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Biomedical subjects

H Yasueda

Publications and source records attributed to H Yasueda.

At least 55 records · Page 3Linked to original sources

Sensitivity to two major allergens (Cry j I and Cry j II) in patients with Japanese cedar (Cryptomeria japonica) pollinosis.

BACKGROUND: Japanese cedar (Cryptmeria japonica: CJ) pollinosis is one of the most important allergic diseases in Japan. Recently, the second major allergen (Cry j II) was isolated from CJ pollen. There have been no prevalence studies of sensitivity to Cry j I and Cry j II among a large number of patients with pollinosis. OBJECTIVE: This study was conducted to evaluate the prevalence of sensitivity to Cry j I and Cry j II. We measured specific IgE antibodies to these allergens in the sera of 145 patients. Furthermore, comparison of the sensitivity to Cry j I and Cry j II was examined by the histamine release assay. METHODS: Specific IgE antibodies to Cry j I and Cry j II were assayed by a fluorometric ELISA. Allergen-specific histamine release was measured by a radioimmunoassay kit. RESULTS: More than 90% of 145 patients had specific IgE antibodies to both allergens, the remainder had specific IgE to either one or the other. There were seasonal changes in the level of specific IgE. The changes in the levels of anti-Cry j II IgE antibodies were parallel to those of anti-Cry j I IgE. The histamine release assay with leucocytes from the patients demonstrated that the allergenic potency of the two allergens is almost the same. CONCLUSION: Cry j II is an as important a major allergen as Cry j I.

Adult↗

IgE-mediated basophil releasability is influenced by intrinsic factors and by IgE on the cell surface.

Experiments were done to clarify the mechanisms associated with releasability of histamine. First, washed leukocytes from 23 asthmatic patients sensitive to mite allergen were challenged with Der p 1, a major allergen isolated from Dermatophagoides pteronyssinus, or anti-IgE. A significant correlation was observed between the ratio of Der p 1-specific IgE titer to total IgE level (S/T) in the patient's plasma and either the reactivity (maximal percentage of histamine release; rs = 0.514, P = 0.016, n = 23) or the sensitivity (the minimum allergen concentration required to achieve 25% histamine release; rs = -0.790, P = 0.0002) to Der p 1. Additionally, the reactivity to Der p 1 was significantly correlated with that to anti-IgE (rs = 0.690, P = 0.0012), indicating that an intrinsic cellular property may be one of the contributing factors in immunologic histamine release. In a second series of experiments, sinus mast cells were passively sensitized with immunoglobulins prepared from the patient's plasma. A statistically significant correlation was found between either the reactivity or the sensitivity to Der p 1 and S/T, thus indicating that S/T is an indicator of the releasability of histamine. When basophils or mast cells were passively sensitized with mouse IgE and subsequently stimulated with antimouse IgE, the reactivity to antihuman IgE was significantly correlated with that to antimouse IgE (rs = 0.966, P = 0.0023, n = 11). These observations suggest that an intrinsic cellular property regulates reactivity in immunologic histamine release. Taken together, our results suggest that an intrinsic cellular property, as well as specific IgE antibody levels on the cell surface, is an important factor in determining histamine release in response to IgE-dependent activation.

Adult↗

Control of ColE2 plasmid replication: negative regulation of the expression of the plasmid-specified initiator protein, Rep, at a posttranscriptional step.

The incA gene of ColE2 is involved in the copy number control and incompatibility. Two promoters were identified around the incA gene. Transcription of the mRNA for the essential plasmid-coded initiator protein (Rep) mainly starts at a site about 140 bp upstream of the initiation codon of the Rep protein. The second transcript (RNA I) of about 115 nucleotides with two stem-and-loop structures is entirely complementary to the 5' untranslated region of the Rep mRNA. By using translational and transcriptional fusions of the rep gene of ColE2 and the lacZ gene of Escherichia coli, the incA gene product was shown to regulate expression of the rep gene at a posttranscriptional step. The results also suggest that the target of the incA gene product is the 5' untranslated region of the Rep mRNA. Deletion analyses reported here show that a region(s) about 17 to 70 bp upstream of the initiation codon of the Rep protein and another region inside the coding frame are important for efficient production of the Rep protein. This suggests that some additional sequence elements other than the initiation codon and the Shine-Dalgarno region and/or a secondary structure of the Rep mRNA are required for efficient production of the Rep protein. These results show that RNA I is an antisense RNA for the Rep mRNA and imply that it might regulate expression of the rep gene at the initiation step of translation by sequestering such additional sequence elements and/or by disrupting RNA secondary structure. We propose that RNA I represents the incA gene product.

