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Biomedical subjects

E M Lemmel

Publications and source records attributed to E M Lemmel.

At least 55 records · Page 3Linked to original sources
PubMed1982

Isolation of human monocytes by rosetting with antibody coated human erythrocytes and isopycnic gradient centrifugation.

Human erythrocytes O,Rh+ (D) coated with hyperimmune human anti-serum formed rosettes primarily with monocytes in peripheral blood mononuclear cell suspensions. The rosetting cells (EAhu-FRC), separated on a Lymphoprep gradient were found in the pellet and were up to 95% pure monocytes as judged by cytochemical criteria. A two step procedure involving depletion of T lymphocytes followed by the isolation of EAhu-RFC yielded monocytes up to 98% pure. The isolated cells did not respond to mitogens in vitro, but they act as accessory cells in mitogen-induced T lymphocyte proliferation. This simple method may be useful in studying monocyte function in human disease as it does not require a large amount of blood.

Adult↗
PubMed1981

Nitroblue-tetrazolium test for the functional evaluation of phagocytic cells: a critical analysis of the methodology.

The reduction of NBT to formazan has been suggested as an indicator of the reduction potential of biological systems. An increase in the amount of reduced formazan reflects the activation of the hexose monophosphate shunt of phagocytes cultivated in vitro, as a result of cellular stimulation by chemical or biological factors, or during phagocytosis. This phenomenon has been widely used for the determination of activated phagocytes by different methods. However, the technical limitations of these methods have not been evaluated carefully. In the investigations presented here three solvents for formazan, pyridine, dioxane and dimethyl-formamide, have been tested for their suitability as extraction agents. For each solvent the optimal wavelength for photometric evaluation has been determined and dose relation curves between dissolved formazan and OD have been established. Several factors (time, temperature, pH, contamination with water or acid) affecting the dissolving properties and stability of formazan in different solvents have been investigated. With the solvents tested, dioxane proved to be the most suitable agent for extracting NBF. Thus a methodology for the quantitative evaluation of NBT has been established. This method can be used for the identification of activators as well as of inhibitors of the phagocyte system.

Chemical Phenomena↗
PubMed1981

Immunofluorescence studies on the subcomponents of the first component of complement (C1): detection of C1q and C1s in different cells of biopsy material and on human as well as on guinea pig peritoneal macrophages.

The first component of complement (C1) is a macromolecule consisting of three distinct subcomponents, C1q, C1r, and C1s. In regard to its production site and its role in phagocytic processes it was of interest to find out whether these different subcomponents could be detected in human biopsy material only as a complex in individual cells or whether C1 subcomponents could be found on different cells. To study this question, monospecific fluorescein-labelled anti-human-C1q IgG and monospecific rhodamine-labelled anti-human C1q IgG were used. Biopsy material from human rectum was stained with fluoresceinated antisera, either by use of one antiserum or by double staining. Using this technique, these observations were made: C1q as well as C1s were detectable in individual cells in the subepithelial area of the gut. Furthermore, C1q and C1s could be found together in the same cell or separately in different cells. These findings were supported by experiments with cultured peritoneal macrophages either from human or from guinea pig. The examination of the cultured cells with the two antisera revealed that individual cells were stained either by anti-C1q or by anti-C1s antibodies. The specificity of the detection of the individual subcomponents was also proven by the peroxidase technique and by using fluoresceinated anti-human C1q F(ab')2. The membrane immunofluorescent staining revealed the presence of C1q on the membrane of the macrophage.

Animals↗
PubMed1980

Inhibition of granulocyte function by prednisolone and non-steroid anti-inflammatory drugs. Quantitative evaluation with NBT test and its correlation with phagocytosis.

The effect of prednisolone and non-steroid anti-inflammatory drugs on PMNL (polymorphonuclear leucocytes) oxidative metabolism was quantified with a newly standardized NBT test, and it was investigated whether these effects correlate with phagocytosing capacity of PMNL. Prednisolone inhibits NBT reduction in dose dependency already at concentrations, which do not interfere with phagocytosis. Thus prednisolone dissociates phagocytosis and phagocytosis-associated oxidative metabolism. High doses of prednisolone also inhibit phagocytosis. These effects of prednisolone are still demonstrable when PMNL are washed after pre-incubation with the drug. The non-steroid anti-inflammatory drugs (indomethacin, phenylbutazone and pyrazinobutazone) inhibit phagocytosis and NBT reduction at equivalent doses. When PMNL are washed after incubation with the drugs, they regain normal capacity to phagocyse and to reduce NBT. It is suggested that these drugs inhibit phagocytosis directly, and consequently the phagocytosis-associated oxidative metabolism is suppressed.

