomedical subjects

Y Yanagihara

Publications and source records attributed to Y Yanagihara.

At least 37 records · Page 2Linked to original sources

PubMed1999

Determination of members of a Borrelia afzelii-related group isolated from Ixodes nipponensis in Korea as Borrelia valaisiana.

The 16S rRNA sequences of the Korean Borrelia strains 5MT and 9MT, isolated from Ixodes nipponensis, showed identities of 99.0-99.1% to that of B. afzelii. The strains were tentatively classified as belonging to the B. afzelii-related group. In this study, Korean isolates, including these strains, were characterized further and compared with recently described new species. These strains generated a RFLP pattern that has not been found previously in RFLP analysis of the 5S-23S rRNA intergenic spacer and the flagellin gene. When phylogenetic trees were constructed, based on the 5S-23S rRNA intergenic spacer, flagellin gene and 16S rRNA sequences, these Korean isolates formed a cluster with the Borrelia strain Am501 isolated from Ixodes columnae in Japan and Borrelia valaisiana strains VS116T and UK isolated from Ixodes ricinus in Europe and were distinguishable from the other species. However, these three groups of strains were divergent from each other in the molecular masses of the putative outer surface protein A (OspA) and in the sequences of the ospA gene. These findings suggest that these Korean isolates and one Japanese isolate are members of B. valaisiana and that OspA of this species is divergent, as is that of Borrelia garinii. This led to the speculation that B. valaisiana strains are adapted to the vector ticks found in each locality.

Animals↗

PubMed1999

International multicenter evaluation of the clinical utility of a dipstick assay for detection of Leptospira-specific immunoglobulin M antibodies in human serum specimens.

We performed a multicenter evaluation of a robust and easily performed dipstick assay for the serodiagnosis of human leptospirosis. The assay is aimed at the detection of Leptospira-specific immunoglobulin M (IgM) antibodies. The study involved 2,665 serum samples collected from 2,057 patients with suspected leptospirosis in 12 countries on five continents with different levels of endemicity and different surveillance systems. The patients were grouped as laboratory-confirmed leptospirosis case patients and noncase patients based on the results of culturing and the microscopic agglutination test. Paired samples from 27.7% of the subjects were tested. Of the 485 case patients, 87.4% had a positive dipstick result for one or more samples. Of the 1,513 noncase patients, only 7.2% had a positive result. Whereas most (88.4%) of the positive samples from the case patients showed moderate to strong (2+ to 4+) staining in the dipstick assay, most (68.1%) of the positive samples from the noncase patients showed weak (1+) staining. The sensitivity of the dipstick assay increased from 60.1% for acute-phase serum samples to 87.4% for convalescent-phase samples. The specificities for these two groups of samples were 94.1 and 92.7%, respectively. The dipstick assay detected a broad variety of serogroups. The results of the dipstick assay were concordant (observed agreement, 93.2%; kappa value, 0.76) with the results of an enzyme-linked immunosorbent assay for the detection of specific IgM antibodies, a test which is often used in the laboratory diagnosis of current or recent leptospirosis. This study demonstrated that this easily performed dipstick assay is a valuable and useful test for the quick screening for leptospirosis; has a wide applicability in different countries with different degrees of endemicity; can be used at all levels of the health care system, including the field; and will be useful for detecting and monitoring outbreaks of leptospirosis.

Agglutination Tests↗

PubMed1999

Cord-blood-derived human cultured mast cells produce interleukin 13 in the presence of stem cell factor.

BACKGROUND: Mast cells have been regarded as a potential source of cytokines. Although the human mast cell line HMC-1 and human lung mast cells have been shown to produce interleukin (IL) 13, it still remains uncertain whether cord-blood-derived human cultured mast cells produce IL-13. METHODS: Human cultured mast cells were raised from cord blood cells in the presence of stem cell factor (SCF) and IL-6. Levels of IL-13 mRNA were examined by a semiquantitative reverse transcriptase-polymerase chain reaction. IL-13 levels in the supernatants were measured with an enzyme-linked immunosorbent assay. RESULTS: When the IgE-sensitized cultured mast cells were activated with anti-IgE, mRNA for IL-13 was amplified with a peak at 3 h after the stimulation. IL-13 was not detected in the supernatants of the activated mast cells in the absence of SCF, whereas the mast cells secreted significant amounts of IL-13 after the stimulation in the presence of SCF. Calcium ionophore A23187 also stimulated the mast cells to release IL-13 into the supernatant in the presence of SCF. CONCLUSIONS: These observations suggest that human mast cells can produce IL-13 under the condition with SCF. The cord-blood-derived human cultured mast cells will help in studying the functional properties of human mast cells in allergic diseases.

