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Y Sakiyama

Publications and source records attributed to Y Sakiyama.

At least 19 recordsLinked to original sources
PubMed1992

Cytochrome b positive X-linked chronic granulomatous disease: a normal cell surface expression of cytochrome b.

The polymorphonuclear (PMN) cells from a patient with cytochrome b positive X-linked chronic granulomatous disease (Xb+ CGD) were studied using flow cytometry. Both the cell surface expression of monoclonal antibody defined cytochrome b and the superoxide production (intracellular 2',7'-Dichlorofluorescin Diacetate oxidation) were investigated at a single cell level. Flow cytometry clearly demonstrated the complete absence of superoxide production in the patient's PMN cells, the mosaicism in his mother's PMN cells and also indicated the normal cell surface expression of cytochrome b. The results obtained by Western blot analysis and reduced-minus-oxidized spectra confirmed the presence of functional and normal amounts of cytochrome b. We concluded that this is a case of Xb+ CGD with a normal cell surface expression of cytochrome b.

Adolescent↗
PubMed1992

The effect of benzodiazepines on the binding of [3H]SCH 23390 in vivo.

The effect of flunitrazepam upon the binding of [3H]SCH 23390 in vivo was investigated. Acute treatment with flunitrazepam decreased the binding of [3H]SCH 23390 in the striatum in a dose-dependent manner. The time course of radioactivity in the striatum, cerebral cortex and cerebellum in controls and flunitrazepam (1 mg/kg)-treated mice was measured after intravenous injection of [3H]SCH 23390. The binding kinetics were calculated, using the cerebellum as a reference region for the estimation of the amount of free ligand in the brain. Flunitrazepam significantly decreased the input rate constant to the receptor compartment and the dissociation rate constant in vivo. An in vivo displacement study, using carrier SCH 23390, also showed significant reduction in the dissociation rate constant of [3H]SCH 23390 in vivo. The drug Ro 15-1788 reversed the effect of flunitrazepam, suggesting that this reduction in binding of [3H]SCH 23390 was mediated by benzodiazepine receptors. To evaluate the relationship between the reduction in binding of [3H]SCH 23390 in vivo and in vivo occupancy of benzodiazepine receptors, in vivo occupancy of benzodiazepine receptors was measured using [3H]Ro 15-1788. A non-linear relationship was found between the reduction in dopamine D1 receptor binding in vivo and the occupancy of benzodiazepine receptors in vivo, indicating that benzodiazepines exerted the maximum change in dopamine receptor binding at a low fractional occupancy of receptors.

Animals↗
PubMed1992

Progress in primary immunodeficiency.

Clinically, primary immunodeficiencies can be grouped into several well-defined syndromes. This consistent clinical picture, however, belies the enormous complexity of lymphocyte maturation and activation, and it has long been suspected that numerous distinct underlying defects give rise to primary immunodeficiencies. At a recent workshop, the molecular and genetic characterization of a handful of such defects provided tacit support for such suspicions.

Adenosine Deaminase↗
PubMed1992

Eosinophil cationic protein in peripheral blood of pediatric patients with allergic diseases.

We have studied the levels of eosinophil cationic protein (ECP) and tumour necrosis factor (TNF) in peripheral blood obtained from 68 children with bronchial asthma and 11 children with atopic dermatitis. The ECP mean concentrations of the patients were 23.7 +/- 21.4 micrograms/l and 21.2 +/- 18.7 micrograms/l for bronchial asthma and atopic dermatitis respectively, which were significantly higher than the control value, 5.8 +/- 2.3 micrograms/l (P less than 0.005). TNF was unmeasurable in almost all the samples and no significant difference was observed between normal controls and asthmatic children. A significant correlation was observed between serum levels of ECP and blood eosinophil counts in both diseases (r = 0.873; P less than 0.01 and r = 0.740; P less than 0.01, respectively). However, no obvious correlation was observed between serum levels of ECP and IgE levels. ECP levels were significantly reduced by treatment and normalized in parallel with blood eosinophil counts in the patients with total IgE levels less than 800 U/ml. Irrespective of the total IgE levels, the reduction of serum ECP levels was correlated with a decrease in the number of asthmatic attacks and/or improvement of pulmonary function. These results suggest that the ECP levels in peripheral blood indicate an increased activity of eosinophil and would be a more useful marker than eosinophil counts for making clinical analyses and estimating treatment efficacy in paediatric patients with allergic diseases.

Adolescent↗
PubMed1992

Hyper-response of serum IgG1 to Staphylococcus aureus peptidoglycan in patients with hyper-IgE syndrome.

The hyper-IgE (HIE) syndrome is characterized by high IgE serum levels, chronic dermatitis and recurrent infections. To determine whether an impairment of the antibody response to Staphylococcus aureus contributes to infections in this syndrome we measured total serum IgG subclass, specific IgG1 and IgG2 levels against peptidoglycan (PG), the immunodominant cell wall component of S. aureus and serum opsonic activity to PG. Of the 14 patients with HIE syndrome, nine had increased level of serum IgG1 and six had IgG2 subclass deficiency. In regard to specific response of IgG1 and IgG2 antibodies to PG, patients were divided into five groups related to ages and compared with 10 control subjects for each age cohort. Patients with HIE syndrome had significant high levels of serum-specific IgG1 to PG and significant decreased levels of serum-specific IgG2 to PG in all five groups. Additionally, serum opsonic activity in patients was significantly higher than that in normal control subjects. It is concluded that IgG2 deficiency or poor IgG2 antibody response to S. aureus is not the explanation of the abnormal susceptibility to S. aureus infections of HIE patients.

