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Biomedical subjects

K A Bisset

Publications and source records attributed to K A Bisset.

16 recordsLinked to original sources
PubMed1981

Isolation of Bacillus licheniformis var. endoparasiticus from the blood of rheumatoid arthritis patients and normal subjects.

Sixty-five samples of blood from patients with rheumatoid arthritis and 94 from control subjects were examined by multiple culture and monthly subculture for periods of up to 33 months to detect the revision stages of Bacillus licheniformis var. endoparasiticus (BLE), which exists as L-forms in blood. Isolation of BLE were obtained more often from the blood of control subjects than from rheumatoid patients during the first 6 months of incubation, when there was clustering of positive cultures within samples. Thereafter, the isolation rate was similar for the two groups and positive cultures were distributed randomly between samples. Isolation of diphtheroid intermediate reversion stages (phase A and B) occurred mainly during the first year of incubation, but isolations of the fully reverted sporing bacillus (phase C) increased in frequency with incubation time, particularly from cultures with a high rate of desiccation during prolonged incubation. The proportion of different phases of BLE amongst the isolates and the distribution of the phases with incubation time were similar for the rheumatoid-arthritis patients and the normal subjects.

Arthritis, Rheumatoid↗
PubMed1979

Induction of reversion from the L-form to the sporogenous phase of Bacillus licheniformis var. endoparasiticus (Benedek).

The rate of reversion from the L-form to the complete bacillus phase of Bacillus licheniformis var. endoparasiticus (BLE)was increased by a factor of c. x20, by growth in the presence of 1% diaminopimelic acid in a well plate, and c. x25 with a 1% hog gastric mucin spread on the plate surface. Saturated riboflavin solution and growth products of staphylococci in wells had a lesser effect. The revertants were subsequently stable when isolated in the absence of additive. The rate of reversion from a spheroplast to a diphtheroid phase was not significantly altered by these additives. These findings are of practical value in studies to distinguish between the BLE sporing bacillus and postulated phases of the organism that include diphtheroid and spheroplast L-forms and debated mycoplasma-like forms.

Animals↗
PubMed1979

Electron microscopy of the L-cycle in Bacillus licheniformis var. Endoparasiticus (Benedek).

Electronmicrographs of sections show that the L-phases of Bacillus licheniformis var. endoparasiticus (Benedek) simulate the various types of micro-organism described by previous workers as associated with ostensibly noninfective conditions, notably cancer and arthritis; e.g., mycoplasmas, mycobacteria, corynebacteria and actinomycetes. The stages of the L-cycle, from spheroplasts through smaller and larger 'diphtheroid' bacteria to the fully reverted sporogenous bacillus, differ from one another mainly in their degree of reconstitution of the cell envelopes. Occurrence in 'diphtheroids' of nonresistant, cell-wall-deficient spore-like bodies, confirms their relationship with the true sporing bacillus stage. Large, swollen forms appear to be mother cells of minute stages.

Bacillus↗
PubMed1978

The isolation and characters of L-forms and reversions of Bacillus licheniformis var. Endoparasiticus (Benedek) associated with the erythrocytes of clinically normal persons.

Thirty-eight strains of the Gram-positive bacterium identified as Bacillus licheniformis var. endoparasiticus (Benedek), referred to as BLE, were isolated in various stages of reversion form the L-forms, from 28 out of 100 samples of whole blood or erythrocytes from normal healthy subjects, after prolonged incubation. Similar results were obtained from 100 samples from hospital patients with conditions not usually associated with blood infection. BLE was isolated from only one of 125 samples of plasma, including those separated from infected erythrocytes. Isolates from cultures incubated for up to 4 months were usually in the form of spheroplasts or diphtheroid bacilli; the fully reverted phase, resembling B. licheniformis, with the capacity to form endospores, was isolated occasionally from cultures aged 1--6 months, and it constituted about half the isolates recovered from cultures aged 6--25 months. BLE was isolated in subculture, and with the usual frequency, in previously unopened, primary cultures. It did not occur in 1200 subcultures of 150 control cultures made with autoclaved or irradiated blood cells; it was not detected in the environment of the laboratory or blood-sampling areas, or on the skin or in the respiratory passages of the operators and other persons associated with the laboratory, where typical, saprophytic B. licheniformis was very rare. It is concluded that this Bacillus species exists as an L-form, associated with the erythrocytes of a large proportion of normal persons, as previously recorded by several observers. Some of the morphological variants associated with the L-cycles have in the past been described as different organisms, for example L-forms of various bacteria or mycoplasmas, and the diphtheroid stage has been thought to belong to the genera Corynebacterium and Listeria. The sporogenous stage, although frequently described, has normally been discounted as a contaminant. These observations do not admit of any conclusion in respect of the claims that such bacteria may have a role in arthritis, cancer or other diseases.

Bacillus↗
PubMed1976

Nuclear activity and cell division in the microcysts of Myxococcus fulvus demonstrated by electron micrography of sections.

Electron micrographs of sectioned fruiting bodies confirm that, in Myxococcus fulvus, approximately 10% of mature microcysts show appearances interpretable as typical bacterial nuclear activity and cell division. This suggests a simple mechanism for fruiting body development, and its existence bears upon the validity of the classical descriptions of microcyst maturation in myxobacteria.

Cell Division↗
PubMed1976

A continuous study of morphological phase in the swarm of Proteus.

Continuous study, at intervals of 1 h, on the advancing edge of the swarm of Proteus vulgaris confirms that this is almost permanently composed of elongated swarmers, and that short, non-swarming forms arise in the interior of the culture where motion has already ceased. Previous errors have probably arisen from inaccurate sampling.

Movement↗
PubMed1976

Development of concentric zones in the Proteus swarm colony.

Two main mechanisms of concentric ring formation in cultures of Proteus species are described. One of these is the classically accepted method, wherein rings are produced as the advance of the swarm stops and recommences. In the other, the ring is produced as a fold inside the colony. These are considered to be extremes of a spectrum of growth types, the common feature being that rings are formed by piling-up of growth, and this process is not always directly correlated with morphological change in the individual bacteria, or with cessation of advance of the swarm. The validity of the presently accepted theories of ring formation and swarming in general are thus called into question.

Models, Biological↗