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A Akasawa

Publications and source records attributed to A Akasawa.

At least 19 recordsLinked to original sources
PubMed2003

Analysis of gene expression in peripheral blood eosinophils from patients with atopic dermatitis and in vitro cytokine-stimulated blood eosinophils.

Investigation of differentially expressed genes in eosinophils of patients with allergic diseases such as atopic dermatitis (AD) will provide important information for elucidating possible mechanisms of pathology. To identify novel genes that are expressed in AD, we compared gene expression in samples of peripheral blood eosinophils from AD patients and healthy volunteers. RNA was extracted from peripheral blood eosinophils. The expression of various genes, such as those for cytokine receptors, eosinophil activation marker, platelet activating factor (PAF) receptor, eosinophil-specific granular proteins and apoptosis-related genes, was confirmed using real-time reverse transcription-polymerase chain reaction (RT-PCR). Peripheral blood eosinophils of healthy volunteers were also isolated and stimulated for introduction of various cytokines. RNA was extracted and gene expression was monitored. Several genes, such as those for cytokine receptors (granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor alpha and beta chain and interleukin (IL)-3 receptor alpha chain), CD44 and PAF receptor were expressed at significantly higher levels in AD patients than in healthy volunteers. In addition, the anti-apoptotic genes, bcl-2 and bcl-xL, were expressed at increased levels in AD patients. No single gene expression correlated with clinical markers, such as eosinophil count or IgE levels. Expression of GM-CSF receptor beta chain and IL-3 receptor alpha chain in isolated blood eosinophils of healthy volunteers was stimulated by IL-5, IL-4, interferon (IFN)-gamma and GM-CSF. Expression of bcl-2 and bcl-xL was also increased after stimulation with IL-5, IL-4 or IFN-gamma. The in vitro enhancement of cytokine-stimulated gene expression correlated well with the enhancement observed in clinical samples of eosinophils, suggesting that cytokines may affect gene expression in vivo in eosinophils of patients with AD.

Adolescent↗
PubMed2001

Gene expression screening of human mast cells and eosinophils using high-density oligonucleotide probe arrays: abundant expression of major basic protein in mast cells.

Mast cells (MCs) and eosinophils are thought to play important roles in evoking allergic inflammation. Cell-type--specific gene expression was screened among 12,000 genes in human MCs and eosinophils with the use of high-density oligonucleotide probe arrays. In comparison with other leukocytes, MCs expressed 140 cell-type--specific transcripts, whereas eosinophils expressed only 34. Among the transcripts for expected MC-specific proteins such as tryptase, major basic protein (MBP), which had been thought to be eosinophil specific, was ranked fourth in terms of amounts of increased MC-specific messenger RNA. Mature eosinophils were almost lacking this transcript. MCs obtained from 4 different sources (ie, lung, skin, adult peripheral blood progenitor--derived and cord blood progenitor--derived MCs, and eosinophils) were found to have high protein levels of MBP in their granules with the use of flow cytometric and confocal laser scanning microscopic analyses. The present finding that MCs can produce abundant MBP is crucial because many reports regarding allergic pathogenesis have been based on earlier findings that MBP was almost unique to eosinophils and not produced by MCs. (Blood. 2001;98:1127-1134)

Adult↗
PubMed2001

Selective down-regulation of high-affinity IgE receptor (FcepsilonRI) alpha-chain messenger RNA among transcriptome in cord blood-derived versus adult peripheral blood-derived cultured human mast cells.

Substantial numbers of human mast cells (MCs) were generated from umbilical cord blood (CB) and from adult peripheral blood (PB). A single CB progenitor produced 15 436 MCs, whereas a single PB progenitor produced 807 MCs on average. However, PB-derived MCs were far more active than CB-derived MCs in terms of high-affinity IgE receptor (FcepsilonRI)-mediated reactions. One million sensitized PB-derived MCs released 3.6 microg histamine, 215 pg IL-5, and 14 ng granulocyte macrophage-colony-stimulating factor (GM-CSF), whereas 10(6) sensitized CB-derived MCs released only 0.8 microg histamine, 31 pg IL-5, and 0.58 ng GM-CSF on anti-IgE challenge. However, ionophore A23 187 released similar levels of histamine from the 2 MC types. PB-derived MCs highly expressed surface FcepsilonRI alpha chain, and CB-derived MCs almost lacked it in the absence of IgE. PB-derived MCs expressed approximately 5 times higher levels of messenger RNA (mRNA) for FcepsilonRI alpha chain than CB-derived MCs, but mRNAs for beta and gamma chains of the receptors were equally expressed. Among the approximately 5600 kinds of full-length human genes examined by using the high-density oligonucleotide probe-array system, FcepsilonRIalpha was ranked the fifth most increased transcript in PB-derived MCs. The 4 other increased transcripts were unrelated to MC function. These results suggest that IgE-mediated reactions may be restricted during early infancy through the selective inhibition of FcepsilonRIalpha transcription, which is probably committed at progenitor stages and is, at least in part, cytokine-insensitive.

