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Biomedical subjects

S Ruddy

Publications and source records attributed to S Ruddy.

At least 19 recordsLinked to original sources
PubMed1992

A testis-expressed Zn finger gene (ZNF76) in human 6p21.3 centromeric to the MHC is closely linked to the human homolog of the t-complex gene tcp-11.

A novel testis-expressed Zn finger gene (ZNF76) was identified by screening cDNA libraries with cosmids derived from 6p21. ZNF76 is a member of the GLI-Krüppel family of DNA binding proteins. It is conserved in mouse where transcription in testis is initiated at Day 20 after birth. The mouse tcp-11 gene is located in the distal inversion of the t-complex and is developmentally regulated in the same manner as ZNF76. The human homolog of tcp-11 was isolated to allow a precise chromosomal localization. By using a combination of somatic cell hybrids, radiation hybrids, metaphase and interphase fluorescent in situ hybridization, and pulsed-field gel electrophoresis, we mapped the two genes to the 6p21.2 to 6p21.3 region and linked them to each other within 300 kb of DNA, approximately 2 Mb centromeric to the major histocompatibility complex.

Amino Acid Sequence↗
PubMed1991

Association of activated properdin with complexes of properdin with C3.

An ELISA using antibody to properdin (P), followed by antibody to C3 to detect complexes of P with C3 (P-C3), detected low levels of P-C3 complexes in human serum and plasma samples. Incubating serum for 1 h at 37 degrees C increased the amount of P-C3 and diminished factor B hemolytic activity without altering total alternative pathway activity or C3 activity in serum. When P and C3 in incubated serum were analyzed by size exclusion HPLC, complexes of P-C3 were detected at retention times corresponding to molecular mass measuring in excess of 2 x 10(6) Da. Activation of serum with zymosan or cobra venom factor greatly increased the level of P-C3 and decreased alternative pathway hemolytic activity. Chromatography of proteins eluted from serum-treated zymosan detected a peak of P at 9.7 x 10(5) Da and a peak of P-C3 at 1.5 x 10(6) Da. Functional assays for activated properdin also revealed a peak of activity at 1.5 x 10(6) Da, congruent with the peak of P-C3. Native properdin was detected at 3.9 x 10(5) Da. When native properdin was added to properdin-depleted serum and incubated for 1 h at 37 degrees C, activated properdin was detected at the same position in the chromatograph as were P-C3 complexes. We conclude that incubation of serum at 37 degrees C produces complexes of P with C3, that exposure of serum to alternative pathway activators increases the amount of P-C3, and that generation of P-C3 complexes is associated with the presence of activated P.

Chromatography, Gel↗
PubMed1991

Synovial fluid levels of complement SC5b-9 and fragment Bb are elevated in patients with rheumatoid arthritis.

To determine whether complement turnover in synovial fluids of patients with rheumatoid arthritis (RA) reflects activation by the classical or alternative pathway, we used novel immunoassays to measure products of complement activation (the membrane attack complex SC5b-9 and the cleavage fragments Bb and C4d). Mean synovial fluid levels of SC5b-9 were more than 8 times higher in RA than in crystal-induced arthritis (gout and pseudogout) and over 16 times higher than in degenerative joint disease (DJD). Similarly, Bb levels were more than 3 times higher in RA synovial fluids than in crystal-induced arthritis and over 7 times higher than in DJD. Levels of C4d did not differ among the groups. SC5b-9 levels correlated with synovial fluid C3 anaphylatoxin (C3a), Bb, and C4d levels (r = 0.81, 0.62, and 0.51, respectively). In patients with RA, synovial fluid SC5b-9 levels correlated with C3a and Bb (r = 0.6 and 0.56, respectively) but not with C4d. Therefore, novel assays for complement activation indicate that both classical and alternative pathways are involved in complement turnover and that the alternative pathway contributes more to complement activation in RA than in DJD or crystal-induced arthritis.

Arthritis, Rheumatoid↗
PubMed1991

Isolation and characterisation of a testis-expressed developmentally regulated gene from the distal inversion of the mouse t-complex.

We differentially screened a pool of mouse testis clones in order to identify genes important in germ cell development. One of the isolated clones was found to be expressed only in the male germ line where it is first detected at around the pachytene spermatocyte stage. This gene maps to a subregion of the t-complex in the distal inversion near, but not within, the tw18 and the th20 deletions. A comparison of the t and wild forms of the gene reveals a high degree of sequence conservation. This gene is associated with a CpG-rich island at its 5' end. It encodes a novel protein with extensive alpha-helical structure indicative of coiled-coil interactions.

