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Biomedical subjects

H L Ko

Publications and source records attributed to H L Ko.

At least 109 records · Page 6Linked to original sources
PubMed1980

The correlation of susceptibility of different Propionibacterium strains to macrophage killing and antitumor activity.

The stimulation of the reticuloendothelial system and antitumor activity against sarcoma-L-1 of three different strains of Propionibacterium was investigated. The bacteria injected intraperitoneally with a single dose of 1 mg per mouse appeared to possess different effectiveness in both assays used. The same strains were examined for their susceptibility to phagocytosis and intracellular killing by murine peritoneal macrophages. The results obtained showed correlations between Propionibacterium resistance to degradation by phagocytic cells and their antitumor and stimulatory activities. It is concluded that the potency of antitumor and stimulatory activities of different strains of Propionibacterium are closely related to their cell wall structure.

Animals↗
PubMed1980

Action of three species of Propionibacteria (P. granulosum, P. acnes, P. avidum) on experimental tumor systems in mice.

The antitumor activity of three different species of Propionibacteria (P. granulosum, P. avidum and P. acnes) against murine Sarcoma 180 and Moloney-Sarcoma-Virus-induced tumor (MSV tumor) was investigated. All three Propionibacteria injected intraperitoneally or intratumorally in multiple doses of 1 mg per mouse appeared to be effective regarding the retardation of growth and the stimulation of regression of Sarcoma 180 in CFW mice. Moreover, the application of Propionibacteria significantly prolonged the survival of Sarcoma-180-bearing mice. No significant differences were found in antitumor effect against Sarcoma 180 between P. granulosum, P. Avidum and P. acnes, but in general, intratumoral injections of all three strains were more effective than intraperitoneal applications. All three strains of Propionibacteria were equally ineffective regarding the retardation of growth and the stimulation of regression of MSV tumors in adult NMRI mice, as assessed after intraperitoneal injections of P. granulosum, P. avidum or P. acnes (1 mg per mouse) 3 days prior to inoculation of virus particles.

Animals↗
PubMed1980

INfluence of Pseudomonas aeruginosa proteases on prothrombin, plasminogen and fibrinogen.

Out of 136 strains of Pseudomonas aeruginosa tested, 101 produced a procoagulant protease and 70 a protease with fibrinolytic activity. Strain No. 1800 producing both these proteases served as a source of the crude enzyme mixture. The crude enzyme was isolated from the supernatant and subjected to fractionation by isoelectric focusing. Five active components were isolated. Activities of individual proteases were compared. It was found that for prothrombin activation a protease characterized by isoelectric point of 7.0 is responsible; this protease is different from both collagenase and elastase. Protease available at isoelectric point of 8.8 is plasminlike and is also not identical with collagenase and elastase.

Blood Coagulation↗
PubMed1980

Effect of three strains of propionibacteria (P. granulosum, P. avidum, P. acnes) and cell-wall preparations on lymphocytes and macrophages.

The effect of the strains of Propionibacteria (P. granulosum, P. avidum, P. acnes) on functional and metabolic activities of mouse lymphocytes and rabbit macrophages was examined in vivo and in vitro. In some of the experiments bacterial cell walls isolated from the above bacteria were tested and compared with the activity of whole bacteria. In isolated lymph-node lymphocytes influx of 86Rb and its inhibition by ouabaine, release of 86Rb and 51Cr from prelabelled cells, as well as spontaneous and PHA-stimulated incorporation of 3H-uridine were tested after treatment with 10 or 50 microgram/ml of Propionibacteria (whole cells or cell walls). Phagocytosis of 32P-labelled Staphylococci and reduction of Nitro-BT were examined in isolated rabbit peritoneal macrophages treated with the above concentrations of Propionibacteria. Clearance of 32P-labelled Staphylococci from peripheral blood in rabbits treated with 5 mg per kg body weight of Propionibacteria was also studied. All three strains of Propionibacteriae stimulated 86Rb influx into lymphocytes, the effect being observed only in concentrations leading to parallel increase of 86Rb and 51Cr release from prelabelled cells. No significant differences in activity between the three tested strains of bacteriae were found. Propionibacteria of a dosage of 50 microgram/ml significantly increased spontaneous and PHA-stimulated incorporation of 3H-uridine into lymphocytes. All three strains of Propionibacteria markedly stimulated both phagocytosis and intracellular digestion (as measured by the ability to reduce Nitro-BT) in isolated peritoneal macrophages. This was accompanied by faster clearance of Staphylococci from peripheral blood of rabbits treated with 5 mg per kg body weight of Propionibacteriae. The obtained results showed direct stimulation of lymphocytic and macrophagic functional activity by whole cells and isolated cell walls of all three tested strains of Propionibacteria.

