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Biomedical subjects

Toshio Miyawaki

Publications and source records attributed to Toshio Miyawaki.

At least 19 recordsLinked to original sources
PubMed2006

MxA-based recognition of viral illness in febrile children by a whole blood assay.

Febrile children are often given antibiotics empirically and unnecessarily. MxA is a protein induced in peripheral lymphoid cells by type 1 interferons during active viral infection. The ability of a whole blood ELISA assay for MxA to identify children with viral illness was studied in 122 children who presented with acute onset fever and 52 age-matched healthy controls. The febrile children were divided into three groups according to their final diagnoses: etiologically diagnosed viral infection, clinically diagnosed viral infection, and bacterial infection. MxA levels in the bacterial infection group and controls were similar and low (90.9 +/- 69.7 and 76.9 +/- 63.2 ng/mL, respectively). In contrast, mean MxA levels in the two viral infection groups were higher than in both the bacterial and control groups (719.2 +/- 386.4 and 827.0 +/- 651.1, respectively). A receiver operating characteristic analysis showed that the area under the curve of the MxA level was greater than under the curves of both the white blood cell count and the C-reactive protein concentration. Whole blood assay of MxA is a clinically useful tool for diagnosing viral illness in febrile children and should help reduce use of unnecessary antibiotics.

Adolescent↗
PubMed2006

Clinical, immunological and molecular characteristics of 37 Iranian patients with X-linked agammaglobulinemia.

BACKGROUND: X-linked agammaglobulinemia (XLA) is a hereditary immunodeficiency characterized by an early onset of recurrent bacterial infections, a profound deficiency of all immunoglobulin isotypes and a markedly reduced number of peripheral B lymphocytes. Eighty-five percent of the patients with this phenotype have mutations in Bruton's tyrosine kinase (BTK) gene. METHODS: To provide an informative outlook of clinical and immunological manifestations of XLA in Iran, 37 Iranian male patients with an age range of 1-34 years, followed over a period of 25 years, were studied. Twenty-four of the 37 patients were screened for BTK gene mutation using PCR-SSCP followed by direct sequencing. BTK protein expression assay was done by flow cytometry in 9 families. RESULTS: All patients first presented with infectious diseases, the most common of which were respiratory tract infections. Eighteen different mutations were identified, 13 of which were novel: IVS1+5G>C, 1896G>A, 349delA, 1618C>T, 1783T>C, 2084A>G, 1346delT, 1351delGAG, 587A>G, IVS14-1G>A, IVS3+2T>C, 1482G>A, 1975C>A. CONCLUSION: The fact that we found a great number of novel mutations in a relatively limited number of patients underlines the heterogeneity of BTK mutations in the Iranian population. The large number of new mutations indicates that extended studies in this region would be rewarding.

Adolescent↗
PubMed2006

Expression of myeloid-related protein-8 and -14 in patients with acute Kawasaki disease.

OBJECTIVES: This study investigated patients with acute Kawasaki disease (KD) to validate myeloid-related protein (MRP)-8/MRP-14 as a marker of disease activity and severity of coronary artery lesion development. BACKGROUND: Both MRP-8 and -14, which are S100-proteins secreted by activated neutrophils and monocytes, bind specifically to endothelial cells and induce thrombogenic and inflammatory responses in a variety of disease conditions. METHODS: We investigated 61 patients with acute KD and examined sequential changes in serum levels of MRP-8/MRP-14, messenger ribonucleic acid (mRNA) expression of MRP-8 and -14 in circulating granulocytes and monocytes, and amounts of MRP-8/MRP-14 bound to circulating endothelial cells. RESULTS: The serum MRP-8/MRP-14 levels as well as mRNA expressions of MRP-8 and -14 in granulocytes were strongly upregulated during the early stage of acute KD, and decreased dramatically within 24 h of intravenous immune globulin therapy (p < 0.05) in 45 responders. In contrast, in 16 nonresponders both of these increased after the initial treatment. The number of MRP-8/MRP-14-positive circulating endothelial cells was higher in patients with acute KD than in control patients and increased significantly by 2 weeks after the onset of KD, especially in patients in whom coronary artery lesions developed. CONCLUSIONS: We show for the first time that MRP-8/MRP-14 are exclusively secreted by granulocytes in patients with acute KD, and intravenous immune globulin treatment suppresses their gene expression. Serum levels of MRP-8/MRP-14 may be useful markers of disease activity, and the levels of MRP-8/MRP-14-positive circulating endothelial cell may predict the severity of vasculitis, confirming an important role for distinct inflammatory reactions in endothelium.

