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Biomedical subjects

B H Petersen

Publications and source records attributed to B H Petersen.

At least 37 records · Page 2Linked to original sources

Two types of dysfunctional eighth component of complement (C8) molecules in C8 deficiency in man. Reconstitution of normal C8 from the mixture of two abnormal C8 molecules.

Restoration of hemolytic activity was examined in sera from seven unrelated eighth component of complement (C8)-deficient subjects. The sera fell into two groups, depending on whether hemolytic activity was restored by the addition of the beta-chain (group 1) or the alpha-gamma-subunit (group 2) purified from normal human C8. Antigenic analysis of these sera by double-immunodiffusion using anti-human C8 confirmed previous findings of a dysfunctional C8 in the four sera of group 1 and established the presence of a different dysfunctional C8 in one of the sera of group 2 when tested at a high concentration. Further characterization of the dysfunctional C8 molecules in the two sera by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that group 1 sera were missing the beta-subunit and group 2 sera were missing the alpha-gamma-subunit of the C8 molecule. Sera from either of these two groups alone did not produce hemolysis in hemolytic plates containing sheep erythrocytes coated with antibody and complement components up to C7 (EAC1-7) and C9. When sera from the two groups were added to adjacent wells in the hemolytic plates, a zone of hemolysis developed between the wells. The contribution of C8 alpha-gamma from the sera of group 1 and of C8 beta from those of group 2 to the lysis of EAC1-7 in the presence of C9 was confirmed by the inhibitory effect of specific antibodies against the two C8 subunits. In experiments in which hemolytic activity was reconstituted by mixing sera from group 1 with sera from group 2, the serum source of C8 beta (group 2) was the limiting reagent. The dysfunctional C8 molecule in this serum was able to bind to EAC1-7. Chromatographic analysis demonstrated that the generation of hemolytic activity in the mixture of the two sera resulted from the reconstitution of the C8 molecule rather than the sequential action of the two C8 subunits.

Antibody Formation↗

Genetic polymorphism in C8 beta-chains. Evidence for two unlinked genetic loci for the eighth component of human complement (C8).

Genetic polymorphism in the beta-subunit of the eighth component of human complement, C8, was defined by isoelectric focusing of serum in polyacrylamide gel in the presence of urea and development of specific patterns of hemolysis in an overlay gel containing antibody-sensitized erythrocytes and C8 beta-chain-deficient serum. Bands of hemolysis induced by serum from unrelated Caucasians suggested autosomal codominant inheritance of three structural alleles at a single locus, C82: C82 degrees A (acidic), C82 degrees B (basic), and C82 degrees A1 (very acidic) with frequencies of 0.952, 0.044, and 0.004, as well as the probable null allele C82 degrees Q0. The distribution of phenotypes agreed with the Hardy-Weinberg equilibrium. The previously described genetic polymorphism in human C8 defined with the use of "complete" C8 (C8 alpha-gamma-chain)-deficient serum was distinct from and independent of the inherited structural variation at C82. Therefore, the locus for C8 alpha-gamma-chains has been redesignated C81, and has the alleles C81 degrees A, C81 degrees A1, and C81 Q0. Linkage studies failed to show close linkage between the two loci for C8, C81, and C82, and between C82 and the major histocompatibility complex or C6.

Alleles↗

Cold urticaria associated with infectious mononucleosis.

We have evaluated two patients with cold urticaria associated with infectious mononucleosis and reviewed three case reports with this syndrome. The cold sensitivity ranged from urticaria to anaphylaxis and one patient had additional cold-related cutaneous manifestations. The duration of cold urticaria was transient and paralleled the clinical course of infectious mononucleosis. Analysis of these five cases revealed no correlation of cold urticaria with known cold-activated factors that often occur in this viral infection.

Adolescent↗

Immunological responsiveness of guinea pigs to antibiotics diffusing from bone cement.

The sustained release of antibiotics from bone cement provides an opportunity for the induction of hypersensitivity. We evaluated the cellular and humoral immune responsiveness of guinea pigs to antibiotics diffusing from bone cement. We were unable to detect the presence of antibodies or skin hypersensitivity to any of the antibiotics tested.

Animals↗

Complement consumption gonococcal peptidoglycan.

