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Biomedical subjects

R L Rubin

Publications and source records attributed to R L Rubin.

At least 91 records · Page 5Linked to original sources
PubMed1984

Autoallergic reactions induced by procainamide.

Procainamide has a high propensity for the induction of an autoimmune response. The immune response is highly selective and the autoantibodies so induced are directed against nuclear histones. Acetylator phenotypes play an important role in the immune response, with slow acetylators developing antihistone antibodies much sooner than fast acetylators. In the early detection of drug-induced lupus syndromes, the finding of antihistone antibodies in the absence of other types of antinuclear antibodies greatly aids in establishing the diagnosis.

Acetylation↗
PubMed1984

Reevaluation of specificity of Crithidia luciliae kinetoplast as a substrate for detecting antibodies to double-stranded deoxyribonucleic acid.

Until now, the kinetoplast of the hemoflagellate Crithidia luciliae has been believed to be a specific indirect immunofluorescence substrate for detecting antibodies to double-stranded deoxyribonucleic acid (DNA). We have recently identified a patient in whom there was the apparent presence of procainamide-induced antinuclear antibodies at a titer of 1/1,280 on mouse kidney sections. This patient's serum also contained antihistone antibodies at a titer of 1:1,280, on the basis of a mouse kidney section histone reconstitution assay. In addition, results of an enzyme-linked immunosorbent assay (ELISA) using a pure histone preparation were strongly positive. We found that this serum produced C. luciliae fluorescence to a titer of 1:80. After pretreatment of the C. luciliae substrate with hydrochloric acid to remove histones, this serum no longer produced kinetoplast fluorescence. However, this serum again produced kinetoplast fluorescence when assayed on a hydrochloric acid-treated C. luciliae substrate that had been reconstituted with purified histone. The negative kinetoplast reactivity after hydrochloric acid treatment of the C. luciliae substrate suggests that the antibody is reacting with acid-extractable nucleic acids, not necessarily the double-stranded DNA, or the antibody is directed against nuclear proteins such as DNA-histone complexes of deoxyribonucleoprotein. The finding that reactivity reappeared after the histone was reconstituted back to the hydrochloric acid-treated C. luciliae substrate suggests that the primary antibody in this serum is directed against DNA-histone complexes or histone alone. These findings strongly suggest that the kinetoplast of C. luciliae contains antigens other than double-stranded DNA and that is not a specific substrate for the detection of double-stranded DNA antibodies by indirect immunofluorescence.

Adult↗
PubMed1984

Reappraisal of the specificity of the Crithidia luciliae assay for nDNA antibodies: evidence for histone antibody kinetoplast binding.

Five different high-titer histone antibody-containing sera were assayed by the Crithidia luciliae indirect immunofluorescence (CLIF) technic. Three of these sera produced kinetoplast binding at titers of 1/40 to 1/80. The kinetoplast binding activity was abolished by HCl acid pretreatment of the Crithidia substrate, suggesting that the kinetoplast binding activity was not due to antibodies against native DNA (nDNA). Histone antibodies were purified from two of the three positive sera by affinity chromatography utilizing purified preparations of histone. Both purified antibody preparations also had kinetoplast-binding activity, confirming that the Crithidia kinetoplast contains histone-like proteins. Therefore, Crithidia luciliae (CL) kinetoplast binding activity does not necessarily indicate the presence of anti-nDNA antibodies. Routinely pretreating the CL substrate with 0.1 N HCl would eliminate the possibility of histone antibody kinetoplast binding in the CLIF assay. Whether such pretreatment would alter the binding of anti-NDNA to the kinetoplast remains to be determined.

Antibodies↗
PubMed1984

Monoclonal anti-histone autoantibodies derived from murine models of lupus.

We characterized three monoclonal antibodies with histone reactivity which were derived from spleen cells obtained from unmanipulated NZB/NZW or MRL/1 mice. By using an enzyme-linked immunosorbent assay, we noted that all three antibodies reacted with chromatin histones as well as with total histones extracted from chromatin. None of the antibodies appeared to require DNA as part of the antigen. One antibody (BWH-1) recognized a determinant present in the nucleosome core H2A-H2B complex but showed little reactivity with any of the individual histones (H1, H2A, H2B, H3, or H4). In contrast, the other two monoclonal antibodies each recognized multiple individual histones in a unique pattern. Antibody MH-1 reacted with H2A, H2B, and H3; antibody MH-2 reacted with H2A, H3, and H4. MH-1 demonstrated cross-reactivity with poly-1-lysine but not poly-1-arginine or protamine sulfate; the opposite pattern of cross-reactivity was observed with MH-2. The antigenic determinants recognized by MH-2 were all trypsin-sensitive, suggesting that these determinants were present on the N-terminal regions of the respective individual histones. These studies revealed markedly different specificities of anti-histone monoclonal antibodies derived from murine models of systemic lupus erythematosus. These and other similarly derived antibodies may provide interesting tools to understand the specificity and biologic importance of anti-histone autoantibodies in different diseases.

