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Biomedical subjects

S Hammarström

Publications and source records attributed to S Hammarström.

At least 199 records · Page 11Linked to original sources

Transferrin can replace serum for in vitro growth of mitogen-stimulated T lymphocytes.

Activation of human T cells by mitogens was compared in cultures containing serum, human serum albumin or purified human transferrin as growth support. The mitogenic effect of the lectins leucoagglutinin, concanavalin A and Wistaria floribunda agglutinin was measured as incorporation of [3H]thymidine into the cellular DNA of the lymphocytes. Three different preparations of transferrin were all able to fully substitute serum or serum albumin as growth promotors, when present at concentrations of 10 microgram/ml or more. A small contamination of transferrin in the human serum albumin preparations used was shown to be responsible for their growth-supporting effect, while no need for the presence of albumin itself could be demonstrated.

Cells, Cultured↗

Helix pomatia a hemagglutinin, a surface marker for bovine T-lymphocytes.

Bovine peripheral blood lymphocytes (PBL) were isolated from blood collected from 6 cattle. After treatment with neuraminidase, 40 or 60% of the cells were shown to combine with Helix Pomatia A hemagglutinin (HP) depending whether a direct or indirect fluorescence technique was used. About 20% of the cells were Ig-bearing. With double staining fluorescence technique, it was shown that cells attaching to HP were not Ig-bearing and the reverse. With the aid of HP, covalently bound to Sepharose, Ig-bearing cells could be separated from cell populations attaching to HP. The fraction of cells forming rosettes with sheep erythrocytes was proportional to that of HP attaching cells both before and after fractionation on the HP column. It is therefore concluded that HP is a marker for bovine T-cells, and that this lectin may be used to separate B-cells from T-cells.

Animals↗

Leukotriene C: a slow-reacting substance from murine mastocytoma cells.

Murine mastocytoma cells treated with calcium ionophore A23187 produced a slow-reacting substance (SRS) that caused guinea pig ileum to contract. The response was reversed by the SRS antagonist FPL 55712. On the basis of isotope incorporation experiments, spectroscopy, and chemical degradations, the SRS was identified as a cysteine-containing derivative of 5-hydroxy-7,9,11,14-icosatetraenoic acid. This amino acid was attached in thioether linkage at C-6. The SRS is structurally related to previously identified epoxy and dihydroxy metabolites of arachidonic acid in leukocytes. A common feature is the presence of a conjugated triene, and the name "leukotriene" has been introduced to designate these compounds. Leukotriene A (5,6-epoxy-7,9,11,14-icosatetraenoic acid) is an intermediate in the formation of leukotriene B (5,12-dihydroxy-6,8,10,14-icosatetraenoic acid) and is proposed to be a precursor also of leukotriene C, which is the SRS identified here.

Animals↗

Immunofluorescence studies on the occurrence and localization of the CEA-related biliary glycoprotein I (BGP I) in normal human gastrointestinal tissues.

Biliary glycoprotein, I(BGP I) is a carcinoembryonic antigen (CEA) cross-reactive glycoprotein of normal human bile. Its occurrence and localization was studied in normal human gastrointestinal tissues by means of direct immunofluorescence using immunadsorbent purified BGP I antibodies with high selectivity for BGP I, as compared to CEA and 'non-specific cross-reacting antigen' (NCA). As controls fluorescein-labelled CEA and NCA were used. Specific BGP I fluorescence was only found in the biliary tract, i.e. in bile canaliculi, in the lumen of large bile ducts and on the surface of the gall bladder mucosa. No fluorescence was found in the hepatocytes or in the cells lining larger bile ducts or the gall bladder. Fluorescence probably due to cross-reaction with NCA was obtained in the cytoplasm of macrophages in different organs and on the surface of bowel epithelium.

Adult↗

Elevated serum levels of a biliary glycoprotein (BGP I) in patients with liver or biliary tract disease.

Human hepatic bile contains a glycoprotein (biliary glycoprotein I, BGP I) which cross-reacts with the carcinoembryonic antigen (CEA). A radioimmunoassay for BGP I was developed. The interference of CEA or 'non-specific cross-reacting antigen' (NCA) in the assay was small. The serum levels of BGP I were determined in healthy subjects, in patients with hepato-biliary diseases and in patients with various infectious or inflammatory disorders. Healthy individuals, including pregnant women, had a serum BGP I concentration of about 0.5-1 mg/l. Diseases of the liver or biliary tract (e.g. hepatitis A or B, cytomegalovirus hepatitis, obstructive jaundice or primary biliary cirrhosis) were associated with elevated serum levels of BGP I, as opposed to infectious diseases not affecting the liver mostly showing values within the normal range. Raised levels of serum BGP I activity may reflect biliary obstruction as a result of interference with normal BGP I secretion to the bile.

Adolescent↗