Niroku Koya

Human peripheral eosinophils express functional interferon‐gamma receptors (IFN‐γR)

In order to determine whether or not IFN‐γR is associated with regulatory mechanisms on human eosinophil function, we examined the expression of functional IFN‐γR on human peripheral eosinophils. In this study, peripheral blood eosinophils were obtained from seven normal controls and 12 patients (bronchial asthma, n = 9, and hypereosinophilic syndrome (HES), n = 3), and the purity of eosinophils was 97.11 ± 2. 31%, n = 19. We first showed that anti‐IFN‐γR α‐chain MoAb reacted with all tested eosinophils of both normal controls and patients by flow cytometry analysis. We also showed expression of mRNA for the α‐chain of IFN‐γR in all purified eosinophils of six individuals. Further, to characterize IFN‐γR on eosinophils, we did binding experiments with 125I‐IFN‐γ on purified peripheral eosinophils. The linear Scatchard plot indicated a single type of high‐affinity binding sites (dissociation constant (Kd) = 3.89–4.95 × 10−10 M, numbers of binding sites = 183–233/cell, n = 3). To determine whether IFN‐γR on eosinophils is functional, we examined surface eosinophilic cationic protein (ECP) and CD69 induction after IFN‐γR ligation with recombinant human IFN‐γ (rhIFN‐γ) on eosinophils by flow cytometry. rhIFN‐γ stimulation significantly induced both ECP and CD69 expression on the 2–18 h‐cultured eosinophils in a dose‐dependent manner. Further, the effects of rhIFN‐γ stimulation were significantly blocked by both a neutralizing anti‐IFN‐γ MoAb and a blocking anti‐IFN‐γR MoAb. These results suggest that human peripheral eosinophils express functional IFN‐γR.

Role of JAK2 signal transductional pathway in activation and survival of human peripheral eosinophils by interferon-gamma (IFN-γ)

The purpose of this study was to determine whether the JAK pathway is involved in eosinophil activation and survival through IFN‐γ receptor signalling in human peripheral eosinophils. Eosinophils were purified from the blood of six atopic disease patients by anti‐CD16 magnetic bead‐negative selection. IFN‐γ significantly up‐regulated survival and CD69 expression in 24–48 h cultured eosinophils. Further, IFN‐γ induced tyrosine phosphorylation of JAK2 in eosinophils, as indicated by Western blot analysis. Finally, the specific JAK2 inhibitor AG‐490 inhibited the tyrosine phosphorylation of JAK2, IFN‐γ‐induced survival and CD69 expression in eosinophils. In conclusion, these results indicate that IFN‐γ induces eosinophil survival and CD69 expression through the activation of JAK2 in peripheral eosinophils, suggesting that JAK2 may play a significant role in eosinophil regulation by IFN‐γ–IFN‐γR interaction.

Study of Liver Function in Infants with Atopic Dermatitis Using the 13C-Methacetin Breath Test

Serum glutamic-oxaloacetic transaminase (GOT) levels were determined in 214 infants (133 males and 81 females) with atopic dermatitis during their first visit to the Department of Allergy, National Childrens Hospital, Tokyo, Japan. Compared with the normal hospital range, their levels were found to be significantly higher, a tendency which was more conspicuous in lower age groups. We carried out a 13C-methacetin breath test (MBT), administering the stable-isotope-labeled compound to 11 children with higher serum GOT values and 5 within the normal range to investigate hepatic metabolism of methacetin in infants with atopic dermatitis. 13C-methacetin was given orally, and the 13CO2 level in the breath was determined immediately before and after administration, by mass spectrometry. Compared to the normal controls, the atopic infants demonstrated significantly lower 13CO2 peak excretion and delayed peak time. The clearance rate of 13CO2 was also decreased. These results suggest some relationship between atopic dermatitis and liver function in infants.

Heterogeneous Expression of Tumor Necrosis Factor-α Receptors I and II on Human Peripheral Eosinophils

Background: Expression of the tumor necrosis factor-α receptor by human eosinophils has not been determined. We examined the surface expression and mRNA for tumor necrosis factor-α receptors I and II (TNF-αRI and TNF-αRII) on peripheral eosinophils. Methods: Eosinophils were obtained from 17 asthma patients and 3 healthy volunteers. Flow cytometry was used to examine receptor expression, and the reverse transcriptase-polymerase chain reaction was used to examine receptor mRNA expression. Results: Flow cytometry revealed that 16 out of 20 subjects had eosinophils expressing TNF-αRI and 18 subjects had eosinophils expressing TNF-αRII. All eosinophils expressed at least one receptor. The mRNA for TNF-αRII was detected in all eosinophils examined, but the signals for TNF-αRI mRNA were only found in cells expressing this receptor. Conclusions: Human peripheral eosinophils show heterogeneous expression of TNF-αRI and TNF-αRII.

