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Biomedical subjects

G B Naff

Publications and source records attributed to G B Naff.

28 records · Page 2Linked to original sources
PubMed1971

Glomerular deposition of properdin in acute and chronic glomerulonephritis with hypocomplementemia.

Kidney tissue from 97 patients was studied by immunofluorescent techniques using antiserum to purified properdin. All patients with acute poststreptococcal glomerulonephritis showed deposition of properdin and the third component of complement (C3), either as "humps" on the basement membrane, or in the mesangium. In all cases of chronic membranoproliferative glomerulonephritis, properdin and C3 were localized in the glomeruli, most commonly in a lobular pattern on the basement membrane. Activation of C3 by the properdin system may explain the depressed serum levels of C3 and terminal complement components even though levels of earlier components are normal, and the deposition of C3, often without immunoglobulins, in the kidneys of patients with acute glomerulonephritis or chronic membranoproliferative glomerulonephritis.

Acute Disease↗
PubMed1970

Deficiency of C1r in human serum. Effects on the structure and function of macromolecular C1.

THE EXPERIMENTS PRESENTED HERE UTILIZE A HUMAN SERUM MARKEDLY DEFICIENT IN HEMOLYTIC COMPLEMENT ACTIVITY TO SHOW THAT: (a) The hemolytic deficiency is the result of a selective deficiency in hemolytic C1. (b) The relative absence of hemolytic C1 is due to a profound deficit in C1r function associated with less than normal C1s protein and hemolytic function and normal C1q protein concentration and function. This deficit in C1r in the face of normal C1q suggests that different cell types are responsible for the synthesis of each of these components. (c) Whatever the basis for the deficiency of C1r function, this defect results in an inadequate association of the remaining C1 subcomponents, C1q and C1s, even in the presence of calcium ions, thus suggesting that C1r has an important role in the assembly and/or maintenance of macromolecular C1.

Adolescent↗
PubMed1969

The inhibition of plasmin, plasma kallikrein, plasma permeability factor, and the C'1r subcomponent of the first component of complement by serum C'1 esterase inhibitor.

The fraction of human serum designated as C'1 esterase inhibitor is known to inhibit the action of C'1 esterase, a plasma kallikrein, and PF/Dil, an enzyme in plasma enhancing cutaneous vascular permeability. In the present study, C'1 esterase inhibitor has been found to block the actions of plasmin and the C'1r subcomponent of the first component of complement, and to retard the generation of PF/Dil. No inhibition of blood clotting or of the generation of plasmin was demonstrable.

Alpha-Globulins↗
PubMed1968

The enzymatic nature of C'1r. Conversion of C'1s to C'1 esterase and digestion of amino acid esters by C'1r.

Human C'1, a macromolecular complex composed of three subunits, is the zymogen for at least two distinct enzymes. Preparations of one subunit, C'1r, functioned as a protease which converted another subunit, C'1s, to C'1 esterase. The conversion of C'1s to C'1 esterase by C'1r was blocked by Liquoid, phenyl methylsulfonyl fluoride, and calcium ions, but not by soybean trypsin inhibitor, hirudin, or heparin. Preparations of C'1r also possessed two additional functions, i.e., the ability to hydrolyze certain synthetic amino acid esters and to participate in immune hemolysis. Evidence was presented which indicates that these three functions are properties of a single entity, C'1r, but not of the same portion of its molecular structure. These observations suggest that C'1r has at least two active sites, one for its reaction with C'1q, an additional subunit of C'1, and one for its reaction with C'1s; together, the three subcomponents, C'1q, C'1r, and C'1s, form a single functional unit, the first component of complement.

Amino Acids↗
PubMed1967

The conversion of C'IS to C'1 esterase by plasmin and trypsin.

The formation of C'1 esterase from C'1, the first component of complement, may be brought about by the action of plasmin or trypsin upon C'1s, a subcomponent of C'1. These enzymes also decrease the esterolytic activity of C'1 esterase. The formation of C'1 esterase was demonstrated by measuring the appearance of an agent or agents with esterolytic properties and the capacity to inactivate C'2 and C'4, attributes of C'1 esterase. The activity of the agent which evolved was blocked by serum inhibitor of C'1 esterase. The implications of these observations, that the formation of C'1 esterase during complement fixation is mediated by proteolytic processes, are under study. The possible inhibition of C'1q by soybean trypsin inhibitor is in agreement with this hypothesis.

Animals↗