Search PubMed⌕ Search

Biomedical subjects

H R Colten

Publications and source records attributed to H R Colten.

At least 163 records · Page 9Linked to original sources
PubMed1978

The first component of complement. A quantitative comparison of its biosynthesis in culture by human epithelial and mesenchymal cells.

Epithelial and mesenchymal cells synthesized and secreted all three subcomponents of the first component of complement (C1): C1q, C1r, and C1s. Quantitatively, however, columnar and transitional epithelial cells secreted 400--3,700 times more hemolytically active C1 than monocytes or fibroblasts. Only columnar epithelial cells synthesized C1 subcomponents with subunit structures similar to their serum counterparts. Transitional epithelial cells, fibroblasts, and monocytes produced C1q and C1s with subunits of apparent molecular weights larger than reported values. C1r from all cell lines was physiochemically similar to serum C1r.

Cells, Cultured↗
PubMed1977

Biosynthesis of pro-C3, a precursor of the third component of complement.

A precusor of the third component of complement, pro-C3, was detected in studies of cell-free synthesis and intracellularly in homogenates of liver tissue cultures. The molecular weight of pro-C3 was indistinguishable from that of intact native C3 secreted in vitro by liver or peritoneal macrophages, but its structure was different. Pro-C3 is a single polypeptide chain, whereas C3 secreted by cells in culture consists of two polypeptide chains (mol wt 120,000 and 76,000) linked by disulfide bonds.

Animals↗
PubMed1977

Delayed cold-induced urticaria: a dominantly inherited disorder.

A delayed cutaneous response to cold, characterized by areas of erythematous, edematous deep swelling at 9 to 18 hr after experimental ice challenge, was recognized in a 10-yr-old boy and several members of his family. Biopsy of the cold-induced lesion showed edema and an infiltrate of mononuclear cells; mast cells were normal, and immunoglobulins, complement factors, and fibrin were not detected by immunofluorescence techniques. Local cold challenge did not release histamine or induce alterations in the complement system or the enzymes, histaminase, and histamine methyl transferase. The delayed cutaneous response to cold could not be passively transferred with serum or tissue extracts to monkey skin. Family studies suggested an autosomal-dominant mode of inheritance.

Amine Oxidase (Copper-Containing)↗
PubMed1977

Hypersensitivity to pancreatic extracts in parents of patients with cystic fibrosis.

Because immediate hypersensitivity reactions can occur in individuals exposed to powdered pancreatic extracts, 36 patients with cystic fibrosis and 51 patents of such patients wwer studied for evidence of sensitization. Sensitivity to the extracts as evidence by history and skin testing was infrequent in the children with cystic fibrosis. However, skin testing for immediate hypersensitivity with either crude pancreatic extracts or inactivated trypsin correlated well in their patents with a history of clinical symptoms. IgE mediation of these reactions in sensitized individuals was demonstrated by antigen-induced histamine release from leukocytes, passive transfer studies, and immediate response to inhalation challenge.

Adult↗
PubMed1977

Immediate hypersensitivity to cockroach. Isolation and purification of the major antigens.

Crude cockroach extract elicited positive skin tests in 50% of patients with positive and in 4% with negative environmental history for cockroach exposure, suggesting a possible role of cockroach in perennial atopic disease. Three major allergens in crude American and German cockroach extracts have been identified using sequential purification steps on Sephadex G-75, diethylaminoethyl (DEAE) cellulose, and agarose gel electrophoresis. Cr-I elicits positive skin tests in 70% of patients sensitive to the crude extracts. It has a molecular weight of approximately 25,500 daltons, is highly acidic, and resists boiling for four hours. Boiling in 4 N acetic acid completely abolishes its allergenicity. The purified allergen elicits positive skin tests at a concentration of 3 mug/ml and is capable of inducing greater than 50% histamine release from sensitive leukocytes at 0.05 ng/ml. A second antigen, Cr-II, elicits positive skin tests also in approximately 70% of cockroach-sensitive individuals, has a molecular weight of approximately 63,000 to 65,000 daltons, and has similar heat stability and acid hydrolysis characteristics to Cr-I. A third, less well-characterized antigen, Cr-III, has a molecular weight less than 10,000 daltons and elicits positive skin tests in 30% of individuals sensitive to the crude extract.

Acetates↗
PubMed1977

Cell-free synthesis of the fourth component of guinea pig complement (C4): identification of a precursor of serum C4 (pro-C4).

Polysomes (S-20) from homogenates of guinea pig liver synthesized serum albumin and a precursor of the fourth component of guinea pig complement (C4) in vitro. The C4 precursor (pro-C4) accounted for approximately 0.2% and albumin 4% of the radiolabeled protein precipitable by trichloroacetic acid and not bound to polysomes. Pro-C4 is a single polypeptide chain (molecular weight 200,000) which is then converted to C4, a three-chain (molecular weights 95,000, 78,000 and 31,000) structure linked by interchain disulfide bridges. Pro-C4 was also detected intracellularly in short-term tissue cultures of guinea pig liver. C4 was found in the medium harvested from these cultures.

