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Biomedical subjects

B Shohat

Publications and source records attributed to B Shohat.

At least 73 records · Page 4Linked to original sources
PubMed1984

Effect of cimetidine on T lymphocytes in a patient with giant benign gastric ulcer.

In view of the findings that Cimetidine, used in the treatment of gastric ulcers, blocks histamine-type 2 receptors, which are also present on T suppressor lymphocytes, a study was carried out in a 65-year-old male suffering from giant benign gastric ulcer and in parallel for control purposes in a healthy male of the same age. T suppressor cells obtained from peripheral blood of the patient were tested prior to institution of treatment with Cimetidine and 21, 62 and 100 days thereafter using 3 different tests - theophylline sensitivity, monoclonal antibodies OKT4 and OKT8 and as a functional test a local xenogeneic graft-versus-host reaction (GVHR). The number and percentage of T suppressor cells, which were high before treatment, showed a significant decrease after two months of treatment and this was paralleled by a decrease in suppressor activity and reversal of the functional activity of the T cells from negative to normal. Helper cells were normal before and after treatment. At the same time the patient showed a marked clinical improvement, with healing of the ulcer evidenced by endoscopy. It is suggested that Cimetidine may effect healing by influencing immune mechanisms.

Aged↗
PubMed1984

T-cell subsets in a cyclosporin-A treated recipient of cadaveric kidney allograft as defined by theophylline sensitivity and monoclonal antibodies.

Three different methods (theophylline sensitivity, monoclonal antibodies and a local xenogeneic graft-versus-host reaction) were used to study the T-cell subsets in two renal allograft recipients, one who was treated with cyclosporin-A + prednisone after having received preoperative gradual lymphoid irradiation and one who was treated by conventional methods following transplantation. In the patient treated with cyclosporin-A, who experienced no clinical rejection and has been in good condition during four months of follow-up, the percentage of theophylline-sensitive TS cells rose from 3% following irradiation to 38% one week after transplantation and treatment; T suppressor cells tested by OKT8 antibodies ranged from 60% to 100% whereas the helper cells tested by OKT4 ranged from 10% to 40%, with a ratio of OKT4/OKT8 below 0.6. In the patient receiving conventional treatment, who underwent unresponsive acute renal rejection 21 days after transplantation, the level of suppressor cells was much lower, ranging from 12% to 42%, with the OKT4/OKT8 ratio ranging from 1.47 to 2.5.

Adult↗
PubMed1983

In vitro induction of T suppressor lymphocytes in recipients of renal allografts by THF, a thymic hormone.

Lymphocyte subpopulations were determined in 13 patients, recipients of kidney allografts, 7 of them during an acute rejection episode (ARE). Monitoring of the T lymphocyte suppressor or T helper cells was performed by aid of the theophylline sensitivity test and the local xenogeneic graft-versus-host reaction (GVHR). An absence or a striking decrease of theophylline-sensitive T suppressor cells was found in all patients during ARE. Incubation of the lymphocytes of these patients with a thymic hormone, THF, raised the number of TS lymphocytes from nil or from a very low level to normal or above. The therapeutic use of THF in selected renal allograft recipients is proposed.

Acute Disease↗
PubMed1983

Induction of suppressor T cells in asthmatic children by theophylline treatment.

The absolute T-cell numbers and function, and the T-suppressor-cell subset were tested in eleven children with extrinsic asthma prior to and 1 month after theophylline treatment. Low mean T-suppressor-cell number and function was found in the asthmatic children, which returned to normal levels and function after 1 month of theophylline treatment. A normal mean T-cell number was found in this group of children prior to, and 1 month after, theophylline treatment. An obvious correlation between the clinical severity of the asthma and the number of T suppressor cells was found. It is suggested that theophylline most probably activated the T suppressor cells in the asthmatic children.

Adolescent↗
PubMed1983

Lack of suppressor T cells in renal transplant recipients and activation by aminophylline.

Immunoregulatory T-cell subsets were determined in 16 patients after renal transplantation. Suppressor and helper T lymphocytes were isolated with the aid of theophylline according to the method described by Shore et al. [1]. The system model used for assessing the function of these subsets was the local xenogeneic graft-versus-host reaction (GVHR). Lack of suppressor T cells was found in 6 out of the 16 patients, all 6 in acute steroid nonresponsive rejection crisis. Four of these patients received aminophylline per os at a dose of 1000 mg/kg per day and the T-lymphocyte subsets were retested several days afterwards. Active suppressor T cells (TS) appeared in all 4 treated patients, paralleled by disappearance of rejection crisis and a dramatic decrease of serum creatinine levels. These findings suggest that the inactivation of the immunoregulatory suppressor subset, probably by the immunosuppressive treatment, may play an important role in acute rejection and that activation of this subset of T suppressors could be of beneficial effect and prevent renal rejection.

