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H Kirchhoff

Publications and source records attributed to H Kirchhoff.

At least 55 records · Page 3Linked to original sources
PubMed1989

The influence of social rank on the susceptibility of rats to Mycoplasma arthritidis.

Social ranks (A, O, rest) of adult male inbred rats housed in groups of four per cage were determined by repeated observations of their ejaculatory patterns under competitive conditions. Once ranked, they were intravenously infected. Fifteen clinical, hematological, and serological characters were continuously observed during 110 days. Body weight reduction, arthritis score, and specific IgG antibody titers were chosen as guideline characteristics and compared between different genotypes and social rank classes. Genotypic differences account for 60-80% of the individual differences and social rank differences account for 0-40% of the individual differences within isogenic animals. Social rank affects the individual genotypes in an opposite way. Rank A males are less susceptible in genotype DA but showed increased susceptibility in genotypes AS. In genotype LEW, influence of social rank on susceptibility to Mycoplasma arthritidis could not be verified. Specific IgG antibody titers are lower in ranks showing a higher degree of susceptibility.

Animals↗
PubMed1989

Investigation of seal mycoplasmas for their cytotoxic potential on tracheal organ cultures of SPF and gnotobiotic rats.

Eleven mycoplasma strains isolated from several organs of diseased seals during the seal epidemic in the Baltic and North Sea in 1988 and the seal epidemic along the New England coast in 1979-1980, were investigated for their cytotoxic potential by inoculation into tracheal organ cultures of SPF and gnotobiotic rats. The mycoplasma strains belonged to three different species. Administration of 2.0 x 10(2) to 4.5 x 10(7) colony forming units of all of the mycoplasma strains caused an inhibition of the ciliary activity and cytopathological changes within the epithelial cells appearing as bleb-like protuberances by observation with the inverted microscope. There was, however, a distinct difference in the strength of the cytopathological changes caused by the three mycoplasma species. Semi- and ultrathin sections of tracheal rings infected with the seal mycoplasma strain 852, observed by light and electron microscopy, revealed a heavy tissue injury of the tracheal epithelium and dumbbell-shaped mycoplasmas adhering to degenerated epithelial cells.

Animals↗
PubMed1989

pH-controlled continuous cultivation of mycoplasmas.

The continuous cultivation of mycoplasmas in a pH-controlled metabolistat was investigated with the fermentative strain Mycoplasma mobile 163K and the nonfermentative strain Mycoplasma arthritidis ISR1. The addition of medium and the removal of culture suspension were regulated by acid production from glucose by M. mobile 163K and by ammonium production from arginine by M. arthritidis ISR1, respectively. For both strains the optimal pH for continuous growth was 7.0. The steady state could be maintained for at least 21 days. With CFU of 8.4 X 10(9) ml-1 (M. mobile 163K) and 3.2 X 10(9) ml-1 (M. arthritidis ISR1), the cell concentrations were slightly higher than those obtained in batch cultures. The dependence on the adjusted pH values was measured for several parameters, such as flow rate, CFU, glucose fermentation or production of ammonia, and gliding velocity. Since the long lag phases of batch cultures can be avoided, pH-controlled continuous cultures provide an appropriate system for the production of mycoplasma cells.

Acetates↗
PubMed1988

Isolation of anaerobic mollicutes from the intestine of swine.

Anaerobic mollicutes were isolated from the intestinal content and the epithelium of the caecum and colon of 4 of 8 swine. All of the isolates belonged to the same species. This species was resistant to digitonin and polyanethol sulfonate and was able to ferment glucose, hemolyse erythrocytes and lyse horse serum. For testing the cholesterol requirement the strain 4 A 11 was selected which was independent of cholesterol. The agent was different in the immunofluorescence test from the mollicutes reported previously in swine and quite different in its nutritional requirements from cholesterol-independent mollicutes isolated from the rumen of cattle and sheep. Thus the isolated mollicutes seem to represent a new species.

Animals↗
PubMed1988

The effects of Mycoplasma mobile 163 K on the ciliary epithelium of tracheal organ cultures.