Anti-Inflammatory Agents↗
PubMed1980

Inhibitory factor(s) of lymphoproliferation produced by synovial fluid mononuclear cells from rheumatoid arthritis patients: the role of monocytes in suppression.

Synovial fluid (SF) and synovial fluid mononuclear cells (SFM) were obtained from patients with rheumatoid arthritis (R.A.). The SF stimulated normal blood monocytes for nitroblue tetrazolium (NBT) reduction and inhibited normal lymphocyte response to PHA. Similar activities were found in supernatants from the cultures of SFM cells. Molecular weight of the lymphocytes inhibitory factor(s) produced by SFM was in range 50,000 to 100,000. The factor exerted its inhibitory activity via monocytes and had no direct toxic or blocking effect on lymphocytes. Monocytes played an active role in suppression presumably via production of a second-step inhibitory signal(s). It is suggested that the monocytes activated by the SFM-produced factor(s) are in turn triggered on for suppression of lymphoproliferation. These studies implicate that the state of monocyte activation is important in the regulation of lymphocyte responsiveness. This model of suppression may provide some explanation for SF lymphocyte hyporeactivity to mitogens in R.A.

Arthritis, Rheumatoid↗
PubMed1980

Activation of human monocytes for nitroblue tetrazolium reduction and the suppression of lymphocyte response to mitogens.

Human peripheral blood mononuclear cells freed from polymorphs reduce nitroblue tetrazolium (NBT). This reduction is due to monocytes, i.e. adherent, phagocytic, esterase-positive cells with Fc receptors. Monocytes allowed to phagocytose zymosan show increased NBT reduction which under optimal conditions is 12.2 +/- 2.4 x 10(-9) mol . hr-1 . 10(-6) monocytes. Monocytes which have phagocytosed zymosan depress the mitogen response of human lymphocytes to PHA. This effect of 'activated' monocytes is due to a soluble inhibitory mediator which appears in the supernatant after culture for 24 hr. Its appearance requires protein synthesis. It is suggested that NBT reduction of peripheral blood mononuclear cells can be used as a test for the state of monocyte activation in disease. The possibility that activated monocytes may depress blast transformation in vitro in disease states is discussed.

Cell Adhesion↗
PubMed1979

[Monitoring the immune status of breast cancer patients under adjuvant chemotherapy and polychemotherapy].

The effects of various combinations of chemotherapy on the immunological status of breast cancer patients were investigated. The proportion of T cells and B cells in the peripheral blood of the patients were followed and the reactivity of lymphocytes to the mitogen phytohemagglutinin (PHA) was determined. During observation periods of 6 months it was found that patients under adjuvant chemotherapy developed only a transitory depression of B cells and T cells as well as of PHA-induced lymphocyte stimulation. However, patients under polychemotherapy showed a marked depression of these immunological markers and functions during the whole observation period. The possibility of an improved monitoring of chemotherapy in cancer patients by observation of these immunological parameters is discussed.

Antineoplastic Agents↗
PubMed1979

Immunological studies in patients with alopecia areata.

Cellular and humoral immune parameters were studied in 10 patients with alopecia areata totalis and universalis. Trends to low normal immunoglobulins levels and in vitro lymphocyte transformation to concanavalin A were observed. Serum CH-50 levels and skin test responses to mumps, candida, trichophytin and dinitrochlorobenzene (DNCB) not found in vitro. 1 patient with alopecia universalis of 33 years duration developed hair at the site of DNCB skin testing. The findings point to rather subtle immune defects in patients with this disease.

Adolescent↗
PubMed1979

[Examinations carried out in order to determine the effects of a radiotherapy on the immunity situation of tumor patients (author's transl)].

In order to evaluate the immunity situation, the percentage of B- and T-lymphocytes in the peripheral blood of tumor patients was determined before, during, and after radiotherapy. Corresponding to the tumor types, the patients were submitted to adequate irradiations with different localizations, field sizes, and doses. Most of the patients had a reduced percentage of T-cells which partly was accompanied by a so-called reverse effect, i.e. a relative increase of the percentage of B-cells. It was not possible to demonstrate any connexion between the decrease of the number of B- or T-cells and the field size, localization, and dose height.