Calcimycin↗

PubMed1999

[Preparation of ketamine tablets for treatment of patients with neuropathic pain].

Ketamine is known to have distinguished analgesic effects without anesthetic when administered in a low dose. Since ketamine is not commercially available except injection forms, we prepared ketamine tablets for the home-care medication of patients with neuropathic pain. The direct compression or wet granulation method was employed to form 150 mg of tablets containing 50 mg of ketamine. The latter method was superior to the former one in terms of content uniformity, weight variation and disintegration tests of the tablets. Ketamine contents in the tablet prepared by the wet granulation method were unchanged for 12 weeks under the conditions of 25 degrees C and 75% relative humidity (RH). The Cmax and AUC0-3 h values for ketamine after administration of the tablet were slightly smaller than those of the syrup in a healthy volunteer. However, analgesic effects of the tablet was similar to that of the syrup in a patient with neuropathic pain. And the tablet was also effective for another four patients with neuropathic pain. These results indicate that ketamine tablets are useful for the home-care medication of patients with neuropathic pain.

Adult↗

PubMed1998

Vi-deficient and nonfimbriated mutants of Salmonella typhi agglutinate human blood type antigens and are hyperinvasive.

We generated nonfimbriated mutants from both Vi-positive and -negative Salmonella typhi to analyze the role of type 1 fimbriae and Vi-antigen in bacterial invasion. A Vi-defective mutant of S. typhi GIFU 10007-3 was more invasive than the wild-type strain GIFU 10007. The wild-type strain expressing Vi-antigen did not agglutinate both Saccharomyces cerevisiae and human erythrocytes but Vi-defective mutants were able to agglutinate S. cerevisiae and human erythrocytes. Nonfimbriated mutants from Vi-negative GIFU 10007-3 lost the ability to adhere to S. cerevisiae but still could agglutinate human erythrocytes. The Vi-negative mutant increased secreted proteins and became 5-fold more invasive than the wild-type strain. Nonfimbriated Vi mutants became 50-120-fold more invasive than the wild-type GIFU 10007. To determine why nonfimbriated Vi mutants still agglutinate human red blood cells, we searched bacterial proteins that could bind human blood-type antigens. We finally identified a candidate 37 kDa outer membrane protein that recognized fucosyl-galactose, a structure common to blood type A, B and H antigens.

ABO Blood-Group System↗

PubMed1998

Elevation of serum IgE level and peripheral eosinophil count during T lymphocyte-directed gene therapy for ADA deficiency: implication of Tc2-like cells after gene transduction procedure.

We have successfully carried out T-cell-directed gene therapy for a boy with severe combined immunodeficiency due to adenosine deaminase deficiency (ADA SCID) and unexpectedly found an elevation of serum IgE level and peripheral eosinophil count during the course. More than 90% of transduced cells cultured for 7-11 days before infusion into the patient were positive for CD8 and expressed Th2-type cytokine genes such as IL-4, IL-5 and IL-13. Furthermore, CD4(+) T-depleted PBMC (peripheral blood mononuclear cells) from the patient synthesized IgE in vitro by stimulation with IL-4. Collectively, these results suggested that Tc2-like cells in the transduced cells have distinct immunological functions to help IgE synthesis and activate eosinophils.

Adenosine Deaminase↗

PubMed1998

Cultured basophils but not cultured mast cells induce human IgE synthesis in B cells after immunologic stimulation.

By generating human mast cells and basophils from umbilical cord blood mononuclear cells cultured in the presence of appropriate cytokines, we investigated whether these two cultured cells could provide the cytokine and cell contact signals that are required to induce IgE synthesis in B cells. To activate cultured mast cells and basophils, cross-linking of cell surface high-affinity IgE receptor (Fc epsilonRI) was performed with specific antigen after sensitization with murine IgE. Upon Fc epsilonRI stimulation, basophils, but not mast cells, secreted significant amounts of immunoreactive IL-4 and IL-13 and expressed detectable CD40 ligand (CD40L) and a very low level of Fas ligand (FasL). These observations at the protein level were consistent with the data obtained at the gene transcriptional level, except for the faint expression of only IL-13 mRNA in mast cells. When added to normal human B cells, activated basophils induced IgE and IgG4 synthesis as well as soluble CD23 release. In contrast, neither IgE nor IgG4 synthesis could be induced by the interaction of B cells with activated mast cells, even in the presence of recombinant IL-4. The induction of IgE synthesis by activated basophils was completely abrogated by two neutralizing MoAbs against IL-4 and IL-13 and by a soluble form of CD40. This abrogation was accompanied by abolished mature C epsilon transcription in both cases. Addition of anti-FasL MoAb, however, did not significantly affect IgE induction mediated by activated basophils. These results demonstrate that unlike cultured mast cells, cultured basophils produce biologically active IL-4 and IL-13 and express functional CD40L after Fc epsilonRI stimulation, thereby contributing to IgE production by B cells, and suggest that relatively weak expression of FasL by cultured basophils is not involved in IgE regulation.

