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Biomedical subjects

H Ohkuni

Publications and source records attributed to H Ohkuni.

At least 37 records · Page 2Linked to original sources
PubMed1995

Alveolar fibrosis and capillary alteration in experimental pulmonary silicosis in rats.

To analyze the evolution of fibrotic and vascular changes in pulmonary silicosis, ultrastructural and immunohistochemical studies were made of the lungs of rats given a single intratracheal injection of silica particles. Early lesions were characterized by accumulations of macrophages and neutrophils in alveolar lumina and interstitium and by damage to alveolar capillaries and epithelial cells. The intraluminal masses of inflammatory cells developed into granulomas and became associated with myofibroblasts that migrated from the interstitium through the damaged epithelial lining. Type II epithelial cells and bronchiolar cuboidal cells proliferated rapidly to line the intraluminal granulomas, incorporating them into the interstitium. This process mediated the transition from intraalveolar fibrosis to interstitial fibrosis. Vascular damage was repaired by proliferation and migration of endothelial cells. Some endothelial cells in alveolar capillaries expressed Factor VIII-related antigen at 2 wk after silica infusion. In normal animals, this feature was present in peribronchiolar but not in alveolar capillaries. Two patterns of endothelial cell migration were shown by staining for proliferating-cell nuclear antigen. The first pattern was characterized by endothelial cells that extended their cytoplasm over preexisting, denuded basement membranes and replaced necrotic cells in alveolar capillaries. At 4 mo after injury, some of these cells had developed fenestrations. The second pattern consisted of budlike sproutings that developed only in peribronchiolar connective tissue. These observations indicate that peribronchiolar vessels are sources for renewal of alveolar capillary endothelium as well as for neovascularization.

Animals↗
PubMed1994

The presence of tumor necrosis factor-alpha and its antibody in the sera of cachexic patients with gastrointestinal cancer.

Although cancer cachexia has been shown to involve several cytokines, the tumor necrosis factor-alpha (TNF) has rarely been detected in such patients. In this study, sera from 21 patients with cancer cachexia were examined for the presence of TNF and the anti-TNF antibody using an enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively. All of the patients had recurrent cancer and manifested the characteristics of progressive body weight loss. TNF was found in the sera of four patients (20%) at levels ranging from 10.4 to 53.1 pg/ml, while a positive reaction for the anti-TNF antibody was detected in the sera from six patients (30%), two of whom showed both TNF and its antibody. Thus, either TNF or the anti-TNF antibody was present in the sera from 8 of 21 patients (40%). The results of this study indicate that TNF may be present in the circulation of at least 40% of cachexic patients, and suggest that it may be one of the main mediators of cancer-associated cachexia.

Adult↗
PubMed1994

[Synergism on the bactericidal effect of gentian violet (Gv) and acrinol (Ac) against Pseudomonas aeruginosa].

The MBCs of Ac against P. aeruginosa (7 strains) isolated from infected skin lesions of patients were more than 6400 micrograms/ml, and those of Gv were more than 1600 micrograms/ml. When either Ac or Gv was used independently, these dyes did not have the bactericidal effect of P. aeruginosa. When Gv was used in combination with Ac, predominantly synergism on the bactericidal effect of Ac and Gv against P. aeruginosa was observed. The MBCs of an Ac-Gv cocktail were between 100 micrograms/ml and 225 micrograms/ml. We have previously reported that Gv possessed significantly a bactericidal effect to MRSA isolated from clinical specimens. Therefore, these results suggested that a combination treatment by an Ac-Gv cocktail may be one of the useful drugs for the MRSA and P. aeruginosa mixed infection on the skin lesions which is frequently observed clinically.

Drug Synergism↗
PubMed1993

Biologically active extracellular products of oral viridans streptococci and the aetiology of Kawasaki disease.

A bacteriological study of isolates from the oral cavity of patients with Kawasaki disease (KD), age-matched non-KD patients and healthy children, showed that over half the KD and control isolates had gram-positive, catalase-negative cocci. About 50% of these organisms were identified as viridans streptococci by means of an API Strep 20 kit. Further identification by fluorometric DNA-DNA hybridisation demonstrated that the predominant species were S. oralis and S. mitis, each of which accounted for 25% of the isolates of viridans streptococci; 40% of viridans strains were unidentifiable; and S. sanguis and S. parasanguis were minor components. Studies in vivo showed that insertion of culture supernates of most of the viridans streptococci increased capillary permeability and induced redness with swelling and occasional bleeding in rabbit skin. One-third of S. mitis strains and one-fifth of the unidentified strains caused aggregation of human blood platelets, whereas S. oralis and other strains had no such effect. The distribution of extracellular lipoteichoic acids and glucan produced in the presence of sucrose was also examined. There were no significant differences in the recovery rate of viridans streptococci forming these biologically active extracellular products between KD and control groups.