B-Lymphocytes↗
PubMed1979

[Influence of x-rays on the B- and T-cells in the spleen of mice and their reaction on mitogenetic substances (author's transl)].

Total irradiation of mice with 100 R, 350 R and 600 R leads to a significant decrease of T- and B-cells which depends directly on the irradiation dose. This decrease can already be demonstrated on the first day after the irradiation, it reaches its culminating point on the tenth day after the irradiation. After an irradiation with 100 R, the cells of the spleen or irradiated mice show no reduced capacity of being stimulated by phytohemagglutinine, Pokeweed mitogen, and concanavalin A, in case of an irradiation with 350 R this capacity is significantly reduced only until the third day after the irradiation. The animals irradiated with 600 R show a decrease on the first day, then they have a phase of recovery on the third day which is followed by a second decrease (biphasic depression). Independently of the irradiation energy, the reduced number of B- and T-cells in the irradiated mice returns to normal values until the 48th day of observation. The functional activities, however, show a disturbance the extension and duration of which are depending on the irradiation dose.

Animals↗
PubMed1979

[Electrophoresis mobility inhibition test (emt) in immunological early diagnosis of gynaecological malignomas (author's transl)].

The electrophoresis mobility inhibition test (EMT) was employed in the examination of a total of 74 woman patients with various gynaecological malignomas, 50 women with non-malignant diseases and 41 healthy female controls. In the group of patients with malignoma, 78.4% of the test results agreed with the histological diagnosis, 21.6% of the results were false negative. In the group of patients with benign diseases, 78.0% of the test results were correct, whereas 22.0% were false-positive. One false-positive test result was seen among the healthy controls. Extensive tumour growth, chronic infections and virus diseases seem to falsify the test result. Significance, perspectives and limitations of this test system within the framework of tumour diagnosis, are discussed.

Bacterial Infections↗
PubMed1979

[The influence of pregnancy specific serum factors on the mitogen induced culture of lymphocytes (author's transl)].

The addition of 10% serum of pregnant patients to a culture of lymphocytes from healthy non-pregnant control persons inhibits the stimulation of these lymphocytes by the mitogens phytohemagglutinin (PHA), pokeweed mitogen (PWM) and concanvalin A (Con A). The inhibitory effect increases with increasing duration of pregnancy. Sera from pregnant patients which already inhibit during the first trimester of pregnancy show an increase of this effect with increasing length of gestation. The influence of several hormones and proteins was investigated in order to detect a factor in the pregnant serum responsible for the inhibition of the lymphocyte culture. Compounds which are known to increase during gestation were added as pure compounds in various concentrations to the lymphocyte culture. An inhibitory effect on the lymphocyte culture in vitro was shown dependent on the amount, by human placental lactogen, alpha-fetoprotein, human chorionic gonadotropin, cortisol, progesterone and SPI glycoprotein and alpha-2-macroglobulin. The estrogens estriol and estradiol in physiologic dosages did not show an inhibitory effect and showed a stimulatory effect in higher dosages.

Chorionic Gonadotropin↗
PubMed1979

On the feedback regulation of humoral immune response. I. Evidence for 'B suppressor cells'.

Evidence has been presented that complete and antigen-specific immune inhibition can be obtained by 'B suppressor cells'. Transfer of spleen cells from twice-immunized (SRBC) donors to untreated syngeneic recipients resulted in antigen-specific inhibition of the hosts' immune response. The cell responsible for this phenomenon could be shown to be the 7S-producing B cell; participation of T cells and macrophages could be excluded. After a second immunization of the donors, these B cells remained inhibitory for more than 20 weeks in the donors as well as in the recipients after transfer. Passively administered specific IgG antibody caused a similar inhibition of the hosts' immune response, which, however, lasted for less than 9 weeks only. The extent of inhibition caused by transfer of hyperimmune cells was parallel to the number of transferred 7S producing cells. Since it could be demonstrated that memory cells were present at times when the transferred cell material had lost its inhibitory potency, we concluded that inhibition is not caused by the mere presence of these cells. Since the transferred cells regained their inhibitory capacity after non-specific activation with LPS, we concluded that a product of such activated cells--most likely the specific 7S antibody--was responsible for the observed inhibition. Thus, it is demonstrated that B cells may serve as 'suppressor cells' in appropriate transfer experiments. It is, however, concluded that this effect is basically mediated by produced IgG and may in its mechanism be identical to the phenomenon of antibody-mediated regulation of humoral immune response.

Animals↗