B-Lymphocytes↗

PubMed1998

Infectivity and arthritis induction of Borrelia japonica on SCID mice and immune competent mice: possible role of galactosylceramide binding activity on initiation of infection.

We investigated the relationship between the binding activity to galactosylceramide (GalCer) and the arthritis induction activity of Borrelia japonica. The B. japonica strains maintained the ability to induce arthritis in inbred C3H/HeN and immunodeficient SCID mice, but the ability was lower than that of Borrelia burgdorferi sensu stricto virulent strain 297. Histopathological changes were restricted to the joints, and a marked effusion of polymorphonuclear neutrophils into the joint space was found. The binding activity of B. japonica strains to GalCer was lower than that of the virulent strain 297 but higher than that of the high-passage strain 297. The lower infectivity and virulence of B. japonica may explain its lower binding ability to GalCer.

Animals↗

PubMed1998

Lyme disease Borrelia species in northeastern China resemble those isolated from far eastern Russia and Japan.

Fifty-nine Borrelia burgdorferi sensu lato culture isolates collected from northeastern China were characterized by 5S-23S rRNA intergenic spacer restriction fragment length polymorphism (RFLP) analysis and reactivity with monoclonal antibodies (MAbs). Among 59 culture isolates, 30 (50.8%) were Borrelia garinii and 17 (28.8%) were Borrelia afzelii, 2 were mixtures composed of B. garinii with RFLP pattern B and B. garinii with pattern C, and 9 were mixtures composed of B. garinii and B. afzelii. One isolate, ChY13p, produced a unique pattern and was identified as B. garinii based on analyses of 16S rRNA gene sequence, flagellin PCR-RFLP typing, and MAb reactivities. No Borrelia burgdorferi sensu stricto or Borrelia japonica isolates were detected. The results indicate that Lyme disease Borrelia species in northeastern China resemble those of Borrelia isolates from far eastern Russia and Japan.

Base Sequence↗

PubMed1997

Relationship between pathogenicity of Coxiella burnetii isolates and gene sequences of the macrophage infectivity potentiator (Cbmip) and sensor-like protein (qrsA).

Coxiella burnetii, the Q fever agent, is an obligate intracellular bacterium and survival in phagolysosomes is an important virulence factor. The present study was performed to determine the relationship between its pathogenicity and genes related to its survival in macrophages, i.e. macrophage infectivity potentiator and Q fever agent regulatory sensor-like protein. The sequence similarity was more than 99% among Japanese, European and American strains, and no relationship was found between pathogenicity in guinea pigs and these genes.

Bacterial Proteins↗

PubMed1997

Characterization of Borrelia garinii isolated from Lyme disease patients in Hokkaido, Japan, by sequence analysis of OspA and OspB genes.

The outer surface proteins OspA and OspB genes of clinical Borrelia garinii isolates (JEM1-8) from Hokkaido, Japan were sequenced. One strain, JEM4, has a single ospA gene which is similar to European B. garinii strains PBr (sequence homology value: 94.1%) and T25 (91.2%). Five of the other seven strains exhibit a homologous C-terminus (300 bp) on both ospA and ospB genes (88.7-97.3%). The other two strains seem to be derived from the five strains by ospA or ospB alterations. In a phylogenetic analysis based on ospA, these strains could be classified into B. garinii, but formed independent branches and separated from the typical B. garinii isolates from Europe and Russia.

Amino Acid Sequence↗

PubMed1997

Homogeneity of Borrelia japonica and heterogeneity of Borrelia afzelii and 'Borrelia tanukii' isolated in Japan, determined from ospC gene sequences.

Borrelia afzelii, B. japonica, and 'B. tanukii' isolated from various sources and geographical origins in Japan were characterized by restriction fragment length polymorphism (RFLP) analysis and sequencing analysis of the outer surface protein C (OspC) amplicon. B. afzelii and 'B. tanukii' generated variable RFLP patterns and differences in ospC gene sequence were confirmed. In contrast, 26 isolates of B. japonica generated one OspC RFLP type, and sequence similarity between B. japonica ranged from 96.4 to 99.7%. These finding suggests that B. japonica is unique in comparison with other members of B. burgdorferi sensu lato species with respect to homogeneity of the ospC gene.