Acute Disease↗
PubMed2006

Genetic analysis in patients with left ventricular noncompaction and evidence for genetic heterogeneity.

Left ventricular noncompaction (LVNC) is a cardiomyopathy characterized by numerous excessively trabeculations and deep intertrabecular recesses. This study was performed to investigate Japanese LVNC patients for disease-causing mutations in a series of selected candidate genes. DNA was isolated from the peripheral blood of 79 cases including 20 familial cases and 59 sporadic cases. DNA samples were screened for mutations in the genes encoding G4.5 (TAZ), alpha-dystrobrevin (DTNA), alpha1-syntrophin (SNTA1), FK506 Binding protein 1A (FKBP1A or FKPB12: FKBP1A), and LIM Domain Binding protein 3 (Cypher/ZASP: LDB3), using single-strand conformational polymorphism analysis and DNA sequencing. DNA variants were identified in 6 of the 79 cases, including four familial cases and two sporadic cases. A splice acceptor mutation of intron 8 in TAZ (IVS8-1G>C) was identified in one family with isolated LVNC, resulting in deletion of exon 9 from mRNA. In a sporadic case of isolated LVNC and Barth syndrome (BTHS), a 158insC in exon 2 of TAZ resulting in a frame-shift mutation was identified. A 1876G>A substitution changing an aspartic acid to asparagine (D626N) was identified in LDB3 in four members of two families with LVNC. A 163G>A polymorphism was identified in LDB3, which changed a valine to isoleucine (V55I) in one patient with isolated LVNC. In addition, in a family with nonisolated LVNC, a 362C>T mutation was identified in DTNA. LVNC, like other forms of inherited cardiomyopathy, is a genetically heterogeneous disease, associated with variable clinical symptoms and can be inherited as an autosomal or X-linked recessive disorder.

Acyltransferases↗
PubMed2006

Human tyrosine kinase 2 deficiency reveals its requisite roles in multiple cytokine signals involved in innate and acquired immunity.

Tyrosine kinase 2 (Tyk2) is a nonreceptor tyrosine kinase that belongs to the Janus kinase (Jak) family. Here we identified a homozygous Tyk2 mutation in a patient who had been clinically diagnosed with hyper-IgE syndrome. This patient showed unusual susceptibility to various microorganisms including virus, fungi, and mycobacteria and suffered from atopic dermatitis with elevated serum IgE. The patient's cells displayed defects in multiple cytokine signaling pathways including those for type I interferon (IFN), interleukin (IL)-6, IL-10, IL-12, and IL-23. The cytokine signals were successfully restored by transducing the intact Tyk2 gene. Thus, the Tyk2 deficiency is likely to account for the patient's complex clinical manifestations, including the phenotype of impaired T helper 1 (Th1) differentiation and accelerated Th2 differentiation. This study identifies human Tyk2 deficiency and demonstrates that Tyk2 plays obligatory roles in multiple cytokine signals involved in innate and acquired immunity of humans, which differs substantially from Tyk2 function in mice.

Adolescent↗
PubMed2006

Outcome in patients with Wiskott-Aldrich syndrome following stem cell transplantation: an analysis of 57 patients in Japan.

A total of 57 patients with Wiskott-Aldrich syndrome (WAS) were studied after undergoing stem cell transplantation (SCT) in Japan between January 1985 and December 2004. Eleven patients received transplants from human leucocyte antigen (HLA)-matched related donors, 10 from HLA-mismatched related donors, 21 from unrelated bone marrow donors, and 15 from unrelated cord blood donors. Nine of the 57 patients rejected the initial graft. The overall 5-year survival rate was 73.7% and the 5-year failure-free survival rate was 65.7% (failure was defined as rejection or death). The overall 5-year survival rates for patients receiving bone marrow and cord blood from unrelated donors were both 80.0%. Based on univariate analysis, the factors associated with poor survival were: transplantation from an HLA-mismatched related donor, patient age of more than 5 years at the time of transplantation, and a conditioning regimen other than busulfan and cyclophosphamide (BU-CY) or busulfan, cyclophosphamide and antithymocyte globulin (BU-CY-ATG). In a multivariate analysis, a conditioning regimen other than BU-CY and BU-CY-ATG was the only independent factor associated with transplantation failure. Given the improved outcome for WAS patients following transplantation from an unrelated donor, we conclude that patients with WAS should receive SCT as soon as possible after diagnosis.

Adolescent↗
PubMed2006

Theophylline metabolism in acute asthma with MxA-indicated viral infection.

