Biomedical subjects

Y Asada

Publications and source records attributed to Y Asada.

At least 235 records · Page 13Linked to original sources

PubMed1991

Effects of cepharanthin on neutrophil chemotaxis, phagocytosis, and reactive oxygen species generation.

The effects of cepharanthin on inflammatory parameters such as neutrophil chemotaxis, phagocytosis and reactive oxygen species (ROS) generation, were examined. Cepharanthin significantly decreased the levels of O2-, H2O2, and OH. generated by neutrophils. H2O2 and OH. generated in a cell-free, xanthine-xanthine oxidase system were also reduced in the presence of cepharanthin. However, the drug did not affect neutrophil chemotaxis or phagocytosis. The present study indicates that cepharanthin is an effective ROS scavenger, exerting its anti-inflammatory action by reducing the potent ROS species excessively generated in tissues and organs, especially at the sites of inflammation.

Alkaloids↗

PubMed1991

Localized pemphigoid shares the same target antigen as bullous pemphigoid.

A case of localized pemphigoid is described in which the lesions were only on the lower legs. Immunoblotting of the patients' serum reacted with a 240-kDa polypeptide identical to one of the bullous pemphigoid antigens. IgG1 was detected in the lesional skin and IgG1 and IgG4 in the patient's serum. These observations suggest that the immunopathological mechanisms in the blister formation in localized pemphigoid are similar to those found in more widespread bullous pemphigoid.

Aged↗

PubMed1991

Effects of azelastine on neutrophil chemotaxis, phagocytosis and oxygen radical generation.

The effects of azelastine, an orally active anti-allergic drug, on several inflammatory parameters of human neutrophils, including human neutrophil chemotaxis, phagocytosis and generation of reactive oxygen species (ROS), was examined. ROS generated in a cell-free, xanthine-xanthine oxidase system was also assessed. The species investigated were superoxide radical anion (O2-), hydrogen peroxide (H2O2) and hydroxyl radical (OH.). Azelastine significantly inhibited human neutrophil phagocytosis and the generation of O2-, H2O2, OH. by human neutrophils. However, the drug did not markedly affect human neutrophil chemotaxis or the ROS levels generated in the xanthine-xanthine oxidase system. The present study indicates that azelastine may exert an anti-inflammatory action by inhibiting human neutrophil phagocytosis as well as oxygen radical generation at the sites of inflammation.

Cell Movement↗

PubMed1991

Medullary bone of piglets.

The bone marrow is commonly present in the medullary cavity of long bones in most mammals at birth. In the present study, the persistence of the osseous tissue was examined in the medullary cavities of piglet bones at and after birth. Immediately after birth, medullary cavities of long bones were almost completely filled with the spongy bone. The persisted spongy bone, i.e., medullary bone was prominent in younger pigs but decreased with advance in age. By 90 days of age, the medullary bone almost disappeared to form the extended medullary cavity. During the disappearing process of the medullary bone, osteoclasts showed significant increase in size and number (p less than 0.05). In irregular and flat bones, osseous trabeculae of the medullary bone became slender with age. The extramedullary hematopoiesis in the liver and spleen was very active till 30 days of age. This may suggest that the persistence of the medullary bone narrows the medullary cavity to cause poor medullary hematopoiesis and is compensated by extramedullary hematopoiesis. The relationship among the medullary bone, extramedullary hematopoiesis and piglet anemia was discussed.

Aging↗

PubMed1991

Chronic actinic dermatitis: a time course study of histopathological changes.

We report herein a case of chronic actinic dermatitis in which histopathological changes were observed on several occasions during the course of 2 years. The findings were quite different among stages of the eruption. At a half year after the appearance of the lesion, histological findings revealed eczematous changes. However, gradually a granulomatous change appeared with histiocytes and giant cells. Although the mechanism of histogenesis is not clear, the appearance of histiocytic giant cells seems to be unusual in chronic actinic dermatitis.

Aged↗

PubMed1991

The hairless guinea pig as an experimental animal for photodermatology.

