PubMed Health⌕ Search

Biomedical subjects

K Nishizaki

Publications and source records attributed to K Nishizaki.

At least 19 recordsLinked to original sources
PubMed2006

Role of prostaglandin D2 and E2 terminal synthases in chronic rhinosinusitis.

BACKGROUND: Prostaglandin (PG)D(2) and E(2), two major cyclooxygenase (COX) products, are generated by PGD(2) synthase (PGDS) and PGE(2) synthase (PGES), respectively, and appear to mediate airway inflammation. OBJECTIVE: We sought to determine the role of PGDS and PGES in the pathophysiology of chronic rhinosinusitis (CRS). METHODS: The study examined the expression of PGDS and PGES in nasal polyps of 22 CRS patients. As controls, uncinate process mucosae were obtained from 12 CRS patients not having nasal polyps and five subjects without sinusitis. Immunohistochemistry and quantitative real-time PCR were used to evaluate the expression. RESULTS: Both PGDS and PGES were detected in nasal polyps by immunohistochemistry. Significantly greater levels of PGDS mRNA and lesser levels of PGES mRNA were observed in the nasal polyps as compared with uncinate process mucosae, and an inverse correlation between PGDS and PGES expression was observed. Levels of PGDS mRNA in nasal polyps were positively correlated with degree of infiltration by EG2+ eosinophils, whereas the levels of PGES were inversely correlated. Significantly increased levels of PGDS and conversely decreased levels of PGES were observed in asthmatics as compared with non-asthmatics. In addition, PGDS and PGES levels were positively and inversely correlated with the radiological severity of sinusitis, respectively. CONCLUSIONS: These results suggest that PGDS and PGES display an opposite and important role in the pathophysiology of CRS such as polyp formation, and more specifically, a biased expression of these synthases might contribute to the development of CRS by affecting eosinophilic inflammation.

Adolescent↗
PubMed2005

Nasal exposure to Staphylococcal enterotoxin enhances the development of allergic rhinitis in mice.

BACKGROUND: Staphylococcal enterotoxins (SEs) appear to play a role in the pathogenesis of allergic disease. However, little is known whether the nasal exposure to SE affects the development of allergic rhinitis (AR). OBJECTIVE: We sought to determine the in vivo effect of nasal exposure to SE on the development of AR using mouse model. METHODS: BALB/c mice were intranasally sensitized with Schistosoma mansoni egg antigen (SmEA) in the presence or absence of staphylococcal enterotoxin B (SEB). Control mice were intranasally sensitized with either SEB or SmEA alone. The production of antigen-specific antibodies including IgE, nasal eosinoplilia and cytokines by nasal mononuclear cells was compared among mice that had or had not received SEB treatment. RESULTS: Nasal exposure to SEB enhanced the development of AR in SmEA-sensitized mice, as manifested by SmEA-specific IgE production, nasal eosinophilia, and IL-4 and IL-5 production by nasal mononuclear cells after Ag challenge. This treatment also elicited IFN-gamma production by SmEA-primed cells. In addition, these mice produced SEB-specific IgE whereas mice treated with SEB without SmEA sensitization did not produce SEB-specific IgE or demonstrate nasal eosinophilia. CONCLUSION: These results suggest that the nasal exposure to SEB enhances susceptibility to AR although the exposure to SE solely does not induce AR.

Allergens↗
PubMed2005

Characterization of allergen-specific monocyte-derived dendritic cells generated from monocytes by a single-step procedure: effect on naïve and memory T cells.