Continuous Isoproterenol Inhalation Therapy in Children with Severe Asthmatic Attack

We studied the 1-type isoproterenol inhalation therapy for patients with severe asthmatic attacks who were admitted at the Department of Allergy of National Childrens Hospital from 1981 to 1991. One hour after l-type isoproterenol inhalation therapy, statistically significant effects were noted with regard to the asthmatic status. Moreover, no side effect was found amoung the subjects. From these data, 1-type isoproterenol inhalation therapy is thought to be effective for severe asthmatic attacks.

Serum theophylline concentration levels and preventative effects on exercise‐induced asthma

One of the specific characteristics of asthma is bronchia! hyperresponsiveness. Many factors affect asthmatic patients [1]. Exercise is a very important triggering factor for bronchoconstriction in children. School-age asthmatic children are usually required to participate in various sports programmes [2]. There is much in the literature about exercise-induced asthma (EIA). and many studies have been published about the preventive effects and mechanisms of various drugs [3,4]. Many reports exist about exercise-induced early responses, but there is also a iate response phase [5]. The concept of late responses is not well accepted at present. However, in spite of careful treatment, some asthmatic patients may develop an exercise-induced late asthmatic response. The authors have already studied what drugs can be used to prevent exercise-induced late response, but there are no reports concerning bronchodilator effectiveness for preventing it. The authors investigated sustained-release theophylline effects on exercise-induced early and late responses. The effectiveness of the newly-proposed scrum theophylline therapeutic level of 5-15ng/ml, instead of 10-20|ig/ ml. was also studied by testing to sec whether a slightly greater than 5|.ig/nii serum thcophyllitie concentration would be effective at preventing EIA.

Computed tomography of bilateral thalamic hypodensity in acute encephalopathy.

Computed tomography revealed bilateral hypodensity of the thalamus in three patients with acute encephalopathy. In two cases the abnormal findings on CT persisted and were associated with severe neurological sequelae.

Interferon-γ Receptor β-Chain Expression and Formation of α- and β-Chain Complexes after Receptor Conjugation on Human Peripheral Eosinophils

Background: It has been unclear whether or not the interferon-γ receptor (IFN-γR) on human peripheral eosinophils is completely functional. Accordingly, we examined the expression of IFN-γR α- and β-chains and the association of the two chains after binding of IFN-γ to the receptor. Methods: Peripheral blood eosinophils were obtained from 8 patients (bronchial asthma, n=6, and hypereosinophilic syndrome, n=2), and expression of the α- and β-chain was investigated by flow cytometry with specific antibodies. Expression of mRNA for the α- and β-subunits was also investigated by the reverse transcriptase-polymerase chain reaction. Results: Eosinophils from all the patients were positive for both the α- and β-chains by flow cytometry. In addition, mRNA for both chains was detected by the polymerase chain reaction. Furthermore, coprecipitation of the α- and β-chains was only found after eosinophil stimulation with IFN-γ. Conclusions: Human peripheral eosinophils apparently express both the α- and β-chains of the IFN-γR, and the two chains may only form the receptor complex after ligand binding.

Ten years follow up study of steroid therapy for congenital encephalomyopathy

Two 10-year-old boys with mental retardation and myopathy which were present since birth are described. Both had elevated serum creatine phosphokinase (CK) and one of them had a positive family history. The clinical features were consistent with Fukuyama type congenital muscular dystrophy, but muscle biopsies suggested an inflammatory process. Adrenal cortical steroids were given and they were followed up until 10 years of age. Serum CK showed a significant response to the treatment, and mental retardation in case 1 and motor dysfunction in case 2 improved. It is postulated that an inflammatory process might be a causative factor in some patients with congenital muscular dystrophy.

Effects of Total Asphyxia on the Development of Synaptic Junctions in the Brains of Mice

Using ethanolic phosphotungstic acid staining, we studied the development of synaptic junctions in the brains of mice subjected to total asphyxia. One‐day‐old mice, Std:ddY strain, were put into a chamber continuously flushed with 100% CO2‐gas for 35 min. The surviving mice (28.1%) were used as experimental models, while unasphyxiated littermates served as controls. The synaptic junctions in the frontal motor cortex and hippocampal cortex were studied at 20 and 60 days of age using E‐PTA staining, and the numbers of synaptic junctions in both areas were counted. In comparison with the control animals, the frontal motor cortex of the subject mice showed a smaller increase in the number of synaptic junctions, both at 20 and at 60 days of age. In the hippocampal cortex, the number of synaptic junctions seen in the experimental mice brains was similar to that in the controls at 20 days of age; however, the number of synaptic junctions in the treated mice brains showed a slower rate of increase than in the controls at 60 days of age.