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Biomedical subjects

M Mitsuhashi

Publications and source records attributed to M Mitsuhashi.

At least 91 records · Page 5Linked to original sources

Bronchial hyperresponsiveness in younger children with asthma.

We have previously reported a new technique of evaluating bronchial responsiveness by monitoring the transcutaneous oxygen pressure (tcPO2). This method is so simple, painless, and effortless with high reproducibility that it is possible to use the technique on children as young as 2 years old. Consequently, we used this method to study bronchial hyperresponsiveness in 141 children with asthma and 46 disease controls without asthma or chronic respiratory disorder. The bronchial responsiveness in asthmatic children aged 2 to 5 years was higher than in the disease controls (P less than .001). Further, bronchial responsiveness was significantly higher in moderately as opposed to minimally affected asthmatics (P less than .01), and was gradually higher according to clinical severity. In other age groups as well, the bronchial responsiveness of asthmatic children was higher than of disease controls. There was a close relationship between the level of increased bronchial responsiveness and the clinical severity of asthmatic children.

Adolescent↗

Characterization of a monoclonal antibody against the lymphoblast substance P receptor.

A murine monoclonal antibody to the IM-9 lymphoblast substance P (SP) receptor has been produced which recognizes the membrane-associated proteins of the SP receptor as demonstrated by immunoprecipitation of [125I]SP affinity-labeled and [35S]methionine biosynthetically labeled IM-9 soluble membranes. SP and anti-SP receptor binding to [35S]methionine-labeled IM-9 cell proteins were directly compared by attachment of each to affinity supports. Eluants from these affinity columns were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and revealed an equivalent 33-kDa protein in both cases. This protein corresponds to one of the previously described [125I]SP specifically affinity-labeled membrane-associated proteins. In addition, two-color fluorescence-activated cell sorter analysis with human peripheral blood T lymphocytes with fluorescein-SP and rhodamine-labeled antireceptor antibody revealed a distinct population of cells (20 to 30%) that were equally labeled by both the fluorescent peptide and antibody. This result indicates that the anti-SP receptor antibody recognizes an epitope of the receptor that is common to both human peripheral blood T lymphocytes and IM-9 lymphoblast cells.

Animals↗

The mitogenic effects of vasoactive neuropeptides on cultured smooth muscle cell lines.

In order to investigate the relationship between the biochemical pathways that characterize contraction and cell growth, we have studied both contraction, mitogenesis and protein synthesis induced by the vasoactive neuropeptides, substance P (SP), calcitonin gene related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) on four different established vascular and nonvascular smooth muscle cell lines. Contraction in vitro was evaluated by light microscopy and recorded photographically. Mitogenesis and protein synthesis were evaluated by [3H]-thymidine incorporation into cells and [3H]-amino acid incorporation into trichloroacetic acid precipitated materials, respectively. SP stimulated mitogenesis of A7r5 cells (embryonic rat aorta), but failed to induce significant contraction of these cells, whereas, SP induced contraction of cultured adult rat vascular smooth muscle cells (VSMC), but failed to stimulate mitogenesis. CGRP and VIP stimulated mitogenesis and protein synthesis, respectively, of DDT1MF-2 cells (hamster vas deferens), but neither induced contraction of this cell line. All three neuropeptides showed no effect on BC3H1 (mouse smooth muscle-like) cells. These results suggest that neuropeptides with vasoactive properties modulate different stages of cellular mitogenic responses which may be regulated by the degree of maturation of smooth muscle cell.

Animals↗

Bronchial hyperresponsiveness in children with atopic and nonatopic asthma.

We have studied the bronchial hyperresponsiveness of children with atopic and nonatopic asthma by methacholine inhalation challenge, using a new device, the "Astograph." Three parameters, initial respiratory resistance (Rrs cont), bronchial sensitivity (Dmin), and bronchial reactivity (St), were studied. The Rrs cont values of atopic asthma were higher than those of the disease controls (p less than 0.05), while there was no difference between nonatopic asthma and disease controls. The Dmin values of atopic and nonatopic asthma were lower than those of disease controls (p less than 0.001; p less than 0.01). The St values of atopic and nonatopic asthma were higher than those of disease controls (p less than 0.001; p less than 0.01). There was no difference of Rrs cont and Dmin between the children with atopic and nonatopic asthma. However, St of the children with nonatopic asthma was remarkably higher than that of the children with atopic asthma (p less than 0.001). These data suggested that there was a remarkable difference of bronchial response to methacholine between the children with atopic asthma and those with nonatopic asthma.