BACKGROUND: Dendritic cells are one of the most potent antigen-presenting cells and when pulsed with allergen can modulate allergen-specific T-cell responses. We sought to establish a single-step method by which to generate allergen-specific monocyte-derived dendritic cells (MoDCs). METHODS: Dermatophagoides farinae (Df)-prepulsed MoDCs were generated from monocytes by culturing with Df in the presence interleukin (IL)-4, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumour necrosis factor (TNF)-alpha simultaneously. Df-prepulsed MoDC were incubated with autologous naive and memory T cells in the absence of recall antigen, then proliferation and cytokine production by T cells was determined. RESULTS: Generation of allergen-prepulsed MoDCs was confirmed by examining expression of surface molecules. Df-prepulsed MoDC selectively induced proliferation of Df-specific T cells in the absence of recall antigen. Under these conditions, Df-prepulsed MoDCs augmented but did not alter the cytokine production profile. In addition, Df-prepulsed MoDCs activated naive T cells leading to proliferation and selective production of IFN-gamma in allergic patients but not in healthy subjects. CONCLUSIONS: These results suggest that Df-prepulsed MoDC generated from monocytes by a simple single-step manipulation can induce Df-specific cellular responses from both naive and memory T cells in the absence of recall antigen, and these cells potentially can be utilized as immune adjuvants in allergen-specific immunotherapy.

Adult↗
PubMed2004

Xenogeneic embryonic stem cell-derived cardiomyocyte transplantation.

PURPOSE: The purpose of this study was to investigate the survival of xenogeneic embryonic stem cell (ES cell)-derived cardiomyocytes transplanted into the normal myocardium. MATERIAL AND METHODS: Undifferentiated mouse ES cells carrying the enhanced green fluorescent protein (EGFP) were cultured in hanging drops and then plated onto dishes. These cells were identified as cardiomyocytes by the expression of cardiac-specific genes, recording of action potential, and immunostaining with anti-sarcomeric myosin antibody. Donor cells were injected into the normal myocardium, with cyclosporine administered daily. One week after the transplantation, we investigated donor cell survival by examining EGFP expression, hematoxylin and eosin staining, and immunostaining with anti-sarcomeric myosin antibody. RESULTS: In vitro donor cells derived from ES cells expressed myosin light chain-2v and alpha-myosin heavy chain genes, had action potentials of a ventricular myocyte type, and were stained by anti-sarcomeric myosin antibody. In vivo 1 week after transplantation, EGFP-expressed cells were detected in the cell transplanted area. No lymphocytic infiltration was observed around these cells. CONCLUSIONS: ES cell-derived cardiomyocytes survived in the normal myocardium after the transplantation, even in a discordant xenogeneic transplantation model. These results indicate that cell transplantation using cardiomyocytes derived from ES cells, even if xenogeneic represents an attractive strategy for treating heart disease.

Action Potentials↗
PubMed2004

Relationship between immunological rejection and matrix GLA protein in cryopreserved vascular allografts.

INTRODUCTION: Cryopreserved tissue allografts used for cardiovascular diseases become calcified as a late complication after transplantation, probably caused by immunological rejection. Recent attention has been focused on the inhibitory effect of matrix Gla protein (MGP) on ectopic vascular calcification, but the behavior of MGP in cryopreserved allografts is uncertain. In this study we examined the relationship between immunological rejection and MGP in cryopreserved rat aortic grafts after transplantation. METHODS: Cryopreserved rat aortae were isografted or allografted intraperitoneally. Fresh isografts were also tested. The grafts were retrieved 9 days after transplantation and the intragraft MGP mRNA was measured by a real-time quantitative PCR method. The effect of daily administration of FK506 on MGP mRNA levels in cryopreserved isografts and allografts after transplantation was also evaluated. RESULTS: There was no significant difference in intragraft MGP mRNA levels between fresh and cryopreserved isografts 9 days after transplantation. MGP expression levels in cryopreserved allografts were significantly lower as compared to those in cryopreserved isografts (P < .01). Daily administration of FK506 enhanced intragraft MGP mRNA (ninefold) in cryopreserved allografts (P < .01), but not in cryopreserved isografts. CONCLUSIONS: Immunological rejection is likely to inhibit MGP expression in cryopreserved vascular allografts, resulting in late-onset calcification.

Animals↗
PubMed2004

Roles of major oligosaccharides on Cry j 1 in human immunoglobulin E and T cell responses.