Mycoplasma (M.) mobile 163 K, isolated from the gills of a tench (Tinca tinca L.), was examined for cytotoxic capacities using tracheal organ cultures from gnotobiotic rats and gnotobiotic piglets in pH-controlled experiments (pH 7.2-7.6). The mycoplasmas caused an inhibition of the ciliary activity at incubation temperatures of 20, 25 and 30 degrees C. The strongest cilia stopping effect was observed at an incubation temperature of 25 degrees C, the optimal growth temperature of the mycoplasmas. No ciliostasis occurred at 37 degrees C. The number of the organisms did clearly affect the severity of ciliostasis in the range from 4.0 x 10(4) to 7.7 x 10(8) c.f.u. in rat as well as in porcine tracheal organ cultures. Toxic substances, secreted by the mycoplasmas into the culture medium, could not be detected. In histological investigations cytopathological changes were observed in the epithelial cells, apparent in the destruction and loss of cilia, cytoplasmatic vacuolization, swelling of mitochondria, peripheral orientation of the nuclear chromatin and detachment of epithelial cells from each other and the basal membrane. The final stage of the infection was characterized by complete exfoliation of the epithelial cells and the complete destruction of the multi-layer epithelium. The localization of the mycoplasmas attached to the ciliary epithelium was shown by scanning and transmission electron microscopy.

Animals↗
PubMed1988

The surface layer of Mycoplasma mobile 163K and its possible relevance to cell cohesion and group motility.

Mycoplasma mobile strain 163K tends to move in multicellular configurations, either as pairs or small groups of three or more cells, or as chain-like aggregations or microcolonies. Such wandering groups arise by transient association of independently moving cells. This behaviour of M. mobile was microscopically investigated and documented by sequences of microcinematographic pictures, as well as by photomicrographically recorded motility tracks. The presence of an extracellular slime layer was demonstrated in thin sections, by negative staining and by scanning electron microscopy. The possible association of this layer with the cohesive properties of the mycoplasma cells, enabling the formation of wandering groups, is discussed and a calculation of the magnitude of the cohesive force is provided.

Cell Aggregation↗
PubMed1988

Characterization of membrane components of the flask-shaped mycoplasma Mycoplasma mobile.

The cell membrane of Mycoplasma mobile was isolated by either ultrasonic or French press treatment of intact cells. The membrane fraction contained all of the cellular lipids, but only one-third of cellular proteins and had a density of 1.14 g ml-1. The soluble fraction contained the NADH dehydrogenase activity of the cells, as well as a protein with an apparent molecular mass of 55 kDa that was phosphorylated in the presence of ATP. Lipid analyses of M. mobile membranes revealed that membrane lipid could be labelled by radioactive glycerol, oleate and to a much higher extent by palmitate but not by acetic acid. The membrane lipid fraction was composed of 54% neutral and 46% polar lipid. The major constituents of the neutral lipid fraction were free fatty acid, free cholesterol and cholesterol esters (45, 25 and 20%, respectively, of total neutral lipid fraction). The free cholesterol count was 13% (w/w) of total membrane lipids with a cholesterol:phospholipid molar ratio of about 0.9. Among the polar lipids, both phospho- and glycolipids were detected. The phospholipid fraction consisted of a major de novo-synthesized phosphatidylglycerol (approximately 63% of total phospholipids), plus exogenous phosphatidylcholine and sphingomyelin incorporated in an unchanged form from the growth medium. The glycolipid fraction was dominated by a single glycolipid (approximately 90% of total glycolipids) that was preferentially labelled by palmitic acid and showed a very high saturated:unsaturated fatty acids ratio.

Bacterial Proteins↗
PubMed1988

Rheotactic behavior of a gliding mycoplasma.

Mycoplasma mobile, a new gliding mycoplasma isolated from the gills of a fish, was capable of positive rheotaxis; the cells glided upstream in a moving fluid. To our knowledge this is the first demonstration of rheotactic behavior among the procaryotes.

Animals↗
PubMed1987

Pathogenicity of Mycoplasma capricolum in sheep after experimental infection.