Airway Resistance↗

Effect of inhaled procaterol hydrochloride in children with bronchial asthma, with particular reference to duration of effect.

This double-blind crossover trial evaluated the prolonged clinical effect of procaterol inhaled in a dose of 10 micrograms by nine asthmatic children with mild and stable respiratory disturbance. To compare procaterol with the placebo administered with a pressurized metered-dose inhaler 48 hr before or after procaterol, FVC, FEV1, V50, and V25 were followed up for 10 hr. FVC did not indicate a significant difference between the two treatments, while FEV1, V50, and V25 showed significantly greater changes after procaterol administration. The duration of action of procaterol in terms of FEV1, V50, and V25 was 6, 10, and 4 hr, respectively.

Adolescent↗

Beat-to-beat variation of the heart rate in children with allergic asthma.

Beat-to-beat variation of the heart rate in 53 allergic asthmatic children was quantitatively measured as a coefficient of variation of the R-R interval (CVR-R), and was compared with that of 284 nonallergic and 47 allergic children without asthma. Allergic children both with and without asthma had significantly higher mean CVR-R values (7.08 +/- 1.87 and 7.54 +/- 2.40 and p less than 0.01 and p less than 0.001, respectively) than those of non-allergic children (6.32 +/- 1.88). These results confirm the previous reports that the increased cholinergic tone was related to the allergic state and not only to allergic asthma.

Asthma↗

Hyperresponsiveness of cough receptors in patients with bronchial asthma.

The hyperresponsiveness of cough receptors was evaluated using the acetic acid inhalation test in healthy adults, patients with bronchial asthma, and children with or without cough. The concentration of acetic acid inducing cough was more than 20% in all 16 healthy adults and 18 children in the control group. There were two groups of asthmatic patients: Those in group 1 showed normal response to more than 20% acetic acid (n = 46), and those in group 2 showed a sensitive reaction to less than 10% (n = 11). Mean age was 9.0 +/- 4.2 years in group 1 and 15.1 +/- 7.6 years in group 2 (statistical significance, P less than .001). Six of 11 asthmatic patients in group 2 were classified as nonallergic asthmatics, whereas only five of 46 patients in group 1 were nonallergic (P less than .01). Bronchoconstriction was not induced in any case, in spite of the production of cough. It is suggested that the hyperresponsiveness of individual cough receptors without the stimulation of irritant receptors be evaluated.

Acetates↗

Simple and rapid estimation of serum theophylline concentration using apoenzyme reactivation immunoassay.

Theophylline concentration was measured by the apoenzyme reactivation immunoassay system using the Seralyzer system. The results were compared with those obtained employing high performance liquid chromatography and substrate-labelled fluorescent immunoassay. The results obtained by the above three methods were quite compatible with each other. Furthermore, the capillary method was quite compatible with the venous method which is useful for frequent measurement of theophylline concentrations, especially in children with asthma.

Apoenzymes↗

The evaluation of gastroesophageal reflux symptoms in patients with bronchial asthma.

Lower esophageal sphincter pressure (LESP) and extended pH monitoring of the distal esophagus were assessed in 15 asthmatic children in order to evaluate the most important symptoms of suspected gastroesophageal reflux (GER)-asthma. As a result, episodes of asthmatic attacks after overeating were closely correlated with GER as determined by decreased LESP and high pH score.

Adolescent↗

A new method of estimating bronchial hyper-responsiveness in younger children.

By using the new device, the "Astograph," it is possible to measure the continuous changes of respiratory resistance (Rrs) during bronchial inhalation challenge. This method, however, is not suitable for younger children because of wide variations in Rrs. So we studied a technique using a transcutaneous oxygen pressure (tcPO2) monitoring system. The bronchial reactivity and sensitivity were significantly correlated between Rrs and tcPO2 (P less than .001), and there was no correlation between cardiac output and Rrs. The tcPO2-method is useful for measuring bronchial responsiveness, especially in younger children.

Adolescent↗