Bacterial Proteins↗

Control of ColE2 plasmid replication: regulation of Rep expression by a plasmid-coded antisense RNA.

We isolated and characterized mutants of ColE2 with increased copy number (cop) and those with reduced sensitivity to the wild-type incA gene (inc). Both types of mutations were single-base substitutions in the incA region and simultaneously increased the plasmid copy number and reduced the inhibitory activity of the incA gene on ColE2 DNA replication. Most of the cop mutations also reduced sensitivity to the wild-type incA gene. These mutations were located in the region specifying the large stem-and-loop structures of RNA I and the 5' portion of the Rep mRNA. All these results indicate that RNA I interacts with the Rep mRNA and thereby inhibits expression of the Rep protein at a post-transcriptional step and that this is probably the only mechanism that controls the ColE2 Rep protein expression. It is suggested that only portions of the nucleotides in the loop region are involved in initial (kissing) interaction of these RNAs. The total level of rep gene expression in the host cells appears to be kept constant (at a level characteristic for each cop allele) irrespective of the actual plasmid copy number above a certain level, when rep gene expression is regulated by the incA gene on the same plasmid. These seem to be the basic mechanisms for the replication control of ColE2.

Bacterial Proteins↗

Estimation of Der p and Der f I quantities in the reference preparations of Dermatophagoides mite extracts.

A monoclonal antibody-based enzyme-linked immunosorbent assay (MoAb-ELISA) was developed to measure the major Dermatophagoides mite allergens, Der p I and Der f I. The assay was highly species-specific and sensitive. Using this assay system, the absolute mass unit of Der p I and Der f I in the reference preparations of the extracts was estimated. The primary standards used were the purified Der p I and Der f I preparations. The reference preparations of the D. pteronyssinus and D. farinae extracts (92-Dp and 92-Df), which had been prepared from the same amount of mite bodies of both species, were found to contain the same levels of the Der I allergens, 10.1 micrograms/ml of Der p I and 10.0 micrograms/ml of Der f I, respectively. A histamine release assay with leucocytes from mite-allergic donors showed that the total allergenic potency of 92-Dp and 92-Df was comparable. This results indicates that the estimated Der I levels in these extracts seem to be valid, at least, in the balance between the two species, although further comparisons of the absolute quantities by several different laboratories are needed. The Der I levels in the WHO/IUIS international reference preparation of D. pteronyssinus and the CBER standard mite extracts, E4-Dp and E5-Df, were also estimated using this assay system. They were found to contain 4.4 micrograms/vial and 13.3 micrograms/ml of Der p I and 9.5 micrograms/ml of Der f I, respectively.

Allergens↗

Population analysis of cellular responses to synthetic peptides of Der p II, a major allergen molecule of Dermatophagoides pteronyssinus, in allergic and nonallergic subjects.

Responses of peripheral blood mononuclear cells to synthetic oligopeptides of Der p II, one of the major allergen molecules of Dermatophagoides pteronyssinus, were compared between allergic and nonallergic subjects. Healthy subjects showed positive responses to crude extracts of D. pteronyssinus, but only allergic subjects showed elevated cellular responses to Der p II. We synthesized three oligopeptides of Der p II in which motifs of a possible T-cell epitope were included. Of 14 subjects with positive response to Der p II, three responded to all three peptides, while five did not respond to any peptide tested. In 11 allergic patients who showed positive response to Der p II, responsiveness to the peptide K33-T47 was significantly higher than that to other peptides (P < 0.05). All the responding patients were also positive for scratch test to Der p II, suggesting that those epitopes induced IgE-promoting helper T-cell response in allergic persons. On the other hand, the in vitro cellular responses were not necessarily correlated to IgE production against Der p II in healthy subjects.

Adolescent↗

Atopic asthma caused by Candida albicans acid protease: case reports.

Two cases of atopic asthma caused by acid protease produced by Candida albicans are reported. Both patients had high levels of serum IgE antibodies against the acid protease and showed positive conjunctival and immediate bronchial responses when challenged with the protease. Significant histamine release was detected in both patients when their peripheral leukocytes were challenged with the protease antigen. These findings clearly showed that C. albicans acid protease is the causative allergen of atopic asthma.

Allergens↗

Allergen-specific human IgE helper T cell lines derived from patients allergic to Japanese cedar pollen.