Adolescent↗
PubMed1992

Primary immunodeficiency diseases and Epstein-Barr virus-induced lymphoproliferative disorders.

Increased incidence of malignant disorders is noted in patients with both primary and acquired immunodeficiency diseases. The pathogenetic mechanism(s) for these disorders remain unclear. Defective immunosurveillance of these patients, however, is mainly postulated to be responsible for the increased risk of these malignant disorders. Of the malignant disorders, Epstein-Barr virus (EBV)-induced lymphoproliferative disorders (LPD) have been increasingly reported, possibly due to improved therapeutic management techniques such as bone marrow transplantation, which results in prolonged survival periods for the primary immunodeficiency; the dramatic development of immunosuppressive treatments for transplant recipients; and the growing numbers of acquired immunodeficiency syndrome (AIDS) patients. This review focuses on the primary immunodeficiency diseases and EBV-induced LPD, and discusses pathogenetic mechanism(s) for the increased incidence of these malignant disorders.

Adolescent↗
PubMed1992

Phenytoin-induced IgG2 and IgG4 deficiencies in a patient with epilepsy.

A five-year-old girl with epilepsy and recurrent respiratory infections was investigated for serum IgG subclass concentrations. She was diagnosed as having a combined deficiency of IgG2 and IgG4 with a decreased serum concentration of IgA and IgG3 and was given replacement therapy with i.v. immunoglobulins. Since then, she has been free from respiratory infections. After phenytoin therapy was stopped, IgG subclass deficiency improved. This case describes the further action of phenytoin on the immune system, adding IgG subclass deficiency to the list.

Child, Preschool↗
PubMed1992

Genetic heterogeneity in patients with X-linked recessive chronic granulomatous disease.

Genetic heterogeneity in 12 patients from 11 different families with X-linked recessive chronic granulomatous disease was studied by Southern blot analysis using cytochrome b heavy-chain cDNA as a probe. We found the abnormal restriction length fragment patterns of the cytochrome b heavy-chain gene in three families, which were not observed in healthy controls. DNA from one patient showed the abnormal patterns after digestion with several restriction enzymes. The DNA of two other patients showed the abnormality only with TaqI and PstI. Analysis of the same family members indicated that these abnormal patterns cosegregated with the disease. The other nine patients from eight families did not have any abnormalities detectable by Southern blot analysis. Although further experimentation should be done to study the molecular genetic heterogeneity in most X-linked chronic granulomatous disease families (eight of 11), we were able to demonstrate at least three different types of mutations in the cytochrome b heavy-chain gene responsible for the disease.

Adolescent↗
PubMed1992

Measurement of IgG subclass antibodies to the group II antigen of Dermatophagoides pteronyssinus (Der p II) in sera from children with bronchial asthma.

Seven IgG-binding components in crude mite allergen extracted from Dermatophagoides pteronyssinus (Der p) were identified by immunoblotting analysis. Of these components, the 15-kDa protein was strongly recognized by IgG from patients with bronchial asthma, whereas it was less recognized by IgG from healthy individuals. Then, the 15-kDa protein was purified by reverse-phase high performance liquid chromatography and the protein was demonstrated to induce immediate positive skin reactions in patients with bronchial asthma. The N-terminal amino acid sequence of the 15-kDa protein was also determined and was in agreement with that of Der p II. In an attempt to understand the role of IgG subclass antibody of patients with bronchial asthma, we quantitated the antibodies of IgG subclass to Der p II. The levels of antibodies of total IgG and of all IgG subclasses in patients with bronchial asthma who had never received immunotherapy were higher than those of nonatopic healthy individuals. The levels of Der p II-specific IgG1 and IgG4 in asthmatic patients were 1.97 times and 2.20 times higher, respectively, than those in the control group. The present study demonstrates that patients with bronchial asthma are able to produce antibodies of all IgG subclasses specific to Der p II in response to natural exposure to mite antigen.

Adolescent↗
PubMed1991

Interleukin-4 regulates the interleukin-2 receptors on human peripheral blood B lymphocytes.