Adult↗
PubMed1993

Cytokine induction by extracellular products of oral viridans group streptococci.

During an etiological study of Kawasaki disease (mucocutaneous lymph node syndrome [MCLS]), we found that dominant viridans streptococcal strains on tooth surfaces and in the throat of both MCLS patients and non-MCLS control children formed erythrogenic and biologically active, extracellular products. In this study, we demonstrated that erythrogenic culture supernatant concentrates of representative strains (two Streptococcus mitis and two Streptococcus oralis), when injected intravenously, induced serum tumor necrosis factor alpha, interleukin-6 (IL-6), and gamma interferon in muramyldipeptide- or Propionibacterium acnes-primed C3H/HeN mice. The concentrates also induced tumor necrosis factor alpha, IL-6, and thymocyte-activating factor (essentially IL-1) in murine peritoneal macrophage, human monocyte, and human whole-blood cultures. An erythrogenic, heat-labile extracellular protein fraction (F-1) that was concentrated from the culture supernatants of a representative S. mitis strain exhibited the above-mentioned cytokine-inducing activity. This partially purified F-1 fraction also induced thymocyte-activating factor and IL-6 in human umbilical vascular endothelial cell and gingival fibroblast cultures.

Animals↗
PubMed1993

[Effect of gentian violet on the elimination of methicillin-resistant Staphylococcus aureus (MRSA) existing in the decubitus region].

Methicillin-resistant Staphylococcus aureus (MRSA) is frequently isolated from skin lesions, such as in the decubitus region. There is a possibility that MRSA through these lesions can spread widely in a hospital. However, local treatment with most antibiotics and antiseptics (povidone-iodine) is not effective to eradicate MRSA from the infected decubitus. We have recently demonstrated that gentian violet (Gv) possessed a bactericidal effect against MRSA isolated from clinical specimens in vitro. This examination evaluated whether or not a topical ointment containing 0.1% Gv is effective to eradicate MRSA which existed in decubitus regions. Decubitus (14 clinical cases, ages 59-87 years) infected with MRSA were treated with 0.1% Gv-ointment once or twice daily after bathing in 0.1% Gv aqueous solution. Although all patients were treated with povidone-iodine and 9 out of 14 patients were given either local or systemic administration of antibiotics, those treatments were not effective to eradicate MRSA from decubituses. However, MRSA was not detectable in all cases within 34 days (average: 10.8 days +/- 2.7) after treatment with 0.1% Gv-ointment. The eradication of MRSA from decubitus areas tended to be delayed, depending upon the size and depth of decubituses (Grade III and IV) and complications such as diabetes mellitus. Skin irritability was not observed in any patients. These results suggest that 0.1% Gv-ointment is a useful material for the treatment of the MRSA-local wound infection. Treatment with Gv-ointment to MRSA-infected decubitus may exhibit a protective effect with regard to infection with MRSA in hospital.

Aged↗
PubMed1993

The adjuvant activity of pyrene in diesel exhaust on IgE antibody production in mice.

In this communication, it is shown that pyrene has an adjuvant activity on IgE antibody production when mice are immunized by an intraperitoneal injection of ovalbumin (OA) or Japanese cedar pollen allergen (JCPA) with pyrene. The effects of pyrene on IgE antibody production in mice were investigated to clarify the relation between pollen allergy and the adjuvanticity of the chemical compounds contained in diesel-exhaust particulates (DEP). In the first experiment, three groups of mice were immunized intraperitoneally six times at 2-week intervals with 1 microgram of OA alone, 1 microgram of OA plus 1 mg of pyrene, and 1 microgram of OA plus 1 mg of DEP, respectively. The IgE antibody responses to OA in mice immunized with OA plus pyrene or OA plus DEP were extremely enhanced as compared with those in mice immunized with OA alone, and the highest responses were observed in mice immunized with OA plus DEP. In the second experiment, mice were immunized with 10 micrograms of JCPA alone or 10 micrograms of JCPA plus 5 mg of pyrene in the same way. The IgE antibody responses to JCPA in mice immunized with JCPA plus pyrene were higher than those in mice immunized with JCPA alone. The intraperitoneal macrophages of the mice also clearly stimulated in vitro by pyrene on chemiluminescence assay. These results suggest that pyrene contained in DEP acts as an adjuvant in IgE antibody production when mice are immunized with antigens.

Adjuvants, Immunologic↗
PubMed1993

[Adhesion ultrastructures of mononuclear cells in experimentally-induced silicotic granuloma].