Purified peptidoglycan (PG) obtained from Neisseria gonorrhoeae was tested for the ability to consume complement in normal human sera. Sonicated PG (S-PG), a heterogeneous mixture of soluble fragments (molecular weight, greater than 10(6)), as well as intact (insoluble) PG, reduced the level of whole hemolytic complement in a pool of four human sera. The minimal concentration of S-PG required for this activity was approximately 500 micrograms of S-PG per ml of serum. Complete lysozyme digestion of S-PG, yielding PG fragments of less than 10(4) molecular weight, eliminated complement-consuming activity. S-PG-mediated complement consumption resulted in depletion of the individual complement components C4 and C3. Consumption of complement did not occur when C4-deficient human serum or normal human sera treated with Mg2+-(ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid to specifically impair classical complement pathway activity were used. The addition of rabbit anti-PG antibody greatly enhanced gonococcal PG-mediated complement consumption. Together, the data suggested that gonococcal PG-mediated complement consumption occurred via the classical complement pathway, was dependent on the presence of anti-PG antibody, and required glycosidically linked polymers of PG. Individual human sera varied widely in the extent of gonococcal PG-mediated reduction of complement levels, presumably a reflection of either different amounts of natural antibody to gonococcal PG, different levels of human PG hydrolase(s) capable of degrading PG to inactive fragments, or both.

Antibodies, Bacterial↗

Human seminal plasma inhibition of antibody complement-mediated killing and opsonization of Neisseria gonorrhoeae and other gram-negative organisms.

Seminal plasma diluted 1:5-1:1,000 gave marked inhibition of serum antibody complement-mediated bactericidal and opsonic effects against Neisseria gonorrhoeae and other gram-negative organisms. Serum that was bactericidal at a dilution of 1:5,120 was not bactericidal at a dilution of 1:10 when seminal plasma was added. Bactericidal action of immune human or rabbit sera, or purified immunoglobulin (Ig)G or IgM plus complement for six strains of N. gonorrhoeae, serogroups A, B, C, and Y of Neisseria meningitidis, Escherichia coli and other gram-negative rods was inhibited by seminal plasma. Using C8- or C7-deficient sera as antibody and complement sources, opsonization, phagocytosis, and killing of N. gonorrhoeae and E. coli 014-K7 were inhibited by seminal plasma. Opsonization, phagocytosis, and killing of Staphylococcus aureus 502A was not inhibited. For the gram-negative organisms, the early phase of the opsonization process, probably complement activation, appeared to be inhibited rather than the ingestion or polymorphonuclear leukocyte killing steps; addition of seminal plasma yielded a significant reduction in the percentage of polymorphonuclear cells with associated bacteria. Seminal plasma did not prevent attachment of IgG, IgM, or IgA antibodies to gonococci. It reduced serum hemolytic whole complement activity by 25%. The seminal plasma inhibitor was of low molecular weight and was stable at 56 degrees C for 30 min, but inhibitory activity was lost after heating to 100 degrees C for 10 min. It is likely that the inhibitory factor(s) is a low-molecular weight protease or protease inhibitor. Seminal plasma probably has an important role in inhibition of complement and antibody functions in the genital tract. It may enhance pathogenesis of agents of sexually transmitted diseases.

Antibodies, Bacterial↗

Suppression of in vitro antibody response of human peripheral blood lymphocytes by a heat-labile factor in normal human serum.

When fresh autologous serum was added to normal human peripheral blood lymphocytes (PBL), it suppressed greater than 90% of the in vitro anti-SRBC response of these cells. Heating the serum for 30 min at 56 degrees C reversed this suppression, Serum from a patient with rheumatoid arthritis and circulating immune complexes had no suppressive effect on the anti-SRBC response of normal human PBL, but serum from patients having the same disease, without circulating immune complexes, did suppress over 90% of the plaque-forming cell response. Serum from an agammaglobulinaemic patient was also suppressive. Addition of serum from patients with congenital deficiencies of C2, C3, C5 and C8 also has a suppressive effect. Absorption of normal serum with immune complexes markedly decreased levels of C1 and C4, and also reversed the suppressive effect of this serum. These data suggest that a heat-labile factor in normal human serum which can be absorbed by immune complexes suppresses the antibody response to a T-dependent antigen. Other immune suppressors found in normal human serum are heat-stable or do not suppress in the presence of normal serum proteins. Thus the suppressive protein described in these studies may be unique. It is possible that either C1 or C4 or both may play a role in the suppression noted here.

