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Biomedical subjects

S Ofuji

Publications and source records attributed to S Ofuji.

At least 55 records · Page 3Linked to original sources

Suppressed cell-mediated immunity associated with eczematous inflammation.

In order to determine if an eczematous inflammation could have any influence upon already established cell-mediated immune reactivity, a widespread allergic as well as primary irritant, eczematous dermatitis was produced in tuberculin-sensitive guinea pigs. Their tuberculin reactivity was significantly suppressed both by allergic contact dermatitis due to dinitrochlorobenzene and by primary irritant dermatitis due to croton oil. After the dermatitis had subsided, tuberculin reactivity was restored to approximately the same level as before the induction of the dermatitis, which suggests that the suppression is temporary.

Animals↗

Early changes in human epidermis following thermal burn: an electron microscopic study.

Early alterations in the epidermis of human volunteers following 60 degrees and 95 degrees C burns were studied by means of electron microscopy. The blister was induced at 30 seconds following a 60 degrees C burn for 1 and 3 minutes by disintegration of the basal cells just above the basement membrane, and, in addition, for 3 minutes by disruption of the intercellular bridges adjacent to the desmosomes in the suprabasal cells. The keratinocytes of the separated epidermis revealed intracytoplasmic vacuoles, widening of the intercellular spaces and, in some cells, vacuolization of the mitochondria. At 30 seconds following a 95 degrees C burn for 3 seconds, the blister was induced by complete breakage of the basal and suprabasal cells which demonstrated karyorrhexis, aggregated tonofibrils and breaks in the plasma membrane. The keratinocytes of the blister roof showed aggregation of the tonofibrils at the periphery, and vacuolization of mitochondria and endoplasmic reticulum. The desmosomes and basement membrane revealed no alterations with 60 degrees and 95 degrees C burns.

Burns↗

Abnormal vascular reactions in atopic dermatitis.

Vascular reactions to mechanical stroking, topical application of nicotinic acid ester, and methacholine chloride were examined in both the normal and abnormal skin of 100 patients with atopic dermatitis and 20 patients with allergic contact dermatitis. White dermographism, nicotinic acid blanching, and delayed blanch with methacholine consistently occurred in areas of skin with eczematous change of patients with atopic dermatitis and those with allergic contact dermatitis. Normal skin of atopic patients did not show the abnormal vascular reactions. It is suggested that white dermographism, nicotinic acid blanching, and delayed blanch with methacholine seen in atopic dermatitis are secondary phenomena that give no definite information concerning the diagnosis of this disease.

Adult↗

Changes in adenine nucleotide and mitochondrial metabolism of the kidney of burned rats and their relation to insulin.

In rats with third-degree burns, the blood glucose level increased remarkably, with a concomitant suppression of insulin secretion from the pancreas after an oral glucose load. The energy charge (ATP + 1/2 ADP/ATP + ADP + AMP) levels of the kidney decreased to 0.659 as compared with 0.858 of controls at 8 hr after the burn (p less than 0.001). The phosphorylative activity of the kidney mitochondria fell to one third of controls at 8 hr after the burn (p less than 0.001), and that of heart mitochondria decreased to approximately 70% (p less than 0.005); the fall in liver and brain was less remarkable. The decrease in mitochondrial phosphorylative activity was accompanied by a reduction in the respiratory control ratio, P/O ratio, and state 3 respiration. The concentrations of cytochrome a(+a3) in the kidney mitochondria decreased to 69.9% of controls at 8 hr after the burn (p less than 0.001), those of cytochrome b to 82.6%, and those of cytochrome c + c1 to 75.3% (p less than 0.001). The decreased energy charge and oxidative phosphorylation of the kidney in burned rats were remarkably restored by subcutaneous administration of insulin. It is suggested that a reduction in insulin secretion from the pancreas may play an important role in initiating an impairment of adenine nucleotide and mitochondrial metabolism of the kidney.

Adenine Nucleotides↗

Trichophytin contact sensitivity in patients with dermatophytosis.

