Biomedical subjects

F Naka

Publications and source records attributed to F Naka.

10 recordsLinked to original sources

PubMed1991

The sources of chemical substances in allergic nasal fluid.

The sources of different chemical substances in the NF of allergic patient, such as albumin, secretory IgA, histamine, leukotriene, kinin and substance P were investigated. To accomplish this, we challenged the inferior turbinate on one side, but separately collected NF from both sides in patients with nasal allergy to house-dust. Provocation was done with paper disc containing dried allergen extract. Collection was done by suction for the first five minutes immediately after the onset of a positive response to nasal provocation. The total amount of the chemical substances on each side was analyzed separately and compared. Significant differences were seen between both sides only for histamine and leukotriene. In consideration with the previous reports, it is suggested that in nasal allergen challenge the major sources are glandular secretion for secretory IgA, and albumin, and secretion for migrating cells for histamine and leukotriene. The major sources responsible for kinin and substance P, however, are not defined.

Adolescent↗

PubMed1990

Study on pruritus in hemodialysis patients and the antipruritic effect of neurotropin: plasma levels of substance P, somatostatin, IgE, PTH and histamine.

It has been reported that Neurotropin can markedly improve pruritus in patients undergoing hemodialysis (HD). In order to elucidate the probable causes of pruritus and the antipruritic effect of Neurotropin, various biochemical parameters in the plasma of patients before and during HD were investigated. Forty-three patients undergoing HD were divided into three groups. Eighteen patients had suffered no episode of pruritus (group A), 17 patients had on-going pruritus (group B) and the remaining 8 patients had experienced improvement of pruritus following Neurotropin treatment (group C). The mean concentration of substance P was in only B group significantly increased with HD only in B group, indicating that substance P could be one of the causes of pruritus in patients undergoing HD. Neurotropin appears to exert its antipruritic effect by lowering the level of substance P. The change in parathyroid hormone (PTH) level during HD was not significant in any of the groups, but the mean concentration of PTH in group B was higher than that of group A, indicating that PTH may also be one of the causes of pruritus.

Adjuvants, Immunologic↗

PubMed1989

Study on pruritus in hemodialysis patients and the antipruritic effect of neurotropin: plasma levels of C3a, C5a, bradykinin and lipid peroxides.

The causes of pruritus in patients undergoing hemodialysis and the mechanism of the antipruritic effect of Neurotropin, an extract isolated from the inflamed dermis of rabbits inoculated with vaccinia virus and clinically used in Japan as an analgesic and antiallergic drug, were investigated by measuring the levels of C3a, C5a, bradykinin and lipid peroxides in venous blood collected before dialysis, and at 15 min and 4 hr after starting hemodialysis. C3a increased considerably in pruritic patients compared to non-pruritic patients at 15 min after starting hemodialysis. Neurotropin significantly suppressed the C3a level and improved the condition of pruritic patients. There was no significant difference in the level of bradykinin between pruritic patients and non-pruritic patients. Therefore, bradykinin was not thought to be related to the incidence of pruritus in such patients. A tendency towards lowering of the levels of lipid peroxides in the patients' plasma by Neurotropin was also observed. It seems possible that elevation of C3a may be one of the underlying causes for the appearance of pruritus, and that Neurotropin may exert its antipruritic effect through suppression of the activation of C3 in patients undergoing hemodialysis.

Bradykinin↗

PubMed1988

The metabolism of 1-methylhydantoin via 5-hydroxy-1-methylhydantoin in mammals.

The metabolic pathway of 1-methylhydantoin (2) via 5-hydroxy-1-methylhydantoin (3), methylparabanic acid (4) and N5-methyloxaluric acid (5) proved to be a major and general one in mammals. Hence the formation of (3), which has not been detected in normal tissue, is likely to be indirect in inflamed tissue, probably depending on the arising formation of (2) from creatinine (1).

Animals↗

PubMed1983

Seasonal variations of total histamine in patients with seasonal allergic rhinitis.

Seasonal variations of total blood histamine were examined in twenty patients with seasonal allergic rhinitis (Japanese cedar pollinosis). In blood specimens taken in the pollen season of 1978, the symptom-free season of 1978, and the pollen season of 1979, the mean values of blood histamine were 61.6, 50.0 and 84.2 ng/ml respectively. The differences in blood histamine levels between the pollen season of 1978 and the symptom-free season of 1978 and between the symptom-free season of 1978 and the pollen season of 1979 were statistically significant. In the symptom-free season of 1978, the blood histamine levels of twenty normal subjects were also examined; the mean value was 58.2 ng/ml. The blood histamine levels of the patients in the symptom-free season were not statistically different from those of the normal subjects.

Adult↗

PubMed1983