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Y Asada

Publications and source records attributed to Y Asada.

At least 217 records · Page 12Linked to original sources
PubMed1992

Inhibition of neutrophil chemotactic factor production in comedonal bacteria by subminimal inhibitory concentrations of erythromycin.

The effect of 1/10 minimal inhibitory concentrations (sub-MIC) of erythromycin (EM) on human neutrophil chemotactic factor production in comedonal bacteria, Propionibacterium acnes strains, Propionibacterium granulosum strains and coagulase-negative staphylococcus (CNS) strains was assayed using the Boyden chamber method. Sub-MIC of EM significantly suppressed neutrophil chemotactic factor production in all strains of P. acnes, P. granulosum and CNS. Our results suggest that sub-MIC of EM may have an anti-inflammatory action by reducing the inflammatory capacity of comedonal bacteria in inflammatory acne.

Acne Vulgaris↗
PubMed1992

Contribution of the endothelium to intimal thickening in normocholesterolemic and hypercholesterolemic rabbits.

Endothelial cell injury is considered to be a primary event in the pathogenesis of atherosclerosis. In this study, we investigated the aortic intimal lesion after balloon catheterization in hypercholesterolemic and normocholesterolemic rabbits with or without probucol, an antioxidant. After deendothelialization, the rabbits were divided into four groups: 1) a control group fed a standard diet; 2) a probucol-treated group; 3) a cholesterol-fed group; and 4) a group fed a mixed cholesterol and probucol diet. Four animals from each group were killed at 2, 4, and 8 weeks after deendothelialization. The aortic segments of nonendothelialized areas, borderline areas, and uninjured areas were histologically and immunohistochemically examined. Deendothelialized areas showed various degrees of intimal thickening, which was mainly composed of smooth muscle cells in rabbits from groups 1 and 2. The intimal thickness of group 3 was significantly larger than that of other groups in any area examined. The intimal thickness of group 4 was less than that of group 3 despite the hypercholesterolemic state in the former group. The intima of borderline areas was generally thicker than that of nonendothelialized areas. Although the borderline lesions of groups 3 and 4 contained numerous macrophages, the number of macrophages was lower in the nonendothelialized compared with the reendothelized lesion. These data indicate that endothelial cell injuries can cause intimal thickening. The regenerated endothelial covering is favorable for monocyte migration and attachment. This process, together with the proliferation of smooth muscle cells, greatly contributes to the progression of atherosclerosis, which appears to involve lipid oxidation. Probucol prevented intimal thickening to a certain degree in this experiment in the normocholesterolemic as well as the hypercholesterolemic state.

Animals↗
PubMed1992

Effect of doxycycline on the generation of reactive oxygen species: a possible mechanism of action of acne therapy with doxycycline.

On the basis of a recent report that minocycline is effective in the treatment of acne inflammation by acting directly as an antioxidant on infiltrating neutrophils, we investigated whether doxycycline might also be capable of reducing the generation of reactive oxygen species, using human neutrophils and a cell-free, xanthine-xanthine oxidase system. The species investigated are superoxide radical anion (O2-), hydrogen peroxide (H2O2) and hydroxyl radical (OH.). Doxycycline significantly reduced the levels of O2-, H2O2 and OH. generated by both systems. Our results seem to suggest that the clinical effectiveness of doxycycline in the treatment of acne inflammation is due partly to its antioxidant effect on neutrophils.

Doxycycline↗
PubMed1992

[Aortic arch and descending aortic replacement under deep hypothermia and circulatory arrest through left thoracotomy--case report].

Graft replacement of the transverse aortic arch and the descending thoracic aorta was done for two cases with Stanford type B aortic dissection involving the aortic arch. Cardiopulmonary bypass was established with left atrium and femoral vein for venous line and femoral artery for arterial line. Patients were cooled until their EEG activity had disappeared, then the bypass was discontinued. Lesser curvature of the transverse aortic arch was resected and graft was sutured by beveled fashion. After reinstitution of the bypass, intercostal arteries (Th8-10) were reattached to the graft and distal anastomosis was made above the diaphragma. Postoperative recovery was uneventful in both cases.

Adult↗
PubMed1992

[An epidemiological study of methicillin-resistant Staphylococcus aureus (MRSA) isolated from medical staffs, inpatients and hospital environments at our hospital].