BACKGROUND: Although viral infection might alter theophylline metabolism in acute asthma, there are some difficulties in detecting infection due to various kinds of viruses in a clinical setting. METHODS: To evaluate the usefulness of assessment of MxA protein in acute asthma exacerbated by viral infection, MxA protein expression in lymphocytes was assayed by flow cytometric analysis in whole peripheral blood in 21 children (aged 0-6 years) receiving continuous theophylline infusion for management of asthma attack. Serum theophylline levels were measured at 24 and 72 h after initiating theophylline infusion. RESULTS: At the beginning of theophylline infusion, 11 children had increased expression of MxA protein, indicating viral infected states. After 24 h continuous infusion, there were no differences in theophylline levels between MxA-negative and MxA-positive groups. After 72 h infusion, the mean theophylline level of MxA-positive children was significantly higher than that of MxA-negative children (9.7 +/- 2.2 microg/mL vs 7.3 +/- 1.6 microg/mL). The ratio of theophylline clearance at 72 h to that at 24 h in the MxA-positive group was significantly lower than that of the MxA-negative group (1.1 +/- 0.2 vs 1.4 +/- 0.1). CONCLUSIONS: Viral infection appeared to affect theophylline metabolism. Flow cytometric assay of lymphoid MxA protein expression in whole blood is an easy and useful method of evaluating viral infection in acute asthma exacerbation.

Acute Disease↗
PubMed2006

Ability of preschool children to use dry powder inhalers as evaluated by In-Check Meter.

BACKGROUND: Although current guidelines recommend the pressurized metered-dose inhaler with a spacer for preschool children with asthma, dry powder inhalers (DPI) may be a valuable treatment alternative. METHODS: To evaluate the ability of preschool children to inhale through DPI, peak inspiratory flow rates (PIFR) of 57 healthy children aged 3-6 years were measured with In-Check Meter after practising with an instructor. Two different calibrated resistances were attached to the Meter to mimic the internal resistance of each inhaler; Diskus and Turbuhaler. RESULTS: The ability of children to generate adequate inspiratory flow increased with age. The percentages of the 3-, 4-, 5-, and 6-year-old children who were able to inhale reliably through the devices were 30% (3/10), 79.0% (15/19), 100% (16/16), and 100% (12/12), respectively. In these children, 100%, 93.3%, 100%, and 100% achieved an adequate PIFR for the Diskus (30 L/min). In contrast, 66.7%, 66.7%, 62.5%, and 91.7% generated an adequate PIFR for the Turbuhaler (60 L/min). CONCLUSIONS: The In-Check Meter is a useful device to assess the ability of preschool children to generate adequate PIFR for each inhaler. Most children aged > or =5 years could use DPI.

Age Factors↗
PubMed2006

Clinical and genetic analyses of presumed Shwachman-Diamond syndrome in Japan.

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, and skeletal abnormalities. SBDS was identified as a causative gene for SDS in 2003, and genetic analyses of SDS have been performed. We performed genetic analysis of 13 Japanese patients with presumed SDS and found that 10 of them had SBDS mutations. Most patients had recurrent mutations (181-184TA-->CT and 258+2T-->C); however, 2 patients had unique mutations (259-1G-->A and 428C-->G). Although genetic analysis is useful for definitive diagnosis and for genetic counseling of SDS patients and families, SDS appears to be a genetically heterogeneous disorder. In addition, presumed SDS patients without SBDS mutations may be included in other disorders.

Abnormalities, Multiple↗
PubMed2006

X-linked agammaglobulinemia diagnosed in adulthood: a case report.

X-linked agammaglobulinemia (XLA) is a humoral immunodeficiency caused by mutations in Bruton's tyrosine kinase (BTK). Patients typically become symptomatic during infancy or early childhood and develop recurrent bacterial infections. We report a Japanese case of XLA diagnosed in a patient who was 27 years of age and who had no history of severe infection. The patient's serum immunoglobulin (Ig) G, IgA, and IgM levels were 132,7, and 17 mg/dL, respectively. The percentage of positive cells for CD19 and CD20 was 0.03% and 0.02%, respectively. The patient's brother and sister had no abnormalities. Flow cytometric analysis showed a partially reduced expression of BTK protein in the patient's peripheral monocytes. Sequencing of the BTK. gene revealed a missense mutation (230C>T,T33I). Given this data, this patient was diagnosed as having rare, late onset XLA with a missense mutation in the BTK gene.

Adult↗
PubMed2006

Safety and usefulness of a novel eMotion electric mesh nebulizer in children with asthma.

