Biomedical subjects
Publications and source records attributed to J R Jensen.
A 41-year-old Vietnamese refugee was found to have tuberculoid leprosy. Dapsone treatment cleared her skin lesion, but did not remove the paraesthesia in the right ulnar nerve. Immunological investigations revealed a strongly positive lepromin test and a significant change in the ratio of T-y and T-mu lymphocytes in peripheral blood. The incidence of leprosy in Vietnamese refugees in Scandinavia is discussed.
The present study describes the T lymphocytosis in infectious mononucleosis (IM), using rosette techniques, lymphocyte transformation tests, Con A suppressor tests, and chromosomal analysis. Blood was drawn from twelve patients with IM during acute illness and during convalescence. We found a T lymphocytosis with a normal sheep erythrocyte receptor affinity of T cells, using three different E-rosette techniques. The percentage of T cells with Fc receptors for IgM (T mu) was reduced during acute illness, but normal in convalescence. The percentage of T cells with Fc receptors for IgC (T gamma) was normal during illness and slightly reduced afterwards. Owing to the T lymphocytosis the total number of T gamma lymphocytes was significantly increased during IM. The lymphocyte reactivity in vitro after mitogen stimulation (PHA, Con A, PWM) was in the lower end of the normal range. We found no evidence of increased suppressor-cell activity activity during IM, using a Con A suppressor cell assay. No chromosomaL defects were observed in lymphocytes from blood.
Twenty-one patients with alopecia were screened for the immune reactivity of their peripheral blood lymphocytes. Generally, patients had only eczematous reactions when rather strong solutions of dinitrochlorobenzene (DNCB) were applied. One-third of the patients had lymphocytes with in vitro reactivity towards dinitrofluorobenzene-albumin in a lymphocyte transformation test. The percentage of T lymphocyte subpopulations in blood was normal, together with a normal in vitro function after mitogen and antigen stimulation. Six of the patients were treated with 1 g cimetidine daily for 6 weeks. We could not find clinical or immunological changes during the therapy. The findings are discussed in relation to other immunological studies of patients with alopecia and the eventual effect of cimetidine on the immune system.
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The purpose of the study was to compare several methods that have been used to assess marginal leakage of root canal fillings. Sixty-three extracted, single-rooted teeth were instrumented and filled in a standardized manner. Teeth were randomly divided into groups of twenty and exposed to solutions containing methylene blue dye, calcium-45, carbon-14-labeled urea, and iodine-125-labeled albumin for 48 hours to compare the degree of leakage indicated by each technique. Methylene blue dye was found to penetrate farther up the canal than any of the isotope tracers. Carbon-14-labeled urea penetrated farther than the calcium-45- or iodine-125-labeled albumin. The mean volume of solution penetrating the teeth was exceedingly small (0.0011 ml) and probably unimportant physiologically.
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Tuberculin skin testing with purified protein derivative (PPD) was found to induce alterations of in vitro measures of cell mediated immunity. T lymphopenia with proportionate decreases of TM and TG cell numbers were observed two days after skin testing. A relative augmentation of TM cells was demonstrated after one week. Peripheral blood mononuclear cells from negative skin responders had normal in vitro reactivity to PPD stimulation suggesting a cutaneous abberation in these individuals. Macrophage dependent depressed PHA reactivity of mononuclear cells was demonstrated two days after skin testing. No change in natural killer cell cytotoxicity was observed. Cytotoxicity was positively correlated to the number of TG cells in the assay.
The distribution of T-lymphocyte subpopulations was studied in 34 patients with primary or secondary syphilis before and after treatment. An absolute and relative T lymphopenia was found in all patients. In primary syphilis the concentration of helper cells--T cells with Fc receptors for IgM (T mu)--was low whereas in secondary syphilis the suppressor cell concentration--T cells with Fc receptors for IgG (T gamma)--was reduced. Using lymphocytes from healthy subjects this could be imitated in vitro by the addition of serum from patients with secondary syphilis. In many autoimmune diseases a low concentration of T gamma may be a primary factor in the production of autoantibodies. The occurrence of similar changes in patients with secondary syphilis, however, indicates that such fluctuations in the T-cell subpopulations may take place during a strong immune response.
Consecutive serum samples were obtained from patients with syphilis before and on three occasions after treatment. The sera contained immunosuppresive factors associated with the immunoglobulin fraction, which could depress the natural killer cell activity of healthy controls. There was no evidence that allogeneic or lymphocytotoxic antibodies played a role in immuno-suppression, which could be reproduced with both soluble and insoluble antigen-IgG-antibody complexes.
A rosette technique for the detection of human T-lymphocyte subpopulations with Fc receptors for IgG (TG cells) or IgM (TM cells) has been worked out using minimal amounts of IgG and IgM antibodies. Antibody-coated ox red blood cells (EA) were used as indicator cells. Optimal conditions for rosette enumerations required intimate T-cell-EA contact and incubation of cell mixtures for 3 h at 4 degrees C. The TM-cell level increased after culture of T cells, and TM-cell rosettes were found to be more fragile. The rosette assay was found to be reproducible and thus useful in clinical immunology.