Adult↗
PubMed2001

Psychosocial factors and adherence to treatment advice in childhood atopic dermatitis.

Poor adherence to maintenance treatment for atopic dermatitis and anxiety about using topical steroids are common features seen among children with atopic dermatitis and their mothers. No systematic study exploring factors associated with adherence to treatment advice on atopic dermatitis has been carried out to date. This study seeks to generate hypotheses regarding the relationship between a range of psychosocial factors and adherence to treatment advice on atopic dermatitis. An anonymous self-completed questionnaire containing adherence items, psychosocial items, some demographic items, and attitudes to steroid use was given to 258 mothers of atopic dermatitis follow-up patients who attended the National Children's Hospital, Tokyo. Responses from 205 families (80%) with complete data were then analyzed to explore the correlation between each factor and to build a structure equation model. The strongest predictor of adherence to skin-care treatment was a good doctor-patient (mother) relationship, followed by the severity of the disease as perceived by the mother. Surprisingly, the mother's anxiety about using topical steroids had no significant influence on reported use of topical steroids nor on adherence to skin-care treatment. This may have been overcome by the well-established doctor-patient (mother) relationship. Maternal personality, husband's cooperation, and social support were indirectly correlated with adherence via the doctor-patient relationship. Maternal self-efficacy of treatment was strengthened by good doctor-patient (mother) relationship.

Adolescent↗
PubMed2001

Human mast cell progenitors in peripheral blood from atopic subjects with high IgE levels.

BACKGROUND: It remains unclear whether the number of circulating mast cell progenitors is increased in patients with atopic diseases. Distinct genotypes are reported to affect mast cell/basophil activation. OBJECTIVE: We compared the number and function of mast cell progenitors present in the peripheral blood from donors with normal IgE (IgE < 400 U/mL) and those with atopic dermatitis accompanied by high serum IgE (IgE > 5000 U/mL). METHODS: Purified peripheral blood cells were cultured in serum-free methylcellulose containing stem cell factor (SCF), IL-6 plus IL-3. Fresh methylcellulose containing the cytokines was layered over every 2 weeks. The cultured mast cells were retrieved from the methylcellulose and were functionally analysed. RESULTS: Mast cell colonies were distinguished at 6 weeks of culture as other colony types had been degenerated. The number of mast cell colony-forming cells varied depending on donors and was not significantly increased in peripheral blood from the hyper-IgE atopic patients. A significant inversed correlation was found between the number of mast cells per one colony and the ages of donors. The cultured mast cells derived from atopic patients and those from normal IgE donors equally expressed Fc epsilon RI and released histamine through Fc epsilon RI, although IL-4 priming in vitro markedly enhanced the function of mast cells regardless of donors. CONCLUSIONS: These results indicate that the number of circulating mast cell progenitors may be regulated by unknown individual factors unrelated to IgE levels. Mast cell function may be regulated largely by environmental factors, such as IL-4, but not determined by their progenitors' genotypes.

Adolescent↗
PubMed2001

Gene expression accompanied by differentiation of cord blood-derived CD34+ cells to eosinophils.

To clarify the relation between the expression of genes such as eosinophil-specific granular proteins and cytokine receptors and the pathogenesis of allergic disease, cord blood-derived CD34+ cells were cultured and differentiated into eosinophils. Gene expression in the cells during the differentiation was determined by real-time reverse transcription PCR (ABI PRISM 7700). CD34+ mononuclear cells cultured with stem cell factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, and IL-5 in Iscove's MEM, and proliferated until the 2nd week, when the cell number reached a plateau. Under these conditions, more than 90% of the cells differentiate into mature eosinophils in 3 weeks. The expression of major basic protein and eosinophil-derived neurotoxin in the treated cells increased until week 2 and decreased between week 2 and 3. However, the expression of membrane receptor genes, such as IL-5 receptor (alpha chain), IL-3 receptor (alpha chain), GM-CSF-alpha receptor, GM-CSF-beta receptor, CC chemokine receptor 3, interferon-gamma receptor, platelet-activating factor receptor and leukotriene D4 receptor, increased until the 3rd week of eosinophil maturation. Our study suggests that the in vitro eosinophil differentiation and maturation model is useful for clarifying the relation between eosinophil-specific gene expression during allergic diseases and the progression of the disease.