Animals↗

PubMed1997

Possible role of nuclear factor-kappa B activity in germline C epsilon transcription in a human Burkitt lymphoma B cell line.

Nuclear factor-kappa B (NF-kappa B) plays a broad role in gene regulation, but it is not evident whether NF-kappa B acts as a messenger system for germline C epsilon transcription. We report here that the signaling cascade triggered by interleukin-4 (IL-4) or anti-CD40 monoclonal antibody (mAb) participates in NF-kappa B activation responsible for germline C epsilon transcription in a human Burkitt lymphoma B cell line, DND39. Both IL-4 and anti-CD40 mAb induced activation of phosphatidylinositol 3-kinase (PI3-kinase), translocation of a zeta isoform of protein kinase C, and nuclear expression of NF-kappa B. All such events were abrogated by treatment with LY294002, a specific inhibitor of PI3-kinase. In addition, N-acetyl-L-cysteine (NAC), a potent antioxidant, decreased NF-kappa B activation caused by IL-4, anti-CD40 mAb, or their combination. NAC was also effective in diminishing germline C epsilon transcription, and its potency was higher in cultures costimulated with IL-4 and anti-CD40 mAb than in those stimulated with IL-4 alone. These results indicate that IL-4 and ligation of CD40 induce NF-kappa B expression via at least a mechanism dependent on the PI3-kinase pathway and suggest that NF-kappa B sensitive to NAC may play a role in regulating germline C epsilon transcription.

Acetylcysteine↗

PubMed1997

Sexual selection in Japanese macaques I: female mate choice or male sexual coercion?

Mate choice is defined as a behavioural pattern in one sex which increases the probability of fertile matings with certain members of the opposite sex. The chosen sex may use force, however, to coerce matings from reluctant members of the choosing sex. In a confined group of Japanese macaques, Macaca fuscata fuscatahoused at the Primate Research Institute of Kyoto University, Japan, behavioural and endocrine data were combined to assess the validity of several mate-choice behaviours and the potential influence of sexual coercion. Preliminary evidence was found for both female mate choice of males and male sexual coercion of females. Both female proximity maintenance towards males and male aggression towards females were correlated with an increase in fertile matings. Most male aggression appeared to be the by-product of increased time spent in proximity due to female proximity maintenance, but some male aggression appeared to be sexual coercion. These results are interpreted in light of recent research on male sexual coercion, and a tentative model of mate choice for this species is proposed.1997The Association for the Study of Animal Behaviour

Journal Article↗

PubMed1997

Sexual selection in Japanese macaques II: female mate choice and male-male competition

Mating and reproductive outcomes are the product of the potentially conficting strategies of breeding males and females. In a captive group of Japanese macaques, Macaca fuscata fuscatabehavioural, endocrine and genetic data were combined to assess the independent effects of male-male competition and female mate choice on mating and reproductive success. Males were ranked by social dominance and by their attractivity to females. Computer simulation and logistic regression analyses showed that male attractivity had a stronger effect than male dominance on both mating and reproductive outcome. Although male dominance and attractivity both significantly predicted mating success during fertile periods, only male attractivity significantly predicted actual male reproductive success. These results provide evidence that female mate choice can be a stronger determinant of mating and reproductive outcome in this species when male and female strategies are in conflict. The lack of a consistent correlation between male dominance rank and reproductive success in this species may be accounted for in part by female mate choice of socially subordinate males. Sires who were observed to mate with the mother during her fertile period were more likely to be socially dominant than sires who were not observed to do so. This observation suggests the existence of alternative mating strategies by subordinate males, which may also contribute to the lack of a consistent correlation between male dominance rank and reproductive success in this species.1997The Association for the Study of Animal Behaviour

Journal Article↗

PubMed1997

A thiol antioxidant regulates IgE isotype switching by inhibiting activation of nuclear factor-kappaB.