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The immune reactivity of 25 patients with mycosis fungoides was studied twice with a 6 month interval using a panel of T lymphocyte surface markers and functional tests. Patients with clinically inactive disease (stage I + II) had normal T lymphocyte biology. Patients with clinically active disease (stage II-IV) had T lymphopenia, alterations in T cell subpopulations (T gamma and T mu) and a reduced lymphocyte reactivity in vitro following mitogen (PHA, Con A, PWM) and antigen (PPD) stimulation. They also had a reduced secretion of immunoglobulin in vitro after PWM stimulation, apparently due to the alterations in their T lymphocyte subpopulations. The observed changes in the peripheral blood T lymphocyte population and the in vitro function of lymphocytes were not shared by lymphocytes from histologically affected lymph nodes. The natural killer cell activity in blood lymphocytes was found to be normal in all patients.
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Dialyzable leukocyte extract (DLE) from human blood leukocytes gave a 3- to 8-fold increase in the cAMP concentration after addition to purified lymphocytes. No significant change in cGMP was observed. When purified lymphocytes were separated into T cells and non-T cells by an E-AET rosette technique the cAMP response was most pronounced in T cells. When further separating T lymphocytes into T cells with Fc receptors for IgG and T cells with Fc receptors for IgM (T gamma and T mu lymphocytes), the increase in cAMP following stimulation was specifically conferred to T gamma lymphocytes. Our findings may support the concept that DLE activates T gamma lymphocytes, leading to an increase in suppressor cell function.
Thirty-five adult persons with moderate to severe atopic dermatitis and increased levels of IgE in serum were studied for the presence of Fc-IgG (T gamma) and Fc-IgM (T mu) receptor-carrying T lymphocytes in peripheral blood. When T lymphocytes from the patient were kept in vitro cultures a reduced expansion of the Fc-IgG receptors was found after 24 hr of incubation, but not after 48 hr of incubation. No difference was observed concerning Fc-IgM-carrying T lymphocytes. In 19 patients we studied Con A-induced suppressor activity of blood lymphocytes using autologous PHA-stimulated lymphocytes as target cells. Following stimulation with Con A, 1 microgram/ml, for 2 and 4 days, lymphocytes from atopic patients had a reduced non-specific suppressor activity in vitro. If however, the concentration of Con A was increased to 10 microgram/ml, then lymphocytes from atopic patients exhibited a normal suppressor activity.
A 6-year-old boy presenting with swelling of cervical and axillary lymph-nodes was diagnosed as having an Epstein-Barr virus infection because of EBV-nuclear-antigen-positive B-lymphocytes in blood and lymph nodes and high antibody titres to EBV antigens. The natural killer activity of blood-lymphocytes was low, and so was the percentage of T-lymphocytes with Fc receptors for IgG (T-gamma cells). Chromosomal studies revealed a defect in the long arms of one of the chromosomes in pair no. 16 (16q22). The defect only appeared after addition of interferon to the lymphocyte cultures and preferentially in T-gamma lymphocytes. The disease progressed despite attempts to restore the patient's immune reactivity by interferon, transfer factor, and blood transfusions. Necropsy showed that the severe hyperplasia of lymph nodes found during life had become a Burkitt-like lymphoma. The possible connection between an interferon-induced chromosomal defect (break at 16q22) and reduced level of natural killer activity, reduced T-gamma lymphocytes, and proliferation of EBV-positive B-lymphocytes is discussed.
Twenty-three adult patients with atopic dermatitis of different severity and extent all without present cutaneous infection were investigated for antibody-dependent cytotoxicity mediated by purified monocytes. Compared to a healthy control group the monocyte cytotoxicity was significantly decreased for patients with more widespread dermatitis. Eight patients with acute contact dermatitis and 13 patients with extrinsic asthma or allergic rhinitis showed normal cytotoxicity. Decreased monocyte cytotoxicity in atopic dermatitis was not related to the serum IgE level. In vitro cultivation of defective monocytes from atopics did not increase cytotoxicity, nor did normal monocytes preincubated with patient serum show abnormal function. In atopic dermatitis the total number of Fc receptor bearing monocytes was normal. However, the affinity of this receptor was lower than in normals. Serial studies are needed to establish whether reduced monocyte function is a basic pathophysiologic defect in atopic dematitis.
Ninety extracted human teeth were used to compare the microleakage of composite resin over, amalgam core, and regular crown preparations under a complete cast gold crown cemented with zinc phosphate cement as determined by 2% fluorescein dye solution. Specimens were compared with and without aging after cementation in a thermal bath by cycling some of them between 4 degrees C and 60 degrees C in a 2% fluorescein dye bath and others in a similar bath held at 37 degrees C. Fluorescein dye (under ultraviolet light) demonstrated microleakage of the specimens between the crown-tooth interface and the core-tooth interface. There were no significant differences in the microleakage due to aging. The specimens held at 37 degrees C in the fluorescein dye bath showed no significant differences between the core preparations and the regular crown preparations. However, when specimens were thermally cycled between 4 degrees C and 60 degrees C, there were significant differences. With thermal cycling, the regular crown preparations were better able to resist microleakage at the crown-tooth interface than either the composite resin core or the amalgam core preparations. The results of this investigation seem to indicate a need for further evaluation of core build-ups under cemented complete gold crowns.