Animals↗
PubMed1980

Recovery of hemopoiesis in lethally irradiated mice after treatment with propionibacteria.

Three investigated strains of propionibacteria (P. acnes, P. granulosum and P. avidum) injected intraperitoneally in doses of 1.5 mg per mouse, significantly prolonged survival of lethally (8.50 R) irradiated mice. P. granulosum, being the most effective in increasing survival of irradiated mice was chosen for the studies on the activity of bone-marrow pluripotent stem cells. The number of endogenous spleen colonies was significantly increased in mice injected with P. granulosum 3 days prior to or 4 hours after irradiation with 650 R. However, injection of P. granulosum to donors prior to bone-marrow transplantation significantly decreased the number of exogenous spleen colonies in recipients irradiated with 850 R. These results, together with the observed increase in number of CFU-S in peripheral blood and elevated relative spleen weight after injection of P. granulosum, suggest that propionibacteria stimulate migration of CFU-S from bone-marrow via peripheral blood into spleen. Stimulation of CFU-S proliferation and differentiation is also taken into account.

Animals↗
PubMed1979

[Differentiation of various Propionibacterium species from acne-vulgaris efflorescences].

Samples of pustules taken from 37 patients with acne (a. vulgaris, a. papulopustulosa, a. conglobata) were examined using different culture mediums for the growth of anaerobic to microaerophilic coryneforms. We identified 46 isolates of Propionibacteria which were tested according to their morphological, biochemical, serological, and phagelysotopic reactions. Three types of Propionibacteria were found: P. acnes (33), P. granulosum (11) and P. avidum (2). Nine samples showed P. acnes combined with P. avidum, four samples from patients with acne conglobata showed P. granulosum or P. avidum only. Tests from 37 patients are too limited to reach definite conclusions. We are not able to suggest any correlation between type and degree of clinical acne, and the isolated Propionibacteria. These data indicate that pustules from patients with acne of all clinical degrees can contain P. acnes as well as other anaerobic coryneforms. Therefore, other species of anaerobic bacteria, particularly those of the "propionibacteria type", should be included in any discussion about the aetiological factors of acne.

Acne Vulgaris↗
PubMed1978

Differential susceptibility of Propionibacterium acnes, P. granulosum and P. avidum to free fatty acids.

The susceptibility of 98 Propionibacterium acnes, P. granulosum and P. avidum strains isolated from acne cases and appropriate reference strains to decanoic, dodecanoic, octadeca-9,12 dienoic, and octadeca-9,12,15 trienoic acids was investigated using minimal inhibitory concentration estimation by an agar dilution techique. The tested acids showed their relative antibacterial activity in the following order: C18:3 delta 9,12,15 greater than C18:2 delta 9,12 greater than C12:0 greater than C10:0 Differences between minimal inhibitory concentration values for P. acnes, and P. avidum versus P. granulosum strains were demonstrated in the cases of octadeca-9,12 dienoic, and octadeca-9,12,15 trienoic acids.

Decanoic Acids↗
PubMed1978

Propionicins, bacteriocins produced by Propionibacterium avidum.

One hundred strains of Propionibacterium acnes, granulosum and avidum were tested for susceptibility toward bacteriocins produced extracellularly by eight strains of Propionibacterium avidum. Some bacteriocin-producing strains were inhibitory for all strains tested. A name propionicins, is proposed for bacteriocins produced by P. avidum.

