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A Davidson

Publications and source records attributed to A Davidson.

At least 181 records · Page 10Linked to original sources
PubMed1986

Use of anti-idiotypic antibodies to explore genetic mechanisms of production of anti-DNA antibodies.

Systemic lupus erythematosus (SLE) is characterized by the production of autoantibodies with a broad range of antigenic specificities, including specificity for double-stranded DNA. Analysis of the idiotypic profile of anti-DNA antibodies both in humans and mice has demonstrated presence of cross-reactive idiotypes, suggesting that they arise from a restricted number of germline genes. Our laboratory has previously reported the generation of 3I, a monoclonal anti-idiotypic antibody which recognizes a cross-reactive idiotype on anti-DNA antibodies in a majority of unrelated humans with SLE. We have recently studied the expression of 3I in sera of three human kindreds with familial SLE. We found 6 of 8 SLE patients and 15 of 19 unaffected family members had elevated 3I reactivity. Eleven of these family members had no anti-DNA activity despite elevated 3I reactivity, suggesting that expression of this idiotype in certain individuals is part of the normal immune response. In another set of experiments using an in vitro culture system we examined somatic mutants of the S107 mouse myeloma cell line. This line makes an antibody which bears the T15 idiotype, a common idiotype on antibodies to the bacterial antigen phosphoryl choline (PC). U4, a mutant, makes an immunoglobulin which varies by one amino acid from the parent protein, retains the T15 idiotype, but loses reactivity with PC and acquires reactivity with DNA. We have found that some anti-DNA antibodies in mice with spontaneous lupus and in mice immunologically induced to make anti-DNA antibodies bear the T15 idiotype and may represent somatic mutants arising in vivo.

Animals↗
PubMed1986

Management of pregnancy-induced hypertension with pindolol--comparative study with methyldopa.

Thirty-two consecutive women with pregnancy-induced hypertension of early onset were randomly allocated to treatment with pindolol or methyldopa. There was no difference between the groups in regard to the average time of delivery (36.33 vs. 36.6 weeks) and weight of the newborn (2850 vs. 2870 g). A significant drop in systolic (P less than 0.005) and diastolic (P less than 0.05) blood pressure was observed in the group of patients treated with pindolol as compared with the methyldopa group. In the pindolol group an improvement in renal function was observed as determined by CCT and serum creatinine. There were no side effects from the drugs in the mother or in the newborn.

Adult↗
PubMed1985

IgG binding enhances DNAase I sensitivity of N-acetoxy-N-2-acetylaminofluorene-modified phi X-174 RF DNA.

DNA restriction fragments of phi X-174 RF were modified with the carcinogen, N-acetoxy-N-2-acetylaminofluorene (N-Aco-AAF). Immune complexes of 5'-32P-labeled AAF-modified DNA and rabbit immunoglobulin (IgG) against AAF-guanosine were specifically bound by surface membranes of Cowan I strain micrococci whose protein A binds the Fc portion of IgG. DNAase I sensitivity of the bound DNA was 20-fold greater than in solution, but the normal pattern of hydrolysis was not altered, as determined in sequencing gels. Nonadducted DNA ligated to AAF-modified DNA acquired the enhanced sensitivity to DNAase I hydrolysis when the ligation hybrid was immunobound.

2-Acetylaminofluorene↗
PubMed1985

Chlorpromazine-associated haemolysis in anorexia nervosa.

Chlorpromazine therapy in a patient with anorexia nervosa was associated with haemolytic anaemia. In vitro red cell findings included an increased degree of red cell autohaemolysis and a chlorpromazine-dependent Heinz body formation both corrected with exogenous glucose. Activities of red cell enzymes involved with the glycolytic pathway or glutathione metabolism were normal.

Adolescent↗
PubMed1985

Familial systemic lupus erythematosus. Presence of a cross-reactive idiotype in healthy family members.

Sera of 27 members of 3 human kindreds with familial systemic lupus erythematosus (SLE) were examined for expression of a cross-reactive idiotype present on anti-DNA antibodies of SLE patients. By radioimmunoassay, serum samples from 6 of 8 SLE patients and 15 of 19 family members had high-titered reactivity with the antiidiotype, 3I. Isoelectric focusing and Western blot analysis of 3I-reactive bands revealed two patterns of reactivity: either a pattern of bands present at pH 5-7, or bands present at pH 5-7 with additional bands present at pH 7-8.5. Cationic bands were found to correlate with the presence of anti-DNA antibodies, indicating that immunoglobulin charge may be a factor in determining specificity for DNA. Millipore filter analysis revealed anti-DNA antibodies in sera of 4 of 8 SLE patients and 2 of 19 family members without SLE. In 2 additional SLE patients and 2 additional family members, anti-DNA antibodies were revealed when sera were analyzed under conditions that dissociate immune complexes. This study indicates that expression of an idiotype associated with anti-DNA antibodies is significantly increased in relatives of SLE patients and usually occurs in the absence of anti-DNA activity.

Antibodies, Antinuclear↗
PubMed1985

Assessment of esophageal abnormalities in progressive systemic sclerosis using radionuclide transit.

Radionuclide transit (RT) is a noninvasive test of esophageal function with a sensitivity equivalent to manometry. Using RT, 34 patients with progressive systemic sclerosis (PSS), 15 with diffuse scleroderma and 18 with the CRST variant, were studied and compared to 22 patients with other connective tissue diseases and 20 normal volunteers. Abnormalities were present in 87% of patients with diffuse scleroderma, 72% with CRST, 38% with other connective tissue diseases and in none of the controls. The most frequent abnormality in PSS was that of adynamic transit. Abnormalities correlated with disease duration in the diffuse scleroderma group but not the CRST group. There was a positive association between abnormal RT and the presence of esophagitis in the PSS patients (p = 0.003).

Adolescent↗