Amino Acid Sequence↗
PubMed1991

Reversal of the vasospastic component of lupus vasculopathy by infusion of prostaglandin E1.

The responses of 3 patients with systemic lupus erythematosus (SLE) and progressive digital ischemia to intravenous prostaglandin E1 (PGE1) were studied prospectively in an open 3-day trial. All patients were unresponsive to corticosteroids, one had vasculitis proven by biopsy. Digital ischemia diminished in all 3 patients. In one patient, angiograms documented reappearance of a previously obstructed deep palmar arch. Vasospasm plays a role in the outcome of SLE vasculitis even in the absence of Raynaud's phenomenon. As suggested by animal models of necrotizing and leukocytoclastic vasculitis, and by case reports, intravenous PGE1 may be a relatively nontoxic, adjunctive treatment for vasculitis.

Adult↗
PubMed1979

Demonstration of beta 1H globulin together with C3 in the dermal-epidermal junction of patients with systemic lupus erythematosus.

Skin lesions and clinically normal skin from 10 patients with systemic lupus erythematosus (SLE) were examined by immunofluorescence for the presence of C3 and its control protein, beta 1H globulin. beta 1Hwas always found in association with deposited C3; in the instance where C3 deposits were not found beta 1H was also not found. Granular deposits of C3 and beta 1H were found in the dermal-epidermal junction (DEJ) in all of the 5 nonlesional skins studied. In the lesional skin, C3 was found in 4 of 5; in 2 of these 4, beta 1H was also found. As previously demonstrated for in vitro systems, beta 1H also binds in vivo to fragments of C3, presumably C3b, generated during activation of the complement system.

Adolescent↗
PubMed1979

Deposition of beta 1H globulin in kidneys of patients with immune renal disease.

Renal biopsies from patients with a variety of immune type renal diseases were examined by immunofluorescence for the presence of C3 and its control protein, beta 1H globulin. Deposits of beta 1H were found in every instance (21 of 21 biopsies) in which C3 deposits were observed, irrespective of the underlying disease resulting in the C3 deposits, including lupus nephritis, acute poststreptococcal glomerulonephritis, idiopathic membranous glomerulonephritis, and Goodpasture's syndrome. In no instance was beta 1H found independently of C3. As previously shown in in vitro systems, beta 1H also binds to C3, presumably C3b, during activation of the complement system in immunologically induced renal disease.

Anti-Glomerular Basement Membrane Disease↗
PubMed1979

Lyme arthritis: correlation of serum and cryoglobulin IgM with activity, and serum IgG with remission.

Forty-eight patients with erythema chronicum migrans (ECM) were studied prospectively for 6 to 18 months. Twenty-six patients had no later symptoms, but 22 subsequently developed Lyme arthritis and 9 of them also experienced neurologic abnormalities. Eighty-seven percent of patients with active ECM followed by subsequent involvement had cryoglobulins containing IgM compared to only 13% of those with active ECM and no later symptoms. The former group also had significantly lower IgG, C3 and C4 levels. Sixty-seven percent of patients still had serum cryoglobulins when neurologic disease was most active, and 45% had them when joint symptoms were most severe, but only 11% continued to have small amounts in remission. The number of patients who continued to have serum cryoglobulins with recurrent attacks of arthritis decreased with time. In contrast, patients always had cryoglobulins in joint fluid, a finding Lyme arthritis shares with rheumatoid arthritis. The cryoprecipitates from 2 of 10 patients contained particles with internal structure, but their viral nature is problematic. All components of antisera obtained from goats and rabbits immunized with cryoglobulins were absorbed by normal human sera. The amount of IgM in cryoglobulins correlated directly with serum IgM, which generally rose during exacerbations and fell during remissions; serum IgG and IgA moved conversely. Thus, IgM was an important correlate of clinical disease activity and IgG or remission.

Adolescent↗
PubMed1979

Demonstration of the complement regulating protein, beta 1H, in skin biopsies from patients with bullous pemphigoid.

beta 1H-globulin is a recently characterized plasma protein which regulates the biologic activities of the major fragment of the third complement component, C3b. The major function of this protein is to act as a co-factor for C3b Inactivator (C3bINA) in the cleavage of C3b to an intermediate molecule, C3b', consisting of an intact beta-chain covalently bound by disulfide bridges to 2 alpha-chain fragments of 40,000 and 67,000 daltons. Final cleavage of C3b' to the C3c and C3d fragments requires an additional protease such as plasmin or elastase. Additionally, beta 1H interferes with the activity of the alternative pathway convertases, C3bBb and C3bBbP, by displacing or competing with the binding of factor B. In this study, perilesional skin biopsies from 10 patients with active bullous pemphigoid were examined for the presence of beta 1H at the dermal-epidermal junction by immunofluorescent methods. The protein was found in 8 of 9 biopsies in which C3 also was deposited. In a single case where C3 was not found, beta 1H was not seen. These findings suggest that beta 1H plays a role in the in vivo control of C3b and provides additional evidence for the participation of the complement system in the pathogenesis of bullous pemphigoid.

