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Biomedical subjects

R Igarashi

Publications and source records attributed to R Igarashi.

64 records · Page 4Linked to original sources

Immunofluorescent studies of complement C3 in the hair follicles of normal scalp and of scalp affected by alopecia areata.

The deposition of complement C3 in the hair follicles of scalps of 4 normal subjects and of the affected parts of 9 patients with alopecia areata was found by the direct immunofluorescent methods. No deposition of immunoglobulins (IgG, IgA, IgM, IgD and IgE) was found. In the normal scalps, complement C3 was found to be deposited in the hyaline membrane of the hair bulb and in the internal layer of connective tissue sheath at the lower about 2/3 transient portion of anagen follicles, and in the thickened hyaline membrane of the catagen follicles. The deposition of complement C3 was also found in the anagen and catagen-like hair follicles even in the patients with alopecia areata, which was similar to the finding in the normal scalps. From the fact that the deposition of complement C3 was found chiefly in the transient portion of the hair follicles of the normal scalps, and that the behavior of deposition of complement C3 reflected the morphological state of hair follicles in each stage of the hair cycle, even in alopecia areata, complement C3 may be intimately related to the hair cycle, even though its significance is as yet unknown.

Adult↗

An immunofluorescence study of light chain in pemphigus.

Immunofluorescence studies were made on light (L) chain of immunoglobulins in patients with pemphigus. These patients fell into two groups: a subcorneal bulla group, consisting of 10 patients with Senear-Usher syndrome, and one with pemphigus foliaceus, and a suprabasal bulla group consisting of 8 patients with pemphigus vulgaris. In the former group there was deposition of L chains of either type alone in the intercellular spaces of the upper epidermis: kappa type alone in 9 and lambda type alone in 2 patients. Deposition of L chains of both types was observed in the intercellular spaces of the lower epidermis in all patients of the latter group. No significant difference existed between groups as to the titre of circulating intercellular antibodies of either type. Some comments are made on the significance of the L chain of immunoglobulins in a pemphigus.

Adolescent↗

Prolidase deficiency with imidodipeptiduria. A familial case with and without clinical symptoms.

A 23-year-old female with chronic leg ulcer was found to excrete the massive imidopeptides, among which Asp-Pro, Glu-Pro and Gly-Pro were identified. Essentially no prolidase activity was measured in her erythrocytes, while prolinase activity was within a normal range. Her 26-year-old brother also showed imidopeptiduria and erythrocyte prolidase deficiency, but no clinical symptoms were observed. Erythrocytes from her father and 30-year-old brother, who excreted no significant amounts of imidodipeptides, showed intermediate values for the prolidase activity between those for the patient and for normal adults, suggesting that they are heterozygous for this autosomal recessive disorder.

Adult↗

Administration of optimum sustained-insulin release PLGA microcapsules to spontaneous diabetes-prone BB/Wor//Tky rats.

To show the possibility of sustained-release insulin formulation composed of PLGA, the optimum one was administered to BioBreeding rat, a model of spontaneous type I diabetes mellitus (IDDM). Every 2 weeks subcutaneous administration made their blood glucose level depend on the insulin release and food intake. However, all of them kept alive with little change or rather a little gain in body weight. Furthermore, some of pregnant rats with intermittent treatment bore fetuses, although additional insulin therapy seemed necessary. Therefore, the formulation could become a new tool as a provider of basal insulin for IDDM patients.

Animals↗

Application of a drug delivery system to a steroidal ophthalmic preparation with lipid microspheres.

The applicability of a drug delivery system to an ophthalmic preparation was examined using lipid microspheres containing hydrocortisone 17-butyrate 21-propionate (HBP). A 3H-labelled HBP ophthalmic suspension and 3H-labelled HBP lipid microspheres were applied to rabbit eyes, which were then enucleated at fixed intervals to determine the level of 3H-labelled HBP in ocular tissues. The lipid microspheres were shown to deliver the drug to the anterior ocular tissues more effectively than the ophthalmic suspension. It is suggested that a lipid microsphere ophthalmic preparation of various lipophilic drugs including steroids may be useful as a drug delivery system for ophthalmic therapy.

Administration, Topical↗

Lecithinized ascorbic acid (PC-AS) effectively inhibits murine pulmonary metastasis.

In order to enhance the lipophilicity and develop the efficacy of ascorbic acid (ASA), we synthesized lecithinized ascorbic acid (PC-AS), in which a lecithin was covalently bound to ASA. Its pharmacological activity was also evaluated. The IC50 value of scavenge superoxide anions generated from hypoxanthine in combination with xanthine oxidase, indicated that the antioxidative activity of PC-AS (IC50; 22.19 microM) was about 60% of that shown by ASA (IC50; 13.35 microM). Also, PC-AS suppressed in vitro cell growth of Meth A-T, a highly metastatic cell line established by us. Although its potency (IC50; 110.0 microM) was a little lower than that of ASA, dramatic suppression was observed under serum-free culture conditions (IC50; 13.0 microM). In addition, N-acetylcysteine (NAC), an antioxidant, showed an additive inhibitory effect on cell growth in combination with PC-AS and ASA. Biodistribution studies revealed that PC-AS persisted longer in the blood (AUC0-240 min; 182.8 nmole min ml-1) than ASA (AUC0-240 min; 79.35 nmole min ml-1). It should be noted that intravenous preadministration of PC-AS significantly and dose-dependently reduced the number of colony formation in an experimental murine pulmonary metastasis model. ASA had little effect. [3H]-labeled Meth A-T cells predominantly accumulated in the lung, metastatic target organ, which was reduced by PC-AS. Our in vivo study showed that PC-AS could not totally prevent pulmonary invasion of Meth A-T cells, however, PC-AS effectively inhibited the number of metastatic colony formation. PC-AS's potency was superior to that of unmodified ASA. These findings might be in part ascribed to changes to lecithinization-induced biodistribution, antioxidative activity and cytotoxicity.

Animals↗