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Biomedical subjects

M Thornton

Publications and source records attributed to M Thornton.

At least 55 records · Page 3Linked to original sources
PubMed1984

The role of antibody and complement in the cellular response to Trypanosoma congolense.

The in vitro cytotoxic response of bovine granulocytes and monocytes and of murine peritoneal macrophages against Trypanosoma congolense in the presence of antibody, antibody plus complement or complement alone was assessed using luminol aided chemiluminescence as a second parameter for effector cell activation. Neither cell type exhibited any trypanolysis exceeding that of antibodies and complement alone. The kinetics of the chemiluminescence response in the course of these reactions closely correlated with the trypanocidal activity of the antibody preparation used, suggesting effector cell activation as a response to antibody-mediated immobilization and damage of the trypanosomes. From these results and electron microscopic investigations we conclude that antibody- or complement-dependent cell-mediated cytotoxic reactions do not play a significant role in the defence of T. congolense infection, neither by extracellular lysis nor killing of ingested parasites.

Animals↗
PubMed1983

Killer-cell lines derived from mouse thymus, resembling large granular lymphocytes and expressing natural killer-like cytotoxicity.

Murine thymus cells were maintained in vitro with supernatant-factors derived from Concanavalin-A-stimulated spleen cells. After an initial phase of vigorous proliferation, large granular cells (GC), which were not observed in fresh thymus cell preparations, appeared in these cultures. GC, derived from C3Hf/Tif-, BALB/c-, and C57BL/10-thymus cultures, could be slowly expanded and have been maintained as increasingly homogeneous (oligoclonal) lines for up to six months. During this time, other types of thymus cells died or were diluted out. Thymic GC differ functionally and histochemically from macrophages and mast cells. They do not phagocytize zymosan particles, bind opsonized SRBC, express nonspecific esterases or contain detectable amounts of histamine. GC share many features with natural killer (NK) cells and large granular lymphocytes (LGL). One morphologically representative line (C3Hf/Tif) had the following surface phenotype: Thy-1+, Lyt-1-, Lyt-2-, H-2K+, I-A-, asialo Gm1+. GC bind peanut agglutinin (PNA) on their surface and contain azurophilic granules. These cytoplasmic granules are considerably larger than those in LGL. Cells of a GC line derived from mouse strain C3Hf/Tif (H-2k) lysed the NK-sensitive YAC-1 (H-2a) and EL-4 (H-2b), but not the NK-insensitive P815 cells.

Animals↗
PubMed1979

Comparative study of the dopamine-sensitive adenylate cyclase in the striatum and hypothalamus of rat brain.

Stimulation by dopamine of adenylate cyclase in homogenates of rat brain striatum was enhanced in the presence of ATP (0.6--3 mM) and GTP (10--100 micrometer). The stimulation by dopamine appeared to be the result of its antagonism of inhibition of adenylate cyclase by GTP or higher concentrations of ATP. Stimulation of the enzyme by dopamine was also dependent on MgCl2, and was maximal at MgCl2 concentrations of at least two fold excess over ATP. While ATP did not inhibit adenylate cyclase in homogenates of the ventral hypothalamus, GTP (10--100 micrometer) significantly stimulated it. Dopamine stimulated the adenylate cyclase in the hypothalamus. This action was blocked by chlorpromazine (10 micrometer) and phentolamine (100 micrometer) but not by an analogue of chlorpromazine having no neuroleptic activity or by propranolol (100 micrometer).

Adenosine Triphosphate↗
PubMed1978

Assessment of the nutritional state of patients with an intestinal fistula.

The arm muscle area, derived fat-free mass, urinary excretion of 3-methylhistidine and creatinine were measured serially in a group of patients with an intestinal fistula receiving prolonged nutritional support. While the two anthropometric tests appeared reasonable indicators of changes in muscle mass in these patients, the marked intra-individual variability in excretion of 3-methylhistidine and creatinine created problems in interpretation. It is suggested that more use be made of serial anthropometry in district general hospitals as an alternative, simple, measure of nutritional status.

Adolescent↗