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Biomedical subjects

T Morishima

Publications and source records attributed to T Morishima.

15 recordsLinked to original sources

Counterregulatory system in an artificial endocrine pancreas. Glucose infusion algorithm.

An artificial endocrine pancreas has been developed by adding a glucose infusion system to the artificial beta cell system. In this computer algorithm, glucose is infused on the basis of proportional and derivative actions to blood glucose concentration with the time delay constant between blood withdrawal and initiation of glucose infusion. When glucose was infused on the basis of proportional action with a 20-minute time delay, the prompt restoration to normoglycemia from the hypoglycemic state with a smaller amount of glucose was shown in depancreatized dogs. These results indicate that the artificial endocrine pancreas thus prepared is not only a useful device to safely control blood glucose, but also is an efficient research tool for the analysis of the blood glucose regulatory mechanism.

Animals

Acute infantile gastroenteritis caused by rotavirus in Japan.

We had an outbreak of acute infantile gastroenteritis accompanied by milky-white stool (called Hakuri in Japanese) during the winters of 1976 and 1977. Stool specimens collected from 72 cases of Hakuri were studied by negative-staining electron microscopy. Rotavirus was detected with a very high frequency (89%). Rotavirus obtained from one of the patients was isolated and passaged in cultures of primary human embryonic kidney cells. Viral antigens could be detected in the cytoplasm of the cells by indirect immuno-fluorescence. The fluorescence-positive cells increased in number with repeated passage. Serum anti-viral activities in 11 patients were titrated by indirect immuno-fluorescence, using the cells infected with the passaged rotavirus. All 11 patients developed IgM responses in the convalescent phase. However, in 4 of the 11 patients, no IgG responses were detected even 2--3 weeks after the onset of illness. The reinfection which has occasionally be seen in our country may be related to these poor IgG responses.

Acute Disease

Pagetoid malignant melanoma and lentigo maligna melanoma of toe. A study with the fluorescence method (Falck and Hillarp).

Two cases of malignant melanoma on the toe of middle-aged women were examined chiefly by the fluorescence method of Falck and Hillarp. In one of the patients, histopathology of the pigmented tumor on the left middle toe was a Pagetoid (superficial spreading) melanoma in situ, and the subungual granulomatous lesion on the right great toe in the other patient was a lentigo maligna melanoma. On fluorescence microscopy, characteristic findings of the pigment cells lying in the epidermis of both types may be summarized as follows: In the Pagetoid melanoma, the melanoma cells are ovoid, lack dendritic processes, and emit specific yellow fluorescence. In the lentigo maligna melanoma, the pigment cells clearly show dendritic processes, and emit specific green fluorescence.

Female

Meningeal exudate cells in vaccinia meningitis of mice: role of local T cells.

Intracerebral inoculation of vaccinia virus into adult DDD mice produced intensive meningitis several days after infection. The inflammatory reaction could be quantitated by counting cells obtained from this inflammatory lesion. The local virus titer increased until day 5 and subsequently decreased rapidly with time. Concomitant with this titer decrease, numerous meningeal exudate cells appeared in the lesion. The cytotoxic activity of these cells against vaccinia virus infected cells was studied after removal of glass-adherent cells. The results showed that these meningeal exudate cells possessed cytotoxic activity against the virus-infected cells and moreover inhibited plaque formation by vaccinia virus. The magnitude of this activity was much larger than that of spleen cells obtained from the same animals. After treatment with antithymocyte serum, or with antitheta serum plus complement, the meningeal cells lost their inhibitory activity, suggesting that the cells which exerted the effect were mainly T lymphocytes. The meningeal exudate cells obtained on day 7 postinfection were further characterized. A greater part, approximately 80%, of the cell population was composed of theta-positive cells. Less than 1% carried immunoglobulin, 7% possessed neither theta antigen nor immunoglobulin on the surface, and 12% represented glass-adherent cells.

Animals

Pigmented nevus divided between recipient and donor sites by intermediate skin grafting procedure: a study with fluorescence method (Falck & Hillarp).