Aged↗
PubMed1979

Circulating immune complexes in Lyme arthritis. Detection by the 125I-C1q binding, C1q solid phase, and Raji cell assays.

We have found immunoglobulin (Ig) G-containing material consistent with immune complexes in the sera of patients with Lyme arthritis. It was detected in 29 of 55 sera (55%) from 31 patients by at least one of three assays: (125)I-C1q binding, C1q solid phase, or Raji cell. The presence of reactive material correlated with clinical aspects of disease activity; it was found early in the illness, was most prominent in sera from the sickest patients, was infrequent during remissions, and often fluctuated in parallel with changes in clinical status. The results in the two C1q assays showed a strong positive correlation (P<0.001). They were each elevated in 45% of the sera and were usually concordant (85%). In contrast, the Raji cell assay was less frequently positive and often discordant with the C1q assays. In sucrose density gradients, putative circulating immune complexes sedimented near 19S; they, too, were detected best by the two assays based on C1q binding. An additional 7S component was found in some sera by the (125)I-C1q binding assay. Serum complement was often above the range of normal in patients with mild disease and normal in patients with severe disease but did not correlate significantly with levels of circulating immune complexes. IgM and IgG rheumatoid factors were not detectable. These findings support a role for immune complexes in the pathogenesis of Lyme arthritis. Their measurement, by either the (125)I-C1q binding assay or by the C1q solid phase assay, often provides a sensitive index of disease activity. Moreover, the complexes are likely sources of disease-related antigens for further study of this new disorder.

Adolescent↗
PubMed1979

Relative importance of C3b inactivator and beta 1H globulin in the modulation of the properdin amplification loop in systemic lupus erythematosus.

Serum concentrations of C4, C3, factor B (B), properdin (P), C3b inactivator (C3bINA) and beta 1H globulin have been measured by radial immunodiffusion in sixty-two samples from thirteen patients with systemic lupus erythematosus (SLE). Significant reductions in the mean serum concentrations of C4 (classical pathway) B and P (alternative pathway) and C3 were found. In addition, the mean level of the control protein beta 1H, but not C3bINA, was reduced. Sera from thirteen patients taking during disease exacerbation (low C3) showed significantly lower levels of both C3bINA and beta 1H than sera taken from the same thirteen patients during disease remission (high C3). Serum concentrations of C3bINA correlated with B (P less than 0.005) but not C4, C3 or P, whereas levels of beta 1H correlated with C4 (P less than 0.01), B (P less than 0.005) and properdin (P less than 0.01). Serial measurements of the serum concentrations of C3bINA and beta 1H showed that levels of these protein fell during exacerbation, and such falls were more closely associated with diseases in the serum levels of the alternative pathways proteins than C4. It is concluded from these observations that serum concentrations of the control proteins C3bINA and beta 1H, especially the latter, control the extent of turnover of the alternative pathway in SLE. Metabolic studies are required to determine the causes of the decreased serum concentrations of these control proteins.

Complement Activation↗
PubMed1979

Modulation of the properdin amplification loop in membranoproliferative and other forms of glomerulonephritis.

The mean serum concentrations of C3b inactivator (C3bINA) and beta1H globulin were measured in eighty-six sera (thirty-five membranoproliferative, thirteen membranous, thirty-one focal and seven minimal change) taken from seventy-five patients with histologically diagnosed glomerulonephritis. In none of the four groups of sera did the mean concentrations of both these proteins differ significantly from the mean levels in a group of fifty normal sera. However, in the membranoproliferative group, the mean level of C3bINA, but not beta1H, was significantly lower in the nephritic factor positive than in the nephritic factor negative group. When the eighty-six sera were considered together, serum concentrations of C3bINA and beta1H correlated with levels of C3, factor B, properdin and C4. When the membranoproliferative group was considered separately, C3bINA levels correlated with levels of C3, factor B, properdin and C4 and beta1H correlated with C3 and factor B, but not properdin or C4 in the nephritic factor negative group, but no such correlations were observed in the nephritic factor positive group. The significance of these findings is discussed in the light of current thoughts on the mechanisms of modulation of the alternative pathway.

