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Biomedical subjects

D Alarcon-Segovia

Publications and source records attributed to D Alarcon-Segovia.

At least 55 records · Page 3Linked to original sources
PubMed1983

Echocardiographic evaluation of patients with rheumatoid arthritis.

Mode M echocardiograms in 34 consecutive adult RA patients revealed no significant differences with the findings obtained in 18 normal controls of similar age and sex. One patient had an 11 mm separation between the anterior chest wall and the right ventricle suggestive of a 350 ml pericardial effusion but had no corresponding findings between the posterior left ventricular wall and the pericardium. In this patient the electrocardiogram showed low voltage and the chest roentgenogram an enlarged cardiac silhouette. The differences between these series and other series reported in the literature may reflect ethnic and therapeutic differences between the respective RA populations.

Adult↗
PubMed1983

T-cell subpopulations in the peripheral blood of patients with connective tissue diseases as determined by flow cytometry using monoclonal antibodies.

We studied by flow cytometry using monoclonal antibodies the T3, T4, and T8 subpopulations of T cells in the peripheral blood of 109 patients with various connective tissue diseases who were not receiving any treatment. Comparison of the results was made with those obtained with normal controls matched for age and sex with each connective tissue disease group. When compared as disease groups, patients with systemic lupus erythematosus (n = 41) had decreased T8 cells, but patients with active disease (n = 17) had all three T-cell subpopulations lower than their controls, whereas those with inactive disease (n = 24) showed no differences. Patients with rheumatoid arthritis (n = 23) had decreased T3 and T8 cells, whereas patients with scleroderma (n = 22) only had decreased T3 cells, and patients with primary Sjögren's syndrome (n = 15) had lower proportions of all three T-cell subpopulations than their matched controls. Patients with mixed connective tissue disease (n = 8) had proportions of all three T-cell subpopulations akin to those of their matched controls, but showed a tendency to have decreased T8 cells that reached statistical significance when compared to the entire control group. Although our findings tend to support the notion that the abnormalities in immunoregulatory T-cell circuits leading to autoimmunity are different in each connective tissue disease, the great variability found in both patients and controls seems to preclude the use of these determinations in individual patients for clinical purposes.

Antibodies, Monoclonal↗
PubMed1982

Detection and partial characterization of immune complexes in patients with rheumatoid arthritis plus Sjogren's syndrome and with Sjogren's syndrome alone.

In order to characterize the immune complexes detected in patients with Sjogren's syndrome (SS) and with rheumatoid arthritis (RA), the sera of 19 patients with SS alone and 11 with SS plus RA were examined. Elevated quantities of circulating immune complexes (CIC) were detected in 67% by the C1q-binding assay (C1q-BA), 73% by the C1q-solid phase (C1q-SP) assay, 43% by the monoclonal rheumatoid factor solid phase assay (mRF-SP) and 33% by the mRF-inhibition assay (MRF-Inh). Elevated concentrations of IgM RF were detected in 83% and of IgG RF in 73% of the sera by radioimmunoassay. Strong correlations existed between RF of the IgM and IgG classes and both the C1q-BA and the C1q-SP. Three lines of evidence indicated that RF were important components of the immune complexes detected by these radioimmunoassays. These results indicated that in those patients with RA plus SS, as well as those with SS alone, both IgM and IgG RF made substantial contributions to immune complexes detected both by C1q-BA and C1q-SP.

Antigen-Antibody Complex↗
PubMed1981

Cimetidine abrogates suppressor T cell function in vitro.

Cimetidine increased the [3H] thymidine incorporation of normal human mononuclear cells in culture both when unstimulated or when under the stimulus of phytohemagglutinin or pokeweed mitogen (PWM). It also increased their supernatant immunoglobulin production under PWM stimulus. These effects were higher when the cells were preincubated with cimetidine than when it was added simultaneously. To determine if this effect of cimetidine reflects an abrogation of suppression we studied concanavalin-A-induced suppressor function of normal mononuclear cells using both [3H] thymidine incorporation and immunoglobulin synthesis as indicator systems and found that preincubation with cimetidine caused significant decrease in suppressor cell function in both systems.

Cimetidine↗
PubMed1980

Descriptions of therapeutic arthrocenthesis and of synovial fluid in a Nahuatl text from prehispanic Mexico.

Paracelsus is considered to have been the first to record the viscid quality of the synovial fluid. However, his contemporary Bernardino de Sahagún, a Franciscan friar who came to Mexico shortly after the Spanish conquest, obtained from elderly Aztec Indians who spoke only Nahuatl the descriptions of therapeutic arthrocentesis and of the viscid nature of the synovial fluid. They compared the fluid from the knee joint to the viscid fluid from the leaves of the nopal cactus (Opuntia sp.). We here record their description and confirm the accuracy of their comparison.

History of Medicine↗
PubMed1980

Long-term treatment of symptomatic osteoarthritis with benoxaprofen. Double-blind comparison with aspirin and ibuprofen.

Benoxaprofen was compared to aspirin or to ibuprofen in 2 28-wk multiclinic double-blind trials in patients with symptomatic osteoarthritis of the knees or hips. The design of the study permitted such comparison even though aspirin and ibuprofen were given in divided doses and benoxaprofen in a single dose. The comparison of benoxaprofen with aspirin included 140 patients and that with ibuprofen 143 patients. All 3 medications caused improvement in every measure of joint disease after 1 wk of therapy and improvement was either increased or maintained for the duration of treatment.

Adult↗
PubMed1979

Antibody penetration into living cells. II. Anti-ribonucleoprotein IgG penetrates into Tgamma lymphocytes causing their deletion and the abrogation of suppressor function.

