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Biomedical subjects

M Oguchi

Publications and source records attributed to M Oguchi.

At least 109 records · Page 6Linked to original sources
PubMed1981

Ultrastructural studies of spontaneously regressing plane warts. Macrophages attack verruca-epidermal cells.

Plane warts were examined at the earliest phase of spontaneous involution using an electron microscopy. Macrophages outnumbered lymphocytes in invading the epidermis. Lymphocytes exhibited pseudopods on the surface which occasionally reached into the epidermal cells. The cell membranes of both macrophages and epidermal cells frequently disappeared on the contacting surface and on occasion part of the cytoplasm and even the nucleus of macrophages invaded the epidermal cells. The macrophages showed an independent partial loss of their cell membranes with a subsequent outpour of their contents. This ultrastructural feature indicates that in spontaneously regressing plane warts the depressed membrane stability of macrophages as observed in BCG and other-induced tumor cell destruction also occurs in the presence of lymphocytes. Therefore, the spontaneous involution may represent a rejection phenomenon.

Adult↗
PubMed1981

Ultrastructural studies of spontaneously regressing plane warts. Langerhans cells show marked activation.

Ultrastructural changes in Langerhans cells during spontaneous involution of plane warts were examined. In areas with activated macrophages and epidermal cell interaction, Langerhans cells showed signs of enhanced cellular activity with an increased number of Langerhans cell granules, as in contact dermatitis. The fine structure of Langerhans cell granules, however, was unusual in that the vesicular portion was surrounded by a membrane, and this portion frequently occurred independently taking the shape of a loop.

Dermatitis, Contact↗
PubMed1980

The phenomenon of spontaneous regression of numerous flat warts: immunohistological studies.

The phenomenon of systemic regression of numberous flat warts takes place within one month after the sudden onset of spontaneous inflammation in them. In other types of warts, we have never observed such a dramatic regression. We performed a histological study in a total of 51 cases showing this spontaneous inflammation in their flat warts and found a massive mononuclear cell infiltration in all. In 9 cases, a histological study for basophils was carried out but failed to show them among the infiltrating cells despite the strong histological resemblance to contact allergy. An immunofluorescence technique performed in 16 cases demonstrated no specific deposits of immunoglobulins and complement in such inflamed wart tissues except for those which appear to be only a secondary event to inflammation per se. These immunopathological findings further substantiate the concept that cell-mediated mechanisms rather than humoral immunity play a major role in this phenomenon of sudden regression of numerous flat warts.

Adolescent↗
PubMed1980

Ultrastructural studies of allergic contact dermatitis in man. Infiltrating cells at the earliest phase of spongiotic bulla formation.

The kind and fine structure of mononuclear cells appearing in the epidermis at about 6 h of allergic contact dermatitis were examined by electron microscopy. They were monocytes and lymphocytes, the number being about equal. The ultrastructure of monocytes was that described for normal ones in blood, and apparently actively moving, streching the intercellular connections of the keratinocytes. Lymphocytes displayed a round or oval nucleus with some electron-dense cytoplasm which contained ribosomes and polysomes but only occasional mitochondria and Golgi complexes.

Adolescent↗
PubMed1980

True histiocytic lymphoma.

An 86-year-old man had true histiocytic lymphoma of the skin. Diagnosis was established by the following findings: (1) typical histological features, (2) lack of receptors on tumor cells for immunological surface markers, and (3) active phagocytic function. Electron microscopic studies indicated cytoplasmic multivesicular bodies in the tumor cells. Multivesicular bodies have been reported in histiocytic proliferative disorders and may be of diagnostic value in cases of true histiocytic lymphoma.

Aged↗
PubMed1979

Hexokinase of Angiostrongylus cantonensis: presence of a glucokinase.

1. Angiostrongylus cantonensis contains a glucokinase which was isolated by DEAE-cellulose column chromatography. 2. This enzyme has a much higher affinity toward glucose (apparent Km, 0.2 mM) than fructose (apparent Km, 85 mM). Glucose-6-phosphate (10 mM) does not inhibit glucose phosphorylation. 3. Molecular weight obtained by a molecular sieve chromatography (60,000) is also close to the value of mammalian glucokinase. 4. While Vmax value for mannose is one-third smaller than that for glucose, Km for mannose is rather lower than that for glucose. 5. In addition to the cytosol enzyme, a particle bound hexokinase is found in the worm.

Angiostrongylus↗
PubMed1978

Ultrastructural studies of epidermis in acute radiation dermatitis. Basal lamina thickening and coated vesicles.

Fine structural changes of keratinocytes by X-ray were examined in normal skin area around a lesion of Bowen's disease. The area was exposed to about 6000 r over 28 days. The findings were: a decreased number of desmosomes and microvilli, formation of cytoplasmic vaculoes with or without membrane, perinuclear aggregation of tonofibrils, intracytoplasmic desmosomes and gap junction, cytoplasmic occurrence of dense bodies, lipid droplet and glycogen particles, changes in mitochondria, endoplasmic reticulum and Golgi complex, and deep invagination of the nuclear membrane. Besides these, conspicuous in the present study were, changes in the basal lamina which consisted of multiplication, thickening and occasional detachment from basal cells, and frequent occurrence of coated vesicles along with the basal lamina alteration. Possible exocytotic nature of coated vesicles in X-ray irradiated keratinocytes is discussed.

Aged↗
PubMed1978

An ultrastructural study of the epidermis in hyperkeratosis lenticularis perstans.

A 60-year-old Japanese man contracted hyperkeratosis lenticularis perstans (Flegel). Biopsy specimens of the keratotic papules on the dorsa of the feet were studied with electron microscopy. An increase in the number of membrane coating granules, keratohyalin granules and tonofilaments was the most prominent feature of the keratinocytes underlying the keratotic papule. However, in the area just above the cone-shaped dermal infiltration, membrane coating granules were absent and keratohyalin granules and tonofilaments were poorly developed.

Arm↗