To study the regulatory mechanism of allergen-dependent human IgE synthesis, Cry j I-specific and interleukin 4 (IL-4)-producing CD4+ T cell lines (SN-4 and SS-12) were established from 2 patients allergic to Japanese cedar pollen who highly expressed IL-4 mRNA in T cells in response to Cry j I stimulation. Upon stimulation of SN-4 and SS-12 cells with Cry j I, IL-4 production, which was observed at the protein and the mRNA levels, was induced in an HLA-DR-restricted manner, using autologous and allogeneic antigen-presenting cells. In addition to IL-4, not only considerable amounts of IL-5 and IL-6 but also very small amounts of IL-2 and interferon-gamma (IFN-gamma) were secreted by SN-4 and SS-12 cells, indicating that they fit into the Th2-like phenotype. The culture supernatant from Cry j I-activated SN-4 cells had the ability to induce IL-4-dependent IgE synthesis, CD23 expression and soluble CD23 release. Moreover, Cry j I-dependent IgE synthesis medated by SN-4 cells derived from 1 patient expressing HLA-DRw8, w9 could be specifically induced in both autologous and HLA-DRw9-matched allogeneic B cell cultures. This IgE induction was inhibited by neutralizing antibodies to IL-4, IL-5 and IL-6, but was not enhanced by anti-IFN-gamma antibody. On the other hand, neither IL-4 production nor IgE synthesis was induced when SN-4 cells were cocultured in the presence of Cry j I with HLA-DRw8-matched or histoincompatible allogeneic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Purification and characterization of a tissue-type transglutaminase from red sea bream (Pagrus major).

A tissue-type transglutaminase (TGase) was purified from liver tissue of the red sea bream, Pagrus major, by ion-exchange chromatography and heparin-Sepharose affinity chromatography. Its activity was assessed using a fluorometric assay to measure the incorporation of monodansylcadaverine into N,N'-dimethyl casein. The molecular mass of purified TGase was estimated to be 78 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme required Ca2+ to express its activity, although 10 mM Sr2+ also activated the enzyme fully. TGase activity was maximal at pH 9.0-9.5, and the enzyme was strongly inhibited by sulfhydryl reagents. The purified enzyme catalyzed the cross-linking of myosin heavy chain obtained from Alaska pollack, resulting in gelation of an actomyosin solution. The partial amino acid sequence of this fish TGase showed divisionally significant similarity to TGase from guinea pig liver.

Amino Acid Sequence↗

Removal of cat major allergen (Fel d I) from futon (Japanese bedding) with a home washing machine.

We evaluated the removal of a cat major allergen (Fel d I) from futons (Japanese bedding) with the use of a large-sized home washing machine. Before and after washing a futon that had been used in a home with a cat, a small amount of cotton was collected from the futon and Fel d I was extracted from the cotton. The levels of Fel d I were assayed by a sandwich enzyme-linked immunosorbent assay (ELISA). We found that washing reduced the Fel d I level in futons by more than 95%. In conclusion, washing of futons is an effective method for elimination of their cat allergens.

Allergens↗

Sensitization to cockroach allergens of asthma patients in Japan.

To evaluate the role of allergens from Periplaneta fuliginosa, which is the most predominant cockroach species in homes in Tokyo areas, for asthma sensitization, we measured specific IgE antibodies to two cockroaches, P. fuliginosa and Blattella germanica, and to a mite, Dermatophagoides farinae, in 171 sera from children with asthma by Pharmacia's CAP system. We found that 16% of the sera had anti-P. fuliginosa IgE, whereas 9.9% had anti-B. germanica and 85% anti-D. farinae IgE. Further, we measured the levels of Per f I (Per a I equivalent) allergen in the house dust from living room, kitchen and bedding. We detected the allergen in eight of ten homes. The Per a I equivalent levels in kitchen were higher than in other sites, but they were much lower than Der I and Der II as Dermatophagoides allergens.

Allergens↗

[Special cloth futon-cover (Miroguard) as a protection against house dust mite exposure].

We studied the efficacy of a special cloth encasing (Microguard) in protecting against house dust mite exposure. We vaccumed dust from right or left half surface of a shiki-futon (Japanese style mattress). Then we encased the shiki-futon by a new special encasing, vaccumed dust from the other part of the shiki-futon and got a pair of dust samples. We had done the same of the same shiki-futon by a used special encasing (used for one and half years) for about 2 weeks later. We prepared 7 shiki-futons and collected 14 pair dust samples. We weighed the dust and measured the mite allergens with a monoclonal antibody to Dermatophagoides pteronissynius and Dermatophagoides farinae. The dust level was 1.0% of the control (no encasing) in the new encasing group and 2.0% of the control in the used encasing group. The Der I concentration was 2.5 micrograms/(g dust) in the new encasing group and 3.2 micrograms/(g dust) in the used encasing group. The Der II concentration was 1.6 micrograms/(g dust). The total amount of Der I was 0.1% of the control in the new encasing group and 0.5% of the control in the used encasing group. The total amount of Der II was 0.2% of the control in the new encasing group and 0.7% of the control in the used encasing group. We compared Der p and Der f levels in the dust samples which we assayed and found no significant differences either in Der I or in Der II allergen. We concluded that Microguard was a useful tool to avoid mite allergen exposure by reducing not only the concentration of mite allergens but also the amount of dust.