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important microorganisms which is causative of the nosocomial infections. Recently the incidence of isolation of MRSA is increasing from year to year in Japan. Especially MRSA isolated from inpatients are much higher than from outpatients. Therefore we have done epidemiological studies about MRSA isolated from medical staffs, inpatients and hospital environments in our hospital. Thereafter we examined phage typing and coagulase typing of those MRSA. MRSA were isolated more frequently from anterior nares of inpatients in compare with doctors and nurses. MRSA were isolated more frequently from the environments of MRSA carriers. Coagulase type II and phage type N.T. (not typable) were dominant type of MRSA in our hospital (69% and 61%). Our studies have revealed that the isolation frequency of MRSA is very high in our hospital. It seems to suggest that inpatients who are carrying MRSA are spreading MRSA out hospital environments and medical staffs.

Cross Infection↗
PubMed1992

[Arterial intimal thickening].

Disturbances in the integrity of the arterial endothelium are considered to be a primary event in the pathogenesis of atherosclerosis. Platelets do not adhere to the intact endothelium but with removal of the endothelium, a thrombotic response to the exposed thrombotic subendothelium occurs. With time, proliferation of smooth muscle cells occurs in the inner-most part of the media beneath the thrombus, and the proliferated smooth muscle cells migrate beyond the internal elastic lamina to invade the thrombus and organize it. A growth factor released from activated platelets (PDGF) stimulates smooth muscle cell proliferation. At the same time, the endothelium, adjacent to the thrombus, proliferates and covers the organizing thrombus from its margin. Thus, localized flat or raised intimal thickenings are formed from organization of mural thrombus or repair of intimal injury. There is much evidence that the release of platelet constituents can damage the vessel wall. Our study clearly demonstrated that material released from situ platelet-rich mural thrombi into the arterial circulation can cause endothelial damage and promote the proliferation of smooth muscle cells in the intima, downstream, and in remote segments of the arterial wall, without apparent endothelial denudation. PDGF, together with other growth factors, is also considered to be involved in smooth muscle cell proliferation in this case.

Arteries↗
PubMed1991

Molecular analysis of a Bjerkandera adusta lignin peroxidase gene.

A cDNA clone, lambda LPO-1, encoding a major lignin peroxidase from the basidiomycete Bjerkandera adusta was isolated and characterized. The nucleotide sequence of lambda LPO-1 predicts a mature protein consisting of 349 amino acids with a molecular weight of 37,225 preceded by a signal peptide of 23 amino acid residues. We have also cloned and sequenced the gene encoding lignin peroxidase from B. adusta. Comparison of these sequences reveals a lignin peroxidase gene structure consisting of 1,116 bp of protein-encoding DNA that is interrupted by four intervening sequences. The putative eukaryotic regulatory sequence, a TATA box, is present at position -75 relative to the translational initiation codon. Amino acid sequence homology between the coding regions of lambda LPO-1 and of the lignin peroxidase cDNA clone lambda ML-1 from Phanerochaete chrysosporium is 61%.

Amino Acid Sequence↗
PubMed1991

The distribution of IgG subclass autoantibodies in bullous pemphigoid analysed by immunofluorescence and immunoblotting.

The distribution of IgG subclasses in bullous pemphigoid (BP) autoantibodies in 14 BP sera and four biopsies was analysed by immunofluorescence (IF) and immunoblotting (IB). Three clones of monoclonal antibodies (MoAbs) to each IgG subclass were used. All 14 sera showed linear fluorescence in the basement membrane zone with IF, and 240 kDa and/or 180 kDa protein bands in human epidermal extract were detected by IB using a polyclonal antibody to total IgG. BP antibody in IgG4 subclass was found to be predominant, as it was detected most frequently and intensively in all positive sera and lesions studied by both techniques. In the IgG1 to IgG3 subclasses, a range of proportions of positive sera was obtained among MoAbs to the same IgG subclass in both techniques. However, one MoAb could detect IgG1 subclass BP antibody with a high frequency in both techniques. No difference in IgG subclass distribution of BP antibodies was observed during the course of the disease. In each serum, any IgG subclass of BP antibody recognized the identical BP antigen(s). These results suggest the predominance of IgG4 subclass and the possible presence of IgG1 subclass in BP antibodies.