BACKGROUND: We have demonstrated that carbohydrates in Cry j 1, the major allergen of Cryptomeria japonica pollen, play a major role in promoting Cry j 1-specific Th2 response. However, little is known as to whether the carbohydrates directly participate in allergic responses. OBJECTIVE: We sought to determine whether Cry j 1-related oligosaccharides function as IgE and/or T cell epitopes. In addition, the regulatory effect of Cry j 1-related oligosaccharide on Cry j 1-specific T cell responses was investigated. METHODS: Two monovalent oligosaccharides largely found on Cry j 1, Manalpha1-6(Manalpha1-3)(Xylbeta1-2)Manbeta1-4GlcNAcbeta1-4(Fucalpha1-3)GlcNAc (M3FX), and GlcNAcbeta1-2Manalpha1-6(GlcNAcbeta1-2Manalpha1-3)(Xylbeta1-2)Manbeta1-4GlcNAcbeta1-4(Fucalpha1-3)GlcNAc (GN2M3FX) were prepared. Manalpha1-2Manalpha1-6(Manalpha1-2Manalpha1-3)Manalpha1-6(Manalpha1-2Manalpha1-2Manalpha1-3)Manbeta1-4GlcNAcbeta1-4GlcNAc (M9A) was used as control. Competitive inhibition ELISA for Cry j 1-specific IgE was performed using these oligosaccharides as inhibitors. In addition, T cell lines specific for Cry j 1 or purified protein derivative of Mycobacterium tubecurosis (PPD) were established, and cellular responses against these oligosaccharides were investigated in the presence or absence of the respective antigens. RESULTS: Overall, neither M3FX nor GN2M3FX displayed inhibitory effect on the binding between IgE and Cry j 1. In addition, M3FX did not by itself stimulate Cry j 1 or PPD-specific T cells. However, M3FX significantly inhibited Cry j 1-induced proliferation and IL-4 production in Cry j 1-specific T cells. Such an inhibitory effect was not seen in PPD-specific T cell responses. CONCLUSION: These results suggest that Cry j 1-related oligosaccharides are not major epitopes for IgE or T cells. However, these oligosaccharides have a novel potential to inhibit Cry j 1-specific T cell responses selectively.

Adolescent↗
PubMed2003

Component analysis and growth process of nasopharyngeal calculus as revealed by Fourier transform infrared (FT-IR) spectroscopy.

A quite rare case of nasopharyngeal calculus in a woman in her twenties associated with the nasal discharge of pseudomonas infection was reported. As the substance was irregularly large in size, we extracted it partially by piecemeal resection using forceps and also by cracking technique using the holmium yttrium-aluminum-garnet (YAG) laser, under saline irrigation and stereotactic microscopic navigator (SMN) system under endoscopic observation. The substance was firmly fixed to the pharyngeal tonsil bed. The final extract was a small piece of singly folded bandage, which is probably the focal background for calculus formation. In a cross section of calculus specimen removed during surgery, Fourier transform infrared (FT-IR) analysis revealed that a) signal ratio of methylene group (organic substance) to amide I (protein) was 21.6% at the nasal cavity side, gradually decreased toward nasal mucous membrane showing approximate 50%, b) signal ratio of amide I to P04(3-) (inorganic substance) ranged between 17.7% and 26.7% at the different sites and inside the calculus, the protein content was approximate 1/5 of the inorganic substance, and c) signal ratio of the methylene group to amide I at the nasal cavity site showed that their contents were almost equal. The quantity of the organic substance was estimated at approximate 1/2 quantity of the protein at both the central part and the part contacted with the mucous membrane. From these results, it seems that throughout the course of calculus growth, both inorganic substance and protein remain almost constant inside the calculus, while organic substance is released from the internal part of the calculus being probably formed at an early stage.

Adult↗
PubMed2002

Carbohydrates expressed on Aspergillus fumigatus induce in vivo allergic Th2-type response.

