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Biomedical subjects

M Schlesinger

Publications and source records attributed to M Schlesinger.

At least 235 records · Page 13Linked to original sources
PubMed1979

The effect of xenoantisera on T-lymphocyte functions in the absence of complement.

An attempt was made to determine whether xenoantisera can detect functional receptors on mouse T lymphocytes. Antisera were raised by immunizing rabbits with BALB/c thymus cells, boiled thymus homogenate, brain homogenate or bone marrow cells. Following heat inactivation these antisera were absorbed with mouse kidney and liver homogenates, and studied for their effect, in the absence of C', on the activity of murine T lymphocytes. Rabbit anti-bone marrow serum (RAB) had no effect on the mixed lymphocyte reaction (MLR) nor on cell-mediated lysis (CML). In contrast, rabbit anti-thymus serum (RAT) and anti-boiled thymus serum (RABT) inhibited strikingly, the MLR, CML, and the response to concanavalin A and phytohemagglutinin. Rabbit anti-brain serum (RABR) caused a marked increase of the proliferation of lymphocytes both in the presence or absence of various stimuli and had no effect on the CML. Absorption experiments indicated that a number of antigens are involved in the inhibitory activity of RAT. Antibodies to a T cell specific antigen interfere with the response of T lymphocytes to mitogenic stimuli, while the activity of cytotoxic T cells is inhibited by antibodies to a determinant shared by B and T lymphocytes.

Absorption↗
PubMed1979

Mechanisms involved in the weak alloimmunogenicity of Thy-1 on mouse brain.

Immunization of mice with allogeneic brain homogenates fails to elicit an appreciable response to the Thy-1 antigen. The aim of the present study was to determine the mechanism of the low immunogenicity of allogeneic brain. Immunization of C3H mice with freshly prepared mixtures of AKR/J thymus cells with either AKR/J or C3H brain homogenates elicited a primary response to the Thy-1.1 antigen as effectively as immunization with AKR/J thymus cells. When the mixtures were incubated overnight prior to injection, only AKR/J brain homogenate but not C3H brain homogenate abrogated the capacity of AKR/J thymus cells to elicit an anti-Thy-1.1 response. Suppressor T cells did not seem to be responsible for the inability of brain to elicit an anti-Thy-1 response, as mice that received cyclophosphamide 2 days prior to injection of brain did not produce Thy-1 antibodies. Antigenic competition also did not seem to be the cause for the weak immunogenicity of Thy-1 on brain, as mixtures of thymus and brain were capable of eliciting a primary response. When spleen cells from mice hyperimmunized against Thy-1 were transferred to normal syngeneic mice, subsequent immunization with brain homogenate was capable of eliciting Thy-1 antibodies. These results indicate that Thy-1 on brain may resemble a hapten, in being incapable of eliciting a primary immune response, but behaves like a complete antigen in boosting a secondary response.

Animals↗
PubMed1979

Systemic lupus erythematosus in the older age group: computer analysis.

A computer analysis was made of the data from a prospective study of the clinical course of systemic lupus erythematosus (SLE) in 234 patients followed for an average of 46 months. All fulfilled four ARA criteria for the diagnosis of SLE. Sixteen of the 234 patients were aged 51 or older. They were compared with the 218 younger SLE patients to determine the influence of age on the signs and symptoms of the disease, the organ systems involved, the laboratory data, amount and duration of corticosteroid or azathioprine therapy, and the prognosis. The older group showed more discoid lupus, photosensitivity and pulmonary fibrosis than did the younger group, but a similar incidence of malar rash, alopecia, arthritis, arthralgia, myalgia and serositis, and a lower incidence of oral ulcers, Raynaud's phenomenon, cutaneous vasculitis, neuropsychiatric manifestations, leukopenia, hypocomplementemia and profus proteinuria. The older patients needed a lower dosage of corticosteroids, and a shorter course of azathioprine therapy. These findings suggest a milder form of SLE with better response to therapy in the older group.

