PubMed Health⌕ Search

Biomedical subjects

K Nagaki

Publications and source records attributed to K Nagaki.

15 recordsLinked to original sources
PubMed1979

[Complement system].

Explore the source record for details and available documents.

Complement Activation↗
PubMed1979

Deficiency of the ninth component of complement in man.

The studies of serum from a case with C9 (the ninth component of complement) deficiency are described. A 29-year-old woman in good health was found to have low serum complement levels (CH50). C9 of her serum was undetectable by the hemolytic assay and by the immunochemical analysis but all other components were normal. It was demonstrated that low CH50 of her serum was due to the hemolysis of the sensitized sheep erythrocytes (EA) by the complement components from C1 to C8.

Adult↗
PubMed1978

Reaction mechanisms of beta1H globulin.

The reaction mechanisms of beta1H were studied. The generation of alternative pathway C3 and C5 convertases on the cell surface as well as in the fluid phase was inhibited by beta1H globulin. The cell preparation bearing the C3b site could bind beta1H with little effect on the C3b hemolytic activity. Bound beta1H was dissociated by the action of C3bINA and C3bINA-treated C3b bearing cell did not bind beta1H anymore. Cell-bound beta1H was also dissociated by the action of B (or Bb). From these and other results, the following conclusions were obtained. The C3b site-bearing cell could bind beta1H on the C3c region of C3b molecules facilitating the C3bINA action on C3b, and beta1H shared the same binding site with B (or Bb) inhibiting the generation of the alternative pathway convertases competitively.

Beta-Globulins↗
PubMed1977

Conversion of C5 precipitin line in the serum treated with activating substances of complement system.

The hemolytic activity of C5 in the serum treated with zymosan, immune precipitate, or C1s was measured, and the C5 precipitin line on immunoelectrophoresis and the protein concentration of C5 in these serum specimens were also analyzed. A marked decrease in the hemolytic activity of C5 and a complete conversion of C5 precipitin line from beta- to alpha-globulin region were observed in teh serum treated with more than 1 mg/ml of zymosan. The elongation of C5 precipitin line from beta- to alpha-globulin region and the decrease in C5 hemolytic activity were observed in the serum treated with the immune precipitate. But neither change in C5 precipitin line, nor a decrease in hemolytic activity of C5 was observed in C1s treated serum. C5 protein concentrations in these serum preparations were essentially the same as those of control. From these results, it was concluded that the immunoelectrophoretic change of C5 precipitin line might express the grade of the decrease in C5 hemolytic activity in the serum treated with the activating substances of the complement system.

Antigen-Antibody Complex↗
PubMed1977

Interaction of S-sulfonated human IgG with human complement and its components.

S-sulfonated human IgG (S-sIgG) was prepared by treating IgG with sodium sulfite and sodium tetrathionate. The treatment resulted in the selective cleavage of interchain disulfide bonds of the IgG to give S-sulfonate groups. Complement fixing activities of aggregated S-sIgG and the immune complex formed with the S-sIgG antibody were very weak. S-sIgG at a high dose reduced the activity of the first complement component (C1) in normal human serum without any reduction of other complement components activites, but S-alkylated IgG at the same dose did not. Loss of C1 activity was not caused by either S-sulfonated myeloma proteins (IgA and IgE) or urea-treated S-sIgG, in which both inter- and intra-chain disulfide bonds were cleaved. These results suggest that the selective reduction of C1 by S-sIgG is due to a conformational change of the immunoglobulin.

Complement Fixation Tests↗
PubMed1977

C3 and C5-cleaving properdin enzymes formed on zymosan incubated with human serum: the decay and the regeneration of the enzymes.

Incubation os zymosan (Z) with normal human serum led to the formation of ZXhu, which had the abilities to cleave C3 and C5. Kinetic studies on ZXhu formation revealed that the amount of inactivated C5 by ZXhu, when expressed in site-forming unit (SFU), was much greater than that of inactivated C3. When ZXhu having limited C3 and C5-cleaving was incubated at 37 degrees C it decayed with a first order reaction completely in 120 min. At any stage of decay of ZXhu, the activities could be restored by the addition of both B and D, but not by the addition of B or D alone. Not D but B could be bound to the completely decayed ZXhu, and activation of bound B by D led to the regeneration of ZXhu.

Beta-Globulins↗
PubMed1977

The cold activation of the classical complement pathway: The cause of the differences between plasma and serum complement in liver cirrhosis.