Acute Disease↗
PubMed1983

Suppressor factor in plasma of aminophylline treated renal transplanted patients.

Eleven of 15 patients with a first acute rejection episode following cadaveric renal transplantation resumed adequate graft function and increased peripheral blood suppressor T-lymphocyte activity following treatment with 'pulse' methylprednisolone and aminophylline (1000mg orally daily for 14 days). Four of 11 patients treated with 'pulse' methylprednisolone alone resumed adequate graft function, but only two of these had elevated peripheral blood suppressor T-lymphocyte function. Nine of the 11 responding patients exhibited plasma suppressor activity to xenogenic graft versus host reaction but such activity was not observed in the plasma of any of the 11 patients who received methylprednisolone alone.

Aminophylline↗
PubMed1982

Immunological profile of patients with transitional cell carcinoma of the bladder.

The immunological profile of 58 patients with various stages of transitional cell carcinoma of the bladder was determined by using the local xenogeneic graft versus host reaction (GVHR) test, by skin testing with 3 recall antigens (candida, trichophyton, streptokinase-streptodornase) and by quantification of T-lymphocytes. Thirty-two patients with low grade low stage tumours (Group A) showed only a slight impairment of the immunological profile with a slight decrease in T-lymphocytes, 4.4% negative GVHR tests and 31.2% negative skin tests. Ten patients with highly invasive inoperable tumours (Group B) showed a severe impairment of the immunological profile with a significant decrease in T-lymphocytes, 100% negative GVHR and 80% negative skin tests. A marked improvement in the immunological profile was noted while comparing 9 patients who were examined within 6 months after cystectomy (Group CI) (severe decrease in T-lymphocytes 44.4% negative GVHR tests and 66.6% negative skin tests) with 7 patients who were examined 18 months or more after operation (Group CII) (slight decrease in T-lymphocytes 0% negative GVHR and 42.8% negative skin tests). Incubation of T-lymphocytes with a thymic hormone (THF) caused an increase in the extent of the graft versus host reaction in 10 out of 14 patients with low grade low stage bladder tumours. This may represent an improvement in the functional activity of the T-lymphocytes with a possible therapeutic use in the future.

Adult↗
PubMed1982

Suppressor, helper and immunoregulatory T cells in normal human blood as defined by theophylline sensitivity.

Two functionally distinct subpopulations of human T cells, one T suppressor and the other T-helper lymphocytes, were separated from normal donor human peripheral blood and tested for immunoregulatory properties. The separation of these two populations was performed by the aid of theophylline sensitivity as described by Shore et al. [1]. In order to assess the activity of the suppressor and helper T lymphocytes, a local xenogeneic graft-versus-host reaction (GVHR) according to the method of Shohat et al. [13] was used. These studied demonstrated that the theophylline sensitive (TS) T-suppressor cells have a suppressor effect on normal human T cells. They were further found to consist of two cell subsets, one suppressive and radiosensitive and the other radioresistant and having the ability to induce feedback help, a finding which may explain the inverse relationship found between the quantity of TS cells added and the degree of suppression obtained in the GVHR as well as the enhancement of the GVHR obtained after addition of irradiated TS cells to autologous T cells. The theophylline resistant (TR) T cells were found to have a helper action when added to autologous T cells and were radioresistant. Soluble cell-free factors from both TS and TR cells were found to mimic the function of the cells from which they were extracted.

Animals↗
PubMed1981

Suppressor mononuclear cells in giant lymph node hyperplasia and thymoma.

The existence of suppressor mononuclear cells were demonstrated in two lymphoproliferative disorders: giant lymph node hyperplasia and thymona. The three patients tested also showed cell-mediated immunodeficiency as expressed in the low number of T cells, negative graft versus host reactions and negative skin tests; the one patient tested with phytohemagglutinin (PHA) and concavalin A (Con A) showed a low response. Suppressor activity was tested with a new experimental model, the local xenogeneic graft versus host reaction. It is proposed that this model be used for testing suppressor activities in other human disorders as well.

Adolescent↗
PubMed1981

Pre-T cell lineage of hand-mirror cells in acute lymphoblastic leukemia.

Acute lymphoblastic leukemia was observed in a 64-year-old male patient with 50-80% hand-mirror cells in the peripheral blood and in the bone marrow. Immunologic surface marker tests indicated that the cells were non-T non-B lymphocytes; however, the addition of thymosin (fraction V) to the bone marrow cells induced the capability of mounting a positive local xenogeneic graft-versus-host reaction (GVHR), demonstrating the pre-T-cell lineage of the hand-mirror cells in this patient.

