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Biomedical subjects

A Tanay

Publications and source records attributed to A Tanay.

31 records · Page 2Linked to original sources
PubMed1985

T cell regulation of the thymus-independent antibody response to trinitrophenylated-Brucella abortus (TNP-BA).

We have previously observed a reduction of the T cell-dependent primary antibody response to dinitrophenylated keyhole limpet hemocyanin, and an enhancement of the T cell-independent response to trinitrophenylated Brucella abortus (TNP-BA) in BALB/c mice after treatment with total lymphoid irradiation (TLI). To elucidate the relative contribution of T and B cells to the enhanced T cell-independent antibody responses after TLI, a syngeneic primary adoptive transfer system was utilized whereby irradiated hosts were reconstituted with unfractionated spleen cells or a combination of purified T and B cells from TLI-treated and untreated control mice. Antibody responses of purified splenic B cells from TLI-treated BALB/c mice (TLI/B) to TNP-BA were enhanced 10-fold as compared with those of unfractionated (UF) spleen cells or B cells from normal (NL) BALB/c mice (NL/UF and NL/B, respectively). Splenic T cells from normal animals (NL/T) suppressed the anti-TNP-BA response of TLI/B by more than 100-fold. NL/T neither suppressed nor enhanced the response of NL/B. On the other hand, T cells from TLI-treated mice (TLI/T) enhanced by 100-fold the anti-TNP-BA response of NL/B, but neither suppressed nor enhanced the response of TLI/B. Thus, T cells can regulate the "T cell-independent" antibody response to TNP-BA. However, experimental manipulation of the T and B cell populations is needed to demonstrate the regulatory functions.

Animals↗
PubMed1985

Segregation of peripheral blood lymphocytes in sarcoidosis according to their affinity to insolubilized histamine.

Using a method based on the differential affinity of mononuclear cells to insolubilized histamine, we were able to distinguish several differences in the composition of T cell subpopulations between healthy control subjects and sarcoidosis patients. In 5 of 10 patients with sarcoidosis, the ability of T cells to respond to three mitogens was severely depressed, while in the remaining 5 it was similar to the response of normal subjects. After the elimination of a subpopulation of peripheral blood mononuclear cells (PBMC) that adhered to the histamine column, the response to mitogens of the unbound cells of normal control subjects was significantly lower than values obtained before separation. The histamine-unbound lymphocytes of the five patients with active sarcoidosis, whose unseparated PBMC responded poorly to mitogens, reacted significantly better to the mitogens than before the separation. This pattern of responsiveness has been previously only in PBMC of patients with autoimmune diseases. It seems that some patients with sarcoidosis possess a subpopulation of T-lymphocytes with suppressor activity and a specific affinity to insolubilized histamine, the elimination of which restores the level of response to almost normal.

Adult↗
PubMed1984

Use of total lymphoid irradiation (TLI) in studies of the T cell-dependence of autoantibody production in rheumatoid arthritis.

The effect of total lymphoid irradiation (TLI) on T cell-dependent and -independent humoral immune responses was studied in patients with intractable rheumatoid arthritis (RA). The serum levels of several autoantibodies and of antibodies to diphtheria (DT) and tetanus (TT) toxoids and to pneumococcal polysaccharide (PPS; 12 antigenic types) were studied before and after TLI. In addition, the patients were given a booster injection of DT and TT and a single injection of pneumococcal vaccine after radiotherapy. Antibody levels to DT and TT decreased about twofold after TLI and did not rise significantly (p greater than 0.05) after a booster injection. However, there was no reduction in antibody levels to PPS after TLI, and a significant rise in titers was observed after a single vaccination (p less than 0.01). The serum levels of rheumatoid factor (RF), anti-nuclear antibody (ANA), and granulocyte associated IgG rose slightly after TLI. Thus, the autoantibodies and antibodies to polysaccharides appear to be relatively independent of helper T cell function, which is markedly reduced after TLI. On the other hand, antibodies to protein antigens such as DT and TT appear to be more closely dependent upon T helper function in man, as has been reported in rodents. The findings suggest that T cell-independent autoantibody responses alone do not maintain the joint disease activity in RA, because improvement in joint disease after TLI has been reported.

Antibody Formation↗
PubMed1984

Opposite effects of total lymphoid irradiation on T cell-dependent and T cell-independent antibody responses.

The effect of total lymphoid irradiation (TLI) on the primary antibody response to the dinitrophenylated heterologous protein, keyhole limpet hemocyanin (DNP-KLH), in complete Freund's adjuvant (CFA), and to the trinitrophenylated polysaccharide antigen, Brucella abortus (TNP-BA), was studied in BALB/c mice. The antibody response to both antigens was diminished in comparison with nonirradiated mice when antigens were injected within 3 days after TLI. When the mice were immunized 30 days after completion of TLI the antibody response to DNP-KLH in CFA was still diminished, but the antibody response to TNP-BA was enhanced 5- to 10-fold as compared with that of control animals. The opposite effect of TLI on the two antibody responses was also observed in a syngeneic primary adoptive transfer system.

Animals↗
PubMed1982

Dermal vasculitis due to coumadin hypersensitivity.

A 65-year-old patient developed nonpruritic purpuric skin eruptions following 10 days of coumadin treatment. Skin biopsy revealed vasculitis and immunofluorescent studies demonstrated the presence of IgM and C3 deposits in the walls of the affected blood vessels. Rechallenge with coumadin was followed by reappearance of the skin eruptions. Indirect mast cell degranulation test and migration inhibiting factor test were positive in the presence of coumadin. These findings strongly suggest that the skin lesions were induced by an immunologic reaction to warfarin.

Aged↗
PubMed1981

Chlorpropamide-induced Syndrome of Inappropriate Antidiuretic Hormone Secretion.

The Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) is a rare but serious complication of chlorpropamide therapy. In 2 elderly women who had diabetes mellitus, the SIADH developed two months after the chlorpropamide dosage had been increased to 500 mg daily. The syndrome disappeared after withdrawal of the drug. In one of these patients, re-administration of chlorpropamide resulted in recurrence of the SIADH. A review of the current literature disclosed certain common denominators, i.e., most of the patients are elderly women whose dosage of chlorpropamide was increased shortly before the development of the SIADH.

Aged↗
PubMed1979

Long-term treatment of the syndrome of inappropriate antidiuretic hormone secretion with phenytoin.

A 68-year-old patient with the syndrome of inappropriate antidiuretic hormone secretion secondary to basilary skull fracture was treated successfully with demeclocycline and phenytoin. Phenytoin, which was considered in the past only as a useful diagnostic tool, was given to the patient on a long-term basis. The drug reversed the patient's symptoms and abnormal laboratory values to normal limits without adverse reactions during a treatment period of 8 months.

Aged↗
PubMedDate not supplied

Impairment of cellular immunity in patients with malignant external otitis.

Immunological studies were performed on 4 elderly diabetic patients with Malignant External Otitis caused by Pseudomonas aeruginosa. Impairment of cellular immunity was found. Skin tests for delayed hypersensitivity to PPD, SK-SD and Mumps antigen were negative and stimulation rates of peripheral blood lymphocytes by PHA, Con-A and PWM were depressed in all 4 patients. Serum immunoglobulins and complement levels were normal except in one case in which paraprotein IgG was found. Peripheral blood lymphoid cell markers and the neutrophil nitroblue tetrazolium (NBT) test were within normal limits in the 2 patients tested. These results indicate that cellular immune deficiency predisposes to the development of Malignant External Otitis in elderly diabetic patients.

Aged↗