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Biomedical subjects

J Dorling

Publications and source records attributed to J Dorling.

At least 19 recordsLinked to original sources
PubMed1980

Where do those slides go?

The Foundation for Teaching Aids at Low Cost (TALC) distributes about 1000 lecture units of slides and scripts each month. This paper reports on the results of a postal enquiry to a stratified sample of those who receive these lecture units. The response to the enquiry was good, and showed a wide and varied use of this material, each set may be seen by around 140 students in the year after despatch.

Attitude↗
PubMed1980

Kinetics of fusion of the cytoplasmic granules with phagocytic vacuoles in human polymorphonuclear leukocytes. Biochemical and morphological studies.

This study on human neutrophils was conducted to measure the kinetics of degranulation of the different cytoplasmic granules into phagocytic vacuoles, and to relate the timing of these events to the burst of respiration that accompanies phagocytosis by these cells. Purified neutrophils were incubated with latex particles opsonized with human immunoglobulin (Ig)G, and phagocytosis was stopped at timed intervals. The cells were examined by electron microscopy to document the sequence of degranulation of the cytoplasmic granules. The azurophil granules and lyosomes were identified by histochemical staining for peroxidase and acid phosphatase, respectively. Phagocytic vacuoles were separated from cell homogenates by floatation on sucrose gradients and assayed for contained lactoferrin, myeloperoxidase, and acid hydrolases. The conclusions drawn from the biochemical and morphological studies were in agreement and indicated: particle uptake and vacuole closure can be completed within 20 s; both the specific and azurophil granules fuse with the phagocytic vacuole much earlier than is generally appreciated, with half-saturation times of 39 s (99% confidence limits, 15-72); oxygen consumption has kinetics similar to those of the fusion of these granules with the phagosome; degranulation of the acid hydrolases beta-glucuronidase, N-acetyl-beta-glucosaminidase (biochemical assays), and acid phosphatase (biochemical assay and electron microscopic cytochemistry) have kinetics of degranulation that are similar to each other but totally different from and much slower than that of myeloperoxidase with half-saturation times of between 354 and 682 s (99% confidence limits, 246-883). This suggests that the acid hydrolases are not co-located with myeloperoxidase in the azurophil granule but are contained in distinct lysosomes, or "tertiary granules".

Cytoplasmic Granules↗
PubMed1979

Halothane does not inhibit human neutrophil function in vitro.

Various indices of function of neutrophils from normal healthy volunteers have been examined after in vitro exposure to halothane. Random free movement on glass was unaffected, but random migration through millipore filters was slightly increased. There was no significant change in migration in response to casein chemotaxis. Phagocytosis, degranulation and the enhanced non-mitochondrial respiration associated with phagocytosis were unaffected. Electron-microscopic appearance at 30 s after exposure to latex particles was normal in all respects.

Cell Movement↗
PubMed1976

Anti-streptococcal antibodies reacting with brain tissue. II. Utrastructural studies.

The reaction of rabbit anti-Streptococcus pyogenes type 24 with mouse brain has been studied at the ultrastructural level using horseradish peroxidase labelled antiglobulin. It is shown that these antibodies, and by inference those found in Sydenham's chorea, react with the fibrous astrocyte. The cross-reacting antigen is the glial filament or a closely associated cytoplasmic constituent.

Animals↗
PubMed1976

Localization of smooth muscle-like contractile proteins in kidney by immunoelectron microscopy.

Contractile proteins of smooth muscle type were found in kidney cells by immunological methods. The reactions of rabbit anti-actin, anti-heavy meromyosin and anti-myosin antisera with rat kidney were investigated by immunoelectron microscopy. Anti-actin stained specifically the foot processes of epithelial cells in the glomerulus, the basal processes of tubular epithelial cells, and the cytoplasm of smooth muscle cells. Anti-heavy meromyosin stained the foot processes at their bases near the cell membrane and close to the basement membrane. Anti-myosin stained the cytoplasm of vascular smooth muscle cells. It is suggested that actin and heavy meromyosin-like proteins may act together to cause movement of foot process cytoplasm.

Actins↗
PubMed1971

Use of peroxidase-conjugated antiglobulin as an alternative to immunofluorescence for the detection of antinuclear factor in serum.

A method of detecting serum antinuclear factor by the use of antiglobulin conjugated with horseradish peroxidase has been compared with a standard procedure using a fluorescent label. The horseradish peroxidase conjugate was evaluated by block titration against positive serum and by its performance as a test reagent for screening and titrating sera. It is concluded that the horse-radish peroxidase method, in which an ordinary light microscope is employed, provides a satisfactory alternative to immunofluorescence for routine tests for antinuclear factor.

Animals↗