Agammaglobulinemia↗

Immunofluorescence findings in rapid whitening of scalp hair.

Rapid whitening of scalp hair developed during a three-month period along with a diffuse, subtotal alopecia in a patient. Immunofluorescence microscopy of biopsy material showed prominent deposits of IgG and IgM in a granular pattern in the epithelium of the lower portions of hair follicles. Some return of the color and amount of scalp hair occurred within a year, but occasional bouts of hair loss continued to occur. It is theorized that the rapid graying was caused by a selective loss of pigmented hair, which was perhaps caused by an immunologic mechanism. Some of the findings suggest that the cause of this patient's loss of hair color may be different from those of patients who have been previously described as having rapid whitening of scalp hair because of alopecia areata or vitiligo.

Depression↗

Protein Malnutrition and complement activity in guinea pigs, germ-free and conventional rats.

Malnutrition produces a pronounced effect on the complement system of man and animals. There is little information, however, to indicate whether individual complement components are affected at different stages of age. In the following studies, we have demonstrated that in guinea pigs and in both conventional and germ-free rats, protein malnutrition adversely affects the complement system. The levels of complement components C2 and C3 are suppressed by protein malnutrition at an early stage while C4 and C8 are less affected by malnutrition. Experiments in germ-free animals demonstrated that decreased complement component levels can be directly associated with decreased synthesis and/or secretion of components. In conventional animals, further reductions in complement levels could occur as a result of infection associated with malnutrition.

Animals↗

Human seminal plasma inhibition of complement.

Recent studies have shown that human seminal plasma contains chemically and biologically distinct factors which inhibit lymphocyte functions and the serum bactericidal and opsonic activities associated with the killing of gram-negative organisms. Because of the direct association between complement action and serum bactericidal and opsonic activities, inhibition of complement may be one of the possible mechanisms of action of seminal plasma immunoinhibitory factors. Complement hemolytic activity was measured for C3 and C4 in serum Neisseria gonorrhoeae and Escherichia coli bactericidal reaction mixtures with and without addition of seminal plasma. In the presence of seminal plasma, where there was no bactericidal action, C3 and titers were reduced to approximately 50% of the titers in the reactions with complement donor serum. The C3 titers were lower than in the reaction mixtures with immune serum and complement donor serum, where N. gonorrhoeae bactericidal activity occurred. Individual human seminal plasma specimens depressed CH50 activity of pooled normal human sera up to 50% of normal levels. There were no differences in inhibition by seminal plasma specimens from normal or vasectomized men. Treatment with seminal plasma depressed the functional activity of complement components C1 and C3 by more than 50%. Seminal plasma also inhibited alternate pathway activity. Cleavage of factor B was demonstrated. The seminal plasma factor which inhibited complement was of low molecular weight. DPF blocked the seminal plasma complement-inhibitory factor. However, amidolytic activity for serine protease substrates could not be demonstrated. It is likely that the seminal plasma complement inhibitor is a protease inhibitor acting singly or in combination.

Absorption↗

Genetic control of the eighth component of complement.

Using isoelectric focusing in polyacrylamide gel and a hemolytic assay for development of patterns, extensive, structural polymorphism in human C8 has been delineated. Two alleles, C8A and C8B, have been identified in orientals, with gene frequencies of 0.655 and 0.345. In blacks, what appears to be a third common allele was found, so that frequencies were 0.692, 0.259, and 0.049 for C8A, C8B, and C8A1. In whites, C8A1 was rare with a frequency of 0.003, and frequencies for C8A and C8B were 0.649 and 0.349. Inheritance was autosomal codominant in family studies and the distribution of types in random unrelated populations fit the Hardy-Weinberg equilibrium in all groups. C8 allotypes have been determined for two previously studied families, each with a homozygous C8-deficient propositus. This study suggests that C8 deficiency is a silent or null allele of the C8 structural locus, and that half normal levels of C8 cannot be used as a single criterion for the establishment of heterozygous C8 deficiency. C8 allotypes, as well as 18 other autosomal markers, were also determined for 24 families. The C8 structural locus is not closely linked to these markers, including the human histocompatibility loci complex.