The binding site for nuclear factor-kappaB (NF-kappaB) is present at the promoter region of the germline Cepsilon gene, but there is little information on whether this factor is involved in regulating IgE synthesis by human B cells. Accordingly, we studied the role of NF-kappaB in germline Cepsilon transcription by using two human Burkitt's lymphoma B cell lines, DND39 and DG75. In both cell lines, n-acetyl-L-cysteine (NAC), a potent thiol antioxidant, inhibited the triggering of the nuclear expression of NF-kappaB by IL-4 and by anti-CD40 monoclonal antibody. Although IL-4 activated signal transducers and activators of transcription (STAT) 6 in addition to NF-kappaB, NAC treatment or the transfection of decoy oligodeoxynucleotides for NF-kappaB or STAT6 only partly blocked IL-4-induced germline Cepsilon transcription. However, these two decoy oligodeoxynucleotides together almost completely abrogated IL-4-induced germline Cepsilon transcription. Of note, CD40-mediated enhancement of IL-4-driven germline Cepsilon transcription was markedly decreased by NAC or by a decoy oligodeoxynucleotide for NF-kappaB. The effect of NAC was also examined on deletional switch recombination underlying the isotype switch to IgE. NAC inhibited the generation of Smu/Sepsilon switch fragments in normal human B cells costimulated with IL-4 and anti-CD40 monoclonal antibody. It also abolished IL-4-induced upregulation of CD40 but promoted upregulation of CD23. These results suggest that coordination of NF-kappaB and STAT6 may be required for induction of germline Cepsilon transcription by IL-4, and that CD40-mediated NF-kappaB activation may be important in regulating both enhancement of germline Cepsilon transcription and class switching to IgE.

Acetylcysteine↗

PubMed1997

A complex of histamine/mouse gamma-globulin preferentially inhibits allergen-induced peritoneal accumulation of eosinophils, but not neutrophils, in mice.

A complex of histamine/human gamma-globulin (HhG) has been widely used in Japan for more than 25 years as a nonspecific hyposensitization drug in the treatment of allergic diseases. It has been reported that HhG decreases the number of eosinophils in the nasal secretions and peripheral blood of patients with allergy. In this study we used a mouse system to explore the possibility that HhG may actively inhibit the accumulation of eosinophils at inflammation sites. A complex of 0.15 microg of histamine dihydrochloride/12 mg of mouse gamma-globulin (HmG) was incubated for 2 hours in saline solution in the normal fashion for HhG. HmG at 50 to 150 mg/kg/day inhibited the peritoneal accumulation of eosinophils induced by ragweed pollen in BALB/c mice in a dose-dependent fashion when the HmG was administered subcutaneously six times during a 20-day sensitization period. The inhibitory effect of HmG on this eosinophil accumulation was significant at 24 and 48 hours after challenge, but HmG had no effect on neutrophil accumulation. Complexes of serotonin/mouse gamma-globulin (mgammaG), glutamine/mgammaG, and histamine dihydrochloride (His)/mouse albumin had no inhibitory effect when administered in the same way. The optimum combination ratio was between 0.15 microg of His/12 mg of mgammaG and 0.015 microg of His/12 mg of mgammaG for this eosinophil inhibition. Moreover, a 1- to 2-hour incubation period of His and mgammaG was needed to induce a plateau inhibition of the eosinophil accumulation. These results in mice suggest that HhG may actively inhibit allergen-induced eosinophil accumulation, which may be therapeutically useful in the treatment of allergic disease.

Allergens↗

PubMed1997

Induction of human IgE synthesis in B cells by a basophilic cell line, KU812.

Induction of human IgE synthesis in B cells requires, in addition to IL-4 or IL-13, a second signal provided by CD40 ligand (CD40L) on activated Th2-type CD4+ T cells that do not or weakly express Fas ligand (FasL). Mast cells and basophils also produce IL-4 or IL-13 and express CD40L after immunologic or pharmacologic stimulation, although it is unknown whether these cells express FasL. This study investigated the capacity of KU812 cells, a human basophilic cell line, to produce IL-4 and IL-13, to express CD40L and FasL, and to induce IgE and IgG4 synthesis in human normal B cells. Upon stimulation of KU812 cells with either phorbol myristate acetate (PMA) or ionomycin (Iono), IL-4, but not IL-13, was produced in response to Iono, while IL-13, but not IL-4, was inducible by PMA. Moreover, both the time courses of IL-4 and IL-13 production and their amounts secreted were different; IL-4 production was transient, IL-13 production gradually increased, and IL-13 was heavily secreted as compared with IL-4. The combination of PMA and Iono (PMA/Iono) induced higher production of IL-4 or IL-13 than did Iono or PMA alone. KU812 cell-derived IL-4 and IL-13 had the ability to cause CD23 expression on B cells. PMA/Iono also up-regulated CD40L expression and induced a very low level expression of FasL. KU812 cells that had been activated by PMA/Iono followed by fixation could induce IgE and IgG4 synthesis in B cells in the presence of recombinant IL-4 or IL-13. This contact-dependent induction of IgE was completely abrogated by adding anti-CD40L MoAb or soluble CD40, whereas anti-FasL antibody did not significantly affect IgE production. These results indicate that activated KU812 cells produce biologically active IL-4 and IL-13, express functional CD40L, and exhibit weak induction of FasL, thereby supporting sufficient IgE production by B cells.

B-Lymphocytes↗