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Biomedical subjects

R Bartlett

Publications and source records attributed to R Bartlett.

16 recordsLinked to original sources
PubMed1992

Effect of blocking TNF-alpha on intracellular BCG (Bacillus Calmette Guerin) growth in human monocyte-derived macrophages.

Four agents, thalidomide, oxpentifylline, dexamethasone and a polyclonal anti-TNF-alpha antibody, were all shown by specific Elisa to block endogenous TNF-alpha production by Bacillus Calmette Guerin (BCG)-infected human monocyte-derived macrophages in in vitro culture. There was however no significant enhancement of intracellular BCG growth, over a 7-day incubation, in human monocyte-derived macrophages in the presence of any of the TNF-alpha-blocking agents, as determined by both radiometric and CFU counting methods of assessing bacterial viability and growth. The result suggests that the action of TNF-alpha alone is unlikely to be an important effector mechanism in antimycobacterial immunity within human cells.

Antibodies↗
PubMed1992

A comparison of the different methods available for determining BCG-macrophage interactions in vitro, including a new method of colony counting in broth.

Different methods of determining BCG viability based on colony forming unit (CFU) counting and radio-isotope labelling were comparatively assessed. These included radio-isotope labelling with [3H]uracil, [3H]uridine, [3H]glycerol, and CFU counting, by both agar plate dilution, and microcolony counting in broth. The sensitivity ranges of the different techniques were determined in both macrophage-free and macrophage-treated systems and used to assess the anti-mycobacterial potential of human monocyte-derived macrophages following BCG infection.

Colony Count, Microbial↗
PubMed1991

Involvement of p34cdc2 in establishing the dependency of S phase on mitosis.

Mutants of cdc2+ can disrupt the dependency of S phase on completion of the previous mitosis. By changing the state of p34cdc2 it is possible to reprogramme a cell from entering mitosis to undergoing S phase. This leads to the proposal that the cell cycle can be considered a p34cdc2 cycle, and has implications for the evolution of life cycles.

CDC2 Protein Kinase↗
PubMed1990

Yeast as a model system for understanding the control of DNA replication in Eukaryotes.

In the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, the initiation of DNA replication is controlled at a point called START. At this point, the cellular environment is assessed; only if conditions are appropriate do cells traverse START, thus becoming committed to initiate DNA replication and complete the remainder of the cell cycle. The cdc2+/CDC28+ gene, encoding the protein kinase p34, is a key element in this complex control. The identification of structural and functional homologues of p34 suggests that it has a role in the control of DNA replication in all eukaryotes. The WHI1+, CLN1+ and CLN2+ gene products, identified in S. cerevisiae, are positive regulators that function at START and may interact with p34. Determining how passing the START control point leads to the initiation of DNA replication is a major outstanding challenge in cell cycle studies.

CDC2 Protein Kinase↗
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↗
PubMed1979

Ticarcillin.

Explore the source record for details and available documents.

Humans↗
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↗
PubMed1978

Prediction of gentamicin serum levels using a one-compartment open linear pharmacokinetic model.

The accuracy of predicting serum gentamicin levels based on a one-compartment open linear pharmacokinetic model was studied. Twenty-two patients accounted for 59 serum gentamicin levels which were measured by microbiologic assay and compared with predicted serum levels determined by pharmacokinetic calculation. Seventeen serum levels were collected at peak times, 15 at trough time and 27 at times between peak and trough. Forty-nine of the levels were obtained from patients with impaired renal function. Predicated gentamicin levels correlated well with measured serum levels (r = 0.85, p less than 0.001). Of the measured levels, 56% were within +/- 1 microgram/ml of the predicted levels. Of 49 levels collected from patients with impaired renal function, 59% were within +/- 1 microgram/ml of the predicted level. In 13 patients from whom multiple serum gentamicin levels were collected and predictions based on half-life or elimination rate obtained by fitting the first level, 83% of the measured levels were within +/- 1 microgram/ml of the predicted level. The one-compartment open linear pharmacokinetic calculations can be used to adequately predict serum gentamicin levels. In patients with changing or diminished renal function, pharmacokinetic predictions may not be accurate, and actual serum level determinations may be needed to monitor gentamicin therapy.

Adult↗
PubMed1976

Effect of delay on culture of urine.

One hundred random urine specimens which were submitted for culture were planted using a calibrated loop within 2 h of collection and 2 and 4 h later after standing at room temperature. Colonies were counted after an 18- to 24-h incubation at 37 degrees C. Fifteen of the specimens demonstrated increases in counts exceeding 1 X log10; four increased from less than 10(5)/ml to greater than 10(5)/ml (three by the 4-h culture and a fourth by the 6-h culture), supporting the concept that delays of greater than 2 h in inoculating cultures may produce results which could cause errors in diagnosis.

Bacteria↗
PubMed1975

Acupuncture and placebo: Effects on delaying the terminating response to a painful stimulus.

An experiment was performed to determine whether needles inserted into appropriate acupuncture points could delay onset of a pain-terminating response more than needles inserted as placebos into inappropriate points could. A heat source contained in a modified Hardy-Wolff-Goodell dolorimeter was used as a stimulus to produce pain on the posterolateral aspects of the left forearms of volunteer subjects. Subjects pressed a switch as soon as pain was experienced, and the latency between stimulus onset and response was measured to the nearest hundredth of a second. Response latencies were recorded before and after needling, which included electrical stimulation. Needles placed in specific acupuncture points called Ho-Ku and Wai-Kaun delayed onset of the pain-terminating response slightly more than needles inserted as placebos. Even with needles in appropriate acupuncture points, analgesia was slight and subjects still experienced pain.

Acupuncture Therapy↗
PubMed1975

Activity of minocycline against Acinetobacter calcoaceticus var. anitratus (syn. Herellea vaginicola) and Serratia marcescens.

The activity of minocycline and tetracycline against 23 isolates of Acinetobacter calcoaceticus var. anitratus (syn. Herellea vaginicola) and 178 strains of Serratia marcescens was determined by disk and microdilution methods. The results indicate that minocycline is highly active against this species of Acinetobacter, all but one strain being inhibited by 0.007 mug of the antibiotic per ml. Tetracycline was also active, though to a lesser degree, against A. calcoaceticus. Of the 178 strains of S. marcescens tested, only seven (3.9%) had a minimum inhibitory concentration of 2 mug or less of minocycline per ml. Tetracycline was less active than minocycline against S. marcescens; with 2 mug of tetracycline per ml, only 2 of 152 (1.3%) strains were inhibited. At concentrations of 8 and 16 mug of minocycline per ml, which can be achieved in the urine with the usual doses, 44.9 and 63.5% of S. marcescens strains were inhibited, which implies its possible usefulness for the therapy of urinary tract infection due to this organism.

Acinetobacter↗
PubMedDate not supplied

Myocardial contusion. Using the index of suspicion for assessing blunt chest trauma.

The body of literature devoted to the diagnosis and treatment of the patient with myocardial contusion (MC) frequently references the "index of suspicion" to qualify those patients at risk for cardiac embarrassment. Absent from this literature, however, is discussion of the importance of diligent nursing assessment and monitoring of these patients. This article shows the relevance of the index of suspicion to the nursing assessment of patients suspected of myocardial injury from blunt chest trauma.

Adult↗