Adolescent↗
PubMed1979

Thymic deficiency in Down's syndrome.

Children with Down's syndrome (DS) often have small and abnormal thymuses, with lymphocyte depletion, diminution of the cortex, and loss of corticomedullary demarcation--a picture resembling thymic involution. Besides this, they have markedly enlarged Hassall's corpuscles, some surrounded by a sheath of lymphocytes. Patients with DS are known to have increased numbers of respiratory infections; they also have a higher incidence of lymphatic leukemia than do individuals who do not have DS. Studies of cell-mediated (thymic-dependent) immunity demonstrate that children with DS have both diminished numbers of T cells as well as functional deficiency of these cells.

Child↗
PubMed1978

Computer analysis of factors influencing the appearance of aseptic necrosis in patients with SLE.

A computer analysis of 234 patients with SLE followed for an average of 31 months revealed 22 patients with aseptic necrosis of bone (AN) (9%), with projected frequency approaching 30% at 10-15 years of follow-up. Most patients developed between four and seven years after diagnosis of SLE. When compared to all other patients with SLE and no AN or to three computer-selected groups matched by age of SLE diagnosis, duration of disease, or cumulative corticosteroid dose, AN did not correlate with any of the preliminary ARA criteria, total number of criteria fulfilled, renal disease, skin vasculitis, or disease activity. Although all patients received corticosteroid therapy prior to development of AN, no correlation was found with duration, peak dose, or cumulative dose of corticosteroid therapy.

Adult↗
PubMed1978

The relationship between cholera toxin receptor and the Thy-1 antigen determinants.

The aim of the present study was to determine the relationship of the Thy-1 antigenic determinants to the cell surface ganglioside GM1. Exposure of either thymus or bone marrow cells to Thy-1 alloantiserum partially inhibited the binding of [125I]cholera toxin (CT) by the cells. Xenoantibodies to Thy-1 antigens failed to affect the binding of [125I]CT to mouse thymus cells. In the reverse experiments, treatment of either thymus cells or brain homogenate with CT did not alter their capacity to absorb Thy-1 allo- and xenoantibodies. It is concluded that GM1 ganglioside does not constitute a Thy-1 antigenic determinant.

Animals↗
PubMed1977

Distinct properties of Thy-1 antibodies elicited in rats by immunization with mouse brain.

Rats are known to possess antigenic determinants related to the Thy-1.1 allele. Immunization of rats with brain homogenates from mice carrying either the Thy-1.1 or the Thy-1.2 alleles resulted in the production antisera which were cytotoxic for thymus cells of both strains of mice. Lymph node, spleen and cortisone-resistant thymus cells were refractory to the cytotoxic effect of rat anti-mouse brain sera. Peripheral lymphocytes were fully capable of absorbing the cytotoxic activity of the sera on thymus cells, although the concentration of the antigen on their cell surface was considerably less than on thymus cells. Blocking experiments with allo- and xenoantisera to Thy-1 antigens suggested that the antigen detected by rat anti-mouse brain sera is related to the Thy-1 system. The Thy-1 specificity detected by rat antisera seems to differ from previously described Thy-1 antigens in that it attains a high concentration on thymus cells but is relatively deficient in its expression on peripheral T cells.

Animals↗
PubMed1977

Specific attachment of T-lymphocytes from cancer patients to tumor cells.

The present study describes a new approach for detecting the immune reaction of peripheral blood lymphocytes of cancer patients against tumor antigens. T-lymphocytes from patients with carcinoma of the urinary bladder were found to attach specifically to monolayers of cells of urinary bladder carcinoma line (T24). The attached T-cells were identified by their capacity to form E-rosettes with sheep red blood cells. The number of rosette forming--target attached lymphocytes (RF--TAL) was 6 times higher in bladder carcinoma patients than in healthy controls or in patients bearing other types of cancer.

Antigens, Neoplasm↗