Experimental silicosis was induced by intratracheal infusions of 1 ml saline containing 50 mg standard silica (less than 5 microns diameter) in Sprague-Dawley rats. The lung tissues were observed histologically and ultrastructurally from half an hour up to 4 months. Macrophages, neutrophils, desquamated cells and their debris piled up around the alveolar ducts where the central cores of silicotic granuloma appeared. The granuloma became apparent by day 4 after the infusion and were covered by type II alveolar epithelial cells and bronchiolar cuboidal epithelial cells. Macrophages, fibroblasts and epithelial cells began to react to the antibody against proliferating cell nuclear antigen (PCNA) indicating self-replication on day 1. Macrophages in the granuloma made a close interdigitation with adjacent macrophages, and they gradually formed subplasmalemmal linear densities (SPLD) as paired forms between adjacent plasma membranes, and unpaired forms facing the interstitial matrix. SPLD were composed of linear densities with actin-like microfilaments along the leaflets of plasma membrane and were associated with extracellular dense bands which resembled a limited length of basement membrane. Interdigitation and SPLD structures were quite rare on day 1, but the number of macrophages with both structures increasingly appeared. The frequency of SPLD in macrophages also increased on a time course of granuloma maturation up to 4 months. Thus SPLD, which were originally found in the mononuclear phagocytes including macrophages, epithelioid cells and multi-nucleated giant cells, particularly in immune granuloma of man, also played a basic role in immobilizing macrophages in lesions of silica-induced granulomas.

Animals↗
PubMed1992

Immunochemical studies and complete amino acid sequence of the streptokinase from Streptococcus pyogenes (group A) M type 12 strain A374.

The complete amino acid sequence of the streptokinase (SKase) of Streptococcus pyogenes M type 12 strain A374, isolated from a patient with poststreptococcal glomerulonephritis (PSGN), was determined. The epitope domain for the monoclonal antibody N-59, which cross-reacts with SKases of both the PSGN-associated strain and S. equisimilis H46A (a non-PSGN-associated strain), was predicted to be localized in residues 370 to 374. The epitope domain specific for monoclonal antibody RU-1, which reacts only with the PSGN-associated SKase, was localized to residues 164 to 236.

Amino Acid Sequence↗
PubMed1992

Detection of antibodies against streptococcal peptidoglycan and the peptide subunit (synthetic tetra-D-alanyl-bovine serum albumin complex) in rheumatic-diseases.

Serum antibodies reactive with streptococcal cell wall peptidoglycan (PG) and its peptide subunit (synthetic tetra-D-alanine) were measured by enzyme-linked immunosorbent assay (ELISA) in patients with rheumatoid arthritis (RA), juvenile rheumatoid arthritis (JRA), osteoarthritis and acute rheumatic fever (RF) compared with healthy subjects. Using 'checkerboard' titrations, anti-PG antibody in human serum was detected at a concentration of PG antigen at 10 micrograms per well with serum dilutions of 1:1,000. For measurement of anti-tetra-D-alanine antibody, the antigen, (D-Ala4)31 was used at 0.5 micrograms per well and sera were diluted to 1:200. When the IgG antibody levels to the PG and the tetra-D-alanine of the sera of patients with RA, JRA and RF were compared with sera from healthy subjects, the sera of the patients had significantly higher levels than did healthy subjects. Antibody that reacted with the PG in serum was absorbed with purified group-specific C-carbohydrate (A-CHO), but A-CHO was not capable of absorbing anti-(D-Ala4)31 antibodies. Therefore, the peptide subunit should be used as antigen in order to measure the specific antibody to PG. Both anti-PG and anti-tetra-D-alanine antibody in human sera primarily belonged to the IgG2 subclass.

Adolescent↗
PubMed1991

Detection of nephritis strain-associated streptokinase by monoclonal antibodies.

Monoclonal antibodies (MAbs) N-59 and RU-1 were produced by immunisation of mice with streptokinase secreted by Streptococcus group A, type 12, strain A374 isolated from a patient with post-streptococcal glomerulonephritis (PSGN) and were characterised by Western blot analysis. MAb N-59 recognised antigenic determinants shared by both nephritis strain-associated streptokinase (NSA-SKase) and streptokinase of Streptococcus group C (C-SKase); MAb RU-1 reacted only with NSA-SKase. All nephritis-associated group A streptococcal strains tested reacted with MAb N-59; 87.5% of these strains reacted with MAb RU-1. MAb N-59 reacted with SKase produced by group G streptococcal strains isolated from patients with PSGN, and MAb RU-1 recognised SKase in two out of three of these strains.

Animals↗
PubMed1991

Relationship between bacterial meningitis and acellular pertussis vaccine.