Animals↗
PubMed1977

Biosynthesis of the third component of complement (C3) in vitro by monocytes from both normal and homozygous C3-deficient humans.

Human monocytes synthesized the third component of complement (C3) up to 5 wk in vitro. Evidence for net C3 synthesis was based on (a) incorporation of 14C-labeled amino acids into C3 protein, (b) indentity of the allotype of C3 produced in vitro with that of the doner's serum C3, even in the presence of carrier C3 protein of a different allotype; (c) correspondence of electrophoretic mobility, size, and subunit structure of C3 protein produced in vitro with serum C3; (d) inhibition of C3 production with cycloheximide. Monocytes from two unrelated C3-deficient patients were studied under conditions that supported C3 synthesis by normal monocytes. Serum from each of the patients contained less than 1% of the normal C3 concentration, buth their monocytes produced C3 at approximately equal to 25% of the normal rate when studied after 2 wk in vitro. The C3 produced in vitro by monocytes from one of the patients had the molecular weight of normal serum C3 and dissociated appropriately under reducing conditions. Monocytes from C3-deficient patients could not be distinguished from normals on the basis of morphology, rosetting with C3-coated erythrocytes, or rates of C2, and total protein synthesis.

Blood Proteins↗
PubMed1977

Histaminase release from human eosinophils.

Phagocytosis of opsonized zymosan by human eosinophils results in a dose-dependent noncytotoxic release of histaminase as well as arylsulfatase and beta-glucuronidase. The calcium ionophore A23187 also stimulates release of eosinophil histaminase at concentrations of ionophore which barely release arylsulfatase and beta-glucuronidase. Zymosan-induced histaminase release from eosinophils but not from neutrophils was abolished or markedly reduced in the presence of cytochalasin B, suggesting a difference in the mechanisms of histaminase release from the two granulocyte cell types.

Amine Oxidase (Copper-Containing)↗
PubMed1976

Histaminase release from human granulocytes.

Histaminase (EC-1.4.3.6), one of the two catabolic enzymes for histamine, is contained in human granulocytes. Opsonized zymosan or the calcium ionophore A-23187 induce a dose-dependent release of histaminase from human granulocytes in vitro. Release is completed within 30 min, is temperature dependent, and requires divalent cations. Opsonized zymosan-induced histaminase release was maximal in the presence of both calcium and magnesium, whereas ionophore release was magnesium independent. The total cellular content of histaminase could be released by both opsonized zymosan and ionophore. In contrast, only 25% of the cellular beta glucuronidase, a lysosomal enzyme, was released after maximal stimulation with opsonized zymosan; there was minimal release of beta glucuronidase with ionophore. Zymosan- and ionophore-induced histaminase release was inhibited by agents that are presumed to interfere with cell metabolism and disrupt microtubules. Human granulocytes therefore may modulate the effect of histamine by releasing histaminase at a site of inflammation. Studies of granulocyte histaminase release in vitro may also provide a new model to explore granulocyte function and secretion.

Amine Oxidase (Copper-Containing)↗
PubMed1976

Synthesis of the second component of complement by long-term primary cultures of human monocytes.

A method has been developed for preparation of confluent monolayers of human monocytes from small volumes of blood and for maintenance of these pure monocyte cultures for up to 16 wk in vitro. These cells phagocytosed 5.7 mum diameter latex beads, rosetted with erythrocytes coated with IgG or with C3, killed Listeria monocytogenes, and synthesized both lysozyme and the second component of complement. Lysozyme was secreted at a rate of approximately 50,000 mol/min per cell for at least 12 wk in cultures. The maximal rate of C2 synthesis and secretion was considerably less; i.e., approximately 30 mol/min per cell between the 2nd and 12th wk in culture. Monocytes produced little C2 during the first 6 days in culture after which a marked increase in the rate of C2 production was noted. This increase was coincident with morphologic evidence of monocyte maturation.

Bacteriolysis↗
PubMed1976

Histamine metabolism. II. Cellular and subcellular localization of the catabolic enzymes, histaminase and histamine methyl transferase, in human leukocytes.

Histaminase (EC 1.4.3.6) activity has been demonstrated in human eosinophils and neutrophils, but not in mononuclear cells, with the use of a new and specific thin-layer radiochromatographic enzyme assay. Leukocyte histaminase was physicochemically and functionally similar to histaminase isolated from human placenta and was principally localized to the 27,000-g granule-rich fraction of eosinophil and neutrophil homogenates. Histamine methyl transferase (EC 2.1.1.8), on the other hand, was detected in monocytes but not in granulocytes, eosinophils, lymphocytes, or platelets, and was localized solely to the 100,000-g cell sap supernatant fraction. These data suggest a role of human leukocytes in the catabolism of histamine and therefore in the modulation of histamine-mediated inflammatory reactions.

Amine Oxidase (Copper-Containing)↗