Animals↗
PubMed1981

Cell-mediated immunity in patients with less than pemphigus vulgaris greater than before, during and after prolonged treatment with steroids.

A study was made of the number of T lymphocytes and thier functional activity in 16 patients with pemphigus vulgaris, 5 with involvement of the mucosa, 3 with involvement of the skin and 8 with involvement of both; 2 patients had been suffering from the disease for 7 years, one for one year and the remainder for one to 6 months prior to this investigation. Patients were tested prior to institution of treatment, while receiving initially high doses of steroids and subsequently on maintenance doses. T lymphocyte number was determined by the E rosette technique and their functional activity by a local xenogeneic graft-versus-host reaction (GVHR) developed in our laboratories. Prior to therapy 50% of the patients showed impairment in T cell function, with no improvement during intensive steroid therapy; subsequently, when the disease was under control, there was a clear tendency for function to return to normal. There was no correlation between duration of the disease and immune competence but there appeared to be a partial correlation between the latter and the degree of involvement. Our study indicates that long-term steroid therapy not only benefits the clinical condition of the patient but is associated with an improvement in the immunological status.

Adult↗
PubMed1981

Human lymphocytes-macrophages interaction: a good prognostic sign in malignant lymphoma.

The lymphocyte surface markers as well as the lymphocytes-macrophage interaction were examined in 12 malignant lymphoma patients in the peripheral blood, bone marrow and/or lymph node biopsy or in the pleural effusion (1 patient). In 5 of them a lymphocytes-macrophage interaction ("immunological island") was found: these 5 patients responded well to chemotherapy and their clinical course was satisfactory. The patients in whom a low mouse rosettes percentage was found were in a poorer clinical condition as compared to those with a high mouse rosettes percentage. The lymphocyte-macrophage interactions are probably due to immunological activation of the patient by the malignant antigen and seemed to be a good prognostic sign.

Antigens, Neoplasm↗
PubMed1980

An unusual case report: tinea capitis, verrucae vulgares and other infections in a girl with T and B cell disturbances.

Hereby described is a case of a young girl suffering from widespread dermatophytosis caused by Trichophyton violaceum which proved intractable to accepted methods of therapy throughout a number of years. The girl was also found to have a history or recurrent respiratory tract infection and pyoderma in addition to verrucae vulgares, and Giardia lamblia in the gastrointestinal tract. Investigation revealed a marked immunological deficit seen in both the cellular and humoral system. It is suggested that in similar cases resistant to therapy it may be helpful to carry out a comprehensive investigation of the immunological system.

Antibody Formation↗
PubMed1980

Cell-mediated immunity in patients with mycosis fungoides in clinical remission: effect of thymic humoral factor on the immunocompetence of the lymphocytes.

In 10 patients with mycosis fungoides (MF) who were in clinical remission following local treatment with nitrogen mustard, cell-mediated immunity was investigated by means of tests for lymphocytes, forming rosettes in the peripheral blood, and the graft-vs-host reaction as well as intradermal skin tests. The effect of thymic humoral factor (THF) on T lymphocytes with impaired immunecompetence was also investigated. The results provided evidence of various kinds of damage to the immunologic system in most of the patients. Of the 10 patients, 4 had low percentages of T cells. Eight of the 10 had a graft-vs.-host reaction which was weak or negative, and in 4 of these, the administration of THF to the lymphocytes induced an improvement in immunoreactivity. These results together with other recently reported data indicate that the determination of cell-mediated immunity in patients with MF may be of prognostic importance. Those patients whose T lymphocytes respond to treatment with THF are probably the best candidates for immunotherapy.

Adult↗
PubMed1980

Identification of T & B lymphocytes on skin sections from patients with lymphoproliferative disorders of the skin.

The T & B lymphocytes in frozen sections of skin obtained from patients with various lympho-infiltrating disorders of the skin were identified using an immunofluorescent technique. Anti T-lymphocytes serum was used as a T marker and anti Ig GMA serum and HL-B alloantigens as B markers. The method confirmed to be efficient in preliminary experiments. Specimens were obtained from patients with lymphocytic infiltration of the skin (LIS), lymphadenosis benigna cutis (LBC), lymphoma cutis (LC) and mycosis fungoides (MF). In LIS and LBC the dominant cell was found to be the T lymphocyte, suggesting that a local immune reaction of the cell mediated type may play a role in their etiology.

B-Lymphocytes↗