Alleles↗

Neisseria meningitidis and Neisseria gonorrhoeae bacteremia associated with C6, C7, or C8 deficiency.

We summarize data from 24 previously described or newly diagnosed cases of homozygous deficiency of the sixth, seventh, or eighth components of complement. Thirteen of 24 patients had at least one episode, and usually two or more episodes of Neisseria meningitidis or Neisseria gonorrhoeae bacteremia, or both. Deficiency of C6, C7, or C8 is a meaningful risk factor for repeated neisserial bacteremia; conversely, hemolytic complement studies are indicated in patients who develop recurrent neisserial infections. When a person with C6, C7, or C8 deficiency is identified, family members should also be studied.

Adolescent↗

Serum bactericidal action and activation of the classic and alternate complement pathways by Neisseria gonorrhoeae.

In order to more fully understand the host defense mechanisms against gonococcal infections, we decided to define the role of the classic and alternate complement pathways in gonococcal BA. Sera and infecting isolates were collected from several patients with genital and disseminated gonococcal infections. Sera from two never-infected subjects and a hypogammaglobulinemic patient were also collected. Sera from patients with genital gonorrhea and never-infected controls demonstrated marked BA for gonococci after 30 min incubation. Chelation of these sera with MgEGTA delayed the expression of BA. Consumption of C3, but not C4, was observed in chelated samples. BA could not be demonstrated in any of the sera from DGI patients or the patient with hypogammaglobulinemia. Aliquots of fresh and chelated hypogammaglobulinemic serum to which IgM or IgG antigonococcal antibodies were added showed marked BA by 30 and 60 min, respectively. Absorption of chelated serum with a serum-sensitive isolate eliminated the previously observed delayed BA. The findings suggest that gonococcal serum BA is primarily associated with activation of the classic complement pathway. Activation of the alternate pathway also occurs; however, its expression is delayed and appears to be antibody-dependent.

Adult↗

Constant post-irradiation repopulation rates and linear relationship between cellular blood response and number of transplanted bone marrow cells in inbred mice.

Graded doses of syngeneic bone marrow cells were transplanted into lethally irradiated mice. Repopulation curves of peripheral blood granulocytes and platelets were apparently exponential and parallel after doses larger than 5 X 10(5) cells. The blood platelet Td was reduced from 111 h to 53-57 h, and granulocyte Td from 57 to 40 h in transplanted groups. The mean blood cell counts were reproducible enough to be used as a biological assay of the amount of bone marrow cells transplanted. Linear relationship between increment of blood cells up to day 16 and number of bone marrow cells transplanted on day 1 was demonstrated (1,200 granulocytes and 14,300 platelets/mul blood per 10(5) bone marrow cells). The linearity suggested a mean Td less than 22.5 h of proliferating bone marrow cells, and allowed a rough estimation of mouse bone marrow stem cell radiosensitivity (Do 76 rad).

Animals↗

Bactericidal and opsonic activity against Neisseria gonorrhoeae in sera from patients with disseminated gonococcal infection.

Bactericidal and opsonic activities in convalescent-phase sera from patients with disseminated gonococcal infection (DGI) were analyzed with use of the patients' infecting strains and other strains of Neisseria gonorrhoeae. Serum from a patients with C8 deficiency was opsonic for her first DGI isolate grown on solid medium or in chick embryos; with added complement the serum was bactericidal (at a dilution of 1:320). Her serum was not bactericidal for nine other isolates from patients with DGI. Only one of the other patients with DGI had detectable serum bactericidal activity (dilution, 1:2,5) against her own isolate; this patient's serum was also active against one other DGI isolate. Opsonization was detectable only in sera that were potentially bactericidal and could be distinguished from bactericidal activity only with C8-deficient serum. The isolates from patients with DGI were of an auxotype different from that of most other gonococci, and most of the isolates tested were not killed by sera from patients with uncomplicated gonorrhea, even though these wera killed other gonococci. Thus, isolates from patients with DGI appeared to be significantly different from other gonococcal isolates.

Antibodies, Bacterial↗