The mechanism responsible for making the differences between plasma and serum complement (CH50) was studied on eight patients with hepatitis-B(s) antigen negative alcoholic liver cirrhosis. CH50 and C4 activities of the sera of all patients were equal to those of the corresponding EDTA-plasma, when sera wre separated after clotting the blood at 37 degrees C. CH50 and C4 activities of the sera, prepared at 21 degrees C or 4 degrees C, from four of eight patients were very low. When serum from one of these four patients was added to normal human serum, C4 activity of the serum mixture markedly decreased at 4 degrees C but not at 37 degrees C. The inactivation of C4 was prevented by adding EDTA or heparin to the serum mixture. These results indicated that very low complement in the sera, prepared at 21 degrees C or 4 degrees C, of the four cases were due to the cold activation of the classical complement pathway.

Cold Temperature↗
PubMed1976

The inactivator of the first component of human complement (C1INA): the complex formation with plasmin.

The reaction of C1INA with plasmin was followed by the stoichiometric inactivation of both activities. On acrylamide gel electrophoresis, the reaction mixture revealed 3 new substances. One formed a precipitin band against anti-C1INA and its molecular weight was 103,000 daltons, 14,000 less than that of C1INA, indicating that a portion of C1INA was partially cleaved by the proteolytic activity of plasmin. Each of the other two substances formed precipitin bands against anti-C1INA as well as against anti-plasminogen. Molecular weights of these two substances were 200,000 and 179,000 daltons, whereas the molecular weights of C1INA and plasmin are 117,000 and 82,000 daltons, respectively. From these results, it was concluded that a portion of C1INA in the reaction mixture was partially cleaved by plasmin, and the partially cleaved C1INA as well as the native C1INA form 1:1 molecular complexes with plasmin, leading to inactivation of these activities.

Animals↗
PubMed1976

Inactivator of the first component of human complement (C1INA). Enhancement of C1INA activity against C1s by acidic mucopolysaccharides.

Acidic mucopolysaccharides enhanced C1INA activity against C1s. The presence of heparin in the reaction mixture of C1INA and C1s markedly enhanced the inactivation of C1s by potentiating C1INA activity. Treatment of serum with C1s resulted in the inactivation of C4 hemolytic activity, but this inactivation of C4 by C1s was prevented by the presence of heparin presumably due to the enhancement of C1INA activity normally present in serum. The other acidic mucopolysaccharides, chondroitin sulfates A, B and C, were also effective on potentiating C1INA activity against C1s, but they were less active than heparin. The enhancement of C1INA activity by heparin was not observed in the reaction between C1INA and plasmin.

Chondroitin Sulfates↗
PubMed1976

Differences between plasma and serum complement in patients with chronic liver disease.

Of sixty patients with chronic liver disease, eight with cirrhosis or chronic hepatitis had very low serum CH50 but normal plasma CH50. The complement component profiles of these sera revealed markedly decreased C4 and C2 activities and normal C3T (C3-C9) activities. From these results, it is suggested that the early acting complement components had been non-specifically activated during blood coagulation in these patients. No difference between plasma and serum CH50 was found in patients with hepatitis B(s) antigen.

Adult↗
PubMed1976

Activation of the alternative complement pathway by water-insoluble glucans of streptococcus mutans: the relation between their chemical structures and activating potencies.

Water insoluble, sticky glucan was synthesized by reacting glucosyltransferase obtained from the sulture filtrate of cariogenic Streptococcus mutans OMZ 176 on sucrose. This glucan (OMZ 176 glucan), that consisted of the backbone chains of consecutive alpha-1, 3 glucosidic linkages (65%) and the side chain of alpha-1, 6 glucosidic bonds (35%), showed an ability to activate the alternative pathway of the complment system in human serum. Water soluble glucans synthesized from the reaction of glycosyltransferases of S. mutans strain AHT, FA-I, and Ingbritt with sucrose, that have a high content of alpha-1,6 and a low content of alpha-1, 3 glucosidic linkages, were less effective to activate the complement system. Sephadex (G-25) and Dextran (T-2,000 and T-40), that consisted exclusively of alpha-1, 6 glucosidic linkages, did not significantly activate the complement system. Controlled Smith degradation products of OMZ 176 glucan, composed of the alpha-1, 3 linked glucose backbone chain alone, lost its activity. From these results it was concluded that both backbone chain of alpha-1, 3 glucose units and branched alpha-1, 6 glucose units were essential for the OMZ 176 glucan to activate the alternative pathway of the human complement system.

Aspergillus niger↗