Beta-Globulins↗
PubMed1979

Complement receptor binding of C3b-coated cells treated with C3b inactivator, beta 1H globulin and trypsin.

Treatment of 125I-C3b bound to EAC1423b with C3b inactivator (C3bINA) and beta 1H globulin (beta 1H) cleaved the alpha-chain of C3b into 65,000- and 42,000-dalton fragments, both of which remained disulfide-bonded to the intact beta-chain (C3bi). Subsequent treatment with trypsin (0.1 microgram/ml) released 125I into the supernatant and yielded cells coated with a 33,000-dalton fragment of alpha-chain, presumably C3d. These results are in agreement with those obtained by others using fluid phase C3b. C3b-coated cells (EAC1423b) adhered to complement (C) receptors on human erythrocytes, glomeruli, and monocytes. C3bi-coated cells adhered to the receptors on glomeruli and monocytes, but not to those on human erythrocytes. C3d-coated cells adhered only to the monocyte receptors. The findings suggest that the glomerular C receptor recognizes portions of the C3 molecule different from those recognized by either the erythrocyte or monocyte receptors.

Animals↗
PubMed1978

Interaction of beta1H globulin with cell-bound C3b: quantitative analysis of binding and influence of alternative pathway components on binding.

Purified beta1H globulin (beta1H) was shown to bind to C3b coated cells by both immunofluorescent and radioactive tracer techniques. With EAC43, the amount of beta1H bound was directly proportional to the amount of C3 used to prepare the cells; EA, EAC14 and EAC14oxy2 bound very small amounts of beta1H. The C3b binding site on beta1H was labile in that not all of the purified 125I-beta1H was capable of binding to C3b, even when an excess of cell-bound C3b was present. Scatchard analysis of binding of beta1H to C3b-coated cells indicated an equilibrium constant of 10(9) L/M. Deviations from linearity were regularly found on Scatchard analyses. This was consistent with the hypothesis that the beta1H binding sites exhibit negative cooperativity in that as more sites become occupied, it becomes more difficult to fill the remaining sites. The stoichiometry of the reaction between C3b and beta1H was examined using EAC14oxy23 prepared with 131I-C3 and beta1H labeled with 125I. Between 0.5--0.8 beta1H molecules were bound per C3b molecule. Other alternative pathway components influenced the binding of 125I-beta1H to cell bound C3b. Both C3b and native C3 inhibited binding of labeled beta1H at an efficiency approximately 1/1,000 that of unlabeled beta1H. Factor B inhibited binding with 1/280 the efficiency of unlabeled beta1H. Properdin caused a dose-dependent increase in the binding of beta1H; this enhancement was abrogated if B was also present in the reaction mixture. Scatchard analysis indicated that the enhancement of beta1H binding by P resulted in an increased number of available binding sites rather than an increase in the affinity of binding.

Animals↗
PubMed1977

Production of the second component of complement by human monocytes: stimulation by antigen-activated lymphocytes or lymphokines.

Human peripheral blood mononuclear cells cultured in the presence of antigen produced hemolytically active second complement component earlier and in larger amounts than did control cultures of the same cells without antigen. The increased amount of C2 in culture supernates came primarily from the adherent cell population and was due to increased synthesis as demonstrated by inhibition with 10(-4) M cycloheximide. Purified adherent monocytes produced more C2 when exposed to lymphokine-rich supernates from antigen-stimulated lymphocytes than when exposed to control supernates from unstimulated lymphocyte cultures. The increased synthesis of C2, which appeared to be mediated by a lymphokine, was partially inhibited specifically by 0.025 M alpha-L(-) fucose, a sugar which has previously been shown in inhibit the response of macrophages to migration inhibitory factor.

Antigens↗
PubMed1977

Congenital heart block in newborns of mothers with connective tissue disease.

Of 22 children with congenital complete heart block (CCHB) available for study, 14 (63.6%) were born to 11 mothers with clinical or laboratory evidence of connective tissue disease, primarily lupus erythematosus (LE). Seven mothers had both clinical and laboratory evidence of disease while four had only positive laboratory studies including fluorescent antinuclear antibody, rheumatoid factor, and depressed complement levels. In adults with systemic LE, pathologic changes in the collagen surrounding the conduction system have led to the fibrosis and death from heart block. Antinuclear antibodies of the IgG class cross the placental barrier and newborn infants have been reported with transient skin lesions of lupus. Placental transmission of such antibodies may affect the fetal cardiac conduction system, surrounding collagen, and myocardium, leading in some cases to CCHB. This is probably one important etiologic factor in CCHB even though the mother is asymptomatic during her pregnancy.

Antibodies, Antinuclear↗