Allergens↗

[Protracted (lasting) presence of Japanese cedar pollen allergen (Cry j I) in house dust].

We investigated the relationship between the amounts of Cry j I in house dust and airborne Cryptomeria japonica pollen in the same location. Cry j I was still detected in house dust collected two weeks after airborne C. japonica pollen had disappeared. Disappearance of Cry j I in house dust coincided with the disappearance of symptoms in the C. japonica pollinosis patients who lived in the same area. Airborne Cupressaceae pollen appeared during the latter half of the C. japonica pollen season. Disappearance of Cupressaceae pollen did not coincided with the disappearance of the symptoms in C. japonica pollinosis patients. Therefore, some symptoms of C. japonica pollinosis patients after C. japonica pollen disappeared from the air may be caused by pollen which had attached to clothes and been brought indoors.

Air Pollution, Indoor↗

Airborne cat (Fel d I), dog (Can f I), and mite (Der I and Der II) allergen levels in the homes of Japan.

We measured the airborne and floor dust allergen levels of the cat (Fel d I), dog (Can f I), and mite (Der I and Der II) allergens in 13 houses. Airborne allergens were sampled with a low-noise air sampler for 5 to 7 days in the living rooms where the inhabitants were living as usual. The mean levels of airborne Fel d I and Can f I in houses with cats or dogs were 5960 and 2880 pg/m3, respectively, which were about 160 and 100 times higher than levels of airborne Der I. In floor dust the mean levels of Fel d I and Can f I were 322 and 236 micrograms/gm fine dust, respectively, which were 59 and 10 times higher than the levels of Der I. These results suggest that the airborne cat and dog allergens might be important sources of allergens for persons who live in a house with those animals, because the absolute allergen levels in both the air and dust are significantly higher than those of mite.

Air↗

Allergens from Dermatophagoides mites with chymotryptic activity.

A new set of allergens from Dermatophagoides pteronyssinus and D. farinae (provisionally named DP5 and DF5, respectively) was isolated from the whole culture of mites. The apparent molecular weights of both allergens were shown to be 25,000 on SDS-PAGE under a reducing condition and 27,000 on Sephadex G-75 gel filtration chromatography. Both DP5 and DF5, as well as Der f III, possessed proteolytic activity. The results of substrate specificity and susceptibility to various protease inhibitors of DP5 and DF5 strongly suggested that they belonged to the chymotrypsin-like serine protease family. In sera from 88 mite-allergic patients, specific IgE antibodies to DP5 and/or DF5 were detected in only 41% of the sera by radio-allergosorbent test, while 90% and 93% had specific IgE antibodies to Der p I and/or Der f I and Der p II and/or Der f II, respectively.

Allergens↗

[The allergic reaction to acid protease released by Candida albicans].

The species of Candida albicans (C. albicans) are known to colonize mucocutaneous regions as part of the endogenous flora. C. albicans is also known as an important allergen in human allergic diseases. However, the major allergen of C. albicans has not been identified yet. Acid protease released from C. albicans (CAAP) cleaves IgA or the secretory component to enable C. albicans to colonize on the mucous membrane. In this study, using CAAP and crude Candida antigen as challenging antigens, we carried out conjunctival provocation tests (CPT) on 68 adult bronchial asthmatic patients who showed immediate positive skin reactions to crude Candida antigen. In several patients we performed serum IgE antibody (RAST), histamine release from peripheral leukocytes (HRT) and bronchial provocation tests (BPT) to CAAP. Six of the 8 patients who showed positive CPT to crude Candida antigen (75%) showed positive CPT responses to CAAP. On the other hand, only 1 of the 59 patients who showed negative CPT to crude Candida antigen (1.7%) showed positive CPT reactions to CAAP. Two female patients showed positive RAST and HRT to both crude Candida and CAAP. They also showed positive CPT and BPT. One patient had positive RAST results but negative HRT, CPT and BPT results. These results show that CAAP is an important allergen for atopic patients allergic to C. albicans.

Adult↗