Photobiologic reactions to various modalities of ultraviolet light (UVL) irradiation were evaluated in the recently identified hairless guinea pig, Crl: IAF(HA)BR, a mutant from the Hartley strain. The cutaneous changes were observed macro- and microscopically. The animal developed similar but somewhat stronger reactions than the Hartley guinea pig to the UVB irradiation and topical and systemic PUVA treatments. The density of the epidermal Langerhans cell of the hairless guinea pig was significantly higher than that of the hairy strain. The photoallergic contact sensitization was easily induced by tetrachlorosalicylanilide. These results indicate that the hairless guinea pig can be used as an animal model for photobiologic and photoimmunologic investigations.

Animals↗

PubMed1991

T-cell subsets in drug-induced toxic epidermal necrolysis. Possible pathogenic mechanism induced by CD8-positive T cells.

A patient with bromisovalum-induced toxic epidermal necrolysis showed pronounced delayed hypersensitivity to bromisovalum by patch testing. Biopsy specimens from the cutaneous lesion and the site of the positive patch test reaction were analyzed and compared immunohistologically. The findings were similar: most of the mononuclear cells disposed along the dermoepidermal junction and migrating into the epidermis were CD8-positive lymphocytes, whereas the dermal inflammatory infiltrates were composed predominantly of CD4-positive lymphocytes. This case showed the potential usefulness of patch testing in evaluating cases of toxic epidermal necrolysis. We believe that delayed hypersensitivity plays a crucial role in the development of drug-induced toxic epidermal necrolysis. Furthermore, potential effector cells with phenotypic characteristics of CD8-positive lymphocytes (suppressor/cytotoxic T cells) seem to represent important mediators of the epidermal damage of the cutaneous lesion in our case.

Adult↗

PubMed1990

The inhibition of free radical generation by human neutrophils through the synergistic effects of metronidazole with palmitoleic acid: a possible mechanism of action of metronidazole in rosacea and acne.

Metronidazole is clinically effective in treating not only rosacea but also acne inflammation. Yet it is generally considered not to be very effective in inhibiting the growth of anaerobic Propionibacterium acnes. We report here our investigation into the synergistic effects of metronidazole and palmitoleic acid on the anaerobic growth of P. acnes as well as on human neutrophil functions, including the generation of reactive oxygen species (ROS). Both metronidazole and palmitoleic acid, when used alone, only slightly inhibited the growth of P. acnes, and no significant decrease in human neutrophil functions, including the generation of ROS, was observed. But metronidazole used in the presence of palmitoleic acid markedly inhibited the anaerobic growth of P. acnes and decreased ROS generation by neutrophils. However, ROS generated in the xanthine-xanthine oxidase system were not affected. Metronidazole was shown to be clinically effective by decreasing neutrophil-generated ROS at the sites of inflammation with the aid of palmitoleic acid, which is generally present in human skin. By inhibiting oxidative tissue injury under in vivo conditions, treatment with metronidazole results in remarkable improvement of rosacea and acne.

Acne Vulgaris↗

PubMed1990

Screening of basidiomycetes for lignin peroxidase genes using a DNA probe.

Basidiomycetes were screened for lignin peroxidase (LPO) genes using a DNA probe prepared from the LPO restriction fragment of Phanerochaete chrysosporium. Southern blot analysis showed restriction fragments of chromosomal DNA of Bjerkandera adusta and Coriolus consors hybridized with the probe. Bjerkandera adusta produced LPO in a glucose-peptone medium. Ion-exchange chromatography showed that this fungus produced multiple molecular forms of LPO. One of the enzymes, LPO-2, was purified and characterized. The molecular weight of LPO-2 was 41,000 with a pI of 4.2. Spectral analysis demonstrated that LPO-2 is a haem protein. The enzyme cleaved lignin model dimers mainly at the C alpha-C beta position of the side chain. The LPO-2 exhibited close similarity to LPOs of P. chrysosporium with respect to their basic properties.

Basidiomycota↗

PubMed1990

Aortic endothelial cell damage induced by beta-VLDL and macrophages in vitro.