Pigment freckles seen in donor and recipient sites at intermediate skin grafting were studied, chiefly by means of Falck & Hillarp's fluorescence method, with the following results. (1) An important role is played by the regenerative eccrine sweat ducts in the mechanism of recurrence of so-called "lentigines" after incomplete removal. (2) Junctional activity, not associated with the regeneration of epidermal appendages, can recommence in the epidermis of intradermal nevi. (3) B-type nevus cells once again actively produce melanin. (4) Specific fluorescence was observed corresponding to the melanin granules distributed in the manner of "nuclear caps" in keratinocytes around junctional activities. This latter finding may indicate that melanosomes which still contain DOPA are transferred from melanin-producing cells to keratinocytes.

Adult

Adrenergic nerve innervation of the human cutaneous glomus.

Adrenergic (monoaminergic) nerve innervation of cutaneous glomus from the human thumb was examined by the fluorescence method of Falck and Hillarp for the demonstration of monoamines. The main anastomotic vessel (Suquet-Hoyer canal) was found to possess a pattern specific for nerve innervation. The Suquet-Hoyer canal was surrounded like a sheath by numerous thin adrenergic fibers, which were distributed like threads around a bobbin. These nerve fibers are superimposed directly on the outer surface of the glomus cell layer, not penetrating between these cells. They show varicose axon ramifications.

Adrenergic Fibers

Melanin-producing cells seen in neurofibromatous lesions of Recklinghausen's disease -- a study with fluorescence method (Falck and Hillarp).

A case diagnosed to have the lesion of pachydermatocele type of Recklinghausen's disease in a 28-year-old female was studied mainly by means of fluorescence method (Falck and Hillarp). Histopathological examination revealed that the lesion was composed of Ota's nevus-like changes in the epidermis to the middermis and of proliferation of neurofibromatous tissues coexisting with melanin-producing cells in the lower dermis to the subcutaneous adipose tissue. Melanin-producing cells in the neurofibromatous lesion were shown by fluorescence method to have characteristics of nevus cells rather than of melanocytes. Innervation of monoaminergic and cholinergic nerves was not found to the arteries in neurofibromas. These findings are thought to suggest that the abnormalities of not only Schwannian cells and melanocytes of neural crest origin but also of nevus cells and autonomous nerves of neural crest origin are related with the pathogenesis of pachydermatocele type of Recklinghausen's disease.

Adrenergic Fibers

Clinical and histopathological studies on spotted grouped pigmented nevi with special reference to eccrine-centered nevus.

Clinical and histopathological studies on 16 cases of spotted grouped pigmented nevus resulted in this disease being classified into at least three types. Characteristic findings of each type are described in this paper, in particular that nevus cell proliferation, a finding common to each type, is closely related pathogenetically to skin appendages, especially with eccrine sweat ducts. The eccrine-centered nevus characterized by Mishima corresponds to the third type, according to the present author's classification. The similar characteristic histopathological finding was also observed in a specimen taken from a black papule in a case of giant pigmented nevus with disseminated pigment cell nevi. We would like to consider that the cells of eccrine-centered nevus are derived from nevoblasts present in the walls of sweat ducts.

Adolescent

Mechanism of recurrence of pigmented nevi following dermabrasion.

A study was made of pigment freckles which recur after skin abrasion of spotted grouped pigmented nevi, according to the lapse of time, chiefly by means of the fluorescence method of Falck and Hillarp. The mechanism of recurrence is summarized as follows. Nearly simultaneously with the epidermal regeneration, dendritic melanin-producing cells derived from hair follicles and eccrine sweat ducts appear in the basal and prickle-cell layers of epidermis. These cells then create junction activity in the basal layer of epidermis, in the hair follicles and in the eccrine sweat duct walls. Finally, these nevus cells drop off into the underlying layer of scar tissue along the epidermal appendages. The dendritic melanin-producing cells seen in the early regenerative pigment freckles were thought to be incompletely differentiated nevus cells in the pre-stage of junction nevus formation. Appearance of dendritic melanin-producing cells and formation of junction activity in the eccrine sweat duct walls suggest the following possibilities. (1) In the cases of spotted grouped pigmented nevus which we studied, nevus cell proliferation also occurred eccrine-centrically on pathogenesis. (2) An important role is played by the eccrine sweat ducts in the recurrence of ordinary pigmented nevi after incomplete removal. (3) Eccrine-centered nevus cells are derived from nevoblasts in the eccrine sweat duct walls.

Adult