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Biomedical subjects

J Nakata

Publications and source records attributed to J Nakata.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Effect of macrolide antibiotics on airway goblet hypersecretion in guinea pigs].

Although macrolide antibiotics have now been widely used in the treatment of chronic airway infections including diffuse panbronchiolitis and chronic bronchitis, the mechanism of the efficacy remains uncertain. Because the increased mucus glycoprotein secretion from airway goblet cells may play a significant role in the development of such diseases, to determine the effects of macrolides on airway goblet cell secretion, we studied guinea pig airways by a semiquantitative morphometric method. The goblet cell secretion was assessed in histological sections of the trachea and main bronchi stained with Alcian blue and PAS by determining mucus score, which is inversely related to the magnitude of mucus discharge. Intravenous IL-8 decreased mucus score in a dose-dependent manner and increased the number of neutrophils present in bronchoalveolar lavage fluid. Oral administration of clarithromycin at a daily dose of 1-10 mg/day for 2 weeks dose-dependently inhibited IL-8 (5 mg/ kg)-induced decrease in mucus score, with the maximal inhibition being 54 +/- 11% (p < 0.001) in the trachea and 48 +/- 8% (p < 0.01) in the main bronchi. This effect was accompanied by the inhibition of neutrophil accumulation into bronchoalveolar lavage fluid. Erythromycin produced similar inhibitory effects on IL-8-induced goblet cell secretion and neutrophil accumulation, whereas amoxicillin and cefaclor had no effect. These results suggest that macrolides protect against goblet cell hypersecretion probably through an inhibition of recruitment of neutrophils into the airway mucosa.

Animals↗
PubMed1996

Effects of roxithromycin and erythromycin on interleukin 8-induced neutrophil recruitment and goblet cell secretion in guinea pig tracheas.

Inhaled interleukin 8 caused an increase in goblet cell secretion in guinea pig tracheas, which was accompanied by mucosal infiltration of neutrophils. These responses were inhibited by pretreatment with roxithromycin or erythromycin in a dose-dependent fashion. Macrolides may thus be a value in protecting against neutrophil-associated airway hypersecretion.

Animals↗
PubMed1996

Effect of oxitropium bromide on histamine-induced airway goblet cell secretion.

To determine whether histamine affects airway goblet cell secretion and, if so, whether cholinergic mechanism is involved, we studied guinea pig airways by a semiquantitative morphometric method. The goblet cell secretion was assessed in histologic sections of the tracheal mucosa stained with Alcian blue and periodic acid-Schiff (PAS) by determining the mucus score, which is inversely related to the magnitude of mucus discharge. Inhaled or intravenously administrated histamine dose dependently decreased the mucus score, an effect that was similarly observed in cartilaginous and muscular portions. Inhalation of the anticholinergic agent oxitropium bromide at doses of 1.5 micrograms and higher greatly attenuated the decrease in mucus score produced by intravenous histamine but not by inhaled histamine. Likewise, cutting of bilateral vagus nerves or atropine abolished intravenous histamine-induced goblet cell secretion. The response of the mucus score to inhaled histamine was abolished by cimetidine, whereas the response to intravenous histamine was reduced by mepyramine but not by cimetidine or thioperamide. These results suggest that inhaled histamine increases airway goblet secretion, probably by stimulating histamine H2-receptors on goblet cells, and that intravenous histamine produces a similar effect through a stimulation of histamine H1-receptor-mediated release of acetylcholine from cholinergic nerve terminals, presumably involving vagal reflex.

Administration, Inhalation↗
PubMed1992

Experimental otitis media with effusion induced by middle ear effusion.

Experimental otitis media with effusion was induced in chinchillas by middle ear effusion, which was induced by an injection of immune complex into the tympanic cavity. To elucidate the pathogenesis of otitis media with effusion, cytologic and biochemical findings of the effusion and histopathology of the middle ear mucosa of effusion-induced chinchillas were compared with those of experimental otitis media with effusion induced by different procedures; eustachian tube obstruction, intratympanic inoculation of endotoxin, and immune reaction. No significant differences were seen in cytology, biochemistry, and histopathology among OMEs induced by these procedures. However, middle ear effusions, when compared with the corresponding sera, were proven to contain higher amounts of histamine and prostaglandin E2. These findings seem to demonstrate that middle ear effusion containing a large number of inflammatory mediators is essential for induction and prolongation of inflammatory reaction in the middle ear.

Animals↗
PubMed1988

Functional and morphological pathology of the nasal mucosa after x-ray irradiation.