Trichophytin contact sensitivity was investigated in patients with dermatophytosis by patch testing with highly concentrated purified trichophytin on partially stripped skin. The lack of primary irritant reactions was confirmed on the skin of children. Positive patch tests were noted in 113 of 178 patients (63.5%). However, there was a great difference in the incidence of trichophytin contact sensitivity between cases with different clinical types. The highest frequency of positive patch tests was obtained in patients with the vesiculobullous type of tinea pedis (83.3%). In contrast, a very low incidence was noted in patients with tinea corporis (37%) and the squamous hyperkeratotic type of tinea pedis (36%). Causative organisms and the age and sex of the patients did not show a relationship with the reactivity. A diminished incidence of positive reactions was noted in atopic individuals and in patients seen in winter. Patients who had persistent or recurrent infections for a long period of time, especially those having inflammatory lesions, had a higher frequency of positive patch tests.

Adolescent↗

Leukotactic properties of soluble substances in psoriasis scale.

In an attempt to elucidate the mechanisms underlying the production of transepidermal migration of leukocytes toward the stratum corneum in psoriatic lesions, the chemotactic properties of soluble substances in psoriasis scales were examined by a modified Boyden's chamber. All crude extracts of horny tissues studied, i.e. callus, scales of exfoliative dermatitis and of psoriasis vulgaris, showed chemotactic activity for human peripheral blood leukocytes. But only the chemotactic activity of the psoriasis scale extract was highly potent. This was greatly reduced after dialysis. Fresh serum was not required to manifest the chemotactic activity. By Sephadex G-200 chromatography, the scale extracts from psoriasis vulgaris and pustular psoriasis had potent activity eluted near the cytochrome C marker. The same fractions of other horny tissue extracts, bacterial filtrate prepared from cultured psoriasis scale fragments, and serum did not show such potent activity. On the basis of analysis by gel filtration and recent findings of immunopathological studies, a postulate was made that a complement derived chemotactic factor, possibly a C5 cleavage product, developed as a result of antigen-antibody reaction in the stratum corneum of psoriatic lesions.

Aged↗

Primary eruption of prurigo simplex subacuta.

28 patients with typical picture of prurigo simplex subacuta were examined for the primary eruption. In all patients, the first visible lesion was a papule, at the top of which a vesicular element was never seen. 46 biopsy specimens of the initial eruption were serially sectioned. The histological changes were found in connection with hair follicles, which consisted of spongiosis and mononuclear cell migration at the follicular epidermis and perifollicular infiltrates of mononuclear cells.

Adult↗

The fate of tetrachlorosalicylanilide in photosensitized guinea pigs.

The distribution and fate of 3, 3', 4', 5-tetrachlorosalicylanilide (TCSA) in photosensitized guinea-pig skin following topical application at varying times was investigated by fluorescence microscopy in unfixed, frozen sections. When the site to which TCSA had been applied was irradiated with long-wave UV light, TCSA was detected in the entire epidermis only 3 days after application and in the horny layer up to 10 days. Unless TCSA-treated sites were exposed to light, TCSA was still recognized in the entire epidermis 10 days after application and in the horny layer even at 3 weeks. The irradiated photosensitized guinea pigs in the present study eliminated TCSA more rapidly than normal control animals in our previous work. The mechanism of persistent light reaction was discussed and we concluded that TCSA can remain in the skin for a long time, because it is a prohapten, not a hapten.

Animals↗

Patch test reactions to human dander in atopic dermatitis.

Patch tests reactions to human dander were positive in 120 of 181 (66%) patients with atopic dermatitis, in two of 28 (7%) patients with allergic contact dermatitis, and in one of 31 (3%) normal controls. The frequency of positive reactions was significantly higher in patients with atopic dermatitis. The reactions consisted of erythema and papules, which histologically showed an eczematous change at the upper parts of hair follicles. There was significant correlation between patch test reactions to human dander and delayed intradermal reactions to the same substance in atopic patients. It is suggested that certain patients with atopic dermatitis exhibit contact hypersensitivity to human dander. Whether or not the hypersensitivity has any relationship to the pathogenesis of the dermatitis was not determined in this study.

Adolescent↗

Pustular patch test reactions in atopic dermatitis.

Pustular patch test reactions to 5% nickel sulfate were regularly produced in patients with atopic dermatitis when patches were placed over areas of skin with (a) follicular papules, (b) erythema, (c) lichenification, and (d) minimal trauma. The pustular patch test reactions seldom occurred in the normal-appearing skin of these patients. However, if the skin was traumatized prior to the patch test, the reaction was produced in the normal-appearing skin of atopic as well as control individuals. No pustular reactions occurred in the follicular lesions of keratosis pilaris, supporting the view that follicular lesions of atopic dermatitis differ from keratosis pilaris. It is suggested that pustular patch test reactions are caused by primary irritation.

Adult↗