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R Azuma

Publications and source records attributed to R Azuma.

At least 37 records · Page 2Linked to original sources
PubMed1992

Experimental Tonsillophilus suis granuloma in rats and guinea pigs.

Rats and guinea pigs were experimentally infected by intradermal and intraperitoneal inoculation of T. suis. These animals were observed for pathologic changes at various stages. Macroscopic observation disclosed visible grayish white soft nodules at the injection site in those inoculated intradermally and many grayish white nodules in the peritoneum of those inoculated intraperitoneally. Histopathological examination revealed the presence of characteristic microbial elements in the centre of the lesions. Various stages of the lesions were recognized; the early stage being abscess, the advanced stage being pus-forming granuloma and the final stage being residual granuloma. The microbial elements were composed of spores, thalli and multilocular tubers. Clubs were formed around microbial elements in rats inoculated intradermally and in guinea pigs inoculated intraperitoneally. The characteristic T. suis lesions in pigs were reproduced by experimental infection of this organisms in rats and guinea pigs, and thus the pathogenicity of T. suis was confirmed.

Abscess↗
PubMed1991

Pathology of infection caused by Dermatophilus-like organisms in porcine tonsils.

The authors investigated the occurrence of Dermatophilus-like organisms in sulphur granules of porcine tonsils. Light and electron microscopic studies, together with histochemical examination, were carried out to elucidate the mode of growth of the organism in the tonsils, the interaction between the organisms and host cells, and the nature of the radiating clubs around the organisms. Sulphur granules were found in about 15 and 70 per cent of market pigs and breeding pigs, respectively. Of the pigs having tonsillar granules, Dermatophilus-like organisms were observed in about 70 per cent of market pigs, and in nearly all breeding pigs. The organisms invaded tonsillar crypts to produce lesions resembling actinomycotic abscesses up to 5 mm in diameter. Dermatophilus-like organisms were demonstrated in various morphological forms ranging from filamentous to tuber-shaped or coccoid bodies. In the lesion, the bacterial cells adjacent to the host cell reaction showed distinct degenerative changes forming thick amorphous masses on the surface of the bacterial cells. The amorphous masses seemed to be derived from the bacterial cells but showed histochemical components different from those of the bacterial cells. These masses had numerous protrusions forming clubs. Phagocytic neutrophils close to the amorphous masses were presumed to play a role in deposition of the club material. Macrophages also appeared to participate in the inflammation leading to a granulomatous lesion. These findings suggested that the clubs might be formed by an interaction between the organisms and host cell reaction.

Abscess↗
PubMed1989

Effects of hEGF (MG111) on gastric mucosal potential difference in rats.

hEGF (GMG111) given i. v. significantly and dose-dependently suppressed the reduction in gastric mucosal potential-difference (PD) induced by 30% ethanol in rats. Pretreatment with indomethacin did not affect its effect, thereby suggesting that endogenous prostaglandins will not be involved in the mechanism of action of MG111. These results indicate that MG111 protects the weakening of "gastric mucosal barrier". The PD was significantly reduced when MG111 was given i. v. at 20 micrograms/kg. This reduction caused by MG111 was not affected by pretreatment with atropine, hexamethonium, propranolol, and phentolamine.

Animals↗
PubMed1988

High-performance liquid chromatographic determination of 6-amidino-2-naphthyl [4-(4,5-dihydro-1H-imidazol-2-yl) amino]benzoate dimethanesulphonate and its metabolites in biological fluids.

6-Amidino-2-naphthyl [4-(4,5-dihydro-1H-imidazol-2-yl) amino]benzoate dimethanesulphonate has been developed for the therapy of pancreatitis. A reversed-phase high-performance liquid chromatographic assay of the levels of this drug and its metabolites in biological fluids was investigated. Fluorescence detection with post-column alkaline degradation was used for the determination of the intact drug and the amidinonaphthol moiety metabolite, and ultraviolet detection at 254 nm was used to determine the levels of the benzoic acid moiety metabolite. Satisfactory recoveries and variabilities of the intact drug and its metabolites from biological fluids were obtained. The detection limits for the intact drug and amidinonaphthol were 0.5 ng/ml at a signal-to-noise ratio of 12 in plasma and 10 ng/ml at a signal-to-noise ratio of 32 in urine and homogenized faeces, and those of benzoic acid were 5 ng/ml at a signal-to-noise ratio of 3 in plasma and 50 ng/ml at a signal-to-noise ratio of 7 in urine and homogenized faeces.

4-Aminobenzoic Acid↗
PubMed1985

Experimental subcutaneous granulomas in sheep with Dermatophilus-like microorganisms from porcine tonsil.

The pathogenicity of the Dermatophilus-like microorganisms from porcine tonsil and the light and electron microscopic findings were studied with adult ewes. The early lesions were abscessess and advanced ones were granulomas after the subcutaneous inoculation. The granulomas were composed of the central bacterial colonies and the layers of the neutrophils, epithelioid cells and giant cells, and peripheral connective tissues. Epithelioid cells and giant cells were identified by the large euchromatic nuclei, abundant organelles and interdigitation of the blunt pseudopods in the ultrastructure. The lesions were very similar to subcutaneous granulomas in sheep and cattle due to Dermatophilus congolensis (atypical dermatophilosis), actinomycosis and nocardiosis.

Actinomycetales Infections↗
PubMed1984

Granulomatous sub-dermal lesions in sheep inoculated with Dermatophilus congolensis.