BACKGROUND: The mould Aspergillus fumigatus (Af) causes several forms of Th2-biased diseases such as Type I respiratory allergies. This mould contains abundant carbohydrates including glucan, chitin and galactomannan. However, little is known on whether these carbohydrates directly drive Th2 responses in vivo. OBJECTIVE: We sought to determine the relative role of carbohydrates expressed on crude extracts of Af in the induction of Th2-type antibody production and local eosinophila in mice. METHODS: Carbohydrates on native Af were destroyed by sodium metaperiodate under mild conditions. CBA/J mice were sensitized intranasally with native, periodate-treated or mock-treated Af. Histologic changes and production of Af-specific IgE, IgG1 and IgG2a, as well as serum total IgE were determined. Inhibition ELISA for Af-specific IgE was performed using periodate-treated Af as an inhibitor. RESULTS: Mice sensitized with periodate-treated Af displayed significant decreases in both total and specific IgE levels in comparison to mice sensitized with native or mock-treated Af. Furthermore, sensitization and subsequent challenge with periodate-treated Af significantly reduced the degree of eosinophil recruitment into the nasal mucosa, compared to the controls. On the other hand, competitive inhibition showed that periodate-treated Af could inhibit binding between native Af and specific IgE in a similar manner to that of native and mock-treated Af. CONCLUSION: These results suggest that carbohydrates on Af play a key role as internal adjuvants in inducing the allergic Th2-type response and are not the targets of the induced IgE response.

Animals↗
PubMed2002

Intranasal application of purified protein derivative suppresses the initiation but not the exacerbation of allergic rhinitis in mice.

BACKGROUND: Several epidemiological and experimental studies have demonstrated that exposure to pathogens such as those from the genus Mycobacterium leads to the suppression of allergic sensitization and inflammation. However, little is known as to whether pathogen-derived soluble antigens have the potential to modulate the pathogenesis of allergic rhinitis. OBJECTIVE: We sought to determine whether application of purified protein derivative (PPD) from Mycobacterium tuberculosis can suppress the initiation and/or exacerbation of allergic rhinitis using a recently developed murine model. METHODS: First, we investigated whether a single intranasal application of PPD could elicit cytokine production in the nose by RT-PCR. BALB/c mice were repeatedly sensitized with Schistosoma mansoni egg antigen (SEA) intranasally without an adjuvant. PPD was applied through different routes either before or after sensitization. The production of SEA-specific antibodies, nasal eosinophilia and cytokines by nasal lymphocytes was compared among mice that had or had not received PPD treatment. RESULTS: IFN-gamma, but not IL-4, was detected in the nasal tissue 12 to 48 h after a single intranasal application of 10 microg PPD. Repeated intranasal application of PPD prior to and during sensitization with SEA significantly inhibited the production of both SEA-specific IgE/IgG1 and nasal eosinophilia. Moreover, it partially inhibited the production of IL-4 by nasal lymphocytes in response to SEA. Conversely, this treatment led to a significant increase in IFN-gamma production. On the other hand, PPD applied through the footpad had no effect over the same period. Repeated intranasal application of PPD after sensitization with SEA had no exacerbative effect on allergic inflammation. CONCLUSION: These results indicate that the local application of PPD, and the subsequent induction of IFN-gamma, inhibits the initiation, but not the exacerbation, of allergic rhinitis in mice. This suggests that pathogen-derived antigens have potential for use in the prevention and prophylaxis of allergic rhinitis.

Administration, Intranasal↗
PubMed2001

Ménière's disease in childhood.

We report 3 rare cases of Ménière's disease in children. In Case 1 and 3, vertigo, hearing loss and tinnitus recovered soon after medical therapy. In Case 2, however, vertigo recurred and the hearing level on the right side markedly deteriorated. The equal-loudness contours on three-dimensional audiogram showed that right-sided aggravated hearing loss fluctuated for 4 years at middle-and low-frequencies despite medication. Finally intratympanic injection of gentamicin sulfate was performed. The patient has had no definitive spell of vertigo after gentamicin therapy. At our department, the incidence of Ménière's disease in pediatric patients with vertigo was 2.9%.

Adolescent↗
PubMed2001

Quantification of TECTA and DFNA5 expression in the developing mouse cochlea.