Antigens, CD34↗
PubMed2000

Adrenocortical function in patients with severe atopic dermatitis.

BACKGROUND: Adrenocortical suppression is a potential complication of the use of topical corticosteroids in patients with atopic dermatitis (AD). OBJECTIVES: To determine whether or not the adrenocortical suppression observed in patients with severe AD is a sole result of the application of topical steroids. METHODS: A total of 45 patients with severe AD that required hospitalization for treatment were enrolled. These patients were divided into two groups according to the treatment received before hospitalization: group 1 had not used topical corticosteroids for at least three months (n = 17), while group 2 had used topical corticosteroids daily (n = 28). Otherwise, these two groups were matched to clinical characteristics. A rapid ACTH test was performed upon hospital admission. Topical corticosteroids were then applied to both groups. The second ACTH test was performed just before discharge, an average of 23 days after the first test. RESULTS: The basal serum cortisol levels as well as the response to ACTH stimulation in the first examination were significantly lower in the AD patients than in the controls (P < .001), although there were no significant differences in the results between groups 1 and 2. The followup study of adrenocortical function at hospital discharge showed that morning basal serum cortisol levels were significantly increased in group 1 (P < .01), despite their topical corticosteroid treatment, while no significant increase or decrease was seen in group 2. CONCLUSION: Our findings suggest that the adrenocortical suppression seen in patients with AD may be caused by the percutaneous absorption of topical corticosteroids as well as by other factors related to the disease.

Administration, Topical↗
PubMed2000

Regulation of chymase production in human mast cell progenitors.

BACKGROUND: Although mature tryptase-positive mast cells (MCs) and tryptase and chymase double-positive MCs are recognized using in situ staining and are preferentially distributed in different tissues, recent findings suggest that tryptase-positive MCs can give rise to tryptase and chymase double-positive MCs. OBJECTIVE: We investigated the regulation of chymase production in developing MCs. METHODS: Human cord blood or peripheral blood cells were cultured in the presence of stem cell factor and IL-6 with or without IL-4 in methylcellulose or liquid medium. Intracellular chymase and tryptase were determined with immunocytochemistry, flow cytometry, and ELISA. Chymase messenger RNA expression was examined with 3 different methods, such as Northern blotting. RESULTS: Flow cytometric analysis always showed a unimodal histogram of chymase-positive, as well as tryptase-positive, cells in the presence of various cytokines, even when chymase was not detected in some MCs with immunocytochemistry. The chymase protein expression increased by culture duration and was enhanced by cytokines, such as a high concentration of stem cell factor or IL-4. Chymase messenger RNA was expressed higher in immature MCs than mature chymase protein-rich MCs. We generated macroscopic MC colonies in methylcellulose by culturing CD34(+) cells for 10 weeks and measured cellular chymase, tryptase, and histamine. The chymase/histamine ratio widely varied (0.07-1.01) depending on MC colony, even under the same culture conditions, including IL-4, whereas the tryptase/histamine ratio was relatively constant (1.02-1.89). CONCLUSION: All human MCs in culture are capable of producing chymase, and the production is clonally regulated at their progenitors by cytokine-independent mechanisms, as well as being totally controlled by cytokine-dependent mechanisms accompanied by maturation.

Cells, Cultured↗
PubMed2000

[Latex allergy].

Explore the source record for details and available documents.

Allergens↗
PubMed1999

Characterization of mast cell-committed progenitors present in human umbilical cord blood.

Human mast cells are derived from CD34(+) hematopoietic cells present in cord blood, bone marrow, and peripheral blood. However, little is known about the properties of the CD34(+) cells. We demonstrated here that mast cell progenitors that have distinct phenotypes from other hematopoietic cell types are present in cord blood by culturing single, sorted CD34(+) cells in 96-well plates or unsorted cells in methylcellulose. The CD34(+) mast cell-committed progenitors often expressed CD38 and often lacked HLA-DR, whereas CD34(+) erythroid progenitors often expressed both CD38 and HLA-DR and CD34(+) granulocyte-macrophage progenitors often had CD33 and sometimes expressed CD38. We then cultured single cord blood-derived CD34(+)CD38(+) cells under conditions optimal for mast cells and three types of myeloid cells, ie, basophils, eosinophils, and macrophages. Of 1,200 CD34(+)CD38(+) cells, we were able to detect 13 pure mast cell colonies and 52 pure colonies consisting of either one of these three myeloid cell types. We found 17 colonies consisting of two of the three myeloid cell types, whereas only one colony consisted of mast cells and another cell type. These results indicate that human mast cells develop from progenitors that have unique phenotypes and that committed mast cell progenitors develop from multipotent hematopoietic cells through a pathway distinct from myeloid lineages including basophils, which have many similarities to mast cells.