Antibiosis↗
PubMed1977

Clotting and fibrinolytic activities of Bacteroides melaninogenicus.

106 strains of Bacteroides melaninogenicus ss. asaccharolyticus, intermedius and melaninogenicus were tested for production of extracellular blood clotting and fibrinolytic factors. 78.3% of tested strains caused clotting of rabbit plasma and 79.2% activated human plasminogen. Strains producing the clotting or fibrinolytic factor only were isolated. Both factors were quite active, as positive results for most strains were detected within one hour of incubation in controlled test system.

Animals↗
PubMed1976

Antimicrobiol susceptibility of Propinibacterium acnes and related microbial species.

The minimal inhibitory concentrations of 32 antimicrobial agents were established for 73 strains of Propionibacterium acnes and four related species (P. granulosum, P. avidum, Corynebacterium minutissimum, and C. parvum). Most strains showed good susceptibility to those agents usually considered active against gram-positive organisms. With the exception of C. minutissimum, the strains tested revealed more or less identical susceptibility ranges. The lowest minimal inhibitory concentrations were observed with benzylpenicillin, ampicillin, cephalothin, rifampin, erythromycin, clindamycin, and minocycline. C. minutissimum was more susceptible to gentamicin, sisomicin, tobramycin, and fusidic acid but more resistant to most other drugs than were the other species examined.

Anti-Bacterial Agents↗
PubMed1975

Studies on bacteriophages of Propionibacterium acnes.

With the help of adaptation experiments, 61 phage preparations out of 36 Propionibacterium acnes bacteriophages (32 isolated by us and 4 sent from abroad) were established. On the basis of their stability, spectrum of activity, and virulence, 13 phages were selected for phagetyping. 58 well-classified P. acnes strains were grouped into 7 phage-types. 7 strains of P. granulosum, two strains of P. avidum, and one yet ungroupable microserophilic propionibacterium strain were resistant to all 61 phages, even when tested in 100 X RTD. A combination of phagetyping with biotyping resulted in data especially useful for the differentiation of P. acnes.

Bacteriophage Typing↗
PubMed1973

Fermentative and serological studies on Propionibacterium acnes.

Seventy-two Propionibacterium acnes strains, among which were five from the American Type Culture Collection, five from the Center for Disease Control, and four of group II of Voss, were thoroughly examined both biochemically and serologically. On the basis of the fermentation of inositol, maltose, mannitol, and sorbitol, eight biotypes were distinguished. By means of tube agglutination tests with the five absorbed antisera, 95, C51, D34, S140, and Beck, 11 serotypes were defined. The biotypes and serotypes showed no striking relationship to each other. Combined biotyping and serotyping is suggested for subdivision of the P. acnes species.

Absorption↗
PubMed1972

Serological studies on Actinobacillus actinomycetem-comitans.

One hundred strains of Actinobacillus actinomycetem-comitans were examined serologically by determining their agglutination reactions with six absorbed antisera. Twenty-four reaction patterns were found, and the results were reproducible. The agglutinating antigens were heat-stable. Precipitation reactions were also studied by means of the Ouchterlony agar-gel diffusion technique with Fuller and acetone extracts. The agglutination test was considered preferable for epidemiological and ecological investigations on A. actinomycetem-comitans.

Acetone↗
PubMed1970

Actinobacillus actinomycetem-comitans: fermentative capabilities of 140 strains.

Fermentative capabilities of 140 strains of Actinobacillus actinomycetem-comitans were studied. Findings correspond closely with those reported previously by Heinrich and Pulverer (12 strains), and by King and Tatum (33 strains). All strains ferment glucose, levulose, and maltose and reduce nitrate to nitrite. Reactions with glycogen and starch are exceedingly diverse. Eight different biotypes have been identified on the basis of their reactions with galactose, mannitol, and xylose.

Actinobacillus↗