BACKGROUND: A new electronic mesh nebulizer, eMotion is known to have higher performance compared to conventional nebulizers. However, there are some concerns about whether too much delivered dose might cause side effects with higher frequency. METHODS: To evaluate the safety and usefulness of the nebulizer, we measured changes in heart rates and lung functions of 73 asthmatic children when they inhaled 1 microg/kg of procaterol with eMotion or a conventional nebulizer, Junior BOY. RESULTS: In 34 children with mild asthma exacerbation, physical findings, lung function and transcutaneous oxygen saturation levels were improved after inhalation using both nebulizers. No adverse effects including significant increase of heart rate were found. Improvements in the rates of the parameters were comparable. When response to beta2-agonist inhalation was checked in 39 children in stable condition, similar degrees of improvement in lung function were observed, and heart rates did not change after inhalation with either nebulizers. CONCLUSIONS: Safety and efficacy was comparable between eMotion and a conventional nebulizer when it was used to administer beta2-agonists in asthmatic children. However, from the fact that eMotion needs only 3-4 minutes to inhale 2 mL solution, eMotion could be more useful for most children who usually do not prefer longer inhalation time with conventional compressor nebulizers.

Administration, Inhalation↗
PubMed2005

X-linked lymphoproliferative disease associated with hypogammaglobulinemia and growth-hormone deficiency.

X-linked lymphoproliferative disease is a rare immunodeficiency disorder characterized by extreme vulnerability to Epstein-Barr virus, dysgammaglobulinemia, and very high incidence of lymphoma. Growth-hormone deficiency has been described in rare cases to be associated with certain immunodeficiencies, such as X-linked agammaglobulinemia. We report a first case with X-linked lymphoproliferative disease associated with hypogammaglobulinemia and growth-hormone deficiency, which was confirmed by SAP gene mutation. The patient's mutation is novel. He is also the first patient with X-linked lymphoproliferative disease to be reported from Saudi Arabia. The patient's Btk expression and BTK gene were normal. Patients with hypogammaglobulinemia and GH deficiency should be considered to have not only X-linked agammaglobulinemia, but also X-linked lymphoproliferative disease.

Child↗
PubMed2005

Membranoproliferative glomerulonephritis in a patient with X-linked agammaglobulinemia.

Immune complex and complement systems play an important role in membranoproliferative glomerulonephritis (MPGN). X-linked agammaglobulinemia (XLA) is a primary immunodeficiency characterized by severe hypogammaglobulinemia. We report the case of an XLA patient who developed MPGN during an intravenous immunoglobulin (IVIG) treatment. In this patient, the serum IgG level was maintained at more than 400 mg/dl of regular IVIG administration (2.5 g/dose/month). The patient presented with microscopic hematuria, proteinuria (U-pro/Cr: 4.0-4.2) and low serum complement levels (C3: 57.8 mg/dl) 3 years after IVIG treatment and was diagnosed histopathologically as having MPGN type III. Both hematuria and proteinuria significantly improved, and the serum complement level returned to a normal level following methylprednisolone pulse therapy. To our knowledge, this is the first case report of MPGN associated with XLA. Although it is unclear how MPGN occurred in this XLA patient, we suggest that residual humoral immunity in the patient could be associated with the development of MPGN.

Agammaglobulinemia↗
PubMed2005

Rapid detection of intracellular SH2D1A protein in cytotoxic lymphocytes from patients with X-linked lymphoproliferative disease and their family members.

Mutations in the SH2D1A gene have been described in most patients with the clinical syndrome of X-linked lymphoproliferative disease (XLP). The diagnosis of XLP is still difficult given its clinical heterogeneity and the lack of a readily available rapid diagnostic laboratory test, particularly in patients without a family history of XLP. XLP should always be a consideration in males with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Four-color flow cytometric analysis was used to establish normal patterns of SH2D1A protein expression in lymphocyte subsets for healthy subjects. Three of 4 patients with XLP, as confirmed by the detection of mutations in the SH2D1A gene, had minimal intracellular SH2D1A protein in all cytotoxic cell types. The remaining patient lacked intracellular SH2D1A protein in CD56+ natural killer (NK) and T lymphocytes and had an abnormal bimodal pattern in CD8+ T cells. Carriers of SH2D1A mutations had decreased SH2D1A protein staining patterns compared with healthy controls. Eleven males with clinical syndromes consistent with XLP, predominantly EBV-HLH, had patterns of SH2D1A protein expression similar to those of healthy controls. Four-color flow cytometry provides diagnostic information that may speed the identification of this fatal disease, differentiating it from other causes of EBV-HLH.

Adolescent↗