Animals↗
PubMed1984

Anti-native DNA antibodies from autoimmune sera also bind to DNA in mitochondria.

Sera from 20 patients with systemic lupus erythematosus (SLE), selected for elevated titers of antibody to native DNA (nDNA), were examined by indirect immunofluorescence (IF) on tissue culture Hep-2 and rabbit kidney cells. Twelve sera showed a particulate cytoplasmic staining, in addition to nuclear IF. Double IF staining by using a mouse monoclonal anti-nDNA and a human serum containing anti-mitochondrial antibody as probes showed that the cytoplasmic structures recognized by these 12 SLE sera were mitochondria. SLE sera showing mitochondrial staining had high anti-nDNA levels, as assessed by ELISA (3.5 +/- 1.9 O.D.), compared with those not showing this staining pattern (0.8 +/- 0.4 O.D.). Mitochondrial staining was abolished by DNase I pretreatment of the substrates. Liquid phase absorption of serum anti-nDNA with S1 nuclease-treated calf thymus DNA or purified mitochondrial DNA also removed staining. These findings demonstrate that anti-nDNA antibodies from patients with SLE bind to DNA in intact mitochondria. Therefore, mitochondrial IF staining on tissue culture cells in the presence of nuclear staining should be interpreted with caution, because the phenomenon could be entirely related to anti-native DNA. These observations might also provide new insights concerning the nature of immunogenic cellular components stimulating anti-DNA production.

Animals↗
PubMed1983

An improved ELISA for anti-native DNA by elimination of interference by anti-histone antibodies.

We evaluated an enzyme-linked immunosorbent assay (ELISA) for antibodies to native DNA (nDNA) in which protamine was used to link DNA to polystyrene. Elevated anti-nDNA was largely restricted to patients with systemic lupus erythematosus (SLE), and within this group good correlation between ELISA and the ammonium sulfate assay was obtained. However, substantial background immunoglobulin binding to protamine coated wells was commonly observed, and it was necessary to subtract this activity from each anti-DNA determination. Many of the SLE sera also contained anti-histone antibodies, and this antibody activity showed significant correlation with the binding to protamine. In contrast, methylated bovine serum albumin (mBSA) did not bind anti-histone antibodies and provided a substrate for coupling nDNA to polystyrene. This modified ELISA allowed the quantitation of antibodies to native DNA without the simultaneous binding of anti-histone antibodies.

Ammonium Sulfate↗
PubMed1983

In vivo and in vitro production of anti-histone antibodies in NZB/NZW mice.

Anti-histone antibodies have been demonstrated in the sera of patients with both idiopathic and drug-induced lupus. We measured anti-histone antibodies in female NZB/NZW (F1) mice, which are considered to be a model of human SLE. Using a sensitive and quantitative enzyme-linked immunosorbent assay (ELISA), we detected minimal serum antibody activity in NZB/NZW mice younger than 4 mo of age and in nonautoimmune mice at all ages tested. Serum anti-histone antibodies progressively increased in NZB/NZW mice from 4 to 8 mo of age and showed an age-related maturation from IgM to IgG. The predominant antibody activity in the older mice was to the individual histones H2B and H3, and the pattern of reactivity to the histone proteins was similar to that seen in human SLE. We also studied the spontaneous in vitro production of anti-histone antibodies using spleen cells from NZB/NZW mice of different ages. Culture supernatants were analyzed for antibody activity by an ELISA with total histones as the antigen. Spleen cells from older NZB/NZW mice, with elevated serum levels, produced 10-fold higher levels of antibody activity compared to age-matched nonautoimmune mice. Antibody production was maximal at 4 days of culture and was inhibited by the addition of puromycin to the culture. Surprisingly, spleen cells from 1 to 3-mo-old NZB/NZW mice, with normal serum levels, also demonstrated significantly elevated production. The antibodies produced by these young mice were mostly IgM, whereas spleen cells from older mice produced mostly IgG anti-histone antibodies. The present results provide the basis for using the anti-histone antibody system to study further the immune abnormalities that allow for autoantibody production.

Aging↗
PubMed1982

A solid-phase radioimmunoassay for anti-histone antibodies in human sera: comparison with an immunofluorescence assay.

A solid-phase assay for anti-histone antibodies is described, in which antibodies bound to calf thymus total histones, specific histone classes, or chromatin were detected by radioactive anti-human IgG, IgA or IgM. The reactivity of human sera from various rheumatic diseases was analyses by this assay and compared with results obtained from an indirect immunofluorescence assay (FANA) previously described. Sera that were positive in the FANA assay were usually positive in the solid-phase assay when total histones were the solid-phase antigen. However, many sera had IgM antibodies to total histones in the solid-phase assay but gave no detectable reaction in the FANA assay. Results from the solid-phase assay, using individual histones and chromatin, showed that the anti-histone antibodies in these sera were predominantly reactive with histones H3-H4 and did not bind well to histones complexed to DNA in the form of chromatin.