Dermatophilus congolensis was inoculated subcutaneously into 6 ewes and the resulting lesions were examined by light and electron microscopy. The organism was recovered from the subcutaneous lesions. The lesions were suppurative in the early stages and granulomatous in the advanced stage, but abscesses were the usual lesion observed. The granulomas were composed of several layers; central bacterial colony, neutrophil layer, layer of macrophages, epithelioid cells and Langhans and foreign body type giant cells with a periphery of connective tissue. Multiloculated granulomas were observed. Electron microscopic examination confirmed the cell types of the lesions. Epithelioid and giant cells were characterized by the shape and number of the nuclei and complex and abundant organelles. Interdigitations of the blunt pseudopodia of adjacent cells were also found. It is concluded that the organism can produce both granulomatous lesions and abscesses which differ from those of orthodox dermatophilosis but are similar to those described in "atypical dermatophilosis".

Actinomycetales Infections↗
PubMed1983

Morphology of experimental actinomycotic abscess in mice with Dermatophilus-like microorganisms from porcine tonsil.

Experimental infection in mice with Dermatophilus (D.) congolensis-like microorganisms was carried out, intraperitoneally and subcutaneously. This strain had been isolated from porcine tonsil and reported to be different in some morphological and biological points from D. congolensis. Macroscopic examination revealed multiple abscesses in the peritoneal cavities, or subcutaneous abscesses after the intraperitoneal or subcutaneous injection respectively. Histopathologic examination revealed the characteristic arrangement of the neutrophils surrounding the bacterial colony and peripheral macrophages in the abscess lesions. The lesions contained many microorganisms which showed wide range of the characteristic morphologic variation such as: mycelial elements, coccoid elements and large coccoid elements with transverse or longitudinal septa. Chlamydospore-like elements were sometimes found in the microcolonies in early lesions. The morphology of the lesions and the microorganisms was compared with those of other bacteria including D. congolensis.

Abscess↗
PubMed1983

A study on heifer mastitis in Japan and its causative microorganisms.

Survey and bacteriological examination were conducted on heifer mastitis in Hokkaido, the northern island of Japan over a period from 1976 to 1981. The disease occurred in heifers, mostly 13 to 18 months old, less than a half of which was pregnant in late summer or in August and September. Infection occurred predominantly in a front quarter than a rear one. Some microorganisms were isolated by the CO2 gas jet method from all the 74 secretions from the affected quarters of 67 heifers. Actinomyces pyogenes ( Corynebacterium pyogenes) was isolated from 49 secretions (66.2%), forty-six of which were involved in mixed infection with other microorganisms, including Peptococcus indolicus that was found in 41 secretions. Streptococcus dysgalactiae was isolated from 13 secretions, from nine of which were obtained pure cultures. The microorganisms harbored in secretion were much more closely associated simultaneously with A. pyogenes and P. indolicus than with A. pyogenes alone or a combination of A. pyogenes and any other microorganism than P. indolicus . This is the first report that P. indolicus was isolated from heifer mastitis in Japan. The "score" used for the expression of quality of milk secretion seemed to be useful for the clinical diagnosis of heifer mastitis. The disease in Hokkaido may be etiologically identical with summer mastitis found in the northern European countries.

Actinomyces↗
PubMed1983

Streptococcus R (Streptococcus suis type II) infection in pigs in Japan.

Since the first outbreak of an epizootic disease on a pig farm in Shimane Prefecture in 1979, similar diseases have occurred continually on other 8 pig farms in the same prefecture until 1982. Main clinical symptoms of the disease were recumbency, convulsion, anorexia and paddling. The diseased pigs ranged mostly from 35 to 67 days of age. Monthly fatality on one pig farm for 1 year was 0.2 to 3.6%. Morbidities in affected litters were mostly at a level of 20 to 30% on 7 pig farms. The diseases were diagnosed as streptococcal meningitis and septicemia with each one of endocarditis and pneumonitis by pathological and bacteriological studies on 20 affected pigs. Distribution of piglets from a breeding farm to pig farms was considered as one of the causes of prevalence in the prefecture. Representative 20 strains of the isolates from diseased animals on 9 pig farms were identified as Streptococcus R (Streptococcus suis type II) by biological and serological examinations. For the latter examination, anti-Streptococcus R, S and T sera were prepared. It was also indicated that the disease had occurred in 8 prefectures in addition to Shimane, because positive results had been obtained from 41 strains submitted from those prefectures for serological diagnosis. The minimal inhibitory concentration was examined in 18 drugs to 19 isolates. It was the lowest in ampicillin and thiopeptin of all the drugs.

Animals↗
PubMed1982

Outbreaks of type C botulism in waterfowl in Japan.

Four outbreaks of botulism in waterfowl were encountered over a five-year period of 1973 to 1977 in Japan. In all the outbreaks toxin was detected from all 12 sera, twenty-three of 24 gizzard contents from diseased or dead birds and one of three maggots. It was neutralized with Clostridium botulinum type C antitoxin serum, regardless of its origin. By using CO2 gas jet method, C. botulinum was isolated from four of 11 gizzards from diseased birds, five of 7 ones from dead birds, one of one maggot and one of one sludge sample, that is, eleven of 20 specimens in total. All 20 strains were identical with C. botulinum type C in biological properties. Most of the isolates showed a toxin titer ranging from 1,000 to 200,000 LD50 for mice. Four of them were identified as type C by mouse neutralization tests with antitoxin sera. The toxic suspensions of a strain 1-15 were administered orally to Chinese spot-billed ducks, which died when more than 200,000 LD50 mouse toxin was administered. Environmental conditions for occurrences of waterfowl botulism were discussed.

Animals↗