We performed an in vitro study to assess damage to swine aortic endothelial cells by rabbit beta-VLDL and/or rabbit peritoneal macrophages. Incubation of cultured aortic endothelial cells with beta-VLDL, macrophages, or macrophage lysate induced endothelial cell damage time- and dose-dependently as estimated by [3H]adenine release. Incubation of endothelial cells with both beta-VLDL and macrophages produced a synergistic effect on the increase of [3H]adenine release. Pretreatment of the endothelial cells with some kinds of antioxidants (probucol 50 micrograms/ml, vitamin E 50 microM, superoxide dismutase-polyethylene glycol 0.5 mg/ml, or catalase-polyethylene glycol 0.5-1.0 mg/ml) significantly prevented the endothelial damage by beta-VLDL or macrophage lysate. We conclude that beta-VLDL and/or macrophages could induce endothelial cell damage and that some kinds of antioxidants could prevent it.

Adenine↗

PubMed1990

Suppressive effects of linoleic acid on neutrophil oxygen metabolism and phagocytosis.

On the basis of recent reports that the proportion of linoleic acid (C18:2Cis 9,12), a free fatty acid, is markedly decreased in acne comedones and that tetracycline is effective against acne comedones by acting directly as an antioxidant on infiltrating neutrophils, we investigated the effect of linoleic acid on several inflammatory parameters of neutrophils, including neutrophil chemotaxis, phagocytosis, and generation of reactive oxygen species (ROS). Linoleic acid significantly decreased phagocytosis and the generation of O2-, H2O2, and OH.by neutrophils, whereas it did not significantly inhibit neutrophil chemotaxis or decrease the ROS levels generated in a cell-free, xanthine-xanthine oxidase system. The present study seems to suggest that decreased levels of linoleic acid in acne comedones contribute, in part, to the worsening of acne inflammation by the failure of low levels of linoleic acid to suppress neutrophil phagocytosis and ROS generation.

Acne Vulgaris↗

PubMed1990

A new method for simultaneous measurement of endogenous noradrenaline release and vascular responsiveness in perfused rabbit carotid arteries in vitro.

1. A new preparation for large arteries was tested for the simultaneous measurement of noradrenaline release and vasoconstrictor response induced by nerve stimulation in vitro. 2. Preparations of rabbit carotid artery with an outflow cannula were perfused with a modified Krebs-Ringer bicarbonate solution containing propranolol (3 x 10(-6) M) and cocaine (10(-6) M), to block beta-adrenoceptors and uptake-1, respectively. 3. The perfused carotid arteries were subjected to both transmural field stimulations (TFS) and exogenous noradrenaline administrations. To evaluate the preparation, we carried out the procedures in two control groups and a group with yohimbine (10(-7) M) treatment, respectively. 4. TFS over the range of 1.5-24 Hz caused a frequency-dependent pressor response. Yohimbine significantly increased the TFS-induced pressor responses. 5. TFS also caused frequency-dependent endogenous noradrenaline release. The endogenous noradrenaline release was significantly enhanced by yohimbine treatment. When noradrenaline release was expressed as release per stimulus, it was frequency-dependent in the group with yohimbine treatment but not in control groups. 6. Exogenous noradrenaline induced a dose-dependent pressor response. The exogenous noradrenaline-induced vasoconstrictor response was significantly diminished by yohimbine treatment. 7. It is concluded that this preparation can be effectively used to study drug effects on noradrenergic neurotransmission in relatively large arteries under various pathophysiological states by simultaneously measuring catecholamine release and vascular responsiveness.

Animals↗

PubMed1990

Vascular injuries induced by materials released from white mural thrombus and hypercholesterolemia in vivo.

Materials released from platelet-rich white mural thrombi into the arterial circulation and dietary hypercholesterolemia could cause endothelial injury and regeneration, and also smooth muscle cell migration and proliferation in vivo in the intima. In addition, a combination of these two factors showed an additive effect on the endothelial injury in vivo. Further experiments are in progress to clarify how high a level of serum cholesterol and/or oxidized LDL may be sufficient for endothelial injury using this in vivo model for the better understanding of detailed pathogenesis of atherosclerosis.