Aged↗
PubMed1991

Effects of subminimal inhibitory concentrations of minocycline on neutrophil chemotactic factor production in comedonal bacteria, neutrophil phagocytosis and oxygen metabolism.

Comedonal bacteria, Propionibacterium acnes, P. granulosum and coagulase-negative staphylococci (CNS) seem to play an important initiating role in the inflammatory process by producing neutrophil chemotactic factors. The attracted neutrophils, after phagocytosis, release inflammatory factors such as reactive oxygen species (ROS). We investigated the effects of minocycline at subminimal inhibitory concentrations (sub-MIC), i.e. one-tenth MIC, on the production of human neutrophil chemotactic factors in comedonal bacteria, and on several inflammatory parameters of neutrophils, including neutrophil phagocytosis and generation of ROS (O2-, H2O2, OH.). ROS generation in a cell-free, xanthine-xanthine oxidase system was also assessed. Production of neutrophil chemotactic factors in all strains of P. acnes, P. granulosum and CNS were significantly suppressed by sub-MIC minocycline. Sub-MIC minocycline effectively reduced three kinds of neutrophil-generated ROS (O2-, H2O2, OH.). However, neutrophil phagocytosis and the ROS generated in a cell-free system were not markedly changed in the presence of sub-MIC minocycline. The results suggest that sub-MIC minocycline has an anti-inflammatory effect by inhibiting the production of neutrophil chemotactic factors in comedonal bacteria as well as ROS generated by neutrophils in the inflammatory process of acne.

Acne Vulgaris↗
PubMed1991

Inhibitory effect of azelaic acid on neutrophil functions: a possible cause for its efficacy in treating pathogenetically unrelated diseases.

It has been shown that acne, hyperpigmentation and lentigo malignant are more or less related pathogenetically to reactive oxygen species (ROS). It has recently been reported that azelaic acid is effective in treating these conditions and that it possesses anti-enzymatic and antimitochondrial activity, including cytochrome-P450 reductase and 5 alpha-reductase in microsomal preparations with nicotinamide adenine dinucleotide phosphate (NADPH). We therefore investigated the effects of azelaic acid on human neutrophil functions, such as chemotaxis, phagocytosis and ROS generation. ROS generation in a cell-free system was also assessed. The results revealed that neutrophil chemotaxis and phagocytosis as well as ROS generated in a xanthine-xanthine-oxidase system were not significantly changed in the presence of azelaic acid. However, azelaic acid markedly decreased O2- and OH. generated by neutrophils. It may be concluded that the reported clinical effectiveness of azelaic acid is partly due to its inhibitory action on neutrophil-generated ROS, leading to a reduction both in oxidative tissue injury at sites of inflammation and in melanin formation.

Chemotaxis↗
PubMed1991

Miliary tuberculosis presenting as fever and jaundice with hepatic failure.

A 58-year-old male patient with miliary tuberculosis presenting as jaundice and hepatic dysfunction was reported. He was admitted to the Miyazaki Medical College Hospital, Miyazaki, Japan, because of fever and jaundice. Chest x-ray revealed a calcified primary affect of tuberculosis in the left upper lung field and miliary shadows throughout both lung fields. Liver function tests showed indications of obstructive jaundice and hepatic dysfunction. He rapidly deteriorated and died 3 days after admission. Autopsy revealed disseminated miliary tuberculosis in all major organs. Many miliary tubercles were densely distributed in the liver, especially in and near the portal tracts. The intestine was free from tuberculous lesions. Miliary tuberculosis with jaundice is rare and its pathogenesis is discussed.

Fever↗
PubMed1991

Clinical and bacteriologic evaluation of OPC-7251 in patients with acne: a double-blind group comparison study versus cream base.