ADP-ribosyl Cyclase↗
PubMed1999

Evaluation of the staphylococcal exotoxins and their specific IgE in childhood atopic dermatitis.

BACKGROUND: Superantigenic exotoxins produced by Staphylococcus aureus and their specific IgE antibodies are thought to be important precipitating factors of atopic dermatitis (AD), but there are few reports evaluating these 2 factors at the same time. OBJECTIVE: We examined whether the presence of the exotoxins sampled from the skin of patients with AD and the levels of anti-exotoxin IgE antibodies in their sera correlated with their severity of AD. METHODS: Patients with mild-to-severe AD, 1 to 22 years of age, were evaluated by using Leicester's scoring system. Specific IgE antibodies against these exotoxins were determined by using ELISA. S aureus was isolated from 3 different areas of the skin. We examined whether the exotoxin (staphylococcal enterotoxin [SE]A, SEB, SEC, SED, and toxic shock syndrome toxin-1) could be detected. RESULTS: The levels of SEB-specific IgE were correlated with the severity of AD. Five of 6 patients having very high SEB-specific IgE antibody titers were under 6 years of age, and SEB was most frequently isolated (41%). There was no difference in severity between patients with or without exotoxin-producing S aureus. The severity of 9 patients who had both exotoxin-producing S aureus on the skin and specific IgE antibody against the same exotoxin in sera was significantly higher than that of the other patients. CONCLUSIONS: Anti-SEB IgE titers correlate well with the severity of AD. The presence of exotoxin-producing S aureus may precipitate AD through its specific IgE antibody.

Adolescent↗
PubMed1998

Identification and cloning of prs a 1, a 32-kDa endochitinase and major allergen of avocado, and its expression in the yeast Pichia pastoris.

Avocado, the fruit of the tropical tree Persea americana, is a source of allergens that can elicit diverse IgE-mediated reactions including anaphylaxis in sensitized individuals. We characterized a 32-kDa major avocado allergen, Prs a 1, which is recognized by 15 out of 20 avocado- and/or latex-allergic patients. Natural Prs a 1 was purified, and its N-terminal and two tryptic peptide sequences were determined. We isolated the Prs a 1 encoding cDNA by PCR using degenerate primers and 5'-rapid amplification of cDNA ends. The Prs a 1 cDNA coded for an endochitinase of 326 amino acids with a leader peptide of 25 amino acids. We expressed Prs a 1 in the yeast Pichia pastoris at 50 mg/liter of culture medium. The recombinant Prs a 1 showed endochitinase activity, inhibited growth and branching of Fusarium oxysporum hyphae, and possessed IgE binding capacity. IgE cross-reactivity with latex proteins including a 20-kDa allergen, most likely prohevein, was demonstrated, providing an explanation for the commonly observed cross-sensitization between avocado and latex proteins. Sequence comparison showed that Prs a 1 and prohevein had 70% similarity in their chitin-binding domains. Characterization of chitinases as allergens has implications for engineering transgenic crops with increased levels of chitinases.

Allergens↗
PubMed1998

Plant defense-related enzymes as latex antigens.

BACKGROUND: Latex allergy is an increasing hazard to people who frequently come into contact with latex products. Of interest concerning this immediate-type allergy is the cross-reactivity to various vegetable foods and pollen. Despite its high prevalence, no adequate explanation has been provided for the cross-reactive antigens. OBJECTIVE: We have hypothesized that a series of plant defense-related proteins act as latex allergens, as well as vegetable food allergens. To evaluate this hypothesis, hydrolytic enzymes that are very likely to take on defensive roles in rubber trees were examined for their antigenicity. METHODS: By applying chromatographic procedures, defense-related enzymes were separated from nonammoniated latex (NAL). Their antigenicity was examined by immunoblotting and ELISA with sera containing IgE antibodies to crude latex proteins. RESULTS: Three kinds of hydrolytic enzymes (basic beta-1,3-glucanases [35, 36.5, and 38 kd], a basic chitinase/lysozyme [29.5 kd], and an acidic esterase [44 kd]) were separated from NAL. They were recognized by IgE antibodies from a significant number of patients allergic to latex. The basic beta-1,3-glucanases and the acidic esterase were also strongly recognized by IgE antibodies from several atopic subjects who were allergic to various vegetable foods rather than latex products. CONCLUSION: It was ascertained that the three defense-related enzymes separated from NAL constituted part of the latex antigens. Taking together the well-known serologic or immunologic relationships and amino acid sequence similarities of defense-related proteins coming from phylogenetically distant plant species, we can suspect their universal antigenicity and cross-reactivity.