We studied case reports of bacterial meningitis and estimated its incidence per 100,000 in three areas of Osaka Prefecture which differed in population and vaccination schedule for the years of 1987 and 1988. To estimate incidence, we used a simple mathematical method derived from surveillance data for a reported number of exanthem subitum to obtain a coverage constant. With this coverage constant, we estimated the incidence of bacterial meningitis per 100,000 population for each area. In the Toyono area, with a population of about one million, the acellular pertussis vaccine series is started in children of three to six months of age and the incidence of bacterial meningitis per 100,000 was 1.95 in 1987 and 5.35 in 1988. Conversely, in Osaka City and Sakai City, with populations of about 2.6 and 0.8 million, respectively, the vaccine is given to children over two years of age and the incidence of bacterial meningitis per 100,000 was estimated to be 6.25 and 3.23 in 1987 and 14.62 and 1.07 in 1988, respectively. Thirteen cases of bacterial meningitis had been reported by Minoh City Hospital, in the Toyono area, and the Osaka City Infectious Disease Center in 1987 and 1988. Patients were seven males and six females and aged from less than a month to four years old. In six, the causal agent was Haemophilus influenzae type B, in three, Group B streptococcus, in two, Neisseria meningitidis and in one, Listeria monocytogenes. Only one of the thirteen patients had received an acellular pertussis vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1991

Calculation of efficacy of acellular pertussis vaccine from the number of pertussis patients and vaccinees in three areas.

A study is presented of the efficacy of acellular pertussis vaccine based on the number of pertussis patients and its relationship to vaccination rate in three demographic areas of Osaka Prefecture, Japan. In three separate areas within Osaka Prefecture, the pertussis vaccine is given to children three to six months of age, and in the other two it is given to children two years of age or older. Use of a mathematical method to correct the reported number of pertussis patients per 100,000 population with a constant obtained from analysis of the reported number of exanthem subitum cases allowed us to compare the number of pertussis patients in the three areas with each other. Vaccination rate by age and incidence of pertussis in each city revealed the efficacy of acellular pertussis vaccine to be 94.8%.

Age Factors↗
PubMed1988

Enzyme-linked immunosorbent assay of antibody to group A Streptococcus-specific C carbohydrate with trypsin-pronase-treated whole cells as antigen.

We describe the measurement by enzyme-linked immunosorbent assay of antibody to group A Streptococcus C carbohydrate in immunized rabbits and human sera, with trypsin-pronase-treated group A streptococcal whole cells used as the antigen. The optimal concentration of the enzyme-treated whole cells used to coat the wells was 2 x 10(7) cells per well. Rabbit antiserum diluted to 1:12,800 and human serum diluted to 1:1,000 were found to be the optimal concentrations for antibody measurement. Antibody that reacted with enzyme-treated whole cells in rabbit antiserum was absorbed with group A streptococcal whole cells, purified C carbohydrate, and N-acetylglucosamine only. Enzyme-treated whole cells did not react with anti-lipoteichoic acid antibody, and rabbit antiserum did not react with lipoteichoic acid. There was a highly significant correlation between the anti-C carbohydrate antibody titrated with enzyme-treated whole cells and that with purified C carbohydrate as antigen. The correlation coefficient for the immunoglobulin M (IgM) antibodies was r = 0.75, and for the IgG antibodies it was r = 0.77. When the IgG antibody titers to the enzyme-treated whole cells of the sera of patients with acute poststreptococcal glomerulonephritis and rheumatic fever were compared with those of sera of healthy individuals, the sera of patients with poststreptococcal sequelae had significantly higher titers than did healthy individuals. Although anti-C carbohydrate antibody in human sera mostly belonged to the IgG2 subclass, there was anti-C carbohydrate antibody that belonged to the IgG3 subclass in a certain percentage of patients with rheumatic fever and acute poststreptococcal glomerulonephritis.

Adolescent↗
PubMed1988

Streptococcal antibody: as an indicator of tonsillectomy.

The significance of antibody for streptolysin-O concerning tonsillectomy was studied. The results obtained were as follows. 1. The upper limit of ASO titer in 5,121 school children was 250 u and a value of more than 333 u was considered abnormal. But the level of the normal limit was different from year to year. 2. Among 143 cases with a high ASO titer of more than 833 u, only 12 cases had recurrent tonsillitis. There was no correlation between the tonsillar hypertrophy and the height of streptococcal antibodies. 3. There was a correlation between the titers determined by ELISA IgG-ASO and ASO in Todd units (r = 0.69), but there was no agreement between the titers determined by ELISA IgM-ASO and ASO in Todd units. 4. IgM-ASO determined by ELISA showed high levels in cases with early stages of streptococcal infection, focal infection and streptococcal carriers. Cases with high ASO, both IgG- and IgM-subclasses, were considered to have an indicative factor for tonsillectomy.

Acute Disease↗