Mycoplasma (M.) capricolum has been frequently isolated from diseased as well as from healthy sheep in Morocco. In order to determine its pathogenicity for sheep, experiments were performed in three trials with the Moroccan isolate 012. The following results were obtained: Ewes inoculated intramammarily developed acute mastitis; the organism was transmitted to lambs suckling these ewes. Only a mild mastitis appeared after a second inoculum, performed 5 weeks after the first. Young lambs, 1 month of age, fed four times with M. capricolum broth culture, died during the septicemic phase, showing a generalized septicemia, polyarthritis and a diffuse interstitial pneumonia. Lambs, 2 and 3 months of age inoculated intrabronchially developed a disease, which appeared to be age and weight dependent. The more susceptible animals died within 1-2 weeks after infection. The older lambs recovered gradually from the disease, which was characterized by pneumonia, conjunctivitis and arthritis. A significant increase of antibodies against M. capricolum developed in the older animals in the complement fixation test.

Animals↗
PubMed1987

Interaction of Mycoplasma mobile 163K with erythrocytes.

Mycoplasma (M.) mobile 163K isolated from fish was investigated for its hemadsorbing, hemagglutinating, and hemolysing capacities and for its ability to adhere to erythrocytes. Hemadsorption to the colonies of M. mobile occurred with ovine, bovine, equine, trout, and carp erythrocytes and was inhibited by treatment of the mycoplasmas with substances acting on proteins (pronase, trypsin, glutaraldehyde), heat, UV-irradiation and homologous antiserum. Hemadsorption could be prevented also by treatment of the erythrocytes with neuraminidase. In liquid medium ovine erythrocytes were agglutinated and afterwards lysed by M. mobile. The erythrocytes which were adsorbed to the colonies of M. mobile were finally lysed also. Darkfield preparations showed the ability of M. mobile to adhere to erythrocytes and also its hemagglutinating properties.

Animals↗
PubMed1987

The influence of various substances on the gliding motility of Mycoplasma mobile 163K.

Non-toxic concentrations of various substances were tested for their influence on the gliding motility of Mycoplasma mobile 163K. A significant inhibitory effect on motility was observed with agents acting on nucleic acid synthesis (mitomycin), protein synthesis (puromycin, chloramphenicol), energy metabolism (p-chloromercuribenzoate, iodoacetate) and with compounds reacting with the cytoplasmic membrane or contractile elements (albumin, cholesterol, EDTA, 2-propanol, procain, CaCl2, MgCl2, colchicin and KI). The surface-active compounds Triton X-100, Tego and SDS increased the gliding velocity significantly in some concentrations and incubation periods. The results suggest that the motility of M. mobile depends on a functional cytoplasmic membrane and that cytoskeletal elements are involved in the gliding mechanism.

Anti-Bacterial Agents↗
PubMed1987

Gliding motility of Mycoplasma sp. nov. strain 163K.

The gliding movements of Mycoplasma sp. nov. strain 163K cells were characterized by photomicrographic and microcinematographic studies. The capability of gliding proved to be a very stable property of strain 163K. Cells were continuously moving, without interruption by resting periods, on glass as well as on plastic surfaces covered with liquid medium. Gliding cells always moved in the direction of their headlike structure; their course did not indicate any preference for a certain direction. Under appropriate growth conditions, cells showed linear and circular movements. Under inadequate conditions, cells glided in narrow circles or entered into zigzag trembling and tumbling movements. Organisms glided as single cells, in pairs, and in multicellular configurations. Movement patterns and gliding velocity were significantly affected by the cultivation and preparation time, the medium viscosity, and the storage and observation temperature. The number of passages on artificial media and the composition of the media used did not have a striking influence on gliding motility, but movements were effectively inhibited by homologous antiserum. The data obtained suggest that at least some of the structures associated with gliding are heat sensitive and located on the cell surface, that the gliding mechanism requires an intact energy metabolism, and, finally, that gliding motility is an extremely stable genetic property of Mycoplasma sp. nov. strain 163K.

Culture Media↗
PubMed1986

[Union of the male and female--in partnership. Illustrated by interpretations and demonstrations from Hinduism and Tantric Buddhism].

Following the originally dominant matriarchate, patriarchy took over and still reigns in present-day society, although we are now in the midst of a period of transition towards a man/woman relationship on partnership basis. This principle of "two units combining to form one", this unification of two opposing and complementary principles has been depicted in a model manner in the iconography of Hinduism and Tantric Buddhism. The attributes of these religions are described with the help of characteristic pictures and sculptures.

Buddhism↗