TECTA and DFNA5 are the mouse orthologues of the human deafness-associated genes TECTA and DFNA5. To determine how expression of these genes is regulated during development, relative mRNA abundance was examined in mice by non-radioactive RT-PCR. TECTA mRNA was detected on embryonic day 15 (E15), increased to its highest level on postnatal day 3 (P3) and then dramatically decreased by P15. Low levels persisted (adulthood, P45 to 67) with mean mRNA abundance after P15 less than 25% of P3 levels. DFNA5 mRNA expression was constant throughout these time points. These results imply that TECTA is transcribed at a particularly high level during tectorial membrane morphogenesis. In contrast, DFNA5 is present in both the developing and mature cochlea.

Aging↗
PubMed2001

Differential role of CD80 and CD86 molecules in the induction and the effector phases of allergic rhinitis in mice.

Selective involvement of CD80 and/or CD86 in the differentiation of T-helper (Th)1 and Th2 was seen in several diseases. In this study, we sought to determine the differential roles of CD80 and CD86 in the induction and effector phase of allergic rhinitis using Schistosoma mansoni egg antigen (SEA) as a specific Ag. Intranasal sensitization with SEA in BALB/c mice elicited a strong Th2 response including SEA-specific IgE production, nasal eosinophilia, and IL-4 and IL-5 production by nasal lymphocytes after Ag challenge. Blockade of CD80 at the induction phase significantly inhibited these manifestations, whereas no effect was observed by CD86 blockade. In contrast, the simultaneous blockade of both CD80 and CD86 during the effector phase partially inhibited IgE and IgG(1) production and nasal eosinophilia, although either blockade of CD80 or CD86 during the phase failed to inhibit these responses. Flow cytometric analysis on nasal mononuclear cells showed that CD80 but not CD86 was preferentially expressed on non-B cells by in vitro SEA stimulation in unsensitized mice. However, both CD80 and CD86 expression were significantly augmented by in vitro SEA stimulation in sensitized mice. Our results suggest the differential roles and expression of CD80 and CD86 in the development of allergic rhinitis.

Animals↗
PubMed2001

Lacto-N-fucopentaose III found on Schistosoma mansoni egg antigens functions as adjuvant for proteins by inducing Th2-type response.

We have recently demonstrated that induction of Th2 responses by Schistosoma mansoni egg Ag is largely due to carbohydrates on the Ag functioning as adjuvants. Lacto-N-fucopentaose III (LNFPIII), a polylactosamine sugar, is the predominant carbohydrate found in S. mansoni egg Ag. Therefore, using neoglycoprotein, we investigated whether LNFPIII induces in vivo Th2 response and functions as an adjuvant. Following intranasal immunization with LNFPIII linked to human serum albumin (HSA) (HSA-LNFPIII), BALB/c mice mounted a strong Th2 response and produced significantly higher levels of total IgE as well as HSA-specific IgG, IgG1, and IgE. HSA-LNFPIII was over 1000-fold more potent in inducing Ab production as compared with HSA alone. Although LNFPIII itself did not function as an epitope for either IgG or IgE, its conjugation with protein was essential for the adjuvant activity. Moreover, fucose residue on LNFPIII was crucial for induction of Ab production. Nasal lymphocytes from mice immunized with HSA-LNFPIII produced IL-4, IL-5, and IL-10, but not IFN-gamma following in vitro stimulation with HSA or HSA-LNFPIII. In addition, these activated nasal lymphocytes also showed a significant increase of B7-2 expression on B220-positive cells. Furthermore, not only intranasal but also both i.p. and s.c. immunization with HSA-LNFPIII induced significant production of HSA-specific Abs compared with the immunization with HSA alone, suggesting that the activity of LNFPIII was not restricted on particular route of immunization. These results demonstrate that Lewis type carbohydrate LNFPIII can function as an adjuvant by their ability to induce a Th2 response.

Adjuvants, Immunologic↗
PubMed2001

Genomic structures of SCN2A and SCN3A - candidate genes for deafness at the DFNA16 locus.