Animals↗

PubMed1990

A case of delayed hypersensitivity reaction following a sea urchin sting.

The case of a 28-year old woman with pruritic and erythematous eruptions on the knees and ankle about 10 days after being stung by sea urchin is reported. The spines of a sea urchin were ground, extracted and patch-tested, to which the patient showed a positive delayed skin reaction. Based on the clinical course and positive patch tests, it was concluded that the patient developed a delayed hypersensitivity reaction to the sea urchin's stinger.

Adult↗

PubMed1990

Bilateral pararenal lymphatic cysts associated with hypertension.

A case of bilateral pararenal lymphatic cysts is reported. These cysts surrounded the renal parenchyma in a multilobulated fashion and were contained in the intracapsular space. The lymphangiography showed the communication between cysts and lymphatic channels. Histopathological findings suggested the possible nature of this lesion to be congenital lymphatic anomalies.

Child↗

PubMed1990

[An immunohistochemical study on cell differentiation in the outer root sheath of the normal human anagen hair follicles with antikeratin monoclonal antibodies].

The expressions of several cytokeratins (CKs) in the outer root sheath (ORS) of the human anagen hair follicles were immunohistochemically studied using 11 antikeratin monoclonal antibodies (MoAbs) and 10 specimens from scalp. CKs 1, 10, 11, which are markers for differentiating keratinocytes, were exclusively found in the intermediate cells and the granular cells at the infundibulum. In cytokeratin expression, a distinct linear demarcation between the infundibulum and the isthmus was observed. Trichilemmal keratinization appeared to go in an inner-upward direction toward the hair canal. CK 19, a marker of undifferentiated stem cells, was found in outermost cells of the ORS at the isthmus and in some cells of the lower ORS. CK 16, a marker of hyperproliferative keratin, was detected in the outermost cells of the infundibulum and all the cells of the ORS below the isthmus. Therefore, the keratinocytes at the infundibulum may show a differentiation similar to that of the interfollicular epidermal keratinocytes. The ORS cells below the isthmus seem to move up to inner-upward direction along the hair axis with differentiation.

Antibodies, Monoclonal↗

PubMed1990

[Biochemical genetic marker of mouse salivary protein in mouse].

It has been reported by BALAKRSHANN and ASHTON that about 20-30 bands of human salivary protein separated by polyacrylamide gel electrophoresis (PH 8.0) were detected by staining with Coomassie brilliant blue R. Employing the same method, MATSUSHIMA discovered five main regions (I-V) in mouse salivary protein (Msp) separated by poly-acrylamide gel electrophoresis (PH 8.0). He also discovered distinctive features of biochemical genetic markers among each of the five regions. In this experimental study, we investigated biochemical genetic markers of Msp of C3H/HeJ, BALB/c, BALB/k and NOD/shi strains. The following were the results of the present study. 1) The results of C3H/HeJ and BALB/c mice were in accord with those of MATSUSHIMA's. 2) The BALB/k mouse showed the same results as the BALB/c the difference in sex of Msp-1 seemed to have no relation to H-2 complex. 3) With the NOD/she strain, Msp-3 showed the b-type, Msp-2 the a-type, Msp-1 the o-type showed no difference based on sex, that is to say, F-type in both male and female. Amylase-1 showed the b-type.

Animals↗

PubMed1990

[Investigation into the actual condition of physically handicapped children--specially the consciousness in parents].

The purpose of this paper was to investigate the dental situation of children who visited the pedodontics clinic of Nihon University at Dental-Hospital during the period from Jan. 1983 to Dec. 1987. The subject is the awareness in parents of 68 children who carried out the administration of medical care. The results were as follows. 1) Recently we observed that the ratio of physically handicapped children was was on the increase among the first visit patients. 2) The principal diseases of the physically handicapped children were cyclothymic, allergy and blood dyscreasia. 3) The majority of the patients visited for receiving caries treatment. 4) We presumed that the parents of the physically handicapped children showed deep concern for oral diseases.

Attitude to Health↗