Animals↗
PubMed1981

A radial diffusion assay for plasma and serum deoxyribonuclease I.

A simple radial diffusion technique is described for assaying deoxyribonuclease I (DNase I) activity in whole human plasma and serum. Enzymatic activity was calculated from a standard curve constructed from the studies on the hydrolysis of calf thymus DNA by bovine pancreatic DNase of known concentrations. The assay was shown to be specific for nucleases which are active at neutral pH and require magnesium ions for activation. There was no significant difference in DNase I activity in plasma compared with that in serum from normal individuals (P greater than 0.05). The DNase I activity of 35 normal human sera was 26.1 +/- 9.2 ng/ml and ranged from 10.8-48.5 ng/ml. This technique may prove useful for the evaluation of DNase I activity in crude biological fluids and is not affected by the presence of enzymatic inhibitors and/or activators.

Adult↗
PubMed1981

Serum deoxyribonuclease I and clinical activity in systemic lupus erythematosus.

Serum deoxyribonuclease I (DNase I) activity in systemic lupus erythematosus (SLE) patients was shown to be lower than that of healthy laboratory personnel, rheumatoid arthritis, and scleroderma patients (P less than 0.001). The decrease in DNase I activity in SLE sera was not due to the effect of various autoantibodies or to heat labile DNase I inhibitor. A relationship between serum DNase I activity and active SLE was demonstrated. Patients with active lupus nephritis had the lowest levels of enzymatic activity.

Adult↗
PubMed1980

The effects of physician counseling technique on parent reactions to mental retardation diagnosis.

Many parents of mentally retarded children express dissatisfaction with how physicians initially communicate the diagnosis. We conducted a structured interview to identify and evaluate circumstances and counseling techniques which parents felt influenced their reactions to the initial diagnostic interview. Significant physician behaviors were an attitude of concern, appreciation of the handicapped child's value to the parents as a love object, planning an uninterrupted and unhurried discussion of the findings, allowing parent contact with the child before the diagnosis was told, sharing extensive information with the parents but without absolute predictions, and making specific practical recommendations. Satisfied parents were more likely to follow the physician's recommendations. The degree of dissatisfaction did not correlate with lag time before parents enrolled in an early childhood special education program. Other obstacles exist to early intervention.

Adaptation, Psychological↗
PubMed1980

The effect of high antigen density on solid-phase radioimmunoassays for antibody regardless of immunoglobulin class.

Human sera containing antibody to casein or to bovine serum albumin were used to assess the validity and utility of a solid-phase assay for quantitating antibody activity. Rabbit anti-human immunoglobulin radiolabeled with 125I and capable of reacting with all human immunoglobulin classes was used to detect antibody bound to antigen immobilized to polystyrene tubes by a new covalent technique. This method results in very high antigen concentrations in highly stable association with polystyrene tubes. Kinetic and absorption studies demonstrated that low avidity antibodies are better detected when antigen is immobilized by the covalent method than when passively adsorbed. Conditions are described for minimizing artifactual interactions and for obtaining results similar to those obtained with conventional, liquid-phase assays. Failure to reach equilibrium in solid-phase assays and other problems are proposed to explain, in part, the inability to obtain a better correlation between solid- and liquid-phase immunoassays.

Animals↗
PubMed1979

Simultaneous immunologic studies of skin and kidney in systemic lupus erythematosus clinicopathologic correlations.

Thirty-two biopsies of kidneys and of normal skin were performed simultaneously on patients with systemic lupus erythematosus (SLE) to determine whether the deposition of immune reactants in skin was correlated with the severity of renal injury or with several serologic measures of systemic disease activity. Immunofluorescent deposits at the dermal-epidermal junction (lupus band test) did not correlate with any clinical or histologic measures of glomerulonephritis or with serologic abnormalities. Immune deposits in dermal venules were found in 56% of the skin biopsies and were correlated with hypocomplementemia and higher levels of immune complexes in serum, and possibly with glomerular subendothelial electron dense deposits. Azathioprine therapy was correlated with absence of both sub-epidermal and vascular immune deposits. Immuno-fluorescent findings on serial skin biopsies on 13 patients were highly inconsistent. It is concluded that the lupus band test is clinically useful only as a diagnostic aid but not helpful in assessing renal or serologic activity of lupus, and that dermal vascular deposits of immunoglobulin or complement are more frequent than previoulsy recognized and correlate with measures of circulating immune complexes.

Adolescent↗
PubMed1979

Effects of a program for evaluating child psychiatry fellows.

The authors describe their experience with the implementation of a systematic evaluation of child psychiatry fellows and adult psychiatry residents rotating through a child psychiatry program. They found that the semiannual evaluations not only defined the competence of fellows and residents but also enhanced the program by pointing out areas of weakness. The evaluation process had many other beneficial effects on the program, the faculty, the child psychiatry fellows, and the adult psychiatry residents.

Adult↗