We have previously shown that an anti-ribonucleoprotein (RNP) IgG can penetrate into live human mononuclear cells (MNC) having receptors for the Fc portion of IgG. Because T cells with such receptors (Tgamma cells) seem to behave as suppressor cells in immune regulation and because this suppressor function is diminished in diseases where antinuclear antibodies appear, we considered the possibility that antinuclear IgG antibody could penetrate Tgamma cells and affect them. Herein we show that fluorescein-labeled anti-RNP IgG can penetrate into Tgamma cells, enriched by either mitogenic stimulation or separation with a subpopulation of T cells with low affinity for sheep erythrocytes. Incubation of MNC with anti-RNP IgG before carrying out the separation procedures resulted in apparent loss of Tgamma cells at the end of separation. To confirm that deletion had actually occurred, we performed a cytotoxicity assay using 51Cr-labeled T cells. Anti-RNP IgG had a significantly higher cytotoxic effect that normal IgG on T cells, particularly on those with low affinity for sheep erythrocytes that include most Tgamma cells. Suppressor cell function studied in a system where it was expanded, by either 7-day culture or incubation with concanavalin A, and detected in a reverse plaque-forming cell assay with rabbit anti-human immunoglobulin-developing antibody was found to be abrogated by the addition of anti-RNP IgG to the suppressor function-expanding cultures. Controls in Ig-free medium, or medium supplemented with normal human IgG, aggregated normal human IgG, BSA-anti-BSA immune complexes, or F(ab')2 fragments of the anti-RNP IgG, did not abrogate suppressor cell function. This indicates that the abrogation of suppressor cell function by anti-RNP IgG is due to its penetration into Tgamma cells. Suppressor cell loss and/or dysfunction caused by penetration of antinuclear antibodies into Tgamma cells may lead to the self-perpetuation of autoimmune disease.

Animals↗
PubMed1979

Antibodies to histones in systemic lupus erythematosus.

Antibodies to histones were investigated in the serum of forty-five patients with spontaneously occurring systemic lupus erythematosus (SLE) who were not receiving any form of treatment. Twenty-three had active and twenty-two had inactive disease. Thos with active disease were also studied after the initiation of corticosteroid treatment to determine the effect of treatment on anti-histone antibodies. Both a complement fixation method and indirect immunofluorescence of acid-eluted histone-reconstituted tissue sections were used, with excellent correlation between these two methods. Eleven of the forty-five SLE patients, but none of forty-five normal controls had antibodies to histone. Untreated patients with active and inactive disease had a similar incidence of antibodies to histone. They disappeared, however, soon after the initiation of treatment in the patients with active disease. Patients with antibodies to histones had a higher prevalence of cutaneous vasculitis, anaemia, lupus nephropathy and Raynaud's phenomenon, but a lower prevalence of lupus brain involvement than those without such antibodies. Only the latter, however, reached statistical significance.

Adrenal Cortex Hormones↗
PubMed1978

Free serum ribonucleoprotein in mixed connective tissue disease and other connective tissue diseases.

Free ribonucleoprotein (RNP) was found by means of a hemagglutination inhibition assay in 21 sera from 11 of 25 patients with mixed connective tissue disease (MCTD) who had 299 sera studied. Free RNP tended to appear when anti-RNP antibody titers fell or when prednisone was initiated or increased. Five of 72 SLE patients (211 sera) had free RNP in at least one serum. Three of them had anti-RNP antibodies in other sera. Free serum RNP was found in one of 20 patients with scleroderma and in two of seven patients with connective tissue disease "overlap" syndromes without anti-RNP.

Antibodies, Antinuclear↗
PubMed1978

Familial aspects of mixed connective tissue disease (MCTD). I. Occurrence of systemic lupus erythematosus in another member in two families and aggregation of MCTD in another family.

Three families are reported in which one member had MCTD and another member had either MCTD or systemic lupus erythematosus (SLE). In one family both mother and daughter probably had MCTD. The daughter, however, had prominent SLE features and kidney involvement. In another family, the mother had MCTD and the daughter had SLE; while in a third family one sister had MCTD and the other had SLE with prominent arthritis but negative anti-ribonucleoprotein (RNP) antibodies.

Adult↗
PubMed1977

Cold-reactive lymphocytotoxic antibodies in mixed connective tissue disease.

Eighty-one sera from 18 patients with mixed connective tissue disease (MCTD) and high titers of antibody to ribonucleoprotein (RNP) were investigated for the presence of lymphocytotoxic antibodies. These were found in 59% sera from 14 patients but in only one of 40 normal subjects. Although lymphocytotoxic activity tended to be higher when the disease was active or there was lymphopenia, the correlation was not statistically significant. The lymphocytotoxic antibodies were found to be cold-reactive, and located in the IgM and/or IgG-containing elution fractions from DEAE cellulose columns. IgM-containing fractions tended to be more cytotoxic. Lymphocytotoxic antibodies were partially absorbed out with cerebral cortex but not with ENA-coated sheep red blood cells. Although attention has been focused on the anti-RNP antibodies found in MCTD, other autoantibodies are also present in a high proportion of patients.

Adolescent↗
PubMed1977

Hemolytic anemia and thrombocytopenic purpura: two related subsets of systemic lupus erythematosus.

Systemic lupus erythematosus patients who develop hemolytic anemia or thrombocytopenic purpura differ from other lupus patients and are similar enough to be considered two related subsets with a more benign course. Thirty-one lupus patients with either or both these hemocytopenias were found to be significantly younger, more often males, and had less frequent fever, polyarthritis, serositis, cutaneous vasculitis, nephropathy, neurologic manifestations, and persistent hypocomplementemia than 62 lupus patients without any of these hemocytopenias. They also had lower index scores of overall disease severity and required less treatment. It seems important to subdivide lupus patients in subsets for therapeutic and prognostic purposes.

Adolescent↗