The high-affinity interleukin-2 (IL-2) receptor (IL-2R) consists of the non-covalent association of at least two subunits, p55 and p70-75, capable of binding IL-2 with low and intermediate affinity, respectively. We studied the effects of cytokines on the IL-2R expressed on human peripheral blood B lymphocytes using monoclonal antibodies specific for IL-2R p55 and IL-2R p70-75, by means of two-colour flow cytometric analysis. In freshly isolated peripheral blood B lymphocytes, the p55 subunit was expressed only in a small population (7.0% of CD20+ cells), whereas the p70-75 subunit was expressed in a large population (89.0% of CD20+ cells). Of the cytokines studied, interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) were involved in the regulation of IL-2R on B cells. After a 2-day incubation with IL-4, expression of IL-2R p55 was markedly induced, but expression of IL2-R p70-75 was profoundly suppressed in a dose-dependent manner. These abilities of IL-4 to promote IL-2R p55 expression and suppress IL-2R p70-75 expression were inhibited by the presence of IFN-gamma. Other cytokines, including IL-1, IL-2, IL-5, and IL-6, had little effect on the expression of these two subunits. These findings suggest that IL-4 is a cytokine modulating B cell response through the regulation of IL-2R.

B-Lymphocytes↗
PubMed1991

Severe chronic active Epstein-Barr virus infection syndrome.

Reports of unusually severe lymphoproliferative disorders associated with extremely high antibody titers against Epstein-Barr virus (EBV) have recently increased. The syndrome, which we designated severe chronic active EBV infection syndrome, is characterized by persistent or intermittent fever, lymphadenopathy, and hepatosplenomegaly and primarily affects children and young adults. Polyclonal gammopathy and bone marrow suppression are generally observed, and some patients develop B-cell or T-cell lymphoproliferation or lymphoma. Frequently, EBV genomes are detectable in tissues infiltrated with lymphoid cells. Additionally, it is difficult to establish spontaneous or B95-8 EBV-induced cell lines despite the expression of an activated EBV infection. We review and report here the published medical literature and our own experience regarding patients with severe chronic active EBV infection syndrome in an attempt to understand this enigmatic syndrome and the possible pathogenetic mechanism(s) responsible for this disorder.

Chronic Disease↗
PubMed1990

Adenovirus infection in patients with Kawasaki disease.

Two outbreaks of Kawasaki disease at different times and areas (Kyoto in 1982 and Sapporo in 1985) of Japan were studied retrospectively for the presence of antibodies to adenoviruses and herpesviruses. Only 2 of 12 (16.7%) consecutive acute phase sera of patients from the outbreak in 1982 and 1 of 10 (10.0%) sera from 1985 showed positive antibodies for the common adenovirus antigen by a complement fixation (CF) test, whereas 10 of 16 (62.5%) age- and sex-matched controls during the outbreak of Kawasaki disease in 1985 were seropositive by the CF test. In contrast, using a recently developed enzyme-linked immunosorbent assay (ELISA), 9 patients (75.0%) in 1982 and 9 patients (90.0%) in 1985 had antibodies to adenovirus type 2. In addition, 5 of 10 (50.0%) of the 1982 and 6 of 9 (66.7%) of the 1985 patients who were seronegative for CF antibodies were positive for IgM antibodies to adenovirus type 2. Fifteen (93.8%) controls were positive for antibodies to adenovirus type 2 by ELISA and only two sera showed negative CF antibodies with positive IgM antibodies to adenovirus type 2. Sequential sera from 4 patients in 1985 had either IgM or IgG antibodies by ELISA and eventually three became seropositive by the CF test in time. Additionally, no significant difference was noted with antibody status to herpes simplex virus type 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), and cytomegalovirus (CMV) between patients and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenovirus Infections, Human↗
PubMed1990

The inductive effect of interleukin-4 on IgG4 and IgE synthesis in human peripheral blood lymphocytes.

Using murine monoclonal antibodies against human IgG subclasses, specific and sensitive ELISAs assay to quantify the four human IgG subclasses in cell culture supernatants were established. The effect of human recombinant interleukin-4 (IL-4) on the regulation of IgG subclasses by normal peripheral blood lymphocytes was investigated. In addition to the enhancement of IgE synthesis, IL-4 preferentially induced IgG4 synthesis in vitro, whereas IL-4 had no effect on IgG1, IgG2, and IgG3 synthesis. IL-4-induced IgG4 production was blocked in a dose-dependent manner by recombinant interferon-gamma and anti-human IL-4 monoclonal antibody. Collectively, this data indicates that IL-4 plays an important regulatory role in both IgG subclass and IgE synthesis.

B-Lymphocytes↗
PubMed1990

Quantitation of IgG subclass antibodies to pneumococcal capsular polysaccharides by ELISA, using Pneumovax-specific antibodies as a reference.

A quantitative enzyme-linked immunosorbent assay (ELISA) method has been developed to assay the levels of IgG subclasses to pneumococcal capsular polysaccharides (PCP) by using a reference standard. This standard solution containing specific antibodies to a polyvalent pneumococcal vaccine (Pneumovax) was purified from the serum of an immunized healthy adult by affinity chromatography. In order to determine the predominant response to Pneumovax in the four IgG subclasses, specific IgG subclasses in preimmune and postimmune sera from six healthy adults were assessed quantitatively by the ELISA. With regard to peak concentrations after immunization, there was a marked increase in the IgG2 subclass, compared with those of IgG1 and IgG3. Such a quantitative assay of Pneumovax-specific IgG subclass antibodies is useful for the direct evaluation of immune responses to immunization with a polyvalent pneumococcal vaccine, and at the same time, for estimating the IgG2 response to PCP antigens in individuals.

Animals↗