Chitinases↗
PubMed1998

[Safe administration of influenza vaccine in asthmatic children].

Thirty asthmatic children were examined allergic reaction against egg white, gelatin and vaccine solution before and after vaccination using skin prick test. We also measured the levels of specific IgE and IgG antibody against gelatin. The changes in clinical symptoms before and after vaccination were investigated in 25 asthmatic children by evaluating symptom and treatment score. The results were as follows; 1. In one subject who had delayed type of skin reaction to gelatin, the adverse reaction was also recognized at the skin site around 24 hrs after vaccination. In this subject, the levels of serum specific IgE and IgG to gelatin became positive after 5 months. 2. Specific IgE antibodies to gelatin were not detected in all subjects before and after vaccination. 3. The mean values of asthma symptom score before and after vaccination were 3.3 +/- 4.2 and 1.5 +/- 3.3 respectively. Those of treatment score before and after vaccination were 75.6 +/- 35.2 and 76.0 +/- 35.0 respectively. These results suggest that skin testing with gelatin and vaccine solution is useful as a screening method for predicting adverse reactions in asthmatic children and that influenza vaccination can be performed safely in skin test negative children.

Asthma↗
PubMed1997

Cold stimulation test and histamine release in primary acquired cold urticaria.

The patient was a 10-year-old boy who complained of urticaria upon exposure to cold air and after swimming in the pool. He also had seasonal asthma and wheezing after strenuous activities. To determine whether he had primary acquired cold urticaria, we performed a cold stimulation test twice. We likewise wanted to know whether a difference in response with regard to histamine release existed between blood samples taken from the challenged and the unchallenged sites. We obtained blood samples for histamine release initially at the site opposite the challenged forearm, and then on the same side on two separate occasions. We noted the appearance of constitutional signs and symptoms and correlated the time of their appearance with the result of histamine levels. The patient complained of pruritus and wheals appeared at the 5 minute in both tests. Results of plasma histamine release in the two measurements showed the highest releasability at 15 min. Our findings revealed that histamine is released systemically in response to cold stimulation regardless of the site where the blood sample was obtained.

Asthma↗
PubMed1997

RANTES production in a conjunctival epithelial cell line.

PURPOSE: Although corneal tissue damage in allergic ocular diseases is thought to be induced by inflammatory cells that infiltrate from conjunctival tissue, the mechanisms of recruiting these cells remain unclear. The objective of this study was to demonstrate whether conjunctival epithelial cells have the ability to produce "regulated on activation, normal T-cell expressed and secreted" (RANTES). To test this hypothesis, we investigated RANTES expression in the conjunctival tissue and also RANTES production by cytokine stimulation in a human conjunctival epithelial cell line. METHODS: We investigated the expression of the chemokine RANTES in conjunctival epithelium from two patients with atopic keratoconjunctivitis (AKC) and one patient with vernal keratoconjunctivitis (VKC) by using immunohistochemistry. We also investigated the production and suppression of RANTES from a human conjunctival epithelial cell line, Wong-Kilbourne-derived human conjunctiva (WK-hC) by using enzyme-linked immunosorbent assay (ELISA). RESULTS: Conjunctival epithelium from a patient with AKC stained positively for RANTES. We found that tumor necrosis factor-alpha (TNF-alpha) induced de novo production of RANTES, and interferon-gamma (IFN-gamma) synergistically increased the TNF-alpha-dependent production of RANTES from WK-hC cells. Dexamethasone suppressed the RANTES production from the cell line. CONCLUSION: Taken together, human conjunctival epithelial cells were capable of producing RANTES in response to inflammatory stimuli such as TNF-alpha and may play a role in recruiting inflammatory cells such as eosinophils and T lymphocytes toward the ocular surface.

Adolescent↗