In our present study we examined the pathology of the nasal mucociliary system after x-ray irradiation in an animal model namely the rabbit. A reduced ciliary activity was observed immediately after the irradiation and did not show any recovery during our observation. No ciliary activity was seen in the nasal mucosa 8 weeks after the irradiation. Morphologically, hypersecretion of goblet cells was observed immediately after irradiation. Cytoplasmic vacuolation and nuclear pyknosis of ciliated cells started after irradiation, and sloughing of ciliated cells was observed for up to 3 weeks. Epithelial metaplasia started from 4 weeks, and no cilia were seen in the nasal mucosa and the surface of the epithelium was covered with flat squamous cells. Our present study shows that x-ray irradiation has serious influence on the function and structure of the nasal mucociliary system and that recovery from degeneration due to x-ray irradiation cannot be expected within several weeks.

Animals↗
PubMed1988

Reversibility of reduced ciliary activity on adenoids of patients with otitis media with effusion following culture.

We have studied the ciliary activity of the pharyngeal epithelium on adenoids obtained from patients with recurrent otitis media with effusion to assess indirectly the ciliary activity in the Eustachian tube. In conclusion, the following has been speculated from the present study: (1) middle ear effusions depress the ciliary activity; and (2) recovery of the reduced ciliary activity can be achieved in an effusion-free environment inasmuch as the ciliated cells have not undergone organic changes. Prompt elimination of the effusion, if present, is of critical importance for the recuperation of tubotympanic drainage, because a positive therapeutic effect resulting from elimination of the effusion can only be possible in early phase of the disease, before irreversible morphological lesions have occurred.

Adenoids↗
PubMed1987

Nasal allergen sensitivity and mucosal IgE antibodies.

Skin tests, nasal provocation tests, nasal smear tests, and serum-radioallergosorbent tests were performed on 17 patients with perennial allergic rhinitis, who had suffered nasal congestion without receiving any antiallergic treatment. After the above tests, tissue-radioallergosorbent tests (t-RAST) were conducted to determine IgE antibody levels in inferior turbinate mucosal samples taken peroperatively. The results obtained in this study suggest that the allergen sensitivity of the nasal mucosa correlates to some extent with the mucosal IgE antibody level, and that the t-RAST can provide us with objective data about nasal allergen sensitivity.

Humans↗
PubMed1986

Degeneration and regeneration of respiratory mucosa of rats after exposure to styrene.

The recovery process of pathological changes in the respiratory mucosa following exposure to styrene were experimentally studied to improve the understanding of the respiratory toxicity of styrene. Thirty male SD rats were exposed to 150 ppm or 1000 ppm of styrene for 4 h a day over 3 weeks (5 days a week). They were killed for examination at 1 day or 12 weeks after completion of the exposure sequence. Bilateral mucosal samples from the nasal septum and the trachea of the animals were examined for ciliary activity and subjected to electron microscopy. Complete functional and morphological recovery of the nasal and tracheal mucosa was observed at the 12th week post-exposure to 150 ppm of styrene. After exposure to 1000 ppm of styrene, almost normal function and morphology of the tracheal mucosa was found at the 12th week post-exposure, but the nasal mucosa continued to show decreased ciliary activity and an affected morphology.

Animals↗
PubMed1986

Nasal allergy and nasal polyp with special reference to the mucosal IgE antibodies.

Immunologic conditions were studied in 8 patients with nasal allergies and nasal polyps and in 20 patients with nasal polyps. The present study showed the following: Nasal polyp mucosa contains a low level of mucosal IgE antibodies; nasal polyp mucosa is devoid of or deficient in the capacity of producing IgE antibodies; the presence of mucosal IgE antibodies in nasal polyp mucosa does not always imply the clinical manifestation of nasal allergies, and the antigen and antibody interaction does not always result in nasal symptoms.

Humans↗
PubMed1986

[Study of coagulum pyelolithotomy].

Coagulum pyelolithotomy was carried out on 20 patients from January, 1980 to April 1984. Nephrolithotomy was jointly carried out on 4 of them, but residual stones were observed in 4 cases (20%). No side effect such as hepatitis was observed in any cases. While inferring the cause of residue, experimental study was made on tension, coagulation time and mixing method in respect to coagulum formation. In the experiment on tension, no significant difference was observed when thrombin concentration was changed, but when calcium was added, tension increased 4 fold. As thrombin concentration rose, so shortened the coagulation time. It was inferred that a better coagulum is made available if fibrinogen and thrombin are mixed outside the kidney.

Adult↗
PubMed1985

Topical immunology of nasal allergy and mucosal IgE antibodies.

In the present study, the in vitro tissue-radioallergosorbent test (t-RAST) was performed in two groups of patients: one with perennial attacks of sneezing, serous hypersecretion and nasal congestion, the other with nasal congestion only. The results obtained were compared with those obtained by a series of conventional allergy tests. We then found that t-RAST provided objective data comparable to those obtained with serum-RAST and that the t-RAST is a reliable means of quantitatively detecting specific IgE antibodies in the nasal mucosa. t-RAST is of special value to diagnosticians because it is able to discern unequivocally and easily those patients with localized nasal allergy.

Humans↗