DFNA16 is a form of autosomal dominant non-syndromic hearing loss (ADNSHL) characterized by fluctuating progressive hearing impairment. Earlier, we mapped the deafness-causing gene to chromosome 2q23-24.3. In this paper, we describe fine mapping results using additional markers tightly linked to the DFNA16 candidate region. Critical recombinants at markers D2S354 and D2S124 define a 3.5-cM interval that contains the DFNA16 gene. Positional candidate genes include two members of the voltage-gated sodium channel family, the type 2 alpha subunit (SCN2A) and the type 3 alpha subunit (SCN3A). After showing that SCN2A is expressed in human fetal cochlea, we determined its genomic structure to facilitate mutation screening in our DFNA16 kindred. We also determined the genomic structure of SCN3A. These two genes are oriented head-to-head, with their 5' ends separated by approximately 40 kb; their homology is 82% at the nucleotide level, and 85% for identities and 90% for positives at the amino acid level. They share similar genomic structures and have alternative splice isoforms that are developmentally regulated and highly conserved between species. Although no DFNA16-causing mutations were found in either gene, haplotype analysis with polymorphic markers in SCN2A introns further narrowed the candidate gene interval to the region flanked by D2S354 and STS SHGC-82894.

Alternative Splicing↗
PubMed2001

Random amplified polymorphic DNA analysis applied to acute otitis media caused by penicillin non-susceptible Streptococcus pneumoniae.

The spread of penicillin non-susceptible Streptococcus pneumoniae (PNSSP) is an emerging problem for the treatment of acute otitis media (AOM). Attendance of children at day care centers, as well as the spread of PNSSP, is a risk factor for AOM. The status of the spread of PNSSP during the acute infection phase of AOM has not been evaluated. We examined the clonality of samples from seven children in a day care center who simultaneously developed AOM caused by PNSSP. The seven isolates from the children, and six control samples were grouped by serotyping, by determining resistance to antimicrobial agents, and by genotyping, carried out by sequencer-based random amplified polymorphic DNA (RAPD), and validated by bootstrap analysis. There was no evidence to indicate the direct dissemination of PNSSP among these patients in the day care center, although the simultaneous occurrence of PNSSP AOM had initially suggested a clonal outbreak. The possible presence of a common ancestral strain suggested the importance of surveillance during the carrier state. The result of RAPD genotyping was highly reproducible, as validated by the high bootstrap score. The use of an automated sequencer, in combination with a careful choice of primers, and commercially established kits, played a significant role in the reproducibility of the studies.

Child↗
PubMed2001

Tracheal allotransplantation maintaining cartilage viability with long-term cryopreserved allografts.

BACKGROUND: Cartilage viability of a cryopreserved tracheal allograft seems to affect graft function and durability. We previously reported the influence of warm ischemia and cryopreservation on cartilage viability of tracheal allografts. For the clinical application of tracheal allotransplantation, it is essential to preserve grafts for a long time. In this study, we assessed cartilage viability of tracheal allografts after long-term cryopreservation in transplantation models. METHODS: The tracheas were harvested from Lewis rats. The grafts were frozen to -80 degrees C in a programmable freezer immediately after being harvested and were then stored in liquid nitrogen (-196 degrees C) for different lengths of preservation (1, 2, 6, 9, 12, 18, and 24 months; n for each group = 8). Cartilage viability was evaluated by estimating proteoglycan synthesis. After harvest or thawing of the tracheas, the cartilage was labeled with 4 muCi/mL of Na2 35SO4. Specimens were then hydrolyzed in 0.5 mol/L NaOH, and a solution of the extracts was then counted by a liquid scintillation counter. 35Sulfur incorporation before and after cryopreservation was examined in each group. Tracheal allotransplantation was performed using Lewis rats as donors and Brown Norway rats as recipients. RESULTS: The average 35S incorporation in the cartilage before cryopreservation was 224 +/- 17 disintegrations per minute per milligram of tissue protein. The average 35S incorporation in the cartilage after cryopreservation decreased to 67% to 76% compared with that before cryopreservation. There were no significant differences among the groups in 35S incorporations after cryopreservation. Histologic examination after transplantation revealed normal tracheal cartilage in all groups. CONCLUSIONS: The viability of tracheal cartilage after cryopreservation decreased to 67% to 76%. There were no significant differences in viability of cartilage among the tracheas after different lengths of cryopreservation. Tracheal allotransplantation after long-term cryopreservation can be safely performed in the rat model.

Animals↗