Twenty-eight patients with acne were assigned to 4 weeks of treatment with OPC-7251 (a new fluoroquinolone derivative) 1% cream or the cream base in a double-blind manner to evaluate the antibacterial effect of the drug on resident bacteria in the hair follicles and to evaluate clinical response. Propionibacterium acnes was isolated from 21 of the 28 acne patients. When the number of P. acnes was compared before and after treatment, the posttreatment P. acnes count in the OPC-7251 1% cream group was significantly (p = 0.000) reduced compared with that in the cream base group. OPC-7251 1% cream was also significantly (p = 0.019) superior to the cream base in terms of clinical response. P. acnes and Staphylococcus epidermidis isolated from the acne lesions were selected for their susceptibility to various antibacterial agents. The minimal inhibitory concentration of OPC-7251 against P. acnes and S. epidermidis was 0.10 to 0.20 and 0.024 to 0.10 micrograms/ml, respectively, which indicates that the drug has a potent antibacterial effect.

Acne Vulgaris↗
PubMed1991

Atypical multiple benign osteoblastomas accompanied by simple bone cysts. A case report.

A case of atypical benign osteoblastomas occurring at multiple sites in the maxilla and mandible of a 38-year-old woman, in association with simple bone cysts, is described. The tumors produced hazy or ground-glass-like semiradiolucent lesions with well-defined or poorly-defined margins on conventional radiographs. Histologically, the lesions were characterized by a proliferation of plump osteoblast-like cells forming trabeculae of osteoid and immature bone in a well-vascularized stroma. In addition, simple bone cysts associated with a radiolucent-radiopaque lesion consisting of lamellar bone and loose connective tissue were found next to one of the tumours. Possible pathogenesis of the tumours and cysts is discussed.

Adult↗
PubMed1991

Mechanism of anti-inflammatory action of glycyrrhizin: effect on neutrophil functions including reactive oxygen species generation.

The effect of glycyrrhizin on inflammatory mediators such as neutrophil functions including reactive oxygen species (ROS) generation was examined. Glycyrrhizin significantly decreased neutrophil-generated O2-, H2O2 and OH in a dose-dependent manner. However, the drug did not reduce any of the ROS generated in a cell-free, xanthine-xanthine oxidase system. The drug did not affect neutrophil chemotaxis or phagocytosis, either. The present study indicates that glycyrrhizin is not an ROS scavenger but exerts an anti-inflammatory action by inhibiting the generation of ROS by neutrophils, the most potent inflammatory mediator at the site of inflammation.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

Ultrastructure of budding process of Malassezia pachydermatis.

The ultrastructure of Malassezia pachydermatis and its budding process was investigated by scanning and transmission electron microscopy. The innermost layer of the cell wall showed the serrated structure characteristic of the genus Malassezia. In the daughter cell, this structure became more defined as the cell grew. The mode of conidium ontogeny was monopolar blastic development with a collarette. The appearance was similar to that reported previously for Malassezia furfur, with the following difference: the budding base was 0.9-1.1 microns in diameter which was broader than that of M. furfur (0.5-0.7 microns).

Cell Wall↗
PubMed1991

Effects of subminimal inhibitory concentrations of erythromycin, tetracycline, clindamycin, and minocycline on the neutrophil chemotactic factor production in Propionibacterium acnes biotypes 1-5.

Biotypes 1-5 Propionibacterium acnes (P. acnes) strains were grown in the presence of 1/10 minimal inhibitory concentrations (sub-MIC) of erythromycin (EM), tetracycline (TC), clindamycin (CLDM), or minocycline (MINO) and their culture filtrates were assayed for human neutrophil chemotactic activity using Boyden chamber methods. The addition of sub-MIC of MINO to the medium strongly suppressed the neutrophil chemotactic activity of the culture filtrates of P. acnes strains of all biotypes. In contrast, with sub-MIC of EM, TC, or CLDM, the activity of the culture filtrates of P. acnes strains of biotypes 2 and 3 were suppressed but those of biotypes 1, 2, and 5 were not. These results indicate that sub-MIC of MINO is capable of decreasing the inflammatory capacity of P. acnes strains of all biotypes.

Acne Vulgaris↗
PubMed1991

The ATPase-staining of Langerhans cells in previously stored skin tissues.

The ATPase-staining of Langerhans cells is usually done on fresh, unfixed biopsy specimens. In the present study, we attempted to stain these cells in previously stored tissues of guinea pig skin. The ATPase activity disappeared after freezing or preservation in formalin or ethanol. In contrast, tissue specimens which had been stored in physiological saline at 4 degrees C stained as well as fresh cells even after 14 days.

Adenosine Triphosphatases↗